1 //===--- CGExprCXX.cpp - Emit LLVM Code for C++ expressions ---------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This contains code dealing with code generation of C++ expressions
12 //===----------------------------------------------------------------------===//
14 #include "CodeGenFunction.h"
15 #include "CGCUDARuntime.h"
17 #include "CGDebugInfo.h"
18 #include "CGObjCRuntime.h"
19 #include "clang/CodeGen/CGFunctionInfo.h"
20 #include "clang/Frontend/CodeGenOptions.h"
21 #include "llvm/IR/CallSite.h"
22 #include "llvm/IR/Intrinsics.h"
24 using namespace clang;
25 using namespace CodeGen;
28 commonEmitCXXMemberOrOperatorCall(CodeGenFunction &CGF, const CXXMethodDecl *MD,
29 llvm::Value *This, llvm::Value *ImplicitParam,
30 QualType ImplicitParamTy, const CallExpr *CE,
31 CallArgList &Args, CallArgList *RtlArgs) {
32 assert(CE == nullptr || isa<CXXMemberCallExpr>(CE) ||
33 isa<CXXOperatorCallExpr>(CE));
34 assert(MD->isInstance() &&
35 "Trying to emit a member or operator call expr on a static method!");
36 ASTContext &C = CGF.getContext();
39 const CXXRecordDecl *RD =
40 CGF.CGM.getCXXABI().getThisArgumentTypeForMethod(MD);
41 Args.add(RValue::get(This),
42 RD ? C.getPointerType(C.getTypeDeclType(RD)) : C.VoidPtrTy);
44 // If there is an implicit parameter (e.g. VTT), emit it.
46 Args.add(RValue::get(ImplicitParam), ImplicitParamTy);
49 const FunctionProtoType *FPT = MD->getType()->castAs<FunctionProtoType>();
50 RequiredArgs required = RequiredArgs::forPrototypePlus(FPT, Args.size(), MD);
52 // And the rest of the call args.
54 // Special case: if the caller emitted the arguments right-to-left already
55 // (prior to emitting the *this argument), we're done. This happens for
56 // assignment operators.
57 Args.addFrom(*RtlArgs);
59 // Special case: skip first argument of CXXOperatorCall (it is "this").
60 unsigned ArgsToSkip = isa<CXXOperatorCallExpr>(CE) ? 1 : 0;
61 CGF.EmitCallArgs(Args, FPT, drop_begin(CE->arguments(), ArgsToSkip),
62 CE->getDirectCallee());
65 FPT->getNumParams() == 0 &&
66 "No CallExpr specified for function with non-zero number of arguments");
71 RValue CodeGenFunction::EmitCXXMemberOrOperatorCall(
72 const CXXMethodDecl *MD, const CGCallee &Callee,
73 ReturnValueSlot ReturnValue,
74 llvm::Value *This, llvm::Value *ImplicitParam, QualType ImplicitParamTy,
75 const CallExpr *CE, CallArgList *RtlArgs) {
76 const FunctionProtoType *FPT = MD->getType()->castAs<FunctionProtoType>();
78 RequiredArgs required = commonEmitCXXMemberOrOperatorCall(
79 *this, MD, This, ImplicitParam, ImplicitParamTy, CE, Args, RtlArgs);
80 auto &FnInfo = CGM.getTypes().arrangeCXXMethodCall(Args, FPT, required);
81 return EmitCall(FnInfo, Callee, ReturnValue, Args);
84 RValue CodeGenFunction::EmitCXXDestructorCall(
85 const CXXDestructorDecl *DD, const CGCallee &Callee, llvm::Value *This,
86 llvm::Value *ImplicitParam, QualType ImplicitParamTy, const CallExpr *CE,
89 commonEmitCXXMemberOrOperatorCall(*this, DD, This, ImplicitParam,
90 ImplicitParamTy, CE, Args, nullptr);
91 return EmitCall(CGM.getTypes().arrangeCXXStructorDeclaration(DD, Type),
92 Callee, ReturnValueSlot(), Args);
95 RValue CodeGenFunction::EmitCXXPseudoDestructorExpr(
96 const CXXPseudoDestructorExpr *E) {
97 QualType DestroyedType = E->getDestroyedType();
98 if (DestroyedType.hasStrongOrWeakObjCLifetime()) {
99 // Automatic Reference Counting:
100 // If the pseudo-expression names a retainable object with weak or
101 // strong lifetime, the object shall be released.
102 Expr *BaseExpr = E->getBase();
103 Address BaseValue = Address::invalid();
104 Qualifiers BaseQuals;
106 // If this is s.x, emit s as an lvalue. If it is s->x, emit s as a scalar.
108 BaseValue = EmitPointerWithAlignment(BaseExpr);
109 const PointerType *PTy = BaseExpr->getType()->getAs<PointerType>();
110 BaseQuals = PTy->getPointeeType().getQualifiers();
112 LValue BaseLV = EmitLValue(BaseExpr);
113 BaseValue = BaseLV.getAddress();
114 QualType BaseTy = BaseExpr->getType();
115 BaseQuals = BaseTy.getQualifiers();
118 switch (DestroyedType.getObjCLifetime()) {
119 case Qualifiers::OCL_None:
120 case Qualifiers::OCL_ExplicitNone:
121 case Qualifiers::OCL_Autoreleasing:
124 case Qualifiers::OCL_Strong:
125 EmitARCRelease(Builder.CreateLoad(BaseValue,
126 DestroyedType.isVolatileQualified()),
130 case Qualifiers::OCL_Weak:
131 EmitARCDestroyWeak(BaseValue);
135 // C++ [expr.pseudo]p1:
136 // The result shall only be used as the operand for the function call
137 // operator (), and the result of such a call has type void. The only
138 // effect is the evaluation of the postfix-expression before the dot or
140 EmitIgnoredExpr(E->getBase());
143 return RValue::get(nullptr);
146 static CXXRecordDecl *getCXXRecord(const Expr *E) {
147 QualType T = E->getType();
148 if (const PointerType *PTy = T->getAs<PointerType>())
149 T = PTy->getPointeeType();
150 const RecordType *Ty = T->castAs<RecordType>();
151 return cast<CXXRecordDecl>(Ty->getDecl());
154 // Note: This function also emit constructor calls to support a MSVC
155 // extensions allowing explicit constructor function call.
156 RValue CodeGenFunction::EmitCXXMemberCallExpr(const CXXMemberCallExpr *CE,
157 ReturnValueSlot ReturnValue) {
158 const Expr *callee = CE->getCallee()->IgnoreParens();
160 if (isa<BinaryOperator>(callee))
161 return EmitCXXMemberPointerCallExpr(CE, ReturnValue);
163 const MemberExpr *ME = cast<MemberExpr>(callee);
164 const CXXMethodDecl *MD = cast<CXXMethodDecl>(ME->getMemberDecl());
166 if (MD->isStatic()) {
167 // The method is static, emit it as we would a regular call.
168 CGCallee callee = CGCallee::forDirect(CGM.GetAddrOfFunction(MD), MD);
169 return EmitCall(getContext().getPointerType(MD->getType()), callee, CE,
173 bool HasQualifier = ME->hasQualifier();
174 NestedNameSpecifier *Qualifier = HasQualifier ? ME->getQualifier() : nullptr;
175 bool IsArrow = ME->isArrow();
176 const Expr *Base = ME->getBase();
178 return EmitCXXMemberOrOperatorMemberCallExpr(
179 CE, MD, ReturnValue, HasQualifier, Qualifier, IsArrow, Base);
182 RValue CodeGenFunction::EmitCXXMemberOrOperatorMemberCallExpr(
183 const CallExpr *CE, const CXXMethodDecl *MD, ReturnValueSlot ReturnValue,
184 bool HasQualifier, NestedNameSpecifier *Qualifier, bool IsArrow,
186 assert(isa<CXXMemberCallExpr>(CE) || isa<CXXOperatorCallExpr>(CE));
188 // Compute the object pointer.
189 bool CanUseVirtualCall = MD->isVirtual() && !HasQualifier;
191 const CXXMethodDecl *DevirtualizedMethod = nullptr;
192 if (CanUseVirtualCall && CanDevirtualizeMemberFunctionCall(Base, MD)) {
193 const CXXRecordDecl *BestDynamicDecl = Base->getBestDynamicClassType();
194 DevirtualizedMethod = MD->getCorrespondingMethodInClass(BestDynamicDecl);
195 assert(DevirtualizedMethod);
196 const CXXRecordDecl *DevirtualizedClass = DevirtualizedMethod->getParent();
197 const Expr *Inner = Base->ignoreParenBaseCasts();
198 if (DevirtualizedMethod->getReturnType().getCanonicalType() !=
199 MD->getReturnType().getCanonicalType())
200 // If the return types are not the same, this might be a case where more
201 // code needs to run to compensate for it. For example, the derived
202 // method might return a type that inherits form from the return
203 // type of MD and has a prefix.
204 // For now we just avoid devirtualizing these covariant cases.
205 DevirtualizedMethod = nullptr;
206 else if (getCXXRecord(Inner) == DevirtualizedClass)
207 // If the class of the Inner expression is where the dynamic method
208 // is defined, build the this pointer from it.
210 else if (getCXXRecord(Base) != DevirtualizedClass) {
211 // If the method is defined in a class that is not the best dynamic
212 // one or the one of the full expression, we would have to build
213 // a derived-to-base cast to compute the correct this pointer, but
214 // we don't have support for that yet, so do a virtual call.
215 DevirtualizedMethod = nullptr;
219 // C++17 demands that we evaluate the RHS of a (possibly-compound) assignment
220 // operator before the LHS.
221 CallArgList RtlArgStorage;
222 CallArgList *RtlArgs = nullptr;
223 if (auto *OCE = dyn_cast<CXXOperatorCallExpr>(CE)) {
224 if (OCE->isAssignmentOp()) {
225 RtlArgs = &RtlArgStorage;
226 EmitCallArgs(*RtlArgs, MD->getType()->castAs<FunctionProtoType>(),
227 drop_begin(CE->arguments(), 1), CE->getDirectCallee(),
228 /*ParamsToSkip*/0, EvaluationOrder::ForceRightToLeft);
232 Address This = Address::invalid();
234 This = EmitPointerWithAlignment(Base);
236 This = EmitLValue(Base).getAddress();
239 if (MD->isTrivial() || (MD->isDefaulted() && MD->getParent()->isUnion())) {
240 if (isa<CXXDestructorDecl>(MD)) return RValue::get(nullptr);
241 if (isa<CXXConstructorDecl>(MD) &&
242 cast<CXXConstructorDecl>(MD)->isDefaultConstructor())
243 return RValue::get(nullptr);
245 if (!MD->getParent()->mayInsertExtraPadding()) {
246 if (MD->isCopyAssignmentOperator() || MD->isMoveAssignmentOperator()) {
247 // We don't like to generate the trivial copy/move assignment operator
248 // when it isn't necessary; just produce the proper effect here.
249 LValue RHS = isa<CXXOperatorCallExpr>(CE)
250 ? MakeNaturalAlignAddrLValue(
251 (*RtlArgs)[0].RV.getScalarVal(),
252 (*(CE->arg_begin() + 1))->getType())
253 : EmitLValue(*CE->arg_begin());
254 EmitAggregateAssign(This, RHS.getAddress(), CE->getType());
255 return RValue::get(This.getPointer());
258 if (isa<CXXConstructorDecl>(MD) &&
259 cast<CXXConstructorDecl>(MD)->isCopyOrMoveConstructor()) {
260 // Trivial move and copy ctor are the same.
261 assert(CE->getNumArgs() == 1 && "unexpected argcount for trivial ctor");
262 Address RHS = EmitLValue(*CE->arg_begin()).getAddress();
263 EmitAggregateCopy(This, RHS, (*CE->arg_begin())->getType());
264 return RValue::get(This.getPointer());
266 llvm_unreachable("unknown trivial member function");
270 // Compute the function type we're calling.
271 const CXXMethodDecl *CalleeDecl =
272 DevirtualizedMethod ? DevirtualizedMethod : MD;
273 const CGFunctionInfo *FInfo = nullptr;
274 if (const auto *Dtor = dyn_cast<CXXDestructorDecl>(CalleeDecl))
275 FInfo = &CGM.getTypes().arrangeCXXStructorDeclaration(
276 Dtor, StructorType::Complete);
277 else if (const auto *Ctor = dyn_cast<CXXConstructorDecl>(CalleeDecl))
278 FInfo = &CGM.getTypes().arrangeCXXStructorDeclaration(
279 Ctor, StructorType::Complete);
281 FInfo = &CGM.getTypes().arrangeCXXMethodDeclaration(CalleeDecl);
283 llvm::FunctionType *Ty = CGM.getTypes().GetFunctionType(*FInfo);
285 // C++11 [class.mfct.non-static]p2:
286 // If a non-static member function of a class X is called for an object that
287 // is not of type X, or of a type derived from X, the behavior is undefined.
288 SourceLocation CallLoc;
289 ASTContext &C = getContext();
291 CallLoc = CE->getExprLoc();
293 EmitTypeCheck(isa<CXXConstructorDecl>(CalleeDecl)
294 ? CodeGenFunction::TCK_ConstructorCall
295 : CodeGenFunction::TCK_MemberCall,
296 CallLoc, This.getPointer(), C.getRecordType(CalleeDecl->getParent()));
298 // FIXME: Uses of 'MD' past this point need to be audited. We may need to use
299 // 'CalleeDecl' instead.
301 // C++ [class.virtual]p12:
302 // Explicit qualification with the scope operator (5.1) suppresses the
303 // virtual call mechanism.
305 // We also don't emit a virtual call if the base expression has a record type
306 // because then we know what the type is.
307 bool UseVirtualCall = CanUseVirtualCall && !DevirtualizedMethod;
309 if (const CXXDestructorDecl *Dtor = dyn_cast<CXXDestructorDecl>(MD)) {
310 assert(CE->arg_begin() == CE->arg_end() &&
311 "Destructor shouldn't have explicit parameters");
312 assert(ReturnValue.isNull() && "Destructor shouldn't have return value");
313 if (UseVirtualCall) {
314 CGM.getCXXABI().EmitVirtualDestructorCall(
315 *this, Dtor, Dtor_Complete, This, cast<CXXMemberCallExpr>(CE));
318 if (getLangOpts().AppleKext && MD->isVirtual() && HasQualifier)
319 Callee = BuildAppleKextVirtualCall(MD, Qualifier, Ty);
320 else if (!DevirtualizedMethod)
321 Callee = CGCallee::forDirect(
322 CGM.getAddrOfCXXStructor(Dtor, StructorType::Complete, FInfo, Ty),
325 const CXXDestructorDecl *DDtor =
326 cast<CXXDestructorDecl>(DevirtualizedMethod);
327 Callee = CGCallee::forDirect(
328 CGM.GetAddrOfFunction(GlobalDecl(DDtor, Dtor_Complete), Ty),
331 EmitCXXMemberOrOperatorCall(
332 CalleeDecl, Callee, ReturnValue, This.getPointer(),
333 /*ImplicitParam=*/nullptr, QualType(), CE, nullptr);
335 return RValue::get(nullptr);
339 if (const CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(MD)) {
340 Callee = CGCallee::forDirect(
341 CGM.GetAddrOfFunction(GlobalDecl(Ctor, Ctor_Complete), Ty),
343 } else if (UseVirtualCall) {
344 Callee = CGM.getCXXABI().getVirtualFunctionPointer(*this, MD, This, Ty,
347 if (SanOpts.has(SanitizerKind::CFINVCall) &&
348 MD->getParent()->isDynamicClass()) {
349 llvm::Value *VTable = GetVTablePtr(This, Int8PtrTy, MD->getParent());
350 EmitVTablePtrCheckForCall(MD->getParent(), VTable, CFITCK_NVCall,
354 if (getLangOpts().AppleKext && MD->isVirtual() && HasQualifier)
355 Callee = BuildAppleKextVirtualCall(MD, Qualifier, Ty);
356 else if (!DevirtualizedMethod)
357 Callee = CGCallee::forDirect(CGM.GetAddrOfFunction(MD, Ty), MD);
359 Callee = CGCallee::forDirect(
360 CGM.GetAddrOfFunction(DevirtualizedMethod, Ty),
361 DevirtualizedMethod);
365 if (MD->isVirtual()) {
366 This = CGM.getCXXABI().adjustThisArgumentForVirtualFunctionCall(
367 *this, CalleeDecl, This, UseVirtualCall);
370 return EmitCXXMemberOrOperatorCall(
371 CalleeDecl, Callee, ReturnValue, This.getPointer(),
372 /*ImplicitParam=*/nullptr, QualType(), CE, RtlArgs);
376 CodeGenFunction::EmitCXXMemberPointerCallExpr(const CXXMemberCallExpr *E,
377 ReturnValueSlot ReturnValue) {
378 const BinaryOperator *BO =
379 cast<BinaryOperator>(E->getCallee()->IgnoreParens());
380 const Expr *BaseExpr = BO->getLHS();
381 const Expr *MemFnExpr = BO->getRHS();
383 const MemberPointerType *MPT =
384 MemFnExpr->getType()->castAs<MemberPointerType>();
386 const FunctionProtoType *FPT =
387 MPT->getPointeeType()->castAs<FunctionProtoType>();
388 const CXXRecordDecl *RD =
389 cast<CXXRecordDecl>(MPT->getClass()->getAs<RecordType>()->getDecl());
391 // Emit the 'this' pointer.
392 Address This = Address::invalid();
393 if (BO->getOpcode() == BO_PtrMemI)
394 This = EmitPointerWithAlignment(BaseExpr);
396 This = EmitLValue(BaseExpr).getAddress();
398 EmitTypeCheck(TCK_MemberCall, E->getExprLoc(), This.getPointer(),
399 QualType(MPT->getClass(), 0));
401 // Get the member function pointer.
402 llvm::Value *MemFnPtr = EmitScalarExpr(MemFnExpr);
404 // Ask the ABI to load the callee. Note that This is modified.
405 llvm::Value *ThisPtrForCall = nullptr;
407 CGM.getCXXABI().EmitLoadOfMemberFunctionPointer(*this, BO, This,
408 ThisPtrForCall, MemFnPtr, MPT);
413 getContext().getPointerType(getContext().getTagDeclType(RD));
415 // Push the this ptr.
416 Args.add(RValue::get(ThisPtrForCall), ThisType);
418 RequiredArgs required =
419 RequiredArgs::forPrototypePlus(FPT, 1, /*FD=*/nullptr);
421 // And the rest of the call args
422 EmitCallArgs(Args, FPT, E->arguments());
423 return EmitCall(CGM.getTypes().arrangeCXXMethodCall(Args, FPT, required),
424 Callee, ReturnValue, Args);
428 CodeGenFunction::EmitCXXOperatorMemberCallExpr(const CXXOperatorCallExpr *E,
429 const CXXMethodDecl *MD,
430 ReturnValueSlot ReturnValue) {
431 assert(MD->isInstance() &&
432 "Trying to emit a member call expr on a static method!");
433 return EmitCXXMemberOrOperatorMemberCallExpr(
434 E, MD, ReturnValue, /*HasQualifier=*/false, /*Qualifier=*/nullptr,
435 /*IsArrow=*/false, E->getArg(0));
438 RValue CodeGenFunction::EmitCUDAKernelCallExpr(const CUDAKernelCallExpr *E,
439 ReturnValueSlot ReturnValue) {
440 return CGM.getCUDARuntime().EmitCUDAKernelCallExpr(*this, E, ReturnValue);
443 static void EmitNullBaseClassInitialization(CodeGenFunction &CGF,
445 const CXXRecordDecl *Base) {
449 DestPtr = CGF.Builder.CreateElementBitCast(DestPtr, CGF.Int8Ty);
451 const ASTRecordLayout &Layout = CGF.getContext().getASTRecordLayout(Base);
452 CharUnits NVSize = Layout.getNonVirtualSize();
454 // We cannot simply zero-initialize the entire base sub-object if vbptrs are
455 // present, they are initialized by the most derived class before calling the
457 SmallVector<std::pair<CharUnits, CharUnits>, 1> Stores;
458 Stores.emplace_back(CharUnits::Zero(), NVSize);
460 // Each store is split by the existence of a vbptr.
461 CharUnits VBPtrWidth = CGF.getPointerSize();
462 std::vector<CharUnits> VBPtrOffsets =
463 CGF.CGM.getCXXABI().getVBPtrOffsets(Base);
464 for (CharUnits VBPtrOffset : VBPtrOffsets) {
465 // Stop before we hit any virtual base pointers located in virtual bases.
466 if (VBPtrOffset >= NVSize)
468 std::pair<CharUnits, CharUnits> LastStore = Stores.pop_back_val();
469 CharUnits LastStoreOffset = LastStore.first;
470 CharUnits LastStoreSize = LastStore.second;
472 CharUnits SplitBeforeOffset = LastStoreOffset;
473 CharUnits SplitBeforeSize = VBPtrOffset - SplitBeforeOffset;
474 assert(!SplitBeforeSize.isNegative() && "negative store size!");
475 if (!SplitBeforeSize.isZero())
476 Stores.emplace_back(SplitBeforeOffset, SplitBeforeSize);
478 CharUnits SplitAfterOffset = VBPtrOffset + VBPtrWidth;
479 CharUnits SplitAfterSize = LastStoreSize - SplitAfterOffset;
480 assert(!SplitAfterSize.isNegative() && "negative store size!");
481 if (!SplitAfterSize.isZero())
482 Stores.emplace_back(SplitAfterOffset, SplitAfterSize);
485 // If the type contains a pointer to data member we can't memset it to zero.
486 // Instead, create a null constant and copy it to the destination.
487 // TODO: there are other patterns besides zero that we can usefully memset,
488 // like -1, which happens to be the pattern used by member-pointers.
489 // TODO: isZeroInitializable can be over-conservative in the case where a
490 // virtual base contains a member pointer.
491 llvm::Constant *NullConstantForBase = CGF.CGM.EmitNullConstantForBase(Base);
492 if (!NullConstantForBase->isNullValue()) {
493 llvm::GlobalVariable *NullVariable = new llvm::GlobalVariable(
494 CGF.CGM.getModule(), NullConstantForBase->getType(),
495 /*isConstant=*/true, llvm::GlobalVariable::PrivateLinkage,
496 NullConstantForBase, Twine());
498 CharUnits Align = std::max(Layout.getNonVirtualAlignment(),
499 DestPtr.getAlignment());
500 NullVariable->setAlignment(Align.getQuantity());
502 Address SrcPtr = Address(CGF.EmitCastToVoidPtr(NullVariable), Align);
504 // Get and call the appropriate llvm.memcpy overload.
505 for (std::pair<CharUnits, CharUnits> Store : Stores) {
506 CharUnits StoreOffset = Store.first;
507 CharUnits StoreSize = Store.second;
508 llvm::Value *StoreSizeVal = CGF.CGM.getSize(StoreSize);
509 CGF.Builder.CreateMemCpy(
510 CGF.Builder.CreateConstInBoundsByteGEP(DestPtr, StoreOffset),
511 CGF.Builder.CreateConstInBoundsByteGEP(SrcPtr, StoreOffset),
515 // Otherwise, just memset the whole thing to zero. This is legal
516 // because in LLVM, all default initializers (other than the ones we just
517 // handled above) are guaranteed to have a bit pattern of all zeros.
519 for (std::pair<CharUnits, CharUnits> Store : Stores) {
520 CharUnits StoreOffset = Store.first;
521 CharUnits StoreSize = Store.second;
522 llvm::Value *StoreSizeVal = CGF.CGM.getSize(StoreSize);
523 CGF.Builder.CreateMemSet(
524 CGF.Builder.CreateConstInBoundsByteGEP(DestPtr, StoreOffset),
525 CGF.Builder.getInt8(0), StoreSizeVal);
531 CodeGenFunction::EmitCXXConstructExpr(const CXXConstructExpr *E,
533 assert(!Dest.isIgnored() && "Must have a destination!");
534 const CXXConstructorDecl *CD = E->getConstructor();
536 // If we require zero initialization before (or instead of) calling the
537 // constructor, as can be the case with a non-user-provided default
538 // constructor, emit the zero initialization now, unless destination is
540 if (E->requiresZeroInitialization() && !Dest.isZeroed()) {
541 switch (E->getConstructionKind()) {
542 case CXXConstructExpr::CK_Delegating:
543 case CXXConstructExpr::CK_Complete:
544 EmitNullInitialization(Dest.getAddress(), E->getType());
546 case CXXConstructExpr::CK_VirtualBase:
547 case CXXConstructExpr::CK_NonVirtualBase:
548 EmitNullBaseClassInitialization(*this, Dest.getAddress(),
554 // If this is a call to a trivial default constructor, do nothing.
555 if (CD->isTrivial() && CD->isDefaultConstructor())
558 // Elide the constructor if we're constructing from a temporary.
559 // The temporary check is required because Sema sets this on NRVO
561 if (getLangOpts().ElideConstructors && E->isElidable()) {
562 assert(getContext().hasSameUnqualifiedType(E->getType(),
563 E->getArg(0)->getType()));
564 if (E->getArg(0)->isTemporaryObject(getContext(), CD->getParent())) {
565 EmitAggExpr(E->getArg(0), Dest);
570 if (const ArrayType *arrayType
571 = getContext().getAsArrayType(E->getType())) {
572 EmitCXXAggrConstructorCall(CD, arrayType, Dest.getAddress(), E);
574 CXXCtorType Type = Ctor_Complete;
575 bool ForVirtualBase = false;
576 bool Delegating = false;
578 switch (E->getConstructionKind()) {
579 case CXXConstructExpr::CK_Delegating:
580 // We should be emitting a constructor; GlobalDecl will assert this
581 Type = CurGD.getCtorType();
585 case CXXConstructExpr::CK_Complete:
586 Type = Ctor_Complete;
589 case CXXConstructExpr::CK_VirtualBase:
590 ForVirtualBase = true;
593 case CXXConstructExpr::CK_NonVirtualBase:
597 // Call the constructor.
598 EmitCXXConstructorCall(CD, Type, ForVirtualBase, Delegating,
599 Dest.getAddress(), E);
603 void CodeGenFunction::EmitSynthesizedCXXCopyCtor(Address Dest, Address Src,
605 if (const ExprWithCleanups *E = dyn_cast<ExprWithCleanups>(Exp))
606 Exp = E->getSubExpr();
607 assert(isa<CXXConstructExpr>(Exp) &&
608 "EmitSynthesizedCXXCopyCtor - unknown copy ctor expr");
609 const CXXConstructExpr* E = cast<CXXConstructExpr>(Exp);
610 const CXXConstructorDecl *CD = E->getConstructor();
611 RunCleanupsScope Scope(*this);
613 // If we require zero initialization before (or instead of) calling the
614 // constructor, as can be the case with a non-user-provided default
615 // constructor, emit the zero initialization now.
616 // FIXME. Do I still need this for a copy ctor synthesis?
617 if (E->requiresZeroInitialization())
618 EmitNullInitialization(Dest, E->getType());
620 assert(!getContext().getAsConstantArrayType(E->getType())
621 && "EmitSynthesizedCXXCopyCtor - Copied-in Array");
622 EmitSynthesizedCXXCopyCtorCall(CD, Dest, Src, E);
625 static CharUnits CalculateCookiePadding(CodeGenFunction &CGF,
626 const CXXNewExpr *E) {
628 return CharUnits::Zero();
630 // No cookie is required if the operator new[] being used is the
631 // reserved placement operator new[].
632 if (E->getOperatorNew()->isReservedGlobalPlacementOperator())
633 return CharUnits::Zero();
635 return CGF.CGM.getCXXABI().GetArrayCookieSize(E);
638 static llvm::Value *EmitCXXNewAllocSize(CodeGenFunction &CGF,
640 unsigned minElements,
641 llvm::Value *&numElements,
642 llvm::Value *&sizeWithoutCookie) {
643 QualType type = e->getAllocatedType();
646 CharUnits typeSize = CGF.getContext().getTypeSizeInChars(type);
648 = llvm::ConstantInt::get(CGF.SizeTy, typeSize.getQuantity());
649 return sizeWithoutCookie;
652 // The width of size_t.
653 unsigned sizeWidth = CGF.SizeTy->getBitWidth();
655 // Figure out the cookie size.
656 llvm::APInt cookieSize(sizeWidth,
657 CalculateCookiePadding(CGF, e).getQuantity());
659 // Emit the array size expression.
660 // We multiply the size of all dimensions for NumElements.
661 // e.g for 'int[2][3]', ElemType is 'int' and NumElements is 6.
662 numElements = CGF.EmitScalarExpr(e->getArraySize());
663 assert(isa<llvm::IntegerType>(numElements->getType()));
665 // The number of elements can be have an arbitrary integer type;
666 // essentially, we need to multiply it by a constant factor, add a
667 // cookie size, and verify that the result is representable as a
668 // size_t. That's just a gloss, though, and it's wrong in one
669 // important way: if the count is negative, it's an error even if
670 // the cookie size would bring the total size >= 0.
672 = e->getArraySize()->getType()->isSignedIntegerOrEnumerationType();
673 llvm::IntegerType *numElementsType
674 = cast<llvm::IntegerType>(numElements->getType());
675 unsigned numElementsWidth = numElementsType->getBitWidth();
677 // Compute the constant factor.
678 llvm::APInt arraySizeMultiplier(sizeWidth, 1);
679 while (const ConstantArrayType *CAT
680 = CGF.getContext().getAsConstantArrayType(type)) {
681 type = CAT->getElementType();
682 arraySizeMultiplier *= CAT->getSize();
685 CharUnits typeSize = CGF.getContext().getTypeSizeInChars(type);
686 llvm::APInt typeSizeMultiplier(sizeWidth, typeSize.getQuantity());
687 typeSizeMultiplier *= arraySizeMultiplier;
689 // This will be a size_t.
692 // If someone is doing 'new int[42]' there is no need to do a dynamic check.
693 // Don't bloat the -O0 code.
694 if (llvm::ConstantInt *numElementsC =
695 dyn_cast<llvm::ConstantInt>(numElements)) {
696 const llvm::APInt &count = numElementsC->getValue();
698 bool hasAnyOverflow = false;
700 // If 'count' was a negative number, it's an overflow.
701 if (isSigned && count.isNegative())
702 hasAnyOverflow = true;
704 // We want to do all this arithmetic in size_t. If numElements is
705 // wider than that, check whether it's already too big, and if so,
707 else if (numElementsWidth > sizeWidth &&
708 numElementsWidth - sizeWidth > count.countLeadingZeros())
709 hasAnyOverflow = true;
711 // Okay, compute a count at the right width.
712 llvm::APInt adjustedCount = count.zextOrTrunc(sizeWidth);
714 // If there is a brace-initializer, we cannot allocate fewer elements than
715 // there are initializers. If we do, that's treated like an overflow.
716 if (adjustedCount.ult(minElements))
717 hasAnyOverflow = true;
719 // Scale numElements by that. This might overflow, but we don't
720 // care because it only overflows if allocationSize does, too, and
721 // if that overflows then we shouldn't use this.
722 numElements = llvm::ConstantInt::get(CGF.SizeTy,
723 adjustedCount * arraySizeMultiplier);
725 // Compute the size before cookie, and track whether it overflowed.
727 llvm::APInt allocationSize
728 = adjustedCount.umul_ov(typeSizeMultiplier, overflow);
729 hasAnyOverflow |= overflow;
731 // Add in the cookie, and check whether it's overflowed.
732 if (cookieSize != 0) {
733 // Save the current size without a cookie. This shouldn't be
734 // used if there was overflow.
735 sizeWithoutCookie = llvm::ConstantInt::get(CGF.SizeTy, allocationSize);
737 allocationSize = allocationSize.uadd_ov(cookieSize, overflow);
738 hasAnyOverflow |= overflow;
741 // On overflow, produce a -1 so operator new will fail.
742 if (hasAnyOverflow) {
743 size = llvm::Constant::getAllOnesValue(CGF.SizeTy);
745 size = llvm::ConstantInt::get(CGF.SizeTy, allocationSize);
748 // Otherwise, we might need to use the overflow intrinsics.
750 // There are up to five conditions we need to test for:
751 // 1) if isSigned, we need to check whether numElements is negative;
752 // 2) if numElementsWidth > sizeWidth, we need to check whether
753 // numElements is larger than something representable in size_t;
754 // 3) if minElements > 0, we need to check whether numElements is smaller
756 // 4) we need to compute
757 // sizeWithoutCookie := numElements * typeSizeMultiplier
758 // and check whether it overflows; and
759 // 5) if we need a cookie, we need to compute
760 // size := sizeWithoutCookie + cookieSize
761 // and check whether it overflows.
763 llvm::Value *hasOverflow = nullptr;
765 // If numElementsWidth > sizeWidth, then one way or another, we're
766 // going to have to do a comparison for (2), and this happens to
767 // take care of (1), too.
768 if (numElementsWidth > sizeWidth) {
769 llvm::APInt threshold(numElementsWidth, 1);
770 threshold <<= sizeWidth;
772 llvm::Value *thresholdV
773 = llvm::ConstantInt::get(numElementsType, threshold);
775 hasOverflow = CGF.Builder.CreateICmpUGE(numElements, thresholdV);
776 numElements = CGF.Builder.CreateTrunc(numElements, CGF.SizeTy);
778 // Otherwise, if we're signed, we want to sext up to size_t.
779 } else if (isSigned) {
780 if (numElementsWidth < sizeWidth)
781 numElements = CGF.Builder.CreateSExt(numElements, CGF.SizeTy);
783 // If there's a non-1 type size multiplier, then we can do the
784 // signedness check at the same time as we do the multiply
785 // because a negative number times anything will cause an
786 // unsigned overflow. Otherwise, we have to do it here. But at least
787 // in this case, we can subsume the >= minElements check.
788 if (typeSizeMultiplier == 1)
789 hasOverflow = CGF.Builder.CreateICmpSLT(numElements,
790 llvm::ConstantInt::get(CGF.SizeTy, minElements));
792 // Otherwise, zext up to size_t if necessary.
793 } else if (numElementsWidth < sizeWidth) {
794 numElements = CGF.Builder.CreateZExt(numElements, CGF.SizeTy);
797 assert(numElements->getType() == CGF.SizeTy);
800 // Don't allow allocation of fewer elements than we have initializers.
802 hasOverflow = CGF.Builder.CreateICmpULT(numElements,
803 llvm::ConstantInt::get(CGF.SizeTy, minElements));
804 } else if (numElementsWidth > sizeWidth) {
805 // The other existing overflow subsumes this check.
806 // We do an unsigned comparison, since any signed value < -1 is
807 // taken care of either above or below.
808 hasOverflow = CGF.Builder.CreateOr(hasOverflow,
809 CGF.Builder.CreateICmpULT(numElements,
810 llvm::ConstantInt::get(CGF.SizeTy, minElements)));
816 // Multiply by the type size if necessary. This multiplier
817 // includes all the factors for nested arrays.
819 // This step also causes numElements to be scaled up by the
820 // nested-array factor if necessary. Overflow on this computation
821 // can be ignored because the result shouldn't be used if
823 if (typeSizeMultiplier != 1) {
824 llvm::Value *umul_with_overflow
825 = CGF.CGM.getIntrinsic(llvm::Intrinsic::umul_with_overflow, CGF.SizeTy);
828 llvm::ConstantInt::get(CGF.SizeTy, typeSizeMultiplier);
829 llvm::Value *result =
830 CGF.Builder.CreateCall(umul_with_overflow, {size, tsmV});
832 llvm::Value *overflowed = CGF.Builder.CreateExtractValue(result, 1);
834 hasOverflow = CGF.Builder.CreateOr(hasOverflow, overflowed);
836 hasOverflow = overflowed;
838 size = CGF.Builder.CreateExtractValue(result, 0);
840 // Also scale up numElements by the array size multiplier.
841 if (arraySizeMultiplier != 1) {
842 // If the base element type size is 1, then we can re-use the
843 // multiply we just did.
844 if (typeSize.isOne()) {
845 assert(arraySizeMultiplier == typeSizeMultiplier);
848 // Otherwise we need a separate multiply.
851 llvm::ConstantInt::get(CGF.SizeTy, arraySizeMultiplier);
852 numElements = CGF.Builder.CreateMul(numElements, asmV);
856 // numElements doesn't need to be scaled.
857 assert(arraySizeMultiplier == 1);
860 // Add in the cookie size if necessary.
861 if (cookieSize != 0) {
862 sizeWithoutCookie = size;
864 llvm::Value *uadd_with_overflow
865 = CGF.CGM.getIntrinsic(llvm::Intrinsic::uadd_with_overflow, CGF.SizeTy);
867 llvm::Value *cookieSizeV = llvm::ConstantInt::get(CGF.SizeTy, cookieSize);
868 llvm::Value *result =
869 CGF.Builder.CreateCall(uadd_with_overflow, {size, cookieSizeV});
871 llvm::Value *overflowed = CGF.Builder.CreateExtractValue(result, 1);
873 hasOverflow = CGF.Builder.CreateOr(hasOverflow, overflowed);
875 hasOverflow = overflowed;
877 size = CGF.Builder.CreateExtractValue(result, 0);
880 // If we had any possibility of dynamic overflow, make a select to
881 // overwrite 'size' with an all-ones value, which should cause
882 // operator new to throw.
884 size = CGF.Builder.CreateSelect(hasOverflow,
885 llvm::Constant::getAllOnesValue(CGF.SizeTy),
890 sizeWithoutCookie = size;
892 assert(sizeWithoutCookie && "didn't set sizeWithoutCookie?");
897 static void StoreAnyExprIntoOneUnit(CodeGenFunction &CGF, const Expr *Init,
898 QualType AllocType, Address NewPtr) {
899 // FIXME: Refactor with EmitExprAsInit.
900 switch (CGF.getEvaluationKind(AllocType)) {
902 CGF.EmitScalarInit(Init, nullptr,
903 CGF.MakeAddrLValue(NewPtr, AllocType), false);
906 CGF.EmitComplexExprIntoLValue(Init, CGF.MakeAddrLValue(NewPtr, AllocType),
909 case TEK_Aggregate: {
911 = AggValueSlot::forAddr(NewPtr, AllocType.getQualifiers(),
912 AggValueSlot::IsDestructed,
913 AggValueSlot::DoesNotNeedGCBarriers,
914 AggValueSlot::IsNotAliased);
915 CGF.EmitAggExpr(Init, Slot);
919 llvm_unreachable("bad evaluation kind");
922 void CodeGenFunction::EmitNewArrayInitializer(
923 const CXXNewExpr *E, QualType ElementType, llvm::Type *ElementTy,
924 Address BeginPtr, llvm::Value *NumElements,
925 llvm::Value *AllocSizeWithoutCookie) {
926 // If we have a type with trivial initialization and no initializer,
927 // there's nothing to do.
928 if (!E->hasInitializer())
931 Address CurPtr = BeginPtr;
933 unsigned InitListElements = 0;
935 const Expr *Init = E->getInitializer();
936 Address EndOfInit = Address::invalid();
937 QualType::DestructionKind DtorKind = ElementType.isDestructedType();
938 EHScopeStack::stable_iterator Cleanup;
939 llvm::Instruction *CleanupDominator = nullptr;
941 CharUnits ElementSize = getContext().getTypeSizeInChars(ElementType);
942 CharUnits ElementAlign =
943 BeginPtr.getAlignment().alignmentOfArrayElement(ElementSize);
945 // Attempt to perform zero-initialization using memset.
946 auto TryMemsetInitialization = [&]() -> bool {
947 // FIXME: If the type is a pointer-to-data-member under the Itanium ABI,
948 // we can initialize with a memset to -1.
949 if (!CGM.getTypes().isZeroInitializable(ElementType))
952 // Optimization: since zero initialization will just set the memory
953 // to all zeroes, generate a single memset to do it in one shot.
955 // Subtract out the size of any elements we've already initialized.
956 auto *RemainingSize = AllocSizeWithoutCookie;
957 if (InitListElements) {
958 // We know this can't overflow; we check this when doing the allocation.
959 auto *InitializedSize = llvm::ConstantInt::get(
960 RemainingSize->getType(),
961 getContext().getTypeSizeInChars(ElementType).getQuantity() *
963 RemainingSize = Builder.CreateSub(RemainingSize, InitializedSize);
966 // Create the memset.
967 Builder.CreateMemSet(CurPtr, Builder.getInt8(0), RemainingSize, false);
971 // If the initializer is an initializer list, first do the explicit elements.
972 if (const InitListExpr *ILE = dyn_cast<InitListExpr>(Init)) {
973 // Initializing from a (braced) string literal is a special case; the init
974 // list element does not initialize a (single) array element.
975 if (ILE->isStringLiteralInit()) {
976 // Initialize the initial portion of length equal to that of the string
977 // literal. The allocation must be for at least this much; we emitted a
978 // check for that earlier.
980 AggValueSlot::forAddr(CurPtr, ElementType.getQualifiers(),
981 AggValueSlot::IsDestructed,
982 AggValueSlot::DoesNotNeedGCBarriers,
983 AggValueSlot::IsNotAliased);
984 EmitAggExpr(ILE->getInit(0), Slot);
986 // Move past these elements.
988 cast<ConstantArrayType>(ILE->getType()->getAsArrayTypeUnsafe())
989 ->getSize().getZExtValue();
991 Address(Builder.CreateInBoundsGEP(CurPtr.getPointer(),
992 Builder.getSize(InitListElements),
994 CurPtr.getAlignment().alignmentAtOffset(InitListElements *
997 // Zero out the rest, if any remain.
998 llvm::ConstantInt *ConstNum = dyn_cast<llvm::ConstantInt>(NumElements);
999 if (!ConstNum || !ConstNum->equalsInt(InitListElements)) {
1000 bool OK = TryMemsetInitialization();
1002 assert(OK && "couldn't memset character type?");
1007 InitListElements = ILE->getNumInits();
1009 // If this is a multi-dimensional array new, we will initialize multiple
1010 // elements with each init list element.
1011 QualType AllocType = E->getAllocatedType();
1012 if (const ConstantArrayType *CAT = dyn_cast_or_null<ConstantArrayType>(
1013 AllocType->getAsArrayTypeUnsafe())) {
1014 ElementTy = ConvertTypeForMem(AllocType);
1015 CurPtr = Builder.CreateElementBitCast(CurPtr, ElementTy);
1016 InitListElements *= getContext().getConstantArrayElementCount(CAT);
1019 // Enter a partial-destruction Cleanup if necessary.
1020 if (needsEHCleanup(DtorKind)) {
1021 // In principle we could tell the Cleanup where we are more
1022 // directly, but the control flow can get so varied here that it
1023 // would actually be quite complex. Therefore we go through an
1025 EndOfInit = CreateTempAlloca(BeginPtr.getType(), getPointerAlign(),
1027 CleanupDominator = Builder.CreateStore(BeginPtr.getPointer(), EndOfInit);
1028 pushIrregularPartialArrayCleanup(BeginPtr.getPointer(), EndOfInit,
1029 ElementType, ElementAlign,
1030 getDestroyer(DtorKind));
1031 Cleanup = EHStack.stable_begin();
1034 CharUnits StartAlign = CurPtr.getAlignment();
1035 for (unsigned i = 0, e = ILE->getNumInits(); i != e; ++i) {
1036 // Tell the cleanup that it needs to destroy up to this
1037 // element. TODO: some of these stores can be trivially
1038 // observed to be unnecessary.
1039 if (EndOfInit.isValid()) {
1041 Builder.CreateBitCast(CurPtr.getPointer(), BeginPtr.getType());
1042 Builder.CreateStore(FinishedPtr, EndOfInit);
1044 // FIXME: If the last initializer is an incomplete initializer list for
1045 // an array, and we have an array filler, we can fold together the two
1046 // initialization loops.
1047 StoreAnyExprIntoOneUnit(*this, ILE->getInit(i),
1048 ILE->getInit(i)->getType(), CurPtr);
1049 CurPtr = Address(Builder.CreateInBoundsGEP(CurPtr.getPointer(),
1052 StartAlign.alignmentAtOffset((i + 1) * ElementSize));
1055 // The remaining elements are filled with the array filler expression.
1056 Init = ILE->getArrayFiller();
1058 // Extract the initializer for the individual array elements by pulling
1059 // out the array filler from all the nested initializer lists. This avoids
1060 // generating a nested loop for the initialization.
1061 while (Init && Init->getType()->isConstantArrayType()) {
1062 auto *SubILE = dyn_cast<InitListExpr>(Init);
1065 assert(SubILE->getNumInits() == 0 && "explicit inits in array filler?");
1066 Init = SubILE->getArrayFiller();
1069 // Switch back to initializing one base element at a time.
1070 CurPtr = Builder.CreateBitCast(CurPtr, BeginPtr.getType());
1073 // If all elements have already been initialized, skip any further
1075 llvm::ConstantInt *ConstNum = dyn_cast<llvm::ConstantInt>(NumElements);
1076 if (ConstNum && ConstNum->getZExtValue() <= InitListElements) {
1077 // If there was a Cleanup, deactivate it.
1078 if (CleanupDominator)
1079 DeactivateCleanupBlock(Cleanup, CleanupDominator);
1083 assert(Init && "have trailing elements to initialize but no initializer");
1085 // If this is a constructor call, try to optimize it out, and failing that
1086 // emit a single loop to initialize all remaining elements.
1087 if (const CXXConstructExpr *CCE = dyn_cast<CXXConstructExpr>(Init)) {
1088 CXXConstructorDecl *Ctor = CCE->getConstructor();
1089 if (Ctor->isTrivial()) {
1090 // If new expression did not specify value-initialization, then there
1091 // is no initialization.
1092 if (!CCE->requiresZeroInitialization() || Ctor->getParent()->isEmpty())
1095 if (TryMemsetInitialization())
1099 // Store the new Cleanup position for irregular Cleanups.
1101 // FIXME: Share this cleanup with the constructor call emission rather than
1102 // having it create a cleanup of its own.
1103 if (EndOfInit.isValid())
1104 Builder.CreateStore(CurPtr.getPointer(), EndOfInit);
1106 // Emit a constructor call loop to initialize the remaining elements.
1107 if (InitListElements)
1108 NumElements = Builder.CreateSub(
1110 llvm::ConstantInt::get(NumElements->getType(), InitListElements));
1111 EmitCXXAggrConstructorCall(Ctor, NumElements, CurPtr, CCE,
1112 CCE->requiresZeroInitialization());
1116 // If this is value-initialization, we can usually use memset.
1117 ImplicitValueInitExpr IVIE(ElementType);
1118 if (isa<ImplicitValueInitExpr>(Init)) {
1119 if (TryMemsetInitialization())
1122 // Switch to an ImplicitValueInitExpr for the element type. This handles
1123 // only one case: multidimensional array new of pointers to members. In
1124 // all other cases, we already have an initializer for the array element.
1128 // At this point we should have found an initializer for the individual
1129 // elements of the array.
1130 assert(getContext().hasSameUnqualifiedType(ElementType, Init->getType()) &&
1131 "got wrong type of element to initialize");
1133 // If we have an empty initializer list, we can usually use memset.
1134 if (auto *ILE = dyn_cast<InitListExpr>(Init))
1135 if (ILE->getNumInits() == 0 && TryMemsetInitialization())
1138 // If we have a struct whose every field is value-initialized, we can
1139 // usually use memset.
1140 if (auto *ILE = dyn_cast<InitListExpr>(Init)) {
1141 if (const RecordType *RType = ILE->getType()->getAs<RecordType>()) {
1142 if (RType->getDecl()->isStruct()) {
1143 unsigned NumElements = 0;
1144 if (auto *CXXRD = dyn_cast<CXXRecordDecl>(RType->getDecl()))
1145 NumElements = CXXRD->getNumBases();
1146 for (auto *Field : RType->getDecl()->fields())
1147 if (!Field->isUnnamedBitfield())
1149 // FIXME: Recurse into nested InitListExprs.
1150 if (ILE->getNumInits() == NumElements)
1151 for (unsigned i = 0, e = ILE->getNumInits(); i != e; ++i)
1152 if (!isa<ImplicitValueInitExpr>(ILE->getInit(i)))
1154 if (ILE->getNumInits() == NumElements && TryMemsetInitialization())
1160 // Create the loop blocks.
1161 llvm::BasicBlock *EntryBB = Builder.GetInsertBlock();
1162 llvm::BasicBlock *LoopBB = createBasicBlock("new.loop");
1163 llvm::BasicBlock *ContBB = createBasicBlock("new.loop.end");
1165 // Find the end of the array, hoisted out of the loop.
1166 llvm::Value *EndPtr =
1167 Builder.CreateInBoundsGEP(BeginPtr.getPointer(), NumElements, "array.end");
1169 // If the number of elements isn't constant, we have to now check if there is
1170 // anything left to initialize.
1172 llvm::Value *IsEmpty =
1173 Builder.CreateICmpEQ(CurPtr.getPointer(), EndPtr, "array.isempty");
1174 Builder.CreateCondBr(IsEmpty, ContBB, LoopBB);
1180 // Set up the current-element phi.
1181 llvm::PHINode *CurPtrPhi =
1182 Builder.CreatePHI(CurPtr.getType(), 2, "array.cur");
1183 CurPtrPhi->addIncoming(CurPtr.getPointer(), EntryBB);
1185 CurPtr = Address(CurPtrPhi, ElementAlign);
1187 // Store the new Cleanup position for irregular Cleanups.
1188 if (EndOfInit.isValid())
1189 Builder.CreateStore(CurPtr.getPointer(), EndOfInit);
1191 // Enter a partial-destruction Cleanup if necessary.
1192 if (!CleanupDominator && needsEHCleanup(DtorKind)) {
1193 pushRegularPartialArrayCleanup(BeginPtr.getPointer(), CurPtr.getPointer(),
1194 ElementType, ElementAlign,
1195 getDestroyer(DtorKind));
1196 Cleanup = EHStack.stable_begin();
1197 CleanupDominator = Builder.CreateUnreachable();
1200 // Emit the initializer into this element.
1201 StoreAnyExprIntoOneUnit(*this, Init, Init->getType(), CurPtr);
1203 // Leave the Cleanup if we entered one.
1204 if (CleanupDominator) {
1205 DeactivateCleanupBlock(Cleanup, CleanupDominator);
1206 CleanupDominator->eraseFromParent();
1209 // Advance to the next element by adjusting the pointer type as necessary.
1210 llvm::Value *NextPtr =
1211 Builder.CreateConstInBoundsGEP1_32(ElementTy, CurPtr.getPointer(), 1,
1214 // Check whether we've gotten to the end of the array and, if so,
1216 llvm::Value *IsEnd = Builder.CreateICmpEQ(NextPtr, EndPtr, "array.atend");
1217 Builder.CreateCondBr(IsEnd, ContBB, LoopBB);
1218 CurPtrPhi->addIncoming(NextPtr, Builder.GetInsertBlock());
1223 static void EmitNewInitializer(CodeGenFunction &CGF, const CXXNewExpr *E,
1224 QualType ElementType, llvm::Type *ElementTy,
1225 Address NewPtr, llvm::Value *NumElements,
1226 llvm::Value *AllocSizeWithoutCookie) {
1227 ApplyDebugLocation DL(CGF, E);
1229 CGF.EmitNewArrayInitializer(E, ElementType, ElementTy, NewPtr, NumElements,
1230 AllocSizeWithoutCookie);
1231 else if (const Expr *Init = E->getInitializer())
1232 StoreAnyExprIntoOneUnit(CGF, Init, E->getAllocatedType(), NewPtr);
1235 /// Emit a call to an operator new or operator delete function, as implicitly
1236 /// created by new-expressions and delete-expressions.
1237 static RValue EmitNewDeleteCall(CodeGenFunction &CGF,
1238 const FunctionDecl *CalleeDecl,
1239 const FunctionProtoType *CalleeType,
1240 const CallArgList &Args) {
1241 llvm::Instruction *CallOrInvoke;
1242 llvm::Constant *CalleePtr = CGF.CGM.GetAddrOfFunction(CalleeDecl);
1243 CGCallee Callee = CGCallee::forDirect(CalleePtr, CalleeDecl);
1245 CGF.EmitCall(CGF.CGM.getTypes().arrangeFreeFunctionCall(
1246 Args, CalleeType, /*chainCall=*/false),
1247 Callee, ReturnValueSlot(), Args, &CallOrInvoke);
1249 /// C++1y [expr.new]p10:
1250 /// [In a new-expression,] an implementation is allowed to omit a call
1251 /// to a replaceable global allocation function.
1253 /// We model such elidable calls with the 'builtin' attribute.
1254 llvm::Function *Fn = dyn_cast<llvm::Function>(CalleePtr);
1255 if (CalleeDecl->isReplaceableGlobalAllocationFunction() &&
1256 Fn && Fn->hasFnAttribute(llvm::Attribute::NoBuiltin)) {
1257 // FIXME: Add addAttribute to CallSite.
1258 if (llvm::CallInst *CI = dyn_cast<llvm::CallInst>(CallOrInvoke))
1259 CI->addAttribute(llvm::AttributeSet::FunctionIndex,
1260 llvm::Attribute::Builtin);
1261 else if (llvm::InvokeInst *II = dyn_cast<llvm::InvokeInst>(CallOrInvoke))
1262 II->addAttribute(llvm::AttributeSet::FunctionIndex,
1263 llvm::Attribute::Builtin);
1265 llvm_unreachable("unexpected kind of call instruction");
1271 RValue CodeGenFunction::EmitBuiltinNewDeleteCall(const FunctionProtoType *Type,
1275 const Stmt *ArgS = Arg;
1276 EmitCallArgs(Args, *Type->param_type_begin(), llvm::makeArrayRef(ArgS));
1277 // Find the allocation or deallocation function that we're calling.
1278 ASTContext &Ctx = getContext();
1279 DeclarationName Name = Ctx.DeclarationNames
1280 .getCXXOperatorName(IsDelete ? OO_Delete : OO_New);
1281 for (auto *Decl : Ctx.getTranslationUnitDecl()->lookup(Name))
1282 if (auto *FD = dyn_cast<FunctionDecl>(Decl))
1283 if (Ctx.hasSameType(FD->getType(), QualType(Type, 0)))
1284 return EmitNewDeleteCall(*this, cast<FunctionDecl>(Decl), Type, Args);
1285 llvm_unreachable("predeclared global operator new/delete is missing");
1288 static std::pair<bool, bool>
1289 shouldPassSizeAndAlignToUsualDelete(const FunctionProtoType *FPT) {
1290 auto AI = FPT->param_type_begin(), AE = FPT->param_type_end();
1292 // The first argument is always a void*.
1295 // Figure out what other parameters we should be implicitly passing.
1296 bool PassSize = false;
1297 bool PassAlignment = false;
1299 if (AI != AE && (*AI)->isIntegerType()) {
1304 if (AI != AE && (*AI)->isAlignValT()) {
1305 PassAlignment = true;
1309 assert(AI == AE && "unexpected usual deallocation function parameter");
1310 return {PassSize, PassAlignment};
1314 /// A cleanup to call the given 'operator delete' function upon abnormal
1315 /// exit from a new expression. Templated on a traits type that deals with
1316 /// ensuring that the arguments dominate the cleanup if necessary.
1317 template<typename Traits>
1318 class CallDeleteDuringNew final : public EHScopeStack::Cleanup {
1319 /// Type used to hold llvm::Value*s.
1320 typedef typename Traits::ValueTy ValueTy;
1321 /// Type used to hold RValues.
1322 typedef typename Traits::RValueTy RValueTy;
1323 struct PlacementArg {
1328 unsigned NumPlacementArgs : 31;
1329 unsigned PassAlignmentToPlacementDelete : 1;
1330 const FunctionDecl *OperatorDelete;
1333 CharUnits AllocAlign;
1335 PlacementArg *getPlacementArgs() {
1336 return reinterpret_cast<PlacementArg *>(this + 1);
1340 static size_t getExtraSize(size_t NumPlacementArgs) {
1341 return NumPlacementArgs * sizeof(PlacementArg);
1344 CallDeleteDuringNew(size_t NumPlacementArgs,
1345 const FunctionDecl *OperatorDelete, ValueTy Ptr,
1346 ValueTy AllocSize, bool PassAlignmentToPlacementDelete,
1347 CharUnits AllocAlign)
1348 : NumPlacementArgs(NumPlacementArgs),
1349 PassAlignmentToPlacementDelete(PassAlignmentToPlacementDelete),
1350 OperatorDelete(OperatorDelete), Ptr(Ptr), AllocSize(AllocSize),
1351 AllocAlign(AllocAlign) {}
1353 void setPlacementArg(unsigned I, RValueTy Arg, QualType Type) {
1354 assert(I < NumPlacementArgs && "index out of range");
1355 getPlacementArgs()[I] = {Arg, Type};
1358 void Emit(CodeGenFunction &CGF, Flags flags) override {
1359 const FunctionProtoType *FPT =
1360 OperatorDelete->getType()->getAs<FunctionProtoType>();
1361 CallArgList DeleteArgs;
1363 // The first argument is always a void*.
1364 DeleteArgs.add(Traits::get(CGF, Ptr), FPT->getParamType(0));
1366 // Figure out what other parameters we should be implicitly passing.
1367 bool PassSize = false;
1368 bool PassAlignment = false;
1369 if (NumPlacementArgs) {
1370 // A placement deallocation function is implicitly passed an alignment
1371 // if the placement allocation function was, but is never passed a size.
1372 PassAlignment = PassAlignmentToPlacementDelete;
1374 // For a non-placement new-expression, 'operator delete' can take a
1375 // size and/or an alignment if it has the right parameters.
1376 std::tie(PassSize, PassAlignment) =
1377 shouldPassSizeAndAlignToUsualDelete(FPT);
1380 // The second argument can be a std::size_t (for non-placement delete).
1382 DeleteArgs.add(Traits::get(CGF, AllocSize),
1383 CGF.getContext().getSizeType());
1385 // The next (second or third) argument can be a std::align_val_t, which
1386 // is an enum whose underlying type is std::size_t.
1387 // FIXME: Use the right type as the parameter type. Note that in a call
1388 // to operator delete(size_t, ...), we may not have it available.
1390 DeleteArgs.add(RValue::get(llvm::ConstantInt::get(
1391 CGF.SizeTy, AllocAlign.getQuantity())),
1392 CGF.getContext().getSizeType());
1394 // Pass the rest of the arguments, which must match exactly.
1395 for (unsigned I = 0; I != NumPlacementArgs; ++I) {
1396 auto Arg = getPlacementArgs()[I];
1397 DeleteArgs.add(Traits::get(CGF, Arg.ArgValue), Arg.ArgType);
1400 // Call 'operator delete'.
1401 EmitNewDeleteCall(CGF, OperatorDelete, FPT, DeleteArgs);
1406 /// Enter a cleanup to call 'operator delete' if the initializer in a
1407 /// new-expression throws.
1408 static void EnterNewDeleteCleanup(CodeGenFunction &CGF,
1409 const CXXNewExpr *E,
1411 llvm::Value *AllocSize,
1412 CharUnits AllocAlign,
1413 const CallArgList &NewArgs) {
1414 unsigned NumNonPlacementArgs = E->passAlignment() ? 2 : 1;
1416 // If we're not inside a conditional branch, then the cleanup will
1417 // dominate and we can do the easier (and more efficient) thing.
1418 if (!CGF.isInConditionalBranch()) {
1419 struct DirectCleanupTraits {
1420 typedef llvm::Value *ValueTy;
1421 typedef RValue RValueTy;
1422 static RValue get(CodeGenFunction &, ValueTy V) { return RValue::get(V); }
1423 static RValue get(CodeGenFunction &, RValueTy V) { return V; }
1426 typedef CallDeleteDuringNew<DirectCleanupTraits> DirectCleanup;
1428 DirectCleanup *Cleanup = CGF.EHStack
1429 .pushCleanupWithExtra<DirectCleanup>(EHCleanup,
1430 E->getNumPlacementArgs(),
1431 E->getOperatorDelete(),
1432 NewPtr.getPointer(),
1436 for (unsigned I = 0, N = E->getNumPlacementArgs(); I != N; ++I) {
1437 auto &Arg = NewArgs[I + NumNonPlacementArgs];
1438 Cleanup->setPlacementArg(I, Arg.RV, Arg.Ty);
1444 // Otherwise, we need to save all this stuff.
1445 DominatingValue<RValue>::saved_type SavedNewPtr =
1446 DominatingValue<RValue>::save(CGF, RValue::get(NewPtr.getPointer()));
1447 DominatingValue<RValue>::saved_type SavedAllocSize =
1448 DominatingValue<RValue>::save(CGF, RValue::get(AllocSize));
1450 struct ConditionalCleanupTraits {
1451 typedef DominatingValue<RValue>::saved_type ValueTy;
1452 typedef DominatingValue<RValue>::saved_type RValueTy;
1453 static RValue get(CodeGenFunction &CGF, ValueTy V) {
1454 return V.restore(CGF);
1457 typedef CallDeleteDuringNew<ConditionalCleanupTraits> ConditionalCleanup;
1459 ConditionalCleanup *Cleanup = CGF.EHStack
1460 .pushCleanupWithExtra<ConditionalCleanup>(EHCleanup,
1461 E->getNumPlacementArgs(),
1462 E->getOperatorDelete(),
1467 for (unsigned I = 0, N = E->getNumPlacementArgs(); I != N; ++I) {
1468 auto &Arg = NewArgs[I + NumNonPlacementArgs];
1469 Cleanup->setPlacementArg(I, DominatingValue<RValue>::save(CGF, Arg.RV),
1473 CGF.initFullExprCleanup();
1476 llvm::Value *CodeGenFunction::EmitCXXNewExpr(const CXXNewExpr *E) {
1477 // The element type being allocated.
1478 QualType allocType = getContext().getBaseElementType(E->getAllocatedType());
1480 // 1. Build a call to the allocation function.
1481 FunctionDecl *allocator = E->getOperatorNew();
1483 // If there is a brace-initializer, cannot allocate fewer elements than inits.
1484 unsigned minElements = 0;
1485 if (E->isArray() && E->hasInitializer()) {
1486 const InitListExpr *ILE = dyn_cast<InitListExpr>(E->getInitializer());
1487 if (ILE && ILE->isStringLiteralInit())
1489 cast<ConstantArrayType>(ILE->getType()->getAsArrayTypeUnsafe())
1490 ->getSize().getZExtValue();
1492 minElements = ILE->getNumInits();
1495 llvm::Value *numElements = nullptr;
1496 llvm::Value *allocSizeWithoutCookie = nullptr;
1497 llvm::Value *allocSize =
1498 EmitCXXNewAllocSize(*this, E, minElements, numElements,
1499 allocSizeWithoutCookie);
1500 CharUnits allocAlign = getContext().getTypeAlignInChars(allocType);
1502 // Emit the allocation call. If the allocator is a global placement
1503 // operator, just "inline" it directly.
1504 Address allocation = Address::invalid();
1505 CallArgList allocatorArgs;
1506 if (allocator->isReservedGlobalPlacementOperator()) {
1507 assert(E->getNumPlacementArgs() == 1);
1508 const Expr *arg = *E->placement_arguments().begin();
1510 AlignmentSource alignSource;
1511 allocation = EmitPointerWithAlignment(arg, &alignSource);
1513 // The pointer expression will, in many cases, be an opaque void*.
1514 // In these cases, discard the computed alignment and use the
1515 // formal alignment of the allocated type.
1516 if (alignSource != AlignmentSource::Decl)
1517 allocation = Address(allocation.getPointer(), allocAlign);
1519 // Set up allocatorArgs for the call to operator delete if it's not
1520 // the reserved global operator.
1521 if (E->getOperatorDelete() &&
1522 !E->getOperatorDelete()->isReservedGlobalPlacementOperator()) {
1523 allocatorArgs.add(RValue::get(allocSize), getContext().getSizeType());
1524 allocatorArgs.add(RValue::get(allocation.getPointer()), arg->getType());
1528 const FunctionProtoType *allocatorType =
1529 allocator->getType()->castAs<FunctionProtoType>();
1530 unsigned ParamsToSkip = 0;
1532 // The allocation size is the first argument.
1533 QualType sizeType = getContext().getSizeType();
1534 allocatorArgs.add(RValue::get(allocSize), sizeType);
1537 if (allocSize != allocSizeWithoutCookie) {
1538 CharUnits cookieAlign = getSizeAlign(); // FIXME: Ask the ABI.
1539 allocAlign = std::max(allocAlign, cookieAlign);
1542 // The allocation alignment may be passed as the second argument.
1543 if (E->passAlignment()) {
1544 QualType AlignValT = sizeType;
1545 if (allocatorType->getNumParams() > 1) {
1546 AlignValT = allocatorType->getParamType(1);
1547 assert(getContext().hasSameUnqualifiedType(
1548 AlignValT->castAs<EnumType>()->getDecl()->getIntegerType(),
1550 "wrong type for alignment parameter");
1553 // Corner case, passing alignment to 'operator new(size_t, ...)'.
1554 assert(allocator->isVariadic() && "can't pass alignment to allocator");
1557 RValue::get(llvm::ConstantInt::get(SizeTy, allocAlign.getQuantity())),
1561 // FIXME: Why do we not pass a CalleeDecl here?
1562 EmitCallArgs(allocatorArgs, allocatorType, E->placement_arguments(),
1563 /*CalleeDecl*/nullptr, /*ParamsToSkip*/ParamsToSkip);
1566 EmitNewDeleteCall(*this, allocator, allocatorType, allocatorArgs);
1568 // If this was a call to a global replaceable allocation function that does
1569 // not take an alignment argument, the allocator is known to produce
1570 // storage that's suitably aligned for any object that fits, up to a known
1571 // threshold. Otherwise assume it's suitably aligned for the allocated type.
1572 CharUnits allocationAlign = allocAlign;
1573 if (!E->passAlignment() &&
1574 allocator->isReplaceableGlobalAllocationFunction()) {
1575 unsigned AllocatorAlign = llvm::PowerOf2Floor(std::min<uint64_t>(
1576 Target.getNewAlign(), getContext().getTypeSize(allocType)));
1577 allocationAlign = std::max(
1578 allocationAlign, getContext().toCharUnitsFromBits(AllocatorAlign));
1581 allocation = Address(RV.getScalarVal(), allocationAlign);
1584 // Emit a null check on the allocation result if the allocation
1585 // function is allowed to return null (because it has a non-throwing
1586 // exception spec or is the reserved placement new) and we have an
1587 // interesting initializer.
1588 bool nullCheck = E->shouldNullCheckAllocation(getContext()) &&
1589 (!allocType.isPODType(getContext()) || E->hasInitializer());
1591 llvm::BasicBlock *nullCheckBB = nullptr;
1592 llvm::BasicBlock *contBB = nullptr;
1594 // The null-check means that the initializer is conditionally
1596 ConditionalEvaluation conditional(*this);
1599 conditional.begin(*this);
1601 nullCheckBB = Builder.GetInsertBlock();
1602 llvm::BasicBlock *notNullBB = createBasicBlock("new.notnull");
1603 contBB = createBasicBlock("new.cont");
1605 llvm::Value *isNull =
1606 Builder.CreateIsNull(allocation.getPointer(), "new.isnull");
1607 Builder.CreateCondBr(isNull, contBB, notNullBB);
1608 EmitBlock(notNullBB);
1611 // If there's an operator delete, enter a cleanup to call it if an
1612 // exception is thrown.
1613 EHScopeStack::stable_iterator operatorDeleteCleanup;
1614 llvm::Instruction *cleanupDominator = nullptr;
1615 if (E->getOperatorDelete() &&
1616 !E->getOperatorDelete()->isReservedGlobalPlacementOperator()) {
1617 EnterNewDeleteCleanup(*this, E, allocation, allocSize, allocAlign,
1619 operatorDeleteCleanup = EHStack.stable_begin();
1620 cleanupDominator = Builder.CreateUnreachable();
1623 assert((allocSize == allocSizeWithoutCookie) ==
1624 CalculateCookiePadding(*this, E).isZero());
1625 if (allocSize != allocSizeWithoutCookie) {
1626 assert(E->isArray());
1627 allocation = CGM.getCXXABI().InitializeArrayCookie(*this, allocation,
1632 llvm::Type *elementTy = ConvertTypeForMem(allocType);
1633 Address result = Builder.CreateElementBitCast(allocation, elementTy);
1635 // Passing pointer through invariant.group.barrier to avoid propagation of
1636 // vptrs information which may be included in previous type.
1637 if (CGM.getCodeGenOpts().StrictVTablePointers &&
1638 CGM.getCodeGenOpts().OptimizationLevel > 0 &&
1639 allocator->isReservedGlobalPlacementOperator())
1640 result = Address(Builder.CreateInvariantGroupBarrier(result.getPointer()),
1641 result.getAlignment());
1643 EmitNewInitializer(*this, E, allocType, elementTy, result, numElements,
1644 allocSizeWithoutCookie);
1646 // NewPtr is a pointer to the base element type. If we're
1647 // allocating an array of arrays, we'll need to cast back to the
1648 // array pointer type.
1649 llvm::Type *resultType = ConvertTypeForMem(E->getType());
1650 if (result.getType() != resultType)
1651 result = Builder.CreateBitCast(result, resultType);
1654 // Deactivate the 'operator delete' cleanup if we finished
1656 if (operatorDeleteCleanup.isValid()) {
1657 DeactivateCleanupBlock(operatorDeleteCleanup, cleanupDominator);
1658 cleanupDominator->eraseFromParent();
1661 llvm::Value *resultPtr = result.getPointer();
1663 conditional.end(*this);
1665 llvm::BasicBlock *notNullBB = Builder.GetInsertBlock();
1668 llvm::PHINode *PHI = Builder.CreatePHI(resultPtr->getType(), 2);
1669 PHI->addIncoming(resultPtr, notNullBB);
1670 PHI->addIncoming(llvm::Constant::getNullValue(resultPtr->getType()),
1679 void CodeGenFunction::EmitDeleteCall(const FunctionDecl *DeleteFD,
1680 llvm::Value *Ptr, QualType DeleteTy,
1681 llvm::Value *NumElements,
1682 CharUnits CookieSize) {
1683 assert((!NumElements && CookieSize.isZero()) ||
1684 DeleteFD->getOverloadedOperator() == OO_Array_Delete);
1686 const FunctionProtoType *DeleteFTy =
1687 DeleteFD->getType()->getAs<FunctionProtoType>();
1689 CallArgList DeleteArgs;
1691 std::pair<bool, bool> PassSizeAndAlign =
1692 shouldPassSizeAndAlignToUsualDelete(DeleteFTy);
1694 auto ParamTypeIt = DeleteFTy->param_type_begin();
1696 // Pass the pointer itself.
1697 QualType ArgTy = *ParamTypeIt++;
1698 llvm::Value *DeletePtr = Builder.CreateBitCast(Ptr, ConvertType(ArgTy));
1699 DeleteArgs.add(RValue::get(DeletePtr), ArgTy);
1701 // Pass the size if the delete function has a size_t parameter.
1702 if (PassSizeAndAlign.first) {
1703 QualType SizeType = *ParamTypeIt++;
1704 CharUnits DeleteTypeSize = getContext().getTypeSizeInChars(DeleteTy);
1705 llvm::Value *Size = llvm::ConstantInt::get(ConvertType(SizeType),
1706 DeleteTypeSize.getQuantity());
1708 // For array new, multiply by the number of elements.
1710 Size = Builder.CreateMul(Size, NumElements);
1712 // If there is a cookie, add the cookie size.
1713 if (!CookieSize.isZero())
1714 Size = Builder.CreateAdd(
1715 Size, llvm::ConstantInt::get(SizeTy, CookieSize.getQuantity()));
1717 DeleteArgs.add(RValue::get(Size), SizeType);
1720 // Pass the alignment if the delete function has an align_val_t parameter.
1721 if (PassSizeAndAlign.second) {
1722 QualType AlignValType = *ParamTypeIt++;
1723 CharUnits DeleteTypeAlign = getContext().toCharUnitsFromBits(
1724 getContext().getTypeAlignIfKnown(DeleteTy));
1725 llvm::Value *Align = llvm::ConstantInt::get(ConvertType(AlignValType),
1726 DeleteTypeAlign.getQuantity());
1727 DeleteArgs.add(RValue::get(Align), AlignValType);
1730 assert(ParamTypeIt == DeleteFTy->param_type_end() &&
1731 "unknown parameter to usual delete function");
1733 // Emit the call to delete.
1734 EmitNewDeleteCall(*this, DeleteFD, DeleteFTy, DeleteArgs);
1738 /// Calls the given 'operator delete' on a single object.
1739 struct CallObjectDelete final : EHScopeStack::Cleanup {
1741 const FunctionDecl *OperatorDelete;
1742 QualType ElementType;
1744 CallObjectDelete(llvm::Value *Ptr,
1745 const FunctionDecl *OperatorDelete,
1746 QualType ElementType)
1747 : Ptr(Ptr), OperatorDelete(OperatorDelete), ElementType(ElementType) {}
1749 void Emit(CodeGenFunction &CGF, Flags flags) override {
1750 CGF.EmitDeleteCall(OperatorDelete, Ptr, ElementType);
1756 CodeGenFunction::pushCallObjectDeleteCleanup(const FunctionDecl *OperatorDelete,
1757 llvm::Value *CompletePtr,
1758 QualType ElementType) {
1759 EHStack.pushCleanup<CallObjectDelete>(NormalAndEHCleanup, CompletePtr,
1760 OperatorDelete, ElementType);
1763 /// Emit the code for deleting a single object.
1764 static void EmitObjectDelete(CodeGenFunction &CGF,
1765 const CXXDeleteExpr *DE,
1767 QualType ElementType) {
1768 // C++11 [expr.delete]p3:
1769 // If the static type of the object to be deleted is different from its
1770 // dynamic type, the static type shall be a base class of the dynamic type
1771 // of the object to be deleted and the static type shall have a virtual
1772 // destructor or the behavior is undefined.
1773 CGF.EmitTypeCheck(CodeGenFunction::TCK_MemberCall,
1774 DE->getExprLoc(), Ptr.getPointer(),
1777 // Find the destructor for the type, if applicable. If the
1778 // destructor is virtual, we'll just emit the vcall and return.
1779 const CXXDestructorDecl *Dtor = nullptr;
1780 if (const RecordType *RT = ElementType->getAs<RecordType>()) {
1781 CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
1782 if (RD->hasDefinition() && !RD->hasTrivialDestructor()) {
1783 Dtor = RD->getDestructor();
1785 if (Dtor->isVirtual()) {
1786 CGF.CGM.getCXXABI().emitVirtualObjectDelete(CGF, DE, Ptr, ElementType,
1793 // Make sure that we call delete even if the dtor throws.
1794 // This doesn't have to a conditional cleanup because we're going
1795 // to pop it off in a second.
1796 const FunctionDecl *OperatorDelete = DE->getOperatorDelete();
1797 CGF.EHStack.pushCleanup<CallObjectDelete>(NormalAndEHCleanup,
1799 OperatorDelete, ElementType);
1802 CGF.EmitCXXDestructorCall(Dtor, Dtor_Complete,
1803 /*ForVirtualBase=*/false,
1804 /*Delegating=*/false,
1806 else if (auto Lifetime = ElementType.getObjCLifetime()) {
1808 case Qualifiers::OCL_None:
1809 case Qualifiers::OCL_ExplicitNone:
1810 case Qualifiers::OCL_Autoreleasing:
1813 case Qualifiers::OCL_Strong:
1814 CGF.EmitARCDestroyStrong(Ptr, ARCPreciseLifetime);
1817 case Qualifiers::OCL_Weak:
1818 CGF.EmitARCDestroyWeak(Ptr);
1823 CGF.PopCleanupBlock();
1827 /// Calls the given 'operator delete' on an array of objects.
1828 struct CallArrayDelete final : EHScopeStack::Cleanup {
1830 const FunctionDecl *OperatorDelete;
1831 llvm::Value *NumElements;
1832 QualType ElementType;
1833 CharUnits CookieSize;
1835 CallArrayDelete(llvm::Value *Ptr,
1836 const FunctionDecl *OperatorDelete,
1837 llvm::Value *NumElements,
1838 QualType ElementType,
1839 CharUnits CookieSize)
1840 : Ptr(Ptr), OperatorDelete(OperatorDelete), NumElements(NumElements),
1841 ElementType(ElementType), CookieSize(CookieSize) {}
1843 void Emit(CodeGenFunction &CGF, Flags flags) override {
1844 CGF.EmitDeleteCall(OperatorDelete, Ptr, ElementType, NumElements,
1850 /// Emit the code for deleting an array of objects.
1851 static void EmitArrayDelete(CodeGenFunction &CGF,
1852 const CXXDeleteExpr *E,
1854 QualType elementType) {
1855 llvm::Value *numElements = nullptr;
1856 llvm::Value *allocatedPtr = nullptr;
1857 CharUnits cookieSize;
1858 CGF.CGM.getCXXABI().ReadArrayCookie(CGF, deletedPtr, E, elementType,
1859 numElements, allocatedPtr, cookieSize);
1861 assert(allocatedPtr && "ReadArrayCookie didn't set allocated pointer");
1863 // Make sure that we call delete even if one of the dtors throws.
1864 const FunctionDecl *operatorDelete = E->getOperatorDelete();
1865 CGF.EHStack.pushCleanup<CallArrayDelete>(NormalAndEHCleanup,
1866 allocatedPtr, operatorDelete,
1867 numElements, elementType,
1870 // Destroy the elements.
1871 if (QualType::DestructionKind dtorKind = elementType.isDestructedType()) {
1872 assert(numElements && "no element count for a type with a destructor!");
1874 CharUnits elementSize = CGF.getContext().getTypeSizeInChars(elementType);
1875 CharUnits elementAlign =
1876 deletedPtr.getAlignment().alignmentOfArrayElement(elementSize);
1878 llvm::Value *arrayBegin = deletedPtr.getPointer();
1879 llvm::Value *arrayEnd =
1880 CGF.Builder.CreateInBoundsGEP(arrayBegin, numElements, "delete.end");
1882 // Note that it is legal to allocate a zero-length array, and we
1883 // can never fold the check away because the length should always
1884 // come from a cookie.
1885 CGF.emitArrayDestroy(arrayBegin, arrayEnd, elementType, elementAlign,
1886 CGF.getDestroyer(dtorKind),
1887 /*checkZeroLength*/ true,
1888 CGF.needsEHCleanup(dtorKind));
1891 // Pop the cleanup block.
1892 CGF.PopCleanupBlock();
1895 void CodeGenFunction::EmitCXXDeleteExpr(const CXXDeleteExpr *E) {
1896 const Expr *Arg = E->getArgument();
1897 Address Ptr = EmitPointerWithAlignment(Arg);
1899 // Null check the pointer.
1900 llvm::BasicBlock *DeleteNotNull = createBasicBlock("delete.notnull");
1901 llvm::BasicBlock *DeleteEnd = createBasicBlock("delete.end");
1903 llvm::Value *IsNull = Builder.CreateIsNull(Ptr.getPointer(), "isnull");
1905 Builder.CreateCondBr(IsNull, DeleteEnd, DeleteNotNull);
1906 EmitBlock(DeleteNotNull);
1908 // We might be deleting a pointer to array. If so, GEP down to the
1909 // first non-array element.
1910 // (this assumes that A(*)[3][7] is converted to [3 x [7 x %A]]*)
1911 QualType DeleteTy = Arg->getType()->getAs<PointerType>()->getPointeeType();
1912 if (DeleteTy->isConstantArrayType()) {
1913 llvm::Value *Zero = Builder.getInt32(0);
1914 SmallVector<llvm::Value*,8> GEP;
1916 GEP.push_back(Zero); // point at the outermost array
1918 // For each layer of array type we're pointing at:
1919 while (const ConstantArrayType *Arr
1920 = getContext().getAsConstantArrayType(DeleteTy)) {
1921 // 1. Unpeel the array type.
1922 DeleteTy = Arr->getElementType();
1924 // 2. GEP to the first element of the array.
1925 GEP.push_back(Zero);
1928 Ptr = Address(Builder.CreateInBoundsGEP(Ptr.getPointer(), GEP, "del.first"),
1929 Ptr.getAlignment());
1932 assert(ConvertTypeForMem(DeleteTy) == Ptr.getElementType());
1934 if (E->isArrayForm()) {
1935 EmitArrayDelete(*this, E, Ptr, DeleteTy);
1937 EmitObjectDelete(*this, E, Ptr, DeleteTy);
1940 EmitBlock(DeleteEnd);
1943 static bool isGLValueFromPointerDeref(const Expr *E) {
1944 E = E->IgnoreParens();
1946 if (const auto *CE = dyn_cast<CastExpr>(E)) {
1947 if (!CE->getSubExpr()->isGLValue())
1949 return isGLValueFromPointerDeref(CE->getSubExpr());
1952 if (const auto *OVE = dyn_cast<OpaqueValueExpr>(E))
1953 return isGLValueFromPointerDeref(OVE->getSourceExpr());
1955 if (const auto *BO = dyn_cast<BinaryOperator>(E))
1956 if (BO->getOpcode() == BO_Comma)
1957 return isGLValueFromPointerDeref(BO->getRHS());
1959 if (const auto *ACO = dyn_cast<AbstractConditionalOperator>(E))
1960 return isGLValueFromPointerDeref(ACO->getTrueExpr()) ||
1961 isGLValueFromPointerDeref(ACO->getFalseExpr());
1963 // C++11 [expr.sub]p1:
1964 // The expression E1[E2] is identical (by definition) to *((E1)+(E2))
1965 if (isa<ArraySubscriptExpr>(E))
1968 if (const auto *UO = dyn_cast<UnaryOperator>(E))
1969 if (UO->getOpcode() == UO_Deref)
1975 static llvm::Value *EmitTypeidFromVTable(CodeGenFunction &CGF, const Expr *E,
1976 llvm::Type *StdTypeInfoPtrTy) {
1977 // Get the vtable pointer.
1978 Address ThisPtr = CGF.EmitLValue(E).getAddress();
1980 // C++ [expr.typeid]p2:
1981 // If the glvalue expression is obtained by applying the unary * operator to
1982 // a pointer and the pointer is a null pointer value, the typeid expression
1983 // throws the std::bad_typeid exception.
1985 // However, this paragraph's intent is not clear. We choose a very generous
1986 // interpretation which implores us to consider comma operators, conditional
1987 // operators, parentheses and other such constructs.
1988 QualType SrcRecordTy = E->getType();
1989 if (CGF.CGM.getCXXABI().shouldTypeidBeNullChecked(
1990 isGLValueFromPointerDeref(E), SrcRecordTy)) {
1991 llvm::BasicBlock *BadTypeidBlock =
1992 CGF.createBasicBlock("typeid.bad_typeid");
1993 llvm::BasicBlock *EndBlock = CGF.createBasicBlock("typeid.end");
1995 llvm::Value *IsNull = CGF.Builder.CreateIsNull(ThisPtr.getPointer());
1996 CGF.Builder.CreateCondBr(IsNull, BadTypeidBlock, EndBlock);
1998 CGF.EmitBlock(BadTypeidBlock);
1999 CGF.CGM.getCXXABI().EmitBadTypeidCall(CGF);
2000 CGF.EmitBlock(EndBlock);
2003 return CGF.CGM.getCXXABI().EmitTypeid(CGF, SrcRecordTy, ThisPtr,
2007 llvm::Value *CodeGenFunction::EmitCXXTypeidExpr(const CXXTypeidExpr *E) {
2008 llvm::Type *StdTypeInfoPtrTy =
2009 ConvertType(E->getType())->getPointerTo();
2011 if (E->isTypeOperand()) {
2012 llvm::Constant *TypeInfo =
2013 CGM.GetAddrOfRTTIDescriptor(E->getTypeOperand(getContext()));
2014 return Builder.CreateBitCast(TypeInfo, StdTypeInfoPtrTy);
2017 // C++ [expr.typeid]p2:
2018 // When typeid is applied to a glvalue expression whose type is a
2019 // polymorphic class type, the result refers to a std::type_info object
2020 // representing the type of the most derived object (that is, the dynamic
2021 // type) to which the glvalue refers.
2022 if (E->isPotentiallyEvaluated())
2023 return EmitTypeidFromVTable(*this, E->getExprOperand(),
2026 QualType OperandTy = E->getExprOperand()->getType();
2027 return Builder.CreateBitCast(CGM.GetAddrOfRTTIDescriptor(OperandTy),
2031 static llvm::Value *EmitDynamicCastToNull(CodeGenFunction &CGF,
2033 llvm::Type *DestLTy = CGF.ConvertType(DestTy);
2034 if (DestTy->isPointerType())
2035 return llvm::Constant::getNullValue(DestLTy);
2037 /// C++ [expr.dynamic.cast]p9:
2038 /// A failed cast to reference type throws std::bad_cast
2039 if (!CGF.CGM.getCXXABI().EmitBadCastCall(CGF))
2042 CGF.EmitBlock(CGF.createBasicBlock("dynamic_cast.end"));
2043 return llvm::UndefValue::get(DestLTy);
2046 llvm::Value *CodeGenFunction::EmitDynamicCast(Address ThisAddr,
2047 const CXXDynamicCastExpr *DCE) {
2048 CGM.EmitExplicitCastExprType(DCE, this);
2049 QualType DestTy = DCE->getTypeAsWritten();
2051 if (DCE->isAlwaysNull())
2052 if (llvm::Value *T = EmitDynamicCastToNull(*this, DestTy))
2055 QualType SrcTy = DCE->getSubExpr()->getType();
2057 // C++ [expr.dynamic.cast]p7:
2058 // If T is "pointer to cv void," then the result is a pointer to the most
2059 // derived object pointed to by v.
2060 const PointerType *DestPTy = DestTy->getAs<PointerType>();
2062 bool isDynamicCastToVoid;
2063 QualType SrcRecordTy;
2064 QualType DestRecordTy;
2066 isDynamicCastToVoid = DestPTy->getPointeeType()->isVoidType();
2067 SrcRecordTy = SrcTy->castAs<PointerType>()->getPointeeType();
2068 DestRecordTy = DestPTy->getPointeeType();
2070 isDynamicCastToVoid = false;
2071 SrcRecordTy = SrcTy;
2072 DestRecordTy = DestTy->castAs<ReferenceType>()->getPointeeType();
2075 assert(SrcRecordTy->isRecordType() && "source type must be a record type!");
2077 // C++ [expr.dynamic.cast]p4:
2078 // If the value of v is a null pointer value in the pointer case, the result
2079 // is the null pointer value of type T.
2080 bool ShouldNullCheckSrcValue =
2081 CGM.getCXXABI().shouldDynamicCastCallBeNullChecked(SrcTy->isPointerType(),
2084 llvm::BasicBlock *CastNull = nullptr;
2085 llvm::BasicBlock *CastNotNull = nullptr;
2086 llvm::BasicBlock *CastEnd = createBasicBlock("dynamic_cast.end");
2088 if (ShouldNullCheckSrcValue) {
2089 CastNull = createBasicBlock("dynamic_cast.null");
2090 CastNotNull = createBasicBlock("dynamic_cast.notnull");
2092 llvm::Value *IsNull = Builder.CreateIsNull(ThisAddr.getPointer());
2093 Builder.CreateCondBr(IsNull, CastNull, CastNotNull);
2094 EmitBlock(CastNotNull);
2098 if (isDynamicCastToVoid) {
2099 Value = CGM.getCXXABI().EmitDynamicCastToVoid(*this, ThisAddr, SrcRecordTy,
2102 assert(DestRecordTy->isRecordType() &&
2103 "destination type must be a record type!");
2104 Value = CGM.getCXXABI().EmitDynamicCastCall(*this, ThisAddr, SrcRecordTy,
2105 DestTy, DestRecordTy, CastEnd);
2106 CastNotNull = Builder.GetInsertBlock();
2109 if (ShouldNullCheckSrcValue) {
2110 EmitBranch(CastEnd);
2112 EmitBlock(CastNull);
2113 EmitBranch(CastEnd);
2118 if (ShouldNullCheckSrcValue) {
2119 llvm::PHINode *PHI = Builder.CreatePHI(Value->getType(), 2);
2120 PHI->addIncoming(Value, CastNotNull);
2121 PHI->addIncoming(llvm::Constant::getNullValue(Value->getType()), CastNull);
2129 void CodeGenFunction::EmitLambdaExpr(const LambdaExpr *E, AggValueSlot Slot) {
2130 RunCleanupsScope Scope(*this);
2131 LValue SlotLV = MakeAddrLValue(Slot.getAddress(), E->getType());
2133 CXXRecordDecl::field_iterator CurField = E->getLambdaClass()->field_begin();
2134 for (LambdaExpr::const_capture_init_iterator i = E->capture_init_begin(),
2135 e = E->capture_init_end();
2136 i != e; ++i, ++CurField) {
2137 // Emit initialization
2138 LValue LV = EmitLValueForFieldInitialization(SlotLV, *CurField);
2139 if (CurField->hasCapturedVLAType()) {
2140 auto VAT = CurField->getCapturedVLAType();
2141 EmitStoreThroughLValue(RValue::get(VLASizeMap[VAT->getSizeExpr()]), LV);
2143 EmitInitializerForField(*CurField, LV, *i);