From: Luis Machado <luis.machado@linaro.org>
To: Tom Tromey <tom@tromey.com>
Cc: Tom Tromey <tromey@adacore.com>,
"gdb-patches\\@sourceware.org" <gdb-patches@sourceware.org>
Subject: Re: [PATCH] Find tailcall frames before inline frames
Date: Wed, 25 Mar 2020 23:47:20 -0300 [thread overview]
Message-ID: <CAD2_up-MJ85KaQ5k0KpNh2cruf5n5dFAYF7fjjGn+5Jmy_-7MA@mail.gmail.com> (raw)
In-Reply-To: <87blojdgfc.fsf@tromey.com>
On Wed, Mar 25, 2020, 22:59 Tom Tromey <tom@tromey.com> wrote:
> >>>>> "Luis" == Luis Machado <luis.machado@linaro.org> writes:
>
> Luis> Having spent a few days trying to understand this problem, it seems
> Luis> all of these fi->level assertions (including
> Luis> https://sourceware.org/bugzilla/show_bug.cgi?id=22748) are related
> to
> Luis> attempting to unwind from places not safe to do so. That is, we're
> Luis> trying to unwind some content (registers for example) before a given
> Luis> frame is assigned a frame id.
>
> Yes, I agree.
>
> Luis> I think dwarf2_tailcall_sniffer_first would have to be called from
> Luis> somewhere else, or conditions put in place. But I'm afraid adding
> more
> Luis> conditions would complicate things further. And this code is already
> Luis> reasonably complicated.
>
> Luis> Since this is causing a number of inlining test failures for aarch64
> Luis> and, from what i saw, some other architectures like s390, should we
> Luis> consider reverting this while we discuss/review a reworked version of
> Luis> the patch?
>
> I think that would be fine. I haven't found the time to really dig into
> it.
>
> I suspect that maybe the architectures doing this aren't playing by the
> rules.
> Even so, though, it doesn't change that this used to work and now doesn't.
>
It could be. I noticed aarch64 doesn't implement gdbarch_unwind_pc. But
s390 does.
It is hard to tell what is wrong given different unwinding implementations
may give correct results, even with wrong assumptions.
> Tom
>
next prev parent reply other threads:[~2020-03-26 2:47 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-20 15:58 Tom Tromey
2020-03-03 21:45 ` Tom Tromey
2020-03-05 10:21 ` Luis Machado
2020-03-05 16:56 ` Tom Tromey
2020-03-09 17:55 ` Luis Machado
2020-03-12 21:34 ` Tom Tromey
2020-03-13 13:31 ` Luis Machado
2020-03-24 21:24 ` Luis Machado
2020-03-26 1:59 ` Tom Tromey
2020-03-26 2:47 ` Luis Machado [this message]
2020-06-18 18:25 ` Andrew Burgess
2020-06-18 21:07 ` Tom Tromey
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