xref: /freebsd/contrib/llvm-project/clang/lib/CodeGen/CGDebugInfo.h (revision 1323ec571215a77ddd21294f0871979d5ad6b992)
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   llvm::DIType *CreateType(const TypedefType *Ty, llvm::DIFile *Fg);
183   llvm::DIType *CreateType(const TemplateSpecializationType *Ty,
184                            llvm::DIFile *Fg);
185   llvm::DIType *CreateType(const ObjCObjectPointerType *Ty, llvm::DIFile *F);
186   llvm::DIType *CreateType(const PointerType *Ty, llvm::DIFile *F);
187   llvm::DIType *CreateType(const BlockPointerType *Ty, llvm::DIFile *F);
188   llvm::DIType *CreateType(const FunctionType *Ty, llvm::DIFile *F);
189   /// Get structure or union type.
190   llvm::DIType *CreateType(const RecordType *Tyg);
191   llvm::DIType *CreateTypeDefinition(const RecordType *Ty);
192   llvm::DICompositeType *CreateLimitedType(const RecordType *Ty);
193   void CollectContainingType(const CXXRecordDecl *RD,
194                              llvm::DICompositeType *CT);
195   /// Get Objective-C interface type.
196   llvm::DIType *CreateType(const ObjCInterfaceType *Ty, llvm::DIFile *F);
197   llvm::DIType *CreateTypeDefinition(const ObjCInterfaceType *Ty,
198                                      llvm::DIFile *F);
199   /// Get Objective-C object type.
200   llvm::DIType *CreateType(const ObjCObjectType *Ty, llvm::DIFile *F);
201   llvm::DIType *CreateType(const ObjCTypeParamType *Ty, llvm::DIFile *Unit);
202 
203   llvm::DIType *CreateType(const VectorType *Ty, llvm::DIFile *F);
204   llvm::DIType *CreateType(const ConstantMatrixType *Ty, llvm::DIFile *F);
205   llvm::DIType *CreateType(const ArrayType *Ty, llvm::DIFile *F);
206   llvm::DIType *CreateType(const LValueReferenceType *Ty, llvm::DIFile *F);
207   llvm::DIType *CreateType(const RValueReferenceType *Ty, llvm::DIFile *Unit);
208   llvm::DIType *CreateType(const MemberPointerType *Ty, llvm::DIFile *F);
209   llvm::DIType *CreateType(const AtomicType *Ty, llvm::DIFile *F);
210   llvm::DIType *CreateType(const PipeType *Ty, llvm::DIFile *F);
211   /// Get enumeration type.
212   llvm::DIType *CreateEnumType(const EnumType *Ty);
213   llvm::DIType *CreateTypeDefinition(const EnumType *Ty);
214   /// Look up the completed type for a self pointer in the TypeCache and
215   /// create a copy of it with the ObjectPointer and Artificial flags
216   /// set. If the type is not cached, a new one is created. This should
217   /// never happen though, since creating a type for the implicit self
218   /// argument implies that we already parsed the interface definition
219   /// and the ivar declarations in the implementation.
220   llvm::DIType *CreateSelfType(const QualType &QualTy, llvm::DIType *Ty);
221   /// @}
222 
223   /// Get the type from the cache or return null type if it doesn't
224   /// exist.
225   llvm::DIType *getTypeOrNull(const QualType);
226   /// Return the debug type for a C++ method.
227   /// \arg CXXMethodDecl is of FunctionType. This function type is
228   /// not updated to include implicit \c this pointer. Use this routine
229   /// to get a method type which includes \c this pointer.
230   llvm::DISubroutineType *getOrCreateMethodType(const CXXMethodDecl *Method,
231                                                 llvm::DIFile *F, bool decl);
232   llvm::DISubroutineType *
233   getOrCreateInstanceMethodType(QualType ThisPtr, const FunctionProtoType *Func,
234                                 llvm::DIFile *Unit, bool decl);
235   llvm::DISubroutineType *
236   getOrCreateFunctionType(const Decl *D, QualType FnType, llvm::DIFile *F);
237   /// \return debug info descriptor for vtable.
238   llvm::DIType *getOrCreateVTablePtrType(llvm::DIFile *F);
239 
240   /// \return namespace descriptor for the given namespace decl.
241   llvm::DINamespace *getOrCreateNamespace(const NamespaceDecl *N);
242   llvm::DIType *CreatePointerLikeType(llvm::dwarf::Tag Tag, const Type *Ty,
243                                       QualType PointeeTy, llvm::DIFile *F);
244   llvm::DIType *getOrCreateStructPtrType(StringRef Name, llvm::DIType *&Cache);
245 
246   /// A helper function to create a subprogram for a single member
247   /// function GlobalDecl.
248   llvm::DISubprogram *CreateCXXMemberFunction(const CXXMethodDecl *Method,
249                                               llvm::DIFile *F,
250                                               llvm::DIType *RecordTy);
251 
252   /// A helper function to collect debug info for C++ member
253   /// functions. This is used while creating debug info entry for a
254   /// Record.
255   void CollectCXXMemberFunctions(const CXXRecordDecl *Decl, llvm::DIFile *F,
256                                  SmallVectorImpl<llvm::Metadata *> &E,
257                                  llvm::DIType *T);
258 
259   /// A helper function to collect debug info for C++ base
260   /// classes. This is used while creating debug info entry for a
261   /// Record.
262   void CollectCXXBases(const CXXRecordDecl *Decl, llvm::DIFile *F,
263                        SmallVectorImpl<llvm::Metadata *> &EltTys,
264                        llvm::DIType *RecordTy);
265 
266   /// Helper function for CollectCXXBases.
267   /// Adds debug info entries for types in Bases that are not in SeenTypes.
268   void CollectCXXBasesAux(
269       const CXXRecordDecl *RD, llvm::DIFile *Unit,
270       SmallVectorImpl<llvm::Metadata *> &EltTys, llvm::DIType *RecordTy,
271       const CXXRecordDecl::base_class_const_range &Bases,
272       llvm::DenseSet<CanonicalDeclPtr<const CXXRecordDecl>> &SeenTypes,
273       llvm::DINode::DIFlags StartingFlags);
274 
275   /// A helper function to collect template parameters.
276   llvm::DINodeArray CollectTemplateParams(const TemplateParameterList *TPList,
277                                           ArrayRef<TemplateArgument> TAList,
278                                           llvm::DIFile *Unit);
279   /// A helper function to collect debug info for function template
280   /// parameters.
281   llvm::DINodeArray CollectFunctionTemplateParams(const FunctionDecl *FD,
282                                                   llvm::DIFile *Unit);
283 
284   /// A helper function to collect debug info for function template
285   /// parameters.
286   llvm::DINodeArray CollectVarTemplateParams(const VarDecl *VD,
287                                              llvm::DIFile *Unit);
288 
289   /// A helper function to collect debug info for template
290   /// parameters.
291   llvm::DINodeArray
292   CollectCXXTemplateParams(const ClassTemplateSpecializationDecl *TS,
293                            llvm::DIFile *F);
294 
295   llvm::DIType *createFieldType(StringRef name, QualType type,
296                                 SourceLocation loc, AccessSpecifier AS,
297                                 uint64_t offsetInBits, uint32_t AlignInBits,
298                                 llvm::DIFile *tunit, llvm::DIScope *scope,
299                                 const RecordDecl *RD = nullptr);
300 
301   llvm::DIType *createFieldType(StringRef name, QualType type,
302                                 SourceLocation loc, AccessSpecifier AS,
303                                 uint64_t offsetInBits, llvm::DIFile *tunit,
304                                 llvm::DIScope *scope,
305                                 const RecordDecl *RD = nullptr) {
306     return createFieldType(name, type, loc, AS, offsetInBits, 0, tunit, scope,
307                            RD);
308   }
309 
310   /// Create new bit field member.
311   llvm::DIType *createBitFieldType(const FieldDecl *BitFieldDecl,
312                                    llvm::DIScope *RecordTy,
313                                    const RecordDecl *RD);
314 
315   /// Helpers for collecting fields of a record.
316   /// @{
317   void CollectRecordLambdaFields(const CXXRecordDecl *CXXDecl,
318                                  SmallVectorImpl<llvm::Metadata *> &E,
319                                  llvm::DIType *RecordTy);
320   llvm::DIDerivedType *CreateRecordStaticField(const VarDecl *Var,
321                                                llvm::DIType *RecordTy,
322                                                const RecordDecl *RD);
323   void CollectRecordNormalField(const FieldDecl *Field, uint64_t OffsetInBits,
324                                 llvm::DIFile *F,
325                                 SmallVectorImpl<llvm::Metadata *> &E,
326                                 llvm::DIType *RecordTy, const RecordDecl *RD);
327   void CollectRecordNestedType(const TypeDecl *RD,
328                                SmallVectorImpl<llvm::Metadata *> &E);
329   void CollectRecordFields(const RecordDecl *Decl, llvm::DIFile *F,
330                            SmallVectorImpl<llvm::Metadata *> &E,
331                            llvm::DICompositeType *RecordTy);
332 
333   /// If the C++ class has vtable info then insert appropriate debug
334   /// info entry in EltTys vector.
335   void CollectVTableInfo(const CXXRecordDecl *Decl, llvm::DIFile *F,
336                          SmallVectorImpl<llvm::Metadata *> &EltTys);
337   /// @}
338 
339   /// Create a new lexical block node and push it on the stack.
340   void CreateLexicalBlock(SourceLocation Loc);
341 
342   /// If target-specific LLVM \p AddressSpace directly maps to target-specific
343   /// DWARF address space, appends extended dereferencing mechanism to complex
344   /// expression \p Expr. Otherwise, does nothing.
345   ///
346   /// Extended dereferencing mechanism is has the following format:
347   ///     DW_OP_constu <DWARF Address Space> DW_OP_swap DW_OP_xderef
348   void AppendAddressSpaceXDeref(unsigned AddressSpace,
349                                 SmallVectorImpl<int64_t> &Expr) const;
350 
351   /// A helper function to collect debug info for the default elements of a
352   /// block.
353   ///
354   /// \returns The next available field offset after the default elements.
355   uint64_t collectDefaultElementTypesForBlockPointer(
356       const BlockPointerType *Ty, llvm::DIFile *Unit,
357       llvm::DIDerivedType *DescTy, unsigned LineNo,
358       SmallVectorImpl<llvm::Metadata *> &EltTys);
359 
360   /// A helper function to collect debug info for the default fields of a
361   /// block.
362   void collectDefaultFieldsForBlockLiteralDeclare(
363       const CGBlockInfo &Block, const ASTContext &Context, SourceLocation Loc,
364       const llvm::StructLayout &BlockLayout, llvm::DIFile *Unit,
365       SmallVectorImpl<llvm::Metadata *> &Fields);
366 
367 public:
368   CGDebugInfo(CodeGenModule &CGM);
369   ~CGDebugInfo();
370 
371   void finalize();
372 
373   /// Remap a given path with the current debug prefix map
374   std::string remapDIPath(StringRef) const;
375 
376   /// Register VLA size expression debug node with the qualified type.
377   void registerVLASizeExpression(QualType Ty, llvm::Metadata *SizeExpr) {
378     SizeExprCache[Ty] = SizeExpr;
379   }
380 
381   /// Module debugging: Support for building PCMs.
382   /// @{
383   /// Set the main CU's DwoId field to \p Signature.
384   void setDwoId(uint64_t Signature);
385 
386   /// When generating debug information for a clang module or
387   /// precompiled header, this module map will be used to determine
388   /// the module of origin of each Decl.
389   void setModuleMap(ModuleMap &MMap) { ClangModuleMap = &MMap; }
390 
391   /// When generating debug information for a clang module or
392   /// precompiled header, this module map will be used to determine
393   /// the module of origin of each Decl.
394   void setPCHDescriptor(ASTSourceDescriptor PCH) { PCHDescriptor = PCH; }
395   /// @}
396 
397   /// Update the current source location. If \arg loc is invalid it is
398   /// ignored.
399   void setLocation(SourceLocation Loc);
400 
401   /// Return the current source location. This does not necessarily correspond
402   /// to the IRBuilder's current DebugLoc.
403   SourceLocation getLocation() const { return CurLoc; }
404 
405   /// Update the current inline scope. All subsequent calls to \p EmitLocation
406   /// will create a location with this inlinedAt field.
407   void setInlinedAt(llvm::MDNode *InlinedAt) { CurInlinedAt = InlinedAt; }
408 
409   /// \return the current inline scope.
410   llvm::MDNode *getInlinedAt() const { return CurInlinedAt; }
411 
412   // Converts a SourceLocation to a DebugLoc
413   llvm::DebugLoc SourceLocToDebugLoc(SourceLocation Loc);
414 
415   /// Emit metadata to indicate a change in line/column information in
416   /// the source file. If the location is invalid, the previous
417   /// location will be reused.
418   void EmitLocation(CGBuilderTy &Builder, SourceLocation Loc);
419 
420   /// Emit a call to llvm.dbg.function.start to indicate
421   /// start of a new function.
422   /// \param Loc       The location of the function header.
423   /// \param ScopeLoc  The location of the function body.
424   void emitFunctionStart(GlobalDecl GD, SourceLocation Loc,
425                          SourceLocation ScopeLoc, QualType FnType,
426                          llvm::Function *Fn, bool CurFnIsThunk);
427 
428   /// Start a new scope for an inlined function.
429   void EmitInlineFunctionStart(CGBuilderTy &Builder, GlobalDecl GD);
430   /// End an inlined function scope.
431   void EmitInlineFunctionEnd(CGBuilderTy &Builder);
432 
433   /// Emit debug info for a function declaration.
434   /// \p Fn is set only when a declaration for a debug call site gets created.
435   void EmitFunctionDecl(GlobalDecl GD, SourceLocation Loc,
436                         QualType FnType, llvm::Function *Fn = nullptr);
437 
438   /// Emit debug info for an extern function being called.
439   /// This is needed for call site debug info.
440   void EmitFuncDeclForCallSite(llvm::CallBase *CallOrInvoke,
441                                QualType CalleeType,
442                                const FunctionDecl *CalleeDecl);
443 
444   /// Constructs the debug code for exiting a function.
445   void EmitFunctionEnd(CGBuilderTy &Builder, llvm::Function *Fn);
446 
447   /// Emit metadata to indicate the beginning of a new lexical block
448   /// and push the block onto the stack.
449   void EmitLexicalBlockStart(CGBuilderTy &Builder, SourceLocation Loc);
450 
451   /// Emit metadata to indicate the end of a new lexical block and pop
452   /// the current block.
453   void EmitLexicalBlockEnd(CGBuilderTy &Builder, SourceLocation Loc);
454 
455   /// Emit call to \c llvm.dbg.declare for an automatic variable
456   /// declaration.
457   /// Returns a pointer to the DILocalVariable associated with the
458   /// llvm.dbg.declare, or nullptr otherwise.
459   llvm::DILocalVariable *
460   EmitDeclareOfAutoVariable(const VarDecl *Decl, llvm::Value *AI,
461                             CGBuilderTy &Builder,
462                             const bool UsePointerValue = false);
463 
464   /// Emit call to \c llvm.dbg.label for an label.
465   void EmitLabel(const LabelDecl *D, CGBuilderTy &Builder);
466 
467   /// Emit call to \c llvm.dbg.declare for an imported variable
468   /// declaration in a block.
469   void EmitDeclareOfBlockDeclRefVariable(
470       const VarDecl *variable, llvm::Value *storage, CGBuilderTy &Builder,
471       const CGBlockInfo &blockInfo, llvm::Instruction *InsertPoint = nullptr);
472 
473   /// Emit call to \c llvm.dbg.declare for an argument variable
474   /// declaration.
475   llvm::DILocalVariable *EmitDeclareOfArgVariable(const VarDecl *Decl,
476                                                   llvm::Value *AI,
477                                                   unsigned ArgNo,
478                                                   CGBuilderTy &Builder);
479 
480   /// Emit call to \c llvm.dbg.declare for the block-literal argument
481   /// to a block invocation function.
482   void EmitDeclareOfBlockLiteralArgVariable(const CGBlockInfo &block,
483                                             StringRef Name, unsigned ArgNo,
484                                             llvm::AllocaInst *LocalAddr,
485                                             CGBuilderTy &Builder);
486 
487   /// Emit information about a global variable.
488   void EmitGlobalVariable(llvm::GlobalVariable *GV, const VarDecl *Decl);
489 
490   /// Emit a constant global variable's debug info.
491   void EmitGlobalVariable(const ValueDecl *VD, const APValue &Init);
492 
493   /// Emit information about an external variable.
494   void EmitExternalVariable(llvm::GlobalVariable *GV, const VarDecl *Decl);
495 
496   /// Emit C++ using directive.
497   void EmitUsingDirective(const UsingDirectiveDecl &UD);
498 
499   /// Emit the type explicitly casted to.
500   void EmitExplicitCastType(QualType Ty);
501 
502   /// Emit the type even if it might not be used.
503   void EmitAndRetainType(QualType Ty);
504 
505   /// Emit a shadow decl brought in by a using or using-enum
506   void EmitUsingShadowDecl(const UsingShadowDecl &USD);
507 
508   /// Emit C++ using declaration.
509   void EmitUsingDecl(const UsingDecl &UD);
510 
511   /// Emit C++ using-enum declaration.
512   void EmitUsingEnumDecl(const UsingEnumDecl &UD);
513 
514   /// Emit an @import declaration.
515   void EmitImportDecl(const ImportDecl &ID);
516 
517   /// Emit C++ namespace alias.
518   llvm::DIImportedEntity *EmitNamespaceAlias(const NamespaceAliasDecl &NA);
519 
520   /// Emit record type's standalone debug info.
521   llvm::DIType *getOrCreateRecordType(QualType Ty, SourceLocation L);
522 
523   /// Emit an Objective-C interface type standalone debug info.
524   llvm::DIType *getOrCreateInterfaceType(QualType Ty, SourceLocation Loc);
525 
526   /// Emit standalone debug info for a type.
527   llvm::DIType *getOrCreateStandaloneType(QualType Ty, SourceLocation Loc);
528 
529   /// Add heapallocsite metadata for MSAllocator calls.
530   void addHeapAllocSiteMetadata(llvm::CallBase *CallSite, QualType AllocatedTy,
531                                 SourceLocation Loc);
532 
533   void completeType(const EnumDecl *ED);
534   void completeType(const RecordDecl *RD);
535   void completeRequiredType(const RecordDecl *RD);
536   void completeClassData(const RecordDecl *RD);
537   void completeClass(const RecordDecl *RD);
538 
539   void completeTemplateDefinition(const ClassTemplateSpecializationDecl &SD);
540   void completeUnusedClass(const CXXRecordDecl &D);
541 
542   /// Create debug info for a macro defined by a #define directive or a macro
543   /// undefined by a #undef directive.
544   llvm::DIMacro *CreateMacro(llvm::DIMacroFile *Parent, unsigned MType,
545                              SourceLocation LineLoc, StringRef Name,
546                              StringRef Value);
547 
548   /// Create debug info for a file referenced by an #include directive.
549   llvm::DIMacroFile *CreateTempMacroFile(llvm::DIMacroFile *Parent,
550                                          SourceLocation LineLoc,
551                                          SourceLocation FileLoc);
552 
553   Param2DILocTy &getParamDbgMappings() { return ParamDbgMappings; }
554   ParamDecl2StmtTy &getCoroutineParameterMappings() {
555     return CoroutineParameterMappings;
556   }
557 
558 private:
559   /// Emit call to llvm.dbg.declare for a variable declaration.
560   /// Returns a pointer to the DILocalVariable associated with the
561   /// llvm.dbg.declare, or nullptr otherwise.
562   llvm::DILocalVariable *EmitDeclare(const VarDecl *decl, llvm::Value *AI,
563                                      llvm::Optional<unsigned> ArgNo,
564                                      CGBuilderTy &Builder,
565                                      const bool UsePointerValue = false);
566 
567   struct BlockByRefType {
568     /// The wrapper struct used inside the __block_literal struct.
569     llvm::DIType *BlockByRefWrapper;
570     /// The type as it appears in the source code.
571     llvm::DIType *WrappedType;
572   };
573 
574   std::string GetName(const Decl*, bool Qualified = false) const;
575 
576   /// Build up structure info for the byref.  See \a BuildByRefType.
577   BlockByRefType EmitTypeForVarWithBlocksAttr(const VarDecl *VD,
578                                               uint64_t *OffSet);
579 
580   /// Get context info for the DeclContext of \p Decl.
581   llvm::DIScope *getDeclContextDescriptor(const Decl *D);
582   /// Get context info for a given DeclContext \p Decl.
583   llvm::DIScope *getContextDescriptor(const Decl *Context,
584                                       llvm::DIScope *Default);
585 
586   llvm::DIScope *getCurrentContextDescriptor(const Decl *Decl);
587 
588   /// Create a forward decl for a RecordType in a given context.
589   llvm::DICompositeType *getOrCreateRecordFwdDecl(const RecordType *,
590                                                   llvm::DIScope *);
591 
592   /// Return current directory name.
593   StringRef getCurrentDirname();
594 
595   /// Create new compile unit.
596   void CreateCompileUnit();
597 
598   /// Compute the file checksum debug info for input file ID.
599   Optional<llvm::DIFile::ChecksumKind>
600   computeChecksum(FileID FID, SmallString<32> &Checksum) const;
601 
602   /// Get the source of the given file ID.
603   Optional<StringRef> getSource(const SourceManager &SM, FileID FID);
604 
605   /// Convenience function to get the file debug info descriptor for the input
606   /// location.
607   llvm::DIFile *getOrCreateFile(SourceLocation Loc);
608 
609   /// Create a file debug info descriptor for a source file.
610   llvm::DIFile *
611   createFile(StringRef FileName,
612              Optional<llvm::DIFile::ChecksumInfo<StringRef>> CSInfo,
613              Optional<StringRef> Source);
614 
615   /// Get the type from the cache or create a new type if necessary.
616   llvm::DIType *getOrCreateType(QualType Ty, llvm::DIFile *Fg);
617 
618   /// Get a reference to a clang module.  If \p CreateSkeletonCU is true,
619   /// this also creates a split dwarf skeleton compile unit.
620   llvm::DIModule *getOrCreateModuleRef(ASTSourceDescriptor Mod,
621                                        bool CreateSkeletonCU);
622 
623   /// DebugTypeExtRefs: If \p D originated in a clang module, return it.
624   llvm::DIModule *getParentModuleOrNull(const Decl *D);
625 
626   /// Get the type from the cache or create a new partial type if
627   /// necessary.
628   llvm::DICompositeType *getOrCreateLimitedType(const RecordType *Ty);
629 
630   /// Create type metadata for a source language type.
631   llvm::DIType *CreateTypeNode(QualType Ty, llvm::DIFile *Fg);
632 
633   /// Create new member and increase Offset by FType's size.
634   llvm::DIType *CreateMemberType(llvm::DIFile *Unit, QualType FType,
635                                  StringRef Name, uint64_t *Offset);
636 
637   /// Retrieve the DIDescriptor, if any, for the canonical form of this
638   /// declaration.
639   llvm::DINode *getDeclarationOrDefinition(const Decl *D);
640 
641   /// \return debug info descriptor to describe method
642   /// declaration for the given method definition.
643   llvm::DISubprogram *getFunctionDeclaration(const Decl *D);
644 
645   /// \return          debug info descriptor to the describe method declaration
646   ///                  for the given method definition.
647   /// \param FnType    For Objective-C methods, their type.
648   /// \param LineNo    The declaration's line number.
649   /// \param Flags     The DIFlags for the method declaration.
650   /// \param SPFlags   The subprogram-spcific flags for the method declaration.
651   llvm::DISubprogram *
652   getObjCMethodDeclaration(const Decl *D, llvm::DISubroutineType *FnType,
653                            unsigned LineNo, llvm::DINode::DIFlags Flags,
654                            llvm::DISubprogram::DISPFlags SPFlags);
655 
656   /// \return debug info descriptor to describe in-class static data
657   /// member declaration for the given out-of-class definition.  If D
658   /// is an out-of-class definition of a static data member of a
659   /// class, find its corresponding in-class declaration.
660   llvm::DIDerivedType *
661   getOrCreateStaticDataMemberDeclarationOrNull(const VarDecl *D);
662 
663   /// Helper that either creates a forward declaration or a stub.
664   llvm::DISubprogram *getFunctionFwdDeclOrStub(GlobalDecl GD, bool Stub);
665 
666   /// Create a subprogram describing the forward declaration
667   /// represented in the given FunctionDecl wrapped in a GlobalDecl.
668   llvm::DISubprogram *getFunctionForwardDeclaration(GlobalDecl GD);
669 
670   /// Create a DISubprogram describing the function
671   /// represented in the given FunctionDecl wrapped in a GlobalDecl.
672   llvm::DISubprogram *getFunctionStub(GlobalDecl GD);
673 
674   /// Create a global variable describing the forward declaration
675   /// represented in the given VarDecl.
676   llvm::DIGlobalVariable *
677   getGlobalVariableForwardDeclaration(const VarDecl *VD);
678 
679   /// Return a global variable that represents one of the collection of global
680   /// variables created for an anonmyous union.
681   ///
682   /// Recursively collect all of the member fields of a global
683   /// anonymous decl and create static variables for them. The first
684   /// time this is called it needs to be on a union and then from
685   /// there we can have additional unnamed fields.
686   llvm::DIGlobalVariableExpression *
687   CollectAnonRecordDecls(const RecordDecl *RD, llvm::DIFile *Unit,
688                          unsigned LineNo, StringRef LinkageName,
689                          llvm::GlobalVariable *Var, llvm::DIScope *DContext);
690 
691 
692   /// Return flags which enable debug info emission for call sites, provided
693   /// that it is supported and enabled.
694   llvm::DINode::DIFlags getCallSiteRelatedAttrs() const;
695 
696   /// Get the printing policy for producing names for debug info.
697   PrintingPolicy getPrintingPolicy() const;
698 
699   /// Get function name for the given FunctionDecl. If the name is
700   /// constructed on demand (e.g., C++ destructor) then the name is
701   /// stored on the side.
702   StringRef getFunctionName(const FunctionDecl *FD);
703 
704   /// Returns the unmangled name of an Objective-C method.
705   /// This is the display name for the debugging info.
706   StringRef getObjCMethodName(const ObjCMethodDecl *FD);
707 
708   /// Return selector name. This is used for debugging
709   /// info.
710   StringRef getSelectorName(Selector S);
711 
712   /// Get class name including template argument list.
713   StringRef getClassName(const RecordDecl *RD);
714 
715   /// Get the vtable name for the given class.
716   StringRef getVTableName(const CXXRecordDecl *Decl);
717 
718   /// Get the name to use in the debug info for a dynamic initializer or atexit
719   /// stub function.
720   StringRef getDynamicInitializerName(const VarDecl *VD,
721                                       DynamicInitKind StubKind,
722                                       llvm::Function *InitFn);
723 
724   /// Get line number for the location. If location is invalid
725   /// then use current location.
726   unsigned getLineNumber(SourceLocation Loc);
727 
728   /// Get column number for the location. If location is
729   /// invalid then use current location.
730   /// \param Force  Assume DebugColumnInfo option is true.
731   unsigned getColumnNumber(SourceLocation Loc, bool Force = false);
732 
733   /// Collect various properties of a FunctionDecl.
734   /// \param GD  A GlobalDecl whose getDecl() must return a FunctionDecl.
735   void collectFunctionDeclProps(GlobalDecl GD, llvm::DIFile *Unit,
736                                 StringRef &Name, StringRef &LinkageName,
737                                 llvm::DIScope *&FDContext,
738                                 llvm::DINodeArray &TParamsArray,
739                                 llvm::DINode::DIFlags &Flags);
740 
741   /// Collect various properties of a VarDecl.
742   void collectVarDeclProps(const VarDecl *VD, llvm::DIFile *&Unit,
743                            unsigned &LineNo, QualType &T, StringRef &Name,
744                            StringRef &LinkageName,
745                            llvm::MDTuple *&TemplateParameters,
746                            llvm::DIScope *&VDContext);
747 
748   /// Allocate a copy of \p A using the DebugInfoNames allocator
749   /// and return a reference to it. If multiple arguments are given the strings
750   /// are concatenated.
751   StringRef internString(StringRef A, StringRef B = StringRef()) {
752     char *Data = DebugInfoNames.Allocate<char>(A.size() + B.size());
753     if (!A.empty())
754       std::memcpy(Data, A.data(), A.size());
755     if (!B.empty())
756       std::memcpy(Data + A.size(), B.data(), B.size());
757     return StringRef(Data, A.size() + B.size());
758   }
759 };
760 
761 /// A scoped helper to set the current debug location to the specified
762 /// location or preferred location of the specified Expr.
763 class ApplyDebugLocation {
764 private:
765   void init(SourceLocation TemporaryLocation, bool DefaultToEmpty = false);
766   ApplyDebugLocation(CodeGenFunction &CGF, bool DefaultToEmpty,
767                      SourceLocation TemporaryLocation);
768 
769   llvm::DebugLoc OriginalLocation;
770   CodeGenFunction *CGF;
771 
772 public:
773   /// Set the location to the (valid) TemporaryLocation.
774   ApplyDebugLocation(CodeGenFunction &CGF, SourceLocation TemporaryLocation);
775   ApplyDebugLocation(CodeGenFunction &CGF, const Expr *E);
776   ApplyDebugLocation(CodeGenFunction &CGF, llvm::DebugLoc Loc);
777   ApplyDebugLocation(ApplyDebugLocation &&Other) : CGF(Other.CGF) {
778     Other.CGF = nullptr;
779   }
780   ApplyDebugLocation &operator=(ApplyDebugLocation &&) = default;
781 
782   ~ApplyDebugLocation();
783 
784   /// Apply TemporaryLocation if it is valid. Otherwise switch
785   /// to an artificial debug location that has a valid scope, but no
786   /// line information.
787   ///
788   /// Artificial locations are useful when emitting compiler-generated
789   /// helper functions that have no source location associated with
790   /// them. The DWARF specification allows the compiler to use the
791   /// special line number 0 to indicate code that can not be
792   /// attributed to any source location. Note that passing an empty
793   /// SourceLocation to CGDebugInfo::setLocation() will result in the
794   /// last valid location being reused.
795   static ApplyDebugLocation CreateArtificial(CodeGenFunction &CGF) {
796     return ApplyDebugLocation(CGF, false, SourceLocation());
797   }
798   /// Apply TemporaryLocation if it is valid. Otherwise switch
799   /// to an artificial debug location that has a valid scope, but no
800   /// line information.
801   static ApplyDebugLocation
802   CreateDefaultArtificial(CodeGenFunction &CGF,
803                           SourceLocation TemporaryLocation) {
804     return ApplyDebugLocation(CGF, false, TemporaryLocation);
805   }
806 
807   /// Set the IRBuilder to not attach debug locations.  Note that
808   /// passing an empty SourceLocation to \a CGDebugInfo::setLocation()
809   /// will result in the last valid location being reused.  Note that
810   /// all instructions that do not have a location at the beginning of
811   /// a function are counted towards to function prologue.
812   static ApplyDebugLocation CreateEmpty(CodeGenFunction &CGF) {
813     return ApplyDebugLocation(CGF, true, SourceLocation());
814   }
815 };
816 
817 /// A scoped helper to set the current debug location to an inlined location.
818 class ApplyInlineDebugLocation {
819   SourceLocation SavedLocation;
820   CodeGenFunction *CGF;
821 
822 public:
823   /// Set up the CodeGenFunction's DebugInfo to produce inline locations for the
824   /// function \p InlinedFn. The current debug location becomes the inlined call
825   /// site of the inlined function.
826   ApplyInlineDebugLocation(CodeGenFunction &CGF, GlobalDecl InlinedFn);
827   /// Restore everything back to the original state.
828   ~ApplyInlineDebugLocation();
829 };
830 
831 } // namespace CodeGen
832 } // namespace clang
833 
834 #endif // LLVM_CLANG_LIB_CODEGEN_CGDEBUGINFO_H
835