xref: /llvm-project/lldb/source/Core/IOHandler.cpp (revision 2841cdbfda92b3fb5fbec726f3376b198106d496) 
1 //===-- IOHandler.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 "lldb/Core/IOHandler.h"
10 
11 #if defined(__APPLE__)
12 #include <deque>
13 #endif
14 #include <string>
15 
16 #include "lldb/Core/Debugger.h"
17 #include "lldb/Host/Config.h"
18 #include "lldb/Host/File.h"
19 #include "lldb/Host/StreamFile.h"
20 #include "lldb/Utility/AnsiTerminal.h"
21 #include "lldb/Utility/Predicate.h"
22 #include "lldb/Utility/Status.h"
23 #include "lldb/Utility/StreamString.h"
24 #include "lldb/Utility/StringList.h"
25 #include "lldb/lldb-forward.h"
26 
27 #if LLDB_ENABLE_LIBEDIT
28 #include "lldb/Host/Editline.h"
29 #endif
30 #include "lldb/Interpreter/CommandCompletions.h"
31 #include "lldb/Interpreter/CommandInterpreter.h"
32 #include "llvm/ADT/StringRef.h"
33 
34 #ifdef _WIN32
35 #include "lldb/Host/windows/windows.h"
36 #endif
37 
38 #include <memory>
39 #include <mutex>
40 #include <optional>
41 
42 #include <cassert>
43 #include <cctype>
44 #include <cerrno>
45 #include <clocale>
46 #include <cstdint>
47 #include <cstdio>
48 #include <cstring>
49 #include <type_traits>
50 
51 using namespace lldb;
52 using namespace lldb_private;
53 using llvm::StringRef;
54 
55 IOHandler::IOHandler(Debugger &debugger, IOHandler::Type type)
56     : IOHandler(debugger, type,
57                 FileSP(),       // Adopt STDIN from top input reader
58                 StreamFileSP(), // Adopt STDOUT from top input reader
59                 StreamFileSP(), // Adopt STDERR from top input reader
60                 0               // Flags
61 
62       ) {}
63 
64 IOHandler::IOHandler(Debugger &debugger, IOHandler::Type type,
65                      const lldb::FileSP &input_sp,
66                      const lldb::StreamFileSP &output_sp,
67                      const lldb::StreamFileSP &error_sp, uint32_t flags)
68     : m_debugger(debugger), m_input_sp(input_sp), m_output_sp(output_sp),
69       m_error_sp(error_sp), m_popped(false), m_flags(flags), m_type(type),
70       m_user_data(nullptr), m_done(false), m_active(false) {
71   // If any files are not specified, then adopt them from the top input reader.
72   if (!m_input_sp || !m_output_sp || !m_error_sp)
73     debugger.AdoptTopIOHandlerFilesIfInvalid(m_input_sp, m_output_sp,
74                                              m_error_sp);
75 }
76 
77 IOHandler::~IOHandler() = default;
78 
79 int IOHandler::GetInputFD() {
80   return (m_input_sp ? m_input_sp->GetDescriptor() : -1);
81 }
82 
83 int IOHandler::GetOutputFD() {
84   return (m_output_sp ? m_output_sp->GetFile().GetDescriptor() : -1);
85 }
86 
87 int IOHandler::GetErrorFD() {
88   return (m_error_sp ? m_error_sp->GetFile().GetDescriptor() : -1);
89 }
90 
91 FILE *IOHandler::GetInputFILE() {
92   return (m_input_sp ? m_input_sp->GetStream() : nullptr);
93 }
94 
95 FILE *IOHandler::GetOutputFILE() {
96   return (m_output_sp ? m_output_sp->GetFile().GetStream() : nullptr);
97 }
98 
99 FILE *IOHandler::GetErrorFILE() {
100   return (m_error_sp ? m_error_sp->GetFile().GetStream() : nullptr);
101 }
102 
103 FileSP IOHandler::GetInputFileSP() { return m_input_sp; }
104 
105 StreamFileSP IOHandler::GetOutputStreamFileSP() { return m_output_sp; }
106 
107 StreamFileSP IOHandler::GetErrorStreamFileSP() { return m_error_sp; }
108 
109 bool IOHandler::GetIsInteractive() {
110   return GetInputFileSP() ? GetInputFileSP()->GetIsInteractive() : false;
111 }
112 
113 bool IOHandler::GetIsRealTerminal() {
114   return GetInputFileSP() ? GetInputFileSP()->GetIsRealTerminal() : false;
115 }
116 
117 void IOHandler::SetPopped(bool b) { m_popped.SetValue(b, eBroadcastOnChange); }
118 
119 void IOHandler::WaitForPop() { m_popped.WaitForValueEqualTo(true); }
120 
121 void IOHandler::PrintAsync(const char *s, size_t len, bool is_stdout) {
122   std::lock_guard<std::recursive_mutex> guard(m_output_mutex);
123   lldb::StreamFileSP stream = is_stdout ? m_output_sp : m_error_sp;
124   stream->Write(s, len);
125   stream->Flush();
126 }
127 
128 bool IOHandlerStack::PrintAsync(const char *s, size_t len, bool is_stdout) {
129   std::lock_guard<std::recursive_mutex> guard(m_mutex);
130   if (!m_top)
131     return false;
132   m_top->PrintAsync(s, len, is_stdout);
133   return true;
134 }
135 
136 IOHandlerConfirm::IOHandlerConfirm(Debugger &debugger, llvm::StringRef prompt,
137                                    bool default_response)
138     : IOHandlerEditline(
139           debugger, IOHandler::Type::Confirm,
140           nullptr, // nullptr editline_name means no history loaded/saved
141           llvm::StringRef(), // No prompt
142           llvm::StringRef(), // No continuation prompt
143           false,             // Multi-line
144           false, // Don't colorize the prompt (i.e. the confirm message.)
145           0, *this),
146       m_default_response(default_response), m_user_response(default_response) {
147   StreamString prompt_stream;
148   prompt_stream.PutCString(prompt);
149   if (m_default_response)
150     prompt_stream.Printf(": [Y/n] ");
151   else
152     prompt_stream.Printf(": [y/N] ");
153 
154   SetPrompt(prompt_stream.GetString());
155 }
156 
157 IOHandlerConfirm::~IOHandlerConfirm() = default;
158 
159 void IOHandlerConfirm::IOHandlerComplete(IOHandler &io_handler,
160                                          CompletionRequest &request) {
161   if (request.GetRawCursorPos() != 0)
162     return;
163   request.AddCompletion(m_default_response ? "y" : "n");
164 }
165 
166 void IOHandlerConfirm::IOHandlerInputComplete(IOHandler &io_handler,
167                                               std::string &line) {
168   if (line.empty()) {
169     // User just hit enter, set the response to the default
170     m_user_response = m_default_response;
171     io_handler.SetIsDone(true);
172     return;
173   }
174 
175   if (line.size() == 1) {
176     switch (line[0]) {
177     case 'y':
178     case 'Y':
179       m_user_response = true;
180       io_handler.SetIsDone(true);
181       return;
182     case 'n':
183     case 'N':
184       m_user_response = false;
185       io_handler.SetIsDone(true);
186       return;
187     default:
188       break;
189     }
190   }
191 
192   if (line == "yes" || line == "YES" || line == "Yes") {
193     m_user_response = true;
194     io_handler.SetIsDone(true);
195   } else if (line == "no" || line == "NO" || line == "No") {
196     m_user_response = false;
197     io_handler.SetIsDone(true);
198   }
199 }
200 
201 std::optional<std::string>
202 IOHandlerDelegate::IOHandlerSuggestion(IOHandler &io_handler,
203                                        llvm::StringRef line) {
204   return io_handler.GetDebugger()
205       .GetCommandInterpreter()
206       .GetAutoSuggestionForCommand(line);
207 }
208 
209 void IOHandlerDelegate::IOHandlerComplete(IOHandler &io_handler,
210                                           CompletionRequest &request) {
211   switch (m_completion) {
212   case Completion::None:
213     break;
214   case Completion::LLDBCommand:
215     io_handler.GetDebugger().GetCommandInterpreter().HandleCompletion(request);
216     break;
217   case Completion::Expression:
218     lldb_private::CommandCompletions::InvokeCommonCompletionCallbacks(
219         io_handler.GetDebugger().GetCommandInterpreter(),
220         lldb::eVariablePathCompletion, request, nullptr);
221     break;
222   }
223 }
224 
225 IOHandlerEditline::IOHandlerEditline(
226     Debugger &debugger, IOHandler::Type type,
227     const char *editline_name, // Used for saving history files
228     llvm::StringRef prompt, llvm::StringRef continuation_prompt,
229     bool multi_line, bool color, uint32_t line_number_start,
230     IOHandlerDelegate &delegate)
231     : IOHandlerEditline(debugger, type,
232                         FileSP(),       // Inherit input from top input reader
233                         StreamFileSP(), // Inherit output from top input reader
234                         StreamFileSP(), // Inherit error from top input reader
235                         0,              // Flags
236                         editline_name,  // Used for saving history files
237                         prompt, continuation_prompt, multi_line, color,
238                         line_number_start, delegate) {}
239 
240 IOHandlerEditline::IOHandlerEditline(
241     Debugger &debugger, IOHandler::Type type, const lldb::FileSP &input_sp,
242     const lldb::StreamFileSP &output_sp, const lldb::StreamFileSP &error_sp,
243     uint32_t flags,
244     const char *editline_name, // Used for saving history files
245     llvm::StringRef prompt, llvm::StringRef continuation_prompt,
246     bool multi_line, bool color, uint32_t line_number_start,
247     IOHandlerDelegate &delegate)
248     : IOHandler(debugger, type, input_sp, output_sp, error_sp, flags),
249 #if LLDB_ENABLE_LIBEDIT
250       m_editline_up(),
251 #endif
252       m_delegate(delegate), m_prompt(), m_continuation_prompt(),
253       m_current_lines_ptr(nullptr), m_base_line_number(line_number_start),
254       m_curr_line_idx(UINT32_MAX), m_multi_line(multi_line), m_color(color),
255       m_interrupt_exits(true) {
256   SetPrompt(prompt);
257 
258 #if LLDB_ENABLE_LIBEDIT
259   bool use_editline = false;
260 
261   use_editline = GetInputFILE() && GetOutputFILE() && GetErrorFILE() &&
262                  m_input_sp && m_input_sp->GetIsRealTerminal();
263 
264   if (use_editline) {
265     m_editline_up = std::make_unique<Editline>(editline_name, GetInputFILE(),
266                                                GetOutputFILE(), GetErrorFILE(),
267                                                m_color, GetOutputMutex());
268     m_editline_up->SetIsInputCompleteCallback(
269         [this](Editline *editline, StringList &lines) {
270           return this->IsInputCompleteCallback(editline, lines);
271         });
272 
273     m_editline_up->SetAutoCompleteCallback([this](CompletionRequest &request) {
274       this->AutoCompleteCallback(request);
275     });
276 
277     if (debugger.GetUseAutosuggestion()) {
278       m_editline_up->SetSuggestionCallback([this](llvm::StringRef line) {
279         return this->SuggestionCallback(line);
280       });
281       m_editline_up->SetSuggestionAnsiPrefix(ansi::FormatAnsiTerminalCodes(
282           debugger.GetAutosuggestionAnsiPrefix()));
283       m_editline_up->SetSuggestionAnsiSuffix(ansi::FormatAnsiTerminalCodes(
284           debugger.GetAutosuggestionAnsiSuffix()));
285     }
286     // See if the delegate supports fixing indentation
287     const char *indent_chars = delegate.IOHandlerGetFixIndentationCharacters();
288     if (indent_chars) {
289       // The delegate does support indentation, hook it up so when any
290       // indentation character is typed, the delegate gets a chance to fix it
291       FixIndentationCallbackType f = [this](Editline *editline,
292                                             const StringList &lines,
293                                             int cursor_position) {
294         return this->FixIndentationCallback(editline, lines, cursor_position);
295       };
296       m_editline_up->SetFixIndentationCallback(std::move(f), indent_chars);
297     }
298   }
299 #endif
300   SetBaseLineNumber(m_base_line_number);
301   SetPrompt(prompt);
302   SetContinuationPrompt(continuation_prompt);
303 }
304 
305 IOHandlerEditline::~IOHandlerEditline() {
306 #if LLDB_ENABLE_LIBEDIT
307   m_editline_up.reset();
308 #endif
309 }
310 
311 void IOHandlerEditline::Activate() {
312   IOHandler::Activate();
313   m_delegate.IOHandlerActivated(*this, GetIsInteractive());
314 }
315 
316 void IOHandlerEditline::Deactivate() {
317   IOHandler::Deactivate();
318   m_delegate.IOHandlerDeactivated(*this);
319 }
320 
321 void IOHandlerEditline::TerminalSizeChanged() {
322 #if LLDB_ENABLE_LIBEDIT
323   if (m_editline_up)
324     m_editline_up->TerminalSizeChanged();
325 #endif
326 }
327 
328 // Split out a line from the buffer, if there is a full one to get.
329 static std::optional<std::string> SplitLine(std::string &line_buffer) {
330   size_t pos = line_buffer.find('\n');
331   if (pos == std::string::npos)
332     return std::nullopt;
333   std::string line =
334       std::string(StringRef(line_buffer.c_str(), pos).rtrim("\n\r"));
335   line_buffer = line_buffer.substr(pos + 1);
336   return line;
337 }
338 
339 // If the final line of the file ends without a end-of-line, return
340 // it as a line anyway.
341 static std::optional<std::string> SplitLineEOF(std::string &line_buffer) {
342   if (llvm::all_of(line_buffer, llvm::isSpace))
343     return std::nullopt;
344   std::string line = std::move(line_buffer);
345   line_buffer.clear();
346   return line;
347 }
348 
349 bool IOHandlerEditline::GetLine(std::string &line, bool &interrupted) {
350 #if LLDB_ENABLE_LIBEDIT
351   if (m_editline_up) {
352     return m_editline_up->GetLine(line, interrupted);
353   }
354 #endif
355 
356   line.clear();
357 
358   if (GetIsInteractive()) {
359     const char *prompt = nullptr;
360 
361     if (m_multi_line && m_curr_line_idx > 0)
362       prompt = GetContinuationPrompt();
363 
364     if (prompt == nullptr)
365       prompt = GetPrompt();
366 
367     if (prompt && prompt[0]) {
368       if (m_output_sp) {
369         m_output_sp->Printf("%s", prompt);
370         m_output_sp->Flush();
371       }
372     }
373   }
374 
375   std::optional<std::string> got_line = SplitLine(m_line_buffer);
376 
377   if (!got_line && !m_input_sp) {
378     // No more input file, we are done...
379     SetIsDone(true);
380     return false;
381   }
382 
383   FILE *in = GetInputFILE();
384   char buffer[256];
385 
386   if (!got_line && !in && m_input_sp) {
387     // there is no FILE*, fall back on just reading bytes from the stream.
388     while (!got_line) {
389       size_t bytes_read = sizeof(buffer);
390       Status error = m_input_sp->Read((void *)buffer, bytes_read);
391       if (error.Success() && !bytes_read) {
392         got_line = SplitLineEOF(m_line_buffer);
393         break;
394       }
395       if (error.Fail())
396         break;
397       m_line_buffer += StringRef(buffer, bytes_read);
398       got_line = SplitLine(m_line_buffer);
399     }
400   }
401 
402   if (!got_line && in) {
403     while (!got_line) {
404       char *r = fgets(buffer, sizeof(buffer), in);
405 #ifdef _WIN32
406       // ReadFile on Windows is supposed to set ERROR_OPERATION_ABORTED
407       // according to the docs on MSDN. However, this has evidently been a
408       // known bug since Windows 8. Therefore, we can't detect if a signal
409       // interrupted in the fgets. So pressing ctrl-c causes the repl to end
410       // and the process to exit. A temporary workaround is just to attempt to
411       // fgets twice until this bug is fixed.
412       if (r == nullptr)
413         r = fgets(buffer, sizeof(buffer), in);
414       // this is the equivalent of EINTR for Windows
415       if (r == nullptr && GetLastError() == ERROR_OPERATION_ABORTED)
416         continue;
417 #endif
418       if (r == nullptr) {
419         if (ferror(in) && errno == EINTR)
420           continue;
421         if (feof(in))
422           got_line = SplitLineEOF(m_line_buffer);
423         break;
424       }
425       m_line_buffer += buffer;
426       got_line = SplitLine(m_line_buffer);
427     }
428   }
429 
430   if (got_line) {
431     line = *got_line;
432   }
433 
434   return (bool)got_line;
435 }
436 
437 #if LLDB_ENABLE_LIBEDIT
438 bool IOHandlerEditline::IsInputCompleteCallback(Editline *editline,
439                                                 StringList &lines) {
440   return m_delegate.IOHandlerIsInputComplete(*this, lines);
441 }
442 
443 int IOHandlerEditline::FixIndentationCallback(Editline *editline,
444                                               const StringList &lines,
445                                               int cursor_position) {
446   return m_delegate.IOHandlerFixIndentation(*this, lines, cursor_position);
447 }
448 
449 std::optional<std::string>
450 IOHandlerEditline::SuggestionCallback(llvm::StringRef line) {
451   return m_delegate.IOHandlerSuggestion(*this, line);
452 }
453 
454 void IOHandlerEditline::AutoCompleteCallback(CompletionRequest &request) {
455   m_delegate.IOHandlerComplete(*this, request);
456 }
457 #endif
458 
459 const char *IOHandlerEditline::GetPrompt() {
460 #if LLDB_ENABLE_LIBEDIT
461   if (m_editline_up) {
462     return m_editline_up->GetPrompt();
463   } else {
464 #endif
465     if (m_prompt.empty())
466       return nullptr;
467 #if LLDB_ENABLE_LIBEDIT
468   }
469 #endif
470   return m_prompt.c_str();
471 }
472 
473 bool IOHandlerEditline::SetPrompt(llvm::StringRef prompt) {
474   m_prompt = std::string(prompt);
475 
476 #if LLDB_ENABLE_LIBEDIT
477   if (m_editline_up) {
478     m_editline_up->SetPrompt(m_prompt.empty() ? nullptr : m_prompt.c_str());
479     m_editline_up->SetPromptAnsiPrefix(
480         ansi::FormatAnsiTerminalCodes(m_debugger.GetPromptAnsiPrefix()));
481     m_editline_up->SetPromptAnsiSuffix(
482         ansi::FormatAnsiTerminalCodes(m_debugger.GetPromptAnsiSuffix()));
483   }
484 #endif
485   return true;
486 }
487 
488 const char *IOHandlerEditline::GetContinuationPrompt() {
489   return (m_continuation_prompt.empty() ? nullptr
490                                         : m_continuation_prompt.c_str());
491 }
492 
493 void IOHandlerEditline::SetContinuationPrompt(llvm::StringRef prompt) {
494   m_continuation_prompt = std::string(prompt);
495 
496 #if LLDB_ENABLE_LIBEDIT
497   if (m_editline_up)
498     m_editline_up->SetContinuationPrompt(m_continuation_prompt.empty()
499                                              ? nullptr
500                                              : m_continuation_prompt.c_str());
501 #endif
502 }
503 
504 void IOHandlerEditline::SetBaseLineNumber(uint32_t line) {
505   m_base_line_number = line;
506 }
507 
508 uint32_t IOHandlerEditline::GetCurrentLineIndex() const {
509 #if LLDB_ENABLE_LIBEDIT
510   if (m_editline_up)
511     return m_editline_up->GetCurrentLine();
512 #endif
513   return m_curr_line_idx;
514 }
515 
516 StringList IOHandlerEditline::GetCurrentLines() const {
517 #if LLDB_ENABLE_LIBEDIT
518   if (m_editline_up)
519     return m_editline_up->GetInputAsStringList();
520 #endif
521   // When libedit is not used, the current lines can be gotten from
522   // `m_current_lines_ptr`, which is updated whenever a new line is processed.
523   // This doesn't happen when libedit is used, in which case
524   // `m_current_lines_ptr` is only updated when the full input is terminated.
525 
526   if (m_current_lines_ptr)
527     return *m_current_lines_ptr;
528   return StringList();
529 }
530 
531 bool IOHandlerEditline::GetLines(StringList &lines, bool &interrupted) {
532   m_current_lines_ptr = &lines;
533 
534   bool success = false;
535 #if LLDB_ENABLE_LIBEDIT
536   if (m_editline_up) {
537     return m_editline_up->GetLines(m_base_line_number, lines, interrupted);
538   } else {
539 #endif
540     bool done = false;
541     Status error;
542 
543     while (!done) {
544       // Show line numbers if we are asked to
545       std::string line;
546       if (m_base_line_number > 0 && GetIsInteractive()) {
547         if (m_output_sp) {
548           m_output_sp->Printf("%u%s",
549                               m_base_line_number + (uint32_t)lines.GetSize(),
550                               GetPrompt() == nullptr ? " " : "");
551         }
552       }
553 
554       m_curr_line_idx = lines.GetSize();
555 
556       bool interrupted = false;
557       if (GetLine(line, interrupted) && !interrupted) {
558         lines.AppendString(line);
559         done = m_delegate.IOHandlerIsInputComplete(*this, lines);
560       } else {
561         done = true;
562       }
563     }
564     success = lines.GetSize() > 0;
565 #if LLDB_ENABLE_LIBEDIT
566   }
567 #endif
568   return success;
569 }
570 
571 // Each IOHandler gets to run until it is done. It should read data from the
572 // "in" and place output into "out" and "err and return when done.
573 void IOHandlerEditline::Run() {
574   std::string line;
575   while (IsActive()) {
576     bool interrupted = false;
577     if (m_multi_line) {
578       StringList lines;
579       if (GetLines(lines, interrupted)) {
580         if (interrupted) {
581           m_done = m_interrupt_exits;
582           m_delegate.IOHandlerInputInterrupted(*this, line);
583 
584         } else {
585           line = lines.CopyList();
586           m_delegate.IOHandlerInputComplete(*this, line);
587         }
588       } else {
589         m_done = true;
590       }
591     } else {
592       if (GetLine(line, interrupted)) {
593         if (interrupted)
594           m_delegate.IOHandlerInputInterrupted(*this, line);
595         else
596           m_delegate.IOHandlerInputComplete(*this, line);
597       } else {
598         m_done = true;
599       }
600     }
601   }
602 }
603 
604 void IOHandlerEditline::Cancel() {
605 #if LLDB_ENABLE_LIBEDIT
606   if (m_editline_up)
607     m_editline_up->Cancel();
608 #endif
609 }
610 
611 bool IOHandlerEditline::Interrupt() {
612   // Let the delgate handle it first
613   if (m_delegate.IOHandlerInterrupt(*this))
614     return true;
615 
616 #if LLDB_ENABLE_LIBEDIT
617   if (m_editline_up)
618     return m_editline_up->Interrupt();
619 #endif
620   return false;
621 }
622 
623 void IOHandlerEditline::GotEOF() {
624 #if LLDB_ENABLE_LIBEDIT
625   if (m_editline_up)
626     m_editline_up->Interrupt();
627 #endif
628 }
629 
630 void IOHandlerEditline::PrintAsync(const char *s, size_t len, bool is_stdout) {
631 #if LLDB_ENABLE_LIBEDIT
632   if (m_editline_up) {
633     std::lock_guard<std::recursive_mutex> guard(m_output_mutex);
634     lldb::StreamFileSP stream = is_stdout ? m_output_sp : m_error_sp;
635     m_editline_up->PrintAsync(stream.get(), s, len);
636   } else
637 #endif
638   {
639 #ifdef _WIN32
640     const char *prompt = GetPrompt();
641     if (prompt) {
642       // Back up over previous prompt using Windows API
643       CONSOLE_SCREEN_BUFFER_INFO screen_buffer_info;
644       HANDLE console_handle = GetStdHandle(STD_OUTPUT_HANDLE);
645       GetConsoleScreenBufferInfo(console_handle, &screen_buffer_info);
646       COORD coord = screen_buffer_info.dwCursorPosition;
647       coord.X -= strlen(prompt);
648       if (coord.X < 0)
649         coord.X = 0;
650       SetConsoleCursorPosition(console_handle, coord);
651     }
652 #endif
653     IOHandler::PrintAsync(s, len, is_stdout);
654 #ifdef _WIN32
655     if (prompt)
656       IOHandler::PrintAsync(prompt, strlen(prompt), is_stdout);
657 #endif
658   }
659 }
660