Re: MIPS -gc-sections broken?

[Nick Clifton <nickc at redhat dot com>]

Hi Hiroki,

> I've tried latest binutils-2.19.51.0.8 and gcc-4.5-20090604, and I still
> have the same problem...

> Humm, I'm using mips2 insn with o32.

Well I added the -mabi=32 switch to my command line to select the o32 
ABI but the link still works. :-(

Exactly how was the toolchain that you are using configured ?

One thing that you might like to try is adding the -fno-common to your 
gcc command line.  Perhaps the problem is associated with the garbage 
collection of common symbols.

> binutils/bfd/elfxx-mips.c:_bfd_mips_elf_gc_sweep_hook() is currently
> #if 0 'ed, however, other arch, such as arm, ppc reduces refcont for
> plt. MIPS does not have plt count, but while sweeping away section 
> .text.func_not_used and .rel.text.func_not_used, don't we need some
> handling of relocation entries in these sections?

Possibly, although this comment in the code would seem to suggest that 
the MIPS toolchains are not really designed to support this kind of thing:

   /* ??? It would seem that the existing MIPS code does no sort
           of reference counting or whatnot on its GOT and PLT entries,
	   so it is not possible to garbage collect them at this time.

Maybe the issue is with the loader that you are using to start the 
execution of your program.  Perhaps loaders for MIPS executables need to 
be able to ignore relocations for discarded symbols ?

Cheers
  Nick