lib/IR/DebugInfoMetadata.cpp

   1 //===- DebugInfoMetadata.cpp - Implement debug info metadata --------------===//
   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 debug info Metadata classes.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "llvm/IR/DebugInfoMetadata.h"
  15 #include "LLVMContextImpl.h"
  16 #include "MetadataImpl.h"
  17 #include "llvm/ADT/StringSwitch.h"
  18 #include "llvm/IR/Function.h"
  19
  20 using namespace llvm;
  21
  22 DILocation::DILocation(LLVMContext &C, StorageType Storage, unsigned Line,
  23                        unsigned Column, ArrayRef<Metadata *> MDs)
  24     : MDNode(C, DILocationKind, Storage, MDs) {
  25   assert((MDs.size() == 1 || MDs.size() == 2) &&
  26          "Expected a scope and optional inlined-at");
  27
  28   // Set line and column.
  29   assert(Column < (1u << 16) && "Expected 16-bit column");
  30
  31   SubclassData32 = Line;
  32   SubclassData16 = Column;
  33 }
  34
  35 static void adjustColumn(unsigned &Column) {
  36   // Set to unknown on overflow.  We only have 16 bits to play with here.
  37   if (Column >= (1u << 16))
  38     Column = 0;
  39 }
  40
  41 DILocation *DILocation::getImpl(LLVMContext &Context, unsigned Line,
  42                                 unsigned Column, Metadata *Scope,
  43                                 Metadata *InlinedAt, StorageType Storage,
  44                                 bool ShouldCreate) {
  45   // Fixup column.
  46   adjustColumn(Column);
  47
  48   assert(Scope && "Expected scope");
  49   if (Storage == Uniqued) {
  50     if (auto *N =
  51             getUniqued(Context.pImpl->DILocations,
  52                        DILocationInfo::KeyTy(Line, Column, Scope, InlinedAt)))
  53       return N;
  54     if (!ShouldCreate)
  55       return nullptr;
  56   } else {
  57     assert(ShouldCreate && "Expected non-uniqued nodes to always be created");
  58   }
  59
  60   SmallVector<Metadata *, 2> Ops;
  61   Ops.push_back(Scope);
  62   if (InlinedAt)
  63     Ops.push_back(InlinedAt);
  64   return storeImpl(new (Ops.size())
  65                        DILocation(Context, Storage, Line, Column, Ops),
  66                    Storage, Context.pImpl->DILocations);
  67 }
  68
  69 unsigned DILocation::computeNewDiscriminator() const {
  70   // FIXME: This seems completely wrong.
  71   //
  72   //  1. If two modules are generated in the same context, then the second
  73   //     Module will get different discriminators than it would have if it were
  74   //     generated in its own context.
  75   //  2. If this function is called after round-tripping to bitcode instead of
  76   //     before, it will give a different (and potentially incorrect!) return.
  77   //
  78   // The discriminator should instead be calculated from local information
  79   // where it's actually needed.  This logic should be moved to
  80   // AddDiscriminators::runOnFunction(), where it doesn't pollute the
  81   // LLVMContext.
  82   std::pair<const char *, unsigned> Key(getFilename().data(), getLine());
  83   return ++getContext().pImpl->DiscriminatorTable[Key];
  84 }
  85
  86 unsigned DINode::getFlag(StringRef Flag) {
  87   return StringSwitch<unsigned>(Flag)
  88 #define HANDLE_DI_FLAG(ID, NAME) .Case("DIFlag" #NAME, Flag##NAME)
  89 #include "llvm/IR/DebugInfoFlags.def"
  90       .Default(0);
  91 }
  92
  93 const char *DINode::getFlagString(unsigned Flag) {
  94   switch (Flag) {
  95   default:
  96     return "";
  97 #define HANDLE_DI_FLAG(ID, NAME)                                               \
  98   case Flag##NAME:                                                             \
  99     return "DIFlag" #NAME;
 100 #include "llvm/IR/DebugInfoFlags.def"
 101   }
 102 }
 103
 104 unsigned DINode::splitFlags(unsigned Flags,
 105                             SmallVectorImpl<unsigned> &SplitFlags) {
 106   // Accessibility flags need to be specially handled, since they're packed
 107   // together.
 108   if (unsigned A = Flags & FlagAccessibility) {
 109     if (A == FlagPrivate)
 110       SplitFlags.push_back(FlagPrivate);
 111     else if (A == FlagProtected)
 112       SplitFlags.push_back(FlagProtected);
 113     else
 114       SplitFlags.push_back(FlagPublic);
 115     Flags &= ~A;
 116   }
 117
 118 #define HANDLE_DI_FLAG(ID, NAME)                                               \
 119   if (unsigned Bit = Flags & ID) {                                             \
 120     SplitFlags.push_back(Bit);                                                 \
 121     Flags &= ~Bit;                                                             \
 122   }
 123 #include "llvm/IR/DebugInfoFlags.def"
 124
 125   return Flags;
 126 }
 127
 128 DIScopeRef DIScope::getScope() const {
 129   if (auto *T = dyn_cast<DIType>(this))
 130     return T->getScope();
 131
 132   if (auto *SP = dyn_cast<DISubprogram>(this))
 133     return SP->getScope();
 134
 135   if (auto *LB = dyn_cast<DILexicalBlockBase>(this))
 136     return DIScopeRef(LB->getScope());
 137
 138   if (auto *NS = dyn_cast<DINamespace>(this))
 139     return DIScopeRef(NS->getScope());
 140
 141   assert((isa<DIFile>(this) || isa<DICompileUnit>(this)) &&
 142          "Unhandled type of scope.");
 143   return nullptr;
 144 }
 145
 146 StringRef DIScope::getName() const {
 147   if (auto *T = dyn_cast<DIType>(this))
 148     return T->getName();
 149   if (auto *SP = dyn_cast<DISubprogram>(this))
 150     return SP->getName();
 151   if (auto *NS = dyn_cast<DINamespace>(this))
 152     return NS->getName();
 153   assert((isa<DILexicalBlockBase>(this) || isa<DIFile>(this) ||
 154           isa<DICompileUnit>(this)) &&
 155          "Unhandled type of scope.");
 156   return "";
 157 }
 158
 159 static StringRef getString(const MDString *S) {
 160   if (S)
 161     return S->getString();
 162   return StringRef();
 163 }
 164
 165 #ifndef NDEBUG
 166 static bool isCanonical(const MDString *S) {
 167   return !S || !S->getString().empty();
 168 }
 169 #endif
 170
 171 GenericDINode *GenericDINode::getImpl(LLVMContext &Context, unsigned Tag,
 172                                       MDString *Header,
 173                                       ArrayRef<Metadata *> DwarfOps,
 174                                       StorageType Storage, bool ShouldCreate) {
 175   unsigned Hash = 0;
 176   if (Storage == Uniqued) {
 177     GenericDINodeInfo::KeyTy Key(Tag, getString(Header), DwarfOps);
 178     if (auto *N = getUniqued(Context.pImpl->GenericDINodes, Key))
 179       return N;
 180     if (!ShouldCreate)
 181       return nullptr;
 182     Hash = Key.getHash();
 183   } else {
 184     assert(ShouldCreate && "Expected non-uniqued nodes to always be created");
 185   }
 186
 187   // Use a nullptr for empty headers.
 188   assert(isCanonical(Header) && "Expected canonical MDString");
 189   Metadata *PreOps[] = {Header};
 190   return storeImpl(new (DwarfOps.size() + 1) GenericDINode(
 191                        Context, Storage, Hash, Tag, PreOps, DwarfOps),
 192                    Storage, Context.pImpl->GenericDINodes);
 193 }
 194
 195 void GenericDINode::recalculateHash() {
 196   setHash(GenericDINodeInfo::KeyTy::calculateHash(this));
 197 }
 198
 199 #define UNWRAP_ARGS_IMPL(...) __VA_ARGS__
 200 #define UNWRAP_ARGS(ARGS) UNWRAP_ARGS_IMPL ARGS
 201 #define DEFINE_GETIMPL_LOOKUP(CLASS, ARGS)                                     \
 202   do {                                                                         \
 203     if (Storage == Uniqued) {                                                  \
 204       if (auto *N = getUniqued(Context.pImpl->CLASS##s,                        \
 205                                CLASS##Info::KeyTy(UNWRAP_ARGS(ARGS))))         \
 206         return N;                                                              \
 207       if (!ShouldCreate)                                                       \
 208         return nullptr;                                                        \
 209     } else {                                                                   \
 210       assert(ShouldCreate &&                                                   \
 211              "Expected non-uniqued nodes to always be created");               \
 212     }                                                                          \
 213   } while (false)
 214 #define DEFINE_GETIMPL_STORE(CLASS, ARGS, OPS)                                 \
 215   return storeImpl(new (ArrayRef<Metadata *>(OPS).size())                      \
 216                        CLASS(Context, Storage, UNWRAP_ARGS(ARGS), OPS),        \
 217                    Storage, Context.pImpl->CLASS##s)
 218 #define DEFINE_GETIMPL_STORE_NO_OPS(CLASS, ARGS)                               \
 219   return storeImpl(new (0u) CLASS(Context, Storage, UNWRAP_ARGS(ARGS)),        \
 220                    Storage, Context.pImpl->CLASS##s)
 221 #define DEFINE_GETIMPL_STORE_NO_CONSTRUCTOR_ARGS(CLASS, OPS)                   \
 222   return storeImpl(new (ArrayRef<Metadata *>(OPS).size())                      \
 223                        CLASS(Context, Storage, OPS),                           \
 224                    Storage, Context.pImpl->CLASS##s)
 225
 226 DISubrange *DISubrange::getImpl(LLVMContext &Context, int64_t Count, int64_t Lo,
 227                                 StorageType Storage, bool ShouldCreate) {
 228   DEFINE_GETIMPL_LOOKUP(DISubrange, (Count, Lo));
 229   DEFINE_GETIMPL_STORE_NO_OPS(DISubrange, (Count, Lo));
 230 }
 231
 232 DIEnumerator *DIEnumerator::getImpl(LLVMContext &Context, int64_t Value,
 233                                     MDString *Name, StorageType Storage,
 234                                     bool ShouldCreate) {
 235   assert(isCanonical(Name) && "Expected canonical MDString");
 236   DEFINE_GETIMPL_LOOKUP(DIEnumerator, (Value, getString(Name)));
 237   Metadata *Ops[] = {Name};
 238   DEFINE_GETIMPL_STORE(DIEnumerator, (Value), Ops);
 239 }
 240
 241 DIBasicType *DIBasicType::getImpl(LLVMContext &Context, unsigned Tag,
 242                                   MDString *Name, uint64_t SizeInBits,
 243                                   uint64_t AlignInBits, unsigned Encoding,
 244                                   StorageType Storage, bool ShouldCreate) {
 245   assert(isCanonical(Name) && "Expected canonical MDString");
 246   DEFINE_GETIMPL_LOOKUP(
 247       DIBasicType, (Tag, getString(Name), SizeInBits, AlignInBits, Encoding));
 248   Metadata *Ops[] = {nullptr, nullptr, Name};
 249   DEFINE_GETIMPL_STORE(DIBasicType, (Tag, SizeInBits, AlignInBits, Encoding),
 250                        Ops);
 251 }
 252
 253 DIDerivedType *DIDerivedType::getImpl(
 254     LLVMContext &Context, unsigned Tag, MDString *Name, Metadata *File,
 255     unsigned Line, Metadata *Scope, Metadata *BaseType, uint64_t SizeInBits,
 256     uint64_t AlignInBits, uint64_t OffsetInBits, unsigned Flags,
 257     Metadata *ExtraData, StorageType Storage, bool ShouldCreate) {
 258   assert(isCanonical(Name) && "Expected canonical MDString");
 259   DEFINE_GETIMPL_LOOKUP(DIDerivedType, (Tag, getString(Name), File, Line, Scope,
 260                                         BaseType, SizeInBits, AlignInBits,
 261                                         OffsetInBits, Flags, ExtraData));
 262   Metadata *Ops[] = {File, Scope, Name, BaseType, ExtraData};
 263   DEFINE_GETIMPL_STORE(
 264       DIDerivedType, (Tag, Line, SizeInBits, AlignInBits, OffsetInBits, Flags),
 265       Ops);
 266 }
 267
 268 DICompositeType *DICompositeType::getImpl(
 269     LLVMContext &Context, unsigned Tag, MDString *Name, Metadata *File,
 270     unsigned Line, Metadata *Scope, Metadata *BaseType, uint64_t SizeInBits,
 271     uint64_t AlignInBits, uint64_t OffsetInBits, unsigned Flags,
 272     Metadata *Elements, unsigned RuntimeLang, Metadata *VTableHolder,
 273     Metadata *TemplateParams, MDString *Identifier, StorageType Storage,
 274     bool ShouldCreate) {
 275   assert(isCanonical(Name) && "Expected canonical MDString");
 276   DEFINE_GETIMPL_LOOKUP(DICompositeType,
 277                         (Tag, getString(Name), File, Line, Scope, BaseType,
 278                          SizeInBits, AlignInBits, OffsetInBits, Flags, Elements,
 279                          RuntimeLang, VTableHolder, TemplateParams,
 280                          getString(Identifier)));
 281   Metadata *Ops[] = {File,     Scope,        Name,           BaseType,
 282                      Elements, VTableHolder, TemplateParams, Identifier};
 283   DEFINE_GETIMPL_STORE(DICompositeType, (Tag, Line, RuntimeLang, SizeInBits,
 284                                          AlignInBits, OffsetInBits, Flags),
 285                        Ops);
 286 }
 287
 288 DISubroutineType *DISubroutineType::getImpl(LLVMContext &Context,
 289                                             unsigned Flags, Metadata *TypeArray,
 290                                             StorageType Storage,
 291                                             bool ShouldCreate) {
 292   DEFINE_GETIMPL_LOOKUP(DISubroutineType, (Flags, TypeArray));
 293   Metadata *Ops[] = {nullptr,   nullptr, nullptr, nullptr,
 294                      TypeArray, nullptr, nullptr, nullptr};
 295   DEFINE_GETIMPL_STORE(DISubroutineType, (Flags), Ops);
 296 }
 297
 298 DIFile *DIFile::getImpl(LLVMContext &Context, MDString *Filename,
 299                         MDString *Directory, StorageType Storage,
 300                         bool ShouldCreate) {
 301   assert(isCanonical(Filename) && "Expected canonical MDString");
 302   assert(isCanonical(Directory) && "Expected canonical MDString");
 303   DEFINE_GETIMPL_LOOKUP(DIFile, (getString(Filename), getString(Directory)));
 304   Metadata *Ops[] = {Filename, Directory};
 305   DEFINE_GETIMPL_STORE_NO_CONSTRUCTOR_ARGS(DIFile, Ops);
 306 }
 307
 308 DICompileUnit *DICompileUnit::getImpl(
 309     LLVMContext &Context, unsigned SourceLanguage, Metadata *File,
 310     MDString *Producer, bool IsOptimized, MDString *Flags,
 311     unsigned RuntimeVersion, MDString *SplitDebugFilename,
 312     unsigned EmissionKind, Metadata *EnumTypes, Metadata *RetainedTypes,
 313     Metadata *Subprograms, Metadata *GlobalVariables,
 314     Metadata *ImportedEntities, uint64_t DWOId,
 315     StorageType Storage, bool ShouldCreate) {
 316   assert(isCanonical(Producer) && "Expected canonical MDString");
 317   assert(isCanonical(Flags) && "Expected canonical MDString");
 318   assert(isCanonical(SplitDebugFilename) && "Expected canonical MDString");
 319   DEFINE_GETIMPL_LOOKUP(
 320       DICompileUnit,
 321       (SourceLanguage, File, getString(Producer), IsOptimized, getString(Flags),
 322        RuntimeVersion, getString(SplitDebugFilename), EmissionKind, EnumTypes,
 323        RetainedTypes, Subprograms, GlobalVariables, ImportedEntities, DWOId));
 324   Metadata *Ops[] = {File, Producer, Flags, SplitDebugFilename, EnumTypes,
 325                      RetainedTypes, Subprograms, GlobalVariables,
 326                      ImportedEntities};
 327   DEFINE_GETIMPL_STORE(
 328       DICompileUnit,
 329       (SourceLanguage, IsOptimized, RuntimeVersion, EmissionKind, DWOId), Ops);
 330 }
 331
 332 DISubprogram *DILocalScope::getSubprogram() const {
 333   if (auto *Block = dyn_cast<DILexicalBlockBase>(this))
 334     return Block->getScope()->getSubprogram();
 335   return const_cast<DISubprogram *>(cast<DISubprogram>(this));
 336 }
 337
 338 DISubprogram *DISubprogram::getImpl(
 339     LLVMContext &Context, Metadata *Scope, MDString *Name,
 340     MDString *LinkageName, Metadata *File, unsigned Line, Metadata *Type,
 341     bool IsLocalToUnit, bool IsDefinition, unsigned ScopeLine,
 342     Metadata *ContainingType, unsigned Virtuality, unsigned VirtualIndex,
 343     unsigned Flags, bool IsOptimized, Metadata *Function,
 344     Metadata *TemplateParams, Metadata *Declaration, Metadata *Variables,
 345     StorageType Storage, bool ShouldCreate) {
 346   assert(isCanonical(Name) && "Expected canonical MDString");
 347   assert(isCanonical(LinkageName) && "Expected canonical MDString");
 348   DEFINE_GETIMPL_LOOKUP(DISubprogram,
 349                         (Scope, getString(Name), getString(LinkageName), File,
 350                          Line, Type, IsLocalToUnit, IsDefinition, ScopeLine,
 351                          ContainingType, Virtuality, VirtualIndex, Flags,
 352                          IsOptimized, Function, TemplateParams, Declaration,
 353                          Variables));
 354   Metadata *Ops[] = {File,           Scope,       Name,           Name,
 355                      LinkageName,    Type,        ContainingType, Function,
 356                      TemplateParams, Declaration, Variables};
 357   DEFINE_GETIMPL_STORE(DISubprogram,
 358                        (Line, ScopeLine, Virtuality, VirtualIndex, Flags,
 359                         IsLocalToUnit, IsDefinition, IsOptimized),
 360                        Ops);
 361 }
 362
 363 Function *DISubprogram::getFunction() const {
 364   // FIXME: Should this be looking through bitcasts?
 365   return dyn_cast_or_null<Function>(getFunctionConstant());
 366 }
 367
 368 bool DISubprogram::describes(const Function *F) const {
 369   assert(F && "Invalid function");
 370   if (F == getFunction())
 371     return true;
 372   StringRef Name = getLinkageName();
 373   if (Name.empty())
 374     Name = getName();
 375   return F->getName() == Name;
 376 }
 377
 378 void DISubprogram::replaceFunction(Function *F) {
 379   replaceFunction(F ? ConstantAsMetadata::get(F)
 380                     : static_cast<ConstantAsMetadata *>(nullptr));
 381 }
 382
 383 DILexicalBlock *DILexicalBlock::getImpl(LLVMContext &Context, Metadata *Scope,
 384                                         Metadata *File, unsigned Line,
 385                                         unsigned Column, StorageType Storage,
 386                                         bool ShouldCreate) {
 387   assert(Scope && "Expected scope");
 388   DEFINE_GETIMPL_LOOKUP(DILexicalBlock, (Scope, File, Line, Column));
 389   Metadata *Ops[] = {File, Scope};
 390   DEFINE_GETIMPL_STORE(DILexicalBlock, (Line, Column), Ops);
 391 }
 392
 393 DILexicalBlockFile *DILexicalBlockFile::getImpl(LLVMContext &Context,
 394                                                 Metadata *Scope, Metadata *File,
 395                                                 unsigned Discriminator,
 396                                                 StorageType Storage,
 397                                                 bool ShouldCreate) {
 398   assert(Scope && "Expected scope");
 399   DEFINE_GETIMPL_LOOKUP(DILexicalBlockFile, (Scope, File, Discriminator));
 400   Metadata *Ops[] = {File, Scope};
 401   DEFINE_GETIMPL_STORE(DILexicalBlockFile, (Discriminator), Ops);
 402 }
 403
 404 DINamespace *DINamespace::getImpl(LLVMContext &Context, Metadata *Scope,
 405                                   Metadata *File, MDString *Name, unsigned Line,
 406                                   StorageType Storage, bool ShouldCreate) {
 407   assert(isCanonical(Name) && "Expected canonical MDString");
 408   DEFINE_GETIMPL_LOOKUP(DINamespace, (Scope, File, getString(Name), Line));
 409   Metadata *Ops[] = {File, Scope, Name};
 410   DEFINE_GETIMPL_STORE(DINamespace, (Line), Ops);
 411 }
 412
 413 DITemplateTypeParameter *DITemplateTypeParameter::getImpl(LLVMContext &Context,
 414                                                           MDString *Name,
 415                                                           Metadata *Type,
 416                                                           StorageType Storage,
 417                                                           bool ShouldCreate) {
 418   assert(isCanonical(Name) && "Expected canonical MDString");
 419   DEFINE_GETIMPL_LOOKUP(DITemplateTypeParameter, (getString(Name), Type));
 420   Metadata *Ops[] = {Name, Type};
 421   DEFINE_GETIMPL_STORE_NO_CONSTRUCTOR_ARGS(DITemplateTypeParameter, Ops);
 422 }
 423
 424 DITemplateValueParameter *DITemplateValueParameter::getImpl(
 425     LLVMContext &Context, unsigned Tag, MDString *Name, Metadata *Type,
 426     Metadata *Value, StorageType Storage, bool ShouldCreate) {
 427   assert(isCanonical(Name) && "Expected canonical MDString");
 428   DEFINE_GETIMPL_LOOKUP(DITemplateValueParameter,
 429                         (Tag, getString(Name), Type, Value));
 430   Metadata *Ops[] = {Name, Type, Value};
 431   DEFINE_GETIMPL_STORE(DITemplateValueParameter, (Tag), Ops);
 432 }
 433
 434 DIGlobalVariable *
 435 DIGlobalVariable::getImpl(LLVMContext &Context, Metadata *Scope, MDString *Name,
 436                           MDString *LinkageName, Metadata *File, unsigned Line,
 437                           Metadata *Type, bool IsLocalToUnit, bool IsDefinition,
 438                           Metadata *Variable,
 439                           Metadata *StaticDataMemberDeclaration,
 440                           StorageType Storage, bool ShouldCreate) {
 441   assert(isCanonical(Name) && "Expected canonical MDString");
 442   assert(isCanonical(LinkageName) && "Expected canonical MDString");
 443   DEFINE_GETIMPL_LOOKUP(DIGlobalVariable,
 444                         (Scope, getString(Name), getString(LinkageName), File,
 445                          Line, Type, IsLocalToUnit, IsDefinition, Variable,
 446                          StaticDataMemberDeclaration));
 447   Metadata *Ops[] = {Scope, Name,        File,     Type,
 448                      Name,  LinkageName, Variable, StaticDataMemberDeclaration};
 449   DEFINE_GETIMPL_STORE(DIGlobalVariable, (Line, IsLocalToUnit, IsDefinition),
 450                        Ops);
 451 }
 452
 453 DILocalVariable *DILocalVariable::getImpl(LLVMContext &Context, unsigned Tag,
 454                                           Metadata *Scope, MDString *Name,
 455                                           Metadata *File, unsigned Line,
 456                                           Metadata *Type, unsigned Arg,
 457                                           unsigned Flags, StorageType Storage,
 458                                           bool ShouldCreate) {
 459   // 64K ought to be enough for any frontend.
 460   assert(Arg <= UINT16_MAX && "Expected argument number to fit in 16-bits");
 461
 462   assert(Scope && "Expected scope");
 463   assert(isCanonical(Name) && "Expected canonical MDString");
 464   DEFINE_GETIMPL_LOOKUP(DILocalVariable, (Tag, Scope, getString(Name), File,
 465                                           Line, Type, Arg, Flags));
 466   Metadata *Ops[] = {Scope, Name, File, Type};
 467   DEFINE_GETIMPL_STORE(DILocalVariable, (Tag, Line, Arg, Flags), Ops);
 468 }
 469
 470 DIExpression *DIExpression::getImpl(LLVMContext &Context,
 471                                     ArrayRef<uint64_t> Elements,
 472                                     StorageType Storage, bool ShouldCreate) {
 473   DEFINE_GETIMPL_LOOKUP(DIExpression, (Elements));
 474   DEFINE_GETIMPL_STORE_NO_OPS(DIExpression, (Elements));
 475 }
 476
 477 unsigned DIExpression::ExprOperand::getSize() const {
 478   switch (getOp()) {
 479   case dwarf::DW_OP_bit_piece:
 480     return 3;
 481   case dwarf::DW_OP_plus:
 482     return 2;
 483   default:
 484     return 1;
 485   }
 486 }
 487
 488 bool DIExpression::isValid() const {
 489   for (auto I = expr_op_begin(), E = expr_op_end(); I != E; ++I) {
 490     // Check that there's space for the operand.
 491     if (I->get() + I->getSize() > E->get())
 492       return false;
 493
 494     // Check that the operand is valid.
 495     switch (I->getOp()) {
 496     default:
 497       return false;
 498     case dwarf::DW_OP_bit_piece:
 499       // Piece expressions must be at the end.
 500       return I->get() + I->getSize() == E->get();
 501     case dwarf::DW_OP_plus:
 502     case dwarf::DW_OP_deref:
 503       break;
 504     }
 505   }
 506   return true;
 507 }
 508
 509 bool DIExpression::isBitPiece() const {
 510   assert(isValid() && "Expected valid expression");
 511   if (unsigned N = getNumElements())
 512     if (N >= 3)
 513       return getElement(N - 3) == dwarf::DW_OP_bit_piece;
 514   return false;
 515 }
 516
 517 uint64_t DIExpression::getBitPieceOffset() const {
 518   assert(isBitPiece() && "Expected bit piece");
 519   return getElement(getNumElements() - 2);
 520 }
 521
 522 uint64_t DIExpression::getBitPieceSize() const {
 523   assert(isBitPiece() && "Expected bit piece");
 524   return getElement(getNumElements() - 1);
 525 }
 526
 527 DIObjCProperty *DIObjCProperty::getImpl(
 528     LLVMContext &Context, MDString *Name, Metadata *File, unsigned Line,
 529     MDString *GetterName, MDString *SetterName, unsigned Attributes,
 530     Metadata *Type, StorageType Storage, bool ShouldCreate) {
 531   assert(isCanonical(Name) && "Expected canonical MDString");
 532   assert(isCanonical(GetterName) && "Expected canonical MDString");
 533   assert(isCanonical(SetterName) && "Expected canonical MDString");
 534   DEFINE_GETIMPL_LOOKUP(DIObjCProperty,
 535                         (getString(Name), File, Line, getString(GetterName),
 536                          getString(SetterName), Attributes, Type));
 537   Metadata *Ops[] = {Name, File, GetterName, SetterName, Type};
 538   DEFINE_GETIMPL_STORE(DIObjCProperty, (Line, Attributes), Ops);
 539 }
 540
 541 DIImportedEntity *DIImportedEntity::getImpl(LLVMContext &Context, unsigned Tag,
 542                                             Metadata *Scope, Metadata *Entity,
 543                                             unsigned Line, MDString *Name,
 544                                             StorageType Storage,
 545                                             bool ShouldCreate) {
 546   assert(isCanonical(Name) && "Expected canonical MDString");
 547   DEFINE_GETIMPL_LOOKUP(DIImportedEntity,
 548                         (Tag, Scope, Entity, Line, getString(Name)));
 549   Metadata *Ops[] = {Scope, Entity, Name};
 550   DEFINE_GETIMPL_STORE(DIImportedEntity, (Tag, Line), Ops);
 551 }