| 1 | /* Top level stuff for GDB, the GNU debugger. |
| 2 | |
| 3 | Copyright (C) 1999-2013 Free Software Foundation, Inc. |
| 4 | |
| 5 | Written by Elena Zannoni <ezannoni@cygnus.com> of Cygnus Solutions. |
| 6 | |
| 7 | This file is part of GDB. |
| 8 | |
| 9 | This program is free software; you can redistribute it and/or modify |
| 10 | it under the terms of the GNU General Public License as published by |
| 11 | the Free Software Foundation; either version 3 of the License, or |
| 12 | (at your option) any later version. |
| 13 | |
| 14 | This program is distributed in the hope that it will be useful, |
| 15 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 16 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 17 | GNU General Public License for more details. |
| 18 | |
| 19 | You should have received a copy of the GNU General Public License |
| 20 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 21 | |
| 22 | #include "defs.h" |
| 23 | #include "top.h" |
| 24 | #include "inferior.h" |
| 25 | #include "target.h" |
| 26 | #include "terminal.h" /* for job_control */ |
| 27 | #include "event-loop.h" |
| 28 | #include "event-top.h" |
| 29 | #include "interps.h" |
| 30 | #include <signal.h> |
| 31 | #include "exceptions.h" |
| 32 | #include "cli/cli-script.h" /* for reset_command_nest_depth */ |
| 33 | #include "main.h" |
| 34 | #include "gdbthread.h" |
| 35 | #include "observer.h" |
| 36 | #include "continuations.h" |
| 37 | #include "gdbcmd.h" /* for dont_repeat() */ |
| 38 | #include "annotate.h" |
| 39 | #include "maint.h" |
| 40 | |
| 41 | /* readline include files. */ |
| 42 | #include "readline/readline.h" |
| 43 | #include "readline/history.h" |
| 44 | |
| 45 | /* readline defines this. */ |
| 46 | #undef savestring |
| 47 | |
| 48 | static void rl_callback_read_char_wrapper (gdb_client_data client_data); |
| 49 | static void command_line_handler (char *rl); |
| 50 | static void change_line_handler (void); |
| 51 | static void command_handler (char *command); |
| 52 | static char *top_level_prompt (void); |
| 53 | |
| 54 | /* Signal handlers. */ |
| 55 | #ifdef SIGQUIT |
| 56 | static void handle_sigquit (int sig); |
| 57 | #endif |
| 58 | #ifdef SIGHUP |
| 59 | static void handle_sighup (int sig); |
| 60 | #endif |
| 61 | static void handle_sigfpe (int sig); |
| 62 | |
| 63 | /* Functions to be invoked by the event loop in response to |
| 64 | signals. */ |
| 65 | #if defined (SIGQUIT) || defined (SIGHUP) |
| 66 | static void async_do_nothing (gdb_client_data); |
| 67 | #endif |
| 68 | #ifdef SIGHUP |
| 69 | static void async_disconnect (gdb_client_data); |
| 70 | #endif |
| 71 | static void async_float_handler (gdb_client_data); |
| 72 | #ifdef STOP_SIGNAL |
| 73 | static void async_stop_sig (gdb_client_data); |
| 74 | #endif |
| 75 | |
| 76 | /* Readline offers an alternate interface, via callback |
| 77 | functions. These are all included in the file callback.c in the |
| 78 | readline distribution. This file provides (mainly) a function, which |
| 79 | the event loop uses as callback (i.e. event handler) whenever an event |
| 80 | is detected on the standard input file descriptor. |
| 81 | readline_callback_read_char is called (by the GDB event loop) whenever |
| 82 | there is a new character ready on the input stream. This function |
| 83 | incrementally builds a buffer internal to readline where it |
| 84 | accumulates the line read up to the point of invocation. In the |
| 85 | special case in which the character read is newline, the function |
| 86 | invokes a GDB supplied callback routine, which does the processing of |
| 87 | a full command line. This latter routine is the asynchronous analog |
| 88 | of the old command_line_input in gdb. Instead of invoking (and waiting |
| 89 | for) readline to read the command line and pass it back to |
| 90 | command_loop for processing, the new command_line_handler function has |
| 91 | the command line already available as its parameter. INPUT_HANDLER is |
| 92 | to be set to the function that readline will invoke when a complete |
| 93 | line of input is ready. CALL_READLINE is to be set to the function |
| 94 | that readline offers as callback to the event_loop. */ |
| 95 | |
| 96 | void (*input_handler) (char *); |
| 97 | void (*call_readline) (gdb_client_data); |
| 98 | |
| 99 | /* Important variables for the event loop. */ |
| 100 | |
| 101 | /* This is used to determine if GDB is using the readline library or |
| 102 | its own simplified form of readline. It is used by the asynchronous |
| 103 | form of the set editing command. |
| 104 | ezannoni: as of 1999-04-29 I expect that this |
| 105 | variable will not be used after gdb is changed to use the event |
| 106 | loop as default engine, and event-top.c is merged into top.c. */ |
| 107 | int async_command_editing_p; |
| 108 | |
| 109 | /* This is the annotation suffix that will be used when the |
| 110 | annotation_level is 2. */ |
| 111 | char *async_annotation_suffix; |
| 112 | |
| 113 | /* This is used to display the notification of the completion of an |
| 114 | asynchronous execution command. */ |
| 115 | int exec_done_display_p = 0; |
| 116 | |
| 117 | /* This is the file descriptor for the input stream that GDB uses to |
| 118 | read commands from. */ |
| 119 | int input_fd; |
| 120 | |
| 121 | /* Signal handling variables. */ |
| 122 | /* Each of these is a pointer to a function that the event loop will |
| 123 | invoke if the corresponding signal has received. The real signal |
| 124 | handlers mark these functions as ready to be executed and the event |
| 125 | loop, in a later iteration, calls them. See the function |
| 126 | invoke_async_signal_handler. */ |
| 127 | static struct async_signal_handler *sigint_token; |
| 128 | #ifdef SIGHUP |
| 129 | static struct async_signal_handler *sighup_token; |
| 130 | #endif |
| 131 | #ifdef SIGQUIT |
| 132 | static struct async_signal_handler *sigquit_token; |
| 133 | #endif |
| 134 | static struct async_signal_handler *sigfpe_token; |
| 135 | #ifdef STOP_SIGNAL |
| 136 | static struct async_signal_handler *sigtstp_token; |
| 137 | #endif |
| 138 | |
| 139 | /* Structure to save a partially entered command. This is used when |
| 140 | the user types '\' at the end of a command line. This is necessary |
| 141 | because each line of input is handled by a different call to |
| 142 | command_line_handler, and normally there is no state retained |
| 143 | between different calls. */ |
| 144 | static int more_to_come = 0; |
| 145 | |
| 146 | struct readline_input_state |
| 147 | { |
| 148 | char *linebuffer; |
| 149 | char *linebuffer_ptr; |
| 150 | } |
| 151 | readline_input_state; |
| 152 | |
| 153 | /* This hook is called by rl_callback_read_char_wrapper after each |
| 154 | character is processed. */ |
| 155 | void (*after_char_processing_hook) (void); |
| 156 | \f |
| 157 | |
| 158 | /* Wrapper function for calling into the readline library. The event |
| 159 | loop expects the callback function to have a paramter, while |
| 160 | readline expects none. */ |
| 161 | static void |
| 162 | rl_callback_read_char_wrapper (gdb_client_data client_data) |
| 163 | { |
| 164 | rl_callback_read_char (); |
| 165 | if (after_char_processing_hook) |
| 166 | (*after_char_processing_hook) (); |
| 167 | } |
| 168 | |
| 169 | /* Initialize all the necessary variables, start the event loop, |
| 170 | register readline, and stdin, start the loop. */ |
| 171 | void |
| 172 | cli_command_loop (void) |
| 173 | { |
| 174 | display_gdb_prompt (0); |
| 175 | |
| 176 | /* Now it's time to start the event loop. */ |
| 177 | start_event_loop (); |
| 178 | } |
| 179 | |
| 180 | /* Change the function to be invoked every time there is a character |
| 181 | ready on stdin. This is used when the user sets the editing off, |
| 182 | therefore bypassing readline, and letting gdb handle the input |
| 183 | itself, via gdb_readline2. Also it is used in the opposite case in |
| 184 | which the user sets editing on again, by restoring readline |
| 185 | handling of the input. */ |
| 186 | static void |
| 187 | change_line_handler (void) |
| 188 | { |
| 189 | /* NOTE: this operates on input_fd, not instream. If we are reading |
| 190 | commands from a file, instream will point to the file. However in |
| 191 | async mode, we always read commands from a file with editing |
| 192 | off. This means that the 'set editing on/off' will have effect |
| 193 | only on the interactive session. */ |
| 194 | |
| 195 | if (async_command_editing_p) |
| 196 | { |
| 197 | /* Turn on editing by using readline. */ |
| 198 | call_readline = rl_callback_read_char_wrapper; |
| 199 | input_handler = command_line_handler; |
| 200 | } |
| 201 | else |
| 202 | { |
| 203 | /* Turn off editing by using gdb_readline2. */ |
| 204 | rl_callback_handler_remove (); |
| 205 | call_readline = gdb_readline2; |
| 206 | |
| 207 | /* Set up the command handler as well, in case we are called as |
| 208 | first thing from .gdbinit. */ |
| 209 | input_handler = command_line_handler; |
| 210 | } |
| 211 | } |
| 212 | |
| 213 | /* Displays the prompt. If the argument NEW_PROMPT is NULL, the |
| 214 | prompt that is displayed is the current top level prompt. |
| 215 | Otherwise, it displays whatever NEW_PROMPT is as a local/secondary |
| 216 | prompt. |
| 217 | |
| 218 | This is used after each gdb command has completed, and in the |
| 219 | following cases: |
| 220 | |
| 221 | 1. When the user enters a command line which is ended by '\' |
| 222 | indicating that the command will continue on the next line. In |
| 223 | that case the prompt that is displayed is the empty string. |
| 224 | |
| 225 | 2. When the user is entering 'commands' for a breakpoint, or |
| 226 | actions for a tracepoint. In this case the prompt will be '>' |
| 227 | |
| 228 | 3. On prompting for pagination. */ |
| 229 | |
| 230 | void |
| 231 | display_gdb_prompt (char *new_prompt) |
| 232 | { |
| 233 | char *actual_gdb_prompt = NULL; |
| 234 | struct cleanup *old_chain; |
| 235 | |
| 236 | annotate_display_prompt (); |
| 237 | |
| 238 | /* Reset the nesting depth used when trace-commands is set. */ |
| 239 | reset_command_nest_depth (); |
| 240 | |
| 241 | /* Each interpreter has its own rules on displaying the command |
| 242 | prompt. */ |
| 243 | if (!current_interp_display_prompt_p ()) |
| 244 | return; |
| 245 | |
| 246 | old_chain = make_cleanup (free_current_contents, &actual_gdb_prompt); |
| 247 | |
| 248 | /* Do not call the python hook on an explicit prompt change as |
| 249 | passed to this function, as this forms a secondary/local prompt, |
| 250 | IE, displayed but not set. */ |
| 251 | if (! new_prompt) |
| 252 | { |
| 253 | if (sync_execution) |
| 254 | { |
| 255 | /* This is to trick readline into not trying to display the |
| 256 | prompt. Even though we display the prompt using this |
| 257 | function, readline still tries to do its own display if |
| 258 | we don't call rl_callback_handler_install and |
| 259 | rl_callback_handler_remove (which readline detects |
| 260 | because a global variable is not set). If readline did |
| 261 | that, it could mess up gdb signal handlers for SIGINT. |
| 262 | Readline assumes that between calls to rl_set_signals and |
| 263 | rl_clear_signals gdb doesn't do anything with the signal |
| 264 | handlers. Well, that's not the case, because when the |
| 265 | target executes we change the SIGINT signal handler. If |
| 266 | we allowed readline to display the prompt, the signal |
| 267 | handler change would happen exactly between the calls to |
| 268 | the above two functions. Calling |
| 269 | rl_callback_handler_remove(), does the job. */ |
| 270 | |
| 271 | rl_callback_handler_remove (); |
| 272 | do_cleanups (old_chain); |
| 273 | return; |
| 274 | } |
| 275 | else |
| 276 | { |
| 277 | /* Display the top level prompt. */ |
| 278 | actual_gdb_prompt = top_level_prompt (); |
| 279 | } |
| 280 | } |
| 281 | else |
| 282 | actual_gdb_prompt = xstrdup (new_prompt); |
| 283 | |
| 284 | if (async_command_editing_p) |
| 285 | { |
| 286 | rl_callback_handler_remove (); |
| 287 | rl_callback_handler_install (actual_gdb_prompt, input_handler); |
| 288 | } |
| 289 | /* new_prompt at this point can be the top of the stack or the one |
| 290 | passed in. It can't be NULL. */ |
| 291 | else |
| 292 | { |
| 293 | /* Don't use a _filtered function here. It causes the assumed |
| 294 | character position to be off, since the newline we read from |
| 295 | the user is not accounted for. */ |
| 296 | fputs_unfiltered (actual_gdb_prompt, gdb_stdout); |
| 297 | gdb_flush (gdb_stdout); |
| 298 | } |
| 299 | |
| 300 | do_cleanups (old_chain); |
| 301 | } |
| 302 | |
| 303 | /* Return the top level prompt, as specified by "set prompt", possibly |
| 304 | overriden by the python gdb.prompt_hook hook, and then composed |
| 305 | with the prompt prefix and suffix (annotations). The caller is |
| 306 | responsible for freeing the returned string. */ |
| 307 | |
| 308 | static char * |
| 309 | top_level_prompt (void) |
| 310 | { |
| 311 | char *prefix; |
| 312 | char *prompt = NULL; |
| 313 | char *suffix; |
| 314 | char *composed_prompt; |
| 315 | size_t prompt_length; |
| 316 | |
| 317 | /* Give observers a chance of changing the prompt. E.g., the python |
| 318 | `gdb.prompt_hook' is installed as an observer. */ |
| 319 | observer_notify_before_prompt (get_prompt ()); |
| 320 | |
| 321 | prompt = xstrdup (get_prompt ()); |
| 322 | |
| 323 | if (annotation_level >= 2) |
| 324 | { |
| 325 | /* Prefix needs to have new line at end. */ |
| 326 | prefix = (char *) alloca (strlen (async_annotation_suffix) + 10); |
| 327 | strcpy (prefix, "\n\032\032pre-"); |
| 328 | strcat (prefix, async_annotation_suffix); |
| 329 | strcat (prefix, "\n"); |
| 330 | |
| 331 | /* Suffix needs to have a new line at end and \032 \032 at |
| 332 | beginning. */ |
| 333 | suffix = (char *) alloca (strlen (async_annotation_suffix) + 6); |
| 334 | strcpy (suffix, "\n\032\032"); |
| 335 | strcat (suffix, async_annotation_suffix); |
| 336 | strcat (suffix, "\n"); |
| 337 | } |
| 338 | else |
| 339 | { |
| 340 | prefix = ""; |
| 341 | suffix = ""; |
| 342 | } |
| 343 | |
| 344 | prompt_length = strlen (prefix) + strlen (prompt) + strlen (suffix); |
| 345 | composed_prompt = xmalloc (prompt_length + 1); |
| 346 | |
| 347 | strcpy (composed_prompt, prefix); |
| 348 | strcat (composed_prompt, prompt); |
| 349 | strcat (composed_prompt, suffix); |
| 350 | |
| 351 | xfree (prompt); |
| 352 | |
| 353 | return composed_prompt; |
| 354 | } |
| 355 | |
| 356 | /* When there is an event ready on the stdin file desriptor, instead |
| 357 | of calling readline directly throught the callback function, or |
| 358 | instead of calling gdb_readline2, give gdb a chance to detect |
| 359 | errors and do something. */ |
| 360 | void |
| 361 | stdin_event_handler (int error, gdb_client_data client_data) |
| 362 | { |
| 363 | if (error) |
| 364 | { |
| 365 | printf_unfiltered (_("error detected on stdin\n")); |
| 366 | delete_file_handler (input_fd); |
| 367 | discard_all_continuations (); |
| 368 | discard_all_intermediate_continuations (); |
| 369 | /* If stdin died, we may as well kill gdb. */ |
| 370 | quit_command ((char *) 0, stdin == instream); |
| 371 | } |
| 372 | else |
| 373 | (*call_readline) (client_data); |
| 374 | } |
| 375 | |
| 376 | /* Re-enable stdin after the end of an execution command in |
| 377 | synchronous mode, or after an error from the target, and we aborted |
| 378 | the exec operation. */ |
| 379 | |
| 380 | void |
| 381 | async_enable_stdin (void) |
| 382 | { |
| 383 | if (sync_execution) |
| 384 | { |
| 385 | /* See NOTE in async_disable_stdin(). */ |
| 386 | /* FIXME: cagney/1999-09-27: Call this before clearing |
| 387 | sync_execution. Current target_terminal_ours() implementations |
| 388 | check for sync_execution before switching the terminal. */ |
| 389 | target_terminal_ours (); |
| 390 | sync_execution = 0; |
| 391 | } |
| 392 | } |
| 393 | |
| 394 | /* Disable reads from stdin (the console) marking the command as |
| 395 | synchronous. */ |
| 396 | |
| 397 | void |
| 398 | async_disable_stdin (void) |
| 399 | { |
| 400 | sync_execution = 1; |
| 401 | } |
| 402 | \f |
| 403 | |
| 404 | /* Handles a gdb command. This function is called by |
| 405 | command_line_handler, which has processed one or more input lines |
| 406 | into COMMAND. */ |
| 407 | /* NOTE: 1999-04-30 This is the asynchronous version of the command_loop |
| 408 | function. The command_loop function will be obsolete when we |
| 409 | switch to use the event loop at every execution of gdb. */ |
| 410 | static void |
| 411 | command_handler (char *command) |
| 412 | { |
| 413 | int stdin_is_tty = ISATTY (stdin); |
| 414 | struct cleanup *stat_chain; |
| 415 | |
| 416 | clear_quit_flag (); |
| 417 | if (instream == stdin && stdin_is_tty) |
| 418 | reinitialize_more_filter (); |
| 419 | |
| 420 | /* If readline returned a NULL command, it means that the connection |
| 421 | with the terminal is gone. This happens at the end of a |
| 422 | testsuite run, after Expect has hung up but GDB is still alive. |
| 423 | In such a case, we just quit gdb killing the inferior program |
| 424 | too. */ |
| 425 | if (command == 0) |
| 426 | { |
| 427 | printf_unfiltered ("quit\n"); |
| 428 | execute_command ("quit", stdin == instream); |
| 429 | } |
| 430 | |
| 431 | stat_chain = make_command_stats_cleanup (1); |
| 432 | |
| 433 | execute_command (command, instream == stdin); |
| 434 | |
| 435 | /* Do any commands attached to breakpoint we stopped at. */ |
| 436 | bpstat_do_actions (); |
| 437 | |
| 438 | do_cleanups (stat_chain); |
| 439 | } |
| 440 | |
| 441 | /* Handle a complete line of input. This is called by the callback |
| 442 | mechanism within the readline library. Deal with incomplete |
| 443 | commands as well, by saving the partial input in a global |
| 444 | buffer. */ |
| 445 | |
| 446 | /* NOTE: 1999-04-30 This is the asynchronous version of the |
| 447 | command_line_input function; command_line_input will become |
| 448 | obsolete once we use the event loop as the default mechanism in |
| 449 | GDB. */ |
| 450 | static void |
| 451 | command_line_handler (char *rl) |
| 452 | { |
| 453 | static char *linebuffer = 0; |
| 454 | static unsigned linelength = 0; |
| 455 | char *p; |
| 456 | char *p1; |
| 457 | char *nline; |
| 458 | int repeat = (instream == stdin); |
| 459 | |
| 460 | if (annotation_level > 1 && instream == stdin) |
| 461 | { |
| 462 | printf_unfiltered (("\n\032\032post-")); |
| 463 | puts_unfiltered (async_annotation_suffix); |
| 464 | printf_unfiltered (("\n")); |
| 465 | } |
| 466 | |
| 467 | if (linebuffer == 0) |
| 468 | { |
| 469 | linelength = 80; |
| 470 | linebuffer = (char *) xmalloc (linelength); |
| 471 | } |
| 472 | |
| 473 | p = linebuffer; |
| 474 | |
| 475 | if (more_to_come) |
| 476 | { |
| 477 | strcpy (linebuffer, readline_input_state.linebuffer); |
| 478 | p = readline_input_state.linebuffer_ptr; |
| 479 | xfree (readline_input_state.linebuffer); |
| 480 | more_to_come = 0; |
| 481 | } |
| 482 | |
| 483 | #ifdef STOP_SIGNAL |
| 484 | if (job_control) |
| 485 | signal (STOP_SIGNAL, handle_stop_sig); |
| 486 | #endif |
| 487 | |
| 488 | /* Make sure that all output has been output. Some machines may let |
| 489 | you get away with leaving out some of the gdb_flush, but not |
| 490 | all. */ |
| 491 | wrap_here (""); |
| 492 | gdb_flush (gdb_stdout); |
| 493 | gdb_flush (gdb_stderr); |
| 494 | |
| 495 | if (source_file_name != NULL) |
| 496 | ++source_line_number; |
| 497 | |
| 498 | /* If we are in this case, then command_handler will call quit |
| 499 | and exit from gdb. */ |
| 500 | if (!rl || rl == (char *) EOF) |
| 501 | { |
| 502 | command_handler (0); |
| 503 | return; /* Lint. */ |
| 504 | } |
| 505 | if (strlen (rl) + 1 + (p - linebuffer) > linelength) |
| 506 | { |
| 507 | linelength = strlen (rl) + 1 + (p - linebuffer); |
| 508 | nline = (char *) xrealloc (linebuffer, linelength); |
| 509 | p += nline - linebuffer; |
| 510 | linebuffer = nline; |
| 511 | } |
| 512 | p1 = rl; |
| 513 | /* Copy line. Don't copy null at end. (Leaves line alone |
| 514 | if this was just a newline). */ |
| 515 | while (*p1) |
| 516 | *p++ = *p1++; |
| 517 | |
| 518 | xfree (rl); /* Allocated in readline. */ |
| 519 | |
| 520 | if (p > linebuffer && *(p - 1) == '\\') |
| 521 | { |
| 522 | *p = '\0'; |
| 523 | p--; /* Put on top of '\'. */ |
| 524 | |
| 525 | readline_input_state.linebuffer = xstrdup (linebuffer); |
| 526 | readline_input_state.linebuffer_ptr = p; |
| 527 | |
| 528 | /* We will not invoke a execute_command if there is more |
| 529 | input expected to complete the command. So, we need to |
| 530 | print an empty prompt here. */ |
| 531 | more_to_come = 1; |
| 532 | display_gdb_prompt (""); |
| 533 | return; |
| 534 | } |
| 535 | |
| 536 | #ifdef STOP_SIGNAL |
| 537 | if (job_control) |
| 538 | signal (STOP_SIGNAL, SIG_DFL); |
| 539 | #endif |
| 540 | |
| 541 | #define SERVER_COMMAND_LENGTH 7 |
| 542 | server_command = |
| 543 | (p - linebuffer > SERVER_COMMAND_LENGTH) |
| 544 | && strncmp (linebuffer, "server ", SERVER_COMMAND_LENGTH) == 0; |
| 545 | if (server_command) |
| 546 | { |
| 547 | /* Note that we don't set `line'. Between this and the check in |
| 548 | dont_repeat, this insures that repeating will still do the |
| 549 | right thing. */ |
| 550 | *p = '\0'; |
| 551 | command_handler (linebuffer + SERVER_COMMAND_LENGTH); |
| 552 | display_gdb_prompt (0); |
| 553 | return; |
| 554 | } |
| 555 | |
| 556 | /* Do history expansion if that is wished. */ |
| 557 | if (history_expansion_p && instream == stdin |
| 558 | && ISATTY (instream)) |
| 559 | { |
| 560 | char *history_value; |
| 561 | int expanded; |
| 562 | |
| 563 | *p = '\0'; /* Insert null now. */ |
| 564 | expanded = history_expand (linebuffer, &history_value); |
| 565 | if (expanded) |
| 566 | { |
| 567 | /* Print the changes. */ |
| 568 | printf_unfiltered ("%s\n", history_value); |
| 569 | |
| 570 | /* If there was an error, call this function again. */ |
| 571 | if (expanded < 0) |
| 572 | { |
| 573 | xfree (history_value); |
| 574 | return; |
| 575 | } |
| 576 | if (strlen (history_value) > linelength) |
| 577 | { |
| 578 | linelength = strlen (history_value) + 1; |
| 579 | linebuffer = (char *) xrealloc (linebuffer, linelength); |
| 580 | } |
| 581 | strcpy (linebuffer, history_value); |
| 582 | p = linebuffer + strlen (linebuffer); |
| 583 | } |
| 584 | xfree (history_value); |
| 585 | } |
| 586 | |
| 587 | /* If we just got an empty line, and that is supposed to repeat the |
| 588 | previous command, return the value in the global buffer. */ |
| 589 | if (repeat && p == linebuffer && *p != '\\') |
| 590 | { |
| 591 | command_handler (saved_command_line); |
| 592 | display_gdb_prompt (0); |
| 593 | return; |
| 594 | } |
| 595 | |
| 596 | for (p1 = linebuffer; *p1 == ' ' || *p1 == '\t'; p1++); |
| 597 | if (repeat && !*p1) |
| 598 | { |
| 599 | command_handler (saved_command_line); |
| 600 | display_gdb_prompt (0); |
| 601 | return; |
| 602 | } |
| 603 | |
| 604 | *p = 0; |
| 605 | |
| 606 | /* Add line to history if appropriate. */ |
| 607 | if (instream == stdin |
| 608 | && ISATTY (stdin) && *linebuffer) |
| 609 | add_history (linebuffer); |
| 610 | |
| 611 | /* Note: lines consisting solely of comments are added to the command |
| 612 | history. This is useful when you type a command, and then |
| 613 | realize you don't want to execute it quite yet. You can comment |
| 614 | out the command and then later fetch it from the value history |
| 615 | and remove the '#'. The kill ring is probably better, but some |
| 616 | people are in the habit of commenting things out. */ |
| 617 | if (*p1 == '#') |
| 618 | *p1 = '\0'; /* Found a comment. */ |
| 619 | |
| 620 | /* Save into global buffer if appropriate. */ |
| 621 | if (repeat) |
| 622 | { |
| 623 | if (linelength > saved_command_line_size) |
| 624 | { |
| 625 | saved_command_line = xrealloc (saved_command_line, linelength); |
| 626 | saved_command_line_size = linelength; |
| 627 | } |
| 628 | strcpy (saved_command_line, linebuffer); |
| 629 | if (!more_to_come) |
| 630 | { |
| 631 | command_handler (saved_command_line); |
| 632 | display_gdb_prompt (0); |
| 633 | } |
| 634 | return; |
| 635 | } |
| 636 | |
| 637 | command_handler (linebuffer); |
| 638 | display_gdb_prompt (0); |
| 639 | return; |
| 640 | } |
| 641 | |
| 642 | /* Does reading of input from terminal w/o the editing features |
| 643 | provided by the readline library. */ |
| 644 | |
| 645 | /* NOTE: 1999-04-30 Asynchronous version of gdb_readline; gdb_readline |
| 646 | will become obsolete when the event loop is made the default |
| 647 | execution for gdb. */ |
| 648 | void |
| 649 | gdb_readline2 (gdb_client_data client_data) |
| 650 | { |
| 651 | int c; |
| 652 | char *result; |
| 653 | int input_index = 0; |
| 654 | int result_size = 80; |
| 655 | static int done_once = 0; |
| 656 | |
| 657 | /* Unbuffer the input stream, so that, later on, the calls to fgetc |
| 658 | fetch only one char at the time from the stream. The fgetc's will |
| 659 | get up to the first newline, but there may be more chars in the |
| 660 | stream after '\n'. If we buffer the input and fgetc drains the |
| 661 | stream, getting stuff beyond the newline as well, a select, done |
| 662 | afterwards will not trigger. */ |
| 663 | if (!done_once && !ISATTY (instream)) |
| 664 | { |
| 665 | setbuf (instream, NULL); |
| 666 | done_once = 1; |
| 667 | } |
| 668 | |
| 669 | result = (char *) xmalloc (result_size); |
| 670 | |
| 671 | /* We still need the while loop here, even though it would seem |
| 672 | obvious to invoke gdb_readline2 at every character entered. If |
| 673 | not using the readline library, the terminal is in cooked mode, |
| 674 | which sends the characters all at once. Poll will notice that the |
| 675 | input fd has changed state only after enter is pressed. At this |
| 676 | point we still need to fetch all the chars entered. */ |
| 677 | |
| 678 | while (1) |
| 679 | { |
| 680 | /* Read from stdin if we are executing a user defined command. |
| 681 | This is the right thing for prompt_for_continue, at least. */ |
| 682 | c = fgetc (instream ? instream : stdin); |
| 683 | |
| 684 | if (c == EOF) |
| 685 | { |
| 686 | if (input_index > 0) |
| 687 | /* The last line does not end with a newline. Return it, |
| 688 | and if we are called again fgetc will still return EOF |
| 689 | and we'll return NULL then. */ |
| 690 | break; |
| 691 | xfree (result); |
| 692 | (*input_handler) (0); |
| 693 | return; |
| 694 | } |
| 695 | |
| 696 | if (c == '\n') |
| 697 | { |
| 698 | if (input_index > 0 && result[input_index - 1] == '\r') |
| 699 | input_index--; |
| 700 | break; |
| 701 | } |
| 702 | |
| 703 | result[input_index++] = c; |
| 704 | while (input_index >= result_size) |
| 705 | { |
| 706 | result_size *= 2; |
| 707 | result = (char *) xrealloc (result, result_size); |
| 708 | } |
| 709 | } |
| 710 | |
| 711 | result[input_index++] = '\0'; |
| 712 | (*input_handler) (result); |
| 713 | } |
| 714 | \f |
| 715 | |
| 716 | /* Initialization of signal handlers and tokens. There is a function |
| 717 | handle_sig* for each of the signals GDB cares about. Specifically: |
| 718 | SIGINT, SIGFPE, SIGQUIT, SIGTSTP, SIGHUP, SIGWINCH. These |
| 719 | functions are the actual signal handlers associated to the signals |
| 720 | via calls to signal(). The only job for these functions is to |
| 721 | enqueue the appropriate event/procedure with the event loop. Such |
| 722 | procedures are the old signal handlers. The event loop will take |
| 723 | care of invoking the queued procedures to perform the usual tasks |
| 724 | associated with the reception of the signal. */ |
| 725 | /* NOTE: 1999-04-30 This is the asynchronous version of init_signals. |
| 726 | init_signals will become obsolete as we move to have to event loop |
| 727 | as the default for gdb. */ |
| 728 | void |
| 729 | async_init_signals (void) |
| 730 | { |
| 731 | signal (SIGINT, handle_sigint); |
| 732 | sigint_token = |
| 733 | create_async_signal_handler (async_request_quit, NULL); |
| 734 | signal (SIGTERM, handle_sigterm); |
| 735 | |
| 736 | /* If SIGTRAP was set to SIG_IGN, then the SIG_IGN will get passed |
| 737 | to the inferior and breakpoints will be ignored. */ |
| 738 | #ifdef SIGTRAP |
| 739 | signal (SIGTRAP, SIG_DFL); |
| 740 | #endif |
| 741 | |
| 742 | #ifdef SIGQUIT |
| 743 | /* If we initialize SIGQUIT to SIG_IGN, then the SIG_IGN will get |
| 744 | passed to the inferior, which we don't want. It would be |
| 745 | possible to do a "signal (SIGQUIT, SIG_DFL)" after we fork, but |
| 746 | on BSD4.3 systems using vfork, that can affect the |
| 747 | GDB process as well as the inferior (the signal handling tables |
| 748 | might be in memory, shared between the two). Since we establish |
| 749 | a handler for SIGQUIT, when we call exec it will set the signal |
| 750 | to SIG_DFL for us. */ |
| 751 | signal (SIGQUIT, handle_sigquit); |
| 752 | sigquit_token = |
| 753 | create_async_signal_handler (async_do_nothing, NULL); |
| 754 | #endif |
| 755 | #ifdef SIGHUP |
| 756 | if (signal (SIGHUP, handle_sighup) != SIG_IGN) |
| 757 | sighup_token = |
| 758 | create_async_signal_handler (async_disconnect, NULL); |
| 759 | else |
| 760 | sighup_token = |
| 761 | create_async_signal_handler (async_do_nothing, NULL); |
| 762 | #endif |
| 763 | signal (SIGFPE, handle_sigfpe); |
| 764 | sigfpe_token = |
| 765 | create_async_signal_handler (async_float_handler, NULL); |
| 766 | |
| 767 | #ifdef STOP_SIGNAL |
| 768 | sigtstp_token = |
| 769 | create_async_signal_handler (async_stop_sig, NULL); |
| 770 | #endif |
| 771 | |
| 772 | } |
| 773 | |
| 774 | /* Tell the event loop what to do if SIGINT is received. |
| 775 | See event-signal.c. */ |
| 776 | void |
| 777 | handle_sigint (int sig) |
| 778 | { |
| 779 | signal (sig, handle_sigint); |
| 780 | |
| 781 | /* We could be running in a loop reading in symfiles or something so |
| 782 | it may be quite a while before we get back to the event loop. So |
| 783 | set quit_flag to 1 here. Then if QUIT is called before we get to |
| 784 | the event loop, we will unwind as expected. */ |
| 785 | |
| 786 | set_quit_flag (); |
| 787 | |
| 788 | /* If immediate_quit is set, we go ahead and process the SIGINT right |
| 789 | away, even if we usually would defer this to the event loop. The |
| 790 | assumption here is that it is safe to process ^C immediately if |
| 791 | immediate_quit is set. If we didn't, SIGINT would be really |
| 792 | processed only the next time through the event loop. To get to |
| 793 | that point, though, the command that we want to interrupt needs to |
| 794 | finish first, which is unacceptable. If immediate quit is not set, |
| 795 | we process SIGINT the next time through the loop, which is fine. */ |
| 796 | gdb_call_async_signal_handler (sigint_token, immediate_quit); |
| 797 | } |
| 798 | |
| 799 | /* Quit GDB if SIGTERM is received. |
| 800 | GDB would quit anyway, but this way it will clean up properly. */ |
| 801 | void |
| 802 | handle_sigterm (int sig) |
| 803 | { |
| 804 | signal (sig, handle_sigterm); |
| 805 | quit_force ((char *) 0, stdin == instream); |
| 806 | } |
| 807 | |
| 808 | /* Do the quit. All the checks have been done by the caller. */ |
| 809 | void |
| 810 | async_request_quit (gdb_client_data arg) |
| 811 | { |
| 812 | /* If the quit_flag has gotten reset back to 0 by the time we get |
| 813 | back here, that means that an exception was thrown to unwind the |
| 814 | current command before we got back to the event loop. So there |
| 815 | is no reason to call quit again here. */ |
| 816 | |
| 817 | if (check_quit_flag ()) |
| 818 | quit (); |
| 819 | } |
| 820 | |
| 821 | #ifdef SIGQUIT |
| 822 | /* Tell the event loop what to do if SIGQUIT is received. |
| 823 | See event-signal.c. */ |
| 824 | static void |
| 825 | handle_sigquit (int sig) |
| 826 | { |
| 827 | mark_async_signal_handler (sigquit_token); |
| 828 | signal (sig, handle_sigquit); |
| 829 | } |
| 830 | #endif |
| 831 | |
| 832 | #if defined (SIGQUIT) || defined (SIGHUP) |
| 833 | /* Called by the event loop in response to a SIGQUIT or an |
| 834 | ignored SIGHUP. */ |
| 835 | static void |
| 836 | async_do_nothing (gdb_client_data arg) |
| 837 | { |
| 838 | /* Empty function body. */ |
| 839 | } |
| 840 | #endif |
| 841 | |
| 842 | #ifdef SIGHUP |
| 843 | /* Tell the event loop what to do if SIGHUP is received. |
| 844 | See event-signal.c. */ |
| 845 | static void |
| 846 | handle_sighup (int sig) |
| 847 | { |
| 848 | mark_async_signal_handler (sighup_token); |
| 849 | signal (sig, handle_sighup); |
| 850 | } |
| 851 | |
| 852 | /* Called by the event loop to process a SIGHUP. */ |
| 853 | static void |
| 854 | async_disconnect (gdb_client_data arg) |
| 855 | { |
| 856 | volatile struct gdb_exception exception; |
| 857 | |
| 858 | TRY_CATCH (exception, RETURN_MASK_ALL) |
| 859 | { |
| 860 | quit_cover (); |
| 861 | } |
| 862 | |
| 863 | if (exception.reason < 0) |
| 864 | { |
| 865 | fputs_filtered ("Could not kill the program being debugged", |
| 866 | gdb_stderr); |
| 867 | exception_print (gdb_stderr, exception); |
| 868 | } |
| 869 | |
| 870 | TRY_CATCH (exception, RETURN_MASK_ALL) |
| 871 | { |
| 872 | pop_all_targets (); |
| 873 | } |
| 874 | |
| 875 | signal (SIGHUP, SIG_DFL); /*FIXME: ??????????? */ |
| 876 | raise (SIGHUP); |
| 877 | } |
| 878 | #endif |
| 879 | |
| 880 | #ifdef STOP_SIGNAL |
| 881 | void |
| 882 | handle_stop_sig (int sig) |
| 883 | { |
| 884 | mark_async_signal_handler (sigtstp_token); |
| 885 | signal (sig, handle_stop_sig); |
| 886 | } |
| 887 | |
| 888 | static void |
| 889 | async_stop_sig (gdb_client_data arg) |
| 890 | { |
| 891 | char *prompt = get_prompt (); |
| 892 | |
| 893 | #if STOP_SIGNAL == SIGTSTP |
| 894 | signal (SIGTSTP, SIG_DFL); |
| 895 | #if HAVE_SIGPROCMASK |
| 896 | { |
| 897 | sigset_t zero; |
| 898 | |
| 899 | sigemptyset (&zero); |
| 900 | sigprocmask (SIG_SETMASK, &zero, 0); |
| 901 | } |
| 902 | #elif HAVE_SIGSETMASK |
| 903 | sigsetmask (0); |
| 904 | #endif |
| 905 | raise (SIGTSTP); |
| 906 | signal (SIGTSTP, handle_stop_sig); |
| 907 | #else |
| 908 | signal (STOP_SIGNAL, handle_stop_sig); |
| 909 | #endif |
| 910 | printf_unfiltered ("%s", prompt); |
| 911 | gdb_flush (gdb_stdout); |
| 912 | |
| 913 | /* Forget about any previous command -- null line now will do |
| 914 | nothing. */ |
| 915 | dont_repeat (); |
| 916 | } |
| 917 | #endif /* STOP_SIGNAL */ |
| 918 | |
| 919 | /* Tell the event loop what to do if SIGFPE is received. |
| 920 | See event-signal.c. */ |
| 921 | static void |
| 922 | handle_sigfpe (int sig) |
| 923 | { |
| 924 | mark_async_signal_handler (sigfpe_token); |
| 925 | signal (sig, handle_sigfpe); |
| 926 | } |
| 927 | |
| 928 | /* Event loop will call this functin to process a SIGFPE. */ |
| 929 | static void |
| 930 | async_float_handler (gdb_client_data arg) |
| 931 | { |
| 932 | /* This message is based on ANSI C, section 4.7. Note that integer |
| 933 | divide by zero causes this, so "float" is a misnomer. */ |
| 934 | error (_("Erroneous arithmetic operation.")); |
| 935 | } |
| 936 | \f |
| 937 | |
| 938 | /* Called by do_setshow_command. */ |
| 939 | void |
| 940 | set_async_editing_command (char *args, int from_tty, |
| 941 | struct cmd_list_element *c) |
| 942 | { |
| 943 | change_line_handler (); |
| 944 | } |
| 945 | |
| 946 | /* Set things up for readline to be invoked via the alternate |
| 947 | interface, i.e. via a callback function (rl_callback_read_char), |
| 948 | and hook up instream to the event loop. */ |
| 949 | void |
| 950 | gdb_setup_readline (void) |
| 951 | { |
| 952 | /* This function is a noop for the sync case. The assumption is |
| 953 | that the sync setup is ALL done in gdb_init, and we would only |
| 954 | mess it up here. The sync stuff should really go away over |
| 955 | time. */ |
| 956 | if (!batch_silent) |
| 957 | gdb_stdout = stdio_fileopen (stdout); |
| 958 | gdb_stderr = stderr_fileopen (); |
| 959 | gdb_stdlog = gdb_stderr; /* for moment */ |
| 960 | gdb_stdtarg = gdb_stderr; /* for moment */ |
| 961 | gdb_stdtargerr = gdb_stderr; /* for moment */ |
| 962 | |
| 963 | /* If the input stream is connected to a terminal, turn on |
| 964 | editing. */ |
| 965 | if (ISATTY (instream)) |
| 966 | { |
| 967 | /* Tell gdb that we will be using the readline library. This |
| 968 | could be overwritten by a command in .gdbinit like 'set |
| 969 | editing on' or 'off'. */ |
| 970 | async_command_editing_p = 1; |
| 971 | |
| 972 | /* When a character is detected on instream by select or poll, |
| 973 | readline will be invoked via this callback function. */ |
| 974 | call_readline = rl_callback_read_char_wrapper; |
| 975 | } |
| 976 | else |
| 977 | { |
| 978 | async_command_editing_p = 0; |
| 979 | call_readline = gdb_readline2; |
| 980 | } |
| 981 | |
| 982 | /* When readline has read an end-of-line character, it passes the |
| 983 | complete line to gdb for processing; command_line_handler is the |
| 984 | function that does this. */ |
| 985 | input_handler = command_line_handler; |
| 986 | |
| 987 | /* Tell readline to use the same input stream that gdb uses. */ |
| 988 | rl_instream = instream; |
| 989 | |
| 990 | /* Get a file descriptor for the input stream, so that we can |
| 991 | register it with the event loop. */ |
| 992 | input_fd = fileno (instream); |
| 993 | |
| 994 | /* Now we need to create the event sources for the input file |
| 995 | descriptor. */ |
| 996 | /* At this point in time, this is the only event source that we |
| 997 | register with the even loop. Another source is going to be the |
| 998 | target program (inferior), but that must be registered only when |
| 999 | it actually exists (I.e. after we say 'run' or after we connect |
| 1000 | to a remote target. */ |
| 1001 | add_file_handler (input_fd, stdin_event_handler, 0); |
| 1002 | } |
| 1003 | |
| 1004 | /* Disable command input through the standard CLI channels. Used in |
| 1005 | the suspend proc for interpreters that use the standard gdb readline |
| 1006 | interface, like the cli & the mi. */ |
| 1007 | void |
| 1008 | gdb_disable_readline (void) |
| 1009 | { |
| 1010 | /* FIXME - It is too heavyweight to delete and remake these every |
| 1011 | time you run an interpreter that needs readline. It is probably |
| 1012 | better to have the interpreters cache these, which in turn means |
| 1013 | that this needs to be moved into interpreter specific code. */ |
| 1014 | |
| 1015 | #if 0 |
| 1016 | ui_file_delete (gdb_stdout); |
| 1017 | ui_file_delete (gdb_stderr); |
| 1018 | gdb_stdlog = NULL; |
| 1019 | gdb_stdtarg = NULL; |
| 1020 | gdb_stdtargerr = NULL; |
| 1021 | #endif |
| 1022 | |
| 1023 | rl_callback_handler_remove (); |
| 1024 | delete_file_handler (input_fd); |
| 1025 | } |