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