1 //===--- DWARFVisitor.h -----------------------------------------*- 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 //===----------------------------------------------------------------------===//
11 
12 #ifndef LLVM_OBJECTYAML_DWARFVISITOR_H
13 #define LLVM_OBJECTYAML_DWARFVISITOR_H
14 
15 #include "llvm/ADT/StringRef.h"
16 #include "llvm/BinaryFormat/Dwarf.h"
17 #include "llvm/Support/MemoryBuffer.h"
18 
19 namespace llvm {
20 
21 namespace DWARFYAML {
22 
23 struct Data;
24 struct Unit;
25 struct Entry;
26 struct FormValue;
27 struct AttributeAbbrev;
28 
29 /// A class to visits DWARFYAML Compile Units and DIEs in preorder.
30 ///
31 /// Extensions of this class can either maintain const or non-const references
32 /// to the DWARFYAML::Data object.
33 template <typename T> class VisitorImpl {
34 protected:
35   T &DebugInfo;
36 
37   /// Visitor Functions
38   /// @{
onStartCompileUnit(Unit & CU)39   virtual void onStartCompileUnit(Unit &CU) {}
onEndCompileUnit(Unit & CU)40   virtual void onEndCompileUnit(Unit &CU) {}
onStartDIE(Unit & CU,Entry & DIE)41   virtual void onStartDIE(Unit &CU, Entry &DIE) {}
onEndDIE(Unit & CU,Entry & DIE)42   virtual void onEndDIE(Unit &CU, Entry &DIE) {}
onForm(AttributeAbbrev & AttAbbrev,FormValue & Value)43   virtual void onForm(AttributeAbbrev &AttAbbrev, FormValue &Value) {}
44   /// @}
45 
46   /// Const Visitor Functions
47   /// @{
onStartCompileUnit(const Unit & CU)48   virtual void onStartCompileUnit(const Unit &CU) {}
onEndCompileUnit(const Unit & CU)49   virtual void onEndCompileUnit(const Unit &CU) {}
onStartDIE(const Unit & CU,const Entry & DIE)50   virtual void onStartDIE(const Unit &CU, const Entry &DIE) {}
onEndDIE(const Unit & CU,const Entry & DIE)51   virtual void onEndDIE(const Unit &CU, const Entry &DIE) {}
onForm(const AttributeAbbrev & AttAbbrev,const FormValue & Value)52   virtual void onForm(const AttributeAbbrev &AttAbbrev,
53                       const FormValue &Value) {}
54   /// @}
55 
56   /// Value visitors
57   /// @{
onValue(const uint8_t U)58   virtual void onValue(const uint8_t U) {}
onValue(const uint16_t U)59   virtual void onValue(const uint16_t U) {}
onValue(const uint32_t U)60   virtual void onValue(const uint32_t U) {}
61   virtual void onValue(const uint64_t U, const bool LEB = false) {}
62   virtual void onValue(const int64_t S, const bool LEB = false) {}
onValue(const StringRef String)63   virtual void onValue(const StringRef String) {}
onValue(const MemoryBufferRef MBR)64   virtual void onValue(const MemoryBufferRef MBR) {}
65   /// @}
66 
67 public:
VisitorImpl(T & DI)68   VisitorImpl(T &DI) : DebugInfo(DI) {}
69 
~VisitorImpl()70   virtual ~VisitorImpl() {}
71 
72   void traverseDebugInfo();
73 
74 private:
75   void onVariableSizeValue(uint64_t U, unsigned Size);
76 };
77 
78 // Making the visior instantiations extern and explicit in the cpp file. This
79 // prevents them from being instantiated in every compile unit that uses the
80 // visitors.
81 extern template class VisitorImpl<DWARFYAML::Data>;
82 extern template class VisitorImpl<const DWARFYAML::Data>;
83 
84 class Visitor : public VisitorImpl<Data> {
85 public:
Visitor(Data & DI)86   Visitor(Data &DI) : VisitorImpl<Data>(DI) {}
87 };
88 
89 class ConstVisitor : public VisitorImpl<const Data> {
90 public:
ConstVisitor(const Data & DI)91   ConstVisitor(const Data &DI) : VisitorImpl<const Data>(DI) {}
92 };
93 
94 } // namespace DWARFYAML
95 } // namespace llvm
96 
97 #endif
98