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