configure.in: Define _GNU_SOURCE only when using the GNU C Library.

	* configure.in: Define _GNU_SOURCE only when using the GNU C
	Library.
        * configure: Regenerated.
        * config.in: Regenerated.

From-SVN: r36485

gcc/ChangeLog

+2000-09-18  Andreas Jaeger  <aj@suse.de>
+
+	* configure.in: Define _GNU_SOURCE only when using the GNU C
+	Library.
+        * configure: Regenerated.
+        * config.in: Regenerated.
+
 2000-09-17  Mark Mitchell  <mark@codesourcery.com>
 
 	* cppinit.c (cpp_init): Don't use ANSI prototypes.

gcc/config.in

@@ -328,6 +328,9 @@
    character sets for source code. */
 #undef MULTIBYTE_CHARS
 
+/* Always define this when using the GNU C Library */
+#undef _GNU_SOURCE
+
 /* Always define this */
 #undef _GNU_SOURCE
 

gcc/configure.in

@@ -395,8 +395,19 @@ else
     AC_MSG_RESULT(no)
 fi
 
-# Define _GNU_SOURCE, since this is a GNU program.
-AC_DEFINE(_GNU_SOURCE, 1, [Always define this])
+AC_MSG_CHECKING(for GNU C library)
+AC_CACHE_VAL(gcc_cv_glibc,
+[AC_TRY_COMPILE(
+  [#include <features.h>],[
+#if ! (defined __GLIBC__ || defined __GNU_LIBRARY__)
+#error Not a GNU C library system
+#endif], 
+  [gcc_cv_glibc=yes], 
+  gcc_cv_glibc=no)])
+AC_MSG_RESULT($gcc_cv_glibc)
+if test "gcc_cv_glibc" = "yes"; then
+  AC_DEFINE(_GNU_SOURCE, 1, [Always define this when using the GNU C Library])
+fi
 
 AC_C_INLINE