mac: Suppress partial availability warnings.

util/stdlib/strnlen.cc

Index: util/stdlib/strnlen.cc
diff --git a/util/stdlib/strnlen.cc b/util/stdlib/strnlen.cc
index b17796bb8e439152dfd9d37c888bb6ee1cd7554d..280d2e6e5b9ff00505c953f8d5a28997418a9e65 100644
--- a/util/stdlib/strnlen.cc
+++ b/util/stdlib/strnlen.cc
@@ -14,6 +14,14 @@
 
 #include "util/stdlib/strnlen.h"
 
+#if defined(OS_MACOSX) && \
+    MAC_OS_X_VERSION_MIN_REQUIRED < MAC_OS_X_VERSION_10_7 && \
+    MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_7
+// Forward declare a method only available on OSX 10.7+ so that

[Mark Mentovai, 2015/04/29 00:33:52]

There’s nothing really “forward” about this, it’s just your own declaration.

[erikchen, 2015/04/30 00:34:42]

Right. Updated the comment.

+// -Wpartial-availability does not emit a warning.
+size_t strnlen(const char*, size_t);

[Mark Mentovai, 2015/04/29 00:33:52]

The parameters should be named, and this ought to be in an extern "C" block.
(Did you test this?)

[erikchen, 2015/04/30 00:34:42]

I've done as you suggested. The extern "C" seems to have no effect on the final
product. (tests passes both with and without, dyldinfo shows the same symbol as
well)

+#endif
+
 namespace crashpad {
 
 #if defined(OS_MACOSX) && MAC_OS_X_VERSION_MIN_REQUIRED < MAC_OS_X_VERSION_10_7

[Mark Mentovai, 2015/04/29 00:33:52]

We should be sharing this #ifdef. You can move it outside of namespace crashpad.

[erikchen, 2015/04/30 00:34:42]

Done.