3 files changed, 20 insertions, 1 deletions
diff --git a/clang/lib/CodeGen/CGBlocks.cpp b/clang/lib/CodeGen/CGBlocks.cpp
index 1a57b3e6608..791a57e61f5 100644
--- a/clang/lib/CodeGen/CGBlocks.cpp
+++ b/clang/lib/CodeGen/CGBlocks.cpp
@@ -619,7 +619,13 @@ static void enterBlockScope(CodeGenFunction &CGF, BlockDecl *block) {
 
     // Block captures count as local values and have imprecise semantics.
     // They also can't be arrays, so need to worry about that.
-    if (dtorKind == QualType::DK_objc_strong_lifetime) {
+    //
+    // For const-qualified captures, emit clang.arc.use to ensure the captured
+    // object doesn't get released while we are still depending on its validity
+    // within the block.
+    if (VT.isConstQualified() && VT.getObjCLifetime() == Qualifiers::OCL_Strong)
+      destroyer = CodeGenFunction::emitARCIntrinsicUse;
+    else if (dtorKind == QualType::DK_objc_strong_lifetime) {
       destroyer = CodeGenFunction::destroyARCStrongImprecise;
     } else {
       destroyer = CGF.getDestroyer(dtorKind);
@@ -866,6 +872,12 @@ llvm::Value *CodeGenFunction::EmitBlockLiteral(const CGBlockInfo &blockInfo) {
     } else if (type->isReferenceType()) {
       Builder.CreateStore(src.getPointer(), blockField);
 
+    // If type is const-qualified, copy the value into the block field.
+    } else if (type.isConstQualified() &&
+               type.getObjCLifetime() == Qualifiers::OCL_Strong) {
+      llvm::Value *value = Builder.CreateLoad(src, "captured");
+      Builder.CreateStore(value, blockField);
+
     // If this is an ARC __strong block-pointer variable, don't do a
     // block copy.
     //
diff --git a/clang/lib/CodeGen/CGObjC.cpp b/clang/lib/CodeGen/CGObjC.cpp
index 76e7df861f7..f4fbab3c2b8 100644
--- a/clang/lib/CodeGen/CGObjC.cpp
+++ b/clang/lib/CodeGen/CGObjC.cpp
@@ -2415,6 +2415,12 @@ void CodeGenFunction::destroyARCWeak(CodeGenFunction &CGF,
   CGF.EmitARCDestroyWeak(addr);
 }
 
+void CodeGenFunction::emitARCIntrinsicUse(CodeGenFunction &CGF, Address addr,
+                                          QualType type) {
+  llvm::Value *value = CGF.Builder.CreateLoad(addr);
+  CGF.EmitARCIntrinsicUse(value);
+}
+
 namespace {
   struct CallObjCAutoreleasePoolObject final : EHScopeStack::Cleanup {
     llvm::Value *Token;
diff --git a/clang/lib/CodeGen/CodeGenFunction.h b/clang/lib/CodeGen/CodeGenFunction.h
index 1ded824ba5b..f9bc4a1bc2d 100644
--- a/clang/lib/CodeGen/CodeGenFunction.h
+++ b/clang/lib/CodeGen/CodeGenFunction.h
@@ -3369,6 +3369,7 @@ public:
   static Destroyer destroyARCStrongImprecise;
   static Destroyer destroyARCStrongPrecise;
   static Destroyer destroyARCWeak;
+  static Destroyer emitARCIntrinsicUse;
 
   void EmitObjCAutoreleasePoolPop(llvm::Value *Ptr); 
   llvm::Value *EmitObjCAutoreleasePoolPush();