[FFmpeg-devel] [PATCH] Implement CPP condition check support in configure

[Stefano Sabatini]

On date Wednesday 2008-09-24 19:55:20 +0100, M?ns Rullg?rd encoded:
> Stefano Sabatini <stefano.sabatini-lala at poste.it> writes:
[...]
> > Index: configure
> > ===================================================================
> > --- configure	(revision 15400)
> > +++ configure	(working copy)
> > @@ -521,6 +521,24 @@
> >  EOF
> >  }
> >  
> > +check_cpp_condition(){
> > +    log check_cpp_condition "$@"
> > +    headers=$1
> > +    condition=$2
> > +    shift 3
> 
> shift 2

Fixed.

> > +    incs=""
> > +    for hdr in $headers; do
> > +        incs="$incs
> > +#include <$hdr>"
> > +    done
> > +    check_cpp <<EOF
> > +$incs
> > +#if !($condition)
> > +#error "unsatisfied condition: $condition"
> > +#endif
> > +EOF
> > +}
> 
> This is more or less what I had in mind.
> 
> >  check_lib(){
> >      log check_lib "$@"
> >      header="$1"
> > @@ -608,6 +626,16 @@
> >      check_lib2 "$headers" $func "$@" || die "ERROR: $name not found"
> >  }
> >  
> > +require3(){
> > +    name="$1"
> > +    headers="$2"
> > +    func="$3"
> > +    cpp_condition="$4"
> > +    shift 4
> > +    check_lib2 "$headers" $func "$@" || die "ERROR: $name not found"
> > +    check_cpp_condition "$headers" "$cpp_condition" "$@" || die "ERROR: $name does not satisfies CPP condition: $cpp_condition"
> > +}
> 
> I'm not entirely happy with this.

I think I improved it a little, please check it now.

> >  check_foo_config(){
> >      cfg=$1
> >      pkg=$2
> > @@ -1714,7 +1742,7 @@
> >                          && require libschroedinger schroedinger/schro.h schro_init $(pkg-config --libs schroedinger-1.0)
> >  enabled libtheora  && require  libtheora theora/theora.h theora_info_init -ltheora -logg
> >  enabled libvorbis  && require  libvorbis vorbis/vorbisenc.h vorbis_info_init -lvorbisenc -lvorbis -logg
> > -enabled libx264    && require  x264 x264.h x264_encoder_open -lx264 -lm
> > +enabled libx264    && require3 x264 "stdint.h x264.h" x264_encoder_open "X264_BUILD >= 63" -lx264 -lm
> 
> No need to include stdint.h.  The preprocessor doesn't care if there
> are undefined things in x264.h.

It is needed if using check_lib2, changed require3 which now uses
check_lib.
 
> Now I'm still not convinced we need to check the x264 version.  We
> have always required a reasonably recent version, and have had few, if
> any, complaints in the past.

I remember at least two users on ffmpeg-user hitting their head on
this.

Also in principle I think programs should strive hard to provide clear
and precise error messages, I also like the idea of me trying to
compile ffmpeg 20 years from now on an old machine and still get
ffmpeg behave as a nice guy and say me what the problem is with my
configuration (for that time I think I'll have forgotten that I need
latest libx264 ;-)).
 
Regards.
-- 
FFmpeg = Foolish & Frenzy Martial Powered Erudite God
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