xref: /external/clang/lib/Sema/SemaExprCXX.cpp

//===--- SemaExprCXX.cpp - Semantic Analysis for Expressions --------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
///
/// \file
/// \brief Implements semantic analysis for C++ expressions.
///
//===----------------------------------------------------------------------===//

#include "clang/Sema/SemaInternal.h"
#include "TreeTransform.h"
#include "TypeLocBuilder.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/ASTLambda.h"
#include "clang/AST/CXXInheritance.h"
#include "clang/AST/CharUnits.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/ExprCXX.h"
#include "clang/AST/ExprObjC.h"
#include "clang/AST/RecursiveASTVisitor.h"
#include "clang/AST/TypeLoc.h"
#include "clang/Basic/PartialDiagnostic.h"
#include "clang/Basic/TargetInfo.h"
#include "clang/Lex/Preprocessor.h"
#include "clang/Sema/DeclSpec.h"
#include "clang/Sema/Initialization.h"
#include "clang/Sema/Lookup.h"
#include "clang/Sema/ParsedTemplate.h"
#include "clang/Sema/Scope.h"
#include "clang/Sema/ScopeInfo.h"
#include "clang/Sema/SemaLambda.h"
#include "clang/Sema/TemplateDeduction.h"
#include "llvm/ADT/APInt.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/Support/ErrorHandling.h"
using namespace clang;
using namespace sema;

/// \brief Handle the result of the special case name lookup for inheriting
/// constructor declarations. 'NS::X::X' and 'NS::X<...>::X' are treated as
/// constructor names in member using declarations, even if 'X' is not the
/// name of the corresponding type.
ParsedType Sema::getInheritingConstructorName(CXXScopeSpec &SS,
                                              SourceLocation NameLoc,
                                              IdentifierInfo &Name) {
  NestedNameSpecifier *NNS = SS.getScopeRep();

  // Convert the nested-name-specifier into a type.
  QualType Type;
  switch (NNS->getKind()) {
  case NestedNameSpecifier::TypeSpec:
  case NestedNameSpecifier::TypeSpecWithTemplate:
    Type = QualType(NNS->getAsType(), 0);
    break;

  case NestedNameSpecifier::Identifier:
    // Strip off the last layer of the nested-name-specifier and build a
    // typename type for it.
    assert(NNS->getAsIdentifier() == &Name && "not a constructor name");
    Type = Context.getDependentNameType(ETK_None, NNS->getPrefix(),
                                        NNS->getAsIdentifier());
    break;

  case NestedNameSpecifier::Global:
  case NestedNameSpecifier::Super:
  case NestedNameSpecifier::Namespace:
  case NestedNameSpecifier::NamespaceAlias:
    llvm_unreachable("Nested name specifier is not a type for inheriting ctor");
  }

  // This reference to the type is located entirely at the location of the
  // final identifier in the qualified-id.
  return CreateParsedType(Type,
                          Context.getTrivialTypeSourceInfo(Type, NameLoc));
}

ParsedType Sema::getDestructorName(SourceLocation TildeLoc,
                                   IdentifierInfo &II,
                                   SourceLocation NameLoc,
                                   Scope *S, CXXScopeSpec &SS,
                                   ParsedType ObjectTypePtr,
                                   bool EnteringContext) {
  // Determine where to perform name lookup.

  // FIXME: This area of the standard is very messy, and the current
  // wording is rather unclear about which scopes we search for the
  // destructor name; see core issues 399 and 555. Issue 399 in
  // particular shows where the current description of destructor name
  // lookup is completely out of line with existing practice, e.g.,
  // this appears to be ill-formed:
  //
  //   namespace N {
  //     template <typename T> struct S {
  //       ~S();
  //     };
  //   }
  //
  //   void f(N::S<int>* s) {
  //     s->N::S<int>::~S();
  //   }
  //
  // See also PR6358 and PR6359.
  // For this reason, we're currently only doing the C++03 version of this
  // code; the C++0x version has to wait until we get a proper spec.
  QualType SearchType;
  DeclContext *LookupCtx = nullptr;
  bool isDependent = false;
  bool LookInScope = false;

  if (SS.isInvalid())
    return nullptr;

  // If we have an object type, it's because we are in a
  // pseudo-destructor-expression or a member access expression, and
  // we know what type we're looking for.
  if (ObjectTypePtr)
    SearchType = GetTypeFromParser(ObjectTypePtr);

  if (SS.isSet()) {
    NestedNameSpecifier *NNS = SS.getScopeRep();

    bool AlreadySearched = false;
    bool LookAtPrefix = true;
    // C++11 [basic.lookup.qual]p6:
    //   If a pseudo-destructor-name (5.2.4) contains a nested-name-specifier,
    //   the type-names are looked up as types in the scope designated by the
    //   nested-name-specifier. Similarly, in a qualified-id of the form:
    //
    //     nested-name-specifier[opt] class-name :: ~ class-name
    //
    //   the second class-name is looked up in the same scope as the first.
    //
    // Here, we determine whether the code below is permitted to look at the
    // prefix of the nested-name-specifier.
    DeclContext *DC = computeDeclContext(SS, EnteringContext);
    if (DC && DC->isFileContext()) {
      AlreadySearched = true;
      LookupCtx = DC;
      isDependent = false;
    } else if (DC && isa<CXXRecordDecl>(DC)) {
      LookAtPrefix = false;
      LookInScope = true;
    }

    // The second case from the C++03 rules quoted further above.
    NestedNameSpecifier *Prefix = nullptr;
    if (AlreadySearched) {
      // Nothing left to do.
    } else if (LookAtPrefix && (Prefix = NNS->getPrefix())) {
      CXXScopeSpec PrefixSS;
      PrefixSS.Adopt(NestedNameSpecifierLoc(Prefix, SS.location_data()));
      LookupCtx = computeDeclContext(PrefixSS, EnteringContext);
      isDependent = isDependentScopeSpecifier(PrefixSS);
    } else if (ObjectTypePtr) {
      LookupCtx = computeDeclContext(SearchType);
      isDependent = SearchType->isDependentType();
    } else {
      LookupCtx = computeDeclContext(SS, EnteringContext);
      isDependent = LookupCtx && LookupCtx->isDependentContext();
    }
  } else if (ObjectTypePtr) {
    // C++ [basic.lookup.classref]p3:
    //   If the unqualified-id is ~type-name, the type-name is looked up
    //   in the context of the entire postfix-expression. If the type T
    //   of the object expression is of a class type C, the type-name is
    //   also looked up in the scope of class C. At least one of the
    //   lookups shall find a name that refers to (possibly
    //   cv-qualified) T.
    LookupCtx = computeDeclContext(SearchType);
    isDependent = SearchType->isDependentType();
    assert((isDependent || !SearchType->isIncompleteType()) &&
           "Caller should have completed object type");

    LookInScope = true;
  } else {
    // Perform lookup into the current scope (only).
    LookInScope = true;
  }

  TypeDecl *NonMatchingTypeDecl = nullptr;
  LookupResult Found(*this, &II, NameLoc, LookupOrdinaryName);
  for (unsigned Step = 0; Step != 2; ++Step) {
    // Look for the name first in the computed lookup context (if we
    // have one) and, if that fails to find a match, in the scope (if
    // we're allowed to look there).
    Found.clear();
    if (Step == 0 && LookupCtx)
      LookupQualifiedName(Found, LookupCtx);
    else if (Step == 1 && LookInScope && S)
      LookupName(Found, S);
    else
      continue;

    // FIXME: Should we be suppressing ambiguities here?
    if (Found.isAmbiguous())
      return nullptr;

    if (TypeDecl *Type = Found.getAsSingle<TypeDecl>()) {
      QualType T = Context.getTypeDeclType(Type);
      MarkAnyDeclReferenced(Type->getLocation(), Type, /*OdrUse=*/false);

      if (SearchType.isNull() || SearchType->isDependentType() ||
          Context.hasSameUnqualifiedType(T, SearchType)) {
        // We found our type!

        return CreateParsedType(T,
                                Context.getTrivialTypeSourceInfo(T, NameLoc));
      }

      if (!SearchType.isNull())
        NonMatchingTypeDecl = Type;
    }

    // If the name that we found is a class template name, and it is
    // the same name as the template name in the last part of the
    // nested-name-specifier (if present) or the object type, then
    // this is the destructor for that class.
    // FIXME: This is a workaround until we get real drafting for core
    // issue 399, for which there isn't even an obvious direction.
    if (ClassTemplateDecl *Template = Found.getAsSingle<ClassTemplateDecl>()) {
      QualType MemberOfType;
      if (SS.isSet()) {
        if (DeclContext *Ctx = computeDeclContext(SS, EnteringContext)) {
          // Figure out the type of the context, if it has one.
          if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx))
            MemberOfType = Context.getTypeDeclType(Record);
        }
      }
      if (MemberOfType.isNull())
        MemberOfType = SearchType;

      if (MemberOfType.isNull())
        continue;

      // We're referring into a class template specialization. If the
      // class template we found is the same as the template being
      // specialized, we found what we are looking for.
      if (const RecordType *Record = MemberOfType->getAs<RecordType>()) {
        if (ClassTemplateSpecializationDecl *Spec
              = dyn_cast<ClassTemplateSpecializationDecl>(Record->getDecl())) {
          if (Spec->getSpecializedTemplate()->getCanonicalDecl() ==
                Template->getCanonicalDecl())
            return CreateParsedType(
                MemberOfType,
                Context.getTrivialTypeSourceInfo(MemberOfType, NameLoc));
        }

        continue;
      }

      // We're referring to an unresolved class template
      // specialization. Determine whether we class template we found
      // is the same as the template being specialized or, if we don't
      // know which template is being specialized, that it at least
      // has the same name.
      if (const TemplateSpecializationType *SpecType
            = MemberOfType->getAs<TemplateSpecializationType>()) {
        TemplateName SpecName = SpecType->getTemplateName();

        // The class template we found is the same template being
        // specialized.
        if (TemplateDecl *SpecTemplate = SpecName.getAsTemplateDecl()) {
          if (SpecTemplate->getCanonicalDecl() == Template->getCanonicalDecl())
            return CreateParsedType(
                MemberOfType,
                Context.getTrivialTypeSourceInfo(MemberOfType, NameLoc));

          continue;
        }

        // The class template we found has the same name as the
        // (dependent) template name being specialized.
        if (DependentTemplateName *DepTemplate
                                    = SpecName.getAsDependentTemplateName()) {
          if (DepTemplate->isIdentifier() &&
              DepTemplate->getIdentifier() == Template->getIdentifier())
            return CreateParsedType(
                MemberOfType,
                Context.getTrivialTypeSourceInfo(MemberOfType, NameLoc));

          continue;
        }
      }
    }
  }

  if (isDependent) {
    // We didn't find our type, but that's okay: it's dependent
    // anyway.

    // FIXME: What if we have no nested-name-specifier?
    QualType T = CheckTypenameType(ETK_None, SourceLocation(),
                                   SS.getWithLocInContext(Context),
                                   II, NameLoc);
    return ParsedType::make(T);
  }

  if (NonMatchingTypeDecl) {
    QualType T = Context.getTypeDeclType(NonMatchingTypeDecl);
    Diag(NameLoc, diag::err_destructor_expr_type_mismatch)
      << T << SearchType;
    Diag(NonMatchingTypeDecl->getLocation(), diag::note_destructor_type_here)
      << T;
  } else if (ObjectTypePtr)
    Diag(NameLoc, diag::err_ident_in_dtor_not_a_type)
      << &II;
  else {
    SemaDiagnosticBuilder DtorDiag = Diag(NameLoc,
                                          diag::err_destructor_class_name);
    if (S) {
      const DeclContext *Ctx = S->getEntity();
      if (const CXXRecordDecl *Class = dyn_cast_or_null<CXXRecordDecl>(Ctx))
        DtorDiag << FixItHint::CreateReplacement(SourceRange(NameLoc),
                                                 Class->getNameAsString());
    }
  }

  return nullptr;
}

ParsedType Sema::getDestructorType(const DeclSpec& DS, ParsedType ObjectType) {
    if (DS.getTypeSpecType() == DeclSpec::TST_error || !ObjectType)
      return nullptr;
    assert(DS.getTypeSpecType() == DeclSpec::TST_decltype
           && "only get destructor types from declspecs");
    QualType T = BuildDecltypeType(DS.getRepAsExpr(), DS.getTypeSpecTypeLoc());
    QualType SearchType = GetTypeFromParser(ObjectType);
    if (SearchType->isDependentType() || Context.hasSameUnqualifiedType(SearchType, T)) {
      return ParsedType::make(T);
    }

    Diag(DS.getTypeSpecTypeLoc(), diag::err_destructor_expr_type_mismatch)
      << T << SearchType;
    return nullptr;
}

bool Sema::checkLiteralOperatorId(const CXXScopeSpec &SS,
                                  const UnqualifiedId &Name) {
  assert(Name.getKind() == UnqualifiedId::IK_LiteralOperatorId);

  if (!SS.isValid())
    return false;

  switch (SS.getScopeRep()->getKind()) {
  case NestedNameSpecifier::Identifier:
  case NestedNameSpecifier::TypeSpec:
  case NestedNameSpecifier::TypeSpecWithTemplate:
    // Per C++11 [over.literal]p2, literal operators can only be declared at
    // namespace scope. Therefore, this unqualified-id cannot name anything.
    // Reject it early, because we have no AST representation for this in the
    // case where the scope is dependent.
    Diag(Name.getLocStart(), diag::err_literal_operator_id_outside_namespace)
      << SS.getScopeRep();
    return true;

  case NestedNameSpecifier::Global:
  case NestedNameSpecifier::Super:
  case NestedNameSpecifier::Namespace:
  case NestedNameSpecifier::NamespaceAlias:
    return false;
  }

  llvm_unreachable("unknown nested name specifier kind");
}

/// \brief Build a C++ typeid expression with a type operand.
ExprResult Sema::BuildCXXTypeId(QualType TypeInfoType,
                                SourceLocation TypeidLoc,
                                TypeSourceInfo *Operand,
                                SourceLocation RParenLoc) {
  // C++ [expr.typeid]p4:
  //   The top-level cv-qualifiers of the lvalue expression or the type-id
  //   that is the operand of typeid are always ignored.
  //   If the type of the type-id is a class type or a reference to a class
  //   type, the class shall be completely-defined.
  Qualifiers Quals;
  QualType T
    = Context.getUnqualifiedArrayType(Operand->getType().getNonReferenceType(),
                                      Quals);
  if (T->getAs<RecordType>() &&
      RequireCompleteType(TypeidLoc, T, diag::err_incomplete_typeid))
    return ExprError();

  if (T->isVariablyModifiedType())
    return ExprError(Diag(TypeidLoc, diag::err_variably_modified_typeid) << T);

  return new (Context) CXXTypeidExpr(TypeInfoType.withConst(), Operand,
                                     SourceRange(TypeidLoc, RParenLoc));
}

/// \brief Build a C++ typeid expression with an expression operand.
ExprResult Sema::BuildCXXTypeId(QualType TypeInfoType,
                                SourceLocation TypeidLoc,
                                Expr *E,
                                SourceLocation RParenLoc) {
  bool WasEvaluated = false;
  if (E && !E->isTypeDependent()) {
    if (E->getType()->isPlaceholderType()) {
      ExprResult result = CheckPlaceholderExpr(E);
      if (result.isInvalid()) return ExprError();
      E = result.get();
    }

    QualType T = E->getType();
    if (const RecordType *RecordT = T->getAs<RecordType>()) {
      CXXRecordDecl *RecordD = cast<CXXRecordDecl>(RecordT->getDecl());
      // C++ [expr.typeid]p3:
      //   [...] If the type of the expression is a class type, the class
      //   shall be completely-defined.
      if (RequireCompleteType(TypeidLoc, T, diag::err_incomplete_typeid))
        return ExprError();

      // C++ [expr.typeid]p3:
      //   When typeid is applied to an expression other than an glvalue of a
      //   polymorphic class type [...] [the] expression is an unevaluated
      //   operand. [...]
      if (RecordD->isPolymorphic() && E->isGLValue()) {
        // The subexpression is potentially evaluated; switch the context
        // and recheck the subexpression.
        ExprResult Result = TransformToPotentiallyEvaluated(E);
        if (Result.isInvalid()) return ExprError();
        E = Result.get();

        // We require a vtable to query the type at run time.
        MarkVTableUsed(TypeidLoc, RecordD);
        WasEvaluated = true;
      }
    }

    // C++ [expr.typeid]p4:
    //   [...] If the type of the type-id is a reference to a possibly
    //   cv-qualified type, the result of the typeid expression refers to a
    //   std::type_info object representing the cv-unqualified referenced
    //   type.
    Qualifiers Quals;
    QualType UnqualT = Context.getUnqualifiedArrayType(T, Quals);
    if (!Context.hasSameType(T, UnqualT)) {
      T = UnqualT;
      E = ImpCastExprToType(E, UnqualT, CK_NoOp, E->getValueKind()).get();
    }
  }

  if (E->getType()->isVariablyModifiedType())
    return ExprError(Diag(TypeidLoc, diag::err_variably_modified_typeid)
                     << E->getType());
  else if (ActiveTemplateInstantiations.empty() &&
           E->HasSideEffects(Context, WasEvaluated)) {
    // The expression operand for typeid is in an unevaluated expression
    // context, so side effects could result in unintended consequences.
    Diag(E->getExprLoc(), WasEvaluated
                              ? diag::warn_side_effects_typeid
                              : diag::warn_side_effects_unevaluated_context);
  }

  return new (Context) CXXTypeidExpr(TypeInfoType.withConst(), E,
                                     SourceRange(TypeidLoc, RParenLoc));
}

/// ActOnCXXTypeidOfType - Parse typeid( type-id ) or typeid (expression);
ExprResult
Sema::ActOnCXXTypeid(SourceLocation OpLoc, SourceLocation LParenLoc,
                     bool isType, void *TyOrExpr, SourceLocation RParenLoc) {
  // Find the std::type_info type.
  if (!getStdNamespace())
    return ExprError(Diag(OpLoc, diag::err_need_header_before_typeid));

  if (!CXXTypeInfoDecl) {
    IdentifierInfo *TypeInfoII = &PP.getIdentifierTable().get("type_info");
    LookupResult R(*this, TypeInfoII, SourceLocation(), LookupTagName);
    LookupQualifiedName(R, getStdNamespace());
    CXXTypeInfoDecl = R.getAsSingle<RecordDecl>();
    // Microsoft's typeinfo doesn't have type_info in std but in the global
    // namespace if _HAS_EXCEPTIONS is defined to 0. See PR13153.
    if (!CXXTypeInfoDecl && LangOpts.MSVCCompat) {
      LookupQualifiedName(R, Context.getTranslationUnitDecl());
      CXXTypeInfoDecl = R.getAsSingle<RecordDecl>();
    }
    if (!CXXTypeInfoDecl)
      return ExprError(Diag(OpLoc, diag::err_need_header_before_typeid));
  }

  if (!getLangOpts().RTTI) {
    return ExprError(Diag(OpLoc, diag::err_no_typeid_with_fno_rtti));
  }

  QualType TypeInfoType = Context.getTypeDeclType(CXXTypeInfoDecl);

  if (isType) {
    // The operand is a type; handle it as such.
    TypeSourceInfo *TInfo = nullptr;
    QualType T = GetTypeFromParser(ParsedType::getFromOpaquePtr(TyOrExpr),
                                   &TInfo);
    if (T.isNull())
      return ExprError();

    if (!TInfo)
      TInfo = Context.getTrivialTypeSourceInfo(T, OpLoc);

    return BuildCXXTypeId(TypeInfoType, OpLoc, TInfo, RParenLoc);
  }

  // The operand is an expression.
  return BuildCXXTypeId(TypeInfoType, OpLoc, (Expr*)TyOrExpr, RParenLoc);
}

/// Grabs __declspec(uuid()) off a type, or returns 0 if we cannot resolve to
/// a single GUID.
static void
getUuidAttrOfType(Sema &SemaRef, QualType QT,
                  llvm::SmallSetVector<const UuidAttr *, 1> &UuidAttrs) {
  // Optionally remove one level of pointer, reference or array indirection.
  const Type *Ty = QT.getTypePtr();
  if (QT->isPointerType() || QT->isReferenceType())
    Ty = QT->getPointeeType().getTypePtr();
  else if (QT->isArrayType())
    Ty = Ty->getBaseElementTypeUnsafe();

  const auto *RD = Ty->getAsCXXRecordDecl();
  if (!RD)
    return;

  if (const auto *Uuid = RD->getMostRecentDecl()->getAttr<UuidAttr>()) {
    UuidAttrs.insert(Uuid);
    return;
  }

  // __uuidof can grab UUIDs from template arguments.
  if (const auto *CTSD = dyn_cast<ClassTemplateSpecializationDecl>(RD)) {
    const TemplateArgumentList &TAL = CTSD->getTemplateArgs();
    for (const TemplateArgument &TA : TAL.asArray()) {
      const UuidAttr *UuidForTA = nullptr;
      if (TA.getKind() == TemplateArgument::Type)
        getUuidAttrOfType(SemaRef, TA.getAsType(), UuidAttrs);
      else if (TA.getKind() == TemplateArgument::Declaration)
        getUuidAttrOfType(SemaRef, TA.getAsDecl()->getType(), UuidAttrs);

      if (UuidForTA)
        UuidAttrs.insert(UuidForTA);
    }
  }
}

/// \brief Build a Microsoft __uuidof expression with a type operand.
ExprResult Sema::BuildCXXUuidof(QualType TypeInfoType,
                                SourceLocation TypeidLoc,
                                TypeSourceInfo *Operand,
                                SourceLocation RParenLoc) {
  StringRef UuidStr;
  if (!Operand->getType()->isDependentType()) {
    llvm::SmallSetVector<const UuidAttr *, 1> UuidAttrs;
    getUuidAttrOfType(*this, Operand->getType(), UuidAttrs);
    if (UuidAttrs.empty())
      return ExprError(Diag(TypeidLoc, diag::err_uuidof_without_guid));
    if (UuidAttrs.size() > 1)
      return ExprError(Diag(TypeidLoc, diag::err_uuidof_with_multiple_guids));
    UuidStr = UuidAttrs.back()->getGuid();
  }

  return new (Context) CXXUuidofExpr(TypeInfoType.withConst(), Operand, UuidStr,
                                     SourceRange(TypeidLoc, RParenLoc));
}

/// \brief Build a Microsoft __uuidof expression with an expression operand.
ExprResult Sema::BuildCXXUuidof(QualType TypeInfoType,
                                SourceLocation TypeidLoc,
                                Expr *E,
                                SourceLocation RParenLoc) {
  StringRef UuidStr;
  if (!E->getType()->isDependentType()) {
    if (E->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) {
      UuidStr = "00000000-0000-0000-0000-000000000000";
    } else {
      llvm::SmallSetVector<const UuidAttr *, 1> UuidAttrs;
      getUuidAttrOfType(*this, E->getType(), UuidAttrs);
      if (UuidAttrs.empty())
        return ExprError(Diag(TypeidLoc, diag::err_uuidof_without_guid));
      if (UuidAttrs.size() > 1)
        return ExprError(Diag(TypeidLoc, diag::err_uuidof_with_multiple_guids));
      UuidStr = UuidAttrs.back()->getGuid();
    }
  }

  return new (Context) CXXUuidofExpr(TypeInfoType.withConst(), E, UuidStr,
                                     SourceRange(TypeidLoc, RParenLoc));
}

/// ActOnCXXUuidof - Parse __uuidof( type-id ) or __uuidof (expression);
ExprResult
Sema::ActOnCXXUuidof(SourceLocation OpLoc, SourceLocation LParenLoc,
                     bool isType, void *TyOrExpr, SourceLocation RParenLoc) {
  // If MSVCGuidDecl has not been cached, do the lookup.
  if (!MSVCGuidDecl) {
    IdentifierInfo *GuidII = &PP.getIdentifierTable().get("_GUID");
    LookupResult R(*this, GuidII, SourceLocation(), LookupTagName);
    LookupQualifiedName(R, Context.getTranslationUnitDecl());
    MSVCGuidDecl = R.getAsSingle<RecordDecl>();
    if (!MSVCGuidDecl)
      return ExprError(Diag(OpLoc, diag::err_need_header_before_ms_uuidof));
  }

  QualType GuidType = Context.getTypeDeclType(MSVCGuidDecl);

  if (isType) {
    // The operand is a type; handle it as such.
    TypeSourceInfo *TInfo = nullptr;
    QualType T = GetTypeFromParser(ParsedType::getFromOpaquePtr(TyOrExpr),
                                   &TInfo);
    if (T.isNull())
      return ExprError();

    if (!TInfo)
      TInfo = Context.getTrivialTypeSourceInfo(T, OpLoc);

    return BuildCXXUuidof(GuidType, OpLoc, TInfo, RParenLoc);
  }

  // The operand is an expression.
  return BuildCXXUuidof(GuidType, OpLoc, (Expr*)TyOrExpr, RParenLoc);
}

/// ActOnCXXBoolLiteral - Parse {true,false} literals.
ExprResult
Sema::ActOnCXXBoolLiteral(SourceLocation OpLoc, tok::TokenKind Kind) {
  assert((Kind == tok::kw_true || Kind == tok::kw_false) &&
         "Unknown C++ Boolean value!");
  return new (Context)
      CXXBoolLiteralExpr(Kind == tok::kw_true, Context.BoolTy, OpLoc);
}

/// ActOnCXXNullPtrLiteral - Parse 'nullptr'.
ExprResult
Sema::ActOnCXXNullPtrLiteral(SourceLocation Loc) {
  return new (Context) CXXNullPtrLiteralExpr(Context.NullPtrTy, Loc);
}

/// ActOnCXXThrow - Parse throw expressions.
ExprResult
Sema::ActOnCXXThrow(Scope *S, SourceLocation OpLoc, Expr *Ex) {
  bool IsThrownVarInScope = false;
  if (Ex) {
    // C++0x [class.copymove]p31:
    //   When certain criteria are met, an implementation is allowed to omit the
    //   copy/move construction of a class object [...]
    //
    //     - in a throw-expression, when the operand is the name of a
    //       non-volatile automatic object (other than a function or catch-
    //       clause parameter) whose scope does not extend beyond the end of the
    //       innermost enclosing try-block (if there is one), the copy/move
    //       operation from the operand to the exception object (15.1) can be
    //       omitted by constructing the automatic object directly into the
    //       exception object
    if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Ex->IgnoreParens()))
      if (VarDecl *Var = dyn_cast<VarDecl>(DRE->getDecl())) {
        if (Var->hasLocalStorage() && !Var->getType().isVolatileQualified()) {
          for( ; S; S = S->getParent()) {
            if (S->isDeclScope(Var)) {
              IsThrownVarInScope = true;
              break;
            }

            if (S->getFlags() &
                (Scope::FnScope | Scope::ClassScope | Scope::BlockScope |
                 Scope::FunctionPrototypeScope | Scope::ObjCMethodScope |
                 Scope::TryScope))
              break;
          }
        }
      }
  }

  return BuildCXXThrow(OpLoc, Ex, IsThrownVarInScope);
}

ExprResult Sema::BuildCXXThrow(SourceLocation OpLoc, Expr *Ex,
                               bool IsThrownVarInScope) {
  // Don't report an error if 'throw' is used in system headers.
  if (!getLangOpts().CXXExceptions &&
      !getSourceManager().isInSystemHeader(OpLoc))
    Diag(OpLoc, diag::err_exceptions_disabled) << "throw";

  if (getCurScope() && getCurScope()->isOpenMPSimdDirectiveScope())
    Diag(OpLoc, diag::err_omp_simd_region_cannot_use_stmt) << "throw";

  if (Ex && !Ex->isTypeDependent()) {
    QualType ExceptionObjectTy = Context.getExceptionObjectType(Ex->getType());
    if (CheckCXXThrowOperand(OpLoc, ExceptionObjectTy, Ex))
      return ExprError();

    // Initialize the exception result.  This implicitly weeds out
    // abstract types or types with inaccessible copy constructors.

    // C++0x [class.copymove]p31:
    //   When certain criteria are met, an implementation is allowed to omit the
    //   copy/move construction of a class object [...]
    //
    //     - in a throw-expression, when the operand is the name of a
    //       non-volatile automatic object (other than a function or
    //       catch-clause
    //       parameter) whose scope does not extend beyond the end of the
    //       innermost enclosing try-block (if there is one), the copy/move
    //       operation from the operand to the exception object (15.1) can be
    //       omitted by constructing the automatic object directly into the
    //       exception object
    const VarDecl *NRVOVariable = nullptr;
    if (IsThrownVarInScope)
      NRVOVariable = getCopyElisionCandidate(QualType(), Ex, false);

    InitializedEntity Entity = InitializedEntity::InitializeException(
        OpLoc, ExceptionObjectTy,
        /*NRVO=*/NRVOVariable != nullptr);
    ExprResult Res = PerformMoveOrCopyInitialization(
        Entity, NRVOVariable, QualType(), Ex, IsThrownVarInScope);
    if (Res.isInvalid())
      return ExprError();
    Ex = Res.get();
  }

  return new (Context)
      CXXThrowExpr(Ex, Context.VoidTy, OpLoc, IsThrownVarInScope);
}

static void
collectPublicBases(CXXRecordDecl *RD,
                   llvm::DenseMap<CXXRecordDecl *, unsigned> &SubobjectsSeen,
                   llvm::SmallPtrSetImpl<CXXRecordDecl *> &VBases,
                   llvm::SetVector<CXXRecordDecl *> &PublicSubobjectsSeen,
                   bool ParentIsPublic) {
  for (const CXXBaseSpecifier &BS : RD->bases()) {
    CXXRecordDecl *BaseDecl = BS.getType()->getAsCXXRecordDecl();
    bool NewSubobject;
    // Virtual bases constitute the same subobject.  Non-virtual bases are
    // always distinct subobjects.
    if (BS.isVirtual())
      NewSubobject = VBases.insert(BaseDecl).second;
    else
      NewSubobject = true;

    if (NewSubobject)
      ++SubobjectsSeen[BaseDecl];

    // Only add subobjects which have public access throughout the entire chain.
    bool PublicPath = ParentIsPublic && BS.getAccessSpecifier() == AS_public;
    if (PublicPath)
      PublicSubobjectsSeen.insert(BaseDecl);

    // Recurse on to each base subobject.
    collectPublicBases(BaseDecl, SubobjectsSeen, VBases, PublicSubobjectsSeen,
                       PublicPath);
  }
}

static void getUnambiguousPublicSubobjects(
    CXXRecordDecl *RD, llvm::SmallVectorImpl<CXXRecordDecl *> &Objects) {
  llvm::DenseMap<CXXRecordDecl *, unsigned> SubobjectsSeen;
  llvm::SmallSet<CXXRecordDecl *, 2> VBases;
  llvm::SetVector<CXXRecordDecl *> PublicSubobjectsSeen;
  SubobjectsSeen[RD] = 1;
  PublicSubobjectsSeen.insert(RD);
  collectPublicBases(RD, SubobjectsSeen, VBases, PublicSubobjectsSeen,
                     /*ParentIsPublic=*/true);

  for (CXXRecordDecl *PublicSubobject : PublicSubobjectsSeen) {
    // Skip ambiguous objects.
    if (SubobjectsSeen[PublicSubobject] > 1)
      continue;

    Objects.push_back(PublicSubobject);
  }
}

/// CheckCXXThrowOperand - Validate the operand of a throw.
bool Sema::CheckCXXThrowOperand(SourceLocation ThrowLoc,
                                QualType ExceptionObjectTy, Expr *E) {
  //   If the type of the exception would be an incomplete type or a pointer
  //   to an incomplete type other than (cv) void the program is ill-formed.
  QualType Ty = ExceptionObjectTy;
  bool isPointer = false;
  if (const PointerType* Ptr = Ty->getAs<PointerType>()) {
    Ty = Ptr->getPointeeType();
    isPointer = true;
  }
  if (!isPointer || !Ty->isVoidType()) {
    if (RequireCompleteType(ThrowLoc, Ty,
                            isPointer ? diag::err_throw_incomplete_ptr
                                      : diag::err_throw_incomplete,
                            E->getSourceRange()))
      return true;

    if (RequireNonAbstractType(ThrowLoc, ExceptionObjectTy,
                               diag::err_throw_abstract_type, E))
      return true;
  }

  // If the exception has class type, we need additional handling.
  CXXRecordDecl *RD = Ty->getAsCXXRecordDecl();
  if (!RD)
    return false;

  // If we are throwing a polymorphic class type or pointer thereof,
  // exception handling will make use of the vtable.
  MarkVTableUsed(ThrowLoc, RD);

  // If a pointer is thrown, the referenced object will not be destroyed.
  if (isPointer)
    return false;

  // If the class has a destructor, we must be able to call it.
  if (!RD->hasIrrelevantDestructor()) {
    if (CXXDestructorDecl *Destructor = LookupDestructor(RD)) {
      MarkFunctionReferenced(E->getExprLoc(), Destructor);
      CheckDestructorAccess(E->getExprLoc(), Destructor,
                            PDiag(diag::err_access_dtor_exception) << Ty);
      if (DiagnoseUseOfDecl(Destructor, E->getExprLoc()))
        return true;
    }
  }

  // The MSVC ABI creates a list of all types which can catch the exception
  // object.  This list also references the appropriate copy constructor to call
  // if the object is caught by value and has a non-trivial copy constructor.
  if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
    // We are only interested in the public, unambiguous bases contained within
    // the exception object.  Bases which are ambiguous or otherwise
    // inaccessible are not catchable types.
    llvm::SmallVector<CXXRecordDecl *, 2> UnambiguousPublicSubobjects;
    getUnambiguousPublicSubobjects(RD, UnambiguousPublicSubobjects);

    for (CXXRecordDecl *Subobject : UnambiguousPublicSubobjects) {
      // Attempt to lookup the copy constructor.  Various pieces of machinery
      // will spring into action, like template instantiation, which means this
      // cannot be a simple walk of the class's decls.  Instead, we must perform
      // lookup and overload resolution.
      CXXConstructorDecl *CD = LookupCopyingConstructor(Subobject, 0);
      if (!CD)
        continue;

      // Mark the constructor referenced as it is used by this throw expression.
      MarkFunctionReferenced(E->getExprLoc(), CD);

      // Skip this copy constructor if it is trivial, we don't need to record it
      // in the catchable type data.
      if (CD->isTrivial())
        continue;

      // The copy constructor is non-trivial, create a mapping from this class
      // type to this constructor.
      // N.B.  The selection of copy constructor is not sensitive to this
      // particular throw-site.  Lookup will be performed at the catch-site to
      // ensure that the copy constructor is, in fact, accessible (via
      // friendship or any other means).
      Context.addCopyConstructorForExceptionObject(Subobject, CD);

      // We don't keep the instantiated default argument expressions around so
      // we must rebuild them here.
      for (unsigned I = 1, E = CD->getNumParams(); I != E; ++I) {
        // Skip any default arguments that we've already instantiated.
        if (Context.getDefaultArgExprForConstructor(CD, I))
          continue;

        Expr *DefaultArg =
            BuildCXXDefaultArgExpr(ThrowLoc, CD, CD->getParamDecl(I)).get();
        Context.addDefaultArgExprForConstructor(CD, I, DefaultArg);
      }
    }
  }

  return false;
}

static QualType adjustCVQualifiersForCXXThisWithinLambda(
    ArrayRef<FunctionScopeInfo *> FunctionScopes, QualType ThisTy,
    DeclContext *CurSemaContext, ASTContext &ASTCtx) {

  QualType ClassType = ThisTy->getPointeeType();
  LambdaScopeInfo *CurLSI = nullptr;
  DeclContext *CurDC = CurSemaContext;

  // Iterate through the stack of lambdas starting from the innermost lambda to
  // the outermost lambda, checking if '*this' is ever captured by copy - since
  // that could change the cv-qualifiers of the '*this' object.
  // The object referred to by '*this' starts out with the cv-qualifiers of its
  // member function.  We then start with the innermost lambda and iterate
  // outward checking to see if any lambda performs a by-copy capture of '*this'
  // - and if so, any nested lambda must respect the 'constness' of that
  // capturing lamdbda's call operator.
  //

  // The issue is that we cannot rely entirely on the FunctionScopeInfo stack
  // since ScopeInfos are pushed on during parsing and treetransforming. But
  // since a generic lambda's call operator can be instantiated anywhere (even
  // end of the TU) we need to be able to examine its enclosing lambdas and so
  // we use the DeclContext to get a hold of the closure-class and query it for
  // capture information.  The reason we don't just resort to always using the
  // DeclContext chain is that it is only mature for lambda expressions
  // enclosing generic lambda's call operators that are being instantiated.

  for (int I = FunctionScopes.size();
       I-- && isa<LambdaScopeInfo>(FunctionScopes[I]);
       CurDC = getLambdaAwareParentOfDeclContext(CurDC)) {
    CurLSI = cast<LambdaScopeInfo>(FunctionScopes[I]);

    if (!CurLSI->isCXXThisCaptured())
        continue;

    auto C = CurLSI->getCXXThisCapture();

    if (C.isCopyCapture()) {
      ClassType.removeLocalCVRQualifiers(Qualifiers::CVRMask);
      if (CurLSI->CallOperator->isConst())
        ClassType.addConst();
      return ASTCtx.getPointerType(ClassType);
    }
  }
  // We've run out of ScopeInfos but check if CurDC is a lambda (which can
  // happen during instantiation of generic lambdas)
  if (isLambdaCallOperator(CurDC)) {
    assert(CurLSI);
    assert(isGenericLambdaCallOperatorSpecialization(CurLSI->CallOperator));
    assert(CurDC == getLambdaAwareParentOfDeclContext(CurLSI->CallOperator));

    auto IsThisCaptured =
        [](CXXRecordDecl *Closure, bool &IsByCopy, bool &IsConst) {
      IsConst = false;
      IsByCopy = false;
      for (auto &&C : Closure->captures()) {
        if (C.capturesThis()) {
          if (C.getCaptureKind() == LCK_StarThis)
            IsByCopy = true;
          if (Closure->getLambdaCallOperator()->isConst())
            IsConst = true;
          return true;
        }
      }
      return false;
    };

    bool IsByCopyCapture = false;
    bool IsConstCapture = false;
    CXXRecordDecl *Closure = cast<CXXRecordDecl>(CurDC->getParent());
    while (Closure &&
           IsThisCaptured(Closure, IsByCopyCapture, IsConstCapture)) {
      if (IsByCopyCapture) {
        ClassType.removeLocalCVRQualifiers(Qualifiers::CVRMask);
        if (IsConstCapture)
          ClassType.addConst();
        return ASTCtx.getPointerType(ClassType);
      }
      Closure = isLambdaCallOperator(Closure->getParent())
                    ? cast<CXXRecordDecl>(Closure->getParent()->getParent())
                    : nullptr;
    }
  }
  return ASTCtx.getPointerType(ClassType);
}

QualType Sema::getCurrentThisType() {
  DeclContext *DC = getFunctionLevelDeclContext();
  QualType ThisTy = CXXThisTypeOverride;
  if (CXXMethodDecl *method = dyn_cast<CXXMethodDecl>(DC)) {
    if (method && method->isInstance())
      ThisTy = method->getThisType(Context);
  }
  if (ThisTy.isNull()) {
    if (isGenericLambdaCallOperatorSpecialization(CurContext) &&
        CurContext->getParent()->getParent()->isRecord()) {
      // This is a generic lambda call operator that is being instantiated
      // within a default initializer - so use the enclosing class as 'this'.
      // There is no enclosing member function to retrieve the 'this' pointer
      // from.

      // FIXME: This looks wrong. If we're in a lambda within a lambda within a
      // default member initializer, we need to recurse up more parents to find
      // the right context. Looks like we should be walking up to the parent of
      // the closure type, checking whether that is itself a lambda, and if so,
      // recursing, until we reach a class or a function that isn't a lambda
      // call operator. And we should accumulate the constness of *this on the
      // way.

      QualType ClassTy = Context.getTypeDeclType(
          cast<CXXRecordDecl>(CurContext->getParent()->getParent()));
      // There are no cv-qualifiers for 'this' within default initializers,
      // per [expr.prim.general]p4.
      ThisTy = Context.getPointerType(ClassTy);
    }
  }

  // If we are within a lambda's call operator, the cv-qualifiers of 'this'
  // might need to be adjusted if the lambda or any of its enclosing lambda's
  // captures '*this' by copy.
  if (!ThisTy.isNull() && isLambdaCallOperator(CurContext))
    return adjustCVQualifiersForCXXThisWithinLambda(FunctionScopes, ThisTy,
                                                    CurContext, Context);
  return ThisTy;
}

Sema::CXXThisScopeRAII::CXXThisScopeRAII(Sema &S,
                                         Decl *ContextDecl,
                                         unsigned CXXThisTypeQuals,
                                         bool Enabled)
  : S(S), OldCXXThisTypeOverride(S.CXXThisTypeOverride), Enabled(false)
{
  if (!Enabled || !ContextDecl)
    return;

  CXXRecordDecl *Record = nullptr;
  if (ClassTemplateDecl *Template = dyn_cast<ClassTemplateDecl>(ContextDecl))
    Record = Template->getTemplatedDecl();
  else
    Record = cast<CXXRecordDecl>(ContextDecl);

  // We care only for CVR qualifiers here, so cut everything else.
  CXXThisTypeQuals &= Qualifiers::FastMask;
  S.CXXThisTypeOverride
    = S.Context.getPointerType(
        S.Context.getRecordType(Record).withCVRQualifiers(CXXThisTypeQuals));

  this->Enabled = true;
}


Sema::CXXThisScopeRAII::~CXXThisScopeRAII() {
  if (Enabled) {
    S.CXXThisTypeOverride = OldCXXThisTypeOverride;
  }
}

static Expr *captureThis(Sema &S, ASTContext &Context, RecordDecl *RD,
                         QualType ThisTy, SourceLocation Loc,
                         const bool ByCopy) {

  QualType AdjustedThisTy = ThisTy;
  // The type of the corresponding data member (not a 'this' pointer if 'by
  // copy').
  QualType CaptureThisFieldTy = ThisTy;
  if (ByCopy) {
    // If we are capturing the object referred to by '*this' by copy, ignore any
    // cv qualifiers inherited from the type of the member function for the type
    // of the closure-type's corresponding data member and any use of 'this'.
    CaptureThisFieldTy = ThisTy->getPointeeType();
    CaptureThisFieldTy.removeLocalCVRQualifiers(Qualifiers::CVRMask);
    AdjustedThisTy = Context.getPointerType(CaptureThisFieldTy);
  }

  FieldDecl *Field = FieldDecl::Create(
      Context, RD, Loc, Loc, nullptr, CaptureThisFieldTy,
      Context.getTrivialTypeSourceInfo(CaptureThisFieldTy, Loc), nullptr, false,
      ICIS_NoInit);

  Field->setImplicit(true);
  Field->setAccess(AS_private);
  RD->addDecl(Field);
  Expr *This =
      new (Context) CXXThisExpr(Loc, ThisTy, /*isImplicit*/ true);
  if (ByCopy) {
    Expr *StarThis =  S.CreateBuiltinUnaryOp(Loc,
                                      UO_Deref,
                                      This).get();
    InitializedEntity Entity = InitializedEntity::InitializeLambdaCapture(
      nullptr, CaptureThisFieldTy, Loc);
    InitializationKind InitKind = InitializationKind::CreateDirect(Loc, Loc, Loc);
    InitializationSequence Init(S, Entity, InitKind, StarThis);
    ExprResult ER = Init.Perform(S, Entity, InitKind, StarThis);
    if (ER.isInvalid()) return nullptr;
    return ER.get();
  }
  return This;
}

bool Sema::CheckCXXThisCapture(SourceLocation Loc, const bool Explicit,
    bool BuildAndDiagnose, const unsigned *const FunctionScopeIndexToStopAt,
    const bool ByCopy) {
  // We don't need to capture this in an unevaluated context.
  if (isUnevaluatedContext() && !Explicit)
    return true;

  assert((!ByCopy || Explicit) && "cannot implicitly capture *this by value");

  const unsigned MaxFunctionScopesIndex = FunctionScopeIndexToStopAt ?
    *FunctionScopeIndexToStopAt : FunctionScopes.size() - 1;

  // Check that we can capture the *enclosing object* (referred to by '*this')
  // by the capturing-entity/closure (lambda/block/etc) at
  // MaxFunctionScopesIndex-deep on the FunctionScopes stack.

  // Note: The *enclosing object* can only be captured by-value by a
  // closure that is a lambda, using the explicit notation:
  //    [*this] { ... }.
  // Every other capture of the *enclosing object* results in its by-reference
  // capture.

  // For a closure 'L' (at MaxFunctionScopesIndex in the FunctionScopes
  // stack), we can capture the *enclosing object* only if:
  // - 'L' has an explicit byref or byval capture of the *enclosing object*
  // -  or, 'L' has an implicit capture.
  // AND
  //   -- there is no enclosing closure
  //   -- or, there is some enclosing closure 'E' that has already captured the
  //      *enclosing object*, and every intervening closure (if any) between 'E'
  //      and 'L' can implicitly capture the *enclosing object*.
  //   -- or, every enclosing closure can implicitly capture the
  //      *enclosing object*


  unsigned NumCapturingClosures = 0;
  for (unsigned idx = MaxFunctionScopesIndex; idx != 0; idx--) {
    if (CapturingScopeInfo *CSI =
            dyn_cast<CapturingScopeInfo>(FunctionScopes[idx])) {
      if (CSI->CXXThisCaptureIndex != 0) {
        // 'this' is already being captured; there isn't anything more to do.
        break;
      }
      LambdaScopeInfo *LSI = dyn_cast<LambdaScopeInfo>(CSI);
      if (LSI && isGenericLambdaCallOperatorSpecialization(LSI->CallOperator)) {
        // This context can't implicitly capture 'this'; fail out.
        if (BuildAndDiagnose)
          Diag(Loc, diag::err_this_capture)
              << (Explicit && idx == MaxFunctionScopesIndex);
        return true;
      }
      if (CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_LambdaByref ||
          CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_LambdaByval ||
          CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_Block ||
          CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_CapturedRegion ||
          (Explicit && idx == MaxFunctionScopesIndex)) {
        // Regarding (Explicit && idx == MaxFunctionScopesIndex): only the first
        // iteration through can be an explicit capture, all enclosing closures,
        // if any, must perform implicit captures.

        // This closure can capture 'this'; continue looking upwards.
        NumCapturingClosures++;
        continue;
      }
      // This context can't implicitly capture 'this'; fail out.
      if (BuildAndDiagnose)
        Diag(Loc, diag::err_this_capture)
            << (Explicit && idx == MaxFunctionScopesIndex);
      return true;
    }
    break;
  }
  if (!BuildAndDiagnose) return false;

  // If we got here, then the closure at MaxFunctionScopesIndex on the
  // FunctionScopes stack, can capture the *enclosing object*, so capture it
  // (including implicit by-reference captures in any enclosing closures).

  // In the loop below, respect the ByCopy flag only for the closure requesting
  // the capture (i.e. first iteration through the loop below).  Ignore it for
  // all enclosing closure's upto NumCapturingClosures (since they must be
  // implicitly capturing the *enclosing  object* by reference (see loop
  // above)).
  assert((!ByCopy ||
          dyn_cast<LambdaScopeInfo>(FunctionScopes[MaxFunctionScopesIndex])) &&
         "Only a lambda can capture the enclosing object (referred to by "
         "*this) by copy");
  // FIXME: We need to delay this marking in PotentiallyPotentiallyEvaluated
  // contexts.
  QualType ThisTy = getCurrentThisType();
  for (unsigned idx = MaxFunctionScopesIndex; NumCapturingClosures;
      --idx, --NumCapturingClosures) {
    CapturingScopeInfo *CSI = cast<CapturingScopeInfo>(FunctionScopes[idx]);
    Expr *ThisExpr = nullptr;

    if (LambdaScopeInfo *LSI = dyn_cast<LambdaScopeInfo>(CSI)) {
      // For lambda expressions, build a field and an initializing expression,
      // and capture the *enclosing object* by copy only if this is the first
      // iteration.
      ThisExpr = captureThis(*this, Context, LSI->Lambda, ThisTy, Loc,
                             ByCopy && idx == MaxFunctionScopesIndex);

    } else if (CapturedRegionScopeInfo *RSI
        = dyn_cast<CapturedRegionScopeInfo>(FunctionScopes[idx]))
      ThisExpr =
          captureThis(*this, Context, RSI->TheRecordDecl, ThisTy, Loc,
                      false/*ByCopy*/);

    bool isNested = NumCapturingClosures > 1;
    CSI->addThisCapture(isNested, Loc, ThisExpr, ByCopy);
  }
  return false;
}

ExprResult Sema::ActOnCXXThis(SourceLocation Loc) {
  /// C++ 9.3.2: In the body of a non-static member function, the keyword this
  /// is a non-lvalue expression whose value is the address of the object for
  /// which the function is called.

  QualType ThisTy = getCurrentThisType();
  if (ThisTy.isNull()) return Diag(Loc, diag::err_invalid_this_use);

  CheckCXXThisCapture(Loc);
  return new (Context) CXXThisExpr(Loc, ThisTy, /*isImplicit=*/false);
}

bool Sema::isThisOutsideMemberFunctionBody(QualType BaseType) {
  // If we're outside the body of a member function, then we'll have a specified
  // type for 'this'.
  if (CXXThisTypeOverride.isNull())
    return false;

  // Determine whether we're looking into a class that's currently being
  // defined.
  CXXRecordDecl *Class = BaseType->getAsCXXRecordDecl();
  return Class && Class->isBeingDefined();
}

ExprResult
Sema::ActOnCXXTypeConstructExpr(ParsedType TypeRep,
                                SourceLocation LParenLoc,
                                MultiExprArg exprs,
                                SourceLocation RParenLoc) {
  if (!TypeRep)
    return ExprError();

  TypeSourceInfo *TInfo;
  QualType Ty = GetTypeFromParser(TypeRep, &TInfo);
  if (!TInfo)
    TInfo = Context.getTrivialTypeSourceInfo(Ty, SourceLocation());

  auto Result = BuildCXXTypeConstructExpr(TInfo, LParenLoc, exprs, RParenLoc);
  // Avoid creating a non-type-dependent expression that contains typos.
  // Non-type-dependent expressions are liable to be discarded without
  // checking for embedded typos.
  if (!Result.isInvalid() && Result.get()->isInstantiationDependent() &&
      !Result.get()->isTypeDependent())
    Result = CorrectDelayedTyposInExpr(Result.get());
  return Result;
}

/// ActOnCXXTypeConstructExpr - Parse construction of a specified type.
/// Can be interpreted either as function-style casting ("int(x)")
/// or class type construction ("ClassType(x,y,z)")
/// or creation of a value-initialized type ("int()").
ExprResult
Sema::BuildCXXTypeConstructExpr(TypeSourceInfo *TInfo,
                                SourceLocation LParenLoc,
                                MultiExprArg Exprs,
                                SourceLocation RParenLoc) {
  QualType Ty = TInfo->getType();
  SourceLocation TyBeginLoc = TInfo->getTypeLoc().getBeginLoc();

  if (Ty->isDependentType() || CallExpr::hasAnyTypeDependentArguments(Exprs)) {
    return CXXUnresolvedConstructExpr::Create(Context, TInfo, LParenLoc, Exprs,
                                              RParenLoc);
  }

  bool ListInitialization = LParenLoc.isInvalid();
  assert((!ListInitialization || (Exprs.size() == 1 && isa<InitListExpr>(Exprs[0])))
         && "List initialization must have initializer list as expression.");
  SourceRange FullRange = SourceRange(TyBeginLoc,
      ListInitialization ? Exprs[0]->getSourceRange().getEnd() : RParenLoc);

  // C++ [expr.type.conv]p1:
  // If the expression list is a single expression, the type conversion
  // expression is equivalent (in definedness, and if defined in meaning) to the
  // corresponding cast expression.
  if (Exprs.size() == 1 && !ListInitialization) {
    Expr *Arg = Exprs[0];
    return BuildCXXFunctionalCastExpr(TInfo, LParenLoc, Arg, RParenLoc);
  }

  // C++14 [expr.type.conv]p2: The expression T(), where T is a
  //   simple-type-specifier or typename-specifier for a non-array complete
  //   object type or the (possibly cv-qualified) void type, creates a prvalue
  //   of the specified type, whose value is that produced by value-initializing
  //   an object of type T.
  QualType ElemTy = Ty;
  if (Ty->isArrayType()) {
    if (!ListInitialization)
      return ExprError(Diag(TyBeginLoc,
                            diag::err_value_init_for_array_type) << FullRange);
    ElemTy = Context.getBaseElementType(Ty);
  }

  if (!ListInitialization && Ty->isFunctionType())
    return ExprError(Diag(TyBeginLoc, diag::err_value_init_for_function_type)
                     << FullRange);

  if (!Ty->isVoidType() &&
      RequireCompleteType(TyBeginLoc, ElemTy,
                          diag::err_invalid_incomplete_type_use, FullRange))
    return ExprError();

  if (RequireNonAbstractType(TyBeginLoc, Ty,
                             diag::err_allocation_of_abstract_type))
    return ExprError();

  InitializedEntity Entity = InitializedEntity::InitializeTemporary(TInfo);
  InitializationKind Kind =
      Exprs.size() ? ListInitialization
      ? InitializationKind::CreateDirectList(TyBeginLoc)
      : InitializationKind::CreateDirect(TyBeginLoc, LParenLoc, RParenLoc)
      : InitializationKind::CreateValue(TyBeginLoc, LParenLoc, RParenLoc);
  InitializationSequence InitSeq(*this, Entity, Kind, Exprs);
  ExprResult Result = InitSeq.Perform(*this, Entity, Kind, Exprs);

  if (Result.isInvalid() || !ListInitialization)
    return Result;

  Expr *Inner = Result.get();
  if (CXXBindTemporaryExpr *BTE = dyn_cast_or_null<CXXBindTemporaryExpr>(Inner))
    Inner = BTE->getSubExpr();
  if (!isa<CXXTemporaryObjectExpr>(Inner)) {
    // If we created a CXXTemporaryObjectExpr, that node also represents the
    // functional cast. Otherwise, create an explicit cast to represent
    // the syntactic form of a functional-style cast that was used here.
    //
    // FIXME: Creating a CXXFunctionalCastExpr around a CXXConstructExpr
    // would give a more consistent AST representation than using a
    // CXXTemporaryObjectExpr. It's also weird that the functional cast
    // is sometimes handled by initialization and sometimes not.
    QualType ResultType = Result.get()->getType();
    Result = CXXFunctionalCastExpr::Create(
        Context, ResultType, Expr::getValueKindForType(TInfo->getType()), TInfo,
        CK_NoOp, Result.get(), /*Path=*/nullptr, LParenLoc, RParenLoc);
  }

  return Result;
}

/// doesUsualArrayDeleteWantSize - Answers whether the usual
/// operator delete[] for the given type has a size_t parameter.
static bool doesUsualArrayDeleteWantSize(Sema &S, SourceLocation loc,
                                         QualType allocType) {
  const RecordType *record =
    allocType->getBaseElementTypeUnsafe()->getAs<RecordType>();
  if (!record) return false;

  // Try to find an operator delete[] in class scope.

  DeclarationName deleteName =
    S.Context.DeclarationNames.getCXXOperatorName(OO_Array_Delete);
  LookupResult ops(S, deleteName, loc, Sema::LookupOrdinaryName);
  S.LookupQualifiedName(ops, record->getDecl());

  // We're just doing this for information.
  ops.suppressDiagnostics();

  // Very likely: there's no operator delete[].
  if (ops.empty()) return false;

  // If it's ambiguous, it should be illegal to call operator delete[]
  // on this thing, so it doesn't matter if we allocate extra space or not.
  if (ops.isAmbiguous()) return false;

  LookupResult::Filter filter = ops.makeFilter();
  while (filter.hasNext()) {
    NamedDecl *del = filter.next()->getUnderlyingDecl();

    // C++0x [basic.stc.dynamic.deallocation]p2:
    //   A template instance is never a usual deallocation function,
    //   regardless of its signature.
    if (isa<FunctionTemplateDecl>(del)) {
      filter.erase();
      continue;
    }

    // C++0x [basic.stc.dynamic.deallocation]p2:
    //   If class T does not declare [an operator delete[] with one
    //   parameter] but does declare a member deallocation function
    //   named operator delete[] with exactly two parameters, the
    //   second of which has type std::size_t, then this function
    //   is a usual deallocation function.
    if (!cast<CXXMethodDecl>(del)->isUsualDeallocationFunction()) {
      filter.erase();
      continue;
    }
  }
  filter.done();

  if (!ops.isSingleResult()) return false;

  const FunctionDecl *del = cast<FunctionDecl>(ops.getFoundDecl());
  return (del->getNumParams() == 2);
}

/// \brief Parsed a C++ 'new' expression (C++ 5.3.4).
///
/// E.g.:
/// @code new (memory) int[size][4] @endcode
/// or
/// @code ::new Foo(23, "hello") @endcode
///
/// \param StartLoc The first location of the expression.
/// \param UseGlobal True if 'new' was prefixed with '::'.
/// \param PlacementLParen Opening paren of the placement arguments.
/// \param PlacementArgs Placement new arguments.
/// \param PlacementRParen Closing paren of the placement arguments.
/// \param TypeIdParens If the type is in parens, the source range.
/// \param D The type to be allocated, as well as array dimensions.
/// \param Initializer The initializing expression or initializer-list, or null
///   if there is none.
ExprResult
Sema::ActOnCXXNew(SourceLocation StartLoc, bool UseGlobal,
                  SourceLocation PlacementLParen, MultiExprArg PlacementArgs,
                  SourceLocation PlacementRParen, SourceRange TypeIdParens,
                  Declarator &D, Expr *Initializer) {
  bool TypeContainsAuto = D.getDeclSpec().containsPlaceholderType();

  Expr *ArraySize = nullptr;
  // If the specified type is an array, unwrap it and save the expression.
  if (D.getNumTypeObjects() > 0 &&
      D.getTypeObject(0).Kind == DeclaratorChunk::Array) {
     DeclaratorChunk &Chunk = D.getTypeObject(0);
    if (TypeContainsAuto)
      return ExprError(Diag(Chunk.Loc, diag::err_new_array_of_auto)
        << D.getSourceRange());
    if (Chunk.Arr.hasStatic)
      return ExprError(Diag(Chunk.Loc, diag::err_static_illegal_in_new)
        << D.getSourceRange());
    if (!Chunk.Arr.NumElts)
      return ExprError(Diag(Chunk.Loc, diag::err_array_new_needs_size)
        << D.getSourceRange());

    ArraySize = static_cast<Expr*>(Chunk.Arr.NumElts);
    D.DropFirstTypeObject();
  }

  // Every dimension shall be of constant size.
  if (ArraySize) {
    for (unsigned I = 0, N = D.getNumTypeObjects(); I < N; ++I) {
      if (D.getTypeObject(I).Kind != DeclaratorChunk::Array)
        break;

      DeclaratorChunk::ArrayTypeInfo &Array = D.getTypeObject(I).Arr;
      if (Expr *NumElts = (Expr *)Array.NumElts) {
        if (!NumElts->isTypeDependent() && !NumElts->isValueDependent()) {
          if (getLangOpts().CPlusPlus14) {
	    // C++1y [expr.new]p6: Every constant-expression in a noptr-new-declarator
	    //   shall be a converted constant expression (5.19) of type std::size_t
	    //   and shall evaluate to a strictly positive value.
            unsigned IntWidth = Context.getTargetInfo().getIntWidth();
            assert(IntWidth && "Builtin type of size 0?");
            llvm::APSInt Value(IntWidth);
            Array.NumElts
             = CheckConvertedConstantExpression(NumElts, Context.getSizeType(), Value,
                                                CCEK_NewExpr)
                 .get();
          } else {
            Array.NumElts
              = VerifyIntegerConstantExpression(NumElts, nullptr,
                                                diag::err_new_array_nonconst)
                  .get();
          }
          if (!Array.NumElts)
            return ExprError();
        }
      }
    }
  }

  TypeSourceInfo *TInfo = GetTypeForDeclarator(D, /*Scope=*/nullptr);
  QualType AllocType = TInfo->getType();
  if (D.isInvalidType())
    return ExprError();

  SourceRange DirectInitRange;
  if (ParenListExpr *List = dyn_cast_or_null<ParenListExpr>(Initializer))
    DirectInitRange = List->getSourceRange();

  return BuildCXXNew(SourceRange(StartLoc, D.getLocEnd()), UseGlobal,
                     PlacementLParen,
                     PlacementArgs,
                     PlacementRParen,
                     TypeIdParens,
                     AllocType,
                     TInfo,
                     ArraySize,
                     DirectInitRange,
                     Initializer,
                     TypeContainsAuto);
}

static bool isLegalArrayNewInitializer(CXXNewExpr::InitializationStyle Style,
                                       Expr *Init) {
  if (!Init)
    return true;
  if (ParenListExpr *PLE = dyn_cast<ParenListExpr>(Init))
    return PLE->getNumExprs() == 0;
  if (isa<ImplicitValueInitExpr>(Init))
    return true;
  else if (CXXConstructExpr *CCE = dyn_cast<CXXConstructExpr>(Init))
    return !CCE->isListInitialization() &&
           CCE->getConstructor()->isDefaultConstructor();
  else if (Style == CXXNewExpr::ListInit) {
    assert(isa<InitListExpr>(Init) &&
           "Shouldn't create list CXXConstructExprs for arrays.");
    return true;
  }
  return false;
}

ExprResult
Sema::BuildCXXNew(SourceRange Range, bool UseGlobal,
                  SourceLocation PlacementLParen,
                  MultiExprArg PlacementArgs,
                  SourceLocation PlacementRParen,
                  SourceRange TypeIdParens,
                  QualType AllocType,
                  TypeSourceInfo *AllocTypeInfo,
                  Expr *ArraySize,
                  SourceRange DirectInitRange,
                  Expr *Initializer,
                  bool TypeMayContainAuto) {
  SourceRange TypeRange = AllocTypeInfo->getTypeLoc().getSourceRange();
  SourceLocation StartLoc = Range.getBegin();

  CXXNewExpr::InitializationStyle initStyle;
  if (DirectInitRange.isValid()) {
    assert(Initializer && "Have parens but no initializer.");
    initStyle = CXXNewExpr::CallInit;
  } else if (Initializer && isa<InitListExpr>(Initializer))
    initStyle = CXXNewExpr::ListInit;
  else {
    assert((!Initializer || isa<ImplicitValueInitExpr>(Initializer) ||
            isa<CXXConstructExpr>(Initializer)) &&
           "Initializer expression that cannot have been implicitly created.");
    initStyle = CXXNewExpr::NoInit;
  }

  Expr **Inits = &Initializer;
  unsigned NumInits = Initializer ? 1 : 0;
  if (ParenListExpr *List = dyn_cast_or_null<ParenListExpr>(Initializer)) {
    assert(initStyle == CXXNewExpr::CallInit && "paren init for non-call init");
    Inits = List->getExprs();
    NumInits = List->getNumExprs();
  }

  // C++11 [dcl.spec.auto]p6. Deduce the type which 'auto' stands in for.
  if (TypeMayContainAuto && AllocType->isUndeducedType()) {
    if (initStyle == CXXNewExpr::NoInit || NumInits == 0)
      return ExprError(Diag(StartLoc, diag::err_auto_new_requires_ctor_arg)
                       << AllocType << TypeRange);
    if (initStyle == CXXNewExpr::ListInit ||
        (NumInits == 1 && isa<InitListExpr>(Inits[0])))
      return ExprError(Diag(Inits[0]->getLocStart(),
                            diag::err_auto_new_list_init)
                       << AllocType << TypeRange);
    if (NumInits > 1) {
      Expr *FirstBad = Inits[1];
      return ExprError(Diag(FirstBad->getLocStart(),
                            diag::err_auto_new_ctor_multiple_expressions)
                       << AllocType << TypeRange);
    }
    Expr *Deduce = Inits[0];
    QualType DeducedType;
    if (DeduceAutoType(AllocTypeInfo, Deduce, DeducedType) == DAR_Failed)
      return ExprError(Diag(StartLoc, diag::err_auto_new_deduction_failure)
                       << AllocType << Deduce->getType()
                       << TypeRange << Deduce->getSourceRange());
    if (DeducedType.isNull())
      return ExprError();
    AllocType = DeducedType;
  }

  // Per C++0x [expr.new]p5, the type being constructed may be a
  // typedef of an array type.
  if (!ArraySize) {
    if (const ConstantArrayType *Array
                              = Context.getAsConstantArrayType(AllocType)) {
      ArraySize = IntegerLiteral::Create(Context, Array->getSize(),
                                         Context.getSizeType(),
                                         TypeRange.getEnd());
      AllocType = Array->getElementType();
    }
  }

  if (CheckAllocatedType(AllocType, TypeRange.getBegin(), TypeRange))
    return ExprError();

  if (initStyle == CXXNewExpr::ListInit &&
      isStdInitializerList(AllocType, nullptr)) {
    Diag(AllocTypeInfo->getTypeLoc().getBeginLoc(),
         diag::warn_dangling_std_initializer_list)
        << /*at end of FE*/0 << Inits[0]->getSourceRange();
  }

  // In ARC, infer 'retaining' for the allocated
  if (getLangOpts().ObjCAutoRefCount &&
      AllocType.getObjCLifetime() == Qualifiers::OCL_None &&
      AllocType->isObjCLifetimeType()) {
    AllocType = Context.getLifetimeQualifiedType(AllocType,
                                    AllocType->getObjCARCImplicitLifetime());
  }

  QualType ResultType = Context.getPointerType(AllocType);

  if (ArraySize && ArraySize->getType()->isNonOverloadPlaceholderType()) {
    ExprResult result = CheckPlaceholderExpr(ArraySize);
    if (result.isInvalid()) return ExprError();
    ArraySize = result.get();
  }
  // C++98 5.3.4p6: "The expression in a direct-new-declarator shall have
  //   integral or enumeration type with a non-negative value."
  // C++11 [expr.new]p6: The expression [...] shall be of integral or unscoped
  //   enumeration type, or a class type for which a single non-explicit
  //   conversion function to integral or unscoped enumeration type exists.
  // C++1y [expr.new]p6: The expression [...] is implicitly converted to
  //   std::size_t.
  if (ArraySize && !ArraySize->isTypeDependent()) {
    ExprResult ConvertedSize;
    if (getLangOpts().CPlusPlus14) {
      assert(Context.getTargetInfo().getIntWidth() && "Builtin type of size 0?");

      ConvertedSize = PerformImplicitConversion(ArraySize, Context.getSizeType(),
						AA_Converting);

      if (!ConvertedSize.isInvalid() &&
          ArraySize->getType()->getAs<RecordType>())
        // Diagnose the compatibility of this conversion.
        Diag(StartLoc, diag::warn_cxx98_compat_array_size_conversion)
          << ArraySize->getType() << 0 << "'size_t'";
    } else {
      class SizeConvertDiagnoser : public ICEConvertDiagnoser {
      protected:
        Expr *ArraySize;

      public:
        SizeConvertDiagnoser(Expr *ArraySize)
            : ICEConvertDiagnoser(/*AllowScopedEnumerations*/false, false, false),
              ArraySize(ArraySize) {}

        SemaDiagnosticBuilder diagnoseNotInt(Sema &S, SourceLocation Loc,
                                             QualType T) override {
          return S.Diag(Loc, diag::err_array_size_not_integral)
                   << S.getLangOpts().CPlusPlus11 << T;
        }

        SemaDiagnosticBuilder diagnoseIncomplete(
            Sema &S, SourceLocation Loc, QualType T) override {
          return S.Diag(Loc, diag::err_array_size_incomplete_type)
                   << T << ArraySize->getSourceRange();
        }

        SemaDiagnosticBuilder diagnoseExplicitConv(
            Sema &S, SourceLocation Loc, QualType T, QualType ConvTy) override {
          return S.Diag(Loc, diag::err_array_size_explicit_conversion) << T << ConvTy;
        }

        SemaDiagnosticBuilder noteExplicitConv(
            Sema &S, CXXConversionDecl *Conv, QualType ConvTy) override {
          return S.Diag(Conv->getLocation(), diag::note_array_size_conversion)
                   << ConvTy->isEnumeralType() << ConvTy;
        }

        SemaDiagnosticBuilder diagnoseAmbiguous(
            Sema &S, SourceLocation Loc, QualType T) override {
          return S.Diag(Loc, diag::err_array_size_ambiguous_conversion) << T;
        }

        SemaDiagnosticBuilder noteAmbiguous(
            Sema &S, CXXConversionDecl *Conv, QualType ConvTy) override {
          return S.Diag(Conv->getLocation(), diag::note_array_size_conversion)
                   << ConvTy->isEnumeralType() << ConvTy;
        }

        SemaDiagnosticBuilder diagnoseConversion(Sema &S, SourceLocation Loc,
                                                 QualType T,
                                                 QualType ConvTy) override {
          return S.Diag(Loc,
                        S.getLangOpts().CPlusPlus11
                          ? diag::warn_cxx98_compat_array_size_conversion
                          : diag::ext_array_size_conversion)
                   << T << ConvTy->isEnumeralType() << ConvTy;
        }
      } SizeDiagnoser(ArraySize);

      ConvertedSize = PerformContextualImplicitConversion(StartLoc, ArraySize,
                                                          SizeDiagnoser);
    }
    if (ConvertedSize.isInvalid())
      return ExprError();

    ArraySize = ConvertedSize.get();
    QualType SizeType = ArraySize->getType();

    if (!SizeType->isIntegralOrUnscopedEnumerationType())
      return ExprError();

    // C++98 [expr.new]p7:
    //   The expression in a direct-new-declarator shall have integral type
    //   with a non-negative value.
    //
    // Let's see if this is a constant < 0. If so, we reject it out of
    // hand. Otherwise, if it's not a constant, we must have an unparenthesized
    // array type.
    //
    // Note: such a construct has well-defined semantics in C++11: it throws
    // std::bad_array_new_length.
    if (!ArraySize->isValueDependent()) {
      llvm::APSInt Value;
      // We've already performed any required implicit conversion to integer or
      // unscoped enumeration type.
      if (ArraySize->isIntegerConstantExpr(Value, Context)) {
        if (Value < llvm::APSInt(
                        llvm::APInt::getNullValue(Value.getBitWidth()),
                                 Value.isUnsigned())) {
          if (getLangOpts().CPlusPlus11)
            Diag(ArraySize->getLocStart(),
                 diag::warn_typecheck_negative_array_new_size)
              << ArraySize->getSourceRange();
          else
            return ExprError(Diag(ArraySize->getLocStart(),
                                  diag::err_typecheck_negative_array_size)
                             << ArraySize->getSourceRange());
        } else if (!AllocType->isDependentType()) {
          unsigned ActiveSizeBits =
            ConstantArrayType::getNumAddressingBits(Context, AllocType, Value);
          if (ActiveSizeBits > ConstantArrayType::getMaxSizeBits(Context)) {
            if (getLangOpts().CPlusPlus11)
              Diag(ArraySize->getLocStart(),
                   diag::warn_array_new_too_large)
                << Value.toString(10)
                << ArraySize->getSourceRange();
            else
              return ExprError(Diag(ArraySize->getLocStart(),
                                    diag::err_array_too_large)
                               << Value.toString(10)
                               << ArraySize->getSourceRange());
          }
        }
      } else if (TypeIdParens.isValid()) {
        // Can't have dynamic array size when the type-id is in parentheses.
        Diag(ArraySize->getLocStart(), diag::ext_new_paren_array_nonconst)
          << ArraySize->getSourceRange()
          << FixItHint::CreateRemoval(TypeIdParens.getBegin())
          << FixItHint::CreateRemoval(TypeIdParens.getEnd());

        TypeIdParens = SourceRange();
      }
    }

    // Note that we do *not* convert the argument in any way.  It can
    // be signed, larger than size_t, whatever.
  }

  FunctionDecl *OperatorNew = nullptr;
  FunctionDecl *OperatorDelete = nullptr;

  if (!AllocType->isDependentType() &&
      !Expr::hasAnyTypeDependentArguments(PlacementArgs) &&
      FindAllocationFunctions(StartLoc,
                              SourceRange(PlacementLParen, PlacementRParen),
                              UseGlobal, AllocType, ArraySize, PlacementArgs,
                              OperatorNew, OperatorDelete))
    return ExprError();

  // If this is an array allocation, compute whether the usual array
  // deallocation function for the type has a size_t parameter.
  bool UsualArrayDeleteWantsSize = false;
  if (ArraySize && !AllocType->isDependentType())
    UsualArrayDeleteWantsSize
      = doesUsualArrayDeleteWantSize(*this, StartLoc, AllocType);

  SmallVector<Expr *, 8> AllPlaceArgs;
  if (OperatorNew) {
    const FunctionProtoType *Proto =
        OperatorNew->getType()->getAs<FunctionProtoType>();
    VariadicCallType CallType = Proto->isVariadic() ? VariadicFunction
                                                    : VariadicDoesNotApply;

    // We've already converted the placement args, just fill in any default
    // arguments. Skip the first parameter because we don't have a corresponding
    // argument.
    if (GatherArgumentsForCall(PlacementLParen, OperatorNew, Proto, 1,
                               PlacementArgs, AllPlaceArgs, CallType))
      return ExprError();

    if (!AllPlaceArgs.empty())
      PlacementArgs = AllPlaceArgs;

    // FIXME: This is wrong: PlacementArgs misses out the first (size) argument.
    DiagnoseSentinelCalls(OperatorNew, PlacementLParen, PlacementArgs);

    // FIXME: Missing call to CheckFunctionCall or equivalent
  }

  // Warn if the type is over-aligned and is being allocated by global operator
  // new.
  if (PlacementArgs.empty() && OperatorNew &&
      (OperatorNew->isImplicit() ||
       (OperatorNew->getLocStart().isValid() &&
        getSourceManager().isInSystemHeader(OperatorNew->getLocStart())))) {
    if (unsigned Align = Context.getPreferredTypeAlign(AllocType.getTypePtr())){
      unsigned SuitableAlign = Context.getTargetInfo().getSuitableAlign();
      if (Align > SuitableAlign)
        Diag(StartLoc, diag::warn_overaligned_type)
            << AllocType
            << unsigned(Align / Context.getCharWidth())
            << unsigned(SuitableAlign / Context.getCharWidth());
    }
  }

  QualType InitType = AllocType;
  // Array 'new' can't have any initializers except empty parentheses.
  // Initializer lists are also allowed, in C++11. Rely on the parser for the
  // dialect distinction.
  if (ResultType->isArrayType() || ArraySize) {
    if (!isLegalArrayNewInitializer(initStyle, Initializer)) {
      SourceRange InitRange(Inits[0]->getLocStart(),
                            Inits[NumInits - 1]->getLocEnd());
      Diag(StartLoc, diag::err_new_array_init_args) << InitRange;
      return ExprError();
    }
    if (InitListExpr *ILE = dyn_cast_or_null<InitListExpr>(Initializer)) {
      // We do the initialization typechecking against the array type
      // corresponding to the number of initializers + 1 (to also check
      // default-initialization).
      unsigned NumElements = ILE->getNumInits() + 1;
      InitType = Context.getConstantArrayType(AllocType,
          llvm::APInt(Context.getTypeSize(Context.getSizeType()), NumElements),
                                              ArrayType::Normal, 0);
    }
  }

  // If we can perform the initialization, and we've not already done so,
  // do it now.
  if (!AllocType->isDependentType() &&
      !Expr::hasAnyTypeDependentArguments(
          llvm::makeArrayRef(Inits, NumInits))) {
    // C++11 [expr.new]p15:
    //   A new-expression that creates an object of type T initializes that
    //   object as follows:
    InitializationKind Kind
    //     - If the new-initializer is omitted, the object is default-
    //       initialized (8.5); if no initialization is performed,
    //       the object has indeterminate value
      = initStyle == CXXNewExpr::NoInit
          ? InitializationKind::CreateDefault(TypeRange.getBegin())
    //     - Otherwise, the new-initializer is interpreted according to the
    //       initialization rules of 8.5 for direct-initialization.
          : initStyle == CXXNewExpr::ListInit
              ? InitializationKind::CreateDirectList(TypeRange.getBegin())
              : InitializationKind::CreateDirect(TypeRange.getBegin(),
                                                 DirectInitRange.getBegin(),
                                                 DirectInitRange.getEnd());

    InitializedEntity Entity
      = InitializedEntity::InitializeNew(StartLoc, InitType);
    InitializationSequence InitSeq(*this, Entity, Kind, MultiExprArg(Inits, NumInits));
    ExprResult FullInit = InitSeq.Perform(*this, Entity, Kind,
                                          MultiExprArg(Inits, NumInits));
    if (FullInit.isInvalid())
      return ExprError();

    // FullInit is our initializer; strip off CXXBindTemporaryExprs, because
    // we don't want the initialized object to be destructed.
    if (CXXBindTemporaryExpr *Binder =
            dyn_cast_or_null<CXXBindTemporaryExpr>(FullInit.get()))
      FullInit = Binder->getSubExpr();

    Initializer = FullInit.get();
  }

  // Mark the new and delete operators as referenced.
  if (OperatorNew) {
    if (DiagnoseUseOfDecl(OperatorNew, StartLoc))
      return ExprError();
    MarkFunctionReferenced(StartLoc, OperatorNew);
  }
  if (OperatorDelete) {
    if (DiagnoseUseOfDecl(OperatorDelete, StartLoc))
      return ExprError();
    MarkFunctionReferenced(StartLoc, OperatorDelete);
  }

  // C++0x [expr.new]p17:
  //   If the new expression creates an array of objects of class type,
  //   access and ambiguity control are done for the destructor.
  QualType BaseAllocType = Context.getBaseElementType(AllocType);
  if (ArraySize && !BaseAllocType->isDependentType()) {
    if (const RecordType *BaseRecordType = BaseAllocType->getAs<RecordType>()) {
      if (CXXDestructorDecl *dtor = LookupDestructor(
              cast<CXXRecordDecl>(BaseRecordType->getDecl()))) {
        MarkFunctionReferenced(StartLoc, dtor);
        CheckDestructorAccess(StartLoc, dtor,
                              PDiag(diag::err_access_dtor)
                                << BaseAllocType);
        if (DiagnoseUseOfDecl(dtor, StartLoc))
          return ExprError();
      }
    }
  }

  return new (Context)
      CXXNewExpr(Context, UseGlobal, OperatorNew, OperatorDelete,
                 UsualArrayDeleteWantsSize, PlacementArgs, TypeIdParens,
                 ArraySize, initStyle, Initializer, ResultType, AllocTypeInfo,
                 Range, DirectInitRange);
}

/// \brief Checks that a type is suitable as the allocated type
/// in a new-expression.
bool Sema::CheckAllocatedType(QualType AllocType, SourceLocation Loc,
                              SourceRange R) {
  // C++ 5.3.4p1: "[The] type shall be a complete object type, but not an
  //   abstract class type or array thereof.
  if (AllocType->isFunctionType())
    return Diag(Loc, diag::err_bad_new_type)
      << AllocType << 0 << R;
  else if (AllocType->isReferenceType())
    return Diag(Loc, diag::err_bad_new_type)
      << AllocType << 1 << R;
  else if (!AllocType->isDependentType() &&
           RequireCompleteType(Loc, AllocType, diag::err_new_incomplete_type,R))
    return true;
  else if (RequireNonAbstractType(Loc, AllocType,
                                  diag::err_allocation_of_abstract_type))
    return true;
  else if (AllocType->isVariablyModifiedType())
    return Diag(Loc, diag::err_variably_modified_new_type)
             << AllocType;
  else if (unsigned AddressSpace = AllocType.getAddressSpace())
    return Diag(Loc, diag::err_address_space_qualified_new)
      << AllocType.getUnqualifiedType() << AddressSpace;
  else if (getLangOpts().ObjCAutoRefCount) {
    if (const ArrayType *AT = Context.getAsArrayType(AllocType)) {
      QualType BaseAllocType = Context.getBaseElementType(AT);
      if (BaseAllocType.getObjCLifetime() == Qualifiers::OCL_None &&
          BaseAllocType->isObjCLifetimeType())
        return Diag(Loc, diag::err_arc_new_array_without_ownership)
          << BaseAllocType;
    }
  }

  return false;
}

/// \brief Determine whether the given function is a non-placement
/// deallocation function.
static bool isNonPlacementDeallocationFunction(Sema &S, FunctionDecl *FD) {
  if (FD->isInvalidDecl())
    return false;

  if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FD))
    return Method->isUsualDeallocationFunction();

  if (FD->getOverloadedOperator() != OO_Delete &&
      FD->getOverloadedOperator() != OO_Array_Delete)
    return false;

  if (FD->getNumParams() == 1)
    return true;

  return S.getLangOpts().SizedDeallocation && FD->getNumParams() == 2 &&
         S.Context.hasSameUnqualifiedType(FD->getParamDecl(1)->getType(),
                                          S.Context.getSizeType());
}

/// FindAllocationFunctions - Finds the overloads of operator new and delete
/// that are appropriate for the allocation.
bool Sema::FindAllocationFunctions(SourceLocation StartLoc, SourceRange Range,
                                   bool UseGlobal, QualType AllocType,
                                   bool IsArray, MultiExprArg PlaceArgs,
                                   FunctionDecl *&OperatorNew,
                                   FunctionDecl *&OperatorDelete) {
  // --- Choosing an allocation function ---
  // C++ 5.3.4p8 - 14 & 18
  // 1) If UseGlobal is true, only look in the global scope. Else, also look
  //   in the scope of the allocated class.
  // 2) If an array size is given, look for operator new[], else look for
  //   operator new.
  // 3) The first argument is always size_t. Append the arguments from the
  //   placement form.

  SmallVector<Expr*, 8> AllocArgs(1 + PlaceArgs.size());
  // We don't care about the actual value of this argument.
  // FIXME: Should the Sema create the expression and embed it in the syntax
  // tree? Or should the consumer just recalculate the value?
  IntegerLiteral Size(Context, llvm::APInt::getNullValue(
                      Context.getTargetInfo().getPointerWidth(0)),
                      Context.getSizeType(),
                      SourceLocation());
  AllocArgs[0] = &Size;
  std::copy(PlaceArgs.begin(), PlaceArgs.end(), AllocArgs.begin() + 1);

  // C++ [expr.new]p8:
  //   If the allocated type is a non-array type, the allocation
  //   function's name is operator new and the deallocation function's
  //   name is operator delete. If the allocated type is an array
  //   type, the allocation function's name is operator new[] and the
  //   deallocation function's name is operator delete[].
  DeclarationName NewName = Context.DeclarationNames.getCXXOperatorName(
                                        IsArray ? OO_Array_New : OO_New);
  DeclarationName DeleteName = Context.DeclarationNames.getCXXOperatorName(
                                        IsArray ? OO_Array_Delete : OO_Delete);

  QualType AllocElemType = Context.getBaseElementType(AllocType);

  if (AllocElemType->isRecordType() && !UseGlobal) {
    CXXRecordDecl *Record
      = cast<CXXRecordDecl>(AllocElemType->getAs<RecordType>()->getDecl());
    if (FindAllocationOverload(StartLoc, Range, NewName, AllocArgs, Record,
                               /*AllowMissing=*/true, OperatorNew))
      return true;
  }

  if (!OperatorNew) {
    // Didn't find a member overload. Look for a global one.
    DeclareGlobalNewDelete();
    DeclContext *TUDecl = Context.getTranslationUnitDecl();
    bool FallbackEnabled = IsArray && Context.getLangOpts().MSVCCompat;
    if (FindAllocationOverload(StartLoc, Range, NewName, AllocArgs, TUDecl,
                               /*AllowMissing=*/FallbackEnabled, OperatorNew,
                               /*Diagnose=*/!FallbackEnabled)) {
      if (!FallbackEnabled)
        return true;

      // MSVC will fall back on trying to find a matching global operator new
      // if operator new[] cannot be found.  Also, MSVC will leak by not
      // generating a call to operator delete or operator delete[], but we
      // will not replicate that bug.
      NewName = Context.DeclarationNames.getCXXOperatorName(OO_New);
      DeleteName = Context.DeclarationNames.getCXXOperatorName(OO_Delete);
      if (FindAllocationOverload(StartLoc, Range, NewName, AllocArgs, TUDecl,
                               /*AllowMissing=*/false, OperatorNew))
      return true;
    }
  }

  // We don't need an operator delete if we're running under
  // -fno-exceptions.
  if (!getLangOpts().Exceptions) {
    OperatorDelete = nullptr;
    return false;
  }

  // C++ [expr.new]p19:
  //
  //   If the new-expression begins with a unary :: operator, the
  //   deallocation function's name is looked up in the global
  //   scope. Otherwise, if the allocated type is a class type T or an
  //   array thereof, the deallocation function's name is looked up in
  //   the scope of T. If this lookup fails to find the name, or if
  //   the allocated type is not a class type or array thereof, the
  //   deallocation function's name is looked up in the global scope.
  LookupResult FoundDelete(*this, DeleteName, StartLoc, LookupOrdinaryName);
  if (AllocElemType->isRecordType() && !UseGlobal) {
    CXXRecordDecl *RD
      = cast<CXXRecordDecl>(AllocElemType->getAs<RecordType>()->getDecl());
    LookupQualifiedName(FoundDelete, RD);
  }
  if (FoundDelete.isAmbiguous())
    return true; // FIXME: clean up expressions?

  if (FoundDelete.empty()) {
    DeclareGlobalNewDelete();
    LookupQualifiedName(FoundDelete, Context.getTranslationUnitDecl());
  }

  FoundDelete.suppressDiagnostics();

  SmallVector<std::pair<DeclAccessPair,FunctionDecl*>, 2> Matches;

  // Whether we're looking for a placement operator delete is dictated
  // by whether we selected a placement operator new, not by whether
  // we had explicit placement arguments.  This matters for things like
  //   struct A { void *operator new(size_t, int = 0); ... };
  //   A *a = new A()
  bool isPlacementNew = (!PlaceArgs.empty() || OperatorNew->param_size() != 1);

  if (isPlacementNew) {
    // C++ [expr.new]p20:
    //   A declaration of a placement deallocation function matches the
    //   declaration of a placement allocation function if it has the
    //   same number of parameters and, after parameter transformations
    //   (8.3.5), all parameter types except the first are
    //   identical. [...]
    //
    // To perform this comparison, we compute the function type that
    // the deallocation function should have, and use that type both
    // for template argument deduction and for comparison purposes.
    //
    // FIXME: this comparison should ignore CC and the like.
    QualType ExpectedFunctionType;
    {
      const FunctionProtoType *Proto
        = OperatorNew->getType()->getAs<FunctionProtoType>();

      SmallVector<QualType, 4> ArgTypes;
      ArgTypes.push_back(Context.VoidPtrTy);
      for (unsigned I = 1, N = Proto->getNumParams(); I < N; ++I)
        ArgTypes.push_back(Proto->getParamType(I));

      FunctionProtoType::ExtProtoInfo EPI;
      EPI.Variadic = Proto->isVariadic();

      ExpectedFunctionType
        = Context.getFunctionType(Context.VoidTy, ArgTypes, EPI);
    }

    for (LookupResult::iterator D = FoundDelete.begin(),
                             DEnd = FoundDelete.end();
         D != DEnd; ++D) {
      FunctionDecl *Fn = nullptr;
      if (FunctionTemplateDecl *FnTmpl
            = dyn_cast<FunctionTemplateDecl>((*D)->getUnderlyingDecl())) {
        // Perform template argument deduction to try to match the
        // expected function type.
        TemplateDeductionInfo Info(StartLoc);
        if (DeduceTemplateArguments(FnTmpl, nullptr, ExpectedFunctionType, Fn,
                                    Info))
          continue;
      } else
        Fn = cast<FunctionDecl>((*D)->getUnderlyingDecl());

      if (Context.hasSameType(Fn->getType(), ExpectedFunctionType))
        Matches.push_back(std::make_pair(D.getPair(), Fn));
    }
  } else {
    // C++ [expr.new]p20:
    //   [...] Any non-placement deallocation function matches a
    //   non-placement allocation function. [...]
    for (LookupResult::iterator D = FoundDelete.begin(),
                             DEnd = FoundDelete.end();
         D != DEnd; ++D) {
      if (FunctionDecl *Fn = dyn_cast<FunctionDecl>((*D)->getUnderlyingDecl()))
        if (isNonPlacementDeallocationFunction(*this, Fn))
          Matches.push_back(std::make_pair(D.getPair(), Fn));
    }

    // C++1y [expr.new]p22:
    //   For a non-placement allocation function, the normal deallocation
    //   function lookup is used
    // C++1y [expr.delete]p?:
    //   If [...] deallocation function lookup finds both a usual deallocation
    //   function with only a pointer parameter and a usual deallocation
    //   function with both a pointer parameter and a size parameter, then the
    //   selected deallocation function shall be the one with two parameters.
    //   Otherwise, the selected deallocation function shall be the function
    //   with one parameter.
    if (getLangOpts().SizedDeallocation && Matches.size() == 2) {
      if (Matches[0].second->getNumParams() == 1)
        Matches.erase(Matches.begin());
      else
        Matches.erase(Matches.begin() + 1);
      assert(Matches[0].second->getNumParams() == 2 &&
             "found an unexpected usual deallocation function");
    }
  }

  // C++ [expr.new]p20:
  //   [...] If the lookup finds a single matching deallocation
  //   function, that function will be called; otherwise, no
  //   deallocation function will be called.
  if (Matches.size() == 1) {
    OperatorDelete = Matches[0].second;

    // C++0x [expr.new]p20:
    //   If the lookup finds the two-parameter form of a usual
    //   deallocation function (3.7.4.2) and that function, considered
    //   as a placement deallocation function, would have been
    //   selected as a match for the allocation function, the program
    //   is ill-formed.
    if (!PlaceArgs.empty() && getLangOpts().CPlusPlus11 &&
        isNonPlacementDeallocationFunction(*this, OperatorDelete)) {
      Diag(StartLoc, diag::err_placement_new_non_placement_delete)
        << SourceRange(PlaceArgs.front()->getLocStart(),
                       PlaceArgs.back()->getLocEnd());
      if (!OperatorDelete->isImplicit())
        Diag(OperatorDelete->getLocation(), diag::note_previous_decl)
          << DeleteName;
    } else {
      CheckAllocationAccess(StartLoc, Range, FoundDelete.getNamingClass(),
                            Matches[0].first);
    }
  }

  return false;
}

/// \brief Find an fitting overload for the allocation function
/// in the specified scope.
///
/// \param StartLoc The location of the 'new' token.
/// \param Range The range of the placement arguments.
/// \param Name The name of the function ('operator new' or 'operator new[]').
/// \param Args The placement arguments specified.
/// \param Ctx The scope in which we should search; either a class scope or the
///        translation unit.
/// \param AllowMissing If \c true, report an error if we can't find any
///        allocation functions. Otherwise, succeed but don't fill in \p
///        Operator.
/// \param Operator Filled in with the found allocation function. Unchanged if
///        no allocation function was found.
/// \param Diagnose If \c true, issue errors if the allocation function is not
///        usable.
bool Sema::FindAllocationOverload(SourceLocation StartLoc, SourceRange Range,
                                  DeclarationName Name, MultiExprArg Args,
                                  DeclContext *Ctx,
                                  bool AllowMissing, FunctionDecl *&Operator,
                                  bool Diagnose) {
  LookupResult R(*this, Name, StartLoc, LookupOrdinaryName);
  LookupQualifiedName(R, Ctx);
  if (R.empty()) {
    if (AllowMissing || !Diagnose)
      return false;
    return Diag(StartLoc, diag::err_ovl_no_viable_function_in_call)
      << Name << Range;
  }

  if (R.isAmbiguous())
    return true;

  R.suppressDiagnostics();

  OverloadCandidateSet Candidates(StartLoc, OverloadCandidateSet::CSK_Normal);
  for (LookupResult::iterator Alloc = R.begin(), AllocEnd = R.end();
       Alloc != AllocEnd; ++Alloc) {
    // Even member operator new/delete are implicitly treated as
    // static, so don't use AddMemberCandidate.
    NamedDecl *D = (*Alloc)->getUnderlyingDecl();

    if (FunctionTemplateDecl *FnTemplate = dyn_cast<FunctionTemplateDecl>(D)) {
      AddTemplateOverloadCandidate(FnTemplate, Alloc.getPair(),
                                   /*ExplicitTemplateArgs=*/nullptr,
                                   Args, Candidates,
                                   /*SuppressUserConversions=*/false);
      continue;
    }

    FunctionDecl *Fn = cast<FunctionDecl>(D);
    AddOverloadCandidate(Fn, Alloc.getPair(), Args, Candidates,
                         /*SuppressUserConversions=*/false);
  }

  // Do the resolution.
  OverloadCandidateSet::iterator Best;
  switch (Candidates.BestViableFunction(*this, StartLoc, Best)) {
  case OR_Success: {
    // Got one!
    FunctionDecl *FnDecl = Best->Function;
    if (CheckAllocationAccess(StartLoc, Range, R.getNamingClass(),
                              Best->FoundDecl, Diagnose) == AR_inaccessible)
      return true;

    Operator = FnDecl;
    return false;
  }

  case OR_No_Viable_Function:
    if (Diagnose) {
      Diag(StartLoc, diag::err_ovl_no_viable_function_in_call)
        << Name << Range;
      Candidates.NoteCandidates(*this, OCD_AllCandidates, Args);
    }
    return true;

  case OR_Ambiguous:
    if (Diagnose) {
      Diag(StartLoc, diag::err_ovl_ambiguous_call)
        << Name << Range;
      Candidates.NoteCandidates(*this, OCD_ViableCandidates, Args);
    }
    return true;

  case OR_Deleted: {
    if (Diagnose) {
      Diag(StartLoc, diag::err_ovl_deleted_call)
        << Best->Function->isDeleted()
        << Name
        << getDeletedOrUnavailableSuffix(Best->Function)
        << Range;
      Candidates.NoteCandidates(*this, OCD_AllCandidates, Args);
    }
    return true;
  }
  }
  llvm_unreachable("Unreachable, bad result from BestViableFunction");
}


/// DeclareGlobalNewDelete - Declare the global forms of operator new and
/// delete. These are:
/// @code
///   // C++03:
///   void* operator new(std::size_t) throw(std::bad_alloc);
///   void* operator new[](std::size_t) throw(std::bad_alloc);
///   void operator delete(void *) throw();
///   void operator delete[](void *) throw();
///   // C++11:
///   void* operator new(std::size_t);
///   void* operator new[](std::size_t);
///   void operator delete(void *) noexcept;
///   void operator delete[](void *) noexcept;
///   // C++1y:
///   void* operator new(std::size_t);
///   void* operator new[](std::size_t);
///   void operator delete(void *) noexcept;
///   void operator delete[](void *) noexcept;
///   void operator delete(void *, std::size_t) noexcept;
///   void operator delete[](void *, std::size_t) noexcept;
/// @endcode
/// Note that the placement and nothrow forms of new are *not* implicitly
/// declared. Their use requires including \<new\>.
void Sema::DeclareGlobalNewDelete() {
  if (GlobalNewDeleteDeclared)
    return;

  // C++ [basic.std.dynamic]p2:
  //   [...] The following allocation and deallocation functions (18.4) are
  //   implicitly declared in global scope in each translation unit of a
  //   program
  //
  //     C++03:
  //     void* operator new(std::size_t) throw(std::bad_alloc);
  //     void* operator new[](std::size_t) throw(std::bad_alloc);
  //     void  operator delete(void*) throw();
  //     void  operator delete[](void*) throw();
  //     C++11:
  //     void* operator new(std::size_t);
  //     void* operator new[](std::size_t);
  //     void  operator delete(void*) noexcept;
  //     void  operator delete[](void*) noexcept;
  //     C++1y:
  //     void* operator new(std::size_t);
  //     void* operator new[](std::size_t);
  //     void  operator delete(void*) noexcept;
  //     void  operator delete[](void*) noexcept;
  //     void  operator delete(void*, std::size_t) noexcept;
  //     void  operator delete[](void*, std::size_t) noexcept;
  //
  //   These implicit declarations introduce only the function names operator
  //   new, operator new[], operator delete, operator delete[].
  //
  // Here, we need to refer to std::bad_alloc, so we will implicitly declare
  // "std" or "bad_alloc" as necessary to form the exception specification.
  // However, we do not make these implicit declarations visible to name
  // lookup.
  if (!StdBadAlloc && !getLangOpts().CPlusPlus11) {
    // The "std::bad_alloc" class has not yet been declared, so build it
    // implicitly.
    StdBadAlloc = CXXRecordDecl::Create(Context, TTK_Class,
                                        getOrCreateStdNamespace(),
                                        SourceLocation(), SourceLocation(),
                                      &PP.getIdentifierTable().get("bad_alloc"),
                                        nullptr);
    getStdBadAlloc()->setImplicit(true);
  }

  GlobalNewDeleteDeclared = true;

  QualType VoidPtr = Context.getPointerType(Context.VoidTy);
  QualType SizeT = Context.getSizeType();

  DeclareGlobalAllocationFunction(
      Context.DeclarationNames.getCXXOperatorName(OO_New),
      VoidPtr, SizeT, QualType());
  DeclareGlobalAllocationFunction(
      Context.DeclarationNames.getCXXOperatorName(OO_Array_New),
      VoidPtr, SizeT, QualType());
  DeclareGlobalAllocationFunction(
      Context.DeclarationNames.getCXXOperatorName(OO_Delete),
      Context.VoidTy, VoidPtr);
  DeclareGlobalAllocationFunction(
      Context.DeclarationNames.getCXXOperatorName(OO_Array_Delete),
      Context.VoidTy, VoidPtr);
  if (getLangOpts().SizedDeallocation) {
    DeclareGlobalAllocationFunction(
        Context.DeclarationNames.getCXXOperatorName(OO_Delete),
        Context.VoidTy, VoidPtr, Context.getSizeType());
    DeclareGlobalAllocationFunction(
        Context.DeclarationNames.getCXXOperatorName(OO_Array_Delete),
        Context.VoidTy, VoidPtr, Context.getSizeType());
  }
}

/// DeclareGlobalAllocationFunction - Declares a single implicit global
/// allocation function if it doesn't already exist.
void Sema::DeclareGlobalAllocationFunction(DeclarationName Name,
                                           QualType Return,
                                           QualType Param1, QualType Param2) {
  DeclContext *GlobalCtx = Context.getTranslationUnitDecl();
  unsigned NumParams = Param2.isNull() ? 1 : 2;

  // Check if this function is already declared.
  DeclContext::lookup_result R = GlobalCtx->lookup(Name);
  for (DeclContext::lookup_iterator Alloc = R.begin(), AllocEnd = R.end();
       Alloc != AllocEnd; ++Alloc) {
    // Only look at non-template functions, as it is the predefined,
    // non-templated allocation function we are trying to declare here.
    if (FunctionDecl *Func = dyn_cast<FunctionDecl>(*Alloc)) {
      if (Func->getNumParams() == NumParams) {
        QualType InitialParam1Type =
            Context.getCanonicalType(Func->getParamDecl(0)
                                         ->getType().getUnqualifiedType());
        QualType InitialParam2Type =
            NumParams == 2
                ? Context.getCanonicalType(Func->getParamDecl(1)
                                               ->getType().getUnqualifiedType())
                : QualType();
        // FIXME: Do we need to check for default arguments here?
        if (InitialParam1Type == Param1 &&
            (NumParams == 1 || InitialParam2Type == Param2)) {
          // Make the function visible to name lookup, even if we found it in
          // an unimported module. It either is an implicitly-declared global
          // allocation function, or is suppressing that function.
          Func->setHidden(false);
          return;
        }
      }
    }
  }

  FunctionProtoType::ExtProtoInfo EPI;

  QualType BadAllocType;
  bool HasBadAllocExceptionSpec
    = (Name.getCXXOverloadedOperator() == OO_New ||
       Name.getCXXOverloadedOperator() == OO_Array_New);
  if (HasBadAllocExceptionSpec) {
    if (!getLangOpts().CPlusPlus11) {
      BadAllocType = Context.getTypeDeclType(getStdBadAlloc());
      assert(StdBadAlloc && "Must have std::bad_alloc declared");
      EPI.ExceptionSpec.Type = EST_Dynamic;
      EPI.ExceptionSpec.Exceptions = llvm::makeArrayRef(BadAllocType);
    }
  } else {
    EPI.ExceptionSpec =
        getLangOpts().CPlusPlus11 ? EST_BasicNoexcept : EST_DynamicNone;
  }

  QualType Params[] = { Param1, Param2 };

  QualType FnType = Context.getFunctionType(
      Return, llvm::makeArrayRef(Params, NumParams), EPI);
  FunctionDecl *Alloc =
    FunctionDecl::Create(Context, GlobalCtx, SourceLocation(),
                         SourceLocation(), Name,
                         FnType, /*TInfo=*/nullptr, SC_None, false, true);
  Alloc->setImplicit();

  // Implicit sized deallocation functions always have default visibility.
  Alloc->addAttr(VisibilityAttr::CreateImplicit(Context,
                                                VisibilityAttr::Default));

  ParmVarDecl *ParamDecls[2];
  for (unsigned I = 0; I != NumParams; ++I) {
    ParamDecls[I] = ParmVarDecl::Create(Context, Alloc, SourceLocation(),
                                        SourceLocation(), nullptr,
                                        Params[I], /*TInfo=*/nullptr,
                                        SC_None, nullptr);
    ParamDecls[I]->setImplicit();
  }
  Alloc->setParams(llvm::makeArrayRef(ParamDecls, NumParams));

  Context.getTranslationUnitDecl()->addDecl(Alloc);
  IdResolver.tryAddTopLevelDecl(Alloc, Name);
}

FunctionDecl *Sema::FindUsualDeallocationFunction(SourceLocation StartLoc,
                                                  bool CanProvideSize,
                                                  DeclarationName Name) {
  DeclareGlobalNewDelete();

  LookupResult FoundDelete(*this, Name, StartLoc, LookupOrdinaryName);
  LookupQualifiedName(FoundDelete, Context.getTranslationUnitDecl());

  // C++ [expr.new]p20:
  //   [...] Any non-placement deallocation function matches a
  //   non-placement allocation function. [...]
  llvm::SmallVector<FunctionDecl*, 2> Matches;
  for (LookupResult::iterator D = FoundDelete.begin(),
                           DEnd = FoundDelete.end();
       D != DEnd; ++D) {
    if (FunctionDecl *Fn = dyn_cast<FunctionDecl>(*D))
      if (isNonPlacementDeallocationFunction(*this, Fn))
        Matches.push_back(Fn);
  }

  // C++1y [expr.delete]p?:
  //   If the type is complete and deallocation function lookup finds both a
  //   usual deallocation function with only a pointer parameter and a usual
  //   deallocation function with both a pointer parameter and a size
  //   parameter, then the selected deallocation function shall be the one
  //   with two parameters.  Otherwise, the selected deallocation function
  //   shall be the function with one parameter.
  if (getLangOpts().SizedDeallocation && Matches.size() == 2) {
    unsigned NumArgs = CanProvideSize ? 2 : 1;
    if (Matches[0]->getNumParams() != NumArgs)
      Matches.erase(Matches.begin());
    else
      Matches.erase(Matches.begin() + 1);
    assert(Matches[0]->getNumParams() == NumArgs &&
           "found an unexpected usual deallocation function");
  }

  if (getLangOpts().CUDA)
    EraseUnwantedCUDAMatches(dyn_cast<FunctionDecl>(CurContext), Matches);

  assert(Matches.size() == 1 &&
         "unexpectedly have multiple usual deallocation functions");
  return Matches.front();
}

bool Sema::FindDeallocationFunction(SourceLocation StartLoc, CXXRecordDecl *RD,
                                    DeclarationName Name,
                                    FunctionDecl* &Operator, bool Diagnose) {
  LookupResult Found(*this, Name, StartLoc, LookupOrdinaryName);
  // Try to find operator delete/operator delete[] in class scope.
  LookupQualifiedName(Found, RD);

  if (Found.isAmbiguous())
    return true;

  Found.suppressDiagnostics();

  SmallVector<DeclAccessPair,4> Matches;
  for (LookupResult::iterator F = Found.begin(), FEnd = Found.end();
       F != FEnd; ++F) {
    NamedDecl *ND = (*F)->getUnderlyingDecl();

    // Ignore template operator delete members from the check for a usual
    // deallocation function.
    if (isa<FunctionTemplateDecl>(ND))
      continue;

    if (cast<CXXMethodDecl>(ND)->isUsualDeallocationFunction())
      Matches.push_back(F.getPair());
  }

  if (getLangOpts().CUDA)
    EraseUnwantedCUDAMatches(dyn_cast<FunctionDecl>(CurContext), Matches);

  // There's exactly one suitable operator;  pick it.
  if (Matches.size() == 1) {
    Operator = cast<CXXMethodDecl>(Matches[0]->getUnderlyingDecl());

    if (Operator->isDeleted()) {
      if (Diagnose) {
        Diag(StartLoc, diag::err_deleted_function_use);
        NoteDeletedFunction(Operator);
      }
      return true;
    }

    if (CheckAllocationAccess(StartLoc, SourceRange(), Found.getNamingClass(),
                              Matches[0], Diagnose) == AR_inaccessible)
      return true;

    return false;

  // We found multiple suitable operators;  complain about the ambiguity.
  } else if (!Matches.empty()) {
    if (Diagnose) {
      Diag(StartLoc, diag::err_ambiguous_suitable_delete_member_function_found)
        << Name << RD;

      for (SmallVectorImpl<DeclAccessPair>::iterator
             F = Matches.begin(), FEnd = Matches.end(); F != FEnd; ++F)
        Diag((*F)->getUnderlyingDecl()->getLocation(),
             diag::note_member_declared_here) << Name;
    }
    return true;
  }

  // We did find operator delete/operator delete[] declarations, but
  // none of them were suitable.
  if (!Found.empty()) {
    if (Diagnose) {
      Diag(StartLoc, diag::err_no_suitable_delete_member_function_found)
        << Name << RD;

      for (LookupResult::iterator F = Found.begin(), FEnd = Found.end();
           F != FEnd; ++F)
        Diag((*F)->getUnderlyingDecl()->getLocation(),
             diag::note_member_declared_here) << Name;
    }
    return true;
  }

  Operator = nullptr;
  return false;
}

namespace {
/// \brief Checks whether delete-expression, and new-expression used for
///  initializing deletee have the same array form.
class MismatchingNewDeleteDetector {
public:
  enum MismatchResult {
    /// Indicates that there is no mismatch or a mismatch cannot be proven.
    NoMismatch,
    /// Indicates that variable is initialized with mismatching form of \a new.
    VarInitMismatches,
    /// Indicates that member is initialized with mismatching form of \a new.
    MemberInitMismatches,
    /// Indicates that 1 or more constructors' definitions could not been
    /// analyzed, and they will be checked again at the end of translation unit.
    AnalyzeLater
  };

  /// \param EndOfTU True, if this is the final analysis at the end of
  /// translation unit. False, if this is the initial analysis at the point
  /// delete-expression was encountered.
  explicit MismatchingNewDeleteDetector(bool EndOfTU)
      : IsArrayForm(false), Field(nullptr), EndOfTU(EndOfTU),
        HasUndefinedConstructors(false) {}

  /// \brief Checks whether pointee of a delete-expression is initialized with
  /// matching form of new-expression.
  ///
  /// If return value is \c VarInitMismatches or \c MemberInitMismatches at the
  /// point where delete-expression is encountered, then a warning will be
  /// issued immediately. If return value is \c AnalyzeLater at the point where
  /// delete-expression is seen, then member will be analyzed at the end of
  /// translation unit. \c AnalyzeLater is returned iff at least one constructor
  /// couldn't be analyzed. If at least one constructor initializes the member
  /// with matching type of new, the return value is \c NoMismatch.
  MismatchResult analyzeDeleteExpr(const CXXDeleteExpr *DE);
  /// \brief Analyzes a class member.
  /// \param Field Class member to analyze.
  /// \param DeleteWasArrayForm Array form-ness of the delete-expression used
  /// for deleting the \p Field.
  MismatchResult analyzeField(FieldDecl *Field, bool DeleteWasArrayForm);
  /// List of mismatching new-expressions used for initialization of the pointee
  llvm::SmallVector<const CXXNewExpr *, 4> NewExprs;
  /// Indicates whether delete-expression was in array form.
  bool IsArrayForm;
  FieldDecl *Field;

private:
  const bool EndOfTU;
  /// \brief Indicates that there is at least one constructor without body.
  bool HasUndefinedConstructors;
  /// \brief Returns \c CXXNewExpr from given initialization expression.
  /// \param E Expression used for initializing pointee in delete-expression.
  /// E can be a single-element \c InitListExpr consisting of new-expression.
  const CXXNewExpr *getNewExprFromInitListOrExpr(const Expr *E);
  /// \brief Returns whether member is initialized with mismatching form of
  /// \c new either by the member initializer or in-class initialization.
  ///
  /// If bodies of all constructors are not visible at the end of translation
  /// unit or at least one constructor initializes member with the matching
  /// form of \c new, mismatch cannot be proven, and this function will return
  /// \c NoMismatch.
  MismatchResult analyzeMemberExpr(const MemberExpr *ME);
  /// \brief Returns whether variable is initialized with mismatching form of
  /// \c new.
  ///
  /// If variable is initialized with matching form of \c new or variable is not
  /// initialized with a \c new expression, this function will return true.
  /// If variable is initialized with mismatching form of \c new, returns false.
  /// \param D Variable to analyze.
  bool hasMatchingVarInit(const DeclRefExpr *D);
  /// \brief Checks whether the constructor initializes pointee with mismatching
  /// form of \c new.
  ///
  /// Returns true, if member is initialized with matching form of \c new in
  /// member initializer list. Returns false, if member is initialized with the
  /// matching form of \c new in this constructor's initializer or given
  /// constructor isn't defined at the point where delete-expression is seen, or
  /// member isn't initialized by the constructor.
  bool hasMatchingNewInCtor(const CXXConstructorDecl *CD);
  /// \brief Checks whether member is initialized with matching form of
  /// \c new in member initializer list.
  bool hasMatchingNewInCtorInit(const CXXCtorInitializer *CI);
  /// Checks whether member is initialized with mismatching form of \c new by
  /// in-class initializer.
  MismatchResult analyzeInClassInitializer();
};
}

MismatchingNewDeleteDetector::MismatchResult
MismatchingNewDeleteDetector::analyzeDeleteExpr(const CXXDeleteExpr *DE) {
  NewExprs.clear();
  assert(DE && "Expected delete-expression");
  IsArrayForm = DE->isArrayForm();
  const Expr *E = DE->getArgument()->IgnoreParenImpCasts();
  if (const MemberExpr *ME = dyn_cast<const MemberExpr>(E)) {
    return analyzeMemberExpr(ME);
  } else if (const DeclRefExpr *D = dyn_cast<const DeclRefExpr>(E)) {
    if (!hasMatchingVarInit(D))
      return VarInitMismatches;
  }
  return NoMismatch;
}

const CXXNewExpr *
MismatchingNewDeleteDetector::getNewExprFromInitListOrExpr(const Expr *E) {
  assert(E != nullptr && "Expected a valid initializer expression");
  E = E->IgnoreParenImpCasts();
  if (const InitListExpr *ILE = dyn_cast<const InitListExpr>(E)) {
    if (ILE->getNumInits() == 1)
      E = dyn_cast<const CXXNewExpr>(ILE->getInit(0)->IgnoreParenImpCasts());
  }

  return dyn_cast_or_null<const CXXNewExpr>(E);
}

bool MismatchingNewDeleteDetector::hasMatchingNewInCtorInit(
    const CXXCtorInitializer *CI) {
  const CXXNewExpr *NE = nullptr;
  if (Field == CI->getMember() &&
      (NE = getNewExprFromInitListOrExpr(CI->getInit()))) {
    if (NE->isArray() == IsArrayForm)
      return true;
    else
      NewExprs.push_back(NE);
  }
  return false;
}

bool MismatchingNewDeleteDetector::hasMatchingNewInCtor(
    const CXXConstructorDecl *CD) {
  if (CD->isImplicit())
    return false;
  const FunctionDecl *Definition = CD;
  if (!CD->isThisDeclarationADefinition() && !CD->isDefined(Definition)) {
    HasUndefinedConstructors = true;
    return EndOfTU;
  }
  for (const auto *CI : cast<const CXXConstructorDecl>(Definition)->inits()) {
    if (hasMatchingNewInCtorInit(CI))
      return true;
  }
  return false;
}

MismatchingNewDeleteDetector::MismatchResult
MismatchingNewDeleteDetector::analyzeInClassInitializer() {
  assert(Field != nullptr && "This should be called only for members");
  const Expr *InitExpr = Field->getInClassInitializer();
  if (!InitExpr)
    return EndOfTU ? NoMismatch : AnalyzeLater;
  if (const CXXNewExpr *NE = getNewExprFromInitListOrExpr(InitExpr)) {
    if (NE->isArray() != IsArrayForm) {
      NewExprs.push_back(NE);
      return MemberInitMismatches;
    }
  }
  return NoMismatch;
}

MismatchingNewDeleteDetector::MismatchResult
MismatchingNewDeleteDetector::analyzeField(FieldDecl *Field,
                                           bool DeleteWasArrayForm) {
  assert(Field != nullptr && "Analysis requires a valid class member.");
  this->Field = Field;
  IsArrayForm = DeleteWasArrayForm;
  const CXXRecordDecl *RD = cast<const CXXRecordDecl>(Field->getParent());
  for (const auto *CD : RD->ctors()) {
    if (hasMatchingNewInCtor(CD))
      return NoMismatch;
  }
  if (HasUndefinedConstructors)
    return EndOfTU ? NoMismatch : AnalyzeLater;
  if (!NewExprs.empty())
    return MemberInitMismatches;
  return Field->hasInClassInitializer() ? analyzeInClassInitializer()
                                        : NoMismatch;
}

MismatchingNewDeleteDetector::MismatchResult
MismatchingNewDeleteDetector::analyzeMemberExpr(const MemberExpr *ME) {
  assert(ME != nullptr && "Expected a member expression");
  if (FieldDecl *F = dyn_cast<FieldDecl>(ME->getMemberDecl()))
    return analyzeField(F, IsArrayForm);
  return NoMismatch;
}

bool MismatchingNewDeleteDetector::hasMatchingVarInit(const DeclRefExpr *D) {
  const CXXNewExpr *NE = nullptr;
  if (const VarDecl *VD = dyn_cast<const VarDecl>(D->getDecl())) {
    if (VD->hasInit() && (NE = getNewExprFromInitListOrExpr(VD->getInit())) &&
        NE->isArray() != IsArrayForm) {
      NewExprs.push_back(NE);
    }
  }
  return NewExprs.empty();
}

static void
DiagnoseMismatchedNewDelete(Sema &SemaRef, SourceLocation DeleteLoc,
                            const MismatchingNewDeleteDetector &Detector) {
  SourceLocation EndOfDelete = SemaRef.getLocForEndOfToken(DeleteLoc);
  FixItHint H;
  if (!Detector.IsArrayForm)
    H = FixItHint::CreateInsertion(EndOfDelete, "[]");
  else {
    SourceLocation RSquare = Lexer::findLocationAfterToken(
        DeleteLoc, tok::l_square, SemaRef.getSourceManager(),
        SemaRef.getLangOpts(), true);
    if (RSquare.isValid())
      H = FixItHint::CreateRemoval(SourceRange(EndOfDelete, RSquare));
  }
  SemaRef.Diag(DeleteLoc, diag::warn_mismatched_delete_new)
      << Detector.IsArrayForm << H;

  for (const auto *NE : Detector.NewExprs)
    SemaRef.Diag(NE->getExprLoc(), diag::note_allocated_here)
        << Detector.IsArrayForm;
}

void Sema::AnalyzeDeleteExprMismatch(const CXXDeleteExpr *DE) {
  if (Diags.isIgnored(diag::warn_mismatched_delete_new, SourceLocation()))
    return;
  MismatchingNewDeleteDetector Detector(/*EndOfTU=*/false);
  switch (Detector.analyzeDeleteExpr(DE)) {
  case MismatchingNewDeleteDetector::VarInitMismatches:
  case MismatchingNewDeleteDetector::MemberInitMismatches: {
    DiagnoseMismatchedNewDelete(*this, DE->getLocStart(), Detector);
    break;
  }
  case MismatchingNewDeleteDetector::AnalyzeLater: {
    DeleteExprs[Detector.Field].push_back(
        std::make_pair(DE->getLocStart(), DE->isArrayForm()));
    break;
  }
  case MismatchingNewDeleteDetector::NoMismatch:
    break;
  }
}

void Sema::AnalyzeDeleteExprMismatch(FieldDecl *Field, SourceLocation DeleteLoc,
                                     bool DeleteWasArrayForm) {
  MismatchingNewDeleteDetector Detector(/*EndOfTU=*/true);
  switch (Detector.analyzeField(Field, DeleteWasArrayForm)) {
  case MismatchingNewDeleteDetector::VarInitMismatches:
    llvm_unreachable("This analysis should have been done for class members.");
  case MismatchingNewDeleteDetector::AnalyzeLater:
    llvm_unreachable("Analysis cannot be postponed any point beyond end of "
                     "translation unit.");
  case MismatchingNewDeleteDetector::MemberInitMismatches:
    DiagnoseMismatchedNewDelete(*this, DeleteLoc, Detector);
    break;
  case MismatchingNewDeleteDetector::NoMismatch:
    break;
  }
}

/// ActOnCXXDelete - Parsed a C++ 'delete' expression (C++ 5.3.5), as in:
/// @code ::delete ptr; @endcode
/// or
/// @code delete [] ptr; @endcode
ExprResult
Sema::ActOnCXXDelete(SourceLocation StartLoc, bool UseGlobal,
                     bool ArrayForm, Expr *ExE) {
  // C++ [expr.delete]p1:
  //   The operand shall have a pointer type, or a class type having a single
  //   non-explicit conversion function to a pointer type. The result has type
  //   void.
  //
  // DR599 amends "pointer type" to "pointer to object type" in both cases.

  ExprResult Ex = ExE;
  FunctionDecl *OperatorDelete = nullptr;
  bool ArrayFormAsWritten = ArrayForm;
  bool UsualArrayDeleteWantsSize = false;

  if (!Ex.get()->isTypeDependent()) {
    // Perform lvalue-to-rvalue cast, if needed.
    Ex = DefaultLvalueConversion(Ex.get());
    if (Ex.isInvalid())
      return ExprError();

    QualType Type = Ex.get()->getType();

    class DeleteConverter : public ContextualImplicitConverter {
    public:
      DeleteConverter() : ContextualImplicitConverter(false, true) {}

      bool match(QualType ConvType) override {
        // FIXME: If we have an operator T* and an operator void*, we must pick
        // the operator T*.
        if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>())
          if (ConvPtrType->getPointeeType()->isIncompleteOrObjectType())
            return true;
        return false;
      }

      SemaDiagnosticBuilder diagnoseNoMatch(Sema &S, SourceLocation Loc,
                                            QualType T) override {
        return S.Diag(Loc, diag::err_delete_operand) << T;
      }

      SemaDiagnosticBuilder diagnoseIncomplete(Sema &S, SourceLocation Loc,
                                               QualType T) override {
        return S.Diag(Loc, diag::err_delete_incomplete_class_type) << T;
      }

      SemaDiagnosticBuilder diagnoseExplicitConv(Sema &S, SourceLocation Loc,
                                                 QualType T,
                                                 QualType ConvTy) override {
        return S.Diag(Loc, diag::err_delete_explicit_conversion) << T << ConvTy;
      }

      SemaDiagnosticBuilder noteExplicitConv(Sema &S, CXXConversionDecl *Conv,
                                             QualType ConvTy) override {
        return S.Diag(Conv->getLocation(), diag::note_delete_conversion)
          << ConvTy;
      }

      SemaDiagnosticBuilder diagnoseAmbiguous(Sema &S, SourceLocation Loc,
                                              QualType T) override {
        return S.Diag(Loc, diag::err_ambiguous_delete_operand) << T;
      }

      SemaDiagnosticBuilder noteAmbiguous(Sema &S, CXXConversionDecl *Conv,
                                          QualType ConvTy) override {
        return S.Diag(Conv->getLocation(), diag::note_delete_conversion)
          << ConvTy;
      }

      SemaDiagnosticBuilder diagnoseConversion(Sema &S, SourceLocation Loc,
                                               QualType T,
                                               QualType ConvTy) override {
        llvm_unreachable("conversion functions are permitted");
      }
    } Converter;

    Ex = PerformContextualImplicitConversion(StartLoc, Ex.get(), Converter);
    if (Ex.isInvalid())
      return ExprError();
    Type = Ex.get()->getType();
    if (!Converter.match(Type))
      // FIXME: PerformContextualImplicitConversion should return ExprError
      //        itself in this case.
      return ExprError();

    QualType Pointee = Type->getAs<PointerType>()->getPointeeType();
    QualType PointeeElem = Context.getBaseElementType(Pointee);

    if (unsigned AddressSpace = Pointee.getAddressSpace())
      return Diag(Ex.get()->getLocStart(),
                  diag::err_address_space_qualified_delete)
               << Pointee.getUnqualifiedType() << AddressSpace;

    CXXRecordDecl *PointeeRD = nullptr;
    if (Pointee->isVoidType() && !isSFINAEContext()) {
      // The C++ standard bans deleting a pointer to a non-object type, which
      // effectively bans deletion of "void*". However, most compilers support
      // this, so we treat it as a warning unless we're in a SFINAE context.
      Diag(StartLoc, diag::ext_delete_void_ptr_operand)
        << Type << Ex.get()->getSourceRange();
    } else if (Pointee->isFunctionType() || Pointee->isVoidType()) {
      return ExprError(Diag(StartLoc, diag::err_delete_operand)
        << Type << Ex.get()->getSourceRange());
    } else if (!Pointee->isDependentType()) {
      // FIXME: This can result in errors if the definition was imported from a
      // module but is hidden.
      if (!RequireCompleteType(StartLoc, Pointee,
                               diag::warn_delete_incomplete, Ex.get())) {
        if (const RecordType *RT = PointeeElem->getAs<RecordType>())
          PointeeRD = cast<CXXRecordDecl>(RT->getDecl());
      }
    }

    if (Pointee->isArrayType() && !ArrayForm) {
      Diag(StartLoc, diag::warn_delete_array_type)
          << Type << Ex.get()->getSourceRange()
          << FixItHint::CreateInsertion(getLocForEndOfToken(StartLoc), "[]");
      ArrayForm = true;
    }

    DeclarationName DeleteName = Context.DeclarationNames.getCXXOperatorName(
                                      ArrayForm ? OO_Array_Delete : OO_Delete);

    if (PointeeRD) {
      if (!UseGlobal &&
          FindDeallocationFunction(StartLoc, PointeeRD, DeleteName,
                                   OperatorDelete))
        return ExprError();

      // If we're allocating an array of records, check whether the
      // usual operator delete[] has a size_t parameter.
      if (ArrayForm) {
        // If the user specifically asked to use the global allocator,
        // we'll need to do the lookup into the class.
        if (UseGlobal)
          UsualArrayDeleteWantsSize =
            doesUsualArrayDeleteWantSize(*this, StartLoc, PointeeElem);

        // Otherwise, the usual operator delete[] should be the
        // function we just found.
        else if (OperatorDelete && isa<CXXMethodDecl>(OperatorDelete))
          UsualArrayDeleteWantsSize = (OperatorDelete->getNumParams() == 2);
      }

      if (!PointeeRD->hasIrrelevantDestructor())
        if (CXXDestructorDecl *Dtor = LookupDestructor(PointeeRD)) {
          MarkFunctionReferenced(StartLoc,
                                    const_cast<CXXDestructorDecl*>(Dtor));
          if (DiagnoseUseOfDecl(Dtor, StartLoc))
            return ExprError();
        }

      CheckVirtualDtorCall(PointeeRD->getDestructor(), StartLoc,
                           /*IsDelete=*/true, /*CallCanBeVirtual=*/true,
                           /*WarnOnNonAbstractTypes=*/!ArrayForm,
                           SourceLocation());
    }

    if (!OperatorDelete)
      // Look for a global declaration.
      OperatorDelete = FindUsualDeallocationFunction(
          StartLoc, isCompleteType(StartLoc, Pointee) &&
                    (!ArrayForm || UsualArrayDeleteWantsSize ||
                     Pointee.isDestructedType()),
          DeleteName);

    MarkFunctionReferenced(StartLoc, OperatorDelete);

    // Check access and ambiguity of operator delete and destructor.
    if (PointeeRD) {
      if (CXXDestructorDecl *Dtor = LookupDestructor(PointeeRD)) {
          CheckDestructorAccess(Ex.get()->getExprLoc(), Dtor,
                      PDiag(diag::err_access_dtor) << PointeeElem);
      }
    }
  }

  CXXDeleteExpr *Result = new (Context) CXXDeleteExpr(
      Context.VoidTy, UseGlobal, ArrayForm, ArrayFormAsWritten,
      UsualArrayDeleteWantsSize, OperatorDelete, Ex.get(), StartLoc);
  AnalyzeDeleteExprMismatch(Result);
  return Result;
}

void Sema::CheckVirtualDtorCall(CXXDestructorDecl *dtor, SourceLocation Loc,
                                bool IsDelete, bool CallCanBeVirtual,
                                bool WarnOnNonAbstractTypes,
                                SourceLocation DtorLoc) {
  if (!dtor || dtor->isVirtual() || !CallCanBeVirtual)
    return;

  // C++ [expr.delete]p3:
  //   In the first alternative (delete object), if the static type of the
  //   object to be deleted is different from its dynamic type, the static
  //   type shall be a base class of the dynamic type of the object to be
  //   deleted and the static type shall have a virtual destructor or the
  //   behavior is undefined.
  //
  const CXXRecordDecl *PointeeRD = dtor->getParent();
  // Note: a final class cannot be derived from, no issue there
  if (!PointeeRD->isPolymorphic() || PointeeRD->hasAttr<FinalAttr>())
    return;

  QualType ClassType = dtor->getThisType(Context)->getPointeeType();
  if (PointeeRD->isAbstract()) {
    // If the class is abstract, we warn by default, because we're
    // sure the code has undefined behavior.
    Diag(Loc, diag::warn_delete_abstract_non_virtual_dtor) << (IsDelete ? 0 : 1)
                                                           << ClassType;
  } else if (WarnOnNonAbstractTypes) {
    // Otherwise, if this is not an array delete, it's a bit suspect,
    // but not necessarily wrong.
    Diag(Loc, diag::warn_delete_non_virtual_dtor) << (IsDelete ? 0 : 1)
                                                  << ClassType;
  }
  if (!IsDelete) {
    std::string TypeStr;
    ClassType.getAsStringInternal(TypeStr, getPrintingPolicy());
    Diag(DtorLoc, diag::note_delete_non_virtual)
        << FixItHint::CreateInsertion(DtorLoc, TypeStr + "::");
  }
}

Sema::ConditionResult Sema::ActOnConditionVariable(Decl *ConditionVar,
                                                   SourceLocation StmtLoc,
                                                   ConditionKind CK) {
  ExprResult E =
      CheckConditionVariable(cast<VarDecl>(ConditionVar), StmtLoc, CK);
  if (E.isInvalid())
    return ConditionError();
  return ConditionResult(*this, ConditionVar, MakeFullExpr(E.get(), StmtLoc),
                         CK == ConditionKind::ConstexprIf);
}

/// \brief Check the use of the given variable as a C++ condition in an if,
/// while, do-while, or switch statement.
ExprResult Sema::CheckConditionVariable(VarDecl *ConditionVar,
                                        SourceLocation StmtLoc,
                                        ConditionKind CK) {
  if (ConditionVar->isInvalidDecl())
    return ExprError();

  QualType T = ConditionVar->getType();

  // C++ [stmt.select]p2:
  //   The declarator shall not specify a function or an array.
  if (T->isFunctionType())
    return ExprError(Diag(ConditionVar->getLocation(),
                          diag::err_invalid_use_of_function_type)
                       << ConditionVar->getSourceRange());
  else if (T->isArrayType())
    return ExprError(Diag(ConditionVar->getLocation(),
                          diag::err_invalid_use_of_array_type)
                     << ConditionVar->getSourceRange());

  ExprResult Condition = DeclRefExpr::Create(
      Context, NestedNameSpecifierLoc(), SourceLocation(), ConditionVar,
      /*enclosing*/ false, ConditionVar->getLocation(),
      ConditionVar->getType().getNonReferenceType(), VK_LValue);

  MarkDeclRefReferenced(cast<DeclRefExpr>(Condition.get()));

  switch (CK) {
  case ConditionKind::Boolean:
    return CheckBooleanCondition(StmtLoc, Condition.get());

  case ConditionKind::ConstexprIf:
    return CheckBooleanCondition(StmtLoc, Condition.get(), true);

  case ConditionKind::Switch:
    return CheckSwitchCondition(StmtLoc, Condition.get());
  }

  llvm_unreachable("unexpected condition kind");
}

/// CheckCXXBooleanCondition - Returns true if a conversion to bool is invalid.
ExprResult Sema::CheckCXXBooleanCondition(Expr *CondExpr, bool IsConstexpr) {
  // C++ 6.4p4:
  // The value of a condition that is an initialized declaration in a statement
  // other than a switch statement is the value of the declared variable
  // implicitly converted to type bool. If that conversion is ill-formed, the
  // program is ill-formed.
  // The value of a condition that is an expression is the value of the
  // expression, implicitly converted to bool.
  //
  // FIXME: Return this value to the caller so they don't need to recompute it.
  llvm::APSInt Value(/*BitWidth*/1);
  return (IsConstexpr && !CondExpr->isValueDependent())
             ? CheckConvertedConstantExpression(CondExpr, Context.BoolTy, Value,
                                                CCEK_ConstexprIf)
             : PerformContextuallyConvertToBool(CondExpr);
}

/// Helper function to determine whether this is the (deprecated) C++
/// conversion from a string literal to a pointer to non-const char or
/// non-const wchar_t (for narrow and wide string literals,
/// respectively).
bool
Sema::IsStringLiteralToNonConstPointerConversion(Expr *From, QualType ToType) {
  // Look inside the implicit cast, if it exists.
  if (ImplicitCastExpr *Cast = dyn_cast<ImplicitCastExpr>(From))
    From = Cast->getSubExpr();

  // A string literal (2.13.4) that is not a wide string literal can
  // be converted to an rvalue of type "pointer to char"; a wide
  // string literal can be converted to an rvalue of type "pointer
  // to wchar_t" (C++ 4.2p2).
  if (StringLiteral *StrLit = dyn_cast<StringLiteral>(From->IgnoreParens()))
    if (const PointerType *ToPtrType = ToType->getAs<PointerType>())
      if (const BuiltinType *ToPointeeType
          = ToPtrType->getPointeeType()->getAs<BuiltinType>()) {
        // This conversion is considered only when there is an
        // explicit appropriate pointer target type (C++ 4.2p2).
        if (!ToPtrType->getPointeeType().hasQualifiers()) {
          switch (StrLit->getKind()) {
            case StringLiteral::UTF8:
            case StringLiteral::UTF16:
            case StringLiteral::UTF32:
              // We don't allow UTF literals to be implicitly converted
              break;
            case StringLiteral::Ascii:
              return (ToPointeeType->getKind() == BuiltinType::Char_U ||
                      ToPointeeType->getKind() == BuiltinType::Char_S);
            case StringLiteral::Wide:
              return Context.typesAreCompatible(Context.getWideCharType(),
                                                QualType(ToPointeeType, 0));
          }
        }
      }

  return false;
}

static ExprResult BuildCXXCastArgument(Sema &S,
                                       SourceLocation CastLoc,
                                       QualType Ty,
                                       CastKind Kind,
                                       CXXMethodDecl *Method,
                                       DeclAccessPair FoundDecl,
                                       bool HadMultipleCandidates,
                                       Expr *From) {
  switch (Kind) {
  default: llvm_unreachable("Unhandled cast kind!");
  case CK_ConstructorConversion: {
    CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(Method);
    SmallVector<Expr*, 8> ConstructorArgs;

    if (S.RequireNonAbstractType(CastLoc, Ty,
                                 diag::err_allocation_of_abstract_type))
      return ExprError();

    if (S.CompleteConstructorCall(Constructor, From, CastLoc, ConstructorArgs))
      return ExprError();

    S.CheckConstructorAccess(CastLoc, Constructor, FoundDecl,
                             InitializedEntity::InitializeTemporary(Ty));
    if (S.DiagnoseUseOfDecl(Method, CastLoc))
      return ExprError();

    ExprResult Result = S.BuildCXXConstructExpr(
        CastLoc, Ty, FoundDecl, cast<CXXConstructorDecl>(Method),
        ConstructorArgs, HadMultipleCandidates,
        /*ListInit*/ false, /*StdInitListInit*/ false, /*ZeroInit*/ false,
        CXXConstructExpr::CK_Complete, SourceRange());
    if (Result.isInvalid())
      return ExprError();

    return S.MaybeBindToTemporary(Result.getAs<Expr>());
  }

  case CK_UserDefinedConversion: {
    assert(!From->getType()->isPointerType() && "Arg can't have pointer type!");

    S.CheckMemberOperatorAccess(CastLoc, From, /*arg*/ nullptr, FoundDecl);
    if (S.DiagnoseUseOfDecl(Method, CastLoc))
      return ExprError();

    // Create an implicit call expr that calls it.
    CXXConversionDecl *Conv = cast<CXXConversionDecl>(Method);
    ExprResult Result = S.BuildCXXMemberCallExpr(From, FoundDecl, Conv,
                                                 HadMultipleCandidates);
    if (Result.isInvalid())
      return ExprError();
    // Record usage of conversion in an implicit cast.
    Result = ImplicitCastExpr::Create(S.Context, Result.get()->getType(),
                                      CK_UserDefinedConversion, Result.get(),
                                      nullptr, Result.get()->getValueKind());

    return S.MaybeBindToTemporary(Result.get());
  }
  }
}

/// PerformImplicitConversion - Perform an implicit conversion of the
/// expression From to the type ToType using the pre-computed implicit
/// conversion sequence ICS. Returns the converted
/// expression. Action is the kind of conversion we're performing,
/// used in the error message.
ExprResult
Sema::PerformImplicitConversion(Expr *From, QualType ToType,
                                const ImplicitConversionSequence &ICS,
                                AssignmentAction Action,
                                CheckedConversionKind CCK) {
  switch (ICS.getKind()) {
  case ImplicitConversionSequence::StandardConversion: {
    ExprResult Res = PerformImplicitConversion(From, ToType, ICS.Standard,
                                               Action, CCK);
    if (Res.isInvalid())
      return ExprError();
    From = Res.get();
    break;
  }

  case ImplicitConversionSequence::UserDefinedConversion: {

      FunctionDecl *FD = ICS.UserDefined.ConversionFunction;
      CastKind CastKind;
      QualType BeforeToType;
      assert(FD && "no conversion function for user-defined conversion seq");
      if (const CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(FD)) {
        CastKind = CK_UserDefinedConversion;

        // If the user-defined conversion is specified by a conversion function,
        // the initial standard conversion sequence converts the source type to
        // the implicit object parameter of the conversion function.
        BeforeToType = Context.getTagDeclType(Conv->getParent());
      } else {
        const CXXConstructorDecl *Ctor = cast<CXXConstructorDecl>(FD);
        CastKind = CK_ConstructorConversion;
        // Do no conversion if dealing with ... for the first conversion.
        if (!ICS.UserDefined.EllipsisConversion) {
          // If the user-defined conversion is specified by a constructor, the
          // initial standard conversion sequence converts the source type to
          // the type required by the argument of the constructor
          BeforeToType = Ctor->getParamDecl(0)->getType().getNonReferenceType();
        }
      }
      // Watch out for ellipsis conversion.
      if (!ICS.UserDefined.EllipsisConversion) {
        ExprResult Res =
          PerformImplicitConversion(From, BeforeToType,
                                    ICS.UserDefined.Before, AA_Converting,
                                    CCK);
        if (Res.isInvalid())
          return ExprError();
        From = Res.get();
      }

      ExprResult CastArg
        = BuildCXXCastArgument(*this,
                               From->getLocStart(),
                               ToType.getNonReferenceType(),
                               CastKind, cast<CXXMethodDecl>(FD),
                               ICS.UserDefined.FoundConversionFunction,
                               ICS.UserDefined.HadMultipleCandidates,
                               From);

      if (CastArg.isInvalid())
        return ExprError();

      From = CastArg.get();

      return PerformImplicitConversion(From, ToType, ICS.UserDefined.After,
                                       AA_Converting, CCK);
  }

  case ImplicitConversionSequence::AmbiguousConversion:
    ICS.DiagnoseAmbiguousConversion(*this, From->getExprLoc(),
                          PDiag(diag::err_typecheck_ambiguous_condition)
                            << From->getSourceRange());
     return ExprError();

  case ImplicitConversionSequence::EllipsisConversion:
    llvm_unreachable("Cannot perform an ellipsis conversion");

  case ImplicitConversionSequence::BadConversion:
    return ExprError();
  }

  // Everything went well.
  return From;
}

/// PerformImplicitConversion - Perform an implicit conversion of the
/// expression From to the type ToType by following the standard
/// conversion sequence SCS. Returns the converted
/// expression. Flavor is the context in which we're performing this
/// conversion, for use in error messages.
ExprResult
Sema::PerformImplicitConversion(Expr *From, QualType ToType,
                                const StandardConversionSequence& SCS,
                                AssignmentAction Action,
                                CheckedConversionKind CCK) {
  bool CStyle = (CCK == CCK_CStyleCast || CCK == CCK_FunctionalCast);

  // Overall FIXME: we are recomputing too many types here and doing far too
  // much extra work. What this means is that we need to keep track of more
  // information that is computed when we try the implicit conversion initially,
  // so that we don't need to recompute anything here.
  QualType FromType = From->getType();

  if (SCS.CopyConstructor) {
    // FIXME: When can ToType be a reference type?
    assert(!ToType->isReferenceType());
    if (SCS.Second == ICK_Derived_To_Base) {
      SmallVector<Expr*, 8> ConstructorArgs;
      if (CompleteConstructorCall(cast<CXXConstructorDecl>(SCS.CopyConstructor),
                                  From, /*FIXME:ConstructLoc*/SourceLocation(),
                                  ConstructorArgs))
        return ExprError();
      return BuildCXXConstructExpr(
          /*FIXME:ConstructLoc*/ SourceLocation(), ToType,
          SCS.FoundCopyConstructor, SCS.CopyConstructor,
          ConstructorArgs, /*HadMultipleCandidates*/ false,
          /*ListInit*/ false, /*StdInitListInit*/ false, /*ZeroInit*/ false,
          CXXConstructExpr::CK_Complete, SourceRange());
    }
    return BuildCXXConstructExpr(
        /*FIXME:ConstructLoc*/ SourceLocation(), ToType,
        SCS.FoundCopyConstructor, SCS.CopyConstructor,
        From, /*HadMultipleCandidates*/ false,
        /*ListInit*/ false, /*StdInitListInit*/ false, /*ZeroInit*/ false,
        CXXConstructExpr::CK_Complete, SourceRange());
  }

  // Resolve overloaded function references.
  if (Context.hasSameType(FromType, Context.OverloadTy)) {
    DeclAccessPair Found;
    FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(From, ToType,
                                                          true, Found);
    if (!Fn)
      return ExprError();

    if (DiagnoseUseOfDecl(Fn, From->getLocStart()))
      return ExprError();

    From = FixOverloadedFunctionReference(From, Found, Fn);
    FromType = From->getType();
  }

  // If we're converting to an atomic type, first convert to the corresponding
  // non-atomic type.
  QualType ToAtomicType;
  if (const AtomicType *ToAtomic = ToType->getAs<AtomicType>()) {
    ToAtomicType = ToType;
    ToType = ToAtomic->getValueType();
  }

  QualType InitialFromType = FromType;
  // Perform the first implicit conversion.
  switch (SCS.First) {
  case ICK_Identity:
    if (const AtomicType *FromAtomic = FromType->getAs<AtomicType>()) {
      FromType = FromAtomic->getValueType().getUnqualifiedType();
      From = ImplicitCastExpr::Create(Context, FromType, CK_AtomicToNonAtomic,
                                      From, /*BasePath=*/nullptr, VK_RValue);
    }
    break;

  case ICK_Lvalue_To_Rvalue: {
    assert(From->getObjectKind() != OK_ObjCProperty);
    ExprResult FromRes = DefaultLvalueConversion(From);
    assert(!FromRes.isInvalid() && "Can't perform deduced conversion?!");
    From = FromRes.get();
    FromType = From->getType();
    break;
  }

  case ICK_Array_To_Pointer:
    FromType = Context.getArrayDecayedType(FromType);
    From = ImpCastExprToType(From, FromType, CK_ArrayToPointerDecay,
                             VK_RValue, /*BasePath=*/nullptr, CCK).get();
    break;

  case ICK_Function_To_Pointer:
    FromType = Context.getPointerType(FromType);
    From = ImpCastExprToType(From, FromType, CK_FunctionToPointerDecay,
                             VK_RValue, /*BasePath=*/nullptr, CCK).get();
    break;

  default:
    llvm_unreachable("Improper first standard conversion");
  }

  // Perform the second implicit conversion
  switch (SCS.Second) {
  case ICK_Identity:
    // C++ [except.spec]p5:
    //   [For] assignment to and initialization of pointers to functions,
    //   pointers to member functions, and references to functions: the
    //   target entity shall allow at least the exceptions allowed by the
    //   source value in the assignment or initialization.
    switch (Action) {
    case AA_Assigning:
    case AA_Initializing:
      // Note, function argument passing and returning are initialization.
    case AA_Passing:
    case AA_Returning:
    case AA_Sending:
    case AA_Passing_CFAudited:
      if (CheckExceptionSpecCompatibility(From, ToType))
        return ExprError();
      break;

    case AA_Casting:
    case AA_Converting:
      // Casts and implicit conversions are not initialization, so are not
      // checked for exception specification mismatches.
      break;
    }
    // Nothing else to do.
    break;

  case ICK_NoReturn_Adjustment:
    // If both sides are functions (or pointers/references to them), there could
    // be incompatible exception declarations.
    if (CheckExceptionSpecCompatibility(From, ToType))
      return ExprError();

    From = ImpCastExprToType(From, ToType, CK_NoOp,
                             VK_RValue, /*BasePath=*/nullptr, CCK).get();
    break;

  case ICK_Integral_Promotion:
  case ICK_Integral_Conversion:
    if (ToType->isBooleanType()) {
      assert(FromType->castAs<EnumType>()->getDecl()->isFixed() &&
             SCS.Second == ICK_Integral_Promotion &&
             "only enums with fixed underlying type can promote to bool");
      From = ImpCastExprToType(From, ToType, CK_IntegralToBoolean,
                               VK_RValue, /*BasePath=*/nullptr, CCK).get();
    } else {
      From = ImpCastExprToType(From, ToType, CK_IntegralCast,
                               VK_RValue, /*BasePath=*/nullptr, CCK).get();
    }
    break;

  case ICK_Floating_Promotion:
  case ICK_Floating_Conversion:
    From = ImpCastExprToType(From, ToType, CK_FloatingCast,
                             VK_RValue, /*BasePath=*/nullptr, CCK).get();
    break;

  case ICK_Complex_Promotion:
  case ICK_Complex_Conversion: {
    QualType FromEl = From->getType()->getAs<ComplexType>()->getElementType();
    QualType ToEl = ToType->getAs<ComplexType>()->getElementType();
    CastKind CK;
    if (FromEl->isRealFloatingType()) {
      if (ToEl->isRealFloatingType())
        CK = CK_FloatingComplexCast;
      else
        CK = CK_FloatingComplexToIntegralComplex;
    } else if (ToEl->isRealFloatingType()) {
      CK = CK_IntegralComplexToFloatingComplex;
    } else {
      CK = CK_IntegralComplexCast;
    }
    From = ImpCastExprToType(From, ToType, CK,
                             VK_RValue, /*BasePath=*/nullptr, CCK).get();
    break;
  }

  case ICK_Floating_Integral:
    if (ToType->isRealFloatingType())
      From = ImpCastExprToType(From, ToType, CK_IntegralToFloating,
                               VK_RValue, /*BasePath=*/nullptr, CCK).get();
    else
      From = ImpCastExprToType(From, ToType, CK_FloatingToIntegral,
                               VK_RValue, /*BasePath=*/nullptr, CCK).get();
    break;

  case ICK_Compatible_Conversion:
      From = ImpCastExprToType(From, ToType, CK_NoOp,
                               VK_RValue, /*BasePath=*/nullptr, CCK).get();
    break;

  case ICK_Writeback_Conversion:
  case ICK_Pointer_Conversion: {
    if (SCS.IncompatibleObjC && Action != AA_Casting) {
      // Diagnose incompatible Objective-C conversions
      if (Action == AA_Initializing || Action == AA_Assigning)
        Diag(From->getLocStart(),
             diag::ext_typecheck_convert_incompatible_pointer)
          << ToType << From->getType() << Action
          << From->getSourceRange() << 0;
      else
        Diag(From->getLocStart(),
             diag::ext_typecheck_convert_incompatible_pointer)
          << From->getType() << ToType << Action
          << From->getSourceRange() << 0;

      if (From->getType()->isObjCObjectPointerType() &&
          ToType->isObjCObjectPointerType())
        EmitRelatedResultTypeNote(From);
    }
    else if (getLangOpts().ObjCAutoRefCount &&
             !CheckObjCARCUnavailableWeakConversion(ToType,
                                                    From->getType())) {
      if (Action == AA_Initializing)
        Diag(From->getLocStart(),
             diag::err_arc_weak_unavailable_assign);
      else
        Diag(From->getLocStart(),
             diag::err_arc_convesion_of_weak_unavailable)
          << (Action == AA_Casting) << From->getType() << ToType
          << From->getSourceRange();
    }

    CastKind Kind = CK_Invalid;
    CXXCastPath BasePath;
    if (CheckPointerConversion(From, ToType, Kind, BasePath, CStyle))
      return ExprError();

    // Make sure we extend blocks if necessary.
    // FIXME: doing this here is really ugly.
    if (Kind == CK_BlockPointerToObjCPointerCast) {
      ExprResult E = From;
      (void) PrepareCastToObjCObjectPointer(E);
      From = E.get();
    }
    if (getLangOpts().ObjCAutoRefCount)
      CheckObjCARCConversion(SourceRange(), ToType, From, CCK);
    From = ImpCastExprToType(From, ToType, Kind, VK_RValue, &BasePath, CCK)
             .get();
    break;
  }

  case ICK_Pointer_Member: {
    CastKind Kind = CK_Invalid;
    CXXCastPath BasePath;
    if (CheckMemberPointerConversion(From, ToType, Kind, BasePath, CStyle))
      return ExprError();
    if (CheckExceptionSpecCompatibility(From, ToType))
      return ExprError();

    // We may not have been able to figure out what this member pointer resolved
    // to up until this exact point.  Attempt to lock-in it's inheritance model.
    if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
      (void)isCompleteType(From->getExprLoc(), From->getType());
      (void)isCompleteType(From->getExprLoc(), ToType);
    }

    From = ImpCastExprToType(From, ToType, Kind, VK_RValue, &BasePath, CCK)
             .get();
    break;
  }

  case ICK_Boolean_Conversion:
    // Perform half-to-boolean conversion via float.
    if (From->getType()->isHalfType()) {
      From = ImpCastExprToType(From, Context.FloatTy, CK_FloatingCast).get();
      FromType = Context.FloatTy;
    }

    From = ImpCastExprToType(From, Context.BoolTy,
                             ScalarTypeToBooleanCastKind(FromType),
                             VK_RValue, /*BasePath=*/nullptr, CCK).get();
    break;

  case ICK_Derived_To_Base: {
    CXXCastPath BasePath;
    if (CheckDerivedToBaseConversion(From->getType(),
                                     ToType.getNonReferenceType(),
                                     From->getLocStart(),
                                     From->getSourceRange(),
                                     &BasePath,
                                     CStyle))
      return ExprError();

    From = ImpCastExprToType(From, ToType.getNonReferenceType(),
                      CK_DerivedToBase, From->getValueKind(),
                      &BasePath, CCK).get();
    break;
  }

  case ICK_Vector_Conversion:
    From = ImpCastExprToType(From, ToType, CK_BitCast,
                             VK_RValue, /*BasePath=*/nullptr, CCK).get();
    break;

  case ICK_Vector_Splat: {
    // Vector splat from any arithmetic type to a vector.
    Expr *Elem = prepareVectorSplat(ToType, From).get();
    From = ImpCastExprToType(Elem, ToType, CK_VectorSplat, VK_RValue,
                             /*BasePath=*/nullptr, CCK).get();
    break;
  }

  case ICK_Complex_Real:
    // Case 1.  x -> _Complex y
    if (const ComplexType *ToComplex = ToType->getAs<ComplexType>()) {
      QualType ElType = ToComplex->getElementType();
      bool isFloatingComplex = ElType->isRealFloatingType();

      // x -> y
      if (Context.hasSameUnqualifiedType(ElType, From->getType())) {
        // do nothing
      } else if (From->getType()->isRealFloatingType()) {
        From = ImpCastExprToType(From, ElType,
                isFloatingComplex ? CK_FloatingCast : CK_FloatingToIntegral).get();
      } else {
        assert(From->getType()->isIntegerType());
        From = ImpCastExprToType(From, ElType,
                isFloatingComplex ? CK_IntegralToFloating : CK_IntegralCast).get();
      }
      // y -> _Complex y
      From = ImpCastExprToType(From, ToType,
                   isFloatingComplex ? CK_FloatingRealToComplex
                                     : CK_IntegralRealToComplex).get();

    // Case 2.  _Complex x -> y
    } else {
      const ComplexType *FromComplex = From->getType()->getAs<ComplexType>();
      assert(FromComplex);