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 "LLVMContextImpl.h"
  16 #include "llvm/ADT/STLExtras.h"
  17 #include "llvm/IR/Constants.h"
  18 #include "llvm/IR/DebugInfo.h"
  19 #include "llvm/IR/IntrinsicInst.h"
  20 #include "llvm/IR/Module.h"
  21 #include "llvm/Support/Debug.h"
  22 #include "llvm/Support/Dwarf.h"
  23
  24 using namespace llvm;
  25 using namespace llvm::dwarf;
  26
  27 DIBuilder::DIBuilder(Module &m, bool AllowUnresolvedNodes)
  28   : M(m), VMContext(M.getContext()), CUNode(nullptr),
  29       DeclareFn(nullptr), ValueFn(nullptr),
  30       AllowUnresolvedNodes(AllowUnresolvedNodes) {}
  31
  32 void DIBuilder::trackIfUnresolved(MDNode *N) {
  33   if (!N)
  34     return;
  35   if (N->isResolved())
  36     return;
  37
  38   assert(AllowUnresolvedNodes && "Cannot handle unresolved nodes");
  39   UnresolvedNodes.emplace_back(N);
  40 }
  41
  42 void DIBuilder::finalizeSubprogram(DISubprogram *SP) {
  43   MDTuple *Temp = SP->getVariables().get();
  44   if (!Temp || !Temp->isTemporary())
  45     return;
  46
  47   SmallVector<Metadata *, 4> Variables;
  48
  49   auto PV = PreservedVariables.find(SP);
  50   if (PV != PreservedVariables.end())
  51     Variables.append(PV->second.begin(), PV->second.end());
  52
  53   DINodeArray AV = getOrCreateArray(Variables);
  54   TempMDTuple(Temp)->replaceAllUsesWith(AV.get());
  55 }
  56
  57 void DIBuilder::finalize() {
  58   if (!CUNode) {
  59     assert(!AllowUnresolvedNodes &&
  60            "creating type nodes without a CU is not supported");
  61     return;
  62   }
  63
  64   CUNode->replaceEnumTypes(MDTuple::get(VMContext, AllEnumTypes));
  65
  66   SmallVector<Metadata *, 16> RetainValues;
  67   // Declarations and definitions of the same type may be retained. Some
  68   // clients RAUW these pairs, leaving duplicates in the retained types
  69   // list. Use a set to remove the duplicates while we transform the
  70   // TrackingVHs back into Values.
  71   SmallPtrSet<Metadata *, 16> RetainSet;
  72   for (unsigned I = 0, E = AllRetainTypes.size(); I < E; I++)
  73     if (RetainSet.insert(AllRetainTypes[I]).second)
  74       RetainValues.push_back(AllRetainTypes[I]);
  75
  76   if (!RetainValues.empty())
  77     CUNode->replaceRetainedTypes(MDTuple::get(VMContext, RetainValues));
  78
  79   DISubprogramArray SPs = MDTuple::get(VMContext, AllSubprograms);
  80   for (auto *SP : SPs)
  81     finalizeSubprogram(SP);
  82   for (auto *N : RetainValues)
  83     if (auto *SP = dyn_cast<DISubprogram>(N))
  84       finalizeSubprogram(SP);
  85
  86   if (!AllGVs.empty())
  87     CUNode->replaceGlobalVariables(MDTuple::get(VMContext, AllGVs));
  88
  89   if (!AllImportedModules.empty())
  90     CUNode->replaceImportedEntities(MDTuple::get(
  91         VMContext, SmallVector<Metadata *, 16>(AllImportedModules.begin(),
  92                                                AllImportedModules.end())));
  93
  94   for (const auto &I : AllMacrosPerParent) {
  95     // DIMacroNode's with nullptr parent are DICompileUnit direct children.
  96     if (!I.first) {
  97       CUNode->replaceMacros(MDTuple::get(VMContext, I.second.getArrayRef()));
  98       continue;
  99     }
 100     // Otherwise, it must be a temporary DIMacroFile that need to be resolved.
 101     auto *TMF = cast<DIMacroFile>(I.first);
 102     auto *MF = DIMacroFile::get(VMContext, dwarf::DW_MACINFO_start_file,
 103                                 TMF->getLine(), TMF->getFile(),
 104                                 getOrCreateMacroArray(I.second.getArrayRef()));
 105     replaceTemporary(llvm::TempDIMacroNode(TMF), MF);
 106   }
 107
 108   // Now that all temp nodes have been replaced or deleted, resolve remaining
 109   // cycles.
 110   for (const auto &N : UnresolvedNodes)
 111     if (N && !N->isResolved())
 112       N->resolveCycles();
 113   UnresolvedNodes.clear();
 114
 115   // Can't handle unresolved nodes anymore.
 116   AllowUnresolvedNodes = false;
 117 }
 118
 119 /// If N is compile unit return NULL otherwise return N.
 120 static DIScope *getNonCompileUnitScope(DIScope *N) {
 121   if (!N || isa<DICompileUnit>(N))
 122     return nullptr;
 123   return cast<DIScope>(N);
 124 }
 125
 126 DICompileUnit *DIBuilder::createCompileUnit(
 127     unsigned Lang, DIFile *File, StringRef Producer, bool isOptimized,
 128     StringRef Flags, unsigned RunTimeVer, StringRef SplitName,
 129     DICompileUnit::DebugEmissionKind Kind, uint64_t DWOId,
 130     bool SplitDebugInlining, bool DebugInfoForProfiling) {
 131
 132   assert(((Lang <= dwarf::DW_LANG_Fortran08 && Lang >= dwarf::DW_LANG_C89) ||
 133           (Lang <= dwarf::DW_LANG_hi_user && Lang >= dwarf::DW_LANG_lo_user)) &&
 134          "Invalid Language tag");
 135
 136   assert(!CUNode && "Can only make one compile unit per DIBuilder instance");
 137   CUNode = DICompileUnit::getDistinct(
 138       VMContext, Lang, File, Producer, isOptimized, Flags, RunTimeVer,
 139       SplitName, Kind, nullptr, nullptr, nullptr, nullptr, nullptr, DWOId,
 140       SplitDebugInlining, DebugInfoForProfiling);
 141
 142   // Create a named metadata so that it is easier to find cu in a module.
 143   NamedMDNode *NMD = M.getOrInsertNamedMetadata("llvm.dbg.cu");
 144   NMD->addOperand(CUNode);
 145   trackIfUnresolved(CUNode);
 146   return CUNode;
 147 }
 148
 149 static DIImportedEntity *
 150 createImportedModule(LLVMContext &C, dwarf::Tag Tag, DIScope *Context,
 151                      Metadata *NS, unsigned Line, StringRef Name,
 152                      SmallVectorImpl<TrackingMDNodeRef> &AllImportedModules) {
 153   unsigned EntitiesCount = C.pImpl->DIImportedEntitys.size();
 154   auto *M = DIImportedEntity::get(C, Tag, Context, DINodeRef(NS), Line, Name);
 155   if (EntitiesCount < C.pImpl->DIImportedEntitys.size())
 156     // A new Imported Entity was just added to the context.
 157     // Add it to the Imported Modules list.
 158     AllImportedModules.emplace_back(M);
 159   return M;
 160 }
 161
 162 DIImportedEntity *DIBuilder::createImportedModule(DIScope *Context,
 163                                                   DINamespace *NS,
 164                                                   unsigned Line) {
 165   return ::createImportedModule(VMContext, dwarf::DW_TAG_imported_module,
 166                                 Context, NS, Line, StringRef(), AllImportedModules);
 167 }
 168
 169 DIImportedEntity *DIBuilder::createImportedModule(DIScope *Context,
 170                                                   DIImportedEntity *NS,
 171                                                   unsigned Line) {
 172   return ::createImportedModule(VMContext, dwarf::DW_TAG_imported_module,
 173                                 Context, NS, Line, StringRef(), AllImportedModules);
 174 }
 175
 176 DIImportedEntity *DIBuilder::createImportedModule(DIScope *Context, DIModule *M,
 177                                                   unsigned Line) {
 178   return ::createImportedModule(VMContext, dwarf::DW_TAG_imported_module,
 179                                 Context, M, Line, StringRef(), AllImportedModules);
 180 }
 181
 182 DIImportedEntity *DIBuilder::createImportedDeclaration(DIScope *Context,
 183                                                        DINode *Decl,
 184                                                        unsigned Line,
 185                                                        StringRef Name) {
 186   // Make sure to use the unique identifier based metadata reference for
 187   // types that have one.
 188   return ::createImportedModule(VMContext, dwarf::DW_TAG_imported_declaration,
 189                                 Context, Decl, Line, Name, AllImportedModules);
 190 }
 191
 192 DIFile *DIBuilder::createFile(StringRef Filename, StringRef Directory,
 193                               DIFile::ChecksumKind CSKind, StringRef Checksum) {
 194   return DIFile::get(VMContext, Filename, Directory, CSKind, Checksum);
 195 }
 196
 197 DIMacro *DIBuilder::createMacro(DIMacroFile *Parent, unsigned LineNumber,
 198                                 unsigned MacroType, StringRef Name,
 199                                 StringRef Value) {
 200   assert(!Name.empty() && "Unable to create macro without name");
 201   assert((MacroType == dwarf::DW_MACINFO_undef ||
 202           MacroType == dwarf::DW_MACINFO_define) &&
 203          "Unexpected macro type");
 204   auto *M = DIMacro::get(VMContext, MacroType, LineNumber, Name, Value);
 205   AllMacrosPerParent[Parent].insert(M);
 206   return M;
 207 }
 208
 209 DIMacroFile *DIBuilder::createTempMacroFile(DIMacroFile *Parent,
 210                                             unsigned LineNumber, DIFile *File) {
 211   auto *MF = DIMacroFile::getTemporary(VMContext, dwarf::DW_MACINFO_start_file,
 212                                        LineNumber, File, DIMacroNodeArray())
 213                  .release();
 214   AllMacrosPerParent[Parent].insert(MF);
 215   // Add the new temporary DIMacroFile to the macro per parent map as a parent.
 216   // This is needed to assure DIMacroFile with no children to have an entry in
 217   // the map. Otherwise, it will not be resolved in DIBuilder::finalize().
 218   AllMacrosPerParent.insert({MF, {}});
 219   return MF;
 220 }
 221
 222 DIEnumerator *DIBuilder::createEnumerator(StringRef Name, int64_t Val) {
 223   assert(!Name.empty() && "Unable to create enumerator without name");
 224   return DIEnumerator::get(VMContext, Val, Name);
 225 }
 226
 227 DIBasicType *DIBuilder::createUnspecifiedType(StringRef Name) {
 228   assert(!Name.empty() && "Unable to create type without name");
 229   return DIBasicType::get(VMContext, dwarf::DW_TAG_unspecified_type, Name);
 230 }
 231
 232 DIBasicType *DIBuilder::createNullPtrType() {
 233   return createUnspecifiedType("decltype(nullptr)");
 234 }
 235
 236 DIBasicType *DIBuilder::createBasicType(StringRef Name, uint64_t SizeInBits,
 237                                         unsigned Encoding) {
 238   assert(!Name.empty() && "Unable to create type without name");
 239   return DIBasicType::get(VMContext, dwarf::DW_TAG_base_type, Name, SizeInBits,
 240                           0, Encoding);
 241 }
 242
 243 DIDerivedType *DIBuilder::createQualifiedType(unsigned Tag, DIType *FromTy) {
 244   return DIDerivedType::get(VMContext, Tag, "", nullptr, 0, nullptr, FromTy, 0,
 245                             0, 0, None, DINode::FlagZero);
 246 }
 247
 248 DIDerivedType *DIBuilder::createPointerType(
 249     DIType *PointeeTy,
 250     uint64_t SizeInBits,
 251     uint32_t AlignInBits,
 252     Optional<unsigned> DWARFAddressSpace,
 253     StringRef Name) {
 254   // FIXME: Why is there a name here?
 255   return DIDerivedType::get(VMContext, dwarf::DW_TAG_pointer_type, Name,
 256                             nullptr, 0, nullptr, PointeeTy, SizeInBits,
 257                             AlignInBits, 0, DWARFAddressSpace,
 258                             DINode::FlagZero);
 259 }
 260
 261 DIDerivedType *DIBuilder::createMemberPointerType(DIType *PointeeTy,
 262                                                   DIType *Base,
 263                                                   uint64_t SizeInBits,
 264                                                   uint32_t AlignInBits,
 265                                                   DINode::DIFlags Flags) {
 266   return DIDerivedType::get(VMContext, dwarf::DW_TAG_ptr_to_member_type, "",
 267                             nullptr, 0, nullptr, PointeeTy, SizeInBits,
 268                             AlignInBits, 0, None, Flags, Base);
 269 }
 270
 271 DIDerivedType *DIBuilder::createReferenceType(
 272     unsigned Tag, DIType *RTy,
 273     uint64_t SizeInBits,
 274     uint32_t AlignInBits,
 275     Optional<unsigned> DWARFAddressSpace) {
 276   assert(RTy && "Unable to create reference type");
 277   return DIDerivedType::get(VMContext, Tag, "", nullptr, 0, nullptr, RTy,
 278                             SizeInBits, AlignInBits, 0, DWARFAddressSpace,
 279                             DINode::FlagZero);
 280 }
 281
 282 DIDerivedType *DIBuilder::createTypedef(DIType *Ty, StringRef Name,
 283                                         DIFile *File, unsigned LineNo,
 284                                         DIScope *Context) {
 285   return DIDerivedType::get(VMContext, dwarf::DW_TAG_typedef, Name, File,
 286                             LineNo, getNonCompileUnitScope(Context), Ty, 0, 0,
 287                             0, None, DINode::FlagZero);
 288 }
 289
 290 DIDerivedType *DIBuilder::createFriend(DIType *Ty, DIType *FriendTy) {
 291   assert(Ty && "Invalid type!");
 292   assert(FriendTy && "Invalid friend type!");
 293   return DIDerivedType::get(VMContext, dwarf::DW_TAG_friend, "", nullptr, 0, Ty,
 294                             FriendTy, 0, 0, 0, None, DINode::FlagZero);
 295 }
 296
 297 DIDerivedType *DIBuilder::createInheritance(DIType *Ty, DIType *BaseTy,
 298                                             uint64_t BaseOffset,
 299                                             DINode::DIFlags Flags) {
 300   assert(Ty && "Unable to create inheritance");
 301   return DIDerivedType::get(VMContext, dwarf::DW_TAG_inheritance, "", nullptr,
 302                             0, Ty, BaseTy, 0, 0, BaseOffset, None, Flags);
 303 }
 304
 305 DIDerivedType *DIBuilder::createMemberType(DIScope *Scope, StringRef Name,
 306                                            DIFile *File, unsigned LineNumber,
 307                                            uint64_t SizeInBits,
 308                                            uint32_t AlignInBits,
 309                                            uint64_t OffsetInBits,
 310                                            DINode::DIFlags Flags, DIType *Ty) {
 311   return DIDerivedType::get(VMContext, dwarf::DW_TAG_member, Name, File,
 312                             LineNumber, getNonCompileUnitScope(Scope), Ty,
 313                             SizeInBits, AlignInBits, OffsetInBits, None, Flags);
 314 }
 315
 316 static ConstantAsMetadata *getConstantOrNull(Constant *C) {
 317   if (C)
 318     return ConstantAsMetadata::get(C);
 319   return nullptr;
 320 }
 321
 322 DIDerivedType *DIBuilder::createBitFieldMemberType(
 323     DIScope *Scope, StringRef Name, DIFile *File, unsigned LineNumber,
 324     uint64_t SizeInBits, uint64_t OffsetInBits, uint64_t StorageOffsetInBits,
 325     DINode::DIFlags Flags, DIType *Ty) {
 326   Flags |= DINode::FlagBitField;
 327   return DIDerivedType::get(
 328       VMContext, dwarf::DW_TAG_member, Name, File, LineNumber,
 329       getNonCompileUnitScope(Scope), Ty, SizeInBits, /* AlignInBits */ 0,
 330       OffsetInBits, None, Flags,
 331       ConstantAsMetadata::get(ConstantInt::get(IntegerType::get(VMContext, 64),
 332                                                StorageOffsetInBits)));
 333 }
 334
 335 DIDerivedType *
 336 DIBuilder::createStaticMemberType(DIScope *Scope, StringRef Name, DIFile *File,
 337                                   unsigned LineNumber, DIType *Ty,
 338                                   DINode::DIFlags Flags, llvm::Constant *Val,
 339                                   uint32_t AlignInBits) {
 340   Flags |= DINode::FlagStaticMember;
 341   return DIDerivedType::get(VMContext, dwarf::DW_TAG_member, Name, File,
 342                             LineNumber, getNonCompileUnitScope(Scope), Ty, 0,
 343                             AlignInBits, 0, None, Flags,
 344                             getConstantOrNull(Val));
 345 }
 346
 347 DIDerivedType *
 348 DIBuilder::createObjCIVar(StringRef Name, DIFile *File, unsigned LineNumber,
 349                           uint64_t SizeInBits, uint32_t AlignInBits,
 350                           uint64_t OffsetInBits, DINode::DIFlags Flags,
 351                           DIType *Ty, MDNode *PropertyNode) {
 352   return DIDerivedType::get(VMContext, dwarf::DW_TAG_member, Name, File,
 353                             LineNumber, getNonCompileUnitScope(File), Ty,
 354                             SizeInBits, AlignInBits, OffsetInBits, None, Flags,
 355                             PropertyNode);
 356 }
 357
 358 DIObjCProperty *
 359 DIBuilder::createObjCProperty(StringRef Name, DIFile *File, unsigned LineNumber,
 360                               StringRef GetterName, StringRef SetterName,
 361                               unsigned PropertyAttributes, DIType *Ty) {
 362   return DIObjCProperty::get(VMContext, Name, File, LineNumber, GetterName,
 363                              SetterName, PropertyAttributes, Ty);
 364 }
 365
 366 DITemplateTypeParameter *
 367 DIBuilder::createTemplateTypeParameter(DIScope *Context, StringRef Name,
 368                                        DIType *Ty) {
 369   assert((!Context || isa<DICompileUnit>(Context)) && "Expected compile unit");
 370   return DITemplateTypeParameter::get(VMContext, Name, Ty);
 371 }
 372
 373 static DITemplateValueParameter *
 374 createTemplateValueParameterHelper(LLVMContext &VMContext, unsigned Tag,
 375                                    DIScope *Context, StringRef Name, DIType *Ty,
 376                                    Metadata *MD) {
 377   assert((!Context || isa<DICompileUnit>(Context)) && "Expected compile unit");
 378   return DITemplateValueParameter::get(VMContext, Tag, Name, Ty, MD);
 379 }
 380
 381 DITemplateValueParameter *
 382 DIBuilder::createTemplateValueParameter(DIScope *Context, StringRef Name,
 383                                         DIType *Ty, Constant *Val) {
 384   return createTemplateValueParameterHelper(
 385       VMContext, dwarf::DW_TAG_template_value_parameter, Context, Name, Ty,
 386       getConstantOrNull(Val));
 387 }
 388
 389 DITemplateValueParameter *
 390 DIBuilder::createTemplateTemplateParameter(DIScope *Context, StringRef Name,
 391                                            DIType *Ty, StringRef Val) {
 392   return createTemplateValueParameterHelper(
 393       VMContext, dwarf::DW_TAG_GNU_template_template_param, Context, Name, Ty,
 394       MDString::get(VMContext, Val));
 395 }
 396
 397 DITemplateValueParameter *
 398 DIBuilder::createTemplateParameterPack(DIScope *Context, StringRef Name,
 399                                        DIType *Ty, DINodeArray Val) {
 400   return createTemplateValueParameterHelper(
 401       VMContext, dwarf::DW_TAG_GNU_template_parameter_pack, Context, Name, Ty,
 402       Val.get());
 403 }
 404
 405 DICompositeType *DIBuilder::createClassType(
 406     DIScope *Context, StringRef Name, DIFile *File, unsigned LineNumber,
 407     uint64_t SizeInBits, uint32_t AlignInBits, uint64_t OffsetInBits,
 408     DINode::DIFlags Flags, DIType *DerivedFrom, DINodeArray Elements,
 409     DIType *VTableHolder, MDNode *TemplateParams, StringRef UniqueIdentifier) {
 410   assert((!Context || isa<DIScope>(Context)) &&
 411          "createClassType should be called with a valid Context");
 412
 413   auto *R = DICompositeType::get(
 414       VMContext, dwarf::DW_TAG_structure_type, Name, File, LineNumber,
 415       getNonCompileUnitScope(Context), DerivedFrom, SizeInBits, AlignInBits,
 416       OffsetInBits, Flags, Elements, 0, VTableHolder,
 417       cast_or_null<MDTuple>(TemplateParams), UniqueIdentifier);
 418   trackIfUnresolved(R);
 419   return R;
 420 }
 421
 422 DICompositeType *DIBuilder::createStructType(
 423     DIScope *Context, StringRef Name, DIFile *File, unsigned LineNumber,
 424     uint64_t SizeInBits, uint32_t AlignInBits, DINode::DIFlags Flags,
 425     DIType *DerivedFrom, DINodeArray Elements, unsigned RunTimeLang,
 426     DIType *VTableHolder, StringRef UniqueIdentifier) {
 427   auto *R = DICompositeType::get(
 428       VMContext, dwarf::DW_TAG_structure_type, Name, File, LineNumber,
 429       getNonCompileUnitScope(Context), DerivedFrom, SizeInBits, AlignInBits, 0,
 430       Flags, Elements, RunTimeLang, VTableHolder, nullptr, UniqueIdentifier);
 431   trackIfUnresolved(R);
 432   return R;
 433 }
 434
 435 DICompositeType *DIBuilder::createUnionType(
 436     DIScope *Scope, StringRef Name, DIFile *File, unsigned LineNumber,
 437     uint64_t SizeInBits, uint32_t AlignInBits, DINode::DIFlags Flags,
 438     DINodeArray Elements, unsigned RunTimeLang, StringRef UniqueIdentifier) {
 439   auto *R = DICompositeType::get(
 440       VMContext, dwarf::DW_TAG_union_type, Name, File, LineNumber,
 441       getNonCompileUnitScope(Scope), nullptr, SizeInBits, AlignInBits, 0, Flags,
 442       Elements, RunTimeLang, nullptr, nullptr, UniqueIdentifier);
 443   trackIfUnresolved(R);
 444   return R;
 445 }
 446
 447 DISubroutineType *DIBuilder::createSubroutineType(DITypeRefArray ParameterTypes,
 448                                                   DINode::DIFlags Flags,
 449                                                   unsigned CC) {
 450   return DISubroutineType::get(VMContext, Flags, CC, ParameterTypes);
 451 }
 452
 453 DICompositeType *DIBuilder::createEnumerationType(
 454     DIScope *Scope, StringRef Name, DIFile *File, unsigned LineNumber,
 455     uint64_t SizeInBits, uint32_t AlignInBits, DINodeArray Elements,
 456     DIType *UnderlyingType, StringRef UniqueIdentifier) {
 457   auto *CTy = DICompositeType::get(
 458       VMContext, dwarf::DW_TAG_enumeration_type, Name, File, LineNumber,
 459       getNonCompileUnitScope(Scope), UnderlyingType, SizeInBits, AlignInBits, 0,
 460       DINode::FlagZero, Elements, 0, nullptr, nullptr, UniqueIdentifier);
 461   AllEnumTypes.push_back(CTy);
 462   trackIfUnresolved(CTy);
 463   return CTy;
 464 }
 465
 466 DICompositeType *DIBuilder::createArrayType(uint64_t Size,
 467                                             uint32_t AlignInBits, DIType *Ty,
 468                                             DINodeArray Subscripts) {
 469   auto *R = DICompositeType::get(VMContext, dwarf::DW_TAG_array_type, "",
 470                                  nullptr, 0, nullptr, Ty, Size, AlignInBits, 0,
 471                                  DINode::FlagZero, Subscripts, 0, nullptr);
 472   trackIfUnresolved(R);
 473   return R;
 474 }
 475
 476 DICompositeType *DIBuilder::createVectorType(uint64_t Size,
 477                                              uint32_t AlignInBits, DIType *Ty,
 478                                              DINodeArray Subscripts) {
 479   auto *R = DICompositeType::get(VMContext, dwarf::DW_TAG_array_type, "",
 480                                  nullptr, 0, nullptr, Ty, Size, AlignInBits, 0,
 481                                  DINode::FlagVector, Subscripts, 0, nullptr);
 482   trackIfUnresolved(R);
 483   return R;
 484 }
 485
 486 static DIType *createTypeWithFlags(LLVMContext &Context, DIType *Ty,
 487                                    DINode::DIFlags FlagsToSet) {
 488   auto NewTy = Ty->clone();
 489   NewTy->setFlags(NewTy->getFlags() | FlagsToSet);
 490   return MDNode::replaceWithUniqued(std::move(NewTy));
 491 }
 492
 493 DIType *DIBuilder::createArtificialType(DIType *Ty) {
 494   // FIXME: Restrict this to the nodes where it's valid.
 495   if (Ty->isArtificial())
 496     return Ty;
 497   return createTypeWithFlags(VMContext, Ty, DINode::FlagArtificial);
 498 }
 499
 500 DIType *DIBuilder::createObjectPointerType(DIType *Ty) {
 501   // FIXME: Restrict this to the nodes where it's valid.
 502   if (Ty->isObjectPointer())
 503     return Ty;
 504   DINode::DIFlags Flags = DINode::FlagObjectPointer | DINode::FlagArtificial;
 505   return createTypeWithFlags(VMContext, Ty, Flags);
 506 }
 507
 508 void DIBuilder::retainType(DIScope *T) {
 509   assert(T && "Expected non-null type");
 510   assert((isa<DIType>(T) || (isa<DISubprogram>(T) &&
 511                              cast<DISubprogram>(T)->isDefinition() == false)) &&
 512          "Expected type or subprogram declaration");
 513   AllRetainTypes.emplace_back(T);
 514 }
 515
 516 DIBasicType *DIBuilder::createUnspecifiedParameter() { return nullptr; }
 517
 518 DICompositeType *
 519 DIBuilder::createForwardDecl(unsigned Tag, StringRef Name, DIScope *Scope,
 520                              DIFile *F, unsigned Line, unsigned RuntimeLang,
 521                              uint64_t SizeInBits, uint32_t AlignInBits,
 522                              StringRef UniqueIdentifier) {
 523   // FIXME: Define in terms of createReplaceableForwardDecl() by calling
 524   // replaceWithUniqued().
 525   auto *RetTy = DICompositeType::get(
 526       VMContext, Tag, Name, F, Line, getNonCompileUnitScope(Scope), nullptr,
 527       SizeInBits, AlignInBits, 0, DINode::FlagFwdDecl, nullptr, RuntimeLang,
 528       nullptr, nullptr, UniqueIdentifier);
 529   trackIfUnresolved(RetTy);
 530   return RetTy;
 531 }
 532
 533 DICompositeType *DIBuilder::createReplaceableCompositeType(
 534     unsigned Tag, StringRef Name, DIScope *Scope, DIFile *F, unsigned Line,
 535     unsigned RuntimeLang, uint64_t SizeInBits, uint32_t AlignInBits,
 536     DINode::DIFlags Flags, StringRef UniqueIdentifier) {
 537   auto *RetTy =
 538       DICompositeType::getTemporary(
 539           VMContext, Tag, Name, F, Line, getNonCompileUnitScope(Scope), nullptr,
 540           SizeInBits, AlignInBits, 0, Flags, nullptr, RuntimeLang, nullptr,
 541           nullptr, UniqueIdentifier)
 542           .release();
 543   trackIfUnresolved(RetTy);
 544   return RetTy;
 545 }
 546
 547 DINodeArray DIBuilder::getOrCreateArray(ArrayRef<Metadata *> Elements) {
 548   return MDTuple::get(VMContext, Elements);
 549 }
 550
 551 DIMacroNodeArray
 552 DIBuilder::getOrCreateMacroArray(ArrayRef<Metadata *> Elements) {
 553   return MDTuple::get(VMContext, Elements);
 554 }
 555
 556 DITypeRefArray DIBuilder::getOrCreateTypeArray(ArrayRef<Metadata *> Elements) {
 557   SmallVector<llvm::Metadata *, 16> Elts;
 558   for (unsigned i = 0, e = Elements.size(); i != e; ++i) {
 559     if (Elements[i] && isa<MDNode>(Elements[i]))
 560       Elts.push_back(cast<DIType>(Elements[i]));
 561     else
 562       Elts.push_back(Elements[i]);
 563   }
 564   return DITypeRefArray(MDNode::get(VMContext, Elts));
 565 }
 566
 567 DISubrange *DIBuilder::getOrCreateSubrange(int64_t Lo, int64_t Count) {
 568   return DISubrange::get(VMContext, Count, Lo);
 569 }
 570
 571 static void checkGlobalVariableScope(DIScope *Context) {
 572 #ifndef NDEBUG
 573   if (auto *CT =
 574           dyn_cast_or_null<DICompositeType>(getNonCompileUnitScope(Context)))
 575     assert(CT->getIdentifier().empty() &&
 576            "Context of a global variable should not be a type with identifier");
 577 #endif
 578 }
 579
 580 DIGlobalVariableExpression *DIBuilder::createGlobalVariableExpression(
 581     DIScope *Context, StringRef Name, StringRef LinkageName, DIFile *F,
 582     unsigned LineNumber, DIType *Ty, bool isLocalToUnit, DIExpression *Expr,
 583     MDNode *Decl, uint32_t AlignInBits) {
 584   checkGlobalVariableScope(Context);
 585
 586   auto *GV = DIGlobalVariable::getDistinct(
 587       VMContext, cast_or_null<DIScope>(Context), Name, LinkageName, F,
 588       LineNumber, Ty, isLocalToUnit, true, cast_or_null<DIDerivedType>(Decl),
 589       AlignInBits);
 590   auto *N = DIGlobalVariableExpression::get(VMContext, GV, Expr);
 591   AllGVs.push_back(N);
 592   return N;
 593 }
 594
 595 DIGlobalVariable *DIBuilder::createTempGlobalVariableFwdDecl(
 596     DIScope *Context, StringRef Name, StringRef LinkageName, DIFile *F,
 597     unsigned LineNumber, DIType *Ty, bool isLocalToUnit, MDNode *Decl,
 598     uint32_t AlignInBits) {
 599   checkGlobalVariableScope(Context);
 600
 601   return DIGlobalVariable::getTemporary(
 602              VMContext, cast_or_null<DIScope>(Context), Name, LinkageName, F,
 603              LineNumber, Ty, isLocalToUnit, false,
 604              cast_or_null<DIDerivedType>(Decl), AlignInBits)
 605       .release();
 606 }
 607
 608 static DILocalVariable *createLocalVariable(
 609     LLVMContext &VMContext,
 610     DenseMap<MDNode *, SmallVector<TrackingMDNodeRef, 1>> &PreservedVariables,
 611     DIScope *Scope, StringRef Name, unsigned ArgNo, DIFile *File,
 612     unsigned LineNo, DIType *Ty, bool AlwaysPreserve, DINode::DIFlags Flags,
 613     uint32_t AlignInBits) {
 614   // FIXME: Why getNonCompileUnitScope()?
 615   // FIXME: Why is "!Context" okay here?
 616   // FIXME: Why doesn't this check for a subprogram or lexical block (AFAICT
 617   // the only valid scopes)?
 618   DIScope *Context = getNonCompileUnitScope(Scope);
 619
 620   auto *Node =
 621       DILocalVariable::get(VMContext, cast_or_null<DILocalScope>(Context), Name,
 622                            File, LineNo, Ty, ArgNo, Flags, AlignInBits);
 623   if (AlwaysPreserve) {
 624     // The optimizer may remove local variables. If there is an interest
 625     // to preserve variable info in such situation then stash it in a
 626     // named mdnode.
 627     DISubprogram *Fn = getDISubprogram(Scope);
 628     assert(Fn && "Missing subprogram for local variable");
 629     PreservedVariables[Fn].emplace_back(Node);
 630   }
 631   return Node;
 632 }
 633
 634 DILocalVariable *DIBuilder::createAutoVariable(DIScope *Scope, StringRef Name,
 635                                                DIFile *File, unsigned LineNo,
 636                                                DIType *Ty, bool AlwaysPreserve,
 637                                                DINode::DIFlags Flags,
 638                                                uint32_t AlignInBits) {
 639   return createLocalVariable(VMContext, PreservedVariables, Scope, Name,
 640                              /* ArgNo */ 0, File, LineNo, Ty, AlwaysPreserve,
 641                              Flags, AlignInBits);
 642 }
 643
 644 DILocalVariable *DIBuilder::createParameterVariable(
 645     DIScope *Scope, StringRef Name, unsigned ArgNo, DIFile *File,
 646     unsigned LineNo, DIType *Ty, bool AlwaysPreserve, DINode::DIFlags Flags) {
 647   assert(ArgNo && "Expected non-zero argument number for parameter");
 648   return createLocalVariable(VMContext, PreservedVariables, Scope, Name, ArgNo,
 649                              File, LineNo, Ty, AlwaysPreserve, Flags,
 650                              /* AlignInBits */0);
 651 }
 652
 653 DIExpression *DIBuilder::createExpression(ArrayRef<uint64_t> Addr) {
 654   return DIExpression::get(VMContext, Addr);
 655 }
 656
 657 DIExpression *DIBuilder::createExpression(ArrayRef<int64_t> Signed) {
 658   // TODO: Remove the callers of this signed version and delete.
 659   SmallVector<uint64_t, 8> Addr(Signed.begin(), Signed.end());
 660   return createExpression(Addr);
 661 }
 662
 663 DIExpression *DIBuilder::createFragmentExpression(unsigned OffsetInBytes,
 664                                                   unsigned SizeInBytes) {
 665   uint64_t Addr[] = {dwarf::DW_OP_LLVM_fragment, OffsetInBytes, SizeInBytes};
 666   return DIExpression::get(VMContext, Addr);
 667 }
 668
 669 template <class... Ts>
 670 static DISubprogram *getSubprogram(bool IsDistinct, Ts &&... Args) {
 671   if (IsDistinct)
 672     return DISubprogram::getDistinct(std::forward<Ts>(Args)...);
 673   return DISubprogram::get(std::forward<Ts>(Args)...);
 674 }
 675
 676 DISubprogram *DIBuilder::createFunction(
 677     DIScope *Context, StringRef Name, StringRef LinkageName, DIFile *File,
 678     unsigned LineNo, DISubroutineType *Ty, bool isLocalToUnit,
 679     bool isDefinition, unsigned ScopeLine, DINode::DIFlags Flags,
 680     bool isOptimized, DITemplateParameterArray TParams, DISubprogram *Decl,
 681     DITypeArray ThrownTypes) {
 682   auto *Node = getSubprogram(
 683       /* IsDistinct = */ isDefinition, VMContext,
 684       getNonCompileUnitScope(Context), Name, LinkageName, File, LineNo, Ty,
 685       isLocalToUnit, isDefinition, ScopeLine, nullptr, 0, 0, 0, Flags,
 686       isOptimized, isDefinition ? CUNode : nullptr, TParams, Decl,
 687       MDTuple::getTemporary(VMContext, None).release(), ThrownTypes);
 688
 689   if (isDefinition)
 690     AllSubprograms.push_back(Node);
 691   trackIfUnresolved(Node);
 692   return Node;
 693 }
 694
 695 DISubprogram *DIBuilder::createTempFunctionFwdDecl(
 696     DIScope *Context, StringRef Name, StringRef LinkageName, DIFile *File,
 697     unsigned LineNo, DISubroutineType *Ty, bool isLocalToUnit,
 698     bool isDefinition, unsigned ScopeLine, DINode::DIFlags Flags,
 699     bool isOptimized, DITemplateParameterArray TParams, DISubprogram *Decl,
 700     DITypeArray ThrownTypes) {
 701   return DISubprogram::getTemporary(
 702              VMContext, getNonCompileUnitScope(Context), Name, LinkageName,
 703              File, LineNo, Ty, isLocalToUnit, isDefinition, ScopeLine, nullptr,
 704              0, 0, 0, Flags, isOptimized, isDefinition ? CUNode : nullptr,
 705              TParams, Decl, nullptr, ThrownTypes)
 706       .release();
 707 }
 708
 709 DISubprogram *DIBuilder::createMethod(
 710     DIScope *Context, StringRef Name, StringRef LinkageName, DIFile *F,
 711     unsigned LineNo, DISubroutineType *Ty, bool isLocalToUnit,
 712     bool isDefinition, unsigned VK, unsigned VIndex, int ThisAdjustment,
 713     DIType *VTableHolder, DINode::DIFlags Flags, bool isOptimized,
 714     DITemplateParameterArray TParams, DITypeArray ThrownTypes) {
 715   assert(getNonCompileUnitScope(Context) &&
 716          "Methods should have both a Context and a context that isn't "
 717          "the compile unit.");
 718   // FIXME: Do we want to use different scope/lines?
 719   auto *SP = getSubprogram(
 720       /* IsDistinct = */ isDefinition, VMContext, cast<DIScope>(Context), Name,
 721       LinkageName, F, LineNo, Ty, isLocalToUnit, isDefinition, LineNo,
 722       VTableHolder, VK, VIndex, ThisAdjustment, Flags, isOptimized,
 723       isDefinition ? CUNode : nullptr, TParams, nullptr, nullptr, ThrownTypes);
 724
 725   if (isDefinition)
 726     AllSubprograms.push_back(SP);
 727   trackIfUnresolved(SP);
 728   return SP;
 729 }
 730
 731 DINamespace *DIBuilder::createNameSpace(DIScope *Scope, StringRef Name,
 732                                         bool ExportSymbols) {
 733
 734   // It is okay to *not* make anonymous top-level namespaces distinct, because
 735   // all nodes that have an anonymous namespace as their parent scope are
 736   // guaranteed to be unique and/or are linked to their containing
 737   // DICompileUnit. This decision is an explicit tradeoff of link time versus
 738   // memory usage versus code simplicity and may get revisited in the future.
 739   return DINamespace::get(VMContext, getNonCompileUnitScope(Scope), Name,
 740                           ExportSymbols);
 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(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 }