1 //===-- CommandObjectExpression.cpp -----------------------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 #include "llvm/ADT/STLExtras.h"
11 #include "llvm/ADT/StringRef.h"
13 #include "CommandObjectExpression.h"
14 #include "Plugins/ExpressionParser/Clang/ClangExpressionVariable.h"
15 #include "lldb/Core/Debugger.h"
16 #include "lldb/Core/Value.h"
17 #include "lldb/Core/ValueObjectVariable.h"
18 #include "lldb/DataFormatters/ValueObjectPrinter.h"
19 #include "lldb/Expression/DWARFExpression.h"
20 #include "lldb/Expression/REPL.h"
21 #include "lldb/Expression/UserExpression.h"
22 #include "lldb/Host/Host.h"
23 #include "lldb/Host/OptionParser.h"
24 #include "lldb/Interpreter/CommandInterpreter.h"
25 #include "lldb/Interpreter/CommandReturnObject.h"
26 #include "lldb/Interpreter/OptionArgParser.h"
27 #include "lldb/Symbol/ObjectFile.h"
28 #include "lldb/Symbol/Variable.h"
29 #include "lldb/Target/Language.h"
30 #include "lldb/Target/Process.h"
31 #include "lldb/Target/StackFrame.h"
32 #include "lldb/Target/Target.h"
33 #include "lldb/Target/Thread.h"
36 using namespace lldb_private;
38 CommandObjectExpression::CommandOptions::CommandOptions() : OptionGroup() {}
40 CommandObjectExpression::CommandOptions::~CommandOptions() = default;
42 static constexpr OptionEnumValueElement g_description_verbosity_type[] = {
43 {eLanguageRuntimeDescriptionDisplayVerbosityCompact, "compact",
44 "Only show the description string"},
45 {eLanguageRuntimeDescriptionDisplayVerbosityFull, "full",
46 "Show the full output, including persistent variable's name and type"} };
48 static constexpr OptionEnumValues DescriptionVerbosityTypes() {
49 return OptionEnumValues(g_description_verbosity_type);
52 static constexpr OptionDefinition g_expression_options[] = {
54 {LLDB_OPT_SET_1 | LLDB_OPT_SET_2, false, "all-threads", 'a', OptionParser::eRequiredArgument, nullptr, {}, 0, eArgTypeBoolean, "Should we run all threads if the execution doesn't complete on one thread."},
55 {LLDB_OPT_SET_1 | LLDB_OPT_SET_2, false, "ignore-breakpoints", 'i', OptionParser::eRequiredArgument, nullptr, {}, 0, eArgTypeBoolean, "Ignore breakpoint hits while running expressions"},
56 {LLDB_OPT_SET_1 | LLDB_OPT_SET_2, false, "timeout", 't', OptionParser::eRequiredArgument, nullptr, {}, 0, eArgTypeUnsignedInteger, "Timeout value (in microseconds) for running the expression."},
57 {LLDB_OPT_SET_1 | LLDB_OPT_SET_2, false, "unwind-on-error", 'u', OptionParser::eRequiredArgument, nullptr, {}, 0, eArgTypeBoolean, "Clean up program state if the expression causes a crash, or raises a signal. "
58 "Note, unlike gdb hitting a breakpoint is controlled by another option (-i)."},
59 {LLDB_OPT_SET_1 | LLDB_OPT_SET_2, false, "debug", 'g', OptionParser::eNoArgument, nullptr, {}, 0, eArgTypeNone, "When specified, debug the JIT code by setting a breakpoint on the first instruction "
60 "and forcing breakpoints to not be ignored (-i0) and no unwinding to happen on error (-u0)."},
61 {LLDB_OPT_SET_1 | LLDB_OPT_SET_2, false, "language", 'l', OptionParser::eRequiredArgument, nullptr, {}, 0, eArgTypeLanguage, "Specifies the Language to use when parsing the expression. If not set the target.language "
63 {LLDB_OPT_SET_1 | LLDB_OPT_SET_2, false, "apply-fixits", 'X', OptionParser::eRequiredArgument, nullptr, {}, 0, eArgTypeLanguage, "If true, simple fix-it hints will be automatically applied to the expression." },
64 {LLDB_OPT_SET_1, false, "description-verbosity", 'v', OptionParser::eOptionalArgument, nullptr, DescriptionVerbosityTypes(), 0, eArgTypeDescriptionVerbosity, "How verbose should the output of this expression be, if the object description is asked for."},
65 {LLDB_OPT_SET_1 | LLDB_OPT_SET_2, false, "top-level", 'p', OptionParser::eNoArgument, nullptr, {}, 0, eArgTypeNone, "Interpret the expression as a complete translation unit, without injecting it into the local "
66 "context. Allows declaration of persistent, top-level entities without a $ prefix."},
67 {LLDB_OPT_SET_1 | LLDB_OPT_SET_2, false, "allow-jit", 'j', OptionParser::eRequiredArgument, nullptr, {}, 0, eArgTypeBoolean, "Controls whether the expression can fall back to being JITted if it's not supported by "
68 "the interpreter (defaults to true)."}
72 Status CommandObjectExpression::CommandOptions::SetOptionValue(
73 uint32_t option_idx, llvm::StringRef option_arg,
74 ExecutionContext *execution_context) {
77 const int short_option = GetDefinitions()[option_idx].short_option;
79 switch (short_option) {
81 language = Language::GetLanguageTypeFromString(option_arg);
82 if (language == eLanguageTypeUnknown)
83 error.SetErrorStringWithFormat(
84 "unknown language type: '%s' for expression",
85 option_arg.str().c_str());
91 result = OptionArgParser::ToBoolean(option_arg, true, &success);
93 error.SetErrorStringWithFormat(
94 "invalid all-threads value setting: \"%s\"",
95 option_arg.str().c_str());
97 try_all_threads = result;
102 bool tmp_value = OptionArgParser::ToBoolean(option_arg, true, &success);
104 ignore_breakpoints = tmp_value;
106 error.SetErrorStringWithFormat(
107 "could not convert \"%s\" to a boolean value.",
108 option_arg.str().c_str());
114 bool tmp_value = OptionArgParser::ToBoolean(option_arg, true, &success);
116 allow_jit = tmp_value;
118 error.SetErrorStringWithFormat(
119 "could not convert \"%s\" to a boolean value.",
120 option_arg.str().c_str());
125 if (option_arg.getAsInteger(0, timeout)) {
127 error.SetErrorStringWithFormat("invalid timeout setting \"%s\"",
128 option_arg.str().c_str());
134 bool tmp_value = OptionArgParser::ToBoolean(option_arg, true, &success);
136 unwind_on_error = tmp_value;
138 error.SetErrorStringWithFormat(
139 "could not convert \"%s\" to a boolean value.",
140 option_arg.str().c_str());
145 if (option_arg.empty()) {
146 m_verbosity = eLanguageRuntimeDescriptionDisplayVerbosityFull;
149 m_verbosity = (LanguageRuntimeDescriptionDisplayVerbosity)
150 OptionArgParser::ToOptionEnum(
151 option_arg, GetDefinitions()[option_idx].enum_values, 0, error);
152 if (!error.Success())
153 error.SetErrorStringWithFormat(
154 "unrecognized value for description-verbosity '%s'",
155 option_arg.str().c_str());
160 unwind_on_error = false;
161 ignore_breakpoints = false;
170 bool tmp_value = OptionArgParser::ToBoolean(option_arg, true, &success);
172 auto_apply_fixits = tmp_value ? eLazyBoolYes : eLazyBoolNo;
174 error.SetErrorStringWithFormat(
175 "could not convert \"%s\" to a boolean value.",
176 option_arg.str().c_str());
181 error.SetErrorStringWithFormat("invalid short option character '%c'",
189 void CommandObjectExpression::CommandOptions::OptionParsingStarting(
190 ExecutionContext *execution_context) {
192 execution_context ? execution_context->GetProcessSP() : ProcessSP();
194 ignore_breakpoints = process_sp->GetIgnoreBreakpointsInExpressions();
195 unwind_on_error = process_sp->GetUnwindOnErrorInExpressions();
197 ignore_breakpoints = true;
198 unwind_on_error = true;
202 try_all_threads = true;
205 language = eLanguageTypeUnknown;
206 m_verbosity = eLanguageRuntimeDescriptionDisplayVerbosityCompact;
207 auto_apply_fixits = eLazyBoolCalculate;
212 llvm::ArrayRef<OptionDefinition>
213 CommandObjectExpression::CommandOptions::GetDefinitions() {
214 return llvm::makeArrayRef(g_expression_options);
217 CommandObjectExpression::CommandObjectExpression(
218 CommandInterpreter &interpreter)
220 interpreter, "expression", "Evaluate an expression on the current "
221 "thread. Displays any returned value "
222 "with LLDB's default formatting.",
223 "", eCommandProcessMustBePaused | eCommandTryTargetAPILock),
224 IOHandlerDelegate(IOHandlerDelegate::Completion::Expression),
225 m_option_group(), m_format_options(eFormatDefault),
226 m_repl_option(LLDB_OPT_SET_1, false, "repl", 'r', "Drop into REPL", false,
228 m_command_options(), m_expr_line_count(0), m_expr_lines() {
231 Single and multi-line expressions:
234 " The expression provided on the command line must be a complete expression \
235 with no newlines. To evaluate a multi-line expression, \
236 hit a return after an empty expression, and lldb will enter the multi-line expression editor. \
237 Hit return on an empty line to end the multi-line expression."
244 " If the expression can be evaluated statically (without running code) then it will be. \
245 Otherwise, by default the expression will run on the current thread with a short timeout: \
246 currently .25 seconds. If it doesn't return in that time, the evaluation will be interrupted \
247 and resumed with all threads running. You can use the -a option to disable retrying on all \
248 threads. You can use the -t option to set a shorter timeout."
251 User defined variables:
254 " You can define your own variables for convenience or to be used in subsequent expressions. \
255 You define them the same way you would define variables in C. If the first character of \
256 your user defined variable is a $, then the variable's value will be available in future \
257 expressions, otherwise it will just be available in the current expression."
260 Continuing evaluation after a breakpoint:
263 " If the \"-i false\" option is used, and execution is interrupted by a breakpoint hit, once \
264 you are done with your investigation, you can either remove the expression execution frames \
265 from the stack with \"thread return -x\" or if you are still interested in the expression result \
266 you can issue the \"continue\" command and the expression evaluation will complete and the \
267 expression result will be available using the \"thread.completed-expression\" key in the thread \
274 expr my_struct->a = my_array[3]
275 expr -f bin -- (index * 8) + 5
276 expr unsigned int $foo = 5
277 expr char c[] = \"foo\"; c[0])");
279 CommandArgumentEntry arg;
280 CommandArgumentData expression_arg;
282 // Define the first (and only) variant of this arg.
283 expression_arg.arg_type = eArgTypeExpression;
284 expression_arg.arg_repetition = eArgRepeatPlain;
286 // There is only one variant this argument could be; put it into the argument
288 arg.push_back(expression_arg);
290 // Push the data for the first argument into the m_arguments vector.
291 m_arguments.push_back(arg);
293 // Add the "--format" and "--gdb-format"
294 m_option_group.Append(&m_format_options,
295 OptionGroupFormat::OPTION_GROUP_FORMAT |
296 OptionGroupFormat::OPTION_GROUP_GDB_FMT,
298 m_option_group.Append(&m_command_options);
299 m_option_group.Append(&m_varobj_options, LLDB_OPT_SET_ALL,
300 LLDB_OPT_SET_1 | LLDB_OPT_SET_2);
301 m_option_group.Append(&m_repl_option, LLDB_OPT_SET_ALL, LLDB_OPT_SET_3);
302 m_option_group.Finalize();
305 CommandObjectExpression::~CommandObjectExpression() = default;
307 Options *CommandObjectExpression::GetOptions() { return &m_option_group; }
309 int CommandObjectExpression::HandleCompletion(CompletionRequest &request) {
310 EvaluateExpressionOptions options;
311 options.SetCoerceToId(m_varobj_options.use_objc);
312 options.SetLanguage(m_command_options.language);
313 options.SetExecutionPolicy(lldb_private::eExecutionPolicyNever);
314 options.SetAutoApplyFixIts(false);
315 options.SetGenerateDebugInfo(false);
317 // We need a valid execution context with a frame pointer for this
318 // completion, so if we don't have one we should try to make a valid
319 // execution context.
320 if (m_interpreter.GetExecutionContext().GetFramePtr() == nullptr)
321 m_interpreter.UpdateExecutionContext(nullptr);
323 // This didn't work, so let's get out before we start doing things that
324 // expect a valid frame pointer.
325 if (m_interpreter.GetExecutionContext().GetFramePtr() == nullptr)
328 ExecutionContext exe_ctx(m_interpreter.GetExecutionContext());
330 Target *target = exe_ctx.GetTargetPtr();
333 target = GetDummyTarget();
338 unsigned cursor_pos = request.GetRawCursorPos();
339 llvm::StringRef code = request.GetRawLine();
341 const std::size_t original_code_size = code.size();
343 // Remove the first token which is 'expr' or some alias/abbreviation of that.
344 code = llvm::getToken(code).second.ltrim();
345 OptionsWithRaw args(code);
346 code = args.GetRawPart();
348 // The position where the expression starts in the command line.
349 assert(original_code_size >= code.size());
350 std::size_t raw_start = original_code_size - code.size();
352 // Check if the cursor is actually in the expression string, and if not, we
354 // FIXME: We should complete the options here.
355 if (cursor_pos < raw_start)
358 // Make the cursor_pos again relative to the start of the code string.
359 assert(cursor_pos >= raw_start);
360 cursor_pos -= raw_start;
362 auto language = exe_ctx.GetFrameRef().GetLanguage();
365 lldb::UserExpressionSP expr(target->GetUserExpressionForLanguage(
366 code, llvm::StringRef(), language, UserExpression::eResultTypeAny,
371 expr->Complete(exe_ctx, request, cursor_pos);
372 return request.GetNumberOfMatches();
375 static lldb_private::Status
376 CanBeUsedForElementCountPrinting(ValueObject &valobj) {
377 CompilerType type(valobj.GetCompilerType());
378 CompilerType pointee;
379 if (!type.IsPointerType(&pointee))
380 return Status("as it does not refer to a pointer");
381 if (pointee.IsVoidType())
382 return Status("as it refers to a pointer to void");
386 bool CommandObjectExpression::EvaluateExpression(llvm::StringRef expr,
387 Stream *output_stream,
388 Stream *error_stream,
389 CommandReturnObject *result) {
390 // Don't use m_exe_ctx as this might be called asynchronously after the
391 // command object DoExecute has finished when doing multi-line expression
392 // that use an input reader...
393 ExecutionContext exe_ctx(m_interpreter.GetExecutionContext());
395 Target *target = exe_ctx.GetTargetPtr();
398 target = GetDummyTarget();
401 lldb::ValueObjectSP result_valobj_sp;
402 bool keep_in_memory = true;
403 StackFrame *frame = exe_ctx.GetFramePtr();
405 EvaluateExpressionOptions options;
406 options.SetCoerceToId(m_varobj_options.use_objc);
407 options.SetUnwindOnError(m_command_options.unwind_on_error);
408 options.SetIgnoreBreakpoints(m_command_options.ignore_breakpoints);
409 options.SetKeepInMemory(keep_in_memory);
410 options.SetUseDynamic(m_varobj_options.use_dynamic);
411 options.SetTryAllThreads(m_command_options.try_all_threads);
412 options.SetDebug(m_command_options.debug);
413 options.SetLanguage(m_command_options.language);
414 options.SetExecutionPolicy(
415 m_command_options.allow_jit
416 ? EvaluateExpressionOptions::default_execution_policy
417 : lldb_private::eExecutionPolicyNever);
419 bool auto_apply_fixits;
420 if (m_command_options.auto_apply_fixits == eLazyBoolCalculate)
421 auto_apply_fixits = target->GetEnableAutoApplyFixIts();
423 auto_apply_fixits = m_command_options.auto_apply_fixits == eLazyBoolYes;
425 options.SetAutoApplyFixIts(auto_apply_fixits);
427 if (m_command_options.top_level)
428 options.SetExecutionPolicy(eExecutionPolicyTopLevel);
430 // If there is any chance we are going to stop and want to see what went
431 // wrong with our expression, we should generate debug info
432 if (!m_command_options.ignore_breakpoints ||
433 !m_command_options.unwind_on_error)
434 options.SetGenerateDebugInfo(true);
436 if (m_command_options.timeout > 0)
437 options.SetTimeout(std::chrono::microseconds(m_command_options.timeout));
439 options.SetTimeout(llvm::None);
441 ExpressionResults success = target->EvaluateExpression(
442 expr, frame, result_valobj_sp, options, &m_fixed_expression);
444 // We only tell you about the FixIt if we applied it. The compiler errors
445 // will suggest the FixIt if it parsed.
446 if (error_stream && !m_fixed_expression.empty() &&
447 target->GetEnableNotifyAboutFixIts()) {
448 if (success == eExpressionCompleted)
449 error_stream->Printf(
450 " Fix-it applied, fixed expression was: \n %s\n",
451 m_fixed_expression.c_str());
454 if (result_valobj_sp) {
455 Format format = m_format_options.GetFormat();
457 if (result_valobj_sp->GetError().Success()) {
458 if (format != eFormatVoid) {
459 if (format != eFormatDefault)
460 result_valobj_sp->SetFormat(format);
462 if (m_varobj_options.elem_count > 0) {
463 Status error(CanBeUsedForElementCountPrinting(*result_valobj_sp));
465 result->AppendErrorWithFormat(
466 "expression cannot be used with --element-count %s\n",
467 error.AsCString(""));
468 result->SetStatus(eReturnStatusFailed);
473 DumpValueObjectOptions options(m_varobj_options.GetAsDumpOptions(
474 m_command_options.m_verbosity, format));
475 options.SetVariableFormatDisplayLanguage(
476 result_valobj_sp->GetPreferredDisplayLanguage());
478 result_valobj_sp->Dump(*output_stream, options);
481 result->SetStatus(eReturnStatusSuccessFinishResult);
484 if (result_valobj_sp->GetError().GetError() ==
485 UserExpression::kNoResult) {
486 if (format != eFormatVoid &&
487 m_interpreter.GetDebugger().GetNotifyVoid()) {
488 error_stream->PutCString("(void)\n");
492 result->SetStatus(eReturnStatusSuccessFinishResult);
494 const char *error_cstr = result_valobj_sp->GetError().AsCString();
495 if (error_cstr && error_cstr[0]) {
496 const size_t error_cstr_len = strlen(error_cstr);
497 const bool ends_with_newline =
498 error_cstr[error_cstr_len - 1] == '\n';
499 if (strstr(error_cstr, "error:") != error_cstr)
500 error_stream->PutCString("error: ");
501 error_stream->Write(error_cstr, error_cstr_len);
502 if (!ends_with_newline)
505 error_stream->PutCString("error: unknown error\n");
509 result->SetStatus(eReturnStatusFailed);
514 error_stream->Printf("error: invalid execution context for expression\n");
521 void CommandObjectExpression::IOHandlerInputComplete(IOHandler &io_handler,
523 io_handler.SetIsDone(true);
524 // StreamSP output_stream =
525 // io_handler.GetDebugger().GetAsyncOutputStream();
526 // StreamSP error_stream = io_handler.GetDebugger().GetAsyncErrorStream();
527 StreamFileSP output_sp(io_handler.GetOutputStreamFile());
528 StreamFileSP error_sp(io_handler.GetErrorStreamFile());
530 EvaluateExpression(line.c_str(), output_sp.get(), error_sp.get());
537 bool CommandObjectExpression::IOHandlerIsInputComplete(IOHandler &io_handler,
539 // An empty lines is used to indicate the end of input
540 const size_t num_lines = lines.GetSize();
541 if (num_lines > 0 && lines[num_lines - 1].empty()) {
542 // Remove the last empty line from "lines" so it doesn't appear in our
543 // resulting input and return true to indicate we are done getting lines
550 void CommandObjectExpression::GetMultilineExpression() {
551 m_expr_lines.clear();
552 m_expr_line_count = 0;
554 Debugger &debugger = GetCommandInterpreter().GetDebugger();
555 bool color_prompt = debugger.GetUseColor();
556 const bool multiple_lines = true; // Get multiple lines
557 IOHandlerSP io_handler_sp(
558 new IOHandlerEditline(debugger, IOHandler::Type::Expression,
559 "lldb-expr", // Name of input reader for history
560 llvm::StringRef(), // No prompt
561 llvm::StringRef(), // Continuation prompt
562 multiple_lines, color_prompt,
563 1, // Show line numbers starting at 1
566 StreamFileSP output_sp(io_handler_sp->GetOutputStreamFile());
568 output_sp->PutCString(
569 "Enter expressions, then terminate with an empty line to evaluate:\n");
572 debugger.PushIOHandler(io_handler_sp);
575 bool CommandObjectExpression::DoExecute(llvm::StringRef command,
576 CommandReturnObject &result) {
577 m_fixed_expression.clear();
578 auto exe_ctx = GetCommandInterpreter().GetExecutionContext();
579 m_option_group.NotifyOptionParsingStarting(&exe_ctx);
581 if (command.empty()) {
582 GetMultilineExpression();
583 return result.Succeeded();
586 OptionsWithRaw args(command);
587 llvm::StringRef expr = args.GetRawPart();
589 if (args.HasArgs()) {
590 if (!ParseOptionsAndNotify(args.GetArgs(), result, m_option_group, exe_ctx))
593 if (m_repl_option.GetOptionValue().GetCurrentValue()) {
594 Target *target = m_interpreter.GetExecutionContext().GetTargetPtr();
597 m_expr_lines.clear();
598 m_expr_line_count = 0;
600 Debugger &debugger = target->GetDebugger();
602 // Check if the LLDB command interpreter is sitting on top of a REPL
603 // that launched it...
604 if (debugger.CheckTopIOHandlerTypes(IOHandler::Type::CommandInterpreter,
605 IOHandler::Type::REPL)) {
606 // the LLDB command interpreter is sitting on top of a REPL that
607 // launched it, so just say the command interpreter is done and
608 // fall back to the existing REPL
609 m_interpreter.GetIOHandler(false)->SetIsDone(true);
611 // We are launching the REPL on top of the current LLDB command
612 // interpreter, so just push one
613 bool initialize = false;
615 REPLSP repl_sp(target->GetREPL(repl_error, m_command_options.language,
620 repl_sp = target->GetREPL(repl_error, m_command_options.language,
622 if (!repl_error.Success()) {
623 result.SetError(repl_error);
624 return result.Succeeded();
630 repl_sp->SetCommandOptions(m_command_options);
631 repl_sp->SetFormatOptions(m_format_options);
632 repl_sp->SetValueObjectDisplayOptions(m_varobj_options);
635 IOHandlerSP io_handler_sp(repl_sp->GetIOHandler());
637 io_handler_sp->SetIsDone(false);
639 debugger.PushIOHandler(io_handler_sp);
641 repl_error.SetErrorStringWithFormat(
642 "Couldn't create a REPL for %s",
643 Language::GetNameForLanguageType(m_command_options.language));
644 result.SetError(repl_error);
645 return result.Succeeded();
650 // No expression following options
651 else if (expr.empty()) {
652 GetMultilineExpression();
653 return result.Succeeded();
657 Target *target = GetSelectedOrDummyTarget();
658 if (EvaluateExpression(expr, &(result.GetOutputStream()),
659 &(result.GetErrorStream()), &result)) {
661 if (!m_fixed_expression.empty() && target->GetEnableNotifyAboutFixIts()) {
662 CommandHistory &history = m_interpreter.GetCommandHistory();
663 // FIXME: Can we figure out what the user actually typed (e.g. some alias
665 // If we can it would be nice to show that.
666 std::string fixed_command("expression ");
667 if (args.HasArgs()) {
668 // Add in any options that might have been in the original command:
669 fixed_command.append(args.GetArgStringWithDelimiter());
670 fixed_command.append(m_fixed_expression);
672 fixed_command.append(m_fixed_expression);
673 history.AppendString(fixed_command);
675 // Increment statistics to record this expression evaluation success.
676 target->IncrementStats(StatisticKind::ExpressionSuccessful);
680 // Increment statistics to record this expression evaluation failure.
681 target->IncrementStats(StatisticKind::ExpressionFailure);
682 result.SetStatus(eReturnStatusFailed);