clang/lib/AST/APValue.cpp

   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 "Linkage.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/ExprCXX.h"
  20 #include "clang/AST/Type.h"
  21 #include "llvm/Support/ErrorHandling.h"
  22 #include "llvm/Support/raw_ostream.h"
  23 using namespace clang;
  24
  25 /// The identity of a type_info object depends on the canonical unqualified
  26 /// type only.
  27 TypeInfoLValue::TypeInfoLValue(const Type *T)
  28     : T(T->getCanonicalTypeUnqualified().getTypePtr()) {}
  29
  30 void TypeInfoLValue::print(llvm::raw_ostream &Out,
  31                            const PrintingPolicy &Policy) const {
  32   Out << "typeid(";
  33   QualType(getType(), 0).print(Out, Policy);
  34   Out << ")";
  35 }
  36
  37 static_assert(
  38     1 << llvm::PointerLikeTypeTraits<TypeInfoLValue>::NumLowBitsAvailable <=
  39         alignof(Type),
  40     "Type is insufficiently aligned");
  41
  42 APValue::LValueBase::LValueBase(const ValueDecl *P, unsigned I, unsigned V)
  43     : Ptr(P ? cast<ValueDecl>(P->getCanonicalDecl()) : nullptr), Local{I, V} {}
  44 APValue::LValueBase::LValueBase(const Expr *P, unsigned I, unsigned V)
  45     : Ptr(P), Local{I, V} {}
  46
  47 APValue::LValueBase APValue::LValueBase::getDynamicAlloc(DynamicAllocLValue LV,
  48                                                          QualType Type) {
  49   LValueBase Base;
  50   Base.Ptr = LV;
  51   Base.DynamicAllocType = Type.getAsOpaquePtr();
  52   return Base;
  53 }
  54
  55 APValue::LValueBase APValue::LValueBase::getTypeInfo(TypeInfoLValue LV,
  56                                                      QualType TypeInfo) {
  57   LValueBase Base;
  58   Base.Ptr = LV;
  59   Base.TypeInfoType = TypeInfo.getAsOpaquePtr();
  60   return Base;
  61 }
  62
  63 QualType APValue::LValueBase::getType() const {
  64   if (!*this) return QualType();
  65   if (const ValueDecl *D = dyn_cast<const ValueDecl*>()) {
  66     // FIXME: It's unclear where we're supposed to take the type from, and
  67     // this actually matters for arrays of unknown bound. Eg:
  68     //
  69     // extern int arr[]; void f() { extern int arr[3]; };
  70     // constexpr int *p = &arr[1]; // valid?
  71     //
  72     // For now, we take the most complete type we can find.
  73     for (auto *Redecl = cast<ValueDecl>(D->getMostRecentDecl()); Redecl;
  74          Redecl = cast_or_null<ValueDecl>(Redecl->getPreviousDecl())) {
  75       QualType T = Redecl->getType();
  76       if (!T->isIncompleteArrayType())
  77         return T;
  78     }
  79     return D->getType();
  80   }
  81
  82   if (is<TypeInfoLValue>())
  83     return getTypeInfoType();
  84
  85   if (is<DynamicAllocLValue>())
  86     return getDynamicAllocType();
  87
  88   const Expr *Base = get<const Expr*>();
  89
  90   // For a materialized temporary, the type of the temporary we materialized
  91   // may not be the type of the expression.
  92   if (const MaterializeTemporaryExpr *MTE =
  93           clang::dyn_cast<MaterializeTemporaryExpr>(Base)) {
  94     SmallVector<const Expr *, 2> CommaLHSs;
  95     SmallVector<SubobjectAdjustment, 2> Adjustments;
  96     const Expr *Temp = MTE->getSubExpr();
  97     const Expr *Inner = Temp->skipRValueSubobjectAdjustments(CommaLHSs,
  98                                                              Adjustments);
  99     // Keep any cv-qualifiers from the reference if we generated a temporary
 100     // for it directly. Otherwise use the type after adjustment.
 101     if (!Adjustments.empty())
 102       return Inner->getType();
 103   }
 104
 105   return Base->getType();
 106 }
 107
 108 unsigned APValue::LValueBase::getCallIndex() const {
 109   return (is<TypeInfoLValue>() || is<DynamicAllocLValue>()) ? 0
 110                                                             : Local.CallIndex;
 111 }
 112
 113 unsigned APValue::LValueBase::getVersion() const {
 114   return (is<TypeInfoLValue>() || is<DynamicAllocLValue>()) ? 0 : Local.Version;
 115 }
 116
 117 QualType APValue::LValueBase::getTypeInfoType() const {
 118   assert(is<TypeInfoLValue>() && "not a type_info lvalue");
 119   return QualType::getFromOpaquePtr(TypeInfoType);
 120 }
 121
 122 QualType APValue::LValueBase::getDynamicAllocType() const {
 123   assert(is<DynamicAllocLValue>() && "not a dynamic allocation lvalue");
 124   return QualType::getFromOpaquePtr(DynamicAllocType);
 125 }
 126
 127 void APValue::LValueBase::Profile(llvm::FoldingSetNodeID &ID) const {
 128   ID.AddPointer(Ptr.getOpaqueValue());
 129   if (is<TypeInfoLValue>() || is<DynamicAllocLValue>())
 130     return;
 131   ID.AddInteger(Local.CallIndex);
 132   ID.AddInteger(Local.Version);
 133 }
 134
 135 namespace clang {
 136 bool operator==(const APValue::LValueBase &LHS,
 137                 const APValue::LValueBase &RHS) {
 138   if (LHS.Ptr != RHS.Ptr)
 139     return false;
 140   if (LHS.is<TypeInfoLValue>() || LHS.is<DynamicAllocLValue>())
 141     return true;
 142   return LHS.Local.CallIndex == RHS.Local.CallIndex &&
 143          LHS.Local.Version == RHS.Local.Version;
 144 }
 145 }
 146
 147 APValue::LValuePathEntry::LValuePathEntry(BaseOrMemberType BaseOrMember) {
 148   if (const Decl *D = BaseOrMember.getPointer())
 149     BaseOrMember.setPointer(D->getCanonicalDecl());
 150   Value = reinterpret_cast<uintptr_t>(BaseOrMember.getOpaqueValue());
 151 }
 152
 153 void APValue::LValuePathEntry::Profile(llvm::FoldingSetNodeID &ID) const {
 154   ID.AddInteger(Value);
 155 }
 156
 157 APValue::LValuePathSerializationHelper::LValuePathSerializationHelper(
 158     ArrayRef<LValuePathEntry> Path, QualType ElemTy)
 159     : ElemTy((const void *)ElemTy.getTypePtrOrNull()), Path(Path) {}
 160
 161 QualType APValue::LValuePathSerializationHelper::getType() {
 162   return QualType::getFromOpaquePtr(ElemTy);
 163 }
 164
 165 namespace {
 166   struct LVBase {
 167     APValue::LValueBase Base;
 168     CharUnits Offset;
 169     unsigned PathLength;
 170     bool IsNullPtr : 1;
 171     bool IsOnePastTheEnd : 1;
 172   };
 173 }
 174
 175 void *APValue::LValueBase::getOpaqueValue() const {
 176   return Ptr.getOpaqueValue();
 177 }
 178
 179 bool APValue::LValueBase::isNull() const {
 180   return Ptr.isNull();
 181 }
 182
 183 APValue::LValueBase::operator bool () const {
 184   return static_cast<bool>(Ptr);
 185 }
 186
 187 clang::APValue::LValueBase
 188 llvm::DenseMapInfo<clang::APValue::LValueBase>::getEmptyKey() {
 189   clang::APValue::LValueBase B;
 190   B.Ptr = DenseMapInfo<const ValueDecl*>::getEmptyKey();
 191   return B;
 192 }
 193
 194 clang::APValue::LValueBase
 195 llvm::DenseMapInfo<clang::APValue::LValueBase>::getTombstoneKey() {
 196   clang::APValue::LValueBase B;
 197   B.Ptr = DenseMapInfo<const ValueDecl*>::getTombstoneKey();
 198   return B;
 199 }
 200
 201 namespace clang {
 202 llvm::hash_code hash_value(const APValue::LValueBase &Base) {
 203   if (Base.is<TypeInfoLValue>() || Base.is<DynamicAllocLValue>())
 204     return llvm::hash_value(Base.getOpaqueValue());
 205   return llvm::hash_combine(Base.getOpaqueValue(), Base.getCallIndex(),
 206                             Base.getVersion());
 207 }
 208 }
 209
 210 unsigned llvm::DenseMapInfo<clang::APValue::LValueBase>::getHashValue(
 211     const clang::APValue::LValueBase &Base) {
 212   return hash_value(Base);
 213 }
 214
 215 bool llvm::DenseMapInfo<clang::APValue::LValueBase>::isEqual(
 216     const clang::APValue::LValueBase &LHS,
 217     const clang::APValue::LValueBase &RHS) {
 218   return LHS == RHS;
 219 }
 220
 221 struct APValue::LV : LVBase {
 222   static const unsigned InlinePathSpace =
 223       (DataSize - sizeof(LVBase)) / sizeof(LValuePathEntry);
 224
 225   /// Path - The sequence of base classes, fields and array indices to follow to
 226   /// walk from Base to the subobject. When performing GCC-style folding, there
 227   /// may not be such a path.
 228   union {
 229     LValuePathEntry Path[InlinePathSpace];
 230     LValuePathEntry *PathPtr;
 231   };
 232
 233   LV() { PathLength = (unsigned)-1; }
 234   ~LV() { resizePath(0); }
 235
 236   void resizePath(unsigned Length) {
 237     if (Length == PathLength)
 238       return;
 239     if (hasPathPtr())
 240       delete [] PathPtr;
 241     PathLength = Length;
 242     if (hasPathPtr())
 243       PathPtr = new LValuePathEntry[Length];
 244   }
 245
 246   bool hasPath() const { return PathLength != (unsigned)-1; }
 247   bool hasPathPtr() const { return hasPath() && PathLength > InlinePathSpace; }
 248
 249   LValuePathEntry *getPath() { return hasPathPtr() ? PathPtr : Path; }
 250   const LValuePathEntry *getPath() const {
 251     return hasPathPtr() ? PathPtr : Path;
 252   }
 253 };
 254
 255 namespace {
 256   struct MemberPointerBase {
 257     llvm::PointerIntPair<const ValueDecl*, 1, bool> MemberAndIsDerivedMember;
 258     unsigned PathLength;
 259   };
 260 }
 261
 262 struct APValue::MemberPointerData : MemberPointerBase {
 263   static const unsigned InlinePathSpace =
 264       (DataSize - sizeof(MemberPointerBase)) / sizeof(const CXXRecordDecl*);
 265   typedef const CXXRecordDecl *PathElem;
 266   union {
 267     PathElem Path[InlinePathSpace];
 268     PathElem *PathPtr;
 269   };
 270
 271   MemberPointerData() { PathLength = 0; }
 272   ~MemberPointerData() { resizePath(0); }
 273
 274   void resizePath(unsigned Length) {
 275     if (Length == PathLength)
 276       return;
 277     if (hasPathPtr())
 278       delete [] PathPtr;
 279     PathLength = Length;
 280     if (hasPathPtr())
 281       PathPtr = new PathElem[Length];
 282   }
 283
 284   bool hasPathPtr() const { return PathLength > InlinePathSpace; }
 285
 286   PathElem *getPath() { return hasPathPtr() ? PathPtr : Path; }
 287   const PathElem *getPath() const {
 288     return hasPathPtr() ? PathPtr : Path;
 289   }
 290 };
 291
 292 // FIXME: Reduce the malloc traffic here.
 293
 294 APValue::Arr::Arr(unsigned NumElts, unsigned Size) :
 295   Elts(new APValue[NumElts + (NumElts != Size ? 1 : 0)]),
 296   NumElts(NumElts), ArrSize(Size) {}
 297 APValue::Arr::~Arr() { delete [] Elts; }
 298
 299 APValue::StructData::StructData(unsigned NumBases, unsigned NumFields) :
 300   Elts(new APValue[NumBases+NumFields]),
 301   NumBases(NumBases), NumFields(NumFields) {}
 302 APValue::StructData::~StructData() {
 303   delete [] Elts;
 304 }
 305
 306 APValue::UnionData::UnionData() : Field(nullptr), Value(new APValue) {}
 307 APValue::UnionData::~UnionData () {
 308   delete Value;
 309 }
 310
 311 APValue::APValue(const APValue &RHS) : Kind(None) {
 312   switch (RHS.getKind()) {
 313   case None:
 314   case Indeterminate:
 315     Kind = RHS.getKind();
 316     break;
 317   case Int:
 318     MakeInt();
 319     setInt(RHS.getInt());
 320     break;
 321   case Float:
 322     MakeFloat();
 323     setFloat(RHS.getFloat());
 324     break;
 325   case FixedPoint: {
 326     APFixedPoint FXCopy = RHS.getFixedPoint();
 327     MakeFixedPoint(std::move(FXCopy));
 328     break;
 329   }
 330   case Vector:
 331     MakeVector();
 332     setVector(((const Vec *)(const char *)&RHS.Data)->Elts,
 333               RHS.getVectorLength());
 334     break;
 335   case ComplexInt:
 336     MakeComplexInt();
 337     setComplexInt(RHS.getComplexIntReal(), RHS.getComplexIntImag());
 338     break;
 339   case ComplexFloat:
 340     MakeComplexFloat();
 341     setComplexFloat(RHS.getComplexFloatReal(), RHS.getComplexFloatImag());
 342     break;
 343   case LValue:
 344     MakeLValue();
 345     if (RHS.hasLValuePath())
 346       setLValue(RHS.getLValueBase(), RHS.getLValueOffset(), RHS.getLValuePath(),
 347                 RHS.isLValueOnePastTheEnd(), RHS.isNullPointer());
 348     else
 349       setLValue(RHS.getLValueBase(), RHS.getLValueOffset(), NoLValuePath(),
 350                 RHS.isNullPointer());
 351     break;
 352   case Array:
 353     MakeArray(RHS.getArrayInitializedElts(), RHS.getArraySize());
 354     for (unsigned I = 0, N = RHS.getArrayInitializedElts(); I != N; ++I)
 355       getArrayInitializedElt(I) = RHS.getArrayInitializedElt(I);
 356     if (RHS.hasArrayFiller())
 357       getArrayFiller() = RHS.getArrayFiller();
 358     break;
 359   case Struct:
 360     MakeStruct(RHS.getStructNumBases(), RHS.getStructNumFields());
 361     for (unsigned I = 0, N = RHS.getStructNumBases(); I != N; ++I)
 362       getStructBase(I) = RHS.getStructBase(I);
 363     for (unsigned I = 0, N = RHS.getStructNumFields(); I != N; ++I)
 364       getStructField(I) = RHS.getStructField(I);
 365     break;
 366   case Union:
 367     MakeUnion();
 368     setUnion(RHS.getUnionField(), RHS.getUnionValue());
 369     break;
 370   case MemberPointer:
 371     MakeMemberPointer(RHS.getMemberPointerDecl(),
 372                       RHS.isMemberPointerToDerivedMember(),
 373                       RHS.getMemberPointerPath());
 374     break;
 375   case AddrLabelDiff:
 376     MakeAddrLabelDiff();
 377     setAddrLabelDiff(RHS.getAddrLabelDiffLHS(), RHS.getAddrLabelDiffRHS());
 378     break;
 379   }
 380 }
 381
 382 APValue::APValue(APValue &&RHS) : Kind(RHS.Kind), Data(RHS.Data) {
 383   RHS.Kind = None;
 384 }
 385
 386 APValue &APValue::operator=(const APValue &RHS) {
 387   if (this != &RHS)
 388     *this = APValue(RHS);
 389   return *this;
 390 }
 391
 392 APValue &APValue::operator=(APValue &&RHS) {
 393   if (Kind != None && Kind != Indeterminate)
 394     DestroyDataAndMakeUninit();
 395   Kind = RHS.Kind;
 396   Data = RHS.Data;
 397   RHS.Kind = None;
 398   return *this;
 399 }
 400
 401 void APValue::DestroyDataAndMakeUninit() {
 402   if (Kind == Int)
 403     ((APSInt *)(char *)&Data)->~APSInt();
 404   else if (Kind == Float)
 405     ((APFloat *)(char *)&Data)->~APFloat();
 406   else if (Kind == FixedPoint)
 407     ((APFixedPoint *)(char *)&Data)->~APFixedPoint();
 408   else if (Kind == Vector)
 409     ((Vec *)(char *)&Data)->~Vec();
 410   else if (Kind == ComplexInt)
 411     ((ComplexAPSInt *)(char *)&Data)->~ComplexAPSInt();
 412   else if (Kind == ComplexFloat)
 413     ((ComplexAPFloat *)(char *)&Data)->~ComplexAPFloat();
 414   else if (Kind == LValue)
 415     ((LV *)(char *)&Data)->~LV();
 416   else if (Kind == Array)
 417     ((Arr *)(char *)&Data)->~Arr();
 418   else if (Kind == Struct)
 419     ((StructData *)(char *)&Data)->~StructData();
 420   else if (Kind == Union)
 421     ((UnionData *)(char *)&Data)->~UnionData();
 422   else if (Kind == MemberPointer)
 423     ((MemberPointerData *)(char *)&Data)->~MemberPointerData();
 424   else if (Kind == AddrLabelDiff)
 425     ((AddrLabelDiffData *)(char *)&Data)->~AddrLabelDiffData();
 426   Kind = None;
 427 }
 428
 429 bool APValue::needsCleanup() const {
 430   switch (getKind()) {
 431   case None:
 432   case Indeterminate:
 433   case AddrLabelDiff:
 434     return false;
 435   case Struct:
 436   case Union:
 437   case Array:
 438   case Vector:
 439     return true;
 440   case Int:
 441     return getInt().needsCleanup();
 442   case Float:
 443     return getFloat().needsCleanup();
 444   case FixedPoint:
 445     return getFixedPoint().getValue().needsCleanup();
 446   case ComplexFloat:
 447     assert(getComplexFloatImag().needsCleanup() ==
 448                getComplexFloatReal().needsCleanup() &&
 449            "In _Complex float types, real and imaginary values always have the "
 450            "same size.");
 451     return getComplexFloatReal().needsCleanup();
 452   case ComplexInt:
 453     assert(getComplexIntImag().needsCleanup() ==
 454                getComplexIntReal().needsCleanup() &&
 455            "In _Complex int types, real and imaginary values must have the "
 456            "same size.");
 457     return getComplexIntReal().needsCleanup();
 458   case LValue:
 459     return reinterpret_cast<const LV *>(&Data)->hasPathPtr();
 460   case MemberPointer:
 461     return reinterpret_cast<const MemberPointerData *>(&Data)->hasPathPtr();
 462   }
 463   llvm_unreachable("Unknown APValue kind!");
 464 }
 465
 466 void APValue::swap(APValue &RHS) {
 467   std::swap(Kind, RHS.Kind);
 468   std::swap(Data, RHS.Data);
 469 }
 470
 471 /// Profile the value of an APInt, excluding its bit-width.
 472 static void profileIntValue(llvm::FoldingSetNodeID &ID, const llvm::APInt &V) {
 473   for (unsigned I = 0, N = V.getBitWidth(); I < N; I += 32)
 474     ID.AddInteger((uint32_t)V.extractBitsAsZExtValue(std::min(32u, N - I), I));
 475 }
 476
 477 void APValue::Profile(llvm::FoldingSetNodeID &ID) const {
 478   // Note that our profiling assumes that only APValues of the same type are
 479   // ever compared. As a result, we don't consider collisions that could only
 480   // happen if the types are different. (For example, structs with different
 481   // numbers of members could profile the same.)
 482
 483   ID.AddInteger(Kind);
 484
 485   switch (Kind) {
 486   case None:
 487   case Indeterminate:
 488     return;
 489
 490   case AddrLabelDiff:
 491     ID.AddPointer(getAddrLabelDiffLHS()->getLabel()->getCanonicalDecl());
 492     ID.AddPointer(getAddrLabelDiffRHS()->getLabel()->getCanonicalDecl());
 493     return;
 494
 495   case Struct:
 496     for (unsigned I = 0, N = getStructNumBases(); I != N; ++I)
 497       getStructBase(I).Profile(ID);
 498     for (unsigned I = 0, N = getStructNumFields(); I != N; ++I)
 499       getStructField(I).Profile(ID);
 500     return;
 501
 502   case Union:
 503     if (!getUnionField()) {
 504       ID.AddInteger(0);
 505       return;
 506     }
 507     ID.AddInteger(getUnionField()->getFieldIndex() + 1);
 508     getUnionValue().Profile(ID);
 509     return;
 510
 511   case Array: {
 512     if (getArraySize() == 0)
 513       return;
 514
 515     // The profile should not depend on whether the array is expanded or
 516     // not, but we don't want to profile the array filler many times for
 517     // a large array. So treat all equal trailing elements as the filler.
 518     // Elements are profiled in reverse order to support this, and the
 519     // first profiled element is followed by a count. For example:
 520     //
 521     //   ['a', 'c', 'x', 'x', 'x'] is profiled as
 522     //   [5, 'x', 3, 'c', 'a']
 523     llvm::FoldingSetNodeID FillerID;
 524     (hasArrayFiller() ? getArrayFiller()
 525                       : getArrayInitializedElt(getArrayInitializedElts() - 1))
 526         .Profile(FillerID);
 527     ID.AddNodeID(FillerID);
 528     unsigned NumFillers = getArraySize() - getArrayInitializedElts();
 529     unsigned N = getArrayInitializedElts();
 530
 531     // Count the number of elements equal to the last one. This loop ends
 532     // by adding an integer indicating the number of such elements, with
 533     // N set to the number of elements left to profile.
 534     while (true) {
 535       if (N == 0) {
 536         // All elements are fillers.
 537         assert(NumFillers == getArraySize());
 538         ID.AddInteger(NumFillers);
 539         break;
 540       }
 541
 542       // No need to check if the last element is equal to the last
 543       // element.
 544       if (N != getArraySize()) {
 545         llvm::FoldingSetNodeID ElemID;
 546         getArrayInitializedElt(N - 1).Profile(ElemID);
 547         if (ElemID != FillerID) {
 548           ID.AddInteger(NumFillers);
 549           ID.AddNodeID(ElemID);
 550           --N;
 551           break;
 552         }
 553       }
 554
 555       // This is a filler.
 556       ++NumFillers;
 557       --N;
 558     }
 559
 560     // Emit the remaining elements.
 561     for (; N != 0; --N)
 562       getArrayInitializedElt(N - 1).Profile(ID);
 563     return;
 564   }
 565
 566   case Vector:
 567     for (unsigned I = 0, N = getVectorLength(); I != N; ++I)
 568       getVectorElt(I).Profile(ID);
 569     return;
 570
 571   case Int:
 572     profileIntValue(ID, getInt());
 573     return;
 574
 575   case Float:
 576     profileIntValue(ID, getFloat().bitcastToAPInt());
 577     return;
 578
 579   case FixedPoint:
 580     profileIntValue(ID, getFixedPoint().getValue());
 581     return;
 582
 583   case ComplexFloat:
 584     profileIntValue(ID, getComplexFloatReal().bitcastToAPInt());
 585     profileIntValue(ID, getComplexFloatImag().bitcastToAPInt());
 586     return;
 587
 588   case ComplexInt:
 589     profileIntValue(ID, getComplexIntReal());
 590     profileIntValue(ID, getComplexIntImag());
 591     return;
 592
 593   case LValue:
 594     getLValueBase().Profile(ID);
 595     ID.AddInteger(getLValueOffset().getQuantity());
 596     ID.AddInteger((isNullPointer() ? 1 : 0) |
 597                   (isLValueOnePastTheEnd() ? 2 : 0) |
 598                   (hasLValuePath() ? 4 : 0));
 599     if (hasLValuePath()) {
 600       ID.AddInteger(getLValuePath().size());
 601       // For uniqueness, we only need to profile the entries corresponding
 602       // to union members, but we don't have the type here so we don't know
 603       // how to interpret the entries.
 604       for (LValuePathEntry E : getLValuePath())
 605         E.Profile(ID);
 606     }
 607     return;
 608
 609   case MemberPointer:
 610     ID.AddPointer(getMemberPointerDecl());
 611     ID.AddInteger(isMemberPointerToDerivedMember());
 612     for (const CXXRecordDecl *D : getMemberPointerPath())
 613       ID.AddPointer(D);
 614     return;
 615   }
 616
 617   llvm_unreachable("Unknown APValue kind!");
 618 }
 619
 620 static double GetApproxValue(const llvm::APFloat &F) {
 621   llvm::APFloat V = F;
 622   bool ignored;
 623   V.convert(llvm::APFloat::IEEEdouble(), llvm::APFloat::rmNearestTiesToEven,
 624             &ignored);
 625   return V.convertToDouble();
 626 }
 627
 628 static bool TryPrintAsStringLiteral(raw_ostream &Out,
 629                                     const PrintingPolicy &Policy,
 630                                     const ArrayType *ATy,
 631                                     ArrayRef<APValue> Inits) {
 632   if (Inits.empty())
 633     return false;
 634
 635   QualType Ty = ATy->getElementType();
 636   if (!Ty->isAnyCharacterType())
 637     return false;
 638
 639   // Nothing we can do about a sequence that is not null-terminated
 640   if (!Inits.back().isInt() || !Inits.back().getInt().isZero())
 641     return false;
 642
 643   Inits = Inits.drop_back();
 644
 645   llvm::SmallString<40> Buf;
 646   Buf.push_back('"');
 647
 648   // Better than printing a two-digit sequence of 10 integers.
 649   constexpr size_t MaxN = 36;
 650   StringRef Ellipsis;
 651   if (Inits.size() > MaxN && !Policy.EntireContentsOfLargeArray) {
 652     Ellipsis = "[...]";
 653     Inits =
 654         Inits.take_front(std::min(MaxN - Ellipsis.size() / 2, Inits.size()));
 655   }
 656
 657   for (auto &Val : Inits) {
 658     if (!Val.isInt())
 659       return false;
 660     int64_t Char64 = Val.getInt().getExtValue();
 661     if (!isASCII(Char64))
 662       return false; // Bye bye, see you in integers.
 663     auto Ch = static_cast<unsigned char>(Char64);
 664     // The diagnostic message is 'quoted'
 665     StringRef Escaped = escapeCStyle<EscapeChar::SingleAndDouble>(Ch);
 666     if (Escaped.empty()) {
 667       if (!isPrintable(Ch))
 668         return false;
 669       Buf.emplace_back(Ch);
 670     } else {
 671       Buf.append(Escaped);
 672     }
 673   }
 674
 675   Buf.append(Ellipsis);
 676   Buf.push_back('"');
 677
 678   if (Ty->isWideCharType())
 679     Out << 'L';
 680   else if (Ty->isChar8Type())
 681     Out << "u8";
 682   else if (Ty->isChar16Type())
 683     Out << 'u';
 684   else if (Ty->isChar32Type())
 685     Out << 'U';
 686
 687   Out << Buf;
 688   return true;
 689 }
 690
 691 void APValue::printPretty(raw_ostream &Out, const ASTContext &Ctx,
 692                           QualType Ty) const {
 693   printPretty(Out, Ctx.getPrintingPolicy(), Ty, &Ctx);
 694 }
 695
 696 void APValue::printPretty(raw_ostream &Out, const PrintingPolicy &Policy,
 697                           QualType Ty, const ASTContext *Ctx) const {
 698   // There are no objects of type 'void', but values of this type can be
 699   // returned from functions.
 700   if (Ty->isVoidType()) {
 701     Out << "void()";
 702     return;
 703   }
 704
 705   switch (getKind()) {
 706   case APValue::None:
 707     Out << "<out of lifetime>";
 708     return;
 709   case APValue::Indeterminate:
 710     Out << "<uninitialized>";
 711     return;
 712   case APValue::Int:
 713     if (Ty->isBooleanType())
 714       Out << (getInt().getBoolValue() ? "true" : "false");
 715     else
 716       Out << getInt();
 717     return;
 718   case APValue::Float:
 719     Out << GetApproxValue(getFloat());
 720     return;
 721   case APValue::FixedPoint:
 722     Out << getFixedPoint();
 723     return;
 724   case APValue::Vector: {
 725     Out << '{';
 726     QualType ElemTy = Ty->castAs<VectorType>()->getElementType();
 727     getVectorElt(0).printPretty(Out, Policy, ElemTy, Ctx);
 728     for (unsigned i = 1; i != getVectorLength(); ++i) {
 729       Out << ", ";
 730       getVectorElt(i).printPretty(Out, Policy, ElemTy, Ctx);
 731     }
 732     Out << '}';
 733     return;
 734   }
 735   case APValue::ComplexInt:
 736     Out << getComplexIntReal() << "+" << getComplexIntImag() << "i";
 737     return;
 738   case APValue::ComplexFloat:
 739     Out << GetApproxValue(getComplexFloatReal()) << "+"
 740         << GetApproxValue(getComplexFloatImag()) << "i";
 741     return;
 742   case APValue::LValue: {
 743     bool IsReference = Ty->isReferenceType();
 744     QualType InnerTy
 745       = IsReference ? Ty.getNonReferenceType() : Ty->getPointeeType();
 746     if (InnerTy.isNull())
 747       InnerTy = Ty;
 748
 749     LValueBase Base = getLValueBase();
 750     if (!Base) {
 751       if (isNullPointer()) {
 752         Out << (Policy.Nullptr ? "nullptr" : "0");
 753       } else if (IsReference) {
 754         Out << "*(" << InnerTy.stream(Policy) << "*)"
 755             << getLValueOffset().getQuantity();
 756       } else {
 757         Out << "(" << Ty.stream(Policy) << ")"
 758             << getLValueOffset().getQuantity();
 759       }
 760       return;
 761     }
 762
 763     if (!hasLValuePath()) {
 764       // No lvalue path: just print the offset.
 765       CharUnits O = getLValueOffset();
 766       CharUnits S = Ctx ? Ctx->getTypeSizeInCharsIfKnown(InnerTy).value_or(
 767                               CharUnits::Zero())
 768                         : CharUnits::Zero();
 769       if (!O.isZero()) {
 770         if (IsReference)
 771           Out << "*(";
 772         if (S.isZero() || O % S) {
 773           Out << "(char*)";
 774           S = CharUnits::One();
 775         }
 776         Out << '&';
 777       } else if (!IsReference) {
 778         Out << '&';
 779       }
 780
 781       if (const ValueDecl *VD = Base.dyn_cast<const ValueDecl*>())
 782         Out << *VD;
 783       else if (TypeInfoLValue TI = Base.dyn_cast<TypeInfoLValue>()) {
 784         TI.print(Out, Policy);
 785       } else if (DynamicAllocLValue DA = Base.dyn_cast<DynamicAllocLValue>()) {
 786         Out << "{*new "
 787             << Base.getDynamicAllocType().stream(Policy) << "#"
 788             << DA.getIndex() << "}";
 789       } else {
 790         assert(Base.get<const Expr *>() != nullptr &&
 791                "Expecting non-null Expr");
 792         Base.get<const Expr*>()->printPretty(Out, nullptr, Policy);
 793       }
 794
 795       if (!O.isZero()) {
 796         Out << " + " << (O / S);
 797         if (IsReference)
 798           Out << ')';
 799       }
 800       return;
 801     }
 802
 803     // We have an lvalue path. Print it out nicely.
 804     if (!IsReference)
 805       Out << '&';
 806     else if (isLValueOnePastTheEnd())
 807       Out << "*(&";
 808
 809     QualType ElemTy = Base.getType();
 810     if (const ValueDecl *VD = Base.dyn_cast<const ValueDecl*>()) {
 811       Out << *VD;
 812     } else if (TypeInfoLValue TI = Base.dyn_cast<TypeInfoLValue>()) {
 813       TI.print(Out, Policy);
 814     } else if (DynamicAllocLValue DA = Base.dyn_cast<DynamicAllocLValue>()) {
 815       Out << "{*new " << Base.getDynamicAllocType().stream(Policy) << "#"
 816           << DA.getIndex() << "}";
 817     } else {
 818       const Expr *E = Base.get<const Expr*>();
 819       assert(E != nullptr && "Expecting non-null Expr");
 820       E->printPretty(Out, nullptr, Policy);
 821     }
 822
 823     ArrayRef<LValuePathEntry> Path = getLValuePath();
 824     const CXXRecordDecl *CastToBase = nullptr;
 825     for (unsigned I = 0, N = Path.size(); I != N; ++I) {
 826       if (ElemTy->isRecordType()) {
 827         // The lvalue refers to a class type, so the next path entry is a base
 828         // or member.
 829         const Decl *BaseOrMember = Path[I].getAsBaseOrMember().getPointer();
 830         if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(BaseOrMember)) {
 831           CastToBase = RD;
 832           // Leave ElemTy referring to the most-derived class. The actual type
 833           // doesn't matter except for array types.
 834         } else {
 835           const ValueDecl *VD = cast<ValueDecl>(BaseOrMember);
 836           Out << ".";
 837           if (CastToBase)
 838             Out << *CastToBase << "::";
 839           Out << *VD;
 840           ElemTy = VD->getType();
 841         }
 842       } else {
 843         // The lvalue must refer to an array.
 844         Out << '[' << Path[I].getAsArrayIndex() << ']';
 845         ElemTy = ElemTy->castAsArrayTypeUnsafe()->getElementType();
 846       }
 847     }
 848
 849     // Handle formatting of one-past-the-end lvalues.
 850     if (isLValueOnePastTheEnd()) {
 851       // FIXME: If CastToBase is non-0, we should prefix the output with
 852       // "(CastToBase*)".
 853       Out << " + 1";
 854       if (IsReference)
 855         Out << ')';
 856     }
 857     return;
 858   }
 859   case APValue::Array: {
 860     const ArrayType *AT = Ty->castAsArrayTypeUnsafe();
 861     unsigned N = getArrayInitializedElts();
 862     if (N != 0 && TryPrintAsStringLiteral(Out, Policy, AT,
 863                                           {&getArrayInitializedElt(0), N}))
 864       return;
 865     QualType ElemTy = AT->getElementType();
 866     Out << '{';
 867     unsigned I = 0;
 868     switch (N) {
 869     case 0:
 870       for (; I != N; ++I) {
 871         Out << ", ";
 872         if (I == 10 && !Policy.EntireContentsOfLargeArray) {
 873           Out << "...}";
 874           return;
 875         }
 876         [[fallthrough]];
 877       default:
 878         getArrayInitializedElt(I).printPretty(Out, Policy, ElemTy, Ctx);
 879       }
 880     }
 881     Out << '}';
 882     return;
 883   }
 884   case APValue::Struct: {
 885     Out << '{';
 886     const RecordDecl *RD = Ty->castAs<RecordType>()->getDecl();
 887     bool First = true;
 888     if (unsigned N = getStructNumBases()) {
 889       const CXXRecordDecl *CD = cast<CXXRecordDecl>(RD);
 890       CXXRecordDecl::base_class_const_iterator BI = CD->bases_begin();
 891       for (unsigned I = 0; I != N; ++I, ++BI) {
 892         assert(BI != CD->bases_end());
 893         if (!First)
 894           Out << ", ";
 895         getStructBase(I).printPretty(Out, Policy, BI->getType(), Ctx);
 896         First = false;
 897       }
 898     }
 899     for (const auto *FI : RD->fields()) {
 900       if (!First)
 901         Out << ", ";
 902       if (FI->isUnnamedBitfield()) continue;
 903       getStructField(FI->getFieldIndex()).
 904         printPretty(Out, Policy, FI->getType(), Ctx);
 905       First = false;
 906     }
 907     Out << '}';
 908     return;
 909   }
 910   case APValue::Union:
 911     Out << '{';
 912     if (const FieldDecl *FD = getUnionField()) {
 913       Out << "." << *FD << " = ";
 914       getUnionValue().printPretty(Out, Policy, FD->getType(), Ctx);
 915     }
 916     Out << '}';
 917     return;
 918   case APValue::MemberPointer:
 919     // FIXME: This is not enough to unambiguously identify the member in a
 920     // multiple-inheritance scenario.
 921     if (const ValueDecl *VD = getMemberPointerDecl()) {
 922       Out << '&' << *cast<CXXRecordDecl>(VD->getDeclContext()) << "::" << *VD;
 923       return;
 924     }
 925     Out << "0";
 926     return;
 927   case APValue::AddrLabelDiff:
 928     Out << "&&" << getAddrLabelDiffLHS()->getLabel()->getName();
 929     Out << " - ";
 930     Out << "&&" << getAddrLabelDiffRHS()->getLabel()->getName();
 931     return;
 932   }
 933   llvm_unreachable("Unknown APValue kind!");
 934 }
 935
 936 std::string APValue::getAsString(const ASTContext &Ctx, QualType Ty) const {
 937   std::string Result;
 938   llvm::raw_string_ostream Out(Result);
 939   printPretty(Out, Ctx, Ty);
 940   Out.flush();
 941   return Result;
 942 }
 943
 944 bool APValue::toIntegralConstant(APSInt &Result, QualType SrcTy,
 945                                  const ASTContext &Ctx) const {
 946   if (isInt()) {
 947     Result = getInt();
 948     return true;
 949   }
 950
 951   if (isLValue() && isNullPointer()) {
 952     Result = Ctx.MakeIntValue(Ctx.getTargetNullPointerValue(SrcTy), SrcTy);
 953     return true;
 954   }
 955
 956   if (isLValue() && !getLValueBase()) {
 957     Result = Ctx.MakeIntValue(getLValueOffset().getQuantity(), SrcTy);
 958     return true;
 959   }
 960
 961   return false;
 962 }
 963
 964 const APValue::LValueBase APValue::getLValueBase() const {
 965   assert(isLValue() && "Invalid accessor");
 966   return ((const LV *)(const void *)&Data)->Base;
 967 }
 968
 969 bool APValue::isLValueOnePastTheEnd() const {
 970   assert(isLValue() && "Invalid accessor");
 971   return ((const LV *)(const void *)&Data)->IsOnePastTheEnd;
 972 }
 973
 974 CharUnits &APValue::getLValueOffset() {
 975   assert(isLValue() && "Invalid accessor");
 976   return ((LV *)(void *)&Data)->Offset;
 977 }
 978
 979 bool APValue::hasLValuePath() const {
 980   assert(isLValue() && "Invalid accessor");
 981   return ((const LV *)(const char *)&Data)->hasPath();
 982 }
 983
 984 ArrayRef<APValue::LValuePathEntry> APValue::getLValuePath() const {
 985   assert(isLValue() && hasLValuePath() && "Invalid accessor");
 986   const LV &LVal = *((const LV *)(const char *)&Data);
 987   return llvm::makeArrayRef(LVal.getPath(), LVal.PathLength);
 988 }
 989
 990 unsigned APValue::getLValueCallIndex() const {
 991   assert(isLValue() && "Invalid accessor");
 992   return ((const LV *)(const char *)&Data)->Base.getCallIndex();
 993 }
 994
 995 unsigned APValue::getLValueVersion() const {
 996   assert(isLValue() && "Invalid accessor");
 997   return ((const LV *)(const char *)&Data)->Base.getVersion();
 998 }
 999
1000 bool APValue::isNullPointer() const {
1001   assert(isLValue() && "Invalid usage");
1002   return ((const LV *)(const char *)&Data)->IsNullPtr;
1003 }
1004
1005 void APValue::setLValue(LValueBase B, const CharUnits &O, NoLValuePath,
1006                         bool IsNullPtr) {
1007   assert(isLValue() && "Invalid accessor");
1008   LV &LVal = *((LV *)(char *)&Data);
1009   LVal.Base = B;
1010   LVal.IsOnePastTheEnd = false;
1011   LVal.Offset = O;
1012   LVal.resizePath((unsigned)-1);
1013   LVal.IsNullPtr = IsNullPtr;
1014 }
1015
1016 MutableArrayRef<APValue::LValuePathEntry>
1017 APValue::setLValueUninit(LValueBase B, const CharUnits &O, unsigned Size,
1018                          bool IsOnePastTheEnd, bool IsNullPtr) {
1019   assert(isLValue() && "Invalid accessor");
1020   LV &LVal = *((LV *)(char *)&Data);
1021   LVal.Base = B;
1022   LVal.IsOnePastTheEnd = IsOnePastTheEnd;
1023   LVal.Offset = O;
1024   LVal.IsNullPtr = IsNullPtr;
1025   LVal.resizePath(Size);
1026   return {LVal.getPath(), Size};
1027 }
1028
1029 void APValue::setLValue(LValueBase B, const CharUnits &O,
1030                         ArrayRef<LValuePathEntry> Path, bool IsOnePastTheEnd,
1031                         bool IsNullPtr) {
1032   MutableArrayRef<APValue::LValuePathEntry> InternalPath =
1033       setLValueUninit(B, O, Path.size(), IsOnePastTheEnd, IsNullPtr);
1034   if (Path.size()) {
1035     memcpy(InternalPath.data(), Path.data(),
1036            Path.size() * sizeof(LValuePathEntry));
1037   }
1038 }
1039
1040 void APValue::setUnion(const FieldDecl *Field, const APValue &Value) {
1041   assert(isUnion() && "Invalid accessor");
1042   ((UnionData *)(char *)&Data)->Field =
1043       Field ? Field->getCanonicalDecl() : nullptr;
1044   *((UnionData *)(char *)&Data)->Value = Value;
1045 }
1046
1047 const ValueDecl *APValue::getMemberPointerDecl() const {
1048   assert(isMemberPointer() && "Invalid accessor");
1049   const MemberPointerData &MPD =
1050       *((const MemberPointerData *)(const char *)&Data);
1051   return MPD.MemberAndIsDerivedMember.getPointer();
1052 }
1053
1054 bool APValue::isMemberPointerToDerivedMember() const {
1055   assert(isMemberPointer() && "Invalid accessor");
1056   const MemberPointerData &MPD =
1057       *((const MemberPointerData *)(const char *)&Data);
1058   return MPD.MemberAndIsDerivedMember.getInt();
1059 }
1060
1061 ArrayRef<const CXXRecordDecl*> APValue::getMemberPointerPath() const {
1062   assert(isMemberPointer() && "Invalid accessor");
1063   const MemberPointerData &MPD =
1064       *((const MemberPointerData *)(const char *)&Data);
1065   return llvm::makeArrayRef(MPD.getPath(), MPD.PathLength);
1066 }
1067
1068 void APValue::MakeLValue() {
1069   assert(isAbsent() && "Bad state change");
1070   static_assert(sizeof(LV) <= DataSize, "LV too big");
1071   new ((void *)(char *)&Data) LV();
1072   Kind = LValue;
1073 }
1074
1075 void APValue::MakeArray(unsigned InitElts, unsigned Size) {
1076   assert(isAbsent() && "Bad state change");
1077   new ((void *)(char *)&Data) Arr(InitElts, Size);
1078   Kind = Array;
1079 }
1080
1081 MutableArrayRef<APValue::LValuePathEntry>
1082 setLValueUninit(APValue::LValueBase B, const CharUnits &O, unsigned Size,
1083                 bool OnePastTheEnd, bool IsNullPtr);
1084
1085 MutableArrayRef<const CXXRecordDecl *>
1086 APValue::setMemberPointerUninit(const ValueDecl *Member, bool IsDerivedMember,
1087                                 unsigned Size) {
1088   assert(isAbsent() && "Bad state change");
1089   MemberPointerData *MPD = new ((void *)(char *)&Data) MemberPointerData;
1090   Kind = MemberPointer;
1091   MPD->MemberAndIsDerivedMember.setPointer(
1092       Member ? cast<ValueDecl>(Member->getCanonicalDecl()) : nullptr);
1093   MPD->MemberAndIsDerivedMember.setInt(IsDerivedMember);
1094   MPD->resizePath(Size);
1095   return {MPD->getPath(), MPD->PathLength};
1096 }
1097
1098 void APValue::MakeMemberPointer(const ValueDecl *Member, bool IsDerivedMember,
1099                                 ArrayRef<const CXXRecordDecl *> Path) {
1100   MutableArrayRef<const CXXRecordDecl *> InternalPath =
1101       setMemberPointerUninit(Member, IsDerivedMember, Path.size());
1102   for (unsigned I = 0; I != Path.size(); ++I)
1103     InternalPath[I] = Path[I]->getCanonicalDecl();
1104 }
1105
1106 LinkageInfo LinkageComputer::getLVForValue(const APValue &V,
1107                                            LVComputationKind computation) {
1108   LinkageInfo LV = LinkageInfo::external();
1109
1110   auto MergeLV = [&](LinkageInfo MergeLV) {
1111     LV.merge(MergeLV);
1112     return LV.getLinkage() == InternalLinkage;
1113   };
1114   auto Merge = [&](const APValue &V) {
1115     return MergeLV(getLVForValue(V, computation));
1116   };
1117
1118   switch (V.getKind()) {
1119   case APValue::None:
1120   case APValue::Indeterminate:
1121   case APValue::Int:
1122   case APValue::Float:
1123   case APValue::FixedPoint:
1124   case APValue::ComplexInt:
1125   case APValue::ComplexFloat:
1126   case APValue::Vector:
1127     break;
1128
1129   case APValue::AddrLabelDiff:
1130     // Even for an inline function, it's not reasonable to treat a difference
1131     // between the addresses of labels as an external value.
1132     return LinkageInfo::internal();
1133
1134   case APValue::Struct: {
1135     for (unsigned I = 0, N = V.getStructNumBases(); I != N; ++I)
1136       if (Merge(V.getStructBase(I)))
1137         break;
1138     for (unsigned I = 0, N = V.getStructNumFields(); I != N; ++I)
1139       if (Merge(V.getStructField(I)))
1140         break;
1141     break;
1142   }
1143
1144   case APValue::Union:
1145     if (V.getUnionField())
1146       Merge(V.getUnionValue());
1147     break;
1148
1149   case APValue::Array: {
1150     for (unsigned I = 0, N = V.getArrayInitializedElts(); I != N; ++I)
1151       if (Merge(V.getArrayInitializedElt(I)))
1152         break;
1153     if (V.hasArrayFiller())
1154       Merge(V.getArrayFiller());
1155     break;
1156   }
1157
1158   case APValue::LValue: {
1159     if (!V.getLValueBase()) {
1160       // Null or absolute address: this is external.
1161     } else if (const auto *VD =
1162                    V.getLValueBase().dyn_cast<const ValueDecl *>()) {
1163       if (VD && MergeLV(getLVForDecl(VD, computation)))
1164         break;
1165     } else if (const auto TI = V.getLValueBase().dyn_cast<TypeInfoLValue>()) {
1166       if (MergeLV(getLVForType(*TI.getType(), computation)))
1167         break;
1168     } else if (const Expr *E = V.getLValueBase().dyn_cast<const Expr *>()) {
1169       // Almost all expression bases are internal. The exception is
1170       // lifetime-extended temporaries.
1171       // FIXME: These should be modeled as having the
1172       // LifetimeExtendedTemporaryDecl itself as the base.
1173       // FIXME: If we permit Objective-C object literals in template arguments,
1174       // they should not imply internal linkage.
1175       auto *MTE = dyn_cast<MaterializeTemporaryExpr>(E);
1176       if (!MTE || MTE->getStorageDuration() == SD_FullExpression)
1177         return LinkageInfo::internal();
1178       if (MergeLV(getLVForDecl(MTE->getExtendingDecl(), computation)))
1179         break;
1180     } else {
1181       assert(V.getLValueBase().is<DynamicAllocLValue>() &&
1182              "unexpected LValueBase kind");
1183       return LinkageInfo::internal();
1184     }
1185     // The lvalue path doesn't matter: pointers to all subobjects always have
1186     // the same visibility as pointers to the complete object.
1187     break;
1188   }
1189
1190   case APValue::MemberPointer:
1191     if (const NamedDecl *D = V.getMemberPointerDecl())
1192       MergeLV(getLVForDecl(D, computation));
1193     // Note that we could have a base-to-derived conversion here to a member of
1194     // a derived class with less linkage/visibility. That's covered by the
1195     // linkage and visibility of the value's type.
1196     break;
1197   }
1198
1199   return LV;
1200 }