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Re: [PATCH] Use libbacktrace as libsanitizer's symbolizer
- From: Alexey Samsonov <samsonov at google dot com>
- To: Jakub Jelinek <jakub at redhat dot com>
- Cc: Konstantin Serebryany <kcc at gcc dot gnu dot org>, Ian Lance Taylor <iant at google dot com>, GCC Patches <gcc-patches at gcc dot gnu dot org>
- Date: Wed, 27 Nov 2013 17:30:42 +0400
- Subject: Re: [PATCH] Use libbacktrace as libsanitizer's symbolizer
- Authentication-results: sourceware.org; auth=none
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On Wed, Nov 27, 2013 at 4:51 PM, Jakub Jelinek <firstname.lastname@example.org> wrote:
> On Wed, Nov 27, 2013 at 04:31:48PM +0400, Alexey Samsonov wrote:
>> LLVM emits just a DW_AT_low_pc ("base address" of a compilation unit). The
>> standard tells that compilation unit entries "may have" attributes
>> specifying the
>> address range, but doesn't tell they are obligatory.
>> DWARF consumers probably shouldn't rely on their presence.
> DWARF is generally full of may have and almost no must have. If the
> DWARF consumer crashes on absence of some attribute/die etc., that would
> be of course a consumer's fault. But not being able to symbolize something
> because the provided DWARF info omits important stuff is not wrong.
Ok, I agree to call it "missing feature" instead of "bug" =)
> BTW, libbacktrace also uses symbol table (and for backtrace_syminfo
> uses that exclusively), so even if it can't symbolize using DWARF info,
> it should at least symbolize using symbol table (of course inlining info
> isn't available in that case, nor tail call frames (but libbacktrace doesn't
> support those yet, only GDB does so far)).
Yes, symbol table symbolization works for me (it has no file/line
info, of course).
Alexey Samsonov, MSK