llvm/lib/IR/DIBuilder.cpp

   1 //===--- DIBuilder.cpp - Debug Information Builder ------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file implements the DIBuilder.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "llvm/IR/DIBuilder.h"
  14 #include "LLVMContextImpl.h"
  15 #include "llvm/ADT/Optional.h"
  16 #include "llvm/ADT/STLExtras.h"
  17 #include "llvm/BinaryFormat/Dwarf.h"
  18 #include "llvm/IR/Constants.h"
  19 #include "llvm/IR/DebugInfo.h"
  20 #include "llvm/IR/IRBuilder.h"
  21 #include "llvm/IR/IntrinsicInst.h"
  22 #include "llvm/IR/Module.h"
  23 #include "llvm/Support/CommandLine.h"
  24 #include "llvm/Support/Debug.h"
  25
  26 using namespace llvm;
  27 using namespace llvm::dwarf;
  28
  29 static cl::opt<bool>
  30     UseDbgAddr("use-dbg-addr",
  31                llvm::cl::desc("Use llvm.dbg.addr for all local variables"),
  32                cl::init(false), cl::Hidden);
  33
  34 DIBuilder::DIBuilder(Module &m, bool AllowUnresolvedNodes, DICompileUnit *CU)
  35   : M(m), VMContext(M.getContext()), CUNode(CU),
  36       DeclareFn(nullptr), ValueFn(nullptr), LabelFn(nullptr),
  37       AllowUnresolvedNodes(AllowUnresolvedNodes) {}
  38
  39 void DIBuilder::trackIfUnresolved(MDNode *N) {
  40   if (!N)
  41     return;
  42   if (N->isResolved())
  43     return;
  44
  45   assert(AllowUnresolvedNodes && "Cannot handle unresolved nodes");
  46   UnresolvedNodes.emplace_back(N);
  47 }
  48
  49 void DIBuilder::finalizeSubprogram(DISubprogram *SP) {
  50   MDTuple *Temp = SP->getRetainedNodes().get();
  51   if (!Temp || !Temp->isTemporary())
  52     return;
  53
  54   SmallVector<Metadata *, 16> RetainedNodes;
  55
  56   auto PV = PreservedVariables.find(SP);
  57   if (PV != PreservedVariables.end())
  58     RetainedNodes.append(PV->second.begin(), PV->second.end());
  59
  60   auto PL = PreservedLabels.find(SP);
  61   if (PL != PreservedLabels.end())
  62     RetainedNodes.append(PL->second.begin(), PL->second.end());
  63
  64   DINodeArray Node = getOrCreateArray(RetainedNodes);
  65
  66   TempMDTuple(Temp)->replaceAllUsesWith(Node.get());
  67 }
  68
  69 void DIBuilder::finalize() {
  70   if (!CUNode) {
  71     assert(!AllowUnresolvedNodes &&
  72            "creating type nodes without a CU is not supported");
  73     return;
  74   }
  75
  76   CUNode->replaceEnumTypes(MDTuple::get(VMContext, AllEnumTypes));
  77
  78   SmallVector<Metadata *, 16> RetainValues;
  79   // Declarations and definitions of the same type may be retained. Some
  80   // clients RAUW these pairs, leaving duplicates in the retained types
  81   // list. Use a set to remove the duplicates while we transform the
  82   // TrackingVHs back into Values.
  83   SmallPtrSet<Metadata *, 16> RetainSet;
  84   for (unsigned I = 0, E = AllRetainTypes.size(); I < E; I++)
  85     if (RetainSet.insert(AllRetainTypes[I]).second)
  86       RetainValues.push_back(AllRetainTypes[I]);
  87
  88   if (!RetainValues.empty())
  89     CUNode->replaceRetainedTypes(MDTuple::get(VMContext, RetainValues));
  90
  91   DISubprogramArray SPs = MDTuple::get(VMContext, AllSubprograms);
  92   for (auto *SP : SPs)
  93     finalizeSubprogram(SP);
  94   for (auto *N : RetainValues)
  95     if (auto *SP = dyn_cast<DISubprogram>(N))
  96       finalizeSubprogram(SP);
  97
  98   if (!AllGVs.empty())
  99     CUNode->replaceGlobalVariables(MDTuple::get(VMContext, AllGVs));
 100
 101   if (!AllImportedModules.empty())
 102     CUNode->replaceImportedEntities(MDTuple::get(
 103         VMContext, SmallVector<Metadata *, 16>(AllImportedModules.begin(),
 104                                                AllImportedModules.end())));
 105
 106   for (const auto &I : AllMacrosPerParent) {
 107     // DIMacroNode's with nullptr parent are DICompileUnit direct children.
 108     if (!I.first) {
 109       CUNode->replaceMacros(MDTuple::get(VMContext, I.second.getArrayRef()));
 110       continue;
 111     }
 112     // Otherwise, it must be a temporary DIMacroFile that need to be resolved.
 113     auto *TMF = cast<DIMacroFile>(I.first);
 114     auto *MF = DIMacroFile::get(VMContext, dwarf::DW_MACINFO_start_file,
 115                                 TMF->getLine(), TMF->getFile(),
 116                                 getOrCreateMacroArray(I.second.getArrayRef()));
 117     replaceTemporary(llvm::TempDIMacroNode(TMF), MF);
 118   }
 119
 120   // Now that all temp nodes have been replaced or deleted, resolve remaining
 121   // cycles.
 122   for (const auto &N : UnresolvedNodes)
 123     if (N && !N->isResolved())
 124       N->resolveCycles();
 125   UnresolvedNodes.clear();
 126
 127   // Can't handle unresolved nodes anymore.
 128   AllowUnresolvedNodes = false;
 129 }
 130
 131 /// If N is compile unit return NULL otherwise return N.
 132 static DIScope *getNonCompileUnitScope(DIScope *N) {
 133   if (!N || isa<DICompileUnit>(N))
 134     return nullptr;
 135   return cast<DIScope>(N);
 136 }
 137
 138 DICompileUnit *DIBuilder::createCompileUnit(
 139     unsigned Lang, DIFile *File, StringRef Producer, bool isOptimized,
 140     StringRef Flags, unsigned RunTimeVer, StringRef SplitName,
 141     DICompileUnit::DebugEmissionKind Kind, uint64_t DWOId,
 142     bool SplitDebugInlining, bool DebugInfoForProfiling,
 143     DICompileUnit::DebugNameTableKind NameTableKind, bool RangesBaseAddress,
 144     StringRef SysRoot, StringRef SDK) {
 145
 146   assert(((Lang <= dwarf::DW_LANG_Fortran08 && Lang >= dwarf::DW_LANG_C89) ||
 147           (Lang <= dwarf::DW_LANG_hi_user && Lang >= dwarf::DW_LANG_lo_user)) &&
 148          "Invalid Language tag");
 149
 150   assert(!CUNode && "Can only make one compile unit per DIBuilder instance");
 151   CUNode = DICompileUnit::getDistinct(
 152       VMContext, Lang, File, Producer, isOptimized, Flags, RunTimeVer,
 153       SplitName, Kind, nullptr, nullptr, nullptr, nullptr, nullptr, DWOId,
 154       SplitDebugInlining, DebugInfoForProfiling, NameTableKind,
 155       RangesBaseAddress, SysRoot, SDK);
 156
 157   // Create a named metadata so that it is easier to find cu in a module.
 158   NamedMDNode *NMD = M.getOrInsertNamedMetadata("llvm.dbg.cu");
 159   NMD->addOperand(CUNode);
 160   trackIfUnresolved(CUNode);
 161   return CUNode;
 162 }
 163
 164 static DIImportedEntity *
 165 createImportedModule(LLVMContext &C, dwarf::Tag Tag, DIScope *Context,
 166                      Metadata *NS, DIFile *File, unsigned Line, StringRef Name,
 167                      SmallVectorImpl<TrackingMDNodeRef> &AllImportedModules) {
 168   if (Line)
 169     assert(File && "Source location has line number but no file");
 170   unsigned EntitiesCount = C.pImpl->DIImportedEntitys.size();
 171   auto *M = DIImportedEntity::get(C, Tag, Context, cast_or_null<DINode>(NS),
 172                                   File, Line, Name);
 173   if (EntitiesCount < C.pImpl->DIImportedEntitys.size())
 174     // A new Imported Entity was just added to the context.
 175     // Add it to the Imported Modules list.
 176     AllImportedModules.emplace_back(M);
 177   return M;
 178 }
 179
 180 DIImportedEntity *DIBuilder::createImportedModule(DIScope *Context,
 181                                                   DINamespace *NS, DIFile *File,
 182                                                   unsigned Line) {
 183   return ::createImportedModule(VMContext, dwarf::DW_TAG_imported_module,
 184                                 Context, NS, File, Line, StringRef(),
 185                                 AllImportedModules);
 186 }
 187
 188 DIImportedEntity *DIBuilder::createImportedModule(DIScope *Context,
 189                                                   DIImportedEntity *NS,
 190                                                   DIFile *File, unsigned Line) {
 191   return ::createImportedModule(VMContext, dwarf::DW_TAG_imported_module,
 192                                 Context, NS, File, Line, StringRef(),
 193                                 AllImportedModules);
 194 }
 195
 196 DIImportedEntity *DIBuilder::createImportedModule(DIScope *Context, DIModule *M,
 197                                                   DIFile *File, unsigned Line) {
 198   return ::createImportedModule(VMContext, dwarf::DW_TAG_imported_module,
 199                                 Context, M, File, Line, StringRef(),
 200                                 AllImportedModules);
 201 }
 202
 203 DIImportedEntity *DIBuilder::createImportedDeclaration(DIScope *Context,
 204                                                        DINode *Decl,
 205                                                        DIFile *File,
 206                                                        unsigned Line,
 207                                                        StringRef Name) {
 208   // Make sure to use the unique identifier based metadata reference for
 209   // types that have one.
 210   return ::createImportedModule(VMContext, dwarf::DW_TAG_imported_declaration,
 211                                 Context, Decl, File, Line, Name,
 212                                 AllImportedModules);
 213 }
 214
 215 DIFile *DIBuilder::createFile(StringRef Filename, StringRef Directory,
 216                               Optional<DIFile::ChecksumInfo<StringRef>> CS,
 217                               Optional<StringRef> Source) {
 218   return DIFile::get(VMContext, Filename, Directory, CS, Source);
 219 }
 220
 221 DIMacro *DIBuilder::createMacro(DIMacroFile *Parent, unsigned LineNumber,
 222                                 unsigned MacroType, StringRef Name,
 223                                 StringRef Value) {
 224   assert(!Name.empty() && "Unable to create macro without name");
 225   assert((MacroType == dwarf::DW_MACINFO_undef ||
 226           MacroType == dwarf::DW_MACINFO_define) &&
 227          "Unexpected macro type");
 228   auto *M = DIMacro::get(VMContext, MacroType, LineNumber, Name, Value);
 229   AllMacrosPerParent[Parent].insert(M);
 230   return M;
 231 }
 232
 233 DIMacroFile *DIBuilder::createTempMacroFile(DIMacroFile *Parent,
 234                                             unsigned LineNumber, DIFile *File) {
 235   auto *MF = DIMacroFile::getTemporary(VMContext, dwarf::DW_MACINFO_start_file,
 236                                        LineNumber, File, DIMacroNodeArray())
 237                  .release();
 238   AllMacrosPerParent[Parent].insert(MF);
 239   // Add the new temporary DIMacroFile to the macro per parent map as a parent.
 240   // This is needed to assure DIMacroFile with no children to have an entry in
 241   // the map. Otherwise, it will not be resolved in DIBuilder::finalize().
 242   AllMacrosPerParent.insert({MF, {}});
 243   return MF;
 244 }
 245
 246 DIEnumerator *DIBuilder::createEnumerator(StringRef Name, uint64_t Val,
 247                                           bool IsUnsigned) {
 248   assert(!Name.empty() && "Unable to create enumerator without name");
 249   return DIEnumerator::get(VMContext, APInt(64, Val, !IsUnsigned), IsUnsigned,
 250                            Name);
 251 }
 252
 253 DIEnumerator *DIBuilder::createEnumerator(StringRef Name, APSInt Value) {
 254   assert(!Name.empty() && "Unable to create enumerator without name");
 255   return DIEnumerator::get(VMContext, APInt(Value), Value.isUnsigned(), Name);
 256 }
 257
 258 DIBasicType *DIBuilder::createUnspecifiedType(StringRef Name) {
 259   assert(!Name.empty() && "Unable to create type without name");
 260   return DIBasicType::get(VMContext, dwarf::DW_TAG_unspecified_type, Name);
 261 }
 262
 263 DIBasicType *DIBuilder::createNullPtrType() {
 264   return createUnspecifiedType("decltype(nullptr)");
 265 }
 266
 267 DIBasicType *DIBuilder::createBasicType(StringRef Name, uint64_t SizeInBits,
 268                                         unsigned Encoding,
 269                                         DINode::DIFlags Flags) {
 270   assert(!Name.empty() && "Unable to create type without name");
 271   return DIBasicType::get(VMContext, dwarf::DW_TAG_base_type, Name, SizeInBits,
 272                           0, Encoding, Flags);
 273 }
 274
 275 DIStringType *DIBuilder::createStringType(StringRef Name, uint64_t SizeInBits) {
 276   assert(!Name.empty() && "Unable to create type without name");
 277   return DIStringType::get(VMContext, dwarf::DW_TAG_string_type, Name,
 278                            SizeInBits, 0);
 279 }
 280
 281 DIDerivedType *DIBuilder::createQualifiedType(unsigned Tag, DIType *FromTy) {
 282   return DIDerivedType::get(VMContext, Tag, "", nullptr, 0, nullptr, FromTy, 0,
 283                             0, 0, None, DINode::FlagZero);
 284 }
 285
 286 DIDerivedType *DIBuilder::createPointerType(
 287     DIType *PointeeTy,
 288     uint64_t SizeInBits,
 289     uint32_t AlignInBits,
 290     Optional<unsigned> DWARFAddressSpace,
 291     StringRef Name) {
 292   // FIXME: Why is there a name here?
 293   return DIDerivedType::get(VMContext, dwarf::DW_TAG_pointer_type, Name,
 294                             nullptr, 0, nullptr, PointeeTy, SizeInBits,
 295                             AlignInBits, 0, DWARFAddressSpace,
 296                             DINode::FlagZero);
 297 }
 298
 299 DIDerivedType *DIBuilder::createMemberPointerType(DIType *PointeeTy,
 300                                                   DIType *Base,
 301                                                   uint64_t SizeInBits,
 302                                                   uint32_t AlignInBits,
 303                                                   DINode::DIFlags Flags) {
 304   return DIDerivedType::get(VMContext, dwarf::DW_TAG_ptr_to_member_type, "",
 305                             nullptr, 0, nullptr, PointeeTy, SizeInBits,
 306                             AlignInBits, 0, None, Flags, Base);
 307 }
 308
 309 DIDerivedType *DIBuilder::createReferenceType(
 310     unsigned Tag, DIType *RTy,
 311     uint64_t SizeInBits,
 312     uint32_t AlignInBits,
 313     Optional<unsigned> DWARFAddressSpace) {
 314   assert(RTy && "Unable to create reference type");
 315   return DIDerivedType::get(VMContext, Tag, "", nullptr, 0, nullptr, RTy,
 316                             SizeInBits, AlignInBits, 0, DWARFAddressSpace,
 317                             DINode::FlagZero);
 318 }
 319
 320 DIDerivedType *DIBuilder::createTypedef(DIType *Ty, StringRef Name,
 321                                         DIFile *File, unsigned LineNo,
 322                                         DIScope *Context,
 323                                         uint32_t AlignInBits) {
 324   return DIDerivedType::get(VMContext, dwarf::DW_TAG_typedef, Name, File,
 325                             LineNo, getNonCompileUnitScope(Context), Ty, 0,
 326                             AlignInBits, 0, None, DINode::FlagZero);
 327 }
 328
 329 DIDerivedType *DIBuilder::createFriend(DIType *Ty, DIType *FriendTy) {
 330   assert(Ty && "Invalid type!");
 331   assert(FriendTy && "Invalid friend type!");
 332   return DIDerivedType::get(VMContext, dwarf::DW_TAG_friend, "", nullptr, 0, Ty,
 333                             FriendTy, 0, 0, 0, None, DINode::FlagZero);
 334 }
 335
 336 DIDerivedType *DIBuilder::createInheritance(DIType *Ty, DIType *BaseTy,
 337                                             uint64_t BaseOffset,
 338                                             uint32_t VBPtrOffset,
 339                                             DINode::DIFlags Flags) {
 340   assert(Ty && "Unable to create inheritance");
 341   Metadata *ExtraData = ConstantAsMetadata::get(
 342       ConstantInt::get(IntegerType::get(VMContext, 32), VBPtrOffset));
 343   return DIDerivedType::get(VMContext, dwarf::DW_TAG_inheritance, "", nullptr,
 344                             0, Ty, BaseTy, 0, 0, BaseOffset, None,
 345                             Flags, ExtraData);
 346 }
 347
 348 DIDerivedType *DIBuilder::createMemberType(
 349     DIScope *Scope, StringRef Name, DIFile *File, unsigned LineNumber,
 350     uint64_t SizeInBits, uint32_t AlignInBits, uint64_t OffsetInBits,
 351     DINode::DIFlags Flags, DIType *Ty, DINodeArray Annotations) {
 352   return DIDerivedType::get(VMContext, dwarf::DW_TAG_member, Name, File,
 353                             LineNumber, getNonCompileUnitScope(Scope), Ty,
 354                             SizeInBits, AlignInBits, OffsetInBits, None, Flags,
 355                             nullptr, Annotations);
 356 }
 357
 358 static ConstantAsMetadata *getConstantOrNull(Constant *C) {
 359   if (C)
 360     return ConstantAsMetadata::get(C);
 361   return nullptr;
 362 }
 363
 364 DIDerivedType *DIBuilder::createVariantMemberType(
 365     DIScope *Scope, StringRef Name, DIFile *File, unsigned LineNumber,
 366     uint64_t SizeInBits, uint32_t AlignInBits, uint64_t OffsetInBits,
 367     Constant *Discriminant, DINode::DIFlags Flags, DIType *Ty) {
 368   return DIDerivedType::get(VMContext, dwarf::DW_TAG_member, Name, File,
 369                             LineNumber, getNonCompileUnitScope(Scope), Ty,
 370                             SizeInBits, AlignInBits, OffsetInBits, None, Flags,
 371                             getConstantOrNull(Discriminant));
 372 }
 373
 374 DIDerivedType *DIBuilder::createBitFieldMemberType(
 375     DIScope *Scope, StringRef Name, DIFile *File, unsigned LineNumber,
 376     uint64_t SizeInBits, uint64_t OffsetInBits, uint64_t StorageOffsetInBits,
 377     DINode::DIFlags Flags, DIType *Ty, DINodeArray Annotations) {
 378   Flags |= DINode::FlagBitField;
 379   return DIDerivedType::get(
 380       VMContext, dwarf::DW_TAG_member, Name, File, LineNumber,
 381       getNonCompileUnitScope(Scope), Ty, SizeInBits, /* AlignInBits */ 0,
 382       OffsetInBits, None, Flags,
 383       ConstantAsMetadata::get(ConstantInt::get(IntegerType::get(VMContext, 64),
 384                                                StorageOffsetInBits)),
 385       Annotations);
 386 }
 387
 388 DIDerivedType *
 389 DIBuilder::createStaticMemberType(DIScope *Scope, StringRef Name, DIFile *File,
 390                                   unsigned LineNumber, DIType *Ty,
 391                                   DINode::DIFlags Flags, llvm::Constant *Val,
 392                                   uint32_t AlignInBits) {
 393   Flags |= DINode::FlagStaticMember;
 394   return DIDerivedType::get(VMContext, dwarf::DW_TAG_member, Name, File,
 395                             LineNumber, getNonCompileUnitScope(Scope), Ty, 0,
 396                             AlignInBits, 0, None, Flags,
 397                             getConstantOrNull(Val));
 398 }
 399
 400 DIDerivedType *
 401 DIBuilder::createObjCIVar(StringRef Name, DIFile *File, unsigned LineNumber,
 402                           uint64_t SizeInBits, uint32_t AlignInBits,
 403                           uint64_t OffsetInBits, DINode::DIFlags Flags,
 404                           DIType *Ty, MDNode *PropertyNode) {
 405   return DIDerivedType::get(VMContext, dwarf::DW_TAG_member, Name, File,
 406                             LineNumber, getNonCompileUnitScope(File), Ty,
 407                             SizeInBits, AlignInBits, OffsetInBits, None, Flags,
 408                             PropertyNode);
 409 }
 410
 411 DIObjCProperty *
 412 DIBuilder::createObjCProperty(StringRef Name, DIFile *File, unsigned LineNumber,
 413                               StringRef GetterName, StringRef SetterName,
 414                               unsigned PropertyAttributes, DIType *Ty) {
 415   return DIObjCProperty::get(VMContext, Name, File, LineNumber, GetterName,
 416                              SetterName, PropertyAttributes, Ty);
 417 }
 418
 419 DITemplateTypeParameter *
 420 DIBuilder::createTemplateTypeParameter(DIScope *Context, StringRef Name,
 421                                        DIType *Ty, bool isDefault) {
 422   assert((!Context || isa<DICompileUnit>(Context)) && "Expected compile unit");
 423   return DITemplateTypeParameter::get(VMContext, Name, Ty, isDefault);
 424 }
 425
 426 static DITemplateValueParameter *
 427 createTemplateValueParameterHelper(LLVMContext &VMContext, unsigned Tag,
 428                                    DIScope *Context, StringRef Name, DIType *Ty,
 429                                    bool IsDefault, Metadata *MD) {
 430   assert((!Context || isa<DICompileUnit>(Context)) && "Expected compile unit");
 431   return DITemplateValueParameter::get(VMContext, Tag, Name, Ty, IsDefault, MD);
 432 }
 433
 434 DITemplateValueParameter *
 435 DIBuilder::createTemplateValueParameter(DIScope *Context, StringRef Name,
 436                                         DIType *Ty, bool isDefault,
 437                                         Constant *Val) {
 438   return createTemplateValueParameterHelper(
 439       VMContext, dwarf::DW_TAG_template_value_parameter, Context, Name, Ty,
 440       isDefault, getConstantOrNull(Val));
 441 }
 442
 443 DITemplateValueParameter *
 444 DIBuilder::createTemplateTemplateParameter(DIScope *Context, StringRef Name,
 445                                            DIType *Ty, StringRef Val) {
 446   return createTemplateValueParameterHelper(
 447       VMContext, dwarf::DW_TAG_GNU_template_template_param, Context, Name, Ty,
 448       false, MDString::get(VMContext, Val));
 449 }
 450
 451 DITemplateValueParameter *
 452 DIBuilder::createTemplateParameterPack(DIScope *Context, StringRef Name,
 453                                        DIType *Ty, DINodeArray Val) {
 454   return createTemplateValueParameterHelper(
 455       VMContext, dwarf::DW_TAG_GNU_template_parameter_pack, Context, Name, Ty,
 456       false, Val.get());
 457 }
 458
 459 DICompositeType *DIBuilder::createClassType(
 460     DIScope *Context, StringRef Name, DIFile *File, unsigned LineNumber,
 461     uint64_t SizeInBits, uint32_t AlignInBits, uint64_t OffsetInBits,
 462     DINode::DIFlags Flags, DIType *DerivedFrom, DINodeArray Elements,
 463     DIType *VTableHolder, MDNode *TemplateParams, StringRef UniqueIdentifier) {
 464   assert((!Context || isa<DIScope>(Context)) &&
 465          "createClassType should be called with a valid Context");
 466
 467   auto *R = DICompositeType::get(
 468       VMContext, dwarf::DW_TAG_structure_type, Name, File, LineNumber,
 469       getNonCompileUnitScope(Context), DerivedFrom, SizeInBits, AlignInBits,
 470       OffsetInBits, Flags, Elements, 0, VTableHolder,
 471       cast_or_null<MDTuple>(TemplateParams), UniqueIdentifier);
 472   trackIfUnresolved(R);
 473   return R;
 474 }
 475
 476 DICompositeType *DIBuilder::createStructType(
 477     DIScope *Context, StringRef Name, DIFile *File, unsigned LineNumber,
 478     uint64_t SizeInBits, uint32_t AlignInBits, DINode::DIFlags Flags,
 479     DIType *DerivedFrom, DINodeArray Elements, unsigned RunTimeLang,
 480     DIType *VTableHolder, StringRef UniqueIdentifier) {
 481   auto *R = DICompositeType::get(
 482       VMContext, dwarf::DW_TAG_structure_type, Name, File, LineNumber,
 483       getNonCompileUnitScope(Context), DerivedFrom, SizeInBits, AlignInBits, 0,
 484       Flags, Elements, RunTimeLang, VTableHolder, nullptr, UniqueIdentifier);
 485   trackIfUnresolved(R);
 486   return R;
 487 }
 488
 489 DICompositeType *DIBuilder::createUnionType(
 490     DIScope *Scope, StringRef Name, DIFile *File, unsigned LineNumber,
 491     uint64_t SizeInBits, uint32_t AlignInBits, DINode::DIFlags Flags,
 492     DINodeArray Elements, unsigned RunTimeLang, StringRef UniqueIdentifier) {
 493   auto *R = DICompositeType::get(
 494       VMContext, dwarf::DW_TAG_union_type, Name, File, LineNumber,
 495       getNonCompileUnitScope(Scope), nullptr, SizeInBits, AlignInBits, 0, Flags,
 496       Elements, RunTimeLang, nullptr, nullptr, UniqueIdentifier);
 497   trackIfUnresolved(R);
 498   return R;
 499 }
 500
 501 DICompositeType *DIBuilder::createVariantPart(
 502     DIScope *Scope, StringRef Name, DIFile *File, unsigned LineNumber,
 503     uint64_t SizeInBits, uint32_t AlignInBits, DINode::DIFlags Flags,
 504     DIDerivedType *Discriminator, DINodeArray Elements, StringRef UniqueIdentifier) {
 505   auto *R = DICompositeType::get(
 506       VMContext, dwarf::DW_TAG_variant_part, Name, File, LineNumber,
 507       getNonCompileUnitScope(Scope), nullptr, SizeInBits, AlignInBits, 0, Flags,
 508       Elements, 0, nullptr, nullptr, UniqueIdentifier, Discriminator);
 509   trackIfUnresolved(R);
 510   return R;
 511 }
 512
 513 DISubroutineType *DIBuilder::createSubroutineType(DITypeRefArray ParameterTypes,
 514                                                   DINode::DIFlags Flags,
 515                                                   unsigned CC) {
 516   return DISubroutineType::get(VMContext, Flags, CC, ParameterTypes);
 517 }
 518
 519 DICompositeType *DIBuilder::createEnumerationType(
 520     DIScope *Scope, StringRef Name, DIFile *File, unsigned LineNumber,
 521     uint64_t SizeInBits, uint32_t AlignInBits, DINodeArray Elements,
 522     DIType *UnderlyingType, StringRef UniqueIdentifier, bool IsScoped) {
 523   auto *CTy = DICompositeType::get(
 524       VMContext, dwarf::DW_TAG_enumeration_type, Name, File, LineNumber,
 525       getNonCompileUnitScope(Scope), UnderlyingType, SizeInBits, AlignInBits, 0,
 526       IsScoped ? DINode::FlagEnumClass : DINode::FlagZero, Elements, 0, nullptr,
 527       nullptr, UniqueIdentifier);
 528   AllEnumTypes.push_back(CTy);
 529   trackIfUnresolved(CTy);
 530   return CTy;
 531 }
 532
 533 DIDerivedType *DIBuilder::createSetType(DIScope *Scope, StringRef Name,
 534                                         DIFile *File, unsigned LineNo,
 535                                         uint64_t SizeInBits,
 536                                         uint32_t AlignInBits, DIType *Ty) {
 537   auto *R =
 538       DIDerivedType::get(VMContext, dwarf::DW_TAG_set_type, Name, File, LineNo,
 539                          getNonCompileUnitScope(Scope), Ty, SizeInBits,
 540                          AlignInBits, 0, None, DINode::FlagZero);
 541   trackIfUnresolved(R);
 542   return R;
 543 }
 544
 545 DICompositeType *DIBuilder::createArrayType(
 546     uint64_t Size, uint32_t AlignInBits, DIType *Ty, DINodeArray Subscripts,
 547     PointerUnion<DIExpression *, DIVariable *> DL,
 548     PointerUnion<DIExpression *, DIVariable *> AS,
 549     PointerUnion<DIExpression *, DIVariable *> AL,
 550     PointerUnion<DIExpression *, DIVariable *> RK) {
 551   auto *R = DICompositeType::get(
 552       VMContext, dwarf::DW_TAG_array_type, "", nullptr, 0,
 553       nullptr, Ty, Size, AlignInBits, 0, DINode::FlagZero,
 554       Subscripts, 0, nullptr, nullptr, "", nullptr,
 555       DL.is<DIExpression *>() ? (Metadata *)DL.get<DIExpression *>()
 556                               : (Metadata *)DL.get<DIVariable *>(),
 557       AS.is<DIExpression *>() ? (Metadata *)AS.get<DIExpression *>()
 558                               : (Metadata *)AS.get<DIVariable *>(),
 559       AL.is<DIExpression *>() ? (Metadata *)AL.get<DIExpression *>()
 560                               : (Metadata *)AL.get<DIVariable *>(),
 561       RK.is<DIExpression *>() ? (Metadata *)RK.get<DIExpression *>()
 562                               : (Metadata *)RK.get<DIVariable *>());
 563   trackIfUnresolved(R);
 564   return R;
 565 }
 566
 567 DICompositeType *DIBuilder::createVectorType(uint64_t Size,
 568                                              uint32_t AlignInBits, DIType *Ty,
 569                                              DINodeArray Subscripts) {
 570   auto *R = DICompositeType::get(VMContext, dwarf::DW_TAG_array_type, "",
 571                                  nullptr, 0, nullptr, Ty, Size, AlignInBits, 0,
 572                                  DINode::FlagVector, Subscripts, 0, nullptr);
 573   trackIfUnresolved(R);
 574   return R;
 575 }
 576
 577 DISubprogram *DIBuilder::createArtificialSubprogram(DISubprogram *SP) {
 578   auto NewSP = SP->cloneWithFlags(SP->getFlags() | DINode::FlagArtificial);
 579   return MDNode::replaceWithDistinct(std::move(NewSP));
 580 }
 581
 582 static DIType *createTypeWithFlags(const DIType *Ty,
 583                                    DINode::DIFlags FlagsToSet) {
 584   auto NewTy = Ty->cloneWithFlags(Ty->getFlags() | FlagsToSet);
 585   return MDNode::replaceWithUniqued(std::move(NewTy));
 586 }
 587
 588 DIType *DIBuilder::createArtificialType(DIType *Ty) {
 589   // FIXME: Restrict this to the nodes where it's valid.
 590   if (Ty->isArtificial())
 591     return Ty;
 592   return createTypeWithFlags(Ty, DINode::FlagArtificial);
 593 }
 594
 595 DIType *DIBuilder::createObjectPointerType(DIType *Ty) {
 596   // FIXME: Restrict this to the nodes where it's valid.
 597   if (Ty->isObjectPointer())
 598     return Ty;
 599   DINode::DIFlags Flags = DINode::FlagObjectPointer | DINode::FlagArtificial;
 600   return createTypeWithFlags(Ty, Flags);
 601 }
 602
 603 void DIBuilder::retainType(DIScope *T) {
 604   assert(T && "Expected non-null type");
 605   assert((isa<DIType>(T) || (isa<DISubprogram>(T) &&
 606                              cast<DISubprogram>(T)->isDefinition() == false)) &&
 607          "Expected type or subprogram declaration");
 608   AllRetainTypes.emplace_back(T);
 609 }
 610
 611 DIBasicType *DIBuilder::createUnspecifiedParameter() { return nullptr; }
 612
 613 DICompositeType *
 614 DIBuilder::createForwardDecl(unsigned Tag, StringRef Name, DIScope *Scope,
 615                              DIFile *F, unsigned Line, unsigned RuntimeLang,
 616                              uint64_t SizeInBits, uint32_t AlignInBits,
 617                              StringRef UniqueIdentifier) {
 618   // FIXME: Define in terms of createReplaceableForwardDecl() by calling
 619   // replaceWithUniqued().
 620   auto *RetTy = DICompositeType::get(
 621       VMContext, Tag, Name, F, Line, getNonCompileUnitScope(Scope), nullptr,
 622       SizeInBits, AlignInBits, 0, DINode::FlagFwdDecl, nullptr, RuntimeLang,
 623       nullptr, nullptr, UniqueIdentifier);
 624   trackIfUnresolved(RetTy);
 625   return RetTy;
 626 }
 627
 628 DICompositeType *DIBuilder::createReplaceableCompositeType(
 629     unsigned Tag, StringRef Name, DIScope *Scope, DIFile *F, unsigned Line,
 630     unsigned RuntimeLang, uint64_t SizeInBits, uint32_t AlignInBits,
 631     DINode::DIFlags Flags, StringRef UniqueIdentifier,
 632     DINodeArray Annotations) {
 633   auto *RetTy =
 634       DICompositeType::getTemporary(
 635           VMContext, Tag, Name, F, Line, getNonCompileUnitScope(Scope), nullptr,
 636           SizeInBits, AlignInBits, 0, Flags, nullptr, RuntimeLang, nullptr,
 637           nullptr, UniqueIdentifier, nullptr, nullptr, nullptr, nullptr, nullptr,
 638           Annotations)
 639           .release();
 640   trackIfUnresolved(RetTy);
 641   return RetTy;
 642 }
 643
 644 DINodeArray DIBuilder::getOrCreateArray(ArrayRef<Metadata *> Elements) {
 645   return MDTuple::get(VMContext, Elements);
 646 }
 647
 648 DIMacroNodeArray
 649 DIBuilder::getOrCreateMacroArray(ArrayRef<Metadata *> Elements) {
 650   return MDTuple::get(VMContext, Elements);
 651 }
 652
 653 DITypeRefArray DIBuilder::getOrCreateTypeArray(ArrayRef<Metadata *> Elements) {
 654   SmallVector<llvm::Metadata *, 16> Elts;
 655   for (unsigned i = 0, e = Elements.size(); i != e; ++i) {
 656     if (Elements[i] && isa<MDNode>(Elements[i]))
 657       Elts.push_back(cast<DIType>(Elements[i]));
 658     else
 659       Elts.push_back(Elements[i]);
 660   }
 661   return DITypeRefArray(MDNode::get(VMContext, Elts));
 662 }
 663
 664 DISubrange *DIBuilder::getOrCreateSubrange(int64_t Lo, int64_t Count) {
 665   auto *LB = ConstantAsMetadata::get(
 666       ConstantInt::getSigned(Type::getInt64Ty(VMContext), Lo));
 667   auto *CountNode = ConstantAsMetadata::get(
 668       ConstantInt::getSigned(Type::getInt64Ty(VMContext), Count));
 669   return DISubrange::get(VMContext, CountNode, LB, nullptr, nullptr);
 670 }
 671
 672 DISubrange *DIBuilder::getOrCreateSubrange(int64_t Lo, Metadata *CountNode) {
 673   auto *LB = ConstantAsMetadata::get(
 674       ConstantInt::getSigned(Type::getInt64Ty(VMContext), Lo));
 675   return DISubrange::get(VMContext, CountNode, LB, nullptr, nullptr);
 676 }
 677
 678 DISubrange *DIBuilder::getOrCreateSubrange(Metadata *CountNode, Metadata *LB,
 679                                            Metadata *UB, Metadata *Stride) {
 680   return DISubrange::get(VMContext, CountNode, LB, UB, Stride);
 681 }
 682
 683 DIGenericSubrange *DIBuilder::getOrCreateGenericSubrange(
 684     DIGenericSubrange::BoundType CountNode, DIGenericSubrange::BoundType LB,
 685     DIGenericSubrange::BoundType UB, DIGenericSubrange::BoundType Stride) {
 686   auto ConvToMetadata = [&](DIGenericSubrange::BoundType Bound) -> Metadata * {
 687     return Bound.is<DIExpression *>() ? (Metadata *)Bound.get<DIExpression *>()
 688                                       : (Metadata *)Bound.get<DIVariable *>();
 689   };
 690   return DIGenericSubrange::get(VMContext, ConvToMetadata(CountNode),
 691                                 ConvToMetadata(LB), ConvToMetadata(UB),
 692                                 ConvToMetadata(Stride));
 693 }
 694
 695 static void checkGlobalVariableScope(DIScope *Context) {
 696 #ifndef NDEBUG
 697   if (auto *CT =
 698           dyn_cast_or_null<DICompositeType>(getNonCompileUnitScope(Context)))
 699     assert(CT->getIdentifier().empty() &&
 700            "Context of a global variable should not be a type with identifier");
 701 #endif
 702 }
 703
 704 DIGlobalVariableExpression *DIBuilder::createGlobalVariableExpression(
 705     DIScope *Context, StringRef Name, StringRef LinkageName, DIFile *F,
 706     unsigned LineNumber, DIType *Ty, bool IsLocalToUnit,
 707     bool isDefined, DIExpression *Expr,
 708     MDNode *Decl, MDTuple *TemplateParams, uint32_t AlignInBits) {
 709   checkGlobalVariableScope(Context);
 710
 711   auto *GV = DIGlobalVariable::getDistinct(
 712       VMContext, cast_or_null<DIScope>(Context), Name, LinkageName, F,
 713       LineNumber, Ty, IsLocalToUnit, isDefined, cast_or_null<DIDerivedType>(Decl),
 714       TemplateParams, AlignInBits);
 715   if (!Expr)
 716     Expr = createExpression();
 717   auto *N = DIGlobalVariableExpression::get(VMContext, GV, Expr);
 718   AllGVs.push_back(N);
 719   return N;
 720 }
 721
 722 DIGlobalVariable *DIBuilder::createTempGlobalVariableFwdDecl(
 723     DIScope *Context, StringRef Name, StringRef LinkageName, DIFile *F,
 724     unsigned LineNumber, DIType *Ty, bool IsLocalToUnit, MDNode *Decl,
 725     MDTuple *TemplateParams, uint32_t AlignInBits) {
 726   checkGlobalVariableScope(Context);
 727
 728   return DIGlobalVariable::getTemporary(
 729              VMContext, cast_or_null<DIScope>(Context), Name, LinkageName, F,
 730              LineNumber, Ty, IsLocalToUnit, false,
 731              cast_or_null<DIDerivedType>(Decl), TemplateParams, AlignInBits)
 732       .release();
 733 }
 734
 735 static DILocalVariable *createLocalVariable(
 736     LLVMContext &VMContext,
 737     DenseMap<MDNode *, SmallVector<TrackingMDNodeRef, 1>> &PreservedVariables,
 738     DIScope *Scope, StringRef Name, unsigned ArgNo, DIFile *File,
 739     unsigned LineNo, DIType *Ty, bool AlwaysPreserve, DINode::DIFlags Flags,
 740     uint32_t AlignInBits) {
 741   // FIXME: Why getNonCompileUnitScope()?
 742   // FIXME: Why is "!Context" okay here?
 743   // FIXME: Why doesn't this check for a subprogram or lexical block (AFAICT
 744   // the only valid scopes)?
 745   DIScope *Context = getNonCompileUnitScope(Scope);
 746
 747   auto *Node =
 748       DILocalVariable::get(VMContext, cast_or_null<DILocalScope>(Context), Name,
 749                            File, LineNo, Ty, ArgNo, Flags, AlignInBits);
 750   if (AlwaysPreserve) {
 751     // The optimizer may remove local variables. If there is an interest
 752     // to preserve variable info in such situation then stash it in a
 753     // named mdnode.
 754     DISubprogram *Fn = getDISubprogram(Scope);
 755     assert(Fn && "Missing subprogram for local variable");
 756     PreservedVariables[Fn].emplace_back(Node);
 757   }
 758   return Node;
 759 }
 760
 761 DILocalVariable *DIBuilder::createAutoVariable(DIScope *Scope, StringRef Name,
 762                                                DIFile *File, unsigned LineNo,
 763                                                DIType *Ty, bool AlwaysPreserve,
 764                                                DINode::DIFlags Flags,
 765                                                uint32_t AlignInBits) {
 766   return createLocalVariable(VMContext, PreservedVariables, Scope, Name,
 767                              /* ArgNo */ 0, File, LineNo, Ty, AlwaysPreserve,
 768                              Flags, AlignInBits);
 769 }
 770
 771 DILocalVariable *DIBuilder::createParameterVariable(
 772     DIScope *Scope, StringRef Name, unsigned ArgNo, DIFile *File,
 773     unsigned LineNo, DIType *Ty, bool AlwaysPreserve, DINode::DIFlags Flags) {
 774   assert(ArgNo && "Expected non-zero argument number for parameter");
 775   return createLocalVariable(VMContext, PreservedVariables, Scope, Name, ArgNo,
 776                              File, LineNo, Ty, AlwaysPreserve, Flags,
 777                              /* AlignInBits */0);
 778 }
 779
 780 DILabel *DIBuilder::createLabel(
 781     DIScope *Scope, StringRef Name, DIFile *File,
 782     unsigned LineNo, bool AlwaysPreserve) {
 783   DIScope *Context = getNonCompileUnitScope(Scope);
 784
 785   auto *Node =
 786       DILabel::get(VMContext, cast_or_null<DILocalScope>(Context), Name,
 787                    File, LineNo);
 788
 789   if (AlwaysPreserve) {
 790     /// The optimizer may remove labels. If there is an interest
 791     /// to preserve label info in such situation then append it to
 792     /// the list of retained nodes of the DISubprogram.
 793     DISubprogram *Fn = getDISubprogram(Scope);
 794     assert(Fn && "Missing subprogram for label");
 795     PreservedLabels[Fn].emplace_back(Node);
 796   }
 797   return Node;
 798 }
 799
 800 DIExpression *DIBuilder::createExpression(ArrayRef<uint64_t> Addr) {
 801   return DIExpression::get(VMContext, Addr);
 802 }
 803
 804 DIExpression *DIBuilder::createExpression(ArrayRef<int64_t> Signed) {
 805   // TODO: Remove the callers of this signed version and delete.
 806   SmallVector<uint64_t, 8> Addr(Signed.begin(), Signed.end());
 807   return createExpression(Addr);
 808 }
 809
 810 template <class... Ts>
 811 static DISubprogram *getSubprogram(bool IsDistinct, Ts &&... Args) {
 812   if (IsDistinct)
 813     return DISubprogram::getDistinct(std::forward<Ts>(Args)...);
 814   return DISubprogram::get(std::forward<Ts>(Args)...);
 815 }
 816
 817 DISubprogram *DIBuilder::createFunction(
 818     DIScope *Context, StringRef Name, StringRef LinkageName, DIFile *File,
 819     unsigned LineNo, DISubroutineType *Ty, unsigned ScopeLine,
 820     DINode::DIFlags Flags, DISubprogram::DISPFlags SPFlags,
 821     DITemplateParameterArray TParams, DISubprogram *Decl,
 822     DITypeArray ThrownTypes) {
 823   bool IsDefinition = SPFlags & DISubprogram::SPFlagDefinition;
 824   auto *Node = getSubprogram(
 825       /*IsDistinct=*/IsDefinition, VMContext, getNonCompileUnitScope(Context),
 826       Name, LinkageName, File, LineNo, Ty, ScopeLine, nullptr, 0, 0, Flags,
 827       SPFlags, IsDefinition ? CUNode : nullptr, TParams, Decl,
 828       MDTuple::getTemporary(VMContext, None).release(), ThrownTypes);
 829
 830   if (IsDefinition)
 831     AllSubprograms.push_back(Node);
 832   trackIfUnresolved(Node);
 833   return Node;
 834 }
 835
 836 DISubprogram *DIBuilder::createTempFunctionFwdDecl(
 837     DIScope *Context, StringRef Name, StringRef LinkageName, DIFile *File,
 838     unsigned LineNo, DISubroutineType *Ty, unsigned ScopeLine,
 839     DINode::DIFlags Flags, DISubprogram::DISPFlags SPFlags,
 840     DITemplateParameterArray TParams, DISubprogram *Decl,
 841     DITypeArray ThrownTypes) {
 842   bool IsDefinition = SPFlags & DISubprogram::SPFlagDefinition;
 843   return DISubprogram::getTemporary(VMContext, getNonCompileUnitScope(Context),
 844                                     Name, LinkageName, File, LineNo, Ty,
 845                                     ScopeLine, nullptr, 0, 0, Flags, SPFlags,
 846                                     IsDefinition ? CUNode : nullptr, TParams,
 847                                     Decl, nullptr, ThrownTypes)
 848       .release();
 849 }
 850
 851 DISubprogram *DIBuilder::createMethod(
 852     DIScope *Context, StringRef Name, StringRef LinkageName, DIFile *F,
 853     unsigned LineNo, DISubroutineType *Ty, unsigned VIndex, int ThisAdjustment,
 854     DIType *VTableHolder, DINode::DIFlags Flags,
 855     DISubprogram::DISPFlags SPFlags, DITemplateParameterArray TParams,
 856     DITypeArray ThrownTypes) {
 857   assert(getNonCompileUnitScope(Context) &&
 858          "Methods should have both a Context and a context that isn't "
 859          "the compile unit.");
 860   // FIXME: Do we want to use different scope/lines?
 861   bool IsDefinition = SPFlags & DISubprogram::SPFlagDefinition;
 862   auto *SP = getSubprogram(
 863       /*IsDistinct=*/IsDefinition, VMContext, cast<DIScope>(Context), Name,
 864       LinkageName, F, LineNo, Ty, LineNo, VTableHolder, VIndex, ThisAdjustment,
 865       Flags, SPFlags, IsDefinition ? CUNode : nullptr, TParams, nullptr,
 866       nullptr, ThrownTypes);
 867
 868   if (IsDefinition)
 869     AllSubprograms.push_back(SP);
 870   trackIfUnresolved(SP);
 871   return SP;
 872 }
 873
 874 DICommonBlock *DIBuilder::createCommonBlock(
 875     DIScope *Scope, DIGlobalVariable *Decl, StringRef Name, DIFile *File,
 876     unsigned LineNo) {
 877   return DICommonBlock::get(
 878       VMContext, Scope, Decl, Name, File, LineNo);
 879 }
 880
 881 DINamespace *DIBuilder::createNameSpace(DIScope *Scope, StringRef Name,
 882                                         bool ExportSymbols) {
 883
 884   // It is okay to *not* make anonymous top-level namespaces distinct, because
 885   // all nodes that have an anonymous namespace as their parent scope are
 886   // guaranteed to be unique and/or are linked to their containing
 887   // DICompileUnit. This decision is an explicit tradeoff of link time versus
 888   // memory usage versus code simplicity and may get revisited in the future.
 889   return DINamespace::get(VMContext, getNonCompileUnitScope(Scope), Name,
 890                           ExportSymbols);
 891 }
 892
 893 DIModule *DIBuilder::createModule(DIScope *Scope, StringRef Name,
 894                                   StringRef ConfigurationMacros,
 895                                   StringRef IncludePath, StringRef APINotesFile,
 896                                   DIFile *File, unsigned LineNo, bool IsDecl) {
 897   return DIModule::get(VMContext, File, getNonCompileUnitScope(Scope), Name,
 898                        ConfigurationMacros, IncludePath, APINotesFile, LineNo,
 899                        IsDecl);
 900 }
 901
 902 DILexicalBlockFile *DIBuilder::createLexicalBlockFile(DIScope *Scope,
 903                                                       DIFile *File,
 904                                                       unsigned Discriminator) {
 905   return DILexicalBlockFile::get(VMContext, Scope, File, Discriminator);
 906 }
 907
 908 DILexicalBlock *DIBuilder::createLexicalBlock(DIScope *Scope, DIFile *File,
 909                                               unsigned Line, unsigned Col) {
 910   // Make these distinct, to avoid merging two lexical blocks on the same
 911   // file/line/column.
 912   return DILexicalBlock::getDistinct(VMContext, getNonCompileUnitScope(Scope),
 913                                      File, Line, Col);
 914 }
 915
 916 Instruction *DIBuilder::insertDeclare(Value *Storage, DILocalVariable *VarInfo,
 917                                       DIExpression *Expr, const DILocation *DL,
 918                                       Instruction *InsertBefore) {
 919   return insertDeclare(Storage, VarInfo, Expr, DL, InsertBefore->getParent(),
 920                        InsertBefore);
 921 }
 922
 923 Instruction *DIBuilder::insertDeclare(Value *Storage, DILocalVariable *VarInfo,
 924                                       DIExpression *Expr, const DILocation *DL,
 925                                       BasicBlock *InsertAtEnd) {
 926   // If this block already has a terminator then insert this intrinsic before
 927   // the terminator. Otherwise, put it at the end of the block.
 928   Instruction *InsertBefore = InsertAtEnd->getTerminator();
 929   return insertDeclare(Storage, VarInfo, Expr, DL, InsertAtEnd, InsertBefore);
 930 }
 931
 932 Instruction *DIBuilder::insertLabel(DILabel *LabelInfo, const DILocation *DL,
 933                                     Instruction *InsertBefore) {
 934   return insertLabel(
 935       LabelInfo, DL, InsertBefore ? InsertBefore->getParent() : nullptr,
 936       InsertBefore);
 937 }
 938
 939 Instruction *DIBuilder::insertLabel(DILabel *LabelInfo, const DILocation *DL,
 940                                     BasicBlock *InsertAtEnd) {
 941   return insertLabel(LabelInfo, DL, InsertAtEnd, nullptr);
 942 }
 943
 944 Instruction *DIBuilder::insertDbgValueIntrinsic(Value *V,
 945                                                 DILocalVariable *VarInfo,
 946                                                 DIExpression *Expr,
 947                                                 const DILocation *DL,
 948                                                 Instruction *InsertBefore) {
 949   return insertDbgValueIntrinsic(
 950       V, VarInfo, Expr, DL, InsertBefore ? InsertBefore->getParent() : nullptr,
 951       InsertBefore);
 952 }
 953
 954 Instruction *DIBuilder::insertDbgValueIntrinsic(Value *V,
 955                                                 DILocalVariable *VarInfo,
 956                                                 DIExpression *Expr,
 957                                                 const DILocation *DL,
 958                                                 BasicBlock *InsertAtEnd) {
 959   return insertDbgValueIntrinsic(V, VarInfo, Expr, DL, InsertAtEnd, nullptr);
 960 }
 961
 962 /// Initialize IRBuilder for inserting dbg.declare and dbg.value intrinsics.
 963 /// This abstracts over the various ways to specify an insert position.
 964 static void initIRBuilder(IRBuilder<> &Builder, const DILocation *DL,
 965                           BasicBlock *InsertBB, Instruction *InsertBefore) {
 966   if (InsertBefore)
 967     Builder.SetInsertPoint(InsertBefore);
 968   else if (InsertBB)
 969     Builder.SetInsertPoint(InsertBB);
 970   Builder.SetCurrentDebugLocation(DL);
 971 }
 972
 973 static Value *getDbgIntrinsicValueImpl(LLVMContext &VMContext, Value *V) {
 974   assert(V && "no value passed to dbg intrinsic");
 975   return MetadataAsValue::get(VMContext, ValueAsMetadata::get(V));
 976 }
 977
 978 static Function *getDeclareIntrin(Module &M) {
 979   return Intrinsic::getDeclaration(&M, UseDbgAddr ? Intrinsic::dbg_addr
 980                                                   : Intrinsic::dbg_declare);
 981 }
 982
 983 Instruction *DIBuilder::insertDeclare(Value *Storage, DILocalVariable *VarInfo,
 984                                       DIExpression *Expr, const DILocation *DL,
 985                                       BasicBlock *InsertBB, Instruction *InsertBefore) {
 986   assert(VarInfo && "empty or invalid DILocalVariable* passed to dbg.declare");
 987   assert(DL && "Expected debug loc");
 988   assert(DL->getScope()->getSubprogram() ==
 989              VarInfo->getScope()->getSubprogram() &&
 990          "Expected matching subprograms");
 991   if (!DeclareFn)
 992     DeclareFn = getDeclareIntrin(M);
 993
 994   trackIfUnresolved(VarInfo);
 995   trackIfUnresolved(Expr);
 996   Value *Args[] = {getDbgIntrinsicValueImpl(VMContext, Storage),
 997                    MetadataAsValue::get(VMContext, VarInfo),
 998                    MetadataAsValue::get(VMContext, Expr)};
 999
1000   IRBuilder<> B(DL->getContext());
1001   initIRBuilder(B, DL, InsertBB, InsertBefore);
1002   return B.CreateCall(DeclareFn, Args);
1003 }
1004
1005 Instruction *DIBuilder::insertDbgValueIntrinsic(
1006     Value *V, DILocalVariable *VarInfo, DIExpression *Expr,
1007     const DILocation *DL, BasicBlock *InsertBB, Instruction *InsertBefore) {
1008   assert(V && "no value passed to dbg.value");
1009   assert(VarInfo && "empty or invalid DILocalVariable* passed to dbg.value");
1010   assert(DL && "Expected debug loc");
1011   assert(DL->getScope()->getSubprogram() ==
1012              VarInfo->getScope()->getSubprogram() &&
1013          "Expected matching subprograms");
1014   if (!ValueFn)
1015     ValueFn = Intrinsic::getDeclaration(&M, Intrinsic::dbg_value);
1016
1017   trackIfUnresolved(VarInfo);
1018   trackIfUnresolved(Expr);
1019   Value *Args[] = {getDbgIntrinsicValueImpl(VMContext, V),
1020                    MetadataAsValue::get(VMContext, VarInfo),
1021                    MetadataAsValue::get(VMContext, Expr)};
1022
1023   IRBuilder<> B(DL->getContext());
1024   initIRBuilder(B, DL, InsertBB, InsertBefore);
1025   return B.CreateCall(ValueFn, Args);
1026 }
1027
1028 Instruction *DIBuilder::insertLabel(
1029     DILabel *LabelInfo, const DILocation *DL,
1030     BasicBlock *InsertBB, Instruction *InsertBefore) {
1031   assert(LabelInfo && "empty or invalid DILabel* passed to dbg.label");
1032   assert(DL && "Expected debug loc");
1033   assert(DL->getScope()->getSubprogram() ==
1034              LabelInfo->getScope()->getSubprogram() &&
1035          "Expected matching subprograms");
1036   if (!LabelFn)
1037     LabelFn = Intrinsic::getDeclaration(&M, Intrinsic::dbg_label);
1038
1039   trackIfUnresolved(LabelInfo);
1040   Value *Args[] = {MetadataAsValue::get(VMContext, LabelInfo)};
1041
1042   IRBuilder<> B(DL->getContext());
1043   initIRBuilder(B, DL, InsertBB, InsertBefore);
1044   return B.CreateCall(LabelFn, Args);
1045 }
1046
1047 void DIBuilder::replaceVTableHolder(DICompositeType *&T,
1048                                     DIType *VTableHolder) {
1049   {
1050     TypedTrackingMDRef<DICompositeType> N(T);
1051     N->replaceVTableHolder(VTableHolder);
1052     T = N.get();
1053   }
1054
1055   // If this didn't create a self-reference, just return.
1056   if (T != VTableHolder)
1057     return;
1058
1059   // Look for unresolved operands.  T will drop RAUW support, orphaning any
1060   // cycles underneath it.
1061   if (T->isResolved())
1062     for (const MDOperand &O : T->operands())
1063       if (auto *N = dyn_cast_or_null<MDNode>(O))
1064         trackIfUnresolved(N);
1065 }
1066
1067 void DIBuilder::replaceArrays(DICompositeType *&T, DINodeArray Elements,
1068                               DINodeArray TParams) {
1069   {
1070     TypedTrackingMDRef<DICompositeType> N(T);
1071     if (Elements)
1072       N->replaceElements(Elements);
1073     if (TParams)
1074       N->replaceTemplateParams(DITemplateParameterArray(TParams));
1075     T = N.get();
1076   }
1077
1078   // If T isn't resolved, there's no problem.
1079   if (!T->isResolved())
1080     return;
1081
1082   // If T is resolved, it may be due to a self-reference cycle.  Track the
1083   // arrays explicitly if they're unresolved, or else the cycles will be
1084   // orphaned.
1085   if (Elements)
1086     trackIfUnresolved(Elements.get());
1087   if (TParams)
1088     trackIfUnresolved(TParams.get());
1089 }