xref: /freebsd/contrib/llvm-project/clang/lib/CodeGen/CGDebugInfo.h (revision 5e801ac66d24704442eba426ed13c3effb8a34e7)
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 ObjCIvarDecl;
44 class UsingDecl;
45 class VarDecl;
46 enum class DynamicInitKind : unsigned;
47 
48 namespace CodeGen {
49 class CodeGenModule;
50 class CodeGenFunction;
51 class CGBlockInfo;
52 
53 /// This class gathers all debug information during compilation and is
54 /// responsible for emitting to llvm globals or pass directly to the
55 /// backend.
56 class CGDebugInfo {
57   friend class ApplyDebugLocation;
58   friend class SaveAndRestoreLocation;
59   CodeGenModule &CGM;
60   const codegenoptions::DebugInfoKind DebugKind;
61   bool DebugTypeExtRefs;
62   llvm::DIBuilder DBuilder;
63   llvm::DICompileUnit *TheCU = nullptr;
64   ModuleMap *ClangModuleMap = nullptr;
65   ASTSourceDescriptor PCHDescriptor;
66   SourceLocation CurLoc;
67   llvm::MDNode *CurInlinedAt = nullptr;
68   llvm::DIType *VTablePtrType = nullptr;
69   llvm::DIType *ClassTy = nullptr;
70   llvm::DICompositeType *ObjTy = nullptr;
71   llvm::DIType *SelTy = nullptr;
72 #define IMAGE_TYPE(ImgType, Id, SingletonId, Access, Suffix)                   \
73   llvm::DIType *SingletonId = nullptr;
74 #include "clang/Basic/OpenCLImageTypes.def"
75   llvm::DIType *OCLSamplerDITy = nullptr;
76   llvm::DIType *OCLEventDITy = nullptr;
77   llvm::DIType *OCLClkEventDITy = nullptr;
78   llvm::DIType *OCLQueueDITy = nullptr;
79   llvm::DIType *OCLNDRangeDITy = nullptr;
80   llvm::DIType *OCLReserveIDDITy = nullptr;
81 #define EXT_OPAQUE_TYPE(ExtType, Id, Ext) \
82   llvm::DIType *Id##Ty = nullptr;
83 #include "clang/Basic/OpenCLExtensionTypes.def"
84 
85   /// Cache of previously constructed Types.
86   llvm::DenseMap<const void *, llvm::TrackingMDRef> TypeCache;
87 
88   std::map<llvm::StringRef, llvm::StringRef, std::greater<llvm::StringRef>>
89       DebugPrefixMap;
90 
91   /// Cache that maps VLA types to size expressions for that type,
92   /// represented by instantiated Metadata nodes.
93   llvm::SmallDenseMap<QualType, llvm::Metadata *> SizeExprCache;
94 
95   /// Callbacks to use when printing names and types.
96   class PrintingCallbacks final : public clang::PrintingCallbacks {
97     const CGDebugInfo &Self;
98 
99   public:
100     PrintingCallbacks(const CGDebugInfo &Self) : Self(Self) {}
101     std::string remapPath(StringRef Path) const override {
102       return Self.remapDIPath(Path);
103     }
104   };
105   PrintingCallbacks PrintCB = {*this};
106 
107   struct ObjCInterfaceCacheEntry {
108     const ObjCInterfaceType *Type;
109     llvm::DIType *Decl;
110     llvm::DIFile *Unit;
111     ObjCInterfaceCacheEntry(const ObjCInterfaceType *Type, llvm::DIType *Decl,
112                             llvm::DIFile *Unit)
113         : Type(Type), Decl(Decl), Unit(Unit) {}
114   };
115 
116   /// Cache of previously constructed interfaces which may change.
117   llvm::SmallVector<ObjCInterfaceCacheEntry, 32> ObjCInterfaceCache;
118 
119   /// Cache of forward declarations for methods belonging to the interface.
120   /// The extra bit on the DISubprogram specifies whether a method is
121   /// "objc_direct".
122   llvm::DenseMap<const ObjCInterfaceDecl *,
123                  std::vector<llvm::PointerIntPair<llvm::DISubprogram *, 1>>>
124       ObjCMethodCache;
125 
126   /// Cache of references to clang modules and precompiled headers.
127   llvm::DenseMap<const Module *, llvm::TrackingMDRef> ModuleCache;
128 
129   /// List of interfaces we want to keep even if orphaned.
130   std::vector<void *> RetainedTypes;
131 
132   /// Cache of forward declared types to RAUW at the end of compilation.
133   std::vector<std::pair<const TagType *, llvm::TrackingMDRef>> ReplaceMap;
134 
135   /// Cache of replaceable forward declarations (functions and
136   /// variables) to RAUW at the end of compilation.
137   std::vector<std::pair<const DeclaratorDecl *, llvm::TrackingMDRef>>
138       FwdDeclReplaceMap;
139 
140   /// Keep track of our current nested lexical block.
141   std::vector<llvm::TypedTrackingMDRef<llvm::DIScope>> LexicalBlockStack;
142   llvm::DenseMap<const Decl *, llvm::TrackingMDRef> RegionMap;
143   /// Keep track of LexicalBlockStack counter at the beginning of a
144   /// function. This is used to pop unbalanced regions at the end of a
145   /// function.
146   std::vector<unsigned> FnBeginRegionCount;
147 
148   /// This is a storage for names that are constructed on demand. For
149   /// example, C++ destructors, C++ operators etc..
150   llvm::BumpPtrAllocator DebugInfoNames;
151   StringRef CWDName;
152 
153   llvm::DenseMap<const char *, llvm::TrackingMDRef> DIFileCache;
154   llvm::DenseMap<const FunctionDecl *, llvm::TrackingMDRef> SPCache;
155   /// Cache declarations relevant to DW_TAG_imported_declarations (C++
156   /// using declarations) that aren't covered by other more specific caches.
157   llvm::DenseMap<const Decl *, llvm::TrackingMDRef> DeclCache;
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 AutoType *Ty);
180   llvm::DIType *CreateType(const ExtIntType *Ty);
181   llvm::DIType *CreateQualifiedType(QualType Ty, llvm::DIFile *Fg,
182                                     TypeLoc TL = TypeLoc());
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                            TypeLoc TL = TypeLoc());
191   llvm::DIType *CreateType(const BlockPointerType *Ty, llvm::DIFile *F);
192   llvm::DIType *CreateType(const FunctionType *Ty, llvm::DIFile *F,
193                            TypeLoc TL = TypeLoc());
194   /// Get structure or union type.
195   llvm::DIType *CreateType(const RecordType *Tyg);
196   llvm::DIType *CreateTypeDefinition(const RecordType *Ty);
197   llvm::DICompositeType *CreateLimitedType(const RecordType *Ty);
198   void CollectContainingType(const CXXRecordDecl *RD,
199                              llvm::DICompositeType *CT);
200   /// Get Objective-C interface type.
201   llvm::DIType *CreateType(const ObjCInterfaceType *Ty, llvm::DIFile *F);
202   llvm::DIType *CreateTypeDefinition(const ObjCInterfaceType *Ty,
203                                      llvm::DIFile *F);
204   /// Get Objective-C object type.
205   llvm::DIType *CreateType(const ObjCObjectType *Ty, llvm::DIFile *F);
206   llvm::DIType *CreateType(const ObjCTypeParamType *Ty, llvm::DIFile *Unit);
207 
208   llvm::DIType *CreateType(const VectorType *Ty, llvm::DIFile *F);
209   llvm::DIType *CreateType(const ConstantMatrixType *Ty, llvm::DIFile *F);
210   llvm::DIType *CreateType(const ArrayType *Ty, llvm::DIFile *F);
211   llvm::DIType *CreateType(const LValueReferenceType *Ty, llvm::DIFile *F);
212   llvm::DIType *CreateType(const RValueReferenceType *Ty, llvm::DIFile *Unit);
213   llvm::DIType *CreateType(const MemberPointerType *Ty, llvm::DIFile *F);
214   llvm::DIType *CreateType(const AtomicType *Ty, llvm::DIFile *F);
215   llvm::DIType *CreateType(const PipeType *Ty, llvm::DIFile *F);
216   /// Get enumeration type.
217   llvm::DIType *CreateEnumType(const EnumType *Ty);
218   llvm::DIType *CreateTypeDefinition(const EnumType *Ty);
219   /// Look up the completed type for a self pointer in the TypeCache and
220   /// create a copy of it with the ObjectPointer and Artificial flags
221   /// set. If the type is not cached, a new one is created. This should
222   /// never happen though, since creating a type for the implicit self
223   /// argument implies that we already parsed the interface definition
224   /// and the ivar declarations in the implementation.
225   llvm::DIType *CreateSelfType(const QualType &QualTy, llvm::DIType *Ty);
226   /// @}
227 
228   /// Get the type from the cache or return null type if it doesn't
229   /// exist.
230   llvm::DIType *getTypeOrNull(const QualType);
231   /// Return the debug type for a C++ method.
232   /// \arg CXXMethodDecl is of FunctionType. This function type is
233   /// not updated to include implicit \c this pointer. Use this routine
234   /// to get a method type which includes \c this pointer.
235   llvm::DISubroutineType *getOrCreateMethodType(const CXXMethodDecl *Method,
236                                                 llvm::DIFile *F, bool decl);
237   llvm::DISubroutineType *
238   getOrCreateInstanceMethodType(QualType ThisPtr, const FunctionProtoType *Func,
239                                 llvm::DIFile *Unit, bool decl);
240   llvm::DISubroutineType *
241   getOrCreateFunctionType(const Decl *D, QualType FnType, llvm::DIFile *F);
242   /// \return debug info descriptor for vtable.
243   llvm::DIType *getOrCreateVTablePtrType(llvm::DIFile *F);
244 
245   /// \return namespace descriptor for the given namespace decl.
246   llvm::DINamespace *getOrCreateNamespace(const NamespaceDecl *N);
247   llvm::DIType *CreatePointerLikeType(llvm::dwarf::Tag Tag, const Type *Ty,
248                                       QualType PointeeTy, llvm::DIFile *F,
249                                       TypeLoc TL = TypeLoc());
250   llvm::DIType *getOrCreateStructPtrType(StringRef Name, llvm::DIType *&Cache);
251 
252   /// A helper function to create a subprogram for a single member
253   /// function GlobalDecl.
254   llvm::DISubprogram *CreateCXXMemberFunction(const CXXMethodDecl *Method,
255                                               llvm::DIFile *F,
256                                               llvm::DIType *RecordTy);
257 
258   /// A helper function to collect debug info for C++ member
259   /// functions. This is used while creating debug info entry for a
260   /// Record.
261   void CollectCXXMemberFunctions(const CXXRecordDecl *Decl, llvm::DIFile *F,
262                                  SmallVectorImpl<llvm::Metadata *> &E,
263                                  llvm::DIType *T);
264 
265   /// A helper function to collect debug info for C++ base
266   /// classes. This is used while creating debug info entry for a
267   /// Record.
268   void CollectCXXBases(const CXXRecordDecl *Decl, llvm::DIFile *F,
269                        SmallVectorImpl<llvm::Metadata *> &EltTys,
270                        llvm::DIType *RecordTy);
271 
272   /// Helper function for CollectCXXBases.
273   /// Adds debug info entries for types in Bases that are not in SeenTypes.
274   void CollectCXXBasesAux(
275       const CXXRecordDecl *RD, llvm::DIFile *Unit,
276       SmallVectorImpl<llvm::Metadata *> &EltTys, llvm::DIType *RecordTy,
277       const CXXRecordDecl::base_class_const_range &Bases,
278       llvm::DenseSet<CanonicalDeclPtr<const CXXRecordDecl>> &SeenTypes,
279       llvm::DINode::DIFlags StartingFlags);
280 
281   struct TemplateArgs {
282     const TemplateParameterList *TList;
283     llvm::ArrayRef<TemplateArgument> Args;
284   };
285   /// A helper function to collect template parameters.
286   llvm::DINodeArray CollectTemplateParams(Optional<TemplateArgs> Args,
287                                           llvm::DIFile *Unit);
288   /// A helper function to collect debug info for function template
289   /// parameters.
290   llvm::DINodeArray CollectFunctionTemplateParams(const FunctionDecl *FD,
291                                                   llvm::DIFile *Unit);
292 
293   /// A helper function to collect debug info for function template
294   /// parameters.
295   llvm::DINodeArray CollectVarTemplateParams(const VarDecl *VD,
296                                              llvm::DIFile *Unit);
297 
298   Optional<TemplateArgs> GetTemplateArgs(const VarDecl *) const;
299   Optional<TemplateArgs> GetTemplateArgs(const RecordDecl *) const;
300   Optional<TemplateArgs> GetTemplateArgs(const FunctionDecl *) const;
301 
302   /// A helper function to collect debug info for template
303   /// parameters.
304   llvm::DINodeArray CollectCXXTemplateParams(const RecordDecl *TS,
305                                              llvm::DIFile *F);
306 
307   /// A helper function to collect debug info for btf_decl_tag annotations.
308   llvm::DINodeArray CollectBTFDeclTagAnnotations(const Decl *D);
309 
310   llvm::DIType *createFieldType(StringRef name, QualType type,
311                                 SourceLocation loc, AccessSpecifier AS,
312                                 uint64_t offsetInBits, uint32_t AlignInBits,
313                                 llvm::DIFile *tunit, llvm::DIScope *scope,
314                                 const RecordDecl *RD = nullptr,
315                                 llvm::DINodeArray Annotations = nullptr,
316                                 TypeLoc TL = TypeLoc());
317 
318   llvm::DIType *createFieldType(StringRef name, QualType type,
319                                 SourceLocation loc, AccessSpecifier AS,
320                                 uint64_t offsetInBits, llvm::DIFile *tunit,
321                                 llvm::DIScope *scope,
322                                 const RecordDecl *RD = nullptr) {
323     return createFieldType(name, type, loc, AS, offsetInBits, 0, tunit, scope,
324                            RD);
325   }
326 
327   /// Create new bit field member.
328   llvm::DIType *createBitFieldType(const FieldDecl *BitFieldDecl,
329                                    llvm::DIScope *RecordTy,
330                                    const RecordDecl *RD);
331 
332   /// Helpers for collecting fields of a record.
333   /// @{
334   void CollectRecordLambdaFields(const CXXRecordDecl *CXXDecl,
335                                  SmallVectorImpl<llvm::Metadata *> &E,
336                                  llvm::DIType *RecordTy);
337   llvm::DIDerivedType *CreateRecordStaticField(const VarDecl *Var,
338                                                llvm::DIType *RecordTy,
339                                                const RecordDecl *RD);
340   void CollectRecordNormalField(const FieldDecl *Field, uint64_t OffsetInBits,
341                                 llvm::DIFile *F,
342                                 SmallVectorImpl<llvm::Metadata *> &E,
343                                 llvm::DIType *RecordTy, const RecordDecl *RD);
344   void CollectRecordNestedType(const TypeDecl *RD,
345                                SmallVectorImpl<llvm::Metadata *> &E);
346   void CollectRecordFields(const RecordDecl *Decl, llvm::DIFile *F,
347                            SmallVectorImpl<llvm::Metadata *> &E,
348                            llvm::DICompositeType *RecordTy);
349 
350   /// If the C++ class has vtable info then insert appropriate debug
351   /// info entry in EltTys vector.
352   void CollectVTableInfo(const CXXRecordDecl *Decl, llvm::DIFile *F,
353                          SmallVectorImpl<llvm::Metadata *> &EltTys);
354   /// @}
355 
356   /// Create a new lexical block node and push it on the stack.
357   void CreateLexicalBlock(SourceLocation Loc);
358 
359   /// If target-specific LLVM \p AddressSpace directly maps to target-specific
360   /// DWARF address space, appends extended dereferencing mechanism to complex
361   /// expression \p Expr. Otherwise, does nothing.
362   ///
363   /// Extended dereferencing mechanism is has the following format:
364   ///     DW_OP_constu <DWARF Address Space> DW_OP_swap DW_OP_xderef
365   void AppendAddressSpaceXDeref(unsigned AddressSpace,
366                                 SmallVectorImpl<int64_t> &Expr) const;
367 
368   /// A helper function to collect debug info for the default elements of a
369   /// block.
370   ///
371   /// \returns The next available field offset after the default elements.
372   uint64_t collectDefaultElementTypesForBlockPointer(
373       const BlockPointerType *Ty, llvm::DIFile *Unit,
374       llvm::DIDerivedType *DescTy, unsigned LineNo,
375       SmallVectorImpl<llvm::Metadata *> &EltTys);
376 
377   /// A helper function to collect debug info for the default fields of a
378   /// block.
379   void collectDefaultFieldsForBlockLiteralDeclare(
380       const CGBlockInfo &Block, const ASTContext &Context, SourceLocation Loc,
381       const llvm::StructLayout &BlockLayout, llvm::DIFile *Unit,
382       SmallVectorImpl<llvm::Metadata *> &Fields);
383 
384 public:
385   CGDebugInfo(CodeGenModule &CGM);
386   ~CGDebugInfo();
387 
388   void finalize();
389 
390   /// Remap a given path with the current debug prefix map
391   std::string remapDIPath(StringRef) const;
392 
393   /// Register VLA size expression debug node with the qualified type.
394   void registerVLASizeExpression(QualType Ty, llvm::Metadata *SizeExpr) {
395     SizeExprCache[Ty] = SizeExpr;
396   }
397 
398   /// Module debugging: Support for building PCMs.
399   /// @{
400   /// Set the main CU's DwoId field to \p Signature.
401   void setDwoId(uint64_t Signature);
402 
403   /// When generating debug information for a clang module or
404   /// precompiled header, this module map will be used to determine
405   /// the module of origin of each Decl.
406   void setModuleMap(ModuleMap &MMap) { ClangModuleMap = &MMap; }
407 
408   /// When generating debug information for a clang module or
409   /// precompiled header, this module map will be used to determine
410   /// the module of origin of each Decl.
411   void setPCHDescriptor(ASTSourceDescriptor PCH) { PCHDescriptor = PCH; }
412   /// @}
413 
414   /// Update the current source location. If \arg loc is invalid it is
415   /// ignored.
416   void setLocation(SourceLocation Loc);
417 
418   /// Return the current source location. This does not necessarily correspond
419   /// to the IRBuilder's current DebugLoc.
420   SourceLocation getLocation() const { return CurLoc; }
421 
422   /// Update the current inline scope. All subsequent calls to \p EmitLocation
423   /// will create a location with this inlinedAt field.
424   void setInlinedAt(llvm::MDNode *InlinedAt) { CurInlinedAt = InlinedAt; }
425 
426   /// \return the current inline scope.
427   llvm::MDNode *getInlinedAt() const { return CurInlinedAt; }
428 
429   // Converts a SourceLocation to a DebugLoc
430   llvm::DebugLoc SourceLocToDebugLoc(SourceLocation Loc);
431 
432   /// Emit metadata to indicate a change in line/column information in
433   /// the source file. If the location is invalid, the previous
434   /// location will be reused.
435   void EmitLocation(CGBuilderTy &Builder, SourceLocation Loc);
436 
437   QualType getFunctionType(const FunctionDecl *FD, QualType RetTy,
438                            const SmallVectorImpl<const VarDecl *> &Args);
439 
440   /// Emit a call to llvm.dbg.function.start to indicate
441   /// start of a new function.
442   /// \param Loc       The location of the function header.
443   /// \param ScopeLoc  The location of the function body.
444   void emitFunctionStart(GlobalDecl GD, SourceLocation Loc,
445                          SourceLocation ScopeLoc, QualType FnType,
446                          llvm::Function *Fn, bool CurFnIsThunk);
447 
448   /// Start a new scope for an inlined function.
449   void EmitInlineFunctionStart(CGBuilderTy &Builder, GlobalDecl GD);
450   /// End an inlined function scope.
451   void EmitInlineFunctionEnd(CGBuilderTy &Builder);
452 
453   /// Emit debug info for a function declaration.
454   /// \p Fn is set only when a declaration for a debug call site gets created.
455   void EmitFunctionDecl(GlobalDecl GD, SourceLocation Loc,
456                         QualType FnType, llvm::Function *Fn = nullptr);
457 
458   /// Emit debug info for an extern function being called.
459   /// This is needed for call site debug info.
460   void EmitFuncDeclForCallSite(llvm::CallBase *CallOrInvoke,
461                                QualType CalleeType,
462                                const FunctionDecl *CalleeDecl);
463 
464   /// Constructs the debug code for exiting a function.
465   void EmitFunctionEnd(CGBuilderTy &Builder, llvm::Function *Fn);
466 
467   /// Emit metadata to indicate the beginning of a new lexical block
468   /// and push the block onto the stack.
469   void EmitLexicalBlockStart(CGBuilderTy &Builder, SourceLocation Loc);
470 
471   /// Emit metadata to indicate the end of a new lexical block and pop
472   /// the current block.
473   void EmitLexicalBlockEnd(CGBuilderTy &Builder, SourceLocation Loc);
474 
475   /// Emit call to \c llvm.dbg.declare for an automatic variable
476   /// declaration.
477   /// Returns a pointer to the DILocalVariable associated with the
478   /// llvm.dbg.declare, or nullptr otherwise.
479   llvm::DILocalVariable *
480   EmitDeclareOfAutoVariable(const VarDecl *Decl, llvm::Value *AI,
481                             CGBuilderTy &Builder,
482                             const bool UsePointerValue = false);
483 
484   /// Emit call to \c llvm.dbg.label for an label.
485   void EmitLabel(const LabelDecl *D, CGBuilderTy &Builder);
486 
487   /// Emit call to \c llvm.dbg.declare for an imported variable
488   /// declaration in a block.
489   void EmitDeclareOfBlockDeclRefVariable(
490       const VarDecl *variable, llvm::Value *storage, CGBuilderTy &Builder,
491       const CGBlockInfo &blockInfo, llvm::Instruction *InsertPoint = nullptr);
492 
493   /// Emit call to \c llvm.dbg.declare for an argument variable
494   /// declaration.
495   llvm::DILocalVariable *EmitDeclareOfArgVariable(const VarDecl *Decl,
496                                                   llvm::Value *AI,
497                                                   unsigned ArgNo,
498                                                   CGBuilderTy &Builder);
499 
500   /// Emit call to \c llvm.dbg.declare for the block-literal argument
501   /// to a block invocation function.
502   void EmitDeclareOfBlockLiteralArgVariable(const CGBlockInfo &block,
503                                             StringRef Name, unsigned ArgNo,
504                                             llvm::AllocaInst *LocalAddr,
505                                             CGBuilderTy &Builder);
506 
507   /// Emit information about a global variable.
508   void EmitGlobalVariable(llvm::GlobalVariable *GV, const VarDecl *Decl);
509 
510   /// Emit a constant global variable's debug info.
511   void EmitGlobalVariable(const ValueDecl *VD, const APValue &Init);
512 
513   /// Emit information about an external variable.
514   void EmitExternalVariable(llvm::GlobalVariable *GV, const VarDecl *Decl);
515 
516   /// Emit C++ using directive.
517   void EmitUsingDirective(const UsingDirectiveDecl &UD);
518 
519   /// Emit the type explicitly casted to.
520   void EmitExplicitCastType(QualType Ty);
521 
522   /// Emit the type even if it might not be used.
523   void EmitAndRetainType(QualType Ty);
524 
525   /// Emit a shadow decl brought in by a using or using-enum
526   void EmitUsingShadowDecl(const UsingShadowDecl &USD);
527 
528   /// Emit C++ using declaration.
529   void EmitUsingDecl(const UsingDecl &UD);
530 
531   /// Emit C++ using-enum declaration.
532   void EmitUsingEnumDecl(const UsingEnumDecl &UD);
533 
534   /// Emit an @import declaration.
535   void EmitImportDecl(const ImportDecl &ID);
536 
537   /// Emit C++ namespace alias.
538   llvm::DIImportedEntity *EmitNamespaceAlias(const NamespaceAliasDecl &NA);
539 
540   /// Emit record type's standalone debug info.
541   llvm::DIType *getOrCreateRecordType(QualType Ty, SourceLocation L);
542 
543   /// Emit an Objective-C interface type standalone debug info.
544   llvm::DIType *getOrCreateInterfaceType(QualType Ty, SourceLocation Loc);
545 
546   /// Emit standalone debug info for a type.
547   llvm::DIType *getOrCreateStandaloneType(QualType Ty, SourceLocation Loc);
548 
549   /// Add heapallocsite metadata for MSAllocator calls.
550   void addHeapAllocSiteMetadata(llvm::CallBase *CallSite, QualType AllocatedTy,
551                                 SourceLocation Loc);
552 
553   void completeType(const EnumDecl *ED);
554   void completeType(const RecordDecl *RD);
555   void completeRequiredType(const RecordDecl *RD);
556   void completeClassData(const RecordDecl *RD);
557   void completeClass(const RecordDecl *RD);
558 
559   void completeTemplateDefinition(const ClassTemplateSpecializationDecl &SD);
560   void completeUnusedClass(const CXXRecordDecl &D);
561 
562   /// Create debug info for a macro defined by a #define directive or a macro
563   /// undefined by a #undef directive.
564   llvm::DIMacro *CreateMacro(llvm::DIMacroFile *Parent, unsigned MType,
565                              SourceLocation LineLoc, StringRef Name,
566                              StringRef Value);
567 
568   /// Create debug info for a file referenced by an #include directive.
569   llvm::DIMacroFile *CreateTempMacroFile(llvm::DIMacroFile *Parent,
570                                          SourceLocation LineLoc,
571                                          SourceLocation FileLoc);
572 
573   Param2DILocTy &getParamDbgMappings() { return ParamDbgMappings; }
574   ParamDecl2StmtTy &getCoroutineParameterMappings() {
575     return CoroutineParameterMappings;
576   }
577 
578 private:
579   /// Emit call to llvm.dbg.declare for a variable declaration.
580   /// Returns a pointer to the DILocalVariable associated with the
581   /// llvm.dbg.declare, or nullptr otherwise.
582   llvm::DILocalVariable *EmitDeclare(const VarDecl *decl, llvm::Value *AI,
583                                      llvm::Optional<unsigned> ArgNo,
584                                      CGBuilderTy &Builder,
585                                      const bool UsePointerValue = false);
586 
587   struct BlockByRefType {
588     /// The wrapper struct used inside the __block_literal struct.
589     llvm::DIType *BlockByRefWrapper;
590     /// The type as it appears in the source code.
591     llvm::DIType *WrappedType;
592   };
593 
594   std::string GetName(const Decl*, bool Qualified = false) const;
595 
596   /// Build up structure info for the byref.  See \a BuildByRefType.
597   BlockByRefType EmitTypeForVarWithBlocksAttr(const VarDecl *VD,
598                                               uint64_t *OffSet);
599 
600   /// Get context info for the DeclContext of \p Decl.
601   llvm::DIScope *getDeclContextDescriptor(const Decl *D);
602   /// Get context info for a given DeclContext \p Decl.
603   llvm::DIScope *getContextDescriptor(const Decl *Context,
604                                       llvm::DIScope *Default);
605 
606   llvm::DIScope *getCurrentContextDescriptor(const Decl *Decl);
607 
608   /// Create a forward decl for a RecordType in a given context.
609   llvm::DICompositeType *getOrCreateRecordFwdDecl(const RecordType *,
610                                                   llvm::DIScope *);
611 
612   /// Return current directory name.
613   StringRef getCurrentDirname();
614 
615   /// Create new compile unit.
616   void CreateCompileUnit();
617 
618   /// Compute the file checksum debug info for input file ID.
619   Optional<llvm::DIFile::ChecksumKind>
620   computeChecksum(FileID FID, SmallString<32> &Checksum) const;
621 
622   /// Get the source of the given file ID.
623   Optional<StringRef> getSource(const SourceManager &SM, FileID FID);
624 
625   /// Convenience function to get the file debug info descriptor for the input
626   /// location.
627   llvm::DIFile *getOrCreateFile(SourceLocation Loc);
628 
629   /// Create a file debug info descriptor for a source file.
630   llvm::DIFile *
631   createFile(StringRef FileName,
632              Optional<llvm::DIFile::ChecksumInfo<StringRef>> CSInfo,
633              Optional<StringRef> Source);
634 
635   /// Get the type from the cache or create a new type if necessary.
636   llvm::DIType *getOrCreateType(QualType Ty, llvm::DIFile *Fg,
637                                 TypeLoc TL = TypeLoc());
638 
639   /// Get a reference to a clang module.  If \p CreateSkeletonCU is true,
640   /// this also creates a split dwarf skeleton compile unit.
641   llvm::DIModule *getOrCreateModuleRef(ASTSourceDescriptor Mod,
642                                        bool CreateSkeletonCU);
643 
644   /// DebugTypeExtRefs: If \p D originated in a clang module, return it.
645   llvm::DIModule *getParentModuleOrNull(const Decl *D);
646 
647   /// Get the type from the cache or create a new partial type if
648   /// necessary.
649   llvm::DICompositeType *getOrCreateLimitedType(const RecordType *Ty);
650 
651   /// Create type metadata for a source language type.
652   llvm::DIType *CreateTypeNode(QualType Ty, llvm::DIFile *Fg,
653                                TypeLoc TL = TypeLoc());
654 
655   /// Create new member and increase Offset by FType's size.
656   llvm::DIType *CreateMemberType(llvm::DIFile *Unit, QualType FType,
657                                  StringRef Name, uint64_t *Offset);
658 
659   /// Retrieve the DIDescriptor, if any, for the canonical form of this
660   /// declaration.
661   llvm::DINode *getDeclarationOrDefinition(const Decl *D);
662 
663   /// \return debug info descriptor to describe method
664   /// declaration for the given method definition.
665   llvm::DISubprogram *getFunctionDeclaration(const Decl *D);
666 
667   /// \return          debug info descriptor to the describe method declaration
668   ///                  for the given method definition.
669   /// \param FnType    For Objective-C methods, their type.
670   /// \param LineNo    The declaration's line number.
671   /// \param Flags     The DIFlags for the method declaration.
672   /// \param SPFlags   The subprogram-spcific flags for the method declaration.
673   llvm::DISubprogram *
674   getObjCMethodDeclaration(const Decl *D, llvm::DISubroutineType *FnType,
675                            unsigned LineNo, llvm::DINode::DIFlags Flags,
676                            llvm::DISubprogram::DISPFlags SPFlags);
677 
678   /// \return debug info descriptor to describe in-class static data
679   /// member declaration for the given out-of-class definition.  If D
680   /// is an out-of-class definition of a static data member of a
681   /// class, find its corresponding in-class declaration.
682   llvm::DIDerivedType *
683   getOrCreateStaticDataMemberDeclarationOrNull(const VarDecl *D);
684 
685   /// Helper that either creates a forward declaration or a stub.
686   llvm::DISubprogram *getFunctionFwdDeclOrStub(GlobalDecl GD, bool Stub);
687 
688   /// Create a subprogram describing the forward declaration
689   /// represented in the given FunctionDecl wrapped in a GlobalDecl.
690   llvm::DISubprogram *getFunctionForwardDeclaration(GlobalDecl GD);
691 
692   /// Create a DISubprogram describing the function
693   /// represented in the given FunctionDecl wrapped in a GlobalDecl.
694   llvm::DISubprogram *getFunctionStub(GlobalDecl GD);
695 
696   /// Create a global variable describing the forward declaration
697   /// represented in the given VarDecl.
698   llvm::DIGlobalVariable *
699   getGlobalVariableForwardDeclaration(const VarDecl *VD);
700 
701   /// Return a global variable that represents one of the collection of global
702   /// variables created for an anonmyous union.
703   ///
704   /// Recursively collect all of the member fields of a global
705   /// anonymous decl and create static variables for them. The first
706   /// time this is called it needs to be on a union and then from
707   /// there we can have additional unnamed fields.
708   llvm::DIGlobalVariableExpression *
709   CollectAnonRecordDecls(const RecordDecl *RD, llvm::DIFile *Unit,
710                          unsigned LineNo, StringRef LinkageName,
711                          llvm::GlobalVariable *Var, llvm::DIScope *DContext);
712 
713 
714   /// Return flags which enable debug info emission for call sites, provided
715   /// that it is supported and enabled.
716   llvm::DINode::DIFlags getCallSiteRelatedAttrs() const;
717 
718   /// Get the printing policy for producing names for debug info.
719   PrintingPolicy getPrintingPolicy() const;
720 
721   /// Get function name for the given FunctionDecl. If the name is
722   /// constructed on demand (e.g., C++ destructor) then the name is
723   /// stored on the side.
724   StringRef getFunctionName(const FunctionDecl *FD);
725 
726   /// Returns the unmangled name of an Objective-C method.
727   /// This is the display name for the debugging info.
728   StringRef getObjCMethodName(const ObjCMethodDecl *FD);
729 
730   /// Return selector name. This is used for debugging
731   /// info.
732   StringRef getSelectorName(Selector S);
733 
734   /// Get class name including template argument list.
735   StringRef getClassName(const RecordDecl *RD);
736 
737   /// Get the vtable name for the given class.
738   StringRef getVTableName(const CXXRecordDecl *Decl);
739 
740   /// Get the name to use in the debug info for a dynamic initializer or atexit
741   /// stub function.
742   StringRef getDynamicInitializerName(const VarDecl *VD,
743                                       DynamicInitKind StubKind,
744                                       llvm::Function *InitFn);
745 
746   /// Get line number for the location. If location is invalid
747   /// then use current location.
748   unsigned getLineNumber(SourceLocation Loc);
749 
750   /// Get column number for the location. If location is
751   /// invalid then use current location.
752   /// \param Force  Assume DebugColumnInfo option is true.
753   unsigned getColumnNumber(SourceLocation Loc, bool Force = false);
754 
755   /// Collect various properties of a FunctionDecl.
756   /// \param GD  A GlobalDecl whose getDecl() must return a FunctionDecl.
757   void collectFunctionDeclProps(GlobalDecl GD, llvm::DIFile *Unit,
758                                 StringRef &Name, StringRef &LinkageName,
759                                 llvm::DIScope *&FDContext,
760                                 llvm::DINodeArray &TParamsArray,
761                                 llvm::DINode::DIFlags &Flags);
762 
763   /// Collect various properties of a VarDecl.
764   void collectVarDeclProps(const VarDecl *VD, llvm::DIFile *&Unit,
765                            unsigned &LineNo, QualType &T, StringRef &Name,
766                            StringRef &LinkageName,
767                            llvm::MDTuple *&TemplateParameters,
768                            llvm::DIScope *&VDContext);
769 
770   /// Allocate a copy of \p A using the DebugInfoNames allocator
771   /// and return a reference to it. If multiple arguments are given the strings
772   /// are concatenated.
773   StringRef internString(StringRef A, StringRef B = StringRef()) {
774     char *Data = DebugInfoNames.Allocate<char>(A.size() + B.size());
775     if (!A.empty())
776       std::memcpy(Data, A.data(), A.size());
777     if (!B.empty())
778       std::memcpy(Data + A.size(), B.data(), B.size());
779     return StringRef(Data, A.size() + B.size());
780   }
781 };
782 
783 /// A scoped helper to set the current debug location to the specified
784 /// location or preferred location of the specified Expr.
785 class ApplyDebugLocation {
786 private:
787   void init(SourceLocation TemporaryLocation, bool DefaultToEmpty = false);
788   ApplyDebugLocation(CodeGenFunction &CGF, bool DefaultToEmpty,
789                      SourceLocation TemporaryLocation);
790 
791   llvm::DebugLoc OriginalLocation;
792   CodeGenFunction *CGF;
793 
794 public:
795   /// Set the location to the (valid) TemporaryLocation.
796   ApplyDebugLocation(CodeGenFunction &CGF, SourceLocation TemporaryLocation);
797   ApplyDebugLocation(CodeGenFunction &CGF, const Expr *E);
798   ApplyDebugLocation(CodeGenFunction &CGF, llvm::DebugLoc Loc);
799   ApplyDebugLocation(ApplyDebugLocation &&Other) : CGF(Other.CGF) {
800     Other.CGF = nullptr;
801   }
802   ApplyDebugLocation &operator=(ApplyDebugLocation &&) = default;
803 
804   ~ApplyDebugLocation();
805 
806   /// Apply TemporaryLocation if it is valid. Otherwise switch
807   /// to an artificial debug location that has a valid scope, but no
808   /// line information.
809   ///
810   /// Artificial locations are useful when emitting compiler-generated
811   /// helper functions that have no source location associated with
812   /// them. The DWARF specification allows the compiler to use the
813   /// special line number 0 to indicate code that can not be
814   /// attributed to any source location. Note that passing an empty
815   /// SourceLocation to CGDebugInfo::setLocation() will result in the
816   /// last valid location being reused.
817   static ApplyDebugLocation CreateArtificial(CodeGenFunction &CGF) {
818     return ApplyDebugLocation(CGF, false, SourceLocation());
819   }
820   /// Apply TemporaryLocation if it is valid. Otherwise switch
821   /// to an artificial debug location that has a valid scope, but no
822   /// line information.
823   static ApplyDebugLocation
824   CreateDefaultArtificial(CodeGenFunction &CGF,
825                           SourceLocation TemporaryLocation) {
826     return ApplyDebugLocation(CGF, false, TemporaryLocation);
827   }
828 
829   /// Set the IRBuilder to not attach debug locations.  Note that
830   /// passing an empty SourceLocation to \a CGDebugInfo::setLocation()
831   /// will result in the last valid location being reused.  Note that
832   /// all instructions that do not have a location at the beginning of
833   /// a function are counted towards to function prologue.
834   static ApplyDebugLocation CreateEmpty(CodeGenFunction &CGF) {
835     return ApplyDebugLocation(CGF, true, SourceLocation());
836   }
837 };
838 
839 /// A scoped helper to set the current debug location to an inlined location.
840 class ApplyInlineDebugLocation {
841   SourceLocation SavedLocation;
842   CodeGenFunction *CGF;
843 
844 public:
845   /// Set up the CodeGenFunction's DebugInfo to produce inline locations for the
846   /// function \p InlinedFn. The current debug location becomes the inlined call
847   /// site of the inlined function.
848   ApplyInlineDebugLocation(CodeGenFunction &CGF, GlobalDecl InlinedFn);
849   /// Restore everything back to the original state.
850   ~ApplyInlineDebugLocation();
851 };
852 
853 } // namespace CodeGen
854 } // namespace clang
855 
856 #endif // LLVM_CLANG_LIB_CODEGEN_CGDEBUGINFO_H
857