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
26using namespace lldb_private;
27using namespace lldb;
28
29char SymbolFile::ID;
30char SymbolFileCommon::ID;
31
32void SymbolFile::PreloadSymbols() {
33  // No-op for most implementations.
34}
35
36std::recursive_mutex &SymbolFile::GetModuleMutex() const {
37  return GetObjectFile()->GetModule()->GetMutex();
38}
39
40SymbolFile *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
108uint32_t
109SymbolFile::ResolveSymbolContext(const SourceLocationSpec &src_location_spec,
110                                 lldb::SymbolContextItem resolve_scope,
111                                 SymbolContextList &sc_list) {
112  return 0;
113}
114
115void SymbolFile::FindGlobalVariables(ConstString name,
116                                     const CompilerDeclContext &parent_decl_ctx,
117                                     uint32_t max_matches,
118                                     VariableList &variables) {}
119
120void SymbolFile::FindGlobalVariables(const RegularExpression &regex,
121                                     uint32_t max_matches,
122                                     VariableList &variables) {}
123
124void SymbolFile::FindFunctions(const Module::LookupInfo &lookup_info,
125                               const CompilerDeclContext &parent_decl_ctx,
126                               bool include_inlines,
127                               SymbolContextList &sc_list) {}
128
129void SymbolFile::FindFunctions(const RegularExpression &regex,
130                               bool include_inlines,
131                               SymbolContextList &sc_list) {}
132
133void SymbolFile::GetMangledNamesForFunction(
134    const std::string &scope_qualified_name,
135    std::vector<ConstString> &mangled_names) {}
136
137void SymbolFile::AssertModuleLock() {
138  // The code below is too expensive to leave enabled in release builds. It's
139  // enabled in debug builds or when the correct macro is set.
140#if defined(LLDB_CONFIGURATION_DEBUG)
141  // We assert that we have to module lock by trying to acquire the lock from a
142  // different thread. Note that we must abort if the result is true to
143  // guarantee correctness.
144  assert(std::async(
145             std::launch::async,
146             [this] {
147               return this->GetModuleMutex().try_lock();
148             }).get() == false &&
149         "Module is not locked");
150#endif
151}
152
153SymbolFile::RegisterInfoResolver::~RegisterInfoResolver() = default;
154
155Symtab *SymbolFileCommon::GetSymtab() {
156  std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
157  // Fetch the symtab from the main object file.
158  auto *symtab = GetMainObjectFile()->GetSymtab();
159  if (m_symtab != symtab) {
160    m_symtab = symtab;
161
162    // Then add our symbols to it.
163    if (m_symtab)
164      AddSymbols(*m_symtab);
165  }
166  return m_symtab;
167}
168
169ObjectFile *SymbolFileCommon::GetMainObjectFile() {
170  return m_objfile_sp->GetModule()->GetObjectFile();
171}
172
173void SymbolFileCommon::SectionFileAddressesChanged() {
174  ObjectFile *module_objfile = GetMainObjectFile();
175  ObjectFile *symfile_objfile = GetObjectFile();
176  if (symfile_objfile != module_objfile)
177    symfile_objfile->SectionFileAddressesChanged();
178  if (auto *symtab = GetSymtab())
179    symtab->SectionFileAddressesChanged();
180}
181
182uint32_t SymbolFileCommon::GetNumCompileUnits() {
183  std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
184  if (!m_compile_units) {
185    // Create an array of compile unit shared pointers -- which will each
186    // remain NULL until someone asks for the actual compile unit information.
187    m_compile_units.emplace(CalculateNumCompileUnits());
188  }
189  return m_compile_units->size();
190}
191
192CompUnitSP SymbolFileCommon::GetCompileUnitAtIndex(uint32_t idx) {
193  std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
194  uint32_t num = GetNumCompileUnits();
195  if (idx >= num)
196    return nullptr;
197  lldb::CompUnitSP &cu_sp = (*m_compile_units)[idx];
198  if (!cu_sp)
199    cu_sp = ParseCompileUnitAtIndex(idx);
200  return cu_sp;
201}
202
203void SymbolFileCommon::SetCompileUnitAtIndex(uint32_t idx,
204                                             const CompUnitSP &cu_sp) {
205  std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
206  const size_t num_compile_units = GetNumCompileUnits();
207  assert(idx < num_compile_units);
208  UNUSED_IF_ASSERT_DISABLED(num_compile_units);
209
210  // Fire off an assertion if this compile unit already exists for now. The
211  // partial parsing should take care of only setting the compile unit
212  // once, so if this assertion fails, we need to make sure that we don't
213  // have a race condition, or have a second parse of the same compile
214  // unit.
215  assert((*m_compile_units)[idx] == nullptr);
216  (*m_compile_units)[idx] = cu_sp;
217}
218
219llvm::Expected<TypeSystemSP>
220SymbolFileCommon::GetTypeSystemForLanguage(lldb::LanguageType language) {
221  auto type_system_or_err =
222      m_objfile_sp->GetModule()->GetTypeSystemForLanguage(language);
223  if (type_system_or_err) {
224    if (auto ts = *type_system_or_err)
225      ts->SetSymbolFile(this);
226  }
227  return type_system_or_err;
228}
229
230uint64_t SymbolFileCommon::GetDebugInfoSize() {
231  if (!m_objfile_sp)
232    return 0;
233  ModuleSP module_sp(m_objfile_sp->GetModule());
234  if (!module_sp)
235    return 0;
236  const SectionList *section_list = module_sp->GetSectionList();
237  if (section_list)
238    return section_list->GetDebugInfoSize();
239  return 0;
240}
241
242void SymbolFileCommon::Dump(Stream &s) {
243  s.Format("SymbolFile {0} ({1})\n", GetPluginName(),
244           GetMainObjectFile()->GetFileSpec());
245  s.PutCString("Types:\n");
246  m_type_list.Dump(&s, /*show_context*/ false);
247  s.PutChar('\n');
248
249  s.PutCString("Compile units:\n");
250  if (m_compile_units) {
251    for (const CompUnitSP &cu_sp : *m_compile_units) {
252      // We currently only dump the compile units that have been parsed
253      if (cu_sp)
254        cu_sp->Dump(&s, /*show_context*/ false);
255    }
256  }
257  s.PutChar('\n');
258
259  if (Symtab *symtab = GetSymtab())
260    symtab->Dump(&s, nullptr, eSortOrderNone);
261}
262