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_obj_file->GetModule()->GetObjectFile();
36 }
37 
38 SymbolFile *SymbolFile::FindPlugin(ObjectFile *obj_file) {
39   std::unique_ptr<SymbolFile> best_symfile_up;
40   if (obj_file != nullptr) {
41 
42     // We need to test the abilities of this section list. So create what it
43     // would be with this new obj_file.
44     lldb::ModuleSP module_sp(obj_file->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 != obj_file) {
49         // Make sure the main object file's sections are created
50         module_obj_file->GetSectionList();
51         obj_file->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(obj_file));
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 TypeSystem *SymbolFile::GetTypeSystemForLanguage(lldb::LanguageType language) {
89   TypeSystem *type_system =
90       m_obj_file->GetModule()->GetTypeSystemForLanguage(language);
91   if (type_system)
92     type_system->SetSymbolFile(this);
93   return type_system;
94 }
95 
96 uint32_t SymbolFile::ResolveSymbolContext(const FileSpec &file_spec,
97                                           uint32_t line, bool check_inlines,
98                                           lldb::SymbolContextItem resolve_scope,
99                                           SymbolContextList &sc_list) {
100   return 0;
101 }
102 
103 uint32_t
104 SymbolFile::FindGlobalVariables(ConstString name,
105                                 const CompilerDeclContext *parent_decl_ctx,
106                                 uint32_t max_matches, VariableList &variables) {
107   return 0;
108 }
109 
110 uint32_t SymbolFile::FindGlobalVariables(const RegularExpression &regex,
111                                          uint32_t max_matches,
112                                          VariableList &variables) {
113   return 0;
114 }
115 
116 uint32_t SymbolFile::FindFunctions(ConstString name,
117                                    const CompilerDeclContext *parent_decl_ctx,
118                                    lldb::FunctionNameType name_type_mask,
119                                    bool include_inlines, bool append,
120                                    SymbolContextList &sc_list) {
121   if (!append)
122     sc_list.Clear();
123   return 0;
124 }
125 
126 uint32_t SymbolFile::FindFunctions(const RegularExpression &regex,
127                                    bool include_inlines, bool append,
128                                    SymbolContextList &sc_list) {
129   if (!append)
130     sc_list.Clear();
131   return 0;
132 }
133 
134 void SymbolFile::GetMangledNamesForFunction(
135     const std::string &scope_qualified_name,
136     std::vector<ConstString> &mangled_names) {
137   return;
138 }
139 
140 uint32_t SymbolFile::FindTypes(
141     ConstString name, const CompilerDeclContext *parent_decl_ctx,
142     bool append, uint32_t max_matches,
143     llvm::DenseSet<lldb_private::SymbolFile *> &searched_symbol_files,
144     TypeMap &types) {
145   if (!append)
146     types.Clear();
147   return 0;
148 }
149 
150 size_t SymbolFile::FindTypes(const std::vector<CompilerContext> &context,
151                              bool append, TypeMap &types) {
152   if (!append)
153     types.Clear();
154   return 0;
155 }
156 
157 void SymbolFile::AssertModuleLock() {
158   // The code below is too expensive to leave enabled in release builds. It's
159   // enabled in debug builds or when the correct macro is set.
160 #if defined(LLDB_CONFIGURATION_DEBUG)
161   // We assert that we have to module lock by trying to acquire the lock from a
162   // different thread. Note that we must abort if the result is true to
163   // guarantee correctness.
164   assert(std::async(std::launch::async,
165                     [this] { return this->GetModuleMutex().try_lock(); })
166                  .get() == false &&
167          "Module is not locked");
168 #endif
169 }
170 
171 uint32_t SymbolFile::GetNumCompileUnits() {
172   std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
173   if (!m_compile_units) {
174     // Create an array of compile unit shared pointers -- which will each
175     // remain NULL until someone asks for the actual compile unit information.
176     m_compile_units.emplace(CalculateNumCompileUnits());
177   }
178   return m_compile_units->size();
179 }
180 
181 CompUnitSP SymbolFile::GetCompileUnitAtIndex(uint32_t idx) {
182   uint32_t num = GetNumCompileUnits();
183   if (idx >= num)
184     return nullptr;
185   lldb::CompUnitSP &cu_sp = (*m_compile_units)[idx];
186   if (!cu_sp)
187     cu_sp = ParseCompileUnitAtIndex(idx);
188   return cu_sp;
189 }
190 
191 void SymbolFile::SetCompileUnitAtIndex(uint32_t idx, const CompUnitSP &cu_sp) {
192   std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
193   const size_t num_compile_units = GetNumCompileUnits();
194   assert(idx < num_compile_units);
195   (void)num_compile_units;
196 
197   // Fire off an assertion if this compile unit already exists for now. The
198   // partial parsing should take care of only setting the compile unit
199   // once, so if this assertion fails, we need to make sure that we don't
200   // have a race condition, or have a second parse of the same compile
201   // unit.
202   assert((*m_compile_units)[idx] == nullptr);
203   (*m_compile_units)[idx] = cu_sp;
204 }
205 
206 Symtab *SymbolFile::GetSymtab() {
207   std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
208   if (m_symtab)
209     return m_symtab;
210 
211   // Fetch the symtab from the main object file.
212   m_symtab = GetMainObjectFile()->GetSymtab();
213 
214   // Then add our symbols to it.
215   if (m_symtab)
216     AddSymbols(*m_symtab);
217 
218   return m_symtab;
219 }
220 
221 void SymbolFile::SectionFileAddressesChanged() {
222   ObjectFile *module_objfile = GetMainObjectFile();
223   ObjectFile *symfile_objfile = GetObjectFile();
224   if (symfile_objfile != module_objfile)
225     symfile_objfile->SectionFileAddressesChanged();
226   if (m_symtab)
227     m_symtab->SectionFileAddressesChanged();
228 }
229 
230 void SymbolFile::Dump(Stream &s) {
231   s.PutCString("Types:\n");
232   m_type_list.Dump(&s, /*show_context*/ false);
233   s.PutChar('\n');
234 
235   s.PutCString("Compile units:\n");
236   if (m_compile_units) {
237     for (const CompUnitSP &cu_sp : *m_compile_units) {
238       // We currently only dump the compile units that have been parsed
239       if (cu_sp)
240         cu_sp->Dump(&s, /*show_context*/ false);
241     }
242   }
243   s.PutChar('\n');
244 }
245 
246 SymbolFile::RegisterInfoResolver::~RegisterInfoResolver() = default;
247