From: Jan Beulich <jbeulich@suse.com>
To: Ian Lance Taylor <iant@google.com>
Cc: "Maciej W. Rozycki" <macro@orcam.me.uk>,
Chenghua Xu <paul.hua.gm@gmail.com>,
Binutils <binutils@sourceware.org>
Subject: Re: non-conformant ELF symbol table on MIPS?
Date: Fri, 28 Jul 2023 08:16:47 +0200 [thread overview]
Message-ID: <a9322e6a-e42b-63af-bb67-5621770651e7@suse.com> (raw)
In-Reply-To: <CAKOQZ8waWqzSrqM8R6A=j=RsQRdrXvs1SdcCd6mNDXQUdtJjSw@mail.gmail.com>
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
next prev parent reply other threads:[~2023-07-28 6:16 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-27 14:27 Jan Beulich
2023-07-27 19:04 ` Ian Lance Taylor
2023-07-27 19:39 ` Maciej W. Rozycki
2023-07-28 6:16 ` Jan Beulich [this message]
2023-07-28 17:11 ` Ian Lance Taylor
2023-07-28 23:58 ` Alan Modra
2023-07-27 19:28 ` Maciej W. Rozycki
2023-07-28 6:13 ` Jan Beulich
2023-07-28 7:18 ` Jan Beulich
2023-07-28 6:18 ` Jan Beulich
2023-07-28 6:56 ` Maciej W. Rozycki
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