Don't depend on undefined macros being 0, there are options for the

preprocessor to warn about it.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@147466 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Headers/unwind.h b/lib/Headers/unwind.h
index 66ede93e6b9626b25ca6fa5009ed731318d6bd5c..773f3e809334b27a91693aa9987072e6145576b9 100644 (file)
--- a/lib/Headers/unwind.h
+++ b/lib/Headers/unwind.h
@@ -23,7 +23,8 @@
 
 /* See "Data Definitions for libgcc_s" in the Linux Standard Base.*/
 
-#if __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ >=  1070
+#if defined(__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__) && \
+    __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ >=  1070
 /* Starting in OS X Lion the SDK includes a unwind.h. We should just use it. */
 #include_next <unwind.h>
 #else