add port io functions to sys/io.h

[oweals/musl.git] / include / errno.h

diff --git a/include/errno.h b/include/errno.h
index d9c2c9c73099a5161c3d6568f41a3f8e000ce752..9e1e3202b79dcd9d024a52d76e8b5ed99cafe6ad 100644 (file)
--- a/include/errno.h
+++ b/include/errno.h
@@ -7,7 +7,10 @@ extern "C" {
 
 #include <bits/errno.h>
 
-extern int *__errno_location(void);
+#ifdef __GNUC__
+__attribute__((const))
+#endif
+int *__errno_location(void);
 #define errno (*__errno_location())
 
 #ifdef __cplusplus