Re: HAVE_FFTW macro

[John W. Eaton]

On 03/17/2013 12:20 AM, Rik wrote:
> On 03/16/2013 12:52 AM, address@hidden wrote:
> > > Is something being overlooked there?
> > What does
> >
> >     octave_config_info ("features")
> >
> > show?  This is a list of all the HAVE_X macros, with the common "HAVE_"
> > part omitted.  On my system, it has FFTW3, but not FFTW, so it looks
> > like the testif check is wrong.
> Dan,
>
> The problem seems to be that not all #defines are captured in the new
> "features" keyword.  The definition for HAVE_FFTW is in configure.ac in the
> AH_BOTTOM macro which means it is copied to the bottom of config.h.
>
> /* Octave is currently unable to use FFTW unless both float
>     and double versions are available.  */
> #if defined (HAVE_FFTW3)&&  defined (HAVE_FFTW3F)
> #define HAVE_FFTW
> #endif
>
> I wasn't following closely what jwe did when he added the "features"
> keyword, but hopefully it is simple to fix.

OK, I see the problem now.

The new list is generated from the config.h file by 
libinterp/config-features.sh, and that script finds anything that looks 
like #define HAVE_, so it picks up the #define FFTW regardless of the 
values of HAVE_FFTW3 and HAVE_FFTW3F and adds it to the struct with a 
corresponding value of 1.  Anything that matches #undef HAVE_ is also 
inserted in the struct with a value of 0.

I checked in the following change so that we don't pick up these extra 
values that are defined conditionally.  Using a separate header file for 
AH_BOTTOM is recommended by the autoconf manual anyway.

  http://hg.savannah.gnu.org/hgweb/octave/rev/306e0ac231d0

Then I realized that FFTW would not be set to 1 in the features list 
unless it was added to the config.h file somehow, so then I made another 
change so that it is defined in config.h the same as other HAVE_X macros.

  http://hg.savannah.gnu.org/hgweb/octave/rev/5293cee91891

jwe