1 //===-- SymbolLocatorDebuginfod.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 "SymbolLocatorDebuginfod.h"
10 
11 #include "lldb/Core/PluginManager.h"
12 #include "lldb/Interpreter/OptionValueString.h"
13 #include "lldb/Utility/Args.h"
14 #include "lldb/Utility/LLDBLog.h"
15 #include "lldb/Utility/Log.h"
16 
17 #include "llvm/Debuginfod/Debuginfod.h"
18 #include "llvm/Debuginfod/HTTPClient.h"
19 
20 using namespace lldb;
21 using namespace lldb_private;
22 
23 LLDB_PLUGIN_DEFINE(SymbolLocatorDebuginfod)
24 
25 namespace {
26 
27 #define LLDB_PROPERTIES_symbollocatordebuginfod
28 #include "SymbolLocatorDebuginfodProperties.inc"
29 
30 enum {
31 #define LLDB_PROPERTIES_symbollocatordebuginfod
32 #include "SymbolLocatorDebuginfodPropertiesEnum.inc"
33 };
34 
35 class PluginProperties : public Properties {
36 public:
37   static llvm::StringRef GetSettingName() {
38     return SymbolLocatorDebuginfod::GetPluginNameStatic();
39   }
40 
41   PluginProperties() {
42     m_collection_sp = std::make_shared<OptionValueProperties>(GetSettingName());
43     m_collection_sp->Initialize(g_symbollocatordebuginfod_properties);
44 
45     // We need to read the default value first to read the environment variable.
46     llvm::SmallVector<llvm::StringRef> urls = llvm::getDefaultDebuginfodUrls();
47     Args arg_urls{urls};
48     m_collection_sp->SetPropertyAtIndexFromArgs(ePropertyServerURLs, arg_urls);
49 
50     m_collection_sp->SetValueChangedCallback(
51         ePropertyServerURLs, [this] { ServerURLsChangedCallback(); });
52   }
53 
54   Args GetDebugInfoDURLs() const {
55     Args urls;
56     m_collection_sp->GetPropertyAtIndexAsArgs(ePropertyServerURLs, urls);
57     return urls;
58   }
59 
60   llvm::Expected<std::string> GetCachePath() {
61     OptionValueString *s =
62         m_collection_sp->GetPropertyAtIndexAsOptionValueString(
63             ePropertySymbolCachePath);
64     // If we don't have a valid cache location, use the default one.
65     if (!s || !s->GetCurrentValueAsRef().size()) {
66       llvm::Expected<std::string> maybeCachePath =
67           llvm::getDefaultDebuginfodCacheDirectory();
68       if (!maybeCachePath)
69         return maybeCachePath;
70       return *maybeCachePath;
71     }
72     return s->GetCurrentValue();
73   }
74 
75   std::chrono::milliseconds GetTimeout() const {
76     std::optional<uint64_t> seconds =
77         m_collection_sp->GetPropertyAtIndexAs<uint64_t>(ePropertyTimeout);
78     if (seconds && *seconds != 0) {
79       return std::chrono::duration_cast<std::chrono::milliseconds>(
80           std::chrono::seconds(*seconds));
81     } else {
82       return llvm::getDefaultDebuginfodTimeout();
83     }
84   }
85 
86 private:
87   void ServerURLsChangedCallback() {
88     m_server_urls = GetDebugInfoDURLs();
89     llvm::SmallVector<llvm::StringRef> dbginfod_urls;
90     llvm::for_each(m_server_urls, [&](const auto &obj) {
91       dbginfod_urls.push_back(obj.ref());
92     });
93     llvm::setDefaultDebuginfodUrls(dbginfod_urls);
94   }
95   // Storage for the StringRef's used within the Debuginfod library.
96   Args m_server_urls;
97 };
98 
99 } // namespace
100 
101 static PluginProperties &GetGlobalPluginProperties() {
102   static PluginProperties g_settings;
103   return g_settings;
104 }
105 
106 SymbolLocatorDebuginfod::SymbolLocatorDebuginfod() : SymbolLocator() {}
107 
108 void SymbolLocatorDebuginfod::Initialize() {
109   static llvm::once_flag g_once_flag;
110 
111   llvm::call_once(g_once_flag, []() {
112     PluginManager::RegisterPlugin(
113         GetPluginNameStatic(), GetPluginDescriptionStatic(), CreateInstance,
114         LocateExecutableObjectFile, LocateExecutableSymbolFile, nullptr,
115         nullptr, SymbolLocatorDebuginfod::DebuggerInitialize);
116     llvm::HTTPClient::initialize();
117   });
118 }
119 
120 void SymbolLocatorDebuginfod::DebuggerInitialize(Debugger &debugger) {
121   if (!PluginManager::GetSettingForSymbolLocatorPlugin(
122           debugger, PluginProperties::GetSettingName())) {
123     const bool is_global_setting = true;
124     PluginManager::CreateSettingForSymbolLocatorPlugin(
125         debugger, GetGlobalPluginProperties().GetValueProperties(),
126         "Properties for the Debuginfod Symbol Locator plug-in.",
127         is_global_setting);
128   }
129 }
130 
131 void SymbolLocatorDebuginfod::Terminate() {
132   PluginManager::UnregisterPlugin(CreateInstance);
133   llvm::HTTPClient::cleanup();
134 }
135 
136 llvm::StringRef SymbolLocatorDebuginfod::GetPluginDescriptionStatic() {
137   return "Debuginfod symbol locator.";
138 }
139 
140 SymbolLocator *SymbolLocatorDebuginfod::CreateInstance() {
141   return new SymbolLocatorDebuginfod();
142 }
143 
144 static std::optional<FileSpec>
145 GetFileForModule(const ModuleSpec &module_spec,
146                  std::function<std::string(llvm::object::BuildID)> UrlBuilder) {
147   const UUID &module_uuid = module_spec.GetUUID();
148   // Don't bother if we don't have a valid UUID, Debuginfod isn't available,
149   // or if the 'symbols.enable-external-lookup' setting is false.
150   if (!module_uuid.IsValid() || !llvm::canUseDebuginfod() ||
151       !ModuleList::GetGlobalModuleListProperties().GetEnableExternalLookup())
152     return {};
153 
154   // Grab LLDB's Debuginfod overrides from the
155   // plugin.symbol-locator.debuginfod.* settings.
156   PluginProperties &plugin_props = GetGlobalPluginProperties();
157   llvm::Expected<std::string> cache_path_or_err = plugin_props.GetCachePath();
158   // A cache location is *required*.
159   if (!cache_path_or_err)
160     return {};
161   std::string cache_path = *cache_path_or_err;
162   llvm::SmallVector<llvm::StringRef> debuginfod_urls =
163       llvm::getDefaultDebuginfodUrls();
164   std::chrono::milliseconds timeout = plugin_props.GetTimeout();
165 
166   // We're ready to ask the Debuginfod library to find our file.
167   llvm::object::BuildID build_id(module_uuid.GetBytes());
168   std::string url_path = UrlBuilder(build_id);
169   std::string cache_key = llvm::getDebuginfodCacheKey(url_path);
170   llvm::Expected<std::string> result = llvm::getCachedOrDownloadArtifact(
171       cache_key, url_path, cache_path, debuginfod_urls, timeout);
172   if (result)
173     return FileSpec(*result);
174 
175   Log *log = GetLog(LLDBLog::Symbols);
176   auto err_message = llvm::toString(result.takeError());
177   LLDB_LOGV(log,
178             "Debuginfod failed to download symbol artifact {0} with error {1}",
179             url_path, err_message);
180   return {};
181 }
182 
183 std::optional<ModuleSpec> SymbolLocatorDebuginfod::LocateExecutableObjectFile(
184     const ModuleSpec &module_spec) {
185   return GetFileForModule(module_spec, llvm::getDebuginfodExecutableUrlPath);
186 }
187 
188 std::optional<FileSpec> SymbolLocatorDebuginfod::LocateExecutableSymbolFile(
189     const ModuleSpec &module_spec, const FileSpecList &default_search_paths) {
190   return GetFileForModule(module_spec, llvm::getDebuginfodDebuginfoUrlPath);
191 }
192