Enable ISO C11 APIs when building libc, even with an older compiler.

Otherwise, the prototypes for timespec_get() and aligned_alloc()
are not visible.  OK guenther@

diff --git a/lib/libc/include/namespace.h b/lib/libc/include/namespace.h
index b42c00e..8503de4 100644 (file)
--- a/lib/libc/include/namespace.h
+++ b/lib/libc/include/namespace.h
@@ -1,4 +1,4 @@
-/*     $OpenBSD: namespace.h,v 1.15 2019/11/25 22:57:28 guenther Exp $ */
+/*     $OpenBSD: namespace.h,v 1.16 2023/10/29 14:26:13 millert Exp $  */
 
 #ifndef _LIBC_NAMESPACE_H_
 #define _LIBC_NAMESPACE_H_
@@ -19,6 +19,14 @@
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
+/*
+ * ISO C11 or higher is required to build libc.
+ * This must come _before_ sys/cdefs.h is included.
+ */
+#if !defined(__STDC_VERSION__) || __STDC_VERSION__ < 201112
+#define _ISOC11_SOURCE 1
+#endif
+
 /*
  * For explanations of how to use these, see README
  * For explanations of why we use them and how they work, see DETAILS