Re: Linker plugins should be aware of --defsym during symbol resolution

[Cary Coutant <ccoutant at gmail dot com>]

>> // The GNU linker lets symbol assignments in the linker script
>> // silently override defined symbols in object files.  We are
>> // compatible.  FIXME: Should we issue a warning?
>>
>> I think this is a misfeature, and the comment suggests that Ian thought so too.
>
> FWIW, so do I, but see the following in ld/ldexp.c
>
>                   if (!update_definedness (tree->assign.dst, h) && 0)
>                     {
>                       /* Symbol was already defined.  For now this error
>                          is disabled because it causes failures in the ld
>                          testsuite: ld-elf/var1, ld-scripts/defined5, and
>                          ld-scripts/pr14962.  Some of these no doubt
>                          reflect scripts used in the wild.  */
>                       (*link_info.callbacks->multiple_definition)
>                         (&link_info, h, link_info.output_bfd,
>                          expld.result.section, expld.result.value);
>                     }
>
> ld-elf/var1 and ld-scripts/pr14962 both came from real-world use by
> a boot loader.

Yeah, I had a feeling it would be problematic to fix it.

-cary