math: Ensure declarations of math functions.

[gnulib.git] / m4 / rintl.m4

diff --git a/m4/rintl.m4 b/m4/rintl.m4
index 63e7665..f9d70c5 100644 (file)
--- a/m4/rintl.m4
+++ b/m4/rintl.m4
@@ -1,4 +1,4 @@
-# rintl.m4 serial 3
+# rintl.m4 serial 4
 dnl Copyright (C) 2011-2012 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -9,6 +9,9 @@ AC_DEFUN([gl_FUNC_RINTL],
   AC_REQUIRE([gl_MATH_H_DEFAULTS])
   AC_REQUIRE([gl_LONG_DOUBLE_VS_DOUBLE])
 
+  dnl Persuade glibc <math.h> to declare rintl().
+  AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+
   dnl Determine RINTL_LIBM.
   gl_MATHFUNC([rintl], [long double], [(long double)])
   if test $gl_cv_func_rintl_no_libm = no \