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UnwindTable.cpp
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1//===-- UnwindTable.cpp ---------------------------------------------------===//
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
10
11#include <cstdio>
12#include <optional>
13
14#include "lldb/Core/Module.h"
15#include "lldb/Core/Section.h"
24
25// There is one UnwindTable object per ObjectFile. It contains a list of Unwind
26// objects -- one per function, populated lazily -- for the ObjectFile. Each
27// Unwind object has multiple UnwindPlans for different scenarios.
28
29using namespace lldb;
30using namespace lldb_private;
31
33 : m_module(module), m_unwinds(), m_initialized(false), m_mutex(),
34 m_object_file_unwind_up(), m_eh_frame_up(), m_compact_unwind_up(),
35 m_arm_unwind_up() {}
36
37// We can't do some of this initialization when the ObjectFile is running its
38// ctor; delay doing it until needed for something.
39
41 if (m_initialized)
42 return;
43
44 std::lock_guard<std::mutex> guard(m_mutex);
45
46 if (m_initialized) // check again once we've acquired the lock
47 return;
48 m_initialized = true;
49 ObjectFile *object_file = m_module.GetObjectFile();
50 if (!object_file)
51 return;
52
54
56 if (!sl)
57 return;
58
59 SectionSP sect = sl->FindSectionByType(eSectionTypeEHFrame, true);
60 if (sect.get()) {
61 m_eh_frame_up = std::make_unique<DWARFCallFrameInfo>(
62 *object_file, sect, DWARFCallFrameInfo::EH);
63 }
64
66 if (sect) {
67 m_debug_frame_up = std::make_unique<DWARFCallFrameInfo>(
68 *object_file, sect, DWARFCallFrameInfo::DWARF);
69 }
70
72 if (sect) {
74 std::make_unique<CompactUnwindInfo>(*object_file, sect);
75 }
76
78 if (sect) {
79 SectionSP sect_extab = sl->FindSectionByType(eSectionTypeARMextab, true);
80 if (sect_extab.get()) {
82 std::make_unique<ArmUnwindInfo>(*object_file, sect, sect_extab);
83 }
84 }
85}
86
88
89std::optional<AddressRange>
91 AddressRange range;
92
93 // First check the unwind info from the object file plugin
95 m_object_file_unwind_up->GetAddressRange(addr, range))
96 return range;
97
98 // Check the symbol context
99 if (sc.GetAddressRange(eSymbolContextFunction | eSymbolContextSymbol, 0,
100 false, range) &&
101 range.GetBaseAddress().IsValid())
102 return range;
103
104 // Does the eh_frame unwind info has a function bounds for this addr?
105 if (m_eh_frame_up && m_eh_frame_up->GetAddressRange(addr, range))
106 return range;
107
108 // Try debug_frame as well
109 if (m_debug_frame_up && m_debug_frame_up->GetAddressRange(addr, range))
110 return range;
111
112 return std::nullopt;
113}
114
115FuncUnwindersSP
117 SymbolContext &sc) {
118 Initialize();
119
120 std::lock_guard<std::mutex> guard(m_mutex);
121
122 // There is an UnwindTable per object file, so we can safely use file handles
123 addr_t file_addr = addr.GetFileAddress();
124 iterator end = m_unwinds.end();
125 iterator insert_pos = end;
126 if (!m_unwinds.empty()) {
127 insert_pos = m_unwinds.lower_bound(file_addr);
128 iterator pos = insert_pos;
129 if ((pos == m_unwinds.end()) ||
130 (pos != m_unwinds.begin() &&
131 pos->second->GetFunctionStartAddress() != addr))
132 --pos;
133
134 if (pos->second->ContainsAddress(addr))
135 return pos->second;
136 }
137
138 auto range_or = GetAddressRange(addr, sc);
139 if (!range_or)
140 return nullptr;
141
142 FuncUnwindersSP func_unwinder_sp(new FuncUnwinders(*this, *range_or));
143 m_unwinds.insert(insert_pos,
144 std::make_pair(range_or->GetBaseAddress().GetFileAddress(),
145 func_unwinder_sp));
146 return func_unwinder_sp;
147}
148
149// Ignore any existing FuncUnwinders for this function, create a new one and
150// don't add it to the UnwindTable. This is intended for use by target modules
151// show-unwind where we want to create new UnwindPlans, not re-use existing
152// ones.
154 const Address &addr, const SymbolContext &sc) {
155 Initialize();
156
157 auto range_or = GetAddressRange(addr, sc);
158 if (!range_or)
159 return nullptr;
160
161 return std::make_shared<FuncUnwinders>(*this, *range_or);
162}
163
165 std::lock_guard<std::mutex> guard(m_mutex);
166 s.Format("UnwindTable for '{0}':\n", m_module.GetFileSpec());
167 const_iterator begin = m_unwinds.begin();
168 const_iterator end = m_unwinds.end();
169 for (const_iterator pos = begin; pos != end; ++pos) {
170 s.Printf("[%u] 0x%16.16" PRIx64 "\n", (unsigned)std::distance(begin, pos),
171 pos->first);
172 }
173 s.EOL();
174}
175
177 Initialize();
178 return m_object_file_unwind_up.get();
179}
180
182 Initialize();
183 return m_eh_frame_up.get();
184}
185
187 Initialize();
188 return m_debug_frame_up.get();
189}
190
192 Initialize();
193 return m_compact_unwind_up.get();
194}
195
197 Initialize();
198 return m_arm_unwind_up.get();
199}
200
202
204
206 if (ObjectFile *object_file = m_module.GetObjectFile())
207 return object_file->AllowAssemblyEmulationUnwindPlans();
208 return false;
209}
A section + offset based address range class.
Definition: AddressRange.h:25
Address & GetBaseAddress()
Get accessor for the base address of the range.
Definition: AddressRange.h:209
A section + offset based address class.
Definition: Address.h:59
lldb::addr_t GetFileAddress() const
Get the file address.
Definition: Address.cpp:291
bool IsValid() const
Check if the object state is valid.
Definition: Address.h:345
An architecture specification class.
Definition: ArchSpec.h:31
A class that describes an executable image and its associated object and symbol files.
Definition: Module.h:88
virtual ObjectFile * GetObjectFile()
Get the object file representation for the current architecture.
Definition: Module.cpp:1230
virtual SymbolFile * GetSymbolFile(bool can_create=true, Stream *feedback_strm=nullptr)
Get the module's symbol file.
Definition: Module.cpp:1050
const ArchSpec & GetArchitecture() const
Get const accessor for the module architecture.
Definition: Module.cpp:1081
virtual SectionList * GetSectionList()
Get the unified section list for the module.
Definition: Module.cpp:1269
const FileSpec & GetFileSpec() const
Get const accessor for the module file specification.
Definition: Module.h:498
A plug-in interface definition class for object file parsers.
Definition: ObjectFile.h:43
virtual std::unique_ptr< CallFrameInfo > CreateCallFrameInfo()
Creates a plugin-specific call frame info.
Definition: ObjectFile.cpp:651
lldb::SectionSP FindSectionByType(lldb::SectionType sect_type, bool check_children, size_t start_idx=0) const
Definition: Section.cpp:586
A stream class that can stream formatted output to a file.
Definition: Stream.h:28
void Format(const char *format, Args &&... args)
Definition: Stream.h:309
size_t Printf(const char *format,...) __attribute__((format(printf
Output printf formatted output to the stream.
Definition: Stream.cpp:107
size_t EOL()
Output and End of Line character to the stream.
Definition: Stream.cpp:128
Defines a symbol context baton that can be handed other debug core functions.
Definition: SymbolContext.h:33
bool GetAddressRange(uint32_t scope, uint32_t range_idx, bool use_inline_block_range, AddressRange &range) const
Get the address range contained within a symbol context.
Provides public interface for all SymbolFiles.
Definition: SymbolFile.h:49
std::optional< AddressRange > GetAddressRange(const Address &addr, const SymbolContext &sc)
Definition: UnwindTable.cpp:90
lldb_private::DWARFCallFrameInfo * GetEHFrameInfo()
std::unique_ptr< DWARFCallFrameInfo > m_debug_frame_up
Definition: UnwindTable.h:79
std::unique_ptr< CallFrameInfo > m_object_file_unwind_up
Definition: UnwindTable.h:77
bool GetAllowAssemblyEmulationUnwindPlans()
ArmUnwindInfo * GetArmUnwindInfo()
std::unique_ptr< DWARFCallFrameInfo > m_eh_frame_up
Definition: UnwindTable.h:78
UnwindTable(Module &module)
Create an Unwind table using the data in the given module.
Definition: UnwindTable.cpp:32
std::unique_ptr< CompactUnwindInfo > m_compact_unwind_up
Definition: UnwindTable.h:80
SymbolFile * GetSymbolFile()
collection::const_iterator const_iterator
Definition: UnwindTable.h:69
lldb::FuncUnwindersSP GetFuncUnwindersContainingAddress(const Address &addr, SymbolContext &sc)
lldb_private::DWARFCallFrameInfo * GetDebugFrameInfo()
lldb::FuncUnwindersSP GetUncachedFuncUnwindersContainingAddress(const Address &addr, const SymbolContext &sc)
lldb_private::CompactUnwindInfo * GetCompactUnwindInfo()
lldb_private::CallFrameInfo * GetObjectFileUnwindInfo()
collection::iterator iterator
Definition: UnwindTable.h:68
std::unique_ptr< ArmUnwindInfo > m_arm_unwind_up
Definition: UnwindTable.h:81
A class that represents a running process on the host machine.
Definition: SBAttachInfo.h:14
Definition: SBAddress.h:15
uint64_t addr_t
Definition: lldb-types.h:79
@ eSectionTypeDWARFDebugFrame
@ eSectionTypeARMextab
@ eSectionTypeCompactUnwind
compact unwind section in Mach-O, __TEXT,__unwind_info
@ eSectionTypeEHFrame
@ eSectionTypeARMexidx