llvm dev - Jul 2021 - [DebugInfo] Enabling constructor homing by default in clang

Thanks Amy! + a few folks to highlight this.

On Thu, Jul 15, 2021 at 11:06 AM Amy Huang via llvm-dev <
llvm-dev at lists.llvm.org> wrote:
> A while back I tried turning on constructor homing
> (-debug-info-kind=constructor) by default in clang. Ctor homing is a debug
> info optimization that reduces the amount of debug info that is emitted for
> class types.
>
> The main blocker was that for some libc++ types we avoid calling the
> constructor. Since then I've added a attribute for classes that ignores
> ctor homing (`__attribute__((standlone_debug))`) and added it to the libc++
> types (7c2f58278e66).
>
> I think at this point we can try enabling it by default in Clang --
it's
> currently being used in chromium and google codebases. Thought I'd
email
> the llvm-dev list in case people have thoughts/opinions/concerns about
> this. (patch is at https://reviews.llvm.org/D106084)
> _______________________________________________
> LLVM Developers mailing list
> llvm-dev at lists.llvm.org
> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://lists.llvm.org/pipermail/llvm-dev/attachments/20210715/d20116f3/attachment.html>

Thanks for letting us know. Is my understanding correct that "enabling by
default" means when -flimit-debuginfo would be used, or would it also
affect -fstandalone-debuginfo?

As always, please watch the
https://green.lab.llvm.org/green/view/LLDB/job/lldb-cmake
<https://green.lab.llvm.org/green/view/LLDB/job/lldb-cmake> bot after
making debug info changes.

thanks,
adrian
> On Jul 15, 2021, at 11:14 AM, David Blaikie <dblaikie at gmail.com>
wrote:
> 
> Thanks Amy! + a few folks to highlight this.
> 
> On Thu, Jul 15, 2021 at 11:06 AM Amy Huang via llvm-dev <llvm-dev at
lists.llvm.org <mailto:llvm-dev at lists.llvm.org>> wrote:
> A while back I tried turning on constructor homing
(-debug-info-kind=constructor) by default in clang. Ctor homing is a debug info
optimization that reduces the amount of debug info that is emitted for class
types.
> 
> The main blocker was that for some libc++ types we avoid calling the
constructor. Since then I've added a attribute for classes that ignores ctor
homing (`__attribute__((standlone_debug))`) and added it to the libc++ types
(7c2f58278e66).
> 
> I think at this point we can try enabling it by default in Clang --
it's currently being used in chromium and google codebases. Thought I'd
email the llvm-dev list in case people have thoughts/opinions/concerns about
this. (patch is at https://reviews.llvm.org/D106084
<https://reviews.llvm.org/D106084>)
> 
> _______________________________________________
> LLVM Developers mailing list
> llvm-dev at lists.llvm.org <mailto:llvm-dev at lists.llvm.org>
> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
<https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev>
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://lists.llvm.org/pipermail/llvm-dev/attachments/20210715/2317c3fc/attachment.html>