Re: Frame lost after 'leave' and before 'ret' instruction on i386?

[Mark Kettenis <mark.kettenis@xs4all.nl>]

> Date: Fri, 16 May 2008 13:28:50 -0400
> From: Aleksandar Ristovski <aristovski@qnx.com>
> 
> Mark Kettenis wrote:
> > The compiler is supposed to give us unwind info for the function's
> > epilogue, but unfortunately GCC doesn't.  There's not much we can do
> > about it in GDB.  Fortunately it isnt an issue that users see a lot.
> > 
> 
> Out of curiosity: what is the problem with specifying epilogue? Am I
> wrong when I say that there can be only so many epilogue types
> (i.e. compiler will not generate infinite number of epilogues)?
> Therefore, only one index in a 'epilogue description table' would
> suffice...
> 
> (or am I over-simplifying?)

A compiler may reschedule instructions into the epilogue (this is what
makes writing prologue analyzers quite difficult).  I don't know
whether GCC does that or not.

I guess the real problem is that nobody has been motivated enough to
fix the problem.

Better ask questions on the GCC mailing lists though if you want an
answer that's not just a guess ;).