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 "llvm/Support/ErrorHandling.h"
21 #include "llvm/Support/raw_ostream.h"
22 using namespace clang;
23 
24 namespace {
25   struct LVBase {
26     llvm::PointerIntPair<APValue::LValueBase, 1, bool> BaseAndIsOnePastTheEnd;
27     CharUnits Offset;
28     unsigned PathLength;
29     unsigned CallIndex;
30     bool IsNullPtr;
31   };
32 }
33 
34 struct APValue::LV : LVBase {
35   static const unsigned InlinePathSpace =
36       (DataSize - sizeof(LVBase)) / sizeof(LValuePathEntry);
37 
38   /// Path - The sequence of base classes, fields and array indices to follow to
39   /// walk from Base to the subobject. When performing GCC-style folding, there
40   /// may not be such a path.
41   union {
42     LValuePathEntry Path[InlinePathSpace];
43     LValuePathEntry *PathPtr;
44   };
45 
46   LV() { PathLength = (unsigned)-1; }
47   ~LV() { resizePath(0); }
48 
49   void resizePath(unsigned Length) {
50     if (Length == PathLength)
51       return;
52     if (hasPathPtr())
53       delete [] PathPtr;
54     PathLength = Length;
55     if (hasPathPtr())
56       PathPtr = new LValuePathEntry[Length];
57   }
58 
59   bool hasPath() const { return PathLength != (unsigned)-1; }
60   bool hasPathPtr() const { return hasPath() && PathLength > InlinePathSpace; }
61 
62   LValuePathEntry *getPath() { return hasPathPtr() ? PathPtr : Path; }
63   const LValuePathEntry *getPath() const {
64     return hasPathPtr() ? PathPtr : Path;
65   }
66 };
67 
68 namespace {
69   struct MemberPointerBase {
70     llvm::PointerIntPair<const ValueDecl*, 1, bool> MemberAndIsDerivedMember;
71     unsigned PathLength;
72   };
73 }
74 
75 struct APValue::MemberPointerData : MemberPointerBase {
76   static const unsigned InlinePathSpace =
77       (DataSize - sizeof(MemberPointerBase)) / sizeof(const CXXRecordDecl*);
78   typedef const CXXRecordDecl *PathElem;
79   union {
80     PathElem Path[InlinePathSpace];
81     PathElem *PathPtr;
82   };
83 
84   MemberPointerData() { PathLength = 0; }
85   ~MemberPointerData() { resizePath(0); }
86 
87   void resizePath(unsigned Length) {
88     if (Length == PathLength)
89       return;
90     if (hasPathPtr())
91       delete [] PathPtr;
92     PathLength = Length;
93     if (hasPathPtr())
94       PathPtr = new PathElem[Length];
95   }
96 
97   bool hasPathPtr() const { return PathLength > InlinePathSpace; }
98 
99   PathElem *getPath() { return hasPathPtr() ? PathPtr : Path; }
100   const PathElem *getPath() const {
101     return hasPathPtr() ? PathPtr : Path;
102   }
103 };
104 
105 // FIXME: Reduce the malloc traffic here.
106 
107 APValue::Arr::Arr(unsigned NumElts, unsigned Size) :
108   Elts(new APValue[NumElts + (NumElts != Size ? 1 : 0)]),
109   NumElts(NumElts), ArrSize(Size) {}
110 APValue::Arr::~Arr() { delete [] Elts; }
111 
112 APValue::StructData::StructData(unsigned NumBases, unsigned NumFields) :
113   Elts(new APValue[NumBases+NumFields]),
114   NumBases(NumBases), NumFields(NumFields) {}
115 APValue::StructData::~StructData() {
116   delete [] Elts;
117 }
118 
119 APValue::UnionData::UnionData() : Field(nullptr), Value(new APValue) {}
120 APValue::UnionData::~UnionData () {
121   delete Value;
122 }
123 
124 APValue::APValue(const APValue &RHS) : Kind(Uninitialized) {
125   switch (RHS.getKind()) {
126   case Uninitialized:
127     break;
128   case Int:
129     MakeInt();
130     setInt(RHS.getInt());
131     break;
132   case Float:
133     MakeFloat();
134     setFloat(RHS.getFloat());
135     break;
136   case Vector:
137     MakeVector();
138     setVector(((const Vec *)(const char *)RHS.Data.buffer)->Elts,
139               RHS.getVectorLength());
140     break;
141   case ComplexInt:
142     MakeComplexInt();
143     setComplexInt(RHS.getComplexIntReal(), RHS.getComplexIntImag());
144     break;
145   case ComplexFloat:
146     MakeComplexFloat();
147     setComplexFloat(RHS.getComplexFloatReal(), RHS.getComplexFloatImag());
148     break;
149   case LValue:
150     MakeLValue();
151     if (RHS.hasLValuePath())
152       setLValue(RHS.getLValueBase(), RHS.getLValueOffset(), RHS.getLValuePath(),
153                 RHS.isLValueOnePastTheEnd(), RHS.getLValueCallIndex(),
154                 RHS.isNullPointer());
155     else
156       setLValue(RHS.getLValueBase(), RHS.getLValueOffset(), NoLValuePath(),
157                 RHS.getLValueCallIndex(), RHS.isNullPointer());
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 bool APValue::isNullPointer() const {
585   assert(isLValue() && "Invalid usage");
586   return ((const LV*)(const char*)Data.buffer)->IsNullPtr;
587 }
588 
589 void APValue::setLValue(LValueBase B, const CharUnits &O, NoLValuePath,
590                         unsigned CallIndex, bool IsNullPtr) {
591   assert(isLValue() && "Invalid accessor");
592   LV &LVal = *((LV*)(char*)Data.buffer);
593   LVal.BaseAndIsOnePastTheEnd.setPointer(B);
594   LVal.BaseAndIsOnePastTheEnd.setInt(false);
595   LVal.Offset = O;
596   LVal.CallIndex = CallIndex;
597   LVal.resizePath((unsigned)-1);
598   LVal.IsNullPtr = IsNullPtr;
599 }
600 
601 void APValue::setLValue(LValueBase B, const CharUnits &O,
602                         ArrayRef<LValuePathEntry> Path, bool IsOnePastTheEnd,
603                         unsigned CallIndex, bool IsNullPtr) {
604   assert(isLValue() && "Invalid accessor");
605   LV &LVal = *((LV*)(char*)Data.buffer);
606   LVal.BaseAndIsOnePastTheEnd.setPointer(B);
607   LVal.BaseAndIsOnePastTheEnd.setInt(IsOnePastTheEnd);
608   LVal.Offset = O;
609   LVal.CallIndex = CallIndex;
610   LVal.resizePath(Path.size());
611   memcpy(LVal.getPath(), Path.data(), Path.size() * sizeof(LValuePathEntry));
612   LVal.IsNullPtr = IsNullPtr;
613 }
614 
615 const ValueDecl *APValue::getMemberPointerDecl() const {
616   assert(isMemberPointer() && "Invalid accessor");
617   const MemberPointerData &MPD =
618       *((const MemberPointerData *)(const char *)Data.buffer);
619   return MPD.MemberAndIsDerivedMember.getPointer();
620 }
621 
622 bool APValue::isMemberPointerToDerivedMember() const {
623   assert(isMemberPointer() && "Invalid accessor");
624   const MemberPointerData &MPD =
625       *((const MemberPointerData *)(const char *)Data.buffer);
626   return MPD.MemberAndIsDerivedMember.getInt();
627 }
628 
629 ArrayRef<const CXXRecordDecl*> APValue::getMemberPointerPath() const {
630   assert(isMemberPointer() && "Invalid accessor");
631   const MemberPointerData &MPD =
632       *((const MemberPointerData *)(const char *)Data.buffer);
633   return llvm::makeArrayRef(MPD.getPath(), MPD.PathLength);
634 }
635 
636 void APValue::MakeLValue() {
637   assert(isUninit() && "Bad state change");
638   static_assert(sizeof(LV) <= DataSize, "LV too big");
639   new ((void*)(char*)Data.buffer) LV();
640   Kind = LValue;
641 }
642 
643 void APValue::MakeArray(unsigned InitElts, unsigned Size) {
644   assert(isUninit() && "Bad state change");
645   new ((void*)(char*)Data.buffer) Arr(InitElts, Size);
646   Kind = Array;
647 }
648 
649 void APValue::MakeMemberPointer(const ValueDecl *Member, bool IsDerivedMember,
650                                 ArrayRef<const CXXRecordDecl*> Path) {
651   assert(isUninit() && "Bad state change");
652   MemberPointerData *MPD = new ((void*)(char*)Data.buffer) MemberPointerData;
653   Kind = MemberPointer;
654   MPD->MemberAndIsDerivedMember.setPointer(Member);
655   MPD->MemberAndIsDerivedMember.setInt(IsDerivedMember);
656   MPD->resizePath(Path.size());
657   memcpy(MPD->getPath(), Path.data(), Path.size()*sizeof(const CXXRecordDecl*));
658 }
659