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llvm / llvm-project / 5452f21b1ad46d1040ad2d313ed220bf3b59677e / . / clang / lib / CIR / CodeGen / CIRGenClass.cpp
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//===--- CIRGenClass.cpp - Emit CIR Code for C++ classes --------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This contains code dealing with C++ code generation of classes
//
//===----------------------------------------------------------------------===//
#include "CIRGenCXXABI.h"
#include "CIRGenFunction.h"
#include "clang/AST/EvaluatedExprVisitor.h"
#include "clang/AST/RecordLayout.h"
#include "clang/Basic/NoSanitizeList.h"
#include "clang/Basic/TargetBuiltins.h"
#include "clang/CIR/MissingFeatures.h"
using namespace clang;
using namespace cir;
/// Checks whether the given constructor is a valid subject for the
/// complete-to-base constructor delgation optimization, i.e. emitting the
/// complete constructor as a simple call to the base constructor.
bool CIRGenFunction::IsConstructorDelegationValid(
const CXXConstructorDecl *Ctor) {
// Currently we disable the optimization for classes with virtual bases
// because (1) the address of parameter variables need to be consistent across
// all initializers but (2) the delegate function call necessarily creates a
// second copy of the parameter variable.
//
// The limiting example (purely theoretical AFAIK):
// struct A { A(int &c) { c++; } };
// struct A : virtual A {
// B(int count) : A(count) { printf("%d\n", count); }
// };
// ...although even this example could in principle be emitted as a delegation
// since the address of the parameter doesn't escape.
if (Ctor->getParent()->getNumVBases())
return false;
// We also disable the optimization for variadic functions because it's
// impossible to "re-pass" varargs.
if (Ctor->getType()->castAs<FunctionProtoType>()->isVariadic())
return false;
// FIXME: Decide if we can do a delegation of a delegating constructor.
if (Ctor->isDelegatingConstructor())
return false;
return true;
}
/// TODO(cir): strong candidate for AST helper to be shared between LLVM and CIR
/// codegen.
static bool isMemcpyEquivalentSpecialMember(const CXXMethodDecl *D) {
auto *CD = dyn_cast<CXXConstructorDecl>(D);
if (!(CD && CD->isCopyOrMoveConstructor()) &&
!D->isCopyAssignmentOperator() && !D->isMoveAssignmentOperator())
return false;
// We can emit a memcpy for a trivial copy or move constructor/assignment.
if (D->isTrivial() && !D->getParent()->mayInsertExtraPadding())
return true;
// We *must* emit a memcpy for a defaulted union copy or move op.
if (D->getParent()->isUnion() && D->isDefaulted())
return true;
return false;
}
namespace {
/// TODO(cir): a lot of what we see under this namespace is a strong candidate
/// to be shared between LLVM and CIR codegen.
/// RAII object to indicate that codegen is copying the value representation
/// instead of the object representation. Useful when copying a struct or
/// class which has uninitialized members and we're only performing
/// lvalue-to-rvalue conversion on the object but not its members.
class CopyingValueRepresentation {
public:
explicit CopyingValueRepresentation(CIRGenFunction &CGF)
: CGF(CGF), OldSanOpts(CGF.SanOpts) {
CGF.SanOpts.set(SanitizerKind::Bool, false);
CGF.SanOpts.set(SanitizerKind::Enum, false);
}
~CopyingValueRepresentation() { CGF.SanOpts = OldSanOpts; }
private:
CIRGenFunction &CGF;
SanitizerSet OldSanOpts;
};
class FieldMemcpyizer {
public:
FieldMemcpyizer(CIRGenFunction &CGF, const CXXRecordDecl *ClassDecl,
const VarDecl *SrcRec)
: CGF(CGF), ClassDecl(ClassDecl),
// SrcRec(SrcRec),
RecLayout(CGF.getContext().getASTRecordLayout(ClassDecl)),
FirstField(nullptr), LastField(nullptr), FirstFieldOffset(0),
LastFieldOffset(0), LastAddedFieldIndex(0) {
(void)SrcRec;
}
bool isMemcpyableField(FieldDecl *F) const {
// Never memcpy fields when we are adding poised paddings.
if (CGF.getContext().getLangOpts().SanitizeAddressFieldPadding)
return false;
Qualifiers Qual = F->getType().getQualifiers();
if (Qual.hasVolatile() || Qual.hasObjCLifetime())
return false;
return true;
}
void addMemcpyableField(FieldDecl *F) {
if (F->isZeroSize(CGF.getContext()))
return;
if (!FirstField)
addInitialField(F);
else
addNextField(F);
}
CharUnits getMemcpySize(uint64_t FirstByteOffset) const {
ASTContext &Ctx = CGF.getContext();
unsigned LastFieldSize =
LastField->isBitField()
? LastField->getBitWidthValue(Ctx)
: Ctx.toBits(
Ctx.getTypeInfoDataSizeInChars(LastField->getType()).Width);
uint64_t MemcpySizeBits = LastFieldOffset + LastFieldSize -
FirstByteOffset + Ctx.getCharWidth() - 1;
CharUnits MemcpySize = Ctx.toCharUnitsFromBits(MemcpySizeBits);
return MemcpySize;
}
void buildMemcpy() {
// Give the subclass a chance to bail out if it feels the memcpy isn't worth
// it (e.g. Hasn't aggregated enough data).
if (!FirstField) {
return;
}
llvm_unreachable("NYI");
}
void reset() { FirstField = nullptr; }
protected:
CIRGenFunction &CGF;
const CXXRecordDecl *ClassDecl;
private:
void buildMemcpyIR(Address DestPtr, Address SrcPtr, CharUnits Size) {
llvm_unreachable("NYI");
}
void addInitialField(FieldDecl *F) {
FirstField = F;
LastField = F;
FirstFieldOffset = RecLayout.getFieldOffset(F->getFieldIndex());
LastFieldOffset = FirstFieldOffset;
LastAddedFieldIndex = F->getFieldIndex();
}
void addNextField(FieldDecl *F) {
// For the most part, the following invariant will hold:
// F->getFieldIndex() == LastAddedFieldIndex + 1
// The one exception is that Sema won't add a copy-initializer for an
// unnamed bitfield, which will show up here as a gap in the sequence.
assert(F->getFieldIndex() >= LastAddedFieldIndex + 1 &&
"Cannot aggregate fields out of order.");
LastAddedFieldIndex = F->getFieldIndex();
// The 'first' and 'last' fields are chosen by offset, rather than field
// index. This allows the code to support bitfields, as well as regular
// fields.
uint64_t FOffset = RecLayout.getFieldOffset(F->getFieldIndex());
if (FOffset < FirstFieldOffset) {
FirstField = F;
FirstFieldOffset = FOffset;
} else if (FOffset >= LastFieldOffset) {
LastField = F;
LastFieldOffset = FOffset;
}
}
// const VarDecl *SrcRec;
const ASTRecordLayout &RecLayout;
FieldDecl *FirstField;
FieldDecl *LastField;
uint64_t FirstFieldOffset, LastFieldOffset;
unsigned LastAddedFieldIndex;
};
static void buildLValueForAnyFieldInitialization(CIRGenFunction &CGF,
CXXCtorInitializer *MemberInit,
LValue &LHS) {
FieldDecl *Field = MemberInit->getAnyMember();
if (MemberInit->isIndirectMemberInitializer()) {
llvm_unreachable("NYI");
} else {
LHS = CGF.buildLValueForFieldInitialization(LHS, Field, Field->getName());
}
}
static void buildMemberInitializer(CIRGenFunction &CGF,
const CXXRecordDecl *ClassDecl,
CXXCtorInitializer *MemberInit,
const CXXConstructorDecl *Constructor,
FunctionArgList &Args) {
// TODO: ApplyDebugLocation
assert(MemberInit->isAnyMemberInitializer() &&
"Mush have member initializer!");
assert(MemberInit->getInit() && "Must have initializer!");
// non-static data member initializers
FieldDecl *Field = MemberInit->getAnyMember();
QualType FieldType = Field->getType();
auto ThisPtr = CGF.LoadCXXThis();
QualType RecordTy = CGF.getContext().getTypeDeclType(ClassDecl);
LValue LHS;
// If a base constructor is being emitted, create an LValue that has the
// non-virtual alignment.
if (CGF.CurGD.getCtorType() == Ctor_Base)
LHS = CGF.MakeNaturalAlignPointeeAddrLValue(ThisPtr, RecordTy);
else
LHS = CGF.MakeNaturalAlignAddrLValue(ThisPtr, RecordTy);
buildLValueForAnyFieldInitialization(CGF, MemberInit, LHS);
// Special case: If we are in a copy or move constructor, and we are copying
// an array off PODs or classes with tirival copy constructors, ignore the AST
// and perform the copy we know is equivalent.
// FIXME: This is hacky at best... if we had a bit more explicit information
// in the AST, we could generalize it more easily.
const ConstantArrayType *Array =
CGF.getContext().getAsConstantArrayType(FieldType);
if (Array && Constructor->isDefaulted() &&
Constructor->isCopyOrMoveConstructor()) {
llvm_unreachable("NYI");
}
CGF.buildInitializerForField(Field, LHS, MemberInit->getInit());
}
class ConstructorMemcpyizer : public FieldMemcpyizer {
private:
/// Get source argument for copy constructor. Returns null if not a copy
/// constructor.
static const VarDecl *getTrivialCopySource(CIRGenFunction &CGF,
const CXXConstructorDecl *CD,
FunctionArgList &Args) {
if (CD->isCopyOrMoveConstructor() && CD->isDefaulted())
return Args[CGF.CGM.getCXXABI().getSrcArgforCopyCtor(CD, Args)];
return nullptr;
}
// Returns true if a CXXCtorInitializer represents a member initialization
// that can be rolled into a memcpy.
bool isMemberInitMemcpyable(CXXCtorInitializer *MemberInit) const {
if (!MemcpyableCtor)
return false;
assert(!MissingFeatures::fieldMemcpyizerBuildMemcpy());
return false;
}
public:
ConstructorMemcpyizer(CIRGenFunction &CGF, const CXXConstructorDecl *CD,
FunctionArgList &Args)
: FieldMemcpyizer(CGF, CD->getParent(),
getTrivialCopySource(CGF, CD, Args)),
ConstructorDecl(CD),
MemcpyableCtor(CD->isDefaulted() && CD->isCopyOrMoveConstructor() &&
CGF.getLangOpts().getGC() == LangOptions::NonGC),
Args(Args) {}
void addMemberInitializer(CXXCtorInitializer *MemberInit) {
if (isMemberInitMemcpyable(MemberInit)) {
AggregatedInits.push_back(MemberInit);
addMemcpyableField(MemberInit->getMember());
} else {
buildAggregatedInits();
buildMemberInitializer(CGF, ConstructorDecl->getParent(), MemberInit,
ConstructorDecl, Args);
}
}
void buildAggregatedInits() {
if (AggregatedInits.size() <= 1) {
// This memcpy is too small to be worthwhile. Fall back on default
// codegen.
if (!AggregatedInits.empty()) {
llvm_unreachable("NYI");
}
reset();
return;
}
pushEHDestructors();
buildMemcpy();
AggregatedInits.clear();
}
void pushEHDestructors() {
Address ThisPtr = CGF.LoadCXXThisAddress();
QualType RecordTy = CGF.getContext().getTypeDeclType(ClassDecl);
LValue LHS = CGF.makeAddrLValue(ThisPtr, RecordTy);
(void)LHS;
for (unsigned i = 0; i < AggregatedInits.size(); ++i) {
CXXCtorInitializer *MemberInit = AggregatedInits[i];
QualType FieldType = MemberInit->getAnyMember()->getType();
QualType::DestructionKind dtorKind = FieldType.isDestructedType();
if (!CGF.needsEHCleanup(dtorKind))
continue;
LValue FieldLHS = LHS;
buildLValueForAnyFieldInitialization(CGF, MemberInit, FieldLHS);
CGF.pushEHDestroy(dtorKind, FieldLHS.getAddress(), FieldType);
}
}
void finish() { buildAggregatedInits(); }
private:
const CXXConstructorDecl *ConstructorDecl;
bool MemcpyableCtor;
FunctionArgList &Args;
SmallVector<CXXCtorInitializer *, 16> AggregatedInits;
};
class AssignmentMemcpyizer : public FieldMemcpyizer {
private:
// Returns the memcpyable field copied by the given statement, if one
// exists. Otherwise returns null.
FieldDecl *getMemcpyableField(Stmt *S) {
if (!AssignmentsMemcpyable)
return nullptr;
if (BinaryOperator *BO = dyn_cast<BinaryOperator>(S)) {
// Recognise trivial assignments.
if (BO->getOpcode() != BO_Assign)
return nullptr;
MemberExpr *ME = dyn_cast<MemberExpr>(BO->getLHS());
if (!ME)
return nullptr;
FieldDecl *Field = dyn_cast<FieldDecl>(ME->getMemberDecl());
if (!Field || !isMemcpyableField(Field))
return nullptr;
Stmt *RHS = BO->getRHS();
if (ImplicitCastExpr *EC = dyn_cast<ImplicitCastExpr>(RHS))
RHS = EC->getSubExpr();
if (!RHS)
return nullptr;
if (MemberExpr *ME2 = dyn_cast<MemberExpr>(RHS)) {
if (ME2->getMemberDecl() == Field)
return Field;
}
return nullptr;
} else if (CXXMemberCallExpr *MCE = dyn_cast<CXXMemberCallExpr>(S)) {
CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(MCE->getCalleeDecl());
if (!(MD && isMemcpyEquivalentSpecialMember(MD)))
return nullptr;
MemberExpr *IOA = dyn_cast<MemberExpr>(MCE->getImplicitObjectArgument());
if (!IOA)
return nullptr;
FieldDecl *Field = dyn_cast<FieldDecl>(IOA->getMemberDecl());
if (!Field || !isMemcpyableField(Field))
return nullptr;
MemberExpr *Arg0 = dyn_cast<MemberExpr>(MCE->getArg(0));
if (!Arg0 || Field != dyn_cast<FieldDecl>(Arg0->getMemberDecl()))
return nullptr;
return Field;
} else if (CallExpr *CE = dyn_cast<CallExpr>(S)) {
FunctionDecl *FD = dyn_cast<FunctionDecl>(CE->getCalleeDecl());
if (!FD || FD->getBuiltinID() != Builtin::BI__builtin_memcpy)
return nullptr;
Expr *DstPtr = CE->getArg(0);
if (ImplicitCastExpr *DC = dyn_cast<ImplicitCastExpr>(DstPtr))
DstPtr = DC->getSubExpr();
UnaryOperator *DUO = dyn_cast<UnaryOperator>(DstPtr);
if (!DUO || DUO->getOpcode() != UO_AddrOf)
return nullptr;
MemberExpr *ME = dyn_cast<MemberExpr>(DUO->getSubExpr());
if (!ME)
return nullptr;
FieldDecl *Field = dyn_cast<FieldDecl>(ME->getMemberDecl());
if (!Field || !isMemcpyableField(Field))
return nullptr;
Expr *SrcPtr = CE->getArg(1);
if (ImplicitCastExpr *SC = dyn_cast<ImplicitCastExpr>(SrcPtr))
SrcPtr = SC->getSubExpr();
UnaryOperator *SUO = dyn_cast<UnaryOperator>(SrcPtr);
if (!SUO || SUO->getOpcode() != UO_AddrOf)
return nullptr;
MemberExpr *ME2 = dyn_cast<MemberExpr>(SUO->getSubExpr());
if (!ME2 || Field != dyn_cast<FieldDecl>(ME2->getMemberDecl()))
return nullptr;
return Field;
}
return nullptr;
}
bool AssignmentsMemcpyable;
SmallVector<Stmt *, 16> AggregatedStmts;
public:
AssignmentMemcpyizer(CIRGenFunction &CGF, const CXXMethodDecl *AD,
FunctionArgList &Args)
: FieldMemcpyizer(CGF, AD->getParent(), Args[Args.size() - 1]),
AssignmentsMemcpyable(CGF.getLangOpts().getGC() == LangOptions::NonGC) {
assert(Args.size() == 2);
}
void emitAssignment(Stmt *S) {
FieldDecl *F = getMemcpyableField(S);
if (F) {
addMemcpyableField(F);
AggregatedStmts.push_back(S);
} else {
emitAggregatedStmts();
if (CGF.buildStmt(S, /*useCurrentScope=*/true).failed())
llvm_unreachable("Should not get here!");
}
}
void emitAggregatedStmts() {
if (AggregatedStmts.size() <= 1) {
if (!AggregatedStmts.empty()) {
CopyingValueRepresentation CVR(CGF);
if (CGF.buildStmt(AggregatedStmts[0], /*useCurrentScope=*/true)
.failed())
llvm_unreachable("Should not get here!");
}
reset();
}
buildMemcpy();
AggregatedStmts.clear();
}
void finish() { emitAggregatedStmts(); }
};
} // namespace
static bool isInitializerOfDynamicClass(const CXXCtorInitializer *BaseInit) {
const Type *BaseType = BaseInit->getBaseClass();
const auto *BaseClassDecl =
cast<CXXRecordDecl>(BaseType->castAs<RecordType>()->getDecl());
return BaseClassDecl->isDynamicClass();
}
namespace {
/// Call the destructor for a direct base class.
struct CallBaseDtor final : EHScopeStack::Cleanup {
const CXXRecordDecl *BaseClass;
bool BaseIsVirtual;
CallBaseDtor(const CXXRecordDecl *Base, bool BaseIsVirtual)
: BaseClass(Base), BaseIsVirtual(BaseIsVirtual) {}
void Emit(CIRGenFunction &CGF, Flags flags) override {
const CXXRecordDecl *DerivedClass =
cast<CXXMethodDecl>(CGF.CurCodeDecl)->getParent();
const CXXDestructorDecl *D = BaseClass->getDestructor();
// We are already inside a destructor, so presumably the object being
// destroyed should have the expected type.
QualType ThisTy = D->getFunctionObjectParameterType();
assert(CGF.currSrcLoc && "expected source location");
Address Addr = CGF.getAddressOfDirectBaseInCompleteClass(
*CGF.currSrcLoc, CGF.LoadCXXThisAddress(), DerivedClass, BaseClass,
BaseIsVirtual);
CGF.buildCXXDestructorCall(D, Dtor_Base, BaseIsVirtual,
/*Delegating=*/false, Addr, ThisTy);
}
};
/// A visitor which checks whether an initializer uses 'this' in a
/// way which requires the vtable to be properly set.
struct DynamicThisUseChecker
: ConstEvaluatedExprVisitor<DynamicThisUseChecker> {
typedef ConstEvaluatedExprVisitor<DynamicThisUseChecker> super;
bool UsesThis;
DynamicThisUseChecker(const ASTContext &C) : super(C), UsesThis(false) {}
// Black-list all explicit and implicit references to 'this'.
//
// Do we need to worry about external references to 'this' derived
// from arbitrary code? If so, then anything which runs arbitrary
// external code might potentially access the vtable.
void VisitCXXThisExpr(const CXXThisExpr *E) { UsesThis = true; }
};
} // end anonymous namespace
static bool BaseInitializerUsesThis(ASTContext &C, const Expr *Init) {
DynamicThisUseChecker Checker(C);
Checker.Visit(Init);
return Checker.UsesThis;
}
/// Gets the address of a direct base class within a complete object.
/// This should only be used for (1) non-virtual bases or (2) virtual bases
/// when the type is known to be complete (e.g. in complete destructors).
///
/// The object pointed to by 'This' is assumed to be non-null.
Address CIRGenFunction::getAddressOfDirectBaseInCompleteClass(
mlir::Location loc, Address This, const CXXRecordDecl *Derived,
const CXXRecordDecl *Base, bool BaseIsVirtual) {
// 'this' must be a pointer (in some address space) to Derived.
assert(This.getElementType() == ConvertType(Derived));
// Compute the offset of the virtual base.
CharUnits Offset;
const ASTRecordLayout &Layout = getContext().getASTRecordLayout(Derived);
if (BaseIsVirtual)
Offset = Layout.getVBaseClassOffset(Base);
else
Offset = Layout.getBaseClassOffset(Base);
// Shift and cast down to the base type.
// TODO: for complete types, this should be possible with a GEP.
Address V = This;
if (!Offset.isZero()) {
mlir::Value OffsetVal = builder.getSInt32(Offset.getQuantity(), loc);
mlir::Value VBaseThisPtr = builder.create<mlir::cir::PtrStrideOp>(
loc, This.getPointer().getType(), This.getPointer(), OffsetVal);
V = Address(VBaseThisPtr, CXXABIThisAlignment);
}
V = builder.createElementBitCast(loc, V, ConvertType(Base));
return V;
}
static void buildBaseInitializer(mlir::Location loc, CIRGenFunction &CGF,
const CXXRecordDecl *ClassDecl,
CXXCtorInitializer *BaseInit) {
assert(BaseInit->isBaseInitializer() && "Must have base initializer!");
Address ThisPtr = CGF.LoadCXXThisAddress();
const Type *BaseType = BaseInit->getBaseClass();
const auto *BaseClassDecl =
cast<CXXRecordDecl>(BaseType->castAs<RecordType>()->getDecl());
bool isBaseVirtual = BaseInit->isBaseVirtual();
// If the initializer for the base (other than the constructor
// itself) accesses 'this' in any way, we need to initialize the
// vtables.
if (BaseInitializerUsesThis(CGF.getContext(), BaseInit->getInit()))
CGF.initializeVTablePointers(loc, ClassDecl);
// We can pretend to be a complete class because it only matters for
// virtual bases, and we only do virtual bases for complete ctors.
Address V = CGF.getAddressOfDirectBaseInCompleteClass(
loc, ThisPtr, ClassDecl, BaseClassDecl, isBaseVirtual);
AggValueSlot AggSlot = AggValueSlot::forAddr(
V, Qualifiers(), AggValueSlot::IsDestructed,
AggValueSlot::DoesNotNeedGCBarriers, AggValueSlot::IsNotAliased,
CGF.getOverlapForBaseInit(ClassDecl, BaseClassDecl, isBaseVirtual));
CGF.buildAggExpr(BaseInit->getInit(), AggSlot);
if (CGF.CGM.getLangOpts().Exceptions &&
!BaseClassDecl->hasTrivialDestructor())
CGF.EHStack.pushCleanup<CallBaseDtor>(EHCleanup, BaseClassDecl,
isBaseVirtual);
}
/// This routine generates necessary code to initialize base classes and
/// non-static data members belonging to this constructor.
void CIRGenFunction::buildCtorPrologue(const CXXConstructorDecl *CD,
CXXCtorType CtorType,
FunctionArgList &Args) {
if (CD->isDelegatingConstructor())
return buildDelegatingCXXConstructorCall(CD, Args);
const CXXRecordDecl *ClassDecl = CD->getParent();
CXXConstructorDecl::init_const_iterator B = CD->init_begin(),
E = CD->init_end();
// Virtual base initializers first, if any. They aren't needed if:
// - This is a base ctor variant
// - There are no vbases
// - The class is abstract, so a complete object of it cannot be constructed
//
// The check for an abstract class is necessary because sema may not have
// marked virtual base destructors referenced.
bool ConstructVBases = CtorType != Ctor_Base &&
ClassDecl->getNumVBases() != 0 &&
!ClassDecl->isAbstract();
// In the Microsoft C++ ABI, there are no constructor variants. Instead, the
// constructor of a class with virtual bases takes an additional parameter to
// conditionally construct the virtual bases. Emit that check here.
mlir::Block *BaseCtorContinueBB = nullptr;
if (ConstructVBases &&
!CGM.getTarget().getCXXABI().hasConstructorVariants()) {
llvm_unreachable("NYI");
}
auto const OldThis = CXXThisValue;
for (; B != E && (*B)->isBaseInitializer() && (*B)->isBaseVirtual(); B++) {
if (!ConstructVBases)
continue;
if (CGM.getCodeGenOpts().StrictVTablePointers &&
CGM.getCodeGenOpts().OptimizationLevel > 0 &&
isInitializerOfDynamicClass(*B))
llvm_unreachable("NYI");
buildBaseInitializer(getLoc(CD->getBeginLoc()), *this, ClassDecl, *B);
}
if (BaseCtorContinueBB) {
llvm_unreachable("NYI");
}
// Then, non-virtual base initializers.
for (; B != E && (*B)->isBaseInitializer(); B++) {
assert(!(*B)->isBaseVirtual());
if (CGM.getCodeGenOpts().StrictVTablePointers &&
CGM.getCodeGenOpts().OptimizationLevel > 0 &&
isInitializerOfDynamicClass(*B))
llvm_unreachable("NYI");
buildBaseInitializer(getLoc(CD->getBeginLoc()), *this, ClassDecl, *B);
}
CXXThisValue = OldThis;
initializeVTablePointers(getLoc(CD->getBeginLoc()), ClassDecl);
// And finally, initialize class members.
FieldConstructionScope FCS(*this, LoadCXXThisAddress());
ConstructorMemcpyizer CM(*this, CD, Args);
for (; B != E; B++) {
CXXCtorInitializer *Member = (*B);
assert(!Member->isBaseInitializer());
assert(Member->isAnyMemberInitializer() &&
"Delegating initializer on non-delegating constructor");
CM.addMemberInitializer(Member);
}
CM.finish();
}
static Address ApplyNonVirtualAndVirtualOffset(
mlir::Location loc, CIRGenFunction &CGF, Address addr,
CharUnits nonVirtualOffset, mlir::Value virtualOffset,
const CXXRecordDecl *derivedClass, const CXXRecordDecl *nearestVBase) {
// Assert that we have something to do.
assert(!nonVirtualOffset.isZero() || virtualOffset != nullptr);
// Compute the offset from the static and dynamic components.
mlir::Value baseOffset;
if (!nonVirtualOffset.isZero()) {
mlir::Type OffsetType =
(CGF.CGM.getTarget().getCXXABI().isItaniumFamily() &&
CGF.CGM.getItaniumVTableContext().isRelativeLayout())
? CGF.SInt32Ty
: CGF.PtrDiffTy;
baseOffset = CGF.getBuilder().getConstInt(loc, OffsetType,
nonVirtualOffset.getQuantity());
if (virtualOffset) {
baseOffset = CGF.getBuilder().createBinop(
virtualOffset, mlir::cir::BinOpKind::Add, baseOffset);
}
} else {
baseOffset = virtualOffset;
}
// Apply the base offset.
mlir::Value ptr = addr.getPointer();
ptr = CGF.getBuilder().create<mlir::cir::PtrStrideOp>(loc, ptr.getType(), ptr,
baseOffset);
// If we have a virtual component, the alignment of the result will
// be relative only to the known alignment of that vbase.
CharUnits alignment;
if (virtualOffset) {
assert(nearestVBase && "virtual offset without vbase?");
llvm_unreachable("NYI");
// alignment = CGF.CGM.getVBaseAlignment(addr.getAlignment(),
// derivedClass, nearestVBase);
} else {
alignment = addr.getAlignment();
}
alignment = alignment.alignmentAtOffset(nonVirtualOffset);
return Address(ptr, alignment);
}
void CIRGenFunction::initializeVTablePointer(mlir::Location loc,
const VPtr &Vptr) {
// Compute the address point.
auto VTableAddressPoint = CGM.getCXXABI().getVTableAddressPointInStructor(
*this, Vptr.VTableClass, Vptr.Base, Vptr.NearestVBase);
if (!VTableAddressPoint)
return;
// Compute where to store the address point.
mlir::Value VirtualOffset{};
CharUnits NonVirtualOffset = CharUnits::Zero();
if (CGM.getCXXABI().isVirtualOffsetNeededForVTableField(*this, Vptr)) {
llvm_unreachable("NYI");
} else {
// We can just use the base offset in the complete class.
NonVirtualOffset = Vptr.Base.getBaseOffset();
}
// Apply the offsets.
Address VTableField = LoadCXXThisAddress();
if (!NonVirtualOffset.isZero() || VirtualOffset) {
VTableField = ApplyNonVirtualAndVirtualOffset(
loc, *this, VTableField, NonVirtualOffset, VirtualOffset,
Vptr.VTableClass, Vptr.NearestVBase);
}
// Finally, store the address point. Use the same CIR types as the field.
//
// vtable field is derived from `this` pointer, therefore they should be in
// the same addr space.
assert(!MissingFeatures::addressSpace());
VTableField = builder.createElementBitCast(loc, VTableField,
VTableAddressPoint.getType());
builder.createStore(loc, VTableAddressPoint, VTableField);
assert(!MissingFeatures::tbaa());
}
void CIRGenFunction::initializeVTablePointers(mlir::Location loc,
const CXXRecordDecl *RD) {
// Ignore classes without a vtable.
if (!RD->isDynamicClass())
return;
// Initialize the vtable pointers for this class and all of its bases.
if (CGM.getCXXABI().doStructorsInitializeVPtrs(RD))
for (const auto &Vptr : getVTablePointers(RD))
initializeVTablePointer(loc, Vptr);
if (RD->getNumVBases())
CGM.getCXXABI().initializeHiddenVirtualInheritanceMembers(*this, RD);
}
CIRGenFunction::VPtrsVector
CIRGenFunction::getVTablePointers(const CXXRecordDecl *VTableClass) {
CIRGenFunction::VPtrsVector VPtrsResult;
VisitedVirtualBasesSetTy VBases;
getVTablePointers(BaseSubobject(VTableClass, CharUnits::Zero()),
/*NearestVBase=*/nullptr,
/*OffsetFromNearestVBase=*/CharUnits::Zero(),
/*BaseIsNonVirtualPrimaryBase=*/false, VTableClass, VBases,
VPtrsResult);
return VPtrsResult;
}
void CIRGenFunction::getVTablePointers(BaseSubobject Base,
const CXXRecordDecl *NearestVBase,
CharUnits OffsetFromNearestVBase,
bool BaseIsNonVirtualPrimaryBase,
const CXXRecordDecl *VTableClass,
VisitedVirtualBasesSetTy &VBases,
VPtrsVector &Vptrs) {
// If this base is a non-virtual primary base the address point has already
// been set.
if (!BaseIsNonVirtualPrimaryBase) {
// Initialize the vtable pointer for this base.
VPtr Vptr = {Base, NearestVBase, OffsetFromNearestVBase, VTableClass};
Vptrs.push_back(Vptr);
}
const CXXRecordDecl *RD = Base.getBase();
// Traverse bases.
for (const auto &I : RD->bases()) {
auto *BaseDecl =
cast<CXXRecordDecl>(I.getType()->castAs<RecordType>()->getDecl());
// Ignore classes without a vtable.
if (!BaseDecl->isDynamicClass())
continue;
CharUnits BaseOffset;
CharUnits BaseOffsetFromNearestVBase;
bool BaseDeclIsNonVirtualPrimaryBase;
if (I.isVirtual()) {
llvm_unreachable("NYI");
} else {
const ASTRecordLayout &Layout = getContext().getASTRecordLayout(RD);
BaseOffset = Base.getBaseOffset() + Layout.getBaseClassOffset(BaseDecl);
BaseOffsetFromNearestVBase =
OffsetFromNearestVBase + Layout.getBaseClassOffset(BaseDecl);
BaseDeclIsNonVirtualPrimaryBase = Layout.getPrimaryBase() == BaseDecl;
}
getVTablePointers(
BaseSubobject(BaseDecl, BaseOffset),
I.isVirtual() ? BaseDecl : NearestVBase, BaseOffsetFromNearestVBase,
BaseDeclIsNonVirtualPrimaryBase, VTableClass, VBases, Vptrs);
}
}
Address CIRGenFunction::LoadCXXThisAddress() {
assert(CurFuncDecl && "loading 'this' without a func declaration?");
assert(isa<CXXMethodDecl>(CurFuncDecl));
// Lazily compute CXXThisAlignment.
if (CXXThisAlignment.isZero()) {
// Just use the best known alignment for the parent.
// TODO: if we're currently emitting a complete-object ctor/dtor, we can
// always use the complete-object alignment.
auto RD = cast<CXXMethodDecl>(CurFuncDecl)->getParent();
CXXThisAlignment = CGM.getClassPointerAlignment(RD);
}
return Address(LoadCXXThis(), CXXThisAlignment);
}
void CIRGenFunction::buildInitializerForField(FieldDecl *Field, LValue LHS,
Expr *Init) {
QualType FieldType = Field->getType();
switch (getEvaluationKind(FieldType)) {
case TEK_Scalar:
if (LHS.isSimple()) {
buildExprAsInit(Init, Field, LHS, false);
} else {
llvm_unreachable("NYI");
}
break;
case TEK_Complex:
llvm_unreachable("NYI");
break;
case TEK_Aggregate: {
AggValueSlot Slot = AggValueSlot::forLValue(
LHS, AggValueSlot::IsDestructed, AggValueSlot::DoesNotNeedGCBarriers,
AggValueSlot::IsNotAliased, getOverlapForFieldInit(Field),
AggValueSlot::IsNotZeroed,
// Checks are made by the code that calls constructor.
AggValueSlot::IsSanitizerChecked);
buildAggExpr(Init, Slot);
break;
}
}
// Ensure that we destroy this object if an exception is thrown later in the
// constructor.
QualType::DestructionKind dtorKind = FieldType.isDestructedType();
(void)dtorKind;
if (MissingFeatures::cleanups())
llvm_unreachable("NYI");
}
void CIRGenFunction::buildDelegateCXXConstructorCall(
const CXXConstructorDecl *Ctor, CXXCtorType CtorType,
const FunctionArgList &Args, SourceLocation Loc) {
CallArgList DelegateArgs;
FunctionArgList::const_iterator I = Args.begin(), E = Args.end();
assert(I != E && "no parameters to constructor");
// this
Address This = LoadCXXThisAddress();
DelegateArgs.add(RValue::get(This.getPointer()), (*I)->getType());
++I;
// FIXME: The location of the VTT parameter in the parameter list is specific
// to the Itanium ABI and shouldn't be hardcoded here.
if (CGM.getCXXABI().NeedsVTTParameter(CurGD)) {
llvm_unreachable("NYI");
}
// Explicit arguments.
for (; I != E; ++I) {
const VarDecl *param = *I;
// FIXME: per-argument source location
buildDelegateCallArg(DelegateArgs, param, Loc);
}
buildCXXConstructorCall(Ctor, CtorType, /*ForVirtualBase=*/false,
/*Delegating=*/true, This, DelegateArgs,
AggValueSlot::MayOverlap, Loc,
/*NewPointerIsChecked=*/true);
}
void CIRGenFunction::buildImplicitAssignmentOperatorBody(
FunctionArgList &Args) {
const CXXMethodDecl *AssignOp = cast<CXXMethodDecl>(CurGD.getDecl());
const Stmt *RootS = AssignOp->getBody();
assert(isa<CompoundStmt>(RootS) &&
"Body of an implicit assignment operator should be compound stmt.");
const CompoundStmt *RootCS = cast<CompoundStmt>(RootS);
// LexicalScope Scope(*this, RootCS->getSourceRange());
// FIXME(cir): add all of the below under a new scope.
assert(!MissingFeatures::incrementProfileCounter());
AssignmentMemcpyizer AM(*this, AssignOp, Args);
for (auto *I : RootCS->body())
AM.emitAssignment(I);
AM.finish();
}
void CIRGenFunction::buildForwardingCallToLambda(
const CXXMethodDecl *callOperator, CallArgList &callArgs) {
// Get the address of the call operator.
const auto &calleeFnInfo =
CGM.getTypes().arrangeCXXMethodDeclaration(callOperator);
auto calleePtr = CGM.GetAddrOfFunction(
GlobalDecl(callOperator), CGM.getTypes().GetFunctionType(calleeFnInfo));
// Prepare the return slot.
const FunctionProtoType *FPT =
callOperator->getType()->castAs<FunctionProtoType>();
QualType resultType = FPT->getReturnType();
ReturnValueSlot returnSlot;
if (!resultType->isVoidType() &&
calleeFnInfo.getReturnInfo().getKind() == ABIArgInfo::Indirect &&
!hasScalarEvaluationKind(calleeFnInfo.getReturnType())) {
llvm_unreachable("NYI");
}
// We don't need to separately arrange the call arguments because
// the call can't be variadic anyway --- it's impossible to forward
// variadic arguments.
// Now emit our call.
auto callee = CIRGenCallee::forDirect(calleePtr, GlobalDecl(callOperator));
RValue RV = buildCall(calleeFnInfo, callee, returnSlot, callArgs);
// If necessary, copy the returned value into the slot.
if (!resultType->isVoidType() && returnSlot.isNull()) {
if (getLangOpts().ObjCAutoRefCount && resultType->isObjCRetainableType())
llvm_unreachable("NYI");
buildReturnOfRValue(*currSrcLoc, RV, resultType);
} else {
llvm_unreachable("NYI");
}
}
void CIRGenFunction::buildLambdaDelegatingInvokeBody(const CXXMethodDecl *MD) {
const CXXRecordDecl *Lambda = MD->getParent();
// Start building arguments for forwarding call
CallArgList CallArgs;
QualType LambdaType = getContext().getRecordType(Lambda);
QualType ThisType = getContext().getPointerType(LambdaType);
Address ThisPtr =
CreateMemTemp(LambdaType, getLoc(MD->getSourceRange()), "unused.capture");
CallArgs.add(RValue::get(ThisPtr.getPointer()), ThisType);
// Add the rest of the parameters.
for (auto *Param : MD->parameters())
buildDelegateCallArg(CallArgs, Param, Param->getBeginLoc());
const CXXMethodDecl *CallOp = Lambda->getLambdaCallOperator();
// For a generic lambda, find the corresponding call operator specialization
// to which the call to the static-invoker shall be forwarded.
if (Lambda->isGenericLambda()) {
assert(MD->isFunctionTemplateSpecialization());
const TemplateArgumentList *TAL = MD->getTemplateSpecializationArgs();
FunctionTemplateDecl *CallOpTemplate =
CallOp->getDescribedFunctionTemplate();
void *InsertPos = nullptr;
FunctionDecl *CorrespondingCallOpSpecialization =
CallOpTemplate->findSpecialization(TAL->asArray(), InsertPos);
assert(CorrespondingCallOpSpecialization);
CallOp = cast<CXXMethodDecl>(CorrespondingCallOpSpecialization);
}
buildForwardingCallToLambda(CallOp, CallArgs);
}
void CIRGenFunction::buildLambdaStaticInvokeBody(const CXXMethodDecl *MD) {
if (MD->isVariadic()) {
// Codgen for LLVM doesn't emit code for this as well, it says:
// FIXME: Making this work correctly is nasty because it requires either
// cloning the body of the call operator or making the call operator
// forward.
llvm_unreachable("NYI");
}
buildLambdaDelegatingInvokeBody(MD);
}
void CIRGenFunction::destroyCXXObject(CIRGenFunction &CGF, Address addr,
QualType type) {
const RecordType *rtype = type->castAs<RecordType>();
const CXXRecordDecl *record = cast<CXXRecordDecl>(rtype->getDecl());
const CXXDestructorDecl *dtor = record->getDestructor();
// TODO(cir): Unlike traditional codegen, CIRGen should actually emit trivial
// dtors which shall be removed on later CIR passes. However, only remove this
// assertion once we get a testcase to exercise this path.
assert(!dtor->isTrivial());
CGF.buildCXXDestructorCall(dtor, Dtor_Complete, /*for vbase*/ false,
/*Delegating=*/false, addr, type);
}
static bool FieldHasTrivialDestructorBody(ASTContext &Context,
const FieldDecl *Field);
// FIXME(cir): this should be shared with traditional codegen.
static bool
HasTrivialDestructorBody(ASTContext &Context,
const CXXRecordDecl *BaseClassDecl,
const CXXRecordDecl *MostDerivedClassDecl) {
// If the destructor is trivial we don't have to check anything else.
if (BaseClassDecl->hasTrivialDestructor())
return true;
if (!BaseClassDecl->getDestructor()->hasTrivialBody())
return false;
// Check fields.
for (const auto *Field : BaseClassDecl->fields())
if (!FieldHasTrivialDestructorBody(Context, Field))
return false;
// Check non-virtual bases.
for (const auto &I : BaseClassDecl->bases()) {
if (I.isVirtual())
continue;
const CXXRecordDecl *NonVirtualBase =
cast<CXXRecordDecl>(I.getType()->castAs<RecordType>()->getDecl());
if (!HasTrivialDestructorBody(Context, NonVirtualBase,
MostDerivedClassDecl))
return false;
}
if (BaseClassDecl == MostDerivedClassDecl) {
// Check virtual bases.
for (const auto &I : BaseClassDecl->vbases()) {
const CXXRecordDecl *VirtualBase =
cast<CXXRecordDecl>(I.getType()->castAs<RecordType>()->getDecl());
if (!HasTrivialDestructorBody(Context, VirtualBase, MostDerivedClassDecl))
return false;
}
}
return true;
}
// FIXME(cir): this should be shared with traditional codegen.
static bool FieldHasTrivialDestructorBody(ASTContext &Context,
const FieldDecl *Field) {
QualType FieldBaseElementType = Context.getBaseElementType(Field->getType());
const RecordType *RT = FieldBaseElementType->getAs<RecordType>();
if (!RT)
return true;
CXXRecordDecl *FieldClassDecl = cast<CXXRecordDecl>(RT->getDecl());
// The destructor for an implicit anonymous union member is never invoked.
if (FieldClassDecl->isUnion() && FieldClassDecl->isAnonymousStructOrUnion())
return false;
return HasTrivialDestructorBody(Context, FieldClassDecl, FieldClassDecl);
}
/// Check whether we need to initialize any vtable pointers before calling this
/// destructor.
/// FIXME(cir): this should be shared with traditional codegen.
static bool CanSkipVTablePointerInitialization(CIRGenFunction &CGF,
const CXXDestructorDecl *Dtor) {
const CXXRecordDecl *ClassDecl = Dtor->getParent();
if (!ClassDecl->isDynamicClass())
return true;
// For a final class, the vtable pointer is known to already point to the
// class's vtable.
if (ClassDecl->isEffectivelyFinal())
return true;
if (!Dtor->hasTrivialBody())
return false;
// Check the fields.
for (const auto *Field : ClassDecl->fields())
if (!FieldHasTrivialDestructorBody(CGF.getContext(), Field))
return false;
return true;
}
/// Emits the body of the current destructor.
void CIRGenFunction::buildDestructorBody(FunctionArgList &Args) {
const CXXDestructorDecl *Dtor = cast<CXXDestructorDecl>(CurGD.getDecl());
CXXDtorType DtorType = CurGD.getDtorType();
// For an abstract class, non-base destructors are never used (and can't
// be emitted in general, because vbase dtors may not have been validated
// by Sema), but the Itanium ABI doesn't make them optional and Clang may
// in fact emit references to them from other compilations, so emit them
// as functions containing a trap instruction.
if (DtorType != Dtor_Base && Dtor->getParent()->isAbstract()) {
SourceLocation Loc =
Dtor->hasBody() ? Dtor->getBody()->getBeginLoc() : Dtor->getLocation();
builder.create<mlir::cir::TrapOp>(getLoc(Loc));
// The corresponding clang/CodeGen logic clears the insertion point here,
// but MLIR's builder requires a valid insertion point, so we create a dummy
// block (since the trap is a block terminator).
builder.createBlock(builder.getBlock()->getParent());
return;
}
Stmt *Body = Dtor->getBody();
if (Body)
assert(!MissingFeatures::incrementProfileCounter());
// The call to operator delete in a deleting destructor happens
// outside of the function-try-block, which means it's always
// possible to delegate the destructor body to the complete
// destructor. Do so.
if (DtorType == Dtor_Deleting) {
RunCleanupsScope DtorEpilogue(*this);
EnterDtorCleanups(Dtor, Dtor_Deleting);
if (HaveInsertPoint()) {
QualType ThisTy = Dtor->getFunctionObjectParameterType();
buildCXXDestructorCall(Dtor, Dtor_Complete, /*ForVirtualBase=*/false,
/*Delegating=*/false, LoadCXXThisAddress(),
ThisTy);
}
return;
}
// If the body is a function-try-block, enter the try before
// anything else.
bool isTryBody = (Body && isa<CXXTryStmt>(Body));
if (isTryBody) {
llvm_unreachable("NYI");
// EnterCXXTryStmt(*cast<CXXTryStmt>(Body), true);
}
if (MissingFeatures::emitAsanPrologueOrEpilogue())
llvm_unreachable("NYI");
// Enter the epilogue cleanups.
RunCleanupsScope DtorEpilogue(*this);
// If this is the complete variant, just invoke the base variant;
// the epilogue will destruct the virtual bases. But we can't do
// this optimization if the body is a function-try-block, because
// we'd introduce *two* handler blocks. In the Microsoft ABI, we
// always delegate because we might not have a definition in this TU.
switch (DtorType) {
case Dtor_Comdat:
llvm_unreachable("not expecting a COMDAT");
case Dtor_Deleting:
llvm_unreachable("already handled deleting case");
case Dtor_Complete:
assert((Body || getTarget().getCXXABI().isMicrosoft()) &&
"can't emit a dtor without a body for non-Microsoft ABIs");
// Enter the cleanup scopes for virtual bases.
EnterDtorCleanups(Dtor, Dtor_Complete);
if (!isTryBody) {
QualType ThisTy = Dtor->getFunctionObjectParameterType();
buildCXXDestructorCall(Dtor, Dtor_Base, /*ForVirtualBase=*/false,
/*Delegating=*/false, LoadCXXThisAddress(),
ThisTy);
break;
}
// Fallthrough: act like we're in the base variant.
[[fallthrough]];
case Dtor_Base:
assert(Body);
// Enter the cleanup scopes for fields and non-virtual bases.
EnterDtorCleanups(Dtor, Dtor_Base);
// Initialize the vtable pointers before entering the body.
if (!CanSkipVTablePointerInitialization(*this, Dtor)) {
// Insert the llvm.launder.invariant.group intrinsic before initializing
// the vptrs to cancel any previous assumptions we might have made.
if (CGM.getCodeGenOpts().StrictVTablePointers &&
CGM.getCodeGenOpts().OptimizationLevel > 0)
llvm_unreachable("NYI");
llvm_unreachable("NYI");
}
if (isTryBody)
llvm_unreachable("NYI");
else if (Body)
(void)buildStmt(Body, /*useCurrentScope=*/true);
else {
assert(Dtor->isImplicit() && "bodyless dtor not implicit");
// nothing to do besides what's in the epilogue
}
// -fapple-kext must inline any call to this dtor into
// the caller's body.
if (getLangOpts().AppleKext)
llvm_unreachable("NYI");
break;
}
// Jump out through the epilogue cleanups.
DtorEpilogue.ForceCleanup();
// Exit the try if applicable.
if (isTryBody)
llvm_unreachable("NYI");
}
namespace {
[[maybe_unused]] mlir::Value
LoadThisForDtorDelete(CIRGenFunction &CGF, const CXXDestructorDecl *DD) {
if (Expr *ThisArg = DD->getOperatorDeleteThisArg())
return CGF.buildScalarExpr(ThisArg);
return CGF.LoadCXXThis();
}
/// Call the operator delete associated with the current destructor.
struct CallDtorDelete final : EHScopeStack::Cleanup {
CallDtorDelete() {}
void Emit(CIRGenFunction &CGF, Flags flags) override {
const CXXDestructorDecl *Dtor = cast<CXXDestructorDecl>(CGF.CurCodeDecl);
const CXXRecordDecl *ClassDecl = Dtor->getParent();
CGF.buildDeleteCall(Dtor->getOperatorDelete(),
LoadThisForDtorDelete(CGF, Dtor),
CGF.getContext().getTagDeclType(ClassDecl));
}
};
} // namespace
class DestroyField final : public EHScopeStack::Cleanup {
const FieldDecl *field;
CIRGenFunction::Destroyer *destroyer;
bool useEHCleanupForArray;
public:
DestroyField(const FieldDecl *field, CIRGenFunction::Destroyer *destroyer,
bool useEHCleanupForArray)
: field(field), destroyer(destroyer),
useEHCleanupForArray(useEHCleanupForArray) {}
void Emit(CIRGenFunction &CGF, Flags flags) override {
// Find the address of the field.
Address thisValue = CGF.LoadCXXThisAddress();
QualType RecordTy = CGF.getContext().getTagDeclType(field->getParent());
LValue ThisLV = CGF.makeAddrLValue(thisValue, RecordTy);
LValue LV = CGF.buildLValueForField(ThisLV, field);
assert(LV.isSimple());
CGF.emitDestroy(LV.getAddress(), field->getType(), destroyer,
flags.isForNormalCleanup() && useEHCleanupForArray);
}
};
/// Emit all code that comes at the end of class's destructor. This is to call
/// destructors on members and base classes in reverse order of their
/// construction.
///
/// For a deleting destructor, this also handles the case where a destroying
/// operator delete completely overrides the definition.
void CIRGenFunction::EnterDtorCleanups(const CXXDestructorDecl *DD,
CXXDtorType DtorType) {
assert((!DD->isTrivial() || DD->hasAttr<DLLExportAttr>()) &&
"Should not emit dtor epilogue for non-exported trivial dtor!");
// The deleting-destructor phase just needs to call the appropriate
// operator delete that Sema picked up.
if (DtorType == Dtor_Deleting) {
assert(DD->getOperatorDelete() &&
"operator delete missing - EnterDtorCleanups");
if (CXXStructorImplicitParamValue) {
llvm_unreachable("NYI");
} else {
if (DD->getOperatorDelete()->isDestroyingOperatorDelete()) {
llvm_unreachable("NYI");
} else {
EHStack.pushCleanup<CallDtorDelete>(NormalAndEHCleanup);
}
}
return;
}
const CXXRecordDecl *ClassDecl = DD->getParent();
// Unions have no bases and do not call field destructors.
if (ClassDecl->isUnion())
return;
// The complete-destructor phase just destructs all the virtual bases.
if (DtorType == Dtor_Complete) {
// Poison the vtable pointer such that access after the base
// and member destructors are invoked is invalid.
if (CGM.getCodeGenOpts().SanitizeMemoryUseAfterDtor &&
SanOpts.has(SanitizerKind::Memory) && ClassDecl->getNumVBases() &&
ClassDecl->isPolymorphic())
assert(!MissingFeatures::sanitizeDtor());
// We push them in the forward order so that they'll be popped in
// the reverse order.
for (const auto &Base : ClassDecl->vbases()) {
auto *BaseClassDecl =
cast<CXXRecordDecl>(Base.getType()->castAs<RecordType>()->getDecl());
if (BaseClassDecl->hasTrivialDestructor()) {
// Under SanitizeMemoryUseAfterDtor, poison the trivial base class
// memory. For non-trival base classes the same is done in the class
// destructor.
assert(!MissingFeatures::sanitizeDtor());
} else {
EHStack.pushCleanup<CallBaseDtor>(NormalAndEHCleanup, BaseClassDecl,
/*BaseIsVirtual*/ true);
}
}
return;
}
assert(DtorType == Dtor_Base);
// Poison the vtable pointer if it has no virtual bases, but inherits
// virtual functions.
if (CGM.getCodeGenOpts().SanitizeMemoryUseAfterDtor &&
SanOpts.has(SanitizerKind::Memory) && !ClassDecl->getNumVBases() &&
ClassDecl->isPolymorphic())
assert(!MissingFeatures::sanitizeDtor());
// Destroy non-virtual bases.
for (const auto &Base : ClassDecl->bases()) {
// Ignore virtual bases.
if (Base.isVirtual())
continue;
CXXRecordDecl *BaseClassDecl = Base.getType()->getAsCXXRecordDecl();
if (BaseClassDecl->hasTrivialDestructor()) {
if (CGM.getCodeGenOpts().SanitizeMemoryUseAfterDtor &&
SanOpts.has(SanitizerKind::Memory) && !BaseClassDecl->isEmpty())
assert(!MissingFeatures::sanitizeDtor());
} else {
EHStack.pushCleanup<CallBaseDtor>(NormalAndEHCleanup, BaseClassDecl,
/*BaseIsVirtual*/ false);
}
}
// Poison fields such that access after their destructors are
// invoked, and before the base class destructor runs, is invalid.
bool SanitizeFields = CGM.getCodeGenOpts().SanitizeMemoryUseAfterDtor &&
SanOpts.has(SanitizerKind::Memory);
assert(!MissingFeatures::sanitizeDtor());
// Destroy direct fields.
for (const auto *Field : ClassDecl->fields()) {
if (SanitizeFields)
assert(!MissingFeatures::sanitizeDtor());
QualType type = Field->getType();
QualType::DestructionKind dtorKind = type.isDestructedType();
if (!dtorKind)
continue;
// Anonymous union members do not have their destructors called.
const RecordType *RT = type->getAsUnionType();
if (RT && RT->getDecl()->isAnonymousStructOrUnion())
continue;
CleanupKind cleanupKind = getCleanupKind(dtorKind);
EHStack.pushCleanup<DestroyField>(
cleanupKind, Field, getDestroyer(dtorKind), cleanupKind & EHCleanup);
}
if (SanitizeFields)
assert(!MissingFeatures::sanitizeDtor());
}
namespace {
struct CallDelegatingCtorDtor final : EHScopeStack::Cleanup {
const CXXDestructorDecl *Dtor;
Address Addr;
CXXDtorType Type;
CallDelegatingCtorDtor(const CXXDestructorDecl *D, Address Addr,
CXXDtorType Type)
: Dtor(D), Addr(Addr), Type(Type) {}
void Emit(CIRGenFunction &CGF, Flags flags) override {
// We are calling the destructor from within the constructor.
// Therefore, "this" should have the expected type.
QualType ThisTy = Dtor->getFunctionObjectParameterType();
CGF.buildCXXDestructorCall(Dtor, Type, /*ForVirtualBase=*/false,
/*Delegating=*/true, Addr, ThisTy);
}
};
} // end anonymous namespace
void CIRGenFunction::buildDelegatingCXXConstructorCall(
const CXXConstructorDecl *Ctor, const FunctionArgList &Args) {
assert(Ctor->isDelegatingConstructor());
Address ThisPtr = LoadCXXThisAddress();
AggValueSlot AggSlot = AggValueSlot::forAddr(
ThisPtr, Qualifiers(), AggValueSlot::IsDestructed,
AggValueSlot::DoesNotNeedGCBarriers, AggValueSlot::IsNotAliased,
AggValueSlot::MayOverlap, AggValueSlot::IsNotZeroed,
// Checks are made by the code that calls constructor.
AggValueSlot::IsSanitizerChecked);
buildAggExpr(Ctor->init_begin()[0]->getInit(), AggSlot);
const CXXRecordDecl *ClassDecl = Ctor->getParent();
if (CGM.getLangOpts().Exceptions && !ClassDecl->hasTrivialDestructor()) {
CXXDtorType Type =
CurGD.getCtorType() == Ctor_Complete ? Dtor_Complete : Dtor_Base;
EHStack.pushCleanup<CallDelegatingCtorDtor>(
EHCleanup, ClassDecl->getDestructor(), ThisPtr, Type);
}
}
void CIRGenFunction::buildCXXDestructorCall(const CXXDestructorDecl *DD,
CXXDtorType Type,
bool ForVirtualBase,
bool Delegating, Address This,
QualType ThisTy) {
CGM.getCXXABI().buildDestructorCall(*this, DD, Type, ForVirtualBase,
Delegating, This, ThisTy);
}
mlir::Value CIRGenFunction::GetVTTParameter(GlobalDecl GD, bool ForVirtualBase,
bool Delegating) {
if (!CGM.getCXXABI().NeedsVTTParameter(GD)) {
// This constructor/destructor does not need a VTT parameter.
return nullptr;
}
const CXXRecordDecl *RD = cast<CXXMethodDecl>(CurCodeDecl)->getParent();
const CXXRecordDecl *Base = cast<CXXMethodDecl>(GD.getDecl())->getParent();
if (Delegating) {
llvm_unreachable("NYI");
} else if (RD == Base) {
llvm_unreachable("NYI");
} else {
llvm_unreachable("NYI");
}
if (CGM.getCXXABI().NeedsVTTParameter(CurGD)) {
llvm_unreachable("NYI");
} else {
llvm_unreachable("NYI");
}
}
Address
CIRGenFunction::getAddressOfBaseClass(Address Value,
const CXXRecordDecl *Derived,
CastExpr::path_const_iterator PathBegin,
CastExpr::path_const_iterator PathEnd,
bool NullCheckValue, SourceLocation Loc) {
assert(PathBegin != PathEnd && "Base path should not be empty!");
CastExpr::path_const_iterator Start = PathBegin;
const CXXRecordDecl *VBase = nullptr;
// Sema has done some convenient canonicalization here: if the
// access path involved any virtual steps, the conversion path will
// *start* with a step down to the correct virtual base subobject,
// and hence will not require any further steps.
if ((*Start)->isVirtual()) {
llvm_unreachable("NYI");
}
// Compute the static offset of the ultimate destination within its
// allocating subobject (the virtual base, if there is one, or else
// the "complete" object that we see).
CharUnits NonVirtualOffset = CGM.computeNonVirtualBaseClassOffset(
VBase ? VBase : Derived, Start, PathEnd);
// If there's a virtual step, we can sometimes "devirtualize" it.
// For now, that's limited to when the derived type is final.
// TODO: "devirtualize" this for accesses to known-complete objects.
if (VBase && Derived->hasAttr<FinalAttr>()) {
llvm_unreachable("NYI");
}
// Get the base pointer type.
auto BaseValueTy = convertType((PathEnd[-1])->getType());
assert(!MissingFeatures::addressSpace());
// auto BasePtrTy = builder.getPointerTo(BaseValueTy);
// QualType DerivedTy = getContext().getRecordType(Derived);
// CharUnits DerivedAlign = CGM.getClassPointerAlignment(Derived);
// If the static offset is zero and we don't have a virtual step,
// just do a bitcast; null checks are unnecessary.
if (NonVirtualOffset.isZero() && !VBase) {
if (sanitizePerformTypeCheck()) {
llvm_unreachable("NYI");
}
return builder.createBaseClassAddr(getLoc(Loc), Value, BaseValueTy);
}
// Skip over the offset (and the vtable load) if we're supposed to
// null-check the pointer.
if (NullCheckValue) {
llvm_unreachable("NYI");
}
if (sanitizePerformTypeCheck()) {
llvm_unreachable("NYI");
}
// Compute the virtual offset.
mlir::Value VirtualOffset{};
if (VBase) {
llvm_unreachable("NYI");
}
// Apply both offsets.
Value = ApplyNonVirtualAndVirtualOffset(getLoc(Loc), *this, Value,
NonVirtualOffset, VirtualOffset,
Derived, VBase);
// Cast to the destination type.
Value = builder.createElementBitCast(Value.getPointer().getLoc(), Value,
BaseValueTy);
// Build a phi if we needed a null check.
if (NullCheckValue) {
llvm_unreachable("NYI");
}
llvm_unreachable("NYI");
return Value;
}
// TODO(cir): this can be shared with LLVM codegen.
bool CIRGenFunction::shouldEmitVTableTypeCheckedLoad(const CXXRecordDecl *RD) {
if (!CGM.getCodeGenOpts().WholeProgramVTables ||
!CGM.HasHiddenLTOVisibility(RD))
return false;
if (CGM.getCodeGenOpts().VirtualFunctionElimination)
return true;
if (!SanOpts.has(SanitizerKind::CFIVCall) ||
!CGM.getCodeGenOpts().SanitizeTrap.has(SanitizerKind::CFIVCall))
return false;
std::string TypeName = RD->getQualifiedNameAsString();
return !getContext().getNoSanitizeList().containsType(SanitizerKind::CFIVCall,
TypeName);
}
void CIRGenFunction::buildTypeMetadataCodeForVCall(const CXXRecordDecl *RD,
mlir::Value VTable,
SourceLocation Loc) {
if (SanOpts.has(SanitizerKind::CFIVCall)) {
llvm_unreachable("NYI");
} else if (CGM.getCodeGenOpts().WholeProgramVTables &&
// Don't insert type test assumes if we are forcing public
// visibility.
!CGM.AlwaysHasLTOVisibilityPublic(RD)) {
llvm_unreachable("NYI");
}
}
mlir::Value CIRGenFunction::getVTablePtr(mlir::Location Loc, Address This,
mlir::Type VTableTy,
const CXXRecordDecl *RD) {
Address VTablePtrSrc = builder.createElementBitCast(Loc, This, VTableTy);
auto VTable = builder.createLoad(Loc, VTablePtrSrc);
assert(!MissingFeatures::tbaa());
if (CGM.getCodeGenOpts().OptimizationLevel > 0 &&
CGM.getCodeGenOpts().StrictVTablePointers) {
assert(!MissingFeatures::createInvariantGroup());
}
return VTable;
}
Address CIRGenFunction::buildCXXMemberDataPointerAddress(
const Expr *E, Address base, mlir::Value memberPtr,
const MemberPointerType *memberPtrType, LValueBaseInfo *baseInfo) {
assert(!MissingFeatures::cxxABI());
auto op = builder.createGetIndirectMember(getLoc(E->getSourceRange()),
base.getPointer(), memberPtr);
QualType memberType = memberPtrType->getPointeeType();
CharUnits memberAlign = CGM.getNaturalTypeAlignment(memberType, baseInfo);
memberAlign = CGM.getDynamicOffsetAlignment(
base.getAlignment(), memberPtrType->getClass()->getAsCXXRecordDecl(),
memberAlign);
return Address(op, convertTypeForMem(memberPtrType->getPointeeType()),
memberAlign);
}
clang::CharUnits
CIRGenModule::getDynamicOffsetAlignment(clang::CharUnits actualBaseAlign,
const clang::CXXRecordDecl *baseDecl,
clang::CharUnits expectedTargetAlign) {
// If the base is an incomplete type (which is, alas, possible with
// member pointers), be pessimistic.
if (!baseDecl->isCompleteDefinition())
return std::min(actualBaseAlign, expectedTargetAlign);
auto &baseLayout = getASTContext().getASTRecordLayout(baseDecl);
CharUnits expectedBaseAlign = baseLayout.getNonVirtualAlignment();
// If the class is properly aligned, assume the target offset is, too.
//
// This actually isn't necessarily the right thing to do --- if the
// class is a complete object, but it's only properly aligned for a
// base subobject, then the alignments of things relative to it are
// probably off as well. (Note that this requires the alignment of
// the target to be greater than the NV alignment of the derived
// class.)
//
// However, our approach to this kind of under-alignment can only
// ever be best effort; after all, we're never going to propagate
// alignments through variables or parameters. Note, in particular,
// that constructing a polymorphic type in an address that's less
// than pointer-aligned will generally trap in the constructor,
// unless we someday add some sort of attribute to change the
// assumed alignment of 'this'. So our goal here is pretty much
// just to allow the user to explicitly say that a pointer is
// under-aligned and then safely access its fields and vtables.
if (actualBaseAlign >= expectedBaseAlign) {
return expectedTargetAlign;
}
// Otherwise, we might be offset by an arbitrary multiple of the
// actual alignment. The correct adjustment is to take the min of
// the two alignments.
return std::min(actualBaseAlign, expectedTargetAlign);
}
/// Emit a loop to call a particular constructor for each of several members of
/// an array.
///
/// \param ctor the constructor to call for each element
/// \param arrayType the type of the array to initialize
/// \param arrayBegin an arrayType*
/// \param zeroInitialize true if each element should be
/// zero-initialized before it is constructed
void CIRGenFunction::buildCXXAggrConstructorCall(
const CXXConstructorDecl *ctor, const clang::ArrayType *arrayType,
Address arrayBegin, const CXXConstructExpr *E, bool NewPointerIsChecked,
bool zeroInitialize) {
QualType elementType;
auto numElements = buildArrayLength(arrayType, elementType, arrayBegin);
buildCXXAggrConstructorCall(ctor, numElements, arrayBegin, E,
NewPointerIsChecked, zeroInitialize);
}
/// Emit a loop to call a particular constructor for each of several members of
/// an array.
///
/// \param ctor the constructor to call for each element
/// \param numElements the number of elements in the array;
/// may be zero
/// \param arrayBase a T*, where T is the type constructed by ctor
/// \param zeroInitialize true if each element should be
/// zero-initialized before it is constructed
void CIRGenFunction::buildCXXAggrConstructorCall(
const CXXConstructorDecl *ctor, mlir::Value numElements, Address arrayBase,
const CXXConstructExpr *E, bool NewPointerIsChecked, bool zeroInitialize) {
// It's legal for numElements to be zero. This can happen both
// dynamically, because x can be zero in 'new A[x]', and statically,
// because of GCC extensions that permit zero-length arrays. There
// are probably legitimate places where we could assume that this
// doesn't happen, but it's not clear that it's worth it.
// llvm::BranchInst *zeroCheckBranch = nullptr;
// Optimize for a constant count.
auto constantCount =
dyn_cast<mlir::cir::ConstantOp>(numElements.getDefiningOp());
if (constantCount) {
auto constIntAttr =
mlir::dyn_cast<mlir::cir::IntAttr>(constantCount.getValue());
// Just skip out if the constant count is zero.
if (constIntAttr && constIntAttr.getUInt() == 0)
return;
// Otherwise, emit the check.
} else {
llvm_unreachable("NYI");
}
auto arrayTy =
mlir::dyn_cast<mlir::cir::ArrayType>(arrayBase.getElementType());
assert(arrayTy && "expected array type");
auto elementType = arrayTy.getEltType();
auto ptrToElmType = builder.getPointerTo(elementType);
// Tradional LLVM codegen emits a loop here.
// TODO(cir): Lower to a loop as part of LoweringPrepare.
// The alignment of the base, adjusted by the size of a single element,
// provides a conservative estimate of the alignment of every element.
// (This assumes we never start tracking offsetted alignments.)
//
// Note that these are complete objects and so we don't need to
// use the non-virtual size or alignment.
QualType type = getContext().getTypeDeclType(ctor->getParent());
CharUnits eltAlignment = arrayBase.getAlignment().alignmentOfArrayElement(
getContext().getTypeSizeInChars(type));
// Zero initialize the storage, if requested.
if (zeroInitialize) {
llvm_unreachable("NYI");
}
// C++ [class.temporary]p4:
// There are two contexts in which temporaries are destroyed at a different
// point than the end of the full-expression. The first context is when a
// default constructor is called to initialize an element of an array.
// If the constructor has one or more default arguments, the destruction of
// every temporary created in a default argument expression is sequenced
// before the construction of the next array element, if any.
{
RunCleanupsScope Scope(*this);
// Evaluate the constructor and its arguments in a regular
// partial-destroy cleanup.
if (getLangOpts().Exceptions &&
!ctor->getParent()->hasTrivialDestructor()) {
llvm_unreachable("NYI");
}
// Wmit the constructor call that will execute for every array element.
builder.create<mlir::cir::ArrayCtor>(
*currSrcLoc, arrayBase.getPointer(),
[&](mlir::OpBuilder &b, mlir::Location loc) {
auto arg = b.getInsertionBlock()->addArgument(ptrToElmType, loc);
Address curAddr = Address(arg, ptrToElmType, eltAlignment);
auto currAVS = AggValueSlot::forAddr(
curAddr, type.getQualifiers(), AggValueSlot::IsDestructed,
AggValueSlot::DoesNotNeedGCBarriers, AggValueSlot::IsNotAliased,
AggValueSlot::DoesNotOverlap, AggValueSlot::IsNotZeroed,
NewPointerIsChecked ? AggValueSlot::IsSanitizerChecked
: AggValueSlot::IsNotSanitizerChecked);
buildCXXConstructorCall(ctor, Ctor_Complete, /*ForVirtualBase=*/false,
/*Delegating=*/false, currAVS, E);
builder.create<mlir::cir::YieldOp>(loc);
});
}
if (constantCount.use_empty())
constantCount.erase();
}