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1 //===--- CGDebugInfo.h - DebugInfo for LLVM CodeGen -------------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This is the source-level debug info generator for llvm translation.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_CLANG_LIB_CODEGEN_CGDEBUGINFO_H
15 #define LLVM_CLANG_LIB_CODEGEN_CGDEBUGINFO_H
16 
17 #include "CGBuilder.h"
18 #include "clang/AST/Expr.h"
19 #include "clang/AST/ExternalASTSource.h"
20 #include "clang/AST/Type.h"
21 #include "clang/Basic/SourceLocation.h"
22 #include "clang/Frontend/CodeGenOptions.h"
23 #include "llvm/ADT/DenseMap.h"
24 #include "llvm/ADT/Optional.h"
25 #include "llvm/IR/DIBuilder.h"
26 #include "llvm/IR/DebugInfo.h"
27 #include "llvm/IR/ValueHandle.h"
28 #include "llvm/Support/Allocator.h"
29 
30 namespace llvm {
31 class MDNode;
32 }
33 
34 namespace clang {
35 class CXXMethodDecl;
36 class ClassTemplateSpecializationDecl;
37 class GlobalDecl;
38 class ModuleMap;
39 class ObjCInterfaceDecl;
40 class ObjCIvarDecl;
41 class UsingDecl;
42 class VarDecl;
43 
44 namespace CodeGen {
45 class CodeGenModule;
46 class CodeGenFunction;
47 class CGBlockInfo;
48 
49 /// This class gathers all debug information during compilation and is
50 /// responsible for emitting to llvm globals or pass directly to the
51 /// backend.
52 class CGDebugInfo {
53   friend class ApplyDebugLocation;
54   friend class SaveAndRestoreLocation;
55   CodeGenModule &CGM;
56   const codegenoptions::DebugInfoKind DebugKind;
57   bool DebugTypeExtRefs;
58   llvm::DIBuilder DBuilder;
59   llvm::DICompileUnit *TheCU = nullptr;
60   ModuleMap *ClangModuleMap = nullptr;
61   ExternalASTSource::ASTSourceDescriptor PCHDescriptor;
62   SourceLocation CurLoc;
63   llvm::DIType *VTablePtrType = nullptr;
64   llvm::DIType *ClassTy = nullptr;
65   llvm::DICompositeType *ObjTy = nullptr;
66   llvm::DIType *SelTy = nullptr;
67 #define IMAGE_TYPE(ImgType, Id, SingletonId, Access, Suffix) \
68   llvm::DIType *SingletonId = nullptr;
69 #include "clang/Basic/OpenCLImageTypes.def"
70   llvm::DIType *OCLEventDITy = nullptr;
71   llvm::DIType *OCLClkEventDITy = nullptr;
72   llvm::DIType *OCLQueueDITy = nullptr;
73   llvm::DIType *OCLNDRangeDITy = nullptr;
74   llvm::DIType *OCLReserveIDDITy = nullptr;
75 
76   /// Cache of previously constructed Types.
77   llvm::DenseMap<const void *, llvm::TrackingMDRef> TypeCache;
78 
79   llvm::SmallDenseMap<llvm::StringRef, llvm::StringRef> DebugPrefixMap;
80 
81   struct ObjCInterfaceCacheEntry {
82     const ObjCInterfaceType *Type;
83     llvm::DIType *Decl;
84     llvm::DIFile *Unit;
ObjCInterfaceCacheEntryObjCInterfaceCacheEntry85     ObjCInterfaceCacheEntry(const ObjCInterfaceType *Type, llvm::DIType *Decl,
86                             llvm::DIFile *Unit)
87         : Type(Type), Decl(Decl), Unit(Unit) {}
88   };
89 
90   /// Cache of previously constructed interfaces which may change.
91   llvm::SmallVector<ObjCInterfaceCacheEntry, 32> ObjCInterfaceCache;
92 
93   /// Cache of references to clang modules and precompiled headers.
94   llvm::DenseMap<const Module *, llvm::TrackingMDRef> ModuleCache;
95 
96   /// List of interfaces we want to keep even if orphaned.
97   std::vector<void *> RetainedTypes;
98 
99   /// Cache of forward declared types to RAUW at the end of
100   /// compilation.
101   std::vector<std::pair<const TagType *, llvm::TrackingMDRef>> ReplaceMap;
102 
103   /// Cache of replaceable forward declarations (functions and
104   /// variables) to RAUW at the end of compilation.
105   std::vector<std::pair<const DeclaratorDecl *, llvm::TrackingMDRef>>
106       FwdDeclReplaceMap;
107 
108   /// Keep track of our current nested lexical block.
109   std::vector<llvm::TypedTrackingMDRef<llvm::DIScope>> LexicalBlockStack;
110   llvm::DenseMap<const Decl *, llvm::TrackingMDRef> RegionMap;
111   /// Keep track of LexicalBlockStack counter at the beginning of a
112   /// function. This is used to pop unbalanced regions at the end of a
113   /// function.
114   std::vector<unsigned> FnBeginRegionCount;
115 
116   /// This is a storage for names that are constructed on demand. For
117   /// example, C++ destructors, C++ operators etc..
118   llvm::BumpPtrAllocator DebugInfoNames;
119   StringRef CWDName;
120 
121   llvm::DenseMap<const char *, llvm::TrackingMDRef> DIFileCache;
122   llvm::DenseMap<const FunctionDecl *, llvm::TrackingMDRef> SPCache;
123   /// Cache declarations relevant to DW_TAG_imported_declarations (C++
124   /// using declarations) that aren't covered by other more specific caches.
125   llvm::DenseMap<const Decl *, llvm::TrackingMDRef> DeclCache;
126   llvm::DenseMap<const NamespaceDecl *, llvm::TrackingMDRef> NameSpaceCache;
127   llvm::DenseMap<const NamespaceAliasDecl *, llvm::TrackingMDRef>
128       NamespaceAliasCache;
129   llvm::DenseMap<const Decl *, llvm::TypedTrackingMDRef<llvm::DIDerivedType>>
130       StaticDataMemberCache;
131 
132   /// Helper functions for getOrCreateType.
133   /// @{
134   /// Currently the checksum of an interface includes the number of
135   /// ivars and property accessors.
136   llvm::DIType *CreateType(const BuiltinType *Ty);
137   llvm::DIType *CreateType(const ComplexType *Ty);
138   llvm::DIType *CreateQualifiedType(QualType Ty, llvm::DIFile *Fg);
139   llvm::DIType *CreateType(const TypedefType *Ty, llvm::DIFile *Fg);
140   llvm::DIType *CreateType(const TemplateSpecializationType *Ty,
141                            llvm::DIFile *Fg);
142   llvm::DIType *CreateType(const ObjCObjectPointerType *Ty, llvm::DIFile *F);
143   llvm::DIType *CreateType(const PointerType *Ty, llvm::DIFile *F);
144   llvm::DIType *CreateType(const BlockPointerType *Ty, llvm::DIFile *F);
145   llvm::DIType *CreateType(const FunctionType *Ty, llvm::DIFile *F);
146   /// Get structure or union type.
147   llvm::DIType *CreateType(const RecordType *Tyg);
148   llvm::DIType *CreateTypeDefinition(const RecordType *Ty);
149   llvm::DICompositeType *CreateLimitedType(const RecordType *Ty);
150   void CollectContainingType(const CXXRecordDecl *RD,
151                              llvm::DICompositeType *CT);
152   /// Get Objective-C interface type.
153   llvm::DIType *CreateType(const ObjCInterfaceType *Ty, llvm::DIFile *F);
154   llvm::DIType *CreateTypeDefinition(const ObjCInterfaceType *Ty,
155                                      llvm::DIFile *F);
156   /// Get Objective-C object type.
157   llvm::DIType *CreateType(const ObjCObjectType *Ty, llvm::DIFile *F);
158   llvm::DIType *CreateType(const VectorType *Ty, llvm::DIFile *F);
159   llvm::DIType *CreateType(const ArrayType *Ty, llvm::DIFile *F);
160   llvm::DIType *CreateType(const LValueReferenceType *Ty, llvm::DIFile *F);
161   llvm::DIType *CreateType(const RValueReferenceType *Ty, llvm::DIFile *Unit);
162   llvm::DIType *CreateType(const MemberPointerType *Ty, llvm::DIFile *F);
163   llvm::DIType *CreateType(const AtomicType *Ty, llvm::DIFile *F);
164   llvm::DIType *CreateType(const PipeType *Ty, llvm::DIFile *F);
165   /// Get enumeration type.
166   llvm::DIType *CreateEnumType(const EnumType *Ty);
167   llvm::DIType *CreateTypeDefinition(const EnumType *Ty);
168   /// Look up the completed type for a self pointer in the TypeCache and
169   /// create a copy of it with the ObjectPointer and Artificial flags
170   /// set. If the type is not cached, a new one is created. This should
171   /// never happen though, since creating a type for the implicit self
172   /// argument implies that we already parsed the interface definition
173   /// and the ivar declarations in the implementation.
174   llvm::DIType *CreateSelfType(const QualType &QualTy, llvm::DIType *Ty);
175   /// @}
176 
177   /// Get the type from the cache or return null type if it doesn't
178   /// exist.
179   llvm::DIType *getTypeOrNull(const QualType);
180   /// Return the debug type for a C++ method.
181   /// \arg CXXMethodDecl is of FunctionType. This function type is
182   /// not updated to include implicit \c this pointer. Use this routine
183   /// to get a method type which includes \c this pointer.
184   llvm::DISubroutineType *getOrCreateMethodType(const CXXMethodDecl *Method,
185                                                 llvm::DIFile *F);
186   llvm::DISubroutineType *
187   getOrCreateInstanceMethodType(QualType ThisPtr, const FunctionProtoType *Func,
188                                 llvm::DIFile *Unit);
189   llvm::DISubroutineType *
190   getOrCreateFunctionType(const Decl *D, QualType FnType, llvm::DIFile *F);
191   /// \return debug info descriptor for vtable.
192   llvm::DIType *getOrCreateVTablePtrType(llvm::DIFile *F);
193   /// \return namespace descriptor for the given namespace decl.
194   llvm::DINamespace *getOrCreateNameSpace(const NamespaceDecl *N);
195   llvm::DIType *CreatePointerLikeType(llvm::dwarf::Tag Tag, const Type *Ty,
196                                       QualType PointeeTy, llvm::DIFile *F);
197   llvm::DIType *getOrCreateStructPtrType(StringRef Name, llvm::DIType *&Cache);
198 
199   /// A helper function to create a subprogram for a single member
200   /// function GlobalDecl.
201   llvm::DISubprogram *CreateCXXMemberFunction(const CXXMethodDecl *Method,
202                                               llvm::DIFile *F,
203                                               llvm::DIType *RecordTy);
204 
205   /// A helper function to collect debug info for C++ member
206   /// functions. This is used while creating debug info entry for a
207   /// Record.
208   void CollectCXXMemberFunctions(const CXXRecordDecl *Decl, llvm::DIFile *F,
209                                  SmallVectorImpl<llvm::Metadata *> &E,
210                                  llvm::DIType *T);
211 
212   /// A helper function to collect debug info for C++ base
213   /// classes. This is used while creating debug info entry for a
214   /// Record.
215   void CollectCXXBases(const CXXRecordDecl *Decl, llvm::DIFile *F,
216                        SmallVectorImpl<llvm::Metadata *> &EltTys,
217                        llvm::DIType *RecordTy);
218 
219   /// A helper function to collect template parameters.
220   llvm::DINodeArray CollectTemplateParams(const TemplateParameterList *TPList,
221                                           ArrayRef<TemplateArgument> TAList,
222                                           llvm::DIFile *Unit);
223   /// A helper function to collect debug info for function template
224   /// parameters.
225   llvm::DINodeArray CollectFunctionTemplateParams(const FunctionDecl *FD,
226                                                   llvm::DIFile *Unit);
227 
228   /// A helper function to collect debug info for template
229   /// parameters.
230   llvm::DINodeArray
231   CollectCXXTemplateParams(const ClassTemplateSpecializationDecl *TS,
232                            llvm::DIFile *F);
233 
234   llvm::DIType *createFieldType(StringRef name, QualType type,
235                                 SourceLocation loc, AccessSpecifier AS,
236                                 uint64_t offsetInBits, llvm::DIFile *tunit,
237                                 llvm::DIScope *scope,
238                                 const RecordDecl *RD = nullptr);
239 
240   /// Create new bit field member.
241   llvm::DIType *createBitFieldType(const FieldDecl *BitFieldDecl,
242                                    llvm::DIScope *RecordTy,
243                                    const RecordDecl *RD);
244 
245   /// Helpers for collecting fields of a record.
246   /// @{
247   void CollectRecordLambdaFields(const CXXRecordDecl *CXXDecl,
248                                  SmallVectorImpl<llvm::Metadata *> &E,
249                                  llvm::DIType *RecordTy);
250   llvm::DIDerivedType *CreateRecordStaticField(const VarDecl *Var,
251                                                llvm::DIType *RecordTy,
252                                                const RecordDecl *RD);
253   void CollectRecordNormalField(const FieldDecl *Field, uint64_t OffsetInBits,
254                                 llvm::DIFile *F,
255                                 SmallVectorImpl<llvm::Metadata *> &E,
256                                 llvm::DIType *RecordTy, const RecordDecl *RD);
257   void CollectRecordFields(const RecordDecl *Decl, llvm::DIFile *F,
258                            SmallVectorImpl<llvm::Metadata *> &E,
259                            llvm::DICompositeType *RecordTy);
260 
261   /// If the C++ class has vtable info then insert appropriate debug
262   /// info entry in EltTys vector.
263   void CollectVTableInfo(const CXXRecordDecl *Decl, llvm::DIFile *F,
264                          SmallVectorImpl<llvm::Metadata *> &EltTys);
265   /// @}
266 
267   /// Create a new lexical block node and push it on the stack.
268   void CreateLexicalBlock(SourceLocation Loc);
269 
270 public:
271   CGDebugInfo(CodeGenModule &CGM);
272   ~CGDebugInfo();
273 
274   void finalize();
275 
276   /// Module debugging: Support for building PCMs.
277   /// @{
278   /// Set the main CU's DwoId field to \p Signature.
279   void setDwoId(uint64_t Signature);
280 
281   /// When generating debug information for a clang module or
282   /// precompiled header, this module map will be used to determine
283   /// the module of origin of each Decl.
setModuleMap(ModuleMap & MMap)284   void setModuleMap(ModuleMap &MMap) { ClangModuleMap = &MMap; }
285 
286   /// When generating debug information for a clang module or
287   /// precompiled header, this module map will be used to determine
288   /// the module of origin of each Decl.
setPCHDescriptor(ExternalASTSource::ASTSourceDescriptor PCH)289   void setPCHDescriptor(ExternalASTSource::ASTSourceDescriptor PCH) {
290     PCHDescriptor = PCH;
291   }
292   /// @}
293 
294   /// Update the current source location. If \arg loc is invalid it is
295   /// ignored.
296   void setLocation(SourceLocation Loc);
297 
298   /// Emit metadata to indicate a change in line/column information in
299   /// the source file. If the location is invalid, the previous
300   /// location will be reused.
301   void EmitLocation(CGBuilderTy &Builder, SourceLocation Loc);
302 
303   /// Emit a call to llvm.dbg.function.start to indicate
304   /// start of a new function.
305   /// \param Loc       The location of the function header.
306   /// \param ScopeLoc  The location of the function body.
307   void EmitFunctionStart(GlobalDecl GD, SourceLocation Loc,
308                          SourceLocation ScopeLoc, QualType FnType,
309                          llvm::Function *Fn, CGBuilderTy &Builder);
310 
311   /// Emit debug info for a function declaration.
312   void EmitFunctionDecl(GlobalDecl GD, SourceLocation Loc, QualType FnType);
313 
314   /// Constructs the debug code for exiting a function.
315   void EmitFunctionEnd(CGBuilderTy &Builder);
316 
317   /// Emit metadata to indicate the beginning of a new lexical block
318   /// and push the block onto the stack.
319   void EmitLexicalBlockStart(CGBuilderTy &Builder, SourceLocation Loc);
320 
321   /// Emit metadata to indicate the end of a new lexical block and pop
322   /// the current block.
323   void EmitLexicalBlockEnd(CGBuilderTy &Builder, SourceLocation Loc);
324 
325   /// Emit call to \c llvm.dbg.declare for an automatic variable
326   /// declaration.
327   void EmitDeclareOfAutoVariable(const VarDecl *Decl, llvm::Value *AI,
328                                  CGBuilderTy &Builder);
329 
330   /// Emit call to \c llvm.dbg.declare for an imported variable
331   /// declaration in a block.
332   void EmitDeclareOfBlockDeclRefVariable(const VarDecl *variable,
333                                          llvm::Value *storage,
334                                          CGBuilderTy &Builder,
335                                          const CGBlockInfo &blockInfo,
336                                          llvm::Instruction *InsertPoint = nullptr);
337 
338   /// Emit call to \c llvm.dbg.declare for an argument variable
339   /// declaration.
340   void EmitDeclareOfArgVariable(const VarDecl *Decl, llvm::Value *AI,
341                                 unsigned ArgNo, CGBuilderTy &Builder);
342 
343   /// Emit call to \c llvm.dbg.declare for the block-literal argument
344   /// to a block invocation function.
345   void EmitDeclareOfBlockLiteralArgVariable(const CGBlockInfo &block,
346                                             llvm::Value *Arg, unsigned ArgNo,
347                                             llvm::Value *LocalAddr,
348                                             CGBuilderTy &Builder);
349 
350   /// Emit information about a global variable.
351   void EmitGlobalVariable(llvm::GlobalVariable *GV, const VarDecl *Decl);
352 
353   /// Emit global variable's debug info.
354   void EmitGlobalVariable(const ValueDecl *VD, llvm::Constant *Init);
355 
356   /// Emit C++ using directive.
357   void EmitUsingDirective(const UsingDirectiveDecl &UD);
358 
359   /// Emit the type explicitly casted to.
360   void EmitExplicitCastType(QualType Ty);
361 
362   /// Emit C++ using declaration.
363   void EmitUsingDecl(const UsingDecl &UD);
364 
365   /// Emit an @import declaration.
366   void EmitImportDecl(const ImportDecl &ID);
367 
368   /// Emit C++ namespace alias.
369   llvm::DIImportedEntity *EmitNamespaceAlias(const NamespaceAliasDecl &NA);
370 
371   /// Emit record type's standalone debug info.
372   llvm::DIType *getOrCreateRecordType(QualType Ty, SourceLocation L);
373 
374   /// Emit an Objective-C interface type standalone debug info.
375   llvm::DIType *getOrCreateInterfaceType(QualType Ty, SourceLocation Loc);
376 
377   /// Emit standalone debug info for a type.
378   llvm::DIType *getOrCreateStandaloneType(QualType Ty, SourceLocation Loc);
379 
380   void completeType(const EnumDecl *ED);
381   void completeType(const RecordDecl *RD);
382   void completeRequiredType(const RecordDecl *RD);
383   void completeClassData(const RecordDecl *RD);
384 
385   void completeTemplateDefinition(const ClassTemplateSpecializationDecl &SD);
386 
387 private:
388   /// Emit call to llvm.dbg.declare for a variable declaration.
389   void EmitDeclare(const VarDecl *decl, llvm::Value *AI,
390                    llvm::Optional<unsigned> ArgNo, CGBuilderTy &Builder);
391 
392   /// Build up structure info for the byref.  See \a BuildByRefType.
393   llvm::DIType *EmitTypeForVarWithBlocksAttr(const VarDecl *VD,
394                                              uint64_t *OffSet);
395 
396   /// Get context info for the DeclContext of \p Decl.
397   llvm::DIScope *getDeclContextDescriptor(const Decl *D);
398   /// Get context info for a given DeclContext \p Decl.
399   llvm::DIScope *getContextDescriptor(const Decl *Context,
400                                       llvm::DIScope *Default);
401 
402   llvm::DIScope *getCurrentContextDescriptor(const Decl *Decl);
403 
404   /// Create a forward decl for a RecordType in a given context.
405   llvm::DICompositeType *getOrCreateRecordFwdDecl(const RecordType *,
406                                                   llvm::DIScope *);
407 
408   /// Return current directory name.
409   StringRef getCurrentDirname();
410 
411   /// Create new compile unit.
412   void CreateCompileUnit();
413 
414   /// Remap a given path with the current debug prefix map
415   std::string remapDIPath(StringRef) const;
416 
417   /// Get the file debug info descriptor for the input location.
418   llvm::DIFile *getOrCreateFile(SourceLocation Loc);
419 
420   /// Get the file info for main compile unit.
421   llvm::DIFile *getOrCreateMainFile();
422 
423   /// Get the type from the cache or create a new type if necessary.
424   llvm::DIType *getOrCreateType(QualType Ty, llvm::DIFile *Fg);
425 
426   /// Get a reference to a clang module.  If \p CreateSkeletonCU is true,
427   /// this also creates a split dwarf skeleton compile unit.
428   llvm::DIModule *
429   getOrCreateModuleRef(ExternalASTSource::ASTSourceDescriptor Mod,
430                        bool CreateSkeletonCU);
431 
432   /// DebugTypeExtRefs: If \p D originated in a clang module, return it.
433   llvm::DIModule *getParentModuleOrNull(const Decl *D);
434 
435   /// Get the type from the cache or create a new partial type if
436   /// necessary.
437   llvm::DICompositeType *getOrCreateLimitedType(const RecordType *Ty,
438                                                 llvm::DIFile *F);
439 
440   /// Create type metadata for a source language type.
441   llvm::DIType *CreateTypeNode(QualType Ty, llvm::DIFile *Fg);
442 
443   /// Create new member and increase Offset by FType's size.
444   llvm::DIType *CreateMemberType(llvm::DIFile *Unit, QualType FType,
445                                  StringRef Name, uint64_t *Offset);
446 
447   /// Retrieve the DIDescriptor, if any, for the canonical form of this
448   /// declaration.
449   llvm::DINode *getDeclarationOrDefinition(const Decl *D);
450 
451   /// \return debug info descriptor to describe method
452   /// declaration for the given method definition.
453   llvm::DISubprogram *getFunctionDeclaration(const Decl *D);
454 
455   /// \return debug info descriptor to describe in-class static data
456   /// member declaration for the given out-of-class definition.  If D
457   /// is an out-of-class definition of a static data member of a
458   /// class, find its corresponding in-class declaration.
459   llvm::DIDerivedType *
460   getOrCreateStaticDataMemberDeclarationOrNull(const VarDecl *D);
461 
462   /// Create a subprogram describing the forward declaration
463   /// represented in the given FunctionDecl.
464   llvm::DISubprogram *getFunctionForwardDeclaration(const FunctionDecl *FD);
465 
466   /// Create a global variable describing the forward decalration
467   /// represented in the given VarDecl.
468   llvm::DIGlobalVariable *
469   getGlobalVariableForwardDeclaration(const VarDecl *VD);
470 
471   /// \brief Return a global variable that represents one of the
472   /// collection of global variables created for an anonmyous union.
473   ///
474   /// Recursively collect all of the member fields of a global
475   /// anonymous decl and create static variables for them. The first
476   /// time this is called it needs to be on a union and then from
477   /// there we can have additional unnamed fields.
478   llvm::DIGlobalVariable *
479   CollectAnonRecordDecls(const RecordDecl *RD, llvm::DIFile *Unit,
480                          unsigned LineNo, StringRef LinkageName,
481                          llvm::GlobalVariable *Var, llvm::DIScope *DContext);
482 
483   /// Get function name for the given FunctionDecl. If the name is
484   /// constructed on demand (e.g., C++ destructor) then the name is
485   /// stored on the side.
486   StringRef getFunctionName(const FunctionDecl *FD);
487 
488   /// Returns the unmangled name of an Objective-C method.
489   /// This is the display name for the debugging info.
490   StringRef getObjCMethodName(const ObjCMethodDecl *FD);
491 
492   /// Return selector name. This is used for debugging
493   /// info.
494   StringRef getSelectorName(Selector S);
495 
496   /// Get class name including template argument list.
497   StringRef getClassName(const RecordDecl *RD);
498 
499   /// Get the vtable name for the given class.
500   StringRef getVTableName(const CXXRecordDecl *Decl);
501 
502   /// Get line number for the location. If location is invalid
503   /// then use current location.
504   unsigned getLineNumber(SourceLocation Loc);
505 
506   /// Get column number for the location. If location is
507   /// invalid then use current location.
508   /// \param Force  Assume DebugColumnInfo option is true.
509   unsigned getColumnNumber(SourceLocation Loc, bool Force = false);
510 
511   /// Collect various properties of a FunctionDecl.
512   /// \param GD  A GlobalDecl whose getDecl() must return a FunctionDecl.
513   void collectFunctionDeclProps(GlobalDecl GD, llvm::DIFile *Unit,
514                                 StringRef &Name, StringRef &LinkageName,
515                                 llvm::DIScope *&FDContext,
516                                 llvm::DINodeArray &TParamsArray,
517                                 unsigned &Flags);
518 
519   /// Collect various properties of a VarDecl.
520   void collectVarDeclProps(const VarDecl *VD, llvm::DIFile *&Unit,
521                            unsigned &LineNo, QualType &T, StringRef &Name,
522                            StringRef &LinkageName, llvm::DIScope *&VDContext);
523 
524   /// Allocate a copy of \p A using the DebugInfoNames allocator
525   /// and return a reference to it. If multiple arguments are given the strings
526   /// are concatenated.
527   StringRef internString(StringRef A, StringRef B = StringRef()) {
528     char *Data = DebugInfoNames.Allocate<char>(A.size() + B.size());
529     if (!A.empty())
530       std::memcpy(Data, A.data(), A.size());
531     if (!B.empty())
532       std::memcpy(Data + A.size(), B.data(), B.size());
533     return StringRef(Data, A.size() + B.size());
534   }
535 };
536 
537 /// A scoped helper to set the current debug location to the specified
538 /// location or preferred location of the specified Expr.
539 class ApplyDebugLocation {
540 private:
541   void init(SourceLocation TemporaryLocation, bool DefaultToEmpty = false);
542   ApplyDebugLocation(CodeGenFunction &CGF, bool DefaultToEmpty,
543                      SourceLocation TemporaryLocation);
544 
545   llvm::DebugLoc OriginalLocation;
546   CodeGenFunction *CGF;
547 
548 public:
549   /// Set the location to the (valid) TemporaryLocation.
550   ApplyDebugLocation(CodeGenFunction &CGF, SourceLocation TemporaryLocation);
551   ApplyDebugLocation(CodeGenFunction &CGF, const Expr *E);
552   ApplyDebugLocation(CodeGenFunction &CGF, llvm::DebugLoc Loc);
ApplyDebugLocation(ApplyDebugLocation && Other)553   ApplyDebugLocation(ApplyDebugLocation &&Other) : CGF(Other.CGF) {
554     Other.CGF = nullptr;
555   }
556 
557   ~ApplyDebugLocation();
558 
559   /// \brief Apply TemporaryLocation if it is valid. Otherwise switch
560   /// to an artificial debug location that has a valid scope, but no
561   /// line information.
562   ///
563   /// Artificial locations are useful when emitting compiler-generated
564   /// helper functions that have no source location associated with
565   /// them. The DWARF specification allows the compiler to use the
566   /// special line number 0 to indicate code that can not be
567   /// attributed to any source location. Note that passing an empty
568   /// SourceLocation to CGDebugInfo::setLocation() will result in the
569   /// last valid location being reused.
CreateArtificial(CodeGenFunction & CGF)570   static ApplyDebugLocation CreateArtificial(CodeGenFunction &CGF) {
571     return ApplyDebugLocation(CGF, false, SourceLocation());
572   }
573   /// \brief Apply TemporaryLocation if it is valid. Otherwise switch
574   /// to an artificial debug location that has a valid scope, but no
575   /// line information.
576   static ApplyDebugLocation
CreateDefaultArtificial(CodeGenFunction & CGF,SourceLocation TemporaryLocation)577   CreateDefaultArtificial(CodeGenFunction &CGF,
578                           SourceLocation TemporaryLocation) {
579     return ApplyDebugLocation(CGF, false, TemporaryLocation);
580   }
581 
582   /// Set the IRBuilder to not attach debug locations.  Note that
583   /// passing an empty SourceLocation to \a CGDebugInfo::setLocation()
584   /// will result in the last valid location being reused.  Note that
585   /// all instructions that do not have a location at the beginning of
586   /// a function are counted towards to function prologue.
CreateEmpty(CodeGenFunction & CGF)587   static ApplyDebugLocation CreateEmpty(CodeGenFunction &CGF) {
588     return ApplyDebugLocation(CGF, true, SourceLocation());
589   }
590 
591 };
592 
593 } // namespace CodeGen
594 } // namespace clang
595 
596 #endif // LLVM_CLANG_LIB_CODEGEN_CGDEBUGINFO_H
597