lib/IR/DIBuilder.cpp

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