DEFINITION MODULE Compiler ;

(* TP3 single-pass Pascal -> 8086 compiler, in GNU Modula-2 (-fiso).

   Mirrors the original Turbo Pascal 3.0 compiler (TPSRC6 'turbo' entry,
   TPSRC7-10): a one-pass parser that reads the shared TextBuf as source
   and emits 8086 machine code directly into an internal code buffer, a
   patch list resolving forward references, TP3-style error reporting
   (error number + relative text position) and code/data size accounting.

   The shell (CmdCompile) will call Compile, then jump the editor to
   errPos on failure - exactly like the original errexit + editor2 path. *)

FROM SYSTEM IMPORT BYTE ;

PROCEDURE Compile (VAR errNo, errPos : CARDINAL) : BOOLEAN ;
(* Compile the current TextBuf as a Pascal program.  Returns TRUE on
   success (sizes available via CodeBytes / DataBytes).  On failure
   returns FALSE, errNo carries the TP3-style error number and errPos
   the relative source offset (0-based) for the editor. *)

PROCEDURE CodeBytes () : CARDINAL ;
(* emitted code size in bytes *)

PROCEDURE DataBytes () : CARDINAL ;
(* emitted data size in bytes - the program's own data, not counting the
   runtime or the fixed 4 KiB gap between code and data *)

PROCEDURE ImageBytes () : CARDINAL ;
(* total linked image size = runtime + program.  This is what a .COM writer
   must emit, padded on to DataBase + DataBytes by the linker. *)

PROCEDURE DataBase () : CARDINAL ;
(* image-absolute offset of the data area, rtSz + 1000H.  The linker places
   the program's globals here and zero-fills the gap after the code. *)

PROCEDURE ImageByteAt (i : CARDINAL) : BYTE ;
(* i-th byte of the whole image, runtime included, 0 past the end.  This is
   what a .COM would actually start with. *)

PROCEDURE CodeByteAt (i : CARDINAL) : BYTE ;
(* i-th byte of the emitted image (0 past the end), so tests can check the
   generated 8086 code itself and not only its size *)

END Compiler.