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Date: Tue, 08 Apr 2008 16:56:34 -0700
From: Brian Dessent <brian AT dessent DOT net>
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Subject: Re: Question on gdb and ?? And also Frame did not save PC message
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Brian Keener wrote:

> As to the second part of my question - is there a way to determine what
> sources/debug info I still need to get around the ?? Or is that just a
> matter of tracing from the sources I can see to find what it is bing
> called next?

Most of those frames with ?? are totally bogus -- there is not actually
a frame at 0x00000028 or 0x00000001 etc., it's just that gdb got
confused trying to unwind the stack and did its best.  One problem is
that Cygwin uses these sigfe/sigfe wrappers around most syscalls,
another is that gdb doesn't have debug info for system DLLs and if they
use FPO there's no way to unwind through them.

> Also when using the new gdb is the message about
> "Frame did not save PC message" expected or is that an indication of some
> limit exceeded or something else.

It's just another an indication that gdb is having trouble unwinding, as
with system DLLs with FPO enabled.

Brian

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