//===-- CommandObjectExpression.cpp ---------------------------------------===// // // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. // See https://llvm.org/LICENSE.txt for license information. // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception // //===----------------------------------------------------------------------===// #include "llvm/ADT/StringRef.h" #include "CommandObjectExpression.h" #include "lldb/Core/Debugger.h" #include "lldb/Expression/ExpressionVariable.h" #include "lldb/Expression/REPL.h" #include "lldb/Expression/UserExpression.h" #include "lldb/Host/OptionParser.h" #include "lldb/Interpreter/CommandInterpreter.h" #include "lldb/Interpreter/CommandOptionArgumentTable.h" #include "lldb/Interpreter/CommandReturnObject.h" #include "lldb/Interpreter/OptionArgParser.h" #include "lldb/Target/Language.h" #include "lldb/Target/Process.h" #include "lldb/Target/StackFrame.h" #include "lldb/Target/Target.h" #include "lldb/lldb-enumerations.h" #include "lldb/lldb-private-enumerations.h" using namespace lldb; using namespace lldb_private; CommandObjectExpression::CommandOptions::CommandOptions() = default; CommandObjectExpression::CommandOptions::~CommandOptions() = default; #define LLDB_OPTIONS_expression #include "CommandOptions.inc" Status CommandObjectExpression::CommandOptions::SetOptionValue( uint32_t option_idx, llvm::StringRef option_arg, ExecutionContext *execution_context) { Status error; const int short_option = GetDefinitions()[option_idx].short_option; switch (short_option) { case 'l': language = Language::GetLanguageTypeFromString(option_arg); if (language == eLanguageTypeUnknown) { StreamString sstr; sstr.Printf("unknown language type: '%s' for expression. " "List of supported languages:\n", option_arg.str().c_str()); Language::PrintSupportedLanguagesForExpressions(sstr, " ", "\n"); error.SetErrorString(sstr.GetString()); } break; case 'a': { bool success; bool result; result = OptionArgParser::ToBoolean(option_arg, true, &success); if (!success) error.SetErrorStringWithFormat( "invalid all-threads value setting: \"%s\"", option_arg.str().c_str()); else try_all_threads = result; } break; case 'i': { bool success; bool tmp_value = OptionArgParser::ToBoolean(option_arg, true, &success); if (success) ignore_breakpoints = tmp_value; else error.SetErrorStringWithFormat( "could not convert \"%s\" to a boolean value.", option_arg.str().c_str()); break; } case 'j': { bool success; bool tmp_value = OptionArgParser::ToBoolean(option_arg, true, &success); if (success) allow_jit = tmp_value; else error.SetErrorStringWithFormat( "could not convert \"%s\" to a boolean value.", option_arg.str().c_str()); break; } case 't': if (option_arg.getAsInteger(0, timeout)) { timeout = 0; error.SetErrorStringWithFormat("invalid timeout setting \"%s\"", option_arg.str().c_str()); } break; case 'u': { bool success; bool tmp_value = OptionArgParser::ToBoolean(option_arg, true, &success); if (success) unwind_on_error = tmp_value; else error.SetErrorStringWithFormat( "could not convert \"%s\" to a boolean value.", option_arg.str().c_str()); break; } case 'v': if (option_arg.empty()) { m_verbosity = eLanguageRuntimeDescriptionDisplayVerbosityFull; break; } m_verbosity = (LanguageRuntimeDescriptionDisplayVerbosity) OptionArgParser::ToOptionEnum( option_arg, GetDefinitions()[option_idx].enum_values, 0, error); if (!error.Success()) error.SetErrorStringWithFormat( "unrecognized value for description-verbosity '%s'", option_arg.str().c_str()); break; case 'g': debug = true; unwind_on_error = false; ignore_breakpoints = false; break; case 'p': top_level = true; break; case 'X': { bool success; bool tmp_value = OptionArgParser::ToBoolean(option_arg, true, &success); if (success) auto_apply_fixits = tmp_value ? eLazyBoolYes : eLazyBoolNo; else error.SetErrorStringWithFormat( "could not convert \"%s\" to a boolean value.", option_arg.str().c_str()); break; } case '\x01': { bool success; bool persist_result = OptionArgParser::ToBoolean(option_arg, true, &success); if (success) suppress_persistent_result = !persist_result ? eLazyBoolYes : eLazyBoolNo; else error.SetErrorStringWithFormat( "could not convert \"%s\" to a boolean value.", option_arg.str().c_str()); break; } default: llvm_unreachable("Unimplemented option"); } return error; } void CommandObjectExpression::CommandOptions::OptionParsingStarting( ExecutionContext *execution_context) { auto process_sp = execution_context ? execution_context->GetProcessSP() : ProcessSP(); if (process_sp) { ignore_breakpoints = process_sp->GetIgnoreBreakpointsInExpressions(); unwind_on_error = process_sp->GetUnwindOnErrorInExpressions(); } else { ignore_breakpoints = true; unwind_on_error = true; } show_summary = true; try_all_threads = true; timeout = 0; debug = false; language = eLanguageTypeUnknown; m_verbosity = eLanguageRuntimeDescriptionDisplayVerbosityCompact; auto_apply_fixits = eLazyBoolCalculate; top_level = false; allow_jit = true; suppress_persistent_result = eLazyBoolCalculate; } llvm::ArrayRef CommandObjectExpression::CommandOptions::GetDefinitions() { return llvm::ArrayRef(g_expression_options); } EvaluateExpressionOptions CommandObjectExpression::CommandOptions::GetEvaluateExpressionOptions( const Target &target, const OptionGroupValueObjectDisplay &display_opts) { EvaluateExpressionOptions options; options.SetCoerceToId(display_opts.use_objc); options.SetUnwindOnError(unwind_on_error); options.SetIgnoreBreakpoints(ignore_breakpoints); options.SetKeepInMemory(true); options.SetUseDynamic(display_opts.use_dynamic); options.SetTryAllThreads(try_all_threads); options.SetDebug(debug); options.SetLanguage(language); options.SetExecutionPolicy( allow_jit ? EvaluateExpressionOptions::default_execution_policy : lldb_private::eExecutionPolicyNever); bool auto_apply_fixits; if (this->auto_apply_fixits == eLazyBoolCalculate) auto_apply_fixits = target.GetEnableAutoApplyFixIts(); else auto_apply_fixits = this->auto_apply_fixits == eLazyBoolYes; options.SetAutoApplyFixIts(auto_apply_fixits); options.SetRetriesWithFixIts(target.GetNumberOfRetriesWithFixits()); if (top_level) options.SetExecutionPolicy(eExecutionPolicyTopLevel); // If there is any chance we are going to stop and want to see what went // wrong with our expression, we should generate debug info if (!ignore_breakpoints || !unwind_on_error) options.SetGenerateDebugInfo(true); if (timeout > 0) options.SetTimeout(std::chrono::microseconds(timeout)); else options.SetTimeout(std::nullopt); return options; } bool CommandObjectExpression::CommandOptions::ShouldSuppressResult( const OptionGroupValueObjectDisplay &display_opts) const { // Explicitly disabling persistent results takes precedence over the // m_verbosity/use_objc logic. if (suppress_persistent_result != eLazyBoolCalculate) return suppress_persistent_result == eLazyBoolYes; return display_opts.use_objc && m_verbosity == eLanguageRuntimeDescriptionDisplayVerbosityCompact; } CommandObjectExpression::CommandObjectExpression( CommandInterpreter &interpreter) : CommandObjectRaw(interpreter, "expression", "Evaluate an expression on the current " "thread. Displays any returned value " "with LLDB's default formatting.", "", eCommandProcessMustBePaused | eCommandTryTargetAPILock), IOHandlerDelegate(IOHandlerDelegate::Completion::Expression), m_format_options(eFormatDefault), m_repl_option(LLDB_OPT_SET_1, false, "repl", 'r', "Drop into REPL", false, true), m_expr_line_count(0) { SetHelpLong( R"( Single and multi-line expressions: )" " The expression provided on the command line must be a complete expression \ with no newlines. To evaluate a multi-line expression, \ hit a return after an empty expression, and lldb will enter the multi-line expression editor. \ Hit return on an empty line to end the multi-line expression." R"( Timeouts: )" " If the expression can be evaluated statically (without running code) then it will be. \ Otherwise, by default the expression will run on the current thread with a short timeout: \ currently .25 seconds. If it doesn't return in that time, the evaluation will be interrupted \ and resumed with all threads running. You can use the -a option to disable retrying on all \ threads. You can use the -t option to set a shorter timeout." R"( User defined variables: )" " You can define your own variables for convenience or to be used in subsequent expressions. \ You define them the same way you would define variables in C. If the first character of \ your user defined variable is a $, then the variable's value will be available in future \ expressions, otherwise it will just be available in the current expression." R"( Continuing evaluation after a breakpoint: )" " If the \"-i false\" option is used, and execution is interrupted by a breakpoint hit, once \ you are done with your investigation, you can either remove the expression execution frames \ from the stack with \"thread return -x\" or if you are still interested in the expression result \ you can issue the \"continue\" command and the expression evaluation will complete and the \ expression result will be available using the \"thread.completed-expression\" key in the thread \ format." R"( Examples: expr my_struct->a = my_array[3] expr -f bin -- (index * 8) + 5 expr unsigned int $foo = 5 expr char c[] = \"foo\"; c[0])"); AddSimpleArgumentList(eArgTypeExpression); // Add the "--format" and "--gdb-format" m_option_group.Append(&m_format_options, OptionGroupFormat::OPTION_GROUP_FORMAT | OptionGroupFormat::OPTION_GROUP_GDB_FMT, LLDB_OPT_SET_1); m_option_group.Append(&m_command_options); m_option_group.Append(&m_varobj_options, LLDB_OPT_SET_ALL, LLDB_OPT_SET_1 | LLDB_OPT_SET_2); m_option_group.Append(&m_repl_option, LLDB_OPT_SET_ALL, LLDB_OPT_SET_3); m_option_group.Finalize(); } CommandObjectExpression::~CommandObjectExpression() = default; Options *CommandObjectExpression::GetOptions() { return &m_option_group; } void CommandObjectExpression::HandleCompletion(CompletionRequest &request) { EvaluateExpressionOptions options; options.SetCoerceToId(m_varobj_options.use_objc); options.SetLanguage(m_command_options.language); options.SetExecutionPolicy(lldb_private::eExecutionPolicyNever); options.SetAutoApplyFixIts(false); options.SetGenerateDebugInfo(false); ExecutionContext exe_ctx(m_interpreter.GetExecutionContext()); // Get out before we start doing things that expect a valid frame pointer. if (exe_ctx.GetFramePtr() == nullptr) return; Target *exe_target = exe_ctx.GetTargetPtr(); Target &target = exe_target ? *exe_target : GetDummyTarget(); unsigned cursor_pos = request.GetRawCursorPos(); // Get the full user input including the suffix. The suffix is necessary // as OptionsWithRaw will use it to detect if the cursor is cursor is in the // argument part of in the raw input part of the arguments. If we cut of // of the suffix then "expr -arg[cursor] --" would interpret the "-arg" as // the raw input (as the "--" is hidden in the suffix). llvm::StringRef code = request.GetRawLineWithUnusedSuffix(); const std::size_t original_code_size = code.size(); // Remove the first token which is 'expr' or some alias/abbreviation of that. code = llvm::getToken(code).second.ltrim(); OptionsWithRaw args(code); code = args.GetRawPart(); // The position where the expression starts in the command line. assert(original_code_size >= code.size()); std::size_t raw_start = original_code_size - code.size(); // Check if the cursor is actually in the expression string, and if not, we // exit. // FIXME: We should complete the options here. if (cursor_pos < raw_start) return; // Make the cursor_pos again relative to the start of the code string. assert(cursor_pos >= raw_start); cursor_pos -= raw_start; auto language = exe_ctx.GetFrameRef().GetLanguage(); Status error; lldb::UserExpressionSP expr(target.GetUserExpressionForLanguage( code, llvm::StringRef(), language, UserExpression::eResultTypeAny, options, nullptr, error)); if (error.Fail()) return; expr->Complete(exe_ctx, request, cursor_pos); } static lldb_private::Status CanBeUsedForElementCountPrinting(ValueObject &valobj) { CompilerType type(valobj.GetCompilerType()); CompilerType pointee; if (!type.IsPointerType(&pointee)) return Status("as it does not refer to a pointer"); if (pointee.IsVoidType()) return Status("as it refers to a pointer to void"); return Status(); } bool CommandObjectExpression::EvaluateExpression(llvm::StringRef expr, Stream &output_stream, Stream &error_stream, CommandReturnObject &result) { // Don't use m_exe_ctx as this might be called asynchronously after the // command object DoExecute has finished when doing multi-line expression // that use an input reader... ExecutionContext exe_ctx(m_interpreter.GetExecutionContext()); Target *exe_target = exe_ctx.GetTargetPtr(); Target &target = exe_target ? *exe_target : GetDummyTarget(); lldb::ValueObjectSP result_valobj_sp; StackFrame *frame = exe_ctx.GetFramePtr(); if (m_command_options.top_level && !m_command_options.allow_jit) { result.AppendErrorWithFormat( "Can't disable JIT compilation for top-level expressions.\n"); return false; } EvaluateExpressionOptions eval_options = m_command_options.GetEvaluateExpressionOptions(target, m_varobj_options); // This command manually removes the result variable, make sure expression // evaluation doesn't do it first. eval_options.SetSuppressPersistentResult(false); ExpressionResults success = target.EvaluateExpression( expr, frame, result_valobj_sp, eval_options, &m_fixed_expression); // Only mention Fix-Its if the expression evaluator applied them. // Compiler errors refer to the final expression after applying Fix-It(s). if (!m_fixed_expression.empty() && target.GetEnableNotifyAboutFixIts()) { error_stream << " Evaluated this expression after applying Fix-It(s):\n"; error_stream << " " << m_fixed_expression << "\n"; } if (result_valobj_sp) { Format format = m_format_options.GetFormat(); if (result_valobj_sp->GetError().Success()) { if (format != eFormatVoid) { if (format != eFormatDefault) result_valobj_sp->SetFormat(format); if (m_varobj_options.elem_count > 0) { Status error(CanBeUsedForElementCountPrinting(*result_valobj_sp)); if (error.Fail()) { result.AppendErrorWithFormat( "expression cannot be used with --element-count %s\n", error.AsCString("")); return false; } } bool suppress_result = m_command_options.ShouldSuppressResult(m_varobj_options); DumpValueObjectOptions options(m_varobj_options.GetAsDumpOptions( m_command_options.m_verbosity, format)); options.SetHideRootName(suppress_result); options.SetVariableFormatDisplayLanguage( result_valobj_sp->GetPreferredDisplayLanguage()); if (llvm::Error error = result_valobj_sp->Dump(output_stream, options)) { result.AppendError(toString(std::move(error))); return false; } if (suppress_result) if (auto result_var_sp = target.GetPersistentVariable(result_valobj_sp->GetName())) { auto language = result_valobj_sp->GetPreferredDisplayLanguage(); if (auto *persistent_state = target.GetPersistentExpressionStateForLanguage(language)) persistent_state->RemovePersistentVariable(result_var_sp); } result.SetStatus(eReturnStatusSuccessFinishResult); } } else { if (result_valobj_sp->GetError().GetError() == UserExpression::kNoResult) { if (format != eFormatVoid && GetDebugger().GetNotifyVoid()) { error_stream.PutCString("(void)\n"); } result.SetStatus(eReturnStatusSuccessFinishResult); } else { const char *error_cstr = result_valobj_sp->GetError().AsCString(); if (error_cstr && error_cstr[0]) { const size_t error_cstr_len = strlen(error_cstr); const bool ends_with_newline = error_cstr[error_cstr_len - 1] == '\n'; if (strstr(error_cstr, "error:") != error_cstr) error_stream.PutCString("error: "); error_stream.Write(error_cstr, error_cstr_len); if (!ends_with_newline) error_stream.EOL(); } else { error_stream.PutCString("error: unknown error\n"); } result.SetStatus(eReturnStatusFailed); } } } else { error_stream.Printf("error: unknown error\n"); } return (success != eExpressionSetupError && success != eExpressionParseError); } void CommandObjectExpression::IOHandlerInputComplete(IOHandler &io_handler, std::string &line) { io_handler.SetIsDone(true); StreamFileSP output_sp = io_handler.GetOutputStreamFileSP(); StreamFileSP error_sp = io_handler.GetErrorStreamFileSP(); CommandReturnObject return_obj( GetCommandInterpreter().GetDebugger().GetUseColor()); EvaluateExpression(line.c_str(), *output_sp, *error_sp, return_obj); if (output_sp) output_sp->Flush(); if (error_sp) error_sp->Flush(); } bool CommandObjectExpression::IOHandlerIsInputComplete(IOHandler &io_handler, StringList &lines) { // An empty lines is used to indicate the end of input const size_t num_lines = lines.GetSize(); if (num_lines > 0 && lines[num_lines - 1].empty()) { // Remove the last empty line from "lines" so it doesn't appear in our // resulting input and return true to indicate we are done getting lines lines.PopBack(); return true; } return false; } void CommandObjectExpression::GetMultilineExpression() { m_expr_lines.clear(); m_expr_line_count = 0; Debugger &debugger = GetCommandInterpreter().GetDebugger(); bool color_prompt = debugger.GetUseColor(); const bool multiple_lines = true; // Get multiple lines IOHandlerSP io_handler_sp( new IOHandlerEditline(debugger, IOHandler::Type::Expression, "lldb-expr", // Name of input reader for history llvm::StringRef(), // No prompt llvm::StringRef(), // Continuation prompt multiple_lines, color_prompt, 1, // Show line numbers starting at 1 *this)); StreamFileSP output_sp = io_handler_sp->GetOutputStreamFileSP(); if (output_sp) { output_sp->PutCString( "Enter expressions, then terminate with an empty line to evaluate:\n"); output_sp->Flush(); } debugger.RunIOHandlerAsync(io_handler_sp); } static EvaluateExpressionOptions GetExprOptions(ExecutionContext &ctx, CommandObjectExpression::CommandOptions command_options) { command_options.OptionParsingStarting(&ctx); // Default certain settings for REPL regardless of the global settings. command_options.unwind_on_error = false; command_options.ignore_breakpoints = false; command_options.debug = false; EvaluateExpressionOptions expr_options; expr_options.SetUnwindOnError(command_options.unwind_on_error); expr_options.SetIgnoreBreakpoints(command_options.ignore_breakpoints); expr_options.SetTryAllThreads(command_options.try_all_threads); if (command_options.timeout > 0) expr_options.SetTimeout(std::chrono::microseconds(command_options.timeout)); else expr_options.SetTimeout(std::nullopt); return expr_options; } void CommandObjectExpression::DoExecute(llvm::StringRef command, CommandReturnObject &result) { m_fixed_expression.clear(); auto exe_ctx = GetCommandInterpreter().GetExecutionContext(); m_option_group.NotifyOptionParsingStarting(&exe_ctx); if (command.empty()) { GetMultilineExpression(); return; } OptionsWithRaw args(command); llvm::StringRef expr = args.GetRawPart(); if (args.HasArgs()) { if (!ParseOptionsAndNotify(args.GetArgs(), result, m_option_group, exe_ctx)) return; if (m_repl_option.GetOptionValue().GetCurrentValue()) { Target &target = GetSelectedOrDummyTarget(); // Drop into REPL m_expr_lines.clear(); m_expr_line_count = 0; Debugger &debugger = target.GetDebugger(); // Check if the LLDB command interpreter is sitting on top of a REPL // that launched it... if (debugger.CheckTopIOHandlerTypes(IOHandler::Type::CommandInterpreter, IOHandler::Type::REPL)) { // the LLDB command interpreter is sitting on top of a REPL that // launched it, so just say the command interpreter is done and // fall back to the existing REPL m_interpreter.GetIOHandler(false)->SetIsDone(true); } else { // We are launching the REPL on top of the current LLDB command // interpreter, so just push one bool initialize = false; Status repl_error; REPLSP repl_sp(target.GetREPL(repl_error, m_command_options.language, nullptr, false)); if (!repl_sp) { initialize = true; repl_sp = target.GetREPL(repl_error, m_command_options.language, nullptr, true); if (!repl_error.Success()) { result.SetError(repl_error); return; } } if (repl_sp) { if (initialize) { repl_sp->SetEvaluateOptions( GetExprOptions(exe_ctx, m_command_options)); repl_sp->SetFormatOptions(m_format_options); repl_sp->SetValueObjectDisplayOptions(m_varobj_options); } IOHandlerSP io_handler_sp(repl_sp->GetIOHandler()); io_handler_sp->SetIsDone(false); debugger.RunIOHandlerAsync(io_handler_sp); } else { repl_error.SetErrorStringWithFormat( "Couldn't create a REPL for %s", Language::GetNameForLanguageType(m_command_options.language)); result.SetError(repl_error); return; } } } // No expression following options else if (expr.empty()) { GetMultilineExpression(); return; } } Target &target = GetSelectedOrDummyTarget(); if (EvaluateExpression(expr, result.GetOutputStream(), result.GetErrorStream(), result)) { if (!m_fixed_expression.empty() && target.GetEnableNotifyAboutFixIts()) { CommandHistory &history = m_interpreter.GetCommandHistory(); // FIXME: Can we figure out what the user actually typed (e.g. some alias // for expr???) // If we can it would be nice to show that. std::string fixed_command("expression "); if (args.HasArgs()) { // Add in any options that might have been in the original command: fixed_command.append(std::string(args.GetArgStringWithDelimiter())); fixed_command.append(m_fixed_expression); } else fixed_command.append(m_fixed_expression); history.AppendString(fixed_command); } return; } result.SetStatus(eReturnStatusFailed); }