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