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