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 //===----------------------------------------------------------------------===//
12 // Other libraries and framework includes
13 #include "llvm/ADT/STLExtras.h"
14 #include "llvm/ADT/StringRef.h"
17 #include "CommandObjectExpression.h"
18 #include "Plugins/ExpressionParser/Clang/ClangExpressionVariable.h"
19 #include "lldb/Core/Debugger.h"
20 #include "lldb/Core/Value.h"
21 #include "lldb/Core/ValueObjectVariable.h"
22 #include "lldb/DataFormatters/ValueObjectPrinter.h"
23 #include "lldb/Expression/DWARFExpression.h"
24 #include "lldb/Expression/REPL.h"
25 #include "lldb/Expression/UserExpression.h"
26 #include "lldb/Host/Host.h"
27 #include "lldb/Host/OptionParser.h"
28 #include "lldb/Interpreter/CommandInterpreter.h"
29 #include "lldb/Interpreter/CommandReturnObject.h"
30 #include "lldb/Symbol/ObjectFile.h"
31 #include "lldb/Symbol/Variable.h"
32 #include "lldb/Target/Language.h"
33 #include "lldb/Target/Process.h"
34 #include "lldb/Target/StackFrame.h"
35 #include "lldb/Target/Target.h"
36 #include "lldb/Target/Thread.h"
39 using namespace lldb_private;
41 CommandObjectExpression::CommandOptions::CommandOptions() : OptionGroup() {}
43 CommandObjectExpression::CommandOptions::~CommandOptions() = default;
45 static OptionEnumValueElement g_description_verbosity_type[] = {
46 {eLanguageRuntimeDescriptionDisplayVerbosityCompact, "compact",
47 "Only show the description string"},
48 {eLanguageRuntimeDescriptionDisplayVerbosityFull, "full",
49 "Show the full output, including persistent variable's name and type"},
50 {0, nullptr, nullptr}};
52 static OptionDefinition g_expression_options[] = {
54 {LLDB_OPT_SET_1 | LLDB_OPT_SET_2, false, "all-threads", 'a', OptionParser::eRequiredArgument, nullptr, 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, nullptr, 0, eArgTypeBoolean, "Ignore breakpoint hits while running expressions"},
56 {LLDB_OPT_SET_1 | LLDB_OPT_SET_2, false, "timeout", 't', OptionParser::eRequiredArgument, nullptr, 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, 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, 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, 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, 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, g_description_verbosity_type, 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, 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, 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 = Args::StringToBoolean(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 = Args::StringToBoolean(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 = Args::StringToBoolean(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 = Args::StringToBoolean(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;
150 (LanguageRuntimeDescriptionDisplayVerbosity)Args::StringToOptionEnum(
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 = Args::StringToBoolean(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() {
234 " If the expression can be evaluated statically (without running code) then it will be. \
235 Otherwise, by default the expression will run on the current thread with a short timeout: \
236 currently .25 seconds. If it doesn't return in that time, the evaluation will be interrupted \
237 and resumed with all threads running. You can use the -a option to disable retrying on all \
238 threads. You can use the -t option to set a shorter timeout."
241 User defined variables:
244 " You can define your own variables for convenience or to be used in subsequent expressions. \
245 You define them the same way you would define variables in C. If the first character of \
246 your user defined variable is a $, then the variable's value will be available in future \
247 expressions, otherwise it will just be available in the current expression."
250 Continuing evaluation after a breakpoint:
253 " If the \"-i false\" option is used, and execution is interrupted by a breakpoint hit, once \
254 you are done with your investigation, you can either remove the expression execution frames \
255 from the stack with \"thread return -x\" or if you are still interested in the expression result \
256 you can issue the \"continue\" command and the expression evaluation will complete and the \
257 expression result will be available using the \"thread.completed-expression\" key in the thread \
263 expr my_struct->a = my_array[3]
264 expr -f bin -- (index * 8) + 5
265 expr unsigned int $foo = 5
266 expr char c[] = \"foo\"; c[0])");
268 CommandArgumentEntry arg;
269 CommandArgumentData expression_arg;
271 // Define the first (and only) variant of this arg.
272 expression_arg.arg_type = eArgTypeExpression;
273 expression_arg.arg_repetition = eArgRepeatPlain;
275 // There is only one variant this argument could be; put it into the argument
277 arg.push_back(expression_arg);
279 // Push the data for the first argument into the m_arguments vector.
280 m_arguments.push_back(arg);
282 // Add the "--format" and "--gdb-format"
283 m_option_group.Append(&m_format_options,
284 OptionGroupFormat::OPTION_GROUP_FORMAT |
285 OptionGroupFormat::OPTION_GROUP_GDB_FMT,
287 m_option_group.Append(&m_command_options);
288 m_option_group.Append(&m_varobj_options, LLDB_OPT_SET_ALL,
289 LLDB_OPT_SET_1 | LLDB_OPT_SET_2);
290 m_option_group.Append(&m_repl_option, LLDB_OPT_SET_ALL, LLDB_OPT_SET_3);
291 m_option_group.Finalize();
294 CommandObjectExpression::~CommandObjectExpression() = default;
296 Options *CommandObjectExpression::GetOptions() { return &m_option_group; }
298 static lldb_private::Status
299 CanBeUsedForElementCountPrinting(ValueObject &valobj) {
300 CompilerType type(valobj.GetCompilerType());
301 CompilerType pointee;
302 if (!type.IsPointerType(&pointee))
303 return Status("as it does not refer to a pointer");
304 if (pointee.IsVoidType())
305 return Status("as it refers to a pointer to void");
309 bool CommandObjectExpression::EvaluateExpression(const char *expr,
310 Stream *output_stream,
311 Stream *error_stream,
312 CommandReturnObject *result) {
313 // Don't use m_exe_ctx as this might be called asynchronously
314 // after the command object DoExecute has finished when doing
315 // multi-line expression that use an input reader...
316 ExecutionContext exe_ctx(m_interpreter.GetExecutionContext());
318 Target *target = exe_ctx.GetTargetPtr();
321 target = GetDummyTarget();
324 lldb::ValueObjectSP result_valobj_sp;
325 bool keep_in_memory = true;
326 StackFrame *frame = exe_ctx.GetFramePtr();
328 EvaluateExpressionOptions options;
329 options.SetCoerceToId(m_varobj_options.use_objc);
330 options.SetUnwindOnError(m_command_options.unwind_on_error);
331 options.SetIgnoreBreakpoints(m_command_options.ignore_breakpoints);
332 options.SetKeepInMemory(keep_in_memory);
333 options.SetUseDynamic(m_varobj_options.use_dynamic);
334 options.SetTryAllThreads(m_command_options.try_all_threads);
335 options.SetDebug(m_command_options.debug);
336 options.SetLanguage(m_command_options.language);
337 options.SetExecutionPolicy(
338 m_command_options.allow_jit
339 ? EvaluateExpressionOptions::default_execution_policy
340 : lldb_private::eExecutionPolicyNever);
342 bool auto_apply_fixits;
343 if (m_command_options.auto_apply_fixits == eLazyBoolCalculate)
344 auto_apply_fixits = target->GetEnableAutoApplyFixIts();
347 m_command_options.auto_apply_fixits == eLazyBoolYes ? true : false;
349 options.SetAutoApplyFixIts(auto_apply_fixits);
351 if (m_command_options.top_level)
352 options.SetExecutionPolicy(eExecutionPolicyTopLevel);
354 // If there is any chance we are going to stop and want to see
355 // what went wrong with our expression, we should generate debug info
356 if (!m_command_options.ignore_breakpoints ||
357 !m_command_options.unwind_on_error)
358 options.SetGenerateDebugInfo(true);
360 if (m_command_options.timeout > 0)
361 options.SetTimeout(std::chrono::microseconds(m_command_options.timeout));
363 options.SetTimeout(llvm::None);
365 ExpressionResults success = target->EvaluateExpression(
366 expr, frame, result_valobj_sp, options, &m_fixed_expression);
368 // We only tell you about the FixIt if we applied it. The compiler errors
369 // will suggest the FixIt if it parsed.
370 if (error_stream && !m_fixed_expression.empty() &&
371 target->GetEnableNotifyAboutFixIts()) {
372 if (success == eExpressionCompleted)
373 error_stream->Printf(
374 " Fix-it applied, fixed expression was: \n %s\n",
375 m_fixed_expression.c_str());
378 if (result_valobj_sp) {
379 Format format = m_format_options.GetFormat();
381 if (result_valobj_sp->GetError().Success()) {
382 if (format != eFormatVoid) {
383 if (format != eFormatDefault)
384 result_valobj_sp->SetFormat(format);
386 if (m_varobj_options.elem_count > 0) {
387 Status error(CanBeUsedForElementCountPrinting(*result_valobj_sp));
389 result->AppendErrorWithFormat(
390 "expression cannot be used with --element-count %s\n",
391 error.AsCString(""));
392 result->SetStatus(eReturnStatusFailed);
397 DumpValueObjectOptions options(m_varobj_options.GetAsDumpOptions(
398 m_command_options.m_verbosity, format));
399 options.SetVariableFormatDisplayLanguage(
400 result_valobj_sp->GetPreferredDisplayLanguage());
402 result_valobj_sp->Dump(*output_stream, options);
405 result->SetStatus(eReturnStatusSuccessFinishResult);
408 if (result_valobj_sp->GetError().GetError() ==
409 UserExpression::kNoResult) {
410 if (format != eFormatVoid &&
411 m_interpreter.GetDebugger().GetNotifyVoid()) {
412 error_stream->PutCString("(void)\n");
416 result->SetStatus(eReturnStatusSuccessFinishResult);
418 const char *error_cstr = result_valobj_sp->GetError().AsCString();
419 if (error_cstr && error_cstr[0]) {
420 const size_t error_cstr_len = strlen(error_cstr);
421 const bool ends_with_newline =
422 error_cstr[error_cstr_len - 1] == '\n';
423 if (strstr(error_cstr, "error:") != error_cstr)
424 error_stream->PutCString("error: ");
425 error_stream->Write(error_cstr, error_cstr_len);
426 if (!ends_with_newline)
429 error_stream->PutCString("error: unknown error\n");
433 result->SetStatus(eReturnStatusFailed);
438 error_stream->Printf("error: invalid execution context for expression\n");
445 void CommandObjectExpression::IOHandlerInputComplete(IOHandler &io_handler,
447 io_handler.SetIsDone(true);
448 // StreamSP output_stream =
449 // io_handler.GetDebugger().GetAsyncOutputStream();
450 // StreamSP error_stream = io_handler.GetDebugger().GetAsyncErrorStream();
451 StreamFileSP output_sp(io_handler.GetOutputStreamFile());
452 StreamFileSP error_sp(io_handler.GetErrorStreamFile());
454 EvaluateExpression(line.c_str(), output_sp.get(), error_sp.get());
461 bool CommandObjectExpression::IOHandlerIsInputComplete(IOHandler &io_handler,
463 // An empty lines is used to indicate the end of input
464 const size_t num_lines = lines.GetSize();
465 if (num_lines > 0 && lines[num_lines - 1].empty()) {
466 // Remove the last empty line from "lines" so it doesn't appear
467 // in our resulting input and return true to indicate we are done
475 void CommandObjectExpression::GetMultilineExpression() {
476 m_expr_lines.clear();
477 m_expr_line_count = 0;
479 Debugger &debugger = GetCommandInterpreter().GetDebugger();
480 bool color_prompt = debugger.GetUseColor();
481 const bool multiple_lines = true; // Get multiple lines
482 IOHandlerSP io_handler_sp(
483 new IOHandlerEditline(debugger, IOHandler::Type::Expression,
484 "lldb-expr", // Name of input reader for history
485 llvm::StringRef(), // No prompt
486 llvm::StringRef(), // Continuation prompt
487 multiple_lines, color_prompt,
488 1, // Show line numbers starting at 1
491 StreamFileSP output_sp(io_handler_sp->GetOutputStreamFile());
493 output_sp->PutCString(
494 "Enter expressions, then terminate with an empty line to evaluate:\n");
497 debugger.PushIOHandler(io_handler_sp);
500 bool CommandObjectExpression::DoExecute(const char *command,
501 CommandReturnObject &result) {
502 m_fixed_expression.clear();
503 auto exe_ctx = GetCommandInterpreter().GetExecutionContext();
504 m_option_group.NotifyOptionParsingStarting(&exe_ctx);
506 const char *expr = nullptr;
508 if (command[0] == '\0') {
509 GetMultilineExpression();
510 return result.Succeeded();
513 if (command[0] == '-') {
514 // We have some options and these options MUST end with --.
515 const char *end_options = nullptr;
516 const char *s = command;
518 end_options = ::strstr(s, "--");
520 end_options += 2; // Get past the "--"
521 if (::isspace(end_options[0])) {
523 while (::isspace(*expr))
532 Args args(llvm::StringRef(command, end_options - command));
533 if (!ParseOptions(args, result))
536 Status error(m_option_group.NotifyOptionParsingFinished(&exe_ctx));
538 result.AppendError(error.AsCString());
539 result.SetStatus(eReturnStatusFailed);
543 if (m_repl_option.GetOptionValue().GetCurrentValue()) {
544 Target *target = m_interpreter.GetExecutionContext().GetTargetPtr();
547 m_expr_lines.clear();
548 m_expr_line_count = 0;
550 Debugger &debugger = target->GetDebugger();
552 // Check if the LLDB command interpreter is sitting on top of a REPL
555 if (debugger.CheckTopIOHandlerTypes(
556 IOHandler::Type::CommandInterpreter, IOHandler::Type::REPL)) {
557 // the LLDB command interpreter is sitting on top of a REPL that
559 // so just say the command interpreter is done and fall back to the
561 m_interpreter.GetIOHandler(false)->SetIsDone(true);
563 // We are launching the REPL on top of the current LLDB command
566 bool initialize = false;
568 REPLSP repl_sp(target->GetREPL(
569 repl_error, m_command_options.language, nullptr, false));
573 repl_sp = target->GetREPL(repl_error, m_command_options.language,
575 if (!repl_error.Success()) {
576 result.SetError(repl_error);
577 return result.Succeeded();
583 repl_sp->SetCommandOptions(m_command_options);
584 repl_sp->SetFormatOptions(m_format_options);
585 repl_sp->SetValueObjectDisplayOptions(m_varobj_options);
588 IOHandlerSP io_handler_sp(repl_sp->GetIOHandler());
590 io_handler_sp->SetIsDone(false);
592 debugger.PushIOHandler(io_handler_sp);
594 repl_error.SetErrorStringWithFormat(
595 "Couldn't create a REPL for %s",
596 Language::GetNameForLanguageType(m_command_options.language));
597 result.SetError(repl_error);
598 return result.Succeeded();
603 // No expression following options
604 else if (expr == nullptr || expr[0] == '\0') {
605 GetMultilineExpression();
606 return result.Succeeded();
614 if (EvaluateExpression(expr, &(result.GetOutputStream()),
615 &(result.GetErrorStream()), &result)) {
616 Target *target = m_interpreter.GetExecutionContext().GetTargetPtr();
618 target = GetDummyTarget();
620 if (!m_fixed_expression.empty() && target->GetEnableNotifyAboutFixIts()) {
621 CommandHistory &history = m_interpreter.GetCommandHistory();
622 // FIXME: Can we figure out what the user actually typed (e.g. some alias
624 // If we can it would be nice to show that.
625 std::string fixed_command("expression ");
627 fixed_command.append(m_fixed_expression);
629 // Add in any options that might have been in the original command:
630 fixed_command.append(command, expr - command);
631 fixed_command.append(m_fixed_expression);
633 history.AppendString(fixed_command);
638 result.SetStatus(eReturnStatusFailed);