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
18namespace llvm {
19
20namespace DWARFYAML {
21
22struct Data;
23struct Unit;
24struct Entry;
25struct FormValue;
26struct 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.
32template <typename T> class VisitorImpl {
33protected:
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
66public:
67  VisitorImpl(T &DI) : DebugInfo(DI) {}
68
69  virtual ~VisitorImpl() {}
70
71  void traverseDebugInfo();
72
73private:
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.
80extern template class VisitorImpl<DWARFYAML::Data>;
81extern template class VisitorImpl<const DWARFYAML::Data>;
82
83class Visitor : public VisitorImpl<Data> {
84public:
85  Visitor(Data &DI) : VisitorImpl<Data>(DI) {}
86};
87
88class ConstVisitor : public VisitorImpl<const Data> {
89public:
90  ConstVisitor(const Data &DI) : VisitorImpl<const Data>(DI) {}
91};
92
93} // namespace DWARFYAML
94} // namespace llvm
95
96#endif
97