-# logb.m4 serial 1
-dnl Copyright (C) 2010 Free Software Foundation, Inc.
+# logb.m4 serial 4
+dnl Copyright (C) 2010-2012 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
dnl with or without modifications, as long as this notice is preserved.
[
AC_REQUIRE([gl_MATH_H_DEFAULTS])
dnl Test whether logb() is declared.
- AC_CHECK_DECLS([logb], , , [#include <math.h>])
+ AC_CHECK_DECLS([logb], , , [[#include <math.h>]])
if test "$ac_cv_have_decl_logb" != yes; then
HAVE_DECL_LOGB=0
fi
dnl Test whether logb() can be used without libm.
LOGB_LIBM=?
- AC_TRY_LINK([
- #ifndef __NO_MATH_INLINES
- # define __NO_MATH_INLINES 1 /* for glibc */
- #endif
- #include <math.h>
- extern double logb (double x);
- double x;],
- [x = logb(x);],
+ AC_LINK_IFELSE(
+ [AC_LANG_PROGRAM(
+ [[#ifndef __NO_MATH_INLINES
+ # define __NO_MATH_INLINES 1 /* for glibc */
+ #endif
+ #include <math.h>
+ extern
+ #ifdef __cplusplus
+ "C"
+ #endif
+ double logb (double x);
+ double x;]],
+ [[x = logb(x);]])],
[LOGB_LIBM=])
if test "$LOGB_LIBM" = "?"; then
save_LIBS="$LIBS"
LIBS="$LIBS -lm"
- AC_TRY_LINK([
- #ifndef __NO_MATH_INLINES
- # define __NO_MATH_INLINES 1 /* for glibc */
- #endif
- #include <math.h>
- extern double logb (double x);
- double x;],
- [x = logb(x);],
+ AC_LINK_IFELSE(
+ [AC_LANG_PROGRAM(
+ [[#ifndef __NO_MATH_INLINES
+ # define __NO_MATH_INLINES 1 /* for glibc */
+ #endif
+ #include <math.h>
+ extern
+ #ifdef __cplusplus
+ "C"
+ #endif
+ double logb (double x);
+ double x;]],
+ [[x = logb(x);]])],
[LOGB_LIBM="-lm"])
LIBS="$save_LIBS"
fi