DWARFDebugLoc.h revision 360784 
1//===- DWARFDebugLoc.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#ifndef LLVM_DEBUGINFO_DWARF_DWARFDEBUGLOC_H
10#define LLVM_DEBUGINFO_DWARF_DWARFDEBUGLOC_H
11
12#include "llvm/ADT/Optional.h"
13#include "llvm/ADT/SmallVector.h"
14#include "llvm/DebugInfo/DIContext.h"
15#include "llvm/DebugInfo/DWARF/DWARFDataExtractor.h"
16#include "llvm/DebugInfo/DWARF/DWARFLocationExpression.h"
17#include "llvm/DebugInfo/DWARF/DWARFRelocMap.h"
18#include <cstdint>
19
20namespace llvm {
21class DWARFUnit;
22class MCRegisterInfo;
23class raw_ostream;
24
25/// A single location within a location list. Entries are stored in the DWARF5
26/// form even if they originally come from a DWARF<=4 location list.
27struct DWARFLocationEntry {
28  /// The entry kind (DW_LLE_***).
29  uint8_t Kind;
30
31  /// The first value of the location entry (if applicable).
32  uint64_t Value0;
33
34  /// The second value of the location entry (if applicable).
35  uint64_t Value1;
36
37  /// The index of the section this entry is relative to (if applicable).
38  uint64_t SectionIndex;
39
40  /// The location expression itself (if applicable).
41  SmallVector<uint8_t, 4> Loc;
42};
43
44/// An abstract base class for various kinds of location tables (.debug_loc,
45/// .debug_loclists, and their dwo variants).
46class DWARFLocationTable {
47public:
48  DWARFLocationTable(DWARFDataExtractor Data) : Data(std::move(Data)) {}
49  virtual ~DWARFLocationTable() = default;
50
51  /// Call the user-provided callback for each entry (including the end-of-list
52  /// entry) in the location list starting at \p Offset. The callback can return
53  /// false to terminate the iteration early. Returns an error if it was unable
54  /// to parse the entire location list correctly. Upon successful termination
55  /// \p Offset will be updated point past the end of the list.
56  virtual Error visitLocationList(
57      uint64_t *Offset,
58      function_ref<bool(const DWARFLocationEntry &)> Callback) const = 0;
59
60  /// Dump the location list at the given \p Offset. The function returns true
61  /// iff it has successfully reched the end of the list. This means that one
62  /// can attempt to parse another list after the current one (\p Offset will be
63  /// updated to point past the end of the current list).
64  bool dumpLocationList(uint64_t *Offset, raw_ostream &OS,
65                        Optional<object::SectionedAddress> BaseAddr,
66                        const MCRegisterInfo *MRI, const DWARFObject &Obj,
67                        DWARFUnit *U, DIDumpOptions DumpOpts,
68                        unsigned Indent) const;
69
70  Error visitAbsoluteLocationList(
71      uint64_t Offset, Optional<object::SectionedAddress> BaseAddr,
72      std::function<Optional<object::SectionedAddress>(uint32_t)> LookupAddr,
73      function_ref<bool(Expected<DWARFLocationExpression>)> Callback) const;
74
75protected:
76  DWARFDataExtractor Data;
77
78  virtual void dumpRawEntry(const DWARFLocationEntry &Entry, raw_ostream &OS,
79                            unsigned Indent, DIDumpOptions DumpOpts,
80                            const DWARFObject &Obj) const = 0;
81};
82
83class DWARFDebugLoc final : public DWARFLocationTable {
84public:
85  /// A list of locations that contain one variable.
86  struct LocationList {
87    /// The beginning offset where this location list is stored in the debug_loc
88    /// section.
89    uint64_t Offset;
90    /// All the locations in which the variable is stored.
91    SmallVector<DWARFLocationEntry, 2> Entries;
92  };
93
94private:
95  using LocationLists = SmallVector<LocationList, 4>;
96
97  /// A list of all the variables in the debug_loc section, each one describing
98  /// the locations in which the variable is stored.
99  LocationLists Locations;
100
101public:
102  DWARFDebugLoc(DWARFDataExtractor Data)
103      : DWARFLocationTable(std::move(Data)) {}
104
105  /// Print the location lists found within the debug_loc section.
106  void dump(raw_ostream &OS, const MCRegisterInfo *RegInfo,
107            const DWARFObject &Obj, DIDumpOptions DumpOpts,
108            Optional<uint64_t> Offset) const;
109
110  Error visitLocationList(
111      uint64_t *Offset,
112      function_ref<bool(const DWARFLocationEntry &)> Callback) const override;
113
114protected:
115  void dumpRawEntry(const DWARFLocationEntry &Entry, raw_ostream &OS,
116                    unsigned Indent, DIDumpOptions DumpOpts,
117                    const DWARFObject &Obj) const override;
118};
119
120class DWARFDebugLoclists final : public DWARFLocationTable {
121public:
122  DWARFDebugLoclists(DWARFDataExtractor Data, uint16_t Version)
123      : DWARFLocationTable(std::move(Data)), Version(Version) {}
124
125  Error visitLocationList(
126      uint64_t *Offset,
127      function_ref<bool(const DWARFLocationEntry &)> Callback) const override;
128
129  /// Dump all location lists within the given range.
130  void dumpRange(uint64_t StartOffset, uint64_t Size, raw_ostream &OS,
131                 const MCRegisterInfo *MRI, const DWARFObject &Obj,
132                 DIDumpOptions DumpOpts);
133
134protected:
135  void dumpRawEntry(const DWARFLocationEntry &Entry, raw_ostream &OS,
136                    unsigned Indent, DIDumpOptions DumpOpts,
137                    const DWARFObject &Obj) const override;
138
139private:
140  uint16_t Version;
141};
142
143} // end namespace llvm
144
145#endif // LLVM_DEBUGINFO_DWARF_DWARFDEBUGLOC_H
146