[FFmpeg-devel] [PATCH 3/3] Make opt_default(), return an error code rather than exit from the program.

[Stefano Sabatini]

On date Sunday 2010-11-07 17:13:27 +0100, Michael Niedermayer encoded:
> On Sun, Nov 07, 2010 at 04:32:45PM +0100, Stefano Sabatini wrote:
> > On date Sunday 2010-11-07 16:18:10 +0100, Michael Niedermayer encoded:
> > > On Sun, Nov 07, 2010 at 10:42:12AM +0100, Stefano Sabatini wrote:
> > > > On date Sunday 2010-11-07 01:04:49 +0100, Michael Niedermayer encoded:
> > > > > On Sun, Nov 07, 2010 at 12:53:35AM +0100, Stefano Sabatini wrote:
> > > > > > On date Sunday 2010-11-07 00:38:48 +0100, Michael Niedermayer encoded:
> > > > > > > On Sat, Nov 06, 2010 at 03:02:57PM +0100, Stefano Sabatini wrote:
> > > > > > > > This allows the program to nicely handle the error, for example
> > > > > > > > providing detailed error explanation to the user or cleaning up the
> > > > > > > > allocated resources of the program.
> > > > > > > 
> > > > > > > there is plenty of code that does not check its return value
> > > > > > > and i dont think adding checks everywhere is a good idea
> > > > > > 
> > > > > > In general returning meaningful values *is* a good idea, but I'm
> > > > > > not going to add them to all the FFmpeg codebase, but *this patch* is
> > > > > > required by the previous patches in this series, to make ffmpeg prints
> > > > > > something useful after opt_default() is called, rather than just
> > > > > > abort.
> > > > > 
> > > > > grep for opt_default and you will see there are alot of cases where the
> > > > > return value is not checked and not exiting anymore will lead to actual
> > > > > bugs
> > > > 
> > > > All but one of those uses are in opt_target() where the value is fixed
> > > 
> > > until someone changes it ...
> > > anyway, i dont strongly care about the return vs exit but i strongly object
> > > to adding 20 checks in all uses of opt_default()
> > 
> > opt_default_or_die(opt, arg)?
> 
> pass the line number and filename as argument to opt_default if you want it
> printed before exit()

opt_default() doesn't know nothing about the external context where it
is called, so it makes sense to handle the error in the callee
function (and it is not possible to change the signature of
opt_default).
-- 
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