ansi-c++-opt: Provide option --enable-c++/--disable-c++ when possible.

[gnulib.git] / m4 / floor.m4

diff --git a/m4/floor.m4 b/m4/floor.m4
index dd1e6f6..ad6a1e4 100644 (file)
--- a/m4/floor.m4
+++ b/m4/floor.m4
@@ -1,5 +1,5 @@
-# floor.m4 serial 1
-dnl Copyright (C) 2007 Free Software Foundation, Inc.
+# floor.m4 serial 3
+dnl Copyright (C) 2007, 2009, 2010 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.
@@ -7,18 +7,19 @@ dnl with or without modifications, as long as this notice is preserved.
 AC_DEFUN([gl_FUNC_FLOOR],
 [
   dnl Test whether floor() can be used without libm.
-  FLOOR_LIBM=?
-  AC_TRY_LINK([
-     #ifndef __NO_MATH_INLINES
-     # define __NO_MATH_INLINES 1 /* for glibc */
-     #endif
-     #include <math.h>
-     double x;],
-    [x = floor(x);],
-    [FLOOR_LIBM=])
+  gl_FUNC_FLOOR_LIBS
   if test "$FLOOR_LIBM" = "?"; then
-    save_LIBS="$LIBS"
-    LIBS="$LIBS -lm"
+    FLOOR_LIBM=
+  fi
+  AC_SUBST([FLOOR_LIBM])
+])
+
+# Determines the libraries needed to get the floor() function.
+# Sets FLOOR_LIBM.
+AC_DEFUN([gl_FUNC_FLOOR_LIBS],
+[
+  gl_CACHE_VAL_SILENT([gl_cv_func_floor_libm], [
+    gl_cv_func_floor_libm=?
     AC_TRY_LINK([
        #ifndef __NO_MATH_INLINES
        # define __NO_MATH_INLINES 1 /* for glibc */
@@ -26,11 +27,20 @@ AC_DEFUN([gl_FUNC_FLOOR],
        #include <math.h>
        double x;],
       [x = floor(x);],
-      [FLOOR_LIBM="-lm"])
-    LIBS="$save_LIBS"
-  fi
-  if test "$FLOOR_LIBM" = "?"; then
-    FLOOR_LIBM=
-  fi
-  AC_SUBST([FLOOR_LIBM])
+      [gl_cv_func_floor_libm=])
+    if test "$gl_cv_func_floor_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>
+         double x;],
+        [x = floor(x);],
+        [gl_cv_func_floor_libm="-lm"])
+      LIBS="$save_LIBS"
+    fi
+  ])
+  FLOOR_LIBM="$gl_cv_func_floor_libm"
 ])