[CIR] Add support for virtual destructor calls (#162725)

This adds support for calling virtual destructors.

Author: andykaylor

clang/lib/CIR/CodeGen/Address.h

@@ -17,6 +17,7 @@
 #include "mlir/IR/Value.h"
 #include "clang/AST/CharUnits.h"
 #include "clang/CIR/Dialect/IR/CIRTypes.h"
+#include "clang/CIR/MissingFeatures.h"
 #include "llvm/ADT/PointerIntPair.h"
 
 namespace clang::CIRGen {
@@ -90,6 +91,13 @@ class Address {
     return getPointer();
   }
 
+  /// Return the pointer contained in this class after authenticating it and
+  /// adding offset to it if necessary.
+  mlir::Value emitRawPointer() const {
+    assert(!cir::MissingFeatures::addressPointerAuthInfo());
+    return getBasePointer();
+  }
+
   mlir::Type getType() const {
     assert(mlir::cast<cir::PointerType>(
                pointerAndKnownNonNull.getPointer().getType())

clang/lib/CIR/CodeGen/CIRGenCXXABI.h

@@ -191,6 +191,15 @@ class CIRGenCXXABI {
   virtual void emitVTableDefinitions(CIRGenVTables &cgvt,
                                      const CXXRecordDecl *rd) = 0;
 
+  using DeleteOrMemberCallExpr =
+      llvm::PointerUnion<const CXXDeleteExpr *, const CXXMemberCallExpr *>;
+
+  virtual mlir::Value emitVirtualDestructorCall(CIRGenFunction &cgf,
+                                                const CXXDestructorDecl *dtor,
+                                                CXXDtorType dtorType,
+                                                Address thisAddr,
+                                                DeleteOrMemberCallExpr e) = 0;
+
   /// Emit any tables needed to implement virtual inheritance.  For Itanium,
   /// this emits virtual table tables.
   virtual void emitVirtualInheritanceTables(const CXXRecordDecl *rd) = 0;

clang/lib/CIR/CodeGen/CIRGenClass.cpp

@@ -895,6 +895,26 @@ void CIRGenFunction::destroyCXXObject(CIRGenFunction &cgf, Address addr,
 }
 
 namespace {
+mlir::Value loadThisForDtorDelete(CIRGenFunction &cgf,
+                                  const CXXDestructorDecl *dd) {
+  if (Expr *thisArg = dd->getOperatorDeleteThisArg())
+    return cgf.emitScalarExpr(thisArg);
+  return cgf.loadCXXThis();
+}
+
+/// Call the operator delete associated with the current destructor.
+struct CallDtorDelete final : EHScopeStack::Cleanup {
+  CallDtorDelete() {}
+
+  void emit(CIRGenFunction &cgf) override {
+    const CXXDestructorDecl *dtor = cast<CXXDestructorDecl>(cgf.curFuncDecl);
+    const CXXRecordDecl *classDecl = dtor->getParent();
+    cgf.emitDeleteCall(dtor->getOperatorDelete(),
+                       loadThisForDtorDelete(cgf, dtor),
+                       cgf.getContext().getCanonicalTagType(classDecl));
+  }
+};
+
 class DestroyField final : public EHScopeStack::Cleanup {
   const FieldDecl *field;
   CIRGenFunction::Destroyer *destroyer;
@@ -932,7 +952,18 @@ void CIRGenFunction::enterDtorCleanups(const CXXDestructorDecl *dd,
   // The deleting-destructor phase just needs to call the appropriate
   // operator delete that Sema picked up.
   if (dtorType == Dtor_Deleting) {
-    cgm.errorNYI(dd->getSourceRange(), "deleting destructor cleanups");
+    assert(dd->getOperatorDelete() &&
+           "operator delete missing - EnterDtorCleanups");
+    if (cxxStructorImplicitParamValue) {
+      cgm.errorNYI(dd->getSourceRange(), "deleting destructor with vtt");
+    } else {
+      if (dd->getOperatorDelete()->isDestroyingOperatorDelete()) {
+        cgm.errorNYI(dd->getSourceRange(),
+                     "deleting destructor with destroying operator delete");
+      } else {
+        ehStack.pushCleanup<CallDtorDelete>(NormalAndEHCleanup);
+      }
+    }
     return;
   }
 

clang/lib/CIR/CodeGen/CIRGenExprCXX.cpp

@@ -130,13 +130,11 @@ RValue CIRGenFunction::emitCXXMemberOrOperatorMemberCallExpr(
   const CXXMethodDecl *calleeDecl =
       devirtualizedMethod ? devirtualizedMethod : md;
   const CIRGenFunctionInfo *fInfo = nullptr;
-  if (isa<CXXDestructorDecl>(calleeDecl)) {
-    cgm.errorNYI(ce->getSourceRange(),
-                 "emitCXXMemberOrOperatorMemberCallExpr: destructor call");
-    return RValue::get(nullptr);
-  }
-
-  fInfo = &cgm.getTypes().arrangeCXXMethodDeclaration(calleeDecl);
+  if (const auto *dtor = dyn_cast<CXXDestructorDecl>(calleeDecl))
+    fInfo = &cgm.getTypes().arrangeCXXStructorDeclaration(
+        GlobalDecl(dtor, Dtor_Complete));
+  else
+    fInfo = &cgm.getTypes().arrangeCXXMethodDeclaration(calleeDecl);
 
   cir::FuncType ty = cgm.getTypes().getFunctionType(*fInfo);
 
@@ -151,9 +149,34 @@ RValue CIRGenFunction::emitCXXMemberOrOperatorMemberCallExpr(
   // because then we know what the type is.
   bool useVirtualCall = canUseVirtualCall && !devirtualizedMethod;
 
-  if (isa<CXXDestructorDecl>(calleeDecl)) {
-    cgm.errorNYI(ce->getSourceRange(),
-                 "emitCXXMemberOrOperatorMemberCallExpr: destructor call");
+  if (const auto *dtor = dyn_cast<CXXDestructorDecl>(calleeDecl)) {
+    assert(ce->arg_begin() == ce->arg_end() &&
+           "Destructor shouldn't have explicit parameters");
+    assert(returnValue.isNull() && "Destructor shouldn't have return value");
+    if (useVirtualCall) {
+      cgm.getCXXABI().emitVirtualDestructorCall(*this, dtor, Dtor_Complete,
+                                                thisPtr.getAddress(),
+                                                cast<CXXMemberCallExpr>(ce));
+    } else {
+      GlobalDecl globalDecl(dtor, Dtor_Complete);
+      CIRGenCallee callee;
+      assert(!cir::MissingFeatures::appleKext());
+      if (!devirtualizedMethod) {
+        callee = CIRGenCallee::forDirect(
+            cgm.getAddrOfCXXStructor(globalDecl, fInfo, ty), globalDecl);
+      } else {
+        cgm.errorNYI(ce->getSourceRange(), "devirtualized destructor call");
+        return RValue::get(nullptr);
+      }
+
+      QualType thisTy =
+          isArrow ? base->getType()->getPointeeType() : base->getType();
+      // CIRGen does not pass CallOrInvoke here (different from OG LLVM codegen)
+      // because in practice it always null even in OG.
+      emitCXXDestructorCall(globalDecl, callee, thisPtr.getPointer(), thisTy,
+                            /*implicitParam=*/nullptr,
+                            /*implicitParamTy=*/QualType(), ce);
+    }
     return RValue::get(nullptr);
   }
 

clang/lib/CIR/CodeGen/CIRGenFunction.cpp

@@ -678,7 +678,13 @@ void CIRGenFunction::emitDestructorBody(FunctionArgList &args) {
   // possible to delegate the destructor body to the complete
   // destructor.  Do so.
   if (dtorType == Dtor_Deleting) {
-    cgm.errorNYI(dtor->getSourceRange(), "deleting destructor");
+    RunCleanupsScope dtorEpilogue(*this);
+    enterDtorCleanups(dtor, Dtor_Deleting);
+    if (haveInsertPoint()) {
+      QualType thisTy = dtor->getFunctionObjectParameterType();
+      emitCXXDestructorCall(dtor, Dtor_Complete, /*forVirtualBase=*/false,
+                            /*delegating=*/false, loadCXXThisAddress(), thisTy);
+    }
     return;
   }
 

clang/lib/CIR/CodeGen/CIRGenItaniumCXXABI.cpp

@@ -95,7 +95,10 @@ class CIRGenItaniumCXXABI : public CIRGenCXXABI {
                                          clang::GlobalDecl gd, Address thisAddr,
                                          mlir::Type ty,
                                          SourceLocation loc) override;
-
+  mlir::Value emitVirtualDestructorCall(CIRGenFunction &cgf,
+                                        const CXXDestructorDecl *dtor,
+                                        CXXDtorType dtorType, Address thisAddr,
+                                        DeleteOrMemberCallExpr e) override;
   mlir::Value getVTableAddressPoint(BaseSubobject base,
                                     const CXXRecordDecl *vtableClass) override;
   mlir::Value getVTableAddressPointInStructorWithVTT(
@@ -465,6 +468,29 @@ void CIRGenItaniumCXXABI::emitVTableDefinitions(CIRGenVTables &cgvt,
   }
 }
 
+mlir::Value CIRGenItaniumCXXABI::emitVirtualDestructorCall(
+    CIRGenFunction &cgf, const CXXDestructorDecl *dtor, CXXDtorType dtorType,
+    Address thisAddr, DeleteOrMemberCallExpr expr) {
+  auto *callExpr = dyn_cast<const CXXMemberCallExpr *>(expr);
+  auto *delExpr = dyn_cast<const CXXDeleteExpr *>(expr);
+  assert((callExpr != nullptr) ^ (delExpr != nullptr));
+  assert(callExpr == nullptr || callExpr->arg_begin() == callExpr->arg_end());
+  assert(dtorType == Dtor_Deleting || dtorType == Dtor_Complete);
+
+  GlobalDecl globalDecl(dtor, dtorType);
+  const CIRGenFunctionInfo *fnInfo =
+      &cgm.getTypes().arrangeCXXStructorDeclaration(globalDecl);
+  const cir::FuncType &fnTy = cgm.getTypes().getFunctionType(*fnInfo);
+  auto callee = CIRGenCallee::forVirtual(callExpr, globalDecl, thisAddr, fnTy);
+
+  QualType thisTy =
+      callExpr ? callExpr->getObjectType() : delExpr->getDestroyedType();
+
+  cgf.emitCXXDestructorCall(globalDecl, callee, thisAddr.emitRawPointer(),
+                            thisTy, nullptr, QualType(), nullptr);
+  return nullptr;
+}
+
 void CIRGenItaniumCXXABI::emitVirtualInheritanceTables(
     const CXXRecordDecl *rd) {
   CIRGenVTables &vtables = cgm.getVTables();

clang/lib/CIR/CodeGen/CIRGenTypes.cpp

@@ -619,10 +619,8 @@ const CIRGenFunctionInfo &CIRGenTypes::arrangeGlobalDeclaration(GlobalDecl gd) {
   const auto *fd = cast<FunctionDecl>(gd.getDecl());
 
   if (isa<CXXConstructorDecl>(gd.getDecl()) ||
-      isa<CXXDestructorDecl>(gd.getDecl())) {
-    cgm.errorNYI(SourceLocation(),
-                 "arrangeGlobalDeclaration for C++ constructor or destructor");
-  }
+      isa<CXXDestructorDecl>(gd.getDecl()))
+    return arrangeCXXStructorDeclaration(gd);
 
   return arrangeFunctionDeclaration(fd);
 }

clang/lib/CIR/CodeGen/CIRGenVTables.cpp

@@ -120,12 +120,6 @@ mlir::Attribute CIRGenVTables::getVTableComponent(
   assert(!cir::MissingFeatures::vtableRelativeLayout());
 
   switch (component.getKind()) {
-  case VTableComponent::CK_CompleteDtorPointer:
-    cgm.errorNYI("getVTableComponent: CompleteDtorPointer");
-    return mlir::Attribute();
-  case VTableComponent::CK_DeletingDtorPointer:
-    cgm.errorNYI("getVTableComponent: DeletingDtorPointer");
-    return mlir::Attribute();
   case VTableComponent::CK_UnusedFunctionPointer:
     cgm.errorNYI("getVTableComponent: UnusedFunctionPointer");
     return mlir::Attribute();
@@ -148,7 +142,9 @@ mlir::Attribute CIRGenVTables::getVTableComponent(
            "expected GlobalViewAttr or ConstPtrAttr");
     return rtti;
 
-  case VTableComponent::CK_FunctionPointer: {
+  case VTableComponent::CK_FunctionPointer:
+  case VTableComponent::CK_CompleteDtorPointer:
+  case VTableComponent::CK_DeletingDtorPointer: {
     GlobalDecl gd = component.getGlobalDecl();
 
     assert(!cir::MissingFeatures::cudaSupport());

clang/test/CIR/CodeGen/virtual-destructor-calls.cpp

@@ -0,0 +1,129 @@
+// RUN: %clang_cc1 -triple aarch64-none-linux-android21 -std=c++20 -mconstructor-aliases -O0 -fclangir -emit-cir %s -o %t.cir
+// RUN: FileCheck --check-prefix=CIR --input-file=%t.cir %s
+// RUN: %clang_cc1 -triple aarch64-none-linux-android21 -std=c++20 -mconstructor-aliases -O0 -fclangir -emit-llvm %s -o %t-cir.ll
+// RUN: FileCheck --check-prefix=LLVM --input-file=%t-cir.ll %s
+// RUN: %clang_cc1 -triple aarch64-none-linux-android21 -std=c++20 -mconstructor-aliases -O0 -emit-llvm %s -o %t.ll
+// RUN: FileCheck --check-prefix=OGCG --input-file=%t.ll %s
+
+// TODO(cir): Try to emit base destructor as an alias at O1 or higher.
+
+// FIXME: LLVM IR dialect does not yet support function ptr globals, which precludes
+// a lot of the proper semantics for properly representing alias functions in LLVM
+// (see the note on LLVM_O1 below).
+
+struct Member {
+  ~Member();
+};
+
+struct A {
+  virtual ~A();
+};
+
+struct B : A {
+  Member m;
+  virtual ~B();
+};
+
+B::~B() { }
+
+// Aliases are inserted before the function definitions in LLVM IR
+// FIXME: These should have unnamed_addr set.
+// LLVM: @_ZN1BD1Ev = alias void (ptr), ptr @_ZN1BD2Ev
+// LLVM: @_ZN1CD1Ev = alias void (ptr), ptr @_ZN1CD2Ev
+
+// OGCG: @_ZN1BD1Ev = unnamed_addr alias void (ptr), ptr @_ZN1BD2Ev
+// OGCG: @_ZN1CD1Ev = unnamed_addr alias void (ptr), ptr @_ZN1CD2Ev
+
+
+// Base (D2) dtor for B: calls A's base dtor.
+
+// CIR: cir.func{{.*}} @_ZN1BD2Ev
+// CIR:   cir.call @_ZN6MemberD1Ev
+// CIR:   cir.call @_ZN1AD2Ev
+
+// LLVM: define{{.*}} void @_ZN1BD2Ev
+// LLVM:   call void @_ZN6MemberD1Ev
+// LLVM:   call void @_ZN1AD2Ev
+
+// OGCG: define{{.*}} @_ZN1BD2Ev
+// OGCG:   call void @_ZN6MemberD1Ev
+// OGCG:   call void @_ZN1AD2Ev
+
+// Complete (D1) dtor for B: just an alias because there are no virtual bases.
+
+// CIR: cir.func{{.*}} @_ZN1BD1Ev(!cir.ptr<!rec_B>) alias(@_ZN1BD2Ev)
+// This is defined above for LLVM and OGCG.
+
+// Deleting (D0) dtor for B: defers to the complete dtor but also calls operator delete.
+
+// CIR: cir.func{{.*}} @_ZN1BD0Ev
+// CIR:   cir.call @_ZN1BD1Ev(%[[THIS:.*]]) nothrow : (!cir.ptr<!rec_B>) -> ()
+// CIR:   %[[THIS_VOID:.*]] = cir.cast bitcast %[[THIS]] : !cir.ptr<!rec_B> -> !cir.ptr<!void>
+// CIR:   %[[SIZE:.*]] = cir.const #cir.int<16>
+// CIR:   cir.call @_ZdlPvm(%[[THIS_VOID]], %[[SIZE]])
+
+// LLVM: define{{.*}} void @_ZN1BD0Ev
+// LLVM:   call void @_ZN1BD1Ev(ptr %[[THIS:.*]])
+// LLVM:   call void @_ZdlPvm(ptr %[[THIS]], i64 16)
+
+// OGCG: define{{.*}} @_ZN1BD0Ev
+// OGCG:   call void @_ZN1BD1Ev(ptr{{.*}} %[[THIS:.*]])
+// OGCG:   call void @_ZdlPvm(ptr{{.*}} %[[THIS]], i64{{.*}} 16)
+
+struct C : B {
+  ~C();
+};
+
+C::~C() { }
+
+// Base (D2) dtor for C: calls B's base dtor.
+
+// CIR: cir.func{{.*}} @_ZN1CD2Ev
+// CIR:   %[[B:.*]] = cir.base_class_addr %[[THIS:.*]] : !cir.ptr<!rec_C> nonnull [0] -> !cir.ptr<!rec_B>
+// CIR:   cir.call @_ZN1BD2Ev(%[[B]])
+
+// LLVM: define{{.*}} void @_ZN1CD2Ev
+// LLVM:   call void @_ZN1BD2Ev
+
+// OGCG: define{{.*}} @_ZN1CD2Ev
+// OGCG:   call void @_ZN1BD2Ev
+
+// Complete (D1) dtor for C: just an alias because there are no virtual bases.
+
+// CIR: cir.func{{.*}} @_ZN1CD1Ev(!cir.ptr<!rec_C>) alias(@_ZN1CD2Ev)
+// This is defined above for LLVM and OGCG.
+
+
+// Deleting (D0) dtor for C: defers to the complete dtor but also calls operator delete.
+
+// CIR: cir.func{{.*}} @_ZN1CD0Ev
+// CIR:   cir.call @_ZN1CD1Ev(%[[THIS:.*]]) nothrow : (!cir.ptr<!rec_C>) -> ()
+// CIR:   %[[THIS_VOID:.*]] = cir.cast bitcast %[[THIS]] : !cir.ptr<!rec_C> -> !cir.ptr<!void>
+// CIR:   %[[SIZE:.*]] = cir.const #cir.int<16>
+// CIR:   cir.call @_ZdlPvm(%[[THIS_VOID]], %[[SIZE]])
+
+// LLVM: define{{.*}} void @_ZN1CD0Ev
+// LLVM:   call void @_ZN1CD1Ev(ptr %[[THIS:.*]])
+// LLVM:   call void @_ZdlPvm(ptr %[[THIS]], i64 16)
+
+// OGCG: define{{.*}} @_ZN1CD0Ev
+// OGCG:   call void @_ZN1CD1Ev(ptr{{.*}} %[[THIS:.*]])
+// OGCG:   call void @_ZdlPvm(ptr{{.*}} %[[THIS]], i64{{.*}} 16)
+
+namespace PR12798 {
+  // A qualified call to a base class destructor should not undergo virtual
+  // dispatch. Template instantiation used to lose the qualifier.
+  struct A { virtual ~A(); };
+  template<typename T> void f(T *p) { p->A::~A(); }
+
+  // CIR: cir.func{{.*}} @_ZN7PR127981fINS_1AEEEvPT_
+  // CIR:   cir.call @_ZN7PR127981AD1Ev
+
+  // LLVM: define{{.*}} @_ZN7PR127981fINS_1AEEEvPT_
+  // LLVM:   call void @_ZN7PR127981AD1Ev
+
+  // OGCG: define{{.*}} @_ZN7PR127981fINS_1AEEEvPT_
+  // OGCG:   call void @_ZN7PR127981AD1Ev
+
+  template void f(A*);
+}