1 /* Top level stuff for GDB, the GNU debugger. 2 3 Copyright (C) 1999, 2000, 2001, 2002, 2004, 2005, 2007, 2008, 2009, 2010, 4 2011 Free Software 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 37 #include "gdbcmd.h" /* for dont_repeat() */ 38 39 /* readline include files. */ 40 #include "readline/readline.h" 41 #include "readline/history.h" 42 43 /* readline defines this. */ 44 #undef savestring 45 46 static void rl_callback_read_char_wrapper (gdb_client_data client_data); 47 static void command_line_handler (char *rl); 48 static void change_line_handler (void); 49 static void change_annotation_level (void); 50 static void command_handler (char *command); 51 52 /* Signal handlers. */ 53 #ifdef SIGQUIT 54 static void handle_sigquit (int sig); 55 #endif 56 #ifdef SIGHUP 57 static void handle_sighup (int sig); 58 #endif 59 static void handle_sigfpe (int sig); 60 #if defined(SIGWINCH) && defined(SIGWINCH_HANDLER) 61 static void handle_sigwinch (int sig); 62 #endif 63 64 /* Functions to be invoked by the event loop in response to 65 signals. */ 66 #if defined (SIGQUIT) || defined (SIGHUP) 67 static void async_do_nothing (gdb_client_data); 68 #endif 69 #ifdef SIGHUP 70 static void async_disconnect (gdb_client_data); 71 #endif 72 static void async_float_handler (gdb_client_data); 73 #ifdef STOP_SIGNAL 74 static void async_stop_sig (gdb_client_data); 75 #endif 76 77 /* Readline offers an alternate interface, via callback 78 functions. These are all included in the file callback.c in the 79 readline distribution. This file provides (mainly) a function, which 80 the event loop uses as callback (i.e. event handler) whenever an event 81 is detected on the standard input file descriptor. 82 readline_callback_read_char is called (by the GDB event loop) whenever 83 there is a new character ready on the input stream. This function 84 incrementally builds a buffer internal to readline where it 85 accumulates the line read up to the point of invocation. In the 86 special case in which the character read is newline, the function 87 invokes a GDB supplied callback routine, which does the processing of 88 a full command line. This latter routine is the asynchronous analog 89 of the old command_line_input in gdb. Instead of invoking (and waiting 90 for) readline to read the command line and pass it back to 91 command_loop for processing, the new command_line_handler function has 92 the command line already available as its parameter. INPUT_HANDLER is 93 to be set to the function that readline will invoke when a complete 94 line of input is ready. CALL_READLINE is to be set to the function 95 that readline offers as callback to the event_loop. */ 96 97 void (*input_handler) (char *); 98 void (*call_readline) (gdb_client_data); 99 100 /* Important variables for the event loop. */ 101 102 /* This is used to determine if GDB is using the readline library or 103 its own simplified form of readline. It is used by the asynchronous 104 form of the set editing command. 105 ezannoni: as of 1999-04-29 I expect that this 106 variable will not be used after gdb is changed to use the event 107 loop as default engine, and event-top.c is merged into top.c. */ 108 int async_command_editing_p; 109 110 /* This variable contains the new prompt that the user sets with the 111 set prompt command. */ 112 char *new_async_prompt; 113 114 /* This is the annotation suffix that will be used when the 115 annotation_level is 2. */ 116 char *async_annotation_suffix; 117 118 /* This is used to display the notification of the completion of an 119 asynchronous execution command. */ 120 int exec_done_display_p = 0; 121 122 /* This is the file descriptor for the input stream that GDB uses to 123 read commands from. */ 124 int input_fd; 125 126 /* This is the prompt stack. Prompts will be pushed on the stack as 127 needed by the different 'kinds' of user inputs GDB is asking 128 for. See event-loop.h. */ 129 struct prompts the_prompts; 130 131 /* Signal handling variables. */ 132 /* Each of these is a pointer to a function that the event loop will 133 invoke if the corresponding signal has received. The real signal 134 handlers mark these functions as ready to be executed and the event 135 loop, in a later iteration, calls them. See the function 136 invoke_async_signal_handler. */ 137 void *sigint_token; 138 #ifdef SIGHUP 139 void *sighup_token; 140 #endif 141 #ifdef SIGQUIT 142 void *sigquit_token; 143 #endif 144 void *sigfpe_token; 145 #if defined(SIGWINCH) && defined(SIGWINCH_HANDLER) 146 void *sigwinch_token; 147 #endif 148 #ifdef STOP_SIGNAL 149 void *sigtstp_token; 150 #endif 151 152 /* Structure to save a partially entered command. This is used when 153 the user types '\' at the end of a command line. This is necessary 154 because each line of input is handled by a different call to 155 command_line_handler, and normally there is no state retained 156 between different calls. */ 157 int more_to_come = 0; 158 159 struct readline_input_state 160 { 161 char *linebuffer; 162 char *linebuffer_ptr; 163 } 164 readline_input_state; 165 166 /* This hook is called by rl_callback_read_char_wrapper after each 167 character is processed. */ 168 void (*after_char_processing_hook) (void); 169 170 171 /* Wrapper function for calling into the readline library. The event 172 loop expects the callback function to have a paramter, while 173 readline expects none. */ 174 static void 175 rl_callback_read_char_wrapper (gdb_client_data client_data) 176 { 177 rl_callback_read_char (); 178 if (after_char_processing_hook) 179 (*after_char_processing_hook) (); 180 } 181 182 /* Initialize all the necessary variables, start the event loop, 183 register readline, and stdin, start the loop. */ 184 void 185 cli_command_loop (void) 186 { 187 /* If we are using readline, set things up and display the first 188 prompt, otherwise just print the prompt. */ 189 if (async_command_editing_p) 190 { 191 int length; 192 char *a_prompt; 193 char *gdb_prompt = get_prompt (); 194 195 /* Tell readline what the prompt to display is and what function 196 it will need to call after a whole line is read. This also 197 displays the first prompt. */ 198 length = strlen (PREFIX (0)) 199 + strlen (gdb_prompt) + strlen (SUFFIX (0)) + 1; 200 a_prompt = (char *) alloca (length); 201 strcpy (a_prompt, PREFIX (0)); 202 strcat (a_prompt, gdb_prompt); 203 strcat (a_prompt, SUFFIX (0)); 204 rl_callback_handler_install (a_prompt, input_handler); 205 } 206 else 207 display_gdb_prompt (0); 208 209 /* Now it's time to start the event loop. */ 210 start_event_loop (); 211 } 212 213 /* Change the function to be invoked every time there is a character 214 ready on stdin. This is used when the user sets the editing off, 215 therefore bypassing readline, and letting gdb handle the input 216 itself, via gdb_readline2. Also it is used in the opposite case in 217 which the user sets editing on again, by restoring readline 218 handling of the input. */ 219 static void 220 change_line_handler (void) 221 { 222 /* NOTE: this operates on input_fd, not instream. If we are reading 223 commands from a file, instream will point to the file. However in 224 async mode, we always read commands from a file with editing 225 off. This means that the 'set editing on/off' will have effect 226 only on the interactive session. */ 227 228 if (async_command_editing_p) 229 { 230 /* Turn on editing by using readline. */ 231 call_readline = rl_callback_read_char_wrapper; 232 input_handler = command_line_handler; 233 } 234 else 235 { 236 /* Turn off editing by using gdb_readline2. */ 237 rl_callback_handler_remove (); 238 call_readline = gdb_readline2; 239 240 /* Set up the command handler as well, in case we are called as 241 first thing from .gdbinit. */ 242 input_handler = command_line_handler; 243 } 244 } 245 246 /* Displays the prompt. The prompt that is displayed is the current 247 top of the prompt stack, if the argument NEW_PROMPT is 248 0. Otherwise, it displays whatever NEW_PROMPT is. This is used 249 after each gdb command has completed, and in the following cases: 250 1. When the user enters a command line which is ended by '\' 251 indicating that the command will continue on the next line. 252 In that case the prompt that is displayed is the empty string. 253 2. When the user is entering 'commands' for a breakpoint, or 254 actions for a tracepoint. In this case the prompt will be '>' 255 3. Other???? 256 FIXME: 2. & 3. not implemented yet for async. */ 257 void 258 display_gdb_prompt (char *new_prompt) 259 { 260 int prompt_length = 0; 261 char *gdb_prompt = get_prompt (); 262 263 /* Reset the nesting depth used when trace-commands is set. */ 264 reset_command_nest_depth (); 265 266 /* Each interpreter has its own rules on displaying the command 267 prompt. */ 268 if (!current_interp_display_prompt_p ()) 269 return; 270 271 if (sync_execution && is_running (inferior_ptid)) 272 { 273 /* This is to trick readline into not trying to display the 274 prompt. Even though we display the prompt using this 275 function, readline still tries to do its own display if we 276 don't call rl_callback_handler_install and 277 rl_callback_handler_remove (which readline detects because a 278 global variable is not set). If readline did that, it could 279 mess up gdb signal handlers for SIGINT. Readline assumes 280 that between calls to rl_set_signals and rl_clear_signals gdb 281 doesn't do anything with the signal handlers. Well, that's 282 not the case, because when the target executes we change the 283 SIGINT signal handler. If we allowed readline to display the 284 prompt, the signal handler change would happen exactly 285 between the calls to the above two functions. 286 Calling rl_callback_handler_remove(), does the job. */ 287 288 rl_callback_handler_remove (); 289 return; 290 } 291 292 if (!new_prompt) 293 { 294 /* Just use the top of the prompt stack. */ 295 prompt_length = strlen (PREFIX (0)) + 296 strlen (SUFFIX (0)) + 297 strlen (gdb_prompt) + 1; 298 299 new_prompt = (char *) alloca (prompt_length); 300 301 /* Prefix needs to have new line at end. */ 302 strcpy (new_prompt, PREFIX (0)); 303 strcat (new_prompt, gdb_prompt); 304 /* Suffix needs to have a new line at end and \032 \032 at 305 beginning. */ 306 strcat (new_prompt, SUFFIX (0)); 307 } 308 309 if (async_command_editing_p) 310 { 311 rl_callback_handler_remove (); 312 rl_callback_handler_install (new_prompt, input_handler); 313 } 314 /* new_prompt at this point can be the top of the stack or the one 315 passed in. It can't be NULL. */ 316 else 317 { 318 /* Don't use a _filtered function here. It causes the assumed 319 character position to be off, since the newline we read from 320 the user is not accounted for. */ 321 fputs_unfiltered (new_prompt, gdb_stdout); 322 gdb_flush (gdb_stdout); 323 } 324 } 325 326 /* Used when the user requests a different annotation level, with 327 'set annotate'. It pushes a new prompt (with prefix and suffix) on top 328 of the prompt stack, if the annotation level desired is 2, otherwise 329 it pops the top of the prompt stack when we want the annotation level 330 to be the normal ones (1 or 0). */ 331 static void 332 change_annotation_level (void) 333 { 334 char *prefix, *suffix; 335 336 if (!PREFIX (0) || !PROMPT (0) || !SUFFIX (0)) 337 { 338 /* The prompt stack has not been initialized to "", we are 339 using gdb w/o the --async switch. */ 340 warning (_("Command has same effect as set annotate")); 341 return; 342 } 343 344 if (annotation_level > 1) 345 { 346 if (!strcmp (PREFIX (0), "") && !strcmp (SUFFIX (0), "")) 347 { 348 /* Push a new prompt if the previous annotation_level was not >1. */ 349 prefix = (char *) alloca (strlen (async_annotation_suffix) + 10); 350 strcpy (prefix, "\n\032\032pre-"); 351 strcat (prefix, async_annotation_suffix); 352 strcat (prefix, "\n"); 353 354 suffix = (char *) alloca (strlen (async_annotation_suffix) + 6); 355 strcpy (suffix, "\n\032\032"); 356 strcat (suffix, async_annotation_suffix); 357 strcat (suffix, "\n"); 358 359 push_prompt (prefix, (char *) 0, suffix); 360 } 361 } 362 else 363 { 364 if (strcmp (PREFIX (0), "") && strcmp (SUFFIX (0), "")) 365 { 366 /* Pop the top of the stack, we are going back to annotation < 1. */ 367 pop_prompt (); 368 } 369 } 370 } 371 372 /* Pushes a new prompt on the prompt stack. Each prompt has three 373 parts: prefix, prompt, suffix. Usually prefix and suffix are empty 374 strings, except when the annotation level is 2. Memory is allocated 375 within xstrdup for the new prompt. */ 376 void 377 push_prompt (char *prefix, char *prompt, char *suffix) 378 { 379 the_prompts.top++; 380 PREFIX (0) = xstrdup (prefix); 381 382 /* Note that this function is used by the set annotate 2 383 command. This is why we take care of saving the old prompt 384 in case a new one is not specified. */ 385 if (prompt) 386 PROMPT (0) = xstrdup (prompt); 387 else 388 PROMPT (0) = xstrdup (PROMPT (-1)); 389 390 SUFFIX (0) = xstrdup (suffix); 391 } 392 393 /* Pops the top of the prompt stack, and frees the memory allocated 394 for it. */ 395 void 396 pop_prompt (void) 397 { 398 /* If we are not during a 'synchronous' execution command, in which 399 case, the top prompt would be empty. */ 400 if (strcmp (PROMPT (0), "")) 401 /* This is for the case in which the prompt is set while the 402 annotation level is 2. The top prompt will be changed, but when 403 we return to annotation level < 2, we want that new prompt to be 404 in effect, until the user does another 'set prompt'. */ 405 if (strcmp (PROMPT (0), PROMPT (-1))) 406 { 407 xfree (PROMPT (-1)); 408 PROMPT (-1) = xstrdup (PROMPT (0)); 409 } 410 411 xfree (PREFIX (0)); 412 xfree (PROMPT (0)); 413 xfree (SUFFIX (0)); 414 the_prompts.top--; 415 } 416 417 /* When there is an event ready on the stdin file desriptor, instead 418 of calling readline directly throught the callback function, or 419 instead of calling gdb_readline2, give gdb a chance to detect 420 errors and do something. */ 421 void 422 stdin_event_handler (int error, gdb_client_data client_data) 423 { 424 if (error) 425 { 426 printf_unfiltered (_("error detected on stdin\n")); 427 delete_file_handler (input_fd); 428 discard_all_continuations (); 429 discard_all_intermediate_continuations (); 430 /* If stdin died, we may as well kill gdb. */ 431 quit_command ((char *) 0, stdin == instream); 432 } 433 else 434 (*call_readline) (client_data); 435 } 436 437 /* Re-enable stdin after the end of an execution command in 438 synchronous mode, or after an error from the target, and we aborted 439 the exec operation. */ 440 441 void 442 async_enable_stdin (void) 443 { 444 if (sync_execution) 445 { 446 /* See NOTE in async_disable_stdin(). */ 447 /* FIXME: cagney/1999-09-27: Call this before clearing 448 sync_execution. Current target_terminal_ours() implementations 449 check for sync_execution before switching the terminal. */ 450 target_terminal_ours (); 451 pop_prompt (); 452 sync_execution = 0; 453 } 454 } 455 456 /* Disable reads from stdin (the console) marking the command as 457 synchronous. */ 458 459 void 460 async_disable_stdin (void) 461 { 462 if (!sync_execution) 463 { 464 sync_execution = 1; 465 push_prompt ("", "", ""); 466 } 467 } 468 469 470 /* Handles a gdb command. This function is called by 471 command_line_handler, which has processed one or more input lines 472 into COMMAND. */ 473 /* NOTE: 1999-04-30 This is the asynchronous version of the command_loop 474 function. The command_loop function will be obsolete when we 475 switch to use the event loop at every execution of gdb. */ 476 static void 477 command_handler (char *command) 478 { 479 int stdin_is_tty = ISATTY (stdin); 480 struct cleanup *stat_chain; 481 482 quit_flag = 0; 483 if (instream == stdin && stdin_is_tty) 484 reinitialize_more_filter (); 485 486 /* If readline returned a NULL command, it means that the connection 487 with the terminal is gone. This happens at the end of a 488 testsuite run, after Expect has hung up but GDB is still alive. 489 In such a case, we just quit gdb killing the inferior program 490 too. */ 491 if (command == 0) 492 { 493 printf_unfiltered ("quit\n"); 494 execute_command ("quit", stdin == instream); 495 } 496 497 stat_chain = make_command_stats_cleanup (1); 498 499 execute_command (command, instream == stdin); 500 501 /* Do any commands attached to breakpoint we stopped at. */ 502 bpstat_do_actions (); 503 504 do_cleanups (stat_chain); 505 } 506 507 /* Handle a complete line of input. This is called by the callback 508 mechanism within the readline library. Deal with incomplete 509 commands as well, by saving the partial input in a global 510 buffer. */ 511 512 /* NOTE: 1999-04-30 This is the asynchronous version of the 513 command_line_input function; command_line_input will become 514 obsolete once we use the event loop as the default mechanism in 515 GDB. */ 516 static void 517 command_line_handler (char *rl) 518 { 519 static char *linebuffer = 0; 520 static unsigned linelength = 0; 521 char *p; 522 char *p1; 523 extern char *line; 524 extern int linesize; 525 char *nline; 526 char got_eof = 0; 527 528 int repeat = (instream == stdin); 529 530 if (annotation_level > 1 && instream == stdin) 531 { 532 printf_unfiltered (("\n\032\032post-")); 533 puts_unfiltered (async_annotation_suffix); 534 printf_unfiltered (("\n")); 535 } 536 537 if (linebuffer == 0) 538 { 539 linelength = 80; 540 linebuffer = (char *) xmalloc (linelength); 541 } 542 543 p = linebuffer; 544 545 if (more_to_come) 546 { 547 strcpy (linebuffer, readline_input_state.linebuffer); 548 p = readline_input_state.linebuffer_ptr; 549 xfree (readline_input_state.linebuffer); 550 more_to_come = 0; 551 pop_prompt (); 552 } 553 554 #ifdef STOP_SIGNAL 555 if (job_control) 556 signal (STOP_SIGNAL, handle_stop_sig); 557 #endif 558 559 /* Make sure that all output has been output. Some machines may let 560 you get away with leaving out some of the gdb_flush, but not 561 all. */ 562 wrap_here (""); 563 gdb_flush (gdb_stdout); 564 gdb_flush (gdb_stderr); 565 566 if (source_file_name != NULL) 567 ++source_line_number; 568 569 /* If we are in this case, then command_handler will call quit 570 and exit from gdb. */ 571 if (!rl || rl == (char *) EOF) 572 { 573 got_eof = 1; 574 command_handler (0); 575 return; /* Lint. */ 576 } 577 if (strlen (rl) + 1 + (p - linebuffer) > linelength) 578 { 579 linelength = strlen (rl) + 1 + (p - linebuffer); 580 nline = (char *) xrealloc (linebuffer, linelength); 581 p += nline - linebuffer; 582 linebuffer = nline; 583 } 584 p1 = rl; 585 /* Copy line. Don't copy null at end. (Leaves line alone 586 if this was just a newline). */ 587 while (*p1) 588 *p++ = *p1++; 589 590 xfree (rl); /* Allocated in readline. */ 591 592 if (p > linebuffer && *(p - 1) == '\\') 593 { 594 *p = '\0'; 595 p--; /* Put on top of '\'. */ 596 597 readline_input_state.linebuffer = xstrdup (linebuffer); 598 readline_input_state.linebuffer_ptr = p; 599 600 /* We will not invoke a execute_command if there is more 601 input expected to complete the command. So, we need to 602 print an empty prompt here. */ 603 more_to_come = 1; 604 push_prompt ("", "", ""); 605 display_gdb_prompt (0); 606 return; 607 } 608 609 #ifdef STOP_SIGNAL 610 if (job_control) 611 signal (STOP_SIGNAL, SIG_DFL); 612 #endif 613 614 #define SERVER_COMMAND_LENGTH 7 615 server_command = 616 (p - linebuffer > SERVER_COMMAND_LENGTH) 617 && strncmp (linebuffer, "server ", SERVER_COMMAND_LENGTH) == 0; 618 if (server_command) 619 { 620 /* Note that we don't set `line'. Between this and the check in 621 dont_repeat, this insures that repeating will still do the 622 right thing. */ 623 *p = '\0'; 624 command_handler (linebuffer + SERVER_COMMAND_LENGTH); 625 display_gdb_prompt (0); 626 return; 627 } 628 629 /* Do history expansion if that is wished. */ 630 if (history_expansion_p && instream == stdin 631 && ISATTY (instream)) 632 { 633 char *history_value; 634 int expanded; 635 636 *p = '\0'; /* Insert null now. */ 637 expanded = history_expand (linebuffer, &history_value); 638 if (expanded) 639 { 640 /* Print the changes. */ 641 printf_unfiltered ("%s\n", history_value); 642 643 /* If there was an error, call this function again. */ 644 if (expanded < 0) 645 { 646 xfree (history_value); 647 return; 648 } 649 if (strlen (history_value) > linelength) 650 { 651 linelength = strlen (history_value) + 1; 652 linebuffer = (char *) xrealloc (linebuffer, linelength); 653 } 654 strcpy (linebuffer, history_value); 655 p = linebuffer + strlen (linebuffer); 656 } 657 xfree (history_value); 658 } 659 660 /* If we just got an empty line, and that is supposed to repeat the 661 previous command, return the value in the global buffer. */ 662 if (repeat && p == linebuffer && *p != '\\') 663 { 664 command_handler (line); 665 display_gdb_prompt (0); 666 return; 667 } 668 669 for (p1 = linebuffer; *p1 == ' ' || *p1 == '\t'; p1++); 670 if (repeat && !*p1) 671 { 672 command_handler (line); 673 display_gdb_prompt (0); 674 return; 675 } 676 677 *p = 0; 678 679 /* Add line to history if appropriate. */ 680 if (instream == stdin 681 && ISATTY (stdin) && *linebuffer) 682 add_history (linebuffer); 683 684 /* Note: lines consisting solely of comments are added to the command 685 history. This is useful when you type a command, and then 686 realize you don't want to execute it quite yet. You can comment 687 out the command and then later fetch it from the value history 688 and remove the '#'. The kill ring is probably better, but some 689 people are in the habit of commenting things out. */ 690 if (*p1 == '#') 691 *p1 = '\0'; /* Found a comment. */ 692 693 /* Save into global buffer if appropriate. */ 694 if (repeat) 695 { 696 if (linelength > linesize) 697 { 698 line = xrealloc (line, linelength); 699 linesize = linelength; 700 } 701 strcpy (line, linebuffer); 702 if (!more_to_come) 703 { 704 command_handler (line); 705 display_gdb_prompt (0); 706 } 707 return; 708 } 709 710 command_handler (linebuffer); 711 display_gdb_prompt (0); 712 return; 713 } 714 715 /* Does reading of input from terminal w/o the editing features 716 provided by the readline library. */ 717 718 /* NOTE: 1999-04-30 Asynchronous version of gdb_readline; gdb_readline 719 will become obsolete when the event loop is made the default 720 execution for gdb. */ 721 void 722 gdb_readline2 (gdb_client_data client_data) 723 { 724 int c; 725 char *result; 726 int input_index = 0; 727 int result_size = 80; 728 static int done_once = 0; 729 730 /* Unbuffer the input stream, so that, later on, the calls to fgetc 731 fetch only one char at the time from the stream. The fgetc's will 732 get up to the first newline, but there may be more chars in the 733 stream after '\n'. If we buffer the input and fgetc drains the 734 stream, getting stuff beyond the newline as well, a select, done 735 afterwards will not trigger. */ 736 if (!done_once && !ISATTY (instream)) 737 { 738 setbuf (instream, NULL); 739 done_once = 1; 740 } 741 742 result = (char *) xmalloc (result_size); 743 744 /* We still need the while loop here, even though it would seem 745 obvious to invoke gdb_readline2 at every character entered. If 746 not using the readline library, the terminal is in cooked mode, 747 which sends the characters all at once. Poll will notice that the 748 input fd has changed state only after enter is pressed. At this 749 point we still need to fetch all the chars entered. */ 750 751 while (1) 752 { 753 /* Read from stdin if we are executing a user defined command. 754 This is the right thing for prompt_for_continue, at least. */ 755 c = fgetc (instream ? instream : stdin); 756 757 if (c == EOF) 758 { 759 if (input_index > 0) 760 /* The last line does not end with a newline. Return it, 761 and if we are called again fgetc will still return EOF 762 and we'll return NULL then. */ 763 break; 764 xfree (result); 765 (*input_handler) (0); 766 return; 767 } 768 769 if (c == '\n') 770 { 771 if (input_index > 0 && result[input_index - 1] == '\r') 772 input_index--; 773 break; 774 } 775 776 result[input_index++] = c; 777 while (input_index >= result_size) 778 { 779 result_size *= 2; 780 result = (char *) xrealloc (result, result_size); 781 } 782 } 783 784 result[input_index++] = '\0'; 785 (*input_handler) (result); 786 } 787 788 789 /* Initialization of signal handlers and tokens. There is a function 790 handle_sig* for each of the signals GDB cares about. Specifically: 791 SIGINT, SIGFPE, SIGQUIT, SIGTSTP, SIGHUP, SIGWINCH. These 792 functions are the actual signal handlers associated to the signals 793 via calls to signal(). The only job for these functions is to 794 enqueue the appropriate event/procedure with the event loop. Such 795 procedures are the old signal handlers. The event loop will take 796 care of invoking the queued procedures to perform the usual tasks 797 associated with the reception of the signal. */ 798 /* NOTE: 1999-04-30 This is the asynchronous version of init_signals. 799 init_signals will become obsolete as we move to have to event loop 800 as the default for gdb. */ 801 void 802 async_init_signals (void) 803 { 804 signal (SIGINT, handle_sigint); 805 sigint_token = 806 create_async_signal_handler (async_request_quit, NULL); 807 signal (SIGTERM, handle_sigterm); 808 809 /* If SIGTRAP was set to SIG_IGN, then the SIG_IGN will get passed 810 to the inferior and breakpoints will be ignored. */ 811 #ifdef SIGTRAP 812 signal (SIGTRAP, SIG_DFL); 813 #endif 814 815 #ifdef SIGQUIT 816 /* If we initialize SIGQUIT to SIG_IGN, then the SIG_IGN will get 817 passed to the inferior, which we don't want. It would be 818 possible to do a "signal (SIGQUIT, SIG_DFL)" after we fork, but 819 on BSD4.3 systems using vfork, that can affect the 820 GDB process as well as the inferior (the signal handling tables 821 might be in memory, shared between the two). Since we establish 822 a handler for SIGQUIT, when we call exec it will set the signal 823 to SIG_DFL for us. */ 824 signal (SIGQUIT, handle_sigquit); 825 sigquit_token = 826 create_async_signal_handler (async_do_nothing, NULL); 827 #endif 828 #ifdef SIGHUP 829 if (signal (SIGHUP, handle_sighup) != SIG_IGN) 830 sighup_token = 831 create_async_signal_handler (async_disconnect, NULL); 832 else 833 sighup_token = 834 create_async_signal_handler (async_do_nothing, NULL); 835 #endif 836 signal (SIGFPE, handle_sigfpe); 837 sigfpe_token = 838 create_async_signal_handler (async_float_handler, NULL); 839 840 #if defined(SIGWINCH) && defined(SIGWINCH_HANDLER) 841 signal (SIGWINCH, handle_sigwinch); 842 sigwinch_token = 843 create_async_signal_handler (SIGWINCH_HANDLER, NULL); 844 #endif 845 #ifdef STOP_SIGNAL 846 sigtstp_token = 847 create_async_signal_handler (async_stop_sig, NULL); 848 #endif 849 850 } 851 852 void 853 mark_async_signal_handler_wrapper (void *token) 854 { 855 mark_async_signal_handler ((struct async_signal_handler *) token); 856 } 857 858 /* Tell the event loop what to do if SIGINT is received. 859 See event-signal.c. */ 860 void 861 handle_sigint (int sig) 862 { 863 signal (sig, handle_sigint); 864 865 /* We could be running in a loop reading in symfiles or something so 866 it may be quite a while before we get back to the event loop. So 867 set quit_flag to 1 here. Then if QUIT is called before we get to 868 the event loop, we will unwind as expected. */ 869 870 quit_flag = 1; 871 872 /* If immediate_quit is set, we go ahead and process the SIGINT right 873 away, even if we usually would defer this to the event loop. The 874 assumption here is that it is safe to process ^C immediately if 875 immediate_quit is set. If we didn't, SIGINT would be really 876 processed only the next time through the event loop. To get to 877 that point, though, the command that we want to interrupt needs to 878 finish first, which is unacceptable. If immediate quit is not set, 879 we process SIGINT the next time through the loop, which is fine. */ 880 gdb_call_async_signal_handler (sigint_token, immediate_quit); 881 } 882 883 /* Quit GDB if SIGTERM is received. 884 GDB would quit anyway, but this way it will clean up properly. */ 885 void 886 handle_sigterm (int sig) 887 { 888 signal (sig, handle_sigterm); 889 quit_force ((char *) 0, stdin == instream); 890 } 891 892 /* Do the quit. All the checks have been done by the caller. */ 893 void 894 async_request_quit (gdb_client_data arg) 895 { 896 /* If the quit_flag has gotten reset back to 0 by the time we get 897 back here, that means that an exception was thrown to unwind the 898 current command before we got back to the event loop. So there 899 is no reason to call quit again here, unless immediate_quit is 900 set. */ 901 902 if (quit_flag || immediate_quit) 903 quit (); 904 } 905 906 #ifdef SIGQUIT 907 /* Tell the event loop what to do if SIGQUIT is received. 908 See event-signal.c. */ 909 static void 910 handle_sigquit (int sig) 911 { 912 mark_async_signal_handler_wrapper (sigquit_token); 913 signal (sig, handle_sigquit); 914 } 915 #endif 916 917 #if defined (SIGQUIT) || defined (SIGHUP) 918 /* Called by the event loop in response to a SIGQUIT or an 919 ignored SIGHUP. */ 920 static void 921 async_do_nothing (gdb_client_data arg) 922 { 923 /* Empty function body. */ 924 } 925 #endif 926 927 #ifdef SIGHUP 928 /* Tell the event loop what to do if SIGHUP is received. 929 See event-signal.c. */ 930 static void 931 handle_sighup (int sig) 932 { 933 mark_async_signal_handler_wrapper (sighup_token); 934 signal (sig, handle_sighup); 935 } 936 937 /* Called by the event loop to process a SIGHUP. */ 938 static void 939 async_disconnect (gdb_client_data arg) 940 { 941 catch_errors (quit_cover, NULL, 942 "Could not kill the program being debugged", 943 RETURN_MASK_ALL); 944 signal (SIGHUP, SIG_DFL); /*FIXME: ??????????? */ 945 raise (SIGHUP); 946 } 947 #endif 948 949 #ifdef STOP_SIGNAL 950 void 951 handle_stop_sig (int sig) 952 { 953 mark_async_signal_handler_wrapper (sigtstp_token); 954 signal (sig, handle_stop_sig); 955 } 956 957 static void 958 async_stop_sig (gdb_client_data arg) 959 { 960 char *prompt = get_prompt (); 961 962 #if STOP_SIGNAL == SIGTSTP 963 signal (SIGTSTP, SIG_DFL); 964 #if HAVE_SIGPROCMASK 965 { 966 sigset_t zero; 967 968 sigemptyset (&zero); 969 sigprocmask (SIG_SETMASK, &zero, 0); 970 } 971 #elif HAVE_SIGSETMASK 972 sigsetmask (0); 973 #endif 974 raise (SIGTSTP); 975 signal (SIGTSTP, handle_stop_sig); 976 #else 977 signal (STOP_SIGNAL, handle_stop_sig); 978 #endif 979 printf_unfiltered ("%s", prompt); 980 gdb_flush (gdb_stdout); 981 982 /* Forget about any previous command -- null line now will do 983 nothing. */ 984 dont_repeat (); 985 } 986 #endif /* STOP_SIGNAL */ 987 988 /* Tell the event loop what to do if SIGFPE is received. 989 See event-signal.c. */ 990 static void 991 handle_sigfpe (int sig) 992 { 993 mark_async_signal_handler_wrapper (sigfpe_token); 994 signal (sig, handle_sigfpe); 995 } 996 997 /* Event loop will call this functin to process a SIGFPE. */ 998 static void 999 async_float_handler (gdb_client_data arg) 1000 { 1001 /* This message is based on ANSI C, section 4.7. Note that integer 1002 divide by zero causes this, so "float" is a misnomer. */ 1003 error (_("Erroneous arithmetic operation.")); 1004 } 1005 1006 /* Tell the event loop what to do if SIGWINCH is received. 1007 See event-signal.c. */ 1008 #if defined(SIGWINCH) && defined(SIGWINCH_HANDLER) 1009 static void 1010 handle_sigwinch (int sig) 1011 { 1012 mark_async_signal_handler_wrapper (sigwinch_token); 1013 signal (sig, handle_sigwinch); 1014 } 1015 #endif 1016 1017 1018 /* Called by do_setshow_command. */ 1019 void 1020 set_async_editing_command (char *args, int from_tty, 1021 struct cmd_list_element *c) 1022 { 1023 change_line_handler (); 1024 } 1025 1026 /* Called by do_setshow_command. */ 1027 void 1028 set_async_annotation_level (char *args, int from_tty, 1029 struct cmd_list_element *c) 1030 { 1031 change_annotation_level (); 1032 } 1033 1034 /* Called by do_setshow_command. */ 1035 void 1036 set_async_prompt (char *args, int from_tty, struct cmd_list_element *c) 1037 { 1038 PROMPT (0) = xstrdup (new_async_prompt); 1039 } 1040 1041 /* Set things up for readline to be invoked via the alternate 1042 interface, i.e. via a callback function (rl_callback_read_char), 1043 and hook up instream to the event loop. */ 1044 void 1045 gdb_setup_readline (void) 1046 { 1047 /* This function is a noop for the sync case. The assumption is 1048 that the sync setup is ALL done in gdb_init, and we would only 1049 mess it up here. The sync stuff should really go away over 1050 time. */ 1051 if (!batch_silent) 1052 gdb_stdout = stdio_fileopen (stdout); 1053 gdb_stderr = stdio_fileopen (stderr); 1054 gdb_stdlog = gdb_stderr; /* for moment */ 1055 gdb_stdtarg = gdb_stderr; /* for moment */ 1056 gdb_stdtargerr = gdb_stderr; /* for moment */ 1057 1058 /* If the input stream is connected to a terminal, turn on 1059 editing. */ 1060 if (ISATTY (instream)) 1061 { 1062 /* Tell gdb that we will be using the readline library. This 1063 could be overwritten by a command in .gdbinit like 'set 1064 editing on' or 'off'. */ 1065 async_command_editing_p = 1; 1066 1067 /* When a character is detected on instream by select or poll, 1068 readline will be invoked via this callback function. */ 1069 call_readline = rl_callback_read_char_wrapper; 1070 } 1071 else 1072 { 1073 async_command_editing_p = 0; 1074 call_readline = gdb_readline2; 1075 } 1076 1077 /* When readline has read an end-of-line character, it passes the 1078 complete line to gdb for processing; command_line_handler is the 1079 function that does this. */ 1080 input_handler = command_line_handler; 1081 1082 /* Tell readline to use the same input stream that gdb uses. */ 1083 rl_instream = instream; 1084 1085 /* Get a file descriptor for the input stream, so that we can 1086 register it with the event loop. */ 1087 input_fd = fileno (instream); 1088 1089 /* Now we need to create the event sources for the input file 1090 descriptor. */ 1091 /* At this point in time, this is the only event source that we 1092 register with the even loop. Another source is going to be the 1093 target program (inferior), but that must be registered only when 1094 it actually exists (I.e. after we say 'run' or after we connect 1095 to a remote target. */ 1096 add_file_handler (input_fd, stdin_event_handler, 0); 1097 } 1098 1099 /* Disable command input through the standard CLI channels. Used in 1100 the suspend proc for interpreters that use the standard gdb readline 1101 interface, like the cli & the mi. */ 1102 void 1103 gdb_disable_readline (void) 1104 { 1105 /* FIXME - It is too heavyweight to delete and remake these every 1106 time you run an interpreter that needs readline. It is probably 1107 better to have the interpreters cache these, which in turn means 1108 that this needs to be moved into interpreter specific code. */ 1109 1110 #if 0 1111 ui_file_delete (gdb_stdout); 1112 ui_file_delete (gdb_stderr); 1113 gdb_stdlog = NULL; 1114 gdb_stdtarg = NULL; 1115 gdb_stdtargerr = NULL; 1116 #endif 1117 1118 rl_callback_handler_remove (); 1119 delete_file_handler (input_fd); 1120 } 1121