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 uint32_t
106 SymbolFile::FindGlobalVariables(ConstString name,
107                                 const CompilerDeclContext *parent_decl_ctx,
108                                 uint32_t max_matches, VariableList &variables) {
109   return 0;
110 }
111 
112 uint32_t SymbolFile::FindGlobalVariables(const RegularExpression &regex,
113                                          uint32_t max_matches,
114                                          VariableList &variables) {
115   return 0;
116 }
117 
118 uint32_t SymbolFile::FindFunctions(ConstString name,
119                                    const CompilerDeclContext *parent_decl_ctx,
120                                    lldb::FunctionNameType name_type_mask,
121                                    bool include_inlines, bool append,
122                                    SymbolContextList &sc_list) {
123   if (!append)
124     sc_list.Clear();
125   return 0;
126 }
127 
128 uint32_t SymbolFile::FindFunctions(const RegularExpression &regex,
129                                    bool include_inlines, bool append,
130                                    SymbolContextList &sc_list) {
131   if (!append)
132     sc_list.Clear();
133   return 0;
134 }
135 
136 void SymbolFile::GetMangledNamesForFunction(
137     const std::string &scope_qualified_name,
138     std::vector<ConstString> &mangled_names) {
139   return;
140 }
141 
142 void SymbolFile::FindTypes(
143     ConstString name, const CompilerDeclContext *parent_decl_ctx,
144     uint32_t max_matches,
145     llvm::DenseSet<lldb_private::SymbolFile *> &searched_symbol_files,
146     TypeMap &types) {}
147 
148 void SymbolFile::FindTypes(llvm::ArrayRef<CompilerContext> pattern,
149                            LanguageSet languages, TypeMap &types) {}
150 
151 void SymbolFile::AssertModuleLock() {
152   // The code below is too expensive to leave enabled in release builds. It's
153   // enabled in debug builds or when the correct macro is set.
154 #if defined(LLDB_CONFIGURATION_DEBUG)
155   // We assert that we have to module lock by trying to acquire the lock from a
156   // different thread. Note that we must abort if the result is true to
157   // guarantee correctness.
158   assert(std::async(std::launch::async,
159                     [this] { return this->GetModuleMutex().try_lock(); })
160                  .get() == false &&
161          "Module is not locked");
162 #endif
163 }
164 
165 uint32_t SymbolFile::GetNumCompileUnits() {
166   std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
167   if (!m_compile_units) {
168     // Create an array of compile unit shared pointers -- which will each
169     // remain NULL until someone asks for the actual compile unit information.
170     m_compile_units.emplace(CalculateNumCompileUnits());
171   }
172   return m_compile_units->size();
173 }
174 
175 CompUnitSP SymbolFile::GetCompileUnitAtIndex(uint32_t idx) {
176   std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
177   uint32_t num = GetNumCompileUnits();
178   if (idx >= num)
179     return nullptr;
180   lldb::CompUnitSP &cu_sp = (*m_compile_units)[idx];
181   if (!cu_sp)
182     cu_sp = ParseCompileUnitAtIndex(idx);
183   return cu_sp;
184 }
185 
186 void SymbolFile::SetCompileUnitAtIndex(uint32_t idx, const CompUnitSP &cu_sp) {
187   std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
188   const size_t num_compile_units = GetNumCompileUnits();
189   assert(idx < num_compile_units);
190   (void)num_compile_units;
191 
192   // Fire off an assertion if this compile unit already exists for now. The
193   // partial parsing should take care of only setting the compile unit
194   // once, so if this assertion fails, we need to make sure that we don't
195   // have a race condition, or have a second parse of the same compile
196   // unit.
197   assert((*m_compile_units)[idx] == nullptr);
198   (*m_compile_units)[idx] = cu_sp;
199 }
200 
201 Symtab *SymbolFile::GetSymtab() {
202   std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
203   if (m_symtab)
204     return m_symtab;
205 
206   // Fetch the symtab from the main object file.
207   m_symtab = GetMainObjectFile()->GetSymtab();
208 
209   // Then add our symbols to it.
210   if (m_symtab)
211     AddSymbols(*m_symtab);
212 
213   return m_symtab;
214 }
215 
216 void SymbolFile::SectionFileAddressesChanged() {
217   ObjectFile *module_objfile = GetMainObjectFile();
218   ObjectFile *symfile_objfile = GetObjectFile();
219   if (symfile_objfile != module_objfile)
220     symfile_objfile->SectionFileAddressesChanged();
221   if (m_symtab)
222     m_symtab->SectionFileAddressesChanged();
223 }
224 
225 void SymbolFile::Dump(Stream &s) {
226   s.Format("SymbolFile {0} ({1})\n", GetPluginName(),
227            GetMainObjectFile()->GetFileSpec());
228   s.PutCString("Types:\n");
229   m_type_list.Dump(&s, /*show_context*/ false);
230   s.PutChar('\n');
231 
232   s.PutCString("Compile units:\n");
233   if (m_compile_units) {
234     for (const CompUnitSP &cu_sp : *m_compile_units) {
235       // We currently only dump the compile units that have been parsed
236       if (cu_sp)
237         cu_sp->Dump(&s, /*show_context*/ false);
238     }
239   }
240   s.PutChar('\n');
241 
242   if (Symtab *symtab = GetSymtab())
243     symtab->Dump(&s, nullptr, eSortOrderNone);
244 }
245 
246 SymbolFile::RegisterInfoResolver::~RegisterInfoResolver() = default;
247