[PATCH] D27358: [MS-ABI]V-base dtor called more than needed when throw happens in v-base ctor in window. Need add "complete object flag" check in eh cleanup code.

[Jennifer Yu via Phabricator via cfe-commits]

jyu2 set the repository for this revision to rL LLVM.
jyu2 updated this revision to Diff 80462.
jyu2 added a comment.

A typo.


Repository:
  rL LLVM

https://reviews.llvm.org/D27358

Files:
  lib/CodeGen/MicrosoftCXXABI.cpp
  test/CodeGenCXX/microsoft-abi-eh-cleanups.cpp


Index: lib/CodeGen/MicrosoftCXXABI.cpp
===================================================================
--- lib/CodeGen/MicrosoftCXXABI.cpp
+++ lib/CodeGen/MicrosoftCXXABI.cpp
@@ -164,6 +164,9 @@
   llvm::BasicBlock *
   EmitCtorCompleteObjectHandler(CodeGenFunction &CGF,
                                 const CXXRecordDecl *RD) override;
+  
+  llvm::BasicBlock *
+  EmitDtorCompleteObjectHandler(CodeGenFunction &CGF);
 
   void initializeHiddenVirtualInheritanceMembers(CodeGenFunction &CGF,
                                               const CXXRecordDecl *RD) override;
@@ -1127,6 +1130,25 @@
   return SkipVbaseCtorsBB;
 }
 
+llvm::BasicBlock *
+MicrosoftCXXABI::EmitDtorCompleteObjectHandler(CodeGenFunction &CGF) {
+  llvm::Value *IsMostDerivedClass = getStructorImplicitParamValue(CGF);
+  assert(IsMostDerivedClass &&
+         "ctor for a class with virtual bases must have an implicit parameter");
+  llvm::Value *IsCompleteObject =
+      CGF.Builder.CreateIsNotNull(IsMostDerivedClass, "is_complete_object");
+
+  llvm::BasicBlock *CallVbaseDtorsBB = CGF.createBasicBlock("Dtor.dtor_vbases");
+  llvm::BasicBlock *SkipVbaseDtorsBB = CGF.createBasicBlock("Dtor.skip_vbases");
+  CGF.Builder.CreateCondBr(IsCompleteObject,
+                           CallVbaseDtorsBB, SkipVbaseDtorsBB);
+
+  CGF.EmitBlock(CallVbaseDtorsBB);
+  // CGF will put the base dtor calls in this basic block for us later.
+    
+  return SkipVbaseDtorsBB;
+}
+
 void MicrosoftCXXABI::initializeHiddenVirtualInheritanceMembers(
     CodeGenFunction &CGF, const CXXRecordDecl *RD) {
   // In most cases, an override for a vbase virtual method can adjust
@@ -1502,11 +1524,24 @@
     This = adjustThisArgumentForVirtualFunctionCall(CGF, GlobalDecl(DD, Type),
                                                     This, false);
   }
+  
+  llvm::BasicBlock *BaseDtorEndBB = nullptr;
+  if (ForVirtualBase && isa<CXXConstructorDecl>(CGF.CurCodeDecl)) {
+    const CXXRecordDecl *ClassDecl =
+             cast<CXXConstructorDecl>(CGF.CurCodeDecl)->getParent();
+    if (ClassDecl != nullptr && ClassDecl->getNumVBases())
+      BaseDtorEndBB = EmitDtorCompleteObjectHandler(CGF);
+  }  
 
   CGF.EmitCXXDestructorCall(DD, Callee, This.getPointer(),
                             /*ImplicitParam=*/nullptr,
                             /*ImplicitParamTy=*/QualType(), nullptr,
                             getFromDtorType(Type));
+  if (BaseDtorEndBB) {
+    // Complete object handler should continue to be the remaining 
+    CGF.Builder.CreateBr(BaseDtorEndBB);
+    CGF.EmitBlock(BaseDtorEndBB);
+  } 
 }
 
 void MicrosoftCXXABI::emitVTableTypeMetadata(const VPtrInfo &Info,
Index: test/CodeGenCXX/microsoft-abi-eh-cleanups.cpp
===================================================================
--- test/CodeGenCXX/microsoft-abi-eh-cleanups.cpp
+++ test/CodeGenCXX/microsoft-abi-eh-cleanups.cpp
@@ -278,3 +278,38 @@
 // WIN32-LIFETIME: %[[bc2:.*]] = bitcast %"struct.lifetime_marker::C"* %[[c]] to i8*
 // WIN32-LIFETIME: call void @llvm.lifetime.end(i64 1, i8* %[[bc2]])
 }
+
+struct class_2 {
+  class_2();
+  virtual ~class_2();
+};
+struct class_1 : virtual class_2 {
+  class_1(){throw "Unhandled exception";}
+  virtual ~class_1() {}
+};
+struct class_0 : class_1 {
+  class_0() ;
+  virtual ~class_0() {}
+};
+
+class_0::class_0() {
+  // WIN32: define x86_thiscallcc %struct.class_0* @"\01??0class_0@@QAE@XZ"(%struct.class_0* returned %this, i32 %is_most_derived) 
+  // WIN32: store i32 %is_most_derived, i32* %[[IS_MOST_DERIVED_VAR:.*]], align 4
+  // WIN32: %[[IS_MOST_DERIVED_VAL:.*]] = load i32, i32* %[[IS_MOST_DERIVED_VAR]]
+  // WIN32: %[[SHOULD_CALL_VBASE_CTORS:.*]] = icmp ne i32 %[[IS_MOST_DERIVED_VAL]], 0
+  // WIN32: br i1 %[[SHOULD_CALL_VBASE_CTORS]], label %[[INIT_VBASES:.*]], label %[[SKIP_VBASES:.*]]
+  // WIN32: [[INIT_VBASES]]
+  // WIN32: br label %[[SKIP_VBASES]]
+  // WIN32: [[SKIP_VBASES]]
+// ehcleanup:
+  // WIN32: %[[CLEANUPPAD:.*]] = cleanuppad within none []
+  // WIN32-NEXT: bitcast %{{.*}}* %{{.*}} to i8*
+  // WIN32-NEXT: getelementptr inbounds i8, i8* %{{.*}}, i{{.*}} {{.}} 
+  // WIN32-NEXT: bitcast i8* %{{.*}} to %{{.*}}*
+  // WIN32-NEXT: %[[SHOULD_CALL_VBASE_DTOR:.*]] = icmp ne i32 %[[IS_MOST_DERIVED_VAL]], 0
+  // WIN32-NEXT: br i1 %[[SHOULD_CALL_VBASE_DTOR]], label %[[DTOR_VBASE:.*]], label %[[SKIP_VBASE:.*]]
+  // WIN32: [[DTOR_VBASE]]
+  // WIN32-NEXT: call x86_thiscallcc void @"\01??1class_2@@UAE@XZ"
+  // WIN32: br label %[[SKIP_VBASE]]
+  // WIN32: [[SKIP_VBASE]]
+}

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