2 files changed, 10 insertions, 6 deletions
diff --git a/lib/Basic/Diagnostic.cpp b/lib/Basic/Diagnostic.cpp
index f9e1d2bda3..0f8f314f15 100644
--- a/lib/Basic/Diagnostic.cpp
+++ b/lib/Basic/Diagnostic.cpp
@@ -113,6 +113,7 @@ Diagnostic::Diagnostic(DiagnosticClient *client) : Client(client) {
   WarningsAsErrors = false;
   WarnOnExtensions = false;
   ErrorOnExtensions = false;
+  SuppressSystemWarnings = false;
   // Clear all mappings, setting them to MAP_DEFAULT.
   memset(DiagMappings, 0, sizeof(DiagMappings));
   
@@ -224,7 +225,8 @@ void Diagnostic::Report(DiagnosticClient* C,
   // have to check on the original DiagID here, because we also want to
   // ignore extensions and warnings in -Werror and -pedantic-errors modes,
   // which *map* warnings/extensions to errors.
-  if (DiagID < diag::NUM_BUILTIN_DIAGNOSTICS &&
+  if (SuppressSystemWarnings &&
+      DiagID < diag::NUM_BUILTIN_DIAGNOSTICS &&
       getBuiltinDiagClass(DiagID) != ERROR &&
       Loc.isValid() && Loc.isFileID() && Loc.isInSystemHeader())
     return;
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index 726372356e..2f4350766a 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -276,11 +276,13 @@ TypedefDecl *Sema::MergeTypeDefDecl(TypedefDecl *New, Decl *OldD) {
   // *either* declaration is in a system header. The code below implements
   // this adhoc compatibility rule. FIXME: The following code will not
   // work properly when compiling ".i" files (containing preprocessed output).
-  SourceManager &SrcMgr = Context.getSourceManager();
-  if (SrcMgr.isInSystemHeader(Old->getLocation()))
-    return New;
-  if (SrcMgr.isInSystemHeader(New->getLocation()))
-    return New;
+  if (PP.getDiagnostics().getSuppressSystemWarnings()) {
+    SourceManager &SrcMgr = Context.getSourceManager();
+    if (SrcMgr.isInSystemHeader(Old->getLocation()))
+      return New;
+    if (SrcMgr.isInSystemHeader(New->getLocation()))
+      return New;
+  }
 
   Diag(New->getLocation(), diag::err_redefinition, New->getName());
   Diag(Old->getLocation(), diag::err_previous_definition);