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/Type.h"
20 #include "clang/Basic/SourceLocation.h"
21 #include "clang/Frontend/CodeGenOptions.h"
22 #include "llvm/ADT/DenseMap.h"
23 #include "llvm/ADT/Optional.h"
24 #include "llvm/IR/DIBuilder.h"
25 #include "llvm/IR/DebugInfo.h"
26 #include "llvm/IR/ValueHandle.h"
27 #include "llvm/Support/Allocator.h"
28 
29 namespace llvm {
30 class MDNode;
31 }
32 
33 namespace clang {
34 class CXXMethodDecl;
35 class ClassTemplateSpecializationDecl;
36 class GlobalDecl;
37 class ModuleMap;
38 class ObjCInterfaceDecl;
39 class ObjCIvarDecl;
40 class UsingDecl;
41 class VarDecl;
42 
43 namespace CodeGen {
44 class CodeGenModule;
45 class CodeGenFunction;
46 class CGBlockInfo;
47 
48 /// This class gathers all debug information during compilation and is
49 /// responsible for emitting to llvm globals or pass directly to the
50 /// backend.
51 class CGDebugInfo {
52   friend class ApplyDebugLocation;
53   friend class SaveAndRestoreLocation;
54   CodeGenModule &CGM;
55   const CodeGenOptions::DebugInfoKind DebugKind;
56   bool DebugTypeExtRefs;
57   llvm::DIBuilder DBuilder;
58   llvm::DICompileUnit *TheCU = nullptr;
59   ModuleMap *ClangModuleMap = nullptr;
60   SourceLocation CurLoc;
61   llvm::DIType *VTablePtrType = nullptr;
62   llvm::DIType *ClassTy = nullptr;
63   llvm::DICompositeType *ObjTy = nullptr;
64   llvm::DIType *SelTy = nullptr;
65   llvm::DIType *OCLImage1dDITy = nullptr;
66   llvm::DIType *OCLImage1dArrayDITy = nullptr;
67   llvm::DIType *OCLImage1dBufferDITy = nullptr;
68   llvm::DIType *OCLImage2dDITy = nullptr;
69   llvm::DIType *OCLImage2dArrayDITy = nullptr;
70   llvm::DIType *OCLImage2dDepthDITy = nullptr;
71   llvm::DIType *OCLImage2dArrayDepthDITy = nullptr;
72   llvm::DIType *OCLImage2dMSAADITy = nullptr;
73   llvm::DIType *OCLImage2dArrayMSAADITy = nullptr;
74   llvm::DIType *OCLImage2dMSAADepthDITy = nullptr;
75   llvm::DIType *OCLImage2dArrayMSAADepthDITy = nullptr;
76   llvm::DIType *OCLImage3dDITy = nullptr;
77   llvm::DIType *OCLEventDITy = nullptr;
78   llvm::DIType *OCLClkEventDITy = nullptr;
79   llvm::DIType *OCLQueueDITy = nullptr;
80   llvm::DIType *OCLNDRangeDITy = nullptr;
81   llvm::DIType *OCLReserveIDDITy = nullptr;
82 
83   /// Cache of previously constructed Types.
84   llvm::DenseMap<const void *, llvm::TrackingMDRef> TypeCache;
85 
86   llvm::SmallDenseMap<llvm::StringRef, llvm::StringRef> DebugPrefixMap;
87 
88   struct ObjCInterfaceCacheEntry {
89     const ObjCInterfaceType *Type;
90     llvm::DIType *Decl;
91     llvm::DIFile *Unit;
ObjCInterfaceCacheEntryObjCInterfaceCacheEntry92     ObjCInterfaceCacheEntry(const ObjCInterfaceType *Type, llvm::DIType *Decl,
93                             llvm::DIFile *Unit)
94         : Type(Type), Decl(Decl), Unit(Unit) {}
95   };
96 
97   /// Cache of previously constructed interfaces which may change.
98   llvm::SmallVector<ObjCInterfaceCacheEntry, 32> ObjCInterfaceCache;
99 
100   /// Cache of references to clang modules and precompiled headers.
101   llvm::DenseMap<const Module *, llvm::TrackingMDRef> ModuleCache;
102 
103   /// List of interfaces we want to keep even if orphaned.
104   std::vector<void *> RetainedTypes;
105 
106   /// Cache of forward declared types to RAUW at the end of
107   /// compilation.
108   std::vector<std::pair<const TagType *, llvm::TrackingMDRef>> ReplaceMap;
109 
110   /// Cache of replaceable forward declarartions (functions and
111   /// variables) to RAUW at the end of compilation.
112   std::vector<std::pair<const DeclaratorDecl *, llvm::TrackingMDRef>>
113       FwdDeclReplaceMap;
114 
115   /// Keep track of our current nested lexical block.
116   std::vector<llvm::TypedTrackingMDRef<llvm::DIScope>> LexicalBlockStack;
117   llvm::DenseMap<const Decl *, llvm::TrackingMDRef> RegionMap;
118   /// Keep track of LexicalBlockStack counter at the beginning of a
119   /// function. This is used to pop unbalanced regions at the end of a
120   /// function.
121   std::vector<unsigned> FnBeginRegionCount;
122 
123   /// This is a storage for names that are constructed on demand. For
124   /// example, C++ destructors, C++ operators etc..
125   llvm::BumpPtrAllocator DebugInfoNames;
126   StringRef CWDName;
127 
128   llvm::DenseMap<const char *, llvm::TrackingMDRef> DIFileCache;
129   llvm::DenseMap<const FunctionDecl *, llvm::TrackingMDRef> SPCache;
130   /// Cache declarations relevant to DW_TAG_imported_declarations (C++
131   /// using declarations) that aren't covered by other more specific caches.
132   llvm::DenseMap<const Decl *, llvm::TrackingMDRef> DeclCache;
133   llvm::DenseMap<const NamespaceDecl *, llvm::TrackingMDRef> NameSpaceCache;
134   llvm::DenseMap<const NamespaceAliasDecl *, llvm::TrackingMDRef>
135       NamespaceAliasCache;
136   llvm::DenseMap<const Decl *, llvm::TypedTrackingMDRef<llvm::DIDerivedType>>
137       StaticDataMemberCache;
138 
139   /// Helper functions for getOrCreateType.
140   /// @{
141   /// Currently the checksum of an interface includes the number of
142   /// ivars and property accessors.
143   llvm::DIType *CreateType(const BuiltinType *Ty);
144   llvm::DIType *CreateType(const ComplexType *Ty);
145   llvm::DIType *CreateQualifiedType(QualType Ty, llvm::DIFile *Fg);
146   llvm::DIType *CreateType(const TypedefType *Ty, llvm::DIFile *Fg);
147   llvm::DIType *CreateType(const TemplateSpecializationType *Ty,
148                            llvm::DIFile *Fg);
149   llvm::DIType *CreateType(const ObjCObjectPointerType *Ty, llvm::DIFile *F);
150   llvm::DIType *CreateType(const PointerType *Ty, llvm::DIFile *F);
151   llvm::DIType *CreateType(const BlockPointerType *Ty, llvm::DIFile *F);
152   llvm::DIType *CreateType(const FunctionType *Ty, llvm::DIFile *F);
153   /// Get structure or union type.
154   llvm::DIType *CreateType(const RecordType *Tyg);
155   llvm::DIType *CreateTypeDefinition(const RecordType *Ty);
156   llvm::DICompositeType *CreateLimitedType(const RecordType *Ty);
157   void CollectContainingType(const CXXRecordDecl *RD,
158                              llvm::DICompositeType *CT);
159   /// Get Objective-C interface type.
160   llvm::DIType *CreateType(const ObjCInterfaceType *Ty, llvm::DIFile *F);
161   llvm::DIType *CreateTypeDefinition(const ObjCInterfaceType *Ty,
162                                      llvm::DIFile *F);
163   /// Get Objective-C object type.
164   llvm::DIType *CreateType(const ObjCObjectType *Ty, llvm::DIFile *F);
165   llvm::DIType *CreateType(const VectorType *Ty, llvm::DIFile *F);
166   llvm::DIType *CreateType(const ArrayType *Ty, llvm::DIFile *F);
167   llvm::DIType *CreateType(const LValueReferenceType *Ty, llvm::DIFile *F);
168   llvm::DIType *CreateType(const RValueReferenceType *Ty, llvm::DIFile *Unit);
169   llvm::DIType *CreateType(const MemberPointerType *Ty, llvm::DIFile *F);
170   llvm::DIType *CreateType(const AtomicType *Ty, llvm::DIFile *F);
171   /// Get enumeration type.
172   llvm::DIType *CreateEnumType(const EnumType *Ty);
173   llvm::DIType *CreateTypeDefinition(const EnumType *Ty);
174   /// Look up the completed type for a self pointer in the TypeCache and
175   /// create a copy of it with the ObjectPointer and Artificial flags
176   /// set. If the type is not cached, a new one is created. This should
177   /// never happen though, since creating a type for the implicit self
178   /// argument implies that we already parsed the interface definition
179   /// and the ivar declarations in the implementation.
180   llvm::DIType *CreateSelfType(const QualType &QualTy, llvm::DIType *Ty);
181   /// @}
182 
183   /// Get the type from the cache or return null type if it doesn't
184   /// exist.
185   llvm::DIType *getTypeOrNull(const QualType);
186   /// Return the debug type for a C++ method.
187   /// \arg CXXMethodDecl is of FunctionType. This function type is
188   /// not updated to include implicit \c this pointer. Use this routine
189   /// to get a method type which includes \c this pointer.
190   llvm::DISubroutineType *getOrCreateMethodType(const CXXMethodDecl *Method,
191                                                 llvm::DIFile *F);
192   llvm::DISubroutineType *
193   getOrCreateInstanceMethodType(QualType ThisPtr, const FunctionProtoType *Func,
194                                 llvm::DIFile *Unit);
195   llvm::DISubroutineType *
196   getOrCreateFunctionType(const Decl *D, QualType FnType, llvm::DIFile *F);
197   /// \return debug info descriptor for vtable.
198   llvm::DIType *getOrCreateVTablePtrType(llvm::DIFile *F);
199   /// \return namespace descriptor for the given namespace decl.
200   llvm::DINamespace *getOrCreateNameSpace(const NamespaceDecl *N);
201   llvm::DIType *CreatePointerLikeType(llvm::dwarf::Tag Tag, const Type *Ty,
202                                       QualType PointeeTy, llvm::DIFile *F);
203   llvm::DIType *getOrCreateStructPtrType(StringRef Name, llvm::DIType *&Cache);
204 
205   /// A helper function to create a subprogram for a single member
206   /// function GlobalDecl.
207   llvm::DISubprogram *CreateCXXMemberFunction(const CXXMethodDecl *Method,
208                                               llvm::DIFile *F,
209                                               llvm::DIType *RecordTy);
210 
211   /// A helper function to collect debug info for C++ member
212   /// functions. This is used while creating debug info entry for a
213   /// Record.
214   void CollectCXXMemberFunctions(const CXXRecordDecl *Decl, llvm::DIFile *F,
215                                  SmallVectorImpl<llvm::Metadata *> &E,
216                                  llvm::DIType *T);
217 
218   /// A helper function to collect debug info for C++ base
219   /// classes. This is used while creating debug info entry for a
220   /// Record.
221   void CollectCXXBases(const CXXRecordDecl *Decl, llvm::DIFile *F,
222                        SmallVectorImpl<llvm::Metadata *> &EltTys,
223                        llvm::DIType *RecordTy);
224 
225   /// A helper function to collect template parameters.
226   llvm::DINodeArray CollectTemplateParams(const TemplateParameterList *TPList,
227                                           ArrayRef<TemplateArgument> TAList,
228                                           llvm::DIFile *Unit);
229   /// A helper function to collect debug info for function template
230   /// parameters.
231   llvm::DINodeArray CollectFunctionTemplateParams(const FunctionDecl *FD,
232                                                   llvm::DIFile *Unit);
233 
234   /// A helper function to collect debug info for template
235   /// parameters.
236   llvm::DINodeArray
237   CollectCXXTemplateParams(const ClassTemplateSpecializationDecl *TS,
238                            llvm::DIFile *F);
239 
240   llvm::DIType *createFieldType(StringRef name, QualType type,
241                                 uint64_t sizeInBitsOverride, SourceLocation loc,
242                                 AccessSpecifier AS, uint64_t offsetInBits,
243                                 llvm::DIFile *tunit, llvm::DIScope *scope,
244                                 const RecordDecl *RD = nullptr);
245 
246   /// Helpers for collecting fields of a record.
247   /// @{
248   void CollectRecordLambdaFields(const CXXRecordDecl *CXXDecl,
249                                  SmallVectorImpl<llvm::Metadata *> &E,
250                                  llvm::DIType *RecordTy);
251   llvm::DIDerivedType *CreateRecordStaticField(const VarDecl *Var,
252                                                llvm::DIType *RecordTy,
253                                                const RecordDecl *RD);
254   void CollectRecordNormalField(const FieldDecl *Field, uint64_t OffsetInBits,
255                                 llvm::DIFile *F,
256                                 SmallVectorImpl<llvm::Metadata *> &E,
257                                 llvm::DIType *RecordTy, const RecordDecl *RD);
258   void CollectRecordFields(const RecordDecl *Decl, llvm::DIFile *F,
259                            SmallVectorImpl<llvm::Metadata *> &E,
260                            llvm::DICompositeType *RecordTy);
261 
262   /// If the C++ class has vtable info then insert appropriate debug
263   /// info entry in EltTys vector.
264   void CollectVTableInfo(const CXXRecordDecl *Decl, llvm::DIFile *F,
265                          SmallVectorImpl<llvm::Metadata *> &EltTys);
266   /// @}
267 
268   /// Create a new lexical block node and push it on the stack.
269   void CreateLexicalBlock(SourceLocation Loc);
270 
271 public:
272   CGDebugInfo(CodeGenModule &CGM);
273   ~CGDebugInfo();
274 
275   void finalize();
276 
277   /// Set the main CU's DwoId field to \p Signature.
278   void setDwoId(uint64_t Signature);
279 
280   /// When generating debug information for a clang module or
281   /// precompiled header, this module map will be used to determine
282   /// the module of origin of each Decl.
setModuleMap(ModuleMap & MMap)283   void setModuleMap(ModuleMap &MMap) { ClangModuleMap = &MMap; }
284 
285   /// Update the current source location. If \arg loc is invalid it is
286   /// ignored.
287   void setLocation(SourceLocation Loc);
288 
289   /// Emit metadata to indicate a change in line/column information in
290   /// the source file. If the location is invalid, the previous
291   /// location will be reused.
292   void EmitLocation(CGBuilderTy &Builder, SourceLocation Loc);
293 
294   /// Emit a call to llvm.dbg.function.start to indicate
295   /// start of a new function.
296   /// \param Loc       The location of the function header.
297   /// \param ScopeLoc  The location of the function body.
298   void EmitFunctionStart(GlobalDecl GD, SourceLocation Loc,
299                          SourceLocation ScopeLoc, QualType FnType,
300                          llvm::Function *Fn, CGBuilderTy &Builder);
301 
302   /// Emit debug info for a function declaration.
303   void EmitFunctionDecl(GlobalDecl GD, SourceLocation Loc, QualType FnType);
304 
305   /// Constructs the debug code for exiting a function.
306   void EmitFunctionEnd(CGBuilderTy &Builder);
307 
308   /// Emit metadata to indicate the beginning of a new lexical block
309   /// and push the block onto the stack.
310   void EmitLexicalBlockStart(CGBuilderTy &Builder, SourceLocation Loc);
311 
312   /// Emit metadata to indicate the end of a new lexical block and pop
313   /// the current block.
314   void EmitLexicalBlockEnd(CGBuilderTy &Builder, SourceLocation Loc);
315 
316   /// Emit call to \c llvm.dbg.declare for an automatic variable
317   /// declaration.
318   void EmitDeclareOfAutoVariable(const VarDecl *Decl, llvm::Value *AI,
319                                  CGBuilderTy &Builder);
320 
321   /// Emit call to \c llvm.dbg.declare for an imported variable
322   /// declaration in a block.
323   void EmitDeclareOfBlockDeclRefVariable(const VarDecl *variable,
324                                          llvm::Value *storage,
325                                          CGBuilderTy &Builder,
326                                          const CGBlockInfo &blockInfo,
327                                          llvm::Instruction *InsertPoint = nullptr);
328 
329   /// Emit call to \c llvm.dbg.declare for an argument variable
330   /// declaration.
331   void EmitDeclareOfArgVariable(const VarDecl *Decl, llvm::Value *AI,
332                                 unsigned ArgNo, CGBuilderTy &Builder);
333 
334   /// Emit call to \c llvm.dbg.declare for the block-literal argument
335   /// to a block invocation function.
336   void EmitDeclareOfBlockLiteralArgVariable(const CGBlockInfo &block,
337                                             llvm::Value *Arg, unsigned ArgNo,
338                                             llvm::Value *LocalAddr,
339                                             CGBuilderTy &Builder);
340 
341   /// Emit information about a global variable.
342   void EmitGlobalVariable(llvm::GlobalVariable *GV, const VarDecl *Decl);
343 
344   /// Emit global variable's debug info.
345   void EmitGlobalVariable(const ValueDecl *VD, llvm::Constant *Init);
346 
347   /// Emit C++ using directive.
348   void EmitUsingDirective(const UsingDirectiveDecl &UD);
349 
350   /// Emit the type explicitly casted to.
351   void EmitExplicitCastType(QualType Ty);
352 
353   /// Emit C++ using declaration.
354   void EmitUsingDecl(const UsingDecl &UD);
355 
356   /// Emit an @import declaration.
357   void EmitImportDecl(const ImportDecl &ID);
358 
359   /// Emit C++ namespace alias.
360   llvm::DIImportedEntity *EmitNamespaceAlias(const NamespaceAliasDecl &NA);
361 
362   /// Emit record type's standalone debug info.
363   llvm::DIType *getOrCreateRecordType(QualType Ty, SourceLocation L);
364 
365   /// Emit an Objective-C interface type standalone debug info.
366   llvm::DIType *getOrCreateInterfaceType(QualType Ty, SourceLocation Loc);
367 
368   /// Emit standalone debug info for a type.
369   llvm::DIType *getOrCreateStandaloneType(QualType Ty, SourceLocation Loc);
370 
371   void completeType(const EnumDecl *ED);
372   void completeType(const RecordDecl *RD);
373   void completeRequiredType(const RecordDecl *RD);
374   void completeClassData(const RecordDecl *RD);
375 
376   void completeTemplateDefinition(const ClassTemplateSpecializationDecl &SD);
377 
378 private:
379   /// Emit call to llvm.dbg.declare for a variable declaration.
380   void EmitDeclare(const VarDecl *decl, llvm::Value *AI,
381                    llvm::Optional<unsigned> ArgNo, CGBuilderTy &Builder);
382 
383   /// Build up structure info for the byref.  See \a BuildByRefType.
384   llvm::DIType *EmitTypeForVarWithBlocksAttr(const VarDecl *VD,
385                                              uint64_t *OffSet);
386 
387   /// Get context info for the DeclContext of \p Decl.
388   llvm::DIScope *getDeclContextDescriptor(const Decl *D);
389   /// Get context info for a given DeclContext \p Decl.
390   llvm::DIScope *getContextDescriptor(const Decl *Context,
391                                       llvm::DIScope *Default);
392 
393   llvm::DIScope *getCurrentContextDescriptor(const Decl *Decl);
394 
395   /// Create a forward decl for a RecordType in a given context.
396   llvm::DICompositeType *getOrCreateRecordFwdDecl(const RecordType *,
397                                                   llvm::DIScope *);
398 
399   /// Return current directory name.
400   StringRef getCurrentDirname();
401 
402   /// Create new compile unit.
403   void CreateCompileUnit();
404 
405   /// Remap a given path with the current debug prefix map
406   std::string remapDIPath(StringRef) const;
407 
408   /// Get the file debug info descriptor for the input location.
409   llvm::DIFile *getOrCreateFile(SourceLocation Loc);
410 
411   /// Get the file info for main compile unit.
412   llvm::DIFile *getOrCreateMainFile();
413 
414   /// Get the type from the cache or create a new type if necessary.
415   llvm::DIType *getOrCreateType(QualType Ty, llvm::DIFile *Fg);
416 
417   /// Get a reference to a clang module.  If \p CreateSkeletonCU is true,
418   /// this also creates a split dwarf skeleton compile unit.
419   llvm::DIModule *
420   getOrCreateModuleRef(ExternalASTSource::ASTSourceDescriptor Mod,
421                        bool CreateSkeletonCU);
422 
423   /// DebugTypeExtRefs: If \p D originated in a clang module, return it.
424   llvm::DIModule *getParentModuleOrNull(const Decl *D);
425 
426   /// Get the type from the cache or create a new partial type if
427   /// necessary.
428   llvm::DICompositeType *getOrCreateLimitedType(const RecordType *Ty,
429                                                 llvm::DIFile *F);
430 
431   /// Create type metadata for a source language type.
432   llvm::DIType *CreateTypeNode(QualType Ty, llvm::DIFile *Fg);
433 
434   /// Create new member and increase Offset by FType's size.
435   llvm::DIType *CreateMemberType(llvm::DIFile *Unit, QualType FType,
436                                  StringRef Name, uint64_t *Offset);
437 
438   /// Retrieve the DIDescriptor, if any, for the canonical form of this
439   /// declaration.
440   llvm::DINode *getDeclarationOrDefinition(const Decl *D);
441 
442   /// \return debug info descriptor to describe method
443   /// declaration for the given method definition.
444   llvm::DISubprogram *getFunctionDeclaration(const Decl *D);
445 
446   /// \return debug info descriptor to describe in-class static data
447   /// member declaration for the given out-of-class definition.  If D
448   /// is an out-of-class definition of a static data member of a
449   /// class, find its corresponding in-class declaration.
450   llvm::DIDerivedType *
451   getOrCreateStaticDataMemberDeclarationOrNull(const VarDecl *D);
452 
453   /// Create a subprogram describing the forward declaration
454   /// represented in the given FunctionDecl.
455   llvm::DISubprogram *getFunctionForwardDeclaration(const FunctionDecl *FD);
456 
457   /// Create a global variable describing the forward decalration
458   /// represented in the given VarDecl.
459   llvm::DIGlobalVariable *
460   getGlobalVariableForwardDeclaration(const VarDecl *VD);
461 
462   /// \brief Return a global variable that represents one of the
463   /// collection of global variables created for an anonmyous union.
464   ///
465   /// Recursively collect all of the member fields of a global
466   /// anonymous decl and create static variables for them. The first
467   /// time this is called it needs to be on a union and then from
468   /// there we can have additional unnamed fields.
469   llvm::DIGlobalVariable *
470   CollectAnonRecordDecls(const RecordDecl *RD, llvm::DIFile *Unit,
471                          unsigned LineNo, StringRef LinkageName,
472                          llvm::GlobalVariable *Var, llvm::DIScope *DContext);
473 
474   /// Get function name for the given FunctionDecl. If the name is
475   /// constructed on demand (e.g., C++ destructor) then the name is
476   /// stored on the side.
477   StringRef getFunctionName(const FunctionDecl *FD);
478 
479   /// Returns the unmangled name of an Objective-C method.
480   /// This is the display name for the debugging info.
481   StringRef getObjCMethodName(const ObjCMethodDecl *FD);
482 
483   /// Return selector name. This is used for debugging
484   /// info.
485   StringRef getSelectorName(Selector S);
486 
487   /// Get class name including template argument list.
488   StringRef getClassName(const RecordDecl *RD);
489 
490   /// Get the vtable name for the given class.
491   StringRef getVTableName(const CXXRecordDecl *Decl);
492 
493   /// Get line number for the location. If location is invalid
494   /// then use current location.
495   unsigned getLineNumber(SourceLocation Loc);
496 
497   /// Get column number for the location. If location is
498   /// invalid then use current location.
499   /// \param Force  Assume DebugColumnInfo option is true.
500   unsigned getColumnNumber(SourceLocation Loc, bool Force = false);
501 
502   /// Collect various properties of a FunctionDecl.
503   /// \param GD  A GlobalDecl whose getDecl() must return a FunctionDecl.
504   void collectFunctionDeclProps(GlobalDecl GD, llvm::DIFile *Unit,
505                                 StringRef &Name, StringRef &LinkageName,
506                                 llvm::DIScope *&FDContext,
507                                 llvm::DINodeArray &TParamsArray,
508                                 unsigned &Flags);
509 
510   /// Collect various properties of a VarDecl.
511   void collectVarDeclProps(const VarDecl *VD, llvm::DIFile *&Unit,
512                            unsigned &LineNo, QualType &T, StringRef &Name,
513                            StringRef &LinkageName, llvm::DIScope *&VDContext);
514 
515   /// Allocate a copy of \p A using the DebugInfoNames allocator
516   /// and return a reference to it. If multiple arguments are given the strings
517   /// are concatenated.
518   StringRef internString(StringRef A, StringRef B = StringRef()) {
519     char *Data = DebugInfoNames.Allocate<char>(A.size() + B.size());
520     if (!A.empty())
521       std::memcpy(Data, A.data(), A.size());
522     if (!B.empty())
523       std::memcpy(Data + A.size(), B.data(), B.size());
524     return StringRef(Data, A.size() + B.size());
525   }
526 };
527 
528 /// A scoped helper to set the current debug location to the specified
529 /// location or preferred location of the specified Expr.
530 class ApplyDebugLocation {
531 private:
532   void init(SourceLocation TemporaryLocation, bool DefaultToEmpty = false);
533   ApplyDebugLocation(CodeGenFunction &CGF, bool DefaultToEmpty,
534                      SourceLocation TemporaryLocation);
535 
536   llvm::DebugLoc OriginalLocation;
537   CodeGenFunction *CGF;
538 
539 public:
540   /// Set the location to the (valid) TemporaryLocation.
541   ApplyDebugLocation(CodeGenFunction &CGF, SourceLocation TemporaryLocation);
542   ApplyDebugLocation(CodeGenFunction &CGF, const Expr *E);
543   ApplyDebugLocation(CodeGenFunction &CGF, llvm::DebugLoc Loc);
ApplyDebugLocation(ApplyDebugLocation && Other)544   ApplyDebugLocation(ApplyDebugLocation &&Other) : CGF(Other.CGF) {
545     Other.CGF = nullptr;
546   }
547 
548   ~ApplyDebugLocation();
549 
550   /// \brief Apply TemporaryLocation if it is valid. Otherwise switch
551   /// to an artificial debug location that has a valid scope, but no
552   /// line information.
553   ///
554   /// Artificial locations are useful when emitting compiler-generated
555   /// helper functions that have no source location associated with
556   /// them. The DWARF specification allows the compiler to use the
557   /// special line number 0 to indicate code that can not be
558   /// attributed to any source location. Note that passing an empty
559   /// SourceLocation to CGDebugInfo::setLocation() will result in the
560   /// last valid location being reused.
CreateArtificial(CodeGenFunction & CGF)561   static ApplyDebugLocation CreateArtificial(CodeGenFunction &CGF) {
562     return ApplyDebugLocation(CGF, false, SourceLocation());
563   }
564   /// \brief Apply TemporaryLocation if it is valid. Otherwise switch
565   /// to an artificial debug location that has a valid scope, but no
566   /// line information.
567   static ApplyDebugLocation
CreateDefaultArtificial(CodeGenFunction & CGF,SourceLocation TemporaryLocation)568   CreateDefaultArtificial(CodeGenFunction &CGF,
569                           SourceLocation TemporaryLocation) {
570     return ApplyDebugLocation(CGF, false, TemporaryLocation);
571   }
572 
573   /// Set the IRBuilder to not attach debug locations.  Note that
574   /// passing an empty SourceLocation to \a CGDebugInfo::setLocation()
575   /// will result in the last valid location being reused.  Note that
576   /// all instructions that do not have a location at the beginning of
577   /// a function are counted towards to function prologue.
CreateEmpty(CodeGenFunction & CGF)578   static ApplyDebugLocation CreateEmpty(CodeGenFunction &CGF) {
579     return ApplyDebugLocation(CGF, true, SourceLocation());
580   }
581 
582 };
583 
584 } // namespace CodeGen
585 } // namespace clang
586 
587 #endif // LLVM_CLANG_LIB_CODEGEN_CGDEBUGINFO_H
588