diff --git a/clang/include/clang/CIR/MissingFeatures.h b/clang/include/clang/CIR/MissingFeatures.h index 0fac1b211239a..7e59989dc09f1 100644 --- a/clang/include/clang/CIR/MissingFeatures.h +++ b/clang/include/clang/CIR/MissingFeatures.h @@ -208,6 +208,7 @@ struct MissingFeatures { static bool dataLayoutTypeAllocSize() { return false; } static bool dataLayoutTypeStoreSize() { return false; } static bool deferredCXXGlobalInit() { return false; } + static bool deleteArray() { return false; } static bool devirtualizeMemberFunction() { return false; } static bool ehCleanupFlags() { return false; } static bool ehCleanupScope() { return false; } @@ -219,6 +220,7 @@ struct MissingFeatures { static bool emitCondLikelihoodViaExpectIntrinsic() { return false; } static bool emitLifetimeMarkers() { return false; } static bool emitLValueAlignmentAssumption() { return false; } + static bool emitNullCheckForDeleteCalls() { return false; } static bool emitNullabilityCheck() { return false; } static bool emitTypeCheck() { return false; } static bool emitTypeMetadataCodeForVCall() { return false; } diff --git a/clang/lib/CIR/CodeGen/CIRGenExprCXX.cpp b/clang/lib/CIR/CodeGen/CIRGenExprCXX.cpp index 1f7e3dd1fa7d2..83208bf226882 100644 --- a/clang/lib/CIR/CodeGen/CIRGenExprCXX.cpp +++ b/clang/lib/CIR/CodeGen/CIRGenExprCXX.cpp @@ -210,6 +210,60 @@ RValue CIRGenFunction::emitCXXMemberOrOperatorCall( return emitCall(fnInfo, callee, returnValue, args, nullptr, loc); } +namespace { +/// The parameters to pass to a usual operator delete. +struct UsualDeleteParams { + TypeAwareAllocationMode typeAwareDelete = TypeAwareAllocationMode::No; + bool destroyingDelete = false; + bool size = false; + AlignedAllocationMode alignment = AlignedAllocationMode::No; +}; +} // namespace + +// FIXME(cir): this should be shared with LLVM codegen +static UsualDeleteParams getUsualDeleteParams(const FunctionDecl *fd) { + UsualDeleteParams params; + + const FunctionProtoType *fpt = fd->getType()->castAs(); + auto ai = fpt->param_type_begin(), ae = fpt->param_type_end(); + + if (fd->isTypeAwareOperatorNewOrDelete()) { + params.typeAwareDelete = TypeAwareAllocationMode::Yes; + assert(ai != ae); + ++ai; + } + + // The first argument after the type-identity parameter (if any) is + // always a void* (or C* for a destroying operator delete for class + // type C). + ++ai; + + // The next parameter may be a std::destroying_delete_t. + if (fd->isDestroyingOperatorDelete()) { + params.destroyingDelete = true; + assert(ai != ae); + ++ai; + } + + // Figure out what other parameters we should be implicitly passing. + if (ai != ae && (*ai)->isIntegerType()) { + params.size = true; + ++ai; + } else { + assert(!isTypeAwareAllocation(params.typeAwareDelete)); + } + + if (ai != ae && (*ai)->isAlignValT()) { + params.alignment = AlignedAllocationMode::Yes; + ++ai; + } else { + assert(!isTypeAwareAllocation(params.typeAwareDelete)); + } + + assert(ai == ae && "unexpected usual deallocation function parameter"); + return params; +} + static mlir::Value emitCXXNewAllocSize(CIRGenFunction &cgf, const CXXNewExpr *e, unsigned minElements, mlir::Value &numElements, @@ -332,6 +386,117 @@ static RValue emitNewDeleteCall(CIRGenFunction &cgf, return rv; } +namespace { +/// Calls the given 'operator delete' on a single object. +struct CallObjectDelete final : EHScopeStack::Cleanup { + mlir::Value ptr; + const FunctionDecl *operatorDelete; + QualType elementType; + + CallObjectDelete(mlir::Value ptr, const FunctionDecl *operatorDelete, + QualType elementType) + : ptr(ptr), operatorDelete(operatorDelete), elementType(elementType) {} + + void emit(CIRGenFunction &cgf) override { + cgf.emitDeleteCall(operatorDelete, ptr, elementType); + } + + // This is a placeholder until EHCleanupScope is implemented. + size_t getSize() const override { + assert(!cir::MissingFeatures::ehCleanupScope()); + return sizeof(CallObjectDelete); + } +}; +} // namespace + +/// Emit the code for deleting a single object. +static void emitObjectDelete(CIRGenFunction &cgf, const CXXDeleteExpr *de, + Address ptr, QualType elementType) { + // C++11 [expr.delete]p3: + // If the static type of the object to be deleted is different from its + // dynamic type, the static type shall be a base class of the dynamic type + // of the object to be deleted and the static type shall have a virtual + // destructor or the behavior is undefined. + assert(!cir::MissingFeatures::emitTypeCheck()); + + const FunctionDecl *operatorDelete = de->getOperatorDelete(); + assert(!operatorDelete->isDestroyingOperatorDelete()); + + // Find the destructor for the type, if applicable. If the + // destructor is virtual, we'll just emit the vcall and return. + const CXXDestructorDecl *dtor = nullptr; + if (const auto *rd = elementType->getAsCXXRecordDecl()) { + if (rd->hasDefinition() && !rd->hasTrivialDestructor()) { + dtor = rd->getDestructor(); + + if (dtor->isVirtual()) { + cgf.cgm.errorNYI(de->getSourceRange(), + "emitObjectDelete: virtual destructor"); + } + } + } + + // Make sure that we call delete even if the dtor throws. + // This doesn't have to a conditional cleanup because we're going + // to pop it off in a second. + cgf.ehStack.pushCleanup( + NormalAndEHCleanup, ptr.getPointer(), operatorDelete, elementType); + + if (dtor) { + cgf.emitCXXDestructorCall(dtor, Dtor_Complete, + /*ForVirtualBase=*/false, + /*Delegating=*/false, ptr, elementType); + } else if (elementType.getObjCLifetime()) { + assert(!cir::MissingFeatures::objCLifetime()); + cgf.cgm.errorNYI(de->getSourceRange(), "emitObjectDelete: ObjCLifetime"); + } + + // In traditional LLVM codegen null checks are emitted to save a delete call. + // In CIR we optimize for size by default, the null check should be added into + // this function callers. + assert(!cir::MissingFeatures::emitNullCheckForDeleteCalls()); + + cgf.popCleanupBlock(); +} + +void CIRGenFunction::emitCXXDeleteExpr(const CXXDeleteExpr *e) { + const Expr *arg = e->getArgument(); + Address ptr = emitPointerWithAlignment(arg); + + // Null check the pointer. + // + // We could avoid this null check if we can determine that the object + // destruction is trivial and doesn't require an array cookie; we can + // unconditionally perform the operator delete call in that case. For now, we + // assume that deleted pointers are null rarely enough that it's better to + // keep the branch. This might be worth revisiting for a -O0 code size win. + // + // CIR note: emit the code size friendly by default for now, such as mentioned + // in `emitObjectDelete`. + assert(!cir::MissingFeatures::emitNullCheckForDeleteCalls()); + QualType deleteTy = e->getDestroyedType(); + + // A destroying operator delete overrides the entire operation of the + // delete expression. + if (e->getOperatorDelete()->isDestroyingOperatorDelete()) { + cgm.errorNYI(e->getSourceRange(), + "emitCXXDeleteExpr: destroying operator delete"); + return; + } + + // We might be deleting a pointer to array. + deleteTy = getContext().getBaseElementType(deleteTy); + ptr = ptr.withElementType(builder, convertTypeForMem(deleteTy)); + + if (e->isArrayForm()) { + assert(!cir::MissingFeatures::deleteArray()); + cgm.errorNYI(e->getSourceRange(), "emitCXXDeleteExpr: array delete"); + return; + } else { + emitObjectDelete(*this, e, ptr, deleteTy); + } +} + mlir::Value CIRGenFunction::emitCXXNewExpr(const CXXNewExpr *e) { // The element type being allocated. QualType allocType = getContext().getBaseElementType(e->getAllocatedType()); @@ -443,3 +608,53 @@ mlir::Value CIRGenFunction::emitCXXNewExpr(const CXXNewExpr *e) { allocSizeWithoutCookie); return result.getPointer(); } + +void CIRGenFunction::emitDeleteCall(const FunctionDecl *deleteFD, + mlir::Value ptr, QualType deleteTy) { + assert(!cir::MissingFeatures::deleteArray()); + + const auto *deleteFTy = deleteFD->getType()->castAs(); + CallArgList deleteArgs; + + UsualDeleteParams params = getUsualDeleteParams(deleteFD); + auto paramTypeIt = deleteFTy->param_type_begin(); + + // Pass std::type_identity tag if present + if (isTypeAwareAllocation(params.typeAwareDelete)) + cgm.errorNYI(deleteFD->getSourceRange(), + "emitDeleteCall: type aware delete"); + + // Pass the pointer itself. + QualType argTy = *paramTypeIt++; + mlir::Value deletePtr = + builder.createBitcast(ptr.getLoc(), ptr, convertType(argTy)); + deleteArgs.add(RValue::get(deletePtr), argTy); + + // Pass the std::destroying_delete tag if present. + if (params.destroyingDelete) + cgm.errorNYI(deleteFD->getSourceRange(), + "emitDeleteCall: destroying delete"); + + // Pass the size if the delete function has a size_t parameter. + if (params.size) { + QualType sizeType = *paramTypeIt++; + CharUnits deleteTypeSize = getContext().getTypeSizeInChars(deleteTy); + assert(mlir::isa(convertType(sizeType)) && + "expected cir::IntType"); + cir::ConstantOp size = builder.getConstInt( + *currSrcLoc, convertType(sizeType), deleteTypeSize.getQuantity()); + + deleteArgs.add(RValue::get(size), sizeType); + } + + // Pass the alignment if the delete function has an align_val_t parameter. + if (isAlignedAllocation(params.alignment)) + cgm.errorNYI(deleteFD->getSourceRange(), + "emitDeleteCall: aligned allocation"); + + assert(paramTypeIt == deleteFTy->param_type_end() && + "unknown parameter to usual delete function"); + + // Emit the call to delete. + emitNewDeleteCall(*this, deleteFD, deleteFTy, deleteArgs); +} diff --git a/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp b/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp index 276adcfc5c6be..dc340660336d9 100644 --- a/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp +++ b/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp @@ -687,6 +687,10 @@ class ScalarExprEmitter : public StmtVisitor { mlir::Value VisitCXXNewExpr(const CXXNewExpr *e) { return cgf.emitCXXNewExpr(e); } + mlir::Value VisitCXXDeleteExpr(const CXXDeleteExpr *e) { + cgf.emitCXXDeleteExpr(e); + return {}; + } mlir::Value VisitCXXThrowExpr(const CXXThrowExpr *e) { cgf.emitCXXThrowExpr(e); @@ -2355,4 +2359,4 @@ mlir::Value CIRGenFunction::emitScalarPrePostIncDec(const UnaryOperator *e, bool isPre) { return ScalarExprEmitter(*this, builder) .emitScalarPrePostIncDec(e, lv, kind, isPre); -} \ No newline at end of file +} diff --git a/clang/lib/CIR/CodeGen/CIRGenFunction.h b/clang/lib/CIR/CodeGen/CIRGenFunction.h index b91bb1567f257..8429d414d944f 100644 --- a/clang/lib/CIR/CodeGen/CIRGenFunction.h +++ b/clang/lib/CIR/CodeGen/CIRGenFunction.h @@ -1197,6 +1197,8 @@ class CIRGenFunction : public CIRGenTypeCache { bool delegating, Address thisAddr, CallArgList &args, clang::SourceLocation loc); + void emitCXXDeleteExpr(const CXXDeleteExpr *e); + void emitCXXDestructorCall(const CXXDestructorDecl *dd, CXXDtorType type, bool forVirtualBase, bool delegating, Address thisAddr, QualType thisTy); @@ -1244,6 +1246,9 @@ class CIRGenFunction : public CIRGenTypeCache { void emitDelegatingCXXConstructorCall(const CXXConstructorDecl *ctor, const FunctionArgList &args); + void emitDeleteCall(const FunctionDecl *deleteFD, mlir::Value ptr, + QualType deleteTy); + mlir::LogicalResult emitDoStmt(const clang::DoStmt &s); /// Emit an expression as an initializer for an object (variable, field, etc.) diff --git a/clang/test/CIR/CodeGen/delete.cpp b/clang/test/CIR/CodeGen/delete.cpp new file mode 100644 index 0000000000000..f21d203f266e5 --- /dev/null +++ b/clang/test/CIR/CodeGen/delete.cpp @@ -0,0 +1,88 @@ +// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -std=c++20 -fclangir -mconstructor-aliases -emit-cir %s -o %t.cir +// RUN: FileCheck --check-prefix=CIR --input-file=%t.cir %s +// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -std=c++20 -fclangir -mconstructor-aliases -emit-llvm %s -o %t-cir.ll +// RUN: FileCheck --check-prefix=LLVM --input-file=%t-cir.ll %s +// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -std=c++20 -mconstructor-aliases -emit-llvm %s -o %t.ll +// RUN: FileCheck --check-prefix=OGCG --input-file=%t.ll %s + +typedef __typeof(sizeof(int)) size_t; + +struct SizedDelete { + void operator delete(void*, size_t); + int member; +}; +void test_sized_delete(SizedDelete *x) { + delete x; +} + +// SizedDelete::operator delete(void*, unsigned long) +// CIR: cir.func private @_ZN11SizedDeletedlEPvm(!cir.ptr, !u64i) +// LLVM: declare void @_ZN11SizedDeletedlEPvm(ptr, i64) + +// CIR: cir.func dso_local @_Z17test_sized_deleteP11SizedDelete +// CIR: %[[X:.*]] = cir.load{{.*}} %{{.*}} +// CIR: %[[X_CAST:.*]] = cir.cast(bitcast, %[[X]] : !cir.ptr), !cir.ptr +// CIR: %[[OBJ_SIZE:.*]] = cir.const #cir.int<4> : !u64i +// CIR: cir.call @_ZN11SizedDeletedlEPvm(%[[X_CAST]], %[[OBJ_SIZE]]) nothrow : (!cir.ptr, !u64i) -> () + +// LLVM: define dso_local void @_Z17test_sized_deleteP11SizedDelete +// LLVM: %[[X:.*]] = load ptr, ptr %{{.*}} +// LLVM: call void @_ZN11SizedDeletedlEPvm(ptr %[[X]], i64 4) + +// OGCG: define dso_local void @_Z17test_sized_deleteP11SizedDelete +// OGCG: %[[X:.*]] = load ptr, ptr %{{.*}} +// OGCG: %[[ISNULL:.*]] = icmp eq ptr %[[X]], null +// OGCG: br i1 %[[ISNULL]], label %{{.*}}, label %[[DELETE_NOTNULL:.*]] +// OGCG: [[DELETE_NOTNULL]]: +// OGCG: call void @_ZN11SizedDeletedlEPvm(ptr noundef %[[X]], i64 noundef 4) + +// This function is declared below the call in OGCG. +// OGCG: declare void @_ZN11SizedDeletedlEPvm(ptr noundef, i64 noundef) + +struct Contents { + ~Contents() {} +}; +struct Container { + Contents *contents; + ~Container(); +}; +Container::~Container() { delete contents; } + +// Contents::~Contents() +// CIR: cir.func comdat linkonce_odr @_ZN8ContentsD2Ev +// LLVM: define linkonce_odr void @_ZN8ContentsD2Ev + +// operator delete(void*, unsigned long) +// CIR: cir.func private @_ZdlPvm(!cir.ptr, !u64i) +// LLVM: declare void @_ZdlPvm(ptr, i64) + +// Container::~Container() +// CIR: cir.func dso_local @_ZN9ContainerD2Ev +// CIR: %[[THIS:.*]] = cir.load %{{.*}} +// CIR: %[[CONTENTS_PTR_ADDR:.*]] = cir.get_member %[[THIS]][0] {name = "contents"} : !cir.ptr -> !cir.ptr> +// CIR: %[[CONTENTS_PTR:.*]] = cir.load{{.*}} %[[CONTENTS_PTR_ADDR]] +// CIR: cir.call @_ZN8ContentsD2Ev(%[[CONTENTS_PTR]]) nothrow : (!cir.ptr) -> () +// CIR: %[[CONTENTS_CAST:.*]] = cir.cast(bitcast, %[[CONTENTS_PTR]] : !cir.ptr), !cir.ptr +// CIR: %[[OBJ_SIZE:.*]] = cir.const #cir.int<1> : !u64i +// CIR: cir.call @_ZdlPvm(%[[CONTENTS_CAST]], %[[OBJ_SIZE]]) nothrow : (!cir.ptr, !u64i) -> () + +// LLVM: define dso_local void @_ZN9ContainerD2Ev +// LLVM: %[[THIS:.*]] = load ptr, ptr %{{.*}} +// LLVM: %[[CONTENTS_PTR_ADDR:.*]] = getelementptr %struct.Container, ptr %[[THIS]], i32 0, i32 0 +// LLVM: %[[CONTENTS_PTR:.*]] = load ptr, ptr %[[CONTENTS_PTR_ADDR]] +// LLVM: call void @_ZN8ContentsD2Ev(ptr %[[CONTENTS_PTR]]) +// LLVM: call void @_ZdlPvm(ptr %[[CONTENTS_PTR]], i64 1) + +// OGCG: define dso_local void @_ZN9ContainerD2Ev +// OGCG: %[[THIS:.*]] = load ptr, ptr %{{.*}} +// OGCG: %[[CONTENTS:.*]] = getelementptr inbounds nuw %struct.Container, ptr %[[THIS]], i32 0, i32 0 +// OGCG: %[[CONTENTS_PTR:.*]] = load ptr, ptr %[[CONTENTS]] +// OGCG: %[[ISNULL:.*]] = icmp eq ptr %[[CONTENTS_PTR]], null +// OGCG: br i1 %[[ISNULL]], label %{{.*}}, label %[[DELETE_NOTNULL:.*]] +// OGCG: [[DELETE_NOTNULL]]: +// OGCG: call void @_ZN8ContentsD2Ev(ptr noundef nonnull align 1 dereferenceable(1) %[[CONTENTS_PTR]]) +// OGCG: call void @_ZdlPvm(ptr noundef %[[CONTENTS_PTR]], i64 noundef 1) + +// These functions are declared/defined below the calls in OGCG. +// OGCG: define linkonce_odr void @_ZN8ContentsD2Ev +// OGCG: declare void @_ZdlPvm(ptr noundef, i64 noundef)