2 files changed, 5 insertions, 4 deletions

diff --git a/include/fortify-headers.h b/include/fortify-headers.h
index 3eaed7c..bc7bf00 100644
--- a/include/fortify-headers.h
+++ b/include/fortify-headers.h
@@ -106,9 +106,9 @@
 #define __diagnose_as_builtin(...)
 #endif
 
-#if __has_attribute (__diagnose_if)
-#define __warning_if(cond, msg) __attribute__ ((__diagnose_if (cond, msg, "warning")))
-#define __error_if(cond, msg) __attribute__ ((__diagnose_if (cond, msg, "error")))
+#if __has_attribute (diagnose_if)
+#define __warning_if(cond, msg) __attribute__ ((diagnose_if (cond, msg, "warning")))
+#define __error_if(cond, msg) __attribute__ ((diagnose_if (cond, msg, "error")))
 #else
 #define __warning_if(cond, msg)
 #define __error_if(cond, msg)
diff --git a/include/string.h b/include/string.h
index be13cb4..010b7f2 100644
--- a/include/string.h
+++ b/include/string.h
@@ -43,6 +43,7 @@ __access(read_only, 2, 3)
 __diagnose_as_builtin(__builtin_memcpy, 1, 2, 3)
 _FORTIFY_FN(memcpy) void *memcpy(void * _FORTIFY_POS0 __od,
                                  const void * _FORTIFY_POS0 __os, size_t __n)
+__error_if((__bos(__od, 0) < __n), "'memcpy' called with `n` bigger than the size of `d`.")
 {
         size_t __bd = __bos(__od, 0);
         size_t __bs = __bos(__os, 0);
@@ -72,8 +73,8 @@ _FORTIFY_FN(memmove) void *memmove(void * _FORTIFY_POS0 __d,
 
 __access(write_only, 1, 3)
 __diagnose_as_builtin(__builtin_memset, 1, 2, 3)
-__warning_if(__c != 0 && __n == 0, "'memset' will set `0` bytes; did you invert the arguments?")
 _FORTIFY_FN(memset) void *memset(void * _FORTIFY_POS0 __d, int __c, size_t __n)
+__warning_if(__c != 0 && __n == 0, "'memset' will set `0` bytes; did you invert the arguments?")
 {
         size_t __b = __bos(__d, 0);