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CGExprCXX.cpp 
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//===--- CGExprCXX.cpp - Emit LLVM Code for C++ expressions ---------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// This contains code dealing with code generation of C++ expressions
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//
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//===----------------------------------------------------------------------===//
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#include "CGCUDARuntime.h"
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#include "CGCXXABI.h"
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#include "CGDebugInfo.h"
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#include "CGObjCRuntime.h"
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#include "CodeGenFunction.h"
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#include "ConstantEmitter.h"
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#include "TargetInfo.h"
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#include "clang/Basic/CodeGenOptions.h"
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#include "clang/CodeGen/CGFunctionInfo.h"
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#include "llvm/IR/Intrinsics.h"
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using namespace clang;
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using namespace CodeGen;
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namespace {
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struct MemberCallInfo {
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  RequiredArgs ReqArgs;
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  // Number of prefix arguments for the call. Ignores the `this` pointer.
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  unsigned PrefixSize;
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};
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}
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static MemberCallInfo
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commonEmitCXXMemberOrOperatorCall(CodeGenFunction &CGF, GlobalDecl GD,
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                                  llvm::Value *This, llvm::Value *ImplicitParam,
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                                  QualType ImplicitParamTy, const CallExpr *CE,
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                                  CallArgList &Args, CallArgList *RtlArgs) {
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  auto *MD = cast<CXXMethodDecl>(GD.getDecl());
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  assert(CE == nullptr || isa<CXXMemberCallExpr>(CE) ||
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         isa<CXXOperatorCallExpr>(CE));
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  assert(MD->isImplicitObjectMemberFunction() &&
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         "Trying to emit a member or operator call expr on a static method!");
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  // Push the this ptr.
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  const CXXRecordDecl *RD =
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      CGF.CGM.getCXXABI().getThisArgumentTypeForMethod(GD);
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  Args.add(RValue::get(This), CGF.getTypes().DeriveThisType(RD, MD));
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  // If there is an implicit parameter (e.g. VTT), emit it.
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  if (ImplicitParam) {
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    Args.add(RValue::get(ImplicitParam), ImplicitParamTy);
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  }
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  const FunctionProtoType *FPT = MD->getType()->castAs<FunctionProtoType>();
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  RequiredArgs required = RequiredArgs::forPrototypePlus(FPT, Args.size());
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  unsigned PrefixSize = Args.size() - 1;
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  // And the rest of the call args.
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  if (RtlArgs) {
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    // Special case: if the caller emitted the arguments right-to-left already
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    // (prior to emitting the *this argument), we're done. This happens for
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    // assignment operators.
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    Args.addFrom(*RtlArgs);
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  } else if (CE) {
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    // Special case: skip first argument of CXXOperatorCall (it is "this").
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    unsigned ArgsToSkip = 0;
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    if (const auto *Op = dyn_cast<CXXOperatorCallExpr>(CE)) {
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      if (const auto *M = dyn_cast<CXXMethodDecl>(Op->getCalleeDecl()))
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        ArgsToSkip =
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            static_cast<unsigned>(!M->isExplicitObjectMemberFunction());
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    }
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    CGF.EmitCallArgs(Args, FPT, drop_begin(CE->arguments(), ArgsToSkip),
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                     CE->getDirectCallee());
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  } else {
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    assert(
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        FPT->getNumParams() == 0 &&
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        "No CallExpr specified for function with non-zero number of arguments");
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  }
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  return {required, PrefixSize};
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}
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RValue CodeGenFunction::EmitCXXMemberOrOperatorCall(
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    const CXXMethodDecl *MD, const CGCallee &Callee,
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    ReturnValueSlot ReturnValue,
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    llvm::Value *This, llvm::Value *ImplicitParam, QualType ImplicitParamTy,
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    const CallExpr *CE, CallArgList *RtlArgs) {
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  const FunctionProtoType *FPT = MD->getType()->castAs<FunctionProtoType>();
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  CallArgList Args;
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  MemberCallInfo CallInfo = commonEmitCXXMemberOrOperatorCall(
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      *this, MD, This, ImplicitParam, ImplicitParamTy, CE, Args, RtlArgs);
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  auto &FnInfo = CGM.getTypes().arrangeCXXMethodCall(
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      Args, FPT, CallInfo.ReqArgs, CallInfo.PrefixSize);
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  return EmitCall(FnInfo, Callee, ReturnValue, Args, nullptr,
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                  CE && CE == MustTailCall,
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                  CE ? CE->getExprLoc() : SourceLocation());
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}
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101
RValue CodeGenFunction::EmitCXXDestructorCall(
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    GlobalDecl Dtor, const CGCallee &Callee, llvm::Value *This, QualType ThisTy,
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    llvm::Value *ImplicitParam, QualType ImplicitParamTy, const CallExpr *CE) {
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  const CXXMethodDecl *DtorDecl = cast<CXXMethodDecl>(Dtor.getDecl());
105

106
  assert(!ThisTy.isNull());
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  assert(ThisTy->getAsCXXRecordDecl() == DtorDecl->getParent() &&
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         "Pointer/Object mixup");
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  LangAS SrcAS = ThisTy.getAddressSpace();
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  LangAS DstAS = DtorDecl->getMethodQualifiers().getAddressSpace();
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  if (SrcAS != DstAS) {
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    QualType DstTy = DtorDecl->getThisType();
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    llvm::Type *NewType = CGM.getTypes().ConvertType(DstTy);
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    This = getTargetHooks().performAddrSpaceCast(*this, This, SrcAS, DstAS,
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                                                 NewType);
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  }
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  CallArgList Args;
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  commonEmitCXXMemberOrOperatorCall(*this, Dtor, This, ImplicitParam,
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                                    ImplicitParamTy, CE, Args, nullptr);
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  return EmitCall(CGM.getTypes().arrangeCXXStructorDeclaration(Dtor), Callee,
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                  ReturnValueSlot(), Args, nullptr, CE && CE == MustTailCall,
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                  CE ? CE->getExprLoc() : SourceLocation{});
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}
126

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RValue CodeGenFunction::EmitCXXPseudoDestructorExpr(
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                                            const CXXPseudoDestructorExpr *E) {
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  QualType DestroyedType = E->getDestroyedType();
130
  if (DestroyedType.hasStrongOrWeakObjCLifetime()) {
131
    // Automatic Reference Counting:
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    //   If the pseudo-expression names a retainable object with weak or
133
    //   strong lifetime, the object shall be released.
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    Expr *BaseExpr = E->getBase();
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    Address BaseValue = Address::invalid();
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    Qualifiers BaseQuals;
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    // If this is s.x, emit s as an lvalue. If it is s->x, emit s as a scalar.
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    if (E->isArrow()) {
140
      BaseValue = EmitPointerWithAlignment(BaseExpr);
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      const auto *PTy = BaseExpr->getType()->castAs<PointerType>();
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      BaseQuals = PTy->getPointeeType().getQualifiers();
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    } else {
144
      LValue BaseLV = EmitLValue(BaseExpr);
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      BaseValue = BaseLV.getAddress();
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      QualType BaseTy = BaseExpr->getType();
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      BaseQuals = BaseTy.getQualifiers();
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    }
149

150
    switch (DestroyedType.getObjCLifetime()) {
151
    case Qualifiers::OCL_None:
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    case Qualifiers::OCL_ExplicitNone:
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    case Qualifiers::OCL_Autoreleasing:
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      break;
155

156
    case Qualifiers::OCL_Strong:
157
      EmitARCRelease(Builder.CreateLoad(BaseValue,
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                        DestroyedType.isVolatileQualified()),
159
                     ARCPreciseLifetime);
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      break;
161

162
    case Qualifiers::OCL_Weak:
163
      EmitARCDestroyWeak(BaseValue);
164
      break;
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    }
166
  } else {
167
    // C++ [expr.pseudo]p1:
168
    //   The result shall only be used as the operand for the function call
169
    //   operator (), and the result of such a call has type void. The only
170
    //   effect is the evaluation of the postfix-expression before the dot or
171
    //   arrow.
172
    EmitIgnoredExpr(E->getBase());
173
  }
174

175
  return RValue::get(nullptr);
176
}
177

178
static CXXRecordDecl *getCXXRecord(const Expr *E) {
179
  QualType T = E->getType();
180
  if (const PointerType *PTy = T->getAs<PointerType>())
181
    T = PTy->getPointeeType();
182
  const RecordType *Ty = T->castAs<RecordType>();
183
  return cast<CXXRecordDecl>(Ty->getDecl());
184
}
185

186
// Note: This function also emit constructor calls to support a MSVC
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// extensions allowing explicit constructor function call.
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RValue CodeGenFunction::EmitCXXMemberCallExpr(const CXXMemberCallExpr *CE,
189
                                              ReturnValueSlot ReturnValue) {
190
  const Expr *callee = CE->getCallee()->IgnoreParens();
191

192
  if (isa<BinaryOperator>(callee))
193
    return EmitCXXMemberPointerCallExpr(CE, ReturnValue);
194

195
  const MemberExpr *ME = cast<MemberExpr>(callee);
196
  const CXXMethodDecl *MD = cast<CXXMethodDecl>(ME->getMemberDecl());
197

198
  if (MD->isStatic()) {
199
    // The method is static, emit it as we would a regular call.
200
    CGCallee callee =
201
        CGCallee::forDirect(CGM.GetAddrOfFunction(MD), GlobalDecl(MD));
202
    return EmitCall(getContext().getPointerType(MD->getType()), callee, CE,
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                    ReturnValue);
204
  }
205

206
  bool HasQualifier = ME->hasQualifier();
207
  NestedNameSpecifier *Qualifier = HasQualifier ? ME->getQualifier() : nullptr;
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  bool IsArrow = ME->isArrow();
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  const Expr *Base = ME->getBase();
210

211
  return EmitCXXMemberOrOperatorMemberCallExpr(
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      CE, MD, ReturnValue, HasQualifier, Qualifier, IsArrow, Base);
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}
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215
RValue CodeGenFunction::EmitCXXMemberOrOperatorMemberCallExpr(
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    const CallExpr *CE, const CXXMethodDecl *MD, ReturnValueSlot ReturnValue,
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    bool HasQualifier, NestedNameSpecifier *Qualifier, bool IsArrow,
218
    const Expr *Base) {
219
  assert(isa<CXXMemberCallExpr>(CE) || isa<CXXOperatorCallExpr>(CE));
220

221
  // Compute the object pointer.
222
  bool CanUseVirtualCall = MD->isVirtual() && !HasQualifier;
223

224
  const CXXMethodDecl *DevirtualizedMethod = nullptr;
225
  if (CanUseVirtualCall &&
226
      MD->getDevirtualizedMethod(Base, getLangOpts().AppleKext)) {
227
    const CXXRecordDecl *BestDynamicDecl = Base->getBestDynamicClassType();
228
    DevirtualizedMethod = MD->getCorrespondingMethodInClass(BestDynamicDecl);
229
    assert(DevirtualizedMethod);
230
    const CXXRecordDecl *DevirtualizedClass = DevirtualizedMethod->getParent();
231
    const Expr *Inner = Base->IgnoreParenBaseCasts();
232
    if (DevirtualizedMethod->getReturnType().getCanonicalType() !=
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        MD->getReturnType().getCanonicalType())
234
      // If the return types are not the same, this might be a case where more
235
      // code needs to run to compensate for it. For example, the derived
236
      // method might return a type that inherits form from the return
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      // type of MD and has a prefix.
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      // For now we just avoid devirtualizing these covariant cases.
239
      DevirtualizedMethod = nullptr;
240
    else if (getCXXRecord(Inner) == DevirtualizedClass)
241
      // If the class of the Inner expression is where the dynamic method
242
      // is defined, build the this pointer from it.
243
      Base = Inner;
244
    else if (getCXXRecord(Base) != DevirtualizedClass) {
245
      // If the method is defined in a class that is not the best dynamic
246
      // one or the one of the full expression, we would have to build
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      // a derived-to-base cast to compute the correct this pointer, but
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      // we don't have support for that yet, so do a virtual call.
249
      DevirtualizedMethod = nullptr;
250
    }
251
  }
252

253
  bool TrivialForCodegen =
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      MD->isTrivial() || (MD->isDefaulted() && MD->getParent()->isUnion());
255
  bool TrivialAssignment =
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      TrivialForCodegen &&
257
      (MD->isCopyAssignmentOperator() || MD->isMoveAssignmentOperator()) &&
258
      !MD->getParent()->mayInsertExtraPadding();
259

260
  // C++17 demands that we evaluate the RHS of a (possibly-compound) assignment
261
  // operator before the LHS.
262
  CallArgList RtlArgStorage;
263
  CallArgList *RtlArgs = nullptr;
264
  LValue TrivialAssignmentRHS;
265
  if (auto *OCE = dyn_cast<CXXOperatorCallExpr>(CE)) {
266
    if (OCE->isAssignmentOp()) {
267
      if (TrivialAssignment) {
268
        TrivialAssignmentRHS = EmitLValue(CE->getArg(1));
269
      } else {
270
        RtlArgs = &RtlArgStorage;
271
        EmitCallArgs(*RtlArgs, MD->getType()->castAs<FunctionProtoType>(),
272
                     drop_begin(CE->arguments(), 1), CE->getDirectCallee(),
273
                     /*ParamsToSkip*/0, EvaluationOrder::ForceRightToLeft);
274
      }
275
    }
276
  }
277

278
  LValue This;
279
  if (IsArrow) {
280
    LValueBaseInfo BaseInfo;
281
    TBAAAccessInfo TBAAInfo;
282
    Address ThisValue = EmitPointerWithAlignment(Base, &BaseInfo, &TBAAInfo);
283
    This = MakeAddrLValue(ThisValue, Base->getType()->getPointeeType(),
284
                          BaseInfo, TBAAInfo);
285
  } else {
286
    This = EmitLValue(Base);
287
  }
288

289
  if (const CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(MD)) {
290
    // This is the MSVC p->Ctor::Ctor(...) extension. We assume that's
291
    // constructing a new complete object of type Ctor.
292
    assert(!RtlArgs);
293
    assert(ReturnValue.isNull() && "Constructor shouldn't have return value");
294
    CallArgList Args;
295
    commonEmitCXXMemberOrOperatorCall(
296
        *this, {Ctor, Ctor_Complete}, This.getPointer(*this),
297
        /*ImplicitParam=*/nullptr,
298
        /*ImplicitParamTy=*/QualType(), CE, Args, nullptr);
299

300
    EmitCXXConstructorCall(Ctor, Ctor_Complete, /*ForVirtualBase=*/false,
301
                           /*Delegating=*/false, This.getAddress(), Args,
302
                           AggValueSlot::DoesNotOverlap, CE->getExprLoc(),
303
                           /*NewPointerIsChecked=*/false);
304
    return RValue::get(nullptr);
305
  }
306

307
  if (TrivialForCodegen) {
308
    if (isa<CXXDestructorDecl>(MD))
309
      return RValue::get(nullptr);
310

311
    if (TrivialAssignment) {
312
      // We don't like to generate the trivial copy/move assignment operator
313
      // when it isn't necessary; just produce the proper effect here.
314
      // It's important that we use the result of EmitLValue here rather than
315
      // emitting call arguments, in order to preserve TBAA information from
316
      // the RHS.
317
      LValue RHS = isa<CXXOperatorCallExpr>(CE)
318
                       ? TrivialAssignmentRHS
319
                       : EmitLValue(*CE->arg_begin());
320
      EmitAggregateAssign(This, RHS, CE->getType());
321
      return RValue::get(This.getPointer(*this));
322
    }
323

324
    assert(MD->getParent()->mayInsertExtraPadding() &&
325
           "unknown trivial member function");
326
  }
327

328
  // Compute the function type we're calling.
329
  const CXXMethodDecl *CalleeDecl =
330
      DevirtualizedMethod ? DevirtualizedMethod : MD;
331
  const CGFunctionInfo *FInfo = nullptr;
332
  if (const auto *Dtor = dyn_cast<CXXDestructorDecl>(CalleeDecl))
333
    FInfo = &CGM.getTypes().arrangeCXXStructorDeclaration(
334
        GlobalDecl(Dtor, Dtor_Complete));
335
  else
336
    FInfo = &CGM.getTypes().arrangeCXXMethodDeclaration(CalleeDecl);
337

338
  llvm::FunctionType *Ty = CGM.getTypes().GetFunctionType(*FInfo);
339

340
  // C++11 [class.mfct.non-static]p2:
341
  //   If a non-static member function of a class X is called for an object that
342
  //   is not of type X, or of a type derived from X, the behavior is undefined.
343
  SourceLocation CallLoc;
344
  ASTContext &C = getContext();
345
  if (CE)
346
    CallLoc = CE->getExprLoc();
347

348
  SanitizerSet SkippedChecks;
349
  if (const auto *CMCE = dyn_cast<CXXMemberCallExpr>(CE)) {
350
    auto *IOA = CMCE->getImplicitObjectArgument();
351
    bool IsImplicitObjectCXXThis = IsWrappedCXXThis(IOA);
352
    if (IsImplicitObjectCXXThis)
353
      SkippedChecks.set(SanitizerKind::Alignment, true);
354
    if (IsImplicitObjectCXXThis || isa<DeclRefExpr>(IOA))
355
      SkippedChecks.set(SanitizerKind::Null, true);
356
  }
357

358
  if (sanitizePerformTypeCheck())
359
    EmitTypeCheck(CodeGenFunction::TCK_MemberCall, CallLoc,
360
                  This.emitRawPointer(*this),
361
                  C.getRecordType(CalleeDecl->getParent()),
362
                  /*Alignment=*/CharUnits::Zero(), SkippedChecks);
363

364
  // C++ [class.virtual]p12:
365
  //   Explicit qualification with the scope operator (5.1) suppresses the
366
  //   virtual call mechanism.
367
  //
368
  // We also don't emit a virtual call if the base expression has a record type
369
  // because then we know what the type is.
370
  bool UseVirtualCall = CanUseVirtualCall && !DevirtualizedMethod;
371

372
  if (const CXXDestructorDecl *Dtor = dyn_cast<CXXDestructorDecl>(CalleeDecl)) {
373
    assert(CE->arg_begin() == CE->arg_end() &&
374
           "Destructor shouldn't have explicit parameters");
375
    assert(ReturnValue.isNull() && "Destructor shouldn't have return value");
376
    if (UseVirtualCall) {
377
      CGM.getCXXABI().EmitVirtualDestructorCall(*this, Dtor, Dtor_Complete,
378
                                                This.getAddress(),
379
                                                cast<CXXMemberCallExpr>(CE));
380
    } else {
381
      GlobalDecl GD(Dtor, Dtor_Complete);
382
      CGCallee Callee;
383
      if (getLangOpts().AppleKext && Dtor->isVirtual() && HasQualifier)
384
        Callee = BuildAppleKextVirtualCall(Dtor, Qualifier, Ty);
385
      else if (!DevirtualizedMethod)
386
        Callee =
387
            CGCallee::forDirect(CGM.getAddrOfCXXStructor(GD, FInfo, Ty), GD);
388
      else {
389
        Callee = CGCallee::forDirect(CGM.GetAddrOfFunction(GD, Ty), GD);
390
      }
391

392
      QualType ThisTy =
393
          IsArrow ? Base->getType()->getPointeeType() : Base->getType();
394
      EmitCXXDestructorCall(GD, Callee, This.getPointer(*this), ThisTy,
395
                            /*ImplicitParam=*/nullptr,
396
                            /*ImplicitParamTy=*/QualType(), CE);
397
    }
398
    return RValue::get(nullptr);
399
  }
400

401
  // FIXME: Uses of 'MD' past this point need to be audited. We may need to use
402
  // 'CalleeDecl' instead.
403

404
  CGCallee Callee;
405
  if (UseVirtualCall) {
406
    Callee = CGCallee::forVirtual(CE, MD, This.getAddress(), Ty);
407
  } else {
408
    if (SanOpts.has(SanitizerKind::CFINVCall) &&
409
        MD->getParent()->isDynamicClass()) {
410
      llvm::Value *VTable;
411
      const CXXRecordDecl *RD;
412
      std::tie(VTable, RD) = CGM.getCXXABI().LoadVTablePtr(
413
          *this, This.getAddress(), CalleeDecl->getParent());
414
      EmitVTablePtrCheckForCall(RD, VTable, CFITCK_NVCall, CE->getBeginLoc());
415
    }
416

417
    if (getLangOpts().AppleKext && MD->isVirtual() && HasQualifier)
418
      Callee = BuildAppleKextVirtualCall(MD, Qualifier, Ty);
419
    else if (!DevirtualizedMethod)
420
      Callee =
421
          CGCallee::forDirect(CGM.GetAddrOfFunction(MD, Ty), GlobalDecl(MD));
422
    else {
423
      Callee =
424
          CGCallee::forDirect(CGM.GetAddrOfFunction(DevirtualizedMethod, Ty),
425
                              GlobalDecl(DevirtualizedMethod));
426
    }
427
  }
428

429
  if (MD->isVirtual()) {
430
    Address NewThisAddr =
431
        CGM.getCXXABI().adjustThisArgumentForVirtualFunctionCall(
432
            *this, CalleeDecl, This.getAddress(), UseVirtualCall);
433
    This.setAddress(NewThisAddr);
434
  }
435

436
  return EmitCXXMemberOrOperatorCall(
437
      CalleeDecl, Callee, ReturnValue, This.getPointer(*this),
438
      /*ImplicitParam=*/nullptr, QualType(), CE, RtlArgs);
439
}
440

441
RValue
442
CodeGenFunction::EmitCXXMemberPointerCallExpr(const CXXMemberCallExpr *E,
443
                                              ReturnValueSlot ReturnValue) {
444
  const BinaryOperator *BO =
445
      cast<BinaryOperator>(E->getCallee()->IgnoreParens());
446
  const Expr *BaseExpr = BO->getLHS();
447
  const Expr *MemFnExpr = BO->getRHS();
448

449
  const auto *MPT = MemFnExpr->getType()->castAs<MemberPointerType>();
450
  const auto *FPT = MPT->getPointeeType()->castAs<FunctionProtoType>();
451
  const auto *RD =
452
      cast<CXXRecordDecl>(MPT->getClass()->castAs<RecordType>()->getDecl());
453

454
  // Emit the 'this' pointer.
455
  Address This = Address::invalid();
456
  if (BO->getOpcode() == BO_PtrMemI)
457
    This = EmitPointerWithAlignment(BaseExpr, nullptr, nullptr, KnownNonNull);
458
  else
459
    This = EmitLValue(BaseExpr, KnownNonNull).getAddress();
460

461
  EmitTypeCheck(TCK_MemberCall, E->getExprLoc(), This.emitRawPointer(*this),
462
                QualType(MPT->getClass(), 0));
463

464
  // Get the member function pointer.
465
  llvm::Value *MemFnPtr = EmitScalarExpr(MemFnExpr);
466

467
  // Ask the ABI to load the callee.  Note that This is modified.
468
  llvm::Value *ThisPtrForCall = nullptr;
469
  CGCallee Callee =
470
    CGM.getCXXABI().EmitLoadOfMemberFunctionPointer(*this, BO, This,
471
                                             ThisPtrForCall, MemFnPtr, MPT);
472

473
  CallArgList Args;
474

475
  QualType ThisType =
476
    getContext().getPointerType(getContext().getTagDeclType(RD));
477

478
  // Push the this ptr.
479
  Args.add(RValue::get(ThisPtrForCall), ThisType);
480

481
  RequiredArgs required = RequiredArgs::forPrototypePlus(FPT, 1);
482

483
  // And the rest of the call args
484
  EmitCallArgs(Args, FPT, E->arguments());
485
  return EmitCall(CGM.getTypes().arrangeCXXMethodCall(Args, FPT, required,
486
                                                      /*PrefixSize=*/0),
487
                  Callee, ReturnValue, Args, nullptr, E == MustTailCall,
488
                  E->getExprLoc());
489
}
490

491
RValue
492
CodeGenFunction::EmitCXXOperatorMemberCallExpr(const CXXOperatorCallExpr *E,
493
                                               const CXXMethodDecl *MD,
494
                                               ReturnValueSlot ReturnValue) {
495
  assert(MD->isImplicitObjectMemberFunction() &&
496
         "Trying to emit a member call expr on a static method!");
497
  return EmitCXXMemberOrOperatorMemberCallExpr(
498
      E, MD, ReturnValue, /*HasQualifier=*/false, /*Qualifier=*/nullptr,
499
      /*IsArrow=*/false, E->getArg(0));
500
}
501

502
RValue CodeGenFunction::EmitCUDAKernelCallExpr(const CUDAKernelCallExpr *E,
503
                                               ReturnValueSlot ReturnValue) {
504
  return CGM.getCUDARuntime().EmitCUDAKernelCallExpr(*this, E, ReturnValue);
505
}
506

507
static void EmitNullBaseClassInitialization(CodeGenFunction &CGF,
508
                                            Address DestPtr,
509
                                            const CXXRecordDecl *Base) {
510
  if (Base->isEmpty())
511
    return;
512

513
  DestPtr = DestPtr.withElementType(CGF.Int8Ty);
514

515
  const ASTRecordLayout &Layout = CGF.getContext().getASTRecordLayout(Base);
516
  CharUnits NVSize = Layout.getNonVirtualSize();
517

518
  // We cannot simply zero-initialize the entire base sub-object if vbptrs are
519
  // present, they are initialized by the most derived class before calling the
520
  // constructor.
521
  SmallVector<std::pair<CharUnits, CharUnits>, 1> Stores;
522
  Stores.emplace_back(CharUnits::Zero(), NVSize);
523

524
  // Each store is split by the existence of a vbptr.
525
  CharUnits VBPtrWidth = CGF.getPointerSize();
526
  std::vector<CharUnits> VBPtrOffsets =
527
      CGF.CGM.getCXXABI().getVBPtrOffsets(Base);
528
  for (CharUnits VBPtrOffset : VBPtrOffsets) {
529
    // Stop before we hit any virtual base pointers located in virtual bases.
530
    if (VBPtrOffset >= NVSize)
531
      break;
532
    std::pair<CharUnits, CharUnits> LastStore = Stores.pop_back_val();
533
    CharUnits LastStoreOffset = LastStore.first;
534
    CharUnits LastStoreSize = LastStore.second;
535

536
    CharUnits SplitBeforeOffset = LastStoreOffset;
537
    CharUnits SplitBeforeSize = VBPtrOffset - SplitBeforeOffset;
538
    assert(!SplitBeforeSize.isNegative() && "negative store size!");
539
    if (!SplitBeforeSize.isZero())
540
      Stores.emplace_back(SplitBeforeOffset, SplitBeforeSize);
541

542
    CharUnits SplitAfterOffset = VBPtrOffset + VBPtrWidth;
543
    CharUnits SplitAfterSize = LastStoreSize - SplitAfterOffset;
544
    assert(!SplitAfterSize.isNegative() && "negative store size!");
545
    if (!SplitAfterSize.isZero())
546
      Stores.emplace_back(SplitAfterOffset, SplitAfterSize);
547
  }
548

549
  // If the type contains a pointer to data member we can't memset it to zero.
550
  // Instead, create a null constant and copy it to the destination.
551
  // TODO: there are other patterns besides zero that we can usefully memset,
552
  // like -1, which happens to be the pattern used by member-pointers.
553
  // TODO: isZeroInitializable can be over-conservative in the case where a
554
  // virtual base contains a member pointer.
555
  llvm::Constant *NullConstantForBase = CGF.CGM.EmitNullConstantForBase(Base);
556
  if (!NullConstantForBase->isNullValue()) {
557
    llvm::GlobalVariable *NullVariable = new llvm::GlobalVariable(
558
        CGF.CGM.getModule(), NullConstantForBase->getType(),
559
        /*isConstant=*/true, llvm::GlobalVariable::PrivateLinkage,
560
        NullConstantForBase, Twine());
561

562
    CharUnits Align =
563
        std::max(Layout.getNonVirtualAlignment(), DestPtr.getAlignment());
564
    NullVariable->setAlignment(Align.getAsAlign());
565

566
    Address SrcPtr(NullVariable, CGF.Int8Ty, Align);
567

568
    // Get and call the appropriate llvm.memcpy overload.
569
    for (std::pair<CharUnits, CharUnits> Store : Stores) {
570
      CharUnits StoreOffset = Store.first;
571
      CharUnits StoreSize = Store.second;
572
      llvm::Value *StoreSizeVal = CGF.CGM.getSize(StoreSize);
573
      CGF.Builder.CreateMemCpy(
574
          CGF.Builder.CreateConstInBoundsByteGEP(DestPtr, StoreOffset),
575
          CGF.Builder.CreateConstInBoundsByteGEP(SrcPtr, StoreOffset),
576
          StoreSizeVal);
577
    }
578

579
  // Otherwise, just memset the whole thing to zero.  This is legal
580
  // because in LLVM, all default initializers (other than the ones we just
581
  // handled above) are guaranteed to have a bit pattern of all zeros.
582
  } else {
583
    for (std::pair<CharUnits, CharUnits> Store : Stores) {
584
      CharUnits StoreOffset = Store.first;
585
      CharUnits StoreSize = Store.second;
586
      llvm::Value *StoreSizeVal = CGF.CGM.getSize(StoreSize);
587
      CGF.Builder.CreateMemSet(
588
          CGF.Builder.CreateConstInBoundsByteGEP(DestPtr, StoreOffset),
589
          CGF.Builder.getInt8(0), StoreSizeVal);
590
    }
591
  }
592
}
593

594
void
595
CodeGenFunction::EmitCXXConstructExpr(const CXXConstructExpr *E,
596
                                      AggValueSlot Dest) {
597
  assert(!Dest.isIgnored() && "Must have a destination!");
598
  const CXXConstructorDecl *CD = E->getConstructor();
599

600
  // If we require zero initialization before (or instead of) calling the
601
  // constructor, as can be the case with a non-user-provided default
602
  // constructor, emit the zero initialization now, unless destination is
603
  // already zeroed.
604
  if (E->requiresZeroInitialization() && !Dest.isZeroed()) {
605
    switch (E->getConstructionKind()) {
606
    case CXXConstructionKind::Delegating:
607
    case CXXConstructionKind::Complete:
608
      EmitNullInitialization(Dest.getAddress(), E->getType());
609
      break;
610
    case CXXConstructionKind::VirtualBase:
611
    case CXXConstructionKind::NonVirtualBase:
612
      EmitNullBaseClassInitialization(*this, Dest.getAddress(),
613
                                      CD->getParent());
614
      break;
615
    }
616
  }
617

618
  // If this is a call to a trivial default constructor, do nothing.
619
  if (CD->isTrivial() && CD->isDefaultConstructor())
620
    return;
621

622
  // Elide the constructor if we're constructing from a temporary.
623
  if (getLangOpts().ElideConstructors && E->isElidable()) {
624
    // FIXME: This only handles the simplest case, where the source object
625
    //        is passed directly as the first argument to the constructor.
626
    //        This should also handle stepping though implicit casts and
627
    //        conversion sequences which involve two steps, with a
628
    //        conversion operator followed by a converting constructor.
629
    const Expr *SrcObj = E->getArg(0);
630
    assert(SrcObj->isTemporaryObject(getContext(), CD->getParent()));
631
    assert(
632
        getContext().hasSameUnqualifiedType(E->getType(), SrcObj->getType()));
633
    EmitAggExpr(SrcObj, Dest);
634
    return;
635
  }
636

637
  if (const ArrayType *arrayType
638
        = getContext().getAsArrayType(E->getType())) {
639
    EmitCXXAggrConstructorCall(CD, arrayType, Dest.getAddress(), E,
640
                               Dest.isSanitizerChecked());
641
  } else {
642
    CXXCtorType Type = Ctor_Complete;
643
    bool ForVirtualBase = false;
644
    bool Delegating = false;
645

646
    switch (E->getConstructionKind()) {
647
    case CXXConstructionKind::Delegating:
648
      // We should be emitting a constructor; GlobalDecl will assert this
649
      Type = CurGD.getCtorType();
650
      Delegating = true;
651
      break;
652

653
    case CXXConstructionKind::Complete:
654
      Type = Ctor_Complete;
655
      break;
656

657
    case CXXConstructionKind::VirtualBase:
658
      ForVirtualBase = true;
659
      [[fallthrough]];
660

661
    case CXXConstructionKind::NonVirtualBase:
662
      Type = Ctor_Base;
663
     }
664

665
     // Call the constructor.
666
     EmitCXXConstructorCall(CD, Type, ForVirtualBase, Delegating, Dest, E);
667
  }
668
}
669

670
void CodeGenFunction::EmitSynthesizedCXXCopyCtor(Address Dest, Address Src,
671
                                                 const Expr *Exp) {
672
  if (const ExprWithCleanups *E = dyn_cast<ExprWithCleanups>(Exp))
673
    Exp = E->getSubExpr();
674
  assert(isa<CXXConstructExpr>(Exp) &&
675
         "EmitSynthesizedCXXCopyCtor - unknown copy ctor expr");
676
  const CXXConstructExpr* E = cast<CXXConstructExpr>(Exp);
677
  const CXXConstructorDecl *CD = E->getConstructor();
678
  RunCleanupsScope Scope(*this);
679

680
  // If we require zero initialization before (or instead of) calling the
681
  // constructor, as can be the case with a non-user-provided default
682
  // constructor, emit the zero initialization now.
683
  // FIXME. Do I still need this for a copy ctor synthesis?
684
  if (E->requiresZeroInitialization())
685
    EmitNullInitialization(Dest, E->getType());
686

687
  assert(!getContext().getAsConstantArrayType(E->getType())
688
         && "EmitSynthesizedCXXCopyCtor - Copied-in Array");
689
  EmitSynthesizedCXXCopyCtorCall(CD, Dest, Src, E);
690
}
691

692
static CharUnits CalculateCookiePadding(CodeGenFunction &CGF,
693
                                        const CXXNewExpr *E) {
694
  if (!E->isArray())
695
    return CharUnits::Zero();
696

697
  // No cookie is required if the operator new[] being used is the
698
  // reserved placement operator new[].
699
  if (E->getOperatorNew()->isReservedGlobalPlacementOperator())
700
    return CharUnits::Zero();
701

702
  return CGF.CGM.getCXXABI().GetArrayCookieSize(E);
703
}
704

705
static llvm::Value *EmitCXXNewAllocSize(CodeGenFunction &CGF,
706
                                        const CXXNewExpr *e,
707
                                        unsigned minElements,
708
                                        llvm::Value *&numElements,
709
                                        llvm::Value *&sizeWithoutCookie) {
710
  QualType type = e->getAllocatedType();
711

712
  if (!e->isArray()) {
713
    CharUnits typeSize = CGF.getContext().getTypeSizeInChars(type);
714
    sizeWithoutCookie
715
      = llvm::ConstantInt::get(CGF.SizeTy, typeSize.getQuantity());
716
    return sizeWithoutCookie;
717
  }
718

719
  // The width of size_t.
720
  unsigned sizeWidth = CGF.SizeTy->getBitWidth();
721

722
  // Figure out the cookie size.
723
  llvm::APInt cookieSize(sizeWidth,
724
                         CalculateCookiePadding(CGF, e).getQuantity());
725

726
  // Emit the array size expression.
727
  // We multiply the size of all dimensions for NumElements.
728
  // e.g for 'int[2][3]', ElemType is 'int' and NumElements is 6.
729
  numElements =
730
    ConstantEmitter(CGF).tryEmitAbstract(*e->getArraySize(), e->getType());
731
  if (!numElements)
732
    numElements = CGF.EmitScalarExpr(*e->getArraySize());
733
  assert(isa<llvm::IntegerType>(numElements->getType()));
734

735
  // The number of elements can be have an arbitrary integer type;
736
  // essentially, we need to multiply it by a constant factor, add a
737
  // cookie size, and verify that the result is representable as a
738
  // size_t.  That's just a gloss, though, and it's wrong in one
739
  // important way: if the count is negative, it's an error even if
740
  // the cookie size would bring the total size >= 0.
741
  bool isSigned
742
    = (*e->getArraySize())->getType()->isSignedIntegerOrEnumerationType();
743
  llvm::IntegerType *numElementsType
744
    = cast<llvm::IntegerType>(numElements->getType());
745
  unsigned numElementsWidth = numElementsType->getBitWidth();
746

747
  // Compute the constant factor.
748
  llvm::APInt arraySizeMultiplier(sizeWidth, 1);
749
  while (const ConstantArrayType *CAT
750
             = CGF.getContext().getAsConstantArrayType(type)) {
751
    type = CAT->getElementType();
752
    arraySizeMultiplier *= CAT->getSize();
753
  }
754

755
  CharUnits typeSize = CGF.getContext().getTypeSizeInChars(type);
756
  llvm::APInt typeSizeMultiplier(sizeWidth, typeSize.getQuantity());
757
  typeSizeMultiplier *= arraySizeMultiplier;
758

759
  // This will be a size_t.
760
  llvm::Value *size;
761

762
  // If someone is doing 'new int[42]' there is no need to do a dynamic check.
763
  // Don't bloat the -O0 code.
764
  if (llvm::ConstantInt *numElementsC =
765
        dyn_cast<llvm::ConstantInt>(numElements)) {
766
    const llvm::APInt &count = numElementsC->getValue();
767

768
    bool hasAnyOverflow = false;
769

770
    // If 'count' was a negative number, it's an overflow.
771
    if (isSigned && count.isNegative())
772
      hasAnyOverflow = true;
773

774
    // We want to do all this arithmetic in size_t.  If numElements is
775
    // wider than that, check whether it's already too big, and if so,
776
    // overflow.
777
    else if (numElementsWidth > sizeWidth &&
778
             numElementsWidth - sizeWidth > count.countl_zero())
779
      hasAnyOverflow = true;
780

781
    // Okay, compute a count at the right width.
782
    llvm::APInt adjustedCount = count.zextOrTrunc(sizeWidth);
783

784
    // If there is a brace-initializer, we cannot allocate fewer elements than
785
    // there are initializers. If we do, that's treated like an overflow.
786
    if (adjustedCount.ult(minElements))
787
      hasAnyOverflow = true;
788

789
    // Scale numElements by that.  This might overflow, but we don't
790
    // care because it only overflows if allocationSize does, too, and
791
    // if that overflows then we shouldn't use this.
792
    numElements = llvm::ConstantInt::get(CGF.SizeTy,
793
                                         adjustedCount * arraySizeMultiplier);
794

795
    // Compute the size before cookie, and track whether it overflowed.
796
    bool overflow;
797
    llvm::APInt allocationSize
798
      = adjustedCount.umul_ov(typeSizeMultiplier, overflow);
799
    hasAnyOverflow |= overflow;
800

801
    // Add in the cookie, and check whether it's overflowed.
802
    if (cookieSize != 0) {
803
      // Save the current size without a cookie.  This shouldn't be
804
      // used if there was overflow.
805
      sizeWithoutCookie = llvm::ConstantInt::get(CGF.SizeTy, allocationSize);
806

807
      allocationSize = allocationSize.uadd_ov(cookieSize, overflow);
808
      hasAnyOverflow |= overflow;
809
    }
810

811
    // On overflow, produce a -1 so operator new will fail.
812
    if (hasAnyOverflow) {
813
      size = llvm::Constant::getAllOnesValue(CGF.SizeTy);
814
    } else {
815
      size = llvm::ConstantInt::get(CGF.SizeTy, allocationSize);
816
    }
817

818
  // Otherwise, we might need to use the overflow intrinsics.
819
  } else {
820
    // There are up to five conditions we need to test for:
821
    // 1) if isSigned, we need to check whether numElements is negative;
822
    // 2) if numElementsWidth > sizeWidth, we need to check whether
823
    //   numElements is larger than something representable in size_t;
824
    // 3) if minElements > 0, we need to check whether numElements is smaller
825
    //    than that.
826
    // 4) we need to compute
827
    //      sizeWithoutCookie := numElements * typeSizeMultiplier
828
    //    and check whether it overflows; and
829
    // 5) if we need a cookie, we need to compute
830
    //      size := sizeWithoutCookie + cookieSize
831
    //    and check whether it overflows.
832

833
    llvm::Value *hasOverflow = nullptr;
834

835
    // If numElementsWidth > sizeWidth, then one way or another, we're
836
    // going to have to do a comparison for (2), and this happens to
837
    // take care of (1), too.
838
    if (numElementsWidth > sizeWidth) {
839
      llvm::APInt threshold =
840
          llvm::APInt::getOneBitSet(numElementsWidth, sizeWidth);
841

842
      llvm::Value *thresholdV
843
        = llvm::ConstantInt::get(numElementsType, threshold);
844

845
      hasOverflow = CGF.Builder.CreateICmpUGE(numElements, thresholdV);
846
      numElements = CGF.Builder.CreateTrunc(numElements, CGF.SizeTy);
847

848
    // Otherwise, if we're signed, we want to sext up to size_t.
849
    } else if (isSigned) {
850
      if (numElementsWidth < sizeWidth)
851
        numElements = CGF.Builder.CreateSExt(numElements, CGF.SizeTy);
852

853
      // If there's a non-1 type size multiplier, then we can do the
854
      // signedness check at the same time as we do the multiply
855
      // because a negative number times anything will cause an
856
      // unsigned overflow.  Otherwise, we have to do it here. But at least
857
      // in this case, we can subsume the >= minElements check.
858
      if (typeSizeMultiplier == 1)
859
        hasOverflow = CGF.Builder.CreateICmpSLT(numElements,
860
                              llvm::ConstantInt::get(CGF.SizeTy, minElements));
861

862
    // Otherwise, zext up to size_t if necessary.
863
    } else if (numElementsWidth < sizeWidth) {
864
      numElements = CGF.Builder.CreateZExt(numElements, CGF.SizeTy);
865
    }
866

867
    assert(numElements->getType() == CGF.SizeTy);
868

869
    if (minElements) {
870
      // Don't allow allocation of fewer elements than we have initializers.
871
      if (!hasOverflow) {
872
        hasOverflow = CGF.Builder.CreateICmpULT(numElements,
873
                              llvm::ConstantInt::get(CGF.SizeTy, minElements));
874
      } else if (numElementsWidth > sizeWidth) {
875
        // The other existing overflow subsumes this check.
876
        // We do an unsigned comparison, since any signed value < -1 is
877
        // taken care of either above or below.
878
        hasOverflow = CGF.Builder.CreateOr(hasOverflow,
879
                          CGF.Builder.CreateICmpULT(numElements,
880
                              llvm::ConstantInt::get(CGF.SizeTy, minElements)));
881
      }
882
    }
883

884
    size = numElements;
885

886
    // Multiply by the type size if necessary.  This multiplier
887
    // includes all the factors for nested arrays.
888
    //
889
    // This step also causes numElements to be scaled up by the
890
    // nested-array factor if necessary.  Overflow on this computation
891
    // can be ignored because the result shouldn't be used if
892
    // allocation fails.
893
    if (typeSizeMultiplier != 1) {
894
      llvm::Function *umul_with_overflow
895
        = CGF.CGM.getIntrinsic(llvm::Intrinsic::umul_with_overflow, CGF.SizeTy);
896

897
      llvm::Value *tsmV =
898
        llvm::ConstantInt::get(CGF.SizeTy, typeSizeMultiplier);
899
      llvm::Value *result =
900
          CGF.Builder.CreateCall(umul_with_overflow, {size, tsmV});
901

902
      llvm::Value *overflowed = CGF.Builder.CreateExtractValue(result, 1);
903
      if (hasOverflow)
904
        hasOverflow = CGF.Builder.CreateOr(hasOverflow, overflowed);
905
      else
906
        hasOverflow = overflowed;
907

908
      size = CGF.Builder.CreateExtractValue(result, 0);
909

910
      // Also scale up numElements by the array size multiplier.
911
      if (arraySizeMultiplier != 1) {
912
        // If the base element type size is 1, then we can re-use the
913
        // multiply we just did.
914
        if (typeSize.isOne()) {
915
          assert(arraySizeMultiplier == typeSizeMultiplier);
916
          numElements = size;
917

918
        // Otherwise we need a separate multiply.
919
        } else {
920
          llvm::Value *asmV =
921
            llvm::ConstantInt::get(CGF.SizeTy, arraySizeMultiplier);
922
          numElements = CGF.Builder.CreateMul(numElements, asmV);
923
        }
924
      }
925
    } else {
926
      // numElements doesn't need to be scaled.
927
      assert(arraySizeMultiplier == 1);
928
    }
929

930
    // Add in the cookie size if necessary.
931
    if (cookieSize != 0) {
932
      sizeWithoutCookie = size;
933

934
      llvm::Function *uadd_with_overflow
935
        = CGF.CGM.getIntrinsic(llvm::Intrinsic::uadd_with_overflow, CGF.SizeTy);
936

937
      llvm::Value *cookieSizeV = llvm::ConstantInt::get(CGF.SizeTy, cookieSize);
938
      llvm::Value *result =
939
          CGF.Builder.CreateCall(uadd_with_overflow, {size, cookieSizeV});
940

941
      llvm::Value *overflowed = CGF.Builder.CreateExtractValue(result, 1);
942
      if (hasOverflow)
943
        hasOverflow = CGF.Builder.CreateOr(hasOverflow, overflowed);
944
      else
945
        hasOverflow = overflowed;
946

947
      size = CGF.Builder.CreateExtractValue(result, 0);
948
    }
949

950
    // If we had any possibility of dynamic overflow, make a select to
951
    // overwrite 'size' with an all-ones value, which should cause
952
    // operator new to throw.
953
    if (hasOverflow)
954
      size = CGF.Builder.CreateSelect(hasOverflow,
955
                                 llvm::Constant::getAllOnesValue(CGF.SizeTy),
956
                                      size);
957
  }
958

959
  if (cookieSize == 0)
960
    sizeWithoutCookie = size;
961
  else
962
    assert(sizeWithoutCookie && "didn't set sizeWithoutCookie?");
963

964
  return size;
965
}
966

967
static void StoreAnyExprIntoOneUnit(CodeGenFunction &CGF, const Expr *Init,
968
                                    QualType AllocType, Address NewPtr,
969
                                    AggValueSlot::Overlap_t MayOverlap) {
970
  // FIXME: Refactor with EmitExprAsInit.
971
  switch (CGF.getEvaluationKind(AllocType)) {
972
  case TEK_Scalar:
973
    CGF.EmitScalarInit(Init, nullptr,
974
                       CGF.MakeAddrLValue(NewPtr, AllocType), false);
975
    return;
976
  case TEK_Complex:
977
    CGF.EmitComplexExprIntoLValue(Init, CGF.MakeAddrLValue(NewPtr, AllocType),
978
                                  /*isInit*/ true);
979
    return;
980
  case TEK_Aggregate: {
981
    AggValueSlot Slot
982
      = AggValueSlot::forAddr(NewPtr, AllocType.getQualifiers(),
983
                              AggValueSlot::IsDestructed,
984
                              AggValueSlot::DoesNotNeedGCBarriers,
985
                              AggValueSlot::IsNotAliased,
986
                              MayOverlap, AggValueSlot::IsNotZeroed,
987
                              AggValueSlot::IsSanitizerChecked);
988
    CGF.EmitAggExpr(Init, Slot);
989
    return;
990
  }
991
  }
992
  llvm_unreachable("bad evaluation kind");
993
}
994

995
void CodeGenFunction::EmitNewArrayInitializer(
996
    const CXXNewExpr *E, QualType ElementType, llvm::Type *ElementTy,
997
    Address BeginPtr, llvm::Value *NumElements,
998
    llvm::Value *AllocSizeWithoutCookie) {
999
  // If we have a type with trivial initialization and no initializer,
1000
  // there's nothing to do.
1001
  if (!E->hasInitializer())
1002
    return;
1003

1004
  Address CurPtr = BeginPtr;
1005

1006
  unsigned InitListElements = 0;
1007

1008
  const Expr *Init = E->getInitializer();
1009
  Address EndOfInit = Address::invalid();
1010
  QualType::DestructionKind DtorKind = ElementType.isDestructedType();
1011
  CleanupDeactivationScope deactivation(*this);
1012
  bool pushedCleanup = false;
1013

1014
  CharUnits ElementSize = getContext().getTypeSizeInChars(ElementType);
1015
  CharUnits ElementAlign =
1016
    BeginPtr.getAlignment().alignmentOfArrayElement(ElementSize);
1017

1018
  // Attempt to perform zero-initialization using memset.
1019
  auto TryMemsetInitialization = [&]() -> bool {
1020
    // FIXME: If the type is a pointer-to-data-member under the Itanium ABI,
1021
    // we can initialize with a memset to -1.
1022
    if (!CGM.getTypes().isZeroInitializable(ElementType))
1023
      return false;
1024

1025
    // Optimization: since zero initialization will just set the memory
1026
    // to all zeroes, generate a single memset to do it in one shot.
1027

1028
    // Subtract out the size of any elements we've already initialized.
1029
    auto *RemainingSize = AllocSizeWithoutCookie;
1030
    if (InitListElements) {
1031
      // We know this can't overflow; we check this when doing the allocation.
1032
      auto *InitializedSize = llvm::ConstantInt::get(
1033
          RemainingSize->getType(),
1034
          getContext().getTypeSizeInChars(ElementType).getQuantity() *
1035
              InitListElements);
1036
      RemainingSize = Builder.CreateSub(RemainingSize, InitializedSize);
1037
    }
1038

1039
    // Create the memset.
1040
    Builder.CreateMemSet(CurPtr, Builder.getInt8(0), RemainingSize, false);
1041
    return true;
1042
  };
1043

1044
  const InitListExpr *ILE = dyn_cast<InitListExpr>(Init);
1045
  const CXXParenListInitExpr *CPLIE = nullptr;
1046
  const StringLiteral *SL = nullptr;
1047
  const ObjCEncodeExpr *OCEE = nullptr;
1048
  const Expr *IgnoreParen = nullptr;
1049
  if (!ILE) {
1050
    IgnoreParen = Init->IgnoreParenImpCasts();
1051
    CPLIE = dyn_cast<CXXParenListInitExpr>(IgnoreParen);
1052
    SL = dyn_cast<StringLiteral>(IgnoreParen);
1053
    OCEE = dyn_cast<ObjCEncodeExpr>(IgnoreParen);
1054
  }
1055

1056
  // If the initializer is an initializer list, first do the explicit elements.
1057
  if (ILE || CPLIE || SL || OCEE) {
1058
    // Initializing from a (braced) string literal is a special case; the init
1059
    // list element does not initialize a (single) array element.
1060
    if ((ILE && ILE->isStringLiteralInit()) || SL || OCEE) {
1061
      if (!ILE)
1062
        Init = IgnoreParen;
1063
      // Initialize the initial portion of length equal to that of the string
1064
      // literal. The allocation must be for at least this much; we emitted a
1065
      // check for that earlier.
1066
      AggValueSlot Slot =
1067
          AggValueSlot::forAddr(CurPtr, ElementType.getQualifiers(),
1068
                                AggValueSlot::IsDestructed,
1069
                                AggValueSlot::DoesNotNeedGCBarriers,
1070
                                AggValueSlot::IsNotAliased,
1071
                                AggValueSlot::DoesNotOverlap,
1072
                                AggValueSlot::IsNotZeroed,
1073
                                AggValueSlot::IsSanitizerChecked);
1074
      EmitAggExpr(ILE ? ILE->getInit(0) : Init, Slot);
1075

1076
      // Move past these elements.
1077
      InitListElements =
1078
          cast<ConstantArrayType>(Init->getType()->getAsArrayTypeUnsafe())
1079
              ->getZExtSize();
1080
      CurPtr = Builder.CreateConstInBoundsGEP(
1081
          CurPtr, InitListElements, "string.init.end");
1082

1083
      // Zero out the rest, if any remain.
1084
      llvm::ConstantInt *ConstNum = dyn_cast<llvm::ConstantInt>(NumElements);
1085
      if (!ConstNum || !ConstNum->equalsInt(InitListElements)) {
1086
        bool OK = TryMemsetInitialization();
1087
        (void)OK;
1088
        assert(OK && "couldn't memset character type?");
1089
      }
1090
      return;
1091
    }
1092

1093
    ArrayRef<const Expr *> InitExprs =
1094
        ILE ? ILE->inits() : CPLIE->getInitExprs();
1095
    InitListElements = InitExprs.size();
1096

1097
    // If this is a multi-dimensional array new, we will initialize multiple
1098
    // elements with each init list element.
1099
    QualType AllocType = E->getAllocatedType();
1100
    if (const ConstantArrayType *CAT = dyn_cast_or_null<ConstantArrayType>(
1101
            AllocType->getAsArrayTypeUnsafe())) {
1102
      ElementTy = ConvertTypeForMem(AllocType);
1103
      CurPtr = CurPtr.withElementType(ElementTy);
1104
      InitListElements *= getContext().getConstantArrayElementCount(CAT);
1105
    }
1106

1107
    // Enter a partial-destruction Cleanup if necessary.
1108
    if (DtorKind) {
1109
      AllocaTrackerRAII AllocaTracker(*this);
1110
      // In principle we could tell the Cleanup where we are more
1111
      // directly, but the control flow can get so varied here that it
1112
      // would actually be quite complex.  Therefore we go through an
1113
      // alloca.
1114
      llvm::Instruction *DominatingIP =
1115
          Builder.CreateFlagLoad(llvm::ConstantInt::getNullValue(Int8PtrTy));
1116
      EndOfInit = CreateTempAlloca(BeginPtr.getType(), getPointerAlign(),
1117
                                   "array.init.end");
1118
      pushIrregularPartialArrayCleanup(BeginPtr.emitRawPointer(*this),
1119
                                       EndOfInit, ElementType, ElementAlign,
1120
                                       getDestroyer(DtorKind));
1121
      cast<EHCleanupScope>(*EHStack.find(EHStack.stable_begin()))
1122
          .AddAuxAllocas(AllocaTracker.Take());
1123
      DeferredDeactivationCleanupStack.push_back(
1124
          {EHStack.stable_begin(), DominatingIP});
1125
      pushedCleanup = true;
1126
    }
1127

1128
    CharUnits StartAlign = CurPtr.getAlignment();
1129
    unsigned i = 0;
1130
    for (const Expr *IE : InitExprs) {
1131
      // Tell the cleanup that it needs to destroy up to this
1132
      // element.  TODO: some of these stores can be trivially
1133
      // observed to be unnecessary.
1134
      if (EndOfInit.isValid()) {
1135
        Builder.CreateStore(CurPtr.emitRawPointer(*this), EndOfInit);
1136
      }
1137
      // FIXME: If the last initializer is an incomplete initializer list for
1138
      // an array, and we have an array filler, we can fold together the two
1139
      // initialization loops.
1140
      StoreAnyExprIntoOneUnit(*this, IE, IE->getType(), CurPtr,
1141
                              AggValueSlot::DoesNotOverlap);
1142
      CurPtr = Address(Builder.CreateInBoundsGEP(CurPtr.getElementType(),
1143
                                                 CurPtr.emitRawPointer(*this),
1144
                                                 Builder.getSize(1),
1145
                                                 "array.exp.next"),
1146
                       CurPtr.getElementType(),
1147
                       StartAlign.alignmentAtOffset((++i) * ElementSize));
1148
    }
1149

1150
    // The remaining elements are filled with the array filler expression.
1151
    Init = ILE ? ILE->getArrayFiller() : CPLIE->getArrayFiller();
1152

1153
    // Extract the initializer for the individual array elements by pulling
1154
    // out the array filler from all the nested initializer lists. This avoids
1155
    // generating a nested loop for the initialization.
1156
    while (Init && Init->getType()->isConstantArrayType()) {
1157
      auto *SubILE = dyn_cast<InitListExpr>(Init);
1158
      if (!SubILE)
1159
        break;
1160
      assert(SubILE->getNumInits() == 0 && "explicit inits in array filler?");
1161
      Init = SubILE->getArrayFiller();
1162
    }
1163

1164
    // Switch back to initializing one base element at a time.
1165
    CurPtr = CurPtr.withElementType(BeginPtr.getElementType());
1166
  }
1167

1168
  // If all elements have already been initialized, skip any further
1169
  // initialization.
1170
  llvm::ConstantInt *ConstNum = dyn_cast<llvm::ConstantInt>(NumElements);
1171
  if (ConstNum && ConstNum->getZExtValue() <= InitListElements) {
1172
    return;
1173
  }
1174

1175
  assert(Init && "have trailing elements to initialize but no initializer");
1176

1177
  // If this is a constructor call, try to optimize it out, and failing that
1178
  // emit a single loop to initialize all remaining elements.
1179
  if (const CXXConstructExpr *CCE = dyn_cast<CXXConstructExpr>(Init)) {
1180
    CXXConstructorDecl *Ctor = CCE->getConstructor();
1181
    if (Ctor->isTrivial()) {
1182
      // If new expression did not specify value-initialization, then there
1183
      // is no initialization.
1184
      if (!CCE->requiresZeroInitialization() || Ctor->getParent()->isEmpty())
1185
        return;
1186

1187
      if (TryMemsetInitialization())
1188
        return;
1189
    }
1190

1191
    // Store the new Cleanup position for irregular Cleanups.
1192
    //
1193
    // FIXME: Share this cleanup with the constructor call emission rather than
1194
    // having it create a cleanup of its own.
1195
    if (EndOfInit.isValid())
1196
      Builder.CreateStore(CurPtr.emitRawPointer(*this), EndOfInit);
1197

1198
    // Emit a constructor call loop to initialize the remaining elements.
1199
    if (InitListElements)
1200
      NumElements = Builder.CreateSub(
1201
          NumElements,
1202
          llvm::ConstantInt::get(NumElements->getType(), InitListElements));
1203
    EmitCXXAggrConstructorCall(Ctor, NumElements, CurPtr, CCE,
1204
                               /*NewPointerIsChecked*/true,
1205
                               CCE->requiresZeroInitialization());
1206
    return;
1207
  }
1208

1209
  // If this is value-initialization, we can usually use memset.
1210
  ImplicitValueInitExpr IVIE(ElementType);
1211
  if (isa<ImplicitValueInitExpr>(Init)) {
1212
    if (TryMemsetInitialization())
1213
      return;
1214

1215
    // Switch to an ImplicitValueInitExpr for the element type. This handles
1216
    // only one case: multidimensional array new of pointers to members. In
1217
    // all other cases, we already have an initializer for the array element.
1218
    Init = &IVIE;
1219
  }
1220

1221
  // At this point we should have found an initializer for the individual
1222
  // elements of the array.
1223
  assert(getContext().hasSameUnqualifiedType(ElementType, Init->getType()) &&
1224
         "got wrong type of element to initialize");
1225

1226
  // If we have an empty initializer list, we can usually use memset.
1227
  if (auto *ILE = dyn_cast<InitListExpr>(Init))
1228
    if (ILE->getNumInits() == 0 && TryMemsetInitialization())
1229
      return;
1230

1231
  // If we have a struct whose every field is value-initialized, we can
1232
  // usually use memset.
1233
  if (auto *ILE = dyn_cast<InitListExpr>(Init)) {
1234
    if (const RecordType *RType = ILE->getType()->getAs<RecordType>()) {
1235
      if (RType->getDecl()->isStruct()) {
1236
        unsigned NumElements = 0;
1237
        if (auto *CXXRD = dyn_cast<CXXRecordDecl>(RType->getDecl()))
1238
          NumElements = CXXRD->getNumBases();
1239
        for (auto *Field : RType->getDecl()->fields())
1240
          if (!Field->isUnnamedBitField())
1241
            ++NumElements;
1242
        // FIXME: Recurse into nested InitListExprs.
1243
        if (ILE->getNumInits() == NumElements)
1244
          for (unsigned i = 0, e = ILE->getNumInits(); i != e; ++i)
1245
            if (!isa<ImplicitValueInitExpr>(ILE->getInit(i)))
1246
              --NumElements;
1247
        if (ILE->getNumInits() == NumElements && TryMemsetInitialization())
1248
          return;
1249
      }
1250
    }
1251
  }
1252

1253
  // Create the loop blocks.
1254
  llvm::BasicBlock *EntryBB = Builder.GetInsertBlock();
1255
  llvm::BasicBlock *LoopBB = createBasicBlock("new.loop");
1256
  llvm::BasicBlock *ContBB = createBasicBlock("new.loop.end");
1257

1258
  // Find the end of the array, hoisted out of the loop.
1259
  llvm::Value *EndPtr = Builder.CreateInBoundsGEP(
1260
      BeginPtr.getElementType(), BeginPtr.emitRawPointer(*this), NumElements,
1261
      "array.end");
1262

1263
  // If the number of elements isn't constant, we have to now check if there is
1264
  // anything left to initialize.
1265
  if (!ConstNum) {
1266
    llvm::Value *IsEmpty = Builder.CreateICmpEQ(CurPtr.emitRawPointer(*this),
1267
                                                EndPtr, "array.isempty");
1268
    Builder.CreateCondBr(IsEmpty, ContBB, LoopBB);
1269
  }
1270

1271
  // Enter the loop.
1272
  EmitBlock(LoopBB);
1273

1274
  // Set up the current-element phi.
1275
  llvm::PHINode *CurPtrPhi =
1276
      Builder.CreatePHI(CurPtr.getType(), 2, "array.cur");
1277
  CurPtrPhi->addIncoming(CurPtr.emitRawPointer(*this), EntryBB);
1278

1279
  CurPtr = Address(CurPtrPhi, CurPtr.getElementType(), ElementAlign);
1280

1281
  // Store the new Cleanup position for irregular Cleanups.
1282
  if (EndOfInit.isValid())
1283
    Builder.CreateStore(CurPtr.emitRawPointer(*this), EndOfInit);
1284

1285
  // Enter a partial-destruction Cleanup if necessary.
1286
  if (!pushedCleanup && needsEHCleanup(DtorKind)) {
1287
    llvm::Instruction *DominatingIP =
1288
        Builder.CreateFlagLoad(llvm::ConstantInt::getNullValue(Int8PtrTy));
1289
    pushRegularPartialArrayCleanup(BeginPtr.emitRawPointer(*this),
1290
                                   CurPtr.emitRawPointer(*this), ElementType,
1291
                                   ElementAlign, getDestroyer(DtorKind));
1292
    DeferredDeactivationCleanupStack.push_back(
1293
        {EHStack.stable_begin(), DominatingIP});
1294
  }
1295

1296
  // Emit the initializer into this element.
1297
  StoreAnyExprIntoOneUnit(*this, Init, Init->getType(), CurPtr,
1298
                          AggValueSlot::DoesNotOverlap);
1299

1300
  // Leave the Cleanup if we entered one.
1301
  deactivation.ForceDeactivate();
1302

1303
  // Advance to the next element by adjusting the pointer type as necessary.
1304
  llvm::Value *NextPtr = Builder.CreateConstInBoundsGEP1_32(
1305
      ElementTy, CurPtr.emitRawPointer(*this), 1, "array.next");
1306

1307
  // Check whether we've gotten to the end of the array and, if so,
1308
  // exit the loop.
1309
  llvm::Value *IsEnd = Builder.CreateICmpEQ(NextPtr, EndPtr, "array.atend");
1310
  Builder.CreateCondBr(IsEnd, ContBB, LoopBB);
1311
  CurPtrPhi->addIncoming(NextPtr, Builder.GetInsertBlock());
1312

1313
  EmitBlock(ContBB);
1314
}
1315

1316
static void EmitNewInitializer(CodeGenFunction &CGF, const CXXNewExpr *E,
1317
                               QualType ElementType, llvm::Type *ElementTy,
1318
                               Address NewPtr, llvm::Value *NumElements,
1319
                               llvm::Value *AllocSizeWithoutCookie) {
1320
  ApplyDebugLocation DL(CGF, E);
1321
  if (E->isArray())
1322
    CGF.EmitNewArrayInitializer(E, ElementType, ElementTy, NewPtr, NumElements,
1323
                                AllocSizeWithoutCookie);
1324
  else if (const Expr *Init = E->getInitializer())
1325
    StoreAnyExprIntoOneUnit(CGF, Init, E->getAllocatedType(), NewPtr,
1326
                            AggValueSlot::DoesNotOverlap);
1327
}
1328

1329
/// Emit a call to an operator new or operator delete function, as implicitly
1330
/// created by new-expressions and delete-expressions.
1331
static RValue EmitNewDeleteCall(CodeGenFunction &CGF,
1332
                                const FunctionDecl *CalleeDecl,
1333
                                const FunctionProtoType *CalleeType,
1334
                                const CallArgList &Args) {
1335
  llvm::CallBase *CallOrInvoke;
1336
  llvm::Constant *CalleePtr = CGF.CGM.GetAddrOfFunction(CalleeDecl);
1337
  CGCallee Callee = CGCallee::forDirect(CalleePtr, GlobalDecl(CalleeDecl));
1338
  RValue RV =
1339
      CGF.EmitCall(CGF.CGM.getTypes().arrangeFreeFunctionCall(
1340
                       Args, CalleeType, /*ChainCall=*/false),
1341
                   Callee, ReturnValueSlot(), Args, &CallOrInvoke);
1342

1343
  /// C++1y [expr.new]p10:
1344
  ///   [In a new-expression,] an implementation is allowed to omit a call
1345
  ///   to a replaceable global allocation function.
1346
  ///
1347
  /// We model such elidable calls with the 'builtin' attribute.
1348
  llvm::Function *Fn = dyn_cast<llvm::Function>(CalleePtr);
1349
  if (CalleeDecl->isReplaceableGlobalAllocationFunction() &&
1350
      Fn && Fn->hasFnAttribute(llvm::Attribute::NoBuiltin)) {
1351
    CallOrInvoke->addFnAttr(llvm::Attribute::Builtin);
1352
  }
1353

1354
  return RV;
1355
}
1356

1357
RValue CodeGenFunction::EmitBuiltinNewDeleteCall(const FunctionProtoType *Type,
1358
                                                 const CallExpr *TheCall,
1359
                                                 bool IsDelete) {
1360
  CallArgList Args;
1361
  EmitCallArgs(Args, Type, TheCall->arguments());
1362
  // Find the allocation or deallocation function that we're calling.
1363
  ASTContext &Ctx = getContext();
1364
  DeclarationName Name = Ctx.DeclarationNames
1365
      .getCXXOperatorName(IsDelete ? OO_Delete : OO_New);
1366

1367
  for (auto *Decl : Ctx.getTranslationUnitDecl()->lookup(Name))
1368
    if (auto *FD = dyn_cast<FunctionDecl>(Decl))
1369
      if (Ctx.hasSameType(FD->getType(), QualType(Type, 0)))
1370
        return EmitNewDeleteCall(*this, FD, Type, Args);
1371
  llvm_unreachable("predeclared global operator new/delete is missing");
1372
}
1373

1374
namespace {
1375
/// The parameters to pass to a usual operator delete.
1376
struct UsualDeleteParams {
1377
  bool DestroyingDelete = false;
1378
  bool Size = false;
1379
  bool Alignment = false;
1380
};
1381
}
1382

1383
static UsualDeleteParams getUsualDeleteParams(const FunctionDecl *FD) {
1384
  UsualDeleteParams Params;
1385

1386
  const FunctionProtoType *FPT = FD->getType()->castAs<FunctionProtoType>();
1387
  auto AI = FPT->param_type_begin(), AE = FPT->param_type_end();
1388

1389
  // The first argument is always a void*.
1390
  ++AI;
1391

1392
  // The next parameter may be a std::destroying_delete_t.
1393
  if (FD->isDestroyingOperatorDelete()) {
1394
    Params.DestroyingDelete = true;
1395
    assert(AI != AE);
1396
    ++AI;
1397
  }
1398

1399
  // Figure out what other parameters we should be implicitly passing.
1400
  if (AI != AE && (*AI)->isIntegerType()) {
1401
    Params.Size = true;
1402
    ++AI;
1403
  }
1404

1405
  if (AI != AE && (*AI)->isAlignValT()) {
1406
    Params.Alignment = true;
1407
    ++AI;
1408
  }
1409

1410
  assert(AI == AE && "unexpected usual deallocation function parameter");
1411
  return Params;
1412
}
1413

1414
namespace {
1415
  /// A cleanup to call the given 'operator delete' function upon abnormal
1416
  /// exit from a new expression. Templated on a traits type that deals with
1417
  /// ensuring that the arguments dominate the cleanup if necessary.
1418
  template<typename Traits>
1419
  class CallDeleteDuringNew final : public EHScopeStack::Cleanup {
1420
    /// Type used to hold llvm::Value*s.
1421
    typedef typename Traits::ValueTy ValueTy;
1422
    /// Type used to hold RValues.
1423
    typedef typename Traits::RValueTy RValueTy;
1424
    struct PlacementArg {
1425
      RValueTy ArgValue;
1426
      QualType ArgType;
1427
    };
1428

1429
    unsigned NumPlacementArgs : 31;
1430
    LLVM_PREFERRED_TYPE(bool)
1431
    unsigned PassAlignmentToPlacementDelete : 1;
1432
    const FunctionDecl *OperatorDelete;
1433
    ValueTy Ptr;
1434
    ValueTy AllocSize;
1435
    CharUnits AllocAlign;
1436

1437
    PlacementArg *getPlacementArgs() {
1438
      return reinterpret_cast<PlacementArg *>(this + 1);
1439
    }
1440

1441
  public:
1442
    static size_t getExtraSize(size_t NumPlacementArgs) {
1443
      return NumPlacementArgs * sizeof(PlacementArg);
1444
    }
1445

1446
    CallDeleteDuringNew(size_t NumPlacementArgs,
1447
                        const FunctionDecl *OperatorDelete, ValueTy Ptr,
1448
                        ValueTy AllocSize, bool PassAlignmentToPlacementDelete,
1449
                        CharUnits AllocAlign)
1450
      : NumPlacementArgs(NumPlacementArgs),
1451
        PassAlignmentToPlacementDelete(PassAlignmentToPlacementDelete),
1452
        OperatorDelete(OperatorDelete), Ptr(Ptr), AllocSize(AllocSize),
1453
        AllocAlign(AllocAlign) {}
1454

1455
    void setPlacementArg(unsigned I, RValueTy Arg, QualType Type) {
1456
      assert(I < NumPlacementArgs && "index out of range");
1457
      getPlacementArgs()[I] = {Arg, Type};
1458
    }
1459

1460
    void Emit(CodeGenFunction &CGF, Flags flags) override {
1461
      const auto *FPT = OperatorDelete->getType()->castAs<FunctionProtoType>();
1462
      CallArgList DeleteArgs;
1463

1464
      // The first argument is always a void* (or C* for a destroying operator
1465
      // delete for class type C).
1466
      DeleteArgs.add(Traits::get(CGF, Ptr), FPT->getParamType(0));
1467

1468
      // Figure out what other parameters we should be implicitly passing.
1469
      UsualDeleteParams Params;
1470
      if (NumPlacementArgs) {
1471
        // A placement deallocation function is implicitly passed an alignment
1472
        // if the placement allocation function was, but is never passed a size.
1473
        Params.Alignment = PassAlignmentToPlacementDelete;
1474
      } else {
1475
        // For a non-placement new-expression, 'operator delete' can take a
1476
        // size and/or an alignment if it has the right parameters.
1477
        Params = getUsualDeleteParams(OperatorDelete);
1478
      }
1479

1480
      assert(!Params.DestroyingDelete &&
1481
             "should not call destroying delete in a new-expression");
1482

1483
      // The second argument can be a std::size_t (for non-placement delete).
1484
      if (Params.Size)
1485
        DeleteArgs.add(Traits::get(CGF, AllocSize),
1486
                       CGF.getContext().getSizeType());
1487

1488
      // The next (second or third) argument can be a std::align_val_t, which
1489
      // is an enum whose underlying type is std::size_t.
1490
      // FIXME: Use the right type as the parameter type. Note that in a call
1491
      // to operator delete(size_t, ...), we may not have it available.
1492
      if (Params.Alignment)
1493
        DeleteArgs.add(RValue::get(llvm::ConstantInt::get(
1494
                           CGF.SizeTy, AllocAlign.getQuantity())),
1495
                       CGF.getContext().getSizeType());
1496

1497
      // Pass the rest of the arguments, which must match exactly.
1498
      for (unsigned I = 0; I != NumPlacementArgs; ++I) {
1499
        auto Arg = getPlacementArgs()[I];
1500
        DeleteArgs.add(Traits::get(CGF, Arg.ArgValue), Arg.ArgType);
1501
      }
1502

1503
      // Call 'operator delete'.
1504
      EmitNewDeleteCall(CGF, OperatorDelete, FPT, DeleteArgs);
1505
    }
1506
  };
1507
}
1508

1509
/// Enter a cleanup to call 'operator delete' if the initializer in a
1510
/// new-expression throws.
1511
static void EnterNewDeleteCleanup(CodeGenFunction &CGF,
1512
                                  const CXXNewExpr *E,
1513
                                  Address NewPtr,
1514
                                  llvm::Value *AllocSize,
1515
                                  CharUnits AllocAlign,
1516
                                  const CallArgList &NewArgs) {
1517
  unsigned NumNonPlacementArgs = E->passAlignment() ? 2 : 1;
1518

1519
  // If we're not inside a conditional branch, then the cleanup will
1520
  // dominate and we can do the easier (and more efficient) thing.
1521
  if (!CGF.isInConditionalBranch()) {
1522
    struct DirectCleanupTraits {
1523
      typedef llvm::Value *ValueTy;
1524
      typedef RValue RValueTy;
1525
      static RValue get(CodeGenFunction &, ValueTy V) { return RValue::get(V); }
1526
      static RValue get(CodeGenFunction &, RValueTy V) { return V; }
1527
    };
1528

1529
    typedef CallDeleteDuringNew<DirectCleanupTraits> DirectCleanup;
1530

1531
    DirectCleanup *Cleanup = CGF.EHStack.pushCleanupWithExtra<DirectCleanup>(
1532
        EHCleanup, E->getNumPlacementArgs(), E->getOperatorDelete(),
1533
        NewPtr.emitRawPointer(CGF), AllocSize, E->passAlignment(), AllocAlign);
1534
    for (unsigned I = 0, N = E->getNumPlacementArgs(); I != N; ++I) {
1535
      auto &Arg = NewArgs[I + NumNonPlacementArgs];
1536
      Cleanup->setPlacementArg(I, Arg.getRValue(CGF), 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, RValue::get(NewPtr, CGF));
1545
  DominatingValue<RValue>::saved_type SavedAllocSize =
1546
    DominatingValue<RValue>::save(CGF, RValue::get(AllocSize));
1547

1548
  struct ConditionalCleanupTraits {
1549
    typedef DominatingValue<RValue>::saved_type ValueTy;
1550
    typedef DominatingValue<RValue>::saved_type RValueTy;
1551
    static RValue get(CodeGenFunction &CGF, ValueTy V) {
1552
      return V.restore(CGF);
1553
    }
1554
  };
1555
  typedef CallDeleteDuringNew<ConditionalCleanupTraits> ConditionalCleanup;
1556

1557
  ConditionalCleanup *Cleanup = CGF.EHStack
1558
    .pushCleanupWithExtra<ConditionalCleanup>(EHCleanup,
1559
                                              E->getNumPlacementArgs(),
1560
                                              E->getOperatorDelete(),
1561
                                              SavedNewPtr,
1562
                                              SavedAllocSize,
1563
                                              E->passAlignment(),
1564
                                              AllocAlign);
1565
  for (unsigned I = 0, N = E->getNumPlacementArgs(); I != N; ++I) {
1566
    auto &Arg = NewArgs[I + NumNonPlacementArgs];
1567
    Cleanup->setPlacementArg(
1568
        I, DominatingValue<RValue>::save(CGF, Arg.getRValue(CGF)), Arg.Ty);
1569
  }
1570

1571
  CGF.initFullExprCleanup();
1572
}
1573

1574
llvm::Value *CodeGenFunction::EmitCXXNewExpr(const CXXNewExpr *E) {
1575
  // The element type being allocated.
1576
  QualType allocType = getContext().getBaseElementType(E->getAllocatedType());
1577

1578
  // 1. Build a call to the allocation function.
1579
  FunctionDecl *allocator = E->getOperatorNew();
1580

1581
  // If there is a brace-initializer or C++20 parenthesized initializer, cannot
1582
  // allocate fewer elements than inits.
1583
  unsigned minElements = 0;
1584
  if (E->isArray() && E->hasInitializer()) {
1585
    const Expr *Init = E->getInitializer();
1586
    const InitListExpr *ILE = dyn_cast<InitListExpr>(Init);
1587
    const CXXParenListInitExpr *CPLIE = dyn_cast<CXXParenListInitExpr>(Init);
1588
    const Expr *IgnoreParen = Init->IgnoreParenImpCasts();
1589
    if ((ILE && ILE->isStringLiteralInit()) ||
1590
        isa<StringLiteral>(IgnoreParen) || isa<ObjCEncodeExpr>(IgnoreParen)) {
1591
      minElements =
1592
          cast<ConstantArrayType>(Init->getType()->getAsArrayTypeUnsafe())
1593
              ->getZExtSize();
1594
    } else if (ILE || CPLIE) {
1595
      minElements = ILE ? ILE->getNumInits() : CPLIE->getInitExprs().size();
1596
    }
1597
  }
1598

1599
  llvm::Value *numElements = nullptr;
1600
  llvm::Value *allocSizeWithoutCookie = nullptr;
1601
  llvm::Value *allocSize =
1602
    EmitCXXNewAllocSize(*this, E, minElements, numElements,
1603
                        allocSizeWithoutCookie);
1604
  CharUnits allocAlign = getContext().getTypeAlignInChars(allocType);
1605

1606
  // Emit the allocation call.  If the allocator is a global placement
1607
  // operator, just "inline" it directly.
1608
  Address allocation = Address::invalid();
1609
  CallArgList allocatorArgs;
1610
  if (allocator->isReservedGlobalPlacementOperator()) {
1611
    assert(E->getNumPlacementArgs() == 1);
1612
    const Expr *arg = *E->placement_arguments().begin();
1613

1614
    LValueBaseInfo BaseInfo;
1615
    allocation = EmitPointerWithAlignment(arg, &BaseInfo);
1616

1617
    // The pointer expression will, in many cases, be an opaque void*.
1618
    // In these cases, discard the computed alignment and use the
1619
    // formal alignment of the allocated type.
1620
    if (BaseInfo.getAlignmentSource() != AlignmentSource::Decl)
1621
      allocation.setAlignment(allocAlign);
1622

1623
    // Set up allocatorArgs for the call to operator delete if it's not
1624
    // the reserved global operator.
1625
    if (E->getOperatorDelete() &&
1626
        !E->getOperatorDelete()->isReservedGlobalPlacementOperator()) {
1627
      allocatorArgs.add(RValue::get(allocSize), getContext().getSizeType());
1628
      allocatorArgs.add(RValue::get(allocation, *this), arg->getType());
1629
    }
1630

1631
  } else {
1632
    const FunctionProtoType *allocatorType =
1633
      allocator->getType()->castAs<FunctionProtoType>();
1634
    unsigned ParamsToSkip = 0;
1635

1636
    // The allocation size is the first argument.
1637
    QualType sizeType = getContext().getSizeType();
1638
    allocatorArgs.add(RValue::get(allocSize), sizeType);
1639
    ++ParamsToSkip;
1640

1641
    if (allocSize != allocSizeWithoutCookie) {
1642
      CharUnits cookieAlign = getSizeAlign(); // FIXME: Ask the ABI.
1643
      allocAlign = std::max(allocAlign, cookieAlign);
1644
    }
1645

1646
    // The allocation alignment may be passed as the second argument.
1647
    if (E->passAlignment()) {
1648
      QualType AlignValT = sizeType;
1649
      if (allocatorType->getNumParams() > 1) {
1650
        AlignValT = allocatorType->getParamType(1);
1651
        assert(getContext().hasSameUnqualifiedType(
1652
                   AlignValT->castAs<EnumType>()->getDecl()->getIntegerType(),
1653
                   sizeType) &&
1654
               "wrong type for alignment parameter");
1655
        ++ParamsToSkip;
1656
      } else {
1657
        // Corner case, passing alignment to 'operator new(size_t, ...)'.
1658
        assert(allocator->isVariadic() && "can't pass alignment to allocator");
1659
      }
1660
      allocatorArgs.add(
1661
          RValue::get(llvm::ConstantInt::get(SizeTy, allocAlign.getQuantity())),
1662
          AlignValT);
1663
    }
1664

1665
    // FIXME: Why do we not pass a CalleeDecl here?
1666
    EmitCallArgs(allocatorArgs, allocatorType, E->placement_arguments(),
1667
                 /*AC*/AbstractCallee(), /*ParamsToSkip*/ParamsToSkip);
1668

1669
    RValue RV =
1670
      EmitNewDeleteCall(*this, allocator, allocatorType, allocatorArgs);
1671

1672
    // Set !heapallocsite metadata on the call to operator new.
1673
    if (getDebugInfo())
1674
      if (auto *newCall = dyn_cast<llvm::CallBase>(RV.getScalarVal()))
1675
        getDebugInfo()->addHeapAllocSiteMetadata(newCall, allocType,
1676
                                                 E->getExprLoc());
1677

1678
    // If this was a call to a global replaceable allocation function that does
1679
    // not take an alignment argument, the allocator is known to produce
1680
    // storage that's suitably aligned for any object that fits, up to a known
1681
    // threshold. Otherwise assume it's suitably aligned for the allocated type.
1682
    CharUnits allocationAlign = allocAlign;
1683
    if (!E->passAlignment() &&
1684
        allocator->isReplaceableGlobalAllocationFunction()) {
1685
      unsigned AllocatorAlign = llvm::bit_floor(std::min<uint64_t>(
1686
          Target.getNewAlign(), getContext().getTypeSize(allocType)));
1687
      allocationAlign = std::max(
1688
          allocationAlign, getContext().toCharUnitsFromBits(AllocatorAlign));
1689
    }
1690

1691
    allocation = Address(RV.getScalarVal(), Int8Ty, allocationAlign);
1692
  }
1693

1694
  // Emit a null check on the allocation result if the allocation
1695
  // function is allowed to return null (because it has a non-throwing
1696
  // exception spec or is the reserved placement new) and we have an
1697
  // interesting initializer will be running sanitizers on the initialization.
1698
  bool nullCheck = E->shouldNullCheckAllocation() &&
1699
                   (!allocType.isPODType(getContext()) || E->hasInitializer() ||
1700
                    sanitizePerformTypeCheck());
1701

1702
  llvm::BasicBlock *nullCheckBB = nullptr;
1703
  llvm::BasicBlock *contBB = nullptr;
1704

1705
  // The null-check means that the initializer is conditionally
1706
  // evaluated.
1707
  ConditionalEvaluation conditional(*this);
1708

1709
  if (nullCheck) {
1710
    conditional.begin(*this);
1711

1712
    nullCheckBB = Builder.GetInsertBlock();
1713
    llvm::BasicBlock *notNullBB = createBasicBlock("new.notnull");
1714
    contBB = createBasicBlock("new.cont");
1715

1716
    llvm::Value *isNull = Builder.CreateIsNull(allocation, "new.isnull");
1717
    Builder.CreateCondBr(isNull, contBB, notNullBB);
1718
    EmitBlock(notNullBB);
1719
  }
1720

1721
  // If there's an operator delete, enter a cleanup to call it if an
1722
  // exception is thrown.
1723
  EHScopeStack::stable_iterator operatorDeleteCleanup;
1724
  llvm::Instruction *cleanupDominator = nullptr;
1725
  if (E->getOperatorDelete() &&
1726
      !E->getOperatorDelete()->isReservedGlobalPlacementOperator()) {
1727
    EnterNewDeleteCleanup(*this, E, allocation, allocSize, allocAlign,
1728
                          allocatorArgs);
1729
    operatorDeleteCleanup = EHStack.stable_begin();
1730
    cleanupDominator = Builder.CreateUnreachable();
1731
  }
1732

1733
  assert((allocSize == allocSizeWithoutCookie) ==
1734
         CalculateCookiePadding(*this, E).isZero());
1735
  if (allocSize != allocSizeWithoutCookie) {
1736
    assert(E->isArray());
1737
    allocation = CGM.getCXXABI().InitializeArrayCookie(*this, allocation,
1738
                                                       numElements,
1739
                                                       E, allocType);
1740
  }
1741

1742
  llvm::Type *elementTy = ConvertTypeForMem(allocType);
1743
  Address result = allocation.withElementType(elementTy);
1744

1745
  // Passing pointer through launder.invariant.group to avoid propagation of
1746
  // vptrs information which may be included in previous type.
1747
  // To not break LTO with different optimizations levels, we do it regardless
1748
  // of optimization level.
1749
  if (CGM.getCodeGenOpts().StrictVTablePointers &&
1750
      allocator->isReservedGlobalPlacementOperator())
1751
    result = Builder.CreateLaunderInvariantGroup(result);
1752

1753
  // Emit sanitizer checks for pointer value now, so that in the case of an
1754
  // array it was checked only once and not at each constructor call. We may
1755
  // have already checked that the pointer is non-null.
1756
  // FIXME: If we have an array cookie and a potentially-throwing allocator,
1757
  // we'll null check the wrong pointer here.
1758
  SanitizerSet SkippedChecks;
1759
  SkippedChecks.set(SanitizerKind::Null, nullCheck);
1760
  EmitTypeCheck(CodeGenFunction::TCK_ConstructorCall,
1761
                E->getAllocatedTypeSourceInfo()->getTypeLoc().getBeginLoc(),
1762
                result, allocType, result.getAlignment(), SkippedChecks,
1763
                numElements);
1764

1765
  EmitNewInitializer(*this, E, allocType, elementTy, result, numElements,
1766
                     allocSizeWithoutCookie);
1767
  llvm::Value *resultPtr = result.emitRawPointer(*this);
1768
  if (E->isArray()) {
1769
    // NewPtr is a pointer to the base element type.  If we're
1770
    // allocating an array of arrays, we'll need to cast back to the
1771
    // array pointer type.
1772
    llvm::Type *resultType = ConvertTypeForMem(E->getType());
1773
    if (resultPtr->getType() != resultType)
1774
      resultPtr = Builder.CreateBitCast(resultPtr, resultType);
1775
  }
1776

1777
  // Deactivate the 'operator delete' cleanup if we finished
1778
  // initialization.
1779
  if (operatorDeleteCleanup.isValid()) {
1780
    DeactivateCleanupBlock(operatorDeleteCleanup, cleanupDominator);
1781
    cleanupDominator->eraseFromParent();
1782
  }
1783

1784
  if (nullCheck) {
1785
    conditional.end(*this);
1786

1787
    llvm::BasicBlock *notNullBB = Builder.GetInsertBlock();
1788
    EmitBlock(contBB);
1789

1790
    llvm::PHINode *PHI = Builder.CreatePHI(resultPtr->getType(), 2);
1791
    PHI->addIncoming(resultPtr, notNullBB);
1792
    PHI->addIncoming(llvm::Constant::getNullValue(resultPtr->getType()),
1793
                     nullCheckBB);
1794

1795
    resultPtr = PHI;
1796
  }
1797

1798
  return resultPtr;
1799
}
1800

1801
void CodeGenFunction::EmitDeleteCall(const FunctionDecl *DeleteFD,
1802
                                     llvm::Value *Ptr, QualType DeleteTy,
1803
                                     llvm::Value *NumElements,
1804
                                     CharUnits CookieSize) {
1805
  assert((!NumElements && CookieSize.isZero()) ||
1806
         DeleteFD->getOverloadedOperator() == OO_Array_Delete);
1807

1808
  const auto *DeleteFTy = DeleteFD->getType()->castAs<FunctionProtoType>();
1809
  CallArgList DeleteArgs;
1810

1811
  auto Params = getUsualDeleteParams(DeleteFD);
1812
  auto ParamTypeIt = DeleteFTy->param_type_begin();
1813

1814
  // Pass the pointer itself.
1815
  QualType ArgTy = *ParamTypeIt++;
1816
  llvm::Value *DeletePtr = Builder.CreateBitCast(Ptr, ConvertType(ArgTy));
1817
  DeleteArgs.add(RValue::get(DeletePtr), ArgTy);
1818

1819
  // Pass the std::destroying_delete tag if present.
1820
  llvm::AllocaInst *DestroyingDeleteTag = nullptr;
1821
  if (Params.DestroyingDelete) {
1822
    QualType DDTag = *ParamTypeIt++;
1823
    llvm::Type *Ty = getTypes().ConvertType(DDTag);
1824
    CharUnits Align = CGM.getNaturalTypeAlignment(DDTag);
1825
    DestroyingDeleteTag = CreateTempAlloca(Ty, "destroying.delete.tag");
1826
    DestroyingDeleteTag->setAlignment(Align.getAsAlign());
1827
    DeleteArgs.add(
1828
        RValue::getAggregate(Address(DestroyingDeleteTag, Ty, Align)), DDTag);
1829
  }
1830

1831
  // Pass the size if the delete function has a size_t parameter.
1832
  if (Params.Size) {
1833
    QualType SizeType = *ParamTypeIt++;
1834
    CharUnits DeleteTypeSize = getContext().getTypeSizeInChars(DeleteTy);
1835
    llvm::Value *Size = llvm::ConstantInt::get(ConvertType(SizeType),
1836
                                               DeleteTypeSize.getQuantity());
1837

1838
    // For array new, multiply by the number of elements.
1839
    if (NumElements)
1840
      Size = Builder.CreateMul(Size, NumElements);
1841

1842
    // If there is a cookie, add the cookie size.
1843
    if (!CookieSize.isZero())
1844
      Size = Builder.CreateAdd(
1845
          Size, llvm::ConstantInt::get(SizeTy, CookieSize.getQuantity()));
1846

1847
    DeleteArgs.add(RValue::get(Size), SizeType);
1848
  }
1849

1850
  // Pass the alignment if the delete function has an align_val_t parameter.
1851
  if (Params.Alignment) {
1852
    QualType AlignValType = *ParamTypeIt++;
1853
    CharUnits DeleteTypeAlign =
1854
        getContext().toCharUnitsFromBits(getContext().getTypeAlignIfKnown(
1855
            DeleteTy, true /* NeedsPreferredAlignment */));
1856
    llvm::Value *Align = llvm::ConstantInt::get(ConvertType(AlignValType),
1857
                                                DeleteTypeAlign.getQuantity());
1858
    DeleteArgs.add(RValue::get(Align), AlignValType);
1859
  }
1860

1861
  assert(ParamTypeIt == DeleteFTy->param_type_end() &&
1862
         "unknown parameter to usual delete function");
1863

1864
  // Emit the call to delete.
1865
  EmitNewDeleteCall(*this, DeleteFD, DeleteFTy, DeleteArgs);
1866

1867
  // If call argument lowering didn't use the destroying_delete_t alloca,
1868
  // remove it again.
1869
  if (DestroyingDeleteTag && DestroyingDeleteTag->use_empty())
1870
    DestroyingDeleteTag->eraseFromParent();
1871
}
1872

1873
namespace {
1874
  /// Calls the given 'operator delete' on a single object.
1875
  struct CallObjectDelete final : EHScopeStack::Cleanup {
1876
    llvm::Value *Ptr;
1877
    const FunctionDecl *OperatorDelete;
1878
    QualType ElementType;
1879

1880
    CallObjectDelete(llvm::Value *Ptr,
1881
                     const FunctionDecl *OperatorDelete,
1882
                     QualType ElementType)
1883
      : Ptr(Ptr), OperatorDelete(OperatorDelete), ElementType(ElementType) {}
1884

1885
    void Emit(CodeGenFunction &CGF, Flags flags) override {
1886
      CGF.EmitDeleteCall(OperatorDelete, Ptr, ElementType);
1887
    }
1888
  };
1889
}
1890

1891
void
1892
CodeGenFunction::pushCallObjectDeleteCleanup(const FunctionDecl *OperatorDelete,
1893
                                             llvm::Value *CompletePtr,
1894
                                             QualType ElementType) {
1895
  EHStack.pushCleanup<CallObjectDelete>(NormalAndEHCleanup, CompletePtr,
1896
                                        OperatorDelete, ElementType);
1897
}
1898

1899
/// Emit the code for deleting a single object with a destroying operator
1900
/// delete. If the element type has a non-virtual destructor, Ptr has already
1901
/// been converted to the type of the parameter of 'operator delete'. Otherwise
1902
/// Ptr points to an object of the static type.
1903
static void EmitDestroyingObjectDelete(CodeGenFunction &CGF,
1904
                                       const CXXDeleteExpr *DE, Address Ptr,
1905
                                       QualType ElementType) {
1906
  auto *Dtor = ElementType->getAsCXXRecordDecl()->getDestructor();
1907
  if (Dtor && Dtor->isVirtual())
1908
    CGF.CGM.getCXXABI().emitVirtualObjectDelete(CGF, DE, Ptr, ElementType,
1909
                                                Dtor);
1910
  else
1911
    CGF.EmitDeleteCall(DE->getOperatorDelete(), Ptr.emitRawPointer(CGF),
1912
                       ElementType);
1913
}
1914

1915
/// Emit the code for deleting a single object.
1916
/// \return \c true if we started emitting UnconditionalDeleteBlock, \c false
1917
/// if not.
1918
static bool EmitObjectDelete(CodeGenFunction &CGF,
1919
                             const CXXDeleteExpr *DE,
1920
                             Address Ptr,
1921
                             QualType ElementType,
1922
                             llvm::BasicBlock *UnconditionalDeleteBlock) {
1923
  // C++11 [expr.delete]p3:
1924
  //   If the static type of the object to be deleted is different from its
1925
  //   dynamic type, the static type shall be a base class of the dynamic type
1926
  //   of the object to be deleted and the static type shall have a virtual
1927
  //   destructor or the behavior is undefined.
1928
  CGF.EmitTypeCheck(CodeGenFunction::TCK_MemberCall, DE->getExprLoc(), Ptr,
1929
                    ElementType);
1930

1931
  const FunctionDecl *OperatorDelete = DE->getOperatorDelete();
1932
  assert(!OperatorDelete->isDestroyingOperatorDelete());
1933

1934
  // Find the destructor for the type, if applicable.  If the
1935
  // destructor is virtual, we'll just emit the vcall and return.
1936
  const CXXDestructorDecl *Dtor = nullptr;
1937
  if (const RecordType *RT = ElementType->getAs<RecordType>()) {
1938
    CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
1939
    if (RD->hasDefinition() && !RD->hasTrivialDestructor()) {
1940
      Dtor = RD->getDestructor();
1941

1942
      if (Dtor->isVirtual()) {
1943
        bool UseVirtualCall = true;
1944
        const Expr *Base = DE->getArgument();
1945
        if (auto *DevirtualizedDtor =
1946
                dyn_cast_or_null<const CXXDestructorDecl>(
1947
                    Dtor->getDevirtualizedMethod(
1948
                        Base, CGF.CGM.getLangOpts().AppleKext))) {
1949
          UseVirtualCall = false;
1950
          const CXXRecordDecl *DevirtualizedClass =
1951
              DevirtualizedDtor->getParent();
1952
          if (declaresSameEntity(getCXXRecord(Base), DevirtualizedClass)) {
1953
            // Devirtualized to the class of the base type (the type of the
1954
            // whole expression).
1955
            Dtor = DevirtualizedDtor;
1956
          } else {
1957
            // Devirtualized to some other type. Would need to cast the this
1958
            // pointer to that type but we don't have support for that yet, so
1959
            // do a virtual call. FIXME: handle the case where it is
1960
            // devirtualized to the derived type (the type of the inner
1961
            // expression) as in EmitCXXMemberOrOperatorMemberCallExpr.
1962
            UseVirtualCall = true;
1963
          }
1964
        }
1965
        if (UseVirtualCall) {
1966
          CGF.CGM.getCXXABI().emitVirtualObjectDelete(CGF, DE, Ptr, ElementType,
1967
                                                      Dtor);
1968
          return false;
1969
        }
1970
      }
1971
    }
1972
  }
1973

1974
  // Make sure that we call delete even if the dtor throws.
1975
  // This doesn't have to a conditional cleanup because we're going
1976
  // to pop it off in a second.
1977
  CGF.EHStack.pushCleanup<CallObjectDelete>(
1978
      NormalAndEHCleanup, Ptr.emitRawPointer(CGF), OperatorDelete, ElementType);
1979

1980
  if (Dtor)
1981
    CGF.EmitCXXDestructorCall(Dtor, Dtor_Complete,
1982
                              /*ForVirtualBase=*/false,
1983
                              /*Delegating=*/false,
1984
                              Ptr, ElementType);
1985
  else if (auto Lifetime = ElementType.getObjCLifetime()) {
1986
    switch (Lifetime) {
1987
    case Qualifiers::OCL_None:
1988
    case Qualifiers::OCL_ExplicitNone:
1989
    case Qualifiers::OCL_Autoreleasing:
1990
      break;
1991

1992
    case Qualifiers::OCL_Strong:
1993
      CGF.EmitARCDestroyStrong(Ptr, ARCPreciseLifetime);
1994
      break;
1995

1996
    case Qualifiers::OCL_Weak:
1997
      CGF.EmitARCDestroyWeak(Ptr);
1998
      break;
1999
    }
2000
  }
2001

2002
  // When optimizing for size, call 'operator delete' unconditionally.
2003
  if (CGF.CGM.getCodeGenOpts().OptimizeSize > 1) {
2004
    CGF.EmitBlock(UnconditionalDeleteBlock);
2005
    CGF.PopCleanupBlock();
2006
    return true;
2007
  }
2008

2009
  CGF.PopCleanupBlock();
2010
  return false;
2011
}
2012

2013
namespace {
2014
  /// Calls the given 'operator delete' on an array of objects.
2015
  struct CallArrayDelete final : EHScopeStack::Cleanup {
2016
    llvm::Value *Ptr;
2017
    const FunctionDecl *OperatorDelete;
2018
    llvm::Value *NumElements;
2019
    QualType ElementType;
2020
    CharUnits CookieSize;
2021

2022
    CallArrayDelete(llvm::Value *Ptr,
2023
                    const FunctionDecl *OperatorDelete,
2024
                    llvm::Value *NumElements,
2025
                    QualType ElementType,
2026
                    CharUnits CookieSize)
2027
      : Ptr(Ptr), OperatorDelete(OperatorDelete), NumElements(NumElements),
2028
        ElementType(ElementType), CookieSize(CookieSize) {}
2029

2030
    void Emit(CodeGenFunction &CGF, Flags flags) override {
2031
      CGF.EmitDeleteCall(OperatorDelete, Ptr, ElementType, NumElements,
2032
                         CookieSize);
2033
    }
2034
  };
2035
}
2036

2037
/// Emit the code for deleting an array of objects.
2038
static void EmitArrayDelete(CodeGenFunction &CGF,
2039
                            const CXXDeleteExpr *E,
2040
                            Address deletedPtr,
2041
                            QualType elementType) {
2042
  llvm::Value *numElements = nullptr;
2043
  llvm::Value *allocatedPtr = nullptr;
2044
  CharUnits cookieSize;
2045
  CGF.CGM.getCXXABI().ReadArrayCookie(CGF, deletedPtr, E, elementType,
2046
                                      numElements, allocatedPtr, cookieSize);
2047

2048
  assert(allocatedPtr && "ReadArrayCookie didn't set allocated pointer");
2049

2050
  // Make sure that we call delete even if one of the dtors throws.
2051
  const FunctionDecl *operatorDelete = E->getOperatorDelete();
2052
  CGF.EHStack.pushCleanup<CallArrayDelete>(NormalAndEHCleanup,
2053
                                           allocatedPtr, operatorDelete,
2054
                                           numElements, elementType,
2055
                                           cookieSize);
2056

2057
  // Destroy the elements.
2058
  if (QualType::DestructionKind dtorKind = elementType.isDestructedType()) {
2059
    assert(numElements && "no element count for a type with a destructor!");
2060

2061
    CharUnits elementSize = CGF.getContext().getTypeSizeInChars(elementType);
2062
    CharUnits elementAlign =
2063
      deletedPtr.getAlignment().alignmentOfArrayElement(elementSize);
2064

2065
    llvm::Value *arrayBegin = deletedPtr.emitRawPointer(CGF);
2066
    llvm::Value *arrayEnd = CGF.Builder.CreateInBoundsGEP(
2067
      deletedPtr.getElementType(), arrayBegin, numElements, "delete.end");
2068

2069
    // Note that it is legal to allocate a zero-length array, and we
2070
    // can never fold the check away because the length should always
2071
    // come from a cookie.
2072
    CGF.emitArrayDestroy(arrayBegin, arrayEnd, elementType, elementAlign,
2073
                         CGF.getDestroyer(dtorKind),
2074
                         /*checkZeroLength*/ true,
2075
                         CGF.needsEHCleanup(dtorKind));
2076
  }
2077

2078
  // Pop the cleanup block.
2079
  CGF.PopCleanupBlock();
2080
}
2081

2082
void CodeGenFunction::EmitCXXDeleteExpr(const CXXDeleteExpr *E) {
2083
  const Expr *Arg = E->getArgument();
2084
  Address Ptr = EmitPointerWithAlignment(Arg);
2085

2086
  // Null check the pointer.
2087
  //
2088
  // We could avoid this null check if we can determine that the object
2089
  // destruction is trivial and doesn't require an array cookie; we can
2090
  // unconditionally perform the operator delete call in that case. For now, we
2091
  // assume that deleted pointers are null rarely enough that it's better to
2092
  // keep the branch. This might be worth revisiting for a -O0 code size win.
2093
  llvm::BasicBlock *DeleteNotNull = createBasicBlock("delete.notnull");
2094
  llvm::BasicBlock *DeleteEnd = createBasicBlock("delete.end");
2095

2096
  llvm::Value *IsNull = Builder.CreateIsNull(Ptr, "isnull");
2097

2098
  Builder.CreateCondBr(IsNull, DeleteEnd, DeleteNotNull);
2099
  EmitBlock(DeleteNotNull);
2100
  Ptr.setKnownNonNull();
2101

2102
  QualType DeleteTy = E->getDestroyedType();
2103

2104
  // A destroying operator delete overrides the entire operation of the
2105
  // delete expression.
2106
  if (E->getOperatorDelete()->isDestroyingOperatorDelete()) {
2107
    EmitDestroyingObjectDelete(*this, E, Ptr, DeleteTy);
2108
    EmitBlock(DeleteEnd);
2109
    return;
2110
  }
2111

2112
  // We might be deleting a pointer to array.  If so, GEP down to the
2113
  // first non-array element.
2114
  // (this assumes that A(*)[3][7] is converted to [3 x [7 x %A]]*)
2115
  if (DeleteTy->isConstantArrayType()) {
2116
    llvm::Value *Zero = Builder.getInt32(0);
2117
    SmallVector<llvm::Value*,8> GEP;
2118

2119
    GEP.push_back(Zero); // point at the outermost array
2120

2121
    // For each layer of array type we're pointing at:
2122
    while (const ConstantArrayType *Arr
2123
             = getContext().getAsConstantArrayType(DeleteTy)) {
2124
      // 1. Unpeel the array type.
2125
      DeleteTy = Arr->getElementType();
2126

2127
      // 2. GEP to the first element of the array.
2128
      GEP.push_back(Zero);
2129
    }
2130

2131
    Ptr = Builder.CreateInBoundsGEP(Ptr, GEP, ConvertTypeForMem(DeleteTy),
2132
                                    Ptr.getAlignment(), "del.first");
2133
  }
2134

2135
  assert(ConvertTypeForMem(DeleteTy) == Ptr.getElementType());
2136

2137
  if (E->isArrayForm()) {
2138
    EmitArrayDelete(*this, E, Ptr, DeleteTy);
2139
    EmitBlock(DeleteEnd);
2140
  } else {
2141
    if (!EmitObjectDelete(*this, E, Ptr, DeleteTy, DeleteEnd))
2142
      EmitBlock(DeleteEnd);
2143
  }
2144
}
2145

2146
static llvm::Value *EmitTypeidFromVTable(CodeGenFunction &CGF, const Expr *E,
2147
                                         llvm::Type *StdTypeInfoPtrTy,
2148
                                         bool HasNullCheck) {
2149
  // Get the vtable pointer.
2150
  Address ThisPtr = CGF.EmitLValue(E).getAddress();
2151

2152
  QualType SrcRecordTy = E->getType();
2153

2154
  // C++ [class.cdtor]p4:
2155
  //   If the operand of typeid refers to the object under construction or
2156
  //   destruction and the static type of the operand is neither the constructor
2157
  //   or destructor’s class nor one of its bases, the behavior is undefined.
2158
  CGF.EmitTypeCheck(CodeGenFunction::TCK_DynamicOperation, E->getExprLoc(),
2159
                    ThisPtr, SrcRecordTy);
2160

2161
  // Whether we need an explicit null pointer check. For example, with the
2162
  // Microsoft ABI, if this is a call to __RTtypeid, the null pointer check and
2163
  // exception throw is inside the __RTtypeid(nullptr) call
2164
  if (HasNullCheck &&
2165
      CGF.CGM.getCXXABI().shouldTypeidBeNullChecked(SrcRecordTy)) {
2166
    llvm::BasicBlock *BadTypeidBlock =
2167
        CGF.createBasicBlock("typeid.bad_typeid");
2168
    llvm::BasicBlock *EndBlock = CGF.createBasicBlock("typeid.end");
2169

2170
    llvm::Value *IsNull = CGF.Builder.CreateIsNull(ThisPtr);
2171
    CGF.Builder.CreateCondBr(IsNull, BadTypeidBlock, EndBlock);
2172

2173
    CGF.EmitBlock(BadTypeidBlock);
2174
    CGF.CGM.getCXXABI().EmitBadTypeidCall(CGF);
2175
    CGF.EmitBlock(EndBlock);
2176
  }
2177

2178
  return CGF.CGM.getCXXABI().EmitTypeid(CGF, SrcRecordTy, ThisPtr,
2179
                                        StdTypeInfoPtrTy);
2180
}
2181

2182
llvm::Value *CodeGenFunction::EmitCXXTypeidExpr(const CXXTypeidExpr *E) {
2183
  // Ideally, we would like to use GlobalsInt8PtrTy here, however, we cannot,
2184
  // primarily because the result of applying typeid is a value of type
2185
  // type_info, which is declared & defined by the standard library
2186
  // implementation and expects to operate on the generic (default) AS.
2187
  // https://reviews.llvm.org/D157452 has more context, and a possible solution.
2188
  llvm::Type *PtrTy = Int8PtrTy;
2189
  LangAS GlobAS = CGM.GetGlobalVarAddressSpace(nullptr);
2190

2191
  auto MaybeASCast = [=](auto &&TypeInfo) {
2192
    if (GlobAS == LangAS::Default)
2193
      return TypeInfo;
2194
    return getTargetHooks().performAddrSpaceCast(CGM,TypeInfo, GlobAS,
2195
                                                 LangAS::Default, PtrTy);
2196
  };
2197

2198
  if (E->isTypeOperand()) {
2199
    llvm::Constant *TypeInfo =
2200
        CGM.GetAddrOfRTTIDescriptor(E->getTypeOperand(getContext()));
2201
    return MaybeASCast(TypeInfo);
2202
  }
2203

2204
  // C++ [expr.typeid]p2:
2205
  //   When typeid is applied to a glvalue expression whose type is a
2206
  //   polymorphic class type, the result refers to a std::type_info object
2207
  //   representing the type of the most derived object (that is, the dynamic
2208
  //   type) to which the glvalue refers.
2209
  // If the operand is already most derived object, no need to look up vtable.
2210
  if (E->isPotentiallyEvaluated() && !E->isMostDerived(getContext()))
2211
    return EmitTypeidFromVTable(*this, E->getExprOperand(), PtrTy,
2212
                                E->hasNullCheck());
2213

2214
  QualType OperandTy = E->getExprOperand()->getType();
2215
  return MaybeASCast(CGM.GetAddrOfRTTIDescriptor(OperandTy));
2216
}
2217

2218
static llvm::Value *EmitDynamicCastToNull(CodeGenFunction &CGF,
2219
                                          QualType DestTy) {
2220
  llvm::Type *DestLTy = CGF.ConvertType(DestTy);
2221
  if (DestTy->isPointerType())
2222
    return llvm::Constant::getNullValue(DestLTy);
2223

2224
  /// C++ [expr.dynamic.cast]p9:
2225
  ///   A failed cast to reference type throws std::bad_cast
2226
  if (!CGF.CGM.getCXXABI().EmitBadCastCall(CGF))
2227
    return nullptr;
2228

2229
  CGF.Builder.ClearInsertionPoint();
2230
  return llvm::PoisonValue::get(DestLTy);
2231
}
2232

2233
llvm::Value *CodeGenFunction::EmitDynamicCast(Address ThisAddr,
2234
                                              const CXXDynamicCastExpr *DCE) {
2235
  CGM.EmitExplicitCastExprType(DCE, this);
2236
  QualType DestTy = DCE->getTypeAsWritten();
2237

2238
  QualType SrcTy = DCE->getSubExpr()->getType();
2239

2240
  // C++ [expr.dynamic.cast]p7:
2241
  //   If T is "pointer to cv void," then the result is a pointer to the most
2242
  //   derived object pointed to by v.
2243
  bool IsDynamicCastToVoid = DestTy->isVoidPointerType();
2244
  QualType SrcRecordTy;
2245
  QualType DestRecordTy;
2246
  if (IsDynamicCastToVoid) {
2247
    SrcRecordTy = SrcTy->getPointeeType();
2248
    // No DestRecordTy.
2249
  } else if (const PointerType *DestPTy = DestTy->getAs<PointerType>()) {
2250
    SrcRecordTy = SrcTy->castAs<PointerType>()->getPointeeType();
2251
    DestRecordTy = DestPTy->getPointeeType();
2252
  } else {
2253
    SrcRecordTy = SrcTy;
2254
    DestRecordTy = DestTy->castAs<ReferenceType>()->getPointeeType();
2255
  }
2256

2257
  // C++ [class.cdtor]p5:
2258
  //   If the operand of the dynamic_cast refers to the object under
2259
  //   construction or destruction and the static type of the operand is not a
2260
  //   pointer to or object of the constructor or destructor’s own class or one
2261
  //   of its bases, the dynamic_cast results in undefined behavior.
2262
  EmitTypeCheck(TCK_DynamicOperation, DCE->getExprLoc(), ThisAddr, SrcRecordTy);
2263

2264
  if (DCE->isAlwaysNull()) {
2265
    if (llvm::Value *T = EmitDynamicCastToNull(*this, DestTy)) {
2266
      // Expression emission is expected to retain a valid insertion point.
2267
      if (!Builder.GetInsertBlock())
2268
        EmitBlock(createBasicBlock("dynamic_cast.unreachable"));
2269
      return T;
2270
    }
2271
  }
2272

2273
  assert(SrcRecordTy->isRecordType() && "source type must be a record type!");
2274

2275
  // If the destination is effectively final, the cast succeeds if and only
2276
  // if the dynamic type of the pointer is exactly the destination type.
2277
  bool IsExact = !IsDynamicCastToVoid &&
2278
                 CGM.getCodeGenOpts().OptimizationLevel > 0 &&
2279
                 DestRecordTy->getAsCXXRecordDecl()->isEffectivelyFinal() &&
2280
                 CGM.getCXXABI().shouldEmitExactDynamicCast(DestRecordTy);
2281

2282
  // C++ [expr.dynamic.cast]p4:
2283
  //   If the value of v is a null pointer value in the pointer case, the result
2284
  //   is the null pointer value of type T.
2285
  bool ShouldNullCheckSrcValue =
2286
      IsExact || CGM.getCXXABI().shouldDynamicCastCallBeNullChecked(
2287
                     SrcTy->isPointerType(), SrcRecordTy);
2288

2289
  llvm::BasicBlock *CastNull = nullptr;
2290
  llvm::BasicBlock *CastNotNull = nullptr;
2291
  llvm::BasicBlock *CastEnd = createBasicBlock("dynamic_cast.end");
2292

2293
  if (ShouldNullCheckSrcValue) {
2294
    CastNull = createBasicBlock("dynamic_cast.null");
2295
    CastNotNull = createBasicBlock("dynamic_cast.notnull");
2296

2297
    llvm::Value *IsNull = Builder.CreateIsNull(ThisAddr);
2298
    Builder.CreateCondBr(IsNull, CastNull, CastNotNull);
2299
    EmitBlock(CastNotNull);
2300
  }
2301

2302
  llvm::Value *Value;
2303
  if (IsDynamicCastToVoid) {
2304
    Value = CGM.getCXXABI().emitDynamicCastToVoid(*this, ThisAddr, SrcRecordTy);
2305
  } else if (IsExact) {
2306
    // If the destination type is effectively final, this pointer points to the
2307
    // right type if and only if its vptr has the right value.
2308
    Value = CGM.getCXXABI().emitExactDynamicCast(
2309
        *this, ThisAddr, SrcRecordTy, DestTy, DestRecordTy, CastEnd, CastNull);
2310
  } else {
2311
    assert(DestRecordTy->isRecordType() &&
2312
           "destination type must be a record type!");
2313
    Value = CGM.getCXXABI().emitDynamicCastCall(*this, ThisAddr, SrcRecordTy,
2314
                                                DestTy, DestRecordTy, CastEnd);
2315
  }
2316
  CastNotNull = Builder.GetInsertBlock();
2317

2318
  llvm::Value *NullValue = nullptr;
2319
  if (ShouldNullCheckSrcValue) {
2320
    EmitBranch(CastEnd);
2321

2322
    EmitBlock(CastNull);
2323
    NullValue = EmitDynamicCastToNull(*this, DestTy);
2324
    CastNull = Builder.GetInsertBlock();
2325

2326
    EmitBranch(CastEnd);
2327
  }
2328

2329
  EmitBlock(CastEnd);
2330

2331
  if (CastNull) {
2332
    llvm::PHINode *PHI = Builder.CreatePHI(Value->getType(), 2);
2333
    PHI->addIncoming(Value, CastNotNull);
2334
    PHI->addIncoming(NullValue, CastNull);
2335

2336
    Value = PHI;
2337
  }
2338

2339
  return Value;
2340
}
2341

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