xref: /freebsd/contrib/llvm-project/clang/lib/CodeGen/CGDebugInfo.h (revision e1c4c8dd8d2d10b6104f06856a77bd5b4813a801)
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 type for binding declarations.
341   llvm::DIType *CreateBindingDeclType(const BindingDecl *BD);
342 
343   /// Create an anonnymous zero-size separator for bit-field-decl if needed on
344   /// the target.
345   llvm::DIDerivedType *createBitFieldSeparatorIfNeeded(
346       const FieldDecl *BitFieldDecl, const llvm::DIDerivedType *BitFieldDI,
347       llvm::ArrayRef<llvm::Metadata *> PreviousFieldsDI, const RecordDecl *RD);
348 
349   /// Helpers for collecting fields of a record.
350   /// @{
351   void CollectRecordLambdaFields(const CXXRecordDecl *CXXDecl,
352                                  SmallVectorImpl<llvm::Metadata *> &E,
353                                  llvm::DIType *RecordTy);
354   llvm::DIDerivedType *CreateRecordStaticField(const VarDecl *Var,
355                                                llvm::DIType *RecordTy,
356                                                const RecordDecl *RD);
357   void CollectRecordNormalField(const FieldDecl *Field, uint64_t OffsetInBits,
358                                 llvm::DIFile *F,
359                                 SmallVectorImpl<llvm::Metadata *> &E,
360                                 llvm::DIType *RecordTy, const RecordDecl *RD);
361   void CollectRecordNestedType(const TypeDecl *RD,
362                                SmallVectorImpl<llvm::Metadata *> &E);
363   void CollectRecordFields(const RecordDecl *Decl, llvm::DIFile *F,
364                            SmallVectorImpl<llvm::Metadata *> &E,
365                            llvm::DICompositeType *RecordTy);
366 
367   /// If the C++ class has vtable info then insert appropriate debug
368   /// info entry in EltTys vector.
369   void CollectVTableInfo(const CXXRecordDecl *Decl, llvm::DIFile *F,
370                          SmallVectorImpl<llvm::Metadata *> &EltTys);
371   /// @}
372 
373   /// Create a new lexical block node and push it on the stack.
374   void CreateLexicalBlock(SourceLocation Loc);
375 
376   /// If target-specific LLVM \p AddressSpace directly maps to target-specific
377   /// DWARF address space, appends extended dereferencing mechanism to complex
378   /// expression \p Expr. Otherwise, does nothing.
379   ///
380   /// Extended dereferencing mechanism is has the following format:
381   ///     DW_OP_constu <DWARF Address Space> DW_OP_swap DW_OP_xderef
382   void AppendAddressSpaceXDeref(unsigned AddressSpace,
383                                 SmallVectorImpl<uint64_t> &Expr) const;
384 
385   /// A helper function to collect debug info for the default elements of a
386   /// block.
387   ///
388   /// \returns The next available field offset after the default elements.
389   uint64_t collectDefaultElementTypesForBlockPointer(
390       const BlockPointerType *Ty, llvm::DIFile *Unit,
391       llvm::DIDerivedType *DescTy, unsigned LineNo,
392       SmallVectorImpl<llvm::Metadata *> &EltTys);
393 
394   /// A helper function to collect debug info for the default fields of a
395   /// block.
396   void collectDefaultFieldsForBlockLiteralDeclare(
397       const CGBlockInfo &Block, const ASTContext &Context, SourceLocation Loc,
398       const llvm::StructLayout &BlockLayout, llvm::DIFile *Unit,
399       SmallVectorImpl<llvm::Metadata *> &Fields);
400 
401 public:
402   CGDebugInfo(CodeGenModule &CGM);
403   ~CGDebugInfo();
404 
405   void finalize();
406 
407   /// Remap a given path with the current debug prefix map
408   std::string remapDIPath(StringRef) const;
409 
410   /// Register VLA size expression debug node with the qualified type.
411   void registerVLASizeExpression(QualType Ty, llvm::Metadata *SizeExpr) {
412     SizeExprCache[Ty] = SizeExpr;
413   }
414 
415   /// Module debugging: Support for building PCMs.
416   /// @{
417   /// Set the main CU's DwoId field to \p Signature.
418   void setDwoId(uint64_t Signature);
419 
420   /// When generating debug information for a clang module or
421   /// precompiled header, this module map will be used to determine
422   /// the module of origin of each Decl.
423   void setModuleMap(ModuleMap &MMap) { ClangModuleMap = &MMap; }
424 
425   /// When generating debug information for a clang module or
426   /// precompiled header, this module map will be used to determine
427   /// the module of origin of each Decl.
428   void setPCHDescriptor(ASTSourceDescriptor PCH) { PCHDescriptor = PCH; }
429   /// @}
430 
431   /// Update the current source location. If \arg loc is invalid it is
432   /// ignored.
433   void setLocation(SourceLocation Loc);
434 
435   /// Return the current source location. This does not necessarily correspond
436   /// to the IRBuilder's current DebugLoc.
437   SourceLocation getLocation() const { return CurLoc; }
438 
439   /// Update the current inline scope. All subsequent calls to \p EmitLocation
440   /// will create a location with this inlinedAt field.
441   void setInlinedAt(llvm::MDNode *InlinedAt) { CurInlinedAt = InlinedAt; }
442 
443   /// \return the current inline scope.
444   llvm::MDNode *getInlinedAt() const { return CurInlinedAt; }
445 
446   // Converts a SourceLocation to a DebugLoc
447   llvm::DebugLoc SourceLocToDebugLoc(SourceLocation Loc);
448 
449   /// Emit metadata to indicate a change in line/column information in
450   /// the source file. If the location is invalid, the previous
451   /// location will be reused.
452   void EmitLocation(CGBuilderTy &Builder, SourceLocation Loc);
453 
454   QualType getFunctionType(const FunctionDecl *FD, QualType RetTy,
455                            const SmallVectorImpl<const VarDecl *> &Args);
456 
457   /// Emit a call to llvm.dbg.function.start to indicate
458   /// start of a new function.
459   /// \param Loc       The location of the function header.
460   /// \param ScopeLoc  The location of the function body.
461   void emitFunctionStart(GlobalDecl GD, SourceLocation Loc,
462                          SourceLocation ScopeLoc, QualType FnType,
463                          llvm::Function *Fn, bool CurFnIsThunk);
464 
465   /// Start a new scope for an inlined function.
466   void EmitInlineFunctionStart(CGBuilderTy &Builder, GlobalDecl GD);
467   /// End an inlined function scope.
468   void EmitInlineFunctionEnd(CGBuilderTy &Builder);
469 
470   /// Emit debug info for a function declaration.
471   /// \p Fn is set only when a declaration for a debug call site gets created.
472   void EmitFunctionDecl(GlobalDecl GD, SourceLocation Loc,
473                         QualType FnType, llvm::Function *Fn = nullptr);
474 
475   /// Emit debug info for an extern function being called.
476   /// This is needed for call site debug info.
477   void EmitFuncDeclForCallSite(llvm::CallBase *CallOrInvoke,
478                                QualType CalleeType,
479                                const FunctionDecl *CalleeDecl);
480 
481   /// Constructs the debug code for exiting a function.
482   void EmitFunctionEnd(CGBuilderTy &Builder, llvm::Function *Fn);
483 
484   /// Emit metadata to indicate the beginning of a new lexical block
485   /// and push the block onto the stack.
486   void EmitLexicalBlockStart(CGBuilderTy &Builder, SourceLocation Loc);
487 
488   /// Emit metadata to indicate the end of a new lexical block and pop
489   /// the current block.
490   void EmitLexicalBlockEnd(CGBuilderTy &Builder, SourceLocation Loc);
491 
492   /// Emit call to \c llvm.dbg.declare for an automatic variable
493   /// declaration.
494   /// Returns a pointer to the DILocalVariable associated with the
495   /// llvm.dbg.declare, or nullptr otherwise.
496   llvm::DILocalVariable *
497   EmitDeclareOfAutoVariable(const VarDecl *Decl, llvm::Value *AI,
498                             CGBuilderTy &Builder,
499                             const bool UsePointerValue = false);
500 
501   /// Emit call to \c llvm.dbg.label for an label.
502   void EmitLabel(const LabelDecl *D, CGBuilderTy &Builder);
503 
504   /// Emit call to \c llvm.dbg.declare for an imported variable
505   /// declaration in a block.
506   void EmitDeclareOfBlockDeclRefVariable(
507       const VarDecl *variable, llvm::Value *storage, CGBuilderTy &Builder,
508       const CGBlockInfo &blockInfo, llvm::Instruction *InsertPoint = nullptr);
509 
510   /// Emit call to \c llvm.dbg.declare for an argument variable
511   /// declaration.
512   llvm::DILocalVariable *
513   EmitDeclareOfArgVariable(const VarDecl *Decl, llvm::Value *AI, unsigned ArgNo,
514                            CGBuilderTy &Builder, bool UsePointerValue = false);
515 
516   /// Emit call to \c llvm.dbg.declare for the block-literal argument
517   /// to a block invocation function.
518   void EmitDeclareOfBlockLiteralArgVariable(const CGBlockInfo &block,
519                                             StringRef Name, unsigned ArgNo,
520                                             llvm::AllocaInst *LocalAddr,
521                                             CGBuilderTy &Builder);
522 
523   /// Emit information about a global variable.
524   void EmitGlobalVariable(llvm::GlobalVariable *GV, const VarDecl *Decl);
525 
526   /// Emit a constant global variable's debug info.
527   void EmitGlobalVariable(const ValueDecl *VD, const APValue &Init);
528 
529   /// Emit information about an external variable.
530   void EmitExternalVariable(llvm::GlobalVariable *GV, const VarDecl *Decl);
531 
532   /// Emit information about global variable alias.
533   void EmitGlobalAlias(const llvm::GlobalValue *GV, const GlobalDecl Decl);
534 
535   /// Emit C++ using directive.
536   void EmitUsingDirective(const UsingDirectiveDecl &UD);
537 
538   /// Emit the type explicitly casted to.
539   void EmitExplicitCastType(QualType Ty);
540 
541   /// Emit the type even if it might not be used.
542   void EmitAndRetainType(QualType Ty);
543 
544   /// Emit a shadow decl brought in by a using or using-enum
545   void EmitUsingShadowDecl(const UsingShadowDecl &USD);
546 
547   /// Emit C++ using declaration.
548   void EmitUsingDecl(const UsingDecl &UD);
549 
550   /// Emit C++ using-enum declaration.
551   void EmitUsingEnumDecl(const UsingEnumDecl &UD);
552 
553   /// Emit an @import declaration.
554   void EmitImportDecl(const ImportDecl &ID);
555 
556   /// DebugInfo isn't attached to string literals by default. While certain
557   /// aspects of debuginfo aren't useful for string literals (like a name), it's
558   /// nice to be able to symbolize the line and column information. This is
559   /// especially useful for sanitizers, as it allows symbolization of
560   /// heap-buffer-overflows on constant strings.
561   void AddStringLiteralDebugInfo(llvm::GlobalVariable *GV,
562                                  const StringLiteral *S);
563 
564   /// Emit C++ namespace alias.
565   llvm::DIImportedEntity *EmitNamespaceAlias(const NamespaceAliasDecl &NA);
566 
567   /// Emit record type's standalone debug info.
568   llvm::DIType *getOrCreateRecordType(QualType Ty, SourceLocation L);
569 
570   /// Emit an Objective-C interface type standalone debug info.
571   llvm::DIType *getOrCreateInterfaceType(QualType Ty, SourceLocation Loc);
572 
573   /// Emit standalone debug info for a type.
574   llvm::DIType *getOrCreateStandaloneType(QualType Ty, SourceLocation Loc);
575 
576   /// Add heapallocsite metadata for MSAllocator calls.
577   void addHeapAllocSiteMetadata(llvm::CallBase *CallSite, QualType AllocatedTy,
578                                 SourceLocation Loc);
579 
580   void completeType(const EnumDecl *ED);
581   void completeType(const RecordDecl *RD);
582   void completeRequiredType(const RecordDecl *RD);
583   void completeClassData(const RecordDecl *RD);
584   void completeClass(const RecordDecl *RD);
585 
586   void completeTemplateDefinition(const ClassTemplateSpecializationDecl &SD);
587   void completeUnusedClass(const CXXRecordDecl &D);
588 
589   /// Create debug info for a macro defined by a #define directive or a macro
590   /// undefined by a #undef directive.
591   llvm::DIMacro *CreateMacro(llvm::DIMacroFile *Parent, unsigned MType,
592                              SourceLocation LineLoc, StringRef Name,
593                              StringRef Value);
594 
595   /// Create debug info for a file referenced by an #include directive.
596   llvm::DIMacroFile *CreateTempMacroFile(llvm::DIMacroFile *Parent,
597                                          SourceLocation LineLoc,
598                                          SourceLocation FileLoc);
599 
600   Param2DILocTy &getParamDbgMappings() { return ParamDbgMappings; }
601   ParamDecl2StmtTy &getCoroutineParameterMappings() {
602     return CoroutineParameterMappings;
603   }
604 
605 private:
606   /// Emit call to llvm.dbg.declare for a variable declaration.
607   /// Returns a pointer to the DILocalVariable associated with the
608   /// llvm.dbg.declare, or nullptr otherwise.
609   llvm::DILocalVariable *EmitDeclare(const VarDecl *decl, llvm::Value *AI,
610                                      std::optional<unsigned> ArgNo,
611                                      CGBuilderTy &Builder,
612                                      const bool UsePointerValue = false);
613 
614   /// Emit call to llvm.dbg.declare for a binding declaration.
615   /// Returns a pointer to the DILocalVariable associated with the
616   /// llvm.dbg.declare, or nullptr otherwise.
617   llvm::DILocalVariable *EmitDeclare(const BindingDecl *decl, llvm::Value *AI,
618                                      std::optional<unsigned> ArgNo,
619                                      CGBuilderTy &Builder,
620                                      const bool UsePointerValue = false);
621 
622   struct BlockByRefType {
623     /// The wrapper struct used inside the __block_literal struct.
624     llvm::DIType *BlockByRefWrapper;
625     /// The type as it appears in the source code.
626     llvm::DIType *WrappedType;
627   };
628 
629   std::string GetName(const Decl*, bool Qualified = false) const;
630 
631   /// Build up structure info for the byref.  See \a BuildByRefType.
632   BlockByRefType EmitTypeForVarWithBlocksAttr(const VarDecl *VD,
633                                               uint64_t *OffSet);
634 
635   /// Get context info for the DeclContext of \p Decl.
636   llvm::DIScope *getDeclContextDescriptor(const Decl *D);
637   /// Get context info for a given DeclContext \p Decl.
638   llvm::DIScope *getContextDescriptor(const Decl *Context,
639                                       llvm::DIScope *Default);
640 
641   llvm::DIScope *getCurrentContextDescriptor(const Decl *Decl);
642 
643   /// Create a forward decl for a RecordType in a given context.
644   llvm::DICompositeType *getOrCreateRecordFwdDecl(const RecordType *,
645                                                   llvm::DIScope *);
646 
647   /// Return current directory name.
648   StringRef getCurrentDirname();
649 
650   /// Create new compile unit.
651   void CreateCompileUnit();
652 
653   /// Compute the file checksum debug info for input file ID.
654   std::optional<llvm::DIFile::ChecksumKind>
655   computeChecksum(FileID FID, SmallString<64> &Checksum) const;
656 
657   /// Get the source of the given file ID.
658   std::optional<StringRef> getSource(const SourceManager &SM, FileID FID);
659 
660   /// Convenience function to get the file debug info descriptor for the input
661   /// location.
662   llvm::DIFile *getOrCreateFile(SourceLocation Loc);
663 
664   /// Create a file debug info descriptor for a source file.
665   llvm::DIFile *
666   createFile(StringRef FileName,
667              std::optional<llvm::DIFile::ChecksumInfo<StringRef>> CSInfo,
668              std::optional<StringRef> Source);
669 
670   /// Get the type from the cache or create a new type if necessary.
671   llvm::DIType *getOrCreateType(QualType Ty, llvm::DIFile *Fg);
672 
673   /// Get a reference to a clang module.  If \p CreateSkeletonCU is true,
674   /// this also creates a split dwarf skeleton compile unit.
675   llvm::DIModule *getOrCreateModuleRef(ASTSourceDescriptor Mod,
676                                        bool CreateSkeletonCU);
677 
678   /// DebugTypeExtRefs: If \p D originated in a clang module, return it.
679   llvm::DIModule *getParentModuleOrNull(const Decl *D);
680 
681   /// Get the type from the cache or create a new partial type if
682   /// necessary.
683   llvm::DICompositeType *getOrCreateLimitedType(const RecordType *Ty);
684 
685   /// Create type metadata for a source language type.
686   llvm::DIType *CreateTypeNode(QualType Ty, llvm::DIFile *Fg);
687 
688   /// Create new member and increase Offset by FType's size.
689   llvm::DIType *CreateMemberType(llvm::DIFile *Unit, QualType FType,
690                                  StringRef Name, uint64_t *Offset);
691 
692   /// Retrieve the DIDescriptor, if any, for the canonical form of this
693   /// declaration.
694   llvm::DINode *getDeclarationOrDefinition(const Decl *D);
695 
696   /// \return debug info descriptor to describe method
697   /// declaration for the given method definition.
698   llvm::DISubprogram *getFunctionDeclaration(const Decl *D);
699 
700   /// \return          debug info descriptor to the describe method declaration
701   ///                  for the given method definition.
702   /// \param FnType    For Objective-C methods, their type.
703   /// \param LineNo    The declaration's line number.
704   /// \param Flags     The DIFlags for the method declaration.
705   /// \param SPFlags   The subprogram-spcific flags for the method declaration.
706   llvm::DISubprogram *
707   getObjCMethodDeclaration(const Decl *D, llvm::DISubroutineType *FnType,
708                            unsigned LineNo, llvm::DINode::DIFlags Flags,
709                            llvm::DISubprogram::DISPFlags SPFlags);
710 
711   /// \return debug info descriptor to describe in-class static data
712   /// member declaration for the given out-of-class definition.  If D
713   /// is an out-of-class definition of a static data member of a
714   /// class, find its corresponding in-class declaration.
715   llvm::DIDerivedType *
716   getOrCreateStaticDataMemberDeclarationOrNull(const VarDecl *D);
717 
718   /// Helper that either creates a forward declaration or a stub.
719   llvm::DISubprogram *getFunctionFwdDeclOrStub(GlobalDecl GD, bool Stub);
720 
721   /// Create a subprogram describing the forward declaration
722   /// represented in the given FunctionDecl wrapped in a GlobalDecl.
723   llvm::DISubprogram *getFunctionForwardDeclaration(GlobalDecl GD);
724 
725   /// Create a DISubprogram describing the function
726   /// represented in the given FunctionDecl wrapped in a GlobalDecl.
727   llvm::DISubprogram *getFunctionStub(GlobalDecl GD);
728 
729   /// Create a global variable describing the forward declaration
730   /// represented in the given VarDecl.
731   llvm::DIGlobalVariable *
732   getGlobalVariableForwardDeclaration(const VarDecl *VD);
733 
734   /// Return a global variable that represents one of the collection of global
735   /// variables created for an anonmyous union.
736   ///
737   /// Recursively collect all of the member fields of a global
738   /// anonymous decl and create static variables for them. The first
739   /// time this is called it needs to be on a union and then from
740   /// there we can have additional unnamed fields.
741   llvm::DIGlobalVariableExpression *
742   CollectAnonRecordDecls(const RecordDecl *RD, llvm::DIFile *Unit,
743                          unsigned LineNo, StringRef LinkageName,
744                          llvm::GlobalVariable *Var, llvm::DIScope *DContext);
745 
746 
747   /// Return flags which enable debug info emission for call sites, provided
748   /// that it is supported and enabled.
749   llvm::DINode::DIFlags getCallSiteRelatedAttrs() const;
750 
751   /// Get the printing policy for producing names for debug info.
752   PrintingPolicy getPrintingPolicy() const;
753 
754   /// Get function name for the given FunctionDecl. If the name is
755   /// constructed on demand (e.g., C++ destructor) then the name is
756   /// stored on the side.
757   StringRef getFunctionName(const FunctionDecl *FD);
758 
759   /// Returns the unmangled name of an Objective-C method.
760   /// This is the display name for the debugging info.
761   StringRef getObjCMethodName(const ObjCMethodDecl *FD);
762 
763   /// Return selector name. This is used for debugging
764   /// info.
765   StringRef getSelectorName(Selector S);
766 
767   /// Get class name including template argument list.
768   StringRef getClassName(const RecordDecl *RD);
769 
770   /// Get the vtable name for the given class.
771   StringRef getVTableName(const CXXRecordDecl *Decl);
772 
773   /// Get the name to use in the debug info for a dynamic initializer or atexit
774   /// stub function.
775   StringRef getDynamicInitializerName(const VarDecl *VD,
776                                       DynamicInitKind StubKind,
777                                       llvm::Function *InitFn);
778 
779   /// Get line number for the location. If location is invalid
780   /// then use current location.
781   unsigned getLineNumber(SourceLocation Loc);
782 
783   /// Get column number for the location. If location is
784   /// invalid then use current location.
785   /// \param Force  Assume DebugColumnInfo option is true.
786   unsigned getColumnNumber(SourceLocation Loc, bool Force = false);
787 
788   /// Collect various properties of a FunctionDecl.
789   /// \param GD  A GlobalDecl whose getDecl() must return a FunctionDecl.
790   void collectFunctionDeclProps(GlobalDecl GD, llvm::DIFile *Unit,
791                                 StringRef &Name, StringRef &LinkageName,
792                                 llvm::DIScope *&FDContext,
793                                 llvm::DINodeArray &TParamsArray,
794                                 llvm::DINode::DIFlags &Flags);
795 
796   /// Collect various properties of a VarDecl.
797   void collectVarDeclProps(const VarDecl *VD, llvm::DIFile *&Unit,
798                            unsigned &LineNo, QualType &T, StringRef &Name,
799                            StringRef &LinkageName,
800                            llvm::MDTuple *&TemplateParameters,
801                            llvm::DIScope *&VDContext);
802 
803   /// Create a DIExpression representing the constant corresponding
804   /// to the specified 'Val'. Returns nullptr on failure.
805   llvm::DIExpression *createConstantValueExpression(const clang::ValueDecl *VD,
806                                                     const APValue &Val);
807 
808   /// Allocate a copy of \p A using the DebugInfoNames allocator
809   /// and return a reference to it. If multiple arguments are given the strings
810   /// are concatenated.
811   StringRef internString(StringRef A, StringRef B = StringRef()) {
812     char *Data = DebugInfoNames.Allocate<char>(A.size() + B.size());
813     if (!A.empty())
814       std::memcpy(Data, A.data(), A.size());
815     if (!B.empty())
816       std::memcpy(Data + A.size(), B.data(), B.size());
817     return StringRef(Data, A.size() + B.size());
818   }
819 };
820 
821 /// A scoped helper to set the current debug location to the specified
822 /// location or preferred location of the specified Expr.
823 class ApplyDebugLocation {
824 private:
825   void init(SourceLocation TemporaryLocation, bool DefaultToEmpty = false);
826   ApplyDebugLocation(CodeGenFunction &CGF, bool DefaultToEmpty,
827                      SourceLocation TemporaryLocation);
828 
829   llvm::DebugLoc OriginalLocation;
830   CodeGenFunction *CGF;
831 
832 public:
833   /// Set the location to the (valid) TemporaryLocation.
834   ApplyDebugLocation(CodeGenFunction &CGF, SourceLocation TemporaryLocation);
835   ApplyDebugLocation(CodeGenFunction &CGF, const Expr *E);
836   ApplyDebugLocation(CodeGenFunction &CGF, llvm::DebugLoc Loc);
837   ApplyDebugLocation(ApplyDebugLocation &&Other) : CGF(Other.CGF) {
838     Other.CGF = nullptr;
839   }
840 
841   // Define copy assignment operator.
842   ApplyDebugLocation &operator=(ApplyDebugLocation &&Other) {
843     if (this != &Other) {
844       CGF = Other.CGF;
845       Other.CGF = nullptr;
846     }
847     return *this;
848   }
849 
850   ~ApplyDebugLocation();
851 
852   /// Apply TemporaryLocation if it is valid. Otherwise switch
853   /// to an artificial debug location that has a valid scope, but no
854   /// line information.
855   ///
856   /// Artificial locations are useful when emitting compiler-generated
857   /// helper functions that have no source location associated with
858   /// them. The DWARF specification allows the compiler to use the
859   /// special line number 0 to indicate code that can not be
860   /// attributed to any source location. Note that passing an empty
861   /// SourceLocation to CGDebugInfo::setLocation() will result in the
862   /// last valid location being reused.
863   static ApplyDebugLocation CreateArtificial(CodeGenFunction &CGF) {
864     return ApplyDebugLocation(CGF, false, SourceLocation());
865   }
866   /// Apply TemporaryLocation if it is valid. Otherwise switch
867   /// to an artificial debug location that has a valid scope, but no
868   /// line information.
869   static ApplyDebugLocation
870   CreateDefaultArtificial(CodeGenFunction &CGF,
871                           SourceLocation TemporaryLocation) {
872     return ApplyDebugLocation(CGF, false, TemporaryLocation);
873   }
874 
875   /// Set the IRBuilder to not attach debug locations.  Note that
876   /// passing an empty SourceLocation to \a CGDebugInfo::setLocation()
877   /// will result in the last valid location being reused.  Note that
878   /// all instructions that do not have a location at the beginning of
879   /// a function are counted towards to function prologue.
880   static ApplyDebugLocation CreateEmpty(CodeGenFunction &CGF) {
881     return ApplyDebugLocation(CGF, true, SourceLocation());
882   }
883 };
884 
885 /// A scoped helper to set the current debug location to an inlined location.
886 class ApplyInlineDebugLocation {
887   SourceLocation SavedLocation;
888   CodeGenFunction *CGF;
889 
890 public:
891   /// Set up the CodeGenFunction's DebugInfo to produce inline locations for the
892   /// function \p InlinedFn. The current debug location becomes the inlined call
893   /// site of the inlined function.
894   ApplyInlineDebugLocation(CodeGenFunction &CGF, GlobalDecl InlinedFn);
895   /// Restore everything back to the original state.
896   ~ApplyInlineDebugLocation();
897 };
898 
899 } // namespace CodeGen
900 } // namespace clang
901 
902 #endif // LLVM_CLANG_LIB_CODEGEN_CGDEBUGINFO_H
903