| 1 | /* Everything about signal catchpoints, for GDB. |
| 2 | |
| 3 | Copyright (C) 2011-2017 Free Software Foundation, Inc. |
| 4 | |
| 5 | This file is part of GDB. |
| 6 | |
| 7 | This program is free software; you can redistribute it and/or modify |
| 8 | it under the terms of the GNU General Public License as published by |
| 9 | the Free Software Foundation; either version 3 of the License, or |
| 10 | (at your option) any later version. |
| 11 | |
| 12 | This program is distributed in the hope that it will be useful, |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | GNU General Public License for more details. |
| 16 | |
| 17 | You should have received a copy of the GNU General Public License |
| 18 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 19 | |
| 20 | #include "defs.h" |
| 21 | #include "arch-utils.h" |
| 22 | #include <ctype.h> |
| 23 | #include "breakpoint.h" |
| 24 | #include "gdbcmd.h" |
| 25 | #include "inferior.h" |
| 26 | #include "infrun.h" |
| 27 | #include "annotate.h" |
| 28 | #include "valprint.h" |
| 29 | #include "cli/cli-utils.h" |
| 30 | #include "completer.h" |
| 31 | |
| 32 | #include <string> |
| 33 | |
| 34 | #define INTERNAL_SIGNAL(x) ((x) == GDB_SIGNAL_TRAP || (x) == GDB_SIGNAL_INT) |
| 35 | |
| 36 | typedef enum gdb_signal gdb_signal_type; |
| 37 | |
| 38 | DEF_VEC_I (gdb_signal_type); |
| 39 | |
| 40 | /* An instance of this type is used to represent a signal catchpoint. |
| 41 | It includes a "struct breakpoint" as a kind of base class; users |
| 42 | downcast to "struct breakpoint *" when needed. A breakpoint is |
| 43 | really of this type iff its ops pointer points to |
| 44 | SIGNAL_CATCHPOINT_OPS. */ |
| 45 | |
| 46 | struct signal_catchpoint |
| 47 | { |
| 48 | /* The base class. */ |
| 49 | |
| 50 | struct breakpoint base; |
| 51 | |
| 52 | /* Signal numbers used for the 'catch signal' feature. If no signal |
| 53 | has been specified for filtering, its value is NULL. Otherwise, |
| 54 | it holds a list of all signals to be caught. */ |
| 55 | |
| 56 | VEC (gdb_signal_type) *signals_to_be_caught; |
| 57 | |
| 58 | /* If SIGNALS_TO_BE_CAUGHT is NULL, then all "ordinary" signals are |
| 59 | caught. If CATCH_ALL is non-zero, then internal signals are |
| 60 | caught as well. If SIGNALS_TO_BE_CAUGHT is non-NULL, then this |
| 61 | field is ignored. */ |
| 62 | |
| 63 | int catch_all; |
| 64 | }; |
| 65 | |
| 66 | /* The breakpoint_ops structure to be used in signal catchpoints. */ |
| 67 | |
| 68 | static struct breakpoint_ops signal_catchpoint_ops; |
| 69 | |
| 70 | /* Count of each signal. */ |
| 71 | |
| 72 | static unsigned int *signal_catch_counts; |
| 73 | |
| 74 | \f |
| 75 | |
| 76 | /* A convenience wrapper for gdb_signal_to_name that returns the |
| 77 | integer value if the name is not known. */ |
| 78 | |
| 79 | static const char * |
| 80 | signal_to_name_or_int (enum gdb_signal sig) |
| 81 | { |
| 82 | const char *result = gdb_signal_to_name (sig); |
| 83 | |
| 84 | if (strcmp (result, "?") == 0) |
| 85 | result = plongest (sig); |
| 86 | |
| 87 | return result; |
| 88 | } |
| 89 | |
| 90 | \f |
| 91 | |
| 92 | /* Implement the "dtor" breakpoint_ops method for signal |
| 93 | catchpoints. */ |
| 94 | |
| 95 | static void |
| 96 | signal_catchpoint_dtor (struct breakpoint *b) |
| 97 | { |
| 98 | struct signal_catchpoint *c = (struct signal_catchpoint *) b; |
| 99 | |
| 100 | VEC_free (gdb_signal_type, c->signals_to_be_caught); |
| 101 | |
| 102 | base_breakpoint_ops.dtor (b); |
| 103 | } |
| 104 | |
| 105 | /* Implement the "insert_location" breakpoint_ops method for signal |
| 106 | catchpoints. */ |
| 107 | |
| 108 | static int |
| 109 | signal_catchpoint_insert_location (struct bp_location *bl) |
| 110 | { |
| 111 | struct signal_catchpoint *c = (struct signal_catchpoint *) bl->owner; |
| 112 | int i; |
| 113 | |
| 114 | if (c->signals_to_be_caught != NULL) |
| 115 | { |
| 116 | gdb_signal_type iter; |
| 117 | |
| 118 | for (i = 0; |
| 119 | VEC_iterate (gdb_signal_type, c->signals_to_be_caught, i, iter); |
| 120 | i++) |
| 121 | ++signal_catch_counts[iter]; |
| 122 | } |
| 123 | else |
| 124 | { |
| 125 | for (i = 0; i < GDB_SIGNAL_LAST; ++i) |
| 126 | { |
| 127 | if (c->catch_all || !INTERNAL_SIGNAL (i)) |
| 128 | ++signal_catch_counts[i]; |
| 129 | } |
| 130 | } |
| 131 | |
| 132 | signal_catch_update (signal_catch_counts); |
| 133 | |
| 134 | return 0; |
| 135 | } |
| 136 | |
| 137 | /* Implement the "remove_location" breakpoint_ops method for signal |
| 138 | catchpoints. */ |
| 139 | |
| 140 | static int |
| 141 | signal_catchpoint_remove_location (struct bp_location *bl, |
| 142 | enum remove_bp_reason reason) |
| 143 | { |
| 144 | struct signal_catchpoint *c = (struct signal_catchpoint *) bl->owner; |
| 145 | int i; |
| 146 | |
| 147 | if (c->signals_to_be_caught != NULL) |
| 148 | { |
| 149 | gdb_signal_type iter; |
| 150 | |
| 151 | for (i = 0; |
| 152 | VEC_iterate (gdb_signal_type, c->signals_to_be_caught, i, iter); |
| 153 | i++) |
| 154 | { |
| 155 | gdb_assert (signal_catch_counts[iter] > 0); |
| 156 | --signal_catch_counts[iter]; |
| 157 | } |
| 158 | } |
| 159 | else |
| 160 | { |
| 161 | for (i = 0; i < GDB_SIGNAL_LAST; ++i) |
| 162 | { |
| 163 | if (c->catch_all || !INTERNAL_SIGNAL (i)) |
| 164 | { |
| 165 | gdb_assert (signal_catch_counts[i] > 0); |
| 166 | --signal_catch_counts[i]; |
| 167 | } |
| 168 | } |
| 169 | } |
| 170 | |
| 171 | signal_catch_update (signal_catch_counts); |
| 172 | |
| 173 | return 0; |
| 174 | } |
| 175 | |
| 176 | /* Implement the "breakpoint_hit" breakpoint_ops method for signal |
| 177 | catchpoints. */ |
| 178 | |
| 179 | static int |
| 180 | signal_catchpoint_breakpoint_hit (const struct bp_location *bl, |
| 181 | struct address_space *aspace, |
| 182 | CORE_ADDR bp_addr, |
| 183 | const struct target_waitstatus *ws) |
| 184 | { |
| 185 | const struct signal_catchpoint *c |
| 186 | = (const struct signal_catchpoint *) bl->owner; |
| 187 | gdb_signal_type signal_number; |
| 188 | |
| 189 | if (ws->kind != TARGET_WAITKIND_STOPPED) |
| 190 | return 0; |
| 191 | |
| 192 | signal_number = ws->value.sig; |
| 193 | |
| 194 | /* If we are catching specific signals in this breakpoint, then we |
| 195 | must guarantee that the called signal is the same signal we are |
| 196 | catching. */ |
| 197 | if (c->signals_to_be_caught) |
| 198 | { |
| 199 | int i; |
| 200 | gdb_signal_type iter; |
| 201 | |
| 202 | for (i = 0; |
| 203 | VEC_iterate (gdb_signal_type, c->signals_to_be_caught, i, iter); |
| 204 | i++) |
| 205 | if (signal_number == iter) |
| 206 | return 1; |
| 207 | /* Not the same. */ |
| 208 | gdb_assert (!iter); |
| 209 | return 0; |
| 210 | } |
| 211 | else |
| 212 | return c->catch_all || !INTERNAL_SIGNAL (signal_number); |
| 213 | } |
| 214 | |
| 215 | /* Implement the "print_it" breakpoint_ops method for signal |
| 216 | catchpoints. */ |
| 217 | |
| 218 | static enum print_stop_action |
| 219 | signal_catchpoint_print_it (bpstat bs) |
| 220 | { |
| 221 | struct breakpoint *b = bs->breakpoint_at; |
| 222 | ptid_t ptid; |
| 223 | struct target_waitstatus last; |
| 224 | const char *signal_name; |
| 225 | struct ui_out *uiout = current_uiout; |
| 226 | |
| 227 | get_last_target_status (&ptid, &last); |
| 228 | |
| 229 | signal_name = signal_to_name_or_int (last.value.sig); |
| 230 | |
| 231 | annotate_catchpoint (b->number); |
| 232 | maybe_print_thread_hit_breakpoint (uiout); |
| 233 | |
| 234 | printf_filtered (_("Catchpoint %d (signal %s), "), b->number, signal_name); |
| 235 | |
| 236 | return PRINT_SRC_AND_LOC; |
| 237 | } |
| 238 | |
| 239 | /* Implement the "print_one" breakpoint_ops method for signal |
| 240 | catchpoints. */ |
| 241 | |
| 242 | static void |
| 243 | signal_catchpoint_print_one (struct breakpoint *b, |
| 244 | struct bp_location **last_loc) |
| 245 | { |
| 246 | struct signal_catchpoint *c = (struct signal_catchpoint *) b; |
| 247 | struct value_print_options opts; |
| 248 | struct ui_out *uiout = current_uiout; |
| 249 | |
| 250 | get_user_print_options (&opts); |
| 251 | |
| 252 | /* Field 4, the address, is omitted (which makes the columns |
| 253 | not line up too nicely with the headers, but the effect |
| 254 | is relatively readable). */ |
| 255 | if (opts.addressprint) |
| 256 | uiout->field_skip ("addr"); |
| 257 | annotate_field (5); |
| 258 | |
| 259 | if (c->signals_to_be_caught |
| 260 | && VEC_length (gdb_signal_type, c->signals_to_be_caught) > 1) |
| 261 | uiout->text ("signals \""); |
| 262 | else |
| 263 | uiout->text ("signal \""); |
| 264 | |
| 265 | if (c->signals_to_be_caught) |
| 266 | { |
| 267 | int i; |
| 268 | gdb_signal_type iter; |
| 269 | std::string text; |
| 270 | |
| 271 | for (i = 0; |
| 272 | VEC_iterate (gdb_signal_type, c->signals_to_be_caught, i, iter); |
| 273 | i++) |
| 274 | { |
| 275 | const char *name = signal_to_name_or_int (iter); |
| 276 | |
| 277 | if (i > 0) |
| 278 | text += " "; |
| 279 | text += name; |
| 280 | } |
| 281 | uiout->field_string ("what", text.c_str ()); |
| 282 | } |
| 283 | else |
| 284 | uiout->field_string ("what", |
| 285 | c->catch_all ? "<any signal>" : "<standard signals>"); |
| 286 | uiout->text ("\" "); |
| 287 | |
| 288 | if (uiout->is_mi_like_p ()) |
| 289 | uiout->field_string ("catch-type", "signal"); |
| 290 | } |
| 291 | |
| 292 | /* Implement the "print_mention" breakpoint_ops method for signal |
| 293 | catchpoints. */ |
| 294 | |
| 295 | static void |
| 296 | signal_catchpoint_print_mention (struct breakpoint *b) |
| 297 | { |
| 298 | struct signal_catchpoint *c = (struct signal_catchpoint *) b; |
| 299 | |
| 300 | if (c->signals_to_be_caught) |
| 301 | { |
| 302 | int i; |
| 303 | gdb_signal_type iter; |
| 304 | |
| 305 | if (VEC_length (gdb_signal_type, c->signals_to_be_caught) > 1) |
| 306 | printf_filtered (_("Catchpoint %d (signals"), b->number); |
| 307 | else |
| 308 | printf_filtered (_("Catchpoint %d (signal"), b->number); |
| 309 | |
| 310 | for (i = 0; |
| 311 | VEC_iterate (gdb_signal_type, c->signals_to_be_caught, i, iter); |
| 312 | i++) |
| 313 | { |
| 314 | const char *name = signal_to_name_or_int (iter); |
| 315 | |
| 316 | printf_filtered (" %s", name); |
| 317 | } |
| 318 | printf_filtered (")"); |
| 319 | } |
| 320 | else if (c->catch_all) |
| 321 | printf_filtered (_("Catchpoint %d (any signal)"), b->number); |
| 322 | else |
| 323 | printf_filtered (_("Catchpoint %d (standard signals)"), b->number); |
| 324 | } |
| 325 | |
| 326 | /* Implement the "print_recreate" breakpoint_ops method for signal |
| 327 | catchpoints. */ |
| 328 | |
| 329 | static void |
| 330 | signal_catchpoint_print_recreate (struct breakpoint *b, struct ui_file *fp) |
| 331 | { |
| 332 | struct signal_catchpoint *c = (struct signal_catchpoint *) b; |
| 333 | |
| 334 | fprintf_unfiltered (fp, "catch signal"); |
| 335 | |
| 336 | if (c->signals_to_be_caught) |
| 337 | { |
| 338 | int i; |
| 339 | gdb_signal_type iter; |
| 340 | |
| 341 | for (i = 0; |
| 342 | VEC_iterate (gdb_signal_type, c->signals_to_be_caught, i, iter); |
| 343 | i++) |
| 344 | fprintf_unfiltered (fp, " %s", signal_to_name_or_int (iter)); |
| 345 | } |
| 346 | else if (c->catch_all) |
| 347 | fprintf_unfiltered (fp, " all"); |
| 348 | fputc_unfiltered ('\n', fp); |
| 349 | } |
| 350 | |
| 351 | /* Implement the "explains_signal" breakpoint_ops method for signal |
| 352 | catchpoints. */ |
| 353 | |
| 354 | static int |
| 355 | signal_catchpoint_explains_signal (struct breakpoint *b, enum gdb_signal sig) |
| 356 | { |
| 357 | return 1; |
| 358 | } |
| 359 | |
| 360 | /* Create a new signal catchpoint. TEMPFLAG is true if this should be |
| 361 | a temporary catchpoint. FILTER is the list of signals to catch; it |
| 362 | can be NULL, meaning all signals. CATCH_ALL is a flag indicating |
| 363 | whether signals used internally by gdb should be caught; it is only |
| 364 | valid if FILTER is NULL. If FILTER is NULL and CATCH_ALL is zero, |
| 365 | then internal signals like SIGTRAP are not caught. */ |
| 366 | |
| 367 | static void |
| 368 | create_signal_catchpoint (int tempflag, VEC (gdb_signal_type) *filter, |
| 369 | int catch_all) |
| 370 | { |
| 371 | struct signal_catchpoint *c; |
| 372 | struct gdbarch *gdbarch = get_current_arch (); |
| 373 | |
| 374 | c = new signal_catchpoint (); |
| 375 | init_catchpoint (&c->base, gdbarch, tempflag, NULL, &signal_catchpoint_ops); |
| 376 | c->signals_to_be_caught = filter; |
| 377 | c->catch_all = catch_all; |
| 378 | |
| 379 | install_breakpoint (0, &c->base, 1); |
| 380 | } |
| 381 | |
| 382 | |
| 383 | /* Splits the argument using space as delimiter. Returns an xmalloc'd |
| 384 | filter list, or NULL if no filtering is required. */ |
| 385 | |
| 386 | static VEC (gdb_signal_type) * |
| 387 | catch_signal_split_args (char *arg, int *catch_all) |
| 388 | { |
| 389 | VEC (gdb_signal_type) *result = NULL; |
| 390 | struct cleanup *cleanup = make_cleanup (VEC_cleanup (gdb_signal_type), |
| 391 | &result); |
| 392 | int first = 1; |
| 393 | |
| 394 | while (*arg != '\0') |
| 395 | { |
| 396 | int num; |
| 397 | gdb_signal_type signal_number; |
| 398 | char *one_arg, *endptr; |
| 399 | struct cleanup *inner_cleanup; |
| 400 | |
| 401 | one_arg = extract_arg (&arg); |
| 402 | if (one_arg == NULL) |
| 403 | break; |
| 404 | inner_cleanup = make_cleanup (xfree, one_arg); |
| 405 | |
| 406 | /* Check for the special flag "all". */ |
| 407 | if (strcmp (one_arg, "all") == 0) |
| 408 | { |
| 409 | arg = skip_spaces (arg); |
| 410 | if (*arg != '\0' || !first) |
| 411 | error (_("'all' cannot be caught with other signals")); |
| 412 | *catch_all = 1; |
| 413 | gdb_assert (result == NULL); |
| 414 | do_cleanups (inner_cleanup); |
| 415 | discard_cleanups (cleanup); |
| 416 | return NULL; |
| 417 | } |
| 418 | |
| 419 | first = 0; |
| 420 | |
| 421 | /* Check if the user provided a signal name or a number. */ |
| 422 | num = (int) strtol (one_arg, &endptr, 0); |
| 423 | if (*endptr == '\0') |
| 424 | signal_number = gdb_signal_from_command (num); |
| 425 | else |
| 426 | { |
| 427 | signal_number = gdb_signal_from_name (one_arg); |
| 428 | if (signal_number == GDB_SIGNAL_UNKNOWN) |
| 429 | error (_("Unknown signal name '%s'."), one_arg); |
| 430 | } |
| 431 | |
| 432 | VEC_safe_push (gdb_signal_type, result, signal_number); |
| 433 | do_cleanups (inner_cleanup); |
| 434 | } |
| 435 | |
| 436 | discard_cleanups (cleanup); |
| 437 | return result; |
| 438 | } |
| 439 | |
| 440 | /* Implement the "catch signal" command. */ |
| 441 | |
| 442 | static void |
| 443 | catch_signal_command (char *arg, int from_tty, |
| 444 | struct cmd_list_element *command) |
| 445 | { |
| 446 | int tempflag, catch_all = 0; |
| 447 | VEC (gdb_signal_type) *filter; |
| 448 | |
| 449 | tempflag = get_cmd_context (command) == CATCH_TEMPORARY; |
| 450 | |
| 451 | arg = skip_spaces (arg); |
| 452 | |
| 453 | /* The allowed syntax is: |
| 454 | catch signal |
| 455 | catch signal <name | number> [<name | number> ... <name | number>] |
| 456 | |
| 457 | Let's check if there's a signal name. */ |
| 458 | |
| 459 | if (arg != NULL) |
| 460 | filter = catch_signal_split_args (arg, &catch_all); |
| 461 | else |
| 462 | filter = NULL; |
| 463 | |
| 464 | create_signal_catchpoint (tempflag, filter, catch_all); |
| 465 | } |
| 466 | |
| 467 | static void |
| 468 | initialize_signal_catchpoint_ops (void) |
| 469 | { |
| 470 | struct breakpoint_ops *ops; |
| 471 | |
| 472 | initialize_breakpoint_ops (); |
| 473 | |
| 474 | ops = &signal_catchpoint_ops; |
| 475 | *ops = base_breakpoint_ops; |
| 476 | ops->dtor = signal_catchpoint_dtor; |
| 477 | ops->insert_location = signal_catchpoint_insert_location; |
| 478 | ops->remove_location = signal_catchpoint_remove_location; |
| 479 | ops->breakpoint_hit = signal_catchpoint_breakpoint_hit; |
| 480 | ops->print_it = signal_catchpoint_print_it; |
| 481 | ops->print_one = signal_catchpoint_print_one; |
| 482 | ops->print_mention = signal_catchpoint_print_mention; |
| 483 | ops->print_recreate = signal_catchpoint_print_recreate; |
| 484 | ops->explains_signal = signal_catchpoint_explains_signal; |
| 485 | } |
| 486 | |
| 487 | initialize_file_ftype _initialize_break_catch_sig; |
| 488 | |
| 489 | void |
| 490 | _initialize_break_catch_sig (void) |
| 491 | { |
| 492 | initialize_signal_catchpoint_ops (); |
| 493 | |
| 494 | signal_catch_counts = XCNEWVEC (unsigned int, GDB_SIGNAL_LAST); |
| 495 | |
| 496 | add_catch_command ("signal", _("\ |
| 497 | Catch signals by their names and/or numbers.\n\ |
| 498 | Usage: catch signal [[NAME|NUMBER] [NAME|NUMBER]...|all]\n\ |
| 499 | Arguments say which signals to catch. If no arguments\n\ |
| 500 | are given, every \"normal\" signal will be caught.\n\ |
| 501 | The argument \"all\" means to also catch signals used by GDB.\n\ |
| 502 | Arguments, if given, should be one or more signal names\n\ |
| 503 | (if your system supports that), or signal numbers."), |
| 504 | catch_signal_command, |
| 505 | signal_completer, |
| 506 | CATCH_PERMANENT, |
| 507 | CATCH_TEMPORARY); |
| 508 | } |