[RFA-v2] dwarf debug format: Support DW_AT_variable_parameter attribute

["Pierre Muller" <pierre dot muller at ics-cnrs dot unistra dot fr>]

  So, here is a new version of this patch.

  I will  try to improve reference type handling inside the
pascal specific sources later.

  Does that look OK?

Pierre

 
2010-05-20  Pierre Muller  <muller@ics.u-strasbg.fr>

	* dwarf2read.c (new_symbol): Handle DW_AT_variable_parameter
	attribute.

Index: dwarf2read.c
===================================================================
RCS file: /cvs/src/src/gdb/dwarf2read.c,v
retrieving revision 1.386
diff -u -p -r1.386 dwarf2read.c
--- dwarf2read.c        17 May 2010 15:55:01 -0000      1.386
+++ dwarf2read.c        19 May 2010 22:29:04 -0000
@@ -8662,6 +8662,15 @@ new_symbol (struct die_info *die, struct
            {
              dwarf2_const_value (attr, sym, cu);
            }
+         attr = dwarf2_attr (die, DW_AT_variable_parameter, cu);
+         if (attr && DW_UNSND (attr))
+           {
+             struct type *ref_type;
+
+             ref_type = lookup_reference_type (SYMBOL_TYPE (sym));
+             SYMBOL_TYPE (sym) = ref_type;
+           }
+
          add_symbol_to_list (sym, cu->list_in_scope);
          break;
        case DW_TAG_unspecified_parameters:

> -----Message d'origine-----
> De?: gdb-patches-owner@sourceware.org [mailto:gdb-patches-
> owner@sourceware.org] De la part de Tom Tromey
> Envoyé?: Thursday, May 20, 2010 12:09 AM
> À?: Pierre Muller
> Cc?: 'Joel Brobecker'; gdb-patches@sourceware.org; 'FPC Core Developer
> List'
> Objet?: Re: [RFA] dwarf debug format: Support DW_AT_variable_parameter
> attribute
> 
> >>>>> "Pierre" == Pierre Muller <pierre.muller@ics-cnrs.unistra.fr>
> writes:
> 
> Pierre>   That is what is done for now on Free Pascal,
> Pierre> i.e. the debug information generates a reference_type for
> Pierre> parameters passed by var.
> Pierre>   It's not ideal yet, but this is just a matter of
> Pierre> twicks inside p-* files...
> 
> I suppose it is less than ideal in that the type is exposed to the
> user.
> 
> Another idea would be to augment the DWARF expression evaluator to do
> an
> additional indirection when this bit is set.  Though then one must
> wonder why the compiler does not simply emit an expression to that
> effect.
> 
> Pierre>   I am unsure about the type allocation procedure,
> Pierre> could you just tell me if this looks OK
> Pierre> before I resubmit an RFA.
> 
> Pierre> +             struct type *ref_type;
> Pierre> +
> Pierre> +             ref_type = TYPE_REFERENCE_TYPE (SYMBOL_TYPE
> (sym));
> Pierre> +             if (!ref_type)
> Pierre> +               {
> Pierre> +                 ref_type = alloc_type (objfile);
> Pierre> +                 ref_type = make_reference_type (SYMBOL_TYPE
> (sym),
> Pierre> &ref_type);
> Pierre> +               }
> 
> Just use 'lookup_reference_type (SYMBOL_TYPE (sym))'.
> That will handle the details for you.
> 
> Tom