lib/IR/DIBuilder.cpp

   1 //===--- DIBuilder.cpp - Debug Information Builder ------------------------===//
   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 DIBuilder.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "llvm/IR/DIBuilder.h"
  15 #include "llvm/ADT/STLExtras.h"
  16 #include "llvm/IR/Constants.h"
  17 #include "llvm/IR/DebugInfo.h"
  18 #include "llvm/IR/IntrinsicInst.h"
  19 #include "llvm/IR/Module.h"
  20 #include "llvm/Support/Debug.h"
  21 #include "llvm/Support/Dwarf.h"
  22
  23 using namespace llvm;
  24 using namespace llvm::dwarf;
  25
  26 namespace {
  27 class HeaderBuilder {
  28   /// \brief Whether there are any fields yet.
  29   ///
  30   /// Note that this is not equivalent to \c Chars.empty(), since \a concat()
  31   /// may have been called already with an empty string.
  32   bool IsEmpty;
  33   SmallVector<char, 256> Chars;
  34
  35 public:
  36   HeaderBuilder() : IsEmpty(true) {}
  37   HeaderBuilder(const HeaderBuilder &X) : IsEmpty(X.IsEmpty), Chars(X.Chars) {}
  38   HeaderBuilder(HeaderBuilder &&X)
  39       : IsEmpty(X.IsEmpty), Chars(std::move(X.Chars)) {}
  40
  41   template <class Twineable> HeaderBuilder &concat(Twineable &&X) {
  42     if (IsEmpty)
  43       IsEmpty = false;
  44     else
  45       Chars.push_back(0);
  46     Twine(X).toVector(Chars);
  47     return *this;
  48   }
  49
  50   MDString *get(LLVMContext &Context) const {
  51     return MDString::get(Context, StringRef(Chars.begin(), Chars.size()));
  52   }
  53
  54   static HeaderBuilder get(unsigned Tag) {
  55     return HeaderBuilder().concat("0x" + Twine::utohexstr(Tag));
  56   }
  57 };
  58 }
  59
  60 DIBuilder::DIBuilder(Module &m, bool AllowUnresolvedNodes)
  61   : M(m), VMContext(M.getContext()), CUNode(nullptr),
  62       DeclareFn(nullptr), ValueFn(nullptr),
  63       AllowUnresolvedNodes(AllowUnresolvedNodes) {}
  64
  65 void DIBuilder::trackIfUnresolved(MDNode *N) {
  66   if (!N)
  67     return;
  68   if (N->isResolved())
  69     return;
  70
  71   assert(AllowUnresolvedNodes && "Cannot handle unresolved nodes");
  72   UnresolvedNodes.emplace_back(N);
  73 }
  74
  75 void DIBuilder::finalize() {
  76   if (!CUNode) {
  77     assert(!AllowUnresolvedNodes &&
  78            "creating type nodes without a CU is not supported");
  79     return;
  80   }
  81
  82   CUNode->replaceEnumTypes(MDTuple::get(VMContext, AllEnumTypes));
  83
  84   SmallVector<Metadata *, 16> RetainValues;
  85   // Declarations and definitions of the same type may be retained. Some
  86   // clients RAUW these pairs, leaving duplicates in the retained types
  87   // list. Use a set to remove the duplicates while we transform the
  88   // TrackingVHs back into Values.
  89   SmallPtrSet<Metadata *, 16> RetainSet;
  90   for (unsigned I = 0, E = AllRetainTypes.size(); I < E; I++)
  91     if (RetainSet.insert(AllRetainTypes[I]).second)
  92       RetainValues.push_back(AllRetainTypes[I]);
  93
  94   if (!RetainValues.empty())
  95     CUNode->replaceRetainedTypes(MDTuple::get(VMContext, RetainValues));
  96
  97   DISubprogramArray SPs = MDTuple::get(VMContext, AllSubprograms);
  98   if (!AllSubprograms.empty())
  99     CUNode->replaceSubprograms(SPs.get());
 100
 101   for (auto *SP : SPs) {
 102     if (MDTuple *Temp = SP->getVariables().get()) {
 103       const auto &PV = PreservedVariables.lookup(SP);
 104       SmallVector<Metadata *, 4> Variables(PV.begin(), PV.end());
 105       DINodeArray AV = getOrCreateArray(Variables);
 106       TempMDTuple(Temp)->replaceAllUsesWith(AV.get());
 107     }
 108   }
 109
 110   if (!AllGVs.empty())
 111     CUNode->replaceGlobalVariables(MDTuple::get(VMContext, AllGVs));
 112
 113   if (!AllImportedModules.empty())
 114     CUNode->replaceImportedEntities(MDTuple::get(
 115         VMContext, SmallVector<Metadata *, 16>(AllImportedModules.begin(),
 116                                                AllImportedModules.end())));
 117
 118   // Now that all temp nodes have been replaced or deleted, resolve remaining
 119   // cycles.
 120   for (const auto &N : UnresolvedNodes)
 121     if (N && !N->isResolved())
 122       N->resolveCycles();
 123   UnresolvedNodes.clear();
 124
 125   // Can't handle unresolved nodes anymore.
 126   AllowUnresolvedNodes = false;
 127 }
 128
 129 /// If N is compile unit return NULL otherwise return N.
 130 static DIScope *getNonCompileUnitScope(DIScope *N) {
 131   if (!N || isa<DICompileUnit>(N))
 132     return nullptr;
 133   return cast<DIScope>(N);
 134 }
 135
 136 DICompileUnit *DIBuilder::createCompileUnit(
 137     unsigned Lang, StringRef Filename, StringRef Directory, StringRef Producer,
 138     bool isOptimized, StringRef Flags, unsigned RunTimeVer, StringRef SplitName,
 139     DebugEmissionKind Kind, uint64_t DWOId, bool EmitDebugInfo) {
 140
 141   assert(((Lang <= dwarf::DW_LANG_Fortran08 && Lang >= dwarf::DW_LANG_C89) ||
 142           (Lang <= dwarf::DW_LANG_hi_user && Lang >= dwarf::DW_LANG_lo_user)) &&
 143          "Invalid Language tag");
 144   assert(!Filename.empty() &&
 145          "Unable to create compile unit without filename");
 146
 147   assert(!CUNode && "Can only make one compile unit per DIBuilder instance");
 148   CUNode = DICompileUnit::getDistinct(
 149       VMContext, Lang, DIFile::get(VMContext, Filename, Directory), Producer,
 150       isOptimized, Flags, RunTimeVer, SplitName, Kind, nullptr,
 151       nullptr, nullptr, nullptr, nullptr, nullptr, DWOId);
 152
 153   // Create a named metadata so that it is easier to find cu in a module.
 154   // Note that we only generate this when the caller wants to actually
 155   // emit debug information. When we are only interested in tracking
 156   // source line locations throughout the backend, we prevent codegen from
 157   // emitting debug info in the final output by not generating llvm.dbg.cu.
 158   if (EmitDebugInfo) {
 159     NamedMDNode *NMD = M.getOrInsertNamedMetadata("llvm.dbg.cu");
 160     NMD->addOperand(CUNode);
 161   }
 162
 163   trackIfUnresolved(CUNode);
 164   return CUNode;
 165 }
 166
 167 static DIImportedEntity *
 168 createImportedModule(LLVMContext &C, dwarf::Tag Tag, DIScope *Context,
 169                      Metadata *NS, unsigned Line, StringRef Name,
 170                      SmallVectorImpl<TrackingMDNodeRef> &AllImportedModules) {
 171   auto *M = DIImportedEntity::get(C, Tag, Context, DINodeRef(NS), Line, Name);
 172   AllImportedModules.emplace_back(M);
 173   return M;
 174 }
 175
 176 DIImportedEntity *DIBuilder::createImportedModule(DIScope *Context,
 177                                                   DINamespace *NS,
 178                                                   unsigned Line) {
 179   return ::createImportedModule(VMContext, dwarf::DW_TAG_imported_module,
 180                                 Context, NS, Line, StringRef(), AllImportedModules);
 181 }
 182
 183 DIImportedEntity *DIBuilder::createImportedModule(DIScope *Context,
 184                                                   DIImportedEntity *NS,
 185                                                   unsigned Line) {
 186   return ::createImportedModule(VMContext, dwarf::DW_TAG_imported_module,
 187                                 Context, NS, Line, StringRef(), AllImportedModules);
 188 }
 189
 190 DIImportedEntity *DIBuilder::createImportedModule(DIScope *Context, DIModule *M,
 191                                                   unsigned Line) {
 192   return ::createImportedModule(VMContext, dwarf::DW_TAG_imported_module,
 193                                 Context, M, Line, StringRef(), AllImportedModules);
 194 }
 195
 196 DIImportedEntity *DIBuilder::createImportedDeclaration(DIScope *Context,
 197                                                        DINode *Decl,
 198                                                        unsigned Line,
 199                                                        StringRef Name) {
 200   // Make sure to use the unique identifier based metadata reference for
 201   // types that have one.
 202   return ::createImportedModule(VMContext, dwarf::DW_TAG_imported_declaration,
 203                                 Context, DINodeRef::get(Decl), Line, Name,
 204                                 AllImportedModules);
 205 }
 206
 207 DIFile *DIBuilder::createFile(StringRef Filename, StringRef Directory) {
 208   return DIFile::get(VMContext, Filename, Directory);
 209 }
 210
 211 DIEnumerator *DIBuilder::createEnumerator(StringRef Name, int64_t Val) {
 212   assert(!Name.empty() && "Unable to create enumerator without name");
 213   return DIEnumerator::get(VMContext, Val, Name);
 214 }
 215
 216 DIBasicType *DIBuilder::createUnspecifiedType(StringRef Name) {
 217   assert(!Name.empty() && "Unable to create type without name");
 218   return DIBasicType::get(VMContext, dwarf::DW_TAG_unspecified_type, Name);
 219 }
 220
 221 DIBasicType *DIBuilder::createNullPtrType() {
 222   return createUnspecifiedType("decltype(nullptr)");
 223 }
 224
 225 DIBasicType *DIBuilder::createBasicType(StringRef Name, uint64_t SizeInBits,
 226                                         uint64_t AlignInBits,
 227                                         unsigned Encoding) {
 228   assert(!Name.empty() && "Unable to create type without name");
 229   return DIBasicType::get(VMContext, dwarf::DW_TAG_base_type, Name, SizeInBits,
 230                           AlignInBits, Encoding);
 231 }
 232
 233 DIDerivedType *DIBuilder::createQualifiedType(unsigned Tag, DIType *FromTy) {
 234   return DIDerivedType::get(VMContext, Tag, "", nullptr, 0, nullptr,
 235                             DITypeRef::get(FromTy), 0, 0, 0, 0);
 236 }
 237
 238 DIDerivedType *DIBuilder::createPointerType(DIType *PointeeTy,
 239                                             uint64_t SizeInBits,
 240                                             uint64_t AlignInBits,
 241                                             StringRef Name) {
 242   // FIXME: Why is there a name here?
 243   return DIDerivedType::get(VMContext, dwarf::DW_TAG_pointer_type, Name,
 244                             nullptr, 0, nullptr, DITypeRef::get(PointeeTy),
 245                             SizeInBits, AlignInBits, 0, 0);
 246 }
 247
 248 DIDerivedType *DIBuilder::createMemberPointerType(DIType *PointeeTy,
 249                                                   DIType *Base,
 250                                                   uint64_t SizeInBits,
 251                                                   uint64_t AlignInBits) {
 252   return DIDerivedType::get(VMContext, dwarf::DW_TAG_ptr_to_member_type, "",
 253                             nullptr, 0, nullptr, DITypeRef::get(PointeeTy),
 254                             SizeInBits, AlignInBits, 0, 0,
 255                             DITypeRef::get(Base));
 256 }
 257
 258 DIDerivedType *DIBuilder::createReferenceType(unsigned Tag, DIType *RTy,
 259                                               uint64_t SizeInBits,
 260                                               uint64_t AlignInBits) {
 261   assert(RTy && "Unable to create reference type");
 262   return DIDerivedType::get(VMContext, Tag, "", nullptr, 0, nullptr,
 263                             DITypeRef::get(RTy), SizeInBits, AlignInBits, 0, 0);
 264 }
 265
 266 DIDerivedType *DIBuilder::createTypedef(DIType *Ty, StringRef Name,
 267                                         DIFile *File, unsigned LineNo,
 268                                         DIScope *Context) {
 269   return DIDerivedType::get(VMContext, dwarf::DW_TAG_typedef, Name, File,
 270                             LineNo,
 271                             DIScopeRef::get(getNonCompileUnitScope(Context)),
 272                             DITypeRef::get(Ty), 0, 0, 0, 0);
 273 }
 274
 275 DIDerivedType *DIBuilder::createFriend(DIType *Ty, DIType *FriendTy) {
 276   assert(Ty && "Invalid type!");
 277   assert(FriendTy && "Invalid friend type!");
 278   return DIDerivedType::get(VMContext, dwarf::DW_TAG_friend, "", nullptr, 0,
 279                             DITypeRef::get(Ty), DITypeRef::get(FriendTy), 0, 0,
 280                             0, 0);
 281 }
 282
 283 DIDerivedType *DIBuilder::createInheritance(DIType *Ty, DIType *BaseTy,
 284                                             uint64_t BaseOffset,
 285                                             unsigned Flags) {
 286   assert(Ty && "Unable to create inheritance");
 287   return DIDerivedType::get(VMContext, dwarf::DW_TAG_inheritance, "", nullptr,
 288                             0, DITypeRef::get(Ty), DITypeRef::get(BaseTy), 0, 0,
 289                             BaseOffset, Flags);
 290 }
 291
 292 DIDerivedType *DIBuilder::createMemberType(DIScope *Scope, StringRef Name,
 293                                            DIFile *File, unsigned LineNumber,
 294                                            uint64_t SizeInBits,
 295                                            uint64_t AlignInBits,
 296                                            uint64_t OffsetInBits,
 297                                            unsigned Flags, DIType *Ty) {
 298   return DIDerivedType::get(
 299       VMContext, dwarf::DW_TAG_member, Name, File, LineNumber,
 300       DIScopeRef::get(getNonCompileUnitScope(Scope)), DITypeRef::get(Ty),
 301       SizeInBits, AlignInBits, OffsetInBits, Flags);
 302 }
 303
 304 static ConstantAsMetadata *getConstantOrNull(Constant *C) {
 305   if (C)
 306     return ConstantAsMetadata::get(C);
 307   return nullptr;
 308 }
 309
 310 DIDerivedType *DIBuilder::createStaticMemberType(DIScope *Scope, StringRef Name,
 311                                                  DIFile *File,
 312                                                  unsigned LineNumber,
 313                                                  DIType *Ty, unsigned Flags,
 314                                                  llvm::Constant *Val) {
 315   Flags |= DINode::FlagStaticMember;
 316   return DIDerivedType::get(
 317       VMContext, dwarf::DW_TAG_member, Name, File, LineNumber,
 318       DIScopeRef::get(getNonCompileUnitScope(Scope)), DITypeRef::get(Ty), 0, 0,
 319       0, Flags, getConstantOrNull(Val));
 320 }
 321
 322 DIDerivedType *DIBuilder::createObjCIVar(StringRef Name, DIFile *File,
 323                                          unsigned LineNumber,
 324                                          uint64_t SizeInBits,
 325                                          uint64_t AlignInBits,
 326                                          uint64_t OffsetInBits, unsigned Flags,
 327                                          DIType *Ty, MDNode *PropertyNode) {
 328   return DIDerivedType::get(
 329       VMContext, dwarf::DW_TAG_member, Name, File, LineNumber,
 330       DIScopeRef::get(getNonCompileUnitScope(File)), DITypeRef::get(Ty),
 331       SizeInBits, AlignInBits, OffsetInBits, Flags, PropertyNode);
 332 }
 333
 334 DIObjCProperty *
 335 DIBuilder::createObjCProperty(StringRef Name, DIFile *File, unsigned LineNumber,
 336                               StringRef GetterName, StringRef SetterName,
 337                               unsigned PropertyAttributes, DIType *Ty) {
 338   return DIObjCProperty::get(VMContext, Name, File, LineNumber, GetterName,
 339                              SetterName, PropertyAttributes,
 340                              DITypeRef::get(Ty));
 341 }
 342
 343 DITemplateTypeParameter *
 344 DIBuilder::createTemplateTypeParameter(DIScope *Context, StringRef Name,
 345                                        DIType *Ty) {
 346   assert((!Context || isa<DICompileUnit>(Context)) && "Expected compile unit");
 347   return DITemplateTypeParameter::get(VMContext, Name, DITypeRef::get(Ty));
 348 }
 349
 350 static DITemplateValueParameter *
 351 createTemplateValueParameterHelper(LLVMContext &VMContext, unsigned Tag,
 352                                    DIScope *Context, StringRef Name, DIType *Ty,
 353                                    Metadata *MD) {
 354   assert((!Context || isa<DICompileUnit>(Context)) && "Expected compile unit");
 355   return DITemplateValueParameter::get(VMContext, Tag, Name, DITypeRef::get(Ty),
 356                                        MD);
 357 }
 358
 359 DITemplateValueParameter *
 360 DIBuilder::createTemplateValueParameter(DIScope *Context, StringRef Name,
 361                                         DIType *Ty, Constant *Val) {
 362   return createTemplateValueParameterHelper(
 363       VMContext, dwarf::DW_TAG_template_value_parameter, Context, Name, Ty,
 364       getConstantOrNull(Val));
 365 }
 366
 367 DITemplateValueParameter *
 368 DIBuilder::createTemplateTemplateParameter(DIScope *Context, StringRef Name,
 369                                            DIType *Ty, StringRef Val) {
 370   return createTemplateValueParameterHelper(
 371       VMContext, dwarf::DW_TAG_GNU_template_template_param, Context, Name, Ty,
 372       MDString::get(VMContext, Val));
 373 }
 374
 375 DITemplateValueParameter *
 376 DIBuilder::createTemplateParameterPack(DIScope *Context, StringRef Name,
 377                                        DIType *Ty, DINodeArray Val) {
 378   return createTemplateValueParameterHelper(
 379       VMContext, dwarf::DW_TAG_GNU_template_parameter_pack, Context, Name, Ty,
 380       Val.get());
 381 }
 382
 383 DICompositeType *DIBuilder::createClassType(
 384     DIScope *Context, StringRef Name, DIFile *File, unsigned LineNumber,
 385     uint64_t SizeInBits, uint64_t AlignInBits, uint64_t OffsetInBits,
 386     unsigned Flags, DIType *DerivedFrom, DINodeArray Elements,
 387     DIType *VTableHolder, MDNode *TemplateParams, StringRef UniqueIdentifier) {
 388   assert((!Context || isa<DIScope>(Context)) &&
 389          "createClassType should be called with a valid Context");
 390
 391   auto *R = DICompositeType::get(
 392       VMContext, dwarf::DW_TAG_structure_type, Name, File, LineNumber,
 393       DIScopeRef::get(getNonCompileUnitScope(Context)),
 394       DITypeRef::get(DerivedFrom), SizeInBits, AlignInBits, OffsetInBits, Flags,
 395       Elements, 0, DITypeRef::get(VTableHolder),
 396       cast_or_null<MDTuple>(TemplateParams), UniqueIdentifier);
 397   if (!UniqueIdentifier.empty())
 398     retainType(R);
 399   trackIfUnresolved(R);
 400   return R;
 401 }
 402
 403 DICompositeType *DIBuilder::createStructType(
 404     DIScope *Context, StringRef Name, DIFile *File, unsigned LineNumber,
 405     uint64_t SizeInBits, uint64_t AlignInBits, unsigned Flags,
 406     DIType *DerivedFrom, DINodeArray Elements, unsigned RunTimeLang,
 407     DIType *VTableHolder, StringRef UniqueIdentifier) {
 408   auto *R = DICompositeType::get(
 409       VMContext, dwarf::DW_TAG_structure_type, Name, File, LineNumber,
 410       DIScopeRef::get(getNonCompileUnitScope(Context)),
 411       DITypeRef::get(DerivedFrom), SizeInBits, AlignInBits, 0, Flags, Elements,
 412       RunTimeLang, DITypeRef::get(VTableHolder), nullptr, UniqueIdentifier);
 413   if (!UniqueIdentifier.empty())
 414     retainType(R);
 415   trackIfUnresolved(R);
 416   return R;
 417 }
 418
 419 DICompositeType *DIBuilder::createUnionType(
 420     DIScope *Scope, StringRef Name, DIFile *File, unsigned LineNumber,
 421     uint64_t SizeInBits, uint64_t AlignInBits, unsigned Flags,
 422     DINodeArray Elements, unsigned RunTimeLang, StringRef UniqueIdentifier) {
 423   auto *R = DICompositeType::get(
 424       VMContext, dwarf::DW_TAG_union_type, Name, File, LineNumber,
 425       DIScopeRef::get(getNonCompileUnitScope(Scope)), nullptr, SizeInBits,
 426       AlignInBits, 0, Flags, Elements, RunTimeLang, nullptr, nullptr,
 427       UniqueIdentifier);
 428   if (!UniqueIdentifier.empty())
 429     retainType(R);
 430   trackIfUnresolved(R);
 431   return R;
 432 }
 433
 434 DISubroutineType *DIBuilder::createSubroutineType(DITypeRefArray ParameterTypes,
 435                                                   unsigned Flags) {
 436   return DISubroutineType::get(VMContext, Flags, ParameterTypes);
 437 }
 438
 439 DICompositeType *DIBuilder::createExternalTypeRef(unsigned Tag, DIFile *File,
 440                                                   StringRef UniqueIdentifier) {
 441   assert(!UniqueIdentifier.empty() && "external type ref without uid");
 442   auto *CTy =
 443       DICompositeType::get(VMContext, Tag, "", nullptr, 0, nullptr, nullptr, 0,
 444                            0, 0, DINode::FlagExternalTypeRef, nullptr, 0,
 445                            nullptr, nullptr, UniqueIdentifier);
 446   // Types with unique IDs need to be in the type map.
 447   retainType(CTy);
 448   return CTy;
 449 }
 450
 451 DICompositeType *DIBuilder::createEnumerationType(
 452     DIScope *Scope, StringRef Name, DIFile *File, unsigned LineNumber,
 453     uint64_t SizeInBits, uint64_t AlignInBits, DINodeArray Elements,
 454     DIType *UnderlyingType, StringRef UniqueIdentifier) {
 455   auto *CTy = DICompositeType::get(
 456       VMContext, dwarf::DW_TAG_enumeration_type, Name, File, LineNumber,
 457       DIScopeRef::get(getNonCompileUnitScope(Scope)),
 458       DITypeRef::get(UnderlyingType), SizeInBits, AlignInBits, 0, 0, Elements,
 459       0, nullptr, nullptr, UniqueIdentifier);
 460   AllEnumTypes.push_back(CTy);
 461   if (!UniqueIdentifier.empty())
 462     retainType(CTy);
 463   trackIfUnresolved(CTy);
 464   return CTy;
 465 }
 466
 467 DICompositeType *DIBuilder::createArrayType(uint64_t Size, uint64_t AlignInBits,
 468                                             DIType *Ty,
 469                                             DINodeArray Subscripts) {
 470   auto *R = DICompositeType::get(VMContext, dwarf::DW_TAG_array_type, "",
 471                                  nullptr, 0, nullptr, DITypeRef::get(Ty), Size,
 472                                  AlignInBits, 0, 0, Subscripts, 0, nullptr);
 473   trackIfUnresolved(R);
 474   return R;
 475 }
 476
 477 DICompositeType *DIBuilder::createVectorType(uint64_t Size,
 478                                              uint64_t AlignInBits, DIType *Ty,
 479                                              DINodeArray Subscripts) {
 480   auto *R =
 481       DICompositeType::get(VMContext, dwarf::DW_TAG_array_type, "", nullptr, 0,
 482                            nullptr, DITypeRef::get(Ty), Size, AlignInBits, 0,
 483                            DINode::FlagVector, Subscripts, 0, nullptr);
 484   trackIfUnresolved(R);
 485   return R;
 486 }
 487
 488 static DIType *createTypeWithFlags(LLVMContext &Context, DIType *Ty,
 489                                    unsigned FlagsToSet) {
 490   auto NewTy = Ty->clone();
 491   NewTy->setFlags(NewTy->getFlags() | FlagsToSet);
 492   return MDNode::replaceWithUniqued(std::move(NewTy));
 493 }
 494
 495 DIType *DIBuilder::createArtificialType(DIType *Ty) {
 496   // FIXME: Restrict this to the nodes where it's valid.
 497   if (Ty->isArtificial())
 498     return Ty;
 499   return createTypeWithFlags(VMContext, Ty, DINode::FlagArtificial);
 500 }
 501
 502 DIType *DIBuilder::createObjectPointerType(DIType *Ty) {
 503   // FIXME: Restrict this to the nodes where it's valid.
 504   if (Ty->isObjectPointer())
 505     return Ty;
 506   unsigned Flags = DINode::FlagObjectPointer | DINode::FlagArtificial;
 507   return createTypeWithFlags(VMContext, Ty, Flags);
 508 }
 509
 510 void DIBuilder::retainType(DIType *T) {
 511   assert(T && "Expected non-null type");
 512   AllRetainTypes.emplace_back(T);
 513 }
 514
 515 DIBasicType *DIBuilder::createUnspecifiedParameter() { return nullptr; }
 516
 517 DICompositeType *
 518 DIBuilder::createForwardDecl(unsigned Tag, StringRef Name, DIScope *Scope,
 519                              DIFile *F, unsigned Line, unsigned RuntimeLang,
 520                              uint64_t SizeInBits, uint64_t AlignInBits,
 521                              StringRef UniqueIdentifier) {
 522   // FIXME: Define in terms of createReplaceableForwardDecl() by calling
 523   // replaceWithUniqued().
 524   auto *RetTy = DICompositeType::get(
 525       VMContext, Tag, Name, F, Line,
 526       DIScopeRef::get(getNonCompileUnitScope(Scope)), nullptr, SizeInBits,
 527       AlignInBits, 0, DINode::FlagFwdDecl, nullptr, RuntimeLang, nullptr,
 528       nullptr, UniqueIdentifier);
 529   if (!UniqueIdentifier.empty())
 530     retainType(RetTy);
 531   trackIfUnresolved(RetTy);
 532   return RetTy;
 533 }
 534
 535 DICompositeType *DIBuilder::createReplaceableCompositeType(
 536     unsigned Tag, StringRef Name, DIScope *Scope, DIFile *F, unsigned Line,
 537     unsigned RuntimeLang, uint64_t SizeInBits, uint64_t AlignInBits,
 538     unsigned Flags, StringRef UniqueIdentifier) {
 539   auto *RetTy = DICompositeType::getTemporary(
 540                     VMContext, Tag, Name, F, Line,
 541                     DIScopeRef::get(getNonCompileUnitScope(Scope)), nullptr,
 542                     SizeInBits, AlignInBits, 0, Flags, nullptr, RuntimeLang,
 543                     nullptr, nullptr, UniqueIdentifier)
 544                     .release();
 545   if (!UniqueIdentifier.empty())
 546     retainType(RetTy);
 547   trackIfUnresolved(RetTy);
 548   return RetTy;
 549 }
 550
 551 DINodeArray DIBuilder::getOrCreateArray(ArrayRef<Metadata *> Elements) {
 552   return MDTuple::get(VMContext, Elements);
 553 }
 554
 555 DITypeRefArray DIBuilder::getOrCreateTypeArray(ArrayRef<Metadata *> Elements) {
 556   SmallVector<llvm::Metadata *, 16> Elts;
 557   for (unsigned i = 0, e = Elements.size(); i != e; ++i) {
 558     if (Elements[i] && isa<MDNode>(Elements[i]))
 559       Elts.push_back(DITypeRef::get(cast<DIType>(Elements[i])));
 560     else
 561       Elts.push_back(Elements[i]);
 562   }
 563   return DITypeRefArray(MDNode::get(VMContext, Elts));
 564 }
 565
 566 DISubrange *DIBuilder::getOrCreateSubrange(int64_t Lo, int64_t Count) {
 567   return DISubrange::get(VMContext, Count, Lo);
 568 }
 569
 570 static void checkGlobalVariableScope(DIScope *Context) {
 571 #ifndef NDEBUG
 572   if (auto *CT =
 573           dyn_cast_or_null<DICompositeType>(getNonCompileUnitScope(Context)))
 574     assert(CT->getIdentifier().empty() &&
 575            "Context of a global variable should not be a type with identifier");
 576 #endif
 577 }
 578
 579 DIGlobalVariable *DIBuilder::createGlobalVariable(
 580     DIScope *Context, StringRef Name, StringRef LinkageName, DIFile *F,
 581     unsigned LineNumber, DIType *Ty, bool isLocalToUnit, Constant *Val,
 582     MDNode *Decl) {
 583   checkGlobalVariableScope(Context);
 584
 585   auto *N = DIGlobalVariable::get(VMContext, cast_or_null<DIScope>(Context),
 586                                   Name, LinkageName, F, LineNumber,
 587                                   DITypeRef::get(Ty), isLocalToUnit, true, Val,
 588                                   cast_or_null<DIDerivedType>(Decl));
 589   AllGVs.push_back(N);
 590   return N;
 591 }
 592
 593 DIGlobalVariable *DIBuilder::createTempGlobalVariableFwdDecl(
 594     DIScope *Context, StringRef Name, StringRef LinkageName, DIFile *F,
 595     unsigned LineNumber, DIType *Ty, bool isLocalToUnit, Constant *Val,
 596     MDNode *Decl) {
 597   checkGlobalVariableScope(Context);
 598
 599   return DIGlobalVariable::getTemporary(
 600              VMContext, cast_or_null<DIScope>(Context), Name, LinkageName, F,
 601              LineNumber, DITypeRef::get(Ty), isLocalToUnit, false, Val,
 602              cast_or_null<DIDerivedType>(Decl))
 603       .release();
 604 }
 605
 606 static DILocalVariable *createLocalVariable(
 607     LLVMContext &VMContext,
 608     DenseMap<MDNode *, std::vector<TrackingMDNodeRef>> &PreservedVariables,
 609     DIScope *Scope, StringRef Name, unsigned ArgNo, DIFile *File,
 610     unsigned LineNo, DIType *Ty, bool AlwaysPreserve, unsigned Flags) {
 611   // FIXME: Why getNonCompileUnitScope()?
 612   // FIXME: Why is "!Context" okay here?
 613   // FIXME: Why doesn't this check for a subprogram or lexical block (AFAICT
 614   // the only valid scopes)?
 615   DIScope *Context = getNonCompileUnitScope(Scope);
 616
 617   auto *Node =
 618       DILocalVariable::get(VMContext, cast_or_null<DILocalScope>(Context), Name,
 619                            File, LineNo, DITypeRef::get(Ty), ArgNo, Flags);
 620   if (AlwaysPreserve) {
 621     // The optimizer may remove local variables. If there is an interest
 622     // to preserve variable info in such situation then stash it in a
 623     // named mdnode.
 624     DISubprogram *Fn = getDISubprogram(Scope);
 625     assert(Fn && "Missing subprogram for local variable");
 626     PreservedVariables[Fn].emplace_back(Node);
 627   }
 628   return Node;
 629 }
 630
 631 DILocalVariable *DIBuilder::createAutoVariable(DIScope *Scope, StringRef Name,
 632                                                DIFile *File, unsigned LineNo,
 633                                                DIType *Ty, bool AlwaysPreserve,
 634                                                unsigned Flags) {
 635   return createLocalVariable(VMContext, PreservedVariables, Scope, Name,
 636                              /* ArgNo */ 0, File, LineNo, Ty, AlwaysPreserve,
 637                              Flags);
 638 }
 639
 640 DILocalVariable *DIBuilder::createParameterVariable(
 641     DIScope *Scope, StringRef Name, unsigned ArgNo, DIFile *File,
 642     unsigned LineNo, DIType *Ty, bool AlwaysPreserve, unsigned Flags) {
 643   assert(ArgNo && "Expected non-zero argument number for parameter");
 644   return createLocalVariable(VMContext, PreservedVariables, Scope, Name, ArgNo,
 645                              File, LineNo, Ty, AlwaysPreserve, Flags);
 646 }
 647
 648 DIExpression *DIBuilder::createExpression(ArrayRef<uint64_t> Addr) {
 649   return DIExpression::get(VMContext, Addr);
 650 }
 651
 652 DIExpression *DIBuilder::createExpression(ArrayRef<int64_t> Signed) {
 653   // TODO: Remove the callers of this signed version and delete.
 654   SmallVector<uint64_t, 8> Addr(Signed.begin(), Signed.end());
 655   return createExpression(Addr);
 656 }
 657
 658 DIExpression *DIBuilder::createBitPieceExpression(unsigned OffsetInBytes,
 659                                                   unsigned SizeInBytes) {
 660   uint64_t Addr[] = {dwarf::DW_OP_bit_piece, OffsetInBytes, SizeInBytes};
 661   return DIExpression::get(VMContext, Addr);
 662 }
 663
 664 DISubprogram *DIBuilder::createFunction(
 665     DIScopeRef Context, StringRef Name, StringRef LinkageName, DIFile *File,
 666     unsigned LineNo, DISubroutineType *Ty, bool isLocalToUnit,
 667     bool isDefinition, unsigned ScopeLine, unsigned Flags, bool isOptimized,
 668     DITemplateParameterArray TParams, DISubprogram *Decl) {
 669   // dragonegg does not generate identifier for types, so using an empty map
 670   // to resolve the context should be fine.
 671   DITypeIdentifierMap EmptyMap;
 672   return createFunction(Context.resolve(EmptyMap), Name, LinkageName, File,
 673                         LineNo, Ty, isLocalToUnit, isDefinition, ScopeLine,
 674                         Flags, isOptimized, TParams, Decl);
 675 }
 676
 677 template <class... Ts>
 678 static DISubprogram *getSubprogram(bool IsDistinct, Ts &&... Args) {
 679   if (IsDistinct)
 680     return DISubprogram::getDistinct(std::forward<Ts>(Args)...);
 681   return DISubprogram::get(std::forward<Ts>(Args)...);
 682 }
 683
 684 DISubprogram *DIBuilder::createFunction(
 685     DIScope *Context, StringRef Name, StringRef LinkageName, DIFile *File,
 686     unsigned LineNo, DISubroutineType *Ty, bool isLocalToUnit,
 687     bool isDefinition, unsigned ScopeLine, unsigned Flags, bool isOptimized,
 688     DITemplateParameterArray TParams, DISubprogram *Decl) {
 689   auto *Node =
 690       getSubprogram(/* IsDistinct = */ isDefinition, VMContext,
 691                     DIScopeRef::get(getNonCompileUnitScope(Context)), Name,
 692                     LinkageName, File, LineNo, Ty, isLocalToUnit, isDefinition,
 693                     ScopeLine, nullptr, 0, 0, Flags, isOptimized, TParams, Decl,
 694                     MDTuple::getTemporary(VMContext, None).release());
 695
 696   if (isDefinition)
 697     AllSubprograms.push_back(Node);
 698   trackIfUnresolved(Node);
 699   return Node;
 700 }
 701
 702 DISubprogram *DIBuilder::createTempFunctionFwdDecl(
 703     DIScope *Context, StringRef Name, StringRef LinkageName, DIFile *File,
 704     unsigned LineNo, DISubroutineType *Ty, bool isLocalToUnit,
 705     bool isDefinition, unsigned ScopeLine, unsigned Flags, bool isOptimized,
 706     DITemplateParameterArray TParams, DISubprogram *Decl) {
 707   return DISubprogram::getTemporary(
 708              VMContext, DIScopeRef::get(getNonCompileUnitScope(Context)), Name,
 709              LinkageName, File, LineNo, Ty, isLocalToUnit, isDefinition,
 710              ScopeLine, nullptr, 0, 0, Flags, isOptimized, TParams, Decl,
 711              nullptr)
 712       .release();
 713 }
 714
 715 DISubprogram *
 716 DIBuilder::createMethod(DIScope *Context, StringRef Name, StringRef LinkageName,
 717                         DIFile *F, unsigned LineNo, DISubroutineType *Ty,
 718                         bool isLocalToUnit, bool isDefinition, unsigned VK,
 719                         unsigned VIndex, DIType *VTableHolder, unsigned Flags,
 720                         bool isOptimized, DITemplateParameterArray TParams) {
 721   assert(getNonCompileUnitScope(Context) &&
 722          "Methods should have both a Context and a context that isn't "
 723          "the compile unit.");
 724   // FIXME: Do we want to use different scope/lines?
 725   auto *SP = getSubprogram(
 726       /* IsDistinct = */ isDefinition, VMContext,
 727       DIScopeRef::get(cast<DIScope>(Context)), Name, LinkageName, F, LineNo, Ty,
 728       isLocalToUnit, isDefinition, LineNo, DITypeRef::get(VTableHolder), VK,
 729       VIndex, Flags, isOptimized, TParams, nullptr, nullptr);
 730
 731   if (isDefinition)
 732     AllSubprograms.push_back(SP);
 733   trackIfUnresolved(SP);
 734   return SP;
 735 }
 736
 737 DINamespace *DIBuilder::createNameSpace(DIScope *Scope, StringRef Name,
 738                                         DIFile *File, unsigned LineNo) {
 739   return DINamespace::get(VMContext, getNonCompileUnitScope(Scope), File, Name,
 740                           LineNo);
 741 }
 742
 743 DIModule *DIBuilder::createModule(DIScope *Scope, StringRef Name,
 744                                   StringRef ConfigurationMacros,
 745                                   StringRef IncludePath,
 746                                   StringRef ISysRoot) {
 747  return DIModule::get(VMContext, getNonCompileUnitScope(Scope), Name,
 748                       ConfigurationMacros, IncludePath, ISysRoot);
 749 }
 750
 751 DILexicalBlockFile *DIBuilder::createLexicalBlockFile(DIScope *Scope,
 752                                                       DIFile *File,
 753                                                       unsigned Discriminator) {
 754   return DILexicalBlockFile::get(VMContext, Scope, File, Discriminator);
 755 }
 756
 757 DILexicalBlock *DIBuilder::createLexicalBlock(DIScope *Scope, DIFile *File,
 758                                               unsigned Line, unsigned Col) {
 759   // Make these distinct, to avoid merging two lexical blocks on the same
 760   // file/line/column.
 761   return DILexicalBlock::getDistinct(VMContext, getNonCompileUnitScope(Scope),
 762                                      File, Line, Col);
 763 }
 764
 765 static Value *getDbgIntrinsicValueImpl(LLVMContext &VMContext, Value *V) {
 766   assert(V && "no value passed to dbg intrinsic");
 767   return MetadataAsValue::get(VMContext, ValueAsMetadata::get(V));
 768 }
 769
 770 static Instruction *withDebugLoc(Instruction *I, const DILocation *DL) {
 771   I->setDebugLoc(const_cast<DILocation *>(DL));
 772   return I;
 773 }
 774
 775 Instruction *DIBuilder::insertDeclare(Value *Storage, DILocalVariable *VarInfo,
 776                                       DIExpression *Expr, const DILocation *DL,
 777                                       Instruction *InsertBefore) {
 778   assert(VarInfo && "empty or invalid DILocalVariable* passed to dbg.declare");
 779   assert(DL && "Expected debug loc");
 780   assert(DL->getScope()->getSubprogram() ==
 781              VarInfo->getScope()->getSubprogram() &&
 782          "Expected matching subprograms");
 783   if (!DeclareFn)
 784     DeclareFn = Intrinsic::getDeclaration(&M, Intrinsic::dbg_declare);
 785
 786   trackIfUnresolved(VarInfo);
 787   trackIfUnresolved(Expr);
 788   Value *Args[] = {getDbgIntrinsicValueImpl(VMContext, Storage),
 789                    MetadataAsValue::get(VMContext, VarInfo),
 790                    MetadataAsValue::get(VMContext, Expr)};
 791   return withDebugLoc(CallInst::Create(DeclareFn, Args, "", InsertBefore), DL);
 792 }
 793
 794 Instruction *DIBuilder::insertDeclare(Value *Storage, DILocalVariable *VarInfo,
 795                                       DIExpression *Expr, const DILocation *DL,
 796                                       BasicBlock *InsertAtEnd) {
 797   assert(VarInfo && "empty or invalid DILocalVariable* passed to dbg.declare");
 798   assert(DL && "Expected debug loc");
 799   assert(DL->getScope()->getSubprogram() ==
 800              VarInfo->getScope()->getSubprogram() &&
 801          "Expected matching subprograms");
 802   if (!DeclareFn)
 803     DeclareFn = Intrinsic::getDeclaration(&M, Intrinsic::dbg_declare);
 804
 805   trackIfUnresolved(VarInfo);
 806   trackIfUnresolved(Expr);
 807   Value *Args[] = {getDbgIntrinsicValueImpl(VMContext, Storage),
 808                    MetadataAsValue::get(VMContext, VarInfo),
 809                    MetadataAsValue::get(VMContext, Expr)};
 810
 811   // If this block already has a terminator then insert this intrinsic
 812   // before the terminator.
 813   if (TerminatorInst *T = InsertAtEnd->getTerminator())
 814     return withDebugLoc(CallInst::Create(DeclareFn, Args, "", T), DL);
 815   return withDebugLoc(CallInst::Create(DeclareFn, Args, "", InsertAtEnd), DL);
 816 }
 817
 818 Instruction *DIBuilder::insertDbgValueIntrinsic(Value *V, uint64_t Offset,
 819                                                 DILocalVariable *VarInfo,
 820                                                 DIExpression *Expr,
 821                                                 const DILocation *DL,
 822                                                 Instruction *InsertBefore) {
 823   assert(V && "no value passed to dbg.value");
 824   assert(VarInfo && "empty or invalid DILocalVariable* passed to dbg.value");
 825   assert(DL && "Expected debug loc");
 826   assert(DL->getScope()->getSubprogram() ==
 827              VarInfo->getScope()->getSubprogram() &&
 828          "Expected matching subprograms");
 829   if (!ValueFn)
 830     ValueFn = Intrinsic::getDeclaration(&M, Intrinsic::dbg_value);
 831
 832   trackIfUnresolved(VarInfo);
 833   trackIfUnresolved(Expr);
 834   Value *Args[] = {getDbgIntrinsicValueImpl(VMContext, V),
 835                    ConstantInt::get(Type::getInt64Ty(VMContext), Offset),
 836                    MetadataAsValue::get(VMContext, VarInfo),
 837                    MetadataAsValue::get(VMContext, Expr)};
 838   return withDebugLoc(CallInst::Create(ValueFn, Args, "", InsertBefore), DL);
 839 }
 840
 841 Instruction *DIBuilder::insertDbgValueIntrinsic(Value *V, uint64_t Offset,
 842                                                 DILocalVariable *VarInfo,
 843                                                 DIExpression *Expr,
 844                                                 const DILocation *DL,
 845                                                 BasicBlock *InsertAtEnd) {
 846   assert(V && "no value passed to dbg.value");
 847   assert(VarInfo && "empty or invalid DILocalVariable* passed to dbg.value");
 848   assert(DL && "Expected debug loc");
 849   assert(DL->getScope()->getSubprogram() ==
 850              VarInfo->getScope()->getSubprogram() &&
 851          "Expected matching subprograms");
 852   if (!ValueFn)
 853     ValueFn = Intrinsic::getDeclaration(&M, Intrinsic::dbg_value);
 854
 855   trackIfUnresolved(VarInfo);
 856   trackIfUnresolved(Expr);
 857   Value *Args[] = {getDbgIntrinsicValueImpl(VMContext, V),
 858                    ConstantInt::get(Type::getInt64Ty(VMContext), Offset),
 859                    MetadataAsValue::get(VMContext, VarInfo),
 860                    MetadataAsValue::get(VMContext, Expr)};
 861
 862   return withDebugLoc(CallInst::Create(ValueFn, Args, "", InsertAtEnd), DL);
 863 }
 864
 865 void DIBuilder::replaceVTableHolder(DICompositeType *&T,
 866                                     DICompositeType *VTableHolder) {
 867   {
 868     TypedTrackingMDRef<DICompositeType> N(T);
 869     N->replaceVTableHolder(DITypeRef::get(VTableHolder));
 870     T = N.get();
 871   }
 872
 873   // If this didn't create a self-reference, just return.
 874   if (T != VTableHolder)
 875     return;
 876
 877   // Look for unresolved operands.  T will drop RAUW support, orphaning any
 878   // cycles underneath it.
 879   if (T->isResolved())
 880     for (const MDOperand &O : T->operands())
 881       if (auto *N = dyn_cast_or_null<MDNode>(O))
 882         trackIfUnresolved(N);
 883 }
 884
 885 void DIBuilder::replaceArrays(DICompositeType *&T, DINodeArray Elements,
 886                               DINodeArray TParams) {
 887   {
 888     TypedTrackingMDRef<DICompositeType> N(T);
 889     if (Elements)
 890       N->replaceElements(Elements);
 891     if (TParams)
 892       N->replaceTemplateParams(DITemplateParameterArray(TParams));
 893     T = N.get();
 894   }
 895
 896   // If T isn't resolved, there's no problem.
 897   if (!T->isResolved())
 898     return;
 899
 900   // If T is resolved, it may be due to a self-reference cycle.  Track the
 901   // arrays explicitly if they're unresolved, or else the cycles will be
 902   // orphaned.
 903   if (Elements)
 904     trackIfUnresolved(Elements.get());
 905   if (TParams)
 906     trackIfUnresolved(TParams.get());
 907 }