make optional pointer really optional

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@29904 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/System/MappedFile.h b/include/llvm/System/MappedFile.h
index 8cd926bc14362e8ecb8c429e5a94a62bb8864211..f82d6fe9429ea947a0c5c96d9441568252c4536e 100644 (file)
--- a/include/llvm/System/MappedFile.h
+++ b/include/llvm/System/MappedFile.h
@@ -123,7 +123,7 @@ namespace sys {
     /// occurred.
     /// @brief Map the file into memory.
     void* map(
-      std::string* ErrMsg ///< Optional error string pointer
+      std::string* ErrMsg = 0///< Optional error string pointer
     );
 
     /// This method causes the size of the file, and consequently the size