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 {
19class Error;
20
21namespace DWARFYAML {
22
23struct Data;
24struct Unit;
25struct Entry;
26struct FormValue;
27struct 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.
33template <typename T> class VisitorImpl {
34protected:
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
67public:
68  VisitorImpl(T &DI) : DebugInfo(DI) {}
69
70  virtual ~VisitorImpl() {}
71
72  Error traverseDebugInfo();
73
74private:
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.
81extern template class VisitorImpl<DWARFYAML::Data>;
82extern template class VisitorImpl<const DWARFYAML::Data>;
83
84class Visitor : public VisitorImpl<Data> {
85public:
86  Visitor(Data &DI) : VisitorImpl<Data>(DI) {}
87};
88
89class ConstVisitor : public VisitorImpl<const Data> {
90public:
91  ConstVisitor(const Data &DI) : VisitorImpl<const Data>(DI) {}
92};
93
94} // namespace DWARFYAML
95} // namespace llvm
96
97#endif
98