[geos-devel] GCC 6 build error

[Sandro Santilli]

On Wed, Mar 02, 2016 at 05:02:04PM +0200, Devrim GÜNDÜZ wrote:

> Greetings first: I'm new to list, and I'm maintaining the community RPMS for
> PostgreSQL and related software.

Thank you Devrim !

> GeOS 4.5.0 is throwing errors with GCC 6.0.0 . GCC 6 is due with Fedora 24 on
> June.

...

> ../../../include/geos/platform.h:114:2: error: #error "Can not compile without isnan function or macro"
>  #error "Can not compile without isnan function or macro"
>   ^~~~~

Could you please also report snippets from configure where
NAN is seeked for ?

This is the snippet, in configure.ac, to look for it:

  AC_LANG_PUSH([C++])
  AC_CACHE_CHECK([for isnan], ac_cv_isnan,
   [AC_TRY_LINK([#include <cmath>],
   [double x; int y; y = isnan(x);],
   ac_cv_isnan=yes,
   ac_cv_isnan=no
  )])
  if test x"$ac_cv_isnan" = x"yes"; then
    AC_DEFINE(HAVE_ISNAN, [1], [Has isnan])
  fi
  AC_LANG_POP([C++])

Best would be to file a ticket for this, btw:
https://trac.osgeo.org/geos

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