isfinite, isinf, isnan tests: Avoid syntax error on MSVC 9.

[gnulib.git] / m4 / round.m4

diff --git a/m4/round.m4 b/m4/round.m4
index a95d905..e64208e 100644 (file)
--- a/m4/round.m4
+++ b/m4/round.m4
@@ -1,4 +1,4 @@
-# round.m4 serial 10
+# round.m4 serial 13
 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,
@@ -10,7 +10,7 @@ AC_DEFUN([gl_FUNC_ROUND],
   AC_REQUIRE([gl_MATH_H_DEFAULTS])
   dnl Persuade glibc <math.h> to declare round().
   AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
-  AC_CHECK_DECLS([round], , , [#include <math.h>])
+  AC_CHECK_DECLS([round], , , [[#include <math.h>]])
   if test "$ac_cv_have_decl_round" = yes; then
     gl_CHECK_MATH_LIB([ROUND_LIBM], [x = round (x);])
     if test "$ROUND_LIBM" != missing; then
@@ -69,10 +69,12 @@ int main()
 #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_round) (double) = argc ? round : dummy;
   /* Test whether round (-0.0) is -0.0.  */
-  if (signbitd (minus_zerod) && !signbitd (round (minus_zerod)))
+  if (signbitd (minus_zerod) && !signbitd (my_round (minus_zerod)))
     return 1;
   return 0;
 }
@@ -92,7 +94,7 @@ int main()
     HAVE_DECL_ROUND=0
   fi
   if test $HAVE_DECL_ROUND = 0 || test $REPLACE_ROUND = 1; then
-    AC_LIBOBJ([round])
+    dnl Find libraries needed to link lib/round.c.
     gl_FUNC_FLOOR_LIBS
     gl_FUNC_CEIL_LIBS
     ROUND_LIBM=