manywarnings: drop -Wunsuffixed-float-constants

[gnulib.git] / m4 / truncf.m4

diff --git a/m4/truncf.m4 b/m4/truncf.m4
index 3920fcd..346f0c8 100644 (file)
--- a/m4/truncf.m4
+++ b/m4/truncf.m4
@@ -1,4 +1,4 @@
-# truncf.m4 serial 5
+# truncf.m4 serial 8
 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,
@@ -11,7 +11,7 @@ AC_DEFUN([gl_FUNC_TRUNCF],
   dnl Persuade glibc <math.h> to declare truncf().
   AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
   dnl Test whether truncf() is declared.
-  AC_CHECK_DECLS([truncf], , , [#include <math.h>])
+  AC_CHECK_DECLS([truncf], , , [[#include <math.h>]])
   if test "$ac_cv_have_decl_truncf" = yes; then
     dnl Test whether truncf() can be used without libm.
     TRUNCF_LIBM=?
@@ -56,10 +56,12 @@ AC_DEFUN([gl_FUNC_TRUNCF],
 #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_truncf) (float) = argc ? truncf : dummy;
   /* Test whether truncf (-0.0f) is -0.0f.  */
-  if (signbitf (minus_zerof) && !signbitf (truncf (minus_zerof)))
+  if (signbitf (minus_zerof) && !signbitf (my_truncf (minus_zerof)))
     return 1;
   return 0;
 }