Date: Thu, 30 Jul 2020 11:46:05 +0300
From: Timo Teras <timo.teras@iki.fi>
To: Natanael Copa <ncopa@alpinelinux.org>
Cc: "Alex Xu (Hello71)" <alex_y_xu@yahoo.ca>,
 ~alpine/devel@lists.alpinelinux.org
Subject: Re: Debug symbol compression
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On Tue, 7 Jul 2020 14:10:20 +0200
Natanael Copa <ncopa@alpinelinux.org> wrote:

> On Thu, 02 Jul 2020 13:09:19 -0400
> "Alex Xu (Hello71)" <alex_y_xu@yahoo.ca> wrote:
> 
> > Modern DWARF debugging sections can be compressed with zlib to save 
> > storage. This is done using the gcc -gz or objcopy 
> > --compress-debug-sections options.
> > 
> > Currently, Alpine does not compress debug sections. I think we
> > should consider doing so.  
> ...
>  
> > == Conclusions ==
> > 
> > Overall, I think that once libunwind is bumped to 1.5, we should
> > start compressing debug sections. We shouldn't support old bundled
> > versions of gdb or libunwind, and the installed size benefit is
> > substantial. In my opinion, the speed difference is negligible
> > compared to the size benefits. If we switch to zstd apk format,
> > then that will unfortunately likely need to be reverted.  
> 
> I think that makes sense. Lets bring it up again once libunwind 1.5 is
> out and our package is updated.

If libunwind needs backtracing for something real, it should first use
.eh_frame which contains the unwinding info.

The debug symbols are really needed for debugging only. And then we'd
likely be using gdb or something better anyway.

I think we can just go ahead and do this in edge if not done already.

Timo