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