1 //===-- REPL.cpp ------------------------------------------------*- C++ -*-===//
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 "lldb/Expression/REPL.h"
10 #include "lldb/Core/Debugger.h"
11 #include "lldb/Core/PluginManager.h"
12 #include "lldb/Core/StreamFile.h"
13 #include "lldb/Expression/ExpressionVariable.h"
14 #include "lldb/Expression/UserExpression.h"
15 #include "lldb/Host/HostInfo.h"
16 #include "lldb/Interpreter/CommandInterpreter.h"
17 #include "lldb/Interpreter/CommandReturnObject.h"
18 #include "lldb/Target/Thread.h"
19 #include "lldb/Utility/AnsiTerminal.h"
20
21 #include <memory>
22
23 using namespace lldb_private;
24
REPL(LLVMCastKind kind,Target & target)25 REPL::REPL(LLVMCastKind kind, Target &target) : m_target(target), m_kind(kind) {
26 // Make sure all option values have sane defaults
27 Debugger &debugger = m_target.GetDebugger();
28 auto exe_ctx = debugger.GetCommandInterpreter().GetExecutionContext();
29 m_format_options.OptionParsingStarting(&exe_ctx);
30 m_varobj_options.OptionParsingStarting(&exe_ctx);
31 }
32
33 REPL::~REPL() = default;
34
Create(Status & err,lldb::LanguageType language,Debugger * debugger,Target * target,const char * repl_options)35 lldb::REPLSP REPL::Create(Status &err, lldb::LanguageType language,
36 Debugger *debugger, Target *target,
37 const char *repl_options) {
38 uint32_t idx = 0;
39 lldb::REPLSP ret;
40
41 while (REPLCreateInstance create_instance =
42 PluginManager::GetREPLCreateCallbackAtIndex(idx++)) {
43 ret = (*create_instance)(err, language, debugger, target, repl_options);
44 if (ret) {
45 break;
46 }
47 }
48
49 return ret;
50 }
51
GetSourcePath()52 std::string REPL::GetSourcePath() {
53 ConstString file_basename = GetSourceFileBasename();
54 FileSpec tmpdir_file_spec = HostInfo::GetProcessTempDir();
55 if (tmpdir_file_spec) {
56 tmpdir_file_spec.GetFilename().SetCString(file_basename.AsCString());
57 m_repl_source_path = tmpdir_file_spec.GetPath();
58 } else {
59 tmpdir_file_spec = FileSpec("/tmp");
60 tmpdir_file_spec.AppendPathComponent(file_basename.AsCString());
61 }
62
63 return tmpdir_file_spec.GetPath();
64 }
65
GetIOHandler()66 lldb::IOHandlerSP REPL::GetIOHandler() {
67 if (!m_io_handler_sp) {
68 Debugger &debugger = m_target.GetDebugger();
69 m_io_handler_sp = std::make_shared<IOHandlerEditline>(
70 debugger, IOHandler::Type::REPL,
71 "lldb-repl", // Name of input reader for history
72 llvm::StringRef("> "), // prompt
73 llvm::StringRef(". "), // Continuation prompt
74 true, // Multi-line
75 true, // The REPL prompt is always colored
76 1, // Line number
77 *this, nullptr);
78
79 // Don't exit if CTRL+C is pressed
80 static_cast<IOHandlerEditline *>(m_io_handler_sp.get())
81 ->SetInterruptExits(false);
82
83 if (m_io_handler_sp->GetIsInteractive() &&
84 m_io_handler_sp->GetIsRealTerminal()) {
85 m_indent_str.assign(debugger.GetTabSize(), ' ');
86 m_enable_auto_indent = debugger.GetAutoIndent();
87 } else {
88 m_indent_str.clear();
89 m_enable_auto_indent = false;
90 }
91 }
92 return m_io_handler_sp;
93 }
94
IOHandlerActivated(IOHandler & io_handler,bool interactive)95 void REPL::IOHandlerActivated(IOHandler &io_handler, bool interactive) {
96 lldb::ProcessSP process_sp = m_target.GetProcessSP();
97 if (process_sp && process_sp->IsAlive())
98 return;
99 lldb::StreamFileSP error_sp(io_handler.GetErrorStreamFileSP());
100 error_sp->Printf("REPL requires a running target process.\n");
101 io_handler.SetIsDone(true);
102 }
103
IOHandlerInterrupt(IOHandler & io_handler)104 bool REPL::IOHandlerInterrupt(IOHandler &io_handler) { return false; }
105
IOHandlerInputInterrupted(IOHandler & io_handler,std::string & line)106 void REPL::IOHandlerInputInterrupted(IOHandler &io_handler, std::string &line) {
107 }
108
IOHandlerGetFixIndentationCharacters()109 const char *REPL::IOHandlerGetFixIndentationCharacters() {
110 return (m_enable_auto_indent ? GetAutoIndentCharacters() : nullptr);
111 }
112
IOHandlerGetControlSequence(char ch)113 ConstString REPL::IOHandlerGetControlSequence(char ch) {
114 if (ch == 'd')
115 return ConstString(":quit\n");
116 return ConstString();
117 }
118
IOHandlerGetCommandPrefix()119 const char *REPL::IOHandlerGetCommandPrefix() { return ":"; }
120
IOHandlerGetHelpPrologue()121 const char *REPL::IOHandlerGetHelpPrologue() {
122 return "\nThe REPL (Read-Eval-Print-Loop) acts like an interpreter. "
123 "Valid statements, expressions, and declarations are immediately "
124 "compiled and executed.\n\n"
125 "The complete set of LLDB debugging commands are also available as "
126 "described below. Commands "
127 "must be prefixed with a colon at the REPL prompt (:quit for "
128 "example.) Typing just a colon "
129 "followed by return will switch to the LLDB prompt.\n\n";
130 }
131
IOHandlerIsInputComplete(IOHandler & io_handler,StringList & lines)132 bool REPL::IOHandlerIsInputComplete(IOHandler &io_handler, StringList &lines) {
133 // Check for meta command
134 const size_t num_lines = lines.GetSize();
135 if (num_lines == 1) {
136 const char *first_line = lines.GetStringAtIndex(0);
137 if (first_line[0] == ':')
138 return true; // Meta command is a single line where that starts with ':'
139 }
140
141 // Check if REPL input is done
142 std::string source_string(lines.CopyList());
143 return SourceIsComplete(source_string);
144 }
145
CalculateActualIndentation(const StringList & lines)146 int REPL::CalculateActualIndentation(const StringList &lines) {
147 std::string last_line = lines[lines.GetSize() - 1];
148
149 int actual_indent = 0;
150 for (char &ch : last_line) {
151 if (ch != ' ')
152 break;
153 ++actual_indent;
154 }
155
156 return actual_indent;
157 }
158
IOHandlerFixIndentation(IOHandler & io_handler,const StringList & lines,int cursor_position)159 int REPL::IOHandlerFixIndentation(IOHandler &io_handler,
160 const StringList &lines,
161 int cursor_position) {
162 if (!m_enable_auto_indent)
163 return 0;
164
165 if (!lines.GetSize()) {
166 return 0;
167 }
168
169 int tab_size = io_handler.GetDebugger().GetTabSize();
170
171 lldb::offset_t desired_indent =
172 GetDesiredIndentation(lines, cursor_position, tab_size);
173
174 int actual_indent = REPL::CalculateActualIndentation(lines);
175
176 if (desired_indent == LLDB_INVALID_OFFSET)
177 return 0;
178
179 return (int)desired_indent - actual_indent;
180 }
181
IOHandlerInputComplete(IOHandler & io_handler,std::string & code)182 void REPL::IOHandlerInputComplete(IOHandler &io_handler, std::string &code) {
183 lldb::StreamFileSP output_sp(io_handler.GetOutputStreamFileSP());
184 lldb::StreamFileSP error_sp(io_handler.GetErrorStreamFileSP());
185 bool extra_line = false;
186 bool did_quit = false;
187
188 if (code.empty()) {
189 m_code.AppendString("");
190 static_cast<IOHandlerEditline &>(io_handler)
191 .SetBaseLineNumber(m_code.GetSize() + 1);
192 } else {
193 Debugger &debugger = m_target.GetDebugger();
194 CommandInterpreter &ci = debugger.GetCommandInterpreter();
195 extra_line = ci.GetSpaceReplPrompts();
196
197 ExecutionContext exe_ctx(m_target.GetProcessSP()
198 ->GetThreadList()
199 .GetSelectedThread()
200 ->GetSelectedFrame()
201 .get());
202
203 lldb::ProcessSP process_sp(exe_ctx.GetProcessSP());
204
205 if (code[0] == ':') {
206 // Meta command
207 // Strip the ':'
208 code.erase(0, 1);
209 if (!llvm::StringRef(code).trim().empty()) {
210 // "lldb" was followed by arguments, so just execute the command dump
211 // the results
212
213 // Turn off prompt on quit in case the user types ":quit"
214 const bool saved_prompt_on_quit = ci.GetPromptOnQuit();
215 if (saved_prompt_on_quit)
216 ci.SetPromptOnQuit(false);
217
218 // Execute the command
219 CommandReturnObject result;
220 result.SetImmediateOutputStream(output_sp);
221 result.SetImmediateErrorStream(error_sp);
222 ci.HandleCommand(code.c_str(), eLazyBoolNo, result);
223
224 if (saved_prompt_on_quit)
225 ci.SetPromptOnQuit(true);
226
227 if (result.GetStatus() == lldb::eReturnStatusQuit) {
228 did_quit = true;
229 io_handler.SetIsDone(true);
230 if (debugger.CheckTopIOHandlerTypes(
231 IOHandler::Type::REPL, IOHandler::Type::CommandInterpreter)) {
232 // We typed "quit" or an alias to quit so we need to check if the
233 // command interpreter is above us and tell it that it is done as
234 // well so we don't drop back into the command interpreter if we
235 // have already quit
236 lldb::IOHandlerSP io_handler_sp(ci.GetIOHandler());
237 if (io_handler_sp)
238 io_handler_sp->SetIsDone(true);
239 }
240 }
241 } else {
242 // ":" was followed by no arguments, so push the LLDB command prompt
243 if (debugger.CheckTopIOHandlerTypes(
244 IOHandler::Type::REPL, IOHandler::Type::CommandInterpreter)) {
245 // If the user wants to get back to the command interpreter and the
246 // command interpreter is what launched the REPL, then just let the
247 // REPL exit and fall back to the command interpreter.
248 io_handler.SetIsDone(true);
249 } else {
250 // The REPL wasn't launched the by the command interpreter, it is the
251 // base IOHandler, so we need to get the command interpreter and
252 lldb::IOHandlerSP io_handler_sp(ci.GetIOHandler());
253 if (io_handler_sp) {
254 io_handler_sp->SetIsDone(false);
255 debugger.PushIOHandler(ci.GetIOHandler());
256 }
257 }
258 }
259 } else {
260 // Unwind any expression we might have been running in case our REPL
261 // expression crashed and the user was looking around
262 if (m_dedicated_repl_mode) {
263 Thread *thread = exe_ctx.GetThreadPtr();
264 if (thread && thread->UnwindInnermostExpression().Success()) {
265 thread->SetSelectedFrameByIndex(0, false);
266 exe_ctx.SetFrameSP(thread->GetSelectedFrame());
267 }
268 }
269
270 const bool colorize_err = error_sp->GetFile().GetIsTerminalWithColors();
271
272 EvaluateExpressionOptions expr_options = m_expr_options;
273 expr_options.SetCoerceToId(m_varobj_options.use_objc);
274 expr_options.SetKeepInMemory(true);
275 expr_options.SetUseDynamic(m_varobj_options.use_dynamic);
276 expr_options.SetGenerateDebugInfo(true);
277 expr_options.SetREPLEnabled(true);
278 expr_options.SetColorizeErrors(colorize_err);
279 expr_options.SetPoundLine(m_repl_source_path.c_str(),
280 m_code.GetSize() + 1);
281
282 expr_options.SetLanguage(GetLanguage());
283
284 PersistentExpressionState *persistent_state =
285 m_target.GetPersistentExpressionStateForLanguage(GetLanguage());
286 if (!persistent_state)
287 return;
288
289 const size_t var_count_before = persistent_state->GetSize();
290
291 const char *expr_prefix = nullptr;
292 lldb::ValueObjectSP result_valobj_sp;
293 Status error;
294 lldb::ModuleSP jit_module_sp;
295 lldb::ExpressionResults execution_results =
296 UserExpression::Evaluate(exe_ctx, expr_options, code.c_str(),
297 expr_prefix, result_valobj_sp, error,
298 nullptr, // Fixed Expression
299 &jit_module_sp);
300
301 // CommandInterpreter &ci = debugger.GetCommandInterpreter();
302
303 if (process_sp && process_sp->IsAlive()) {
304 bool add_to_code = true;
305 bool handled = false;
306 if (result_valobj_sp) {
307 lldb::Format format = m_format_options.GetFormat();
308
309 if (result_valobj_sp->GetError().Success()) {
310 handled |= PrintOneVariable(debugger, output_sp, result_valobj_sp);
311 } else if (result_valobj_sp->GetError().GetError() ==
312 UserExpression::kNoResult) {
313 if (format != lldb::eFormatVoid && debugger.GetNotifyVoid()) {
314 error_sp->PutCString("(void)\n");
315 handled = true;
316 }
317 }
318 }
319
320 if (debugger.GetPrintDecls()) {
321 for (size_t vi = var_count_before, ve = persistent_state->GetSize();
322 vi != ve; ++vi) {
323 lldb::ExpressionVariableSP persistent_var_sp =
324 persistent_state->GetVariableAtIndex(vi);
325 lldb::ValueObjectSP valobj_sp = persistent_var_sp->GetValueObject();
326
327 PrintOneVariable(debugger, output_sp, valobj_sp,
328 persistent_var_sp.get());
329 }
330 }
331
332 if (!handled) {
333 bool useColors = error_sp->GetFile().GetIsTerminalWithColors();
334 switch (execution_results) {
335 case lldb::eExpressionSetupError:
336 case lldb::eExpressionParseError:
337 add_to_code = false;
338 LLVM_FALLTHROUGH;
339 case lldb::eExpressionDiscarded:
340 error_sp->Printf("%s\n", error.AsCString());
341 break;
342
343 case lldb::eExpressionCompleted:
344 break;
345 case lldb::eExpressionInterrupted:
346 if (useColors) {
347 error_sp->Printf(ANSI_ESCAPE1(ANSI_FG_COLOR_RED));
348 error_sp->Printf(ANSI_ESCAPE1(ANSI_CTRL_BOLD));
349 }
350 error_sp->Printf("Execution interrupted. ");
351 if (useColors)
352 error_sp->Printf(ANSI_ESCAPE1(ANSI_CTRL_NORMAL));
353 error_sp->Printf("Enter code to recover and continue.\nEnter LLDB "
354 "commands to investigate (type :help for "
355 "assistance.)\n");
356 break;
357
358 case lldb::eExpressionHitBreakpoint:
359 // Breakpoint was hit, drop into LLDB command interpreter
360 if (useColors) {
361 error_sp->Printf(ANSI_ESCAPE1(ANSI_FG_COLOR_RED));
362 error_sp->Printf(ANSI_ESCAPE1(ANSI_CTRL_BOLD));
363 }
364 output_sp->Printf("Execution stopped at breakpoint. ");
365 if (useColors)
366 error_sp->Printf(ANSI_ESCAPE1(ANSI_CTRL_NORMAL));
367 output_sp->Printf("Enter LLDB commands to investigate (type help "
368 "for assistance.)\n");
369 {
370 lldb::IOHandlerSP io_handler_sp(ci.GetIOHandler());
371 if (io_handler_sp) {
372 io_handler_sp->SetIsDone(false);
373 debugger.PushIOHandler(ci.GetIOHandler());
374 }
375 }
376 break;
377
378 case lldb::eExpressionTimedOut:
379 error_sp->Printf("error: timeout\n");
380 if (error.AsCString())
381 error_sp->Printf("error: %s\n", error.AsCString());
382 break;
383 case lldb::eExpressionResultUnavailable:
384 // Shoulnd't happen???
385 error_sp->Printf("error: could not fetch result -- %s\n",
386 error.AsCString());
387 break;
388 case lldb::eExpressionStoppedForDebug:
389 // Shoulnd't happen???
390 error_sp->Printf("error: stopped for debug -- %s\n",
391 error.AsCString());
392 break;
393 }
394 }
395
396 if (add_to_code) {
397 const uint32_t new_default_line = m_code.GetSize() + 1;
398
399 m_code.SplitIntoLines(code);
400
401 // Update our code on disk
402 if (!m_repl_source_path.empty()) {
403 auto file = FileSystem::Instance().Open(
404 FileSpec(m_repl_source_path),
405 File::eOpenOptionWrite | File::eOpenOptionTruncate |
406 File::eOpenOptionCanCreate,
407 lldb::eFilePermissionsFileDefault);
408 if (file) {
409 std::string code(m_code.CopyList());
410 code.append(1, '\n');
411 size_t bytes_written = code.size();
412 file.get()->Write(code.c_str(), bytes_written);
413 file.get()->Close();
414 } else {
415 std::string message = llvm::toString(file.takeError());
416 error_sp->Printf("error: couldn't open %s: %s\n",
417 m_repl_source_path.c_str(), message.c_str());
418 }
419
420 // Now set the default file and line to the REPL source file
421 m_target.GetSourceManager().SetDefaultFileAndLine(
422 FileSpec(m_repl_source_path), new_default_line);
423 }
424 static_cast<IOHandlerEditline &>(io_handler)
425 .SetBaseLineNumber(m_code.GetSize() + 1);
426 }
427 if (extra_line) {
428 output_sp->Printf("\n");
429 }
430 }
431 }
432
433 // Don't complain about the REPL process going away if we are in the
434 // process of quitting.
435 if (!did_quit && (!process_sp || !process_sp->IsAlive())) {
436 error_sp->Printf(
437 "error: REPL process is no longer alive, exiting REPL\n");
438 io_handler.SetIsDone(true);
439 }
440 }
441 }
442
IOHandlerComplete(IOHandler & io_handler,CompletionRequest & request)443 void REPL::IOHandlerComplete(IOHandler &io_handler,
444 CompletionRequest &request) {
445 // Complete an LLDB command if the first character is a colon...
446 if (request.GetRawLine().startswith(":")) {
447 Debugger &debugger = m_target.GetDebugger();
448
449 // auto complete LLDB commands
450 llvm::StringRef new_line = request.GetRawLine().drop_front();
451 CompletionResult sub_result;
452 CompletionRequest sub_request(new_line, request.GetRawCursorPos() - 1,
453 sub_result);
454 debugger.GetCommandInterpreter().HandleCompletion(sub_request);
455 StringList matches, descriptions;
456 sub_result.GetMatches(matches);
457 sub_result.GetDescriptions(descriptions);
458 request.AddCompletions(matches, descriptions);
459 return;
460 }
461
462 // Strip spaces from the line and see if we had only spaces
463 if (request.GetRawLine().trim().empty()) {
464 // Only spaces on this line, so just indent
465 request.AddCompletion(m_indent_str);
466 return;
467 }
468
469 std::string current_code;
470 current_code.append(m_code.CopyList());
471
472 IOHandlerEditline &editline = static_cast<IOHandlerEditline &>(io_handler);
473 const StringList *current_lines = editline.GetCurrentLines();
474 if (current_lines) {
475 const uint32_t current_line_idx = editline.GetCurrentLineIndex();
476
477 if (current_line_idx < current_lines->GetSize()) {
478 for (uint32_t i = 0; i < current_line_idx; ++i) {
479 const char *line_cstr = current_lines->GetStringAtIndex(i);
480 if (line_cstr) {
481 current_code.append("\n");
482 current_code.append(line_cstr);
483 }
484 }
485 }
486 }
487
488 current_code.append("\n");
489 current_code += request.GetRawLine();
490
491 StringList matches;
492 int result = CompleteCode(current_code, matches);
493 if (result == -2) {
494 assert(matches.GetSize() == 1);
495 request.AddCompletion(matches.GetStringAtIndex(0), "",
496 CompletionMode::RewriteLine);
497 } else
498 request.AddCompletions(matches);
499 }
500
QuitCommandOverrideCallback(void * baton,const char ** argv)501 bool QuitCommandOverrideCallback(void *baton, const char **argv) {
502 Target *target = (Target *)baton;
503 lldb::ProcessSP process_sp(target->GetProcessSP());
504 if (process_sp) {
505 process_sp->Destroy(false);
506 process_sp->GetTarget().GetDebugger().ClearIOHandlers();
507 }
508 return false;
509 }
510
RunLoop()511 Status REPL::RunLoop() {
512 Status error;
513
514 error = DoInitialization();
515 m_repl_source_path = GetSourcePath();
516
517 if (!error.Success())
518 return error;
519
520 Debugger &debugger = m_target.GetDebugger();
521
522 lldb::IOHandlerSP io_handler_sp(GetIOHandler());
523
524 FileSpec save_default_file;
525 uint32_t save_default_line = 0;
526
527 if (!m_repl_source_path.empty()) {
528 // Save the current default file and line
529 m_target.GetSourceManager().GetDefaultFileAndLine(save_default_file,
530 save_default_line);
531 }
532
533 debugger.PushIOHandler(io_handler_sp);
534
535 // Check if we are in dedicated REPL mode where LLDB was start with the "--
536 // repl" option from the command line. Currently we know this by checking if
537 // the debugger already has a IOHandler thread.
538 if (!debugger.HasIOHandlerThread()) {
539 // The debugger doesn't have an existing IOHandler thread, so this must be
540 // dedicated REPL mode...
541 m_dedicated_repl_mode = true;
542 debugger.StartIOHandlerThread();
543 llvm::StringRef command_name_str("quit");
544 CommandObject *cmd_obj =
545 debugger.GetCommandInterpreter().GetCommandObjectForCommand(
546 command_name_str);
547 if (cmd_obj) {
548 assert(command_name_str.empty());
549 cmd_obj->SetOverrideCallback(QuitCommandOverrideCallback, &m_target);
550 }
551 }
552
553 // Wait for the REPL command interpreter to get popped
554 io_handler_sp->WaitForPop();
555
556 if (m_dedicated_repl_mode) {
557 // If we were in dedicated REPL mode we would have started the IOHandler
558 // thread, and we should kill our process
559 lldb::ProcessSP process_sp = m_target.GetProcessSP();
560 if (process_sp && process_sp->IsAlive())
561 process_sp->Destroy(false);
562
563 // Wait for the IO handler thread to exit (TODO: don't do this if the IO
564 // handler thread already exists...)
565 debugger.JoinIOHandlerThread();
566 }
567
568 // Restore the default file and line
569 if (save_default_file && save_default_line != 0)
570 m_target.GetSourceManager().SetDefaultFileAndLine(save_default_file,
571 save_default_line);
572 return error;
573 }
574