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      1 //===--- APValue.cpp - Union class for APFloat/APSInt/Complex -------------===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 //
     10 //  This file implements the APValue class.
     11 //
     12 //===----------------------------------------------------------------------===//
     13 
     14 #include "clang/AST/APValue.h"
     15 #include "clang/AST/ASTContext.h"
     16 #include "clang/AST/CharUnits.h"
     17 #include "clang/AST/DeclCXX.h"
     18 #include "clang/AST/Expr.h"
     19 #include "clang/AST/Type.h"
     20 #include "clang/Basic/Diagnostic.h"
     21 #include "llvm/ADT/SmallString.h"
     22 #include "llvm/Support/ErrorHandling.h"
     23 #include "llvm/Support/raw_ostream.h"
     24 using namespace clang;
     25 
     26 namespace {
     27   struct LVBase {
     28     llvm::PointerIntPair<APValue::LValueBase, 1, bool> BaseAndIsOnePastTheEnd;
     29     CharUnits Offset;
     30     unsigned PathLength;
     31     unsigned CallIndex;
     32   };
     33 }
     34 
     35 struct APValue::LV : LVBase {
     36   static const unsigned InlinePathSpace =
     37       (DataSize - sizeof(LVBase)) / sizeof(LValuePathEntry);
     38 
     39   /// Path - The sequence of base classes, fields and array indices to follow to
     40   /// walk from Base to the subobject. When performing GCC-style folding, there
     41   /// may not be such a path.
     42   union {
     43     LValuePathEntry Path[InlinePathSpace];
     44     LValuePathEntry *PathPtr;
     45   };
     46 
     47   LV() { PathLength = (unsigned)-1; }
     48   ~LV() { resizePath(0); }
     49 
     50   void resizePath(unsigned Length) {
     51     if (Length == PathLength)
     52       return;
     53     if (hasPathPtr())
     54       delete [] PathPtr;
     55     PathLength = Length;
     56     if (hasPathPtr())
     57       PathPtr = new LValuePathEntry[Length];
     58   }
     59 
     60   bool hasPath() const { return PathLength != (unsigned)-1; }
     61   bool hasPathPtr() const { return hasPath() && PathLength > InlinePathSpace; }
     62 
     63   LValuePathEntry *getPath() { return hasPathPtr() ? PathPtr : Path; }
     64   const LValuePathEntry *getPath() const {
     65     return hasPathPtr() ? PathPtr : Path;
     66   }
     67 };
     68 
     69 namespace {
     70   struct MemberPointerBase {
     71     llvm::PointerIntPair<const ValueDecl*, 1, bool> MemberAndIsDerivedMember;
     72     unsigned PathLength;
     73   };
     74 }
     75 
     76 struct APValue::MemberPointerData : MemberPointerBase {
     77   static const unsigned InlinePathSpace =
     78       (DataSize - sizeof(MemberPointerBase)) / sizeof(const CXXRecordDecl*);
     79   typedef const CXXRecordDecl *PathElem;
     80   union {
     81     PathElem Path[InlinePathSpace];
     82     PathElem *PathPtr;
     83   };
     84 
     85   MemberPointerData() { PathLength = 0; }
     86   ~MemberPointerData() { resizePath(0); }
     87 
     88   void resizePath(unsigned Length) {
     89     if (Length == PathLength)
     90       return;
     91     if (hasPathPtr())
     92       delete [] PathPtr;
     93     PathLength = Length;
     94     if (hasPathPtr())
     95       PathPtr = new PathElem[Length];
     96   }
     97 
     98   bool hasPathPtr() const { return PathLength > InlinePathSpace; }
     99 
    100   PathElem *getPath() { return hasPathPtr() ? PathPtr : Path; }
    101   const PathElem *getPath() const {
    102     return hasPathPtr() ? PathPtr : Path;
    103   }
    104 };
    105 
    106 // FIXME: Reduce the malloc traffic here.
    107 
    108 APValue::Arr::Arr(unsigned NumElts, unsigned Size) :
    109   Elts(new APValue[NumElts + (NumElts != Size ? 1 : 0)]),
    110   NumElts(NumElts), ArrSize(Size) {}
    111 APValue::Arr::~Arr() { delete [] Elts; }
    112 
    113 APValue::StructData::StructData(unsigned NumBases, unsigned NumFields) :
    114   Elts(new APValue[NumBases+NumFields]),
    115   NumBases(NumBases), NumFields(NumFields) {}
    116 APValue::StructData::~StructData() {
    117   delete [] Elts;
    118 }
    119 
    120 APValue::UnionData::UnionData() : Field(nullptr), Value(new APValue) {}
    121 APValue::UnionData::~UnionData () {
    122   delete Value;
    123 }
    124 
    125 APValue::APValue(const APValue &RHS) : Kind(Uninitialized) {
    126   switch (RHS.getKind()) {
    127   case Uninitialized:
    128     break;
    129   case Int:
    130     MakeInt();
    131     setInt(RHS.getInt());
    132     break;
    133   case Float:
    134     MakeFloat();
    135     setFloat(RHS.getFloat());
    136     break;
    137   case Vector:
    138     MakeVector();
    139     setVector(((const Vec *)(const char *)RHS.Data.buffer)->Elts,
    140               RHS.getVectorLength());
    141     break;
    142   case ComplexInt:
    143     MakeComplexInt();
    144     setComplexInt(RHS.getComplexIntReal(), RHS.getComplexIntImag());
    145     break;
    146   case ComplexFloat:
    147     MakeComplexFloat();
    148     setComplexFloat(RHS.getComplexFloatReal(), RHS.getComplexFloatImag());
    149     break;
    150   case LValue:
    151     MakeLValue();
    152     if (RHS.hasLValuePath())
    153       setLValue(RHS.getLValueBase(), RHS.getLValueOffset(), RHS.getLValuePath(),
    154                 RHS.isLValueOnePastTheEnd(), RHS.getLValueCallIndex());
    155     else
    156       setLValue(RHS.getLValueBase(), RHS.getLValueOffset(), NoLValuePath(),
    157                 RHS.getLValueCallIndex());
    158     break;
    159   case Array:
    160     MakeArray(RHS.getArrayInitializedElts(), RHS.getArraySize());
    161     for (unsigned I = 0, N = RHS.getArrayInitializedElts(); I != N; ++I)
    162       getArrayInitializedElt(I) = RHS.getArrayInitializedElt(I);
    163     if (RHS.hasArrayFiller())
    164       getArrayFiller() = RHS.getArrayFiller();
    165     break;
    166   case Struct:
    167     MakeStruct(RHS.getStructNumBases(), RHS.getStructNumFields());
    168     for (unsigned I = 0, N = RHS.getStructNumBases(); I != N; ++I)
    169       getStructBase(I) = RHS.getStructBase(I);
    170     for (unsigned I = 0, N = RHS.getStructNumFields(); I != N; ++I)
    171       getStructField(I) = RHS.getStructField(I);
    172     break;
    173   case Union:
    174     MakeUnion();
    175     setUnion(RHS.getUnionField(), RHS.getUnionValue());
    176     break;
    177   case MemberPointer:
    178     MakeMemberPointer(RHS.getMemberPointerDecl(),
    179                       RHS.isMemberPointerToDerivedMember(),
    180                       RHS.getMemberPointerPath());
    181     break;
    182   case AddrLabelDiff:
    183     MakeAddrLabelDiff();
    184     setAddrLabelDiff(RHS.getAddrLabelDiffLHS(), RHS.getAddrLabelDiffRHS());
    185     break;
    186   }
    187 }
    188 
    189 void APValue::DestroyDataAndMakeUninit() {
    190   if (Kind == Int)
    191     ((APSInt*)(char*)Data.buffer)->~APSInt();
    192   else if (Kind == Float)
    193     ((APFloat*)(char*)Data.buffer)->~APFloat();
    194   else if (Kind == Vector)
    195     ((Vec*)(char*)Data.buffer)->~Vec();
    196   else if (Kind == ComplexInt)
    197     ((ComplexAPSInt*)(char*)Data.buffer)->~ComplexAPSInt();
    198   else if (Kind == ComplexFloat)
    199     ((ComplexAPFloat*)(char*)Data.buffer)->~ComplexAPFloat();
    200   else if (Kind == LValue)
    201     ((LV*)(char*)Data.buffer)->~LV();
    202   else if (Kind == Array)
    203     ((Arr*)(char*)Data.buffer)->~Arr();
    204   else if (Kind == Struct)
    205     ((StructData*)(char*)Data.buffer)->~StructData();
    206   else if (Kind == Union)
    207     ((UnionData*)(char*)Data.buffer)->~UnionData();
    208   else if (Kind == MemberPointer)
    209     ((MemberPointerData*)(char*)Data.buffer)->~MemberPointerData();
    210   else if (Kind == AddrLabelDiff)
    211     ((AddrLabelDiffData*)(char*)Data.buffer)->~AddrLabelDiffData();
    212   Kind = Uninitialized;
    213 }
    214 
    215 bool APValue::needsCleanup() const {
    216   switch (getKind()) {
    217   case Uninitialized:
    218   case AddrLabelDiff:
    219     return false;
    220   case Struct:
    221   case Union:
    222   case Array:
    223   case Vector:
    224     return true;
    225   case Int:
    226     return getInt().needsCleanup();
    227   case Float:
    228     return getFloat().needsCleanup();
    229   case ComplexFloat:
    230     assert(getComplexFloatImag().needsCleanup() ==
    231                getComplexFloatReal().needsCleanup() &&
    232            "In _Complex float types, real and imaginary values always have the "
    233            "same size.");
    234     return getComplexFloatReal().needsCleanup();
    235   case ComplexInt:
    236     assert(getComplexIntImag().needsCleanup() ==
    237                getComplexIntReal().needsCleanup() &&
    238            "In _Complex int types, real and imaginary values must have the "
    239            "same size.");
    240     return getComplexIntReal().needsCleanup();
    241   case LValue:
    242     return reinterpret_cast<const LV *>(Data.buffer)->hasPathPtr();
    243   case MemberPointer:
    244     return reinterpret_cast<const MemberPointerData *>(Data.buffer)
    245         ->hasPathPtr();
    246   }
    247   llvm_unreachable("Unknown APValue kind!");
    248 }
    249 
    250 void APValue::swap(APValue &RHS) {
    251   std::swap(Kind, RHS.Kind);
    252   char TmpData[DataSize];
    253   memcpy(TmpData, Data.buffer, DataSize);
    254   memcpy(Data.buffer, RHS.Data.buffer, DataSize);
    255   memcpy(RHS.Data.buffer, TmpData, DataSize);
    256 }
    257 
    258 LLVM_DUMP_METHOD void APValue::dump() const {
    259   dump(llvm::errs());
    260   llvm::errs() << '\n';
    261 }
    262 
    263 static double GetApproxValue(const llvm::APFloat &F) {
    264   llvm::APFloat V = F;
    265   bool ignored;
    266   V.convert(llvm::APFloat::IEEEdouble, llvm::APFloat::rmNearestTiesToEven,
    267             &ignored);
    268   return V.convertToDouble();
    269 }
    270 
    271 void APValue::dump(raw_ostream &OS) const {
    272   switch (getKind()) {
    273   case Uninitialized:
    274     OS << "Uninitialized";
    275     return;
    276   case Int:
    277     OS << "Int: " << getInt();
    278     return;
    279   case Float:
    280     OS << "Float: " << GetApproxValue(getFloat());
    281     return;
    282   case Vector:
    283     OS << "Vector: ";
    284     getVectorElt(0).dump(OS);
    285     for (unsigned i = 1; i != getVectorLength(); ++i) {
    286       OS << ", ";
    287       getVectorElt(i).dump(OS);
    288     }
    289     return;
    290   case ComplexInt:
    291     OS << "ComplexInt: " << getComplexIntReal() << ", " << getComplexIntImag();
    292     return;
    293   case ComplexFloat:
    294     OS << "ComplexFloat: " << GetApproxValue(getComplexFloatReal())
    295        << ", " << GetApproxValue(getComplexFloatImag());
    296     return;
    297   case LValue:
    298     OS << "LValue: <todo>";
    299     return;
    300   case Array:
    301     OS << "Array: ";
    302     for (unsigned I = 0, N = getArrayInitializedElts(); I != N; ++I) {
    303       getArrayInitializedElt(I).dump(OS);
    304       if (I != getArraySize() - 1) OS << ", ";
    305     }
    306     if (hasArrayFiller()) {
    307       OS << getArraySize() - getArrayInitializedElts() << " x ";
    308       getArrayFiller().dump(OS);
    309     }
    310     return;
    311   case Struct:
    312     OS << "Struct ";
    313     if (unsigned N = getStructNumBases()) {
    314       OS << " bases: ";
    315       getStructBase(0).dump(OS);
    316       for (unsigned I = 1; I != N; ++I) {
    317         OS << ", ";
    318         getStructBase(I).dump(OS);
    319       }
    320     }
    321     if (unsigned N = getStructNumFields()) {
    322       OS << " fields: ";
    323       getStructField(0).dump(OS);
    324       for (unsigned I = 1; I != N; ++I) {
    325         OS << ", ";
    326         getStructField(I).dump(OS);
    327       }
    328     }
    329     return;
    330   case Union:
    331     OS << "Union: ";
    332     getUnionValue().dump(OS);
    333     return;
    334   case MemberPointer:
    335     OS << "MemberPointer: <todo>";
    336     return;
    337   case AddrLabelDiff:
    338     OS << "AddrLabelDiff: <todo>";
    339     return;
    340   }
    341   llvm_unreachable("Unknown APValue kind!");
    342 }
    343 
    344 void APValue::printPretty(raw_ostream &Out, ASTContext &Ctx, QualType Ty) const{
    345   switch (getKind()) {
    346   case APValue::Uninitialized:
    347     Out << "<uninitialized>";
    348     return;
    349   case APValue::Int:
    350     if (Ty->isBooleanType())
    351       Out << (getInt().getBoolValue() ? "true" : "false");
    352     else
    353       Out << getInt();
    354     return;
    355   case APValue::Float:
    356     Out << GetApproxValue(getFloat());
    357     return;
    358   case APValue::Vector: {
    359     Out << '{';
    360     QualType ElemTy = Ty->getAs<VectorType>()->getElementType();
    361     getVectorElt(0).printPretty(Out, Ctx, ElemTy);
    362     for (unsigned i = 1; i != getVectorLength(); ++i) {
    363       Out << ", ";
    364       getVectorElt(i).printPretty(Out, Ctx, ElemTy);
    365     }
    366     Out << '}';
    367     return;
    368   }
    369   case APValue::ComplexInt:
    370     Out << getComplexIntReal() << "+" << getComplexIntImag() << "i";
    371     return;
    372   case APValue::ComplexFloat:
    373     Out << GetApproxValue(getComplexFloatReal()) << "+"
    374         << GetApproxValue(getComplexFloatImag()) << "i";
    375     return;
    376   case APValue::LValue: {
    377     LValueBase Base = getLValueBase();
    378     if (!Base) {
    379       Out << "0";
    380       return;
    381     }
    382 
    383     bool IsReference = Ty->isReferenceType();
    384     QualType InnerTy
    385       = IsReference ? Ty.getNonReferenceType() : Ty->getPointeeType();
    386     if (InnerTy.isNull())
    387       InnerTy = Ty;
    388 
    389     if (!hasLValuePath()) {
    390       // No lvalue path: just print the offset.
    391       CharUnits O = getLValueOffset();
    392       CharUnits S = Ctx.getTypeSizeInChars(InnerTy);
    393       if (!O.isZero()) {
    394         if (IsReference)
    395           Out << "*(";
    396         if (O % S) {
    397           Out << "(char*)";
    398           S = CharUnits::One();
    399         }
    400         Out << '&';
    401       } else if (!IsReference)
    402         Out << '&';
    403 
    404       if (const ValueDecl *VD = Base.dyn_cast<const ValueDecl*>())
    405         Out << *VD;
    406       else {
    407         assert(Base.get<const Expr *>() != nullptr &&
    408                "Expecting non-null Expr");
    409         Base.get<const Expr*>()->printPretty(Out, nullptr,
    410                                              Ctx.getPrintingPolicy());
    411       }
    412 
    413       if (!O.isZero()) {
    414         Out << " + " << (O / S);
    415         if (IsReference)
    416           Out << ')';
    417       }
    418       return;
    419     }
    420 
    421     // We have an lvalue path. Print it out nicely.
    422     if (!IsReference)
    423       Out << '&';
    424     else if (isLValueOnePastTheEnd())
    425       Out << "*(&";
    426 
    427     QualType ElemTy;
    428     if (const ValueDecl *VD = Base.dyn_cast<const ValueDecl*>()) {
    429       Out << *VD;
    430       ElemTy = VD->getType();
    431     } else {
    432       const Expr *E = Base.get<const Expr*>();
    433       assert(E != nullptr && "Expecting non-null Expr");
    434       E->printPretty(Out, nullptr, Ctx.getPrintingPolicy());
    435       ElemTy = E->getType();
    436     }
    437 
    438     ArrayRef<LValuePathEntry> Path = getLValuePath();
    439     const CXXRecordDecl *CastToBase = nullptr;
    440     for (unsigned I = 0, N = Path.size(); I != N; ++I) {
    441       if (ElemTy->getAs<RecordType>()) {
    442         // The lvalue refers to a class type, so the next path entry is a base
    443         // or member.
    444         const Decl *BaseOrMember =
    445         BaseOrMemberType::getFromOpaqueValue(Path[I].BaseOrMember).getPointer();
    446         if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(BaseOrMember)) {
    447           CastToBase = RD;
    448           ElemTy = Ctx.getRecordType(RD);
    449         } else {
    450           const ValueDecl *VD = cast<ValueDecl>(BaseOrMember);
    451           Out << ".";
    452           if (CastToBase)
    453             Out << *CastToBase << "::";
    454           Out << *VD;
    455           ElemTy = VD->getType();
    456         }
    457       } else {
    458         // The lvalue must refer to an array.
    459         Out << '[' << Path[I].ArrayIndex << ']';
    460         ElemTy = Ctx.getAsArrayType(ElemTy)->getElementType();
    461       }
    462     }
    463 
    464     // Handle formatting of one-past-the-end lvalues.
    465     if (isLValueOnePastTheEnd()) {
    466       // FIXME: If CastToBase is non-0, we should prefix the output with
    467       // "(CastToBase*)".
    468       Out << " + 1";
    469       if (IsReference)
    470         Out << ')';
    471     }
    472     return;
    473   }
    474   case APValue::Array: {
    475     const ArrayType *AT = Ctx.getAsArrayType(Ty);
    476     QualType ElemTy = AT->getElementType();
    477     Out << '{';
    478     if (unsigned N = getArrayInitializedElts()) {
    479       getArrayInitializedElt(0).printPretty(Out, Ctx, ElemTy);
    480       for (unsigned I = 1; I != N; ++I) {
    481         Out << ", ";
    482         if (I == 10) {
    483           // Avoid printing out the entire contents of large arrays.
    484           Out << "...";
    485           break;
    486         }
    487         getArrayInitializedElt(I).printPretty(Out, Ctx, ElemTy);
    488       }
    489     }
    490     Out << '}';
    491     return;
    492   }
    493   case APValue::Struct: {
    494     Out << '{';
    495     const RecordDecl *RD = Ty->getAs<RecordType>()->getDecl();
    496     bool First = true;
    497     if (unsigned N = getStructNumBases()) {
    498       const CXXRecordDecl *CD = cast<CXXRecordDecl>(RD);
    499       CXXRecordDecl::base_class_const_iterator BI = CD->bases_begin();
    500       for (unsigned I = 0; I != N; ++I, ++BI) {
    501         assert(BI != CD->bases_end());
    502         if (!First)
    503           Out << ", ";
    504         getStructBase(I).printPretty(Out, Ctx, BI->getType());
    505         First = false;
    506       }
    507     }
    508     for (const auto *FI : RD->fields()) {
    509       if (!First)
    510         Out << ", ";
    511       if (FI->isUnnamedBitfield()) continue;
    512       getStructField(FI->getFieldIndex()).
    513         printPretty(Out, Ctx, FI->getType());
    514       First = false;
    515     }
    516     Out << '}';
    517     return;
    518   }
    519   case APValue::Union:
    520     Out << '{';
    521     if (const FieldDecl *FD = getUnionField()) {
    522       Out << "." << *FD << " = ";
    523       getUnionValue().printPretty(Out, Ctx, FD->getType());
    524     }
    525     Out << '}';
    526     return;
    527   case APValue::MemberPointer:
    528     // FIXME: This is not enough to unambiguously identify the member in a
    529     // multiple-inheritance scenario.
    530     if (const ValueDecl *VD = getMemberPointerDecl()) {
    531       Out << '&' << *cast<CXXRecordDecl>(VD->getDeclContext()) << "::" << *VD;
    532       return;
    533     }
    534     Out << "0";
    535     return;
    536   case APValue::AddrLabelDiff:
    537     Out << "&&" << getAddrLabelDiffLHS()->getLabel()->getName();
    538     Out << " - ";
    539     Out << "&&" << getAddrLabelDiffRHS()->getLabel()->getName();
    540     return;
    541   }
    542   llvm_unreachable("Unknown APValue kind!");
    543 }
    544 
    545 std::string APValue::getAsString(ASTContext &Ctx, QualType Ty) const {
    546   std::string Result;
    547   llvm::raw_string_ostream Out(Result);
    548   printPretty(Out, Ctx, Ty);
    549   Out.flush();
    550   return Result;
    551 }
    552 
    553 const APValue::LValueBase APValue::getLValueBase() const {
    554   assert(isLValue() && "Invalid accessor");
    555   return ((const LV*)(const void*)Data.buffer)->BaseAndIsOnePastTheEnd.getPointer();
    556 }
    557 
    558 bool APValue::isLValueOnePastTheEnd() const {
    559   assert(isLValue() && "Invalid accessor");
    560   return ((const LV*)(const void*)Data.buffer)->BaseAndIsOnePastTheEnd.getInt();
    561 }
    562 
    563 CharUnits &APValue::getLValueOffset() {
    564   assert(isLValue() && "Invalid accessor");
    565   return ((LV*)(void*)Data.buffer)->Offset;
    566 }
    567 
    568 bool APValue::hasLValuePath() const {
    569   assert(isLValue() && "Invalid accessor");
    570   return ((const LV*)(const char*)Data.buffer)->hasPath();
    571 }
    572 
    573 ArrayRef<APValue::LValuePathEntry> APValue::getLValuePath() const {
    574   assert(isLValue() && hasLValuePath() && "Invalid accessor");
    575   const LV &LVal = *((const LV*)(const char*)Data.buffer);
    576   return llvm::makeArrayRef(LVal.getPath(), LVal.PathLength);
    577 }
    578 
    579 unsigned APValue::getLValueCallIndex() const {
    580   assert(isLValue() && "Invalid accessor");
    581   return ((const LV*)(const char*)Data.buffer)->CallIndex;
    582 }
    583 
    584 void APValue::setLValue(LValueBase B, const CharUnits &O, NoLValuePath,
    585                         unsigned CallIndex) {
    586   assert(isLValue() && "Invalid accessor");
    587   LV &LVal = *((LV*)(char*)Data.buffer);
    588   LVal.BaseAndIsOnePastTheEnd.setPointer(B);
    589   LVal.BaseAndIsOnePastTheEnd.setInt(false);
    590   LVal.Offset = O;
    591   LVal.CallIndex = CallIndex;
    592   LVal.resizePath((unsigned)-1);
    593 }
    594 
    595 void APValue::setLValue(LValueBase B, const CharUnits &O,
    596                         ArrayRef<LValuePathEntry> Path, bool IsOnePastTheEnd,
    597                         unsigned CallIndex) {
    598   assert(isLValue() && "Invalid accessor");
    599   LV &LVal = *((LV*)(char*)Data.buffer);
    600   LVal.BaseAndIsOnePastTheEnd.setPointer(B);
    601   LVal.BaseAndIsOnePastTheEnd.setInt(IsOnePastTheEnd);
    602   LVal.Offset = O;
    603   LVal.CallIndex = CallIndex;
    604   LVal.resizePath(Path.size());
    605   memcpy(LVal.getPath(), Path.data(), Path.size() * sizeof(LValuePathEntry));
    606 }
    607 
    608 const ValueDecl *APValue::getMemberPointerDecl() const {
    609   assert(isMemberPointer() && "Invalid accessor");
    610   const MemberPointerData &MPD =
    611       *((const MemberPointerData *)(const char *)Data.buffer);
    612   return MPD.MemberAndIsDerivedMember.getPointer();
    613 }
    614 
    615 bool APValue::isMemberPointerToDerivedMember() const {
    616   assert(isMemberPointer() && "Invalid accessor");
    617   const MemberPointerData &MPD =
    618       *((const MemberPointerData *)(const char *)Data.buffer);
    619   return MPD.MemberAndIsDerivedMember.getInt();
    620 }
    621 
    622 ArrayRef<const CXXRecordDecl*> APValue::getMemberPointerPath() const {
    623   assert(isMemberPointer() && "Invalid accessor");
    624   const MemberPointerData &MPD =
    625       *((const MemberPointerData *)(const char *)Data.buffer);
    626   return llvm::makeArrayRef(MPD.getPath(), MPD.PathLength);
    627 }
    628 
    629 void APValue::MakeLValue() {
    630   assert(isUninit() && "Bad state change");
    631   static_assert(sizeof(LV) <= DataSize, "LV too big");
    632   new ((void*)(char*)Data.buffer) LV();
    633   Kind = LValue;
    634 }
    635 
    636 void APValue::MakeArray(unsigned InitElts, unsigned Size) {
    637   assert(isUninit() && "Bad state change");
    638   new ((void*)(char*)Data.buffer) Arr(InitElts, Size);
    639   Kind = Array;
    640 }
    641 
    642 void APValue::MakeMemberPointer(const ValueDecl *Member, bool IsDerivedMember,
    643                                 ArrayRef<const CXXRecordDecl*> Path) {
    644   assert(isUninit() && "Bad state change");
    645   MemberPointerData *MPD = new ((void*)(char*)Data.buffer) MemberPointerData;
    646   Kind = MemberPointer;
    647   MPD->MemberAndIsDerivedMember.setPointer(Member);
    648   MPD->MemberAndIsDerivedMember.setInt(IsDerivedMember);
    649   MPD->resizePath(Path.size());
    650   memcpy(MPD->getPath(), Path.data(), Path.size()*sizeof(const CXXRecordDecl*));
    651 }
    652