Update Gnulib to v0.0-5874-g7170ee0.

[bpt/guile.git] / m4 / trunc.m4

diff --git a/m4/trunc.m4 b/m4/trunc.m4
index 953f5b1..6231101 100644 (file)
--- a/m4/trunc.m4
+++ b/m4/trunc.m4
@@ -1,4 +1,4 @@
-# trunc.m4 serial 6
+# trunc.m4 serial 7
 dnl Copyright (C) 2007, 2010-2011 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -56,10 +56,12 @@ AC_DEFUN([gl_FUNC_TRUNC],
 #include <math.h>
 ]gl_DOUBLE_MINUS_ZERO_CODE[
 ]gl_DOUBLE_SIGNBIT_CODE[
-int main()
+static double dummy (double f) { return 0; }
+int main (int argc, char *argv[])
 {
+  double (*my_trunc) (double) = argc ? trunc : dummy;
   /* Test whether trunc (-0.0) is -0.0.  */
-  if (signbitd (minus_zerod) && !signbitd (trunc (minus_zerod)))
+  if (signbitd (minus_zerod) && !signbitd (my_trunc (minus_zerod)))
     return 1;
   return 0;
 }