libsanitizer, Darwin : Handle missing __builtin_os_log_format.

GCC does not, currently, define __builtin_os_log_format, which
is needed by os/log.h.  Do not include that header unless the
builtin is defined (since the header errors out on the same
condition).  Provide a work-around solution to the missing API
provided via the header.

libsanitizer/ChangeLog:

	* sanitizer_common/sanitizer_mac.cpp : Check for the
	availability of __builtin_os_log_format before trying to
	include a header depending on it.
	(OS_LOG_DEFAULT): New.
	(os_log_error): Define to a fall-back using an older API.

diff --git a/libsanitizer/sanitizer_common/sanitizer_mac.cpp b/libsanitizer/sanitizer_common/sanitizer_mac.cpp
index f455856..30a94fc 100644 (file)
--- a/libsanitizer/sanitizer_common/sanitizer_mac.cpp
+++ b/libsanitizer/sanitizer_common/sanitizer_mac.cpp
@@ -70,7 +70,15 @@ extern "C" {
 #include <mach/mach_time.h>
 #include <mach/vm_statistics.h>
 #include <malloc/malloc.h>
-#include <os/log.h>
+#if defined(__has_builtin) && __has_builtin(__builtin_os_log_format)
+# include <os/log.h>
+#else
+   /* Without support for __builtin_os_log_format, fall back to the older
+      method.  */
+# define OS_LOG_DEFAULT 0
+# define os_log_error(A,B,C) \
+  asl_log(nullptr, nullptr, ASL_LEVEL_ERR, "%s", (C));
+#endif
 #include <pthread.h>
 #include <sched.h>
 #include <signal.h>