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   MDSubprogramArray 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       DIArray 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 MDScope *getNonCompileUnitScope(MDScope *N) {
 120   if (!N || isa<MDCompileUnit>(N))
 121     return nullptr;
 122   return cast<MDScope>(N);
 123 }
 124
 125 MDCompileUnit *DIBuilder::createCompileUnit(
 126     unsigned Lang, StringRef Filename, StringRef Directory, StringRef Producer,
 127     bool isOptimized, StringRef Flags, unsigned RunTimeVer, StringRef SplitName,
 128     DebugEmissionKind Kind, 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 MDCompileUnit 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   MDCompileUnit *CUNode = MDCompileUnit::get(
 147       VMContext, Lang, MDFile::get(VMContext, Filename, Directory), Producer,
 148       isOptimized, Flags, RunTimeVer, SplitName, Kind, TempEnumTypes.get(),
 149       TempRetainTypes.get(), TempSubprograms.get(), TempGVs.get(),
 150       TempImportedModules.get());
 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 MDImportedEntity*
 167 createImportedModule(LLVMContext &C, dwarf::Tag Tag, MDScope* Context,
 168                      Metadata *NS, unsigned Line, StringRef Name,
 169                      SmallVectorImpl<TrackingMDNodeRef> &AllImportedModules) {
 170   auto *M =
 171       MDImportedEntity::get(C, Tag, Context, DebugNodeRef(NS), Line, Name);
 172   AllImportedModules.emplace_back(M);
 173   return M;
 174 }
 175
 176 MDImportedEntity* DIBuilder::createImportedModule(MDScope* Context,
 177                                                  MDNamespace* NS,
 178                                                  unsigned Line) {
 179   return ::createImportedModule(VMContext, dwarf::DW_TAG_imported_module,
 180                                 Context, NS, Line, StringRef(), AllImportedModules);
 181 }
 182
 183 MDImportedEntity* DIBuilder::createImportedModule(MDScope* Context,
 184                                                  MDImportedEntity* NS,
 185                                                  unsigned Line) {
 186   return ::createImportedModule(VMContext, dwarf::DW_TAG_imported_module,
 187                                 Context, NS, Line, StringRef(), AllImportedModules);
 188 }
 189
 190 MDImportedEntity *DIBuilder::createImportedDeclaration(MDScope *Context,
 191                                                        DebugNode *Decl,
 192                                                        unsigned Line,
 193                                                        StringRef Name) {
 194   // Make sure to use the unique identifier based metadata reference for
 195   // types that have one.
 196   return ::createImportedModule(VMContext, dwarf::DW_TAG_imported_declaration,
 197                                 Context, DebugNodeRef::get(Decl), Line, Name,
 198                                 AllImportedModules);
 199 }
 200
 201 MDFile* DIBuilder::createFile(StringRef Filename, StringRef Directory) {
 202   return MDFile::get(VMContext, Filename, Directory);
 203 }
 204
 205 MDEnumerator *DIBuilder::createEnumerator(StringRef Name, int64_t Val) {
 206   assert(!Name.empty() && "Unable to create enumerator without name");
 207   return MDEnumerator::get(VMContext, Val, Name);
 208 }
 209
 210 MDBasicType *DIBuilder::createUnspecifiedType(StringRef Name) {
 211   assert(!Name.empty() && "Unable to create type without name");
 212   return MDBasicType::get(VMContext, dwarf::DW_TAG_unspecified_type, Name);
 213 }
 214
 215 MDBasicType *DIBuilder::createNullPtrType() {
 216   return createUnspecifiedType("decltype(nullptr)");
 217 }
 218
 219 MDBasicType *DIBuilder::createBasicType(StringRef Name, uint64_t SizeInBits,
 220                                         uint64_t AlignInBits,
 221                                         unsigned Encoding) {
 222   assert(!Name.empty() && "Unable to create type without name");
 223   return MDBasicType::get(VMContext, dwarf::DW_TAG_base_type, Name, SizeInBits,
 224                           AlignInBits, Encoding);
 225 }
 226
 227 MDDerivedType *DIBuilder::createQualifiedType(unsigned Tag, MDType *FromTy) {
 228   return MDDerivedType::get(VMContext, Tag, "", nullptr, 0, nullptr,
 229                             MDTypeRef::get(FromTy), 0, 0, 0, 0);
 230 }
 231
 232 MDDerivedType *DIBuilder::createPointerType(MDType *PointeeTy,
 233                                             uint64_t SizeInBits,
 234                                             uint64_t AlignInBits,
 235                                             StringRef Name) {
 236   // FIXME: Why is there a name here?
 237   return MDDerivedType::get(VMContext, dwarf::DW_TAG_pointer_type, Name,
 238                             nullptr, 0, nullptr, MDTypeRef::get(PointeeTy),
 239                             SizeInBits, AlignInBits, 0, 0);
 240 }
 241
 242 MDDerivedType *DIBuilder::createMemberPointerType(MDType *PointeeTy,
 243                                                   MDType *Base,
 244                                                   uint64_t SizeInBits,
 245                                                   uint64_t AlignInBits) {
 246   return MDDerivedType::get(VMContext, dwarf::DW_TAG_ptr_to_member_type, "",
 247                             nullptr, 0, nullptr, MDTypeRef::get(PointeeTy),
 248                             SizeInBits, AlignInBits, 0, 0, MDTypeRef::get(Base));
 249 }
 250
 251 MDDerivedType *DIBuilder::createReferenceType(unsigned Tag, MDType *RTy) {
 252   assert(RTy && "Unable to create reference type");
 253   return MDDerivedType::get(VMContext, Tag, "", nullptr, 0, nullptr,
 254                             MDTypeRef::get(RTy), 0, 0, 0, 0);
 255 }
 256
 257 MDDerivedType *DIBuilder::createTypedef(MDType *Ty, StringRef Name,
 258                                         MDFile *File, unsigned LineNo,
 259                                         MDScope *Context) {
 260   return MDDerivedType::get(VMContext, dwarf::DW_TAG_typedef, Name, File,
 261                             LineNo,
 262                             MDScopeRef::get(getNonCompileUnitScope(Context)),
 263                             MDTypeRef::get(Ty), 0, 0, 0, 0);
 264 }
 265
 266 MDDerivedType *DIBuilder::createFriend(MDType *Ty, MDType *FriendTy) {
 267   assert(Ty && "Invalid type!");
 268   assert(FriendTy && "Invalid friend type!");
 269   return MDDerivedType::get(VMContext, dwarf::DW_TAG_friend, "", nullptr, 0,
 270                             MDTypeRef::get(Ty), MDTypeRef::get(FriendTy), 0, 0,
 271                             0, 0);
 272 }
 273
 274 MDDerivedType *DIBuilder::createInheritance(MDType *Ty, MDType *BaseTy,
 275                                             uint64_t BaseOffset,
 276                                             unsigned Flags) {
 277   assert(Ty && "Unable to create inheritance");
 278   return MDDerivedType::get(VMContext, dwarf::DW_TAG_inheritance, "", nullptr,
 279                             0, MDTypeRef::get(Ty), MDTypeRef::get(BaseTy), 0, 0,
 280                             BaseOffset, Flags);
 281 }
 282
 283 MDDerivedType *DIBuilder::createMemberType(MDScope *Scope, StringRef Name,
 284                                            MDFile *File, unsigned LineNumber,
 285                                            uint64_t SizeInBits,
 286                                            uint64_t AlignInBits,
 287                                            uint64_t OffsetInBits,
 288                                            unsigned Flags, MDType *Ty) {
 289   return MDDerivedType::get(
 290       VMContext, dwarf::DW_TAG_member, Name, File, LineNumber,
 291       MDScopeRef::get(getNonCompileUnitScope(Scope)), MDTypeRef::get(Ty),
 292       SizeInBits, AlignInBits, OffsetInBits, Flags);
 293 }
 294
 295 static ConstantAsMetadata *getConstantOrNull(Constant *C) {
 296   if (C)
 297     return ConstantAsMetadata::get(C);
 298   return nullptr;
 299 }
 300
 301 MDDerivedType *DIBuilder::createStaticMemberType(MDScope *Scope, StringRef Name,
 302                                                  MDFile *File,
 303                                                  unsigned LineNumber,
 304                                                  MDType *Ty, unsigned Flags,
 305                                                  llvm::Constant *Val) {
 306   Flags |= DebugNode::FlagStaticMember;
 307   return MDDerivedType::get(
 308       VMContext, dwarf::DW_TAG_member, Name, File, LineNumber,
 309       MDScopeRef::get(getNonCompileUnitScope(Scope)), MDTypeRef::get(Ty), 0, 0,
 310       0, Flags, getConstantOrNull(Val));
 311 }
 312
 313 MDDerivedType *DIBuilder::createObjCIVar(StringRef Name, MDFile *File,
 314                                          unsigned LineNumber,
 315                                          uint64_t SizeInBits,
 316                                          uint64_t AlignInBits,
 317                                          uint64_t OffsetInBits, unsigned Flags,
 318                                          MDType *Ty, MDNode *PropertyNode) {
 319   return MDDerivedType::get(
 320       VMContext, dwarf::DW_TAG_member, Name, File, LineNumber,
 321       MDScopeRef::get(getNonCompileUnitScope(File)), MDTypeRef::get(Ty),
 322       SizeInBits, AlignInBits, OffsetInBits, Flags, PropertyNode);
 323 }
 324
 325 MDObjCProperty *
 326 DIBuilder::createObjCProperty(StringRef Name, MDFile *File, unsigned LineNumber,
 327                               StringRef GetterName, StringRef SetterName,
 328                               unsigned PropertyAttributes, MDType *Ty) {
 329   return MDObjCProperty::get(VMContext, Name, File, LineNumber, GetterName,
 330                              SetterName, PropertyAttributes, Ty);
 331 }
 332
 333 MDTemplateTypeParameter *
 334 DIBuilder::createTemplateTypeParameter(MDScope *Context, StringRef Name,
 335                                        MDType *Ty) {
 336   assert((!Context || isa<MDCompileUnit>(Context)) && "Expected compile unit");
 337   return MDTemplateTypeParameter::get(VMContext, Name, MDTypeRef::get(Ty));
 338 }
 339
 340 static MDTemplateValueParameter *
 341 createTemplateValueParameterHelper(LLVMContext &VMContext, unsigned Tag,
 342                                    MDScope *Context, StringRef Name, MDType *Ty,
 343                                    Metadata *MD) {
 344   assert((!Context || isa<MDCompileUnit>(Context)) && "Expected compile unit");
 345   return MDTemplateValueParameter::get(VMContext, Tag, Name, MDTypeRef::get(Ty),
 346                                        MD);
 347 }
 348
 349 MDTemplateValueParameter *
 350 DIBuilder::createTemplateValueParameter(MDScope *Context, StringRef Name,
 351                                         MDType *Ty, Constant *Val) {
 352   return createTemplateValueParameterHelper(
 353       VMContext, dwarf::DW_TAG_template_value_parameter, Context, Name, Ty,
 354       getConstantOrNull(Val));
 355 }
 356
 357 MDTemplateValueParameter *
 358 DIBuilder::createTemplateTemplateParameter(MDScope *Context, StringRef Name,
 359                                            MDType *Ty, StringRef Val) {
 360   return createTemplateValueParameterHelper(
 361       VMContext, dwarf::DW_TAG_GNU_template_template_param, Context, Name, Ty,
 362       MDString::get(VMContext, Val));
 363 }
 364
 365 MDTemplateValueParameter *
 366 DIBuilder::createTemplateParameterPack(MDScope *Context, StringRef Name,
 367                                        MDType *Ty, DIArray Val) {
 368   return createTemplateValueParameterHelper(
 369       VMContext, dwarf::DW_TAG_GNU_template_parameter_pack, Context, Name, Ty,
 370       Val.get());
 371 }
 372
 373 MDCompositeType *DIBuilder::createClassType(
 374     MDScope *Context, StringRef Name, MDFile *File, unsigned LineNumber,
 375     uint64_t SizeInBits, uint64_t AlignInBits, uint64_t OffsetInBits,
 376     unsigned Flags, MDType *DerivedFrom, DIArray Elements, MDType *VTableHolder,
 377     MDNode *TemplateParams, StringRef UniqueIdentifier) {
 378   assert((!Context || isa<MDScope>(Context)) &&
 379          "createClassType should be called with a valid Context");
 380
 381   auto *R = MDCompositeType::get(
 382       VMContext, dwarf::DW_TAG_structure_type, Name, File, LineNumber,
 383       MDScopeRef::get(getNonCompileUnitScope(Context)),
 384       MDTypeRef::get(DerivedFrom), SizeInBits, AlignInBits, OffsetInBits, Flags,
 385       Elements, 0, MDTypeRef::get(VTableHolder),
 386       cast_or_null<MDTuple>(TemplateParams), UniqueIdentifier);
 387   if (!UniqueIdentifier.empty())
 388     retainType(R);
 389   trackIfUnresolved(R);
 390   return R;
 391 }
 392
 393 MDCompositeType *DIBuilder::createStructType(
 394     MDScope *Context, StringRef Name, MDFile *File, unsigned LineNumber,
 395     uint64_t SizeInBits, uint64_t AlignInBits, unsigned Flags,
 396     MDType *DerivedFrom, DIArray Elements, unsigned RunTimeLang,
 397     MDType *VTableHolder, StringRef UniqueIdentifier) {
 398   auto *R = MDCompositeType::get(
 399       VMContext, dwarf::DW_TAG_structure_type, Name, File, LineNumber,
 400       MDScopeRef::get(getNonCompileUnitScope(Context)),
 401       MDTypeRef::get(DerivedFrom), SizeInBits, AlignInBits, 0, Flags, Elements,
 402       RunTimeLang, MDTypeRef::get(VTableHolder), nullptr, UniqueIdentifier);
 403   if (!UniqueIdentifier.empty())
 404     retainType(R);
 405   trackIfUnresolved(R);
 406   return R;
 407 }
 408
 409 MDCompositeType* DIBuilder::createUnionType(MDScope * Scope, StringRef Name,
 410                                            MDFile* File, unsigned LineNumber,
 411                                            uint64_t SizeInBits,
 412                                            uint64_t AlignInBits, unsigned Flags,
 413                                            DIArray Elements,
 414                                            unsigned RunTimeLang,
 415                                            StringRef UniqueIdentifier) {
 416   auto *R = MDCompositeType::get(
 417       VMContext, dwarf::DW_TAG_union_type, Name, File, LineNumber,
 418       MDScopeRef::get(getNonCompileUnitScope(Scope)), nullptr, SizeInBits,
 419       AlignInBits, 0, Flags, Elements, RunTimeLang, nullptr, nullptr,
 420       UniqueIdentifier);
 421   if (!UniqueIdentifier.empty())
 422     retainType(R);
 423   trackIfUnresolved(R);
 424   return R;
 425 }
 426
 427 MDSubroutineType *DIBuilder::createSubroutineType(MDFile *File,
 428                                                   DITypeArray ParameterTypes,
 429                                                   unsigned Flags) {
 430   return MDSubroutineType::get(VMContext, Flags, ParameterTypes);
 431 }
 432
 433 MDCompositeType *DIBuilder::createEnumerationType(
 434     MDScope *Scope, StringRef Name, MDFile *File, unsigned LineNumber,
 435     uint64_t SizeInBits, uint64_t AlignInBits, DIArray Elements,
 436     MDType *UnderlyingType, StringRef UniqueIdentifier) {
 437   auto *CTy = MDCompositeType::get(
 438       VMContext, dwarf::DW_TAG_enumeration_type, Name, File, LineNumber,
 439       MDScopeRef::get(getNonCompileUnitScope(Scope)),
 440       MDTypeRef::get(UnderlyingType), SizeInBits, AlignInBits, 0, 0, Elements,
 441       0, nullptr, nullptr, UniqueIdentifier);
 442   AllEnumTypes.push_back(CTy);
 443   if (!UniqueIdentifier.empty())
 444     retainType(CTy);
 445   trackIfUnresolved(CTy);
 446   return CTy;
 447 }
 448
 449 MDCompositeType *DIBuilder::createArrayType(uint64_t Size, uint64_t AlignInBits,
 450                                             MDType *Ty, DIArray Subscripts) {
 451   auto *R = MDCompositeType::get(VMContext, dwarf::DW_TAG_array_type, "",
 452                                  nullptr, 0, nullptr, MDTypeRef::get(Ty), Size,
 453                                  AlignInBits, 0, 0, Subscripts, 0, nullptr);
 454   trackIfUnresolved(R);
 455   return R;
 456 }
 457
 458 MDCompositeType *DIBuilder::createVectorType(uint64_t Size,
 459                                              uint64_t AlignInBits, MDType *Ty,
 460                                              DIArray Subscripts) {
 461   auto *R =
 462       MDCompositeType::get(VMContext, dwarf::DW_TAG_array_type, "", nullptr, 0,
 463                            nullptr, MDTypeRef::get(Ty), Size, AlignInBits, 0,
 464                            DebugNode::FlagVector, Subscripts, 0, nullptr);
 465   trackIfUnresolved(R);
 466   return R;
 467 }
 468
 469 static MDType *createTypeWithFlags(LLVMContext &Context, MDType *Ty,
 470                                    unsigned FlagsToSet) {
 471   auto NewTy = Ty->clone();
 472   NewTy->setFlags(NewTy->getFlags() | FlagsToSet);
 473   return MDNode::replaceWithUniqued(std::move(NewTy));
 474 }
 475
 476 MDType *DIBuilder::createArtificialType(MDType *Ty) {
 477   // FIXME: Restrict this to the nodes where it's valid.
 478   if (Ty->isArtificial())
 479     return Ty;
 480   return createTypeWithFlags(VMContext, Ty, DebugNode::FlagArtificial);
 481 }
 482
 483 MDType *DIBuilder::createObjectPointerType(MDType *Ty) {
 484   // FIXME: Restrict this to the nodes where it's valid.
 485   if (Ty->isObjectPointer())
 486     return Ty;
 487   unsigned Flags = DebugNode::FlagObjectPointer | DebugNode::FlagArtificial;
 488   return createTypeWithFlags(VMContext, Ty, Flags);
 489 }
 490
 491 void DIBuilder::retainType(MDType *T) {
 492   assert(T && "Expected non-null type");
 493   AllRetainTypes.emplace_back(T);
 494 }
 495
 496 MDBasicType *DIBuilder::createUnspecifiedParameter() { return nullptr; }
 497
 498 MDCompositeType*
 499 DIBuilder::createForwardDecl(unsigned Tag, StringRef Name, MDScope * Scope,
 500                              MDFile* F, unsigned Line, unsigned RuntimeLang,
 501                              uint64_t SizeInBits, uint64_t AlignInBits,
 502                              StringRef UniqueIdentifier) {
 503   // FIXME: Define in terms of createReplaceableForwardDecl() by calling
 504   // replaceWithUniqued().
 505   auto *RetTy = MDCompositeType::get(
 506       VMContext, Tag, Name, F, Line,
 507       MDScopeRef::get(getNonCompileUnitScope(Scope)), nullptr, SizeInBits,
 508       AlignInBits, 0, DebugNode::FlagFwdDecl, nullptr, RuntimeLang, nullptr,
 509       nullptr, UniqueIdentifier);
 510   if (!UniqueIdentifier.empty())
 511     retainType(RetTy);
 512   trackIfUnresolved(RetTy);
 513   return RetTy;
 514 }
 515
 516 MDCompositeType* DIBuilder::createReplaceableCompositeType(
 517     unsigned Tag, StringRef Name, MDScope * Scope, MDFile* F, unsigned Line,
 518     unsigned RuntimeLang, uint64_t SizeInBits, uint64_t AlignInBits,
 519     unsigned Flags, StringRef UniqueIdentifier) {
 520   auto *RetTy = MDCompositeType::getTemporary(
 521                     VMContext, Tag, Name, F, Line,
 522                     MDScopeRef::get(getNonCompileUnitScope(Scope)), nullptr,
 523                     SizeInBits, AlignInBits, 0, Flags, nullptr, RuntimeLang,
 524                     nullptr, nullptr, UniqueIdentifier).release();
 525   if (!UniqueIdentifier.empty())
 526     retainType(RetTy);
 527   trackIfUnresolved(RetTy);
 528   return RetTy;
 529 }
 530
 531 DIArray DIBuilder::getOrCreateArray(ArrayRef<Metadata *> Elements) {
 532   return MDTuple::get(VMContext, Elements);
 533 }
 534
 535 DITypeArray DIBuilder::getOrCreateTypeArray(ArrayRef<Metadata *> Elements) {
 536   SmallVector<llvm::Metadata *, 16> Elts;
 537   for (unsigned i = 0, e = Elements.size(); i != e; ++i) {
 538     if (Elements[i] && isa<MDNode>(Elements[i]))
 539       Elts.push_back(MDTypeRef::get(cast<MDType>(Elements[i])));
 540     else
 541       Elts.push_back(Elements[i]);
 542   }
 543   return DITypeArray(MDNode::get(VMContext, Elts));
 544 }
 545
 546 MDSubrange *DIBuilder::getOrCreateSubrange(int64_t Lo, int64_t Count) {
 547   return MDSubrange::get(VMContext, Count, Lo);
 548 }
 549
 550 static void checkGlobalVariableScope(MDScope * Context) {
 551 #ifndef NDEBUG
 552   if (auto *CT =
 553           dyn_cast_or_null<MDCompositeType>(getNonCompileUnitScope(Context)))
 554     assert(CT->getIdentifier().empty() &&
 555            "Context of a global variable should not be a type with identifier");
 556 #endif
 557 }
 558
 559 MDGlobalVariable *DIBuilder::createGlobalVariable(
 560     MDScope *Context, StringRef Name, StringRef LinkageName, MDFile *F,
 561     unsigned LineNumber, MDType *Ty, bool isLocalToUnit, Constant *Val,
 562     MDNode *Decl) {
 563   checkGlobalVariableScope(Context);
 564
 565   auto *N = MDGlobalVariable::get(VMContext, cast_or_null<MDScope>(Context),
 566                                   Name, LinkageName, F, LineNumber,
 567                                   MDTypeRef::get(Ty), isLocalToUnit, true, Val,
 568                                   cast_or_null<MDDerivedType>(Decl));
 569   AllGVs.push_back(N);
 570   return N;
 571 }
 572
 573 MDGlobalVariable *DIBuilder::createTempGlobalVariableFwdDecl(
 574     MDScope *Context, StringRef Name, StringRef LinkageName, MDFile *F,
 575     unsigned LineNumber, MDType *Ty, bool isLocalToUnit, Constant *Val,
 576     MDNode *Decl) {
 577   checkGlobalVariableScope(Context);
 578
 579   return MDGlobalVariable::getTemporary(
 580              VMContext, cast_or_null<MDScope>(Context), Name, LinkageName, F,
 581              LineNumber, MDTypeRef::get(Ty), isLocalToUnit, false, Val,
 582              cast_or_null<MDDerivedType>(Decl))
 583       .release();
 584 }
 585
 586 MDLocalVariable *DIBuilder::createLocalVariable(
 587     unsigned Tag, MDScope *Scope, StringRef Name, MDFile *File, unsigned LineNo,
 588     MDType *Ty, bool AlwaysPreserve, unsigned Flags, unsigned ArgNo) {
 589   // FIXME: Why getNonCompileUnitScope()?
 590   // FIXME: Why is "!Context" okay here?
 591   // FIXME: WHy doesn't this check for a subprogram or lexical block (AFAICT
 592   // the only valid scopes)?
 593   MDScope* Context = getNonCompileUnitScope(Scope);
 594
 595   auto *Node = MDLocalVariable::get(
 596       VMContext, Tag, cast_or_null<MDLocalScope>(Context), Name, File, LineNo,
 597       MDTypeRef::get(Ty), ArgNo, Flags);
 598   if (AlwaysPreserve) {
 599     // The optimizer may remove local variable. If there is an interest
 600     // to preserve variable info in such situation then stash it in a
 601     // named mdnode.
 602     MDSubprogram *Fn = getDISubprogram(Scope);
 603     assert(Fn && "Missing subprogram for local variable");
 604     PreservedVariables[Fn].emplace_back(Node);
 605   }
 606   return Node;
 607 }
 608
 609 MDExpression* DIBuilder::createExpression(ArrayRef<uint64_t> Addr) {
 610   return MDExpression::get(VMContext, Addr);
 611 }
 612
 613 MDExpression* DIBuilder::createExpression(ArrayRef<int64_t> Signed) {
 614   // TODO: Remove the callers of this signed version and delete.
 615   SmallVector<uint64_t, 8> Addr(Signed.begin(), Signed.end());
 616   return createExpression(Addr);
 617 }
 618
 619 MDExpression* DIBuilder::createBitPieceExpression(unsigned OffsetInBytes,
 620                                                  unsigned SizeInBytes) {
 621   uint64_t Addr[] = {dwarf::DW_OP_bit_piece, OffsetInBytes, SizeInBytes};
 622   return MDExpression::get(VMContext, Addr);
 623 }
 624
 625 MDSubprogram* DIBuilder::createFunction(DIScopeRef Context, StringRef Name,
 626                                        StringRef LinkageName, MDFile* File,
 627                                        unsigned LineNo, MDSubroutineType* Ty,
 628                                        bool isLocalToUnit, bool isDefinition,
 629                                        unsigned ScopeLine, unsigned Flags,
 630                                        bool isOptimized, Function *Fn,
 631                                        MDNode *TParams, MDNode *Decl) {
 632   // dragonegg does not generate identifier for types, so using an empty map
 633   // to resolve the context should be fine.
 634   DITypeIdentifierMap EmptyMap;
 635   return createFunction(Context.resolve(EmptyMap), Name, LinkageName, File,
 636                         LineNo, Ty, isLocalToUnit, isDefinition, ScopeLine,
 637                         Flags, isOptimized, Fn, TParams, Decl);
 638 }
 639
 640 MDSubprogram* DIBuilder::createFunction(MDScope * Context, StringRef Name,
 641                                        StringRef LinkageName, MDFile* File,
 642                                        unsigned LineNo, MDSubroutineType* Ty,
 643                                        bool isLocalToUnit, bool isDefinition,
 644                                        unsigned ScopeLine, unsigned Flags,
 645                                        bool isOptimized, Function *Fn,
 646                                        MDNode *TParams, MDNode *Decl) {
 647   assert(Ty->getTag() == dwarf::DW_TAG_subroutine_type &&
 648          "function types should be subroutines");
 649   auto *Node = MDSubprogram::get(
 650       VMContext, MDScopeRef::get(getNonCompileUnitScope(Context)), Name,
 651       LinkageName, File, LineNo, Ty,
 652       isLocalToUnit, isDefinition, ScopeLine, nullptr, 0, 0, Flags, isOptimized,
 653       Fn, cast_or_null<MDTuple>(TParams), cast_or_null<MDSubprogram>(Decl),
 654       MDTuple::getTemporary(VMContext, None).release());
 655
 656   if (isDefinition)
 657     AllSubprograms.push_back(Node);
 658   trackIfUnresolved(Node);
 659   return Node;
 660 }
 661
 662 MDSubprogram*
 663 DIBuilder::createTempFunctionFwdDecl(MDScope * Context, StringRef Name,
 664                                      StringRef LinkageName, MDFile* File,
 665                                      unsigned LineNo, MDSubroutineType* Ty,
 666                                      bool isLocalToUnit, bool isDefinition,
 667                                      unsigned ScopeLine, unsigned Flags,
 668                                      bool isOptimized, Function *Fn,
 669                                      MDNode *TParams, MDNode *Decl) {
 670   return MDSubprogram::getTemporary(
 671              VMContext, MDScopeRef::get(getNonCompileUnitScope(Context)), Name,
 672              LinkageName, File, LineNo, Ty,
 673              isLocalToUnit, isDefinition, ScopeLine, nullptr, 0, 0, Flags,
 674              isOptimized, Fn, cast_or_null<MDTuple>(TParams),
 675              cast_or_null<MDSubprogram>(Decl), nullptr).release();
 676 }
 677
 678 MDSubprogram *
 679 DIBuilder::createMethod(MDScope *Context, StringRef Name, StringRef LinkageName,
 680                         MDFile *F, unsigned LineNo, MDSubroutineType *Ty,
 681                         bool isLocalToUnit, bool isDefinition, unsigned VK,
 682                         unsigned VIndex, MDType *VTableHolder, unsigned Flags,
 683                         bool isOptimized, Function *Fn, MDNode *TParam) {
 684   assert(Ty->getTag() == dwarf::DW_TAG_subroutine_type &&
 685          "function types should be subroutines");
 686   assert(getNonCompileUnitScope(Context) &&
 687          "Methods should have both a Context and a context that isn't "
 688          "the compile unit.");
 689   // FIXME: Do we want to use different scope/lines?
 690   auto *SP = MDSubprogram::get(
 691       VMContext, MDScopeRef::get(cast<MDScope>(Context)), Name, LinkageName, F,
 692       LineNo, Ty, isLocalToUnit, isDefinition, LineNo,
 693       MDTypeRef::get(VTableHolder), VK, VIndex, Flags, isOptimized, Fn,
 694       cast_or_null<MDTuple>(TParam), nullptr, nullptr);
 695
 696   if (isDefinition)
 697     AllSubprograms.push_back(SP);
 698   trackIfUnresolved(SP);
 699   return SP;
 700 }
 701
 702 MDNamespace* DIBuilder::createNameSpace(MDScope * Scope, StringRef Name,
 703                                        MDFile* File, unsigned LineNo) {
 704   return MDNamespace::get(VMContext, getNonCompileUnitScope(Scope), File, Name,
 705                           LineNo);
 706 }
 707
 708 MDLexicalBlockFile* DIBuilder::createLexicalBlockFile(MDScope * Scope,
 709                                                      MDFile* File,
 710                                                      unsigned Discriminator) {
 711   return MDLexicalBlockFile::get(VMContext, Scope, File, Discriminator);
 712 }
 713
 714 MDLexicalBlock* DIBuilder::createLexicalBlock(MDScope * Scope, MDFile* File,
 715                                              unsigned Line, unsigned Col) {
 716   // Make these distinct, to avoid merging two lexical blocks on the same
 717   // file/line/column.
 718   return MDLexicalBlock::getDistinct(VMContext, getNonCompileUnitScope(Scope),
 719                                      File, Line, Col);
 720 }
 721
 722 static Value *getDbgIntrinsicValueImpl(LLVMContext &VMContext, Value *V) {
 723   assert(V && "no value passed to dbg intrinsic");
 724   return MetadataAsValue::get(VMContext, ValueAsMetadata::get(V));
 725 }
 726
 727 static Instruction *withDebugLoc(Instruction *I, const MDLocation *DL) {
 728   I->setDebugLoc(const_cast<MDLocation *>(DL));
 729   return I;
 730 }
 731
 732 Instruction *DIBuilder::insertDeclare(Value *Storage, MDLocalVariable* VarInfo,
 733                                       MDExpression* Expr, const MDLocation *DL,
 734                                       Instruction *InsertBefore) {
 735   assert(VarInfo && "empty or invalid MDLocalVariable* passed to dbg.declare");
 736   assert(DL && "Expected debug loc");
 737   assert(DL->getScope()->getSubprogram() ==
 738              VarInfo->getScope()->getSubprogram() &&
 739          "Expected matching subprograms");
 740   if (!DeclareFn)
 741     DeclareFn = Intrinsic::getDeclaration(&M, Intrinsic::dbg_declare);
 742
 743   trackIfUnresolved(VarInfo);
 744   trackIfUnresolved(Expr);
 745   Value *Args[] = {getDbgIntrinsicValueImpl(VMContext, Storage),
 746                    MetadataAsValue::get(VMContext, VarInfo),
 747                    MetadataAsValue::get(VMContext, Expr)};
 748   return withDebugLoc(CallInst::Create(DeclareFn, Args, "", InsertBefore), DL);
 749 }
 750
 751 Instruction *DIBuilder::insertDeclare(Value *Storage, MDLocalVariable* VarInfo,
 752                                       MDExpression* Expr, const MDLocation *DL,
 753                                       BasicBlock *InsertAtEnd) {
 754   assert(VarInfo && "empty or invalid MDLocalVariable* passed to dbg.declare");
 755   assert(DL && "Expected debug loc");
 756   assert(DL->getScope()->getSubprogram() ==
 757              VarInfo->getScope()->getSubprogram() &&
 758          "Expected matching subprograms");
 759   if (!DeclareFn)
 760     DeclareFn = Intrinsic::getDeclaration(&M, Intrinsic::dbg_declare);
 761
 762   trackIfUnresolved(VarInfo);
 763   trackIfUnresolved(Expr);
 764   Value *Args[] = {getDbgIntrinsicValueImpl(VMContext, Storage),
 765                    MetadataAsValue::get(VMContext, VarInfo),
 766                    MetadataAsValue::get(VMContext, Expr)};
 767
 768   // If this block already has a terminator then insert this intrinsic
 769   // before the terminator.
 770   if (TerminatorInst *T = InsertAtEnd->getTerminator())
 771     return withDebugLoc(CallInst::Create(DeclareFn, Args, "", T), DL);
 772   return withDebugLoc(CallInst::Create(DeclareFn, Args, "", InsertAtEnd), DL);
 773 }
 774
 775 Instruction *DIBuilder::insertDbgValueIntrinsic(Value *V, uint64_t Offset,
 776                                                 MDLocalVariable* VarInfo,
 777                                                 MDExpression* Expr,
 778                                                 const MDLocation *DL,
 779                                                 Instruction *InsertBefore) {
 780   assert(V && "no value passed to dbg.value");
 781   assert(VarInfo && "empty or invalid MDLocalVariable* passed to dbg.value");
 782   assert(DL && "Expected debug loc");
 783   assert(DL->getScope()->getSubprogram() ==
 784              VarInfo->getScope()->getSubprogram() &&
 785          "Expected matching subprograms");
 786   if (!ValueFn)
 787     ValueFn = Intrinsic::getDeclaration(&M, Intrinsic::dbg_value);
 788
 789   trackIfUnresolved(VarInfo);
 790   trackIfUnresolved(Expr);
 791   Value *Args[] = {getDbgIntrinsicValueImpl(VMContext, V),
 792                    ConstantInt::get(Type::getInt64Ty(VMContext), Offset),
 793                    MetadataAsValue::get(VMContext, VarInfo),
 794                    MetadataAsValue::get(VMContext, Expr)};
 795   return withDebugLoc(CallInst::Create(ValueFn, Args, "", InsertBefore), DL);
 796 }
 797
 798 Instruction *DIBuilder::insertDbgValueIntrinsic(Value *V, uint64_t Offset,
 799                                                 MDLocalVariable* VarInfo,
 800                                                 MDExpression* Expr,
 801                                                 const MDLocation *DL,
 802                                                 BasicBlock *InsertAtEnd) {
 803   assert(V && "no value passed to dbg.value");
 804   assert(VarInfo && "empty or invalid MDLocalVariable* passed to dbg.value");
 805   assert(DL && "Expected debug loc");
 806   assert(DL->getScope()->getSubprogram() ==
 807              VarInfo->getScope()->getSubprogram() &&
 808          "Expected matching subprograms");
 809   if (!ValueFn)
 810     ValueFn = Intrinsic::getDeclaration(&M, Intrinsic::dbg_value);
 811
 812   trackIfUnresolved(VarInfo);
 813   trackIfUnresolved(Expr);
 814   Value *Args[] = {getDbgIntrinsicValueImpl(VMContext, V),
 815                    ConstantInt::get(Type::getInt64Ty(VMContext), Offset),
 816                    MetadataAsValue::get(VMContext, VarInfo),
 817                    MetadataAsValue::get(VMContext, Expr)};
 818
 819   return withDebugLoc(CallInst::Create(ValueFn, Args, "", InsertAtEnd), DL);
 820 }
 821
 822 void DIBuilder::replaceVTableHolder(MDCompositeType* &T, MDCompositeType* VTableHolder) {
 823   {
 824     TypedTrackingMDRef<MDCompositeType> N(T);
 825     N->replaceVTableHolder(MDTypeRef::get(VTableHolder));
 826     T = N.get();
 827   }
 828
 829   // If this didn't create a self-reference, just return.
 830   if (T != VTableHolder)
 831     return;
 832
 833   // Look for unresolved operands.  T will drop RAUW support, orphaning any
 834   // cycles underneath it.
 835   if (T->isResolved())
 836     for (const MDOperand &O : T->operands())
 837       if (auto *N = dyn_cast_or_null<MDNode>(O))
 838         trackIfUnresolved(N);
 839 }
 840
 841 void DIBuilder::replaceArrays(MDCompositeType* &T, DIArray Elements,
 842                               DIArray TParams) {
 843   {
 844     TypedTrackingMDRef<MDCompositeType> N(T);
 845     if (Elements)
 846       N->replaceElements(Elements);
 847     if (TParams)
 848       N->replaceTemplateParams(MDTemplateParameterArray(TParams));
 849     T = N.get();
 850   }
 851
 852   // If T isn't resolved, there's no problem.
 853   if (!T->isResolved())
 854     return;
 855
 856   // If "T" is resolved, it may be due to a self-reference cycle.  Track the
 857   // arrays explicitly if they're unresolved, or else the cycles will be
 858   // orphaned.
 859   if (Elements)
 860     trackIfUnresolved(Elements.get());
 861   if (TParams)
 862     trackIfUnresolved(TParams.get());
 863 }