| 1 | /* Top level stuff for GDB, the GNU debugger. |
| 2 | |
| 3 | Copyright (C) 1999-2020 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 "infrun.h" |
| 26 | #include "target.h" |
| 27 | #include "terminal.h" |
| 28 | #include "event-loop.h" |
| 29 | #include "event-top.h" |
| 30 | #include "interps.h" |
| 31 | #include <signal.h> |
| 32 | #include "cli/cli-script.h" /* for reset_command_nest_depth */ |
| 33 | #include "main.h" |
| 34 | #include "gdbthread.h" |
| 35 | #include "observable.h" |
| 36 | #include "continuations.h" |
| 37 | #include "gdbcmd.h" /* for dont_repeat() */ |
| 38 | #include "annotate.h" |
| 39 | #include "maint.h" |
| 40 | #include "gdbsupport/buffer.h" |
| 41 | #include "ser-event.h" |
| 42 | #include "gdb_select.h" |
| 43 | #include "gdbsupport/gdb-sigmask.h" |
| 44 | |
| 45 | /* readline include files. */ |
| 46 | #include "readline/readline.h" |
| 47 | #include "readline/history.h" |
| 48 | |
| 49 | /* readline defines this. */ |
| 50 | #undef savestring |
| 51 | |
| 52 | static std::string top_level_prompt (); |
| 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 SIGTSTP |
| 73 | static void async_sigtstp_handler (gdb_client_data); |
| 74 | #endif |
| 75 | static void async_sigterm_handler (gdb_client_data arg); |
| 76 | |
| 77 | /* Instead of invoking (and waiting for) readline to read the command |
| 78 | line and pass it back for processing, we use readline's alternate |
| 79 | interface, via callback functions, so that the event loop can react |
| 80 | to other event sources while we wait for input. */ |
| 81 | |
| 82 | /* Important variables for the event loop. */ |
| 83 | |
| 84 | /* This is used to determine if GDB is using the readline library or |
| 85 | its own simplified form of readline. It is used by the asynchronous |
| 86 | form of the set editing command. |
| 87 | ezannoni: as of 1999-04-29 I expect that this |
| 88 | variable will not be used after gdb is changed to use the event |
| 89 | loop as default engine, and event-top.c is merged into top.c. */ |
| 90 | bool set_editing_cmd_var; |
| 91 | |
| 92 | /* This is used to display the notification of the completion of an |
| 93 | asynchronous execution command. */ |
| 94 | bool exec_done_display_p = false; |
| 95 | |
| 96 | /* Used by the stdin event handler to compensate for missed stdin events. |
| 97 | Setting this to a non-zero value inside an stdin callback makes the callback |
| 98 | run again. */ |
| 99 | int call_stdin_event_handler_again_p; |
| 100 | |
| 101 | /* Signal handling variables. */ |
| 102 | /* Each of these is a pointer to a function that the event loop will |
| 103 | invoke if the corresponding signal has received. The real signal |
| 104 | handlers mark these functions as ready to be executed and the event |
| 105 | loop, in a later iteration, calls them. See the function |
| 106 | invoke_async_signal_handler. */ |
| 107 | static struct async_signal_handler *sigint_token; |
| 108 | #ifdef SIGHUP |
| 109 | static struct async_signal_handler *sighup_token; |
| 110 | #endif |
| 111 | #ifdef SIGQUIT |
| 112 | static struct async_signal_handler *sigquit_token; |
| 113 | #endif |
| 114 | static struct async_signal_handler *sigfpe_token; |
| 115 | #ifdef SIGTSTP |
| 116 | static struct async_signal_handler *sigtstp_token; |
| 117 | #endif |
| 118 | static struct async_signal_handler *async_sigterm_token; |
| 119 | |
| 120 | /* This hook is called by gdb_rl_callback_read_char_wrapper after each |
| 121 | character is processed. */ |
| 122 | void (*after_char_processing_hook) (void); |
| 123 | \f |
| 124 | |
| 125 | /* Wrapper function for calling into the readline library. This takes |
| 126 | care of a couple things: |
| 127 | |
| 128 | - The event loop expects the callback function to have a parameter, |
| 129 | while readline expects none. |
| 130 | |
| 131 | - Propagation of GDB exceptions/errors thrown from INPUT_HANDLER |
| 132 | across readline requires special handling. |
| 133 | |
| 134 | On the exceptions issue: |
| 135 | |
| 136 | DWARF-based unwinding cannot cross code built without -fexceptions. |
| 137 | Any exception that tries to propagate through such code will fail |
| 138 | and the result is a call to std::terminate. While some ABIs, such |
| 139 | as x86-64, require all code to be built with exception tables, |
| 140 | others don't. |
| 141 | |
| 142 | This is a problem when GDB calls some non-EH-aware C library code, |
| 143 | that calls into GDB again through a callback, and that GDB callback |
| 144 | code throws a C++ exception. Turns out this is exactly what |
| 145 | happens with GDB's readline callback. |
| 146 | |
| 147 | In such cases, we must catch and save any C++ exception that might |
| 148 | be thrown from the GDB callback before returning to the |
| 149 | non-EH-aware code. When the non-EH-aware function itself returns |
| 150 | back to GDB, we then rethrow the original C++ exception. |
| 151 | |
| 152 | In the readline case however, the right thing to do is to longjmp |
| 153 | out of the callback, rather than do a normal return -- there's no |
| 154 | way for the callback to return to readline an indication that an |
| 155 | error happened, so a normal return would have rl_callback_read_char |
| 156 | potentially continue processing further input, redisplay the |
| 157 | prompt, etc. Instead of raw setjmp/longjmp however, we use our |
| 158 | sjlj-based TRY/CATCH mechanism, which knows to handle multiple |
| 159 | levels of active setjmp/longjmp frames, needed in order to handle |
| 160 | the readline callback recursing, as happens with e.g., secondary |
| 161 | prompts / queries, through gdb_readline_wrapper. This must be |
| 162 | noexcept in order to avoid problems with mixing sjlj and |
| 163 | (sjlj-based) C++ exceptions. */ |
| 164 | |
| 165 | static struct gdb_exception |
| 166 | gdb_rl_callback_read_char_wrapper_noexcept () noexcept |
| 167 | { |
| 168 | struct gdb_exception gdb_expt; |
| 169 | |
| 170 | /* C++ exceptions can't normally be thrown across readline (unless |
| 171 | it is built with -fexceptions, but it won't by default on many |
| 172 | ABIs). So we instead wrap the readline call with a sjlj-based |
| 173 | TRY/CATCH, and rethrow the GDB exception once back in GDB. */ |
| 174 | TRY_SJLJ |
| 175 | { |
| 176 | rl_callback_read_char (); |
| 177 | if (after_char_processing_hook) |
| 178 | (*after_char_processing_hook) (); |
| 179 | } |
| 180 | CATCH_SJLJ (ex, RETURN_MASK_ALL) |
| 181 | { |
| 182 | gdb_expt = std::move (ex); |
| 183 | } |
| 184 | END_CATCH_SJLJ |
| 185 | |
| 186 | return gdb_expt; |
| 187 | } |
| 188 | |
| 189 | static void |
| 190 | gdb_rl_callback_read_char_wrapper (gdb_client_data client_data) |
| 191 | { |
| 192 | struct gdb_exception gdb_expt |
| 193 | = gdb_rl_callback_read_char_wrapper_noexcept (); |
| 194 | |
| 195 | /* Rethrow using the normal EH mechanism. */ |
| 196 | if (gdb_expt.reason < 0) |
| 197 | throw_exception (std::move (gdb_expt)); |
| 198 | } |
| 199 | |
| 200 | /* GDB's readline callback handler. Calls the current INPUT_HANDLER, |
| 201 | and propagates GDB exceptions/errors thrown from INPUT_HANDLER back |
| 202 | across readline. See gdb_rl_callback_read_char_wrapper. This must |
| 203 | be noexcept in order to avoid problems with mixing sjlj and |
| 204 | (sjlj-based) C++ exceptions. */ |
| 205 | |
| 206 | static void |
| 207 | gdb_rl_callback_handler (char *rl) noexcept |
| 208 | { |
| 209 | /* This is static to avoid undefined behavior when calling longjmp |
| 210 | -- gdb_exception has a destructor with side effects. */ |
| 211 | static struct gdb_exception gdb_rl_expt; |
| 212 | struct ui *ui = current_ui; |
| 213 | |
| 214 | try |
| 215 | { |
| 216 | /* Ensure the exception is reset on each call. */ |
| 217 | gdb_rl_expt = {}; |
| 218 | ui->input_handler (gdb::unique_xmalloc_ptr<char> (rl)); |
| 219 | } |
| 220 | catch (gdb_exception &ex) |
| 221 | { |
| 222 | gdb_rl_expt = std::move (ex); |
| 223 | } |
| 224 | |
| 225 | /* If we caught a GDB exception, longjmp out of the readline |
| 226 | callback. There's no other way for the callback to signal to |
| 227 | readline that an error happened. A normal return would have |
| 228 | readline potentially continue processing further input, redisplay |
| 229 | the prompt, etc. (This is what GDB historically did when it was |
| 230 | a C program.) Note that since we're long jumping, local variable |
| 231 | dtors are NOT run automatically. */ |
| 232 | if (gdb_rl_expt.reason < 0) |
| 233 | throw_exception_sjlj (gdb_rl_expt); |
| 234 | } |
| 235 | |
| 236 | /* Change the function to be invoked every time there is a character |
| 237 | ready on stdin. This is used when the user sets the editing off, |
| 238 | therefore bypassing readline, and letting gdb handle the input |
| 239 | itself, via gdb_readline_no_editing_callback. Also it is used in |
| 240 | the opposite case in which the user sets editing on again, by |
| 241 | restoring readline handling of the input. |
| 242 | |
| 243 | NOTE: this operates on input_fd, not instream. If we are reading |
| 244 | commands from a file, instream will point to the file. However, we |
| 245 | always read commands from a file with editing off. This means that |
| 246 | the 'set editing on/off' will have effect only on the interactive |
| 247 | session. */ |
| 248 | |
| 249 | void |
| 250 | change_line_handler (int editing) |
| 251 | { |
| 252 | struct ui *ui = current_ui; |
| 253 | |
| 254 | /* We can only have one instance of readline, so we only allow |
| 255 | editing on the main UI. */ |
| 256 | if (ui != main_ui) |
| 257 | return; |
| 258 | |
| 259 | /* Don't try enabling editing if the interpreter doesn't support it |
| 260 | (e.g., MI). */ |
| 261 | if (!interp_supports_command_editing (top_level_interpreter ()) |
| 262 | || !interp_supports_command_editing (command_interp ())) |
| 263 | return; |
| 264 | |
| 265 | if (editing) |
| 266 | { |
| 267 | gdb_assert (ui == main_ui); |
| 268 | |
| 269 | /* Turn on editing by using readline. */ |
| 270 | ui->call_readline = gdb_rl_callback_read_char_wrapper; |
| 271 | } |
| 272 | else |
| 273 | { |
| 274 | /* Turn off editing by using gdb_readline_no_editing_callback. */ |
| 275 | if (ui->command_editing) |
| 276 | gdb_rl_callback_handler_remove (); |
| 277 | ui->call_readline = gdb_readline_no_editing_callback; |
| 278 | } |
| 279 | ui->command_editing = editing; |
| 280 | } |
| 281 | |
| 282 | /* The functions below are wrappers for rl_callback_handler_remove and |
| 283 | rl_callback_handler_install that keep track of whether the callback |
| 284 | handler is installed in readline. This is necessary because after |
| 285 | handling a target event of a background execution command, we may |
| 286 | need to reinstall the callback handler if it was removed due to a |
| 287 | secondary prompt. See gdb_readline_wrapper_line. We don't |
| 288 | unconditionally install the handler for every target event because |
| 289 | that also clears the line buffer, thus installing it while the user |
| 290 | is typing would lose input. */ |
| 291 | |
| 292 | /* Whether we've registered a callback handler with readline. */ |
| 293 | static int callback_handler_installed; |
| 294 | |
| 295 | /* See event-top.h, and above. */ |
| 296 | |
| 297 | void |
| 298 | gdb_rl_callback_handler_remove (void) |
| 299 | { |
| 300 | gdb_assert (current_ui == main_ui); |
| 301 | |
| 302 | rl_callback_handler_remove (); |
| 303 | callback_handler_installed = 0; |
| 304 | } |
| 305 | |
| 306 | /* See event-top.h, and above. Note this wrapper doesn't have an |
| 307 | actual callback parameter because we always install |
| 308 | INPUT_HANDLER. */ |
| 309 | |
| 310 | void |
| 311 | gdb_rl_callback_handler_install (const char *prompt) |
| 312 | { |
| 313 | gdb_assert (current_ui == main_ui); |
| 314 | |
| 315 | /* Calling rl_callback_handler_install resets readline's input |
| 316 | buffer. Calling this when we were already processing input |
| 317 | therefore loses input. */ |
| 318 | gdb_assert (!callback_handler_installed); |
| 319 | |
| 320 | rl_callback_handler_install (prompt, gdb_rl_callback_handler); |
| 321 | callback_handler_installed = 1; |
| 322 | } |
| 323 | |
| 324 | /* See event-top.h, and above. */ |
| 325 | |
| 326 | void |
| 327 | gdb_rl_callback_handler_reinstall (void) |
| 328 | { |
| 329 | gdb_assert (current_ui == main_ui); |
| 330 | |
| 331 | if (!callback_handler_installed) |
| 332 | { |
| 333 | /* Passing NULL as prompt argument tells readline to not display |
| 334 | a prompt. */ |
| 335 | gdb_rl_callback_handler_install (NULL); |
| 336 | } |
| 337 | } |
| 338 | |
| 339 | /* Displays the prompt. If the argument NEW_PROMPT is NULL, the |
| 340 | prompt that is displayed is the current top level prompt. |
| 341 | Otherwise, it displays whatever NEW_PROMPT is as a local/secondary |
| 342 | prompt. |
| 343 | |
| 344 | This is used after each gdb command has completed, and in the |
| 345 | following cases: |
| 346 | |
| 347 | 1. When the user enters a command line which is ended by '\' |
| 348 | indicating that the command will continue on the next line. In |
| 349 | that case the prompt that is displayed is the empty string. |
| 350 | |
| 351 | 2. When the user is entering 'commands' for a breakpoint, or |
| 352 | actions for a tracepoint. In this case the prompt will be '>' |
| 353 | |
| 354 | 3. On prompting for pagination. */ |
| 355 | |
| 356 | void |
| 357 | display_gdb_prompt (const char *new_prompt) |
| 358 | { |
| 359 | std::string actual_gdb_prompt; |
| 360 | |
| 361 | annotate_display_prompt (); |
| 362 | |
| 363 | /* Reset the nesting depth used when trace-commands is set. */ |
| 364 | reset_command_nest_depth (); |
| 365 | |
| 366 | /* Do not call the python hook on an explicit prompt change as |
| 367 | passed to this function, as this forms a secondary/local prompt, |
| 368 | IE, displayed but not set. */ |
| 369 | if (! new_prompt) |
| 370 | { |
| 371 | struct ui *ui = current_ui; |
| 372 | |
| 373 | if (ui->prompt_state == PROMPTED) |
| 374 | internal_error (__FILE__, __LINE__, _("double prompt")); |
| 375 | else if (ui->prompt_state == PROMPT_BLOCKED) |
| 376 | { |
| 377 | /* This is to trick readline into not trying to display the |
| 378 | prompt. Even though we display the prompt using this |
| 379 | function, readline still tries to do its own display if |
| 380 | we don't call rl_callback_handler_install and |
| 381 | rl_callback_handler_remove (which readline detects |
| 382 | because a global variable is not set). If readline did |
| 383 | that, it could mess up gdb signal handlers for SIGINT. |
| 384 | Readline assumes that between calls to rl_set_signals and |
| 385 | rl_clear_signals gdb doesn't do anything with the signal |
| 386 | handlers. Well, that's not the case, because when the |
| 387 | target executes we change the SIGINT signal handler. If |
| 388 | we allowed readline to display the prompt, the signal |
| 389 | handler change would happen exactly between the calls to |
| 390 | the above two functions. Calling |
| 391 | rl_callback_handler_remove(), does the job. */ |
| 392 | |
| 393 | if (current_ui->command_editing) |
| 394 | gdb_rl_callback_handler_remove (); |
| 395 | return; |
| 396 | } |
| 397 | else if (ui->prompt_state == PROMPT_NEEDED) |
| 398 | { |
| 399 | /* Display the top level prompt. */ |
| 400 | actual_gdb_prompt = top_level_prompt (); |
| 401 | ui->prompt_state = PROMPTED; |
| 402 | } |
| 403 | } |
| 404 | else |
| 405 | actual_gdb_prompt = new_prompt; |
| 406 | |
| 407 | if (current_ui->command_editing) |
| 408 | { |
| 409 | gdb_rl_callback_handler_remove (); |
| 410 | gdb_rl_callback_handler_install (actual_gdb_prompt.c_str ()); |
| 411 | } |
| 412 | /* new_prompt at this point can be the top of the stack or the one |
| 413 | passed in. It can't be NULL. */ |
| 414 | else |
| 415 | { |
| 416 | /* Don't use a _filtered function here. It causes the assumed |
| 417 | character position to be off, since the newline we read from |
| 418 | the user is not accounted for. */ |
| 419 | fputs_unfiltered (actual_gdb_prompt.c_str (), gdb_stdout); |
| 420 | gdb_flush (gdb_stdout); |
| 421 | } |
| 422 | } |
| 423 | |
| 424 | /* Return the top level prompt, as specified by "set prompt", possibly |
| 425 | overridden by the python gdb.prompt_hook hook, and then composed |
| 426 | with the prompt prefix and suffix (annotations). */ |
| 427 | |
| 428 | static std::string |
| 429 | top_level_prompt (void) |
| 430 | { |
| 431 | char *prompt; |
| 432 | |
| 433 | /* Give observers a chance of changing the prompt. E.g., the python |
| 434 | `gdb.prompt_hook' is installed as an observer. */ |
| 435 | gdb::observers::before_prompt.notify (get_prompt ()); |
| 436 | |
| 437 | prompt = get_prompt (); |
| 438 | |
| 439 | if (annotation_level >= 2) |
| 440 | { |
| 441 | /* Prefix needs to have new line at end. */ |
| 442 | const char prefix[] = "\n\032\032pre-prompt\n"; |
| 443 | |
| 444 | /* Suffix needs to have a new line at end and \032 \032 at |
| 445 | beginning. */ |
| 446 | const char suffix[] = "\n\032\032prompt\n"; |
| 447 | |
| 448 | return std::string (prefix) + prompt + suffix; |
| 449 | } |
| 450 | |
| 451 | return prompt; |
| 452 | } |
| 453 | |
| 454 | /* See top.h. */ |
| 455 | |
| 456 | struct ui *main_ui; |
| 457 | struct ui *current_ui; |
| 458 | struct ui *ui_list; |
| 459 | |
| 460 | /* Get a pointer to the current UI's line buffer. This is used to |
| 461 | construct a whole line of input from partial input. */ |
| 462 | |
| 463 | static struct buffer * |
| 464 | get_command_line_buffer (void) |
| 465 | { |
| 466 | return ¤t_ui->line_buffer; |
| 467 | } |
| 468 | |
| 469 | /* When there is an event ready on the stdin file descriptor, instead |
| 470 | of calling readline directly throught the callback function, or |
| 471 | instead of calling gdb_readline_no_editing_callback, give gdb a |
| 472 | chance to detect errors and do something. */ |
| 473 | |
| 474 | void |
| 475 | stdin_event_handler (int error, gdb_client_data client_data) |
| 476 | { |
| 477 | struct ui *ui = (struct ui *) client_data; |
| 478 | |
| 479 | if (error) |
| 480 | { |
| 481 | /* Switch to the main UI, so diagnostics always go there. */ |
| 482 | current_ui = main_ui; |
| 483 | |
| 484 | delete_file_handler (ui->input_fd); |
| 485 | if (main_ui == ui) |
| 486 | { |
| 487 | /* If stdin died, we may as well kill gdb. */ |
| 488 | printf_unfiltered (_("error detected on stdin\n")); |
| 489 | quit_command ((char *) 0, 0); |
| 490 | } |
| 491 | else |
| 492 | { |
| 493 | /* Simply delete the UI. */ |
| 494 | delete ui; |
| 495 | } |
| 496 | } |
| 497 | else |
| 498 | { |
| 499 | /* Switch to the UI whose input descriptor woke up the event |
| 500 | loop. */ |
| 501 | current_ui = ui; |
| 502 | |
| 503 | /* This makes sure a ^C immediately followed by further input is |
| 504 | always processed in that order. E.g,. with input like |
| 505 | "^Cprint 1\n", the SIGINT handler runs, marks the async |
| 506 | signal handler, and then select/poll may return with stdin |
| 507 | ready, instead of -1/EINTR. The |
| 508 | gdb.base/double-prompt-target-event-error.exp test exercises |
| 509 | this. */ |
| 510 | QUIT; |
| 511 | |
| 512 | do |
| 513 | { |
| 514 | call_stdin_event_handler_again_p = 0; |
| 515 | ui->call_readline (client_data); |
| 516 | } |
| 517 | while (call_stdin_event_handler_again_p != 0); |
| 518 | } |
| 519 | } |
| 520 | |
| 521 | /* See top.h. */ |
| 522 | |
| 523 | void |
| 524 | ui_register_input_event_handler (struct ui *ui) |
| 525 | { |
| 526 | add_file_handler (ui->input_fd, stdin_event_handler, ui); |
| 527 | } |
| 528 | |
| 529 | /* See top.h. */ |
| 530 | |
| 531 | void |
| 532 | ui_unregister_input_event_handler (struct ui *ui) |
| 533 | { |
| 534 | delete_file_handler (ui->input_fd); |
| 535 | } |
| 536 | |
| 537 | /* Re-enable stdin after the end of an execution command in |
| 538 | synchronous mode, or after an error from the target, and we aborted |
| 539 | the exec operation. */ |
| 540 | |
| 541 | void |
| 542 | async_enable_stdin (void) |
| 543 | { |
| 544 | struct ui *ui = current_ui; |
| 545 | |
| 546 | if (ui->prompt_state == PROMPT_BLOCKED) |
| 547 | { |
| 548 | target_terminal::ours (); |
| 549 | ui_register_input_event_handler (ui); |
| 550 | ui->prompt_state = PROMPT_NEEDED; |
| 551 | } |
| 552 | } |
| 553 | |
| 554 | /* Disable reads from stdin (the console) marking the command as |
| 555 | synchronous. */ |
| 556 | |
| 557 | void |
| 558 | async_disable_stdin (void) |
| 559 | { |
| 560 | struct ui *ui = current_ui; |
| 561 | |
| 562 | ui->prompt_state = PROMPT_BLOCKED; |
| 563 | delete_file_handler (ui->input_fd); |
| 564 | } |
| 565 | \f |
| 566 | |
| 567 | /* Handle a gdb command line. This function is called when |
| 568 | handle_line_of_input has concatenated one or more input lines into |
| 569 | a whole command. */ |
| 570 | |
| 571 | void |
| 572 | command_handler (const char *command) |
| 573 | { |
| 574 | struct ui *ui = current_ui; |
| 575 | const char *c; |
| 576 | |
| 577 | if (ui->instream == ui->stdin_stream) |
| 578 | reinitialize_more_filter (); |
| 579 | |
| 580 | scoped_command_stats stat_reporter (true); |
| 581 | |
| 582 | /* Do not execute commented lines. */ |
| 583 | for (c = command; *c == ' ' || *c == '\t'; c++) |
| 584 | ; |
| 585 | if (c[0] != '#') |
| 586 | { |
| 587 | execute_command (command, ui->instream == ui->stdin_stream); |
| 588 | |
| 589 | /* Do any commands attached to breakpoint we stopped at. */ |
| 590 | bpstat_do_actions (); |
| 591 | } |
| 592 | } |
| 593 | |
| 594 | /* Append RL, an input line returned by readline or one of its |
| 595 | emulations, to CMD_LINE_BUFFER. Returns the command line if we |
| 596 | have a whole command line ready to be processed by the command |
| 597 | interpreter or NULL if the command line isn't complete yet (input |
| 598 | line ends in a backslash). */ |
| 599 | |
| 600 | static char * |
| 601 | command_line_append_input_line (struct buffer *cmd_line_buffer, const char *rl) |
| 602 | { |
| 603 | char *cmd; |
| 604 | size_t len; |
| 605 | |
| 606 | len = strlen (rl); |
| 607 | |
| 608 | if (len > 0 && rl[len - 1] == '\\') |
| 609 | { |
| 610 | /* Don't copy the backslash and wait for more. */ |
| 611 | buffer_grow (cmd_line_buffer, rl, len - 1); |
| 612 | cmd = NULL; |
| 613 | } |
| 614 | else |
| 615 | { |
| 616 | /* Copy whole line including terminating null, and we're |
| 617 | done. */ |
| 618 | buffer_grow (cmd_line_buffer, rl, len + 1); |
| 619 | cmd = cmd_line_buffer->buffer; |
| 620 | } |
| 621 | |
| 622 | return cmd; |
| 623 | } |
| 624 | |
| 625 | /* Handle a line of input coming from readline. |
| 626 | |
| 627 | If the read line ends with a continuation character (backslash), |
| 628 | save the partial input in CMD_LINE_BUFFER (except the backslash), |
| 629 | and return NULL. Otherwise, save the partial input and return a |
| 630 | pointer to CMD_LINE_BUFFER's buffer (null terminated), indicating a |
| 631 | whole command line is ready to be executed. |
| 632 | |
| 633 | Returns EOF on end of file. |
| 634 | |
| 635 | If REPEAT, handle command repetitions: |
| 636 | |
| 637 | - If the input command line is NOT empty, the command returned is |
| 638 | saved using save_command_line () so that it can be repeated later. |
| 639 | |
| 640 | - OTOH, if the input command line IS empty, return the saved |
| 641 | command instead of the empty input line. |
| 642 | */ |
| 643 | |
| 644 | char * |
| 645 | handle_line_of_input (struct buffer *cmd_line_buffer, |
| 646 | const char *rl, int repeat, |
| 647 | const char *annotation_suffix) |
| 648 | { |
| 649 | struct ui *ui = current_ui; |
| 650 | int from_tty = ui->instream == ui->stdin_stream; |
| 651 | char *p1; |
| 652 | char *cmd; |
| 653 | |
| 654 | if (rl == NULL) |
| 655 | return (char *) EOF; |
| 656 | |
| 657 | cmd = command_line_append_input_line (cmd_line_buffer, rl); |
| 658 | if (cmd == NULL) |
| 659 | return NULL; |
| 660 | |
| 661 | /* We have a complete command line now. Prepare for the next |
| 662 | command, but leave ownership of memory to the buffer . */ |
| 663 | cmd_line_buffer->used_size = 0; |
| 664 | |
| 665 | if (from_tty && annotation_level > 1) |
| 666 | { |
| 667 | printf_unfiltered (("\n\032\032post-")); |
| 668 | puts_unfiltered (annotation_suffix); |
| 669 | printf_unfiltered (("\n")); |
| 670 | } |
| 671 | |
| 672 | #define SERVER_COMMAND_PREFIX "server " |
| 673 | server_command = startswith (cmd, SERVER_COMMAND_PREFIX); |
| 674 | if (server_command) |
| 675 | { |
| 676 | /* Note that we don't call `save_command_line'. Between this |
| 677 | and the check in dont_repeat, this insures that repeating |
| 678 | will still do the right thing. */ |
| 679 | return cmd + strlen (SERVER_COMMAND_PREFIX); |
| 680 | } |
| 681 | |
| 682 | /* Do history expansion if that is wished. */ |
| 683 | if (history_expansion_p && from_tty && input_interactive_p (current_ui)) |
| 684 | { |
| 685 | char *cmd_expansion; |
| 686 | int expanded; |
| 687 | |
| 688 | expanded = history_expand (cmd, &cmd_expansion); |
| 689 | gdb::unique_xmalloc_ptr<char> history_value (cmd_expansion); |
| 690 | if (expanded) |
| 691 | { |
| 692 | size_t len; |
| 693 | |
| 694 | /* Print the changes. */ |
| 695 | printf_unfiltered ("%s\n", history_value.get ()); |
| 696 | |
| 697 | /* If there was an error, call this function again. */ |
| 698 | if (expanded < 0) |
| 699 | return cmd; |
| 700 | |
| 701 | /* history_expand returns an allocated string. Just replace |
| 702 | our buffer with it. */ |
| 703 | len = strlen (history_value.get ()); |
| 704 | xfree (buffer_finish (cmd_line_buffer)); |
| 705 | cmd_line_buffer->buffer = history_value.get (); |
| 706 | cmd_line_buffer->buffer_size = len + 1; |
| 707 | cmd = history_value.release (); |
| 708 | } |
| 709 | } |
| 710 | |
| 711 | /* If we just got an empty line, and that is supposed to repeat the |
| 712 | previous command, return the previously saved command. */ |
| 713 | for (p1 = cmd; *p1 == ' ' || *p1 == '\t'; p1++) |
| 714 | ; |
| 715 | if (repeat && *p1 == '\0') |
| 716 | return get_saved_command_line (); |
| 717 | |
| 718 | /* Add command to history if appropriate. Note: lines consisting |
| 719 | solely of comments are also added to the command history. This |
| 720 | is useful when you type a command, and then realize you don't |
| 721 | want to execute it quite yet. You can comment out the command |
| 722 | and then later fetch it from the value history and remove the |
| 723 | '#'. The kill ring is probably better, but some people are in |
| 724 | the habit of commenting things out. */ |
| 725 | if (*cmd != '\0' && from_tty && input_interactive_p (current_ui)) |
| 726 | gdb_add_history (cmd); |
| 727 | |
| 728 | /* Save into global buffer if appropriate. */ |
| 729 | if (repeat) |
| 730 | { |
| 731 | save_command_line (cmd); |
| 732 | return get_saved_command_line (); |
| 733 | } |
| 734 | else |
| 735 | return cmd; |
| 736 | } |
| 737 | |
| 738 | /* Handle a complete line of input. This is called by the callback |
| 739 | mechanism within the readline library. Deal with incomplete |
| 740 | commands as well, by saving the partial input in a global |
| 741 | buffer. |
| 742 | |
| 743 | NOTE: This is the asynchronous version of the command_line_input |
| 744 | function. */ |
| 745 | |
| 746 | void |
| 747 | command_line_handler (gdb::unique_xmalloc_ptr<char> &&rl) |
| 748 | { |
| 749 | struct buffer *line_buffer = get_command_line_buffer (); |
| 750 | struct ui *ui = current_ui; |
| 751 | char *cmd; |
| 752 | |
| 753 | cmd = handle_line_of_input (line_buffer, rl.get (), 1, "prompt"); |
| 754 | if (cmd == (char *) EOF) |
| 755 | { |
| 756 | /* stdin closed. The connection with the terminal is gone. |
| 757 | This happens at the end of a testsuite run, after Expect has |
| 758 | hung up but GDB is still alive. In such a case, we just quit |
| 759 | gdb killing the inferior program too. */ |
| 760 | printf_unfiltered ("quit\n"); |
| 761 | execute_command ("quit", 1); |
| 762 | } |
| 763 | else if (cmd == NULL) |
| 764 | { |
| 765 | /* We don't have a full line yet. Print an empty prompt. */ |
| 766 | display_gdb_prompt (""); |
| 767 | } |
| 768 | else |
| 769 | { |
| 770 | ui->prompt_state = PROMPT_NEEDED; |
| 771 | |
| 772 | command_handler (cmd); |
| 773 | |
| 774 | if (ui->prompt_state != PROMPTED) |
| 775 | display_gdb_prompt (0); |
| 776 | } |
| 777 | } |
| 778 | |
| 779 | /* Does reading of input from terminal w/o the editing features |
| 780 | provided by the readline library. Calls the line input handler |
| 781 | once we have a whole input line. */ |
| 782 | |
| 783 | void |
| 784 | gdb_readline_no_editing_callback (gdb_client_data client_data) |
| 785 | { |
| 786 | int c; |
| 787 | char *result; |
| 788 | struct buffer line_buffer; |
| 789 | static int done_once = 0; |
| 790 | struct ui *ui = current_ui; |
| 791 | |
| 792 | buffer_init (&line_buffer); |
| 793 | |
| 794 | /* Unbuffer the input stream, so that, later on, the calls to fgetc |
| 795 | fetch only one char at the time from the stream. The fgetc's will |
| 796 | get up to the first newline, but there may be more chars in the |
| 797 | stream after '\n'. If we buffer the input and fgetc drains the |
| 798 | stream, getting stuff beyond the newline as well, a select, done |
| 799 | afterwards will not trigger. */ |
| 800 | if (!done_once && !ISATTY (ui->instream)) |
| 801 | { |
| 802 | setbuf (ui->instream, NULL); |
| 803 | done_once = 1; |
| 804 | } |
| 805 | |
| 806 | /* We still need the while loop here, even though it would seem |
| 807 | obvious to invoke gdb_readline_no_editing_callback at every |
| 808 | character entered. If not using the readline library, the |
| 809 | terminal is in cooked mode, which sends the characters all at |
| 810 | once. Poll will notice that the input fd has changed state only |
| 811 | after enter is pressed. At this point we still need to fetch all |
| 812 | the chars entered. */ |
| 813 | |
| 814 | while (1) |
| 815 | { |
| 816 | /* Read from stdin if we are executing a user defined command. |
| 817 | This is the right thing for prompt_for_continue, at least. */ |
| 818 | c = fgetc (ui->instream != NULL ? ui->instream : ui->stdin_stream); |
| 819 | |
| 820 | if (c == EOF) |
| 821 | { |
| 822 | if (line_buffer.used_size > 0) |
| 823 | { |
| 824 | /* The last line does not end with a newline. Return it, and |
| 825 | if we are called again fgetc will still return EOF and |
| 826 | we'll return NULL then. */ |
| 827 | break; |
| 828 | } |
| 829 | xfree (buffer_finish (&line_buffer)); |
| 830 | ui->input_handler (NULL); |
| 831 | return; |
| 832 | } |
| 833 | |
| 834 | if (c == '\n') |
| 835 | { |
| 836 | if (line_buffer.used_size > 0 |
| 837 | && line_buffer.buffer[line_buffer.used_size - 1] == '\r') |
| 838 | line_buffer.used_size--; |
| 839 | break; |
| 840 | } |
| 841 | |
| 842 | buffer_grow_char (&line_buffer, c); |
| 843 | } |
| 844 | |
| 845 | buffer_grow_char (&line_buffer, '\0'); |
| 846 | result = buffer_finish (&line_buffer); |
| 847 | ui->input_handler (gdb::unique_xmalloc_ptr<char> (result)); |
| 848 | } |
| 849 | \f |
| 850 | |
| 851 | /* See event-top.h. */ |
| 852 | |
| 853 | thread_local void (*thread_local_segv_handler) (int); |
| 854 | |
| 855 | static void handle_sigsegv (int sig); |
| 856 | |
| 857 | /* Install the SIGSEGV handler. */ |
| 858 | static void |
| 859 | install_handle_sigsegv () |
| 860 | { |
| 861 | #if defined (HAVE_SIGACTION) |
| 862 | struct sigaction sa; |
| 863 | sa.sa_handler = handle_sigsegv; |
| 864 | sigemptyset (&sa.sa_mask); |
| 865 | #ifdef HAVE_SIGALTSTACK |
| 866 | sa.sa_flags = SA_ONSTACK; |
| 867 | #else |
| 868 | sa.sa_flags = 0; |
| 869 | #endif |
| 870 | sigaction (SIGSEGV, &sa, nullptr); |
| 871 | #else |
| 872 | signal (SIGSEGV, handle_sigsegv); |
| 873 | #endif |
| 874 | } |
| 875 | |
| 876 | /* Handler for SIGSEGV. */ |
| 877 | |
| 878 | static void |
| 879 | handle_sigsegv (int sig) |
| 880 | { |
| 881 | install_handle_sigsegv (); |
| 882 | |
| 883 | if (thread_local_segv_handler == nullptr) |
| 884 | abort (); /* ARI: abort */ |
| 885 | thread_local_segv_handler (sig); |
| 886 | } |
| 887 | |
| 888 | \f |
| 889 | |
| 890 | /* The serial event associated with the QUIT flag. set_quit_flag sets |
| 891 | this, and check_quit_flag clears it. Used by interruptible_select |
| 892 | to be able to do interruptible I/O with no race with the SIGINT |
| 893 | handler. */ |
| 894 | static struct serial_event *quit_serial_event; |
| 895 | |
| 896 | /* Initialization of signal handlers and tokens. There is a function |
| 897 | handle_sig* for each of the signals GDB cares about. Specifically: |
| 898 | SIGINT, SIGFPE, SIGQUIT, SIGTSTP, SIGHUP, SIGWINCH. These |
| 899 | functions are the actual signal handlers associated to the signals |
| 900 | via calls to signal(). The only job for these functions is to |
| 901 | enqueue the appropriate event/procedure with the event loop. Such |
| 902 | procedures are the old signal handlers. The event loop will take |
| 903 | care of invoking the queued procedures to perform the usual tasks |
| 904 | associated with the reception of the signal. */ |
| 905 | /* NOTE: 1999-04-30 This is the asynchronous version of init_signals. |
| 906 | init_signals will become obsolete as we move to have to event loop |
| 907 | as the default for gdb. */ |
| 908 | void |
| 909 | async_init_signals (void) |
| 910 | { |
| 911 | initialize_async_signal_handlers (); |
| 912 | |
| 913 | quit_serial_event = make_serial_event (); |
| 914 | |
| 915 | signal (SIGINT, handle_sigint); |
| 916 | sigint_token = |
| 917 | create_async_signal_handler (async_request_quit, NULL); |
| 918 | signal (SIGTERM, handle_sigterm); |
| 919 | async_sigterm_token |
| 920 | = create_async_signal_handler (async_sigterm_handler, NULL); |
| 921 | |
| 922 | /* If SIGTRAP was set to SIG_IGN, then the SIG_IGN will get passed |
| 923 | to the inferior and breakpoints will be ignored. */ |
| 924 | #ifdef SIGTRAP |
| 925 | signal (SIGTRAP, SIG_DFL); |
| 926 | #endif |
| 927 | |
| 928 | #ifdef SIGQUIT |
| 929 | /* If we initialize SIGQUIT to SIG_IGN, then the SIG_IGN will get |
| 930 | passed to the inferior, which we don't want. It would be |
| 931 | possible to do a "signal (SIGQUIT, SIG_DFL)" after we fork, but |
| 932 | on BSD4.3 systems using vfork, that can affect the |
| 933 | GDB process as well as the inferior (the signal handling tables |
| 934 | might be in memory, shared between the two). Since we establish |
| 935 | a handler for SIGQUIT, when we call exec it will set the signal |
| 936 | to SIG_DFL for us. */ |
| 937 | signal (SIGQUIT, handle_sigquit); |
| 938 | sigquit_token = |
| 939 | create_async_signal_handler (async_do_nothing, NULL); |
| 940 | #endif |
| 941 | #ifdef SIGHUP |
| 942 | if (signal (SIGHUP, handle_sighup) != SIG_IGN) |
| 943 | sighup_token = |
| 944 | create_async_signal_handler (async_disconnect, NULL); |
| 945 | else |
| 946 | sighup_token = |
| 947 | create_async_signal_handler (async_do_nothing, NULL); |
| 948 | #endif |
| 949 | signal (SIGFPE, handle_sigfpe); |
| 950 | sigfpe_token = |
| 951 | create_async_signal_handler (async_float_handler, NULL); |
| 952 | |
| 953 | #ifdef SIGTSTP |
| 954 | sigtstp_token = |
| 955 | create_async_signal_handler (async_sigtstp_handler, NULL); |
| 956 | #endif |
| 957 | |
| 958 | install_handle_sigsegv (); |
| 959 | } |
| 960 | |
| 961 | /* See defs.h. */ |
| 962 | |
| 963 | void |
| 964 | quit_serial_event_set (void) |
| 965 | { |
| 966 | serial_event_set (quit_serial_event); |
| 967 | } |
| 968 | |
| 969 | /* See defs.h. */ |
| 970 | |
| 971 | void |
| 972 | quit_serial_event_clear (void) |
| 973 | { |
| 974 | serial_event_clear (quit_serial_event); |
| 975 | } |
| 976 | |
| 977 | /* Return the selectable file descriptor of the serial event |
| 978 | associated with the quit flag. */ |
| 979 | |
| 980 | static int |
| 981 | quit_serial_event_fd (void) |
| 982 | { |
| 983 | return serial_event_fd (quit_serial_event); |
| 984 | } |
| 985 | |
| 986 | /* See defs.h. */ |
| 987 | |
| 988 | void |
| 989 | default_quit_handler (void) |
| 990 | { |
| 991 | if (check_quit_flag ()) |
| 992 | { |
| 993 | if (target_terminal::is_ours ()) |
| 994 | quit (); |
| 995 | else |
| 996 | target_pass_ctrlc (); |
| 997 | } |
| 998 | } |
| 999 | |
| 1000 | /* See defs.h. */ |
| 1001 | quit_handler_ftype *quit_handler = default_quit_handler; |
| 1002 | |
| 1003 | /* Handle a SIGINT. */ |
| 1004 | |
| 1005 | void |
| 1006 | handle_sigint (int sig) |
| 1007 | { |
| 1008 | signal (sig, handle_sigint); |
| 1009 | |
| 1010 | /* We could be running in a loop reading in symfiles or something so |
| 1011 | it may be quite a while before we get back to the event loop. So |
| 1012 | set quit_flag to 1 here. Then if QUIT is called before we get to |
| 1013 | the event loop, we will unwind as expected. */ |
| 1014 | set_quit_flag (); |
| 1015 | |
| 1016 | /* In case nothing calls QUIT before the event loop is reached, the |
| 1017 | event loop handles it. */ |
| 1018 | mark_async_signal_handler (sigint_token); |
| 1019 | } |
| 1020 | |
| 1021 | /* See gdb_select.h. */ |
| 1022 | |
| 1023 | int |
| 1024 | interruptible_select (int n, |
| 1025 | fd_set *readfds, fd_set *writefds, fd_set *exceptfds, |
| 1026 | struct timeval *timeout) |
| 1027 | { |
| 1028 | fd_set my_readfds; |
| 1029 | int fd; |
| 1030 | int res; |
| 1031 | |
| 1032 | if (readfds == NULL) |
| 1033 | { |
| 1034 | readfds = &my_readfds; |
| 1035 | FD_ZERO (&my_readfds); |
| 1036 | } |
| 1037 | |
| 1038 | fd = quit_serial_event_fd (); |
| 1039 | FD_SET (fd, readfds); |
| 1040 | if (n <= fd) |
| 1041 | n = fd + 1; |
| 1042 | |
| 1043 | do |
| 1044 | { |
| 1045 | res = gdb_select (n, readfds, writefds, exceptfds, timeout); |
| 1046 | } |
| 1047 | while (res == -1 && errno == EINTR); |
| 1048 | |
| 1049 | if (res == 1 && FD_ISSET (fd, readfds)) |
| 1050 | { |
| 1051 | errno = EINTR; |
| 1052 | return -1; |
| 1053 | } |
| 1054 | return res; |
| 1055 | } |
| 1056 | |
| 1057 | /* Handle GDB exit upon receiving SIGTERM if target_can_async_p (). */ |
| 1058 | |
| 1059 | static void |
| 1060 | async_sigterm_handler (gdb_client_data arg) |
| 1061 | { |
| 1062 | quit_force (NULL, 0); |
| 1063 | } |
| 1064 | |
| 1065 | /* See defs.h. */ |
| 1066 | volatile int sync_quit_force_run; |
| 1067 | |
| 1068 | /* Quit GDB if SIGTERM is received. |
| 1069 | GDB would quit anyway, but this way it will clean up properly. */ |
| 1070 | void |
| 1071 | handle_sigterm (int sig) |
| 1072 | { |
| 1073 | signal (sig, handle_sigterm); |
| 1074 | |
| 1075 | sync_quit_force_run = 1; |
| 1076 | set_quit_flag (); |
| 1077 | |
| 1078 | mark_async_signal_handler (async_sigterm_token); |
| 1079 | } |
| 1080 | |
| 1081 | /* Do the quit. All the checks have been done by the caller. */ |
| 1082 | void |
| 1083 | async_request_quit (gdb_client_data arg) |
| 1084 | { |
| 1085 | /* If the quit_flag has gotten reset back to 0 by the time we get |
| 1086 | back here, that means that an exception was thrown to unwind the |
| 1087 | current command before we got back to the event loop. So there |
| 1088 | is no reason to call quit again here. */ |
| 1089 | QUIT; |
| 1090 | } |
| 1091 | |
| 1092 | #ifdef SIGQUIT |
| 1093 | /* Tell the event loop what to do if SIGQUIT is received. |
| 1094 | See event-signal.c. */ |
| 1095 | static void |
| 1096 | handle_sigquit (int sig) |
| 1097 | { |
| 1098 | mark_async_signal_handler (sigquit_token); |
| 1099 | signal (sig, handle_sigquit); |
| 1100 | } |
| 1101 | #endif |
| 1102 | |
| 1103 | #if defined (SIGQUIT) || defined (SIGHUP) |
| 1104 | /* Called by the event loop in response to a SIGQUIT or an |
| 1105 | ignored SIGHUP. */ |
| 1106 | static void |
| 1107 | async_do_nothing (gdb_client_data arg) |
| 1108 | { |
| 1109 | /* Empty function body. */ |
| 1110 | } |
| 1111 | #endif |
| 1112 | |
| 1113 | #ifdef SIGHUP |
| 1114 | /* Tell the event loop what to do if SIGHUP is received. |
| 1115 | See event-signal.c. */ |
| 1116 | static void |
| 1117 | handle_sighup (int sig) |
| 1118 | { |
| 1119 | mark_async_signal_handler (sighup_token); |
| 1120 | signal (sig, handle_sighup); |
| 1121 | } |
| 1122 | |
| 1123 | /* Called by the event loop to process a SIGHUP. */ |
| 1124 | static void |
| 1125 | async_disconnect (gdb_client_data arg) |
| 1126 | { |
| 1127 | |
| 1128 | try |
| 1129 | { |
| 1130 | quit_cover (); |
| 1131 | } |
| 1132 | |
| 1133 | catch (const gdb_exception &exception) |
| 1134 | { |
| 1135 | fputs_filtered ("Could not kill the program being debugged", |
| 1136 | gdb_stderr); |
| 1137 | exception_print (gdb_stderr, exception); |
| 1138 | } |
| 1139 | |
| 1140 | try |
| 1141 | { |
| 1142 | pop_all_targets (); |
| 1143 | } |
| 1144 | catch (const gdb_exception &exception) |
| 1145 | { |
| 1146 | } |
| 1147 | |
| 1148 | signal (SIGHUP, SIG_DFL); /*FIXME: ??????????? */ |
| 1149 | raise (SIGHUP); |
| 1150 | } |
| 1151 | #endif |
| 1152 | |
| 1153 | #ifdef SIGTSTP |
| 1154 | void |
| 1155 | handle_sigtstp (int sig) |
| 1156 | { |
| 1157 | mark_async_signal_handler (sigtstp_token); |
| 1158 | signal (sig, handle_sigtstp); |
| 1159 | } |
| 1160 | |
| 1161 | static void |
| 1162 | async_sigtstp_handler (gdb_client_data arg) |
| 1163 | { |
| 1164 | char *prompt = get_prompt (); |
| 1165 | |
| 1166 | signal (SIGTSTP, SIG_DFL); |
| 1167 | #if HAVE_SIGPROCMASK |
| 1168 | { |
| 1169 | sigset_t zero; |
| 1170 | |
| 1171 | sigemptyset (&zero); |
| 1172 | gdb_sigmask (SIG_SETMASK, &zero, 0); |
| 1173 | } |
| 1174 | #elif HAVE_SIGSETMASK |
| 1175 | sigsetmask (0); |
| 1176 | #endif |
| 1177 | raise (SIGTSTP); |
| 1178 | signal (SIGTSTP, handle_sigtstp); |
| 1179 | printf_unfiltered ("%s", prompt); |
| 1180 | gdb_flush (gdb_stdout); |
| 1181 | |
| 1182 | /* Forget about any previous command -- null line now will do |
| 1183 | nothing. */ |
| 1184 | dont_repeat (); |
| 1185 | } |
| 1186 | #endif /* SIGTSTP */ |
| 1187 | |
| 1188 | /* Tell the event loop what to do if SIGFPE is received. |
| 1189 | See event-signal.c. */ |
| 1190 | static void |
| 1191 | handle_sigfpe (int sig) |
| 1192 | { |
| 1193 | mark_async_signal_handler (sigfpe_token); |
| 1194 | signal (sig, handle_sigfpe); |
| 1195 | } |
| 1196 | |
| 1197 | /* Event loop will call this function to process a SIGFPE. */ |
| 1198 | static void |
| 1199 | async_float_handler (gdb_client_data arg) |
| 1200 | { |
| 1201 | /* This message is based on ANSI C, section 4.7. Note that integer |
| 1202 | divide by zero causes this, so "float" is a misnomer. */ |
| 1203 | error (_("Erroneous arithmetic operation.")); |
| 1204 | } |
| 1205 | \f |
| 1206 | |
| 1207 | /* Set things up for readline to be invoked via the alternate |
| 1208 | interface, i.e. via a callback function |
| 1209 | (gdb_rl_callback_read_char), and hook up instream to the event |
| 1210 | loop. */ |
| 1211 | |
| 1212 | void |
| 1213 | gdb_setup_readline (int editing) |
| 1214 | { |
| 1215 | struct ui *ui = current_ui; |
| 1216 | |
| 1217 | /* This function is a noop for the sync case. The assumption is |
| 1218 | that the sync setup is ALL done in gdb_init, and we would only |
| 1219 | mess it up here. The sync stuff should really go away over |
| 1220 | time. */ |
| 1221 | if (!batch_silent) |
| 1222 | gdb_stdout = new stdio_file (ui->outstream); |
| 1223 | gdb_stderr = new stderr_file (ui->errstream); |
| 1224 | gdb_stdlog = gdb_stderr; /* for moment */ |
| 1225 | gdb_stdtarg = gdb_stderr; /* for moment */ |
| 1226 | gdb_stdtargerr = gdb_stderr; /* for moment */ |
| 1227 | |
| 1228 | /* If the input stream is connected to a terminal, turn on editing. |
| 1229 | However, that is only allowed on the main UI, as we can only have |
| 1230 | one instance of readline. */ |
| 1231 | if (ISATTY (ui->instream) && editing && ui == main_ui) |
| 1232 | { |
| 1233 | /* Tell gdb that we will be using the readline library. This |
| 1234 | could be overwritten by a command in .gdbinit like 'set |
| 1235 | editing on' or 'off'. */ |
| 1236 | ui->command_editing = 1; |
| 1237 | |
| 1238 | /* When a character is detected on instream by select or poll, |
| 1239 | readline will be invoked via this callback function. */ |
| 1240 | ui->call_readline = gdb_rl_callback_read_char_wrapper; |
| 1241 | |
| 1242 | /* Tell readline to use the same input stream that gdb uses. */ |
| 1243 | rl_instream = ui->instream; |
| 1244 | } |
| 1245 | else |
| 1246 | { |
| 1247 | ui->command_editing = 0; |
| 1248 | ui->call_readline = gdb_readline_no_editing_callback; |
| 1249 | } |
| 1250 | |
| 1251 | /* Now create the event source for this UI's input file descriptor. |
| 1252 | Another source is going to be the target program (inferior), but |
| 1253 | that must be registered only when it actually exists (I.e. after |
| 1254 | we say 'run' or after we connect to a remote target. */ |
| 1255 | ui_register_input_event_handler (ui); |
| 1256 | } |
| 1257 | |
| 1258 | /* Disable command input through the standard CLI channels. Used in |
| 1259 | the suspend proc for interpreters that use the standard gdb readline |
| 1260 | interface, like the cli & the mi. */ |
| 1261 | |
| 1262 | void |
| 1263 | gdb_disable_readline (void) |
| 1264 | { |
| 1265 | struct ui *ui = current_ui; |
| 1266 | |
| 1267 | /* FIXME - It is too heavyweight to delete and remake these every |
| 1268 | time you run an interpreter that needs readline. It is probably |
| 1269 | better to have the interpreters cache these, which in turn means |
| 1270 | that this needs to be moved into interpreter specific code. */ |
| 1271 | |
| 1272 | #if 0 |
| 1273 | ui_file_delete (gdb_stdout); |
| 1274 | ui_file_delete (gdb_stderr); |
| 1275 | gdb_stdlog = NULL; |
| 1276 | gdb_stdtarg = NULL; |
| 1277 | gdb_stdtargerr = NULL; |
| 1278 | #endif |
| 1279 | |
| 1280 | if (ui->command_editing) |
| 1281 | gdb_rl_callback_handler_remove (); |
| 1282 | delete_file_handler (ui->input_fd); |
| 1283 | } |