https://github.com/satyajanga updated https://github.com/llvm/llvm-project/pull/218030
>From c4f4e4afdd2446de6235a6e08269ed44dd0c4d14 Mon Sep 17 00:00:00 2001 From: satya janga <[email protected]> Date: Fri, 21 Aug 2026 13:55:59 -0700 Subject: [PATCH] [lldb] Prefer readers with detailed debug information Add a Symbols ability for object-file symbol data and make SymbolFileSymtab advertise it instead of claiming full Functions or GlobalVariables. Order the ability bits so the existing numeric comparison prefers richer debug information. In particular, CompileUnits plus LineTables outranks Symbols plus CompileUnits. Add focused coverage for plugin selection and SymbolFileSymtab abilities. --- lldb/include/lldb/Symbol/SymbolFile.h | 24 +++--- .../SymbolFile/Symtab/SymbolFileSymtab.cpp | 13 ++-- lldb/unittests/Symbol/LineTableTest.cpp | 77 ++++++++++++++++--- lldb/unittests/Symbol/SymtabTest.cpp | 5 ++ 4 files changed, 94 insertions(+), 25 deletions(-) diff --git a/lldb/include/lldb/Symbol/SymbolFile.h b/lldb/include/lldb/Symbol/SymbolFile.h index ae6504c016d7b..932c19f3cda9c 100644 --- a/lldb/include/lldb/Symbol/SymbolFile.h +++ b/lldb/include/lldb/Symbol/SymbolFile.h @@ -64,16 +64,22 @@ class SymbolFile : public PluginInterface { // Each symbol file can claim to support one or more symbol file abilities. // These get returned from SymbolFile::GetAbilities(). These help us to // determine which plug-in will be best to load the debug information found - // in files. + // in files. The values are ordered so that a simple numeric comparison + // prefers detailed debug information over data read directly from an object + // file's symbol table. enum Abilities { - CompileUnits = (1u << 0), - LineTables = (1u << 1), - Functions = (1u << 2), - Blocks = (1u << 3), - GlobalVariables = (1u << 4), - LocalVariables = (1u << 5), - VariableTypes = (1u << 6), - kAllAbilities = ((1u << 7) - 1u) + Symbols = (1u << 0), + CompileUnits = (1u << 1), + LineTables = (1u << 2), + Functions = (1u << 3), + Blocks = (1u << 4), + GlobalVariables = (1u << 5), + LocalVariables = (1u << 6), + VariableTypes = (1u << 7), + // All detailed debug-information abilities. Symbols is excluded because + // it describes information from the object file's symbol table. + kAllAbilities = CompileUnits | LineTables | Functions | Blocks | + GlobalVariables | LocalVariables | VariableTypes }; static SymbolFile *FindPlugin(lldb::ObjectFileSP objfile_sp); diff --git a/lldb/source/Plugins/SymbolFile/Symtab/SymbolFileSymtab.cpp b/lldb/source/Plugins/SymbolFile/Symtab/SymbolFileSymtab.cpp index 9c298374101fa..57fe9090aa694 100644 --- a/lldb/source/Plugins/SymbolFile/Symtab/SymbolFileSymtab.cpp +++ b/lldb/source/Plugins/SymbolFile/Symtab/SymbolFileSymtab.cpp @@ -60,9 +60,13 @@ uint32_t SymbolFileSymtab::CalculateAbilities() { if (m_objfile_sp) { const Symtab *symtab = m_objfile_sp->GetSymtab(); if (symtab) { - // The snippet of code below will get the indexes the module symbol table - // entries that are code, data, or function related (debug info), sort - // them by value (address) and dump the sorted symbols. + // Get the indexes of source, code, data, and function-related entries in + // the module symbol table. Only source-file entries provide a genuine + // debug-info ability. Code and data entries remain available as symbols + // but are not equivalent to debug-info functions or global variables. + if (symtab->GetNumSymbols() > 0) + abilities |= Symbols; + if (symtab->AppendSymbolIndexesWithType(eSymbolTypeSourceFile, m_source_indexes)) { abilities |= CompileUnits; @@ -72,20 +76,17 @@ uint32_t SymbolFileSymtab::CalculateAbilities() { eSymbolTypeCode, Symtab::eDebugYes, Symtab::eVisibilityAny, m_func_indexes)) { symtab->SortSymbolIndexesByValue(m_func_indexes, true); - abilities |= Functions; } if (symtab->AppendSymbolIndexesWithType(eSymbolTypeCode, Symtab::eDebugNo, Symtab::eVisibilityAny, m_code_indexes)) { symtab->SortSymbolIndexesByValue(m_code_indexes, true); - abilities |= Functions; } if (symtab->AppendSymbolIndexesWithType(eSymbolTypeData, m_data_indexes)) { symtab->SortSymbolIndexesByValue(m_data_indexes, true); - abilities |= GlobalVariables; } lldb_private::Symtab::IndexCollection objc_class_indexes; diff --git a/lldb/unittests/Symbol/LineTableTest.cpp b/lldb/unittests/Symbol/LineTableTest.cpp index 80f2f219d0e81..291b1bb356813 100644 --- a/lldb/unittests/Symbol/LineTableTest.cpp +++ b/lldb/unittests/Symbol/LineTableTest.cpp @@ -35,10 +35,22 @@ class FakeSymbolFile : public SymbolFile { /// \} static void Initialize() { - PluginManager::RegisterPlugin("FakeSymbolFile", "", CreateInstance, - DebuggerInitialize); + PluginManager::RegisterPlugin("LineTableFakeSymbolFile", "", + CreateLineTableInstance, DebuggerInitialize); + PluginManager::RegisterPlugin("SymbolOnlyFakeSymbolFile", "", + CreateSymbolOnlyInstance, DebuggerInitialize); + } + static void Terminate() { + PluginManager::UnregisterPlugin(CreateSymbolOnlyInstance); + PluginManager::UnregisterPlugin(CreateLineTableInstance); + } + + static void SetLineTableAbilities(uint32_t abilities) { + g_line_table_abilities = abilities; + } + static void SetSymbolAbilities(uint32_t abilities) { + g_symbol_abilities = abilities; } - static void Terminate() { PluginManager::UnregisterPlugin(CreateInstance); } void InjectCompileUnit(std::unique_ptr<CompileUnit> cu_up) { m_cu_sp = std::move(cu_up); @@ -48,14 +60,19 @@ class FakeSymbolFile : public SymbolFile { /// LLVM RTTI support. static char ID; - static SymbolFile *CreateInstance(ObjectFileSP objfile_sp) { - return new FakeSymbolFile(std::move(objfile_sp)); + static SymbolFile *CreateLineTableInstance(ObjectFileSP objfile_sp) { + return new FakeSymbolFile(std::move(objfile_sp), "LineTableFakeSymbolFile", + g_line_table_abilities); + } + static SymbolFile *CreateSymbolOnlyInstance(ObjectFileSP objfile_sp) { + return new FakeSymbolFile(std::move(objfile_sp), "SymbolOnlyFakeSymbolFile", + g_symbol_abilities); } static void DebuggerInitialize(Debugger &) {} - StringRef GetPluginName() override { return "FakeSymbolFile"; } - uint32_t GetAbilities() override { return UINT32_MAX; } - uint32_t CalculateAbilities() override { return UINT32_MAX; } + StringRef GetPluginName() override { return m_plugin_name; } + uint32_t GetAbilities() override { return m_abilities; } + uint32_t CalculateAbilities() override { return m_abilities; } uint32_t GetNumCompileUnits() override { return 1; } CompUnitSP GetCompileUnitAtIndex(uint32_t) override { return m_cu_sp; } Symtab *GetSymtab(bool can_create = true) override { return nullptr; } @@ -109,11 +126,17 @@ class FakeSymbolFile : public SymbolFile { } TypeSP CopyType(const TypeSP &) override { return nullptr; } - FakeSymbolFile(ObjectFileSP objfile_sp) - : m_objfile_sp(std::move(objfile_sp)) {} + FakeSymbolFile(ObjectFileSP objfile_sp, StringRef plugin_name, + uint32_t abilities) + : m_objfile_sp(std::move(objfile_sp)), m_plugin_name(plugin_name), + m_abilities(abilities) {} ObjectFileSP m_objfile_sp; CompUnitSP m_cu_sp; + StringRef m_plugin_name; + uint32_t m_abilities; + inline static uint32_t g_line_table_abilities = CompileUnits | LineTables; + inline static uint32_t g_symbol_abilities = Symbols; }; struct FakeModuleFixture { @@ -124,6 +147,14 @@ struct FakeModuleFixture { }; class LineTableTest : public testing::Test { +protected: + void SetUp() override { + FakeSymbolFile::SetLineTableAbilities(SymbolFile::CompileUnits | + SymbolFile::LineTables); + FakeSymbolFile::SetSymbolAbilities(SymbolFile::Symbols); + } + +private: SubsystemRAII<ObjectFileELF, FakeSymbolFile> subsystems; }; @@ -190,6 +221,32 @@ CreateFakeModule(std::vector<LineTable::Sequence> line_sequences) { std::move(text_sp), line_table}; } +TEST_F(LineTableTest, FindPluginPrefersLineTablesWithCompileUnits) { + llvm::Expected<FakeModuleFixture> fixture = CreateFakeModule({}); + ASSERT_THAT_EXPECTED(fixture, llvm::Succeeded()); + + SymbolFile *symbol_file = fixture->module_sp->GetSymbolFile(); + ASSERT_NE(symbol_file, nullptr); + EXPECT_EQ(symbol_file->GetPluginName(), "LineTableFakeSymbolFile"); + EXPECT_EQ( + symbol_file->GetAbilities(), + static_cast<uint32_t>(SymbolFile::CompileUnits | SymbolFile::LineTables)); +} + +TEST_F(LineTableTest, FindPluginPrefersLineTablesOverCompileUnits) { + FakeSymbolFile::SetSymbolAbilities(SymbolFile::Symbols | + SymbolFile::CompileUnits); + llvm::Expected<FakeModuleFixture> fixture = CreateFakeModule({}); + ASSERT_THAT_EXPECTED(fixture, llvm::Succeeded()); + + SymbolFile *symbol_file = fixture->module_sp->GetSymbolFile(); + ASSERT_NE(symbol_file, nullptr); + EXPECT_EQ(symbol_file->GetPluginName(), "LineTableFakeSymbolFile"); + EXPECT_EQ( + symbol_file->GetAbilities(), + static_cast<uint32_t>(SymbolFile::CompileUnits | SymbolFile::LineTables)); +} + TEST_F(LineTableTest, lower_bound) { LineSequenceBuilder builder; builder.Entry(0); diff --git a/lldb/unittests/Symbol/SymtabTest.cpp b/lldb/unittests/Symbol/SymtabTest.cpp index fda92e4044919..dba75c0f6e1f6 100644 --- a/lldb/unittests/Symbol/SymtabTest.cpp +++ b/lldb/unittests/Symbol/SymtabTest.cpp @@ -739,6 +739,11 @@ TEST_F(SymtabTest, TestSymbolFileCreatedOnDemand) { // And we should be able to get it again once it has been created. Symtab *cached_module_symtab = module_sp->GetSymtab(/*can_create=*/false); ASSERT_EQ(module_symtab, cached_module_symtab); + + SymbolFile *symbol_file = module_sp->GetSymbolFile(); + ASSERT_NE(symbol_file, nullptr); + EXPECT_EQ(symbol_file->GetAbilities(), + static_cast<uint32_t>(SymbolFile::Symbols)); } TEST_F(SymtabTest, TestSymbolTableCreatedOnDemand) { _______________________________________________ lldb-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
