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/IR/DIBuilder.h"
24 #include "llvm/IR/DebugInfo.h"
25 #include "llvm/IR/ValueHandle.h"
26 #include "llvm/Support/Allocator.h"
27 
28 namespace llvm {
29   class MDNode;
30 }
31 
32 namespace clang {
33   class CXXMethodDecl;
34   class VarDecl;
35   class ObjCInterfaceDecl;
36   class ObjCIvarDecl;
37   class ClassTemplateSpecializationDecl;
38   class GlobalDecl;
39   class UsingDecl;
40 
41 namespace CodeGen {
42   class CodeGenModule;
43   class CodeGenFunction;
44   class CGBlockInfo;
45 
46 /// CGDebugInfo - This class gathers all debug information during compilation
47 /// and is responsible for emitting to llvm globals or pass directly to
48 /// the backend.
49 class CGDebugInfo {
50   friend class ArtificialLocation;
51   friend class SaveAndRestoreLocation;
52   CodeGenModule &CGM;
53   const CodeGenOptions::DebugInfoKind DebugKind;
54   llvm::DIBuilder DBuilder;
55   llvm::DICompileUnit TheCU;
56   SourceLocation CurLoc;
57   llvm::DIType VTablePtrType;
58   llvm::DIType ClassTy;
59   llvm::DICompositeType ObjTy;
60   llvm::DIType SelTy;
61   llvm::DIType OCLImage1dDITy, OCLImage1dArrayDITy, OCLImage1dBufferDITy;
62   llvm::DIType OCLImage2dDITy, OCLImage2dArrayDITy;
63   llvm::DIType OCLImage3dDITy;
64   llvm::DIType OCLEventDITy;
65   llvm::DIType BlockLiteralGeneric;
66 
67   /// TypeCache - Cache of previously constructed Types.
68   llvm::DenseMap<const void *, llvm::TrackingMDRef> TypeCache;
69 
70   struct ObjCInterfaceCacheEntry {
71     const ObjCInterfaceType *Type;
72     llvm::DIType Decl;
73     llvm::DIFile Unit;
74     ObjCInterfaceCacheEntry(const ObjCInterfaceType *Type, llvm::DIType Decl,
75                             llvm::DIFile Unit)
76         : Type(Type), Decl(Decl), Unit(Unit) {}
77   };
78 
79   /// ObjCInterfaceCache - Cache of previously constructed interfaces
80   /// which may change.
81   llvm::SmallVector<ObjCInterfaceCacheEntry, 32> ObjCInterfaceCache;
82 
83   /// RetainedTypes - list of interfaces we want to keep even if orphaned.
84   std::vector<void *> RetainedTypes;
85 
86   /// ReplaceMap - Cache of forward declared types to RAUW at the end of
87   /// compilation.
88   std::vector<std::pair<const TagType *, llvm::TrackingMDRef>> ReplaceMap;
89 
90   /// \brief Cache of replaceable forward declarartions (functions and
91   /// variables) to RAUW at the end of compilation.
92   std::vector<std::pair<const DeclaratorDecl *, llvm::TrackingMDRef>>
93       FwdDeclReplaceMap;
94 
95   // LexicalBlockStack - Keep track of our current nested lexical block.
96   std::vector<llvm::TrackingMDNodeRef> LexicalBlockStack;
97   llvm::DenseMap<const Decl *, llvm::TrackingMDRef> RegionMap;
98   // FnBeginRegionCount - Keep track of LexicalBlockStack counter at the
99   // beginning of a function. This is used to pop unbalanced regions at
100   // the end of a function.
101   std::vector<unsigned> FnBeginRegionCount;
102 
103   /// DebugInfoNames - This is a storage for names that are
104   /// constructed on demand. For example, C++ destructors, C++ operators etc..
105   llvm::BumpPtrAllocator DebugInfoNames;
106   StringRef CWDName;
107 
108   llvm::DenseMap<const char *, llvm::TrackingMDRef> DIFileCache;
109   llvm::DenseMap<const FunctionDecl *, llvm::TrackingMDRef> SPCache;
110   /// \brief Cache declarations relevant to DW_TAG_imported_declarations (C++
111   /// using declarations) that aren't covered by other more specific caches.
112   llvm::DenseMap<const Decl *, llvm::TrackingMDRef> DeclCache;
113   llvm::DenseMap<const NamespaceDecl *, llvm::TrackingMDRef> NameSpaceCache;
114   llvm::DenseMap<const NamespaceAliasDecl *, llvm::TrackingMDRef>
115       NamespaceAliasCache;
116   llvm::DenseMap<const Decl *, llvm::TrackingMDRef> StaticDataMemberCache;
117 
118   /// Helper functions for getOrCreateType.
119   unsigned Checksum(const ObjCInterfaceDecl *InterfaceDecl);
120   llvm::DIType CreateType(const BuiltinType *Ty);
121   llvm::DIType CreateType(const ComplexType *Ty);
122   llvm::DIType CreateQualifiedType(QualType Ty, llvm::DIFile Fg);
123   llvm::DIType CreateType(const TypedefType *Ty, llvm::DIFile Fg);
124   llvm::DIType CreateType(const TemplateSpecializationType *Ty, llvm::DIFile Fg);
125   llvm::DIType CreateType(const ObjCObjectPointerType *Ty,
126                           llvm::DIFile F);
127   llvm::DIType CreateType(const PointerType *Ty, llvm::DIFile F);
128   llvm::DIType CreateType(const BlockPointerType *Ty, llvm::DIFile F);
129   llvm::DIType CreateType(const FunctionType *Ty, llvm::DIFile F);
130   llvm::DIType CreateType(const RecordType *Tyg);
131   llvm::DIType CreateTypeDefinition(const RecordType *Ty);
132   llvm::DICompositeType CreateLimitedType(const RecordType *Ty);
133   void CollectContainingType(const CXXRecordDecl *RD, llvm::DICompositeType CT);
134   llvm::DIType CreateType(const ObjCInterfaceType *Ty, llvm::DIFile F);
135   llvm::DIType CreateTypeDefinition(const ObjCInterfaceType *Ty, llvm::DIFile F);
136   llvm::DIType CreateType(const ObjCObjectType *Ty, llvm::DIFile F);
137   llvm::DIType CreateType(const VectorType *Ty, llvm::DIFile F);
138   llvm::DIType CreateType(const ArrayType *Ty, llvm::DIFile F);
139   llvm::DIType CreateType(const LValueReferenceType *Ty, llvm::DIFile F);
140   llvm::DIType CreateType(const RValueReferenceType *Ty, llvm::DIFile Unit);
141   llvm::DIType CreateType(const MemberPointerType *Ty, llvm::DIFile F);
142   llvm::DIType CreateType(const AtomicType *Ty, llvm::DIFile F);
143   llvm::DIType CreateEnumType(const EnumType *Ty);
144   llvm::DIType CreateTypeDefinition(const EnumType *Ty);
145   llvm::DIType CreateSelfType(const QualType &QualTy, llvm::DIType Ty);
146   llvm::DIType getTypeOrNull(const QualType);
147   llvm::DICompositeType getOrCreateMethodType(const CXXMethodDecl *Method,
148                                               llvm::DIFile F);
149   llvm::DICompositeType getOrCreateInstanceMethodType(
150       QualType ThisPtr, const FunctionProtoType *Func, llvm::DIFile Unit);
151   llvm::DICompositeType getOrCreateFunctionType(const Decl *D, QualType FnType,
152                                                 llvm::DIFile F);
153   llvm::DIType getOrCreateVTablePtrType(llvm::DIFile F);
154   llvm::DINameSpace getOrCreateNameSpace(const NamespaceDecl *N);
155   llvm::DIType getOrCreateTypeDeclaration(QualType PointeeTy, llvm::DIFile F);
156   llvm::DIType CreatePointerLikeType(llvm::dwarf::Tag Tag,
157                                      const Type *Ty, QualType PointeeTy,
158                                      llvm::DIFile F);
159 
160   llvm::Value *getCachedInterfaceTypeOrNull(const QualType Ty);
161   llvm::DIType getOrCreateStructPtrType(StringRef Name, llvm::DIType &Cache);
162 
163   llvm::DISubprogram CreateCXXMemberFunction(const CXXMethodDecl *Method,
164                                              llvm::DIFile F,
165                                              llvm::DIType RecordTy);
166 
167   void CollectCXXMemberFunctions(const CXXRecordDecl *Decl, llvm::DIFile F,
168                                  SmallVectorImpl<llvm::Metadata *> &E,
169                                  llvm::DIType T);
170 
171   void CollectCXXBases(const CXXRecordDecl *Decl, llvm::DIFile F,
172                        SmallVectorImpl<llvm::Metadata *> &EltTys,
173                        llvm::DIType RecordTy);
174 
175   llvm::DIArray
176   CollectTemplateParams(const TemplateParameterList *TPList,
177                         ArrayRef<TemplateArgument> TAList,
178                         llvm::DIFile Unit);
179   llvm::DIArray
180   CollectFunctionTemplateParams(const FunctionDecl *FD, llvm::DIFile Unit);
181   llvm::DIArray
182   CollectCXXTemplateParams(const ClassTemplateSpecializationDecl *TS,
183                            llvm::DIFile F);
184 
185   llvm::DIType createFieldType(StringRef name, QualType type,
186                                uint64_t sizeInBitsOverride, SourceLocation loc,
187                                AccessSpecifier AS,
188                                uint64_t offsetInBits,
189                                llvm::DIFile tunit,
190                                llvm::DIScope scope,
191                                const RecordDecl* RD = nullptr);
192 
193   // Helpers for collecting fields of a record.
194   void CollectRecordLambdaFields(const CXXRecordDecl *CXXDecl,
195                                  SmallVectorImpl<llvm::Metadata *> &E,
196                                  llvm::DIType RecordTy);
197   llvm::DIDerivedType CreateRecordStaticField(const VarDecl *Var,
198                                               llvm::DIType RecordTy,
199                                               const RecordDecl* RD);
200   void CollectRecordNormalField(const FieldDecl *Field, uint64_t OffsetInBits,
201                                 llvm::DIFile F,
202                                 SmallVectorImpl<llvm::Metadata *> &E,
203                                 llvm::DIType RecordTy, const RecordDecl *RD);
204   void CollectRecordFields(const RecordDecl *Decl, llvm::DIFile F,
205                            SmallVectorImpl<llvm::Metadata *> &E,
206                            llvm::DICompositeType RecordTy);
207 
208   void CollectVTableInfo(const CXXRecordDecl *Decl, llvm::DIFile F,
209                          SmallVectorImpl<llvm::Metadata *> &EltTys);
210 
211   // CreateLexicalBlock - Create a new lexical block node and push it on
212   // the stack.
213   void CreateLexicalBlock(SourceLocation Loc);
214 
215 public:
216   CGDebugInfo(CodeGenModule &CGM);
217   ~CGDebugInfo();
218 
219   void finalize();
220 
221   /// setLocation - Update the current source location. If \arg loc is
222   /// invalid it is ignored.
223   void setLocation(SourceLocation Loc);
224 
225   /// EmitLocation - Emit metadata to indicate a change in line/column
226   /// information in the source file.
227   void EmitLocation(CGBuilderTy &Builder, SourceLocation Loc);
228 
229   /// EmitFunctionStart - Emit a call to llvm.dbg.function.start to indicate
230   /// start of a new function.
231   /// \param Loc       The location of the function header.
232   /// \param ScopeLoc  The location of the function body.
233   void EmitFunctionStart(GlobalDecl GD,
234                          SourceLocation Loc, SourceLocation ScopeLoc,
235                          QualType FnType, llvm::Function *Fn,
236                          CGBuilderTy &Builder);
237 
238   /// EmitFunctionEnd - Constructs the debug code for exiting a function.
239   void EmitFunctionEnd(CGBuilderTy &Builder);
240 
241   /// EmitLexicalBlockStart - Emit metadata to indicate the beginning of a
242   /// new lexical block and push the block onto the stack.
243   void EmitLexicalBlockStart(CGBuilderTy &Builder, SourceLocation Loc);
244 
245   /// EmitLexicalBlockEnd - Emit metadata to indicate the end of a new lexical
246   /// block and pop the current block.
247   void EmitLexicalBlockEnd(CGBuilderTy &Builder, SourceLocation Loc);
248 
249   /// EmitDeclareOfAutoVariable - Emit call to llvm.dbg.declare for an automatic
250   /// variable declaration.
251   void EmitDeclareOfAutoVariable(const VarDecl *Decl, llvm::Value *AI,
252                                  CGBuilderTy &Builder);
253 
254   /// EmitDeclareOfBlockDeclRefVariable - Emit call to llvm.dbg.declare for an
255   /// imported variable declaration in a block.
256   void EmitDeclareOfBlockDeclRefVariable(const VarDecl *variable,
257                                          llvm::Value *storage,
258                                          CGBuilderTy &Builder,
259                                          const CGBlockInfo &blockInfo,
260                                          llvm::Instruction *InsertPoint = 0);
261 
262   /// EmitDeclareOfArgVariable - Emit call to llvm.dbg.declare for an argument
263   /// variable declaration.
264   void EmitDeclareOfArgVariable(const VarDecl *Decl, llvm::Value *AI,
265                                 unsigned ArgNo, CGBuilderTy &Builder);
266 
267   /// EmitDeclareOfBlockLiteralArgVariable - Emit call to
268   /// llvm.dbg.declare for the block-literal argument to a block
269   /// invocation function.
270   void EmitDeclareOfBlockLiteralArgVariable(const CGBlockInfo &block,
271                                             llvm::Value *Arg, unsigned ArgNo,
272                                             llvm::Value *LocalAddr,
273                                             CGBuilderTy &Builder);
274 
275   /// EmitGlobalVariable - Emit information about a global variable.
276   void EmitGlobalVariable(llvm::GlobalVariable *GV, const VarDecl *Decl);
277 
278   /// EmitGlobalVariable - Emit global variable's debug info.
279   void EmitGlobalVariable(const ValueDecl *VD, llvm::Constant *Init);
280 
281   /// \brief - Emit C++ using directive.
282   void EmitUsingDirective(const UsingDirectiveDecl &UD);
283 
284   /// EmitExplicitCastType - Emit the type explicitly casted to.
285   void EmitExplicitCastType(QualType Ty);
286 
287   /// \brief - Emit C++ using declaration.
288   void EmitUsingDecl(const UsingDecl &UD);
289 
290   /// \brief - Emit C++ namespace alias.
291   llvm::DIImportedEntity EmitNamespaceAlias(const NamespaceAliasDecl &NA);
292 
293   /// getOrCreateRecordType - Emit record type's standalone debug info.
294   llvm::DIType getOrCreateRecordType(QualType Ty, SourceLocation L);
295 
296   /// getOrCreateInterfaceType - Emit an objective c interface type standalone
297   /// debug info.
298   llvm::DIType getOrCreateInterfaceType(QualType Ty,
299                                         SourceLocation Loc);
300 
301   void completeType(const EnumDecl *ED);
302   void completeType(const RecordDecl *RD);
303   void completeRequiredType(const RecordDecl *RD);
304   void completeClassData(const RecordDecl *RD);
305 
306   void completeTemplateDefinition(const ClassTemplateSpecializationDecl &SD);
307 
308 private:
309   /// EmitDeclare - Emit call to llvm.dbg.declare for a variable declaration.
310   /// Tag accepts custom types DW_TAG_arg_variable and DW_TAG_auto_variable,
311   /// otherwise would be of type llvm::dwarf::Tag.
312   void EmitDeclare(const VarDecl *decl, llvm::dwarf::LLVMConstants Tag,
313                    llvm::Value *AI, unsigned ArgNo, CGBuilderTy &Builder);
314 
315   // EmitTypeForVarWithBlocksAttr - Build up structure info for the byref.
316   // See BuildByRefType.
317   llvm::DIType EmitTypeForVarWithBlocksAttr(const VarDecl *VD,
318                                             uint64_t *OffSet);
319 
320   /// getContextDescriptor - Get context info for the decl.
321   llvm::DIScope getContextDescriptor(const Decl *Decl);
322 
323   llvm::DIScope getCurrentContextDescriptor(const Decl *Decl);
324 
325   /// \brief Create a forward decl for a RecordType in a given context.
326   llvm::DICompositeType getOrCreateRecordFwdDecl(const RecordType *,
327                                                  llvm::DIDescriptor);
328 
329   /// createContextChain - Create a set of decls for the context chain.
330   llvm::DIDescriptor createContextChain(const Decl *Decl);
331 
332   /// getCurrentDirname - Return current directory name.
333   StringRef getCurrentDirname();
334 
335   /// CreateCompileUnit - Create new compile unit.
336   void CreateCompileUnit();
337 
338   /// getOrCreateFile - Get the file debug info descriptor for the input
339   /// location.
340   llvm::DIFile getOrCreateFile(SourceLocation Loc);
341 
342   /// getOrCreateMainFile - Get the file info for main compile unit.
343   llvm::DIFile getOrCreateMainFile();
344 
345   /// getOrCreateType - Get the type from the cache or create a new type if
346   /// necessary.
347   llvm::DIType getOrCreateType(QualType Ty, llvm::DIFile Fg);
348 
349   /// getOrCreateLimitedType - Get the type from the cache or create a new
350   /// partial type if necessary.
351   llvm::DIType getOrCreateLimitedType(const RecordType *Ty, llvm::DIFile F);
352 
353   /// CreateTypeNode - Create type metadata for a source language type.
354   llvm::DIType CreateTypeNode(QualType Ty, llvm::DIFile Fg);
355 
356   /// getObjCInterfaceDecl - return the underlying ObjCInterfaceDecl
357   /// if Ty is an ObjCInterface or a pointer to one.
358   ObjCInterfaceDecl* getObjCInterfaceDecl(QualType Ty);
359 
360   /// CreateMemberType - Create new member and increase Offset by FType's size.
361   llvm::DIType CreateMemberType(llvm::DIFile Unit, QualType FType,
362                                 StringRef Name, uint64_t *Offset);
363 
364   /// \brief Retrieve the DIDescriptor, if any, for the canonical form of this
365   /// declaration.
366   llvm::DIDescriptor getDeclarationOrDefinition(const Decl *D);
367 
368   /// getFunctionDeclaration - Return debug info descriptor to describe method
369   /// declaration for the given method definition.
370   llvm::DISubprogram getFunctionDeclaration(const Decl *D);
371 
372   /// Return debug info descriptor to describe in-class static data member
373   /// declaration for the given out-of-class definition.
374   llvm::DIDerivedType
375   getOrCreateStaticDataMemberDeclarationOrNull(const VarDecl *D);
376 
377   /// \brief Create a DISubprogram describing the forward
378   /// decalration represented in the given FunctionDecl.
379   llvm::DISubprogram getFunctionForwardDeclaration(const FunctionDecl *FD);
380 
381   /// \brief Create a DIGlobalVariable describing the forward
382   /// decalration represented in the given VarDecl.
383   llvm::DIGlobalVariable getGlobalVariableForwardDeclaration(const VarDecl *VD);
384 
385   /// Return a global variable that represents one of the collection of
386   /// global variables created for an anonmyous union.
387   llvm::DIGlobalVariable
388   CollectAnonRecordDecls(const RecordDecl *RD, llvm::DIFile Unit, unsigned LineNo,
389                          StringRef LinkageName, llvm::GlobalVariable *Var,
390                          llvm::DIDescriptor DContext);
391 
392   /// getFunctionName - Get function name for the given FunctionDecl. If the
393   /// name is constructed on demand (e.g. C++ destructor) then the name
394   /// is stored on the side.
395   StringRef getFunctionName(const FunctionDecl *FD);
396 
397   /// getObjCMethodName - Returns the unmangled name of an Objective-C method.
398   /// This is the display name for the debugging info.
399   StringRef getObjCMethodName(const ObjCMethodDecl *FD);
400 
401   /// getSelectorName - Return selector name. This is used for debugging
402   /// info.
403   StringRef getSelectorName(Selector S);
404 
405   /// getClassName - Get class name including template argument list.
406   StringRef getClassName(const RecordDecl *RD);
407 
408   /// getVTableName - Get vtable name for the given Class.
409   StringRef getVTableName(const CXXRecordDecl *Decl);
410 
411   /// getLineNumber - Get line number for the location. If location is invalid
412   /// then use current location.
413   unsigned getLineNumber(SourceLocation Loc);
414 
415   /// getColumnNumber - Get column number for the location. If location is
416   /// invalid then use current location.
417   /// \param Force  Assume DebugColumnInfo option is true.
418   unsigned getColumnNumber(SourceLocation Loc, bool Force=false);
419 
420   /// \brief Collect various properties of a FunctionDecl.
421   /// \param GD  A GlobalDecl whose getDecl() must return a FunctionDecl.
422   void collectFunctionDeclProps(GlobalDecl GD,
423                                 llvm::DIFile Unit,
424                                 StringRef &Name, StringRef &LinkageName,
425                                 llvm::DIDescriptor &FDContext,
426                                 llvm::DIArray &TParamsArray,
427                                 unsigned &Flags);
428 
429   /// \brief Collect various properties of a VarDecl.
430   void collectVarDeclProps(const VarDecl *VD, llvm::DIFile &Unit,
431                            unsigned &LineNo, QualType &T,
432                            StringRef &Name, StringRef &LinkageName,
433                            llvm::DIDescriptor &VDContext);
434 
435   /// internString - Allocate a copy of \p A using the DebugInfoNames allocator
436   /// and return a reference to it. If multiple arguments are given the strings
437   /// are concatenated.
438   StringRef internString(StringRef A, StringRef B = StringRef()) {
439     char *Data = DebugInfoNames.Allocate<char>(A.size() + B.size());
440     std::memcpy(Data, A.data(), A.size());
441     std::memcpy(Data + A.size(), B.data(), B.size());
442     return StringRef(Data, A.size() + B.size());
443   }
444 };
445 
446 class ApplyDebugLocation {
447 protected:
448   llvm::DebugLoc OriginalLocation;
449   CodeGenFunction &CGF;
450 
451 public:
452   ApplyDebugLocation(CodeGenFunction &CGF,
453                      SourceLocation TemporaryLocation = SourceLocation());
454   ApplyDebugLocation(CodeGenFunction &CGF, llvm::DebugLoc Loc);
455   ~ApplyDebugLocation();
456 };
457 
458 /// ArtificialLocation - An RAII object that temporarily switches to
459 /// an artificial debug location that has a valid scope, but no line
460 /// information. This is useful when emitting compiler-generated
461 /// helper functions that have no source location associated with
462 /// them. The DWARF specification allows the compiler to use the
463 /// special line number 0 to indicate code that can not be attributed
464 /// to any source location.
465 ///
466 /// This is necessary because passing an empty SourceLocation to
467 /// CGDebugInfo::setLocation() will result in the last valid location
468 /// being reused.
469 class ArtificialLocation : public ApplyDebugLocation {
470 public:
471   ArtificialLocation(CodeGenFunction &CGF);
472 };
473 
474 
475 } // namespace CodeGen
476 } // namespace clang
477 
478 
479 #endif
480