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From: Richard Henderson <rth@redhat.com>
To: Jim Blandy <jimb@redhat.com>
Cc: Andrew Cagney <ac131313@redhat.com>,
	Mark Kettenis <kettenis@chello.nl>,
	mludvig@suse.cz, gdb@sources.redhat.com,
	Alexandre Oliva <aoliva@redhat.com>
Subject: Re: dwarf-frame.c question
Date: Tue, 03 Jun 2003 15:58:00 -0000	[thread overview]
Message-ID: <20030603155646.GA19391@redhat.com> (raw)
In-Reply-To: <vt2fzmrpt9b.fsf@zenia.red-bean.com>

On Tue, Jun 03, 2003 at 01:30:56AM -0500, Jim Blandy wrote:
> Since we're unwinding a frame which will never really be unwound, we
> can have that do anything we want.  So, if a function never returns,
> why not have the compiler emit CFI that restores the state just
> *before* the call insn was executed, not after it returns?  The
> unwound PC would point at the call insn itself.

Hmm.  You mean that the unwind info for "abort" itself
would change to say that the return address was something
other than it really is?

Certainly this is possible.  If the function has the
noreturn attribute GCC could frob the return address
with DW_CFA_expression.

Does this have any other adverse side effects though?

How about the fact that abort is often written in assembly
language in libc, and so may not have any specific unwind
information at all?


r~

  reply	other threads:[~2003-06-03 15:58 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2003-05-27 15:19 Michal Ludvig
2003-05-29 15:44 ` Mark Kettenis
2003-05-29 19:54   ` Andrew Cagney
2003-05-29 22:22     ` Mark Kettenis
2003-05-29 22:43       ` Michal Ludvig
2003-05-29 23:13       ` Andrew Cagney
2003-05-30  1:34         ` Daniel Jacobowitz
2003-05-30 20:21         ` Jim Blandy
2003-05-30 20:21         ` Jim Blandy
2003-05-30 20:32           ` Andrew Cagney
2003-06-03  0:04             ` Jim Blandy
2003-06-03  5:47               ` Richard Henderson
2003-06-03  6:32                 ` Jim Blandy
2003-06-03 15:58                   ` Richard Henderson [this message]
2003-06-03 17:38                     ` Richard Henderson
2003-06-03 20:12                   ` Alexandre Oliva
2003-05-30 20:44           ` Alexandre Oliva
2003-06-01  5:59 Richard Henderson
2003-06-01 10:00 ` Mark Kettenis
2003-06-02 20:34   ` Richard Henderson

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