1 files changed, 32 insertions, 2 deletions

diff --git a/lib/AST/ASTContext.cpp b/lib/AST/ASTContext.cpp
index 80ce66a017..7b61c25b1d 100644
--- a/lib/AST/ASTContext.cpp
+++ b/lib/AST/ASTContext.cpp
@@ -4368,6 +4368,29 @@ bool ASTContext::BlockRequiresCopying(QualType Ty) const {
   return false;
 }
 
+bool ASTContext::getByrefLifetime(QualType Ty,
+                              Qualifiers::ObjCLifetime &LifeTime,
+                              bool &HasByrefExtendedLayout) const {
+  
+  if (!getLangOpts().ObjC1 ||
+      getLangOpts().getGC() != LangOptions::NonGC)
+    return false;
+  
+  HasByrefExtendedLayout = false;
+  if (Ty->isAggregateType()) {
+    HasByrefExtendedLayout = true;
+    LifeTime = Qualifiers::OCL_None;
+  }
+  else if (getLangOpts().ObjCAutoRefCount)
+    LifeTime = Ty.getObjCLifetime();
+  // MRR.
+  else if (Ty->isObjCObjectPointerType() || Ty->isBlockPointerType())
+    LifeTime = Qualifiers::OCL_ExplicitNone;
+  else
+    LifeTime = Qualifiers::OCL_None;
+  return true;
+}
+
 QualType
 ASTContext::BuildByRefType(StringRef DeclName, QualType Ty) const {
   //  type = struct __Block_byref_1_X {
@@ -4377,10 +4400,13 @@ ASTContext::BuildByRefType(StringRef DeclName, QualType Ty) const {
   //    unsigned int __size;
   //    void *__copy_helper;            // as needed
   //    void *__destroy_help            // as needed
+  //    void *__byref_variable_layout;    // Extended layout info. for byref variable as needed
   //    int X;
   //  } *
 
   bool HasCopyAndDispose = BlockRequiresCopying(Ty);
+  bool HasByrefExtendedLayout;
+  Qualifiers::ObjCLifetime Lifetime;
 
   // FIXME: Move up
   SmallString<36> Name;
@@ -4398,6 +4424,7 @@ ASTContext::BuildByRefType(StringRef DeclName, QualType Ty) const {
     Int32Ty,
     getPointerType(VoidPtrTy),
     getPointerType(VoidPtrTy),
+    getPointerType(VoidPtrTy),
     Ty
   };
 
@@ -4408,12 +4435,15 @@ ASTContext::BuildByRefType(StringRef DeclName, QualType Ty) const {
     "__size",
     "__copy_helper",
     "__destroy_helper",
+    "__byref_variable_layout",
     DeclName,
   };
-
-  for (size_t i = 0; i < 7; ++i) {
+  bool ByrefKnownLifetime = getByrefLifetime(Ty, Lifetime, HasByrefExtendedLayout);
+  for (size_t i = 0; i < 8; ++i) {
     if (!HasCopyAndDispose && i >=4 && i <= 5)
       continue;
+    if ((!ByrefKnownLifetime || !HasByrefExtendedLayout) && i == 6)
+      continue;
     FieldDecl *Field = FieldDecl::Create(*this, T, SourceLocation(),
                                          SourceLocation(),
                                          &Idents.get(FieldNames[i]),