[PATCH] D41050: Fix over-release of return value of lambda implicitly converted to block

[Dan Zimmerman via Phabricator via cfe-commits]

danzimm updated this revision to Diff 126628.
danzimm added a comment.

Call objc_retainAutoreleasedReturnValue after invoking a wrapped lambda


Repository:
  rC Clang

https://reviews.llvm.org/D41050

Files:
  lib/CodeGen/CGBlocks.cpp
  lib/CodeGen/CGClass.cpp
  test/CodeGenObjCXX/arc-forwarded-lambda-call.mm


Index: test/CodeGenObjCXX/arc-forwarded-lambda-call.mm
===================================================================
--- /dev/null
+++ test/CodeGenObjCXX/arc-forwarded-lambda-call.mm
@@ -0,0 +1,21 @@
+// RUN: %clang_cc1 -triple x86_64-apple-macosx10.12.0 -emit-llvm -fblocks -fobjc-arc -fobjc-runtime-has-weak -std=c++11 -O2 -o - %s | FileCheck %s
+
+void test0(id x) {
+  extern void test0_helper(id (^)(void));
+  test0_helper([=]() { return x; });
+  // CHECK-LABEL: define internal i8* @___Z5test0P11objc_object_block_invoke
+  // CHECK: {{%.*}} = tail call i8* @objc_retain(i8* [[T0:%.*]])
+  // CHECK-NEXT: {{%.*}} = tail call i8* @objc_autoreleaseReturnValue(i8* [[T0]])
+  // CHECK-NEXT: ret i8* [[T0]]
+}
+
+id test1_rv;
+
+void test1() {
+  extern void test1_helper(id (*)(void));
+  test1_helper([](){ return test1_rv; });
+  // CHECK-LABEL: define internal i8* @"_ZZ5test1vEN3$_18__invokeEv"
+  // CHECK: {{%.*}} = tail call i8* @objc_retain(i8* [[T0:%.*]])
+  // CHECK-NEXT: {{%.*}} = tail call i8* @objc_autoreleaseReturnValue(i8* [[T0]])
+  // CHECK-NEXT: ret i8* [[T0]]
+}
Index: lib/CodeGen/CGClass.cpp
===================================================================
--- lib/CodeGen/CGClass.cpp
+++ lib/CodeGen/CGClass.cpp
@@ -2776,9 +2776,12 @@
   RValue RV = EmitCall(calleeFnInfo, callee, returnSlot, callArgs);
 
   // If necessary, copy the returned value into the slot.
-  if (!resultType->isVoidType() && returnSlot.isNull())
+  if (!resultType->isVoidType() && returnSlot.isNull()) {
+    if (getLangOpts().ObjCAutoRefCount && resultType->isObjCRetainableType()) {
+      RV = RValue::get(EmitARCRetainAutoreleasedReturnValue(RV.getScalarVal()));
+    }
     EmitReturnOfRValue(RV, resultType);
-  else
+  } else
     EmitBranchThroughCleanup(ReturnBlock);
 }
 
Index: lib/CodeGen/CGBlocks.cpp
===================================================================
--- lib/CodeGen/CGBlocks.cpp
+++ lib/CodeGen/CGBlocks.cpp
@@ -1450,9 +1450,9 @@
   llvm::BasicBlock::iterator entry_ptr = Builder.GetInsertPoint();
   --entry_ptr;
 
-  if (IsLambdaConversionToBlock)
+  if (IsLambdaConversionToBlock) {
     EmitLambdaBlockInvokeBody();
-  else {
+  } else {
     PGO.assignRegionCounters(GlobalDecl(blockDecl), fn);
     incrementProfileCounter(blockDecl->getBody());
     EmitStmt(blockDecl->getBody());


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