Re: Regression on qsort_cmp [Re: status of Darwin support]

[Jack Howarth <howarth at bromo dot med dot uc dot edu>]

On Tue, Sep 08, 2009 at 11:31:16AM +0200, Tristan Gingold wrote:
>
> On Aug 25, 2009, at 10:46 AM, Jan Kratochvil wrote:
>
>> On Tue, 11 Aug 2009 10:27:55 +0200, Christian Thalinger wrote:
>>> objfiles.c:793: internal-error: qsort_cmp: Assertion  
>>> `obj_section_endaddr (sect1) <= sect2_addr' failed.
>>
>> Getting randomly this error or:
>> objfiles.c:817: internal-error: preferred_obj_section: Assertion `(a- 
>> >objfile->separate_debug_objfile == b->objfile) || (b->objfile- 
>> >separate_debug_objfile == a->objfile)' failed.
>>
>> which have both the same reason that solibs overlap in VMAs.
>>
>> IMO these assertions are right and GDB should rather refuse to load
>> overlapping sections.  Still they may(?) be required for overlays,  
>> actively in
>> use for IBM Cell (as I was considering overlays as obsolete before  
>> myself).
>
> Still late in the game, but I think I now understand the issue:
>
> On Darwin, debug info are kept in object files.  To make gdb work, we  
> load the executable but also the
> symbols from its object files.  In update_section map we don't make the 
> difference between these two.
>
> IMHO we should slightly extend the notion of separate_debug_objfile so  
> that Darwin could use it and
> then modify update_section_map to correctly deals with that.
>
> Instead of allowing one separate debug file per objfile, we should allow 
> many debug files (using a linked
> list) (The question of allowing one level or several levels is still  
> open).
>
> The section map would flatten the tree and maybe fill the holes in  
> separate debug files using the father.
>
> Well, that's the design I have in my mind...
>
> Tristan.

Tristan,
   When you have any test patches for this, I would be happy to
try them on x86_64-apple-darwin10 and i686-apple-darwin10 if you
don't have Snow Leopard installed yet.
                   Jack