Merge pull request #4211 from apple/ahmedbougacha/arccontract-twice-bundle

[ObjCARC] Tolerate missing attachedcall op by ignoring the bundle.

Author: ahmedbougacha

llvm/lib/Transforms/ObjCARC/ObjCARC.cpp

@@ -103,12 +103,16 @@ CallInst *BundledRetainClaimRVs::insertRVCallWithColors(
     Instruction *InsertPt, CallBase *AnnotatedCall,
     const DenseMap<BasicBlock *, ColorVector> &BlockColors) {
   IRBuilder<> Builder(InsertPt);
-  Function *Func = *objcarc::getAttachedARCFunction(AnnotatedCall);
-  assert(Func && "operand isn't a Function");
-  Type *ParamTy = Func->getArg(0)->getType();
+  Optional<Function *> Func = objcarc::getAttachedARCFunction(AnnotatedCall);
+  // This might be a call with an empty bundle, because contract already ran.
+  // In that case, we don't have to insert another call.
+  if (!Func)
+    return nullptr;
+
+  Type *ParamTy = (*Func)->getArg(0)->getType();
   Value *CallArg = Builder.CreateBitCast(AnnotatedCall, ParamTy);
   auto *Call =
-      createCallInstWithColors(Func, CallArg, "", InsertPt, BlockColors);
+      createCallInstWithColors(*Func, CallArg, "", InsertPt, BlockColors);
   RVCalls[Call] = AnnotatedCall;
   return Call;
 }

llvm/lib/Transforms/ObjCARC/ObjCARCContract.cpp

@@ -580,8 +580,8 @@ bool ObjCARCContract::run(Function &F, AAResults *A, DominatorTree *D) {
 
     if (auto *CI = dyn_cast<CallInst>(Inst))
       if (objcarc::hasAttachedCallOpBundle(CI)) {
-        BundledInsts->insertRVCallWithColors(&*I, CI, BlockColors);
-        --I;
+        if (BundledInsts->insertRVCallWithColors(&*I, CI, BlockColors))
+          --I;
         Changed = true;
       }
 

llvm/test/Transforms/ObjCARC/contract-rv-attr-empty-bundle.ll

@@ -0,0 +1,32 @@
+; RUN: opt -objc-arc-contract -S < %s | FileCheck %s
+; RUN: opt -passes=objc-arc-contract -S < %s | FileCheck %s
+
+; CHECK-LABEL: define void @test0() {
+; CHECK: %[[CALL:.*]] = notail call i8* @foo() [ "clang.arc.attachedcall"() ]
+; CHECK-NEXT: call void asm sideeffect "mov\09fp, fp\09\09// marker for objc_retainAutoreleaseReturnValue", ""()
+; CHECK-NEXT: call i8* @llvm.objc.retainAutoreleasedReturnValue(i8* %[[CALL]])
+
+define void @test0() {
+  %call1 = notail call i8* @foo() [ "clang.arc.attachedcall"() ]
+  call i8* @llvm.objc.retainAutoreleasedReturnValue(i8* %call1)
+  ret void
+}
+
+; CHECK-LABEL: define void @test1() {
+; CHECK: %[[CALL:.*]] = notail call i8* @foo() [ "clang.arc.attachedcall"() ]
+; CHECK-NEXT: call void asm sideeffect "mov\09fp, fp\09\09// marker for objc_retainAutoreleaseReturnValue", ""()
+; CHECK-NEXT: call i8* @llvm.objc.unsafeClaimAutoreleasedReturnValue(i8* %[[CALL]])
+
+define void @test1() {
+  %call1 = notail call i8* @foo() [ "clang.arc.attachedcall"() ]
+  call i8* @llvm.objc.unsafeClaimAutoreleasedReturnValue(i8* %call1)
+  ret void
+}
+
+declare i8* @foo()
+declare i8* @llvm.objc.retainAutoreleasedReturnValue(i8*)
+declare i8* @llvm.objc.unsafeClaimAutoreleasedReturnValue(i8*)
+
+!llvm.module.flags = !{!0}
+
+!0 = !{i32 1, !"clang.arc.retainAutoreleasedReturnValueMarker", !"mov\09fp, fp\09\09// marker for objc_retainAutoreleaseReturnValue"}