lib/ObjectYAML/DWARFVisitor.h

   1 //===--- DWARFVisitor.h -----------------------------------------*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 //===----------------------------------------------------------------------===//
  10
  11 #ifndef LLVM_OBJECTYAML_DWARFVISITOR_H
  12 #define LLVM_OBJECTYAML_DWARFVISITOR_H
  13
  14 #include "llvm/ADT/StringRef.h"
  15 #include "llvm/BinaryFormat/Dwarf.h"
  16 #include "llvm/Support/MemoryBuffer.h"
  17
  18 namespace llvm {
  19
  20 namespace DWARFYAML {
  21
  22 struct Data;
  23 struct Unit;
  24 struct Entry;
  25 struct FormValue;
  26 struct AttributeAbbrev;
  27
  28 /// A class to visits DWARFYAML Compile Units and DIEs in preorder.
  29 ///
  30 /// Extensions of this class can either maintain const or non-const references
  31 /// to the DWARFYAML::Data object.
  32 template <typename T> class VisitorImpl {
  33 protected:
  34   T &DebugInfo;
  35
  36   /// Visitor Functions
  37   /// @{
  38   virtual void onStartCompileUnit(Unit &CU) {}
  39   virtual void onEndCompileUnit(Unit &CU) {}
  40   virtual void onStartDIE(Unit &CU, Entry &DIE) {}
  41   virtual void onEndDIE(Unit &CU, Entry &DIE) {}
  42   virtual void onForm(AttributeAbbrev &AttAbbrev, FormValue &Value) {}
  43   /// @}
  44
  45   /// Const Visitor Functions
  46   /// @{
  47   virtual void onStartCompileUnit(const Unit &CU) {}
  48   virtual void onEndCompileUnit(const Unit &CU) {}
  49   virtual void onStartDIE(const Unit &CU, const Entry &DIE) {}
  50   virtual void onEndDIE(const Unit &CU, const Entry &DIE) {}
  51   virtual void onForm(const AttributeAbbrev &AttAbbrev,
  52                       const FormValue &Value) {}
  53   /// @}
  54
  55   /// Value visitors
  56   /// @{
  57   virtual void onValue(const uint8_t U) {}
  58   virtual void onValue(const uint16_t U) {}
  59   virtual void onValue(const uint32_t U) {}
  60   virtual void onValue(const uint64_t U, const bool LEB = false) {}
  61   virtual void onValue(const int64_t S, const bool LEB = false) {}
  62   virtual void onValue(const StringRef String) {}
  63   virtual void onValue(const MemoryBufferRef MBR) {}
  64   /// @}
  65
  66 public:
  67   VisitorImpl(T &DI) : DebugInfo(DI) {}
  68
  69   virtual ~VisitorImpl() {}
  70
  71   void traverseDebugInfo();
  72
  73 private:
  74   void onVariableSizeValue(uint64_t U, unsigned Size);
  75 };
  76
  77 // Making the visior instantiations extern and explicit in the cpp file. This
  78 // prevents them from being instantiated in every compile unit that uses the
  79 // visitors.
  80 extern template class VisitorImpl<DWARFYAML::Data>;
  81 extern template class VisitorImpl<const DWARFYAML::Data>;
  82
  83 class Visitor : public VisitorImpl<Data> {
  84 public:
  85   Visitor(Data &DI) : VisitorImpl<Data>(DI) {}
  86 };
  87
  88 class ConstVisitor : public VisitorImpl<const Data> {
  89 public:
  90   ConstVisitor(const Data &DI) : VisitorImpl<const Data>(DI) {}
  91 };
  92
  93 } // namespace DWARFYAML
  94 } // namespace llvm
  95
  96 #endif