Re: [Core] [RFA/DWARF2] Handle nested subprograms in CU pc bound calculation

["Daniël Mantione" <daniel.mantione@freepascal.org>]

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Op Wed, 1 Oct 2008, schreef Joel Brobecker:

> The answer to the question above lies in the Pascal parser. But when
> there are homonyms, how do you specify in your program exactly which
> one you mean? And does GDB provide the same method for distinguishing
> these homonyms?
>
> (need to relearn Pascal one of these days...)

Pascal has a stack based symbol resolving (we call it the symtablestack in 
the compiler). For example take for example the following program:

program my_program;

uses unit_a,unit_b,unit_c;

var a:integer;

procedure main_procedure;

   var a:integer;

   procedure sub_procedure;

   var a:integer;

   begin
     a:=1;
     main_procedure.a:=1;
     my_program.a:=1;
     unit_a.a:=1;
     unit_b.a:=1;
     unit_c.a:=1;
   end;

begin
end;

So each procedure context can redefine identifiers.

Inside sub_procedure, the symtablestack will look like:

unit_a
unit_b
unit_c
my_program
main_procedure
sub_procedure

When searching for a symbol, the compiler will search the symbol tables 
bottom to top, starting at sub_procedure, ending at unit_a, the first 
symbol found is used. GDB would need to implement the same behaviour in 
it's Pascal mode.

Daniël