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
75 const DWARFDataExtractor &getData() { return Data; }
76
77protected:
78 DWARFDataExtractor Data;
79
80 virtual void dumpRawEntry(const DWARFLocationEntry &Entry, raw_ostream &OS,
81 unsigned Indent, DIDumpOptions DumpOpts,
82 const DWARFObject &Obj) const = 0;
83};
84
85class DWARFDebugLoc final : public DWARFLocationTable {
86public:
87 /// A list of locations that contain one variable.
88 struct LocationList {
89 /// The beginning offset where this location list is stored in the debug_loc
90 /// section.
91 uint64_t Offset;
92 /// All the locations in which the variable is stored.
93 SmallVector<DWARFLocationEntry, 2> Entries;
94 };
95
96private:
97 using LocationLists = SmallVector<LocationList, 4>;
98
99 /// A list of all the variables in the debug_loc section, each one describing
100 /// the locations in which the variable is stored.
101 LocationLists Locations;
102
103public:
104 DWARFDebugLoc(DWARFDataExtractor Data)
105 : DWARFLocationTable(std::move(Data)) {}
106
107 /// Print the location lists found within the debug_loc section.
108 void dump(raw_ostream &OS, const MCRegisterInfo *RegInfo,
109 const DWARFObject &Obj, DIDumpOptions DumpOpts,
110 Optional<uint64_t> Offset) const;
111
112 Error visitLocationList(
113 uint64_t *Offset,
114 function_ref<bool(const DWARFLocationEntry &)> Callback) const override;
115
116protected:
117 void dumpRawEntry(const DWARFLocationEntry &Entry, raw_ostream &OS,
118 unsigned Indent, DIDumpOptions DumpOpts,
119 const DWARFObject &Obj) const override;
120};
121
122class DWARFDebugLoclists final : public DWARFLocationTable {
123public:
124 DWARFDebugLoclists(DWARFDataExtractor Data, uint16_t Version)
125 : DWARFLocationTable(std::move(Data)), Version(Version) {}
126
127 Error visitLocationList(
128 uint64_t *Offset,
129 function_ref<bool(const DWARFLocationEntry &)> Callback) const override;
130
131 /// Dump all location lists within the given range.
132 void dumpRange(uint64_t StartOffset, uint64_t Size, raw_ostream &OS,
133 const MCRegisterInfo *MRI, const DWARFObject &Obj,
134 DIDumpOptions DumpOpts);
135
136protected:
137 void dumpRawEntry(const DWARFLocationEntry &Entry, raw_ostream &OS,
138 unsigned Indent, DIDumpOptions DumpOpts,
139 const DWARFObject &Obj) const override;
140
141private:
142 uint16_t Version;
143};
144
145} // end namespace llvm
146
147#endif // LLVM_DEBUGINFO_DWARF_DWARFDEBUGLOC_H
148