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