X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=m4%2Ftrunc.m4;h=feb9d27d576d58784a0f0ebbda5fa5a13d7b95a7;hb=d8235a667024b123ff7e89be518a7049f658e9bd;hp=58db4a19da69a6d6819ccaba1c3e2ad1cf80eb9a;hpb=ec0af5d579654eb83aafc76940412b3bc106d558;p=gnulib.git

diff --git a/m4/trunc.m4 b/m4/trunc.m4
index 58db4a19d..feb9d27d5 100644
--- a/m4/trunc.m4
+++ b/m4/trunc.m4
@@ -1,4 +1,4 @@
-# trunc.m4 serial 1
+# trunc.m4 serial 2
 dnl Copyright (C) 2007 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -7,6 +7,8 @@ dnl with or without modifications, as long as this notice is preserved.
 AC_DEFUN([gl_FUNC_TRUNC],
 [
   AC_REQUIRE([gl_MATH_H_DEFAULTS])
+  dnl Persuade glibc <math.h> to declare trunc().
+  AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
   dnl Test whether trunc() is declared.
   AC_CHECK_DECLS([trunc], , , [#include <math.h>])
   if test "$ac_cv_have_decl_trunc" = yes; then