| 1 | /* Everything about signal catchpoints, for GDB. |
| 2 | |
| 3 | Copyright (C) 2011-2019 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 | #include "cli/cli-style.h" |
| 32 | |
| 33 | #include <string> |
| 34 | |
| 35 | #define INTERNAL_SIGNAL(x) ((x) == GDB_SIGNAL_TRAP || (x) == GDB_SIGNAL_INT) |
| 36 | |
| 37 | /* An instance of this type is used to represent a signal catchpoint. |
| 38 | A breakpoint is really of this type iff its ops pointer points to |
| 39 | SIGNAL_CATCHPOINT_OPS. */ |
| 40 | |
| 41 | struct signal_catchpoint : public breakpoint |
| 42 | { |
| 43 | /* Signal numbers used for the 'catch signal' feature. If no signal |
| 44 | has been specified for filtering, it is empty. Otherwise, |
| 45 | it holds a list of all signals to be caught. */ |
| 46 | |
| 47 | std::vector<gdb_signal> signals_to_be_caught; |
| 48 | |
| 49 | /* If SIGNALS_TO_BE_CAUGHT is empty, then all "ordinary" signals are |
| 50 | caught. If CATCH_ALL is true, then internal signals are caught |
| 51 | as well. If SIGNALS_TO_BE_CAUGHT is not empty, then this field |
| 52 | is ignored. */ |
| 53 | |
| 54 | bool catch_all; |
| 55 | }; |
| 56 | |
| 57 | /* The breakpoint_ops structure to be used in signal catchpoints. */ |
| 58 | |
| 59 | static struct breakpoint_ops signal_catchpoint_ops; |
| 60 | |
| 61 | /* Count of each signal. */ |
| 62 | |
| 63 | static unsigned int *signal_catch_counts; |
| 64 | |
| 65 | \f |
| 66 | |
| 67 | /* A convenience wrapper for gdb_signal_to_name that returns the |
| 68 | integer value if the name is not known. */ |
| 69 | |
| 70 | static const char * |
| 71 | signal_to_name_or_int (enum gdb_signal sig) |
| 72 | { |
| 73 | const char *result = gdb_signal_to_name (sig); |
| 74 | |
| 75 | if (strcmp (result, "?") == 0) |
| 76 | result = plongest (sig); |
| 77 | |
| 78 | return result; |
| 79 | } |
| 80 | |
| 81 | \f |
| 82 | |
| 83 | /* Implement the "insert_location" breakpoint_ops method for signal |
| 84 | catchpoints. */ |
| 85 | |
| 86 | static int |
| 87 | signal_catchpoint_insert_location (struct bp_location *bl) |
| 88 | { |
| 89 | struct signal_catchpoint *c = (struct signal_catchpoint *) bl->owner; |
| 90 | |
| 91 | if (!c->signals_to_be_caught.empty ()) |
| 92 | { |
| 93 | for (gdb_signal iter : c->signals_to_be_caught) |
| 94 | ++signal_catch_counts[iter]; |
| 95 | } |
| 96 | else |
| 97 | { |
| 98 | for (int i = 0; i < GDB_SIGNAL_LAST; ++i) |
| 99 | { |
| 100 | if (c->catch_all || !INTERNAL_SIGNAL (i)) |
| 101 | ++signal_catch_counts[i]; |
| 102 | } |
| 103 | } |
| 104 | |
| 105 | signal_catch_update (signal_catch_counts); |
| 106 | |
| 107 | return 0; |
| 108 | } |
| 109 | |
| 110 | /* Implement the "remove_location" breakpoint_ops method for signal |
| 111 | catchpoints. */ |
| 112 | |
| 113 | static int |
| 114 | signal_catchpoint_remove_location (struct bp_location *bl, |
| 115 | enum remove_bp_reason reason) |
| 116 | { |
| 117 | struct signal_catchpoint *c = (struct signal_catchpoint *) bl->owner; |
| 118 | |
| 119 | if (!c->signals_to_be_caught.empty ()) |
| 120 | { |
| 121 | for (gdb_signal iter : c->signals_to_be_caught) |
| 122 | { |
| 123 | gdb_assert (signal_catch_counts[iter] > 0); |
| 124 | --signal_catch_counts[iter]; |
| 125 | } |
| 126 | } |
| 127 | else |
| 128 | { |
| 129 | for (int i = 0; i < GDB_SIGNAL_LAST; ++i) |
| 130 | { |
| 131 | if (c->catch_all || !INTERNAL_SIGNAL (i)) |
| 132 | { |
| 133 | gdb_assert (signal_catch_counts[i] > 0); |
| 134 | --signal_catch_counts[i]; |
| 135 | } |
| 136 | } |
| 137 | } |
| 138 | |
| 139 | signal_catch_update (signal_catch_counts); |
| 140 | |
| 141 | return 0; |
| 142 | } |
| 143 | |
| 144 | /* Implement the "breakpoint_hit" breakpoint_ops method for signal |
| 145 | catchpoints. */ |
| 146 | |
| 147 | static int |
| 148 | signal_catchpoint_breakpoint_hit (const struct bp_location *bl, |
| 149 | const address_space *aspace, |
| 150 | CORE_ADDR bp_addr, |
| 151 | const struct target_waitstatus *ws) |
| 152 | { |
| 153 | const struct signal_catchpoint *c |
| 154 | = (const struct signal_catchpoint *) bl->owner; |
| 155 | gdb_signal signal_number; |
| 156 | |
| 157 | if (ws->kind != TARGET_WAITKIND_STOPPED) |
| 158 | return 0; |
| 159 | |
| 160 | signal_number = ws->value.sig; |
| 161 | |
| 162 | /* If we are catching specific signals in this breakpoint, then we |
| 163 | must guarantee that the called signal is the same signal we are |
| 164 | catching. */ |
| 165 | if (!c->signals_to_be_caught.empty ()) |
| 166 | { |
| 167 | for (gdb_signal iter : c->signals_to_be_caught) |
| 168 | if (signal_number == iter) |
| 169 | return 1; |
| 170 | /* Not the same. */ |
| 171 | return 0; |
| 172 | } |
| 173 | else |
| 174 | return c->catch_all || !INTERNAL_SIGNAL (signal_number); |
| 175 | } |
| 176 | |
| 177 | /* Implement the "print_it" breakpoint_ops method for signal |
| 178 | catchpoints. */ |
| 179 | |
| 180 | static enum print_stop_action |
| 181 | signal_catchpoint_print_it (bpstat bs) |
| 182 | { |
| 183 | struct breakpoint *b = bs->breakpoint_at; |
| 184 | ptid_t ptid; |
| 185 | struct target_waitstatus last; |
| 186 | const char *signal_name; |
| 187 | struct ui_out *uiout = current_uiout; |
| 188 | |
| 189 | get_last_target_status (&ptid, &last); |
| 190 | |
| 191 | signal_name = signal_to_name_or_int (last.value.sig); |
| 192 | |
| 193 | annotate_catchpoint (b->number); |
| 194 | maybe_print_thread_hit_breakpoint (uiout); |
| 195 | |
| 196 | printf_filtered (_("Catchpoint %d (signal %s), "), b->number, signal_name); |
| 197 | |
| 198 | return PRINT_SRC_AND_LOC; |
| 199 | } |
| 200 | |
| 201 | /* Implement the "print_one" breakpoint_ops method for signal |
| 202 | catchpoints. */ |
| 203 | |
| 204 | static void |
| 205 | signal_catchpoint_print_one (struct breakpoint *b, |
| 206 | struct bp_location **last_loc) |
| 207 | { |
| 208 | struct signal_catchpoint *c = (struct signal_catchpoint *) b; |
| 209 | struct value_print_options opts; |
| 210 | struct ui_out *uiout = current_uiout; |
| 211 | |
| 212 | get_user_print_options (&opts); |
| 213 | |
| 214 | /* Field 4, the address, is omitted (which makes the columns |
| 215 | not line up too nicely with the headers, but the effect |
| 216 | is relatively readable). */ |
| 217 | if (opts.addressprint) |
| 218 | uiout->field_skip ("addr"); |
| 219 | annotate_field (5); |
| 220 | |
| 221 | if (c->signals_to_be_caught.size () > 1) |
| 222 | uiout->text ("signals \""); |
| 223 | else |
| 224 | uiout->text ("signal \""); |
| 225 | |
| 226 | if (!c->signals_to_be_caught.empty ()) |
| 227 | { |
| 228 | std::string text; |
| 229 | |
| 230 | bool first = true; |
| 231 | for (gdb_signal iter : c->signals_to_be_caught) |
| 232 | { |
| 233 | const char *name = signal_to_name_or_int (iter); |
| 234 | |
| 235 | if (!first) |
| 236 | text += " "; |
| 237 | first = false; |
| 238 | |
| 239 | text += name; |
| 240 | } |
| 241 | uiout->field_string ("what", text.c_str ()); |
| 242 | } |
| 243 | else |
| 244 | uiout->field_string ("what", |
| 245 | c->catch_all ? "<any signal>" : "<standard signals>", |
| 246 | metadata_style.style ()); |
| 247 | uiout->text ("\" "); |
| 248 | |
| 249 | if (uiout->is_mi_like_p ()) |
| 250 | uiout->field_string ("catch-type", "signal"); |
| 251 | } |
| 252 | |
| 253 | /* Implement the "print_mention" breakpoint_ops method for signal |
| 254 | catchpoints. */ |
| 255 | |
| 256 | static void |
| 257 | signal_catchpoint_print_mention (struct breakpoint *b) |
| 258 | { |
| 259 | struct signal_catchpoint *c = (struct signal_catchpoint *) b; |
| 260 | |
| 261 | if (!c->signals_to_be_caught.empty ()) |
| 262 | { |
| 263 | if (c->signals_to_be_caught.size () > 1) |
| 264 | printf_filtered (_("Catchpoint %d (signals"), b->number); |
| 265 | else |
| 266 | printf_filtered (_("Catchpoint %d (signal"), b->number); |
| 267 | |
| 268 | for (gdb_signal iter : c->signals_to_be_caught) |
| 269 | { |
| 270 | const char *name = signal_to_name_or_int (iter); |
| 271 | |
| 272 | printf_filtered (" %s", name); |
| 273 | } |
| 274 | printf_filtered (")"); |
| 275 | } |
| 276 | else if (c->catch_all) |
| 277 | printf_filtered (_("Catchpoint %d (any signal)"), b->number); |
| 278 | else |
| 279 | printf_filtered (_("Catchpoint %d (standard signals)"), b->number); |
| 280 | } |
| 281 | |
| 282 | /* Implement the "print_recreate" breakpoint_ops method for signal |
| 283 | catchpoints. */ |
| 284 | |
| 285 | static void |
| 286 | signal_catchpoint_print_recreate (struct breakpoint *b, struct ui_file *fp) |
| 287 | { |
| 288 | struct signal_catchpoint *c = (struct signal_catchpoint *) b; |
| 289 | |
| 290 | fprintf_unfiltered (fp, "catch signal"); |
| 291 | |
| 292 | if (!c->signals_to_be_caught.empty ()) |
| 293 | { |
| 294 | for (gdb_signal iter : c->signals_to_be_caught) |
| 295 | fprintf_unfiltered (fp, " %s", signal_to_name_or_int (iter)); |
| 296 | } |
| 297 | else if (c->catch_all) |
| 298 | fprintf_unfiltered (fp, " all"); |
| 299 | fputc_unfiltered ('\n', fp); |
| 300 | } |
| 301 | |
| 302 | /* Implement the "explains_signal" breakpoint_ops method for signal |
| 303 | catchpoints. */ |
| 304 | |
| 305 | static int |
| 306 | signal_catchpoint_explains_signal (struct breakpoint *b, enum gdb_signal sig) |
| 307 | { |
| 308 | return 1; |
| 309 | } |
| 310 | |
| 311 | /* Create a new signal catchpoint. TEMPFLAG is true if this should be |
| 312 | a temporary catchpoint. FILTER is the list of signals to catch; it |
| 313 | can be empty, meaning all signals. CATCH_ALL is a flag indicating |
| 314 | whether signals used internally by gdb should be caught; it is only |
| 315 | valid if FILTER is NULL. If FILTER is empty and CATCH_ALL is zero, |
| 316 | then internal signals like SIGTRAP are not caught. */ |
| 317 | |
| 318 | static void |
| 319 | create_signal_catchpoint (int tempflag, std::vector<gdb_signal> &&filter, |
| 320 | bool catch_all) |
| 321 | { |
| 322 | struct gdbarch *gdbarch = get_current_arch (); |
| 323 | |
| 324 | std::unique_ptr<signal_catchpoint> c (new signal_catchpoint ()); |
| 325 | init_catchpoint (c.get (), gdbarch, tempflag, NULL, &signal_catchpoint_ops); |
| 326 | c->signals_to_be_caught = std::move (filter); |
| 327 | c->catch_all = catch_all; |
| 328 | |
| 329 | install_breakpoint (0, std::move (c), 1); |
| 330 | } |
| 331 | |
| 332 | |
| 333 | /* Splits the argument using space as delimiter. Returns a filter |
| 334 | list, which is empty if no filtering is required. */ |
| 335 | |
| 336 | static std::vector<gdb_signal> |
| 337 | catch_signal_split_args (const char *arg, bool *catch_all) |
| 338 | { |
| 339 | std::vector<gdb_signal> result; |
| 340 | bool first = true; |
| 341 | |
| 342 | while (*arg != '\0') |
| 343 | { |
| 344 | int num; |
| 345 | gdb_signal signal_number; |
| 346 | char *endptr; |
| 347 | |
| 348 | std::string one_arg = extract_arg (&arg); |
| 349 | if (one_arg.empty ()) |
| 350 | break; |
| 351 | |
| 352 | /* Check for the special flag "all". */ |
| 353 | if (one_arg == "all") |
| 354 | { |
| 355 | arg = skip_spaces (arg); |
| 356 | if (*arg != '\0' || !first) |
| 357 | error (_("'all' cannot be caught with other signals")); |
| 358 | *catch_all = true; |
| 359 | gdb_assert (result.empty ()); |
| 360 | return result; |
| 361 | } |
| 362 | |
| 363 | first = false; |
| 364 | |
| 365 | /* Check if the user provided a signal name or a number. */ |
| 366 | num = (int) strtol (one_arg.c_str (), &endptr, 0); |
| 367 | if (*endptr == '\0') |
| 368 | signal_number = gdb_signal_from_command (num); |
| 369 | else |
| 370 | { |
| 371 | signal_number = gdb_signal_from_name (one_arg.c_str ()); |
| 372 | if (signal_number == GDB_SIGNAL_UNKNOWN) |
| 373 | error (_("Unknown signal name '%s'."), one_arg.c_str ()); |
| 374 | } |
| 375 | |
| 376 | result.push_back (signal_number); |
| 377 | } |
| 378 | |
| 379 | result.shrink_to_fit (); |
| 380 | return result; |
| 381 | } |
| 382 | |
| 383 | /* Implement the "catch signal" command. */ |
| 384 | |
| 385 | static void |
| 386 | catch_signal_command (const char *arg, int from_tty, |
| 387 | struct cmd_list_element *command) |
| 388 | { |
| 389 | int tempflag; |
| 390 | bool catch_all = false; |
| 391 | std::vector<gdb_signal> filter; |
| 392 | |
| 393 | tempflag = get_cmd_context (command) == CATCH_TEMPORARY; |
| 394 | |
| 395 | arg = skip_spaces (arg); |
| 396 | |
| 397 | /* The allowed syntax is: |
| 398 | catch signal |
| 399 | catch signal <name | number> [<name | number> ... <name | number>] |
| 400 | |
| 401 | Let's check if there's a signal name. */ |
| 402 | |
| 403 | if (arg != NULL) |
| 404 | filter = catch_signal_split_args (arg, &catch_all); |
| 405 | |
| 406 | create_signal_catchpoint (tempflag, std::move (filter), catch_all); |
| 407 | } |
| 408 | |
| 409 | static void |
| 410 | initialize_signal_catchpoint_ops (void) |
| 411 | { |
| 412 | struct breakpoint_ops *ops; |
| 413 | |
| 414 | initialize_breakpoint_ops (); |
| 415 | |
| 416 | ops = &signal_catchpoint_ops; |
| 417 | *ops = base_breakpoint_ops; |
| 418 | ops->insert_location = signal_catchpoint_insert_location; |
| 419 | ops->remove_location = signal_catchpoint_remove_location; |
| 420 | ops->breakpoint_hit = signal_catchpoint_breakpoint_hit; |
| 421 | ops->print_it = signal_catchpoint_print_it; |
| 422 | ops->print_one = signal_catchpoint_print_one; |
| 423 | ops->print_mention = signal_catchpoint_print_mention; |
| 424 | ops->print_recreate = signal_catchpoint_print_recreate; |
| 425 | ops->explains_signal = signal_catchpoint_explains_signal; |
| 426 | } |
| 427 | |
| 428 | void |
| 429 | _initialize_break_catch_sig (void) |
| 430 | { |
| 431 | initialize_signal_catchpoint_ops (); |
| 432 | |
| 433 | signal_catch_counts = XCNEWVEC (unsigned int, GDB_SIGNAL_LAST); |
| 434 | |
| 435 | add_catch_command ("signal", _("\ |
| 436 | Catch signals by their names and/or numbers.\n\ |
| 437 | Usage: catch signal [[NAME|NUMBER] [NAME|NUMBER]...|all]\n\ |
| 438 | Arguments say which signals to catch. If no arguments\n\ |
| 439 | are given, every \"normal\" signal will be caught.\n\ |
| 440 | The argument \"all\" means to also catch signals used by GDB.\n\ |
| 441 | Arguments, if given, should be one or more signal names\n\ |
| 442 | (if your system supports that), or signal numbers."), |
| 443 | catch_signal_command, |
| 444 | signal_completer, |
| 445 | CATCH_PERMANENT, |
| 446 | CATCH_TEMPORARY); |
| 447 | } |