contrib/llvm/lib/IR/DIBuilder.cpp

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