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From: Jason Merrill <jason@redhat.com>
To: Jan Kratochvil <jan.kratochvil@redhat.com>
Cc: gcc-patches List <gcc-patches@gcc.gnu.org>, gdb-patches@sourceware.org
Subject: Re: ping^2: [gcc patch] DWARF-5: Define DW_IDX_GNU_static and DW_IDX_GNU_external
Date: Sun, 02 Jul 2017 16:23:00 -0000	[thread overview]
Message-ID: <CADzB+2=DtngmkCX7NySKSPNZZ98WOsvAcT_R+qy1R7E3ubr8RQ@mail.gmail.com> (raw)
In-Reply-To: <20170702072543.GA5822@host1.jankratochvil.net>

On Sun, Jul 2, 2017 at 3:25 AM, Jan Kratochvil
<jan.kratochvil@redhat.com> wrote:
> http://dwarfstd.org/ShowIssue.php?issue=170527.1
>
> 170527.1 Jan Kratochvil DW_IDX_* for static/extern symbols Enhancement Open
>
> Section 6.1.1.4.7, pg 147
> When a debugger wants to print 'somename' it logically tries to find first 'somename' as an
> external symbol in all available libraries.  Only if none such external symbol is found the
> debugger starts searching for a static 'somename' symbol in those libraries.
>
> This requires to know whether a symbol in .debug_names index has DW_AT_external or not.
> Otherwise a lot of needless CU expansions happen.  This extension improves performance
> gain of the .debug_names index.
>
> (Discovered in an original fix by Doug Evans - GDB Bug 14125.)
>
> Proposing and asking for pre-allocation:
>   DW_IDX_static   = 6 = DW_FORM_flag_present = DIE's DW_AT_external is not present
>   DW_IDX_external = 7 = DW_FORM_flag_present = DIE's DW_AT_external is present

I'd suggest "internal" rather than "static".  Otherwise the patch looks good.

Jason

  reply	other threads:[~2017-07-02 16:23 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-05-26 18:17 Jan Kratochvil
2017-06-14 19:05 ` Jan Kratochvil
2017-06-23  8:58 ` ping: " Jan Kratochvil
2017-07-02  7:25   ` ping^2: " Jan Kratochvil
2017-07-02 16:23     ` Jason Merrill [this message]
2017-07-02 20:02       ` [gcc commit] " Jan Kratochvil

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