1//===--- CGExprCXX.cpp - Emit LLVM Code for C++ expressions ---------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This contains code dealing with code generation of C++ expressions
10//
11//===----------------------------------------------------------------------===//
12
13#include "CGCUDARuntime.h"
14#include "CGCXXABI.h"
15#include "CGDebugInfo.h"
16#include "CGObjCRuntime.h"
17#include "CodeGenFunction.h"
18#include "ConstantEmitter.h"
19#include "TargetInfo.h"
20#include "clang/Basic/CodeGenOptions.h"
21#include "clang/CodeGen/CGFunctionInfo.h"
22#include "llvm/IR/Intrinsics.h"
23
24using namespace clang;
25using namespace CodeGen;
26
27namespace {
28struct MemberCallInfo {
29 RequiredArgs ReqArgs;
30 // Number of prefix arguments for the call. Ignores the `this` pointer.
31 unsigned PrefixSize;
32};
33} // namespace
34
35static MemberCallInfo
36commonEmitCXXMemberOrOperatorCall(CodeGenFunction &CGF, GlobalDecl GD,
37 llvm::Value *This, llvm::Value *ImplicitParam,
38 QualType ImplicitParamTy, const CallExpr *CE,
39 CallArgList &Args, CallArgList *RtlArgs) {
40 auto *MD = cast<CXXMethodDecl>(Val: GD.getDecl());
41
42 assert(CE == nullptr || isa<CXXMemberCallExpr>(CE) ||
43 isa<CXXOperatorCallExpr>(CE));
44 assert(MD->isImplicitObjectMemberFunction() &&
45 "Trying to emit a member or operator call expr on a static method!");
46
47 // Push the this ptr.
48 const CXXRecordDecl *RD =
49 CGF.CGM.getCXXABI().getThisArgumentTypeForMethod(GD);
50 Args.add(rvalue: RValue::get(V: This), type: CGF.getTypes().DeriveThisType(RD, MD));
51
52 // If there is an implicit parameter (e.g. VTT), emit it.
53 if (ImplicitParam) {
54 Args.add(rvalue: RValue::get(V: ImplicitParam), type: ImplicitParamTy);
55 }
56
57 const FunctionProtoType *FPT = MD->getType()->castAs<FunctionProtoType>();
58 RequiredArgs required = RequiredArgs::forPrototypePlus(prototype: FPT, additional: Args.size());
59 unsigned PrefixSize = Args.size() - 1;
60
61 // And the rest of the call args.
62 if (RtlArgs) {
63 // Special case: if the caller emitted the arguments right-to-left already
64 // (prior to emitting the *this argument), we're done. This happens for
65 // assignment operators.
66 Args.addFrom(other: *RtlArgs);
67 } else if (CE) {
68 // Special case: skip first argument of CXXOperatorCall (it is "this").
69 unsigned ArgsToSkip = 0;
70 if (const auto *Op = dyn_cast<CXXOperatorCallExpr>(Val: CE)) {
71 if (const auto *M = dyn_cast<CXXMethodDecl>(Val: Op->getCalleeDecl()))
72 ArgsToSkip =
73 static_cast<unsigned>(!M->isExplicitObjectMemberFunction());
74 }
75 CGF.EmitCallArgs(Args, Prototype: FPT, ArgRange: drop_begin(RangeOrContainer: CE->arguments(), N: ArgsToSkip),
76 AC: CE->getDirectCallee());
77 } else {
78 assert(
79 FPT->getNumParams() == 0 &&
80 "No CallExpr specified for function with non-zero number of arguments");
81 }
82 return {.ReqArgs: required, .PrefixSize: PrefixSize};
83}
84
85RValue CodeGenFunction::EmitCXXMemberOrOperatorCall(
86 const CXXMethodDecl *MD, const CGCallee &Callee,
87 ReturnValueSlot ReturnValue, llvm::Value *This, llvm::Value *ImplicitParam,
88 QualType ImplicitParamTy, const CallExpr *CE, CallArgList *RtlArgs,
89 llvm::CallBase **CallOrInvoke) {
90 const FunctionProtoType *FPT = MD->getType()->castAs<FunctionProtoType>();
91 CallArgList Args;
92 MemberCallInfo CallInfo = commonEmitCXXMemberOrOperatorCall(
93 CGF&: *this, GD: MD, This, ImplicitParam, ImplicitParamTy, CE, Args, RtlArgs);
94 auto &FnInfo = CGM.getTypes().arrangeCXXMethodCall(
95 args: Args, type: FPT, required: CallInfo.ReqArgs, numPrefixArgs: CallInfo.PrefixSize,
96 ABIInfoFD: getCurrentFunctionDecl());
97 return EmitCall(CallInfo: FnInfo, Callee, ReturnValue, Args, CallOrInvoke,
98 IsMustTail: CE && CE == MustTailCall,
99 Loc: CE ? CE->getExprLoc() : SourceLocation());
100}
101
102RValue CodeGenFunction::EmitCXXDestructorCall(
103 GlobalDecl Dtor, const CGCallee &Callee, llvm::Value *This, QualType ThisTy,
104 llvm::Value *ImplicitParam, QualType ImplicitParamTy, const CallExpr *CE,
105 llvm::CallBase **CallOrInvoke) {
106 const CXXMethodDecl *DtorDecl = cast<CXXMethodDecl>(Val: Dtor.getDecl());
107
108 assert(!ThisTy.isNull());
109 assert(ThisTy->getAsCXXRecordDecl() == DtorDecl->getParent() &&
110 "Pointer/Object mixup");
111
112 LangAS SrcAS = ThisTy.getAddressSpace();
113 LangAS DstAS = DtorDecl->getMethodQualifiers().getAddressSpace();
114 if (SrcAS != DstAS) {
115 QualType DstTy = DtorDecl->getThisType();
116 llvm::Type *NewType = CGM.getTypes().ConvertType(T: DstTy);
117 This = performAddrSpaceCast(Src: This, DestTy: NewType);
118 }
119
120 CallArgList Args;
121 commonEmitCXXMemberOrOperatorCall(CGF&: *this, GD: Dtor, This, ImplicitParam,
122 ImplicitParamTy, CE, Args, RtlArgs: nullptr);
123 return EmitCall(CallInfo: CGM.getTypes().arrangeCXXStructorDeclaration(GD: Dtor), Callee,
124 ReturnValue: ReturnValueSlot(), Args, CallOrInvoke,
125 IsMustTail: CE && CE == MustTailCall,
126 Loc: CE ? CE->getExprLoc() : SourceLocation{});
127}
128
129RValue
130CodeGenFunction::EmitCXXPseudoDestructorExpr(const CXXPseudoDestructorExpr *E) {
131 QualType DestroyedType = E->getDestroyedType();
132 if (DestroyedType.hasStrongOrWeakObjCLifetime()) {
133 // Automatic Reference Counting:
134 // If the pseudo-expression names a retainable object with weak or
135 // strong lifetime, the object shall be released.
136 Expr *BaseExpr = E->getBase();
137 Address BaseValue = Address::invalid();
138 Qualifiers BaseQuals;
139
140 // If this is s.x, emit s as an lvalue. If it is s->x, emit s as a scalar.
141 if (E->isArrow()) {
142 BaseValue = EmitPointerWithAlignment(Addr: BaseExpr);
143 const auto *PTy = BaseExpr->getType()->castAs<PointerType>();
144 BaseQuals = PTy->getPointeeType().getQualifiers();
145 } else {
146 LValue BaseLV = EmitLValue(E: BaseExpr);
147 BaseValue = BaseLV.getAddress();
148 QualType BaseTy = BaseExpr->getType();
149 BaseQuals = BaseTy.getQualifiers();
150 }
151
152 switch (DestroyedType.getObjCLifetime()) {
153 case Qualifiers::OCL_None:
154 case Qualifiers::OCL_ExplicitNone:
155 case Qualifiers::OCL_Autoreleasing:
156 break;
157
158 case Qualifiers::OCL_Strong:
159 EmitARCRelease(
160 value: Builder.CreateLoad(Addr: BaseValue, IsVolatile: DestroyedType.isVolatileQualified()),
161 precise: ARCPreciseLifetime);
162 break;
163
164 case Qualifiers::OCL_Weak:
165 EmitARCDestroyWeak(addr: BaseValue);
166 break;
167 }
168 } else {
169 // C++ [expr.pseudo]p1:
170 // The result shall only be used as the operand for the function call
171 // operator (), and the result of such a call has type void. The only
172 // effect is the evaluation of the postfix-expression before the dot or
173 // arrow.
174 EmitIgnoredExpr(E: E->getBase());
175 }
176
177 return RValue::get(V: nullptr);
178}
179
180static CXXRecordDecl *getCXXRecord(const Expr *E) {
181 QualType T = E->getType();
182 if (const PointerType *PTy = T->getAs<PointerType>())
183 T = PTy->getPointeeType();
184 return T->castAsCXXRecordDecl();
185}
186
187// Note: This function also emit constructor calls to support a MSVC
188// extensions allowing explicit constructor function call.
189RValue CodeGenFunction::EmitCXXMemberCallExpr(const CXXMemberCallExpr *CE,
190 ReturnValueSlot ReturnValue,
191 llvm::CallBase **CallOrInvoke) {
192 const Expr *callee = CE->getCallee()->IgnoreParens();
193
194 if (isa<BinaryOperator>(Val: callee))
195 return EmitCXXMemberPointerCallExpr(E: CE, ReturnValue, CallOrInvoke);
196
197 const MemberExpr *ME = cast<MemberExpr>(Val: callee);
198 const CXXMethodDecl *MD = cast<CXXMethodDecl>(Val: ME->getMemberDecl());
199
200 if (MD->isStatic()) {
201 // The method is static, emit it as we would a regular call.
202 CGCallee callee =
203 CGCallee::forDirect(functionPtr: CGM.GetAddrOfFunction(GD: MD), abstractInfo: GlobalDecl(MD));
204 return EmitCall(FnType: getContext().getPointerType(T: MD->getType()), Callee: callee, E: CE,
205 ReturnValue, /*Chain=*/nullptr, CallOrInvoke);
206 }
207
208 bool HasQualifier = ME->hasQualifier();
209 NestedNameSpecifier Qualifier = ME->getQualifier();
210 bool IsArrow = ME->isArrow();
211 const Expr *Base = ME->getBase();
212
213 return EmitCXXMemberOrOperatorMemberCallExpr(CE, MD, ReturnValue,
214 HasQualifier, Qualifier, IsArrow,
215 Base, CallOrInvoke);
216}
217
218RValue CodeGenFunction::EmitCXXMemberOrOperatorMemberCallExpr(
219 const CallExpr *CE, const CXXMethodDecl *MD, ReturnValueSlot ReturnValue,
220 bool HasQualifier, NestedNameSpecifier Qualifier, bool IsArrow,
221 const Expr *Base, llvm::CallBase **CallOrInvoke) {
222 assert(isa<CXXMemberCallExpr>(CE) || isa<CXXOperatorCallExpr>(CE));
223
224 // Compute the object pointer.
225 bool CanUseVirtualCall = MD->isVirtual() && !HasQualifier;
226
227 const CXXMethodDecl *DevirtualizedMethod = nullptr;
228 if (CanUseVirtualCall &&
229 MD->getDevirtualizedMethod(Base, IsAppleKext: getLangOpts().AppleKext)) {
230 const CXXRecordDecl *BestDynamicDecl = Base->getBestDynamicClassType();
231 DevirtualizedMethod = MD->getCorrespondingMethodInClass(RD: BestDynamicDecl);
232 assert(DevirtualizedMethod);
233 const CXXRecordDecl *DevirtualizedClass = DevirtualizedMethod->getParent();
234 const Expr *Inner = Base->IgnoreParenBaseCasts();
235 if (DevirtualizedMethod->getReturnType().getCanonicalType() !=
236 MD->getReturnType().getCanonicalType())
237 // If the return types are not the same, this might be a case where more
238 // code needs to run to compensate for it. For example, the derived
239 // method might return a type that inherits form from the return
240 // type of MD and has a prefix.
241 // For now we just avoid devirtualizing these covariant cases.
242 DevirtualizedMethod = nullptr;
243 else if (getCXXRecord(E: Inner) == DevirtualizedClass)
244 // If the class of the Inner expression is where the dynamic method
245 // is defined, build the this pointer from it.
246 Base = Inner;
247 else if (getCXXRecord(E: Base) != DevirtualizedClass) {
248 // If the method is defined in a class that is not the best dynamic
249 // one or the one of the full expression, we would have to build
250 // a derived-to-base cast to compute the correct this pointer, but
251 // we don't have support for that yet, so do a virtual call.
252 DevirtualizedMethod = nullptr;
253 }
254 }
255
256 bool TrivialForCodegen =
257 MD->isTrivial() || (MD->isDefaulted() && MD->getParent()->isUnion());
258 bool TrivialAssignment =
259 TrivialForCodegen &&
260 (MD->isCopyAssignmentOperator() || MD->isMoveAssignmentOperator()) &&
261 !MD->getParent()->mayInsertExtraPadding();
262
263 // C++17 demands that we evaluate the RHS of a (possibly-compound) assignment
264 // operator before the LHS.
265 CallArgList RtlArgStorage;
266 CallArgList *RtlArgs = nullptr;
267 LValue TrivialAssignmentRHS;
268 if (auto *OCE = dyn_cast<CXXOperatorCallExpr>(Val: CE)) {
269 if (OCE->isAssignmentOp()) {
270 if (TrivialAssignment) {
271 TrivialAssignmentRHS = EmitCheckedLValue(E: CE->getArg(Arg: 1), TCK: TCK_Load);
272 } else {
273 RtlArgs = &RtlArgStorage;
274 EmitCallArgs(Args&: *RtlArgs, Prototype: MD->getType()->castAs<FunctionProtoType>(),
275 ArgRange: drop_begin(RangeOrContainer: CE->arguments(), N: 1), AC: CE->getDirectCallee(),
276 /*ParamsToSkip*/ 0, Order: EvaluationOrder::ForceRightToLeft);
277 }
278 }
279 }
280
281 auto getLValueForThis = [this, IsArrow,
282 Base](bool EmitCheckedForStore = false) {
283 // FIXME: Respect EmitCheckedForStore for the IsArrow case.
284 if (IsArrow) {
285 LValueBaseInfo BaseInfo;
286 TBAAAccessInfo TBAAInfo;
287 Address ThisValue = EmitPointerWithAlignment(Addr: Base, BaseInfo: &BaseInfo, TBAAInfo: &TBAAInfo);
288 return MakeAddrLValue(Addr: ThisValue, T: Base->getType()->getPointeeType(),
289 BaseInfo, TBAAInfo);
290 }
291 if (EmitCheckedForStore)
292 return EmitCheckedLValue(E: Base, TCK: TCK_Store);
293 return EmitLValue(E: Base);
294 };
295
296 if (const CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Val: MD)) {
297 // This is the MSVC p->Ctor::Ctor(...) extension. We assume that's
298 // constructing a new complete object of type Ctor.
299 assert(!RtlArgs);
300 assert(ReturnValue.isNull() && "Constructor shouldn't have return value");
301 LValue This = getLValueForThis();
302 CallArgList Args;
303 commonEmitCXXMemberOrOperatorCall(
304 CGF&: *this, GD: {Ctor, Ctor_Complete}, This: This.getPointer(CGF&: *this),
305 /*ImplicitParam=*/nullptr,
306 /*ImplicitParamTy=*/QualType(), CE, Args, RtlArgs: nullptr);
307
308 EmitCXXConstructorCall(D: Ctor, Type: Ctor_Complete, /*ForVirtualBase=*/false,
309 /*Delegating=*/false, This: This.getAddress(), Args,
310 Overlap: AggValueSlot::DoesNotOverlap, Loc: CE->getExprLoc(),
311 /*NewPointerIsChecked=*/false, CallOrInvoke);
312 return RValue::get(V: nullptr);
313 }
314
315 if (TrivialForCodegen) {
316 if (isa<CXXDestructorDecl>(Val: MD)) {
317 (void)getLValueForThis(); // Emit LHS for side effects.
318 return RValue::get(V: nullptr);
319 }
320
321 if (TrivialAssignment) {
322 // We don't like to generate the trivial copy/move assignment operator
323 // when it isn't necessary; just produce the proper effect here.
324 LValue This = getLValueForThis(/*EmitCheckedForStore=*/true);
325
326 // It's important that we use the result of EmitCheckedLValue here rather
327 // than emitting call arguments, in order to preserve TBAA information
328 // from the RHS.
329 LValue RHS = isa<CXXOperatorCallExpr>(Val: CE)
330 ? TrivialAssignmentRHS
331 : EmitCheckedLValue(E: *CE->arg_begin(), TCK: TCK_Load);
332 EmitAggregateAssign(Dest: This, Src: RHS, EltTy: CE->getType());
333 return RValue::get(V: This.getPointer(CGF&: *this));
334 }
335
336 assert(MD->getParent()->mayInsertExtraPadding() &&
337 "unknown trivial member function");
338 }
339
340 // Compute the function type we're calling.
341 const CXXMethodDecl *CalleeDecl =
342 DevirtualizedMethod ? DevirtualizedMethod : MD;
343 const CGFunctionInfo *FInfo = nullptr;
344 if (const auto *Dtor = dyn_cast<CXXDestructorDecl>(Val: CalleeDecl))
345 FInfo = &CGM.getTypes().arrangeCXXStructorDeclaration(
346 GD: GlobalDecl(Dtor, Dtor_Complete));
347 else
348 FInfo = &CGM.getTypes().arrangeCXXMethodDeclaration(MD: CalleeDecl);
349
350 llvm::FunctionType *Ty = CGM.getTypes().GetFunctionType(Info: *FInfo);
351
352 // C++11 [class.mfct.non-static]p2:
353 // If a non-static member function of a class X is called for an object that
354 // is not of type X, or of a type derived from X, the behavior is undefined.
355 SourceLocation CallLoc;
356 ASTContext &C = getContext();
357 if (CE)
358 CallLoc = CE->getExprLoc();
359
360 SanitizerSet SkippedChecks;
361 if (const auto *CMCE = dyn_cast<CXXMemberCallExpr>(Val: CE)) {
362 auto *IOA = CMCE->getImplicitObjectArgument();
363 bool IsImplicitObjectCXXThis = IsWrappedCXXThis(E: IOA);
364 if (IsImplicitObjectCXXThis)
365 SkippedChecks.set(K: SanitizerKind::Alignment, Value: true);
366 if (IsImplicitObjectCXXThis || isa<DeclRefExpr>(Val: IOA))
367 SkippedChecks.set(K: SanitizerKind::Null, Value: true);
368 }
369
370 LValue This = getLValueForThis();
371 if (sanitizePerformTypeCheck())
372 EmitTypeCheck(TCK: CodeGenFunction::TCK_MemberCall, Loc: CallLoc,
373 V: This.emitRawPointer(CGF&: *this),
374 Type: C.getCanonicalTagType(TD: CalleeDecl->getParent()),
375 /*Alignment=*/CharUnits::Zero(), SkippedChecks);
376
377 // C++ [class.virtual]p12:
378 // Explicit qualification with the scope operator (5.1) suppresses the
379 // virtual call mechanism.
380 //
381 // We also don't emit a virtual call if the base expression has a record type
382 // because then we know what the type is.
383 bool UseVirtualCall = CanUseVirtualCall && !DevirtualizedMethod;
384
385 if (const CXXDestructorDecl *Dtor = dyn_cast<CXXDestructorDecl>(Val: CalleeDecl)) {
386 assert(CE->arguments().empty() &&
387 "Destructor shouldn't have explicit parameters");
388 assert(ReturnValue.isNull() && "Destructor shouldn't have return value");
389 if (UseVirtualCall) {
390 CGM.getCXXABI().EmitVirtualDestructorCall(
391 CGF&: *this, Dtor, DtorType: Dtor_Complete, This: This.getAddress(),
392 E: cast<CXXMemberCallExpr>(Val: CE), CallOrInvoke);
393 } else {
394 GlobalDecl GD(Dtor, Dtor_Complete);
395 CGCallee Callee;
396 if (getLangOpts().AppleKext && Dtor->isVirtual() && HasQualifier)
397 Callee = BuildAppleKextVirtualCall(MD: Dtor, Qual: Qualifier, Ty);
398 else if (!DevirtualizedMethod)
399 Callee =
400 CGCallee::forDirect(functionPtr: CGM.getAddrOfCXXStructor(GD, FnInfo: FInfo, FnType: Ty), abstractInfo: GD);
401 else {
402 Callee = CGCallee::forDirect(functionPtr: CGM.GetAddrOfFunction(GD, Ty), abstractInfo: GD);
403 }
404
405 QualType ThisTy =
406 IsArrow ? Base->getType()->getPointeeType() : Base->getType();
407 EmitCXXDestructorCall(Dtor: GD, Callee, This: This.getPointer(CGF&: *this), ThisTy,
408 /*ImplicitParam=*/nullptr,
409 /*ImplicitParamTy=*/QualType(), CE, CallOrInvoke);
410 }
411 return RValue::get(V: nullptr);
412 }
413
414 // FIXME: Uses of 'MD' past this point need to be audited. We may need to use
415 // 'CalleeDecl' instead.
416
417 CGCallee Callee;
418 if (UseVirtualCall) {
419 Callee = CGCallee::forVirtual(CE, MD, Addr: This.getAddress(), FTy: Ty);
420 } else {
421 if (SanOpts.has(K: SanitizerKind::CFINVCall) &&
422 MD->getParent()->isDynamicClass()) {
423 llvm::Value *VTable;
424 const CXXRecordDecl *RD;
425 std::tie(args&: VTable, args&: RD) = CGM.getCXXABI().LoadVTablePtr(
426 CGF&: *this, This: This.getAddress(), RD: CalleeDecl->getParent());
427 EmitVTablePtrCheckForCall(RD, VTable, TCK: CFITCK_NVCall, Loc: CE->getBeginLoc());
428 }
429
430 if (getLangOpts().AppleKext && MD->isVirtual() && HasQualifier)
431 Callee = BuildAppleKextVirtualCall(MD, Qual: Qualifier, Ty);
432 else if (!DevirtualizedMethod)
433 Callee =
434 CGCallee::forDirect(functionPtr: CGM.GetAddrOfFunction(GD: MD, Ty), abstractInfo: GlobalDecl(MD));
435 else {
436 Callee =
437 CGCallee::forDirect(functionPtr: CGM.GetAddrOfFunction(GD: DevirtualizedMethod, Ty),
438 abstractInfo: GlobalDecl(DevirtualizedMethod));
439 }
440 }
441
442 if (MD->isVirtual()) {
443 Address NewThisAddr =
444 CGM.getCXXABI().adjustThisArgumentForVirtualFunctionCall(
445 CGF&: *this, GD: CalleeDecl, This: This.getAddress(), VirtualCall: UseVirtualCall);
446 This.setAddress(NewThisAddr);
447 }
448
449 return EmitCXXMemberOrOperatorCall(
450 MD: CalleeDecl, Callee, ReturnValue, This: This.getPointer(CGF&: *this),
451 /*ImplicitParam=*/nullptr, ImplicitParamTy: QualType(), CE, RtlArgs, CallOrInvoke);
452}
453
454RValue
455CodeGenFunction::EmitCXXMemberPointerCallExpr(const CXXMemberCallExpr *E,
456 ReturnValueSlot ReturnValue,
457 llvm::CallBase **CallOrInvoke) {
458 const BinaryOperator *BO =
459 cast<BinaryOperator>(Val: E->getCallee()->IgnoreParens());
460 const Expr *BaseExpr = BO->getLHS();
461 const Expr *MemFnExpr = BO->getRHS();
462
463 const auto *MPT = MemFnExpr->getType()->castAs<MemberPointerType>();
464 const auto *FPT = MPT->getPointeeType()->castAs<FunctionProtoType>();
465 const auto *RD = MPT->getMostRecentCXXRecordDecl();
466
467 // Emit the 'this' pointer.
468 Address This = Address::invalid();
469 if (BO->getOpcode() == BO_PtrMemI)
470 This = EmitPointerWithAlignment(Addr: BaseExpr, BaseInfo: nullptr, TBAAInfo: nullptr, IsKnownNonNull: KnownNonNull);
471 else
472 This = EmitLValue(E: BaseExpr, IsKnownNonNull: KnownNonNull).getAddress();
473
474 CanQualType ClassType = CGM.getContext().getCanonicalTagType(TD: RD);
475 EmitTypeCheck(TCK: TCK_MemberCall, Loc: E->getExprLoc(), V: This.emitRawPointer(CGF&: *this),
476 Type: ClassType);
477
478 // Get the member function pointer.
479 llvm::Value *MemFnPtr = EmitScalarExpr(E: MemFnExpr);
480
481 // Ask the ABI to load the callee. Note that This is modified.
482 llvm::Value *ThisPtrForCall = nullptr;
483 CGCallee Callee = CGM.getCXXABI().EmitLoadOfMemberFunctionPointer(
484 CGF&: *this, E: BO, This, ThisPtrForCall, MemPtr: MemFnPtr, MPT);
485
486 CallArgList Args;
487
488 QualType ThisType = getContext().getPointerType(T: ClassType);
489
490 // Push the this ptr.
491 Args.add(rvalue: RValue::get(V: ThisPtrForCall), type: ThisType);
492
493 RequiredArgs required = RequiredArgs::forPrototypePlus(prototype: FPT, additional: 1);
494
495 // And the rest of the call args
496 EmitCallArgs(Args, Prototype: FPT, ArgRange: E->arguments());
497 return EmitCall(CallInfo: CGM.getTypes().arrangeCXXMethodCall(args: Args, type: FPT, required,
498 /*PrefixSize=*/numPrefixArgs: 0,
499 ABIInfoFD: getCurrentFunctionDecl()),
500 Callee, ReturnValue, Args, CallOrInvoke, IsMustTail: E == MustTailCall,
501 Loc: E->getExprLoc());
502}
503
504RValue CodeGenFunction::EmitCXXOperatorMemberCallExpr(
505 const CXXOperatorCallExpr *E, const CXXMethodDecl *MD,
506 ReturnValueSlot ReturnValue, llvm::CallBase **CallOrInvoke) {
507 assert(MD->isImplicitObjectMemberFunction() &&
508 "Trying to emit a member call expr on a static method!");
509 return EmitCXXMemberOrOperatorMemberCallExpr(
510 CE: E, MD, ReturnValue, /*HasQualifier=*/false, /*Qualifier=*/std::nullopt,
511 /*IsArrow=*/false, Base: E->getArg(Arg: 0), CallOrInvoke);
512}
513
514RValue CodeGenFunction::EmitCUDAKernelCallExpr(const CUDAKernelCallExpr *E,
515 ReturnValueSlot ReturnValue,
516 llvm::CallBase **CallOrInvoke) {
517 // Emit as a device kernel call if CUDA device code is to be generated.
518 // TODO: implement for HIP
519 if (!getLangOpts().HIP && getLangOpts().CUDAIsDevice)
520 return CGM.getCUDARuntime().EmitCUDADeviceKernelCallExpr(
521 CGF&: *this, E, ReturnValue, CallOrInvoke);
522 return CGM.getCUDARuntime().EmitCUDAKernelCallExpr(CGF&: *this, E, ReturnValue,
523 CallOrInvoke);
524}
525
526static void EmitNullBaseClassInitialization(CodeGenFunction &CGF,
527 Address DestPtr,
528 const CXXRecordDecl *Base) {
529 if (Base->isEmpty())
530 return;
531
532 DestPtr = DestPtr.withElementType(ElemTy: CGF.Int8Ty);
533
534 const ASTRecordLayout &Layout = CGF.getContext().getASTRecordLayout(D: Base);
535 CharUnits NVSize = Layout.getNonVirtualSize();
536
537 // We cannot simply zero-initialize the entire base sub-object if vbptrs are
538 // present, they are initialized by the most derived class before calling the
539 // constructor.
540 SmallVector<std::pair<CharUnits, CharUnits>, 1> Stores;
541 Stores.emplace_back(Args: CharUnits::Zero(), Args&: NVSize);
542
543 // Each store is split by the existence of a vbptr.
544 CharUnits VBPtrWidth = CGF.getPointerSize();
545 std::vector<CharUnits> VBPtrOffsets =
546 CGF.CGM.getCXXABI().getVBPtrOffsets(RD: Base);
547 for (CharUnits VBPtrOffset : VBPtrOffsets) {
548 // Stop before we hit any virtual base pointers located in virtual bases.
549 if (VBPtrOffset >= NVSize)
550 break;
551 std::pair<CharUnits, CharUnits> LastStore = Stores.pop_back_val();
552 CharUnits LastStoreOffset = LastStore.first;
553
554 CharUnits SplitBeforeOffset = LastStoreOffset;
555 CharUnits SplitBeforeSize = VBPtrOffset - SplitBeforeOffset;
556 assert(!SplitBeforeSize.isNegative() && "negative store size!");
557 if (!SplitBeforeSize.isZero())
558 Stores.emplace_back(Args&: SplitBeforeOffset, Args&: SplitBeforeSize);
559
560 CharUnits SplitAfterOffset = VBPtrOffset + VBPtrWidth;
561 CharUnits SplitAfterSize = NVSize - SplitAfterOffset;
562 assert(!SplitAfterSize.isNegative() && "negative store size!");
563 if (!SplitAfterSize.isZero())
564 Stores.emplace_back(Args&: SplitAfterOffset, Args&: SplitAfterSize);
565 }
566
567 // If the type contains a pointer to data member we can't memset it to zero.
568 // Instead, create a null constant and copy it to the destination.
569 // TODO: there are other patterns besides zero that we can usefully memset,
570 // like -1, which happens to be the pattern used by member-pointers.
571 // TODO: isZeroInitializable can be over-conservative in the case where a
572 // virtual base contains a member pointer.
573 llvm::Constant *NullConstantForBase = CGF.CGM.EmitNullConstantForBase(Record: Base);
574 if (!NullConstantForBase->isNullValue()) {
575 llvm::GlobalVariable *NullVariable = new llvm::GlobalVariable(
576 CGF.CGM.getModule(), NullConstantForBase->getType(),
577 /*isConstant=*/true, llvm::GlobalVariable::PrivateLinkage,
578 NullConstantForBase, Twine());
579
580 CharUnits Align =
581 std::max(a: Layout.getNonVirtualAlignment(), b: DestPtr.getAlignment());
582 NullVariable->setAlignment(Align.getAsAlign());
583
584 Address SrcPtr(NullVariable, CGF.Int8Ty, Align);
585
586 // Get and call the appropriate llvm.memcpy overload.
587 for (std::pair<CharUnits, CharUnits> Store : Stores) {
588 CharUnits StoreOffset = Store.first;
589 CharUnits StoreSize = Store.second;
590 llvm::Value *StoreSizeVal = CGF.CGM.getSize(numChars: StoreSize);
591 CGF.Builder.CreateMemCpy(
592 Dest: CGF.Builder.CreateConstInBoundsByteGEP(Addr: DestPtr, Offset: StoreOffset),
593 Src: CGF.Builder.CreateConstInBoundsByteGEP(Addr: SrcPtr, Offset: StoreOffset),
594 Size: StoreSizeVal);
595 }
596
597 // Otherwise, just memset the whole thing to zero. This is legal
598 // because in LLVM, all default initializers (other than the ones we just
599 // handled above) are guaranteed to have a bit pattern of all zeros.
600 } else {
601 for (std::pair<CharUnits, CharUnits> Store : Stores) {
602 CharUnits StoreOffset = Store.first;
603 CharUnits StoreSize = Store.second;
604 llvm::Value *StoreSizeVal = CGF.CGM.getSize(numChars: StoreSize);
605 CGF.Builder.CreateMemSet(
606 Dest: CGF.Builder.CreateConstInBoundsByteGEP(Addr: DestPtr, Offset: StoreOffset),
607 Value: CGF.Builder.getInt8(C: 0), Size: StoreSizeVal);
608 }
609 }
610}
611
612void CodeGenFunction::EmitCXXConstructExpr(const CXXConstructExpr *E,
613 AggValueSlot Dest) {
614 assert(!Dest.isIgnored() && "Must have a destination!");
615 const CXXConstructorDecl *CD = E->getConstructor();
616
617 // If we require zero initialization before (or instead of) calling the
618 // constructor, as can be the case with a non-user-provided default
619 // constructor, emit the zero initialization now, unless destination is
620 // already zeroed.
621 if (E->requiresZeroInitialization() && !Dest.isZeroed()) {
622 switch (E->getConstructionKind()) {
623 case CXXConstructionKind::Delegating:
624 case CXXConstructionKind::Complete:
625 EmitNullInitialization(DestPtr: Dest.getAddress(), Ty: E->getType());
626 break;
627 case CXXConstructionKind::VirtualBase:
628 case CXXConstructionKind::NonVirtualBase:
629 EmitNullBaseClassInitialization(CGF&: *this, DestPtr: Dest.getAddress(),
630 Base: CD->getParent());
631 break;
632 }
633 }
634
635 // If this is a call to a trivial default constructor, do nothing.
636 if (CD->isTrivial() && CD->isDefaultConstructor())
637 return;
638
639 // Elide the constructor if we're constructing from a temporary.
640 if (getLangOpts().ElideConstructors && E->isElidable()) {
641 // FIXME: This only handles the simplest case, where the source object
642 // is passed directly as the first argument to the constructor.
643 // This should also handle stepping though implicit casts and
644 // conversion sequences which involve two steps, with a
645 // conversion operator followed by a converting constructor.
646 const Expr *SrcObj = E->getArg(Arg: 0);
647 assert(SrcObj->isTemporaryObject(getContext(), CD->getParent()));
648 assert(
649 getContext().hasSameUnqualifiedType(E->getType(), SrcObj->getType()));
650 EmitAggExpr(E: SrcObj, AS: Dest);
651 return;
652 }
653
654 if (const ArrayType *arrayType = getContext().getAsArrayType(T: E->getType())) {
655 EmitCXXAggrConstructorCall(D: CD, ArrayTy: arrayType, ArrayPtr: Dest.getAddress(), E,
656 NewPointerIsChecked: Dest.isSanitizerChecked());
657 } else {
658 CXXCtorType Type = Ctor_Complete;
659 bool ForVirtualBase = false;
660 bool Delegating = false;
661
662 switch (E->getConstructionKind()) {
663 case CXXConstructionKind::Delegating:
664 // We should be emitting a constructor; GlobalDecl will assert this
665 Type = CurGD.getCtorType();
666 Delegating = true;
667 break;
668
669 case CXXConstructionKind::Complete:
670 Type = Ctor_Complete;
671 break;
672
673 case CXXConstructionKind::VirtualBase:
674 ForVirtualBase = true;
675 [[fallthrough]];
676
677 case CXXConstructionKind::NonVirtualBase:
678 Type = Ctor_Base;
679 }
680
681 // Call the constructor.
682 EmitCXXConstructorCall(D: CD, Type, ForVirtualBase, Delegating, ThisAVS: Dest, E);
683 }
684}
685
686void CodeGenFunction::EmitSynthesizedCXXCopyCtor(Address Dest, Address Src,
687 const Expr *Exp) {
688 if (const ExprWithCleanups *E = dyn_cast<ExprWithCleanups>(Val: Exp))
689 Exp = E->getSubExpr();
690 assert(isa<CXXConstructExpr>(Exp) &&
691 "EmitSynthesizedCXXCopyCtor - unknown copy ctor expr");
692 const CXXConstructExpr *E = cast<CXXConstructExpr>(Val: Exp);
693 const CXXConstructorDecl *CD = E->getConstructor();
694 RunCleanupsScope Scope(*this);
695
696 // If we require zero initialization before (or instead of) calling the
697 // constructor, as can be the case with a non-user-provided default
698 // constructor, emit the zero initialization now.
699 // FIXME. Do I still need this for a copy ctor synthesis?
700 if (E->requiresZeroInitialization())
701 EmitNullInitialization(DestPtr: Dest, Ty: E->getType());
702
703 assert(!getContext().getAsConstantArrayType(E->getType()) &&
704 "EmitSynthesizedCXXCopyCtor - Copied-in Array");
705 EmitSynthesizedCXXCopyCtorCall(D: CD, This: Dest, Src, E);
706}
707
708static CharUnits CalculateCookiePadding(CodeGenFunction &CGF,
709 const CXXNewExpr *E) {
710 if (!E->isArray())
711 return CharUnits::Zero();
712
713 // No cookie is required if the operator new[] being used is the
714 // reserved placement operator new[].
715 if (E->getOperatorNew()->isReservedGlobalPlacementOperator())
716 return CharUnits::Zero();
717
718 return CGF.CGM.getCXXABI().GetArrayCookieSize(expr: E);
719}
720
721static llvm::Value *EmitCXXNewAllocSize(CodeGenFunction &CGF,
722 const CXXNewExpr *e,
723 unsigned minElements,
724 llvm::Value *&numElements,
725 llvm::Value *&sizeWithoutCookie) {
726 QualType type = e->getAllocatedType();
727
728 if (!e->isArray()) {
729 CharUnits typeSize = CGF.getContext().getTypeSizeInChars(T: type);
730 sizeWithoutCookie =
731 llvm::ConstantInt::get(Ty: CGF.SizeTy, V: typeSize.getQuantity());
732 return sizeWithoutCookie;
733 }
734
735 // The width of size_t.
736 unsigned sizeWidth = CGF.SizeTy->getBitWidth();
737
738 // Figure out the cookie size.
739 llvm::APInt cookieSize(sizeWidth,
740 CalculateCookiePadding(CGF, E: e).getQuantity());
741
742 // Emit the array size expression.
743 // We multiply the size of all dimensions for NumElements.
744 // e.g for 'int[2][3]', ElemType is 'int' and NumElements is 6.
745 numElements = ConstantEmitter(CGF).tryEmitAbstract(
746 E: *e->getArraySize(), T: (*e->getArraySize())->getType());
747 if (!numElements)
748 numElements = CGF.EmitScalarExpr(E: *e->getArraySize());
749 assert(isa<llvm::IntegerType>(numElements->getType()));
750
751 // The number of elements can be have an arbitrary integer type;
752 // essentially, we need to multiply it by a constant factor, add a
753 // cookie size, and verify that the result is representable as a
754 // size_t. That's just a gloss, though, and it's wrong in one
755 // important way: if the count is negative, it's an error even if
756 // the cookie size would bring the total size >= 0.
757 bool isSigned =
758 (*e->getArraySize())->getType()->isSignedIntegerOrEnumerationType();
759 llvm::IntegerType *numElementsType =
760 cast<llvm::IntegerType>(Val: numElements->getType());
761 unsigned numElementsWidth = numElementsType->getBitWidth();
762
763 // Compute the constant factor.
764 llvm::APInt arraySizeMultiplier(sizeWidth, 1);
765 while (const ConstantArrayType *CAT =
766 CGF.getContext().getAsConstantArrayType(T: type)) {
767 type = CAT->getElementType();
768 arraySizeMultiplier *= CAT->getSize();
769 }
770
771 CharUnits typeSize = CGF.getContext().getTypeSizeInChars(T: type);
772 llvm::APInt typeSizeMultiplier(sizeWidth, typeSize.getQuantity());
773 typeSizeMultiplier *= arraySizeMultiplier;
774
775 // This will be a size_t.
776 llvm::Value *size;
777
778 // If someone is doing 'new int[42]' there is no need to do a dynamic check.
779 // Don't bloat the -O0 code.
780 if (llvm::ConstantInt *numElementsC =
781 dyn_cast<llvm::ConstantInt>(Val: numElements)) {
782 const llvm::APInt &count = numElementsC->getValue();
783
784 bool hasAnyOverflow = false;
785
786 // If 'count' was a negative number, it's an overflow.
787 if (isSigned && count.isNegative())
788 hasAnyOverflow = true;
789
790 // We want to do all this arithmetic in size_t. If numElements is
791 // wider than that, check whether it's already too big, and if so,
792 // overflow.
793 else if (numElementsWidth > sizeWidth &&
794 numElementsWidth - sizeWidth > count.countl_zero())
795 hasAnyOverflow = true;
796
797 // Okay, compute a count at the right width.
798 llvm::APInt adjustedCount = count.zextOrTrunc(width: sizeWidth);
799
800 // If there is a brace-initializer, we cannot allocate fewer elements than
801 // there are initializers. If we do, that's treated like an overflow.
802 if (adjustedCount.ult(RHS: minElements))
803 hasAnyOverflow = true;
804
805 // Scale numElements by that. This might overflow, but we don't
806 // care because it only overflows if allocationSize does, too, and
807 // if that overflows then we shouldn't use this.
808 numElements =
809 llvm::ConstantInt::get(Ty: CGF.SizeTy, V: adjustedCount * arraySizeMultiplier);
810
811 // Compute the size before cookie, and track whether it overflowed.
812 bool overflow;
813 llvm::APInt allocationSize =
814 adjustedCount.umul_ov(RHS: typeSizeMultiplier, Overflow&: overflow);
815 hasAnyOverflow |= overflow;
816
817 // Add in the cookie, and check whether it's overflowed.
818 if (cookieSize != 0) {
819 // Save the current size without a cookie. This shouldn't be
820 // used if there was overflow.
821 sizeWithoutCookie = llvm::ConstantInt::get(Ty: CGF.SizeTy, V: allocationSize);
822
823 allocationSize = allocationSize.uadd_ov(RHS: cookieSize, Overflow&: overflow);
824 hasAnyOverflow |= overflow;
825 }
826
827 // On overflow, produce a -1 so operator new will fail.
828 if (hasAnyOverflow) {
829 size = llvm::Constant::getAllOnesValue(Ty: CGF.SizeTy);
830 } else {
831 size = llvm::ConstantInt::get(Ty: CGF.SizeTy, V: allocationSize);
832 }
833
834 // Otherwise, we might need to use the overflow intrinsics.
835 } else {
836 // There are up to five conditions we need to test for:
837 // 1) if isSigned, we need to check whether numElements is negative;
838 // 2) if numElementsWidth > sizeWidth, we need to check whether
839 // numElements is larger than something representable in size_t;
840 // 3) if minElements > 0, we need to check whether numElements is smaller
841 // than that.
842 // 4) we need to compute
843 // sizeWithoutCookie := numElements * typeSizeMultiplier
844 // and check whether it overflows; and
845 // 5) if we need a cookie, we need to compute
846 // size := sizeWithoutCookie + cookieSize
847 // and check whether it overflows.
848
849 llvm::Value *hasOverflow = nullptr;
850
851 // If numElementsWidth > sizeWidth, then one way or another, we're
852 // going to have to do a comparison for (2), and this happens to
853 // take care of (1), too.
854 if (numElementsWidth > sizeWidth) {
855 llvm::APInt threshold =
856 llvm::APInt::getOneBitSet(numBits: numElementsWidth, BitNo: sizeWidth);
857
858 llvm::Value *thresholdV =
859 llvm::ConstantInt::get(Ty: numElementsType, V: threshold);
860
861 hasOverflow = CGF.Builder.CreateICmpUGE(LHS: numElements, RHS: thresholdV);
862 numElements = CGF.Builder.CreateTrunc(V: numElements, DestTy: CGF.SizeTy);
863
864 // Otherwise, if we're signed, we want to sext up to size_t.
865 } else if (isSigned) {
866 if (numElementsWidth < sizeWidth)
867 numElements = CGF.Builder.CreateSExt(V: numElements, DestTy: CGF.SizeTy);
868
869 // If there's a non-1 type size multiplier, then we can do the
870 // signedness check at the same time as we do the multiply
871 // because a negative number times anything will cause an
872 // unsigned overflow. Otherwise, we have to do it here. But at least
873 // in this case, we can subsume the >= minElements check.
874 if (typeSizeMultiplier == 1)
875 hasOverflow = CGF.Builder.CreateICmpSLT(
876 LHS: numElements, RHS: llvm::ConstantInt::get(Ty: CGF.SizeTy, V: minElements));
877
878 // Otherwise, zext up to size_t if necessary.
879 } else if (numElementsWidth < sizeWidth) {
880 numElements = CGF.Builder.CreateZExt(V: numElements, DestTy: CGF.SizeTy);
881 }
882
883 assert(numElements->getType() == CGF.SizeTy);
884
885 if (minElements) {
886 // Don't allow allocation of fewer elements than we have initializers.
887 if (!hasOverflow) {
888 hasOverflow = CGF.Builder.CreateICmpULT(
889 LHS: numElements, RHS: llvm::ConstantInt::get(Ty: CGF.SizeTy, V: minElements));
890 } else if (numElementsWidth > sizeWidth) {
891 // The other existing overflow subsumes this check.
892 // We do an unsigned comparison, since any signed value < -1 is
893 // taken care of either above or below.
894 hasOverflow = CGF.Builder.CreateOr(
895 LHS: hasOverflow,
896 RHS: CGF.Builder.CreateICmpULT(
897 LHS: numElements, RHS: llvm::ConstantInt::get(Ty: CGF.SizeTy, V: minElements)));
898 }
899 }
900
901 size = numElements;
902
903 // Multiply by the type size if necessary. This multiplier
904 // includes all the factors for nested arrays.
905 //
906 // This step also causes numElements to be scaled up by the
907 // nested-array factor if necessary. Overflow on this computation
908 // can be ignored because the result shouldn't be used if
909 // allocation fails.
910 if (typeSizeMultiplier != 1) {
911 llvm::Function *umul_with_overflow =
912 CGF.CGM.getIntrinsic(IID: llvm::Intrinsic::umul_with_overflow, Tys: CGF.SizeTy);
913
914 llvm::Value *tsmV =
915 llvm::ConstantInt::get(Ty: CGF.SizeTy, V: typeSizeMultiplier);
916 llvm::Value *result =
917 CGF.Builder.CreateCall(Callee: umul_with_overflow, Args: {size, tsmV});
918
919 llvm::Value *overflowed = CGF.Builder.CreateExtractValue(Agg: result, Idxs: 1);
920 if (hasOverflow)
921 hasOverflow = CGF.Builder.CreateOr(LHS: hasOverflow, RHS: overflowed);
922 else
923 hasOverflow = overflowed;
924
925 size = CGF.Builder.CreateExtractValue(Agg: result, Idxs: 0);
926
927 // Also scale up numElements by the array size multiplier.
928 if (arraySizeMultiplier != 1) {
929 // If the base element type size is 1, then we can re-use the
930 // multiply we just did.
931 if (typeSize.isOne()) {
932 assert(arraySizeMultiplier == typeSizeMultiplier);
933 numElements = size;
934
935 // Otherwise we need a separate multiply.
936 } else {
937 llvm::Value *asmV =
938 llvm::ConstantInt::get(Ty: CGF.SizeTy, V: arraySizeMultiplier);
939 numElements = CGF.Builder.CreateMul(LHS: numElements, RHS: asmV);
940 }
941 }
942 } else {
943 // numElements doesn't need to be scaled.
944 assert(arraySizeMultiplier == 1);
945 }
946
947 // Add in the cookie size if necessary.
948 if (cookieSize != 0) {
949 sizeWithoutCookie = size;
950
951 llvm::Function *uadd_with_overflow =
952 CGF.CGM.getIntrinsic(IID: llvm::Intrinsic::uadd_with_overflow, Tys: CGF.SizeTy);
953
954 llvm::Value *cookieSizeV = llvm::ConstantInt::get(Ty: CGF.SizeTy, V: cookieSize);
955 llvm::Value *result =
956 CGF.Builder.CreateCall(Callee: uadd_with_overflow, Args: {size, cookieSizeV});
957
958 llvm::Value *overflowed = CGF.Builder.CreateExtractValue(Agg: result, Idxs: 1);
959 if (hasOverflow)
960 hasOverflow = CGF.Builder.CreateOr(LHS: hasOverflow, RHS: overflowed);
961 else
962 hasOverflow = overflowed;
963
964 size = CGF.Builder.CreateExtractValue(Agg: result, Idxs: 0);
965 }
966
967 // If we had any possibility of dynamic overflow, make a select to
968 // overwrite 'size' with an all-ones value, which should cause
969 // operator new to throw.
970 if (hasOverflow)
971 size = CGF.Builder.CreateSelect(
972 C: hasOverflow, True: llvm::Constant::getAllOnesValue(Ty: CGF.SizeTy), False: size);
973 }
974
975 if (cookieSize == 0)
976 sizeWithoutCookie = size;
977 else
978 assert(sizeWithoutCookie && "didn't set sizeWithoutCookie?");
979
980 return size;
981}
982
983static void StoreAnyExprIntoOneUnit(CodeGenFunction &CGF, const Expr *Init,
984 QualType AllocType, Address NewPtr,
985 AggValueSlot::Overlap_t MayOverlap) {
986 // FIXME: Refactor with EmitExprAsInit.
987 switch (CGF.getEvaluationKind(T: AllocType)) {
988 case TEK_Scalar:
989 CGF.EmitScalarInit(init: Init, D: nullptr, lvalue: CGF.MakeAddrLValue(Addr: NewPtr, T: AllocType),
990 capturedByInit: false);
991 return;
992 case TEK_Complex:
993 CGF.EmitComplexExprIntoLValue(E: Init, dest: CGF.MakeAddrLValue(Addr: NewPtr, T: AllocType),
994 /*isInit*/ true);
995 return;
996 case TEK_Aggregate: {
997 AggValueSlot Slot = AggValueSlot::forAddr(
998 addr: NewPtr, quals: AllocType.getQualifiers(), isDestructed: AggValueSlot::IsDestructed,
999 needsGC: AggValueSlot::DoesNotNeedGCBarriers, isAliased: AggValueSlot::IsNotAliased,
1000 mayOverlap: MayOverlap, isZeroed: AggValueSlot::IsNotZeroed,
1001 isChecked: AggValueSlot::IsSanitizerChecked);
1002 CGF.EmitAggExpr(E: Init, AS: Slot);
1003 return;
1004 }
1005 }
1006 llvm_unreachable("bad evaluation kind");
1007}
1008
1009void CodeGenFunction::EmitNewArrayInitializer(
1010 const CXXNewExpr *E, QualType ElementType, llvm::Type *ElementTy,
1011 Address BeginPtr, llvm::Value *NumElements,
1012 llvm::Value *AllocSizeWithoutCookie) {
1013 // If we have a type with trivial initialization and no initializer,
1014 // there's nothing to do.
1015 if (!E->hasInitializer())
1016 return;
1017
1018 Address CurPtr = BeginPtr;
1019
1020 unsigned InitListElements = 0;
1021
1022 const Expr *Init = E->getInitializer();
1023 Address EndOfInit = Address::invalid();
1024 QualType::DestructionKind DtorKind = ElementType.isDestructedType();
1025 CleanupDeactivationScope deactivation(*this);
1026 bool pushedCleanup = false;
1027
1028 CharUnits ElementSize = getContext().getTypeSizeInChars(T: ElementType);
1029 CharUnits ElementAlign =
1030 BeginPtr.getAlignment().alignmentOfArrayElement(elementSize: ElementSize);
1031
1032 // Attempt to perform zero-initialization using memset.
1033 auto TryMemsetInitialization = [&]() -> bool {
1034 // FIXME: If the type is a pointer-to-data-member under the Itanium ABI,
1035 // we can initialize with a memset to -1.
1036 if (!CGM.getTypes().isZeroInitializable(T: ElementType))
1037 return false;
1038
1039 // Optimization: since zero initialization will just set the memory
1040 // to all zeroes, generate a single memset to do it in one shot.
1041
1042 // Subtract out the size of any elements we've already initialized.
1043 auto *RemainingSize = AllocSizeWithoutCookie;
1044 if (InitListElements) {
1045 // We know this can't overflow; we check this when doing the allocation.
1046 auto *InitializedSize = llvm::ConstantInt::get(
1047 Ty: RemainingSize->getType(),
1048 V: getContext().getTypeSizeInChars(T: ElementType).getQuantity() *
1049 InitListElements);
1050 RemainingSize = Builder.CreateSub(LHS: RemainingSize, RHS: InitializedSize);
1051 }
1052
1053 // Create the memset.
1054 Builder.CreateMemSet(Dest: CurPtr, Value: Builder.getInt8(C: 0), Size: RemainingSize, IsVolatile: false);
1055 return true;
1056 };
1057
1058 const InitListExpr *ILE = dyn_cast<InitListExpr>(Val: Init);
1059 const CXXParenListInitExpr *CPLIE = nullptr;
1060 const StringLiteral *SL = nullptr;
1061 const ObjCEncodeExpr *OCEE = nullptr;
1062 const Expr *IgnoreParen = nullptr;
1063 if (!ILE) {
1064 IgnoreParen = Init->IgnoreParenImpCasts();
1065 CPLIE = dyn_cast<CXXParenListInitExpr>(Val: IgnoreParen);
1066 SL = dyn_cast<StringLiteral>(Val: IgnoreParen);
1067 OCEE = dyn_cast<ObjCEncodeExpr>(Val: IgnoreParen);
1068 }
1069
1070 // If the initializer is an initializer list, first do the explicit elements.
1071 if (ILE || CPLIE || SL || OCEE) {
1072 // Initializing from a (braced) string literal is a special case; the init
1073 // list element does not initialize a (single) array element.
1074 if ((ILE && ILE->isStringLiteralInit()) || SL || OCEE) {
1075 if (!ILE)
1076 Init = IgnoreParen;
1077 // Initialize the initial portion of length equal to that of the string
1078 // literal. The allocation must be for at least this much; we emitted a
1079 // check for that earlier.
1080 AggValueSlot Slot = AggValueSlot::forAddr(
1081 addr: CurPtr, quals: ElementType.getQualifiers(), isDestructed: AggValueSlot::IsDestructed,
1082 needsGC: AggValueSlot::DoesNotNeedGCBarriers, isAliased: AggValueSlot::IsNotAliased,
1083 mayOverlap: AggValueSlot::DoesNotOverlap, isZeroed: AggValueSlot::IsNotZeroed,
1084 isChecked: AggValueSlot::IsSanitizerChecked);
1085 EmitAggExpr(E: ILE ? ILE->getInit(Init: 0) : Init, AS: Slot);
1086
1087 // Move past these elements.
1088 InitListElements =
1089 cast<ConstantArrayType>(Val: Init->getType()->getAsArrayTypeUnsafe())
1090 ->getZExtSize();
1091 CurPtr = Builder.CreateConstInBoundsGEP(Addr: CurPtr, Index: InitListElements,
1092 Name: "string.init.end");
1093
1094 // Zero out the rest, if any remain.
1095 llvm::ConstantInt *ConstNum = dyn_cast<llvm::ConstantInt>(Val: NumElements);
1096 if (!ConstNum || !ConstNum->equalsInt(V: InitListElements)) {
1097 bool OK = TryMemsetInitialization();
1098 (void)OK;
1099 assert(OK && "couldn't memset character type?");
1100 }
1101 return;
1102 }
1103
1104 ArrayRef<const Expr *> InitExprs =
1105 ILE ? ILE->inits() : CPLIE->getInitExprs();
1106 InitListElements = InitExprs.size();
1107
1108 // If this is a multi-dimensional array new, we will initialize multiple
1109 // elements with each init list element.
1110 QualType AllocType = E->getAllocatedType();
1111 if (const ConstantArrayType *CAT = dyn_cast_or_null<ConstantArrayType>(
1112 Val: AllocType->getAsArrayTypeUnsafe())) {
1113 ElementTy = ConvertTypeForMem(T: AllocType);
1114 CurPtr = CurPtr.withElementType(ElemTy: ElementTy);
1115 InitListElements *= getContext().getConstantArrayElementCount(CA: CAT);
1116 }
1117
1118 // Enter a partial-destruction Cleanup if necessary.
1119 if (DtorKind) {
1120 AllocaTrackerRAII AllocaTracker(*this);
1121 // In principle we could tell the Cleanup where we are more
1122 // directly, but the control flow can get so varied here that it
1123 // would actually be quite complex. Therefore we go through an
1124 // alloca.
1125 llvm::Instruction *DominatingIP =
1126 Builder.CreateFlagLoad(Addr: llvm::ConstantInt::getNullValue(Ty: Int8PtrTy));
1127 EndOfInit = CreateTempAlloca(Ty: BeginPtr.getType(), align: getPointerAlign(),
1128 Name: "array.init.end");
1129 pushIrregularPartialArrayCleanup(arrayBegin: BeginPtr.emitRawPointer(CGF&: *this),
1130 arrayEndPointer: EndOfInit, elementType: ElementType, elementAlignment: ElementAlign,
1131 destroyer: getDestroyer(destructionKind: DtorKind));
1132 cast<EHCleanupScope>(Val&: *EHStack.find(sp: EHStack.stable_begin()))
1133 .AddAuxAllocas(Allocas: AllocaTracker.Take());
1134 DeferredDeactivationCleanupStack.push_back(
1135 Elt: {.Cleanup: EHStack.stable_begin(), .DominatingIP: DominatingIP});
1136 pushedCleanup = true;
1137 }
1138
1139 CharUnits StartAlign = CurPtr.getAlignment();
1140 unsigned i = 0;
1141 for (const Expr *IE : InitExprs) {
1142 // Tell the cleanup that it needs to destroy up to this
1143 // element. TODO: some of these stores can be trivially
1144 // observed to be unnecessary.
1145 if (EndOfInit.isValid()) {
1146 Builder.CreateStore(Val: CurPtr.emitRawPointer(CGF&: *this), Addr: EndOfInit);
1147 }
1148 // FIXME: If the last initializer is an incomplete initializer list for
1149 // an array, and we have an array filler, we can fold together the two
1150 // initialization loops.
1151 StoreAnyExprIntoOneUnit(CGF&: *this, Init: IE, AllocType: IE->getType(), NewPtr: CurPtr,
1152 MayOverlap: AggValueSlot::DoesNotOverlap);
1153 CurPtr = Address(Builder.CreateInBoundsGEP(Ty: CurPtr.getElementType(),
1154 Ptr: CurPtr.emitRawPointer(CGF&: *this),
1155 IdxList: Builder.getSize(N: 1),
1156 Name: "array.exp.next"),
1157 CurPtr.getElementType(),
1158 StartAlign.alignmentAtOffset(offset: (++i) * ElementSize));
1159 }
1160
1161 // The remaining elements are filled with the array filler expression.
1162 Init = ILE ? ILE->getArrayFiller() : CPLIE->getArrayFiller();
1163
1164 // Extract the initializer for the individual array elements by pulling
1165 // out the array filler from all the nested initializer lists. This avoids
1166 // generating a nested loop for the initialization.
1167 while (Init && Init->getType()->isConstantArrayType()) {
1168 auto *SubILE = dyn_cast<InitListExpr>(Val: Init);
1169 if (!SubILE)
1170 break;
1171 assert(SubILE->getNumInits() == 0 && "explicit inits in array filler?");
1172 Init = SubILE->getArrayFiller();
1173 }
1174
1175 // Switch back to initializing one base element at a time.
1176 CurPtr = CurPtr.withElementType(ElemTy: BeginPtr.getElementType());
1177 }
1178
1179 // If all elements have already been initialized, skip any further
1180 // initialization.
1181 llvm::ConstantInt *ConstNum = dyn_cast<llvm::ConstantInt>(Val: NumElements);
1182 if (ConstNum && ConstNum->getZExtValue() <= InitListElements) {
1183 return;
1184 }
1185
1186 assert(Init && "have trailing elements to initialize but no initializer");
1187
1188 // If this is a constructor call, try to optimize it out, and failing that
1189 // emit a single loop to initialize all remaining elements.
1190 if (const CXXConstructExpr *CCE = dyn_cast<CXXConstructExpr>(Val: Init)) {
1191 CXXConstructorDecl *Ctor = CCE->getConstructor();
1192 if (Ctor->isTrivial()) {
1193 // If new expression did not specify value-initialization, then there
1194 // is no initialization.
1195 if (!CCE->requiresZeroInitialization() || Ctor->getParent()->isEmpty())
1196 return;
1197
1198 if (TryMemsetInitialization())
1199 return;
1200 }
1201
1202 // Store the new Cleanup position for irregular Cleanups.
1203 //
1204 // FIXME: Share this cleanup with the constructor call emission rather than
1205 // having it create a cleanup of its own.
1206 if (EndOfInit.isValid())
1207 Builder.CreateStore(Val: CurPtr.emitRawPointer(CGF&: *this), Addr: EndOfInit);
1208
1209 // Emit a constructor call loop to initialize the remaining elements.
1210 if (InitListElements)
1211 NumElements = Builder.CreateSub(
1212 LHS: NumElements,
1213 RHS: llvm::ConstantInt::get(Ty: NumElements->getType(), V: InitListElements));
1214 EmitCXXAggrConstructorCall(D: Ctor, NumElements, ArrayPtr: CurPtr, E: CCE,
1215 /*NewPointerIsChecked*/ true,
1216 ZeroInitialization: CCE->requiresZeroInitialization());
1217 if (getContext().getTargetInfo().emitVectorDeletingDtors(
1218 getContext().getLangOpts())) {
1219 CXXDestructorDecl *Dtor = Ctor->getParent()->getDestructor();
1220 if (Dtor && Dtor->isVirtual())
1221 CGM.requireVectorDestructorDefinition(RD: Ctor->getParent());
1222 }
1223 return;
1224 }
1225
1226 // If this is value-initialization, we can usually use memset.
1227 ImplicitValueInitExpr IVIE(ElementType);
1228 if (isa<ImplicitValueInitExpr>(Val: Init)) {
1229 if (TryMemsetInitialization())
1230 return;
1231
1232 // Switch to an ImplicitValueInitExpr for the element type. This handles
1233 // only one case: multidimensional array new of pointers to members. In
1234 // all other cases, we already have an initializer for the array element.
1235 Init = &IVIE;
1236 }
1237
1238 // At this point we should have found an initializer for the individual
1239 // elements of the array.
1240 assert(getContext().hasSameUnqualifiedType(ElementType, Init->getType()) &&
1241 "got wrong type of element to initialize");
1242
1243 // If we have an empty initializer list, we can usually use memset.
1244 if (auto *ILE = dyn_cast<InitListExpr>(Val: Init))
1245 if (ILE->getNumInits() == 0 && TryMemsetInitialization())
1246 return;
1247
1248 // If we have a struct whose every field is value-initialized, we can
1249 // usually use memset.
1250 if (auto *ILE = dyn_cast<InitListExpr>(Val: Init)) {
1251 if (const RecordType *RType =
1252 ILE->getType()->getAsCanonical<RecordType>()) {
1253 if (RType->getDecl()->isStruct()) {
1254 const RecordDecl *RD = RType->getDecl()->getDefinitionOrSelf();
1255 unsigned NumElements = 0;
1256 if (auto *CXXRD = dyn_cast<CXXRecordDecl>(Val: RD))
1257 NumElements = CXXRD->getNumBases();
1258 for (auto *Field : RD->fields())
1259 if (!Field->isUnnamedBitField())
1260 ++NumElements;
1261 // FIXME: Recurse into nested InitListExprs.
1262 if (ILE->getNumInits() == NumElements)
1263 for (unsigned i = 0, e = ILE->getNumInits(); i != e; ++i)
1264 if (!isa<ImplicitValueInitExpr>(Val: ILE->getInit(Init: i)))
1265 --NumElements;
1266 if (ILE->getNumInits() == NumElements && TryMemsetInitialization())
1267 return;
1268 }
1269 }
1270 }
1271
1272 // Create the loop blocks.
1273 llvm::BasicBlock *EntryBB = Builder.GetInsertBlock();
1274 llvm::BasicBlock *LoopBB = createBasicBlock(name: "new.loop");
1275 llvm::BasicBlock *ContBB = createBasicBlock(name: "new.loop.end");
1276
1277 // Find the end of the array, hoisted out of the loop.
1278 llvm::Value *EndPtr = Builder.CreateInBoundsGEP(
1279 Ty: BeginPtr.getElementType(), Ptr: BeginPtr.emitRawPointer(CGF&: *this), IdxList: NumElements,
1280 Name: "array.end");
1281
1282 // If the number of elements isn't constant, we have to now check if there is
1283 // anything left to initialize.
1284 if (!ConstNum) {
1285 llvm::Value *IsEmpty = Builder.CreateICmpEQ(LHS: CurPtr.emitRawPointer(CGF&: *this),
1286 RHS: EndPtr, Name: "array.isempty");
1287 Builder.CreateCondBr(Cond: IsEmpty, True: ContBB, False: LoopBB);
1288 }
1289
1290 // Enter the loop.
1291 EmitBlock(BB: LoopBB);
1292
1293 // Set up the current-element phi.
1294 llvm::PHINode *CurPtrPhi =
1295 Builder.CreatePHI(Ty: CurPtr.getType(), NumReservedValues: 2, Name: "array.cur");
1296 CurPtrPhi->addIncoming(V: CurPtr.emitRawPointer(CGF&: *this), BB: EntryBB);
1297
1298 CurPtr = Address(CurPtrPhi, CurPtr.getElementType(), ElementAlign);
1299
1300 // Store the new Cleanup position for irregular Cleanups.
1301 if (EndOfInit.isValid())
1302 Builder.CreateStore(Val: CurPtr.emitRawPointer(CGF&: *this), Addr: EndOfInit);
1303
1304 // Enter a partial-destruction Cleanup if necessary.
1305 if (!pushedCleanup && needsEHCleanup(kind: DtorKind)) {
1306 llvm::Instruction *DominatingIP =
1307 Builder.CreateFlagLoad(Addr: llvm::ConstantInt::getNullValue(Ty: Int8PtrTy));
1308 pushRegularPartialArrayCleanup(arrayBegin: BeginPtr.emitRawPointer(CGF&: *this),
1309 arrayEnd: CurPtr.emitRawPointer(CGF&: *this), elementType: ElementType,
1310 elementAlignment: ElementAlign, destroyer: getDestroyer(destructionKind: DtorKind));
1311 DeferredDeactivationCleanupStack.push_back(
1312 Elt: {.Cleanup: EHStack.stable_begin(), .DominatingIP: DominatingIP});
1313 }
1314
1315 // Emit the initializer into this element.
1316 StoreAnyExprIntoOneUnit(CGF&: *this, Init, AllocType: Init->getType(), NewPtr: CurPtr,
1317 MayOverlap: AggValueSlot::DoesNotOverlap);
1318
1319 // Leave the Cleanup if we entered one.
1320 deactivation.ForceDeactivate();
1321
1322 // Advance to the next element by adjusting the pointer type as necessary.
1323 llvm::Value *NextPtr = Builder.CreateConstInBoundsGEP1_32(
1324 Ty: ElementTy, Ptr: CurPtr.emitRawPointer(CGF&: *this), Idx0: 1, Name: "array.next");
1325
1326 // Check whether we've gotten to the end of the array and, if so,
1327 // exit the loop.
1328 llvm::Value *IsEnd = Builder.CreateICmpEQ(LHS: NextPtr, RHS: EndPtr, Name: "array.atend");
1329 Builder.CreateCondBr(Cond: IsEnd, True: ContBB, False: LoopBB);
1330 CurPtrPhi->addIncoming(V: NextPtr, BB: Builder.GetInsertBlock());
1331
1332 EmitBlock(BB: ContBB);
1333}
1334
1335static void EmitNewInitializer(CodeGenFunction &CGF, const CXXNewExpr *E,
1336 QualType ElementType, llvm::Type *ElementTy,
1337 Address NewPtr, llvm::Value *NumElements,
1338 llvm::Value *AllocSizeWithoutCookie) {
1339 ApplyDebugLocation DL(CGF, E);
1340 if (E->isArray())
1341 CGF.EmitNewArrayInitializer(E, ElementType, ElementTy, BeginPtr: NewPtr, NumElements,
1342 AllocSizeWithoutCookie);
1343 else if (const Expr *Init = E->getInitializer())
1344 StoreAnyExprIntoOneUnit(CGF, Init, AllocType: E->getAllocatedType(), NewPtr,
1345 MayOverlap: AggValueSlot::DoesNotOverlap);
1346}
1347
1348/// Emit a call to an operator new or operator delete function, as implicitly
1349/// created by new-expressions and delete-expressions.
1350static RValue EmitNewDeleteCall(CodeGenFunction &CGF,
1351 const FunctionDecl *CalleeDecl,
1352 const FunctionProtoType *CalleeType,
1353 const CallArgList &Args,
1354 llvm::Constant *CalleeOverride = nullptr) {
1355 llvm::CallBase *CallOrInvoke;
1356 llvm::Constant *CalleePtr =
1357 CalleeOverride ? CalleeOverride : CGF.CGM.GetAddrOfFunction(GD: CalleeDecl);
1358 CGCallee Callee = CGCallee::forDirect(functionPtr: CalleePtr, abstractInfo: GlobalDecl(CalleeDecl));
1359 RValue RV = CGF.EmitCall(
1360 CallInfo: CGF.CGM.getTypes().arrangeFreeFunctionCall(
1361 Args, Ty: CalleeType, /*ChainCall=*/false, ABIInfoFD: CGF.getCurrentFunctionDecl()),
1362 Callee, ReturnValue: ReturnValueSlot(), Args, CallOrInvoke: &CallOrInvoke);
1363
1364 /// C++1y [expr.new]p10:
1365 /// [In a new-expression,] an implementation is allowed to omit a call
1366 /// to a replaceable global allocation function.
1367 ///
1368 /// We model such elidable calls with the 'builtin' attribute.
1369 llvm::Function *Fn = dyn_cast<llvm::Function>(Val: CalleePtr);
1370 if (CalleeDecl->isReplaceableGlobalAllocationFunction() && Fn &&
1371 Fn->hasFnAttribute(Kind: llvm::Attribute::NoBuiltin)) {
1372 CallOrInvoke->addFnAttr(Kind: llvm::Attribute::Builtin);
1373 }
1374
1375 return RV;
1376}
1377
1378RValue CodeGenFunction::EmitBuiltinNewDeleteCall(const FunctionProtoType *Type,
1379 const CallExpr *TheCall,
1380 bool IsDelete) {
1381 CallArgList Args;
1382 EmitCallArgs(Args, Prototype: Type, ArgRange: TheCall->arguments());
1383 // Find the allocation or deallocation function that we're calling.
1384 ASTContext &Ctx = getContext();
1385 DeclarationName Name =
1386 Ctx.DeclarationNames.getCXXOperatorName(Op: IsDelete ? OO_Delete : OO_New);
1387
1388 for (auto *Decl : Ctx.getTranslationUnitDecl()->lookup(Name))
1389 if (auto *FD = dyn_cast<FunctionDecl>(Val: Decl))
1390 if (Ctx.hasSameType(T1: FD->getType(), T2: QualType(Type, 0))) {
1391 RValue RV = EmitNewDeleteCall(CGF&: *this, CalleeDecl: FD, CalleeType: Type, Args);
1392 if (auto *CB = dyn_cast_if_present<llvm::CallBase>(Val: RV.getScalarVal())) {
1393 if (SanOpts.has(K: SanitizerKind::AllocToken)) {
1394 // Set !alloc_token metadata.
1395 EmitAllocToken(CB, E: TheCall);
1396 }
1397 }
1398 return RV;
1399 }
1400 llvm_unreachable("predeclared global operator new/delete is missing");
1401}
1402
1403namespace {
1404/// A cleanup to call the given 'operator delete' function upon abnormal
1405/// exit from a new expression. Templated on a traits type that deals with
1406/// ensuring that the arguments dominate the cleanup if necessary.
1407template <typename Traits>
1408class CallDeleteDuringNew final : public EHScopeStack::Cleanup {
1409 /// Type used to hold llvm::Value*s.
1410 typedef typename Traits::ValueTy ValueTy;
1411 /// Type used to hold RValues.
1412 typedef typename Traits::RValueTy RValueTy;
1413 struct PlacementArg {
1414 RValueTy ArgValue;
1415 QualType ArgType;
1416 };
1417
1418 unsigned NumPlacementArgs : 30;
1419 LLVM_PREFERRED_TYPE(AlignedAllocationMode)
1420 unsigned PassAlignmentToPlacementDelete : 1;
1421 const FunctionDecl *OperatorDelete;
1422 RValueTy TypeIdentity;
1423 ValueTy Ptr;
1424 ValueTy AllocSize;
1425 CharUnits AllocAlign;
1426
1427 PlacementArg *getPlacementArgs() {
1428 return reinterpret_cast<PlacementArg *>(this + 1);
1429 }
1430
1431public:
1432 static size_t getExtraSize(size_t NumPlacementArgs) {
1433 return NumPlacementArgs * sizeof(PlacementArg);
1434 }
1435
1436 CallDeleteDuringNew(size_t NumPlacementArgs,
1437 const FunctionDecl *OperatorDelete, RValueTy TypeIdentity,
1438 ValueTy Ptr, ValueTy AllocSize,
1439 const ImplicitAllocationParameters &IAP,
1440 CharUnits AllocAlign)
1441 : NumPlacementArgs(NumPlacementArgs),
1442 PassAlignmentToPlacementDelete(isAlignedAllocation(Mode: IAP.PassAlignment)),
1443 OperatorDelete(OperatorDelete), TypeIdentity(TypeIdentity), Ptr(Ptr),
1444 AllocSize(AllocSize), AllocAlign(AllocAlign) {}
1445
1446 void setPlacementArg(unsigned I, RValueTy Arg, QualType Type) {
1447 assert(I < NumPlacementArgs && "index out of range");
1448 getPlacementArgs()[I] = {Arg, Type};
1449 }
1450
1451 void Emit(CodeGenFunction &CGF, Flags flags) override {
1452 const auto *FPT = OperatorDelete->getType()->castAs<FunctionProtoType>();
1453 CallArgList DeleteArgs;
1454 unsigned FirstNonTypeArg = 0;
1455 TypeAwareAllocationMode TypeAwareDeallocation = TypeAwareAllocationMode::No;
1456 if (OperatorDelete->isTypeAwareOperatorNewOrDelete()) {
1457 TypeAwareDeallocation = TypeAwareAllocationMode::Yes;
1458 QualType SpecializedTypeIdentity = FPT->getParamType(i: 0);
1459 ++FirstNonTypeArg;
1460 DeleteArgs.add(rvalue: Traits::get(CGF, TypeIdentity), type: SpecializedTypeIdentity);
1461 }
1462 // The first argument after type-identity parameter (if any) is always
1463 // a void* (or C* for a destroying operator delete for class type C).
1464 DeleteArgs.add(rvalue: Traits::get(CGF, Ptr), type: FPT->getParamType(i: FirstNonTypeArg));
1465
1466 // Figure out what other parameters we should be implicitly passing.
1467 UsualDeleteParams Params;
1468 if (NumPlacementArgs) {
1469 // A placement deallocation function is implicitly passed an alignment
1470 // if the placement allocation function was, but is never passed a size.
1471 Params.Alignment =
1472 alignedAllocationModeFromBool(IsAligned: PassAlignmentToPlacementDelete);
1473 Params.TypeAwareDelete = TypeAwareDeallocation;
1474 Params.Size = isTypeAwareAllocation(Mode: Params.TypeAwareDelete);
1475 } else {
1476 // For a non-placement new-expression, 'operator delete' can take a
1477 // size and/or an alignment if it has the right parameters.
1478 Params = OperatorDelete->getUsualDeleteParams();
1479 }
1480
1481 assert(!Params.DestroyingDelete &&
1482 "should not call destroying delete in a new-expression");
1483
1484 // The second argument can be a std::size_t (for non-placement delete).
1485 if (Params.Size)
1486 DeleteArgs.add(rvalue: Traits::get(CGF, AllocSize),
1487 type: CGF.getContext().getSizeType());
1488
1489 // The next (second or third) argument can be a std::align_val_t, which
1490 // is an enum whose underlying type is std::size_t.
1491 // FIXME: Use the right type as the parameter type. Note that in a call
1492 // to operator delete(size_t, ...), we may not have it available.
1493 if (isAlignedAllocation(Mode: Params.Alignment))
1494 DeleteArgs.add(rvalue: RValue::get(V: llvm::ConstantInt::get(
1495 Ty: CGF.SizeTy, V: AllocAlign.getQuantity())),
1496 type: CGF.getContext().getSizeType());
1497
1498 // Pass the rest of the arguments, which must match exactly.
1499 for (unsigned I = 0; I != NumPlacementArgs; ++I) {
1500 auto Arg = getPlacementArgs()[I];
1501 DeleteArgs.add(rvalue: Traits::get(CGF, Arg.ArgValue), type: Arg.ArgType);
1502 }
1503
1504 // Call 'operator delete'.
1505 EmitNewDeleteCall(CGF, CalleeDecl: OperatorDelete, CalleeType: FPT, Args: DeleteArgs);
1506 }
1507};
1508} // namespace
1509
1510/// Enter a cleanup to call 'operator delete' if the initializer in a
1511/// new-expression throws.
1512static void EnterNewDeleteCleanup(CodeGenFunction &CGF, const CXXNewExpr *E,
1513 RValue TypeIdentity, Address NewPtr,
1514 llvm::Value *AllocSize, CharUnits AllocAlign,
1515 const CallArgList &NewArgs) {
1516 unsigned NumNonPlacementArgs = E->getNumImplicitArgs();
1517
1518 // If we're not inside a conditional branch, then the cleanup will
1519 // dominate and we can do the easier (and more efficient) thing.
1520 if (!CGF.isInConditionalBranch()) {
1521 struct DirectCleanupTraits {
1522 typedef llvm::Value *ValueTy;
1523 typedef RValue RValueTy;
1524 static RValue get(CodeGenFunction &, ValueTy V) { return RValue::get(V); }
1525 static RValue get(CodeGenFunction &, RValueTy V) { return V; }
1526 };
1527
1528 typedef CallDeleteDuringNew<DirectCleanupTraits> DirectCleanup;
1529
1530 DirectCleanup *Cleanup = CGF.EHStack.pushCleanupWithExtra<DirectCleanup>(
1531 Kind: EHCleanup, N: E->getNumPlacementArgs(), A: E->getOperatorDelete(),
1532 A: TypeIdentity, A: NewPtr.emitRawPointer(CGF), A: AllocSize,
1533 A: E->implicitAllocationParameters(), A: AllocAlign);
1534 for (unsigned I = 0, N = E->getNumPlacementArgs(); I != N; ++I) {
1535 auto &Arg = NewArgs[I + NumNonPlacementArgs];
1536 Cleanup->setPlacementArg(I, Arg: Arg.getRValue(CGF), Type: Arg.Ty);
1537 }
1538
1539 return;
1540 }
1541
1542 // Otherwise, we need to save all this stuff.
1543 DominatingValue<RValue>::saved_type SavedNewPtr =
1544 DominatingValue<RValue>::save(CGF, value: RValue::get(Addr: NewPtr, CGF));
1545 DominatingValue<RValue>::saved_type SavedAllocSize =
1546 DominatingValue<RValue>::save(CGF, value: RValue::get(V: AllocSize));
1547 DominatingValue<RValue>::saved_type SavedTypeIdentity =
1548 DominatingValue<RValue>::save(CGF, value: TypeIdentity);
1549 struct ConditionalCleanupTraits {
1550 typedef DominatingValue<RValue>::saved_type ValueTy;
1551 typedef DominatingValue<RValue>::saved_type RValueTy;
1552 static RValue get(CodeGenFunction &CGF, ValueTy V) {
1553 return V.restore(CGF);
1554 }
1555 };
1556 typedef CallDeleteDuringNew<ConditionalCleanupTraits> ConditionalCleanup;
1557
1558 ConditionalCleanup *Cleanup =
1559 CGF.EHStack.pushCleanupWithExtra<ConditionalCleanup>(
1560 Kind: EHCleanup, N: E->getNumPlacementArgs(), A: E->getOperatorDelete(),
1561 A: SavedTypeIdentity, A: SavedNewPtr, A: SavedAllocSize,
1562 A: E->implicitAllocationParameters(), A: AllocAlign);
1563 for (unsigned I = 0, N = E->getNumPlacementArgs(); I != N; ++I) {
1564 auto &Arg = NewArgs[I + NumNonPlacementArgs];
1565 Cleanup->setPlacementArg(
1566 I, Arg: DominatingValue<RValue>::save(CGF, value: Arg.getRValue(CGF)), Type: Arg.Ty);
1567 }
1568
1569 CGF.initFullExprCleanup();
1570}
1571
1572llvm::Value *CodeGenFunction::EmitCXXNewExpr(const CXXNewExpr *E) {
1573 // The element type being allocated.
1574 QualType allocType = getContext().getBaseElementType(QT: E->getAllocatedType());
1575
1576 // 1. Build a call to the allocation function.
1577 FunctionDecl *allocator = E->getOperatorNew();
1578
1579 // If there is a brace-initializer or C++20 parenthesized initializer, cannot
1580 // allocate fewer elements than inits.
1581 unsigned minElements = 0;
1582 unsigned IndexOfAlignArg = 1;
1583 if (E->isArray() && E->hasInitializer()) {
1584 const Expr *Init = E->getInitializer();
1585 const InitListExpr *ILE = dyn_cast<InitListExpr>(Val: Init);
1586 const CXXParenListInitExpr *CPLIE = dyn_cast<CXXParenListInitExpr>(Val: Init);
1587 const Expr *IgnoreParen = Init->IgnoreParenImpCasts();
1588 if ((ILE && ILE->isStringLiteralInit()) ||
1589 isa<StringLiteral>(Val: IgnoreParen) || isa<ObjCEncodeExpr>(Val: IgnoreParen)) {
1590 minElements =
1591 cast<ConstantArrayType>(Val: Init->getType()->getAsArrayTypeUnsafe())
1592 ->getZExtSize();
1593 } else if (ILE || CPLIE) {
1594 minElements = ILE ? ILE->getNumInits() : CPLIE->getInitExprs().size();
1595 }
1596 }
1597
1598 llvm::Value *numElements = nullptr;
1599 llvm::Value *allocSizeWithoutCookie = nullptr;
1600 llvm::Value *allocSize = EmitCXXNewAllocSize(
1601 CGF&: *this, e: E, minElements, numElements, sizeWithoutCookie&: allocSizeWithoutCookie);
1602 CharUnits allocAlign = getContext().getTypeAlignInChars(T: allocType);
1603
1604 // Emit the allocation call. If the allocator is a global placement
1605 // operator, just "inline" it directly.
1606 Address allocation = Address::invalid();
1607 CallArgList allocatorArgs;
1608 RValue TypeIdentityArg;
1609 if (allocator->isReservedGlobalPlacementOperator()) {
1610 assert(E->getNumPlacementArgs() == 1);
1611 const Expr *arg = *E->placement_arguments().begin();
1612
1613 LValueBaseInfo BaseInfo;
1614 allocation = EmitPointerWithAlignment(Addr: arg, BaseInfo: &BaseInfo);
1615
1616 // The pointer expression will, in many cases, be an opaque void*.
1617 // In these cases, discard the computed alignment and use the
1618 // formal alignment of the allocated type.
1619 if (BaseInfo.getAlignmentSource() != AlignmentSource::Decl)
1620 allocation.setAlignment(allocAlign);
1621
1622 // Set up allocatorArgs for the call to operator delete if it's not
1623 // the reserved global operator.
1624 if (E->getOperatorDelete() &&
1625 !E->getOperatorDelete()->isReservedGlobalPlacementOperator()) {
1626 allocatorArgs.add(rvalue: RValue::get(V: allocSize), type: getContext().getSizeType());
1627 allocatorArgs.add(rvalue: RValue::get(Addr: allocation, CGF&: *this), type: arg->getType());
1628 }
1629
1630 } else {
1631 const FunctionProtoType *allocatorType =
1632 allocator->getType()->castAs<FunctionProtoType>();
1633 ImplicitAllocationParameters IAP = E->implicitAllocationParameters();
1634 unsigned ParamsToSkip = 0;
1635 if (isTypeAwareAllocation(Mode: IAP.PassTypeIdentity)) {
1636 QualType SpecializedTypeIdentity = allocatorType->getParamType(i: 0);
1637 CXXScalarValueInitExpr TypeIdentityParam(SpecializedTypeIdentity, nullptr,
1638 SourceLocation());
1639 TypeIdentityArg = EmitAnyExprToTemp(E: &TypeIdentityParam);
1640 allocatorArgs.add(rvalue: TypeIdentityArg, type: SpecializedTypeIdentity);
1641 ++ParamsToSkip;
1642 ++IndexOfAlignArg;
1643 }
1644 // The allocation size is the first argument.
1645 QualType sizeType = getContext().getSizeType();
1646 allocatorArgs.add(rvalue: RValue::get(V: allocSize), type: sizeType);
1647 ++ParamsToSkip;
1648
1649 if (allocSize != allocSizeWithoutCookie) {
1650 CharUnits cookieAlign = getSizeAlign(); // FIXME: Ask the ABI.
1651 allocAlign = std::max(a: allocAlign, b: cookieAlign);
1652 }
1653
1654 // The allocation alignment may be passed as the second argument.
1655 if (isAlignedAllocation(Mode: IAP.PassAlignment)) {
1656 QualType AlignValT = sizeType;
1657 if (allocatorType->getNumParams() > IndexOfAlignArg) {
1658 AlignValT = allocatorType->getParamType(i: IndexOfAlignArg);
1659 assert(getContext().hasSameUnqualifiedType(
1660 AlignValT->castAsEnumDecl()->getIntegerType(), sizeType) &&
1661 "wrong type for alignment parameter");
1662 ++ParamsToSkip;
1663 } else {
1664 // Corner case, passing alignment to 'operator new(size_t, ...)'.
1665 assert(allocator->isVariadic() && "can't pass alignment to allocator");
1666 }
1667 allocatorArgs.add(
1668 rvalue: RValue::get(V: llvm::ConstantInt::get(Ty: SizeTy, V: allocAlign.getQuantity())),
1669 type: AlignValT);
1670 }
1671
1672 // FIXME: Why do we not pass a CalleeDecl here?
1673 EmitCallArgs(Args&: allocatorArgs, Prototype: allocatorType, ArgRange: E->placement_arguments(),
1674 /*AC*/ AbstractCallee(), /*ParamsToSkip*/ ParamsToSkip);
1675
1676 RValue RV =
1677 EmitNewDeleteCall(CGF&: *this, CalleeDecl: allocator, CalleeType: allocatorType, Args: allocatorArgs);
1678
1679 if (auto *newCall = dyn_cast<llvm::CallBase>(Val: RV.getScalarVal())) {
1680 if (auto *CGDI = getDebugInfo()) {
1681 // Set !heapallocsite metadata on the call to operator new.
1682 CGDI->addHeapAllocSiteMetadata(CallSite: newCall, AllocatedTy: allocType, Loc: E->getExprLoc());
1683 }
1684 if (SanOpts.has(K: SanitizerKind::AllocToken)) {
1685 // Set !alloc_token metadata.
1686 EmitAllocToken(CB: newCall, AllocType: allocType);
1687 }
1688 }
1689
1690 // If this was a call to a global replaceable allocation function that does
1691 // not take an alignment argument, the allocator is known to produce
1692 // storage that's suitably aligned for any object that fits, up to a known
1693 // threshold. Otherwise assume it's suitably aligned for the allocated type.
1694 CharUnits allocationAlign = allocAlign;
1695 if (!E->passAlignment() &&
1696 allocator->isReplaceableGlobalAllocationFunction()) {
1697 unsigned AllocatorAlign = llvm::bit_floor(Value: std::min<uint64_t>(
1698 a: Target.getNewAlign(), b: getContext().getTypeSize(T: allocType)));
1699 allocationAlign = std::max(
1700 a: allocationAlign, b: getContext().toCharUnitsFromBits(BitSize: AllocatorAlign));
1701 }
1702
1703 allocation = Address(RV.getScalarVal(), Int8Ty, allocationAlign);
1704 }
1705
1706 // Emit a null check on the allocation result if the allocation
1707 // function is allowed to return null (because it has a non-throwing
1708 // exception spec or is the reserved placement new) and we have an
1709 // interesting initializer will be running sanitizers on the initialization.
1710 bool nullCheck = E->shouldNullCheckAllocation() &&
1711 (!allocType.isPODType(Context: getContext()) || E->hasInitializer() ||
1712 sanitizePerformTypeCheck());
1713
1714 llvm::BasicBlock *nullCheckBB = nullptr;
1715 llvm::BasicBlock *contBB = nullptr;
1716
1717 // The null-check means that the initializer is conditionally
1718 // evaluated.
1719 ConditionalEvaluation conditional(*this);
1720
1721 if (nullCheck) {
1722 conditional.begin(CGF&: *this);
1723
1724 nullCheckBB = Builder.GetInsertBlock();
1725 llvm::BasicBlock *notNullBB = createBasicBlock(name: "new.notnull");
1726 contBB = createBasicBlock(name: "new.cont");
1727
1728 llvm::Value *isNull = Builder.CreateIsNull(Addr: allocation, Name: "new.isnull");
1729 Builder.CreateCondBr(Cond: isNull, True: contBB, False: notNullBB);
1730 EmitBlock(BB: notNullBB);
1731 }
1732
1733 // If there's an operator delete, enter a cleanup to call it if an
1734 // exception is thrown.
1735 EHScopeStack::stable_iterator operatorDeleteCleanup;
1736 llvm::Instruction *cleanupDominator = nullptr;
1737 if (E->getOperatorDelete() &&
1738 !E->getOperatorDelete()->isReservedGlobalPlacementOperator()) {
1739 // A potentially-throwing constructor inside __try requires C++ object
1740 // unwinding, which is incompatible with SEH.
1741 if (getLangOpts().CXXExceptions && currentFunctionUsesSEHTry()) {
1742 if (const auto *ConstructExpr = E->getConstructExpr()) {
1743 const auto *FPT = ConstructExpr->getConstructor()
1744 ->getType()
1745 ->castAs<FunctionProtoType>();
1746 if (!FPT->isNothrow())
1747 getContext().getDiagnostics().Report(Loc: E->getBeginLoc(),
1748 DiagID: diag::err_seh_object_unwinding);
1749 }
1750 }
1751 EnterNewDeleteCleanup(CGF&: *this, E, TypeIdentity: TypeIdentityArg, NewPtr: allocation, AllocSize: allocSize,
1752 AllocAlign: allocAlign, NewArgs: allocatorArgs);
1753 operatorDeleteCleanup = EHStack.stable_begin();
1754 cleanupDominator = Builder.CreateUnreachable();
1755 }
1756
1757 assert((allocSize == allocSizeWithoutCookie) ==
1758 CalculateCookiePadding(*this, E).isZero());
1759 if (allocSize != allocSizeWithoutCookie) {
1760 assert(E->isArray());
1761 allocation = CGM.getCXXABI().InitializeArrayCookie(
1762 CGF&: *this, NewPtr: allocation, NumElements: numElements, expr: E, ElementType: allocType);
1763 }
1764
1765 llvm::Type *elementTy = ConvertTypeForMem(T: allocType);
1766 Address result = allocation.withElementType(ElemTy: elementTy);
1767
1768 // Passing pointer through launder.invariant.group to avoid propagation of
1769 // vptrs information which may be included in previous type.
1770 // To not break LTO with different optimizations levels, we do it regardless
1771 // of optimization level.
1772 if (CGM.getCodeGenOpts().StrictVTablePointers &&
1773 allocator->isReservedGlobalPlacementOperator())
1774 result = Builder.CreateLaunderInvariantGroup(Addr: result);
1775
1776 // Emit sanitizer checks for pointer value now, so that in the case of an
1777 // array it was checked only once and not at each constructor call. We may
1778 // have already checked that the pointer is non-null.
1779 // FIXME: If we have an array cookie and a potentially-throwing allocator,
1780 // we'll null check the wrong pointer here.
1781 SanitizerSet SkippedChecks;
1782 SkippedChecks.set(K: SanitizerKind::Null, Value: nullCheck);
1783 EmitTypeCheck(TCK: CodeGenFunction::TCK_ConstructorCall,
1784 Loc: E->getAllocatedTypeSourceInfo()->getTypeLoc().getBeginLoc(),
1785 Addr: result, Type: allocType, Alignment: result.getAlignment(), SkippedChecks,
1786 ArraySize: numElements);
1787
1788 EmitNewInitializer(CGF&: *this, E, ElementType: allocType, ElementTy: elementTy, NewPtr: result, NumElements: numElements,
1789 AllocSizeWithoutCookie: allocSizeWithoutCookie);
1790 llvm::Value *resultPtr = result.emitRawPointer(CGF&: *this);
1791
1792 // Deactivate the 'operator delete' cleanup if we finished
1793 // initialization.
1794 if (operatorDeleteCleanup.isValid()) {
1795 DeactivateCleanupBlock(Cleanup: operatorDeleteCleanup, DominatingIP: cleanupDominator);
1796 cleanupDominator->eraseFromParent();
1797 }
1798
1799 if (nullCheck) {
1800 conditional.end(CGF&: *this);
1801
1802 llvm::BasicBlock *notNullBB = Builder.GetInsertBlock();
1803 EmitBlock(BB: contBB);
1804
1805 llvm::PHINode *PHI = Builder.CreatePHI(Ty: resultPtr->getType(), NumReservedValues: 2);
1806 PHI->addIncoming(V: resultPtr, BB: notNullBB);
1807 PHI->addIncoming(V: llvm::Constant::getNullValue(Ty: resultPtr->getType()),
1808 BB: nullCheckBB);
1809
1810 resultPtr = PHI;
1811 }
1812
1813 return resultPtr;
1814}
1815
1816void CodeGenFunction::EmitDeleteCall(const FunctionDecl *DeleteFD,
1817 llvm::Value *DeletePtr, QualType DeleteTy,
1818 llvm::Value *NumElements,
1819 CharUnits CookieSize,
1820 llvm::Constant *CalleeOverride) {
1821 assert((!NumElements && CookieSize.isZero()) ||
1822 DeleteFD->getOverloadedOperator() == OO_Array_Delete);
1823
1824 const auto *DeleteFTy = DeleteFD->getType()->castAs<FunctionProtoType>();
1825 CallArgList DeleteArgs;
1826
1827 auto Params = DeleteFD->getUsualDeleteParams();
1828 auto ParamTypeIt = DeleteFTy->param_type_begin();
1829
1830 std::optional<llvm::AllocaInst *> TagAlloca;
1831 auto EmitTag = [&](QualType TagType, const char *TagName) {
1832 assert(!TagAlloca);
1833 llvm::Type *Ty = getTypes().ConvertType(T: TagType);
1834 CharUnits Align = CGM.getNaturalTypeAlignment(T: TagType);
1835 llvm::AllocaInst *TagAllocation = CreateTempAlloca(Ty, Name: TagName);
1836 TagAllocation->setAlignment(Align.getAsAlign());
1837 DeleteArgs.add(rvalue: RValue::getAggregate(addr: Address(TagAllocation, Ty, Align)),
1838 type: TagType);
1839 TagAlloca = TagAllocation;
1840 };
1841
1842 // Pass std::type_identity tag if present
1843 if (isTypeAwareAllocation(Mode: Params.TypeAwareDelete))
1844 EmitTag(*ParamTypeIt++, "typeaware.delete.tag");
1845
1846 // Pass the pointer itself.
1847 QualType ArgTy = *ParamTypeIt++;
1848 DeleteArgs.add(rvalue: RValue::get(V: DeletePtr), type: ArgTy);
1849
1850 // Pass the std::destroying_delete tag if present.
1851 if (Params.DestroyingDelete)
1852 EmitTag(*ParamTypeIt++, "destroying.delete.tag");
1853
1854 // Pass the size if the delete function has a size_t parameter.
1855 if (Params.Size) {
1856 QualType SizeType = *ParamTypeIt++;
1857 CharUnits DeleteTypeSize = getContext().getTypeSizeInChars(T: DeleteTy);
1858 llvm::Value *Size = llvm::ConstantInt::get(Ty: ConvertType(T: SizeType),
1859 V: DeleteTypeSize.getQuantity());
1860
1861 // For array new, multiply by the number of elements.
1862 if (NumElements)
1863 Size = Builder.CreateMul(LHS: Size, RHS: NumElements);
1864
1865 // If there is a cookie, add the cookie size.
1866 if (!CookieSize.isZero())
1867 Size = Builder.CreateAdd(
1868 LHS: Size, RHS: llvm::ConstantInt::get(Ty: SizeTy, V: CookieSize.getQuantity()));
1869
1870 DeleteArgs.add(rvalue: RValue::get(V: Size), type: SizeType);
1871 }
1872
1873 // Pass the alignment if the delete function has an align_val_t parameter.
1874 if (isAlignedAllocation(Mode: Params.Alignment)) {
1875 QualType AlignValType = *ParamTypeIt++;
1876 CharUnits DeleteTypeAlign =
1877 getContext().toCharUnitsFromBits(BitSize: getContext().getTypeAlignIfKnown(
1878 T: DeleteTy, NeedsPreferredAlignment: true /* NeedsPreferredAlignment */));
1879 llvm::Value *Align = llvm::ConstantInt::get(Ty: ConvertType(T: AlignValType),
1880 V: DeleteTypeAlign.getQuantity());
1881 DeleteArgs.add(rvalue: RValue::get(V: Align), type: AlignValType);
1882 }
1883
1884 assert(ParamTypeIt == DeleteFTy->param_type_end() &&
1885 "unknown parameter to usual delete function");
1886
1887 // Emit the call to delete.
1888 EmitNewDeleteCall(CGF&: *this, CalleeDecl: DeleteFD, CalleeType: DeleteFTy, Args: DeleteArgs, CalleeOverride);
1889
1890 // If call argument lowering didn't use a generated tag argument alloca we
1891 // remove them
1892 if (TagAlloca && (*TagAlloca)->use_empty())
1893 (*TagAlloca)->eraseFromParent();
1894}
1895namespace {
1896/// Calls the given 'operator delete' on a single object.
1897struct CallObjectDelete final : EHScopeStack::Cleanup {
1898 llvm::Value *Ptr;
1899 const FunctionDecl *OperatorDelete;
1900 QualType ElementType;
1901
1902 CallObjectDelete(llvm::Value *Ptr, const FunctionDecl *OperatorDelete,
1903 QualType ElementType)
1904 : Ptr(Ptr), OperatorDelete(OperatorDelete), ElementType(ElementType) {}
1905
1906 void Emit(CodeGenFunction &CGF, Flags flags) override {
1907 CGF.EmitDeleteCall(DeleteFD: OperatorDelete, DeletePtr: Ptr, DeleteTy: ElementType);
1908 }
1909};
1910} // namespace
1911
1912void CodeGenFunction::pushCallObjectDeleteCleanup(
1913 const FunctionDecl *OperatorDelete, llvm::Value *CompletePtr,
1914 QualType ElementType) {
1915 EHStack.pushCleanup<CallObjectDelete>(Kind: NormalAndEHCleanup, A: CompletePtr,
1916 A: OperatorDelete, A: ElementType);
1917}
1918
1919/// Emit the code for deleting a single object with a destroying operator
1920/// delete. If the element type has a non-virtual destructor, Ptr has already
1921/// been converted to the type of the parameter of 'operator delete'. Otherwise
1922/// Ptr points to an object of the static type.
1923static void EmitDestroyingObjectDelete(CodeGenFunction &CGF,
1924 const CXXDeleteExpr *DE, Address Ptr,
1925 QualType ElementType) {
1926 auto *Dtor = ElementType->getAsCXXRecordDecl()->getDestructor();
1927 if (Dtor && Dtor->isVirtual())
1928 CGF.CGM.getCXXABI().emitVirtualObjectDelete(CGF, DE, Ptr, ElementType,
1929 Dtor);
1930 else
1931 CGF.EmitDeleteCall(DeleteFD: DE->getOperatorDelete(), DeletePtr: Ptr.emitRawPointer(CGF),
1932 DeleteTy: ElementType);
1933}
1934
1935static CXXDestructorDecl *TryDevirtualizeDtorCall(const CXXDeleteExpr *E,
1936 CXXDestructorDecl *Dtor,
1937 const LangOptions &LO) {
1938 assert(Dtor && Dtor->isVirtual() && "virtual dtor is expected");
1939 const Expr *DBase = E->getArgument();
1940 if (auto *MaybeDevirtualizedDtor = dyn_cast_or_null<CXXDestructorDecl>(
1941 Val: Dtor->getDevirtualizedMethod(Base: DBase, IsAppleKext: LO.AppleKext))) {
1942 const CXXRecordDecl *DevirtualizedClass =
1943 MaybeDevirtualizedDtor->getParent();
1944 if (declaresSameEntity(D1: getCXXRecord(E: DBase), D2: DevirtualizedClass)) {
1945 // Devirtualized to the class of the base type (the type of the
1946 // whole expression).
1947 return MaybeDevirtualizedDtor;
1948 }
1949 // Devirtualized to some other type. Would need to cast the this
1950 // pointer to that type but we don't have support for that yet, so
1951 // do a virtual call. FIXME: handle the case where it is
1952 // devirtualized to the derived type (the type of the inner
1953 // expression) as in EmitCXXMemberOrOperatorMemberCallExpr.
1954 }
1955 return nullptr;
1956}
1957
1958/// Emit the code for deleting a single object.
1959/// \return \c true if we started emitting UnconditionalDeleteBlock, \c false
1960/// if not.
1961static bool EmitObjectDelete(CodeGenFunction &CGF, const CXXDeleteExpr *DE,
1962 Address Ptr, QualType ElementType,
1963 llvm::BasicBlock *UnconditionalDeleteBlock) {
1964 // C++11 [expr.delete]p3:
1965 // If the static type of the object to be deleted is different from its
1966 // dynamic type, the static type shall be a base class of the dynamic type
1967 // of the object to be deleted and the static type shall have a virtual
1968 // destructor or the behavior is undefined.
1969 CGF.EmitTypeCheck(TCK: CodeGenFunction::TCK_MemberCall, Loc: DE->getExprLoc(), Addr: Ptr,
1970 Type: ElementType);
1971
1972 const FunctionDecl *OperatorDelete = DE->getOperatorDelete();
1973 assert(!OperatorDelete->isDestroyingOperatorDelete());
1974
1975 // Find the destructor for the type, if applicable. If the
1976 // destructor is virtual, we'll just emit the vcall and return.
1977 CXXDestructorDecl *Dtor = nullptr;
1978 if (const auto *RD = ElementType->getAsCXXRecordDecl()) {
1979 if (RD->hasDefinition() && !RD->hasTrivialDestructor()) {
1980 Dtor = RD->getDestructor();
1981
1982 if (Dtor->isVirtual()) {
1983 if (auto *DevirtualizedDtor =
1984 TryDevirtualizeDtorCall(E: DE, Dtor, LO: CGF.CGM.getLangOpts())) {
1985 Dtor = DevirtualizedDtor;
1986 } else {
1987 CGF.CGM.getCXXABI().emitVirtualObjectDelete(CGF, DE, Ptr, ElementType,
1988 Dtor);
1989 return false;
1990 }
1991 }
1992 }
1993 }
1994
1995 // Make sure that we call delete even if the dtor throws.
1996 // This doesn't have to a conditional cleanup because we're going
1997 // to pop it off in a second.
1998 CGF.EHStack.pushCleanup<CallObjectDelete>(
1999 Kind: NormalAndEHCleanup, A: Ptr.emitRawPointer(CGF), A: OperatorDelete, A: ElementType);
2000
2001 if (Dtor)
2002 CGF.EmitCXXDestructorCall(D: Dtor, Type: Dtor_Complete,
2003 /*ForVirtualBase=*/false,
2004 /*Delegating=*/false, This: Ptr, ThisTy: ElementType);
2005 else if (auto Lifetime = ElementType.getObjCLifetime()) {
2006 switch (Lifetime) {
2007 case Qualifiers::OCL_None:
2008 case Qualifiers::OCL_ExplicitNone:
2009 case Qualifiers::OCL_Autoreleasing:
2010 break;
2011
2012 case Qualifiers::OCL_Strong:
2013 CGF.EmitARCDestroyStrong(addr: Ptr, precise: ARCPreciseLifetime);
2014 break;
2015
2016 case Qualifiers::OCL_Weak:
2017 CGF.EmitARCDestroyWeak(addr: Ptr);
2018 break;
2019 }
2020 }
2021
2022 // When optimizing for size, call 'operator delete' unconditionally.
2023 if (CGF.CGM.getCodeGenOpts().OptimizeSize > 1) {
2024 CGF.EmitBlock(BB: UnconditionalDeleteBlock);
2025 CGF.PopCleanupBlock();
2026 return true;
2027 }
2028
2029 CGF.PopCleanupBlock();
2030 return false;
2031}
2032
2033namespace {
2034/// Calls the given 'operator delete' on an array of objects.
2035struct CallArrayDelete final : EHScopeStack::Cleanup {
2036 llvm::Value *Ptr;
2037 const FunctionDecl *OperatorDelete;
2038 llvm::Value *NumElements;
2039 QualType ElementType;
2040 CharUnits CookieSize;
2041
2042 CallArrayDelete(llvm::Value *Ptr, const FunctionDecl *OperatorDelete,
2043 llvm::Value *NumElements, QualType ElementType,
2044 CharUnits CookieSize)
2045 : Ptr(Ptr), OperatorDelete(OperatorDelete), NumElements(NumElements),
2046 ElementType(ElementType), CookieSize(CookieSize) {}
2047
2048 void Emit(CodeGenFunction &CGF, Flags flags) override {
2049 CGF.EmitDeleteCall(DeleteFD: OperatorDelete, DeletePtr: Ptr, DeleteTy: ElementType, NumElements,
2050 CookieSize);
2051 }
2052};
2053} // namespace
2054
2055/// Emit the code for deleting an array of objects.
2056static void EmitArrayDelete(CodeGenFunction &CGF, const CXXDeleteExpr *E,
2057 Address deletedPtr, QualType elementType) {
2058 llvm::Value *numElements = nullptr;
2059 llvm::Value *allocatedPtr = nullptr;
2060 CharUnits cookieSize;
2061 CGF.CGM.getCXXABI().ReadArrayCookie(CGF, Ptr: deletedPtr, expr: E, ElementType: elementType,
2062 NumElements&: numElements, AllocPtr&: allocatedPtr, CookieSize&: cookieSize);
2063
2064 assert(allocatedPtr && "ReadArrayCookie didn't set allocated pointer");
2065
2066 // Make sure that we call delete even if one of the dtors throws.
2067 const FunctionDecl *operatorDelete = E->getOperatorDelete();
2068 CGF.EHStack.pushCleanup<CallArrayDelete>(Kind: NormalAndEHCleanup, A: allocatedPtr,
2069 A: operatorDelete, A: numElements,
2070 A: elementType, A: cookieSize);
2071
2072 // Destroy the elements.
2073 if (QualType::DestructionKind dtorKind = elementType.isDestructedType()) {
2074 assert(numElements && "no element count for a type with a destructor!");
2075
2076 CharUnits elementSize = CGF.getContext().getTypeSizeInChars(T: elementType);
2077 CharUnits elementAlign =
2078 deletedPtr.getAlignment().alignmentOfArrayElement(elementSize);
2079
2080 llvm::Value *arrayBegin = deletedPtr.emitRawPointer(CGF);
2081 llvm::Value *arrayEnd = CGF.Builder.CreateInBoundsGEP(
2082 Ty: deletedPtr.getElementType(), Ptr: arrayBegin, IdxList: numElements, Name: "delete.end");
2083
2084 // Note that it is legal to allocate a zero-length array, and we
2085 // can never fold the check away because the length should always
2086 // come from a cookie.
2087 CGF.emitArrayDestroy(begin: arrayBegin, end: arrayEnd, elementType, elementAlign,
2088 destroyer: CGF.getDestroyer(destructionKind: dtorKind),
2089 /*checkZeroLength*/ true,
2090 useEHCleanup: CGF.needsEHCleanup(kind: dtorKind));
2091 }
2092
2093 // Pop the cleanup block.
2094 CGF.PopCleanupBlock();
2095}
2096
2097void CodeGenFunction::EmitCXXDeleteExpr(const CXXDeleteExpr *E) {
2098 const Expr *Arg = E->getArgument();
2099 Address Ptr = EmitPointerWithAlignment(Addr: Arg);
2100
2101 // If this is a ::delete expression (explicit global scope) on a class type
2102 // with a non-trivial destructor, note it so we emit __global_delete
2103 // forwarding bodies. This matches MSVC which only engages the __global_delete
2104 // machinery when a deleting destructor is involved:
2105 // - a plain `delete`/`delete[]` (no `::`) never triggers it, even when it
2106 // resolves to a global operator delete;
2107 // - `::delete` on a non-class type (e.g. `::delete intPtr`) or on a class
2108 // with a trivial destructor is lowered as a plain direct operator delete
2109 // and does not trigger it;
2110 // - the destructor's virtualness and the presence of a class-level
2111 // operator delete are both irrelevant to the trigger.
2112 if (E->isGlobalDelete() && CGM.getTarget().getCXXABI().isMicrosoft()) {
2113 const CXXRecordDecl *RD = E->getDestroyedType()->getAsCXXRecordDecl();
2114 if (RD && RD->hasDefinition() && !RD->hasTrivialDestructor()) {
2115 CGM.noteDirectGlobalDelete();
2116 // Ensure a __global_delete wrapper (and thus a strong forwarding body)
2117 // is emitted in THIS TU for the resolved global ::operator delete, even
2118 // when no vector deleting destructor here references it. Without this, a
2119 // TU that only does ::delete (with the deleting destructor defined in
2120 // another TU) would emit no forwarder, leaving the wrapper bound to the
2121 // trapping empty fallback and crashing at runtime.
2122 const FunctionDecl *OD = E->getOperatorDelete();
2123 assert(!isa<CXXMethodDecl>(OD) &&
2124 "global ::delete should resolve to a namespace-scope "
2125 "operator delete");
2126 CGM.getOrCreateMSVCGlobalDeleteWrapper(GlobOD: OD);
2127 }
2128 }
2129
2130 // Null check the pointer.
2131 //
2132 // We could avoid this null check if we can determine that the object
2133 // destruction is trivial and doesn't require an array cookie; we can
2134 // unconditionally perform the operator delete call in that case. For now, we
2135 // assume that deleted pointers are null rarely enough that it's better to
2136 // keep the branch. This might be worth revisiting for a -O0 code size win.
2137 llvm::BasicBlock *DeleteNotNull = createBasicBlock(name: "delete.notnull");
2138 llvm::BasicBlock *DeleteEnd = createBasicBlock(name: "delete.end");
2139
2140 llvm::Value *IsNull = Builder.CreateIsNull(Addr: Ptr, Name: "isnull");
2141
2142 Builder.CreateCondBr(Cond: IsNull, True: DeleteEnd, False: DeleteNotNull);
2143 EmitBlock(BB: DeleteNotNull);
2144 Ptr.setKnownNonNull();
2145
2146 QualType DeleteTy = E->getDestroyedType();
2147
2148 // A destroying operator delete overrides the entire operation of the
2149 // delete expression.
2150 if (E->getOperatorDelete()->isDestroyingOperatorDelete()) {
2151 EmitDestroyingObjectDelete(CGF&: *this, DE: E, Ptr, ElementType: DeleteTy);
2152 EmitBlock(BB: DeleteEnd);
2153 return;
2154 }
2155
2156 // We might be deleting a pointer to array.
2157 DeleteTy = getContext().getBaseElementType(QT: DeleteTy);
2158 Ptr = Ptr.withElementType(ElemTy: ConvertTypeForMem(T: DeleteTy));
2159
2160 if (E->isArrayForm() &&
2161 CGM.getContext().getTargetInfo().emitVectorDeletingDtors(
2162 CGM.getContext().getLangOpts())) {
2163 if (auto *RD = DeleteTy->getAsCXXRecordDecl()) {
2164 auto *Dtor = RD->getDestructor();
2165 if (Dtor && Dtor->isVirtual()) {
2166 // Emit normal loop over the array elements if we can easily
2167 // devirtualize destructor call.
2168 // Emit virtual call to vector deleting destructor otherwise.
2169 if (!TryDevirtualizeDtorCall(E, Dtor, LO: CGM.getLangOpts())) {
2170 llvm::Value *NumElements = nullptr;
2171 llvm::Value *AllocatedPtr = nullptr;
2172 CharUnits CookieSize;
2173 llvm::BasicBlock *BodyBB = createBasicBlock(name: "vdtor.call");
2174 llvm::BasicBlock *DoneBB = createBasicBlock(name: "vdtor.nocall");
2175 // Check array cookie to see if the array has length 0. Don't call
2176 // the destructor in that case.
2177 CGM.getCXXABI().ReadArrayCookie(CGF&: *this, Ptr, expr: E, ElementType: DeleteTy, NumElements,
2178 AllocPtr&: AllocatedPtr, CookieSize);
2179
2180 auto *CondTy = cast<llvm::IntegerType>(Val: NumElements->getType());
2181 llvm::Value *IsEmpty = Builder.CreateICmpEQ(
2182 LHS: NumElements, RHS: llvm::ConstantInt::get(Ty: CondTy, V: 0));
2183 Builder.CreateCondBr(Cond: IsEmpty, True: DoneBB, False: BodyBB);
2184
2185 // Delete cookie for empty array.
2186 const FunctionDecl *OperatorDelete = E->getOperatorDelete();
2187 EmitBlock(BB: DoneBB);
2188 EmitDeleteCall(DeleteFD: OperatorDelete, DeletePtr: AllocatedPtr, DeleteTy, NumElements,
2189 CookieSize);
2190 EmitBranch(Block: DeleteEnd);
2191
2192 EmitBlock(BB: BodyBB);
2193 CGM.getCXXABI().emitVirtualObjectDelete(CGF&: *this, DE: E, Ptr, ElementType: DeleteTy,
2194 Dtor);
2195 EmitBlock(BB: DeleteEnd);
2196 return;
2197 }
2198 }
2199 }
2200 }
2201
2202 if (E->isArrayForm()) {
2203 EmitArrayDelete(CGF&: *this, E, deletedPtr: Ptr, elementType: DeleteTy);
2204 EmitBlock(BB: DeleteEnd);
2205 } else {
2206 if (!EmitObjectDelete(CGF&: *this, DE: E, Ptr, ElementType: DeleteTy, UnconditionalDeleteBlock: DeleteEnd))
2207 EmitBlock(BB: DeleteEnd);
2208 }
2209}
2210
2211static Address EmitTypeidOperand(CodeGenFunction &CGF, const Expr *E,
2212 bool HasNullCheck) {
2213 // Get the vtable pointer.
2214 Address ThisPtr = CGF.EmitLValue(E).getAddress();
2215
2216 QualType SrcRecordTy = E->getType();
2217
2218 // C++ [class.cdtor]p4:
2219 // If the operand of typeid refers to the object under construction or
2220 // destruction and the static type of the operand is neither the constructor
2221 // or destructor’s class nor one of its bases, the behavior is undefined.
2222 CGF.EmitTypeCheck(TCK: CodeGenFunction::TCK_DynamicOperation, Loc: E->getExprLoc(),
2223 Addr: ThisPtr, Type: SrcRecordTy);
2224
2225 // Whether we need an explicit null pointer check. For example, with the
2226 // Microsoft ABI, if this is a call to __RTtypeid, the null pointer check and
2227 // exception throw is inside the __RTtypeid(nullptr) call
2228 if (HasNullCheck &&
2229 CGF.CGM.getCXXABI().shouldTypeidBeNullChecked(SrcRecordTy)) {
2230 llvm::BasicBlock *BadTypeidBlock =
2231 CGF.createBasicBlock(name: "typeid.bad_typeid");
2232 llvm::BasicBlock *EndBlock = CGF.createBasicBlock(name: "typeid.end");
2233
2234 llvm::Value *IsNull = CGF.Builder.CreateIsNull(Addr: ThisPtr);
2235 CGF.Builder.CreateCondBr(Cond: IsNull, True: BadTypeidBlock, False: EndBlock);
2236
2237 CGF.EmitBlock(BB: BadTypeidBlock);
2238 CGF.CGM.getCXXABI().EmitBadTypeidCall(CGF);
2239 CGF.EmitBlock(BB: EndBlock);
2240 }
2241
2242 return ThisPtr;
2243}
2244
2245llvm::Value *CodeGenFunction::EmitCXXTypeidExpr(const CXXTypeidExpr *E) {
2246 // Ideally, we would like to use GlobalsInt8PtrTy here, however, we cannot,
2247 // primarily because the result of applying typeid is a value of type
2248 // type_info, which is declared & defined by the standard library
2249 // implementation and expects to operate on the generic (default) AS.
2250 // https://reviews.llvm.org/D157452 has more context, and a possible solution.
2251 llvm::Type *PtrTy = Int8PtrTy;
2252 LangAS GlobAS = CGM.GetGlobalVarAddressSpace(D: nullptr);
2253
2254 auto MaybeASCast = [=](llvm::Constant *TypeInfo) {
2255 if (GlobAS == LangAS::Default)
2256 return TypeInfo;
2257 return CGM.performAddrSpaceCast(Src: TypeInfo, DestTy: PtrTy);
2258 };
2259
2260 if (E->isTypeOperand()) {
2261 llvm::Constant *TypeInfo =
2262 CGM.GetAddrOfRTTIDescriptor(Ty: E->getTypeOperand(Context: getContext()));
2263 return MaybeASCast(TypeInfo);
2264 }
2265
2266 const Expr *Operand = E->getExprOperand();
2267 QualType OperandTy = Operand->getType();
2268
2269 // C++ [expr.typeid]p2:
2270 // When typeid is applied to a glvalue expression whose type is a
2271 // polymorphic class type, the result refers to a std::type_info object
2272 // representing the type of the most derived object (that is, the dynamic
2273 // type) to which the glvalue refers.
2274 if (E->isPotentiallyEvaluated()) {
2275 Address ThisPtr = EmitTypeidOperand(CGF&: *this, E: Operand, HasNullCheck: E->hasNullCheck());
2276 if (!E->isMostDerived(Context: getContext()))
2277 return CGM.getCXXABI().EmitTypeid(CGF&: *this, SrcRecordTy: OperandTy, ThisPtr, StdTypeInfoPtrTy: PtrTy);
2278 // If the operand is already most derived object, no need to look up vtable.
2279 }
2280
2281 return MaybeASCast(CGM.GetAddrOfRTTIDescriptor(Ty: OperandTy));
2282}
2283
2284static llvm::Value *EmitDynamicCastToNull(CodeGenFunction &CGF,
2285 QualType DestTy) {
2286 llvm::Type *DestLTy = CGF.ConvertType(T: DestTy);
2287 if (DestTy->isPointerType())
2288 return llvm::Constant::getNullValue(Ty: DestLTy);
2289
2290 /// C++ [expr.dynamic.cast]p9:
2291 /// A failed cast to reference type throws std::bad_cast
2292 if (!CGF.CGM.getCXXABI().EmitBadCastCall(CGF))
2293 return nullptr;
2294
2295 CGF.Builder.ClearInsertionPoint();
2296 return llvm::PoisonValue::get(T: DestLTy);
2297}
2298
2299llvm::Value *CodeGenFunction::EmitDynamicCast(Address ThisAddr,
2300 const CXXDynamicCastExpr *DCE) {
2301 CGM.EmitExplicitCastExprType(E: DCE, CGF: this);
2302 QualType DestTy = DCE->getTypeAsWritten();
2303
2304 QualType SrcTy = DCE->getSubExpr()->getType();
2305
2306 // C++ [expr.dynamic.cast]p7:
2307 // If T is "pointer to cv void," then the result is a pointer to the most
2308 // derived object pointed to by v.
2309 bool IsDynamicCastToVoid = DestTy->isVoidPointerType();
2310 QualType SrcRecordTy;
2311 QualType DestRecordTy;
2312 if (IsDynamicCastToVoid) {
2313 SrcRecordTy = SrcTy->getPointeeType();
2314 // No DestRecordTy.
2315 } else if (const PointerType *DestPTy = DestTy->getAs<PointerType>()) {
2316 SrcRecordTy = SrcTy->castAs<PointerType>()->getPointeeType();
2317 DestRecordTy = DestPTy->getPointeeType();
2318 } else {
2319 SrcRecordTy = SrcTy;
2320 DestRecordTy = DestTy->castAs<ReferenceType>()->getPointeeType();
2321 }
2322
2323 // C++ [class.cdtor]p5:
2324 // If the operand of the dynamic_cast refers to the object under
2325 // construction or destruction and the static type of the operand is not a
2326 // pointer to or object of the constructor or destructor’s own class or one
2327 // of its bases, the dynamic_cast results in undefined behavior.
2328 EmitTypeCheck(TCK: TCK_DynamicOperation, Loc: DCE->getExprLoc(), Addr: ThisAddr, Type: SrcRecordTy);
2329
2330 if (DCE->isAlwaysNull()) {
2331 if (llvm::Value *T = EmitDynamicCastToNull(CGF&: *this, DestTy)) {
2332 // Expression emission is expected to retain a valid insertion point.
2333 if (!Builder.GetInsertBlock())
2334 EmitBlock(BB: createBasicBlock(name: "dynamic_cast.unreachable"));
2335 return T;
2336 }
2337 }
2338
2339 assert(SrcRecordTy->isRecordType() && "source type must be a record type!");
2340
2341 // If the destination is effectively final, the cast succeeds if and only
2342 // if the dynamic type of the pointer is exactly the destination type.
2343 bool IsExact = !IsDynamicCastToVoid &&
2344 CGM.getCodeGenOpts().OptimizationLevel > 0 &&
2345 DestRecordTy->getAsCXXRecordDecl()->isEffectivelyFinal() &&
2346 CGM.getCXXABI().shouldEmitExactDynamicCast(DestRecordTy);
2347
2348 std::optional<CGCXXABI::ExactDynamicCastInfo> ExactCastInfo;
2349 if (IsExact) {
2350 ExactCastInfo = CGM.getCXXABI().getExactDynamicCastInfo(SrcRecordTy, DestTy,
2351 DestRecordTy);
2352 if (!ExactCastInfo) {
2353 llvm::Value *NullValue = EmitDynamicCastToNull(CGF&: *this, DestTy);
2354 if (!Builder.GetInsertBlock())
2355 EmitBlock(BB: createBasicBlock(name: "dynamic_cast.unreachable"));
2356 return NullValue;
2357 }
2358 }
2359
2360 // C++ [expr.dynamic.cast]p4:
2361 // If the value of v is a null pointer value in the pointer case, the result
2362 // is the null pointer value of type T.
2363 bool ShouldNullCheckSrcValue =
2364 IsExact || CGM.getCXXABI().shouldDynamicCastCallBeNullChecked(
2365 SrcIsPtr: SrcTy->isPointerType(), SrcRecordTy);
2366
2367 llvm::BasicBlock *CastNull = nullptr;
2368 llvm::BasicBlock *CastNotNull = nullptr;
2369 llvm::BasicBlock *CastEnd = createBasicBlock(name: "dynamic_cast.end");
2370
2371 if (ShouldNullCheckSrcValue) {
2372 CastNull = createBasicBlock(name: "dynamic_cast.null");
2373 CastNotNull = createBasicBlock(name: "dynamic_cast.notnull");
2374
2375 llvm::Value *IsNull = Builder.CreateIsNull(Addr: ThisAddr);
2376 Builder.CreateCondBr(Cond: IsNull, True: CastNull, False: CastNotNull);
2377 EmitBlock(BB: CastNotNull);
2378 }
2379
2380 llvm::Value *Value;
2381 if (IsDynamicCastToVoid) {
2382 Value = CGM.getCXXABI().emitDynamicCastToVoid(CGF&: *this, Value: ThisAddr, SrcRecordTy);
2383 } else if (IsExact) {
2384 // If the destination type is effectively final, this pointer points to the
2385 // right type if and only if its vptr has the right value.
2386 Value = CGM.getCXXABI().emitExactDynamicCast(
2387 CGF&: *this, Value: ThisAddr, SrcRecordTy, DestTy, DestRecordTy, CastInfo: *ExactCastInfo,
2388 CastSuccess: CastEnd, CastFail: CastNull);
2389 } else {
2390 assert(DestRecordTy->isRecordType() &&
2391 "destination type must be a record type!");
2392 Value = CGM.getCXXABI().emitDynamicCastCall(CGF&: *this, Value: ThisAddr, SrcRecordTy,
2393 DestTy, DestRecordTy, CastEnd);
2394 }
2395 CastNotNull = Builder.GetInsertBlock();
2396
2397 llvm::Value *NullValue = nullptr;
2398 if (ShouldNullCheckSrcValue) {
2399 EmitBranch(Block: CastEnd);
2400
2401 EmitBlock(BB: CastNull);
2402 NullValue = EmitDynamicCastToNull(CGF&: *this, DestTy);
2403 CastNull = Builder.GetInsertBlock();
2404
2405 EmitBranch(Block: CastEnd);
2406 }
2407
2408 EmitBlock(BB: CastEnd);
2409
2410 if (CastNull) {
2411 llvm::PHINode *PHI = Builder.CreatePHI(Ty: Value->getType(), NumReservedValues: 2);
2412 PHI->addIncoming(V: Value, BB: CastNotNull);
2413 PHI->addIncoming(V: NullValue, BB: CastNull);
2414
2415 Value = PHI;
2416 }
2417
2418 return Value;
2419}
2420