1 /* Top level stuff for GDB, the GNU debugger. 2 3 Copyright (C) 1999-2002, 2004-2005, 2007-2012 Free Software 4 Foundation, Inc. 5 6 Written by Elena Zannoni <ezannoni@cygnus.com> of Cygnus Solutions. 7 8 This file is part of GDB. 9 10 This program is free software; you can redistribute it and/or modify 11 it under the terms of the GNU General Public License as published by 12 the Free Software Foundation; either version 3 of the License, or 13 (at your option) any later version. 14 15 This program is distributed in the hope that it will be useful, 16 but WITHOUT ANY WARRANTY; without even the implied warranty of 17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 18 GNU General Public License for more details. 19 20 You should have received a copy of the GNU General Public License 21 along with this program. If not, see <http://www.gnu.org/licenses/>. */ 22 23 #include "defs.h" 24 #include "top.h" 25 #include "inferior.h" 26 #include "target.h" 27 #include "terminal.h" /* for job_control */ 28 #include "event-loop.h" 29 #include "event-top.h" 30 #include "interps.h" 31 #include <signal.h> 32 #include "exceptions.h" 33 #include "cli/cli-script.h" /* for reset_command_nest_depth */ 34 #include "main.h" 35 #include "gdbthread.h" 36 #include "observer.h" 37 #include "continuations.h" 38 #include "gdbcmd.h" /* for dont_repeat() */ 39 40 /* readline include files. */ 41 #include "readline/readline.h" 42 #include "readline/history.h" 43 44 /* readline defines this. */ 45 #undef savestring 46 47 static void rl_callback_read_char_wrapper (gdb_client_data client_data); 48 static void command_line_handler (char *rl); 49 static void change_line_handler (void); 50 static void command_handler (char *command); 51 static char *top_level_prompt (void); 52 53 /* Signal handlers. */ 54 #ifdef SIGQUIT 55 static void handle_sigquit (int sig); 56 #endif 57 #ifdef SIGHUP 58 static void handle_sighup (int sig); 59 #endif 60 static void handle_sigfpe (int sig); 61 #if defined(SIGWINCH) && defined(SIGWINCH_HANDLER) 62 static void handle_sigwinch (int sig); 63 #endif 64 65 /* Functions to be invoked by the event loop in response to 66 signals. */ 67 #if defined (SIGQUIT) || defined (SIGHUP) 68 static void async_do_nothing (gdb_client_data); 69 #endif 70 #ifdef SIGHUP 71 static void async_disconnect (gdb_client_data); 72 #endif 73 static void async_float_handler (gdb_client_data); 74 #ifdef STOP_SIGNAL 75 static void async_stop_sig (gdb_client_data); 76 #endif 77 78 /* Readline offers an alternate interface, via callback 79 functions. These are all included in the file callback.c in the 80 readline distribution. This file provides (mainly) a function, which 81 the event loop uses as callback (i.e. event handler) whenever an event 82 is detected on the standard input file descriptor. 83 readline_callback_read_char is called (by the GDB event loop) whenever 84 there is a new character ready on the input stream. This function 85 incrementally builds a buffer internal to readline where it 86 accumulates the line read up to the point of invocation. In the 87 special case in which the character read is newline, the function 88 invokes a GDB supplied callback routine, which does the processing of 89 a full command line. This latter routine is the asynchronous analog 90 of the old command_line_input in gdb. Instead of invoking (and waiting 91 for) readline to read the command line and pass it back to 92 command_loop for processing, the new command_line_handler function has 93 the command line already available as its parameter. INPUT_HANDLER is 94 to be set to the function that readline will invoke when a complete 95 line of input is ready. CALL_READLINE is to be set to the function 96 that readline offers as callback to the event_loop. */ 97 98 void (*input_handler) (char *); 99 void (*call_readline) (gdb_client_data); 100 101 /* Important variables for the event loop. */ 102 103 /* This is used to determine if GDB is using the readline library or 104 its own simplified form of readline. It is used by the asynchronous 105 form of the set editing command. 106 ezannoni: as of 1999-04-29 I expect that this 107 variable will not be used after gdb is changed to use the event 108 loop as default engine, and event-top.c is merged into top.c. */ 109 int async_command_editing_p; 110 111 /* This is the annotation suffix that will be used when the 112 annotation_level is 2. */ 113 char *async_annotation_suffix; 114 115 /* This is used to display the notification of the completion of an 116 asynchronous execution command. */ 117 int exec_done_display_p = 0; 118 119 /* This is the file descriptor for the input stream that GDB uses to 120 read commands from. */ 121 int input_fd; 122 123 /* Signal handling variables. */ 124 /* Each of these is a pointer to a function that the event loop will 125 invoke if the corresponding signal has received. The real signal 126 handlers mark these functions as ready to be executed and the event 127 loop, in a later iteration, calls them. See the function 128 invoke_async_signal_handler. */ 129 void *sigint_token; 130 #ifdef SIGHUP 131 void *sighup_token; 132 #endif 133 #ifdef SIGQUIT 134 void *sigquit_token; 135 #endif 136 void *sigfpe_token; 137 #if defined(SIGWINCH) && defined(SIGWINCH_HANDLER) 138 void *sigwinch_token; 139 #endif 140 #ifdef STOP_SIGNAL 141 void *sigtstp_token; 142 #endif 143 144 /* Structure to save a partially entered command. This is used when 145 the user types '\' at the end of a command line. This is necessary 146 because each line of input is handled by a different call to 147 command_line_handler, and normally there is no state retained 148 between different calls. */ 149 static int more_to_come = 0; 150 151 struct readline_input_state 152 { 153 char *linebuffer; 154 char *linebuffer_ptr; 155 } 156 readline_input_state; 157 158 /* This hook is called by rl_callback_read_char_wrapper after each 159 character is processed. */ 160 void (*after_char_processing_hook) (void); 161 162 163 /* Wrapper function for calling into the readline library. The event 164 loop expects the callback function to have a paramter, while 165 readline expects none. */ 166 static void 167 rl_callback_read_char_wrapper (gdb_client_data client_data) 168 { 169 rl_callback_read_char (); 170 if (after_char_processing_hook) 171 (*after_char_processing_hook) (); 172 } 173 174 /* Initialize all the necessary variables, start the event loop, 175 register readline, and stdin, start the loop. */ 176 void 177 cli_command_loop (void) 178 { 179 display_gdb_prompt (0); 180 181 /* Now it's time to start the event loop. */ 182 start_event_loop (); 183 } 184 185 /* Change the function to be invoked every time there is a character 186 ready on stdin. This is used when the user sets the editing off, 187 therefore bypassing readline, and letting gdb handle the input 188 itself, via gdb_readline2. Also it is used in the opposite case in 189 which the user sets editing on again, by restoring readline 190 handling of the input. */ 191 static void 192 change_line_handler (void) 193 { 194 /* NOTE: this operates on input_fd, not instream. If we are reading 195 commands from a file, instream will point to the file. However in 196 async mode, we always read commands from a file with editing 197 off. This means that the 'set editing on/off' will have effect 198 only on the interactive session. */ 199 200 if (async_command_editing_p) 201 { 202 /* Turn on editing by using readline. */ 203 call_readline = rl_callback_read_char_wrapper; 204 input_handler = command_line_handler; 205 } 206 else 207 { 208 /* Turn off editing by using gdb_readline2. */ 209 rl_callback_handler_remove (); 210 call_readline = gdb_readline2; 211 212 /* Set up the command handler as well, in case we are called as 213 first thing from .gdbinit. */ 214 input_handler = command_line_handler; 215 } 216 } 217 218 /* Displays the prompt. If the argument NEW_PROMPT is NULL, the 219 prompt that is displayed is the current top level prompt. 220 Otherwise, it displays whatever NEW_PROMPT is as a local/secondary 221 prompt. 222 223 This is used after each gdb command has completed, and in the 224 following cases: 225 226 1. When the user enters a command line which is ended by '\' 227 indicating that the command will continue on the next line. In 228 that case the prompt that is displayed is the empty string. 229 230 2. When the user is entering 'commands' for a breakpoint, or 231 actions for a tracepoint. In this case the prompt will be '>' 232 233 3. On prompting for pagination. */ 234 235 void 236 display_gdb_prompt (char *new_prompt) 237 { 238 char *actual_gdb_prompt = NULL; 239 struct cleanup *old_chain; 240 241 /* Reset the nesting depth used when trace-commands is set. */ 242 reset_command_nest_depth (); 243 244 /* Each interpreter has its own rules on displaying the command 245 prompt. */ 246 if (!current_interp_display_prompt_p ()) 247 return; 248 249 old_chain = make_cleanup (free_current_contents, &actual_gdb_prompt); 250 251 /* Do not call the python hook on an explicit prompt change as 252 passed to this function, as this forms a secondary/local prompt, 253 IE, displayed but not set. */ 254 if (! new_prompt) 255 { 256 if (sync_execution) 257 { 258 /* This is to trick readline into not trying to display the 259 prompt. Even though we display the prompt using this 260 function, readline still tries to do its own display if 261 we don't call rl_callback_handler_install and 262 rl_callback_handler_remove (which readline detects 263 because a global variable is not set). If readline did 264 that, it could mess up gdb signal handlers for SIGINT. 265 Readline assumes that between calls to rl_set_signals and 266 rl_clear_signals gdb doesn't do anything with the signal 267 handlers. Well, that's not the case, because when the 268 target executes we change the SIGINT signal handler. If 269 we allowed readline to display the prompt, the signal 270 handler change would happen exactly between the calls to 271 the above two functions. Calling 272 rl_callback_handler_remove(), does the job. */ 273 274 rl_callback_handler_remove (); 275 return; 276 } 277 else 278 { 279 /* Display the top level prompt. */ 280 actual_gdb_prompt = top_level_prompt (); 281 } 282 } 283 else 284 actual_gdb_prompt = xstrdup (new_prompt); 285 286 if (async_command_editing_p) 287 { 288 rl_callback_handler_remove (); 289 rl_callback_handler_install (actual_gdb_prompt, input_handler); 290 } 291 /* new_prompt at this point can be the top of the stack or the one 292 passed in. It can't be NULL. */ 293 else 294 { 295 /* Don't use a _filtered function here. It causes the assumed 296 character position to be off, since the newline we read from 297 the user is not accounted for. */ 298 fputs_unfiltered (actual_gdb_prompt, gdb_stdout); 299 gdb_flush (gdb_stdout); 300 } 301 302 do_cleanups (old_chain); 303 } 304 305 /* Return the top level prompt, as specified by "set prompt", possibly 306 overriden by the python gdb.prompt_hook hook, and then composed 307 with the prompt prefix and suffix (annotations). The caller is 308 responsible for freeing the returned string. */ 309 310 static char * 311 top_level_prompt (void) 312 { 313 char *prefix; 314 char *prompt = NULL; 315 char *suffix; 316 char *composed_prompt; 317 size_t prompt_length; 318 319 /* Give observers a chance of changing the prompt. E.g., the python 320 `gdb.prompt_hook' is installed as an observer. */ 321 observer_notify_before_prompt (get_prompt ()); 322 323 prompt = xstrdup (get_prompt ()); 324 325 if (annotation_level >= 2) 326 { 327 /* Prefix needs to have new line at end. */ 328 prefix = (char *) alloca (strlen (async_annotation_suffix) + 10); 329 strcpy (prefix, "\n\032\032pre-"); 330 strcat (prefix, async_annotation_suffix); 331 strcat (prefix, "\n"); 332 333 /* Suffix needs to have a new line at end and \032 \032 at 334 beginning. */ 335 suffix = (char *) alloca (strlen (async_annotation_suffix) + 6); 336 strcpy (suffix, "\n\032\032"); 337 strcat (suffix, async_annotation_suffix); 338 strcat (suffix, "\n"); 339 } 340 else 341 { 342 prefix = ""; 343 suffix = ""; 344 } 345 346 prompt_length = strlen (prefix) + strlen (prompt) + strlen (suffix); 347 composed_prompt = xmalloc (prompt_length + 1); 348 349 strcpy (composed_prompt, prefix); 350 strcat (composed_prompt, prompt); 351 strcat (composed_prompt, suffix); 352 353 xfree (prompt); 354 355 return composed_prompt; 356 } 357 358 /* When there is an event ready on the stdin file desriptor, instead 359 of calling readline directly throught the callback function, or 360 instead of calling gdb_readline2, give gdb a chance to detect 361 errors and do something. */ 362 void 363 stdin_event_handler (int error, gdb_client_data client_data) 364 { 365 if (error) 366 { 367 printf_unfiltered (_("error detected on stdin\n")); 368 delete_file_handler (input_fd); 369 discard_all_continuations (); 370 discard_all_intermediate_continuations (); 371 /* If stdin died, we may as well kill gdb. */ 372 quit_command ((char *) 0, stdin == instream); 373 } 374 else 375 (*call_readline) (client_data); 376 } 377 378 /* Re-enable stdin after the end of an execution command in 379 synchronous mode, or after an error from the target, and we aborted 380 the exec operation. */ 381 382 void 383 async_enable_stdin (void) 384 { 385 if (sync_execution) 386 { 387 /* See NOTE in async_disable_stdin(). */ 388 /* FIXME: cagney/1999-09-27: Call this before clearing 389 sync_execution. Current target_terminal_ours() implementations 390 check for sync_execution before switching the terminal. */ 391 target_terminal_ours (); 392 sync_execution = 0; 393 } 394 } 395 396 /* Disable reads from stdin (the console) marking the command as 397 synchronous. */ 398 399 void 400 async_disable_stdin (void) 401 { 402 sync_execution = 1; 403 } 404 405 406 /* Handles a gdb command. This function is called by 407 command_line_handler, which has processed one or more input lines 408 into COMMAND. */ 409 /* NOTE: 1999-04-30 This is the asynchronous version of the command_loop 410 function. The command_loop function will be obsolete when we 411 switch to use the event loop at every execution of gdb. */ 412 static void 413 command_handler (char *command) 414 { 415 int stdin_is_tty = ISATTY (stdin); 416 struct cleanup *stat_chain; 417 418 quit_flag = 0; 419 if (instream == stdin && stdin_is_tty) 420 reinitialize_more_filter (); 421 422 /* If readline returned a NULL command, it means that the connection 423 with the terminal is gone. This happens at the end of a 424 testsuite run, after Expect has hung up but GDB is still alive. 425 In such a case, we just quit gdb killing the inferior program 426 too. */ 427 if (command == 0) 428 { 429 printf_unfiltered ("quit\n"); 430 execute_command ("quit", stdin == instream); 431 } 432 433 stat_chain = make_command_stats_cleanup (1); 434 435 execute_command (command, instream == stdin); 436 437 /* Do any commands attached to breakpoint we stopped at. */ 438 bpstat_do_actions (); 439 440 do_cleanups (stat_chain); 441 } 442 443 /* Handle a complete line of input. This is called by the callback 444 mechanism within the readline library. Deal with incomplete 445 commands as well, by saving the partial input in a global 446 buffer. */ 447 448 /* NOTE: 1999-04-30 This is the asynchronous version of the 449 command_line_input function; command_line_input will become 450 obsolete once we use the event loop as the default mechanism in 451 GDB. */ 452 static void 453 command_line_handler (char *rl) 454 { 455 static char *linebuffer = 0; 456 static unsigned linelength = 0; 457 char *p; 458 char *p1; 459 char *nline; 460 char got_eof = 0; 461 462 int repeat = (instream == stdin); 463 464 if (annotation_level > 1 && instream == stdin) 465 { 466 printf_unfiltered (("\n\032\032post-")); 467 puts_unfiltered (async_annotation_suffix); 468 printf_unfiltered (("\n")); 469 } 470 471 if (linebuffer == 0) 472 { 473 linelength = 80; 474 linebuffer = (char *) xmalloc (linelength); 475 } 476 477 p = linebuffer; 478 479 if (more_to_come) 480 { 481 strcpy (linebuffer, readline_input_state.linebuffer); 482 p = readline_input_state.linebuffer_ptr; 483 xfree (readline_input_state.linebuffer); 484 more_to_come = 0; 485 } 486 487 #ifdef STOP_SIGNAL 488 if (job_control) 489 signal (STOP_SIGNAL, handle_stop_sig); 490 #endif 491 492 /* Make sure that all output has been output. Some machines may let 493 you get away with leaving out some of the gdb_flush, but not 494 all. */ 495 wrap_here (""); 496 gdb_flush (gdb_stdout); 497 gdb_flush (gdb_stderr); 498 499 if (source_file_name != NULL) 500 ++source_line_number; 501 502 /* If we are in this case, then command_handler will call quit 503 and exit from gdb. */ 504 if (!rl || rl == (char *) EOF) 505 { 506 got_eof = 1; 507 command_handler (0); 508 return; /* Lint. */ 509 } 510 if (strlen (rl) + 1 + (p - linebuffer) > linelength) 511 { 512 linelength = strlen (rl) + 1 + (p - linebuffer); 513 nline = (char *) xrealloc (linebuffer, linelength); 514 p += nline - linebuffer; 515 linebuffer = nline; 516 } 517 p1 = rl; 518 /* Copy line. Don't copy null at end. (Leaves line alone 519 if this was just a newline). */ 520 while (*p1) 521 *p++ = *p1++; 522 523 xfree (rl); /* Allocated in readline. */ 524 525 if (p > linebuffer && *(p - 1) == '\\') 526 { 527 *p = '\0'; 528 p--; /* Put on top of '\'. */ 529 530 readline_input_state.linebuffer = xstrdup (linebuffer); 531 readline_input_state.linebuffer_ptr = p; 532 533 /* We will not invoke a execute_command if there is more 534 input expected to complete the command. So, we need to 535 print an empty prompt here. */ 536 more_to_come = 1; 537 display_gdb_prompt (""); 538 return; 539 } 540 541 #ifdef STOP_SIGNAL 542 if (job_control) 543 signal (STOP_SIGNAL, SIG_DFL); 544 #endif 545 546 #define SERVER_COMMAND_LENGTH 7 547 server_command = 548 (p - linebuffer > SERVER_COMMAND_LENGTH) 549 && strncmp (linebuffer, "server ", SERVER_COMMAND_LENGTH) == 0; 550 if (server_command) 551 { 552 /* Note that we don't set `line'. Between this and the check in 553 dont_repeat, this insures that repeating will still do the 554 right thing. */ 555 *p = '\0'; 556 command_handler (linebuffer + SERVER_COMMAND_LENGTH); 557 display_gdb_prompt (0); 558 return; 559 } 560 561 /* Do history expansion if that is wished. */ 562 if (history_expansion_p && instream == stdin 563 && ISATTY (instream)) 564 { 565 char *history_value; 566 int expanded; 567 568 *p = '\0'; /* Insert null now. */ 569 expanded = history_expand (linebuffer, &history_value); 570 if (expanded) 571 { 572 /* Print the changes. */ 573 printf_unfiltered ("%s\n", history_value); 574 575 /* If there was an error, call this function again. */ 576 if (expanded < 0) 577 { 578 xfree (history_value); 579 return; 580 } 581 if (strlen (history_value) > linelength) 582 { 583 linelength = strlen (history_value) + 1; 584 linebuffer = (char *) xrealloc (linebuffer, linelength); 585 } 586 strcpy (linebuffer, history_value); 587 p = linebuffer + strlen (linebuffer); 588 } 589 xfree (history_value); 590 } 591 592 /* If we just got an empty line, and that is supposed to repeat the 593 previous command, return the value in the global buffer. */ 594 if (repeat && p == linebuffer && *p != '\\') 595 { 596 command_handler (saved_command_line); 597 display_gdb_prompt (0); 598 return; 599 } 600 601 for (p1 = linebuffer; *p1 == ' ' || *p1 == '\t'; p1++); 602 if (repeat && !*p1) 603 { 604 command_handler (saved_command_line); 605 display_gdb_prompt (0); 606 return; 607 } 608 609 *p = 0; 610 611 /* Add line to history if appropriate. */ 612 if (instream == stdin 613 && ISATTY (stdin) && *linebuffer) 614 add_history (linebuffer); 615 616 /* Note: lines consisting solely of comments are added to the command 617 history. This is useful when you type a command, and then 618 realize you don't want to execute it quite yet. You can comment 619 out the command and then later fetch it from the value history 620 and remove the '#'. The kill ring is probably better, but some 621 people are in the habit of commenting things out. */ 622 if (*p1 == '#') 623 *p1 = '\0'; /* Found a comment. */ 624 625 /* Save into global buffer if appropriate. */ 626 if (repeat) 627 { 628 if (linelength > saved_command_line_size) 629 { 630 saved_command_line = xrealloc (saved_command_line, linelength); 631 saved_command_line_size = linelength; 632 } 633 strcpy (saved_command_line, linebuffer); 634 if (!more_to_come) 635 { 636 command_handler (saved_command_line); 637 display_gdb_prompt (0); 638 } 639 return; 640 } 641 642 command_handler (linebuffer); 643 display_gdb_prompt (0); 644 return; 645 } 646 647 /* Does reading of input from terminal w/o the editing features 648 provided by the readline library. */ 649 650 /* NOTE: 1999-04-30 Asynchronous version of gdb_readline; gdb_readline 651 will become obsolete when the event loop is made the default 652 execution for gdb. */ 653 void 654 gdb_readline2 (gdb_client_data client_data) 655 { 656 int c; 657 char *result; 658 int input_index = 0; 659 int result_size = 80; 660 static int done_once = 0; 661 662 /* Unbuffer the input stream, so that, later on, the calls to fgetc 663 fetch only one char at the time from the stream. The fgetc's will 664 get up to the first newline, but there may be more chars in the 665 stream after '\n'. If we buffer the input and fgetc drains the 666 stream, getting stuff beyond the newline as well, a select, done 667 afterwards will not trigger. */ 668 if (!done_once && !ISATTY (instream)) 669 { 670 setbuf (instream, NULL); 671 done_once = 1; 672 } 673 674 result = (char *) xmalloc (result_size); 675 676 /* We still need the while loop here, even though it would seem 677 obvious to invoke gdb_readline2 at every character entered. If 678 not using the readline library, the terminal is in cooked mode, 679 which sends the characters all at once. Poll will notice that the 680 input fd has changed state only after enter is pressed. At this 681 point we still need to fetch all the chars entered. */ 682 683 while (1) 684 { 685 /* Read from stdin if we are executing a user defined command. 686 This is the right thing for prompt_for_continue, at least. */ 687 c = fgetc (instream ? instream : stdin); 688 689 if (c == EOF) 690 { 691 if (input_index > 0) 692 /* The last line does not end with a newline. Return it, 693 and if we are called again fgetc will still return EOF 694 and we'll return NULL then. */ 695 break; 696 xfree (result); 697 (*input_handler) (0); 698 return; 699 } 700 701 if (c == '\n') 702 { 703 if (input_index > 0 && result[input_index - 1] == '\r') 704 input_index--; 705 break; 706 } 707 708 result[input_index++] = c; 709 while (input_index >= result_size) 710 { 711 result_size *= 2; 712 result = (char *) xrealloc (result, result_size); 713 } 714 } 715 716 result[input_index++] = '\0'; 717 (*input_handler) (result); 718 } 719 720 721 /* Initialization of signal handlers and tokens. There is a function 722 handle_sig* for each of the signals GDB cares about. Specifically: 723 SIGINT, SIGFPE, SIGQUIT, SIGTSTP, SIGHUP, SIGWINCH. These 724 functions are the actual signal handlers associated to the signals 725 via calls to signal(). The only job for these functions is to 726 enqueue the appropriate event/procedure with the event loop. Such 727 procedures are the old signal handlers. The event loop will take 728 care of invoking the queued procedures to perform the usual tasks 729 associated with the reception of the signal. */ 730 /* NOTE: 1999-04-30 This is the asynchronous version of init_signals. 731 init_signals will become obsolete as we move to have to event loop 732 as the default for gdb. */ 733 void 734 async_init_signals (void) 735 { 736 signal (SIGINT, handle_sigint); 737 sigint_token = 738 create_async_signal_handler (async_request_quit, NULL); 739 signal (SIGTERM, handle_sigterm); 740 741 /* If SIGTRAP was set to SIG_IGN, then the SIG_IGN will get passed 742 to the inferior and breakpoints will be ignored. */ 743 #ifdef SIGTRAP 744 signal (SIGTRAP, SIG_DFL); 745 #endif 746 747 #ifdef SIGQUIT 748 /* If we initialize SIGQUIT to SIG_IGN, then the SIG_IGN will get 749 passed to the inferior, which we don't want. It would be 750 possible to do a "signal (SIGQUIT, SIG_DFL)" after we fork, but 751 on BSD4.3 systems using vfork, that can affect the 752 GDB process as well as the inferior (the signal handling tables 753 might be in memory, shared between the two). Since we establish 754 a handler for SIGQUIT, when we call exec it will set the signal 755 to SIG_DFL for us. */ 756 signal (SIGQUIT, handle_sigquit); 757 sigquit_token = 758 create_async_signal_handler (async_do_nothing, NULL); 759 #endif 760 #ifdef SIGHUP 761 if (signal (SIGHUP, handle_sighup) != SIG_IGN) 762 sighup_token = 763 create_async_signal_handler (async_disconnect, NULL); 764 else 765 sighup_token = 766 create_async_signal_handler (async_do_nothing, NULL); 767 #endif 768 signal (SIGFPE, handle_sigfpe); 769 sigfpe_token = 770 create_async_signal_handler (async_float_handler, NULL); 771 772 #if defined(SIGWINCH) && defined(SIGWINCH_HANDLER) 773 signal (SIGWINCH, handle_sigwinch); 774 sigwinch_token = 775 create_async_signal_handler (SIGWINCH_HANDLER, NULL); 776 #endif 777 #ifdef STOP_SIGNAL 778 sigtstp_token = 779 create_async_signal_handler (async_stop_sig, NULL); 780 #endif 781 782 } 783 784 void 785 mark_async_signal_handler_wrapper (void *token) 786 { 787 mark_async_signal_handler ((struct async_signal_handler *) token); 788 } 789 790 /* Tell the event loop what to do if SIGINT is received. 791 See event-signal.c. */ 792 void 793 handle_sigint (int sig) 794 { 795 signal (sig, handle_sigint); 796 797 /* We could be running in a loop reading in symfiles or something so 798 it may be quite a while before we get back to the event loop. So 799 set quit_flag to 1 here. Then if QUIT is called before we get to 800 the event loop, we will unwind as expected. */ 801 802 quit_flag = 1; 803 804 /* If immediate_quit is set, we go ahead and process the SIGINT right 805 away, even if we usually would defer this to the event loop. The 806 assumption here is that it is safe to process ^C immediately if 807 immediate_quit is set. If we didn't, SIGINT would be really 808 processed only the next time through the event loop. To get to 809 that point, though, the command that we want to interrupt needs to 810 finish first, which is unacceptable. If immediate quit is not set, 811 we process SIGINT the next time through the loop, which is fine. */ 812 gdb_call_async_signal_handler (sigint_token, immediate_quit); 813 } 814 815 /* Quit GDB if SIGTERM is received. 816 GDB would quit anyway, but this way it will clean up properly. */ 817 void 818 handle_sigterm (int sig) 819 { 820 signal (sig, handle_sigterm); 821 quit_force ((char *) 0, stdin == instream); 822 } 823 824 /* Do the quit. All the checks have been done by the caller. */ 825 void 826 async_request_quit (gdb_client_data arg) 827 { 828 /* If the quit_flag has gotten reset back to 0 by the time we get 829 back here, that means that an exception was thrown to unwind the 830 current command before we got back to the event loop. So there 831 is no reason to call quit again here, unless immediate_quit is 832 set. */ 833 834 if (quit_flag || immediate_quit) 835 quit (); 836 } 837 838 #ifdef SIGQUIT 839 /* Tell the event loop what to do if SIGQUIT is received. 840 See event-signal.c. */ 841 static void 842 handle_sigquit (int sig) 843 { 844 mark_async_signal_handler_wrapper (sigquit_token); 845 signal (sig, handle_sigquit); 846 } 847 #endif 848 849 #if defined (SIGQUIT) || defined (SIGHUP) 850 /* Called by the event loop in response to a SIGQUIT or an 851 ignored SIGHUP. */ 852 static void 853 async_do_nothing (gdb_client_data arg) 854 { 855 /* Empty function body. */ 856 } 857 #endif 858 859 #ifdef SIGHUP 860 /* Tell the event loop what to do if SIGHUP is received. 861 See event-signal.c. */ 862 static void 863 handle_sighup (int sig) 864 { 865 mark_async_signal_handler_wrapper (sighup_token); 866 signal (sig, handle_sighup); 867 } 868 869 /* Called by the event loop to process a SIGHUP. */ 870 static void 871 async_disconnect (gdb_client_data arg) 872 { 873 volatile struct gdb_exception exception; 874 875 TRY_CATCH (exception, RETURN_MASK_ALL) 876 { 877 quit_cover (); 878 } 879 880 if (exception.reason < 0) 881 { 882 fputs_filtered ("Could not kill the program being debugged", 883 gdb_stderr); 884 exception_print (gdb_stderr, exception); 885 } 886 887 TRY_CATCH (exception, RETURN_MASK_ALL) 888 { 889 pop_all_targets (1); 890 } 891 892 signal (SIGHUP, SIG_DFL); /*FIXME: ??????????? */ 893 raise (SIGHUP); 894 } 895 #endif 896 897 #ifdef STOP_SIGNAL 898 void 899 handle_stop_sig (int sig) 900 { 901 mark_async_signal_handler_wrapper (sigtstp_token); 902 signal (sig, handle_stop_sig); 903 } 904 905 static void 906 async_stop_sig (gdb_client_data arg) 907 { 908 char *prompt = get_prompt (); 909 910 #if STOP_SIGNAL == SIGTSTP 911 signal (SIGTSTP, SIG_DFL); 912 #if HAVE_SIGPROCMASK 913 { 914 sigset_t zero; 915 916 sigemptyset (&zero); 917 sigprocmask (SIG_SETMASK, &zero, 0); 918 } 919 #elif HAVE_SIGSETMASK 920 sigsetmask (0); 921 #endif 922 raise (SIGTSTP); 923 signal (SIGTSTP, handle_stop_sig); 924 #else 925 signal (STOP_SIGNAL, handle_stop_sig); 926 #endif 927 printf_unfiltered ("%s", prompt); 928 gdb_flush (gdb_stdout); 929 930 /* Forget about any previous command -- null line now will do 931 nothing. */ 932 dont_repeat (); 933 } 934 #endif /* STOP_SIGNAL */ 935 936 /* Tell the event loop what to do if SIGFPE is received. 937 See event-signal.c. */ 938 static void 939 handle_sigfpe (int sig) 940 { 941 mark_async_signal_handler_wrapper (sigfpe_token); 942 signal (sig, handle_sigfpe); 943 } 944 945 /* Event loop will call this functin to process a SIGFPE. */ 946 static void 947 async_float_handler (gdb_client_data arg) 948 { 949 /* This message is based on ANSI C, section 4.7. Note that integer 950 divide by zero causes this, so "float" is a misnomer. */ 951 error (_("Erroneous arithmetic operation.")); 952 } 953 954 /* Tell the event loop what to do if SIGWINCH is received. 955 See event-signal.c. */ 956 #if defined(SIGWINCH) && defined(SIGWINCH_HANDLER) 957 static void 958 handle_sigwinch (int sig) 959 { 960 mark_async_signal_handler_wrapper (sigwinch_token); 961 signal (sig, handle_sigwinch); 962 } 963 #endif 964 965 966 /* Called by do_setshow_command. */ 967 void 968 set_async_editing_command (char *args, int from_tty, 969 struct cmd_list_element *c) 970 { 971 change_line_handler (); 972 } 973 974 /* Set things up for readline to be invoked via the alternate 975 interface, i.e. via a callback function (rl_callback_read_char), 976 and hook up instream to the event loop. */ 977 void 978 gdb_setup_readline (void) 979 { 980 /* This function is a noop for the sync case. The assumption is 981 that the sync setup is ALL done in gdb_init, and we would only 982 mess it up here. The sync stuff should really go away over 983 time. */ 984 if (!batch_silent) 985 gdb_stdout = stdio_fileopen (stdout); 986 gdb_stderr = stdio_fileopen (stderr); 987 gdb_stdlog = gdb_stderr; /* for moment */ 988 gdb_stdtarg = gdb_stderr; /* for moment */ 989 gdb_stdtargerr = gdb_stderr; /* for moment */ 990 991 /* If the input stream is connected to a terminal, turn on 992 editing. */ 993 if (ISATTY (instream)) 994 { 995 /* Tell gdb that we will be using the readline library. This 996 could be overwritten by a command in .gdbinit like 'set 997 editing on' or 'off'. */ 998 async_command_editing_p = 1; 999 1000 /* When a character is detected on instream by select or poll, 1001 readline will be invoked via this callback function. */ 1002 call_readline = rl_callback_read_char_wrapper; 1003 } 1004 else 1005 { 1006 async_command_editing_p = 0; 1007 call_readline = gdb_readline2; 1008 } 1009 1010 /* When readline has read an end-of-line character, it passes the 1011 complete line to gdb for processing; command_line_handler is the 1012 function that does this. */ 1013 input_handler = command_line_handler; 1014 1015 /* Tell readline to use the same input stream that gdb uses. */ 1016 rl_instream = instream; 1017 1018 /* Get a file descriptor for the input stream, so that we can 1019 register it with the event loop. */ 1020 input_fd = fileno (instream); 1021 1022 /* Now we need to create the event sources for the input file 1023 descriptor. */ 1024 /* At this point in time, this is the only event source that we 1025 register with the even loop. Another source is going to be the 1026 target program (inferior), but that must be registered only when 1027 it actually exists (I.e. after we say 'run' or after we connect 1028 to a remote target. */ 1029 add_file_handler (input_fd, stdin_event_handler, 0); 1030 } 1031 1032 /* Disable command input through the standard CLI channels. Used in 1033 the suspend proc for interpreters that use the standard gdb readline 1034 interface, like the cli & the mi. */ 1035 void 1036 gdb_disable_readline (void) 1037 { 1038 /* FIXME - It is too heavyweight to delete and remake these every 1039 time you run an interpreter that needs readline. It is probably 1040 better to have the interpreters cache these, which in turn means 1041 that this needs to be moved into interpreter specific code. */ 1042 1043 #if 0 1044 ui_file_delete (gdb_stdout); 1045 ui_file_delete (gdb_stderr); 1046 gdb_stdlog = NULL; 1047 gdb_stdtarg = NULL; 1048 gdb_stdtargerr = NULL; 1049 #endif 1050 1051 rl_callback_handler_remove (); 1052 delete_file_handler (input_fd); 1053 } 1054