Re: compiling binutils with -DDEBUG

[Ian Lance Taylor <ian at airs dot com>]

Alan Modra <amodra@bigpond.net.au> writes:

> On Mon, Feb 28, 2005 at 09:36:00PM -0500, Ian Lance Taylor wrote:
> > Alan Modra <amodra@bigpond.net.au> writes:
> > 
> > > 	(fixup_segment): Remove assertion.
> > > Didn't seem worth including struct-symbol.h just for this.  I suspect
> > > the assertion isn't true too, since a similar assertion in obj-coff.c
> > > fails with X_op an O_constant.  Maybe this is a real bug.  Ian, you're
> > > probably the only one who can answer mri mode queries off the top of
> > > your head.  Care to comment?
> > 
> > > @@ -2583,7 +2585,6 @@ fixup_segment (fixS *fixP, segT this_seg
> > >        if (fixP->fx_addsy != NULL
> > >  	  && symbol_mri_common_p (fixP->fx_addsy))
> > >  	{
> > > -	  know (fixP->fx_addsy->sy_value.X_op == O_symbol);
> > >  	  add_number += S_GET_VALUE (fixP->fx_addsy);
> > >  	  fixP->fx_offset = add_number;
> > >  	  fixP->fx_addsy
> > 
> > The assertion should be true.  This is a symbol defined in an MRI
> > common section.  Since we don't generate IEEE object files, we treat
> > an MRI common section as a single large common symbol.  Then we handle
> > a reloc against a symbol defined within an MRI common section as an
> > offset to that symbol.  The assertion is just checking that we really
> > do point to the magic symbol we are using for the MRI common section.
> 
> I did a little analysis.  Nowadays, the assertion is always false for
> BFD_ASSEMBLER because symbols have been resolved (write.c:1857) by the
> time this code is reached.  The following would probably fix the
> assertion, but I don't think it's worth worrying about.

There is code in resolve_symbol_value() to handle this case.  I wonder
why it isn't working?  If the assert in fixup_segment() fails, then
MRI common symbols will not be handled correctly.

Whether anybody actually cares is another issue.

Ian