2 files changed, 9 insertions, 0 deletions
diff --git a/lib/Driver/ToolChains.h b/lib/Driver/ToolChains.h
index 8ea466af77..2005d9654c 100644
--- a/lib/Driver/ToolChains.h
+++ b/lib/Driver/ToolChains.h
@@ -318,6 +318,10 @@ public:
     return true;
   }
 
+  virtual bool IsEncodeExtendedBlockSignatureDefault() const {
+    return true;
+  }
+  
   virtual bool IsObjCNonFragileABIDefault() const {
     // Non-fragile ABI is default for everything but i386.
     return getTriple().getArch() != llvm::Triple::x86;
diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index b1e450d21c..4dea717f98 100644
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -2727,6 +2727,11 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
     CmdArgs.push_back("-fobjc-default-synthesize-properties");
   }
 
+  // -fencode-extended-block-signature=1 is default.
+  if (getToolChain().IsEncodeExtendedBlockSignatureDefault()) {
+    CmdArgs.push_back("-fencode-extended-block-signature");
+  }
+  
   // Allow -fno-objc-arr to trump -fobjc-arr/-fobjc-arc.
   // NOTE: This logic is duplicated in ToolChains.cpp.
   bool ARC = isObjCAutoRefCount(Args);