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From: Andy Wingo <wingo@igalia.com>
To: Doug Evans <dje@google.com>
Cc: Alexander Smundak <asmundak@google.com>,
	 gdb-patches <gdb-patches@sourceware.org>
Subject: Re: Unwinding through multiple stacks
Date: Wed, 25 Mar 2015 07:35:00 -0000	[thread overview]
Message-ID: <87y4ml1qcy.fsf@igalia.com> (raw)
In-Reply-To: <CADPb22ROU+XoYhNhRqLWJycC43nuk9m15GEE3o7f_y_Oie8EzQ@mail.gmail.com>	(Doug Evans's message of "Tue, 24 Mar 2015 17:00:07 -0700")

Hi,

On Wed 25 Mar 2015 01:00, Doug Evans <dje@google.com> writes:

> A topic came up on #gdb that the current patches don't cover.
> What if the frame we're trying to unwind through has a different
> stack?

I was wondering about this too.  IIUC this check from GDB isn't a
fundamental limitation -- it's just a convenience for the user, that we
don't keep trying to compute outer frames for what looks to be a corrupt
stack.

In these cases I would have the unwinder mark the frame as not needing
an UNWIND_INNER_ID check.  Having the check by default is still useful
IMO.  How about

  (unwind-info-set-discontiguous! unwind-info #t)

or something.  That would eventually cause the frame_id to have a
"discontiguous" bitfield marked as 1.

To me it seems appropriate for a followup patch.  WDYT?

Andy


      reply	other threads:[~2015-03-25  7:35 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-03-25  0:00 Doug Evans
2015-03-25  7:35 ` Andy Wingo [this message]

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