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:
CommandObjectWatchpointCommandAdd(CommandInterpreter & interpreter)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 CommandArgumentEntry arg;
166 CommandArgumentData wp_id_arg;
167
168 // Define the first (and only) variant of this arg.
169 wp_id_arg.arg_type = eArgTypeWatchpointID;
170 wp_id_arg.arg_repetition = eArgRepeatPlain;
171
172 // There is only one variant this argument could be; put it into the
173 // argument entry.
174 arg.push_back(wp_id_arg);
175
176 // Push the data for the first argument into the m_arguments vector.
177 m_arguments.push_back(arg);
178 }
179
180 ~CommandObjectWatchpointCommandAdd() override = default;
181
GetOptions()182 Options *GetOptions() override { return &m_options; }
183
IOHandlerActivated(IOHandler & io_handler,bool interactive)184 void IOHandlerActivated(IOHandler &io_handler, bool interactive) override {
185 StreamFileSP output_sp(io_handler.GetOutputStreamFileSP());
186 if (output_sp && interactive) {
187 output_sp->PutCString(
188 "Enter your debugger command(s). Type 'DONE' to end.\n");
189 output_sp->Flush();
190 }
191 }
192
IOHandlerInputComplete(IOHandler & io_handler,std::string & line)193 void IOHandlerInputComplete(IOHandler &io_handler,
194 std::string &line) override {
195 io_handler.SetIsDone(true);
196
197 // The WatchpointOptions object is owned by the watchpoint or watchpoint
198 // location
199 WatchpointOptions *wp_options =
200 (WatchpointOptions *)io_handler.GetUserData();
201 if (wp_options) {
202 std::unique_ptr<WatchpointOptions::CommandData> data_up(
203 new WatchpointOptions::CommandData());
204 if (data_up) {
205 data_up->user_source.SplitIntoLines(line);
206 auto baton_sp = std::make_shared<WatchpointOptions::CommandBaton>(
207 std::move(data_up));
208 wp_options->SetCallback(WatchpointOptionsCallbackFunction, baton_sp);
209 }
210 }
211 }
212
CollectDataForWatchpointCommandCallback(WatchpointOptions * wp_options,CommandReturnObject & result)213 void CollectDataForWatchpointCommandCallback(WatchpointOptions *wp_options,
214 CommandReturnObject &result) {
215 m_interpreter.GetLLDBCommandsFromIOHandler(
216 "> ", // Prompt
217 *this, // IOHandlerDelegate
218 wp_options); // Baton for the "io_handler" that will be passed back into
219 // our IOHandlerDelegate functions
220 }
221
222 /// Set a one-liner as the callback for the watchpoint.
SetWatchpointCommandCallback(WatchpointOptions * wp_options,const char * oneliner)223 void SetWatchpointCommandCallback(WatchpointOptions *wp_options,
224 const char *oneliner) {
225 std::unique_ptr<WatchpointOptions::CommandData> data_up(
226 new WatchpointOptions::CommandData());
227
228 // It's necessary to set both user_source and script_source to the
229 // oneliner. The former is used to generate callback description (as in
230 // watchpoint command list) while the latter is used for Python to
231 // interpret during the actual callback.
232 data_up->user_source.AppendString(oneliner);
233 data_up->script_source.assign(oneliner);
234 data_up->stop_on_error = m_options.m_stop_on_error;
235
236 auto baton_sp =
237 std::make_shared<WatchpointOptions::CommandBaton>(std::move(data_up));
238 wp_options->SetCallback(WatchpointOptionsCallbackFunction, baton_sp);
239 }
240
241 static bool
WatchpointOptionsCallbackFunction(void * baton,StoppointCallbackContext * context,lldb::user_id_t watch_id)242 WatchpointOptionsCallbackFunction(void *baton,
243 StoppointCallbackContext *context,
244 lldb::user_id_t watch_id) {
245 bool ret_value = true;
246 if (baton == nullptr)
247 return true;
248
249 WatchpointOptions::CommandData *data =
250 (WatchpointOptions::CommandData *)baton;
251 StringList &commands = data->user_source;
252
253 if (commands.GetSize() > 0) {
254 ExecutionContext exe_ctx(context->exe_ctx_ref);
255 Target *target = exe_ctx.GetTargetPtr();
256 if (target) {
257 Debugger &debugger = target->GetDebugger();
258 CommandReturnObject result(debugger.GetUseColor());
259
260 // Rig up the results secondary output stream to the debugger's, so the
261 // output will come out synchronously if the debugger is set up that
262 // way.
263 StreamSP output_stream(debugger.GetAsyncOutputStream());
264 StreamSP error_stream(debugger.GetAsyncErrorStream());
265 result.SetImmediateOutputStream(output_stream);
266 result.SetImmediateErrorStream(error_stream);
267
268 CommandInterpreterRunOptions options;
269 options.SetStopOnContinue(true);
270 options.SetStopOnError(data->stop_on_error);
271 options.SetEchoCommands(false);
272 options.SetPrintResults(true);
273 options.SetPrintErrors(true);
274 options.SetAddToHistory(false);
275
276 debugger.GetCommandInterpreter().HandleCommands(commands, exe_ctx,
277 options, result);
278 result.GetImmediateOutputStream()->Flush();
279 result.GetImmediateErrorStream()->Flush();
280 }
281 }
282 return ret_value;
283 }
284
285 class CommandOptions : public Options {
286 public:
287 CommandOptions() = default;
288
289 ~CommandOptions() override = default;
290
SetOptionValue(uint32_t option_idx,llvm::StringRef option_arg,ExecutionContext * execution_context)291 Status SetOptionValue(uint32_t option_idx, llvm::StringRef option_arg,
292 ExecutionContext *execution_context) override {
293 Status error;
294 const int short_option = m_getopt_table[option_idx].val;
295
296 switch (short_option) {
297 case 'o':
298 m_use_one_liner = true;
299 m_one_liner = std::string(option_arg);
300 break;
301
302 case 's':
303 m_script_language = (lldb::ScriptLanguage)OptionArgParser::ToOptionEnum(
304 option_arg, GetDefinitions()[option_idx].enum_values,
305 eScriptLanguageNone, error);
306
307 switch (m_script_language) {
308 case eScriptLanguagePython:
309 case eScriptLanguageLua:
310 m_use_script_language = true;
311 break;
312 case eScriptLanguageNone:
313 case eScriptLanguageUnknown:
314 m_use_script_language = false;
315 break;
316 }
317 break;
318
319 case 'e': {
320 bool success = false;
321 m_stop_on_error =
322 OptionArgParser::ToBoolean(option_arg, false, &success);
323 if (!success)
324 error.SetErrorStringWithFormat(
325 "invalid value for stop-on-error: \"%s\"",
326 option_arg.str().c_str());
327 } break;
328
329 case 'F':
330 m_use_one_liner = false;
331 m_function_name.assign(std::string(option_arg));
332 break;
333
334 default:
335 llvm_unreachable("Unimplemented option");
336 }
337 return error;
338 }
339
OptionParsingStarting(ExecutionContext * execution_context)340 void OptionParsingStarting(ExecutionContext *execution_context) override {
341 m_use_commands = true;
342 m_use_script_language = false;
343 m_script_language = eScriptLanguageNone;
344
345 m_use_one_liner = false;
346 m_stop_on_error = true;
347 m_one_liner.clear();
348 m_function_name.clear();
349 }
350
GetDefinitions()351 llvm::ArrayRef<OptionDefinition> GetDefinitions() override {
352 return llvm::ArrayRef(g_watchpoint_command_add_options);
353 }
354
355 // Instance variables to hold the values for command options.
356
357 bool m_use_commands = false;
358 bool m_use_script_language = false;
359 lldb::ScriptLanguage m_script_language = eScriptLanguageNone;
360
361 // Instance variables to hold the values for one_liner options.
362 bool m_use_one_liner = false;
363 std::string m_one_liner;
364 bool m_stop_on_error;
365 std::string m_function_name;
366 };
367
368 protected:
DoExecute(Args & command,CommandReturnObject & result)369 void DoExecute(Args &command, CommandReturnObject &result) override {
370 Target *target = &GetSelectedTarget();
371
372 const WatchpointList &watchpoints = target->GetWatchpointList();
373 size_t num_watchpoints = watchpoints.GetSize();
374
375 if (num_watchpoints == 0) {
376 result.AppendError("No watchpoints exist to have commands added");
377 return;
378 }
379
380 if (!m_options.m_function_name.empty()) {
381 if (!m_options.m_use_script_language) {
382 m_options.m_script_language = GetDebugger().GetScriptLanguage();
383 m_options.m_use_script_language = true;
384 }
385 }
386
387 std::vector<uint32_t> valid_wp_ids;
388 if (!CommandObjectMultiwordWatchpoint::VerifyWatchpointIDs(target, command,
389 valid_wp_ids)) {
390 result.AppendError("Invalid watchpoints specification.");
391 return;
392 }
393
394 result.SetStatus(eReturnStatusSuccessFinishNoResult);
395 const size_t count = valid_wp_ids.size();
396 for (size_t i = 0; i < count; ++i) {
397 uint32_t cur_wp_id = valid_wp_ids.at(i);
398 if (cur_wp_id != LLDB_INVALID_WATCH_ID) {
399 Watchpoint *wp = target->GetWatchpointList().FindByID(cur_wp_id).get();
400 // Sanity check wp first.
401 if (wp == nullptr)
402 continue;
403
404 WatchpointOptions *wp_options = wp->GetOptions();
405 // Skip this watchpoint if wp_options is not good.
406 if (wp_options == nullptr)
407 continue;
408
409 // If we are using script language, get the script interpreter in order
410 // to set or collect command callback. Otherwise, call the methods
411 // associated with this object.
412 if (m_options.m_use_script_language) {
413 ScriptInterpreter *script_interp = GetDebugger().GetScriptInterpreter(
414 /*can_create=*/true, m_options.m_script_language);
415 // Special handling for one-liner specified inline.
416 if (m_options.m_use_one_liner) {
417 script_interp->SetWatchpointCommandCallback(
418 wp_options, m_options.m_one_liner.c_str(),
419 /*is_callback=*/false);
420 }
421 // Special handling for using a Python function by name instead of
422 // extending the watchpoint callback data structures, we just
423 // automatize what the user would do manually: make their watchpoint
424 // command be a function call
425 else if (!m_options.m_function_name.empty()) {
426 std::string function_signature = m_options.m_function_name;
427 function_signature += "(frame, wp, internal_dict)";
428 script_interp->SetWatchpointCommandCallback(
429 wp_options, function_signature.c_str(), /*is_callback=*/true);
430 } else {
431 script_interp->CollectDataForWatchpointCommandCallback(wp_options,
432 result);
433 }
434 } else {
435 // Special handling for one-liner specified inline.
436 if (m_options.m_use_one_liner)
437 SetWatchpointCommandCallback(wp_options,
438 m_options.m_one_liner.c_str());
439 else
440 CollectDataForWatchpointCommandCallback(wp_options, result);
441 }
442 }
443 }
444 }
445
446 private:
447 CommandOptions m_options;
448 };
449
450 // CommandObjectWatchpointCommandDelete
451
452 class CommandObjectWatchpointCommandDelete : public CommandObjectParsed {
453 public:
CommandObjectWatchpointCommandDelete(CommandInterpreter & interpreter)454 CommandObjectWatchpointCommandDelete(CommandInterpreter &interpreter)
455 : CommandObjectParsed(interpreter, "delete",
456 "Delete the set of commands from a watchpoint.",
457 nullptr, eCommandRequiresTarget) {
458 CommandArgumentEntry arg;
459 CommandArgumentData wp_id_arg;
460
461 // Define the first (and only) variant of this arg.
462 wp_id_arg.arg_type = eArgTypeWatchpointID;
463 wp_id_arg.arg_repetition = eArgRepeatPlain;
464
465 // There is only one variant this argument could be; put it into the
466 // argument entry.
467 arg.push_back(wp_id_arg);
468
469 // Push the data for the first argument into the m_arguments vector.
470 m_arguments.push_back(arg);
471 }
472
473 ~CommandObjectWatchpointCommandDelete() override = default;
474
475 protected:
DoExecute(Args & command,CommandReturnObject & result)476 void DoExecute(Args &command, CommandReturnObject &result) override {
477 Target *target = &GetSelectedTarget();
478
479 const WatchpointList &watchpoints = target->GetWatchpointList();
480 size_t num_watchpoints = watchpoints.GetSize();
481
482 if (num_watchpoints == 0) {
483 result.AppendError("No watchpoints exist to have commands deleted");
484 return;
485 }
486
487 if (command.GetArgumentCount() == 0) {
488 result.AppendError(
489 "No watchpoint specified from which to delete the commands");
490 return;
491 }
492
493 std::vector<uint32_t> valid_wp_ids;
494 if (!CommandObjectMultiwordWatchpoint::VerifyWatchpointIDs(target, command,
495 valid_wp_ids)) {
496 result.AppendError("Invalid watchpoints specification.");
497 return;
498 }
499
500 result.SetStatus(eReturnStatusSuccessFinishNoResult);
501 const size_t count = valid_wp_ids.size();
502 for (size_t i = 0; i < count; ++i) {
503 uint32_t cur_wp_id = valid_wp_ids.at(i);
504 if (cur_wp_id != LLDB_INVALID_WATCH_ID) {
505 Watchpoint *wp = target->GetWatchpointList().FindByID(cur_wp_id).get();
506 if (wp)
507 wp->ClearCallback();
508 } else {
509 result.AppendErrorWithFormat("Invalid watchpoint ID: %u.\n", cur_wp_id);
510 return;
511 }
512 }
513 }
514 };
515
516 // CommandObjectWatchpointCommandList
517
518 class CommandObjectWatchpointCommandList : public CommandObjectParsed {
519 public:
CommandObjectWatchpointCommandList(CommandInterpreter & interpreter)520 CommandObjectWatchpointCommandList(CommandInterpreter &interpreter)
521 : CommandObjectParsed(interpreter, "list",
522 "List the script or set of commands to be executed "
523 "when the watchpoint is hit.",
524 nullptr, eCommandRequiresTarget) {
525 CommandArgumentEntry arg;
526 CommandArgumentData wp_id_arg;
527
528 // Define the first (and only) variant of this arg.
529 wp_id_arg.arg_type = eArgTypeWatchpointID;
530 wp_id_arg.arg_repetition = eArgRepeatPlain;
531
532 // There is only one variant this argument could be; put it into the
533 // argument entry.
534 arg.push_back(wp_id_arg);
535
536 // Push the data for the first argument into the m_arguments vector.
537 m_arguments.push_back(arg);
538 }
539
540 ~CommandObjectWatchpointCommandList() override = default;
541
542 protected:
DoExecute(Args & command,CommandReturnObject & result)543 void DoExecute(Args &command, CommandReturnObject &result) override {
544 Target *target = &GetSelectedTarget();
545
546 const WatchpointList &watchpoints = target->GetWatchpointList();
547 size_t num_watchpoints = watchpoints.GetSize();
548
549 if (num_watchpoints == 0) {
550 result.AppendError("No watchpoints exist for which to list commands");
551 return;
552 }
553
554 if (command.GetArgumentCount() == 0) {
555 result.AppendError(
556 "No watchpoint specified for which to list the commands");
557 return;
558 }
559
560 std::vector<uint32_t> valid_wp_ids;
561 if (!CommandObjectMultiwordWatchpoint::VerifyWatchpointIDs(target, command,
562 valid_wp_ids)) {
563 result.AppendError("Invalid watchpoints specification.");
564 return;
565 }
566
567 result.SetStatus(eReturnStatusSuccessFinishNoResult);
568 const size_t count = valid_wp_ids.size();
569 for (size_t i = 0; i < count; ++i) {
570 uint32_t cur_wp_id = valid_wp_ids.at(i);
571 if (cur_wp_id != LLDB_INVALID_WATCH_ID) {
572 Watchpoint *wp = target->GetWatchpointList().FindByID(cur_wp_id).get();
573
574 if (wp) {
575 const WatchpointOptions *wp_options = wp->GetOptions();
576 if (wp_options) {
577 // Get the callback baton associated with the current watchpoint.
578 const Baton *baton = wp_options->GetBaton();
579 if (baton) {
580 result.GetOutputStream().Printf("Watchpoint %u:\n", cur_wp_id);
581 baton->GetDescription(result.GetOutputStream().AsRawOstream(),
582 eDescriptionLevelFull,
583 result.GetOutputStream().GetIndentLevel() +
584 2);
585 } else {
586 result.AppendMessageWithFormat(
587 "Watchpoint %u does not have an associated command.\n",
588 cur_wp_id);
589 }
590 }
591 result.SetStatus(eReturnStatusSuccessFinishResult);
592 } else {
593 result.AppendErrorWithFormat("Invalid watchpoint ID: %u.\n",
594 cur_wp_id);
595 }
596 }
597 }
598 }
599 };
600
601 // CommandObjectWatchpointCommand
602
CommandObjectWatchpointCommand(CommandInterpreter & interpreter)603 CommandObjectWatchpointCommand::CommandObjectWatchpointCommand(
604 CommandInterpreter &interpreter)
605 : CommandObjectMultiword(
606 interpreter, "command",
607 "Commands for adding, removing and examining LLDB commands "
608 "executed when the watchpoint is hit (watchpoint 'commands').",
609 "command <sub-command> [<sub-command-options>] <watchpoint-id>") {
610 CommandObjectSP add_command_object(
611 new CommandObjectWatchpointCommandAdd(interpreter));
612 CommandObjectSP delete_command_object(
613 new CommandObjectWatchpointCommandDelete(interpreter));
614 CommandObjectSP list_command_object(
615 new CommandObjectWatchpointCommandList(interpreter));
616
617 add_command_object->SetCommandName("watchpoint command add");
618 delete_command_object->SetCommandName("watchpoint command delete");
619 list_command_object->SetCommandName("watchpoint command list");
620
621 LoadSubCommand("add", add_command_object);
622 LoadSubCommand("delete", delete_command_object);
623 LoadSubCommand("list", list_command_object);
624 }
625
626 CommandObjectWatchpointCommand::~CommandObjectWatchpointCommand() = default;
627