Re: [RFA/dwarf-2] Fix for the null record problem

[Joel Brobecker <brobecker at gnat dot com>]

Ping?

The patch is quite tiny, seems almost obvious, and Elena seemed happy
with it. But it didn't get in because she asked that a testcase be added
first (on Feb 19):
<<
the patch looks sensible, but I would like to see the testcase go in
at the same time, or we'll forget.
>>

The new testcase has been checked in now, so I was wondering if somebody
had a moment to have a look at it, and confirm Elena's first review?

Thanks,

> >  > I have found the source of the problem, and suggest the attached patch.
> >  > The problem was that GDB was mistakenly deducing that the empry record
> >  > was only a stub because of the lack of fields, and was therefore tagging
> >  > it with TYPE_FLAG_STUB. This is not correct. Instead, the right
> >  > approach, I believe, is to check for the DW_AT_declaration attribute.
> >  > 
> >  > 2004-02-19  J. Brobecker  <brobecker@gnat.com>
> >  > 
> >  >         * dwarf2read.c (read_structure_scope): Identify stub types
> >  >         using the DW_AT_declaration attribute.
> >  > 
> >  > tested on x86-linux. No regression. Fixes the testcase that was
> >  > proposed by Andrew (even though it is not legal C) and the Ada
> >  > case.
> >  > 
> >  > OK to apply?
> >  > 
> >  > Thanks,
> >  > -- 
> >  > Joel
> >  > 
> >  > Index: dwarf2read.c
> >  > ===================================================================
> >  > RCS file: /cvs/src/src/gdb/dwarf2read.c,v
> >  > retrieving revision 1.130
> >  > diff -u -p -r1.130 dwarf2read.c
> >  > --- dwarf2read.c	28 Jan 2004 18:43:06 -0000	1.130
> >  > +++ dwarf2read.c	19 Feb 2004 13:58:42 -0000
> >  > @@ -3077,6 +3077,9 @@ read_structure_scope (struct die_info *d
> >  >        TYPE_LENGTH (type) = 0;
> >  >      }
> >  >  
> >  > +  if (dwarf2_attr (die, DW_AT_declaration, cu) != NULL)
> >  > +    TYPE_FLAGS (type) |= TYPE_FLAG_STUB;
> >  > +
> >  >    /* We need to add the type field to the die immediately so we don't
> >  >       infinitely recurse when dealing with pointers to the structure
> >  >       type within the structure itself. */
> >  > @@ -3213,11 +3216,6 @@ read_structure_scope (struct die_info *d
> >  >        new_symbol (die, type, cu);
> >  >  
> >  >        do_cleanups (back_to);
> >  > -    }
> >  > -  else
> >  > -    {
> >  > -      /* No children, must be stub. */
> >  > -      TYPE_FLAGS (type) |= TYPE_FLAG_STUB;
> >  >      }
> >  >  
> >  >    processing_current_prefix = previous_prefix;

-- 
Joel