clang/lib/CodeGen/CGDebugInfo.h

   1 //===--- CGDebugInfo.h - DebugInfo for LLVM CodeGen -------------*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This is the source-level debug info generator for llvm translation.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #ifndef LLVM_CLANG_LIB_CODEGEN_CGDEBUGINFO_H
  14 #define LLVM_CLANG_LIB_CODEGEN_CGDEBUGINFO_H
  15
  16 #include "CGBuilder.h"
  17 #include "clang/AST/DeclCXX.h"
  18 #include "clang/AST/Expr.h"
  19 #include "clang/AST/ExternalASTSource.h"
  20 #include "clang/AST/PrettyPrinter.h"
  21 #include "clang/AST/Type.h"
  22 #include "clang/AST/TypeOrdering.h"
  23 #include "clang/Basic/CodeGenOptions.h"
  24 #include "clang/Basic/Module.h"
  25 #include "clang/Basic/SourceLocation.h"
  26 #include "llvm/ADT/DenseMap.h"
  27 #include "llvm/ADT/DenseSet.h"
  28 #include "llvm/IR/DIBuilder.h"
  29 #include "llvm/IR/DebugInfo.h"
  30 #include "llvm/IR/ValueHandle.h"
  31 #include "llvm/Support/Allocator.h"
  32 #include <optional>
  33
  34 namespace llvm {
  35 class MDNode;
  36 }
  37
  38 namespace clang {
  39 class ClassTemplateSpecializationDecl;
  40 class GlobalDecl;
  41 class ModuleMap;
  42 class ObjCInterfaceDecl;
  43 class UsingDecl;
  44 class VarDecl;
  45 enum class DynamicInitKind : unsigned;
  46
  47 namespace CodeGen {
  48 class CodeGenModule;
  49 class CodeGenFunction;
  50 class CGBlockInfo;
  51
  52 /// This class gathers all debug information during compilation and is
  53 /// responsible for emitting to llvm globals or pass directly to the
  54 /// backend.
  55 class CGDebugInfo {
  56   friend class ApplyDebugLocation;
  57   friend class SaveAndRestoreLocation;
  58   CodeGenModule &CGM;
  59   const llvm::codegenoptions::DebugInfoKind DebugKind;
  60   bool DebugTypeExtRefs;
  61   llvm::DIBuilder DBuilder;
  62   llvm::DICompileUnit *TheCU = nullptr;
  63   ModuleMap *ClangModuleMap = nullptr;
  64   ASTSourceDescriptor PCHDescriptor;
  65   SourceLocation CurLoc;
  66   llvm::MDNode *CurInlinedAt = nullptr;
  67   llvm::DIType *VTablePtrType = nullptr;
  68   llvm::DIType *ClassTy = nullptr;
  69   llvm::DICompositeType *ObjTy = nullptr;
  70   llvm::DIType *SelTy = nullptr;
  71 #define IMAGE_TYPE(ImgType, Id, SingletonId, Access, Suffix)                   \
  72   llvm::DIType *SingletonId = nullptr;
  73 #include "clang/Basic/OpenCLImageTypes.def"
  74   llvm::DIType *OCLSamplerDITy = nullptr;
  75   llvm::DIType *OCLEventDITy = nullptr;
  76   llvm::DIType *OCLClkEventDITy = nullptr;
  77   llvm::DIType *OCLQueueDITy = nullptr;
  78   llvm::DIType *OCLNDRangeDITy = nullptr;
  79   llvm::DIType *OCLReserveIDDITy = nullptr;
  80 #define EXT_OPAQUE_TYPE(ExtType, Id, Ext) \
  81   llvm::DIType *Id##Ty = nullptr;
  82 #include "clang/Basic/OpenCLExtensionTypes.def"
  83 #define WASM_TYPE(Name, Id, SingletonId) llvm::DIType *SingletonId = nullptr;
  84 #include "clang/Basic/WebAssemblyReferenceTypes.def"
  85
  86   /// Cache of previously constructed Types.
  87   llvm::DenseMap<const void *, llvm::TrackingMDRef> TypeCache;
  88
  89   /// Cache that maps VLA types to size expressions for that type,
  90   /// represented by instantiated Metadata nodes.
  91   llvm::SmallDenseMap<QualType, llvm::Metadata *> SizeExprCache;
  92
  93   /// Callbacks to use when printing names and types.
  94   class PrintingCallbacks final : public clang::PrintingCallbacks {
  95     const CGDebugInfo &Self;
  96
  97   public:
  98     PrintingCallbacks(const CGDebugInfo &Self) : Self(Self) {}
  99     std::string remapPath(StringRef Path) const override {
 100       return Self.remapDIPath(Path);
 101     }
 102   };
 103   PrintingCallbacks PrintCB = {*this};
 104
 105   struct ObjCInterfaceCacheEntry {
 106     const ObjCInterfaceType *Type;
 107     llvm::DIType *Decl;
 108     llvm::DIFile *Unit;
 109     ObjCInterfaceCacheEntry(const ObjCInterfaceType *Type, llvm::DIType *Decl,
 110                             llvm::DIFile *Unit)
 111         : Type(Type), Decl(Decl), Unit(Unit) {}
 112   };
 113
 114   /// Cache of previously constructed interfaces which may change.
 115   llvm::SmallVector<ObjCInterfaceCacheEntry, 32> ObjCInterfaceCache;
 116
 117   /// Cache of forward declarations for methods belonging to the interface.
 118   /// The extra bit on the DISubprogram specifies whether a method is
 119   /// "objc_direct".
 120   llvm::DenseMap<const ObjCInterfaceDecl *,
 121                  std::vector<llvm::PointerIntPair<llvm::DISubprogram *, 1>>>
 122       ObjCMethodCache;
 123
 124   /// Cache of references to clang modules and precompiled headers.
 125   llvm::DenseMap<const Module *, llvm::TrackingMDRef> ModuleCache;
 126
 127   /// List of interfaces we want to keep even if orphaned.
 128   std::vector<void *> RetainedTypes;
 129
 130   /// Cache of forward declared types to RAUW at the end of compilation.
 131   std::vector<std::pair<const TagType *, llvm::TrackingMDRef>> ReplaceMap;
 132
 133   /// Cache of replaceable forward declarations (functions and
 134   /// variables) to RAUW at the end of compilation.
 135   std::vector<std::pair<const DeclaratorDecl *, llvm::TrackingMDRef>>
 136       FwdDeclReplaceMap;
 137
 138   /// Keep track of our current nested lexical block.
 139   std::vector<llvm::TypedTrackingMDRef<llvm::DIScope>> LexicalBlockStack;
 140   llvm::DenseMap<const Decl *, llvm::TrackingMDRef> RegionMap;
 141   /// Keep track of LexicalBlockStack counter at the beginning of a
 142   /// function. This is used to pop unbalanced regions at the end of a
 143   /// function.
 144   std::vector<unsigned> FnBeginRegionCount;
 145
 146   /// This is a storage for names that are constructed on demand. For
 147   /// example, C++ destructors, C++ operators etc..
 148   llvm::BumpPtrAllocator DebugInfoNames;
 149   StringRef CWDName;
 150
 151   llvm::DenseMap<const char *, llvm::TrackingMDRef> DIFileCache;
 152   llvm::DenseMap<const FunctionDecl *, llvm::TrackingMDRef> SPCache;
 153   /// Cache declarations relevant to DW_TAG_imported_declarations (C++
 154   /// using declarations and global alias variables) that aren't covered
 155   /// by other more specific caches.
 156   llvm::DenseMap<const Decl *, llvm::TrackingMDRef> DeclCache;
 157   llvm::DenseMap<const Decl *, llvm::TrackingMDRef> ImportedDeclCache;
 158   llvm::DenseMap<const NamespaceDecl *, llvm::TrackingMDRef> NamespaceCache;
 159   llvm::DenseMap<const NamespaceAliasDecl *, llvm::TrackingMDRef>
 160       NamespaceAliasCache;
 161   llvm::DenseMap<const Decl *, llvm::TypedTrackingMDRef<llvm::DIDerivedType>>
 162       StaticDataMemberCache;
 163
 164   using ParamDecl2StmtTy = llvm::DenseMap<const ParmVarDecl *, const Stmt *>;
 165   using Param2DILocTy =
 166       llvm::DenseMap<const ParmVarDecl *, llvm::DILocalVariable *>;
 167
 168   /// The key is coroutine real parameters, value is coroutine move parameters.
 169   ParamDecl2StmtTy CoroutineParameterMappings;
 170   /// The key is coroutine real parameters, value is DIVariable in LLVM IR.
 171   Param2DILocTy ParamDbgMappings;
 172
 173   /// Helper functions for getOrCreateType.
 174   /// @{
 175   /// Currently the checksum of an interface includes the number of
 176   /// ivars and property accessors.
 177   llvm::DIType *CreateType(const BuiltinType *Ty);
 178   llvm::DIType *CreateType(const ComplexType *Ty);
 179   llvm::DIType *CreateType(const BitIntType *Ty);
 180   llvm::DIType *CreateQualifiedType(QualType Ty, llvm::DIFile *Fg);
 181   llvm::DIType *CreateQualifiedType(const FunctionProtoType *Ty,
 182                                     llvm::DIFile *Fg);
 183   llvm::DIType *CreateType(const TypedefType *Ty, llvm::DIFile *Fg);
 184   llvm::DIType *CreateType(const TemplateSpecializationType *Ty,
 185                            llvm::DIFile *Fg);
 186   llvm::DIType *CreateType(const ObjCObjectPointerType *Ty, llvm::DIFile *F);
 187   llvm::DIType *CreateType(const PointerType *Ty, llvm::DIFile *F);
 188   llvm::DIType *CreateType(const BlockPointerType *Ty, llvm::DIFile *F);
 189   llvm::DIType *CreateType(const FunctionType *Ty, llvm::DIFile *F);
 190   /// Get structure or union type.
 191   llvm::DIType *CreateType(const RecordType *Tyg);
 192
 193   /// Create definition for the specified 'Ty'.
 194   ///
 195   /// \returns A pair of 'llvm::DIType's. The first is the definition
 196   /// of the 'Ty'. The second is the type specified by the preferred_name
 197   /// attribute on 'Ty', which can be a nullptr if no such attribute
 198   /// exists.
 199   std::pair<llvm::DIType *, llvm::DIType *>
 200   CreateTypeDefinition(const RecordType *Ty);
 201   llvm::DICompositeType *CreateLimitedType(const RecordType *Ty);
 202   void CollectContainingType(const CXXRecordDecl *RD,
 203                              llvm::DICompositeType *CT);
 204   /// Get Objective-C interface type.
 205   llvm::DIType *CreateType(const ObjCInterfaceType *Ty, llvm::DIFile *F);
 206   llvm::DIType *CreateTypeDefinition(const ObjCInterfaceType *Ty,
 207                                      llvm::DIFile *F);
 208   /// Get Objective-C object type.
 209   llvm::DIType *CreateType(const ObjCObjectType *Ty, llvm::DIFile *F);
 210   llvm::DIType *CreateType(const ObjCTypeParamType *Ty, llvm::DIFile *Unit);
 211
 212   llvm::DIType *CreateType(const VectorType *Ty, llvm::DIFile *F);
 213   llvm::DIType *CreateType(const ConstantMatrixType *Ty, llvm::DIFile *F);
 214   llvm::DIType *CreateType(const ArrayType *Ty, llvm::DIFile *F);
 215   llvm::DIType *CreateType(const LValueReferenceType *Ty, llvm::DIFile *F);
 216   llvm::DIType *CreateType(const RValueReferenceType *Ty, llvm::DIFile *Unit);
 217   llvm::DIType *CreateType(const MemberPointerType *Ty, llvm::DIFile *F);
 218   llvm::DIType *CreateType(const AtomicType *Ty, llvm::DIFile *F);
 219   llvm::DIType *CreateType(const PipeType *Ty, llvm::DIFile *F);
 220   /// Get enumeration type.
 221   llvm::DIType *CreateEnumType(const EnumType *Ty);
 222   llvm::DIType *CreateTypeDefinition(const EnumType *Ty);
 223   /// Look up the completed type for a self pointer in the TypeCache and
 224   /// create a copy of it with the ObjectPointer and Artificial flags
 225   /// set. If the type is not cached, a new one is created. This should
 226   /// never happen though, since creating a type for the implicit self
 227   /// argument implies that we already parsed the interface definition
 228   /// and the ivar declarations in the implementation.
 229   llvm::DIType *CreateSelfType(const QualType &QualTy, llvm::DIType *Ty);
 230   /// @}
 231
 232   /// Get the type from the cache or return null type if it doesn't
 233   /// exist.
 234   llvm::DIType *getTypeOrNull(const QualType);
 235   /// Return the debug type for a C++ method.
 236   /// \arg CXXMethodDecl is of FunctionType. This function type is
 237   /// not updated to include implicit \c this pointer. Use this routine
 238   /// to get a method type which includes \c this pointer.
 239   llvm::DISubroutineType *getOrCreateMethodType(const CXXMethodDecl *Method,
 240                                                 llvm::DIFile *F);
 241   llvm::DISubroutineType *
 242   getOrCreateInstanceMethodType(QualType ThisPtr, const FunctionProtoType *Func,
 243                                 llvm::DIFile *Unit);
 244   llvm::DISubroutineType *
 245   getOrCreateFunctionType(const Decl *D, QualType FnType, llvm::DIFile *F);
 246   /// \return debug info descriptor for vtable.
 247   llvm::DIType *getOrCreateVTablePtrType(llvm::DIFile *F);
 248
 249   /// \return namespace descriptor for the given namespace decl.
 250   llvm::DINamespace *getOrCreateNamespace(const NamespaceDecl *N);
 251   llvm::DIType *CreatePointerLikeType(llvm::dwarf::Tag Tag, const Type *Ty,
 252                                       QualType PointeeTy, llvm::DIFile *F);
 253   llvm::DIType *getOrCreateStructPtrType(StringRef Name, llvm::DIType *&Cache);
 254
 255   /// A helper function to create a subprogram for a single member
 256   /// function GlobalDecl.
 257   llvm::DISubprogram *CreateCXXMemberFunction(const CXXMethodDecl *Method,
 258                                               llvm::DIFile *F,
 259                                               llvm::DIType *RecordTy);
 260
 261   /// A helper function to collect debug info for C++ member
 262   /// functions. This is used while creating debug info entry for a
 263   /// Record.
 264   void CollectCXXMemberFunctions(const CXXRecordDecl *Decl, llvm::DIFile *F,
 265                                  SmallVectorImpl<llvm::Metadata *> &E,
 266                                  llvm::DIType *T);
 267
 268   /// A helper function to collect debug info for C++ base
 269   /// classes. This is used while creating debug info entry for a
 270   /// Record.
 271   void CollectCXXBases(const CXXRecordDecl *Decl, llvm::DIFile *F,
 272                        SmallVectorImpl<llvm::Metadata *> &EltTys,
 273                        llvm::DIType *RecordTy);
 274
 275   /// Helper function for CollectCXXBases.
 276   /// Adds debug info entries for types in Bases that are not in SeenTypes.
 277   void CollectCXXBasesAux(
 278       const CXXRecordDecl *RD, llvm::DIFile *Unit,
 279       SmallVectorImpl<llvm::Metadata *> &EltTys, llvm::DIType *RecordTy,
 280       const CXXRecordDecl::base_class_const_range &Bases,
 281       llvm::DenseSet<CanonicalDeclPtr<const CXXRecordDecl>> &SeenTypes,
 282       llvm::DINode::DIFlags StartingFlags);
 283
 284   /// Helper function that returns the llvm::DIType that the
 285   /// PreferredNameAttr attribute on \ref RD refers to. If no such
 286   /// attribute exists, returns nullptr.
 287   llvm::DIType *GetPreferredNameType(const CXXRecordDecl *RD,
 288                                      llvm::DIFile *Unit);
 289
 290   struct TemplateArgs {
 291     const TemplateParameterList *TList;
 292     llvm::ArrayRef<TemplateArgument> Args;
 293   };
 294   /// A helper function to collect template parameters.
 295   llvm::DINodeArray CollectTemplateParams(std::optional<TemplateArgs> Args,
 296                                           llvm::DIFile *Unit);
 297   /// A helper function to collect debug info for function template
 298   /// parameters.
 299   llvm::DINodeArray CollectFunctionTemplateParams(const FunctionDecl *FD,
 300                                                   llvm::DIFile *Unit);
 301
 302   /// A helper function to collect debug info for function template
 303   /// parameters.
 304   llvm::DINodeArray CollectVarTemplateParams(const VarDecl *VD,
 305                                              llvm::DIFile *Unit);
 306
 307   std::optional<TemplateArgs> GetTemplateArgs(const VarDecl *) const;
 308   std::optional<TemplateArgs> GetTemplateArgs(const RecordDecl *) const;
 309   std::optional<TemplateArgs> GetTemplateArgs(const FunctionDecl *) const;
 310
 311   /// A helper function to collect debug info for template
 312   /// parameters.
 313   llvm::DINodeArray CollectCXXTemplateParams(const RecordDecl *TS,
 314                                              llvm::DIFile *F);
 315
 316   /// A helper function to collect debug info for btf_decl_tag annotations.
 317   llvm::DINodeArray CollectBTFDeclTagAnnotations(const Decl *D);
 318
 319   llvm::DIType *createFieldType(StringRef name, QualType type,
 320                                 SourceLocation loc, AccessSpecifier AS,
 321                                 uint64_t offsetInBits, uint32_t AlignInBits,
 322                                 llvm::DIFile *tunit, llvm::DIScope *scope,
 323                                 const RecordDecl *RD = nullptr,
 324                                 llvm::DINodeArray Annotations = nullptr);
 325
 326   llvm::DIType *createFieldType(StringRef name, QualType type,
 327                                 SourceLocation loc, AccessSpecifier AS,
 328                                 uint64_t offsetInBits, llvm::DIFile *tunit,
 329                                 llvm::DIScope *scope,
 330                                 const RecordDecl *RD = nullptr) {
 331     return createFieldType(name, type, loc, AS, offsetInBits, 0, tunit, scope,
 332                            RD);
 333   }
 334
 335   /// Create new bit field member.
 336   llvm::DIDerivedType *createBitFieldType(const FieldDecl *BitFieldDecl,
 337                                           llvm::DIScope *RecordTy,
 338                                           const RecordDecl *RD);
 339
 340   /// Create an anonnymous zero-size separator for bit-field-decl if needed on
 341   /// the target.
 342   llvm::DIDerivedType *createBitFieldSeparatorIfNeeded(
 343       const FieldDecl *BitFieldDecl, const llvm::DIDerivedType *BitFieldDI,
 344       llvm::ArrayRef<llvm::Metadata *> PreviousFieldsDI, const RecordDecl *RD);
 345
 346   /// Helpers for collecting fields of a record.
 347   /// @{
 348   void CollectRecordLambdaFields(const CXXRecordDecl *CXXDecl,
 349                                  SmallVectorImpl<llvm::Metadata *> &E,
 350                                  llvm::DIType *RecordTy);
 351   llvm::DIDerivedType *CreateRecordStaticField(const VarDecl *Var,
 352                                                llvm::DIType *RecordTy,
 353                                                const RecordDecl *RD);
 354   void CollectRecordNormalField(const FieldDecl *Field, uint64_t OffsetInBits,
 355                                 llvm::DIFile *F,
 356                                 SmallVectorImpl<llvm::Metadata *> &E,
 357                                 llvm::DIType *RecordTy, const RecordDecl *RD);
 358   void CollectRecordNestedType(const TypeDecl *RD,
 359                                SmallVectorImpl<llvm::Metadata *> &E);
 360   void CollectRecordFields(const RecordDecl *Decl, llvm::DIFile *F,
 361                            SmallVectorImpl<llvm::Metadata *> &E,
 362                            llvm::DICompositeType *RecordTy);
 363
 364   /// If the C++ class has vtable info then insert appropriate debug
 365   /// info entry in EltTys vector.
 366   void CollectVTableInfo(const CXXRecordDecl *Decl, llvm::DIFile *F,
 367                          SmallVectorImpl<llvm::Metadata *> &EltTys);
 368   /// @}
 369
 370   /// Create a new lexical block node and push it on the stack.
 371   void CreateLexicalBlock(SourceLocation Loc);
 372
 373   /// If target-specific LLVM \p AddressSpace directly maps to target-specific
 374   /// DWARF address space, appends extended dereferencing mechanism to complex
 375   /// expression \p Expr. Otherwise, does nothing.
 376   ///
 377   /// Extended dereferencing mechanism is has the following format:
 378   ///     DW_OP_constu <DWARF Address Space> DW_OP_swap DW_OP_xderef
 379   void AppendAddressSpaceXDeref(unsigned AddressSpace,
 380                                 SmallVectorImpl<uint64_t> &Expr) const;
 381
 382   /// A helper function to collect debug info for the default elements of a
 383   /// block.
 384   ///
 385   /// \returns The next available field offset after the default elements.
 386   uint64_t collectDefaultElementTypesForBlockPointer(
 387       const BlockPointerType *Ty, llvm::DIFile *Unit,
 388       llvm::DIDerivedType *DescTy, unsigned LineNo,
 389       SmallVectorImpl<llvm::Metadata *> &EltTys);
 390
 391   /// A helper function to collect debug info for the default fields of a
 392   /// block.
 393   void collectDefaultFieldsForBlockLiteralDeclare(
 394       const CGBlockInfo &Block, const ASTContext &Context, SourceLocation Loc,
 395       const llvm::StructLayout &BlockLayout, llvm::DIFile *Unit,
 396       SmallVectorImpl<llvm::Metadata *> &Fields);
 397
 398 public:
 399   CGDebugInfo(CodeGenModule &CGM);
 400   ~CGDebugInfo();
 401
 402   void finalize();
 403
 404   /// Remap a given path with the current debug prefix map
 405   std::string remapDIPath(StringRef) const;
 406
 407   /// Register VLA size expression debug node with the qualified type.
 408   void registerVLASizeExpression(QualType Ty, llvm::Metadata *SizeExpr) {
 409     SizeExprCache[Ty] = SizeExpr;
 410   }
 411
 412   /// Module debugging: Support for building PCMs.
 413   /// @{
 414   /// Set the main CU's DwoId field to \p Signature.
 415   void setDwoId(uint64_t Signature);
 416
 417   /// When generating debug information for a clang module or
 418   /// precompiled header, this module map will be used to determine
 419   /// the module of origin of each Decl.
 420   void setModuleMap(ModuleMap &MMap) { ClangModuleMap = &MMap; }
 421
 422   /// When generating debug information for a clang module or
 423   /// precompiled header, this module map will be used to determine
 424   /// the module of origin of each Decl.
 425   void setPCHDescriptor(ASTSourceDescriptor PCH) { PCHDescriptor = PCH; }
 426   /// @}
 427
 428   /// Update the current source location. If \arg loc is invalid it is
 429   /// ignored.
 430   void setLocation(SourceLocation Loc);
 431
 432   /// Return the current source location. This does not necessarily correspond
 433   /// to the IRBuilder's current DebugLoc.
 434   SourceLocation getLocation() const { return CurLoc; }
 435
 436   /// Update the current inline scope. All subsequent calls to \p EmitLocation
 437   /// will create a location with this inlinedAt field.
 438   void setInlinedAt(llvm::MDNode *InlinedAt) { CurInlinedAt = InlinedAt; }
 439
 440   /// \return the current inline scope.
 441   llvm::MDNode *getInlinedAt() const { return CurInlinedAt; }
 442
 443   // Converts a SourceLocation to a DebugLoc
 444   llvm::DebugLoc SourceLocToDebugLoc(SourceLocation Loc);
 445
 446   /// Emit metadata to indicate a change in line/column information in
 447   /// the source file. If the location is invalid, the previous
 448   /// location will be reused.
 449   void EmitLocation(CGBuilderTy &Builder, SourceLocation Loc);
 450
 451   QualType getFunctionType(const FunctionDecl *FD, QualType RetTy,
 452                            const SmallVectorImpl<const VarDecl *> &Args);
 453
 454   /// Emit a call to llvm.dbg.function.start to indicate
 455   /// start of a new function.
 456   /// \param Loc       The location of the function header.
 457   /// \param ScopeLoc  The location of the function body.
 458   void emitFunctionStart(GlobalDecl GD, SourceLocation Loc,
 459                          SourceLocation ScopeLoc, QualType FnType,
 460                          llvm::Function *Fn, bool CurFnIsThunk);
 461
 462   /// Start a new scope for an inlined function.
 463   void EmitInlineFunctionStart(CGBuilderTy &Builder, GlobalDecl GD);
 464   /// End an inlined function scope.
 465   void EmitInlineFunctionEnd(CGBuilderTy &Builder);
 466
 467   /// Emit debug info for a function declaration.
 468   /// \p Fn is set only when a declaration for a debug call site gets created.
 469   void EmitFunctionDecl(GlobalDecl GD, SourceLocation Loc,
 470                         QualType FnType, llvm::Function *Fn = nullptr);
 471
 472   /// Emit debug info for an extern function being called.
 473   /// This is needed for call site debug info.
 474   void EmitFuncDeclForCallSite(llvm::CallBase *CallOrInvoke,
 475                                QualType CalleeType,
 476                                const FunctionDecl *CalleeDecl);
 477
 478   /// Constructs the debug code for exiting a function.
 479   void EmitFunctionEnd(CGBuilderTy &Builder, llvm::Function *Fn);
 480
 481   /// Emit metadata to indicate the beginning of a new lexical block
 482   /// and push the block onto the stack.
 483   void EmitLexicalBlockStart(CGBuilderTy &Builder, SourceLocation Loc);
 484
 485   /// Emit metadata to indicate the end of a new lexical block and pop
 486   /// the current block.
 487   void EmitLexicalBlockEnd(CGBuilderTy &Builder, SourceLocation Loc);
 488
 489   /// Emit call to \c llvm.dbg.declare for an automatic variable
 490   /// declaration.
 491   /// Returns a pointer to the DILocalVariable associated with the
 492   /// llvm.dbg.declare, or nullptr otherwise.
 493   llvm::DILocalVariable *
 494   EmitDeclareOfAutoVariable(const VarDecl *Decl, llvm::Value *AI,
 495                             CGBuilderTy &Builder,
 496                             const bool UsePointerValue = false);
 497
 498   /// Emit call to \c llvm.dbg.label for an label.
 499   void EmitLabel(const LabelDecl *D, CGBuilderTy &Builder);
 500
 501   /// Emit call to \c llvm.dbg.declare for an imported variable
 502   /// declaration in a block.
 503   void EmitDeclareOfBlockDeclRefVariable(
 504       const VarDecl *variable, llvm::Value *storage, CGBuilderTy &Builder,
 505       const CGBlockInfo &blockInfo, llvm::Instruction *InsertPoint = nullptr);
 506
 507   /// Emit call to \c llvm.dbg.declare for an argument variable
 508   /// declaration.
 509   llvm::DILocalVariable *
 510   EmitDeclareOfArgVariable(const VarDecl *Decl, llvm::Value *AI, unsigned ArgNo,
 511                            CGBuilderTy &Builder, bool UsePointerValue = false);
 512
 513   /// Emit call to \c llvm.dbg.declare for the block-literal argument
 514   /// to a block invocation function.
 515   void EmitDeclareOfBlockLiteralArgVariable(const CGBlockInfo &block,
 516                                             StringRef Name, unsigned ArgNo,
 517                                             llvm::AllocaInst *LocalAddr,
 518                                             CGBuilderTy &Builder);
 519
 520   /// Emit information about a global variable.
 521   void EmitGlobalVariable(llvm::GlobalVariable *GV, const VarDecl *Decl);
 522
 523   /// Emit a constant global variable's debug info.
 524   void EmitGlobalVariable(const ValueDecl *VD, const APValue &Init);
 525
 526   /// Emit information about an external variable.
 527   void EmitExternalVariable(llvm::GlobalVariable *GV, const VarDecl *Decl);
 528
 529   /// Emit information about global variable alias.
 530   void EmitGlobalAlias(const llvm::GlobalValue *GV, const GlobalDecl Decl);
 531
 532   /// Emit C++ using directive.
 533   void EmitUsingDirective(const UsingDirectiveDecl &UD);
 534
 535   /// Emit the type explicitly casted to.
 536   void EmitExplicitCastType(QualType Ty);
 537
 538   /// Emit the type even if it might not be used.
 539   void EmitAndRetainType(QualType Ty);
 540
 541   /// Emit a shadow decl brought in by a using or using-enum
 542   void EmitUsingShadowDecl(const UsingShadowDecl &USD);
 543
 544   /// Emit C++ using declaration.
 545   void EmitUsingDecl(const UsingDecl &UD);
 546
 547   /// Emit C++ using-enum declaration.
 548   void EmitUsingEnumDecl(const UsingEnumDecl &UD);
 549
 550   /// Emit an @import declaration.
 551   void EmitImportDecl(const ImportDecl &ID);
 552
 553   /// DebugInfo isn't attached to string literals by default. While certain
 554   /// aspects of debuginfo aren't useful for string literals (like a name), it's
 555   /// nice to be able to symbolize the line and column information. This is
 556   /// especially useful for sanitizers, as it allows symbolization of
 557   /// heap-buffer-overflows on constant strings.
 558   void AddStringLiteralDebugInfo(llvm::GlobalVariable *GV,
 559                                  const StringLiteral *S);
 560
 561   /// Emit C++ namespace alias.
 562   llvm::DIImportedEntity *EmitNamespaceAlias(const NamespaceAliasDecl &NA);
 563
 564   /// Emit record type's standalone debug info.
 565   llvm::DIType *getOrCreateRecordType(QualType Ty, SourceLocation L);
 566
 567   /// Emit an Objective-C interface type standalone debug info.
 568   llvm::DIType *getOrCreateInterfaceType(QualType Ty, SourceLocation Loc);
 569
 570   /// Emit standalone debug info for a type.
 571   llvm::DIType *getOrCreateStandaloneType(QualType Ty, SourceLocation Loc);
 572
 573   /// Add heapallocsite metadata for MSAllocator calls.
 574   void addHeapAllocSiteMetadata(llvm::CallBase *CallSite, QualType AllocatedTy,
 575                                 SourceLocation Loc);
 576
 577   void completeType(const EnumDecl *ED);
 578   void completeType(const RecordDecl *RD);
 579   void completeRequiredType(const RecordDecl *RD);
 580   void completeClassData(const RecordDecl *RD);
 581   void completeClass(const RecordDecl *RD);
 582
 583   void completeTemplateDefinition(const ClassTemplateSpecializationDecl &SD);
 584   void completeUnusedClass(const CXXRecordDecl &D);
 585
 586   /// Create debug info for a macro defined by a #define directive or a macro
 587   /// undefined by a #undef directive.
 588   llvm::DIMacro *CreateMacro(llvm::DIMacroFile *Parent, unsigned MType,
 589                              SourceLocation LineLoc, StringRef Name,
 590                              StringRef Value);
 591
 592   /// Create debug info for a file referenced by an #include directive.
 593   llvm::DIMacroFile *CreateTempMacroFile(llvm::DIMacroFile *Parent,
 594                                          SourceLocation LineLoc,
 595                                          SourceLocation FileLoc);
 596
 597   Param2DILocTy &getParamDbgMappings() { return ParamDbgMappings; }
 598   ParamDecl2StmtTy &getCoroutineParameterMappings() {
 599     return CoroutineParameterMappings;
 600   }
 601
 602 private:
 603   /// Emit call to llvm.dbg.declare for a variable declaration.
 604   /// Returns a pointer to the DILocalVariable associated with the
 605   /// llvm.dbg.declare, or nullptr otherwise.
 606   llvm::DILocalVariable *EmitDeclare(const VarDecl *decl, llvm::Value *AI,
 607                                      std::optional<unsigned> ArgNo,
 608                                      CGBuilderTy &Builder,
 609                                      const bool UsePointerValue = false);
 610
 611   /// Emit call to llvm.dbg.declare for a binding declaration.
 612   /// Returns a pointer to the DILocalVariable associated with the
 613   /// llvm.dbg.declare, or nullptr otherwise.
 614   llvm::DILocalVariable *EmitDeclare(const BindingDecl *decl, llvm::Value *AI,
 615                                      std::optional<unsigned> ArgNo,
 616                                      CGBuilderTy &Builder,
 617                                      const bool UsePointerValue = false);
 618
 619   struct BlockByRefType {
 620     /// The wrapper struct used inside the __block_literal struct.
 621     llvm::DIType *BlockByRefWrapper;
 622     /// The type as it appears in the source code.
 623     llvm::DIType *WrappedType;
 624   };
 625
 626   std::string GetName(const Decl*, bool Qualified = false) const;
 627
 628   /// Build up structure info for the byref.  See \a BuildByRefType.
 629   BlockByRefType EmitTypeForVarWithBlocksAttr(const VarDecl *VD,
 630                                               uint64_t *OffSet);
 631
 632   /// Get context info for the DeclContext of \p Decl.
 633   llvm::DIScope *getDeclContextDescriptor(const Decl *D);
 634   /// Get context info for a given DeclContext \p Decl.
 635   llvm::DIScope *getContextDescriptor(const Decl *Context,
 636                                       llvm::DIScope *Default);
 637
 638   llvm::DIScope *getCurrentContextDescriptor(const Decl *Decl);
 639
 640   /// Create a forward decl for a RecordType in a given context.
 641   llvm::DICompositeType *getOrCreateRecordFwdDecl(const RecordType *,
 642                                                   llvm::DIScope *);
 643
 644   /// Return current directory name.
 645   StringRef getCurrentDirname();
 646
 647   /// Create new compile unit.
 648   void CreateCompileUnit();
 649
 650   /// Compute the file checksum debug info for input file ID.
 651   std::optional<llvm::DIFile::ChecksumKind>
 652   computeChecksum(FileID FID, SmallString<64> &Checksum) const;
 653
 654   /// Get the source of the given file ID.
 655   std::optional<StringRef> getSource(const SourceManager &SM, FileID FID);
 656
 657   /// Convenience function to get the file debug info descriptor for the input
 658   /// location.
 659   llvm::DIFile *getOrCreateFile(SourceLocation Loc);
 660
 661   /// Create a file debug info descriptor for a source file.
 662   llvm::DIFile *
 663   createFile(StringRef FileName,
 664              std::optional<llvm::DIFile::ChecksumInfo<StringRef>> CSInfo,
 665              std::optional<StringRef> Source);
 666
 667   /// Get the type from the cache or create a new type if necessary.
 668   llvm::DIType *getOrCreateType(QualType Ty, llvm::DIFile *Fg);
 669
 670   /// Get a reference to a clang module.  If \p CreateSkeletonCU is true,
 671   /// this also creates a split dwarf skeleton compile unit.
 672   llvm::DIModule *getOrCreateModuleRef(ASTSourceDescriptor Mod,
 673                                        bool CreateSkeletonCU);
 674
 675   /// DebugTypeExtRefs: If \p D originated in a clang module, return it.
 676   llvm::DIModule *getParentModuleOrNull(const Decl *D);
 677
 678   /// Get the type from the cache or create a new partial type if
 679   /// necessary.
 680   llvm::DICompositeType *getOrCreateLimitedType(const RecordType *Ty);
 681
 682   /// Create type metadata for a source language type.
 683   llvm::DIType *CreateTypeNode(QualType Ty, llvm::DIFile *Fg);
 684
 685   /// Create new member and increase Offset by FType's size.
 686   llvm::DIType *CreateMemberType(llvm::DIFile *Unit, QualType FType,
 687                                  StringRef Name, uint64_t *Offset);
 688
 689   /// Retrieve the DIDescriptor, if any, for the canonical form of this
 690   /// declaration.
 691   llvm::DINode *getDeclarationOrDefinition(const Decl *D);
 692
 693   /// \return debug info descriptor to describe method
 694   /// declaration for the given method definition.
 695   llvm::DISubprogram *getFunctionDeclaration(const Decl *D);
 696
 697   /// \return          debug info descriptor to the describe method declaration
 698   ///                  for the given method definition.
 699   /// \param FnType    For Objective-C methods, their type.
 700   /// \param LineNo    The declaration's line number.
 701   /// \param Flags     The DIFlags for the method declaration.
 702   /// \param SPFlags   The subprogram-spcific flags for the method declaration.
 703   llvm::DISubprogram *
 704   getObjCMethodDeclaration(const Decl *D, llvm::DISubroutineType *FnType,
 705                            unsigned LineNo, llvm::DINode::DIFlags Flags,
 706                            llvm::DISubprogram::DISPFlags SPFlags);
 707
 708   /// \return debug info descriptor to describe in-class static data
 709   /// member declaration for the given out-of-class definition.  If D
 710   /// is an out-of-class definition of a static data member of a
 711   /// class, find its corresponding in-class declaration.
 712   llvm::DIDerivedType *
 713   getOrCreateStaticDataMemberDeclarationOrNull(const VarDecl *D);
 714
 715   /// Helper that either creates a forward declaration or a stub.
 716   llvm::DISubprogram *getFunctionFwdDeclOrStub(GlobalDecl GD, bool Stub);
 717
 718   /// Create a subprogram describing the forward declaration
 719   /// represented in the given FunctionDecl wrapped in a GlobalDecl.
 720   llvm::DISubprogram *getFunctionForwardDeclaration(GlobalDecl GD);
 721
 722   /// Create a DISubprogram describing the function
 723   /// represented in the given FunctionDecl wrapped in a GlobalDecl.
 724   llvm::DISubprogram *getFunctionStub(GlobalDecl GD);
 725
 726   /// Create a global variable describing the forward declaration
 727   /// represented in the given VarDecl.
 728   llvm::DIGlobalVariable *
 729   getGlobalVariableForwardDeclaration(const VarDecl *VD);
 730
 731   /// Return a global variable that represents one of the collection of global
 732   /// variables created for an anonmyous union.
 733   ///
 734   /// Recursively collect all of the member fields of a global
 735   /// anonymous decl and create static variables for them. The first
 736   /// time this is called it needs to be on a union and then from
 737   /// there we can have additional unnamed fields.
 738   llvm::DIGlobalVariableExpression *
 739   CollectAnonRecordDecls(const RecordDecl *RD, llvm::DIFile *Unit,
 740                          unsigned LineNo, StringRef LinkageName,
 741                          llvm::GlobalVariable *Var, llvm::DIScope *DContext);
 742
 743
 744   /// Return flags which enable debug info emission for call sites, provided
 745   /// that it is supported and enabled.
 746   llvm::DINode::DIFlags getCallSiteRelatedAttrs() const;
 747
 748   /// Get the printing policy for producing names for debug info.
 749   PrintingPolicy getPrintingPolicy() const;
 750
 751   /// Get function name for the given FunctionDecl. If the name is
 752   /// constructed on demand (e.g., C++ destructor) then the name is
 753   /// stored on the side.
 754   StringRef getFunctionName(const FunctionDecl *FD);
 755
 756   /// Returns the unmangled name of an Objective-C method.
 757   /// This is the display name for the debugging info.
 758   StringRef getObjCMethodName(const ObjCMethodDecl *FD);
 759
 760   /// Return selector name. This is used for debugging
 761   /// info.
 762   StringRef getSelectorName(Selector S);
 763
 764   /// Get class name including template argument list.
 765   StringRef getClassName(const RecordDecl *RD);
 766
 767   /// Get the vtable name for the given class.
 768   StringRef getVTableName(const CXXRecordDecl *Decl);
 769
 770   /// Get the name to use in the debug info for a dynamic initializer or atexit
 771   /// stub function.
 772   StringRef getDynamicInitializerName(const VarDecl *VD,
 773                                       DynamicInitKind StubKind,
 774                                       llvm::Function *InitFn);
 775
 776   /// Get line number for the location. If location is invalid
 777   /// then use current location.
 778   unsigned getLineNumber(SourceLocation Loc);
 779
 780   /// Get column number for the location. If location is
 781   /// invalid then use current location.
 782   /// \param Force  Assume DebugColumnInfo option is true.
 783   unsigned getColumnNumber(SourceLocation Loc, bool Force = false);
 784
 785   /// Collect various properties of a FunctionDecl.
 786   /// \param GD  A GlobalDecl whose getDecl() must return a FunctionDecl.
 787   void collectFunctionDeclProps(GlobalDecl GD, llvm::DIFile *Unit,
 788                                 StringRef &Name, StringRef &LinkageName,
 789                                 llvm::DIScope *&FDContext,
 790                                 llvm::DINodeArray &TParamsArray,
 791                                 llvm::DINode::DIFlags &Flags);
 792
 793   /// Collect various properties of a VarDecl.
 794   void collectVarDeclProps(const VarDecl *VD, llvm::DIFile *&Unit,
 795                            unsigned &LineNo, QualType &T, StringRef &Name,
 796                            StringRef &LinkageName,
 797                            llvm::MDTuple *&TemplateParameters,
 798                            llvm::DIScope *&VDContext);
 799
 800   /// Allocate a copy of \p A using the DebugInfoNames allocator
 801   /// and return a reference to it. If multiple arguments are given the strings
 802   /// are concatenated.
 803   StringRef internString(StringRef A, StringRef B = StringRef()) {
 804     char *Data = DebugInfoNames.Allocate<char>(A.size() + B.size());
 805     if (!A.empty())
 806       std::memcpy(Data, A.data(), A.size());
 807     if (!B.empty())
 808       std::memcpy(Data + A.size(), B.data(), B.size());
 809     return StringRef(Data, A.size() + B.size());
 810   }
 811 };
 812
 813 /// A scoped helper to set the current debug location to the specified
 814 /// location or preferred location of the specified Expr.
 815 class ApplyDebugLocation {
 816 private:
 817   void init(SourceLocation TemporaryLocation, bool DefaultToEmpty = false);
 818   ApplyDebugLocation(CodeGenFunction &CGF, bool DefaultToEmpty,
 819                      SourceLocation TemporaryLocation);
 820
 821   llvm::DebugLoc OriginalLocation;
 822   CodeGenFunction *CGF;
 823
 824 public:
 825   /// Set the location to the (valid) TemporaryLocation.
 826   ApplyDebugLocation(CodeGenFunction &CGF, SourceLocation TemporaryLocation);
 827   ApplyDebugLocation(CodeGenFunction &CGF, const Expr *E);
 828   ApplyDebugLocation(CodeGenFunction &CGF, llvm::DebugLoc Loc);
 829   ApplyDebugLocation(ApplyDebugLocation &&Other) : CGF(Other.CGF) {
 830     Other.CGF = nullptr;
 831   }
 832
 833   // Define copy assignment operator.
 834   ApplyDebugLocation &operator=(ApplyDebugLocation &&Other) {
 835     CGF = Other.CGF;
 836     Other.CGF = nullptr;
 837     return *this;
 838   }
 839
 840   ~ApplyDebugLocation();
 841
 842   /// Apply TemporaryLocation if it is valid. Otherwise switch
 843   /// to an artificial debug location that has a valid scope, but no
 844   /// line information.
 845   ///
 846   /// Artificial locations are useful when emitting compiler-generated
 847   /// helper functions that have no source location associated with
 848   /// them. The DWARF specification allows the compiler to use the
 849   /// special line number 0 to indicate code that can not be
 850   /// attributed to any source location. Note that passing an empty
 851   /// SourceLocation to CGDebugInfo::setLocation() will result in the
 852   /// last valid location being reused.
 853   static ApplyDebugLocation CreateArtificial(CodeGenFunction &CGF) {
 854     return ApplyDebugLocation(CGF, false, SourceLocation());
 855   }
 856   /// Apply TemporaryLocation if it is valid. Otherwise switch
 857   /// to an artificial debug location that has a valid scope, but no
 858   /// line information.
 859   static ApplyDebugLocation
 860   CreateDefaultArtificial(CodeGenFunction &CGF,
 861                           SourceLocation TemporaryLocation) {
 862     return ApplyDebugLocation(CGF, false, TemporaryLocation);
 863   }
 864
 865   /// Set the IRBuilder to not attach debug locations.  Note that
 866   /// passing an empty SourceLocation to \a CGDebugInfo::setLocation()
 867   /// will result in the last valid location being reused.  Note that
 868   /// all instructions that do not have a location at the beginning of
 869   /// a function are counted towards to function prologue.
 870   static ApplyDebugLocation CreateEmpty(CodeGenFunction &CGF) {
 871     return ApplyDebugLocation(CGF, true, SourceLocation());
 872   }
 873 };
 874
 875 /// A scoped helper to set the current debug location to an inlined location.
 876 class ApplyInlineDebugLocation {
 877   SourceLocation SavedLocation;
 878   CodeGenFunction *CGF;
 879
 880 public:
 881   /// Set up the CodeGenFunction's DebugInfo to produce inline locations for the
 882   /// function \p InlinedFn. The current debug location becomes the inlined call
 883   /// site of the inlined function.
 884   ApplyInlineDebugLocation(CodeGenFunction &CGF, GlobalDecl InlinedFn);
 885   /// Restore everything back to the original state.
 886   ~ApplyInlineDebugLocation();
 887 };
 888
 889 } // namespace CodeGen
 890 } // namespace clang
 891
 892 #endif // LLVM_CLANG_LIB_CODEGEN_CGDEBUGINFO_H