Re: ANNOUNCE: pahole v1.23 (BTF tags and alignment inference)

From: Arnaldo Carvalho de Melo <acme@kernel.org>
To: Nathan Chancellor <nathan@kernel.org>
Cc: dwarves@vger.kernel.org,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	bpf@vger.kernel.org, Jiri Olsa <jolsa@kernel.org>,
	Jan Engelhardt <jengelh@inai.de>,
	Domenico Andreoli <domenico.andreoli@linux.com>,
	Matthias Schwarzott <zzam@gentoo.org>, Yonghong Song <yhs@fb.com>,
	Douglas RAILLARD <douglas.raillard@arm.com>,
	Ilya Leoshkevich <iii@linux.ibm.com>,
	Matteo Croce <mcroce@microsoft.com>
Subject: Re: ANNOUNCE: pahole v1.23 (BTF tags and alignment inference)
Date: Wed, 15 Dec 2021 11:56:19 -0300	[thread overview]
Message-ID: <YboCE3zig9papNQW@kernel.org> (raw)
In-Reply-To: <YbkTAPn3EEu6BUYR@archlinux-ax161>

Em Tue, Dec 14, 2021 at 02:56:16PM -0700, Nathan Chancellor escreveu:
> Hi Arnaldo,
> 
> On Wed, Dec 08, 2021 at 10:54:56AM -0300, Arnaldo Carvalho de Melo wrote:
> > - Initial support for DW_TAG_skeleton_unit, so far just suggest looking up a
> >   matching .dwo file to be used instead. Automagically doing this is in the
> >   plans for a future release.
> 
> This change [1] appears to break building on older distributions for me,
> which I use in containers for access to older versions of GCC. I see the
> error with Debian Stretch and Ubuntu Xenial, which have an older
> libelf-dev.  Is this expected? I don't mind sticking with 1.22 for
> those, I just want to be sure!

Nope, not expected, I'll reproduce here, fix and push, thanks for the
report.

- Arnaldo

> /tmp/dwarves-1.23/dwarf_loader.c: In function 'die__process':
> /tmp/dwarves-1.23/dwarf_loader.c:2529:13: error: 'DW_TAG_skeleton_unit' undeclared (first use in this function)
>   if (tag == DW_TAG_skeleton_unit) {
>              ^
> 
> [1]: https://git.kernel.org/pub/scm/devel/pahole/pahole.git/commit/?id=0135ccd632796ab3aff65b7c99b374c4682c2bcf
> 
> Cheers,
> Nathan

-- 

- Arnaldo