1 //===--- APValue.cpp - Union class for APFloat/APSInt/Complex -------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 //  This file implements the APValue class.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "clang/AST/APValue.h"
14 #include "clang/AST/ASTContext.h"
15 #include "clang/AST/CharUnits.h"
16 #include "clang/AST/DeclCXX.h"
17 #include "clang/AST/Expr.h"
18 #include "clang/AST/Type.h"
19 #include "llvm/Support/ErrorHandling.h"
20 #include "llvm/Support/raw_ostream.h"
21 using namespace clang;
22 
23 /// The identity of a type_info object depends on the canonical unqualified
24 /// type only.
25 TypeInfoLValue::TypeInfoLValue(const Type *T)
26     : T(T->getCanonicalTypeUnqualified().getTypePtr()) {}
27 
28 void TypeInfoLValue::print(llvm::raw_ostream &Out,
29                            const PrintingPolicy &Policy) const {
30   Out << "typeid(";
31   QualType(getType(), 0).print(Out, Policy);
32   Out << ")";
33 }
34 
35 static_assert(
36     1 << llvm::PointerLikeTypeTraits<TypeInfoLValue>::NumLowBitsAvailable <=
37         alignof(Type),
38     "Type is insufficiently aligned");
39 
40 APValue::LValueBase::LValueBase(const ValueDecl *P, unsigned I, unsigned V)
41     : Ptr(P), Local{I, V} {}
42 APValue::LValueBase::LValueBase(const Expr *P, unsigned I, unsigned V)
43     : Ptr(P), Local{I, V} {}
44 
45 APValue::LValueBase APValue::LValueBase::getDynamicAlloc(DynamicAllocLValue LV,
46                                                          QualType Type) {
47   LValueBase Base;
48   Base.Ptr = LV;
49   Base.DynamicAllocType = Type.getAsOpaquePtr();
50   return Base;
51 }
52 
53 APValue::LValueBase APValue::LValueBase::getTypeInfo(TypeInfoLValue LV,
54                                                      QualType TypeInfo) {
55   LValueBase Base;
56   Base.Ptr = LV;
57   Base.TypeInfoType = TypeInfo.getAsOpaquePtr();
58   return Base;
59 }
60 
61 unsigned APValue::LValueBase::getCallIndex() const {
62   return (is<TypeInfoLValue>() || is<DynamicAllocLValue>()) ? 0
63                                                             : Local.CallIndex;
64 }
65 
66 unsigned APValue::LValueBase::getVersion() const {
67   return (is<TypeInfoLValue>() || is<DynamicAllocLValue>()) ? 0 : Local.Version;
68 }
69 
70 QualType APValue::LValueBase::getTypeInfoType() const {
71   assert(is<TypeInfoLValue>() && "not a type_info lvalue");
72   return QualType::getFromOpaquePtr(TypeInfoType);
73 }
74 
75 QualType APValue::LValueBase::getDynamicAllocType() const {
76   assert(is<DynamicAllocLValue>() && "not a dynamic allocation lvalue");
77   return QualType::getFromOpaquePtr(DynamicAllocType);
78 }
79 
80 namespace clang {
81 bool operator==(const APValue::LValueBase &LHS,
82                 const APValue::LValueBase &RHS) {
83   if (LHS.Ptr != RHS.Ptr)
84     return false;
85   if (LHS.is<TypeInfoLValue>())
86     return true;
87   return LHS.Local.CallIndex == RHS.Local.CallIndex &&
88          LHS.Local.Version == RHS.Local.Version;
89 }
90 }
91 
92 namespace {
93   struct LVBase {
94     APValue::LValueBase Base;
95     CharUnits Offset;
96     unsigned PathLength;
97     bool IsNullPtr : 1;
98     bool IsOnePastTheEnd : 1;
99   };
100 }
101 
102 void *APValue::LValueBase::getOpaqueValue() const {
103   return Ptr.getOpaqueValue();
104 }
105 
106 bool APValue::LValueBase::isNull() const {
107   return Ptr.isNull();
108 }
109 
110 APValue::LValueBase::operator bool () const {
111   return static_cast<bool>(Ptr);
112 }
113 
114 clang::APValue::LValueBase
115 llvm::DenseMapInfo<clang::APValue::LValueBase>::getEmptyKey() {
116   return clang::APValue::LValueBase(
117       DenseMapInfo<const ValueDecl*>::getEmptyKey());
118 }
119 
120 clang::APValue::LValueBase
121 llvm::DenseMapInfo<clang::APValue::LValueBase>::getTombstoneKey() {
122   return clang::APValue::LValueBase(
123       DenseMapInfo<const ValueDecl*>::getTombstoneKey());
124 }
125 
126 namespace clang {
127 llvm::hash_code hash_value(const APValue::LValueBase &Base) {
128   if (Base.is<TypeInfoLValue>() || Base.is<DynamicAllocLValue>())
129     return llvm::hash_value(Base.getOpaqueValue());
130   return llvm::hash_combine(Base.getOpaqueValue(), Base.getCallIndex(),
131                             Base.getVersion());
132 }
133 }
134 
135 unsigned llvm::DenseMapInfo<clang::APValue::LValueBase>::getHashValue(
136     const clang::APValue::LValueBase &Base) {
137   return hash_value(Base);
138 }
139 
140 bool llvm::DenseMapInfo<clang::APValue::LValueBase>::isEqual(
141     const clang::APValue::LValueBase &LHS,
142     const clang::APValue::LValueBase &RHS) {
143   return LHS == RHS;
144 }
145 
146 struct APValue::LV : LVBase {
147   static const unsigned InlinePathSpace =
148       (DataSize - sizeof(LVBase)) / sizeof(LValuePathEntry);
149 
150   /// Path - The sequence of base classes, fields and array indices to follow to
151   /// walk from Base to the subobject. When performing GCC-style folding, there
152   /// may not be such a path.
153   union {
154     LValuePathEntry Path[InlinePathSpace];
155     LValuePathEntry *PathPtr;
156   };
157 
158   LV() { PathLength = (unsigned)-1; }
159   ~LV() { resizePath(0); }
160 
161   void resizePath(unsigned Length) {
162     if (Length == PathLength)
163       return;
164     if (hasPathPtr())
165       delete [] PathPtr;
166     PathLength = Length;
167     if (hasPathPtr())
168       PathPtr = new LValuePathEntry[Length];
169   }
170 
171   bool hasPath() const { return PathLength != (unsigned)-1; }
172   bool hasPathPtr() const { return hasPath() && PathLength > InlinePathSpace; }
173 
174   LValuePathEntry *getPath() { return hasPathPtr() ? PathPtr : Path; }
175   const LValuePathEntry *getPath() const {
176     return hasPathPtr() ? PathPtr : Path;
177   }
178 };
179 
180 namespace {
181   struct MemberPointerBase {
182     llvm::PointerIntPair<const ValueDecl*, 1, bool> MemberAndIsDerivedMember;
183     unsigned PathLength;
184   };
185 }
186 
187 struct APValue::MemberPointerData : MemberPointerBase {
188   static const unsigned InlinePathSpace =
189       (DataSize - sizeof(MemberPointerBase)) / sizeof(const CXXRecordDecl*);
190   typedef const CXXRecordDecl *PathElem;
191   union {
192     PathElem Path[InlinePathSpace];
193     PathElem *PathPtr;
194   };
195 
196   MemberPointerData() { PathLength = 0; }
197   ~MemberPointerData() { resizePath(0); }
198 
199   void resizePath(unsigned Length) {
200     if (Length == PathLength)
201       return;
202     if (hasPathPtr())
203       delete [] PathPtr;
204     PathLength = Length;
205     if (hasPathPtr())
206       PathPtr = new PathElem[Length];
207   }
208 
209   bool hasPathPtr() const { return PathLength > InlinePathSpace; }
210 
211   PathElem *getPath() { return hasPathPtr() ? PathPtr : Path; }
212   const PathElem *getPath() const {
213     return hasPathPtr() ? PathPtr : Path;
214   }
215 };
216 
217 // FIXME: Reduce the malloc traffic here.
218 
219 APValue::Arr::Arr(unsigned NumElts, unsigned Size) :
220   Elts(new APValue[NumElts + (NumElts != Size ? 1 : 0)]),
221   NumElts(NumElts), ArrSize(Size) {}
222 APValue::Arr::~Arr() { delete [] Elts; }
223 
224 APValue::StructData::StructData(unsigned NumBases, unsigned NumFields) :
225   Elts(new APValue[NumBases+NumFields]),
226   NumBases(NumBases), NumFields(NumFields) {}
227 APValue::StructData::~StructData() {
228   delete [] Elts;
229 }
230 
231 APValue::UnionData::UnionData() : Field(nullptr), Value(new APValue) {}
232 APValue::UnionData::~UnionData () {
233   delete Value;
234 }
235 
236 APValue::APValue(const APValue &RHS) : Kind(None) {
237   switch (RHS.getKind()) {
238   case None:
239   case Indeterminate:
240     Kind = RHS.getKind();
241     break;
242   case Int:
243     MakeInt();
244     setInt(RHS.getInt());
245     break;
246   case Float:
247     MakeFloat();
248     setFloat(RHS.getFloat());
249     break;
250   case FixedPoint: {
251     APFixedPoint FXCopy = RHS.getFixedPoint();
252     MakeFixedPoint(std::move(FXCopy));
253     break;
254   }
255   case Vector:
256     MakeVector();
257     setVector(((const Vec *)(const char *)RHS.Data.buffer)->Elts,
258               RHS.getVectorLength());
259     break;
260   case ComplexInt:
261     MakeComplexInt();
262     setComplexInt(RHS.getComplexIntReal(), RHS.getComplexIntImag());
263     break;
264   case ComplexFloat:
265     MakeComplexFloat();
266     setComplexFloat(RHS.getComplexFloatReal(), RHS.getComplexFloatImag());
267     break;
268   case LValue:
269     MakeLValue();
270     if (RHS.hasLValuePath())
271       setLValue(RHS.getLValueBase(), RHS.getLValueOffset(), RHS.getLValuePath(),
272                 RHS.isLValueOnePastTheEnd(), RHS.isNullPointer());
273     else
274       setLValue(RHS.getLValueBase(), RHS.getLValueOffset(), NoLValuePath(),
275                 RHS.isNullPointer());
276     break;
277   case Array:
278     MakeArray(RHS.getArrayInitializedElts(), RHS.getArraySize());
279     for (unsigned I = 0, N = RHS.getArrayInitializedElts(); I != N; ++I)
280       getArrayInitializedElt(I) = RHS.getArrayInitializedElt(I);
281     if (RHS.hasArrayFiller())
282       getArrayFiller() = RHS.getArrayFiller();
283     break;
284   case Struct:
285     MakeStruct(RHS.getStructNumBases(), RHS.getStructNumFields());
286     for (unsigned I = 0, N = RHS.getStructNumBases(); I != N; ++I)
287       getStructBase(I) = RHS.getStructBase(I);
288     for (unsigned I = 0, N = RHS.getStructNumFields(); I != N; ++I)
289       getStructField(I) = RHS.getStructField(I);
290     break;
291   case Union:
292     MakeUnion();
293     setUnion(RHS.getUnionField(), RHS.getUnionValue());
294     break;
295   case MemberPointer:
296     MakeMemberPointer(RHS.getMemberPointerDecl(),
297                       RHS.isMemberPointerToDerivedMember(),
298                       RHS.getMemberPointerPath());
299     break;
300   case AddrLabelDiff:
301     MakeAddrLabelDiff();
302     setAddrLabelDiff(RHS.getAddrLabelDiffLHS(), RHS.getAddrLabelDiffRHS());
303     break;
304   }
305 }
306 
307 APValue::APValue(APValue &&RHS) : Kind(RHS.Kind), Data(RHS.Data) {
308   RHS.Kind = None;
309 }
310 
311 APValue &APValue::operator=(const APValue &RHS) {
312   if (this != &RHS)
313     *this = APValue(RHS);
314   return *this;
315 }
316 
317 APValue &APValue::operator=(APValue &&RHS) {
318   if (Kind != None && Kind != Indeterminate)
319     DestroyDataAndMakeUninit();
320   Kind = RHS.Kind;
321   Data = RHS.Data;
322   RHS.Kind = None;
323   return *this;
324 }
325 
326 void APValue::DestroyDataAndMakeUninit() {
327   if (Kind == Int)
328     ((APSInt*)(char*)Data.buffer)->~APSInt();
329   else if (Kind == Float)
330     ((APFloat*)(char*)Data.buffer)->~APFloat();
331   else if (Kind == FixedPoint)
332     ((APFixedPoint *)(char *)Data.buffer)->~APFixedPoint();
333   else if (Kind == Vector)
334     ((Vec*)(char*)Data.buffer)->~Vec();
335   else if (Kind == ComplexInt)
336     ((ComplexAPSInt*)(char*)Data.buffer)->~ComplexAPSInt();
337   else if (Kind == ComplexFloat)
338     ((ComplexAPFloat*)(char*)Data.buffer)->~ComplexAPFloat();
339   else if (Kind == LValue)
340     ((LV*)(char*)Data.buffer)->~LV();
341   else if (Kind == Array)
342     ((Arr*)(char*)Data.buffer)->~Arr();
343   else if (Kind == Struct)
344     ((StructData*)(char*)Data.buffer)->~StructData();
345   else if (Kind == Union)
346     ((UnionData*)(char*)Data.buffer)->~UnionData();
347   else if (Kind == MemberPointer)
348     ((MemberPointerData*)(char*)Data.buffer)->~MemberPointerData();
349   else if (Kind == AddrLabelDiff)
350     ((AddrLabelDiffData*)(char*)Data.buffer)->~AddrLabelDiffData();
351   Kind = None;
352 }
353 
354 bool APValue::needsCleanup() const {
355   switch (getKind()) {
356   case None:
357   case Indeterminate:
358   case AddrLabelDiff:
359     return false;
360   case Struct:
361   case Union:
362   case Array:
363   case Vector:
364     return true;
365   case Int:
366     return getInt().needsCleanup();
367   case Float:
368     return getFloat().needsCleanup();
369   case FixedPoint:
370     return getFixedPoint().getValue().needsCleanup();
371   case ComplexFloat:
372     assert(getComplexFloatImag().needsCleanup() ==
373                getComplexFloatReal().needsCleanup() &&
374            "In _Complex float types, real and imaginary values always have the "
375            "same size.");
376     return getComplexFloatReal().needsCleanup();
377   case ComplexInt:
378     assert(getComplexIntImag().needsCleanup() ==
379                getComplexIntReal().needsCleanup() &&
380            "In _Complex int types, real and imaginary values must have the "
381            "same size.");
382     return getComplexIntReal().needsCleanup();
383   case LValue:
384     return reinterpret_cast<const LV *>(Data.buffer)->hasPathPtr();
385   case MemberPointer:
386     return reinterpret_cast<const MemberPointerData *>(Data.buffer)
387         ->hasPathPtr();
388   }
389   llvm_unreachable("Unknown APValue kind!");
390 }
391 
392 void APValue::swap(APValue &RHS) {
393   std::swap(Kind, RHS.Kind);
394   std::swap(Data, RHS.Data);
395 }
396 
397 static double GetApproxValue(const llvm::APFloat &F) {
398   llvm::APFloat V = F;
399   bool ignored;
400   V.convert(llvm::APFloat::IEEEdouble(), llvm::APFloat::rmNearestTiesToEven,
401             &ignored);
402   return V.convertToDouble();
403 }
404 
405 void APValue::printPretty(raw_ostream &Out, const ASTContext &Ctx,
406                           QualType Ty) const {
407   // There are no objects of type 'void', but values of this type can be
408   // returned from functions.
409   if (Ty->isVoidType()) {
410     Out << "void()";
411     return;
412   }
413 
414   switch (getKind()) {
415   case APValue::None:
416     Out << "<out of lifetime>";
417     return;
418   case APValue::Indeterminate:
419     Out << "<uninitialized>";
420     return;
421   case APValue::Int:
422     if (Ty->isBooleanType())
423       Out << (getInt().getBoolValue() ? "true" : "false");
424     else
425       Out << getInt();
426     return;
427   case APValue::Float:
428     Out << GetApproxValue(getFloat());
429     return;
430   case APValue::FixedPoint:
431     Out << getFixedPoint();
432     return;
433   case APValue::Vector: {
434     Out << '{';
435     QualType ElemTy = Ty->castAs<VectorType>()->getElementType();
436     getVectorElt(0).printPretty(Out, Ctx, ElemTy);
437     for (unsigned i = 1; i != getVectorLength(); ++i) {
438       Out << ", ";
439       getVectorElt(i).printPretty(Out, Ctx, ElemTy);
440     }
441     Out << '}';
442     return;
443   }
444   case APValue::ComplexInt:
445     Out << getComplexIntReal() << "+" << getComplexIntImag() << "i";
446     return;
447   case APValue::ComplexFloat:
448     Out << GetApproxValue(getComplexFloatReal()) << "+"
449         << GetApproxValue(getComplexFloatImag()) << "i";
450     return;
451   case APValue::LValue: {
452     bool IsReference = Ty->isReferenceType();
453     QualType InnerTy
454       = IsReference ? Ty.getNonReferenceType() : Ty->getPointeeType();
455     if (InnerTy.isNull())
456       InnerTy = Ty;
457 
458     LValueBase Base = getLValueBase();
459     if (!Base) {
460       if (isNullPointer()) {
461         Out << (Ctx.getLangOpts().CPlusPlus11 ? "nullptr" : "0");
462       } else if (IsReference) {
463         Out << "*(" << InnerTy.stream(Ctx.getPrintingPolicy()) << "*)"
464             << getLValueOffset().getQuantity();
465       } else {
466         Out << "(" << Ty.stream(Ctx.getPrintingPolicy()) << ")"
467             << getLValueOffset().getQuantity();
468       }
469       return;
470     }
471 
472     if (!hasLValuePath()) {
473       // No lvalue path: just print the offset.
474       CharUnits O = getLValueOffset();
475       CharUnits S = Ctx.getTypeSizeInChars(InnerTy);
476       if (!O.isZero()) {
477         if (IsReference)
478           Out << "*(";
479         if (O % S) {
480           Out << "(char*)";
481           S = CharUnits::One();
482         }
483         Out << '&';
484       } else if (!IsReference) {
485         Out << '&';
486       }
487 
488       if (const ValueDecl *VD = Base.dyn_cast<const ValueDecl*>())
489         Out << *VD;
490       else if (TypeInfoLValue TI = Base.dyn_cast<TypeInfoLValue>()) {
491         TI.print(Out, Ctx.getPrintingPolicy());
492       } else if (DynamicAllocLValue DA = Base.dyn_cast<DynamicAllocLValue>()) {
493         Out << "{*new "
494             << Base.getDynamicAllocType().stream(Ctx.getPrintingPolicy()) << "#"
495             << DA.getIndex() << "}";
496       } else {
497         assert(Base.get<const Expr *>() != nullptr &&
498                "Expecting non-null Expr");
499         Base.get<const Expr*>()->printPretty(Out, nullptr,
500                                              Ctx.getPrintingPolicy());
501       }
502 
503       if (!O.isZero()) {
504         Out << " + " << (O / S);
505         if (IsReference)
506           Out << ')';
507       }
508       return;
509     }
510 
511     // We have an lvalue path. Print it out nicely.
512     if (!IsReference)
513       Out << '&';
514     else if (isLValueOnePastTheEnd())
515       Out << "*(&";
516 
517     QualType ElemTy;
518     if (const ValueDecl *VD = Base.dyn_cast<const ValueDecl*>()) {
519       Out << *VD;
520       ElemTy = VD->getType();
521     } else if (TypeInfoLValue TI = Base.dyn_cast<TypeInfoLValue>()) {
522       TI.print(Out, Ctx.getPrintingPolicy());
523       ElemTy = Base.getTypeInfoType();
524     } else if (DynamicAllocLValue DA = Base.dyn_cast<DynamicAllocLValue>()) {
525       Out << "{*new "
526           << Base.getDynamicAllocType().stream(Ctx.getPrintingPolicy()) << "#"
527           << DA.getIndex() << "}";
528       ElemTy = Base.getDynamicAllocType();
529     } else {
530       const Expr *E = Base.get<const Expr*>();
531       assert(E != nullptr && "Expecting non-null Expr");
532       E->printPretty(Out, nullptr, Ctx.getPrintingPolicy());
533       // FIXME: This is wrong if E is a MaterializeTemporaryExpr with an lvalue
534       // adjustment.
535       ElemTy = E->getType();
536     }
537 
538     ArrayRef<LValuePathEntry> Path = getLValuePath();
539     const CXXRecordDecl *CastToBase = nullptr;
540     for (unsigned I = 0, N = Path.size(); I != N; ++I) {
541       if (ElemTy->getAs<RecordType>()) {
542         // The lvalue refers to a class type, so the next path entry is a base
543         // or member.
544         const Decl *BaseOrMember = Path[I].getAsBaseOrMember().getPointer();
545         if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(BaseOrMember)) {
546           CastToBase = RD;
547           ElemTy = Ctx.getRecordType(RD);
548         } else {
549           const ValueDecl *VD = cast<ValueDecl>(BaseOrMember);
550           Out << ".";
551           if (CastToBase)
552             Out << *CastToBase << "::";
553           Out << *VD;
554           ElemTy = VD->getType();
555         }
556       } else {
557         // The lvalue must refer to an array.
558         Out << '[' << Path[I].getAsArrayIndex() << ']';
559         ElemTy = Ctx.getAsArrayType(ElemTy)->getElementType();
560       }
561     }
562 
563     // Handle formatting of one-past-the-end lvalues.
564     if (isLValueOnePastTheEnd()) {
565       // FIXME: If CastToBase is non-0, we should prefix the output with
566       // "(CastToBase*)".
567       Out << " + 1";
568       if (IsReference)
569         Out << ')';
570     }
571     return;
572   }
573   case APValue::Array: {
574     const ArrayType *AT = Ctx.getAsArrayType(Ty);
575     QualType ElemTy = AT->getElementType();
576     Out << '{';
577     if (unsigned N = getArrayInitializedElts()) {
578       getArrayInitializedElt(0).printPretty(Out, Ctx, ElemTy);
579       for (unsigned I = 1; I != N; ++I) {
580         Out << ", ";
581         if (I == 10) {
582           // Avoid printing out the entire contents of large arrays.
583           Out << "...";
584           break;
585         }
586         getArrayInitializedElt(I).printPretty(Out, Ctx, ElemTy);
587       }
588     }
589     Out << '}';
590     return;
591   }
592   case APValue::Struct: {
593     Out << '{';
594     const RecordDecl *RD = Ty->castAs<RecordType>()->getDecl();
595     bool First = true;
596     if (unsigned N = getStructNumBases()) {
597       const CXXRecordDecl *CD = cast<CXXRecordDecl>(RD);
598       CXXRecordDecl::base_class_const_iterator BI = CD->bases_begin();
599       for (unsigned I = 0; I != N; ++I, ++BI) {
600         assert(BI != CD->bases_end());
601         if (!First)
602           Out << ", ";
603         getStructBase(I).printPretty(Out, Ctx, BI->getType());
604         First = false;
605       }
606     }
607     for (const auto *FI : RD->fields()) {
608       if (!First)
609         Out << ", ";
610       if (FI->isUnnamedBitfield()) continue;
611       getStructField(FI->getFieldIndex()).
612         printPretty(Out, Ctx, FI->getType());
613       First = false;
614     }
615     Out << '}';
616     return;
617   }
618   case APValue::Union:
619     Out << '{';
620     if (const FieldDecl *FD = getUnionField()) {
621       Out << "." << *FD << " = ";
622       getUnionValue().printPretty(Out, Ctx, FD->getType());
623     }
624     Out << '}';
625     return;
626   case APValue::MemberPointer:
627     // FIXME: This is not enough to unambiguously identify the member in a
628     // multiple-inheritance scenario.
629     if (const ValueDecl *VD = getMemberPointerDecl()) {
630       Out << '&' << *cast<CXXRecordDecl>(VD->getDeclContext()) << "::" << *VD;
631       return;
632     }
633     Out << "0";
634     return;
635   case APValue::AddrLabelDiff:
636     Out << "&&" << getAddrLabelDiffLHS()->getLabel()->getName();
637     Out << " - ";
638     Out << "&&" << getAddrLabelDiffRHS()->getLabel()->getName();
639     return;
640   }
641   llvm_unreachable("Unknown APValue kind!");
642 }
643 
644 std::string APValue::getAsString(const ASTContext &Ctx, QualType Ty) const {
645   std::string Result;
646   llvm::raw_string_ostream Out(Result);
647   printPretty(Out, Ctx, Ty);
648   Out.flush();
649   return Result;
650 }
651 
652 bool APValue::toIntegralConstant(APSInt &Result, QualType SrcTy,
653                                  const ASTContext &Ctx) const {
654   if (isInt()) {
655     Result = getInt();
656     return true;
657   }
658 
659   if (isLValue() && isNullPointer()) {
660     Result = Ctx.MakeIntValue(Ctx.getTargetNullPointerValue(SrcTy), SrcTy);
661     return true;
662   }
663 
664   if (isLValue() && !getLValueBase()) {
665     Result = Ctx.MakeIntValue(getLValueOffset().getQuantity(), SrcTy);
666     return true;
667   }
668 
669   return false;
670 }
671 
672 const APValue::LValueBase APValue::getLValueBase() const {
673   assert(isLValue() && "Invalid accessor");
674   return ((const LV*)(const void*)Data.buffer)->Base;
675 }
676 
677 bool APValue::isLValueOnePastTheEnd() const {
678   assert(isLValue() && "Invalid accessor");
679   return ((const LV*)(const void*)Data.buffer)->IsOnePastTheEnd;
680 }
681 
682 CharUnits &APValue::getLValueOffset() {
683   assert(isLValue() && "Invalid accessor");
684   return ((LV*)(void*)Data.buffer)->Offset;
685 }
686 
687 bool APValue::hasLValuePath() const {
688   assert(isLValue() && "Invalid accessor");
689   return ((const LV*)(const char*)Data.buffer)->hasPath();
690 }
691 
692 ArrayRef<APValue::LValuePathEntry> APValue::getLValuePath() const {
693   assert(isLValue() && hasLValuePath() && "Invalid accessor");
694   const LV &LVal = *((const LV*)(const char*)Data.buffer);
695   return llvm::makeArrayRef(LVal.getPath(), LVal.PathLength);
696 }
697 
698 unsigned APValue::getLValueCallIndex() const {
699   assert(isLValue() && "Invalid accessor");
700   return ((const LV*)(const char*)Data.buffer)->Base.getCallIndex();
701 }
702 
703 unsigned APValue::getLValueVersion() const {
704   assert(isLValue() && "Invalid accessor");
705   return ((const LV*)(const char*)Data.buffer)->Base.getVersion();
706 }
707 
708 bool APValue::isNullPointer() const {
709   assert(isLValue() && "Invalid usage");
710   return ((const LV*)(const char*)Data.buffer)->IsNullPtr;
711 }
712 
713 void APValue::setLValue(LValueBase B, const CharUnits &O, NoLValuePath,
714                         bool IsNullPtr) {
715   assert(isLValue() && "Invalid accessor");
716   LV &LVal = *((LV*)(char*)Data.buffer);
717   LVal.Base = B;
718   LVal.IsOnePastTheEnd = false;
719   LVal.Offset = O;
720   LVal.resizePath((unsigned)-1);
721   LVal.IsNullPtr = IsNullPtr;
722 }
723 
724 void APValue::setLValue(LValueBase B, const CharUnits &O,
725                         ArrayRef<LValuePathEntry> Path, bool IsOnePastTheEnd,
726                         bool IsNullPtr) {
727   assert(isLValue() && "Invalid accessor");
728   LV &LVal = *((LV*)(char*)Data.buffer);
729   LVal.Base = B;
730   LVal.IsOnePastTheEnd = IsOnePastTheEnd;
731   LVal.Offset = O;
732   LVal.resizePath(Path.size());
733   memcpy(LVal.getPath(), Path.data(), Path.size() * sizeof(LValuePathEntry));
734   LVal.IsNullPtr = IsNullPtr;
735 }
736 
737 const ValueDecl *APValue::getMemberPointerDecl() const {
738   assert(isMemberPointer() && "Invalid accessor");
739   const MemberPointerData &MPD =
740       *((const MemberPointerData *)(const char *)Data.buffer);
741   return MPD.MemberAndIsDerivedMember.getPointer();
742 }
743 
744 bool APValue::isMemberPointerToDerivedMember() const {
745   assert(isMemberPointer() && "Invalid accessor");
746   const MemberPointerData &MPD =
747       *((const MemberPointerData *)(const char *)Data.buffer);
748   return MPD.MemberAndIsDerivedMember.getInt();
749 }
750 
751 ArrayRef<const CXXRecordDecl*> APValue::getMemberPointerPath() const {
752   assert(isMemberPointer() && "Invalid accessor");
753   const MemberPointerData &MPD =
754       *((const MemberPointerData *)(const char *)Data.buffer);
755   return llvm::makeArrayRef(MPD.getPath(), MPD.PathLength);
756 }
757 
758 void APValue::MakeLValue() {
759   assert(isAbsent() && "Bad state change");
760   static_assert(sizeof(LV) <= DataSize, "LV too big");
761   new ((void*)(char*)Data.buffer) LV();
762   Kind = LValue;
763 }
764 
765 void APValue::MakeArray(unsigned InitElts, unsigned Size) {
766   assert(isAbsent() && "Bad state change");
767   new ((void*)(char*)Data.buffer) Arr(InitElts, Size);
768   Kind = Array;
769 }
770 
771 void APValue::MakeMemberPointer(const ValueDecl *Member, bool IsDerivedMember,
772                                 ArrayRef<const CXXRecordDecl*> Path) {
773   assert(isAbsent() && "Bad state change");
774   MemberPointerData *MPD = new ((void*)(char*)Data.buffer) MemberPointerData;
775   Kind = MemberPointer;
776   MPD->MemberAndIsDerivedMember.setPointer(Member);
777   MPD->MemberAndIsDerivedMember.setInt(IsDerivedMember);
778   MPD->resizePath(Path.size());
779   memcpy(MPD->getPath(), Path.data(), Path.size()*sizeof(const CXXRecordDecl*));
780 }
781