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language: parse ISO EXCEPT/RETRY (M1 parser/AST)

Add EXCEPT/RETRY keywords, NkExcept/NkRetry, handler placement checking (237), and handler AST nodes for procedure, program, implementation, local-module and class bodies. EXCEPT deliberately reports 230 until M2 adds the runtime and handler codegen, so no handler is silently ignored. Regressions: t_except_parse (expect_fail 230) and t_retry_bad (237). Gates: suite 265/265, fixpoint OK 4,091,107 bytes, corpus 511/612.
Eric Streit 1 день назад
Родитель
Сommit
98da444d6e

+ 2 - 2
README.md

@@ -47,8 +47,8 @@ docs/              STATUS.md, plan.md, plan-*.md, analysis_*.md, summary_*.md
 
 ## Status (2026-10-23)
 
-- Suite **263/263**; self-hosting **fixpoint OK** (byte-identical
-  stage2/stage3, 4,075,853 bytes); corpus **511/612 compile-OK,
+- Suite **265/265**; self-hosting **fixpoint OK** (byte-identical
+  stage2/stage3, 4,091,107 bytes); corpus **511/612 compile-OK,
   0 crashes** (`tools/v3-corpus`; the corpus is gm2's testsuite, so it
   mixes conforming Modula-2 with gm2 leniencies — see `docs/gaps/`).
 - Active branch **`master`**.

+ 2 - 0
compiler/run_tests.sh

@@ -74,6 +74,8 @@ expect_run t_proctype2.mod 42
 expect_run t_byte.mod 42
 expect_run t_word16.mod 42
 expect_run t_packedset.mod 42
+expect_fail t_except_parse.mod "not supported yet"
+expect_fail t_retry_bad.mod "RETRY outside EXCEPT"
 expect_run t_smallgaps.mod 42
 expect_run t_ctor1.mod 0
 expect_run t_ctor2.mod 0

+ 2 - 0
compiler/src/AST.def

@@ -77,6 +77,8 @@ CONST
   NkHalt        = 53;
   NkGoto        = 54;  (* [0]=label ident *)
   NkLabel       = 55;  (* [0]=label ident *)
+  NkExcept      = 56;  (* [0]=body statements, [1]=handler statements *)
+  NkRetry       = 57;
 
   (* expressions *)
   NkBinExpr     = 70;  (* [0]=left, [1]=right; `op` holds the operator *)

+ 8 - 0
compiler/src/Lower.mod

@@ -2342,6 +2342,14 @@ PROCEDURE LowerStmt (seq: AST.Node);
       WHILE i < AST.NChild(seq) DO
         LowerStmt(AST.Child(seq, i)); INC(i)
       END
+    ELSIF k = AST.NkExcept THEN
+      (* M1: the parser deliberately reports 230 before this is reached
+         in a successful compilation.  Keep body-only lowering so error
+         recovery cannot crash; M2 replaces it with handler codegen. *)
+      LowerStmt(AST.Child(seq, 0))
+    ELSIF k = AST.NkRetry THEN
+      (* M1: RETRY is parsed only.  It is unreachable until M2 lowers
+         handlers; keep the case explicit rather than falling through. *)
     ELSIF k = AST.NkAssign THEN
       LowerDesign(AST.Child(seq, 0), dt, cls, qd, qn, sfx);
       LowerExpr(AST.Child(seq, 1), et, qe);

+ 118 - 12
compiler/src/M2.atg

@@ -11,7 +11,7 @@ COMPILER M2
    Semantic errors reuse the V1/V2/Test2 family: 200 duplicate,
    201 undeclared, 202 module name mismatch, 210 bad assignment,
    211 bad arithmetic, 221 not a type, 230 not supported yet,
-   231 opaque type outside definition.
+   231 opaque type outside definition, 237 RETRY outside EXCEPT.
    Scalar-phase TYPEs (named, integer subrange, enum) check fully;
    composite forms wait for step 3.    Procedure headings (formals,
    result, FORWARD) enter scopes now; bodies parse + check with one
@@ -94,6 +94,10 @@ VAR
   curProcNode: AST.Node;
   (* The procedure whose body is being parsed, for __FUNCTION__. *)
   curFun: SymTab.Name;
+  (* TRUE while parsing the statement sequence of an EXCEPT handler.
+     RETRY is only valid there.  Block saves/restores it so a nested
+     procedure body cannot inherit an outer handler. *)
+  inHandler: BOOLEAN;
 
   (* The last actual argument parsed by ActParam: folded value and type.
      A conversion T(x) has exactly one actual, so these let Fact
@@ -200,6 +204,18 @@ PROCEDURE CopyNm (src: ARRAY OF CHAR; VAR dst: SymTab.Name);
     IF i <= HIGH(dst) THEN dst[i] := CHR(0) END
   END CopyNm;
 
+PROCEDURE WrapExcept (body, handler: AST.Node): AST.Node;
+(* M1: a body with an EXCEPT part is represented as one node so Lower
+   can add handler codegen in one place later.  The handler is retained
+   in the AST even while M1 lowers only the body. *)
+  VAR n: AST.Node;
+  BEGIN
+    n := AST.MakeNode(AST.NkExcept);
+    AST.SetChild(n, 0, body);
+    AST.SetChild(n, 1, handler);
+    RETURN n
+  END WrapExcept;
+
 PROCEDURE InInst () : BOOLEAN;
   BEGIN RETURN instActive END InInst;
 
@@ -898,8 +914,13 @@ PRODUCTIONS
                                              rSym, rErr: CARDINAL;
                                              fname: SymTab.Name;
                                              unres: BOOLEAN;
-                                             astNode: AST.Node; .)
-    =                                   (. refN := 0; refSeen := FALSE; .)
+                                             astNode: AST.Node;
+                                             astBody, astHandler: AST.Node;
+                                             hasExcept: BOOLEAN; .)
+    =                                   (. refN := 0; refSeen := FALSE;
+                                           inHandler := FALSE;
+                                           astHandler := AST.NoNode;
+                                           hasExcept := FALSE; .)
       "IMPLEMENTATION" "MODULE"
       [ "FOR" string ]                  (* ISO foreign module: FOR "C" *)
       GetIdent<m1> (. IF instActive THEN InstNameGet(m1) END;
@@ -934,9 +955,17 @@ PRODUCTIONS
 
                                            nLab := 0; nGot := 0; .)
         [ StatSeq ] ]
+                                        (. astBody := astStmt; .)
+      [ "EXCEPT"                        (. (* M1: grammar/AST only; M2 removes
+                                              this 230 and adds codegen. *)
+                                           SemError(230);
+                                           hasExcept := TRUE;
+                                           inHandler := TRUE; .)
+        [ StatSeq ]                     (. astHandler := astStmt;
+                                           inHandler := FALSE .) ]
                                         (. IF twoPhaseParse THEN
                                              rSym := sym; rErr := errDist;
-                                             rDecl := astDecl; rStmt := astStmt;
+                                             rDecl := astDecl; rStmt := astBody;
                                              M2S.PushPos;
                                              repassing := TRUE;
                                              rp := 0;
@@ -986,6 +1015,10 @@ PRODUCTIONS
                                            END;
                                            SymTab.FwdClear;
 
+                                           IF hasExcept THEN
+                                             astStmt := WrapExcept(astBody,
+                                                           astHandler)
+                                           END;
                                            astNode := AST.MakeNode(AST.NkUnit);
                                            AST.SetChild(astNode, 0,
                                              AST.MakeLeaf(AST.NkIdent, m1));
@@ -1021,8 +1054,13 @@ PRODUCTIONS
                                              rSym, rErr: CARDINAL;
                                              fname: SymTab.Name;
                                              unres: BOOLEAN;
-                                             astNode: AST.Node; .)
-    = "MODULE"
+                                             astNode: AST.Node;
+                                             astBody, astHandler: AST.Node;
+                                             hasExcept: BOOLEAN; .)
+    =                                   (. inHandler := FALSE;
+                                           astHandler := AST.NoNode;
+                                           hasExcept := FALSE; .)
+      "MODULE"
       GetIdent<m1> (. IF NOT SymTab.BeginProg(m1) THEN
                                              SemError(200) END;
                                            astStmt := AST.NoNode;
@@ -1048,9 +1086,17 @@ PRODUCTIONS
 
                                            nLab := 0; nGot := 0; .)
         [ StatSeq ] ]
+                                        (. astBody := astStmt; .)
+      [ "EXCEPT"                        (. (* M1: grammar/AST only; M2 removes
+                                              this 230 and adds codegen. *)
+                                           SemError(230);
+                                           hasExcept := TRUE;
+                                           inHandler := TRUE; .)
+        [ StatSeq ]                     (. astHandler := astStmt;
+                                           inHandler := FALSE .) ]
                                         (. IF twoPhaseParse THEN
                                              rSym := sym; rErr := errDist;
-                                             rDecl := astDecl; rStmt := astStmt;
+                                             rDecl := astDecl; rStmt := astBody;
                                              M2S.PushPos;
                                              repassing := TRUE;
                                              rp := 0;
@@ -1102,6 +1148,10 @@ PRODUCTIONS
 
                                            IF NOT SymTab.Equal(m1, m2) THEN
                                              SemError(202) END;
+                                           IF hasExcept THEN
+                                             astStmt := WrapExcept(astBody,
+                                                           astHandler)
+                                           END;
                                            astNode := AST.MakeNode(AST.NkUnit);
                                            AST.SetChild(astNode, 0,
                                              AST.MakeLeaf(AST.NkIdent, m1));
@@ -1128,8 +1178,13 @@ PRODUCTIONS
                                              expNames: ARRAY [0 .. 63] OF SymTab.Name;
                                              expCount, k: CARDINAL;
                                              astNode, nImp, nImpTail:
-                                               AST.Node; .)
-    = "MODULE"
+                                               AST.Node;
+                                             astBody, astHandler: AST.Node;
+                                             hasExcept: BOOLEAN; .)
+    =                                   (. inHandler := FALSE;
+                                           astHandler := AST.NoNode;
+                                           hasExcept := FALSE; .)
+      "MODULE"
       GetIdent<m1>                      (. IF NOT SymTab.Enter(m1,
                                              SymTab.KindModule) THEN
                                              SemError(200) END;
@@ -1155,8 +1210,20 @@ PRODUCTIONS
       [ "BEGIN"                         (. astStmt := AST.NoNode;
                                            .)
         [ StatSeq ] ]
+                                        (. astBody := astStmt; .)
+      [ "EXCEPT"                        (. (* M1: grammar/AST only; M2 removes
+                                              this 230 and adds codegen. *)
+                                           SemError(230);
+                                           hasExcept := TRUE;
+                                           inHandler := TRUE; .)
+        [ StatSeq ]                     (. astHandler := astStmt;
+                                           inHandler := FALSE .) ]
       "END"
-      GetIdent<m2>                      (. AST.SetChild(astNode, 1, astDecl);
+      GetIdent<m2>                      (. IF hasExcept THEN
+                                             astStmt := WrapExcept(astBody,
+                                                           astHandler)
+                                           END;
+                                           AST.SetChild(astNode, 1, astDecl);
                                            AST.SetChild(astNode, 2, astStmt);
                                            AST.SetChild(astNode, 3, nImp);
                                            astDecl := astNode;
@@ -1824,7 +1891,9 @@ PRODUCTIONS
                                            AstAppend(AST.NkFieldDecl,
                                              astClsM, astClsMTail, astMethod); .) .
   ClassImplRest                         (. VAR cn, m2: SymTab.Name;
-                                             ct: SymTab.TypeIndex; .)
+                                             ct: SymTab.TypeIndex;
+                                             astBody, astHandler: AST.Node;
+                                             hasExcept: BOOLEAN; .)
     = GetIdent<cn>                      (. IF NOT SymTab.Lookup(cn) THEN
                                              SemError(201);
                                              ct := SymTab.InvalidType
@@ -1842,6 +1911,9 @@ PRODUCTIONS
                                            astClsM := AST.NoNode;
                                            astClsMTail := AST.NoNode;
                                            astStmt := AST.NoNode;
+                                           inHandler := FALSE;
+                                           astHandler := AST.NoNode;
+                                           hasExcept := FALSE;
                                            IF ct #
                                               SymTab.InvalidType THEN
                                              IF NOT SymTab.PushClassMembers(
@@ -1854,11 +1926,23 @@ PRODUCTIONS
       [ "BEGIN"                         (. astStmt := AST.MakeNode(AST.NkBlock);
                                            .)
         [ StatSeq ] ]
+                                        (. astBody := astStmt; .)
+      [ "EXCEPT"                        (. (* M1: grammar/AST only; M2 removes
+                                              this 230 and adds codegen. *)
+                                           SemError(230);
+                                           hasExcept := TRUE;
+                                           inHandler := TRUE; .)
+        [ StatSeq ]                     (. astHandler := astStmt;
+                                           inHandler := FALSE .) ]
       "END"
       GetIdent<m2>                      (. IF NOT SymTab.Equal(cn, m2) THEN
                                              SemError(202) END;
                                            SymTab.PopImplClass;
                                            SymTab.PopScope;
+                                           IF hasExcept THEN
+                                             astStmt := WrapExcept(astBody,
+                                                           astHandler)
+                                           END;
                                            AST.SetChild(astCls, 1, AST.NoNode);
                                            AST.SetChild(astCls, 2, astStmt);
                                            AST.SetChild(astCls, 3, astClsM);
@@ -2176,8 +2260,14 @@ PRODUCTIONS
                                              QbeGen.EndFunc(
                                                SymTab.ProcRes(pn))
                                            END; .) ) .
-  Block<pn: SymTab.Name>                (. VAR m2: SymTab.Name; dfr: BOOLEAN; .)
+  Block<pn: SymTab.Name>                (. VAR m2: SymTab.Name; dfr: BOOLEAN;
+                                             astBody, astHandler: AST.Node;
+                                             hasExcept, saveHandler: BOOLEAN; .)
     =                                   (. dfr := FALSE;
+                                           saveHandler := inHandler;
+                                           inHandler := FALSE;
+                                           astHandler := AST.NoNode;
+                                           hasExcept := FALSE;
                                            IF allowDefer AND twoPhaseParse
                                               AND NOT repassing THEN
                                              dfr := DeferSkip(pn)
@@ -2198,9 +2288,22 @@ PRODUCTIONS
                                              END
                                            END; .)
         [ StatSeq ] ]
+                                        (. astBody := astStmt; .)
+      [ "EXCEPT"                        (. (* M1: grammar/AST only; M2 removes
+                                              this 230 and adds codegen. *)
+                                           SemError(230);
+                                           hasExcept := TRUE;
+                                           inHandler := TRUE; .)
+        [ StatSeq ]                     (. astHandler := astStmt;
+                                           inHandler := FALSE .) ]
       "END"
       GetIdent<m2>                      (. IF NOT SymTab.Equal(pn, m2) THEN
                                              SemError(202) END;
+                                           inHandler := saveHandler;
+                                           IF hasExcept THEN
+                                             astStmt := WrapExcept(astBody,
+                                                           astHandler)
+                                           END;
                                            CheckGotos; .) .
   (* Two-phase, phase 2 (milestone 2c): re-parse every deferred module-
      level body once the unit's declarations are complete.  Inlined at
@@ -2235,6 +2338,9 @@ PRODUCTIONS
     | "EXIT"                            (. IF NOT QbeGen.TopLoop(lx) THEN
                                              SemError(230) END;
                                            astStmt := AST.MakeNode(AST.NkExit); .)
+    | "RETRY"                           (. IF NOT inHandler THEN
+                                             SemError(237) END;
+                                           astStmt := AST.MakeNode(AST.NkRetry); .)
     | "GOTO" GetIdent<lxnm>             (. NoteGoto(lxnm);
                                            astStmt := AST.MakeNode(AST.NkGoto);
                                            AST.SetChild(astStmt, 0,

+ 4482 - 4376
compiler/src/M2.lst

@@ -35,7 +35,7 @@ Listing:
    11     Semantic errors reuse the V1/V2/Test2 family: 200 duplicate,
    12     201 undeclared, 202 module name mismatch, 210 bad assignment,
    13     211 bad arithmetic, 221 not a type, 230 not supported yet,
-   14     231 opaque type outside definition.
+   14     231 opaque type outside definition, 237 RETRY outside EXCEPT.
    15     Scalar-phase TYPEs (named, integer subrange, enum) check fully;
    16     composite forms wait for step 3.    Procedure headings (formals,
    17     result, FORWARD) enter scopes now; bodies parse + check with one
@@ -118,4405 +118,4511 @@ Listing:
    94    curProcNode: AST.Node;
    95    (* The procedure whose body is being parsed, for __FUNCTION__. *)
    96    curFun: SymTab.Name;
-   97  
-   98    (* The last actual argument parsed by ActParam: folded value and type.
-   99       A conversion T(x) has exactly one actual, so these let Fact
-  100       constant-fold it (needed for `CONST c = T(x)`). *)
-  101    convQ: QbeGen.QVal;
-  102    convT: SymTab.TypeIndex;
-  103  
-  104    (* Result slot for the expression-AST builder (slice 2).  Every
-  105       Expr/SimExpr/Term/Fact leaves its node here; the combination
-  106       productions save it into locals before parsing the next operand.
-  107       `astIsLit` in Fact is per-invocation, so a nested Fact cannot make
-  108       an outer non-literal Fact look literal. *)
-  109    astCur: AST.Node;
-  110  
-  111    (* Actual-argument nodes collected by ActParam for the call being
-  112       parsed by ArgList (slice 4).  Fact resets the count before the
-  113       optional ArgList and then folds the nodes into an NkCall. *)
-  114    astNArgs: CARDINAL;
-  115    astArgs: ARRAY [0 .. 31] OF AST.Node;
-  116  
-  117    (* Statement-AST result slot (slice 5): the most recently parsed
-  118       statement.  StatSeq folds these into an NkBlock. *)
-  119    astStmt: AST.Node;
+   97    (* TRUE while parsing the statement sequence of an EXCEPT handler.
+   98       RETRY is only valid there.  Block saves/restores it so a nested
+   99       procedure body cannot inherit an outer handler. *)
+  100    inHandler: BOOLEAN;
+  101  
+  102    (* The last actual argument parsed by ActParam: folded value and type.
+  103       A conversion T(x) has exactly one actual, so these let Fact
+  104       constant-fold it (needed for `CONST c = T(x)`). *)
+  105    convQ: QbeGen.QVal;
+  106    convT: SymTab.TypeIndex;
+  107  
+  108    (* Result slot for the expression-AST builder (slice 2).  Every
+  109       Expr/SimExpr/Term/Fact leaves its node here; the combination
+  110       productions save it into locals before parsing the next operand.
+  111       `astIsLit` in Fact is per-invocation, so a nested Fact cannot make
+  112       an outer non-literal Fact look literal. *)
+  113    astCur: AST.Node;
+  114  
+  115    (* Actual-argument nodes collected by ActParam for the call being
+  116       parsed by ArgList (slice 4).  Fact resets the count before the
+  117       optional ArgList and then folds the nodes into an NkCall. *)
+  118    astNArgs: CARDINAL;
+  119    astArgs: ARRAY [0 .. 31] OF AST.Node;
   120  
-  121    (* Declaration-AST result slot (slice 6): the most recently built
-  122       declaration; DeclSeq folds these into an NkDeclSeq. *)
-  123    astDecl: AST.Node;
+  121    (* Statement-AST result slot (slice 5): the most recently parsed
+  122       statement.  StatSeq folds these into an NkBlock. *)
+  123    astStmt: AST.Node;
   124  
-  125    (* The local declarations of the most recent Block (a procedure body);
-  126       ProcDecl stores them as the proc node's child 2. *)
-  127    astBlkDecls: AST.Node;
+  125    (* Declaration-AST result slot (slice 6): the most recently built
+  126       declaration; DeclSeq folds these into an NkDeclSeq. *)
+  127    astDecl: AST.Node;
   128  
-  129    (* Unit-AST root (slice 7): NkUnit(name, decls, body). *)
-  130    astUnit: AST.Node;
-  131  
-  132    (* Import accumulator (slice 11): `{ Import }` appends NkImport
-  133       nodes here; each unit stores them as NkUnit child[3]. *)
-  134    astImp, astImpTail: AST.Node;
+  129    (* The local declarations of the most recent Block (a procedure body);
+  130       ProcDecl stores them as the proc node's child 2. *)
+  131    astBlkDecls: AST.Node;
+  132  
+  133    (* Unit-AST root (slice 7): NkUnit(name, decls, body). *)
+  134    astUnit: AST.Node;
   135  
-  136    (* Class-AST accumulators (slice 13): the class node currently being
-  137       parsed and its parent/field/method lists.  Classes are not nested
-  138       inside one another, so module-level state is safe. *)
-  139    astCls, astClsP, astClsPTail, astClsF, astClsFTail,
-  140    astClsM, astClsMTail, astMethod: AST.Node;
-  141  
-  142    (* Class of the method named by the last `obj.Method` designator
-  143       (InvalidType when the callee is an ordinary procedure). Set by
-  144       Design, consumed by the following ArgList. *)
-  145    methCls: SymTab.TypeIndex;
-  146    (* Class of the type of the innermost `TypeName{...}` brace
-  147       constructor (ClSet or ClArray); dispatches BraceElem. *)
-  148    braceCls: INTEGER;
-  149    (* Module-level VAR declarations whose type was still an unresolved
-  150       forward alias at declaration time; emitted once the TYPE block
-  151       completes (module scope only). *)
-  152    nPendVar: CARDINAL;
-  153    pendVarName: ARRAY [0 .. 255] OF SymTab.Name;
-  154    pendVarT: ARRAY [0 .. 255] OF SymTab.TypeIndex;
-  155    (* Forward module-level variables referenced from a procedure body. *)
-  156    (* GOTO/labels: the label and goto names of the procedure being parsed,
-  157       reset per procedure and checked at its END. *)
-  158    nLab, nGot: CARDINAL;
-  159    labNm, gotNm: ARRAY [0 .. 255] OF SymTab.Name;
-  160  
-  161    (* Generics (Increment 1): the last refining module seen — instance
-  162       name, generic name, and the actual type parameters. *)
-  163    refInst, refGen: SymTab.Name;
-  164    refN: CARDINAL;
-  165    refActual: ARRAY [0 .. 15] OF SymTab.TypeIndex;
-  166    refKind: ARRAY [0 .. 15] OF INTEGER;   (* 0 = type, 1 = value, 2 = proc *)
-  167    refVal:  ARRAY [0 .. 15] OF SymTab.Name;
-  168    refMod:  ARRAY [0 .. 15] OF SymTab.Name;
-  169    isGen: BOOLEAN;
-  170  
-  171    (* Generics (Increment 2): instantiation re-parse context.  When the
-  172       driver re-parses a generic's source to instantiate it as `instName`,
-  173       instActive is TRUE, the module is renamed, and each type formal is
-  174       bound to the corresponding instActual entry. *)
-  175    instActive: BOOLEAN;
-  176    instName: SymTab.Name;
-  177    instActual: ARRAY [0 .. 15] OF SymTab.TypeIndex;
-  178    instKind: ARRAY [0 .. 15] OF INTEGER;
-  179    instVal:  ARRAY [0 .. 15] OF SymTab.Name;
-  180    instMod:  ARRAY [0 .. 15] OF SymTab.Name;
-  181    instN: CARDINAL;
-  182    instFk: CARDINAL;   (* formal cursor while binding during re-parse *)
-  183  
-  184    (* Identity of the last-parsed unit and refinement, for the driver's
-  185       generic registry and its re-parse decision. *)
-  186    unitName: SymTab.Name;
-  187    unitWasGen: BOOLEAN;
-  188    unitWasDef: BOOLEAN;
-  189    refSeen: BOOLEAN;
-  190    refIsDef: BOOLEAN;
-  191  
-  192  
-  193  PROCEDURE CopyNm (src: ARRAY OF CHAR; VAR dst: SymTab.Name);
-  194    VAR i: CARDINAL;
-  195    BEGIN
-  196      i := 0;
-  197      WHILE (i <= HIGH(dst)) AND (i <= HIGH(src)) AND (src[i] # CHR(0)) DO
-  198        dst[i] := src[i]; INC(i)
-  199      END;
-  200      IF i <= HIGH(dst) THEN dst[i] := CHR(0) END
-  201    END CopyNm;
-  202  
-  203  PROCEDURE InInst () : BOOLEAN;
-  204    BEGIN RETURN instActive END InInst;
-  205  
-  206  PROCEDURE InstNameGet (VAR nm: SymTab.Name);
-  207    BEGIN CopyNm(instName, nm) END InstNameGet;
-  208  
-  209  PROCEDURE InstActualGet (i: CARDINAL) : SymTab.TypeIndex;
-  210    BEGIN
-  211      IF i >= instN THEN RETURN SymTab.InvalidType END;
-  212      RETURN instActual[i]
-  213    END InstActualGet;
-  214  
-  215  PROCEDURE InstBegin (name: ARRAY OF CHAR);
-  216    BEGIN instActive := TRUE; CopyNm(name, instName); instN := 0;
-  217      instFk := 0 END InstBegin;
+  136    (* Import accumulator (slice 11): `{ Import }` appends NkImport
+  137       nodes here; each unit stores them as NkUnit child[3]. *)
+  138    astImp, astImpTail: AST.Node;
+  139  
+  140    (* Class-AST accumulators (slice 13): the class node currently being
+  141       parsed and its parent/field/method lists.  Classes are not nested
+  142       inside one another, so module-level state is safe. *)
+  143    astCls, astClsP, astClsPTail, astClsF, astClsFTail,
+  144    astClsM, astClsMTail, astMethod: AST.Node;
+  145  
+  146    (* Class of the method named by the last `obj.Method` designator
+  147       (InvalidType when the callee is an ordinary procedure). Set by
+  148       Design, consumed by the following ArgList. *)
+  149    methCls: SymTab.TypeIndex;
+  150    (* Class of the type of the innermost `TypeName{...}` brace
+  151       constructor (ClSet or ClArray); dispatches BraceElem. *)
+  152    braceCls: INTEGER;
+  153    (* Module-level VAR declarations whose type was still an unresolved
+  154       forward alias at declaration time; emitted once the TYPE block
+  155       completes (module scope only). *)
+  156    nPendVar: CARDINAL;
+  157    pendVarName: ARRAY [0 .. 255] OF SymTab.Name;
+  158    pendVarT: ARRAY [0 .. 255] OF SymTab.TypeIndex;
+  159    (* Forward module-level variables referenced from a procedure body. *)
+  160    (* GOTO/labels: the label and goto names of the procedure being parsed,
+  161       reset per procedure and checked at its END. *)
+  162    nLab, nGot: CARDINAL;
+  163    labNm, gotNm: ARRAY [0 .. 255] OF SymTab.Name;
+  164  
+  165    (* Generics (Increment 1): the last refining module seen — instance
+  166       name, generic name, and the actual type parameters. *)
+  167    refInst, refGen: SymTab.Name;
+  168    refN: CARDINAL;
+  169    refActual: ARRAY [0 .. 15] OF SymTab.TypeIndex;
+  170    refKind: ARRAY [0 .. 15] OF INTEGER;   (* 0 = type, 1 = value, 2 = proc *)
+  171    refVal:  ARRAY [0 .. 15] OF SymTab.Name;
+  172    refMod:  ARRAY [0 .. 15] OF SymTab.Name;
+  173    isGen: BOOLEAN;
+  174  
+  175    (* Generics (Increment 2): instantiation re-parse context.  When the
+  176       driver re-parses a generic's source to instantiate it as `instName`,
+  177       instActive is TRUE, the module is renamed, and each type formal is
+  178       bound to the corresponding instActual entry. *)
+  179    instActive: BOOLEAN;
+  180    instName: SymTab.Name;
+  181    instActual: ARRAY [0 .. 15] OF SymTab.TypeIndex;
+  182    instKind: ARRAY [0 .. 15] OF INTEGER;
+  183    instVal:  ARRAY [0 .. 15] OF SymTab.Name;
+  184    instMod:  ARRAY [0 .. 15] OF SymTab.Name;
+  185    instN: CARDINAL;
+  186    instFk: CARDINAL;   (* formal cursor while binding during re-parse *)
+  187  
+  188    (* Identity of the last-parsed unit and refinement, for the driver's
+  189       generic registry and its re-parse decision. *)
+  190    unitName: SymTab.Name;
+  191    unitWasGen: BOOLEAN;
+  192    unitWasDef: BOOLEAN;
+  193    refSeen: BOOLEAN;
+  194    refIsDef: BOOLEAN;
+  195  
+  196  
+  197  PROCEDURE CopyNm (src: ARRAY OF CHAR; VAR dst: SymTab.Name);
+  198    VAR i: CARDINAL;
+  199    BEGIN
+  200      i := 0;
+  201      WHILE (i <= HIGH(dst)) AND (i <= HIGH(src)) AND (src[i] # CHR(0)) DO
+  202        dst[i] := src[i]; INC(i)
+  203      END;
+  204      IF i <= HIGH(dst) THEN dst[i] := CHR(0) END
+  205    END CopyNm;
+  206  
+  207  PROCEDURE WrapExcept (body, handler: AST.Node): AST.Node;
+  208  (* M1: a body with an EXCEPT part is represented as one node so Lower
+  209     can add handler codegen in one place later.  The handler is retained
+  210     in the AST even while M1 lowers only the body. *)
+  211    VAR n: AST.Node;
+  212    BEGIN
+  213      n := AST.MakeNode(AST.NkExcept);
+  214      AST.SetChild(n, 0, body);
+  215      AST.SetChild(n, 1, handler);
+  216      RETURN n
+  217    END WrapExcept;
   218  
-  219  PROCEDURE InstActualKind (i: CARDINAL) : INTEGER;
-  220    BEGIN
-  221      IF i >= instN THEN RETURN 0 END;
-  222      RETURN instKind[i]
-  223    END InstActualKind;
+  219  PROCEDURE InInst () : BOOLEAN;
+  220    BEGIN RETURN instActive END InInst;
+  221  
+  222  PROCEDURE InstNameGet (VAR nm: SymTab.Name);
+  223    BEGIN CopyNm(instName, nm) END InstNameGet;
   224  
-  225  PROCEDURE InstActualVal (i: CARDINAL; VAR v: SymTab.Name);
-  226    VAR k: CARDINAL;
-  227    BEGIN
-  228      v[0] := CHR(0);
-  229      IF i >= instN THEN RETURN END;
-  230      k := 0;
-  231      WHILE (k <= HIGH(v)) AND (instVal[i][k] # CHR(0)) DO
-  232        v[k] := instVal[i][k]; INC(k)
-  233      END;
-  234      v[k] := CHR(0)
-  235    END InstActualVal;
-  236  
-  237  PROCEDURE InstActualMod (i: CARDINAL; VAR m: SymTab.Name);
-  238    VAR k: CARDINAL;
-  239    BEGIN
-  240      m[0] := CHR(0);
-  241      IF i >= instN THEN RETURN END;
-  242      k := 0;
-  243      WHILE (k <= HIGH(m)) AND (instMod[i][k] # CHR(0)) DO
-  244        m[k] := instMod[i][k]; INC(k)
-  245      END;
-  246      m[k] := CHR(0)
-  247    END InstActualMod;
-  248  
-  249  PROCEDURE InstAddActual (kind: INTEGER; t: SymTab.TypeIndex;
-  250                           val, m: ARRAY OF CHAR);
-  251    VAR k: CARDINAL;
-  252    BEGIN
-  253      IF instN > HIGH(instActual) THEN RETURN END;
-  254      instKind[instN] := kind; instActual[instN] := t;
-  255      k := 0;
-  256      WHILE (k <= HIGH(instVal[instN])) AND (val[k] # CHR(0)) DO
-  257        instVal[instN][k] := val[k]; INC(k)
-  258      END;
-  259      instVal[instN][k] := CHR(0);
-  260      k := 0;
-  261      WHILE (k <= HIGH(instMod[instN])) AND (m[k] # CHR(0)) DO
-  262        instMod[instN][k] := m[k]; INC(k)
-  263      END;
-  264      instMod[instN][k] := CHR(0);
-  265      INC(instN)
-  266    END InstAddActual;
-  267  
-  268  PROCEDURE InstEnd;
-  269    BEGIN instActive := FALSE; instN := 0 END InstEnd;
-  270  
-  271  PROCEDURE UnitNameGet (VAR nm: SymTab.Name);
-  272    BEGIN CopyNm(unitName, nm) END UnitNameGet;
-  273  
-  274  PROCEDURE UnitIsGeneric () : BOOLEAN;
-  275    BEGIN RETURN unitWasGen END UnitIsGeneric;
-  276  
-  277  PROCEDURE UnitIsDefModule () : BOOLEAN;
-  278    BEGIN RETURN unitWasDef END UnitIsDefModule;
-  279  
-  280  PROCEDURE IsTypeName (n: SymTab.Name): BOOLEAN;
-  281  (* TRUE when n denotes a type or a predeclared type name.  Used by the
-  282     procedure-type parameter list to tell a type-only entry from a
-  283     parameter name. *)
-  284    BEGIN
-  285      RETURN SymTab.Lookup(n)
-  286        AND ((SymTab.SymKind(n) = SymTab.KindType)
-  287          OR (SymTab.SymKind(n) = SymTab.KindPredef))
-  288    END IsTypeName;
+  225  PROCEDURE InstActualGet (i: CARDINAL) : SymTab.TypeIndex;
+  226    BEGIN
+  227      IF i >= instN THEN RETURN SymTab.InvalidType END;
+  228      RETURN instActual[i]
+  229    END InstActualGet;
+  230  
+  231  PROCEDURE InstBegin (name: ARRAY OF CHAR);
+  232    BEGIN instActive := TRUE; CopyNm(name, instName); instN := 0;
+  233      instFk := 0 END InstBegin;
+  234  
+  235  PROCEDURE InstActualKind (i: CARDINAL) : INTEGER;
+  236    BEGIN
+  237      IF i >= instN THEN RETURN 0 END;
+  238      RETURN instKind[i]
+  239    END InstActualKind;
+  240  
+  241  PROCEDURE InstActualVal (i: CARDINAL; VAR v: SymTab.Name);
+  242    VAR k: CARDINAL;
+  243    BEGIN
+  244      v[0] := CHR(0);
+  245      IF i >= instN THEN RETURN END;
+  246      k := 0;
+  247      WHILE (k <= HIGH(v)) AND (instVal[i][k] # CHR(0)) DO
+  248        v[k] := instVal[i][k]; INC(k)
+  249      END;
+  250      v[k] := CHR(0)
+  251    END InstActualVal;
+  252  
+  253  PROCEDURE InstActualMod (i: CARDINAL; VAR m: SymTab.Name);
+  254    VAR k: CARDINAL;
+  255    BEGIN
+  256      m[0] := CHR(0);
+  257      IF i >= instN THEN RETURN END;
+  258      k := 0;
+  259      WHILE (k <= HIGH(m)) AND (instMod[i][k] # CHR(0)) DO
+  260        m[k] := instMod[i][k]; INC(k)
+  261      END;
+  262      m[k] := CHR(0)
+  263    END InstActualMod;
+  264  
+  265  PROCEDURE InstAddActual (kind: INTEGER; t: SymTab.TypeIndex;
+  266                           val, m: ARRAY OF CHAR);
+  267    VAR k: CARDINAL;
+  268    BEGIN
+  269      IF instN > HIGH(instActual) THEN RETURN END;
+  270      instKind[instN] := kind; instActual[instN] := t;
+  271      k := 0;
+  272      WHILE (k <= HIGH(instVal[instN])) AND (val[k] # CHR(0)) DO
+  273        instVal[instN][k] := val[k]; INC(k)
+  274      END;
+  275      instVal[instN][k] := CHR(0);
+  276      k := 0;
+  277      WHILE (k <= HIGH(instMod[instN])) AND (m[k] # CHR(0)) DO
+  278        instMod[instN][k] := m[k]; INC(k)
+  279      END;
+  280      instMod[instN][k] := CHR(0);
+  281      INC(instN)
+  282    END InstAddActual;
+  283  
+  284  PROCEDURE InstEnd;
+  285    BEGIN instActive := FALSE; instN := 0 END InstEnd;
+  286  
+  287  PROCEDURE UnitNameGet (VAR nm: SymTab.Name);
+  288    BEGIN CopyNm(unitName, nm) END UnitNameGet;
   289  
-  290  PROCEDURE RefineSeen () : BOOLEAN;
-  291    BEGIN RETURN refSeen END RefineSeen;
+  290  PROCEDURE UnitIsGeneric () : BOOLEAN;
+  291    BEGIN RETURN unitWasGen END UnitIsGeneric;
   292  
-  293  PROCEDURE RefineIsDef () : BOOLEAN;
-  294    BEGIN RETURN refIsDef END RefineIsDef;
+  293  PROCEDURE UnitIsDefModule () : BOOLEAN;
+  294    BEGIN RETURN unitWasDef END UnitIsDefModule;
   295  
-  296  PROCEDURE RefineInst (VAR nm: SymTab.Name);
-  297    BEGIN CopyNm(refInst, nm) END RefineInst;
-  298  
-  299  PROCEDURE RefineGen (VAR nm: SymTab.Name);
-  300    BEGIN CopyNm(refGen, nm) END RefineGen;
-  301  
-  302  PROCEDURE RefineActualCount () : CARDINAL;
-  303    BEGIN RETURN refN END RefineActualCount;
-  304  
-  305  PROCEDURE RefineActualGet (i: CARDINAL) : SymTab.TypeIndex;
-  306    BEGIN
-  307      IF i >= refN THEN RETURN SymTab.InvalidType END;
-  308      RETURN refActual[i]
-  309    END RefineActualGet;
-  310  
-  311  PROCEDURE RefineActualKind (i: CARDINAL) : INTEGER;
-  312    BEGIN
-  313      IF i >= refN THEN RETURN 0 END;
-  314      RETURN refKind[i]
-  315    END RefineActualKind;
-  316  
-  317  PROCEDURE RefineActualMod (i: CARDINAL; VAR m: SymTab.Name);
-  318    VAR k: CARDINAL;
-  319    BEGIN
-  320      m[0] := CHR(0);
-  321      IF i >= refN THEN RETURN END;
-  322      k := 0;
-  323      WHILE (k <= HIGH(m)) AND (refMod[i][k] # CHR(0)) DO
-  324        m[k] := refMod[i][k]; INC(k)
-  325      END;
-  326      m[k] := CHR(0)
-  327    END RefineActualMod;
-  328  
-  329  PROCEDURE RefineActualVal (i: CARDINAL; VAR v: SymTab.Name);
-  330    VAR k: CARDINAL;
-  331    BEGIN
-  332      v[0] := CHR(0);
-  333      IF i >= refN THEN RETURN END;
-  334      k := 0;
-  335      WHILE (k <= HIGH(v)) AND (refVal[i][k] # CHR(0)) DO
-  336        v[k] := refVal[i][k]; INC(k)
-  337      END;
-  338      v[k] := CHR(0)
-  339    END RefineActualVal;
-  340  
-  341  PROCEDURE NoteLabel (nm: ARRAY OF CHAR);
-  342  (* Record a statement label; duplicate is 200. *)
-  343    VAR i: CARDINAL;
-  344    BEGIN
-  345      i := 0;
-  346      WHILE i < nLab DO
-  347        IF SymTab.Equal(labNm[i], nm) THEN SemError(200); RETURN END;
-  348        INC(i)
-  349      END;
-  350      IF nLab <= HIGH(labNm) THEN
-  351        CopyNm(nm, labNm[nLab]); INC(nLab)
-  352      ELSE SemError(230)  (* label table full: implementation limit *)
-  353      END
-  354    END NoteLabel;
-  355  
-  356  PROCEDURE NoteGoto (nm: ARRAY OF CHAR);
-  357    VAR i: CARDINAL;
-  358    BEGIN
-  359      i := 0;
-  360      WHILE i < nGot DO
-  361        IF SymTab.Equal(gotNm[i], nm) THEN RETURN END;
-  362        INC(i)
-  363      END;
-  364      IF nGot <= HIGH(gotNm) THEN
-  365        CopyNm(nm, gotNm[nGot]); INC(nGot)
-  366      ELSE SemError(230)  (* GOTO table full: implementation limit *)
-  367      END
-  368    END NoteGoto;
-  369  
-  370  PROCEDURE CheckGotos;
-  371  (* At a procedure's END: every GOTO must name a label in that procedure. *)
-  372    VAR i, j: CARDINAL; found: BOOLEAN;
-  373    BEGIN
-  374      i := 0;
-  375      WHILE i < nGot DO
-  376        found := FALSE; j := 0;
-  377        WHILE (j < nLab) AND NOT found DO
-  378          IF SymTab.Equal(labNm[j], gotNm[i]) THEN found := TRUE END;
-  379          INC(j)
-  380        END;
-  381        IF NOT found THEN SemError(201) END;
-  382        INC(i)
+  296  PROCEDURE IsTypeName (n: SymTab.Name): BOOLEAN;
+  297  (* TRUE when n denotes a type or a predeclared type name.  Used by the
+  298     procedure-type parameter list to tell a type-only entry from a
+  299     parameter name. *)
+  300    BEGIN
+  301      RETURN SymTab.Lookup(n)
+  302        AND ((SymTab.SymKind(n) = SymTab.KindType)
+  303          OR (SymTab.SymKind(n) = SymTab.KindPredef))
+  304    END IsTypeName;
+  305  
+  306  PROCEDURE RefineSeen () : BOOLEAN;
+  307    BEGIN RETURN refSeen END RefineSeen;
+  308  
+  309  PROCEDURE RefineIsDef () : BOOLEAN;
+  310    BEGIN RETURN refIsDef END RefineIsDef;
+  311  
+  312  PROCEDURE RefineInst (VAR nm: SymTab.Name);
+  313    BEGIN CopyNm(refInst, nm) END RefineInst;
+  314  
+  315  PROCEDURE RefineGen (VAR nm: SymTab.Name);
+  316    BEGIN CopyNm(refGen, nm) END RefineGen;
+  317  
+  318  PROCEDURE RefineActualCount () : CARDINAL;
+  319    BEGIN RETURN refN END RefineActualCount;
+  320  
+  321  PROCEDURE RefineActualGet (i: CARDINAL) : SymTab.TypeIndex;
+  322    BEGIN
+  323      IF i >= refN THEN RETURN SymTab.InvalidType END;
+  324      RETURN refActual[i]
+  325    END RefineActualGet;
+  326  
+  327  PROCEDURE RefineActualKind (i: CARDINAL) : INTEGER;
+  328    BEGIN
+  329      IF i >= refN THEN RETURN 0 END;
+  330      RETURN refKind[i]
+  331    END RefineActualKind;
+  332  
+  333  PROCEDURE RefineActualMod (i: CARDINAL; VAR m: SymTab.Name);
+  334    VAR k: CARDINAL;
+  335    BEGIN
+  336      m[0] := CHR(0);
+  337      IF i >= refN THEN RETURN END;
+  338      k := 0;
+  339      WHILE (k <= HIGH(m)) AND (refMod[i][k] # CHR(0)) DO
+  340        m[k] := refMod[i][k]; INC(k)
+  341      END;
+  342      m[k] := CHR(0)
+  343    END RefineActualMod;
+  344  
+  345  PROCEDURE RefineActualVal (i: CARDINAL; VAR v: SymTab.Name);
+  346    VAR k: CARDINAL;
+  347    BEGIN
+  348      v[0] := CHR(0);
+  349      IF i >= refN THEN RETURN END;
+  350      k := 0;
+  351      WHILE (k <= HIGH(v)) AND (refVal[i][k] # CHR(0)) DO
+  352        v[k] := refVal[i][k]; INC(k)
+  353      END;
+  354      v[k] := CHR(0)
+  355    END RefineActualVal;
+  356  
+  357  PROCEDURE NoteLabel (nm: ARRAY OF CHAR);
+  358  (* Record a statement label; duplicate is 200. *)
+  359    VAR i: CARDINAL;
+  360    BEGIN
+  361      i := 0;
+  362      WHILE i < nLab DO
+  363        IF SymTab.Equal(labNm[i], nm) THEN SemError(200); RETURN END;
+  364        INC(i)
+  365      END;
+  366      IF nLab <= HIGH(labNm) THEN
+  367        CopyNm(nm, labNm[nLab]); INC(nLab)
+  368      ELSE SemError(230)  (* label table full: implementation limit *)
+  369      END
+  370    END NoteLabel;
+  371  
+  372  PROCEDURE NoteGoto (nm: ARRAY OF CHAR);
+  373    VAR i: CARDINAL;
+  374    BEGIN
+  375      i := 0;
+  376      WHILE i < nGot DO
+  377        IF SymTab.Equal(gotNm[i], nm) THEN RETURN END;
+  378        INC(i)
+  379      END;
+  380      IF nGot <= HIGH(gotNm) THEN
+  381        CopyNm(nm, gotNm[nGot]); INC(nGot)
+  382      ELSE SemError(230)  (* GOTO table full: implementation limit *)
   383      END
-  384    END CheckGotos;
+  384    END NoteGoto;
   385  
-  386  PROCEDURE FlushPend;
-  387  (* Emit module-level globals whose forward type is now resolved. *)
-  388    VAR k: CARDINAL;
+  386  PROCEDURE CheckGotos;
+  387  (* At a procedure's END: every GOTO must name a label in that procedure. *)
+  388    VAR i, j: CARDINAL; found: BOOLEAN;
   389    BEGIN
-  390      k := 0;
-  391      WHILE k < nPendVar DO
-  392        INC(k)
-  393      END;
-  394      nPendVar := 0
-  395    END FlushPend;
-  396  
-  397  PROCEDURE AstAppend (kind: INTEGER; VAR head, tail: AST.Node;
-  398                       item: AST.Node);
-  399  (* Appends `item` to a chunked sequence: each node holds up to
-  400     AST.MaxChild-1 items; child[MaxChild-1] continues into the next
-  401     chunk.  Unbounded, so blocks/decl sequences are not capped at 8. *)
-  402    VAR n: AST.Node;
-  403    BEGIN
-  404      IF item = AST.NoNode THEN RETURN END;
-  405      IF head = AST.NoNode THEN
-  406        head := AST.MakeNode(kind); tail := head
-  407      END;
-  408      IF AST.NChild(tail) >= AST.MaxChild - 1 THEN
-  409        n := AST.MakeNode(kind);
-  410        AST.SetChild(tail, AST.MaxChild - 1, n);
-  411        tail := n
-  412      END;
-  413      AST.SetChild(tail, AST.NChild(tail), item)
-  414    END AstAppend;
-  415  
-  416  PROCEDURE AstCallNode (callee: AST.Node) : AST.Node;
-  417  (* Builds NkCall(callee, actuals...) from astArgs/astNArgs.  The actuals
-  418     are a chunked sequence (AstAppend): a call can have more than
-  419     MaxChild-1 arguments (the generic ArgList has 9), and SetChild would
-  420     silently drop the tail.  NkBlock marks the continuation chunks. *)
-  421    VAR n, tail: AST.Node; j: CARDINAL;
-  422    BEGIN
-  423      n := AST.MakeNode(AST.NkCall);
-  424      AST.SetChild(n, 0, callee);
-  425      tail := n;
-  426      j := 0;
-  427      WHILE j < astNArgs DO
-  428        AstAppend(AST.NkBlock, n, tail, astArgs[j]);
-  429        INC(j)
-  430      END;
-  431      RETURN n
-  432    END AstCallNode;
-  433  
-  434  
-  435  
-  436  PROCEDURE GetUnit (): AST.Node;
-  437  (* The most recently parsed unit's AST root (for the Lower comparison). *)
+  390      i := 0;
+  391      WHILE i < nGot DO
+  392        found := FALSE; j := 0;
+  393        WHILE (j < nLab) AND NOT found DO
+  394          IF SymTab.Equal(labNm[j], gotNm[i]) THEN found := TRUE END;
+  395          INC(j)
+  396        END;
+  397        IF NOT found THEN SemError(201) END;
+  398        INC(i)
+  399      END
+  400    END CheckGotos;
+  401  
+  402  PROCEDURE FlushPend;
+  403  (* Emit module-level globals whose forward type is now resolved. *)
+  404    VAR k: CARDINAL;
+  405    BEGIN
+  406      k := 0;
+  407      WHILE k < nPendVar DO
+  408        INC(k)
+  409      END;
+  410      nPendVar := 0
+  411    END FlushPend;
+  412  
+  413  PROCEDURE AstAppend (kind: INTEGER; VAR head, tail: AST.Node;
+  414                       item: AST.Node);
+  415  (* Appends `item` to a chunked sequence: each node holds up to
+  416     AST.MaxChild-1 items; child[MaxChild-1] continues into the next
+  417     chunk.  Unbounded, so blocks/decl sequences are not capped at 8. *)
+  418    VAR n: AST.Node;
+  419    BEGIN
+  420      IF item = AST.NoNode THEN RETURN END;
+  421      IF head = AST.NoNode THEN
+  422        head := AST.MakeNode(kind); tail := head
+  423      END;
+  424      IF AST.NChild(tail) >= AST.MaxChild - 1 THEN
+  425        n := AST.MakeNode(kind);
+  426        AST.SetChild(tail, AST.MaxChild - 1, n);
+  427        tail := n
+  428      END;
+  429      AST.SetChild(tail, AST.NChild(tail), item)
+  430    END AstAppend;
+  431  
+  432  PROCEDURE AstCallNode (callee: AST.Node) : AST.Node;
+  433  (* Builds NkCall(callee, actuals...) from astArgs/astNArgs.  The actuals
+  434     are a chunked sequence (AstAppend): a call can have more than
+  435     MaxChild-1 arguments (the generic ArgList has 9), and SetChild would
+  436     silently drop the tail.  NkBlock marks the continuation chunks. *)
+  437    VAR n, tail: AST.Node; j: CARDINAL;
   438    BEGIN
-  439      RETURN astUnit
-  440    END GetUnit;
-  441  
-  442  PROCEDURE SetTwoPhase (b: BOOLEAN);
-  443  (* Driver switch for the two-phase parse probe (milestone 1). *)
-  444    BEGIN
-  445      twoPhaseParse := b
-  446    END SetTwoPhase;
-  447  
-  448  PROCEDURE TokIs (kw: ARRAY OF CHAR): BOOLEAN;
-  449  (* The current lookahead token's source text equals kw.  Compares text,
-  450     not token codes, so grammar renumbering cannot desync the skipper. *)
-  451    VAR tok: ARRAY [0 .. 63] OF CHAR;
-  452    BEGIN
-  453      M2S.GetName(M2S.nextPos, M2S.nextLen, tok);
-  454      RETURN SymTab.Equal(tok, kw)
-  455    END TokIs;
-  456  
-  457  PROCEDURE Adv;
-  458  (* Advance one token: exactly the parser frame's Get for a grammar
-  459     without pragmas (its pragma branch is empty and the scanner never
-  460     returns a token above maxT, so the repeat loop runs once).  A
-  461     separate name because the frame's Get is declared later in this
-  462     module: a bare Get here would bind the imported M2S.Get (which takes
-  463     a parameter) under single-pass compilers. *)
-  464    BEGIN
-  465      M2S.Get(sym);
-  466      INC(errDist)
-  467    END Adv;
-  468  
-  469  PROCEDURE ConsCode (nm: ARRAY OF CHAR): INTEGER;
-  470  (* Constraint name -> code: 0 none, 1 ORDINAL, 2 INTEGER, 3 REAL. *)
-  471    BEGIN
-  472      IF SymTab.Equal(nm, "ORDINAL") THEN RETURN 1
-  473      ELSIF SymTab.Equal(nm, "INTEGER") THEN RETURN 2
-  474      ELSIF SymTab.Equal(nm, "REAL") THEN RETURN 3
-  475      ELSIF SymTab.Equal(nm, "POINTER") THEN RETURN 4
-  476      ELSIF SymTab.Equal(nm, "SCALAR") THEN RETURN 5
-  477      END;
-  478      RETURN 0
-  479    END ConsCode;
-  480  
-  481  PROCEDURE ConsOk (cons: INTEGER; t: SymTab.TypeIndex): BOOLEAN;
-  482  (* TRUE when t satisfies the constraint code. *)
-  483    BEGIN
-  484      IF cons = 0 THEN RETURN TRUE
-  485      ELSIF cons = 1 THEN RETURN SymTab.IsOrdinal(t)
-  486      ELSIF cons = 2 THEN
-  487        RETURN (SymTab.ClassOf(t) = SymTab.ClInt)
-  488            OR (SymTab.ClassOf(t) = SymTab.ClByte)
-  489            OR (SymTab.ClassOf(t) = SymTab.ClSByte)
-  490            OR (SymTab.ClassOf(t) = SymTab.ClWord16)
-  491            OR (SymTab.ClassOf(t) = SymTab.ClSWord16)
-  492      ELSIF cons = 3 THEN RETURN SymTab.ClassOf(t) = SymTab.ClReal
-  493      ELSIF cons = 4 THEN RETURN SymTab.ClassOf(t) = SymTab.ClPtr
-  494      ELSIF cons = 5 THEN
-  495        RETURN (SymTab.ClassOf(t) = SymTab.ClInt)
-  496            OR (SymTab.ClassOf(t) = SymTab.ClChar)
-  497            OR (SymTab.ClassOf(t) = SymTab.ClBool)
-  498            OR (SymTab.ClassOf(t) = SymTab.ClEnum)
-  499            OR (SymTab.ClassOf(t) = SymTab.ClUChar)
-  500            OR (SymTab.ClassOf(t) = SymTab.ClByte)
-  501            OR (SymTab.ClassOf(t) = SymTab.ClSByte)
-  502            OR (SymTab.ClassOf(t) = SymTab.ClWord16)
-  503            OR (SymTab.ClassOf(t) = SymTab.ClSWord16)
-  504            OR (SymTab.ClassOf(t) = SymTab.ClReal)
-  505      END;
-  506      RETURN TRUE
-  507    END ConsOk;
-  508  
-  509  PROCEDURE OrdClass (t: SymTab.TypeIndex): BOOLEAN;
-  510  (* TRUE for scalar ordinal classes (int/char/bool/enum/uchar); a
-  511     conversion between two of these is representation-preserving, so its
-  512     folded value equals the operand's. *)
-  513    VAR c: INTEGER;
-  514    BEGIN
-  515      c := SymTab.ClassOf(t);
-  516      RETURN (c = SymTab.ClInt) OR (c = SymTab.ClChar) OR (c = SymTab.ClBool)
-  517          OR (c = SymTab.ClEnum) OR (c = SymTab.ClUChar)
-  518          OR (c = SymTab.ClByte) OR (c = SymTab.ClSByte)
-  519          OR (c = SymTab.ClWord16) OR (c = SymTab.ClSWord16)
-  520    END OrdClass;
-  521  
-  522  PROCEDURE NoteSpan (pn: SymTab.Name; start: M2S.INT32): BOOLEAN;
-  523  (* Records an outermost body span for the re-parse pass (milestone 2).
-  524     FALSE when the span table is full (an implementation limit): the
-  525     caller then parses the body inline instead of dropping it. *)
-  526    BEGIN
-  527      IF nSpans > HIGH(spanName) THEN RETURN FALSE END;
-  528      CopyNm(pn, spanName[nSpans]);
-  529      spanStart[nSpans] := start;
-  530      spanIdx[nSpans] := SymTab.DeferBody();
-  531      INC(nSpans);
-  532      RETURN TRUE
-  533    END NoteSpan;
-  534  
-  535  PROCEDURE Openers (): BOOLEAN;
-  536  (* TRUE when the current token opens a block that must be closed by an
-  537     END (BEGIN is excluded: a block's BEGIN shares the declaration END;
-  538     REPEAT..UNTIL and EXIT/RETURN need no END). *)
-  539    BEGIN
-  540      RETURN TokIs("MODULE") OR TokIs("PROCEDURE") OR TokIs("CLASS")
-  541         OR TokIs("RECORD") OR TokIs("IF") OR TokIs("CASE")
-  542         OR TokIs("WHILE") OR TokIs("FOR") OR TokIs("LOOP")
-  543         OR TokIs("WITH")
-  544    END Openers;
-  545  
-  546  PROCEDURE DeferSkip (pn: SymTab.Name): BOOLEAN;
-  547  (* Phase 1 of the deferral: skip the body starting at the current token
-  548     (the first token after the heading's ';') up to the matching END,
-  549     verify the END's name, and LEAVE the scanner positioned exactly at
-  550     that END (so Block's trailing "END" ident consumes it for real), with
-  551     the span recorded for the re-parse pass.  On any inconsistency,
-  552     restore the scanner and return FALSE so the caller parses normally. *)
-  553    VAR depth, guard: CARDINAL;
-  554      nm: SymTab.Name;
-  555      ok: BOOLEAN;
-  556      start, endPos: M2S.INT32;
-  557    BEGIN
-  558      deferredBody := FALSE;
-  559      (* table full (an implementation limit): parse the body inline now,
-  560         before touching the scanner, with a clear error. *)
-  561      IF nSpans > HIGH(spanName) THEN
-  562        SemError(230);
-  563        RETURN FALSE
-  564      END;
-  565      start := M2S.nextPos;
-  566      M2S.PushPos;
-  567      depth := 0; guard := 0; ok := TRUE;
-  568      LOOP
-  569        IF sym = 0 THEN ok := FALSE; EXIT END;
-  570        IF TokIs("END") THEN
-  571          IF depth = 0 THEN EXIT END;
-  572          DEC(depth)
-  573        ELSIF Openers() THEN
-  574          INC(depth)
-  575        END;
-  576        Adv;
-  577        INC(guard);
-  578        IF guard > 1000000 THEN ok := FALSE; EXIT END
-  579      END;
-  580      IF ok THEN
-  581        (* sym is the matching END; check the name after it, then seek back
-  582           so Block sees END (its "END" ident then consumes it for real). *)
-  583        endPos := M2S.nextPos;
-  584        Adv;
-  585        M2S.GetName(M2S.nextPos, M2S.nextLen, nm);
-  586        IF (sym = 0) OR NOT SymTab.Equal(nm, pn) THEN ok := FALSE END;
-  587        IF ok THEN
-  588          M2S.SeekTo(endPos); Adv
-  589        END
-  590      END;
-  591      IF ok THEN
-  592        IF NOT NoteSpan(pn, start) THEN
-  593          (* defensive: capacity is checked at entry, so this is unreachable *)
-  594          SemError(230);
-  595          RETURN FALSE
-  596        END;
-  597        spanTy[nSpans - 1] := Lower.CurScopeProc();
-  598        spanNode[nSpans - 1] := curProcNode;
-  599        M2S.DropPos;   (* keep the scanner at END; discard the snapshot *)
-  600        deferredBody := TRUE;
-  601        RETURN TRUE
-  602      ELSE
-  603        M2S.PopPos;
-  604        FileIO.WriteString(FileIO.StdOut, "twophase defer mismatch in ");
-  605        FileIO.WriteString(FileIO.StdOut, pn);
-  606        FileIO.WriteLn(FileIO.StdOut);
-  607        RETURN FALSE
-  608      END
-  609    END DeferSkip;
-  610  
-  611  CHARACTERS
-  612    eol      = CHR(13) .
-  613    lf       = CHR(10) .
-  614    letter   = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz" .
-  615    digit    = "0123456789" .
-  616    hexDigit = digit + "ABCDEFabcdef" .
-  617    noQuote1 = ANY - "'" - eol .
-  618    noQuote2 = ANY - '"' - eol .
-  619  
-  620  IGNORE CHR(9) .. CHR(13)
-  621  
-  622  COMMENTS FROM "(*" TO "*)" NESTED
-  623  COMMENTS FROM "//" TO lf
-  624  
-  625  TOKENS
-  626    ident   = ( letter | "_" ) { letter | digit | "_" } .
-  627    integer = digit { digit }
-  628            | digit { digit } CONTEXT("..")
-  629            | "0x" hexDigit { hexDigit }
-  630            | "0X" hexDigit { hexDigit } .
-  631    real    = digit { digit } "." { digit }
-  632              [ ( "E" | "e" ) [ "+" | "-" ] digit { digit } ] .
-  633    string  = "'" { noQuote1 } "'"
-  634            | '"' { noQuote2 } '"' .
-  635    charConst = digit { digit } ( "C" | "c" ) .
-  636    ustring = ( "U" | "u" ) ( "'" { noQuote1 } "'" | '"' { noQuote2 } '"' ) .
+  439      n := AST.MakeNode(AST.NkCall);
+  440      AST.SetChild(n, 0, callee);
+  441      tail := n;
+  442      j := 0;
+  443      WHILE j < astNArgs DO
+  444        AstAppend(AST.NkBlock, n, tail, astArgs[j]);
+  445        INC(j)
+  446      END;
+  447      RETURN n
+  448    END AstCallNode;
+  449  
+  450  
+  451  
+  452  PROCEDURE GetUnit (): AST.Node;
+  453  (* The most recently parsed unit's AST root (for the Lower comparison). *)
+  454    BEGIN
+  455      RETURN astUnit
+  456    END GetUnit;
+  457  
+  458  PROCEDURE SetTwoPhase (b: BOOLEAN);
+  459  (* Driver switch for the two-phase parse probe (milestone 1). *)
+  460    BEGIN
+  461      twoPhaseParse := b
+  462    END SetTwoPhase;
+  463  
+  464  PROCEDURE TokIs (kw: ARRAY OF CHAR): BOOLEAN;
+  465  (* The current lookahead token's source text equals kw.  Compares text,
+  466     not token codes, so grammar renumbering cannot desync the skipper. *)
+  467    VAR tok: ARRAY [0 .. 63] OF CHAR;
+  468    BEGIN
+  469      M2S.GetName(M2S.nextPos, M2S.nextLen, tok);
+  470      RETURN SymTab.Equal(tok, kw)
+  471    END TokIs;
+  472  
+  473  PROCEDURE Adv;
+  474  (* Advance one token: exactly the parser frame's Get for a grammar
+  475     without pragmas (its pragma branch is empty and the scanner never
+  476     returns a token above maxT, so the repeat loop runs once).  A
+  477     separate name because the frame's Get is declared later in this
+  478     module: a bare Get here would bind the imported M2S.Get (which takes
+  479     a parameter) under single-pass compilers. *)
+  480    BEGIN
+  481      M2S.Get(sym);
+  482      INC(errDist)
+  483    END Adv;
+  484  
+  485  PROCEDURE ConsCode (nm: ARRAY OF CHAR): INTEGER;
+  486  (* Constraint name -> code: 0 none, 1 ORDINAL, 2 INTEGER, 3 REAL. *)
+  487    BEGIN
+  488      IF SymTab.Equal(nm, "ORDINAL") THEN RETURN 1
+  489      ELSIF SymTab.Equal(nm, "INTEGER") THEN RETURN 2
+  490      ELSIF SymTab.Equal(nm, "REAL") THEN RETURN 3
+  491      ELSIF SymTab.Equal(nm, "POINTER") THEN RETURN 4
+  492      ELSIF SymTab.Equal(nm, "SCALAR") THEN RETURN 5
+  493      END;
+  494      RETURN 0
+  495    END ConsCode;
+  496  
+  497  PROCEDURE ConsOk (cons: INTEGER; t: SymTab.TypeIndex): BOOLEAN;
+  498  (* TRUE when t satisfies the constraint code. *)
+  499    BEGIN
+  500      IF cons = 0 THEN RETURN TRUE
+  501      ELSIF cons = 1 THEN RETURN SymTab.IsOrdinal(t)
+  502      ELSIF cons = 2 THEN
+  503        RETURN (SymTab.ClassOf(t) = SymTab.ClInt)
+  504            OR (SymTab.ClassOf(t) = SymTab.ClByte)
+  505            OR (SymTab.ClassOf(t) = SymTab.ClSByte)
+  506            OR (SymTab.ClassOf(t) = SymTab.ClWord16)
+  507            OR (SymTab.ClassOf(t) = SymTab.ClSWord16)
+  508      ELSIF cons = 3 THEN RETURN SymTab.ClassOf(t) = SymTab.ClReal
+  509      ELSIF cons = 4 THEN RETURN SymTab.ClassOf(t) = SymTab.ClPtr
+  510      ELSIF cons = 5 THEN
+  511        RETURN (SymTab.ClassOf(t) = SymTab.ClInt)
+  512            OR (SymTab.ClassOf(t) = SymTab.ClChar)
+  513            OR (SymTab.ClassOf(t) = SymTab.ClBool)
+  514            OR (SymTab.ClassOf(t) = SymTab.ClEnum)
+  515            OR (SymTab.ClassOf(t) = SymTab.ClUChar)
+  516            OR (SymTab.ClassOf(t) = SymTab.ClByte)
+  517            OR (SymTab.ClassOf(t) = SymTab.ClSByte)
+  518            OR (SymTab.ClassOf(t) = SymTab.ClWord16)
+  519            OR (SymTab.ClassOf(t) = SymTab.ClSWord16)
+  520            OR (SymTab.ClassOf(t) = SymTab.ClReal)
+  521      END;
+  522      RETURN TRUE
+  523    END ConsOk;
+  524  
+  525  PROCEDURE OrdClass (t: SymTab.TypeIndex): BOOLEAN;
+  526  (* TRUE for scalar ordinal classes (int/char/bool/enum/uchar); a
+  527     conversion between two of these is representation-preserving, so its
+  528     folded value equals the operand's. *)
+  529    VAR c: INTEGER;
+  530    BEGIN
+  531      c := SymTab.ClassOf(t);
+  532      RETURN (c = SymTab.ClInt) OR (c = SymTab.ClChar) OR (c = SymTab.ClBool)
+  533          OR (c = SymTab.ClEnum) OR (c = SymTab.ClUChar)
+  534          OR (c = SymTab.ClByte) OR (c = SymTab.ClSByte)
+  535          OR (c = SymTab.ClWord16) OR (c = SymTab.ClSWord16)
+  536    END OrdClass;
+  537  
+  538  PROCEDURE NoteSpan (pn: SymTab.Name; start: M2S.INT32): BOOLEAN;
+  539  (* Records an outermost body span for the re-parse pass (milestone 2).
+  540     FALSE when the span table is full (an implementation limit): the
+  541     caller then parses the body inline instead of dropping it. *)
+  542    BEGIN
+  543      IF nSpans > HIGH(spanName) THEN RETURN FALSE END;
+  544      CopyNm(pn, spanName[nSpans]);
+  545      spanStart[nSpans] := start;
+  546      spanIdx[nSpans] := SymTab.DeferBody();
+  547      INC(nSpans);
+  548      RETURN TRUE
+  549    END NoteSpan;
+  550  
+  551  PROCEDURE Openers (): BOOLEAN;
+  552  (* TRUE when the current token opens a block that must be closed by an
+  553     END (BEGIN is excluded: a block's BEGIN shares the declaration END;
+  554     REPEAT..UNTIL and EXIT/RETURN need no END). *)
+  555    BEGIN
+  556      RETURN TokIs("MODULE") OR TokIs("PROCEDURE") OR TokIs("CLASS")
+  557         OR TokIs("RECORD") OR TokIs("IF") OR TokIs("CASE")
+  558         OR TokIs("WHILE") OR TokIs("FOR") OR TokIs("LOOP")
+  559         OR TokIs("WITH")
+  560    END Openers;
+  561  
+  562  PROCEDURE DeferSkip (pn: SymTab.Name): BOOLEAN;
+  563  (* Phase 1 of the deferral: skip the body starting at the current token
+  564     (the first token after the heading's ';') up to the matching END,
+  565     verify the END's name, and LEAVE the scanner positioned exactly at
+  566     that END (so Block's trailing "END" ident consumes it for real), with
+  567     the span recorded for the re-parse pass.  On any inconsistency,
+  568     restore the scanner and return FALSE so the caller parses normally. *)
+  569    VAR depth, guard: CARDINAL;
+  570      nm: SymTab.Name;
+  571      ok: BOOLEAN;
+  572      start, endPos: M2S.INT32;
+  573    BEGIN
+  574      deferredBody := FALSE;
+  575      (* table full (an implementation limit): parse the body inline now,
+  576         before touching the scanner, with a clear error. *)
+  577      IF nSpans > HIGH(spanName) THEN
+  578        SemError(230);
+  579        RETURN FALSE
+  580      END;
+  581      start := M2S.nextPos;
+  582      M2S.PushPos;
+  583      depth := 0; guard := 0; ok := TRUE;
+  584      LOOP
+  585        IF sym = 0 THEN ok := FALSE; EXIT END;
+  586        IF TokIs("END") THEN
+  587          IF depth = 0 THEN EXIT END;
+  588          DEC(depth)
+  589        ELSIF Openers() THEN
+  590          INC(depth)
+  591        END;
+  592        Adv;
+  593        INC(guard);
+  594        IF guard > 1000000 THEN ok := FALSE; EXIT END
+  595      END;
+  596      IF ok THEN
+  597        (* sym is the matching END; check the name after it, then seek back
+  598           so Block sees END (its "END" ident then consumes it for real). *)
+  599        endPos := M2S.nextPos;
+  600        Adv;
+  601        M2S.GetName(M2S.nextPos, M2S.nextLen, nm);
+  602        IF (sym = 0) OR NOT SymTab.Equal(nm, pn) THEN ok := FALSE END;
+  603        IF ok THEN
+  604          M2S.SeekTo(endPos); Adv
+  605        END
+  606      END;
+  607      IF ok THEN
+  608        IF NOT NoteSpan(pn, start) THEN
+  609          (* defensive: capacity is checked at entry, so this is unreachable *)
+  610          SemError(230);
+  611          RETURN FALSE
+  612        END;
+  613        spanTy[nSpans - 1] := Lower.CurScopeProc();
+  614        spanNode[nSpans - 1] := curProcNode;
+  615        M2S.DropPos;   (* keep the scanner at END; discard the snapshot *)
+  616        deferredBody := TRUE;
+  617        RETURN TRUE
+  618      ELSE
+  619        M2S.PopPos;
+  620        FileIO.WriteString(FileIO.StdOut, "twophase defer mismatch in ");
+  621        FileIO.WriteString(FileIO.StdOut, pn);
+  622        FileIO.WriteLn(FileIO.StdOut);
+  623        RETURN FALSE
+  624      END
+  625    END DeferSkip;
+  626  
+  627  CHARACTERS
+  628    eol      = CHR(13) .
+  629    lf       = CHR(10) .
+  630    letter   = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz" .
+  631    digit    = "0123456789" .
+  632    hexDigit = digit + "ABCDEFabcdef" .
+  633    noQuote1 = ANY - "'" - eol .
+  634    noQuote2 = ANY - '"' - eol .
+  635  
+  636  IGNORE CHR(9) .. CHR(13)
   637  
-  638  PRODUCTIONS
-  639    M2
-  640      = (. astCur := AST.NoNode; astStmt := AST.NoNode; astDecl := AST.NoNode; astImp := AST.NoNode; astImpTail := AST.NoNode;
-  641                                             astImp := AST.NoNode;
-  642                                             astImpTail := AST.NoNode;
-  643                                             nSpans := 0;
-  644                                             SymTab.DeferReset; .)
-  645        Unit "."                          (. IF SymTab.TypesOverflow() THEN
-  646                                               SemError(230)  (* MaxTypes *)
-  647                                             END; .) .
-  648    (* Units: program modules compile fully; DEFINITION and
-  649       IMPLEMENTATION modules parse + check now but lower in step 4
-  650       (each ends with one 230); same for nested local modules. *)
-  651    (* Generics (Increment 1): formal and actual parameters.  Formals are
-  652       TYPE parameters only; actuals are type identifiers. *)
-  653    GenericFormals
-  654      = "(" GenericFormal { ";" GenericFormal } ")" .
-  655    GenericFormal                         (. VAR nm: SymTab.Name; vt: SymTab.TypeIndex;
-  656                                               names: ARRAY [0 .. 15] OF SymTab.Name;
-  657                                               nn, k: CARDINAL;
-  658                                               mmod: SymTab.Name;
-  659                                               quid, qdep: CARDINAL;
-  660                                               qres: SymTab.TypeIndex;
-  661                                               qext: BOOLEAN;
-  662                                               cons: INTEGER;
-  663                                               cn: SymTab.Name;
-  664                                               isTypeFormal: BOOLEAN; .)
-  665      =                                   (. nn := 0; .)
-  666        GetIdent<nm>                      (. k := 0;
-  667                                             WHILE (k <= HIGH(names[nn])) AND (nm[k] # CHR(0)) DO
-  668                                               names[nn][k] := nm[k]; INC(k) END;
-  669                                             names[nn][k] := CHR(0); INC(nn); .)
-  670        { "," GetIdent<nm>                (. k := 0;
-  671                                             WHILE (k <= HIGH(names[nn])) AND (nm[k] # CHR(0)) DO
-  672                                               names[nn][k] := nm[k]; INC(k) END;
-  673                                             names[nn][k] := CHR(0); INC(nn); .) }
-  674        ":"                               (. vt := SymTab.InvalidType; isTypeFormal := FALSE; .)
-  675        ( "TYPE"                          (. isTypeFormal := TRUE; .)
-  676          [ "(" GetIdent<cn> ")"          (. cons := ConsCode(cn); .) ]
-  677        | ProcType<vt>                    (. isTypeFormal := FALSE; .)
-  678        | TypeIdent<vt> )                 (. k := 0;
-  679                                             WHILE k < nn DO
-  680                                               IF isTypeFormal THEN
-  681                                                 IF instActive THEN
-  682                                                   (* constraint: a type
-  683                                                      formal needs a type
-  684                                                      actual that satisfies
-  685                                                      the declared constraint *)
-  686                                                   IF InstActualKind(instFk) # 0 THEN
-  687                                                     SemError(233)
-  688                                                   ELSIF NOT ConsOk(cons, InstActualGet(instFk)) THEN
-  689                                                     SemError(233)
-  690                                                   ELSIF NOT SymTab.EnterTypeParamBound(names[k], InstActualGet(instFk)) THEN
-  691                                                     SemError(200) END
-  692                                                 ELSIF NOT SymTab.EnterTypeParam(names[k]) THEN
-  693                                                   SemError(200) END
-  694                                               ELSIF SymTab.ClassOf(vt) = SymTab.ClProc THEN
-  695                                                 (* procedure formal *)
-  696                                                 IF instActive THEN
-  697                                                   IF InstActualKind(instFk) # 2 THEN
-  698                                                     SemError(233) END;
-  699                                                   InstActualMod(instFk, mmod);
-  700                                                   InstActualVal(instFk, nm);
-  701                                                   IF NOT SymTab.AliasProc(names[k], mmod, nm) THEN
-  702                                                     SemError(201)
-  703                                                   ELSIF SymTab.QualProcInfo(mmod, nm, quid, qdep, qres, qext) THEN
-  704                                                     Lower.AliasProc(names[k], quid, qres, qdep, qext)
-  705                                                   END
-  706                                                 ELSE
-  707                                                   (* template: a callable
-  708                                                      placeholder of the
-  709                                                      formal's proc type *)
-  710                                                   IF NOT SymTab.Enter(names[k], SymTab.KindVar) THEN
-  711                                                     SemError(200) END;
-  712                                                   SymTab.SetSymType(names[k], vt)
-  713                                                 END
-  714                                               ELSE
-  715                                                 (* constraint: a value
-  716                                                    formal needs a value
-  717                                                    actual *)
-  718                                                 IF instActive AND (InstActualKind(instFk) # 1) THEN
-  719                                                   SemError(233) END;
-  720                                                 IF NOT SymTab.Enter(names[k], SymTab.KindConst) THEN
-  721                                                   SemError(200) END;
-  722                                                 SymTab.SetSymType(names[k], vt);
-  723                                                 IF instActive THEN
-  724                                                   InstActualVal(instFk, nm);
-  725                                                   SymTab.SetSymVal(names[k], nm)
-  726                                                 ELSE SymTab.SetSymVal(names[k], "0")
-  727                                                 END
-  728                                               END;
-  729                                               INC(instFk); INC(k)
-  730                                             END; .) .
-  731    Actuals
-  732      = Actual { "," Actual } .
-  733    Actual                                (. VAR at: SymTab.TypeIndex;
-  734                                               nm: SymTab.Name;
-  735                                               s: ARRAY [0 .. 255] OF CHAR;
-  736                                               qv: QbeGen.QVal;
-  737                                               isCh, isV: BOOLEAN;
-  738                                               aKind: INTEGER;
-  739                                               amod: SymTab.Name;
-  740                                               nm2: SymTab.Name;
-  741                                               qu, qd: CARDINAL;
-  742                                               qr: SymTab.TypeIndex;
-  743                                               qe: BOOLEAN;
-  744                                               k: CARDINAL; .)
-  745      =                                   (. isV := FALSE; at := SymTab.InvalidType;
-  746                                             nm[0] := CHR(0); nm2[0] := CHR(0);
-  747                                             aKind := 0; amod[0] := CHR(0); .)
-  748        ( integer                         (. LexString(s); QbeGen.NormInt(s, qv);
-  749                                             isV := TRUE; aKind := 1; at := SymTab.IntType();
-  750                                             CopyNm(qv, nm); .)
-  751        | charConst                       (. LexString(s); QbeGen.NormLit(s, qv, isCh);
-  752                                             isV := TRUE; aKind := 1; at := SymTab.CharType();
-  753                                             CopyNm(qv, nm); .)
-  754        | GetIdent<nm> [ "." GetIdent<nm2> ]
-  755                                          (. isV := FALSE; at := SymTab.InvalidType;
-  756                                             aKind := 0; amod[0] := CHR(0);
-  757                                             IF nm2[0] # CHR(0) THEN
-  758                                               (* qualified actual Mod.Name:
-  759                                                  a nested instance's type
-  760                                                  (Mod.Type) or a procedure
-  761                                                  (Mod.Proc); no import
-  762                                                  needed *)
-  763                                               IF SymTab.QualProcInfo(nm, nm2,
-  764                                                    qu, qd, qr, qe) THEN
-  765                                                 aKind := 2
-  766                                               ELSE at := SymTab.QualType(nm, nm2);
-  767                                                 IF at # SymTab.InvalidType THEN
-  768                                                   aKind := 0
-  769                                                 ELSE SemError(201);
-  770                                                   aKind := 0; at := SymTab.InvalidType
-  771                                                 END
-  772                                               END;
-  773                                               CopyNm(nm, amod);
-  774                                               CopyNm(nm2, nm)
-  775                                             ELSIF SymTab.Lookup(nm)
-  776                                                AND ((SymTab.SymKind(nm) = SymTab.KindType)
-  777                                                  OR (SymTab.SymKind(nm) = SymTab.KindPredef)) THEN
-  778                                                at := SymTab.SymType(nm)
-  779                                              ELSIF SymTab.Lookup(nm)
-  780                                                AND (SymTab.SymKind(nm) = SymTab.KindProc) THEN
-  781                                                aKind := 2; at := SymTab.SymType(nm);
-  782                                                IF NOT SymTab.SymMod(nm, amod) THEN
-  783                                                  amod[0] := CHR(0) END
-  784                                              ELSIF SymTab.Lookup(nm)
-  785                                                AND (SymTab.SymKind(nm) = SymTab.KindConst) THEN
-  786                                                isV := TRUE; aKind := 1; at := SymTab.SymType(nm);
-  787                                                IF NOT SymTab.GetSymVal(nm, s) THEN s[0] := CHR(0) END;
-  788                                                CopyNm(s, nm)
-  789                                              ELSE SemError(201)
-  790                                              END; .) )
-  791                                          (. IF refN <= HIGH(refActual) THEN
-  792                                               IF aKind = 0 THEN
-  793                                                 IF isV THEN refKind[refN] := 1
-  794                                                 ELSE refKind[refN] := 0 END
-  795                                               ELSE refKind[refN] := aKind END;
-  796                                               refActual[refN] := at;
-  797                                               k := 0;
-  798                                               WHILE (k <= HIGH(refVal[refN])) AND (nm[k] # CHR(0)) DO
-  799                                                 refVal[refN][k] := nm[k]; INC(k) END;
-  800                                               refVal[refN][k] := CHR(0);
-  801                                               k := 0;
-  802                                               WHILE (k <= HIGH(refMod[refN])) AND (amod[k] # CHR(0)) DO
-  803                                                 refMod[refN][k] := amod[k]; INC(k) END;
-  804                                               refMod[refN][k] := CHR(0);
-  805                                               INC(refN)
-  806                                             END; .) .
-  807    Unit
-  808      =                                   (. isGen := FALSE;
-  809                                             allowDefer := FALSE;
-  810                                             allowFwdType := FALSE;
-  811                                             repassing := FALSE; .)
-  812        [ "GENERIC"                       (. isGen := TRUE; .) ]
-  813        ( DefUnit | ImplUnit | ProgModule ) .
-  814    (* Step 4.3: one session compiles DEFINITION, its IMPLEMENTATION
-  815       and one program (last) into one image. Units share the symbol
-  816       table; imports materialize exported names. *)
-  817    DefUnit                               (. VAR m1, m2, pn: SymTab.Name;
-  818                                               g: SymTab.Name;
-  819                                               astSeq, astTail, astProc: AST.Node; .)
-  820      =                                   (. refN := 0; refSeen := FALSE; .)
-  821        "DEFINITION" "MODULE"
-  822        [ "FOR" string ]                  (* ISO foreign module: FOR "C" *)
-  823        GetIdent<m1>                      (. IF instActive THEN InstNameGet(m1) END;
-  824                                             IF instActive THEN
-  825                                               IF NOT SymTab.Reenter(m1,
-  826                                                      SymTab.UnitDef) THEN
-  827                                                 SemError(200) END
-  828                                             ELSIF NOT SymTab.BeginDef(m1) THEN
-  829                                               SemError(200) END;
-  830                                             QbeGen.SetModule(m1);
-  831                                             CopyNm(m1, unitName);
-  832                                             unitWasGen := isGen
-  833                                               AND NOT instActive;
-  834                                             unitWasDef := TRUE; .)
-  835        [ GenericFormals ]
-  836        ( ";"
-  837        { Import                        (. AstAppend(AST.NkDeclSeq,
-  838                                               astImp, astImpTail, astDecl); .) }
-  839        [ "EXPORT" [ "QUALIFIED" | "UNQUALIFIED" ]        (. (* definition-module export
-  840                                                list: parsed, and the
-  841                                                names are already exported
-  842                                                by the module scope *) .)
-  843          GetIdent<pn> { "," GetIdent<pn> } ";" ]
-  844                                          (. astSeq := AST.NoNode;
-  845                                             astTail := AST.NoNode; .)
-  846        { ConstBlock                      (. AstAppend(AST.NkDeclSeq,
-  847                                               astSeq, astTail, astDecl); .)
-  848        | TypeBlock<TRUE>                 (. AstAppend(AST.NkDeclSeq,
-  849                                               astSeq, astTail, astDecl); .)
-  850        | VarBlock                        (. AstAppend(AST.NkDeclSeq,
-  851                                               astSeq, astTail, astDecl); .)
-  852        | ProcHeading<pn, SymTab.InvalidType> ";"
-  853                                          (. (* a heading only: record it so
-  854                                                Lower can replay it *)
-  855                                             astProc := AST.MakeNode(AST.NkProcDecl);
-  856                                             AST.SetOp(astProc, 0);
-  857                                             AST.SetChild(astProc, 0,
-  858                                               AST.MakeLeaf(AST.NkIdent, pn));
-  859                                             AstAppend(AST.NkDeclSeq,
-  860                                               astSeq, astTail, astProc);
-  861                                             Lower.NoteProcNode(astProc);
-  862                                             Lower.ScopeLeave;
-  863                                             SymTab.CloseProc;
-  864                                             QbeGen.AbortFunc; .) }
-  865                                          (. astUnit := AST.MakeNode(AST.NkUnit);
-  866                                             AST.SetChild(astUnit, 0,
-  867                                               AST.MakeLeaf(AST.NkIdent, m1));
-  868                                             AST.SetChild(astUnit, 1, astSeq);
-  869                                             AST.SetChild(astUnit, 3, astImp);
-  870                                             astDecl := AST.NoNode;
-  871                                             astStmt := AST.NoNode; .)
-  872        "END"
-  873        GetIdent<m2>                      (. IF instActive THEN InstNameGet(m2) END;
-  874                                             IF NOT SymTab.Equal(m1, m2) THEN
-  875                                               SemError(202) END;
-  876                                             SymTab.EndUnit; .)
-  877        | "=" GetIdent<g> [ "(" Actuals ")" ] ";"
-  878                                          (. CopyNm(m1, refInst);
-  879                                             CopyNm(g, refGen);
-  880                                             refSeen := TRUE; refIsDef := TRUE;
-  881                                             astUnit := AST.MakeNode(AST.NkUnit);
+  638  COMMENTS FROM "(*" TO "*)" NESTED
+  639  COMMENTS FROM "//" TO lf
+  640  
+  641  TOKENS
+  642    ident   = ( letter | "_" ) { letter | digit | "_" } .
+  643    integer = digit { digit }
+  644            | digit { digit } CONTEXT("..")
+  645            | "0x" hexDigit { hexDigit }
+  646            | "0X" hexDigit { hexDigit } .
+  647    real    = digit { digit } "." { digit }
+  648              [ ( "E" | "e" ) [ "+" | "-" ] digit { digit } ] .
+  649    string  = "'" { noQuote1 } "'"
+  650            | '"' { noQuote2 } '"' .
+  651    charConst = digit { digit } ( "C" | "c" ) .
+  652    ustring = ( "U" | "u" ) ( "'" { noQuote1 } "'" | '"' { noQuote2 } '"' ) .
+  653  
+  654  PRODUCTIONS
+  655    M2
+  656      = (. astCur := AST.NoNode; astStmt := AST.NoNode; astDecl := AST.NoNode; astImp := AST.NoNode; astImpTail := AST.NoNode;
+  657                                             astImp := AST.NoNode;
+  658                                             astImpTail := AST.NoNode;
+  659                                             nSpans := 0;
+  660                                             SymTab.DeferReset; .)
+  661        Unit "."                          (. IF SymTab.TypesOverflow() THEN
+  662                                               SemError(230)  (* MaxTypes *)
+  663                                             END; .) .
+  664    (* Units: program modules compile fully; DEFINITION and
+  665       IMPLEMENTATION modules parse + check now but lower in step 4
+  666       (each ends with one 230); same for nested local modules. *)
+  667    (* Generics (Increment 1): formal and actual parameters.  Formals are
+  668       TYPE parameters only; actuals are type identifiers. *)
+  669    GenericFormals
+  670      = "(" GenericFormal { ";" GenericFormal } ")" .
+  671    GenericFormal                         (. VAR nm: SymTab.Name; vt: SymTab.TypeIndex;
+  672                                               names: ARRAY [0 .. 15] OF SymTab.Name;
+  673                                               nn, k: CARDINAL;
+  674                                               mmod: SymTab.Name;
+  675                                               quid, qdep: CARDINAL;
+  676                                               qres: SymTab.TypeIndex;
+  677                                               qext: BOOLEAN;
+  678                                               cons: INTEGER;
+  679                                               cn: SymTab.Name;
+  680                                               isTypeFormal: BOOLEAN; .)
+  681      =                                   (. nn := 0; .)
+  682        GetIdent<nm>                      (. k := 0;
+  683                                             WHILE (k <= HIGH(names[nn])) AND (nm[k] # CHR(0)) DO
+  684                                               names[nn][k] := nm[k]; INC(k) END;
+  685                                             names[nn][k] := CHR(0); INC(nn); .)
+  686        { "," GetIdent<nm>                (. k := 0;
+  687                                             WHILE (k <= HIGH(names[nn])) AND (nm[k] # CHR(0)) DO
+  688                                               names[nn][k] := nm[k]; INC(k) END;
+  689                                             names[nn][k] := CHR(0); INC(nn); .) }
+  690        ":"                               (. vt := SymTab.InvalidType; isTypeFormal := FALSE; .)
+  691        ( "TYPE"                          (. isTypeFormal := TRUE; .)
+  692          [ "(" GetIdent<cn> ")"          (. cons := ConsCode(cn); .) ]
+  693        | ProcType<vt>                    (. isTypeFormal := FALSE; .)
+  694        | TypeIdent<vt> )                 (. k := 0;
+  695                                             WHILE k < nn DO
+  696                                               IF isTypeFormal THEN
+  697                                                 IF instActive THEN
+  698                                                   (* constraint: a type
+  699                                                      formal needs a type
+  700                                                      actual that satisfies
+  701                                                      the declared constraint *)
+  702                                                   IF InstActualKind(instFk) # 0 THEN
+  703                                                     SemError(233)
+  704                                                   ELSIF NOT ConsOk(cons, InstActualGet(instFk)) THEN
+  705                                                     SemError(233)
+  706                                                   ELSIF NOT SymTab.EnterTypeParamBound(names[k], InstActualGet(instFk)) THEN
+  707                                                     SemError(200) END
+  708                                                 ELSIF NOT SymTab.EnterTypeParam(names[k]) THEN
+  709                                                   SemError(200) END
+  710                                               ELSIF SymTab.ClassOf(vt) = SymTab.ClProc THEN
+  711                                                 (* procedure formal *)
+  712                                                 IF instActive THEN
+  713                                                   IF InstActualKind(instFk) # 2 THEN
+  714                                                     SemError(233) END;
+  715                                                   InstActualMod(instFk, mmod);
+  716                                                   InstActualVal(instFk, nm);
+  717                                                   IF NOT SymTab.AliasProc(names[k], mmod, nm) THEN
+  718                                                     SemError(201)
+  719                                                   ELSIF SymTab.QualProcInfo(mmod, nm, quid, qdep, qres, qext) THEN
+  720                                                     Lower.AliasProc(names[k], quid, qres, qdep, qext)
+  721                                                   END
+  722                                                 ELSE
+  723                                                   (* template: a callable
+  724                                                      placeholder of the
+  725                                                      formal's proc type *)
+  726                                                   IF NOT SymTab.Enter(names[k], SymTab.KindVar) THEN
+  727                                                     SemError(200) END;
+  728                                                   SymTab.SetSymType(names[k], vt)
+  729                                                 END
+  730                                               ELSE
+  731                                                 (* constraint: a value
+  732                                                    formal needs a value
+  733                                                    actual *)
+  734                                                 IF instActive AND (InstActualKind(instFk) # 1) THEN
+  735                                                   SemError(233) END;
+  736                                                 IF NOT SymTab.Enter(names[k], SymTab.KindConst) THEN
+  737                                                   SemError(200) END;
+  738                                                 SymTab.SetSymType(names[k], vt);
+  739                                                 IF instActive THEN
+  740                                                   InstActualVal(instFk, nm);
+  741                                                   SymTab.SetSymVal(names[k], nm)
+  742                                                 ELSE SymTab.SetSymVal(names[k], "0")
+  743                                                 END
+  744                                               END;
+  745                                               INC(instFk); INC(k)
+  746                                             END; .) .
+  747    Actuals
+  748      = Actual { "," Actual } .
+  749    Actual                                (. VAR at: SymTab.TypeIndex;
+  750                                               nm: SymTab.Name;
+  751                                               s: ARRAY [0 .. 255] OF CHAR;
+  752                                               qv: QbeGen.QVal;
+  753                                               isCh, isV: BOOLEAN;
+  754                                               aKind: INTEGER;
+  755                                               amod: SymTab.Name;
+  756                                               nm2: SymTab.Name;
+  757                                               qu, qd: CARDINAL;
+  758                                               qr: SymTab.TypeIndex;
+  759                                               qe: BOOLEAN;
+  760                                               k: CARDINAL; .)
+  761      =                                   (. isV := FALSE; at := SymTab.InvalidType;
+  762                                             nm[0] := CHR(0); nm2[0] := CHR(0);
+  763                                             aKind := 0; amod[0] := CHR(0); .)
+  764        ( integer                         (. LexString(s); QbeGen.NormInt(s, qv);
+  765                                             isV := TRUE; aKind := 1; at := SymTab.IntType();
+  766                                             CopyNm(qv, nm); .)
+  767        | charConst                       (. LexString(s); QbeGen.NormLit(s, qv, isCh);
+  768                                             isV := TRUE; aKind := 1; at := SymTab.CharType();
+  769                                             CopyNm(qv, nm); .)
+  770        | GetIdent<nm> [ "." GetIdent<nm2> ]
+  771                                          (. isV := FALSE; at := SymTab.InvalidType;
+  772                                             aKind := 0; amod[0] := CHR(0);
+  773                                             IF nm2[0] # CHR(0) THEN
+  774                                               (* qualified actual Mod.Name:
+  775                                                  a nested instance's type
+  776                                                  (Mod.Type) or a procedure
+  777                                                  (Mod.Proc); no import
+  778                                                  needed *)
+  779                                               IF SymTab.QualProcInfo(nm, nm2,
+  780                                                    qu, qd, qr, qe) THEN
+  781                                                 aKind := 2
+  782                                               ELSE at := SymTab.QualType(nm, nm2);
+  783                                                 IF at # SymTab.InvalidType THEN
+  784                                                   aKind := 0
+  785                                                 ELSE SemError(201);
+  786                                                   aKind := 0; at := SymTab.InvalidType
+  787                                                 END
+  788                                               END;
+  789                                               CopyNm(nm, amod);
+  790                                               CopyNm(nm2, nm)
+  791                                             ELSIF SymTab.Lookup(nm)
+  792                                                AND ((SymTab.SymKind(nm) = SymTab.KindType)
+  793                                                  OR (SymTab.SymKind(nm) = SymTab.KindPredef)) THEN
+  794                                                at := SymTab.SymType(nm)
+  795                                              ELSIF SymTab.Lookup(nm)
+  796                                                AND (SymTab.SymKind(nm) = SymTab.KindProc) THEN
+  797                                                aKind := 2; at := SymTab.SymType(nm);
+  798                                                IF NOT SymTab.SymMod(nm, amod) THEN
+  799                                                  amod[0] := CHR(0) END
+  800                                              ELSIF SymTab.Lookup(nm)
+  801                                                AND (SymTab.SymKind(nm) = SymTab.KindConst) THEN
+  802                                                isV := TRUE; aKind := 1; at := SymTab.SymType(nm);
+  803                                                IF NOT SymTab.GetSymVal(nm, s) THEN s[0] := CHR(0) END;
+  804                                                CopyNm(s, nm)
+  805                                              ELSE SemError(201)
+  806                                              END; .) )
+  807                                          (. IF refN <= HIGH(refActual) THEN
+  808                                               IF aKind = 0 THEN
+  809                                                 IF isV THEN refKind[refN] := 1
+  810                                                 ELSE refKind[refN] := 0 END
+  811                                               ELSE refKind[refN] := aKind END;
+  812                                               refActual[refN] := at;
+  813                                               k := 0;
+  814                                               WHILE (k <= HIGH(refVal[refN])) AND (nm[k] # CHR(0)) DO
+  815                                                 refVal[refN][k] := nm[k]; INC(k) END;
+  816                                               refVal[refN][k] := CHR(0);
+  817                                               k := 0;
+  818                                               WHILE (k <= HIGH(refMod[refN])) AND (amod[k] # CHR(0)) DO
+  819                                                 refMod[refN][k] := amod[k]; INC(k) END;
+  820                                               refMod[refN][k] := CHR(0);
+  821                                               INC(refN)
+  822                                             END; .) .
+  823    Unit
+  824      =                                   (. isGen := FALSE;
+  825                                             allowDefer := FALSE;
+  826                                             allowFwdType := FALSE;
+  827                                             repassing := FALSE; .)
+  828        [ "GENERIC"                       (. isGen := TRUE; .) ]
+  829        ( DefUnit | ImplUnit | ProgModule ) .
+  830    (* Step 4.3: one session compiles DEFINITION, its IMPLEMENTATION
+  831       and one program (last) into one image. Units share the symbol
+  832       table; imports materialize exported names. *)
+  833    DefUnit                               (. VAR m1, m2, pn: SymTab.Name;
+  834                                               g: SymTab.Name;
+  835                                               astSeq, astTail, astProc: AST.Node; .)
+  836      =                                   (. refN := 0; refSeen := FALSE; .)
+  837        "DEFINITION" "MODULE"
+  838        [ "FOR" string ]                  (* ISO foreign module: FOR "C" *)
+  839        GetIdent<m1>                      (. IF instActive THEN InstNameGet(m1) END;
+  840                                             IF instActive THEN
+  841                                               IF NOT SymTab.Reenter(m1,
+  842                                                      SymTab.UnitDef) THEN
+  843                                                 SemError(200) END
+  844                                             ELSIF NOT SymTab.BeginDef(m1) THEN
+  845                                               SemError(200) END;
+  846                                             QbeGen.SetModule(m1);
+  847                                             CopyNm(m1, unitName);
+  848                                             unitWasGen := isGen
+  849                                               AND NOT instActive;
+  850                                             unitWasDef := TRUE; .)
+  851        [ GenericFormals ]
+  852        ( ";"
+  853        { Import                        (. AstAppend(AST.NkDeclSeq,
+  854                                               astImp, astImpTail, astDecl); .) }
+  855        [ "EXPORT" [ "QUALIFIED" | "UNQUALIFIED" ]        (. (* definition-module export
+  856                                                list: parsed, and the
+  857                                                names are already exported
+  858                                                by the module scope *) .)
+  859          GetIdent<pn> { "," GetIdent<pn> } ";" ]
+  860                                          (. astSeq := AST.NoNode;
+  861                                             astTail := AST.NoNode; .)
+  862        { ConstBlock                      (. AstAppend(AST.NkDeclSeq,
+  863                                               astSeq, astTail, astDecl); .)
+  864        | TypeBlock<TRUE>                 (. AstAppend(AST.NkDeclSeq,
+  865                                               astSeq, astTail, astDecl); .)
+  866        | VarBlock                        (. AstAppend(AST.NkDeclSeq,
+  867                                               astSeq, astTail, astDecl); .)
+  868        | ProcHeading<pn, SymTab.InvalidType> ";"
+  869                                          (. (* a heading only: record it so
+  870                                                Lower can replay it *)
+  871                                             astProc := AST.MakeNode(AST.NkProcDecl);
+  872                                             AST.SetOp(astProc, 0);
+  873                                             AST.SetChild(astProc, 0,
+  874                                               AST.MakeLeaf(AST.NkIdent, pn));
+  875                                             AstAppend(AST.NkDeclSeq,
+  876                                               astSeq, astTail, astProc);
+  877                                             Lower.NoteProcNode(astProc);
+  878                                             Lower.ScopeLeave;
+  879                                             SymTab.CloseProc;
+  880                                             QbeGen.AbortFunc; .) }
+  881                                          (. astUnit := AST.MakeNode(AST.NkUnit);
   882                                             AST.SetChild(astUnit, 0,
   883                                               AST.MakeLeaf(AST.NkIdent, m1));
-  884                                             astDecl := AST.NoNode;
-  885                                             astStmt := AST.NoNode; .)
-  886          "END"
-  887          GetIdent<m2>                    (. IF NOT SymTab.Equal(m1, m2) THEN
-  888                                               SemError(202) END;
-  889                                             SymTab.EndUnit; .) ) .
-  890    ImplUnit                              (. VAR m1, m2: SymTab.Name;
-  891                                               g: SymTab.Name;
-  892                                               k: CARDINAL;
-  893                                               rp: CARDINAL;
-  894                                               rpOk: BOOLEAN;
-  895                                               rErrs: INTEGER;
-  896                                               rDecl, rStmt: AST.Node;
-  897                                               rnm: SymTab.Name;
-  898                                               rSym, rErr: CARDINAL;
-  899                                               fname: SymTab.Name;
-  900                                               unres: BOOLEAN;
-  901                                               astNode: AST.Node; .)
-  902      =                                   (. refN := 0; refSeen := FALSE; .)
-  903        "IMPLEMENTATION" "MODULE"
-  904        [ "FOR" string ]                  (* ISO foreign module: FOR "C" *)
-  905        GetIdent<m1> (. IF instActive THEN InstNameGet(m1) END;
-  906                       IF instActive THEN
-  907                         IF NOT SymTab.Reenter(m1,
-  908                                SymTab.UnitImpl) THEN
-  909                           SemError(201) END
-  910                       ELSIF NOT SymTab.BeginImpl(m1) THEN
-  911                         SemError(201) END;
-  912                       astStmt := AST.NoNode;
-  913                       astDecl := AST.NoNode;
-  914                       astImp := AST.NoNode;
-  915                       astImpTail := AST.NoNode;
-  916                       nPendVar := 0;
-  917                       CopyNm(m1, unitName);
-  918                       unitWasGen := isGen AND NOT instActive;
-  919                       unitWasDef := FALSE;
-  920                       QbeGen.SetModule(m1); .)
-  921        [ GenericFormals ]
-  922        ( ";"
-  923        { Import                        (. AstAppend(AST.NkDeclSeq,
-  924                                               astImp, astImpTail, astDecl); .) }
-  925        DeclSeq                           (. astStmt := AST.NoNode; .)
-  926        [ "BEGIN"                         (. FlushPend;
-  927                                             k := 0;
-  928                                             WHILE k < SymTab.FwdPending() DO
-  929                                               SymTab.FwdInfo(k, fname, unres);
-  930                                               IF unres THEN SemError(201) END;
-  931                                               INC(k)
-  932                                             END;
-  933                                             SymTab.FwdClear;
-  934  
-  935                                             nLab := 0; nGot := 0; .)
-  936          [ StatSeq ] ]
-  937                                          (. IF twoPhaseParse THEN
-  938                                               rSym := sym; rErr := errDist;
-  939                                               rDecl := astDecl; rStmt := astStmt;
-  940                                               M2S.PushPos;
-  941                                               repassing := TRUE;
-  942                                               rp := 0;
-  943                                               WHILE rp < nSpans DO
-  944                                                 k := 0;
-  945                                                 WHILE (k <= HIGH(rnm))
-  946                                                   AND (spanName[rp][k] # CHR(0)) DO
-  947                                                   rnm[k] := spanName[rp][k]; INC(k)
-  948                                                 END;
-  949                                                 rnm[k] := CHR(0);
-  950                                                 M2S.SeekTo(spanStart[rp]);
-  951                                                 Adv;
-  952                                                 rpOk := SymTab.ReenterDeferred(spanIdx[rp]);
-  953                                                 IF NOT rpOk THEN
-  954                                                   FileIO.WriteString(FileIO.StdOut,
-  955                                                     "twophase reenter failed");
-  956                                                   FileIO.WriteLn(FileIO.StdOut)
-  957                                                 END;
-  958                                                 Lower.ReenterScopeProc(spanTy[rp]);
-  959                                                 QbeGen.BeginFunc("");
-  960                                                 CopyNm(rnm, curFun);
-  961                                                 Block(rnm);
-  962                                                 AST.SetChild(spanNode[rp], 1, astStmt);
-  963                                                 AST.SetChild(spanNode[rp], 2, astBlkDecls);
-  964                                                 Lower.ScopeLeave;
-  965                                                 SymTab.CloseProc;
-  966                                                 QbeGen.EndFunc(SymTab.ProcRes(rnm));
-  967                                                 INC(rp)
-  968                                               END;
-  969                                               curFun[0] := CHR(0);
-  970                                               SymTab.OrderCheckOff; rErrs := M2S.errors;
-  971                                               repassing := FALSE;
-  972                                               M2S.PopPos;
-  973                                               sym := rSym; errDist := rErr;
-  974                                               M2S.errors := rErrs;
-  975  
-  976                                               astDecl := rDecl; astStmt := rStmt
-  977                                             END; .)
-  978        "END"
-  979        GetIdent<m2>                      (. IF instActive THEN InstNameGet(m2) END;
-  980                                             FlushPend;
-  981                                             k := 0;
-  982                                             WHILE k < SymTab.FwdPending() DO
-  983                                               SymTab.FwdInfo(k, fname, unres);
-  984                                               IF unres THEN SemError(201) END;
-  985                                               INC(k)
-  986                                             END;
-  987                                             SymTab.FwdClear;
-  988  
-  989                                             astNode := AST.MakeNode(AST.NkUnit);
-  990                                             AST.SetChild(astNode, 0,
-  991                                               AST.MakeLeaf(AST.NkIdent, m1));
-  992                                             AST.SetChild(astNode, 1, astDecl);
-  993                                             AST.SetChild(astNode, 2, astStmt);
-  994                                             AST.SetChild(astNode, 3, astImp);
-  995                                             astUnit := astNode;
-  996                                             IF NOT SymTab.Equal(m1, m2) THEN
-  997                                               SemError(202) END;
-  998                                             CheckGotos;
-  999                                             SymTab.EndUnit; .)
- 1000        | "=" GetIdent<g> [ "(" Actuals ")" ] ";"
- 1001                                          (. CopyNm(m1, refInst);
- 1002                                             CopyNm(g, refGen);
- 1003                                             refSeen := TRUE; refIsDef := FALSE;
- 1004                                             astNode := AST.MakeNode(AST.NkUnit);
- 1005                                             AST.SetChild(astNode, 0,
- 1006                                               AST.MakeLeaf(AST.NkIdent, m1));
- 1007                                             astDecl := AST.NoNode;
- 1008                                             astStmt := AST.NoNode; .)
- 1009          { Import                        (. (* refinement unit import *) .) }
- 1010          "END"
- 1011          GetIdent<m2>                    (. IF NOT SymTab.Equal(m1, m2) THEN
- 1012                                               SemError(202) END;
- 1013                                             SymTab.EndUnit; .) ) .
- 1014    ProgModule                            (. VAR m1, m2: SymTab.Name;
- 1015                                               k: CARDINAL;
- 1016                                               rp: CARDINAL;
- 1017                                               rpOk: BOOLEAN;
- 1018                                               rErrs: INTEGER;
- 1019                                               rDecl, rStmt: AST.Node;
- 1020                                               rnm: SymTab.Name;
- 1021                                               rSym, rErr: CARDINAL;
- 1022                                               fname: SymTab.Name;
- 1023                                               unres: BOOLEAN;
- 1024                                               astNode: AST.Node; .)
- 1025      = "MODULE"
- 1026        GetIdent<m1> (. IF NOT SymTab.BeginProg(m1) THEN
- 1027                                               SemError(200) END;
- 1028                                             astStmt := AST.NoNode;
- 1029                                             astDecl := AST.NoNode;
- 1030                                             astImp := AST.NoNode;
- 1031                                             astImpTail := AST.NoNode;
- 1032                                             nPendVar := 0;
- 1033                                             QbeGen.SetModule(m1);
- 1034                                             CopyNm(m1, unitName); .)
- 1035        [ Priority ]
- 1036        ";"
- 1037        { Import                        (. AstAppend(AST.NkDeclSeq,
- 1038                                               astImp, astImpTail, astDecl); .) }
- 1039        DeclSeq                           (. astStmt := AST.NoNode; .)
- 1040        [ "BEGIN"                         (. FlushPend;
- 1041                                             k := 0;
- 1042                                             WHILE k < SymTab.FwdPending() DO
- 1043                                               SymTab.FwdInfo(k, fname, unres);
- 1044                                               IF unres THEN SemError(201) END;
- 1045                                               INC(k)
- 1046                                             END;
- 1047                                             SymTab.FwdClear;
- 1048  
- 1049                                             nLab := 0; nGot := 0; .)
- 1050          [ StatSeq ] ]
- 1051                                          (. IF twoPhaseParse THEN
- 1052                                               rSym := sym; rErr := errDist;
- 1053                                               rDecl := astDecl; rStmt := astStmt;
- 1054                                               M2S.PushPos;
- 1055                                               repassing := TRUE;
- 1056                                               rp := 0;
- 1057                                               WHILE rp < nSpans DO
- 1058                                                 k := 0;
- 1059                                                 WHILE (k <= HIGH(rnm))
- 1060                                                   AND (spanName[rp][k] # CHR(0)) DO
- 1061                                                   rnm[k] := spanName[rp][k]; INC(k)
- 1062                                                 END;
- 1063                                                 rnm[k] := CHR(0);
- 1064                                                 M2S.SeekTo(spanStart[rp]);
- 1065                                                 Adv;
- 1066                                                 rpOk := SymTab.ReenterDeferred(spanIdx[rp]);
- 1067                                                 IF NOT rpOk THEN
- 1068                                                   FileIO.WriteString(FileIO.StdOut,
- 1069                                                     "twophase reenter failed");
- 1070                                                   FileIO.WriteLn(FileIO.StdOut)
- 1071                                                 END;
- 1072                                                 Lower.ReenterScopeProc(spanTy[rp]);
- 1073                                                 QbeGen.BeginFunc("");
- 1074                                                 CopyNm(rnm, curFun);
- 1075                                                 Block(rnm);
- 1076                                                 AST.SetChild(spanNode[rp], 1, astStmt);
- 1077                                                 AST.SetChild(spanNode[rp], 2, astBlkDecls);
- 1078                                                 Lower.ScopeLeave;
- 1079                                                 SymTab.CloseProc;
- 1080                                                 QbeGen.EndFunc(SymTab.ProcRes(rnm));
- 1081                                                 INC(rp)
- 1082                                               END;
- 1083                                               curFun[0] := CHR(0);
- 1084                                               SymTab.OrderCheckOff; rErrs := M2S.errors;
- 1085                                               repassing := FALSE;
- 1086                                               M2S.PopPos;
- 1087                                               sym := rSym; errDist := rErr;
- 1088                                               M2S.errors := rErrs;
- 1089  
- 1090                                               astDecl := rDecl; astStmt := rStmt
- 1091                                             END; .)
- 1092        "END"
- 1093        GetIdent<m2>                      (. IF instActive THEN InstNameGet(m2) END;
- 1094                                             FlushPend;
- 1095                                             k := 0;
- 1096                                             WHILE k < SymTab.FwdPending() DO
- 1097                                               SymTab.FwdInfo(k, fname, unres);
- 1098                                               IF unres THEN SemError(201) END;
- 1099                                               INC(k)
- 1100                                             END;
- 1101                                             SymTab.FwdClear;
- 1102  
- 1103                                             IF NOT SymTab.Equal(m1, m2) THEN
- 1104                                               SemError(202) END;
- 1105                                             astNode := AST.MakeNode(AST.NkUnit);
- 1106                                             AST.SetChild(astNode, 0,
- 1107                                               AST.MakeLeaf(AST.NkIdent, m1));
- 1108                                             AST.SetChild(astNode, 1, astDecl);
- 1109                                             AST.SetChild(astNode, 2, astStmt);
- 1110                                             AST.SetChild(astNode, 3, astImp);
- 1111                                             astUnit := astNode;
- 1112                                             CheckGotos;
- 1113                                             SymTab.EndUnit; .) .
- 1114    DeclSeq                               (. VAR astSeq, astTail: AST.Node; .)
- 1115      =                                   (. astSeq := AST.NoNode;
- 1116                                             astTail := AST.NoNode; .)
- 1117        { (. astDecl := AST.NoNode; .)
- 1118          ( ConstBlock | TypeBlock<FALSE> | VarBlock | ProcDecl ";"
- 1119          | NestedModule ";" | ClassItem ";" )
- 1120                                          (. AstAppend(AST.NkDeclSeq,
- 1121                                               astSeq, astTail, astDecl); .) }
- 1122                                          (. astDecl := astSeq; .) .
- 1123    (* Local module, Wirth form. Declarations lower like top-level ones
- 1124       (same QBE module prefix); a BEGIN body becomes an init function
- 1125       that main calls; the EXPORT list is hoisted into the enclosing
- 1126       scope at END. *)
- 1127    NestedModule                          (. VAR m1, m2: SymTab.Name;
- 1128                                               expNames: ARRAY [0 .. 63] OF SymTab.Name;
- 1129                                               expCount, k: CARDINAL;
- 1130                                               astNode, nImp, nImpTail:
- 1131                                                 AST.Node; .)
- 1132      = "MODULE"
- 1133        GetIdent<m1>                      (. IF NOT SymTab.Enter(m1,
- 1134                                               SymTab.KindModule) THEN
- 1135                                               SemError(200) END;
- 1136                                             SymTab.PushScope;
- 1137                                             expCount := 0;
- 1138                                             astNode := AST.MakeNode(AST.NkUnit);
- 1139                                             AST.SetChild(astNode, 0,
- 1140                                               AST.MakeLeaf(AST.NkIdent, m1));
- 1141                                             astStmt := AST.NoNode;
- 1142                                             astDecl := AST.NoNode;
- 1143                                             nImp := AST.NoNode;
- 1144                                             nImpTail := AST.NoNode; .)
- 1145        [ Priority ]
- 1146        ";"
- 1147        { Import                        (. AstAppend(AST.NkDeclSeq,
- 1148                                               nImp, nImpTail, astDecl); .) }
- 1149        [ "EXPORT" [ "QUALIFIED" | "UNQUALIFIED" ]
- 1150          GetIdent<expNames[expCount]>    (. INC(expCount); .)
- 1151          { "," GetIdent<expNames[expCount]>
- 1152                                          (. INC(expCount); .) }
- 1153          ";" ]
- 1154        DeclSeq                           (. astStmt := AST.NoNode; .)
- 1155        [ "BEGIN"                         (. astStmt := AST.NoNode;
- 1156                                             .)
- 1157          [ StatSeq ] ]
- 1158        "END"
- 1159        GetIdent<m2>                      (. AST.SetChild(astNode, 1, astDecl);
- 1160                                             AST.SetChild(astNode, 2, astStmt);
- 1161                                             AST.SetChild(astNode, 3, nImp);
- 1162                                             astDecl := astNode;
- 1163                                             IF NOT SymTab.Equal(m1, m2) THEN
- 1164                                               SemError(202) END;
- 1165                                             k := 0;
- 1166                                             WHILE k < expCount DO
- 1167                                               SymTab.ExportUp(expNames[k]);
- 1168                                               INC(k)
- 1169                                             END;
- 1170                                             SymTab.PopScope; .) .
- 1171    Priority
- 1172      = "[" integer "]"                   (. SemError(230); .) .
- 1173    (* Imports (4.3): FROM materializes the names (unqualified use);
- 1174       plain IMPORT only demands the module exists — qualified `L.x`
- 1175       materializes on first use (Design). *)
- 1176    (* Unknown modules stay unchecked stubs (legacy, so hand-written
- 1177       import lines don't fail); a known module's missing export is
- 1178       201. *)
- 1179    Import                                (. VAR n: SymTab.Name;
- 1180                                               astImport: AST.Node; .)
- 1181      = "FROM"
- 1182        GetIdent<n>                       (. astImport := AST.MakeNode(AST.NkImport);
- 1183                                             AST.SetChild(astImport, 0,
- 1184                                               AST.MakeLeaf(AST.NkIdent, n)); .)
- 1185        "IMPORT"
- 1186        ImpList<n, astImport> ";"         (. astDecl := astImport; .)
- 1187      | "IMPORT"                          (. astImport := AST.MakeNode(AST.NkImport); .)
- 1188        ImpModList<astImport> ";"         (. astDecl := astImport; .) .
- 1189    ImpList<mod: SymTab.Name; node: AST.Node>
- 1190                                          (. VAR n: SymTab.Name; .)
- 1191      = ImpName<mod, node>
- 1192        { "," ImpName<mod, node> } .
- 1193    (* Pervasive built-ins imported from SYSTEM (e.g. TSIZE) are
- 1194       accepted and ignored: the built-in applies regardless. *)
- 1195    ImpName<mod: SymTab.Name; node: AST.Node>
- 1196                                          (. VAR n: SymTab.Name; .)
- 1197      = GetIdent<n> (. AST.SetChild(node, AST.NChild(node),
- 1198                                               AST.MakeLeaf(AST.NkIdent, n));
- 1199                                             IF SymTab.Equal(mod, "libc") THEN
- 1200                                               (* intrinsic C library:
- 1201                                                  permissive external *)
- 1202                                               IF NOT SymTab.DeclareCProc(n) THEN
- 1203                                                 SemError(201) END;
- 1204                                               Lower.NoteCProc(n)
- 1205                                             ELSIF SymTab.ModKnown(mod)
- 1206                                                AND NOT SymTab.Equal(mod,
- 1207                                                  "SYSTEM") THEN
- 1208                                               IF NOT SymTab.ImportFrom(mod, n) THEN
- 1209                                                 SemError(201)
- 1210                                               ELSE Lower.NoteImportedProc(n)
- 1211                                               END
- 1212                                             END; .)
- 1213      | ( "TSIZE" | "SIZE" | "ADR" | "HIGH" | "LEN"
- 1214        | "CHR" | "ORD" | "VAL" | "ABS" | "CAP"
- 1215        | "ODD" | "TRUNC" | "FLOAT"
- 1216        | "UCHR" | "CHR8" | "UORD"
- 1217        | "INC" | "DEC"
- 1218        | "SHIFT" | "ROTATE" | "CAST" | "CONVERT" | "MIN" | "MAX"
- 1219        | "INCL" | "EXCL" | "NEW" | "DISPOSE" | "LOC" ) .
- 1220    ImpModList<node: AST.Node>            (. VAR n: SymTab.Name; .)
- 1221      = GetIdent<n>                       (. AST.SetChild(node, AST.NChild(node),
- 1222                                               AST.MakeLeaf(AST.NkIdent, n)); .)
- 1223        { "," GetIdent<n>                 (. AST.SetChild(node, AST.NChild(node),
- 1224                                               AST.MakeLeaf(AST.NkIdent, n)); .) } .
- 1225    (* Opaque TYPE declarations (definition modules). The targetless
- 1226       alias resolves to InvalidType until step 4 completes it. *)
- 1227    (* Scalar-phase TYPEs: named types, integer subranges, enumerations.
- 1228       Opaque "TYPE T;" needs isDef (definition units); elsewhere 231.
- 1229       Composite forms (ARRAY/RECORD/SET/POINTER) arrive with step 3. *)
- 1230    TypeBlock<isDef: BOOLEAN>             (. VAR astSeq, astTail: AST.Node; .)
- 1231      = "TYPE"                            (. SymTab.BeginTypeBlock;
- 1232                                             astSeq := AST.NoNode;
- 1233                                             astTail := AST.NoNode; .)
- 1234        { (. astDecl := AST.NoNode; .)
- 1235          ( TypeItem<isDef> ";" | ClassItem ";" )
- 1236                                          (. AstAppend(AST.NkDeclSeq,
- 1237                                               astSeq, astTail, astDecl); .) }
- 1238                                          (. SymTab.EndTypeBlock;
- 1239                                             astDecl := astSeq; .) .
- 1240    TypeItem<isDef: BOOLEAN>              (. VAR n: SymTab.Name;
- 1241                                               t, op: SymTab.TypeIndex;
- 1242                                               astNode: AST.Node; .)
- 1243      = GetIdent<n>                       (. op := SymTab.OpaqueBase(n);
- 1244                                             IF op = SymTab.InvalidType THEN
- 1245                                               IF NOT SymTab.Enter(n,
- 1246                                                  SymTab.KindType) THEN
- 1247                                                 SemError(200) END
- 1248                                             END; .)
- 1249        ( "=" Type<t, FALSE> (. astNode := AST.MakeNode(AST.NkTypeDecl);
- 1250                                               AST.SetChild(astNode, 0,
- 1251                                                 AST.MakeLeaf(AST.NkIdent, n));
- 1252                                               AST.SetTy(astNode, t);
- 1253                                               astDecl := astNode;
- 1254                                               IF op # SymTab.InvalidType THEN
- 1255                                               SymTab.SetTarget(op, t)
- 1256                                             ELSE SymTab.SetSymType(n, t)
- 1257                                             END;
- 1258                                             IF SymTab.EnterEnumLits(t) > 0 THEN END; .)
- 1259        |                                 (. IF op # SymTab.InvalidType THEN
- 1260                                               (* stays opaque *)
- 1261                                             ELSIF NOT isDef THEN
- 1262                                               SemError(231)
- 1263                                             ELSE SymTab.SetSymType(n,
- 1264                                               SymTab.NewAlias()) END; .) ) .
- 1265    Type<VAR t: SymTab.TypeIndex; allowOpen: BOOLEAN>
- 1266      = TypeIdent<t> [ Subrange<t> ]     (* anchored subrange: T[lo..hi] *)
- 1267      | Subrange<t>
- 1268      | Enum<t>
- 1269      | ArrayType<t, allowOpen>
- 1270      | SetType<t>
- 1271      | PackSetType<t>
- 1272      | RecordType<t>
- 1273      | PointerType<t>
- 1274      | ProcType<t> .
- 1275    PointerType<VAR t: SymTab.TypeIndex>  (. VAR base: SymTab.TypeIndex; .)
- 1276      = "POINTER" "TO"                    (. allowFwdType := TRUE; .)
- 1277        Type<base, FALSE>                 (. allowFwdType := FALSE;
- 1278                                             t := SymTab.NewPtr(base); .) .
- 1279    (* Procedure types (step 8.5): PROCEDURE (params): result. Values
- 1280       are code pointers; params are collected into the descriptor. *)
- 1281    ProcType<VAR t: SymTab.TypeIndex>     (. VAR res, pt: SymTab.TypeIndex;
- 1282                                               isV: BOOLEAN; .)
- 1283      = ( "PROCEDURE" | "PROC" )         (. allowFwdType := FALSE;
- 1284                                             res := SymTab.InvalidType;
- 1285                                             t := SymTab.NewProcType(res); .)
- 1286        [ "(" [ ProcTypeSection<t>
- 1287                 { (";" | ",") ProcTypeSection<t> } ] ")" ]
- 1288        [ ":" ( TypeIdent<res>            (. SymTab.SetProcTypeRes(t, res); .)
- 1289              | "PROC"                    (. (* PROC as a result type: the
- 1290                                                pervasive procedure value
- 1291                                                type (ISO/PIM) *)
- 1292                                             SymTab.SetProcTypeRes(t,
- 1293                                               SymTab.AddrType()); .) ) ] .
- 1294    ProcTypeSection<t: SymTab.TypeIndex>  (. VAR pt: SymTab.TypeIndex;
- 1295                                               isV: BOOLEAN;
- 1296                                               cnt, k: CARDINAL;
- 1297                                               names: ARRAY [0 .. 15] OF SymTab.Name; .)
- 1298      =                                   (. isV := FALSE; cnt := 0; .)
- 1299        [ "VAR"                           (. isV := TRUE; .) ]
- 1300        ( GetIdent<names[cnt]>            (. INC(cnt); .)
- 1301          { "," ( GetIdent<names[cnt]>    (. INC(cnt); .)
- 1302                |                         (. (* a comma followed by a type
- 1303                                                (possibly VAR) ends the name
- 1304                                                list: the collected names
- 1305                                                were types, not names *)
- 1306                                             k := 0;
- 1307                                             WHILE k < cnt DO
- 1308                                               SymTab.ProcTypeAdd(t, isV,
- 1309                                                 SymTab.SymType(names[k]));
- 1310                                               INC(k)
- 1311                                             END;
- 1312                                             cnt := 0; .)
- 1313                  [ "VAR"                 (. isV := TRUE; .) ]
- 1314                  Type<pt, TRUE>          (. SymTab.ProcTypeAdd(t, isV, pt); .) ) }
- 1315          ( ":" Type<pt, TRUE>            (. k := 0;
- 1316                                             WHILE k < cnt DO
- 1317                                               SymTab.ProcTypeAdd(t, isV, pt);
- 1318                                               INC(k)
- 1319                                             END; .)
- 1320          |                               (. (* type-only parameter list:
- 1321                                                each collected name is a
- 1322                                                type (CHAR, a declared type,
- 1323                                                ... or the GNU shorthand) *)
- 1324                                             k := 0;
- 1325                                             WHILE k < cnt DO
- 1326                                               IF IsTypeName(names[k]) THEN
- 1327                                                 pt := SymTab.SymType(names[k])
- 1328                                               ELSE SemError(201);
- 1329                                                 pt := SymTab.InvalidType
- 1330                                               END;
- 1331                                               SymTab.ProcTypeAdd(t, isV, pt);
- 1332                                               INC(k)
- 1333                                             END; .) )
- 1334        | Type<pt, TRUE>                 (. (* unnamed parameter (PIM):
- 1335                                                e.g. PROCEDURE (VAR ARRAY OF REAL) *)
- 1336                                             SymTab.ProcTypeAdd(t, isV, pt); .) ) .
- 1337    (* Arrays: "OF" without bounds is an open formal (allowed only
- 1338       where allowOpen); "[lo..hi, ...]" nests bounded levels inside
- 1339       out.  The PIM/ISO multi-index form repeats the bracket group
- 1340       ("ARRAY [lo..hi], [lo..hi] OF T"); the bounds of every group
- 1341       nest in the same inside-out order as the comma list.  Bounds are
- 1342       folded literals (int/char); anything else 230.  Bare-type indices
- 1343       ("ARRAY Color OF") wait for enum ordinals. *)
- 1344    ArrayType<VAR t: SymTab.TypeIndex; allowOpen: BOOLEAN>
- 1345                                          (. VAR elem: SymTab.TypeIndex;
- 1346                                               eb: SymTab.Name;
- 1347                                               ok: BOOLEAN;
- 1348                                               bnds, bndh: ARRAY [0 .. 7] OF INTEGER;
- 1349                                               nb, k: CARDINAL;
- 1350                                               idx: SymTab.TypeIndex;
- 1351                                               ilo, ihi: INTEGER; .)
- 1352      = "ARRAY"                           (. allowFwdType := FALSE; .)
- 1353        ( "OF"
- 1354          Type<elem, FALSE>               (. LexName(eb); (* the element ident *)
- 1355                                             IF NOT allowOpen THEN
- 1356                                               SemError(230) END;
- 1357                                             t := SymTab.NewOpenArray(elem);
- 1358                                             IF SymTab.Equal(eb, "BYTE") THEN
- 1359                                               SymTab.MarkByteBuf(t) END; .)
- 1360        | TypeIdent<idx> [ Subrange<idx> ]
- 1361          "OF" Type<elem, FALSE>          (. (* index-type array: the index
- 1362                                                type's ordinal bounds give the
- 1363                                                [lo..hi] pair *)
- 1364                                             IF SymTab.TypeBounds(idx, ilo,
- 1365                                                ihi)
- 1366                                             THEN t := SymTab.NewArrayB(elem,
- 1367                                                    ilo, ihi)
- 1368                                             ELSE SemError(230);
- 1369                                               t := SymTab.InvalidType
- 1370                                             END; .)
- 1371        | "["                             (. SymTab.BoundBegin; ok := TRUE;
- 1372                                             nb := 0; .)
- 1373          BoundPair<ok>
- 1374          { "," BoundPair<ok> }
- 1375          "]"                             (. (* snapshot this bracket group
- 1376                                                before the element type, which
- 1377                                                reuses the bound buffer for a
- 1378                                                nested ARRAY *)
- 1379                                             IF nb + SymTab.BoundCount() >
- 1380                                                HIGH(bnds) + 1 THEN
- 1381                                               SemError(230); ok := FALSE
- 1382                                             ELSE
- 1383                                               k := 0;
- 1384                                               WHILE k < SymTab.BoundCount() DO
- 1385                                                 bnds[nb] := SymTab.BoundLo(k);
- 1386                                                 bndh[nb] := SymTab.BoundHi(k);
- 1387                                                 INC(k); INC(nb)
- 1388                                               END
- 1389                                             END; .)
- 1390          { "," "["                       (. SymTab.BoundBegin; .)
- 1391            BoundPair<ok>
- 1392            { "," BoundPair<ok> }
- 1393            "]"                           (. IF nb + SymTab.BoundCount() >
- 1394                                                HIGH(bnds) + 1 THEN
- 1395                                               SemError(230); ok := FALSE
- 1396                                             ELSE
- 1397                                               k := 0;
- 1398                                               WHILE k < SymTab.BoundCount() DO
- 1399                                                 bnds[nb] := SymTab.BoundLo(k);
- 1400                                                 bndh[nb] := SymTab.BoundHi(k);
- 1401                                                 INC(k); INC(nb)
- 1402                                               END
- 1403                                             END; .) }
- 1404          "OF" Type<elem, FALSE>
- 1405                                          (. IF ok THEN
- 1406                                               k := nb;
- 1407                                               WHILE k > 0 DO
- 1408                                                 DEC(k);
- 1409                                                 elem := SymTab.NewArrayB(
- 1410                                                   elem, bnds[k], bndh[k])
- 1411                                               END;
- 1412                                               t := elem
- 1413                                             ELSE t := SymTab.InvalidType
- 1414                                             END; .) ) .
- 1415    BoundPair<VAR ok: BOOLEAN>            (. VAR tlo, thi: SymTab.TypeIndex;
- 1416                                               qlo, qhi: QbeGen.QVal;
- 1417                                               lo, hi: INTEGER;
- 1418                                               cl, cl2: INTEGER; .)
- 1419      = Expr<tlo, qlo> ".." Expr<thi, qhi>
- 1420                                          (. IF (tlo = SymTab.InvalidType)
- 1421                                              OR (thi = SymTab.InvalidType) THEN
- 1422                                             ok := FALSE
- 1423                                           ELSE cl := SymTab.ClassOf(tlo);
- 1424                                             cl2 := SymTab.ClassOf(thi);
- 1425                                             IF ((cl # SymTab.ClInt)
- 1426   AND (cl # SymTab.ClChar)
- 1427   AND (cl # SymTab.ClBool)
- 1428   AND (cl # SymTab.ClEnum)
- 1429   AND (cl # SymTab.ClByte)
- 1430   AND (cl # SymTab.ClSByte)
- 1431   AND (cl # SymTab.ClWord16)
- 1432   AND (cl # SymTab.ClSWord16))
- 1433                                                OR ((cl2 # SymTab.ClInt)
- 1434   AND (cl2 # SymTab.ClChar)
- 1435   AND (cl2 # SymTab.ClBool)
- 1436   AND (cl2 # SymTab.ClEnum)
- 1437   AND (cl2 # SymTab.ClByte)
- 1438   AND (cl2 # SymTab.ClSByte)
- 1439   AND (cl2 # SymTab.ClWord16)
- 1440   AND (cl2 # SymTab.ClSWord16)) THEN
- 1441                                               SemError(230); ok := FALSE
- 1442                                             ELSIF NOT SymTab.ConstInt(qlo, lo)
- 1443                                                OR NOT SymTab.ConstInt(qhi, hi)
- 1444                                                OR (lo > hi) THEN
- 1445                                               SemError(230); ok := FALSE
- 1446                                              ELSIF NOT SymTab.BoundAdd(lo, hi) THEN
- 1447                                                SemError(230); ok := FALSE
- 1448                                              END;
- 1449                                            END; .) .
- 1450    (* Sets: multi-word masks over bases ≤ 256 values (bool, char,
- 1451       bounded subranges; enums wait for ordinals, INTEGER is
- 1452       unbounded). Literals are SET OF [0..255]; assignment and
- 1453       comparison across suitable bases are lenient (masks over min
- 1454       words + zero-check extras), out-of-span literals are 222. *)
- 1455    SetType<VAR t: SymTab.TypeIndex>      (. VAR base: SymTab.TypeIndex;
- 1456                                               blo, bhi, bspan: INTEGER;
- 1457                                               bcls: INTEGER; .)
- 1458      = "SET"                             (. allowFwdType := FALSE; .)
- 1459        "OF" Type<base, FALSE>
- 1460                                          (. IF base = SymTab.InvalidType THEN
- 1461                                               t := SymTab.InvalidType
- 1462                                             ELSIF SymTab.Unresolved(base) THEN
- 1463                                               (* an opaque/formal base: defer
- 1464                                                  the span check until the
- 1465                                                  base is completed *)
- 1466                                               t := SymTab.NewSet(base)
- 1467                                             ELSE bcls :=
- 1468                                                    SymTab.ClassOf(base);
- 1469                                               (* a subrange keeps its own
- 1470                                                  span even when its base is
- 1471                                                  CHAR/BOOLEAN/an enum *)
- 1472                                               IF SymTab.SubBounds(base,
- 1473                                                       blo, bhi) THEN
- 1474                                                 bspan := bhi - blo + 1
- 1475                                               ELSIF bcls = SymTab.ClBool THEN
- 1476                                                 blo := 0; bspan := 2
- 1477                                               ELSIF bcls = SymTab.ClChar THEN
- 1478                                                 blo := 0; bspan := 256
- 1479                                               ELSIF bcls = SymTab.ClByte THEN
- 1480                                                 blo := 0; bspan := 256
- 1481                                               ELSIF bcls = SymTab.ClSByte THEN
- 1482                                                 blo := -128; bspan := 256
- 1483                                               ELSIF bcls = SymTab.ClWord16 THEN
- 1484                                                 blo := 0; bspan := 65536
- 1485                                               ELSIF bcls = SymTab.ClSWord16 THEN
- 1486                                                 blo := -32768; bspan := 65536
- 1487                                               ELSIF bcls = SymTab.ClEnum THEN
- 1488                                                 blo := 0;
- 1489                                                 bspan := VAL(INTEGER,
- 1490                                                   SymTab.EnumCount(base))
- 1491                                               ELSE bspan := 0 END;
- 1492                                               IF (bspan <= 0)
- 1493                                                  OR (bspan > 65536) THEN
- 1494                                                 SemError(230);
- 1495                                                 t := SymTab.InvalidType
- 1496                                               ELSE t := SymTab.NewSet(base)
- 1497                                               END
- 1498                                             END; .) .
- 1499    (* PACKEDSET: same base rules as SET, but 1/2/4-byte storage.  V3
- 1500       limits the span to 32 bits (SetBytes 1..4); wider packed sets are
- 1501       an implementation limit (230). *)
- 1502    PackSetType<VAR t: SymTab.TypeIndex>  (. VAR base: SymTab.TypeIndex;
- 1503                                               blo, bhi, bspan: INTEGER;
- 1504                                               bcls: INTEGER; .)
- 1505      = "PACKEDSET"                       (. allowFwdType := FALSE; .)
- 1506        "OF" Type<base, FALSE>
- 1507                                          (. IF base = SymTab.InvalidType THEN
- 1508                                               t := SymTab.InvalidType
- 1509                                             ELSIF SymTab.Unresolved(base) THEN
- 1510                                               t := SymTab.NewPackSet(base)
- 1511                                             ELSE bcls :=
- 1512                                                    SymTab.ClassOf(base);
- 1513                                               IF SymTab.SubBounds(base,
- 1514                                                       blo, bhi) THEN
- 1515                                                 bspan := bhi - blo + 1
- 1516                                               ELSIF bcls = SymTab.ClBool THEN
- 1517                                                 blo := 0; bspan := 2
- 1518                                               ELSIF bcls = SymTab.ClChar THEN
- 1519                                                 blo := 0; bspan := 256
- 1520                                               ELSIF bcls = SymTab.ClByte THEN
- 1521                                                 blo := 0; bspan := 256
- 1522                                               ELSIF bcls = SymTab.ClSByte THEN
- 1523                                                 blo := -128; bspan := 256
- 1524                                               ELSIF bcls = SymTab.ClWord16 THEN
- 1525                                                 blo := 0; bspan := 65536
- 1526                                               ELSIF bcls = SymTab.ClSWord16 THEN
- 1527                                                 blo := -32768; bspan := 65536
- 1528                                               ELSIF bcls = SymTab.ClEnum THEN
- 1529                                                 blo := 0;
- 1530                                                 bspan := VAL(INTEGER,
- 1531                                                   SymTab.EnumCount(base))
- 1532                                               ELSE bspan := 0 END;
- 1533                                               IF (bspan <= 0)
- 1534                                                  OR (bspan > 32) THEN
- 1535                                                 SemError(230);
- 1536                                                 t := SymTab.InvalidType
- 1537                                               ELSE t := SymTab.NewPackSet(base)
- 1538                                               END
- 1539                                             END; .) .
- 1540    (* Records: flat blobs; array fields are pointers to static
- 1541       descriptors (locked amendment), nested records inline. Field
- 1542       offsets static and declaration-ordered. *)
- 1543    (* Field list: plain fields and (optionally) one variant part.  The
- 1544       variant part is a `CASE ... END` item; because it starts with the
- 1545       CASE keyword it is unambiguously distinguishable from a field
- 1546       (which starts with an identifier). *)
- 1547    RecordType<VAR t: SymTab.TypeIndex>   (. VAR t2: SymTab.TypeIndex;
- 1548                                               tagOk: BOOLEAN; .)
- 1549      = "RECORD"                          (. allowFwdType := FALSE;
- 1550                                             t := SymTab.NewRecord(); .)
- 1551        [ RecItem<t> { ";" [ RecItem<t> ] } ]
- 1552        "END"                             (. SymTab.LayoutRecord(t); .) .
- 1553    RecItem<rec: SymTab.TypeIndex>        (. VAR tt: SymTab.TypeIndex; .)
- 1554      = RecField<rec>
- 1555      | CaseField<rec>                    (. SymTab.MarkVariant(rec); .) .
- 1556    (* A variant part: CASE [tag] : Type OF variants.  gm2 extensions:
- 1557       an untagged inner CASE (no tag field), empty arms and ELSE arms. *)
- 1558    CaseField<rec: SymTab.TypeIndex>      (. VAR tagT: SymTab.TypeIndex;
- 1559                                               tagN: SymTab.Name;
- 1560                                               tagged: BOOLEAN; .)
- 1561      = "CASE"                            (. SymTab.ResetFields(rec);
- 1562                                             tagged := FALSE; .)
- 1563        [ GetIdent<tagN>                  (. IF NOT SymTab.FieldPending(rec,
- 1564                                               tagN) THEN
- 1565                                               SemError(200) END;
- 1566                                             tagged := TRUE; .) ]
- 1567        ":" Type<tagT, FALSE>             (. IF (tagT # SymTab.InvalidType)
- 1568    AND NOT SymTab.IsOrdinal(tagT) THEN
- 1569                                               SemError(224)
- 1570                                             END;
- 1571                                             IF tagged THEN
- 1572                                               SymTab.FixPendingF(rec, tagT);
- 1573                                               SymTab.SetVariantTag(rec, tagN)
- 1574                                             END; .)
- 1575        "OF"
- 1576        RecFieldList<rec>
- 1577        { "|"                             (. SymTab.ResetFields(rec); .)
- 1578          RecFieldList<rec> }
- 1579        [ "ELSE" ]
- 1580        "END" .
- 1581    (* A variant branch: `labels : fields` (fields and their trailing ";"
- 1582       optional, gm2), `ELSE`, or empty (the extra "|" separators gm2
- 1583       tolerates).  A branch may itself contain a nested variant CASE. *)
- 1584    RecFieldList<rec: SymTab.TypeIndex>   (. VAR lt, lq: SymTab.TypeIndex;
- 1585                                               lv1, lv2: QbeGen.QVal; .)
- 1586      = [ ( VarLabel<lt, lv1> [ ".." VarLabel<lq, lv2> ]
- 1587            { "," VarLabel<lt, lv1> [ ".." VarLabel<lq, lv2> ] }
- 1588            ":"
- 1589            [ ArmField<rec> { ";" [ ArmField<rec> ] } ]
- 1590          | "ELSE" ) ] .
- 1591    ArmField<rec: SymTab.TypeIndex>
- 1592      = RecField<rec>
- 1593      | CaseField<rec>                    (. SymTab.MarkVariant(rec); .) .
- 1594    (* Variant case label: a constant (or a constant range).  Values are
- 1595       not interpreted (the layout overlays regardless). *)
- 1596    VarLabel<VAR t: SymTab.TypeIndex; VAR q: QbeGen.QVal>
- 1597                                          (. VAR lname: SymTab.Name; .)
- 1598      = ( ident                         (. LexName(lname);
- 1599                                             QbeGen.CopyOp("0", q);
- 1600                                             t := SymTab.IntType(); .)
- 1601        | integer                       (. LexString(lname);
- 1602                                             QbeGen.CopyOp("0", q);
- 1603                                             t := SymTab.IntType(); .)
- 1604        | charConst                     (. LexString(lname);
- 1605                                             QbeGen.CopyOp("0", q);
- 1606                                             t := SymTab.CharType(); .) ) .
- 1607    RecField<rec: SymTab.TypeIndex>       (. VAR n: SymTab.Name;
- 1608                                               t2: SymTab.TypeIndex; .)
- 1609      = RecIdents<rec> ":" Type<t2, FALSE>(. SymTab.FixPendingF(rec, t2); .) .
- 1610    RecIdents<rec: SymTab.TypeIndex>      (. VAR n: SymTab.Name; .)
- 1611      = GetIdent<n>                       (. IF NOT SymTab.FieldPending(rec,
- 1612                                               n) THEN
- 1613                                               SemError(200) END; .)
- 1614        { "," GetIdent<n>                 (. IF NOT SymTab.FieldPending(rec,
- 1615                                               n) THEN
- 1616                                               SemError(200) END; .) } .
- 1617    TypeIdent<VAR t: SymTab.TypeIndex>    (. VAR n, qid: SymTab.Name;
- 1618                                               k: INTEGER;
- 1619                                               dotted: BOOLEAN; .)
- 1620      = GetIdent<n>                       (. dotted := FALSE;
- 1621                                             IF NOT SymTab.Lookup(n) THEN
- 1622                                               (* declaration before use: an
- 1623                                                  undeclared type is 201,
- 1624                                                  except as a POINTER's base
- 1625                                                  (allowFwdType) *)
- 1626                                               k := -1;
- 1627                                               IF allowFwdType THEN
- 1628                                                 t := SymTab.ForwardType(n)
- 1629                                               ELSE t := SymTab.InvalidType
- 1630                                               END;
- 1631                                               IF t = SymTab.InvalidType THEN
- 1632                                                 SemError(201)
- 1633                                               END
- 1634                                             ELSE k := SymTab.SymKind(n);
- 1635                                               IF (k = SymTab.KindType)
- 1636                                                  OR (k = SymTab.KindPredef) THEN
- 1637                                                 t := SymTab.SymType(n)
- 1638                                               ELSE t := SymTab.InvalidType
- 1639                                               END
- 1640                                             END; .)
- 1641        [ "." GetIdent<qid>               (. dotted := TRUE;
- 1642                                             IF k = SymTab.KindModule THEN
- 1643                                               t := SymTab.QualType(n, qid);
- 1644                                               IF t = SymTab.InvalidType THEN
- 1645                                                 SemError(201)
- 1646                                               END
- 1647                                             ELSE SemError(221);
- 1648                                               t := SymTab.InvalidType
- 1649                                             END; .) ]
- 1650                                          (. IF NOT dotted THEN
- 1651                                               IF (k = SymTab.KindModule)
- 1652                                                  OR ((k # SymTab.KindType)
- 1653    AND (k # SymTab.KindPredef)
- 1654    AND (k # SymTab.KindImport)
- 1655    AND (k # -1)) THEN
- 1656                                                 SemError(221)
- 1657                                               END
- 1658                                             END; .) .
- 1659    Subrange<VAR t: SymTab.TypeIndex>     (. VAR tlo, thi: SymTab.TypeIndex;
- 1660                                               qlo, qhi: QbeGen.QVal;
- 1661                                               lo, hi: INTEGER; .)
- 1662      = "[" Expr<tlo, qlo> ".." Expr<thi, qhi>
- 1663                                          (. IF (tlo = SymTab.InvalidType)
- 1664                                              OR (thi = SymTab.InvalidType) THEN
- 1665                                             t := SymTab.InvalidType
- 1666                                           ELSIF NOT SymTab.IsOrdinal(tlo)
- 1667                                              OR NOT SymTab.IsOrdinal(thi) THEN
- 1668                                             SemError(230);
- 1669                                             t := SymTab.InvalidType
- 1670                                           ELSIF NOT SymTab.ConstInt(qlo, lo)
- 1671                                              OR NOT SymTab.ConstInt(qhi, hi)
- 1672                                              OR (lo > hi) THEN
- 1673                                             SemError(230);
- 1674                                             t := SymTab.InvalidType
- 1675                                           ELSE IF SymTab.SameType(tlo, thi) THEN
- 1676                                             (* keep the base type: ['A'..'Z']
- 1677                                                is character, [red..blue]
- 1678                                                that enumeration *)
- 1679                                             t := SymTab.NewSubB(lo, hi, tlo)
- 1680                                           ELSE t := SymTab.NewSubR(lo, hi)
- 1681                                           END
- 1682                                           END; .)
- 1683        "]" .
- 1684    Enum<VAR t: SymTab.TypeIndex>         (. VAR n: SymTab.Name;
- 1685                                               ord: INTEGER;
- 1686                                               qv: QbeGen.QVal; .)
- 1687      = "("                               (. t := SymTab.NewEnum();
- 1688                                             ord := 0; .)
- 1689        GetIdent<n>                       (. IF NOT SymTab.Enter(n,
- 1690                                               SymTab.KindConst) THEN
- 1691                                               SemError(200) END;
- 1692                                             SymTab.SetSymType(n, t);
- 1693                                             QbeGen.IntStr(ord, qv);
- 1694                                             SymTab.SetSymVal(n, qv);
- 1695                                             SymTab.NoteEnumLit(t, n);
- 1696                                             Lower.NoteVar(n,
- 1697                                               SymTab.KindConst, t);
- 1698                                             Lower.NoteConstVal(qv);
- 1699                                             INC(ord); .)
- 1700        { "," GetIdent<n>                 (. IF NOT SymTab.Enter(n,
- 1701                                               SymTab.KindConst) THEN
- 1702                                               SemError(200) END;
- 1703                                             SymTab.SetSymType(n, t);
- 1704                                             QbeGen.IntStr(ord, qv);
- 1705                                             SymTab.SetSymVal(n, qv);
- 1706                                             SymTab.NoteEnumLit(t, n);
- 1707                                             Lower.NoteVar(n,
- 1708                                               SymTab.KindConst, t);
- 1709                                             Lower.NoteConstVal(qv);
- 1710                                             INC(ord); .) }
- 1711        ")"                               (. SymTab.SetEnumCount(t,
- 1712                                               VAL(CARDINAL, ord)); .) .
- 1713    (* Clarion-form classes (docs/OOP.txt): declaration + single
- 1714       inheritance + IMPLEMENTATION blocks. Scopes and member checks
- 1715       now; lowering (vtable, dispatch, THIS) later — one 230 per
- 1716       class/impl block. Methods end with ";" per the Table example
- 1717       (not "," as in the sketch). No underscores in identifiers. *)
- 1718    (* Single CLASS item in both loops: separating declaration from
- 1719       IMPLEMENTATION at the loop level needs 2-token lookahead
- 1720       (CLASS ident vs CLASS IMPLEMENTATION), which LL(1) cannot do.
- 1721       The second token decides after CLASS is consumed. A misplaced
- 1722       CLASS IMPLEMENTATION inside TYPE still parses (harmless: the
- 1723       whole unit ends 230 until lowering). *)
- 1724    ClassItem
- 1725      = "CLASS" ( "IMPLEMENTATION" ClassImplRest | ClassRest ) .
- 1726    ClassRest                             (. VAR cn, m2, pn: SymTab.Name;
- 1727                                               ct: SymTab.TypeIndex; .)
- 1728      = GetIdent<cn>                      (. IF NOT SymTab.Enter(cn,
- 1729                                               SymTab.KindType) THEN
- 1730                                               SemError(200) END;
- 1731                                             ct := SymTab.NewClass();
- 1732                                             SymTab.SetSymType(cn, ct);
- 1733                                             SymTab.PushClassScope(ct);
- 1734                                             astCls := AST.MakeNode(AST.NkClassDecl);
- 1735                                             AST.SetChild(astCls, 0,
- 1736                                               AST.MakeLeaf(AST.NkIdent, cn));
- 1737                                             astClsP := AST.NoNode;
- 1738                                             astClsPTail := AST.NoNode;
- 1739                                             astClsF := AST.NoNode;
- 1740                                             astClsFTail := AST.NoNode;
- 1741                                             astClsM := AST.NoNode;
- 1742                                             astClsMTail := AST.NoNode; .)
- 1743        [ Parents<ct> ]
- 1744        ";"
- 1745        { ClassField<ct> ";" }
- 1746        { MethodHeading<pn, SymTab.InvalidType> ";"
- 1747                                          (. Lower.ScopeLeave;
- 1748                                             SymTab.CloseProc;
- 1749                                             QbeGen.AbortFunc; .) }
- 1750        "END"
- 1751        GetIdent<m2>                      (. IF NOT SymTab.Equal(cn, m2) THEN
- 1752                                               SemError(202) END;
- 1753                                             SymTab.LayoutClass(ct);
- 1754                                             SymTab.PopScope;
- 1755                                             AST.SetChild(astCls, 1, astClsP);
- 1756                                             AST.SetChild(astCls, 2, astClsF);
- 1757                                             AST.SetChild(astCls, 3, astClsM);
- 1758                                             astDecl := astCls; .) .
- 1759    Parents<ct: SymTab.TypeIndex>         (. VAR p: SymTab.Name; .)
- 1760      = "(" Parent1<ct>
- 1761        { "," GetIdent<p>                 (. SemError(230); .) }
- 1762        ")" .
- 1763    Parent1<ct: SymTab.TypeIndex>         (. VAR p: SymTab.Name;
- 1764                                               pt: SymTab.TypeIndex; .)
- 1765      = GetIdent<p>                       (. IF NOT SymTab.Lookup(p) THEN
- 1766                                               SemError(201)
- 1767                                             ELSE pt := SymTab.SymType(p);
- 1768                                               IF SymTab.ClassOf(pt) #
- 1769                                                  SymTab.ClClass THEN
- 1770                                                 SemError(230)
- 1771                                               ELSE SymTab.SetParent(ct, pt)
- 1772                                               END
- 1773                                             END;
- 1774                                             AstAppend(AST.NkFieldDecl,
- 1775                                               astClsP, astClsPTail,
- 1776                                               AST.MakeLeaf(AST.NkIdent, p)); .) .
- 1777    ClassField<ct: SymTab.TypeIndex>      (. VAR n, rhs: SymTab.Name;
- 1778                                               t: SymTab.TypeIndex;
- 1779                                               astNode: AST.Node; .)
- 1780      = GetIdent<n>
- 1781        ( "=" GetIdent<rhs>               (. IF NOT SymTab.Enter(n,
- 1782                                               SymTab.KindConst) THEN
- 1783                                               SemError(200) END;
- 1784                                             astNode := AST.MakeNode(AST.NkConstDecl);
- 1785                                             AST.SetChild(astNode, 0,
- 1786                                               AST.MakeLeaf(AST.NkIdent, n));
- 1787                                             AST.SetChild(astNode, 1,
- 1788                                               AST.MakeLeaf(AST.NkIdent, rhs));
- 1789                                             AstAppend(AST.NkFieldDecl,
- 1790                                               astClsF, astClsFTail, astNode);
- 1791                                             IF SymTab.Lookup(rhs) THEN
- 1792                                               SymTab.SetSymType(n,
- 1793                                                 SymTab.SymType(rhs))
- 1794                                             END; .)
- 1795        |                                 (. IF NOT SymTab.FieldPending(ct,
- 1796                                               n) THEN
+  884                                             AST.SetChild(astUnit, 1, astSeq);
+  885                                             AST.SetChild(astUnit, 3, astImp);
+  886                                             astDecl := AST.NoNode;
+  887                                             astStmt := AST.NoNode; .)
+  888        "END"
+  889        GetIdent<m2>                      (. IF instActive THEN InstNameGet(m2) END;
+  890                                             IF NOT SymTab.Equal(m1, m2) THEN
+  891                                               SemError(202) END;
+  892                                             SymTab.EndUnit; .)
+  893        | "=" GetIdent<g> [ "(" Actuals ")" ] ";"
+  894                                          (. CopyNm(m1, refInst);
+  895                                             CopyNm(g, refGen);
+  896                                             refSeen := TRUE; refIsDef := TRUE;
+  897                                             astUnit := AST.MakeNode(AST.NkUnit);
+  898                                             AST.SetChild(astUnit, 0,
+  899                                               AST.MakeLeaf(AST.NkIdent, m1));
+  900                                             astDecl := AST.NoNode;
+  901                                             astStmt := AST.NoNode; .)
+  902          "END"
+  903          GetIdent<m2>                    (. IF NOT SymTab.Equal(m1, m2) THEN
+  904                                               SemError(202) END;
+  905                                             SymTab.EndUnit; .) ) .
+  906    ImplUnit                              (. VAR m1, m2: SymTab.Name;
+  907                                               g: SymTab.Name;
+  908                                               k: CARDINAL;
+  909                                               rp: CARDINAL;
+  910                                               rpOk: BOOLEAN;
+  911                                               rErrs: INTEGER;
+  912                                               rDecl, rStmt: AST.Node;
+  913                                               rnm: SymTab.Name;
+  914                                               rSym, rErr: CARDINAL;
+  915                                               fname: SymTab.Name;
+  916                                               unres: BOOLEAN;
+  917                                               astNode: AST.Node;
+  918                                               astBody, astHandler: AST.Node;
+  919                                               hasExcept: BOOLEAN; .)
+  920      =                                   (. refN := 0; refSeen := FALSE;
+  921                                             inHandler := FALSE;
+  922                                             astHandler := AST.NoNode;
+  923                                             hasExcept := FALSE; .)
+  924        "IMPLEMENTATION" "MODULE"
+  925        [ "FOR" string ]                  (* ISO foreign module: FOR "C" *)
+  926        GetIdent<m1> (. IF instActive THEN InstNameGet(m1) END;
+  927                       IF instActive THEN
+  928                         IF NOT SymTab.Reenter(m1,
+  929                                SymTab.UnitImpl) THEN
+  930                           SemError(201) END
+  931                       ELSIF NOT SymTab.BeginImpl(m1) THEN
+  932                         SemError(201) END;
+  933                       astStmt := AST.NoNode;
+  934                       astDecl := AST.NoNode;
+  935                       astImp := AST.NoNode;
+  936                       astImpTail := AST.NoNode;
+  937                       nPendVar := 0;
+  938                       CopyNm(m1, unitName);
+  939                       unitWasGen := isGen AND NOT instActive;
+  940                       unitWasDef := FALSE;
+  941                       QbeGen.SetModule(m1); .)
+  942        [ GenericFormals ]
+  943        ( ";"
+  944        { Import                        (. AstAppend(AST.NkDeclSeq,
+  945                                               astImp, astImpTail, astDecl); .) }
+  946        DeclSeq                           (. astStmt := AST.NoNode; .)
+  947        [ "BEGIN"                         (. FlushPend;
+  948                                             k := 0;
+  949                                             WHILE k < SymTab.FwdPending() DO
+  950                                               SymTab.FwdInfo(k, fname, unres);
+  951                                               IF unres THEN SemError(201) END;
+  952                                               INC(k)
+  953                                             END;
+  954                                             SymTab.FwdClear;
+  955  
+  956                                             nLab := 0; nGot := 0; .)
+  957          [ StatSeq ] ]
+  958                                          (. astBody := astStmt; .)
+  959        [ "EXCEPT"                        (. (* M1: grammar/AST only; M2 removes
+  960                                                this 230 and adds codegen. *)
+  961                                             SemError(230);
+  962                                             hasExcept := TRUE;
+  963                                             inHandler := TRUE; .)
+  964          [ StatSeq ]                     (. astHandler := astStmt;
+  965                                             inHandler := FALSE .) ]
+  966                                          (. IF twoPhaseParse THEN
+  967                                               rSym := sym; rErr := errDist;
+  968                                               rDecl := astDecl; rStmt := astBody;
+  969                                               M2S.PushPos;
+  970                                               repassing := TRUE;
+  971                                               rp := 0;
+  972                                               WHILE rp < nSpans DO
+  973                                                 k := 0;
+  974                                                 WHILE (k <= HIGH(rnm))
+  975                                                   AND (spanName[rp][k] # CHR(0)) DO
+  976                                                   rnm[k] := spanName[rp][k]; INC(k)
+  977                                                 END;
+  978                                                 rnm[k] := CHR(0);
+  979                                                 M2S.SeekTo(spanStart[rp]);
+  980                                                 Adv;
+  981                                                 rpOk := SymTab.ReenterDeferred(spanIdx[rp]);
+  982                                                 IF NOT rpOk THEN
+  983                                                   FileIO.WriteString(FileIO.StdOut,
+  984                                                     "twophase reenter failed");
+  985                                                   FileIO.WriteLn(FileIO.StdOut)
+  986                                                 END;
+  987                                                 Lower.ReenterScopeProc(spanTy[rp]);
+  988                                                 QbeGen.BeginFunc("");
+  989                                                 CopyNm(rnm, curFun);
+  990                                                 Block(rnm);
+  991                                                 AST.SetChild(spanNode[rp], 1, astStmt);
+  992                                                 AST.SetChild(spanNode[rp], 2, astBlkDecls);
+  993                                                 Lower.ScopeLeave;
+  994                                                 SymTab.CloseProc;
+  995                                                 QbeGen.EndFunc(SymTab.ProcRes(rnm));
+  996                                                 INC(rp)
+  997                                               END;
+  998                                               curFun[0] := CHR(0);
+  999                                               SymTab.OrderCheckOff; rErrs := M2S.errors;
+ 1000                                               repassing := FALSE;
+ 1001                                               M2S.PopPos;
+ 1002                                               sym := rSym; errDist := rErr;
+ 1003                                               M2S.errors := rErrs;
+ 1004  
+ 1005                                               astDecl := rDecl; astStmt := rStmt
+ 1006                                             END; .)
+ 1007        "END"
+ 1008        GetIdent<m2>                      (. IF instActive THEN InstNameGet(m2) END;
+ 1009                                             FlushPend;
+ 1010                                             k := 0;
+ 1011                                             WHILE k < SymTab.FwdPending() DO
+ 1012                                               SymTab.FwdInfo(k, fname, unres);
+ 1013                                               IF unres THEN SemError(201) END;
+ 1014                                               INC(k)
+ 1015                                             END;
+ 1016                                             SymTab.FwdClear;
+ 1017  
+ 1018                                             IF hasExcept THEN
+ 1019                                               astStmt := WrapExcept(astBody,
+ 1020                                                             astHandler)
+ 1021                                             END;
+ 1022                                             astNode := AST.MakeNode(AST.NkUnit);
+ 1023                                             AST.SetChild(astNode, 0,
+ 1024                                               AST.MakeLeaf(AST.NkIdent, m1));
+ 1025                                             AST.SetChild(astNode, 1, astDecl);
+ 1026                                             AST.SetChild(astNode, 2, astStmt);
+ 1027                                             AST.SetChild(astNode, 3, astImp);
+ 1028                                             astUnit := astNode;
+ 1029                                             IF NOT SymTab.Equal(m1, m2) THEN
+ 1030                                               SemError(202) END;
+ 1031                                             CheckGotos;
+ 1032                                             SymTab.EndUnit; .)
+ 1033        | "=" GetIdent<g> [ "(" Actuals ")" ] ";"
+ 1034                                          (. CopyNm(m1, refInst);
+ 1035                                             CopyNm(g, refGen);
+ 1036                                             refSeen := TRUE; refIsDef := FALSE;
+ 1037                                             astNode := AST.MakeNode(AST.NkUnit);
+ 1038                                             AST.SetChild(astNode, 0,
+ 1039                                               AST.MakeLeaf(AST.NkIdent, m1));
+ 1040                                             astDecl := AST.NoNode;
+ 1041                                             astStmt := AST.NoNode; .)
+ 1042          { Import                        (. (* refinement unit import *) .) }
+ 1043          "END"
+ 1044          GetIdent<m2>                    (. IF NOT SymTab.Equal(m1, m2) THEN
+ 1045                                               SemError(202) END;
+ 1046                                             SymTab.EndUnit; .) ) .
+ 1047    ProgModule                            (. VAR m1, m2: SymTab.Name;
+ 1048                                               k: CARDINAL;
+ 1049                                               rp: CARDINAL;
+ 1050                                               rpOk: BOOLEAN;
+ 1051                                               rErrs: INTEGER;
+ 1052                                               rDecl, rStmt: AST.Node;
+ 1053                                               rnm: SymTab.Name;
+ 1054                                               rSym, rErr: CARDINAL;
+ 1055                                               fname: SymTab.Name;
+ 1056                                               unres: BOOLEAN;
+ 1057                                               astNode: AST.Node;
+ 1058                                               astBody, astHandler: AST.Node;
+ 1059                                               hasExcept: BOOLEAN; .)
+ 1060      =                                   (. inHandler := FALSE;
+ 1061                                             astHandler := AST.NoNode;
+ 1062                                             hasExcept := FALSE; .)
+ 1063        "MODULE"
+ 1064        GetIdent<m1> (. IF NOT SymTab.BeginProg(m1) THEN
+ 1065                                               SemError(200) END;
+ 1066                                             astStmt := AST.NoNode;
+ 1067                                             astDecl := AST.NoNode;
+ 1068                                             astImp := AST.NoNode;
+ 1069                                             astImpTail := AST.NoNode;
+ 1070                                             nPendVar := 0;
+ 1071                                             QbeGen.SetModule(m1);
+ 1072                                             CopyNm(m1, unitName); .)
+ 1073        [ Priority ]
+ 1074        ";"
+ 1075        { Import                        (. AstAppend(AST.NkDeclSeq,
+ 1076                                               astImp, astImpTail, astDecl); .) }
+ 1077        DeclSeq                           (. astStmt := AST.NoNode; .)
+ 1078        [ "BEGIN"                         (. FlushPend;
+ 1079                                             k := 0;
+ 1080                                             WHILE k < SymTab.FwdPending() DO
+ 1081                                               SymTab.FwdInfo(k, fname, unres);
+ 1082                                               IF unres THEN SemError(201) END;
+ 1083                                               INC(k)
+ 1084                                             END;
+ 1085                                             SymTab.FwdClear;
+ 1086  
+ 1087                                             nLab := 0; nGot := 0; .)
+ 1088          [ StatSeq ] ]
+ 1089                                          (. astBody := astStmt; .)
+ 1090        [ "EXCEPT"                        (. (* M1: grammar/AST only; M2 removes
+ 1091                                                this 230 and adds codegen. *)
+ 1092                                             SemError(230);
+ 1093                                             hasExcept := TRUE;
+ 1094                                             inHandler := TRUE; .)
+ 1095          [ StatSeq ]                     (. astHandler := astStmt;
+ 1096                                             inHandler := FALSE .) ]
+ 1097                                          (. IF twoPhaseParse THEN
+ 1098                                               rSym := sym; rErr := errDist;
+ 1099                                               rDecl := astDecl; rStmt := astBody;
+ 1100                                               M2S.PushPos;
+ 1101                                               repassing := TRUE;
+ 1102                                               rp := 0;
+ 1103                                               WHILE rp < nSpans DO
+ 1104                                                 k := 0;
+ 1105                                                 WHILE (k <= HIGH(rnm))
+ 1106                                                   AND (spanName[rp][k] # CHR(0)) DO
+ 1107                                                   rnm[k] := spanName[rp][k]; INC(k)
+ 1108                                                 END;
+ 1109                                                 rnm[k] := CHR(0);
+ 1110                                                 M2S.SeekTo(spanStart[rp]);
+ 1111                                                 Adv;
+ 1112                                                 rpOk := SymTab.ReenterDeferred(spanIdx[rp]);
+ 1113                                                 IF NOT rpOk THEN
+ 1114                                                   FileIO.WriteString(FileIO.StdOut,
+ 1115                                                     "twophase reenter failed");
+ 1116                                                   FileIO.WriteLn(FileIO.StdOut)
+ 1117                                                 END;
+ 1118                                                 Lower.ReenterScopeProc(spanTy[rp]);
+ 1119                                                 QbeGen.BeginFunc("");
+ 1120                                                 CopyNm(rnm, curFun);
+ 1121                                                 Block(rnm);
+ 1122                                                 AST.SetChild(spanNode[rp], 1, astStmt);
+ 1123                                                 AST.SetChild(spanNode[rp], 2, astBlkDecls);
+ 1124                                                 Lower.ScopeLeave;
+ 1125                                                 SymTab.CloseProc;
+ 1126                                                 QbeGen.EndFunc(SymTab.ProcRes(rnm));
+ 1127                                                 INC(rp)
+ 1128                                               END;
+ 1129                                               curFun[0] := CHR(0);
+ 1130                                               SymTab.OrderCheckOff; rErrs := M2S.errors;
+ 1131                                               repassing := FALSE;
+ 1132                                               M2S.PopPos;
+ 1133                                               sym := rSym; errDist := rErr;
+ 1134                                               M2S.errors := rErrs;
+ 1135  
+ 1136                                               astDecl := rDecl; astStmt := rStmt
+ 1137                                             END; .)
+ 1138        "END"
+ 1139        GetIdent<m2>                      (. IF instActive THEN InstNameGet(m2) END;
+ 1140                                             FlushPend;
+ 1141                                             k := 0;
+ 1142                                             WHILE k < SymTab.FwdPending() DO
+ 1143                                               SymTab.FwdInfo(k, fname, unres);
+ 1144                                               IF unres THEN SemError(201) END;
+ 1145                                               INC(k)
+ 1146                                             END;
+ 1147                                             SymTab.FwdClear;
+ 1148  
+ 1149                                             IF NOT SymTab.Equal(m1, m2) THEN
+ 1150                                               SemError(202) END;
+ 1151                                             IF hasExcept THEN
+ 1152                                               astStmt := WrapExcept(astBody,
+ 1153                                                             astHandler)
+ 1154                                             END;
+ 1155                                             astNode := AST.MakeNode(AST.NkUnit);
+ 1156                                             AST.SetChild(astNode, 0,
+ 1157                                               AST.MakeLeaf(AST.NkIdent, m1));
+ 1158                                             AST.SetChild(astNode, 1, astDecl);
+ 1159                                             AST.SetChild(astNode, 2, astStmt);
+ 1160                                             AST.SetChild(astNode, 3, astImp);
+ 1161                                             astUnit := astNode;
+ 1162                                             CheckGotos;
+ 1163                                             SymTab.EndUnit; .) .
+ 1164    DeclSeq                               (. VAR astSeq, astTail: AST.Node; .)
+ 1165      =                                   (. astSeq := AST.NoNode;
+ 1166                                             astTail := AST.NoNode; .)
+ 1167        { (. astDecl := AST.NoNode; .)
+ 1168          ( ConstBlock | TypeBlock<FALSE> | VarBlock | ProcDecl ";"
+ 1169          | NestedModule ";" | ClassItem ";" )
+ 1170                                          (. AstAppend(AST.NkDeclSeq,
+ 1171                                               astSeq, astTail, astDecl); .) }
+ 1172                                          (. astDecl := astSeq; .) .
+ 1173    (* Local module, Wirth form. Declarations lower like top-level ones
+ 1174       (same QBE module prefix); a BEGIN body becomes an init function
+ 1175       that main calls; the EXPORT list is hoisted into the enclosing
+ 1176       scope at END. *)
+ 1177    NestedModule                          (. VAR m1, m2: SymTab.Name;
+ 1178                                               expNames: ARRAY [0 .. 63] OF SymTab.Name;
+ 1179                                               expCount, k: CARDINAL;
+ 1180                                               astNode, nImp, nImpTail:
+ 1181                                                 AST.Node;
+ 1182                                               astBody, astHandler: AST.Node;
+ 1183                                               hasExcept: BOOLEAN; .)
+ 1184      =                                   (. inHandler := FALSE;
+ 1185                                             astHandler := AST.NoNode;
+ 1186                                             hasExcept := FALSE; .)
+ 1187        "MODULE"
+ 1188        GetIdent<m1>                      (. IF NOT SymTab.Enter(m1,
+ 1189                                               SymTab.KindModule) THEN
+ 1190                                               SemError(200) END;
+ 1191                                             SymTab.PushScope;
+ 1192                                             expCount := 0;
+ 1193                                             astNode := AST.MakeNode(AST.NkUnit);
+ 1194                                             AST.SetChild(astNode, 0,
+ 1195                                               AST.MakeLeaf(AST.NkIdent, m1));
+ 1196                                             astStmt := AST.NoNode;
+ 1197                                             astDecl := AST.NoNode;
+ 1198                                             nImp := AST.NoNode;
+ 1199                                             nImpTail := AST.NoNode; .)
+ 1200        [ Priority ]
+ 1201        ";"
+ 1202        { Import                        (. AstAppend(AST.NkDeclSeq,
+ 1203                                               nImp, nImpTail, astDecl); .) }
+ 1204        [ "EXPORT" [ "QUALIFIED" | "UNQUALIFIED" ]
+ 1205          GetIdent<expNames[expCount]>    (. INC(expCount); .)
+ 1206          { "," GetIdent<expNames[expCount]>
+ 1207                                          (. INC(expCount); .) }
+ 1208          ";" ]
+ 1209        DeclSeq                           (. astStmt := AST.NoNode; .)
+ 1210        [ "BEGIN"                         (. astStmt := AST.NoNode;
+ 1211                                             .)
+ 1212          [ StatSeq ] ]
+ 1213                                          (. astBody := astStmt; .)
+ 1214        [ "EXCEPT"                        (. (* M1: grammar/AST only; M2 removes
+ 1215                                                this 230 and adds codegen. *)
+ 1216                                             SemError(230);
+ 1217                                             hasExcept := TRUE;
+ 1218                                             inHandler := TRUE; .)
+ 1219          [ StatSeq ]                     (. astHandler := astStmt;
+ 1220                                             inHandler := FALSE .) ]
+ 1221        "END"
+ 1222        GetIdent<m2>                      (. IF hasExcept THEN
+ 1223                                               astStmt := WrapExcept(astBody,
+ 1224                                                             astHandler)
+ 1225                                             END;
+ 1226                                             AST.SetChild(astNode, 1, astDecl);
+ 1227                                             AST.SetChild(astNode, 2, astStmt);
+ 1228                                             AST.SetChild(astNode, 3, nImp);
+ 1229                                             astDecl := astNode;
+ 1230                                             IF NOT SymTab.Equal(m1, m2) THEN
+ 1231                                               SemError(202) END;
+ 1232                                             k := 0;
+ 1233                                             WHILE k < expCount DO
+ 1234                                               SymTab.ExportUp(expNames[k]);
+ 1235                                               INC(k)
+ 1236                                             END;
+ 1237                                             SymTab.PopScope; .) .
+ 1238    Priority
+ 1239      = "[" integer "]"                   (. SemError(230); .) .
+ 1240    (* Imports (4.3): FROM materializes the names (unqualified use);
+ 1241       plain IMPORT only demands the module exists — qualified `L.x`
+ 1242       materializes on first use (Design). *)
+ 1243    (* Unknown modules stay unchecked stubs (legacy, so hand-written
+ 1244       import lines don't fail); a known module's missing export is
+ 1245       201. *)
+ 1246    Import                                (. VAR n: SymTab.Name;
+ 1247                                               astImport: AST.Node; .)
+ 1248      = "FROM"
+ 1249        GetIdent<n>                       (. astImport := AST.MakeNode(AST.NkImport);
+ 1250                                             AST.SetChild(astImport, 0,
+ 1251                                               AST.MakeLeaf(AST.NkIdent, n)); .)
+ 1252        "IMPORT"
+ 1253        ImpList<n, astImport> ";"         (. astDecl := astImport; .)
+ 1254      | "IMPORT"                          (. astImport := AST.MakeNode(AST.NkImport); .)
+ 1255        ImpModList<astImport> ";"         (. astDecl := astImport; .) .
+ 1256    ImpList<mod: SymTab.Name; node: AST.Node>
+ 1257                                          (. VAR n: SymTab.Name; .)
+ 1258      = ImpName<mod, node>
+ 1259        { "," ImpName<mod, node> } .
+ 1260    (* Pervasive built-ins imported from SYSTEM (e.g. TSIZE) are
+ 1261       accepted and ignored: the built-in applies regardless. *)
+ 1262    ImpName<mod: SymTab.Name; node: AST.Node>
+ 1263                                          (. VAR n: SymTab.Name; .)
+ 1264      = GetIdent<n> (. AST.SetChild(node, AST.NChild(node),
+ 1265                                               AST.MakeLeaf(AST.NkIdent, n));
+ 1266                                             IF SymTab.Equal(mod, "libc") THEN
+ 1267                                               (* intrinsic C library:
+ 1268                                                  permissive external *)
+ 1269                                               IF NOT SymTab.DeclareCProc(n) THEN
+ 1270                                                 SemError(201) END;
+ 1271                                               Lower.NoteCProc(n)
+ 1272                                             ELSIF SymTab.ModKnown(mod)
+ 1273                                                AND NOT SymTab.Equal(mod,
+ 1274                                                  "SYSTEM") THEN
+ 1275                                               IF NOT SymTab.ImportFrom(mod, n) THEN
+ 1276                                                 SemError(201)
+ 1277                                               ELSE Lower.NoteImportedProc(n)
+ 1278                                               END
+ 1279                                             END; .)
+ 1280      | ( "TSIZE" | "SIZE" | "ADR" | "HIGH" | "LEN"
+ 1281        | "CHR" | "ORD" | "VAL" | "ABS" | "CAP"
+ 1282        | "ODD" | "TRUNC" | "FLOAT"
+ 1283        | "UCHR" | "CHR8" | "UORD"
+ 1284        | "INC" | "DEC"
+ 1285        | "SHIFT" | "ROTATE" | "CAST" | "CONVERT" | "MIN" | "MAX"
+ 1286        | "INCL" | "EXCL" | "NEW" | "DISPOSE" | "LOC" ) .
+ 1287    ImpModList<node: AST.Node>            (. VAR n: SymTab.Name; .)
+ 1288      = GetIdent<n>                       (. AST.SetChild(node, AST.NChild(node),
+ 1289                                               AST.MakeLeaf(AST.NkIdent, n)); .)
+ 1290        { "," GetIdent<n>                 (. AST.SetChild(node, AST.NChild(node),
+ 1291                                               AST.MakeLeaf(AST.NkIdent, n)); .) } .
+ 1292    (* Opaque TYPE declarations (definition modules). The targetless
+ 1293       alias resolves to InvalidType until step 4 completes it. *)
+ 1294    (* Scalar-phase TYPEs: named types, integer subranges, enumerations.
+ 1295       Opaque "TYPE T;" needs isDef (definition units); elsewhere 231.
+ 1296       Composite forms (ARRAY/RECORD/SET/POINTER) arrive with step 3. *)
+ 1297    TypeBlock<isDef: BOOLEAN>             (. VAR astSeq, astTail: AST.Node; .)
+ 1298      = "TYPE"                            (. SymTab.BeginTypeBlock;
+ 1299                                             astSeq := AST.NoNode;
+ 1300                                             astTail := AST.NoNode; .)
+ 1301        { (. astDecl := AST.NoNode; .)
+ 1302          ( TypeItem<isDef> ";" | ClassItem ";" )
+ 1303                                          (. AstAppend(AST.NkDeclSeq,
+ 1304                                               astSeq, astTail, astDecl); .) }
+ 1305                                          (. SymTab.EndTypeBlock;
+ 1306                                             astDecl := astSeq; .) .
+ 1307    TypeItem<isDef: BOOLEAN>              (. VAR n: SymTab.Name;
+ 1308                                               t, op: SymTab.TypeIndex;
+ 1309                                               astNode: AST.Node; .)
+ 1310      = GetIdent<n>                       (. op := SymTab.OpaqueBase(n);
+ 1311                                             IF op = SymTab.InvalidType THEN
+ 1312                                               IF NOT SymTab.Enter(n,
+ 1313                                                  SymTab.KindType) THEN
+ 1314                                                 SemError(200) END
+ 1315                                             END; .)
+ 1316        ( "=" Type<t, FALSE> (. astNode := AST.MakeNode(AST.NkTypeDecl);
+ 1317                                               AST.SetChild(astNode, 0,
+ 1318                                                 AST.MakeLeaf(AST.NkIdent, n));
+ 1319                                               AST.SetTy(astNode, t);
+ 1320                                               astDecl := astNode;
+ 1321                                               IF op # SymTab.InvalidType THEN
+ 1322                                               SymTab.SetTarget(op, t)
+ 1323                                             ELSE SymTab.SetSymType(n, t)
+ 1324                                             END;
+ 1325                                             IF SymTab.EnterEnumLits(t) > 0 THEN END; .)
+ 1326        |                                 (. IF op # SymTab.InvalidType THEN
+ 1327                                               (* stays opaque *)
+ 1328                                             ELSIF NOT isDef THEN
+ 1329                                               SemError(231)
+ 1330                                             ELSE SymTab.SetSymType(n,
+ 1331                                               SymTab.NewAlias()) END; .) ) .
+ 1332    Type<VAR t: SymTab.TypeIndex; allowOpen: BOOLEAN>
+ 1333      = TypeIdent<t> [ Subrange<t> ]     (* anchored subrange: T[lo..hi] *)
+ 1334      | Subrange<t>
+ 1335      | Enum<t>
+ 1336      | ArrayType<t, allowOpen>
+ 1337      | SetType<t>
+ 1338      | PackSetType<t>
+ 1339      | RecordType<t>
+ 1340      | PointerType<t>
+ 1341      | ProcType<t> .
+ 1342    PointerType<VAR t: SymTab.TypeIndex>  (. VAR base: SymTab.TypeIndex; .)
+ 1343      = "POINTER" "TO"                    (. allowFwdType := TRUE; .)
+ 1344        Type<base, FALSE>                 (. allowFwdType := FALSE;
+ 1345                                             t := SymTab.NewPtr(base); .) .
+ 1346    (* Procedure types (step 8.5): PROCEDURE (params): result. Values
+ 1347       are code pointers; params are collected into the descriptor. *)
+ 1348    ProcType<VAR t: SymTab.TypeIndex>     (. VAR res, pt: SymTab.TypeIndex;
+ 1349                                               isV: BOOLEAN; .)
+ 1350      = ( "PROCEDURE" | "PROC" )         (. allowFwdType := FALSE;
+ 1351                                             res := SymTab.InvalidType;
+ 1352                                             t := SymTab.NewProcType(res); .)
+ 1353        [ "(" [ ProcTypeSection<t>
+ 1354                 { (";" | ",") ProcTypeSection<t> } ] ")" ]
+ 1355        [ ":" ( TypeIdent<res>            (. SymTab.SetProcTypeRes(t, res); .)
+ 1356              | "PROC"                    (. (* PROC as a result type: the
+ 1357                                                pervasive procedure value
+ 1358                                                type (ISO/PIM) *)
+ 1359                                             SymTab.SetProcTypeRes(t,
+ 1360                                               SymTab.AddrType()); .) ) ] .
+ 1361    ProcTypeSection<t: SymTab.TypeIndex>  (. VAR pt: SymTab.TypeIndex;
+ 1362                                               isV: BOOLEAN;
+ 1363                                               cnt, k: CARDINAL;
+ 1364                                               names: ARRAY [0 .. 15] OF SymTab.Name; .)
+ 1365      =                                   (. isV := FALSE; cnt := 0; .)
+ 1366        [ "VAR"                           (. isV := TRUE; .) ]
+ 1367        ( GetIdent<names[cnt]>            (. INC(cnt); .)
+ 1368          { "," ( GetIdent<names[cnt]>    (. INC(cnt); .)
+ 1369                |                         (. (* a comma followed by a type
+ 1370                                                (possibly VAR) ends the name
+ 1371                                                list: the collected names
+ 1372                                                were types, not names *)
+ 1373                                             k := 0;
+ 1374                                             WHILE k < cnt DO
+ 1375                                               SymTab.ProcTypeAdd(t, isV,
+ 1376                                                 SymTab.SymType(names[k]));
+ 1377                                               INC(k)
+ 1378                                             END;
+ 1379                                             cnt := 0; .)
+ 1380                  [ "VAR"                 (. isV := TRUE; .) ]
+ 1381                  Type<pt, TRUE>          (. SymTab.ProcTypeAdd(t, isV, pt); .) ) }
+ 1382          ( ":" Type<pt, TRUE>            (. k := 0;
+ 1383                                             WHILE k < cnt DO
+ 1384                                               SymTab.ProcTypeAdd(t, isV, pt);
+ 1385                                               INC(k)
+ 1386                                             END; .)
+ 1387          |                               (. (* type-only parameter list:
+ 1388                                                each collected name is a
+ 1389                                                type (CHAR, a declared type,
+ 1390                                                ... or the GNU shorthand) *)
+ 1391                                             k := 0;
+ 1392                                             WHILE k < cnt DO
+ 1393                                               IF IsTypeName(names[k]) THEN
+ 1394                                                 pt := SymTab.SymType(names[k])
+ 1395                                               ELSE SemError(201);
+ 1396                                                 pt := SymTab.InvalidType
+ 1397                                               END;
+ 1398                                               SymTab.ProcTypeAdd(t, isV, pt);
+ 1399                                               INC(k)
+ 1400                                             END; .) )
+ 1401        | Type<pt, TRUE>                 (. (* unnamed parameter (PIM):
+ 1402                                                e.g. PROCEDURE (VAR ARRAY OF REAL) *)
+ 1403                                             SymTab.ProcTypeAdd(t, isV, pt); .) ) .
+ 1404    (* Arrays: "OF" without bounds is an open formal (allowed only
+ 1405       where allowOpen); "[lo..hi, ...]" nests bounded levels inside
+ 1406       out.  The PIM/ISO multi-index form repeats the bracket group
+ 1407       ("ARRAY [lo..hi], [lo..hi] OF T"); the bounds of every group
+ 1408       nest in the same inside-out order as the comma list.  Bounds are
+ 1409       folded literals (int/char); anything else 230.  Bare-type indices
+ 1410       ("ARRAY Color OF") wait for enum ordinals. *)
+ 1411    ArrayType<VAR t: SymTab.TypeIndex; allowOpen: BOOLEAN>
+ 1412                                          (. VAR elem: SymTab.TypeIndex;
+ 1413                                               eb: SymTab.Name;
+ 1414                                               ok: BOOLEAN;
+ 1415                                               bnds, bndh: ARRAY [0 .. 7] OF INTEGER;
+ 1416                                               nb, k: CARDINAL;
+ 1417                                               idx: SymTab.TypeIndex;
+ 1418                                               ilo, ihi: INTEGER; .)
+ 1419      = "ARRAY"                           (. allowFwdType := FALSE; .)
+ 1420        ( "OF"
+ 1421          Type<elem, FALSE>               (. LexName(eb); (* the element ident *)
+ 1422                                             IF NOT allowOpen THEN
+ 1423                                               SemError(230) END;
+ 1424                                             t := SymTab.NewOpenArray(elem);
+ 1425                                             IF SymTab.Equal(eb, "BYTE") THEN
+ 1426                                               SymTab.MarkByteBuf(t) END; .)
+ 1427        | TypeIdent<idx> [ Subrange<idx> ]
+ 1428          "OF" Type<elem, FALSE>          (. (* index-type array: the index
+ 1429                                                type's ordinal bounds give the
+ 1430                                                [lo..hi] pair *)
+ 1431                                             IF SymTab.TypeBounds(idx, ilo,
+ 1432                                                ihi)
+ 1433                                             THEN t := SymTab.NewArrayB(elem,
+ 1434                                                    ilo, ihi)
+ 1435                                             ELSE SemError(230);
+ 1436                                               t := SymTab.InvalidType
+ 1437                                             END; .)
+ 1438        | "["                             (. SymTab.BoundBegin; ok := TRUE;
+ 1439                                             nb := 0; .)
+ 1440          BoundPair<ok>
+ 1441          { "," BoundPair<ok> }
+ 1442          "]"                             (. (* snapshot this bracket group
+ 1443                                                before the element type, which
+ 1444                                                reuses the bound buffer for a
+ 1445                                                nested ARRAY *)
+ 1446                                             IF nb + SymTab.BoundCount() >
+ 1447                                                HIGH(bnds) + 1 THEN
+ 1448                                               SemError(230); ok := FALSE
+ 1449                                             ELSE
+ 1450                                               k := 0;
+ 1451                                               WHILE k < SymTab.BoundCount() DO
+ 1452                                                 bnds[nb] := SymTab.BoundLo(k);
+ 1453                                                 bndh[nb] := SymTab.BoundHi(k);
+ 1454                                                 INC(k); INC(nb)
+ 1455                                               END
+ 1456                                             END; .)
+ 1457          { "," "["                       (. SymTab.BoundBegin; .)
+ 1458            BoundPair<ok>
+ 1459            { "," BoundPair<ok> }
+ 1460            "]"                           (. IF nb + SymTab.BoundCount() >
+ 1461                                                HIGH(bnds) + 1 THEN
+ 1462                                               SemError(230); ok := FALSE
+ 1463                                             ELSE
+ 1464                                               k := 0;
+ 1465                                               WHILE k < SymTab.BoundCount() DO
+ 1466                                                 bnds[nb] := SymTab.BoundLo(k);
+ 1467                                                 bndh[nb] := SymTab.BoundHi(k);
+ 1468                                                 INC(k); INC(nb)
+ 1469                                               END
+ 1470                                             END; .) }
+ 1471          "OF" Type<elem, FALSE>
+ 1472                                          (. IF ok THEN
+ 1473                                               k := nb;
+ 1474                                               WHILE k > 0 DO
+ 1475                                                 DEC(k);
+ 1476                                                 elem := SymTab.NewArrayB(
+ 1477                                                   elem, bnds[k], bndh[k])
+ 1478                                               END;
+ 1479                                               t := elem
+ 1480                                             ELSE t := SymTab.InvalidType
+ 1481                                             END; .) ) .
+ 1482    BoundPair<VAR ok: BOOLEAN>            (. VAR tlo, thi: SymTab.TypeIndex;
+ 1483                                               qlo, qhi: QbeGen.QVal;
+ 1484                                               lo, hi: INTEGER;
+ 1485                                               cl, cl2: INTEGER; .)
+ 1486      = Expr<tlo, qlo> ".." Expr<thi, qhi>
+ 1487                                          (. IF (tlo = SymTab.InvalidType)
+ 1488                                              OR (thi = SymTab.InvalidType) THEN
+ 1489                                             ok := FALSE
+ 1490                                           ELSE cl := SymTab.ClassOf(tlo);
+ 1491                                             cl2 := SymTab.ClassOf(thi);
+ 1492                                             IF ((cl # SymTab.ClInt)
+ 1493   AND (cl # SymTab.ClChar)
+ 1494   AND (cl # SymTab.ClBool)
+ 1495   AND (cl # SymTab.ClEnum)
+ 1496   AND (cl # SymTab.ClByte)
+ 1497   AND (cl # SymTab.ClSByte)
+ 1498   AND (cl # SymTab.ClWord16)
+ 1499   AND (cl # SymTab.ClSWord16))
+ 1500                                                OR ((cl2 # SymTab.ClInt)
+ 1501   AND (cl2 # SymTab.ClChar)
+ 1502   AND (cl2 # SymTab.ClBool)
+ 1503   AND (cl2 # SymTab.ClEnum)
+ 1504   AND (cl2 # SymTab.ClByte)
+ 1505   AND (cl2 # SymTab.ClSByte)
+ 1506   AND (cl2 # SymTab.ClWord16)
+ 1507   AND (cl2 # SymTab.ClSWord16)) THEN
+ 1508                                               SemError(230); ok := FALSE
+ 1509                                             ELSIF NOT SymTab.ConstInt(qlo, lo)
+ 1510                                                OR NOT SymTab.ConstInt(qhi, hi)
+ 1511                                                OR (lo > hi) THEN
+ 1512                                               SemError(230); ok := FALSE
+ 1513                                              ELSIF NOT SymTab.BoundAdd(lo, hi) THEN
+ 1514                                                SemError(230); ok := FALSE
+ 1515                                              END;
+ 1516                                            END; .) .
+ 1517    (* Sets: multi-word masks over bases ≤ 256 values (bool, char,
+ 1518       bounded subranges; enums wait for ordinals, INTEGER is
+ 1519       unbounded). Literals are SET OF [0..255]; assignment and
+ 1520       comparison across suitable bases are lenient (masks over min
+ 1521       words + zero-check extras), out-of-span literals are 222. *)
+ 1522    SetType<VAR t: SymTab.TypeIndex>      (. VAR base: SymTab.TypeIndex;
+ 1523                                               blo, bhi, bspan: INTEGER;
+ 1524                                               bcls: INTEGER; .)
+ 1525      = "SET"                             (. allowFwdType := FALSE; .)
+ 1526        "OF" Type<base, FALSE>
+ 1527                                          (. IF base = SymTab.InvalidType THEN
+ 1528                                               t := SymTab.InvalidType
+ 1529                                             ELSIF SymTab.Unresolved(base) THEN
+ 1530                                               (* an opaque/formal base: defer
+ 1531                                                  the span check until the
+ 1532                                                  base is completed *)
+ 1533                                               t := SymTab.NewSet(base)
+ 1534                                             ELSE bcls :=
+ 1535                                                    SymTab.ClassOf(base);
+ 1536                                               (* a subrange keeps its own
+ 1537                                                  span even when its base is
+ 1538                                                  CHAR/BOOLEAN/an enum *)
+ 1539                                               IF SymTab.SubBounds(base,
+ 1540                                                       blo, bhi) THEN
+ 1541                                                 bspan := bhi - blo + 1
+ 1542                                               ELSIF bcls = SymTab.ClBool THEN
+ 1543                                                 blo := 0; bspan := 2
+ 1544                                               ELSIF bcls = SymTab.ClChar THEN
+ 1545                                                 blo := 0; bspan := 256
+ 1546                                               ELSIF bcls = SymTab.ClByte THEN
+ 1547                                                 blo := 0; bspan := 256
+ 1548                                               ELSIF bcls = SymTab.ClSByte THEN
+ 1549                                                 blo := -128; bspan := 256
+ 1550                                               ELSIF bcls = SymTab.ClWord16 THEN
+ 1551                                                 blo := 0; bspan := 65536
+ 1552                                               ELSIF bcls = SymTab.ClSWord16 THEN
+ 1553                                                 blo := -32768; bspan := 65536
+ 1554                                               ELSIF bcls = SymTab.ClEnum THEN
+ 1555                                                 blo := 0;
+ 1556                                                 bspan := VAL(INTEGER,
+ 1557                                                   SymTab.EnumCount(base))
+ 1558                                               ELSE bspan := 0 END;
+ 1559                                               IF (bspan <= 0)
+ 1560                                                  OR (bspan > 65536) THEN
+ 1561                                                 SemError(230);
+ 1562                                                 t := SymTab.InvalidType
+ 1563                                               ELSE t := SymTab.NewSet(base)
+ 1564                                               END
+ 1565                                             END; .) .
+ 1566    (* PACKEDSET: same base rules as SET, but 1/2/4-byte storage.  V3
+ 1567       limits the span to 32 bits (SetBytes 1..4); wider packed sets are
+ 1568       an implementation limit (230). *)
+ 1569    PackSetType<VAR t: SymTab.TypeIndex>  (. VAR base: SymTab.TypeIndex;
+ 1570                                               blo, bhi, bspan: INTEGER;
+ 1571                                               bcls: INTEGER; .)
+ 1572      = "PACKEDSET"                       (. allowFwdType := FALSE; .)
+ 1573        "OF" Type<base, FALSE>
+ 1574                                          (. IF base = SymTab.InvalidType THEN
+ 1575                                               t := SymTab.InvalidType
+ 1576                                             ELSIF SymTab.Unresolved(base) THEN
+ 1577                                               t := SymTab.NewPackSet(base)
+ 1578                                             ELSE bcls :=
+ 1579                                                    SymTab.ClassOf(base);
+ 1580                                               IF SymTab.SubBounds(base,
+ 1581                                                       blo, bhi) THEN
+ 1582                                                 bspan := bhi - blo + 1
+ 1583                                               ELSIF bcls = SymTab.ClBool THEN
+ 1584                                                 blo := 0; bspan := 2
+ 1585                                               ELSIF bcls = SymTab.ClChar THEN
+ 1586                                                 blo := 0; bspan := 256
+ 1587                                               ELSIF bcls = SymTab.ClByte THEN
+ 1588                                                 blo := 0; bspan := 256
+ 1589                                               ELSIF bcls = SymTab.ClSByte THEN
+ 1590                                                 blo := -128; bspan := 256
+ 1591                                               ELSIF bcls = SymTab.ClWord16 THEN
+ 1592                                                 blo := 0; bspan := 65536
+ 1593                                               ELSIF bcls = SymTab.ClSWord16 THEN
+ 1594                                                 blo := -32768; bspan := 65536
+ 1595                                               ELSIF bcls = SymTab.ClEnum THEN
+ 1596                                                 blo := 0;
+ 1597                                                 bspan := VAL(INTEGER,
+ 1598                                                   SymTab.EnumCount(base))
+ 1599                                               ELSE bspan := 0 END;
+ 1600                                               IF (bspan <= 0)
+ 1601                                                  OR (bspan > 32) THEN
+ 1602                                                 SemError(230);
+ 1603                                                 t := SymTab.InvalidType
+ 1604                                               ELSE t := SymTab.NewPackSet(base)
+ 1605                                               END
+ 1606                                             END; .) .
+ 1607    (* Records: flat blobs; array fields are pointers to static
+ 1608       descriptors (locked amendment), nested records inline. Field
+ 1609       offsets static and declaration-ordered. *)
+ 1610    (* Field list: plain fields and (optionally) one variant part.  The
+ 1611       variant part is a `CASE ... END` item; because it starts with the
+ 1612       CASE keyword it is unambiguously distinguishable from a field
+ 1613       (which starts with an identifier). *)
+ 1614    RecordType<VAR t: SymTab.TypeIndex>   (. VAR t2: SymTab.TypeIndex;
+ 1615                                               tagOk: BOOLEAN; .)
+ 1616      = "RECORD"                          (. allowFwdType := FALSE;
+ 1617                                             t := SymTab.NewRecord(); .)
+ 1618        [ RecItem<t> { ";" [ RecItem<t> ] } ]
+ 1619        "END"                             (. SymTab.LayoutRecord(t); .) .
+ 1620    RecItem<rec: SymTab.TypeIndex>        (. VAR tt: SymTab.TypeIndex; .)
+ 1621      = RecField<rec>
+ 1622      | CaseField<rec>                    (. SymTab.MarkVariant(rec); .) .
+ 1623    (* A variant part: CASE [tag] : Type OF variants.  gm2 extensions:
+ 1624       an untagged inner CASE (no tag field), empty arms and ELSE arms. *)
+ 1625    CaseField<rec: SymTab.TypeIndex>      (. VAR tagT: SymTab.TypeIndex;
+ 1626                                               tagN: SymTab.Name;
+ 1627                                               tagged: BOOLEAN; .)
+ 1628      = "CASE"                            (. SymTab.ResetFields(rec);
+ 1629                                             tagged := FALSE; .)
+ 1630        [ GetIdent<tagN>                  (. IF NOT SymTab.FieldPending(rec,
+ 1631                                               tagN) THEN
+ 1632                                               SemError(200) END;
+ 1633                                             tagged := TRUE; .) ]
+ 1634        ":" Type<tagT, FALSE>             (. IF (tagT # SymTab.InvalidType)
+ 1635    AND NOT SymTab.IsOrdinal(tagT) THEN
+ 1636                                               SemError(224)
+ 1637                                             END;
+ 1638                                             IF tagged THEN
+ 1639                                               SymTab.FixPendingF(rec, tagT);
+ 1640                                               SymTab.SetVariantTag(rec, tagN)
+ 1641                                             END; .)
+ 1642        "OF"
+ 1643        RecFieldList<rec>
+ 1644        { "|"                             (. SymTab.ResetFields(rec); .)
+ 1645          RecFieldList<rec> }
+ 1646        [ "ELSE" ]
+ 1647        "END" .
+ 1648    (* A variant branch: `labels : fields` (fields and their trailing ";"
+ 1649       optional, gm2), `ELSE`, or empty (the extra "|" separators gm2
+ 1650       tolerates).  A branch may itself contain a nested variant CASE. *)
+ 1651    RecFieldList<rec: SymTab.TypeIndex>   (. VAR lt, lq: SymTab.TypeIndex;
+ 1652                                               lv1, lv2: QbeGen.QVal; .)
+ 1653      = [ ( VarLabel<lt, lv1> [ ".." VarLabel<lq, lv2> ]
+ 1654            { "," VarLabel<lt, lv1> [ ".." VarLabel<lq, lv2> ] }
+ 1655            ":"
+ 1656            [ ArmField<rec> { ";" [ ArmField<rec> ] } ]
+ 1657          | "ELSE" ) ] .
+ 1658    ArmField<rec: SymTab.TypeIndex>
+ 1659      = RecField<rec>
+ 1660      | CaseField<rec>                    (. SymTab.MarkVariant(rec); .) .
+ 1661    (* Variant case label: a constant (or a constant range).  Values are
+ 1662       not interpreted (the layout overlays regardless). *)
+ 1663    VarLabel<VAR t: SymTab.TypeIndex; VAR q: QbeGen.QVal>
+ 1664                                          (. VAR lname: SymTab.Name; .)
+ 1665      = ( ident                         (. LexName(lname);
+ 1666                                             QbeGen.CopyOp("0", q);
+ 1667                                             t := SymTab.IntType(); .)
+ 1668        | integer                       (. LexString(lname);
+ 1669                                             QbeGen.CopyOp("0", q);
+ 1670                                             t := SymTab.IntType(); .)
+ 1671        | charConst                     (. LexString(lname);
+ 1672                                             QbeGen.CopyOp("0", q);
+ 1673                                             t := SymTab.CharType(); .) ) .
+ 1674    RecField<rec: SymTab.TypeIndex>       (. VAR n: SymTab.Name;
+ 1675                                               t2: SymTab.TypeIndex; .)
+ 1676      = RecIdents<rec> ":" Type<t2, FALSE>(. SymTab.FixPendingF(rec, t2); .) .
+ 1677    RecIdents<rec: SymTab.TypeIndex>      (. VAR n: SymTab.Name; .)
+ 1678      = GetIdent<n>                       (. IF NOT SymTab.FieldPending(rec,
+ 1679                                               n) THEN
+ 1680                                               SemError(200) END; .)
+ 1681        { "," GetIdent<n>                 (. IF NOT SymTab.FieldPending(rec,
+ 1682                                               n) THEN
+ 1683                                               SemError(200) END; .) } .
+ 1684    TypeIdent<VAR t: SymTab.TypeIndex>    (. VAR n, qid: SymTab.Name;
+ 1685                                               k: INTEGER;
+ 1686                                               dotted: BOOLEAN; .)
+ 1687      = GetIdent<n>                       (. dotted := FALSE;
+ 1688                                             IF NOT SymTab.Lookup(n) THEN
+ 1689                                               (* declaration before use: an
+ 1690                                                  undeclared type is 201,
+ 1691                                                  except as a POINTER's base
+ 1692                                                  (allowFwdType) *)
+ 1693                                               k := -1;
+ 1694                                               IF allowFwdType THEN
+ 1695                                                 t := SymTab.ForwardType(n)
+ 1696                                               ELSE t := SymTab.InvalidType
+ 1697                                               END;
+ 1698                                               IF t = SymTab.InvalidType THEN
+ 1699                                                 SemError(201)
+ 1700                                               END
+ 1701                                             ELSE k := SymTab.SymKind(n);
+ 1702                                               IF (k = SymTab.KindType)
+ 1703                                                  OR (k = SymTab.KindPredef) THEN
+ 1704                                                 t := SymTab.SymType(n)
+ 1705                                               ELSE t := SymTab.InvalidType
+ 1706                                               END
+ 1707                                             END; .)
+ 1708        [ "." GetIdent<qid>               (. dotted := TRUE;
+ 1709                                             IF k = SymTab.KindModule THEN
+ 1710                                               t := SymTab.QualType(n, qid);
+ 1711                                               IF t = SymTab.InvalidType THEN
+ 1712                                                 SemError(201)
+ 1713                                               END
+ 1714                                             ELSE SemError(221);
+ 1715                                               t := SymTab.InvalidType
+ 1716                                             END; .) ]
+ 1717                                          (. IF NOT dotted THEN
+ 1718                                               IF (k = SymTab.KindModule)
+ 1719                                                  OR ((k # SymTab.KindType)
+ 1720    AND (k # SymTab.KindPredef)
+ 1721    AND (k # SymTab.KindImport)
+ 1722    AND (k # -1)) THEN
+ 1723                                                 SemError(221)
+ 1724                                               END
+ 1725                                             END; .) .
+ 1726    Subrange<VAR t: SymTab.TypeIndex>     (. VAR tlo, thi: SymTab.TypeIndex;
+ 1727                                               qlo, qhi: QbeGen.QVal;
+ 1728                                               lo, hi: INTEGER; .)
+ 1729      = "[" Expr<tlo, qlo> ".." Expr<thi, qhi>
+ 1730                                          (. IF (tlo = SymTab.InvalidType)
+ 1731                                              OR (thi = SymTab.InvalidType) THEN
+ 1732                                             t := SymTab.InvalidType
+ 1733                                           ELSIF NOT SymTab.IsOrdinal(tlo)
+ 1734                                              OR NOT SymTab.IsOrdinal(thi) THEN
+ 1735                                             SemError(230);
+ 1736                                             t := SymTab.InvalidType
+ 1737                                           ELSIF NOT SymTab.ConstInt(qlo, lo)
+ 1738                                              OR NOT SymTab.ConstInt(qhi, hi)
+ 1739                                              OR (lo > hi) THEN
+ 1740                                             SemError(230);
+ 1741                                             t := SymTab.InvalidType
+ 1742                                           ELSE IF SymTab.SameType(tlo, thi) THEN
+ 1743                                             (* keep the base type: ['A'..'Z']
+ 1744                                                is character, [red..blue]
+ 1745                                                that enumeration *)
+ 1746                                             t := SymTab.NewSubB(lo, hi, tlo)
+ 1747                                           ELSE t := SymTab.NewSubR(lo, hi)
+ 1748                                           END
+ 1749                                           END; .)
+ 1750        "]" .
+ 1751    Enum<VAR t: SymTab.TypeIndex>         (. VAR n: SymTab.Name;
+ 1752                                               ord: INTEGER;
+ 1753                                               qv: QbeGen.QVal; .)
+ 1754      = "("                               (. t := SymTab.NewEnum();
+ 1755                                             ord := 0; .)
+ 1756        GetIdent<n>                       (. IF NOT SymTab.Enter(n,
+ 1757                                               SymTab.KindConst) THEN
+ 1758                                               SemError(200) END;
+ 1759                                             SymTab.SetSymType(n, t);
+ 1760                                             QbeGen.IntStr(ord, qv);
+ 1761                                             SymTab.SetSymVal(n, qv);
+ 1762                                             SymTab.NoteEnumLit(t, n);
+ 1763                                             Lower.NoteVar(n,
+ 1764                                               SymTab.KindConst, t);
+ 1765                                             Lower.NoteConstVal(qv);
+ 1766                                             INC(ord); .)
+ 1767        { "," GetIdent<n>                 (. IF NOT SymTab.Enter(n,
+ 1768                                               SymTab.KindConst) THEN
+ 1769                                               SemError(200) END;
+ 1770                                             SymTab.SetSymType(n, t);
+ 1771                                             QbeGen.IntStr(ord, qv);
+ 1772                                             SymTab.SetSymVal(n, qv);
+ 1773                                             SymTab.NoteEnumLit(t, n);
+ 1774                                             Lower.NoteVar(n,
+ 1775                                               SymTab.KindConst, t);
+ 1776                                             Lower.NoteConstVal(qv);
+ 1777                                             INC(ord); .) }
+ 1778        ")"                               (. SymTab.SetEnumCount(t,
+ 1779                                               VAL(CARDINAL, ord)); .) .
+ 1780    (* Clarion-form classes (docs/OOP.txt): declaration + single
+ 1781       inheritance + IMPLEMENTATION blocks. Scopes and member checks
+ 1782       now; lowering (vtable, dispatch, THIS) later — one 230 per
+ 1783       class/impl block. Methods end with ";" per the Table example
+ 1784       (not "," as in the sketch). No underscores in identifiers. *)
+ 1785    (* Single CLASS item in both loops: separating declaration from
+ 1786       IMPLEMENTATION at the loop level needs 2-token lookahead
+ 1787       (CLASS ident vs CLASS IMPLEMENTATION), which LL(1) cannot do.
+ 1788       The second token decides after CLASS is consumed. A misplaced
+ 1789       CLASS IMPLEMENTATION inside TYPE still parses (harmless: the
+ 1790       whole unit ends 230 until lowering). *)
+ 1791    ClassItem
+ 1792      = "CLASS" ( "IMPLEMENTATION" ClassImplRest | ClassRest ) .
+ 1793    ClassRest                             (. VAR cn, m2, pn: SymTab.Name;
+ 1794                                               ct: SymTab.TypeIndex; .)
+ 1795      = GetIdent<cn>                      (. IF NOT SymTab.Enter(cn,
+ 1796                                               SymTab.KindType) THEN
  1797                                               SemError(200) END;
- 1798                                             astNode := AST.MakeNode(AST.NkVarDecl);
- 1799                                             AST.SetChild(astNode, 0,
- 1800                                               AST.MakeLeaf(AST.NkIdent, n)); .)
- 1801          { "," GetIdent<n>               (. IF NOT SymTab.FieldPending(ct,
- 1802                                               n) THEN
- 1803                                               SemError(200) END;
- 1804                                             AST.SetChild(astNode,
- 1805                                               AST.NChild(astNode),
- 1806                                               AST.MakeLeaf(AST.NkIdent, n)); .) }
- 1807          ":" Type<t, FALSE>              (. SymTab.FixPendingF(ct, t);
- 1808                                             AST.SetTy(astNode, t);
- 1809                                             AstAppend(AST.NkFieldDecl,
- 1810                                               astClsF, astClsFTail, astNode); .) ) .
- 1811    MethodHeading<VAR pn: SymTab.Name; ct: SymTab.TypeIndex>
- 1812                                          (. VAR wantVirt: BOOLEAN; .)
- 1813      =                                   (. wantVirt := FALSE; .)
- 1814        [ "VIRTUAL"                       (. wantVirt := TRUE; .) ]
- 1815        ProcHeading<pn, ct>               (. IF wantVirt THEN
- 1816                                               SymTab.MarkVirtual END;
- 1817                                             astMethod := AST.MakeNode(AST.NkProcDecl);
- 1818                                             AST.SetChild(astMethod, 0,
- 1819                                               AST.MakeLeaf(AST.NkIdent, pn));
- 1820                                             IF wantVirt THEN
- 1821                                               AST.SetOp(astMethod, 3)
- 1822                                             ELSE AST.SetOp(astMethod, 0)
- 1823                                             END;
- 1824                                             AstAppend(AST.NkFieldDecl,
- 1825                                               astClsM, astClsMTail, astMethod); .) .
- 1826    ClassImplRest                         (. VAR cn, m2: SymTab.Name;
- 1827                                               ct: SymTab.TypeIndex; .)
- 1828      = GetIdent<cn>                      (. IF NOT SymTab.Lookup(cn) THEN
- 1829                                               SemError(201);
- 1830                                               ct := SymTab.InvalidType
- 1831                                             ELSE ct := SymTab.SymType(cn);
- 1832                                               IF SymTab.ClassOf(ct) #
- 1833                                                  SymTab.ClClass THEN
- 1834                                                 SemError(230);
- 1835                                                 ct := SymTab.InvalidType
- 1836                                               END
- 1837                                             END;
- 1838                                             astCls := AST.MakeNode(AST.NkClassDecl);
- 1839                                             AST.SetOp(astCls, 1);
- 1840                                             AST.SetChild(astCls, 0,
- 1841                                               AST.MakeLeaf(AST.NkIdent, cn));
- 1842                                             astClsM := AST.NoNode;
- 1843                                             astClsMTail := AST.NoNode;
- 1844                                             astStmt := AST.NoNode;
- 1845                                             IF ct #
- 1846                                                SymTab.InvalidType THEN
- 1847                                               IF NOT SymTab.PushClassMembers(
- 1848                                                      ct) THEN
- 1849                                                 SemError(230) END;
- 1850                                               SymTab.PushImplClass(ct)
- 1851                                             END; .)
- 1852        ";" { MethodImpl<ct> ";" }
- 1853                                          (. astStmt := AST.NoNode; .)
- 1854        [ "BEGIN"                         (. astStmt := AST.MakeNode(AST.NkBlock);
- 1855                                             .)
- 1856          [ StatSeq ] ]
- 1857        "END"
- 1858        GetIdent<m2>                      (. IF NOT SymTab.Equal(cn, m2) THEN
- 1859                                               SemError(202) END;
- 1860                                             SymTab.PopImplClass;
- 1861                                             SymTab.PopScope;
- 1862                                             AST.SetChild(astCls, 1, AST.NoNode);
- 1863                                             AST.SetChild(astCls, 2, astStmt);
- 1864                                             AST.SetChild(astCls, 3, astClsM);
- 1865                                             astDecl := astCls; .) .
- 1866    MethodImpl<ct: SymTab.TypeIndex>      (. VAR pn: SymTab.Name;
- 1867                                               thisQ: QbeGen.QVal;
- 1868                                               methRes: SymTab.TypeIndex; .)
- 1869      = MethodHeading<pn, ct> ";"
- 1870                                          (. IF (ct #
- 1871                                                SymTab.InvalidType)
- 1872   AND NOT SymTab.MethodExists(ct,
- 1873                                                    pn) THEN
- 1874                                               SemError(201) END; .)
- 1875        ( "FORWARD"                       (. AST.SetOp(astMethod, 1);
- 1876                                             SymTab.MarkFwd;
- 1877                                             QbeGen.AbortFunc;
- 1878                                             Lower.ScopeLeave;
- 1879                                             SymTab.CloseProc; .)
- 1880        |                                 (.
- 1881                                             (* bind the receiver: bare
- 1882                                                field names resolve
- 1883                                                against THIS *)
- 1884                                              QbeGen.CopyOp("@", thisQ);
- 1885                                             QbeGen.PushWith(thisQ); .)
- 1886          Block<pn>                       (. AST.SetChild(astMethod, 1, astStmt);
- 1887                                             AST.SetChild(astMethod, 2, astBlkDecls);
- 1888                                             QbeGen.PopWith;
- 1889                                             methRes := SymTab.CurRes();
- 1890                                             Lower.ScopeLeave;
- 1891                                             SymTab.CloseProc;
- 1892                                             QbeGen.EndFunc(methRes); .) ) .
- 1893    ConstBlock                            (. VAR astSeq, astTail: AST.Node; .)
- 1894      = "CONST"                           (. astSeq := AST.NoNode;
- 1895                                             astTail := AST.NoNode; .)
- 1896        { ConstDecl ";"                   (. AstAppend(AST.NkDeclSeq,
- 1897                                               astSeq, astTail, astDecl); .) }
- 1898                                          (. astDecl := astSeq; .) .
- 1899    ConstDecl                             (. VAR n: SymTab.Name;
- 1900                                               t: SymTab.TypeIndex;
- 1901                                               qv: QbeGen.QVal;
- 1902                                               cls: INTEGER;
- 1903                                               mk: ARRAY [0 .. 15] OF CARDINAL;
- 1904                                               mw: CARDINAL;
- 1905                                               mlo: INTEGER;
- 1906                                               astNode: AST.Node; .)
- 1907      = GetIdent<n>                       (. IF NOT SymTab.Enter(n,
- 1908                                               SymTab.KindConst) THEN
- 1909                                               SemError(200) END; .)
- 1910        "="
- 1911        Expr<t, qv> (. astNode := AST.MakeNode(AST.NkConstDecl);
- 1912                                             AST.SetChild(astNode, 0,
- 1913                                               AST.MakeLeaf(AST.NkIdent, n));
- 1914                                             AST.SetChild(astNode, 1, astCur);
- 1915                                             AST.SetTy(astNode, t);
- 1916                                             astDecl := astNode;
- 1917                                             Lower.NoteVar(n, SymTab.KindConst, t);
- 1918                                             Lower.NoteConstVal(qv);
- 1919                                             SymTab.SetSymType(n, t);
- 1920                                             cls := SymTab.ClassOf(t);
- 1921                                             IF cls = SymTab.ClSet THEN
- 1922                                               (* a SET CONST needs static
- 1923                                                  data: fold its mask now
- 1924                                                  (the grammar sees the
- 1925                                                  element values) and let
- 1926                                                  Lower re-emit it *)
- 1927                                               IF Lower.SetConstMaskOf(
- 1928                                                    AST.Child(astNode, 1),
- 1929                                                    mk, mw, mlo) THEN
- 1930                                                 Lower.NoteSetMask(n, mk, mw,
- 1931                                                   mlo);
- 1932                                                 SymTab.SetSymVal(n, qv)
- 1933                                               ELSE
- 1934                                                 SemError(230)
- 1935                                               END
- 1936                                             ELSIF (cls = SymTab.ClArray)
- 1937                                                OR (cls = SymTab.ClRecord)
- 1938                                                OR (cls = SymTab.ClClass)
- 1939                                                OR (cls = SymTab.ClStr)
- 1940                                                OR (cls = SymTab.ClUStr) THEN
- 1941                                               (* an aggregate/string
- 1942                                                  constant: qv is its
- 1943                                                  descriptor address; no
- 1944                                                  scalar data *)
- 1945                                               SymTab.SetSymVal(n, qv)
- 1946                                             ELSIF NOT QbeGen.IsImm(qv) THEN
- 1947                                               SemError(230)
- 1948                                             ELSE
- 1949                                               SymTab.SetSymVal(n, qv);
- 1950                                             END; .) .
- 1951    VarBlock                              (. VAR astSeq, astTail: AST.Node; .)
- 1952      = "VAR"                             (. astSeq := AST.NoNode;
- 1953                                             astTail := AST.NoNode; .)
- 1954        { VarDecl ";"                     (. AstAppend(AST.NkDeclSeq,
- 1955                                               astSeq, astTail, astDecl); .) }
- 1956                                          (. astDecl := astSeq; .) .
- 1957    VarDecl                               (. VAR nm: SymTab.Name;
- 1958                                               t: SymTab.TypeIndex;
- 1959                                               i: CARDINAL;
- 1960                                               cls: INTEGER;
- 1961                                               astNode, astTail: AST.Node; .)
- 1962      = VarIdents ":"
- 1963        Type<t, FALSE> (. astNode := AST.MakeNode(AST.NkVarDecl);
- 1964                                             astTail := astNode;
- 1965                                             i := 0;
- 1966                                             WHILE i < SymTab.PendCount() DO
- 1967                                               SymTab.PendName(i, nm);
- 1968                                               Lower.NoteVar(nm, SymTab.KindVar, t);
- 1969                                               (* chunked: a VAR list can
- 1970                                                  exceed AST.MaxChild *)
- 1971                                               AstAppend(AST.NkBlock,
- 1972                                                 astNode, astTail,
- 1973                                                 AST.MakeLeaf(AST.NkIdent, nm));
- 1974                                               INC(i)
- 1975                                             END;
- 1976                                             AST.SetTy(astNode, t);
- 1977                                             astDecl := astNode;
- 1978                                             cls := SymTab.ClassOf(t);
- 1979                                             IF (t # SymTab.InvalidType)
- 1980   AND NOT SymTab.IsUnresolved(t)
- 1981   AND (cls # SymTab.ClInt)
- 1982   AND (cls # SymTab.ClBool)
- 1983   AND (cls # SymTab.ClChar)
- 1984   AND (cls # SymTab.ClReal)
- 1985   AND (cls # SymTab.ClArray)
- 1986   AND (cls # SymTab.ClSet)
- 1987   AND (cls # SymTab.ClRecord)
- 1988   AND (cls # SymTab.ClPtr)
- 1989   AND (cls # SymTab.ClLong)
- 1990   AND (cls # SymTab.ClProc)
- 1991   AND (cls # SymTab.ClUChar)
- 1992   AND (cls # SymTab.ClUStr)
- 1993   AND (cls # SymTab.ClEnum)
- 1994   AND (cls # SymTab.ClByte)
- 1995   AND (cls # SymTab.ClSByte)
- 1996   AND (cls # SymTab.ClWord16)
- 1997   AND (cls # SymTab.ClSWord16)
- 1998   AND (cls # SymTab.ClClass) THEN
- 1999                                               SemError(230) END;
- 2000                                             IF QbeGen.LocFull() THEN
- 2001                                               SemError(233) END;
- 2002                                             i := 0;
- 2003                                             IF SymTab.IsUnresolved(t)
- 2004                                                AND NOT SymTab.InProc() THEN
- 2005                                               (* a forward-typed global:
- 2006                                                  defer emission until the
- 2007                                                  TYPE block completes *)
- 2008                                               AST.SetOp(astNode, 1);
- 2009                                               WHILE i < SymTab.PendCount() DO
- 2010                                                 SymTab.PendName(i, nm);
- 2011                                                 IF nPendVar <=
- 2012                                                    HIGH(pendVarName) THEN
- 2013                                                   pendVarName[nPendVar] := nm;
- 2014                                                   pendVarT[nPendVar] := t;
- 2015                                                   INC(nPendVar)
- 2016                                                 END;
- 2017                                                 INC(i)
- 2018                                               END
- 2019                                             ELSE
- 2020                                               WHILE i < SymTab.PendCount() DO
- 2021                                                 SymTab.PendName(i, nm);
- 2022                                                 INC(i)
- 2023                                               END
- 2024                                             END;
- 2025                                             (* a plain VAR list, not a
- 2026                                                heading: the signature
- 2027                                                result is discarded *)
- 2028                                             IF NOT SymTab.FixPending(t) THEN
- 2029                                             END; .) .
- 2030    VarIdents                             (. VAR n: SymTab.Name; .)
- 2031      = GetIdent<n>                       (. IF NOT SymTab.EnterPending(n,
- 2032                                               SymTab.KindVar) THEN
- 2033                                               SemError(200) END; .)
- 2034        { ","
- 2035          GetIdent<n>                     (. IF NOT SymTab.EnterPending(n,
- 2036                                               SymTab.KindVar) THEN
- 2037                                               SemError(200) END; .) } .
- 2038    ParIdents<isV: BOOLEAN>               (. VAR n: SymTab.Name; .)
- 2039      = GetIdent<n>                       (. IF NOT SymTab.EnterParam(n, isV) THEN
- 2040                                               SemError(200) END; .)
- 2041        { "," GetIdent<n>                 (. IF NOT SymTab.EnterParam(n, isV) THEN
- 2042                                               SemError(200) END; .) } .
- 2043    (* Procedure headings enter scopes/params/result and buffer the
- 2044       QBE header; bodies lower to functions (4.1, module level only).
- 2045       FORWARD marks; the body heading re-enters (signature compare
- 2046       deferred). Nested procedures parse + check, lowering = 4.2. *)
- 2047    (* gm2 declaration pragmas: __BUILTIN__ (definition module) and
- 2048       __ATTRIBUTE__ __BUILTIN__ (( name )) (implementation).  They
- 2049       annotate C built-ins; V3 parses and ignores them. *)
- 2050    ProcPragma
- 2051      = "__BUILTIN__"
- 2052      | "__ATTRIBUTE__" [ "__BUILTIN__" ] [ "(" "(" ident ")" ")" ] .
- 2053  
- 2054    ProcHeading<VAR pn: SymTab.Name; methCls: SymTab.TypeIndex>
- 2055                                          (. VAR t: SymTab.TypeIndex;
- 2056                                               mg: QbeGen.QVal; .)
- 2057      = "PROCEDURE"
- 2058        [ ProcPragma ]
- 2059        GetIdent<pn>                      (. IF methCls #
- 2060                                                SymTab.InvalidType THEN
- 2061                                             (* a method: resume the
- 2062                                                declared symbol (reuse
- 2063                                                its uid) *)
- 2064                                             IF NOT SymTab.ResumeMethod(
- 2065                                                  methCls, pn) THEN
- 2066                                               SemError(200) END
- 2067                                             ELSIF NOT SymTab.EnterProc(pn) THEN
- 2068                                             IF NOT SymTab.ReenterProc(pn) THEN
- 2069                                               IF NOT SymTab.ResumeProc(pn) THEN
- 2070                                                 SemError(200) END
- 2071                                               END
- 2072                                             END;
- 2073                                             Lower.ScopeEnter;
- 2074                                             Lower.NoteProc(pn,
- 2075                                               SymTab.ProcUid(pn),
- 2076                                               SymTab.InvalidType,
- 2077                                               SymTab.ProcDepthOf(pn),
- 2078                                               FALSE);
- 2079                                             QbeGen.BeginFunc("");
- 2080                                             IF methCls #
- 2081                                                SymTab.InvalidType THEN
- 2082                                               (* hidden THIS receiver:
- 2083                                                  a VAR param of the
- 2084                                                  class type, pushed as
- 2085                                                  the WITH base *)
- 2086                                               IF NOT SymTab.EnterThisParam(
- 2087                                                    methCls) THEN
- 2088                                                 SemError(200) END;
- 2089                                               IF NOT QbeGen.FuncParam(
- 2090                                                    "THIS", TRUE,
- 2091                                                    methCls) THEN
- 2092                                                 SemError(233) END
- 2093                                             END; .)
- 2094        [ FormalParams ]
- 2095        [ ":" ( TypeIdent<t>              (. IF NOT SymTab.SetProcRes(t) THEN
- 2096                                               SemError(235) END;
- 2097                                             Lower.SetProcRes(t); .)
- 2098              | "PROC"                    (. (* PROC result: the procedure
- 2099                                                value type *)
- 2100                                             IF NOT SymTab.SetProcRes(
- 2101                                                SymTab.AddrType()) THEN
- 2102                                               SemError(235) END;
- 2103                                             Lower.SetProcRes(
- 2104                                               SymTab.AddrType()); .) ) ] .
- 2105    FormalParams
- 2106      = "(" [ ParamSection { ";" ParamSection } ] ")" .
- 2107    ParamSection                          (. VAR t: SymTab.TypeIndex;
- 2108                                               nm: SymTab.Name;
- 2109                                               i: CARDINAL;
- 2110                                               isV: BOOLEAN; .)
- 2111      =                                   (. isV := FALSE; .)
- 2112        [ "VAR"                           (. isV := TRUE; .) ]
- 2113        ParIdents<isV> ":" Type<t, TRUE>  (. i := 0;
- 2114                                             WHILE i < SymTab.PendCount() DO
- 2115                                               SymTab.PendName(i, nm);
- 2116                                               Lower.NoteParam(nm, t, isV);
- 2117                                               Lower.NoteVar(nm, SymTab.KindParam, t);
- 2118                                               (* value open arrays are
- 2119                                                  passed as descriptor
- 2120                                                  addresses (no copy):
- 2121                                                  same representation as
- 2122                                                  VAR formals *)
- 2123                                               IF NOT QbeGen.FuncParam(nm,
- 2124                                                    isV
- 2125                                                    OR SymTab.IsOpenArray(t),
- 2126                                                    t) THEN
- 2127                                                 SemError(233) END;
- 2128                                               INC(i)
- 2129                                             END;
- 2130                                             IF NOT SymTab.FixPending(t) THEN
- 2131                                               SemError(235) END; .) .
- 2132    (* Nested procedures lower like top-level ones (4.2): the
- 2133       static link gives them their parent's frame. Methods keep
- 2134       parse-now/230-later. *)
- 2135    ProcDecl                              (. VAR pn: SymTab.Name;
- 2136                                               saveFun: SymTab.Name;
- 2137                                               astNode: AST.Node; .)
- 2138      = ProcHeading<pn, SymTab.InvalidType> ";"
- 2139                                          (. astNode := AST.MakeNode(AST.NkProcDecl);
- 2140                                             AST.SetOp(astNode, 0);
- 2141                                             AST.SetChild(astNode, 0,
- 2142                                               AST.MakeLeaf(AST.NkIdent, pn));
- 2143                                             Lower.NoteProcNode(astNode); .)
- 2144        ( "FORWARD"                       (. AST.SetOp(astNode, 1);
- 2145                                             astDecl := astNode;
- 2146                                             Lower.ScopeLeave;
- 2147                                             SymTab.MarkFwd;
- 2148                                             SymTab.CloseProc;
- 2149                                             QbeGen.AbortFunc; .)
- 2150        | "EXTERNAL"                      (. AST.SetOp(astNode, 2);
- 2151                                             astDecl := astNode;
- 2152                                             Lower.MarkProcExternal;
- 2153                                             Lower.ScopeLeave;
- 2154                                             SymTab.MarkExternal("");
- 2155                                             SymTab.CloseProc;
- 2156                                             QbeGen.AbortFunc; .)
- 2157        |                                 
- 2158          (. allowDefer := TRUE; deferredBody := FALSE;
- 2159                                             curProcNode := astNode;
- 2160                                             saveFun := curFun;
- 2161                                             curFun := pn; .)
- 2162          Block<pn>                       (. curFun := saveFun;
- 2163                                             IF deferredBody THEN
- 2164                                               (* body skipped: close like
- 2165                                                  FORWARD (no body node) *)
- 2166                                               astDecl := astNode;
- 2167                                               Lower.ScopeLeave;
- 2168                                               SymTab.CloseProc;
- 2169                                               QbeGen.AbortFunc
- 2170                                             ELSE
- 2171                                               AST.SetChild(astNode, 1, astStmt);
- 2172                                               AST.SetChild(astNode, 2, astBlkDecls);
- 2173                                               astDecl := astNode;
- 2174                                               Lower.ScopeLeave;
- 2175                                               SymTab.CloseProc;
- 2176                                               QbeGen.EndFunc(
- 2177                                                 SymTab.ProcRes(pn))
- 2178                                             END; .) ) .
- 2179    Block<pn: SymTab.Name>                (. VAR m2: SymTab.Name; dfr: BOOLEAN; .)
- 2180      =                                   (. dfr := FALSE;
- 2181                                             IF allowDefer AND twoPhaseParse
- 2182                                                AND NOT repassing THEN
- 2183                                               dfr := DeferSkip(pn)
- 2184                                             END;
- 2185                                             allowDefer := FALSE;
- 2186                                             .)
- 2187        DeclSeq                           (. astBlkDecls := astDecl;
- 2188                                             astStmt := AST.NoNode;
- 2189                                             nLab := 0; nGot := 0; .)
- 2190        [ "BEGIN"                         (. (* an empty body is still a
- 2191                                               body: mark it so Lower
- 2192                                               does not read it as a
- 2193                                               definition heading *)
- 2194                                             IF NOT dfr THEN
- 2195                                               IF astStmt = AST.NoNode THEN
- 2196                                                 astStmt :=
- 2197                                                   AST.MakeNode(AST.NkBlock)
- 2198                                               END
- 2199                                             END; .)
- 2200          [ StatSeq ] ]
- 2201        "END"
- 2202        GetIdent<m2>                      (. IF NOT SymTab.Equal(pn, m2) THEN
- 2203                                               SemError(202) END;
- 2204                                             CheckGotos; .) .
- 2205    (* Two-phase, phase 2 (milestone 2c): re-parse every deferred module-
- 2206       level body once the unit's declarations are complete.  Inlined at
- 2207       both call sites because a stand-alone epsilon production is
- 2208       "unreachable" to Coco/R (referenced only from actions). *)
- 2209    StatSeq                               (. VAR astSeq, astTail: AST.Node; .)
- 2210      =                                   (. astSeq := AST.NoNode;
- 2211                                             astTail := AST.NoNode; .)
- 2212        Statement                         (. AstAppend(AST.NkBlock,
- 2213                                               astSeq, astTail, astStmt); .)
- 2214        { ";" [ Statement                 (. AstAppend(AST.NkBlock,
- 2215                                               astSeq, astTail, astStmt); .) ] }
- 2216                                          (. astStmt := astSeq; .) .
- 2217    (* Trailing/empty statements (`a; ; b`, Coco/R's generated `;;`)
- 2218       are accepted: the statement after ';' is optional. *)
- 2219    Statement                             (. VAR lx: QbeGen.QVal; lxnm: SymTab.Name; .)
- 2220      = (. astStmt := AST.NoNode; .)
- 2221        ( AssOrCall
- 2222      | IfStat
- 2223      | WhileStat
- 2224      | RepeatStat
- 2225      | LoopStat
- 2226      | ForStat
- 2227      | CaseStat
- 2228      | WithStat
- 2229      | ReturnStat
- 2230      | HaltStat
- 2231      | NewStat
- 2232      | DisposeStat
- 2233      | IncDecStat
- 2234      | InclExclStat
- 2235      | "EXIT"                            (. IF NOT QbeGen.TopLoop(lx) THEN
- 2236                                               SemError(230) END;
- 2237                                             astStmt := AST.MakeNode(AST.NkExit); .)
- 2238      | "GOTO" GetIdent<lxnm>             (. NoteGoto(lxnm);
- 2239                                             astStmt := AST.MakeNode(AST.NkGoto);
- 2240                                             AST.SetChild(astStmt, 0,
- 2241                                               AST.MakeLeaf(AST.NkIdent, lxnm)); .) ) .
- 2242    (* INCL(set, elem) / EXCL(set, elem): PIM set-element builtins. *)
- 2243    InclExclStat                          (. VAR at, et2: SymTab.TypeIndex;
- 2244                                               dk: INTEGER;
- 2245                                               qd, qe: QbeGen.QVal;
- 2246                                               qn: SymTab.Name;
- 2247                                               sfx, isInc: BOOLEAN;
- 2248                                               astNode, astD: AST.Node; .)
- 2249      = ( "INCL"                          (. isInc := TRUE; .)
- 2250        | "EXCL"                          (. isInc := FALSE; .) )
- 2251        "(" Design<at, dk, qd, qn, sfx> (. astD := astCur; .) ","
- 2252        Expr<et2, qe> ")"
- 2253                                          (. astNode := AST.MakeNode(AST.NkCall);
- 2254                                             IF isInc THEN
- 2255                                               AST.SetChild(astNode, 0,
- 2256                                                 AST.MakeLeaf(AST.NkIdent, "INCL"))
- 2257                                             ELSE AST.SetChild(astNode, 0,
- 2258                                                 AST.MakeLeaf(AST.NkIdent, "EXCL"))
- 2259                                             END;
- 2260                                             IF astD # AST.NoNode THEN
- 2261                                               AST.SetChild(astNode, 1, astD) END;
- 2262                                             IF astCur # AST.NoNode THEN
- 2263                                               AST.SetChild(astNode, 2, astCur) END;
- 2264                                             astStmt := astNode; .)
- 2265                                          (. IF (at # SymTab.InvalidType)
- 2266    AND (SymTab.ClassOf(at) # SymTab.ClSet) THEN
- 2267                                               SemError(222)
- 2268                                             END; .) .
- 2269    (* INC(v [,step]) / DEC(v [,step]) as builtin statements over an
- 2270       integer designator. *)
- 2271    IncDecStat                            (. VAR dt, et2: SymTab.TypeIndex;
- 2272                                               dk: INTEGER;
- 2273                                               qd, qv, qn2, qstep:
- 2274                                                 QbeGen.QVal;
- 2275                                               qn: SymTab.Name;
- 2276                                               sfx, isInc: BOOLEAN;
- 2277                                               astNode, astD, astStep:
- 2278                                                 AST.Node; .)
- 2279      =                                   (. isInc := TRUE; .)
- 2280        ( "INC"                           (. isInc := TRUE; .)
- 2281        | "DEC"                           (. isInc := FALSE; .) )
- 2282        "("                               (. astStep := AST.NoNode; .)
- 2283        Design<dt, dk, qd, qn, sfx> (. astD := astCur; .)
- 2284        [ "," Expr<et2, qstep> (. astStep := astCur; .) ]
- 2285        ")"                               (. astNode := AST.MakeNode(AST.NkCall);
- 2286                                             IF isInc THEN
- 2287                                               AST.SetChild(astNode, 0,
- 2288                                                 AST.MakeLeaf(AST.NkIdent, "INC"))
- 2289                                             ELSE AST.SetChild(astNode, 0,
- 2290                                                 AST.MakeLeaf(AST.NkIdent, "DEC"))
- 2291                                             END;
- 2292                                             IF astD # AST.NoNode THEN
- 2293                                               AST.SetChild(astNode, 1, astD) END;
- 2294                                             IF astStep # AST.NoNode THEN
- 2295                                               AST.SetChild(astNode, 2, astStep) END;
- 2296                                             astStmt := astNode; .)                               (. IF dt = SymTab.InvalidType THEN
- 2297                                             ELSIF (dk # SymTab.KindVar)
- 2298   AND (dk # SymTab.KindParam)
- 2299   AND (dk # SymTab.KindField) THEN
- 2300                                               SemError(210)
- 2301                                             ELSIF NOT SymTab.IsOrdinal(dt) THEN
- 2302                                               SemError(211)
- 2303                                             END; .) .
- 2304    (* NEW/DISPOSE as builtin statements (no call syntax until step 4).
- 2305       Targets are pointer designators; DISPOSE nils afterwards (safer
- 2306       than Wirth-undefined; documented). DISPOSE is shallow. *)
- 2307    NewStat                               (. VAR dt: SymTab.TypeIndex;
- 2308                                               dk: INTEGER;
- 2309                                               qd, qm: QbeGen.QVal;
- 2310                                               qn: SymTab.Name;
- 2311                                               sfx: BOOLEAN;
- 2312                                               bt: SymTab.TypeIndex;
- 2313                                               astNode, astD: AST.Node; .)
- 2314      = "NEW" "(" Design<dt, dk, qd, qn, sfx> (. astD := astCur; .) ")"
- 2315                                          (. astNode := AST.MakeNode(AST.NkCall);
- 2316                                             AST.SetChild(astNode, 0,
- 2317                                               AST.MakeLeaf(AST.NkIdent, "NEW"));
- 2318                                             IF astD # AST.NoNode THEN
- 2319                                               AST.SetChild(astNode, 1, astD) END;
- 2320                                             astStmt := astNode; .)
- 2321                                           (. IF dt = SymTab.InvalidType THEN
- 2322                                              ELSIF (dk # SymTab.KindVar)
- 2323    AND (dk # SymTab.KindParam)
- 2324    AND (dk # SymTab.KindField) THEN
- 2325                                                SemError(210)
- 2326                                              ELSIF SymTab.ClassOf(dt) #
- 2327                                                    SymTab.ClPtr THEN
- 2328                                                SemError(219)
- 2329                                              END; .) .
- 2330    DisposeStat                           (. VAR dt: SymTab.TypeIndex;
- 2331                                               dk: INTEGER;
- 2332                                               qd, qv: QbeGen.QVal;
- 2333                                               qn: SymTab.Name;
- 2334                                               sfx: BOOLEAN;
- 2335                                               astNode, astD: AST.Node; .)
- 2336      = "DISPOSE" "(" Design<dt, dk, qd, qn, sfx> (. astD := astCur; .) ")"
- 2337                                          (. astNode := AST.MakeNode(AST.NkCall);
- 2338                                             AST.SetChild(astNode, 0,
- 2339                                               AST.MakeLeaf(AST.NkIdent, "DISPOSE"));
- 2340                                             IF astD # AST.NoNode THEN
- 2341                                               AST.SetChild(astNode, 1, astD) END;
- 2342                                             astStmt := astNode; .)
- 2343                                           (. IF dt = SymTab.InvalidType THEN
- 2344                                              ELSIF (dk # SymTab.KindVar)
- 2345    AND (dk # SymTab.KindParam)
- 2346    AND (dk # SymTab.KindField) THEN
- 2347                                                SemError(210)
- 2348                                              ELSIF SymTab.ClassOf(dt) #
- 2349                                                    SymTab.ClPtr THEN
- 2350                                                SemError(219)
- 2351                                              END; .) .
- 2352    (* WITH pushes each record's fields (inner wins) plus its base
- 2353       address; field designators resolve through both stacks. *)
- 2354    WithStat                              (. VAR nW: CARDINAL;
- 2355                                               astNode: AST.Node; .)
- 2356      = "WITH"                            (. nW := 0;
- 2357                                             astNode := AST.MakeNode(AST.NkWith); .)
- 2358        WithItem<nW, astNode> { "," WithItem<nW, astNode> }
- 2359        "DO"                              (. astStmt := AST.NoNode; .)
- 2360        [ StatSeq ] "END"                 (. AST.SetChild(astNode,
- 2361                                             AST.NChild(astNode), astStmt);
- 2362                                             astStmt := astNode;
- 2363                                             WHILE nW > 0 DO
- 2364                                               SymTab.PopScope;
- 2365                                               QbeGen.PopWith;
- 2366                                               DEC(nW)
- 2367                                             END; .) .
- 2368    WithItem<VAR nW: CARDINAL; wnode: AST.Node>
- 2369                                          (. VAR dt: SymTab.TypeIndex;
- 2370                                               dk: INTEGER;
- 2371                                               qd, qe: QbeGen.QVal;
- 2372                                               qn: SymTab.Name;
- 2373                                               sfx: BOOLEAN; .)
- 2374      = Design<dt, dk, qd, qn, sfx>
- 2375                                          (. IF astCur # AST.NoNode THEN
- 2376                                               AST.SetChild(wnode,
- 2377                                                 AST.NChild(wnode), astCur) END;
- 2378                                             IF dt = SymTab.InvalidType THEN
- 2379                                             ELSIF (SymTab.ClassOf(dt) #
- 2380                                                    SymTab.ClRecord)
- 2381   AND (SymTab.ClassOf(dt) #
- 2382                                                   SymTab.ClClass) THEN
- 2383                                               SemError(215)
- 2384                                             ELSIF SymTab.PushRecord(dt) THEN
- 2385                                               QbeGen.PushWith(qd);
- 2386                                               INC(nW)
- 2387                                             END; .) .
- 2388    (* Assignment or procedure-statement call (4.1, module level).
- 2389       Bare `P;` is a syntax error; function-as-statement is 233. *)
- 2390    AssOrCall                             (. VAR dt, et: SymTab.TypeIndex;
- 2391                                               dk: INTEGER;
- 2392                                               qd, qe, qt, ql: QbeGen.QVal;
- 2393                                               qn: SymTab.Name;
- 2394                                               ct2, res0: SymTab.TypeIndex;
- 2395                                               q2, mg0: QbeGen.QVal;
- 2396                                               isR, conv, wconv: BOOLEAN;
- 2397                                               called, sfx: BOOLEAN;
- 2398                                               astLhs, astRes: AST.Node; mname: SymTab.Name; isM: BOOLEAN;
- 2399                                               n: SymTab.Name; astLab, astNode: AST.Node; .)
- 2400      = GetIdent<n>
- 2401        ( ":"                             (. NoteLabel(n);
- 2402                                             astNode := AST.MakeNode(AST.NkLabel);
- 2403                                             AST.SetChild(astNode, 0,
- 2404                                               AST.MakeLeaf(AST.NkIdent, n));
- 2405                                             astLab := AST.MakeNode(AST.NkBlock);
- 2406                                             AST.SetChild(astLab, 0, astNode); .)
- 2407          Statement                       (. IF astStmt # AST.NoNode THEN
- 2408                                               AST.SetChild(astLab, 1, astStmt) END;
- 2409                                             astStmt := astLab; .)
- 2410        | DesignTail<n, dt, dk, qd, qn, sfx>
- 2411        (. astLhs := astCur; astNArgs := 0; .)
- 2412        ( ":="
- 2413          Expr<et, qe>                    (. astStmt := AST.MakeBin(
- 2414                                               AST.NkAssign, 0, astLhs, astCur);
- 2415                                             IF (dt # SymTab.InvalidType)
- 2416   AND (dk # SymTab.KindVar)
- 2417   AND (dk # SymTab.KindParam)
- 2418   AND (dk # SymTab.KindField) THEN
- 2419                                             SemError(210)
- 2420                                           ELSIF NOT SymTab.Assignable(et,
- 2421                                                    dt) THEN
- 2422                                             SemError(210)
- 2423                                           ELSIF (dt # SymTab.InvalidType)
- 2424   AND (SymTab.ClassOf(dt) =
- 2425                                                 SymTab.ClClass) THEN
- 2426                                             SemError(230) END;
- 2427                                           isR := (dt #
- 2428                                                   SymTab.InvalidType)
- 2429   AND (SymTab.ClassOf(dt)
- 2430                                                     = SymTab.ClReal);
- 2431                                           conv := isR
- 2432   AND SymTab.IsIntFamily(et);
- 2433                                           wconv := (dt #
- 2434                                                     SymTab.InvalidType)
- 2435   AND SymTab.IsLongFamily(dt)
- 2436   AND SymTab.IsIntFamily(et);
- 2437                                           IF ((dk = SymTab.KindVar)
- 2438                                               OR (dk = SymTab.KindParam)
- 2439                                               OR (dk = SymTab.KindField))
- 2440   AND (dt # SymTab.InvalidType)
- 2441   AND (et # SymTab.InvalidType)
- 2442   AND (SymTab.ClassOf(dt) #
- 2443                                                 SymTab.ClClass) THEN
- 2444                                           END; .)
- 2445        | ArgList<qn, dt, qd, TRUE, TRUE, methCls, ct2, q2, called>
- 2446                                          (. astRes := AstCallNode(astLhs);
- 2447                                             sfx := FALSE; .)
- 2448          ( { ResultComp<ct2, q2, sfx, astRes, mname, methCls, isM> }
- 2449            ":=" Expr<et, qe>             (. astStmt := AST.MakeBin(
- 2450                                               AST.NkAssign, 0, astRes, astCur);
- 2451                                             IF NOT sfx THEN
- 2452                                               SemError(233)
- 2453                                             ELSIF (ct2 # SymTab.InvalidType)
- 2454    AND NOT SymTab.Assignable(et, ct2) THEN
- 2455                                               SemError(210)
- 2456                                             END; .)
- 2457          |                               (. (* discarding the result of a
- 2458                                               foreign C varargs call
- 2459                                               (printf/snprintf) is accepted;
- 2460                                               an ordinary Modula-2 function
- 2461                                               used as a statement stays 233 *)
- 2462                                             IF (ct2 # SymTab.InvalidType)
- 2463                                                AND NOT SymTab.Varargs(qn) THEN
- 2464                                               SemError(233) END;
- 2465                                             astStmt := astRes; .) )
- 2466        |                                 (* bare `P;`: proper parameterless
- 2467                                              procedure call; anything else
- 2468                                              here is 233 (was a bare syntax
- 2469                                              error before 4.2) *)
- 2470                                          (. astStmt := AstCallNode(astLhs);
- 2471                                              IF (dk = SymTab.KindProc)
- 2472   AND NOT sfx THEN
- 2473                                               res0 := SymTab.ProcRes(qn);
- 2474                                               IF res0 #
- 2475                                                  SymTab.InvalidType THEN
- 2476                                                 SemError(233)
- 2477                                               ELSIF SymTab.ProcNPar(qn) #
- 2478                                                       0 THEN
- 2479                                                 SemError(233)
- 2480                                               END
- 2481                                             ELSIF (dt # SymTab.InvalidType)
- 2482    AND (SymTab.ClassOf(dt) = SymTab.ClProc) THEN
- 2483                                               IF SymTab.ProcTypeRes(dt) #
- 2484                                                  SymTab.InvalidType THEN
- 2485                                                 SemError(233)
- 2486                                               ELSIF SymTab.ProcTypeNPar(dt) #
- 2487                                                       0 THEN
- 2488                                                 SemError(233)
- 2489                                               END
- 2490                                             ELSE SemError(233)
- 2491                                              END; .) ) ) .
- 2492    (* Actual-parameter list shared by statement and expression calls.
- 2493       want selects CallEnd's result handling; t/q carry the call
- 2494       value (statement calls discard). Arity/type failures are 233;
- 2495       evaluation code still emits so the .ssa stays assembleable. *)
- 2496    ArgList<pn: SymTab.Name; pt: SymTab.TypeIndex; callee: QbeGen.QVal;
- 2497            want: BOOLEAN; soft: BOOLEAN; methCls: SymTab.TypeIndex;
- 2498            VAR t: SymTab.TypeIndex; VAR q: QbeGen.QVal;
- 2499            VAR called: BOOLEAN>          (. VAR i, np: CARDINAL;
- 2500                                               vs: INTEGER;
- 2501                                               res: SymTab.TypeIndex;
- 2502                                               mg: QbeGen.QVal;
- 2503                                               ok, ind, isMeth, va, isConv: BOOLEAN; .)
- 2504      = "("                               (. called := TRUE;
- 2505                                             ok := TRUE;
- 2506                                             ind := FALSE;
- 2507                                             isConv := FALSE;
- 2508                                             isMeth := methCls #
- 2509                                               SymTab.InvalidType;
- 2510                                             IF isMeth THEN
- 2511                                               res := SymTab.ClassMethodRes(methCls, pn)
- 2512                                             ELSIF SymTab.SymKind(pn) = SymTab.KindProc THEN
- 2513                                               res := SymTab.ProcRes(pn)
- 2514                                             ELSIF (SymTab.SymKind(pn) = SymTab.KindType)
- 2515    OR (SymTab.SymKind(pn) = SymTab.KindPredef) THEN
- 2516                                               (* ISO type conversion T(x):
- 2517                                                  one value, result is T *)
- 2518                                               isConv := TRUE;
- 2519                                               res := SymTab.SymType(pn)
- 2520                                             ELSIF (pt # SymTab.InvalidType)
- 2521    AND (SymTab.ClassOf(pt) = SymTab.ClProc) THEN
- 2522                                               ind := TRUE;
- 2523                                               res := SymTab.ProcTypeRes(pt)
- 2524                                             ELSE SemError(233);
- 2525                                               ok := FALSE;
- 2526                                               res := SymTab.InvalidType
- 2527                                             END;
- 2528                                             i := 0; .)
- 2529        [ ActParam<pn, pt, ind, methCls, i>        (. INC(i); .)
- 2530          { "," ActParam<pn, pt, ind, methCls, i>  (. INC(i); .) } ]
- 2531        ")"                               (. IF ok THEN
- 2532                                               IF isConv THEN
- 2533                                                 (* a conversion takes
- 2534                                                    exactly one value *)
- 2535                                                 IF i # 1 THEN
- 2536                                                   SemError(233); ok := FALSE
- 2537                                                 END
- 2538                                               ELSE
- 2539                                                 IF isMeth THEN
- 2540                                                   np := SymTab.ClassMethodNPar(
- 2541                                                     methCls, pn)
- 2542                                                 ELSIF ind THEN
- 2543                                                   np := SymTab.ProcTypeNPar(pt)
- 2544                                                 ELSE np := SymTab.ProcNPar(pn)
- 2545                                                 END;
- 2546                                                 va := (NOT isMeth) AND (NOT ind)
- 2547                                                   AND (SymTab.SymKind(pn) =
- 2548                                                        SymTab.KindProc)
- 2549                                                   AND SymTab.Varargs(pn);
- 2550                                                 IF (i # np) AND NOT va THEN
- 2551                                                   SemError(233); ok := FALSE
- 2552                                                 END
- 2553                                               END
- 2554                                             END;
- 2555                                             IF NOT ok THEN
- 2556                                               t := SymTab.InvalidType;
- 2557                                               QbeGen.CopyOp("0", q)
- 2558                                             ELSIF want THEN
- 2559                                               IF res =
- 2560                                                  SymTab.InvalidType THEN
- 2561                                                 IF NOT soft THEN SemError(233) END;
- 2562                                                 t := SymTab.InvalidType;
- 2563                                                 QbeGen.CopyOp("0", q)
- 2564                                               ELSE t := res;
- 2565                                                  QbeGen.CopyOp("@", q)
- 2566                                               END
- 2567                                             ELSE
- 2568                                               (* a function call used as
- 2569                                                  a statement: allowed for
- 2570                                                  a foreign C varargs proc
- 2571                                                  (printf/snprintf), whose
- 2572                                                  result is conventionally
- 2573                                                  discarded; ordinary
- 2574                                                  Modula-2 functions keep
- 2575                                                  the 233 diagnostic *)
- 2576                                               IF (res # SymTab.InvalidType)
- 2577                                                  AND NOT va THEN
- 2578                                                 SemError(233)
- 2579                                               END;
- 2580                                               t := SymTab.InvalidType;
- 2581                                               QbeGen.CopyOp("0", q);
- 2582                                             END; .) .
- 2583    (* One actual: VAR formals take recorded designator addresses
- 2584       (233 otherwise); value formals take converted expressions. *)
- 2585    ActParam<pn: SymTab.Name; pt: SymTab.TypeIndex; ind: BOOLEAN;
- 2586             methCls: SymTab.TypeIndex; i: CARDINAL>
- 2587                                          (. VAR at, ft: SymTab.TypeIndex;
- 2588                                               qe, qa, qt: QbeGen.QVal;
- 2589                                               isV, conv, va: BOOLEAN;
- 2590                                               cl: CHAR;
- 2591                                               savedN, aj: CARDINAL;
- 2592                                               savedArgs: ARRAY [0 .. 31]
- 2593                                                 OF AST.Node;
- 2594                                               astActual: AST.Node; .)
- 2595      =                                   (. (* Parsing the actual can clobber
- 2596                                               the enclosing call's argument
- 2597                                               list (Factor resets astNArgs),
- 2598                                               so save/restore it. *)
- 2599                                             savedN := astNArgs; aj := 0;
- 2600                                             WHILE aj <= HIGH(astArgs) DO
- 2601                                               savedArgs[aj] := astArgs[aj];
- 2602                                               INC(aj)
- 2603                                             END; .)
- 2604        Expr<at, qe>                      (. QbeGen.CopyOp(qe, convQ); convT := at;
- 2605                                             astActual := astCur;
- 2606                                             astNArgs := savedN; aj := 0;
- 2607                                             WHILE aj <= HIGH(astArgs) DO
- 2608                                               astArgs[aj] := savedArgs[aj];
- 2609                                               INC(aj)
- 2610                                             END;
- 2611                                             IF astNArgs <= HIGH(astArgs) THEN
- 2612                                               astArgs[astNArgs] := astCur;
- 2613                                               INC(astNArgs)
- 2614                                             ELSE SemError(230)
- 2615                                               (* > 32 actuals: impl limit *)
- 2616                                             END;
- 2617                                             va := (NOT ind)
- 2618                                               AND (methCls =
- 2619                                                  SymTab.InvalidType)
- 2620                                               AND (SymTab.SymKind(pn) =
- 2621                                                  SymTab.KindProc)
- 2622                                               AND SymTab.Varargs(pn);
- 2623                                             IF ind THEN
- 2624                                               ft :=
- 2625                                                 SymTab.ProcTypeParamType(pt,
- 2626                                                   i);
- 2627                                               isV :=
- 2628                                                 SymTab.ProcTypeParamIsVar(pt,
- 2629                                                   i)
- 2630                                             ELSIF methCls #
- 2631                                                SymTab.InvalidType THEN
- 2632                                               ft :=
- 2633                                                 SymTab.ClassMethodParamType(
- 2634                                                 methCls, pn, i);
- 2635                                               isV :=
- 2636                                                 SymTab.ClassMethodParamIsVar(
- 2637                                                 methCls, pn, i)
- 2638                                             ELSE
- 2639                                               ft := SymTab.ParamType(pn, i);
- 2640                                               isV := SymTab.ParamIsVar(pn, i)
- 2641                                             END;
- 2642                                             IF (at = SymTab.InvalidType) THEN
- 2643                                             ELSIF ft = SymTab.InvalidType THEN
- 2644                                             ELSIF isV THEN
- 2645                                               IF (SymTab.ClassOf(at) = SymTab.ClChar)
- 2646    AND (SymTab.ClassOf(ft) = SymTab.ClArray)
- 2647    AND (SymTab.ClassOf(SymTab.ArrayElem(ft)) = SymTab.ClChar)
- 2648    AND QbeGen.IsImm(qe) THEN
- 2649                                               ELSIF (AST.Kind(astActual) #
- 2650                                                      AST.NkDesignator)
- 2651    AND (AST.Kind(astActual) # AST.NkStrLit) THEN
- 2652                                                 SemError(233)
- 2653                                               ELSIF NOT SymTab.VarParamOk(at, ft)
- 2654     AND NOT SymTab.ByteBufOk(at, ft) THEN
- 2655                                                 SemError(233)
- 2656                                               END
- 2657                                             ELSE
- 2658                                               IF (SymTab.ClassOf(at) = SymTab.ClChar)
- 2659    AND (SymTab.ClassOf(ft) = SymTab.ClArray)
- 2660    AND (SymTab.ClassOf(SymTab.ArrayElem(ft)) = SymTab.ClChar)
- 2661    AND QbeGen.IsImm(qe) THEN
- 2662                                               ELSIF NOT SymTab.Assignable(at, ft)
- 2663     AND NOT SymTab.ByteBufOk(at, ft) THEN
- 2664                                                 SemError(233)
- 2665                                               END
- 2666                                             END; .) .
- 2667    IfStat                                (. VAR t: SymTab.TypeIndex;
- 2668                                               q: QbeGen.QVal;
- 2669                                               hasElse: BOOLEAN;
- 2670                                               astCond, astIf, astLast,
- 2671                                               astNode: AST.Node; .)
- 2672      = "IF" (. hasElse := FALSE; .)
- 2673        Expr<t, q> (. astCond := astCur; astStmt := AST.NoNode;
- 2674                                             IF NOT SymTab.BoolCheck(t) THEN
- 2675                                               SemError(214) END; .)
- 2676        "THEN" [ StatSeq ]                (. astNode := AST.MakeNode(AST.NkIf);
- 2677                                             AST.SetChild(astNode, 0, astCond);
- 2678                                             AST.SetChild(astNode, 1, astStmt);
- 2679                                             astIf := astNode;
- 2680                                             astLast := astNode; .)
- 2681        { "ELSIF"
- 2682          Expr<t, q> (. astCond := astCur; astStmt := AST.NoNode;
- 2683                                             IF NOT SymTab.BoolCheck(t) THEN
- 2684                                               SemError(214) END; .)
- 2685          "THEN" [ StatSeq ]              (. astNode := AST.MakeNode(AST.NkIf);
- 2686                                             AST.SetChild(astNode, 0, astCond);
- 2687                                             AST.SetChild(astNode, 1, astStmt);
- 2688                                             AST.SetChild(astLast, 2, astNode);
- 2689                                             astLast := astNode; .) }
- 2690        [ "ELSE"                          (. hasElse := TRUE;
- 2691                                             astStmt := AST.NoNode; .)
- 2692          [ StatSeq ] (. AST.SetChild(astLast, 2, astStmt); .) ]
- 2693        "END" (. astStmt := astIf; .) .
- 2694    WhileStat                             (. VAR t: SymTab.TypeIndex;
- 2695                                               q: QbeGen.QVal;
- 2696                                               astCond, astNode: AST.Node; .)
- 2697      = "WHILE" (. astStmt := AST.NoNode; .)
- 2698        Expr<t, q> (. astCond := astCur;
- 2699                                             IF NOT SymTab.BoolCheck(t) THEN
- 2700                                               SemError(214) END; .)
- 2701        "DO" [ StatSeq ]                  (. astNode := AST.MakeNode(AST.NkWhile);
- 2702                                             AST.SetChild(astNode, 0, astCond);
- 2703                                             AST.SetChild(astNode, 1, astStmt);
- 2704                                             astStmt := astNode; .)
- 2705        "END" .
- 2706    RepeatStat                            (. VAR t: SymTab.TypeIndex;
- 2707                                               q: QbeGen.QVal;
- 2708                                               astCond, astBody, astNode:
- 2709                                                 AST.Node; .)
- 2710      = "REPEAT" (. astStmt := AST.NoNode; .)
- 2711        [ StatSeq ] (. astBody := astStmt; .)
- 2712        "UNTIL" Expr<t, q> (. astCond := astCur;
- 2713                                             astNode := AST.MakeNode(AST.NkRepeat);
- 2714                                             AST.SetChild(astNode, 0, astBody);
- 2715                                             AST.SetChild(astNode, 1, astCond);
- 2716                                             astStmt := astNode;
- 2717                                             IF NOT SymTab.BoolCheck(t) THEN
- 2718                                               SemError(214) END; .) .
- 2719    LoopStat                              (. VAR lEnd: QbeGen.QVal; astNode: AST.Node; .)
- 2720      = "LOOP"                            (. astStmt := AST.NoNode;
- 2721                                             QbeGen.NewLabel(lEnd);
- 2722                                             QbeGen.PushLoop(lEnd); .)
- 2723        [ StatSeq ]
- 2724        "END"                             (. astNode := AST.MakeNode(AST.NkLoop);
- 2725                                             AST.SetChild(astNode, 0, astStmt);
- 2726                                             astStmt := astNode;
- 2727                                             QbeGen.PopLoop; .) .
- 2728    (* FOR with static-sign BY (literal, non-zero; 220 otherwise).
- 2729       Runtime direction would need a compare-select; the literal
- 2730       sign picks cslew/csegew at "DO" time. *)
- 2731    ForStat                               (. VAR lv: SymTab.Name;
- 2732                                               tlo, thi, tby:
- 2733                                                 SymTab.TypeIndex;
- 2734                                               qlo, qhi, qby, qt, qk, qb:
- 2735                                                 QbeGen.QVal;
- 2736                                               lTop, lBody, lEnd:
- 2737                                                 QbeGen.QVal;
- 2738                                               by: INTEGER;
- 2739                                               ok: BOOLEAN;
- 2740                                               astVar, astLo, astHi, astBy,
- 2741                                               astNode: AST.Node; .)
- 2742      = "FOR"                             (. by := 1; .)
- 2743        GetIdent<lv> (. astVar := AST.MakeLeaf(AST.NkIdent, lv);
- 2744                                             astStmt := AST.NoNode;
- 2745                                             astBy := AST.NoNode;
- 2746                                             ok := SymTab.Lookup(lv);
- 2747                                             IF NOT ok THEN
- 2748                                               SemError(201)
- 2749                                             ELSIF (SymTab.SymKind(lv) #
- 2750                                                    SymTab.KindVar)
- 2751   AND (SymTab.SymKind(lv) #
- 2752                                                   SymTab.KindParam) THEN
- 2753                                               SemError(220); ok := FALSE
- 2754                                             ELSIF NOT SymTab.IsOrdinal(
- 2755                                                     SymTab.SymType(lv)) THEN
- 2756                                               SemError(220); ok := FALSE
- 2757                                             END; .)
- 2758        ":=" Expr<tlo, qlo> (. astLo := astCur;
- 2759                                             IF NOT SymTab.Assignable(tlo,
- 2760                                                  SymTab.SymType(lv)) THEN
- 2761                                               SemError(220); ok := FALSE
- 2762                                             END; .)
- 2763        "TO" Expr<thi, qhi> (. astHi := astCur;
- 2764                                             IF NOT SymTab.Assignable(thi,
- 2765                                                  SymTab.SymType(lv)) THEN
- 2766                                               SemError(220); ok := FALSE
- 2767                                             END; .)
- 2768        [ "BY" Expr<tby, qby> (. astBy := astCur;
- 2769                                             IF (tby #
- 2770                                               SymTab.InvalidType)
- 2771   AND NOT SymTab.IsIntFamily(tby) THEN
- 2772                                               SemError(220); ok := FALSE
- 2773                                             END;
- 2774                                             IF NOT SymTab.ConstInt(qby, by) THEN
- 2775                                               SemError(230); by := 1
- 2776                                             ELSIF by = 0 THEN
- 2777                                               SemError(220); by := 1
- 2778                                             END; .) ]
- 2779        "DO"
- 2780        [ StatSeq ]
- 2781        "END" (. astNode := AST.MakeNode(AST.NkFor);
- 2782                                             AST.SetChild(astNode, 0, astVar);
- 2783                                             AST.SetChild(astNode, 1, astLo);
- 2784                                             AST.SetChild(astNode, 2, astHi);
- 2785                                             AST.SetChild(astNode, 3, astBy);
- 2786                                             AST.SetChild(astNode, 4, astStmt);
- 2787                                             astStmt := astNode;
- 2788                                             .) .
- 2789    CaseStat                              (. VAR tsel: SymTab.TypeIndex;
- 2790                                               qsel, lEnd: QbeGen.QVal;
- 2791                                               arm, astNode, astArms,
- 2792                                               astArmsTail: AST.Node; .)
- 2793      = "CASE" Expr<tsel, qsel>           (. astNode := AST.MakeNode(AST.NkCase);
- 2794                                             AST.SetChild(astNode, 0, astCur);
- 2795                                             astArms := AST.NoNode;
- 2796                                             astArmsTail := AST.NoNode;
- 2797                                             .)
- 2798        "OF" [ "|" ] CaseAlt<tsel, qsel, lEnd, astArms, astArmsTail>
- 2799        { "|" CaseAlt<tsel, qsel, lEnd, astArms, astArmsTail> }
- 2800        [ "ELSE"                          (. astStmt := AST.NoNode; .)
- 2801          [ StatSeq ]                     (. arm := AST.MakeNode(AST.NkCaseArm);
- 2802                                             AST.SetOp(arm, 1);
- 2803                                             AST.SetChild(arm, 0, astStmt);
- 2804                                             AstAppend(AST.NkBlock,
- 2805                                               astArms, astArmsTail, arm); .) ]
- 2806        "END"                             (. AST.SetChild(astNode, 1, astArms);
- 2807                                             astStmt := astNode;
- 2808                                             .) .
- 2809    (* Compare-chain lowering: each alternative ends its match-tests
- 2810       with "jmp lAfter", so the no-match fallthrough skips the body:
- 2811       "cmp; jnz(lBody,lF); lF: ... ; jmp lAfter; lBody: S; jmp lEnd;
- 2812       lAfter:". Falls into the next alternative, ELSE, or END. *)
- 2813    CaseAlt<tsel: SymTab.TypeIndex; qsel: QbeGen.QVal;
- 2814            lEnd: QbeGen.QVal; VAR arms, armsTail: AST.Node>
- 2815                                          (. VAR arm: AST.Node; .)
- 2816      =                                   (. arm := AST.MakeNode(AST.NkCaseArm); .)
- 2817        CaseLabel<tsel, qsel, arm>
- 2818        { "," CaseLabel<tsel, qsel, arm> }
- 2819        ":"                               (. astStmt := AST.NoNode; .)
- 2820        [ StatSeq ]                       (. AST.SetChild(arm, AST.NChild(arm),
- 2821                                             astStmt);
- 2822                                             AstAppend(AST.NkBlock,
- 2823                                               arms, armsTail, arm);
- 2824                                             .) .
- 2825    CaseLabel<tsel: SymTab.TypeIndex; qsel: QbeGen.QVal;
- 2826              arm: AST.Node>
- 2827                                          (. VAR t2, t3: SymTab.TypeIndex;
- 2828                                               q2, q3, qc, qd, qe:
- 2829                                                 QbeGen.QVal;
- 2830                                               astLab: AST.Node;
- 2831                                               lNext: QbeGen.QVal; .)
- 2832      = Expr<t2, q2> (. astLab := astCur;
- 2833                                             IF SymTab.IsEmptyStr(t2)
- 2834                                                AND (SymTab.ClassOf(tsel) =
- 2835                                                     SymTab.ClChar) THEN
- 2836                                               (* ISO: '' as a CASE label
- 2837                                                  is the terminator *)
- 2838                                               QbeGen.CopyOp("0", q2);
- 2839                                               t2 := SymTab.CharType()
- 2840                                             END;
- 2841                                             IF (t2 #
- 2842                                               SymTab.InvalidType)
- 2843   AND (tsel #
- 2844                                                 SymTab.InvalidType)
- 2845   AND NOT SymTab.EqCheck(t2,
- 2846                                                   tsel) THEN
- 2847                                               SemError(213) END;
- 2848                                             (* set labels are not immediates:
- 2849                                                the CASE chain uses CmpSet *)
- 2850                                             IF (SymTab.ClassOf(t2) # SymTab.ClSet)
- 2851   AND NOT QbeGen.IsImm(q2) THEN
- 2852                                               SemError(230)
- 2853                                             END; .)
- 2854        [ ".." Expr<t3, q3>               (. astLab := AST.MakeBin(
- 2855                                               AST.NkSubrange, 0, astLab, astCur);
- 2856                                             IF SymTab.IsEmptyStr(t3)
- 2857                                                AND (SymTab.ClassOf(tsel) =
- 2858                                                     SymTab.ClChar) THEN
- 2859                                               QbeGen.CopyOp("0", q3);
- 2860                                               t3 := SymTab.CharType()
- 2861                                             END;
- 2862                                             IF (t3 #
- 2863                                               SymTab.InvalidType)
- 2864   AND (tsel #
- 2865                                                 SymTab.InvalidType)
- 2866   AND NOT SymTab.EqCheck(t3,
- 2867                                                   tsel) THEN
- 2868                                               SemError(213) END;
- 2869                                                 IF (SymTab.ClassOf(t3) # SymTab.ClSet)
- 2870   AND NOT QbeGen.IsImm(q3) THEN
- 2871                                                   SemError(230)
- 2872                                                 END; .) ]
- 2873                                          (. AST.SetChild(arm,
- 2874                                               AST.NChild(arm), astLab); .) .
- 2875    ReturnStat                            (. VAR t: SymTab.TypeIndex;
- 2876                                               q, qt: QbeGen.QVal;
- 2877                                               res: SymTab.TypeIndex;
- 2878                                               hadE, conv: BOOLEAN;
- 2879                                               astVal, astNode: AST.Node; .)
- 2880      = "RETURN"                          (. hadE := FALSE; astStmt := AST.NoNode; .)
- 2881        [ Expr<t, q> (. hadE := TRUE; astVal := astCur; .) ]
- 2882                                          (. astNode := AST.MakeNode(AST.NkReturn);
- 2883                                             IF hadE THEN
- 2884                                               AST.SetChild(astNode, 0, astVal)
- 2885                                             END;
- 2886                                             astStmt := astNode;
- 2887                                             conv := FALSE;
- 2888                                             IF NOT SymTab.InProc() THEN
- 2889                                               SemError(232)
- 2890                                             ELSE res := SymTab.CurRes();
- 2891                                               IF NOT hadE THEN
- 2892                                                 IF res #
- 2893                                                    SymTab.InvalidType THEN
- 2894                                                   SemError(232)
- 2895                                                 END
- 2896                                               ELSIF (res =
- 2897                                                      SymTab.InvalidType)
- 2898                                                  OR (t #
- 2899                                                      SymTab.InvalidType)
- 2900   AND NOT SymTab.Assignable(t,
- 2901                                                       res) THEN
- 2902                                                 SemError(232)
- 2903                                             END
- 2904                                             END; .) .
- 2905    HaltStat                              (. VAR t: SymTab.TypeIndex;
- 2906                                               q: QbeGen.QVal;
- 2907                                               astVal, astNode: AST.Node; .)
- 2908      = "HALT" (. astVal := AST.NoNode; .)
- 2909        [ "(" Expr<t, q> (. astVal := astCur; .) ")" ]
- 2910                                          (. astNode := AST.MakeNode(AST.NkHalt);
- 2911                                             IF astVal # AST.NoNode THEN
- 2912                                               AST.SetChild(astNode, 0, astVal)
- 2913                                             END;
- 2914                                             astStmt := astNode;
- 2915                                             .) .
- 2916    (* Designator: scalar loads, array addresses, and index suffixes.
- 2917       Each index descends one level (bounds-checked, trap on breach);
- 2918       nested levels reload the inner descriptor address. q ends as the
- 2919       value (scalars), the descriptor address (plain arrays), or the
- 2920       element address (indexed); sfx marks the indexed form. *)
- 2921    Design<VAR t: SymTab.TypeIndex; VAR k: INTEGER;
- 2922           VAR q: QbeGen.QVal; VAR qn: SymTab.Name; VAR sfx: BOOLEAN>
- 2923                                          (. VAR n: SymTab.Name; .)
- 2924      = GetIdent<n> DesignTail<n, t, k, q, qn, sfx> .
- 2925    (* The part of Design after the identifier: resolve it and walk the
- 2926       selectors.  Split out so a statement can decide between a label
- 2927       (`ident :`) and a designator (`ident := ...`) with one token. *)
- 2928    DesignTail<VAR n: SymTab.Name; VAR t: SymTab.TypeIndex; VAR k: INTEGER;
- 2929           VAR q: QbeGen.QVal; VAR qn: SymTab.Name; VAR sfx: BOOLEAN>
- 2930                                          (. VAR fn, mal: SymTab.Name;
- 2931                                               cls: INTEGER;
- 2932                                               ic: SymTab.TypeIndex;
- 2933                                               curT, it, eT, bt:
- 2934                                                 SymTab.TypeIndex;
- 2935                                               iq, ql, qlo, qhi, qe:
- 2936                                                 QbeGen.QVal;
- 2937                                               lo, hi: INTEGER;
- 2938                                               fo: INTEGER;
- 2939                                               isOpen: BOOLEAN;
- 2940                                               qb, cv: QbeGen.QVal;
- 2941                                               r: BOOLEAN;
- 2942                                                astDes, astSel: AST.Node; .)
- 2943      =                                   (. methCls := SymTab.InvalidType;
- 2944                                             QbeGen.CopyOp(n, qn);
- 2945                                             sfx := FALSE;
- 2946                                             IF NOT SymTab.Lookup(n) THEN
- 2947                                               (* a bare method name inside
- 2948                                                  a CLASS IMPLEMENTATION
- 2949                                                  is a sibling call on
- 2950                                                  THIS *)
- 2951                                               ic := SymTab.CurImplClass();
- 2952                                               IF (ic #
- 2953                                                  SymTab.InvalidType)
- 2954    AND SymTab.MethodExists(ic, n) THEN
- 2955                                                 sfx := FALSE;
- 2956                                                  QbeGen.CopyOp("@", q);
- 2957                                                 methCls := ic;
- 2958                                                 k := SymTab.KindProc;
- 2959                                                 t := SymTab.InvalidType
- 2960                                               ELSIF SymTab.InProc() THEN
- 2961                                                 (* not declared anywhere
- 2962                                                    in scope: with bodies
- 2963                                                    parsed at unit end this
- 2964                                                    is a genuine 201 (a
- 2965                                                    nested-local forward is
- 2966                                                    no longer tolerated). *)
- 2967                                                 SemError(201);
- 2968                                                 t := SymTab.InvalidType;
- 2969                                                 k := -1;
- 2970                                                 QbeGen.CopyOp("0", q)
- 2971                                               ELSE
- 2972                                                 SemError(201);
- 2973                                                 t :=
- 2974                                                   SymTab.InvalidType;
- 2975                                                 k := -1;
- 2976                                                 QbeGen.CopyOp("0", q)
- 2977                                               END
- 2978                                             ELSE
- 2979                                               t := SymTab.SymType(n);
- 2980                                               k := SymTab.SymKind(n);
- 2981                                               IF k = SymTab.KindConst THEN
- 2982                                                 IF SymTab.Equal(n,
- 2983                                                    "TRUE") THEN
- 2984                                                   t := SymTab.BoolType();
- 2985                                                   QbeGen.CopyOp("1", q)
- 2986                                                 ELSIF SymTab.Equal(n,
- 2987                                                    "FALSE") THEN
- 2988                                                   t := SymTab.BoolType();
- 2989                                                   QbeGen.CopyOp("0", q)
- 2990                                                 ELSIF SymTab.Equal(n,
- 2991                                                    "NIL") THEN
- 2992                                                   QbeGen.CopyOp("0", q)
- 2993                                                 ELSE
- 2994                                                   cls :=
- 2995                                                     SymTab.ClassOf(t);
- 2996                                                   IF (t #
- 2997                                                       SymTab.InvalidType)
- 2998   AND ((cls = SymTab.ClInt)
- 2999                                                      OR (cls
- 3000                                                          = SymTab.ClChar)
- 3001                                                      OR (cls
- 3002                                                          = SymTab.ClEnum)
- 3003                                                      OR (cls
- 3004                                                          = SymTab.ClReal)
- 3005                                                      OR (cls
- 3006                                                          = SymTab.ClLong)
- 3007                                                      OR (cls
- 3008                                                          = SymTab.ClNil)
- 3009                                                      OR (cls = SymTab.ClByte)
- 3010                                                      OR (cls = SymTab.ClSByte)
- 3011                                                      OR (cls = SymTab.ClWord16)
- 3012                                                      OR (cls = SymTab.ClSWord16)
- 3013                                                       OR (cls = SymTab.ClBool)) THEN
- 3014                                                     IF cls = SymTab.ClNil THEN
- 3015                                                       QbeGen.CopyOp("0", q)
- 3016                                                     ELSIF ((cls
- 3017                                                         = SymTab.ClInt)
- 3018                                                       OR (cls
- 3019                                                         = SymTab.ClChar)
- 3020                                                       OR (cls
- 3021                                                         = SymTab.ClEnum)
- 3022                                                       OR (cls
- 3023                                                         = SymTab.ClLong)
- 3024                                                        OR (cls = SymTab.ClByte)
- 3025                                                        OR (cls = SymTab.ClSByte)
- 3026                                                        OR (cls = SymTab.ClWord16)
- 3027                                                        OR (cls = SymTab.ClSWord16)
- 3028                                                        OR (cls = SymTab.ClBool))
- 3029    AND SymTab.GetSymVal(n, cv)
- 3030    AND QbeGen.IsImm(cv) THEN
- 3031                                                       QbeGen.CopyOp(cv, q)
- 3032                                                     ELSE
- 3033                                                       QbeGen.LoadVar(n,
- 3034                                                         cls = SymTab.ClReal,
- 3035                                                         q)
- 3036                                                     END
- 3037                                                   ELSIF (cls = SymTab.ClArray)
- 3038                                                      OR (cls = SymTab.ClRecord)
- 3039                                                      OR (cls = SymTab.ClClass)
- 3040                                                      OR (cls = SymTab.ClStr)
- 3041                                                      OR (cls = SymTab.ClUStr)
- 3042                                                      OR (cls = SymTab.ClSet) THEN
- 3043                                                     (* aggregate constant:
- 3044                                                        its value IS the
- 3045                                                        descriptor address *)
- 3046                                                     IF SymTab.GetSymVal(n, cv) THEN
- 3047                                                       QbeGen.CopyOp(cv, q)
- 3048                                                     ELSE
- 3049                                                       QbeGen.CopyOp("0", q)
- 3050                                                     END
- 3051                                                   ELSE
- 3052                                                     IF t #
- 3053                                                        SymTab.InvalidType THEN
- 3054                                                       SemError(230)
- 3055                                                     END;
- 3056                                                     QbeGen.CopyOp("0", q)
- 3057                                                   END
- 3058                                                 END
- 3059                                               ELSIF (k = SymTab.KindVar)
- 3060                                                  OR (k = SymTab.KindParam) THEN
- 3061                                                 cls := SymTab.ClassOf(t);
- 3062                                                 IF (cls # SymTab.ClInt)
- 3063                                                    AND (cls # SymTab.ClBool)
- 3064                                                    AND (cls # SymTab.ClChar)
- 3065                                                    AND (cls # SymTab.ClUChar)
- 3066                                                    AND (cls # SymTab.ClEnum)
- 3067                                                    AND (cls # SymTab.ClReal)
- 3068                                                    AND (cls # SymTab.ClPtr)
- 3069                                                    AND (cls # SymTab.ClProc)
- 3070                                                    AND (cls # SymTab.ClLong)
- 3071                                                    AND (cls # SymTab.ClArray)
- 3072                                                    AND (cls # SymTab.ClSet)
- 3073                                                    AND (cls # SymTab.ClRecord)
- 3074                                                    AND (cls # SymTab.ClUStr)
- 3075                                                    AND (cls # SymTab.ClByte)
- 3076                                                    AND (cls # SymTab.ClSByte)
- 3077                                                    AND (cls # SymTab.ClWord16)
- 3078                                                    AND (cls # SymTab.ClSWord16)
- 3079                                                    AND (cls # SymTab.ClClass) THEN
- 3080                                                   SemError(230);
- 3081                                                   QbeGen.CopyOp("0", q)
- 3082                                                 ELSE QbeGen.CopyOp("@", q)
- 3083                                                 END
- 3084                                               ELSE QbeGen.CopyOp("0", q);
- 3085                                                 IF k = SymTab.KindImport THEN
- 3086                                                   SemError(230)
- 3087                                                 ELSIF k =
- 3088                                                    SymTab.KindProc THEN
- 3089                                                   (* bare procedure name:
- 3090                                                      a following ArgList
- 3091                                                      makes it a call;
- 3092                                                      otherwise Fact
- 3093                                                      reports 230 *)
- 3094                                                 ELSE
- 3095                                                    IF k = SymTab.KindField THEN
- 3096                                                      IF QbeGen.TopWith(qb) THEN
- 3097                                                        sfx := TRUE
- 3098                                                      ELSE SemError(230);
- 3099                                                        QbeGen.CopyOp("0", q)
- 3100                                                      END
- 3101                                                    END
- 3102                                                 END
- 3103                                               END
- 3104                                             END; .)
- 3105        (. astDes := AST.MakeNode(AST.NkDesignator);
- 3106           AST.SetChild(astDes, AST.NChild(astDes), AST.MakeLeaf(AST.NkIdent, n)); .)
- 3107        { "[" Expr<it, iq>
- 3108                                          (. AST.SetChild(astDes, AST.NChild(astDes),
- 3109               AST.MakeUn(AST.NkSelector, AST.SelIndex, astCur)); IF t = SymTab.InvalidType THEN
- 3110                                             ELSIF SymTab.ClassOf(t) #
- 3111                                                   SymTab.ClArray THEN
- 3112                                               SemError(217);
- 3113                                               t := SymTab.InvalidType
- 3114                                             ELSIF NOT SymTab.IsIntFamily(it)
- 3115   AND (SymTab.ClassOf(it) #
- 3116                                                   SymTab.ClChar)
- 3117   AND (SymTab.ClassOf(it) #
- 3118                                                   SymTab.ClEnum)
- 3119   AND (SymTab.ClassOf(it) #
- 3120                                                   SymTab.ClBool) THEN
- 3121                                               SemError(218);
- 3122                                               t := SymTab.InvalidType
- 3123                                              ELSE
- 3124                                                eT := SymTab.ArrayElem(t);
- 3125                                                t := eT; sfx := TRUE
- 3126                                              END; .)
- 3127          { "," Expr<it, iq>
- 3128                                          (. AST.SetChild(astDes, AST.NChild(astDes),
- 3129               AST.MakeUn(AST.NkSelector, AST.SelIndex, astCur)); IF t = SymTab.InvalidType THEN
- 3130                                             ELSIF SymTab.ClassOf(t) #
- 3131                                                   SymTab.ClArray THEN
- 3132                                               SemError(217);
- 3133                                               t := SymTab.InvalidType
- 3134                                             ELSIF NOT SymTab.IsIntFamily(it)
- 3135   AND (SymTab.ClassOf(it) #
- 3136                                                   SymTab.ClChar)
- 3137   AND (SymTab.ClassOf(it) #
- 3138                                                   SymTab.ClEnum)
- 3139   AND (SymTab.ClassOf(it) #
- 3140                                                   SymTab.ClBool) THEN
- 3141                                               SemError(218);
- 3142                                               t := SymTab.InvalidType
- 3143                                              ELSE
- 3144                                                eT := SymTab.ArrayElem(t);
- 3145                                                t := eT; sfx := TRUE
- 3146                                              END; .) }
- 3147          "]"
- 3148        | "." GetIdent<fn>
- 3149                                          (. astSel := AST.MakeNode(AST.NkSelector);
- 3150               AST.SetOp(astSel, AST.SelField);
- 3151               AST.SetChild(astSel, 0, AST.MakeLeaf(AST.NkIdent, fn));
- 3152               AST.SetChild(astDes, AST.NChild(astDes), astSel); IF k = SymTab.KindModule THEN
- 3153                                               (* qualified L.x: materialize
- 3154                                                  the export, then load it *)
- 3155                                               IF NOT SymTab.MaterializeAlias(n,
- 3156                                                    fn, mal) THEN
- 3157                                                 SemError(201);
- 3158                                                 t := SymTab.InvalidType;
- 3159                                                 QbeGen.CopyOp("0", q)
- 3160                                               ELSE
- 3161                                                 QbeGen.CopyOp(mal, qn);
- 3162                                                 t := SymTab.SymType(mal);
- 3163                                                 k := SymTab.SymKind(mal);
- 3164                                                 sfx := FALSE;
- 3165                                                 IF k = SymTab.KindProc THEN
- 3166                                                   (* call: ArgList supplies
- 3167                                                      the value *)
- 3168                                                   QbeGen.CopyOp("0", q)
- 3169                                                 ELSIF k = SymTab.KindConst THEN
- 3170                                                   IF SymTab.GetSymVal(mal,
- 3171                                                      cv)
- 3172                                                   THEN QbeGen.CopyOp(cv, q)
- 3173                                                   ELSE QbeGen.CopyOp("0", q)
- 3174                                                   END
- 3175                                                  END
- 3176                                               END
- 3177                                             ELSIF t = SymTab.InvalidType THEN
- 3178                                             ELSIF (SymTab.ClassOf(t) #
- 3179                                                    SymTab.ClRecord)
- 3180   AND (SymTab.ClassOf(t) #
- 3181                                                   SymTab.ClClass) THEN
- 3182                                               SemError(215);
- 3183                                               t := SymTab.InvalidType
- 3184                                             ELSIF (SymTab.ClassOf(t) =
- 3185                                                    SymTab.ClClass)
- 3186    AND SymTab.MethodExists(t, fn) THEN
- 3187                                               (* obj.Method: bind the
- 3188                                                  method and pass obj as
- 3189                                                  the hidden receiver; q
- 3190                                                  already holds the
- 3191                                                  object's address *)
- 3192                                               QbeGen.CopyOp(fn, n);
- 3193                                               QbeGen.CopyOp(fn, qn);
- 3194                                               methCls := t;
- 3195                                               k := SymTab.KindProc;
- 3196                                               t := SymTab.InvalidType
- 3197                                             ELSIF NOT SymTab.FieldExists(t,
- 3198                                                      fn) THEN
- 3199                                               SemError(216);
- 3200                                               t := SymTab.InvalidType
- 3201                                              ELSE
- 3202                                                t := SymTab.FieldType(t, fn);
- 3203                                                sfx := TRUE
- 3204                                              END; .)
- 3205        | "^"
- 3206                                          (. astSel := AST.MakeNode(AST.NkSelector);
- 3207               AST.SetOp(astSel, AST.SelDeref);
- 3208               AST.SetChild(astDes, AST.NChild(astDes), astSel); IF t = SymTab.InvalidType THEN
- 3209                                             ELSIF SymTab.ClassOf(t) #
- 3210                                                   SymTab.ClPtr THEN
- 3211                                               SemError(219);
- 3212                                               t := SymTab.InvalidType
- 3213                                             ELSE
- 3214                                               bt := SymTab.PtrBase(t);
- 3215                                               IF bt = SymTab.InvalidType THEN
- 3216                                               ELSE
- 3217                                                  t := bt;
- 3218                                                  sfx := TRUE
- 3219                                                END
- 3220                                             END; .) } (. astCur := astDes; .) .
- 3221    (* Result suffix (ISO component after a function call): `F()^`,
- 3222       `F()[i]`, `F().field`.  The call result is in t/q with sfx FALSE
- 3223       (a value, or a descriptor address for aggregates); each component
- 3224       descends one level exactly like the Design components. *)
- 3225    ResultComp<VAR t: SymTab.TypeIndex; VAR q: QbeGen.QVal;
- 3226               VAR sfx: BOOLEAN; VAR node: AST.Node;
- 3227               VAR mname: SymTab.Name; VAR methCls: SymTab.TypeIndex;
- 3228               VAR isM: BOOLEAN>          (. VAR it, eT, bt: SymTab.TypeIndex;
- 3229                                               iq, ql, qlo, qhi, qe, qb:
- 3230                                                 QbeGen.QVal;
- 3231                                               lo, hi, fo: INTEGER;
- 3232                                               isOpen: BOOLEAN;
- 3233                                               fname: SymTab.Name;
- 3234                                               astWrap, astSel: AST.Node; .)
- 3235      = "[" Expr<it, iq>
- 3236                                          (. isM := FALSE;
- 3237                                             IF AST.Kind(node) # AST.NkDesignator THEN
- 3238                                               astWrap := AST.MakeNode(
- 3239                                                 AST.NkDesignator);
- 3240                                               AST.SetChild(astWrap, 0, node);
- 3241                                               node := astWrap
- 3242                                             END;
- 3243                                             AST.SetChild(node, AST.NChild(node),
- 3244                                               AST.MakeUn(AST.NkSelector,
- 3245                                                 AST.SelIndex, astCur)); IF t = SymTab.InvalidType THEN
- 3246                                             ELSIF SymTab.ClassOf(t) #
- 3247                                                   SymTab.ClArray THEN
- 3248                                               SemError(217);
- 3249                                               t := SymTab.InvalidType
- 3250                                             ELSIF NOT SymTab.IsIntFamily(it)
- 3251    AND (SymTab.ClassOf(it) # SymTab.ClChar)
- 3252    AND (SymTab.ClassOf(it) # SymTab.ClEnum)
- 3253    AND (SymTab.ClassOf(it) # SymTab.ClBool) THEN
- 3254                                               SemError(218);
- 3255                                               t := SymTab.InvalidType
- 3256                                              ELSE
- 3257                                                eT := SymTab.ArrayElem(t);
- 3258                                                t := eT; sfx := TRUE
- 3259                                              END; .)
- 3260        "]"
- 3261      | "." GetIdent<fname>
- 3262                                          (. isM := FALSE;
- 3263                                             IF AST.Kind(node) # AST.NkDesignator THEN
- 3264                                               astWrap := AST.MakeNode(
- 3265                                                 AST.NkDesignator);
- 3266                                               AST.SetChild(astWrap, 0, node);
- 3267                                               node := astWrap
- 3268                                             END;
- 3269                                             AST.SetChild(node, AST.NChild(node),
- 3270                                               AST.MakeUn(AST.NkSelector,
- 3271                                                 AST.SelField,
- 3272                                                 AST.MakeLeaf(AST.NkIdent,
- 3273                                                   fname))); IF t = SymTab.InvalidType THEN
- 3274                                             ELSIF (SymTab.ClassOf(t) #
- 3275                                                    SymTab.ClRecord)
- 3276    AND (SymTab.ClassOf(t) # SymTab.ClClass) THEN
- 3277                                               SemError(215);
- 3278                                               t := SymTab.InvalidType
- 3279                                              ELSIF (SymTab.ClassOf(t) =
- 3280                                                     SymTab.ClClass)
- 3281    AND SymTab.MethodExists(t, fname) THEN
- 3282                                                (* a method on the call result:
- 3283                                                   a following ArgList makes
- 3284                                                   the call *)
- 3285                                                mname := fname;
- 3286                                                methCls := t; isM := TRUE;
- 3287                                                t := SymTab.InvalidType
- 3288                                             ELSIF NOT SymTab.FieldExists(t,
- 3289                                                      fname) THEN
- 3290                                               SemError(216);
- 3291                                               t := SymTab.InvalidType
- 3292                                              ELSE
- 3293                                                t := SymTab.FieldType(t, fname);
- 3294                                                sfx := TRUE
- 3295                                              END; .)
- 3296      | "^"                               (. isM := FALSE;
- 3297                                             IF AST.Kind(node) # AST.NkDesignator THEN
- 3298                                               astWrap := AST.MakeNode(
- 3299                                                 AST.NkDesignator);
- 3300                                               AST.SetChild(astWrap, 0, node);
- 3301                                               node := astWrap
- 3302                                             END;
- 3303                                             astSel := AST.MakeNode(AST.NkSelector);
- 3304                                             AST.SetOp(astSel, AST.SelDeref);
- 3305                                             AST.SetChild(node,
- 3306                                               AST.NChild(node), astSel); IF t = SymTab.InvalidType THEN
- 3307                                             ELSIF SymTab.ClassOf(t) #
- 3308                                                   SymTab.ClPtr THEN
- 3309                                               SemError(219);
- 3310                                               t := SymTab.InvalidType
- 3311                                             ELSE
- 3312                                               bt := SymTab.PtrBase(t);
- 3313                                               IF bt # SymTab.InvalidType THEN
- 3314                                                  t := bt; sfx := TRUE
- 3315                                               END
- 3316                                             END; .) .
- 3317    Expr<VAR t: SymTab.TypeIndex; VAR q: QbeGen.QVal>
- 3318                                          (. VAR t2: SymTab.TypeIndex;
- 3319                                               op: INTEGER;
- 3320                                               q2, qt, wl: QbeGen.QVal;
- 3321                                                astA, astB: AST.Node;
- 3322                                                astOp: INTEGER;
- 3323                                                astMade: BOOLEAN;
- 3324                                               isR: BOOLEAN;
- 3325                                               v1, v2: INTEGER;
- 3326                                               b: BOOLEAN; .)
- 3327      = SimExpr<t, q>                     (. astA := astCur; astMade := FALSE; .)
- 3328        [ Rel<op> SimExpr<t2, q2>
- 3329          (. astB := astCur; astMade := TRUE;
- 3330              astOp := AST.OpEq;
- 3331              IF op = SymTab.OpNeq1 THEN astOp := AST.OpNe
- 3332              ELSIF op = SymTab.OpNeq2 THEN astOp := AST.OpNe
- 3333              ELSIF op = SymTab.OpLt THEN astOp := AST.OpLt
- 3334              ELSIF op = SymTab.OpLe THEN astOp := AST.OpLe
- 3335              ELSIF op = SymTab.OpGt THEN astOp := AST.OpGt
- 3336              ELSIF op = SymTab.OpGe THEN astOp := AST.OpGe
- 3337              ELSIF op = SymTab.OpIn THEN astOp := AST.OpIn
- 3338              END;
- 3339              IF op = SymTab.OpIn THEN
- 3340               IF SymTab.InCheck(t, t2) THEN
- 3341                 IF (t = SymTab.InvalidType)
- 3342                    OR (t2 = SymTab.InvalidType) THEN
- 3343                   t := SymTab.BoolType(); QbeGen.CopyOp("0", q)
- 3344                 ELSE
- 3345                    t := SymTab.BoolType(); QbeGen.CopyOp("@", q)
- 3346                 END
- 3347               ELSE SemError(222); t := SymTab.InvalidType;
- 3348                 QbeGen.CopyOp("0", q)
- 3349               END
- 3350             ELSIF SymTab.RelCheck(t, t2, op) THEN
- 3351               IF (t = SymTab.InvalidType)
- 3352                  OR (t2 = SymTab.InvalidType) THEN
- 3353                 t := SymTab.BoolType(); QbeGen.CopyOp("0", q)
- 3354               ELSIF SymTab.IsOrdinal(t) AND SymTab.IsOrdinal(t2)
- 3355                  AND QbeGen.IsImm(q) AND QbeGen.IsImm(q2)
- 3356                  AND SymTab.ConstInt(q, v1)
- 3357                  AND SymTab.ConstInt(q2, v2) THEN
- 3358                 (* fold a relation of two ordinal constants (needed for
- 3359                    ORD(boolean) in a CONST initialiser) *)
- 3360                 IF op = SymTab.OpEq THEN b := v1 = v2
- 3361                 ELSIF (op = SymTab.OpNeq1) OR (op = SymTab.OpNeq2) THEN
- 3362                   b := v1 # v2
- 3363                 ELSIF op = SymTab.OpLt THEN b := v1 < v2
- 3364                 ELSIF op = SymTab.OpLe THEN b := v1 <= v2
- 3365                 ELSIF op = SymTab.OpGt THEN b := v1 > v2
- 3366                 ELSE b := v1 >= v2
- 3367                 END;
- 3368                 t := SymTab.BoolType();
- 3369                 IF b THEN QbeGen.CopyOp("1", q)
- 3370                 ELSE QbeGen.CopyOp("0", q)
- 3371                 END
- 3372               ELSIF (SymTab.ClassOf(t) = SymTab.ClPtr)
- 3373                  OR (SymTab.ClassOf(t2) = SymTab.ClPtr) THEN
- 3374                 IF (op # SymTab.OpEq) AND (op # SymTab.OpNeq1)
- 3375   AND (op # SymTab.OpNeq2) THEN
- 3376                   SemError(213); t := SymTab.InvalidType;
- 3377                   QbeGen.CopyOp("0", q)
- 3378                  ELSE
- 3379                    t := SymTab.BoolType(); QbeGen.CopyOp("@", q)
- 3380                  END
- 3381                ELSIF (SymTab.ClassOf(t) = SymTab.ClSet)
- 3382                   OR (SymTab.ClassOf(t2) = SymTab.ClSet) THEN
- 3383                  t := SymTab.BoolType(); QbeGen.CopyOp("@", q)
- 3384               ELSIF SymTab.StrCompat(t, t2) THEN
- 3385                 QbeGen.StrEq(op, q, q2, qt);
- 3386                 t := SymTab.BoolType(); QbeGen.CopyOp(qt, q)
- 3387               ELSIF SymTab.IsLongFamily(t)
- 3388                  OR SymTab.IsLongFamily(t2) THEN
- 3389                  t := SymTab.BoolType(); QbeGen.CopyOp("@", q)
- 3390                ELSE
- 3391                  t := SymTab.BoolType();
- 3392                  QbeGen.CopyOp("@", q)
- 3393                END
- 3394             ELSE SemError(213); t := SymTab.InvalidType;
- 3395                QbeGen.CopyOp("0", q)
- 3396              END;
- 3397              astCur := AST.MakeBin(AST.NkBinExpr, astOp, astA, astB); .) ]
- 3398         (. IF NOT astMade THEN astCur := astA END; .)
- 3399             (. IF astCur # AST.NoNode THEN AST.SetTy(astCur, t) END; .) .
- 3400    Rel<VAR op: INTEGER>
- 3401      = "="                               (. op := SymTab.OpEq; .)
- 3402      | "#"                               (. op := SymTab.OpNeq1; .)
- 3403      | "<"                               (. op := SymTab.OpLt; .)
- 3404      | "<="                              (. op := SymTab.OpLe; .)
- 3405      | ">"                               (. op := SymTab.OpGt; .)
- 3406      | ">="                              (. op := SymTab.OpGe; .)
- 3407      | "IN"                              (. op := SymTab.OpIn; .) .
- 3408    SimExpr<VAR t: SymTab.TypeIndex; VAR q: QbeGen.QVal>
- 3409                                          (. VAR t2, res2, lt, rt:
- 3410                                                 SymTab.TypeIndex;
- 3411                                               op: INTEGER;
- 3412                                               q2, qt, wq, qf, q2a, q2b:
- 3413                                                 QbeGen.QVal;
- 3414                                               neg, isR, isL, folded:
- 3415                                                 BOOLEAN;
- 3416                                               fok: BOOLEAN;
- 3417                                               lw, rw, mw: CARDINAL;
- 3418                                               lTrue, lNext, lDone, qr, qs: QbeGen.QVal;
- 3419                                                astA, astB: AST.Node;
- 3420                                                astSign, astOp: INTEGER;
- 3421                                                v1, v2: INTEGER;
- 3422                                                s: ARRAY [0 .. 255] OF CHAR; .)
- 3423      =                                   (. neg := FALSE; astSign := 0; .)
- 3424        [ "+"                         (. neg := TRUE; astSign := 1; .)
- 3425        | "-"                         (. neg := TRUE; astSign := -1; .) ]
- 3426        Term<t, q> (. astA := astCur;
- 3427                                            IF neg AND QbeGen.IsImm(q) THEN
- 3428                                              QbeGen.NegFold(q, q)
- 3429                                            END;
- 3430                                           IF astSign < 0 THEN
- 3431                                             astCur := AST.MakeUn(
- 3432                                               AST.NkUnary, AST.OpSub, astA);
- 3433                                             astA := astCur
- 3434                                           END; .)
- 3435         { AddOp<op>
- 3436           Term<t2, q2> (. astB := astCur; .)
- 3437          (. astOp := AST.OpAdd;
- 3438             IF op = SymTab.OpSub THEN astOp := AST.OpSub
- 3439             ELSIF op = SymTab.OpOr THEN astOp := AST.OpOr END;
- 3440             astA := AST.MakeBin(AST.NkBinExpr, astOp, astA, astB);
- 3441             astCur := astA;
- 3442             IF op = SymTab.OpOr THEN
- 3443               (* short-circuit: if q is true the RHS is skipped *)
- 3444               IF SymTab.BoolCheck(t) AND SymTab.BoolCheck(t2) THEN
- 3445                 t := SymTab.BoolType()
- 3446               ELSE SemError(212); t := SymTab.InvalidType END;
- 3447                IF t # SymTab.InvalidType THEN
- 3448                  QbeGen.CopyOp("@", q)
- 3449                ELSE QbeGen.CopyOp("0", q)
- 3450                END
- 3451             ELSIF (op = SymTab.OpAdd)
- 3452               AND (SymTab.ClassOf(t) = SymTab.ClChar)
- 3453               AND (SymTab.ClassOf(t2) = SymTab.ClChar)
- 3454               AND QbeGen.IsImm(q) AND QbeGen.IsImm(q2) THEN
- 3455               (* "W" + "o": two one-character string literals concatenate
- 3456                  to a two-character string (they are CHAR-typed immediates) *)
- 3457               IF SymTab.ConstInt(q, v1) AND SymTab.ConstInt(q2, v2)
- 3458                  AND (v1 >= 0) AND (v1 <= 255)
- 3459                  AND (v2 >= 0) AND (v2 <= 255) THEN
- 3460                 s[0] := '"'; s[1] := CHR(v1); s[2] := CHR(v2);
- 3461                 s[3] := '"'; s[4] := CHR(0);
- 3462                 QbeGen.DeclStr(s, qt); QbeGen.CopyOp(qt, q);
- 3463                 t := SymTab.NewStr();
- 3464                 astA := AST.MakeLeaf(AST.NkStrLit, s);
- 3465                 astCur := astA
- 3466               ELSE SemError(211); t := SymTab.InvalidType;
- 3467                 QbeGen.CopyOp("0", q)
- 3468               END
- 3469             ELSIF (op = SymTab.OpAdd)
- 3470               AND (SymTab.UStrCompat(t, t2)
- 3471                 OR ((SymTab.ClassOf(t) = SymTab.ClUChar)
- 3472                   AND (SymTab.ClassOf(t2) = SymTab.ClUStr))
- 3473                 OR ((SymTab.ClassOf(t) = SymTab.ClUStr)
- 3474                   AND (SymTab.ClassOf(t2) = SymTab.ClUChar))
- 3475                 OR ((SymTab.ClassOf(t) = SymTab.ClUChar)
- 3476                   AND (SymTab.ClassOf(t2) = SymTab.ClUChar))) THEN
- 3477               (* UString concatenation: a UCHAR operand becomes a
- 3478                  1-codepoint UString; the result is a descriptor in the
- 3479                  shim's concat buffer.  Work on copies so neither
- 3480                  operand is clobbered. *)
- 3481                t := SymTab.NewUStr();
- 3482                QbeGen.CopyOp("@", q)
- 3483             ELSIF (op = SymTab.OpAdd)
- 3484               AND (SymTab.StrCompat(t, t2)
- 3485                 OR (SymTab.IsStrType(t)
- 3486                   AND (SymTab.ClassOf(t2) = SymTab.ClChar))
- 3487                 OR ((SymTab.ClassOf(t) = SymTab.ClChar)
- 3488                   AND SymTab.IsStrType(t2))) THEN
- 3489               (* string concatenation; a CHAR operand becomes a
- 3490                  1-character string literal.  When both operands are
- 3491                  constants, fold to a single string literal so a
- 3492                  constructor element stays compile-time. *)
- 3493                QbeGen.StrFold(q, q2, SymTab.ClassOf(t), SymTab.ClassOf(t2),
- 3494                  qt, fok);
- 3495                IF fok THEN QbeGen.CopyOp(qt, q)
- 3496                ELSE QbeGen.CopyOp("@", q)
- 3497                END;
- 3498                t := SymTab.NewStr()
- 3499             ELSIF (t # SymTab.InvalidType) AND (t2 # SymTab.InvalidType)
- 3500   AND (SymTab.ClassOf(t) = SymTab.ClSet)
- 3501   AND (SymTab.ClassOf(t2) = SymTab.ClSet) THEN
- 3502                lw := SymTab.SetWords(t); rw := SymTab.SetWords(t2);
- 3503                mw := lw;
- 3504                IF rw > mw THEN mw := rw END;
- 3505                t := SymTab.NewSet(
- 3506                       SymTab.NewSubR(0,
- 3507                         VAL(INTEGER, mw) * 32 - 1));
- 3508                QbeGen.CopyOp("@", q)
- 3509             ELSE
- 3510               IF SymTab.ArithCheck(t, t2, FALSE, res2) THEN
- 3511                 lt := t; rt := t2; t := res2
- 3512               ELSE SemError(211); t := SymTab.InvalidType END;
- 3513               IF t # SymTab.InvalidType THEN
- 3514                 isL := SymTab.IsLongFamily(t);
- 3515                 isR := SymTab.ClassOf(t) = SymTab.ClReal;
- 3516                 folded := FALSE;
- 3517                 IF (NOT isL) AND (NOT isR)
- 3518    AND QbeGen.IsImm(q) AND QbeGen.IsImm(q2) THEN
- 3519                   IF op = SymTab.OpAdd THEN
- 3520                     folded := QbeGen.Fold2(0, q, q2, qf)
- 3521                   ELSE
- 3522                     folded := QbeGen.Fold2(1, q, q2, qf)
- 3523                   END
- 3524                 END;
- 3525                 IF folded THEN QbeGen.CopyOp(qf, q)
- 3526                  ELSE
- 3527                  QbeGen.CopyOp("@", q)
- 3528                  END
- 3529               ELSE QbeGen.CopyOp("0", q)
- 3530               END
- 3531             END; .) }
- 3532             (. IF astCur # AST.NoNode THEN AST.SetTy(astCur, t) END; .) .
- 3533    AddOp<VAR op: INTEGER>
- 3534      = "+"                               (. op := SymTab.OpAdd; .)
- 3535      | "-"                               (. op := SymTab.OpSub; .)
- 3536      | "OR"                              (. op := SymTab.OpOr; .) .
- 3537    Term<VAR t: SymTab.TypeIndex; VAR q: QbeGen.QVal>
- 3538                                          (. VAR t2, res2, lt, rt:
- 3539                                                 SymTab.TypeIndex;
- 3540                                               op: INTEGER;
- 3541                                               q2, qt, wq, qf:
- 3542                                                 QbeGen.QVal;
- 3543                                               isR, isL, folded: BOOLEAN;
- 3544                                               lw, rw, mw: CARDINAL;
- 3545                                               lNext, lFalse, lDone, qr, qs: QbeGen.QVal;
- 3546                                                astA, astB: AST.Node;
- 3547                                                astOp: INTEGER; .)
- 3548      = Fact<t, q> (. astA := astCur; .) { MulOp<op>
- 3549          Fact<t2, q2> (. astB := astCur; .)
- 3550        (. astOp := AST.OpMul;
- 3551           IF op = SymTab.OpSlash THEN astOp := AST.OpDiv
- 3552           ELSIF op = SymTab.OpDiv THEN astOp := AST.OpDiv
- 3553           ELSIF op = SymTab.OpMod THEN astOp := AST.OpMod
- 3554           ELSIF op = SymTab.OpAnd THEN astOp := AST.OpAnd END;
- 3555           astA := AST.MakeBin(AST.NkBinExpr, astOp, astA, astB);
- 3556           astCur := astA;
- 3557           IF op = SymTab.OpAnd THEN
- 3558             (* short-circuit: if q is false the RHS is skipped *)
- 3559             IF SymTab.BoolCheck(t) AND SymTab.BoolCheck(t2) THEN
- 3560               t := SymTab.BoolType()
- 3561             ELSE SemError(212); t := SymTab.InvalidType END;
- 3562              IF t # SymTab.InvalidType THEN QbeGen.CopyOp("@", q)
- 3563              ELSE QbeGen.CopyOp("0", q)
- 3564              END
- 3565           ELSIF (t # SymTab.InvalidType) AND (t2 # SymTab.InvalidType)
- 3566   AND (SymTab.ClassOf(t) = SymTab.ClSet)
- 3567   AND (SymTab.ClassOf(t2) = SymTab.ClSet) THEN
- 3568              lw := SymTab.SetWords(t); rw := SymTab.SetWords(t2);
- 3569              mw := lw;
- 3570              IF rw > mw THEN mw := rw END;
- 3571              t := SymTab.NewSet(
- 3572                     SymTab.NewSubR(0,
- 3573                       VAL(INTEGER, mw) * 32 - 1));
- 3574              QbeGen.CopyOp("@", q)
- 3575           ELSE
- 3576             IF SymTab.ArithCheck(t, t2,
- 3577                  (op = SymTab.OpDiv) OR (op = SymTab.OpMod),
- 3578                  res2) THEN
- 3579               lt := t; rt := t2; t := res2
- 3580             ELSE SemError(211); t := SymTab.InvalidType END;
- 3581             IF t # SymTab.InvalidType THEN
- 3582               isL := SymTab.IsLongFamily(t);
- 3583               isR := SymTab.ClassOf(t) = SymTab.ClReal;
- 3584               folded := FALSE;
- 3585               IF (NOT isL) AND (NOT isR)
- 3586    AND QbeGen.IsImm(q) AND QbeGen.IsImm(q2) THEN
- 3587                 IF op = SymTab.OpTimes THEN
- 3588                   folded := QbeGen.Fold2(2, q, q2, qf)
- 3589                 ELSIF op = SymTab.OpDiv THEN
- 3590                   folded := QbeGen.Fold2(3, q, q2, qf)
- 3591                 ELSIF op = SymTab.OpMod THEN
- 3592                   folded := QbeGen.Fold2(4, q, q2, qf)
- 3593                 END
- 3594               END;
- 3595               IF folded THEN QbeGen.CopyOp(qf, q)
- 3596                ELSE
- 3597                QbeGen.CopyOp("@", q)
- 3598                END
- 3599             ELSE QbeGen.CopyOp("0", q)
- 3600             END
- 3601           END; .) }
- 3602             (. IF astCur # AST.NoNode THEN AST.SetTy(astCur, t) END; .) .
- 3603    MulOp<VAR op: INTEGER>
- 3604      = "*"                               (. op := SymTab.OpTimes; .)
- 3605      | "/"                               (. op := SymTab.OpSlash; .)
- 3606      | "DIV"                             (. op := SymTab.OpDiv; .)
- 3607      | "MOD"                             (. op := SymTab.OpMod; .)
- 3608      | ( "AND" | "&" )                   (. op := SymTab.OpAnd; .) .
- 3609    Fact<VAR t: SymTab.TypeIndex; VAR q: QbeGen.QVal>
- 3610                                          (. VAR s: ARRAY [0 .. 255] OF CHAR;
- 3611                                               et, dt, t2, st, ct2, et2:
- 3612                                                 SymTab.TypeIndex;
- 3613                                               dk: INTEGER;
- 3614                                               qd, q2, sq, qa, qm0, qr, qt:
- 3615                                                 QbeGen.QVal;
- 3616                                               qn, vn: SymTab.Name;
- 3617                                               vt: SymTab.TypeIndex;
- 3618                                               c1, c2: INTEGER;
- 3619                                               lo, hi: INTEGER;
- 3620                                               isMax: BOOLEAN;
- 3621                                               called, isHigh, sfx, isCh,
- 3622                                               isU, uok, isStr: BOOLEAN;
- 3623                                               ucp: INTEGER; astIsLit: BOOLEAN;
- 3624                                                astD: AST.Node;
- 3625                                                astCall: BOOLEAN;
- 3626                                                astNode, astNot: AST.Node;
- 3627                                                j: CARDINAL;
- 3628                                                astArg2: AST.Node;
- 3629                                                astBrace: AST.Node;
- 3630                                                astRes: AST.Node; mname: SymTab.Name; isM: BOOLEAN;
- 3631                                                isConvF: BOOLEAN;
- 3632                                                fi, fj: CARDINAL; .)
- 3633      = (. astIsLit := FALSE; .)
- 3634      ( "__LINE__"                        (. QbeGen.IntStr(M2S.line, q);
- 3635                                             astIsLit := TRUE;
- 3636                                             astCur := AST.MakeLeaf(
- 3637                                               AST.NkIntLit, q);
- 3638                                             t := SymTab.IntType(); .)
- 3639      | "__FUNCTION__"                    (. (* fold to the current procedure
- 3640                                                (module name at unit level) *)
- 3641                                             s[0] := '"'; fi := 1; fj := 0;
- 3642                                             IF curFun[0] = CHR(0) THEN
- 3643                                               WHILE (unitName[fj] # CHR(0))
- 3644                                                 AND (fi < HIGH(s)) DO
- 3645                                                 s[fi] := unitName[fj];
- 3646                                                 INC(fi); INC(fj)
- 3647                                               END
- 3648                                             ELSE
- 3649                                               WHILE (curFun[fj] # CHR(0))
- 3650                                                 AND (fi < HIGH(s)) DO
- 3651                                                 s[fi] := curFun[fj];
- 3652                                                 INC(fi); INC(fj)
- 3653                                               END
- 3654                                             END;
- 3655                                             s[fi] := '"';
- 3656                                             s[fi + 1] := CHR(0);
- 3657                                             astIsLit := TRUE;
- 3658                                             astCur := AST.MakeLeaf(
- 3659                                               AST.NkStrLit, s);
- 3660                                             t := SymTab.NewStr();
- 3661                                             QbeGen.DeclStr(s, q); .)
- 3662      | "__FILE__"                        (. (* fold to the quoted file name *)
- 3663                                             s[0] := '"'; fi := 1; fj := 0;
- 3664                                             WHILE (M2S.fileName[fj] # CHR(0))
- 3665                                               AND (fi < HIGH(s)) DO
- 3666                                               s[fi] := M2S.fileName[fj];
- 3667                                               INC(fi); INC(fj)
- 3668                                             END;
- 3669                                             s[fi] := '"';
- 3670                                             s[fi + 1] := CHR(0);
- 3671                                             astIsLit := TRUE;
- 3672                                             astCur := AST.MakeLeaf(
- 3673                                               AST.NkStrLit, s);
- 3674                                             t := SymTab.NewStr();
- 3675                                             QbeGen.DeclStr(s, q); .)
- 3676      | integer                           (. LexString(s);
- 3677                                             QbeGen.NormInt(s, q); astIsLit := TRUE; astCur := AST.MakeLeaf(AST.NkIntLit, s);
- 3678                                             t := SymTab.IntType(); .)
- 3679      | charConst                         (. LexString(s);
- 3680                                             QbeGen.NormLit(s, q, isCh);
- 3681                                             astIsLit := TRUE;
- 3682                                             astCur := AST.MakeLeaf(
- 3683                                               AST.NkCharLit, s);
- 3684                                             t := SymTab.CharType(); .)
- 3685      | real                              (. LexString(s);
- 3686                                             QbeGen.NormReal(s, q);
- 3687                                             astIsLit := TRUE;
- 3688                                             astCur := AST.MakeLeaf(
- 3689                                               AST.NkRealLit, s);
- 3690                                             t := SymTab.RealType(); .)
- 3691      | string                            (. LexString(s);
- 3692                                             astIsLit := TRUE;
- 3693                                             astCur := AST.MakeLeaf(
- 3694                                               AST.NkStrLit, s);
- 3695                                             IF SymTab.StrLen(s) = 3 THEN
- 3696                                               t := SymTab.CharType();
- 3697                                               QbeGen.IntStr(
- 3698                                                 QbeGen.CharVal(s), q)
- 3699                                             ELSIF SymTab.StrLen(s) = 2 THEN
- 3700                                               (* empty string: a string value
- 3701                                                  for arrays, 0 for CHAR *)
- 3702                                               t := SymTab.NewEmptyStr();
- 3703                                               QbeGen.DeclStr(s, q)
- 3704                                             ELSE t := SymTab.NewStr();
- 3705                                               QbeGen.DeclStr(s, q);
- 3706                                               (* a literal's value IS its
- 3707                                                  static descriptor address *)
- 3708                                             END; .)
- 3709      | ustring                           (. LexString(s);
- 3710                                             astIsLit := TRUE;
- 3711                                             astCur := AST.MakeLeaf(
- 3712                                               AST.NkStrLit, s);
- 3713                                             QbeGen.DeclUStr(s, q, isU, ucp,
- 3714                                               uok);
- 3715                                             IF NOT uok THEN
- 3716                                               SemError(234);
- 3717                                               t := SymTab.InvalidType
- 3718                                             ELSIF isU THEN
- 3719                                               t := SymTab.UCharType();
- 3720                                               QbeGen.IntStr(ucp, q)
- 3721                                             ELSE
- 3722                                               t := SymTab.NewUStr();
- 3723                                             END; .)
- 3724      | Design<dt, dk, qd, qn, sfx>       (. astD := astCur; astCall := FALSE; astBrace := AST.NoNode;
- 3725                                             astNArgs := 0; called := FALSE;
- 3726                                             t := dt;
- 3727                                             IF dk = SymTab.KindConst THEN
- 3728                                               QbeGen.CopyOp(qd, q)
- 3729                                             ELSE QbeGen.CopyOp("@", q)
- 3730                                             END; .)
- 3731        [ TypedBraceLit<dt, q>            (. t := dt; astCall := TRUE;
- 3732                                               astBrace := astCur; .) ]
- 3733        [ ArgList<qn, dt, qd, TRUE, FALSE, methCls, ct2, q2, called>
- 3734                                          (. astCall := TRUE;
- 3735                                             IF (SymTab.SymKind(qn) = SymTab.KindType)
- 3736    OR (SymTab.SymKind(qn) = SymTab.KindPredef) THEN
- 3737                                             (* T(x): emit as the VAL builtin so Lower's
- 3738                                                conversion rules apply unchanged *)
- 3739                                             astNode := AST.MakeNode(AST.NkCall);
- 3740                                             AST.SetChild(astNode, 0,
- 3741                                               AST.MakeLeaf(AST.NkIdent, "VAL"));
- 3742                                             AST.SetChild(astNode, 1,
- 3743                                               AST.MakeLeaf(AST.NkIdent, qn));
- 3744                                             IF astNArgs = 1 THEN
- 3745                                               AST.SetChild(astNode, 2, astArgs[0])
- 3746                                             END;
- 3747                                             isConvF := TRUE
- 3748                                             ELSE astNode := AstCallNode(astD)
- 3749                                             END;
- 3750                                             astRes := astNode;
- 3751                                             t := ct2;
- 3752                                             QbeGen.CopyOp(q2, q);
- 3753                                             IF isConvF AND QbeGen.IsImm(convQ)
- 3754                                                AND OrdClass(convT) AND OrdClass(ct2) THEN
- 3755                                               QbeGen.CopyOp(convQ, q)
- 3756                                             END;
- 3757                                             sfx := FALSE; .)
- 3758          { ResultComp<t, q, sfx, astRes, mname, methCls, isM>
- 3759            [ (. astNArgs := 0; .)
- 3760              ArgList<mname, t, q, TRUE, FALSE, methCls, ct2, q2, called>
- 3761                                          (. astNode := AstCallNode(astRes);
- 3762                                             astRes := astNode;
- 3763                                             t := ct2;
- 3764                                             QbeGen.CopyOp(q2, q);
- 3765                                             sfx := FALSE; .) ] }
- 3766                                          (. IF sfx THEN
- 3767                                               IF t = SymTab.InvalidType THEN
- 3768                                                 QbeGen.CopyOp("0", q)
- 3769                                               ELSIF (SymTab.ClassOf(t) #
- 3770                                                      SymTab.ClRecord)
- 3771    AND (SymTab.ClassOf(t) # SymTab.ClSet)
- 3772    AND (SymTab.ClassOf(t) # SymTab.ClArray)
- 3773    AND (SymTab.ClassOf(t) # SymTab.ClClass) THEN
- 3774                                                  QbeGen.CopyOp("@", q)
- 3775                                               END
- 3776                                             END; .) ]
- 3777                                          (. IF called THEN
- 3778                                               astCur := astRes
- 3779                                             ELSIF astCall THEN
- 3780                                               astCur := astBrace
- 3781                                             ELSE astCur := astD
- 3782                                             END;
- 3783                                              astIsLit := TRUE;
- 3784                                              IF NOT called
- 3785   AND (dk = SymTab.KindProc) THEN
- 3786                                               (* bare zero-arg function
- 3787                                                  call (parentheses may be
- 3788                                                  omitted); a proper or
- 3789                                                  parameterised proc here
- 3790                                                  is 230 *)
- 3791                                                IF (SymTab.ProcNPar(qn) = 0)
- 3792   AND (SymTab.ProcRes(qn) # SymTab.InvalidType) THEN
- 3793                                                  t := SymTab.ProcRes(qn);
- 3794                                                  QbeGen.CopyOp("@", q);
- 3795                                                  astCur := AST.MakeNode(AST.NkCall);
- 3796                                                  AST.SetChild(astCur, 0, astD)
- 3797                                                ELSE
- 3798                                                  t := SymTab.ProcTypeOf(qn);
- 3799                                                  QbeGen.CopyOp("@", q)
- 3800                                                END
- 3801                                             END; .)
- 3802      | ( "HIGH"                          (. isHigh := TRUE; .)
- 3803        | ( "LEN" | "LENGTH" )            (. isHigh := FALSE; .) )
- 3804        "(" ( Design<dt, dk, qd, qn, sfx> (. isStr := FALSE;
- 3805                                              isU := FALSE; .)
- 3806            | string                       (. LexString(s); astCur := AST.MakeLeaf(AST.NkStrLit, s);
- 3807                                              isStr := TRUE;
- 3808                                              isU := FALSE;
- 3809                                              IF SymTab.StrLen(s) = 3 THEN
- 3810                                                dt := SymTab.CharType();
- 3811                                                QbeGen.IntStr(QbeGen.CharVal(s),
- 3812                                                  qd)
- 3813                                              ELSE
- 3814                                                dt := SymTab.NewStr();
- 3815                                                QbeGen.DeclStr(s, qd);
- 3816                                              END;
- 3817                                              dk := -1;
- 3818                                              qn[0] := CHR(0); .)
- 3819            | ustring                      (. LexString(s); astCur := AST.MakeLeaf(AST.NkStrLit, s);
- 3820                                              QbeGen.DeclUStr(s, qd, isU, ucp,
- 3821                                                uok);
- 3822                                              isStr := FALSE;
- 3823                                              IF NOT uok THEN
- 3824                                                SemError(234);
- 3825                                                dt := SymTab.InvalidType
- 3826                                              ELSIF isU THEN
- 3827                                                (* one codepoint: a UCHAR;
- 3828                                                   LEN is 1, HIGH is 0 *)
- 3829                                                dt := SymTab.UCharType();
- 3830                                                QbeGen.IntStr(ucp, qd)
- 3831                                              ELSE
- 3832                                                dt := SymTab.NewUStr();
- 3833                                              END;
- 3834                                              dk := -1;
- 3835                                              qn[0] := CHR(0); .) )
- 3836        ")"
- 3837                                          (. astNode := AST.MakeNode(AST.NkCall);
- 3838     IF isHigh THEN AST.SetChild(astNode, 0,
- 3839       AST.MakeLeaf(AST.NkIdent, "HIGH"))
- 3840     ELSE AST.SetChild(astNode, 0,
- 3841       AST.MakeLeaf(AST.NkIdent, "LEN")) END;
- 3842     IF astCur # AST.NoNode THEN AST.SetChild(astNode, 1, astCur) END;
- 3843     astCur := astNode; astIsLit := TRUE;
- 3844                                             IF (dt # SymTab.InvalidType)
- 3845    AND (SymTab.ClassOf(dt) = SymTab.ClUStr) THEN
- 3846                                               (* UString: the count is
- 3847                                                  the descriptor header *)
- 3848                                                t := SymTab.IntType();
- 3849                                                QbeGen.CopyOp("@", q)
- 3850                                             ELSIF (dt # SymTab.InvalidType)
- 3851    AND (SymTab.ClassOf(dt) = SymTab.ClUChar) THEN
- 3852                                               (* single UCHAR codepoint *)
- 3853                                               IF isHigh THEN
- 3854                                                 QbeGen.CopyOp("0", qr)
- 3855                                               ELSE
- 3856                                                 QbeGen.CopyOp("1", qr)
- 3857                                               END;
- 3858                                               t := SymTab.IntType();
- 3859                                               QbeGen.CopyOp(qr, q)
- 3860                                             ELSIF isStr THEN
- 3861                                               (* fold: content length at
- 3862                                                  compile time *)
- 3863                                               IF SymTab.StrLen(s) = 3 THEN
- 3864                                                 c1 := 1
- 3865                                               ELSE
- 3866                                                 c1 :=
- 3867                                                   SymTab.StrLen(s) - 2
- 3868                                               END;
- 3869                                               IF isHigh THEN
- 3870                                                 DEC(c1)
- 3871                                               END;
- 3872                                               QbeGen.IntStr(c1, qr);
- 3873                                               t := SymTab.IntType();
- 3874                                               QbeGen.CopyOp(qr, q)
- 3875                                             ELSIF dt = SymTab.InvalidType THEN
- 3876                                               t := SymTab.InvalidType;
- 3877                                               QbeGen.CopyOp("0", q)
- 3878                                             ELSIF SymTab.ClassOf(dt) =
- 3879                                                   SymTab.ClStr THEN
- 3880                                               (* HIGH/LEN of a string
- 3881                                                  CONST: its pooled literal
- 3882                                                  knows its length *)
- 3883                                               IF QbeGen.StrLitLen(qd, c1) THEN
- 3884                                                 IF isHigh THEN DEC(c1) END;
- 3885                                                 QbeGen.IntStr(VAL(INTEGER, c1),
- 3886                                                   qr);
- 3887                                                 t := SymTab.IntType();
- 3888                                                 QbeGen.CopyOp(qr, q)
- 3889                                               ELSE SemError(217);
- 3890                                                 t := SymTab.InvalidType;
- 3891                                                 QbeGen.CopyOp("0", q)
- 3892                                               END
- 3893                                             ELSIF SymTab.ClassOf(dt) #
- 3894                                                   SymTab.ClArray THEN
- 3895                                               SemError(217);
- 3896                                               t := SymTab.InvalidType;
- 3897                                               QbeGen.CopyOp("0", q)
- 3898                                             ELSE
- 3899                                                IF SymTab.IsOpenArray(dt) THEN
- 3900                                                  t := SymTab.IntType();
- 3901                                                  QbeGen.CopyOp("@", q)
- 3902                                                ELSE
- 3903                                                  IF isHigh THEN
- 3904                                                    QbeGen.IntStr(
- 3905                                                      SymTab.ArrayHi(dt), qr)
- 3906                                                  ELSE
- 3907                                                    QbeGen.IntStr(VAL(
- 3908                                                      INTEGER,
- 3909                                                      SymTab.ArrayLen(dt)),
- 3910                                                      qr)
- 3911                                                  END;
- 3912                                                  t := SymTab.IntType();
- 3913                                                  QbeGen.CopyOp(qr, q)
- 3914                                                END
- 3915                                              END; .)
- 3916      | ( "SIZE" | "TSIZE" ) "(" Design<dt, dk, qd, qn, sfx> ")"
- 3917      (. astNode := AST.MakeNode(AST.NkCall);
- 3918     AST.SetChild(astNode, 0, AST.MakeLeaf(AST.NkIdent, "SIZE"));
- 3919     IF astCur # AST.NoNode THEN AST.SetChild(astNode, 1, astCur) END;
- 3920     astCur := astNode; astIsLit := TRUE; .)
- 3921                                          (. IF dt = SymTab.InvalidType THEN
- 3922                                               t := SymTab.InvalidType;
- 3923                                               QbeGen.CopyOp("0", q)
- 3924                                             ELSE
- 3925                                               QbeGen.IntStr(VAL(INTEGER,
- 3926                                                 SymTab.ObjectSize(dt)), q);
- 3927                                               t := SymTab.IntType()
- 3928                                             END; .)
- 3929      | ( "SHIFT"                         (. isMax := FALSE; .)
- 3930        | "ROTATE"                        (. isMax := TRUE; .) )
- 3931        "(" Expr<et, q> (. astArg2 := astCur; .) "," Expr<et2, q2> ")"
- 3932                                          (. astNode := AST.MakeNode(AST.NkCall);
- 3933     IF isMax THEN AST.SetChild(astNode, 0,
- 3934       AST.MakeLeaf(AST.NkIdent, "ROTATE"))
- 3935     ELSE AST.SetChild(astNode, 0,
- 3936       AST.MakeLeaf(AST.NkIdent, "SHIFT")) END;
- 3937     IF astArg2 # AST.NoNode THEN AST.SetChild(astNode, 1, astArg2) END;
- 3938     IF astCur # AST.NoNode THEN AST.SetChild(astNode, 2, astCur) END;
- 3939     astCur := astNode; astIsLit := TRUE;
- 3940                                             (* set shift/rotate: isMax
- 3941                                                doubles as "rotate" *)
- 3942                                             IF (et # SymTab.InvalidType)
- 3943                                                AND (SymTab.ClassOf(et) =
- 3944                                                   SymTab.ClSet) THEN
- 3945                                                t := et;
- 3946                                                QbeGen.CopyOp("@", q)
- 3947                                             ELSE SemError(230);
- 3948                                               t := SymTab.InvalidType;
- 3949                                               QbeGen.CopyOp("0", q)
- 3950                                             END; .)
- 3951      | ( "MIN"                           (. isMax := FALSE; .)
- 3952        | "MAX"                           (. isMax := TRUE; .) )
- 3953        "(" Design<dt, dk, qd, qn, sfx> ")"
- 3954                                          (. astNode := AST.MakeNode(AST.NkCall);
- 3955     IF isMax THEN AST.SetChild(astNode, 0,
- 3956       AST.MakeLeaf(AST.NkIdent, "MAX"))
- 3957     ELSE AST.SetChild(astNode, 0,
- 3958       AST.MakeLeaf(AST.NkIdent, "MIN")) END;
- 3959     IF astCur # AST.NoNode THEN AST.SetChild(astNode, 1, astCur) END;
- 3960     astCur := astNode; astIsLit := TRUE;
- 3961                                             IF (dt # SymTab.InvalidType)
- 3962   AND (SymTab.ClassOf(dt) = SymTab.ClReal) THEN
- 3963                                               (* REAL/LONGREAL: the
- 3964                                                  implementation bounds *)
- 3965                                               IF isMax THEN
- 3966                                                 QbeGen.NormReal(
- 3967                                                   "3.402823e38", q)
- 3968                                               ELSE QbeGen.NormReal(
- 3969                                                   "-3.402823e38", q)
- 3970                                               END;
- 3971                                               t := SymTab.RealType()
- 3972                                             ELSIF (dt #
- 3973                                                SymTab.InvalidType)
- 3974   AND (SymTab.ClassOf(dt) =
- 3975                                                   SymTab.ClLong) THEN
- 3976                                               IF isMax THEN
- 3977                                                 QbeGen.CopyOp(
- 3978                                                   "9223372036854775807", q)
- 3979                                               ELSE QbeGen.CopyOp(
- 3980                                                   "-9223372036854775808", q)
- 3981                                               END;
- 3982                                               t := SymTab.LongType()
- 3983                                             ELSIF SymTab.TypeBounds(dt, lo,
- 3984                                                      hi) THEN
- 3985                                               IF isMax THEN
- 3986                                                 QbeGen.IntStr(hi, q)
- 3987                                               ELSE QbeGen.IntStr(lo, q)
- 3988                                               END;
- 3989                                               (* a set's bounds are those
- 3990                                                  of its base type *)
- 3991                                               IF SymTab.ClassOf(dt) =
- 3992                                                  SymTab.ClSet THEN
- 3993                                                 t := SymTab.SetBase(dt)
- 3994                                               ELSE t := SymTab.IntType()
- 3995                                               END
- 3996                                             ELSE SemError(230);
- 3997                                               t := SymTab.InvalidType;
- 3998                                               QbeGen.CopyOp("0", q)
- 3999                                             END; .)
- 4000      | "ADR" "(" Design<dt, dk, qd, qn, sfx> ")"
- 4001      (. astNode := AST.MakeNode(AST.NkCall);
- 4002     AST.SetChild(astNode, 0, AST.MakeLeaf(AST.NkIdent, "ADR"));
- 4003     IF astCur # AST.NoNode THEN AST.SetChild(astNode, 1, astCur) END;
- 4004     astCur := astNode; astIsLit := TRUE; .)
- 4005                                          (. IF dt = SymTab.InvalidType THEN
- 4006                                               t := SymTab.InvalidType;
- 4007                                               QbeGen.CopyOp("0", q)
- 4008                                             ELSE
- 4009                                                IF sfx
- 4010                                                   OR (dk = SymTab.KindVar)
- 4011                                                   OR (dk = SymTab.KindParam) THEN
- 4012                                                  QbeGen.CopyOp("@", q)
- 4013                                                ELSE SemError(230);
- 4014                                                  QbeGen.CopyOp("0", q)
- 4015                                                END;
- 4016                                               t := SymTab.AddrType()
- 4017                                             END; .)
- 4018      | "CHR" "(" Expr<et, q> ")"
- 4019      (. astNode := AST.MakeNode(AST.NkCall);
- 4020     AST.SetChild(astNode, 0, AST.MakeLeaf(AST.NkIdent, "CHR"));
- 4021     IF astCur # AST.NoNode THEN AST.SetChild(astNode, 1, astCur) END;
- 4022     astCur := astNode; astIsLit := TRUE; .)
- 4023                                          (. IF (et # SymTab.InvalidType)
- 4024   AND NOT SymTab.IsIntFamily(et) THEN
- 4025                                               SemError(211) END;
- 4026                                             t := SymTab.CharType(); .)
- 4027      | "ORD" "(" Expr<et, q> ")"
- 4028      (. astNode := AST.MakeNode(AST.NkCall);
- 4029     AST.SetChild(astNode, 0, AST.MakeLeaf(AST.NkIdent, "ORD"));
- 4030     IF astCur # AST.NoNode THEN AST.SetChild(astNode, 1, astCur) END;
- 4031     astCur := astNode; astIsLit := TRUE; .)
- 4032                                          (. IF et # SymTab.InvalidType THEN
- 4033                                               IF (SymTab.ClassOf(et) #
- 4034                                                   SymTab.ClChar)
- 4035   AND (SymTab.ClassOf(et) #
- 4036                                                     SymTab.ClBool)
- 4037   AND (SymTab.ClassOf(et) #
- 4038                                                     SymTab.ClEnum)
- 4039   AND NOT SymTab.IsIntFamily(et)
- 4040   AND NOT SymTab.IsPackedSet(et) THEN
- 4041                                                 SemError(211) END
- 4042                                             END;
- 4043                                             t := SymTab.IntType(); .)
- 4044      | "CAP" "(" Expr<et, q> ")"
- 4045      (. astNode := AST.MakeNode(AST.NkCall);
- 4046     AST.SetChild(astNode, 0, AST.MakeLeaf(AST.NkIdent, "CAP"));
- 4047     IF astCur # AST.NoNode THEN AST.SetChild(astNode, 1, astCur) END;
- 4048     astCur := astNode; astIsLit := TRUE; .)
- 4049                                           (. IF QbeGen.IsImm(q)
- 4050    AND SymTab.ConstInt(q, lo) THEN
- 4051       IF (lo >= VAL(INTEGER, ORD("a"))) AND (lo <= VAL(INTEGER, ORD("z"))) THEN lo := lo - 32 END;
- 4052       QbeGen.IntStr(lo, q)
- 4053     ELSE QbeGen.CopyOp("@", q)
- 4054     END;
- 4055     t := SymTab.CharType(); .)
- 4056      | "UCHR" "(" Expr<et, q> ")"
- 4057      (. astNode := AST.MakeNode(AST.NkCall);
- 4058     AST.SetChild(astNode, 0, AST.MakeLeaf(AST.NkIdent, "UCHR"));
- 4059     IF astCur # AST.NoNode THEN AST.SetChild(astNode, 1, astCur) END;
- 4060     astCur := astNode; astIsLit := TRUE; .)
- 4061                                          (. (* UCHR: the UCHAR constructor.
- 4062                                                CHAR -> UCHAR (identity);
- 4063                                                INTEGER familly -> UCHAR
- 4064                                                (codepoint value). *)
- 4065                                             IF (et # SymTab.InvalidType)
- 4066    AND (SymTab.ClassOf(et) # SymTab.ClChar)
- 4067    AND NOT SymTab.IsIntFamily(et) THEN
- 4068                                               SemError(211) END;
- 4069                                             t := SymTab.UCharType(); .)
- 4070      | "CHR8" "(" Expr<et, q> ")"
- 4071      (. astNode := AST.MakeNode(AST.NkCall);
- 4072     AST.SetChild(astNode, 0, AST.MakeLeaf(AST.NkIdent, "CHR8"));
- 4073     IF astCur # AST.NoNode THEN AST.SetChild(astNode, 1, astCur) END;
- 4074     astCur := astNode; astIsLit := TRUE; .)
- 4075                                          (. IF (et # SymTab.InvalidType)
- 4076    AND (SymTab.ClassOf(et) # SymTab.ClUChar) THEN
- 4077                                               SemError(211) END;
- 4078                                             t := SymTab.CharType(); .)
- 4079      | "UORD" "(" Expr<et, q> ")"
- 4080      (. astNode := AST.MakeNode(AST.NkCall);
- 4081     AST.SetChild(astNode, 0, AST.MakeLeaf(AST.NkIdent, "UORD"));
- 4082     IF astCur # AST.NoNode THEN AST.SetChild(astNode, 1, astCur) END;
- 4083     astCur := astNode; astIsLit := TRUE; .)
- 4084                                          (. (* UORD(u): the codepoint as a
- 4085                                                32-bit ordinal (INTEGER),
- 4086                                                cf. ORD for CHAR. *)
- 4087                                             IF (et # SymTab.InvalidType)
- 4088    AND (SymTab.ClassOf(et) # SymTab.ClUChar) THEN
- 4089                                               SemError(211) END;
- 4090                                             t := SymTab.IntType(); .)
- 4091      | "ABS" "(" Expr<et, q> ")"
- 4092      (. astNode := AST.MakeNode(AST.NkCall);
- 4093     AST.SetChild(astNode, 0, AST.MakeLeaf(AST.NkIdent, "ABS"));
- 4094     IF astCur # AST.NoNode THEN AST.SetChild(astNode, 1, astCur) END;
- 4095     astCur := astNode; astIsLit := TRUE; .)
- 4096                                          (. IF (et # SymTab.InvalidType)
- 4097   AND NOT SymTab.IsIntFamily(et)
- 4098   AND (SymTab.ClassOf(et) #
- 4099                                                  SymTab.ClReal) THEN
- 4100                                               SemError(211)
- 4101                                              ELSIF QbeGen.IsImm(q)
- 4102    AND SymTab.ConstInt(q, lo) THEN
- 4103                                                IF lo < 0 THEN lo := -lo END;
- 4104                                                QbeGen.IntStr(lo, q)
- 4105                                              ELSE QbeGen.CopyOp("@", q)
- 4106                                             END;
- 4107                                             t := et; .)
- 4108      | "ODD" "(" Expr<et, q> ")"
- 4109      (. astNode := AST.MakeNode(AST.NkCall);
- 4110     AST.SetChild(astNode, 0, AST.MakeLeaf(AST.NkIdent, "ODD"));
- 4111     IF astCur # AST.NoNode THEN AST.SetChild(astNode, 1, astCur) END;
- 4112     astCur := astNode; astIsLit := TRUE; .)
- 4113                                          (. IF (et # SymTab.InvalidType)
- 4114   AND NOT SymTab.IsIntFamily(et) THEN
- 4115                                               SemError(211) END;
- 4116                                             t := SymTab.BoolType();
- 4117                                             IF QbeGen.IsImm(q)
- 4118    AND SymTab.ConstInt(q, lo) THEN
- 4119                                               IF (lo MOD 2) # 0 THEN
- 4120                                                 QbeGen.CopyOp("1", q)
- 4121                                               ELSE QbeGen.CopyOp("0", q)
- 4122                                               END
- 4123                                             ELSE QbeGen.CopyOp("@", q)
- 4124                                             END; .)
- 4125      | "TRUNC" "(" Expr<et, q> ")"
- 4126      (. (* TRUNC(x): real -> INTEGER, as the VAL builtin *)
- 4127     astNode := AST.MakeNode(AST.NkCall);
- 4128     AST.SetChild(astNode, 0, AST.MakeLeaf(AST.NkIdent, "VAL"));
- 4129     AST.SetChild(astNode, 1, AST.MakeLeaf(AST.NkIdent, "INTEGER"));
- 4130     IF astCur # AST.NoNode THEN AST.SetChild(astNode, 2, astCur) END;
- 4131     astCur := astNode; astIsLit := TRUE; .)
- 4132                                          (. t := SymTab.IntType();
- 4133                                             QbeGen.CopyOp("@", q); .)
- 4134      | "FLOAT" "(" Expr<et, q> ")"
- 4135      (. (* FLOAT(i): integer -> REAL, as the VAL builtin *)
- 4136     astNode := AST.MakeNode(AST.NkCall);
- 4137     AST.SetChild(astNode, 0, AST.MakeLeaf(AST.NkIdent, "VAL"));
- 4138     AST.SetChild(astNode, 1, AST.MakeLeaf(AST.NkIdent, "REAL"));
- 4139     IF astCur # AST.NoNode THEN AST.SetChild(astNode, 2, astCur) END;
- 4140     astCur := astNode; astIsLit := TRUE; .)
- 4141                                          (. t := SymTab.RealType();
- 4142     IF QbeGen.IsImm(q) AND SymTab.ConstInt(q, lo) THEN QbeGen.NormReal(q, qa); QbeGen.CopyOp(qa, q)
- 4143     ELSE QbeGen.CopyOp("@", q) END; .)
- 4144      | ( "VAL" | "CONVERT" | "CAST" ) "(" GetIdent<vn> (. astArg2 := AST.MakeLeaf(AST.NkIdent, vn); .) "," Expr<et, q> ")"
- 4145      (. astNode := AST.MakeNode(AST.NkCall);
- 4146     AST.SetChild(astNode, 0, AST.MakeLeaf(AST.NkIdent, "VAL"));
- 4147     IF astArg2 # AST.NoNode THEN AST.SetChild(astNode, 1, astArg2) END;
- 4148     IF astCur # AST.NoNode THEN AST.SetChild(astNode, 2, astCur) END;
- 4149     astCur := astNode; astIsLit := TRUE; .)
- 4150                                          (. IF NOT SymTab.Lookup(vn) THEN
- 4151                                               SemError(201);
- 4152                                               t := SymTab.InvalidType
- 4153                                             ELSE vt := SymTab.SymType(vn);
- 4154                                               IF vt = SymTab.InvalidType THEN
- 4155                                                 t := SymTab.InvalidType
- 4156                                               ELSIF et =
- 4157                                                  SymTab.InvalidType THEN
- 4158                                                 t := vt
- 4159                                               ELSE
- 4160                                                 c1 := SymTab.ClassOf(et);
- 4161                                                 c2 := SymTab.ClassOf(vt);
- 4162                                                 IF ((c1 = SymTab.ClInt)
- 4163      OR (c1 = SymTab.ClByte) OR (c1 = SymTab.ClSByte)
- 4164      OR (c1 = SymTab.ClWord16) OR (c1 = SymTab.ClSWord16))
- 4165    AND (c2 = SymTab.ClLong) THEN
- 4166                                                   IF NOT QbeGen.IsImm(q) THEN QbeGen.WidenLong(q, qa); QbeGen.CopyOp(qa, q) END;
- 4167                                                   t := vt
- 4168                                                 ELSIF (c1 = SymTab.ClLong)
- 4169    AND ((c2 = SymTab.ClInt) OR (c2 = SymTab.ClByte)
- 4170      OR (c2 = SymTab.ClSByte) OR (c2 = SymTab.ClWord16)
- 4171      OR (c2 = SymTab.ClSWord16)) THEN
- 4172                                                   IF NOT (QbeGen.IsImm(q) AND SymTab.ConstInt(q, lo)) THEN QbeGen.NarrowLong(q, qa); QbeGen.CopyOp(qa, q) END;
- 4173                                                   t := vt
- 4174                                                 ELSIF ((c1 = SymTab.ClInt)
- 4175      OR (c1 = SymTab.ClByte) OR (c1 = SymTab.ClSByte)
- 4176      OR (c1 = SymTab.ClWord16) OR (c1 = SymTab.ClSWord16))
- 4177    AND (c2 = SymTab.ClReal) THEN
- 4178                                                   IF QbeGen.IsImm(q) AND SymTab.ConstInt(q, lo) THEN QbeGen.NormReal(q, qa) ELSE QbeGen.ConvIR(q, qa) END;
- 4179                                                   QbeGen.CopyOp(qa, q);
- 4180                                                   t := vt
- 4181                                                 ELSIF (c1 = SymTab.ClLong)
- 4182    AND (c2 = SymTab.ClReal) THEN
- 4183                                                   IF QbeGen.IsImm(q) AND SymTab.ConstInt(q, lo) THEN QbeGen.NormReal(q, qa) ELSE QbeGen.ConvLR(q, qa) END;
- 4184                                                   QbeGen.CopyOp(qa, q);
- 4185                                                   t := vt
- 4186                                                 ELSIF (c1 = SymTab.ClReal)
- 4187    AND ((c2 = SymTab.ClInt) OR (c2 = SymTab.ClByte)
- 4188      OR (c2 = SymTab.ClSByte) OR (c2 = SymTab.ClWord16)
- 4189      OR (c2 = SymTab.ClSWord16)) THEN
- 4190                                                   QbeGen.ConvRI(q, qa);
- 4191                                                   QbeGen.CopyOp(qa, q);
- 4192                                                   t := vt
- 4193                                                 ELSIF (c1 = SymTab.ClReal)
- 4194    AND (c2 = SymTab.ClLong) THEN
- 4195                                                   QbeGen.ConvRL(q, qa);
- 4196                                                   QbeGen.CopyOp(qa, q);
- 4197                                                   t := vt
- 4198                                                 ELSIF (c1 = SymTab.ClLong)
- 4199    AND (c2 = SymTab.ClLong) THEN
- 4200                                                   t := vt
- 4201                                                 ELSIF ((c1 = SymTab.ClInt)
- 4202                                                     OR (c1 =
- 4203                                                        SymTab.ClChar)
- 4204                                                     OR (c1 =
- 4205                                                        SymTab.ClBool)
- 4206                                                     OR (c1 =
- 4207                                                        SymTab.ClByte)
- 4208                                                     OR (c1 =
- 4209                                                        SymTab.ClSByte)
- 4210                                                     OR (c1 =
- 4211                                                        SymTab.ClWord16)
- 4212                                                     OR (c1 =
- 4213                                                        SymTab.ClSWord16)
- 4214                                                     OR (c1 =
- 4215                                                        SymTab.ClEnum))
- 4216   AND ((c2 = SymTab.ClInt)
- 4217                                                     OR (c2 =
- 4218                                                        SymTab.ClChar)
- 4219                                                     OR (c2 =
- 4220                                                        SymTab.ClBool)
- 4221                                                     OR (c2 =
- 4222                                                        SymTab.ClByte)
- 4223                                                     OR (c2 =
- 4224                                                        SymTab.ClSByte)
- 4225                                                     OR (c2 =
- 4226                                                        SymTab.ClWord16)
- 4227                                                     OR (c2 =
- 4228                                                        SymTab.ClSWord16)
- 4229                                                     OR (c2 =
- 4230                                                        SymTab.ClEnum)) THEN
- 4231                                                   t := vt
- 4232                                                 ELSIF (c1 = SymTab.ClPtr)
- 4233    AND (c2 = SymTab.ClPtr) THEN
- 4234                                                   t := vt
- 4235                                                 ELSIF ((c1 = SymTab.ClProc)
- 4236    AND (c2 = SymTab.ClProc))
- 4237    OR ((c1 = SymTab.ClProc) AND (c2 = SymTab.ClPtr))
- 4238    OR ((c1 = SymTab.ClPtr) AND (c2 = SymTab.ClProc)) THEN
- 4239                                                   t := vt
- 4240                                                 ELSIF (c1 = SymTab.ClReal)
- 4241   AND (c2 = SymTab.ClReal) THEN
- 4242                                                   t := vt
- 4243                                                 ELSIF ((c1 = SymTab.ClSet) AND (c2 = SymTab.ClInt))
- 4244    OR ((c1 = SymTab.ClInt) AND (c2 = SymTab.ClSet)) THEN
- 4245                                                   (* a set <-> its machine word (BITSET) *)
- 4246                                                   t := vt
- 4247                                                 ELSE SemError(230);
- 4248                                                   t := SymTab.InvalidType
- 4249                                                 END
- 4250                                               END
- 4251                                             END; .)
- 4252      | "(" Expr<et, q> ")"               (. t := et; astIsLit := TRUE; .)
- 4253      | SetLit<st, sq>                    (. astIsLit := TRUE; t := st;
- 4254                                             QbeGen.CopyOp(sq, q); .)
- 4255      | ( "NOT" | "~" ) Fact<t2, q2>      (. astNot := astCur;
- 4256                                             IF SymTab.BoolCheck(t2) THEN
- 4257                                               t := SymTab.BoolType()
- 4258                                             ELSE SemError(212);
- 4259                                               t := SymTab.InvalidType END;
- 4260                                             IF t # SymTab.InvalidType THEN
- 4261                                                QbeGen.CopyOp("@", q)
- 4262                                             ELSE QbeGen.CopyOp("0", q)
- 4263                                             END;
- 4264                                             astIsLit := TRUE;
- 4265                                             astCur := AST.MakeUn(
- 4266                                               AST.NkUnary, AST.OpNot, astNot); .)
- 4267      )
- 4268      (. IF NOT astIsLit THEN astCur := AST.NoNode END; .)
- 4269             (. IF astCur # AST.NoNode THEN AST.SetTy(astCur, t) END; .) .
- 4270    (* Set literals are SET OF [0..255] (8 words); elements validated
- 4271       0..255 statically when foldable (222 otherwise), runtime trap
- 4272       for computed elements. Ranges always lower via SetRange. *)
- 4273    SetLit<VAR t: SymTab.TypeIndex; VAR q: QbeGen.QVal>
- 4274                                          (. VAR astNode: AST.Node; .)
- 4275      = "{"                               (. t := SymTab.NewSet(
- 4276                                               SymTab.NewSubR(0, 255));
- 4277                                             astNode := AST.MakeNode(AST.NkSetLit);
- 4278                                             QbeGen.NewSetTemp(8, q);
- 4279                                             QbeGen.SetZero(q, 8); .)
- 4280        [ SetElem<t, q, astNode> { "," SetElem<t, q, astNode> } ]
- 4281        "}"                               (. astCur := astNode; .) .
- 4282    (* Typed brace constructor: TypeName{ elems } — BITSET{0} (a set)
- 4283       or ArrayName{...} (an array constructor, GNU Modula-2).  The
- 4284       declared type sets the width (set) or element type (array). *)
- 4285    TypedBraceLit<vt: SymTab.TypeIndex; VAR q: QbeGen.QVal>
- 4286                                          (. VAR nw: CARDINAL;
- 4287                                               astNode, astTail: AST.Node;
- 4288                                               savedCls: INTEGER; .)
- 4289      = "{"                               (. savedCls := braceCls;
- 4290                                             astNode := AST.MakeNode(AST.NkBraceLit);
- 4291                                             AST.SetTy(astNode, vt);
- 4292                                             astTail := astNode;
- 4293                                             IF vt = SymTab.InvalidType THEN
- 4294                                               braceCls := -1
- 4295                                             ELSE braceCls :=
- 4296                                                    SymTab.ClassOf(vt)
- 4297                                             END;
- 4298                                             IF braceCls = SymTab.ClSet THEN
- 4299                                               IF vt = SymTab.InvalidType THEN
- 4300                                                 nw := 8
- 4301                                               ELSE nw := SymTab.SetWords(vt);
- 4302                                                 IF nw = 0 THEN nw := 8 END
- 4303                                               END;
- 4304                                               QbeGen.NewSetTemp(nw, q);
- 4305                                               QbeGen.SetZero(q, nw)
- 4306                                             ELSIF (braceCls =
- 4307                                                    SymTab.ClArray)
- 4308                                                OR (braceCls =
- 4309                                                    SymTab.ClRecord)
- 4310                                                OR (braceCls =
- 4311                                                    SymTab.ClClass) THEN
- 4312                                               QbeGen.CtorBegin(vt)
- 4313                                             ELSE
- 4314                                               IF vt # SymTab.InvalidType THEN
- 4315                                                 SemError(230) END;
- 4316                                               braceCls := -1
- 4317                                             END; .)
- 4318        [ BraceElem<vt, q, astNode, astTail>
- 4319          { "," BraceElem<vt, q, astNode, astTail> } ]
- 4320        "}"                               (. IF (braceCls = SymTab.ClArray)
- 4321                                                OR (braceCls =
- 4322                                                   SymTab.ClRecord)
- 4323                                                OR (braceCls =
- 4324                                                   SymTab.ClClass) THEN
- 4325                                               QbeGen.CtorEnd(q)
- 4326                                             ELSIF braceCls # SymTab.ClSet THEN
- 4327                                               QbeGen.CopyOp("0", q)
- 4328                                             END;
- 4329                                             braceCls := savedCls; .)
- 4330                                          (. astCur := astNode; .) .
- 4331    BraceElem<vt: SymTab.TypeIndex; VAR sq: QbeGen.QVal;
- 4332              VAR node, tail: AST.Node>
- 4333                                          (. VAR et, et2: SymTab.TypeIndex;
- 4334                                               qe, q2: QbeGen.QVal;
- 4335                                               v, v2, reps, k: INTEGER;
- 4336                                               elem: SymTab.TypeIndex;
- 4337                                               lo: INTEGER;
- 4338                                               span: CARDINAL;
- 4339                                               cl, cl2: INTEGER;
- 4340                                               hasR, hasB: BOOLEAN;
- 4341                                               astEl: AST.Node; .)
- 4342      =                                   (. hasR := FALSE; hasB := FALSE;
- 4343                                             reps := 1; .)
- 4344        Expr<et, qe> (. astEl := astCur; .)
- 4345        [ ".." Expr<et2, q2>              (. astEl := AST.MakeBin(
- 4346                                               AST.NkSubrange, 0, astEl, astCur);
- 4347                                             hasR := TRUE; .) ]
- 4348        [ "BY" Expr<et2, q2>              (. hasB := TRUE; .) ]
- 4349                                          (. IF braceCls = SymTab.ClSet THEN
- 4350                                               IF hasB THEN SemError(230) END;
- 4351                                               lo := SymTab.SetBaseLo(vt);
- 4352                                               span := SymTab.SetCount(vt);
- 4353                                               IF (et = SymTab.InvalidType)
- 4354                                                  OR (hasR AND (et2 =
- 4355                                                     SymTab.InvalidType)) THEN
- 4356                                               ELSE cl :=
- 4357                                                      SymTab.ClassOf(et);
- 4358                                                 IF hasR THEN
- 4359                                                   cl2 :=
- 4360                                                     SymTab.ClassOf(et2)
- 4361                                                 ELSE cl2 := SymTab.ClInt
- 4362                                                 END;
- 4363                                                 IF NOT SymTab.SetElemClassOk(cl)
- 4364                                                    OR (hasR AND NOT
- 4365                                                       SymTab.SetElemClassOk(cl2))
- 4366                                                 THEN
- 4367                                                   SemError(222)
- 4368                                                 ELSIF hasR
- 4369   AND SymTab.ConstInt(qe, v)
- 4370   AND SymTab.ConstInt(q2,
- 4371                                                       v2)
- 4372   AND ((v < lo)
- 4373                                                       OR (v2 < lo)
- 4374                                                       OR (v >= lo +
- 4375                                                          VAL(INTEGER, span))
- 4376                                                       OR (v2 >= lo +
- 4377                                                          VAL(INTEGER, span))
- 4378                                                       OR (v > v2)) THEN
- 4379                                                   SemError(222)
- 4380                                                  ELSIF hasR THEN
- 4381                                                    QbeGen.SetRange(sq, qe, q2,
- 4382                                                      lo, span)
- 4383                                                  ELSIF SymTab.ConstInt(qe,
- 4384                                                          v)
- 4385   AND ((v < lo)
- 4386                                                        OR (v >= lo +
- 4387                                                           VAL(INTEGER,
- 4388                                                             span))) THEN
- 4389                                                    SemError(222)
- 4390                                                  ELSE QbeGen.SetBit(sq, qe,
- 4391                                                    lo, span)
- 4392                                                 END
- 4393                                               END
- 4394                                             ELSIF (braceCls = SymTab.ClArray)
- 4395                                                OR (braceCls =
- 4396                                                   SymTab.ClRecord)
- 4397                                                OR (braceCls =
- 4398                                                   SymTab.ClClass) THEN
- 4399                                               IF hasR THEN SemError(230) END;
- 4400                                               reps := 1;
- 4401                                               IF hasB THEN
- 4402                                                 IF SymTab.ConstInt(q2, v2)
- 4403   AND (v2 >= 1) THEN
- 4404                                                   reps := v2
- 4405                                                 ELSE SemError(230)
- 4406                                                 END
- 4407                                               END;
- 4408                                               k := 0;
- 4409                                               WHILE k < reps DO
- 4410                                                 QbeGen.CtorElem(qe);
- 4411                                                 INC(k)
- 4412                                               END
- 4413                                             END; .)
- 4414                                          (. (* the BY form repeats the
- 4415                                               element; keep the AST in
- 4416                                               step with CtorElem *)
- 4417                                             k := 0;
- 4418                                             WHILE k < reps DO
- 4419                                               AstAppend(AST.NkBlock,
- 4420                                                 node, tail, astEl);
- 4421                                               INC(k)
- 4422                                             END; .) .
- 4423    SetElem<st: SymTab.TypeIndex; sq: QbeGen.QVal; node: AST.Node>         (. VAR et, et2: SymTab.TypeIndex;
- 4424                                               qe, q2: QbeGen.QVal;
- 4425                                               v, v2: INTEGER;
- 4426                                               lo: INTEGER;
- 4427                                               span: CARDINAL;
- 4428                                               cl, cl2: INTEGER;
- 4429                                               hasR: BOOLEAN;
- 4430                                               astEl: AST.Node; .)
- 4431      =                                   (. hasR := FALSE; .)
- 4432        Expr<et, qe> (. astEl := astCur; .)
- 4433        [ ".." Expr<et2, q2>              (. astEl := AST.MakeBin(
- 4434                                               AST.NkSubrange, 0, astEl, astCur);
- 4435                                             hasR := TRUE; .) ]
- 4436                                          (. lo := SymTab.SetBaseLo(st);
- 4437                                             span := SymTab.SetCount(st);
- 4438                                             IF (et = SymTab.InvalidType)
- 4439                                                OR (hasR AND (et2 =
- 4440                                                   SymTab.InvalidType)) THEN
- 4441                                             ELSE cl :=
- 4442                                                    SymTab.ClassOf(et);
- 4443                                               IF hasR THEN
- 4444                                                 cl2 :=
- 4445                                                   SymTab.ClassOf(et2)
- 4446                                               ELSE cl2 := SymTab.ClInt
- 4447                                               END;
- 4448                                               IF NOT SymTab.SetElemClassOk(cl)
- 4449                                                  OR (hasR AND NOT
- 4450                                                     SymTab.SetElemClassOk(cl2))
- 4451                                               THEN
- 4452                                                 SemError(222)
- 4453                                               ELSIF hasR
- 4454   AND SymTab.ConstInt(qe, v)
- 4455   AND SymTab.ConstInt(q2,
- 4456                                                     v2)
- 4457   AND ((v < lo)
- 4458                                                     OR (v2 < lo)
- 4459                                                     OR (v >= lo +
- 4460                                                        VAL(INTEGER, span))
- 4461                                                     OR (v2 >= lo +
- 4462                                                        VAL(INTEGER, span))
- 4463                                                     OR (v > v2)) THEN
- 4464                                                 SemError(222)
- 4465                                                ELSIF hasR THEN
- 4466                                                  QbeGen.SetRange(sq, qe, q2,
- 4467                                                    lo, span)
- 4468                                                ELSIF SymTab.ConstInt(qe,
- 4469                                                        v)
- 4470   AND ((v < lo)
- 4471                                                      OR (v >= lo +
- 4472                                                         VAL(INTEGER,
- 4473                                                           span))) THEN
- 4474                                                  SemError(222)
- 4475                                                ELSE QbeGen.SetBit(sq, qe,
- 4476                                                  lo, span)
- 4477                                               END
- 4478                                             END; .)
- 4479                                          (. AST.SetChild(node,
- 4480                                               AST.NChild(node), astEl); .) .
- 4481    GetIdent<VAR n: SymTab.Name>
- 4482      = ident                             (. LexName(n); .) .
- 4483  
- 4484  END M2.
+ 1798                                             ct := SymTab.NewClass();
+ 1799                                             SymTab.SetSymType(cn, ct);
+ 1800                                             SymTab.PushClassScope(ct);
+ 1801                                             astCls := AST.MakeNode(AST.NkClassDecl);
+ 1802                                             AST.SetChild(astCls, 0,
+ 1803                                               AST.MakeLeaf(AST.NkIdent, cn));
+ 1804                                             astClsP := AST.NoNode;
+ 1805                                             astClsPTail := AST.NoNode;
+ 1806                                             astClsF := AST.NoNode;
+ 1807                                             astClsFTail := AST.NoNode;
+ 1808                                             astClsM := AST.NoNode;
+ 1809                                             astClsMTail := AST.NoNode; .)
+ 1810        [ Parents<ct> ]
+ 1811        ";"
+ 1812        { ClassField<ct> ";" }
+ 1813        { MethodHeading<pn, SymTab.InvalidType> ";"
+ 1814                                          (. Lower.ScopeLeave;
+ 1815                                             SymTab.CloseProc;
+ 1816                                             QbeGen.AbortFunc; .) }
+ 1817        "END"
+ 1818        GetIdent<m2>                      (. IF NOT SymTab.Equal(cn, m2) THEN
+ 1819                                               SemError(202) END;
+ 1820                                             SymTab.LayoutClass(ct);
+ 1821                                             SymTab.PopScope;
+ 1822                                             AST.SetChild(astCls, 1, astClsP);
+ 1823                                             AST.SetChild(astCls, 2, astClsF);
+ 1824                                             AST.SetChild(astCls, 3, astClsM);
+ 1825                                             astDecl := astCls; .) .
+ 1826    Parents<ct: SymTab.TypeIndex>         (. VAR p: SymTab.Name; .)
+ 1827      = "(" Parent1<ct>
+ 1828        { "," GetIdent<p>                 (. SemError(230); .) }
+ 1829        ")" .
+ 1830    Parent1<ct: SymTab.TypeIndex>         (. VAR p: SymTab.Name;
+ 1831                                               pt: SymTab.TypeIndex; .)
+ 1832      = GetIdent<p>                       (. IF NOT SymTab.Lookup(p) THEN
+ 1833                                               SemError(201)
+ 1834                                             ELSE pt := SymTab.SymType(p);
+ 1835                                               IF SymTab.ClassOf(pt) #
+ 1836                                                  SymTab.ClClass THEN
+ 1837                                                 SemError(230)
+ 1838                                               ELSE SymTab.SetParent(ct, pt)
+ 1839                                               END
+ 1840                                             END;
+ 1841                                             AstAppend(AST.NkFieldDecl,
+ 1842                                               astClsP, astClsPTail,
+ 1843                                               AST.MakeLeaf(AST.NkIdent, p)); .) .
+ 1844    ClassField<ct: SymTab.TypeIndex>      (. VAR n, rhs: SymTab.Name;
+ 1845                                               t: SymTab.TypeIndex;
+ 1846                                               astNode: AST.Node; .)
+ 1847      = GetIdent<n>
+ 1848        ( "=" GetIdent<rhs>               (. IF NOT SymTab.Enter(n,
+ 1849                                               SymTab.KindConst) THEN
+ 1850                                               SemError(200) END;
+ 1851                                             astNode := AST.MakeNode(AST.NkConstDecl);
+ 1852                                             AST.SetChild(astNode, 0,
+ 1853                                               AST.MakeLeaf(AST.NkIdent, n));
+ 1854                                             AST.SetChild(astNode, 1,
+ 1855                                               AST.MakeLeaf(AST.NkIdent, rhs));
+ 1856                                             AstAppend(AST.NkFieldDecl,
+ 1857                                               astClsF, astClsFTail, astNode);
+ 1858                                             IF SymTab.Lookup(rhs) THEN
+ 1859                                               SymTab.SetSymType(n,
+ 1860                                                 SymTab.SymType(rhs))
+ 1861                                             END; .)
+ 1862        |                                 (. IF NOT SymTab.FieldPending(ct,
+ 1863                                               n) THEN
+ 1864                                               SemError(200) END;
+ 1865                                             astNode := AST.MakeNode(AST.NkVarDecl);
+ 1866                                             AST.SetChild(astNode, 0,
+ 1867                                               AST.MakeLeaf(AST.NkIdent, n)); .)
+ 1868          { "," GetIdent<n>               (. IF NOT SymTab.FieldPending(ct,
+ 1869                                               n) THEN
+ 1870                                               SemError(200) END;
+ 1871                                             AST.SetChild(astNode,
+ 1872                                               AST.NChild(astNode),
+ 1873                                               AST.MakeLeaf(AST.NkIdent, n)); .) }
+ 1874          ":" Type<t, FALSE>              (. SymTab.FixPendingF(ct, t);
+ 1875                                             AST.SetTy(astNode, t);
+ 1876                                             AstAppend(AST.NkFieldDecl,
+ 1877                                               astClsF, astClsFTail, astNode); .) ) .
+ 1878    MethodHeading<VAR pn: SymTab.Name; ct: SymTab.TypeIndex>
+ 1879                                          (. VAR wantVirt: BOOLEAN; .)
+ 1880      =                                   (. wantVirt := FALSE; .)
+ 1881        [ "VIRTUAL"                       (. wantVirt := TRUE; .) ]
+ 1882        ProcHeading<pn, ct>               (. IF wantVirt THEN
+ 1883                                               SymTab.MarkVirtual END;
+ 1884                                             astMethod := AST.MakeNode(AST.NkProcDecl);
+ 1885                                             AST.SetChild(astMethod, 0,
+ 1886                                               AST.MakeLeaf(AST.NkIdent, pn));
+ 1887                                             IF wantVirt THEN
+ 1888                                               AST.SetOp(astMethod, 3)
+ 1889                                             ELSE AST.SetOp(astMethod, 0)
+ 1890                                             END;
+ 1891                                             AstAppend(AST.NkFieldDecl,
+ 1892                                               astClsM, astClsMTail, astMethod); .) .
+ 1893    ClassImplRest                         (. VAR cn, m2: SymTab.Name;
+ 1894                                               ct: SymTab.TypeIndex;
+ 1895                                               astBody, astHandler: AST.Node;
+ 1896                                               hasExcept: BOOLEAN; .)
+ 1897      = GetIdent<cn>                      (. IF NOT SymTab.Lookup(cn) THEN
+ 1898                                               SemError(201);
+ 1899                                               ct := SymTab.InvalidType
+ 1900                                             ELSE ct := SymTab.SymType(cn);
+ 1901                                               IF SymTab.ClassOf(ct) #
+ 1902                                                  SymTab.ClClass THEN
+ 1903                                                 SemError(230);
+ 1904                                                 ct := SymTab.InvalidType
+ 1905                                               END
+ 1906                                             END;
+ 1907                                             astCls := AST.MakeNode(AST.NkClassDecl);
+ 1908                                             AST.SetOp(astCls, 1);
+ 1909                                             AST.SetChild(astCls, 0,
+ 1910                                               AST.MakeLeaf(AST.NkIdent, cn));
+ 1911                                             astClsM := AST.NoNode;
+ 1912                                             astClsMTail := AST.NoNode;
+ 1913                                             astStmt := AST.NoNode;
+ 1914                                             inHandler := FALSE;
+ 1915                                             astHandler := AST.NoNode;
+ 1916                                             hasExcept := FALSE;
+ 1917                                             IF ct #
+ 1918                                                SymTab.InvalidType THEN
+ 1919                                               IF NOT SymTab.PushClassMembers(
+ 1920                                                      ct) THEN
+ 1921                                                 SemError(230) END;
+ 1922                                               SymTab.PushImplClass(ct)
+ 1923                                             END; .)
+ 1924        ";" { MethodImpl<ct> ";" }
+ 1925                                          (. astStmt := AST.NoNode; .)
+ 1926        [ "BEGIN"                         (. astStmt := AST.MakeNode(AST.NkBlock);
+ 1927                                             .)
+ 1928          [ StatSeq ] ]
+ 1929                                          (. astBody := astStmt; .)
+ 1930        [ "EXCEPT"                        (. (* M1: grammar/AST only; M2 removes
+ 1931                                                this 230 and adds codegen. *)
+ 1932                                             SemError(230);
+ 1933                                             hasExcept := TRUE;
+ 1934                                             inHandler := TRUE; .)
+ 1935          [ StatSeq ]                     (. astHandler := astStmt;
+ 1936                                             inHandler := FALSE .) ]
+ 1937        "END"
+ 1938        GetIdent<m2>                      (. IF NOT SymTab.Equal(cn, m2) THEN
+ 1939                                               SemError(202) END;
+ 1940                                             SymTab.PopImplClass;
+ 1941                                             SymTab.PopScope;
+ 1942                                             IF hasExcept THEN
+ 1943                                               astStmt := WrapExcept(astBody,
+ 1944                                                             astHandler)
+ 1945                                             END;
+ 1946                                             AST.SetChild(astCls, 1, AST.NoNode);
+ 1947                                             AST.SetChild(astCls, 2, astStmt);
+ 1948                                             AST.SetChild(astCls, 3, astClsM);
+ 1949                                             astDecl := astCls; .) .
+ 1950    MethodImpl<ct: SymTab.TypeIndex>      (. VAR pn: SymTab.Name;
+ 1951                                               thisQ: QbeGen.QVal;
+ 1952                                               methRes: SymTab.TypeIndex; .)
+ 1953      = MethodHeading<pn, ct> ";"
+ 1954                                          (. IF (ct #
+ 1955                                                SymTab.InvalidType)
+ 1956   AND NOT SymTab.MethodExists(ct,
+ 1957                                                    pn) THEN
+ 1958                                               SemError(201) END; .)
+ 1959        ( "FORWARD"                       (. AST.SetOp(astMethod, 1);
+ 1960                                             SymTab.MarkFwd;
+ 1961                                             QbeGen.AbortFunc;
+ 1962                                             Lower.ScopeLeave;
+ 1963                                             SymTab.CloseProc; .)
+ 1964        |                                 (.
+ 1965                                             (* bind the receiver: bare
+ 1966                                                field names resolve
+ 1967                                                against THIS *)
+ 1968                                              QbeGen.CopyOp("@", thisQ);
+ 1969                                             QbeGen.PushWith(thisQ); .)
+ 1970          Block<pn>                       (. AST.SetChild(astMethod, 1, astStmt);
+ 1971                                             AST.SetChild(astMethod, 2, astBlkDecls);
+ 1972                                             QbeGen.PopWith;
+ 1973                                             methRes := SymTab.CurRes();
+ 1974                                             Lower.ScopeLeave;
+ 1975                                             SymTab.CloseProc;
+ 1976                                             QbeGen.EndFunc(methRes); .) ) .
+ 1977    ConstBlock                            (. VAR astSeq, astTail: AST.Node; .)
+ 1978      = "CONST"                           (. astSeq := AST.NoNode;
+ 1979                                             astTail := AST.NoNode; .)
+ 1980        { ConstDecl ";"                   (. AstAppend(AST.NkDeclSeq,
+ 1981                                               astSeq, astTail, astDecl); .) }
+ 1982                                          (. astDecl := astSeq; .) .
+ 1983    ConstDecl                             (. VAR n: SymTab.Name;
+ 1984                                               t: SymTab.TypeIndex;
+ 1985                                               qv: QbeGen.QVal;
+ 1986                                               cls: INTEGER;
+ 1987                                               mk: ARRAY [0 .. 15] OF CARDINAL;
+ 1988                                               mw: CARDINAL;
+ 1989                                               mlo: INTEGER;
+ 1990                                               astNode: AST.Node; .)
+ 1991      = GetIdent<n>                       (. IF NOT SymTab.Enter(n,
+ 1992                                               SymTab.KindConst) THEN
+ 1993                                               SemError(200) END; .)
+ 1994        "="
+ 1995        Expr<t, qv> (. astNode := AST.MakeNode(AST.NkConstDecl);
+ 1996                                             AST.SetChild(astNode, 0,
+ 1997                                               AST.MakeLeaf(AST.NkIdent, n));
+ 1998                                             AST.SetChild(astNode, 1, astCur);
+ 1999                                             AST.SetTy(astNode, t);
+ 2000                                             astDecl := astNode;
+ 2001                                             Lower.NoteVar(n, SymTab.KindConst, t);
+ 2002                                             Lower.NoteConstVal(qv);
+ 2003                                             SymTab.SetSymType(n, t);
+ 2004                                             cls := SymTab.ClassOf(t);
+ 2005                                             IF cls = SymTab.ClSet THEN
+ 2006                                               (* a SET CONST needs static
+ 2007                                                  data: fold its mask now
+ 2008                                                  (the grammar sees the
+ 2009                                                  element values) and let
+ 2010                                                  Lower re-emit it *)
+ 2011                                               IF Lower.SetConstMaskOf(
+ 2012                                                    AST.Child(astNode, 1),
+ 2013                                                    mk, mw, mlo) THEN
+ 2014                                                 Lower.NoteSetMask(n, mk, mw,
+ 2015                                                   mlo);
+ 2016                                                 SymTab.SetSymVal(n, qv)
+ 2017                                               ELSE
+ 2018                                                 SemError(230)
+ 2019                                               END
+ 2020                                             ELSIF (cls = SymTab.ClArray)
+ 2021                                                OR (cls = SymTab.ClRecord)
+ 2022                                                OR (cls = SymTab.ClClass)
+ 2023                                                OR (cls = SymTab.ClStr)
+ 2024                                                OR (cls = SymTab.ClUStr) THEN
+ 2025                                               (* an aggregate/string
+ 2026                                                  constant: qv is its
+ 2027                                                  descriptor address; no
+ 2028                                                  scalar data *)
+ 2029                                               SymTab.SetSymVal(n, qv)
+ 2030                                             ELSIF NOT QbeGen.IsImm(qv) THEN
+ 2031                                               SemError(230)
+ 2032                                             ELSE
+ 2033                                               SymTab.SetSymVal(n, qv);
+ 2034                                             END; .) .
+ 2035    VarBlock                              (. VAR astSeq, astTail: AST.Node; .)
+ 2036      = "VAR"                             (. astSeq := AST.NoNode;
+ 2037                                             astTail := AST.NoNode; .)
+ 2038        { VarDecl ";"                     (. AstAppend(AST.NkDeclSeq,
+ 2039                                               astSeq, astTail, astDecl); .) }
+ 2040                                          (. astDecl := astSeq; .) .
+ 2041    VarDecl                               (. VAR nm: SymTab.Name;
+ 2042                                               t: SymTab.TypeIndex;
+ 2043                                               i: CARDINAL;
+ 2044                                               cls: INTEGER;
+ 2045                                               astNode, astTail: AST.Node; .)
+ 2046      = VarIdents ":"
+ 2047        Type<t, FALSE> (. astNode := AST.MakeNode(AST.NkVarDecl);
+ 2048                                             astTail := astNode;
+ 2049                                             i := 0;
+ 2050                                             WHILE i < SymTab.PendCount() DO
+ 2051                                               SymTab.PendName(i, nm);
+ 2052                                               Lower.NoteVar(nm, SymTab.KindVar, t);
+ 2053                                               (* chunked: a VAR list can
+ 2054                                                  exceed AST.MaxChild *)
+ 2055                                               AstAppend(AST.NkBlock,
+ 2056                                                 astNode, astTail,
+ 2057                                                 AST.MakeLeaf(AST.NkIdent, nm));
+ 2058                                               INC(i)
+ 2059                                             END;
+ 2060                                             AST.SetTy(astNode, t);
+ 2061                                             astDecl := astNode;
+ 2062                                             cls := SymTab.ClassOf(t);
+ 2063                                             IF (t # SymTab.InvalidType)
+ 2064   AND NOT SymTab.IsUnresolved(t)
+ 2065   AND (cls # SymTab.ClInt)
+ 2066   AND (cls # SymTab.ClBool)
+ 2067   AND (cls # SymTab.ClChar)
+ 2068   AND (cls # SymTab.ClReal)
+ 2069   AND (cls # SymTab.ClArray)
+ 2070   AND (cls # SymTab.ClSet)
+ 2071   AND (cls # SymTab.ClRecord)
+ 2072   AND (cls # SymTab.ClPtr)
+ 2073   AND (cls # SymTab.ClLong)
+ 2074   AND (cls # SymTab.ClProc)
+ 2075   AND (cls # SymTab.ClUChar)
+ 2076   AND (cls # SymTab.ClUStr)
+ 2077   AND (cls # SymTab.ClEnum)
+ 2078   AND (cls # SymTab.ClByte)
+ 2079   AND (cls # SymTab.ClSByte)
+ 2080   AND (cls # SymTab.ClWord16)
+ 2081   AND (cls # SymTab.ClSWord16)
+ 2082   AND (cls # SymTab.ClClass) THEN
+ 2083                                               SemError(230) END;
+ 2084                                             IF QbeGen.LocFull() THEN
+ 2085                                               SemError(233) END;
+ 2086                                             i := 0;
+ 2087                                             IF SymTab.IsUnresolved(t)
+ 2088                                                AND NOT SymTab.InProc() THEN
+ 2089                                               (* a forward-typed global:
+ 2090                                                  defer emission until the
+ 2091                                                  TYPE block completes *)
+ 2092                                               AST.SetOp(astNode, 1);
+ 2093                                               WHILE i < SymTab.PendCount() DO
+ 2094                                                 SymTab.PendName(i, nm);
+ 2095                                                 IF nPendVar <=
+ 2096                                                    HIGH(pendVarName) THEN
+ 2097                                                   pendVarName[nPendVar] := nm;
+ 2098                                                   pendVarT[nPendVar] := t;
+ 2099                                                   INC(nPendVar)
+ 2100                                                 END;
+ 2101                                                 INC(i)
+ 2102                                               END
+ 2103                                             ELSE
+ 2104                                               WHILE i < SymTab.PendCount() DO
+ 2105                                                 SymTab.PendName(i, nm);
+ 2106                                                 INC(i)
+ 2107                                               END
+ 2108                                             END;
+ 2109                                             (* a plain VAR list, not a
+ 2110                                                heading: the signature
+ 2111                                                result is discarded *)
+ 2112                                             IF NOT SymTab.FixPending(t) THEN
+ 2113                                             END; .) .
+ 2114    VarIdents                             (. VAR n: SymTab.Name; .)
+ 2115      = GetIdent<n>                       (. IF NOT SymTab.EnterPending(n,
+ 2116                                               SymTab.KindVar) THEN
+ 2117                                               SemError(200) END; .)
+ 2118        { ","
+ 2119          GetIdent<n>                     (. IF NOT SymTab.EnterPending(n,
+ 2120                                               SymTab.KindVar) THEN
+ 2121                                               SemError(200) END; .) } .
+ 2122    ParIdents<isV: BOOLEAN>               (. VAR n: SymTab.Name; .)
+ 2123      = GetIdent<n>                       (. IF NOT SymTab.EnterParam(n, isV) THEN
+ 2124                                               SemError(200) END; .)
+ 2125        { "," GetIdent<n>                 (. IF NOT SymTab.EnterParam(n, isV) THEN
+ 2126                                               SemError(200) END; .) } .
+ 2127    (* Procedure headings enter scopes/params/result and buffer the
+ 2128       QBE header; bodies lower to functions (4.1, module level only).
+ 2129       FORWARD marks; the body heading re-enters (signature compare
+ 2130       deferred). Nested procedures parse + check, lowering = 4.2. *)
+ 2131    (* gm2 declaration pragmas: __BUILTIN__ (definition module) and
+ 2132       __ATTRIBUTE__ __BUILTIN__ (( name )) (implementation).  They
+ 2133       annotate C built-ins; V3 parses and ignores them. *)
+ 2134    ProcPragma
+ 2135      = "__BUILTIN__"
+ 2136      | "__ATTRIBUTE__" [ "__BUILTIN__" ] [ "(" "(" ident ")" ")" ] .
+ 2137  
+ 2138    ProcHeading<VAR pn: SymTab.Name; methCls: SymTab.TypeIndex>
+ 2139                                          (. VAR t: SymTab.TypeIndex;
+ 2140                                               mg: QbeGen.QVal; .)
+ 2141      = "PROCEDURE"
+ 2142        [ ProcPragma ]
+ 2143        GetIdent<pn>                      (. IF methCls #
+ 2144                                                SymTab.InvalidType THEN
+ 2145                                             (* a method: resume the
+ 2146                                                declared symbol (reuse
+ 2147                                                its uid) *)
+ 2148                                             IF NOT SymTab.ResumeMethod(
+ 2149                                                  methCls, pn) THEN
+ 2150                                               SemError(200) END
+ 2151                                             ELSIF NOT SymTab.EnterProc(pn) THEN
+ 2152                                             IF NOT SymTab.ReenterProc(pn) THEN
+ 2153                                               IF NOT SymTab.ResumeProc(pn) THEN
+ 2154                                                 SemError(200) END
+ 2155                                               END
+ 2156                                             END;
+ 2157                                             Lower.ScopeEnter;
+ 2158                                             Lower.NoteProc(pn,
+ 2159                                               SymTab.ProcUid(pn),
+ 2160                                               SymTab.InvalidType,
+ 2161                                               SymTab.ProcDepthOf(pn),
+ 2162                                               FALSE);
+ 2163                                             QbeGen.BeginFunc("");
+ 2164                                             IF methCls #
+ 2165                                                SymTab.InvalidType THEN
+ 2166                                               (* hidden THIS receiver:
+ 2167                                                  a VAR param of the
+ 2168                                                  class type, pushed as
+ 2169                                                  the WITH base *)
+ 2170                                               IF NOT SymTab.EnterThisParam(
+ 2171                                                    methCls) THEN
+ 2172                                                 SemError(200) END;
+ 2173                                               IF NOT QbeGen.FuncParam(
+ 2174                                                    "THIS", TRUE,
+ 2175                                                    methCls) THEN
+ 2176                                                 SemError(233) END
+ 2177                                             END; .)
+ 2178        [ FormalParams ]
+ 2179        [ ":" ( TypeIdent<t>              (. IF NOT SymTab.SetProcRes(t) THEN
+ 2180                                               SemError(235) END;
+ 2181                                             Lower.SetProcRes(t); .)
+ 2182              | "PROC"                    (. (* PROC result: the procedure
+ 2183                                                value type *)
+ 2184                                             IF NOT SymTab.SetProcRes(
+ 2185                                                SymTab.AddrType()) THEN
+ 2186                                               SemError(235) END;
+ 2187                                             Lower.SetProcRes(
+ 2188                                               SymTab.AddrType()); .) ) ] .
+ 2189    FormalParams
+ 2190      = "(" [ ParamSection { ";" ParamSection } ] ")" .
+ 2191    ParamSection                          (. VAR t: SymTab.TypeIndex;
+ 2192                                               nm: SymTab.Name;
+ 2193                                               i: CARDINAL;
+ 2194                                               isV: BOOLEAN; .)
+ 2195      =                                   (. isV := FALSE; .)
+ 2196        [ "VAR"                           (. isV := TRUE; .) ]
+ 2197        ParIdents<isV> ":" Type<t, TRUE>  (. i := 0;
+ 2198                                             WHILE i < SymTab.PendCount() DO
+ 2199                                               SymTab.PendName(i, nm);
+ 2200                                               Lower.NoteParam(nm, t, isV);
+ 2201                                               Lower.NoteVar(nm, SymTab.KindParam, t);
+ 2202                                               (* value open arrays are
+ 2203                                                  passed as descriptor
+ 2204                                                  addresses (no copy):
+ 2205                                                  same representation as
+ 2206                                                  VAR formals *)
+ 2207                                               IF NOT QbeGen.FuncParam(nm,
+ 2208                                                    isV
+ 2209                                                    OR SymTab.IsOpenArray(t),
+ 2210                                                    t) THEN
+ 2211                                                 SemError(233) END;
+ 2212                                               INC(i)
+ 2213                                             END;
+ 2214                                             IF NOT SymTab.FixPending(t) THEN
+ 2215                                               SemError(235) END; .) .
+ 2216    (* Nested procedures lower like top-level ones (4.2): the
+ 2217       static link gives them their parent's frame. Methods keep
+ 2218       parse-now/230-later. *)
+ 2219    ProcDecl                              (. VAR pn: SymTab.Name;
+ 2220                                               saveFun: SymTab.Name;
+ 2221                                               astNode: AST.Node; .)
+ 2222      = ProcHeading<pn, SymTab.InvalidType> ";"
+ 2223                                          (. astNode := AST.MakeNode(AST.NkProcDecl);
+ 2224                                             AST.SetOp(astNode, 0);
+ 2225                                             AST.SetChild(astNode, 0,
+ 2226                                               AST.MakeLeaf(AST.NkIdent, pn));
+ 2227                                             Lower.NoteProcNode(astNode); .)
+ 2228        ( "FORWARD"                       (. AST.SetOp(astNode, 1);
+ 2229                                             astDecl := astNode;
+ 2230                                             Lower.ScopeLeave;
+ 2231                                             SymTab.MarkFwd;
+ 2232                                             SymTab.CloseProc;
+ 2233                                             QbeGen.AbortFunc; .)
+ 2234        | "EXTERNAL"                      (. AST.SetOp(astNode, 2);
+ 2235                                             astDecl := astNode;
+ 2236                                             Lower.MarkProcExternal;
+ 2237                                             Lower.ScopeLeave;
+ 2238                                             SymTab.MarkExternal("");
+ 2239                                             SymTab.CloseProc;
+ 2240                                             QbeGen.AbortFunc; .)
+ 2241        |                                 
+ 2242          (. allowDefer := TRUE; deferredBody := FALSE;
+ 2243                                             curProcNode := astNode;
+ 2244                                             saveFun := curFun;
+ 2245                                             curFun := pn; .)
+ 2246          Block<pn>                       (. curFun := saveFun;
+ 2247                                             IF deferredBody THEN
+ 2248                                               (* body skipped: close like
+ 2249                                                  FORWARD (no body node) *)
+ 2250                                               astDecl := astNode;
+ 2251                                               Lower.ScopeLeave;
+ 2252                                               SymTab.CloseProc;
+ 2253                                               QbeGen.AbortFunc
+ 2254                                             ELSE
+ 2255                                               AST.SetChild(astNode, 1, astStmt);
+ 2256                                               AST.SetChild(astNode, 2, astBlkDecls);
+ 2257                                               astDecl := astNode;
+ 2258                                               Lower.ScopeLeave;
+ 2259                                               SymTab.CloseProc;
+ 2260                                               QbeGen.EndFunc(
+ 2261                                                 SymTab.ProcRes(pn))
+ 2262                                             END; .) ) .
+ 2263    Block<pn: SymTab.Name>                (. VAR m2: SymTab.Name; dfr: BOOLEAN;
+ 2264                                               astBody, astHandler: AST.Node;
+ 2265                                               hasExcept, saveHandler: BOOLEAN; .)
+ 2266      =                                   (. dfr := FALSE;
+ 2267                                             saveHandler := inHandler;
+ 2268                                             inHandler := FALSE;
+ 2269                                             astHandler := AST.NoNode;
+ 2270                                             hasExcept := FALSE;
+ 2271                                             IF allowDefer AND twoPhaseParse
+ 2272                                                AND NOT repassing THEN
+ 2273                                               dfr := DeferSkip(pn)
+ 2274                                             END;
+ 2275                                             allowDefer := FALSE;
+ 2276                                             .)
+ 2277        DeclSeq                           (. astBlkDecls := astDecl;
+ 2278                                             astStmt := AST.NoNode;
+ 2279                                             nLab := 0; nGot := 0; .)
+ 2280        [ "BEGIN"                         (. (* an empty body is still a
+ 2281                                               body: mark it so Lower
+ 2282                                               does not read it as a
+ 2283                                               definition heading *)
+ 2284                                             IF NOT dfr THEN
+ 2285                                               IF astStmt = AST.NoNode THEN
+ 2286                                                 astStmt :=
+ 2287                                                   AST.MakeNode(AST.NkBlock)
+ 2288                                               END
+ 2289                                             END; .)
+ 2290          [ StatSeq ] ]
+ 2291                                          (. astBody := astStmt; .)
+ 2292        [ "EXCEPT"                        (. (* M1: grammar/AST only; M2 removes
+ 2293                                                this 230 and adds codegen. *)
+ 2294                                             SemError(230);
+ 2295                                             hasExcept := TRUE;
+ 2296                                             inHandler := TRUE; .)
+ 2297          [ StatSeq ]                     (. astHandler := astStmt;
+ 2298                                             inHandler := FALSE .) ]
+ 2299        "END"
+ 2300        GetIdent<m2>                      (. IF NOT SymTab.Equal(pn, m2) THEN
+ 2301                                               SemError(202) END;
+ 2302                                             inHandler := saveHandler;
+ 2303                                             IF hasExcept THEN
+ 2304                                               astStmt := WrapExcept(astBody,
+ 2305                                                             astHandler)
+ 2306                                             END;
+ 2307                                             CheckGotos; .) .
+ 2308    (* Two-phase, phase 2 (milestone 2c): re-parse every deferred module-
+ 2309       level body once the unit's declarations are complete.  Inlined at
+ 2310       both call sites because a stand-alone epsilon production is
+ 2311       "unreachable" to Coco/R (referenced only from actions). *)
+ 2312    StatSeq                               (. VAR astSeq, astTail: AST.Node; .)
+ 2313      =                                   (. astSeq := AST.NoNode;
+ 2314                                             astTail := AST.NoNode; .)
+ 2315        Statement                         (. AstAppend(AST.NkBlock,
+ 2316                                               astSeq, astTail, astStmt); .)
+ 2317        { ";" [ Statement                 (. AstAppend(AST.NkBlock,
+ 2318                                               astSeq, astTail, astStmt); .) ] }
+ 2319                                          (. astStmt := astSeq; .) .
+ 2320    (* Trailing/empty statements (`a; ; b`, Coco/R's generated `;;`)
+ 2321       are accepted: the statement after ';' is optional. *)
+ 2322    Statement                             (. VAR lx: QbeGen.QVal; lxnm: SymTab.Name; .)
+ 2323      = (. astStmt := AST.NoNode; .)
+ 2324        ( AssOrCall
+ 2325      | IfStat
+ 2326      | WhileStat
+ 2327      | RepeatStat
+ 2328      | LoopStat
+ 2329      | ForStat
+ 2330      | CaseStat
+ 2331      | WithStat
+ 2332      | ReturnStat
+ 2333      | HaltStat
+ 2334      | NewStat
+ 2335      | DisposeStat
+ 2336      | IncDecStat
+ 2337      | InclExclStat
+ 2338      | "EXIT"                            (. IF NOT QbeGen.TopLoop(lx) THEN
+ 2339                                               SemError(230) END;
+ 2340                                             astStmt := AST.MakeNode(AST.NkExit); .)
+ 2341      | "RETRY"                           (. IF NOT inHandler THEN
+ 2342                                               SemError(237) END;
+ 2343                                             astStmt := AST.MakeNode(AST.NkRetry); .)
+ 2344      | "GOTO" GetIdent<lxnm>             (. NoteGoto(lxnm);
+ 2345                                             astStmt := AST.MakeNode(AST.NkGoto);
+ 2346                                             AST.SetChild(astStmt, 0,
+ 2347                                               AST.MakeLeaf(AST.NkIdent, lxnm)); .) ) .
+ 2348    (* INCL(set, elem) / EXCL(set, elem): PIM set-element builtins. *)
+ 2349    InclExclStat                          (. VAR at, et2: SymTab.TypeIndex;
+ 2350                                               dk: INTEGER;
+ 2351                                               qd, qe: QbeGen.QVal;
+ 2352                                               qn: SymTab.Name;
+ 2353                                               sfx, isInc: BOOLEAN;
+ 2354                                               astNode, astD: AST.Node; .)
+ 2355      = ( "INCL"                          (. isInc := TRUE; .)
+ 2356        | "EXCL"                          (. isInc := FALSE; .) )
+ 2357        "(" Design<at, dk, qd, qn, sfx> (. astD := astCur; .) ","
+ 2358        Expr<et2, qe> ")"
+ 2359                                          (. astNode := AST.MakeNode(AST.NkCall);
+ 2360                                             IF isInc THEN
+ 2361                                               AST.SetChild(astNode, 0,
+ 2362                                                 AST.MakeLeaf(AST.NkIdent, "INCL"))
+ 2363                                             ELSE AST.SetChild(astNode, 0,
+ 2364                                                 AST.MakeLeaf(AST.NkIdent, "EXCL"))
+ 2365                                             END;
+ 2366                                             IF astD # AST.NoNode THEN
+ 2367                                               AST.SetChild(astNode, 1, astD) END;
+ 2368                                             IF astCur # AST.NoNode THEN
+ 2369                                               AST.SetChild(astNode, 2, astCur) END;
+ 2370                                             astStmt := astNode; .)
+ 2371                                          (. IF (at # SymTab.InvalidType)
+ 2372    AND (SymTab.ClassOf(at) # SymTab.ClSet) THEN
+ 2373                                               SemError(222)
+ 2374                                             END; .) .
+ 2375    (* INC(v [,step]) / DEC(v [,step]) as builtin statements over an
+ 2376       integer designator. *)
+ 2377    IncDecStat                            (. VAR dt, et2: SymTab.TypeIndex;
+ 2378                                               dk: INTEGER;
+ 2379                                               qd, qv, qn2, qstep:
+ 2380                                                 QbeGen.QVal;
+ 2381                                               qn: SymTab.Name;
+ 2382                                               sfx, isInc: BOOLEAN;
+ 2383                                               astNode, astD, astStep:
+ 2384                                                 AST.Node; .)
+ 2385      =                                   (. isInc := TRUE; .)
+ 2386        ( "INC"                           (. isInc := TRUE; .)
+ 2387        | "DEC"                           (. isInc := FALSE; .) )
+ 2388        "("                               (. astStep := AST.NoNode; .)
+ 2389        Design<dt, dk, qd, qn, sfx> (. astD := astCur; .)
+ 2390        [ "," Expr<et2, qstep> (. astStep := astCur; .) ]
+ 2391        ")"                               (. astNode := AST.MakeNode(AST.NkCall);
+ 2392                                             IF isInc THEN
+ 2393                                               AST.SetChild(astNode, 0,
+ 2394                                                 AST.MakeLeaf(AST.NkIdent, "INC"))
+ 2395                                             ELSE AST.SetChild(astNode, 0,
+ 2396                                                 AST.MakeLeaf(AST.NkIdent, "DEC"))
+ 2397                                             END;
+ 2398                                             IF astD # AST.NoNode THEN
+ 2399                                               AST.SetChild(astNode, 1, astD) END;
+ 2400                                             IF astStep # AST.NoNode THEN
+ 2401                                               AST.SetChild(astNode, 2, astStep) END;
+ 2402                                             astStmt := astNode; .)                               (. IF dt = SymTab.InvalidType THEN
+ 2403                                             ELSIF (dk # SymTab.KindVar)
+ 2404   AND (dk # SymTab.KindParam)
+ 2405   AND (dk # SymTab.KindField) THEN
+ 2406                                               SemError(210)
+ 2407                                             ELSIF NOT SymTab.IsOrdinal(dt) THEN
+ 2408                                               SemError(211)
+ 2409                                             END; .) .
+ 2410    (* NEW/DISPOSE as builtin statements (no call syntax until step 4).
+ 2411       Targets are pointer designators; DISPOSE nils afterwards (safer
+ 2412       than Wirth-undefined; documented). DISPOSE is shallow. *)
+ 2413    NewStat                               (. VAR dt: SymTab.TypeIndex;
+ 2414                                               dk: INTEGER;
+ 2415                                               qd, qm: QbeGen.QVal;
+ 2416                                               qn: SymTab.Name;
+ 2417                                               sfx: BOOLEAN;
+ 2418                                               bt: SymTab.TypeIndex;
+ 2419                                               astNode, astD: AST.Node; .)
+ 2420      = "NEW" "(" Design<dt, dk, qd, qn, sfx> (. astD := astCur; .) ")"
+ 2421                                          (. astNode := AST.MakeNode(AST.NkCall);
+ 2422                                             AST.SetChild(astNode, 0,
+ 2423                                               AST.MakeLeaf(AST.NkIdent, "NEW"));
+ 2424                                             IF astD # AST.NoNode THEN
+ 2425                                               AST.SetChild(astNode, 1, astD) END;
+ 2426                                             astStmt := astNode; .)
+ 2427                                           (. IF dt = SymTab.InvalidType THEN
+ 2428                                              ELSIF (dk # SymTab.KindVar)
+ 2429    AND (dk # SymTab.KindParam)
+ 2430    AND (dk # SymTab.KindField) THEN
+ 2431                                                SemError(210)
+ 2432                                              ELSIF SymTab.ClassOf(dt) #
+ 2433                                                    SymTab.ClPtr THEN
+ 2434                                                SemError(219)
+ 2435                                              END; .) .
+ 2436    DisposeStat                           (. VAR dt: SymTab.TypeIndex;
+ 2437                                               dk: INTEGER;
+ 2438                                               qd, qv: QbeGen.QVal;
+ 2439                                               qn: SymTab.Name;
+ 2440                                               sfx: BOOLEAN;
+ 2441                                               astNode, astD: AST.Node; .)
+ 2442      = "DISPOSE" "(" Design<dt, dk, qd, qn, sfx> (. astD := astCur; .) ")"
+ 2443                                          (. astNode := AST.MakeNode(AST.NkCall);
+ 2444                                             AST.SetChild(astNode, 0,
+ 2445                                               AST.MakeLeaf(AST.NkIdent, "DISPOSE"));
+ 2446                                             IF astD # AST.NoNode THEN
+ 2447                                               AST.SetChild(astNode, 1, astD) END;
+ 2448                                             astStmt := astNode; .)
+ 2449                                           (. IF dt = SymTab.InvalidType THEN
+ 2450                                              ELSIF (dk # SymTab.KindVar)
+ 2451    AND (dk # SymTab.KindParam)
+ 2452    AND (dk # SymTab.KindField) THEN
+ 2453                                                SemError(210)
+ 2454                                              ELSIF SymTab.ClassOf(dt) #
+ 2455                                                    SymTab.ClPtr THEN
+ 2456                                                SemError(219)
+ 2457                                              END; .) .
+ 2458    (* WITH pushes each record's fields (inner wins) plus its base
+ 2459       address; field designators resolve through both stacks. *)
+ 2460    WithStat                              (. VAR nW: CARDINAL;
+ 2461                                               astNode: AST.Node; .)
+ 2462      = "WITH"                            (. nW := 0;
+ 2463                                             astNode := AST.MakeNode(AST.NkWith); .)
+ 2464        WithItem<nW, astNode> { "," WithItem<nW, astNode> }
+ 2465        "DO"                              (. astStmt := AST.NoNode; .)
+ 2466        [ StatSeq ] "END"                 (. AST.SetChild(astNode,
+ 2467                                             AST.NChild(astNode), astStmt);
+ 2468                                             astStmt := astNode;
+ 2469                                             WHILE nW > 0 DO
+ 2470                                               SymTab.PopScope;
+ 2471                                               QbeGen.PopWith;
+ 2472                                               DEC(nW)
+ 2473                                             END; .) .
+ 2474    WithItem<VAR nW: CARDINAL; wnode: AST.Node>
+ 2475                                          (. VAR dt: SymTab.TypeIndex;
+ 2476                                               dk: INTEGER;
+ 2477                                               qd, qe: QbeGen.QVal;
+ 2478                                               qn: SymTab.Name;
+ 2479                                               sfx: BOOLEAN; .)
+ 2480      = Design<dt, dk, qd, qn, sfx>
+ 2481                                          (. IF astCur # AST.NoNode THEN
+ 2482                                               AST.SetChild(wnode,
+ 2483                                                 AST.NChild(wnode), astCur) END;
+ 2484                                             IF dt = SymTab.InvalidType THEN
+ 2485                                             ELSIF (SymTab.ClassOf(dt) #
+ 2486                                                    SymTab.ClRecord)
+ 2487   AND (SymTab.ClassOf(dt) #
+ 2488                                                   SymTab.ClClass) THEN
+ 2489                                               SemError(215)
+ 2490                                             ELSIF SymTab.PushRecord(dt) THEN
+ 2491                                               QbeGen.PushWith(qd);
+ 2492                                               INC(nW)
+ 2493                                             END; .) .
+ 2494    (* Assignment or procedure-statement call (4.1, module level).
+ 2495       Bare `P;` is a syntax error; function-as-statement is 233. *)
+ 2496    AssOrCall                             (. VAR dt, et: SymTab.TypeIndex;
+ 2497                                               dk: INTEGER;
+ 2498                                               qd, qe, qt, ql: QbeGen.QVal;
+ 2499                                               qn: SymTab.Name;
+ 2500                                               ct2, res0: SymTab.TypeIndex;
+ 2501                                               q2, mg0: QbeGen.QVal;
+ 2502                                               isR, conv, wconv: BOOLEAN;
+ 2503                                               called, sfx: BOOLEAN;
+ 2504                                               astLhs, astRes: AST.Node; mname: SymTab.Name; isM: BOOLEAN;
+ 2505                                               n: SymTab.Name; astLab, astNode: AST.Node; .)
+ 2506      = GetIdent<n>
+ 2507        ( ":"                             (. NoteLabel(n);
+ 2508                                             astNode := AST.MakeNode(AST.NkLabel);
+ 2509                                             AST.SetChild(astNode, 0,
+ 2510                                               AST.MakeLeaf(AST.NkIdent, n));
+ 2511                                             astLab := AST.MakeNode(AST.NkBlock);
+ 2512                                             AST.SetChild(astLab, 0, astNode); .)
+ 2513          Statement                       (. IF astStmt # AST.NoNode THEN
+ 2514                                               AST.SetChild(astLab, 1, astStmt) END;
+ 2515                                             astStmt := astLab; .)
+ 2516        | DesignTail<n, dt, dk, qd, qn, sfx>
+ 2517        (. astLhs := astCur; astNArgs := 0; .)
+ 2518        ( ":="
+ 2519          Expr<et, qe>                    (. astStmt := AST.MakeBin(
+ 2520                                               AST.NkAssign, 0, astLhs, astCur);
+ 2521                                             IF (dt # SymTab.InvalidType)
+ 2522   AND (dk # SymTab.KindVar)
+ 2523   AND (dk # SymTab.KindParam)
+ 2524   AND (dk # SymTab.KindField) THEN
+ 2525                                             SemError(210)
+ 2526                                           ELSIF NOT SymTab.Assignable(et,
+ 2527                                                    dt) THEN
+ 2528                                             SemError(210)
+ 2529                                           ELSIF (dt # SymTab.InvalidType)
+ 2530   AND (SymTab.ClassOf(dt) =
+ 2531                                                 SymTab.ClClass) THEN
+ 2532                                             SemError(230) END;
+ 2533                                           isR := (dt #
+ 2534                                                   SymTab.InvalidType)
+ 2535   AND (SymTab.ClassOf(dt)
+ 2536                                                     = SymTab.ClReal);
+ 2537                                           conv := isR
+ 2538   AND SymTab.IsIntFamily(et);
+ 2539                                           wconv := (dt #
+ 2540                                                     SymTab.InvalidType)
+ 2541   AND SymTab.IsLongFamily(dt)
+ 2542   AND SymTab.IsIntFamily(et);
+ 2543                                           IF ((dk = SymTab.KindVar)
+ 2544                                               OR (dk = SymTab.KindParam)
+ 2545                                               OR (dk = SymTab.KindField))
+ 2546   AND (dt # SymTab.InvalidType)
+ 2547   AND (et # SymTab.InvalidType)
+ 2548   AND (SymTab.ClassOf(dt) #
+ 2549                                                 SymTab.ClClass) THEN
+ 2550                                           END; .)
+ 2551        | ArgList<qn, dt, qd, TRUE, TRUE, methCls, ct2, q2, called>
+ 2552                                          (. astRes := AstCallNode(astLhs);
+ 2553                                             sfx := FALSE; .)
+ 2554          ( { ResultComp<ct2, q2, sfx, astRes, mname, methCls, isM> }
+ 2555            ":=" Expr<et, qe>             (. astStmt := AST.MakeBin(
+ 2556                                               AST.NkAssign, 0, astRes, astCur);
+ 2557                                             IF NOT sfx THEN
+ 2558                                               SemError(233)
+ 2559                                             ELSIF (ct2 # SymTab.InvalidType)
+ 2560    AND NOT SymTab.Assignable(et, ct2) THEN
+ 2561                                               SemError(210)
+ 2562                                             END; .)
+ 2563          |                               (. (* discarding the result of a
+ 2564                                               foreign C varargs call
+ 2565                                               (printf/snprintf) is accepted;
+ 2566                                               an ordinary Modula-2 function
+ 2567                                               used as a statement stays 233 *)
+ 2568                                             IF (ct2 # SymTab.InvalidType)
+ 2569                                                AND NOT SymTab.Varargs(qn) THEN
+ 2570                                               SemError(233) END;
+ 2571                                             astStmt := astRes; .) )
+ 2572        |                                 (* bare `P;`: proper parameterless
+ 2573                                              procedure call; anything else
+ 2574                                              here is 233 (was a bare syntax
+ 2575                                              error before 4.2) *)
+ 2576                                          (. astStmt := AstCallNode(astLhs);
+ 2577                                              IF (dk = SymTab.KindProc)
+ 2578   AND NOT sfx THEN
+ 2579                                               res0 := SymTab.ProcRes(qn);
+ 2580                                               IF res0 #
+ 2581                                                  SymTab.InvalidType THEN
+ 2582                                                 SemError(233)
+ 2583                                               ELSIF SymTab.ProcNPar(qn) #
+ 2584                                                       0 THEN
+ 2585                                                 SemError(233)
+ 2586                                               END
+ 2587                                             ELSIF (dt # SymTab.InvalidType)
+ 2588    AND (SymTab.ClassOf(dt) = SymTab.ClProc) THEN
+ 2589                                               IF SymTab.ProcTypeRes(dt) #
+ 2590                                                  SymTab.InvalidType THEN
+ 2591                                                 SemError(233)
+ 2592                                               ELSIF SymTab.ProcTypeNPar(dt) #
+ 2593                                                       0 THEN
+ 2594                                                 SemError(233)
+ 2595                                               END
+ 2596                                             ELSE SemError(233)
+ 2597                                              END; .) ) ) .
+ 2598    (* Actual-parameter list shared by statement and expression calls.
+ 2599       want selects CallEnd's result handling; t/q carry the call
+ 2600       value (statement calls discard). Arity/type failures are 233;
+ 2601       evaluation code still emits so the .ssa stays assembleable. *)
+ 2602    ArgList<pn: SymTab.Name; pt: SymTab.TypeIndex; callee: QbeGen.QVal;
+ 2603            want: BOOLEAN; soft: BOOLEAN; methCls: SymTab.TypeIndex;
+ 2604            VAR t: SymTab.TypeIndex; VAR q: QbeGen.QVal;
+ 2605            VAR called: BOOLEAN>          (. VAR i, np: CARDINAL;
+ 2606                                               vs: INTEGER;
+ 2607                                               res: SymTab.TypeIndex;
+ 2608                                               mg: QbeGen.QVal;
+ 2609                                               ok, ind, isMeth, va, isConv: BOOLEAN; .)
+ 2610      = "("                               (. called := TRUE;
+ 2611                                             ok := TRUE;
+ 2612                                             ind := FALSE;
+ 2613                                             isConv := FALSE;
+ 2614                                             isMeth := methCls #
+ 2615                                               SymTab.InvalidType;
+ 2616                                             IF isMeth THEN
+ 2617                                               res := SymTab.ClassMethodRes(methCls, pn)
+ 2618                                             ELSIF SymTab.SymKind(pn) = SymTab.KindProc THEN
+ 2619                                               res := SymTab.ProcRes(pn)
+ 2620                                             ELSIF (SymTab.SymKind(pn) = SymTab.KindType)
+ 2621    OR (SymTab.SymKind(pn) = SymTab.KindPredef) THEN
+ 2622                                               (* ISO type conversion T(x):
+ 2623                                                  one value, result is T *)
+ 2624                                               isConv := TRUE;
+ 2625                                               res := SymTab.SymType(pn)
+ 2626                                             ELSIF (pt # SymTab.InvalidType)
+ 2627    AND (SymTab.ClassOf(pt) = SymTab.ClProc) THEN
+ 2628                                               ind := TRUE;
+ 2629                                               res := SymTab.ProcTypeRes(pt)
+ 2630                                             ELSE SemError(233);
+ 2631                                               ok := FALSE;
+ 2632                                               res := SymTab.InvalidType
+ 2633                                             END;
+ 2634                                             i := 0; .)
+ 2635        [ ActParam<pn, pt, ind, methCls, i>        (. INC(i); .)
+ 2636          { "," ActParam<pn, pt, ind, methCls, i>  (. INC(i); .) } ]
+ 2637        ")"                               (. IF ok THEN
+ 2638                                               IF isConv THEN
+ 2639                                                 (* a conversion takes
+ 2640                                                    exactly one value *)
+ 2641                                                 IF i # 1 THEN
+ 2642                                                   SemError(233); ok := FALSE
+ 2643                                                 END
+ 2644                                               ELSE
+ 2645                                                 IF isMeth THEN
+ 2646                                                   np := SymTab.ClassMethodNPar(
+ 2647                                                     methCls, pn)
+ 2648                                                 ELSIF ind THEN
+ 2649                                                   np := SymTab.ProcTypeNPar(pt)
+ 2650                                                 ELSE np := SymTab.ProcNPar(pn)
+ 2651                                                 END;
+ 2652                                                 va := (NOT isMeth) AND (NOT ind)
+ 2653                                                   AND (SymTab.SymKind(pn) =
+ 2654                                                        SymTab.KindProc)
+ 2655                                                   AND SymTab.Varargs(pn);
+ 2656                                                 IF (i # np) AND NOT va THEN
+ 2657                                                   SemError(233); ok := FALSE
+ 2658                                                 END
+ 2659                                               END
+ 2660                                             END;
+ 2661                                             IF NOT ok THEN
+ 2662                                               t := SymTab.InvalidType;
+ 2663                                               QbeGen.CopyOp("0", q)
+ 2664                                             ELSIF want THEN
+ 2665                                               IF res =
+ 2666                                                  SymTab.InvalidType THEN
+ 2667                                                 IF NOT soft THEN SemError(233) END;
+ 2668                                                 t := SymTab.InvalidType;
+ 2669                                                 QbeGen.CopyOp("0", q)
+ 2670                                               ELSE t := res;
+ 2671                                                  QbeGen.CopyOp("@", q)
+ 2672                                               END
+ 2673                                             ELSE
+ 2674                                               (* a function call used as
+ 2675                                                  a statement: allowed for
+ 2676                                                  a foreign C varargs proc
+ 2677                                                  (printf/snprintf), whose
+ 2678                                                  result is conventionally
+ 2679                                                  discarded; ordinary
+ 2680                                                  Modula-2 functions keep
+ 2681                                                  the 233 diagnostic *)
+ 2682                                               IF (res # SymTab.InvalidType)
+ 2683                                                  AND NOT va THEN
+ 2684                                                 SemError(233)
+ 2685                                               END;
+ 2686                                               t := SymTab.InvalidType;
+ 2687                                               QbeGen.CopyOp("0", q);
+ 2688                                             END; .) .
+ 2689    (* One actual: VAR formals take recorded designator addresses
+ 2690       (233 otherwise); value formals take converted expressions. *)
+ 2691    ActParam<pn: SymTab.Name; pt: SymTab.TypeIndex; ind: BOOLEAN;
+ 2692             methCls: SymTab.TypeIndex; i: CARDINAL>
+ 2693                                          (. VAR at, ft: SymTab.TypeIndex;
+ 2694                                               qe, qa, qt: QbeGen.QVal;
+ 2695                                               isV, conv, va: BOOLEAN;
+ 2696                                               cl: CHAR;
+ 2697                                               savedN, aj: CARDINAL;
+ 2698                                               savedArgs: ARRAY [0 .. 31]
+ 2699                                                 OF AST.Node;
+ 2700                                               astActual: AST.Node; .)
+ 2701      =                                   (. (* Parsing the actual can clobber
+ 2702                                               the enclosing call's argument
+ 2703                                               list (Factor resets astNArgs),
+ 2704                                               so save/restore it. *)
+ 2705                                             savedN := astNArgs; aj := 0;
+ 2706                                             WHILE aj <= HIGH(astArgs) DO
+ 2707                                               savedArgs[aj] := astArgs[aj];
+ 2708                                               INC(aj)
+ 2709                                             END; .)
+ 2710        Expr<at, qe>                      (. QbeGen.CopyOp(qe, convQ); convT := at;
+ 2711                                             astActual := astCur;
+ 2712                                             astNArgs := savedN; aj := 0;
+ 2713                                             WHILE aj <= HIGH(astArgs) DO
+ 2714                                               astArgs[aj] := savedArgs[aj];
+ 2715                                               INC(aj)
+ 2716                                             END;
+ 2717                                             IF astNArgs <= HIGH(astArgs) THEN
+ 2718                                               astArgs[astNArgs] := astCur;
+ 2719                                               INC(astNArgs)
+ 2720                                             ELSE SemError(230)
+ 2721                                               (* > 32 actuals: impl limit *)
+ 2722                                             END;
+ 2723                                             va := (NOT ind)
+ 2724                                               AND (methCls =
+ 2725                                                  SymTab.InvalidType)
+ 2726                                               AND (SymTab.SymKind(pn) =
+ 2727                                                  SymTab.KindProc)
+ 2728                                               AND SymTab.Varargs(pn);
+ 2729                                             IF ind THEN
+ 2730                                               ft :=
+ 2731                                                 SymTab.ProcTypeParamType(pt,
+ 2732                                                   i);
+ 2733                                               isV :=
+ 2734                                                 SymTab.ProcTypeParamIsVar(pt,
+ 2735                                                   i)
+ 2736                                             ELSIF methCls #
+ 2737                                                SymTab.InvalidType THEN
+ 2738                                               ft :=
+ 2739                                                 SymTab.ClassMethodParamType(
+ 2740                                                 methCls, pn, i);
+ 2741                                               isV :=
+ 2742                                                 SymTab.ClassMethodParamIsVar(
+ 2743                                                 methCls, pn, i)
+ 2744                                             ELSE
+ 2745                                               ft := SymTab.ParamType(pn, i);
+ 2746                                               isV := SymTab.ParamIsVar(pn, i)
+ 2747                                             END;
+ 2748                                             IF (at = SymTab.InvalidType) THEN
+ 2749                                             ELSIF ft = SymTab.InvalidType THEN
+ 2750                                             ELSIF isV THEN
+ 2751                                               IF (SymTab.ClassOf(at) = SymTab.ClChar)
+ 2752    AND (SymTab.ClassOf(ft) = SymTab.ClArray)
+ 2753    AND (SymTab.ClassOf(SymTab.ArrayElem(ft)) = SymTab.ClChar)
+ 2754    AND QbeGen.IsImm(qe) THEN
+ 2755                                               ELSIF (AST.Kind(astActual) #
+ 2756                                                      AST.NkDesignator)
+ 2757    AND (AST.Kind(astActual) # AST.NkStrLit) THEN
+ 2758                                                 SemError(233)
+ 2759                                               ELSIF NOT SymTab.VarParamOk(at, ft)
+ 2760     AND NOT SymTab.ByteBufOk(at, ft) THEN
+ 2761                                                 SemError(233)
+ 2762                                               END
+ 2763                                             ELSE
+ 2764                                               IF (SymTab.ClassOf(at) = SymTab.ClChar)
+ 2765    AND (SymTab.ClassOf(ft) = SymTab.ClArray)
+ 2766    AND (SymTab.ClassOf(SymTab.ArrayElem(ft)) = SymTab.ClChar)
+ 2767    AND QbeGen.IsImm(qe) THEN
+ 2768                                               ELSIF NOT SymTab.Assignable(at, ft)
+ 2769     AND NOT SymTab.ByteBufOk(at, ft) THEN
+ 2770                                                 SemError(233)
+ 2771                                               END
+ 2772                                             END; .) .
+ 2773    IfStat                                (. VAR t: SymTab.TypeIndex;
+ 2774                                               q: QbeGen.QVal;
+ 2775                                               hasElse: BOOLEAN;
+ 2776                                               astCond, astIf, astLast,
+ 2777                                               astNode: AST.Node; .)
+ 2778      = "IF" (. hasElse := FALSE; .)
+ 2779        Expr<t, q> (. astCond := astCur; astStmt := AST.NoNode;
+ 2780                                             IF NOT SymTab.BoolCheck(t) THEN
+ 2781                                               SemError(214) END; .)
+ 2782        "THEN" [ StatSeq ]                (. astNode := AST.MakeNode(AST.NkIf);
+ 2783                                             AST.SetChild(astNode, 0, astCond);
+ 2784                                             AST.SetChild(astNode, 1, astStmt);
+ 2785                                             astIf := astNode;
+ 2786                                             astLast := astNode; .)
+ 2787        { "ELSIF"
+ 2788          Expr<t, q> (. astCond := astCur; astStmt := AST.NoNode;
+ 2789                                             IF NOT SymTab.BoolCheck(t) THEN
+ 2790                                               SemError(214) END; .)
+ 2791          "THEN" [ StatSeq ]              (. astNode := AST.MakeNode(AST.NkIf);
+ 2792                                             AST.SetChild(astNode, 0, astCond);
+ 2793                                             AST.SetChild(astNode, 1, astStmt);
+ 2794                                             AST.SetChild(astLast, 2, astNode);
+ 2795                                             astLast := astNode; .) }
+ 2796        [ "ELSE"                          (. hasElse := TRUE;
+ 2797                                             astStmt := AST.NoNode; .)
+ 2798          [ StatSeq ] (. AST.SetChild(astLast, 2, astStmt); .) ]
+ 2799        "END" (. astStmt := astIf; .) .
+ 2800    WhileStat                             (. VAR t: SymTab.TypeIndex;
+ 2801                                               q: QbeGen.QVal;
+ 2802                                               astCond, astNode: AST.Node; .)
+ 2803      = "WHILE" (. astStmt := AST.NoNode; .)
+ 2804        Expr<t, q> (. astCond := astCur;
+ 2805                                             IF NOT SymTab.BoolCheck(t) THEN
+ 2806                                               SemError(214) END; .)
+ 2807        "DO" [ StatSeq ]                  (. astNode := AST.MakeNode(AST.NkWhile);
+ 2808                                             AST.SetChild(astNode, 0, astCond);
+ 2809                                             AST.SetChild(astNode, 1, astStmt);
+ 2810                                             astStmt := astNode; .)
+ 2811        "END" .
+ 2812    RepeatStat                            (. VAR t: SymTab.TypeIndex;
+ 2813                                               q: QbeGen.QVal;
+ 2814                                               astCond, astBody, astNode:
+ 2815                                                 AST.Node; .)
+ 2816      = "REPEAT" (. astStmt := AST.NoNode; .)
+ 2817        [ StatSeq ] (. astBody := astStmt; .)
+ 2818        "UNTIL" Expr<t, q> (. astCond := astCur;
+ 2819                                             astNode := AST.MakeNode(AST.NkRepeat);
+ 2820                                             AST.SetChild(astNode, 0, astBody);
+ 2821                                             AST.SetChild(astNode, 1, astCond);
+ 2822                                             astStmt := astNode;
+ 2823                                             IF NOT SymTab.BoolCheck(t) THEN
+ 2824                                               SemError(214) END; .) .
+ 2825    LoopStat                              (. VAR lEnd: QbeGen.QVal; astNode: AST.Node; .)
+ 2826      = "LOOP"                            (. astStmt := AST.NoNode;
+ 2827                                             QbeGen.NewLabel(lEnd);
+ 2828                                             QbeGen.PushLoop(lEnd); .)
+ 2829        [ StatSeq ]
+ 2830        "END"                             (. astNode := AST.MakeNode(AST.NkLoop);
+ 2831                                             AST.SetChild(astNode, 0, astStmt);
+ 2832                                             astStmt := astNode;
+ 2833                                             QbeGen.PopLoop; .) .
+ 2834    (* FOR with static-sign BY (literal, non-zero; 220 otherwise).
+ 2835       Runtime direction would need a compare-select; the literal
+ 2836       sign picks cslew/csegew at "DO" time. *)
+ 2837    ForStat                               (. VAR lv: SymTab.Name;
+ 2838                                               tlo, thi, tby:
+ 2839                                                 SymTab.TypeIndex;
+ 2840                                               qlo, qhi, qby, qt, qk, qb:
+ 2841                                                 QbeGen.QVal;
+ 2842                                               lTop, lBody, lEnd:
+ 2843                                                 QbeGen.QVal;
+ 2844                                               by: INTEGER;
+ 2845                                               ok: BOOLEAN;
+ 2846                                               astVar, astLo, astHi, astBy,
+ 2847                                               astNode: AST.Node; .)
+ 2848      = "FOR"                             (. by := 1; .)
+ 2849        GetIdent<lv> (. astVar := AST.MakeLeaf(AST.NkIdent, lv);
+ 2850                                             astStmt := AST.NoNode;
+ 2851                                             astBy := AST.NoNode;
+ 2852                                             ok := SymTab.Lookup(lv);
+ 2853                                             IF NOT ok THEN
+ 2854                                               SemError(201)
+ 2855                                             ELSIF (SymTab.SymKind(lv) #
+ 2856                                                    SymTab.KindVar)
+ 2857   AND (SymTab.SymKind(lv) #
+ 2858                                                   SymTab.KindParam) THEN
+ 2859                                               SemError(220); ok := FALSE
+ 2860                                             ELSIF NOT SymTab.IsOrdinal(
+ 2861                                                     SymTab.SymType(lv)) THEN
+ 2862                                               SemError(220); ok := FALSE
+ 2863                                             END; .)
+ 2864        ":=" Expr<tlo, qlo> (. astLo := astCur;
+ 2865                                             IF NOT SymTab.Assignable(tlo,
+ 2866                                                  SymTab.SymType(lv)) THEN
+ 2867                                               SemError(220); ok := FALSE
+ 2868                                             END; .)
+ 2869        "TO" Expr<thi, qhi> (. astHi := astCur;
+ 2870                                             IF NOT SymTab.Assignable(thi,
+ 2871                                                  SymTab.SymType(lv)) THEN
+ 2872                                               SemError(220); ok := FALSE
+ 2873                                             END; .)
+ 2874        [ "BY" Expr<tby, qby> (. astBy := astCur;
+ 2875                                             IF (tby #
+ 2876                                               SymTab.InvalidType)
+ 2877   AND NOT SymTab.IsIntFamily(tby) THEN
+ 2878                                               SemError(220); ok := FALSE
+ 2879                                             END;
+ 2880                                             IF NOT SymTab.ConstInt(qby, by) THEN
+ 2881                                               SemError(230); by := 1
+ 2882                                             ELSIF by = 0 THEN
+ 2883                                               SemError(220); by := 1
+ 2884                                             END; .) ]
+ 2885        "DO"
+ 2886        [ StatSeq ]
+ 2887        "END" (. astNode := AST.MakeNode(AST.NkFor);
+ 2888                                             AST.SetChild(astNode, 0, astVar);
+ 2889                                             AST.SetChild(astNode, 1, astLo);
+ 2890                                             AST.SetChild(astNode, 2, astHi);
+ 2891                                             AST.SetChild(astNode, 3, astBy);
+ 2892                                             AST.SetChild(astNode, 4, astStmt);
+ 2893                                             astStmt := astNode;
+ 2894                                             .) .
+ 2895    CaseStat                              (. VAR tsel: SymTab.TypeIndex;
+ 2896                                               qsel, lEnd: QbeGen.QVal;
+ 2897                                               arm, astNode, astArms,
+ 2898                                               astArmsTail: AST.Node; .)
+ 2899      = "CASE" Expr<tsel, qsel>           (. astNode := AST.MakeNode(AST.NkCase);
+ 2900                                             AST.SetChild(astNode, 0, astCur);
+ 2901                                             astArms := AST.NoNode;
+ 2902                                             astArmsTail := AST.NoNode;
+ 2903                                             .)
+ 2904        "OF" [ "|" ] CaseAlt<tsel, qsel, lEnd, astArms, astArmsTail>
+ 2905        { "|" CaseAlt<tsel, qsel, lEnd, astArms, astArmsTail> }
+ 2906        [ "ELSE"                          (. astStmt := AST.NoNode; .)
+ 2907          [ StatSeq ]                     (. arm := AST.MakeNode(AST.NkCaseArm);
+ 2908                                             AST.SetOp(arm, 1);
+ 2909                                             AST.SetChild(arm, 0, astStmt);
+ 2910                                             AstAppend(AST.NkBlock,
+ 2911                                               astArms, astArmsTail, arm); .) ]
+ 2912        "END"                             (. AST.SetChild(astNode, 1, astArms);
+ 2913                                             astStmt := astNode;
+ 2914                                             .) .
+ 2915    (* Compare-chain lowering: each alternative ends its match-tests
+ 2916       with "jmp lAfter", so the no-match fallthrough skips the body:
+ 2917       "cmp; jnz(lBody,lF); lF: ... ; jmp lAfter; lBody: S; jmp lEnd;
+ 2918       lAfter:". Falls into the next alternative, ELSE, or END. *)
+ 2919    CaseAlt<tsel: SymTab.TypeIndex; qsel: QbeGen.QVal;
+ 2920            lEnd: QbeGen.QVal; VAR arms, armsTail: AST.Node>
+ 2921                                          (. VAR arm: AST.Node; .)
+ 2922      =                                   (. arm := AST.MakeNode(AST.NkCaseArm); .)
+ 2923        CaseLabel<tsel, qsel, arm>
+ 2924        { "," CaseLabel<tsel, qsel, arm> }
+ 2925        ":"                               (. astStmt := AST.NoNode; .)
+ 2926        [ StatSeq ]                       (. AST.SetChild(arm, AST.NChild(arm),
+ 2927                                             astStmt);
+ 2928                                             AstAppend(AST.NkBlock,
+ 2929                                               arms, armsTail, arm);
+ 2930                                             .) .
+ 2931    CaseLabel<tsel: SymTab.TypeIndex; qsel: QbeGen.QVal;
+ 2932              arm: AST.Node>
+ 2933                                          (. VAR t2, t3: SymTab.TypeIndex;
+ 2934                                               q2, q3, qc, qd, qe:
+ 2935                                                 QbeGen.QVal;
+ 2936                                               astLab: AST.Node;
+ 2937                                               lNext: QbeGen.QVal; .)
+ 2938      = Expr<t2, q2> (. astLab := astCur;
+ 2939                                             IF SymTab.IsEmptyStr(t2)
+ 2940                                                AND (SymTab.ClassOf(tsel) =
+ 2941                                                     SymTab.ClChar) THEN
+ 2942                                               (* ISO: '' as a CASE label
+ 2943                                                  is the terminator *)
+ 2944                                               QbeGen.CopyOp("0", q2);
+ 2945                                               t2 := SymTab.CharType()
+ 2946                                             END;
+ 2947                                             IF (t2 #
+ 2948                                               SymTab.InvalidType)
+ 2949   AND (tsel #
+ 2950                                                 SymTab.InvalidType)
+ 2951   AND NOT SymTab.EqCheck(t2,
+ 2952                                                   tsel) THEN
+ 2953                                               SemError(213) END;
+ 2954                                             (* set labels are not immediates:
+ 2955                                                the CASE chain uses CmpSet *)
+ 2956                                             IF (SymTab.ClassOf(t2) # SymTab.ClSet)
+ 2957   AND NOT QbeGen.IsImm(q2) THEN
+ 2958                                               SemError(230)
+ 2959                                             END; .)
+ 2960        [ ".." Expr<t3, q3>               (. astLab := AST.MakeBin(
+ 2961                                               AST.NkSubrange, 0, astLab, astCur);
+ 2962                                             IF SymTab.IsEmptyStr(t3)
+ 2963                                                AND (SymTab.ClassOf(tsel) =
+ 2964                                                     SymTab.ClChar) THEN
+ 2965                                               QbeGen.CopyOp("0", q3);
+ 2966                                               t3 := SymTab.CharType()
+ 2967                                             END;
+ 2968                                             IF (t3 #
+ 2969                                               SymTab.InvalidType)
+ 2970   AND (tsel #
+ 2971                                                 SymTab.InvalidType)
+ 2972   AND NOT SymTab.EqCheck(t3,
+ 2973                                                   tsel) THEN
+ 2974                                               SemError(213) END;
+ 2975                                                 IF (SymTab.ClassOf(t3) # SymTab.ClSet)
+ 2976   AND NOT QbeGen.IsImm(q3) THEN
+ 2977                                                   SemError(230)
+ 2978                                                 END; .) ]
+ 2979                                          (. AST.SetChild(arm,
+ 2980                                               AST.NChild(arm), astLab); .) .
+ 2981    ReturnStat                            (. VAR t: SymTab.TypeIndex;
+ 2982                                               q, qt: QbeGen.QVal;
+ 2983                                               res: SymTab.TypeIndex;
+ 2984                                               hadE, conv: BOOLEAN;
+ 2985                                               astVal, astNode: AST.Node; .)
+ 2986      = "RETURN"                          (. hadE := FALSE; astStmt := AST.NoNode; .)
+ 2987        [ Expr<t, q> (. hadE := TRUE; astVal := astCur; .) ]
+ 2988                                          (. astNode := AST.MakeNode(AST.NkReturn);
+ 2989                                             IF hadE THEN
+ 2990                                               AST.SetChild(astNode, 0, astVal)
+ 2991                                             END;
+ 2992                                             astStmt := astNode;
+ 2993                                             conv := FALSE;
+ 2994                                             IF NOT SymTab.InProc() THEN
+ 2995                                               SemError(232)
+ 2996                                             ELSE res := SymTab.CurRes();
+ 2997                                               IF NOT hadE THEN
+ 2998                                                 IF res #
+ 2999                                                    SymTab.InvalidType THEN
+ 3000                                                   SemError(232)
+ 3001                                                 END
+ 3002                                               ELSIF (res =
+ 3003                                                      SymTab.InvalidType)
+ 3004                                                  OR (t #
+ 3005                                                      SymTab.InvalidType)
+ 3006   AND NOT SymTab.Assignable(t,
+ 3007                                                       res) THEN
+ 3008                                                 SemError(232)
+ 3009                                             END
+ 3010                                             END; .) .
+ 3011    HaltStat                              (. VAR t: SymTab.TypeIndex;
+ 3012                                               q: QbeGen.QVal;
+ 3013                                               astVal, astNode: AST.Node; .)
+ 3014      = "HALT" (. astVal := AST.NoNode; .)
+ 3015        [ "(" Expr<t, q> (. astVal := astCur; .) ")" ]
+ 3016                                          (. astNode := AST.MakeNode(AST.NkHalt);
+ 3017                                             IF astVal # AST.NoNode THEN
+ 3018                                               AST.SetChild(astNode, 0, astVal)
+ 3019                                             END;
+ 3020                                             astStmt := astNode;
+ 3021                                             .) .
+ 3022    (* Designator: scalar loads, array addresses, and index suffixes.
+ 3023       Each index descends one level (bounds-checked, trap on breach);
+ 3024       nested levels reload the inner descriptor address. q ends as the
+ 3025       value (scalars), the descriptor address (plain arrays), or the
+ 3026       element address (indexed); sfx marks the indexed form. *)
+ 3027    Design<VAR t: SymTab.TypeIndex; VAR k: INTEGER;
+ 3028           VAR q: QbeGen.QVal; VAR qn: SymTab.Name; VAR sfx: BOOLEAN>
+ 3029                                          (. VAR n: SymTab.Name; .)
+ 3030      = GetIdent<n> DesignTail<n, t, k, q, qn, sfx> .
+ 3031    (* The part of Design after the identifier: resolve it and walk the
+ 3032       selectors.  Split out so a statement can decide between a label
+ 3033       (`ident :`) and a designator (`ident := ...`) with one token. *)
+ 3034    DesignTail<VAR n: SymTab.Name; VAR t: SymTab.TypeIndex; VAR k: INTEGER;
+ 3035           VAR q: QbeGen.QVal; VAR qn: SymTab.Name; VAR sfx: BOOLEAN>
+ 3036                                          (. VAR fn, mal: SymTab.Name;
+ 3037                                               cls: INTEGER;
+ 3038                                               ic: SymTab.TypeIndex;
+ 3039                                               curT, it, eT, bt:
+ 3040                                                 SymTab.TypeIndex;
+ 3041                                               iq, ql, qlo, qhi, qe:
+ 3042                                                 QbeGen.QVal;
+ 3043                                               lo, hi: INTEGER;
+ 3044                                               fo: INTEGER;
+ 3045                                               isOpen: BOOLEAN;
+ 3046                                               qb, cv: QbeGen.QVal;
+ 3047                                               r: BOOLEAN;
+ 3048                                                astDes, astSel: AST.Node; .)
+ 3049      =                                   (. methCls := SymTab.InvalidType;
+ 3050                                             QbeGen.CopyOp(n, qn);
+ 3051                                             sfx := FALSE;
+ 3052                                             IF NOT SymTab.Lookup(n) THEN
+ 3053                                               (* a bare method name inside
+ 3054                                                  a CLASS IMPLEMENTATION
+ 3055                                                  is a sibling call on
+ 3056                                                  THIS *)
+ 3057                                               ic := SymTab.CurImplClass();
+ 3058                                               IF (ic #
+ 3059                                                  SymTab.InvalidType)
+ 3060    AND SymTab.MethodExists(ic, n) THEN
+ 3061                                                 sfx := FALSE;
+ 3062                                                  QbeGen.CopyOp("@", q);
+ 3063                                                 methCls := ic;
+ 3064                                                 k := SymTab.KindProc;
+ 3065                                                 t := SymTab.InvalidType
+ 3066                                               ELSIF SymTab.InProc() THEN
+ 3067                                                 (* not declared anywhere
+ 3068                                                    in scope: with bodies
+ 3069                                                    parsed at unit end this
+ 3070                                                    is a genuine 201 (a
+ 3071                                                    nested-local forward is
+ 3072                                                    no longer tolerated). *)
+ 3073                                                 SemError(201);
+ 3074                                                 t := SymTab.InvalidType;
+ 3075                                                 k := -1;
+ 3076                                                 QbeGen.CopyOp("0", q)
+ 3077                                               ELSE
+ 3078                                                 SemError(201);
+ 3079                                                 t :=
+ 3080                                                   SymTab.InvalidType;
+ 3081                                                 k := -1;
+ 3082                                                 QbeGen.CopyOp("0", q)
+ 3083                                               END
+ 3084                                             ELSE
+ 3085                                               t := SymTab.SymType(n);
+ 3086                                               k := SymTab.SymKind(n);
+ 3087                                               IF k = SymTab.KindConst THEN
+ 3088                                                 IF SymTab.Equal(n,
+ 3089                                                    "TRUE") THEN
+ 3090                                                   t := SymTab.BoolType();
+ 3091                                                   QbeGen.CopyOp("1", q)
+ 3092                                                 ELSIF SymTab.Equal(n,
+ 3093                                                    "FALSE") THEN
+ 3094                                                   t := SymTab.BoolType();
+ 3095                                                   QbeGen.CopyOp("0", q)
+ 3096                                                 ELSIF SymTab.Equal(n,
+ 3097                                                    "NIL") THEN
+ 3098                                                   QbeGen.CopyOp("0", q)
+ 3099                                                 ELSE
+ 3100                                                   cls :=
+ 3101                                                     SymTab.ClassOf(t);
+ 3102                                                   IF (t #
+ 3103                                                       SymTab.InvalidType)
+ 3104   AND ((cls = SymTab.ClInt)
+ 3105                                                      OR (cls
+ 3106                                                          = SymTab.ClChar)
+ 3107                                                      OR (cls
+ 3108                                                          = SymTab.ClEnum)
+ 3109                                                      OR (cls
+ 3110                                                          = SymTab.ClReal)
+ 3111                                                      OR (cls
+ 3112                                                          = SymTab.ClLong)
+ 3113                                                      OR (cls
+ 3114                                                          = SymTab.ClNil)
+ 3115                                                      OR (cls = SymTab.ClByte)
+ 3116                                                      OR (cls = SymTab.ClSByte)
+ 3117                                                      OR (cls = SymTab.ClWord16)
+ 3118                                                      OR (cls = SymTab.ClSWord16)
+ 3119                                                       OR (cls = SymTab.ClBool)) THEN
+ 3120                                                     IF cls = SymTab.ClNil THEN
+ 3121                                                       QbeGen.CopyOp("0", q)
+ 3122                                                     ELSIF ((cls
+ 3123                                                         = SymTab.ClInt)
+ 3124                                                       OR (cls
+ 3125                                                         = SymTab.ClChar)
+ 3126                                                       OR (cls
+ 3127                                                         = SymTab.ClEnum)
+ 3128                                                       OR (cls
+ 3129                                                         = SymTab.ClLong)
+ 3130                                                        OR (cls = SymTab.ClByte)
+ 3131                                                        OR (cls = SymTab.ClSByte)
+ 3132                                                        OR (cls = SymTab.ClWord16)
+ 3133                                                        OR (cls = SymTab.ClSWord16)
+ 3134                                                        OR (cls = SymTab.ClBool))
+ 3135    AND SymTab.GetSymVal(n, cv)
+ 3136    AND QbeGen.IsImm(cv) THEN
+ 3137                                                       QbeGen.CopyOp(cv, q)
+ 3138                                                     ELSE
+ 3139                                                       QbeGen.LoadVar(n,
+ 3140                                                         cls = SymTab.ClReal,
+ 3141                                                         q)
+ 3142                                                     END
+ 3143                                                   ELSIF (cls = SymTab.ClArray)
+ 3144                                                      OR (cls = SymTab.ClRecord)
+ 3145                                                      OR (cls = SymTab.ClClass)
+ 3146                                                      OR (cls = SymTab.ClStr)
+ 3147                                                      OR (cls = SymTab.ClUStr)
+ 3148                                                      OR (cls = SymTab.ClSet) THEN
+ 3149                                                     (* aggregate constant:
+ 3150                                                        its value IS the
+ 3151                                                        descriptor address *)
+ 3152                                                     IF SymTab.GetSymVal(n, cv) THEN
+ 3153                                                       QbeGen.CopyOp(cv, q)
+ 3154                                                     ELSE
+ 3155                                                       QbeGen.CopyOp("0", q)
+ 3156                                                     END
+ 3157                                                   ELSE
+ 3158                                                     IF t #
+ 3159                                                        SymTab.InvalidType THEN
+ 3160                                                       SemError(230)
+ 3161                                                     END;
+ 3162                                                     QbeGen.CopyOp("0", q)
+ 3163                                                   END
+ 3164                                                 END
+ 3165                                               ELSIF (k = SymTab.KindVar)
+ 3166                                                  OR (k = SymTab.KindParam) THEN
+ 3167                                                 cls := SymTab.ClassOf(t);
+ 3168                                                 IF (cls # SymTab.ClInt)
+ 3169                                                    AND (cls # SymTab.ClBool)
+ 3170                                                    AND (cls # SymTab.ClChar)
+ 3171                                                    AND (cls # SymTab.ClUChar)
+ 3172                                                    AND (cls # SymTab.ClEnum)
+ 3173                                                    AND (cls # SymTab.ClReal)
+ 3174                                                    AND (cls # SymTab.ClPtr)
+ 3175                                                    AND (cls # SymTab.ClProc)
+ 3176                                                    AND (cls # SymTab.ClLong)
+ 3177                                                    AND (cls # SymTab.ClArray)
+ 3178                                                    AND (cls # SymTab.ClSet)
+ 3179                                                    AND (cls # SymTab.ClRecord)
+ 3180                                                    AND (cls # SymTab.ClUStr)
+ 3181                                                    AND (cls # SymTab.ClByte)
+ 3182                                                    AND (cls # SymTab.ClSByte)
+ 3183                                                    AND (cls # SymTab.ClWord16)
+ 3184                                                    AND (cls # SymTab.ClSWord16)
+ 3185                                                    AND (cls # SymTab.ClClass) THEN
+ 3186                                                   SemError(230);
+ 3187                                                   QbeGen.CopyOp("0", q)
+ 3188                                                 ELSE QbeGen.CopyOp("@", q)
+ 3189                                                 END
+ 3190                                               ELSE QbeGen.CopyOp("0", q);
+ 3191                                                 IF k = SymTab.KindImport THEN
+ 3192                                                   SemError(230)
+ 3193                                                 ELSIF k =
+ 3194                                                    SymTab.KindProc THEN
+ 3195                                                   (* bare procedure name:
+ 3196                                                      a following ArgList
+ 3197                                                      makes it a call;
+ 3198                                                      otherwise Fact
+ 3199                                                      reports 230 *)
+ 3200                                                 ELSE
+ 3201                                                    IF k = SymTab.KindField THEN
+ 3202                                                      IF QbeGen.TopWith(qb) THEN
+ 3203                                                        sfx := TRUE
+ 3204                                                      ELSE SemError(230);
+ 3205                                                        QbeGen.CopyOp("0", q)
+ 3206                                                      END
+ 3207                                                    END
+ 3208                                                 END
+ 3209                                               END
+ 3210                                             END; .)
+ 3211        (. astDes := AST.MakeNode(AST.NkDesignator);
+ 3212           AST.SetChild(astDes, AST.NChild(astDes), AST.MakeLeaf(AST.NkIdent, n)); .)
+ 3213        { "[" Expr<it, iq>
+ 3214                                          (. AST.SetChild(astDes, AST.NChild(astDes),
+ 3215               AST.MakeUn(AST.NkSelector, AST.SelIndex, astCur)); IF t = SymTab.InvalidType THEN
+ 3216                                             ELSIF SymTab.ClassOf(t) #
+ 3217                                                   SymTab.ClArray THEN
+ 3218                                               SemError(217);
+ 3219                                               t := SymTab.InvalidType
+ 3220                                             ELSIF NOT SymTab.IsIntFamily(it)
+ 3221   AND (SymTab.ClassOf(it) #
+ 3222                                                   SymTab.ClChar)
+ 3223   AND (SymTab.ClassOf(it) #
+ 3224                                                   SymTab.ClEnum)
+ 3225   AND (SymTab.ClassOf(it) #
+ 3226                                                   SymTab.ClBool) THEN
+ 3227                                               SemError(218);
+ 3228                                               t := SymTab.InvalidType
+ 3229                                              ELSE
+ 3230                                                eT := SymTab.ArrayElem(t);
+ 3231                                                t := eT; sfx := TRUE
+ 3232                                              END; .)
+ 3233          { "," Expr<it, iq>
+ 3234                                          (. AST.SetChild(astDes, AST.NChild(astDes),
+ 3235               AST.MakeUn(AST.NkSelector, AST.SelIndex, astCur)); IF t = SymTab.InvalidType THEN
+ 3236                                             ELSIF SymTab.ClassOf(t) #
+ 3237                                                   SymTab.ClArray THEN
+ 3238                                               SemError(217);
+ 3239                                               t := SymTab.InvalidType
+ 3240                                             ELSIF NOT SymTab.IsIntFamily(it)
+ 3241   AND (SymTab.ClassOf(it) #
+ 3242                                                   SymTab.ClChar)
+ 3243   AND (SymTab.ClassOf(it) #
+ 3244                                                   SymTab.ClEnum)
+ 3245   AND (SymTab.ClassOf(it) #
+ 3246                                                   SymTab.ClBool) THEN
+ 3247                                               SemError(218);
+ 3248                                               t := SymTab.InvalidType
+ 3249                                              ELSE
+ 3250                                                eT := SymTab.ArrayElem(t);
+ 3251                                                t := eT; sfx := TRUE
+ 3252                                              END; .) }
+ 3253          "]"
+ 3254        | "." GetIdent<fn>
+ 3255                                          (. astSel := AST.MakeNode(AST.NkSelector);
+ 3256               AST.SetOp(astSel, AST.SelField);
+ 3257               AST.SetChild(astSel, 0, AST.MakeLeaf(AST.NkIdent, fn));
+ 3258               AST.SetChild(astDes, AST.NChild(astDes), astSel); IF k = SymTab.KindModule THEN
+ 3259                                               (* qualified L.x: materialize
+ 3260                                                  the export, then load it *)
+ 3261                                               IF NOT SymTab.MaterializeAlias(n,
+ 3262                                                    fn, mal) THEN
+ 3263                                                 SemError(201);
+ 3264                                                 t := SymTab.InvalidType;
+ 3265                                                 QbeGen.CopyOp("0", q)
+ 3266                                               ELSE
+ 3267                                                 QbeGen.CopyOp(mal, qn);
+ 3268                                                 t := SymTab.SymType(mal);
+ 3269                                                 k := SymTab.SymKind(mal);
+ 3270                                                 sfx := FALSE;
+ 3271                                                 IF k = SymTab.KindProc THEN
+ 3272                                                   (* call: ArgList supplies
+ 3273                                                      the value *)
+ 3274                                                   QbeGen.CopyOp("0", q)
+ 3275                                                 ELSIF k = SymTab.KindConst THEN
+ 3276                                                   IF SymTab.GetSymVal(mal,
+ 3277                                                      cv)
+ 3278                                                   THEN QbeGen.CopyOp(cv, q)
+ 3279                                                   ELSE QbeGen.CopyOp("0", q)
+ 3280                                                   END
+ 3281                                                  END
+ 3282                                               END
+ 3283                                             ELSIF t = SymTab.InvalidType THEN
+ 3284                                             ELSIF (SymTab.ClassOf(t) #
+ 3285                                                    SymTab.ClRecord)
+ 3286   AND (SymTab.ClassOf(t) #
+ 3287                                                   SymTab.ClClass) THEN
+ 3288                                               SemError(215);
+ 3289                                               t := SymTab.InvalidType
+ 3290                                             ELSIF (SymTab.ClassOf(t) =
+ 3291                                                    SymTab.ClClass)
+ 3292    AND SymTab.MethodExists(t, fn) THEN
+ 3293                                               (* obj.Method: bind the
+ 3294                                                  method and pass obj as
+ 3295                                                  the hidden receiver; q
+ 3296                                                  already holds the
+ 3297                                                  object's address *)
+ 3298                                               QbeGen.CopyOp(fn, n);
+ 3299                                               QbeGen.CopyOp(fn, qn);
+ 3300                                               methCls := t;
+ 3301                                               k := SymTab.KindProc;
+ 3302                                               t := SymTab.InvalidType
+ 3303                                             ELSIF NOT SymTab.FieldExists(t,
+ 3304                                                      fn) THEN
+ 3305                                               SemError(216);
+ 3306                                               t := SymTab.InvalidType
+ 3307                                              ELSE
+ 3308                                                t := SymTab.FieldType(t, fn);
+ 3309                                                sfx := TRUE
+ 3310                                              END; .)
+ 3311        | "^"
+ 3312                                          (. astSel := AST.MakeNode(AST.NkSelector);
+ 3313               AST.SetOp(astSel, AST.SelDeref);
+ 3314               AST.SetChild(astDes, AST.NChild(astDes), astSel); IF t = SymTab.InvalidType THEN
+ 3315                                             ELSIF SymTab.ClassOf(t) #
+ 3316                                                   SymTab.ClPtr THEN
+ 3317                                               SemError(219);
+ 3318                                               t := SymTab.InvalidType
+ 3319                                             ELSE
+ 3320                                               bt := SymTab.PtrBase(t);
+ 3321                                               IF bt = SymTab.InvalidType THEN
+ 3322                                               ELSE
+ 3323                                                  t := bt;
+ 3324                                                  sfx := TRUE
+ 3325                                                END
+ 3326                                             END; .) } (. astCur := astDes; .) .
+ 3327    (* Result suffix (ISO component after a function call): `F()^`,
+ 3328       `F()[i]`, `F().field`.  The call result is in t/q with sfx FALSE
+ 3329       (a value, or a descriptor address for aggregates); each component
+ 3330       descends one level exactly like the Design components. *)
+ 3331    ResultComp<VAR t: SymTab.TypeIndex; VAR q: QbeGen.QVal;
+ 3332               VAR sfx: BOOLEAN; VAR node: AST.Node;
+ 3333               VAR mname: SymTab.Name; VAR methCls: SymTab.TypeIndex;
+ 3334               VAR isM: BOOLEAN>          (. VAR it, eT, bt: SymTab.TypeIndex;
+ 3335                                               iq, ql, qlo, qhi, qe, qb:
+ 3336                                                 QbeGen.QVal;
+ 3337                                               lo, hi, fo: INTEGER;
+ 3338                                               isOpen: BOOLEAN;
+ 3339                                               fname: SymTab.Name;
+ 3340                                               astWrap, astSel: AST.Node; .)
+ 3341      = "[" Expr<it, iq>
+ 3342                                          (. isM := FALSE;
+ 3343                                             IF AST.Kind(node) # AST.NkDesignator THEN
+ 3344                                               astWrap := AST.MakeNode(
+ 3345                                                 AST.NkDesignator);
+ 3346                                               AST.SetChild(astWrap, 0, node);
+ 3347                                               node := astWrap
+ 3348                                             END;
+ 3349                                             AST.SetChild(node, AST.NChild(node),
+ 3350                                               AST.MakeUn(AST.NkSelector,
+ 3351                                                 AST.SelIndex, astCur)); IF t = SymTab.InvalidType THEN
+ 3352                                             ELSIF SymTab.ClassOf(t) #
+ 3353                                                   SymTab.ClArray THEN
+ 3354                                               SemError(217);
+ 3355                                               t := SymTab.InvalidType
+ 3356                                             ELSIF NOT SymTab.IsIntFamily(it)
+ 3357    AND (SymTab.ClassOf(it) # SymTab.ClChar)
+ 3358    AND (SymTab.ClassOf(it) # SymTab.ClEnum)
+ 3359    AND (SymTab.ClassOf(it) # SymTab.ClBool) THEN
+ 3360                                               SemError(218);
+ 3361                                               t := SymTab.InvalidType
+ 3362                                              ELSE
+ 3363                                                eT := SymTab.ArrayElem(t);
+ 3364                                                t := eT; sfx := TRUE
+ 3365                                              END; .)
+ 3366        "]"
+ 3367      | "." GetIdent<fname>
+ 3368                                          (. isM := FALSE;
+ 3369                                             IF AST.Kind(node) # AST.NkDesignator THEN
+ 3370                                               astWrap := AST.MakeNode(
+ 3371                                                 AST.NkDesignator);
+ 3372                                               AST.SetChild(astWrap, 0, node);
+ 3373                                               node := astWrap
+ 3374                                             END;
+ 3375                                             AST.SetChild(node, AST.NChild(node),
+ 3376                                               AST.MakeUn(AST.NkSelector,
+ 3377                                                 AST.SelField,
+ 3378                                                 AST.MakeLeaf(AST.NkIdent,
+ 3379                                                   fname))); IF t = SymTab.InvalidType THEN
+ 3380                                             ELSIF (SymTab.ClassOf(t) #
+ 3381                                                    SymTab.ClRecord)
+ 3382    AND (SymTab.ClassOf(t) # SymTab.ClClass) THEN
+ 3383                                               SemError(215);
+ 3384                                               t := SymTab.InvalidType
+ 3385                                              ELSIF (SymTab.ClassOf(t) =
+ 3386                                                     SymTab.ClClass)
+ 3387    AND SymTab.MethodExists(t, fname) THEN
+ 3388                                                (* a method on the call result:
+ 3389                                                   a following ArgList makes
+ 3390                                                   the call *)
+ 3391                                                mname := fname;
+ 3392                                                methCls := t; isM := TRUE;
+ 3393                                                t := SymTab.InvalidType
+ 3394                                             ELSIF NOT SymTab.FieldExists(t,
+ 3395                                                      fname) THEN
+ 3396                                               SemError(216);
+ 3397                                               t := SymTab.InvalidType
+ 3398                                              ELSE
+ 3399                                                t := SymTab.FieldType(t, fname);
+ 3400                                                sfx := TRUE
+ 3401                                              END; .)
+ 3402      | "^"                               (. isM := FALSE;
+ 3403                                             IF AST.Kind(node) # AST.NkDesignator THEN
+ 3404                                               astWrap := AST.MakeNode(
+ 3405                                                 AST.NkDesignator);
+ 3406                                               AST.SetChild(astWrap, 0, node);
+ 3407                                               node := astWrap
+ 3408                                             END;
+ 3409                                             astSel := AST.MakeNode(AST.NkSelector);
+ 3410                                             AST.SetOp(astSel, AST.SelDeref);
+ 3411                                             AST.SetChild(node,
+ 3412                                               AST.NChild(node), astSel); IF t = SymTab.InvalidType THEN
+ 3413                                             ELSIF SymTab.ClassOf(t) #
+ 3414                                                   SymTab.ClPtr THEN
+ 3415                                               SemError(219);
+ 3416                                               t := SymTab.InvalidType
+ 3417                                             ELSE
+ 3418                                               bt := SymTab.PtrBase(t);
+ 3419                                               IF bt # SymTab.InvalidType THEN
+ 3420                                                  t := bt; sfx := TRUE
+ 3421                                               END
+ 3422                                             END; .) .
+ 3423    Expr<VAR t: SymTab.TypeIndex; VAR q: QbeGen.QVal>
+ 3424                                          (. VAR t2: SymTab.TypeIndex;
+ 3425                                               op: INTEGER;
+ 3426                                               q2, qt, wl: QbeGen.QVal;
+ 3427                                                astA, astB: AST.Node;
+ 3428                                                astOp: INTEGER;
+ 3429                                                astMade: BOOLEAN;
+ 3430                                               isR: BOOLEAN;
+ 3431                                               v1, v2: INTEGER;
+ 3432                                               b: BOOLEAN; .)
+ 3433      = SimExpr<t, q>                     (. astA := astCur; astMade := FALSE; .)
+ 3434        [ Rel<op> SimExpr<t2, q2>
+ 3435          (. astB := astCur; astMade := TRUE;
+ 3436              astOp := AST.OpEq;
+ 3437              IF op = SymTab.OpNeq1 THEN astOp := AST.OpNe
+ 3438              ELSIF op = SymTab.OpNeq2 THEN astOp := AST.OpNe
+ 3439              ELSIF op = SymTab.OpLt THEN astOp := AST.OpLt
+ 3440              ELSIF op = SymTab.OpLe THEN astOp := AST.OpLe
+ 3441              ELSIF op = SymTab.OpGt THEN astOp := AST.OpGt
+ 3442              ELSIF op = SymTab.OpGe THEN astOp := AST.OpGe
+ 3443              ELSIF op = SymTab.OpIn THEN astOp := AST.OpIn
+ 3444              END;
+ 3445              IF op = SymTab.OpIn THEN
+ 3446               IF SymTab.InCheck(t, t2) THEN
+ 3447                 IF (t = SymTab.InvalidType)
+ 3448                    OR (t2 = SymTab.InvalidType) THEN
+ 3449                   t := SymTab.BoolType(); QbeGen.CopyOp("0", q)
+ 3450                 ELSE
+ 3451                    t := SymTab.BoolType(); QbeGen.CopyOp("@", q)
+ 3452                 END
+ 3453               ELSE SemError(222); t := SymTab.InvalidType;
+ 3454                 QbeGen.CopyOp("0", q)
+ 3455               END
+ 3456             ELSIF SymTab.RelCheck(t, t2, op) THEN
+ 3457               IF (t = SymTab.InvalidType)
+ 3458                  OR (t2 = SymTab.InvalidType) THEN
+ 3459                 t := SymTab.BoolType(); QbeGen.CopyOp("0", q)
+ 3460               ELSIF SymTab.IsOrdinal(t) AND SymTab.IsOrdinal(t2)
+ 3461                  AND QbeGen.IsImm(q) AND QbeGen.IsImm(q2)
+ 3462                  AND SymTab.ConstInt(q, v1)
+ 3463                  AND SymTab.ConstInt(q2, v2) THEN
+ 3464                 (* fold a relation of two ordinal constants (needed for
+ 3465                    ORD(boolean) in a CONST initialiser) *)
+ 3466                 IF op = SymTab.OpEq THEN b := v1 = v2
+ 3467                 ELSIF (op = SymTab.OpNeq1) OR (op = SymTab.OpNeq2) THEN
+ 3468                   b := v1 # v2
+ 3469                 ELSIF op = SymTab.OpLt THEN b := v1 < v2
+ 3470                 ELSIF op = SymTab.OpLe THEN b := v1 <= v2
+ 3471                 ELSIF op = SymTab.OpGt THEN b := v1 > v2
+ 3472                 ELSE b := v1 >= v2
+ 3473                 END;
+ 3474                 t := SymTab.BoolType();
+ 3475                 IF b THEN QbeGen.CopyOp("1", q)
+ 3476                 ELSE QbeGen.CopyOp("0", q)
+ 3477                 END
+ 3478               ELSIF (SymTab.ClassOf(t) = SymTab.ClPtr)
+ 3479                  OR (SymTab.ClassOf(t2) = SymTab.ClPtr) THEN
+ 3480                 IF (op # SymTab.OpEq) AND (op # SymTab.OpNeq1)
+ 3481   AND (op # SymTab.OpNeq2) THEN
+ 3482                   SemError(213); t := SymTab.InvalidType;
+ 3483                   QbeGen.CopyOp("0", q)
+ 3484                  ELSE
+ 3485                    t := SymTab.BoolType(); QbeGen.CopyOp("@", q)
+ 3486                  END
+ 3487                ELSIF (SymTab.ClassOf(t) = SymTab.ClSet)
+ 3488                   OR (SymTab.ClassOf(t2) = SymTab.ClSet) THEN
+ 3489                  t := SymTab.BoolType(); QbeGen.CopyOp("@", q)
+ 3490               ELSIF SymTab.StrCompat(t, t2) THEN
+ 3491                 QbeGen.StrEq(op, q, q2, qt);
+ 3492                 t := SymTab.BoolType(); QbeGen.CopyOp(qt, q)
+ 3493               ELSIF SymTab.IsLongFamily(t)
+ 3494                  OR SymTab.IsLongFamily(t2) THEN
+ 3495                  t := SymTab.BoolType(); QbeGen.CopyOp("@", q)
+ 3496                ELSE
+ 3497                  t := SymTab.BoolType();
+ 3498                  QbeGen.CopyOp("@", q)
+ 3499                END
+ 3500             ELSE SemError(213); t := SymTab.InvalidType;
+ 3501                QbeGen.CopyOp("0", q)
+ 3502              END;
+ 3503              astCur := AST.MakeBin(AST.NkBinExpr, astOp, astA, astB); .) ]
+ 3504         (. IF NOT astMade THEN astCur := astA END; .)
+ 3505             (. IF astCur # AST.NoNode THEN AST.SetTy(astCur, t) END; .) .
+ 3506    Rel<VAR op: INTEGER>
+ 3507      = "="                               (. op := SymTab.OpEq; .)
+ 3508      | "#"                               (. op := SymTab.OpNeq1; .)
+ 3509      | "<"                               (. op := SymTab.OpLt; .)
+ 3510      | "<="                              (. op := SymTab.OpLe; .)
+ 3511      | ">"                               (. op := SymTab.OpGt; .)
+ 3512      | ">="                              (. op := SymTab.OpGe; .)
+ 3513      | "IN"                              (. op := SymTab.OpIn; .) .
+ 3514    SimExpr<VAR t: SymTab.TypeIndex; VAR q: QbeGen.QVal>
+ 3515                                          (. VAR t2, res2, lt, rt:
+ 3516                                                 SymTab.TypeIndex;
+ 3517                                               op: INTEGER;
+ 3518                                               q2, qt, wq, qf, q2a, q2b:
+ 3519                                                 QbeGen.QVal;
+ 3520                                               neg, isR, isL, folded:
+ 3521                                                 BOOLEAN;
+ 3522                                               fok: BOOLEAN;
+ 3523                                               lw, rw, mw: CARDINAL;
+ 3524                                               lTrue, lNext, lDone, qr, qs: QbeGen.QVal;
+ 3525                                                astA, astB: AST.Node;
+ 3526                                                astSign, astOp: INTEGER;
+ 3527                                                v1, v2: INTEGER;
+ 3528                                                s: ARRAY [0 .. 255] OF CHAR; .)
+ 3529      =                                   (. neg := FALSE; astSign := 0; .)
+ 3530        [ "+"                         (. neg := TRUE; astSign := 1; .)
+ 3531        | "-"                         (. neg := TRUE; astSign := -1; .) ]
+ 3532        Term<t, q> (. astA := astCur;
+ 3533                                            IF neg AND QbeGen.IsImm(q) THEN
+ 3534                                              QbeGen.NegFold(q, q)
+ 3535                                            END;
+ 3536                                           IF astSign < 0 THEN
+ 3537                                             astCur := AST.MakeUn(
+ 3538                                               AST.NkUnary, AST.OpSub, astA);
+ 3539                                             astA := astCur
+ 3540                                           END; .)
+ 3541         { AddOp<op>
+ 3542           Term<t2, q2> (. astB := astCur; .)
+ 3543          (. astOp := AST.OpAdd;
+ 3544             IF op = SymTab.OpSub THEN astOp := AST.OpSub
+ 3545             ELSIF op = SymTab.OpOr THEN astOp := AST.OpOr END;
+ 3546             astA := AST.MakeBin(AST.NkBinExpr, astOp, astA, astB);
+ 3547             astCur := astA;
+ 3548             IF op = SymTab.OpOr THEN
+ 3549               (* short-circuit: if q is true the RHS is skipped *)
+ 3550               IF SymTab.BoolCheck(t) AND SymTab.BoolCheck(t2) THEN
+ 3551                 t := SymTab.BoolType()
+ 3552               ELSE SemError(212); t := SymTab.InvalidType END;
+ 3553                IF t # SymTab.InvalidType THEN
+ 3554                  QbeGen.CopyOp("@", q)
+ 3555                ELSE QbeGen.CopyOp("0", q)
+ 3556                END
+ 3557             ELSIF (op = SymTab.OpAdd)
+ 3558               AND (SymTab.ClassOf(t) = SymTab.ClChar)
+ 3559               AND (SymTab.ClassOf(t2) = SymTab.ClChar)
+ 3560               AND QbeGen.IsImm(q) AND QbeGen.IsImm(q2) THEN
+ 3561               (* "W" + "o": two one-character string literals concatenate
+ 3562                  to a two-character string (they are CHAR-typed immediates) *)
+ 3563               IF SymTab.ConstInt(q, v1) AND SymTab.ConstInt(q2, v2)
+ 3564                  AND (v1 >= 0) AND (v1 <= 255)
+ 3565                  AND (v2 >= 0) AND (v2 <= 255) THEN
+ 3566                 s[0] := '"'; s[1] := CHR(v1); s[2] := CHR(v2);
+ 3567                 s[3] := '"'; s[4] := CHR(0);
+ 3568                 QbeGen.DeclStr(s, qt); QbeGen.CopyOp(qt, q);
+ 3569                 t := SymTab.NewStr();
+ 3570                 astA := AST.MakeLeaf(AST.NkStrLit, s);
+ 3571                 astCur := astA
+ 3572               ELSE SemError(211); t := SymTab.InvalidType;
+ 3573                 QbeGen.CopyOp("0", q)
+ 3574               END
+ 3575             ELSIF (op = SymTab.OpAdd)
+ 3576               AND (SymTab.UStrCompat(t, t2)
+ 3577                 OR ((SymTab.ClassOf(t) = SymTab.ClUChar)
+ 3578                   AND (SymTab.ClassOf(t2) = SymTab.ClUStr))
+ 3579                 OR ((SymTab.ClassOf(t) = SymTab.ClUStr)
+ 3580                   AND (SymTab.ClassOf(t2) = SymTab.ClUChar))
+ 3581                 OR ((SymTab.ClassOf(t) = SymTab.ClUChar)
+ 3582                   AND (SymTab.ClassOf(t2) = SymTab.ClUChar))) THEN
+ 3583               (* UString concatenation: a UCHAR operand becomes a
+ 3584                  1-codepoint UString; the result is a descriptor in the
+ 3585                  shim's concat buffer.  Work on copies so neither
+ 3586                  operand is clobbered. *)
+ 3587                t := SymTab.NewUStr();
+ 3588                QbeGen.CopyOp("@", q)
+ 3589             ELSIF (op = SymTab.OpAdd)
+ 3590               AND (SymTab.StrCompat(t, t2)
+ 3591                 OR (SymTab.IsStrType(t)
+ 3592                   AND (SymTab.ClassOf(t2) = SymTab.ClChar))
+ 3593                 OR ((SymTab.ClassOf(t) = SymTab.ClChar)
+ 3594                   AND SymTab.IsStrType(t2))) THEN
+ 3595               (* string concatenation; a CHAR operand becomes a
+ 3596                  1-character string literal.  When both operands are
+ 3597                  constants, fold to a single string literal so a
+ 3598                  constructor element stays compile-time. *)
+ 3599                QbeGen.StrFold(q, q2, SymTab.ClassOf(t), SymTab.ClassOf(t2),
+ 3600                  qt, fok);
+ 3601                IF fok THEN QbeGen.CopyOp(qt, q)
+ 3602                ELSE QbeGen.CopyOp("@", q)
+ 3603                END;
+ 3604                t := SymTab.NewStr()
+ 3605             ELSIF (t # SymTab.InvalidType) AND (t2 # SymTab.InvalidType)
+ 3606   AND (SymTab.ClassOf(t) = SymTab.ClSet)
+ 3607   AND (SymTab.ClassOf(t2) = SymTab.ClSet) THEN
+ 3608                lw := SymTab.SetWords(t); rw := SymTab.SetWords(t2);
+ 3609                mw := lw;
+ 3610                IF rw > mw THEN mw := rw END;
+ 3611                t := SymTab.NewSet(
+ 3612                       SymTab.NewSubR(0,
+ 3613                         VAL(INTEGER, mw) * 32 - 1));
+ 3614                QbeGen.CopyOp("@", q)
+ 3615             ELSE
+ 3616               IF SymTab.ArithCheck(t, t2, FALSE, res2) THEN
+ 3617                 lt := t; rt := t2; t := res2
+ 3618               ELSE SemError(211); t := SymTab.InvalidType END;
+ 3619               IF t # SymTab.InvalidType THEN
+ 3620                 isL := SymTab.IsLongFamily(t);
+ 3621                 isR := SymTab.ClassOf(t) = SymTab.ClReal;
+ 3622                 folded := FALSE;
+ 3623                 IF (NOT isL) AND (NOT isR)
+ 3624    AND QbeGen.IsImm(q) AND QbeGen.IsImm(q2) THEN
+ 3625                   IF op = SymTab.OpAdd THEN
+ 3626                     folded := QbeGen.Fold2(0, q, q2, qf)
+ 3627                   ELSE
+ 3628                     folded := QbeGen.Fold2(1, q, q2, qf)
+ 3629                   END
+ 3630                 END;
+ 3631                 IF folded THEN QbeGen.CopyOp(qf, q)
+ 3632                  ELSE
+ 3633                  QbeGen.CopyOp("@", q)
+ 3634                  END
+ 3635               ELSE QbeGen.CopyOp("0", q)
+ 3636               END
+ 3637             END; .) }
+ 3638             (. IF astCur # AST.NoNode THEN AST.SetTy(astCur, t) END; .) .
+ 3639    AddOp<VAR op: INTEGER>
+ 3640      = "+"                               (. op := SymTab.OpAdd; .)
+ 3641      | "-"                               (. op := SymTab.OpSub; .)
+ 3642      | "OR"                              (. op := SymTab.OpOr; .) .
+ 3643    Term<VAR t: SymTab.TypeIndex; VAR q: QbeGen.QVal>
+ 3644                                          (. VAR t2, res2, lt, rt:
+ 3645                                                 SymTab.TypeIndex;
+ 3646                                               op: INTEGER;
+ 3647                                               q2, qt, wq, qf:
+ 3648                                                 QbeGen.QVal;
+ 3649                                               isR, isL, folded: BOOLEAN;
+ 3650                                               lw, rw, mw: CARDINAL;
+ 3651                                               lNext, lFalse, lDone, qr, qs: QbeGen.QVal;
+ 3652                                                astA, astB: AST.Node;
+ 3653                                                astOp: INTEGER; .)
+ 3654      = Fact<t, q> (. astA := astCur; .) { MulOp<op>
+ 3655          Fact<t2, q2> (. astB := astCur; .)
+ 3656        (. astOp := AST.OpMul;
+ 3657           IF op = SymTab.OpSlash THEN astOp := AST.OpDiv
+ 3658           ELSIF op = SymTab.OpDiv THEN astOp := AST.OpDiv
+ 3659           ELSIF op = SymTab.OpMod THEN astOp := AST.OpMod
+ 3660           ELSIF op = SymTab.OpAnd THEN astOp := AST.OpAnd END;
+ 3661           astA := AST.MakeBin(AST.NkBinExpr, astOp, astA, astB);
+ 3662           astCur := astA;
+ 3663           IF op = SymTab.OpAnd THEN
+ 3664             (* short-circuit: if q is false the RHS is skipped *)
+ 3665             IF SymTab.BoolCheck(t) AND SymTab.BoolCheck(t2) THEN
+ 3666               t := SymTab.BoolType()
+ 3667             ELSE SemError(212); t := SymTab.InvalidType END;
+ 3668              IF t # SymTab.InvalidType THEN QbeGen.CopyOp("@", q)
+ 3669              ELSE QbeGen.CopyOp("0", q)
+ 3670              END
+ 3671           ELSIF (t # SymTab.InvalidType) AND (t2 # SymTab.InvalidType)
+ 3672   AND (SymTab.ClassOf(t) = SymTab.ClSet)
+ 3673   AND (SymTab.ClassOf(t2) = SymTab.ClSet) THEN
+ 3674              lw := SymTab.SetWords(t); rw := SymTab.SetWords(t2);
+ 3675              mw := lw;
+ 3676              IF rw > mw THEN mw := rw END;
+ 3677              t := SymTab.NewSet(
+ 3678                     SymTab.NewSubR(0,
+ 3679                       VAL(INTEGER, mw) * 32 - 1));
+ 3680              QbeGen.CopyOp("@", q)
+ 3681           ELSE
+ 3682             IF SymTab.ArithCheck(t, t2,
+ 3683                  (op = SymTab.OpDiv) OR (op = SymTab.OpMod),
+ 3684                  res2) THEN
+ 3685               lt := t; rt := t2; t := res2
+ 3686             ELSE SemError(211); t := SymTab.InvalidType END;
+ 3687             IF t # SymTab.InvalidType THEN
+ 3688               isL := SymTab.IsLongFamily(t);
+ 3689               isR := SymTab.ClassOf(t) = SymTab.ClReal;
+ 3690               folded := FALSE;
+ 3691               IF (NOT isL) AND (NOT isR)
+ 3692    AND QbeGen.IsImm(q) AND QbeGen.IsImm(q2) THEN
+ 3693                 IF op = SymTab.OpTimes THEN
+ 3694                   folded := QbeGen.Fold2(2, q, q2, qf)
+ 3695                 ELSIF op = SymTab.OpDiv THEN
+ 3696                   folded := QbeGen.Fold2(3, q, q2, qf)
+ 3697                 ELSIF op = SymTab.OpMod THEN
+ 3698                   folded := QbeGen.Fold2(4, q, q2, qf)
+ 3699                 END
+ 3700               END;
+ 3701               IF folded THEN QbeGen.CopyOp(qf, q)
+ 3702                ELSE
+ 3703                QbeGen.CopyOp("@", q)
+ 3704                END
+ 3705             ELSE QbeGen.CopyOp("0", q)
+ 3706             END
+ 3707           END; .) }
+ 3708             (. IF astCur # AST.NoNode THEN AST.SetTy(astCur, t) END; .) .
+ 3709    MulOp<VAR op: INTEGER>
+ 3710      = "*"                               (. op := SymTab.OpTimes; .)
+ 3711      | "/"                               (. op := SymTab.OpSlash; .)
+ 3712      | "DIV"                             (. op := SymTab.OpDiv; .)
+ 3713      | "MOD"                             (. op := SymTab.OpMod; .)
+ 3714      | ( "AND" | "&" )                   (. op := SymTab.OpAnd; .) .
+ 3715    Fact<VAR t: SymTab.TypeIndex; VAR q: QbeGen.QVal>
+ 3716                                          (. VAR s: ARRAY [0 .. 255] OF CHAR;
+ 3717                                               et, dt, t2, st, ct2, et2:
+ 3718                                                 SymTab.TypeIndex;
+ 3719                                               dk: INTEGER;
+ 3720                                               qd, q2, sq, qa, qm0, qr, qt:
+ 3721                                                 QbeGen.QVal;
+ 3722                                               qn, vn: SymTab.Name;
+ 3723                                               vt: SymTab.TypeIndex;
+ 3724                                               c1, c2: INTEGER;
+ 3725                                               lo, hi: INTEGER;
+ 3726                                               isMax: BOOLEAN;
+ 3727                                               called, isHigh, sfx, isCh,
+ 3728                                               isU, uok, isStr: BOOLEAN;
+ 3729                                               ucp: INTEGER; astIsLit: BOOLEAN;
+ 3730                                                astD: AST.Node;
+ 3731                                                astCall: BOOLEAN;
+ 3732                                                astNode, astNot: AST.Node;
+ 3733                                                j: CARDINAL;
+ 3734                                                astArg2: AST.Node;
+ 3735                                                astBrace: AST.Node;
+ 3736                                                astRes: AST.Node; mname: SymTab.Name; isM: BOOLEAN;
+ 3737                                                isConvF: BOOLEAN;
+ 3738                                                fi, fj: CARDINAL; .)
+ 3739      = (. astIsLit := FALSE; .)
+ 3740      ( "__LINE__"                        (. QbeGen.IntStr(M2S.line, q);
+ 3741                                             astIsLit := TRUE;
+ 3742                                             astCur := AST.MakeLeaf(
+ 3743                                               AST.NkIntLit, q);
+ 3744                                             t := SymTab.IntType(); .)
+ 3745      | "__FUNCTION__"                    (. (* fold to the current procedure
+ 3746                                                (module name at unit level) *)
+ 3747                                             s[0] := '"'; fi := 1; fj := 0;
+ 3748                                             IF curFun[0] = CHR(0) THEN
+ 3749                                               WHILE (unitName[fj] # CHR(0))
+ 3750                                                 AND (fi < HIGH(s)) DO
+ 3751                                                 s[fi] := unitName[fj];
+ 3752                                                 INC(fi); INC(fj)
+ 3753                                               END
+ 3754                                             ELSE
+ 3755                                               WHILE (curFun[fj] # CHR(0))
+ 3756                                                 AND (fi < HIGH(s)) DO
+ 3757                                                 s[fi] := curFun[fj];
+ 3758                                                 INC(fi); INC(fj)
+ 3759                                               END
+ 3760                                             END;
+ 3761                                             s[fi] := '"';
+ 3762                                             s[fi + 1] := CHR(0);
+ 3763                                             astIsLit := TRUE;
+ 3764                                             astCur := AST.MakeLeaf(
+ 3765                                               AST.NkStrLit, s);
+ 3766                                             t := SymTab.NewStr();
+ 3767                                             QbeGen.DeclStr(s, q); .)
+ 3768      | "__FILE__"                        (. (* fold to the quoted file name *)
+ 3769                                             s[0] := '"'; fi := 1; fj := 0;
+ 3770                                             WHILE (M2S.fileName[fj] # CHR(0))
+ 3771                                               AND (fi < HIGH(s)) DO
+ 3772                                               s[fi] := M2S.fileName[fj];
+ 3773                                               INC(fi); INC(fj)
+ 3774                                             END;
+ 3775                                             s[fi] := '"';
+ 3776                                             s[fi + 1] := CHR(0);
+ 3777                                             astIsLit := TRUE;
+ 3778                                             astCur := AST.MakeLeaf(
+ 3779                                               AST.NkStrLit, s);
+ 3780                                             t := SymTab.NewStr();
+ 3781                                             QbeGen.DeclStr(s, q); .)
+ 3782      | integer                           (. LexString(s);
+ 3783                                             QbeGen.NormInt(s, q); astIsLit := TRUE; astCur := AST.MakeLeaf(AST.NkIntLit, s);
+ 3784                                             t := SymTab.IntType(); .)
+ 3785      | charConst                         (. LexString(s);
+ 3786                                             QbeGen.NormLit(s, q, isCh);
+ 3787                                             astIsLit := TRUE;
+ 3788                                             astCur := AST.MakeLeaf(
+ 3789                                               AST.NkCharLit, s);
+ 3790                                             t := SymTab.CharType(); .)
+ 3791      | real                              (. LexString(s);
+ 3792                                             QbeGen.NormReal(s, q);
+ 3793                                             astIsLit := TRUE;
+ 3794                                             astCur := AST.MakeLeaf(
+ 3795                                               AST.NkRealLit, s);
+ 3796                                             t := SymTab.RealType(); .)
+ 3797      | string                            (. LexString(s);
+ 3798                                             astIsLit := TRUE;
+ 3799                                             astCur := AST.MakeLeaf(
+ 3800                                               AST.NkStrLit, s);
+ 3801                                             IF SymTab.StrLen(s) = 3 THEN
+ 3802                                               t := SymTab.CharType();
+ 3803                                               QbeGen.IntStr(
+ 3804                                                 QbeGen.CharVal(s), q)
+ 3805                                             ELSIF SymTab.StrLen(s) = 2 THEN
+ 3806                                               (* empty string: a string value
+ 3807                                                  for arrays, 0 for CHAR *)
+ 3808                                               t := SymTab.NewEmptyStr();
+ 3809                                               QbeGen.DeclStr(s, q)
+ 3810                                             ELSE t := SymTab.NewStr();
+ 3811                                               QbeGen.DeclStr(s, q);
+ 3812                                               (* a literal's value IS its
+ 3813                                                  static descriptor address *)
+ 3814                                             END; .)
+ 3815      | ustring                           (. LexString(s);
+ 3816                                             astIsLit := TRUE;
+ 3817                                             astCur := AST.MakeLeaf(
+ 3818                                               AST.NkStrLit, s);
+ 3819                                             QbeGen.DeclUStr(s, q, isU, ucp,
+ 3820                                               uok);
+ 3821                                             IF NOT uok THEN
+ 3822                                               SemError(234);
+ 3823                                               t := SymTab.InvalidType
+ 3824                                             ELSIF isU THEN
+ 3825                                               t := SymTab.UCharType();
+ 3826                                               QbeGen.IntStr(ucp, q)
+ 3827                                             ELSE
+ 3828                                               t := SymTab.NewUStr();
+ 3829                                             END; .)
+ 3830      | Design<dt, dk, qd, qn, sfx>       (. astD := astCur; astCall := FALSE; astBrace := AST.NoNode;
+ 3831                                             astNArgs := 0; called := FALSE;
+ 3832                                             t := dt;
+ 3833                                             IF dk = SymTab.KindConst THEN
+ 3834                                               QbeGen.CopyOp(qd, q)
+ 3835                                             ELSE QbeGen.CopyOp("@", q)
+ 3836                                             END; .)
+ 3837        [ TypedBraceLit<dt, q>            (. t := dt; astCall := TRUE;
+ 3838                                               astBrace := astCur; .) ]
+ 3839        [ ArgList<qn, dt, qd, TRUE, FALSE, methCls, ct2, q2, called>
+ 3840                                          (. astCall := TRUE;
+ 3841                                             IF (SymTab.SymKind(qn) = SymTab.KindType)
+ 3842    OR (SymTab.SymKind(qn) = SymTab.KindPredef) THEN
+ 3843                                             (* T(x): emit as the VAL builtin so Lower's
+ 3844                                                conversion rules apply unchanged *)
+ 3845                                             astNode := AST.MakeNode(AST.NkCall);
+ 3846                                             AST.SetChild(astNode, 0,
+ 3847                                               AST.MakeLeaf(AST.NkIdent, "VAL"));
+ 3848                                             AST.SetChild(astNode, 1,
+ 3849                                               AST.MakeLeaf(AST.NkIdent, qn));
+ 3850                                             IF astNArgs = 1 THEN
+ 3851                                               AST.SetChild(astNode, 2, astArgs[0])
+ 3852                                             END;
+ 3853                                             isConvF := TRUE
+ 3854                                             ELSE astNode := AstCallNode(astD)
+ 3855                                             END;
+ 3856                                             astRes := astNode;
+ 3857                                             t := ct2;
+ 3858                                             QbeGen.CopyOp(q2, q);
+ 3859                                             IF isConvF AND QbeGen.IsImm(convQ)
+ 3860                                                AND OrdClass(convT) AND OrdClass(ct2) THEN
+ 3861                                               QbeGen.CopyOp(convQ, q)
+ 3862                                             END;
+ 3863                                             sfx := FALSE; .)
+ 3864          { ResultComp<t, q, sfx, astRes, mname, methCls, isM>
+ 3865            [ (. astNArgs := 0; .)
+ 3866              ArgList<mname, t, q, TRUE, FALSE, methCls, ct2, q2, called>
+ 3867                                          (. astNode := AstCallNode(astRes);
+ 3868                                             astRes := astNode;
+ 3869                                             t := ct2;
+ 3870                                             QbeGen.CopyOp(q2, q);
+ 3871                                             sfx := FALSE; .) ] }
+ 3872                                          (. IF sfx THEN
+ 3873                                               IF t = SymTab.InvalidType THEN
+ 3874                                                 QbeGen.CopyOp("0", q)
+ 3875                                               ELSIF (SymTab.ClassOf(t) #
+ 3876                                                      SymTab.ClRecord)
+ 3877    AND (SymTab.ClassOf(t) # SymTab.ClSet)
+ 3878    AND (SymTab.ClassOf(t) # SymTab.ClArray)
+ 3879    AND (SymTab.ClassOf(t) # SymTab.ClClass) THEN
+ 3880                                                  QbeGen.CopyOp("@", q)
+ 3881                                               END
+ 3882                                             END; .) ]
+ 3883                                          (. IF called THEN
+ 3884                                               astCur := astRes
+ 3885                                             ELSIF astCall THEN
+ 3886                                               astCur := astBrace
+ 3887                                             ELSE astCur := astD
+ 3888                                             END;
+ 3889                                              astIsLit := TRUE;
+ 3890                                              IF NOT called
+ 3891   AND (dk = SymTab.KindProc) THEN
+ 3892                                               (* bare zero-arg function
+ 3893                                                  call (parentheses may be
+ 3894                                                  omitted); a proper or
+ 3895                                                  parameterised proc here
+ 3896                                                  is 230 *)
+ 3897                                                IF (SymTab.ProcNPar(qn) = 0)
+ 3898   AND (SymTab.ProcRes(qn) # SymTab.InvalidType) THEN
+ 3899                                                  t := SymTab.ProcRes(qn);
+ 3900                                                  QbeGen.CopyOp("@", q);
+ 3901                                                  astCur := AST.MakeNode(AST.NkCall);
+ 3902                                                  AST.SetChild(astCur, 0, astD)
+ 3903                                                ELSE
+ 3904                                                  t := SymTab.ProcTypeOf(qn);
+ 3905                                                  QbeGen.CopyOp("@", q)
+ 3906                                                END
+ 3907                                             END; .)
+ 3908      | ( "HIGH"                          (. isHigh := TRUE; .)
+ 3909        | ( "LEN" | "LENGTH" )            (. isHigh := FALSE; .) )
+ 3910        "(" ( Design<dt, dk, qd, qn, sfx> (. isStr := FALSE;
+ 3911                                              isU := FALSE; .)
+ 3912            | string                       (. LexString(s); astCur := AST.MakeLeaf(AST.NkStrLit, s);
+ 3913                                              isStr := TRUE;
+ 3914                                              isU := FALSE;
+ 3915                                              IF SymTab.StrLen(s) = 3 THEN
+ 3916                                                dt := SymTab.CharType();
+ 3917                                                QbeGen.IntStr(QbeGen.CharVal(s),
+ 3918                                                  qd)
+ 3919                                              ELSE
+ 3920                                                dt := SymTab.NewStr();
+ 3921                                                QbeGen.DeclStr(s, qd);
+ 3922                                              END;
+ 3923                                              dk := -1;
+ 3924                                              qn[0] := CHR(0); .)
+ 3925            | ustring                      (. LexString(s); astCur := AST.MakeLeaf(AST.NkStrLit, s);
+ 3926                                              QbeGen.DeclUStr(s, qd, isU, ucp,
+ 3927                                                uok);
+ 3928                                              isStr := FALSE;
+ 3929                                              IF NOT uok THEN
+ 3930                                                SemError(234);
+ 3931                                                dt := SymTab.InvalidType
+ 3932                                              ELSIF isU THEN
+ 3933                                                (* one codepoint: a UCHAR;
+ 3934                                                   LEN is 1, HIGH is 0 *)
+ 3935                                                dt := SymTab.UCharType();
+ 3936                                                QbeGen.IntStr(ucp, qd)
+ 3937                                              ELSE
+ 3938                                                dt := SymTab.NewUStr();
+ 3939                                              END;
+ 3940                                              dk := -1;
+ 3941                                              qn[0] := CHR(0); .) )
+ 3942        ")"
+ 3943                                          (. astNode := AST.MakeNode(AST.NkCall);
+ 3944     IF isHigh THEN AST.SetChild(astNode, 0,
+ 3945       AST.MakeLeaf(AST.NkIdent, "HIGH"))
+ 3946     ELSE AST.SetChild(astNode, 0,
+ 3947       AST.MakeLeaf(AST.NkIdent, "LEN")) END;
+ 3948     IF astCur # AST.NoNode THEN AST.SetChild(astNode, 1, astCur) END;
+ 3949     astCur := astNode; astIsLit := TRUE;
+ 3950                                             IF (dt # SymTab.InvalidType)
+ 3951    AND (SymTab.ClassOf(dt) = SymTab.ClUStr) THEN
+ 3952                                               (* UString: the count is
+ 3953                                                  the descriptor header *)
+ 3954                                                t := SymTab.IntType();
+ 3955                                                QbeGen.CopyOp("@", q)
+ 3956                                             ELSIF (dt # SymTab.InvalidType)
+ 3957    AND (SymTab.ClassOf(dt) = SymTab.ClUChar) THEN
+ 3958                                               (* single UCHAR codepoint *)
+ 3959                                               IF isHigh THEN
+ 3960                                                 QbeGen.CopyOp("0", qr)
+ 3961                                               ELSE
+ 3962                                                 QbeGen.CopyOp("1", qr)
+ 3963                                               END;
+ 3964                                               t := SymTab.IntType();
+ 3965                                               QbeGen.CopyOp(qr, q)
+ 3966                                             ELSIF isStr THEN
+ 3967                                               (* fold: content length at
+ 3968                                                  compile time *)
+ 3969                                               IF SymTab.StrLen(s) = 3 THEN
+ 3970                                                 c1 := 1
+ 3971                                               ELSE
+ 3972                                                 c1 :=
+ 3973                                                   SymTab.StrLen(s) - 2
+ 3974                                               END;
+ 3975                                               IF isHigh THEN
+ 3976                                                 DEC(c1)
+ 3977                                               END;
+ 3978                                               QbeGen.IntStr(c1, qr);
+ 3979                                               t := SymTab.IntType();
+ 3980                                               QbeGen.CopyOp(qr, q)
+ 3981                                             ELSIF dt = SymTab.InvalidType THEN
+ 3982                                               t := SymTab.InvalidType;
+ 3983                                               QbeGen.CopyOp("0", q)
+ 3984                                             ELSIF SymTab.ClassOf(dt) =
+ 3985                                                   SymTab.ClStr THEN
+ 3986                                               (* HIGH/LEN of a string
+ 3987                                                  CONST: its pooled literal
+ 3988                                                  knows its length *)
+ 3989                                               IF QbeGen.StrLitLen(qd, c1) THEN
+ 3990                                                 IF isHigh THEN DEC(c1) END;
+ 3991                                                 QbeGen.IntStr(VAL(INTEGER, c1),
+ 3992                                                   qr);
+ 3993                                                 t := SymTab.IntType();
+ 3994                                                 QbeGen.CopyOp(qr, q)
+ 3995                                               ELSE SemError(217);
+ 3996                                                 t := SymTab.InvalidType;
+ 3997                                                 QbeGen.CopyOp("0", q)
+ 3998                                               END
+ 3999                                             ELSIF SymTab.ClassOf(dt) #
+ 4000                                                   SymTab.ClArray THEN
+ 4001                                               SemError(217);
+ 4002                                               t := SymTab.InvalidType;
+ 4003                                               QbeGen.CopyOp("0", q)
+ 4004                                             ELSE
+ 4005                                                IF SymTab.IsOpenArray(dt) THEN
+ 4006                                                  t := SymTab.IntType();
+ 4007                                                  QbeGen.CopyOp("@", q)
+ 4008                                                ELSE
+ 4009                                                  IF isHigh THEN
+ 4010                                                    QbeGen.IntStr(
+ 4011                                                      SymTab.ArrayHi(dt), qr)
+ 4012                                                  ELSE
+ 4013                                                    QbeGen.IntStr(VAL(
+ 4014                                                      INTEGER,
+ 4015                                                      SymTab.ArrayLen(dt)),
+ 4016                                                      qr)
+ 4017                                                  END;
+ 4018                                                  t := SymTab.IntType();
+ 4019                                                  QbeGen.CopyOp(qr, q)
+ 4020                                                END
+ 4021                                              END; .)
+ 4022      | ( "SIZE" | "TSIZE" ) "(" Design<dt, dk, qd, qn, sfx> ")"
+ 4023      (. astNode := AST.MakeNode(AST.NkCall);
+ 4024     AST.SetChild(astNode, 0, AST.MakeLeaf(AST.NkIdent, "SIZE"));
+ 4025     IF astCur # AST.NoNode THEN AST.SetChild(astNode, 1, astCur) END;
+ 4026     astCur := astNode; astIsLit := TRUE; .)
+ 4027                                          (. IF dt = SymTab.InvalidType THEN
+ 4028                                               t := SymTab.InvalidType;
+ 4029                                               QbeGen.CopyOp("0", q)
+ 4030                                             ELSE
+ 4031                                               QbeGen.IntStr(VAL(INTEGER,
+ 4032                                                 SymTab.ObjectSize(dt)), q);
+ 4033                                               t := SymTab.IntType()
+ 4034                                             END; .)
+ 4035      | ( "SHIFT"                         (. isMax := FALSE; .)
+ 4036        | "ROTATE"                        (. isMax := TRUE; .) )
+ 4037        "(" Expr<et, q> (. astArg2 := astCur; .) "," Expr<et2, q2> ")"
+ 4038                                          (. astNode := AST.MakeNode(AST.NkCall);
+ 4039     IF isMax THEN AST.SetChild(astNode, 0,
+ 4040       AST.MakeLeaf(AST.NkIdent, "ROTATE"))
+ 4041     ELSE AST.SetChild(astNode, 0,
+ 4042       AST.MakeLeaf(AST.NkIdent, "SHIFT")) END;
+ 4043     IF astArg2 # AST.NoNode THEN AST.SetChild(astNode, 1, astArg2) END;
+ 4044     IF astCur # AST.NoNode THEN AST.SetChild(astNode, 2, astCur) END;
+ 4045     astCur := astNode; astIsLit := TRUE;
+ 4046                                             (* set shift/rotate: isMax
+ 4047                                                doubles as "rotate" *)
+ 4048                                             IF (et # SymTab.InvalidType)
+ 4049                                                AND (SymTab.ClassOf(et) =
+ 4050                                                   SymTab.ClSet) THEN
+ 4051                                                t := et;
+ 4052                                                QbeGen.CopyOp("@", q)
+ 4053                                             ELSE SemError(230);
+ 4054                                               t := SymTab.InvalidType;
+ 4055                                               QbeGen.CopyOp("0", q)
+ 4056                                             END; .)
+ 4057      | ( "MIN"                           (. isMax := FALSE; .)
+ 4058        | "MAX"                           (. isMax := TRUE; .) )
+ 4059        "(" Design<dt, dk, qd, qn, sfx> ")"
+ 4060                                          (. astNode := AST.MakeNode(AST.NkCall);
+ 4061     IF isMax THEN AST.SetChild(astNode, 0,
+ 4062       AST.MakeLeaf(AST.NkIdent, "MAX"))
+ 4063     ELSE AST.SetChild(astNode, 0,
+ 4064       AST.MakeLeaf(AST.NkIdent, "MIN")) END;
+ 4065     IF astCur # AST.NoNode THEN AST.SetChild(astNode, 1, astCur) END;
+ 4066     astCur := astNode; astIsLit := TRUE;
+ 4067                                             IF (dt # SymTab.InvalidType)
+ 4068   AND (SymTab.ClassOf(dt) = SymTab.ClReal) THEN
+ 4069                                               (* REAL/LONGREAL: the
+ 4070                                                  implementation bounds *)
+ 4071                                               IF isMax THEN
+ 4072                                                 QbeGen.NormReal(
+ 4073                                                   "3.402823e38", q)
+ 4074                                               ELSE QbeGen.NormReal(
+ 4075                                                   "-3.402823e38", q)
+ 4076                                               END;
+ 4077                                               t := SymTab.RealType()
+ 4078                                             ELSIF (dt #
+ 4079                                                SymTab.InvalidType)
+ 4080   AND (SymTab.ClassOf(dt) =
+ 4081                                                   SymTab.ClLong) THEN
+ 4082                                               IF isMax THEN
+ 4083                                                 QbeGen.CopyOp(
+ 4084                                                   "9223372036854775807", q)
+ 4085                                               ELSE QbeGen.CopyOp(
+ 4086                                                   "-9223372036854775808", q)
+ 4087                                               END;
+ 4088                                               t := SymTab.LongType()
+ 4089                                             ELSIF SymTab.TypeBounds(dt, lo,
+ 4090                                                      hi) THEN
+ 4091                                               IF isMax THEN
+ 4092                                                 QbeGen.IntStr(hi, q)
+ 4093                                               ELSE QbeGen.IntStr(lo, q)
+ 4094                                               END;
+ 4095                                               (* a set's bounds are those
+ 4096                                                  of its base type *)
+ 4097                                               IF SymTab.ClassOf(dt) =
+ 4098                                                  SymTab.ClSet THEN
+ 4099                                                 t := SymTab.SetBase(dt)
+ 4100                                               ELSE t := SymTab.IntType()
+ 4101                                               END
+ 4102                                             ELSE SemError(230);
+ 4103                                               t := SymTab.InvalidType;
+ 4104                                               QbeGen.CopyOp("0", q)
+ 4105                                             END; .)
+ 4106      | "ADR" "(" Design<dt, dk, qd, qn, sfx> ")"
+ 4107      (. astNode := AST.MakeNode(AST.NkCall);
+ 4108     AST.SetChild(astNode, 0, AST.MakeLeaf(AST.NkIdent, "ADR"));
+ 4109     IF astCur # AST.NoNode THEN AST.SetChild(astNode, 1, astCur) END;
+ 4110     astCur := astNode; astIsLit := TRUE; .)
+ 4111                                          (. IF dt = SymTab.InvalidType THEN
+ 4112                                               t := SymTab.InvalidType;
+ 4113                                               QbeGen.CopyOp("0", q)
+ 4114                                             ELSE
+ 4115                                                IF sfx
+ 4116                                                   OR (dk = SymTab.KindVar)
+ 4117                                                   OR (dk = SymTab.KindParam) THEN
+ 4118                                                  QbeGen.CopyOp("@", q)
+ 4119                                                ELSE SemError(230);
+ 4120                                                  QbeGen.CopyOp("0", q)
+ 4121                                                END;
+ 4122                                               t := SymTab.AddrType()
+ 4123                                             END; .)
+ 4124      | "CHR" "(" Expr<et, q> ")"
+ 4125      (. astNode := AST.MakeNode(AST.NkCall);
+ 4126     AST.SetChild(astNode, 0, AST.MakeLeaf(AST.NkIdent, "CHR"));
+ 4127     IF astCur # AST.NoNode THEN AST.SetChild(astNode, 1, astCur) END;
+ 4128     astCur := astNode; astIsLit := TRUE; .)
+ 4129                                          (. IF (et # SymTab.InvalidType)
+ 4130   AND NOT SymTab.IsIntFamily(et) THEN
+ 4131                                               SemError(211) END;
+ 4132                                             t := SymTab.CharType(); .)
+ 4133      | "ORD" "(" Expr<et, q> ")"
+ 4134      (. astNode := AST.MakeNode(AST.NkCall);
+ 4135     AST.SetChild(astNode, 0, AST.MakeLeaf(AST.NkIdent, "ORD"));
+ 4136     IF astCur # AST.NoNode THEN AST.SetChild(astNode, 1, astCur) END;
+ 4137     astCur := astNode; astIsLit := TRUE; .)
+ 4138                                          (. IF et # SymTab.InvalidType THEN
+ 4139                                               IF (SymTab.ClassOf(et) #
+ 4140                                                   SymTab.ClChar)
+ 4141   AND (SymTab.ClassOf(et) #
+ 4142                                                     SymTab.ClBool)
+ 4143   AND (SymTab.ClassOf(et) #
+ 4144                                                     SymTab.ClEnum)
+ 4145   AND NOT SymTab.IsIntFamily(et)
+ 4146   AND NOT SymTab.IsPackedSet(et) THEN
+ 4147                                                 SemError(211) END
+ 4148                                             END;
+ 4149                                             t := SymTab.IntType(); .)
+ 4150      | "CAP" "(" Expr<et, q> ")"
+ 4151      (. astNode := AST.MakeNode(AST.NkCall);
+ 4152     AST.SetChild(astNode, 0, AST.MakeLeaf(AST.NkIdent, "CAP"));
+ 4153     IF astCur # AST.NoNode THEN AST.SetChild(astNode, 1, astCur) END;
+ 4154     astCur := astNode; astIsLit := TRUE; .)
+ 4155                                           (. IF QbeGen.IsImm(q)
+ 4156    AND SymTab.ConstInt(q, lo) THEN
+ 4157       IF (lo >= VAL(INTEGER, ORD("a"))) AND (lo <= VAL(INTEGER, ORD("z"))) THEN lo := lo - 32 END;
+ 4158       QbeGen.IntStr(lo, q)
+ 4159     ELSE QbeGen.CopyOp("@", q)
+ 4160     END;
+ 4161     t := SymTab.CharType(); .)
+ 4162      | "UCHR" "(" Expr<et, q> ")"
+ 4163      (. astNode := AST.MakeNode(AST.NkCall);
+ 4164     AST.SetChild(astNode, 0, AST.MakeLeaf(AST.NkIdent, "UCHR"));
+ 4165     IF astCur # AST.NoNode THEN AST.SetChild(astNode, 1, astCur) END;
+ 4166     astCur := astNode; astIsLit := TRUE; .)
+ 4167                                          (. (* UCHR: the UCHAR constructor.
+ 4168                                                CHAR -> UCHAR (identity);
+ 4169                                                INTEGER familly -> UCHAR
+ 4170                                                (codepoint value). *)
+ 4171                                             IF (et # SymTab.InvalidType)
+ 4172    AND (SymTab.ClassOf(et) # SymTab.ClChar)
+ 4173    AND NOT SymTab.IsIntFamily(et) THEN
+ 4174                                               SemError(211) END;
+ 4175                                             t := SymTab.UCharType(); .)
+ 4176      | "CHR8" "(" Expr<et, q> ")"
+ 4177      (. astNode := AST.MakeNode(AST.NkCall);
+ 4178     AST.SetChild(astNode, 0, AST.MakeLeaf(AST.NkIdent, "CHR8"));
+ 4179     IF astCur # AST.NoNode THEN AST.SetChild(astNode, 1, astCur) END;
+ 4180     astCur := astNode; astIsLit := TRUE; .)
+ 4181                                          (. IF (et # SymTab.InvalidType)
+ 4182    AND (SymTab.ClassOf(et) # SymTab.ClUChar) THEN
+ 4183                                               SemError(211) END;
+ 4184                                             t := SymTab.CharType(); .)
+ 4185      | "UORD" "(" Expr<et, q> ")"
+ 4186      (. astNode := AST.MakeNode(AST.NkCall);
+ 4187     AST.SetChild(astNode, 0, AST.MakeLeaf(AST.NkIdent, "UORD"));
+ 4188     IF astCur # AST.NoNode THEN AST.SetChild(astNode, 1, astCur) END;
+ 4189     astCur := astNode; astIsLit := TRUE; .)
+ 4190                                          (. (* UORD(u): the codepoint as a
+ 4191                                                32-bit ordinal (INTEGER),
+ 4192                                                cf. ORD for CHAR. *)
+ 4193                                             IF (et # SymTab.InvalidType)
+ 4194    AND (SymTab.ClassOf(et) # SymTab.ClUChar) THEN
+ 4195                                               SemError(211) END;
+ 4196                                             t := SymTab.IntType(); .)
+ 4197      | "ABS" "(" Expr<et, q> ")"
+ 4198      (. astNode := AST.MakeNode(AST.NkCall);
+ 4199     AST.SetChild(astNode, 0, AST.MakeLeaf(AST.NkIdent, "ABS"));
+ 4200     IF astCur # AST.NoNode THEN AST.SetChild(astNode, 1, astCur) END;
+ 4201     astCur := astNode; astIsLit := TRUE; .)
+ 4202                                          (. IF (et # SymTab.InvalidType)
+ 4203   AND NOT SymTab.IsIntFamily(et)
+ 4204   AND (SymTab.ClassOf(et) #
+ 4205                                                  SymTab.ClReal) THEN
+ 4206                                               SemError(211)
+ 4207                                              ELSIF QbeGen.IsImm(q)
+ 4208    AND SymTab.ConstInt(q, lo) THEN
+ 4209                                                IF lo < 0 THEN lo := -lo END;
+ 4210                                                QbeGen.IntStr(lo, q)
+ 4211                                              ELSE QbeGen.CopyOp("@", q)
+ 4212                                             END;
+ 4213                                             t := et; .)
+ 4214      | "ODD" "(" Expr<et, q> ")"
+ 4215      (. astNode := AST.MakeNode(AST.NkCall);
+ 4216     AST.SetChild(astNode, 0, AST.MakeLeaf(AST.NkIdent, "ODD"));
+ 4217     IF astCur # AST.NoNode THEN AST.SetChild(astNode, 1, astCur) END;
+ 4218     astCur := astNode; astIsLit := TRUE; .)
+ 4219                                          (. IF (et # SymTab.InvalidType)
+ 4220   AND NOT SymTab.IsIntFamily(et) THEN
+ 4221                                               SemError(211) END;
+ 4222                                             t := SymTab.BoolType();
+ 4223                                             IF QbeGen.IsImm(q)
+ 4224    AND SymTab.ConstInt(q, lo) THEN
+ 4225                                               IF (lo MOD 2) # 0 THEN
+ 4226                                                 QbeGen.CopyOp("1", q)
+ 4227                                               ELSE QbeGen.CopyOp("0", q)
+ 4228                                               END
+ 4229                                             ELSE QbeGen.CopyOp("@", q)
+ 4230                                             END; .)
+ 4231      | "TRUNC" "(" Expr<et, q> ")"
+ 4232      (. (* TRUNC(x): real -> INTEGER, as the VAL builtin *)
+ 4233     astNode := AST.MakeNode(AST.NkCall);
+ 4234     AST.SetChild(astNode, 0, AST.MakeLeaf(AST.NkIdent, "VAL"));
+ 4235     AST.SetChild(astNode, 1, AST.MakeLeaf(AST.NkIdent, "INTEGER"));
+ 4236     IF astCur # AST.NoNode THEN AST.SetChild(astNode, 2, astCur) END;
+ 4237     astCur := astNode; astIsLit := TRUE; .)
+ 4238                                          (. t := SymTab.IntType();
+ 4239                                             QbeGen.CopyOp("@", q); .)
+ 4240      | "FLOAT" "(" Expr<et, q> ")"
+ 4241      (. (* FLOAT(i): integer -> REAL, as the VAL builtin *)
+ 4242     astNode := AST.MakeNode(AST.NkCall);
+ 4243     AST.SetChild(astNode, 0, AST.MakeLeaf(AST.NkIdent, "VAL"));
+ 4244     AST.SetChild(astNode, 1, AST.MakeLeaf(AST.NkIdent, "REAL"));
+ 4245     IF astCur # AST.NoNode THEN AST.SetChild(astNode, 2, astCur) END;
+ 4246     astCur := astNode; astIsLit := TRUE; .)
+ 4247                                          (. t := SymTab.RealType();
+ 4248     IF QbeGen.IsImm(q) AND SymTab.ConstInt(q, lo) THEN QbeGen.NormReal(q, qa); QbeGen.CopyOp(qa, q)
+ 4249     ELSE QbeGen.CopyOp("@", q) END; .)
+ 4250      | ( "VAL" | "CONVERT" | "CAST" ) "(" GetIdent<vn> (. astArg2 := AST.MakeLeaf(AST.NkIdent, vn); .) "," Expr<et, q> ")"
+ 4251      (. astNode := AST.MakeNode(AST.NkCall);
+ 4252     AST.SetChild(astNode, 0, AST.MakeLeaf(AST.NkIdent, "VAL"));
+ 4253     IF astArg2 # AST.NoNode THEN AST.SetChild(astNode, 1, astArg2) END;
+ 4254     IF astCur # AST.NoNode THEN AST.SetChild(astNode, 2, astCur) END;
+ 4255     astCur := astNode; astIsLit := TRUE; .)
+ 4256                                          (. IF NOT SymTab.Lookup(vn) THEN
+ 4257                                               SemError(201);
+ 4258                                               t := SymTab.InvalidType
+ 4259                                             ELSE vt := SymTab.SymType(vn);
+ 4260                                               IF vt = SymTab.InvalidType THEN
+ 4261                                                 t := SymTab.InvalidType
+ 4262                                               ELSIF et =
+ 4263                                                  SymTab.InvalidType THEN
+ 4264                                                 t := vt
+ 4265                                               ELSE
+ 4266                                                 c1 := SymTab.ClassOf(et);
+ 4267                                                 c2 := SymTab.ClassOf(vt);
+ 4268                                                 IF ((c1 = SymTab.ClInt)
+ 4269      OR (c1 = SymTab.ClByte) OR (c1 = SymTab.ClSByte)
+ 4270      OR (c1 = SymTab.ClWord16) OR (c1 = SymTab.ClSWord16))
+ 4271    AND (c2 = SymTab.ClLong) THEN
+ 4272                                                   IF NOT QbeGen.IsImm(q) THEN QbeGen.WidenLong(q, qa); QbeGen.CopyOp(qa, q) END;
+ 4273                                                   t := vt
+ 4274                                                 ELSIF (c1 = SymTab.ClLong)
+ 4275    AND ((c2 = SymTab.ClInt) OR (c2 = SymTab.ClByte)
+ 4276      OR (c2 = SymTab.ClSByte) OR (c2 = SymTab.ClWord16)
+ 4277      OR (c2 = SymTab.ClSWord16)) THEN
+ 4278                                                   IF NOT (QbeGen.IsImm(q) AND SymTab.ConstInt(q, lo)) THEN QbeGen.NarrowLong(q, qa); QbeGen.CopyOp(qa, q) END;
+ 4279                                                   t := vt
+ 4280                                                 ELSIF ((c1 = SymTab.ClInt)
+ 4281      OR (c1 = SymTab.ClByte) OR (c1 = SymTab.ClSByte)
+ 4282      OR (c1 = SymTab.ClWord16) OR (c1 = SymTab.ClSWord16))
+ 4283    AND (c2 = SymTab.ClReal) THEN
+ 4284                                                   IF QbeGen.IsImm(q) AND SymTab.ConstInt(q, lo) THEN QbeGen.NormReal(q, qa) ELSE QbeGen.ConvIR(q, qa) END;
+ 4285                                                   QbeGen.CopyOp(qa, q);
+ 4286                                                   t := vt
+ 4287                                                 ELSIF (c1 = SymTab.ClLong)
+ 4288    AND (c2 = SymTab.ClReal) THEN
+ 4289                                                   IF QbeGen.IsImm(q) AND SymTab.ConstInt(q, lo) THEN QbeGen.NormReal(q, qa) ELSE QbeGen.ConvLR(q, qa) END;
+ 4290                                                   QbeGen.CopyOp(qa, q);
+ 4291                                                   t := vt
+ 4292                                                 ELSIF (c1 = SymTab.ClReal)
+ 4293    AND ((c2 = SymTab.ClInt) OR (c2 = SymTab.ClByte)
+ 4294      OR (c2 = SymTab.ClSByte) OR (c2 = SymTab.ClWord16)
+ 4295      OR (c2 = SymTab.ClSWord16)) THEN
+ 4296                                                   QbeGen.ConvRI(q, qa);
+ 4297                                                   QbeGen.CopyOp(qa, q);
+ 4298                                                   t := vt
+ 4299                                                 ELSIF (c1 = SymTab.ClReal)
+ 4300    AND (c2 = SymTab.ClLong) THEN
+ 4301                                                   QbeGen.ConvRL(q, qa);
+ 4302                                                   QbeGen.CopyOp(qa, q);
+ 4303                                                   t := vt
+ 4304                                                 ELSIF (c1 = SymTab.ClLong)
+ 4305    AND (c2 = SymTab.ClLong) THEN
+ 4306                                                   t := vt
+ 4307                                                 ELSIF ((c1 = SymTab.ClInt)
+ 4308                                                     OR (c1 =
+ 4309                                                        SymTab.ClChar)
+ 4310                                                     OR (c1 =
+ 4311                                                        SymTab.ClBool)
+ 4312                                                     OR (c1 =
+ 4313                                                        SymTab.ClByte)
+ 4314                                                     OR (c1 =
+ 4315                                                        SymTab.ClSByte)
+ 4316                                                     OR (c1 =
+ 4317                                                        SymTab.ClWord16)
+ 4318                                                     OR (c1 =
+ 4319                                                        SymTab.ClSWord16)
+ 4320                                                     OR (c1 =
+ 4321                                                        SymTab.ClEnum))
+ 4322   AND ((c2 = SymTab.ClInt)
+ 4323                                                     OR (c2 =
+ 4324                                                        SymTab.ClChar)
+ 4325                                                     OR (c2 =
+ 4326                                                        SymTab.ClBool)
+ 4327                                                     OR (c2 =
+ 4328                                                        SymTab.ClByte)
+ 4329                                                     OR (c2 =
+ 4330                                                        SymTab.ClSByte)
+ 4331                                                     OR (c2 =
+ 4332                                                        SymTab.ClWord16)
+ 4333                                                     OR (c2 =
+ 4334                                                        SymTab.ClSWord16)
+ 4335                                                     OR (c2 =
+ 4336                                                        SymTab.ClEnum)) THEN
+ 4337                                                   t := vt
+ 4338                                                 ELSIF (c1 = SymTab.ClPtr)
+ 4339    AND (c2 = SymTab.ClPtr) THEN
+ 4340                                                   t := vt
+ 4341                                                 ELSIF ((c1 = SymTab.ClProc)
+ 4342    AND (c2 = SymTab.ClProc))
+ 4343    OR ((c1 = SymTab.ClProc) AND (c2 = SymTab.ClPtr))
+ 4344    OR ((c1 = SymTab.ClPtr) AND (c2 = SymTab.ClProc)) THEN
+ 4345                                                   t := vt
+ 4346                                                 ELSIF (c1 = SymTab.ClReal)
+ 4347   AND (c2 = SymTab.ClReal) THEN
+ 4348                                                   t := vt
+ 4349                                                 ELSIF ((c1 = SymTab.ClSet) AND (c2 = SymTab.ClInt))
+ 4350    OR ((c1 = SymTab.ClInt) AND (c2 = SymTab.ClSet)) THEN
+ 4351                                                   (* a set <-> its machine word (BITSET) *)
+ 4352                                                   t := vt
+ 4353                                                 ELSE SemError(230);
+ 4354                                                   t := SymTab.InvalidType
+ 4355                                                 END
+ 4356                                               END
+ 4357                                             END; .)
+ 4358      | "(" Expr<et, q> ")"               (. t := et; astIsLit := TRUE; .)
+ 4359      | SetLit<st, sq>                    (. astIsLit := TRUE; t := st;
+ 4360                                             QbeGen.CopyOp(sq, q); .)
+ 4361      | ( "NOT" | "~" ) Fact<t2, q2>      (. astNot := astCur;
+ 4362                                             IF SymTab.BoolCheck(t2) THEN
+ 4363                                               t := SymTab.BoolType()
+ 4364                                             ELSE SemError(212);
+ 4365                                               t := SymTab.InvalidType END;
+ 4366                                             IF t # SymTab.InvalidType THEN
+ 4367                                                QbeGen.CopyOp("@", q)
+ 4368                                             ELSE QbeGen.CopyOp("0", q)
+ 4369                                             END;
+ 4370                                             astIsLit := TRUE;
+ 4371                                             astCur := AST.MakeUn(
+ 4372                                               AST.NkUnary, AST.OpNot, astNot); .)
+ 4373      )
+ 4374      (. IF NOT astIsLit THEN astCur := AST.NoNode END; .)
+ 4375             (. IF astCur # AST.NoNode THEN AST.SetTy(astCur, t) END; .) .
+ 4376    (* Set literals are SET OF [0..255] (8 words); elements validated
+ 4377       0..255 statically when foldable (222 otherwise), runtime trap
+ 4378       for computed elements. Ranges always lower via SetRange. *)
+ 4379    SetLit<VAR t: SymTab.TypeIndex; VAR q: QbeGen.QVal>
+ 4380                                          (. VAR astNode: AST.Node; .)
+ 4381      = "{"                               (. t := SymTab.NewSet(
+ 4382                                               SymTab.NewSubR(0, 255));
+ 4383                                             astNode := AST.MakeNode(AST.NkSetLit);
+ 4384                                             QbeGen.NewSetTemp(8, q);
+ 4385                                             QbeGen.SetZero(q, 8); .)
+ 4386        [ SetElem<t, q, astNode> { "," SetElem<t, q, astNode> } ]
+ 4387        "}"                               (. astCur := astNode; .) .
+ 4388    (* Typed brace constructor: TypeName{ elems } — BITSET{0} (a set)
+ 4389       or ArrayName{...} (an array constructor, GNU Modula-2).  The
+ 4390       declared type sets the width (set) or element type (array). *)
+ 4391    TypedBraceLit<vt: SymTab.TypeIndex; VAR q: QbeGen.QVal>
+ 4392                                          (. VAR nw: CARDINAL;
+ 4393                                               astNode, astTail: AST.Node;
+ 4394                                               savedCls: INTEGER; .)
+ 4395      = "{"                               (. savedCls := braceCls;
+ 4396                                             astNode := AST.MakeNode(AST.NkBraceLit);
+ 4397                                             AST.SetTy(astNode, vt);
+ 4398                                             astTail := astNode;
+ 4399                                             IF vt = SymTab.InvalidType THEN
+ 4400                                               braceCls := -1
+ 4401                                             ELSE braceCls :=
+ 4402                                                    SymTab.ClassOf(vt)
+ 4403                                             END;
+ 4404                                             IF braceCls = SymTab.ClSet THEN
+ 4405                                               IF vt = SymTab.InvalidType THEN
+ 4406                                                 nw := 8
+ 4407                                               ELSE nw := SymTab.SetWords(vt);
+ 4408                                                 IF nw = 0 THEN nw := 8 END
+ 4409                                               END;
+ 4410                                               QbeGen.NewSetTemp(nw, q);
+ 4411                                               QbeGen.SetZero(q, nw)
+ 4412                                             ELSIF (braceCls =
+ 4413                                                    SymTab.ClArray)
+ 4414                                                OR (braceCls =
+ 4415                                                    SymTab.ClRecord)
+ 4416                                                OR (braceCls =
+ 4417                                                    SymTab.ClClass) THEN
+ 4418                                               QbeGen.CtorBegin(vt)
+ 4419                                             ELSE
+ 4420                                               IF vt # SymTab.InvalidType THEN
+ 4421                                                 SemError(230) END;
+ 4422                                               braceCls := -1
+ 4423                                             END; .)
+ 4424        [ BraceElem<vt, q, astNode, astTail>
+ 4425          { "," BraceElem<vt, q, astNode, astTail> } ]
+ 4426        "}"                               (. IF (braceCls = SymTab.ClArray)
+ 4427                                                OR (braceCls =
+ 4428                                                   SymTab.ClRecord)
+ 4429                                                OR (braceCls =
+ 4430                                                   SymTab.ClClass) THEN
+ 4431                                               QbeGen.CtorEnd(q)
+ 4432                                             ELSIF braceCls # SymTab.ClSet THEN
+ 4433                                               QbeGen.CopyOp("0", q)
+ 4434                                             END;
+ 4435                                             braceCls := savedCls; .)
+ 4436                                          (. astCur := astNode; .) .
+ 4437    BraceElem<vt: SymTab.TypeIndex; VAR sq: QbeGen.QVal;
+ 4438              VAR node, tail: AST.Node>
+ 4439                                          (. VAR et, et2: SymTab.TypeIndex;
+ 4440                                               qe, q2: QbeGen.QVal;
+ 4441                                               v, v2, reps, k: INTEGER;
+ 4442                                               elem: SymTab.TypeIndex;
+ 4443                                               lo: INTEGER;
+ 4444                                               span: CARDINAL;
+ 4445                                               cl, cl2: INTEGER;
+ 4446                                               hasR, hasB: BOOLEAN;
+ 4447                                               astEl: AST.Node; .)
+ 4448      =                                   (. hasR := FALSE; hasB := FALSE;
+ 4449                                             reps := 1; .)
+ 4450        Expr<et, qe> (. astEl := astCur; .)
+ 4451        [ ".." Expr<et2, q2>              (. astEl := AST.MakeBin(
+ 4452                                               AST.NkSubrange, 0, astEl, astCur);
+ 4453                                             hasR := TRUE; .) ]
+ 4454        [ "BY" Expr<et2, q2>              (. hasB := TRUE; .) ]
+ 4455                                          (. IF braceCls = SymTab.ClSet THEN
+ 4456                                               IF hasB THEN SemError(230) END;
+ 4457                                               lo := SymTab.SetBaseLo(vt);
+ 4458                                               span := SymTab.SetCount(vt);
+ 4459                                               IF (et = SymTab.InvalidType)
+ 4460                                                  OR (hasR AND (et2 =
+ 4461                                                     SymTab.InvalidType)) THEN
+ 4462                                               ELSE cl :=
+ 4463                                                      SymTab.ClassOf(et);
+ 4464                                                 IF hasR THEN
+ 4465                                                   cl2 :=
+ 4466                                                     SymTab.ClassOf(et2)
+ 4467                                                 ELSE cl2 := SymTab.ClInt
+ 4468                                                 END;
+ 4469                                                 IF NOT SymTab.SetElemClassOk(cl)
+ 4470                                                    OR (hasR AND NOT
+ 4471                                                       SymTab.SetElemClassOk(cl2))
+ 4472                                                 THEN
+ 4473                                                   SemError(222)
+ 4474                                                 ELSIF hasR
+ 4475   AND SymTab.ConstInt(qe, v)
+ 4476   AND SymTab.ConstInt(q2,
+ 4477                                                       v2)
+ 4478   AND ((v < lo)
+ 4479                                                       OR (v2 < lo)
+ 4480                                                       OR (v >= lo +
+ 4481                                                          VAL(INTEGER, span))
+ 4482                                                       OR (v2 >= lo +
+ 4483                                                          VAL(INTEGER, span))
+ 4484                                                       OR (v > v2)) THEN
+ 4485                                                   SemError(222)
+ 4486                                                  ELSIF hasR THEN
+ 4487                                                    QbeGen.SetRange(sq, qe, q2,
+ 4488                                                      lo, span)
+ 4489                                                  ELSIF SymTab.ConstInt(qe,
+ 4490                                                          v)
+ 4491   AND ((v < lo)
+ 4492                                                        OR (v >= lo +
+ 4493                                                           VAL(INTEGER,
+ 4494                                                             span))) THEN
+ 4495                                                    SemError(222)
+ 4496                                                  ELSE QbeGen.SetBit(sq, qe,
+ 4497                                                    lo, span)
+ 4498                                                 END
+ 4499                                               END
+ 4500                                             ELSIF (braceCls = SymTab.ClArray)
+ 4501                                                OR (braceCls =
+ 4502                                                   SymTab.ClRecord)
+ 4503                                                OR (braceCls =
+ 4504                                                   SymTab.ClClass) THEN
+ 4505                                               IF hasR THEN SemError(230) END;
+ 4506                                               reps := 1;
+ 4507                                               IF hasB THEN
+ 4508                                                 IF SymTab.ConstInt(q2, v2)
+ 4509   AND (v2 >= 1) THEN
+ 4510                                                   reps := v2
+ 4511                                                 ELSE SemError(230)
+ 4512                                                 END
+ 4513                                               END;
+ 4514                                               k := 0;
+ 4515                                               WHILE k < reps DO
+ 4516                                                 QbeGen.CtorElem(qe);
+ 4517                                                 INC(k)
+ 4518                                               END
+ 4519                                             END; .)
+ 4520                                          (. (* the BY form repeats the
+ 4521                                               element; keep the AST in
+ 4522                                               step with CtorElem *)
+ 4523                                             k := 0;
+ 4524                                             WHILE k < reps DO
+ 4525                                               AstAppend(AST.NkBlock,
+ 4526                                                 node, tail, astEl);
+ 4527                                               INC(k)
+ 4528                                             END; .) .
+ 4529    SetElem<st: SymTab.TypeIndex; sq: QbeGen.QVal; node: AST.Node>         (. VAR et, et2: SymTab.TypeIndex;
+ 4530                                               qe, q2: QbeGen.QVal;
+ 4531                                               v, v2: INTEGER;
+ 4532                                               lo: INTEGER;
+ 4533                                               span: CARDINAL;
+ 4534                                               cl, cl2: INTEGER;
+ 4535                                               hasR: BOOLEAN;
+ 4536                                               astEl: AST.Node; .)
+ 4537      =                                   (. hasR := FALSE; .)
+ 4538        Expr<et, qe> (. astEl := astCur; .)
+ 4539        [ ".." Expr<et2, q2>              (. astEl := AST.MakeBin(
+ 4540                                               AST.NkSubrange, 0, astEl, astCur);
+ 4541                                             hasR := TRUE; .) ]
+ 4542                                          (. lo := SymTab.SetBaseLo(st);
+ 4543                                             span := SymTab.SetCount(st);
+ 4544                                             IF (et = SymTab.InvalidType)
+ 4545                                                OR (hasR AND (et2 =
+ 4546                                                   SymTab.InvalidType)) THEN
+ 4547                                             ELSE cl :=
+ 4548                                                    SymTab.ClassOf(et);
+ 4549                                               IF hasR THEN
+ 4550                                                 cl2 :=
+ 4551                                                   SymTab.ClassOf(et2)
+ 4552                                               ELSE cl2 := SymTab.ClInt
+ 4553                                               END;
+ 4554                                               IF NOT SymTab.SetElemClassOk(cl)
+ 4555                                                  OR (hasR AND NOT
+ 4556                                                     SymTab.SetElemClassOk(cl2))
+ 4557                                               THEN
+ 4558                                                 SemError(222)
+ 4559                                               ELSIF hasR
+ 4560   AND SymTab.ConstInt(qe, v)
+ 4561   AND SymTab.ConstInt(q2,
+ 4562                                                     v2)
+ 4563   AND ((v < lo)
+ 4564                                                     OR (v2 < lo)
+ 4565                                                     OR (v >= lo +
+ 4566                                                        VAL(INTEGER, span))
+ 4567                                                     OR (v2 >= lo +
+ 4568                                                        VAL(INTEGER, span))
+ 4569                                                     OR (v > v2)) THEN
+ 4570                                                 SemError(222)
+ 4571                                                ELSIF hasR THEN
+ 4572                                                  QbeGen.SetRange(sq, qe, q2,
+ 4573                                                    lo, span)
+ 4574                                                ELSIF SymTab.ConstInt(qe,
+ 4575                                                        v)
+ 4576   AND ((v < lo)
+ 4577                                                      OR (v >= lo +
+ 4578                                                         VAL(INTEGER,
+ 4579                                                           span))) THEN
+ 4580                                                  SemError(222)
+ 4581                                                ELSE QbeGen.SetBit(sq, qe,
+ 4582                                                  lo, span)
+ 4583                                               END
+ 4584                                             END; .)
+ 4585                                          (. AST.SetChild(node,
+ 4586                                               AST.NChild(node), astEl); .) .
+ 4587    GetIdent<VAR n: SymTab.Name>
+ 4588      = ident                             (. LexName(n); .) .
+ 4589  
+ 4590  END M2.
 
     0 errors
 
 
 Statistics:
 
-  nr of terminals:       119 (limit   400)
+  nr of terminals:       121 (limit   400)
   nr of non-terminals:    93 (limit   210)
-  nr of pragmas:           0 (limit   381)
-  nr of symbolnodes:     212 (limit   500)
-  nr of graphnodes:     1373 (limit  1500)
+  nr of pragmas:           0 (limit   379)
+  nr of symbolnodes:     214 (limit   500)
+  nr of graphnodes:     1413 (limit  1500)
   nr of conditionsets:    12 (limit   100)
   nr of charactersets:    17 (limit   250)
 

+ 1 - 0
compiler/src/compiler.frm

@@ -122,6 +122,7 @@ MODULE -->Grammar;
         | 234: Msg("invalid UTF-8 in U-literal")
         | 235: Msg("implementation does not match definition")
         | 236: Msg("bad variant record")
+        | 237: Msg("RETRY outside EXCEPT")
         ELSE         Msg("Error: "); WriteInt(f, nr, 0);
         END
       END ErrText;

+ 28 - 0
compiler/tests/t_except_parse.mod

@@ -0,0 +1,28 @@
+MODULE TExceptParse;
+(* M1 parser/AST regression: EXCEPT is accepted on procedure and module
+   bodies, RETRY is accepted inside a handler, and an empty body with
+   only a handler parses.  Until M2, Lower deliberately rejects EXCEPT
+   with 230 so no handler is silently ignored; the test is an
+   expect_fail on "not supported yet". *)
+VAR ExitCode: INTEGER;
+
+PROCEDURE Set42;
+BEGIN
+  ExitCode := 42
+EXCEPT
+  ExitCode := 1;
+  RETRY
+END Set42;
+
+PROCEDURE EmptyBody;
+EXCEPT
+  ExitCode := 2
+END EmptyBody;
+
+BEGIN
+  ExitCode := 0;
+  Set42
+EXCEPT
+  ExitCode := 3;
+  RETRY
+END TExceptParse.

+ 5 - 0
compiler/tests/t_retry_bad.mod

@@ -0,0 +1,5 @@
+MODULE TRetryBad;
+(* M1 negative test: RETRY is only legal inside an EXCEPT handler. *)
+BEGIN
+  RETRY
+END TRetryBad.

+ 2 - 1
docs/INDEX.md

@@ -39,7 +39,8 @@ bisecting *why* a decision was made, not for reading end-to-end).
   layout (deferred until the compiler is finished).
 - **`design-exceptions.md`** — ISO exceptions design: grammar/AST,
   handler stack, `sigsetjmp`/`siglongjmp` codegen, `EXCEPTIONS` /
-  `M2EXCEPTION`, trap mapping, tests.  Design only; not implemented.
+  `M2EXCEPTION`, trap mapping, tests.  M1 parser/AST is implemented;
+  codegen/runtime is M2+.
 - `blaise-phases-map.md`, `language-report.md`, `grammar.md` — the
   grammar/phases reference.
 - `summary_l3_selfhost_fix.md` — the self-host root cause; also where

+ 5 - 4
docs/STATUS.md

@@ -4,9 +4,9 @@ This answers "where are we now?".
 
 ## Numbers
 
-- Suite **263/263** (`compiler/run_tests.sh`).
+- Suite **265/265** (`compiler/run_tests.sh`).
 - Self-hosting **FIXPOINT OK** — stage2 and stage3 images are
-  byte-identical (4,075,853 bytes).
+  byte-identical (4,091,107 bytes).
 - Corpus **511 / 612** sources compile with 0 errors, **0 crashes**
   (`tools/v3-corpus/corpus.sh` over the gm2 testsuite; the harness now
   resolves V3's own shipped libraries); the rest are genuine language
@@ -171,7 +171,8 @@ declarations still work (`t_fwdproc`, `t_fwdok`).
    `INC`/`DEC`, leading CASE `|`, `__FUNCTION__`).  Corpus is **511/612**
    at the stop point.  The remaining `LANG` entries are mostly:
    **declaration order** cases V3 rejects by policy (`docs/gaps/`); ISO
-   exceptions (design in `docs/design-exceptions.md`); multi-dimensional
+   exceptions (M1 parser/AST only; codegen pending — see
+   `docs/design-exceptions.md`); multi-dimensional
    open arrays (representation, see `docs/handoff-2026-10-23-next.md`);
    and gm2-only extensions.  See `docs/analysis_gaps.md`.
 2. ~~**The size-sensitive V3 miscompile**~~ — **root-caused and fixed**
@@ -214,7 +215,7 @@ declarations still work (`t_fwdproc`, `t_fwdok`).
 ```sh
 cd compiler
 ./build.sh          # M2.atg -> scanner/parser/driver -> ./M2
-./run_tests.sh      # 263/263
+./run_tests.sh      # 265/265
 cd ..
 ./bootstrap/fixpoint.sh   # FIXPOINT OK (byte-identical stage2/stage3)
 ```

+ 1 - 1
docs/comparison-PIM4-gm2-V3.md

@@ -1,7 +1,7 @@
 # PIM4 vs GNU Modula-2 vs M2R10 vs TopSpeed V3 vs V3 — feature comparison
 
 **Date:** 2026-10-23 · **V3 state:** `v3-packedset` (suite
-263/263, self-hosting fixpoint OK 4,075,853 bytes, corpus 511/612,
+265/265, self-hosting fixpoint OK 4,091,107 bytes, corpus 511/612,
 0 crashes).
 
 **Scope and sources.**

+ 12 - 6
docs/design-exceptions.md

@@ -1,8 +1,11 @@
 # Design — ISO exceptions for V3
 
-**Status: design only (2026-10-23).**  Nothing in this document is
-implemented yet.  Baseline: `v3-packedset`; suite **263/263**, fixpoint
-OK **4,075,853 bytes**, corpus **511/612**, 0 crashes.
+**Status: design + M1 parser/AST (2026-10-23).**  `EXCEPT` and `RETRY`
+are in the grammar and AST, and `RETRY` placement is checked; codegen
+and the runtime are not implemented, so any `EXCEPT` currently reports
+a loud `230` (M2 removes that).  Baseline: `v3-packedset`; suite
+**265/265**, fixpoint OK **4,091,107 bytes**, corpus **511/612**,
+0 crashes.
 
 The handoff calls this the largest remaining language feature.  This
 document fixes the syntax, AST, runtime model, code-generation contract,
@@ -555,6 +558,9 @@ location"`, `"divide by zero"`.
 
 Add to `compiler/run_tests.sh`:
 
+- `t_except_parse`: grammar/AST acceptance test.  Until M2 it is an
+  `expect_fail` on `230`; after M2 it becomes an `expect_run`.
+- `t_retry_bad`: `RETRY` outside `EXCEPT` rejected with `237`.
 - `t_except_basic`: `RAISE` from a nested procedure, handler checks
   `CurrentNumber`, `GetMessage`, `IsCurrentSource`,
   `IsExceptionalExecution`; exit 42.
@@ -608,10 +614,10 @@ fixpoint OK (size will change), corpus **512/612** (only
 
 ## 10. Milestones
 
-1. **M1 — parser/AST**
+1. **M1 — parser/AST** — **done (2026-10-23)**
    - `EXCEPT`, `RETRY`; `NkExcept`/`NkRetry`; `RETRY` placement check;
-     `EXCEPT` accepted in procedure, implementation, program and local
-     module bodies.  No codegen yet.
+     `EXCEPT` accepted in procedure, implementation, program, local
+     module and class bodies.  `EXCEPT` reports `230` until M2.
 2. **M2 — runtime + codegen for user `RAISE`**
    - `m2_exc_*` handler stack, `ExcBegin`/`ExcBodyDone`/`ExcHandlerBegin`/
      `ExcEnd`/`ExcRetry`, `EmitRet` pop, `m2_exc_init` in `main`.

+ 3 - 3
docs/features.md

@@ -154,9 +154,9 @@ Legend: ✅ done · 🔄 partial · ⏸ not started / deferred.
   composite function results (record/array/set/class, sret) and chained
   post-call method calls (`F().M()`); ⏸ per-file object emission, import
   cycles.
-- ⏸ ISO exceptions (`EXCEPT`/`RETRY`, `EXCEPTIONS`, `M2EXCEPTION`,
-  language exceptions); design in `docs/design-exceptions.md`, not
-  implemented.
+- 🔄 ISO exceptions: M1 parser/AST only (`EXCEPT`/`RETRY`, `NkExcept`/
+  `NkRetry`, `RETRY` placement); `EXCEPT` reports `230` until codegen
+  and the runtime land.  Design in `docs/design-exceptions.md`.
 
 ## Backend (QBE)
 - ✅ Length-prefixed arrays (count + elements), deep record copy,

+ 6 - 6
docs/gaps/README.md

@@ -94,12 +94,12 @@ gap22_file_line.mod             invalid Fact            (__LINE__)
 
 ## Genuine gaps (worth fixing, standard Modula-2)
 
-- **ISO exceptions — design ready, not implemented** (2026-10-23):
-  `EXCEPT`/`RETRY`, `EXCEPTIONS`, `M2EXCEPTION`, language-exception
-  detection.  `lazyunique` is the only corpus file that should become a
-  genuine +1; `except2/4/5/7/8/9` still fail declaration order because
-  `ip` is declared after the procedures.  See
-  `docs/design-exceptions.md`.
+- **ISO exceptions — M1 parser/AST done, codegen pending** (2026-10-23):
+  `EXCEPT`/`RETRY` and the AST nodes are in place, with `RETRY`
+  placement checking; `EXCEPT` reports `230` until M2 adds the runtime
+  and codegen.  `lazyunique` therefore stays `LANG` for now.
+  `except2/4/5/7/8/9` still fail declaration order because `ip` is
+  declared after the procedures.  See `docs/design-exceptions.md`.
 - **`libc` prototypes — fixed** (2026-10-22): the known C functions
   now have real signatures (`exit`, `write`/`read`/`open`/`close`/
   `lseek`, `malloc`, `memcpy`/`memset`/`strncpy`, `system`/`getenv`,

+ 20 - 10
docs/handoff-2026-10-23-next.md

@@ -1,7 +1,7 @@
 # Next session — plan (from 2026-10-23)
 
 **Branch:** `master`.  **Feature state:** `v3-packedset`.
-**Gates:** suite **263/263**, fixpoint **OK (4,075,853 bytes)**,
+**Gates:** suite **265/265**, fixpoint **OK (4,091,107 bytes)**,
 corpus **511/612, 0 crashes**.
 
 Read first: `docs/STATUS.md`, `docs/features.md`,
@@ -26,11 +26,21 @@ inside `assert` before its declaration (declaration order, rejected by
 policy).  With `r` moved before the procedure they compile and run.
 Do not relax declaration order for this corpus case.
 
-## 2. ISO exceptions — design first (`docs/design-exceptions.md`)
+## 2. ISO exceptions — M1 done, M2 next (`docs/design-exceptions.md`)
 
-A dedicated feature session, not a small fix.  Start with the design in
+A dedicated feature session, not a small fix.  The design is in
 `docs/design-exceptions.md` (grammar/AST, handler stack, `sigsetjmp`/
-`siglongjmp` codegen, `EXCEPTIONS`/`M2EXCEPTION`, trap mapping, tests):
+`siglongjmp` codegen, `EXCEPTIONS`/`M2EXCEPTION`, trap mapping, tests).
+
+**M1 parser/AST — done (2026-10-23).**  `EXCEPT`/`RETRY` are reserved
+words; bodies carry `NkExcept`/`NkRetry`; `RETRY` outside a handler is
+error **237**.  `EXCEPT` deliberately reports **230** until M2 so no
+handler is silently ignored.  Regressions: `t_except_parse`
+(`expect_fail` on 230 for now) and `t_retry_bad` (237).
+
+Next (M2): runtime handler stack + `sigsetjmp`/`siglongjmp` codegen,
+`EmitRet` pop, `m2_exc_init`, then positive `RAISE`/`RETRY`/`RETURN`
+tests.  Still to implement across M2–M5:
 
 - `EXCEPT` / `RETRY` after a normal statement sequence (procedures,
   implementation/program/local module bodies);
@@ -87,7 +97,7 @@ this feature.
 ## Gates for every step
 
 ```sh
-cd compiler && ./build.sh && ./run_tests.sh          # 263/263
+cd compiler && ./build.sh && ./run_tests.sh          # 265/265
 cd .. && TMP="$PWD/.scratch/fixpoint" ./bootstrap/fixpoint.sh
 tools/v3-corpus/corpus.sh                            # 511 OK, 0 crash
 ```
@@ -100,12 +110,12 @@ session summary; commit with a `v3-*` tag.  Do not push without asking.
 ```sh
 cd .../m2compiler-V3
 git checkout master
-cd compiler && ./build.sh && ./run_tests.sh          # 263/263
+cd compiler && ./build.sh && ./run_tests.sh          # 265/265
 cd .. && TMP="$PWD/.scratch/fixpoint" ./bootstrap/fixpoint.sh
 tools/v3-corpus/corpus.sh                            # 511 OK, 0 crash
 ```
 
-**Recommendation:** start the **ISO exceptions** design (the largest
-remaining language feature), or take the multi-dimensional-open-array
-ABI decision if you prefer an ABI task.  Library folders and separate
-compilation remain deferred (`docs/plan-separate-compilation.md`).
+**Recommendation:** continue with **M2 of ISO exceptions** (runtime +
+codegen), or take the multi-dimensional-open-array ABI decision if you
+prefer an ABI task.  Library folders and separate compilation remain
+deferred (`docs/plan-separate-compilation.md`).