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