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