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