Remove LLVM 8.0.1 files.

1 files changed, 0 insertions, 11737 deletions

diff --git a/gnu/llvm/tools/clang/lib/AST/ExprConstant.cpp b/gnu/llvm/tools/clang/lib/AST/ExprConstant.cpp
deleted file mode 100644
index bfe6c78a0dd..00000000000
--- a/gnu/llvm/tools/clang/lib/AST/ExprConstant.cpp
+++ /dev/null
@@ -1,11737 +0,0 @@
-//===--- ExprConstant.cpp - Expression Constant Evaluator -----------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file implements the Expr constant evaluator.
-//
-// Constant expression evaluation produces four main results:
-//
-//  * A success/failure flag indicating whether constant folding was successful.
-//    This is the 'bool' return value used by most of the code in this file. A
-//    'false' return value indicates that constant folding has failed, and any
-//    appropriate diagnostic has already been produced.
-//
-//  * An evaluated result, valid only if constant folding has not failed.
-//
-//  * A flag indicating if evaluation encountered (unevaluated) side-effects.
-//    These arise in cases such as (sideEffect(), 0) and (sideEffect() || 1),
-//    where it is possible to determine the evaluated result regardless.
-//
-//  * A set of notes indicating why the evaluation was not a constant expression
-//    (under the C++11 / C++1y rules only, at the moment), or, if folding failed
-//    too, why the expression could not be folded.
-//
-// If we are checking for a potential constant expression, failure to constant
-// fold a potential constant sub-expression will be indicated by a 'false'
-// return value (the expression could not be folded) and no diagnostic (the
-// expression is not necessarily non-constant).
-//
-//===----------------------------------------------------------------------===//
-
-#include "clang/AST/APValue.h"
-#include "clang/AST/ASTContext.h"
-#include "clang/AST/ASTDiagnostic.h"
-#include "clang/AST/ASTLambda.h"
-#include "clang/AST/CharUnits.h"
-#include "clang/AST/Expr.h"
-#include "clang/AST/OSLog.h"
-#include "clang/AST/RecordLayout.h"
-#include "clang/AST/StmtVisitor.h"
-#include "clang/AST/TypeLoc.h"
-#include "clang/Basic/Builtins.h"
-#include "clang/Basic/TargetInfo.h"
-#include "llvm/Support/SaveAndRestore.h"
-#include "llvm/Support/raw_ostream.h"
-#include <cstring>
-#include <functional>
-
-#define DEBUG_TYPE "exprconstant"
-
-using namespace clang;
-using llvm::APSInt;
-using llvm::APFloat;
-
-static bool IsGlobalLValue(APValue::LValueBase B);
-
-namespace {
-  struct LValue;
-  struct CallStackFrame;
-  struct EvalInfo;
-
-  static QualType getType(APValue::LValueBase B) {
-    if (!B) return QualType();
-    if (const ValueDecl *D = B.dyn_cast<const ValueDecl*>()) {
-      // FIXME: It's unclear where we're supposed to take the type from, and
-      // this actually matters for arrays of unknown bound. Eg:
-      //
-      // extern int arr[]; void f() { extern int arr[3]; };
-      // constexpr int *p = &arr[1]; // valid?
-      //
-      // For now, we take the array bound from the most recent declaration.
-      for (auto *Redecl = cast<ValueDecl>(D->getMostRecentDecl()); Redecl;
-           Redecl = cast_or_null<ValueDecl>(Redecl->getPreviousDecl())) {
-        QualType T = Redecl->getType();
-        if (!T->isIncompleteArrayType())
-          return T;
-      }
-      return D->getType();
-    }
-
-    const Expr *Base = B.get<const Expr*>();
-
-    // For a materialized temporary, the type of the temporary we materialized
-    // may not be the type of the expression.
-    if (const MaterializeTemporaryExpr *MTE =
-            dyn_cast<MaterializeTemporaryExpr>(Base)) {
-      SmallVector<const Expr *, 2> CommaLHSs;
-      SmallVector<SubobjectAdjustment, 2> Adjustments;
-      const Expr *Temp = MTE->GetTemporaryExpr();
-      const Expr *Inner = Temp->skipRValueSubobjectAdjustments(CommaLHSs,
-                                                               Adjustments);
-      // Keep any cv-qualifiers from the reference if we generated a temporary
-      // for it directly. Otherwise use the type after adjustment.
-      if (!Adjustments.empty())
-        return Inner->getType();
-    }
-
-    return Base->getType();
-  }
-
-  /// Get an LValue path entry, which is known to not be an array index, as a
-  /// field or base class.
-  static
-  APValue::BaseOrMemberType getAsBaseOrMember(APValue::LValuePathEntry E) {
-    APValue::BaseOrMemberType Value;
-    Value.setFromOpaqueValue(E.BaseOrMember);
-    return Value;
-  }
-
-  /// Get an LValue path entry, which is known to not be an array index, as a
-  /// field declaration.
-  static const FieldDecl *getAsField(APValue::LValuePathEntry E) {
-    return dyn_cast<FieldDecl>(getAsBaseOrMember(E).getPointer());
-  }
-  /// Get an LValue path entry, which is known to not be an array index, as a
-  /// base class declaration.
-  static const CXXRecordDecl *getAsBaseClass(APValue::LValuePathEntry E) {
-    return dyn_cast<CXXRecordDecl>(getAsBaseOrMember(E).getPointer());
-  }
-  /// Determine whether this LValue path entry for a base class names a virtual
-  /// base class.
-  static bool isVirtualBaseClass(APValue::LValuePathEntry E) {
-    return getAsBaseOrMember(E).getInt();
-  }
-
-  /// Given a CallExpr, try to get the alloc_size attribute. May return null.
-  static const AllocSizeAttr *getAllocSizeAttr(const CallExpr *CE) {
-    const FunctionDecl *Callee = CE->getDirectCallee();
-    return Callee ? Callee->getAttr<AllocSizeAttr>() : nullptr;
-  }
-
-  /// Attempts to unwrap a CallExpr (with an alloc_size attribute) from an Expr.
-  /// This will look through a single cast.
-  ///
-  /// Returns null if we couldn't unwrap a function with alloc_size.
-  static const CallExpr *tryUnwrapAllocSizeCall(const Expr *E) {
-    if (!E->getType()->isPointerType())
-      return nullptr;
-
-    E = E->IgnoreParens();
-    // If we're doing a variable assignment from e.g. malloc(N), there will
-    // probably be a cast of some kind. In exotic cases, we might also see a
-    // top-level ExprWithCleanups. Ignore them either way.
-    if (const auto *FE = dyn_cast<FullExpr>(E))
-      E = FE->getSubExpr()->IgnoreParens();
-
-    if (const auto *Cast = dyn_cast<CastExpr>(E))
-      E = Cast->getSubExpr()->IgnoreParens();
-
-    if (const auto *CE = dyn_cast<CallExpr>(E))
-      return getAllocSizeAttr(CE) ? CE : nullptr;
-    return nullptr;
-  }
-
-  /// Determines whether or not the given Base contains a call to a function
-  /// with the alloc_size attribute.
-  static bool isBaseAnAllocSizeCall(APValue::LValueBase Base) {
-    const auto *E = Base.dyn_cast<const Expr *>();
-    return E && E->getType()->isPointerType() && tryUnwrapAllocSizeCall(E);
-  }
-
-  /// The bound to claim that an array of unknown bound has.
-  /// The value in MostDerivedArraySize is undefined in this case. So, set it
-  /// to an arbitrary value that's likely to loudly break things if it's used.
-  static const uint64_t AssumedSizeForUnsizedArray =
-      std::numeric_limits<uint64_t>::max() / 2;
-
-  /// Determines if an LValue with the given LValueBase will have an unsized
-  /// array in its designator.
-  /// Find the path length and type of the most-derived subobject in the given
-  /// path, and find the size of the containing array, if any.
-  static unsigned
-  findMostDerivedSubobject(ASTContext &Ctx, APValue::LValueBase Base,
-                           ArrayRef<APValue::LValuePathEntry> Path,
-                           uint64_t &ArraySize, QualType &Type, bool &IsArray,
-                           bool &FirstEntryIsUnsizedArray) {
-    // This only accepts LValueBases from APValues, and APValues don't support
-    // arrays that lack size info.
-    assert(!isBaseAnAllocSizeCall(Base) &&
-           "Unsized arrays shouldn't appear here");
-    unsigned MostDerivedLength = 0;
-    Type = getType(Base);
-
-    for (unsigned I = 0, N = Path.size(); I != N; ++I) {
-      if (Type->isArrayType()) {
-        const ArrayType *AT = Ctx.getAsArrayType(Type);
-        Type = AT->getElementType();
-        MostDerivedLength = I + 1;
-        IsArray = true;
-
-        if (auto *CAT = dyn_cast<ConstantArrayType>(AT)) {
-          ArraySize = CAT->getSize().getZExtValue();
-        } else {
-          assert(I == 0 && "unexpected unsized array designator");
-          FirstEntryIsUnsizedArray = true;
-          ArraySize = AssumedSizeForUnsizedArray;
-        }
-      } else if (Type->isAnyComplexType()) {
-        const ComplexType *CT = Type->castAs<ComplexType>();
-        Type = CT->getElementType();
-        ArraySize = 2;
-        MostDerivedLength = I + 1;
-        IsArray = true;
-      } else if (const FieldDecl *FD = getAsField(Path[I])) {
-        Type = FD->getType();
-        ArraySize = 0;
-        MostDerivedLength = I + 1;
-        IsArray = false;
-      } else {
-        // Path[I] describes a base class.
-        ArraySize = 0;
-        IsArray = false;
-      }
-    }
-    return MostDerivedLength;
-  }
-
-  // The order of this enum is important for diagnostics.
-  enum CheckSubobjectKind {
-    CSK_Base, CSK_Derived, CSK_Field, CSK_ArrayToPointer, CSK_ArrayIndex,
-    CSK_This, CSK_Real, CSK_Imag
-  };
-
-  /// A path from a glvalue to a subobject of that glvalue.
-  struct SubobjectDesignator {
-    /// True if the subobject was named in a manner not supported by C++11. Such
-    /// lvalues can still be folded, but they are not core constant expressions
-    /// and we cannot perform lvalue-to-rvalue conversions on them.
-    unsigned Invalid : 1;
-
-    /// Is this a pointer one past the end of an object?
-    unsigned IsOnePastTheEnd : 1;
-
-    /// Indicator of whether the first entry is an unsized array.
-    unsigned FirstEntryIsAnUnsizedArray : 1;
-
-    /// Indicator of whether the most-derived object is an array element.
-    unsigned MostDerivedIsArrayElement : 1;
-
-    /// The length of the path to the most-derived object of which this is a
-    /// subobject.
-    unsigned MostDerivedPathLength : 28;
-
-    /// The size of the array of which the most-derived object is an element.
-    /// This will always be 0 if the most-derived object is not an array
-    /// element. 0 is not an indicator of whether or not the most-derived object
-    /// is an array, however, because 0-length arrays are allowed.
-    ///
-    /// If the current array is an unsized array, the value of this is
-    /// undefined.
-    uint64_t MostDerivedArraySize;
-
-    /// The type of the most derived object referred to by this address.
-    QualType MostDerivedType;
-
-    typedef APValue::LValuePathEntry PathEntry;
-
-    /// The entries on the path from the glvalue to the designated subobject.
-    SmallVector<PathEntry, 8> Entries;
-
-    SubobjectDesignator() : Invalid(true) {}
-
-    explicit SubobjectDesignator(QualType T)
-        : Invalid(false), IsOnePastTheEnd(false),
-          FirstEntryIsAnUnsizedArray(false), MostDerivedIsArrayElement(false),
-          MostDerivedPathLength(0), MostDerivedArraySize(0),
-          MostDerivedType(T) {}
-
-    SubobjectDesignator(ASTContext &Ctx, const APValue &V)
-        : Invalid(!V.isLValue() || !V.hasLValuePath()), IsOnePastTheEnd(false),
-          FirstEntryIsAnUnsizedArray(false), MostDerivedIsArrayElement(false),
-          MostDerivedPathLength(0), MostDerivedArraySize(0) {
-      assert(V.isLValue() && "Non-LValue used to make an LValue designator?");
-      if (!Invalid) {
-        IsOnePastTheEnd = V.isLValueOnePastTheEnd();
-        ArrayRef<PathEntry> VEntries = V.getLValuePath();
-        Entries.insert(Entries.end(), VEntries.begin(), VEntries.end());
-        if (V.getLValueBase()) {
-          bool IsArray = false;
-          bool FirstIsUnsizedArray = false;
-          MostDerivedPathLength = findMostDerivedSubobject(
-              Ctx, V.getLValueBase(), V.getLValuePath(), MostDerivedArraySize,
-              MostDerivedType, IsArray, FirstIsUnsizedArray);
-          MostDerivedIsArrayElement = IsArray;
-          FirstEntryIsAnUnsizedArray = FirstIsUnsizedArray;
-        }
-      }
-    }
-
-    void setInvalid() {
-      Invalid = true;
-      Entries.clear();
-    }
-
-    /// Determine whether the most derived subobject is an array without a
-    /// known bound.
-    bool isMostDerivedAnUnsizedArray() const {
-      assert(!Invalid && "Calling this makes no sense on invalid designators");
-      return Entries.size() == 1 && FirstEntryIsAnUnsizedArray;
-    }
-
-    /// Determine what the most derived array's size is. Results in an assertion
-    /// failure if the most derived array lacks a size.
-    uint64_t getMostDerivedArraySize() const {
-      assert(!isMostDerivedAnUnsizedArray() && "Unsized array has no size");
-      return MostDerivedArraySize;
-    }
-
-    /// Determine whether this is a one-past-the-end pointer.
-    bool isOnePastTheEnd() const {
-      assert(!Invalid);
-      if (IsOnePastTheEnd)
-        return true;
-      if (!isMostDerivedAnUnsizedArray() && MostDerivedIsArrayElement &&
-          Entries[MostDerivedPathLength - 1].ArrayIndex == MostDerivedArraySize)
-        return true;
-      return false;
-    }
-
-    /// Get the range of valid index adjustments in the form
-    ///   {maximum value that can be subtracted from this pointer,
-    ///    maximum value that can be added to this pointer}
-    std::pair<uint64_t, uint64_t> validIndexAdjustments() {
-      if (Invalid || isMostDerivedAnUnsizedArray())
-        return {0, 0};
-
-      // [expr.add]p4: For the purposes of these operators, a pointer to a
-      // nonarray object behaves the same as a pointer to the first element of
-      // an array of length one with the type of the object as its element type.
-      bool IsArray = MostDerivedPathLength == Entries.size() &&
-                     MostDerivedIsArrayElement;
-      uint64_t ArrayIndex =
-          IsArray ? Entries.back().ArrayIndex : (uint64_t)IsOnePastTheEnd;
-      uint64_t ArraySize =
-          IsArray ? getMostDerivedArraySize() : (uint64_t)1;
-      return {ArrayIndex, ArraySize - ArrayIndex};
-    }
-
-    /// Check that this refers to a valid subobject.
-    bool isValidSubobject() const {
-      if (Invalid)
-        return false;
-      return !isOnePastTheEnd();
-    }
-    /// Check that this refers to a valid subobject, and if not, produce a
-    /// relevant diagnostic and set the designator as invalid.
-    bool checkSubobject(EvalInfo &Info, const Expr *E, CheckSubobjectKind CSK);
-
-    /// Get the type of the designated object.
-    QualType getType(ASTContext &Ctx) const {
-      assert(!Invalid && "invalid designator has no subobject type");
-      return MostDerivedPathLength == Entries.size()
-                 ? MostDerivedType
-                 : Ctx.getRecordType(getAsBaseClass(Entries.back()));
-    }
-
-    /// Update this designator to refer to the first element within this array.
-    void addArrayUnchecked(const ConstantArrayType *CAT) {
-      PathEntry Entry;
-      Entry.ArrayIndex = 0;
-      Entries.push_back(Entry);
-
-      // This is a most-derived object.
-      MostDerivedType = CAT->getElementType();
-      MostDerivedIsArrayElement = true;
-      MostDerivedArraySize = CAT->getSize().getZExtValue();
-      MostDerivedPathLength = Entries.size();
-    }
-    /// Update this designator to refer to the first element within the array of
-    /// elements of type T. This is an array of unknown size.
-    void addUnsizedArrayUnchecked(QualType ElemTy) {
-      PathEntry Entry;
-      Entry.ArrayIndex = 0;
-      Entries.push_back(Entry);
-
-      MostDerivedType = ElemTy;
-      MostDerivedIsArrayElement = true;
-      // The value in MostDerivedArraySize is undefined in this case. So, set it
-      // to an arbitrary value that's likely to loudly break things if it's
-      // used.
-      MostDerivedArraySize = AssumedSizeForUnsizedArray;
-      MostDerivedPathLength = Entries.size();
-    }
-    /// Update this designator to refer to the given base or member of this
-    /// object.
-    void addDeclUnchecked(const Decl *D, bool Virtual = false) {
-      PathEntry Entry;
-      APValue::BaseOrMemberType Value(D, Virtual);
-      Entry.BaseOrMember = Value.getOpaqueValue();
-      Entries.push_back(Entry);
-
-      // If this isn't a base class, it's a new most-derived object.
-      if (const FieldDecl *FD = dyn_cast<FieldDecl>(D)) {
-        MostDerivedType = FD->getType();
-        MostDerivedIsArrayElement = false;
-        MostDerivedArraySize = 0;
-        MostDerivedPathLength = Entries.size();
-      }
-    }
-    /// Update this designator to refer to the given complex component.
-    void addComplexUnchecked(QualType EltTy, bool Imag) {
-      PathEntry Entry;
-      Entry.ArrayIndex = Imag;
-      Entries.push_back(Entry);
-
-      // This is technically a most-derived object, though in practice this
-      // is unlikely to matter.
-      MostDerivedType = EltTy;
-      MostDerivedIsArrayElement = true;
-      MostDerivedArraySize = 2;
-      MostDerivedPathLength = Entries.size();
-    }
-    void diagnoseUnsizedArrayPointerArithmetic(EvalInfo &Info, const Expr *E);
-    void diagnosePointerArithmetic(EvalInfo &Info, const Expr *E,
-                                   const APSInt &N);
-    /// Add N to the address of this subobject.
-    void adjustIndex(EvalInfo &Info, const Expr *E, APSInt N) {
-      if (Invalid || !N) return;
-      uint64_t TruncatedN = N.extOrTrunc(64).getZExtValue();
-      if (isMostDerivedAnUnsizedArray()) {
-        diagnoseUnsizedArrayPointerArithmetic(Info, E);
-        // Can't verify -- trust that the user is doing the right thing (or if
-        // not, trust that the caller will catch the bad behavior).
-        // FIXME: Should we reject if this overflows, at least?
-        Entries.back().ArrayIndex += TruncatedN;
-        return;
-      }
-
-      // [expr.add]p4: For the purposes of these operators, a pointer to a
-      // nonarray object behaves the same as a pointer to the first element of
-      // an array of length one with the type of the object as its element type.
-      bool IsArray = MostDerivedPathLength == Entries.size() &&
-                     MostDerivedIsArrayElement;
-      uint64_t ArrayIndex =
-          IsArray ? Entries.back().ArrayIndex : (uint64_t)IsOnePastTheEnd;
-      uint64_t ArraySize =
-          IsArray ? getMostDerivedArraySize() : (uint64_t)1;
-
-      if (N < -(int64_t)ArrayIndex || N > ArraySize - ArrayIndex) {
-        // Calculate the actual index in a wide enough type, so we can include
-        // it in the note.
-        N = N.extend(std::max<unsigned>(N.getBitWidth() + 1, 65));
-        (llvm::APInt&)N += ArrayIndex;
-        assert(N.ugt(ArraySize) && "bounds check failed for in-bounds index");
-        diagnosePointerArithmetic(Info, E, N);
-        setInvalid();
-        return;
-      }
-
-      ArrayIndex += TruncatedN;
-      assert(ArrayIndex <= ArraySize &&
-             "bounds check succeeded for out-of-bounds index");
-
-      if (IsArray)
-        Entries.back().ArrayIndex = ArrayIndex;
-      else
-        IsOnePastTheEnd = (ArrayIndex != 0);
-    }
-  };
-
-  /// A stack frame in the constexpr call stack.
-  struct CallStackFrame {
-    EvalInfo &Info;
-
-    /// Parent - The caller of this stack frame.
-    CallStackFrame *Caller;
-
-    /// Callee - The function which was called.
-    const FunctionDecl *Callee;
-
-    /// This - The binding for the this pointer in this call, if any.
-    const LValue *This;
-
-    /// Arguments - Parameter bindings for this function call, indexed by
-    /// parameters' function scope indices.
-    APValue *Arguments;
-
-    // Note that we intentionally use std::map here so that references to
-    // values are stable.
-    typedef std::pair<const void *, unsigned> MapKeyTy;
-    typedef std::map<MapKeyTy, APValue> MapTy;
-    /// Temporaries - Temporary lvalues materialized within this stack frame.
-    MapTy Temporaries;
-
-    /// CallLoc - The location of the call expression for this call.
-    SourceLocation CallLoc;
-
-    /// Index - The call index of this call.
-    unsigned Index;
-
-    /// The stack of integers for tracking version numbers for temporaries.
-    SmallVector<unsigned, 2> TempVersionStack = {1};
-    unsigned CurTempVersion = TempVersionStack.back();
-
-    unsigned getTempVersion() const { return TempVersionStack.back(); }
-
-    void pushTempVersion() {
-      TempVersionStack.push_back(++CurTempVersion);
-    }
-
-    void popTempVersion() {
-      TempVersionStack.pop_back();
-    }
-
-    // FIXME: Adding this to every 'CallStackFrame' may have a nontrivial impact
-    // on the overall stack usage of deeply-recursing constexpr evaluations.
-    // (We should cache this map rather than recomputing it repeatedly.)
-    // But let's try this and see how it goes; we can look into caching the map
-    // as a later change.
-
-    /// LambdaCaptureFields - Mapping from captured variables/this to
-    /// corresponding data members in the closure class.
-    llvm::DenseMap<const VarDecl *, FieldDecl *> LambdaCaptureFields;
-    FieldDecl *LambdaThisCaptureField;
-
-    CallStackFrame(EvalInfo &Info, SourceLocation CallLoc,
-                   const FunctionDecl *Callee, const LValue *This,
-                   APValue *Arguments);
-    ~CallStackFrame();
-
-    // Return the temporary for Key whose version number is Version.
-    APValue *getTemporary(const void *Key, unsigned Version) {
-      MapKeyTy KV(Key, Version);
-      auto LB = Temporaries.lower_bound(KV);
-      if (LB != Temporaries.end() && LB->first == KV)
-        return &LB->second;
-      // Pair (Key,Version) wasn't found in the map. Check that no elements
-      // in the map have 'Key' as their key.
-      assert((LB == Temporaries.end() || LB->first.first != Key) &&
-             (LB == Temporaries.begin() || std::prev(LB)->first.first != Key) &&
-             "Element with key 'Key' found in map");
-      return nullptr;
-    }
-
-    // Return the current temporary for Key in the map.
-    APValue *getCurrentTemporary(const void *Key) {
-      auto UB = Temporaries.upper_bound(MapKeyTy(Key, UINT_MAX));
-      if (UB != Temporaries.begin() && std::prev(UB)->first.first == Key)
-        return &std::prev(UB)->second;
-      return nullptr;
-    }
-
-    // Return the version number of the current temporary for Key.
-    unsigned getCurrentTemporaryVersion(const void *Key) const {
-      auto UB = Temporaries.upper_bound(MapKeyTy(Key, UINT_MAX));
-      if (UB != Temporaries.begin() && std::prev(UB)->first.first == Key)
-        return std::prev(UB)->first.second;
-      return 0;
-    }
-
-    APValue &createTemporary(const void *Key, bool IsLifetimeExtended);
-  };
-
-  /// Temporarily override 'this'.
-  class ThisOverrideRAII {
-  public:
-    ThisOverrideRAII(CallStackFrame &Frame, const LValue *NewThis, bool Enable)
-        : Frame(Frame), OldThis(Frame.This) {
-      if (Enable)
-        Frame.This = NewThis;
-    }
-    ~ThisOverrideRAII() {
-      Frame.This = OldThis;
-    }
-  private:
-    CallStackFrame &Frame;
-    const LValue *OldThis;
-  };
-
-  /// A partial diagnostic which we might know in advance that we are not going
-  /// to emit.
-  class OptionalDiagnostic {
-    PartialDiagnostic *Diag;
-
-  public:
-    explicit OptionalDiagnostic(PartialDiagnostic *Diag = nullptr)
-      : Diag(Diag) {}
-
-    template<typename T>
-    OptionalDiagnostic &operator<<(const T &v) {
-      if (Diag)
-        *Diag << v;
-      return *this;
-    }
-
-    OptionalDiagnostic &operator<<(const APSInt &I) {
-      if (Diag) {
-        SmallVector<char, 32> Buffer;
-        I.toString(Buffer);
-        *Diag << StringRef(Buffer.data(), Buffer.size());
-      }
-      return *this;
-    }
-
-    OptionalDiagnostic &operator<<(const APFloat &F) {
-      if (Diag) {
-        // FIXME: Force the precision of the source value down so we don't
-        // print digits which are usually useless (we don't really care here if
-        // we truncate a digit by accident in edge cases).  Ideally,
-        // APFloat::toString would automatically print the shortest
-        // representation which rounds to the correct value, but it's a bit
-        // tricky to implement.
-        unsigned precision =
-            llvm::APFloat::semanticsPrecision(F.getSemantics());
-        precision = (precision * 59 + 195) / 196;
-        SmallVector<char, 32> Buffer;
-        F.toString(Buffer, precision);
-        *Diag << StringRef(Buffer.data(), Buffer.size());
-      }
-      return *this;
-    }
-  };
-
-  /// A cleanup, and a flag indicating whether it is lifetime-extended.
-  class Cleanup {
-    llvm::PointerIntPair<APValue*, 1, bool> Value;
-
-  public:
-    Cleanup(APValue *Val, bool IsLifetimeExtended)
-        : Value(Val, IsLifetimeExtended) {}
-
-    bool isLifetimeExtended() const { return Value.getInt(); }
-    void endLifetime() {
-      *Value.getPointer() = APValue();
-    }
-  };
-
-  /// EvalInfo - This is a private struct used by the evaluator to capture
-  /// information about a subexpression as it is folded.  It retains information
-  /// about the AST context, but also maintains information about the folded
-  /// expression.
-  ///
-  /// If an expression could be evaluated, it is still possible it is not a C
-  /// "integer constant expression" or constant expression.  If not, this struct
-  /// captures information about how and why not.
-  ///
-  /// One bit of information passed *into* the request for constant folding
-  /// indicates whether the subexpression is "evaluated" or not according to C
-  /// rules.  For example, the RHS of (0 && foo()) is not evaluated.  We can
-  /// evaluate the expression regardless of what the RHS is, but C only allows
-  /// certain things in certain situations.
-  struct EvalInfo {
-    ASTContext &Ctx;
-
-    /// EvalStatus - Contains information about the evaluation.
-    Expr::EvalStatus &EvalStatus;
-
-    /// CurrentCall - The top of the constexpr call stack.
-    CallStackFrame *CurrentCall;
-
-    /// CallStackDepth - The number of calls in the call stack right now.
-    unsigned CallStackDepth;
-
-    /// NextCallIndex - The next call index to assign.
-    unsigned NextCallIndex;
-
-    /// StepsLeft - The remaining number of evaluation steps we're permitted
-    /// to perform. This is essentially a limit for the number of statements
-    /// we will evaluate.
-    unsigned StepsLeft;
-
-    /// BottomFrame - The frame in which evaluation started. This must be
-    /// initialized after CurrentCall and CallStackDepth.
-    CallStackFrame BottomFrame;
-
-    /// A stack of values whose lifetimes end at the end of some surrounding
-    /// evaluation frame.
-    llvm::SmallVector<Cleanup, 16> CleanupStack;
-
-    /// EvaluatingDecl - This is the declaration whose initializer is being
-    /// evaluated, if any.
-    APValue::LValueBase EvaluatingDecl;
-
-    /// EvaluatingDeclValue - This is the value being constructed for the
-    /// declaration whose initializer is being evaluated, if any.
-    APValue *EvaluatingDeclValue;
-
-    /// EvaluatingObject - Pair of the AST node that an lvalue represents and
-    /// the call index that that lvalue was allocated in.
-    typedef std::pair<APValue::LValueBase, std::pair<unsigned, unsigned>>
-        EvaluatingObject;
-
-    /// EvaluatingConstructors - Set of objects that are currently being
-    /// constructed.
-    llvm::DenseSet<EvaluatingObject> EvaluatingConstructors;
-
-    struct EvaluatingConstructorRAII {
-      EvalInfo &EI;
-      EvaluatingObject Object;
-      bool DidInsert;
-      EvaluatingConstructorRAII(EvalInfo &EI, EvaluatingObject Object)
-          : EI(EI), Object(Object) {
-        DidInsert = EI.EvaluatingConstructors.insert(Object).second;
-      }
-      ~EvaluatingConstructorRAII() {
-        if (DidInsert) EI.EvaluatingConstructors.erase(Object);
-      }
-    };
-
-    bool isEvaluatingConstructor(APValue::LValueBase Decl, unsigned CallIndex,
-                                 unsigned Version) {
-      return EvaluatingConstructors.count(
-          EvaluatingObject(Decl, {CallIndex, Version}));
-    }
-
-    /// The current array initialization index, if we're performing array
-    /// initialization.
-    uint64_t ArrayInitIndex = -1;
-
-    /// HasActiveDiagnostic - Was the previous diagnostic stored? If so, further
-    /// notes attached to it will also be stored, otherwise they will not be.
-    bool HasActiveDiagnostic;
-
-    /// Have we emitted a diagnostic explaining why we couldn't constant
-    /// fold (not just why it's not strictly a constant expression)?
-    bool HasFoldFailureDiagnostic;
-
-    /// Whether or not we're currently speculatively evaluating.
-    bool IsSpeculativelyEvaluating;
-
-    /// Whether or not we're in a context where the front end requires a
-    /// constant value.
-    bool InConstantContext;
-
-    enum EvaluationMode {
-      /// Evaluate as a constant expression. Stop if we find that the expression
-      /// is not a constant expression.
-      EM_ConstantExpression,
-
-      /// Evaluate as a potential constant expression. Keep going if we hit a
-      /// construct that we can't evaluate yet (because we don't yet know the
-      /// value of something) but stop if we hit something that could never be
-      /// a constant expression.
-      EM_PotentialConstantExpression,
-
-      /// Fold the expression to a constant. Stop if we hit a side-effect that
-      /// we can't model.
-      EM_ConstantFold,
-
-      /// Evaluate the expression looking for integer overflow and similar
-      /// issues. Don't worry about side-effects, and try to visit all
-      /// subexpressions.
-      EM_EvaluateForOverflow,
-
-      /// Evaluate in any way we know how. Don't worry about side-effects that
-      /// can't be modeled.
-      EM_IgnoreSideEffects,
-
-      /// Evaluate as a constant expression. Stop if we find that the expression
-      /// is not a constant expression. Some expressions can be retried in the
-      /// optimizer if we don't constant fold them here, but in an unevaluated
-      /// context we try to fold them immediately since the optimizer never
-      /// gets a chance to look at it.
-      EM_ConstantExpressionUnevaluated,
-
-      /// Evaluate as a potential constant expression. Keep going if we hit a
-      /// construct that we can't evaluate yet (because we don't yet know the
-      /// value of something) but stop if we hit something that could never be
-      /// a constant expression. Some expressions can be retried in the
-      /// optimizer if we don't constant fold them here, but in an unevaluated
-      /// context we try to fold them immediately since the optimizer never
-      /// gets a chance to look at it.
-      EM_PotentialConstantExpressionUnevaluated,
-    } EvalMode;
-
-    /// Are we checking whether the expression is a potential constant
-    /// expression?
-    bool checkingPotentialConstantExpression() const {
-      return EvalMode == EM_PotentialConstantExpression ||
-             EvalMode == EM_PotentialConstantExpressionUnevaluated;
-    }
-
-    /// Are we checking an expression for overflow?
-    // FIXME: We should check for any kind of undefined or suspicious behavior
-    // in such constructs, not just overflow.
-    bool checkingForOverflow() { return EvalMode == EM_EvaluateForOverflow; }
-
-    EvalInfo(const ASTContext &C, Expr::EvalStatus &S, EvaluationMode Mode)
-      : Ctx(const_cast<ASTContext &>(C)), EvalStatus(S), CurrentCall(nullptr),
-        CallStackDepth(0), NextCallIndex(1),
-        StepsLeft(getLangOpts().ConstexprStepLimit),
-        BottomFrame(*this, SourceLocation(), nullptr, nullptr, nullptr),
-        EvaluatingDecl((const ValueDecl *)nullptr),
-        EvaluatingDeclValue(nullptr), HasActiveDiagnostic(false),
-        HasFoldFailureDiagnostic(false), IsSpeculativelyEvaluating(false),
-        InConstantContext(false), EvalMode(Mode) {}
-
-    void setEvaluatingDecl(APValue::LValueBase Base, APValue &Value) {
-      EvaluatingDecl = Base;
-      EvaluatingDeclValue = &Value;
-      EvaluatingConstructors.insert({Base, {0, 0}});
-    }
-
-    const LangOptions &getLangOpts() const { return Ctx.getLangOpts(); }
-
-    bool CheckCallLimit(SourceLocation Loc) {
-      // Don't perform any constexpr calls (other than the call we're checking)
-      // when checking a potential constant expression.
-      if (checkingPotentialConstantExpression() && CallStackDepth > 1)
-        return false;
-      if (NextCallIndex == 0) {
-        // NextCallIndex has wrapped around.
-        FFDiag(Loc, diag::note_constexpr_call_limit_exceeded);
-        return false;
-      }
-      if (CallStackDepth <= getLangOpts().ConstexprCallDepth)
-        return true;
-      FFDiag(Loc, diag::note_constexpr_depth_limit_exceeded)
-        << getLangOpts().ConstexprCallDepth;
-      return false;
-    }
-
-    CallStackFrame *getCallFrame(unsigned CallIndex) {
-      assert(CallIndex && "no call index in getCallFrame");
-      // We will eventually hit BottomFrame, which has Index 1, so Frame can't
-      // be null in this loop.
-      CallStackFrame *Frame = CurrentCall;
-      while (Frame->Index > CallIndex)
-        Frame = Frame->Caller;
-      return (Frame->Index == CallIndex) ? Frame : nullptr;
-    }
-
-    bool nextStep(const Stmt *S) {
-      if (!StepsLeft) {
-        FFDiag(S->getBeginLoc(), diag::note_constexpr_step_limit_exceeded);
-        return false;
-      }
-      --StepsLeft;
-      return true;
-    }
-
-  private:
-    /// Add a diagnostic to the diagnostics list.
-    PartialDiagnostic &addDiag(SourceLocation Loc, diag::kind DiagId) {
-      PartialDiagnostic PD(DiagId, Ctx.getDiagAllocator());
-      EvalStatus.Diag->push_back(std::make_pair(Loc, PD));
-      return EvalStatus.Diag->back().second;
-    }
-
-    /// Add notes containing a call stack to the current point of evaluation.
-    void addCallStack(unsigned Limit);
-
-  private:
-    OptionalDiagnostic Diag(SourceLocation Loc, diag::kind DiagId,
-                            unsigned ExtraNotes, bool IsCCEDiag) {
-
-      if (EvalStatus.Diag) {
-        // If we have a prior diagnostic, it will be noting that the expression
-        // isn't a constant expression. This diagnostic is more important,
-        // unless we require this evaluation to produce a constant expression.
-        //
-        // FIXME: We might want to show both diagnostics to the user in
-        // EM_ConstantFold mode.
-        if (!EvalStatus.Diag->empty()) {
-          switch (EvalMode) {
-          case EM_ConstantFold:
-          case EM_IgnoreSideEffects:
-          case EM_EvaluateForOverflow:
-            if (!HasFoldFailureDiagnostic)
-              break;
-            // We've already failed to fold something. Keep that diagnostic.
-            LLVM_FALLTHROUGH;
-          case EM_ConstantExpression:
-          case EM_PotentialConstantExpression:
-          case EM_ConstantExpressionUnevaluated:
-          case EM_PotentialConstantExpressionUnevaluated:
-            HasActiveDiagnostic = false;
-            return OptionalDiagnostic();
-          }
-        }
-
-        unsigned CallStackNotes = CallStackDepth - 1;
-        unsigned Limit = Ctx.getDiagnostics().getConstexprBacktraceLimit();
-        if (Limit)
-          CallStackNotes = std::min(CallStackNotes, Limit + 1);
-        if (checkingPotentialConstantExpression())
-          CallStackNotes = 0;
-
-        HasActiveDiagnostic = true;
-        HasFoldFailureDiagnostic = !IsCCEDiag;
-        EvalStatus.Diag->clear();
-        EvalStatus.Diag->reserve(1 + ExtraNotes + CallStackNotes);
-        addDiag(Loc, DiagId);
-        if (!checkingPotentialConstantExpression())
-          addCallStack(Limit);
-        return OptionalDiagnostic(&(*EvalStatus.Diag)[0].second);
-      }
-      HasActiveDiagnostic = false;
-      return OptionalDiagnostic();
-    }
-  public:
-    // Diagnose that the evaluation could not be folded (FF => FoldFailure)
-    OptionalDiagnostic
-    FFDiag(SourceLocation Loc,
-          diag::kind DiagId = diag::note_invalid_subexpr_in_const_expr,
-          unsigned ExtraNotes = 0) {
-      return Diag(Loc, DiagId, ExtraNotes, false);
-    }
-
-    OptionalDiagnostic FFDiag(const Expr *E, diag::kind DiagId
-                              = diag::note_invalid_subexpr_in_const_expr,
-                            unsigned ExtraNotes = 0) {
-      if (EvalStatus.Diag)
-        return Diag(E->getExprLoc(), DiagId, ExtraNotes, /*IsCCEDiag*/false);
-      HasActiveDiagnostic = false;
-      return OptionalDiagnostic();
-    }
-
-    /// Diagnose that the evaluation does not produce a C++11 core constant
-    /// expression.
-    ///
-    /// FIXME: Stop evaluating if we're in EM_ConstantExpression or
-    /// EM_PotentialConstantExpression mode and we produce one of these.
-    OptionalDiagnostic CCEDiag(SourceLocation Loc, diag::kind DiagId
-                                 = diag::note_invalid_subexpr_in_const_expr,
-                               unsigned ExtraNotes = 0) {
-      // Don't override a previous diagnostic. Don't bother collecting
-      // diagnostics if we're evaluating for overflow.
-      if (!EvalStatus.Diag || !EvalStatus.Diag->empty()) {
-        HasActiveDiagnostic = false;
-        return OptionalDiagnostic();
-      }
-      return Diag(Loc, DiagId, ExtraNotes, true);
-    }
-    OptionalDiagnostic CCEDiag(const Expr *E, diag::kind DiagId
-                                 = diag::note_invalid_subexpr_in_const_expr,
-                               unsigned ExtraNotes = 0) {
-      return CCEDiag(E->getExprLoc(), DiagId, ExtraNotes);
-    }
-    /// Add a note to a prior diagnostic.
-    OptionalDiagnostic Note(SourceLocation Loc, diag::kind DiagId) {
-      if (!HasActiveDiagnostic)
-        return OptionalDiagnostic();
-      return OptionalDiagnostic(&addDiag(Loc, DiagId));
-    }
-
-    /// Add a stack of notes to a prior diagnostic.
-    void addNotes(ArrayRef<PartialDiagnosticAt> Diags) {
-      if (HasActiveDiagnostic) {
-        EvalStatus.Diag->insert(EvalStatus.Diag->end(),
-                                Diags.begin(), Diags.end());
-      }
-    }
-
-    /// Should we continue evaluation after encountering a side-effect that we
-    /// couldn't model?
-    bool keepEvaluatingAfterSideEffect() {
-      switch (EvalMode) {
-      case EM_PotentialConstantExpression:
-      case EM_PotentialConstantExpressionUnevaluated:
-      case EM_EvaluateForOverflow:
-      case EM_IgnoreSideEffects:
-        return true;
-
-      case EM_ConstantExpression:
-      case EM_ConstantExpressionUnevaluated:
-      case EM_ConstantFold:
-        return false;
-      }
-      llvm_unreachable("Missed EvalMode case");
-    }
-
-    /// Note that we have had a side-effect, and determine whether we should
-    /// keep evaluating.
-    bool noteSideEffect() {
-      EvalStatus.HasSideEffects = true;
-      return keepEvaluatingAfterSideEffect();
-    }
-
-    /// Should we continue evaluation after encountering undefined behavior?
-    bool keepEvaluatingAfterUndefinedBehavior() {
-      switch (EvalMode) {
-      case EM_EvaluateForOverflow:
-      case EM_IgnoreSideEffects:
-      case EM_ConstantFold:
-        return true;
-
-      case EM_PotentialConstantExpression:
-      case EM_PotentialConstantExpressionUnevaluated:
-      case EM_ConstantExpression:
-      case EM_ConstantExpressionUnevaluated:
-        return false;
-      }
-      llvm_unreachable("Missed EvalMode case");
-    }
-
-    /// Note that we hit something that was technically undefined behavior, but
-    /// that we can evaluate past it (such as signed overflow or floating-point
-    /// division by zero.)
-    bool noteUndefinedBehavior() {
-      EvalStatus.HasUndefinedBehavior = true;
-      return keepEvaluatingAfterUndefinedBehavior();
-    }
-
-    /// Should we continue evaluation as much as possible after encountering a
-    /// construct which can't be reduced to a value?
-    bool keepEvaluatingAfterFailure() {
-      if (!StepsLeft)
-        return false;
-
-      switch (EvalMode) {
-      case EM_PotentialConstantExpression:
-      case EM_PotentialConstantExpressionUnevaluated:
-      case EM_EvaluateForOverflow:
-        return true;
-
-      case EM_ConstantExpression:
-      case EM_ConstantExpressionUnevaluated:
-      case EM_ConstantFold:
-      case EM_IgnoreSideEffects:
-        return false;
-      }
-      llvm_unreachable("Missed EvalMode case");
-    }
-
-    /// Notes that we failed to evaluate an expression that other expressions
-    /// directly depend on, and determine if we should keep evaluating. This
-    /// should only be called if we actually intend to keep evaluating.
-    ///
-    /// Call noteSideEffect() instead if we may be able to ignore the value that
-    /// we failed to evaluate, e.g. if we failed to evaluate Foo() in:
-    ///
-    /// (Foo(), 1)      // use noteSideEffect
-    /// (Foo() || true) // use noteSideEffect
-    /// Foo() + 1       // use noteFailure
-    LLVM_NODISCARD bool noteFailure() {
-      // Failure when evaluating some expression often means there is some
-      // subexpression whose evaluation was skipped. Therefore, (because we
-      // don't track whether we skipped an expression when unwinding after an
-      // evaluation failure) every evaluation failure that bubbles up from a
-      // subexpression implies that a side-effect has potentially happened. We
-      // skip setting the HasSideEffects flag to true until we decide to
-      // continue evaluating after that point, which happens here.
-      bool KeepGoing = keepEvaluatingAfterFailure();
-      EvalStatus.HasSideEffects |= KeepGoing;
-      return KeepGoing;
-    }
-
-    class ArrayInitLoopIndex {
-      EvalInfo &Info;
-      uint64_t OuterIndex;
-
-    public:
-      ArrayInitLoopIndex(EvalInfo &Info)
-          : Info(Info), OuterIndex(Info.ArrayInitIndex) {
-        Info.ArrayInitIndex = 0;
-      }
-      ~ArrayInitLoopIndex() { Info.ArrayInitIndex = OuterIndex; }
-
-      operator uint64_t&() { return Info.ArrayInitIndex; }
-    };
-  };
-
-  /// Object used to treat all foldable expressions as constant expressions.
-  struct FoldConstant {
-    EvalInfo &Info;
-    bool Enabled;
-    bool HadNoPriorDiags;
-    EvalInfo::EvaluationMode OldMode;
-
-    explicit FoldConstant(EvalInfo &Info, bool Enabled)
-      : Info(Info),
-        Enabled(Enabled),
-        HadNoPriorDiags(Info.EvalStatus.Diag &&
-                        Info.EvalStatus.Diag->empty() &&
-                        !Info.EvalStatus.HasSideEffects),
-        OldMode(Info.EvalMode) {
-      if (Enabled &&
-          (Info.EvalMode == EvalInfo::EM_ConstantExpression ||
-           Info.EvalMode == EvalInfo::EM_ConstantExpressionUnevaluated))
-        Info.EvalMode = EvalInfo::EM_ConstantFold;
-    }
-    void keepDiagnostics() { Enabled = false; }
-    ~FoldConstant() {
-      if (Enabled && HadNoPriorDiags && !Info.EvalStatus.Diag->empty() &&
-          !Info.EvalStatus.HasSideEffects)
-        Info.EvalStatus.Diag->clear();
-      Info.EvalMode = OldMode;
-    }
-  };
-
-  /// RAII object used to set the current evaluation mode to ignore
-  /// side-effects.
-  struct IgnoreSideEffectsRAII {
-    EvalInfo &Info;
-    EvalInfo::EvaluationMode OldMode;
-    explicit IgnoreSideEffectsRAII(EvalInfo &Info)
-        : Info(Info), OldMode(Info.EvalMode) {
-      if (!Info.checkingPotentialConstantExpression())
-        Info.EvalMode = EvalInfo::EM_IgnoreSideEffects;
-    }
-
-    ~IgnoreSideEffectsRAII() { Info.EvalMode = OldMode; }
-  };
-
-  /// RAII object used to optionally suppress diagnostics and side-effects from
-  /// a speculative evaluation.
-  class SpeculativeEvaluationRAII {
-    EvalInfo *Info = nullptr;
-    Expr::EvalStatus OldStatus;
-    bool OldIsSpeculativelyEvaluating;
-
-    void moveFromAndCancel(SpeculativeEvaluationRAII &&Other) {
-      Info = Other.Info;
-      OldStatus = Other.OldStatus;
-      OldIsSpeculativelyEvaluating = Other.OldIsSpeculativelyEvaluating;
-      Other.Info = nullptr;
-    }
-
-    void maybeRestoreState() {
-      if (!Info)
-        return;
-
-      Info->EvalStatus = OldStatus;
-      Info->IsSpeculativelyEvaluating = OldIsSpeculativelyEvaluating;
-    }
-
-  public:
-    SpeculativeEvaluationRAII() = default;
-
-    SpeculativeEvaluationRAII(
-        EvalInfo &Info, SmallVectorImpl<PartialDiagnosticAt> *NewDiag = nullptr)
-        : Info(&Info), OldStatus(Info.EvalStatus),
-          OldIsSpeculativelyEvaluating(Info.IsSpeculativelyEvaluating) {
-      Info.EvalStatus.Diag = NewDiag;
-      Info.IsSpeculativelyEvaluating = true;
-    }
-
-    SpeculativeEvaluationRAII(const SpeculativeEvaluationRAII &Other) = delete;
-    SpeculativeEvaluationRAII(SpeculativeEvaluationRAII &&Other) {
-      moveFromAndCancel(std::move(Other));
-    }
-
-    SpeculativeEvaluationRAII &operator=(SpeculativeEvaluationRAII &&Other) {
-      maybeRestoreState();
-      moveFromAndCancel(std::move(Other));
-      return *this;
-    }
-
-    ~SpeculativeEvaluationRAII() { maybeRestoreState(); }
-  };
-
-  /// RAII object wrapping a full-expression or block scope, and handling
-  /// the ending of the lifetime of temporaries created within it.
-  template<bool IsFullExpression>
-  class ScopeRAII {
-    EvalInfo &Info;
-    unsigned OldStackSize;
-  public:
-    ScopeRAII(EvalInfo &Info)
-        : Info(Info), OldStackSize(Info.CleanupStack.size()) {
-      // Push a new temporary version. This is needed to distinguish between
-      // temporaries created in different iterations of a loop.
-      Info.CurrentCall->pushTempVersion();
-    }
-    ~ScopeRAII() {
-      // Body moved to a static method to encourage the compiler to inline away
-      // instances of this class.
-      cleanup(Info, OldStackSize);
-      Info.CurrentCall->popTempVersion();
-    }
-  private:
-    static void cleanup(EvalInfo &Info, unsigned OldStackSize) {
-      unsigned NewEnd = OldStackSize;
-      for (unsigned I = OldStackSize, N = Info.CleanupStack.size();
-           I != N; ++I) {
-        if (IsFullExpression && Info.CleanupStack[I].isLifetimeExtended()) {
-          // Full-expression cleanup of a lifetime-extended temporary: nothing
-          // to do, just move this cleanup to the right place in the stack.
-          std::swap(Info.CleanupStack[I], Info.CleanupStack[NewEnd]);
-          ++NewEnd;
-        } else {
-          // End the lifetime of the object.
-          Info.CleanupStack[I].endLifetime();
-        }
-      }
-      Info.CleanupStack.erase(Info.CleanupStack.begin() + NewEnd,
-                              Info.CleanupStack.end());
-    }
-  };
-  typedef ScopeRAII<false> BlockScopeRAII;
-  typedef ScopeRAII<true> FullExpressionRAII;
-}
-
-bool SubobjectDesignator::checkSubobject(EvalInfo &Info, const Expr *E,
-                                         CheckSubobjectKind CSK) {
-  if (Invalid)
-    return false;
-  if (isOnePastTheEnd()) {
-    Info.CCEDiag(E, diag::note_constexpr_past_end_subobject)
-      << CSK;
-    setInvalid();
-    return false;
-  }
-  // Note, we do not diagnose if isMostDerivedAnUnsizedArray(), because there
-  // must actually be at least one array element; even a VLA cannot have a
-  // bound of zero. And if our index is nonzero, we already had a CCEDiag.
-  return true;
-}
-
-void SubobjectDesignator::diagnoseUnsizedArrayPointerArithmetic(EvalInfo &Info,
-                                                                const Expr *E) {
-  Info.CCEDiag(E, diag::note_constexpr_unsized_array_indexed);
-  // Do not set the designator as invalid: we can represent this situation,
-  // and correct handling of __builtin_object_size requires us to do so.
-}
-
-void SubobjectDesignator::diagnosePointerArithmetic(EvalInfo &Info,
-                                                    const Expr *E,
-                                                    const APSInt &N) {
-  // If we're complaining, we must be able to statically determine the size of
-  // the most derived array.
-  if (MostDerivedPathLength == Entries.size() && MostDerivedIsArrayElement)
-    Info.CCEDiag(E, diag::note_constexpr_array_index)
-      << N << /*array*/ 0
-      << static_cast<unsigned>(getMostDerivedArraySize());
-  else
-    Info.CCEDiag(E, diag::note_constexpr_array_index)
-      << N << /*non-array*/ 1;
-  setInvalid();
-}
-
-CallStackFrame::CallStackFrame(EvalInfo &Info, SourceLocation CallLoc,
-                               const FunctionDecl *Callee, const LValue *This,
-                               APValue *Arguments)
-    : Info(Info), Caller(Info.CurrentCall), Callee(Callee), This(This),
-      Arguments(Arguments), CallLoc(CallLoc), Index(Info.NextCallIndex++) {
-  Info.CurrentCall = this;
-  ++Info.CallStackDepth;
-}
-
-CallStackFrame::~CallStackFrame() {
-  assert(Info.CurrentCall == this && "calls retired out of order");
-  --Info.CallStackDepth;
-  Info.CurrentCall = Caller;
-}
-
-APValue &CallStackFrame::createTemporary(const void *Key,
-                                         bool IsLifetimeExtended) {
-  unsigned Version = Info.CurrentCall->getTempVersion();
-  APValue &Result = Temporaries[MapKeyTy(Key, Version)];
-  assert(Result.isUninit() && "temporary created multiple times");
-  Info.CleanupStack.push_back(Cleanup(&Result, IsLifetimeExtended));
-  return Result;
-}
-
-static void describeCall(CallStackFrame *Frame, raw_ostream &Out);
-
-void EvalInfo::addCallStack(unsigned Limit) {
-  // Determine which calls to skip, if any.
-  unsigned ActiveCalls = CallStackDepth - 1;
-  unsigned SkipStart = ActiveCalls, SkipEnd = SkipStart;
-  if (Limit && Limit < ActiveCalls) {
-    SkipStart = Limit / 2 + Limit % 2;
-    SkipEnd = ActiveCalls - Limit / 2;
-  }
-
-  // Walk the call stack and add the diagnostics.
-  unsigned CallIdx = 0;
-  for (CallStackFrame *Frame = CurrentCall; Frame != &BottomFrame;
-       Frame = Frame->Caller, ++CallIdx) {
-    // Skip this call?
-    if (CallIdx >= SkipStart && CallIdx < SkipEnd) {
-      if (CallIdx == SkipStart) {
-        // Note that we're skipping calls.
-        addDiag(Frame->CallLoc, diag::note_constexpr_calls_suppressed)
-          << unsigned(ActiveCalls - Limit);
-      }
-      continue;
-    }
-
-    // Use a different note for an inheriting constructor, because from the
-    // user's perspective it's not really a function at all.
-    if (auto *CD = dyn_cast_or_null<CXXConstructorDecl>(Frame->Callee)) {
-      if (CD->isInheritingConstructor()) {
-        addDiag(Frame->CallLoc, diag::note_constexpr_inherited_ctor_call_here)
-          << CD->getParent();
-        continue;
-      }
-    }
-
-    SmallVector<char, 128> Buffer;
-    llvm::raw_svector_ostream Out(Buffer);
-    describeCall(Frame, Out);
-    addDiag(Frame->CallLoc, diag::note_constexpr_call_here) << Out.str();
-  }
-}
-
-/// Kinds of access we can perform on an object, for diagnostics.
-enum AccessKinds {
-  AK_Read,
-  AK_Assign,
-  AK_Increment,
-  AK_Decrement
-};
-
-namespace {
-  struct ComplexValue {
-  private:
-    bool IsInt;
-
-  public:
-    APSInt IntReal, IntImag;
-    APFloat FloatReal, FloatImag;
-
-    ComplexValue() : FloatReal(APFloat::Bogus()), FloatImag(APFloat::Bogus()) {}
-
-    void makeComplexFloat() { IsInt = false; }
-    bool isComplexFloat() const { return !IsInt; }
-    APFloat &getComplexFloatReal() { return FloatReal; }
-    APFloat &getComplexFloatImag() { return FloatImag; }
-
-    void makeComplexInt() { IsInt = true; }
-    bool isComplexInt() const { return IsInt; }
-    APSInt &getComplexIntReal() { return IntReal; }
-    APSInt &getComplexIntImag() { return IntImag; }
-
-    void moveInto(APValue &v) const {
-      if (isComplexFloat())
-        v = APValue(FloatReal, FloatImag);
-      else
-        v = APValue(IntReal, IntImag);
-    }
-    void setFrom(const APValue &v) {
-      assert(v.isComplexFloat() || v.isComplexInt());
-      if (v.isComplexFloat()) {
-        makeComplexFloat();
-        FloatReal = v.getComplexFloatReal();
-        FloatImag = v.getComplexFloatImag();
-      } else {
-        makeComplexInt();
-        IntReal = v.getComplexIntReal();
-        IntImag = v.getComplexIntImag();
-      }
-    }
-  };
-
-  struct LValue {
-    APValue::LValueBase Base;
-    CharUnits Offset;
-    SubobjectDesignator Designator;
-    bool IsNullPtr : 1;
-    bool InvalidBase : 1;
-
-    const APValue::LValueBase getLValueBase() const { return Base; }
-    CharUnits &getLValueOffset() { return Offset; }
-    const CharUnits &getLValueOffset() const { return Offset; }
-    SubobjectDesignator &getLValueDesignator() { return Designator; }
-    const SubobjectDesignator &getLValueDesignator() const { return Designator;}
-    bool isNullPointer() const { return IsNullPtr;}
-
-    unsigned getLValueCallIndex() const { return Base.getCallIndex(); }
-    unsigned getLValueVersion() const { return Base.getVersion(); }
-
-    void moveInto(APValue &V) const {
-      if (Designator.Invalid)
-        V = APValue(Base, Offset, APValue::NoLValuePath(), IsNullPtr);
-      else {
-        assert(!InvalidBase && "APValues can't handle invalid LValue bases");
-        V = APValue(Base, Offset, Designator.Entries,
-                    Designator.IsOnePastTheEnd, IsNullPtr);
-      }
-    }
-    void setFrom(ASTContext &Ctx, const APValue &V) {
-      assert(V.isLValue() && "Setting LValue from a non-LValue?");
-      Base = V.getLValueBase();
-      Offset = V.getLValueOffset();
-      InvalidBase = false;
-      Designator = SubobjectDesignator(Ctx, V);
-      IsNullPtr = V.isNullPointer();
-    }
-
-    void set(APValue::LValueBase B, bool BInvalid = false) {
-#ifndef NDEBUG
-      // We only allow a few types of invalid bases. Enforce that here.
-      if (BInvalid) {
-        const auto *E = B.get<const Expr *>();
-        assert((isa<MemberExpr>(E) || tryUnwrapAllocSizeCall(E)) &&
-               "Unexpected type of invalid base");
-      }
-#endif
-
-      Base = B;
-      Offset = CharUnits::fromQuantity(0);
-      InvalidBase = BInvalid;
-      Designator = SubobjectDesignator(getType(B));
-      IsNullPtr = false;
-    }
-
-    void setNull(QualType PointerTy, uint64_t TargetVal) {
-      Base = (Expr *)nullptr;
-      Offset = CharUnits::fromQuantity(TargetVal);
-      InvalidBase = false;
-      Designator = SubobjectDesignator(PointerTy->getPointeeType());
-      IsNullPtr = true;
-    }
-
-    void setInvalid(APValue::LValueBase B, unsigned I = 0) {
-      set(B, true);
-    }
-
-  private:
-    // Check that this LValue is not based on a null pointer. If it is, produce
-    // a diagnostic and mark the designator as invalid.
-    template <typename GenDiagType>
-    bool checkNullPointerDiagnosingWith(const GenDiagType &GenDiag) {
-      if (Designator.Invalid)
-        return false;
-      if (IsNullPtr) {
-        GenDiag();
-        Designator.setInvalid();
-        return false;
-      }
-      return true;
-    }
-
-  public:
-    bool checkNullPointer(EvalInfo &Info, const Expr *E,
-                          CheckSubobjectKind CSK) {
-      return checkNullPointerDiagnosingWith([&Info, E, CSK] {
-        Info.CCEDiag(E, diag::note_constexpr_null_subobject) << CSK;
-      });
-    }
-
-    bool checkNullPointerForFoldAccess(EvalInfo &Info, const Expr *E,
-                                       AccessKinds AK) {
-      return checkNullPointerDiagnosingWith([&Info, E, AK] {
-        Info.FFDiag(E, diag::note_constexpr_access_null) << AK;
-      });
-    }
-
-    // Check this LValue refers to an object. If not, set the designator to be
-    // invalid and emit a diagnostic.
-    bool checkSubobject(EvalInfo &Info, const Expr *E, CheckSubobjectKind CSK) {
-      return (CSK == CSK_ArrayToPointer || checkNullPointer(Info, E, CSK)) &&
-             Designator.checkSubobject(Info, E, CSK);
-    }
-
-    void addDecl(EvalInfo &Info, const Expr *E,
-                 const Decl *D, bool Virtual = false) {
-      if (checkSubobject(Info, E, isa<FieldDecl>(D) ? CSK_Field : CSK_Base))
-        Designator.addDeclUnchecked(D, Virtual);
-    }
-    void addUnsizedArray(EvalInfo &Info, const Expr *E, QualType ElemTy) {
-      if (!Designator.Entries.empty()) {
-        Info.CCEDiag(E, diag::note_constexpr_unsupported_unsized_array);
-        Designator.setInvalid();
-        return;
-      }
-      if (checkSubobject(Info, E, CSK_ArrayToPointer)) {
-        assert(getType(Base)->isPointerType() || getType(Base)->isArrayType());
-        Designator.FirstEntryIsAnUnsizedArray = true;
-        Designator.addUnsizedArrayUnchecked(ElemTy);
-      }
-    }
-    void addArray(EvalInfo &Info, const Expr *E, const ConstantArrayType *CAT) {
-      if (checkSubobject(Info, E, CSK_ArrayToPointer))
-        Designator.addArrayUnchecked(CAT);
-    }
-    void addComplex(EvalInfo &Info, const Expr *E, QualType EltTy, bool Imag) {
-      if (checkSubobject(Info, E, Imag ? CSK_Imag : CSK_Real))
-        Designator.addComplexUnchecked(EltTy, Imag);
-    }
-    void clearIsNullPointer() {
-      IsNullPtr = false;
-    }
-    void adjustOffsetAndIndex(EvalInfo &Info, const Expr *E,
-                              const APSInt &Index, CharUnits ElementSize) {
-      // An index of 0 has no effect. (In C, adding 0 to a null pointer is UB,
-      // but we're not required to diagnose it and it's valid in C++.)
-      if (!Index)
-        return;
-
-      // Compute the new offset in the appropriate width, wrapping at 64 bits.
-      // FIXME: When compiling for a 32-bit target, we should use 32-bit
-      // offsets.
-      uint64_t Offset64 = Offset.getQuantity();
-      uint64_t ElemSize64 = ElementSize.getQuantity();
-      uint64_t Index64 = Index.extOrTrunc(64).getZExtValue();
-      Offset = CharUnits::fromQuantity(Offset64 + ElemSize64 * Index64);
-
-      if (checkNullPointer(Info, E, CSK_ArrayIndex))
-        Designator.adjustIndex(Info, E, Index);
-      clearIsNullPointer();
-    }
-    void adjustOffset(CharUnits N) {
-      Offset += N;
-      if (N.getQuantity())
-        clearIsNullPointer();
-    }
-  };
-
-  struct MemberPtr {
-    MemberPtr() {}
-    explicit MemberPtr(const ValueDecl *Decl) :
-      DeclAndIsDerivedMember(Decl, false), Path() {}
-
-    /// The member or (direct or indirect) field referred to by this member
-    /// pointer, or 0 if this is a null member pointer.
-    const ValueDecl *getDecl() const {
-      return DeclAndIsDerivedMember.getPointer();
-    }
-    /// Is this actually a member of some type derived from the relevant class?
-    bool isDerivedMember() const {
-      return DeclAndIsDerivedMember.getInt();
-    }
-    /// Get the class which the declaration actually lives in.
-    const CXXRecordDecl *getContainingRecord() const {
-      return cast<CXXRecordDecl>(
-          DeclAndIsDerivedMember.getPointer()->getDeclContext());
-    }
-
-    void moveInto(APValue &V) const {
-      V = APValue(getDecl(), isDerivedMember(), Path);
-    }
-    void setFrom(const APValue &V) {
-      assert(V.isMemberPointer());
-      DeclAndIsDerivedMember.setPointer(V.getMemberPointerDecl());
-      DeclAndIsDerivedMember.setInt(V.isMemberPointerToDerivedMember());
-      Path.clear();
-      ArrayRef<const CXXRecordDecl*> P = V.getMemberPointerPath();
-      Path.insert(Path.end(), P.begin(), P.end());
-    }
-
-    /// DeclAndIsDerivedMember - The member declaration, and a flag indicating
-    /// whether the member is a member of some class derived from the class type
-    /// of the member pointer.
-    llvm::PointerIntPair<const ValueDecl*, 1, bool> DeclAndIsDerivedMember;
-    /// Path - The path of base/derived classes from the member declaration's
-    /// class (exclusive) to the class type of the member pointer (inclusive).
-    SmallVector<const CXXRecordDecl*, 4> Path;
-
-    /// Perform a cast towards the class of the Decl (either up or down the
-    /// hierarchy).
-    bool castBack(const CXXRecordDecl *Class) {
-      assert(!Path.empty());
-      const CXXRecordDecl *Expected;
-      if (Path.size() >= 2)
-        Expected = Path[Path.size() - 2];
-      else
-        Expected = getContainingRecord();
-      if (Expected->getCanonicalDecl() != Class->getCanonicalDecl()) {
-        // C++11 [expr.static.cast]p12: In a conversion from (D::*) to (B::*),
-        // if B does not contain the original member and is not a base or
-        // derived class of the class containing the original member, the result
-        // of the cast is undefined.
-        // C++11 [conv.mem]p2 does not cover this case for a cast from (B::*) to
-        // (D::*). We consider that to be a language defect.
-        return false;
-      }
-      Path.pop_back();
-      return true;
-    }
-    /// Perform a base-to-derived member pointer cast.
-    bool castToDerived(const CXXRecordDecl *Derived) {
-      if (!getDecl())
-        return true;
-      if (!isDerivedMember()) {
-        Path.push_back(Derived);
-        return true;
-      }
-      if (!castBack(Derived))
-        return false;
-      if (Path.empty())
-        DeclAndIsDerivedMember.setInt(false);
-      return true;
-    }
-    /// Perform a derived-to-base member pointer cast.
-    bool castToBase(const CXXRecordDecl *Base) {
-      if (!getDecl())
-        return true;
-      if (Path.empty())
-        DeclAndIsDerivedMember.setInt(true);
-      if (isDerivedMember()) {
-        Path.push_back(Base);
-        return true;
-      }
-      return castBack(Base);
-    }
-  };
-
-  /// Compare two member pointers, which are assumed to be of the same type.
-  static bool operator==(const MemberPtr &LHS, const MemberPtr &RHS) {
-    if (!LHS.getDecl() || !RHS.getDecl())
-      return !LHS.getDecl() && !RHS.getDecl();
-    if (LHS.getDecl()->getCanonicalDecl() != RHS.getDecl()->getCanonicalDecl())
-      return false;
-    return LHS.Path == RHS.Path;
-  }
-}
-
-static bool Evaluate(APValue &Result, EvalInfo &Info, const Expr *E);
-static bool EvaluateInPlace(APValue &Result, EvalInfo &Info,
-                            const LValue &This, const Expr *E,
-                            bool AllowNonLiteralTypes = false);
-static bool EvaluateLValue(const Expr *E, LValue &Result, EvalInfo &Info,
-                           bool InvalidBaseOK = false);
-static bool EvaluatePointer(const Expr *E, LValue &Result, EvalInfo &Info,
-                            bool InvalidBaseOK = false);
-static bool EvaluateMemberPointer(const Expr *E, MemberPtr &Result,
-                                  EvalInfo &Info);
-static bool EvaluateTemporary(const Expr *E, LValue &Result, EvalInfo &Info);
-static bool EvaluateInteger(const Expr *E, APSInt &Result, EvalInfo &Info);
-static bool EvaluateIntegerOrLValue(const Expr *E, APValue &Result,
-                                    EvalInfo &Info);
-static bool EvaluateFloat(const Expr *E, APFloat &Result, EvalInfo &Info);
-static bool EvaluateComplex(const Expr *E, ComplexValue &Res, EvalInfo &Info);
-static bool EvaluateAtomic(const Expr *E, const LValue *This, APValue &Result,
-                           EvalInfo &Info);
-static bool EvaluateAsRValue(EvalInfo &Info, const Expr *E, APValue &Result);
-
-//===----------------------------------------------------------------------===//
-// Misc utilities
-//===----------------------------------------------------------------------===//
-
-/// A helper function to create a temporary and set an LValue.
-template <class KeyTy>
-static APValue &createTemporary(const KeyTy *Key, bool IsLifetimeExtended,
-                                LValue &LV, CallStackFrame &Frame) {
-  LV.set({Key, Frame.Info.CurrentCall->Index,
-          Frame.Info.CurrentCall->getTempVersion()});
-  return Frame.createTemporary(Key, IsLifetimeExtended);
-}
-
-/// Negate an APSInt in place, converting it to a signed form if necessary, and
-/// preserving its value (by extending by up to one bit as needed).
-static void negateAsSigned(APSInt &Int) {
-  if (Int.isUnsigned() || Int.isMinSignedValue()) {
-    Int = Int.extend(Int.getBitWidth() + 1);
-    Int.setIsSigned(true);
-  }
-  Int = -Int;
-}
-
-/// Produce a string describing the given constexpr call.
-static void describeCall(CallStackFrame *Frame, raw_ostream &Out) {
-  unsigned ArgIndex = 0;
-  bool IsMemberCall = isa<CXXMethodDecl>(Frame->Callee) &&
-                      !isa<CXXConstructorDecl>(Frame->Callee) &&
-                      cast<CXXMethodDecl>(Frame->Callee)->isInstance();
-
-  if (!IsMemberCall)
-    Out << *Frame->Callee << '(';
-
-  if (Frame->This && IsMemberCall) {
-    APValue Val;
-    Frame->This->moveInto(Val);
-    Val.printPretty(Out, Frame->Info.Ctx,
-                    Frame->This->Designator.MostDerivedType);
-    // FIXME: Add parens around Val if needed.
-    Out << "->" << *Frame->Callee << '(';
-    IsMemberCall = false;
-  }
-
-  for (FunctionDecl::param_const_iterator I = Frame->Callee->param_begin(),
-       E = Frame->Callee->param_end(); I != E; ++I, ++ArgIndex) {
-    if (ArgIndex > (unsigned)IsMemberCall)
-      Out << ", ";
-
-    const ParmVarDecl *Param = *I;
-    const APValue &Arg = Frame->Arguments[ArgIndex];
-    Arg.printPretty(Out, Frame->Info.Ctx, Param->getType());
-
-    if (ArgIndex == 0 && IsMemberCall)
-      Out << "->" << *Frame->Callee << '(';
-  }
-
-  Out << ')';
-}
-
-/// Evaluate an expression to see if it had side-effects, and discard its
-/// result.
-/// \return \c true if the caller should keep evaluating.
-static bool EvaluateIgnoredValue(EvalInfo &Info, const Expr *E) {
-  APValue Scratch;
-  if (!Evaluate(Scratch, Info, E))
-    // We don't need the value, but we might have skipped a side effect here.
-    return Info.noteSideEffect();
-  return true;
-}
-
-/// Should this call expression be treated as a string literal?
-static bool IsStringLiteralCall(const CallExpr *E) {
-  unsigned Builtin = E->getBuiltinCallee();
-  return (Builtin == Builtin::BI__builtin___CFStringMakeConstantString ||
-          Builtin == Builtin::BI__builtin___NSStringMakeConstantString);
-}
-
-static bool IsGlobalLValue(APValue::LValueBase B) {
-  // C++11 [expr.const]p3 An address constant expression is a prvalue core
-  // constant expression of pointer type that evaluates to...
-
-  // ... a null pointer value, or a prvalue core constant expression of type
-  // std::nullptr_t.
-  if (!B) return true;
-
-  if (const ValueDecl *D = B.dyn_cast<const ValueDecl*>()) {
-    // ... the address of an object with static storage duration,
-    if (const VarDecl *VD = dyn_cast<VarDecl>(D))
-      return VD->hasGlobalStorage();
-    // ... the address of a function,
-    return isa<FunctionDecl>(D);
-  }
-
-  const Expr *E = B.get<const Expr*>();
-  switch (E->getStmtClass()) {
-  default:
-    return false;
-  case Expr::CompoundLiteralExprClass: {
-    const CompoundLiteralExpr *CLE = cast<CompoundLiteralExpr>(E);
-    return CLE->isFileScope() && CLE->isLValue();
-  }
-  case Expr::MaterializeTemporaryExprClass:
-    // A materialized temporary might have been lifetime-extended to static
-    // storage duration.
-    return cast<MaterializeTemporaryExpr>(E)->getStorageDuration() == SD_Static;
-  // A string literal has static storage duration.
-  case Expr::StringLiteralClass:
-  case Expr::PredefinedExprClass:
-  case Expr::ObjCStringLiteralClass:
-  case Expr::ObjCEncodeExprClass:
-  case Expr::CXXTypeidExprClass:
-  case Expr::CXXUuidofExprClass:
-    return true;
-  case Expr::CallExprClass:
-    return IsStringLiteralCall(cast<CallExpr>(E));
-  // For GCC compatibility, &&label has static storage duration.
-  case Expr::AddrLabelExprClass:
-    return true;
-  // A Block literal expression may be used as the initialization value for
-  // Block variables at global or local static scope.
-  case Expr::BlockExprClass:
-    return !cast<BlockExpr>(E)->getBlockDecl()->hasCaptures();
-  case Expr::ImplicitValueInitExprClass:
-    // FIXME:
-    // We can never form an lvalue with an implicit value initialization as its
-    // base through expression evaluation, so these only appear in one case: the
-    // implicit variable declaration we invent when checking whether a constexpr
-    // constructor can produce a constant expression. We must assume that such
-    // an expression might be a global lvalue.
-    return true;
-  }
-}
-
-static const ValueDecl *GetLValueBaseDecl(const LValue &LVal) {
-  return LVal.Base.dyn_cast<const ValueDecl*>();
-}
-
-static bool IsLiteralLValue(const LValue &Value) {
-  if (Value.getLValueCallIndex())
-    return false;
-  const Expr *E = Value.Base.dyn_cast<const Expr*>();
-  return E && !isa<MaterializeTemporaryExpr>(E);
-}
-
-static bool IsWeakLValue(const LValue &Value) {
-  const ValueDecl *Decl = GetLValueBaseDecl(Value);
-  return Decl && Decl->isWeak();
-}
-
-static bool isZeroSized(const LValue &Value) {
-  const ValueDecl *Decl = GetLValueBaseDecl(Value);
-  if (Decl && isa<VarDecl>(Decl)) {
-    QualType Ty = Decl->getType();
-    if (Ty->isArrayType())
-      return Ty->isIncompleteType() ||
-             Decl->getASTContext().getTypeSize(Ty) == 0;
-  }
-  return false;
-}
-
-static bool HasSameBase(const LValue &A, const LValue &B) {
-  if (!A.getLValueBase())
-    return !B.getLValueBase();
-  if (!B.getLValueBase())
-    return false;
-
-  if (A.getLValueBase().getOpaqueValue() !=
-      B.getLValueBase().getOpaqueValue()) {
-    const Decl *ADecl = GetLValueBaseDecl(A);
-    if (!ADecl)
-      return false;
-    const Decl *BDecl = GetLValueBaseDecl(B);
-    if (!BDecl || ADecl->getCanonicalDecl() != BDecl->getCanonicalDecl())
-      return false;
-  }
-
-  return IsGlobalLValue(A.getLValueBase()) ||
-         (A.getLValueCallIndex() == B.getLValueCallIndex() &&
-          A.getLValueVersion() == B.getLValueVersion());
-}
-
-static void NoteLValueLocation(EvalInfo &Info, APValue::LValueBase Base) {
-  assert(Base && "no location for a null lvalue");
-  const ValueDecl *VD = Base.dyn_cast<const ValueDecl*>();
-  if (VD)
-    Info.Note(VD->getLocation(), diag::note_declared_at);
-  else
-    Info.Note(Base.get<const Expr*>()->getExprLoc(),
-              diag::note_constexpr_temporary_here);
-}
-
-/// Check that this reference or pointer core constant expression is a valid
-/// value for an address or reference constant expression. Return true if we
-/// can fold this expression, whether or not it's a constant expression.
-static bool CheckLValueConstantExpression(EvalInfo &Info, SourceLocation Loc,
-                                          QualType Type, const LValue &LVal,
-                                          Expr::ConstExprUsage Usage) {
-  bool IsReferenceType = Type->isReferenceType();
-
-  APValue::LValueBase Base = LVal.getLValueBase();
-  const SubobjectDesignator &Designator = LVal.getLValueDesignator();
-
-  // Check that the object is a global. Note that the fake 'this' object we
-  // manufacture when checking potential constant expressions is conservatively
-  // assumed to be global here.
-  if (!IsGlobalLValue(Base)) {
-    if (Info.getLangOpts().CPlusPlus11) {
-      const ValueDecl *VD = Base.dyn_cast<const ValueDecl*>();
-      Info.FFDiag(Loc, diag::note_constexpr_non_global, 1)
-        << IsReferenceType << !Designator.Entries.empty()
-        << !!VD << VD;
-      NoteLValueLocation(Info, Base);
-    } else {
-      Info.FFDiag(Loc);
-    }
-    // Don't allow references to temporaries to escape.
-    return false;
-  }
-  assert((Info.checkingPotentialConstantExpression() ||
-          LVal.getLValueCallIndex() == 0) &&
-         "have call index for global lvalue");
-
-  if (const ValueDecl *VD = Base.dyn_cast<const ValueDecl*>()) {
-    if (const VarDecl *Var = dyn_cast<const VarDecl>(VD)) {
-      // Check if this is a thread-local variable.
-      if (Var->getTLSKind())
-        return false;
-
-      // A dllimport variable never acts like a constant.
-      if (Usage == Expr::EvaluateForCodeGen && Var->hasAttr<DLLImportAttr>())
-        return false;
-    }
-    if (const auto *FD = dyn_cast<const FunctionDecl>(VD)) {
-      // __declspec(dllimport) must be handled very carefully:
-      // We must never initialize an expression with the thunk in C++.
-      // Doing otherwise would allow the same id-expression to yield
-      // different addresses for the same function in different translation
-      // units.  However, this means that we must dynamically initialize the
-      // expression with the contents of the import address table at runtime.
-      //
-      // The C language has no notion of ODR; furthermore, it has no notion of
-      // dynamic initialization.  This means that we are permitted to
-      // perform initialization with the address of the thunk.
-      if (Info.getLangOpts().CPlusPlus && Usage == Expr::EvaluateForCodeGen &&
-          FD->hasAttr<DLLImportAttr>())
-        return false;
-    }
-  }
-
-  // Allow address constant expressions to be past-the-end pointers. This is
-  // an extension: the standard requires them to point to an object.
-  if (!IsReferenceType)
-    return true;
-
-  // A reference constant expression must refer to an object.
-  if (!Base) {
-    // FIXME: diagnostic
-    Info.CCEDiag(Loc);
-    return true;
-  }
-
-  // Does this refer one past the end of some object?
-  if (!Designator.Invalid && Designator.isOnePastTheEnd()) {
-    const ValueDecl *VD = Base.dyn_cast<const ValueDecl*>();
-    Info.FFDiag(Loc, diag::note_constexpr_past_end, 1)
-      << !Designator.Entries.empty() << !!VD << VD;
-    NoteLValueLocation(Info, Base);
-  }
-
-  return true;
-}
-
-/// Member pointers are constant expressions unless they point to a
-/// non-virtual dllimport member function.
-static bool CheckMemberPointerConstantExpression(EvalInfo &Info,
-                                                 SourceLocation Loc,
-                                                 QualType Type,
-                                                 const APValue &Value,
-                                                 Expr::ConstExprUsage Usage) {
-  const ValueDecl *Member = Value.getMemberPointerDecl();
-  const auto *FD = dyn_cast_or_null<CXXMethodDecl>(Member);
-  if (!FD)
-    return true;
-  return Usage == Expr::EvaluateForMangling || FD->isVirtual() ||
-         !FD->hasAttr<DLLImportAttr>();
-}
-
-/// Check that this core constant expression is of literal type, and if not,
-/// produce an appropriate diagnostic.
-static bool CheckLiteralType(EvalInfo &Info, const Expr *E,
-                             const LValue *This = nullptr) {
-  if (!E->isRValue() || E->getType()->isLiteralType(Info.Ctx))
-    return true;
-
-  // C++1y: A constant initializer for an object o [...] may also invoke
-  // constexpr constructors for o and its subobjects even if those objects
-  // are of non-literal class types.
-  //
-  // C++11 missed this detail for aggregates, so classes like this:
-  //   struct foo_t { union { int i; volatile int j; } u; };
-  // are not (obviously) initializable like so:
-  //   __attribute__((__require_constant_initialization__))
-  //   static const foo_t x = {{0}};
-  // because "i" is a subobject with non-literal initialization (due to the
-  // volatile member of the union). See:
-  //   http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#1677
-  // Therefore, we use the C++1y behavior.
-  if (This && Info.EvaluatingDecl == This->getLValueBase())
-    return true;
-
-  // Prvalue constant expressions must be of literal types.
-  if (Info.getLangOpts().CPlusPlus11)
-    Info.FFDiag(E, diag::note_constexpr_nonliteral)
-      << E->getType();
-  else
-    Info.FFDiag(E, diag::note_invalid_subexpr_in_const_expr);
-  return false;
-}
-
-/// Check that this core constant expression value is a valid value for a
-/// constant expression. If not, report an appropriate diagnostic. Does not
-/// check that the expression is of literal type.
-static bool
-CheckConstantExpression(EvalInfo &Info, SourceLocation DiagLoc, QualType Type,
-                        const APValue &Value,
-                        Expr::ConstExprUsage Usage = Expr::EvaluateForCodeGen) {
-  if (Value.isUninit()) {
-    Info.FFDiag(DiagLoc, diag::note_constexpr_uninitialized)
-      << true << Type;
-    return false;
-  }
-
-  // We allow _Atomic(T) to be initialized from anything that T can be
-  // initialized from.
-  if (const AtomicType *AT = Type->getAs<AtomicType>())
-    Type = AT->getValueType();
-
-  // Core issue 1454: For a literal constant expression of array or class type,
-  // each subobject of its value shall have been initialized by a constant
-  // expression.
-  if (Value.isArray()) {
-    QualType EltTy = Type->castAsArrayTypeUnsafe()->getElementType();
-    for (unsigned I = 0, N = Value.getArrayInitializedElts(); I != N; ++I) {
-      if (!CheckConstantExpression(Info, DiagLoc, EltTy,
-                                   Value.getArrayInitializedElt(I), Usage))
-        return false;
-    }
-    if (!Value.hasArrayFiller())
-      return true;
-    return CheckConstantExpression(Info, DiagLoc, EltTy, Value.getArrayFiller(),
-                                   Usage);
-  }
-  if (Value.isUnion() && Value.getUnionField()) {
-    return CheckConstantExpression(Info, DiagLoc,
-                                   Value.getUnionField()->getType(),
-                                   Value.getUnionValue(), Usage);
-  }
-  if (Value.isStruct()) {
-    RecordDecl *RD = Type->castAs<RecordType>()->getDecl();
-    if (const CXXRecordDecl *CD = dyn_cast<CXXRecordDecl>(RD)) {
-      unsigned BaseIndex = 0;
-      for (const CXXBaseSpecifier &BS : CD->bases()) {
-        if (!CheckConstantExpression(Info, DiagLoc, BS.getType(),
-                                     Value.getStructBase(BaseIndex), Usage))
-          return false;
-        ++BaseIndex;
-      }
-    }
-    for (const auto *I : RD->fields()) {
-      if (I->isUnnamedBitfield())
-        continue;
-
-      if (!CheckConstantExpression(Info, DiagLoc, I->getType(),
-                                   Value.getStructField(I->getFieldIndex()),
-                                   Usage))
-        return false;
-    }
-  }
-
-  if (Value.isLValue()) {
-    LValue LVal;
-    LVal.setFrom(Info.Ctx, Value);
-    return CheckLValueConstantExpression(Info, DiagLoc, Type, LVal, Usage);
-  }
-
-  if (Value.isMemberPointer())
-    return CheckMemberPointerConstantExpression(Info, DiagLoc, Type, Value, Usage);
-
-  // Everything else is fine.
-  return true;
-}
-
-static bool EvalPointerValueAsBool(const APValue &Value, bool &Result) {
-  // A null base expression indicates a null pointer.  These are always
-  // evaluatable, and they are false unless the offset is zero.
-  if (!Value.getLValueBase()) {
-    Result = !Value.getLValueOffset().isZero();
-    return true;
-  }
-
-  // We have a non-null base.  These are generally known to be true, but if it's
-  // a weak declaration it can be null at runtime.
-  Result = true;
-  const ValueDecl *Decl = Value.getLValueBase().dyn_cast<const ValueDecl*>();
-  return !Decl || !Decl->isWeak();
-}
-
-static bool HandleConversionToBool(const APValue &Val, bool &Result) {
-  switch (Val.getKind()) {
-  case APValue::Uninitialized:
-    return false;
-  case APValue::Int:
-    Result = Val.getInt().getBoolValue();
-    return true;
-  case APValue::Float:
-    Result = !Val.getFloat().isZero();
-    return true;
-  case APValue::ComplexInt:
-    Result = Val.getComplexIntReal().getBoolValue() ||
-             Val.getComplexIntImag().getBoolValue();
-    return true;
-  case APValue::ComplexFloat:
-    Result = !Val.getComplexFloatReal().isZero() ||
-             !Val.getComplexFloatImag().isZero();
-    return true;
-  case APValue::LValue:
-    return EvalPointerValueAsBool(Val, Result);
-  case APValue::MemberPointer:
-    Result = Val.getMemberPointerDecl();
-    return true;
-  case APValue::Vector:
-  case APValue::Array:
-  case APValue::Struct:
-  case APValue::Union:
-  case APValue::AddrLabelDiff:
-    return false;
-  }
-
-  llvm_unreachable("unknown APValue kind");
-}
-
-static bool EvaluateAsBooleanCondition(const Expr *E, bool &Result,
-                                       EvalInfo &Info) {
-  assert(E->isRValue() && "missing lvalue-to-rvalue conv in bool condition");
-  APValue Val;
-  if (!Evaluate(Val, Info, E))
-    return false;
-  return HandleConversionToBool(Val, Result);
-}
-
-template<typename T>
-static bool HandleOverflow(EvalInfo &Info, const Expr *E,
-                           const T &SrcValue, QualType DestType) {
-  Info.CCEDiag(E, diag::note_constexpr_overflow)
-    << SrcValue << DestType;
-  return Info.noteUndefinedBehavior();
-}
-
-static bool HandleFloatToIntCast(EvalInfo &Info, const Expr *E,
-                                 QualType SrcType, const APFloat &Value,
-                                 QualType DestType, APSInt &Result) {
-  unsigned DestWidth = Info.Ctx.getIntWidth(DestType);
-  // Determine whether we are converting to unsigned or signed.
-  bool DestSigned = DestType->isSignedIntegerOrEnumerationType();
-
-  Result = APSInt(DestWidth, !DestSigned);
-  bool ignored;
-  if (Value.convertToInteger(Result, llvm::APFloat::rmTowardZero, &ignored)
-      & APFloat::opInvalidOp)
-    return HandleOverflow(Info, E, Value, DestType);
-  return true;
-}
-
-static bool HandleFloatToFloatCast(EvalInfo &Info, const Expr *E,
-                                   QualType SrcType, QualType DestType,
-                                   APFloat &Result) {
-  APFloat Value = Result;
-  bool ignored;
-  if (Result.convert(Info.Ctx.getFloatTypeSemantics(DestType),
-                     APFloat::rmNearestTiesToEven, &ignored)
-      & APFloat::opOverflow)
-    return HandleOverflow(Info, E, Value, DestType);
-  return true;
-}
-
-static APSInt HandleIntToIntCast(EvalInfo &Info, const Expr *E,
-                                 QualType DestType, QualType SrcType,
-                                 const APSInt &Value) {
-  unsigned DestWidth = Info.Ctx.getIntWidth(DestType);
-  // Figure out if this is a truncate, extend or noop cast.
-  // If the input is signed, do a sign extend, noop, or truncate.
-  APSInt Result = Value.extOrTrunc(DestWidth);
-  Result.setIsUnsigned(DestType->isUnsignedIntegerOrEnumerationType());
-  if (DestType->isBooleanType())
-    Result = Value.getBoolValue();
-  return Result;
-}
-
-static bool HandleIntToFloatCast(EvalInfo &Info, const Expr *E,
-                                 QualType SrcType, const APSInt &Value,
-                                 QualType DestType, APFloat &Result) {
-  Result = APFloat(Info.Ctx.getFloatTypeSemantics(DestType), 1);
-  if (Result.convertFromAPInt(Value, Value.isSigned(),
-                              APFloat::rmNearestTiesToEven)
-      & APFloat::opOverflow)
-    return HandleOverflow(Info, E, Value, DestType);
-  return true;
-}
-
-static bool truncateBitfieldValue(EvalInfo &Info, const Expr *E,
-                                  APValue &Value, const FieldDecl *FD) {
-  assert(FD->isBitField() && "truncateBitfieldValue on non-bitfield");
-
-  if (!Value.isInt()) {
-    // Trying to store a pointer-cast-to-integer into a bitfield.
-    // FIXME: In this case, we should provide the diagnostic for casting
-    // a pointer to an integer.
-    assert(Value.isLValue() && "integral value neither int nor lvalue?");
-    Info.FFDiag(E);
-    return false;
-  }
-
-  APSInt &Int = Value.getInt();
-  unsigned OldBitWidth = Int.getBitWidth();
-  unsigned NewBitWidth = FD->getBitWidthValue(Info.Ctx);
-  if (NewBitWidth < OldBitWidth)
-    Int = Int.trunc(NewBitWidth).extend(OldBitWidth);
-  return true;
-}
-
-static bool EvalAndBitcastToAPInt(EvalInfo &Info, const Expr *E,
-                                  llvm::APInt &Res) {
-  APValue SVal;
-  if (!Evaluate(SVal, Info, E))
-    return false;
-  if (SVal.isInt()) {
-    Res = SVal.getInt();
-    return true;
-  }
-  if (SVal.isFloat()) {
-    Res = SVal.getFloat().bitcastToAPInt();
-    return true;
-  }
-  if (SVal.isVector()) {
-    QualType VecTy = E->getType();
-    unsigned VecSize = Info.Ctx.getTypeSize(VecTy);
-    QualType EltTy = VecTy->castAs<VectorType>()->getElementType();
-    unsigned EltSize = Info.Ctx.getTypeSize(EltTy);
-    bool BigEndian = Info.Ctx.getTargetInfo().isBigEndian();
-    Res = llvm::APInt::getNullValue(VecSize);
-    for (unsigned i = 0; i < SVal.getVectorLength(); i++) {
-      APValue &Elt = SVal.getVectorElt(i);
-      llvm::APInt EltAsInt;
-      if (Elt.isInt()) {
-        EltAsInt = Elt.getInt();
-      } else if (Elt.isFloat()) {
-        EltAsInt = Elt.getFloat().bitcastToAPInt();
-      } else {
-        // Don't try to handle vectors of anything other than int or float
-        // (not sure if it's possible to hit this case).
-        Info.FFDiag(E, diag::note_invalid_subexpr_in_const_expr);
-        return false;
-      }
-      unsigned BaseEltSize = EltAsInt.getBitWidth();
-      if (BigEndian)
-        Res |= EltAsInt.zextOrTrunc(VecSize).rotr(i*EltSize+BaseEltSize);
-      else
-        Res |= EltAsInt.zextOrTrunc(VecSize).rotl(i*EltSize);
-    }
-    return true;
-  }
-  // Give up if the input isn't an int, float, or vector.  For example, we
-  // reject "(v4i16)(intptr_t)&a".
-  Info.FFDiag(E, diag::note_invalid_subexpr_in_const_expr);
-  return false;
-}
-
-/// Perform the given integer operation, which is known to need at most BitWidth
-/// bits, and check for overflow in the original type (if that type was not an
-/// unsigned type).
-template<typename Operation>
-static bool CheckedIntArithmetic(EvalInfo &Info, const Expr *E,
-                                 const APSInt &LHS, const APSInt &RHS,
-                                 unsigned BitWidth, Operation Op,
-                                 APSInt &Result) {
-  if (LHS.isUnsigned()) {
-    Result = Op(LHS, RHS);
-    return true;
-  }
-
-  APSInt Value(Op(LHS.extend(BitWidth), RHS.extend(BitWidth)), false);
-  Result = Value.trunc(LHS.getBitWidth());
-  if (Result.extend(BitWidth) != Value) {
-    if (Info.checkingForOverflow())
-      Info.Ctx.getDiagnostics().Report(E->getExprLoc(),
-                                       diag::warn_integer_constant_overflow)
-          << Result.toString(10) << E->getType();
-    else
-      return HandleOverflow(Info, E, Value, E->getType());
-  }
-  return true;
-}
-
-/// Perform the given binary integer operation.
-static bool handleIntIntBinOp(EvalInfo &Info, const Expr *E, const APSInt &LHS,
-                              BinaryOperatorKind Opcode, APSInt RHS,
-                              APSInt &Result) {
-  switch (Opcode) {
-  default:
-    Info.FFDiag(E);
-    return false;
-  case BO_Mul:
-    return CheckedIntArithmetic(Info, E, LHS, RHS, LHS.getBitWidth() * 2,
-                                std::multiplies<APSInt>(), Result);
-  case BO_Add:
-    return CheckedIntArithmetic(Info, E, LHS, RHS, LHS.getBitWidth() + 1,
-                                std::plus<APSInt>(), Result);
-  case BO_Sub:
-    return CheckedIntArithmetic(Info, E, LHS, RHS, LHS.getBitWidth() + 1,
-                                std::minus<APSInt>(), Result);
-  case BO_And: Result = LHS & RHS; return true;
-  case BO_Xor: Result = LHS ^ RHS; return true;
-  case BO_Or:  Result = LHS | RHS; return true;
-  case BO_Div:
-  case BO_Rem:
-    if (RHS == 0) {
-      Info.FFDiag(E, diag::note_expr_divide_by_zero);
-      return false;
-    }
-    Result = (Opcode == BO_Rem ? LHS % RHS : LHS / RHS);
-    // Check for overflow case: INT_MIN / -1 or INT_MIN % -1. APSInt supports
-    // this operation and gives the two's complement result.
-    if (RHS.isNegative() && RHS.isAllOnesValue() &&
-        LHS.isSigned() && LHS.isMinSignedValue())
-      return HandleOverflow(Info, E, -LHS.extend(LHS.getBitWidth() + 1),
-                            E->getType());
-    return true;
-  case BO_Shl: {
-    if (Info.getLangOpts().OpenCL)
-      // OpenCL 6.3j: shift values are effectively % word size of LHS.
-      RHS &= APSInt(llvm::APInt(RHS.getBitWidth(),
-                    static_cast<uint64_t>(LHS.getBitWidth() - 1)),
-                    RHS.isUnsigned());
-    else if (RHS.isSigned() && RHS.isNegative()) {
-      // During constant-folding, a negative shift is an opposite shift. Such
-      // a shift is not a constant expression.
-      Info.CCEDiag(E, diag::note_constexpr_negative_shift) << RHS;
-      RHS = -RHS;
-      goto shift_right;
-    }
-  shift_left:
-    // C++11 [expr.shift]p1: Shift width must be less than the bit width of
-    // the shifted type.
-    unsigned SA = (unsigned) RHS.getLimitedValue(LHS.getBitWidth()-1);
-    if (SA != RHS) {
-      Info.CCEDiag(E, diag::note_constexpr_large_shift)
-        << RHS << E->getType() << LHS.getBitWidth();
-    } else if (LHS.isSigned()) {
-      // C++11 [expr.shift]p2: A signed left shift must have a non-negative
-      // operand, and must not overflow the corresponding unsigned type.
-      if (LHS.isNegative())
-        Info.CCEDiag(E, diag::note_constexpr_lshift_of_negative) << LHS;
-      else if (LHS.countLeadingZeros() < SA)
-        Info.CCEDiag(E, diag::note_constexpr_lshift_discards);
-    }
-    Result = LHS << SA;
-    return true;
-  }
-  case BO_Shr: {
-    if (Info.getLangOpts().OpenCL)
-      // OpenCL 6.3j: shift values are effectively % word size of LHS.
-      RHS &= APSInt(llvm::APInt(RHS.getBitWidth(),
-                    static_cast<uint64_t>(LHS.getBitWidth() - 1)),
-                    RHS.isUnsigned());
-    else if (RHS.isSigned() && RHS.isNegative()) {
-      // During constant-folding, a negative shift is an opposite shift. Such a
-      // shift is not a constant expression.
-      Info.CCEDiag(E, diag::note_constexpr_negative_shift) << RHS;
-      RHS = -RHS;
-      goto shift_left;
-    }
-  shift_right:
-    // C++11 [expr.shift]p1: Shift width must be less than the bit width of the
-    // shifted type.
-    unsigned SA = (unsigned) RHS.getLimitedValue(LHS.getBitWidth()-1);
-    if (SA != RHS)
-      Info.CCEDiag(E, diag::note_constexpr_large_shift)
-        << RHS << E->getType() << LHS.getBitWidth();
-    Result = LHS >> SA;
-    return true;
-  }
-
-  case BO_LT: Result = LHS < RHS; return true;
-  case BO_GT: Result = LHS > RHS; return true;
-  case BO_LE: Result = LHS <= RHS; return true;
-  case BO_GE: Result = LHS >= RHS; return true;
-  case BO_EQ: Result = LHS == RHS; return true;
-  case BO_NE: Result = LHS != RHS; return true;
-  case BO_Cmp:
-    llvm_unreachable("BO_Cmp should be handled elsewhere");
-  }
-}
-
-/// Perform the given binary floating-point operation, in-place, on LHS.
-static bool handleFloatFloatBinOp(EvalInfo &Info, const Expr *E,
-                                  APFloat &LHS, BinaryOperatorKind Opcode,
-                                  const APFloat &RHS) {
-  switch (Opcode) {
-  default:
-    Info.FFDiag(E);
-    return false;
-  case BO_Mul:
-    LHS.multiply(RHS, APFloat::rmNearestTiesToEven);
-    break;
-  case BO_Add:
-    LHS.add(RHS, APFloat::rmNearestTiesToEven);
-    break;
-  case BO_Sub:
-    LHS.subtract(RHS, APFloat::rmNearestTiesToEven);
-    break;
-  case BO_Div:
-    LHS.divide(RHS, APFloat::rmNearestTiesToEven);
-    break;
-  }
-
-  if (LHS.isInfinity() || LHS.isNaN()) {
-    Info.CCEDiag(E, diag::note_constexpr_float_arithmetic) << LHS.isNaN();
-    return Info.noteUndefinedBehavior();
-  }
-  return true;
-}
-
-/// Cast an lvalue referring to a base subobject to a derived class, by
-/// truncating the lvalue's path to the given length.
-static bool CastToDerivedClass(EvalInfo &Info, const Expr *E, LValue &Result,
-                               const RecordDecl *TruncatedType,
-                               unsigned TruncatedElements) {
-  SubobjectDesignator &D = Result.Designator;
-
-  // Check we actually point to a derived class object.
-  if (TruncatedElements == D.Entries.size())
-    return true;
-  assert(TruncatedElements >= D.MostDerivedPathLength &&
-         "not casting to a derived class");
-  if (!Result.checkSubobject(Info, E, CSK_Derived))
-    return false;
-
-  // Truncate the path to the subobject, and remove any derived-to-base offsets.
-  const RecordDecl *RD = TruncatedType;
-  for (unsigned I = TruncatedElements, N = D.Entries.size(); I != N; ++I) {
-    if (RD->isInvalidDecl()) return false;
-    const ASTRecordLayout &Layout = Info.Ctx.getASTRecordLayout(RD);
-    const CXXRecordDecl *Base = getAsBaseClass(D.Entries[I]);
-    if (isVirtualBaseClass(D.Entries[I]))
-      Result.Offset -= Layout.getVBaseClassOffset(Base);
-    else
-      Result.Offset -= Layout.getBaseClassOffset(Base);
-    RD = Base;
-  }
-  D.Entries.resize(TruncatedElements);
-  return true;
-}
-
-static bool HandleLValueDirectBase(EvalInfo &Info, const Expr *E, LValue &Obj,
-                                   const CXXRecordDecl *Derived,
-                                   const CXXRecordDecl *Base,
-                                   const ASTRecordLayout *RL = nullptr) {
-  if (!RL) {
-    if (Derived->isInvalidDecl()) return false;
-    RL = &Info.Ctx.getASTRecordLayout(Derived);
-  }
-
-  Obj.getLValueOffset() += RL->getBaseClassOffset(Base);
-  Obj.addDecl(Info, E, Base, /*Virtual*/ false);
-  return true;
-}
-
-static bool HandleLValueBase(EvalInfo &Info, const Expr *E, LValue &Obj,
-                             const CXXRecordDecl *DerivedDecl,
-                             const CXXBaseSpecifier *Base) {
-  const CXXRecordDecl *BaseDecl = Base->getType()->getAsCXXRecordDecl();
-
-  if (!Base->isVirtual())
-    return HandleLValueDirectBase(Info, E, Obj, DerivedDecl, BaseDecl);
-
-  SubobjectDesignator &D = Obj.Designator;
-  if (D.Invalid)
-    return false;
-
-  // Extract most-derived object and corresponding type.
-  DerivedDecl = D.MostDerivedType->getAsCXXRecordDecl();
-  if (!CastToDerivedClass(Info, E, Obj, DerivedDecl, D.MostDerivedPathLength))
-    return false;
-
-  // Find the virtual base class.
-  if (DerivedDecl->isInvalidDecl()) return false;
-  const ASTRecordLayout &Layout = Info.Ctx.getASTRecordLayout(DerivedDecl);
-  Obj.getLValueOffset() += Layout.getVBaseClassOffset(BaseDecl);
-  Obj.addDecl(Info, E, BaseDecl, /*Virtual*/ true);
-  return true;
-}
-
-static bool HandleLValueBasePath(EvalInfo &Info, const CastExpr *E,
-                                 QualType Type, LValue &Result) {
-  for (CastExpr::path_const_iterator PathI = E->path_begin(),
-                                     PathE = E->path_end();
-       PathI != PathE; ++PathI) {
-    if (!HandleLValueBase(Info, E, Result, Type->getAsCXXRecordDecl(),
-                          *PathI))
-      return false;
-    Type = (*PathI)->getType();
-  }
-  return true;
-}
-
-/// Update LVal to refer to the given field, which must be a member of the type
-/// currently described by LVal.
-static bool HandleLValueMember(EvalInfo &Info, const Expr *E, LValue &LVal,
-                               const FieldDecl *FD,
-                               const ASTRecordLayout *RL = nullptr) {
-  if (!RL) {
-    if (FD->getParent()->isInvalidDecl()) return false;
-    RL = &Info.Ctx.getASTRecordLayout(FD->getParent());
-  }
-
-  unsigned I = FD->getFieldIndex();
-  LVal.adjustOffset(Info.Ctx.toCharUnitsFromBits(RL->getFieldOffset(I)));
-  LVal.addDecl(Info, E, FD);
-  return true;
-}
-
-/// Update LVal to refer to the given indirect field.
-static bool HandleLValueIndirectMember(EvalInfo &Info, const Expr *E,
-                                       LValue &LVal,
-                                       const IndirectFieldDecl *IFD) {
-  for (const auto *C : IFD->chain())
-    if (!HandleLValueMember(Info, E, LVal, cast<FieldDecl>(C)))
-      return false;
-  return true;
-}
-
-/// Get the size of the given type in char units.
-static bool HandleSizeof(EvalInfo &Info, SourceLocation Loc,
-                         QualType Type, CharUnits &Size) {
-  // sizeof(void), __alignof__(void), sizeof(function) = 1 as a gcc
-  // extension.
-  if (Type->isVoidType() || Type->isFunctionType()) {
-    Size = CharUnits::One();
-    return true;
-  }
-
-  if (Type->isDependentType()) {
-    Info.FFDiag(Loc);
-    return false;
-  }
-
-  if (!Type->isConstantSizeType()) {
-    // sizeof(vla) is not a constantexpr: C99 6.5.3.4p2.
-    // FIXME: Better diagnostic.
-    Info.FFDiag(Loc);
-    return false;
-  }
-
-  Size = Info.Ctx.getTypeSizeInChars(Type);
-  return true;
-}
-
-/// Update a pointer value to model pointer arithmetic.
-/// \param Info - Information about the ongoing evaluation.
-/// \param E - The expression being evaluated, for diagnostic purposes.
-/// \param LVal - The pointer value to be updated.
-/// \param EltTy - The pointee type represented by LVal.
-/// \param Adjustment - The adjustment, in objects of type EltTy, to add.
-static bool HandleLValueArrayAdjustment(EvalInfo &Info, const Expr *E,
-                                        LValue &LVal, QualType EltTy,
-                                        APSInt Adjustment) {
-  CharUnits SizeOfPointee;
-  if (!HandleSizeof(Info, E->getExprLoc(), EltTy, SizeOfPointee))
-    return false;
-
-  LVal.adjustOffsetAndIndex(Info, E, Adjustment, SizeOfPointee);
-  return true;
-}
-
-static bool HandleLValueArrayAdjustment(EvalInfo &Info, const Expr *E,
-                                        LValue &LVal, QualType EltTy,
-                                        int64_t Adjustment) {
-  return HandleLValueArrayAdjustment(Info, E, LVal, EltTy,
-                                     APSInt::get(Adjustment));
-}
-
-/// Update an lvalue to refer to a component of a complex number.
-/// \param Info - Information about the ongoing evaluation.
-/// \param LVal - The lvalue to be updated.
-/// \param EltTy - The complex number's component type.
-/// \param Imag - False for the real component, true for the imaginary.
-static bool HandleLValueComplexElement(EvalInfo &Info, const Expr *E,
-                                       LValue &LVal, QualType EltTy,
-                                       bool Imag) {
-  if (Imag) {
-    CharUnits SizeOfComponent;
-    if (!HandleSizeof(Info, E->getExprLoc(), EltTy, SizeOfComponent))
-      return false;
-    LVal.Offset += SizeOfComponent;
-  }
-  LVal.addComplex(Info, E, EltTy, Imag);
-  return true;
-}
-
-static bool handleLValueToRValueConversion(EvalInfo &Info, const Expr *Conv,
-                                           QualType Type, const LValue &LVal,
-                                           APValue &RVal);
-
-/// Try to evaluate the initializer for a variable declaration.
-///
-/// \param Info   Information about the ongoing evaluation.
-/// \param E      An expression to be used when printing diagnostics.
-/// \param VD     The variable whose initializer should be obtained.
-/// \param Frame  The frame in which the variable was created. Must be null
-///               if this variable is not local to the evaluation.
-/// \param Result Filled in with a pointer to the value of the variable.
-static bool evaluateVarDeclInit(EvalInfo &Info, const Expr *E,
-                                const VarDecl *VD, CallStackFrame *Frame,
-                                APValue *&Result, const LValue *LVal) {
-
-  // If this is a parameter to an active constexpr function call, perform
-  // argument substitution.
-  if (const ParmVarDecl *PVD = dyn_cast<ParmVarDecl>(VD)) {
-    // Assume arguments of a potential constant expression are unknown
-    // constant expressions.
-    if (Info.checkingPotentialConstantExpression())
-      return false;
-    if (!Frame || !Frame->Arguments) {
-      Info.FFDiag(E, diag::note_invalid_subexpr_in_const_expr);
-      return false;
-    }
-    Result = &Frame->Arguments[PVD->getFunctionScopeIndex()];
-    return true;
-  }
-
-  // If this is a local variable, dig out its value.
-  if (Frame) {
-    Result = LVal ? Frame->getTemporary(VD, LVal->getLValueVersion())
-                  : Frame->getCurrentTemporary(VD);
-    if (!Result) {
-      // Assume variables referenced within a lambda's call operator that were
-      // not declared within the call operator are captures and during checking
-      // of a potential constant expression, assume they are unknown constant
-      // expressions.
-      assert(isLambdaCallOperator(Frame->Callee) &&
-             (VD->getDeclContext() != Frame->Callee || VD->isInitCapture()) &&
-             "missing value for local variable");
-      if (Info.checkingPotentialConstantExpression())
-        return false;
-      // FIXME: implement capture evaluation during constant expr evaluation.
-      Info.FFDiag(E->getBeginLoc(),
-                  diag::note_unimplemented_constexpr_lambda_feature_ast)
-          << "captures not currently allowed";
-      return false;
-    }
-    return true;
-  }
-
-  // Dig out the initializer, and use the declaration which it's attached to.
-  const Expr *Init = VD->getAnyInitializer(VD);
-  if (!Init || Init->isValueDependent()) {
-    // If we're checking a potential constant expression, the variable could be
-    // initialized later.
-    if (!Info.checkingPotentialConstantExpression())
-      Info.FFDiag(E, diag::note_invalid_subexpr_in_const_expr);
-    return false;
-  }
-
-  // If we're currently evaluating the initializer of this declaration, use that
-  // in-flight value.
-  if (Info.EvaluatingDecl.dyn_cast<const ValueDecl*>() == VD) {
-    Result = Info.EvaluatingDeclValue;
-    return true;
-  }
-
-  // Never evaluate the initializer of a weak variable. We can't be sure that
-  // this is the definition which will be used.
-  if (VD->isWeak()) {
-    Info.FFDiag(E, diag::note_invalid_subexpr_in_const_expr);
-    return false;
-  }
-
-  // Check that we can fold the initializer. In C++, we will have already done
-  // this in the cases where it matters for conformance.
-  SmallVector<PartialDiagnosticAt, 8> Notes;
-  if (!VD->evaluateValue(Notes)) {
-    Info.FFDiag(E, diag::note_constexpr_var_init_non_constant,
-              Notes.size() + 1) << VD;
-    Info.Note(VD->getLocation(), diag::note_declared_at);
-    Info.addNotes(Notes);
-    return false;
-  } else if (!VD->checkInitIsICE()) {
-    Info.CCEDiag(E, diag::note_constexpr_var_init_non_constant,
-                 Notes.size() + 1) << VD;
-    Info.Note(VD->getLocation(), diag::note_declared_at);
-    Info.addNotes(Notes);
-  }
-
-  Result = VD->getEvaluatedValue();
-  return true;
-}
-
-static bool IsConstNonVolatile(QualType T) {
-  Qualifiers Quals = T.getQualifiers();
-  return Quals.hasConst() && !Quals.hasVolatile();
-}
-
-/// Get the base index of the given base class within an APValue representing
-/// the given derived class.
-static unsigned getBaseIndex(const CXXRecordDecl *Derived,
-                             const CXXRecordDecl *Base) {
-  Base = Base->getCanonicalDecl();
-  unsigned Index = 0;
-  for (CXXRecordDecl::base_class_const_iterator I = Derived->bases_begin(),
-         E = Derived->bases_end(); I != E; ++I, ++Index) {
-    if (I->getType()->getAsCXXRecordDecl()->getCanonicalDecl() == Base)
-      return Index;
-  }
-
-  llvm_unreachable("base class missing from derived class's bases list");
-}
-
-/// Extract the value of a character from a string literal.
-static APSInt extractStringLiteralCharacter(EvalInfo &Info, const Expr *Lit,
-                                            uint64_t Index) {
-  // FIXME: Support MakeStringConstant
-  if (const auto *ObjCEnc = dyn_cast<ObjCEncodeExpr>(Lit)) {
-    std::string Str;
-    Info.Ctx.getObjCEncodingForType(ObjCEnc->getEncodedType(), Str);
-    assert(Index <= Str.size() && "Index too large");
-    return APSInt::getUnsigned(Str.c_str()[Index]);
-  }
-
-  if (auto PE = dyn_cast<PredefinedExpr>(Lit))
-    Lit = PE->getFunctionName();
-  const StringLiteral *S = cast<StringLiteral>(Lit);
-  const ConstantArrayType *CAT =
-      Info.Ctx.getAsConstantArrayType(S->getType());
-  assert(CAT && "string literal isn't an array");
-  QualType CharType = CAT->getElementType();
-  assert(CharType->isIntegerType() && "unexpected character type");
-
-  APSInt Value(S->getCharByteWidth() * Info.Ctx.getCharWidth(),
-               CharType->isUnsignedIntegerType());
-  if (Index < S->getLength())
-    Value = S->getCodeUnit(Index);
-  return Value;
-}
-
-// Expand a string literal into an array of characters.
-static void expandStringLiteral(EvalInfo &Info, const Expr *Lit,
-                                APValue &Result) {
-  const StringLiteral *S = cast<StringLiteral>(Lit);
-  const ConstantArrayType *CAT =
-      Info.Ctx.getAsConstantArrayType(S->getType());
-  assert(CAT && "string literal isn't an array");
-  QualType CharType = CAT->getElementType();
-  assert(CharType->isIntegerType() && "unexpected character type");
-
-  unsigned Elts = CAT->getSize().getZExtValue();
-  Result = APValue(APValue::UninitArray(),
-                   std::min(S->getLength(), Elts), Elts);
-  APSInt Value(S->getCharByteWidth() * Info.Ctx.getCharWidth(),
-               CharType->isUnsignedIntegerType());
-  if (Result.hasArrayFiller())
-    Result.getArrayFiller() = APValue(Value);
-  for (unsigned I = 0, N = Result.getArrayInitializedElts(); I != N; ++I) {
-    Value = S->getCodeUnit(I);
-    Result.getArrayInitializedElt(I) = APValue(Value);
-  }
-}
-
-// Expand an array so that it has more than Index filled elements.
-static void expandArray(APValue &Array, unsigned Index) {
-  unsigned Size = Array.getArraySize();
-  assert(Index < Size);
-
-  // Always at least double the number of elements for which we store a value.
-  unsigned OldElts = Array.getArrayInitializedElts();
-  unsigned NewElts = std::max(Index+1, OldElts * 2);
-  NewElts = std::min(Size, std::max(NewElts, 8u));
-
-  // Copy the data across.
-  APValue NewValue(APValue::UninitArray(), NewElts, Size);
-  for (unsigned I = 0; I != OldElts; ++I)
-    NewValue.getArrayInitializedElt(I).swap(Array.getArrayInitializedElt(I));
-  for (unsigned I = OldElts; I != NewElts; ++I)
-    NewValue.getArrayInitializedElt(I) = Array.getArrayFiller();
-  if (NewValue.hasArrayFiller())
-    NewValue.getArrayFiller() = Array.getArrayFiller();
-  Array.swap(NewValue);
-}
-
-/// Determine whether a type would actually be read by an lvalue-to-rvalue
-/// conversion. If it's of class type, we may assume that the copy operation
-/// is trivial. Note that this is never true for a union type with fields
-/// (because the copy always "reads" the active member) and always true for
-/// a non-class type.
-static bool isReadByLvalueToRvalueConversion(QualType T) {
-  CXXRecordDecl *RD = T->getBaseElementTypeUnsafe()->getAsCXXRecordDecl();
-  if (!RD || (RD->isUnion() && !RD->field_empty()))
-    return true;
-  if (RD->isEmpty())
-    return false;
-
-  for (auto *Field : RD->fields())
-    if (isReadByLvalueToRvalueConversion(Field->getType()))
-      return true;
-
-  for (auto &BaseSpec : RD->bases())
-    if (isReadByLvalueToRvalueConversion(BaseSpec.getType()))
-      return true;
-
-  return false;
-}
-
-/// Diagnose an attempt to read from any unreadable field within the specified
-/// type, which might be a class type.
-static bool diagnoseUnreadableFields(EvalInfo &Info, const Expr *E,
-                                     QualType T) {
-  CXXRecordDecl *RD = T->getBaseElementTypeUnsafe()->getAsCXXRecordDecl();
-  if (!RD)
-    return false;
-
-  if (!RD->hasMutableFields())
-    return false;
-
-  for (auto *Field : RD->fields()) {
-    // If we're actually going to read this field in some way, then it can't
-    // be mutable. If we're in a union, then assigning to a mutable field
-    // (even an empty one) can change the active member, so that's not OK.
-    // FIXME: Add core issue number for the union case.
-    if (Field->isMutable() &&
-        (RD->isUnion() || isReadByLvalueToRvalueConversion(Field->getType()))) {
-      Info.FFDiag(E, diag::note_constexpr_ltor_mutable, 1) << Field;
-      Info.Note(Field->getLocation(), diag::note_declared_at);
-      return true;
-    }
-
-    if (diagnoseUnreadableFields(Info, E, Field->getType()))
-      return true;
-  }
-
-  for (auto &BaseSpec : RD->bases())
-    if (diagnoseUnreadableFields(Info, E, BaseSpec.getType()))
-      return true;
-
-  // All mutable fields were empty, and thus not actually read.
-  return false;
-}
-
-namespace {
-/// A handle to a complete object (an object that is not a subobject of
-/// another object).
-struct CompleteObject {
-  /// The value of the complete object.
-  APValue *Value;
-  /// The type of the complete object.
-  QualType Type;
-  bool LifetimeStartedInEvaluation;
-
-  CompleteObject() : Value(nullptr) {}
-  CompleteObject(APValue *Value, QualType Type,
-                 bool LifetimeStartedInEvaluation)
-      : Value(Value), Type(Type),
-        LifetimeStartedInEvaluation(LifetimeStartedInEvaluation) {
-    assert(Value && "missing value for complete object");
-  }
-
-  explicit operator bool() const { return Value; }
-};
-} // end anonymous namespace
-
-/// Find the designated sub-object of an rvalue.
-template<typename SubobjectHandler>
-typename SubobjectHandler::result_type
-findSubobject(EvalInfo &Info, const Expr *E, const CompleteObject &Obj,
-              const SubobjectDesignator &Sub, SubobjectHandler &handler) {
-  if (Sub.Invalid)
-    // A diagnostic will have already been produced.
-    return handler.failed();
-  if (Sub.isOnePastTheEnd() || Sub.isMostDerivedAnUnsizedArray()) {
-    if (Info.getLangOpts().CPlusPlus11)
-      Info.FFDiag(E, Sub.isOnePastTheEnd()
-                         ? diag::note_constexpr_access_past_end
-                         : diag::note_constexpr_access_unsized_array)
-          << handler.AccessKind;
-    else
-      Info.FFDiag(E);
-    return handler.failed();
-  }
-
-  APValue *O = Obj.Value;
-  QualType ObjType = Obj.Type;
-  const FieldDecl *LastField = nullptr;
-  const bool MayReadMutableMembers =
-      Obj.LifetimeStartedInEvaluation && Info.getLangOpts().CPlusPlus14;
-
-  // Walk the designator's path to find the subobject.
-  for (unsigned I = 0, N = Sub.Entries.size(); /**/; ++I) {
-    if (O->isUninit()) {
-      if (!Info.checkingPotentialConstantExpression())
-        Info.FFDiag(E, diag::note_constexpr_access_uninit) << handler.AccessKind;
-      return handler.failed();
-    }
-
-    if (I == N) {
-      // If we are reading an object of class type, there may still be more
-      // things we need to check: if there are any mutable subobjects, we
-      // cannot perform this read. (This only happens when performing a trivial
-      // copy or assignment.)
-      if (ObjType->isRecordType() && handler.AccessKind == AK_Read &&
-          !MayReadMutableMembers && diagnoseUnreadableFields(Info, E, ObjType))
-        return handler.failed();
-
-      if (!handler.found(*O, ObjType))
-        return false;
-
-      // If we modified a bit-field, truncate it to the right width.
-      if (handler.AccessKind != AK_Read &&
-          LastField && LastField->isBitField() &&
-          !truncateBitfieldValue(Info, E, *O, LastField))
-        return false;
-
-      return true;
-    }
-
-    LastField = nullptr;
-    if (ObjType->isArrayType()) {
-      // Next subobject is an array element.
-      const ConstantArrayType *CAT = Info.Ctx.getAsConstantArrayType(ObjType);
-      assert(CAT && "vla in literal type?");
-      uint64_t Index = Sub.Entries[I].ArrayIndex;
-      if (CAT->getSize().ule(Index)) {
-        // Note, it should not be possible to form a pointer with a valid
-        // designator which points more than one past the end of the array.
-        if (Info.getLangOpts().CPlusPlus11)
-          Info.FFDiag(E, diag::note_constexpr_access_past_end)
-            << handler.AccessKind;
-        else
-          Info.FFDiag(E);
-        return handler.failed();
-      }
-
-      ObjType = CAT->getElementType();
-
-      // An array object is represented as either an Array APValue or as an
-      // LValue which refers to a string literal.
-      if (O->isLValue()) {
-        assert(I == N - 1 && "extracting subobject of character?");
-        assert(!O->hasLValuePath() || O->getLValuePath().empty());
-        if (handler.AccessKind != AK_Read)
-          expandStringLiteral(Info, O->getLValueBase().get<const Expr *>(),
-                              *O);
-        else
-          return handler.foundString(*O, ObjType, Index);
-      }
-
-      if (O->getArrayInitializedElts() > Index)
-        O = &O->getArrayInitializedElt(Index);
-      else if (handler.AccessKind != AK_Read) {
-        expandArray(*O, Index);
-        O = &O->getArrayInitializedElt(Index);
-      } else
-        O = &O->getArrayFiller();
-    } else if (ObjType->isAnyComplexType()) {
-      // Next subobject is a complex number.
-      uint64_t Index = Sub.Entries[I].ArrayIndex;
-      if (Index > 1) {
-        if (Info.getLangOpts().CPlusPlus11)
-          Info.FFDiag(E, diag::note_constexpr_access_past_end)
-            << handler.AccessKind;
-        else
-          Info.FFDiag(E);
-        return handler.failed();
-      }
-
-      bool WasConstQualified = ObjType.isConstQualified();
-      ObjType = ObjType->castAs<ComplexType>()->getElementType();
-      if (WasConstQualified)
-        ObjType.addConst();
-
-      assert(I == N - 1 && "extracting subobject of scalar?");
-      if (O->isComplexInt()) {
-        return handler.found(Index ? O->getComplexIntImag()
-                                   : O->getComplexIntReal(), ObjType);
-      } else {
-        assert(O->isComplexFloat());
-        return handler.found(Index ? O->getComplexFloatImag()
-                                   : O->getComplexFloatReal(), ObjType);
-      }
-    } else if (const FieldDecl *Field = getAsField(Sub.Entries[I])) {
-      // In C++14 onwards, it is permitted to read a mutable member whose
-      // lifetime began within the evaluation.
-      // FIXME: Should we also allow this in C++11?
-      if (Field->isMutable() && handler.AccessKind == AK_Read &&
-          !MayReadMutableMembers) {
-        Info.FFDiag(E, diag::note_constexpr_ltor_mutable, 1)
-          << Field;
-        Info.Note(Field->getLocation(), diag::note_declared_at);
-        return handler.failed();
-      }
-
-      // Next subobject is a class, struct or union field.
-      RecordDecl *RD = ObjType->castAs<RecordType>()->getDecl();
-      if (RD->isUnion()) {
-        const FieldDecl *UnionField = O->getUnionField();
-        if (!UnionField ||
-            UnionField->getCanonicalDecl() != Field->getCanonicalDecl()) {
-          Info.FFDiag(E, diag::note_constexpr_access_inactive_union_member)
-            << handler.AccessKind << Field << !UnionField << UnionField;
-          return handler.failed();
-        }
-        O = &O->getUnionValue();
-      } else
-        O = &O->getStructField(Field->getFieldIndex());
-
-      bool WasConstQualified = ObjType.isConstQualified();
-      ObjType = Field->getType();
-      if (WasConstQualified && !Field->isMutable())
-        ObjType.addConst();
-
-      if (ObjType.isVolatileQualified()) {
-        if (Info.getLangOpts().CPlusPlus) {
-          // FIXME: Include a description of the path to the volatile subobject.
-          Info.FFDiag(E, diag::note_constexpr_access_volatile_obj, 1)
-            << handler.AccessKind << 2 << Field;
-          Info.Note(Field->getLocation(), diag::note_declared_at);
-        } else {
-          Info.FFDiag(E, diag::note_invalid_subexpr_in_const_expr);
-        }
-        return handler.failed();
-      }
-
-      LastField = Field;
-    } else {
-      // Next subobject is a base class.
-      const CXXRecordDecl *Derived = ObjType->getAsCXXRecordDecl();
-      const CXXRecordDecl *Base = getAsBaseClass(Sub.Entries[I]);
-      O = &O->getStructBase(getBaseIndex(Derived, Base));
-
-      bool WasConstQualified = ObjType.isConstQualified();
-      ObjType = Info.Ctx.getRecordType(Base);
-      if (WasConstQualified)
-        ObjType.addConst();
-    }
-  }
-}
-
-namespace {
-struct ExtractSubobjectHandler {
-  EvalInfo &Info;
-  APValue &Result;
-
-  static const AccessKinds AccessKind = AK_Read;
-
-  typedef bool result_type;
-  bool failed() { return false; }
-  bool found(APValue &Subobj, QualType SubobjType) {
-    Result = Subobj;
-    return true;
-  }
-  bool found(APSInt &Value, QualType SubobjType) {
-    Result = APValue(Value);
-    return true;
-  }
-  bool found(APFloat &Value, QualType SubobjType) {
-    Result = APValue(Value);
-    return true;
-  }
-  bool foundString(APValue &Subobj, QualType SubobjType, uint64_t Character) {
-    Result = APValue(extractStringLiteralCharacter(
-        Info, Subobj.getLValueBase().get<const Expr *>(), Character));
-    return true;
-  }
-};
-} // end anonymous namespace
-
-const AccessKinds ExtractSubobjectHandler::AccessKind;
-
-/// Extract the designated sub-object of an rvalue.
-static bool extractSubobject(EvalInfo &Info, const Expr *E,
-                             const CompleteObject &Obj,
-                             const SubobjectDesignator &Sub,
-                             APValue &Result) {
-  ExtractSubobjectHandler Handler = { Info, Result };
-  return findSubobject(Info, E, Obj, Sub, Handler);
-}
-
-namespace {
-struct ModifySubobjectHandler {
-  EvalInfo &Info;
-  APValue &NewVal;
-  const Expr *E;
-
-  typedef bool result_type;
-  static const AccessKinds AccessKind = AK_Assign;
-
-  bool checkConst(QualType QT) {
-    // Assigning to a const object has undefined behavior.
-    if (QT.isConstQualified()) {
-      Info.FFDiag(E, diag::note_constexpr_modify_const_type) << QT;
-      return false;
-    }
-    return true;
-  }
-
-  bool failed() { return false; }
-  bool found(APValue &Subobj, QualType SubobjType) {
-    if (!checkConst(SubobjType))
-      return false;
-    // We've been given ownership of NewVal, so just swap it in.
-    Subobj.swap(NewVal);
-    return true;
-  }
-  bool found(APSInt &Value, QualType SubobjType) {
-    if (!checkConst(SubobjType))
-      return false;
-    if (!NewVal.isInt()) {
-      // Maybe trying to write a cast pointer value into a complex?
-      Info.FFDiag(E);
-      return false;
-    }
-    Value = NewVal.getInt();
-    return true;
-  }
-  bool found(APFloat &Value, QualType SubobjType) {
-    if (!checkConst(SubobjType))
-      return false;
-    Value = NewVal.getFloat();
-    return true;
-  }
-  bool foundString(APValue &Subobj, QualType SubobjType, uint64_t Character) {
-    llvm_unreachable("shouldn't encounter string elements with ExpandArrays");
-  }
-};
-} // end anonymous namespace
-
-const AccessKinds ModifySubobjectHandler::AccessKind;
-
-/// Update the designated sub-object of an rvalue to the given value.
-static bool modifySubobject(EvalInfo &Info, const Expr *E,
-                            const CompleteObject &Obj,
-                            const SubobjectDesignator &Sub,
-                            APValue &NewVal) {
-  ModifySubobjectHandler Handler = { Info, NewVal, E };
-  return findSubobject(Info, E, Obj, Sub, Handler);
-}
-
-/// Find the position where two subobject designators diverge, or equivalently
-/// the length of the common initial subsequence.
-static unsigned FindDesignatorMismatch(QualType ObjType,
-                                       const SubobjectDesignator &A,
-                                       const SubobjectDesignator &B,
-                                       bool &WasArrayIndex) {
-  unsigned I = 0, N = std::min(A.Entries.size(), B.Entries.size());
-  for (/**/; I != N; ++I) {
-    if (!ObjType.isNull() &&
-        (ObjType->isArrayType() || ObjType->isAnyComplexType())) {
-      // Next subobject is an array element.
-      if (A.Entries[I].ArrayIndex != B.Entries[I].ArrayIndex) {
-        WasArrayIndex = true;
-        return I;
-      }
-      if (ObjType->isAnyComplexType())
-        ObjType = ObjType->castAs<ComplexType>()->getElementType();
-      else
-        ObjType = ObjType->castAsArrayTypeUnsafe()->getElementType();
-    } else {
-      if (A.Entries[I].BaseOrMember != B.Entries[I].BaseOrMember) {
-        WasArrayIndex = false;
-        return I;
-      }
-      if (const FieldDecl *FD = getAsField(A.Entries[I]))
-        // Next subobject is a field.
-        ObjType = FD->getType();
-      else
-        // Next subobject is a base class.
-        ObjType = QualType();
-    }
-  }
-  WasArrayIndex = false;
-  return I;
-}
-
-/// Determine whether the given subobject designators refer to elements of the
-/// same array object.
-static bool AreElementsOfSameArray(QualType ObjType,
-                                   const SubobjectDesignator &A,
-                                   const SubobjectDesignator &B) {
-  if (A.Entries.size() != B.Entries.size())
-    return false;
-
-  bool IsArray = A.MostDerivedIsArrayElement;
-  if (IsArray && A.MostDerivedPathLength != A.Entries.size())
-    // A is a subobject of the array element.
-    return false;
-
-  // If A (and B) designates an array element, the last entry will be the array
-  // index. That doesn't have to match. Otherwise, we're in the 'implicit array
-  // of length 1' case, and the entire path must match.
-  bool WasArrayIndex;
-  unsigned CommonLength = FindDesignatorMismatch(ObjType, A, B, WasArrayIndex);
-  return CommonLength >= A.Entries.size() - IsArray;
-}
-
-/// Find the complete object to which an LValue refers.
-static CompleteObject findCompleteObject(EvalInfo &Info, const Expr *E,
-                                         AccessKinds AK, const LValue &LVal,
-                                         QualType LValType) {
-  if (!LVal.Base) {
-    Info.FFDiag(E, diag::note_constexpr_access_null) << AK;
-    return CompleteObject();
-  }
-
-  CallStackFrame *Frame = nullptr;
-  if (LVal.getLValueCallIndex()) {
-    Frame = Info.getCallFrame(LVal.getLValueCallIndex());
-    if (!Frame) {
-      Info.FFDiag(E, diag::note_constexpr_lifetime_ended, 1)
-        << AK << LVal.Base.is<const ValueDecl*>();
-      NoteLValueLocation(Info, LVal.Base);
-      return CompleteObject();
-    }
-  }
-
-  // C++11 DR1311: An lvalue-to-rvalue conversion on a volatile-qualified type
-  // is not a constant expression (even if the object is non-volatile). We also
-  // apply this rule to C++98, in order to conform to the expected 'volatile'
-  // semantics.
-  if (LValType.isVolatileQualified()) {
-    if (Info.getLangOpts().CPlusPlus)
-      Info.FFDiag(E, diag::note_constexpr_access_volatile_type)
-        << AK << LValType;
-    else
-      Info.FFDiag(E);
-    return CompleteObject();
-  }
-
-  // Compute value storage location and type of base object.
-  APValue *BaseVal = nullptr;
-  QualType BaseType = getType(LVal.Base);
-  bool LifetimeStartedInEvaluation = Frame;
-
-  if (const ValueDecl *D = LVal.Base.dyn_cast<const ValueDecl*>()) {
-    // In C++98, const, non-volatile integers initialized with ICEs are ICEs.
-    // In C++11, constexpr, non-volatile variables initialized with constant
-    // expressions are constant expressions too. Inside constexpr functions,
-    // parameters are constant expressions even if they're non-const.
-    // In C++1y, objects local to a constant expression (those with a Frame) are
-    // both readable and writable inside constant expressions.
-    // In C, such things can also be folded, although they are not ICEs.
-    const VarDecl *VD = dyn_cast<VarDecl>(D);
-    if (VD) {
-      if (const VarDecl *VDef = VD->getDefinition(Info.Ctx))
-        VD = VDef;
-    }
-    if (!VD || VD->isInvalidDecl()) {
-      Info.FFDiag(E);
-      return CompleteObject();
-    }
-
-    // Accesses of volatile-qualified objects are not allowed.
-    if (BaseType.isVolatileQualified()) {
-      if (Info.getLangOpts().CPlusPlus) {
-        Info.FFDiag(E, diag::note_constexpr_access_volatile_obj, 1)
-          << AK << 1 << VD;
-        Info.Note(VD->getLocation(), diag::note_declared_at);
-      } else {
-        Info.FFDiag(E);
-      }
-      return CompleteObject();
-    }
-
-    // Unless we're looking at a local variable or argument in a constexpr call,
-    // the variable we're reading must be const.
-    if (!Frame) {
-      if (Info.getLangOpts().CPlusPlus14 &&
-          VD == Info.EvaluatingDecl.dyn_cast<const ValueDecl *>()) {
-        // OK, we can read and modify an object if we're in the process of
-        // evaluating its initializer, because its lifetime began in this
-        // evaluation.
-      } else if (AK != AK_Read) {
-        // All the remaining cases only permit reading.
-        Info.FFDiag(E, diag::note_constexpr_modify_global);
-        return CompleteObject();
-      } else if (VD->isConstexpr()) {
-        // OK, we can read this variable.
-      } else if (BaseType->isIntegralOrEnumerationType()) {
-        // In OpenCL if a variable is in constant address space it is a const value.
-        if (!(BaseType.isConstQualified() ||
-              (Info.getLangOpts().OpenCL &&
-               BaseType.getAddressSpace() == LangAS::opencl_constant))) {
-          if (Info.getLangOpts().CPlusPlus) {
-            Info.FFDiag(E, diag::note_constexpr_ltor_non_const_int, 1) << VD;
-            Info.Note(VD->getLocation(), diag::note_declared_at);
-          } else {
-            Info.FFDiag(E);
-          }
-          return CompleteObject();
-        }
-      } else if (BaseType->isFloatingType() && BaseType.isConstQualified()) {
-        // We support folding of const floating-point types, in order to make
-        // static const data members of such types (supported as an extension)
-        // more useful.
-        if (Info.getLangOpts().CPlusPlus11) {
-          Info.CCEDiag(E, diag::note_constexpr_ltor_non_constexpr, 1) << VD;
-          Info.Note(VD->getLocation(), diag::note_declared_at);
-        } else {
-          Info.CCEDiag(E);
-        }
-      } else if (BaseType.isConstQualified() && VD->hasDefinition(Info.Ctx)) {
-        Info.CCEDiag(E, diag::note_constexpr_ltor_non_constexpr) << VD;
-        // Keep evaluating to see what we can do.
-      } else {
-        // FIXME: Allow folding of values of any literal type in all languages.
-        if (Info.checkingPotentialConstantExpression() &&
-            VD->getType().isConstQualified() && !VD->hasDefinition(Info.Ctx)) {
-          // The definition of this variable could be constexpr. We can't
-          // access it right now, but may be able to in future.
-        } else if (Info.getLangOpts().CPlusPlus11) {
-          Info.FFDiag(E, diag::note_constexpr_ltor_non_constexpr, 1) << VD;
-          Info.Note(VD->getLocation(), diag::note_declared_at);
-        } else {
-          Info.FFDiag(E);
-        }
-        return CompleteObject();
-      }
-    }
-
-    if (!evaluateVarDeclInit(Info, E, VD, Frame, BaseVal, &LVal))
-      return CompleteObject();
-  } else {
-    const Expr *Base = LVal.Base.dyn_cast<const Expr*>();
-
-    if (!Frame) {
-      if (const MaterializeTemporaryExpr *MTE =
-              dyn_cast<MaterializeTemporaryExpr>(Base)) {
-        assert(MTE->getStorageDuration() == SD_Static &&
-               "should have a frame for a non-global materialized temporary");
-
-        // Per C++1y [expr.const]p2:
-        //  an lvalue-to-rvalue conversion [is not allowed unless it applies to]
-        //   - a [...] glvalue of integral or enumeration type that refers to
-        //     a non-volatile const object [...]
-        //   [...]
-        //   - a [...] glvalue of literal type that refers to a non-volatile
-        //     object whose lifetime began within the evaluation of e.
-        //
-        // C++11 misses the 'began within the evaluation of e' check and
-        // instead allows all temporaries, including things like:
-        //   int &&r = 1;
-        //   int x = ++r;
-        //   constexpr int k = r;
-        // Therefore we use the C++14 rules in C++11 too.
-        const ValueDecl *VD = Info.EvaluatingDecl.dyn_cast<const ValueDecl*>();
-        const ValueDecl *ED = MTE->getExtendingDecl();
-        if (!(BaseType.isConstQualified() &&
-              BaseType->isIntegralOrEnumerationType()) &&
-            !(VD && VD->getCanonicalDecl() == ED->getCanonicalDecl())) {
-          Info.FFDiag(E, diag::note_constexpr_access_static_temporary, 1) << AK;
-          Info.Note(MTE->getExprLoc(), diag::note_constexpr_temporary_here);
-          return CompleteObject();
-        }
-
-        BaseVal = Info.Ctx.getMaterializedTemporaryValue(MTE, false);
-        assert(BaseVal && "got reference to unevaluated temporary");
-        LifetimeStartedInEvaluation = true;
-      } else {
-        Info.FFDiag(E);
-        return CompleteObject();
-      }
-    } else {
-      BaseVal = Frame->getTemporary(Base, LVal.Base.getVersion());
-      assert(BaseVal && "missing value for temporary");
-    }
-
-    // Volatile temporary objects cannot be accessed in constant expressions.
-    if (BaseType.isVolatileQualified()) {
-      if (Info.getLangOpts().CPlusPlus) {
-        Info.FFDiag(E, diag::note_constexpr_access_volatile_obj, 1)
-          << AK << 0;
-        Info.Note(Base->getExprLoc(), diag::note_constexpr_temporary_here);
-      } else {
-        Info.FFDiag(E);
-      }
-      return CompleteObject();
-    }
-  }
-
-  // During the construction of an object, it is not yet 'const'.
-  // FIXME: This doesn't do quite the right thing for const subobjects of the
-  // object under construction.
-  if (Info.isEvaluatingConstructor(LVal.getLValueBase(),
-                                   LVal.getLValueCallIndex(),
-                                   LVal.getLValueVersion())) {
-    BaseType = Info.Ctx.getCanonicalType(BaseType);
-    BaseType.removeLocalConst();
-    LifetimeStartedInEvaluation = true;
-  }
-
-  // In C++14, we can't safely access any mutable state when we might be
-  // evaluating after an unmodeled side effect.
-  //
-  // FIXME: Not all local state is mutable. Allow local constant subobjects
-  // to be read here (but take care with 'mutable' fields).
-  if ((Frame && Info.getLangOpts().CPlusPlus14 &&
-       Info.EvalStatus.HasSideEffects) ||
-      (AK != AK_Read && Info.IsSpeculativelyEvaluating))
-    return CompleteObject();
-
-  return CompleteObject(BaseVal, BaseType, LifetimeStartedInEvaluation);
-}
-
-/// Perform an lvalue-to-rvalue conversion on the given glvalue. This
-/// can also be used for 'lvalue-to-lvalue' conversions for looking up the
-/// glvalue referred to by an entity of reference type.
-///
-/// \param Info - Information about the ongoing evaluation.
-/// \param Conv - The expression for which we are performing the conversion.
-///               Used for diagnostics.
-/// \param Type - The type of the glvalue (before stripping cv-qualifiers in the
-///               case of a non-class type).
-/// \param LVal - The glvalue on which we are attempting to perform this action.
-/// \param RVal - The produced value will be placed here.
-static bool handleLValueToRValueConversion(EvalInfo &Info, const Expr *Conv,
-                                           QualType Type,
-                                           const LValue &LVal, APValue &RVal) {
-  if (LVal.Designator.Invalid)
-    return false;
-
-  // Check for special cases where there is no existing APValue to look at.
-  const Expr *Base = LVal.Base.dyn_cast<const Expr*>();
-  if (Base && !LVal.getLValueCallIndex() && !Type.isVolatileQualified()) {
-    if (const CompoundLiteralExpr *CLE = dyn_cast<CompoundLiteralExpr>(Base)) {
-      // In C99, a CompoundLiteralExpr is an lvalue, and we defer evaluating the
-      // initializer until now for such expressions. Such an expression can't be
-      // an ICE in C, so this only matters for fold.
-      if (Type.isVolatileQualified()) {
-        Info.FFDiag(Conv);
-        return false;
-      }
-      APValue Lit;
-      if (!Evaluate(Lit, Info, CLE->getInitializer()))
-        return false;
-      CompleteObject LitObj(&Lit, Base->getType(), false);
-      return extractSubobject(Info, Conv, LitObj, LVal.Designator, RVal);
-    } else if (isa<StringLiteral>(Base) || isa<PredefinedExpr>(Base)) {
-      // We represent a string literal array as an lvalue pointing at the
-      // corresponding expression, rather than building an array of chars.
-      // FIXME: Support ObjCEncodeExpr, MakeStringConstant
-      APValue Str(Base, CharUnits::Zero(), APValue::NoLValuePath(), 0);
-      CompleteObject StrObj(&Str, Base->getType(), false);
-      return extractSubobject(Info, Conv, StrObj, LVal.Designator, RVal);
-    }
-  }
-
-  CompleteObject Obj = findCompleteObject(Info, Conv, AK_Read, LVal, Type);
-  return Obj && extractSubobject(Info, Conv, Obj, LVal.Designator, RVal);
-}
-
-/// Perform an assignment of Val to LVal. Takes ownership of Val.
-static bool handleAssignment(EvalInfo &Info, const Expr *E, const LValue &LVal,
-                             QualType LValType, APValue &Val) {
-  if (LVal.Designator.Invalid)
-    return false;
-
-  if (!Info.getLangOpts().CPlusPlus14) {
-    Info.FFDiag(E);
-    return false;
-  }
-
-  CompleteObject Obj = findCompleteObject(Info, E, AK_Assign, LVal, LValType);
-  return Obj && modifySubobject(Info, E, Obj, LVal.Designator, Val);
-}
-
-namespace {
-struct CompoundAssignSubobjectHandler {
-  EvalInfo &Info;
-  const Expr *E;
-  QualType PromotedLHSType;
-  BinaryOperatorKind Opcode;
-  const APValue &RHS;
-
-  static const AccessKinds AccessKind = AK_Assign;
-
-  typedef bool result_type;
-
-  bool checkConst(QualType QT) {
-    // Assigning to a const object has undefined behavior.
-    if (QT.isConstQualified()) {
-      Info.FFDiag(E, diag::note_constexpr_modify_const_type) << QT;
-      return false;
-    }
-    return true;
-  }
-
-  bool failed() { return false; }
-  bool found(APValue &Subobj, QualType SubobjType) {
-    switch (Subobj.getKind()) {
-    case APValue::Int:
-      return found(Subobj.getInt(), SubobjType);
-    case APValue::Float:
-      return found(Subobj.getFloat(), SubobjType);
-    case APValue::ComplexInt:
-    case APValue::ComplexFloat:
-      // FIXME: Implement complex compound assignment.
-      Info.FFDiag(E);
-      return false;
-    case APValue::LValue:
-      return foundPointer(Subobj, SubobjType);
-    default:
-      // FIXME: can this happen?
-      Info.FFDiag(E);
-      return false;
-    }
-  }
-  bool found(APSInt &Value, QualType SubobjType) {
-    if (!checkConst(SubobjType))
-      return false;
-
-    if (!SubobjType->isIntegerType()) {
-      // We don't support compound assignment on integer-cast-to-pointer
-      // values.
-      Info.FFDiag(E);
-      return false;
-    }
-
-    if (RHS.isInt()) {
-      APSInt LHS =
-          HandleIntToIntCast(Info, E, PromotedLHSType, SubobjType, Value);
-      if (!handleIntIntBinOp(Info, E, LHS, Opcode, RHS.getInt(), LHS))
-        return false;
-      Value = HandleIntToIntCast(Info, E, SubobjType, PromotedLHSType, LHS);
-      return true;
-    } else if (RHS.isFloat()) {
-      APFloat FValue(0.0);
-      return HandleIntToFloatCast(Info, E, SubobjType, Value, PromotedLHSType,
-                                  FValue) &&
-             handleFloatFloatBinOp(Info, E, FValue, Opcode, RHS.getFloat()) &&
-             HandleFloatToIntCast(Info, E, PromotedLHSType, FValue, SubobjType,
-                                  Value);
-    }
-
-    Info.FFDiag(E);
-    return false;
-  }
-  bool found(APFloat &Value, QualType SubobjType) {
-    return checkConst(SubobjType) &&
-           HandleFloatToFloatCast(Info, E, SubobjType, PromotedLHSType,
-                                  Value) &&
-           handleFloatFloatBinOp(Info, E, Value, Opcode, RHS.getFloat()) &&
-           HandleFloatToFloatCast(Info, E, PromotedLHSType, SubobjType, Value);
-  }
-  bool foundPointer(APValue &Subobj, QualType SubobjType) {
-    if (!checkConst(SubobjType))
-      return false;
-
-    QualType PointeeType;
-    if (const PointerType *PT = SubobjType->getAs<PointerType>())
-      PointeeType = PT->getPointeeType();
-
-    if (PointeeType.isNull() || !RHS.isInt() ||
-        (Opcode != BO_Add && Opcode != BO_Sub)) {
-      Info.FFDiag(E);
-      return false;
-    }
-
-    APSInt Offset = RHS.getInt();
-    if (Opcode == BO_Sub)
-      negateAsSigned(Offset);
-
-    LValue LVal;
-    LVal.setFrom(Info.Ctx, Subobj);
-    if (!HandleLValueArrayAdjustment(Info, E, LVal, PointeeType, Offset))
-      return false;
-    LVal.moveInto(Subobj);
-    return true;
-  }
-  bool foundString(APValue &Subobj, QualType SubobjType, uint64_t Character) {
-    llvm_unreachable("shouldn't encounter string elements here");
-  }
-};
-} // end anonymous namespace
-
-const AccessKinds CompoundAssignSubobjectHandler::AccessKind;
-
-/// Perform a compound assignment of LVal <op>= RVal.
-static bool handleCompoundAssignment(
-    EvalInfo &Info, const Expr *E,
-    const LValue &LVal, QualType LValType, QualType PromotedLValType,
-    BinaryOperatorKind Opcode, const APValue &RVal) {
-  if (LVal.Designator.Invalid)
-    return false;
-
-  if (!Info.getLangOpts().CPlusPlus14) {
-    Info.FFDiag(E);
-    return false;
-  }
-
-  CompleteObject Obj = findCompleteObject(Info, E, AK_Assign, LVal, LValType);
-  CompoundAssignSubobjectHandler Handler = { Info, E, PromotedLValType, Opcode,
-                                             RVal };
-  return Obj && findSubobject(Info, E, Obj, LVal.Designator, Handler);
-}
-
-namespace {
-struct IncDecSubobjectHandler {
-  EvalInfo &Info;
-  const UnaryOperator *E;
-  AccessKinds AccessKind;
-  APValue *Old;
-
-  typedef bool result_type;
-
-  bool checkConst(QualType QT) {
-    // Assigning to a const object has undefined behavior.
-    if (QT.isConstQualified()) {
-      Info.FFDiag(E, diag::note_constexpr_modify_const_type) << QT;
-      return false;
-    }
-    return true;
-  }
-
-  bool failed() { return false; }
-  bool found(APValue &Subobj, QualType SubobjType) {
-    // Stash the old value. Also clear Old, so we don't clobber it later
-    // if we're post-incrementing a complex.
-    if (Old) {
-      *Old = Subobj;
-      Old = nullptr;
-    }
-
-    switch (Subobj.getKind()) {
-    case APValue::Int:
-      return found(Subobj.getInt(), SubobjType);
-    case APValue::Float:
-      return found(Subobj.getFloat(), SubobjType);
-    case APValue::ComplexInt:
-      return found(Subobj.getComplexIntReal(),
-                   SubobjType->castAs<ComplexType>()->getElementType()
-                     .withCVRQualifiers(SubobjType.getCVRQualifiers()));
-    case APValue::ComplexFloat:
-      return found(Subobj.getComplexFloatReal(),
-                   SubobjType->castAs<ComplexType>()->getElementType()
-                     .withCVRQualifiers(SubobjType.getCVRQualifiers()));
-    case APValue::LValue:
-      return foundPointer(Subobj, SubobjType);
-    default:
-      // FIXME: can this happen?
-      Info.FFDiag(E);
-      return false;
-    }
-  }
-  bool found(APSInt &Value, QualType SubobjType) {
-    if (!checkConst(SubobjType))
-      return false;
-
-    if (!SubobjType->isIntegerType()) {
-      // We don't support increment / decrement on integer-cast-to-pointer
-      // values.
-      Info.FFDiag(E);
-      return false;
-    }
-
-    if (Old) *Old = APValue(Value);
-
-    // bool arithmetic promotes to int, and the conversion back to bool
-    // doesn't reduce mod 2^n, so special-case it.
-    if (SubobjType->isBooleanType()) {
-      if (AccessKind == AK_Increment)
-        Value = 1;
-      else
-        Value = !Value;
-      return true;
-    }
-
-    bool WasNegative = Value.isNegative();
-    if (AccessKind == AK_Increment) {
-      ++Value;
-
-      if (!WasNegative && Value.isNegative() && E->canOverflow()) {
-        APSInt ActualValue(Value, /*IsUnsigned*/true);
-        return HandleOverflow(Info, E, ActualValue, SubobjType);
-      }
-    } else {
-      --Value;
-
-      if (WasNegative && !Value.isNegative() && E->canOverflow()) {
-        unsigned BitWidth = Value.getBitWidth();
-        APSInt ActualValue(Value.sext(BitWidth + 1), /*IsUnsigned*/false);
-        ActualValue.setBit(BitWidth);
-        return HandleOverflow(Info, E, ActualValue, SubobjType);
-      }
-    }
-    return true;
-  }
-  bool found(APFloat &Value, QualType SubobjType) {
-    if (!checkConst(SubobjType))
-      return false;
-
-    if (Old) *Old = APValue(Value);
-
-    APFloat One(Value.getSemantics(), 1);
-    if (AccessKind == AK_Increment)
-      Value.add(One, APFloat::rmNearestTiesToEven);
-    else
-      Value.subtract(One, APFloat::rmNearestTiesToEven);
-    return true;
-  }
-  bool foundPointer(APValue &Subobj, QualType SubobjType) {
-    if (!checkConst(SubobjType))
-      return false;
-
-    QualType PointeeType;
-    if (const PointerType *PT = SubobjType->getAs<PointerType>())
-      PointeeType = PT->getPointeeType();
-    else {
-      Info.FFDiag(E);
-      return false;
-    }
-
-    LValue LVal;
-    LVal.setFrom(Info.Ctx, Subobj);
-    if (!HandleLValueArrayAdjustment(Info, E, LVal, PointeeType,
-                                     AccessKind == AK_Increment ? 1 : -1))
-      return false;
-    LVal.moveInto(Subobj);
-    return true;
-  }
-  bool foundString(APValue &Subobj, QualType SubobjType, uint64_t Character) {
-    llvm_unreachable("shouldn't encounter string elements here");
-  }
-};
-} // end anonymous namespace
-
-/// Perform an increment or decrement on LVal.
-static bool handleIncDec(EvalInfo &Info, const Expr *E, const LValue &LVal,
-                         QualType LValType, bool IsIncrement, APValue *Old) {
-  if (LVal.Designator.Invalid)
-    return false;
-
-  if (!Info.getLangOpts().CPlusPlus14) {
-    Info.FFDiag(E);
-    return false;
-  }
-
-  AccessKinds AK = IsIncrement ? AK_Increment : AK_Decrement;
-  CompleteObject Obj = findCompleteObject(Info, E, AK, LVal, LValType);
-  IncDecSubobjectHandler Handler = {Info, cast<UnaryOperator>(E), AK, Old};
-  return Obj && findSubobject(Info, E, Obj, LVal.Designator, Handler);
-}
-
-/// Build an lvalue for the object argument of a member function call.
-static bool EvaluateObjectArgument(EvalInfo &Info, const Expr *Object,
-                                   LValue &This) {
-  if (Object->getType()->isPointerType())
-    return EvaluatePointer(Object, This, Info);
-
-  if (Object->isGLValue())
-    return EvaluateLValue(Object, This, Info);
-
-  if (Object->getType()->isLiteralType(Info.Ctx))
-    return EvaluateTemporary(Object, This, Info);
-
-  Info.FFDiag(Object, diag::note_constexpr_nonliteral) << Object->getType();
-  return false;
-}
-
-/// HandleMemberPointerAccess - Evaluate a member access operation and build an
-/// lvalue referring to the result.
-///
-/// \param Info - Information about the ongoing evaluation.
-/// \param LV - An lvalue referring to the base of the member pointer.
-/// \param RHS - The member pointer expression.
-/// \param IncludeMember - Specifies whether the member itself is included in
-///        the resulting LValue subobject designator. This is not possible when
-///        creating a bound member function.
-/// \return The field or method declaration to which the member pointer refers,
-///         or 0 if evaluation fails.
-static const ValueDecl *HandleMemberPointerAccess(EvalInfo &Info,
-                                                  QualType LVType,
-                                                  LValue &LV,
-                                                  const Expr *RHS,
-                                                  bool IncludeMember = true) {
-  MemberPtr MemPtr;
-  if (!EvaluateMemberPointer(RHS, MemPtr, Info))
-    return nullptr;
-
-  // C++11 [expr.mptr.oper]p6: If the second operand is the null pointer to
-  // member value, the behavior is undefined.
-  if (!MemPtr.getDecl()) {
-    // FIXME: Specific diagnostic.
-    Info.FFDiag(RHS);
-    return nullptr;
-  }
-
-  if (MemPtr.isDerivedMember()) {
-    // This is a member of some derived class. Truncate LV appropriately.
-    // The end of the derived-to-base path for the base object must match the
-    // derived-to-base path for the member pointer.
-    if (LV.Designator.MostDerivedPathLength + MemPtr.Path.size() >
-        LV.Designator.Entries.size()) {
-      Info.FFDiag(RHS);
-      return nullptr;
-    }
-    unsigned PathLengthToMember =
-        LV.Designator.Entries.size() - MemPtr.Path.size();
-    for (unsigned I = 0, N = MemPtr.Path.size(); I != N; ++I) {
-      const CXXRecordDecl *LVDecl = getAsBaseClass(
-          LV.Designator.Entries[PathLengthToMember + I]);
-      const CXXRecordDecl *MPDecl = MemPtr.Path[I];
-      if (LVDecl->getCanonicalDecl() != MPDecl->getCanonicalDecl()) {
-        Info.FFDiag(RHS);
-        return nullptr;
-      }
-    }
-
-    // Truncate the lvalue to the appropriate derived class.
-    if (!CastToDerivedClass(Info, RHS, LV, MemPtr.getContainingRecord(),
-                            PathLengthToMember))
-      return nullptr;
-  } else if (!MemPtr.Path.empty()) {
-    // Extend the LValue path with the member pointer's path.
-    LV.Designator.Entries.reserve(LV.Designator.Entries.size() +
-                                  MemPtr.Path.size() + IncludeMember);
-
-    // Walk down to the appropriate base class.
-    if (const PointerType *PT = LVType->getAs<PointerType>())
-      LVType = PT->getPointeeType();
-    const CXXRecordDecl *RD = LVType->getAsCXXRecordDecl();
-    assert(RD && "member pointer access on non-class-type expression");
-    // The first class in the path is that of the lvalue.
-    for (unsigned I = 1, N = MemPtr.Path.size(); I != N; ++I) {
-      const CXXRecordDecl *Base = MemPtr.Path[N - I - 1];
-      if (!HandleLValueDirectBase(Info, RHS, LV, RD, Base))
-        return nullptr;
-      RD = Base;
-    }
-    // Finally cast to the class containing the member.
-    if (!HandleLValueDirectBase(Info, RHS, LV, RD,
-                                MemPtr.getContainingRecord()))
-      return nullptr;
-  }
-
-  // Add the member. Note that we cannot build bound member functions here.
-  if (IncludeMember) {
-    if (const FieldDecl *FD = dyn_cast<FieldDecl>(MemPtr.getDecl())) {
-      if (!HandleLValueMember(Info, RHS, LV, FD))
-        return nullptr;
-    } else if (const IndirectFieldDecl *IFD =
-                 dyn_cast<IndirectFieldDecl>(MemPtr.getDecl())) {
-      if (!HandleLValueIndirectMember(Info, RHS, LV, IFD))
-        return nullptr;
-    } else {
-      llvm_unreachable("can't construct reference to bound member function");
-    }
-  }
-
-  return MemPtr.getDecl();
-}
-
-static const ValueDecl *HandleMemberPointerAccess(EvalInfo &Info,
-                                                  const BinaryOperator *BO,
-                                                  LValue &LV,
-                                                  bool IncludeMember = true) {
-  assert(BO->getOpcode() == BO_PtrMemD || BO->getOpcode() == BO_PtrMemI);
-
-  if (!EvaluateObjectArgument(Info, BO->getLHS(), LV)) {
-    if (Info.noteFailure()) {
-      MemberPtr MemPtr;
-      EvaluateMemberPointer(BO->getRHS(), MemPtr, Info);
-    }
-    return nullptr;
-  }
-
-  return HandleMemberPointerAccess(Info, BO->getLHS()->getType(), LV,
-                                   BO->getRHS(), IncludeMember);
-}
-
-/// HandleBaseToDerivedCast - Apply the given base-to-derived cast operation on
-/// the provided lvalue, which currently refers to the base object.
-static bool HandleBaseToDerivedCast(EvalInfo &Info, const CastExpr *E,
-                                    LValue &Result) {
-  SubobjectDesignator &D = Result.Designator;
-  if (D.Invalid || !Result.checkNullPointer(Info, E, CSK_Derived))
-    return false;
-
-  QualType TargetQT = E->getType();
-  if (const PointerType *PT = TargetQT->getAs<PointerType>())
-    TargetQT = PT->getPointeeType();
-
-  // Check this cast lands within the final derived-to-base subobject path.
-  if (D.MostDerivedPathLength + E->path_size() > D.Entries.size()) {
-    Info.CCEDiag(E, diag::note_constexpr_invalid_downcast)
-      << D.MostDerivedType << TargetQT;
-    return false;
-  }
-
-  // Check the type of the final cast. We don't need to check the path,
-  // since a cast can only be formed if the path is unique.
-  unsigned NewEntriesSize = D.Entries.size() - E->path_size();
-  const CXXRecordDecl *TargetType = TargetQT->getAsCXXRecordDecl();
-  const CXXRecordDecl *FinalType;
-  if (NewEntriesSize == D.MostDerivedPathLength)
-    FinalType = D.MostDerivedType->getAsCXXRecordDecl();
-  else
-    FinalType = getAsBaseClass(D.Entries[NewEntriesSize - 1]);
-  if (FinalType->getCanonicalDecl() != TargetType->getCanonicalDecl()) {
-    Info.CCEDiag(E, diag::note_constexpr_invalid_downcast)
-      << D.MostDerivedType << TargetQT;
-    return false;
-  }
-
-  // Truncate the lvalue to the appropriate derived class.
-  return CastToDerivedClass(Info, E, Result, TargetType, NewEntriesSize);
-}
-
-namespace {
-enum EvalStmtResult {
-  /// Evaluation failed.
-  ESR_Failed,
-  /// Hit a 'return' statement.
-  ESR_Returned,
-  /// Evaluation succeeded.
-  ESR_Succeeded,
-  /// Hit a 'continue' statement.
-  ESR_Continue,
-  /// Hit a 'break' statement.
-  ESR_Break,
-  /// Still scanning for 'case' or 'default' statement.
-  ESR_CaseNotFound
-};
-}
-
-static bool EvaluateVarDecl(EvalInfo &Info, const VarDecl *VD) {
-  // We don't need to evaluate the initializer for a static local.
-  if (!VD->hasLocalStorage())
-    return true;
-
-  LValue Result;
-  APValue &Val = createTemporary(VD, true, Result, *Info.CurrentCall);
-
-  const Expr *InitE = VD->getInit();
-  if (!InitE) {
-    Info.FFDiag(VD->getBeginLoc(), diag::note_constexpr_uninitialized)
-        << false << VD->getType();
-    Val = APValue();
-    return false;
-  }
-
-  if (InitE->isValueDependent())
-    return false;
-
-  if (!EvaluateInPlace(Val, Info, Result, InitE)) {
-    // Wipe out any partially-computed value, to allow tracking that this
-    // evaluation failed.
-    Val = APValue();
-    return false;
-  }
-
-  return true;
-}
-
-static bool EvaluateDecl(EvalInfo &Info, const Decl *D) {
-  bool OK = true;
-
-  if (const VarDecl *VD = dyn_cast<VarDecl>(D))
-    OK &= EvaluateVarDecl(Info, VD);
-
-  if (const DecompositionDecl *DD = dyn_cast<DecompositionDecl>(D))
-    for (auto *BD : DD->bindings())
-      if (auto *VD = BD->getHoldingVar())
-        OK &= EvaluateDecl(Info, VD);
-
-  return OK;
-}
-
-
-/// Evaluate a condition (either a variable declaration or an expression).
-static bool EvaluateCond(EvalInfo &Info, const VarDecl *CondDecl,
-                         const Expr *Cond, bool &Result) {
-  FullExpressionRAII Scope(Info);
-  if (CondDecl && !EvaluateDecl(Info, CondDecl))
-    return false;
-  return EvaluateAsBooleanCondition(Cond, Result, Info);
-}
-
-namespace {
-/// A location where the result (returned value) of evaluating a
-/// statement should be stored.
-struct StmtResult {
-  /// The APValue that should be filled in with the returned value.
-  APValue &Value;
-  /// The location containing the result, if any (used to support RVO).
-  const LValue *Slot;
-};
-
-struct TempVersionRAII {
-  CallStackFrame &Frame;
-
-  TempVersionRAII(CallStackFrame &Frame) : Frame(Frame) {
-    Frame.pushTempVersion();
-  }
-
-  ~TempVersionRAII() {
-    Frame.popTempVersion();
-  }
-};
-
-}
-
-static EvalStmtResult EvaluateStmt(StmtResult &Result, EvalInfo &Info,
-                                   const Stmt *S,
-                                   const SwitchCase *SC = nullptr);
-
-/// Evaluate the body of a loop, and translate the result as appropriate.
-static EvalStmtResult EvaluateLoopBody(StmtResult &Result, EvalInfo &Info,
-                                       const Stmt *Body,
-                                       const SwitchCase *Case = nullptr) {
-  BlockScopeRAII Scope(Info);
-  switch (EvalStmtResult ESR = EvaluateStmt(Result, Info, Body, Case)) {
-  case ESR_Break:
-    return ESR_Succeeded;
-  case ESR_Succeeded:
-  case ESR_Continue:
-    return ESR_Continue;
-  case ESR_Failed:
-  case ESR_Returned:
-  case ESR_CaseNotFound:
-    return ESR;
-  }
-  llvm_unreachable("Invalid EvalStmtResult!");
-}
-
-/// Evaluate a switch statement.
-static EvalStmtResult EvaluateSwitch(StmtResult &Result, EvalInfo &Info,
-                                     const SwitchStmt *SS) {
-  BlockScopeRAII Scope(Info);
-
-  // Evaluate the switch condition.
-  APSInt Value;
-  {
-    FullExpressionRAII Scope(Info);
-    if (const Stmt *Init = SS->getInit()) {
-      EvalStmtResult ESR = EvaluateStmt(Result, Info, Init);
-      if (ESR != ESR_Succeeded)
-        return ESR;
-    }
-    if (SS->getConditionVariable() &&
-        !EvaluateDecl(Info, SS->getConditionVariable()))
-      return ESR_Failed;
-    if (!EvaluateInteger(SS->getCond(), Value, Info))
-      return ESR_Failed;
-  }
-
-  // Find the switch case corresponding to the value of the condition.
-  // FIXME: Cache this lookup.
-  const SwitchCase *Found = nullptr;
-  for (const SwitchCase *SC = SS->getSwitchCaseList(); SC;
-       SC = SC->getNextSwitchCase()) {
-    if (isa<DefaultStmt>(SC)) {
-      Found = SC;
-      continue;
-    }
-
-    const CaseStmt *CS = cast<CaseStmt>(SC);
-    APSInt LHS = CS->getLHS()->EvaluateKnownConstInt(Info.Ctx);
-    APSInt RHS = CS->getRHS() ? CS->getRHS()->EvaluateKnownConstInt(Info.Ctx)
-                              : LHS;
-    if (LHS <= Value && Value <= RHS) {
-      Found = SC;
-      break;
-    }
-  }
-
-  if (!Found)
-    return ESR_Succeeded;
-
-  // Search the switch body for the switch case and evaluate it from there.
-  switch (EvalStmtResult ESR = EvaluateStmt(Result, Info, SS->getBody(), Found)) {
-  case ESR_Break:
-    return ESR_Succeeded;
-  case ESR_Succeeded:
-  case ESR_Continue:
-  case ESR_Failed:
-  case ESR_Returned:
-    return ESR;
-  case ESR_CaseNotFound:
-    // This can only happen if the switch case is nested within a statement
-    // expression. We have no intention of supporting that.
-    Info.FFDiag(Found->getBeginLoc(),
-                diag::note_constexpr_stmt_expr_unsupported);
-    return ESR_Failed;
-  }
-  llvm_unreachable("Invalid EvalStmtResult!");
-}
-
-// Evaluate a statement.
-static EvalStmtResult EvaluateStmt(StmtResult &Result, EvalInfo &Info,
-                                   const Stmt *S, const SwitchCase *Case) {
-  if (!Info.nextStep(S))
-    return ESR_Failed;
-
-  // If we're hunting down a 'case' or 'default' label, recurse through
-  // substatements until we hit the label.
-  if (Case) {
-    // FIXME: We don't start the lifetime of objects whose initialization we
-    // jump over. However, such objects must be of class type with a trivial
-    // default constructor that initialize all subobjects, so must be empty,
-    // so this almost never matters.
-    switch (S->getStmtClass()) {
-    case Stmt::CompoundStmtClass:
-      // FIXME: Precompute which substatement of a compound statement we
-      // would jump to, and go straight there rather than performing a
-      // linear scan each time.
-    case Stmt::LabelStmtClass:
-    case Stmt::AttributedStmtClass:
-    case Stmt::DoStmtClass:
-      break;
-
-    case Stmt::CaseStmtClass:
-    case Stmt::DefaultStmtClass:
-      if (Case == S)
-        Case = nullptr;
-      break;
-
-    case Stmt::IfStmtClass: {
-      // FIXME: Precompute which side of an 'if' we would jump to, and go
-      // straight there rather than scanning both sides.
-      const IfStmt *IS = cast<IfStmt>(S);
-
-      // Wrap the evaluation in a block scope, in case it's a DeclStmt
-      // preceded by our switch label.
-      BlockScopeRAII Scope(Info);
-
-      EvalStmtResult ESR = EvaluateStmt(Result, Info, IS->getThen(), Case);
-      if (ESR != ESR_CaseNotFound || !IS->getElse())
-        return ESR;
-      return EvaluateStmt(Result, Info, IS->getElse(), Case);
-    }
-
-    case Stmt::WhileStmtClass: {
-      EvalStmtResult ESR =
-          EvaluateLoopBody(Result, Info, cast<WhileStmt>(S)->getBody(), Case);
-      if (ESR != ESR_Continue)
-        return ESR;
-      break;
-    }
-
-    case Stmt::ForStmtClass: {
-      const ForStmt *FS = cast<ForStmt>(S);
-      EvalStmtResult ESR =
-          EvaluateLoopBody(Result, Info, FS->getBody(), Case);
-      if (ESR != ESR_Continue)
-        return ESR;
-      if (FS->getInc()) {
-        FullExpressionRAII IncScope(Info);
-        if (!EvaluateIgnoredValue(Info, FS->getInc()))
-          return ESR_Failed;
-      }
-      break;
-    }
-
-    case Stmt::DeclStmtClass:
-      // FIXME: If the variable has initialization that can't be jumped over,
-      // bail out of any immediately-surrounding compound-statement too.
-    default:
-      return ESR_CaseNotFound;
-    }
-  }
-
-  switch (S->getStmtClass()) {
-  default:
-    if (const Expr *E = dyn_cast<Expr>(S)) {
-      // Don't bother evaluating beyond an expression-statement which couldn't
-      // be evaluated.
-      FullExpressionRAII Scope(Info);
-      if (!EvaluateIgnoredValue(Info, E))
-        return ESR_Failed;
-      return ESR_Succeeded;
-    }
-
-    Info.FFDiag(S->getBeginLoc());
-    return ESR_Failed;
-
-  case Stmt::NullStmtClass:
-    return ESR_Succeeded;
-
-  case Stmt::DeclStmtClass: {
-    const DeclStmt *DS = cast<DeclStmt>(S);
-    for (const auto *DclIt : DS->decls()) {
-      // Each declaration initialization is its own full-expression.
-      // FIXME: This isn't quite right; if we're performing aggregate
-      // initialization, each braced subexpression is its own full-expression.
-      FullExpressionRAII Scope(Info);
-      if (!EvaluateDecl(Info, DclIt) && !Info.noteFailure())
-        return ESR_Failed;
-    }
-    return ESR_Succeeded;
-  }
-
-  case Stmt::ReturnStmtClass: {
-    const Expr *RetExpr = cast<ReturnStmt>(S)->getRetValue();
-    FullExpressionRAII Scope(Info);
-    if (RetExpr &&
-        !(Result.Slot
-              ? EvaluateInPlace(Result.Value, Info, *Result.Slot, RetExpr)
-              : Evaluate(Result.Value, Info, RetExpr)))
-      return ESR_Failed;
-    return ESR_Returned;
-  }
-
-  case Stmt::CompoundStmtClass: {
-    BlockScopeRAII Scope(Info);
-
-    const CompoundStmt *CS = cast<CompoundStmt>(S);
-    for (const auto *BI : CS->body()) {
-      EvalStmtResult ESR = EvaluateStmt(Result, Info, BI, Case);
-      if (ESR == ESR_Succeeded)
-        Case = nullptr;
-      else if (ESR != ESR_CaseNotFound)
-        return ESR;
-    }
-    return Case ? ESR_CaseNotFound : ESR_Succeeded;
-  }
-
-  case Stmt::IfStmtClass: {
-    const IfStmt *IS = cast<IfStmt>(S);
-
-    // Evaluate the condition, as either a var decl or as an expression.
-    BlockScopeRAII Scope(Info);
-    if (const Stmt *Init = IS->getInit()) {
-      EvalStmtResult ESR = EvaluateStmt(Result, Info, Init);
-      if (ESR != ESR_Succeeded)
-        return ESR;
-    }
-    bool Cond;
-    if (!EvaluateCond(Info, IS->getConditionVariable(), IS->getCond(), Cond))
-      return ESR_Failed;
-
-    if (const Stmt *SubStmt = Cond ? IS->getThen() : IS->getElse()) {
-      EvalStmtResult ESR = EvaluateStmt(Result, Info, SubStmt);
-      if (ESR != ESR_Succeeded)
-        return ESR;
-    }
-    return ESR_Succeeded;
-  }
-
-  case Stmt::WhileStmtClass: {
-    const WhileStmt *WS = cast<WhileStmt>(S);
-    while (true) {
-      BlockScopeRAII Scope(Info);
-      bool Continue;
-      if (!EvaluateCond(Info, WS->getConditionVariable(), WS->getCond(),
-                        Continue))
-        return ESR_Failed;
-      if (!Continue)
-        break;
-
-      EvalStmtResult ESR = EvaluateLoopBody(Result, Info, WS->getBody());
-      if (ESR != ESR_Continue)
-        return ESR;
-    }
-    return ESR_Succeeded;
-  }
-
-  case Stmt::DoStmtClass: {
-    const DoStmt *DS = cast<DoStmt>(S);
-    bool Continue;
-    do {
-      EvalStmtResult ESR = EvaluateLoopBody(Result, Info, DS->getBody(), Case);
-      if (ESR != ESR_Continue)
-        return ESR;
-      Case = nullptr;
-
-      FullExpressionRAII CondScope(Info);
-      if (!EvaluateAsBooleanCondition(DS->getCond(), Continue, Info))
-        return ESR_Failed;
-    } while (Continue);
-    return ESR_Succeeded;
-  }
-
-  case Stmt::ForStmtClass: {
-    const ForStmt *FS = cast<ForStmt>(S);
-    BlockScopeRAII Scope(Info);
-    if (FS->getInit()) {
-      EvalStmtResult ESR = EvaluateStmt(Result, Info, FS->getInit());
-      if (ESR != ESR_Succeeded)
-        return ESR;
-    }
-    while (true) {
-      BlockScopeRAII Scope(Info);
-      bool Continue = true;
-      if (FS->getCond() && !EvaluateCond(Info, FS->getConditionVariable(),
-                                         FS->getCond(), Continue))
-        return ESR_Failed;
-      if (!Continue)
-        break;
-
-      EvalStmtResult ESR = EvaluateLoopBody(Result, Info, FS->getBody());
-      if (ESR != ESR_Continue)
-        return ESR;
-
-      if (FS->getInc()) {
-        FullExpressionRAII IncScope(Info);
-        if (!EvaluateIgnoredValue(Info, FS->getInc()))
-          return ESR_Failed;
-      }
-    }
-    return ESR_Succeeded;
-  }
-
-  case Stmt::CXXForRangeStmtClass: {
-    const CXXForRangeStmt *FS = cast<CXXForRangeStmt>(S);
-    BlockScopeRAII Scope(Info);
-
-    // Evaluate the init-statement if present.
-    if (FS->getInit()) {
-      EvalStmtResult ESR = EvaluateStmt(Result, Info, FS->getInit());
-      if (ESR != ESR_Succeeded)
-        return ESR;
-    }
-
-    // Initialize the __range variable.
-    EvalStmtResult ESR = EvaluateStmt(Result, Info, FS->getRangeStmt());
-    if (ESR != ESR_Succeeded)
-      return ESR;
-
-    // Create the __begin and __end iterators.
-    ESR = EvaluateStmt(Result, Info, FS->getBeginStmt());
-    if (ESR != ESR_Succeeded)
-      return ESR;
-    ESR = EvaluateStmt(Result, Info, FS->getEndStmt());
-    if (ESR != ESR_Succeeded)
-      return ESR;
-
-    while (true) {
-      // Condition: __begin != __end.
-      {
-        bool Continue = true;
-        FullExpressionRAII CondExpr(Info);
-        if (!EvaluateAsBooleanCondition(FS->getCond(), Continue, Info))
-          return ESR_Failed;
-        if (!Continue)
-          break;
-      }
-
-      // User's variable declaration, initialized by *__begin.
-      BlockScopeRAII InnerScope(Info);
-      ESR = EvaluateStmt(Result, Info, FS->getLoopVarStmt());
-      if (ESR != ESR_Succeeded)
-        return ESR;
-
-      // Loop body.
-      ESR = EvaluateLoopBody(Result, Info, FS->getBody());
-      if (ESR != ESR_Continue)
-        return ESR;
-
-      // Increment: ++__begin
-      if (!EvaluateIgnoredValue(Info, FS->getInc()))
-        return ESR_Failed;
-    }
-
-    return ESR_Succeeded;
-  }
-
-  case Stmt::SwitchStmtClass:
-    return EvaluateSwitch(Result, Info, cast<SwitchStmt>(S));
-
-  case Stmt::ContinueStmtClass:
-    return ESR_Continue;
-
-  case Stmt::BreakStmtClass:
-    return ESR_Break;
-
-  case Stmt::LabelStmtClass:
-    return EvaluateStmt(Result, Info, cast<LabelStmt>(S)->getSubStmt(), Case);
-
-  case Stmt::AttributedStmtClass:
-    // As a general principle, C++11 attributes can be ignored without
-    // any semantic impact.
-    return EvaluateStmt(Result, Info, cast<AttributedStmt>(S)->getSubStmt(),
-                        Case);
-
-  case Stmt::CaseStmtClass:
-  case Stmt::DefaultStmtClass:
-    return EvaluateStmt(Result, Info, cast<SwitchCase>(S)->getSubStmt(), Case);
-  case Stmt::CXXTryStmtClass:
-    // Evaluate try blocks by evaluating all sub statements.
-    return EvaluateStmt(Result, Info, cast<CXXTryStmt>(S)->getTryBlock(), Case);
-  }
-}
-
-/// CheckTrivialDefaultConstructor - Check whether a constructor is a trivial
-/// default constructor. If so, we'll fold it whether or not it's marked as
-/// constexpr. If it is marked as constexpr, we will never implicitly define it,
-/// so we need special handling.
-static bool CheckTrivialDefaultConstructor(EvalInfo &Info, SourceLocation Loc,
-                                           const CXXConstructorDecl *CD,
-                                           bool IsValueInitialization) {
-  if (!CD->isTrivial() || !CD->isDefaultConstructor())
-    return false;
-
-  // Value-initialization does not call a trivial default constructor, so such a
-  // call is a core constant expression whether or not the constructor is
-  // constexpr.
-  if (!CD->isConstexpr() && !IsValueInitialization) {
-    if (Info.getLangOpts().CPlusPlus11) {
-      // FIXME: If DiagDecl is an implicitly-declared special member function,
-      // we should be much more explicit about why it's not constexpr.
-      Info.CCEDiag(Loc, diag::note_constexpr_invalid_function, 1)
-        << /*IsConstexpr*/0 << /*IsConstructor*/1 << CD;
-      Info.Note(CD->getLocation(), diag::note_declared_at);
-    } else {
-      Info.CCEDiag(Loc, diag::note_invalid_subexpr_in_const_expr);
-    }
-  }
-  return true;
-}
-
-/// CheckConstexprFunction - Check that a function can be called in a constant
-/// expression.
-static bool CheckConstexprFunction(EvalInfo &Info, SourceLocation CallLoc,
-                                   const FunctionDecl *Declaration,
-                                   const FunctionDecl *Definition,
-                                   const Stmt *Body) {
-  // Potential constant expressions can contain calls to declared, but not yet
-  // defined, constexpr functions.
-  if (Info.checkingPotentialConstantExpression() && !Definition &&
-      Declaration->isConstexpr())
-    return false;
-
-  // Bail out if the function declaration itself is invalid.  We will
-  // have produced a relevant diagnostic while parsing it, so just
-  // note the problematic sub-expression.
-  if (Declaration->isInvalidDecl()) {
-    Info.FFDiag(CallLoc, diag::note_invalid_subexpr_in_const_expr);
-    return false;
-  }
-
-  // Can we evaluate this function call?
-  if (Definition && Definition->isConstexpr() &&
-      !Definition->isInvalidDecl() && Body)
-    return true;
-
-  if (Info.getLangOpts().CPlusPlus11) {
-    const FunctionDecl *DiagDecl = Definition ? Definition : Declaration;
-
-    // If this function is not constexpr because it is an inherited
-    // non-constexpr constructor, diagnose that directly.
-    auto *CD = dyn_cast<CXXConstructorDecl>(DiagDecl);
-    if (CD && CD->isInheritingConstructor()) {
-      auto *Inherited = CD->getInheritedConstructor().getConstructor();
-      if (!Inherited->isConstexpr())
-        DiagDecl = CD = Inherited;
-    }
-
-    // FIXME: If DiagDecl is an implicitly-declared special member function
-    // or an inheriting constructor, we should be much more explicit about why
-    // it's not constexpr.
-    if (CD && CD->isInheritingConstructor())
-      Info.FFDiag(CallLoc, diag::note_constexpr_invalid_inhctor, 1)
-        << CD->getInheritedConstructor().getConstructor()->getParent();
-    else
-      Info.FFDiag(CallLoc, diag::note_constexpr_invalid_function, 1)
-        << DiagDecl->isConstexpr() << (bool)CD << DiagDecl;
-    Info.Note(DiagDecl->getLocation(), diag::note_declared_at);
-  } else {
-    Info.FFDiag(CallLoc, diag::note_invalid_subexpr_in_const_expr);
-  }
-  return false;
-}
-
-/// Determine if a class has any fields that might need to be copied by a
-/// trivial copy or move operation.
-static bool hasFields(const CXXRecordDecl *RD) {
-  if (!RD || RD->isEmpty())
-    return false;
-  for (auto *FD : RD->fields()) {
-    if (FD->isUnnamedBitfield())
-      continue;
-    return true;
-  }
-  for (auto &Base : RD->bases())
-    if (hasFields(Base.getType()->getAsCXXRecordDecl()))
-      return true;
-  return false;
-}
-
-namespace {
-typedef SmallVector<APValue, 8> ArgVector;
-}
-
-/// EvaluateArgs - Evaluate the arguments to a function call.
-static bool EvaluateArgs(ArrayRef<const Expr*> Args, ArgVector &ArgValues,
-                         EvalInfo &Info) {
-  bool Success = true;
-  for (ArrayRef<const Expr*>::iterator I = Args.begin(), E = Args.end();
-       I != E; ++I) {
-    if (!Evaluate(ArgValues[I - Args.begin()], Info, *I)) {
-      // If we're checking for a potential constant expression, evaluate all
-      // initializers even if some of them fail.
-      if (!Info.noteFailure())
-        return false;
-      Success = false;
-    }
-  }
-  return Success;
-}
-
-/// Evaluate a function call.
-static bool HandleFunctionCall(SourceLocation CallLoc,
-                               const FunctionDecl *Callee, const LValue *This,
-                               ArrayRef<const Expr*> Args, const Stmt *Body,
-                               EvalInfo &Info, APValue &Result,
-                               const LValue *ResultSlot) {
-  ArgVector ArgValues(Args.size());
-  if (!EvaluateArgs(Args, ArgValues, Info))
-    return false;
-
-  if (!Info.CheckCallLimit(CallLoc))
-    return false;
-
-  CallStackFrame Frame(Info, CallLoc, Callee, This, ArgValues.data());
-
-  // For a trivial copy or move assignment, perform an APValue copy. This is
-  // essential for unions, where the operations performed by the assignment
-  // operator cannot be represented as statements.
-  //
-  // Skip this for non-union classes with no fields; in that case, the defaulted
-  // copy/move does not actually read the object.
-  const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(Callee);
-  if (MD && MD->isDefaulted() &&
-      (MD->getParent()->isUnion() ||
-       (MD->isTrivial() && hasFields(MD->getParent())))) {
-    assert(This &&
-           (MD->isCopyAssignmentOperator() || MD->isMoveAssignmentOperator()));
-    LValue RHS;
-    RHS.setFrom(Info.Ctx, ArgValues[0]);
-    APValue RHSValue;
-    if (!handleLValueToRValueConversion(Info, Args[0], Args[0]->getType(),
-                                        RHS, RHSValue))
-      return false;
-    if (!handleAssignment(Info, Args[0], *This, MD->getThisType(),
-                          RHSValue))
-      return false;
-    This->moveInto(Result);
-    return true;
-  } else if (MD && isLambdaCallOperator(MD)) {
-    // We're in a lambda; determine the lambda capture field maps unless we're
-    // just constexpr checking a lambda's call operator. constexpr checking is
-    // done before the captures have been added to the closure object (unless
-    // we're inferring constexpr-ness), so we don't have access to them in this
-    // case. But since we don't need the captures to constexpr check, we can
-    // just ignore them.
-    if (!Info.checkingPotentialConstantExpression())
-      MD->getParent()->getCaptureFields(Frame.LambdaCaptureFields,
-                                        Frame.LambdaThisCaptureField);
-  }
-
-  StmtResult Ret = {Result, ResultSlot};
-  EvalStmtResult ESR = EvaluateStmt(Ret, Info, Body);
-  if (ESR == ESR_Succeeded) {
-    if (Callee->getReturnType()->isVoidType())
-      return true;
-    Info.FFDiag(Callee->getEndLoc(), diag::note_constexpr_no_return);
-  }
-  return ESR == ESR_Returned;
-}
-
-/// Evaluate a constructor call.
-static bool HandleConstructorCall(const Expr *E, const LValue &This,
-                                  APValue *ArgValues,
-                                  const CXXConstructorDecl *Definition,
-                                  EvalInfo &Info, APValue &Result) {
-  SourceLocation CallLoc = E->getExprLoc();
-  if (!Info.CheckCallLimit(CallLoc))
-    return false;
-
-  const CXXRecordDecl *RD = Definition->getParent();
-  if (RD->getNumVBases()) {
-    Info.FFDiag(CallLoc, diag::note_constexpr_virtual_base) << RD;
-    return false;
-  }
-
-  EvalInfo::EvaluatingConstructorRAII EvalObj(
-      Info, {This.getLValueBase(),
-             {This.getLValueCallIndex(), This.getLValueVersion()}});
-  CallStackFrame Frame(Info, CallLoc, Definition, &This, ArgValues);
-
-  // FIXME: Creating an APValue just to hold a nonexistent return value is
-  // wasteful.
-  APValue RetVal;
-  StmtResult Ret = {RetVal, nullptr};
-
-  // If it's a delegating constructor, delegate.
-  if (Definition->isDelegatingConstructor()) {
-    CXXConstructorDecl::init_const_iterator I = Definition->init_begin();
-    {
-      FullExpressionRAII InitScope(Info);
-      if (!EvaluateInPlace(Result, Info, This, (*I)->getInit()))
-        return false;
-    }
-    return EvaluateStmt(Ret, Info, Definition->getBody()) != ESR_Failed;
-  }
-
-  // For a trivial copy or move constructor, perform an APValue copy. This is
-  // essential for unions (or classes with anonymous union members), where the
-  // operations performed by the constructor cannot be represented by
-  // ctor-initializers.
-  //
-  // Skip this for empty non-union classes; we should not perform an
-  // lvalue-to-rvalue conversion on them because their copy constructor does not
-  // actually read them.
-  if (Definition->isDefaulted() && Definition->isCopyOrMoveConstructor() &&
-      (Definition->getParent()->isUnion() ||
-       (Definition->isTrivial() && hasFields(Definition->getParent())))) {
-    LValue RHS;
-    RHS.setFrom(Info.Ctx, ArgValues[0]);
-    return handleLValueToRValueConversion(
-        Info, E, Definition->getParamDecl(0)->getType().getNonReferenceType(),
-        RHS, Result);
-  }
-
-  // Reserve space for the struct members.
-  if (!RD->isUnion() && Result.isUninit())
-    Result = APValue(APValue::UninitStruct(), RD->getNumBases(),
-                     std::distance(RD->field_begin(), RD->field_end()));
-
-  if (RD->isInvalidDecl()) return false;
-  const ASTRecordLayout &Layout = Info.Ctx.getASTRecordLayout(RD);
-
-  // A scope for temporaries lifetime-extended by reference members.
-  BlockScopeRAII LifetimeExtendedScope(Info);
-
-  bool Success = true;
-  unsigned BasesSeen = 0;
-#ifndef NDEBUG
-  CXXRecordDecl::base_class_const_iterator BaseIt = RD->bases_begin();
-#endif
-  for (const auto *I : Definition->inits()) {
-    LValue Subobject = This;
-    LValue SubobjectParent = This;
-    APValue *Value = &Result;
-
-    // Determine the subobject to initialize.
-    FieldDecl *FD = nullptr;
-    if (I->isBaseInitializer()) {
-      QualType BaseType(I->getBaseClass(), 0);
-#ifndef NDEBUG
-      // Non-virtual base classes are initialized in the order in the class
-      // definition. We have already checked for virtual base classes.
-      assert(!BaseIt->isVirtual() && "virtual base for literal type");
-      assert(Info.Ctx.hasSameType(BaseIt->getType(), BaseType) &&
-             "base class initializers not in expected order");
-      ++BaseIt;
-#endif
-      if (!HandleLValueDirectBase(Info, I->getInit(), Subobject, RD,
-                                  BaseType->getAsCXXRecordDecl(), &Layout))
-        return false;
-      Value = &Result.getStructBase(BasesSeen++);
-    } else if ((FD = I->getMember())) {
-      if (!HandleLValueMember(Info, I->getInit(), Subobject, FD, &Layout))
-        return false;
-      if (RD->isUnion()) {
-        Result = APValue(FD);
-        Value = &Result.getUnionValue();
-      } else {
-        Value = &Result.getStructField(FD->getFieldIndex());
-      }
-    } else if (IndirectFieldDecl *IFD = I->getIndirectMember()) {
-      // Walk the indirect field decl's chain to find the object to initialize,
-      // and make sure we've initialized every step along it.
-      auto IndirectFieldChain = IFD->chain();
-      for (auto *C : IndirectFieldChain) {
-        FD = cast<FieldDecl>(C);
-        CXXRecordDecl *CD = cast<CXXRecordDecl>(FD->getParent());
-        // Switch the union field if it differs. This happens if we had
-        // preceding zero-initialization, and we're now initializing a union
-        // subobject other than the first.
-        // FIXME: In this case, the values of the other subobjects are
-        // specified, since zero-initialization sets all padding bits to zero.
-        if (Value->isUninit() ||
-            (Value->isUnion() && Value->getUnionField() != FD)) {
-          if (CD->isUnion())
-            *Value = APValue(FD);
-          else
-            *Value = APValue(APValue::UninitStruct(), CD->getNumBases(),
-                             std::distance(CD->field_begin(), CD->field_end()));
-        }
-        // Store Subobject as its parent before updating it for the last element
-        // in the chain.
-        if (C == IndirectFieldChain.back())
-          SubobjectParent = Subobject;
-        if (!HandleLValueMember(Info, I->getInit(), Subobject, FD))
-          return false;
-        if (CD->isUnion())
-          Value = &Value->getUnionValue();
-        else
-          Value = &Value->getStructField(FD->getFieldIndex());
-      }
-    } else {
-      llvm_unreachable("unknown base initializer kind");
-    }
-
-    // Need to override This for implicit field initializers as in this case
-    // This refers to innermost anonymous struct/union containing initializer,
-    // not to currently constructed class.
-    const Expr *Init = I->getInit();
-    ThisOverrideRAII ThisOverride(*Info.CurrentCall, &SubobjectParent,
-                                  isa<CXXDefaultInitExpr>(Init));
-    FullExpressionRAII InitScope(Info);
-    if (!EvaluateInPlace(*Value, Info, Subobject, Init) ||
-        (FD && FD->isBitField() &&
-         !truncateBitfieldValue(Info, Init, *Value, FD))) {
-      // If we're checking for a potential constant expression, evaluate all
-      // initializers even if some of them fail.
-      if (!Info.noteFailure())
-        return false;
-      Success = false;
-    }
-  }
-
-  return Success &&
-         EvaluateStmt(Ret, Info, Definition->getBody()) != ESR_Failed;
-}
-
-static bool HandleConstructorCall(const Expr *E, const LValue &This,
-                                  ArrayRef<const Expr*> Args,
-                                  const CXXConstructorDecl *Definition,
-                                  EvalInfo &Info, APValue &Result) {
-  ArgVector ArgValues(Args.size());
-  if (!EvaluateArgs(Args, ArgValues, Info))
-    return false;
-
-  return HandleConstructorCall(E, This, ArgValues.data(), Definition,
-                               Info, Result);
-}
-
-//===----------------------------------------------------------------------===//
-// Generic Evaluation
-//===----------------------------------------------------------------------===//
-namespace {
-
-template <class Derived>
-class ExprEvaluatorBase
-  : public ConstStmtVisitor<Derived, bool> {
-private:
-  Derived &getDerived() { return static_cast<Derived&>(*this); }
-  bool DerivedSuccess(const APValue &V, const Expr *E) {
-    return getDerived().Success(V, E);
-  }
-  bool DerivedZeroInitialization(const Expr *E) {
-    return getDerived().ZeroInitialization(E);
-  }
-
-  // Check whether a conditional operator with a non-constant condition is a
-  // potential constant expression. If neither arm is a potential constant
-  // expression, then the conditional operator is not either.
-  template<typename ConditionalOperator>
-  void CheckPotentialConstantConditional(const ConditionalOperator *E) {
-    assert(Info.checkingPotentialConstantExpression());
-
-    // Speculatively evaluate both arms.
-    SmallVector<PartialDiagnosticAt, 8> Diag;
-    {
-      SpeculativeEvaluationRAII Speculate(Info, &Diag);
-      StmtVisitorTy::Visit(E->getFalseExpr());
-      if (Diag.empty())
-        return;
-    }
-
-    {
-      SpeculativeEvaluationRAII Speculate(Info, &Diag);
-      Diag.clear();
-      StmtVisitorTy::Visit(E->getTrueExpr());
-      if (Diag.empty())
-        return;
-    }
-
-    Error(E, diag::note_constexpr_conditional_never_const);
-  }
-
-
-  template<typename ConditionalOperator>
-  bool HandleConditionalOperator(const ConditionalOperator *E) {
-    bool BoolResult;
-    if (!EvaluateAsBooleanCondition(E->getCond(), BoolResult, Info)) {
-      if (Info.checkingPotentialConstantExpression() && Info.noteFailure()) {
-        CheckPotentialConstantConditional(E);
-        return false;
-      }
-      if (Info.noteFailure()) {
-        StmtVisitorTy::Visit(E->getTrueExpr());
-        StmtVisitorTy::Visit(E->getFalseExpr());
-      }
-      return false;
-    }
-
-    Expr *EvalExpr = BoolResult ? E->getTrueExpr() : E->getFalseExpr();
-    return StmtVisitorTy::Visit(EvalExpr);
-  }
-
-protected:
-  EvalInfo &Info;
-  typedef ConstStmtVisitor<Derived, bool> StmtVisitorTy;
-  typedef ExprEvaluatorBase ExprEvaluatorBaseTy;
-
-  OptionalDiagnostic CCEDiag(const Expr *E, diag::kind D) {
-    return Info.CCEDiag(E, D);
-  }
-
-  bool ZeroInitialization(const Expr *E) { return Error(E); }
-
-public:
-  ExprEvaluatorBase(EvalInfo &Info) : Info(Info) {}
-
-  EvalInfo &getEvalInfo() { return Info; }
-
-  /// Report an evaluation error. This should only be called when an error is
-  /// first discovered. When propagating an error, just return false.
-  bool Error(const Expr *E, diag::kind D) {
-    Info.FFDiag(E, D);
-    return false;
-  }
-  bool Error(const Expr *E) {
-    return Error(E, diag::note_invalid_subexpr_in_const_expr);
-  }
-
-  bool VisitStmt(const Stmt *) {
-    llvm_unreachable("Expression evaluator should not be called on stmts");
-  }
-  bool VisitExpr(const Expr *E) {
-    return Error(E);
-  }
-
-  bool VisitConstantExpr(const ConstantExpr *E)
-    { return StmtVisitorTy::Visit(E->getSubExpr()); }
-  bool VisitParenExpr(const ParenExpr *E)
-    { return StmtVisitorTy::Visit(E->getSubExpr()); }
-  bool VisitUnaryExtension(const UnaryOperator *E)
-    { return StmtVisitorTy::Visit(E->getSubExpr()); }
-  bool VisitUnaryPlus(const UnaryOperator *E)
-    { return StmtVisitorTy::Visit(E->getSubExpr()); }
-  bool VisitChooseExpr(const ChooseExpr *E)
-    { return StmtVisitorTy::Visit(E->getChosenSubExpr()); }
-  bool VisitGenericSelectionExpr(const GenericSelectionExpr *E)
-    { return StmtVisitorTy::Visit(E->getResultExpr()); }
-  bool VisitSubstNonTypeTemplateParmExpr(const SubstNonTypeTemplateParmExpr *E)
-    { return StmtVisitorTy::Visit(E->getReplacement()); }
-  bool VisitCXXDefaultArgExpr(const CXXDefaultArgExpr *E) {
-    TempVersionRAII RAII(*Info.CurrentCall);
-    return StmtVisitorTy::Visit(E->getExpr());
-  }
-  bool VisitCXXDefaultInitExpr(const CXXDefaultInitExpr *E) {
-    TempVersionRAII RAII(*Info.CurrentCall);
-    // The initializer may not have been parsed yet, or might be erroneous.
-    if (!E->getExpr())
-      return Error(E);
-    return StmtVisitorTy::Visit(E->getExpr());
-  }
-  // We cannot create any objects for which cleanups are required, so there is
-  // nothing to do here; all cleanups must come from unevaluated subexpressions.
-  bool VisitExprWithCleanups(const ExprWithCleanups *E)
-    { return StmtVisitorTy::Visit(E->getSubExpr()); }
-
-  bool VisitCXXReinterpretCastExpr(const CXXReinterpretCastExpr *E) {
-    CCEDiag(E, diag::note_constexpr_invalid_cast) << 0;
-    return static_cast<Derived*>(this)->VisitCastExpr(E);
-  }
-  bool VisitCXXDynamicCastExpr(const CXXDynamicCastExpr *E) {
-    CCEDiag(E, diag::note_constexpr_invalid_cast) << 1;
-    return static_cast<Derived*>(this)->VisitCastExpr(E);
-  }
-
-  bool VisitBinaryOperator(const BinaryOperator *E) {
-    switch (E->getOpcode()) {
-    default:
-      return Error(E);
-
-    case BO_Comma:
-      VisitIgnoredValue(E->getLHS());
-      return StmtVisitorTy::Visit(E->getRHS());
-
-    case BO_PtrMemD:
-    case BO_PtrMemI: {
-      LValue Obj;
-      if (!HandleMemberPointerAccess(Info, E, Obj))
-        return false;
-      APValue Result;
-      if (!handleLValueToRValueConversion(Info, E, E->getType(), Obj, Result))
-        return false;
-      return DerivedSuccess(Result, E);
-    }
-    }
-  }
-
-  bool VisitBinaryConditionalOperator(const BinaryConditionalOperator *E) {
-    // Evaluate and cache the common expression. We treat it as a temporary,
-    // even though it's not quite the same thing.
-    if (!Evaluate(Info.CurrentCall->createTemporary(E->getOpaqueValue(), false),
-                  Info, E->getCommon()))
-      return false;
-
-    return HandleConditionalOperator(E);
-  }
-
-  bool VisitConditionalOperator(const ConditionalOperator *E) {
-    bool IsBcpCall = false;
-    // If the condition (ignoring parens) is a __builtin_constant_p call,
-    // the result is a constant expression if it can be folded without
-    // side-effects. This is an important GNU extension. See GCC PR38377
-    // for discussion.
-    if (const CallExpr *CallCE =
-          dyn_cast<CallExpr>(E->getCond()->IgnoreParenCasts()))
-      if (CallCE->getBuiltinCallee() == Builtin::BI__builtin_constant_p)
-        IsBcpCall = true;
-
-    // Always assume __builtin_constant_p(...) ? ... : ... is a potential
-    // constant expression; we can't check whether it's potentially foldable.
-    if (Info.checkingPotentialConstantExpression() && IsBcpCall)
-      return false;
-
-    FoldConstant Fold(Info, IsBcpCall);
-    if (!HandleConditionalOperator(E)) {
-      Fold.keepDiagnostics();
-      return false;
-    }
-
-    return true;
-  }
-
-  bool VisitOpaqueValueExpr(const OpaqueValueExpr *E) {
-    if (APValue *Value = Info.CurrentCall->getCurrentTemporary(E))
-      return DerivedSuccess(*Value, E);
-
-    const Expr *Source = E->getSourceExpr();
-    if (!Source)
-      return Error(E);
-    if (Source == E) { // sanity checking.
-      assert(0 && "OpaqueValueExpr recursively refers to itself");
-      return Error(E);
-    }
-    return StmtVisitorTy::Visit(Source);
-  }
-
-  bool VisitCallExpr(const CallExpr *E) {
-    APValue Result;
-    if (!handleCallExpr(E, Result, nullptr))
-      return false;
-    return DerivedSuccess(Result, E);
-  }
-
-  bool handleCallExpr(const CallExpr *E, APValue &Result,
-                     const LValue *ResultSlot) {
-    const Expr *Callee = E->getCallee()->IgnoreParens();
-    QualType CalleeType = Callee->getType();
-
-    const FunctionDecl *FD = nullptr;
-    LValue *This = nullptr, ThisVal;
-    auto Args = llvm::makeArrayRef(E->getArgs(), E->getNumArgs());
-    bool HasQualifier = false;
-
-    // Extract function decl and 'this' pointer from the callee.
-    if (CalleeType->isSpecificBuiltinType(BuiltinType::BoundMember)) {
-      const ValueDecl *Member = nullptr;
-      if (const MemberExpr *ME = dyn_cast<MemberExpr>(Callee)) {
-        // Explicit bound member calls, such as x.f() or p->g();
-        if (!EvaluateObjectArgument(Info, ME->getBase(), ThisVal))
-          return false;
-        Member = ME->getMemberDecl();
-        This = &ThisVal;
-        HasQualifier = ME->hasQualifier();
-      } else if (const BinaryOperator *BE = dyn_cast<BinaryOperator>(Callee)) {
-        // Indirect bound member calls ('.*' or '->*').
-        Member = HandleMemberPointerAccess(Info, BE, ThisVal, false);
-        if (!Member) return false;
-        This = &ThisVal;
-      } else
-        return Error(Callee);
-
-      FD = dyn_cast<FunctionDecl>(Member);
-      if (!FD)
-        return Error(Callee);
-    } else if (CalleeType->isFunctionPointerType()) {
-      LValue Call;
-      if (!EvaluatePointer(Callee, Call, Info))
-        return false;
-
-      if (!Call.getLValueOffset().isZero())
-        return Error(Callee);
-      FD = dyn_cast_or_null<FunctionDecl>(
-                             Call.getLValueBase().dyn_cast<const ValueDecl*>());
-      if (!FD)
-        return Error(Callee);
-      // Don't call function pointers which have been cast to some other type.
-      // Per DR (no number yet), the caller and callee can differ in noexcept.
-      if (!Info.Ctx.hasSameFunctionTypeIgnoringExceptionSpec(
-        CalleeType->getPointeeType(), FD->getType())) {
-        return Error(E);
-      }
-
-      // Overloaded operator calls to member functions are represented as normal
-      // calls with '*this' as the first argument.
-      const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD);
-      if (MD && !MD->isStatic()) {
-        // FIXME: When selecting an implicit conversion for an overloaded
-        // operator delete, we sometimes try to evaluate calls to conversion
-        // operators without a 'this' parameter!
-        if (Args.empty())
-          return Error(E);
-
-        if (!EvaluateObjectArgument(Info, Args[0], ThisVal))
-          return false;
-        This = &ThisVal;
-        Args = Args.slice(1);
-      } else if (MD && MD->isLambdaStaticInvoker()) {
-        // Map the static invoker for the lambda back to the call operator.
-        // Conveniently, we don't have to slice out the 'this' argument (as is
-        // being done for the non-static case), since a static member function
-        // doesn't have an implicit argument passed in.
-        const CXXRecordDecl *ClosureClass = MD->getParent();
-        assert(
-            ClosureClass->captures_begin() == ClosureClass->captures_end() &&
-            "Number of captures must be zero for conversion to function-ptr");
-
-        const CXXMethodDecl *LambdaCallOp =
-            ClosureClass->getLambdaCallOperator();
-
-        // Set 'FD', the function that will be called below, to the call
-        // operator.  If the closure object represents a generic lambda, find
-        // the corresponding specialization of the call operator.
-
-        if (ClosureClass->isGenericLambda()) {
-          assert(MD->isFunctionTemplateSpecialization() &&
-                 "A generic lambda's static-invoker function must be a "
-                 "template specialization");
-          const TemplateArgumentList *TAL = MD->getTemplateSpecializationArgs();
-          FunctionTemplateDecl *CallOpTemplate =
-              LambdaCallOp->getDescribedFunctionTemplate();
-          void *InsertPos = nullptr;
-          FunctionDecl *CorrespondingCallOpSpecialization =
-              CallOpTemplate->findSpecialization(TAL->asArray(), InsertPos);
-          assert(CorrespondingCallOpSpecialization &&
-                 "We must always have a function call operator specialization "
-                 "that corresponds to our static invoker specialization");
-          FD = cast<CXXMethodDecl>(CorrespondingCallOpSpecialization);
-        } else
-          FD = LambdaCallOp;
-      }
-
-
-    } else
-      return Error(E);
-
-    if (This && !This->checkSubobject(Info, E, CSK_This))
-      return false;
-
-    // DR1358 allows virtual constexpr functions in some cases. Don't allow
-    // calls to such functions in constant expressions.
-    if (This && !HasQualifier &&
-        isa<CXXMethodDecl>(FD) && cast<CXXMethodDecl>(FD)->isVirtual())
-      return Error(E, diag::note_constexpr_virtual_call);
-
-    const FunctionDecl *Definition = nullptr;
-    Stmt *Body = FD->getBody(Definition);
-
-    if (!CheckConstexprFunction(Info, E->getExprLoc(), FD, Definition, Body) ||
-        !HandleFunctionCall(E->getExprLoc(), Definition, This, Args, Body, Info,
-                            Result, ResultSlot))
-      return false;
-
-    return true;
-  }
-
-  bool VisitCompoundLiteralExpr(const CompoundLiteralExpr *E) {
-    return StmtVisitorTy::Visit(E->getInitializer());
-  }
-  bool VisitInitListExpr(const InitListExpr *E) {
-    if (E->getNumInits() == 0)
-      return DerivedZeroInitialization(E);
-    if (E->getNumInits() == 1)
-      return StmtVisitorTy::Visit(E->getInit(0));
-    return Error(E);
-  }
-  bool VisitImplicitValueInitExpr(const ImplicitValueInitExpr *E) {
-    return DerivedZeroInitialization(E);
-  }
-  bool VisitCXXScalarValueInitExpr(const CXXScalarValueInitExpr *E) {
-    return DerivedZeroInitialization(E);
-  }
-  bool VisitCXXNullPtrLiteralExpr(const CXXNullPtrLiteralExpr *E) {
-    return DerivedZeroInitialization(E);
-  }
-
-  /// A member expression where the object is a prvalue is itself a prvalue.
-  bool VisitMemberExpr(const MemberExpr *E) {
-    assert(!E->isArrow() && "missing call to bound member function?");
-
-    APValue Val;
-    if (!Evaluate(Val, Info, E->getBase()))
-      return false;
-
-    QualType BaseTy = E->getBase()->getType();
-
-    const FieldDecl *FD = dyn_cast<FieldDecl>(E->getMemberDecl());
-    if (!FD) return Error(E);
-    assert(!FD->getType()->isReferenceType() && "prvalue reference?");
-    assert(BaseTy->castAs<RecordType>()->getDecl()->getCanonicalDecl() ==
-           FD->getParent()->getCanonicalDecl() && "record / field mismatch");
-
-    CompleteObject Obj(&Val, BaseTy, true);
-    SubobjectDesignator Designator(BaseTy);
-    Designator.addDeclUnchecked(FD);
-
-    APValue Result;
-    return extractSubobject(Info, E, Obj, Designator, Result) &&
-           DerivedSuccess(Result, E);
-  }
-
-  bool VisitCastExpr(const CastExpr *E) {
-    switch (E->getCastKind()) {
-    default:
-      break;
-
-    case CK_AtomicToNonAtomic: {
-      APValue AtomicVal;
-      // This does not need to be done in place even for class/array types:
-      // atomic-to-non-atomic conversion implies copying the object
-      // representation.
-      if (!Evaluate(AtomicVal, Info, E->getSubExpr()))
-        return false;
-      return DerivedSuccess(AtomicVal, E);
-    }
-
-    case CK_NoOp:
-    case CK_UserDefinedConversion:
-      return StmtVisitorTy::Visit(E->getSubExpr());
-
-    case CK_LValueToRValue: {
-      LValue LVal;
-      if (!EvaluateLValue(E->getSubExpr(), LVal, Info))
-        return false;
-      APValue RVal;
-      // Note, we use the subexpression's type in order to retain cv-qualifiers.
-      if (!handleLValueToRValueConversion(Info, E, E->getSubExpr()->getType(),
-                                          LVal, RVal))
-        return false;
-      return DerivedSuccess(RVal, E);
-    }
-    }
-
-    return Error(E);
-  }
-
-  bool VisitUnaryPostInc(const UnaryOperator *UO) {
-    return VisitUnaryPostIncDec(UO);
-  }
-  bool VisitUnaryPostDec(const UnaryOperator *UO) {
-    return VisitUnaryPostIncDec(UO);
-  }
-  bool VisitUnaryPostIncDec(const UnaryOperator *UO) {
-    if (!Info.getLangOpts().CPlusPlus14 && !Info.keepEvaluatingAfterFailure())
-      return Error(UO);
-
-    LValue LVal;
-    if (!EvaluateLValue(UO->getSubExpr(), LVal, Info))
-      return false;
-    APValue RVal;
-    if (!handleIncDec(this->Info, UO, LVal, UO->getSubExpr()->getType(),
-                      UO->isIncrementOp(), &RVal))
-      return false;
-    return DerivedSuccess(RVal, UO);
-  }
-
-  bool VisitStmtExpr(const StmtExpr *E) {
-    // We will have checked the full-expressions inside the statement expression
-    // when they were completed, and don't need to check them again now.
-    if (Info.checkingForOverflow())
-      return Error(E);
-
-    BlockScopeRAII Scope(Info);
-    const CompoundStmt *CS = E->getSubStmt();
-    if (CS->body_empty())
-      return true;
-
-    for (CompoundStmt::const_body_iterator BI = CS->body_begin(),
-                                           BE = CS->body_end();
-         /**/; ++BI) {
-      if (BI + 1 == BE) {
-        const Expr *FinalExpr = dyn_cast<Expr>(*BI);
-        if (!FinalExpr) {
-          Info.FFDiag((*BI)->getBeginLoc(),
-                      diag::note_constexpr_stmt_expr_unsupported);
-          return false;
-        }
-        return this->Visit(FinalExpr);
-      }
-
-      APValue ReturnValue;
-      StmtResult Result = { ReturnValue, nullptr };
-      EvalStmtResult ESR = EvaluateStmt(Result, Info, *BI);
-      if (ESR != ESR_Succeeded) {
-        // FIXME: If the statement-expression terminated due to 'return',
-        // 'break', or 'continue', it would be nice to propagate that to
-        // the outer statement evaluation rather than bailing out.
-        if (ESR != ESR_Failed)
-          Info.FFDiag((*BI)->getBeginLoc(),
-                      diag::note_constexpr_stmt_expr_unsupported);
-        return false;
-      }
-    }
-
-    llvm_unreachable("Return from function from the loop above.");
-  }
-
-  /// Visit a value which is evaluated, but whose value is ignored.
-  void VisitIgnoredValue(const Expr *E) {
-    EvaluateIgnoredValue(Info, E);
-  }
-
-  /// Potentially visit a MemberExpr's base expression.
-  void VisitIgnoredBaseExpression(const Expr *E) {
-    // While MSVC doesn't evaluate the base expression, it does diagnose the
-    // presence of side-effecting behavior.
-    if (Info.getLangOpts().MSVCCompat && !E->HasSideEffects(Info.Ctx))
-      return;
-    VisitIgnoredValue(E);
-  }
-};
-
-} // namespace
-
-//===----------------------------------------------------------------------===//
-// Common base class for lvalue and temporary evaluation.
-//===----------------------------------------------------------------------===//
-namespace {
-template<class Derived>
-class LValueExprEvaluatorBase
-  : public ExprEvaluatorBase<Derived> {
-protected:
-  LValue &Result;
-  bool InvalidBaseOK;
-  typedef LValueExprEvaluatorBase LValueExprEvaluatorBaseTy;
-  typedef ExprEvaluatorBase<Derived> ExprEvaluatorBaseTy;
-
-  bool Success(APValue::LValueBase B) {
-    Result.set(B);
-    return true;
-  }
-
-  bool evaluatePointer(const Expr *E, LValue &Result) {
-    return EvaluatePointer(E, Result, this->Info, InvalidBaseOK);
-  }
-
-public:
-  LValueExprEvaluatorBase(EvalInfo &Info, LValue &Result, bool InvalidBaseOK)
-      : ExprEvaluatorBaseTy(Info), Result(Result),
-        InvalidBaseOK(InvalidBaseOK) {}
-
-  bool Success(const APValue &V, const Expr *E) {
-    Result.setFrom(this->Info.Ctx, V);
-    return true;
-  }
-
-  bool VisitMemberExpr(const MemberExpr *E) {
-    // Handle non-static data members.
-    QualType BaseTy;
-    bool EvalOK;
-    if (E->isArrow()) {
-      EvalOK = evaluatePointer(E->getBase(), Result);
-      BaseTy = E->getBase()->getType()->castAs<PointerType>()->getPointeeType();
-    } else if (E->getBase()->isRValue()) {
-      assert(E->getBase()->getType()->isRecordType());
-      EvalOK = EvaluateTemporary(E->getBase(), Result, this->Info);
-      BaseTy = E->getBase()->getType();
-    } else {
-      EvalOK = this->Visit(E->getBase());
-      BaseTy = E->getBase()->getType();
-    }
-    if (!EvalOK) {
-      if (!InvalidBaseOK)
-        return false;
-      Result.setInvalid(E);
-      return true;
-    }
-
-    const ValueDecl *MD = E->getMemberDecl();
-    if (const FieldDecl *FD = dyn_cast<FieldDecl>(E->getMemberDecl())) {
-      assert(BaseTy->getAs<RecordType>()->getDecl()->getCanonicalDecl() ==
-             FD->getParent()->getCanonicalDecl() && "record / field mismatch");
-      (void)BaseTy;
-      if (!HandleLValueMember(this->Info, E, Result, FD))
-        return false;
-    } else if (const IndirectFieldDecl *IFD = dyn_cast<IndirectFieldDecl>(MD)) {
-      if (!HandleLValueIndirectMember(this->Info, E, Result, IFD))
-        return false;
-    } else
-      return this->Error(E);
-
-    if (MD->getType()->isReferenceType()) {
-      APValue RefValue;
-      if (!handleLValueToRValueConversion(this->Info, E, MD->getType(), Result,
-                                          RefValue))
-        return false;
-      return Success(RefValue, E);
-    }
-    return true;
-  }
-
-  bool VisitBinaryOperator(const BinaryOperator *E) {
-    switch (E->getOpcode()) {
-    default:
-      return ExprEvaluatorBaseTy::VisitBinaryOperator(E);
-
-    case BO_PtrMemD:
-    case BO_PtrMemI:
-      return HandleMemberPointerAccess(this->Info, E, Result);
-    }
-  }
-
-  bool VisitCastExpr(const CastExpr *E) {
-    switch (E->getCastKind()) {
-    default:
-      return ExprEvaluatorBaseTy::VisitCastExpr(E);
-
-    case CK_DerivedToBase:
-    case CK_UncheckedDerivedToBase:
-      if (!this->Visit(E->getSubExpr()))
-        return false;
-
-      // Now figure out the necessary offset to add to the base LV to get from
-      // the derived class to the base class.
-      return HandleLValueBasePath(this->Info, E, E->getSubExpr()->getType(),
-                                  Result);
-    }
-  }
-};
-}
-
-//===----------------------------------------------------------------------===//
-// LValue Evaluation
-//
-// This is used for evaluating lvalues (in C and C++), xvalues (in C++11),
-// function designators (in C), decl references to void objects (in C), and
-// temporaries (if building with -Wno-address-of-temporary).
-//
-// LValue evaluation produces values comprising a base expression of one of the
-// following types:
-// - Declarations
-//  * VarDecl
-//  * FunctionDecl
-// - Literals
-//  * CompoundLiteralExpr in C (and in global scope in C++)
-//  * StringLiteral
-//  * CXXTypeidExpr
-//  * PredefinedExpr
-//  * ObjCStringLiteralExpr
-//  * ObjCEncodeExpr
-//  * AddrLabelExpr
-//  * BlockExpr
-//  * CallExpr for a MakeStringConstant builtin
-// - Locals and temporaries
-//  * MaterializeTemporaryExpr
-//  * Any Expr, with a CallIndex indicating the function in which the temporary
-//    was evaluated, for cases where the MaterializeTemporaryExpr is missing
-//    from the AST (FIXME).
-//  * A MaterializeTemporaryExpr that has static storage duration, with no
-//    CallIndex, for a lifetime-extended temporary.
-// plus an offset in bytes.
-//===----------------------------------------------------------------------===//
-namespace {
-class LValueExprEvaluator
-  : public LValueExprEvaluatorBase<LValueExprEvaluator> {
-public:
-  LValueExprEvaluator(EvalInfo &Info, LValue &Result, bool InvalidBaseOK) :
-    LValueExprEvaluatorBaseTy(Info, Result, InvalidBaseOK) {}
-
-  bool VisitVarDecl(const Expr *E, const VarDecl *VD);
-  bool VisitUnaryPreIncDec(const UnaryOperator *UO);
-
-  bool VisitDeclRefExpr(const DeclRefExpr *E);
-  bool VisitPredefinedExpr(const PredefinedExpr *E) { return Success(E); }
-  bool VisitMaterializeTemporaryExpr(const MaterializeTemporaryExpr *E);
-  bool VisitCompoundLiteralExpr(const CompoundLiteralExpr *E);
-  bool VisitMemberExpr(const MemberExpr *E);
-  bool VisitStringLiteral(const StringLiteral *E) { return Success(E); }
-  bool VisitObjCEncodeExpr(const ObjCEncodeExpr *E) { return Success(E); }
-  bool VisitCXXTypeidExpr(const CXXTypeidExpr *E);
-  bool VisitCXXUuidofExpr(const CXXUuidofExpr *E);
-  bool VisitArraySubscriptExpr(const ArraySubscriptExpr *E);
-  bool VisitUnaryDeref(const UnaryOperator *E);
-  bool VisitUnaryReal(const UnaryOperator *E);
-  bool VisitUnaryImag(const UnaryOperator *E);
-  bool VisitUnaryPreInc(const UnaryOperator *UO) {
-    return VisitUnaryPreIncDec(UO);
-  }
-  bool VisitUnaryPreDec(const UnaryOperator *UO) {
-    return VisitUnaryPreIncDec(UO);
-  }
-  bool VisitBinAssign(const BinaryOperator *BO);
-  bool VisitCompoundAssignOperator(const CompoundAssignOperator *CAO);
-
-  bool VisitCastExpr(const CastExpr *E) {
-    switch (E->getCastKind()) {
-    default:
-      return LValueExprEvaluatorBaseTy::VisitCastExpr(E);
-
-    case CK_LValueBitCast:
-      this->CCEDiag(E, diag::note_constexpr_invalid_cast) << 2;
-      if (!Visit(E->getSubExpr()))
-        return false;
-      Result.Designator.setInvalid();
-      return true;
-
-    case CK_BaseToDerived:
-      if (!Visit(E->getSubExpr()))
-        return false;
-      return HandleBaseToDerivedCast(Info, E, Result);
-    }
-  }
-};
-} // end anonymous namespace
-
-/// Evaluate an expression as an lvalue. This can be legitimately called on
-/// expressions which are not glvalues, in three cases:
-///  * function designators in C, and
-///  * "extern void" objects
-///  * @selector() expressions in Objective-C
-static bool EvaluateLValue(const Expr *E, LValue &Result, EvalInfo &Info,
-                           bool InvalidBaseOK) {
-  assert(E->isGLValue() || E->getType()->isFunctionType() ||
-         E->getType()->isVoidType() || isa<ObjCSelectorExpr>(E));
-  return LValueExprEvaluator(Info, Result, InvalidBaseOK).Visit(E);
-}
-
-bool LValueExprEvaluator::VisitDeclRefExpr(const DeclRefExpr *E) {
-  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(E->getDecl()))
-    return Success(FD);
-  if (const VarDecl *VD = dyn_cast<VarDecl>(E->getDecl()))
-    return VisitVarDecl(E, VD);
-  if (const BindingDecl *BD = dyn_cast<BindingDecl>(E->getDecl()))
-    return Visit(BD->getBinding());
-  return Error(E);
-}
-
-
-bool LValueExprEvaluator::VisitVarDecl(const Expr *E, const VarDecl *VD) {
-
-  // If we are within a lambda's call operator, check whether the 'VD' referred
-  // to within 'E' actually represents a lambda-capture that maps to a
-  // data-member/field within the closure object, and if so, evaluate to the
-  // field or what the field refers to.
-  if (Info.CurrentCall && isLambdaCallOperator(Info.CurrentCall->Callee) &&
-      isa<DeclRefExpr>(E) &&
-      cast<DeclRefExpr>(E)->refersToEnclosingVariableOrCapture()) {
-    // We don't always have a complete capture-map when checking or inferring if
-    // the function call operator meets the requirements of a constexpr function
-    // - but we don't need to evaluate the captures to determine constexprness
-    // (dcl.constexpr C++17).
-    if (Info.checkingPotentialConstantExpression())
-      return false;
-
-    if (auto *FD = Info.CurrentCall->LambdaCaptureFields.lookup(VD)) {
-      // Start with 'Result' referring to the complete closure object...
-      Result = *Info.CurrentCall->This;
-      // ... then update it to refer to the field of the closure object
-      // that represents the capture.
-      if (!HandleLValueMember(Info, E, Result, FD))
-        return false;
-      // And if the field is of reference type, update 'Result' to refer to what
-      // the field refers to.
-      if (FD->getType()->isReferenceType()) {
-        APValue RVal;
-        if (!handleLValueToRValueConversion(Info, E, FD->getType(), Result,
-                                            RVal))
-          return false;
-        Result.setFrom(Info.Ctx, RVal);
-      }
-      return true;
-    }
-  }
-  CallStackFrame *Frame = nullptr;
-  if (VD->hasLocalStorage() && Info.CurrentCall->Index > 1) {
-    // Only if a local variable was declared in the function currently being
-    // evaluated, do we expect to be able to find its value in the current
-    // frame. (Otherwise it was likely declared in an enclosing context and
-    // could either have a valid evaluatable value (for e.g. a constexpr
-    // variable) or be ill-formed (and trigger an appropriate evaluation
-    // diagnostic)).
-    if (Info.CurrentCall->Callee &&
-        Info.CurrentCall->Callee->Equals(VD->getDeclContext())) {
-      Frame = Info.CurrentCall;
-    }
-  }
-
-  if (!VD->getType()->isReferenceType()) {
-    if (Frame) {
-      Result.set({VD, Frame->Index,
-                  Info.CurrentCall->getCurrentTemporaryVersion(VD)});
-      return true;
-    }
-    return Success(VD);
-  }
-
-  APValue *V;
-  if (!evaluateVarDeclInit(Info, E, VD, Frame, V, nullptr))
-    return false;
-  if (V->isUninit()) {
-    if (!Info.checkingPotentialConstantExpression())
-      Info.FFDiag(E, diag::note_constexpr_use_uninit_reference);
-    return false;
-  }
-  return Success(*V, E);
-}
-
-bool LValueExprEvaluator::VisitMaterializeTemporaryExpr(
-    const MaterializeTemporaryExpr *E) {
-  // Walk through the expression to find the materialized temporary itself.
-  SmallVector<const Expr *, 2> CommaLHSs;
-  SmallVector<SubobjectAdjustment, 2> Adjustments;
-  const Expr *Inner = E->GetTemporaryExpr()->
-      skipRValueSubobjectAdjustments(CommaLHSs, Adjustments);
-
-  // If we passed any comma operators, evaluate their LHSs.
-  for (unsigned I = 0, N = CommaLHSs.size(); I != N; ++I)
-    if (!EvaluateIgnoredValue(Info, CommaLHSs[I]))
-      return false;
-
-  // A materialized temporary with static storage duration can appear within the
-  // result of a constant expression evaluation, so we need to preserve its
-  // value for use outside this evaluation.
-  APValue *Value;
-  if (E->getStorageDuration() == SD_Static) {
-    Value = Info.Ctx.getMaterializedTemporaryValue(E, true);
-    *Value = APValue();
-    Result.set(E);
-  } else {
-    Value = &createTemporary(E, E->getStorageDuration() == SD_Automatic, Result,
-                             *Info.CurrentCall);
-  }
-
-  QualType Type = Inner->getType();
-
-  // Materialize the temporary itself.
-  if (!EvaluateInPlace(*Value, Info, Result, Inner) ||
-      (E->getStorageDuration() == SD_Static &&
-       !CheckConstantExpression(Info, E->getExprLoc(), Type, *Value))) {
-    *Value = APValue();
-    return false;
-  }
-
-  // Adjust our lvalue to refer to the desired subobject.
-  for (unsigned I = Adjustments.size(); I != 0; /**/) {
-    --I;
-    switch (Adjustments[I].Kind) {
-    case SubobjectAdjustment::DerivedToBaseAdjustment:
-      if (!HandleLValueBasePath(Info, Adjustments[I].DerivedToBase.BasePath,
-                                Type, Result))
-        return false;
-      Type = Adjustments[I].DerivedToBase.BasePath->getType();
-      break;
-
-    case SubobjectAdjustment::FieldAdjustment:
-      if (!HandleLValueMember(Info, E, Result, Adjustments[I].Field))
-        return false;
-      Type = Adjustments[I].Field->getType();
-      break;
-
-    case SubobjectAdjustment::MemberPointerAdjustment:
-      if (!HandleMemberPointerAccess(this->Info, Type, Result,
-                                     Adjustments[I].Ptr.RHS))
-        return false;
-      Type = Adjustments[I].Ptr.MPT->getPointeeType();
-      break;
-    }
-  }
-
-  return true;
-}
-
-bool
-LValueExprEvaluator::VisitCompoundLiteralExpr(const CompoundLiteralExpr *E) {
-  assert((!Info.getLangOpts().CPlusPlus || E->isFileScope()) &&
-         "lvalue compound literal in c++?");
-  // Defer visiting the literal until the lvalue-to-rvalue conversion. We can
-  // only see this when folding in C, so there's no standard to follow here.
-  return Success(E);
-}
-
-bool LValueExprEvaluator::VisitCXXTypeidExpr(const CXXTypeidExpr *E) {
-  if (!E->isPotentiallyEvaluated())
-    return Success(E);
-
-  Info.FFDiag(E, diag::note_constexpr_typeid_polymorphic)
-    << E->getExprOperand()->getType()
-    << E->getExprOperand()->getSourceRange();
-  return false;
-}
-
-bool LValueExprEvaluator::VisitCXXUuidofExpr(const CXXUuidofExpr *E) {
-  return Success(E);
-}
-
-bool LValueExprEvaluator::VisitMemberExpr(const MemberExpr *E) {
-  // Handle static data members.
-  if (const VarDecl *VD = dyn_cast<VarDecl>(E->getMemberDecl())) {
-    VisitIgnoredBaseExpression(E->getBase());
-    return VisitVarDecl(E, VD);
-  }
-
-  // Handle static member functions.
-  if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(E->getMemberDecl())) {
-    if (MD->isStatic()) {
-      VisitIgnoredBaseExpression(E->getBase());
-      return Success(MD);
-    }
-  }
-
-  // Handle non-static data members.
-  return LValueExprEvaluatorBaseTy::VisitMemberExpr(E);
-}
-
-bool LValueExprEvaluator::VisitArraySubscriptExpr(const ArraySubscriptExpr *E) {
-  // FIXME: Deal with vectors as array subscript bases.
-  if (E->getBase()->getType()->isVectorType())
-    return Error(E);
-
-  bool Success = true;
-  if (!evaluatePointer(E->getBase(), Result)) {
-    if (!Info.noteFailure())
-      return false;
-    Success = false;
-  }
-
-  APSInt Index;
-  if (!EvaluateInteger(E->getIdx(), Index, Info))
-    return false;
-
-  return Success &&
-         HandleLValueArrayAdjustment(Info, E, Result, E->getType(), Index);
-}
-
-bool LValueExprEvaluator::VisitUnaryDeref(const UnaryOperator *E) {
-  return evaluatePointer(E->getSubExpr(), Result);
-}
-
-bool LValueExprEvaluator::VisitUnaryReal(const UnaryOperator *E) {
-  if (!Visit(E->getSubExpr()))
-    return false;
-  // __real is a no-op on scalar lvalues.
-  if (E->getSubExpr()->getType()->isAnyComplexType())
-    HandleLValueComplexElement(Info, E, Result, E->getType(), false);
-  return true;
-}
-
-bool LValueExprEvaluator::VisitUnaryImag(const UnaryOperator *E) {
-  assert(E->getSubExpr()->getType()->isAnyComplexType() &&
-         "lvalue __imag__ on scalar?");
-  if (!Visit(E->getSubExpr()))
-    return false;
-  HandleLValueComplexElement(Info, E, Result, E->getType(), true);
-  return true;
-}
-
-bool LValueExprEvaluator::VisitUnaryPreIncDec(const UnaryOperator *UO) {
-  if (!Info.getLangOpts().CPlusPlus14 && !Info.keepEvaluatingAfterFailure())
-    return Error(UO);
-
-  if (!this->Visit(UO->getSubExpr()))
-    return false;
-
-  return handleIncDec(
-      this->Info, UO, Result, UO->getSubExpr()->getType(),
-      UO->isIncrementOp(), nullptr);
-}
-
-bool LValueExprEvaluator::VisitCompoundAssignOperator(
-    const CompoundAssignOperator *CAO) {
-  if (!Info.getLangOpts().CPlusPlus14 && !Info.keepEvaluatingAfterFailure())
-    return Error(CAO);
-
-  APValue RHS;
-
-  // The overall lvalue result is the result of evaluating the LHS.
-  if (!this->Visit(CAO->getLHS())) {
-    if (Info.noteFailure())
-      Evaluate(RHS, this->Info, CAO->getRHS());
-    return false;
-  }
-
-  if (!Evaluate(RHS, this->Info, CAO->getRHS()))
-    return false;
-
-  return handleCompoundAssignment(
-      this->Info, CAO,
-      Result, CAO->getLHS()->getType(), CAO->getComputationLHSType(),
-      CAO->getOpForCompoundAssignment(CAO->getOpcode()), RHS);
-}
-
-bool LValueExprEvaluator::VisitBinAssign(const BinaryOperator *E) {
-  if (!Info.getLangOpts().CPlusPlus14 && !Info.keepEvaluatingAfterFailure())
-    return Error(E);
-
-  APValue NewVal;
-
-  if (!this->Visit(E->getLHS())) {
-    if (Info.noteFailure())
-      Evaluate(NewVal, this->Info, E->getRHS());
-    return false;
-  }
-
-  if (!Evaluate(NewVal, this->Info, E->getRHS()))
-    return false;
-
-  return handleAssignment(this->Info, E, Result, E->getLHS()->getType(),
-                          NewVal);
-}
-
-//===----------------------------------------------------------------------===//
-// Pointer Evaluation
-//===----------------------------------------------------------------------===//
-
-/// Attempts to compute the number of bytes available at the pointer
-/// returned by a function with the alloc_size attribute. Returns true if we
-/// were successful. Places an unsigned number into `Result`.
-///
-/// This expects the given CallExpr to be a call to a function with an
-/// alloc_size attribute.
-static bool getBytesReturnedByAllocSizeCall(const ASTContext &Ctx,
-                                            const CallExpr *Call,
-                                            llvm::APInt &Result) {
-  const AllocSizeAttr *AllocSize = getAllocSizeAttr(Call);
-
-  assert(AllocSize && AllocSize->getElemSizeParam().isValid());
-  unsigned SizeArgNo = AllocSize->getElemSizeParam().getASTIndex();
-  unsigned BitsInSizeT = Ctx.getTypeSize(Ctx.getSizeType());
-  if (Call->getNumArgs() <= SizeArgNo)
-    return false;
-
-  auto EvaluateAsSizeT = [&](const Expr *E, APSInt &Into) {
-    Expr::EvalResult ExprResult;
-    if (!E->EvaluateAsInt(ExprResult, Ctx, Expr::SE_AllowSideEffects))
-      return false;
-    Into = ExprResult.Val.getInt();
-    if (Into.isNegative() || !Into.isIntN(BitsInSizeT))
-      return false;
-    Into = Into.zextOrSelf(BitsInSizeT);
-    return true;
-  };
-
-  APSInt SizeOfElem;
-  if (!EvaluateAsSizeT(Call->getArg(SizeArgNo), SizeOfElem))
-    return false;
-
-  if (!AllocSize->getNumElemsParam().isValid()) {
-    Result = std::move(SizeOfElem);
-    return true;
-  }
-
-  APSInt NumberOfElems;
-  unsigned NumArgNo = AllocSize->getNumElemsParam().getASTIndex();
-  if (!EvaluateAsSizeT(Call->getArg(NumArgNo), NumberOfElems))
-    return false;
-
-  bool Overflow;
-  llvm::APInt BytesAvailable = SizeOfElem.umul_ov(NumberOfElems, Overflow);
-  if (Overflow)
-    return false;
-
-  Result = std::move(BytesAvailable);
-  return true;
-}
-
-/// Convenience function. LVal's base must be a call to an alloc_size
-/// function.
-static bool getBytesReturnedByAllocSizeCall(const ASTContext &Ctx,
-                                            const LValue &LVal,
-                                            llvm::APInt &Result) {
-  assert(isBaseAnAllocSizeCall(LVal.getLValueBase()) &&
-         "Can't get the size of a non alloc_size function");
-  const auto *Base = LVal.getLValueBase().get<const Expr *>();
-  const CallExpr *CE = tryUnwrapAllocSizeCall(Base);
-  return getBytesReturnedByAllocSizeCall(Ctx, CE, Result);
-}
-
-/// Attempts to evaluate the given LValueBase as the result of a call to
-/// a function with the alloc_size attribute. If it was possible to do so, this
-/// function will return true, make Result's Base point to said function call,
-/// and mark Result's Base as invalid.
-static bool evaluateLValueAsAllocSize(EvalInfo &Info, APValue::LValueBase Base,
-                                      LValue &Result) {
-  if (Base.isNull())
-    return false;
-
-  // Because we do no form of static analysis, we only support const variables.
-  //
-  // Additionally, we can't support parameters, nor can we support static
-  // variables (in the latter case, use-before-assign isn't UB; in the former,
-  // we have no clue what they'll be assigned to).
-  const auto *VD =
-      dyn_cast_or_null<VarDecl>(Base.dyn_cast<const ValueDecl *>());
-  if (!VD || !VD->isLocalVarDecl() || !VD->getType().isConstQualified())
-    return false;
-
-  const Expr *Init = VD->getAnyInitializer();
-  if (!Init)
-    return false;
-
-  const Expr *E = Init->IgnoreParens();
-  if (!tryUnwrapAllocSizeCall(E))
-    return false;
-
-  // Store E instead of E unwrapped so that the type of the LValue's base is
-  // what the user wanted.
-  Result.setInvalid(E);
-
-  QualType Pointee = E->getType()->castAs<PointerType>()->getPointeeType();
-  Result.addUnsizedArray(Info, E, Pointee);
-  return true;
-}
-
-namespace {
-class PointerExprEvaluator
-  : public ExprEvaluatorBase<PointerExprEvaluator> {
-  LValue &Result;
-  bool InvalidBaseOK;
-
-  bool Success(const Expr *E) {
-    Result.set(E);
-    return true;
-  }
-
-  bool evaluateLValue(const Expr *E, LValue &Result) {
-    return EvaluateLValue(E, Result, Info, InvalidBaseOK);
-  }
-
-  bool evaluatePointer(const Expr *E, LValue &Result) {
-    return EvaluatePointer(E, Result, Info, InvalidBaseOK);
-  }
-
-  bool visitNonBuiltinCallExpr(const CallExpr *E);
-public:
-
-  PointerExprEvaluator(EvalInfo &info, LValue &Result, bool InvalidBaseOK)
-      : ExprEvaluatorBaseTy(info), Result(Result),
-        InvalidBaseOK(InvalidBaseOK) {}
-
-  bool Success(const APValue &V, const Expr *E) {
-    Result.setFrom(Info.Ctx, V);
-    return true;
-  }
-  bool ZeroInitialization(const Expr *E) {
-    auto TargetVal = Info.Ctx.getTargetNullPointerValue(E->getType());
-    Result.setNull(E->getType(), TargetVal);
-    return true;
-  }
-
-  bool VisitBinaryOperator(const BinaryOperator *E);
-  bool VisitCastExpr(const CastExpr* E);
-  bool VisitUnaryAddrOf(const UnaryOperator *E);
-  bool VisitObjCStringLiteral(const ObjCStringLiteral *E)
-      { return Success(E); }
-  bool VisitObjCBoxedExpr(const ObjCBoxedExpr *E) {
-    if (Info.noteFailure())
-      EvaluateIgnoredValue(Info, E->getSubExpr());
-    return Error(E);
-  }
-  bool VisitAddrLabelExpr(const AddrLabelExpr *E)
-      { return Success(E); }
-  bool VisitCallExpr(const CallExpr *E);
-  bool VisitBuiltinCallExpr(const CallExpr *E, unsigned BuiltinOp);
-  bool VisitBlockExpr(const BlockExpr *E) {
-    if (!E->getBlockDecl()->hasCaptures())
-      return Success(E);
-    return Error(E);
-  }
-  bool VisitCXXThisExpr(const CXXThisExpr *E) {
-    // Can't look at 'this' when checking a potential constant expression.
-    if (Info.checkingPotentialConstantExpression())
-      return false;
-    if (!Info.CurrentCall->This) {
-      if (Info.getLangOpts().CPlusPlus11)
-        Info.FFDiag(E, diag::note_constexpr_this) << E->isImplicit();
-      else
-        Info.FFDiag(E);
-      return false;
-    }
-    Result = *Info.CurrentCall->This;
-    // If we are inside a lambda's call operator, the 'this' expression refers
-    // to the enclosing '*this' object (either by value or reference) which is
-    // either copied into the closure object's field that represents the '*this'
-    // or refers to '*this'.
-    if (isLambdaCallOperator(Info.CurrentCall->Callee)) {
-      // Update 'Result' to refer to the data member/field of the closure object
-      // that represents the '*this' capture.
-      if (!HandleLValueMember(Info, E, Result,
-                             Info.CurrentCall->LambdaThisCaptureField))
-        return false;
-      // If we captured '*this' by reference, replace the field with its referent.
-      if (Info.CurrentCall->LambdaThisCaptureField->getType()
-              ->isPointerType()) {
-        APValue RVal;
-        if (!handleLValueToRValueConversion(Info, E, E->getType(), Result,
-                                            RVal))
-          return false;
-
-        Result.setFrom(Info.Ctx, RVal);
-      }
-    }
-    return true;
-  }
-
-  // FIXME: Missing: @protocol, @selector
-};
-} // end anonymous namespace
-
-static bool EvaluatePointer(const Expr* E, LValue& Result, EvalInfo &Info,
-                            bool InvalidBaseOK) {
-  assert(E->isRValue() && E->getType()->hasPointerRepresentation());
-  return PointerExprEvaluator(Info, Result, InvalidBaseOK).Visit(E);
-}
-
-bool PointerExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) {
-  if (E->getOpcode() != BO_Add &&
-      E->getOpcode() != BO_Sub)
-    return ExprEvaluatorBaseTy::VisitBinaryOperator(E);
-
-  const Expr *PExp = E->getLHS();
-  const Expr *IExp = E->getRHS();
-  if (IExp->getType()->isPointerType())
-    std::swap(PExp, IExp);
-
-  bool EvalPtrOK = evaluatePointer(PExp, Result);
-  if (!EvalPtrOK && !Info.noteFailure())
-    return false;
-
-  llvm::APSInt Offset;
-  if (!EvaluateInteger(IExp, Offset, Info) || !EvalPtrOK)
-    return false;
-
-  if (E->getOpcode() == BO_Sub)
-    negateAsSigned(Offset);
-
-  QualType Pointee = PExp->getType()->castAs<PointerType>()->getPointeeType();
-  return HandleLValueArrayAdjustment(Info, E, Result, Pointee, Offset);
-}
-
-bool PointerExprEvaluator::VisitUnaryAddrOf(const UnaryOperator *E) {
-  return evaluateLValue(E->getSubExpr(), Result);
-}
-
-bool PointerExprEvaluator::VisitCastExpr(const CastExpr *E) {
-  const Expr *SubExpr = E->getSubExpr();
-
-  switch (E->getCastKind()) {
-  default:
-    break;
-
-  case CK_BitCast:
-  case CK_CPointerToObjCPointerCast:
-  case CK_BlockPointerToObjCPointerCast:
-  case CK_AnyPointerToBlockPointerCast:
-  case CK_AddressSpaceConversion:
-    if (!Visit(SubExpr))
-      return false;
-    // Bitcasts to cv void* are static_casts, not reinterpret_casts, so are
-    // permitted in constant expressions in C++11. Bitcasts from cv void* are
-    // also static_casts, but we disallow them as a resolution to DR1312.
-    if (!E->getType()->isVoidPointerType()) {
-      Result.Designator.setInvalid();
-      if (SubExpr->getType()->isVoidPointerType())
-        CCEDiag(E, diag::note_constexpr_invalid_cast)
-          << 3 << SubExpr->getType();
-      else
-        CCEDiag(E, diag::note_constexpr_invalid_cast) << 2;
-    }
-    if (E->getCastKind() == CK_AddressSpaceConversion && Result.IsNullPtr)
-      ZeroInitialization(E);
-    return true;
-
-  case CK_DerivedToBase:
-  case CK_UncheckedDerivedToBase:
-    if (!evaluatePointer(E->getSubExpr(), Result))
-      return false;
-    if (!Result.Base && Result.Offset.isZero())
-      return true;
-
-    // Now figure out the necessary offset to add to the base LV to get from
-    // the derived class to the base class.
-    return HandleLValueBasePath(Info, E, E->getSubExpr()->getType()->
-                                  castAs<PointerType>()->getPointeeType(),
-                                Result);
-
-  case CK_BaseToDerived:
-    if (!Visit(E->getSubExpr()))
-      return false;
-    if (!Result.Base && Result.Offset.isZero())
-      return true;
-    return HandleBaseToDerivedCast(Info, E, Result);
-
-  case CK_NullToPointer:
-    VisitIgnoredValue(E->getSubExpr());
-    return ZeroInitialization(E);
-
-  case CK_IntegralToPointer: {
-    CCEDiag(E, diag::note_constexpr_invalid_cast) << 2;
-
-    APValue Value;
-    if (!EvaluateIntegerOrLValue(SubExpr, Value, Info))
-      break;
-
-    if (Value.isInt()) {
-      unsigned Size = Info.Ctx.getTypeSize(E->getType());
-      uint64_t N = Value.getInt().extOrTrunc(Size).getZExtValue();
-      Result.Base = (Expr*)nullptr;
-      Result.InvalidBase = false;
-      Result.Offset = CharUnits::fromQuantity(N);
-      Result.Designator.setInvalid();
-      Result.IsNullPtr = false;
-      return true;
-    } else {
-      // Cast is of an lvalue, no need to change value.
-      Result.setFrom(Info.Ctx, Value);
-      return true;
-    }
-  }
-
-  case CK_ArrayToPointerDecay: {
-    if (SubExpr->isGLValue()) {
-      if (!evaluateLValue(SubExpr, Result))
-        return false;
-    } else {
-      APValue &Value = createTemporary(SubExpr, false, Result,
-                                       *Info.CurrentCall);
-      if (!EvaluateInPlace(Value, Info, Result, SubExpr))
-        return false;
-    }
-    // The result is a pointer to the first element of the array.
-    auto *AT = Info.Ctx.getAsArrayType(SubExpr->getType());
-    if (auto *CAT = dyn_cast<ConstantArrayType>(AT))
-      Result.addArray(Info, E, CAT);
-    else
-      Result.addUnsizedArray(Info, E, AT->getElementType());
-    return true;
-  }
-
-  case CK_FunctionToPointerDecay:
-    return evaluateLValue(SubExpr, Result);
-
-  case CK_LValueToRValue: {
-    LValue LVal;
-    if (!evaluateLValue(E->getSubExpr(), LVal))
-      return false;
-
-    APValue RVal;
-    // Note, we use the subexpression's type in order to retain cv-qualifiers.
-    if (!handleLValueToRValueConversion(Info, E, E->getSubExpr()->getType(),
-                                        LVal, RVal))
-      return InvalidBaseOK &&
-             evaluateLValueAsAllocSize(Info, LVal.Base, Result);
-    return Success(RVal, E);
-  }
-  }
-
-  return ExprEvaluatorBaseTy::VisitCastExpr(E);
-}
-
-static CharUnits GetAlignOfType(EvalInfo &Info, QualType T,
-                                UnaryExprOrTypeTrait ExprKind) {
-  // C++ [expr.alignof]p3:
-  //     When alignof is applied to a reference type, the result is the
-  //     alignment of the referenced type.
-  if (const ReferenceType *Ref = T->getAs<ReferenceType>())
-    T = Ref->getPointeeType();
-
-  if (T.getQualifiers().hasUnaligned())
-    return CharUnits::One();
-
-  const bool AlignOfReturnsPreferred =
-      Info.Ctx.getLangOpts().getClangABICompat() <= LangOptions::ClangABI::Ver7;
-
-  // __alignof is defined to return the preferred alignment.
-  // Before 8, clang returned the preferred alignment for alignof and _Alignof
-  // as well.
-  if (ExprKind == UETT_PreferredAlignOf || AlignOfReturnsPreferred)
-    return Info.Ctx.toCharUnitsFromBits(
-      Info.Ctx.getPreferredTypeAlign(T.getTypePtr()));
-  // alignof and _Alignof are defined to return the ABI alignment.
-  else if (ExprKind == UETT_AlignOf)
-    return Info.Ctx.getTypeAlignInChars(T.getTypePtr());
-  else
-    llvm_unreachable("GetAlignOfType on a non-alignment ExprKind");
-}
-
-static CharUnits GetAlignOfExpr(EvalInfo &Info, const Expr *E,
-                                UnaryExprOrTypeTrait ExprKind) {
-  E = E->IgnoreParens();
-
-  // The kinds of expressions that we have special-case logic here for
-  // should be kept up to date with the special checks for those
-  // expressions in Sema.
-
-  // alignof decl is always accepted, even if it doesn't make sense: we default
-  // to 1 in those cases.
-  if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E))
-    return Info.Ctx.getDeclAlign(DRE->getDecl(),
-                                 /*RefAsPointee*/true);
-
-  if (const MemberExpr *ME = dyn_cast<MemberExpr>(E))
-    return Info.Ctx.getDeclAlign(ME->getMemberDecl(),
-                                 /*RefAsPointee*/true);
-
-  return GetAlignOfType(Info, E->getType(), ExprKind);
-}
-
-// To be clear: this happily visits unsupported builtins. Better name welcomed.
-bool PointerExprEvaluator::visitNonBuiltinCallExpr(const CallExpr *E) {
-  if (ExprEvaluatorBaseTy::VisitCallExpr(E))
-    return true;
-
-  if (!(InvalidBaseOK && getAllocSizeAttr(E)))
-    return false;
-
-  Result.setInvalid(E);
-  QualType PointeeTy = E->getType()->castAs<PointerType>()->getPointeeType();
-  Result.addUnsizedArray(Info, E, PointeeTy);
-  return true;
-}
-
-bool PointerExprEvaluator::VisitCallExpr(const CallExpr *E) {
-  if (IsStringLiteralCall(E))
-    return Success(E);
-
-  if (unsigned BuiltinOp = E->getBuiltinCallee())
-    return VisitBuiltinCallExpr(E, BuiltinOp);
-
-  return visitNonBuiltinCallExpr(E);
-}
-
-bool PointerExprEvaluator::VisitBuiltinCallExpr(const CallExpr *E,
-                                                unsigned BuiltinOp) {
-  switch (BuiltinOp) {
-  case Builtin::BI__builtin_addressof:
-    return evaluateLValue(E->getArg(0), Result);
-  case Builtin::BI__builtin_assume_aligned: {
-    // We need to be very careful here because: if the pointer does not have the
-    // asserted alignment, then the behavior is undefined, and undefined
-    // behavior is non-constant.
-    if (!evaluatePointer(E->getArg(0), Result))
-      return false;
-
-    LValue OffsetResult(Result);
-    APSInt Alignment;
-    if (!EvaluateInteger(E->getArg(1), Alignment, Info))
-      return false;
-    CharUnits Align = CharUnits::fromQuantity(Alignment.getZExtValue());
-
-    if (E->getNumArgs() > 2) {
-      APSInt Offset;
-      if (!EvaluateInteger(E->getArg(2), Offset, Info))
-        return false;
-
-      int64_t AdditionalOffset = -Offset.getZExtValue();
-      OffsetResult.Offset += CharUnits::fromQuantity(AdditionalOffset);
-    }
-
-    // If there is a base object, then it must have the correct alignment.
-    if (OffsetResult.Base) {
-      CharUnits BaseAlignment;
-      if (const ValueDecl *VD =
-          OffsetResult.Base.dyn_cast<const ValueDecl*>()) {
-        BaseAlignment = Info.Ctx.getDeclAlign(VD);
-      } else {
-        BaseAlignment = GetAlignOfExpr(
-            Info, OffsetResult.Base.get<const Expr *>(), UETT_AlignOf);
-      }
-
-      if (BaseAlignment < Align) {
-        Result.Designator.setInvalid();
-        // FIXME: Add support to Diagnostic for long / long long.
-        CCEDiag(E->getArg(0),
-                diag::note_constexpr_baa_insufficient_alignment) << 0
-          << (unsigned)BaseAlignment.getQuantity()
-          << (unsigned)Align.getQuantity();
-        return false;
-      }
-    }
-
-    // The offset must also have the correct alignment.
-    if (OffsetResult.Offset.alignTo(Align) != OffsetResult.Offset) {
-      Result.Designator.setInvalid();
-
-      (OffsetResult.Base
-           ? CCEDiag(E->getArg(0),
-                     diag::note_constexpr_baa_insufficient_alignment) << 1
-           : CCEDiag(E->getArg(0),
-                     diag::note_constexpr_baa_value_insufficient_alignment))
-        << (int)OffsetResult.Offset.getQuantity()
-        << (unsigned)Align.getQuantity();
-      return false;
-    }
-
-    return true;
-  }
-  case Builtin::BI__builtin_launder:
-    return evaluatePointer(E->getArg(0), Result);
-  case Builtin::BIstrchr:
-  case Builtin::BIwcschr:
-  case Builtin::BImemchr:
-  case Builtin::BIwmemchr:
-    if (Info.getLangOpts().CPlusPlus11)
-      Info.CCEDiag(E, diag::note_constexpr_invalid_function)
-        << /*isConstexpr*/0 << /*isConstructor*/0
-        << (std::string("'") + Info.Ctx.BuiltinInfo.getName(BuiltinOp) + "'");
-    else
-      Info.CCEDiag(E, diag::note_invalid_subexpr_in_const_expr);
-    LLVM_FALLTHROUGH;
-  case Builtin::BI__builtin_strchr:
-  case Builtin::BI__builtin_wcschr:
-  case Builtin::BI__builtin_memchr:
-  case Builtin::BI__builtin_char_memchr:
-  case Builtin::BI__builtin_wmemchr: {
-    if (!Visit(E->getArg(0)))
-      return false;
-    APSInt Desired;
-    if (!EvaluateInteger(E->getArg(1), Desired, Info))
-      return false;
-    uint64_t MaxLength = uint64_t(-1);
-    if (BuiltinOp != Builtin::BIstrchr &&
-        BuiltinOp != Builtin::BIwcschr &&
-        BuiltinOp != Builtin::BI__builtin_strchr &&
-        BuiltinOp != Builtin::BI__builtin_wcschr) {
-      APSInt N;
-      if (!EvaluateInteger(E->getArg(2), N, Info))
-        return false;
-      MaxLength = N.getExtValue();
-    }
-    // We cannot find the value if there are no candidates to match against.
-    if (MaxLength == 0u)
-      return ZeroInitialization(E);
-    if (!Result.checkNullPointerForFoldAccess(Info, E, AK_Read) ||
-        Result.Designator.Invalid)
-      return false;
-    QualType CharTy = Result.Designator.getType(Info.Ctx);
-    bool IsRawByte = BuiltinOp == Builtin::BImemchr ||
-                     BuiltinOp == Builtin::BI__builtin_memchr;
-    assert(IsRawByte ||
-           Info.Ctx.hasSameUnqualifiedType(
-               CharTy, E->getArg(0)->getType()->getPointeeType()));
-    // Pointers to const void may point to objects of incomplete type.
-    if (IsRawByte && CharTy->isIncompleteType()) {
-      Info.FFDiag(E, diag::note_constexpr_ltor_incomplete_type) << CharTy;
-      return false;
-    }
-    // Give up on byte-oriented matching against multibyte elements.
-    // FIXME: We can compare the bytes in the correct order.
-    if (IsRawByte && Info.Ctx.getTypeSizeInChars(CharTy) != CharUnits::One())
-      return false;
-    // Figure out what value we're actually looking for (after converting to
-    // the corresponding unsigned type if necessary).
-    uint64_t DesiredVal;
-    bool StopAtNull = false;
-    switch (BuiltinOp) {
-    case Builtin::BIstrchr:
-    case Builtin::BI__builtin_strchr:
-      // strchr compares directly to the passed integer, and therefore
-      // always fails if given an int that is not a char.
-      if (!APSInt::isSameValue(HandleIntToIntCast(Info, E, CharTy,
-                                                  E->getArg(1)->getType(),
-                                                  Desired),
-                               Desired))
-        return ZeroInitialization(E);
-      StopAtNull = true;
-      LLVM_FALLTHROUGH;
-    case Builtin::BImemchr:
-    case Builtin::BI__builtin_memchr:
-    case Builtin::BI__builtin_char_memchr:
-      // memchr compares by converting both sides to unsigned char. That's also
-      // correct for strchr if we get this far (to cope with plain char being
-      // unsigned in the strchr case).
-      DesiredVal = Desired.trunc(Info.Ctx.getCharWidth()).getZExtValue();
-      break;
-
-    case Builtin::BIwcschr:
-    case Builtin::BI__builtin_wcschr:
-      StopAtNull = true;
-      LLVM_FALLTHROUGH;
-    case Builtin::BIwmemchr:
-    case Builtin::BI__builtin_wmemchr:
-      // wcschr and wmemchr are given a wchar_t to look for. Just use it.
-      DesiredVal = Desired.getZExtValue();
-      break;
-    }
-
-    for (; MaxLength; --MaxLength) {
-      APValue Char;
-      if (!handleLValueToRValueConversion(Info, E, CharTy, Result, Char) ||
-          !Char.isInt())
-        return false;
-      if (Char.getInt().getZExtValue() == DesiredVal)
-        return true;
-      if (StopAtNull && !Char.getInt())
-        break;
-      if (!HandleLValueArrayAdjustment(Info, E, Result, CharTy, 1))
-        return false;
-    }
-    // Not found: return nullptr.
-    return ZeroInitialization(E);
-  }
-
-  case Builtin::BImemcpy:
-  case Builtin::BImemmove:
-  case Builtin::BIwmemcpy:
-  case Builtin::BIwmemmove:
-    if (Info.getLangOpts().CPlusPlus11)
-      Info.CCEDiag(E, diag::note_constexpr_invalid_function)
-        << /*isConstexpr*/0 << /*isConstructor*/0
-        << (std::string("'") + Info.Ctx.BuiltinInfo.getName(BuiltinOp) + "'");
-    else
-      Info.CCEDiag(E, diag::note_invalid_subexpr_in_const_expr);
-    LLVM_FALLTHROUGH;
-  case Builtin::BI__builtin_memcpy:
-  case Builtin::BI__builtin_memmove:
-  case Builtin::BI__builtin_wmemcpy:
-  case Builtin::BI__builtin_wmemmove: {
-    bool WChar = BuiltinOp == Builtin::BIwmemcpy ||
-                 BuiltinOp == Builtin::BIwmemmove ||
-                 BuiltinOp == Builtin::BI__builtin_wmemcpy ||
-                 BuiltinOp == Builtin::BI__builtin_wmemmove;
-    bool Move = BuiltinOp == Builtin::BImemmove ||
-                BuiltinOp == Builtin::BIwmemmove ||
-                BuiltinOp == Builtin::BI__builtin_memmove ||
-                BuiltinOp == Builtin::BI__builtin_wmemmove;
-
-    // The result of mem* is the first argument.
-    if (!Visit(E->getArg(0)))
-      return false;
-    LValue Dest = Result;
-
-    LValue Src;
-    if (!EvaluatePointer(E->getArg(1), Src, Info))
-      return false;
-
-    APSInt N;
-    if (!EvaluateInteger(E->getArg(2), N, Info))
-      return false;
-    assert(!N.isSigned() && "memcpy and friends take an unsigned size");
-
-    // If the size is zero, we treat this as always being a valid no-op.
-    // (Even if one of the src and dest pointers is null.)
-    if (!N)
-      return true;
-
-    // Otherwise, if either of the operands is null, we can't proceed. Don't
-    // try to determine the type of the copied objects, because there aren't
-    // any.
-    if (!Src.Base || !Dest.Base) {
-      APValue Val;
-      (!Src.Base ? Src : Dest).moveInto(Val);
-      Info.FFDiag(E, diag::note_constexpr_memcpy_null)
-          << Move << WChar << !!Src.Base
-          << Val.getAsString(Info.Ctx, E->getArg(0)->getType());
-      return false;
-    }
-    if (Src.Designator.Invalid || Dest.Designator.Invalid)
-      return false;
-
-    // We require that Src and Dest are both pointers to arrays of
-    // trivially-copyable type. (For the wide version, the designator will be
-    // invalid if the designated object is not a wchar_t.)
-    QualType T = Dest.Designator.getType(Info.Ctx);
-    QualType SrcT = Src.Designator.getType(Info.Ctx);
-    if (!Info.Ctx.hasSameUnqualifiedType(T, SrcT)) {
-      Info.FFDiag(E, diag::note_constexpr_memcpy_type_pun) << Move << SrcT << T;
-      return false;
-    }
-    if (T->isIncompleteType()) {
-      Info.FFDiag(E, diag::note_constexpr_memcpy_incomplete_type) << Move << T;
-      return false;
-    }
-    if (!T.isTriviallyCopyableType(Info.Ctx)) {
-      Info.FFDiag(E, diag::note_constexpr_memcpy_nontrivial) << Move << T;
-      return false;
-    }
-
-    // Figure out how many T's we're copying.
-    uint64_t TSize = Info.Ctx.getTypeSizeInChars(T).getQuantity();
-    if (!WChar) {
-      uint64_t Remainder;
-      llvm::APInt OrigN = N;
-      llvm::APInt::udivrem(OrigN, TSize, N, Remainder);
-      if (Remainder) {
-        Info.FFDiag(E, diag::note_constexpr_memcpy_unsupported)
-            << Move << WChar << 0 << T << OrigN.toString(10, /*Signed*/false)
-            << (unsigned)TSize;
-        return false;
-      }
-    }
-
-    // Check that the copying will remain within the arrays, just so that we
-    // can give a more meaningful diagnostic. This implicitly also checks that
-    // N fits into 64 bits.
-    uint64_t RemainingSrcSize = Src.Designator.validIndexAdjustments().second;
-    uint64_t RemainingDestSize = Dest.Designator.validIndexAdjustments().second;
-    if (N.ugt(RemainingSrcSize) || N.ugt(RemainingDestSize)) {
-      Info.FFDiag(E, diag::note_constexpr_memcpy_unsupported)
-          << Move << WChar << (N.ugt(RemainingSrcSize) ? 1 : 2) << T
-          << N.toString(10, /*Signed*/false);
-      return false;
-    }
-    uint64_t NElems = N.getZExtValue();
-    uint64_t NBytes = NElems * TSize;
-
-    // Check for overlap.
-    int Direction = 1;
-    if (HasSameBase(Src, Dest)) {
-      uint64_t SrcOffset = Src.getLValueOffset().getQuantity();
-      uint64_t DestOffset = Dest.getLValueOffset().getQuantity();
-      if (DestOffset >= SrcOffset && DestOffset - SrcOffset < NBytes) {
-        // Dest is inside the source region.
-        if (!Move) {
-          Info.FFDiag(E, diag::note_constexpr_memcpy_overlap) << WChar;
-          return false;
-        }
-        // For memmove and friends, copy backwards.
-        if (!HandleLValueArrayAdjustment(Info, E, Src, T, NElems - 1) ||
-            !HandleLValueArrayAdjustment(Info, E, Dest, T, NElems - 1))
-          return false;
-        Direction = -1;
-      } else if (!Move && SrcOffset >= DestOffset &&
-                 SrcOffset - DestOffset < NBytes) {
-        // Src is inside the destination region for memcpy: invalid.
-        Info.FFDiag(E, diag::note_constexpr_memcpy_overlap) << WChar;
-        return false;
-      }
-    }
-
-    while (true) {
-      APValue Val;
-      if (!handleLValueToRValueConversion(Info, E, T, Src, Val) ||
-          !handleAssignment(Info, E, Dest, T, Val))
-        return false;
-      // Do not iterate past the last element; if we're copying backwards, that
-      // might take us off the start of the array.
-      if (--NElems == 0)
-        return true;
-      if (!HandleLValueArrayAdjustment(Info, E, Src, T, Direction) ||
-          !HandleLValueArrayAdjustment(Info, E, Dest, T, Direction))
-        return false;
-    }
-  }
-
-  default:
-    return visitNonBuiltinCallExpr(E);
-  }
-}
-
-//===----------------------------------------------------------------------===//
-// Member Pointer Evaluation
-//===----------------------------------------------------------------------===//
-
-namespace {
-class MemberPointerExprEvaluator
-  : public ExprEvaluatorBase<MemberPointerExprEvaluator> {
-  MemberPtr &Result;
-
-  bool Success(const ValueDecl *D) {
-    Result = MemberPtr(D);
-    return true;
-  }
-public:
-
-  MemberPointerExprEvaluator(EvalInfo &Info, MemberPtr &Result)
-    : ExprEvaluatorBaseTy(Info), Result(Result) {}
-
-  bool Success(const APValue &V, const Expr *E) {
-    Result.setFrom(V);
-    return true;
-  }
-  bool ZeroInitialization(const Expr *E) {
-    return Success((const ValueDecl*)nullptr);
-  }
-
-  bool VisitCastExpr(const CastExpr *E);
-  bool VisitUnaryAddrOf(const UnaryOperator *E);
-};
-} // end anonymous namespace
-
-static bool EvaluateMemberPointer(const Expr *E, MemberPtr &Result,
-                                  EvalInfo &Info) {
-  assert(E->isRValue() && E->getType()->isMemberPointerType());
-  return MemberPointerExprEvaluator(Info, Result).Visit(E);
-}
-
-bool MemberPointerExprEvaluator::VisitCastExpr(const CastExpr *E) {
-  switch (E->getCastKind()) {
-  default:
-    return ExprEvaluatorBaseTy::VisitCastExpr(E);
-
-  case CK_NullToMemberPointer:
-    VisitIgnoredValue(E->getSubExpr());
-    return ZeroInitialization(E);
-
-  case CK_BaseToDerivedMemberPointer: {
-    if (!Visit(E->getSubExpr()))
-      return false;
-    if (E->path_empty())
-      return true;
-    // Base-to-derived member pointer casts store the path in derived-to-base
-    // order, so iterate backwards. The CXXBaseSpecifier also provides us with
-    // the wrong end of the derived->base arc, so stagger the path by one class.
-    typedef std::reverse_iterator<CastExpr::path_const_iterator> ReverseIter;
-    for (ReverseIter PathI(E->path_end() - 1), PathE(E->path_begin());
-         PathI != PathE; ++PathI) {
-      assert(!(*PathI)->isVirtual() && "memptr cast through vbase");
-      const CXXRecordDecl *Derived = (*PathI)->getType()->getAsCXXRecordDecl();
-      if (!Result.castToDerived(Derived))
-        return Error(E);
-    }
-    const Type *FinalTy = E->getType()->castAs<MemberPointerType>()->getClass();
-    if (!Result.castToDerived(FinalTy->getAsCXXRecordDecl()))
-      return Error(E);
-    return true;
-  }
-
-  case CK_DerivedToBaseMemberPointer:
-    if (!Visit(E->getSubExpr()))
-      return false;
-    for (CastExpr::path_const_iterator PathI = E->path_begin(),
-         PathE = E->path_end(); PathI != PathE; ++PathI) {
-      assert(!(*PathI)->isVirtual() && "memptr cast through vbase");
-      const CXXRecordDecl *Base = (*PathI)->getType()->getAsCXXRecordDecl();
-      if (!Result.castToBase(Base))
-        return Error(E);
-    }
-    return true;
-  }
-}
-
-bool MemberPointerExprEvaluator::VisitUnaryAddrOf(const UnaryOperator *E) {
-  // C++11 [expr.unary.op]p3 has very strict rules on how the address of a
-  // member can be formed.
-  return Success(cast<DeclRefExpr>(E->getSubExpr())->getDecl());
-}
-
-//===----------------------------------------------------------------------===//
-// Record Evaluation
-//===----------------------------------------------------------------------===//
-
-namespace {
-  class RecordExprEvaluator
-  : public ExprEvaluatorBase<RecordExprEvaluator> {
-    const LValue &This;
-    APValue &Result;
-  public:
-
-    RecordExprEvaluator(EvalInfo &info, const LValue &This, APValue &Result)
-      : ExprEvaluatorBaseTy(info), This(This), Result(Result) {}
-
-    bool Success(const APValue &V, const Expr *E) {
-      Result = V;
-      return true;
-    }
-    bool ZeroInitialization(const Expr *E) {
-      return ZeroInitialization(E, E->getType());
-    }
-    bool ZeroInitialization(const Expr *E, QualType T);
-
-    bool VisitCallExpr(const CallExpr *E) {
-      return handleCallExpr(E, Result, &This);
-    }
-    bool VisitCastExpr(const CastExpr *E);
-    bool VisitInitListExpr(const InitListExpr *E);
-    bool VisitCXXConstructExpr(const CXXConstructExpr *E) {
-      return VisitCXXConstructExpr(E, E->getType());
-    }
-    bool VisitLambdaExpr(const LambdaExpr *E);
-    bool VisitCXXInheritedCtorInitExpr(const CXXInheritedCtorInitExpr *E);
-    bool VisitCXXConstructExpr(const CXXConstructExpr *E, QualType T);
-    bool VisitCXXStdInitializerListExpr(const CXXStdInitializerListExpr *E);
-
-    bool VisitBinCmp(const BinaryOperator *E);
-  };
-}
-
-/// Perform zero-initialization on an object of non-union class type.
-/// C++11 [dcl.init]p5:
-///  To zero-initialize an object or reference of type T means:
-///    [...]
-///    -- if T is a (possibly cv-qualified) non-union class type,
-///       each non-static data member and each base-class subobject is
-///       zero-initialized
-static bool HandleClassZeroInitialization(EvalInfo &Info, const Expr *E,
-                                          const RecordDecl *RD,
-                                          const LValue &This, APValue &Result) {
-  assert(!RD->isUnion() && "Expected non-union class type");
-  const CXXRecordDecl *CD = dyn_cast<CXXRecordDecl>(RD);
-  Result = APValue(APValue::UninitStruct(), CD ? CD->getNumBases() : 0,
-                   std::distance(RD->field_begin(), RD->field_end()));
-
-  if (RD->isInvalidDecl()) return false;
-  const ASTRecordLayout &Layout = Info.Ctx.getASTRecordLayout(RD);
-
-  if (CD) {
-    unsigned Index = 0;
-    for (CXXRecordDecl::base_class_const_iterator I = CD->bases_begin(),
-           End = CD->bases_end(); I != End; ++I, ++Index) {
-      const CXXRecordDecl *Base = I->getType()->getAsCXXRecordDecl();
-      LValue Subobject = This;
-      if (!HandleLValueDirectBase(Info, E, Subobject, CD, Base, &Layout))
-        return false;
-      if (!HandleClassZeroInitialization(Info, E, Base, Subobject,
-                                         Result.getStructBase(Index)))
-        return false;
-    }
-  }
-
-  for (const auto *I : RD->fields()) {
-    // -- if T is a reference type, no initialization is performed.
-    if (I->getType()->isReferenceType())
-      continue;
-
-    LValue Subobject = This;
-    if (!HandleLValueMember(Info, E, Subobject, I, &Layout))
-      return false;
-
-    ImplicitValueInitExpr VIE(I->getType());
-    if (!EvaluateInPlace(
-          Result.getStructField(I->getFieldIndex()), Info, Subobject, &VIE))
-      return false;
-  }
-
-  return true;
-}
-
-bool RecordExprEvaluator::ZeroInitialization(const Expr *E, QualType T) {
-  const RecordDecl *RD = T->castAs<RecordType>()->getDecl();
-  if (RD->isInvalidDecl()) return false;
-  if (RD->isUnion()) {
-    // C++11 [dcl.init]p5: If T is a (possibly cv-qualified) union type, the
-    // object's first non-static named data member is zero-initialized
-    RecordDecl::field_iterator I = RD->field_begin();
-    if (I == RD->field_end()) {
-      Result = APValue((const FieldDecl*)nullptr);
-      return true;
-    }
-
-    LValue Subobject = This;
-    if (!HandleLValueMember(Info, E, Subobject, *I))
-      return false;
-    Result = APValue(*I);
-    ImplicitValueInitExpr VIE(I->getType());
-    return EvaluateInPlace(Result.getUnionValue(), Info, Subobject, &VIE);
-  }
-
-  if (isa<CXXRecordDecl>(RD) && cast<CXXRecordDecl>(RD)->getNumVBases()) {
-    Info.FFDiag(E, diag::note_constexpr_virtual_base) << RD;
-    return false;
-  }
-
-  return HandleClassZeroInitialization(Info, E, RD, This, Result);
-}
-
-bool RecordExprEvaluator::VisitCastExpr(const CastExpr *E) {
-  switch (E->getCastKind()) {
-  default:
-    return ExprEvaluatorBaseTy::VisitCastExpr(E);
-
-  case CK_ConstructorConversion:
-    return Visit(E->getSubExpr());
-
-  case CK_DerivedToBase:
-  case CK_UncheckedDerivedToBase: {
-    APValue DerivedObject;
-    if (!Evaluate(DerivedObject, Info, E->getSubExpr()))
-      return false;
-    if (!DerivedObject.isStruct())
-      return Error(E->getSubExpr());
-
-    // Derived-to-base rvalue conversion: just slice off the derived part.
-    APValue *Value = &DerivedObject;
-    const CXXRecordDecl *RD = E->getSubExpr()->getType()->getAsCXXRecordDecl();
-    for (CastExpr::path_const_iterator PathI = E->path_begin(),
-         PathE = E->path_end(); PathI != PathE; ++PathI) {
-      assert(!(*PathI)->isVirtual() && "record rvalue with virtual base");
-      const CXXRecordDecl *Base = (*PathI)->getType()->getAsCXXRecordDecl();
-      Value = &Value->getStructBase(getBaseIndex(RD, Base));
-      RD = Base;
-    }
-    Result = *Value;
-    return true;
-  }
-  }
-}
-
-bool RecordExprEvaluator::VisitInitListExpr(const InitListExpr *E) {
-  if (E->isTransparent())
-    return Visit(E->getInit(0));
-
-  const RecordDecl *RD = E->getType()->castAs<RecordType>()->getDecl();
-  if (RD->isInvalidDecl()) return false;
-  const ASTRecordLayout &Layout = Info.Ctx.getASTRecordLayout(RD);
-
-  if (RD->isUnion()) {
-    const FieldDecl *Field = E->getInitializedFieldInUnion();
-    Result = APValue(Field);
-    if (!Field)
-      return true;
-
-    // If the initializer list for a union does not contain any elements, the
-    // first element of the union is value-initialized.
-    // FIXME: The element should be initialized from an initializer list.
-    //        Is this difference ever observable for initializer lists which
-    //        we don't build?
-    ImplicitValueInitExpr VIE(Field->getType());
-    const Expr *InitExpr = E->getNumInits() ? E->getInit(0) : &VIE;
-
-    LValue Subobject = This;
-    if (!HandleLValueMember(Info, InitExpr, Subobject, Field, &Layout))
-      return false;
-
-    // Temporarily override This, in case there's a CXXDefaultInitExpr in here.
-    ThisOverrideRAII ThisOverride(*Info.CurrentCall, &This,
-                                  isa<CXXDefaultInitExpr>(InitExpr));
-
-    return EvaluateInPlace(Result.getUnionValue(), Info, Subobject, InitExpr);
-  }
-
-  auto *CXXRD = dyn_cast<CXXRecordDecl>(RD);
-  if (Result.isUninit())
-    Result = APValue(APValue::UninitStruct(), CXXRD ? CXXRD->getNumBases() : 0,
-                     std::distance(RD->field_begin(), RD->field_end()));
-  unsigned ElementNo = 0;
-  bool Success = true;
-
-  // Initialize base classes.
-  if (CXXRD) {
-    for (const auto &Base : CXXRD->bases()) {
-      assert(ElementNo < E->getNumInits() && "missing init for base class");
-      const Expr *Init = E->getInit(ElementNo);
-
-      LValue Subobject = This;
-      if (!HandleLValueBase(Info, Init, Subobject, CXXRD, &Base))
-        return false;
-
-      APValue &FieldVal = Result.getStructBase(ElementNo);
-      if (!EvaluateInPlace(FieldVal, Info, Subobject, Init)) {
-        if (!Info.noteFailure())
-          return false;
-        Success = false;
-      }
-      ++ElementNo;
-    }
-  }
-
-  // Initialize members.
-  for (const auto *Field : RD->fields()) {
-    // Anonymous bit-fields are not considered members of the class for
-    // purposes of aggregate initialization.
-    if (Field->isUnnamedBitfield())
-      continue;
-
-    LValue Subobject = This;
-
-    bool HaveInit = ElementNo < E->getNumInits();
-
-    // FIXME: Diagnostics here should point to the end of the initializer
-    // list, not the start.
-    if (!HandleLValueMember(Info, HaveInit ? E->getInit(ElementNo) : E,
-                            Subobject, Field, &Layout))
-      return false;
-
-    // Perform an implicit value-initialization for members beyond the end of
-    // the initializer list.
-    ImplicitValueInitExpr VIE(HaveInit ? Info.Ctx.IntTy : Field->getType());
-    const Expr *Init = HaveInit ? E->getInit(ElementNo++) : &VIE;
-
-    // Temporarily override This, in case there's a CXXDefaultInitExpr in here.
-    ThisOverrideRAII ThisOverride(*Info.CurrentCall, &This,
-                                  isa<CXXDefaultInitExpr>(Init));
-
-    APValue &FieldVal = Result.getStructField(Field->getFieldIndex());
-    if (!EvaluateInPlace(FieldVal, Info, Subobject, Init) ||
-        (Field->isBitField() && !truncateBitfieldValue(Info, Init,
-                                                       FieldVal, Field))) {
-      if (!Info.noteFailure())
-        return false;
-      Success = false;
-    }
-  }
-
-  return Success;
-}
-
-bool RecordExprEvaluator::VisitCXXConstructExpr(const CXXConstructExpr *E,
-                                                QualType T) {
-  // Note that E's type is not necessarily the type of our class here; we might
-  // be initializing an array element instead.
-  const CXXConstructorDecl *FD = E->getConstructor();
-  if (FD->isInvalidDecl() || FD->getParent()->isInvalidDecl()) return false;
-
-  bool ZeroInit = E->requiresZeroInitialization();
-  if (CheckTrivialDefaultConstructor(Info, E->getExprLoc(), FD, ZeroInit)) {
-    // If we've already performed zero-initialization, we're already done.
-    if (!Result.isUninit())
-      return true;
-
-    // We can get here in two different ways:
-    //  1) We're performing value-initialization, and should zero-initialize
-    //     the object, or
-    //  2) We're performing default-initialization of an object with a trivial
-    //     constexpr default constructor, in which case we should start the
-    //     lifetimes of all the base subobjects (there can be no data member
-    //     subobjects in this case) per [basic.life]p1.
-    // Either way, ZeroInitialization is appropriate.
-    return ZeroInitialization(E, T);
-  }
-
-  const FunctionDecl *Definition = nullptr;
-  auto Body = FD->getBody(Definition);
-
-  if (!CheckConstexprFunction(Info, E->getExprLoc(), FD, Definition, Body))
-    return false;
-
-  // Avoid materializing a temporary for an elidable copy/move constructor.
-  if (E->isElidable() && !ZeroInit)
-    if (const MaterializeTemporaryExpr *ME
-          = dyn_cast<MaterializeTemporaryExpr>(E->getArg(0)))
-      return Visit(ME->GetTemporaryExpr());
-
-  if (ZeroInit && !ZeroInitialization(E, T))
-    return false;
-
-  auto Args = llvm::makeArrayRef(E->getArgs(), E->getNumArgs());
-  return HandleConstructorCall(E, This, Args,
-                               cast<CXXConstructorDecl>(Definition), Info,
-                               Result);
-}
-
-bool RecordExprEvaluator::VisitCXXInheritedCtorInitExpr(
-    const CXXInheritedCtorInitExpr *E) {
-  if (!Info.CurrentCall) {
-    assert(Info.checkingPotentialConstantExpression());
-    return false;
-  }
-
-  const CXXConstructorDecl *FD = E->getConstructor();
-  if (FD->isInvalidDecl() || FD->getParent()->isInvalidDecl())
-    return false;
-
-  const FunctionDecl *Definition = nullptr;
-  auto Body = FD->getBody(Definition);
-
-  if (!CheckConstexprFunction(Info, E->getExprLoc(), FD, Definition, Body))
-    return false;
-
-  return HandleConstructorCall(E, This, Info.CurrentCall->Arguments,
-                               cast<CXXConstructorDecl>(Definition), Info,
-                               Result);
-}
-
-bool RecordExprEvaluator::VisitCXXStdInitializerListExpr(
-    const CXXStdInitializerListExpr *E) {
-  const ConstantArrayType *ArrayType =
-      Info.Ctx.getAsConstantArrayType(E->getSubExpr()->getType());
-
-  LValue Array;
-  if (!EvaluateLValue(E->getSubExpr(), Array, Info))
-    return false;
-
-  // Get a pointer to the first element of the array.
-  Array.addArray(Info, E, ArrayType);
-
-  // FIXME: Perform the checks on the field types in SemaInit.
-  RecordDecl *Record = E->getType()->castAs<RecordType>()->getDecl();
-  RecordDecl::field_iterator Field = Record->field_begin();
-  if (Field == Record->field_end())
-    return Error(E);
-
-  // Start pointer.
-  if (!Field->getType()->isPointerType() ||
-      !Info.Ctx.hasSameType(Field->getType()->getPointeeType(),
-                            ArrayType->getElementType()))
-    return Error(E);
-
-  // FIXME: What if the initializer_list type has base classes, etc?
-  Result = APValue(APValue::UninitStruct(), 0, 2);
-  Array.moveInto(Result.getStructField(0));
-
-  if (++Field == Record->field_end())
-    return Error(E);
-
-  if (Field->getType()->isPointerType() &&
-      Info.Ctx.hasSameType(Field->getType()->getPointeeType(),
-                           ArrayType->getElementType())) {
-    // End pointer.
-    if (!HandleLValueArrayAdjustment(Info, E, Array,
-                                     ArrayType->getElementType(),
-                                     ArrayType->getSize().getZExtValue()))
-      return false;
-    Array.moveInto(Result.getStructField(1));
-  } else if (Info.Ctx.hasSameType(Field->getType(), Info.Ctx.getSizeType()))
-    // Length.
-    Result.getStructField(1) = APValue(APSInt(ArrayType->getSize()));
-  else
-    return Error(E);
-
-  if (++Field != Record->field_end())
-    return Error(E);
-
-  return true;
-}
-
-bool RecordExprEvaluator::VisitLambdaExpr(const LambdaExpr *E) {
-  const CXXRecordDecl *ClosureClass = E->getLambdaClass();
-  if (ClosureClass->isInvalidDecl()) return false;
-
-  if (Info.checkingPotentialConstantExpression()) return true;
-
-  const size_t NumFields =
-      std::distance(ClosureClass->field_begin(), ClosureClass->field_end());
-
-  assert(NumFields == (size_t)std::distance(E->capture_init_begin(),
-                                            E->capture_init_end()) &&
-         "The number of lambda capture initializers should equal the number of "
-         "fields within the closure type");
-
-  Result = APValue(APValue::UninitStruct(), /*NumBases*/0, NumFields);
-  // Iterate through all the lambda's closure object's fields and initialize
-  // them.
-  auto *CaptureInitIt = E->capture_init_begin();
-  const LambdaCapture *CaptureIt = ClosureClass->captures_begin();
-  bool Success = true;
-  for (const auto *Field : ClosureClass->fields()) {
-    assert(CaptureInitIt != E->capture_init_end());
-    // Get the initializer for this field
-    Expr *const CurFieldInit = *CaptureInitIt++;
-
-    // If there is no initializer, either this is a VLA or an error has
-    // occurred.
-    if (!CurFieldInit)
-      return Error(E);
-
-    APValue &FieldVal = Result.getStructField(Field->getFieldIndex());
-    if (!EvaluateInPlace(FieldVal, Info, This, CurFieldInit)) {
-      if (!Info.keepEvaluatingAfterFailure())
-        return false;
-      Success = false;
-    }
-    ++CaptureIt;
-  }
-  return Success;
-}
-
-static bool EvaluateRecord(const Expr *E, const LValue &This,
-                           APValue &Result, EvalInfo &Info) {
-  assert(E->isRValue() && E->getType()->isRecordType() &&
-         "can't evaluate expression as a record rvalue");
-  return RecordExprEvaluator(Info, This, Result).Visit(E);
-}
-
-//===----------------------------------------------------------------------===//
-// Temporary Evaluation
-//
-// Temporaries are represented in the AST as rvalues, but generally behave like
-// lvalues. The full-object of which the temporary is a subobject is implicitly
-// materialized so that a reference can bind to it.
-//===----------------------------------------------------------------------===//
-namespace {
-class TemporaryExprEvaluator
-  : public LValueExprEvaluatorBase<TemporaryExprEvaluator> {
-public:
-  TemporaryExprEvaluator(EvalInfo &Info, LValue &Result) :
-    LValueExprEvaluatorBaseTy(Info, Result, false) {}
-
-  /// Visit an expression which constructs the value of this temporary.
-  bool VisitConstructExpr(const Expr *E) {
-    APValue &Value = createTemporary(E, false, Result, *Info.CurrentCall);
-    return EvaluateInPlace(Value, Info, Result, E);
-  }
-
-  bool VisitCastExpr(const CastExpr *E) {
-    switch (E->getCastKind()) {
-    default:
-      return LValueExprEvaluatorBaseTy::VisitCastExpr(E);
-
-    case CK_ConstructorConversion:
-      return VisitConstructExpr(E->getSubExpr());
-    }
-  }
-  bool VisitInitListExpr(const InitListExpr *E) {
-    return VisitConstructExpr(E);
-  }
-  bool VisitCXXConstructExpr(const CXXConstructExpr *E) {
-    return VisitConstructExpr(E);
-  }
-  bool VisitCallExpr(const CallExpr *E) {
-    return VisitConstructExpr(E);
-  }
-  bool VisitCXXStdInitializerListExpr(const CXXStdInitializerListExpr *E) {
-    return VisitConstructExpr(E);
-  }
-  bool VisitLambdaExpr(const LambdaExpr *E) {
-    return VisitConstructExpr(E);
-  }
-};
-} // end anonymous namespace
-
-/// Evaluate an expression of record type as a temporary.
-static bool EvaluateTemporary(const Expr *E, LValue &Result, EvalInfo &Info) {
-  assert(E->isRValue() && E->getType()->isRecordType());
-  return TemporaryExprEvaluator(Info, Result).Visit(E);
-}
-
-//===----------------------------------------------------------------------===//
-// Vector Evaluation
-//===----------------------------------------------------------------------===//
-
-namespace {
-  class VectorExprEvaluator
-  : public ExprEvaluatorBase<VectorExprEvaluator> {
-    APValue &Result;
-  public:
-
-    VectorExprEvaluator(EvalInfo &info, APValue &Result)
-      : ExprEvaluatorBaseTy(info), Result(Result) {}
-
-    bool Success(ArrayRef<APValue> V, const Expr *E) {
-      assert(V.size() == E->getType()->castAs<VectorType>()->getNumElements());
-      // FIXME: remove this APValue copy.
-      Result = APValue(V.data(), V.size());
-      return true;
-    }
-    bool Success(const APValue &V, const Expr *E) {
-      assert(V.isVector());
-      Result = V;
-      return true;
-    }
-    bool ZeroInitialization(const Expr *E);
-
-    bool VisitUnaryReal(const UnaryOperator *E)
-      { return Visit(E->getSubExpr()); }
-    bool VisitCastExpr(const CastExpr* E);
-    bool VisitInitListExpr(const InitListExpr *E);
-    bool VisitUnaryImag(const UnaryOperator *E);
-    // FIXME: Missing: unary -, unary ~, binary add/sub/mul/div,
-    //                 binary comparisons, binary and/or/xor,
-    //                 shufflevector, ExtVectorElementExpr
-  };
-} // end anonymous namespace
-
-static bool EvaluateVector(const Expr* E, APValue& Result, EvalInfo &Info) {
-  assert(E->isRValue() && E->getType()->isVectorType() &&"not a vector rvalue");
-  return VectorExprEvaluator(Info, Result).Visit(E);
-}
-
-bool VectorExprEvaluator::VisitCastExpr(const CastExpr *E) {
-  const VectorType *VTy = E->getType()->castAs<VectorType>();
-  unsigned NElts = VTy->getNumElements();
-
-  const Expr *SE = E->getSubExpr();
-  QualType SETy = SE->getType();
-
-  switch (E->getCastKind()) {
-  case CK_VectorSplat: {
-    APValue Val = APValue();
-    if (SETy->isIntegerType()) {
-      APSInt IntResult;
-      if (!EvaluateInteger(SE, IntResult, Info))
-        return false;
-      Val = APValue(std::move(IntResult));
-    } else if (SETy->isRealFloatingType()) {
-      APFloat FloatResult(0.0);
-      if (!EvaluateFloat(SE, FloatResult, Info))
-        return false;
-      Val = APValue(std::move(FloatResult));
-    } else {
-      return Error(E);
-    }
-
-    // Splat and create vector APValue.
-    SmallVector<APValue, 4> Elts(NElts, Val);
-    return Success(Elts, E);
-  }
-  case CK_BitCast: {
-    // Evaluate the operand into an APInt we can extract from.
-    llvm::APInt SValInt;
-    if (!EvalAndBitcastToAPInt(Info, SE, SValInt))
-      return false;
-    // Extract the elements
-    QualType EltTy = VTy->getElementType();
-    unsigned EltSize = Info.Ctx.getTypeSize(EltTy);
-    bool BigEndian = Info.Ctx.getTargetInfo().isBigEndian();
-    SmallVector<APValue, 4> Elts;
-    if (EltTy->isRealFloatingType()) {
-      const llvm::fltSemantics &Sem = Info.Ctx.getFloatTypeSemantics(EltTy);
-      unsigned FloatEltSize = EltSize;
-      if (&Sem == &APFloat::x87DoubleExtended())
-        FloatEltSize = 80;
-      for (unsigned i = 0; i < NElts; i++) {
-        llvm::APInt Elt;
-        if (BigEndian)
-          Elt = SValInt.rotl(i*EltSize+FloatEltSize).trunc(FloatEltSize);
-        else
-          Elt = SValInt.rotr(i*EltSize).trunc(FloatEltSize);
-        Elts.push_back(APValue(APFloat(Sem, Elt)));
-      }
-    } else if (EltTy->isIntegerType()) {
-      for (unsigned i = 0; i < NElts; i++) {
-        llvm::APInt Elt;
-        if (BigEndian)
-          Elt = SValInt.rotl(i*EltSize+EltSize).zextOrTrunc(EltSize);
-        else
-          Elt = SValInt.rotr(i*EltSize).zextOrTrunc(EltSize);
-        Elts.push_back(APValue(APSInt(Elt, EltTy->isSignedIntegerType())));
-      }
-    } else {
-      return Error(E);
-    }
-    return Success(Elts, E);
-  }
-  default:
-    return ExprEvaluatorBaseTy::VisitCastExpr(E);
-  }
-}
-
-bool
-VectorExprEvaluator::VisitInitListExpr(const InitListExpr *E) {
-  const VectorType *VT = E->getType()->castAs<VectorType>();
-  unsigned NumInits = E->getNumInits();
-  unsigned NumElements = VT->getNumElements();
-
-  QualType EltTy = VT->getElementType();
-  SmallVector<APValue, 4> Elements;
-
-  // The number of initializers can be less than the number of
-  // vector elements. For OpenCL, this can be due to nested vector
-  // initialization. For GCC compatibility, missing trailing elements
-  // should be initialized with zeroes.
-  unsigned CountInits = 0, CountElts = 0;
-  while (CountElts < NumElements) {
-    // Handle nested vector initialization.
-    if (CountInits < NumInits
-        && E->getInit(CountInits)->getType()->isVectorType()) {
-      APValue v;
-      if (!EvaluateVector(E->getInit(CountInits), v, Info))
-        return Error(E);
-      unsigned vlen = v.getVectorLength();
-      for (unsigned j = 0; j < vlen; j++)
-        Elements.push_back(v.getVectorElt(j));
-      CountElts += vlen;
-    } else if (EltTy->isIntegerType()) {
-      llvm::APSInt sInt(32);
-      if (CountInits < NumInits) {
-        if (!EvaluateInteger(E->getInit(CountInits), sInt, Info))
-          return false;
-      } else // trailing integer zero.
-        sInt = Info.Ctx.MakeIntValue(0, EltTy);
-      Elements.push_back(APValue(sInt));
-      CountElts++;
-    } else {
-      llvm::APFloat f(0.0);
-      if (CountInits < NumInits) {
-        if (!EvaluateFloat(E->getInit(CountInits), f, Info))
-          return false;
-      } else // trailing float zero.
-        f = APFloat::getZero(Info.Ctx.getFloatTypeSemantics(EltTy));
-      Elements.push_back(APValue(f));
-      CountElts++;
-    }
-    CountInits++;
-  }
-  return Success(Elements, E);
-}
-
-bool
-VectorExprEvaluator::ZeroInitialization(const Expr *E) {
-  const VectorType *VT = E->getType()->getAs<VectorType>();
-  QualType EltTy = VT->getElementType();
-  APValue ZeroElement;
-  if (EltTy->isIntegerType())
-    ZeroElement = APValue(Info.Ctx.MakeIntValue(0, EltTy));
-  else
-    ZeroElement =
-        APValue(APFloat::getZero(Info.Ctx.getFloatTypeSemantics(EltTy)));
-
-  SmallVector<APValue, 4> Elements(VT->getNumElements(), ZeroElement);
-  return Success(Elements, E);
-}
-
-bool VectorExprEvaluator::VisitUnaryImag(const UnaryOperator *E) {
-  VisitIgnoredValue(E->getSubExpr());
-  return ZeroInitialization(E);
-}
-
-//===----------------------------------------------------------------------===//
-// Array Evaluation
-//===----------------------------------------------------------------------===//
-
-namespace {
-  class ArrayExprEvaluator
-  : public ExprEvaluatorBase<ArrayExprEvaluator> {
-    const LValue &This;
-    APValue &Result;
-  public:
-
-    ArrayExprEvaluator(EvalInfo &Info, const LValue &This, APValue &Result)
-      : ExprEvaluatorBaseTy(Info), This(This), Result(Result) {}
-
-    bool Success(const APValue &V, const Expr *E) {
-      assert((V.isArray() || V.isLValue()) &&
-             "expected array or string literal");
-      Result = V;
-      return true;
-    }
-
-    bool ZeroInitialization(const Expr *E) {
-      const ConstantArrayType *CAT =
-          Info.Ctx.getAsConstantArrayType(E->getType());
-      if (!CAT)
-        return Error(E);
-
-      Result = APValue(APValue::UninitArray(), 0,
-                       CAT->getSize().getZExtValue());
-      if (!Result.hasArrayFiller()) return true;
-
-      // Zero-initialize all elements.
-      LValue Subobject = This;
-      Subobject.addArray(Info, E, CAT);
-      ImplicitValueInitExpr VIE(CAT->getElementType());
-      return EvaluateInPlace(Result.getArrayFiller(), Info, Subobject, &VIE);
-    }
-
-    bool VisitCallExpr(const CallExpr *E) {
-      return handleCallExpr(E, Result, &This);
-    }
-    bool VisitInitListExpr(const InitListExpr *E);
-    bool VisitArrayInitLoopExpr(const ArrayInitLoopExpr *E);
-    bool VisitCXXConstructExpr(const CXXConstructExpr *E);
-    bool VisitCXXConstructExpr(const CXXConstructExpr *E,
-                               const LValue &Subobject,
-                               APValue *Value, QualType Type);
-  };
-} // end anonymous namespace
-
-static bool EvaluateArray(const Expr *E, const LValue &This,
-                          APValue &Result, EvalInfo &Info) {
-  assert(E->isRValue() && E->getType()->isArrayType() && "not an array rvalue");
-  return ArrayExprEvaluator(Info, This, Result).Visit(E);
-}
-
-// Return true iff the given array filler may depend on the element index.
-static bool MaybeElementDependentArrayFiller(const Expr *FillerExpr) {
-  // For now, just whitelist non-class value-initialization and initialization
-  // lists comprised of them.
-  if (isa<ImplicitValueInitExpr>(FillerExpr))
-    return false;
-  if (const InitListExpr *ILE = dyn_cast<InitListExpr>(FillerExpr)) {
-    for (unsigned I = 0, E = ILE->getNumInits(); I != E; ++I) {
-      if (MaybeElementDependentArrayFiller(ILE->getInit(I)))
-        return true;
-    }
-    return false;
-  }
-  return true;
-}
-
-bool ArrayExprEvaluator::VisitInitListExpr(const InitListExpr *E) {
-  const ConstantArrayType *CAT = Info.Ctx.getAsConstantArrayType(E->getType());
-  if (!CAT)
-    return Error(E);
-
-  // C++11 [dcl.init.string]p1: A char array [...] can be initialized by [...]
-  // an appropriately-typed string literal enclosed in braces.
-  if (E->isStringLiteralInit()) {
-    LValue LV;
-    if (!EvaluateLValue(E->getInit(0), LV, Info))
-      return false;
-    APValue Val;
-    LV.moveInto(Val);
-    return Success(Val, E);
-  }
-
-  bool Success = true;
-
-  assert((!Result.isArray() || Result.getArrayInitializedElts() == 0) &&
-         "zero-initialized array shouldn't have any initialized elts");
-  APValue Filler;
-  if (Result.isArray() && Result.hasArrayFiller())
-    Filler = Result.getArrayFiller();
-
-  unsigned NumEltsToInit = E->getNumInits();
-  unsigned NumElts = CAT->getSize().getZExtValue();
-  const Expr *FillerExpr = E->hasArrayFiller() ? E->getArrayFiller() : nullptr;
-
-  // If the initializer might depend on the array index, run it for each
-  // array element.
-  if (NumEltsToInit != NumElts && MaybeElementDependentArrayFiller(FillerExpr))
-    NumEltsToInit = NumElts;
-
-  LLVM_DEBUG(llvm::dbgs() << "The number of elements to initialize: "
-                          << NumEltsToInit << ".\n");
-
-  Result = APValue(APValue::UninitArray(), NumEltsToInit, NumElts);
-
-  // If the array was previously zero-initialized, preserve the
-  // zero-initialized values.
-  if (!Filler.isUninit()) {
-    for (unsigned I = 0, E = Result.getArrayInitializedElts(); I != E; ++I)
-      Result.getArrayInitializedElt(I) = Filler;
-    if (Result.hasArrayFiller())
-      Result.getArrayFiller() = Filler;
-  }
-
-  LValue Subobject = This;
-  Subobject.addArray(Info, E, CAT);
-  for (unsigned Index = 0; Index != NumEltsToInit; ++Index) {
-    const Expr *Init =
-        Index < E->getNumInits() ? E->getInit(Index) : FillerExpr;
-    if (!EvaluateInPlace(Result.getArrayInitializedElt(Index),
-                         Info, Subobject, Init) ||
-        !HandleLValueArrayAdjustment(Info, Init, Subobject,
-                                     CAT->getElementType(), 1)) {
-      if (!Info.noteFailure())
-        return false;
-      Success = false;
-    }
-  }
-
-  if (!Result.hasArrayFiller())
-    return Success;
-
-  // If we get here, we have a trivial filler, which we can just evaluate
-  // once and splat over the rest of the array elements.
-  assert(FillerExpr && "no array filler for incomplete init list");
-  return EvaluateInPlace(Result.getArrayFiller(), Info, Subobject,
-                         FillerExpr) && Success;
-}
-
-bool ArrayExprEvaluator::VisitArrayInitLoopExpr(const ArrayInitLoopExpr *E) {
-  if (E->getCommonExpr() &&
-      !Evaluate(Info.CurrentCall->createTemporary(E->getCommonExpr(), false),
-                Info, E->getCommonExpr()->getSourceExpr()))
-    return false;
-
-  auto *CAT = cast<ConstantArrayType>(E->getType()->castAsArrayTypeUnsafe());
-
-  uint64_t Elements = CAT->getSize().getZExtValue();
-  Result = APValue(APValue::UninitArray(), Elements, Elements);
-
-  LValue Subobject = This;
-  Subobject.addArray(Info, E, CAT);
-
-  bool Success = true;
-  for (EvalInfo::ArrayInitLoopIndex Index(Info); Index != Elements; ++Index) {
-    if (!EvaluateInPlace(Result.getArrayInitializedElt(Index),
-                         Info, Subobject, E->getSubExpr()) ||
-        !HandleLValueArrayAdjustment(Info, E, Subobject,
-                                     CAT->getElementType(), 1)) {
-      if (!Info.noteFailure())
-        return false;
-      Success = false;
-    }
-  }
-
-  return Success;
-}
-
-bool ArrayExprEvaluator::VisitCXXConstructExpr(const CXXConstructExpr *E) {
-  return VisitCXXConstructExpr(E, This, &Result, E->getType());
-}
-
-bool ArrayExprEvaluator::VisitCXXConstructExpr(const CXXConstructExpr *E,
-                                               const LValue &Subobject,
-                                               APValue *Value,
-                                               QualType Type) {
-  bool HadZeroInit = !Value->isUninit();
-
-  if (const ConstantArrayType *CAT = Info.Ctx.getAsConstantArrayType(Type)) {
-    unsigned N = CAT->getSize().getZExtValue();
-
-    // Preserve the array filler if we had prior zero-initialization.
-    APValue Filler =
-      HadZeroInit && Value->hasArrayFiller() ? Value->getArrayFiller()
-                                             : APValue();
-
-    *Value = APValue(APValue::UninitArray(), N, N);
-
-    if (HadZeroInit)
-      for (unsigned I = 0; I != N; ++I)
-        Value->getArrayInitializedElt(I) = Filler;
-
-    // Initialize the elements.
-    LValue ArrayElt = Subobject;
-    ArrayElt.addArray(Info, E, CAT);
-    for (unsigned I = 0; I != N; ++I)
-      if (!VisitCXXConstructExpr(E, ArrayElt, &Value->getArrayInitializedElt(I),
-                                 CAT->getElementType()) ||
-          !HandleLValueArrayAdjustment(Info, E, ArrayElt,
-                                       CAT->getElementType(), 1))
-        return false;
-
-    return true;
-  }
-
-  if (!Type->isRecordType())
-    return Error(E);
-
-  return RecordExprEvaluator(Info, Subobject, *Value)
-             .VisitCXXConstructExpr(E, Type);
-}
-
-//===----------------------------------------------------------------------===//
-// Integer Evaluation
-//
-// As a GNU extension, we support casting pointers to sufficiently-wide integer
-// types and back in constant folding. Integer values are thus represented
-// either as an integer-valued APValue, or as an lvalue-valued APValue.
-//===----------------------------------------------------------------------===//
-
-namespace {
-class IntExprEvaluator
-        : public ExprEvaluatorBase<IntExprEvaluator> {
-  APValue &Result;
-public:
-  IntExprEvaluator(EvalInfo &info, APValue &result)
-      : ExprEvaluatorBaseTy(info), Result(result) {}
-
-  bool Success(const llvm::APSInt &SI, const Expr *E, APValue &Result) {
-    assert(E->getType()->isIntegralOrEnumerationType() &&
-           "Invalid evaluation result.");
-    assert(SI.isSigned() == E->getType()->isSignedIntegerOrEnumerationType() &&
-           "Invalid evaluation result.");
-    assert(SI.getBitWidth() == Info.Ctx.getIntWidth(E->getType()) &&
-           "Invalid evaluation result.");
-    Result = APValue(SI);
-    return true;
-  }
-  bool Success(const llvm::APSInt &SI, const Expr *E) {
-    return Success(SI, E, Result);
-  }
-
-  bool Success(const llvm::APInt &I, const Expr *E, APValue &Result) {
-    assert(E->getType()->isIntegralOrEnumerationType() &&
-           "Invalid evaluation result.");
-    assert(I.getBitWidth() == Info.Ctx.getIntWidth(E->getType()) &&
-           "Invalid evaluation result.");
-    Result = APValue(APSInt(I));
-    Result.getInt().setIsUnsigned(
-                            E->getType()->isUnsignedIntegerOrEnumerationType());
-    return true;
-  }
-  bool Success(const llvm::APInt &I, const Expr *E) {
-    return Success(I, E, Result);
-  }
-
-  bool Success(uint64_t Value, const Expr *E, APValue &Result) {
-    assert(E->getType()->isIntegralOrEnumerationType() &&
-           "Invalid evaluation result.");
-    Result = APValue(Info.Ctx.MakeIntValue(Value, E->getType()));
-    return true;
-  }
-  bool Success(uint64_t Value, const Expr *E) {
-    return Success(Value, E, Result);
-  }
-
-  bool Success(CharUnits Size, const Expr *E) {
-    return Success(Size.getQuantity(), E);
-  }
-
-  bool Success(const APValue &V, const Expr *E) {
-    if (V.isLValue() || V.isAddrLabelDiff()) {
-      Result = V;
-      return true;
-    }
-    return Success(V.getInt(), E);
-  }
-
-  bool ZeroInitialization(const Expr *E) { return Success(0, E); }
-
-  //===--------------------------------------------------------------------===//
-  //                            Visitor Methods
-  //===--------------------------------------------------------------------===//
-
-  bool VisitConstantExpr(const ConstantExpr *E);
-
-  bool VisitIntegerLiteral(const IntegerLiteral *E) {
-    return Success(E->getValue(), E);
-  }
-  bool VisitCharacterLiteral(const CharacterLiteral *E) {
-    return Success(E->getValue(), E);
-  }
-
-  bool CheckReferencedDecl(const Expr *E, const Decl *D);
-  bool VisitDeclRefExpr(const DeclRefExpr *E) {
-    if (CheckReferencedDecl(E, E->getDecl()))
-      return true;
-
-    return ExprEvaluatorBaseTy::VisitDeclRefExpr(E);
-  }
-  bool VisitMemberExpr(const MemberExpr *E) {
-    if (CheckReferencedDecl(E, E->getMemberDecl())) {
-      VisitIgnoredBaseExpression(E->getBase());
-      return true;
-    }
-
-    return ExprEvaluatorBaseTy::VisitMemberExpr(E);
-  }
-
-  bool VisitCallExpr(const CallExpr *E);
-  bool VisitBuiltinCallExpr(const CallExpr *E, unsigned BuiltinOp);
-  bool VisitBinaryOperator(const BinaryOperator *E);
-  bool VisitOffsetOfExpr(const OffsetOfExpr *E);
-  bool VisitUnaryOperator(const UnaryOperator *E);
-
-  bool VisitCastExpr(const CastExpr* E);
-  bool VisitUnaryExprOrTypeTraitExpr(const UnaryExprOrTypeTraitExpr *E);
-
-  bool VisitCXXBoolLiteralExpr(const CXXBoolLiteralExpr *E) {
-    return Success(E->getValue(), E);
-  }
-
-  bool VisitObjCBoolLiteralExpr(const ObjCBoolLiteralExpr *E) {
-    return Success(E->getValue(), E);
-  }
-
-  bool VisitArrayInitIndexExpr(const ArrayInitIndexExpr *E) {
-    if (Info.ArrayInitIndex == uint64_t(-1)) {
-      // We were asked to evaluate this subexpression independent of the
-      // enclosing ArrayInitLoopExpr. We can't do that.
-      Info.FFDiag(E);
-      return false;
-    }
-    return Success(Info.ArrayInitIndex, E);
-  }
-
-  // Note, GNU defines __null as an integer, not a pointer.
-  bool VisitGNUNullExpr(const GNUNullExpr *E) {
-    return ZeroInitialization(E);
-  }
-
-  bool VisitTypeTraitExpr(const TypeTraitExpr *E) {
-    return Success(E->getValue(), E);
-  }
-
-  bool VisitArrayTypeTraitExpr(const ArrayTypeTraitExpr *E) {
-    return Success(E->getValue(), E);
-  }
-
-  bool VisitExpressionTraitExpr(const ExpressionTraitExpr *E) {
-    return Success(E->getValue(), E);
-  }
-
-  bool VisitUnaryReal(const UnaryOperator *E);
-  bool VisitUnaryImag(const UnaryOperator *E);
-
-  bool VisitCXXNoexceptExpr(const CXXNoexceptExpr *E);
-  bool VisitSizeOfPackExpr(const SizeOfPackExpr *E);
-
-  // FIXME: Missing: array subscript of vector, member of vector
-};
-
-class FixedPointExprEvaluator
-    : public ExprEvaluatorBase<FixedPointExprEvaluator> {
-  APValue &Result;
-
- public:
-  FixedPointExprEvaluator(EvalInfo &info, APValue &result)
-      : ExprEvaluatorBaseTy(info), Result(result) {}
-
-  bool Success(const llvm::APSInt &SI, const Expr *E, APValue &Result) {
-    assert(E->getType()->isFixedPointType() && "Invalid evaluation result.");
-    assert(SI.isSigned() == E->getType()->isSignedFixedPointType() &&
-           "Invalid evaluation result.");
-    assert(SI.getBitWidth() == Info.Ctx.getIntWidth(E->getType()) &&
-           "Invalid evaluation result.");
-    Result = APValue(SI);
-    return true;
-  }
-  bool Success(const llvm::APSInt &SI, const Expr *E) {
-    return Success(SI, E, Result);
-  }
-
-  bool Success(const llvm::APInt &I, const Expr *E, APValue &Result) {
-    assert(E->getType()->isFixedPointType() && "Invalid evaluation result.");
-    assert(I.getBitWidth() == Info.Ctx.getIntWidth(E->getType()) &&
-           "Invalid evaluation result.");
-    Result = APValue(APSInt(I));
-    Result.getInt().setIsUnsigned(E->getType()->isUnsignedFixedPointType());
-    return true;
-  }
-  bool Success(const llvm::APInt &I, const Expr *E) {
-    return Success(I, E, Result);
-  }
-
-  bool Success(uint64_t Value, const Expr *E, APValue &Result) {
-    assert(E->getType()->isFixedPointType() && "Invalid evaluation result.");
-    Result = APValue(Info.Ctx.MakeIntValue(Value, E->getType()));
-    return true;
-  }
-  bool Success(uint64_t Value, const Expr *E) {
-    return Success(Value, E, Result);
-  }
-
-  bool Success(CharUnits Size, const Expr *E) {
-    return Success(Size.getQuantity(), E);
-  }
-
-  bool Success(const APValue &V, const Expr *E) {
-    if (V.isLValue() || V.isAddrLabelDiff()) {
-      Result = V;
-      return true;
-    }
-    return Success(V.getInt(), E);
-  }
-
-  bool ZeroInitialization(const Expr *E) { return Success(0, E); }
-
-  //===--------------------------------------------------------------------===//
-  //                            Visitor Methods
-  //===--------------------------------------------------------------------===//
-
-  bool VisitFixedPointLiteral(const FixedPointLiteral *E) {
-    return Success(E->getValue(), E);
-  }
-
-  bool VisitUnaryOperator(const UnaryOperator *E);
-};
-} // end anonymous namespace
-
-/// EvaluateIntegerOrLValue - Evaluate an rvalue integral-typed expression, and
-/// produce either the integer value or a pointer.
-///
-/// GCC has a heinous extension which folds casts between pointer types and
-/// pointer-sized integral types. We support this by allowing the evaluation of
-/// an integer rvalue to produce a pointer (represented as an lvalue) instead.
-/// Some simple arithmetic on such values is supported (they are treated much
-/// like char*).
-static bool EvaluateIntegerOrLValue(const Expr *E, APValue &Result,
-                                    EvalInfo &Info) {
-  assert(E->isRValue() && E->getType()->isIntegralOrEnumerationType());
-  return IntExprEvaluator(Info, Result).Visit(E);
-}
-
-static bool EvaluateInteger(const Expr *E, APSInt &Result, EvalInfo &Info) {
-  APValue Val;
-  if (!EvaluateIntegerOrLValue(E, Val, Info))
-    return false;
-  if (!Val.isInt()) {
-    // FIXME: It would be better to produce the diagnostic for casting
-    //        a pointer to an integer.
-    Info.FFDiag(E, diag::note_invalid_subexpr_in_const_expr);
-    return false;
-  }
-  Result = Val.getInt();
-  return true;
-}
-
-/// Check whether the given declaration can be directly converted to an integral
-/// rvalue. If not, no diagnostic is produced; there are other things we can
-/// try.
-bool IntExprEvaluator::CheckReferencedDecl(const Expr* E, const Decl* D) {
-  // Enums are integer constant exprs.
-  if (const EnumConstantDecl *ECD = dyn_cast<EnumConstantDecl>(D)) {
-    // Check for signedness/width mismatches between E type and ECD value.
-    bool SameSign = (ECD->getInitVal().isSigned()
-                     == E->getType()->isSignedIntegerOrEnumerationType());
-    bool SameWidth = (ECD->getInitVal().getBitWidth()
-                      == Info.Ctx.getIntWidth(E->getType()));
-    if (SameSign && SameWidth)
-      return Success(ECD->getInitVal(), E);
-    else {
-      // Get rid of mismatch (otherwise Success assertions will fail)
-      // by computing a new value matching the type of E.
-      llvm::APSInt Val = ECD->getInitVal();
-      if (!SameSign)
-        Val.setIsSigned(!ECD->getInitVal().isSigned());
-      if (!SameWidth)
-        Val = Val.extOrTrunc(Info.Ctx.getIntWidth(E->getType()));
-      return Success(Val, E);
-    }
-  }
-  return false;
-}
-
-/// Values returned by __builtin_classify_type, chosen to match the values
-/// produced by GCC's builtin.
-enum class GCCTypeClass {
-  None = -1,
-  Void = 0,
-  Integer = 1,
-  // GCC reserves 2 for character types, but instead classifies them as
-  // integers.
-  Enum = 3,
-  Bool = 4,
-  Pointer = 5,
-  // GCC reserves 6 for references, but appears to never use it (because
-  // expressions never have reference type, presumably).
-  PointerToDataMember = 7,
-  RealFloat = 8,
-  Complex = 9,
-  // GCC reserves 10 for functions, but does not use it since GCC version 6 due
-  // to decay to pointer. (Prior to version 6 it was only used in C++ mode).
-  // GCC claims to reserve 11 for pointers to member functions, but *actually*
-  // uses 12 for that purpose, same as for a class or struct. Maybe it
-  // internally implements a pointer to member as a struct?  Who knows.
-  PointerToMemberFunction = 12, // Not a bug, see above.
-  ClassOrStruct = 12,
-  Union = 13,
-  // GCC reserves 14 for arrays, but does not use it since GCC version 6 due to
-  // decay to pointer. (Prior to version 6 it was only used in C++ mode).
-  // GCC reserves 15 for strings, but actually uses 5 (pointer) for string
-  // literals.
-};
-
-/// EvaluateBuiltinClassifyType - Evaluate __builtin_classify_type the same way
-/// as GCC.
-static GCCTypeClass
-EvaluateBuiltinClassifyType(QualType T, const LangOptions &LangOpts) {
-  assert(!T->isDependentType() && "unexpected dependent type");
-
-  QualType CanTy = T.getCanonicalType();
-  const BuiltinType *BT = dyn_cast<BuiltinType>(CanTy);
-
-  switch (CanTy->getTypeClass()) {
-#define TYPE(ID, BASE)
-#define DEPENDENT_TYPE(ID, BASE) case Type::ID:
-#define NON_CANONICAL_TYPE(ID, BASE) case Type::ID:
-#define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(ID, BASE) case Type::ID:
-#include "clang/AST/TypeNodes.def"
-  case Type::Auto:
-  case Type::DeducedTemplateSpecialization:
-      llvm_unreachable("unexpected non-canonical or dependent type");
-
-  case Type::Builtin:
-    switch (BT->getKind()) {
-#define BUILTIN_TYPE(ID, SINGLETON_ID)
-#define SIGNED_TYPE(ID, SINGLETON_ID) \
-    case BuiltinType::ID: return GCCTypeClass::Integer;
-#define FLOATING_TYPE(ID, SINGLETON_ID) \
-    case BuiltinType::ID: return GCCTypeClass::RealFloat;
-#define PLACEHOLDER_TYPE(ID, SINGLETON_ID) \
-    case BuiltinType::ID: break;
-#include "clang/AST/BuiltinTypes.def"
-    case BuiltinType::Void:
-      return GCCTypeClass::Void;
-
-    case BuiltinType::Bool:
-      return GCCTypeClass::Bool;
-
-    case BuiltinType::Char_U:
-    case BuiltinType::UChar:
-    case BuiltinType::WChar_U:
-    case BuiltinType::Char8:
-    case BuiltinType::Char16:
-    case BuiltinType::Char32:
-    case BuiltinType::UShort:
-    case BuiltinType::UInt:
-    case BuiltinType::ULong:
-    case BuiltinType::ULongLong:
-    case BuiltinType::UInt128:
-      return GCCTypeClass::Integer;
-
-    case BuiltinType::UShortAccum:
-    case BuiltinType::UAccum:
-    case BuiltinType::ULongAccum:
-    case BuiltinType::UShortFract:
-    case BuiltinType::UFract:
-    case BuiltinType::ULongFract:
-    case BuiltinType::SatUShortAccum:
-    case BuiltinType::SatUAccum:
-    case BuiltinType::SatULongAccum:
-    case BuiltinType::SatUShortFract:
-    case BuiltinType::SatUFract:
-    case BuiltinType::SatULongFract:
-      return GCCTypeClass::None;
-
-    case BuiltinType::NullPtr:
-
-    case BuiltinType::ObjCId:
-    case BuiltinType::ObjCClass:
-    case BuiltinType::ObjCSel:
-#define IMAGE_TYPE(ImgType, Id, SingletonId, Access, Suffix) \
-    case BuiltinType::Id:
-#include "clang/Basic/OpenCLImageTypes.def"
-#define EXT_OPAQUE_TYPE(ExtType, Id, Ext) \
-    case BuiltinType::Id:
-#include "clang/Basic/OpenCLExtensionTypes.def"
-    case BuiltinType::OCLSampler:
-    case BuiltinType::OCLEvent:
-    case BuiltinType::OCLClkEvent:
-    case BuiltinType::OCLQueue:
-    case BuiltinType::OCLReserveID:
-      return GCCTypeClass::None;
-
-    case BuiltinType::Dependent:
-      llvm_unreachable("unexpected dependent type");
-    };
-    llvm_unreachable("unexpected placeholder type");
-
-  case Type::Enum:
-    return LangOpts.CPlusPlus ? GCCTypeClass::Enum : GCCTypeClass::Integer;
-
-  case Type::Pointer:
-  case Type::ConstantArray:
-  case Type::VariableArray:
-  case Type::IncompleteArray:
-  case Type::FunctionNoProto:
-  case Type::FunctionProto:
-    return GCCTypeClass::Pointer;
-
-  case Type::MemberPointer:
-    return CanTy->isMemberDataPointerType()
-               ? GCCTypeClass::PointerToDataMember
-               : GCCTypeClass::PointerToMemberFunction;
-
-  case Type::Complex:
-    return GCCTypeClass::Complex;
-
-  case Type::Record:
-    return CanTy->isUnionType() ? GCCTypeClass::Union
-                                : GCCTypeClass::ClassOrStruct;
-
-  case Type::Atomic:
-    // GCC classifies _Atomic T the same as T.
-    return EvaluateBuiltinClassifyType(
-        CanTy->castAs<AtomicType>()->getValueType(), LangOpts);
-
-  case Type::BlockPointer:
-  case Type::Vector:
-  case Type::ExtVector:
-  case Type::ObjCObject:
-  case Type::ObjCInterface:
-  case Type::ObjCObjectPointer:
-  case Type::Pipe:
-    // GCC classifies vectors as None. We follow its lead and classify all
-    // other types that don't fit into the regular classification the same way.
-    return GCCTypeClass::None;
-
-  case Type::LValueReference:
-  case Type::RValueReference:
-    llvm_unreachable("invalid type for expression");
-  }
-
-  llvm_unreachable("unexpected type class");
-}
-
-/// EvaluateBuiltinClassifyType - Evaluate __builtin_classify_type the same way
-/// as GCC.
-static GCCTypeClass
-EvaluateBuiltinClassifyType(const CallExpr *E, const LangOptions &LangOpts) {
-  // If no argument was supplied, default to None. This isn't
-  // ideal, however it is what gcc does.
-  if (E->getNumArgs() == 0)
-    return GCCTypeClass::None;
-
-  // FIXME: Bizarrely, GCC treats a call with more than one argument as not
-  // being an ICE, but still folds it to a constant using the type of the first
-  // argument.
-  return EvaluateBuiltinClassifyType(E->getArg(0)->getType(), LangOpts);
-}
-
-/// EvaluateBuiltinConstantPForLValue - Determine the result of
-/// __builtin_constant_p when applied to the given lvalue.
-///
-/// An lvalue is only "constant" if it is a pointer or reference to the first
-/// character of a string literal.
-template<typename LValue>
-static bool EvaluateBuiltinConstantPForLValue(const LValue &LV) {
-  const Expr *E = LV.getLValueBase().template dyn_cast<const Expr*>();
-  return E && isa<StringLiteral>(E) && LV.getLValueOffset().isZero();
-}
-
-/// EvaluateBuiltinConstantP - Evaluate __builtin_constant_p as similarly to
-/// GCC as we can manage.
-static bool EvaluateBuiltinConstantP(ASTContext &Ctx, const Expr *Arg) {
-  QualType ArgType = Arg->getType();
-
-  // __builtin_constant_p always has one operand. The rules which gcc follows
-  // are not precisely documented, but are as follows:
-  //
-  //  - If the operand is of integral, floating, complex or enumeration type,
-  //    and can be folded to a known value of that type, it returns 1.
-  //  - If the operand and can be folded to a pointer to the first character
-  //    of a string literal (or such a pointer cast to an integral type), it
-  //    returns 1.
-  //
-  // Otherwise, it returns 0.
-  //
-  // FIXME: GCC also intends to return 1 for literals of aggregate types, but
-  // its support for this does not currently work.
-  if (ArgType->isIntegralOrEnumerationType()) {
-    Expr::EvalResult Result;
-    if (!Arg->EvaluateAsRValue(Result, Ctx) || Result.HasSideEffects)
-      return false;
-
-    APValue &V = Result.Val;
-    if (V.getKind() == APValue::Int)
-      return true;
-    if (V.getKind() == APValue::LValue)
-      return EvaluateBuiltinConstantPForLValue(V);
-  } else if (ArgType->isFloatingType() || ArgType->isAnyComplexType()) {
-    return Arg->isEvaluatable(Ctx);
-  } else if (ArgType->isPointerType() || Arg->isGLValue()) {
-    LValue LV;
-    Expr::EvalStatus Status;
-    EvalInfo Info(Ctx, Status, EvalInfo::EM_ConstantFold);
-    if ((Arg->isGLValue() ? EvaluateLValue(Arg, LV, Info)
-                          : EvaluatePointer(Arg, LV, Info)) &&
-        !Status.HasSideEffects)
-      return EvaluateBuiltinConstantPForLValue(LV);
-  }
-
-  // Anything else isn't considered to be sufficiently constant.
-  return false;
-}
-
-/// Retrieves the "underlying object type" of the given expression,
-/// as used by __builtin_object_size.
-static QualType getObjectType(APValue::LValueBase B) {
-  if (const ValueDecl *D = B.dyn_cast<const ValueDecl*>()) {
-    if (const VarDecl *VD = dyn_cast<VarDecl>(D))
-      return VD->getType();
-  } else if (const Expr *E = B.get<const Expr*>()) {
-    if (isa<CompoundLiteralExpr>(E))
-      return E->getType();
-  }
-
-  return QualType();
-}
-
-/// A more selective version of E->IgnoreParenCasts for
-/// tryEvaluateBuiltinObjectSize. This ignores some casts/parens that serve only
-/// to change the type of E.
-/// Ex. For E = `(short*)((char*)(&foo))`, returns `&foo`
-///
-/// Always returns an RValue with a pointer representation.
-static const Expr *ignorePointerCastsAndParens(const Expr *E) {
-  assert(E->isRValue() && E->getType()->hasPointerRepresentation());
-
-  auto *NoParens = E->IgnoreParens();
-  auto *Cast = dyn_cast<CastExpr>(NoParens);
-  if (Cast == nullptr)
-    return NoParens;
-
-  // We only conservatively allow a few kinds of casts, because this code is
-  // inherently a simple solution that seeks to support the common case.
-  auto CastKind = Cast->getCastKind();
-  if (CastKind != CK_NoOp && CastKind != CK_BitCast &&
-      CastKind != CK_AddressSpaceConversion)
-    return NoParens;
-
-  auto *SubExpr = Cast->getSubExpr();
-  if (!SubExpr->getType()->hasPointerRepresentation() || !SubExpr->isRValue())
-    return NoParens;
-  return ignorePointerCastsAndParens(SubExpr);
-}
-
-/// Checks to see if the given LValue's Designator is at the end of the LValue's
-/// record layout. e.g.
-///   struct { struct { int a, b; } fst, snd; } obj;
-///   obj.fst   // no
-///   obj.snd   // yes
-///   obj.fst.a // no
-///   obj.fst.b // no
-///   obj.snd.a // no
-///   obj.snd.b // yes
-///
-/// Please note: this function is specialized for how __builtin_object_size
-/// views "objects".
-///
-/// If this encounters an invalid RecordDecl or otherwise cannot determine the
-/// correct result, it will always return true.
-static bool isDesignatorAtObjectEnd(const ASTContext &Ctx, const LValue &LVal) {
-  assert(!LVal.Designator.Invalid);
-
-  auto IsLastOrInvalidFieldDecl = [&Ctx](const FieldDecl *FD, bool &Invalid) {
-    const RecordDecl *Parent = FD->getParent();
-    Invalid = Parent->isInvalidDecl();
-    if (Invalid || Parent->isUnion())
-      return true;
-    const ASTRecordLayout &Layout = Ctx.getASTRecordLayout(Parent);
-    return FD->getFieldIndex() + 1 == Layout.getFieldCount();
-  };
-
-  auto &Base = LVal.getLValueBase();
-  if (auto *ME = dyn_cast_or_null<MemberExpr>(Base.dyn_cast<const Expr *>())) {
-    if (auto *FD = dyn_cast<FieldDecl>(ME->getMemberDecl())) {
-      bool Invalid;
-      if (!IsLastOrInvalidFieldDecl(FD, Invalid))
-        return Invalid;
-    } else if (auto *IFD = dyn_cast<IndirectFieldDecl>(ME->getMemberDecl())) {
-      for (auto *FD : IFD->chain()) {
-        bool Invalid;
-        if (!IsLastOrInvalidFieldDecl(cast<FieldDecl>(FD), Invalid))
-          return Invalid;
-      }
-    }
-  }
-
-  unsigned I = 0;
-  QualType BaseType = getType(Base);
-  if (LVal.Designator.FirstEntryIsAnUnsizedArray) {
-    // If we don't know the array bound, conservatively assume we're looking at
-    // the final array element.
-    ++I;
-    if (BaseType->isIncompleteArrayType())
-      BaseType = Ctx.getAsArrayType(BaseType)->getElementType();
-    else
-      BaseType = BaseType->castAs<PointerType>()->getPointeeType();
-  }
-
-  for (unsigned E = LVal.Designator.Entries.size(); I != E; ++I) {
-    const auto &Entry = LVal.Designator.Entries[I];
-    if (BaseType->isArrayType()) {
-      // Because __builtin_object_size treats arrays as objects, we can ignore
-      // the index iff this is the last array in the Designator.
-      if (I + 1 == E)
-        return true;
-      const auto *CAT = cast<ConstantArrayType>(Ctx.getAsArrayType(BaseType));
-      uint64_t Index = Entry.ArrayIndex;
-      if (Index + 1 != CAT->getSize())
-        return false;
-      BaseType = CAT->getElementType();
-    } else if (BaseType->isAnyComplexType()) {
-      const auto *CT = BaseType->castAs<ComplexType>();
-      uint64_t Index = Entry.ArrayIndex;
-      if (Index != 1)
-        return false;
-      BaseType = CT->getElementType();
-    } else if (auto *FD = getAsField(Entry)) {
-      bool Invalid;
-      if (!IsLastOrInvalidFieldDecl(FD, Invalid))
-        return Invalid;
-      BaseType = FD->getType();
-    } else {
-      assert(getAsBaseClass(Entry) && "Expecting cast to a base class");
-      return false;
-    }
-  }
-  return true;
-}
-
-/// Tests to see if the LValue has a user-specified designator (that isn't
-/// necessarily valid). Note that this always returns 'true' if the LValue has
-/// an unsized array as its first designator entry, because there's currently no
-/// way to tell if the user typed *foo or foo[0].
-static bool refersToCompleteObject(const LValue &LVal) {
-  if (LVal.Designator.Invalid)
-    return false;
-
-  if (!LVal.Designator.Entries.empty())
-    return LVal.Designator.isMostDerivedAnUnsizedArray();
-
-  if (!LVal.InvalidBase)
-    return true;
-
-  // If `E` is a MemberExpr, then the first part of the designator is hiding in
-  // the LValueBase.
-  const auto *E = LVal.Base.dyn_cast<const Expr *>();
-  return !E || !isa<MemberExpr>(E);
-}
-
-/// Attempts to detect a user writing into a piece of memory that's impossible
-/// to figure out the size of by just using types.
-static bool isUserWritingOffTheEnd(const ASTContext &Ctx, const LValue &LVal) {
-  const SubobjectDesignator &Designator = LVal.Designator;
-  // Notes:
-  // - Users can only write off of the end when we have an invalid base. Invalid
-  //   bases imply we don't know where the memory came from.
-  // - We used to be a bit more aggressive here; we'd only be conservative if
-  //   the array at the end was flexible, or if it had 0 or 1 elements. This
-  //   broke some common standard library extensions (PR30346), but was
-  //   otherwise seemingly fine. It may be useful to reintroduce this behavior
-  //   with some sort of whitelist. OTOH, it seems that GCC is always
-  //   conservative with the last element in structs (if it's an array), so our
-  //   current behavior is more compatible than a whitelisting approach would
-  //   be.
-  return LVal.InvalidBase &&
-         Designator.Entries.size() == Designator.MostDerivedPathLength &&
-         Designator.MostDerivedIsArrayElement &&
-         isDesignatorAtObjectEnd(Ctx, LVal);
-}
-
-/// Converts the given APInt to CharUnits, assuming the APInt is unsigned.
-/// Fails if the conversion would cause loss of precision.
-static bool convertUnsignedAPIntToCharUnits(const llvm::APInt &Int,
-                                            CharUnits &Result) {
-  auto CharUnitsMax = std::numeric_limits<CharUnits::QuantityType>::max();
-  if (Int.ugt(CharUnitsMax))
-    return false;
-  Result = CharUnits::fromQuantity(Int.getZExtValue());
-  return true;
-}
-
-/// Helper for tryEvaluateBuiltinObjectSize -- Given an LValue, this will
-/// determine how many bytes exist from the beginning of the object to either
-/// the end of the current subobject, or the end of the object itself, depending
-/// on what the LValue looks like + the value of Type.
-///
-/// If this returns false, the value of Result is undefined.
-static bool determineEndOffset(EvalInfo &Info, SourceLocation ExprLoc,
-                               unsigned Type, const LValue &LVal,
-                               CharUnits &EndOffset) {
-  bool DetermineForCompleteObject = refersToCompleteObject(LVal);
-
-  auto CheckedHandleSizeof = [&](QualType Ty, CharUnits &Result) {
-    if (Ty.isNull() || Ty->isIncompleteType() || Ty->isFunctionType())
-      return false;
-    return HandleSizeof(Info, ExprLoc, Ty, Result);
-  };
-
-  // We want to evaluate the size of the entire object. This is a valid fallback
-  // for when Type=1 and the designator is invalid, because we're asked for an
-  // upper-bound.
-  if (!(Type & 1) || LVal.Designator.Invalid || DetermineForCompleteObject) {
-    // Type=3 wants a lower bound, so we can't fall back to this.
-    if (Type == 3 && !DetermineForCompleteObject)
-      return false;
-
-    llvm::APInt APEndOffset;
-    if (isBaseAnAllocSizeCall(LVal.getLValueBase()) &&
-        getBytesReturnedByAllocSizeCall(Info.Ctx, LVal, APEndOffset))
-      return convertUnsignedAPIntToCharUnits(APEndOffset, EndOffset);
-
-    if (LVal.InvalidBase)
-      return false;
-
-    QualType BaseTy = getObjectType(LVal.getLValueBase());
-    return CheckedHandleSizeof(BaseTy, EndOffset);
-  }
-
-  // We want to evaluate the size of a subobject.
-  const SubobjectDesignator &Designator = LVal.Designator;
-
-  // The following is a moderately common idiom in C:
-  //
-  // struct Foo { int a; char c[1]; };
-  // struct Foo *F = (struct Foo *)malloc(sizeof(struct Foo) + strlen(Bar));
-  // strcpy(&F->c[0], Bar);
-  //
-  // In order to not break too much legacy code, we need to support it.
-  if (isUserWritingOffTheEnd(Info.Ctx, LVal)) {
-    // If we can resolve this to an alloc_size call, we can hand that back,
-    // because we know for certain how many bytes there are to write to.
-    llvm::APInt APEndOffset;
-    if (isBaseAnAllocSizeCall(LVal.getLValueBase()) &&
-        getBytesReturnedByAllocSizeCall(Info.Ctx, LVal, APEndOffset))
-      return convertUnsignedAPIntToCharUnits(APEndOffset, EndOffset);
-
-    // If we cannot determine the size of the initial allocation, then we can't
-    // given an accurate upper-bound. However, we are still able to give
-    // conservative lower-bounds for Type=3.
-    if (Type == 1)
-      return false;
-  }
-
-  CharUnits BytesPerElem;
-  if (!CheckedHandleSizeof(Designator.MostDerivedType, BytesPerElem))
-    return false;
-
-  // According to the GCC documentation, we want the size of the subobject
-  // denoted by the pointer. But that's not quite right -- what we actually
-  // want is the size of the immediately-enclosing array, if there is one.
-  int64_t ElemsRemaining;
-  if (Designator.MostDerivedIsArrayElement &&
-      Designator.Entries.size() == Designator.MostDerivedPathLength) {
-    uint64_t ArraySize = Designator.getMostDerivedArraySize();
-    uint64_t ArrayIndex = Designator.Entries.back().ArrayIndex;
-    ElemsRemaining = ArraySize <= ArrayIndex ? 0 : ArraySize - ArrayIndex;
-  } else {
-    ElemsRemaining = Designator.isOnePastTheEnd() ? 0 : 1;
-  }
-
-  EndOffset = LVal.getLValueOffset() + BytesPerElem * ElemsRemaining;
-  return true;
-}
-
-/// Tries to evaluate the __builtin_object_size for @p E. If successful,
-/// returns true and stores the result in @p Size.
-///
-/// If @p WasError is non-null, this will report whether the failure to evaluate
-/// is to be treated as an Error in IntExprEvaluator.
-static bool tryEvaluateBuiltinObjectSize(const Expr *E, unsigned Type,
-                                         EvalInfo &Info, uint64_t &Size) {
-  // Determine the denoted object.
-  LValue LVal;
-  {
-    // The operand of __builtin_object_size is never evaluated for side-effects.
-    // If there are any, but we can determine the pointed-to object anyway, then
-    // ignore the side-effects.
-    SpeculativeEvaluationRAII SpeculativeEval(Info);
-    IgnoreSideEffectsRAII Fold(Info);
-
-    if (E->isGLValue()) {
-      // It's possible for us to be given GLValues if we're called via
-      // Expr::tryEvaluateObjectSize.
-      APValue RVal;
-      if (!EvaluateAsRValue(Info, E, RVal))
-        return false;
-      LVal.setFrom(Info.Ctx, RVal);
-    } else if (!EvaluatePointer(ignorePointerCastsAndParens(E), LVal, Info,
-                                /*InvalidBaseOK=*/true))
-      return false;
-  }
-
-  // If we point to before the start of the object, there are no accessible
-  // bytes.
-  if (LVal.getLValueOffset().isNegative()) {
-    Size = 0;
-    return true;
-  }
-
-  CharUnits EndOffset;
-  if (!determineEndOffset(Info, E->getExprLoc(), Type, LVal, EndOffset))
-    return false;
-
-  // If we've fallen outside of the end offset, just pretend there's nothing to
-  // write to/read from.
-  if (EndOffset <= LVal.getLValueOffset())
-    Size = 0;
-  else
-    Size = (EndOffset - LVal.getLValueOffset()).getQuantity();
-  return true;
-}
-
-bool IntExprEvaluator::VisitConstantExpr(const ConstantExpr *E) {
-  llvm::SaveAndRestore<bool> InConstantContext(Info.InConstantContext, true);
-  return ExprEvaluatorBaseTy::VisitConstantExpr(E);
-}
-
-bool IntExprEvaluator::VisitCallExpr(const CallExpr *E) {
-  if (unsigned BuiltinOp = E->getBuiltinCallee())
-    return VisitBuiltinCallExpr(E, BuiltinOp);
-
-  return ExprEvaluatorBaseTy::VisitCallExpr(E);
-}
-
-bool IntExprEvaluator::VisitBuiltinCallExpr(const CallExpr *E,
-                                            unsigned BuiltinOp) {
-  switch (unsigned BuiltinOp = E->getBuiltinCallee()) {
-  default:
-    return ExprEvaluatorBaseTy::VisitCallExpr(E);
-
-  case Builtin::BI__builtin_object_size: {
-    // The type was checked when we built the expression.
-    unsigned Type =
-        E->getArg(1)->EvaluateKnownConstInt(Info.Ctx).getZExtValue();
-    assert(Type <= 3 && "unexpected type");
-
-    uint64_t Size;
-    if (tryEvaluateBuiltinObjectSize(E->getArg(0), Type, Info, Size))
-      return Success(Size, E);
-
-    if (E->getArg(0)->HasSideEffects(Info.Ctx))
-      return Success((Type & 2) ? 0 : -1, E);
-
-    // Expression had no side effects, but we couldn't statically determine the
-    // size of the referenced object.
-    switch (Info.EvalMode) {
-    case EvalInfo::EM_ConstantExpression:
-    case EvalInfo::EM_PotentialConstantExpression:
-    case EvalInfo::EM_ConstantFold:
-    case EvalInfo::EM_EvaluateForOverflow:
-    case EvalInfo::EM_IgnoreSideEffects:
-      // Leave it to IR generation.
-      return Error(E);
-    case EvalInfo::EM_ConstantExpressionUnevaluated:
-    case EvalInfo::EM_PotentialConstantExpressionUnevaluated:
-      // Reduce it to a constant now.
-      return Success((Type & 2) ? 0 : -1, E);
-    }
-
-    llvm_unreachable("unexpected EvalMode");
-  }
-
-  case Builtin::BI__builtin_os_log_format_buffer_size: {
-    analyze_os_log::OSLogBufferLayout Layout;
-    analyze_os_log::computeOSLogBufferLayout(Info.Ctx, E, Layout);
-    return Success(Layout.size().getQuantity(), E);
-  }
-
-  case Builtin::BI__builtin_bswap16:
-  case Builtin::BI__builtin_bswap32:
-  case Builtin::BI__builtin_bswap64: {
-    APSInt Val;
-    if (!EvaluateInteger(E->getArg(0), Val, Info))
-      return false;
-
-    return Success(Val.byteSwap(), E);
-  }
-
-  case Builtin::BI__builtin_classify_type:
-    return Success((int)EvaluateBuiltinClassifyType(E, Info.getLangOpts()), E);
-
-  case Builtin::BI__builtin_clrsb:
-  case Builtin::BI__builtin_clrsbl:
-  case Builtin::BI__builtin_clrsbll: {
-    APSInt Val;
-    if (!EvaluateInteger(E->getArg(0), Val, Info))
-      return false;
-
-    return Success(Val.getBitWidth() - Val.getMinSignedBits(), E);
-  }
-
-  case Builtin::BI__builtin_clz:
-  case Builtin::BI__builtin_clzl:
-  case Builtin::BI__builtin_clzll:
-  case Builtin::BI__builtin_clzs: {
-    APSInt Val;
-    if (!EvaluateInteger(E->getArg(0), Val, Info))
-      return false;
-    if (!Val)
-      return Error(E);
-
-    return Success(Val.countLeadingZeros(), E);
-  }
-
-  case Builtin::BI__builtin_constant_p: {
-    auto Arg = E->getArg(0);
-    if (EvaluateBuiltinConstantP(Info.Ctx, Arg))
-      return Success(true, E);
-    auto ArgTy = Arg->IgnoreImplicit()->getType();
-    if (!Info.InConstantContext && !Arg->HasSideEffects(Info.Ctx) &&
-        !ArgTy->isAggregateType() && !ArgTy->isPointerType()) {
-      // We can delay calculation of __builtin_constant_p until after
-      // inlining. Note: This diagnostic won't be shown to the user.
-      Info.FFDiag(E, diag::note_invalid_subexpr_in_const_expr);
-      return false;
-    }
-    return Success(false, E);
-  }
-
-  case Builtin::BI__builtin_ctz:
-  case Builtin::BI__builtin_ctzl:
-  case Builtin::BI__builtin_ctzll:
-  case Builtin::BI__builtin_ctzs: {
-    APSInt Val;
-    if (!EvaluateInteger(E->getArg(0), Val, Info))
-      return false;
-    if (!Val)
-      return Error(E);
-
-    return Success(Val.countTrailingZeros(), E);
-  }
-
-  case Builtin::BI__builtin_eh_return_data_regno: {
-    int Operand = E->getArg(0)->EvaluateKnownConstInt(Info.Ctx).getZExtValue();
-    Operand = Info.Ctx.getTargetInfo().getEHDataRegisterNumber(Operand);
-    return Success(Operand, E);
-  }
-
-  case Builtin::BI__builtin_expect:
-    return Visit(E->getArg(0));
-
-  case Builtin::BI__builtin_ffs:
-  case Builtin::BI__builtin_ffsl:
-  case Builtin::BI__builtin_ffsll: {
-    APSInt Val;
-    if (!EvaluateInteger(E->getArg(0), Val, Info))
-      return false;
-
-    unsigned N = Val.countTrailingZeros();
-    return Success(N == Val.getBitWidth() ? 0 : N + 1, E);
-  }
-
-  case Builtin::BI__builtin_fpclassify: {
-    APFloat Val(0.0);
-    if (!EvaluateFloat(E->getArg(5), Val, Info))
-      return false;
-    unsigned Arg;
-    switch (Val.getCategory()) {
-    case APFloat::fcNaN: Arg = 0; break;
-    case APFloat::fcInfinity: Arg = 1; break;
-    case APFloat::fcNormal: Arg = Val.isDenormal() ? 3 : 2; break;
-    case APFloat::fcZero: Arg = 4; break;
-    }
-    return Visit(E->getArg(Arg));
-  }
-
-  case Builtin::BI__builtin_isinf_sign: {
-    APFloat Val(0.0);
-    return EvaluateFloat(E->getArg(0), Val, Info) &&
-           Success(Val.isInfinity() ? (Val.isNegative() ? -1 : 1) : 0, E);
-  }
-
-  case Builtin::BI__builtin_isinf: {
-    APFloat Val(0.0);
-    return EvaluateFloat(E->getArg(0), Val, Info) &&
-           Success(Val.isInfinity() ? 1 : 0, E);
-  }
-
-  case Builtin::BI__builtin_isfinite: {
-    APFloat Val(0.0);
-    return EvaluateFloat(E->getArg(0), Val, Info) &&
-           Success(Val.isFinite() ? 1 : 0, E);
-  }
-
-  case Builtin::BI__builtin_isnan: {
-    APFloat Val(0.0);
-    return EvaluateFloat(E->getArg(0), Val, Info) &&
-           Success(Val.isNaN() ? 1 : 0, E);
-  }
-
-  case Builtin::BI__builtin_isnormal: {
-    APFloat Val(0.0);
-    return EvaluateFloat(E->getArg(0), Val, Info) &&
-           Success(Val.isNormal() ? 1 : 0, E);
-  }
-
-  case Builtin::BI__builtin_parity:
-  case Builtin::BI__builtin_parityl:
-  case Builtin::BI__builtin_parityll: {
-    APSInt Val;
-    if (!EvaluateInteger(E->getArg(0), Val, Info))
-      return false;
-
-    return Success(Val.countPopulation() % 2, E);
-  }
-
-  case Builtin::BI__builtin_popcount:
-  case Builtin::BI__builtin_popcountl:
-  case Builtin::BI__builtin_popcountll: {
-    APSInt Val;
-    if (!EvaluateInteger(E->getArg(0), Val, Info))
-      return false;
-
-    return Success(Val.countPopulation(), E);
-  }
-
-  case Builtin::BIstrlen:
-  case Builtin::BIwcslen:
-    // A call to strlen is not a constant expression.
-    if (Info.getLangOpts().CPlusPlus11)
-      Info.CCEDiag(E, diag::note_constexpr_invalid_function)
-        << /*isConstexpr*/0 << /*isConstructor*/0
-        << (std::string("'") + Info.Ctx.BuiltinInfo.getName(BuiltinOp) + "'");
-    else
-      Info.CCEDiag(E, diag::note_invalid_subexpr_in_const_expr);
-    LLVM_FALLTHROUGH;
-  case Builtin::BI__builtin_strlen:
-  case Builtin::BI__builtin_wcslen: {
-    // As an extension, we support __builtin_strlen() as a constant expression,
-    // and support folding strlen() to a constant.
-    LValue String;
-    if (!EvaluatePointer(E->getArg(0), String, Info))
-      return false;
-
-    QualType CharTy = E->getArg(0)->getType()->getPointeeType();
-
-    // Fast path: if it's a string literal, search the string value.
-    if (const StringLiteral *S = dyn_cast_or_null<StringLiteral>(
-            String.getLValueBase().dyn_cast<const Expr *>())) {
-      // The string literal may have embedded null characters. Find the first
-      // one and truncate there.
-      StringRef Str = S->getBytes();
-      int64_t Off = String.Offset.getQuantity();
-      if (Off >= 0 && (uint64_t)Off <= (uint64_t)Str.size() &&
-          S->getCharByteWidth() == 1 &&
-          // FIXME: Add fast-path for wchar_t too.
-          Info.Ctx.hasSameUnqualifiedType(CharTy, Info.Ctx.CharTy)) {
-        Str = Str.substr(Off);
-
-        StringRef::size_type Pos = Str.find(0);
-        if (Pos != StringRef::npos)
-          Str = Str.substr(0, Pos);
-
-        return Success(Str.size(), E);
-      }
-
-      // Fall through to slow path to issue appropriate diagnostic.
-    }
-
-    // Slow path: scan the bytes of the string looking for the terminating 0.
-    for (uint64_t Strlen = 0; /**/; ++Strlen) {
-      APValue Char;
-      if (!handleLValueToRValueConversion(Info, E, CharTy, String, Char) ||
-          !Char.isInt())
-        return false;
-      if (!Char.getInt())
-        return Success(Strlen, E);
-      if (!HandleLValueArrayAdjustment(Info, E, String, CharTy, 1))
-        return false;
-    }
-  }
-
-  case Builtin::BIstrcmp:
-  case Builtin::BIwcscmp:
-  case Builtin::BIstrncmp:
-  case Builtin::BIwcsncmp:
-  case Builtin::BImemcmp:
-  case Builtin::BIwmemcmp:
-    // A call to strlen is not a constant expression.
-    if (Info.getLangOpts().CPlusPlus11)
-      Info.CCEDiag(E, diag::note_constexpr_invalid_function)
-        << /*isConstexpr*/0 << /*isConstructor*/0
-        << (std::string("'") + Info.Ctx.BuiltinInfo.getName(BuiltinOp) + "'");
-    else
-      Info.CCEDiag(E, diag::note_invalid_subexpr_in_const_expr);
-    LLVM_FALLTHROUGH;
-  case Builtin::BI__builtin_strcmp:
-  case Builtin::BI__builtin_wcscmp:
-  case Builtin::BI__builtin_strncmp:
-  case Builtin::BI__builtin_wcsncmp:
-  case Builtin::BI__builtin_memcmp:
-  case Builtin::BI__builtin_wmemcmp: {
-    LValue String1, String2;
-    if (!EvaluatePointer(E->getArg(0), String1, Info) ||
-        !EvaluatePointer(E->getArg(1), String2, Info))
-      return false;
-
-    uint64_t MaxLength = uint64_t(-1);
-    if (BuiltinOp != Builtin::BIstrcmp &&
-        BuiltinOp != Builtin::BIwcscmp &&
-        BuiltinOp != Builtin::BI__builtin_strcmp &&
-        BuiltinOp != Builtin::BI__builtin_wcscmp) {
-      APSInt N;
-      if (!EvaluateInteger(E->getArg(2), N, Info))
-        return false;
-      MaxLength = N.getExtValue();
-    }
-
-    // Empty substrings compare equal by definition.
-    if (MaxLength == 0u)
-      return Success(0, E);
-
-    if (!String1.checkNullPointerForFoldAccess(Info, E, AK_Read) ||
-        !String2.checkNullPointerForFoldAccess(Info, E, AK_Read) ||
-        String1.Designator.Invalid || String2.Designator.Invalid)
-      return false;
-
-    QualType CharTy1 = String1.Designator.getType(Info.Ctx);
-    QualType CharTy2 = String2.Designator.getType(Info.Ctx);
-
-    bool IsRawByte = BuiltinOp == Builtin::BImemcmp ||
-                     BuiltinOp == Builtin::BI__builtin_memcmp;
-
-    assert(IsRawByte ||
-           (Info.Ctx.hasSameUnqualifiedType(
-                CharTy1, E->getArg(0)->getType()->getPointeeType()) &&
-            Info.Ctx.hasSameUnqualifiedType(CharTy1, CharTy2)));
-
-    const auto &ReadCurElems = [&](APValue &Char1, APValue &Char2) {
-      return handleLValueToRValueConversion(Info, E, CharTy1, String1, Char1) &&
-             handleLValueToRValueConversion(Info, E, CharTy2, String2, Char2) &&
-             Char1.isInt() && Char2.isInt();
-    };
-    const auto &AdvanceElems = [&] {
-      return HandleLValueArrayAdjustment(Info, E, String1, CharTy1, 1) &&
-             HandleLValueArrayAdjustment(Info, E, String2, CharTy2, 1);
-    };
-
-    if (IsRawByte) {
-      uint64_t BytesRemaining = MaxLength;
-      // Pointers to const void may point to objects of incomplete type.
-      if (CharTy1->isIncompleteType()) {
-        Info.FFDiag(E, diag::note_constexpr_ltor_incomplete_type) << CharTy1;
-        return false;
-      }
-      if (CharTy2->isIncompleteType()) {
-        Info.FFDiag(E, diag::note_constexpr_ltor_incomplete_type) << CharTy2;
-        return false;
-      }
-      uint64_t CharTy1Width{Info.Ctx.getTypeSize(CharTy1)};
-      CharUnits CharTy1Size = Info.Ctx.toCharUnitsFromBits(CharTy1Width);
-      // Give up on comparing between elements with disparate widths.
-      if (CharTy1Size != Info.Ctx.getTypeSizeInChars(CharTy2))
-        return false;
-      uint64_t BytesPerElement = CharTy1Size.getQuantity();
-      assert(BytesRemaining && "BytesRemaining should not be zero: the "
-                               "following loop considers at least one element");
-      while (true) {
-        APValue Char1, Char2;
-        if (!ReadCurElems(Char1, Char2))
-          return false;
-        // We have compatible in-memory widths, but a possible type and
-        // (for `bool`) internal representation mismatch.
-        // Assuming two's complement representation, including 0 for `false` and
-        // 1 for `true`, we can check an appropriate number of elements for
-        // equality even if they are not byte-sized.
-        APSInt Char1InMem = Char1.getInt().extOrTrunc(CharTy1Width);
-        APSInt Char2InMem = Char2.getInt().extOrTrunc(CharTy1Width);
-        if (Char1InMem.ne(Char2InMem)) {
-          // If the elements are byte-sized, then we can produce a three-way
-          // comparison result in a straightforward manner.
-          if (BytesPerElement == 1u) {
-            // memcmp always compares unsigned chars.
-            return Success(Char1InMem.ult(Char2InMem) ? -1 : 1, E);
-          }
-          // The result is byte-order sensitive, and we have multibyte elements.
-          // FIXME: We can compare the remaining bytes in the correct order.
-          return false;
-        }
-        if (!AdvanceElems())
-          return false;
-        if (BytesRemaining <= BytesPerElement)
-          break;
-        BytesRemaining -= BytesPerElement;
-      }
-      // Enough elements are equal to account for the memcmp limit.
-      return Success(0, E);
-    }
-
-    bool StopAtNull = (BuiltinOp != Builtin::BImemcmp &&
-                       BuiltinOp != Builtin::BIwmemcmp &&
-                       BuiltinOp != Builtin::BI__builtin_memcmp &&
-                       BuiltinOp != Builtin::BI__builtin_wmemcmp);
-    bool IsWide = BuiltinOp == Builtin::BIwcscmp ||
-                  BuiltinOp == Builtin::BIwcsncmp ||
-                  BuiltinOp == Builtin::BIwmemcmp ||
-                  BuiltinOp == Builtin::BI__builtin_wcscmp ||
-                  BuiltinOp == Builtin::BI__builtin_wcsncmp ||
-                  BuiltinOp == Builtin::BI__builtin_wmemcmp;
-
-    for (; MaxLength; --MaxLength) {
-      APValue Char1, Char2;
-      if (!ReadCurElems(Char1, Char2))
-        return false;
-      if (Char1.getInt() != Char2.getInt()) {
-        if (IsWide) // wmemcmp compares with wchar_t signedness.
-          return Success(Char1.getInt() < Char2.getInt() ? -1 : 1, E);
-        // memcmp always compares unsigned chars.
-        return Success(Char1.getInt().ult(Char2.getInt()) ? -1 : 1, E);
-      }
-      if (StopAtNull && !Char1.getInt())
-        return Success(0, E);
-      assert(!(StopAtNull && !Char2.getInt()));
-      if (!AdvanceElems())
-        return false;
-    }
-    // We hit the strncmp / memcmp limit.
-    return Success(0, E);
-  }
-
-  case Builtin::BI__atomic_always_lock_free:
-  case Builtin::BI__atomic_is_lock_free:
-  case Builtin::BI__c11_atomic_is_lock_free: {
-    APSInt SizeVal;
-    if (!EvaluateInteger(E->getArg(0), SizeVal, Info))
-      return false;
-
-    // For __atomic_is_lock_free(sizeof(_Atomic(T))), if the size is a power
-    // of two less than the maximum inline atomic width, we know it is
-    // lock-free.  If the size isn't a power of two, or greater than the
-    // maximum alignment where we promote atomics, we know it is not lock-free
-    // (at least not in the sense of atomic_is_lock_free).  Otherwise,
-    // the answer can only be determined at runtime; for example, 16-byte
-    // atomics have lock-free implementations on some, but not all,
-    // x86-64 processors.
-
-    // Check power-of-two.
-    CharUnits Size = CharUnits::fromQuantity(SizeVal.getZExtValue());
-    if (Size.isPowerOfTwo()) {
-      // Check against inlining width.
-      unsigned InlineWidthBits =
-          Info.Ctx.getTargetInfo().getMaxAtomicInlineWidth();
-      if (Size <= Info.Ctx.toCharUnitsFromBits(InlineWidthBits)) {
-        if (BuiltinOp == Builtin::BI__c11_atomic_is_lock_free ||
-            Size == CharUnits::One() ||
-            E->getArg(1)->isNullPointerConstant(Info.Ctx,
-                                                Expr::NPC_NeverValueDependent))
-          // OK, we will inline appropriately-aligned operations of this size,
-          // and _Atomic(T) is appropriately-aligned.
-          return Success(1, E);
-
-        QualType PointeeType = E->getArg(1)->IgnoreImpCasts()->getType()->
-          castAs<PointerType>()->getPointeeType();
-        if (!PointeeType->isIncompleteType() &&
-            Info.Ctx.getTypeAlignInChars(PointeeType) >= Size) {
-          // OK, we will inline operations on this object.
-          return Success(1, E);
-        }
-      }
-    }
-
-    return BuiltinOp == Builtin::BI__atomic_always_lock_free ?
-        Success(0, E) : Error(E);
-  }
-  case Builtin::BIomp_is_initial_device:
-    // We can decide statically which value the runtime would return if called.
-    return Success(Info.getLangOpts().OpenMPIsDevice ? 0 : 1, E);
-  case Builtin::BI__builtin_add_overflow:
-  case Builtin::BI__builtin_sub_overflow:
-  case Builtin::BI__builtin_mul_overflow:
-  case Builtin::BI__builtin_sadd_overflow:
-  case Builtin::BI__builtin_uadd_overflow:
-  case Builtin::BI__builtin_uaddl_overflow:
-  case Builtin::BI__builtin_uaddll_overflow:
-  case Builtin::BI__builtin_usub_overflow:
-  case Builtin::BI__builtin_usubl_overflow:
-  case Builtin::BI__builtin_usubll_overflow:
-  case Builtin::BI__builtin_umul_overflow:
-  case Builtin::BI__builtin_umull_overflow:
-  case Builtin::BI__builtin_umulll_overflow:
-  case Builtin::BI__builtin_saddl_overflow:
-  case Builtin::BI__builtin_saddll_overflow:
-  case Builtin::BI__builtin_ssub_overflow:
-  case Builtin::BI__builtin_ssubl_overflow:
-  case Builtin::BI__builtin_ssubll_overflow:
-  case Builtin::BI__builtin_smul_overflow:
-  case Builtin::BI__builtin_smull_overflow:
-  case Builtin::BI__builtin_smulll_overflow: {
-    LValue ResultLValue;
-    APSInt LHS, RHS;
-
-    QualType ResultType = E->getArg(2)->getType()->getPointeeType();
-    if (!EvaluateInteger(E->getArg(0), LHS, Info) ||
-        !EvaluateInteger(E->getArg(1), RHS, Info) ||
-        !EvaluatePointer(E->getArg(2), ResultLValue, Info))
-      return false;
-
-    APSInt Result;
-    bool DidOverflow = false;
-
-    // If the types don't have to match, enlarge all 3 to the largest of them.
-    if (BuiltinOp == Builtin::BI__builtin_add_overflow ||
-        BuiltinOp == Builtin::BI__builtin_sub_overflow ||
-        BuiltinOp == Builtin::BI__builtin_mul_overflow) {
-      bool IsSigned = LHS.isSigned() || RHS.isSigned() ||
-                      ResultType->isSignedIntegerOrEnumerationType();
-      bool AllSigned = LHS.isSigned() && RHS.isSigned() &&
-                      ResultType->isSignedIntegerOrEnumerationType();
-      uint64_t LHSSize = LHS.getBitWidth();
-      uint64_t RHSSize = RHS.getBitWidth();
-      uint64_t ResultSize = Info.Ctx.getTypeSize(ResultType);
-      uint64_t MaxBits = std::max(std::max(LHSSize, RHSSize), ResultSize);
-
-      // Add an additional bit if the signedness isn't uniformly agreed to. We
-      // could do this ONLY if there is a signed and an unsigned that both have
-      // MaxBits, but the code to check that is pretty nasty.  The issue will be
-      // caught in the shrink-to-result later anyway.
-      if (IsSigned && !AllSigned)
-        ++MaxBits;
-
-      LHS = APSInt(IsSigned ? LHS.sextOrSelf(MaxBits) : LHS.zextOrSelf(MaxBits),
-                   !IsSigned);
-      RHS = APSInt(IsSigned ? RHS.sextOrSelf(MaxBits) : RHS.zextOrSelf(MaxBits),
-                   !IsSigned);
-      Result = APSInt(MaxBits, !IsSigned);
-    }
-
-    // Find largest int.
-    switch (BuiltinOp) {
-    default:
-      llvm_unreachable("Invalid value for BuiltinOp");
-    case Builtin::BI__builtin_add_overflow:
-    case Builtin::BI__builtin_sadd_overflow:
-    case Builtin::BI__builtin_saddl_overflow:
-    case Builtin::BI__builtin_saddll_overflow:
-    case Builtin::BI__builtin_uadd_overflow:
-    case Builtin::BI__builtin_uaddl_overflow:
-    case Builtin::BI__builtin_uaddll_overflow:
-      Result = LHS.isSigned() ? LHS.sadd_ov(RHS, DidOverflow)
-                              : LHS.uadd_ov(RHS, DidOverflow);
-      break;
-    case Builtin::BI__builtin_sub_overflow:
-    case Builtin::BI__builtin_ssub_overflow:
-    case Builtin::BI__builtin_ssubl_overflow:
-    case Builtin::BI__builtin_ssubll_overflow:
-    case Builtin::BI__builtin_usub_overflow:
-    case Builtin::BI__builtin_usubl_overflow:
-    case Builtin::BI__builtin_usubll_overflow:
-      Result = LHS.isSigned() ? LHS.ssub_ov(RHS, DidOverflow)
-                              : LHS.usub_ov(RHS, DidOverflow);
-      break;
-    case Builtin::BI__builtin_mul_overflow:
-    case Builtin::BI__builtin_smul_overflow:
-    case Builtin::BI__builtin_smull_overflow:
-    case Builtin::BI__builtin_smulll_overflow:
-    case Builtin::BI__builtin_umul_overflow:
-    case Builtin::BI__builtin_umull_overflow:
-    case Builtin::BI__builtin_umulll_overflow:
-      Result = LHS.isSigned() ? LHS.smul_ov(RHS, DidOverflow)
-                              : LHS.umul_ov(RHS, DidOverflow);
-      break;
-    }
-
-    // In the case where multiple sizes are allowed, truncate and see if
-    // the values are the same.
-    if (BuiltinOp == Builtin::BI__builtin_add_overflow ||
-        BuiltinOp == Builtin::BI__builtin_sub_overflow ||
-        BuiltinOp == Builtin::BI__builtin_mul_overflow) {
-      // APSInt doesn't have a TruncOrSelf, so we use extOrTrunc instead,
-      // since it will give us the behavior of a TruncOrSelf in the case where
-      // its parameter <= its size.  We previously set Result to be at least the
-      // type-size of the result, so getTypeSize(ResultType) <= Result.BitWidth
-      // will work exactly like TruncOrSelf.
-      APSInt Temp = Result.extOrTrunc(Info.Ctx.getTypeSize(ResultType));
-      Temp.setIsSigned(ResultType->isSignedIntegerOrEnumerationType());
-
-      if (!APSInt::isSameValue(Temp, Result))
-        DidOverflow = true;
-      Result = Temp;
-    }
-
-    APValue APV{Result};
-    if (!handleAssignment(Info, E, ResultLValue, ResultType, APV))
-      return false;
-    return Success(DidOverflow, E);
-  }
-  }
-}
-
-/// Determine whether this is a pointer past the end of the complete
-/// object referred to by the lvalue.
-static bool isOnePastTheEndOfCompleteObject(const ASTContext &Ctx,
-                                            const LValue &LV) {
-  // A null pointer can be viewed as being "past the end" but we don't
-  // choose to look at it that way here.
-  if (!LV.getLValueBase())
-    return false;
-
-  // If the designator is valid and refers to a subobject, we're not pointing
-  // past the end.
-  if (!LV.getLValueDesignator().Invalid &&
-      !LV.getLValueDesignator().isOnePastTheEnd())
-    return false;
-
-  // A pointer to an incomplete type might be past-the-end if the type's size is
-  // zero.  We cannot tell because the type is incomplete.
-  QualType Ty = getType(LV.getLValueBase());
-  if (Ty->isIncompleteType())
-    return true;
-
-  // We're a past-the-end pointer if we point to the byte after the object,
-  // no matter what our type or path is.
-  auto Size = Ctx.getTypeSizeInChars(Ty);
-  return LV.getLValueOffset() == Size;
-}
-
-namespace {
-
-/// Data recursive integer evaluator of certain binary operators.
-///
-/// We use a data recursive algorithm for binary operators so that we are able
-/// to handle extreme cases of chained binary operators without causing stack
-/// overflow.
-class DataRecursiveIntBinOpEvaluator {
-  struct EvalResult {
-    APValue Val;
-    bool Failed;
-
-    EvalResult() : Failed(false) { }
-
-    void swap(EvalResult &RHS) {
-      Val.swap(RHS.Val);
-      Failed = RHS.Failed;
-      RHS.Failed = false;
-    }
-  };
-
-  struct Job {
-    const Expr *E;
-    EvalResult LHSResult; // meaningful only for binary operator expression.
-    enum { AnyExprKind, BinOpKind, BinOpVisitedLHSKind } Kind;
-
-    Job() = default;
-    Job(Job &&) = default;
-
-    void startSpeculativeEval(EvalInfo &Info) {
-      SpecEvalRAII = SpeculativeEvaluationRAII(Info);
-    }
-
-  private:
-    SpeculativeEvaluationRAII SpecEvalRAII;
-  };
-
-  SmallVector<Job, 16> Queue;
-
-  IntExprEvaluator &IntEval;
-  EvalInfo &Info;
-  APValue &FinalResult;
-
-public:
-  DataRecursiveIntBinOpEvaluator(IntExprEvaluator &IntEval, APValue &Result)
-    : IntEval(IntEval), Info(IntEval.getEvalInfo()), FinalResult(Result) { }
-
-  /// True if \param E is a binary operator that we are going to handle
-  /// data recursively.
-  /// We handle binary operators that are comma, logical, or that have operands
-  /// with integral or enumeration type.
-  static bool shouldEnqueue(const BinaryOperator *E) {
-    return E->getOpcode() == BO_Comma || E->isLogicalOp() ||
-           (E->isRValue() && E->getType()->isIntegralOrEnumerationType() &&
-            E->getLHS()->getType()->isIntegralOrEnumerationType() &&
-            E->getRHS()->getType()->isIntegralOrEnumerationType());
-  }
-
-  bool Traverse(const BinaryOperator *E) {
-    enqueue(E);
-    EvalResult PrevResult;
-    while (!Queue.empty())
-      process(PrevResult);
-
-    if (PrevResult.Failed) return false;
-
-    FinalResult.swap(PrevResult.Val);
-    return true;
-  }
-
-private:
-  bool Success(uint64_t Value, const Expr *E, APValue &Result) {
-    return IntEval.Success(Value, E, Result);
-  }
-  bool Success(const APSInt &Value, const Expr *E, APValue &Result) {
-    return IntEval.Success(Value, E, Result);
-  }
-  bool Error(const Expr *E) {
-    return IntEval.Error(E);
-  }
-  bool Error(const Expr *E, diag::kind D) {
-    return IntEval.Error(E, D);
-  }
-
-  OptionalDiagnostic CCEDiag(const Expr *E, diag::kind D) {
-    return Info.CCEDiag(E, D);
-  }
-
-  // Returns true if visiting the RHS is necessary, false otherwise.
-  bool VisitBinOpLHSOnly(EvalResult &LHSResult, const BinaryOperator *E,
-                         bool &SuppressRHSDiags);
-
-  bool VisitBinOp(const EvalResult &LHSResult, const EvalResult &RHSResult,
-                  const BinaryOperator *E, APValue &Result);
-
-  void EvaluateExpr(const Expr *E, EvalResult &Result) {
-    Result.Failed = !Evaluate(Result.Val, Info, E);
-    if (Result.Failed)
-      Result.Val = APValue();
-  }
-
-  void process(EvalResult &Result);
-
-  void enqueue(const Expr *E) {
-    E = E->IgnoreParens();
-    Queue.resize(Queue.size()+1);
-    Queue.back().E = E;
-    Queue.back().Kind = Job::AnyExprKind;
-  }
-};
-
-}
-
-bool DataRecursiveIntBinOpEvaluator::
-       VisitBinOpLHSOnly(EvalResult &LHSResult, const BinaryOperator *E,
-                         bool &SuppressRHSDiags) {
-  if (E->getOpcode() == BO_Comma) {
-    // Ignore LHS but note if we could not evaluate it.
-    if (LHSResult.Failed)
-      return Info.noteSideEffect();
-    return true;
-  }
-
-  if (E->isLogicalOp()) {
-    bool LHSAsBool;
-    if (!LHSResult.Failed && HandleConversionToBool(LHSResult.Val, LHSAsBool)) {
-      // We were able to evaluate the LHS, see if we can get away with not
-      // evaluating the RHS: 0 && X -> 0, 1 || X -> 1
-      if (LHSAsBool == (E->getOpcode() == BO_LOr)) {
-        Success(LHSAsBool, E, LHSResult.Val);
-        return false; // Ignore RHS
-      }
-    } else {
-      LHSResult.Failed = true;
-
-      // Since we weren't able to evaluate the left hand side, it
-      // might have had side effects.
-      if (!Info.noteSideEffect())
-        return false;
-
-      // We can't evaluate the LHS; however, sometimes the result
-      // is determined by the RHS: X && 0 -> 0, X || 1 -> 1.
-      // Don't ignore RHS and suppress diagnostics from this arm.
-      SuppressRHSDiags = true;
-    }
-
-    return true;
-  }
-
-  assert(E->getLHS()->getType()->isIntegralOrEnumerationType() &&
-         E->getRHS()->getType()->isIntegralOrEnumerationType());
-
-  if (LHSResult.Failed && !Info.noteFailure())
-    return false; // Ignore RHS;
-
-  return true;
-}
-
-static void addOrSubLValueAsInteger(APValue &LVal, const APSInt &Index,
-                                    bool IsSub) {
-  // Compute the new offset in the appropriate width, wrapping at 64 bits.
-  // FIXME: When compiling for a 32-bit target, we should use 32-bit
-  // offsets.
-  assert(!LVal.hasLValuePath() && "have designator for integer lvalue");
-  CharUnits &Offset = LVal.getLValueOffset();
-  uint64_t Offset64 = Offset.getQuantity();
-  uint64_t Index64 = Index.extOrTrunc(64).getZExtValue();
-  Offset = CharUnits::fromQuantity(IsSub ? Offset64 - Index64
-                                         : Offset64 + Index64);
-}
-
-bool DataRecursiveIntBinOpEvaluator::
-       VisitBinOp(const EvalResult &LHSResult, const EvalResult &RHSResult,
-                  const BinaryOperator *E, APValue &Result) {
-  if (E->getOpcode() == BO_Comma) {
-    if (RHSResult.Failed)
-      return false;
-    Result = RHSResult.Val;
-    return true;
-  }
-
-  if (E->isLogicalOp()) {
-    bool lhsResult, rhsResult;
-    bool LHSIsOK = HandleConversionToBool(LHSResult.Val, lhsResult);
-    bool RHSIsOK = HandleConversionToBool(RHSResult.Val, rhsResult);
-
-    if (LHSIsOK) {
-      if (RHSIsOK) {
-        if (E->getOpcode() == BO_LOr)
-          return Success(lhsResult || rhsResult, E, Result);
-        else
-          return Success(lhsResult && rhsResult, E, Result);
-      }
-    } else {
-      if (RHSIsOK) {
-        // We can't evaluate the LHS; however, sometimes the result
-        // is determined by the RHS: X && 0 -> 0, X || 1 -> 1.
-        if (rhsResult == (E->getOpcode() == BO_LOr))
-          return Success(rhsResult, E, Result);
-      }
-    }
-
-    return false;
-  }
-
-  assert(E->getLHS()->getType()->isIntegralOrEnumerationType() &&
-         E->getRHS()->getType()->isIntegralOrEnumerationType());
-
-  if (LHSResult.Failed || RHSResult.Failed)
-    return false;
-
-  const APValue &LHSVal = LHSResult.Val;
-  const APValue &RHSVal = RHSResult.Val;
-
-  // Handle cases like (unsigned long)&a + 4.
-  if (E->isAdditiveOp() && LHSVal.isLValue() && RHSVal.isInt()) {
-    Result = LHSVal;
-    addOrSubLValueAsInteger(Result, RHSVal.getInt(), E->getOpcode() == BO_Sub);
-    return true;
-  }
-
-  // Handle cases like 4 + (unsigned long)&a
-  if (E->getOpcode() == BO_Add &&
-      RHSVal.isLValue() && LHSVal.isInt()) {
-    Result = RHSVal;
-    addOrSubLValueAsInteger(Result, LHSVal.getInt(), /*IsSub*/false);
-    return true;
-  }
-
-  if (E->getOpcode() == BO_Sub && LHSVal.isLValue() && RHSVal.isLValue()) {
-    // Handle (intptr_t)&&A - (intptr_t)&&B.
-    if (!LHSVal.getLValueOffset().isZero() ||
-        !RHSVal.getLValueOffset().isZero())
-      return false;
-    const Expr *LHSExpr = LHSVal.getLValueBase().dyn_cast<const Expr*>();
-    const Expr *RHSExpr = RHSVal.getLValueBase().dyn_cast<const Expr*>();
-    if (!LHSExpr || !RHSExpr)
-      return false;
-    const AddrLabelExpr *LHSAddrExpr = dyn_cast<AddrLabelExpr>(LHSExpr);
-    const AddrLabelExpr *RHSAddrExpr = dyn_cast<AddrLabelExpr>(RHSExpr);
-    if (!LHSAddrExpr || !RHSAddrExpr)
-      return false;
-    // Make sure both labels come from the same function.
-    if (LHSAddrExpr->getLabel()->getDeclContext() !=
-        RHSAddrExpr->getLabel()->getDeclContext())
-      return false;
-    Result = APValue(LHSAddrExpr, RHSAddrExpr);
-    return true;
-  }
-
-  // All the remaining cases expect both operands to be an integer
-  if (!LHSVal.isInt() || !RHSVal.isInt())
-    return Error(E);
-
-  // Set up the width and signedness manually, in case it can't be deduced
-  // from the operation we're performing.
-  // FIXME: Don't do this in the cases where we can deduce it.
-  APSInt Value(Info.Ctx.getIntWidth(E->getType()),
-               E->getType()->isUnsignedIntegerOrEnumerationType());
-  if (!handleIntIntBinOp(Info, E, LHSVal.getInt(), E->getOpcode(),
-                         RHSVal.getInt(), Value))
-    return false;
-  return Success(Value, E, Result);
-}
-
-void DataRecursiveIntBinOpEvaluator::process(EvalResult &Result) {
-  Job &job = Queue.back();
-
-  switch (job.Kind) {
-    case Job::AnyExprKind: {
-      if (const BinaryOperator *Bop = dyn_cast<BinaryOperator>(job.E)) {
-        if (shouldEnqueue(Bop)) {
-          job.Kind = Job::BinOpKind;
-          enqueue(Bop->getLHS());
-          return;
-        }
-      }
-
-      EvaluateExpr(job.E, Result);
-      Queue.pop_back();
-      return;
-    }
-
-    case Job::BinOpKind: {
-      const BinaryOperator *Bop = cast<BinaryOperator>(job.E);
-      bool SuppressRHSDiags = false;
-      if (!VisitBinOpLHSOnly(Result, Bop, SuppressRHSDiags)) {
-        Queue.pop_back();
-        return;
-      }
-      if (SuppressRHSDiags)
-        job.startSpeculativeEval(Info);
-      job.LHSResult.swap(Result);
-      job.Kind = Job::BinOpVisitedLHSKind;
-      enqueue(Bop->getRHS());
-      return;
-    }
-
-    case Job::BinOpVisitedLHSKind: {
-      const BinaryOperator *Bop = cast<BinaryOperator>(job.E);
-      EvalResult RHS;
-      RHS.swap(Result);
-      Result.Failed = !VisitBinOp(job.LHSResult, RHS, Bop, Result.Val);
-      Queue.pop_back();
-      return;
-    }
-  }
-
-  llvm_unreachable("Invalid Job::Kind!");
-}
-
-namespace {
-/// Used when we determine that we should fail, but can keep evaluating prior to
-/// noting that we had a failure.
-class DelayedNoteFailureRAII {
-  EvalInfo &Info;
-  bool NoteFailure;
-
-public:
-  DelayedNoteFailureRAII(EvalInfo &Info, bool NoteFailure = true)
-      : Info(Info), NoteFailure(NoteFailure) {}
-  ~DelayedNoteFailureRAII() {
-    if (NoteFailure) {
-      bool ContinueAfterFailure = Info.noteFailure();
-      (void)ContinueAfterFailure;
-      assert(ContinueAfterFailure &&
-             "Shouldn't have kept evaluating on failure.");
-    }
-  }
-};
-}
-
-template <class SuccessCB, class AfterCB>
-static bool
-EvaluateComparisonBinaryOperator(EvalInfo &Info, const BinaryOperator *E,
-                                 SuccessCB &&Success, AfterCB &&DoAfter) {
-  assert(E->isComparisonOp() && "expected comparison operator");
-  assert((E->getOpcode() == BO_Cmp ||
-          E->getType()->isIntegralOrEnumerationType()) &&
-         "unsupported binary expression evaluation");
-  auto Error = [&](const Expr *E) {
-    Info.FFDiag(E, diag::note_invalid_subexpr_in_const_expr);
-    return false;
-  };
-
-  using CCR = ComparisonCategoryResult;
-  bool IsRelational = E->isRelationalOp();
-  bool IsEquality = E->isEqualityOp();
-  if (E->getOpcode() == BO_Cmp) {
-    const ComparisonCategoryInfo &CmpInfo =
-        Info.Ctx.CompCategories.getInfoForType(E->getType());
-    IsRelational = CmpInfo.isOrdered();
-    IsEquality = CmpInfo.isEquality();
-  }
-
-  QualType LHSTy = E->getLHS()->getType();
-  QualType RHSTy = E->getRHS()->getType();
-
-  if (LHSTy->isIntegralOrEnumerationType() &&
-      RHSTy->isIntegralOrEnumerationType()) {
-    APSInt LHS, RHS;
-    bool LHSOK = EvaluateInteger(E->getLHS(), LHS, Info);
-    if (!LHSOK && !Info.noteFailure())
-      return false;
-    if (!EvaluateInteger(E->getRHS(), RHS, Info) || !LHSOK)
-      return false;
-    if (LHS < RHS)
-      return Success(CCR::Less, E);
-    if (LHS > RHS)
-      return Success(CCR::Greater, E);
-    return Success(CCR::Equal, E);
-  }
-
-  if (LHSTy->isAnyComplexType() || RHSTy->isAnyComplexType()) {
-    ComplexValue LHS, RHS;
-    bool LHSOK;
-    if (E->isAssignmentOp()) {
-      LValue LV;
-      EvaluateLValue(E->getLHS(), LV, Info);
-      LHSOK = false;
-    } else if (LHSTy->isRealFloatingType()) {
-      LHSOK = EvaluateFloat(E->getLHS(), LHS.FloatReal, Info);
-      if (LHSOK) {
-        LHS.makeComplexFloat();
-        LHS.FloatImag = APFloat(LHS.FloatReal.getSemantics());
-      }
-    } else {
-      LHSOK = EvaluateComplex(E->getLHS(), LHS, Info);
-    }
-    if (!LHSOK && !Info.noteFailure())
-      return false;
-
-    if (E->getRHS()->getType()->isRealFloatingType()) {
-      if (!EvaluateFloat(E->getRHS(), RHS.FloatReal, Info) || !LHSOK)
-        return false;
-      RHS.makeComplexFloat();
-      RHS.FloatImag = APFloat(RHS.FloatReal.getSemantics());
-    } else if (!EvaluateComplex(E->getRHS(), RHS, Info) || !LHSOK)
-      return false;
-
-    if (LHS.isComplexFloat()) {
-      APFloat::cmpResult CR_r =
-        LHS.getComplexFloatReal().compare(RHS.getComplexFloatReal());
-      APFloat::cmpResult CR_i =
-        LHS.getComplexFloatImag().compare(RHS.getComplexFloatImag());
-      bool IsEqual = CR_r == APFloat::cmpEqual && CR_i == APFloat::cmpEqual;
-      return Success(IsEqual ? CCR::Equal : CCR::Nonequal, E);
-    } else {
-      assert(IsEquality && "invalid complex comparison");
-      bool IsEqual = LHS.getComplexIntReal() == RHS.getComplexIntReal() &&
-                     LHS.getComplexIntImag() == RHS.getComplexIntImag();
-      return Success(IsEqual ? CCR::Equal : CCR::Nonequal, E);
-    }
-  }
-
-  if (LHSTy->isRealFloatingType() &&
-      RHSTy->isRealFloatingType()) {
-    APFloat RHS(0.0), LHS(0.0);
-
-    bool LHSOK = EvaluateFloat(E->getRHS(), RHS, Info);
-    if (!LHSOK && !Info.noteFailure())
-      return false;
-
-    if (!EvaluateFloat(E->getLHS(), LHS, Info) || !LHSOK)
-      return false;
-
-    assert(E->isComparisonOp() && "Invalid binary operator!");
-    auto GetCmpRes = [&]() {
-      switch (LHS.compare(RHS)) {
-      case APFloat::cmpEqual:
-        return CCR::Equal;
-      case APFloat::cmpLessThan:
-        return CCR::Less;
-      case APFloat::cmpGreaterThan:
-        return CCR::Greater;
-      case APFloat::cmpUnordered:
-        return CCR::Unordered;
-      }
-      llvm_unreachable("Unrecognised APFloat::cmpResult enum");
-    };
-    return Success(GetCmpRes(), E);
-  }
-
-  if (LHSTy->isPointerType() && RHSTy->isPointerType()) {
-    LValue LHSValue, RHSValue;
-
-    bool LHSOK = EvaluatePointer(E->getLHS(), LHSValue, Info);
-    if (!LHSOK && !Info.noteFailure())
-      return false;
-
-    if (!EvaluatePointer(E->getRHS(), RHSValue, Info) || !LHSOK)
-      return false;
-
-    // Reject differing bases from the normal codepath; we special-case
-    // comparisons to null.
-    if (!HasSameBase(LHSValue, RHSValue)) {
-      // Inequalities and subtractions between unrelated pointers have
-      // unspecified or undefined behavior.
-      if (!IsEquality)
-        return Error(E);
-      // A constant address may compare equal to the address of a symbol.
-      // The one exception is that address of an object cannot compare equal
-      // to a null pointer constant.
-      if ((!LHSValue.Base && !LHSValue.Offset.isZero()) ||
-          (!RHSValue.Base && !RHSValue.Offset.isZero()))
-        return Error(E);
-      // It's implementation-defined whether distinct literals will have
-      // distinct addresses. In clang, the result of such a comparison is
-      // unspecified, so it is not a constant expression. However, we do know
-      // that the address of a literal will be non-null.
-      if ((IsLiteralLValue(LHSValue) || IsLiteralLValue(RHSValue)) &&
-          LHSValue.Base && RHSValue.Base)
-        return Error(E);
-      // We can't tell whether weak symbols will end up pointing to the same
-      // object.
-      if (IsWeakLValue(LHSValue) || IsWeakLValue(RHSValue))
-        return Error(E);
-      // We can't compare the address of the start of one object with the
-      // past-the-end address of another object, per C++ DR1652.
-      if ((LHSValue.Base && LHSValue.Offset.isZero() &&
-           isOnePastTheEndOfCompleteObject(Info.Ctx, RHSValue)) ||
-          (RHSValue.Base && RHSValue.Offset.isZero() &&
-           isOnePastTheEndOfCompleteObject(Info.Ctx, LHSValue)))
-        return Error(E);
-      // We can't tell whether an object is at the same address as another
-      // zero sized object.
-      if ((RHSValue.Base && isZeroSized(LHSValue)) ||
-          (LHSValue.Base && isZeroSized(RHSValue)))
-        return Error(E);
-      return Success(CCR::Nonequal, E);
-    }
-
-    const CharUnits &LHSOffset = LHSValue.getLValueOffset();
-    const CharUnits &RHSOffset = RHSValue.getLValueOffset();
-
-    SubobjectDesignator &LHSDesignator = LHSValue.getLValueDesignator();
-    SubobjectDesignator &RHSDesignator = RHSValue.getLValueDesignator();
-
-    // C++11 [expr.rel]p3:
-    //   Pointers to void (after pointer conversions) can be compared, with a
-    //   result defined as follows: If both pointers represent the same
-    //   address or are both the null pointer value, the result is true if the
-    //   operator is <= or >= and false otherwise; otherwise the result is
-    //   unspecified.
-    // We interpret this as applying to pointers to *cv* void.
-    if (LHSTy->isVoidPointerType() && LHSOffset != RHSOffset && IsRelational)
-      Info.CCEDiag(E, diag::note_constexpr_void_comparison);
-
-    // C++11 [expr.rel]p2:
-    // - If two pointers point to non-static data members of the same object,
-    //   or to subobjects or array elements fo such members, recursively, the
-    //   pointer to the later declared member compares greater provided the
-    //   two members have the same access control and provided their class is
-    //   not a union.
-    //   [...]
-    // - Otherwise pointer comparisons are unspecified.
-    if (!LHSDesignator.Invalid && !RHSDesignator.Invalid && IsRelational) {
-      bool WasArrayIndex;
-      unsigned Mismatch = FindDesignatorMismatch(
-          getType(LHSValue.Base), LHSDesignator, RHSDesignator, WasArrayIndex);
-      // At the point where the designators diverge, the comparison has a
-      // specified value if:
-      //  - we are comparing array indices
-      //  - we are comparing fields of a union, or fields with the same access
-      // Otherwise, the result is unspecified and thus the comparison is not a
-      // constant expression.
-      if (!WasArrayIndex && Mismatch < LHSDesignator.Entries.size() &&
-          Mismatch < RHSDesignator.Entries.size()) {
-        const FieldDecl *LF = getAsField(LHSDesignator.Entries[Mismatch]);
-        const FieldDecl *RF = getAsField(RHSDesignator.Entries[Mismatch]);
-        if (!LF && !RF)
-          Info.CCEDiag(E, diag::note_constexpr_pointer_comparison_base_classes);
-        else if (!LF)
-          Info.CCEDiag(E, diag::note_constexpr_pointer_comparison_base_field)
-              << getAsBaseClass(LHSDesignator.Entries[Mismatch])
-              << RF->getParent() << RF;
-        else if (!RF)
-          Info.CCEDiag(E, diag::note_constexpr_pointer_comparison_base_field)
-              << getAsBaseClass(RHSDesignator.Entries[Mismatch])
-              << LF->getParent() << LF;
-        else if (!LF->getParent()->isUnion() &&
-                 LF->getAccess() != RF->getAccess())
-          Info.CCEDiag(E,
-                       diag::note_constexpr_pointer_comparison_differing_access)
-              << LF << LF->getAccess() << RF << RF->getAccess()
-              << LF->getParent();
-      }
-    }
-
-    // The comparison here must be unsigned, and performed with the same
-    // width as the pointer.
-    unsigned PtrSize = Info.Ctx.getTypeSize(LHSTy);
-    uint64_t CompareLHS = LHSOffset.getQuantity();
-    uint64_t CompareRHS = RHSOffset.getQuantity();
-    assert(PtrSize <= 64 && "Unexpected pointer width");
-    uint64_t Mask = ~0ULL >> (64 - PtrSize);
-    CompareLHS &= Mask;
-    CompareRHS &= Mask;
-
-    // If there is a base and this is a relational operator, we can only
-    // compare pointers within the object in question; otherwise, the result
-    // depends on where the object is located in memory.
-    if (!LHSValue.Base.isNull() && IsRelational) {
-      QualType BaseTy = getType(LHSValue.Base);
-      if (BaseTy->isIncompleteType())
-        return Error(E);
-      CharUnits Size = Info.Ctx.getTypeSizeInChars(BaseTy);
-      uint64_t OffsetLimit = Size.getQuantity();
-      if (CompareLHS > OffsetLimit || CompareRHS > OffsetLimit)
-        return Error(E);
-    }
-
-    if (CompareLHS < CompareRHS)
-      return Success(CCR::Less, E);
-    if (CompareLHS > CompareRHS)
-      return Success(CCR::Greater, E);
-    return Success(CCR::Equal, E);
-  }
-
-  if (LHSTy->isMemberPointerType()) {
-    assert(IsEquality && "unexpected member pointer operation");
-    assert(RHSTy->isMemberPointerType() && "invalid comparison");
-
-    MemberPtr LHSValue, RHSValue;
-
-    bool LHSOK = EvaluateMemberPointer(E->getLHS(), LHSValue, Info);
-    if (!LHSOK && !Info.noteFailure())
-      return false;
-
-    if (!EvaluateMemberPointer(E->getRHS(), RHSValue, Info) || !LHSOK)
-      return false;
-
-    // C++11 [expr.eq]p2:
-    //   If both operands are null, they compare equal. Otherwise if only one is
-    //   null, they compare unequal.
-    if (!LHSValue.getDecl() || !RHSValue.getDecl()) {
-      bool Equal = !LHSValue.getDecl() && !RHSValue.getDecl();
-      return Success(Equal ? CCR::Equal : CCR::Nonequal, E);
-    }
-
-    //   Otherwise if either is a pointer to a virtual member function, the
-    //   result is unspecified.
-    if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(LHSValue.getDecl()))
-      if (MD->isVirtual())
-        Info.CCEDiag(E, diag::note_constexpr_compare_virtual_mem_ptr) << MD;
-    if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(RHSValue.getDecl()))
-      if (MD->isVirtual())
-        Info.CCEDiag(E, diag::note_constexpr_compare_virtual_mem_ptr) << MD;
-
-    //   Otherwise they compare equal if and only if they would refer to the
-    //   same member of the same most derived object or the same subobject if
-    //   they were dereferenced with a hypothetical object of the associated
-    //   class type.
-    bool Equal = LHSValue == RHSValue;
-    return Success(Equal ? CCR::Equal : CCR::Nonequal, E);
-  }
-
-  if (LHSTy->isNullPtrType()) {
-    assert(E->isComparisonOp() && "unexpected nullptr operation");
-    assert(RHSTy->isNullPtrType() && "missing pointer conversion");
-    // C++11 [expr.rel]p4, [expr.eq]p3: If two operands of type std::nullptr_t
-    // are compared, the result is true of the operator is <=, >= or ==, and
-    // false otherwise.
-    return Success(CCR::Equal, E);
-  }
-
-  return DoAfter();
-}
-
-bool RecordExprEvaluator::VisitBinCmp(const BinaryOperator *E) {
-  if (!CheckLiteralType(Info, E))
-    return false;
-
-  auto OnSuccess = [&](ComparisonCategoryResult ResKind,
-                       const BinaryOperator *E) {
-    // Evaluation succeeded. Lookup the information for the comparison category
-    // type and fetch the VarDecl for the result.
-    const ComparisonCategoryInfo &CmpInfo =
-        Info.Ctx.CompCategories.getInfoForType(E->getType());
-    const VarDecl *VD =
-        CmpInfo.getValueInfo(CmpInfo.makeWeakResult(ResKind))->VD;
-    // Check and evaluate the result as a constant expression.
-    LValue LV;
-    LV.set(VD);
-    if (!handleLValueToRValueConversion(Info, E, E->getType(), LV, Result))
-      return false;
-    return CheckConstantExpression(Info, E->getExprLoc(), E->getType(), Result);
-  };
-  return EvaluateComparisonBinaryOperator(Info, E, OnSuccess, [&]() {
-    return ExprEvaluatorBaseTy::VisitBinCmp(E);
-  });
-}
-
-bool IntExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) {
-  // We don't call noteFailure immediately because the assignment happens after
-  // we evaluate LHS and RHS.
-  if (!Info.keepEvaluatingAfterFailure() && E->isAssignmentOp())
-    return Error(E);
-
-  DelayedNoteFailureRAII MaybeNoteFailureLater(Info, E->isAssignmentOp());
-  if (DataRecursiveIntBinOpEvaluator::shouldEnqueue(E))
-    return DataRecursiveIntBinOpEvaluator(*this, Result).Traverse(E);
-
-  assert((!E->getLHS()->getType()->isIntegralOrEnumerationType() ||
-          !E->getRHS()->getType()->isIntegralOrEnumerationType()) &&
-         "DataRecursiveIntBinOpEvaluator should have handled integral types");
-
-  if (E->isComparisonOp()) {
-    // Evaluate builtin binary comparisons by evaluating them as C++2a three-way
-    // comparisons and then translating the result.
-    auto OnSuccess = [&](ComparisonCategoryResult ResKind,
-                         const BinaryOperator *E) {
-      using CCR = ComparisonCategoryResult;
-      bool IsEqual   = ResKind == CCR::Equal,
-           IsLess    = ResKind == CCR::Less,
-           IsGreater = ResKind == CCR::Greater;
-      auto Op = E->getOpcode();
-      switch (Op) {
-      default:
-        llvm_unreachable("unsupported binary operator");
-      case BO_EQ:
-      case BO_NE:
-        return Success(IsEqual == (Op == BO_EQ), E);
-      case BO_LT: return Success(IsLess, E);
-      case BO_GT: return Success(IsGreater, E);
-      case BO_LE: return Success(IsEqual || IsLess, E);
-      case BO_GE: return Success(IsEqual || IsGreater, E);
-      }
-    };
-    return EvaluateComparisonBinaryOperator(Info, E, OnSuccess, [&]() {
-      return ExprEvaluatorBaseTy::VisitBinaryOperator(E);
-    });
-  }
-
-  QualType LHSTy = E->getLHS()->getType();
-  QualType RHSTy = E->getRHS()->getType();
-
-  if (LHSTy->isPointerType() && RHSTy->isPointerType() &&
-      E->getOpcode() == BO_Sub) {
-    LValue LHSValue, RHSValue;
-
-    bool LHSOK = EvaluatePointer(E->getLHS(), LHSValue, Info);
-    if (!LHSOK && !Info.noteFailure())
-      return false;
-
-    if (!EvaluatePointer(E->getRHS(), RHSValue, Info) || !LHSOK)
-      return false;
-
-    // Reject differing bases from the normal codepath; we special-case
-    // comparisons to null.
-    if (!HasSameBase(LHSValue, RHSValue)) {
-      // Handle &&A - &&B.
-      if (!LHSValue.Offset.isZero() || !RHSValue.Offset.isZero())
-        return Error(E);
-      const Expr *LHSExpr = LHSValue.Base.dyn_cast<const Expr *>();
-      const Expr *RHSExpr = RHSValue.Base.dyn_cast<const Expr *>();
-      if (!LHSExpr || !RHSExpr)
-        return Error(E);
-      const AddrLabelExpr *LHSAddrExpr = dyn_cast<AddrLabelExpr>(LHSExpr);
-      const AddrLabelExpr *RHSAddrExpr = dyn_cast<AddrLabelExpr>(RHSExpr);
-      if (!LHSAddrExpr || !RHSAddrExpr)
-        return Error(E);
-      // Make sure both labels come from the same function.
-      if (LHSAddrExpr->getLabel()->getDeclContext() !=
-          RHSAddrExpr->getLabel()->getDeclContext())
-        return Error(E);
-      return Success(APValue(LHSAddrExpr, RHSAddrExpr), E);
-    }
-    const CharUnits &LHSOffset = LHSValue.getLValueOffset();
-    const CharUnits &RHSOffset = RHSValue.getLValueOffset();
-
-    SubobjectDesignator &LHSDesignator = LHSValue.getLValueDesignator();
-    SubobjectDesignator &RHSDesignator = RHSValue.getLValueDesignator();
-
-    // C++11 [expr.add]p6:
-    //   Unless both pointers point to elements of the same array object, or
-    //   one past the last element of the array object, the behavior is
-    //   undefined.
-    if (!LHSDesignator.Invalid && !RHSDesignator.Invalid &&
-        !AreElementsOfSameArray(getType(LHSValue.Base), LHSDesignator,
-                                RHSDesignator))
-      Info.CCEDiag(E, diag::note_constexpr_pointer_subtraction_not_same_array);
-
-    QualType Type = E->getLHS()->getType();
-    QualType ElementType = Type->getAs<PointerType>()->getPointeeType();
-
-    CharUnits ElementSize;
-    if (!HandleSizeof(Info, E->getExprLoc(), ElementType, ElementSize))
-      return false;
-
-    // As an extension, a type may have zero size (empty struct or union in
-    // C, array of zero length). Pointer subtraction in such cases has
-    // undefined behavior, so is not constant.
-    if (ElementSize.isZero()) {
-      Info.FFDiag(E, diag::note_constexpr_pointer_subtraction_zero_size)
-          << ElementType;
-      return false;
-    }
-
-    // FIXME: LLVM and GCC both compute LHSOffset - RHSOffset at runtime,
-    // and produce incorrect results when it overflows. Such behavior
-    // appears to be non-conforming, but is common, so perhaps we should
-    // assume the standard intended for such cases to be undefined behavior
-    // and check for them.
-
-    // Compute (LHSOffset - RHSOffset) / Size carefully, checking for
-    // overflow in the final conversion to ptrdiff_t.
-    APSInt LHS(llvm::APInt(65, (int64_t)LHSOffset.getQuantity(), true), false);
-    APSInt RHS(llvm::APInt(65, (int64_t)RHSOffset.getQuantity(), true), false);
-    APSInt ElemSize(llvm::APInt(65, (int64_t)ElementSize.getQuantity(), true),
-                    false);
-    APSInt TrueResult = (LHS - RHS) / ElemSize;
-    APSInt Result = TrueResult.trunc(Info.Ctx.getIntWidth(E->getType()));
-
-    if (Result.extend(65) != TrueResult &&
-        !HandleOverflow(Info, E, TrueResult, E->getType()))
-      return false;
-    return Success(Result, E);
-  }
-
-  return ExprEvaluatorBaseTy::VisitBinaryOperator(E);
-}
-
-/// VisitUnaryExprOrTypeTraitExpr - Evaluate a sizeof, alignof or vec_step with
-/// a result as the expression's type.
-bool IntExprEvaluator::VisitUnaryExprOrTypeTraitExpr(
-                                    const UnaryExprOrTypeTraitExpr *E) {
-  switch(E->getKind()) {
-  case UETT_PreferredAlignOf:
-  case UETT_AlignOf: {
-    if (E->isArgumentType())
-      return Success(GetAlignOfType(Info, E->getArgumentType(), E->getKind()),
-                     E);
-    else
-      return Success(GetAlignOfExpr(Info, E->getArgumentExpr(), E->getKind()),
-                     E);
-  }
-
-  case UETT_VecStep: {
-    QualType Ty = E->getTypeOfArgument();
-
-    if (Ty->isVectorType()) {
-      unsigned n = Ty->castAs<VectorType>()->getNumElements();
-
-      // The vec_step built-in functions that take a 3-component
-      // vector return 4. (OpenCL 1.1 spec 6.11.12)
-      if (n == 3)
-        n = 4;
-
-      return Success(n, E);
-    } else
-      return Success(1, E);
-  }
-
-  case UETT_SizeOf: {
-    QualType SrcTy = E->getTypeOfArgument();
-    // C++ [expr.sizeof]p2: "When applied to a reference or a reference type,
-    //   the result is the size of the referenced type."
-    if (const ReferenceType *Ref = SrcTy->getAs<ReferenceType>())
-      SrcTy = Ref->getPointeeType();
-
-    CharUnits Sizeof;
-    if (!HandleSizeof(Info, E->getExprLoc(), SrcTy, Sizeof))
-      return false;
-    return Success(Sizeof, E);
-  }
-  case UETT_OpenMPRequiredSimdAlign:
-    assert(E->isArgumentType());
-    return Success(
-        Info.Ctx.toCharUnitsFromBits(
-                    Info.Ctx.getOpenMPDefaultSimdAlign(E->getArgumentType()))
-            .getQuantity(),
-        E);
-  }
-
-  llvm_unreachable("unknown expr/type trait");
-}
-
-bool IntExprEvaluator::VisitOffsetOfExpr(const OffsetOfExpr *OOE) {
-  CharUnits Result;
-  unsigned n = OOE->getNumComponents();
-  if (n == 0)
-    return Error(OOE);
-  QualType CurrentType = OOE->getTypeSourceInfo()->getType();
-  for (unsigned i = 0; i != n; ++i) {
-    OffsetOfNode ON = OOE->getComponent(i);
-    switch (ON.getKind()) {
-    case OffsetOfNode::Array: {
-      const Expr *Idx = OOE->getIndexExpr(ON.getArrayExprIndex());
-      APSInt IdxResult;
-      if (!EvaluateInteger(Idx, IdxResult, Info))
-        return false;
-      const ArrayType *AT = Info.Ctx.getAsArrayType(CurrentType);
-      if (!AT)
-        return Error(OOE);
-      CurrentType = AT->getElementType();
-      CharUnits ElementSize = Info.Ctx.getTypeSizeInChars(CurrentType);
-      Result += IdxResult.getSExtValue() * ElementSize;
-      break;
-    }
-
-    case OffsetOfNode::Field: {
-      FieldDecl *MemberDecl = ON.getField();
-      const RecordType *RT = CurrentType->getAs<RecordType>();
-      if (!RT)
-        return Error(OOE);
-      RecordDecl *RD = RT->getDecl();
-      if (RD->isInvalidDecl()) return false;
-      const ASTRecordLayout &RL = Info.Ctx.getASTRecordLayout(RD);
-      unsigned i = MemberDecl->getFieldIndex();
-      assert(i < RL.getFieldCount() && "offsetof field in wrong type");
-      Result += Info.Ctx.toCharUnitsFromBits(RL.getFieldOffset(i));
-      CurrentType = MemberDecl->getType().getNonReferenceType();
-      break;
-    }
-
-    case OffsetOfNode::Identifier:
-      llvm_unreachable("dependent __builtin_offsetof");
-
-    case OffsetOfNode::Base: {
-      CXXBaseSpecifier *BaseSpec = ON.getBase();
-      if (BaseSpec->isVirtual())
-        return Error(OOE);
-
-      // Find the layout of the class whose base we are looking into.
-      const RecordType *RT = CurrentType->getAs<RecordType>();
-      if (!RT)
-        return Error(OOE);
-      RecordDecl *RD = RT->getDecl();
-      if (RD->isInvalidDecl()) return false;
-      const ASTRecordLayout &RL = Info.Ctx.getASTRecordLayout(RD);
-
-      // Find the base class itself.
-      CurrentType = BaseSpec->getType();
-      const RecordType *BaseRT = CurrentType->getAs<RecordType>();
-      if (!BaseRT)
-        return Error(OOE);
-
-      // Add the offset to the base.
-      Result += RL.getBaseClassOffset(cast<CXXRecordDecl>(BaseRT->getDecl()));
-      break;
-    }
-    }
-  }
-  return Success(Result, OOE);
-}
-
-bool IntExprEvaluator::VisitUnaryOperator(const UnaryOperator *E) {
-  switch (E->getOpcode()) {
-  default:
-    // Address, indirect, pre/post inc/dec, etc are not valid constant exprs.
-    // See C99 6.6p3.
-    return Error(E);
-  case UO_Extension:
-    // FIXME: Should extension allow i-c-e extension expressions in its scope?
-    // If so, we could clear the diagnostic ID.
-    return Visit(E->getSubExpr());
-  case UO_Plus:
-    // The result is just the value.
-    return Visit(E->getSubExpr());
-  case UO_Minus: {
-    if (!Visit(E->getSubExpr()))
-      return false;
-    if (!Result.isInt()) return Error(E);
-    const APSInt &Value = Result.getInt();
-    if (Value.isSigned() && Value.isMinSignedValue() && E->canOverflow() &&
-        !HandleOverflow(Info, E, -Value.extend(Value.getBitWidth() + 1),
-                        E->getType()))
-      return false;
-    return Success(-Value, E);
-  }
-  case UO_Not: {
-    if (!Visit(E->getSubExpr()))
-      return false;
-    if (!Result.isInt()) return Error(E);
-    return Success(~Result.getInt(), E);
-  }
-  case UO_LNot: {
-    bool bres;
-    if (!EvaluateAsBooleanCondition(E->getSubExpr(), bres, Info))
-      return false;
-    return Success(!bres, E);
-  }
-  }
-}
-
-/// HandleCast - This is used to evaluate implicit or explicit casts where the
-/// result type is integer.
-bool IntExprEvaluator::VisitCastExpr(const CastExpr *E) {
-  const Expr *SubExpr = E->getSubExpr();
-  QualType DestType = E->getType();
-  QualType SrcType = SubExpr->getType();
-
-  switch (E->getCastKind()) {
-  case CK_BaseToDerived:
-  case CK_DerivedToBase:
-  case CK_UncheckedDerivedToBase:
-  case CK_Dynamic:
-  case CK_ToUnion:
-  case CK_ArrayToPointerDecay:
-  case CK_FunctionToPointerDecay:
-  case CK_NullToPointer:
-  case CK_NullToMemberPointer:
-  case CK_BaseToDerivedMemberPointer:
-  case CK_DerivedToBaseMemberPointer:
-  case CK_ReinterpretMemberPointer:
-  case CK_ConstructorConversion:
-  case CK_IntegralToPointer:
-  case CK_ToVoid:
-  case CK_VectorSplat:
-  case CK_IntegralToFloating:
-  case CK_FloatingCast:
-  case CK_CPointerToObjCPointerCast:
-  case CK_BlockPointerToObjCPointerCast:
-  case CK_AnyPointerToBlockPointerCast:
-  case CK_ObjCObjectLValueCast:
-  case CK_FloatingRealToComplex:
-  case CK_FloatingComplexToReal:
-  case CK_FloatingComplexCast:
-  case CK_FloatingComplexToIntegralComplex:
-  case CK_IntegralRealToComplex:
-  case CK_IntegralComplexCast:
-  case CK_IntegralComplexToFloatingComplex:
-  case CK_BuiltinFnToFnPtr:
-  case CK_ZeroToOCLOpaqueType:
-  case CK_NonAtomicToAtomic:
-  case CK_AddressSpaceConversion:
-  case CK_IntToOCLSampler:
-  case CK_FixedPointCast:
-    llvm_unreachable("invalid cast kind for integral value");
-
-  case CK_BitCast:
-  case CK_Dependent:
-  case CK_LValueBitCast:
-  case CK_ARCProduceObject:
-  case CK_ARCConsumeObject:
-  case CK_ARCReclaimReturnedObject:
-  case CK_ARCExtendBlockObject:
-  case CK_CopyAndAutoreleaseBlockObject:
-    return Error(E);
-
-  case CK_UserDefinedConversion:
-  case CK_LValueToRValue:
-  case CK_AtomicToNonAtomic:
-  case CK_NoOp:
-    return ExprEvaluatorBaseTy::VisitCastExpr(E);
-
-  case CK_MemberPointerToBoolean:
-  case CK_PointerToBoolean:
-  case CK_IntegralToBoolean:
-  case CK_FloatingToBoolean:
-  case CK_BooleanToSignedIntegral:
-  case CK_FloatingComplexToBoolean:
-  case CK_IntegralComplexToBoolean: {
-    bool BoolResult;
-    if (!EvaluateAsBooleanCondition(SubExpr, BoolResult, Info))
-      return false;
-    uint64_t IntResult = BoolResult;
-    if (BoolResult && E->getCastKind() == CK_BooleanToSignedIntegral)
-      IntResult = (uint64_t)-1;
-    return Success(IntResult, E);
-  }
-
-  case CK_FixedPointToBoolean: {
-    // Unsigned padding does not affect this.
-    APValue Val;
-    if (!Evaluate(Val, Info, SubExpr))
-      return false;
-    return Success(Val.getInt().getBoolValue(), E);
-  }
-
-  case CK_IntegralCast: {
-    if (!Visit(SubExpr))
-      return false;
-
-    if (!Result.isInt()) {
-      // Allow casts of address-of-label differences if they are no-ops
-      // or narrowing.  (The narrowing case isn't actually guaranteed to
-      // be constant-evaluatable except in some narrow cases which are hard
-      // to detect here.  We let it through on the assumption the user knows
-      // what they are doing.)
-      if (Result.isAddrLabelDiff())
-        return Info.Ctx.getTypeSize(DestType) <= Info.Ctx.getTypeSize(SrcType);
-      // Only allow casts of lvalues if they are lossless.
-      return Info.Ctx.getTypeSize(DestType) == Info.Ctx.getTypeSize(SrcType);
-    }
-
-    return Success(HandleIntToIntCast(Info, E, DestType, SrcType,
-                                      Result.getInt()), E);
-  }
-
-  case CK_PointerToIntegral: {
-    CCEDiag(E, diag::note_constexpr_invalid_cast) << 2;
-
-    LValue LV;
-    if (!EvaluatePointer(SubExpr, LV, Info))
-      return false;
-
-    if (LV.getLValueBase()) {
-      // Only allow based lvalue casts if they are lossless.
-      // FIXME: Allow a larger integer size than the pointer size, and allow
-      // narrowing back down to pointer width in subsequent integral casts.
-      // FIXME: Check integer type's active bits, not its type size.
-      if (Info.Ctx.getTypeSize(DestType) != Info.Ctx.getTypeSize(SrcType))
-        return Error(E);
-
-      LV.Designator.setInvalid();
-      LV.moveInto(Result);
-      return true;
-    }
-
-    APSInt AsInt;
-    APValue V;
-    LV.moveInto(V);
-    if (!V.toIntegralConstant(AsInt, SrcType, Info.Ctx))
-      llvm_unreachable("Can't cast this!");
-
-    return Success(HandleIntToIntCast(Info, E, DestType, SrcType, AsInt), E);
-  }
-
-  case CK_IntegralComplexToReal: {
-    ComplexValue C;
-    if (!EvaluateComplex(SubExpr, C, Info))
-      return false;
-    return Success(C.getComplexIntReal(), E);
-  }
-
-  case CK_FloatingToIntegral: {
-    APFloat F(0.0);
-    if (!EvaluateFloat(SubExpr, F, Info))
-      return false;
-
-    APSInt Value;
-    if (!HandleFloatToIntCast(Info, E, SrcType, F, DestType, Value))
-      return false;
-    return Success(Value, E);
-  }
-  }
-
-  llvm_unreachable("unknown cast resulting in integral value");
-}
-
-bool IntExprEvaluator::VisitUnaryReal(const UnaryOperator *E) {
-  if (E->getSubExpr()->getType()->isAnyComplexType()) {
-    ComplexValue LV;
-    if (!EvaluateComplex(E->getSubExpr(), LV, Info))
-      return false;
-    if (!LV.isComplexInt())
-      return Error(E);
-    return Success(LV.getComplexIntReal(), E);
-  }
-
-  return Visit(E->getSubExpr());
-}
-
-bool IntExprEvaluator::VisitUnaryImag(const UnaryOperator *E) {
-  if (E->getSubExpr()->getType()->isComplexIntegerType()) {
-    ComplexValue LV;
-    if (!EvaluateComplex(E->getSubExpr(), LV, Info))
-      return false;
-    if (!LV.isComplexInt())
-      return Error(E);
-    return Success(LV.getComplexIntImag(), E);
-  }
-
-  VisitIgnoredValue(E->getSubExpr());
-  return Success(0, E);
-}
-
-bool IntExprEvaluator::VisitSizeOfPackExpr(const SizeOfPackExpr *E) {
-  return Success(E->getPackLength(), E);
-}
-
-bool IntExprEvaluator::VisitCXXNoexceptExpr(const CXXNoexceptExpr *E) {
-  return Success(E->getValue(), E);
-}
-
-bool FixedPointExprEvaluator::VisitUnaryOperator(const UnaryOperator *E) {
-  switch (E->getOpcode()) {
-    default:
-      // Invalid unary operators
-      return Error(E);
-    case UO_Plus:
-      // The result is just the value.
-      return Visit(E->getSubExpr());
-    case UO_Minus: {
-      if (!Visit(E->getSubExpr())) return false;
-      if (!Result.isInt()) return Error(E);
-      const APSInt &Value = Result.getInt();
-      if (Value.isSigned() && Value.isMinSignedValue() && E->canOverflow()) {
-        SmallString<64> S;
-        FixedPointValueToString(S, Value,
-                                Info.Ctx.getTypeInfo(E->getType()).Width);
-        Info.CCEDiag(E, diag::note_constexpr_overflow) << S << E->getType();
-        if (Info.noteUndefinedBehavior()) return false;
-      }
-      return Success(-Value, E);
-    }
-    case UO_LNot: {
-      bool bres;
-      if (!EvaluateAsBooleanCondition(E->getSubExpr(), bres, Info))
-        return false;
-      return Success(!bres, E);
-    }
-  }
-}
-
-//===----------------------------------------------------------------------===//
-// Float Evaluation
-//===----------------------------------------------------------------------===//
-
-namespace {
-class FloatExprEvaluator
-  : public ExprEvaluatorBase<FloatExprEvaluator> {
-  APFloat &Result;
-public:
-  FloatExprEvaluator(EvalInfo &info, APFloat &result)
-    : ExprEvaluatorBaseTy(info), Result(result) {}
-
-  bool Success(const APValue &V, const Expr *e) {
-    Result = V.getFloat();
-    return true;
-  }
-
-  bool ZeroInitialization(const Expr *E) {
-    Result = APFloat::getZero(Info.Ctx.getFloatTypeSemantics(E->getType()));
-    return true;
-  }
-
-  bool VisitCallExpr(const CallExpr *E);
-
-  bool VisitUnaryOperator(const UnaryOperator *E);
-  bool VisitBinaryOperator(const BinaryOperator *E);
-  bool VisitFloatingLiteral(const FloatingLiteral *E);
-  bool VisitCastExpr(const CastExpr *E);
-
-  bool VisitUnaryReal(const UnaryOperator *E);
-  bool VisitUnaryImag(const UnaryOperator *E);
-
-  // FIXME: Missing: array subscript of vector, member of vector
-};
-} // end anonymous namespace
-
-static bool EvaluateFloat(const Expr* E, APFloat& Result, EvalInfo &Info) {
-  assert(E->isRValue() && E->getType()->isRealFloatingType());
-  return FloatExprEvaluator(Info, Result).Visit(E);
-}
-
-static bool TryEvaluateBuiltinNaN(const ASTContext &Context,
-                                  QualType ResultTy,
-                                  const Expr *Arg,
-                                  bool SNaN,
-                                  llvm::APFloat &Result) {
-  const StringLiteral *S = dyn_cast<StringLiteral>(Arg->IgnoreParenCasts());
-  if (!S) return false;
-
-  const llvm::fltSemantics &Sem = Context.getFloatTypeSemantics(ResultTy);
-
-  llvm::APInt fill;
-
-  // Treat empty strings as if they were zero.
-  if (S->getString().empty())
-    fill = llvm::APInt(32, 0);
-  else if (S->getString().getAsInteger(0, fill))
-    return false;
-
-  if (Context.getTargetInfo().isNan2008()) {
-    if (SNaN)
-      Result = llvm::APFloat::getSNaN(Sem, false, &fill);
-    else
-      Result = llvm::APFloat::getQNaN(Sem, false, &fill);
-  } else {
-    // Prior to IEEE 754-2008, architectures were allowed to choose whether
-    // the first bit of their significand was set for qNaN or sNaN. MIPS chose
-    // a different encoding to what became a standard in 2008, and for pre-
-    // 2008 revisions, MIPS interpreted sNaN-2008 as qNan and qNaN-2008 as
-    // sNaN. This is now known as "legacy NaN" encoding.
-    if (SNaN)
-      Result = llvm::APFloat::getQNaN(Sem, false, &fill);
-    else
-      Result = llvm::APFloat::getSNaN(Sem, false, &fill);
-  }
-
-  return true;
-}
-
-bool FloatExprEvaluator::VisitCallExpr(const CallExpr *E) {
-  switch (E->getBuiltinCallee()) {
-  default:
-    return ExprEvaluatorBaseTy::VisitCallExpr(E);
-
-  case Builtin::BI__builtin_huge_val:
-  case Builtin::BI__builtin_huge_valf:
-  case Builtin::BI__builtin_huge_vall:
-  case Builtin::BI__builtin_huge_valf128:
-  case Builtin::BI__builtin_inf:
-  case Builtin::BI__builtin_inff:
-  case Builtin::BI__builtin_infl:
-  case Builtin::BI__builtin_inff128: {
-    const llvm::fltSemantics &Sem =
-      Info.Ctx.getFloatTypeSemantics(E->getType());
-    Result = llvm::APFloat::getInf(Sem);
-    return true;
-  }
-
-  case Builtin::BI__builtin_nans:
-  case Builtin::BI__builtin_nansf:
-  case Builtin::BI__builtin_nansl:
-  case Builtin::BI__builtin_nansf128:
-    if (!TryEvaluateBuiltinNaN(Info.Ctx, E->getType(), E->getArg(0),
-                               true, Result))
-      return Error(E);
-    return true;
-
-  case Builtin::BI__builtin_nan:
-  case Builtin::BI__builtin_nanf:
-  case Builtin::BI__builtin_nanl:
-  case Builtin::BI__builtin_nanf128:
-    // If this is __builtin_nan() turn this into a nan, otherwise we
-    // can't constant fold it.
-    if (!TryEvaluateBuiltinNaN(Info.Ctx, E->getType(), E->getArg(0),
-                               false, Result))
-      return Error(E);
-    return true;
-
-  case Builtin::BI__builtin_fabs:
-  case Builtin::BI__builtin_fabsf:
-  case Builtin::BI__builtin_fabsl:
-  case Builtin::BI__builtin_fabsf128:
-    if (!EvaluateFloat(E->getArg(0), Result, Info))
-      return false;
-
-    if (Result.isNegative())
-      Result.changeSign();
-    return true;
-
-  // FIXME: Builtin::BI__builtin_powi
-  // FIXME: Builtin::BI__builtin_powif
-  // FIXME: Builtin::BI__builtin_powil
-
-  case Builtin::BI__builtin_copysign:
-  case Builtin::BI__builtin_copysignf:
-  case Builtin::BI__builtin_copysignl:
-  case Builtin::BI__builtin_copysignf128: {
-    APFloat RHS(0.);
-    if (!EvaluateFloat(E->getArg(0), Result, Info) ||
-        !EvaluateFloat(E->getArg(1), RHS, Info))
-      return false;
-    Result.copySign(RHS);
-    return true;
-  }
-  }
-}
-
-bool FloatExprEvaluator::VisitUnaryReal(const UnaryOperator *E) {
-  if (E->getSubExpr()->getType()->isAnyComplexType()) {
-    ComplexValue CV;
-    if (!EvaluateComplex(E->getSubExpr(), CV, Info))
-      return false;
-    Result = CV.FloatReal;
-    return true;
-  }
-
-  return Visit(E->getSubExpr());
-}
-
-bool FloatExprEvaluator::VisitUnaryImag(const UnaryOperator *E) {
-  if (E->getSubExpr()->getType()->isAnyComplexType()) {
-    ComplexValue CV;
-    if (!EvaluateComplex(E->getSubExpr(), CV, Info))
-      return false;
-    Result = CV.FloatImag;
-    return true;
-  }
-
-  VisitIgnoredValue(E->getSubExpr());
-  const llvm::fltSemantics &Sem = Info.Ctx.getFloatTypeSemantics(E->getType());
-  Result = llvm::APFloat::getZero(Sem);
-  return true;
-}
-
-bool FloatExprEvaluator::VisitUnaryOperator(const UnaryOperator *E) {
-  switch (E->getOpcode()) {
-  default: return Error(E);
-  case UO_Plus:
-    return EvaluateFloat(E->getSubExpr(), Result, Info);
-  case UO_Minus:
-    if (!EvaluateFloat(E->getSubExpr(), Result, Info))
-      return false;
-    Result.changeSign();
-    return true;
-  }
-}
-
-bool FloatExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) {
-  if (E->isPtrMemOp() || E->isAssignmentOp() || E->getOpcode() == BO_Comma)
-    return ExprEvaluatorBaseTy::VisitBinaryOperator(E);
-
-  APFloat RHS(0.0);
-  bool LHSOK = EvaluateFloat(E->getLHS(), Result, Info);
-  if (!LHSOK && !Info.noteFailure())
-    return false;
-  return EvaluateFloat(E->getRHS(), RHS, Info) && LHSOK &&
-         handleFloatFloatBinOp(Info, E, Result, E->getOpcode(), RHS);
-}
-
-bool FloatExprEvaluator::VisitFloatingLiteral(const FloatingLiteral *E) {
-  Result = E->getValue();
-  return true;
-}
-
-bool FloatExprEvaluator::VisitCastExpr(const CastExpr *E) {
-  const Expr* SubExpr = E->getSubExpr();
-
-  switch (E->getCastKind()) {
-  default:
-    return ExprEvaluatorBaseTy::VisitCastExpr(E);
-
-  case CK_IntegralToFloating: {
-    APSInt IntResult;
-    return EvaluateInteger(SubExpr, IntResult, Info) &&
-           HandleIntToFloatCast(Info, E, SubExpr->getType(), IntResult,
-                                E->getType(), Result);
-  }
-
-  case CK_FloatingCast: {
-    if (!Visit(SubExpr))
-      return false;
-    return HandleFloatToFloatCast(Info, E, SubExpr->getType(), E->getType(),
-                                  Result);
-  }
-
-  case CK_FloatingComplexToReal: {
-    ComplexValue V;
-    if (!EvaluateComplex(SubExpr, V, Info))
-      return false;
-    Result = V.getComplexFloatReal();
-    return true;
-  }
-  }
-}
-
-//===----------------------------------------------------------------------===//
-// Complex Evaluation (for float and integer)
-//===----------------------------------------------------------------------===//
-
-namespace {
-class ComplexExprEvaluator
-  : public ExprEvaluatorBase<ComplexExprEvaluator> {
-  ComplexValue &Result;
-
-public:
-  ComplexExprEvaluator(EvalInfo &info, ComplexValue &Result)
-    : ExprEvaluatorBaseTy(info), Result(Result) {}
-
-  bool Success(const APValue &V, const Expr *e) {
-    Result.setFrom(V);
-    return true;
-  }
-
-  bool ZeroInitialization(const Expr *E);
-
-  //===--------------------------------------------------------------------===//
-  //                            Visitor Methods
-  //===--------------------------------------------------------------------===//
-
-  bool VisitImaginaryLiteral(const ImaginaryLiteral *E);
-  bool VisitCastExpr(const CastExpr *E);
-  bool VisitBinaryOperator(const BinaryOperator *E);
-  bool VisitUnaryOperator(const UnaryOperator *E);
-  bool VisitInitListExpr(const InitListExpr *E);
-};
-} // end anonymous namespace
-
-static bool EvaluateComplex(const Expr *E, ComplexValue &Result,
-                            EvalInfo &Info) {
-  assert(E->isRValue() && E->getType()->isAnyComplexType());
-  return ComplexExprEvaluator(Info, Result).Visit(E);
-}
-
-bool ComplexExprEvaluator::ZeroInitialization(const Expr *E) {
-  QualType ElemTy = E->getType()->castAs<ComplexType>()->getElementType();
-  if (ElemTy->isRealFloatingType()) {
-    Result.makeComplexFloat();
-    APFloat Zero = APFloat::getZero(Info.Ctx.getFloatTypeSemantics(ElemTy));
-    Result.FloatReal = Zero;
-    Result.FloatImag = Zero;
-  } else {
-    Result.makeComplexInt();
-    APSInt Zero = Info.Ctx.MakeIntValue(0, ElemTy);
-    Result.IntReal = Zero;
-    Result.IntImag = Zero;
-  }
-  return true;
-}
-
-bool ComplexExprEvaluator::VisitImaginaryLiteral(const ImaginaryLiteral *E) {
-  const Expr* SubExpr = E->getSubExpr();
-
-  if (SubExpr->getType()->isRealFloatingType()) {
-    Result.makeComplexFloat();
-    APFloat &Imag = Result.FloatImag;
-    if (!EvaluateFloat(SubExpr, Imag, Info))
-      return false;
-
-    Result.FloatReal = APFloat(Imag.getSemantics());
-    return true;
-  } else {
-    assert(SubExpr->getType()->isIntegerType() &&
-           "Unexpected imaginary literal.");
-
-    Result.makeComplexInt();
-    APSInt &Imag = Result.IntImag;
-    if (!EvaluateInteger(SubExpr, Imag, Info))
-      return false;
-
-    Result.IntReal = APSInt(Imag.getBitWidth(), !Imag.isSigned());
-    return true;
-  }
-}
-
-bool ComplexExprEvaluator::VisitCastExpr(const CastExpr *E) {
-
-  switch (E->getCastKind()) {
-  case CK_BitCast:
-  case CK_BaseToDerived:
-  case CK_DerivedToBase:
-  case CK_UncheckedDerivedToBase:
-  case CK_Dynamic:
-  case CK_ToUnion:
-  case CK_ArrayToPointerDecay:
-  case CK_FunctionToPointerDecay:
-  case CK_NullToPointer:
-  case CK_NullToMemberPointer:
-  case CK_BaseToDerivedMemberPointer:
-  case CK_DerivedToBaseMemberPointer:
-  case CK_MemberPointerToBoolean:
-  case CK_ReinterpretMemberPointer:
-  case CK_ConstructorConversion:
-  case CK_IntegralToPointer:
-  case CK_PointerToIntegral:
-  case CK_PointerToBoolean:
-  case CK_ToVoid:
-  case CK_VectorSplat:
-  case CK_IntegralCast:
-  case CK_BooleanToSignedIntegral:
-  case CK_IntegralToBoolean:
-  case CK_IntegralToFloating:
-  case CK_FloatingToIntegral:
-  case CK_FloatingToBoolean:
-  case CK_FloatingCast:
-  case CK_CPointerToObjCPointerCast:
-  case CK_BlockPointerToObjCPointerCast:
-  case CK_AnyPointerToBlockPointerCast:
-  case CK_ObjCObjectLValueCast:
-  case CK_FloatingComplexToReal:
-  case CK_FloatingComplexToBoolean:
-  case CK_IntegralComplexToReal:
-  case CK_IntegralComplexToBoolean:
-  case CK_ARCProduceObject:
-  case CK_ARCConsumeObject:
-  case CK_ARCReclaimReturnedObject:
-  case CK_ARCExtendBlockObject:
-  case CK_CopyAndAutoreleaseBlockObject:
-  case CK_BuiltinFnToFnPtr:
-  case CK_ZeroToOCLOpaqueType:
-  case CK_NonAtomicToAtomic:
-  case CK_AddressSpaceConversion:
-  case CK_IntToOCLSampler:
-  case CK_FixedPointCast:
-  case CK_FixedPointToBoolean:
-    llvm_unreachable("invalid cast kind for complex value");
-
-  case CK_LValueToRValue:
-  case CK_AtomicToNonAtomic:
-  case CK_NoOp:
-    return ExprEvaluatorBaseTy::VisitCastExpr(E);
-
-  case CK_Dependent:
-  case CK_LValueBitCast:
-  case CK_UserDefinedConversion:
-    return Error(E);
-
-  case CK_FloatingRealToComplex: {
-    APFloat &Real = Result.FloatReal;
-    if (!EvaluateFloat(E->getSubExpr(), Real, Info))
-      return false;
-
-    Result.makeComplexFloat();
-    Result.FloatImag = APFloat(Real.getSemantics());
-    return true;
-  }
-
-  case CK_FloatingComplexCast: {
-    if (!Visit(E->getSubExpr()))
-      return false;
-
-    QualType To = E->getType()->getAs<ComplexType>()->getElementType();
-    QualType From
-      = E->getSubExpr()->getType()->getAs<ComplexType>()->getElementType();
-
-    return HandleFloatToFloatCast(Info, E, From, To, Result.FloatReal) &&
-           HandleFloatToFloatCast(Info, E, From, To, Result.FloatImag);
-  }
-
-  case CK_FloatingComplexToIntegralComplex: {
-    if (!Visit(E->getSubExpr()))
-      return false;
-
-    QualType To = E->getType()->getAs<ComplexType>()->getElementType();
-    QualType From
-      = E->getSubExpr()->getType()->getAs<ComplexType>()->getElementType();
-    Result.makeComplexInt();
-    return HandleFloatToIntCast(Info, E, From, Result.FloatReal,
-                                To, Result.IntReal) &&
-           HandleFloatToIntCast(Info, E, From, Result.FloatImag,
-                                To, Result.IntImag);
-  }
-
-  case CK_IntegralRealToComplex: {
-    APSInt &Real = Result.IntReal;
-    if (!EvaluateInteger(E->getSubExpr(), Real, Info))
-      return false;
-
-    Result.makeComplexInt();
-    Result.IntImag = APSInt(Real.getBitWidth(), !Real.isSigned());
-    return true;
-  }
-
-  case CK_IntegralComplexCast: {
-    if (!Visit(E->getSubExpr()))
-      return false;
-
-    QualType To = E->getType()->getAs<ComplexType>()->getElementType();
-    QualType From
-      = E->getSubExpr()->getType()->getAs<ComplexType>()->getElementType();
-
-    Result.IntReal = HandleIntToIntCast(Info, E, To, From, Result.IntReal);
-    Result.IntImag = HandleIntToIntCast(Info, E, To, From, Result.IntImag);
-    return true;
-  }
-
-  case CK_IntegralComplexToFloatingComplex: {
-    if (!Visit(E->getSubExpr()))
-      return false;
-
-    QualType To = E->getType()->castAs<ComplexType>()->getElementType();
-    QualType From
-      = E->getSubExpr()->getType()->castAs<ComplexType>()->getElementType();
-    Result.makeComplexFloat();
-    return HandleIntToFloatCast(Info, E, From, Result.IntReal,
-                                To, Result.FloatReal) &&
-           HandleIntToFloatCast(Info, E, From, Result.IntImag,
-                                To, Result.FloatImag);
-  }
-  }
-
-  llvm_unreachable("unknown cast resulting in complex value");
-}
-
-bool ComplexExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) {
-  if (E->isPtrMemOp() || E->isAssignmentOp() || E->getOpcode() == BO_Comma)
-    return ExprEvaluatorBaseTy::VisitBinaryOperator(E);
-
-  // Track whether the LHS or RHS is real at the type system level. When this is
-  // the case we can simplify our evaluation strategy.
-  bool LHSReal = false, RHSReal = false;
-
-  bool LHSOK;
-  if (E->getLHS()->getType()->isRealFloatingType()) {
-    LHSReal = true;
-    APFloat &Real = Result.FloatReal;
-    LHSOK = EvaluateFloat(E->getLHS(), Real, Info);
-    if (LHSOK) {
-      Result.makeComplexFloat();
-      Result.FloatImag = APFloat(Real.getSemantics());
-    }
-  } else {
-    LHSOK = Visit(E->getLHS());
-  }
-  if (!LHSOK && !Info.noteFailure())
-    return false;
-
-  ComplexValue RHS;
-  if (E->getRHS()->getType()->isRealFloatingType()) {
-    RHSReal = true;
-    APFloat &Real = RHS.FloatReal;
-    if (!EvaluateFloat(E->getRHS(), Real, Info) || !LHSOK)
-      return false;
-    RHS.makeComplexFloat();
-    RHS.FloatImag = APFloat(Real.getSemantics());
-  } else if (!EvaluateComplex(E->getRHS(), RHS, Info) || !LHSOK)
-    return false;
-
-  assert(!(LHSReal && RHSReal) &&
-         "Cannot have both operands of a complex operation be real.");
-  switch (E->getOpcode()) {
-  default: return Error(E);
-  case BO_Add:
-    if (Result.isComplexFloat()) {
-      Result.getComplexFloatReal().add(RHS.getComplexFloatReal(),
-                                       APFloat::rmNearestTiesToEven);
-      if (LHSReal)
-        Result.getComplexFloatImag() = RHS.getComplexFloatImag();
-      else if (!RHSReal)
-        Result.getComplexFloatImag().add(RHS.getComplexFloatImag(),
-                                         APFloat::rmNearestTiesToEven);
-    } else {
-      Result.getComplexIntReal() += RHS.getComplexIntReal();
-      Result.getComplexIntImag() += RHS.getComplexIntImag();
-    }
-    break;
-  case BO_Sub:
-    if (Result.isComplexFloat()) {
-      Result.getComplexFloatReal().subtract(RHS.getComplexFloatReal(),
-                                            APFloat::rmNearestTiesToEven);
-      if (LHSReal) {
-        Result.getComplexFloatImag() = RHS.getComplexFloatImag();
-        Result.getComplexFloatImag().changeSign();
-      } else if (!RHSReal) {
-        Result.getComplexFloatImag().subtract(RHS.getComplexFloatImag(),
-                                              APFloat::rmNearestTiesToEven);
-      }
-    } else {
-      Result.getComplexIntReal() -= RHS.getComplexIntReal();
-      Result.getComplexIntImag() -= RHS.getComplexIntImag();
-    }
-    break;
-  case BO_Mul:
-    if (Result.isComplexFloat()) {
-      // This is an implementation of complex multiplication according to the
-      // constraints laid out in C11 Annex G. The implementation uses the
-      // following naming scheme:
-      //   (a + ib) * (c + id)
-      ComplexValue LHS = Result;
-      APFloat &A = LHS.getComplexFloatReal();
-      APFloat &B = LHS.getComplexFloatImag();
-      APFloat &C = RHS.getComplexFloatReal();
-      APFloat &D = RHS.getComplexFloatImag();
-      APFloat &ResR = Result.getComplexFloatReal();
-      APFloat &ResI = Result.getComplexFloatImag();
-      if (LHSReal) {
-        assert(!RHSReal && "Cannot have two real operands for a complex op!");
-        ResR = A * C;
-        ResI = A * D;
-      } else if (RHSReal) {
-        ResR = C * A;
-        ResI = C * B;
-      } else {
-        // In the fully general case, we need to handle NaNs and infinities
-        // robustly.
-        APFloat AC = A * C;
-        APFloat BD = B * D;
-        APFloat AD = A * D;
-        APFloat BC = B * C;
-        ResR = AC - BD;
-        ResI = AD + BC;
-        if (ResR.isNaN() && ResI.isNaN()) {
-          bool Recalc = false;
-          if (A.isInfinity() || B.isInfinity()) {
-            A = APFloat::copySign(
-                APFloat(A.getSemantics(), A.isInfinity() ? 1 : 0), A);
-            B = APFloat::copySign(
-                APFloat(B.getSemantics(), B.isInfinity() ? 1 : 0), B);
-            if (C.isNaN())
-              C = APFloat::copySign(APFloat(C.getSemantics()), C);
-            if (D.isNaN())
-              D = APFloat::copySign(APFloat(D.getSemantics()), D);
-            Recalc = true;
-          }
-          if (C.isInfinity() || D.isInfinity()) {
-            C = APFloat::copySign(
-                APFloat(C.getSemantics(), C.isInfinity() ? 1 : 0), C);
-            D = APFloat::copySign(
-                APFloat(D.getSemantics(), D.isInfinity() ? 1 : 0), D);
-            if (A.isNaN())
-              A = APFloat::copySign(APFloat(A.getSemantics()), A);
-            if (B.isNaN())
-              B = APFloat::copySign(APFloat(B.getSemantics()), B);
-            Recalc = true;
-          }
-          if (!Recalc && (AC.isInfinity() || BD.isInfinity() ||
-                          AD.isInfinity() || BC.isInfinity())) {
-            if (A.isNaN())
-              A = APFloat::copySign(APFloat(A.getSemantics()), A);
-            if (B.isNaN())
-              B = APFloat::copySign(APFloat(B.getSemantics()), B);
-            if (C.isNaN())
-              C = APFloat::copySign(APFloat(C.getSemantics()), C);
-            if (D.isNaN())
-              D = APFloat::copySign(APFloat(D.getSemantics()), D);
-            Recalc = true;
-          }
-          if (Recalc) {
-            ResR = APFloat::getInf(A.getSemantics()) * (A * C - B * D);
-            ResI = APFloat::getInf(A.getSemantics()) * (A * D + B * C);
-          }
-        }
-      }
-    } else {
-      ComplexValue LHS = Result;
-      Result.getComplexIntReal() =
-        (LHS.getComplexIntReal() * RHS.getComplexIntReal() -
-         LHS.getComplexIntImag() * RHS.getComplexIntImag());
-      Result.getComplexIntImag() =
-        (LHS.getComplexIntReal() * RHS.getComplexIntImag() +
-         LHS.getComplexIntImag() * RHS.getComplexIntReal());
-    }
-    break;
-  case BO_Div:
-    if (Result.isComplexFloat()) {
-      // This is an implementation of complex division according to the
-      // constraints laid out in C11 Annex G. The implementation uses the
-      // following naming scheme:
-      //   (a + ib) / (c + id)
-      ComplexValue LHS = Result;
-      APFloat &A = LHS.getComplexFloatReal();
-      APFloat &B = LHS.getComplexFloatImag();
-      APFloat &C = RHS.getComplexFloatReal();
-      APFloat &D = RHS.getComplexFloatImag();
-      APFloat &ResR = Result.getComplexFloatReal();
-      APFloat &ResI = Result.getComplexFloatImag();
-      if (RHSReal) {
-        ResR = A / C;
-        ResI = B / C;
-      } else {
-        if (LHSReal) {
-          // No real optimizations we can do here, stub out with zero.
-          B = APFloat::getZero(A.getSemantics());
-        }
-        int DenomLogB = 0;
-        APFloat MaxCD = maxnum(abs(C), abs(D));
-        if (MaxCD.isFinite()) {
-          DenomLogB = ilogb(MaxCD);
-          C = scalbn(C, -DenomLogB, APFloat::rmNearestTiesToEven);
-          D = scalbn(D, -DenomLogB, APFloat::rmNearestTiesToEven);
-        }
-        APFloat Denom = C * C + D * D;
-        ResR = scalbn((A * C + B * D) / Denom, -DenomLogB,
-                      APFloat::rmNearestTiesToEven);
-        ResI = scalbn((B * C - A * D) / Denom, -DenomLogB,
-                      APFloat::rmNearestTiesToEven);
-        if (ResR.isNaN() && ResI.isNaN()) {
-          if (Denom.isPosZero() && (!A.isNaN() || !B.isNaN())) {
-            ResR = APFloat::getInf(ResR.getSemantics(), C.isNegative()) * A;
-            ResI = APFloat::getInf(ResR.getSemantics(), C.isNegative()) * B;
-          } else if ((A.isInfinity() || B.isInfinity()) && C.isFinite() &&
-                     D.isFinite()) {
-            A = APFloat::copySign(
-                APFloat(A.getSemantics(), A.isInfinity() ? 1 : 0), A);
-            B = APFloat::copySign(
-                APFloat(B.getSemantics(), B.isInfinity() ? 1 : 0), B);
-            ResR = APFloat::getInf(ResR.getSemantics()) * (A * C + B * D);
-            ResI = APFloat::getInf(ResI.getSemantics()) * (B * C - A * D);
-          } else if (MaxCD.isInfinity() && A.isFinite() && B.isFinite()) {
-            C = APFloat::copySign(
-                APFloat(C.getSemantics(), C.isInfinity() ? 1 : 0), C);
-            D = APFloat::copySign(
-                APFloat(D.getSemantics(), D.isInfinity() ? 1 : 0), D);
-            ResR = APFloat::getZero(ResR.getSemantics()) * (A * C + B * D);
-            ResI = APFloat::getZero(ResI.getSemantics()) * (B * C - A * D);
-          }
-        }
-      }
-    } else {
-      if (RHS.getComplexIntReal() == 0 && RHS.getComplexIntImag() == 0)
-        return Error(E, diag::note_expr_divide_by_zero);
-
-      ComplexValue LHS = Result;
-      APSInt Den = RHS.getComplexIntReal() * RHS.getComplexIntReal() +
-        RHS.getComplexIntImag() * RHS.getComplexIntImag();
-      Result.getComplexIntReal() =
-        (LHS.getComplexIntReal() * RHS.getComplexIntReal() +
-         LHS.getComplexIntImag() * RHS.getComplexIntImag()) / Den;
-      Result.getComplexIntImag() =
-        (LHS.getComplexIntImag() * RHS.getComplexIntReal() -
-         LHS.getComplexIntReal() * RHS.getComplexIntImag()) / Den;
-    }
-    break;
-  }
-
-  return true;
-}
-
-bool ComplexExprEvaluator::VisitUnaryOperator(const UnaryOperator *E) {
-  // Get the operand value into 'Result'.
-  if (!Visit(E->getSubExpr()))
-    return false;
-
-  switch (E->getOpcode()) {
-  default:
-    return Error(E);
-  case UO_Extension:
-    return true;
-  case UO_Plus:
-    // The result is always just the subexpr.
-    return true;
-  case UO_Minus:
-    if (Result.isComplexFloat()) {
-      Result.getComplexFloatReal().changeSign();
-      Result.getComplexFloatImag().changeSign();
-    }
-    else {
-      Result.getComplexIntReal() = -Result.getComplexIntReal();
-      Result.getComplexIntImag() = -Result.getComplexIntImag();
-    }
-    return true;
-  case UO_Not:
-    if (Result.isComplexFloat())
-      Result.getComplexFloatImag().changeSign();
-    else
-      Result.getComplexIntImag() = -Result.getComplexIntImag();
-    return true;
-  }
-}
-
-bool ComplexExprEvaluator::VisitInitListExpr(const InitListExpr *E) {
-  if (E->getNumInits() == 2) {
-    if (E->getType()->isComplexType()) {
-      Result.makeComplexFloat();
-      if (!EvaluateFloat(E->getInit(0), Result.FloatReal, Info))
-        return false;
-      if (!EvaluateFloat(E->getInit(1), Result.FloatImag, Info))
-        return false;
-    } else {
-      Result.makeComplexInt();
-      if (!EvaluateInteger(E->getInit(0), Result.IntReal, Info))
-        return false;
-      if (!EvaluateInteger(E->getInit(1), Result.IntImag, Info))
-        return false;
-    }
-    return true;
-  }
-  return ExprEvaluatorBaseTy::VisitInitListExpr(E);
-}
-
-//===----------------------------------------------------------------------===//
-// Atomic expression evaluation, essentially just handling the NonAtomicToAtomic
-// implicit conversion.
-//===----------------------------------------------------------------------===//
-
-namespace {
-class AtomicExprEvaluator :
-    public ExprEvaluatorBase<AtomicExprEvaluator> {
-  const LValue *This;
-  APValue &Result;
-public:
-  AtomicExprEvaluator(EvalInfo &Info, const LValue *This, APValue &Result)
-      : ExprEvaluatorBaseTy(Info), This(This), Result(Result) {}
-
-  bool Success(const APValue &V, const Expr *E) {
-    Result = V;
-    return true;
-  }
-
-  bool ZeroInitialization(const Expr *E) {
-    ImplicitValueInitExpr VIE(
-        E->getType()->castAs<AtomicType>()->getValueType());
-    // For atomic-qualified class (and array) types in C++, initialize the
-    // _Atomic-wrapped subobject directly, in-place.
-    return This ? EvaluateInPlace(Result, Info, *This, &VIE)
-                : Evaluate(Result, Info, &VIE);
-  }
-
-  bool VisitCastExpr(const CastExpr *E) {
-    switch (E->getCastKind()) {
-    default:
-      return ExprEvaluatorBaseTy::VisitCastExpr(E);
-    case CK_NonAtomicToAtomic:
-      return This ? EvaluateInPlace(Result, Info, *This, E->getSubExpr())
-                  : Evaluate(Result, Info, E->getSubExpr());
-    }
-  }
-};
-} // end anonymous namespace
-
-static bool EvaluateAtomic(const Expr *E, const LValue *This, APValue &Result,
-                           EvalInfo &Info) {
-  assert(E->isRValue() && E->getType()->isAtomicType());
-  return AtomicExprEvaluator(Info, This, Result).Visit(E);
-}
-
-//===----------------------------------------------------------------------===//
-// Void expression evaluation, primarily for a cast to void on the LHS of a
-// comma operator
-//===----------------------------------------------------------------------===//
-
-namespace {
-class VoidExprEvaluator
-  : public ExprEvaluatorBase<VoidExprEvaluator> {
-public:
-  VoidExprEvaluator(EvalInfo &Info) : ExprEvaluatorBaseTy(Info) {}
-
-  bool Success(const APValue &V, const Expr *e) { return true; }
-
-  bool ZeroInitialization(const Expr *E) { return true; }
-
-  bool VisitCastExpr(const CastExpr *E) {
-    switch (E->getCastKind()) {
-    default:
-      return ExprEvaluatorBaseTy::VisitCastExpr(E);
-    case CK_ToVoid:
-      VisitIgnoredValue(E->getSubExpr());
-      return true;
-    }
-  }
-
-  bool VisitCallExpr(const CallExpr *E) {
-    switch (E->getBuiltinCallee()) {
-    default:
-      return ExprEvaluatorBaseTy::VisitCallExpr(E);
-    case Builtin::BI__assume:
-    case Builtin::BI__builtin_assume:
-      // The argument is not evaluated!
-      return true;
-    }
-  }
-};
-} // end anonymous namespace
-
-static bool EvaluateVoid(const Expr *E, EvalInfo &Info) {
-  assert(E->isRValue() && E->getType()->isVoidType());
-  return VoidExprEvaluator(Info).Visit(E);
-}
-
-//===----------------------------------------------------------------------===//
-// Top level Expr::EvaluateAsRValue method.
-//===----------------------------------------------------------------------===//
-
-static bool Evaluate(APValue &Result, EvalInfo &Info, const Expr *E) {
-  // In C, function designators are not lvalues, but we evaluate them as if they
-  // are.
-  QualType T = E->getType();
-  if (E->isGLValue() || T->isFunctionType()) {
-    LValue LV;
-    if (!EvaluateLValue(E, LV, Info))
-      return false;
-    LV.moveInto(Result);
-  } else if (T->isVectorType()) {
-    if (!EvaluateVector(E, Result, Info))
-      return false;
-  } else if (T->isIntegralOrEnumerationType()) {
-    if (!IntExprEvaluator(Info, Result).Visit(E))
-      return false;
-  } else if (T->hasPointerRepresentation()) {
-    LValue LV;
-    if (!EvaluatePointer(E, LV, Info))
-      return false;
-    LV.moveInto(Result);
-  } else if (T->isRealFloatingType()) {
-    llvm::APFloat F(0.0);
-    if (!EvaluateFloat(E, F, Info))
-      return false;
-    Result = APValue(F);
-  } else if (T->isAnyComplexType()) {
-    ComplexValue C;
-    if (!EvaluateComplex(E, C, Info))
-      return false;
-    C.moveInto(Result);
-  } else if (T->isFixedPointType()) {
-    if (!FixedPointExprEvaluator(Info, Result).Visit(E)) return false;
-  } else if (T->isMemberPointerType()) {
-    MemberPtr P;
-    if (!EvaluateMemberPointer(E, P, Info))
-      return false;
-    P.moveInto(Result);
-    return true;
-  } else if (T->isArrayType()) {
-    LValue LV;
-    APValue &Value = createTemporary(E, false, LV, *Info.CurrentCall);
-    if (!EvaluateArray(E, LV, Value, Info))
-      return false;
-    Result = Value;
-  } else if (T->isRecordType()) {
-    LValue LV;
-    APValue &Value = createTemporary(E, false, LV, *Info.CurrentCall);
-    if (!EvaluateRecord(E, LV, Value, Info))
-      return false;
-    Result = Value;
-  } else if (T->isVoidType()) {
-    if (!Info.getLangOpts().CPlusPlus11)
-      Info.CCEDiag(E, diag::note_constexpr_nonliteral)
-        << E->getType();
-    if (!EvaluateVoid(E, Info))
-      return false;
-  } else if (T->isAtomicType()) {
-    QualType Unqual = T.getAtomicUnqualifiedType();
-    if (Unqual->isArrayType() || Unqual->isRecordType()) {
-      LValue LV;
-      APValue &Value = createTemporary(E, false, LV, *Info.CurrentCall);
-      if (!EvaluateAtomic(E, &LV, Value, Info))
-        return false;
-    } else {
-      if (!EvaluateAtomic(E, nullptr, Result, Info))
-        return false;
-    }
-  } else if (Info.getLangOpts().CPlusPlus11) {
-    Info.FFDiag(E, diag::note_constexpr_nonliteral) << E->getType();
-    return false;
-  } else {
-    Info.FFDiag(E, diag::note_invalid_subexpr_in_const_expr);
-    return false;
-  }
-
-  return true;
-}
-
-/// EvaluateInPlace - Evaluate an expression in-place in an APValue. In some
-/// cases, the in-place evaluation is essential, since later initializers for
-/// an object can indirectly refer to subobjects which were initialized earlier.
-static bool EvaluateInPlace(APValue &Result, EvalInfo &Info, const LValue &This,
-                            const Expr *E, bool AllowNonLiteralTypes) {
-  assert(!E->isValueDependent());
-
-  if (!AllowNonLiteralTypes && !CheckLiteralType(Info, E, &This))
-    return false;
-
-  if (E->isRValue()) {
-    // Evaluate arrays and record types in-place, so that later initializers can
-    // refer to earlier-initialized members of the object.
-    QualType T = E->getType();
-    if (T->isArrayType())
-      return EvaluateArray(E, This, Result, Info);
-    else if (T->isRecordType())
-      return EvaluateRecord(E, This, Result, Info);
-    else if (T->isAtomicType()) {
-      QualType Unqual = T.getAtomicUnqualifiedType();
-      if (Unqual->isArrayType() || Unqual->isRecordType())
-        return EvaluateAtomic(E, &This, Result, Info);
-    }
-  }
-
-  // For any other type, in-place evaluation is unimportant.
-  return Evaluate(Result, Info, E);
-}
-
-/// EvaluateAsRValue - Try to evaluate this expression, performing an implicit
-/// lvalue-to-rvalue cast if it is an lvalue.
-static bool EvaluateAsRValue(EvalInfo &Info, const Expr *E, APValue &Result) {
-  if (E->getType().isNull())
-    return false;
-
-  if (!CheckLiteralType(Info, E))
-    return false;
-
-  if (!::Evaluate(Result, Info, E))
-    return false;
-
-  if (E->isGLValue()) {
-    LValue LV;
-    LV.setFrom(Info.Ctx, Result);
-    if (!handleLValueToRValueConversion(Info, E, E->getType(), LV, Result))
-      return false;
-  }
-
-  // Check this core constant expression is a constant expression.
-  return CheckConstantExpression(Info, E->getExprLoc(), E->getType(), Result);
-}
-
-static bool FastEvaluateAsRValue(const Expr *Exp, Expr::EvalResult &Result,
-                                 const ASTContext &Ctx, bool &IsConst) {
-  // Fast-path evaluations of integer literals, since we sometimes see files
-  // containing vast quantities of these.
-  if (const IntegerLiteral *L = dyn_cast<IntegerLiteral>(Exp)) {
-    Result.Val = APValue(APSInt(L->getValue(),
-                                L->getType()->isUnsignedIntegerType()));
-    IsConst = true;
-    return true;
-  }
-
-  // This case should be rare, but we need to check it before we check on
-  // the type below.
-  if (Exp->getType().isNull()) {
-    IsConst = false;
-    return true;
-  }
-
-  // FIXME: Evaluating values of large array and record types can cause
-  // performance problems. Only do so in C++11 for now.
-  if (Exp->isRValue() && (Exp->getType()->isArrayType() ||
-                          Exp->getType()->isRecordType()) &&
-      !Ctx.getLangOpts().CPlusPlus11) {
-    IsConst = false;
-    return true;
-  }
-  return false;
-}
-
-static bool hasUnacceptableSideEffect(Expr::EvalStatus &Result,
-                                      Expr::SideEffectsKind SEK) {
-  return (SEK < Expr::SE_AllowSideEffects && Result.HasSideEffects) ||
-         (SEK < Expr::SE_AllowUndefinedBehavior && Result.HasUndefinedBehavior);
-}
-
-static bool EvaluateAsRValue(const Expr *E, Expr::EvalResult &Result,
-                             const ASTContext &Ctx, EvalInfo &Info) {
-  bool IsConst;
-  if (FastEvaluateAsRValue(E, Result, Ctx, IsConst))
-    return IsConst;
-
-  return EvaluateAsRValue(Info, E, Result.Val);
-}
-
-static bool EvaluateAsInt(const Expr *E, Expr::EvalResult &ExprResult,
-                          const ASTContext &Ctx,
-                          Expr::SideEffectsKind AllowSideEffects,
-                          EvalInfo &Info) {
-  if (!E->getType()->isIntegralOrEnumerationType())
-    return false;
-
-  if (!::EvaluateAsRValue(E, ExprResult, Ctx, Info) ||
-      !ExprResult.Val.isInt() ||
-      hasUnacceptableSideEffect(ExprResult, AllowSideEffects))
-    return false;
-
-  return true;
-}
-
-/// EvaluateAsRValue - Return true if this is a constant which we can fold using
-/// any crazy technique (that has nothing to do with language standards) that
-/// we want to.  If this function returns true, it returns the folded constant
-/// in Result. If this expression is a glvalue, an lvalue-to-rvalue conversion
-/// will be applied to the result.
-bool Expr::EvaluateAsRValue(EvalResult &Result, const ASTContext &Ctx,
-                            bool InConstantContext) const {
-  EvalInfo Info(Ctx, Result, EvalInfo::EM_IgnoreSideEffects);
-  Info.InConstantContext = InConstantContext;
-  return ::EvaluateAsRValue(this, Result, Ctx, Info);
-}
-
-bool Expr::EvaluateAsBooleanCondition(bool &Result,
-                                      const ASTContext &Ctx) const {
-  EvalResult Scratch;
-  return EvaluateAsRValue(Scratch, Ctx) &&
-         HandleConversionToBool(Scratch.Val, Result);
-}
-
-bool Expr::EvaluateAsInt(EvalResult &Result, const ASTContext &Ctx,
-                         SideEffectsKind AllowSideEffects) const {
-  EvalInfo Info(Ctx, Result, EvalInfo::EM_IgnoreSideEffects);
-  return ::EvaluateAsInt(this, Result, Ctx, AllowSideEffects, Info);
-}
-
-bool Expr::EvaluateAsFloat(APFloat &Result, const ASTContext &Ctx,
-                           SideEffectsKind AllowSideEffects) const {
-  if (!getType()->isRealFloatingType())
-    return false;
-
-  EvalResult ExprResult;
-  if (!EvaluateAsRValue(ExprResult, Ctx) || !ExprResult.Val.isFloat() ||
-      hasUnacceptableSideEffect(ExprResult, AllowSideEffects))
-    return false;
-
-  Result = ExprResult.Val.getFloat();
-  return true;
-}
-
-bool Expr::EvaluateAsLValue(EvalResult &Result, const ASTContext &Ctx) const {
-  EvalInfo Info(Ctx, Result, EvalInfo::EM_ConstantFold);
-
-  LValue LV;
-  if (!EvaluateLValue(this, LV, Info) || Result.HasSideEffects ||
-      !CheckLValueConstantExpression(Info, getExprLoc(),
-                                     Ctx.getLValueReferenceType(getType()), LV,
-                                     Expr::EvaluateForCodeGen))
-    return false;
-
-  LV.moveInto(Result.Val);
-  return true;
-}
-
-bool Expr::EvaluateAsConstantExpr(EvalResult &Result, ConstExprUsage Usage,
-                                  const ASTContext &Ctx) const {
-  EvalInfo::EvaluationMode EM = EvalInfo::EM_ConstantExpression;
-  EvalInfo Info(Ctx, Result, EM);
-  Info.InConstantContext = true;
-  if (!::Evaluate(Result.Val, Info, this))
-    return false;
-
-  return CheckConstantExpression(Info, getExprLoc(), getType(), Result.Val,
-                                 Usage);
-}
-
-bool Expr::EvaluateAsInitializer(APValue &Value, const ASTContext &Ctx,
-                                 const VarDecl *VD,
-                            SmallVectorImpl<PartialDiagnosticAt> &Notes) const {
-  // FIXME: Evaluating initializers for large array and record types can cause
-  // performance problems. Only do so in C++11 for now.
-  if (isRValue() && (getType()->isArrayType() || getType()->isRecordType()) &&
-      !Ctx.getLangOpts().CPlusPlus11)
-    return false;
-
-  Expr::EvalStatus EStatus;
-  EStatus.Diag = &Notes;
-
-  EvalInfo InitInfo(Ctx, EStatus, VD->isConstexpr()
-                                      ? EvalInfo::EM_ConstantExpression
-                                      : EvalInfo::EM_ConstantFold);
-  InitInfo.setEvaluatingDecl(VD, Value);
-  InitInfo.InConstantContext = true;
-
-  LValue LVal;
-  LVal.set(VD);
-
-  // C++11 [basic.start.init]p2:
-  //  Variables with static storage duration or thread storage duration shall be
-  //  zero-initialized before any other initialization takes place.
-  // This behavior is not present in C.
-  if (Ctx.getLangOpts().CPlusPlus && !VD->hasLocalStorage() &&
-      !VD->getType()->isReferenceType()) {
-    ImplicitValueInitExpr VIE(VD->getType());
-    if (!EvaluateInPlace(Value, InitInfo, LVal, &VIE,
-                         /*AllowNonLiteralTypes=*/true))
-      return false;
-  }
-
-  if (!EvaluateInPlace(Value, InitInfo, LVal, this,
-                       /*AllowNonLiteralTypes=*/true) ||
-      EStatus.HasSideEffects)
-    return false;
-
-  return CheckConstantExpression(InitInfo, VD->getLocation(), VD->getType(),
-                                 Value);
-}
-
-/// isEvaluatable - Call EvaluateAsRValue to see if this expression can be
-/// constant folded, but discard the result.
-bool Expr::isEvaluatable(const ASTContext &Ctx, SideEffectsKind SEK) const {
-  EvalResult Result;
-  return EvaluateAsRValue(Result, Ctx, /* in constant context */ true) &&
-         !hasUnacceptableSideEffect(Result, SEK);
-}
-
-APSInt Expr::EvaluateKnownConstInt(const ASTContext &Ctx,
-                    SmallVectorImpl<PartialDiagnosticAt> *Diag) const {
-  EvalResult EVResult;
-  EVResult.Diag = Diag;
-  EvalInfo Info(Ctx, EVResult, EvalInfo::EM_IgnoreSideEffects);
-  Info.InConstantContext = true;
-
-  bool Result = ::EvaluateAsRValue(this, EVResult, Ctx, Info);
-  (void)Result;
-  assert(Result && "Could not evaluate expression");
-  assert(EVResult.Val.isInt() && "Expression did not evaluate to integer");
-
-  return EVResult.Val.getInt();
-}
-
-APSInt Expr::EvaluateKnownConstIntCheckOverflow(
-    const ASTContext &Ctx, SmallVectorImpl<PartialDiagnosticAt> *Diag) const {
-  EvalResult EVResult;
-  EVResult.Diag = Diag;
-  EvalInfo Info(Ctx, EVResult, EvalInfo::EM_EvaluateForOverflow);
-  Info.InConstantContext = true;
-
-  bool Result = ::EvaluateAsRValue(Info, this, EVResult.Val);
-  (void)Result;
-  assert(Result && "Could not evaluate expression");
-  assert(EVResult.Val.isInt() && "Expression did not evaluate to integer");
-
-  return EVResult.Val.getInt();
-}
-
-void Expr::EvaluateForOverflow(const ASTContext &Ctx) const {
-  bool IsConst;
-  EvalResult EVResult;
-  if (!FastEvaluateAsRValue(this, EVResult, Ctx, IsConst)) {
-    EvalInfo Info(Ctx, EVResult, EvalInfo::EM_EvaluateForOverflow);
-    (void)::EvaluateAsRValue(Info, this, EVResult.Val);
-  }
-}
-
-bool Expr::EvalResult::isGlobalLValue() const {
-  assert(Val.isLValue());
-  return IsGlobalLValue(Val.getLValueBase());
-}
-
-
-/// isIntegerConstantExpr - this recursive routine will test if an expression is
-/// an integer constant expression.
-
-/// FIXME: Pass up a reason why! Invalid operation in i-c-e, division by zero,
-/// comma, etc
-
-// CheckICE - This function does the fundamental ICE checking: the returned
-// ICEDiag contains an ICEKind indicating whether the expression is an ICE,
-// and a (possibly null) SourceLocation indicating the location of the problem.
-//
-// Note that to reduce code duplication, this helper does no evaluation
-// itself; the caller checks whether the expression is evaluatable, and
-// in the rare cases where CheckICE actually cares about the evaluated
-// value, it calls into Evaluate.
-
-namespace {
-
-enum ICEKind {
-  /// This expression is an ICE.
-  IK_ICE,
-  /// This expression is not an ICE, but if it isn't evaluated, it's
-  /// a legal subexpression for an ICE. This return value is used to handle
-  /// the comma operator in C99 mode, and non-constant subexpressions.
-  IK_ICEIfUnevaluated,
-  /// This expression is not an ICE, and is not a legal subexpression for one.
-  IK_NotICE
-};
-
-struct ICEDiag {
-  ICEKind Kind;
-  SourceLocation Loc;
-
-  ICEDiag(ICEKind IK, SourceLocation l) : Kind(IK), Loc(l) {}
-};
-
-}
-
-static ICEDiag NoDiag() { return ICEDiag(IK_ICE, SourceLocation()); }
-
-static ICEDiag Worst(ICEDiag A, ICEDiag B) { return A.Kind >= B.Kind ? A : B; }
-
-static ICEDiag CheckEvalInICE(const Expr* E, const ASTContext &Ctx) {
-  Expr::EvalResult EVResult;
-  Expr::EvalStatus Status;
-  EvalInfo Info(Ctx, Status, EvalInfo::EM_ConstantExpression);
-
-  Info.InConstantContext = true;
-  if (!::EvaluateAsRValue(E, EVResult, Ctx, Info) || EVResult.HasSideEffects ||
-      !EVResult.Val.isInt())
-    return ICEDiag(IK_NotICE, E->getBeginLoc());
-
-  return NoDiag();
-}
-
-static ICEDiag CheckICE(const Expr* E, const ASTContext &Ctx) {
-  assert(!E->isValueDependent() && "Should not see value dependent exprs!");
-  if (!E->getType()->isIntegralOrEnumerationType())
-    return ICEDiag(IK_NotICE, E->getBeginLoc());
-
-  switch (E->getStmtClass()) {
-#define ABSTRACT_STMT(Node)
-#define STMT(Node, Base) case Expr::Node##Class:
-#define EXPR(Node, Base)
-#include "clang/AST/StmtNodes.inc"
-  case Expr::PredefinedExprClass:
-  case Expr::FloatingLiteralClass:
-  case Expr::ImaginaryLiteralClass:
-  case Expr::StringLiteralClass:
-  case Expr::ArraySubscriptExprClass:
-  case Expr::OMPArraySectionExprClass:
-  case Expr::MemberExprClass:
-  case Expr::CompoundAssignOperatorClass:
-  case Expr::CompoundLiteralExprClass:
-  case Expr::ExtVectorElementExprClass:
-  case Expr::DesignatedInitExprClass:
-  case Expr::ArrayInitLoopExprClass:
-  case Expr::ArrayInitIndexExprClass:
-  case Expr::NoInitExprClass:
-  case Expr::DesignatedInitUpdateExprClass:
-  case Expr::ImplicitValueInitExprClass:
-  case Expr::ParenListExprClass:
-  case Expr::VAArgExprClass:
-  case Expr::AddrLabelExprClass:
-  case Expr::StmtExprClass:
-  case Expr::CXXMemberCallExprClass:
-  case Expr::CUDAKernelCallExprClass:
-  case Expr::CXXDynamicCastExprClass:
-  case Expr::CXXTypeidExprClass:
-  case Expr::CXXUuidofExprClass:
-  case Expr::MSPropertyRefExprClass:
-  case Expr::MSPropertySubscriptExprClass:
-  case Expr::CXXNullPtrLiteralExprClass:
-  case Expr::UserDefinedLiteralClass:
-  case Expr::CXXThisExprClass:
-  case Expr::CXXThrowExprClass:
-  case Expr::CXXNewExprClass:
-  case Expr::CXXDeleteExprClass:
-  case Expr::CXXPseudoDestructorExprClass:
-  case Expr::UnresolvedLookupExprClass:
-  case Expr::TypoExprClass:
-  case Expr::DependentScopeDeclRefExprClass:
-  case Expr::CXXConstructExprClass:
-  case Expr::CXXInheritedCtorInitExprClass:
-  case Expr::CXXStdInitializerListExprClass:
-  case Expr::CXXBindTemporaryExprClass:
-  case Expr::ExprWithCleanupsClass:
-  case Expr::CXXTemporaryObjectExprClass:
-  case Expr::CXXUnresolvedConstructExprClass:
-  case Expr::CXXDependentScopeMemberExprClass:
-  case Expr::UnresolvedMemberExprClass:
-  case Expr::ObjCStringLiteralClass:
-  case Expr::ObjCBoxedExprClass:
-  case Expr::ObjCArrayLiteralClass:
-  case Expr::ObjCDictionaryLiteralClass:
-  case Expr::ObjCEncodeExprClass:
-  case Expr::ObjCMessageExprClass:
-  case Expr::ObjCSelectorExprClass:
-  case Expr::ObjCProtocolExprClass:
-  case Expr::ObjCIvarRefExprClass:
-  case Expr::ObjCPropertyRefExprClass:
-  case Expr::ObjCSubscriptRefExprClass:
-  case Expr::ObjCIsaExprClass:
-  case Expr::ObjCAvailabilityCheckExprClass:
-  case Expr::ShuffleVectorExprClass:
-  case Expr::ConvertVectorExprClass:
-  case Expr::BlockExprClass:
-  case Expr::NoStmtClass:
-  case Expr::OpaqueValueExprClass:
-  case Expr::PackExpansionExprClass:
-  case Expr::SubstNonTypeTemplateParmPackExprClass:
-  case Expr::FunctionParmPackExprClass:
-  case Expr::AsTypeExprClass:
-  case Expr::ObjCIndirectCopyRestoreExprClass:
-  case Expr::MaterializeTemporaryExprClass:
-  case Expr::PseudoObjectExprClass:
-  case Expr::AtomicExprClass:
-  case Expr::LambdaExprClass:
-  case Expr::CXXFoldExprClass:
-  case Expr::CoawaitExprClass:
-  case Expr::DependentCoawaitExprClass:
-  case Expr::CoyieldExprClass:
-    return ICEDiag(IK_NotICE, E->getBeginLoc());
-
-  case Expr::InitListExprClass: {
-    // C++03 [dcl.init]p13: If T is a scalar type, then a declaration of the
-    // form "T x = { a };" is equivalent to "T x = a;".
-    // Unless we're initializing a reference, T is a scalar as it is known to be
-    // of integral or enumeration type.
-    if (E->isRValue())
-      if (cast<InitListExpr>(E)->getNumInits() == 1)
-        return CheckICE(cast<InitListExpr>(E)->getInit(0), Ctx);
-    return ICEDiag(IK_NotICE, E->getBeginLoc());
-  }
-
-  case Expr::SizeOfPackExprClass:
-  case Expr::GNUNullExprClass:
-    // GCC considers the GNU __null value to be an integral constant expression.
-    return NoDiag();
-
-  case Expr::SubstNonTypeTemplateParmExprClass:
-    return
-      CheckICE(cast<SubstNonTypeTemplateParmExpr>(E)->getReplacement(), Ctx);
-
-  case Expr::ConstantExprClass:
-    return CheckICE(cast<ConstantExpr>(E)->getSubExpr(), Ctx);
-
-  case Expr::ParenExprClass:
-    return CheckICE(cast<ParenExpr>(E)->getSubExpr(), Ctx);
-  case Expr::GenericSelectionExprClass:
-    return CheckICE(cast<GenericSelectionExpr>(E)->getResultExpr(), Ctx);
-  case Expr::IntegerLiteralClass:
-  case Expr::FixedPointLiteralClass:
-  case Expr::CharacterLiteralClass:
-  case Expr::ObjCBoolLiteralExprClass:
-  case Expr::CXXBoolLiteralExprClass:
-  case Expr::CXXScalarValueInitExprClass:
-  case Expr::TypeTraitExprClass:
-  case Expr::ArrayTypeTraitExprClass:
-  case Expr::ExpressionTraitExprClass:
-  case Expr::CXXNoexceptExprClass:
-    return NoDiag();
-  case Expr::CallExprClass:
-  case Expr::CXXOperatorCallExprClass: {
-    // C99 6.6/3 allows function calls within unevaluated subexpressions of
-    // constant expressions, but they can never be ICEs because an ICE cannot
-    // contain an operand of (pointer to) function type.
-    const CallExpr *CE = cast<CallExpr>(E);
-    if (CE->getBuiltinCallee())
-      return CheckEvalInICE(E, Ctx);
-    return ICEDiag(IK_NotICE, E->getBeginLoc());
-  }
-  case Expr::DeclRefExprClass: {
-    if (isa<EnumConstantDecl>(cast<DeclRefExpr>(E)->getDecl()))
-      return NoDiag();
-    const ValueDecl *D = cast<DeclRefExpr>(E)->getDecl();
-    if (Ctx.getLangOpts().CPlusPlus &&
-        D && IsConstNonVolatile(D->getType())) {
-      // Parameter variables are never constants.  Without this check,
-      // getAnyInitializer() can find a default argument, which leads
-      // to chaos.
-      if (isa<ParmVarDecl>(D))
-        return ICEDiag(IK_NotICE, cast<DeclRefExpr>(E)->getLocation());
-
-      // C++ 7.1.5.1p2
-      //   A variable of non-volatile const-qualified integral or enumeration
-      //   type initialized by an ICE can be used in ICEs.
-      if (const VarDecl *Dcl = dyn_cast<VarDecl>(D)) {
-        if (!Dcl->getType()->isIntegralOrEnumerationType())
-          return ICEDiag(IK_NotICE, cast<DeclRefExpr>(E)->getLocation());
-
-        const VarDecl *VD;
-        // Look for a declaration of this variable that has an initializer, and
-        // check whether it is an ICE.
-        if (Dcl->getAnyInitializer(VD) && VD->checkInitIsICE())
-          return NoDiag();
-        else
-          return ICEDiag(IK_NotICE, cast<DeclRefExpr>(E)->getLocation());
-      }
-    }
-    return ICEDiag(IK_NotICE, E->getBeginLoc());
-  }
-  case Expr::UnaryOperatorClass: {
-    const UnaryOperator *Exp = cast<UnaryOperator>(E);
-    switch (Exp->getOpcode()) {
-    case UO_PostInc:
-    case UO_PostDec:
-    case UO_PreInc:
-    case UO_PreDec:
-    case UO_AddrOf:
-    case UO_Deref:
-    case UO_Coawait:
-      // C99 6.6/3 allows increment and decrement within unevaluated
-      // subexpressions of constant expressions, but they can never be ICEs
-      // because an ICE cannot contain an lvalue operand.
-      return ICEDiag(IK_NotICE, E->getBeginLoc());
-    case UO_Extension:
-    case UO_LNot:
-    case UO_Plus:
-    case UO_Minus:
-    case UO_Not:
-    case UO_Real:
-    case UO_Imag:
-      return CheckICE(Exp->getSubExpr(), Ctx);
-    }
-    llvm_unreachable("invalid unary operator class");
-  }
-  case Expr::OffsetOfExprClass: {
-    // Note that per C99, offsetof must be an ICE. And AFAIK, using
-    // EvaluateAsRValue matches the proposed gcc behavior for cases like
-    // "offsetof(struct s{int x[4];}, x[1.0])".  This doesn't affect
-    // compliance: we should warn earlier for offsetof expressions with
-    // array subscripts that aren't ICEs, and if the array subscripts
-    // are ICEs, the value of the offsetof must be an integer constant.
-    return CheckEvalInICE(E, Ctx);
-  }
-  case Expr::UnaryExprOrTypeTraitExprClass: {
-    const UnaryExprOrTypeTraitExpr *Exp = cast<UnaryExprOrTypeTraitExpr>(E);
-    if ((Exp->getKind() ==  UETT_SizeOf) &&
-        Exp->getTypeOfArgument()->isVariableArrayType())
-      return ICEDiag(IK_NotICE, E->getBeginLoc());
-    return NoDiag();
-  }
-  case Expr::BinaryOperatorClass: {
-    const BinaryOperator *Exp = cast<BinaryOperator>(E);
-    switch (Exp->getOpcode()) {
-    case BO_PtrMemD:
-    case BO_PtrMemI:
-    case BO_Assign:
-    case BO_MulAssign:
-    case BO_DivAssign:
-    case BO_RemAssign:
-    case BO_AddAssign:
-    case BO_SubAssign:
-    case BO_ShlAssign:
-    case BO_ShrAssign:
-    case BO_AndAssign:
-    case BO_XorAssign:
-    case BO_OrAssign:
-      // C99 6.6/3 allows assignments within unevaluated subexpressions of
-      // constant expressions, but they can never be ICEs because an ICE cannot
-      // contain an lvalue operand.
-      return ICEDiag(IK_NotICE, E->getBeginLoc());
-
-    case BO_Mul:
-    case BO_Div:
-    case BO_Rem:
-    case BO_Add:
-    case BO_Sub:
-    case BO_Shl:
-    case BO_Shr:
-    case BO_LT:
-    case BO_GT:
-    case BO_LE:
-    case BO_GE:
-    case BO_EQ:
-    case BO_NE:
-    case BO_And:
-    case BO_Xor:
-    case BO_Or:
-    case BO_Comma:
-    case BO_Cmp: {
-      ICEDiag LHSResult = CheckICE(Exp->getLHS(), Ctx);
-      ICEDiag RHSResult = CheckICE(Exp->getRHS(), Ctx);
-      if (Exp->getOpcode() == BO_Div ||
-          Exp->getOpcode() == BO_Rem) {
-        // EvaluateAsRValue gives an error for undefined Div/Rem, so make sure
-        // we don't evaluate one.
-        if (LHSResult.Kind == IK_ICE && RHSResult.Kind == IK_ICE) {
-          llvm::APSInt REval = Exp->getRHS()->EvaluateKnownConstInt(Ctx);
-          if (REval == 0)
-            return ICEDiag(IK_ICEIfUnevaluated, E->getBeginLoc());
-          if (REval.isSigned() && REval.isAllOnesValue()) {
-            llvm::APSInt LEval = Exp->getLHS()->EvaluateKnownConstInt(Ctx);
-            if (LEval.isMinSignedValue())
-              return ICEDiag(IK_ICEIfUnevaluated, E->getBeginLoc());
-          }
-        }
-      }
-      if (Exp->getOpcode() == BO_Comma) {
-        if (Ctx.getLangOpts().C99) {
-          // C99 6.6p3 introduces a strange edge case: comma can be in an ICE
-          // if it isn't evaluated.
-          if (LHSResult.Kind == IK_ICE && RHSResult.Kind == IK_ICE)
-            return ICEDiag(IK_ICEIfUnevaluated, E->getBeginLoc());
-        } else {
-          // In both C89 and C++, commas in ICEs are illegal.
-          return ICEDiag(IK_NotICE, E->getBeginLoc());
-        }
-      }
-      return Worst(LHSResult, RHSResult);
-    }
-    case BO_LAnd:
-    case BO_LOr: {
-      ICEDiag LHSResult = CheckICE(Exp->getLHS(), Ctx);
-      ICEDiag RHSResult = CheckICE(Exp->getRHS(), Ctx);
-      if (LHSResult.Kind == IK_ICE && RHSResult.Kind == IK_ICEIfUnevaluated) {
-        // Rare case where the RHS has a comma "side-effect"; we need
-        // to actually check the condition to see whether the side
-        // with the comma is evaluated.
-        if ((Exp->getOpcode() == BO_LAnd) !=
-            (Exp->getLHS()->EvaluateKnownConstInt(Ctx) == 0))
-          return RHSResult;
-        return NoDiag();
-      }
-
-      return Worst(LHSResult, RHSResult);
-    }
-    }
-    llvm_unreachable("invalid binary operator kind");
-  }
-  case Expr::ImplicitCastExprClass:
-  case Expr::CStyleCastExprClass:
-  case Expr::CXXFunctionalCastExprClass:
-  case Expr::CXXStaticCastExprClass:
-  case Expr::CXXReinterpretCastExprClass:
-  case Expr::CXXConstCastExprClass:
-  case Expr::ObjCBridgedCastExprClass: {
-    const Expr *SubExpr = cast<CastExpr>(E)->getSubExpr();
-    if (isa<ExplicitCastExpr>(E)) {
-      if (const FloatingLiteral *FL
-            = dyn_cast<FloatingLiteral>(SubExpr->IgnoreParenImpCasts())) {
-        unsigned DestWidth = Ctx.getIntWidth(E->getType());
-        bool DestSigned = E->getType()->isSignedIntegerOrEnumerationType();
-        APSInt IgnoredVal(DestWidth, !DestSigned);
-        bool Ignored;
-        // If the value does not fit in the destination type, the behavior is
-        // undefined, so we are not required to treat it as a constant
-        // expression.
-        if (FL->getValue().convertToInteger(IgnoredVal,
-                                            llvm::APFloat::rmTowardZero,
-                                            &Ignored) & APFloat::opInvalidOp)
-          return ICEDiag(IK_NotICE, E->getBeginLoc());
-        return NoDiag();
-      }
-    }
-    switch (cast<CastExpr>(E)->getCastKind()) {
-    case CK_LValueToRValue:
-    case CK_AtomicToNonAtomic:
-    case CK_NonAtomicToAtomic:
-    case CK_NoOp:
-    case CK_IntegralToBoolean:
-    case CK_IntegralCast:
-      return CheckICE(SubExpr, Ctx);
-    default:
-      return ICEDiag(IK_NotICE, E->getBeginLoc());
-    }
-  }
-  case Expr::BinaryConditionalOperatorClass: {
-    const BinaryConditionalOperator *Exp = cast<BinaryConditionalOperator>(E);
-    ICEDiag CommonResult = CheckICE(Exp->getCommon(), Ctx);
-    if (CommonResult.Kind == IK_NotICE) return CommonResult;
-    ICEDiag FalseResult = CheckICE(Exp->getFalseExpr(), Ctx);
-    if (FalseResult.Kind == IK_NotICE) return FalseResult;
-    if (CommonResult.Kind == IK_ICEIfUnevaluated) return CommonResult;
-    if (FalseResult.Kind == IK_ICEIfUnevaluated &&
-        Exp->getCommon()->EvaluateKnownConstInt(Ctx) != 0) return NoDiag();
-    return FalseResult;
-  }
-  case Expr::ConditionalOperatorClass: {
-    const ConditionalOperator *Exp = cast<ConditionalOperator>(E);
-    // If the condition (ignoring parens) is a __builtin_constant_p call,
-    // then only the true side is actually considered in an integer constant
-    // expression, and it is fully evaluated.  This is an important GNU
-    // extension.  See GCC PR38377 for discussion.
-    if (const CallExpr *CallCE
-        = dyn_cast<CallExpr>(Exp->getCond()->IgnoreParenCasts()))
-      if (CallCE->getBuiltinCallee() == Builtin::BI__builtin_constant_p)
-        return CheckEvalInICE(E, Ctx);
-    ICEDiag CondResult = CheckICE(Exp->getCond(), Ctx);
-    if (CondResult.Kind == IK_NotICE)
-      return CondResult;
-
-    ICEDiag TrueResult = CheckICE(Exp->getTrueExpr(), Ctx);
-    ICEDiag FalseResult = CheckICE(Exp->getFalseExpr(), Ctx);
-
-    if (TrueResult.Kind == IK_NotICE)
-      return TrueResult;
-    if (FalseResult.Kind == IK_NotICE)
-      return FalseResult;
-    if (CondResult.Kind == IK_ICEIfUnevaluated)
-      return CondResult;
-    if (TrueResult.Kind == IK_ICE && FalseResult.Kind == IK_ICE)
-      return NoDiag();
-    // Rare case where the diagnostics depend on which side is evaluated
-    // Note that if we get here, CondResult is 0, and at least one of
-    // TrueResult and FalseResult is non-zero.
-    if (Exp->getCond()->EvaluateKnownConstInt(Ctx) == 0)
-      return FalseResult;
-    return TrueResult;
-  }
-  case Expr::CXXDefaultArgExprClass:
-    return CheckICE(cast<CXXDefaultArgExpr>(E)->getExpr(), Ctx);
-  case Expr::CXXDefaultInitExprClass:
-    return CheckICE(cast<CXXDefaultInitExpr>(E)->getExpr(), Ctx);
-  case Expr::ChooseExprClass: {
-    return CheckICE(cast<ChooseExpr>(E)->getChosenSubExpr(), Ctx);
-  }
-  }
-
-  llvm_unreachable("Invalid StmtClass!");
-}
-
-/// Evaluate an expression as a C++11 integral constant expression.
-static bool EvaluateCPlusPlus11IntegralConstantExpr(const ASTContext &Ctx,
-                                                    const Expr *E,
-                                                    llvm::APSInt *Value,
-                                                    SourceLocation *Loc) {
-  if (!E->getType()->isIntegralOrUnscopedEnumerationType()) {
-    if (Loc) *Loc = E->getExprLoc();
-    return false;
-  }
-
-  APValue Result;
-  if (!E->isCXX11ConstantExpr(Ctx, &Result, Loc))
-    return false;
-
-  if (!Result.isInt()) {
-    if (Loc) *Loc = E->getExprLoc();
-    return false;
-  }
-
-  if (Value) *Value = Result.getInt();
-  return true;
-}
-
-bool Expr::isIntegerConstantExpr(const ASTContext &Ctx,
-                                 SourceLocation *Loc) const {
-  if (Ctx.getLangOpts().CPlusPlus11)
-    return EvaluateCPlusPlus11IntegralConstantExpr(Ctx, this, nullptr, Loc);
-
-  ICEDiag D = CheckICE(this, Ctx);
-  if (D.Kind != IK_ICE) {
-    if (Loc) *Loc = D.Loc;
-    return false;
-  }
-  return true;
-}
-
-bool Expr::isIntegerConstantExpr(llvm::APSInt &Value, const ASTContext &Ctx,
-                                 SourceLocation *Loc, bool isEvaluated) const {
-  if (Ctx.getLangOpts().CPlusPlus11)
-    return EvaluateCPlusPlus11IntegralConstantExpr(Ctx, this, &Value, Loc);
-
-  if (!isIntegerConstantExpr(Ctx, Loc))
-    return false;
-
-  // The only possible side-effects here are due to UB discovered in the
-  // evaluation (for instance, INT_MAX + 1). In such a case, we are still
-  // required to treat the expression as an ICE, so we produce the folded
-  // value.
-  EvalResult ExprResult;
-  Expr::EvalStatus Status;
-  EvalInfo Info(Ctx, Status, EvalInfo::EM_IgnoreSideEffects);
-  Info.InConstantContext = true;
-
-  if (!::EvaluateAsInt(this, ExprResult, Ctx, SE_AllowSideEffects, Info))
-    llvm_unreachable("ICE cannot be evaluated!");
-
-  Value = ExprResult.Val.getInt();
-  return true;
-}
-
-bool Expr::isCXX98IntegralConstantExpr(const ASTContext &Ctx) const {
-  return CheckICE(this, Ctx).Kind == IK_ICE;
-}
-
-bool Expr::isCXX11ConstantExpr(const ASTContext &Ctx, APValue *Result,
-                               SourceLocation *Loc) const {
-  // We support this checking in C++98 mode in order to diagnose compatibility
-  // issues.
-  assert(Ctx.getLangOpts().CPlusPlus);
-
-  // Build evaluation settings.
-  Expr::EvalStatus Status;
-  SmallVector<PartialDiagnosticAt, 8> Diags;
-  Status.Diag = &Diags;
-  EvalInfo Info(Ctx, Status, EvalInfo::EM_ConstantExpression);
-
-  APValue Scratch;
-  bool IsConstExpr = ::EvaluateAsRValue(Info, this, Result ? *Result : Scratch);
-
-  if (!Diags.empty()) {
-    IsConstExpr = false;
-    if (Loc) *Loc = Diags[0].first;
-  } else if (!IsConstExpr) {
-    // FIXME: This shouldn't happen.
-    if (Loc) *Loc = getExprLoc();
-  }
-
-  return IsConstExpr;
-}
-
-bool Expr::EvaluateWithSubstitution(APValue &Value, ASTContext &Ctx,
-                                    const FunctionDecl *Callee,
-                                    ArrayRef<const Expr*> Args,
-                                    const Expr *This) const {
-  Expr::EvalStatus Status;
-  EvalInfo Info(Ctx, Status, EvalInfo::EM_ConstantExpressionUnevaluated);
-  Info.InConstantContext = true;
-
-  LValue ThisVal;
-  const LValue *ThisPtr = nullptr;
-  if (This) {
-#ifndef NDEBUG
-    auto *MD = dyn_cast<CXXMethodDecl>(Callee);
-    assert(MD && "Don't provide `this` for non-methods.");
-    assert(!MD->isStatic() && "Don't provide `this` for static methods.");
-#endif
-    if (EvaluateObjectArgument(Info, This, ThisVal))
-      ThisPtr = &ThisVal;
-    if (Info.EvalStatus.HasSideEffects)
-      return false;
-  }
-
-  ArgVector ArgValues(Args.size());
-  for (ArrayRef<const Expr*>::iterator I = Args.begin(), E = Args.end();
-       I != E; ++I) {
-    if ((*I)->isValueDependent() ||
-        !Evaluate(ArgValues[I - Args.begin()], Info, *I))
-      // If evaluation fails, throw away the argument entirely.
-      ArgValues[I - Args.begin()] = APValue();
-    if (Info.EvalStatus.HasSideEffects)
-      return false;
-  }
-
-  // Build fake call to Callee.
-  CallStackFrame Frame(Info, Callee->getLocation(), Callee, ThisPtr,
-                       ArgValues.data());
-  return Evaluate(Value, Info, this) && !Info.EvalStatus.HasSideEffects;
-}
-
-bool Expr::isPotentialConstantExpr(const FunctionDecl *FD,
-                                   SmallVectorImpl<
-                                     PartialDiagnosticAt> &Diags) {
-  // FIXME: It would be useful to check constexpr function templates, but at the
-  // moment the constant expression evaluator cannot cope with the non-rigorous
-  // ASTs which we build for dependent expressions.
-  if (FD->isDependentContext())
-    return true;
-
-  Expr::EvalStatus Status;
-  Status.Diag = &Diags;
-
-  EvalInfo Info(FD->getASTContext(), Status,
-                EvalInfo::EM_PotentialConstantExpression);
-  Info.InConstantContext = true;
-
-  const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD);
-  const CXXRecordDecl *RD = MD ? MD->getParent()->getCanonicalDecl() : nullptr;
-
-  // Fabricate an arbitrary expression on the stack and pretend that it
-  // is a temporary being used as the 'this' pointer.
-  LValue This;
-  ImplicitValueInitExpr VIE(RD ? Info.Ctx.getRecordType(RD) : Info.Ctx.IntTy);
-  This.set({&VIE, Info.CurrentCall->Index});
-
-  ArrayRef<const Expr*> Args;
-
-  APValue Scratch;
-  if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(FD)) {
-    // Evaluate the call as a constant initializer, to allow the construction
-    // of objects of non-literal types.
-    Info.setEvaluatingDecl(This.getLValueBase(), Scratch);
-    HandleConstructorCall(&VIE, This, Args, CD, Info, Scratch);
-  } else {
-    SourceLocation Loc = FD->getLocation();
-    HandleFunctionCall(Loc, FD, (MD && MD->isInstance()) ? &This : nullptr,
-                       Args, FD->getBody(), Info, Scratch, nullptr);
-  }
-
-  return Diags.empty();
-}
-
-bool Expr::isPotentialConstantExprUnevaluated(Expr *E,
-                                              const FunctionDecl *FD,
-                                              SmallVectorImpl<
-                                                PartialDiagnosticAt> &Diags) {
-  Expr::EvalStatus Status;
-  Status.Diag = &Diags;
-
-  EvalInfo Info(FD->getASTContext(), Status,
-                EvalInfo::EM_PotentialConstantExpressionUnevaluated);
-  Info.InConstantContext = true;
-
-  // Fabricate a call stack frame to give the arguments a plausible cover story.
-  ArrayRef<const Expr*> Args;
-  ArgVector ArgValues(0);
-  bool Success = EvaluateArgs(Args, ArgValues, Info);
-  (void)Success;
-  assert(Success &&
-         "Failed to set up arguments for potential constant evaluation");
-  CallStackFrame Frame(Info, SourceLocation(), FD, nullptr, ArgValues.data());
-
-  APValue ResultScratch;
-  Evaluate(ResultScratch, Info, E);
-  return Diags.empty();
-}
-
-bool Expr::tryEvaluateObjectSize(uint64_t &Result, ASTContext &Ctx,
-                                 unsigned Type) const {
-  if (!getType()->isPointerType())
-    return false;
-
-  Expr::EvalStatus Status;
-  EvalInfo Info(Ctx, Status, EvalInfo::EM_ConstantFold);
-  return tryEvaluateBuiltinObjectSize(this, Type, Info, Result);
-}