non-conformant ELF symbol table on MIPS?

[Jan Beulich]

On 27.07.2023 21:04, Ian Lance Taylor wrote:
> On Thu, Jul 27, 2023 at 7:28 AM Jan Beulich via Binutils
> <binutils@sourceware.org> wrote:
>>
>> extending the gas elf/common3.s testcase (in the context of trying to fix
>> PR gas/30688) to
>>
>>         .comm foobar,30,4
>>         .comm buf1, 5-1, 8
>>         .comm buf2, 4, 9-1
>>         .lcomm lbuf, 9-1
>>
>> I notice a violation of the ELF spec on most (all?) MIPS targets I would
>> routinely test for common code changes: "lbuf" is emitted last in the
>> symbol table. The spec is quite clear: "In each symbol table, all
>> symbols with STB_LOCAL binding precede the weak and global symbols." I
>> guess I want/need to xfail that test for mips*-*-* for the time being,
>> but it would be nice if you could shed some light on this behavior.
> 
> This is historical behavior that dates back to the SGI Irix operating
> system.  Search for elf_bad_symtab in the BFD sources.  Here is the
> commend from elf-bfd.h:
> 
>   /* Irix 5 often screws up the symbol table, sorting local symbols
>      after global symbols.  This flag is set if the symbol table in
>      this BFD appears to be screwed up.  If it is, we ignore the
>      sh_info field in the symbol table header, and always read all the
>      symbols.  */
>   unsigned int bad_symtab : 1;
> 
> I believe we currently set elf_bad_symtab true by default for most MIPS targets.

That explains consuming behavior. But gas is a producer, and from what
you say and quote I can't see why gas also needs to produce non-
conforming symbol tables.

Jan