• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 //===--- CGExprCXX.cpp - Emit LLVM Code for C++ expressions ---------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This contains code dealing with code generation of C++ expressions
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "CodeGenFunction.h"
15 #include "CGCUDARuntime.h"
16 #include "CGCXXABI.h"
17 #include "CGDebugInfo.h"
18 #include "CGObjCRuntime.h"
19 #include "clang/CodeGen/CGFunctionInfo.h"
20 #include "clang/Frontend/CodeGenOptions.h"
21 #include "llvm/IR/CallSite.h"
22 #include "llvm/IR/Intrinsics.h"
23 
24 using namespace clang;
25 using namespace CodeGen;
26 
27 static RequiredArgs
commonEmitCXXMemberOrOperatorCall(CodeGenFunction & CGF,const CXXMethodDecl * MD,llvm::Value * This,llvm::Value * ImplicitParam,QualType ImplicitParamTy,const CallExpr * CE,CallArgList & Args)28 commonEmitCXXMemberOrOperatorCall(CodeGenFunction &CGF, const CXXMethodDecl *MD,
29                                   llvm::Value *This, llvm::Value *ImplicitParam,
30                                   QualType ImplicitParamTy, const CallExpr *CE,
31                                   CallArgList &Args) {
32   assert(CE == nullptr || isa<CXXMemberCallExpr>(CE) ||
33          isa<CXXOperatorCallExpr>(CE));
34   assert(MD->isInstance() &&
35          "Trying to emit a member or operator call expr on a static method!");
36 
37   // C++11 [class.mfct.non-static]p2:
38   //   If a non-static member function of a class X is called for an object that
39   //   is not of type X, or of a type derived from X, the behavior is undefined.
40   SourceLocation CallLoc;
41   if (CE)
42     CallLoc = CE->getExprLoc();
43   CGF.EmitTypeCheck(
44       isa<CXXConstructorDecl>(MD) ? CodeGenFunction::TCK_ConstructorCall
45                                   : CodeGenFunction::TCK_MemberCall,
46       CallLoc, This, CGF.getContext().getRecordType(MD->getParent()));
47 
48   // Push the this ptr.
49   Args.add(RValue::get(This), MD->getThisType(CGF.getContext()));
50 
51   // If there is an implicit parameter (e.g. VTT), emit it.
52   if (ImplicitParam) {
53     Args.add(RValue::get(ImplicitParam), ImplicitParamTy);
54   }
55 
56   const FunctionProtoType *FPT = MD->getType()->castAs<FunctionProtoType>();
57   RequiredArgs required = RequiredArgs::forPrototypePlus(FPT, Args.size(), MD);
58 
59   // And the rest of the call args.
60   if (CE) {
61     // Special case: skip first argument of CXXOperatorCall (it is "this").
62     unsigned ArgsToSkip = isa<CXXOperatorCallExpr>(CE) ? 1 : 0;
63     CGF.EmitCallArgs(Args, FPT, drop_begin(CE->arguments(), ArgsToSkip),
64                      CE->getDirectCallee());
65   } else {
66     assert(
67         FPT->getNumParams() == 0 &&
68         "No CallExpr specified for function with non-zero number of arguments");
69   }
70   return required;
71 }
72 
EmitCXXMemberOrOperatorCall(const CXXMethodDecl * MD,llvm::Value * Callee,ReturnValueSlot ReturnValue,llvm::Value * This,llvm::Value * ImplicitParam,QualType ImplicitParamTy,const CallExpr * CE)73 RValue CodeGenFunction::EmitCXXMemberOrOperatorCall(
74     const CXXMethodDecl *MD, llvm::Value *Callee, ReturnValueSlot ReturnValue,
75     llvm::Value *This, llvm::Value *ImplicitParam, QualType ImplicitParamTy,
76     const CallExpr *CE) {
77   const FunctionProtoType *FPT = MD->getType()->castAs<FunctionProtoType>();
78   CallArgList Args;
79   RequiredArgs required = commonEmitCXXMemberOrOperatorCall(
80       *this, MD, This, ImplicitParam, ImplicitParamTy, CE, Args);
81   return EmitCall(CGM.getTypes().arrangeCXXMethodCall(Args, FPT, required),
82                   Callee, ReturnValue, Args, MD);
83 }
84 
EmitCXXDestructorCall(const CXXDestructorDecl * DD,llvm::Value * Callee,llvm::Value * This,llvm::Value * ImplicitParam,QualType ImplicitParamTy,const CallExpr * CE,StructorType Type)85 RValue CodeGenFunction::EmitCXXDestructorCall(
86     const CXXDestructorDecl *DD, llvm::Value *Callee, llvm::Value *This,
87     llvm::Value *ImplicitParam, QualType ImplicitParamTy, const CallExpr *CE,
88     StructorType Type) {
89   CallArgList Args;
90   commonEmitCXXMemberOrOperatorCall(*this, DD, This, ImplicitParam,
91                                     ImplicitParamTy, CE, Args);
92   return EmitCall(CGM.getTypes().arrangeCXXStructorDeclaration(DD, Type),
93                   Callee, ReturnValueSlot(), Args, DD);
94 }
95 
getCXXRecord(const Expr * E)96 static CXXRecordDecl *getCXXRecord(const Expr *E) {
97   QualType T = E->getType();
98   if (const PointerType *PTy = T->getAs<PointerType>())
99     T = PTy->getPointeeType();
100   const RecordType *Ty = T->castAs<RecordType>();
101   return cast<CXXRecordDecl>(Ty->getDecl());
102 }
103 
104 // Note: This function also emit constructor calls to support a MSVC
105 // extensions allowing explicit constructor function call.
EmitCXXMemberCallExpr(const CXXMemberCallExpr * CE,ReturnValueSlot ReturnValue)106 RValue CodeGenFunction::EmitCXXMemberCallExpr(const CXXMemberCallExpr *CE,
107                                               ReturnValueSlot ReturnValue) {
108   const Expr *callee = CE->getCallee()->IgnoreParens();
109 
110   if (isa<BinaryOperator>(callee))
111     return EmitCXXMemberPointerCallExpr(CE, ReturnValue);
112 
113   const MemberExpr *ME = cast<MemberExpr>(callee);
114   const CXXMethodDecl *MD = cast<CXXMethodDecl>(ME->getMemberDecl());
115 
116   if (MD->isStatic()) {
117     // The method is static, emit it as we would a regular call.
118     llvm::Value *Callee = CGM.GetAddrOfFunction(MD);
119     return EmitCall(getContext().getPointerType(MD->getType()), Callee, CE,
120                     ReturnValue);
121   }
122 
123   bool HasQualifier = ME->hasQualifier();
124   NestedNameSpecifier *Qualifier = HasQualifier ? ME->getQualifier() : nullptr;
125   bool IsArrow = ME->isArrow();
126   const Expr *Base = ME->getBase();
127 
128   return EmitCXXMemberOrOperatorMemberCallExpr(
129       CE, MD, ReturnValue, HasQualifier, Qualifier, IsArrow, Base);
130 }
131 
EmitCXXMemberOrOperatorMemberCallExpr(const CallExpr * CE,const CXXMethodDecl * MD,ReturnValueSlot ReturnValue,bool HasQualifier,NestedNameSpecifier * Qualifier,bool IsArrow,const Expr * Base)132 RValue CodeGenFunction::EmitCXXMemberOrOperatorMemberCallExpr(
133     const CallExpr *CE, const CXXMethodDecl *MD, ReturnValueSlot ReturnValue,
134     bool HasQualifier, NestedNameSpecifier *Qualifier, bool IsArrow,
135     const Expr *Base) {
136   assert(isa<CXXMemberCallExpr>(CE) || isa<CXXOperatorCallExpr>(CE));
137 
138   // Compute the object pointer.
139   bool CanUseVirtualCall = MD->isVirtual() && !HasQualifier;
140 
141   const CXXMethodDecl *DevirtualizedMethod = nullptr;
142   if (CanUseVirtualCall && CanDevirtualizeMemberFunctionCall(Base, MD)) {
143     const CXXRecordDecl *BestDynamicDecl = Base->getBestDynamicClassType();
144     DevirtualizedMethod = MD->getCorrespondingMethodInClass(BestDynamicDecl);
145     assert(DevirtualizedMethod);
146     const CXXRecordDecl *DevirtualizedClass = DevirtualizedMethod->getParent();
147     const Expr *Inner = Base->ignoreParenBaseCasts();
148     if (DevirtualizedMethod->getReturnType().getCanonicalType() !=
149         MD->getReturnType().getCanonicalType())
150       // If the return types are not the same, this might be a case where more
151       // code needs to run to compensate for it. For example, the derived
152       // method might return a type that inherits form from the return
153       // type of MD and has a prefix.
154       // For now we just avoid devirtualizing these covariant cases.
155       DevirtualizedMethod = nullptr;
156     else if (getCXXRecord(Inner) == DevirtualizedClass)
157       // If the class of the Inner expression is where the dynamic method
158       // is defined, build the this pointer from it.
159       Base = Inner;
160     else if (getCXXRecord(Base) != DevirtualizedClass) {
161       // If the method is defined in a class that is not the best dynamic
162       // one or the one of the full expression, we would have to build
163       // a derived-to-base cast to compute the correct this pointer, but
164       // we don't have support for that yet, so do a virtual call.
165       DevirtualizedMethod = nullptr;
166     }
167   }
168 
169   Address This = Address::invalid();
170   if (IsArrow)
171     This = EmitPointerWithAlignment(Base);
172   else
173     This = EmitLValue(Base).getAddress();
174 
175 
176   if (MD->isTrivial() || (MD->isDefaulted() && MD->getParent()->isUnion())) {
177     if (isa<CXXDestructorDecl>(MD)) return RValue::get(nullptr);
178     if (isa<CXXConstructorDecl>(MD) &&
179         cast<CXXConstructorDecl>(MD)->isDefaultConstructor())
180       return RValue::get(nullptr);
181 
182     if (!MD->getParent()->mayInsertExtraPadding()) {
183       if (MD->isCopyAssignmentOperator() || MD->isMoveAssignmentOperator()) {
184         // We don't like to generate the trivial copy/move assignment operator
185         // when it isn't necessary; just produce the proper effect here.
186         // Special case: skip first argument of CXXOperatorCall (it is "this").
187         unsigned ArgsToSkip = isa<CXXOperatorCallExpr>(CE) ? 1 : 0;
188         Address RHS = EmitLValue(*(CE->arg_begin() + ArgsToSkip)).getAddress();
189         EmitAggregateAssign(This, RHS, CE->getType());
190         return RValue::get(This.getPointer());
191       }
192 
193       if (isa<CXXConstructorDecl>(MD) &&
194           cast<CXXConstructorDecl>(MD)->isCopyOrMoveConstructor()) {
195         // Trivial move and copy ctor are the same.
196         assert(CE->getNumArgs() == 1 && "unexpected argcount for trivial ctor");
197         Address RHS = EmitLValue(*CE->arg_begin()).getAddress();
198         EmitAggregateCopy(This, RHS, (*CE->arg_begin())->getType());
199         return RValue::get(This.getPointer());
200       }
201       llvm_unreachable("unknown trivial member function");
202     }
203   }
204 
205   // Compute the function type we're calling.
206   const CXXMethodDecl *CalleeDecl =
207       DevirtualizedMethod ? DevirtualizedMethod : MD;
208   const CGFunctionInfo *FInfo = nullptr;
209   if (const auto *Dtor = dyn_cast<CXXDestructorDecl>(CalleeDecl))
210     FInfo = &CGM.getTypes().arrangeCXXStructorDeclaration(
211         Dtor, StructorType::Complete);
212   else if (const auto *Ctor = dyn_cast<CXXConstructorDecl>(CalleeDecl))
213     FInfo = &CGM.getTypes().arrangeCXXStructorDeclaration(
214         Ctor, StructorType::Complete);
215   else
216     FInfo = &CGM.getTypes().arrangeCXXMethodDeclaration(CalleeDecl);
217 
218   llvm::FunctionType *Ty = CGM.getTypes().GetFunctionType(*FInfo);
219 
220   // C++ [class.virtual]p12:
221   //   Explicit qualification with the scope operator (5.1) suppresses the
222   //   virtual call mechanism.
223   //
224   // We also don't emit a virtual call if the base expression has a record type
225   // because then we know what the type is.
226   bool UseVirtualCall = CanUseVirtualCall && !DevirtualizedMethod;
227   llvm::Value *Callee;
228 
229   if (const CXXDestructorDecl *Dtor = dyn_cast<CXXDestructorDecl>(MD)) {
230     assert(CE->arg_begin() == CE->arg_end() &&
231            "Destructor shouldn't have explicit parameters");
232     assert(ReturnValue.isNull() && "Destructor shouldn't have return value");
233     if (UseVirtualCall) {
234       CGM.getCXXABI().EmitVirtualDestructorCall(
235           *this, Dtor, Dtor_Complete, This, cast<CXXMemberCallExpr>(CE));
236     } else {
237       if (getLangOpts().AppleKext && MD->isVirtual() && HasQualifier)
238         Callee = BuildAppleKextVirtualCall(MD, Qualifier, Ty);
239       else if (!DevirtualizedMethod)
240         Callee =
241             CGM.getAddrOfCXXStructor(Dtor, StructorType::Complete, FInfo, Ty);
242       else {
243         const CXXDestructorDecl *DDtor =
244           cast<CXXDestructorDecl>(DevirtualizedMethod);
245         Callee = CGM.GetAddrOfFunction(GlobalDecl(DDtor, Dtor_Complete), Ty);
246       }
247       EmitCXXMemberOrOperatorCall(MD, Callee, ReturnValue, This.getPointer(),
248                                   /*ImplicitParam=*/nullptr, QualType(), CE);
249     }
250     return RValue::get(nullptr);
251   }
252 
253   if (const CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(MD)) {
254     Callee = CGM.GetAddrOfFunction(GlobalDecl(Ctor, Ctor_Complete), Ty);
255   } else if (UseVirtualCall) {
256     Callee = CGM.getCXXABI().getVirtualFunctionPointer(*this, MD, This, Ty,
257                                                        CE->getLocStart());
258   } else {
259     if (SanOpts.has(SanitizerKind::CFINVCall) &&
260         MD->getParent()->isDynamicClass()) {
261       llvm::Value *VTable = GetVTablePtr(This, Int8PtrTy, MD->getParent());
262       EmitVTablePtrCheckForCall(MD->getParent(), VTable, CFITCK_NVCall,
263                                 CE->getLocStart());
264     }
265 
266     if (getLangOpts().AppleKext && MD->isVirtual() && HasQualifier)
267       Callee = BuildAppleKextVirtualCall(MD, Qualifier, Ty);
268     else if (!DevirtualizedMethod)
269       Callee = CGM.GetAddrOfFunction(MD, Ty);
270     else {
271       Callee = CGM.GetAddrOfFunction(DevirtualizedMethod, Ty);
272     }
273   }
274 
275   if (MD->isVirtual()) {
276     This = CGM.getCXXABI().adjustThisArgumentForVirtualFunctionCall(
277         *this, CalleeDecl, This, UseVirtualCall);
278   }
279 
280   return EmitCXXMemberOrOperatorCall(MD, Callee, ReturnValue, This.getPointer(),
281                                      /*ImplicitParam=*/nullptr, QualType(), CE);
282 }
283 
284 RValue
EmitCXXMemberPointerCallExpr(const CXXMemberCallExpr * E,ReturnValueSlot ReturnValue)285 CodeGenFunction::EmitCXXMemberPointerCallExpr(const CXXMemberCallExpr *E,
286                                               ReturnValueSlot ReturnValue) {
287   const BinaryOperator *BO =
288       cast<BinaryOperator>(E->getCallee()->IgnoreParens());
289   const Expr *BaseExpr = BO->getLHS();
290   const Expr *MemFnExpr = BO->getRHS();
291 
292   const MemberPointerType *MPT =
293     MemFnExpr->getType()->castAs<MemberPointerType>();
294 
295   const FunctionProtoType *FPT =
296     MPT->getPointeeType()->castAs<FunctionProtoType>();
297   const CXXRecordDecl *RD =
298     cast<CXXRecordDecl>(MPT->getClass()->getAs<RecordType>()->getDecl());
299 
300   // Get the member function pointer.
301   llvm::Value *MemFnPtr = EmitScalarExpr(MemFnExpr);
302 
303   // Emit the 'this' pointer.
304   Address This = Address::invalid();
305   if (BO->getOpcode() == BO_PtrMemI)
306     This = EmitPointerWithAlignment(BaseExpr);
307   else
308     This = EmitLValue(BaseExpr).getAddress();
309 
310   EmitTypeCheck(TCK_MemberCall, E->getExprLoc(), This.getPointer(),
311                 QualType(MPT->getClass(), 0));
312 
313   // Ask the ABI to load the callee.  Note that This is modified.
314   llvm::Value *ThisPtrForCall = nullptr;
315   llvm::Value *Callee =
316     CGM.getCXXABI().EmitLoadOfMemberFunctionPointer(*this, BO, This,
317                                              ThisPtrForCall, MemFnPtr, MPT);
318 
319   CallArgList Args;
320 
321   QualType ThisType =
322     getContext().getPointerType(getContext().getTagDeclType(RD));
323 
324   // Push the this ptr.
325   Args.add(RValue::get(ThisPtrForCall), ThisType);
326 
327   RequiredArgs required =
328       RequiredArgs::forPrototypePlus(FPT, 1, /*FD=*/nullptr);
329 
330   // And the rest of the call args
331   EmitCallArgs(Args, FPT, E->arguments());
332   return EmitCall(CGM.getTypes().arrangeCXXMethodCall(Args, FPT, required),
333                   Callee, ReturnValue, Args);
334 }
335 
336 RValue
EmitCXXOperatorMemberCallExpr(const CXXOperatorCallExpr * E,const CXXMethodDecl * MD,ReturnValueSlot ReturnValue)337 CodeGenFunction::EmitCXXOperatorMemberCallExpr(const CXXOperatorCallExpr *E,
338                                                const CXXMethodDecl *MD,
339                                                ReturnValueSlot ReturnValue) {
340   assert(MD->isInstance() &&
341          "Trying to emit a member call expr on a static method!");
342   return EmitCXXMemberOrOperatorMemberCallExpr(
343       E, MD, ReturnValue, /*HasQualifier=*/false, /*Qualifier=*/nullptr,
344       /*IsArrow=*/false, E->getArg(0));
345 }
346 
EmitCUDAKernelCallExpr(const CUDAKernelCallExpr * E,ReturnValueSlot ReturnValue)347 RValue CodeGenFunction::EmitCUDAKernelCallExpr(const CUDAKernelCallExpr *E,
348                                                ReturnValueSlot ReturnValue) {
349   return CGM.getCUDARuntime().EmitCUDAKernelCallExpr(*this, E, ReturnValue);
350 }
351 
EmitNullBaseClassInitialization(CodeGenFunction & CGF,Address DestPtr,const CXXRecordDecl * Base)352 static void EmitNullBaseClassInitialization(CodeGenFunction &CGF,
353                                             Address DestPtr,
354                                             const CXXRecordDecl *Base) {
355   if (Base->isEmpty())
356     return;
357 
358   DestPtr = CGF.Builder.CreateElementBitCast(DestPtr, CGF.Int8Ty);
359 
360   const ASTRecordLayout &Layout = CGF.getContext().getASTRecordLayout(Base);
361   CharUnits NVSize = Layout.getNonVirtualSize();
362 
363   // We cannot simply zero-initialize the entire base sub-object if vbptrs are
364   // present, they are initialized by the most derived class before calling the
365   // constructor.
366   SmallVector<std::pair<CharUnits, CharUnits>, 1> Stores;
367   Stores.emplace_back(CharUnits::Zero(), NVSize);
368 
369   // Each store is split by the existence of a vbptr.
370   CharUnits VBPtrWidth = CGF.getPointerSize();
371   std::vector<CharUnits> VBPtrOffsets =
372       CGF.CGM.getCXXABI().getVBPtrOffsets(Base);
373   for (CharUnits VBPtrOffset : VBPtrOffsets) {
374     // Stop before we hit any virtual base pointers located in virtual bases.
375     if (VBPtrOffset >= NVSize)
376       break;
377     std::pair<CharUnits, CharUnits> LastStore = Stores.pop_back_val();
378     CharUnits LastStoreOffset = LastStore.first;
379     CharUnits LastStoreSize = LastStore.second;
380 
381     CharUnits SplitBeforeOffset = LastStoreOffset;
382     CharUnits SplitBeforeSize = VBPtrOffset - SplitBeforeOffset;
383     assert(!SplitBeforeSize.isNegative() && "negative store size!");
384     if (!SplitBeforeSize.isZero())
385       Stores.emplace_back(SplitBeforeOffset, SplitBeforeSize);
386 
387     CharUnits SplitAfterOffset = VBPtrOffset + VBPtrWidth;
388     CharUnits SplitAfterSize = LastStoreSize - SplitAfterOffset;
389     assert(!SplitAfterSize.isNegative() && "negative store size!");
390     if (!SplitAfterSize.isZero())
391       Stores.emplace_back(SplitAfterOffset, SplitAfterSize);
392   }
393 
394   // If the type contains a pointer to data member we can't memset it to zero.
395   // Instead, create a null constant and copy it to the destination.
396   // TODO: there are other patterns besides zero that we can usefully memset,
397   // like -1, which happens to be the pattern used by member-pointers.
398   // TODO: isZeroInitializable can be over-conservative in the case where a
399   // virtual base contains a member pointer.
400   llvm::Constant *NullConstantForBase = CGF.CGM.EmitNullConstantForBase(Base);
401   if (!NullConstantForBase->isNullValue()) {
402     llvm::GlobalVariable *NullVariable = new llvm::GlobalVariable(
403         CGF.CGM.getModule(), NullConstantForBase->getType(),
404         /*isConstant=*/true, llvm::GlobalVariable::PrivateLinkage,
405         NullConstantForBase, Twine());
406 
407     CharUnits Align = std::max(Layout.getNonVirtualAlignment(),
408                                DestPtr.getAlignment());
409     NullVariable->setAlignment(Align.getQuantity());
410 
411     Address SrcPtr = Address(CGF.EmitCastToVoidPtr(NullVariable), Align);
412 
413     // Get and call the appropriate llvm.memcpy overload.
414     for (std::pair<CharUnits, CharUnits> Store : Stores) {
415       CharUnits StoreOffset = Store.first;
416       CharUnits StoreSize = Store.second;
417       llvm::Value *StoreSizeVal = CGF.CGM.getSize(StoreSize);
418       CGF.Builder.CreateMemCpy(
419           CGF.Builder.CreateConstInBoundsByteGEP(DestPtr, StoreOffset),
420           CGF.Builder.CreateConstInBoundsByteGEP(SrcPtr, StoreOffset),
421           StoreSizeVal);
422     }
423 
424   // Otherwise, just memset the whole thing to zero.  This is legal
425   // because in LLVM, all default initializers (other than the ones we just
426   // handled above) are guaranteed to have a bit pattern of all zeros.
427   } else {
428     for (std::pair<CharUnits, CharUnits> Store : Stores) {
429       CharUnits StoreOffset = Store.first;
430       CharUnits StoreSize = Store.second;
431       llvm::Value *StoreSizeVal = CGF.CGM.getSize(StoreSize);
432       CGF.Builder.CreateMemSet(
433           CGF.Builder.CreateConstInBoundsByteGEP(DestPtr, StoreOffset),
434           CGF.Builder.getInt8(0), StoreSizeVal);
435     }
436   }
437 }
438 
439 void
EmitCXXConstructExpr(const CXXConstructExpr * E,AggValueSlot Dest)440 CodeGenFunction::EmitCXXConstructExpr(const CXXConstructExpr *E,
441                                       AggValueSlot Dest) {
442   assert(!Dest.isIgnored() && "Must have a destination!");
443   const CXXConstructorDecl *CD = E->getConstructor();
444 
445   // If we require zero initialization before (or instead of) calling the
446   // constructor, as can be the case with a non-user-provided default
447   // constructor, emit the zero initialization now, unless destination is
448   // already zeroed.
449   if (E->requiresZeroInitialization() && !Dest.isZeroed()) {
450     switch (E->getConstructionKind()) {
451     case CXXConstructExpr::CK_Delegating:
452     case CXXConstructExpr::CK_Complete:
453       EmitNullInitialization(Dest.getAddress(), E->getType());
454       break;
455     case CXXConstructExpr::CK_VirtualBase:
456     case CXXConstructExpr::CK_NonVirtualBase:
457       EmitNullBaseClassInitialization(*this, Dest.getAddress(),
458                                       CD->getParent());
459       break;
460     }
461   }
462 
463   // If this is a call to a trivial default constructor, do nothing.
464   if (CD->isTrivial() && CD->isDefaultConstructor())
465     return;
466 
467   // Elide the constructor if we're constructing from a temporary.
468   // The temporary check is required because Sema sets this on NRVO
469   // returns.
470   if (getLangOpts().ElideConstructors && E->isElidable()) {
471     assert(getContext().hasSameUnqualifiedType(E->getType(),
472                                                E->getArg(0)->getType()));
473     if (E->getArg(0)->isTemporaryObject(getContext(), CD->getParent())) {
474       EmitAggExpr(E->getArg(0), Dest);
475       return;
476     }
477   }
478 
479   if (const ArrayType *arrayType
480         = getContext().getAsArrayType(E->getType())) {
481     EmitCXXAggrConstructorCall(CD, arrayType, Dest.getAddress(), E);
482   } else {
483     CXXCtorType Type = Ctor_Complete;
484     bool ForVirtualBase = false;
485     bool Delegating = false;
486 
487     switch (E->getConstructionKind()) {
488      case CXXConstructExpr::CK_Delegating:
489       // We should be emitting a constructor; GlobalDecl will assert this
490       Type = CurGD.getCtorType();
491       Delegating = true;
492       break;
493 
494      case CXXConstructExpr::CK_Complete:
495       Type = Ctor_Complete;
496       break;
497 
498      case CXXConstructExpr::CK_VirtualBase:
499       ForVirtualBase = true;
500       // fall-through
501 
502      case CXXConstructExpr::CK_NonVirtualBase:
503       Type = Ctor_Base;
504     }
505 
506     // Call the constructor.
507     EmitCXXConstructorCall(CD, Type, ForVirtualBase, Delegating,
508                            Dest.getAddress(), E);
509   }
510 }
511 
EmitSynthesizedCXXCopyCtor(Address Dest,Address Src,const Expr * Exp)512 void CodeGenFunction::EmitSynthesizedCXXCopyCtor(Address Dest, Address Src,
513                                                  const Expr *Exp) {
514   if (const ExprWithCleanups *E = dyn_cast<ExprWithCleanups>(Exp))
515     Exp = E->getSubExpr();
516   assert(isa<CXXConstructExpr>(Exp) &&
517          "EmitSynthesizedCXXCopyCtor - unknown copy ctor expr");
518   const CXXConstructExpr* E = cast<CXXConstructExpr>(Exp);
519   const CXXConstructorDecl *CD = E->getConstructor();
520   RunCleanupsScope Scope(*this);
521 
522   // If we require zero initialization before (or instead of) calling the
523   // constructor, as can be the case with a non-user-provided default
524   // constructor, emit the zero initialization now.
525   // FIXME. Do I still need this for a copy ctor synthesis?
526   if (E->requiresZeroInitialization())
527     EmitNullInitialization(Dest, E->getType());
528 
529   assert(!getContext().getAsConstantArrayType(E->getType())
530          && "EmitSynthesizedCXXCopyCtor - Copied-in Array");
531   EmitSynthesizedCXXCopyCtorCall(CD, Dest, Src, E);
532 }
533 
CalculateCookiePadding(CodeGenFunction & CGF,const CXXNewExpr * E)534 static CharUnits CalculateCookiePadding(CodeGenFunction &CGF,
535                                         const CXXNewExpr *E) {
536   if (!E->isArray())
537     return CharUnits::Zero();
538 
539   // No cookie is required if the operator new[] being used is the
540   // reserved placement operator new[].
541   if (E->getOperatorNew()->isReservedGlobalPlacementOperator())
542     return CharUnits::Zero();
543 
544   return CGF.CGM.getCXXABI().GetArrayCookieSize(E);
545 }
546 
EmitCXXNewAllocSize(CodeGenFunction & CGF,const CXXNewExpr * e,unsigned minElements,llvm::Value * & numElements,llvm::Value * & sizeWithoutCookie)547 static llvm::Value *EmitCXXNewAllocSize(CodeGenFunction &CGF,
548                                         const CXXNewExpr *e,
549                                         unsigned minElements,
550                                         llvm::Value *&numElements,
551                                         llvm::Value *&sizeWithoutCookie) {
552   QualType type = e->getAllocatedType();
553 
554   if (!e->isArray()) {
555     CharUnits typeSize = CGF.getContext().getTypeSizeInChars(type);
556     sizeWithoutCookie
557       = llvm::ConstantInt::get(CGF.SizeTy, typeSize.getQuantity());
558     return sizeWithoutCookie;
559   }
560 
561   // The width of size_t.
562   unsigned sizeWidth = CGF.SizeTy->getBitWidth();
563 
564   // Figure out the cookie size.
565   llvm::APInt cookieSize(sizeWidth,
566                          CalculateCookiePadding(CGF, e).getQuantity());
567 
568   // Emit the array size expression.
569   // We multiply the size of all dimensions for NumElements.
570   // e.g for 'int[2][3]', ElemType is 'int' and NumElements is 6.
571   numElements = CGF.EmitScalarExpr(e->getArraySize());
572   assert(isa<llvm::IntegerType>(numElements->getType()));
573 
574   // The number of elements can be have an arbitrary integer type;
575   // essentially, we need to multiply it by a constant factor, add a
576   // cookie size, and verify that the result is representable as a
577   // size_t.  That's just a gloss, though, and it's wrong in one
578   // important way: if the count is negative, it's an error even if
579   // the cookie size would bring the total size >= 0.
580   bool isSigned
581     = e->getArraySize()->getType()->isSignedIntegerOrEnumerationType();
582   llvm::IntegerType *numElementsType
583     = cast<llvm::IntegerType>(numElements->getType());
584   unsigned numElementsWidth = numElementsType->getBitWidth();
585 
586   // Compute the constant factor.
587   llvm::APInt arraySizeMultiplier(sizeWidth, 1);
588   while (const ConstantArrayType *CAT
589              = CGF.getContext().getAsConstantArrayType(type)) {
590     type = CAT->getElementType();
591     arraySizeMultiplier *= CAT->getSize();
592   }
593 
594   CharUnits typeSize = CGF.getContext().getTypeSizeInChars(type);
595   llvm::APInt typeSizeMultiplier(sizeWidth, typeSize.getQuantity());
596   typeSizeMultiplier *= arraySizeMultiplier;
597 
598   // This will be a size_t.
599   llvm::Value *size;
600 
601   // If someone is doing 'new int[42]' there is no need to do a dynamic check.
602   // Don't bloat the -O0 code.
603   if (llvm::ConstantInt *numElementsC =
604         dyn_cast<llvm::ConstantInt>(numElements)) {
605     const llvm::APInt &count = numElementsC->getValue();
606 
607     bool hasAnyOverflow = false;
608 
609     // If 'count' was a negative number, it's an overflow.
610     if (isSigned && count.isNegative())
611       hasAnyOverflow = true;
612 
613     // We want to do all this arithmetic in size_t.  If numElements is
614     // wider than that, check whether it's already too big, and if so,
615     // overflow.
616     else if (numElementsWidth > sizeWidth &&
617              numElementsWidth - sizeWidth > count.countLeadingZeros())
618       hasAnyOverflow = true;
619 
620     // Okay, compute a count at the right width.
621     llvm::APInt adjustedCount = count.zextOrTrunc(sizeWidth);
622 
623     // If there is a brace-initializer, we cannot allocate fewer elements than
624     // there are initializers. If we do, that's treated like an overflow.
625     if (adjustedCount.ult(minElements))
626       hasAnyOverflow = true;
627 
628     // Scale numElements by that.  This might overflow, but we don't
629     // care because it only overflows if allocationSize does, too, and
630     // if that overflows then we shouldn't use this.
631     numElements = llvm::ConstantInt::get(CGF.SizeTy,
632                                          adjustedCount * arraySizeMultiplier);
633 
634     // Compute the size before cookie, and track whether it overflowed.
635     bool overflow;
636     llvm::APInt allocationSize
637       = adjustedCount.umul_ov(typeSizeMultiplier, overflow);
638     hasAnyOverflow |= overflow;
639 
640     // Add in the cookie, and check whether it's overflowed.
641     if (cookieSize != 0) {
642       // Save the current size without a cookie.  This shouldn't be
643       // used if there was overflow.
644       sizeWithoutCookie = llvm::ConstantInt::get(CGF.SizeTy, allocationSize);
645 
646       allocationSize = allocationSize.uadd_ov(cookieSize, overflow);
647       hasAnyOverflow |= overflow;
648     }
649 
650     // On overflow, produce a -1 so operator new will fail.
651     if (hasAnyOverflow) {
652       size = llvm::Constant::getAllOnesValue(CGF.SizeTy);
653     } else {
654       size = llvm::ConstantInt::get(CGF.SizeTy, allocationSize);
655     }
656 
657   // Otherwise, we might need to use the overflow intrinsics.
658   } else {
659     // There are up to five conditions we need to test for:
660     // 1) if isSigned, we need to check whether numElements is negative;
661     // 2) if numElementsWidth > sizeWidth, we need to check whether
662     //   numElements is larger than something representable in size_t;
663     // 3) if minElements > 0, we need to check whether numElements is smaller
664     //    than that.
665     // 4) we need to compute
666     //      sizeWithoutCookie := numElements * typeSizeMultiplier
667     //    and check whether it overflows; and
668     // 5) if we need a cookie, we need to compute
669     //      size := sizeWithoutCookie + cookieSize
670     //    and check whether it overflows.
671 
672     llvm::Value *hasOverflow = nullptr;
673 
674     // If numElementsWidth > sizeWidth, then one way or another, we're
675     // going to have to do a comparison for (2), and this happens to
676     // take care of (1), too.
677     if (numElementsWidth > sizeWidth) {
678       llvm::APInt threshold(numElementsWidth, 1);
679       threshold <<= sizeWidth;
680 
681       llvm::Value *thresholdV
682         = llvm::ConstantInt::get(numElementsType, threshold);
683 
684       hasOverflow = CGF.Builder.CreateICmpUGE(numElements, thresholdV);
685       numElements = CGF.Builder.CreateTrunc(numElements, CGF.SizeTy);
686 
687     // Otherwise, if we're signed, we want to sext up to size_t.
688     } else if (isSigned) {
689       if (numElementsWidth < sizeWidth)
690         numElements = CGF.Builder.CreateSExt(numElements, CGF.SizeTy);
691 
692       // If there's a non-1 type size multiplier, then we can do the
693       // signedness check at the same time as we do the multiply
694       // because a negative number times anything will cause an
695       // unsigned overflow.  Otherwise, we have to do it here. But at least
696       // in this case, we can subsume the >= minElements check.
697       if (typeSizeMultiplier == 1)
698         hasOverflow = CGF.Builder.CreateICmpSLT(numElements,
699                               llvm::ConstantInt::get(CGF.SizeTy, minElements));
700 
701     // Otherwise, zext up to size_t if necessary.
702     } else if (numElementsWidth < sizeWidth) {
703       numElements = CGF.Builder.CreateZExt(numElements, CGF.SizeTy);
704     }
705 
706     assert(numElements->getType() == CGF.SizeTy);
707 
708     if (minElements) {
709       // Don't allow allocation of fewer elements than we have initializers.
710       if (!hasOverflow) {
711         hasOverflow = CGF.Builder.CreateICmpULT(numElements,
712                               llvm::ConstantInt::get(CGF.SizeTy, minElements));
713       } else if (numElementsWidth > sizeWidth) {
714         // The other existing overflow subsumes this check.
715         // We do an unsigned comparison, since any signed value < -1 is
716         // taken care of either above or below.
717         hasOverflow = CGF.Builder.CreateOr(hasOverflow,
718                           CGF.Builder.CreateICmpULT(numElements,
719                               llvm::ConstantInt::get(CGF.SizeTy, minElements)));
720       }
721     }
722 
723     size = numElements;
724 
725     // Multiply by the type size if necessary.  This multiplier
726     // includes all the factors for nested arrays.
727     //
728     // This step also causes numElements to be scaled up by the
729     // nested-array factor if necessary.  Overflow on this computation
730     // can be ignored because the result shouldn't be used if
731     // allocation fails.
732     if (typeSizeMultiplier != 1) {
733       llvm::Value *umul_with_overflow
734         = CGF.CGM.getIntrinsic(llvm::Intrinsic::umul_with_overflow, CGF.SizeTy);
735 
736       llvm::Value *tsmV =
737         llvm::ConstantInt::get(CGF.SizeTy, typeSizeMultiplier);
738       llvm::Value *result =
739           CGF.Builder.CreateCall(umul_with_overflow, {size, tsmV});
740 
741       llvm::Value *overflowed = CGF.Builder.CreateExtractValue(result, 1);
742       if (hasOverflow)
743         hasOverflow = CGF.Builder.CreateOr(hasOverflow, overflowed);
744       else
745         hasOverflow = overflowed;
746 
747       size = CGF.Builder.CreateExtractValue(result, 0);
748 
749       // Also scale up numElements by the array size multiplier.
750       if (arraySizeMultiplier != 1) {
751         // If the base element type size is 1, then we can re-use the
752         // multiply we just did.
753         if (typeSize.isOne()) {
754           assert(arraySizeMultiplier == typeSizeMultiplier);
755           numElements = size;
756 
757         // Otherwise we need a separate multiply.
758         } else {
759           llvm::Value *asmV =
760             llvm::ConstantInt::get(CGF.SizeTy, arraySizeMultiplier);
761           numElements = CGF.Builder.CreateMul(numElements, asmV);
762         }
763       }
764     } else {
765       // numElements doesn't need to be scaled.
766       assert(arraySizeMultiplier == 1);
767     }
768 
769     // Add in the cookie size if necessary.
770     if (cookieSize != 0) {
771       sizeWithoutCookie = size;
772 
773       llvm::Value *uadd_with_overflow
774         = CGF.CGM.getIntrinsic(llvm::Intrinsic::uadd_with_overflow, CGF.SizeTy);
775 
776       llvm::Value *cookieSizeV = llvm::ConstantInt::get(CGF.SizeTy, cookieSize);
777       llvm::Value *result =
778           CGF.Builder.CreateCall(uadd_with_overflow, {size, cookieSizeV});
779 
780       llvm::Value *overflowed = CGF.Builder.CreateExtractValue(result, 1);
781       if (hasOverflow)
782         hasOverflow = CGF.Builder.CreateOr(hasOverflow, overflowed);
783       else
784         hasOverflow = overflowed;
785 
786       size = CGF.Builder.CreateExtractValue(result, 0);
787     }
788 
789     // If we had any possibility of dynamic overflow, make a select to
790     // overwrite 'size' with an all-ones value, which should cause
791     // operator new to throw.
792     if (hasOverflow)
793       size = CGF.Builder.CreateSelect(hasOverflow,
794                                  llvm::Constant::getAllOnesValue(CGF.SizeTy),
795                                       size);
796   }
797 
798   if (cookieSize == 0)
799     sizeWithoutCookie = size;
800   else
801     assert(sizeWithoutCookie && "didn't set sizeWithoutCookie?");
802 
803   return size;
804 }
805 
StoreAnyExprIntoOneUnit(CodeGenFunction & CGF,const Expr * Init,QualType AllocType,Address NewPtr)806 static void StoreAnyExprIntoOneUnit(CodeGenFunction &CGF, const Expr *Init,
807                                     QualType AllocType, Address NewPtr) {
808   // FIXME: Refactor with EmitExprAsInit.
809   switch (CGF.getEvaluationKind(AllocType)) {
810   case TEK_Scalar:
811     CGF.EmitScalarInit(Init, nullptr,
812                        CGF.MakeAddrLValue(NewPtr, AllocType), false);
813     return;
814   case TEK_Complex:
815     CGF.EmitComplexExprIntoLValue(Init, CGF.MakeAddrLValue(NewPtr, AllocType),
816                                   /*isInit*/ true);
817     return;
818   case TEK_Aggregate: {
819     AggValueSlot Slot
820       = AggValueSlot::forAddr(NewPtr, AllocType.getQualifiers(),
821                               AggValueSlot::IsDestructed,
822                               AggValueSlot::DoesNotNeedGCBarriers,
823                               AggValueSlot::IsNotAliased);
824     CGF.EmitAggExpr(Init, Slot);
825     return;
826   }
827   }
828   llvm_unreachable("bad evaluation kind");
829 }
830 
EmitNewArrayInitializer(const CXXNewExpr * E,QualType ElementType,llvm::Type * ElementTy,Address BeginPtr,llvm::Value * NumElements,llvm::Value * AllocSizeWithoutCookie)831 void CodeGenFunction::EmitNewArrayInitializer(
832     const CXXNewExpr *E, QualType ElementType, llvm::Type *ElementTy,
833     Address BeginPtr, llvm::Value *NumElements,
834     llvm::Value *AllocSizeWithoutCookie) {
835   // If we have a type with trivial initialization and no initializer,
836   // there's nothing to do.
837   if (!E->hasInitializer())
838     return;
839 
840   Address CurPtr = BeginPtr;
841 
842   unsigned InitListElements = 0;
843 
844   const Expr *Init = E->getInitializer();
845   Address EndOfInit = Address::invalid();
846   QualType::DestructionKind DtorKind = ElementType.isDestructedType();
847   EHScopeStack::stable_iterator Cleanup;
848   llvm::Instruction *CleanupDominator = nullptr;
849 
850   CharUnits ElementSize = getContext().getTypeSizeInChars(ElementType);
851   CharUnits ElementAlign =
852     BeginPtr.getAlignment().alignmentOfArrayElement(ElementSize);
853 
854   // If the initializer is an initializer list, first do the explicit elements.
855   if (const InitListExpr *ILE = dyn_cast<InitListExpr>(Init)) {
856     InitListElements = ILE->getNumInits();
857 
858     // If this is a multi-dimensional array new, we will initialize multiple
859     // elements with each init list element.
860     QualType AllocType = E->getAllocatedType();
861     if (const ConstantArrayType *CAT = dyn_cast_or_null<ConstantArrayType>(
862             AllocType->getAsArrayTypeUnsafe())) {
863       ElementTy = ConvertTypeForMem(AllocType);
864       CurPtr = Builder.CreateElementBitCast(CurPtr, ElementTy);
865       InitListElements *= getContext().getConstantArrayElementCount(CAT);
866     }
867 
868     // Enter a partial-destruction Cleanup if necessary.
869     if (needsEHCleanup(DtorKind)) {
870       // In principle we could tell the Cleanup where we are more
871       // directly, but the control flow can get so varied here that it
872       // would actually be quite complex.  Therefore we go through an
873       // alloca.
874       EndOfInit = CreateTempAlloca(BeginPtr.getType(), getPointerAlign(),
875                                    "array.init.end");
876       CleanupDominator = Builder.CreateStore(BeginPtr.getPointer(), EndOfInit);
877       pushIrregularPartialArrayCleanup(BeginPtr.getPointer(), EndOfInit,
878                                        ElementType, ElementAlign,
879                                        getDestroyer(DtorKind));
880       Cleanup = EHStack.stable_begin();
881     }
882 
883     CharUnits StartAlign = CurPtr.getAlignment();
884     for (unsigned i = 0, e = ILE->getNumInits(); i != e; ++i) {
885       // Tell the cleanup that it needs to destroy up to this
886       // element.  TODO: some of these stores can be trivially
887       // observed to be unnecessary.
888       if (EndOfInit.isValid()) {
889         auto FinishedPtr =
890           Builder.CreateBitCast(CurPtr.getPointer(), BeginPtr.getType());
891         Builder.CreateStore(FinishedPtr, EndOfInit);
892       }
893       // FIXME: If the last initializer is an incomplete initializer list for
894       // an array, and we have an array filler, we can fold together the two
895       // initialization loops.
896       StoreAnyExprIntoOneUnit(*this, ILE->getInit(i),
897                               ILE->getInit(i)->getType(), CurPtr);
898       CurPtr = Address(Builder.CreateInBoundsGEP(CurPtr.getPointer(),
899                                                  Builder.getSize(1),
900                                                  "array.exp.next"),
901                        StartAlign.alignmentAtOffset((i + 1) * ElementSize));
902     }
903 
904     // The remaining elements are filled with the array filler expression.
905     Init = ILE->getArrayFiller();
906 
907     // Extract the initializer for the individual array elements by pulling
908     // out the array filler from all the nested initializer lists. This avoids
909     // generating a nested loop for the initialization.
910     while (Init && Init->getType()->isConstantArrayType()) {
911       auto *SubILE = dyn_cast<InitListExpr>(Init);
912       if (!SubILE)
913         break;
914       assert(SubILE->getNumInits() == 0 && "explicit inits in array filler?");
915       Init = SubILE->getArrayFiller();
916     }
917 
918     // Switch back to initializing one base element at a time.
919     CurPtr = Builder.CreateBitCast(CurPtr, BeginPtr.getType());
920   }
921 
922   // Attempt to perform zero-initialization using memset.
923   auto TryMemsetInitialization = [&]() -> bool {
924     // FIXME: If the type is a pointer-to-data-member under the Itanium ABI,
925     // we can initialize with a memset to -1.
926     if (!CGM.getTypes().isZeroInitializable(ElementType))
927       return false;
928 
929     // Optimization: since zero initialization will just set the memory
930     // to all zeroes, generate a single memset to do it in one shot.
931 
932     // Subtract out the size of any elements we've already initialized.
933     auto *RemainingSize = AllocSizeWithoutCookie;
934     if (InitListElements) {
935       // We know this can't overflow; we check this when doing the allocation.
936       auto *InitializedSize = llvm::ConstantInt::get(
937           RemainingSize->getType(),
938           getContext().getTypeSizeInChars(ElementType).getQuantity() *
939               InitListElements);
940       RemainingSize = Builder.CreateSub(RemainingSize, InitializedSize);
941     }
942 
943     // Create the memset.
944     Builder.CreateMemSet(CurPtr, Builder.getInt8(0), RemainingSize, false);
945     return true;
946   };
947 
948   // If all elements have already been initialized, skip any further
949   // initialization.
950   llvm::ConstantInt *ConstNum = dyn_cast<llvm::ConstantInt>(NumElements);
951   if (ConstNum && ConstNum->getZExtValue() <= InitListElements) {
952     // If there was a Cleanup, deactivate it.
953     if (CleanupDominator)
954       DeactivateCleanupBlock(Cleanup, CleanupDominator);
955     return;
956   }
957 
958   assert(Init && "have trailing elements to initialize but no initializer");
959 
960   // If this is a constructor call, try to optimize it out, and failing that
961   // emit a single loop to initialize all remaining elements.
962   if (const CXXConstructExpr *CCE = dyn_cast<CXXConstructExpr>(Init)) {
963     CXXConstructorDecl *Ctor = CCE->getConstructor();
964     if (Ctor->isTrivial()) {
965       // If new expression did not specify value-initialization, then there
966       // is no initialization.
967       if (!CCE->requiresZeroInitialization() || Ctor->getParent()->isEmpty())
968         return;
969 
970       if (TryMemsetInitialization())
971         return;
972     }
973 
974     // Store the new Cleanup position for irregular Cleanups.
975     //
976     // FIXME: Share this cleanup with the constructor call emission rather than
977     // having it create a cleanup of its own.
978     if (EndOfInit.isValid())
979       Builder.CreateStore(CurPtr.getPointer(), EndOfInit);
980 
981     // Emit a constructor call loop to initialize the remaining elements.
982     if (InitListElements)
983       NumElements = Builder.CreateSub(
984           NumElements,
985           llvm::ConstantInt::get(NumElements->getType(), InitListElements));
986     EmitCXXAggrConstructorCall(Ctor, NumElements, CurPtr, CCE,
987                                CCE->requiresZeroInitialization());
988     return;
989   }
990 
991   // If this is value-initialization, we can usually use memset.
992   ImplicitValueInitExpr IVIE(ElementType);
993   if (isa<ImplicitValueInitExpr>(Init)) {
994     if (TryMemsetInitialization())
995       return;
996 
997     // Switch to an ImplicitValueInitExpr for the element type. This handles
998     // only one case: multidimensional array new of pointers to members. In
999     // all other cases, we already have an initializer for the array element.
1000     Init = &IVIE;
1001   }
1002 
1003   // At this point we should have found an initializer for the individual
1004   // elements of the array.
1005   assert(getContext().hasSameUnqualifiedType(ElementType, Init->getType()) &&
1006          "got wrong type of element to initialize");
1007 
1008   // If we have an empty initializer list, we can usually use memset.
1009   if (auto *ILE = dyn_cast<InitListExpr>(Init))
1010     if (ILE->getNumInits() == 0 && TryMemsetInitialization())
1011       return;
1012 
1013   // If we have a struct whose every field is value-initialized, we can
1014   // usually use memset.
1015   if (auto *ILE = dyn_cast<InitListExpr>(Init)) {
1016     if (const RecordType *RType = ILE->getType()->getAs<RecordType>()) {
1017       if (RType->getDecl()->isStruct()) {
1018         unsigned NumElements = 0;
1019         if (auto *CXXRD = dyn_cast<CXXRecordDecl>(RType->getDecl()))
1020           NumElements = CXXRD->getNumBases();
1021         for (auto *Field : RType->getDecl()->fields())
1022           if (!Field->isUnnamedBitfield())
1023             ++NumElements;
1024         // FIXME: Recurse into nested InitListExprs.
1025         if (ILE->getNumInits() == NumElements)
1026           for (unsigned i = 0, e = ILE->getNumInits(); i != e; ++i)
1027             if (!isa<ImplicitValueInitExpr>(ILE->getInit(i)))
1028               --NumElements;
1029         if (ILE->getNumInits() == NumElements && TryMemsetInitialization())
1030           return;
1031       }
1032     }
1033   }
1034 
1035   // Create the loop blocks.
1036   llvm::BasicBlock *EntryBB = Builder.GetInsertBlock();
1037   llvm::BasicBlock *LoopBB = createBasicBlock("new.loop");
1038   llvm::BasicBlock *ContBB = createBasicBlock("new.loop.end");
1039 
1040   // Find the end of the array, hoisted out of the loop.
1041   llvm::Value *EndPtr =
1042     Builder.CreateInBoundsGEP(BeginPtr.getPointer(), NumElements, "array.end");
1043 
1044   // If the number of elements isn't constant, we have to now check if there is
1045   // anything left to initialize.
1046   if (!ConstNum) {
1047     llvm::Value *IsEmpty =
1048       Builder.CreateICmpEQ(CurPtr.getPointer(), EndPtr, "array.isempty");
1049     Builder.CreateCondBr(IsEmpty, ContBB, LoopBB);
1050   }
1051 
1052   // Enter the loop.
1053   EmitBlock(LoopBB);
1054 
1055   // Set up the current-element phi.
1056   llvm::PHINode *CurPtrPhi =
1057     Builder.CreatePHI(CurPtr.getType(), 2, "array.cur");
1058   CurPtrPhi->addIncoming(CurPtr.getPointer(), EntryBB);
1059 
1060   CurPtr = Address(CurPtrPhi, ElementAlign);
1061 
1062   // Store the new Cleanup position for irregular Cleanups.
1063   if (EndOfInit.isValid())
1064     Builder.CreateStore(CurPtr.getPointer(), EndOfInit);
1065 
1066   // Enter a partial-destruction Cleanup if necessary.
1067   if (!CleanupDominator && needsEHCleanup(DtorKind)) {
1068     pushRegularPartialArrayCleanup(BeginPtr.getPointer(), CurPtr.getPointer(),
1069                                    ElementType, ElementAlign,
1070                                    getDestroyer(DtorKind));
1071     Cleanup = EHStack.stable_begin();
1072     CleanupDominator = Builder.CreateUnreachable();
1073   }
1074 
1075   // Emit the initializer into this element.
1076   StoreAnyExprIntoOneUnit(*this, Init, Init->getType(), CurPtr);
1077 
1078   // Leave the Cleanup if we entered one.
1079   if (CleanupDominator) {
1080     DeactivateCleanupBlock(Cleanup, CleanupDominator);
1081     CleanupDominator->eraseFromParent();
1082   }
1083 
1084   // Advance to the next element by adjusting the pointer type as necessary.
1085   llvm::Value *NextPtr =
1086     Builder.CreateConstInBoundsGEP1_32(ElementTy, CurPtr.getPointer(), 1,
1087                                        "array.next");
1088 
1089   // Check whether we've gotten to the end of the array and, if so,
1090   // exit the loop.
1091   llvm::Value *IsEnd = Builder.CreateICmpEQ(NextPtr, EndPtr, "array.atend");
1092   Builder.CreateCondBr(IsEnd, ContBB, LoopBB);
1093   CurPtrPhi->addIncoming(NextPtr, Builder.GetInsertBlock());
1094 
1095   EmitBlock(ContBB);
1096 }
1097 
EmitNewInitializer(CodeGenFunction & CGF,const CXXNewExpr * E,QualType ElementType,llvm::Type * ElementTy,Address NewPtr,llvm::Value * NumElements,llvm::Value * AllocSizeWithoutCookie)1098 static void EmitNewInitializer(CodeGenFunction &CGF, const CXXNewExpr *E,
1099                                QualType ElementType, llvm::Type *ElementTy,
1100                                Address NewPtr, llvm::Value *NumElements,
1101                                llvm::Value *AllocSizeWithoutCookie) {
1102   ApplyDebugLocation DL(CGF, E);
1103   if (E->isArray())
1104     CGF.EmitNewArrayInitializer(E, ElementType, ElementTy, NewPtr, NumElements,
1105                                 AllocSizeWithoutCookie);
1106   else if (const Expr *Init = E->getInitializer())
1107     StoreAnyExprIntoOneUnit(CGF, Init, E->getAllocatedType(), NewPtr);
1108 }
1109 
1110 /// Emit a call to an operator new or operator delete function, as implicitly
1111 /// created by new-expressions and delete-expressions.
EmitNewDeleteCall(CodeGenFunction & CGF,const FunctionDecl * Callee,const FunctionProtoType * CalleeType,const CallArgList & Args)1112 static RValue EmitNewDeleteCall(CodeGenFunction &CGF,
1113                                 const FunctionDecl *Callee,
1114                                 const FunctionProtoType *CalleeType,
1115                                 const CallArgList &Args) {
1116   llvm::Instruction *CallOrInvoke;
1117   llvm::Value *CalleeAddr = CGF.CGM.GetAddrOfFunction(Callee);
1118   RValue RV =
1119       CGF.EmitCall(CGF.CGM.getTypes().arrangeFreeFunctionCall(
1120                        Args, CalleeType, /*chainCall=*/false),
1121                    CalleeAddr, ReturnValueSlot(), Args, Callee, &CallOrInvoke);
1122 
1123   /// C++1y [expr.new]p10:
1124   ///   [In a new-expression,] an implementation is allowed to omit a call
1125   ///   to a replaceable global allocation function.
1126   ///
1127   /// We model such elidable calls with the 'builtin' attribute.
1128   llvm::Function *Fn = dyn_cast<llvm::Function>(CalleeAddr);
1129   if (Callee->isReplaceableGlobalAllocationFunction() &&
1130       Fn && Fn->hasFnAttribute(llvm::Attribute::NoBuiltin)) {
1131     // FIXME: Add addAttribute to CallSite.
1132     if (llvm::CallInst *CI = dyn_cast<llvm::CallInst>(CallOrInvoke))
1133       CI->addAttribute(llvm::AttributeSet::FunctionIndex,
1134                        llvm::Attribute::Builtin);
1135     else if (llvm::InvokeInst *II = dyn_cast<llvm::InvokeInst>(CallOrInvoke))
1136       II->addAttribute(llvm::AttributeSet::FunctionIndex,
1137                        llvm::Attribute::Builtin);
1138     else
1139       llvm_unreachable("unexpected kind of call instruction");
1140   }
1141 
1142   return RV;
1143 }
1144 
EmitBuiltinNewDeleteCall(const FunctionProtoType * Type,const Expr * Arg,bool IsDelete)1145 RValue CodeGenFunction::EmitBuiltinNewDeleteCall(const FunctionProtoType *Type,
1146                                                  const Expr *Arg,
1147                                                  bool IsDelete) {
1148   CallArgList Args;
1149   const Stmt *ArgS = Arg;
1150   EmitCallArgs(Args, *Type->param_type_begin(), llvm::makeArrayRef(ArgS));
1151   // Find the allocation or deallocation function that we're calling.
1152   ASTContext &Ctx = getContext();
1153   DeclarationName Name = Ctx.DeclarationNames
1154       .getCXXOperatorName(IsDelete ? OO_Delete : OO_New);
1155   for (auto *Decl : Ctx.getTranslationUnitDecl()->lookup(Name))
1156     if (auto *FD = dyn_cast<FunctionDecl>(Decl))
1157       if (Ctx.hasSameType(FD->getType(), QualType(Type, 0)))
1158         return EmitNewDeleteCall(*this, cast<FunctionDecl>(Decl), Type, Args);
1159   llvm_unreachable("predeclared global operator new/delete is missing");
1160 }
1161 
1162 namespace {
1163   /// A cleanup to call the given 'operator delete' function upon
1164   /// abnormal exit from a new expression.
1165   class CallDeleteDuringNew final : public EHScopeStack::Cleanup {
1166     size_t NumPlacementArgs;
1167     const FunctionDecl *OperatorDelete;
1168     llvm::Value *Ptr;
1169     llvm::Value *AllocSize;
1170 
getPlacementArgs()1171     RValue *getPlacementArgs() { return reinterpret_cast<RValue*>(this+1); }
1172 
1173   public:
getExtraSize(size_t NumPlacementArgs)1174     static size_t getExtraSize(size_t NumPlacementArgs) {
1175       return NumPlacementArgs * sizeof(RValue);
1176     }
1177 
CallDeleteDuringNew(size_t NumPlacementArgs,const FunctionDecl * OperatorDelete,llvm::Value * Ptr,llvm::Value * AllocSize)1178     CallDeleteDuringNew(size_t NumPlacementArgs,
1179                         const FunctionDecl *OperatorDelete,
1180                         llvm::Value *Ptr,
1181                         llvm::Value *AllocSize)
1182       : NumPlacementArgs(NumPlacementArgs), OperatorDelete(OperatorDelete),
1183         Ptr(Ptr), AllocSize(AllocSize) {}
1184 
setPlacementArg(unsigned I,RValue Arg)1185     void setPlacementArg(unsigned I, RValue Arg) {
1186       assert(I < NumPlacementArgs && "index out of range");
1187       getPlacementArgs()[I] = Arg;
1188     }
1189 
Emit(CodeGenFunction & CGF,Flags flags)1190     void Emit(CodeGenFunction &CGF, Flags flags) override {
1191       const FunctionProtoType *FPT
1192         = OperatorDelete->getType()->getAs<FunctionProtoType>();
1193       assert(FPT->getNumParams() == NumPlacementArgs + 1 ||
1194              (FPT->getNumParams() == 2 && NumPlacementArgs == 0));
1195 
1196       CallArgList DeleteArgs;
1197 
1198       // The first argument is always a void*.
1199       FunctionProtoType::param_type_iterator AI = FPT->param_type_begin();
1200       DeleteArgs.add(RValue::get(Ptr), *AI++);
1201 
1202       // A member 'operator delete' can take an extra 'size_t' argument.
1203       if (FPT->getNumParams() == NumPlacementArgs + 2)
1204         DeleteArgs.add(RValue::get(AllocSize), *AI++);
1205 
1206       // Pass the rest of the arguments, which must match exactly.
1207       for (unsigned I = 0; I != NumPlacementArgs; ++I)
1208         DeleteArgs.add(getPlacementArgs()[I], *AI++);
1209 
1210       // Call 'operator delete'.
1211       EmitNewDeleteCall(CGF, OperatorDelete, FPT, DeleteArgs);
1212     }
1213   };
1214 
1215   /// A cleanup to call the given 'operator delete' function upon
1216   /// abnormal exit from a new expression when the new expression is
1217   /// conditional.
1218   class CallDeleteDuringConditionalNew final : public EHScopeStack::Cleanup {
1219     size_t NumPlacementArgs;
1220     const FunctionDecl *OperatorDelete;
1221     DominatingValue<RValue>::saved_type Ptr;
1222     DominatingValue<RValue>::saved_type AllocSize;
1223 
getPlacementArgs()1224     DominatingValue<RValue>::saved_type *getPlacementArgs() {
1225       return reinterpret_cast<DominatingValue<RValue>::saved_type*>(this+1);
1226     }
1227 
1228   public:
getExtraSize(size_t NumPlacementArgs)1229     static size_t getExtraSize(size_t NumPlacementArgs) {
1230       return NumPlacementArgs * sizeof(DominatingValue<RValue>::saved_type);
1231     }
1232 
CallDeleteDuringConditionalNew(size_t NumPlacementArgs,const FunctionDecl * OperatorDelete,DominatingValue<RValue>::saved_type Ptr,DominatingValue<RValue>::saved_type AllocSize)1233     CallDeleteDuringConditionalNew(size_t NumPlacementArgs,
1234                                    const FunctionDecl *OperatorDelete,
1235                                    DominatingValue<RValue>::saved_type Ptr,
1236                               DominatingValue<RValue>::saved_type AllocSize)
1237       : NumPlacementArgs(NumPlacementArgs), OperatorDelete(OperatorDelete),
1238         Ptr(Ptr), AllocSize(AllocSize) {}
1239 
setPlacementArg(unsigned I,DominatingValue<RValue>::saved_type Arg)1240     void setPlacementArg(unsigned I, DominatingValue<RValue>::saved_type Arg) {
1241       assert(I < NumPlacementArgs && "index out of range");
1242       getPlacementArgs()[I] = Arg;
1243     }
1244 
Emit(CodeGenFunction & CGF,Flags flags)1245     void Emit(CodeGenFunction &CGF, Flags flags) override {
1246       const FunctionProtoType *FPT
1247         = OperatorDelete->getType()->getAs<FunctionProtoType>();
1248       assert(FPT->getNumParams() == NumPlacementArgs + 1 ||
1249              (FPT->getNumParams() == 2 && NumPlacementArgs == 0));
1250 
1251       CallArgList DeleteArgs;
1252 
1253       // The first argument is always a void*.
1254       FunctionProtoType::param_type_iterator AI = FPT->param_type_begin();
1255       DeleteArgs.add(Ptr.restore(CGF), *AI++);
1256 
1257       // A member 'operator delete' can take an extra 'size_t' argument.
1258       if (FPT->getNumParams() == NumPlacementArgs + 2) {
1259         RValue RV = AllocSize.restore(CGF);
1260         DeleteArgs.add(RV, *AI++);
1261       }
1262 
1263       // Pass the rest of the arguments, which must match exactly.
1264       for (unsigned I = 0; I != NumPlacementArgs; ++I) {
1265         RValue RV = getPlacementArgs()[I].restore(CGF);
1266         DeleteArgs.add(RV, *AI++);
1267       }
1268 
1269       // Call 'operator delete'.
1270       EmitNewDeleteCall(CGF, OperatorDelete, FPT, DeleteArgs);
1271     }
1272   };
1273 }
1274 
1275 /// Enter a cleanup to call 'operator delete' if the initializer in a
1276 /// new-expression throws.
EnterNewDeleteCleanup(CodeGenFunction & CGF,const CXXNewExpr * E,Address NewPtr,llvm::Value * AllocSize,const CallArgList & NewArgs)1277 static void EnterNewDeleteCleanup(CodeGenFunction &CGF,
1278                                   const CXXNewExpr *E,
1279                                   Address NewPtr,
1280                                   llvm::Value *AllocSize,
1281                                   const CallArgList &NewArgs) {
1282   // If we're not inside a conditional branch, then the cleanup will
1283   // dominate and we can do the easier (and more efficient) thing.
1284   if (!CGF.isInConditionalBranch()) {
1285     CallDeleteDuringNew *Cleanup = CGF.EHStack
1286       .pushCleanupWithExtra<CallDeleteDuringNew>(EHCleanup,
1287                                                  E->getNumPlacementArgs(),
1288                                                  E->getOperatorDelete(),
1289                                                  NewPtr.getPointer(),
1290                                                  AllocSize);
1291     for (unsigned I = 0, N = E->getNumPlacementArgs(); I != N; ++I)
1292       Cleanup->setPlacementArg(I, NewArgs[I+1].RV);
1293 
1294     return;
1295   }
1296 
1297   // Otherwise, we need to save all this stuff.
1298   DominatingValue<RValue>::saved_type SavedNewPtr =
1299     DominatingValue<RValue>::save(CGF, RValue::get(NewPtr.getPointer()));
1300   DominatingValue<RValue>::saved_type SavedAllocSize =
1301     DominatingValue<RValue>::save(CGF, RValue::get(AllocSize));
1302 
1303   CallDeleteDuringConditionalNew *Cleanup = CGF.EHStack
1304     .pushCleanupWithExtra<CallDeleteDuringConditionalNew>(EHCleanup,
1305                                                  E->getNumPlacementArgs(),
1306                                                  E->getOperatorDelete(),
1307                                                  SavedNewPtr,
1308                                                  SavedAllocSize);
1309   for (unsigned I = 0, N = E->getNumPlacementArgs(); I != N; ++I)
1310     Cleanup->setPlacementArg(I,
1311                      DominatingValue<RValue>::save(CGF, NewArgs[I+1].RV));
1312 
1313   CGF.initFullExprCleanup();
1314 }
1315 
EmitCXXNewExpr(const CXXNewExpr * E)1316 llvm::Value *CodeGenFunction::EmitCXXNewExpr(const CXXNewExpr *E) {
1317   // The element type being allocated.
1318   QualType allocType = getContext().getBaseElementType(E->getAllocatedType());
1319 
1320   // 1. Build a call to the allocation function.
1321   FunctionDecl *allocator = E->getOperatorNew();
1322 
1323   // If there is a brace-initializer, cannot allocate fewer elements than inits.
1324   unsigned minElements = 0;
1325   if (E->isArray() && E->hasInitializer()) {
1326     if (const InitListExpr *ILE = dyn_cast<InitListExpr>(E->getInitializer()))
1327       minElements = ILE->getNumInits();
1328   }
1329 
1330   llvm::Value *numElements = nullptr;
1331   llvm::Value *allocSizeWithoutCookie = nullptr;
1332   llvm::Value *allocSize =
1333     EmitCXXNewAllocSize(*this, E, minElements, numElements,
1334                         allocSizeWithoutCookie);
1335 
1336   // Emit the allocation call.  If the allocator is a global placement
1337   // operator, just "inline" it directly.
1338   Address allocation = Address::invalid();
1339   CallArgList allocatorArgs;
1340   if (allocator->isReservedGlobalPlacementOperator()) {
1341     assert(E->getNumPlacementArgs() == 1);
1342     const Expr *arg = *E->placement_arguments().begin();
1343 
1344     AlignmentSource alignSource;
1345     allocation = EmitPointerWithAlignment(arg, &alignSource);
1346 
1347     // The pointer expression will, in many cases, be an opaque void*.
1348     // In these cases, discard the computed alignment and use the
1349     // formal alignment of the allocated type.
1350     if (alignSource != AlignmentSource::Decl) {
1351       allocation = Address(allocation.getPointer(),
1352                            getContext().getTypeAlignInChars(allocType));
1353     }
1354 
1355     // Set up allocatorArgs for the call to operator delete if it's not
1356     // the reserved global operator.
1357     if (E->getOperatorDelete() &&
1358         !E->getOperatorDelete()->isReservedGlobalPlacementOperator()) {
1359       allocatorArgs.add(RValue::get(allocSize), getContext().getSizeType());
1360       allocatorArgs.add(RValue::get(allocation.getPointer()), arg->getType());
1361     }
1362 
1363   } else {
1364     const FunctionProtoType *allocatorType =
1365       allocator->getType()->castAs<FunctionProtoType>();
1366 
1367     // The allocation size is the first argument.
1368     QualType sizeType = getContext().getSizeType();
1369     allocatorArgs.add(RValue::get(allocSize), sizeType);
1370 
1371     // We start at 1 here because the first argument (the allocation size)
1372     // has already been emitted.
1373     EmitCallArgs(allocatorArgs, allocatorType, E->placement_arguments(),
1374                  /* CalleeDecl */ nullptr,
1375                  /*ParamsToSkip*/ 1);
1376 
1377     RValue RV =
1378       EmitNewDeleteCall(*this, allocator, allocatorType, allocatorArgs);
1379 
1380     // For now, only assume that the allocation function returns
1381     // something satisfactorily aligned for the element type, plus
1382     // the cookie if we have one.
1383     CharUnits allocationAlign =
1384       getContext().getTypeAlignInChars(allocType);
1385     if (allocSize != allocSizeWithoutCookie) {
1386       CharUnits cookieAlign = getSizeAlign(); // FIXME?
1387       allocationAlign = std::max(allocationAlign, cookieAlign);
1388     }
1389 
1390     allocation = Address(RV.getScalarVal(), allocationAlign);
1391   }
1392 
1393   // Emit a null check on the allocation result if the allocation
1394   // function is allowed to return null (because it has a non-throwing
1395   // exception spec or is the reserved placement new) and we have an
1396   // interesting initializer.
1397   bool nullCheck = E->shouldNullCheckAllocation(getContext()) &&
1398     (!allocType.isPODType(getContext()) || E->hasInitializer());
1399 
1400   llvm::BasicBlock *nullCheckBB = nullptr;
1401   llvm::BasicBlock *contBB = nullptr;
1402 
1403   // The null-check means that the initializer is conditionally
1404   // evaluated.
1405   ConditionalEvaluation conditional(*this);
1406 
1407   if (nullCheck) {
1408     conditional.begin(*this);
1409 
1410     nullCheckBB = Builder.GetInsertBlock();
1411     llvm::BasicBlock *notNullBB = createBasicBlock("new.notnull");
1412     contBB = createBasicBlock("new.cont");
1413 
1414     llvm::Value *isNull =
1415       Builder.CreateIsNull(allocation.getPointer(), "new.isnull");
1416     Builder.CreateCondBr(isNull, contBB, notNullBB);
1417     EmitBlock(notNullBB);
1418   }
1419 
1420   // If there's an operator delete, enter a cleanup to call it if an
1421   // exception is thrown.
1422   EHScopeStack::stable_iterator operatorDeleteCleanup;
1423   llvm::Instruction *cleanupDominator = nullptr;
1424   if (E->getOperatorDelete() &&
1425       !E->getOperatorDelete()->isReservedGlobalPlacementOperator()) {
1426     EnterNewDeleteCleanup(*this, E, allocation, allocSize, allocatorArgs);
1427     operatorDeleteCleanup = EHStack.stable_begin();
1428     cleanupDominator = Builder.CreateUnreachable();
1429   }
1430 
1431   assert((allocSize == allocSizeWithoutCookie) ==
1432          CalculateCookiePadding(*this, E).isZero());
1433   if (allocSize != allocSizeWithoutCookie) {
1434     assert(E->isArray());
1435     allocation = CGM.getCXXABI().InitializeArrayCookie(*this, allocation,
1436                                                        numElements,
1437                                                        E, allocType);
1438   }
1439 
1440   llvm::Type *elementTy = ConvertTypeForMem(allocType);
1441   Address result = Builder.CreateElementBitCast(allocation, elementTy);
1442 
1443   // Passing pointer through invariant.group.barrier to avoid propagation of
1444   // vptrs information which may be included in previous type.
1445   if (CGM.getCodeGenOpts().StrictVTablePointers &&
1446       CGM.getCodeGenOpts().OptimizationLevel > 0 &&
1447       allocator->isReservedGlobalPlacementOperator())
1448     result = Address(Builder.CreateInvariantGroupBarrier(result.getPointer()),
1449                      result.getAlignment());
1450 
1451   EmitNewInitializer(*this, E, allocType, elementTy, result, numElements,
1452                      allocSizeWithoutCookie);
1453   if (E->isArray()) {
1454     // NewPtr is a pointer to the base element type.  If we're
1455     // allocating an array of arrays, we'll need to cast back to the
1456     // array pointer type.
1457     llvm::Type *resultType = ConvertTypeForMem(E->getType());
1458     if (result.getType() != resultType)
1459       result = Builder.CreateBitCast(result, resultType);
1460   }
1461 
1462   // Deactivate the 'operator delete' cleanup if we finished
1463   // initialization.
1464   if (operatorDeleteCleanup.isValid()) {
1465     DeactivateCleanupBlock(operatorDeleteCleanup, cleanupDominator);
1466     cleanupDominator->eraseFromParent();
1467   }
1468 
1469   llvm::Value *resultPtr = result.getPointer();
1470   if (nullCheck) {
1471     conditional.end(*this);
1472 
1473     llvm::BasicBlock *notNullBB = Builder.GetInsertBlock();
1474     EmitBlock(contBB);
1475 
1476     llvm::PHINode *PHI = Builder.CreatePHI(resultPtr->getType(), 2);
1477     PHI->addIncoming(resultPtr, notNullBB);
1478     PHI->addIncoming(llvm::Constant::getNullValue(resultPtr->getType()),
1479                      nullCheckBB);
1480 
1481     resultPtr = PHI;
1482   }
1483 
1484   return resultPtr;
1485 }
1486 
EmitDeleteCall(const FunctionDecl * DeleteFD,llvm::Value * Ptr,QualType DeleteTy)1487 void CodeGenFunction::EmitDeleteCall(const FunctionDecl *DeleteFD,
1488                                      llvm::Value *Ptr,
1489                                      QualType DeleteTy) {
1490   assert(DeleteFD->getOverloadedOperator() == OO_Delete);
1491 
1492   const FunctionProtoType *DeleteFTy =
1493     DeleteFD->getType()->getAs<FunctionProtoType>();
1494 
1495   CallArgList DeleteArgs;
1496 
1497   // Check if we need to pass the size to the delete operator.
1498   llvm::Value *Size = nullptr;
1499   QualType SizeTy;
1500   if (DeleteFTy->getNumParams() == 2) {
1501     SizeTy = DeleteFTy->getParamType(1);
1502     CharUnits DeleteTypeSize = getContext().getTypeSizeInChars(DeleteTy);
1503     Size = llvm::ConstantInt::get(ConvertType(SizeTy),
1504                                   DeleteTypeSize.getQuantity());
1505   }
1506 
1507   QualType ArgTy = DeleteFTy->getParamType(0);
1508   llvm::Value *DeletePtr = Builder.CreateBitCast(Ptr, ConvertType(ArgTy));
1509   DeleteArgs.add(RValue::get(DeletePtr), ArgTy);
1510 
1511   if (Size)
1512     DeleteArgs.add(RValue::get(Size), SizeTy);
1513 
1514   // Emit the call to delete.
1515   EmitNewDeleteCall(*this, DeleteFD, DeleteFTy, DeleteArgs);
1516 }
1517 
1518 namespace {
1519   /// Calls the given 'operator delete' on a single object.
1520   struct CallObjectDelete final : EHScopeStack::Cleanup {
1521     llvm::Value *Ptr;
1522     const FunctionDecl *OperatorDelete;
1523     QualType ElementType;
1524 
CallObjectDelete__anone8d8cb250311::CallObjectDelete1525     CallObjectDelete(llvm::Value *Ptr,
1526                      const FunctionDecl *OperatorDelete,
1527                      QualType ElementType)
1528       : Ptr(Ptr), OperatorDelete(OperatorDelete), ElementType(ElementType) {}
1529 
Emit__anone8d8cb250311::CallObjectDelete1530     void Emit(CodeGenFunction &CGF, Flags flags) override {
1531       CGF.EmitDeleteCall(OperatorDelete, Ptr, ElementType);
1532     }
1533   };
1534 }
1535 
1536 void
pushCallObjectDeleteCleanup(const FunctionDecl * OperatorDelete,llvm::Value * CompletePtr,QualType ElementType)1537 CodeGenFunction::pushCallObjectDeleteCleanup(const FunctionDecl *OperatorDelete,
1538                                              llvm::Value *CompletePtr,
1539                                              QualType ElementType) {
1540   EHStack.pushCleanup<CallObjectDelete>(NormalAndEHCleanup, CompletePtr,
1541                                         OperatorDelete, ElementType);
1542 }
1543 
1544 /// Emit the code for deleting a single object.
EmitObjectDelete(CodeGenFunction & CGF,const CXXDeleteExpr * DE,Address Ptr,QualType ElementType)1545 static void EmitObjectDelete(CodeGenFunction &CGF,
1546                              const CXXDeleteExpr *DE,
1547                              Address Ptr,
1548                              QualType ElementType) {
1549   // Find the destructor for the type, if applicable.  If the
1550   // destructor is virtual, we'll just emit the vcall and return.
1551   const CXXDestructorDecl *Dtor = nullptr;
1552   if (const RecordType *RT = ElementType->getAs<RecordType>()) {
1553     CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
1554     if (RD->hasDefinition() && !RD->hasTrivialDestructor()) {
1555       Dtor = RD->getDestructor();
1556 
1557       if (Dtor->isVirtual()) {
1558         CGF.CGM.getCXXABI().emitVirtualObjectDelete(CGF, DE, Ptr, ElementType,
1559                                                     Dtor);
1560         return;
1561       }
1562     }
1563   }
1564 
1565   // Make sure that we call delete even if the dtor throws.
1566   // This doesn't have to a conditional cleanup because we're going
1567   // to pop it off in a second.
1568   const FunctionDecl *OperatorDelete = DE->getOperatorDelete();
1569   CGF.EHStack.pushCleanup<CallObjectDelete>(NormalAndEHCleanup,
1570                                             Ptr.getPointer(),
1571                                             OperatorDelete, ElementType);
1572 
1573   if (Dtor)
1574     CGF.EmitCXXDestructorCall(Dtor, Dtor_Complete,
1575                               /*ForVirtualBase=*/false,
1576                               /*Delegating=*/false,
1577                               Ptr);
1578   else if (auto Lifetime = ElementType.getObjCLifetime()) {
1579     switch (Lifetime) {
1580     case Qualifiers::OCL_None:
1581     case Qualifiers::OCL_ExplicitNone:
1582     case Qualifiers::OCL_Autoreleasing:
1583       break;
1584 
1585     case Qualifiers::OCL_Strong:
1586       CGF.EmitARCDestroyStrong(Ptr, ARCPreciseLifetime);
1587       break;
1588 
1589     case Qualifiers::OCL_Weak:
1590       CGF.EmitARCDestroyWeak(Ptr);
1591       break;
1592     }
1593   }
1594 
1595   CGF.PopCleanupBlock();
1596 }
1597 
1598 namespace {
1599   /// Calls the given 'operator delete' on an array of objects.
1600   struct CallArrayDelete final : EHScopeStack::Cleanup {
1601     llvm::Value *Ptr;
1602     const FunctionDecl *OperatorDelete;
1603     llvm::Value *NumElements;
1604     QualType ElementType;
1605     CharUnits CookieSize;
1606 
CallArrayDelete__anone8d8cb250411::CallArrayDelete1607     CallArrayDelete(llvm::Value *Ptr,
1608                     const FunctionDecl *OperatorDelete,
1609                     llvm::Value *NumElements,
1610                     QualType ElementType,
1611                     CharUnits CookieSize)
1612       : Ptr(Ptr), OperatorDelete(OperatorDelete), NumElements(NumElements),
1613         ElementType(ElementType), CookieSize(CookieSize) {}
1614 
Emit__anone8d8cb250411::CallArrayDelete1615     void Emit(CodeGenFunction &CGF, Flags flags) override {
1616       const FunctionProtoType *DeleteFTy =
1617         OperatorDelete->getType()->getAs<FunctionProtoType>();
1618       assert(DeleteFTy->getNumParams() == 1 || DeleteFTy->getNumParams() == 2);
1619 
1620       CallArgList Args;
1621 
1622       // Pass the pointer as the first argument.
1623       QualType VoidPtrTy = DeleteFTy->getParamType(0);
1624       llvm::Value *DeletePtr
1625         = CGF.Builder.CreateBitCast(Ptr, CGF.ConvertType(VoidPtrTy));
1626       Args.add(RValue::get(DeletePtr), VoidPtrTy);
1627 
1628       // Pass the original requested size as the second argument.
1629       if (DeleteFTy->getNumParams() == 2) {
1630         QualType size_t = DeleteFTy->getParamType(1);
1631         llvm::IntegerType *SizeTy
1632           = cast<llvm::IntegerType>(CGF.ConvertType(size_t));
1633 
1634         CharUnits ElementTypeSize =
1635           CGF.CGM.getContext().getTypeSizeInChars(ElementType);
1636 
1637         // The size of an element, multiplied by the number of elements.
1638         llvm::Value *Size
1639           = llvm::ConstantInt::get(SizeTy, ElementTypeSize.getQuantity());
1640         if (NumElements)
1641           Size = CGF.Builder.CreateMul(Size, NumElements);
1642 
1643         // Plus the size of the cookie if applicable.
1644         if (!CookieSize.isZero()) {
1645           llvm::Value *CookieSizeV
1646             = llvm::ConstantInt::get(SizeTy, CookieSize.getQuantity());
1647           Size = CGF.Builder.CreateAdd(Size, CookieSizeV);
1648         }
1649 
1650         Args.add(RValue::get(Size), size_t);
1651       }
1652 
1653       // Emit the call to delete.
1654       EmitNewDeleteCall(CGF, OperatorDelete, DeleteFTy, Args);
1655     }
1656   };
1657 }
1658 
1659 /// Emit the code for deleting an array of objects.
EmitArrayDelete(CodeGenFunction & CGF,const CXXDeleteExpr * E,Address deletedPtr,QualType elementType)1660 static void EmitArrayDelete(CodeGenFunction &CGF,
1661                             const CXXDeleteExpr *E,
1662                             Address deletedPtr,
1663                             QualType elementType) {
1664   llvm::Value *numElements = nullptr;
1665   llvm::Value *allocatedPtr = nullptr;
1666   CharUnits cookieSize;
1667   CGF.CGM.getCXXABI().ReadArrayCookie(CGF, deletedPtr, E, elementType,
1668                                       numElements, allocatedPtr, cookieSize);
1669 
1670   assert(allocatedPtr && "ReadArrayCookie didn't set allocated pointer");
1671 
1672   // Make sure that we call delete even if one of the dtors throws.
1673   const FunctionDecl *operatorDelete = E->getOperatorDelete();
1674   CGF.EHStack.pushCleanup<CallArrayDelete>(NormalAndEHCleanup,
1675                                            allocatedPtr, operatorDelete,
1676                                            numElements, elementType,
1677                                            cookieSize);
1678 
1679   // Destroy the elements.
1680   if (QualType::DestructionKind dtorKind = elementType.isDestructedType()) {
1681     assert(numElements && "no element count for a type with a destructor!");
1682 
1683     CharUnits elementSize = CGF.getContext().getTypeSizeInChars(elementType);
1684     CharUnits elementAlign =
1685       deletedPtr.getAlignment().alignmentOfArrayElement(elementSize);
1686 
1687     llvm::Value *arrayBegin = deletedPtr.getPointer();
1688     llvm::Value *arrayEnd =
1689       CGF.Builder.CreateInBoundsGEP(arrayBegin, numElements, "delete.end");
1690 
1691     // Note that it is legal to allocate a zero-length array, and we
1692     // can never fold the check away because the length should always
1693     // come from a cookie.
1694     CGF.emitArrayDestroy(arrayBegin, arrayEnd, elementType, elementAlign,
1695                          CGF.getDestroyer(dtorKind),
1696                          /*checkZeroLength*/ true,
1697                          CGF.needsEHCleanup(dtorKind));
1698   }
1699 
1700   // Pop the cleanup block.
1701   CGF.PopCleanupBlock();
1702 }
1703 
EmitCXXDeleteExpr(const CXXDeleteExpr * E)1704 void CodeGenFunction::EmitCXXDeleteExpr(const CXXDeleteExpr *E) {
1705   const Expr *Arg = E->getArgument();
1706   Address Ptr = EmitPointerWithAlignment(Arg);
1707 
1708   // Null check the pointer.
1709   llvm::BasicBlock *DeleteNotNull = createBasicBlock("delete.notnull");
1710   llvm::BasicBlock *DeleteEnd = createBasicBlock("delete.end");
1711 
1712   llvm::Value *IsNull = Builder.CreateIsNull(Ptr.getPointer(), "isnull");
1713 
1714   Builder.CreateCondBr(IsNull, DeleteEnd, DeleteNotNull);
1715   EmitBlock(DeleteNotNull);
1716 
1717   // We might be deleting a pointer to array.  If so, GEP down to the
1718   // first non-array element.
1719   // (this assumes that A(*)[3][7] is converted to [3 x [7 x %A]]*)
1720   QualType DeleteTy = Arg->getType()->getAs<PointerType>()->getPointeeType();
1721   if (DeleteTy->isConstantArrayType()) {
1722     llvm::Value *Zero = Builder.getInt32(0);
1723     SmallVector<llvm::Value*,8> GEP;
1724 
1725     GEP.push_back(Zero); // point at the outermost array
1726 
1727     // For each layer of array type we're pointing at:
1728     while (const ConstantArrayType *Arr
1729              = getContext().getAsConstantArrayType(DeleteTy)) {
1730       // 1. Unpeel the array type.
1731       DeleteTy = Arr->getElementType();
1732 
1733       // 2. GEP to the first element of the array.
1734       GEP.push_back(Zero);
1735     }
1736 
1737     Ptr = Address(Builder.CreateInBoundsGEP(Ptr.getPointer(), GEP, "del.first"),
1738                   Ptr.getAlignment());
1739   }
1740 
1741   assert(ConvertTypeForMem(DeleteTy) == Ptr.getElementType());
1742 
1743   if (E->isArrayForm()) {
1744     EmitArrayDelete(*this, E, Ptr, DeleteTy);
1745   } else {
1746     EmitObjectDelete(*this, E, Ptr, DeleteTy);
1747   }
1748 
1749   EmitBlock(DeleteEnd);
1750 }
1751 
isGLValueFromPointerDeref(const Expr * E)1752 static bool isGLValueFromPointerDeref(const Expr *E) {
1753   E = E->IgnoreParens();
1754 
1755   if (const auto *CE = dyn_cast<CastExpr>(E)) {
1756     if (!CE->getSubExpr()->isGLValue())
1757       return false;
1758     return isGLValueFromPointerDeref(CE->getSubExpr());
1759   }
1760 
1761   if (const auto *OVE = dyn_cast<OpaqueValueExpr>(E))
1762     return isGLValueFromPointerDeref(OVE->getSourceExpr());
1763 
1764   if (const auto *BO = dyn_cast<BinaryOperator>(E))
1765     if (BO->getOpcode() == BO_Comma)
1766       return isGLValueFromPointerDeref(BO->getRHS());
1767 
1768   if (const auto *ACO = dyn_cast<AbstractConditionalOperator>(E))
1769     return isGLValueFromPointerDeref(ACO->getTrueExpr()) ||
1770            isGLValueFromPointerDeref(ACO->getFalseExpr());
1771 
1772   // C++11 [expr.sub]p1:
1773   //   The expression E1[E2] is identical (by definition) to *((E1)+(E2))
1774   if (isa<ArraySubscriptExpr>(E))
1775     return true;
1776 
1777   if (const auto *UO = dyn_cast<UnaryOperator>(E))
1778     if (UO->getOpcode() == UO_Deref)
1779       return true;
1780 
1781   return false;
1782 }
1783 
EmitTypeidFromVTable(CodeGenFunction & CGF,const Expr * E,llvm::Type * StdTypeInfoPtrTy)1784 static llvm::Value *EmitTypeidFromVTable(CodeGenFunction &CGF, const Expr *E,
1785                                          llvm::Type *StdTypeInfoPtrTy) {
1786   // Get the vtable pointer.
1787   Address ThisPtr = CGF.EmitLValue(E).getAddress();
1788 
1789   // C++ [expr.typeid]p2:
1790   //   If the glvalue expression is obtained by applying the unary * operator to
1791   //   a pointer and the pointer is a null pointer value, the typeid expression
1792   //   throws the std::bad_typeid exception.
1793   //
1794   // However, this paragraph's intent is not clear.  We choose a very generous
1795   // interpretation which implores us to consider comma operators, conditional
1796   // operators, parentheses and other such constructs.
1797   QualType SrcRecordTy = E->getType();
1798   if (CGF.CGM.getCXXABI().shouldTypeidBeNullChecked(
1799           isGLValueFromPointerDeref(E), SrcRecordTy)) {
1800     llvm::BasicBlock *BadTypeidBlock =
1801         CGF.createBasicBlock("typeid.bad_typeid");
1802     llvm::BasicBlock *EndBlock = CGF.createBasicBlock("typeid.end");
1803 
1804     llvm::Value *IsNull = CGF.Builder.CreateIsNull(ThisPtr.getPointer());
1805     CGF.Builder.CreateCondBr(IsNull, BadTypeidBlock, EndBlock);
1806 
1807     CGF.EmitBlock(BadTypeidBlock);
1808     CGF.CGM.getCXXABI().EmitBadTypeidCall(CGF);
1809     CGF.EmitBlock(EndBlock);
1810   }
1811 
1812   return CGF.CGM.getCXXABI().EmitTypeid(CGF, SrcRecordTy, ThisPtr,
1813                                         StdTypeInfoPtrTy);
1814 }
1815 
EmitCXXTypeidExpr(const CXXTypeidExpr * E)1816 llvm::Value *CodeGenFunction::EmitCXXTypeidExpr(const CXXTypeidExpr *E) {
1817   llvm::Type *StdTypeInfoPtrTy =
1818     ConvertType(E->getType())->getPointerTo();
1819 
1820   if (E->isTypeOperand()) {
1821     llvm::Constant *TypeInfo =
1822         CGM.GetAddrOfRTTIDescriptor(E->getTypeOperand(getContext()));
1823     return Builder.CreateBitCast(TypeInfo, StdTypeInfoPtrTy);
1824   }
1825 
1826   // C++ [expr.typeid]p2:
1827   //   When typeid is applied to a glvalue expression whose type is a
1828   //   polymorphic class type, the result refers to a std::type_info object
1829   //   representing the type of the most derived object (that is, the dynamic
1830   //   type) to which the glvalue refers.
1831   if (E->isPotentiallyEvaluated())
1832     return EmitTypeidFromVTable(*this, E->getExprOperand(),
1833                                 StdTypeInfoPtrTy);
1834 
1835   QualType OperandTy = E->getExprOperand()->getType();
1836   return Builder.CreateBitCast(CGM.GetAddrOfRTTIDescriptor(OperandTy),
1837                                StdTypeInfoPtrTy);
1838 }
1839 
EmitDynamicCastToNull(CodeGenFunction & CGF,QualType DestTy)1840 static llvm::Value *EmitDynamicCastToNull(CodeGenFunction &CGF,
1841                                           QualType DestTy) {
1842   llvm::Type *DestLTy = CGF.ConvertType(DestTy);
1843   if (DestTy->isPointerType())
1844     return llvm::Constant::getNullValue(DestLTy);
1845 
1846   /// C++ [expr.dynamic.cast]p9:
1847   ///   A failed cast to reference type throws std::bad_cast
1848   if (!CGF.CGM.getCXXABI().EmitBadCastCall(CGF))
1849     return nullptr;
1850 
1851   CGF.EmitBlock(CGF.createBasicBlock("dynamic_cast.end"));
1852   return llvm::UndefValue::get(DestLTy);
1853 }
1854 
EmitDynamicCast(Address ThisAddr,const CXXDynamicCastExpr * DCE)1855 llvm::Value *CodeGenFunction::EmitDynamicCast(Address ThisAddr,
1856                                               const CXXDynamicCastExpr *DCE) {
1857   CGM.EmitExplicitCastExprType(DCE, this);
1858   QualType DestTy = DCE->getTypeAsWritten();
1859 
1860   if (DCE->isAlwaysNull())
1861     if (llvm::Value *T = EmitDynamicCastToNull(*this, DestTy))
1862       return T;
1863 
1864   QualType SrcTy = DCE->getSubExpr()->getType();
1865 
1866   // C++ [expr.dynamic.cast]p7:
1867   //   If T is "pointer to cv void," then the result is a pointer to the most
1868   //   derived object pointed to by v.
1869   const PointerType *DestPTy = DestTy->getAs<PointerType>();
1870 
1871   bool isDynamicCastToVoid;
1872   QualType SrcRecordTy;
1873   QualType DestRecordTy;
1874   if (DestPTy) {
1875     isDynamicCastToVoid = DestPTy->getPointeeType()->isVoidType();
1876     SrcRecordTy = SrcTy->castAs<PointerType>()->getPointeeType();
1877     DestRecordTy = DestPTy->getPointeeType();
1878   } else {
1879     isDynamicCastToVoid = false;
1880     SrcRecordTy = SrcTy;
1881     DestRecordTy = DestTy->castAs<ReferenceType>()->getPointeeType();
1882   }
1883 
1884   assert(SrcRecordTy->isRecordType() && "source type must be a record type!");
1885 
1886   // C++ [expr.dynamic.cast]p4:
1887   //   If the value of v is a null pointer value in the pointer case, the result
1888   //   is the null pointer value of type T.
1889   bool ShouldNullCheckSrcValue =
1890       CGM.getCXXABI().shouldDynamicCastCallBeNullChecked(SrcTy->isPointerType(),
1891                                                          SrcRecordTy);
1892 
1893   llvm::BasicBlock *CastNull = nullptr;
1894   llvm::BasicBlock *CastNotNull = nullptr;
1895   llvm::BasicBlock *CastEnd = createBasicBlock("dynamic_cast.end");
1896 
1897   if (ShouldNullCheckSrcValue) {
1898     CastNull = createBasicBlock("dynamic_cast.null");
1899     CastNotNull = createBasicBlock("dynamic_cast.notnull");
1900 
1901     llvm::Value *IsNull = Builder.CreateIsNull(ThisAddr.getPointer());
1902     Builder.CreateCondBr(IsNull, CastNull, CastNotNull);
1903     EmitBlock(CastNotNull);
1904   }
1905 
1906   llvm::Value *Value;
1907   if (isDynamicCastToVoid) {
1908     Value = CGM.getCXXABI().EmitDynamicCastToVoid(*this, ThisAddr, SrcRecordTy,
1909                                                   DestTy);
1910   } else {
1911     assert(DestRecordTy->isRecordType() &&
1912            "destination type must be a record type!");
1913     Value = CGM.getCXXABI().EmitDynamicCastCall(*this, ThisAddr, SrcRecordTy,
1914                                                 DestTy, DestRecordTy, CastEnd);
1915     CastNotNull = Builder.GetInsertBlock();
1916   }
1917 
1918   if (ShouldNullCheckSrcValue) {
1919     EmitBranch(CastEnd);
1920 
1921     EmitBlock(CastNull);
1922     EmitBranch(CastEnd);
1923   }
1924 
1925   EmitBlock(CastEnd);
1926 
1927   if (ShouldNullCheckSrcValue) {
1928     llvm::PHINode *PHI = Builder.CreatePHI(Value->getType(), 2);
1929     PHI->addIncoming(Value, CastNotNull);
1930     PHI->addIncoming(llvm::Constant::getNullValue(Value->getType()), CastNull);
1931 
1932     Value = PHI;
1933   }
1934 
1935   return Value;
1936 }
1937 
EmitLambdaExpr(const LambdaExpr * E,AggValueSlot Slot)1938 void CodeGenFunction::EmitLambdaExpr(const LambdaExpr *E, AggValueSlot Slot) {
1939   RunCleanupsScope Scope(*this);
1940   LValue SlotLV = MakeAddrLValue(Slot.getAddress(), E->getType());
1941 
1942   CXXRecordDecl::field_iterator CurField = E->getLambdaClass()->field_begin();
1943   for (LambdaExpr::const_capture_init_iterator i = E->capture_init_begin(),
1944                                                e = E->capture_init_end();
1945        i != e; ++i, ++CurField) {
1946     // Emit initialization
1947     LValue LV = EmitLValueForFieldInitialization(SlotLV, *CurField);
1948     if (CurField->hasCapturedVLAType()) {
1949       auto VAT = CurField->getCapturedVLAType();
1950       EmitStoreThroughLValue(RValue::get(VLASizeMap[VAT->getSizeExpr()]), LV);
1951     } else {
1952       ArrayRef<VarDecl *> ArrayIndexes;
1953       if (CurField->getType()->isArrayType())
1954         ArrayIndexes = E->getCaptureInitIndexVars(i);
1955       EmitInitializerForField(*CurField, LV, *i, ArrayIndexes);
1956     }
1957   }
1958 }
1959