[PATCH] D30699: [ELF] - Stop producing broken output for R_386_GOT32X relocation.

[Rafael Espíndola via llvm-commits]

> [hjl at gnu-6 tmp]$ cat y.s
> .text
> .globl _start
> _start:
> cmp %eax, _start at GOT
> [hjl at gnu-6 tmp]$ gcc -m32 -c y.s
> [hjl at gnu-6 tmp]$ objdump -dwr y.o
>
> y.o:     file format elf32-i386
>
>
> Disassembly of section .text:
>
> 00000000 <_start>:
>    0: 39 05 00 00 00 00     cmp    %eax,0x0 2: R_386_GOT32 _start
> [hjl at gnu-6 tmp]$ ld -m elf_i386 y.o
> [hjl at gnu-6 tmp]$ objdump -dw a.out
>
> a.out:     file format elf32-i386
>
>
> Disassembly of section .text:
>
> 08048094 <_start>:
>  8048094: 39 05 fc 9f 04 08     cmp    %eax,0x8049ffc
> [hjl at gnu-6 tmp]$
>
> In this case, R_386_GOT32 is computed as G + A, not G + A - GOT.

OK, the current situation with gas and bfd ld is somewhat amusing. Given

mov _start at GOT, %eax
cmp _start at GOT, %eax

assembled with an old gas we get two R_386_GOT32. After linking, the result is

 8048094:       a1 fc ff ff ff          mov    0xfffffffc,%eax
 8048099:       3b 05 fc 9f 04 08       cmp    0x8049ffc,%eax

Would it be ok in your opinion then for an implementation to treat
R_386_GOT32X as just a relaxable R_386_GOT32 but unlike bfd produce
G+A for both the mov and cmp above?

Thanks,
Rafael