1 //===-- CommandObjectWatchpointCommand.cpp --------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #include <vector> 10 11 #include "CommandObjectWatchpoint.h" 12 #include "CommandObjectWatchpointCommand.h" 13 #include "lldb/Breakpoint/StoppointCallbackContext.h" 14 #include "lldb/Breakpoint/Watchpoint.h" 15 #include "lldb/Core/IOHandler.h" 16 #include "lldb/Host/OptionParser.h" 17 #include "lldb/Interpreter/CommandInterpreter.h" 18 #include "lldb/Interpreter/CommandReturnObject.h" 19 #include "lldb/Interpreter/OptionArgParser.h" 20 #include "lldb/Target/Target.h" 21 22 using namespace lldb; 23 using namespace lldb_private; 24 25 // FIXME: "script-type" needs to have its contents determined dynamically, so 26 // somebody can add a new scripting language to lldb and have it pickable here 27 // without having to change this enumeration by hand and rebuild lldb proper. 28 static constexpr OptionEnumValueElement g_script_option_enumeration[] = { 29 { 30 eScriptLanguageNone, 31 "command", 32 "Commands are in the lldb command interpreter language", 33 }, 34 { 35 eScriptLanguagePython, 36 "python", 37 "Commands are in the Python language.", 38 }, 39 { 40 eScriptLanguageLua, 41 "lua", 42 "Commands are in the Lua language.", 43 }, 44 { 45 eSortOrderByName, 46 "default-script", 47 "Commands are in the default scripting language.", 48 }, 49 }; 50 51 static constexpr OptionEnumValues ScriptOptionEnum() { 52 return OptionEnumValues(g_script_option_enumeration); 53 } 54 55 #define LLDB_OPTIONS_watchpoint_command_add 56 #include "CommandOptions.inc" 57 58 class CommandObjectWatchpointCommandAdd : public CommandObjectParsed, 59 public IOHandlerDelegateMultiline { 60 public: 61 CommandObjectWatchpointCommandAdd(CommandInterpreter &interpreter) 62 : CommandObjectParsed(interpreter, "add", 63 "Add a set of LLDB commands to a watchpoint, to be " 64 "executed whenever the watchpoint is hit.", 65 nullptr, eCommandRequiresTarget), 66 IOHandlerDelegateMultiline("DONE", 67 IOHandlerDelegate::Completion::LLDBCommand), 68 m_options() { 69 SetHelpLong( 70 R"( 71 General information about entering watchpoint commands 72 ------------------------------------------------------ 73 74 )" 75 "This command will prompt for commands to be executed when the specified \ 76 watchpoint is hit. Each command is typed on its own line following the '> ' \ 77 prompt until 'DONE' is entered." 78 R"( 79 80 )" 81 "Syntactic errors may not be detected when initially entered, and many \ 82 malformed commands can silently fail when executed. If your watchpoint commands \ 83 do not appear to be executing, double-check the command syntax." 84 R"( 85 86 )" 87 "Note: You may enter any debugger command exactly as you would at the debugger \ 88 prompt. There is no limit to the number of commands supplied, but do NOT enter \ 89 more than one command per line." 90 R"( 91 92 Special information about PYTHON watchpoint commands 93 ---------------------------------------------------- 94 95 )" 96 "You may enter either one or more lines of Python, including function \ 97 definitions or calls to functions that will have been imported by the time \ 98 the code executes. Single line watchpoint commands will be interpreted 'as is' \ 99 when the watchpoint is hit. Multiple lines of Python will be wrapped in a \ 100 generated function, and a call to the function will be attached to the watchpoint." 101 R"( 102 103 This auto-generated function is passed in three arguments: 104 105 frame: an lldb.SBFrame object for the frame which hit the watchpoint. 106 107 wp: the watchpoint that was hit. 108 109 )" 110 "When specifying a python function with the --python-function option, you need \ 111 to supply the function name prepended by the module name:" 112 R"( 113 114 --python-function myutils.watchpoint_callback 115 116 The function itself must have the following prototype: 117 118 def watchpoint_callback(frame, wp): 119 # Your code goes here 120 121 )" 122 "The arguments are the same as the arguments passed to generated functions as \ 123 described above. Note that the global variable 'lldb.frame' will NOT be updated when \ 124 this function is called, so be sure to use the 'frame' argument. The 'frame' argument \ 125 can get you to the thread via frame.GetThread(), the thread can get you to the \ 126 process via thread.GetProcess(), and the process can get you back to the target \ 127 via process.GetTarget()." 128 R"( 129 130 )" 131 "Important Note: As Python code gets collected into functions, access to global \ 132 variables requires explicit scoping using the 'global' keyword. Be sure to use correct \ 133 Python syntax, including indentation, when entering Python watchpoint commands." 134 R"( 135 136 Example Python one-line watchpoint command: 137 138 (lldb) watchpoint command add -s python 1 139 Enter your Python command(s). Type 'DONE' to end. 140 > print "Hit this watchpoint!" 141 > DONE 142 143 As a convenience, this also works for a short Python one-liner: 144 145 (lldb) watchpoint command add -s python 1 -o 'import time; print time.asctime()' 146 (lldb) run 147 Launching '.../a.out' (x86_64) 148 (lldb) Fri Sep 10 12:17:45 2010 149 Process 21778 Stopped 150 * thread #1: tid = 0x2e03, 0x0000000100000de8 a.out`c + 7 at main.c:39, stop reason = watchpoint 1.1, queue = com.apple.main-thread 151 36 152 37 int c(int val) 153 38 { 154 39 -> return val + 3; 155 40 } 156 41 157 42 int main (int argc, char const *argv[]) 158 159 Example multiple line Python watchpoint command, using function definition: 160 161 (lldb) watchpoint command add -s python 1 162 Enter your Python command(s). Type 'DONE' to end. 163 > def watchpoint_output (wp_no): 164 > out_string = "Hit watchpoint number " + repr (wp_no) 165 > print out_string 166 > return True 167 > watchpoint_output (1) 168 > DONE 169 170 Example multiple line Python watchpoint command, using 'loose' Python: 171 172 (lldb) watchpoint command add -s p 1 173 Enter your Python command(s). Type 'DONE' to end. 174 > global wp_count 175 > wp_count = wp_count + 1 176 > print "Hit this watchpoint " + repr(wp_count) + " times!" 177 > DONE 178 179 )" 180 "In this case, since there is a reference to a global variable, \ 181 'wp_count', you will also need to make sure 'wp_count' exists and is \ 182 initialized:" 183 R"( 184 185 (lldb) script 186 >>> wp_count = 0 187 >>> quit() 188 189 )" 190 "Final Note: A warning that no watchpoint command was generated when there \ 191 are no syntax errors may indicate that a function was declared but never called."); 192 193 CommandArgumentEntry arg; 194 CommandArgumentData wp_id_arg; 195 196 // Define the first (and only) variant of this arg. 197 wp_id_arg.arg_type = eArgTypeWatchpointID; 198 wp_id_arg.arg_repetition = eArgRepeatPlain; 199 200 // There is only one variant this argument could be; put it into the 201 // argument entry. 202 arg.push_back(wp_id_arg); 203 204 // Push the data for the first argument into the m_arguments vector. 205 m_arguments.push_back(arg); 206 } 207 208 ~CommandObjectWatchpointCommandAdd() override = default; 209 210 Options *GetOptions() override { return &m_options; } 211 212 void IOHandlerActivated(IOHandler &io_handler, bool interactive) override { 213 StreamFileSP output_sp(io_handler.GetOutputStreamFileSP()); 214 if (output_sp && interactive) { 215 output_sp->PutCString( 216 "Enter your debugger command(s). Type 'DONE' to end.\n"); 217 output_sp->Flush(); 218 } 219 } 220 221 void IOHandlerInputComplete(IOHandler &io_handler, 222 std::string &line) override { 223 io_handler.SetIsDone(true); 224 225 // The WatchpointOptions object is owned by the watchpoint or watchpoint 226 // location 227 WatchpointOptions *wp_options = 228 (WatchpointOptions *)io_handler.GetUserData(); 229 if (wp_options) { 230 std::unique_ptr<WatchpointOptions::CommandData> data_up( 231 new WatchpointOptions::CommandData()); 232 if (data_up) { 233 data_up->user_source.SplitIntoLines(line); 234 auto baton_sp = std::make_shared<WatchpointOptions::CommandBaton>( 235 std::move(data_up)); 236 wp_options->SetCallback(WatchpointOptionsCallbackFunction, baton_sp); 237 } 238 } 239 } 240 241 void CollectDataForWatchpointCommandCallback(WatchpointOptions *wp_options, 242 CommandReturnObject &result) { 243 m_interpreter.GetLLDBCommandsFromIOHandler( 244 "> ", // Prompt 245 *this, // IOHandlerDelegate 246 wp_options); // Baton for the "io_handler" that will be passed back into 247 // our IOHandlerDelegate functions 248 } 249 250 /// Set a one-liner as the callback for the watchpoint. 251 void SetWatchpointCommandCallback(WatchpointOptions *wp_options, 252 const char *oneliner) { 253 std::unique_ptr<WatchpointOptions::CommandData> data_up( 254 new WatchpointOptions::CommandData()); 255 256 // It's necessary to set both user_source and script_source to the 257 // oneliner. The former is used to generate callback description (as in 258 // watchpoint command list) while the latter is used for Python to 259 // interpret during the actual callback. 260 data_up->user_source.AppendString(oneliner); 261 data_up->script_source.assign(oneliner); 262 data_up->stop_on_error = m_options.m_stop_on_error; 263 264 auto baton_sp = 265 std::make_shared<WatchpointOptions::CommandBaton>(std::move(data_up)); 266 wp_options->SetCallback(WatchpointOptionsCallbackFunction, baton_sp); 267 } 268 269 static bool 270 WatchpointOptionsCallbackFunction(void *baton, 271 StoppointCallbackContext *context, 272 lldb::user_id_t watch_id) { 273 bool ret_value = true; 274 if (baton == nullptr) 275 return true; 276 277 WatchpointOptions::CommandData *data = 278 (WatchpointOptions::CommandData *)baton; 279 StringList &commands = data->user_source; 280 281 if (commands.GetSize() > 0) { 282 ExecutionContext exe_ctx(context->exe_ctx_ref); 283 Target *target = exe_ctx.GetTargetPtr(); 284 if (target) { 285 Debugger &debugger = target->GetDebugger(); 286 CommandReturnObject result(debugger.GetUseColor()); 287 288 // Rig up the results secondary output stream to the debugger's, so the 289 // output will come out synchronously if the debugger is set up that 290 // way. 291 StreamSP output_stream(debugger.GetAsyncOutputStream()); 292 StreamSP error_stream(debugger.GetAsyncErrorStream()); 293 result.SetImmediateOutputStream(output_stream); 294 result.SetImmediateErrorStream(error_stream); 295 296 CommandInterpreterRunOptions options; 297 options.SetStopOnContinue(true); 298 options.SetStopOnError(data->stop_on_error); 299 options.SetEchoCommands(false); 300 options.SetPrintResults(true); 301 options.SetPrintErrors(true); 302 options.SetAddToHistory(false); 303 304 debugger.GetCommandInterpreter().HandleCommands(commands, &exe_ctx, 305 options, result); 306 result.GetImmediateOutputStream()->Flush(); 307 result.GetImmediateErrorStream()->Flush(); 308 } 309 } 310 return ret_value; 311 } 312 313 class CommandOptions : public Options { 314 public: 315 CommandOptions() 316 : Options(), m_use_commands(false), m_use_script_language(false), 317 m_script_language(eScriptLanguageNone), m_use_one_liner(false), 318 m_one_liner(), m_function_name() {} 319 320 ~CommandOptions() override = default; 321 322 Status SetOptionValue(uint32_t option_idx, llvm::StringRef option_arg, 323 ExecutionContext *execution_context) override { 324 Status error; 325 const int short_option = m_getopt_table[option_idx].val; 326 327 switch (short_option) { 328 case 'o': 329 m_use_one_liner = true; 330 m_one_liner = std::string(option_arg); 331 break; 332 333 case 's': 334 m_script_language = (lldb::ScriptLanguage)OptionArgParser::ToOptionEnum( 335 option_arg, GetDefinitions()[option_idx].enum_values, 336 eScriptLanguageNone, error); 337 338 switch (m_script_language) { 339 case eScriptLanguagePython: 340 case eScriptLanguageLua: 341 m_use_script_language = true; 342 break; 343 case eScriptLanguageNone: 344 case eScriptLanguageUnknown: 345 m_use_script_language = false; 346 break; 347 } 348 break; 349 350 case 'e': { 351 bool success = false; 352 m_stop_on_error = 353 OptionArgParser::ToBoolean(option_arg, false, &success); 354 if (!success) 355 error.SetErrorStringWithFormat( 356 "invalid value for stop-on-error: \"%s\"", 357 option_arg.str().c_str()); 358 } break; 359 360 case 'F': 361 m_use_one_liner = false; 362 m_function_name.assign(std::string(option_arg)); 363 break; 364 365 default: 366 llvm_unreachable("Unimplemented option"); 367 } 368 return error; 369 } 370 371 void OptionParsingStarting(ExecutionContext *execution_context) override { 372 m_use_commands = true; 373 m_use_script_language = false; 374 m_script_language = eScriptLanguageNone; 375 376 m_use_one_liner = false; 377 m_stop_on_error = true; 378 m_one_liner.clear(); 379 m_function_name.clear(); 380 } 381 382 llvm::ArrayRef<OptionDefinition> GetDefinitions() override { 383 return llvm::makeArrayRef(g_watchpoint_command_add_options); 384 } 385 386 // Instance variables to hold the values for command options. 387 388 bool m_use_commands; 389 bool m_use_script_language; 390 lldb::ScriptLanguage m_script_language; 391 392 // Instance variables to hold the values for one_liner options. 393 bool m_use_one_liner; 394 std::string m_one_liner; 395 bool m_stop_on_error; 396 std::string m_function_name; 397 }; 398 399 protected: 400 bool DoExecute(Args &command, CommandReturnObject &result) override { 401 Target *target = &GetSelectedTarget(); 402 403 const WatchpointList &watchpoints = target->GetWatchpointList(); 404 size_t num_watchpoints = watchpoints.GetSize(); 405 406 if (num_watchpoints == 0) { 407 result.AppendError("No watchpoints exist to have commands added"); 408 result.SetStatus(eReturnStatusFailed); 409 return false; 410 } 411 412 if (!m_options.m_function_name.empty()) { 413 if (!m_options.m_use_script_language) { 414 m_options.m_script_language = GetDebugger().GetScriptLanguage(); 415 m_options.m_use_script_language = true; 416 } 417 } 418 419 std::vector<uint32_t> valid_wp_ids; 420 if (!CommandObjectMultiwordWatchpoint::VerifyWatchpointIDs(target, command, 421 valid_wp_ids)) { 422 result.AppendError("Invalid watchpoints specification."); 423 result.SetStatus(eReturnStatusFailed); 424 return false; 425 } 426 427 result.SetStatus(eReturnStatusSuccessFinishNoResult); 428 const size_t count = valid_wp_ids.size(); 429 for (size_t i = 0; i < count; ++i) { 430 uint32_t cur_wp_id = valid_wp_ids.at(i); 431 if (cur_wp_id != LLDB_INVALID_WATCH_ID) { 432 Watchpoint *wp = target->GetWatchpointList().FindByID(cur_wp_id).get(); 433 // Sanity check wp first. 434 if (wp == nullptr) 435 continue; 436 437 WatchpointOptions *wp_options = wp->GetOptions(); 438 // Skip this watchpoint if wp_options is not good. 439 if (wp_options == nullptr) 440 continue; 441 442 // If we are using script language, get the script interpreter in order 443 // to set or collect command callback. Otherwise, call the methods 444 // associated with this object. 445 if (m_options.m_use_script_language) { 446 ScriptInterpreter *script_interp = GetDebugger().GetScriptInterpreter( 447 /*can_create=*/true, m_options.m_script_language); 448 // Special handling for one-liner specified inline. 449 if (m_options.m_use_one_liner) { 450 script_interp->SetWatchpointCommandCallback( 451 wp_options, m_options.m_one_liner.c_str()); 452 } 453 // Special handling for using a Python function by name instead of 454 // extending the watchpoint callback data structures, we just 455 // automatize what the user would do manually: make their watchpoint 456 // command be a function call 457 else if (!m_options.m_function_name.empty()) { 458 std::string oneliner(m_options.m_function_name); 459 oneliner += "(frame, wp, internal_dict)"; 460 script_interp->SetWatchpointCommandCallback( 461 wp_options, oneliner.c_str()); 462 } else { 463 script_interp->CollectDataForWatchpointCommandCallback(wp_options, 464 result); 465 } 466 } else { 467 // Special handling for one-liner specified inline. 468 if (m_options.m_use_one_liner) 469 SetWatchpointCommandCallback(wp_options, 470 m_options.m_one_liner.c_str()); 471 else 472 CollectDataForWatchpointCommandCallback(wp_options, result); 473 } 474 } 475 } 476 477 return result.Succeeded(); 478 } 479 480 private: 481 CommandOptions m_options; 482 }; 483 484 // CommandObjectWatchpointCommandDelete 485 486 class CommandObjectWatchpointCommandDelete : public CommandObjectParsed { 487 public: 488 CommandObjectWatchpointCommandDelete(CommandInterpreter &interpreter) 489 : CommandObjectParsed(interpreter, "delete", 490 "Delete the set of commands from a watchpoint.", 491 nullptr, eCommandRequiresTarget) { 492 CommandArgumentEntry arg; 493 CommandArgumentData wp_id_arg; 494 495 // Define the first (and only) variant of this arg. 496 wp_id_arg.arg_type = eArgTypeWatchpointID; 497 wp_id_arg.arg_repetition = eArgRepeatPlain; 498 499 // There is only one variant this argument could be; put it into the 500 // argument entry. 501 arg.push_back(wp_id_arg); 502 503 // Push the data for the first argument into the m_arguments vector. 504 m_arguments.push_back(arg); 505 } 506 507 ~CommandObjectWatchpointCommandDelete() override = default; 508 509 protected: 510 bool DoExecute(Args &command, CommandReturnObject &result) override { 511 Target *target = &GetSelectedTarget(); 512 513 const WatchpointList &watchpoints = target->GetWatchpointList(); 514 size_t num_watchpoints = watchpoints.GetSize(); 515 516 if (num_watchpoints == 0) { 517 result.AppendError("No watchpoints exist to have commands deleted"); 518 result.SetStatus(eReturnStatusFailed); 519 return false; 520 } 521 522 if (command.GetArgumentCount() == 0) { 523 result.AppendError( 524 "No watchpoint specified from which to delete the commands"); 525 result.SetStatus(eReturnStatusFailed); 526 return false; 527 } 528 529 std::vector<uint32_t> valid_wp_ids; 530 if (!CommandObjectMultiwordWatchpoint::VerifyWatchpointIDs(target, command, 531 valid_wp_ids)) { 532 result.AppendError("Invalid watchpoints specification."); 533 result.SetStatus(eReturnStatusFailed); 534 return false; 535 } 536 537 result.SetStatus(eReturnStatusSuccessFinishNoResult); 538 const size_t count = valid_wp_ids.size(); 539 for (size_t i = 0; i < count; ++i) { 540 uint32_t cur_wp_id = valid_wp_ids.at(i); 541 if (cur_wp_id != LLDB_INVALID_WATCH_ID) { 542 Watchpoint *wp = target->GetWatchpointList().FindByID(cur_wp_id).get(); 543 if (wp) 544 wp->ClearCallback(); 545 } else { 546 result.AppendErrorWithFormat("Invalid watchpoint ID: %u.\n", cur_wp_id); 547 result.SetStatus(eReturnStatusFailed); 548 return false; 549 } 550 } 551 return result.Succeeded(); 552 } 553 }; 554 555 // CommandObjectWatchpointCommandList 556 557 class CommandObjectWatchpointCommandList : public CommandObjectParsed { 558 public: 559 CommandObjectWatchpointCommandList(CommandInterpreter &interpreter) 560 : CommandObjectParsed(interpreter, "list", 561 "List the script or set of commands to be executed " 562 "when the watchpoint is hit.", 563 nullptr, eCommandRequiresTarget) { 564 CommandArgumentEntry arg; 565 CommandArgumentData wp_id_arg; 566 567 // Define the first (and only) variant of this arg. 568 wp_id_arg.arg_type = eArgTypeWatchpointID; 569 wp_id_arg.arg_repetition = eArgRepeatPlain; 570 571 // There is only one variant this argument could be; put it into the 572 // argument entry. 573 arg.push_back(wp_id_arg); 574 575 // Push the data for the first argument into the m_arguments vector. 576 m_arguments.push_back(arg); 577 } 578 579 ~CommandObjectWatchpointCommandList() override = default; 580 581 protected: 582 bool DoExecute(Args &command, CommandReturnObject &result) override { 583 Target *target = &GetSelectedTarget(); 584 585 const WatchpointList &watchpoints = target->GetWatchpointList(); 586 size_t num_watchpoints = watchpoints.GetSize(); 587 588 if (num_watchpoints == 0) { 589 result.AppendError("No watchpoints exist for which to list commands"); 590 result.SetStatus(eReturnStatusFailed); 591 return false; 592 } 593 594 if (command.GetArgumentCount() == 0) { 595 result.AppendError( 596 "No watchpoint specified for which to list the commands"); 597 result.SetStatus(eReturnStatusFailed); 598 return false; 599 } 600 601 std::vector<uint32_t> valid_wp_ids; 602 if (!CommandObjectMultiwordWatchpoint::VerifyWatchpointIDs(target, command, 603 valid_wp_ids)) { 604 result.AppendError("Invalid watchpoints specification."); 605 result.SetStatus(eReturnStatusFailed); 606 return false; 607 } 608 609 result.SetStatus(eReturnStatusSuccessFinishNoResult); 610 const size_t count = valid_wp_ids.size(); 611 for (size_t i = 0; i < count; ++i) { 612 uint32_t cur_wp_id = valid_wp_ids.at(i); 613 if (cur_wp_id != LLDB_INVALID_WATCH_ID) { 614 Watchpoint *wp = target->GetWatchpointList().FindByID(cur_wp_id).get(); 615 616 if (wp) { 617 const WatchpointOptions *wp_options = wp->GetOptions(); 618 if (wp_options) { 619 // Get the callback baton associated with the current watchpoint. 620 const Baton *baton = wp_options->GetBaton(); 621 if (baton) { 622 result.GetOutputStream().Printf("Watchpoint %u:\n", cur_wp_id); 623 baton->GetDescription(result.GetOutputStream().AsRawOstream(), 624 eDescriptionLevelFull, 625 result.GetOutputStream().GetIndentLevel() + 626 2); 627 } else { 628 result.AppendMessageWithFormat( 629 "Watchpoint %u does not have an associated command.\n", 630 cur_wp_id); 631 } 632 } 633 result.SetStatus(eReturnStatusSuccessFinishResult); 634 } else { 635 result.AppendErrorWithFormat("Invalid watchpoint ID: %u.\n", 636 cur_wp_id); 637 result.SetStatus(eReturnStatusFailed); 638 } 639 } 640 } 641 642 return result.Succeeded(); 643 } 644 }; 645 646 // CommandObjectWatchpointCommand 647 648 CommandObjectWatchpointCommand::CommandObjectWatchpointCommand( 649 CommandInterpreter &interpreter) 650 : CommandObjectMultiword( 651 interpreter, "command", 652 "Commands for adding, removing and examining LLDB commands " 653 "executed when the watchpoint is hit (watchpoint 'commands').", 654 "command <sub-command> [<sub-command-options>] <watchpoint-id>") { 655 CommandObjectSP add_command_object( 656 new CommandObjectWatchpointCommandAdd(interpreter)); 657 CommandObjectSP delete_command_object( 658 new CommandObjectWatchpointCommandDelete(interpreter)); 659 CommandObjectSP list_command_object( 660 new CommandObjectWatchpointCommandList(interpreter)); 661 662 add_command_object->SetCommandName("watchpoint command add"); 663 delete_command_object->SetCommandName("watchpoint command delete"); 664 list_command_object->SetCommandName("watchpoint command list"); 665 666 LoadSubCommand("add", add_command_object); 667 LoadSubCommand("delete", delete_command_object); 668 LoadSubCommand("list", list_command_object); 669 } 670 671 CommandObjectWatchpointCommand::~CommandObjectWatchpointCommand() = default; 672