lib/ObjectYAML/DWARFVisitor.h

   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   /// @{
  39   virtual void onStartCompileUnit(Unit &CU) {}
  40   virtual void onEndCompileUnit(Unit &CU) {}
  41   virtual void onStartDIE(Unit &CU, Entry &DIE) {}
  42   virtual void onEndDIE(Unit &CU, Entry &DIE) {}
  43   virtual void onForm(AttributeAbbrev &AttAbbrev, FormValue &Value) {}
  44   /// @}
  45
  46   /// Const Visitor Functions
  47   /// @{
  48   virtual void onStartCompileUnit(const Unit &CU) {}
  49   virtual void onEndCompileUnit(const Unit &CU) {}
  50   virtual void onStartDIE(const Unit &CU, const Entry &DIE) {}
  51   virtual void onEndDIE(const Unit &CU, const Entry &DIE) {}
  52   virtual void onForm(const AttributeAbbrev &AttAbbrev,
  53                       const FormValue &Value) {}
  54   /// @}
  55
  56   /// Value visitors
  57   /// @{
  58   virtual void onValue(const uint8_t U) {}
  59   virtual void onValue(const uint16_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) {}
  63   virtual void onValue(const StringRef String) {}
  64   virtual void onValue(const MemoryBufferRef MBR) {}
  65   /// @}
  66
  67 public:
  68   VisitorImpl(T &DI) : DebugInfo(DI) {}
  69
  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:
  86   Visitor(Data &DI) : VisitorImpl<Data>(DI) {}
  87 };
  88
  89 class ConstVisitor : public VisitorImpl<const Data> {
  90 public:
  91   ConstVisitor(const Data &DI) : VisitorImpl<const Data>(DI) {}
  92 };
  93
  94 } // namespace DWARFYAML
  95 } // namespace llvm
  96
  97 #endif