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
23using namespace lldb;
24using namespace lldb_private;
25
26#define LLDB_OPTIONS_watchpoint_command_add
27#include "CommandOptions.inc"
28
29class CommandObjectWatchpointCommandAdd : public CommandObjectParsed,
30 public IOHandlerDelegateMultiline {
31public:
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"(
43General information about entering watchpoint commands
44------------------------------------------------------
45
46)"
47 "This command will prompt for commands to be executed when the specified \
48watchpoint is hit. Each command is typed on its own line following the '> ' \
49prompt until 'DONE' is entered."
50 R"(
51
52)"
53 "Syntactic errors may not be detected when initially entered, and many \
54malformed commands can silently fail when executed. If your watchpoint commands \
55do 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 \
60prompt. There is no limit to the number of commands supplied, but do NOT enter \
61more than one command per line."
62 R"(
63
64Special information about PYTHON watchpoint commands
65----------------------------------------------------
66
67)"
68 "You may enter either one or more lines of Python, including function \
69definitions or calls to functions that will have been imported by the time \
70the code executes. Single line watchpoint commands will be interpreted 'as is' \
71when the watchpoint is hit. Multiple lines of Python will be wrapped in a \
72generated function, and a call to the function will be attached to the watchpoint."
73 R"(
74
75This 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 \
83to supply the function name prepended by the module name:"
84 R"(
85
86 --python-function myutils.watchpoint_callback
87
88The function itself must have the following prototype:
89
90def 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 \
95described above. Note that the global variable 'lldb.frame' will NOT be updated when \
96this function is called, so be sure to use the 'frame' argument. The 'frame' argument \
97can get you to the thread via frame.GetThread(), the thread can get you to the \
98process via thread.GetProcess(), and the process can get you back to the target \
99via process.GetTarget()."
100 R"(
101
102)"
103 "Important Note: As Python code gets collected into functions, access to global \
104variables requires explicit scoping using the 'global' keyword. Be sure to use correct \
105Python syntax, including indentation, when entering Python watchpoint commands."
106 R"(
107
108Example Python one-line watchpoint command:
109
110(lldb) watchpoint command add -s python 1
111Enter your Python command(s). Type 'DONE' to end.
112> print "Hit this watchpoint!"
113> DONE
114
115As 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
119Launching '.../a.out' (x86_64)
120(lldb) Fri Sep 10 12:17:45 2010
121Process 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
131Example multiple line Python watchpoint command, using function definition:
132
133(lldb) watchpoint command add -s python 1
134Enter 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
142Example multiple line Python watchpoint command, using 'loose' Python:
143
144(lldb) watchpoint command add -s p 1
145Enter 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 \
154initialized:"
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 \
163are no syntax errors may indicate that a function was declared but never called.");
164
165 AddSimpleArgumentList(arg_type: 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 cstr: "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(callback: WatchpointOptionsCallbackFunction, baton_sp: baton_sp);
197 }
198 }
199 }
200
201 void CollectDataForWatchpointCommandCallback(WatchpointOptions *wp_options,
202 CommandReturnObject &result) {
203 m_interpreter.GetLLDBCommandsFromIOHandler(
204 prompt: "> ", // Prompt
205 delegate&: *this, // IOHandlerDelegate
206 baton: 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(callback: WatchpointOptionsCallbackFunction, baton_sp: 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, context: 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(s: option_arg, fail_value: false, success_ptr: &success);
311 if (!success)
312 error.SetErrorStringWithFormat(
313 "invalid value for stop-on-error: \"%s\"",
314 option_arg.str().c_str());
315 } break;
316
317 case 'F':
318 m_use_one_liner = false;
319 m_function_name.assign(str: std::string(option_arg));
320 break;
321
322 default:
323 llvm_unreachable("Unimplemented option");
324 }
325 return error;
326 }
327
328 void OptionParsingStarting(ExecutionContext *execution_context) override {
329 m_use_commands = true;
330 m_use_script_language = false;
331 m_script_language = eScriptLanguageNone;
332
333 m_use_one_liner = false;
334 m_stop_on_error = true;
335 m_one_liner.clear();
336 m_function_name.clear();
337 }
338
339 llvm::ArrayRef<OptionDefinition> GetDefinitions() override {
340 return llvm::ArrayRef(g_watchpoint_command_add_options);
341 }
342
343 // Instance variables to hold the values for command options.
344
345 bool m_use_commands = false;
346 bool m_use_script_language = false;
347 lldb::ScriptLanguage m_script_language = eScriptLanguageNone;
348
349 // Instance variables to hold the values for one_liner options.
350 bool m_use_one_liner = false;
351 std::string m_one_liner;
352 bool m_stop_on_error;
353 std::string m_function_name;
354 };
355
356protected:
357 void DoExecute(Args &command, CommandReturnObject &result) override {
358 Target *target = &GetSelectedTarget();
359
360 const WatchpointList &watchpoints = target->GetWatchpointList();
361 size_t num_watchpoints = watchpoints.GetSize();
362
363 if (num_watchpoints == 0) {
364 result.AppendError(in_string: "No watchpoints exist to have commands added");
365 return;
366 }
367
368 if (!m_options.m_function_name.empty()) {
369 if (!m_options.m_use_script_language) {
370 m_options.m_script_language = GetDebugger().GetScriptLanguage();
371 m_options.m_use_script_language = true;
372 }
373 }
374
375 std::vector<uint32_t> valid_wp_ids;
376 if (!CommandObjectMultiwordWatchpoint::VerifyWatchpointIDs(target, args&: command,
377 wp_ids&: valid_wp_ids)) {
378 result.AppendError(in_string: "Invalid watchpoints specification.");
379 return;
380 }
381
382 result.SetStatus(eReturnStatusSuccessFinishNoResult);
383 const size_t count = valid_wp_ids.size();
384 for (size_t i = 0; i < count; ++i) {
385 uint32_t cur_wp_id = valid_wp_ids.at(i);
386 if (cur_wp_id != LLDB_INVALID_WATCH_ID) {
387 Watchpoint *wp = target->GetWatchpointList().FindByID(watchID: cur_wp_id).get();
388 // Sanity check wp first.
389 if (wp == nullptr)
390 continue;
391
392 WatchpointOptions *wp_options = wp->GetOptions();
393 // Skip this watchpoint if wp_options is not good.
394 if (wp_options == nullptr)
395 continue;
396
397 // If we are using script language, get the script interpreter in order
398 // to set or collect command callback. Otherwise, call the methods
399 // associated with this object.
400 if (m_options.m_use_script_language) {
401 ScriptInterpreter *script_interp = GetDebugger().GetScriptInterpreter(
402 /*can_create=*/true, m_options.m_script_language);
403 // Special handling for one-liner specified inline.
404 if (m_options.m_use_one_liner) {
405 script_interp->SetWatchpointCommandCallback(
406 wp_options, user_input: m_options.m_one_liner.c_str(),
407 /*is_callback=*/false);
408 }
409 // Special handling for using a Python function by name instead of
410 // extending the watchpoint callback data structures, we just
411 // automatize what the user would do manually: make their watchpoint
412 // command be a function call
413 else if (!m_options.m_function_name.empty()) {
414 std::string function_signature = m_options.m_function_name;
415 function_signature += "(frame, wp, internal_dict)";
416 script_interp->SetWatchpointCommandCallback(
417 wp_options, user_input: function_signature.c_str(), /*is_callback=*/true);
418 } else {
419 script_interp->CollectDataForWatchpointCommandCallback(wp_options,
420 result);
421 }
422 } else {
423 // Special handling for one-liner specified inline.
424 if (m_options.m_use_one_liner)
425 SetWatchpointCommandCallback(wp_options,
426 oneliner: m_options.m_one_liner.c_str());
427 else
428 CollectDataForWatchpointCommandCallback(wp_options, result);
429 }
430 }
431 }
432 }
433
434private:
435 CommandOptions m_options;
436};
437
438// CommandObjectWatchpointCommandDelete
439
440class CommandObjectWatchpointCommandDelete : public CommandObjectParsed {
441public:
442 CommandObjectWatchpointCommandDelete(CommandInterpreter &interpreter)
443 : CommandObjectParsed(interpreter, "delete",
444 "Delete the set of commands from a watchpoint.",
445 nullptr, eCommandRequiresTarget) {
446 AddSimpleArgumentList(arg_type: eArgTypeWatchpointID);
447 }
448
449 ~CommandObjectWatchpointCommandDelete() override = default;
450
451protected:
452 void DoExecute(Args &command, CommandReturnObject &result) override {
453 Target *target = &GetSelectedTarget();
454
455 const WatchpointList &watchpoints = target->GetWatchpointList();
456 size_t num_watchpoints = watchpoints.GetSize();
457
458 if (num_watchpoints == 0) {
459 result.AppendError(in_string: "No watchpoints exist to have commands deleted");
460 return;
461 }
462
463 if (command.GetArgumentCount() == 0) {
464 result.AppendError(
465 in_string: "No watchpoint specified from which to delete the commands");
466 return;
467 }
468
469 std::vector<uint32_t> valid_wp_ids;
470 if (!CommandObjectMultiwordWatchpoint::VerifyWatchpointIDs(target, args&: command,
471 wp_ids&: valid_wp_ids)) {
472 result.AppendError(in_string: "Invalid watchpoints specification.");
473 return;
474 }
475
476 result.SetStatus(eReturnStatusSuccessFinishNoResult);
477 const size_t count = valid_wp_ids.size();
478 for (size_t i = 0; i < count; ++i) {
479 uint32_t cur_wp_id = valid_wp_ids.at(n: i);
480 if (cur_wp_id != LLDB_INVALID_WATCH_ID) {
481 Watchpoint *wp = target->GetWatchpointList().FindByID(watchID: cur_wp_id).get();
482 if (wp)
483 wp->ClearCallback();
484 } else {
485 result.AppendErrorWithFormat(format: "Invalid watchpoint ID: %u.\n", cur_wp_id);
486 return;
487 }
488 }
489 }
490};
491
492// CommandObjectWatchpointCommandList
493
494class CommandObjectWatchpointCommandList : public CommandObjectParsed {
495public:
496 CommandObjectWatchpointCommandList(CommandInterpreter &interpreter)
497 : CommandObjectParsed(interpreter, "list",
498 "List the script or set of commands to be executed "
499 "when the watchpoint is hit.",
500 nullptr, eCommandRequiresTarget) {
501 AddSimpleArgumentList(arg_type: eArgTypeWatchpointID);
502 }
503
504 ~CommandObjectWatchpointCommandList() override = default;
505
506protected:
507 void DoExecute(Args &command, CommandReturnObject &result) override {
508 Target *target = &GetSelectedTarget();
509
510 const WatchpointList &watchpoints = target->GetWatchpointList();
511 size_t num_watchpoints = watchpoints.GetSize();
512
513 if (num_watchpoints == 0) {
514 result.AppendError(in_string: "No watchpoints exist for which to list commands");
515 return;
516 }
517
518 if (command.GetArgumentCount() == 0) {
519 result.AppendError(
520 in_string: "No watchpoint specified for which to list the commands");
521 return;
522 }
523
524 std::vector<uint32_t> valid_wp_ids;
525 if (!CommandObjectMultiwordWatchpoint::VerifyWatchpointIDs(target, args&: command,
526 wp_ids&: valid_wp_ids)) {
527 result.AppendError(in_string: "Invalid watchpoints specification.");
528 return;
529 }
530
531 result.SetStatus(eReturnStatusSuccessFinishNoResult);
532 const size_t count = valid_wp_ids.size();
533 for (size_t i = 0; i < count; ++i) {
534 uint32_t cur_wp_id = valid_wp_ids.at(n: i);
535 if (cur_wp_id != LLDB_INVALID_WATCH_ID) {
536 Watchpoint *wp = target->GetWatchpointList().FindByID(watchID: cur_wp_id).get();
537
538 if (wp) {
539 const WatchpointOptions *wp_options = wp->GetOptions();
540 if (wp_options) {
541 // Get the callback baton associated with the current watchpoint.
542 const Baton *baton = wp_options->GetBaton();
543 if (baton) {
544 result.GetOutputStream().Printf(format: "Watchpoint %u:\n", cur_wp_id);
545 baton->GetDescription(s&: result.GetOutputStream().AsRawOstream(),
546 level: eDescriptionLevelFull,
547 indentation: result.GetOutputStream().GetIndentLevel() +
548 2);
549 } else {
550 result.AppendMessageWithFormat(
551 format: "Watchpoint %u does not have an associated command.\n",
552 cur_wp_id);
553 }
554 }
555 result.SetStatus(eReturnStatusSuccessFinishResult);
556 } else {
557 result.AppendErrorWithFormat(format: "Invalid watchpoint ID: %u.\n",
558 cur_wp_id);
559 }
560 }
561 }
562 }
563};
564
565// CommandObjectWatchpointCommand
566
567CommandObjectWatchpointCommand::CommandObjectWatchpointCommand(
568 CommandInterpreter &interpreter)
569 : CommandObjectMultiword(
570 interpreter, "command",
571 "Commands for adding, removing and examining LLDB commands "
572 "executed when the watchpoint is hit (watchpoint 'commands').",
573 "command <sub-command> [<sub-command-options>] <watchpoint-id>") {
574 CommandObjectSP add_command_object(
575 new CommandObjectWatchpointCommandAdd(interpreter));
576 CommandObjectSP delete_command_object(
577 new CommandObjectWatchpointCommandDelete(interpreter));
578 CommandObjectSP list_command_object(
579 new CommandObjectWatchpointCommandList(interpreter));
580
581 add_command_object->SetCommandName("watchpoint command add");
582 delete_command_object->SetCommandName("watchpoint command delete");
583 list_command_object->SetCommandName("watchpoint command list");
584
585 LoadSubCommand(cmd_name: "add", command_obj: add_command_object);
586 LoadSubCommand(cmd_name: "delete", command_obj: delete_command_object);
587 LoadSubCommand(cmd_name: "list", command_obj: list_command_object);
588}
589
590CommandObjectWatchpointCommand::~CommandObjectWatchpointCommand() = default;
591

source code of lldb/source/Commands/CommandObjectWatchpointCommand.cpp