xref: /freebsd-src/contrib/llvm-project/lldb/source/Symbol/SymbolFile.cpp (revision ab80f0b21fbb9c44d40e6f7a99090188f4ed2f71)
1 //===-- SymbolFile.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 "lldb/Symbol/SymbolFile.h"
10 
11 #include "lldb/Core/Module.h"
12 #include "lldb/Core/PluginManager.h"
13 #include "lldb/Symbol/CompileUnit.h"
14 #include "lldb/Symbol/ObjectFile.h"
15 #include "lldb/Symbol/SymbolFileOnDemand.h"
16 #include "lldb/Symbol/TypeMap.h"
17 #include "lldb/Symbol/TypeSystem.h"
18 #include "lldb/Symbol/VariableList.h"
19 #include "lldb/Utility/Log.h"
20 #include "lldb/Utility/StreamString.h"
21 #include "lldb/lldb-private.h"
22 
23 #include <future>
24 
25 using namespace lldb_private;
26 using namespace lldb;
27 
28 char SymbolFile::ID;
29 char SymbolFileCommon::ID;
30 
31 void SymbolFile::PreloadSymbols() {
32   // No-op for most implementations.
33 }
34 
35 std::recursive_mutex &SymbolFile::GetModuleMutex() const {
36   return GetObjectFile()->GetModule()->GetMutex();
37 }
38 
39 SymbolFile *SymbolFile::FindPlugin(ObjectFileSP objfile_sp) {
40   std::unique_ptr<SymbolFile> best_symfile_up;
41   if (objfile_sp != nullptr) {
42 
43     // We need to test the abilities of this section list. So create what it
44     // would be with this new objfile_sp.
45     lldb::ModuleSP module_sp(objfile_sp->GetModule());
46     if (module_sp) {
47       // Default to the main module section list.
48       ObjectFile *module_obj_file = module_sp->GetObjectFile();
49       if (module_obj_file != objfile_sp.get()) {
50         // Make sure the main object file's sections are created
51         module_obj_file->GetSectionList();
52         objfile_sp->CreateSections(*module_sp->GetUnifiedSectionList());
53       }
54     }
55 
56     // TODO: Load any plug-ins in the appropriate plug-in search paths and
57     // iterate over all of them to find the best one for the job.
58 
59     uint32_t best_symfile_abilities = 0;
60 
61     SymbolFileCreateInstance create_callback;
62     for (uint32_t idx = 0;
63          (create_callback = PluginManager::GetSymbolFileCreateCallbackAtIndex(
64               idx)) != nullptr;
65          ++idx) {
66       std::unique_ptr<SymbolFile> curr_symfile_up(create_callback(objfile_sp));
67 
68       if (curr_symfile_up) {
69         const uint32_t sym_file_abilities = curr_symfile_up->GetAbilities();
70         if (sym_file_abilities > best_symfile_abilities) {
71           best_symfile_abilities = sym_file_abilities;
72           best_symfile_up.reset(curr_symfile_up.release());
73           // If any symbol file parser has all of the abilities, then we should
74           // just stop looking.
75           if ((kAllAbilities & sym_file_abilities) == kAllAbilities)
76             break;
77         }
78       }
79     }
80     if (best_symfile_up) {
81       // If symbol on-demand is enabled the winning symbol file parser is
82       // wrapped with SymbolFileOnDemand so that hydration of the debug info
83       // can be controlled to improve performance.
84       //
85       // Currently the supported on-demand symbol files include:
86       //  executables, shared libraries and debug info files.
87       //
88       // To reduce unnecessary wrapping files with zero debug abilities are
89       // skipped.
90       ObjectFile::Type obj_file_type = objfile_sp->CalculateType();
91       if (ModuleList::GetGlobalModuleListProperties().GetLoadSymbolOnDemand() &&
92           best_symfile_abilities > 0 &&
93           (obj_file_type == ObjectFile::eTypeExecutable ||
94            obj_file_type == ObjectFile::eTypeSharedLibrary ||
95            obj_file_type == ObjectFile::eTypeDebugInfo)) {
96         best_symfile_up =
97             std::make_unique<SymbolFileOnDemand>(std::move(best_symfile_up));
98       }
99       // Let the winning symbol file parser initialize itself more completely
100       // now that it has been chosen
101       best_symfile_up->InitializeObject();
102     }
103   }
104   return best_symfile_up.release();
105 }
106 
107 uint32_t
108 SymbolFile::ResolveSymbolContext(const SourceLocationSpec &src_location_spec,
109                                  lldb::SymbolContextItem resolve_scope,
110                                  SymbolContextList &sc_list) {
111   return 0;
112 }
113 
114 void SymbolFile::FindGlobalVariables(ConstString name,
115                                      const CompilerDeclContext &parent_decl_ctx,
116                                      uint32_t max_matches,
117                                      VariableList &variables) {}
118 
119 void SymbolFile::FindGlobalVariables(const RegularExpression &regex,
120                                      uint32_t max_matches,
121                                      VariableList &variables) {}
122 
123 void SymbolFile::FindFunctions(ConstString name,
124                                const CompilerDeclContext &parent_decl_ctx,
125                                lldb::FunctionNameType name_type_mask,
126                                bool include_inlines,
127                                SymbolContextList &sc_list) {}
128 
129 void SymbolFile::FindFunctions(const RegularExpression &regex,
130                                bool include_inlines,
131                                SymbolContextList &sc_list) {}
132 
133 void SymbolFile::GetMangledNamesForFunction(
134     const std::string &scope_qualified_name,
135     std::vector<ConstString> &mangled_names) {}
136 
137 void SymbolFile::FindTypes(
138     ConstString name, const CompilerDeclContext &parent_decl_ctx,
139     uint32_t max_matches,
140     llvm::DenseSet<lldb_private::SymbolFile *> &searched_symbol_files,
141     TypeMap &types) {}
142 
143 void SymbolFile::FindTypes(llvm::ArrayRef<CompilerContext> pattern,
144                            LanguageSet languages,
145                            llvm::DenseSet<SymbolFile *> &searched_symbol_files,
146                            TypeMap &types) {}
147 
148 void SymbolFile::AssertModuleLock() {
149   // The code below is too expensive to leave enabled in release builds. It's
150   // enabled in debug builds or when the correct macro is set.
151 #if defined(LLDB_CONFIGURATION_DEBUG)
152   // We assert that we have to module lock by trying to acquire the lock from a
153   // different thread. Note that we must abort if the result is true to
154   // guarantee correctness.
155   assert(std::async(
156              std::launch::async,
157              [this] {
158                return this->GetModuleMutex().try_lock();
159              }).get() == false &&
160          "Module is not locked");
161 #endif
162 }
163 
164 SymbolFile::RegisterInfoResolver::~RegisterInfoResolver() = default;
165 
166 Symtab *SymbolFileCommon::GetSymtab() {
167   std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
168   if (m_symtab)
169     return m_symtab;
170 
171   // Fetch the symtab from the main object file.
172   m_symtab = GetMainObjectFile()->GetSymtab();
173 
174   // Then add our symbols to it.
175   if (m_symtab)
176     AddSymbols(*m_symtab);
177 
178   return m_symtab;
179 }
180 
181 ObjectFile *SymbolFileCommon::GetMainObjectFile() {
182   return m_objfile_sp->GetModule()->GetObjectFile();
183 }
184 
185 void SymbolFileCommon::SectionFileAddressesChanged() {
186   ObjectFile *module_objfile = GetMainObjectFile();
187   ObjectFile *symfile_objfile = GetObjectFile();
188   if (symfile_objfile != module_objfile)
189     symfile_objfile->SectionFileAddressesChanged();
190   if (m_symtab)
191     m_symtab->SectionFileAddressesChanged();
192 }
193 
194 uint32_t SymbolFileCommon::GetNumCompileUnits() {
195   std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
196   if (!m_compile_units) {
197     // Create an array of compile unit shared pointers -- which will each
198     // remain NULL until someone asks for the actual compile unit information.
199     m_compile_units.emplace(CalculateNumCompileUnits());
200   }
201   return m_compile_units->size();
202 }
203 
204 CompUnitSP SymbolFileCommon::GetCompileUnitAtIndex(uint32_t idx) {
205   std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
206   uint32_t num = GetNumCompileUnits();
207   if (idx >= num)
208     return nullptr;
209   lldb::CompUnitSP &cu_sp = (*m_compile_units)[idx];
210   if (!cu_sp)
211     cu_sp = ParseCompileUnitAtIndex(idx);
212   return cu_sp;
213 }
214 
215 void SymbolFileCommon::SetCompileUnitAtIndex(uint32_t idx,
216                                              const CompUnitSP &cu_sp) {
217   std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
218   const size_t num_compile_units = GetNumCompileUnits();
219   assert(idx < num_compile_units);
220   (void)num_compile_units;
221 
222   // Fire off an assertion if this compile unit already exists for now. The
223   // partial parsing should take care of only setting the compile unit
224   // once, so if this assertion fails, we need to make sure that we don't
225   // have a race condition, or have a second parse of the same compile
226   // unit.
227   assert((*m_compile_units)[idx] == nullptr);
228   (*m_compile_units)[idx] = cu_sp;
229 }
230 
231 llvm::Expected<TypeSystem &>
232 SymbolFileCommon::GetTypeSystemForLanguage(lldb::LanguageType language) {
233   auto type_system_or_err =
234       m_objfile_sp->GetModule()->GetTypeSystemForLanguage(language);
235   if (type_system_or_err) {
236     type_system_or_err->SetSymbolFile(this);
237   }
238   return type_system_or_err;
239 }
240 
241 uint64_t SymbolFileCommon::GetDebugInfoSize() {
242   if (!m_objfile_sp)
243     return 0;
244   ModuleSP module_sp(m_objfile_sp->GetModule());
245   if (!module_sp)
246     return 0;
247   const SectionList *section_list = module_sp->GetSectionList();
248   if (section_list)
249     return section_list->GetDebugInfoSize();
250   return 0;
251 }
252 
253 void SymbolFileCommon::Dump(Stream &s) {
254   s.Format("SymbolFile {0} ({1})\n", GetPluginName(),
255            GetMainObjectFile()->GetFileSpec());
256   s.PutCString("Types:\n");
257   m_type_list.Dump(&s, /*show_context*/ false);
258   s.PutChar('\n');
259 
260   s.PutCString("Compile units:\n");
261   if (m_compile_units) {
262     for (const CompUnitSP &cu_sp : *m_compile_units) {
263       // We currently only dump the compile units that have been parsed
264       if (cu_sp)
265         cu_sp->Dump(&s, /*show_context*/ false);
266     }
267   }
268   s.PutChar('\n');
269 
270   if (Symtab *symtab = GetSymtab())
271     symtab->Dump(&s, nullptr, eSortOrderNone);
272 }
273