+ AC_REQUIRE([AC_C_INLINE])
+
+ AC_CACHE_CHECK([whether NAN macro works], [gl_cv_header_math_nan_works],
+ [AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[@%:@include <math.h>]],
+ [[/* Solaris 10 has a broken definition of NAN. Other platforms
+ fail to provide NAN, or provide it only in C99 mode; this
+ test only needs to fail when NAN is provided but wrong. */
+ float f = 1.0f;
+#ifdef NAN
+ f = NAN;
+#endif
+ return f == 0;]])],
+ [gl_cv_header_math_nan_works=yes],
+ [gl_cv_header_math_nan_works=no])])
+ if test $gl_cv_header_math_nan_works = no; then
+ REPLACE_NAN=1
+ fi
+ AC_CACHE_CHECK([whether HUGE_VAL works], [gl_cv_header_math_huge_val_works],
+ [AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[@%:@include <math.h>]],
+ [[/* Solaris 10 has a broken definition of HUGE_VAL. */
+ double d = HUGE_VAL;
+ return d == 0;]])],
+ [gl_cv_header_math_huge_val_works=yes],
+ [gl_cv_header_math_huge_val_works=no])])
+ if test $gl_cv_header_math_huge_val_works = no; then
+ REPLACE_HUGE_VAL=1
+ fi
+
+ dnl Check for declarations of anything we want to poison if the
+ dnl corresponding gnulib module is not in use.
+ gl_WARN_ON_USE_PREPARE([[#include <math.h>
+ ]], [acosl asinl atanl ceilf ceill cosl expl floorf floorl frexpl
+ ldexpl logb logl round roundf roundl sinl sqrtl tanl trunc truncf truncl])