1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
| //===-- UnwindTable.cpp -----------------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "lldb/Symbol/UnwindTable.h"
#include <stdio.h>
#include "lldb/Core/Module.h"
#include "lldb/Core/Section.h"
#include "lldb/Symbol/ArmUnwindInfo.h"
#include "lldb/Symbol/CallFrameInfo.h"
#include "lldb/Symbol/CompactUnwindInfo.h"
#include "lldb/Symbol/DWARFCallFrameInfo.h"
#include "lldb/Symbol/FuncUnwinders.h"
#include "lldb/Symbol/ObjectFile.h"
#include "lldb/Symbol/SymbolContext.h"
#include "lldb/Symbol/SymbolVendor.h"
// There is one UnwindTable object per ObjectFile. It contains a list of Unwind
// objects -- one per function, populated lazily -- for the ObjectFile. Each
// Unwind object has multiple UnwindPlans for different scenarios.
using namespace lldb;
using namespace lldb_private;
UnwindTable::UnwindTable(Module &module)
: m_module(module), m_unwinds(), m_initialized(false), m_mutex(),
m_object_file_unwind_up(), m_eh_frame_up(), m_compact_unwind_up(),
m_arm_unwind_up() {}
// We can't do some of this initialization when the ObjectFile is running its
// ctor; delay doing it until needed for something.
void UnwindTable::Initialize() {
if (m_initialized)
return;
std::lock_guard<std::mutex> guard(m_mutex);
if (m_initialized) // check again once we've acquired the lock
return;
m_initialized = true;
ObjectFile *object_file = m_module.GetObjectFile();
if (!object_file)
return;
m_object_file_unwind_up = object_file->CreateCallFrameInfo();
SectionList *sl = m_module.GetSectionList();
if (!sl)
return;
SectionSP sect = sl->FindSectionByType(eSectionTypeEHFrame, true);
if (sect.get()) {
m_eh_frame_up.reset(
new DWARFCallFrameInfo(*object_file, sect, DWARFCallFrameInfo::EH));
}
sect = sl->FindSectionByType(eSectionTypeDWARFDebugFrame, true);
if (sect) {
m_debug_frame_up.reset(
new DWARFCallFrameInfo(*object_file, sect, DWARFCallFrameInfo::DWARF));
}
sect = sl->FindSectionByType(eSectionTypeCompactUnwind, true);
if (sect) {
m_compact_unwind_up.reset(new CompactUnwindInfo(*object_file, sect));
}
sect = sl->FindSectionByType(eSectionTypeARMexidx, true);
if (sect) {
SectionSP sect_extab = sl->FindSectionByType(eSectionTypeARMextab, true);
if (sect_extab.get()) {
m_arm_unwind_up.reset(new ArmUnwindInfo(*object_file, sect, sect_extab));
}
}
}
UnwindTable::~UnwindTable() {}
llvm::Optional<AddressRange> UnwindTable::GetAddressRange(const Address &addr,
SymbolContext &sc) {
AddressRange range;
// First check the unwind info from the object file plugin
if (m_object_file_unwind_up &&
m_object_file_unwind_up->GetAddressRange(addr, range))
return range;
// Check the symbol context
if (sc.GetAddressRange(eSymbolContextFunction | eSymbolContextSymbol, 0,
false, range) &&
range.GetBaseAddress().IsValid())
return range;
// Does the eh_frame unwind info has a function bounds for this addr?
if (m_eh_frame_up && m_eh_frame_up->GetAddressRange(addr, range))
return range;
// Try debug_frame as well
if (m_debug_frame_up && m_debug_frame_up->GetAddressRange(addr, range))
return range;
return llvm::None;
}
FuncUnwindersSP
UnwindTable::GetFuncUnwindersContainingAddress(const Address &addr,
SymbolContext &sc) {
Initialize();
std::lock_guard<std::mutex> guard(m_mutex);
// There is an UnwindTable per object file, so we can safely use file handles
addr_t file_addr = addr.GetFileAddress();
iterator end = m_unwinds.end();
iterator insert_pos = end;
if (!m_unwinds.empty()) {
insert_pos = m_unwinds.lower_bound(file_addr);
iterator pos = insert_pos;
if ((pos == m_unwinds.end()) ||
(pos != m_unwinds.begin() &&
pos->second->GetFunctionStartAddress() != addr))
--pos;
if (pos->second->ContainsAddress(addr))
return pos->second;
}
auto range_or = GetAddressRange(addr, sc);
if (!range_or)
return nullptr;
FuncUnwindersSP func_unwinder_sp(new FuncUnwinders(*this, *range_or));
m_unwinds.insert(insert_pos,
std::make_pair(range_or->GetBaseAddress().GetFileAddress(),
func_unwinder_sp));
return func_unwinder_sp;
}
// Ignore any existing FuncUnwinders for this function, create a new one and
// don't add it to the UnwindTable. This is intended for use by target modules
// show-unwind where we want to create new UnwindPlans, not re-use existing
// ones.
FuncUnwindersSP
UnwindTable::GetUncachedFuncUnwindersContainingAddress(const Address &addr,
SymbolContext &sc) {
Initialize();
auto range_or = GetAddressRange(addr, sc);
if (!range_or)
return nullptr;
return std::make_shared<FuncUnwinders>(*this, *range_or);
}
void UnwindTable::Dump(Stream &s) {
std::lock_guard<std::mutex> guard(m_mutex);
s.Format("UnwindTable for '{0}':\n", m_module.GetFileSpec());
const_iterator begin = m_unwinds.begin();
const_iterator end = m_unwinds.end();
for (const_iterator pos = begin; pos != end; ++pos) {
s.Printf("[%u] 0x%16.16" PRIx64 "\n", (unsigned)std::distance(begin, pos),
pos->first);
}
s.EOL();
}
lldb_private::CallFrameInfo *UnwindTable::GetObjectFileUnwindInfo() {
Initialize();
return m_object_file_unwind_up.get();
}
DWARFCallFrameInfo *UnwindTable::GetEHFrameInfo() {
Initialize();
return m_eh_frame_up.get();
}
DWARFCallFrameInfo *UnwindTable::GetDebugFrameInfo() {
Initialize();
return m_debug_frame_up.get();
}
CompactUnwindInfo *UnwindTable::GetCompactUnwindInfo() {
Initialize();
return m_compact_unwind_up.get();
}
ArmUnwindInfo *UnwindTable::GetArmUnwindInfo() {
Initialize();
return m_arm_unwind_up.get();
}
SymbolFile *UnwindTable::GetSymbolFile() { return m_module.GetSymbolFile(); }
ArchSpec UnwindTable::GetArchitecture() { return m_module.GetArchitecture(); }
bool UnwindTable::GetAllowAssemblyEmulationUnwindPlans() {
if (ObjectFile *object_file = m_module.GetObjectFile())
return object_file->AllowAssemblyEmulationUnwindPlans();
return false;
}
|