code review 4524075: ld: fix and simplify ELF symbol generation

ld: fix and simplify ELF symbol generation

I started looking at this code because the nm in GNU
binutils was ignoring the first symbol in the .symtab
section.  Apparently, the System V ABI reserves the
first entry and requires all fields inside to be set
to zero.

The list of changes is as follows:

  · reserve the first symbol entry (as noted above)
  · fix the section indices for .data and .bss symbols
  · factor out common code for Elf32 and Elf64
  · remove the special case for elfsymo in [568]l/asm.c:/^asmb
  · add the "etext" symbol in 6l
  · add static symbols

[ality, 2011-05-27 12:38:31]

Hello rsc@golang.org (cc: golang-dev@googlegroups.com),

I'd like you to review this change to
https://go.googlecode.com/hg/

[rsc, 2011-05-31 16:47:07]

LGTM

Thanks for cleaning that up.

[ality, 2011-06-02 22:00:09]

rsc@golang.org once said:
> LGTM
> 
> Thanks for cleaning that up.

Can you please submit this?

Thanks,
  Anthony

[rsc, 2011-06-07 18:26:22]

*** Submitted as http://code.google.com/p/go/source/detail?r=ceedefce68ad ***

ld: fix and simplify ELF symbol generation

I started looking at this code because the nm in GNU
binutils was ignoring the first symbol in the .symtab
section.  Apparently, the System V ABI reserves the
first entry and requires all fields inside to be set
to zero.

The list of changes is as follows:

  · reserve the first symbol entry (as noted above)
  · fix the section indices for .data and .bss symbols
  · factor out common code for Elf32 and Elf64
  · remove the special case for elfsymo in [568]l/asm.c:/^asmb
  · add the "etext" symbol in 6l
  · add static symbols

R=rsc
CC=golang-dev
http://codereview.appspot.com/4524075

Committer: Russ Cox <rsc@golang.org>