1 files changed, 12 insertions, 6 deletions
diff --git a/lib/Transforms/ObjCARC/ObjCARC.h b/lib/Transforms/ObjCARC/ObjCARC.h
index e062b66555..39670f339e 100644
--- a/lib/Transforms/ObjCARC/ObjCARC.h
+++ b/lib/Transforms/ObjCARC/ObjCARC.h
@@ -64,7 +64,8 @@ static inline bool ModuleHasARC(const Module &M) {
     M.getNamedValue("objc_copyWeak") ||
     M.getNamedValue("objc_retainedObject") ||
     M.getNamedValue("objc_unretainedObject") ||
-    M.getNamedValue("objc_unretainedPointer");
+    M.getNamedValue("objc_unretainedPointer") ||
+    M.getNamedValue("clang.arc.use");
 }
 
 /// \enum InstructionClass
@@ -89,6 +90,7 @@ enum InstructionClass {
   IC_CopyWeak,            ///< objc_copyWeak (derived)
   IC_DestroyWeak,         ///< objc_destroyWeak (derived)
   IC_StoreStrong,         ///< objc_storeStrong (derived)
+  IC_IntrinsicUser,       ///< clang.arc.use
   IC_CallOrUser,          ///< could call objc_release and/or "use" pointers
   IC_Call,                ///< could call objc_release
   IC_User,                ///< could "use" a pointer
@@ -97,6 +99,13 @@ enum InstructionClass {
 
 raw_ostream &operator<<(raw_ostream &OS, const InstructionClass Class);
 
+/// \brief Test if the given class is a kind of user.
+inline static bool IsUser(InstructionClass Class) {
+  return Class == IC_User ||
+         Class == IC_CallOrUser ||
+         Class == IC_IntrinsicUser;
+}
+
 /// \brief Test if the given class is objc_retain or equivalent.
 static inline bool IsRetain(InstructionClass Class) {
   return Class == IC_Retain ||
@@ -112,13 +121,10 @@ static inline bool IsAutorelease(InstructionClass Class) {
 /// \brief Test if the given class represents instructions which return their
 /// argument verbatim.
 static inline bool IsForwarding(InstructionClass Class) {
-  // objc_retainBlock technically doesn't always return its argument
-  // verbatim, but it doesn't matter for our purposes here.
   return Class == IC_Retain ||
          Class == IC_RetainRV ||
          Class == IC_Autorelease ||
          Class == IC_AutoreleaseRV ||
-         Class == IC_RetainBlock ||
          Class == IC_NoopCast;
 }
 
@@ -256,11 +262,11 @@ static inline Value *GetObjCArg(Value *Inst) {
   return StripPointerCastsAndObjCCalls(cast<CallInst>(Inst)->getArgOperand(0));
 }
 
-static inline bool isNullOrUndef(const Value *V) {
+static inline bool IsNullOrUndef(const Value *V) {
   return isa<ConstantPointerNull>(V) || isa<UndefValue>(V);
 }
 
-static inline bool isNoopInstruction(const Instruction *I) {
+static inline bool IsNoopInstruction(const Instruction *I) {
   return isa<BitCastInst>(I) ||
     (isa<GetElementPtrInst>(I) &&
      cast<GetElementPtrInst>(I)->hasAllZeroIndices());