From: Richard Biener <richard.guenther@gmail.com>
To: Thomas Neumann <thomas.neumann@in.tum.de>
Cc: "Sören Tempel" <soeren@soeren-tempel.net>,
gcc-patches@gcc.gnu.org, alice@ayaya.dev
Subject: Re: [PATCH] Fix assertion for unwind-dw2-fde.c btree changes
Date: Mon, 15 May 2023 09:59:27 +0200 [thread overview]
Message-ID: <CAFiYyc04jT4+58etN6+Zz8F9=7Mr2keVVbcWFioNUeuVC4=Cqg@mail.gmail.com> (raw)
In-Reply-To: <23a59ecf-9f5e-4d55-9f31-48242b775ec7@in.tum.de>
On Sun, May 14, 2023 at 9:00 PM Thomas Neumann via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> Dear Sören,
>
> > we ran into a regression introduced by these changes. The regression
> > manifests itself in a failing assertion in __deregister_frame_info_bases.
> > The assertion failure was observed while using Chromium's `flatc` build
> > system tool. The failing assertion is:
> >
> > unwind-dw2-fde.c:281 gcc_assert (in_shutdown || ob);
> > [snip]
> > However, I believe there is one more edge case that isn't being account
> > for presently: If the inserted entry has a size of 0 (i.e. if range[1] -
> > range[0] == 0) then the btree_insert call in __register_frame_info_bases
> > will not insert anything. This is not accounted for in
> > [snip]
> >
> > Would be cool if this could be fixed on the GCC trunk.
>
> thanks for the details analysis and the patch, it looks obviously
> correct for me. I can apply it to trunk, but we need approval from a gcc
> maintainer first.
The patch is OK for trunk and affected branches.
Thanks,
Richard.
> But independent of your patch, do you have the test case available in
> some easily accessible form, for example a docker image or an automated
> build script? I ask because something odd is happening here, somebody
> registered a non-empty EH that does not contain a single unwind range. I
> am puzzled why anybody would do that, I would like to double check that
> this is indeed the intended behavior and not a bug somewhere else. Or if
> you have the test case at hand, it would be great if you could do a
> quick step through get_pc_range for the affected frame to double-check
> that the table is indeed empty and we don't miss an entry for some
> strange reason.
>
> Best
>
> Thomas
>
>
>
next prev parent reply other threads:[~2023-05-15 7:59 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-14 16:09 Sören Tempel
2023-05-14 18:59 ` Thomas Neumann
2023-05-14 19:52 ` alice
2023-05-14 22:35 ` Thomas Neumann
2023-05-14 23:09 ` alice
2023-05-15 7:59 ` Richard Biener [this message]
2023-05-15 12:52 ` Kyrylo Tkachov
2023-05-15 13:05 ` Thomas Neumann
2023-05-15 13:28 ` Kyrylo Tkachov
2023-05-15 13:31 ` Jeff Law
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