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Date: Mon, 13 Nov 2017 15:51:40 -0800
From: Andi Kleen <ak@linux.intel.com>
Subject: Re: CONFIG_DEBUG_INFO_SPLIT impacts on faddr2line
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To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Fengguang Wu <fengguang.wu@intel.com>, Jeff Kirsher <jeffrey.t.kirsher@intel.com>, Network Development <netdev@vger.kernel.org>, "David S. Miller" <davem@davemloft.net>, Linux Kernel Mailing List <linux-kernel@vger.kernel.org>, intel-wired-lan@lists.osuosl.org, Michal Marek <mmarek@suse.cz>, Sam Ravnborg <sam@ravnborg.org>, Dirk Gouders <dirk@gouders.net>, Linux Kbuild mailing list <linux-kbuild@vger.kernel.org>, kbuild test robot <lkp@intel.com>, "Zhang, Rui" <rui.zhang@intel.com>, "Lu, Aaron" <aaron.lu@intel.com>, "H.J. Lu" <hjl.tools@gmail.com>

> I wonder if there is some way to use the split format for the
> intermediate files, but then for the very final link bring them all in
> and make the end result be a traditional single binary. I'm not
> talking the separate "dwp" package that packs multiple dwo files into
> one, but to actually link them all in at the one.
> 
> Sure, it would lose some of the advantage, but I think a large portion
> of the -gsplit-dwarf advantage is about the intermediate state. No?

Not sure it's worth to do complicated workarounds. I assume
it will be not that difficult to fix binutils (after all
gdb works), and disabling the option is a reasonable workaround.

> 
> I tried to google for it, but couldn't find anything. But apparently
> elfutils doesn't support dwo files either. It seems mainly the linker
> and gdb itself that supports it.

The original design document is

https://gcc.gnu.org/wiki/DebugFission

-Andi