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/APInt.h"
  16 #include "llvm/ADT/APSInt.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/Module.h"
  22 #include "llvm/Support/CommandLine.h"
  23 #include <optional>
  24
  25 using namespace llvm;
  26 using namespace llvm::dwarf;
  27
  28 DIBuilder::DIBuilder(Module &m, bool AllowUnresolvedNodes, DICompileUnit *CU)
  29     : M(m), VMContext(M.getContext()), CUNode(CU), DeclareFn(nullptr),
  30       ValueFn(nullptr), LabelFn(nullptr), AssignFn(nullptr),
  31       AllowUnresolvedNodes(AllowUnresolvedNodes) {
  32   if (CUNode) {
  33     if (const auto &ETs = CUNode->getEnumTypes())
  34       AllEnumTypes.assign(ETs.begin(), ETs.end());
  35     if (const auto &RTs = CUNode->getRetainedTypes())
  36       AllRetainTypes.assign(RTs.begin(), RTs.end());
  37     if (const auto &GVs = CUNode->getGlobalVariables())
  38       AllGVs.assign(GVs.begin(), GVs.end());
  39     if (const auto &IMs = CUNode->getImportedEntities())
  40       ImportedModules.assign(IMs.begin(), IMs.end());
  41     if (const auto &MNs = CUNode->getMacros())
  42       AllMacrosPerParent.insert({nullptr, {MNs.begin(), MNs.end()}});
  43   }
  44 }
  45
  46 void DIBuilder::trackIfUnresolved(MDNode *N) {
  47   if (!N)
  48     return;
  49   if (N->isResolved())
  50     return;
  51
  52   assert(AllowUnresolvedNodes && "Cannot handle unresolved nodes");
  53   UnresolvedNodes.emplace_back(N);
  54 }
  55
  56 void DIBuilder::finalizeSubprogram(DISubprogram *SP) {
  57   auto PN = SubprogramTrackedNodes.find(SP);
  58   if (PN != SubprogramTrackedNodes.end())
  59     SP->replaceRetainedNodes(
  60         MDTuple::get(VMContext, SmallVector<Metadata *, 16>(PN->second.begin(),
  61                                                             PN->second.end())));
  62 }
  63
  64 void DIBuilder::finalize() {
  65   if (!CUNode) {
  66     assert(!AllowUnresolvedNodes &&
  67            "creating type nodes without a CU is not supported");
  68     return;
  69   }
  70
  71   if (!AllEnumTypes.empty())
  72     CUNode->replaceEnumTypes(MDTuple::get(
  73         VMContext, SmallVector<Metadata *, 16>(AllEnumTypes.begin(),
  74                                                AllEnumTypes.end())));
  75
  76   SmallVector<Metadata *, 16> RetainValues;
  77   // Declarations and definitions of the same type may be retained. Some
  78   // clients RAUW these pairs, leaving duplicates in the retained types
  79   // list. Use a set to remove the duplicates while we transform the
  80   // TrackingVHs back into Values.
  81   SmallPtrSet<Metadata *, 16> RetainSet;
  82   for (unsigned I = 0, E = AllRetainTypes.size(); I < E; I++)
  83     if (RetainSet.insert(AllRetainTypes[I]).second)
  84       RetainValues.push_back(AllRetainTypes[I]);
  85
  86   if (!RetainValues.empty())
  87     CUNode->replaceRetainedTypes(MDTuple::get(VMContext, RetainValues));
  88
  89   for (auto *SP : AllSubprograms)
  90     finalizeSubprogram(SP);
  91   for (auto *N : RetainValues)
  92     if (auto *SP = dyn_cast<DISubprogram>(N))
  93       finalizeSubprogram(SP);
  94
  95   if (!AllGVs.empty())
  96     CUNode->replaceGlobalVariables(MDTuple::get(VMContext, AllGVs));
  97
  98   if (!ImportedModules.empty())
  99     CUNode->replaceImportedEntities(MDTuple::get(
 100         VMContext, SmallVector<Metadata *, 16>(ImportedModules.begin(),
 101                                                ImportedModules.end())));
 102
 103   for (const auto &I : AllMacrosPerParent) {
 104     // DIMacroNode's with nullptr parent are DICompileUnit direct children.
 105     if (!I.first) {
 106       CUNode->replaceMacros(MDTuple::get(VMContext, I.second.getArrayRef()));
 107       continue;
 108     }
 109     // Otherwise, it must be a temporary DIMacroFile that need to be resolved.
 110     auto *TMF = cast<DIMacroFile>(I.first);
 111     auto *MF = DIMacroFile::get(VMContext, dwarf::DW_MACINFO_start_file,
 112                                 TMF->getLine(), TMF->getFile(),
 113                                 getOrCreateMacroArray(I.second.getArrayRef()));
 114     replaceTemporary(llvm::TempDIMacroNode(TMF), MF);
 115   }
 116
 117   // Now that all temp nodes have been replaced or deleted, resolve remaining
 118   // cycles.
 119   for (const auto &N : UnresolvedNodes)
 120     if (N && !N->isResolved())
 121       N->resolveCycles();
 122   UnresolvedNodes.clear();
 123
 124   // Can't handle unresolved nodes anymore.
 125   AllowUnresolvedNodes = false;
 126 }
 127
 128 /// If N is compile unit return NULL otherwise return N.
 129 static DIScope *getNonCompileUnitScope(DIScope *N) {
 130   if (!N || isa<DICompileUnit>(N))
 131     return nullptr;
 132   return cast<DIScope>(N);
 133 }
 134
 135 DICompileUnit *DIBuilder::createCompileUnit(
 136     unsigned Lang, DIFile *File, StringRef Producer, bool isOptimized,
 137     StringRef Flags, unsigned RunTimeVer, StringRef SplitName,
 138     DICompileUnit::DebugEmissionKind Kind, uint64_t DWOId,
 139     bool SplitDebugInlining, bool DebugInfoForProfiling,
 140     DICompileUnit::DebugNameTableKind NameTableKind, bool RangesBaseAddress,
 141     StringRef SysRoot, StringRef SDK) {
 142
 143   assert(((Lang <= dwarf::DW_LANG_Mojo && Lang >= dwarf::DW_LANG_C89) ||
 144           (Lang <= dwarf::DW_LANG_hi_user && Lang >= dwarf::DW_LANG_lo_user)) &&
 145          "Invalid Language tag");
 146
 147   assert(!CUNode && "Can only make one compile unit per DIBuilder instance");
 148   CUNode = DICompileUnit::getDistinct(
 149       VMContext, Lang, File, Producer, isOptimized, Flags, RunTimeVer,
 150       SplitName, Kind, nullptr, nullptr, nullptr, nullptr, nullptr, DWOId,
 151       SplitDebugInlining, DebugInfoForProfiling, NameTableKind,
 152       RangesBaseAddress, SysRoot, SDK);
 153
 154   // Create a named metadata so that it is easier to find cu in a module.
 155   NamedMDNode *NMD = M.getOrInsertNamedMetadata("llvm.dbg.cu");
 156   NMD->addOperand(CUNode);
 157   trackIfUnresolved(CUNode);
 158   return CUNode;
 159 }
 160
 161 static DIImportedEntity *
 162 createImportedModule(LLVMContext &C, dwarf::Tag Tag, DIScope *Context,
 163                      Metadata *NS, DIFile *File, unsigned Line, StringRef Name,
 164                      DINodeArray Elements,
 165                      SmallVectorImpl<TrackingMDNodeRef> &ImportedModules) {
 166   if (Line)
 167     assert(File && "Source location has line number but no file");
 168   unsigned EntitiesCount = C.pImpl->DIImportedEntitys.size();
 169   auto *M = DIImportedEntity::get(C, Tag, Context, cast_or_null<DINode>(NS),
 170                                   File, Line, Name, Elements);
 171   if (EntitiesCount < C.pImpl->DIImportedEntitys.size())
 172     // A new Imported Entity was just added to the context.
 173     // Add it to the Imported Modules list.
 174     ImportedModules.emplace_back(M);
 175   return M;
 176 }
 177
 178 DIImportedEntity *DIBuilder::createImportedModule(DIScope *Context,
 179                                                   DINamespace *NS, DIFile *File,
 180                                                   unsigned Line,
 181                                                   DINodeArray Elements) {
 182   return ::createImportedModule(VMContext, dwarf::DW_TAG_imported_module,
 183                                 Context, NS, File, Line, StringRef(), Elements,
 184                                 getImportTrackingVector(Context));
 185 }
 186
 187 DIImportedEntity *DIBuilder::createImportedModule(DIScope *Context,
 188                                                   DIImportedEntity *NS,
 189                                                   DIFile *File, unsigned Line,
 190                                                   DINodeArray Elements) {
 191   return ::createImportedModule(VMContext, dwarf::DW_TAG_imported_module,
 192                                 Context, NS, File, Line, StringRef(), Elements,
 193                                 getImportTrackingVector(Context));
 194 }
 195
 196 DIImportedEntity *DIBuilder::createImportedModule(DIScope *Context, DIModule *M,
 197                                                   DIFile *File, unsigned Line,
 198                                                   DINodeArray Elements) {
 199   return ::createImportedModule(VMContext, dwarf::DW_TAG_imported_module,
 200                                 Context, M, File, Line, StringRef(), Elements,
 201                                 getImportTrackingVector(Context));
 202 }
 203
 204 DIImportedEntity *
 205 DIBuilder::createImportedDeclaration(DIScope *Context, DINode *Decl,
 206                                      DIFile *File, unsigned Line,
 207                                      StringRef Name, DINodeArray Elements) {
 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, Elements,
 212                                 getImportTrackingVector(Context));
 213 }
 214
 215 DIFile *DIBuilder::createFile(StringRef Filename, StringRef Directory,
 216                               std::optional<DIFile::ChecksumInfo<StringRef>> CS,
 217                               std::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, const 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 DIStringType *DIBuilder::createStringType(StringRef Name,
 282                                           DIVariable *StringLength,
 283                                           DIExpression *StrLocationExp) {
 284   assert(!Name.empty() && "Unable to create type without name");
 285   return DIStringType::get(VMContext, dwarf::DW_TAG_string_type, Name,
 286                            StringLength, nullptr, StrLocationExp, 0, 0, 0);
 287 }
 288
 289 DIStringType *DIBuilder::createStringType(StringRef Name,
 290                                           DIExpression *StringLengthExp,
 291                                           DIExpression *StrLocationExp) {
 292   assert(!Name.empty() && "Unable to create type without name");
 293   return DIStringType::get(VMContext, dwarf::DW_TAG_string_type, Name, nullptr,
 294                            StringLengthExp, StrLocationExp, 0, 0, 0);
 295 }
 296
 297 DIDerivedType *DIBuilder::createQualifiedType(unsigned Tag, DIType *FromTy) {
 298   return DIDerivedType::get(VMContext, Tag, "", nullptr, 0, nullptr, FromTy, 0,
 299                             0, 0, std::nullopt, DINode::FlagZero);
 300 }
 301
 302 DIDerivedType *
 303 DIBuilder::createPointerType(DIType *PointeeTy, uint64_t SizeInBits,
 304                              uint32_t AlignInBits,
 305                              std::optional<unsigned> DWARFAddressSpace,
 306                              StringRef Name, DINodeArray Annotations) {
 307   // FIXME: Why is there a name here?
 308   return DIDerivedType::get(VMContext, dwarf::DW_TAG_pointer_type, Name,
 309                             nullptr, 0, nullptr, PointeeTy, SizeInBits,
 310                             AlignInBits, 0, DWARFAddressSpace, DINode::FlagZero,
 311                             nullptr, Annotations);
 312 }
 313
 314 DIDerivedType *DIBuilder::createMemberPointerType(DIType *PointeeTy,
 315                                                   DIType *Base,
 316                                                   uint64_t SizeInBits,
 317                                                   uint32_t AlignInBits,
 318                                                   DINode::DIFlags Flags) {
 319   return DIDerivedType::get(VMContext, dwarf::DW_TAG_ptr_to_member_type, "",
 320                             nullptr, 0, nullptr, PointeeTy, SizeInBits,
 321                             AlignInBits, 0, std::nullopt, Flags, Base);
 322 }
 323
 324 DIDerivedType *
 325 DIBuilder::createReferenceType(unsigned Tag, DIType *RTy, uint64_t SizeInBits,
 326                                uint32_t AlignInBits,
 327                                std::optional<unsigned> DWARFAddressSpace) {
 328   assert(RTy && "Unable to create reference type");
 329   return DIDerivedType::get(VMContext, Tag, "", nullptr, 0, nullptr, RTy,
 330                             SizeInBits, AlignInBits, 0, DWARFAddressSpace,
 331                             DINode::FlagZero);
 332 }
 333
 334 DIDerivedType *DIBuilder::createTypedef(DIType *Ty, StringRef Name,
 335                                         DIFile *File, unsigned LineNo,
 336                                         DIScope *Context, uint32_t AlignInBits,
 337                                         DINode::DIFlags Flags,
 338                                         DINodeArray Annotations) {
 339   return DIDerivedType::get(VMContext, dwarf::DW_TAG_typedef, Name, File,
 340                             LineNo, getNonCompileUnitScope(Context), Ty, 0,
 341                             AlignInBits, 0, std::nullopt, Flags, nullptr,
 342                             Annotations);
 343 }
 344
 345 DIDerivedType *DIBuilder::createFriend(DIType *Ty, DIType *FriendTy) {
 346   assert(Ty && "Invalid type!");
 347   assert(FriendTy && "Invalid friend type!");
 348   return DIDerivedType::get(VMContext, dwarf::DW_TAG_friend, "", nullptr, 0, Ty,
 349                             FriendTy, 0, 0, 0, std::nullopt, DINode::FlagZero);
 350 }
 351
 352 DIDerivedType *DIBuilder::createInheritance(DIType *Ty, DIType *BaseTy,
 353                                             uint64_t BaseOffset,
 354                                             uint32_t VBPtrOffset,
 355                                             DINode::DIFlags Flags) {
 356   assert(Ty && "Unable to create inheritance");
 357   Metadata *ExtraData = ConstantAsMetadata::get(
 358       ConstantInt::get(IntegerType::get(VMContext, 32), VBPtrOffset));
 359   return DIDerivedType::get(VMContext, dwarf::DW_TAG_inheritance, "", nullptr,
 360                             0, Ty, BaseTy, 0, 0, BaseOffset, std::nullopt,
 361                             Flags, ExtraData);
 362 }
 363
 364 DIDerivedType *DIBuilder::createMemberType(
 365     DIScope *Scope, StringRef Name, DIFile *File, unsigned LineNumber,
 366     uint64_t SizeInBits, uint32_t AlignInBits, uint64_t OffsetInBits,
 367     DINode::DIFlags Flags, DIType *Ty, DINodeArray Annotations) {
 368   return DIDerivedType::get(VMContext, dwarf::DW_TAG_member, Name, File,
 369                             LineNumber, getNonCompileUnitScope(Scope), Ty,
 370                             SizeInBits, AlignInBits, OffsetInBits, std::nullopt,
 371                             Flags, nullptr, Annotations);
 372 }
 373
 374 static ConstantAsMetadata *getConstantOrNull(Constant *C) {
 375   if (C)
 376     return ConstantAsMetadata::get(C);
 377   return nullptr;
 378 }
 379
 380 DIDerivedType *DIBuilder::createVariantMemberType(
 381     DIScope *Scope, StringRef Name, DIFile *File, unsigned LineNumber,
 382     uint64_t SizeInBits, uint32_t AlignInBits, uint64_t OffsetInBits,
 383     Constant *Discriminant, DINode::DIFlags Flags, DIType *Ty) {
 384   return DIDerivedType::get(VMContext, dwarf::DW_TAG_member, Name, File,
 385                             LineNumber, getNonCompileUnitScope(Scope), Ty,
 386                             SizeInBits, AlignInBits, OffsetInBits, std::nullopt,
 387                             Flags, getConstantOrNull(Discriminant));
 388 }
 389
 390 DIDerivedType *DIBuilder::createBitFieldMemberType(
 391     DIScope *Scope, StringRef Name, DIFile *File, unsigned LineNumber,
 392     uint64_t SizeInBits, uint64_t OffsetInBits, uint64_t StorageOffsetInBits,
 393     DINode::DIFlags Flags, DIType *Ty, DINodeArray Annotations) {
 394   Flags |= DINode::FlagBitField;
 395   return DIDerivedType::get(
 396       VMContext, dwarf::DW_TAG_member, Name, File, LineNumber,
 397       getNonCompileUnitScope(Scope), Ty, SizeInBits, /*AlignInBits=*/0,
 398       OffsetInBits, std::nullopt, Flags,
 399       ConstantAsMetadata::get(ConstantInt::get(IntegerType::get(VMContext, 64),
 400                                                StorageOffsetInBits)),
 401       Annotations);
 402 }
 403
 404 DIDerivedType *
 405 DIBuilder::createStaticMemberType(DIScope *Scope, StringRef Name, DIFile *File,
 406                                   unsigned LineNumber, DIType *Ty,
 407                                   DINode::DIFlags Flags, llvm::Constant *Val,
 408                                   uint32_t AlignInBits) {
 409   Flags |= DINode::FlagStaticMember;
 410   return DIDerivedType::get(VMContext, dwarf::DW_TAG_member, Name, File,
 411                             LineNumber, getNonCompileUnitScope(Scope), Ty, 0,
 412                             AlignInBits, 0, std::nullopt, Flags,
 413                             getConstantOrNull(Val));
 414 }
 415
 416 DIDerivedType *
 417 DIBuilder::createObjCIVar(StringRef Name, DIFile *File, unsigned LineNumber,
 418                           uint64_t SizeInBits, uint32_t AlignInBits,
 419                           uint64_t OffsetInBits, DINode::DIFlags Flags,
 420                           DIType *Ty, MDNode *PropertyNode) {
 421   return DIDerivedType::get(VMContext, dwarf::DW_TAG_member, Name, File,
 422                             LineNumber, getNonCompileUnitScope(File), Ty,
 423                             SizeInBits, AlignInBits, OffsetInBits, std::nullopt,
 424                             Flags, PropertyNode);
 425 }
 426
 427 DIObjCProperty *
 428 DIBuilder::createObjCProperty(StringRef Name, DIFile *File, unsigned LineNumber,
 429                               StringRef GetterName, StringRef SetterName,
 430                               unsigned PropertyAttributes, DIType *Ty) {
 431   return DIObjCProperty::get(VMContext, Name, File, LineNumber, GetterName,
 432                              SetterName, PropertyAttributes, Ty);
 433 }
 434
 435 DITemplateTypeParameter *
 436 DIBuilder::createTemplateTypeParameter(DIScope *Context, StringRef Name,
 437                                        DIType *Ty, bool isDefault) {
 438   assert((!Context || isa<DICompileUnit>(Context)) && "Expected compile unit");
 439   return DITemplateTypeParameter::get(VMContext, Name, Ty, isDefault);
 440 }
 441
 442 static DITemplateValueParameter *
 443 createTemplateValueParameterHelper(LLVMContext &VMContext, unsigned Tag,
 444                                    DIScope *Context, StringRef Name, DIType *Ty,
 445                                    bool IsDefault, Metadata *MD) {
 446   assert((!Context || isa<DICompileUnit>(Context)) && "Expected compile unit");
 447   return DITemplateValueParameter::get(VMContext, Tag, Name, Ty, IsDefault, MD);
 448 }
 449
 450 DITemplateValueParameter *
 451 DIBuilder::createTemplateValueParameter(DIScope *Context, StringRef Name,
 452                                         DIType *Ty, bool isDefault,
 453                                         Constant *Val) {
 454   return createTemplateValueParameterHelper(
 455       VMContext, dwarf::DW_TAG_template_value_parameter, Context, Name, Ty,
 456       isDefault, getConstantOrNull(Val));
 457 }
 458
 459 DITemplateValueParameter *
 460 DIBuilder::createTemplateTemplateParameter(DIScope *Context, StringRef Name,
 461                                            DIType *Ty, StringRef Val,
 462                                            bool IsDefault) {
 463   return createTemplateValueParameterHelper(
 464       VMContext, dwarf::DW_TAG_GNU_template_template_param, Context, Name, Ty,
 465       IsDefault, MDString::get(VMContext, Val));
 466 }
 467
 468 DITemplateValueParameter *
 469 DIBuilder::createTemplateParameterPack(DIScope *Context, StringRef Name,
 470                                        DIType *Ty, DINodeArray Val) {
 471   return createTemplateValueParameterHelper(
 472       VMContext, dwarf::DW_TAG_GNU_template_parameter_pack, Context, Name, Ty,
 473       false, Val.get());
 474 }
 475
 476 DICompositeType *DIBuilder::createClassType(
 477     DIScope *Context, StringRef Name, DIFile *File, unsigned LineNumber,
 478     uint64_t SizeInBits, uint32_t AlignInBits, uint64_t OffsetInBits,
 479     DINode::DIFlags Flags, DIType *DerivedFrom, DINodeArray Elements,
 480     DIType *VTableHolder, MDNode *TemplateParams, StringRef UniqueIdentifier) {
 481   assert((!Context || isa<DIScope>(Context)) &&
 482          "createClassType should be called with a valid Context");
 483
 484   auto *R = DICompositeType::get(
 485       VMContext, dwarf::DW_TAG_structure_type, Name, File, LineNumber,
 486       getNonCompileUnitScope(Context), DerivedFrom, SizeInBits, AlignInBits,
 487       OffsetInBits, Flags, Elements, 0, VTableHolder,
 488       cast_or_null<MDTuple>(TemplateParams), UniqueIdentifier);
 489   trackIfUnresolved(R);
 490   return R;
 491 }
 492
 493 DICompositeType *DIBuilder::createStructType(
 494     DIScope *Context, StringRef Name, DIFile *File, unsigned LineNumber,
 495     uint64_t SizeInBits, uint32_t AlignInBits, DINode::DIFlags Flags,
 496     DIType *DerivedFrom, DINodeArray Elements, unsigned RunTimeLang,
 497     DIType *VTableHolder, StringRef UniqueIdentifier) {
 498   auto *R = DICompositeType::get(
 499       VMContext, dwarf::DW_TAG_structure_type, Name, File, LineNumber,
 500       getNonCompileUnitScope(Context), DerivedFrom, SizeInBits, AlignInBits, 0,
 501       Flags, Elements, RunTimeLang, VTableHolder, nullptr, UniqueIdentifier);
 502   trackIfUnresolved(R);
 503   return R;
 504 }
 505
 506 DICompositeType *DIBuilder::createUnionType(
 507     DIScope *Scope, StringRef Name, DIFile *File, unsigned LineNumber,
 508     uint64_t SizeInBits, uint32_t AlignInBits, DINode::DIFlags Flags,
 509     DINodeArray Elements, unsigned RunTimeLang, StringRef UniqueIdentifier) {
 510   auto *R = DICompositeType::get(
 511       VMContext, dwarf::DW_TAG_union_type, Name, File, LineNumber,
 512       getNonCompileUnitScope(Scope), nullptr, SizeInBits, AlignInBits, 0, Flags,
 513       Elements, RunTimeLang, nullptr, nullptr, UniqueIdentifier);
 514   trackIfUnresolved(R);
 515   return R;
 516 }
 517
 518 DICompositeType *
 519 DIBuilder::createVariantPart(DIScope *Scope, StringRef Name, DIFile *File,
 520                              unsigned LineNumber, uint64_t SizeInBits,
 521                              uint32_t AlignInBits, DINode::DIFlags Flags,
 522                              DIDerivedType *Discriminator, DINodeArray Elements,
 523                              StringRef UniqueIdentifier) {
 524   auto *R = DICompositeType::get(
 525       VMContext, dwarf::DW_TAG_variant_part, Name, File, LineNumber,
 526       getNonCompileUnitScope(Scope), nullptr, SizeInBits, AlignInBits, 0, Flags,
 527       Elements, 0, nullptr, nullptr, UniqueIdentifier, Discriminator);
 528   trackIfUnresolved(R);
 529   return R;
 530 }
 531
 532 DISubroutineType *DIBuilder::createSubroutineType(DITypeRefArray ParameterTypes,
 533                                                   DINode::DIFlags Flags,
 534                                                   unsigned CC) {
 535   return DISubroutineType::get(VMContext, Flags, CC, ParameterTypes);
 536 }
 537
 538 DICompositeType *DIBuilder::createEnumerationType(
 539     DIScope *Scope, StringRef Name, DIFile *File, unsigned LineNumber,
 540     uint64_t SizeInBits, uint32_t AlignInBits, DINodeArray Elements,
 541     DIType *UnderlyingType, StringRef UniqueIdentifier, bool IsScoped) {
 542   auto *CTy = DICompositeType::get(
 543       VMContext, dwarf::DW_TAG_enumeration_type, Name, File, LineNumber,
 544       getNonCompileUnitScope(Scope), UnderlyingType, SizeInBits, AlignInBits, 0,
 545       IsScoped ? DINode::FlagEnumClass : DINode::FlagZero, Elements, 0, nullptr,
 546       nullptr, UniqueIdentifier);
 547   AllEnumTypes.emplace_back(CTy);
 548   trackIfUnresolved(CTy);
 549   return CTy;
 550 }
 551
 552 DIDerivedType *DIBuilder::createSetType(DIScope *Scope, StringRef Name,
 553                                         DIFile *File, unsigned LineNo,
 554                                         uint64_t SizeInBits,
 555                                         uint32_t AlignInBits, DIType *Ty) {
 556   auto *R =
 557       DIDerivedType::get(VMContext, dwarf::DW_TAG_set_type, Name, File, LineNo,
 558                          getNonCompileUnitScope(Scope), Ty, SizeInBits,
 559                          AlignInBits, 0, std::nullopt, DINode::FlagZero);
 560   trackIfUnresolved(R);
 561   return R;
 562 }
 563
 564 DICompositeType *
 565 DIBuilder::createArrayType(uint64_t Size, uint32_t AlignInBits, DIType *Ty,
 566                            DINodeArray Subscripts,
 567                            PointerUnion<DIExpression *, DIVariable *> DL,
 568                            PointerUnion<DIExpression *, DIVariable *> AS,
 569                            PointerUnion<DIExpression *, DIVariable *> AL,
 570                            PointerUnion<DIExpression *, DIVariable *> RK) {
 571   auto *R = DICompositeType::get(
 572       VMContext, dwarf::DW_TAG_array_type, "", nullptr, 0, nullptr, Ty, Size,
 573       AlignInBits, 0, DINode::FlagZero, Subscripts, 0, nullptr, nullptr, "",
 574       nullptr,
 575       isa<DIExpression *>(DL) ? (Metadata *)cast<DIExpression *>(DL)
 576                               : (Metadata *)cast<DIVariable *>(DL),
 577       isa<DIExpression *>(AS) ? (Metadata *)cast<DIExpression *>(AS)
 578                               : (Metadata *)cast<DIVariable *>(AS),
 579       isa<DIExpression *>(AL) ? (Metadata *)cast<DIExpression *>(AL)
 580                               : (Metadata *)cast<DIVariable *>(AL),
 581       isa<DIExpression *>(RK) ? (Metadata *)cast<DIExpression *>(RK)
 582                               : (Metadata *)cast<DIVariable *>(RK));
 583   trackIfUnresolved(R);
 584   return R;
 585 }
 586
 587 DICompositeType *DIBuilder::createVectorType(uint64_t Size,
 588                                              uint32_t AlignInBits, DIType *Ty,
 589                                              DINodeArray Subscripts) {
 590   auto *R = DICompositeType::get(VMContext, dwarf::DW_TAG_array_type, "",
 591                                  nullptr, 0, nullptr, Ty, Size, AlignInBits, 0,
 592                                  DINode::FlagVector, Subscripts, 0, nullptr);
 593   trackIfUnresolved(R);
 594   return R;
 595 }
 596
 597 DISubprogram *DIBuilder::createArtificialSubprogram(DISubprogram *SP) {
 598   auto NewSP = SP->cloneWithFlags(SP->getFlags() | DINode::FlagArtificial);
 599   return MDNode::replaceWithDistinct(std::move(NewSP));
 600 }
 601
 602 static DIType *createTypeWithFlags(const DIType *Ty,
 603                                    DINode::DIFlags FlagsToSet) {
 604   auto NewTy = Ty->cloneWithFlags(Ty->getFlags() | FlagsToSet);
 605   return MDNode::replaceWithUniqued(std::move(NewTy));
 606 }
 607
 608 DIType *DIBuilder::createArtificialType(DIType *Ty) {
 609   // FIXME: Restrict this to the nodes where it's valid.
 610   if (Ty->isArtificial())
 611     return Ty;
 612   return createTypeWithFlags(Ty, DINode::FlagArtificial);
 613 }
 614
 615 DIType *DIBuilder::createObjectPointerType(DIType *Ty) {
 616   // FIXME: Restrict this to the nodes where it's valid.
 617   if (Ty->isObjectPointer())
 618     return Ty;
 619   DINode::DIFlags Flags = DINode::FlagObjectPointer | DINode::FlagArtificial;
 620   return createTypeWithFlags(Ty, Flags);
 621 }
 622
 623 void DIBuilder::retainType(DIScope *T) {
 624   assert(T && "Expected non-null type");
 625   assert((isa<DIType>(T) || (isa<DISubprogram>(T) &&
 626                              cast<DISubprogram>(T)->isDefinition() == false)) &&
 627          "Expected type or subprogram declaration");
 628   AllRetainTypes.emplace_back(T);
 629 }
 630
 631 DIBasicType *DIBuilder::createUnspecifiedParameter() { return nullptr; }
 632
 633 DICompositeType *
 634 DIBuilder::createForwardDecl(unsigned Tag, StringRef Name, DIScope *Scope,
 635                              DIFile *F, unsigned Line, unsigned RuntimeLang,
 636                              uint64_t SizeInBits, uint32_t AlignInBits,
 637                              StringRef UniqueIdentifier) {
 638   // FIXME: Define in terms of createReplaceableForwardDecl() by calling
 639   // replaceWithUniqued().
 640   auto *RetTy = DICompositeType::get(
 641       VMContext, Tag, Name, F, Line, getNonCompileUnitScope(Scope), nullptr,
 642       SizeInBits, AlignInBits, 0, DINode::FlagFwdDecl, nullptr, RuntimeLang,
 643       nullptr, nullptr, UniqueIdentifier);
 644   trackIfUnresolved(RetTy);
 645   return RetTy;
 646 }
 647
 648 DICompositeType *DIBuilder::createReplaceableCompositeType(
 649     unsigned Tag, StringRef Name, DIScope *Scope, DIFile *F, unsigned Line,
 650     unsigned RuntimeLang, uint64_t SizeInBits, uint32_t AlignInBits,
 651     DINode::DIFlags Flags, StringRef UniqueIdentifier,
 652     DINodeArray Annotations) {
 653   auto *RetTy =
 654       DICompositeType::getTemporary(
 655           VMContext, Tag, Name, F, Line, getNonCompileUnitScope(Scope), nullptr,
 656           SizeInBits, AlignInBits, 0, Flags, nullptr, RuntimeLang, nullptr,
 657           nullptr, UniqueIdentifier, nullptr, nullptr, nullptr, nullptr,
 658           nullptr, Annotations)
 659           .release();
 660   trackIfUnresolved(RetTy);
 661   return RetTy;
 662 }
 663
 664 DINodeArray DIBuilder::getOrCreateArray(ArrayRef<Metadata *> Elements) {
 665   return MDTuple::get(VMContext, Elements);
 666 }
 667
 668 DIMacroNodeArray
 669 DIBuilder::getOrCreateMacroArray(ArrayRef<Metadata *> Elements) {
 670   return MDTuple::get(VMContext, Elements);
 671 }
 672
 673 DITypeRefArray DIBuilder::getOrCreateTypeArray(ArrayRef<Metadata *> Elements) {
 674   SmallVector<llvm::Metadata *, 16> Elts;
 675   for (Metadata *E : Elements) {
 676     if (isa_and_nonnull<MDNode>(E))
 677       Elts.push_back(cast<DIType>(E));
 678     else
 679       Elts.push_back(E);
 680   }
 681   return DITypeRefArray(MDNode::get(VMContext, Elts));
 682 }
 683
 684 DISubrange *DIBuilder::getOrCreateSubrange(int64_t Lo, int64_t Count) {
 685   auto *LB = ConstantAsMetadata::get(
 686       ConstantInt::getSigned(Type::getInt64Ty(VMContext), Lo));
 687   auto *CountNode = ConstantAsMetadata::get(
 688       ConstantInt::getSigned(Type::getInt64Ty(VMContext), Count));
 689   return DISubrange::get(VMContext, CountNode, LB, nullptr, nullptr);
 690 }
 691
 692 DISubrange *DIBuilder::getOrCreateSubrange(int64_t Lo, Metadata *CountNode) {
 693   auto *LB = ConstantAsMetadata::get(
 694       ConstantInt::getSigned(Type::getInt64Ty(VMContext), Lo));
 695   return DISubrange::get(VMContext, CountNode, LB, nullptr, nullptr);
 696 }
 697
 698 DISubrange *DIBuilder::getOrCreateSubrange(Metadata *CountNode, Metadata *LB,
 699                                            Metadata *UB, Metadata *Stride) {
 700   return DISubrange::get(VMContext, CountNode, LB, UB, Stride);
 701 }
 702
 703 DIGenericSubrange *DIBuilder::getOrCreateGenericSubrange(
 704     DIGenericSubrange::BoundType CountNode, DIGenericSubrange::BoundType LB,
 705     DIGenericSubrange::BoundType UB, DIGenericSubrange::BoundType Stride) {
 706   auto ConvToMetadata = [&](DIGenericSubrange::BoundType Bound) -> Metadata * {
 707     return isa<DIExpression *>(Bound) ? (Metadata *)cast<DIExpression *>(Bound)
 708                                       : (Metadata *)cast<DIVariable *>(Bound);
 709   };
 710   return DIGenericSubrange::get(VMContext, ConvToMetadata(CountNode),
 711                                 ConvToMetadata(LB), ConvToMetadata(UB),
 712                                 ConvToMetadata(Stride));
 713 }
 714
 715 static void checkGlobalVariableScope(DIScope *Context) {
 716 #ifndef NDEBUG
 717   if (auto *CT =
 718           dyn_cast_or_null<DICompositeType>(getNonCompileUnitScope(Context)))
 719     assert(CT->getIdentifier().empty() &&
 720            "Context of a global variable should not be a type with identifier");
 721 #endif
 722 }
 723
 724 DIGlobalVariableExpression *DIBuilder::createGlobalVariableExpression(
 725     DIScope *Context, StringRef Name, StringRef LinkageName, DIFile *F,
 726     unsigned LineNumber, DIType *Ty, bool IsLocalToUnit, bool isDefined,
 727     DIExpression *Expr, MDNode *Decl, MDTuple *TemplateParams,
 728     uint32_t AlignInBits, DINodeArray Annotations) {
 729   checkGlobalVariableScope(Context);
 730
 731   auto *GV = DIGlobalVariable::getDistinct(
 732       VMContext, cast_or_null<DIScope>(Context), Name, LinkageName, F,
 733       LineNumber, Ty, IsLocalToUnit, isDefined,
 734       cast_or_null<DIDerivedType>(Decl), TemplateParams, AlignInBits,
 735       Annotations);
 736   if (!Expr)
 737     Expr = createExpression();
 738   auto *N = DIGlobalVariableExpression::get(VMContext, GV, Expr);
 739   AllGVs.push_back(N);
 740   return N;
 741 }
 742
 743 DIGlobalVariable *DIBuilder::createTempGlobalVariableFwdDecl(
 744     DIScope *Context, StringRef Name, StringRef LinkageName, DIFile *F,
 745     unsigned LineNumber, DIType *Ty, bool IsLocalToUnit, MDNode *Decl,
 746     MDTuple *TemplateParams, uint32_t AlignInBits) {
 747   checkGlobalVariableScope(Context);
 748
 749   return DIGlobalVariable::getTemporary(
 750              VMContext, cast_or_null<DIScope>(Context), Name, LinkageName, F,
 751              LineNumber, Ty, IsLocalToUnit, false,
 752              cast_or_null<DIDerivedType>(Decl), TemplateParams, AlignInBits,
 753              nullptr)
 754       .release();
 755 }
 756
 757 static DILocalVariable *createLocalVariable(
 758     LLVMContext &VMContext,
 759     SmallVectorImpl<TrackingMDNodeRef> &PreservedNodes,
 760     DIScope *Context, StringRef Name, unsigned ArgNo, DIFile *File,
 761     unsigned LineNo, DIType *Ty, bool AlwaysPreserve, DINode::DIFlags Flags,
 762     uint32_t AlignInBits, DINodeArray Annotations = nullptr) {
 763   // FIXME: Why doesn't this check for a subprogram or lexical block (AFAICT
 764   // the only valid scopes)?
 765   auto *Scope = cast<DILocalScope>(Context);
 766   auto *Node = DILocalVariable::get(VMContext, Scope, Name, File, LineNo, Ty,
 767                                     ArgNo, Flags, AlignInBits, Annotations);
 768   if (AlwaysPreserve) {
 769     // The optimizer may remove local variables. If there is an interest
 770     // to preserve variable info in such situation then stash it in a
 771     // named mdnode.
 772     PreservedNodes.emplace_back(Node);
 773   }
 774   return Node;
 775 }
 776
 777 DILocalVariable *DIBuilder::createAutoVariable(DIScope *Scope, StringRef Name,
 778                                                DIFile *File, unsigned LineNo,
 779                                                DIType *Ty, bool AlwaysPreserve,
 780                                                DINode::DIFlags Flags,
 781                                                uint32_t AlignInBits) {
 782   assert(Scope && isa<DILocalScope>(Scope) &&
 783          "Unexpected scope for a local variable.");
 784   return createLocalVariable(
 785       VMContext, getSubprogramNodesTrackingVector(Scope), Scope, Name,
 786       /* ArgNo */ 0, File, LineNo, Ty, AlwaysPreserve, Flags, AlignInBits);
 787 }
 788
 789 DILocalVariable *DIBuilder::createParameterVariable(
 790     DIScope *Scope, StringRef Name, unsigned ArgNo, DIFile *File,
 791     unsigned LineNo, DIType *Ty, bool AlwaysPreserve, DINode::DIFlags Flags,
 792     DINodeArray Annotations) {
 793   assert(ArgNo && "Expected non-zero argument number for parameter");
 794   assert(Scope && isa<DILocalScope>(Scope) &&
 795          "Unexpected scope for a local variable.");
 796   return createLocalVariable(
 797       VMContext, getSubprogramNodesTrackingVector(Scope), Scope, Name, ArgNo,
 798       File, LineNo, Ty, AlwaysPreserve, Flags, /*AlignInBits=*/0, Annotations);
 799 }
 800
 801 DILabel *DIBuilder::createLabel(DIScope *Context, StringRef Name, DIFile *File,
 802                                  unsigned LineNo, bool AlwaysPreserve) {
 803   auto *Scope = cast<DILocalScope>(Context);
 804   auto *Node = DILabel::get(VMContext, Scope, Name, File, LineNo);
 805
 806   if (AlwaysPreserve) {
 807     /// The optimizer may remove labels. If there is an interest
 808     /// to preserve label info in such situation then append it to
 809     /// the list of retained nodes of the DISubprogram.
 810     getSubprogramNodesTrackingVector(Scope).emplace_back(Node);
 811   }
 812   return Node;
 813 }
 814
 815 DIExpression *DIBuilder::createExpression(ArrayRef<uint64_t> Addr) {
 816   return DIExpression::get(VMContext, Addr);
 817 }
 818
 819 template <class... Ts>
 820 static DISubprogram *getSubprogram(bool IsDistinct, Ts &&...Args) {
 821   if (IsDistinct)
 822     return DISubprogram::getDistinct(std::forward<Ts>(Args)...);
 823   return DISubprogram::get(std::forward<Ts>(Args)...);
 824 }
 825
 826 DISubprogram *DIBuilder::createFunction(
 827     DIScope *Context, StringRef Name, StringRef LinkageName, DIFile *File,
 828     unsigned LineNo, DISubroutineType *Ty, unsigned ScopeLine,
 829     DINode::DIFlags Flags, DISubprogram::DISPFlags SPFlags,
 830     DITemplateParameterArray TParams, DISubprogram *Decl,
 831     DITypeArray ThrownTypes, DINodeArray Annotations,
 832     StringRef TargetFuncName) {
 833   bool IsDefinition = SPFlags & DISubprogram::SPFlagDefinition;
 834   auto *Node = getSubprogram(
 835       /*IsDistinct=*/IsDefinition, VMContext, getNonCompileUnitScope(Context),
 836       Name, LinkageName, File, LineNo, Ty, ScopeLine, nullptr, 0, 0, Flags,
 837       SPFlags, IsDefinition ? CUNode : nullptr, TParams, Decl, nullptr,
 838       ThrownTypes, Annotations, TargetFuncName);
 839
 840   if (IsDefinition)
 841     AllSubprograms.push_back(Node);
 842   trackIfUnresolved(Node);
 843   return Node;
 844 }
 845
 846 DISubprogram *DIBuilder::createTempFunctionFwdDecl(
 847     DIScope *Context, StringRef Name, StringRef LinkageName, DIFile *File,
 848     unsigned LineNo, DISubroutineType *Ty, unsigned ScopeLine,
 849     DINode::DIFlags Flags, DISubprogram::DISPFlags SPFlags,
 850     DITemplateParameterArray TParams, DISubprogram *Decl,
 851     DITypeArray ThrownTypes) {
 852   bool IsDefinition = SPFlags & DISubprogram::SPFlagDefinition;
 853   return DISubprogram::getTemporary(VMContext, getNonCompileUnitScope(Context),
 854                                     Name, LinkageName, File, LineNo, Ty,
 855                                     ScopeLine, nullptr, 0, 0, Flags, SPFlags,
 856                                     IsDefinition ? CUNode : nullptr, TParams,
 857                                     Decl, nullptr, ThrownTypes)
 858       .release();
 859 }
 860
 861 DISubprogram *DIBuilder::createMethod(
 862     DIScope *Context, StringRef Name, StringRef LinkageName, DIFile *F,
 863     unsigned LineNo, DISubroutineType *Ty, unsigned VIndex, int ThisAdjustment,
 864     DIType *VTableHolder, DINode::DIFlags Flags,
 865     DISubprogram::DISPFlags SPFlags, DITemplateParameterArray TParams,
 866     DITypeArray ThrownTypes) {
 867   assert(getNonCompileUnitScope(Context) &&
 868          "Methods should have both a Context and a context that isn't "
 869          "the compile unit.");
 870   // FIXME: Do we want to use different scope/lines?
 871   bool IsDefinition = SPFlags & DISubprogram::SPFlagDefinition;
 872   auto *SP = getSubprogram(
 873       /*IsDistinct=*/IsDefinition, VMContext, cast<DIScope>(Context), Name,
 874       LinkageName, F, LineNo, Ty, LineNo, VTableHolder, VIndex, ThisAdjustment,
 875       Flags, SPFlags, IsDefinition ? CUNode : nullptr, TParams, nullptr,
 876       nullptr, ThrownTypes);
 877
 878   if (IsDefinition)
 879     AllSubprograms.push_back(SP);
 880   trackIfUnresolved(SP);
 881   return SP;
 882 }
 883
 884 DICommonBlock *DIBuilder::createCommonBlock(DIScope *Scope,
 885                                             DIGlobalVariable *Decl,
 886                                             StringRef Name, DIFile *File,
 887                                             unsigned LineNo) {
 888   return DICommonBlock::get(VMContext, Scope, Decl, Name, File, LineNo);
 889 }
 890
 891 DINamespace *DIBuilder::createNameSpace(DIScope *Scope, StringRef Name,
 892                                         bool ExportSymbols) {
 893
 894   // It is okay to *not* make anonymous top-level namespaces distinct, because
 895   // all nodes that have an anonymous namespace as their parent scope are
 896   // guaranteed to be unique and/or are linked to their containing
 897   // DICompileUnit. This decision is an explicit tradeoff of link time versus
 898   // memory usage versus code simplicity and may get revisited in the future.
 899   return DINamespace::get(VMContext, getNonCompileUnitScope(Scope), Name,
 900                           ExportSymbols);
 901 }
 902
 903 DIModule *DIBuilder::createModule(DIScope *Scope, StringRef Name,
 904                                   StringRef ConfigurationMacros,
 905                                   StringRef IncludePath, StringRef APINotesFile,
 906                                   DIFile *File, unsigned LineNo, bool IsDecl) {
 907   return DIModule::get(VMContext, File, getNonCompileUnitScope(Scope), Name,
 908                        ConfigurationMacros, IncludePath, APINotesFile, LineNo,
 909                        IsDecl);
 910 }
 911
 912 DILexicalBlockFile *DIBuilder::createLexicalBlockFile(DIScope *Scope,
 913                                                       DIFile *File,
 914                                                       unsigned Discriminator) {
 915   return DILexicalBlockFile::get(VMContext, Scope, File, Discriminator);
 916 }
 917
 918 DILexicalBlock *DIBuilder::createLexicalBlock(DIScope *Scope, DIFile *File,
 919                                               unsigned Line, unsigned Col) {
 920   // Make these distinct, to avoid merging two lexical blocks on the same
 921   // file/line/column.
 922   return DILexicalBlock::getDistinct(VMContext, getNonCompileUnitScope(Scope),
 923                                      File, Line, Col);
 924 }
 925
 926 Instruction *DIBuilder::insertDeclare(Value *Storage, DILocalVariable *VarInfo,
 927                                       DIExpression *Expr, const DILocation *DL,
 928                                       Instruction *InsertBefore) {
 929   return insertDeclare(Storage, VarInfo, Expr, DL, InsertBefore->getParent(),
 930                        InsertBefore);
 931 }
 932
 933 Instruction *DIBuilder::insertDeclare(Value *Storage, DILocalVariable *VarInfo,
 934                                       DIExpression *Expr, const DILocation *DL,
 935                                       BasicBlock *InsertAtEnd) {
 936   // If this block already has a terminator then insert this intrinsic before
 937   // the terminator. Otherwise, put it at the end of the block.
 938   Instruction *InsertBefore = InsertAtEnd->getTerminator();
 939   return insertDeclare(Storage, VarInfo, Expr, DL, InsertAtEnd, InsertBefore);
 940 }
 941
 942 DbgAssignIntrinsic *
 943 DIBuilder::insertDbgAssign(Instruction *LinkedInstr, Value *Val,
 944                            DILocalVariable *SrcVar, DIExpression *ValExpr,
 945                            Value *Addr, DIExpression *AddrExpr,
 946                            const DILocation *DL) {
 947   LLVMContext &Ctx = LinkedInstr->getContext();
 948   Module *M = LinkedInstr->getModule();
 949   if (!AssignFn)
 950     AssignFn = Intrinsic::getDeclaration(M, Intrinsic::dbg_assign);
 951
 952   auto *Link = LinkedInstr->getMetadata(LLVMContext::MD_DIAssignID);
 953   assert(Link && "Linked instruction must have DIAssign metadata attached");
 954
 955   std::array<Value *, 6> Args = {
 956       MetadataAsValue::get(Ctx, ValueAsMetadata::get(Val)),
 957       MetadataAsValue::get(Ctx, SrcVar),
 958       MetadataAsValue::get(Ctx, ValExpr),
 959       MetadataAsValue::get(Ctx, Link),
 960       MetadataAsValue::get(Ctx, ValueAsMetadata::get(Addr)),
 961       MetadataAsValue::get(Ctx, AddrExpr),
 962   };
 963
 964   IRBuilder<> B(Ctx);
 965   B.SetCurrentDebugLocation(DL);
 966
 967   auto *DVI = cast<DbgAssignIntrinsic>(B.CreateCall(AssignFn, Args));
 968   DVI->insertAfter(LinkedInstr);
 969   return DVI;
 970 }
 971
 972 Instruction *DIBuilder::insertLabel(DILabel *LabelInfo, const DILocation *DL,
 973                                     Instruction *InsertBefore) {
 974   return insertLabel(LabelInfo, DL,
 975                      InsertBefore ? InsertBefore->getParent() : nullptr,
 976                      InsertBefore);
 977 }
 978
 979 Instruction *DIBuilder::insertLabel(DILabel *LabelInfo, const DILocation *DL,
 980                                     BasicBlock *InsertAtEnd) {
 981   return insertLabel(LabelInfo, DL, InsertAtEnd, nullptr);
 982 }
 983
 984 Instruction *DIBuilder::insertDbgValueIntrinsic(Value *V,
 985                                                 DILocalVariable *VarInfo,
 986                                                 DIExpression *Expr,
 987                                                 const DILocation *DL,
 988                                                 Instruction *InsertBefore) {
 989   return insertDbgValueIntrinsic(
 990       V, VarInfo, Expr, DL, InsertBefore ? InsertBefore->getParent() : nullptr,
 991       InsertBefore);
 992 }
 993
 994 Instruction *DIBuilder::insertDbgValueIntrinsic(Value *V,
 995                                                 DILocalVariable *VarInfo,
 996                                                 DIExpression *Expr,
 997                                                 const DILocation *DL,
 998                                                 BasicBlock *InsertAtEnd) {
 999   return insertDbgValueIntrinsic(V, VarInfo, Expr, DL, InsertAtEnd, nullptr);
1000 }
1001
1002 /// Initialize IRBuilder for inserting dbg.declare and dbg.value intrinsics.
1003 /// This abstracts over the various ways to specify an insert position.
1004 static void initIRBuilder(IRBuilder<> &Builder, const DILocation *DL,
1005                           BasicBlock *InsertBB, Instruction *InsertBefore) {
1006   if (InsertBefore)
1007     Builder.SetInsertPoint(InsertBefore);
1008   else if (InsertBB)
1009     Builder.SetInsertPoint(InsertBB);
1010   Builder.SetCurrentDebugLocation(DL);
1011 }
1012
1013 static Value *getDbgIntrinsicValueImpl(LLVMContext &VMContext, Value *V) {
1014   assert(V && "no value passed to dbg intrinsic");
1015   return MetadataAsValue::get(VMContext, ValueAsMetadata::get(V));
1016 }
1017
1018 static Function *getDeclareIntrin(Module &M) {
1019   return Intrinsic::getDeclaration(&M, Intrinsic::dbg_declare);
1020 }
1021
1022 Instruction *DIBuilder::insertDbgValueIntrinsic(
1023     llvm::Value *Val, DILocalVariable *VarInfo, DIExpression *Expr,
1024     const DILocation *DL, BasicBlock *InsertBB, Instruction *InsertBefore) {
1025   if (!ValueFn)
1026     ValueFn = Intrinsic::getDeclaration(&M, Intrinsic::dbg_value);
1027   return insertDbgIntrinsic(ValueFn, Val, VarInfo, Expr, DL, InsertBB,
1028                             InsertBefore);
1029 }
1030
1031 Instruction *DIBuilder::insertDeclare(Value *Storage, DILocalVariable *VarInfo,
1032                                       DIExpression *Expr, const DILocation *DL,
1033                                       BasicBlock *InsertBB,
1034                                       Instruction *InsertBefore) {
1035   assert(VarInfo && "empty or invalid DILocalVariable* passed to dbg.declare");
1036   assert(DL && "Expected debug loc");
1037   assert(DL->getScope()->getSubprogram() ==
1038              VarInfo->getScope()->getSubprogram() &&
1039          "Expected matching subprograms");
1040   if (!DeclareFn)
1041     DeclareFn = getDeclareIntrin(M);
1042
1043   trackIfUnresolved(VarInfo);
1044   trackIfUnresolved(Expr);
1045   Value *Args[] = {getDbgIntrinsicValueImpl(VMContext, Storage),
1046                    MetadataAsValue::get(VMContext, VarInfo),
1047                    MetadataAsValue::get(VMContext, Expr)};
1048
1049   IRBuilder<> B(DL->getContext());
1050   initIRBuilder(B, DL, InsertBB, InsertBefore);
1051   return B.CreateCall(DeclareFn, Args);
1052 }
1053
1054 Instruction *DIBuilder::insertDbgIntrinsic(llvm::Function *IntrinsicFn,
1055                                            Value *V, DILocalVariable *VarInfo,
1056                                            DIExpression *Expr,
1057                                            const DILocation *DL,
1058                                            BasicBlock *InsertBB,
1059                                            Instruction *InsertBefore) {
1060   assert(IntrinsicFn && "must pass a non-null intrinsic function");
1061   assert(V && "must pass a value to a dbg intrinsic");
1062   assert(VarInfo &&
1063          "empty or invalid DILocalVariable* passed to debug intrinsic");
1064   assert(DL && "Expected debug loc");
1065   assert(DL->getScope()->getSubprogram() ==
1066              VarInfo->getScope()->getSubprogram() &&
1067          "Expected matching subprograms");
1068
1069   trackIfUnresolved(VarInfo);
1070   trackIfUnresolved(Expr);
1071   Value *Args[] = {getDbgIntrinsicValueImpl(VMContext, V),
1072                    MetadataAsValue::get(VMContext, VarInfo),
1073                    MetadataAsValue::get(VMContext, Expr)};
1074
1075   IRBuilder<> B(DL->getContext());
1076   initIRBuilder(B, DL, InsertBB, InsertBefore);
1077   return B.CreateCall(IntrinsicFn, Args);
1078 }
1079
1080 Instruction *DIBuilder::insertLabel(DILabel *LabelInfo, const DILocation *DL,
1081                                     BasicBlock *InsertBB,
1082                                     Instruction *InsertBefore) {
1083   assert(LabelInfo && "empty or invalid DILabel* passed to dbg.label");
1084   assert(DL && "Expected debug loc");
1085   assert(DL->getScope()->getSubprogram() ==
1086              LabelInfo->getScope()->getSubprogram() &&
1087          "Expected matching subprograms");
1088   if (!LabelFn)
1089     LabelFn = Intrinsic::getDeclaration(&M, Intrinsic::dbg_label);
1090
1091   trackIfUnresolved(LabelInfo);
1092   Value *Args[] = {MetadataAsValue::get(VMContext, LabelInfo)};
1093
1094   IRBuilder<> B(DL->getContext());
1095   initIRBuilder(B, DL, InsertBB, InsertBefore);
1096   return B.CreateCall(LabelFn, Args);
1097 }
1098
1099 void DIBuilder::replaceVTableHolder(DICompositeType *&T, DIType *VTableHolder) {
1100   {
1101     TypedTrackingMDRef<DICompositeType> N(T);
1102     N->replaceVTableHolder(VTableHolder);
1103     T = N.get();
1104   }
1105
1106   // If this didn't create a self-reference, just return.
1107   if (T != VTableHolder)
1108     return;
1109
1110   // Look for unresolved operands.  T will drop RAUW support, orphaning any
1111   // cycles underneath it.
1112   if (T->isResolved())
1113     for (const MDOperand &O : T->operands())
1114       if (auto *N = dyn_cast_or_null<MDNode>(O))
1115         trackIfUnresolved(N);
1116 }
1117
1118 void DIBuilder::replaceArrays(DICompositeType *&T, DINodeArray Elements,
1119                               DINodeArray TParams) {
1120   {
1121     TypedTrackingMDRef<DICompositeType> N(T);
1122     if (Elements)
1123       N->replaceElements(Elements);
1124     if (TParams)
1125       N->replaceTemplateParams(DITemplateParameterArray(TParams));
1126     T = N.get();
1127   }
1128
1129   // If T isn't resolved, there's no problem.
1130   if (!T->isResolved())
1131     return;
1132
1133   // If T is resolved, it may be due to a self-reference cycle.  Track the
1134   // arrays explicitly if they're unresolved, or else the cycles will be
1135   // orphaned.
1136   if (Elements)
1137     trackIfUnresolved(Elements.get());
1138   if (TParams)
1139     trackIfUnresolved(TParams.get());
1140 }