From: Ian Lance Taylor <iant@google.com>
To: vkutuzov@accesssoftek.com
Cc: binutils <binutils@sourceware.org>
Subject: Re: {GOLD][PATCH PROPOSAL] prevent discarding of needed local symbols for the relocatable objects
Date: Thu, 11 Feb 2010 02:14:00 -0000 [thread overview]
Message-ID: <mcraavgcydc.fsf@dhcp-172-17-9-151.mtv.corp.google.com> (raw)
In-Reply-To: <1265843004.2150.342.camel@dp690-dev5v4> (Viktor Kutuzov's message of "Wed\, 10 Feb 2010 15\:03\:24 -0800")
Viktor Kutuzov <vkutuzov@accesssoftek.com> writes:
> I'm trying to cross build llvm and llvm-gcc on Linux for ARM by using
> GOLD as the linker. This has exposed some problems we have in GOLD.
>
> One of them related to the assert in the relocate_for_relocatable()
> method (target-reloc.h, line 557):
>
> new_symndx = object->symtab_index(r_sym);
> gold_assert(new_symndx != -1U);
>
> This assert gets triggered when the build links glibc with the -r -X
> flags (remove local symbols).
>
> This happens because with the given -X option GOLD removes all local
> symbols, including those which still needed to resolve static relocs
> later.
>
> LD keeps that kind of local symbols in the symbol table even if -X
> requested. I guess GOLD should do the same.
>
> Please find attached the patch that fixes this issue.
Thanks, but this patch doesn't work. It fails the testsuite. The
problem is that at the time your patch checks
needs_output_symtab_entry, it will always return true.
needs_output_symtab_entry will only return false if
set_no_output_symtab_entry has been called, and that only happens at
the end of the loop you patched.
I think what we need to do here is mark the local symbol as
appropriate in scan_relocatable_relocs. The use of the
output_symtab_index_ field right now is a bit complicated. It is
initialized to 0. In Sized_relobj::do_count_local_symbols we set the
field to -1 if the symbol is not needed. In
Sized_relobj::do_finalize_local_symbols, if the field is still 0, we
set it to the index in the output file. Perhaps we should change that
0 == uninitialized, -1 == no index, -2 == needs index. Then
do_finalize_local_symbols should never see 0.
Ian
next prev parent reply other threads:[~2010-02-11 2:14 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-02-10 23:03 Viktor Kutuzov
2010-02-11 2:14 ` Ian Lance Taylor [this message]
2010-02-25 0:02 ` [GOLD][PATCH " Viktor Kutuzov
2010-03-03 19:34 ` Ian Lance Taylor
2011-05-10 22:30 ` Cary Coutant
2011-05-10 23:56 ` Ian Lance Taylor
2011-05-11 0:30 ` Cary Coutant
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