Re-apply "Emit missing cleanups for stmt-expr" and other commits

clang/lib/CodeGen/CGCleanup.cpp

@@ -1169,25 +1169,6 @@ void CodeGenFunction::EmitBranchThroughCleanup(JumpDest Dest) {
   Builder.ClearInsertionPoint();
 }
 
-static bool IsUsedAsNormalCleanup(EHScopeStack &EHStack,
-                                  EHScopeStack::stable_iterator C) {
-  // If we needed a normal block for any reason, that counts.
-  if (cast<EHCleanupScope>(*EHStack.find(C)).getNormalBlock())
-    return true;
-
-  // Check whether any enclosed cleanups were needed.
-  for (EHScopeStack::stable_iterator
-         I = EHStack.getInnermostNormalCleanup();
-         I != C; ) {
-    assert(C.strictlyEncloses(I));
-    EHCleanupScope &S = cast<EHCleanupScope>(*EHStack.find(I));
-    if (S.getNormalBlock()) return true;
-    I = S.getEnclosingNormalCleanup();
-  }
-
-  return false;
-}
-
 static bool IsUsedAsEHCleanup(EHScopeStack &EHStack,
                               EHScopeStack::stable_iterator cleanup) {
   // If we needed an EH block for any reason, that counts.
@@ -1236,8 +1217,7 @@ static void SetupCleanupBlockActivation(CodeGenFunction &CGF,
   // Calculate whether the cleanup was used:
 
   //   - as a normal cleanup
-  if (Scope.isNormalCleanup() &&
-      (isActivatedInConditional || IsUsedAsNormalCleanup(CGF.EHStack, C))) {
+  if (Scope.isNormalCleanup()) {
     Scope.setTestFlagInNormalCleanup();
     needFlag = true;
   }
@@ -1250,13 +1230,16 @@ static void SetupCleanupBlockActivation(CodeGenFunction &CGF,
   }
 
   // If it hasn't yet been used as either, we're done.
-  if (!needFlag) return;
+  if (!needFlag)
+    return;
 
   Address var = Scope.getActiveFlag();
   if (!var.isValid()) {
+    CodeGenFunction::AllocaTrackerRAII AllocaTracker(CGF);
     var = CGF.CreateTempAlloca(CGF.Builder.getInt1Ty(), CharUnits::One(),
                                "cleanup.isactive");
     Scope.setActiveFlag(var);
+    Scope.AddAuxAllocas(AllocaTracker.Take());
 
     assert(dominatingIP && "no existing variable and no dominating IP!");
 

clang/test/CodeGenCXX/control-flow-in-stmt-expr.cpp

@@ -407,3 +407,72 @@ void TrivialABI() {
                      0;
                    }));
 }
+
+namespace CleanupFlag {
+struct A {
+  A() {}
+  ~A() {}
+};
+
+struct B {
+  B(const A&) {}
+  B() {}
+  ~B() {}
+};
+
+struct S {
+  A a;
+  B b;
+};
+
+int AcceptS(S s);
+
+void Accept2(int x, int y);
+
+void InactiveNormalCleanup() {
+  // CHECK-LABEL: define {{.*}}InactiveNormalCleanupEv()
+
+  // The first A{} below is an inactive normal cleanup which
+  // is not popped from EHStack on deactivation. This needs an
+  // "active" cleanup flag.
+
+  // CHECK: [[ACTIVE:%cleanup.isactive.*]] = alloca i1, align 1
+  // CHECK: call void [[A_CTOR:@.*AC1Ev]]
+  // CHECK: store i1 true, ptr [[ACTIVE]], align 1
+  // CHECK: call void [[A_CTOR]]
+  // CHECK: call void [[B_CTOR:@.*BC1ERKNS_1AE]]
+  // CHECK: store i1 false, ptr [[ACTIVE]], align 1
+  // CHECK: call noundef i32 [[ACCEPTS:@.*AcceptSENS_1SE]]
+  Accept2(AcceptS({.a = A{}, .b = A{}}), ({
+            if (foo()) return;
+            // CHECK: if.then:
+            // CHECK:   br label %cleanup
+            0;
+            // CHECK: if.end:
+            // CHECK:   call void [[ACCEPT2:@.*Accept2Eii]]
+            // CHECK:   br label %cleanup
+          }));
+  // CHECK: cleanup:
+  // CHECK:   call void [[S_DTOR:@.*SD1Ev]]
+  // CHECK:   call void [[A_DTOR:@.*AD1Ev]]
+  // CHECK:   %cleanup.is_active = load i1, ptr [[ACTIVE]]
+  // CHECK:   br i1 %cleanup.is_active, label %cleanup.action, label %cleanup.done
+
+  // CHECK: cleanup.action:
+  // CHECK:   call void [[A_DTOR]]
+
+  // The "active" cleanup flag is not required for unused cleanups.
+  Accept2(AcceptS({.a = A{}, .b = A{}}), 0);
+  // CHECK: cleanup.cont:
+  // CHECK:   call void [[A_CTOR]]
+  // CHECK-NOT: store i1 true
+  // CHECK:   call void [[A_CTOR]]
+  // CHECK:   call void [[B_CTOR]]
+  // CHECK-NOT: store i1 false
+  // CHECK:   call noundef i32 [[ACCEPTS]]
+  // CHECK:   call void [[ACCEPT2]]
+  // CHECK:   call void [[S_DTOR]]
+  // CHECK:   call void [[A_DTOR]]
+  // CHECK:   br label %return
+}
+}  // namespace CleanupFlag