projects/sample/autoconf/m4/huge_val.m4

   1 #
   2 # This function determins if the the HUGE_VAL macro is compilable with the
   3 # -pedantic switch or not. XCode < 2.4.1 doesn't get it right.
   4 #
   5 AC_DEFUN([AC_HUGE_VAL_CHECK],[
   6   AC_CACHE_CHECK([for HUGE_VAL sanity], [ac_cv_huge_val_sanity],[
   7     AC_LANG_PUSH([C++])
   8     ac_save_CXXFLAGS=$CXXFLAGS
   9     CXXFLAGS="$CXXFLAGS -pedantic"
  10     AC_RUN_IFELSE(
  11       AC_LANG_PROGRAM(
  12         [#include <math.h>],
  13         [double x = HUGE_VAL; return x != x; ]),
  14       [ac_cv_huge_val_sanity=yes],[ac_cv_huge_val_sanity=no],
  15       [ac_cv_huge_val_sanity=yes])
  16     CXXFLAGS=$ac_save_CXXFLAGS
  17     AC_LANG_POP([C++])
  18     ])
  19   AC_SUBST(HUGE_VAL_SANITY,$ac_cv_huge_val_sanity)
  20 ])