Theia-Modula-2/grammars/Modula2.atg

(*
   GNU Modula-2 grammar converted from GCC's gm2-ebnf.texi
   for testing with the GNU Modula-2 version of Coco/R.

   IMPORTANT:
   The GCC EBNF deliberately leaves the lexical productions Ident,
   Integer, Real and string as built-ins.  Therefore the lexical rules
   below are a TEST lexer, not a claim that they exactly reproduce every
   GNU Modula-2 lexical extension.  The syntactic productions are a
   mechanical conversion of the supplied GCC EBNF.

   Source: GNU Modula-2 gm2-ebnf.texi (GCC, 2000-2026).
*)

COMPILER GM2

CHARACTERS
  letter   = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz".
  octDigit = "01234567".
  digit    = octDigit + '89'.
  hexDigit = digit + 'ABCDEF'.
  eol      = CHR(13).
  noQuote1 = ANY - "'" - eol.
  noQuote2 = ANY - '"' - eol.

IGNORE CHR(9) .. CHR(13)

COMMENTS FROM "(*" TO "*)" NESTED

TOKENS
  Ident   = letter { letter | digit | "_" }.
  Integer = digit { digit }
          | digit { digit } CONTEXT ("..")
          | octDigit { octDigit } ("B" | "C")
          | digit { hexDigit } "H".

  (* A real literal requires digits after the decimal point.  This is
     important for ranges such as 0..39: the scanner must produce
     INTEGER DOTDOT INTEGER, not REAL followed by a dot. *)
  Real    = digit { digit } "." digit { digit }
            [ "E" [ "+" | "-" ] digit { digit } ].

  string  = "'" { noQuote1 } "'"
          | '"' { noQuote2 } '"'.





PRODUCTIONS
  GM2 = ( DefinitionModule | ImplementationOrProgramModule ).

  ProgramModule = "MODULE" Ident [ Priority ] ";" { Import } Block Ident ".".

  ImplementationModule = "IMPLEMENTATION" "MODULE" Ident [ Priority ] ";" { Import } Block Ident ".".

  ImplementationOrProgramModule = ImplementationModule | ProgramModule.

  Number = Integer | Real.
  Qualident = Ident { "." Ident }.
  ConstantDeclaration = Ident "=" ConstExpression.
  ConstExpression = SimpleConstExpr [ Relation SimpleConstExpr ].

  Relation = "=" | "#" | "<>" | "<" | "<=" | ">" | ">=" | "IN".

  SimpleConstExpr = UnaryOrConstTerm { AddOperator ConstTerm }.

  UnaryOrConstTerm = "+" ConstTerm | "-" ConstTerm | ConstTerm.

  AddOperator = "+" | "-" | "OR".

  ConstTerm = ConstFactor { MulOperator ConstFactor }.

  MulOperator = "*" | "/" | "DIV" | "MOD" | "REM" | "AND" | "&".

  ConstFactor = Number | ConstString | ConstSetOrQualidentOrFunction | "(" ConstExpression ")" | "NOT" ConstFactor | "~" ConstFactor | ConstAttribute.

  ConstString = string.

  ComponentElement = ConstExpression [ ".." ConstExpression ].

  ComponentValue = ComponentElement [ "BY" ConstExpression ].

  ArraySetRecordValue = ComponentValue { "," ComponentValue }.

  Constructor = "{" [ ArraySetRecordValue ] "}".

  ConstSetOrQualidentOrFunction = Constructor | Qualident [ Constructor | ConstActualParameters ].

  ConstActualParameters = "(" [ ExpList ] ")".

  ConstAttribute = "__ATTRIBUTE__" "__BUILTIN__" "(" "(" ConstAttributeExpression ")" ")".

  ConstAttributeExpression = Ident | "<" Qualident "," Ident ">".

  ByteAlignment = "<*" AttributeExpression "*>".

  Alignment = [ ByteAlignment ].

  TypeDeclaration = Ident "=" Type Alignment.

  Type = SimpleType | ArrayType | RecordType | SetType | PointerType | ProcedureType.

  SimpleType = Qualident [ SubrangeType ] | Enumeration | SubrangeType.

  Enumeration = "(" IdentList ")".

  IdentList = Ident { "," Ident }.

  SubrangeType = "[" ConstExpression ".." ConstExpression "]".

  ArrayType = "ARRAY" SimpleType { "," SimpleType } "OF" Type.

  RecordType = "RECORD" [ DefaultRecordAttributes ] FieldListSequence "END".

  DefaultRecordAttributes = "<*" AttributeExpression "*>".

  RecordFieldPragma = [ "<*" FieldPragmaExpression { "," FieldPragmaExpression } "*>" ].

  FieldPragmaExpression = Ident [ "(" ConstExpression ")" ].

  AttributeExpression = Ident "(" ConstExpression ")".

  FieldListSequence = FieldListStatement { ";" FieldListStatement }.

  FieldListStatement = [ FieldList ].

  FieldList = IdentList ":" Type RecordFieldPragma | "CASE" CaseTag "OF" Varient { "|" Varient } [ "ELSE" FieldListSequence ] "END".

  TagIdent = [ Ident ].

  CaseTag = TagIdent [ ":" Qualident ].

  Varient = [ VarientCaseLabelList ":" FieldListSequence ].

  VarientCaseLabelList = VarientCaseLabels { "," VarientCaseLabels }.

  VarientCaseLabels = ConstExpression [ ".." ConstExpression ].

  CaseLabelList = CaseLabels { "," CaseLabels }.

  CaseLabels = ConstExpression [ ".." ConstExpression ].

  SetType = ( "SET" | "PACKEDSET" ) "OF" SimpleType.

  PointerType = "POINTER" "TO" Type.

  ProcedureType = "PROCEDURE" [ FormalTypeList ].

  FormalTypeList = "(" ( ")" FormalReturn | ProcedureParameters ")" FormalReturn ).

  FormalReturn = [ ":" OptReturnType ].

  OptReturnType = "[" Qualident "]" | Qualident.

  ProcedureParameters = ProcedureParameter { "," ProcedureParameter }.

  ProcedureParameter = "..." | "VAR" FormalType | FormalType.

  VarIdent = Ident [ "[" ConstExpression "]" ].

  VariableDeclaration = VarIdentList ":" Type Alignment.

  VarIdentList = VarIdent { "," VarIdent }.

  Designator = Qualident { SubDesignator }.

  SubDesignator = "." Ident | "[" ExpList "]" | "^".

  ExpList = Expression { "," Expression }.

  Expression = SimpleExpression [ Relation SimpleExpression ].

  SimpleExpression = [ "+" | "-" ] Term { AddOperator Term }.

  Term = Factor { MulOperator Factor }.

  Factor = Number | string | SetOrDesignatorOrFunction | "(" Expression ")" | "NOT" Factor | "~" Factor | ConstAttribute.

  SetOrDesignatorOrFunction = ( Qualident [ Constructor | SimpleDes [ ActualParameters ] ] | Constructor ).

  SimpleDes = { "." Ident | "[" ExpList "]" | "^" }.

  ActualParameters = "(" [ ExpList ] ")".

  Statement = [ AssignmentOrProcedureCall | IfStatement | CaseStatement | WhileStatement | RepeatStatement | LoopStatement | ForStatement | WithStatement | AsmStatement | "EXIT" | "RETURN" [ Expression ] | RetryStatement ].

  RetryStatement = "RETRY".

  AssignmentOrProcedureCall = Designator ( ":=" Expression | ActualParameters | ).

  StatementSequence = Statement { ";" Statement }.

  IfStatement = "IF" Expression "THEN" StatementSequence { "ELSIF" Expression "THEN" StatementSequence } [ "ELSE" StatementSequence ] "END".

  CaseStatement = "CASE" Expression "OF" Case { "|" Case } [ "ELSE" StatementSequence ] "END".

  Case = [ CaseLabelList ":" StatementSequence ].

  WhileStatement = "WHILE" Expression "DO" StatementSequence "END".

  RepeatStatement = "REPEAT" StatementSequence "UNTIL" Expression.

  ForStatement = "FOR" Ident ":=" Expression "TO" Expression [ "BY" ConstExpression ] "DO" StatementSequence "END".

  LoopStatement = "LOOP" StatementSequence "END".

  WithStatement = "WITH" Designator "DO" StatementSequence "END".

  ProcedureDeclaration = ProcedureHeading ";" ( ProcedureBlock Ident ).

  DefineBuiltinProcedure = [ "__ATTRIBUTE__" "__BUILTIN__" "(" "(" Ident ")" ")" | "__INLINE__" ].

  ProcedureHeading = "PROCEDURE" DefineBuiltinProcedure ( Ident [ FormalParameters ] AttributeNoReturn ).

  AttributeNoReturn = [ "<*" Ident "*>" ].

  AttributeUnused = [ "<*" Ident "*>" ].

  Builtin = [ "__BUILTIN__" | "__INLINE__" ].

  DefProcedureHeading = "PROCEDURE" Builtin ( Ident [ DefFormalParameters ] AttributeNoReturn ).

  ProcedureBlock = { Declaration } [ "BEGIN" BlockBody ] "END".

  Block = { Declaration } InitialBlock FinalBlock "END".

  InitialBlock = [ "BEGIN" BlockBody ].

  FinalBlock = [ "FINALLY" BlockBody ].

  BlockBody = NormalPart [ "EXCEPT" ExceptionalPart ].

  NormalPart = StatementSequence.

  ExceptionalPart = StatementSequence.

  Declaration = "CONST" { ConstantDeclaration ";" } | "TYPE" { TypeDeclaration ";" } | "VAR" { VariableDeclaration ";" } | ProcedureDeclaration ";" | ModuleDeclaration ";".

  DefFormalParameters = "(" [ DefMultiFPSection ] ")" FormalReturn.

  DefMultiFPSection = DefExtendedFP | FPSection [ ";" DefMultiFPSection ].

  FormalParameters = "(" [ MultiFPSection ] ")" FormalReturn.

  MultiFPSection = ExtendedFP | FPSection [ ";" MultiFPSection ].

  FPSection = NonVarFPSection | VarFPSection.

  DefExtendedFP = DefOptArg | "...".

  ExtendedFP = OptArg | "...".

  VarFPSection = "VAR" IdentList ":" FormalType [ AttributeUnused ].

  NonVarFPSection = IdentList ":" FormalType [ AttributeUnused ].

  OptArg = "[" Ident ":" FormalType [ "=" ConstExpression ] "]".

  DefOptArg = "[" Ident ":" FormalType "=" ConstExpression "]".

  FormalType = { "ARRAY" "OF" } Qualident.

  ModuleDeclaration = "MODULE" Ident [ Priority ] ";" { Import } [ Export ] Block Ident.

  Priority = "[" ConstExpression "]".

  Export = "EXPORT" ( "QUALIFIED" IdentList | "UNQUALIFIED" IdentList | IdentList ) ";".

  Import = "FROM" Ident "IMPORT" IdentList ";" | "IMPORT" IdentList ";".

  DefinitionModule = "DEFINITION" "MODULE" [ "FOR" string ] Ident ";" { Import } [ Export ] { Definition } "END" Ident ".".

  Definition = "CONST" { ConstantDeclaration ";" } | "TYPE" { Ident ( ";" | "=" Type Alignment ";" ) } | "VAR" { VariableDeclaration ";" } | DefProcedureHeading ";".

  AsmStatement = "ASM" [ "VOLATILE" ] "(" AsmOperands ")".

  NamedOperand = "[" Ident "]".

  AsmOperandName = [ NamedOperand ].

  AsmOperands = string [ ":" AsmList [ ":" AsmList [ ":" TrashList ] ] ].

  AsmList = [ AsmElement ] { "," AsmElement }.

  AsmElement = AsmOperandName string "(" Expression ")".

  TrashList = [ string ] { "," string }.

END GM2.