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"
24using namespace clang;
25
26namespace {
27  struct LVBase {
28    llvm::PointerIntPair<APValue::LValueBase, 1, bool> BaseAndIsOnePastTheEnd;
29    CharUnits Offset;
30    unsigned PathLength;
31    unsigned CallIndex;
32  };
33}
34
35struct APValue::LV : LVBase {
36  static const unsigned InlinePathSpace =
37      (MaxSize - 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
69namespace {
70  struct MemberPointerBase {
71    llvm::PointerIntPair<const ValueDecl*, 1, bool> MemberAndIsDerivedMember;
72    unsigned PathLength;
73  };
74}
75
76struct APValue::MemberPointerData : MemberPointerBase {
77  static const unsigned InlinePathSpace =
78      (MaxSize - 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
108APValue::Arr::Arr(unsigned NumElts, unsigned Size) :
109  Elts(new APValue[NumElts + (NumElts != Size ? 1 : 0)]),
110  NumElts(NumElts), ArrSize(Size) {}
111APValue::Arr::~Arr() { delete [] Elts; }
112
113APValue::StructData::StructData(unsigned NumBases, unsigned NumFields) :
114  Elts(new APValue[NumBases+NumFields]),
115  NumBases(NumBases), NumFields(NumFields) {}
116APValue::StructData::~StructData() {
117  delete [] Elts;
118}
119
120APValue::UnionData::UnionData() : Field(0), Value(new APValue) {}
121APValue::UnionData::~UnionData () {
122  delete Value;
123}
124
125APValue::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)->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
189void APValue::DestroyDataAndMakeUninit() {
190  if (Kind == Int)
191    ((APSInt*)(char*)Data)->~APSInt();
192  else if (Kind == Float)
193    ((APFloat*)(char*)Data)->~APFloat();
194  else if (Kind == Vector)
195    ((Vec*)(char*)Data)->~Vec();
196  else if (Kind == ComplexInt)
197    ((ComplexAPSInt*)(char*)Data)->~ComplexAPSInt();
198  else if (Kind == ComplexFloat)
199    ((ComplexAPFloat*)(char*)Data)->~ComplexAPFloat();
200  else if (Kind == LValue)
201    ((LV*)(char*)Data)->~LV();
202  else if (Kind == Array)
203    ((Arr*)(char*)Data)->~Arr();
204  else if (Kind == Struct)
205    ((StructData*)(char*)Data)->~StructData();
206  else if (Kind == Union)
207    ((UnionData*)(char*)Data)->~UnionData();
208  else if (Kind == MemberPointer)
209    ((MemberPointerData*)(char*)Data)->~MemberPointerData();
210  else if (Kind == AddrLabelDiff)
211    ((AddrLabelDiffData*)(char*)Data)->~AddrLabelDiffData();
212  Kind = Uninitialized;
213}
214
215void APValue::swap(APValue &RHS) {
216  std::swap(Kind, RHS.Kind);
217  char TmpData[MaxSize];
218  memcpy(TmpData, Data, MaxSize);
219  memcpy(Data, RHS.Data, MaxSize);
220  memcpy(RHS.Data, TmpData, MaxSize);
221}
222
223void APValue::dump() const {
224  dump(llvm::errs());
225  llvm::errs() << '\n';
226}
227
228static double GetApproxValue(const llvm::APFloat &F) {
229  llvm::APFloat V = F;
230  bool ignored;
231  V.convert(llvm::APFloat::IEEEdouble, llvm::APFloat::rmNearestTiesToEven,
232            &ignored);
233  return V.convertToDouble();
234}
235
236void APValue::dump(raw_ostream &OS) const {
237  switch (getKind()) {
238  case Uninitialized:
239    OS << "Uninitialized";
240    return;
241  case Int:
242    OS << "Int: " << getInt();
243    return;
244  case Float:
245    OS << "Float: " << GetApproxValue(getFloat());
246    return;
247  case Vector:
248    OS << "Vector: ";
249    getVectorElt(0).dump(OS);
250    for (unsigned i = 1; i != getVectorLength(); ++i) {
251      OS << ", ";
252      getVectorElt(i).dump(OS);
253    }
254    return;
255  case ComplexInt:
256    OS << "ComplexInt: " << getComplexIntReal() << ", " << getComplexIntImag();
257    return;
258  case ComplexFloat:
259    OS << "ComplexFloat: " << GetApproxValue(getComplexFloatReal())
260       << ", " << GetApproxValue(getComplexFloatImag());
261    return;
262  case LValue:
263    OS << "LValue: <todo>";
264    return;
265  case Array:
266    OS << "Array: ";
267    for (unsigned I = 0, N = getArrayInitializedElts(); I != N; ++I) {
268      getArrayInitializedElt(I).dump(OS);
269      if (I != getArraySize() - 1) OS << ", ";
270    }
271    if (hasArrayFiller()) {
272      OS << getArraySize() - getArrayInitializedElts() << " x ";
273      getArrayFiller().dump(OS);
274    }
275    return;
276  case Struct:
277    OS << "Struct ";
278    if (unsigned N = getStructNumBases()) {
279      OS << " bases: ";
280      getStructBase(0).dump(OS);
281      for (unsigned I = 1; I != N; ++I) {
282        OS << ", ";
283        getStructBase(I).dump(OS);
284      }
285    }
286    if (unsigned N = getStructNumFields()) {
287      OS << " fields: ";
288      getStructField(0).dump(OS);
289      for (unsigned I = 1; I != N; ++I) {
290        OS << ", ";
291        getStructField(I).dump(OS);
292      }
293    }
294    return;
295  case Union:
296    OS << "Union: ";
297    getUnionValue().dump(OS);
298    return;
299  case MemberPointer:
300    OS << "MemberPointer: <todo>";
301    return;
302  case AddrLabelDiff:
303    OS << "AddrLabelDiff: <todo>";
304    return;
305  }
306  llvm_unreachable("Unknown APValue kind!");
307}
308
309void APValue::printPretty(raw_ostream &Out, ASTContext &Ctx, QualType Ty) const{
310  switch (getKind()) {
311  case APValue::Uninitialized:
312    Out << "<uninitialized>";
313    return;
314  case APValue::Int:
315    if (Ty->isBooleanType())
316      Out << (getInt().getBoolValue() ? "true" : "false");
317    else
318      Out << getInt();
319    return;
320  case APValue::Float:
321    Out << GetApproxValue(getFloat());
322    return;
323  case APValue::Vector: {
324    Out << '{';
325    QualType ElemTy = Ty->getAs<VectorType>()->getElementType();
326    getVectorElt(0).printPretty(Out, Ctx, ElemTy);
327    for (unsigned i = 1; i != getVectorLength(); ++i) {
328      Out << ", ";
329      getVectorElt(i).printPretty(Out, Ctx, ElemTy);
330    }
331    Out << '}';
332    return;
333  }
334  case APValue::ComplexInt:
335    Out << getComplexIntReal() << "+" << getComplexIntImag() << "i";
336    return;
337  case APValue::ComplexFloat:
338    Out << GetApproxValue(getComplexFloatReal()) << "+"
339        << GetApproxValue(getComplexFloatImag()) << "i";
340    return;
341  case APValue::LValue: {
342    LValueBase Base = getLValueBase();
343    if (!Base) {
344      Out << "0";
345      return;
346    }
347
348    bool IsReference = Ty->isReferenceType();
349    QualType InnerTy
350      = IsReference ? Ty.getNonReferenceType() : Ty->getPointeeType();
351    if (InnerTy.isNull())
352      InnerTy = Ty;
353
354    if (!hasLValuePath()) {
355      // No lvalue path: just print the offset.
356      CharUnits O = getLValueOffset();
357      CharUnits S = Ctx.getTypeSizeInChars(InnerTy);
358      if (!O.isZero()) {
359        if (IsReference)
360          Out << "*(";
361        if (O % S) {
362          Out << "(char*)";
363          S = CharUnits::One();
364        }
365        Out << '&';
366      } else if (!IsReference)
367        Out << '&';
368
369      if (const ValueDecl *VD = Base.dyn_cast<const ValueDecl*>())
370        Out << *VD;
371      else
372        Base.get<const Expr*>()->printPretty(Out, 0, Ctx.getPrintingPolicy());
373      if (!O.isZero()) {
374        Out << " + " << (O / S);
375        if (IsReference)
376          Out << ')';
377      }
378      return;
379    }
380
381    // We have an lvalue path. Print it out nicely.
382    if (!IsReference)
383      Out << '&';
384    else if (isLValueOnePastTheEnd())
385      Out << "*(&";
386
387    QualType ElemTy;
388    if (const ValueDecl *VD = Base.dyn_cast<const ValueDecl*>()) {
389      Out << *VD;
390      ElemTy = VD->getType();
391    } else {
392      const Expr *E = Base.get<const Expr*>();
393      E->printPretty(Out, 0, Ctx.getPrintingPolicy());
394      ElemTy = E->getType();
395    }
396
397    ArrayRef<LValuePathEntry> Path = getLValuePath();
398    const CXXRecordDecl *CastToBase = 0;
399    for (unsigned I = 0, N = Path.size(); I != N; ++I) {
400      if (ElemTy->getAs<RecordType>()) {
401        // The lvalue refers to a class type, so the next path entry is a base
402        // or member.
403        const Decl *BaseOrMember =
404        BaseOrMemberType::getFromOpaqueValue(Path[I].BaseOrMember).getPointer();
405        if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(BaseOrMember)) {
406          CastToBase = RD;
407          ElemTy = Ctx.getRecordType(RD);
408        } else {
409          const ValueDecl *VD = cast<ValueDecl>(BaseOrMember);
410          Out << ".";
411          if (CastToBase)
412            Out << *CastToBase << "::";
413          Out << *VD;
414          ElemTy = VD->getType();
415        }
416      } else {
417        // The lvalue must refer to an array.
418        Out << '[' << Path[I].ArrayIndex << ']';
419        ElemTy = Ctx.getAsArrayType(ElemTy)->getElementType();
420      }
421    }
422
423    // Handle formatting of one-past-the-end lvalues.
424    if (isLValueOnePastTheEnd()) {
425      // FIXME: If CastToBase is non-0, we should prefix the output with
426      // "(CastToBase*)".
427      Out << " + 1";
428      if (IsReference)
429        Out << ')';
430    }
431    return;
432  }
433  case APValue::Array: {
434    const ArrayType *AT = Ctx.getAsArrayType(Ty);
435    QualType ElemTy = AT->getElementType();
436    Out << '{';
437    if (unsigned N = getArrayInitializedElts()) {
438      getArrayInitializedElt(0).printPretty(Out, Ctx, ElemTy);
439      for (unsigned I = 1; I != N; ++I) {
440        Out << ", ";
441        if (I == 10) {
442          // Avoid printing out the entire contents of large arrays.
443          Out << "...";
444          break;
445        }
446        getArrayInitializedElt(I).printPretty(Out, Ctx, ElemTy);
447      }
448    }
449    Out << '}';
450    return;
451  }
452  case APValue::Struct: {
453    Out << '{';
454    const RecordDecl *RD = Ty->getAs<RecordType>()->getDecl();
455    bool First = true;
456    if (unsigned N = getStructNumBases()) {
457      const CXXRecordDecl *CD = cast<CXXRecordDecl>(RD);
458      CXXRecordDecl::base_class_const_iterator BI = CD->bases_begin();
459      for (unsigned I = 0; I != N; ++I, ++BI) {
460        assert(BI != CD->bases_end());
461        if (!First)
462          Out << ", ";
463        getStructBase(I).printPretty(Out, Ctx, BI->getType());
464        First = false;
465      }
466    }
467    for (RecordDecl::field_iterator FI = RD->field_begin();
468         FI != RD->field_end(); ++FI) {
469      if (!First)
470        Out << ", ";
471      if (FI->isUnnamedBitfield()) continue;
472      getStructField(FI->getFieldIndex()).
473        printPretty(Out, Ctx, FI->getType());
474      First = false;
475    }
476    Out << '}';
477    return;
478  }
479  case APValue::Union:
480    Out << '{';
481    if (const FieldDecl *FD = getUnionField()) {
482      Out << "." << *FD << " = ";
483      getUnionValue().printPretty(Out, Ctx, FD->getType());
484    }
485    Out << '}';
486    return;
487  case APValue::MemberPointer:
488    // FIXME: This is not enough to unambiguously identify the member in a
489    // multiple-inheritance scenario.
490    if (const ValueDecl *VD = getMemberPointerDecl()) {
491      Out << '&' << *cast<CXXRecordDecl>(VD->getDeclContext()) << "::" << *VD;
492      return;
493    }
494    Out << "0";
495    return;
496  case APValue::AddrLabelDiff:
497    Out << "&&" << getAddrLabelDiffLHS()->getLabel()->getName();
498    Out << " - ";
499    Out << "&&" << getAddrLabelDiffRHS()->getLabel()->getName();
500    return;
501  }
502  llvm_unreachable("Unknown APValue kind!");
503}
504
505std::string APValue::getAsString(ASTContext &Ctx, QualType Ty) const {
506  std::string Result;
507  llvm::raw_string_ostream Out(Result);
508  printPretty(Out, Ctx, Ty);
509  Out.flush();
510  return Result;
511}
512
513const APValue::LValueBase APValue::getLValueBase() const {
514  assert(isLValue() && "Invalid accessor");
515  return ((const LV*)(const void*)Data)->BaseAndIsOnePastTheEnd.getPointer();
516}
517
518bool APValue::isLValueOnePastTheEnd() const {
519  assert(isLValue() && "Invalid accessor");
520  return ((const LV*)(const void*)Data)->BaseAndIsOnePastTheEnd.getInt();
521}
522
523CharUnits &APValue::getLValueOffset() {
524  assert(isLValue() && "Invalid accessor");
525  return ((LV*)(void*)Data)->Offset;
526}
527
528bool APValue::hasLValuePath() const {
529  assert(isLValue() && "Invalid accessor");
530  return ((const LV*)(const char*)Data)->hasPath();
531}
532
533ArrayRef<APValue::LValuePathEntry> APValue::getLValuePath() const {
534  assert(isLValue() && hasLValuePath() && "Invalid accessor");
535  const LV &LVal = *((const LV*)(const char*)Data);
536  return ArrayRef<LValuePathEntry>(LVal.getPath(), LVal.PathLength);
537}
538
539unsigned APValue::getLValueCallIndex() const {
540  assert(isLValue() && "Invalid accessor");
541  return ((const LV*)(const char*)Data)->CallIndex;
542}
543
544void APValue::setLValue(LValueBase B, const CharUnits &O, NoLValuePath,
545                        unsigned CallIndex) {
546  assert(isLValue() && "Invalid accessor");
547  LV &LVal = *((LV*)(char*)Data);
548  LVal.BaseAndIsOnePastTheEnd.setPointer(B);
549  LVal.BaseAndIsOnePastTheEnd.setInt(false);
550  LVal.Offset = O;
551  LVal.CallIndex = CallIndex;
552  LVal.resizePath((unsigned)-1);
553}
554
555void APValue::setLValue(LValueBase B, const CharUnits &O,
556                        ArrayRef<LValuePathEntry> Path, bool IsOnePastTheEnd,
557                        unsigned CallIndex) {
558  assert(isLValue() && "Invalid accessor");
559  LV &LVal = *((LV*)(char*)Data);
560  LVal.BaseAndIsOnePastTheEnd.setPointer(B);
561  LVal.BaseAndIsOnePastTheEnd.setInt(IsOnePastTheEnd);
562  LVal.Offset = O;
563  LVal.CallIndex = CallIndex;
564  LVal.resizePath(Path.size());
565  memcpy(LVal.getPath(), Path.data(), Path.size() * sizeof(LValuePathEntry));
566}
567
568const ValueDecl *APValue::getMemberPointerDecl() const {
569  assert(isMemberPointer() && "Invalid accessor");
570  const MemberPointerData &MPD = *((const MemberPointerData*)(const char*)Data);
571  return MPD.MemberAndIsDerivedMember.getPointer();
572}
573
574bool APValue::isMemberPointerToDerivedMember() const {
575  assert(isMemberPointer() && "Invalid accessor");
576  const MemberPointerData &MPD = *((const MemberPointerData*)(const char*)Data);
577  return MPD.MemberAndIsDerivedMember.getInt();
578}
579
580ArrayRef<const CXXRecordDecl*> APValue::getMemberPointerPath() const {
581  assert(isMemberPointer() && "Invalid accessor");
582  const MemberPointerData &MPD = *((const MemberPointerData*)(const char*)Data);
583  return ArrayRef<const CXXRecordDecl*>(MPD.getPath(), MPD.PathLength);
584}
585
586void APValue::MakeLValue() {
587  assert(isUninit() && "Bad state change");
588  assert(sizeof(LV) <= MaxSize && "LV too big");
589  new ((void*)(char*)Data) LV();
590  Kind = LValue;
591}
592
593void APValue::MakeArray(unsigned InitElts, unsigned Size) {
594  assert(isUninit() && "Bad state change");
595  new ((void*)(char*)Data) Arr(InitElts, Size);
596  Kind = Array;
597}
598
599void APValue::MakeMemberPointer(const ValueDecl *Member, bool IsDerivedMember,
600                                ArrayRef<const CXXRecordDecl*> Path) {
601  assert(isUninit() && "Bad state change");
602  MemberPointerData *MPD = new ((void*)(char*)Data) MemberPointerData;
603  Kind = MemberPointer;
604  MPD->MemberAndIsDerivedMember.setPointer(Member);
605  MPD->MemberAndIsDerivedMember.setInt(IsDerivedMember);
606  MPD->resizePath(Path.size());
607  memcpy(MPD->getPath(), Path.data(), Path.size()*sizeof(const CXXRecordDecl*));
608}
609