1 //===-- UnwindTable.cpp -----------------------------------------*- 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 #include "lldb/Symbol/UnwindTable.h" 10 11 #include <stdio.h> 12 13 #include "lldb/Core/Module.h" 14 #include "lldb/Core/Section.h" 15 #include "lldb/Symbol/ArmUnwindInfo.h" 16 #include "lldb/Symbol/CallFrameInfo.h" 17 #include "lldb/Symbol/CompactUnwindInfo.h" 18 #include "lldb/Symbol/DWARFCallFrameInfo.h" 19 #include "lldb/Symbol/FuncUnwinders.h" 20 #include "lldb/Symbol/ObjectFile.h" 21 #include "lldb/Symbol/SymbolContext.h" 22 #include "lldb/Symbol/SymbolVendor.h" 23 24 // There is one UnwindTable object per ObjectFile. It contains a list of Unwind 25 // objects -- one per function, populated lazily -- for the ObjectFile. Each 26 // Unwind object has multiple UnwindPlans for different scenarios. 27 28 using namespace lldb; 29 using namespace lldb_private; 30 31 UnwindTable::UnwindTable(Module &module) 32 : m_module(module), m_unwinds(), m_initialized(false), m_mutex(), 33 m_object_file_unwind_up(), m_eh_frame_up(), m_compact_unwind_up(), 34 m_arm_unwind_up() {} 35 36 // We can't do some of this initialization when the ObjectFile is running its 37 // ctor; delay doing it until needed for something. 38 39 void UnwindTable::Initialize() { 40 if (m_initialized) 41 return; 42 43 std::lock_guard<std::mutex> guard(m_mutex); 44 45 if (m_initialized) // check again once we've acquired the lock 46 return; 47 m_initialized = true; 48 ObjectFile *object_file = m_module.GetObjectFile(); 49 if (!object_file) 50 return; 51 52 m_object_file_unwind_up = object_file->CreateCallFrameInfo(); 53 54 SectionList *sl = m_module.GetSectionList(); 55 if (!sl) 56 return; 57 58 SectionSP sect = sl->FindSectionByType(eSectionTypeEHFrame, true); 59 if (sect.get()) { 60 m_eh_frame_up.reset( 61 new DWARFCallFrameInfo(*object_file, sect, DWARFCallFrameInfo::EH)); 62 } 63 64 sect = sl->FindSectionByType(eSectionTypeDWARFDebugFrame, true); 65 if (sect) { 66 m_debug_frame_up.reset( 67 new DWARFCallFrameInfo(*object_file, sect, DWARFCallFrameInfo::DWARF)); 68 } 69 70 sect = sl->FindSectionByType(eSectionTypeCompactUnwind, true); 71 if (sect) { 72 m_compact_unwind_up.reset(new CompactUnwindInfo(*object_file, sect)); 73 } 74 75 sect = sl->FindSectionByType(eSectionTypeARMexidx, true); 76 if (sect) { 77 SectionSP sect_extab = sl->FindSectionByType(eSectionTypeARMextab, true); 78 if (sect_extab.get()) { 79 m_arm_unwind_up.reset(new ArmUnwindInfo(*object_file, sect, sect_extab)); 80 } 81 } 82 } 83 84 UnwindTable::~UnwindTable() {} 85 86 llvm::Optional<AddressRange> UnwindTable::GetAddressRange(const Address &addr, 87 SymbolContext &sc) { 88 AddressRange range; 89 90 // First check the unwind info from the object file plugin 91 if (m_object_file_unwind_up && 92 m_object_file_unwind_up->GetAddressRange(addr, range)) 93 return range; 94 95 // Check the symbol context 96 if (sc.GetAddressRange(eSymbolContextFunction | eSymbolContextSymbol, 0, 97 false, range) && 98 range.GetBaseAddress().IsValid()) 99 return range; 100 101 // Does the eh_frame unwind info has a function bounds for this addr? 102 if (m_eh_frame_up && m_eh_frame_up->GetAddressRange(addr, range)) 103 return range; 104 105 // Try debug_frame as well 106 if (m_debug_frame_up && m_debug_frame_up->GetAddressRange(addr, range)) 107 return range; 108 109 return llvm::None; 110 } 111 112 FuncUnwindersSP 113 UnwindTable::GetFuncUnwindersContainingAddress(const Address &addr, 114 SymbolContext &sc) { 115 Initialize(); 116 117 std::lock_guard<std::mutex> guard(m_mutex); 118 119 // There is an UnwindTable per object file, so we can safely use file handles 120 addr_t file_addr = addr.GetFileAddress(); 121 iterator end = m_unwinds.end(); 122 iterator insert_pos = end; 123 if (!m_unwinds.empty()) { 124 insert_pos = m_unwinds.lower_bound(file_addr); 125 iterator pos = insert_pos; 126 if ((pos == m_unwinds.end()) || 127 (pos != m_unwinds.begin() && 128 pos->second->GetFunctionStartAddress() != addr)) 129 --pos; 130 131 if (pos->second->ContainsAddress(addr)) 132 return pos->second; 133 } 134 135 auto range_or = GetAddressRange(addr, sc); 136 if (!range_or) 137 return nullptr; 138 139 FuncUnwindersSP func_unwinder_sp(new FuncUnwinders(*this, *range_or)); 140 m_unwinds.insert(insert_pos, 141 std::make_pair(range_or->GetBaseAddress().GetFileAddress(), 142 func_unwinder_sp)); 143 return func_unwinder_sp; 144 } 145 146 // Ignore any existing FuncUnwinders for this function, create a new one and 147 // don't add it to the UnwindTable. This is intended for use by target modules 148 // show-unwind where we want to create new UnwindPlans, not re-use existing 149 // ones. 150 FuncUnwindersSP 151 UnwindTable::GetUncachedFuncUnwindersContainingAddress(const Address &addr, 152 SymbolContext &sc) { 153 Initialize(); 154 155 auto range_or = GetAddressRange(addr, sc); 156 if (!range_or) 157 return nullptr; 158 159 return std::make_shared<FuncUnwinders>(*this, *range_or); 160 } 161 162 void UnwindTable::Dump(Stream &s) { 163 std::lock_guard<std::mutex> guard(m_mutex); 164 s.Format("UnwindTable for '{0}':\n", m_module.GetFileSpec()); 165 const_iterator begin = m_unwinds.begin(); 166 const_iterator end = m_unwinds.end(); 167 for (const_iterator pos = begin; pos != end; ++pos) { 168 s.Printf("[%u] 0x%16.16" PRIx64 "\n", (unsigned)std::distance(begin, pos), 169 pos->first); 170 } 171 s.EOL(); 172 } 173 174 lldb_private::CallFrameInfo *UnwindTable::GetObjectFileUnwindInfo() { 175 Initialize(); 176 return m_object_file_unwind_up.get(); 177 } 178 179 DWARFCallFrameInfo *UnwindTable::GetEHFrameInfo() { 180 Initialize(); 181 return m_eh_frame_up.get(); 182 } 183 184 DWARFCallFrameInfo *UnwindTable::GetDebugFrameInfo() { 185 Initialize(); 186 return m_debug_frame_up.get(); 187 } 188 189 CompactUnwindInfo *UnwindTable::GetCompactUnwindInfo() { 190 Initialize(); 191 return m_compact_unwind_up.get(); 192 } 193 194 ArmUnwindInfo *UnwindTable::GetArmUnwindInfo() { 195 Initialize(); 196 return m_arm_unwind_up.get(); 197 } 198 199 SymbolFile *UnwindTable::GetSymbolFile() { return m_module.GetSymbolFile(); } 200 201 ArchSpec UnwindTable::GetArchitecture() { return m_module.GetArchitecture(); } 202 203 bool UnwindTable::GetAllowAssemblyEmulationUnwindPlans() { 204 if (ObjectFile *object_file = m_module.GetObjectFile()) 205 return object_file->AllowAssemblyEmulationUnwindPlans(); 206 return false; 207 } 208