lldb/source/Symbol/SymbolFile.cpp

   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/Utility/StructuredData.h"
  22 #include "lldb/lldb-private.h"
  23
  24 #include <future>
  25
  26 using namespace lldb_private;
  27 using namespace lldb;
  28
  29 char SymbolFile::ID;
  30 char SymbolFileCommon::ID;
  31
  32 void SymbolFile::PreloadSymbols() {
  33   // No-op for most implementations.
  34 }
  35
  36 std::recursive_mutex &SymbolFile::GetModuleMutex() const {
  37   return GetObjectFile()->GetModule()->GetMutex();
  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       // If symbol on-demand is enabled the winning symbol file parser is
  83       // wrapped with SymbolFileOnDemand so that hydration of the debug info
  84       // can be controlled to improve performance.
  85       //
  86       // Currently the supported on-demand symbol files include:
  87       //  executables, shared libraries and debug info files.
  88       //
  89       // To reduce unnecessary wrapping files with zero debug abilities are
  90       // skipped.
  91       ObjectFile::Type obj_file_type = objfile_sp->CalculateType();
  92       if (ModuleList::GetGlobalModuleListProperties().GetLoadSymbolOnDemand() &&
  93           best_symfile_abilities > 0 &&
  94           (obj_file_type == ObjectFile::eTypeExecutable ||
  95            obj_file_type == ObjectFile::eTypeSharedLibrary ||
  96            obj_file_type == ObjectFile::eTypeDebugInfo)) {
  97         best_symfile_up =
  98             std::make_unique<SymbolFileOnDemand>(std::move(best_symfile_up));
  99       }
 100       // Let the winning symbol file parser initialize itself more completely
 101       // now that it has been chosen
 102       best_symfile_up->InitializeObject();
 103     }
 104   }
 105   return best_symfile_up.release();
 106 }
 107
 108 uint32_t
 109 SymbolFile::ResolveSymbolContext(const SourceLocationSpec &src_location_spec,
 110                                  lldb::SymbolContextItem resolve_scope,
 111                                  SymbolContextList &sc_list) {
 112   return 0;
 113 }
 114
 115 void SymbolFile::FindGlobalVariables(ConstString name,
 116                                      const CompilerDeclContext &parent_decl_ctx,
 117                                      uint32_t max_matches,
 118                                      VariableList &variables) {}
 119
 120 void SymbolFile::FindGlobalVariables(const RegularExpression &regex,
 121                                      uint32_t max_matches,
 122                                      VariableList &variables) {}
 123
 124 void SymbolFile::FindFunctions(const Module::LookupInfo &lookup_info,
 125                                const CompilerDeclContext &parent_decl_ctx,
 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   // Fetch the symtab from the main object file.
 169   auto *symtab = GetMainObjectFile()->GetSymtab();
 170   if (m_symtab != symtab) {
 171     m_symtab = symtab;
 172
 173     // Then add our symbols to it.
 174     if (m_symtab)
 175       AddSymbols(*m_symtab);
 176   }
 177   return m_symtab;
 178 }
 179
 180 ObjectFile *SymbolFileCommon::GetMainObjectFile() {
 181   return m_objfile_sp->GetModule()->GetObjectFile();
 182 }
 183
 184 void SymbolFileCommon::SectionFileAddressesChanged() {
 185   ObjectFile *module_objfile = GetMainObjectFile();
 186   ObjectFile *symfile_objfile = GetObjectFile();
 187   if (symfile_objfile != module_objfile)
 188     symfile_objfile->SectionFileAddressesChanged();
 189   if (auto *symtab = GetSymtab())
 190     symtab->SectionFileAddressesChanged();
 191 }
 192
 193 uint32_t SymbolFileCommon::GetNumCompileUnits() {
 194   std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
 195   if (!m_compile_units) {
 196     // Create an array of compile unit shared pointers -- which will each
 197     // remain NULL until someone asks for the actual compile unit information.
 198     m_compile_units.emplace(CalculateNumCompileUnits());
 199   }
 200   return m_compile_units->size();
 201 }
 202
 203 CompUnitSP SymbolFileCommon::GetCompileUnitAtIndex(uint32_t idx) {
 204   std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
 205   uint32_t num = GetNumCompileUnits();
 206   if (idx >= num)
 207     return nullptr;
 208   lldb::CompUnitSP &cu_sp = (*m_compile_units)[idx];
 209   if (!cu_sp)
 210     cu_sp = ParseCompileUnitAtIndex(idx);
 211   return cu_sp;
 212 }
 213
 214 void SymbolFileCommon::SetCompileUnitAtIndex(uint32_t idx,
 215                                              const CompUnitSP &cu_sp) {
 216   std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
 217   const size_t num_compile_units = GetNumCompileUnits();
 218   assert(idx < num_compile_units);
 219   (void)num_compile_units;
 220
 221   // Fire off an assertion if this compile unit already exists for now. The
 222   // partial parsing should take care of only setting the compile unit
 223   // once, so if this assertion fails, we need to make sure that we don't
 224   // have a race condition, or have a second parse of the same compile
 225   // unit.
 226   assert((*m_compile_units)[idx] == nullptr);
 227   (*m_compile_units)[idx] = cu_sp;
 228 }
 229
 230 llvm::Expected<TypeSystemSP>
 231 SymbolFileCommon::GetTypeSystemForLanguage(lldb::LanguageType language) {
 232   auto type_system_or_err =
 233       m_objfile_sp->GetModule()->GetTypeSystemForLanguage(language);
 234   if (type_system_or_err) {
 235     if (auto ts = *type_system_or_err)
 236       ts->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 }