xref: /freebsd/contrib/llvm-project/clang/lib/AST/APValue.cpp (revision 85868e8a1daeaae7a0e48effb2ea2310ae3b02c6) 
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 void APValue::DestroyDataAndMakeUninit() {
308   if (Kind == Int)
309     ((APSInt*)(char*)Data.buffer)->~APSInt();
310   else if (Kind == Float)
311     ((APFloat*)(char*)Data.buffer)->~APFloat();
312   else if (Kind == FixedPoint)
313     ((APFixedPoint *)(char *)Data.buffer)->~APFixedPoint();
314   else if (Kind == Vector)
315     ((Vec*)(char*)Data.buffer)->~Vec();
316   else if (Kind == ComplexInt)
317     ((ComplexAPSInt*)(char*)Data.buffer)->~ComplexAPSInt();
318   else if (Kind == ComplexFloat)
319     ((ComplexAPFloat*)(char*)Data.buffer)->~ComplexAPFloat();
320   else if (Kind == LValue)
321     ((LV*)(char*)Data.buffer)->~LV();
322   else if (Kind == Array)
323     ((Arr*)(char*)Data.buffer)->~Arr();
324   else if (Kind == Struct)
325     ((StructData*)(char*)Data.buffer)->~StructData();
326   else if (Kind == Union)
327     ((UnionData*)(char*)Data.buffer)->~UnionData();
328   else if (Kind == MemberPointer)
329     ((MemberPointerData*)(char*)Data.buffer)->~MemberPointerData();
330   else if (Kind == AddrLabelDiff)
331     ((AddrLabelDiffData*)(char*)Data.buffer)->~AddrLabelDiffData();
332   Kind = None;
333 }
334 
335 bool APValue::needsCleanup() const {
336   switch (getKind()) {
337   case None:
338   case Indeterminate:
339   case AddrLabelDiff:
340     return false;
341   case Struct:
342   case Union:
343   case Array:
344   case Vector:
345     return true;
346   case Int:
347     return getInt().needsCleanup();
348   case Float:
349     return getFloat().needsCleanup();
350   case FixedPoint:
351     return getFixedPoint().getValue().needsCleanup();
352   case ComplexFloat:
353     assert(getComplexFloatImag().needsCleanup() ==
354                getComplexFloatReal().needsCleanup() &&
355            "In _Complex float types, real and imaginary values always have the "
356            "same size.");
357     return getComplexFloatReal().needsCleanup();
358   case ComplexInt:
359     assert(getComplexIntImag().needsCleanup() ==
360                getComplexIntReal().needsCleanup() &&
361            "In _Complex int types, real and imaginary values must have the "
362            "same size.");
363     return getComplexIntReal().needsCleanup();
364   case LValue:
365     return reinterpret_cast<const LV *>(Data.buffer)->hasPathPtr();
366   case MemberPointer:
367     return reinterpret_cast<const MemberPointerData *>(Data.buffer)
368         ->hasPathPtr();
369   }
370   llvm_unreachable("Unknown APValue kind!");
371 }
372 
373 void APValue::swap(APValue &RHS) {
374   std::swap(Kind, RHS.Kind);
375   char TmpData[DataSize];
376   memcpy(TmpData, Data.buffer, DataSize);
377   memcpy(Data.buffer, RHS.Data.buffer, DataSize);
378   memcpy(RHS.Data.buffer, TmpData, DataSize);
379 }
380 
381 LLVM_DUMP_METHOD void APValue::dump() const {
382   dump(llvm::errs());
383   llvm::errs() << '\n';
384 }
385 
386 static double GetApproxValue(const llvm::APFloat &F) {
387   llvm::APFloat V = F;
388   bool ignored;
389   V.convert(llvm::APFloat::IEEEdouble(), llvm::APFloat::rmNearestTiesToEven,
390             &ignored);
391   return V.convertToDouble();
392 }
393 
394 void APValue::dump(raw_ostream &OS) const {
395   switch (getKind()) {
396   case None:
397     OS << "None";
398     return;
399   case Indeterminate:
400     OS << "Indeterminate";
401     return;
402   case Int:
403     OS << "Int: " << getInt();
404     return;
405   case Float:
406     OS << "Float: " << GetApproxValue(getFloat());
407     return;
408   case FixedPoint:
409     OS << "FixedPoint : " << getFixedPoint();
410     return;
411   case Vector:
412     OS << "Vector: ";
413     getVectorElt(0).dump(OS);
414     for (unsigned i = 1; i != getVectorLength(); ++i) {
415       OS << ", ";
416       getVectorElt(i).dump(OS);
417     }
418     return;
419   case ComplexInt:
420     OS << "ComplexInt: " << getComplexIntReal() << ", " << getComplexIntImag();
421     return;
422   case ComplexFloat:
423     OS << "ComplexFloat: " << GetApproxValue(getComplexFloatReal())
424        << ", " << GetApproxValue(getComplexFloatImag());
425     return;
426   case LValue:
427     OS << "LValue: <todo>";
428     return;
429   case Array:
430     OS << "Array: ";
431     for (unsigned I = 0, N = getArrayInitializedElts(); I != N; ++I) {
432       getArrayInitializedElt(I).dump(OS);
433       if (I != getArraySize() - 1) OS << ", ";
434     }
435     if (hasArrayFiller()) {
436       OS << getArraySize() - getArrayInitializedElts() << " x ";
437       getArrayFiller().dump(OS);
438     }
439     return;
440   case Struct:
441     OS << "Struct ";
442     if (unsigned N = getStructNumBases()) {
443       OS << " bases: ";
444       getStructBase(0).dump(OS);
445       for (unsigned I = 1; I != N; ++I) {
446         OS << ", ";
447         getStructBase(I).dump(OS);
448       }
449     }
450     if (unsigned N = getStructNumFields()) {
451       OS << " fields: ";
452       getStructField(0).dump(OS);
453       for (unsigned I = 1; I != N; ++I) {
454         OS << ", ";
455         getStructField(I).dump(OS);
456       }
457     }
458     return;
459   case Union:
460     OS << "Union: ";
461     getUnionValue().dump(OS);
462     return;
463   case MemberPointer:
464     OS << "MemberPointer: <todo>";
465     return;
466   case AddrLabelDiff:
467     OS << "AddrLabelDiff: <todo>";
468     return;
469   }
470   llvm_unreachable("Unknown APValue kind!");
471 }
472 
473 void APValue::printPretty(raw_ostream &Out, const ASTContext &Ctx,
474                           QualType Ty) const {
475   switch (getKind()) {
476   case APValue::None:
477     Out << "<out of lifetime>";
478     return;
479   case APValue::Indeterminate:
480     Out << "<uninitialized>";
481     return;
482   case APValue::Int:
483     if (Ty->isBooleanType())
484       Out << (getInt().getBoolValue() ? "true" : "false");
485     else
486       Out << getInt();
487     return;
488   case APValue::Float:
489     Out << GetApproxValue(getFloat());
490     return;
491   case APValue::FixedPoint:
492     Out << getFixedPoint();
493     return;
494   case APValue::Vector: {
495     Out << '{';
496     QualType ElemTy = Ty->castAs<VectorType>()->getElementType();
497     getVectorElt(0).printPretty(Out, Ctx, ElemTy);
498     for (unsigned i = 1; i != getVectorLength(); ++i) {
499       Out << ", ";
500       getVectorElt(i).printPretty(Out, Ctx, ElemTy);
501     }
502     Out << '}';
503     return;
504   }
505   case APValue::ComplexInt:
506     Out << getComplexIntReal() << "+" << getComplexIntImag() << "i";
507     return;
508   case APValue::ComplexFloat:
509     Out << GetApproxValue(getComplexFloatReal()) << "+"
510         << GetApproxValue(getComplexFloatImag()) << "i";
511     return;
512   case APValue::LValue: {
513     bool IsReference = Ty->isReferenceType();
514     QualType InnerTy
515       = IsReference ? Ty.getNonReferenceType() : Ty->getPointeeType();
516     if (InnerTy.isNull())
517       InnerTy = Ty;
518 
519     LValueBase Base = getLValueBase();
520     if (!Base) {
521       if (isNullPointer()) {
522         Out << (Ctx.getLangOpts().CPlusPlus11 ? "nullptr" : "0");
523       } else if (IsReference) {
524         Out << "*(" << InnerTy.stream(Ctx.getPrintingPolicy()) << "*)"
525             << getLValueOffset().getQuantity();
526       } else {
527         Out << "(" << Ty.stream(Ctx.getPrintingPolicy()) << ")"
528             << getLValueOffset().getQuantity();
529       }
530       return;
531     }
532 
533     if (!hasLValuePath()) {
534       // No lvalue path: just print the offset.
535       CharUnits O = getLValueOffset();
536       CharUnits S = Ctx.getTypeSizeInChars(InnerTy);
537       if (!O.isZero()) {
538         if (IsReference)
539           Out << "*(";
540         if (O % S) {
541           Out << "(char*)";
542           S = CharUnits::One();
543         }
544         Out << '&';
545       } else if (!IsReference) {
546         Out << '&';
547       }
548 
549       if (const ValueDecl *VD = Base.dyn_cast<const ValueDecl*>())
550         Out << *VD;
551       else if (TypeInfoLValue TI = Base.dyn_cast<TypeInfoLValue>()) {
552         TI.print(Out, Ctx.getPrintingPolicy());
553       } else if (DynamicAllocLValue DA = Base.dyn_cast<DynamicAllocLValue>()) {
554         Out << "{*new "
555             << Base.getDynamicAllocType().stream(Ctx.getPrintingPolicy()) << "#"
556             << DA.getIndex() << "}";
557       } else {
558         assert(Base.get<const Expr *>() != nullptr &&
559                "Expecting non-null Expr");
560         Base.get<const Expr*>()->printPretty(Out, nullptr,
561                                              Ctx.getPrintingPolicy());
562       }
563 
564       if (!O.isZero()) {
565         Out << " + " << (O / S);
566         if (IsReference)
567           Out << ')';
568       }
569       return;
570     }
571 
572     // We have an lvalue path. Print it out nicely.
573     if (!IsReference)
574       Out << '&';
575     else if (isLValueOnePastTheEnd())
576       Out << "*(&";
577 
578     QualType ElemTy;
579     if (const ValueDecl *VD = Base.dyn_cast<const ValueDecl*>()) {
580       Out << *VD;
581       ElemTy = VD->getType();
582     } else if (TypeInfoLValue TI = Base.dyn_cast<TypeInfoLValue>()) {
583       TI.print(Out, Ctx.getPrintingPolicy());
584       ElemTy = Base.getTypeInfoType();
585     } else if (DynamicAllocLValue DA = Base.dyn_cast<DynamicAllocLValue>()) {
586       Out << "{*new "
587           << Base.getDynamicAllocType().stream(Ctx.getPrintingPolicy()) << "#"
588           << DA.getIndex() << "}";
589       ElemTy = Base.getDynamicAllocType();
590     } else {
591       const Expr *E = Base.get<const Expr*>();
592       assert(E != nullptr && "Expecting non-null Expr");
593       E->printPretty(Out, nullptr, Ctx.getPrintingPolicy());
594       // FIXME: This is wrong if E is a MaterializeTemporaryExpr with an lvalue
595       // adjustment.
596       ElemTy = E->getType();
597     }
598 
599     ArrayRef<LValuePathEntry> Path = getLValuePath();
600     const CXXRecordDecl *CastToBase = nullptr;
601     for (unsigned I = 0, N = Path.size(); I != N; ++I) {
602       if (ElemTy->getAs<RecordType>()) {
603         // The lvalue refers to a class type, so the next path entry is a base
604         // or member.
605         const Decl *BaseOrMember = Path[I].getAsBaseOrMember().getPointer();
606         if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(BaseOrMember)) {
607           CastToBase = RD;
608           ElemTy = Ctx.getRecordType(RD);
609         } else {
610           const ValueDecl *VD = cast<ValueDecl>(BaseOrMember);
611           Out << ".";
612           if (CastToBase)
613             Out << *CastToBase << "::";
614           Out << *VD;
615           ElemTy = VD->getType();
616         }
617       } else {
618         // The lvalue must refer to an array.
619         Out << '[' << Path[I].getAsArrayIndex() << ']';
620         ElemTy = Ctx.getAsArrayType(ElemTy)->getElementType();
621       }
622     }
623 
624     // Handle formatting of one-past-the-end lvalues.
625     if (isLValueOnePastTheEnd()) {
626       // FIXME: If CastToBase is non-0, we should prefix the output with
627       // "(CastToBase*)".
628       Out << " + 1";
629       if (IsReference)
630         Out << ')';
631     }
632     return;
633   }
634   case APValue::Array: {
635     const ArrayType *AT = Ctx.getAsArrayType(Ty);
636     QualType ElemTy = AT->getElementType();
637     Out << '{';
638     if (unsigned N = getArrayInitializedElts()) {
639       getArrayInitializedElt(0).printPretty(Out, Ctx, ElemTy);
640       for (unsigned I = 1; I != N; ++I) {
641         Out << ", ";
642         if (I == 10) {
643           // Avoid printing out the entire contents of large arrays.
644           Out << "...";
645           break;
646         }
647         getArrayInitializedElt(I).printPretty(Out, Ctx, ElemTy);
648       }
649     }
650     Out << '}';
651     return;
652   }
653   case APValue::Struct: {
654     Out << '{';
655     const RecordDecl *RD = Ty->castAs<RecordType>()->getDecl();
656     bool First = true;
657     if (unsigned N = getStructNumBases()) {
658       const CXXRecordDecl *CD = cast<CXXRecordDecl>(RD);
659       CXXRecordDecl::base_class_const_iterator BI = CD->bases_begin();
660       for (unsigned I = 0; I != N; ++I, ++BI) {
661         assert(BI != CD->bases_end());
662         if (!First)
663           Out << ", ";
664         getStructBase(I).printPretty(Out, Ctx, BI->getType());
665         First = false;
666       }
667     }
668     for (const auto *FI : RD->fields()) {
669       if (!First)
670         Out << ", ";
671       if (FI->isUnnamedBitfield()) continue;
672       getStructField(FI->getFieldIndex()).
673         printPretty(Out, Ctx, FI->getType());
674       First = false;
675     }
676     Out << '}';
677     return;
678   }
679   case APValue::Union:
680     Out << '{';
681     if (const FieldDecl *FD = getUnionField()) {
682       Out << "." << *FD << " = ";
683       getUnionValue().printPretty(Out, Ctx, FD->getType());
684     }
685     Out << '}';
686     return;
687   case APValue::MemberPointer:
688     // FIXME: This is not enough to unambiguously identify the member in a
689     // multiple-inheritance scenario.
690     if (const ValueDecl *VD = getMemberPointerDecl()) {
691       Out << '&' << *cast<CXXRecordDecl>(VD->getDeclContext()) << "::" << *VD;
692       return;
693     }
694     Out << "0";
695     return;
696   case APValue::AddrLabelDiff:
697     Out << "&&" << getAddrLabelDiffLHS()->getLabel()->getName();
698     Out << " - ";
699     Out << "&&" << getAddrLabelDiffRHS()->getLabel()->getName();
700     return;
701   }
702   llvm_unreachable("Unknown APValue kind!");
703 }
704 
705 std::string APValue::getAsString(const ASTContext &Ctx, QualType Ty) const {
706   std::string Result;
707   llvm::raw_string_ostream Out(Result);
708   printPretty(Out, Ctx, Ty);
709   Out.flush();
710   return Result;
711 }
712 
713 bool APValue::toIntegralConstant(APSInt &Result, QualType SrcTy,
714                                  const ASTContext &Ctx) const {
715   if (isInt()) {
716     Result = getInt();
717     return true;
718   }
719 
720   if (isLValue() && isNullPointer()) {
721     Result = Ctx.MakeIntValue(Ctx.getTargetNullPointerValue(SrcTy), SrcTy);
722     return true;
723   }
724 
725   if (isLValue() && !getLValueBase()) {
726     Result = Ctx.MakeIntValue(getLValueOffset().getQuantity(), SrcTy);
727     return true;
728   }
729 
730   return false;
731 }
732 
733 const APValue::LValueBase APValue::getLValueBase() const {
734   assert(isLValue() && "Invalid accessor");
735   return ((const LV*)(const void*)Data.buffer)->Base;
736 }
737 
738 bool APValue::isLValueOnePastTheEnd() const {
739   assert(isLValue() && "Invalid accessor");
740   return ((const LV*)(const void*)Data.buffer)->IsOnePastTheEnd;
741 }
742 
743 CharUnits &APValue::getLValueOffset() {
744   assert(isLValue() && "Invalid accessor");
745   return ((LV*)(void*)Data.buffer)->Offset;
746 }
747 
748 bool APValue::hasLValuePath() const {
749   assert(isLValue() && "Invalid accessor");
750   return ((const LV*)(const char*)Data.buffer)->hasPath();
751 }
752 
753 ArrayRef<APValue::LValuePathEntry> APValue::getLValuePath() const {
754   assert(isLValue() && hasLValuePath() && "Invalid accessor");
755   const LV &LVal = *((const LV*)(const char*)Data.buffer);
756   return llvm::makeArrayRef(LVal.getPath(), LVal.PathLength);
757 }
758 
759 unsigned APValue::getLValueCallIndex() const {
760   assert(isLValue() && "Invalid accessor");
761   return ((const LV*)(const char*)Data.buffer)->Base.getCallIndex();
762 }
763 
764 unsigned APValue::getLValueVersion() const {
765   assert(isLValue() && "Invalid accessor");
766   return ((const LV*)(const char*)Data.buffer)->Base.getVersion();
767 }
768 
769 bool APValue::isNullPointer() const {
770   assert(isLValue() && "Invalid usage");
771   return ((const LV*)(const char*)Data.buffer)->IsNullPtr;
772 }
773 
774 void APValue::setLValue(LValueBase B, const CharUnits &O, NoLValuePath,
775                         bool IsNullPtr) {
776   assert(isLValue() && "Invalid accessor");
777   LV &LVal = *((LV*)(char*)Data.buffer);
778   LVal.Base = B;
779   LVal.IsOnePastTheEnd = false;
780   LVal.Offset = O;
781   LVal.resizePath((unsigned)-1);
782   LVal.IsNullPtr = IsNullPtr;
783 }
784 
785 void APValue::setLValue(LValueBase B, const CharUnits &O,
786                         ArrayRef<LValuePathEntry> Path, bool IsOnePastTheEnd,
787                         bool IsNullPtr) {
788   assert(isLValue() && "Invalid accessor");
789   LV &LVal = *((LV*)(char*)Data.buffer);
790   LVal.Base = B;
791   LVal.IsOnePastTheEnd = IsOnePastTheEnd;
792   LVal.Offset = O;
793   LVal.resizePath(Path.size());
794   memcpy(LVal.getPath(), Path.data(), Path.size() * sizeof(LValuePathEntry));
795   LVal.IsNullPtr = IsNullPtr;
796 }
797 
798 const ValueDecl *APValue::getMemberPointerDecl() const {
799   assert(isMemberPointer() && "Invalid accessor");
800   const MemberPointerData &MPD =
801       *((const MemberPointerData *)(const char *)Data.buffer);
802   return MPD.MemberAndIsDerivedMember.getPointer();
803 }
804 
805 bool APValue::isMemberPointerToDerivedMember() const {
806   assert(isMemberPointer() && "Invalid accessor");
807   const MemberPointerData &MPD =
808       *((const MemberPointerData *)(const char *)Data.buffer);
809   return MPD.MemberAndIsDerivedMember.getInt();
810 }
811 
812 ArrayRef<const CXXRecordDecl*> APValue::getMemberPointerPath() const {
813   assert(isMemberPointer() && "Invalid accessor");
814   const MemberPointerData &MPD =
815       *((const MemberPointerData *)(const char *)Data.buffer);
816   return llvm::makeArrayRef(MPD.getPath(), MPD.PathLength);
817 }
818 
819 void APValue::MakeLValue() {
820   assert(isAbsent() && "Bad state change");
821   static_assert(sizeof(LV) <= DataSize, "LV too big");
822   new ((void*)(char*)Data.buffer) LV();
823   Kind = LValue;
824 }
825 
826 void APValue::MakeArray(unsigned InitElts, unsigned Size) {
827   assert(isAbsent() && "Bad state change");
828   new ((void*)(char*)Data.buffer) Arr(InitElts, Size);
829   Kind = Array;
830 }
831 
832 void APValue::MakeMemberPointer(const ValueDecl *Member, bool IsDerivedMember,
833                                 ArrayRef<const CXXRecordDecl*> Path) {
834   assert(isAbsent() && "Bad state change");
835   MemberPointerData *MPD = new ((void*)(char*)Data.buffer) MemberPointerData;
836   Kind = MemberPointer;
837   MPD->MemberAndIsDerivedMember.setPointer(Member);
838   MPD->MemberAndIsDerivedMember.setInt(IsDerivedMember);
839   MPD->resizePath(Path.size());
840   memcpy(MPD->getPath(), Path.data(), Path.size()*sizeof(const CXXRecordDecl*));
841 }
842