llvm-project

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//===-- SymbolFile.cpp ----------------------------------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#include "lldb/Symbol/SymbolFile.h"
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#include "lldb/Core/Module.h"
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#include "lldb/Core/PluginManager.h"
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#include "lldb/Symbol/CompileUnit.h"
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#include "lldb/Symbol/ObjectFile.h"
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#include "lldb/Symbol/SymbolFileOnDemand.h"
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#include "lldb/Symbol/TypeMap.h"
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#include "lldb/Symbol/TypeSystem.h"
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#include "lldb/Symbol/VariableList.h"
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#include "lldb/Utility/Log.h"
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#include "lldb/Utility/StreamString.h"
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#include "lldb/Utility/StructuredData.h"
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#include "lldb/lldb-private.h"
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#include <future>
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using namespace lldb_private;
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using namespace lldb;
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char SymbolFile::ID;
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char SymbolFileCommon::ID;
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void SymbolFile::PreloadSymbols() {
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  // No-op for most implementations.
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}
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std::recursive_mutex &SymbolFile::GetModuleMutex() const {
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  return GetObjectFile()->GetModule()->GetMutex();
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}
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SymbolFile *SymbolFile::FindPlugin(ObjectFileSP objfile_sp) {
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  std::unique_ptr<SymbolFile> best_symfile_up;
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  if (objfile_sp != nullptr) {
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    // We need to test the abilities of this section list. So create what it
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    // would be with this new objfile_sp.
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    lldb::ModuleSP module_sp(objfile_sp->GetModule());
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    if (module_sp) {
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      // Default to the main module section list.
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      ObjectFile *module_obj_file = module_sp->GetObjectFile();
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      if (module_obj_file != objfile_sp.get()) {
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        // Make sure the main object file's sections are created
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        module_obj_file->GetSectionList();
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        objfile_sp->CreateSections(*module_sp->GetUnifiedSectionList());
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      }
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    }
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    // TODO: Load any plug-ins in the appropriate plug-in search paths and
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    // iterate over all of them to find the best one for the job.
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    uint32_t best_symfile_abilities = 0;
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    SymbolFileCreateInstance create_callback;
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    for (uint32_t idx = 0;
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         (create_callback = PluginManager::GetSymbolFileCreateCallbackAtIndex(
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              idx)) != nullptr;
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         ++idx) {
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      std::unique_ptr<SymbolFile> curr_symfile_up(create_callback(objfile_sp));
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      if (curr_symfile_up) {
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        const uint32_t sym_file_abilities = curr_symfile_up->GetAbilities();
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        if (sym_file_abilities > best_symfile_abilities) {
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          best_symfile_abilities = sym_file_abilities;
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          best_symfile_up.reset(curr_symfile_up.release());
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          // If any symbol file parser has all of the abilities, then we should
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          // just stop looking.
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          if ((kAllAbilities & sym_file_abilities) == kAllAbilities)
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            break;
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        }
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      }
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    }
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    if (best_symfile_up) {
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      // If symbol on-demand is enabled the winning symbol file parser is
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      // wrapped with SymbolFileOnDemand so that hydration of the debug info
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      // can be controlled to improve performance.
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      //
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      // Currently the supported on-demand symbol files include:
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      //  executables, shared libraries and debug info files.
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      //
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      // To reduce unnecessary wrapping files with zero debug abilities are
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      // skipped.
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      ObjectFile::Type obj_file_type = objfile_sp->CalculateType();
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      if (ModuleList::GetGlobalModuleListProperties().GetLoadSymbolOnDemand() &&
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          best_symfile_abilities > 0 &&
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          (obj_file_type == ObjectFile::eTypeExecutable ||
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           obj_file_type == ObjectFile::eTypeSharedLibrary ||
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           obj_file_type == ObjectFile::eTypeDebugInfo)) {
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        best_symfile_up =
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            std::make_unique<SymbolFileOnDemand>(std::move(best_symfile_up));
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      }
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      // Let the winning symbol file parser initialize itself more completely
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      // now that it has been chosen
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      best_symfile_up->InitializeObject();
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    }
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  }
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  return best_symfile_up.release();
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}
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uint32_t
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SymbolFile::ResolveSymbolContext(const SourceLocationSpec &src_location_spec,
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                                 lldb::SymbolContextItem resolve_scope,
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                                 SymbolContextList &sc_list) {
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  return 0;
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}
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void SymbolFile::FindGlobalVariables(ConstString name,
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                                     const CompilerDeclContext &parent_decl_ctx,
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                                     uint32_t max_matches,
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                                     VariableList &variables) {}
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void SymbolFile::FindGlobalVariables(const RegularExpression &regex,
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                                     uint32_t max_matches,
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                                     VariableList &variables) {}
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void SymbolFile::FindFunctions(const Module::LookupInfo &lookup_info,
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                               const CompilerDeclContext &parent_decl_ctx,
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                               bool include_inlines,
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                               SymbolContextList &sc_list) {}
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void SymbolFile::FindFunctions(const RegularExpression &regex,
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                               bool include_inlines,
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                               SymbolContextList &sc_list) {}
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void SymbolFile::GetMangledNamesForFunction(
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    const std::string &scope_qualified_name,
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    std::vector<ConstString> &mangled_names) {}
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void SymbolFile::AssertModuleLock() {
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  // The code below is too expensive to leave enabled in release builds. It's
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  // enabled in debug builds or when the correct macro is set.
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#if defined(LLDB_CONFIGURATION_DEBUG)
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  // We assert that we have to module lock by trying to acquire the lock from a
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  // different thread. Note that we must abort if the result is true to
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  // guarantee correctness.
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  assert(std::async(
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             std::launch::async,
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             [this] {
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               return this->GetModuleMutex().try_lock();
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             }).get() == false &&
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         "Module is not locked");
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#endif
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}
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SymbolFile::RegisterInfoResolver::~RegisterInfoResolver() = default;
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Symtab *SymbolFileCommon::GetSymtab() {
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  std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
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  // Fetch the symtab from the main object file.
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  auto *symtab = GetMainObjectFile()->GetSymtab();
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  if (m_symtab != symtab) {
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    m_symtab = symtab;
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    // Then add our symbols to it.
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    if (m_symtab)
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      AddSymbols(*m_symtab);
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  }
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  return m_symtab;
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}
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ObjectFile *SymbolFileCommon::GetMainObjectFile() {
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  return m_objfile_sp->GetModule()->GetObjectFile();
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}
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void SymbolFileCommon::SectionFileAddressesChanged() {
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  ObjectFile *module_objfile = GetMainObjectFile();
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  ObjectFile *symfile_objfile = GetObjectFile();
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  if (symfile_objfile != module_objfile)
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    symfile_objfile->SectionFileAddressesChanged();
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  if (auto *symtab = GetSymtab())
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    symtab->SectionFileAddressesChanged();
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}
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uint32_t SymbolFileCommon::GetNumCompileUnits() {
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  std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
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  if (!m_compile_units) {
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    // Create an array of compile unit shared pointers -- which will each
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    // remain NULL until someone asks for the actual compile unit information.
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    m_compile_units.emplace(CalculateNumCompileUnits());
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  }
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  return m_compile_units->size();
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}
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CompUnitSP SymbolFileCommon::GetCompileUnitAtIndex(uint32_t idx) {
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  std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
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  uint32_t num = GetNumCompileUnits();
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  if (idx >= num)
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    return nullptr;
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  lldb::CompUnitSP &cu_sp = (*m_compile_units)[idx];
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  if (!cu_sp)
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    cu_sp = ParseCompileUnitAtIndex(idx);
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  return cu_sp;
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}
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void SymbolFileCommon::SetCompileUnitAtIndex(uint32_t idx,
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                                             const CompUnitSP &cu_sp) {
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  std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
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  const size_t num_compile_units = GetNumCompileUnits();
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  assert(idx < num_compile_units);
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  UNUSED_IF_ASSERT_DISABLED(num_compile_units);
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  // Fire off an assertion if this compile unit already exists for now. The
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  // partial parsing should take care of only setting the compile unit
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  // once, so if this assertion fails, we need to make sure that we don't
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  // have a race condition, or have a second parse of the same compile
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  // unit.
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  assert((*m_compile_units)[idx] == nullptr);
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  (*m_compile_units)[idx] = cu_sp;
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}
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llvm::Expected<TypeSystemSP>
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SymbolFileCommon::GetTypeSystemForLanguage(lldb::LanguageType language) {
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  auto type_system_or_err =
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      m_objfile_sp->GetModule()->GetTypeSystemForLanguage(language);
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  if (type_system_or_err) {
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    if (auto ts = *type_system_or_err)
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      ts->SetSymbolFile(this);
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  }
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  return type_system_or_err;
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}
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uint64_t SymbolFileCommon::GetDebugInfoSize(bool load_all_debug_info) {
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  if (!m_objfile_sp)
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    return 0;
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  ModuleSP module_sp(m_objfile_sp->GetModule());
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  if (!module_sp)
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    return 0;
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  const SectionList *section_list = module_sp->GetSectionList();
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  if (section_list)
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    return section_list->GetDebugInfoSize();
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  return 0;
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}
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void SymbolFileCommon::Dump(Stream &s) {
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  s.Format("SymbolFile {0} ({1})\n", GetPluginName(),
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           GetMainObjectFile()->GetFileSpec());
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  s.PutCString("Types:\n");
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  m_type_list.Dump(&s, /*show_context*/ false);
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  s.PutChar('\n');
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  s.PutCString("Compile units:\n");
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  if (m_compile_units) {
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    for (const CompUnitSP &cu_sp : *m_compile_units) {
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      // We currently only dump the compile units that have been parsed
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      if (cu_sp)
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        cu_sp->Dump(&s, /*show_context*/ false);
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    }
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  }
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  s.PutChar('\n');
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  if (Symtab *symtab = GetSymtab())
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    symtab->Dump(&s, nullptr, eSortOrderNone);
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}
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