freopen: Don't crash if the filename argument is NULL.

[gnulib.git] / m4 / ceilf.m4

diff --git a/m4/ceilf.m4 b/m4/ceilf.m4
index 7b9bbcc..8b74a6d 100644 (file)
--- a/m4/ceilf.m4
+++ b/m4/ceilf.m4
@@ -1,5 +1,5 @@
-# ceilf.m4 serial 8
-dnl Copyright (C) 2007, 2009-2010 Free Software Foundation, Inc.
+# ceilf.m4 serial 11
+dnl Copyright (C) 2007, 2009-2011 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.
@@ -35,12 +35,18 @@ AC_DEFUN([gl_FUNC_CEILF],
 #include <math.h>
 ]gl_FLOAT_MINUS_ZERO_CODE[
 ]gl_FLOAT_SIGNBIT_CODE[
-int main()
+static float dummy (float f) { return 0; }
+int main (int argc, char *argv[])
 {
+  float (*my_ceilf) (float) = argc ? ceilf : dummy;
+  int result = 0;
   /* Test whether ceilf (-0.0f) is -0.0f.  */
-  if (signbitf (minus_zerof) && !signbitf (ceilf (minus_zerof)))
-    return 1;
-  return 0;
+  if (signbitf (minus_zerof) && !signbitf (my_ceilf (minus_zerof)))
+    result |= 1;
+  /* Test whether ceilf (-0.3f) is -0.0f.  */
+  if (signbitf (-0.3f) && !signbitf (my_ceilf (-0.3f)))
+    result |= 2;
+  return result;
 }
               ]])],
               [gl_cv_func_ceilf_ieee=yes],
@@ -58,7 +64,7 @@ int main()
     HAVE_DECL_CEILF=0
   fi
   if test $HAVE_DECL_CEILF = 0 || test $REPLACE_CEILF = 1; then
-    AC_LIBOBJ([ceilf])
+    dnl No libraries are needed to link lib/ceilf.c.
     CEILF_LIBM=
   fi
   AC_SUBST([CEILF_LIBM])