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MIPS_STABS_ELF is now broken

H . J . Lu hjl@lucon.org
Tue Jun 11 10:03:00 GMT 2002 
On Tue, Jun 11, 2002 at 12:49:00PM -0400, Daniel Jacobowitz wrote:
> > > 
> > > HJ, the debug information being emitted by GCC is obviously in error. 
> > > If you ignore the first .file directive, you will then not accept
> > > _VALID_ DWARF-2 debug information.  You can't have it both ways.  This
> > > is not the first time recently that an advance in GCC or binutils for
> > > Linux/MIPS has required a corresponding advance in the other.
> > > 
> > > Eric, if you think this sort of compatibility is important we could
> > > accept HJ's patch to ignore the first .file directive, and modify GCC
> > > to emit '.file "dummy"' or the like to make the situation clear.  I
> > > think this will just hurt our interactions with other assemblers,
> > > though.  We should probably talk about this.
> > 
> > On x86, gcc 3.1 emits
> > 
> >         .file   "f.c"
> >         .file 1 "f.c"
> >         .section        .debug_abbrev,"",@progbits
> > .Ldebug_abbrev0:
> > 
> > for dwarf. Can't mips take 2 .file directives?
> 
> See the difference between those two?  The first one is '.file "foo"',
> not '.file 1 "foo"'.  Unfortunately MIPS uses a '.file 1 "f.c"' for
> this.  I suppose we could document and tolerate this, however it is not
> enough.  GCC is still wrong.  Witness:
> 
> See how much is wrong there?  GCC needs to be fixed.
> 

I never said dwarf in gcc 3.1.1 was ok on Linux/mips. In fact, I even
submitted a patch to switch to stabs just so that I could debug programs
compiled with gcc 3.1.1. I appreciate your work on fixing dwarf in gcc and
gas. However, IMHO, it is not a good idea to break the existing gcc
binaries. Maybe we can add a new switch to gas, like "--debug=dwarf", to
tell gas that the directives are generated for dwarf.


H.J.
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