1 //===-- CommandObjectExpression.cpp -----------------------------*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 10 // C Includes 11 // C++ Includes 12 // Other libraries and framework includes 13 #include "llvm/ADT/STLExtras.h" 14 #include "llvm/ADT/StringRef.h" 15 16 // Project includes 17 #include "CommandObjectExpression.h" 18 #include "lldb/Core/Value.h" 19 #include "lldb/Core/ValueObjectVariable.h" 20 #include "lldb/DataFormatters/ValueObjectPrinter.h" 21 #include "Plugins/ExpressionParser/Clang/ClangExpressionVariable.h" 22 #include "lldb/Expression/UserExpression.h" 23 #include "lldb/Expression/DWARFExpression.h" 24 #include "lldb/Expression/REPL.h" 25 #include "lldb/Host/Host.h" 26 #include "lldb/Host/StringConvert.h" 27 #include "lldb/Core/Debugger.h" 28 #include "lldb/Interpreter/CommandInterpreter.h" 29 #include "lldb/Interpreter/CommandReturnObject.h" 30 #include "lldb/Target/Language.h" 31 #include "lldb/Symbol/ObjectFile.h" 32 #include "lldb/Symbol/Variable.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" 37 38 using namespace lldb; 39 using namespace lldb_private; 40 41 CommandObjectExpression::CommandOptions::CommandOptions () : 42 OptionGroup() 43 { 44 } 45 46 CommandObjectExpression::CommandOptions::~CommandOptions() = default; 47 48 static OptionEnumValueElement g_description_verbosity_type[] = 49 { 50 { eLanguageRuntimeDescriptionDisplayVerbosityCompact, "compact", "Only show the description string"}, 51 { eLanguageRuntimeDescriptionDisplayVerbosityFull, "full", "Show the full output, including persistent variable's name and type"}, 52 { 0, nullptr, nullptr } 53 }; 54 55 OptionDefinition 56 CommandObjectExpression::CommandOptions::g_option_table[] = 57 { 58 { 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."}, 59 { LLDB_OPT_SET_1 | LLDB_OPT_SET_2, false, "ignore-breakpoints", 'i', OptionParser::eRequiredArgument, nullptr, nullptr, 0, eArgTypeBoolean, "Ignore breakpoint hits while running expressions"}, 60 { 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."}, 61 { 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. Note, unlike gdb hitting a breakpoint is controlled by another option (-i)."}, 62 { 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 and forcing breakpoints to not be ignored (-i0) and no unwinding to happen on error (-u0)."}, 63 { 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 setting is used." }, 64 { LLDB_OPT_SET_1 | LLDB_OPT_SET_2, false, "apply-fixits", 'X', OptionParser::eRequiredArgument, nullptr, nullptr, 0, eArgTypeLanguage, "If true, simple FixIt hints will be automatically applied to the expression." }, 65 { 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."}, 66 { LLDB_OPT_SET_1 | LLDB_OPT_SET_2, false, "top-level", 'p', OptionParser::eNoArgument , NULL, NULL, 0, eArgTypeNone, "Interpret the expression as top-level definitions rather than code to be immediately executed."} 67 }; 68 69 uint32_t 70 CommandObjectExpression::CommandOptions::GetNumDefinitions () 71 { 72 return llvm::array_lengthof(g_option_table); 73 } 74 75 Error 76 CommandObjectExpression::CommandOptions::SetOptionValue (CommandInterpreter &interpreter, 77 uint32_t option_idx, 78 const char *option_arg) 79 { 80 Error error; 81 82 const int short_option = g_option_table[option_idx].short_option; 83 84 switch (short_option) 85 { 86 case 'l': 87 language = Language::GetLanguageTypeFromString (option_arg); 88 if (language == eLanguageTypeUnknown) 89 error.SetErrorStringWithFormat ("unknown language type: '%s' for expression", option_arg); 90 break; 91 92 case 'a': 93 { 94 bool success; 95 bool result; 96 result = Args::StringToBoolean(option_arg, true, &success); 97 if (!success) 98 error.SetErrorStringWithFormat("invalid all-threads value setting: \"%s\"", option_arg); 99 else 100 try_all_threads = result; 101 } 102 break; 103 104 case 'i': 105 { 106 bool success; 107 bool tmp_value = Args::StringToBoolean(option_arg, true, &success); 108 if (success) 109 ignore_breakpoints = tmp_value; 110 else 111 error.SetErrorStringWithFormat("could not convert \"%s\" to a boolean value.", option_arg); 112 break; 113 } 114 case 't': 115 { 116 bool success; 117 uint32_t result; 118 result = StringConvert::ToUInt32(option_arg, 0, 0, &success); 119 if (success) 120 timeout = result; 121 else 122 error.SetErrorStringWithFormat ("invalid timeout setting \"%s\"", option_arg); 123 } 124 break; 125 126 case 'u': 127 { 128 bool success; 129 bool tmp_value = Args::StringToBoolean(option_arg, true, &success); 130 if (success) 131 unwind_on_error = tmp_value; 132 else 133 error.SetErrorStringWithFormat("could not convert \"%s\" to a boolean value.", option_arg); 134 break; 135 } 136 137 case 'v': 138 if (!option_arg) 139 { 140 m_verbosity = eLanguageRuntimeDescriptionDisplayVerbosityFull; 141 break; 142 } 143 m_verbosity = (LanguageRuntimeDescriptionDisplayVerbosity) Args::StringToOptionEnum(option_arg, g_option_table[option_idx].enum_values, 0, error); 144 if (!error.Success()) 145 error.SetErrorStringWithFormat ("unrecognized value for description-verbosity '%s'", option_arg); 146 break; 147 148 case 'g': 149 debug = true; 150 unwind_on_error = false; 151 ignore_breakpoints = false; 152 break; 153 154 case 'p': 155 top_level = true; 156 break; 157 158 case 'X': 159 { 160 bool success; 161 bool tmp_value = Args::StringToBoolean(option_arg, true, &success); 162 if (success) 163 auto_apply_fixits = tmp_value ? eLazyBoolYes : eLazyBoolNo; 164 else 165 error.SetErrorStringWithFormat("could not convert \"%s\" to a boolean value.", option_arg); 166 break; 167 } 168 169 default: 170 error.SetErrorStringWithFormat("invalid short option character '%c'", short_option); 171 break; 172 } 173 174 return error; 175 } 176 177 void 178 CommandObjectExpression::CommandOptions::OptionParsingStarting (CommandInterpreter &interpreter) 179 { 180 Process *process = interpreter.GetExecutionContext().GetProcessPtr(); 181 if (process != nullptr) 182 { 183 ignore_breakpoints = process->GetIgnoreBreakpointsInExpressions(); 184 unwind_on_error = process->GetUnwindOnErrorInExpressions(); 185 } 186 else 187 { 188 ignore_breakpoints = true; 189 unwind_on_error = true; 190 } 191 192 show_summary = true; 193 try_all_threads = true; 194 timeout = 0; 195 debug = false; 196 language = eLanguageTypeUnknown; 197 m_verbosity = eLanguageRuntimeDescriptionDisplayVerbosityCompact; 198 auto_apply_fixits = eLazyBoolCalculate; 199 top_level = false; 200 } 201 202 const OptionDefinition* 203 CommandObjectExpression::CommandOptions::GetDefinitions () 204 { 205 return g_option_table; 206 } 207 208 CommandObjectExpression::CommandObjectExpression (CommandInterpreter &interpreter) : 209 CommandObjectRaw(interpreter, 210 "expression", 211 "Evaluate an expression in the current program context, using user defined variables and variables currently in scope.", 212 nullptr, 213 eCommandProcessMustBePaused | eCommandTryTargetAPILock), 214 IOHandlerDelegate (IOHandlerDelegate::Completion::Expression), 215 m_option_group (interpreter), 216 m_format_options (eFormatDefault), 217 m_repl_option (LLDB_OPT_SET_1, false, "repl", 'r', "Drop into REPL", false, true), 218 m_command_options (), 219 m_expr_line_count (0), 220 m_expr_lines () 221 { 222 SetHelpLong( 223 R"( 224 Timeouts: 225 226 )" " If the expression can be evaluated statically (without running code) then it will be. \ 227 Otherwise, by default the expression will run on the current thread with a short timeout: \ 228 currently .25 seconds. If it doesn't return in that time, the evaluation will be interrupted \ 229 and resumed with all threads running. You can use the -a option to disable retrying on all \ 230 threads. You can use the -t option to set a shorter timeout." R"( 231 232 User defined variables: 233 234 )" " You can define your own variables for convenience or to be used in subsequent expressions. \ 235 You define them the same way you would define variables in C. If the first character of \ 236 your user defined variable is a $, then the variable's value will be available in future \ 237 expressions, otherwise it will just be available in the current expression." R"( 238 239 Continuing evaluation after a breakpoint: 240 241 )" " If the \"-i false\" option is used, and execution is interrupted by a breakpoint hit, once \ 242 you are done with your investigation, you can either remove the expression execution frames \ 243 from the stack with \"thread return -x\" or if you are still interested in the expression result \ 244 you can issue the \"continue\" command and the expression evaluation will complete and the \ 245 expression result will be available using the \"thread.completed-expression\" key in the thread \ 246 format." R"( 247 248 Examples: 249 250 expr my_struct->a = my_array[3] 251 expr -f bin -- (index * 8) + 5 252 expr unsigned int $foo = 5 253 expr char c[] = \"foo\"; c[0])" 254 ); 255 256 CommandArgumentEntry arg; 257 CommandArgumentData expression_arg; 258 259 // Define the first (and only) variant of this arg. 260 expression_arg.arg_type = eArgTypeExpression; 261 expression_arg.arg_repetition = eArgRepeatPlain; 262 263 // There is only one variant this argument could be; put it into the argument entry. 264 arg.push_back (expression_arg); 265 266 // Push the data for the first argument into the m_arguments vector. 267 m_arguments.push_back (arg); 268 269 // Add the "--format" and "--gdb-format" 270 m_option_group.Append (&m_format_options, OptionGroupFormat::OPTION_GROUP_FORMAT | OptionGroupFormat::OPTION_GROUP_GDB_FMT, LLDB_OPT_SET_1); 271 m_option_group.Append (&m_command_options); 272 m_option_group.Append (&m_varobj_options, LLDB_OPT_SET_ALL, LLDB_OPT_SET_1 | LLDB_OPT_SET_2); 273 m_option_group.Append (&m_repl_option, LLDB_OPT_SET_ALL, LLDB_OPT_SET_3); 274 m_option_group.Finalize(); 275 } 276 277 CommandObjectExpression::~CommandObjectExpression() = default; 278 279 Options * 280 CommandObjectExpression::GetOptions () 281 { 282 return &m_option_group; 283 } 284 285 static lldb_private::Error 286 CanBeUsedForElementCountPrinting (ValueObject& valobj) 287 { 288 CompilerType type(valobj.GetCompilerType()); 289 CompilerType pointee; 290 if (!type.IsPointerType(&pointee)) 291 return Error("as it does not refer to a pointer"); 292 if (pointee.IsVoidType()) 293 return Error("as it refers to a pointer to void"); 294 return Error(); 295 } 296 297 bool 298 CommandObjectExpression::EvaluateExpression(const char *expr, 299 Stream *output_stream, 300 Stream *error_stream, 301 CommandReturnObject *result) 302 { 303 // Don't use m_exe_ctx as this might be called asynchronously 304 // after the command object DoExecute has finished when doing 305 // multi-line expression that use an input reader... 306 ExecutionContext exe_ctx (m_interpreter.GetExecutionContext()); 307 308 Target *target = exe_ctx.GetTargetPtr(); 309 310 if (!target) 311 target = GetDummyTarget(); 312 313 if (target) 314 { 315 lldb::ValueObjectSP result_valobj_sp; 316 bool keep_in_memory = true; 317 StackFrame *frame = exe_ctx.GetFramePtr(); 318 319 EvaluateExpressionOptions options; 320 options.SetCoerceToId(m_varobj_options.use_objc); 321 options.SetUnwindOnError(m_command_options.unwind_on_error); 322 options.SetIgnoreBreakpoints (m_command_options.ignore_breakpoints); 323 options.SetKeepInMemory(keep_in_memory); 324 options.SetUseDynamic(m_varobj_options.use_dynamic); 325 options.SetTryAllThreads(m_command_options.try_all_threads); 326 options.SetDebug(m_command_options.debug); 327 options.SetLanguage(m_command_options.language); 328 329 bool auto_apply_fixits; 330 if (m_command_options.auto_apply_fixits == eLazyBoolCalculate) 331 auto_apply_fixits = target->GetEnableAutoApplyFixIts(); 332 else 333 auto_apply_fixits = m_command_options.auto_apply_fixits == eLazyBoolYes ? true : false; 334 335 options.SetAutoApplyFixIts(auto_apply_fixits); 336 337 if (m_command_options.top_level) 338 options.SetExecutionPolicy(eExecutionPolicyTopLevel); 339 340 // If there is any chance we are going to stop and want to see 341 // what went wrong with our expression, we should generate debug info 342 if (!m_command_options.ignore_breakpoints || 343 !m_command_options.unwind_on_error) 344 options.SetGenerateDebugInfo(true); 345 346 if (m_command_options.timeout > 0) 347 options.SetTimeoutUsec(m_command_options.timeout); 348 else 349 options.SetTimeoutUsec(0); 350 351 ExpressionResults success = target->EvaluateExpression(expr, frame, result_valobj_sp, options, &m_fixed_expression); 352 353 // We only tell you about the FixIt if we applied it. The compiler errors will suggest the FixIt if it parsed. 354 if (error_stream && !m_fixed_expression.empty() && target->GetEnableNotifyAboutFixIts()) 355 { 356 if (success == eExpressionCompleted) 357 error_stream->Printf (" Fixit applied, fixed expression was: \n %s\n", m_fixed_expression.c_str()); 358 } 359 360 if (result_valobj_sp) 361 { 362 Format format = m_format_options.GetFormat(); 363 364 if (result_valobj_sp->GetError().Success()) 365 { 366 if (format != eFormatVoid) 367 { 368 if (format != eFormatDefault) 369 result_valobj_sp->SetFormat (format); 370 371 if (m_varobj_options.elem_count > 0) 372 { 373 Error error(CanBeUsedForElementCountPrinting(*result_valobj_sp)); 374 if (error.Fail()) 375 { 376 result->AppendErrorWithFormat("expression cannot be used with --element-count %s\n", error.AsCString("")); 377 result->SetStatus(eReturnStatusFailed); 378 return false; 379 } 380 } 381 382 DumpValueObjectOptions options(m_varobj_options.GetAsDumpOptions(m_command_options.m_verbosity,format)); 383 options.SetVariableFormatDisplayLanguage(result_valobj_sp->GetPreferredDisplayLanguage()); 384 385 result_valobj_sp->Dump(*output_stream,options); 386 387 if (result) 388 result->SetStatus (eReturnStatusSuccessFinishResult); 389 } 390 } 391 else 392 { 393 if (result_valobj_sp->GetError().GetError() == UserExpression::kNoResult) 394 { 395 if (format != eFormatVoid && m_interpreter.GetDebugger().GetNotifyVoid()) 396 { 397 error_stream->PutCString("(void)\n"); 398 } 399 400 if (result) 401 result->SetStatus (eReturnStatusSuccessFinishResult); 402 } 403 else 404 { 405 const char *error_cstr = result_valobj_sp->GetError().AsCString(); 406 if (error_cstr && error_cstr[0]) 407 { 408 const size_t error_cstr_len = strlen (error_cstr); 409 const bool ends_with_newline = error_cstr[error_cstr_len - 1] == '\n'; 410 if (strstr(error_cstr, "error:") != error_cstr) 411 error_stream->PutCString ("error: "); 412 error_stream->Write(error_cstr, error_cstr_len); 413 if (!ends_with_newline) 414 error_stream->EOL(); 415 } 416 else 417 { 418 error_stream->PutCString ("error: unknown error\n"); 419 } 420 421 if (result) 422 result->SetStatus (eReturnStatusFailed); 423 } 424 } 425 } 426 } 427 else 428 { 429 error_stream->Printf ("error: invalid execution context for expression\n"); 430 return false; 431 } 432 433 return true; 434 } 435 436 void 437 CommandObjectExpression::IOHandlerInputComplete (IOHandler &io_handler, std::string &line) 438 { 439 io_handler.SetIsDone(true); 440 // StreamSP output_stream = io_handler.GetDebugger().GetAsyncOutputStream(); 441 // StreamSP error_stream = io_handler.GetDebugger().GetAsyncErrorStream(); 442 StreamFileSP output_sp(io_handler.GetOutputStreamFile()); 443 StreamFileSP error_sp(io_handler.GetErrorStreamFile()); 444 445 EvaluateExpression (line.c_str(), 446 output_sp.get(), 447 error_sp.get()); 448 if (output_sp) 449 output_sp->Flush(); 450 if (error_sp) 451 error_sp->Flush(); 452 } 453 454 bool 455 CommandObjectExpression::IOHandlerIsInputComplete (IOHandler &io_handler, 456 StringList &lines) 457 { 458 // An empty lines is used to indicate the end of input 459 const size_t num_lines = lines.GetSize(); 460 if (num_lines > 0 && lines[num_lines - 1].empty()) 461 { 462 // Remove the last empty line from "lines" so it doesn't appear 463 // in our resulting input and return true to indicate we are done 464 // getting lines 465 lines.PopBack(); 466 return true; 467 } 468 return false; 469 } 470 471 void 472 CommandObjectExpression::GetMultilineExpression () 473 { 474 m_expr_lines.clear(); 475 m_expr_line_count = 0; 476 477 Debugger &debugger = GetCommandInterpreter().GetDebugger(); 478 bool color_prompt = debugger.GetUseColor(); 479 const bool multiple_lines = true; // Get multiple lines 480 IOHandlerSP io_handler_sp(new IOHandlerEditline(debugger, 481 IOHandler::Type::Expression, 482 "lldb-expr", // Name of input reader for history 483 nullptr, // No prompt 484 nullptr, // Continuation prompt 485 multiple_lines, 486 color_prompt, 487 1, // Show line numbers starting at 1 488 *this)); 489 490 StreamFileSP output_sp(io_handler_sp->GetOutputStreamFile()); 491 if (output_sp) 492 { 493 output_sp->PutCString("Enter expressions, then terminate with an empty line to evaluate:\n"); 494 output_sp->Flush(); 495 } 496 debugger.PushIOHandler(io_handler_sp); 497 } 498 499 bool 500 CommandObjectExpression::DoExecute(const char *command, 501 CommandReturnObject &result) 502 { 503 m_fixed_expression.clear(); 504 m_option_group.NotifyOptionParsingStarting(); 505 506 const char * expr = nullptr; 507 508 if (command[0] == '\0') 509 { 510 GetMultilineExpression (); 511 return result.Succeeded(); 512 } 513 514 if (command[0] == '-') 515 { 516 // We have some options and these options MUST end with --. 517 const char *end_options = nullptr; 518 const char *s = command; 519 while (s && s[0]) 520 { 521 end_options = ::strstr (s, "--"); 522 if (end_options) 523 { 524 end_options += 2; // Get past the "--" 525 if (::isspace (end_options[0])) 526 { 527 expr = end_options; 528 while (::isspace (*expr)) 529 ++expr; 530 break; 531 } 532 } 533 s = end_options; 534 } 535 536 if (end_options) 537 { 538 Args args (llvm::StringRef(command, end_options - command)); 539 if (!ParseOptions (args, result)) 540 return false; 541 542 Error error (m_option_group.NotifyOptionParsingFinished()); 543 if (error.Fail()) 544 { 545 result.AppendError (error.AsCString()); 546 result.SetStatus (eReturnStatusFailed); 547 return false; 548 } 549 550 if (m_repl_option.GetOptionValue().GetCurrentValue()) 551 { 552 Target *target = m_interpreter.GetExecutionContext().GetTargetPtr(); 553 if (target) 554 { 555 // Drop into REPL 556 m_expr_lines.clear(); 557 m_expr_line_count = 0; 558 559 Debugger &debugger = target->GetDebugger(); 560 561 // Check if the LLDB command interpreter is sitting on top of a REPL that 562 // launched it... 563 if (debugger.CheckTopIOHandlerTypes(IOHandler::Type::CommandInterpreter, IOHandler::Type::REPL)) 564 { 565 // the LLDB command interpreter is sitting on top of a REPL that launched it, 566 // so just say the command interpreter is done and fall back to the existing REPL 567 m_interpreter.GetIOHandler(false)->SetIsDone(true); 568 } 569 else 570 { 571 // We are launching the REPL on top of the current LLDB command interpreter, 572 // so just push one 573 bool initialize = false; 574 Error repl_error; 575 REPLSP repl_sp (target->GetREPL(repl_error, m_command_options.language, nullptr, false)); 576 577 if (!repl_sp) 578 { 579 initialize = true; 580 repl_sp = target->GetREPL(repl_error, m_command_options.language, nullptr, true); 581 if (!repl_error.Success()) 582 { 583 result.SetError(repl_error); 584 return result.Succeeded(); 585 } 586 } 587 588 if (repl_sp) 589 { 590 if (initialize) 591 { 592 repl_sp->SetCommandOptions(m_command_options); 593 repl_sp->SetFormatOptions(m_format_options); 594 repl_sp->SetValueObjectDisplayOptions(m_varobj_options); 595 } 596 597 IOHandlerSP io_handler_sp (repl_sp->GetIOHandler()); 598 599 io_handler_sp->SetIsDone(false); 600 601 debugger.PushIOHandler(io_handler_sp); 602 } 603 else 604 { 605 repl_error.SetErrorStringWithFormat("Couldn't create a REPL for %s", Language::GetNameForLanguageType(m_command_options.language)); 606 result.SetError(repl_error); 607 return result.Succeeded(); 608 } 609 } 610 } 611 } 612 // No expression following options 613 else if (expr == nullptr || expr[0] == '\0') 614 { 615 GetMultilineExpression (); 616 return result.Succeeded(); 617 } 618 } 619 } 620 621 if (expr == nullptr) 622 expr = command; 623 624 if (EvaluateExpression (expr, &(result.GetOutputStream()), &(result.GetErrorStream()), &result)) 625 { 626 Target *target = m_interpreter.GetExecutionContext().GetTargetPtr(); 627 if (!m_fixed_expression.empty() && target->GetEnableNotifyAboutFixIts()) 628 { 629 CommandHistory &history = m_interpreter.GetCommandHistory(); 630 // FIXME: Can we figure out what the user actually typed (e.g. some alias for expr???) 631 // If we can it would be nice to show that. 632 std::string fixed_command("expression "); 633 if (expr == command) 634 fixed_command.append(m_fixed_expression); 635 else 636 { 637 // Add in any options that might have been in the original command: 638 fixed_command.append(command, expr - command); 639 fixed_command.append(m_fixed_expression); 640 } 641 history.AppendString(fixed_command); 642 } 643 return true; 644 } 645 646 result.SetStatus (eReturnStatusFailed); 647 return false; 648 } 649