# HG changeset patch
# User Jim Meyering <jim@meyering.net>
# Date 960020634 0
# Node ID 7c8ce8117a09905a4edbd4afa9d904fccb306736
# Parent  3ace7a449eb5c7b660ab6bdd5a22a33b18039407
New file.  From Bruno Haible.

diff --git a/m4/glibc21.m4 b/m4/glibc21.m4
new file mode 100644
--- /dev/null
+++ b/m4/glibc21.m4
@@ -0,0 +1,25 @@
+#serial 1
+
+# Test for the GNU C Library, version 2.1 or newer.
+# From Bruno Haible.
+
+AC_DEFUN(jm_GLIBC21,
+  [
+    AC_CACHE_CHECK(whether we are using the GNU C Library 2.1 or newer,
+      ac_cv_gnu_library_2_1,
+      [AC_EGREP_CPP([Lucky GNU user],
+	[
+#include <features.h>
+#ifdef __GNU_LIBRARY__
+ #if (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 1) || (__GLIBC__ > 2)
+  Lucky GNU user
+ #endif
+#endif
+	],
+	ac_cv_gnu_library_2_1=yes,
+	ac_cv_gnu_library_2_1=no)
+      ]
+    )
+    AC_DEFINE_UNQUOTED(GLIBC21,$ac_cv_gnu_library_2_1)
+  ]
+)