//===-- ItaniumABILanguageRuntime.cpp --------------------------------------*- C++ -*-===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// #include "ItaniumABILanguageRuntime.h" #include "lldb/Breakpoint/BreakpointLocation.h" #include "lldb/Core/ConstString.h" #include "lldb/Core/Error.h" #include "lldb/Core/Log.h" #include "lldb/Core/Mangled.h" #include "lldb/Core/Module.h" #include "lldb/Core/PluginManager.h" #include "lldb/Core/Scalar.h" #include "lldb/Core/ValueObject.h" #include "lldb/Core/ValueObjectMemory.h" #include "lldb/Interpreter/CommandObject.h" #include "lldb/Interpreter/CommandObjectMultiword.h" #include "lldb/Interpreter/CommandReturnObject.h" #include "lldb/Symbol/ClangASTContext.h" #include "lldb/Symbol/Symbol.h" #include "lldb/Symbol/SymbolFile.h" #include "lldb/Symbol/TypeList.h" #include "lldb/Target/Process.h" #include "lldb/Target/RegisterContext.h" #include "lldb/Target/SectionLoadList.h" #include "lldb/Target/StopInfo.h" #include "lldb/Target/Target.h" #include "lldb/Target/Thread.h" #include using namespace lldb; using namespace lldb_private; static const char *vtable_demangled_prefix = "vtable for "; bool ItaniumABILanguageRuntime::CouldHaveDynamicValue (ValueObject &in_value) { const bool check_cxx = true; const bool check_objc = false; return in_value.GetCompilerType().IsPossibleDynamicType (NULL, check_cxx, check_objc); } TypeAndOrName ItaniumABILanguageRuntime::GetTypeInfoFromVTableAddress(ValueObject &in_value, lldb::addr_t original_ptr, lldb::addr_t vtable_load_addr) { if (m_process && vtable_load_addr != LLDB_INVALID_ADDRESS) { // Find the symbol that contains the "vtable_load_addr" address Address vtable_addr; Target &target = m_process->GetTarget(); if (!target.GetSectionLoadList().IsEmpty()) { if (target.GetSectionLoadList().ResolveLoadAddress(vtable_load_addr, vtable_addr)) { // See if we have cached info for this type already TypeAndOrName type_info = GetDynamicTypeInfo(vtable_addr); if (type_info) return type_info; SymbolContext sc; target.GetImages().ResolveSymbolContextForAddress(vtable_addr, eSymbolContextSymbol, sc); Symbol *symbol = sc.symbol; if (symbol != NULL) { const char *name = symbol->GetMangled().GetDemangledName(lldb::eLanguageTypeC_plus_plus).AsCString(); if (name && strstr(name, vtable_demangled_prefix) == name) { Log *log (lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_OBJECT)); if (log) log->Printf ("0x%16.16" PRIx64 ": static-type = '%s' has vtable symbol '%s'\n", original_ptr, in_value.GetTypeName().GetCString(), name); // We are a C++ class, that's good. Get the class name and look it up: const char *class_name = name + strlen(vtable_demangled_prefix); type_info.SetName(class_name); const bool exact_match = true; TypeList class_types; uint32_t num_matches = 0; // First look in the module that the vtable symbol came from // and look for a single exact match. llvm::DenseSet searched_symbol_files; if (sc.module_sp) { num_matches = sc.module_sp->FindTypes (sc, ConstString(class_name), exact_match, 1, searched_symbol_files, class_types); } // If we didn't find a symbol, then move on to the entire // module list in the target and get as many unique matches // as possible if (num_matches == 0) { num_matches = target.GetImages().FindTypes(sc, ConstString(class_name), exact_match, UINT32_MAX, searched_symbol_files, class_types); } lldb::TypeSP type_sp; if (num_matches == 0) { if (log) log->Printf("0x%16.16" PRIx64 ": is not dynamic\n", original_ptr); return TypeAndOrName(); } if (num_matches == 1) { type_sp = class_types.GetTypeAtIndex(0); if (type_sp) { if (ClangASTContext::IsCXXClassType(type_sp->GetForwardCompilerType())) { if (log) log->Printf("0x%16.16" PRIx64 ": static-type = '%s' has dynamic type: uid={0x%" PRIx64 "}, type-name='%s'\n", original_ptr, in_value.GetTypeName().AsCString(), type_sp->GetID(), type_sp->GetName().GetCString()); type_info.SetTypeSP(type_sp); } } } else if (num_matches > 1) { size_t i; if (log) { for (i = 0; i < num_matches; i++) { type_sp = class_types.GetTypeAtIndex(i); if (type_sp) { if (log) log->Printf ("0x%16.16" PRIx64 ": static-type = '%s' has multiple matching dynamic types: uid={0x%" PRIx64 "}, type-name='%s'\n", original_ptr, in_value.GetTypeName().AsCString(), type_sp->GetID(), type_sp->GetName().GetCString()); } } } for (i = 0; i < num_matches; i++) { type_sp = class_types.GetTypeAtIndex(i); if (type_sp) { if (ClangASTContext::IsCXXClassType(type_sp->GetForwardCompilerType())) { if (log) log->Printf ("0x%16.16" PRIx64 ": static-type = '%s' has multiple matching dynamic types, picking this one: uid={0x%" PRIx64 "}, type-name='%s'\n", original_ptr, in_value.GetTypeName().AsCString(), type_sp->GetID(), type_sp->GetName().GetCString()); type_info.SetTypeSP(type_sp); } } } if (log && i == num_matches) { log->Printf("0x%16.16" PRIx64 ": static-type = '%s' has multiple matching dynamic " "types, didn't find a C++ match\n", original_ptr, in_value.GetTypeName().AsCString()); } } if (type_info) SetDynamicTypeInfo(vtable_addr, type_info); return type_info; } } } } } return TypeAndOrName(); } bool ItaniumABILanguageRuntime::GetDynamicTypeAndAddress(ValueObject &in_value, lldb::DynamicValueType use_dynamic, TypeAndOrName &class_type_or_name, Address &dynamic_address, Value::ValueType &value_type) { // For Itanium, if the type has a vtable pointer in the object, it will be at offset 0 // in the object. That will point to the "address point" within the vtable (not the beginning of the // vtable.) We can then look up the symbol containing this "address point" and that symbol's name // demangled will contain the full class name. // The second pointer above the "address point" is the "offset_to_top". We'll use that to get the // start of the value object which holds the dynamic type. // class_type_or_name.Clear(); value_type = Value::ValueType::eValueTypeScalar; // Only a pointer or reference type can have a different dynamic and static type: if (CouldHaveDynamicValue(in_value)) { // First job, pull out the address at 0 offset from the object. AddressType address_type; lldb::addr_t original_ptr = in_value.GetPointerValue(&address_type); if (original_ptr == LLDB_INVALID_ADDRESS) return false; ExecutionContext exe_ctx(in_value.GetExecutionContextRef()); Process *process = exe_ctx.GetProcessPtr(); if (process == nullptr) return false; Error error; const lldb::addr_t vtable_address_point = process->ReadPointerFromMemory(original_ptr, error); if (!error.Success() || vtable_address_point == LLDB_INVALID_ADDRESS) { return false; } class_type_or_name = GetTypeInfoFromVTableAddress(in_value, original_ptr, vtable_address_point); if (class_type_or_name) { TypeSP type_sp = class_type_or_name.GetTypeSP(); // There can only be one type with a given name, // so we've just found duplicate definitions, and this // one will do as well as any other. // We don't consider something to have a dynamic type if // it is the same as the static type. So compare against // the value we were handed. if (type_sp) { if (ClangASTContext::AreTypesSame(in_value.GetCompilerType(), type_sp->GetForwardCompilerType())) { // The dynamic type we found was the same type, // so we don't have a dynamic type here... return false; } // The offset_to_top is two pointers above the vtable pointer. const uint32_t addr_byte_size = process->GetAddressByteSize(); const lldb::addr_t offset_to_top_location = vtable_address_point - 2 * addr_byte_size; // Watch for underflow, offset_to_top_location should be less than vtable_address_point if (offset_to_top_location >= vtable_address_point) return false; const int64_t offset_to_top = process->ReadSignedIntegerFromMemory(offset_to_top_location, addr_byte_size, INT64_MIN, error); if (offset_to_top == INT64_MIN) return false; // So the dynamic type is a value that starts at offset_to_top // above the original address. lldb::addr_t dynamic_addr = original_ptr + offset_to_top; if (!process->GetTarget().GetSectionLoadList().ResolveLoadAddress(dynamic_addr, dynamic_address)) { dynamic_address.SetRawAddress(dynamic_addr); } return true; } } } return class_type_or_name.IsEmpty() == false; } TypeAndOrName ItaniumABILanguageRuntime::FixUpDynamicType(const TypeAndOrName& type_and_or_name, ValueObject& static_value) { CompilerType static_type(static_value.GetCompilerType()); Flags static_type_flags(static_type.GetTypeInfo()); TypeAndOrName ret(type_and_or_name); if (type_and_or_name.HasType()) { // The type will always be the type of the dynamic object. If our parent's type was a pointer, // then our type should be a pointer to the type of the dynamic object. If a reference, then the original type // should be okay... CompilerType orig_type = type_and_or_name.GetCompilerType(); CompilerType corrected_type = orig_type; if (static_type_flags.AllSet(eTypeIsPointer)) corrected_type = orig_type.GetPointerType (); else if (static_type_flags.AllSet(eTypeIsReference)) corrected_type = orig_type.GetLValueReferenceType(); ret.SetCompilerType(corrected_type); } else { // If we are here we need to adjust our dynamic type name to include the correct & or * symbol std::string corrected_name (type_and_or_name.GetName().GetCString()); if (static_type_flags.AllSet(eTypeIsPointer)) corrected_name.append(" *"); else if (static_type_flags.AllSet(eTypeIsReference)) corrected_name.append(" &"); // the parent type should be a correctly pointer'ed or referenc'ed type ret.SetCompilerType(static_type); ret.SetName(corrected_name.c_str()); } return ret; } bool ItaniumABILanguageRuntime::IsVTableName (const char *name) { if (name == NULL) return false; // Can we maybe ask Clang about this? if (strstr (name, "_vptr$") == name) return true; else return false; } //------------------------------------------------------------------ // Static Functions //------------------------------------------------------------------ LanguageRuntime * ItaniumABILanguageRuntime::CreateInstance (Process *process, lldb::LanguageType language) { // FIXME: We have to check the process and make sure we actually know that this process supports // the Itanium ABI. if (language == eLanguageTypeC_plus_plus || language == eLanguageTypeC_plus_plus_03 || language == eLanguageTypeC_plus_plus_11 || language == eLanguageTypeC_plus_plus_14) return new ItaniumABILanguageRuntime (process); else return NULL; } class CommandObjectMultiwordItaniumABI_Demangle : public CommandObjectParsed { public: CommandObjectMultiwordItaniumABI_Demangle (CommandInterpreter &interpreter) : CommandObjectParsed (interpreter, "demangle", "Demangle a C++ mangled name.", "language cplusplus demangle") { CommandArgumentEntry arg; CommandArgumentData index_arg; // Define the first (and only) variant of this arg. index_arg.arg_type = eArgTypeSymbol; index_arg.arg_repetition = eArgRepeatPlus; // There is only one variant this argument could be; put it into the argument entry. arg.push_back (index_arg); // Push the data for the first argument into the m_arguments vector. m_arguments.push_back (arg); } ~CommandObjectMultiwordItaniumABI_Demangle() override = default; protected: bool DoExecute(Args& command, CommandReturnObject &result) override { bool demangled_any = false; bool error_any = false; for (size_t i = 0; i < command.GetArgumentCount(); i++) { auto arg = command.GetArgumentAtIndex(i); if (arg && *arg) { ConstString mangled_cs(arg); // the actual Mangled class should be strict about this, but on the command line // if you're copying mangled names out of 'nm' on Darwin, they will come out with // an extra underscore - be willing to strip this on behalf of the user // This is the moral equivalent of the -_/-n options to c++filt if (mangled_cs.GetStringRef().startswith("__Z")) mangled_cs.SetCString(arg+1); Mangled mangled(mangled_cs, true); if (mangled.GuessLanguage() == lldb::eLanguageTypeC_plus_plus) { ConstString demangled(mangled.GetDisplayDemangledName(lldb::eLanguageTypeC_plus_plus)); demangled_any = true; result.AppendMessageWithFormat("%s ---> %s\n", arg, demangled.GetCString()); } else { error_any = true; result.AppendErrorWithFormat("%s is not a valid C++ mangled name\n", arg); } } } result.SetStatus(error_any ? lldb::eReturnStatusFailed : (demangled_any ? lldb::eReturnStatusSuccessFinishResult : lldb::eReturnStatusSuccessFinishNoResult)); return result.Succeeded(); } }; class CommandObjectMultiwordItaniumABI : public CommandObjectMultiword { public: CommandObjectMultiwordItaniumABI (CommandInterpreter &interpreter) : CommandObjectMultiword (interpreter, "cplusplus", "A set of commands for operating on the C++ Language Runtime.", "cplusplus []") { LoadSubCommand ("demangle", CommandObjectSP (new CommandObjectMultiwordItaniumABI_Demangle (interpreter))); } ~CommandObjectMultiwordItaniumABI() override = default; }; void ItaniumABILanguageRuntime::Initialize() { PluginManager::RegisterPlugin (GetPluginNameStatic(), "Itanium ABI for the C++ language", CreateInstance, [] (CommandInterpreter& interpreter) -> lldb::CommandObjectSP { return CommandObjectSP(new CommandObjectMultiwordItaniumABI(interpreter)); }); } void ItaniumABILanguageRuntime::Terminate() { PluginManager::UnregisterPlugin (CreateInstance); } lldb_private::ConstString ItaniumABILanguageRuntime::GetPluginNameStatic() { static ConstString g_name("itanium"); return g_name; } //------------------------------------------------------------------ // PluginInterface protocol //------------------------------------------------------------------ lldb_private::ConstString ItaniumABILanguageRuntime::GetPluginName() { return GetPluginNameStatic(); } uint32_t ItaniumABILanguageRuntime::GetPluginVersion() { return 1; } BreakpointResolverSP ItaniumABILanguageRuntime::CreateExceptionResolver (Breakpoint *bkpt, bool catch_bp, bool throw_bp) { return CreateExceptionResolver (bkpt, catch_bp, throw_bp, false); } BreakpointResolverSP ItaniumABILanguageRuntime::CreateExceptionResolver (Breakpoint *bkpt, bool catch_bp, bool throw_bp, bool for_expressions) { // One complication here is that most users DON'T want to stop at __cxa_allocate_expression, but until we can do // anything better with predicting unwinding the expression parser does. So we have two forms of the exception // breakpoints, one for expressions that leaves out __cxa_allocate_exception, and one that includes it. // The SetExceptionBreakpoints does the latter, the CreateExceptionBreakpoint in the runtime the former. static const char *g_catch_name = "__cxa_begin_catch"; static const char *g_throw_name1 = "__cxa_throw"; static const char *g_throw_name2 = "__cxa_rethrow"; static const char *g_exception_throw_name = "__cxa_allocate_exception"; std::vector exception_names; exception_names.reserve(4); if (catch_bp) exception_names.push_back(g_catch_name); if (throw_bp) { exception_names.push_back(g_throw_name1); exception_names.push_back(g_throw_name2); } if (for_expressions) exception_names.push_back(g_exception_throw_name); BreakpointResolverSP resolver_sp (new BreakpointResolverName (bkpt, exception_names.data(), exception_names.size(), eFunctionNameTypeBase, eLanguageTypeUnknown, 0, eLazyBoolNo)); return resolver_sp; } lldb::SearchFilterSP ItaniumABILanguageRuntime::CreateExceptionSearchFilter () { Target &target = m_process->GetTarget(); if (target.GetArchitecture().GetTriple().getVendor() == llvm::Triple::Apple) { // Limit the number of modules that are searched for these breakpoints for // Apple binaries. FileSpecList filter_modules; filter_modules.Append(FileSpec("libc++abi.dylib", false)); filter_modules.Append(FileSpec("libSystem.B.dylib", false)); return target.GetSearchFilterForModuleList(&filter_modules); } else { return LanguageRuntime::CreateExceptionSearchFilter(); } } lldb::BreakpointSP ItaniumABILanguageRuntime::CreateExceptionBreakpoint (bool catch_bp, bool throw_bp, bool for_expressions, bool is_internal) { Target &target = m_process->GetTarget(); FileSpecList filter_modules; BreakpointResolverSP exception_resolver_sp = CreateExceptionResolver (NULL, catch_bp, throw_bp, for_expressions); SearchFilterSP filter_sp (CreateExceptionSearchFilter ()); const bool hardware = false; const bool resolve_indirect_functions = false; return target.CreateBreakpoint (filter_sp, exception_resolver_sp, is_internal, hardware, resolve_indirect_functions); } void ItaniumABILanguageRuntime::SetExceptionBreakpoints () { if (!m_process) return; const bool catch_bp = false; const bool throw_bp = true; const bool is_internal = true; const bool for_expressions = true; // For the exception breakpoints set by the Expression parser, we'll be a little more aggressive and // stop at exception allocation as well. if (m_cxx_exception_bp_sp) { m_cxx_exception_bp_sp->SetEnabled (true); } else { m_cxx_exception_bp_sp = CreateExceptionBreakpoint (catch_bp, throw_bp, for_expressions, is_internal); if (m_cxx_exception_bp_sp) m_cxx_exception_bp_sp->SetBreakpointKind("c++ exception"); } } void ItaniumABILanguageRuntime::ClearExceptionBreakpoints () { if (!m_process) return; if (m_cxx_exception_bp_sp) { m_cxx_exception_bp_sp->SetEnabled (false); } } bool ItaniumABILanguageRuntime::ExceptionBreakpointsAreSet () { return m_cxx_exception_bp_sp && m_cxx_exception_bp_sp->IsEnabled(); } bool ItaniumABILanguageRuntime::ExceptionBreakpointsExplainStop (lldb::StopInfoSP stop_reason) { if (!m_process) return false; if (!stop_reason || stop_reason->GetStopReason() != eStopReasonBreakpoint) return false; uint64_t break_site_id = stop_reason->GetValue(); return m_process->GetBreakpointSiteList().BreakpointSiteContainsBreakpoint(break_site_id, m_cxx_exception_bp_sp->GetID()); } TypeAndOrName ItaniumABILanguageRuntime::GetDynamicTypeInfo(const lldb_private::Address &vtable_addr) { std::lock_guard locker(m_dynamic_type_map_mutex); DynamicTypeCache::const_iterator pos = m_dynamic_type_map.find(vtable_addr); if (pos == m_dynamic_type_map.end()) return TypeAndOrName(); else return pos->second; } void ItaniumABILanguageRuntime::SetDynamicTypeInfo(const lldb_private::Address &vtable_addr, const TypeAndOrName &type_info) { std::lock_guard locker(m_dynamic_type_map_mutex); m_dynamic_type_map[vtable_addr] = type_info; }