X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=m4%2Fcbrtf.m4;h=5c3c0f9df95987c4aaa2e6adba1675f5d8ab32ed;hb=23eecb48e39afd0d267d64d40ba6bf97aa865e13;hp=f948bd49482dbf8cc69d67000fb188566ec6529f;hpb=83f7d47767e4c9cfdbf17f2415fe9c8028ff7da8;p=gnulib.git

diff --git a/m4/cbrtf.m4 b/m4/cbrtf.m4
index f948bd494..5c3c0f9df 100644
--- a/m4/cbrtf.m4
+++ b/m4/cbrtf.m4
@@ -1,5 +1,5 @@
-# cbrtf.m4 serial 2
-dnl Copyright (C) 2012 Free Software Foundation, Inc.
+# cbrtf.m4 serial 3
+dnl Copyright (C) 2012-2013 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.
@@ -9,6 +9,9 @@ AC_DEFUN([gl_FUNC_CBRTF],
   AC_REQUIRE([gl_MATH_H_DEFAULTS])
   AC_REQUIRE([gl_FUNC_CBRT])
 
+  dnl Persuade glibc <math.h> to declare cbrtf().
+  AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+
   dnl Test whether cbrtf() exists. Assume that cbrtf(), if it exists, is
   dnl defined in the same library as cbrt().
   save_LIBS="$LIBS"