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
24using namespace lldb;
25using namespace lldb_private;
26
27LLDB_PLUGIN_DEFINE(SymbolVendorELF)
28
29// SymbolVendorELF constructor
30SymbolVendorELF::SymbolVendorELF(const lldb::ModuleSP &module_sp)
31    : SymbolVendor(module_sp) {}
32
33void SymbolVendorELF::Initialize() {
34  PluginManager::RegisterPlugin(GetPluginNameStatic(),
35                                GetPluginDescriptionStatic(), CreateInstance);
36}
37
38void SymbolVendorELF::Terminate() {
39  PluginManager::UnregisterPlugin(CreateInstance);
40}
41
42llvm::StringRef SymbolVendorELF::GetPluginDescriptionStatic() {
43  return "Symbol vendor for ELF that looks for dSYM files that match "
44         "executables.";
45}
46
47// CreateInstance
48//
49// Platforms can register a callback to use when creating symbol vendors to
50// allow for complex debug information file setups, and to also allow for
51// finding separate debug information files.
52SymbolVendor *
53SymbolVendorELF::CreateInstance(const lldb::ModuleSP &module_sp,
54                                lldb_private::Stream *feedback_strm) {
55  if (!module_sp)
56    return nullptr;
57
58  ObjectFileELF *obj_file =
59      llvm::dyn_cast_or_null<ObjectFileELF>(module_sp->GetObjectFile());
60  if (!obj_file)
61    return nullptr;
62
63  lldb_private::UUID uuid = obj_file->GetUUID();
64  if (!uuid)
65    return nullptr;
66
67  // If the main object file already contains debug info, then we are done.
68  if (obj_file->GetSectionList()->FindSectionByType(
69          lldb::eSectionTypeDWARFDebugInfo, true))
70    return nullptr;
71
72  // If the module specified a filespec, use that.
73  FileSpec fspec = module_sp->GetSymbolFileFileSpec();
74  // Otherwise, try gnu_debuglink, if one exists.
75  if (!fspec)
76    fspec = obj_file->GetDebugLink().value_or(FileSpec());
77
78  LLDB_SCOPED_TIMERF("SymbolVendorELF::CreateInstance (module = %s)",
79                     module_sp->GetFileSpec().GetPath().c_str());
80
81  ModuleSpec module_spec;
82
83  module_spec.GetFileSpec() = obj_file->GetFileSpec();
84  FileSystem::Instance().Resolve(module_spec.GetFileSpec());
85  module_spec.GetSymbolFileSpec() = fspec;
86  module_spec.GetUUID() = uuid;
87  FileSpecList search_paths = Target::GetDefaultDebugFileSearchPaths();
88  FileSpec dsym_fspec =
89      PluginManager::LocateExecutableSymbolFile(module_spec, search_paths);
90  if (!dsym_fspec)
91    return nullptr;
92
93  DataBufferSP dsym_file_data_sp;
94  lldb::offset_t dsym_file_data_offset = 0;
95  ObjectFileSP dsym_objfile_sp = ObjectFile::FindPlugin(
96      module_sp, &dsym_fspec, 0, FileSystem::Instance().GetByteSize(dsym_fspec),
97      dsym_file_data_sp, dsym_file_data_offset);
98  if (!dsym_objfile_sp)
99    return nullptr;
100
101  // This objfile is for debugging purposes. Sadly, ObjectFileELF won't
102  // be able to figure this out consistently as the symbol file may not
103  // have stripped the code sections, etc.
104  dsym_objfile_sp->SetType(ObjectFile::eTypeDebugInfo);
105
106  SymbolVendorELF *symbol_vendor = new SymbolVendorELF(module_sp);
107
108  // Get the module unified section list and add our debug sections to
109  // that.
110  SectionList *module_section_list = module_sp->GetSectionList();
111  SectionList *objfile_section_list = dsym_objfile_sp->GetSectionList();
112
113  if (!module_section_list || !objfile_section_list)
114    return nullptr;
115
116  static const SectionType g_sections[] = {
117      eSectionTypeDWARFDebugAbbrev,     eSectionTypeDWARFDebugAddr,
118      eSectionTypeDWARFDebugAranges,    eSectionTypeDWARFDebugCuIndex,
119      eSectionTypeDWARFDebugFrame,      eSectionTypeDWARFDebugInfo,
120      eSectionTypeDWARFDebugLine,       eSectionTypeDWARFDebugLineStr,
121      eSectionTypeDWARFDebugLoc,        eSectionTypeDWARFDebugLocLists,
122      eSectionTypeDWARFDebugMacInfo,    eSectionTypeDWARFDebugMacro,
123      eSectionTypeDWARFDebugNames,      eSectionTypeDWARFDebugPubNames,
124      eSectionTypeDWARFDebugPubTypes,   eSectionTypeDWARFDebugRanges,
125      eSectionTypeDWARFDebugRngLists,   eSectionTypeDWARFDebugStr,
126      eSectionTypeDWARFDebugStrOffsets, eSectionTypeDWARFDebugTypes,
127      eSectionTypeELFSymbolTable,       eSectionTypeDWARFGNUDebugAltLink,
128  };
129  for (SectionType section_type : g_sections) {
130    if (SectionSP section_sp =
131            objfile_section_list->FindSectionByType(section_type, true)) {
132      if (SectionSP module_section_sp =
133              module_section_list->FindSectionByType(section_type, true))
134        module_section_list->ReplaceSection(module_section_sp->GetID(),
135                                            section_sp);
136      else
137        module_section_list->AddSection(section_sp);
138    }
139  }
140
141  symbol_vendor->AddSymbolFileRepresentation(dsym_objfile_sp);
142  return symbol_vendor;
143}
144