[Ffmpeg-devel] [PATCH] fomit-frame-pointer disable when optimizations disabled

Rich Felker dalias
Tue Jul 25 00:12:08 CEST 2006

On Mon, Jul 24, 2006 at 01:12:58PM -0500, Graham Booker wrote:
> On Jul 24, 2006, at 2:01 AM, Rich Felker wrote:
> >On Mon, Jul 24, 2006 at 09:35:45AM +1000, Nigel Pearson wrote:
> >>
> >>>I found that when -fomit-frame-pointer is enabled, it is very
> >>>difficult to trace within ffmpeg using gdb.  The following patch
> >>>modifies the configure script so that if the user disables
> >>>optimizations, then the -fomit-frame-pointer is not used.  Since
> >>>omitting the frame pointer is an optimization in my mind, I figured
> >>>this would be a good way to switch on it.
> >>
> >>1) Agree that it should only be in there if optimising
> >>(which hopefully means not debugging).
> >
> >Optimization does not imply not debugging. I've never disabled
> >optimizations for the sake of debugging, or any other purpose except
> >working around or testing for gcc bugs. Disabling -fomit-frame-pointer
> >needs to be done by --enable-debug or something like that...
> What is wrong with disabling an optimization when the user want  
> optimizations disabled?  This patch only disables -fomit-frame- 
> pointer if the configure is passed --disable-opts, and no other time.

Oh, I don't have a problem with the patch. I'm just saying that
-fomit-frame-pointer should also be disabled by --enable-debug or
whatever since debugging does not necessitate (or even recommend)
--disable-optimizations. In fact to debug the more interesting code
(with inline asm) you need optimization enabled.


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