1 //===-- SymbolVendorELF.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 9 #include "SymbolVendorELF.h" 10 11 #include <cstring> 12 13 #include "Plugins/ObjectFile/ELF/ObjectFileELF.h" 14 #include "lldb/Core/Module.h" 15 #include "lldb/Core/ModuleSpec.h" 16 #include "lldb/Core/PluginManager.h" 17 #include "lldb/Core/Section.h" 18 #include "lldb/Host/Host.h" 19 #include "lldb/Symbol/ObjectFile.h" 20 #include "lldb/Target/Target.h" 21 #include "lldb/Utility/StreamString.h" 22 #include "lldb/Utility/Timer.h" 23 24 using namespace lldb; 25 using namespace lldb_private; 26 27 LLDB_PLUGIN_DEFINE(SymbolVendorELF) 28 29 // SymbolVendorELF constructor 30 SymbolVendorELF::SymbolVendorELF(const lldb::ModuleSP &module_sp) 31 : SymbolVendor(module_sp) {} 32 33 void SymbolVendorELF::Initialize() { 34 PluginManager::RegisterPlugin(GetPluginNameStatic(), 35 GetPluginDescriptionStatic(), CreateInstance); 36 } 37 38 void SymbolVendorELF::Terminate() { 39 PluginManager::UnregisterPlugin(CreateInstance); 40 } 41 42 llvm::StringRef SymbolVendorELF::GetPluginDescriptionStatic() { 43 return "Symbol vendor for ELF that looks for dSYM files that match " 44 "executables."; 45 } 46 47 // If this is needed elsewhere, it can be exported/moved. 48 static bool IsDwpSymbolFile(const lldb::ModuleSP &module_sp, 49 const FileSpec &file_spec) { 50 DataBufferSP dwp_file_data_sp; 51 lldb::offset_t dwp_file_data_offset = 0; 52 // Try to create an ObjectFile from the file_spec. 53 ObjectFileSP dwp_obj_file = ObjectFile::FindPlugin( 54 module_sp, &file_spec, 0, FileSystem::Instance().GetByteSize(file_spec), 55 dwp_file_data_sp, dwp_file_data_offset); 56 // The presence of a debug_cu_index section is the key identifying feature of 57 // a DWP file. Make sure we don't fill in the section list on dwp_obj_file 58 // (by calling GetSectionList(false)) as this function could be called before 59 // we may have all the symbol files collected and available. 60 return dwp_obj_file && ObjectFileELF::classof(dwp_obj_file.get()) && 61 dwp_obj_file->GetSectionList(false)->FindSectionByType( 62 eSectionTypeDWARFDebugCuIndex, false); 63 } 64 65 // CreateInstance 66 // 67 // Platforms can register a callback to use when creating symbol vendors to 68 // allow for complex debug information file setups, and to also allow for 69 // finding separate debug information files. 70 SymbolVendor * 71 SymbolVendorELF::CreateInstance(const lldb::ModuleSP &module_sp, 72 lldb_private::Stream *feedback_strm) { 73 if (!module_sp) 74 return nullptr; 75 76 ObjectFileELF *obj_file = 77 llvm::dyn_cast_or_null<ObjectFileELF>(module_sp->GetObjectFile()); 78 if (!obj_file) 79 return nullptr; 80 81 lldb_private::UUID uuid = obj_file->GetUUID(); 82 if (!uuid) 83 return nullptr; 84 85 // If the main object file already contains debug info, then we are done. 86 if (obj_file->GetSectionList()->FindSectionByType( 87 lldb::eSectionTypeDWARFDebugInfo, true)) 88 return nullptr; 89 90 // If the module specified a filespec, use that. 91 FileSpec fspec = module_sp->GetSymbolFileFileSpec(); 92 // Otherwise, try gnu_debuglink, if one exists. 93 if (!fspec) 94 fspec = obj_file->GetDebugLink().value_or(FileSpec()); 95 96 LLDB_SCOPED_TIMERF("SymbolVendorELF::CreateInstance (module = %s)", 97 module_sp->GetFileSpec().GetPath().c_str()); 98 99 ModuleSpec module_spec; 100 101 module_spec.GetFileSpec() = obj_file->GetFileSpec(); 102 FileSystem::Instance().Resolve(module_spec.GetFileSpec()); 103 module_spec.GetSymbolFileSpec() = fspec; 104 module_spec.GetUUID() = uuid; 105 FileSpecList search_paths = Target::GetDefaultDebugFileSearchPaths(); 106 FileSpec dsym_fspec = 107 PluginManager::LocateExecutableSymbolFile(module_spec, search_paths); 108 if (!dsym_fspec || IsDwpSymbolFile(module_sp, dsym_fspec)) { 109 // If we have a stripped binary or if we have a DWP file, SymbolLocator 110 // plugins may be able to give us an unstripped binary or an 111 // 'only-keep-debug' stripped file. 112 ModuleSpec unstripped_spec = 113 PluginManager::LocateExecutableObjectFile(module_spec); 114 if (!unstripped_spec) 115 return nullptr; 116 // The default SymbolLocator plugin returns the original binary if no other 117 // plugin finds something better. 118 if (unstripped_spec.GetFileSpec() == module_spec.GetFileSpec()) 119 return nullptr; 120 dsym_fspec = unstripped_spec.GetFileSpec(); 121 } 122 123 DataBufferSP dsym_file_data_sp; 124 lldb::offset_t dsym_file_data_offset = 0; 125 ObjectFileSP dsym_objfile_sp = ObjectFile::FindPlugin( 126 module_sp, &dsym_fspec, 0, FileSystem::Instance().GetByteSize(dsym_fspec), 127 dsym_file_data_sp, dsym_file_data_offset); 128 if (!dsym_objfile_sp) 129 return nullptr; 130 131 // This objfile is for debugging purposes. Sadly, ObjectFileELF won't 132 // be able to figure this out consistently as the symbol file may not 133 // have stripped the code sections, etc. 134 dsym_objfile_sp->SetType(ObjectFile::eTypeDebugInfo); 135 136 SymbolVendorELF *symbol_vendor = new SymbolVendorELF(module_sp); 137 138 // Get the module unified section list and add our debug sections to 139 // that. 140 SectionList *module_section_list = module_sp->GetSectionList(); 141 SectionList *objfile_section_list = dsym_objfile_sp->GetSectionList(); 142 143 if (!module_section_list || !objfile_section_list) 144 return nullptr; 145 146 static const SectionType g_sections[] = { 147 eSectionTypeDWARFDebugAbbrev, eSectionTypeDWARFDebugAddr, 148 eSectionTypeDWARFDebugAranges, eSectionTypeDWARFDebugCuIndex, 149 eSectionTypeDWARFDebugFrame, eSectionTypeDWARFDebugInfo, 150 eSectionTypeDWARFDebugLine, eSectionTypeDWARFDebugLineStr, 151 eSectionTypeDWARFDebugLoc, eSectionTypeDWARFDebugLocLists, 152 eSectionTypeDWARFDebugMacInfo, eSectionTypeDWARFDebugMacro, 153 eSectionTypeDWARFDebugNames, eSectionTypeDWARFDebugPubNames, 154 eSectionTypeDWARFDebugPubTypes, eSectionTypeDWARFDebugRanges, 155 eSectionTypeDWARFDebugRngLists, eSectionTypeDWARFDebugStr, 156 eSectionTypeDWARFDebugStrOffsets, eSectionTypeDWARFDebugTypes, 157 eSectionTypeELFSymbolTable, eSectionTypeDWARFGNUDebugAltLink, 158 }; 159 for (SectionType section_type : g_sections) { 160 if (SectionSP section_sp = 161 objfile_section_list->FindSectionByType(section_type, true)) { 162 if (SectionSP module_section_sp = 163 module_section_list->FindSectionByType(section_type, true)) 164 module_section_list->ReplaceSection(module_section_sp->GetID(), 165 section_sp); 166 else 167 module_section_list->AddSection(section_sp); 168 } 169 } 170 171 symbol_vendor->AddSymbolFileRepresentation(dsym_objfile_sp); 172 return symbol_vendor; 173 } 174