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