1//===-- SymbolLocatorDefault.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 "SymbolLocatorDefault.h"
10
11#include <cstring>
12#include <optional>
13
14#include "Plugins/ObjectFile/wasm/ObjectFileWasm.h"
15#include "lldb/Core/Debugger.h"
16#include "lldb/Core/Module.h"
17#include "lldb/Core/ModuleList.h"
18#include "lldb/Core/ModuleSpec.h"
19#include "lldb/Core/PluginManager.h"
20#include "lldb/Core/Progress.h"
21#include "lldb/Core/Section.h"
22#include "lldb/Host/FileSystem.h"
23#include "lldb/Host/Host.h"
24#include "lldb/Symbol/ObjectFile.h"
25#include "lldb/Target/Target.h"
26#include "lldb/Utility/ArchSpec.h"
27#include "lldb/Utility/DataBuffer.h"
28#include "lldb/Utility/DataExtractor.h"
29#include "lldb/Utility/LLDBLog.h"
30#include "lldb/Utility/Log.h"
31#include "lldb/Utility/StreamString.h"
32#include "lldb/Utility/Timer.h"
33#include "lldb/Utility/UUID.h"
34
35#include "llvm/ADT/SmallSet.h"
36#include "llvm/Support/FileSystem.h"
37#include "llvm/Support/ThreadPool.h"
38
39#if defined(__FreeBSD__)
40#include <sys/sysctl.h>
41#endif
42
43// From MacOSX system header "mach/machine.h"
44typedef int cpu_type_t;
45typedef int cpu_subtype_t;
46
47using namespace lldb;
48using namespace lldb_private;
49
50LLDB_PLUGIN_DEFINE(SymbolLocatorDefault)
51
52SymbolLocatorDefault::SymbolLocatorDefault() : SymbolLocator() {}
53
54void SymbolLocatorDefault::Initialize() {
55 PluginManager::RegisterPlugin(
56 name: GetPluginNameStatic(), description: GetPluginDescriptionStatic(), create_callback: CreateInstance,
57 locate_executable_object_file: LocateExecutableObjectFile, locate_executable_symbol_file: LocateExecutableSymbolFile,
58 download_object_symbol_file: DownloadObjectAndSymbolFile);
59}
60
61void SymbolLocatorDefault::Terminate() {
62 PluginManager::UnregisterPlugin(create_callback: CreateInstance);
63}
64
65llvm::StringRef SymbolLocatorDefault::GetPluginDescriptionStatic() {
66 return "Default symbol locator.";
67}
68
69SymbolLocator *SymbolLocatorDefault::CreateInstance() {
70 return new SymbolLocatorDefault();
71}
72
73std::optional<ModuleSpec> SymbolLocatorDefault::LocateExecutableObjectFile(
74 const ModuleSpec &module_spec) {
75 const FileSpec &exec_fspec = module_spec.GetFileSpec();
76 const ArchSpec *arch = module_spec.GetArchitecturePtr();
77 const UUID *uuid = module_spec.GetUUIDPtr();
78 LLDB_SCOPED_TIMERF(
79 "LocateExecutableObjectFile (file = %s, arch = %s, uuid = %p)",
80 exec_fspec ? exec_fspec.GetFilename().AsCString("<NULL>") : "<NULL>",
81 arch ? arch->GetArchitectureName() : "<NULL>", (const void *)uuid);
82
83 ModuleSpecList module_specs;
84 ModuleSpec matched_module_spec;
85 if (exec_fspec &&
86 ObjectFile::GetModuleSpecifications(file: exec_fspec, file_offset: 0, file_size: 0, specs&: module_specs) &&
87 module_specs.FindMatchingModuleSpec(module_spec, match_module_spec&: matched_module_spec)) {
88 ModuleSpec result;
89 result.GetFileSpec() = exec_fspec;
90 return result;
91 }
92
93 return {};
94}
95
96// Keep "symbols.enable-external-lookup" description in sync with this function.
97std::optional<FileSpec> SymbolLocatorDefault::LocateExecutableSymbolFile(
98 const ModuleSpec &module_spec, const FileSpecList &default_search_paths) {
99
100 FileSpec symbol_file_spec = module_spec.GetSymbolFileSpec();
101 if (symbol_file_spec.IsAbsolute() &&
102 FileSystem::Instance().Exists(file_spec: symbol_file_spec))
103 return symbol_file_spec;
104
105 Progress progress(
106 "Locating external symbol file",
107 module_spec.GetFileSpec().GetFilename().AsCString(value_if_empty: "<Unknown>"));
108
109 FileSpecList debug_file_search_paths = default_search_paths;
110
111 // Add module directory.
112 FileSpec module_file_spec = module_spec.GetFileSpec();
113 // We keep the unresolved pathname if it fails.
114 FileSystem::Instance().ResolveSymbolicLink(src: module_file_spec,
115 dst&: module_file_spec);
116
117 ConstString file_dir = module_file_spec.GetDirectory();
118 {
119 FileSpec file_spec(file_dir.AsCString(value_if_empty: "."));
120 FileSystem::Instance().Resolve(file_spec);
121 debug_file_search_paths.AppendIfUnique(file: file_spec);
122 }
123
124 if (ModuleList::GetGlobalModuleListProperties().GetEnableExternalLookup()) {
125
126 // Add current working directory.
127 {
128 FileSpec file_spec(".");
129 FileSystem::Instance().Resolve(file_spec);
130 debug_file_search_paths.AppendIfUnique(file: file_spec);
131 }
132
133#ifndef _WIN32
134#if defined(__NetBSD__)
135 // Add /usr/libdata/debug directory.
136 {
137 FileSpec file_spec("/usr/libdata/debug");
138 FileSystem::Instance().Resolve(file_spec);
139 debug_file_search_paths.AppendIfUnique(file_spec);
140 }
141#else
142 // Add /usr/lib/debug directory.
143 {
144 FileSpec file_spec("/usr/lib/debug");
145 FileSystem::Instance().Resolve(file_spec);
146 debug_file_search_paths.AppendIfUnique(file: file_spec);
147 }
148#if defined(__FreeBSD__)
149 // Add $LOCALBASE/lib/debug directory, where LOCALBASE is
150 // usually /usr/local, but may be adjusted by the end user.
151 {
152 int mib[2];
153 char buf[PATH_MAX];
154 size_t len = PATH_MAX;
155
156 mib[0] = CTL_USER;
157 mib[1] = USER_LOCALBASE;
158 if (::sysctl(mib, 2, buf, &len, NULL, 0) == 0) {
159 FileSpec file_spec("/lib/debug");
160 file_spec.PrependPathComponent(llvm::StringRef(buf));
161 FileSystem::Instance().Resolve(file_spec);
162 debug_file_search_paths.AppendIfUnique(file_spec);
163 }
164 }
165#endif // __FreeBSD__
166#endif
167#endif // _WIN32
168 }
169
170 std::string uuid_str;
171 const UUID &module_uuid = module_spec.GetUUID();
172 if (module_uuid.IsValid()) {
173 // Some debug files are stored in the .build-id directory like this:
174 // /usr/lib/debug/.build-id/ff/e7fe727889ad82bb153de2ad065b2189693315.debug
175 uuid_str = module_uuid.GetAsString(separator: "");
176 std::transform(first: uuid_str.begin(), last: uuid_str.end(), result: uuid_str.begin(),
177 unary_op: ::tolower);
178 uuid_str.insert(pos: 2, n: 1, c: '/');
179 uuid_str = uuid_str + ".debug";
180 }
181
182 size_t num_directories = debug_file_search_paths.GetSize();
183 for (size_t idx = 0; idx < num_directories; ++idx) {
184 FileSpec dirspec = debug_file_search_paths.GetFileSpecAtIndex(idx);
185 FileSystem::Instance().Resolve(file_spec&: dirspec);
186 if (!FileSystem::Instance().IsDirectory(file_spec: dirspec))
187 continue;
188
189 std::vector<std::string> files;
190 std::string dirname = dirspec.GetPath();
191
192 if (!uuid_str.empty())
193 files.push_back(x: dirname + "/.build-id/" + uuid_str);
194 if (symbol_file_spec.GetFilename()) {
195 files.push_back(x: dirname + "/" +
196 symbol_file_spec.GetFilename().GetCString());
197 files.push_back(x: dirname + "/.debug/" +
198 symbol_file_spec.GetFilename().GetCString());
199
200 // Some debug files may stored in the module directory like this:
201 // /usr/lib/debug/usr/lib/library.so.debug
202 if (!file_dir.IsEmpty())
203 files.push_back(x: dirname + file_dir.AsCString() + "/" +
204 symbol_file_spec.GetFilename().GetCString());
205 }
206
207 const uint32_t num_files = files.size();
208 for (size_t idx_file = 0; idx_file < num_files; ++idx_file) {
209 const std::string &filename = files[idx_file];
210 FileSpec file_spec(filename);
211 FileSystem::Instance().Resolve(file_spec);
212
213 if (llvm::sys::fs::equivalent(A: file_spec.GetPath(),
214 B: module_file_spec.GetPath()))
215 continue;
216
217 if (FileSystem::Instance().Exists(file_spec)) {
218 lldb_private::ModuleSpecList specs;
219 const size_t num_specs =
220 ObjectFile::GetModuleSpecifications(file: file_spec, file_offset: 0, file_size: 0, specs);
221 ModuleSpec mspec;
222 bool valid_mspec = false;
223 if (num_specs == 2) {
224 // Special case to handle both i386 and i686 from ObjectFilePECOFF
225 ModuleSpec mspec2;
226 if (specs.GetModuleSpecAtIndex(i: 0, module_spec&: mspec) &&
227 specs.GetModuleSpecAtIndex(i: 1, module_spec&: mspec2) &&
228 mspec.GetArchitecture().GetTriple().isCompatibleWith(
229 Other: mspec2.GetArchitecture().GetTriple())) {
230 valid_mspec = true;
231 }
232 }
233 if (!valid_mspec) {
234 assert(num_specs <= 1 &&
235 "Symbol Vendor supports only a single architecture");
236 if (num_specs == 1) {
237 if (specs.GetModuleSpecAtIndex(i: 0, module_spec&: mspec)) {
238 valid_mspec = true;
239 }
240 }
241 }
242 if (valid_mspec) {
243 // Skip the uuids check if module_uuid is invalid. For example,
244 // this happens for *.dwp files since at the moment llvm-dwp
245 // doesn't output build ids, nor does binutils dwp.
246 if (!module_uuid.IsValid() || module_uuid == mspec.GetUUID())
247 return file_spec;
248 }
249 }
250 }
251 }
252
253 return {};
254}
255
256bool SymbolLocatorDefault::DownloadObjectAndSymbolFile(ModuleSpec &module_spec,
257 Status &error,
258 bool force_lookup,
259 bool copy_executable) {
260 return false;
261}
262

source code of lldb/source/Plugins/SymbolLocator/Default/SymbolLocatorDefault.cpp