RFH: libgcc_s.so being unnecessarily linked for mipsel-linux crosscompiler...

[David Daney]

Daniel Jacobowitz wrote:
> On Thu, Jul 28, 2005 at 07:39:57PM -0700, David Daney wrote:
> 
>>It seems that the linker thinks that any shared object that references 
>>the magic _gp_disp symbol actually provides it.  Since all mips objects 
>>reference _gp_disp, ld thinks that all shared objects are required to 
>>resolve all the other _gp_disp references.  This causes all shared 
>>objects specified with --as-needed to be deemed needed and get a 
>>DT_NEEDED entry.
>>
>>The linker automagically resolves _gp_disp so this symbol should not 
>>cause a shared library to be needed.
>>
>>I hope that makes at least a little sense.
>>
>>I suspect that the problem is mips specific as _gp_disp handling is mips 
>>specific.
> 
> 
> Yes, you're probably right.  I thought this sounded familiar, but
> couldn't find any references.

Here is my current plan:

$ mipsel-linux-readelf -s -D -W 
/usr/local/mipsel-linux-3.4.3/lib/libc-2.3.3.so | grep SECTION
   131 324: 0019bfb0     0  SECTION GLOBAL DEFAULT ABS _gp_disp


This seems to be where ld thinks that _gp_disp is defined by shared objects.

I can detect this special case in _bfd_mips_elf_add_symbol_hook() and 
cause it to be ignored, thus solving the problem.

Does this seem like a reasonable course of action?

I am not sure how that dynamic symbol got into the shared objects in the 
first place.  I suppose if the proper solution was to not put it there 
in the first place, I could fix that and rebuild the world.  But that 
would be much more work.

David Daney.