| 1 | /* Target-struct-independent code to start (run) and stop an inferior |
| 2 | process. |
| 3 | |
| 4 | Copyright (C) 1986-2015 Free Software Foundation, Inc. |
| 5 | |
| 6 | This file is part of GDB. |
| 7 | |
| 8 | This program is free software; you can redistribute it and/or modify |
| 9 | it under the terms of the GNU General Public License as published by |
| 10 | the Free Software Foundation; either version 3 of the License, or |
| 11 | (at your option) any later version. |
| 12 | |
| 13 | This program is distributed in the hope that it will be useful, |
| 14 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | GNU General Public License for more details. |
| 17 | |
| 18 | You should have received a copy of the GNU General Public License |
| 19 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 20 | |
| 21 | #include "defs.h" |
| 22 | #include "infrun.h" |
| 23 | #include <ctype.h> |
| 24 | #include "symtab.h" |
| 25 | #include "frame.h" |
| 26 | #include "inferior.h" |
| 27 | #include "breakpoint.h" |
| 28 | #include "gdb_wait.h" |
| 29 | #include "gdbcore.h" |
| 30 | #include "gdbcmd.h" |
| 31 | #include "cli/cli-script.h" |
| 32 | #include "target.h" |
| 33 | #include "gdbthread.h" |
| 34 | #include "annotate.h" |
| 35 | #include "symfile.h" |
| 36 | #include "top.h" |
| 37 | #include <signal.h> |
| 38 | #include "inf-loop.h" |
| 39 | #include "regcache.h" |
| 40 | #include "value.h" |
| 41 | #include "observer.h" |
| 42 | #include "language.h" |
| 43 | #include "solib.h" |
| 44 | #include "main.h" |
| 45 | #include "dictionary.h" |
| 46 | #include "block.h" |
| 47 | #include "mi/mi-common.h" |
| 48 | #include "event-top.h" |
| 49 | #include "record.h" |
| 50 | #include "record-full.h" |
| 51 | #include "inline-frame.h" |
| 52 | #include "jit.h" |
| 53 | #include "tracepoint.h" |
| 54 | #include "continuations.h" |
| 55 | #include "interps.h" |
| 56 | #include "skip.h" |
| 57 | #include "probe.h" |
| 58 | #include "objfiles.h" |
| 59 | #include "completer.h" |
| 60 | #include "target-descriptions.h" |
| 61 | #include "target-dcache.h" |
| 62 | #include "terminal.h" |
| 63 | #include "solist.h" |
| 64 | |
| 65 | /* Prototypes for local functions */ |
| 66 | |
| 67 | static void signals_info (char *, int); |
| 68 | |
| 69 | static void handle_command (char *, int); |
| 70 | |
| 71 | static void sig_print_info (enum gdb_signal); |
| 72 | |
| 73 | static void sig_print_header (void); |
| 74 | |
| 75 | static void resume_cleanups (void *); |
| 76 | |
| 77 | static int hook_stop_stub (void *); |
| 78 | |
| 79 | static int restore_selected_frame (void *); |
| 80 | |
| 81 | static int follow_fork (void); |
| 82 | |
| 83 | static int follow_fork_inferior (int follow_child, int detach_fork); |
| 84 | |
| 85 | static void follow_inferior_reset_breakpoints (void); |
| 86 | |
| 87 | static void set_schedlock_func (char *args, int from_tty, |
| 88 | struct cmd_list_element *c); |
| 89 | |
| 90 | static int currently_stepping (struct thread_info *tp); |
| 91 | |
| 92 | void _initialize_infrun (void); |
| 93 | |
| 94 | void nullify_last_target_wait_ptid (void); |
| 95 | |
| 96 | static void insert_hp_step_resume_breakpoint_at_frame (struct frame_info *); |
| 97 | |
| 98 | static void insert_step_resume_breakpoint_at_caller (struct frame_info *); |
| 99 | |
| 100 | static void insert_longjmp_resume_breakpoint (struct gdbarch *, CORE_ADDR); |
| 101 | |
| 102 | static int maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc); |
| 103 | |
| 104 | /* When set, stop the 'step' command if we enter a function which has |
| 105 | no line number information. The normal behavior is that we step |
| 106 | over such function. */ |
| 107 | int step_stop_if_no_debug = 0; |
| 108 | static void |
| 109 | show_step_stop_if_no_debug (struct ui_file *file, int from_tty, |
| 110 | struct cmd_list_element *c, const char *value) |
| 111 | { |
| 112 | fprintf_filtered (file, _("Mode of the step operation is %s.\n"), value); |
| 113 | } |
| 114 | |
| 115 | /* In asynchronous mode, but simulating synchronous execution. */ |
| 116 | |
| 117 | int sync_execution = 0; |
| 118 | |
| 119 | /* proceed and normal_stop use this to notify the user when the |
| 120 | inferior stopped in a different thread than it had been running |
| 121 | in. */ |
| 122 | |
| 123 | static ptid_t previous_inferior_ptid; |
| 124 | |
| 125 | /* If set (default for legacy reasons), when following a fork, GDB |
| 126 | will detach from one of the fork branches, child or parent. |
| 127 | Exactly which branch is detached depends on 'set follow-fork-mode' |
| 128 | setting. */ |
| 129 | |
| 130 | static int detach_fork = 1; |
| 131 | |
| 132 | int debug_displaced = 0; |
| 133 | static void |
| 134 | show_debug_displaced (struct ui_file *file, int from_tty, |
| 135 | struct cmd_list_element *c, const char *value) |
| 136 | { |
| 137 | fprintf_filtered (file, _("Displace stepping debugging is %s.\n"), value); |
| 138 | } |
| 139 | |
| 140 | unsigned int debug_infrun = 0; |
| 141 | static void |
| 142 | show_debug_infrun (struct ui_file *file, int from_tty, |
| 143 | struct cmd_list_element *c, const char *value) |
| 144 | { |
| 145 | fprintf_filtered (file, _("Inferior debugging is %s.\n"), value); |
| 146 | } |
| 147 | |
| 148 | |
| 149 | /* Support for disabling address space randomization. */ |
| 150 | |
| 151 | int disable_randomization = 1; |
| 152 | |
| 153 | static void |
| 154 | show_disable_randomization (struct ui_file *file, int from_tty, |
| 155 | struct cmd_list_element *c, const char *value) |
| 156 | { |
| 157 | if (target_supports_disable_randomization ()) |
| 158 | fprintf_filtered (file, |
| 159 | _("Disabling randomization of debuggee's " |
| 160 | "virtual address space is %s.\n"), |
| 161 | value); |
| 162 | else |
| 163 | fputs_filtered (_("Disabling randomization of debuggee's " |
| 164 | "virtual address space is unsupported on\n" |
| 165 | "this platform.\n"), file); |
| 166 | } |
| 167 | |
| 168 | static void |
| 169 | set_disable_randomization (char *args, int from_tty, |
| 170 | struct cmd_list_element *c) |
| 171 | { |
| 172 | if (!target_supports_disable_randomization ()) |
| 173 | error (_("Disabling randomization of debuggee's " |
| 174 | "virtual address space is unsupported on\n" |
| 175 | "this platform.")); |
| 176 | } |
| 177 | |
| 178 | /* User interface for non-stop mode. */ |
| 179 | |
| 180 | int non_stop = 0; |
| 181 | static int non_stop_1 = 0; |
| 182 | |
| 183 | static void |
| 184 | set_non_stop (char *args, int from_tty, |
| 185 | struct cmd_list_element *c) |
| 186 | { |
| 187 | if (target_has_execution) |
| 188 | { |
| 189 | non_stop_1 = non_stop; |
| 190 | error (_("Cannot change this setting while the inferior is running.")); |
| 191 | } |
| 192 | |
| 193 | non_stop = non_stop_1; |
| 194 | } |
| 195 | |
| 196 | static void |
| 197 | show_non_stop (struct ui_file *file, int from_tty, |
| 198 | struct cmd_list_element *c, const char *value) |
| 199 | { |
| 200 | fprintf_filtered (file, |
| 201 | _("Controlling the inferior in non-stop mode is %s.\n"), |
| 202 | value); |
| 203 | } |
| 204 | |
| 205 | /* "Observer mode" is somewhat like a more extreme version of |
| 206 | non-stop, in which all GDB operations that might affect the |
| 207 | target's execution have been disabled. */ |
| 208 | |
| 209 | int observer_mode = 0; |
| 210 | static int observer_mode_1 = 0; |
| 211 | |
| 212 | static void |
| 213 | set_observer_mode (char *args, int from_tty, |
| 214 | struct cmd_list_element *c) |
| 215 | { |
| 216 | if (target_has_execution) |
| 217 | { |
| 218 | observer_mode_1 = observer_mode; |
| 219 | error (_("Cannot change this setting while the inferior is running.")); |
| 220 | } |
| 221 | |
| 222 | observer_mode = observer_mode_1; |
| 223 | |
| 224 | may_write_registers = !observer_mode; |
| 225 | may_write_memory = !observer_mode; |
| 226 | may_insert_breakpoints = !observer_mode; |
| 227 | may_insert_tracepoints = !observer_mode; |
| 228 | /* We can insert fast tracepoints in or out of observer mode, |
| 229 | but enable them if we're going into this mode. */ |
| 230 | if (observer_mode) |
| 231 | may_insert_fast_tracepoints = 1; |
| 232 | may_stop = !observer_mode; |
| 233 | update_target_permissions (); |
| 234 | |
| 235 | /* Going *into* observer mode we must force non-stop, then |
| 236 | going out we leave it that way. */ |
| 237 | if (observer_mode) |
| 238 | { |
| 239 | pagination_enabled = 0; |
| 240 | non_stop = non_stop_1 = 1; |
| 241 | } |
| 242 | |
| 243 | if (from_tty) |
| 244 | printf_filtered (_("Observer mode is now %s.\n"), |
| 245 | (observer_mode ? "on" : "off")); |
| 246 | } |
| 247 | |
| 248 | static void |
| 249 | show_observer_mode (struct ui_file *file, int from_tty, |
| 250 | struct cmd_list_element *c, const char *value) |
| 251 | { |
| 252 | fprintf_filtered (file, _("Observer mode is %s.\n"), value); |
| 253 | } |
| 254 | |
| 255 | /* This updates the value of observer mode based on changes in |
| 256 | permissions. Note that we are deliberately ignoring the values of |
| 257 | may-write-registers and may-write-memory, since the user may have |
| 258 | reason to enable these during a session, for instance to turn on a |
| 259 | debugging-related global. */ |
| 260 | |
| 261 | void |
| 262 | update_observer_mode (void) |
| 263 | { |
| 264 | int newval; |
| 265 | |
| 266 | newval = (!may_insert_breakpoints |
| 267 | && !may_insert_tracepoints |
| 268 | && may_insert_fast_tracepoints |
| 269 | && !may_stop |
| 270 | && non_stop); |
| 271 | |
| 272 | /* Let the user know if things change. */ |
| 273 | if (newval != observer_mode) |
| 274 | printf_filtered (_("Observer mode is now %s.\n"), |
| 275 | (newval ? "on" : "off")); |
| 276 | |
| 277 | observer_mode = observer_mode_1 = newval; |
| 278 | } |
| 279 | |
| 280 | /* Tables of how to react to signals; the user sets them. */ |
| 281 | |
| 282 | static unsigned char *signal_stop; |
| 283 | static unsigned char *signal_print; |
| 284 | static unsigned char *signal_program; |
| 285 | |
| 286 | /* Table of signals that are registered with "catch signal". A |
| 287 | non-zero entry indicates that the signal is caught by some "catch |
| 288 | signal" command. This has size GDB_SIGNAL_LAST, to accommodate all |
| 289 | signals. */ |
| 290 | static unsigned char *signal_catch; |
| 291 | |
| 292 | /* Table of signals that the target may silently handle. |
| 293 | This is automatically determined from the flags above, |
| 294 | and simply cached here. */ |
| 295 | static unsigned char *signal_pass; |
| 296 | |
| 297 | #define SET_SIGS(nsigs,sigs,flags) \ |
| 298 | do { \ |
| 299 | int signum = (nsigs); \ |
| 300 | while (signum-- > 0) \ |
| 301 | if ((sigs)[signum]) \ |
| 302 | (flags)[signum] = 1; \ |
| 303 | } while (0) |
| 304 | |
| 305 | #define UNSET_SIGS(nsigs,sigs,flags) \ |
| 306 | do { \ |
| 307 | int signum = (nsigs); \ |
| 308 | while (signum-- > 0) \ |
| 309 | if ((sigs)[signum]) \ |
| 310 | (flags)[signum] = 0; \ |
| 311 | } while (0) |
| 312 | |
| 313 | /* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of |
| 314 | this function is to avoid exporting `signal_program'. */ |
| 315 | |
| 316 | void |
| 317 | update_signals_program_target (void) |
| 318 | { |
| 319 | target_program_signals ((int) GDB_SIGNAL_LAST, signal_program); |
| 320 | } |
| 321 | |
| 322 | /* Value to pass to target_resume() to cause all threads to resume. */ |
| 323 | |
| 324 | #define RESUME_ALL minus_one_ptid |
| 325 | |
| 326 | /* Command list pointer for the "stop" placeholder. */ |
| 327 | |
| 328 | static struct cmd_list_element *stop_command; |
| 329 | |
| 330 | /* Nonzero if we want to give control to the user when we're notified |
| 331 | of shared library events by the dynamic linker. */ |
| 332 | int stop_on_solib_events; |
| 333 | |
| 334 | /* Enable or disable optional shared library event breakpoints |
| 335 | as appropriate when the above flag is changed. */ |
| 336 | |
| 337 | static void |
| 338 | set_stop_on_solib_events (char *args, int from_tty, struct cmd_list_element *c) |
| 339 | { |
| 340 | update_solib_breakpoints (); |
| 341 | } |
| 342 | |
| 343 | static void |
| 344 | show_stop_on_solib_events (struct ui_file *file, int from_tty, |
| 345 | struct cmd_list_element *c, const char *value) |
| 346 | { |
| 347 | fprintf_filtered (file, _("Stopping for shared library events is %s.\n"), |
| 348 | value); |
| 349 | } |
| 350 | |
| 351 | /* Nonzero means expecting a trace trap |
| 352 | and should stop the inferior and return silently when it happens. */ |
| 353 | |
| 354 | int stop_after_trap; |
| 355 | |
| 356 | /* Nonzero after stop if current stack frame should be printed. */ |
| 357 | |
| 358 | static int stop_print_frame; |
| 359 | |
| 360 | /* This is a cached copy of the pid/waitstatus of the last event |
| 361 | returned by target_wait()/deprecated_target_wait_hook(). This |
| 362 | information is returned by get_last_target_status(). */ |
| 363 | static ptid_t target_last_wait_ptid; |
| 364 | static struct target_waitstatus target_last_waitstatus; |
| 365 | |
| 366 | static void context_switch (ptid_t ptid); |
| 367 | |
| 368 | void init_thread_stepping_state (struct thread_info *tss); |
| 369 | |
| 370 | static const char follow_fork_mode_child[] = "child"; |
| 371 | static const char follow_fork_mode_parent[] = "parent"; |
| 372 | |
| 373 | static const char *const follow_fork_mode_kind_names[] = { |
| 374 | follow_fork_mode_child, |
| 375 | follow_fork_mode_parent, |
| 376 | NULL |
| 377 | }; |
| 378 | |
| 379 | static const char *follow_fork_mode_string = follow_fork_mode_parent; |
| 380 | static void |
| 381 | show_follow_fork_mode_string (struct ui_file *file, int from_tty, |
| 382 | struct cmd_list_element *c, const char *value) |
| 383 | { |
| 384 | fprintf_filtered (file, |
| 385 | _("Debugger response to a program " |
| 386 | "call of fork or vfork is \"%s\".\n"), |
| 387 | value); |
| 388 | } |
| 389 | \f |
| 390 | |
| 391 | /* Handle changes to the inferior list based on the type of fork, |
| 392 | which process is being followed, and whether the other process |
| 393 | should be detached. On entry inferior_ptid must be the ptid of |
| 394 | the fork parent. At return inferior_ptid is the ptid of the |
| 395 | followed inferior. */ |
| 396 | |
| 397 | static int |
| 398 | follow_fork_inferior (int follow_child, int detach_fork) |
| 399 | { |
| 400 | int has_vforked; |
| 401 | ptid_t parent_ptid, child_ptid; |
| 402 | |
| 403 | has_vforked = (inferior_thread ()->pending_follow.kind |
| 404 | == TARGET_WAITKIND_VFORKED); |
| 405 | parent_ptid = inferior_ptid; |
| 406 | child_ptid = inferior_thread ()->pending_follow.value.related_pid; |
| 407 | |
| 408 | if (has_vforked |
| 409 | && !non_stop /* Non-stop always resumes both branches. */ |
| 410 | && (!target_is_async_p () || sync_execution) |
| 411 | && !(follow_child || detach_fork || sched_multi)) |
| 412 | { |
| 413 | /* The parent stays blocked inside the vfork syscall until the |
| 414 | child execs or exits. If we don't let the child run, then |
| 415 | the parent stays blocked. If we're telling the parent to run |
| 416 | in the foreground, the user will not be able to ctrl-c to get |
| 417 | back the terminal, effectively hanging the debug session. */ |
| 418 | fprintf_filtered (gdb_stderr, _("\ |
| 419 | Can not resume the parent process over vfork in the foreground while\n\ |
| 420 | holding the child stopped. Try \"set detach-on-fork\" or \ |
| 421 | \"set schedule-multiple\".\n")); |
| 422 | /* FIXME output string > 80 columns. */ |
| 423 | return 1; |
| 424 | } |
| 425 | |
| 426 | if (!follow_child) |
| 427 | { |
| 428 | /* Detach new forked process? */ |
| 429 | if (detach_fork) |
| 430 | { |
| 431 | struct cleanup *old_chain; |
| 432 | |
| 433 | /* Before detaching from the child, remove all breakpoints |
| 434 | from it. If we forked, then this has already been taken |
| 435 | care of by infrun.c. If we vforked however, any |
| 436 | breakpoint inserted in the parent is visible in the |
| 437 | child, even those added while stopped in a vfork |
| 438 | catchpoint. This will remove the breakpoints from the |
| 439 | parent also, but they'll be reinserted below. */ |
| 440 | if (has_vforked) |
| 441 | { |
| 442 | /* Keep breakpoints list in sync. */ |
| 443 | remove_breakpoints_pid (ptid_get_pid (inferior_ptid)); |
| 444 | } |
| 445 | |
| 446 | if (info_verbose || debug_infrun) |
| 447 | { |
| 448 | /* Ensure that we have a process ptid. */ |
| 449 | ptid_t process_ptid = pid_to_ptid (ptid_get_pid (child_ptid)); |
| 450 | |
| 451 | target_terminal_ours_for_output (); |
| 452 | fprintf_filtered (gdb_stdlog, |
| 453 | _("Detaching after %s from child %s.\n"), |
| 454 | has_vforked ? "vfork" : "fork", |
| 455 | target_pid_to_str (process_ptid)); |
| 456 | } |
| 457 | } |
| 458 | else |
| 459 | { |
| 460 | struct inferior *parent_inf, *child_inf; |
| 461 | struct cleanup *old_chain; |
| 462 | |
| 463 | /* Add process to GDB's tables. */ |
| 464 | child_inf = add_inferior (ptid_get_pid (child_ptid)); |
| 465 | |
| 466 | parent_inf = current_inferior (); |
| 467 | child_inf->attach_flag = parent_inf->attach_flag; |
| 468 | copy_terminal_info (child_inf, parent_inf); |
| 469 | child_inf->gdbarch = parent_inf->gdbarch; |
| 470 | copy_inferior_target_desc_info (child_inf, parent_inf); |
| 471 | |
| 472 | old_chain = save_inferior_ptid (); |
| 473 | save_current_program_space (); |
| 474 | |
| 475 | inferior_ptid = child_ptid; |
| 476 | add_thread (inferior_ptid); |
| 477 | child_inf->symfile_flags = SYMFILE_NO_READ; |
| 478 | |
| 479 | /* If this is a vfork child, then the address-space is |
| 480 | shared with the parent. */ |
| 481 | if (has_vforked) |
| 482 | { |
| 483 | child_inf->pspace = parent_inf->pspace; |
| 484 | child_inf->aspace = parent_inf->aspace; |
| 485 | |
| 486 | /* The parent will be frozen until the child is done |
| 487 | with the shared region. Keep track of the |
| 488 | parent. */ |
| 489 | child_inf->vfork_parent = parent_inf; |
| 490 | child_inf->pending_detach = 0; |
| 491 | parent_inf->vfork_child = child_inf; |
| 492 | parent_inf->pending_detach = 0; |
| 493 | } |
| 494 | else |
| 495 | { |
| 496 | child_inf->aspace = new_address_space (); |
| 497 | child_inf->pspace = add_program_space (child_inf->aspace); |
| 498 | child_inf->removable = 1; |
| 499 | set_current_program_space (child_inf->pspace); |
| 500 | clone_program_space (child_inf->pspace, parent_inf->pspace); |
| 501 | |
| 502 | /* Let the shared library layer (e.g., solib-svr4) learn |
| 503 | about this new process, relocate the cloned exec, pull |
| 504 | in shared libraries, and install the solib event |
| 505 | breakpoint. If a "cloned-VM" event was propagated |
| 506 | better throughout the core, this wouldn't be |
| 507 | required. */ |
| 508 | solib_create_inferior_hook (0); |
| 509 | } |
| 510 | |
| 511 | do_cleanups (old_chain); |
| 512 | } |
| 513 | |
| 514 | if (has_vforked) |
| 515 | { |
| 516 | struct inferior *parent_inf; |
| 517 | |
| 518 | parent_inf = current_inferior (); |
| 519 | |
| 520 | /* If we detached from the child, then we have to be careful |
| 521 | to not insert breakpoints in the parent until the child |
| 522 | is done with the shared memory region. However, if we're |
| 523 | staying attached to the child, then we can and should |
| 524 | insert breakpoints, so that we can debug it. A |
| 525 | subsequent child exec or exit is enough to know when does |
| 526 | the child stops using the parent's address space. */ |
| 527 | parent_inf->waiting_for_vfork_done = detach_fork; |
| 528 | parent_inf->pspace->breakpoints_not_allowed = detach_fork; |
| 529 | } |
| 530 | } |
| 531 | else |
| 532 | { |
| 533 | /* Follow the child. */ |
| 534 | struct inferior *parent_inf, *child_inf; |
| 535 | struct program_space *parent_pspace; |
| 536 | |
| 537 | if (info_verbose || debug_infrun) |
| 538 | { |
| 539 | target_terminal_ours_for_output (); |
| 540 | fprintf_filtered (gdb_stdlog, |
| 541 | _("Attaching after %s %s to child %s.\n"), |
| 542 | target_pid_to_str (parent_ptid), |
| 543 | has_vforked ? "vfork" : "fork", |
| 544 | target_pid_to_str (child_ptid)); |
| 545 | } |
| 546 | |
| 547 | /* Add the new inferior first, so that the target_detach below |
| 548 | doesn't unpush the target. */ |
| 549 | |
| 550 | child_inf = add_inferior (ptid_get_pid (child_ptid)); |
| 551 | |
| 552 | parent_inf = current_inferior (); |
| 553 | child_inf->attach_flag = parent_inf->attach_flag; |
| 554 | copy_terminal_info (child_inf, parent_inf); |
| 555 | child_inf->gdbarch = parent_inf->gdbarch; |
| 556 | copy_inferior_target_desc_info (child_inf, parent_inf); |
| 557 | |
| 558 | parent_pspace = parent_inf->pspace; |
| 559 | |
| 560 | /* If we're vforking, we want to hold on to the parent until the |
| 561 | child exits or execs. At child exec or exit time we can |
| 562 | remove the old breakpoints from the parent and detach or |
| 563 | resume debugging it. Otherwise, detach the parent now; we'll |
| 564 | want to reuse it's program/address spaces, but we can't set |
| 565 | them to the child before removing breakpoints from the |
| 566 | parent, otherwise, the breakpoints module could decide to |
| 567 | remove breakpoints from the wrong process (since they'd be |
| 568 | assigned to the same address space). */ |
| 569 | |
| 570 | if (has_vforked) |
| 571 | { |
| 572 | gdb_assert (child_inf->vfork_parent == NULL); |
| 573 | gdb_assert (parent_inf->vfork_child == NULL); |
| 574 | child_inf->vfork_parent = parent_inf; |
| 575 | child_inf->pending_detach = 0; |
| 576 | parent_inf->vfork_child = child_inf; |
| 577 | parent_inf->pending_detach = detach_fork; |
| 578 | parent_inf->waiting_for_vfork_done = 0; |
| 579 | } |
| 580 | else if (detach_fork) |
| 581 | { |
| 582 | if (info_verbose || debug_infrun) |
| 583 | { |
| 584 | /* Ensure that we have a process ptid. */ |
| 585 | ptid_t process_ptid = pid_to_ptid (ptid_get_pid (child_ptid)); |
| 586 | |
| 587 | target_terminal_ours_for_output (); |
| 588 | fprintf_filtered (gdb_stdlog, |
| 589 | _("Detaching after fork from " |
| 590 | "child %s.\n"), |
| 591 | target_pid_to_str (process_ptid)); |
| 592 | } |
| 593 | |
| 594 | target_detach (NULL, 0); |
| 595 | } |
| 596 | |
| 597 | /* Note that the detach above makes PARENT_INF dangling. */ |
| 598 | |
| 599 | /* Add the child thread to the appropriate lists, and switch to |
| 600 | this new thread, before cloning the program space, and |
| 601 | informing the solib layer about this new process. */ |
| 602 | |
| 603 | inferior_ptid = child_ptid; |
| 604 | add_thread (inferior_ptid); |
| 605 | |
| 606 | /* If this is a vfork child, then the address-space is shared |
| 607 | with the parent. If we detached from the parent, then we can |
| 608 | reuse the parent's program/address spaces. */ |
| 609 | if (has_vforked || detach_fork) |
| 610 | { |
| 611 | child_inf->pspace = parent_pspace; |
| 612 | child_inf->aspace = child_inf->pspace->aspace; |
| 613 | } |
| 614 | else |
| 615 | { |
| 616 | child_inf->aspace = new_address_space (); |
| 617 | child_inf->pspace = add_program_space (child_inf->aspace); |
| 618 | child_inf->removable = 1; |
| 619 | child_inf->symfile_flags = SYMFILE_NO_READ; |
| 620 | set_current_program_space (child_inf->pspace); |
| 621 | clone_program_space (child_inf->pspace, parent_pspace); |
| 622 | |
| 623 | /* Let the shared library layer (e.g., solib-svr4) learn |
| 624 | about this new process, relocate the cloned exec, pull in |
| 625 | shared libraries, and install the solib event breakpoint. |
| 626 | If a "cloned-VM" event was propagated better throughout |
| 627 | the core, this wouldn't be required. */ |
| 628 | solib_create_inferior_hook (0); |
| 629 | } |
| 630 | } |
| 631 | |
| 632 | return target_follow_fork (follow_child, detach_fork); |
| 633 | } |
| 634 | |
| 635 | /* Tell the target to follow the fork we're stopped at. Returns true |
| 636 | if the inferior should be resumed; false, if the target for some |
| 637 | reason decided it's best not to resume. */ |
| 638 | |
| 639 | static int |
| 640 | follow_fork (void) |
| 641 | { |
| 642 | int follow_child = (follow_fork_mode_string == follow_fork_mode_child); |
| 643 | int should_resume = 1; |
| 644 | struct thread_info *tp; |
| 645 | |
| 646 | /* Copy user stepping state to the new inferior thread. FIXME: the |
| 647 | followed fork child thread should have a copy of most of the |
| 648 | parent thread structure's run control related fields, not just these. |
| 649 | Initialized to avoid "may be used uninitialized" warnings from gcc. */ |
| 650 | struct breakpoint *step_resume_breakpoint = NULL; |
| 651 | struct breakpoint *exception_resume_breakpoint = NULL; |
| 652 | CORE_ADDR step_range_start = 0; |
| 653 | CORE_ADDR step_range_end = 0; |
| 654 | struct frame_id step_frame_id = { 0 }; |
| 655 | struct interp *command_interp = NULL; |
| 656 | |
| 657 | if (!non_stop) |
| 658 | { |
| 659 | ptid_t wait_ptid; |
| 660 | struct target_waitstatus wait_status; |
| 661 | |
| 662 | /* Get the last target status returned by target_wait(). */ |
| 663 | get_last_target_status (&wait_ptid, &wait_status); |
| 664 | |
| 665 | /* If not stopped at a fork event, then there's nothing else to |
| 666 | do. */ |
| 667 | if (wait_status.kind != TARGET_WAITKIND_FORKED |
| 668 | && wait_status.kind != TARGET_WAITKIND_VFORKED) |
| 669 | return 1; |
| 670 | |
| 671 | /* Check if we switched over from WAIT_PTID, since the event was |
| 672 | reported. */ |
| 673 | if (!ptid_equal (wait_ptid, minus_one_ptid) |
| 674 | && !ptid_equal (inferior_ptid, wait_ptid)) |
| 675 | { |
| 676 | /* We did. Switch back to WAIT_PTID thread, to tell the |
| 677 | target to follow it (in either direction). We'll |
| 678 | afterwards refuse to resume, and inform the user what |
| 679 | happened. */ |
| 680 | switch_to_thread (wait_ptid); |
| 681 | should_resume = 0; |
| 682 | } |
| 683 | } |
| 684 | |
| 685 | tp = inferior_thread (); |
| 686 | |
| 687 | /* If there were any forks/vforks that were caught and are now to be |
| 688 | followed, then do so now. */ |
| 689 | switch (tp->pending_follow.kind) |
| 690 | { |
| 691 | case TARGET_WAITKIND_FORKED: |
| 692 | case TARGET_WAITKIND_VFORKED: |
| 693 | { |
| 694 | ptid_t parent, child; |
| 695 | |
| 696 | /* If the user did a next/step, etc, over a fork call, |
| 697 | preserve the stepping state in the fork child. */ |
| 698 | if (follow_child && should_resume) |
| 699 | { |
| 700 | step_resume_breakpoint = clone_momentary_breakpoint |
| 701 | (tp->control.step_resume_breakpoint); |
| 702 | step_range_start = tp->control.step_range_start; |
| 703 | step_range_end = tp->control.step_range_end; |
| 704 | step_frame_id = tp->control.step_frame_id; |
| 705 | exception_resume_breakpoint |
| 706 | = clone_momentary_breakpoint (tp->control.exception_resume_breakpoint); |
| 707 | command_interp = tp->control.command_interp; |
| 708 | |
| 709 | /* For now, delete the parent's sr breakpoint, otherwise, |
| 710 | parent/child sr breakpoints are considered duplicates, |
| 711 | and the child version will not be installed. Remove |
| 712 | this when the breakpoints module becomes aware of |
| 713 | inferiors and address spaces. */ |
| 714 | delete_step_resume_breakpoint (tp); |
| 715 | tp->control.step_range_start = 0; |
| 716 | tp->control.step_range_end = 0; |
| 717 | tp->control.step_frame_id = null_frame_id; |
| 718 | delete_exception_resume_breakpoint (tp); |
| 719 | tp->control.command_interp = NULL; |
| 720 | } |
| 721 | |
| 722 | parent = inferior_ptid; |
| 723 | child = tp->pending_follow.value.related_pid; |
| 724 | |
| 725 | /* Set up inferior(s) as specified by the caller, and tell the |
| 726 | target to do whatever is necessary to follow either parent |
| 727 | or child. */ |
| 728 | if (follow_fork_inferior (follow_child, detach_fork)) |
| 729 | { |
| 730 | /* Target refused to follow, or there's some other reason |
| 731 | we shouldn't resume. */ |
| 732 | should_resume = 0; |
| 733 | } |
| 734 | else |
| 735 | { |
| 736 | /* This pending follow fork event is now handled, one way |
| 737 | or another. The previous selected thread may be gone |
| 738 | from the lists by now, but if it is still around, need |
| 739 | to clear the pending follow request. */ |
| 740 | tp = find_thread_ptid (parent); |
| 741 | if (tp) |
| 742 | tp->pending_follow.kind = TARGET_WAITKIND_SPURIOUS; |
| 743 | |
| 744 | /* This makes sure we don't try to apply the "Switched |
| 745 | over from WAIT_PID" logic above. */ |
| 746 | nullify_last_target_wait_ptid (); |
| 747 | |
| 748 | /* If we followed the child, switch to it... */ |
| 749 | if (follow_child) |
| 750 | { |
| 751 | switch_to_thread (child); |
| 752 | |
| 753 | /* ... and preserve the stepping state, in case the |
| 754 | user was stepping over the fork call. */ |
| 755 | if (should_resume) |
| 756 | { |
| 757 | tp = inferior_thread (); |
| 758 | tp->control.step_resume_breakpoint |
| 759 | = step_resume_breakpoint; |
| 760 | tp->control.step_range_start = step_range_start; |
| 761 | tp->control.step_range_end = step_range_end; |
| 762 | tp->control.step_frame_id = step_frame_id; |
| 763 | tp->control.exception_resume_breakpoint |
| 764 | = exception_resume_breakpoint; |
| 765 | tp->control.command_interp = command_interp; |
| 766 | } |
| 767 | else |
| 768 | { |
| 769 | /* If we get here, it was because we're trying to |
| 770 | resume from a fork catchpoint, but, the user |
| 771 | has switched threads away from the thread that |
| 772 | forked. In that case, the resume command |
| 773 | issued is most likely not applicable to the |
| 774 | child, so just warn, and refuse to resume. */ |
| 775 | warning (_("Not resuming: switched threads " |
| 776 | "before following fork child.\n")); |
| 777 | } |
| 778 | |
| 779 | /* Reset breakpoints in the child as appropriate. */ |
| 780 | follow_inferior_reset_breakpoints (); |
| 781 | } |
| 782 | else |
| 783 | switch_to_thread (parent); |
| 784 | } |
| 785 | } |
| 786 | break; |
| 787 | case TARGET_WAITKIND_SPURIOUS: |
| 788 | /* Nothing to follow. */ |
| 789 | break; |
| 790 | default: |
| 791 | internal_error (__FILE__, __LINE__, |
| 792 | "Unexpected pending_follow.kind %d\n", |
| 793 | tp->pending_follow.kind); |
| 794 | break; |
| 795 | } |
| 796 | |
| 797 | return should_resume; |
| 798 | } |
| 799 | |
| 800 | static void |
| 801 | follow_inferior_reset_breakpoints (void) |
| 802 | { |
| 803 | struct thread_info *tp = inferior_thread (); |
| 804 | |
| 805 | /* Was there a step_resume breakpoint? (There was if the user |
| 806 | did a "next" at the fork() call.) If so, explicitly reset its |
| 807 | thread number. Cloned step_resume breakpoints are disabled on |
| 808 | creation, so enable it here now that it is associated with the |
| 809 | correct thread. |
| 810 | |
| 811 | step_resumes are a form of bp that are made to be per-thread. |
| 812 | Since we created the step_resume bp when the parent process |
| 813 | was being debugged, and now are switching to the child process, |
| 814 | from the breakpoint package's viewpoint, that's a switch of |
| 815 | "threads". We must update the bp's notion of which thread |
| 816 | it is for, or it'll be ignored when it triggers. */ |
| 817 | |
| 818 | if (tp->control.step_resume_breakpoint) |
| 819 | { |
| 820 | breakpoint_re_set_thread (tp->control.step_resume_breakpoint); |
| 821 | tp->control.step_resume_breakpoint->loc->enabled = 1; |
| 822 | } |
| 823 | |
| 824 | /* Treat exception_resume breakpoints like step_resume breakpoints. */ |
| 825 | if (tp->control.exception_resume_breakpoint) |
| 826 | { |
| 827 | breakpoint_re_set_thread (tp->control.exception_resume_breakpoint); |
| 828 | tp->control.exception_resume_breakpoint->loc->enabled = 1; |
| 829 | } |
| 830 | |
| 831 | /* Reinsert all breakpoints in the child. The user may have set |
| 832 | breakpoints after catching the fork, in which case those |
| 833 | were never set in the child, but only in the parent. This makes |
| 834 | sure the inserted breakpoints match the breakpoint list. */ |
| 835 | |
| 836 | breakpoint_re_set (); |
| 837 | insert_breakpoints (); |
| 838 | } |
| 839 | |
| 840 | /* The child has exited or execed: resume threads of the parent the |
| 841 | user wanted to be executing. */ |
| 842 | |
| 843 | static int |
| 844 | proceed_after_vfork_done (struct thread_info *thread, |
| 845 | void *arg) |
| 846 | { |
| 847 | int pid = * (int *) arg; |
| 848 | |
| 849 | if (ptid_get_pid (thread->ptid) == pid |
| 850 | && is_running (thread->ptid) |
| 851 | && !is_executing (thread->ptid) |
| 852 | && !thread->stop_requested |
| 853 | && thread->suspend.stop_signal == GDB_SIGNAL_0) |
| 854 | { |
| 855 | if (debug_infrun) |
| 856 | fprintf_unfiltered (gdb_stdlog, |
| 857 | "infrun: resuming vfork parent thread %s\n", |
| 858 | target_pid_to_str (thread->ptid)); |
| 859 | |
| 860 | switch_to_thread (thread->ptid); |
| 861 | clear_proceed_status (0); |
| 862 | proceed ((CORE_ADDR) -1, GDB_SIGNAL_DEFAULT); |
| 863 | } |
| 864 | |
| 865 | return 0; |
| 866 | } |
| 867 | |
| 868 | /* Called whenever we notice an exec or exit event, to handle |
| 869 | detaching or resuming a vfork parent. */ |
| 870 | |
| 871 | static void |
| 872 | handle_vfork_child_exec_or_exit (int exec) |
| 873 | { |
| 874 | struct inferior *inf = current_inferior (); |
| 875 | |
| 876 | if (inf->vfork_parent) |
| 877 | { |
| 878 | int resume_parent = -1; |
| 879 | |
| 880 | /* This exec or exit marks the end of the shared memory region |
| 881 | between the parent and the child. If the user wanted to |
| 882 | detach from the parent, now is the time. */ |
| 883 | |
| 884 | if (inf->vfork_parent->pending_detach) |
| 885 | { |
| 886 | struct thread_info *tp; |
| 887 | struct cleanup *old_chain; |
| 888 | struct program_space *pspace; |
| 889 | struct address_space *aspace; |
| 890 | |
| 891 | /* follow-fork child, detach-on-fork on. */ |
| 892 | |
| 893 | inf->vfork_parent->pending_detach = 0; |
| 894 | |
| 895 | if (!exec) |
| 896 | { |
| 897 | /* If we're handling a child exit, then inferior_ptid |
| 898 | points at the inferior's pid, not to a thread. */ |
| 899 | old_chain = save_inferior_ptid (); |
| 900 | save_current_program_space (); |
| 901 | save_current_inferior (); |
| 902 | } |
| 903 | else |
| 904 | old_chain = save_current_space_and_thread (); |
| 905 | |
| 906 | /* We're letting loose of the parent. */ |
| 907 | tp = any_live_thread_of_process (inf->vfork_parent->pid); |
| 908 | switch_to_thread (tp->ptid); |
| 909 | |
| 910 | /* We're about to detach from the parent, which implicitly |
| 911 | removes breakpoints from its address space. There's a |
| 912 | catch here: we want to reuse the spaces for the child, |
| 913 | but, parent/child are still sharing the pspace at this |
| 914 | point, although the exec in reality makes the kernel give |
| 915 | the child a fresh set of new pages. The problem here is |
| 916 | that the breakpoints module being unaware of this, would |
| 917 | likely chose the child process to write to the parent |
| 918 | address space. Swapping the child temporarily away from |
| 919 | the spaces has the desired effect. Yes, this is "sort |
| 920 | of" a hack. */ |
| 921 | |
| 922 | pspace = inf->pspace; |
| 923 | aspace = inf->aspace; |
| 924 | inf->aspace = NULL; |
| 925 | inf->pspace = NULL; |
| 926 | |
| 927 | if (debug_infrun || info_verbose) |
| 928 | { |
| 929 | target_terminal_ours_for_output (); |
| 930 | |
| 931 | if (exec) |
| 932 | { |
| 933 | fprintf_filtered (gdb_stdlog, |
| 934 | _("Detaching vfork parent process " |
| 935 | "%d after child exec.\n"), |
| 936 | inf->vfork_parent->pid); |
| 937 | } |
| 938 | else |
| 939 | { |
| 940 | fprintf_filtered (gdb_stdlog, |
| 941 | _("Detaching vfork parent process " |
| 942 | "%d after child exit.\n"), |
| 943 | inf->vfork_parent->pid); |
| 944 | } |
| 945 | } |
| 946 | |
| 947 | target_detach (NULL, 0); |
| 948 | |
| 949 | /* Put it back. */ |
| 950 | inf->pspace = pspace; |
| 951 | inf->aspace = aspace; |
| 952 | |
| 953 | do_cleanups (old_chain); |
| 954 | } |
| 955 | else if (exec) |
| 956 | { |
| 957 | /* We're staying attached to the parent, so, really give the |
| 958 | child a new address space. */ |
| 959 | inf->pspace = add_program_space (maybe_new_address_space ()); |
| 960 | inf->aspace = inf->pspace->aspace; |
| 961 | inf->removable = 1; |
| 962 | set_current_program_space (inf->pspace); |
| 963 | |
| 964 | resume_parent = inf->vfork_parent->pid; |
| 965 | |
| 966 | /* Break the bonds. */ |
| 967 | inf->vfork_parent->vfork_child = NULL; |
| 968 | } |
| 969 | else |
| 970 | { |
| 971 | struct cleanup *old_chain; |
| 972 | struct program_space *pspace; |
| 973 | |
| 974 | /* If this is a vfork child exiting, then the pspace and |
| 975 | aspaces were shared with the parent. Since we're |
| 976 | reporting the process exit, we'll be mourning all that is |
| 977 | found in the address space, and switching to null_ptid, |
| 978 | preparing to start a new inferior. But, since we don't |
| 979 | want to clobber the parent's address/program spaces, we |
| 980 | go ahead and create a new one for this exiting |
| 981 | inferior. */ |
| 982 | |
| 983 | /* Switch to null_ptid, so that clone_program_space doesn't want |
| 984 | to read the selected frame of a dead process. */ |
| 985 | old_chain = save_inferior_ptid (); |
| 986 | inferior_ptid = null_ptid; |
| 987 | |
| 988 | /* This inferior is dead, so avoid giving the breakpoints |
| 989 | module the option to write through to it (cloning a |
| 990 | program space resets breakpoints). */ |
| 991 | inf->aspace = NULL; |
| 992 | inf->pspace = NULL; |
| 993 | pspace = add_program_space (maybe_new_address_space ()); |
| 994 | set_current_program_space (pspace); |
| 995 | inf->removable = 1; |
| 996 | inf->symfile_flags = SYMFILE_NO_READ; |
| 997 | clone_program_space (pspace, inf->vfork_parent->pspace); |
| 998 | inf->pspace = pspace; |
| 999 | inf->aspace = pspace->aspace; |
| 1000 | |
| 1001 | /* Put back inferior_ptid. We'll continue mourning this |
| 1002 | inferior. */ |
| 1003 | do_cleanups (old_chain); |
| 1004 | |
| 1005 | resume_parent = inf->vfork_parent->pid; |
| 1006 | /* Break the bonds. */ |
| 1007 | inf->vfork_parent->vfork_child = NULL; |
| 1008 | } |
| 1009 | |
| 1010 | inf->vfork_parent = NULL; |
| 1011 | |
| 1012 | gdb_assert (current_program_space == inf->pspace); |
| 1013 | |
| 1014 | if (non_stop && resume_parent != -1) |
| 1015 | { |
| 1016 | /* If the user wanted the parent to be running, let it go |
| 1017 | free now. */ |
| 1018 | struct cleanup *old_chain = make_cleanup_restore_current_thread (); |
| 1019 | |
| 1020 | if (debug_infrun) |
| 1021 | fprintf_unfiltered (gdb_stdlog, |
| 1022 | "infrun: resuming vfork parent process %d\n", |
| 1023 | resume_parent); |
| 1024 | |
| 1025 | iterate_over_threads (proceed_after_vfork_done, &resume_parent); |
| 1026 | |
| 1027 | do_cleanups (old_chain); |
| 1028 | } |
| 1029 | } |
| 1030 | } |
| 1031 | |
| 1032 | /* Enum strings for "set|show follow-exec-mode". */ |
| 1033 | |
| 1034 | static const char follow_exec_mode_new[] = "new"; |
| 1035 | static const char follow_exec_mode_same[] = "same"; |
| 1036 | static const char *const follow_exec_mode_names[] = |
| 1037 | { |
| 1038 | follow_exec_mode_new, |
| 1039 | follow_exec_mode_same, |
| 1040 | NULL, |
| 1041 | }; |
| 1042 | |
| 1043 | static const char *follow_exec_mode_string = follow_exec_mode_same; |
| 1044 | static void |
| 1045 | show_follow_exec_mode_string (struct ui_file *file, int from_tty, |
| 1046 | struct cmd_list_element *c, const char *value) |
| 1047 | { |
| 1048 | fprintf_filtered (file, _("Follow exec mode is \"%s\".\n"), value); |
| 1049 | } |
| 1050 | |
| 1051 | /* EXECD_PATHNAME is assumed to be non-NULL. */ |
| 1052 | |
| 1053 | static void |
| 1054 | follow_exec (ptid_t ptid, char *execd_pathname) |
| 1055 | { |
| 1056 | struct thread_info *th, *tmp; |
| 1057 | struct inferior *inf = current_inferior (); |
| 1058 | int pid = ptid_get_pid (ptid); |
| 1059 | |
| 1060 | /* This is an exec event that we actually wish to pay attention to. |
| 1061 | Refresh our symbol table to the newly exec'd program, remove any |
| 1062 | momentary bp's, etc. |
| 1063 | |
| 1064 | If there are breakpoints, they aren't really inserted now, |
| 1065 | since the exec() transformed our inferior into a fresh set |
| 1066 | of instructions. |
| 1067 | |
| 1068 | We want to preserve symbolic breakpoints on the list, since |
| 1069 | we have hopes that they can be reset after the new a.out's |
| 1070 | symbol table is read. |
| 1071 | |
| 1072 | However, any "raw" breakpoints must be removed from the list |
| 1073 | (e.g., the solib bp's), since their address is probably invalid |
| 1074 | now. |
| 1075 | |
| 1076 | And, we DON'T want to call delete_breakpoints() here, since |
| 1077 | that may write the bp's "shadow contents" (the instruction |
| 1078 | value that was overwritten witha TRAP instruction). Since |
| 1079 | we now have a new a.out, those shadow contents aren't valid. */ |
| 1080 | |
| 1081 | mark_breakpoints_out (); |
| 1082 | |
| 1083 | /* The target reports the exec event to the main thread, even if |
| 1084 | some other thread does the exec, and even if the main thread was |
| 1085 | stopped or already gone. We may still have non-leader threads of |
| 1086 | the process on our list. E.g., on targets that don't have thread |
| 1087 | exit events (like remote); or on native Linux in non-stop mode if |
| 1088 | there were only two threads in the inferior and the non-leader |
| 1089 | one is the one that execs (and nothing forces an update of the |
| 1090 | thread list up to here). When debugging remotely, it's best to |
| 1091 | avoid extra traffic, when possible, so avoid syncing the thread |
| 1092 | list with the target, and instead go ahead and delete all threads |
| 1093 | of the process but one that reported the event. Note this must |
| 1094 | be done before calling update_breakpoints_after_exec, as |
| 1095 | otherwise clearing the threads' resources would reference stale |
| 1096 | thread breakpoints -- it may have been one of these threads that |
| 1097 | stepped across the exec. We could just clear their stepping |
| 1098 | states, but as long as we're iterating, might as well delete |
| 1099 | them. Deleting them now rather than at the next user-visible |
| 1100 | stop provides a nicer sequence of events for user and MI |
| 1101 | notifications. */ |
| 1102 | ALL_THREADS_SAFE (th, tmp) |
| 1103 | if (ptid_get_pid (th->ptid) == pid && !ptid_equal (th->ptid, ptid)) |
| 1104 | delete_thread (th->ptid); |
| 1105 | |
| 1106 | /* We also need to clear any left over stale state for the |
| 1107 | leader/event thread. E.g., if there was any step-resume |
| 1108 | breakpoint or similar, it's gone now. We cannot truly |
| 1109 | step-to-next statement through an exec(). */ |
| 1110 | th = inferior_thread (); |
| 1111 | th->control.step_resume_breakpoint = NULL; |
| 1112 | th->control.exception_resume_breakpoint = NULL; |
| 1113 | th->control.single_step_breakpoints = NULL; |
| 1114 | th->control.step_range_start = 0; |
| 1115 | th->control.step_range_end = 0; |
| 1116 | |
| 1117 | /* The user may have had the main thread held stopped in the |
| 1118 | previous image (e.g., schedlock on, or non-stop). Release |
| 1119 | it now. */ |
| 1120 | th->stop_requested = 0; |
| 1121 | |
| 1122 | update_breakpoints_after_exec (); |
| 1123 | |
| 1124 | /* What is this a.out's name? */ |
| 1125 | printf_unfiltered (_("%s is executing new program: %s\n"), |
| 1126 | target_pid_to_str (inferior_ptid), |
| 1127 | execd_pathname); |
| 1128 | |
| 1129 | /* We've followed the inferior through an exec. Therefore, the |
| 1130 | inferior has essentially been killed & reborn. */ |
| 1131 | |
| 1132 | gdb_flush (gdb_stdout); |
| 1133 | |
| 1134 | breakpoint_init_inferior (inf_execd); |
| 1135 | |
| 1136 | if (*gdb_sysroot != '\0') |
| 1137 | { |
| 1138 | char *name = exec_file_find (execd_pathname, NULL); |
| 1139 | |
| 1140 | execd_pathname = alloca (strlen (name) + 1); |
| 1141 | strcpy (execd_pathname, name); |
| 1142 | xfree (name); |
| 1143 | } |
| 1144 | |
| 1145 | /* Reset the shared library package. This ensures that we get a |
| 1146 | shlib event when the child reaches "_start", at which point the |
| 1147 | dld will have had a chance to initialize the child. */ |
| 1148 | /* Also, loading a symbol file below may trigger symbol lookups, and |
| 1149 | we don't want those to be satisfied by the libraries of the |
| 1150 | previous incarnation of this process. */ |
| 1151 | no_shared_libraries (NULL, 0); |
| 1152 | |
| 1153 | if (follow_exec_mode_string == follow_exec_mode_new) |
| 1154 | { |
| 1155 | struct program_space *pspace; |
| 1156 | |
| 1157 | /* The user wants to keep the old inferior and program spaces |
| 1158 | around. Create a new fresh one, and switch to it. */ |
| 1159 | |
| 1160 | inf = add_inferior (current_inferior ()->pid); |
| 1161 | pspace = add_program_space (maybe_new_address_space ()); |
| 1162 | inf->pspace = pspace; |
| 1163 | inf->aspace = pspace->aspace; |
| 1164 | |
| 1165 | exit_inferior_num_silent (current_inferior ()->num); |
| 1166 | |
| 1167 | set_current_inferior (inf); |
| 1168 | set_current_program_space (pspace); |
| 1169 | } |
| 1170 | else |
| 1171 | { |
| 1172 | /* The old description may no longer be fit for the new image. |
| 1173 | E.g, a 64-bit process exec'ed a 32-bit process. Clear the |
| 1174 | old description; we'll read a new one below. No need to do |
| 1175 | this on "follow-exec-mode new", as the old inferior stays |
| 1176 | around (its description is later cleared/refetched on |
| 1177 | restart). */ |
| 1178 | target_clear_description (); |
| 1179 | } |
| 1180 | |
| 1181 | gdb_assert (current_program_space == inf->pspace); |
| 1182 | |
| 1183 | /* That a.out is now the one to use. */ |
| 1184 | exec_file_attach (execd_pathname, 0); |
| 1185 | |
| 1186 | /* SYMFILE_DEFER_BP_RESET is used as the proper displacement for PIE |
| 1187 | (Position Independent Executable) main symbol file will get applied by |
| 1188 | solib_create_inferior_hook below. breakpoint_re_set would fail to insert |
| 1189 | the breakpoints with the zero displacement. */ |
| 1190 | |
| 1191 | symbol_file_add (execd_pathname, |
| 1192 | (inf->symfile_flags |
| 1193 | | SYMFILE_MAINLINE | SYMFILE_DEFER_BP_RESET), |
| 1194 | NULL, 0); |
| 1195 | |
| 1196 | if ((inf->symfile_flags & SYMFILE_NO_READ) == 0) |
| 1197 | set_initial_language (); |
| 1198 | |
| 1199 | /* If the target can specify a description, read it. Must do this |
| 1200 | after flipping to the new executable (because the target supplied |
| 1201 | description must be compatible with the executable's |
| 1202 | architecture, and the old executable may e.g., be 32-bit, while |
| 1203 | the new one 64-bit), and before anything involving memory or |
| 1204 | registers. */ |
| 1205 | target_find_description (); |
| 1206 | |
| 1207 | solib_create_inferior_hook (0); |
| 1208 | |
| 1209 | jit_inferior_created_hook (); |
| 1210 | |
| 1211 | breakpoint_re_set (); |
| 1212 | |
| 1213 | /* Reinsert all breakpoints. (Those which were symbolic have |
| 1214 | been reset to the proper address in the new a.out, thanks |
| 1215 | to symbol_file_command...). */ |
| 1216 | insert_breakpoints (); |
| 1217 | |
| 1218 | /* The next resume of this inferior should bring it to the shlib |
| 1219 | startup breakpoints. (If the user had also set bp's on |
| 1220 | "main" from the old (parent) process, then they'll auto- |
| 1221 | matically get reset there in the new process.). */ |
| 1222 | } |
| 1223 | |
| 1224 | /* Info about an instruction that is being stepped over. */ |
| 1225 | |
| 1226 | struct step_over_info |
| 1227 | { |
| 1228 | /* If we're stepping past a breakpoint, this is the address space |
| 1229 | and address of the instruction the breakpoint is set at. We'll |
| 1230 | skip inserting all breakpoints here. Valid iff ASPACE is |
| 1231 | non-NULL. */ |
| 1232 | struct address_space *aspace; |
| 1233 | CORE_ADDR address; |
| 1234 | |
| 1235 | /* The instruction being stepped over triggers a nonsteppable |
| 1236 | watchpoint. If true, we'll skip inserting watchpoints. */ |
| 1237 | int nonsteppable_watchpoint_p; |
| 1238 | }; |
| 1239 | |
| 1240 | /* The step-over info of the location that is being stepped over. |
| 1241 | |
| 1242 | Note that with async/breakpoint always-inserted mode, a user might |
| 1243 | set a new breakpoint/watchpoint/etc. exactly while a breakpoint is |
| 1244 | being stepped over. As setting a new breakpoint inserts all |
| 1245 | breakpoints, we need to make sure the breakpoint being stepped over |
| 1246 | isn't inserted then. We do that by only clearing the step-over |
| 1247 | info when the step-over is actually finished (or aborted). |
| 1248 | |
| 1249 | Presently GDB can only step over one breakpoint at any given time. |
| 1250 | Given threads that can't run code in the same address space as the |
| 1251 | breakpoint's can't really miss the breakpoint, GDB could be taught |
| 1252 | to step-over at most one breakpoint per address space (so this info |
| 1253 | could move to the address space object if/when GDB is extended). |
| 1254 | The set of breakpoints being stepped over will normally be much |
| 1255 | smaller than the set of all breakpoints, so a flag in the |
| 1256 | breakpoint location structure would be wasteful. A separate list |
| 1257 | also saves complexity and run-time, as otherwise we'd have to go |
| 1258 | through all breakpoint locations clearing their flag whenever we |
| 1259 | start a new sequence. Similar considerations weigh against storing |
| 1260 | this info in the thread object. Plus, not all step overs actually |
| 1261 | have breakpoint locations -- e.g., stepping past a single-step |
| 1262 | breakpoint, or stepping to complete a non-continuable |
| 1263 | watchpoint. */ |
| 1264 | static struct step_over_info step_over_info; |
| 1265 | |
| 1266 | /* Record the address of the breakpoint/instruction we're currently |
| 1267 | stepping over. */ |
| 1268 | |
| 1269 | static void |
| 1270 | set_step_over_info (struct address_space *aspace, CORE_ADDR address, |
| 1271 | int nonsteppable_watchpoint_p) |
| 1272 | { |
| 1273 | step_over_info.aspace = aspace; |
| 1274 | step_over_info.address = address; |
| 1275 | step_over_info.nonsteppable_watchpoint_p = nonsteppable_watchpoint_p; |
| 1276 | } |
| 1277 | |
| 1278 | /* Called when we're not longer stepping over a breakpoint / an |
| 1279 | instruction, so all breakpoints are free to be (re)inserted. */ |
| 1280 | |
| 1281 | static void |
| 1282 | clear_step_over_info (void) |
| 1283 | { |
| 1284 | step_over_info.aspace = NULL; |
| 1285 | step_over_info.address = 0; |
| 1286 | step_over_info.nonsteppable_watchpoint_p = 0; |
| 1287 | } |
| 1288 | |
| 1289 | /* See infrun.h. */ |
| 1290 | |
| 1291 | int |
| 1292 | stepping_past_instruction_at (struct address_space *aspace, |
| 1293 | CORE_ADDR address) |
| 1294 | { |
| 1295 | return (step_over_info.aspace != NULL |
| 1296 | && breakpoint_address_match (aspace, address, |
| 1297 | step_over_info.aspace, |
| 1298 | step_over_info.address)); |
| 1299 | } |
| 1300 | |
| 1301 | /* See infrun.h. */ |
| 1302 | |
| 1303 | int |
| 1304 | stepping_past_nonsteppable_watchpoint (void) |
| 1305 | { |
| 1306 | return step_over_info.nonsteppable_watchpoint_p; |
| 1307 | } |
| 1308 | |
| 1309 | /* Returns true if step-over info is valid. */ |
| 1310 | |
| 1311 | static int |
| 1312 | step_over_info_valid_p (void) |
| 1313 | { |
| 1314 | return (step_over_info.aspace != NULL |
| 1315 | || stepping_past_nonsteppable_watchpoint ()); |
| 1316 | } |
| 1317 | |
| 1318 | \f |
| 1319 | /* Displaced stepping. */ |
| 1320 | |
| 1321 | /* In non-stop debugging mode, we must take special care to manage |
| 1322 | breakpoints properly; in particular, the traditional strategy for |
| 1323 | stepping a thread past a breakpoint it has hit is unsuitable. |
| 1324 | 'Displaced stepping' is a tactic for stepping one thread past a |
| 1325 | breakpoint it has hit while ensuring that other threads running |
| 1326 | concurrently will hit the breakpoint as they should. |
| 1327 | |
| 1328 | The traditional way to step a thread T off a breakpoint in a |
| 1329 | multi-threaded program in all-stop mode is as follows: |
| 1330 | |
| 1331 | a0) Initially, all threads are stopped, and breakpoints are not |
| 1332 | inserted. |
| 1333 | a1) We single-step T, leaving breakpoints uninserted. |
| 1334 | a2) We insert breakpoints, and resume all threads. |
| 1335 | |
| 1336 | In non-stop debugging, however, this strategy is unsuitable: we |
| 1337 | don't want to have to stop all threads in the system in order to |
| 1338 | continue or step T past a breakpoint. Instead, we use displaced |
| 1339 | stepping: |
| 1340 | |
| 1341 | n0) Initially, T is stopped, other threads are running, and |
| 1342 | breakpoints are inserted. |
| 1343 | n1) We copy the instruction "under" the breakpoint to a separate |
| 1344 | location, outside the main code stream, making any adjustments |
| 1345 | to the instruction, register, and memory state as directed by |
| 1346 | T's architecture. |
| 1347 | n2) We single-step T over the instruction at its new location. |
| 1348 | n3) We adjust the resulting register and memory state as directed |
| 1349 | by T's architecture. This includes resetting T's PC to point |
| 1350 | back into the main instruction stream. |
| 1351 | n4) We resume T. |
| 1352 | |
| 1353 | This approach depends on the following gdbarch methods: |
| 1354 | |
| 1355 | - gdbarch_max_insn_length and gdbarch_displaced_step_location |
| 1356 | indicate where to copy the instruction, and how much space must |
| 1357 | be reserved there. We use these in step n1. |
| 1358 | |
| 1359 | - gdbarch_displaced_step_copy_insn copies a instruction to a new |
| 1360 | address, and makes any necessary adjustments to the instruction, |
| 1361 | register contents, and memory. We use this in step n1. |
| 1362 | |
| 1363 | - gdbarch_displaced_step_fixup adjusts registers and memory after |
| 1364 | we have successfuly single-stepped the instruction, to yield the |
| 1365 | same effect the instruction would have had if we had executed it |
| 1366 | at its original address. We use this in step n3. |
| 1367 | |
| 1368 | - gdbarch_displaced_step_free_closure provides cleanup. |
| 1369 | |
| 1370 | The gdbarch_displaced_step_copy_insn and |
| 1371 | gdbarch_displaced_step_fixup functions must be written so that |
| 1372 | copying an instruction with gdbarch_displaced_step_copy_insn, |
| 1373 | single-stepping across the copied instruction, and then applying |
| 1374 | gdbarch_displaced_insn_fixup should have the same effects on the |
| 1375 | thread's memory and registers as stepping the instruction in place |
| 1376 | would have. Exactly which responsibilities fall to the copy and |
| 1377 | which fall to the fixup is up to the author of those functions. |
| 1378 | |
| 1379 | See the comments in gdbarch.sh for details. |
| 1380 | |
| 1381 | Note that displaced stepping and software single-step cannot |
| 1382 | currently be used in combination, although with some care I think |
| 1383 | they could be made to. Software single-step works by placing |
| 1384 | breakpoints on all possible subsequent instructions; if the |
| 1385 | displaced instruction is a PC-relative jump, those breakpoints |
| 1386 | could fall in very strange places --- on pages that aren't |
| 1387 | executable, or at addresses that are not proper instruction |
| 1388 | boundaries. (We do generally let other threads run while we wait |
| 1389 | to hit the software single-step breakpoint, and they might |
| 1390 | encounter such a corrupted instruction.) One way to work around |
| 1391 | this would be to have gdbarch_displaced_step_copy_insn fully |
| 1392 | simulate the effect of PC-relative instructions (and return NULL) |
| 1393 | on architectures that use software single-stepping. |
| 1394 | |
| 1395 | In non-stop mode, we can have independent and simultaneous step |
| 1396 | requests, so more than one thread may need to simultaneously step |
| 1397 | over a breakpoint. The current implementation assumes there is |
| 1398 | only one scratch space per process. In this case, we have to |
| 1399 | serialize access to the scratch space. If thread A wants to step |
| 1400 | over a breakpoint, but we are currently waiting for some other |
| 1401 | thread to complete a displaced step, we leave thread A stopped and |
| 1402 | place it in the displaced_step_request_queue. Whenever a displaced |
| 1403 | step finishes, we pick the next thread in the queue and start a new |
| 1404 | displaced step operation on it. See displaced_step_prepare and |
| 1405 | displaced_step_fixup for details. */ |
| 1406 | |
| 1407 | struct displaced_step_request |
| 1408 | { |
| 1409 | ptid_t ptid; |
| 1410 | struct displaced_step_request *next; |
| 1411 | }; |
| 1412 | |
| 1413 | /* Per-inferior displaced stepping state. */ |
| 1414 | struct displaced_step_inferior_state |
| 1415 | { |
| 1416 | /* Pointer to next in linked list. */ |
| 1417 | struct displaced_step_inferior_state *next; |
| 1418 | |
| 1419 | /* The process this displaced step state refers to. */ |
| 1420 | int pid; |
| 1421 | |
| 1422 | /* A queue of pending displaced stepping requests. One entry per |
| 1423 | thread that needs to do a displaced step. */ |
| 1424 | struct displaced_step_request *step_request_queue; |
| 1425 | |
| 1426 | /* If this is not null_ptid, this is the thread carrying out a |
| 1427 | displaced single-step in process PID. This thread's state will |
| 1428 | require fixing up once it has completed its step. */ |
| 1429 | ptid_t step_ptid; |
| 1430 | |
| 1431 | /* The architecture the thread had when we stepped it. */ |
| 1432 | struct gdbarch *step_gdbarch; |
| 1433 | |
| 1434 | /* The closure provided gdbarch_displaced_step_copy_insn, to be used |
| 1435 | for post-step cleanup. */ |
| 1436 | struct displaced_step_closure *step_closure; |
| 1437 | |
| 1438 | /* The address of the original instruction, and the copy we |
| 1439 | made. */ |
| 1440 | CORE_ADDR step_original, step_copy; |
| 1441 | |
| 1442 | /* Saved contents of copy area. */ |
| 1443 | gdb_byte *step_saved_copy; |
| 1444 | }; |
| 1445 | |
| 1446 | /* The list of states of processes involved in displaced stepping |
| 1447 | presently. */ |
| 1448 | static struct displaced_step_inferior_state *displaced_step_inferior_states; |
| 1449 | |
| 1450 | /* Get the displaced stepping state of process PID. */ |
| 1451 | |
| 1452 | static struct displaced_step_inferior_state * |
| 1453 | get_displaced_stepping_state (int pid) |
| 1454 | { |
| 1455 | struct displaced_step_inferior_state *state; |
| 1456 | |
| 1457 | for (state = displaced_step_inferior_states; |
| 1458 | state != NULL; |
| 1459 | state = state->next) |
| 1460 | if (state->pid == pid) |
| 1461 | return state; |
| 1462 | |
| 1463 | return NULL; |
| 1464 | } |
| 1465 | |
| 1466 | /* Return true if process PID has a thread doing a displaced step. */ |
| 1467 | |
| 1468 | static int |
| 1469 | displaced_step_in_progress (int pid) |
| 1470 | { |
| 1471 | struct displaced_step_inferior_state *displaced; |
| 1472 | |
| 1473 | displaced = get_displaced_stepping_state (pid); |
| 1474 | if (displaced != NULL && !ptid_equal (displaced->step_ptid, null_ptid)) |
| 1475 | return 1; |
| 1476 | |
| 1477 | return 0; |
| 1478 | } |
| 1479 | |
| 1480 | /* Add a new displaced stepping state for process PID to the displaced |
| 1481 | stepping state list, or return a pointer to an already existing |
| 1482 | entry, if it already exists. Never returns NULL. */ |
| 1483 | |
| 1484 | static struct displaced_step_inferior_state * |
| 1485 | add_displaced_stepping_state (int pid) |
| 1486 | { |
| 1487 | struct displaced_step_inferior_state *state; |
| 1488 | |
| 1489 | for (state = displaced_step_inferior_states; |
| 1490 | state != NULL; |
| 1491 | state = state->next) |
| 1492 | if (state->pid == pid) |
| 1493 | return state; |
| 1494 | |
| 1495 | state = xcalloc (1, sizeof (*state)); |
| 1496 | state->pid = pid; |
| 1497 | state->next = displaced_step_inferior_states; |
| 1498 | displaced_step_inferior_states = state; |
| 1499 | |
| 1500 | return state; |
| 1501 | } |
| 1502 | |
| 1503 | /* If inferior is in displaced stepping, and ADDR equals to starting address |
| 1504 | of copy area, return corresponding displaced_step_closure. Otherwise, |
| 1505 | return NULL. */ |
| 1506 | |
| 1507 | struct displaced_step_closure* |
| 1508 | get_displaced_step_closure_by_addr (CORE_ADDR addr) |
| 1509 | { |
| 1510 | struct displaced_step_inferior_state *displaced |
| 1511 | = get_displaced_stepping_state (ptid_get_pid (inferior_ptid)); |
| 1512 | |
| 1513 | /* If checking the mode of displaced instruction in copy area. */ |
| 1514 | if (displaced && !ptid_equal (displaced->step_ptid, null_ptid) |
| 1515 | && (displaced->step_copy == addr)) |
| 1516 | return displaced->step_closure; |
| 1517 | |
| 1518 | return NULL; |
| 1519 | } |
| 1520 | |
| 1521 | /* Remove the displaced stepping state of process PID. */ |
| 1522 | |
| 1523 | static void |
| 1524 | remove_displaced_stepping_state (int pid) |
| 1525 | { |
| 1526 | struct displaced_step_inferior_state *it, **prev_next_p; |
| 1527 | |
| 1528 | gdb_assert (pid != 0); |
| 1529 | |
| 1530 | it = displaced_step_inferior_states; |
| 1531 | prev_next_p = &displaced_step_inferior_states; |
| 1532 | while (it) |
| 1533 | { |
| 1534 | if (it->pid == pid) |
| 1535 | { |
| 1536 | *prev_next_p = it->next; |
| 1537 | xfree (it); |
| 1538 | return; |
| 1539 | } |
| 1540 | |
| 1541 | prev_next_p = &it->next; |
| 1542 | it = *prev_next_p; |
| 1543 | } |
| 1544 | } |
| 1545 | |
| 1546 | static void |
| 1547 | infrun_inferior_exit (struct inferior *inf) |
| 1548 | { |
| 1549 | remove_displaced_stepping_state (inf->pid); |
| 1550 | } |
| 1551 | |
| 1552 | /* If ON, and the architecture supports it, GDB will use displaced |
| 1553 | stepping to step over breakpoints. If OFF, or if the architecture |
| 1554 | doesn't support it, GDB will instead use the traditional |
| 1555 | hold-and-step approach. If AUTO (which is the default), GDB will |
| 1556 | decide which technique to use to step over breakpoints depending on |
| 1557 | which of all-stop or non-stop mode is active --- displaced stepping |
| 1558 | in non-stop mode; hold-and-step in all-stop mode. */ |
| 1559 | |
| 1560 | static enum auto_boolean can_use_displaced_stepping = AUTO_BOOLEAN_AUTO; |
| 1561 | |
| 1562 | static void |
| 1563 | show_can_use_displaced_stepping (struct ui_file *file, int from_tty, |
| 1564 | struct cmd_list_element *c, |
| 1565 | const char *value) |
| 1566 | { |
| 1567 | if (can_use_displaced_stepping == AUTO_BOOLEAN_AUTO) |
| 1568 | fprintf_filtered (file, |
| 1569 | _("Debugger's willingness to use displaced stepping " |
| 1570 | "to step over breakpoints is %s (currently %s).\n"), |
| 1571 | value, non_stop ? "on" : "off"); |
| 1572 | else |
| 1573 | fprintf_filtered (file, |
| 1574 | _("Debugger's willingness to use displaced stepping " |
| 1575 | "to step over breakpoints is %s.\n"), value); |
| 1576 | } |
| 1577 | |
| 1578 | /* Return non-zero if displaced stepping can/should be used to step |
| 1579 | over breakpoints. */ |
| 1580 | |
| 1581 | static int |
| 1582 | use_displaced_stepping (struct gdbarch *gdbarch) |
| 1583 | { |
| 1584 | return (((can_use_displaced_stepping == AUTO_BOOLEAN_AUTO && non_stop) |
| 1585 | || can_use_displaced_stepping == AUTO_BOOLEAN_TRUE) |
| 1586 | && gdbarch_displaced_step_copy_insn_p (gdbarch) |
| 1587 | && find_record_target () == NULL); |
| 1588 | } |
| 1589 | |
| 1590 | /* Clean out any stray displaced stepping state. */ |
| 1591 | static void |
| 1592 | displaced_step_clear (struct displaced_step_inferior_state *displaced) |
| 1593 | { |
| 1594 | /* Indicate that there is no cleanup pending. */ |
| 1595 | displaced->step_ptid = null_ptid; |
| 1596 | |
| 1597 | if (displaced->step_closure) |
| 1598 | { |
| 1599 | gdbarch_displaced_step_free_closure (displaced->step_gdbarch, |
| 1600 | displaced->step_closure); |
| 1601 | displaced->step_closure = NULL; |
| 1602 | } |
| 1603 | } |
| 1604 | |
| 1605 | static void |
| 1606 | displaced_step_clear_cleanup (void *arg) |
| 1607 | { |
| 1608 | struct displaced_step_inferior_state *state = arg; |
| 1609 | |
| 1610 | displaced_step_clear (state); |
| 1611 | } |
| 1612 | |
| 1613 | /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */ |
| 1614 | void |
| 1615 | displaced_step_dump_bytes (struct ui_file *file, |
| 1616 | const gdb_byte *buf, |
| 1617 | size_t len) |
| 1618 | { |
| 1619 | int i; |
| 1620 | |
| 1621 | for (i = 0; i < len; i++) |
| 1622 | fprintf_unfiltered (file, "%02x ", buf[i]); |
| 1623 | fputs_unfiltered ("\n", file); |
| 1624 | } |
| 1625 | |
| 1626 | /* Prepare to single-step, using displaced stepping. |
| 1627 | |
| 1628 | Note that we cannot use displaced stepping when we have a signal to |
| 1629 | deliver. If we have a signal to deliver and an instruction to step |
| 1630 | over, then after the step, there will be no indication from the |
| 1631 | target whether the thread entered a signal handler or ignored the |
| 1632 | signal and stepped over the instruction successfully --- both cases |
| 1633 | result in a simple SIGTRAP. In the first case we mustn't do a |
| 1634 | fixup, and in the second case we must --- but we can't tell which. |
| 1635 | Comments in the code for 'random signals' in handle_inferior_event |
| 1636 | explain how we handle this case instead. |
| 1637 | |
| 1638 | Returns 1 if preparing was successful -- this thread is going to be |
| 1639 | stepped now; or 0 if displaced stepping this thread got queued. */ |
| 1640 | static int |
| 1641 | displaced_step_prepare (ptid_t ptid) |
| 1642 | { |
| 1643 | struct cleanup *old_cleanups, *ignore_cleanups; |
| 1644 | struct thread_info *tp = find_thread_ptid (ptid); |
| 1645 | struct regcache *regcache = get_thread_regcache (ptid); |
| 1646 | struct gdbarch *gdbarch = get_regcache_arch (regcache); |
| 1647 | CORE_ADDR original, copy; |
| 1648 | ULONGEST len; |
| 1649 | struct displaced_step_closure *closure; |
| 1650 | struct displaced_step_inferior_state *displaced; |
| 1651 | int status; |
| 1652 | |
| 1653 | /* We should never reach this function if the architecture does not |
| 1654 | support displaced stepping. */ |
| 1655 | gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch)); |
| 1656 | |
| 1657 | /* Disable range stepping while executing in the scratch pad. We |
| 1658 | want a single-step even if executing the displaced instruction in |
| 1659 | the scratch buffer lands within the stepping range (e.g., a |
| 1660 | jump/branch). */ |
| 1661 | tp->control.may_range_step = 0; |
| 1662 | |
| 1663 | /* We have to displaced step one thread at a time, as we only have |
| 1664 | access to a single scratch space per inferior. */ |
| 1665 | |
| 1666 | displaced = add_displaced_stepping_state (ptid_get_pid (ptid)); |
| 1667 | |
| 1668 | if (!ptid_equal (displaced->step_ptid, null_ptid)) |
| 1669 | { |
| 1670 | /* Already waiting for a displaced step to finish. Defer this |
| 1671 | request and place in queue. */ |
| 1672 | struct displaced_step_request *req, *new_req; |
| 1673 | |
| 1674 | if (debug_displaced) |
| 1675 | fprintf_unfiltered (gdb_stdlog, |
| 1676 | "displaced: defering step of %s\n", |
| 1677 | target_pid_to_str (ptid)); |
| 1678 | |
| 1679 | new_req = xmalloc (sizeof (*new_req)); |
| 1680 | new_req->ptid = ptid; |
| 1681 | new_req->next = NULL; |
| 1682 | |
| 1683 | if (displaced->step_request_queue) |
| 1684 | { |
| 1685 | for (req = displaced->step_request_queue; |
| 1686 | req && req->next; |
| 1687 | req = req->next) |
| 1688 | ; |
| 1689 | req->next = new_req; |
| 1690 | } |
| 1691 | else |
| 1692 | displaced->step_request_queue = new_req; |
| 1693 | |
| 1694 | return 0; |
| 1695 | } |
| 1696 | else |
| 1697 | { |
| 1698 | if (debug_displaced) |
| 1699 | fprintf_unfiltered (gdb_stdlog, |
| 1700 | "displaced: stepping %s now\n", |
| 1701 | target_pid_to_str (ptid)); |
| 1702 | } |
| 1703 | |
| 1704 | displaced_step_clear (displaced); |
| 1705 | |
| 1706 | old_cleanups = save_inferior_ptid (); |
| 1707 | inferior_ptid = ptid; |
| 1708 | |
| 1709 | original = regcache_read_pc (regcache); |
| 1710 | |
| 1711 | copy = gdbarch_displaced_step_location (gdbarch); |
| 1712 | len = gdbarch_max_insn_length (gdbarch); |
| 1713 | |
| 1714 | /* Save the original contents of the copy area. */ |
| 1715 | displaced->step_saved_copy = xmalloc (len); |
| 1716 | ignore_cleanups = make_cleanup (free_current_contents, |
| 1717 | &displaced->step_saved_copy); |
| 1718 | status = target_read_memory (copy, displaced->step_saved_copy, len); |
| 1719 | if (status != 0) |
| 1720 | throw_error (MEMORY_ERROR, |
| 1721 | _("Error accessing memory address %s (%s) for " |
| 1722 | "displaced-stepping scratch space."), |
| 1723 | paddress (gdbarch, copy), safe_strerror (status)); |
| 1724 | if (debug_displaced) |
| 1725 | { |
| 1726 | fprintf_unfiltered (gdb_stdlog, "displaced: saved %s: ", |
| 1727 | paddress (gdbarch, copy)); |
| 1728 | displaced_step_dump_bytes (gdb_stdlog, |
| 1729 | displaced->step_saved_copy, |
| 1730 | len); |
| 1731 | }; |
| 1732 | |
| 1733 | closure = gdbarch_displaced_step_copy_insn (gdbarch, |
| 1734 | original, copy, regcache); |
| 1735 | |
| 1736 | /* We don't support the fully-simulated case at present. */ |
| 1737 | gdb_assert (closure); |
| 1738 | |
| 1739 | /* Save the information we need to fix things up if the step |
| 1740 | succeeds. */ |
| 1741 | displaced->step_ptid = ptid; |
| 1742 | displaced->step_gdbarch = gdbarch; |
| 1743 | displaced->step_closure = closure; |
| 1744 | displaced->step_original = original; |
| 1745 | displaced->step_copy = copy; |
| 1746 | |
| 1747 | make_cleanup (displaced_step_clear_cleanup, displaced); |
| 1748 | |
| 1749 | /* Resume execution at the copy. */ |
| 1750 | regcache_write_pc (regcache, copy); |
| 1751 | |
| 1752 | discard_cleanups (ignore_cleanups); |
| 1753 | |
| 1754 | do_cleanups (old_cleanups); |
| 1755 | |
| 1756 | if (debug_displaced) |
| 1757 | fprintf_unfiltered (gdb_stdlog, "displaced: displaced pc to %s\n", |
| 1758 | paddress (gdbarch, copy)); |
| 1759 | |
| 1760 | return 1; |
| 1761 | } |
| 1762 | |
| 1763 | static void |
| 1764 | write_memory_ptid (ptid_t ptid, CORE_ADDR memaddr, |
| 1765 | const gdb_byte *myaddr, int len) |
| 1766 | { |
| 1767 | struct cleanup *ptid_cleanup = save_inferior_ptid (); |
| 1768 | |
| 1769 | inferior_ptid = ptid; |
| 1770 | write_memory (memaddr, myaddr, len); |
| 1771 | do_cleanups (ptid_cleanup); |
| 1772 | } |
| 1773 | |
| 1774 | /* Restore the contents of the copy area for thread PTID. */ |
| 1775 | |
| 1776 | static void |
| 1777 | displaced_step_restore (struct displaced_step_inferior_state *displaced, |
| 1778 | ptid_t ptid) |
| 1779 | { |
| 1780 | ULONGEST len = gdbarch_max_insn_length (displaced->step_gdbarch); |
| 1781 | |
| 1782 | write_memory_ptid (ptid, displaced->step_copy, |
| 1783 | displaced->step_saved_copy, len); |
| 1784 | if (debug_displaced) |
| 1785 | fprintf_unfiltered (gdb_stdlog, "displaced: restored %s %s\n", |
| 1786 | target_pid_to_str (ptid), |
| 1787 | paddress (displaced->step_gdbarch, |
| 1788 | displaced->step_copy)); |
| 1789 | } |
| 1790 | |
| 1791 | static void |
| 1792 | displaced_step_fixup (ptid_t event_ptid, enum gdb_signal signal) |
| 1793 | { |
| 1794 | struct cleanup *old_cleanups; |
| 1795 | struct displaced_step_inferior_state *displaced |
| 1796 | = get_displaced_stepping_state (ptid_get_pid (event_ptid)); |
| 1797 | |
| 1798 | /* Was any thread of this process doing a displaced step? */ |
| 1799 | if (displaced == NULL) |
| 1800 | return; |
| 1801 | |
| 1802 | /* Was this event for the pid we displaced? */ |
| 1803 | if (ptid_equal (displaced->step_ptid, null_ptid) |
| 1804 | || ! ptid_equal (displaced->step_ptid, event_ptid)) |
| 1805 | return; |
| 1806 | |
| 1807 | old_cleanups = make_cleanup (displaced_step_clear_cleanup, displaced); |
| 1808 | |
| 1809 | displaced_step_restore (displaced, displaced->step_ptid); |
| 1810 | |
| 1811 | /* Fixup may need to read memory/registers. Switch to the thread |
| 1812 | that we're fixing up. Also, target_stopped_by_watchpoint checks |
| 1813 | the current thread. */ |
| 1814 | switch_to_thread (event_ptid); |
| 1815 | |
| 1816 | /* Did the instruction complete successfully? */ |
| 1817 | if (signal == GDB_SIGNAL_TRAP |
| 1818 | && !(target_stopped_by_watchpoint () |
| 1819 | && (gdbarch_have_nonsteppable_watchpoint (displaced->step_gdbarch) |
| 1820 | || target_have_steppable_watchpoint))) |
| 1821 | { |
| 1822 | /* Fix up the resulting state. */ |
| 1823 | gdbarch_displaced_step_fixup (displaced->step_gdbarch, |
| 1824 | displaced->step_closure, |
| 1825 | displaced->step_original, |
| 1826 | displaced->step_copy, |
| 1827 | get_thread_regcache (displaced->step_ptid)); |
| 1828 | } |
| 1829 | else |
| 1830 | { |
| 1831 | /* Since the instruction didn't complete, all we can do is |
| 1832 | relocate the PC. */ |
| 1833 | struct regcache *regcache = get_thread_regcache (event_ptid); |
| 1834 | CORE_ADDR pc = regcache_read_pc (regcache); |
| 1835 | |
| 1836 | pc = displaced->step_original + (pc - displaced->step_copy); |
| 1837 | regcache_write_pc (regcache, pc); |
| 1838 | } |
| 1839 | |
| 1840 | do_cleanups (old_cleanups); |
| 1841 | |
| 1842 | displaced->step_ptid = null_ptid; |
| 1843 | |
| 1844 | /* Are there any pending displaced stepping requests? If so, run |
| 1845 | one now. Leave the state object around, since we're likely to |
| 1846 | need it again soon. */ |
| 1847 | while (displaced->step_request_queue) |
| 1848 | { |
| 1849 | struct displaced_step_request *head; |
| 1850 | ptid_t ptid; |
| 1851 | struct regcache *regcache; |
| 1852 | struct gdbarch *gdbarch; |
| 1853 | CORE_ADDR actual_pc; |
| 1854 | struct address_space *aspace; |
| 1855 | |
| 1856 | head = displaced->step_request_queue; |
| 1857 | ptid = head->ptid; |
| 1858 | displaced->step_request_queue = head->next; |
| 1859 | xfree (head); |
| 1860 | |
| 1861 | context_switch (ptid); |
| 1862 | |
| 1863 | regcache = get_thread_regcache (ptid); |
| 1864 | actual_pc = regcache_read_pc (regcache); |
| 1865 | aspace = get_regcache_aspace (regcache); |
| 1866 | gdbarch = get_regcache_arch (regcache); |
| 1867 | |
| 1868 | if (breakpoint_here_p (aspace, actual_pc)) |
| 1869 | { |
| 1870 | if (debug_displaced) |
| 1871 | fprintf_unfiltered (gdb_stdlog, |
| 1872 | "displaced: stepping queued %s now\n", |
| 1873 | target_pid_to_str (ptid)); |
| 1874 | |
| 1875 | displaced_step_prepare (ptid); |
| 1876 | |
| 1877 | if (debug_displaced) |
| 1878 | { |
| 1879 | CORE_ADDR actual_pc = regcache_read_pc (regcache); |
| 1880 | gdb_byte buf[4]; |
| 1881 | |
| 1882 | fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ", |
| 1883 | paddress (gdbarch, actual_pc)); |
| 1884 | read_memory (actual_pc, buf, sizeof (buf)); |
| 1885 | displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf)); |
| 1886 | } |
| 1887 | |
| 1888 | if (gdbarch_displaced_step_hw_singlestep (gdbarch, |
| 1889 | displaced->step_closure)) |
| 1890 | target_resume (ptid, 1, GDB_SIGNAL_0); |
| 1891 | else |
| 1892 | target_resume (ptid, 0, GDB_SIGNAL_0); |
| 1893 | |
| 1894 | /* Done, we're stepping a thread. */ |
| 1895 | break; |
| 1896 | } |
| 1897 | else |
| 1898 | { |
| 1899 | int step; |
| 1900 | struct thread_info *tp = inferior_thread (); |
| 1901 | |
| 1902 | /* The breakpoint we were sitting under has since been |
| 1903 | removed. */ |
| 1904 | tp->control.trap_expected = 0; |
| 1905 | |
| 1906 | /* Go back to what we were trying to do. */ |
| 1907 | step = currently_stepping (tp); |
| 1908 | |
| 1909 | if (step) |
| 1910 | step = maybe_software_singlestep (gdbarch, actual_pc); |
| 1911 | |
| 1912 | if (debug_displaced) |
| 1913 | fprintf_unfiltered (gdb_stdlog, |
| 1914 | "displaced: breakpoint is gone: %s, step(%d)\n", |
| 1915 | target_pid_to_str (tp->ptid), step); |
| 1916 | |
| 1917 | target_resume (ptid, step, GDB_SIGNAL_0); |
| 1918 | tp->suspend.stop_signal = GDB_SIGNAL_0; |
| 1919 | |
| 1920 | /* This request was discarded. See if there's any other |
| 1921 | thread waiting for its turn. */ |
| 1922 | } |
| 1923 | } |
| 1924 | } |
| 1925 | |
| 1926 | /* Update global variables holding ptids to hold NEW_PTID if they were |
| 1927 | holding OLD_PTID. */ |
| 1928 | static void |
| 1929 | infrun_thread_ptid_changed (ptid_t old_ptid, ptid_t new_ptid) |
| 1930 | { |
| 1931 | struct displaced_step_request *it; |
| 1932 | struct displaced_step_inferior_state *displaced; |
| 1933 | |
| 1934 | if (ptid_equal (inferior_ptid, old_ptid)) |
| 1935 | inferior_ptid = new_ptid; |
| 1936 | |
| 1937 | for (displaced = displaced_step_inferior_states; |
| 1938 | displaced; |
| 1939 | displaced = displaced->next) |
| 1940 | { |
| 1941 | if (ptid_equal (displaced->step_ptid, old_ptid)) |
| 1942 | displaced->step_ptid = new_ptid; |
| 1943 | |
| 1944 | for (it = displaced->step_request_queue; it; it = it->next) |
| 1945 | if (ptid_equal (it->ptid, old_ptid)) |
| 1946 | it->ptid = new_ptid; |
| 1947 | } |
| 1948 | } |
| 1949 | |
| 1950 | \f |
| 1951 | /* Resuming. */ |
| 1952 | |
| 1953 | /* Things to clean up if we QUIT out of resume (). */ |
| 1954 | static void |
| 1955 | resume_cleanups (void *ignore) |
| 1956 | { |
| 1957 | if (!ptid_equal (inferior_ptid, null_ptid)) |
| 1958 | delete_single_step_breakpoints (inferior_thread ()); |
| 1959 | |
| 1960 | normal_stop (); |
| 1961 | } |
| 1962 | |
| 1963 | static const char schedlock_off[] = "off"; |
| 1964 | static const char schedlock_on[] = "on"; |
| 1965 | static const char schedlock_step[] = "step"; |
| 1966 | static const char *const scheduler_enums[] = { |
| 1967 | schedlock_off, |
| 1968 | schedlock_on, |
| 1969 | schedlock_step, |
| 1970 | NULL |
| 1971 | }; |
| 1972 | static const char *scheduler_mode = schedlock_off; |
| 1973 | static void |
| 1974 | show_scheduler_mode (struct ui_file *file, int from_tty, |
| 1975 | struct cmd_list_element *c, const char *value) |
| 1976 | { |
| 1977 | fprintf_filtered (file, |
| 1978 | _("Mode for locking scheduler " |
| 1979 | "during execution is \"%s\".\n"), |
| 1980 | value); |
| 1981 | } |
| 1982 | |
| 1983 | static void |
| 1984 | set_schedlock_func (char *args, int from_tty, struct cmd_list_element *c) |
| 1985 | { |
| 1986 | if (!target_can_lock_scheduler) |
| 1987 | { |
| 1988 | scheduler_mode = schedlock_off; |
| 1989 | error (_("Target '%s' cannot support this command."), target_shortname); |
| 1990 | } |
| 1991 | } |
| 1992 | |
| 1993 | /* True if execution commands resume all threads of all processes by |
| 1994 | default; otherwise, resume only threads of the current inferior |
| 1995 | process. */ |
| 1996 | int sched_multi = 0; |
| 1997 | |
| 1998 | /* Try to setup for software single stepping over the specified location. |
| 1999 | Return 1 if target_resume() should use hardware single step. |
| 2000 | |
| 2001 | GDBARCH the current gdbarch. |
| 2002 | PC the location to step over. */ |
| 2003 | |
| 2004 | static int |
| 2005 | maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc) |
| 2006 | { |
| 2007 | int hw_step = 1; |
| 2008 | |
| 2009 | if (execution_direction == EXEC_FORWARD |
| 2010 | && gdbarch_software_single_step_p (gdbarch) |
| 2011 | && gdbarch_software_single_step (gdbarch, get_current_frame ())) |
| 2012 | { |
| 2013 | hw_step = 0; |
| 2014 | } |
| 2015 | return hw_step; |
| 2016 | } |
| 2017 | |
| 2018 | /* See infrun.h. */ |
| 2019 | |
| 2020 | ptid_t |
| 2021 | user_visible_resume_ptid (int step) |
| 2022 | { |
| 2023 | ptid_t resume_ptid; |
| 2024 | |
| 2025 | if (non_stop) |
| 2026 | { |
| 2027 | /* With non-stop mode on, threads are always handled |
| 2028 | individually. */ |
| 2029 | resume_ptid = inferior_ptid; |
| 2030 | } |
| 2031 | else if ((scheduler_mode == schedlock_on) |
| 2032 | || (scheduler_mode == schedlock_step && step)) |
| 2033 | { |
| 2034 | /* User-settable 'scheduler' mode requires solo thread |
| 2035 | resume. */ |
| 2036 | resume_ptid = inferior_ptid; |
| 2037 | } |
| 2038 | else if (!sched_multi && target_supports_multi_process ()) |
| 2039 | { |
| 2040 | /* Resume all threads of the current process (and none of other |
| 2041 | processes). */ |
| 2042 | resume_ptid = pid_to_ptid (ptid_get_pid (inferior_ptid)); |
| 2043 | } |
| 2044 | else |
| 2045 | { |
| 2046 | /* Resume all threads of all processes. */ |
| 2047 | resume_ptid = RESUME_ALL; |
| 2048 | } |
| 2049 | |
| 2050 | return resume_ptid; |
| 2051 | } |
| 2052 | |
| 2053 | /* Wrapper for target_resume, that handles infrun-specific |
| 2054 | bookkeeping. */ |
| 2055 | |
| 2056 | static void |
| 2057 | do_target_resume (ptid_t resume_ptid, int step, enum gdb_signal sig) |
| 2058 | { |
| 2059 | struct thread_info *tp = inferior_thread (); |
| 2060 | |
| 2061 | /* Install inferior's terminal modes. */ |
| 2062 | target_terminal_inferior (); |
| 2063 | |
| 2064 | /* Avoid confusing the next resume, if the next stop/resume |
| 2065 | happens to apply to another thread. */ |
| 2066 | tp->suspend.stop_signal = GDB_SIGNAL_0; |
| 2067 | |
| 2068 | /* Advise target which signals may be handled silently. |
| 2069 | |
| 2070 | If we have removed breakpoints because we are stepping over one |
| 2071 | in-line (in any thread), we need to receive all signals to avoid |
| 2072 | accidentally skipping a breakpoint during execution of a signal |
| 2073 | handler. |
| 2074 | |
| 2075 | Likewise if we're displaced stepping, otherwise a trap for a |
| 2076 | breakpoint in a signal handler might be confused with the |
| 2077 | displaced step finishing. We don't make the displaced_step_fixup |
| 2078 | step distinguish the cases instead, because: |
| 2079 | |
| 2080 | - a backtrace while stopped in the signal handler would show the |
| 2081 | scratch pad as frame older than the signal handler, instead of |
| 2082 | the real mainline code. |
| 2083 | |
| 2084 | - when the thread is later resumed, the signal handler would |
| 2085 | return to the scratch pad area, which would no longer be |
| 2086 | valid. */ |
| 2087 | if (step_over_info_valid_p () |
| 2088 | || displaced_step_in_progress (ptid_get_pid (tp->ptid))) |
| 2089 | target_pass_signals (0, NULL); |
| 2090 | else |
| 2091 | target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass); |
| 2092 | |
| 2093 | target_resume (resume_ptid, step, sig); |
| 2094 | } |
| 2095 | |
| 2096 | /* Resume the inferior, but allow a QUIT. This is useful if the user |
| 2097 | wants to interrupt some lengthy single-stepping operation |
| 2098 | (for child processes, the SIGINT goes to the inferior, and so |
| 2099 | we get a SIGINT random_signal, but for remote debugging and perhaps |
| 2100 | other targets, that's not true). |
| 2101 | |
| 2102 | SIG is the signal to give the inferior (zero for none). */ |
| 2103 | void |
| 2104 | resume (enum gdb_signal sig) |
| 2105 | { |
| 2106 | struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0); |
| 2107 | struct regcache *regcache = get_current_regcache (); |
| 2108 | struct gdbarch *gdbarch = get_regcache_arch (regcache); |
| 2109 | struct thread_info *tp = inferior_thread (); |
| 2110 | CORE_ADDR pc = regcache_read_pc (regcache); |
| 2111 | struct address_space *aspace = get_regcache_aspace (regcache); |
| 2112 | ptid_t resume_ptid; |
| 2113 | /* This represents the user's step vs continue request. When |
| 2114 | deciding whether "set scheduler-locking step" applies, it's the |
| 2115 | user's intention that counts. */ |
| 2116 | const int user_step = tp->control.stepping_command; |
| 2117 | /* This represents what we'll actually request the target to do. |
| 2118 | This can decay from a step to a continue, if e.g., we need to |
| 2119 | implement single-stepping with breakpoints (software |
| 2120 | single-step). */ |
| 2121 | int step; |
| 2122 | |
| 2123 | tp->stepped_breakpoint = 0; |
| 2124 | |
| 2125 | QUIT; |
| 2126 | |
| 2127 | /* Depends on stepped_breakpoint. */ |
| 2128 | step = currently_stepping (tp); |
| 2129 | |
| 2130 | if (current_inferior ()->waiting_for_vfork_done) |
| 2131 | { |
| 2132 | /* Don't try to single-step a vfork parent that is waiting for |
| 2133 | the child to get out of the shared memory region (by exec'ing |
| 2134 | or exiting). This is particularly important on software |
| 2135 | single-step archs, as the child process would trip on the |
| 2136 | software single step breakpoint inserted for the parent |
| 2137 | process. Since the parent will not actually execute any |
| 2138 | instruction until the child is out of the shared region (such |
| 2139 | are vfork's semantics), it is safe to simply continue it. |
| 2140 | Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for |
| 2141 | the parent, and tell it to `keep_going', which automatically |
| 2142 | re-sets it stepping. */ |
| 2143 | if (debug_infrun) |
| 2144 | fprintf_unfiltered (gdb_stdlog, |
| 2145 | "infrun: resume : clear step\n"); |
| 2146 | step = 0; |
| 2147 | } |
| 2148 | |
| 2149 | if (debug_infrun) |
| 2150 | fprintf_unfiltered (gdb_stdlog, |
| 2151 | "infrun: resume (step=%d, signal=%s), " |
| 2152 | "trap_expected=%d, current thread [%s] at %s\n", |
| 2153 | step, gdb_signal_to_symbol_string (sig), |
| 2154 | tp->control.trap_expected, |
| 2155 | target_pid_to_str (inferior_ptid), |
| 2156 | paddress (gdbarch, pc)); |
| 2157 | |
| 2158 | /* Normally, by the time we reach `resume', the breakpoints are either |
| 2159 | removed or inserted, as appropriate. The exception is if we're sitting |
| 2160 | at a permanent breakpoint; we need to step over it, but permanent |
| 2161 | breakpoints can't be removed. So we have to test for it here. */ |
| 2162 | if (breakpoint_here_p (aspace, pc) == permanent_breakpoint_here) |
| 2163 | { |
| 2164 | if (sig != GDB_SIGNAL_0) |
| 2165 | { |
| 2166 | /* We have a signal to pass to the inferior. The resume |
| 2167 | may, or may not take us to the signal handler. If this |
| 2168 | is a step, we'll need to stop in the signal handler, if |
| 2169 | there's one, (if the target supports stepping into |
| 2170 | handlers), or in the next mainline instruction, if |
| 2171 | there's no handler. If this is a continue, we need to be |
| 2172 | sure to run the handler with all breakpoints inserted. |
| 2173 | In all cases, set a breakpoint at the current address |
| 2174 | (where the handler returns to), and once that breakpoint |
| 2175 | is hit, resume skipping the permanent breakpoint. If |
| 2176 | that breakpoint isn't hit, then we've stepped into the |
| 2177 | signal handler (or hit some other event). We'll delete |
| 2178 | the step-resume breakpoint then. */ |
| 2179 | |
| 2180 | if (debug_infrun) |
| 2181 | fprintf_unfiltered (gdb_stdlog, |
| 2182 | "infrun: resume: skipping permanent breakpoint, " |
| 2183 | "deliver signal first\n"); |
| 2184 | |
| 2185 | clear_step_over_info (); |
| 2186 | tp->control.trap_expected = 0; |
| 2187 | |
| 2188 | if (tp->control.step_resume_breakpoint == NULL) |
| 2189 | { |
| 2190 | /* Set a "high-priority" step-resume, as we don't want |
| 2191 | user breakpoints at PC to trigger (again) when this |
| 2192 | hits. */ |
| 2193 | insert_hp_step_resume_breakpoint_at_frame (get_current_frame ()); |
| 2194 | gdb_assert (tp->control.step_resume_breakpoint->loc->permanent); |
| 2195 | |
| 2196 | tp->step_after_step_resume_breakpoint = step; |
| 2197 | } |
| 2198 | |
| 2199 | insert_breakpoints (); |
| 2200 | } |
| 2201 | else |
| 2202 | { |
| 2203 | /* There's no signal to pass, we can go ahead and skip the |
| 2204 | permanent breakpoint manually. */ |
| 2205 | if (debug_infrun) |
| 2206 | fprintf_unfiltered (gdb_stdlog, |
| 2207 | "infrun: resume: skipping permanent breakpoint\n"); |
| 2208 | gdbarch_skip_permanent_breakpoint (gdbarch, regcache); |
| 2209 | /* Update pc to reflect the new address from which we will |
| 2210 | execute instructions. */ |
| 2211 | pc = regcache_read_pc (regcache); |
| 2212 | |
| 2213 | if (step) |
| 2214 | { |
| 2215 | /* We've already advanced the PC, so the stepping part |
| 2216 | is done. Now we need to arrange for a trap to be |
| 2217 | reported to handle_inferior_event. Set a breakpoint |
| 2218 | at the current PC, and run to it. Don't update |
| 2219 | prev_pc, because if we end in |
| 2220 | switch_back_to_stepped_thread, we want the "expected |
| 2221 | thread advanced also" branch to be taken. IOW, we |
| 2222 | don't want this thread to step further from PC |
| 2223 | (overstep). */ |
| 2224 | gdb_assert (!step_over_info_valid_p ()); |
| 2225 | insert_single_step_breakpoint (gdbarch, aspace, pc); |
| 2226 | insert_breakpoints (); |
| 2227 | |
| 2228 | resume_ptid = user_visible_resume_ptid (user_step); |
| 2229 | do_target_resume (resume_ptid, 0, GDB_SIGNAL_0); |
| 2230 | discard_cleanups (old_cleanups); |
| 2231 | return; |
| 2232 | } |
| 2233 | } |
| 2234 | } |
| 2235 | |
| 2236 | /* If we have a breakpoint to step over, make sure to do a single |
| 2237 | step only. Same if we have software watchpoints. */ |
| 2238 | if (tp->control.trap_expected || bpstat_should_step ()) |
| 2239 | tp->control.may_range_step = 0; |
| 2240 | |
| 2241 | /* If enabled, step over breakpoints by executing a copy of the |
| 2242 | instruction at a different address. |
| 2243 | |
| 2244 | We can't use displaced stepping when we have a signal to deliver; |
| 2245 | the comments for displaced_step_prepare explain why. The |
| 2246 | comments in the handle_inferior event for dealing with 'random |
| 2247 | signals' explain what we do instead. |
| 2248 | |
| 2249 | We can't use displaced stepping when we are waiting for vfork_done |
| 2250 | event, displaced stepping breaks the vfork child similarly as single |
| 2251 | step software breakpoint. */ |
| 2252 | if (use_displaced_stepping (gdbarch) |
| 2253 | && tp->control.trap_expected |
| 2254 | && !step_over_info_valid_p () |
| 2255 | && sig == GDB_SIGNAL_0 |
| 2256 | && !current_inferior ()->waiting_for_vfork_done) |
| 2257 | { |
| 2258 | struct displaced_step_inferior_state *displaced; |
| 2259 | |
| 2260 | if (!displaced_step_prepare (inferior_ptid)) |
| 2261 | { |
| 2262 | /* Got placed in displaced stepping queue. Will be resumed |
| 2263 | later when all the currently queued displaced stepping |
| 2264 | requests finish. The thread is not executing at this |
| 2265 | point, and the call to set_executing will be made later. |
| 2266 | But we need to call set_running here, since from the |
| 2267 | user/frontend's point of view, threads were set running. */ |
| 2268 | set_running (user_visible_resume_ptid (user_step), 1); |
| 2269 | discard_cleanups (old_cleanups); |
| 2270 | return; |
| 2271 | } |
| 2272 | |
| 2273 | /* Update pc to reflect the new address from which we will execute |
| 2274 | instructions due to displaced stepping. */ |
| 2275 | pc = regcache_read_pc (get_thread_regcache (inferior_ptid)); |
| 2276 | |
| 2277 | displaced = get_displaced_stepping_state (ptid_get_pid (inferior_ptid)); |
| 2278 | step = gdbarch_displaced_step_hw_singlestep (gdbarch, |
| 2279 | displaced->step_closure); |
| 2280 | } |
| 2281 | |
| 2282 | /* Do we need to do it the hard way, w/temp breakpoints? */ |
| 2283 | else if (step) |
| 2284 | step = maybe_software_singlestep (gdbarch, pc); |
| 2285 | |
| 2286 | /* Currently, our software single-step implementation leads to different |
| 2287 | results than hardware single-stepping in one situation: when stepping |
| 2288 | into delivering a signal which has an associated signal handler, |
| 2289 | hardware single-step will stop at the first instruction of the handler, |
| 2290 | while software single-step will simply skip execution of the handler. |
| 2291 | |
| 2292 | For now, this difference in behavior is accepted since there is no |
| 2293 | easy way to actually implement single-stepping into a signal handler |
| 2294 | without kernel support. |
| 2295 | |
| 2296 | However, there is one scenario where this difference leads to follow-on |
| 2297 | problems: if we're stepping off a breakpoint by removing all breakpoints |
| 2298 | and then single-stepping. In this case, the software single-step |
| 2299 | behavior means that even if there is a *breakpoint* in the signal |
| 2300 | handler, GDB still would not stop. |
| 2301 | |
| 2302 | Fortunately, we can at least fix this particular issue. We detect |
| 2303 | here the case where we are about to deliver a signal while software |
| 2304 | single-stepping with breakpoints removed. In this situation, we |
| 2305 | revert the decisions to remove all breakpoints and insert single- |
| 2306 | step breakpoints, and instead we install a step-resume breakpoint |
| 2307 | at the current address, deliver the signal without stepping, and |
| 2308 | once we arrive back at the step-resume breakpoint, actually step |
| 2309 | over the breakpoint we originally wanted to step over. */ |
| 2310 | if (thread_has_single_step_breakpoints_set (tp) |
| 2311 | && sig != GDB_SIGNAL_0 |
| 2312 | && step_over_info_valid_p ()) |
| 2313 | { |
| 2314 | /* If we have nested signals or a pending signal is delivered |
| 2315 | immediately after a handler returns, might might already have |
| 2316 | a step-resume breakpoint set on the earlier handler. We cannot |
| 2317 | set another step-resume breakpoint; just continue on until the |
| 2318 | original breakpoint is hit. */ |
| 2319 | if (tp->control.step_resume_breakpoint == NULL) |
| 2320 | { |
| 2321 | insert_hp_step_resume_breakpoint_at_frame (get_current_frame ()); |
| 2322 | tp->step_after_step_resume_breakpoint = 1; |
| 2323 | } |
| 2324 | |
| 2325 | delete_single_step_breakpoints (tp); |
| 2326 | |
| 2327 | clear_step_over_info (); |
| 2328 | tp->control.trap_expected = 0; |
| 2329 | |
| 2330 | insert_breakpoints (); |
| 2331 | } |
| 2332 | |
| 2333 | /* If STEP is set, it's a request to use hardware stepping |
| 2334 | facilities. But in that case, we should never |
| 2335 | use singlestep breakpoint. */ |
| 2336 | gdb_assert (!(thread_has_single_step_breakpoints_set (tp) && step)); |
| 2337 | |
| 2338 | /* Decide the set of threads to ask the target to resume. Start |
| 2339 | by assuming everything will be resumed, than narrow the set |
| 2340 | by applying increasingly restricting conditions. */ |
| 2341 | resume_ptid = user_visible_resume_ptid (user_step); |
| 2342 | |
| 2343 | /* Even if RESUME_PTID is a wildcard, and we end up resuming less |
| 2344 | (e.g., we might need to step over a breakpoint), from the |
| 2345 | user/frontend's point of view, all threads in RESUME_PTID are now |
| 2346 | running. */ |
| 2347 | set_running (resume_ptid, 1); |
| 2348 | |
| 2349 | /* Maybe resume a single thread after all. */ |
| 2350 | if ((step || thread_has_single_step_breakpoints_set (tp)) |
| 2351 | && tp->control.trap_expected) |
| 2352 | { |
| 2353 | /* We're allowing a thread to run past a breakpoint it has |
| 2354 | hit, by single-stepping the thread with the breakpoint |
| 2355 | removed. In which case, we need to single-step only this |
| 2356 | thread, and keep others stopped, as they can miss this |
| 2357 | breakpoint if allowed to run. */ |
| 2358 | resume_ptid = inferior_ptid; |
| 2359 | } |
| 2360 | |
| 2361 | if (execution_direction != EXEC_REVERSE |
| 2362 | && step && breakpoint_inserted_here_p (aspace, pc)) |
| 2363 | { |
| 2364 | /* The only case we currently need to step a breakpoint |
| 2365 | instruction is when we have a signal to deliver. See |
| 2366 | handle_signal_stop where we handle random signals that could |
| 2367 | take out us out of the stepping range. Normally, in that |
| 2368 | case we end up continuing (instead of stepping) over the |
| 2369 | signal handler with a breakpoint at PC, but there are cases |
| 2370 | where we should _always_ single-step, even if we have a |
| 2371 | step-resume breakpoint, like when a software watchpoint is |
| 2372 | set. Assuming single-stepping and delivering a signal at the |
| 2373 | same time would takes us to the signal handler, then we could |
| 2374 | have removed the breakpoint at PC to step over it. However, |
| 2375 | some hardware step targets (like e.g., Mac OS) can't step |
| 2376 | into signal handlers, and for those, we need to leave the |
| 2377 | breakpoint at PC inserted, as otherwise if the handler |
| 2378 | recurses and executes PC again, it'll miss the breakpoint. |
| 2379 | So we leave the breakpoint inserted anyway, but we need to |
| 2380 | record that we tried to step a breakpoint instruction, so |
| 2381 | that adjust_pc_after_break doesn't end up confused. */ |
| 2382 | gdb_assert (sig != GDB_SIGNAL_0); |
| 2383 | |
| 2384 | tp->stepped_breakpoint = 1; |
| 2385 | |
| 2386 | /* Most targets can step a breakpoint instruction, thus |
| 2387 | executing it normally. But if this one cannot, just |
| 2388 | continue and we will hit it anyway. */ |
| 2389 | if (gdbarch_cannot_step_breakpoint (gdbarch)) |
| 2390 | step = 0; |
| 2391 | } |
| 2392 | |
| 2393 | if (debug_displaced |
| 2394 | && use_displaced_stepping (gdbarch) |
| 2395 | && tp->control.trap_expected |
| 2396 | && !step_over_info_valid_p ()) |
| 2397 | { |
| 2398 | struct regcache *resume_regcache = get_thread_regcache (tp->ptid); |
| 2399 | struct gdbarch *resume_gdbarch = get_regcache_arch (resume_regcache); |
| 2400 | CORE_ADDR actual_pc = regcache_read_pc (resume_regcache); |
| 2401 | gdb_byte buf[4]; |
| 2402 | |
| 2403 | fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ", |
| 2404 | paddress (resume_gdbarch, actual_pc)); |
| 2405 | read_memory (actual_pc, buf, sizeof (buf)); |
| 2406 | displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf)); |
| 2407 | } |
| 2408 | |
| 2409 | if (tp->control.may_range_step) |
| 2410 | { |
| 2411 | /* If we're resuming a thread with the PC out of the step |
| 2412 | range, then we're doing some nested/finer run control |
| 2413 | operation, like stepping the thread out of the dynamic |
| 2414 | linker or the displaced stepping scratch pad. We |
| 2415 | shouldn't have allowed a range step then. */ |
| 2416 | gdb_assert (pc_in_thread_step_range (pc, tp)); |
| 2417 | } |
| 2418 | |
| 2419 | do_target_resume (resume_ptid, step, sig); |
| 2420 | discard_cleanups (old_cleanups); |
| 2421 | } |
| 2422 | \f |
| 2423 | /* Proceeding. */ |
| 2424 | |
| 2425 | /* Clear out all variables saying what to do when inferior is continued. |
| 2426 | First do this, then set the ones you want, then call `proceed'. */ |
| 2427 | |
| 2428 | static void |
| 2429 | clear_proceed_status_thread (struct thread_info *tp) |
| 2430 | { |
| 2431 | if (debug_infrun) |
| 2432 | fprintf_unfiltered (gdb_stdlog, |
| 2433 | "infrun: clear_proceed_status_thread (%s)\n", |
| 2434 | target_pid_to_str (tp->ptid)); |
| 2435 | |
| 2436 | /* If this signal should not be seen by program, give it zero. |
| 2437 | Used for debugging signals. */ |
| 2438 | if (!signal_pass_state (tp->suspend.stop_signal)) |
| 2439 | tp->suspend.stop_signal = GDB_SIGNAL_0; |
| 2440 | |
| 2441 | tp->control.trap_expected = 0; |
| 2442 | tp->control.step_range_start = 0; |
| 2443 | tp->control.step_range_end = 0; |
| 2444 | tp->control.may_range_step = 0; |
| 2445 | tp->control.step_frame_id = null_frame_id; |
| 2446 | tp->control.step_stack_frame_id = null_frame_id; |
| 2447 | tp->control.step_over_calls = STEP_OVER_UNDEBUGGABLE; |
| 2448 | tp->control.step_start_function = NULL; |
| 2449 | tp->stop_requested = 0; |
| 2450 | |
| 2451 | tp->control.stop_step = 0; |
| 2452 | |
| 2453 | tp->control.proceed_to_finish = 0; |
| 2454 | |
| 2455 | tp->control.command_interp = NULL; |
| 2456 | tp->control.stepping_command = 0; |
| 2457 | |
| 2458 | /* Discard any remaining commands or status from previous stop. */ |
| 2459 | bpstat_clear (&tp->control.stop_bpstat); |
| 2460 | } |
| 2461 | |
| 2462 | void |
| 2463 | clear_proceed_status (int step) |
| 2464 | { |
| 2465 | if (!non_stop) |
| 2466 | { |
| 2467 | struct thread_info *tp; |
| 2468 | ptid_t resume_ptid; |
| 2469 | |
| 2470 | resume_ptid = user_visible_resume_ptid (step); |
| 2471 | |
| 2472 | /* In all-stop mode, delete the per-thread status of all threads |
| 2473 | we're about to resume, implicitly and explicitly. */ |
| 2474 | ALL_NON_EXITED_THREADS (tp) |
| 2475 | { |
| 2476 | if (!ptid_match (tp->ptid, resume_ptid)) |
| 2477 | continue; |
| 2478 | clear_proceed_status_thread (tp); |
| 2479 | } |
| 2480 | } |
| 2481 | |
| 2482 | if (!ptid_equal (inferior_ptid, null_ptid)) |
| 2483 | { |
| 2484 | struct inferior *inferior; |
| 2485 | |
| 2486 | if (non_stop) |
| 2487 | { |
| 2488 | /* If in non-stop mode, only delete the per-thread status of |
| 2489 | the current thread. */ |
| 2490 | clear_proceed_status_thread (inferior_thread ()); |
| 2491 | } |
| 2492 | |
| 2493 | inferior = current_inferior (); |
| 2494 | inferior->control.stop_soon = NO_STOP_QUIETLY; |
| 2495 | } |
| 2496 | |
| 2497 | stop_after_trap = 0; |
| 2498 | |
| 2499 | clear_step_over_info (); |
| 2500 | |
| 2501 | observer_notify_about_to_proceed (); |
| 2502 | } |
| 2503 | |
| 2504 | /* Returns true if TP is still stopped at a breakpoint that needs |
| 2505 | stepping-over in order to make progress. If the breakpoint is gone |
| 2506 | meanwhile, we can skip the whole step-over dance. */ |
| 2507 | |
| 2508 | static int |
| 2509 | thread_still_needs_step_over (struct thread_info *tp) |
| 2510 | { |
| 2511 | if (tp->stepping_over_breakpoint) |
| 2512 | { |
| 2513 | struct regcache *regcache = get_thread_regcache (tp->ptid); |
| 2514 | |
| 2515 | if (breakpoint_here_p (get_regcache_aspace (regcache), |
| 2516 | regcache_read_pc (regcache)) |
| 2517 | == ordinary_breakpoint_here) |
| 2518 | return 1; |
| 2519 | |
| 2520 | tp->stepping_over_breakpoint = 0; |
| 2521 | } |
| 2522 | |
| 2523 | return 0; |
| 2524 | } |
| 2525 | |
| 2526 | /* Returns true if scheduler locking applies. STEP indicates whether |
| 2527 | we're about to do a step/next-like command to a thread. */ |
| 2528 | |
| 2529 | static int |
| 2530 | schedlock_applies (struct thread_info *tp) |
| 2531 | { |
| 2532 | return (scheduler_mode == schedlock_on |
| 2533 | || (scheduler_mode == schedlock_step |
| 2534 | && tp->control.stepping_command)); |
| 2535 | } |
| 2536 | |
| 2537 | /* Look a thread other than EXCEPT that has previously reported a |
| 2538 | breakpoint event, and thus needs a step-over in order to make |
| 2539 | progress. Returns NULL is none is found. */ |
| 2540 | |
| 2541 | static struct thread_info * |
| 2542 | find_thread_needs_step_over (struct thread_info *except) |
| 2543 | { |
| 2544 | struct thread_info *tp, *current; |
| 2545 | |
| 2546 | /* With non-stop mode on, threads are always handled individually. */ |
| 2547 | gdb_assert (! non_stop); |
| 2548 | |
| 2549 | current = inferior_thread (); |
| 2550 | |
| 2551 | /* If scheduler locking applies, we can avoid iterating over all |
| 2552 | threads. */ |
| 2553 | if (schedlock_applies (except)) |
| 2554 | { |
| 2555 | if (except != current |
| 2556 | && thread_still_needs_step_over (current)) |
| 2557 | return current; |
| 2558 | |
| 2559 | return NULL; |
| 2560 | } |
| 2561 | |
| 2562 | ALL_NON_EXITED_THREADS (tp) |
| 2563 | { |
| 2564 | /* Ignore the EXCEPT thread. */ |
| 2565 | if (tp == except) |
| 2566 | continue; |
| 2567 | /* Ignore threads of processes we're not resuming. */ |
| 2568 | if (!sched_multi |
| 2569 | && ptid_get_pid (tp->ptid) != ptid_get_pid (inferior_ptid)) |
| 2570 | continue; |
| 2571 | |
| 2572 | if (thread_still_needs_step_over (tp)) |
| 2573 | return tp; |
| 2574 | } |
| 2575 | |
| 2576 | return NULL; |
| 2577 | } |
| 2578 | |
| 2579 | /* Basic routine for continuing the program in various fashions. |
| 2580 | |
| 2581 | ADDR is the address to resume at, or -1 for resume where stopped. |
| 2582 | SIGGNAL is the signal to give it, or 0 for none, |
| 2583 | or -1 for act according to how it stopped. |
| 2584 | STEP is nonzero if should trap after one instruction. |
| 2585 | -1 means return after that and print nothing. |
| 2586 | You should probably set various step_... variables |
| 2587 | before calling here, if you are stepping. |
| 2588 | |
| 2589 | You should call clear_proceed_status before calling proceed. */ |
| 2590 | |
| 2591 | void |
| 2592 | proceed (CORE_ADDR addr, enum gdb_signal siggnal) |
| 2593 | { |
| 2594 | struct regcache *regcache; |
| 2595 | struct gdbarch *gdbarch; |
| 2596 | struct thread_info *tp; |
| 2597 | CORE_ADDR pc; |
| 2598 | struct address_space *aspace; |
| 2599 | |
| 2600 | /* If we're stopped at a fork/vfork, follow the branch set by the |
| 2601 | "set follow-fork-mode" command; otherwise, we'll just proceed |
| 2602 | resuming the current thread. */ |
| 2603 | if (!follow_fork ()) |
| 2604 | { |
| 2605 | /* The target for some reason decided not to resume. */ |
| 2606 | normal_stop (); |
| 2607 | if (target_can_async_p ()) |
| 2608 | inferior_event_handler (INF_EXEC_COMPLETE, NULL); |
| 2609 | return; |
| 2610 | } |
| 2611 | |
| 2612 | /* We'll update this if & when we switch to a new thread. */ |
| 2613 | previous_inferior_ptid = inferior_ptid; |
| 2614 | |
| 2615 | regcache = get_current_regcache (); |
| 2616 | gdbarch = get_regcache_arch (regcache); |
| 2617 | aspace = get_regcache_aspace (regcache); |
| 2618 | pc = regcache_read_pc (regcache); |
| 2619 | tp = inferior_thread (); |
| 2620 | |
| 2621 | /* Fill in with reasonable starting values. */ |
| 2622 | init_thread_stepping_state (tp); |
| 2623 | |
| 2624 | if (addr == (CORE_ADDR) -1) |
| 2625 | { |
| 2626 | if (pc == stop_pc |
| 2627 | && breakpoint_here_p (aspace, pc) == ordinary_breakpoint_here |
| 2628 | && execution_direction != EXEC_REVERSE) |
| 2629 | /* There is a breakpoint at the address we will resume at, |
| 2630 | step one instruction before inserting breakpoints so that |
| 2631 | we do not stop right away (and report a second hit at this |
| 2632 | breakpoint). |
| 2633 | |
| 2634 | Note, we don't do this in reverse, because we won't |
| 2635 | actually be executing the breakpoint insn anyway. |
| 2636 | We'll be (un-)executing the previous instruction. */ |
| 2637 | tp->stepping_over_breakpoint = 1; |
| 2638 | else if (gdbarch_single_step_through_delay_p (gdbarch) |
| 2639 | && gdbarch_single_step_through_delay (gdbarch, |
| 2640 | get_current_frame ())) |
| 2641 | /* We stepped onto an instruction that needs to be stepped |
| 2642 | again before re-inserting the breakpoint, do so. */ |
| 2643 | tp->stepping_over_breakpoint = 1; |
| 2644 | } |
| 2645 | else |
| 2646 | { |
| 2647 | regcache_write_pc (regcache, addr); |
| 2648 | } |
| 2649 | |
| 2650 | if (siggnal != GDB_SIGNAL_DEFAULT) |
| 2651 | tp->suspend.stop_signal = siggnal; |
| 2652 | |
| 2653 | /* Record the interpreter that issued the execution command that |
| 2654 | caused this thread to resume. If the top level interpreter is |
| 2655 | MI/async, and the execution command was a CLI command |
| 2656 | (next/step/etc.), we'll want to print stop event output to the MI |
| 2657 | console channel (the stepped-to line, etc.), as if the user |
| 2658 | entered the execution command on a real GDB console. */ |
| 2659 | inferior_thread ()->control.command_interp = command_interp (); |
| 2660 | |
| 2661 | if (debug_infrun) |
| 2662 | fprintf_unfiltered (gdb_stdlog, |
| 2663 | "infrun: proceed (addr=%s, signal=%s)\n", |
| 2664 | paddress (gdbarch, addr), |
| 2665 | gdb_signal_to_symbol_string (siggnal)); |
| 2666 | |
| 2667 | if (non_stop) |
| 2668 | /* In non-stop, each thread is handled individually. The context |
| 2669 | must already be set to the right thread here. */ |
| 2670 | ; |
| 2671 | else |
| 2672 | { |
| 2673 | struct thread_info *step_over; |
| 2674 | |
| 2675 | /* In a multi-threaded task we may select another thread and |
| 2676 | then continue or step. |
| 2677 | |
| 2678 | But if the old thread was stopped at a breakpoint, it will |
| 2679 | immediately cause another breakpoint stop without any |
| 2680 | execution (i.e. it will report a breakpoint hit incorrectly). |
| 2681 | So we must step over it first. |
| 2682 | |
| 2683 | Look for a thread other than the current (TP) that reported a |
| 2684 | breakpoint hit and hasn't been resumed yet since. */ |
| 2685 | step_over = find_thread_needs_step_over (tp); |
| 2686 | if (step_over != NULL) |
| 2687 | { |
| 2688 | if (debug_infrun) |
| 2689 | fprintf_unfiltered (gdb_stdlog, |
| 2690 | "infrun: need to step-over [%s] first\n", |
| 2691 | target_pid_to_str (step_over->ptid)); |
| 2692 | |
| 2693 | /* Store the prev_pc for the stepping thread too, needed by |
| 2694 | switch_back_to_stepped_thread. */ |
| 2695 | tp->prev_pc = regcache_read_pc (get_current_regcache ()); |
| 2696 | switch_to_thread (step_over->ptid); |
| 2697 | tp = step_over; |
| 2698 | } |
| 2699 | } |
| 2700 | |
| 2701 | /* If we need to step over a breakpoint, and we're not using |
| 2702 | displaced stepping to do so, insert all breakpoints (watchpoints, |
| 2703 | etc.) but the one we're stepping over, step one instruction, and |
| 2704 | then re-insert the breakpoint when that step is finished. */ |
| 2705 | if (tp->stepping_over_breakpoint && !use_displaced_stepping (gdbarch)) |
| 2706 | { |
| 2707 | struct regcache *regcache = get_current_regcache (); |
| 2708 | |
| 2709 | set_step_over_info (get_regcache_aspace (regcache), |
| 2710 | regcache_read_pc (regcache), 0); |
| 2711 | } |
| 2712 | else |
| 2713 | clear_step_over_info (); |
| 2714 | |
| 2715 | insert_breakpoints (); |
| 2716 | |
| 2717 | tp->control.trap_expected = tp->stepping_over_breakpoint; |
| 2718 | |
| 2719 | annotate_starting (); |
| 2720 | |
| 2721 | /* Make sure that output from GDB appears before output from the |
| 2722 | inferior. */ |
| 2723 | gdb_flush (gdb_stdout); |
| 2724 | |
| 2725 | /* Refresh prev_pc value just prior to resuming. This used to be |
| 2726 | done in stop_waiting, however, setting prev_pc there did not handle |
| 2727 | scenarios such as inferior function calls or returning from |
| 2728 | a function via the return command. In those cases, the prev_pc |
| 2729 | value was not set properly for subsequent commands. The prev_pc value |
| 2730 | is used to initialize the starting line number in the ecs. With an |
| 2731 | invalid value, the gdb next command ends up stopping at the position |
| 2732 | represented by the next line table entry past our start position. |
| 2733 | On platforms that generate one line table entry per line, this |
| 2734 | is not a problem. However, on the ia64, the compiler generates |
| 2735 | extraneous line table entries that do not increase the line number. |
| 2736 | When we issue the gdb next command on the ia64 after an inferior call |
| 2737 | or a return command, we often end up a few instructions forward, still |
| 2738 | within the original line we started. |
| 2739 | |
| 2740 | An attempt was made to refresh the prev_pc at the same time the |
| 2741 | execution_control_state is initialized (for instance, just before |
| 2742 | waiting for an inferior event). But this approach did not work |
| 2743 | because of platforms that use ptrace, where the pc register cannot |
| 2744 | be read unless the inferior is stopped. At that point, we are not |
| 2745 | guaranteed the inferior is stopped and so the regcache_read_pc() call |
| 2746 | can fail. Setting the prev_pc value here ensures the value is updated |
| 2747 | correctly when the inferior is stopped. */ |
| 2748 | tp->prev_pc = regcache_read_pc (get_current_regcache ()); |
| 2749 | |
| 2750 | /* Resume inferior. */ |
| 2751 | resume (tp->suspend.stop_signal); |
| 2752 | |
| 2753 | /* Wait for it to stop (if not standalone) |
| 2754 | and in any case decode why it stopped, and act accordingly. */ |
| 2755 | /* Do this only if we are not using the event loop, or if the target |
| 2756 | does not support asynchronous execution. */ |
| 2757 | if (!target_can_async_p ()) |
| 2758 | { |
| 2759 | wait_for_inferior (); |
| 2760 | normal_stop (); |
| 2761 | } |
| 2762 | } |
| 2763 | \f |
| 2764 | |
| 2765 | /* Start remote-debugging of a machine over a serial link. */ |
| 2766 | |
| 2767 | void |
| 2768 | start_remote (int from_tty) |
| 2769 | { |
| 2770 | struct inferior *inferior; |
| 2771 | |
| 2772 | inferior = current_inferior (); |
| 2773 | inferior->control.stop_soon = STOP_QUIETLY_REMOTE; |
| 2774 | |
| 2775 | /* Always go on waiting for the target, regardless of the mode. */ |
| 2776 | /* FIXME: cagney/1999-09-23: At present it isn't possible to |
| 2777 | indicate to wait_for_inferior that a target should timeout if |
| 2778 | nothing is returned (instead of just blocking). Because of this, |
| 2779 | targets expecting an immediate response need to, internally, set |
| 2780 | things up so that the target_wait() is forced to eventually |
| 2781 | timeout. */ |
| 2782 | /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to |
| 2783 | differentiate to its caller what the state of the target is after |
| 2784 | the initial open has been performed. Here we're assuming that |
| 2785 | the target has stopped. It should be possible to eventually have |
| 2786 | target_open() return to the caller an indication that the target |
| 2787 | is currently running and GDB state should be set to the same as |
| 2788 | for an async run. */ |
| 2789 | wait_for_inferior (); |
| 2790 | |
| 2791 | /* Now that the inferior has stopped, do any bookkeeping like |
| 2792 | loading shared libraries. We want to do this before normal_stop, |
| 2793 | so that the displayed frame is up to date. */ |
| 2794 | post_create_inferior (¤t_target, from_tty); |
| 2795 | |
| 2796 | normal_stop (); |
| 2797 | } |
| 2798 | |
| 2799 | /* Initialize static vars when a new inferior begins. */ |
| 2800 | |
| 2801 | void |
| 2802 | init_wait_for_inferior (void) |
| 2803 | { |
| 2804 | /* These are meaningless until the first time through wait_for_inferior. */ |
| 2805 | |
| 2806 | breakpoint_init_inferior (inf_starting); |
| 2807 | |
| 2808 | clear_proceed_status (0); |
| 2809 | |
| 2810 | target_last_wait_ptid = minus_one_ptid; |
| 2811 | |
| 2812 | previous_inferior_ptid = inferior_ptid; |
| 2813 | |
| 2814 | /* Discard any skipped inlined frames. */ |
| 2815 | clear_inline_frame_state (minus_one_ptid); |
| 2816 | } |
| 2817 | |
| 2818 | \f |
| 2819 | /* Data to be passed around while handling an event. This data is |
| 2820 | discarded between events. */ |
| 2821 | struct execution_control_state |
| 2822 | { |
| 2823 | ptid_t ptid; |
| 2824 | /* The thread that got the event, if this was a thread event; NULL |
| 2825 | otherwise. */ |
| 2826 | struct thread_info *event_thread; |
| 2827 | |
| 2828 | struct target_waitstatus ws; |
| 2829 | int stop_func_filled_in; |
| 2830 | CORE_ADDR stop_func_start; |
| 2831 | CORE_ADDR stop_func_end; |
| 2832 | const char *stop_func_name; |
| 2833 | int wait_some_more; |
| 2834 | |
| 2835 | /* True if the event thread hit the single-step breakpoint of |
| 2836 | another thread. Thus the event doesn't cause a stop, the thread |
| 2837 | needs to be single-stepped past the single-step breakpoint before |
| 2838 | we can switch back to the original stepping thread. */ |
| 2839 | int hit_singlestep_breakpoint; |
| 2840 | }; |
| 2841 | |
| 2842 | static void handle_inferior_event (struct execution_control_state *ecs); |
| 2843 | |
| 2844 | static void handle_step_into_function (struct gdbarch *gdbarch, |
| 2845 | struct execution_control_state *ecs); |
| 2846 | static void handle_step_into_function_backward (struct gdbarch *gdbarch, |
| 2847 | struct execution_control_state *ecs); |
| 2848 | static void handle_signal_stop (struct execution_control_state *ecs); |
| 2849 | static void check_exception_resume (struct execution_control_state *, |
| 2850 | struct frame_info *); |
| 2851 | |
| 2852 | static void end_stepping_range (struct execution_control_state *ecs); |
| 2853 | static void stop_waiting (struct execution_control_state *ecs); |
| 2854 | static void prepare_to_wait (struct execution_control_state *ecs); |
| 2855 | static void keep_going (struct execution_control_state *ecs); |
| 2856 | static void process_event_stop_test (struct execution_control_state *ecs); |
| 2857 | static int switch_back_to_stepped_thread (struct execution_control_state *ecs); |
| 2858 | |
| 2859 | /* Callback for iterate over threads. If the thread is stopped, but |
| 2860 | the user/frontend doesn't know about that yet, go through |
| 2861 | normal_stop, as if the thread had just stopped now. ARG points at |
| 2862 | a ptid. If PTID is MINUS_ONE_PTID, applies to all threads. If |
| 2863 | ptid_is_pid(PTID) is true, applies to all threads of the process |
| 2864 | pointed at by PTID. Otherwise, apply only to the thread pointed by |
| 2865 | PTID. */ |
| 2866 | |
| 2867 | static int |
| 2868 | infrun_thread_stop_requested_callback (struct thread_info *info, void *arg) |
| 2869 | { |
| 2870 | ptid_t ptid = * (ptid_t *) arg; |
| 2871 | |
| 2872 | if ((ptid_equal (info->ptid, ptid) |
| 2873 | || ptid_equal (minus_one_ptid, ptid) |
| 2874 | || (ptid_is_pid (ptid) |
| 2875 | && ptid_get_pid (ptid) == ptid_get_pid (info->ptid))) |
| 2876 | && is_running (info->ptid) |
| 2877 | && !is_executing (info->ptid)) |
| 2878 | { |
| 2879 | struct cleanup *old_chain; |
| 2880 | struct execution_control_state ecss; |
| 2881 | struct execution_control_state *ecs = &ecss; |
| 2882 | |
| 2883 | memset (ecs, 0, sizeof (*ecs)); |
| 2884 | |
| 2885 | old_chain = make_cleanup_restore_current_thread (); |
| 2886 | |
| 2887 | overlay_cache_invalid = 1; |
| 2888 | /* Flush target cache before starting to handle each event. |
| 2889 | Target was running and cache could be stale. This is just a |
| 2890 | heuristic. Running threads may modify target memory, but we |
| 2891 | don't get any event. */ |
| 2892 | target_dcache_invalidate (); |
| 2893 | |
| 2894 | /* Go through handle_inferior_event/normal_stop, so we always |
| 2895 | have consistent output as if the stop event had been |
| 2896 | reported. */ |
| 2897 | ecs->ptid = info->ptid; |
| 2898 | ecs->event_thread = find_thread_ptid (info->ptid); |
| 2899 | ecs->ws.kind = TARGET_WAITKIND_STOPPED; |
| 2900 | ecs->ws.value.sig = GDB_SIGNAL_0; |
| 2901 | |
| 2902 | handle_inferior_event (ecs); |
| 2903 | |
| 2904 | if (!ecs->wait_some_more) |
| 2905 | { |
| 2906 | struct thread_info *tp; |
| 2907 | |
| 2908 | normal_stop (); |
| 2909 | |
| 2910 | /* Finish off the continuations. */ |
| 2911 | tp = inferior_thread (); |
| 2912 | do_all_intermediate_continuations_thread (tp, 1); |
| 2913 | do_all_continuations_thread (tp, 1); |
| 2914 | } |
| 2915 | |
| 2916 | do_cleanups (old_chain); |
| 2917 | } |
| 2918 | |
| 2919 | return 0; |
| 2920 | } |
| 2921 | |
| 2922 | /* This function is attached as a "thread_stop_requested" observer. |
| 2923 | Cleanup local state that assumed the PTID was to be resumed, and |
| 2924 | report the stop to the frontend. */ |
| 2925 | |
| 2926 | static void |
| 2927 | infrun_thread_stop_requested (ptid_t ptid) |
| 2928 | { |
| 2929 | struct displaced_step_inferior_state *displaced; |
| 2930 | |
| 2931 | /* PTID was requested to stop. Remove it from the displaced |
| 2932 | stepping queue, so we don't try to resume it automatically. */ |
| 2933 | |
| 2934 | for (displaced = displaced_step_inferior_states; |
| 2935 | displaced; |
| 2936 | displaced = displaced->next) |
| 2937 | { |
| 2938 | struct displaced_step_request *it, **prev_next_p; |
| 2939 | |
| 2940 | it = displaced->step_request_queue; |
| 2941 | prev_next_p = &displaced->step_request_queue; |
| 2942 | while (it) |
| 2943 | { |
| 2944 | if (ptid_match (it->ptid, ptid)) |
| 2945 | { |
| 2946 | *prev_next_p = it->next; |
| 2947 | it->next = NULL; |
| 2948 | xfree (it); |
| 2949 | } |
| 2950 | else |
| 2951 | { |
| 2952 | prev_next_p = &it->next; |
| 2953 | } |
| 2954 | |
| 2955 | it = *prev_next_p; |
| 2956 | } |
| 2957 | } |
| 2958 | |
| 2959 | iterate_over_threads (infrun_thread_stop_requested_callback, &ptid); |
| 2960 | } |
| 2961 | |
| 2962 | static void |
| 2963 | infrun_thread_thread_exit (struct thread_info *tp, int silent) |
| 2964 | { |
| 2965 | if (ptid_equal (target_last_wait_ptid, tp->ptid)) |
| 2966 | nullify_last_target_wait_ptid (); |
| 2967 | } |
| 2968 | |
| 2969 | /* Delete the step resume, single-step and longjmp/exception resume |
| 2970 | breakpoints of TP. */ |
| 2971 | |
| 2972 | static void |
| 2973 | delete_thread_infrun_breakpoints (struct thread_info *tp) |
| 2974 | { |
| 2975 | delete_step_resume_breakpoint (tp); |
| 2976 | delete_exception_resume_breakpoint (tp); |
| 2977 | delete_single_step_breakpoints (tp); |
| 2978 | } |
| 2979 | |
| 2980 | /* If the target still has execution, call FUNC for each thread that |
| 2981 | just stopped. In all-stop, that's all the non-exited threads; in |
| 2982 | non-stop, that's the current thread, only. */ |
| 2983 | |
| 2984 | typedef void (*for_each_just_stopped_thread_callback_func) |
| 2985 | (struct thread_info *tp); |
| 2986 | |
| 2987 | static void |
| 2988 | for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func) |
| 2989 | { |
| 2990 | if (!target_has_execution || ptid_equal (inferior_ptid, null_ptid)) |
| 2991 | return; |
| 2992 | |
| 2993 | if (non_stop) |
| 2994 | { |
| 2995 | /* If in non-stop mode, only the current thread stopped. */ |
| 2996 | func (inferior_thread ()); |
| 2997 | } |
| 2998 | else |
| 2999 | { |
| 3000 | struct thread_info *tp; |
| 3001 | |
| 3002 | /* In all-stop mode, all threads have stopped. */ |
| 3003 | ALL_NON_EXITED_THREADS (tp) |
| 3004 | { |
| 3005 | func (tp); |
| 3006 | } |
| 3007 | } |
| 3008 | } |
| 3009 | |
| 3010 | /* Delete the step resume and longjmp/exception resume breakpoints of |
| 3011 | the threads that just stopped. */ |
| 3012 | |
| 3013 | static void |
| 3014 | delete_just_stopped_threads_infrun_breakpoints (void) |
| 3015 | { |
| 3016 | for_each_just_stopped_thread (delete_thread_infrun_breakpoints); |
| 3017 | } |
| 3018 | |
| 3019 | /* Delete the single-step breakpoints of the threads that just |
| 3020 | stopped. */ |
| 3021 | |
| 3022 | static void |
| 3023 | delete_just_stopped_threads_single_step_breakpoints (void) |
| 3024 | { |
| 3025 | for_each_just_stopped_thread (delete_single_step_breakpoints); |
| 3026 | } |
| 3027 | |
| 3028 | /* A cleanup wrapper. */ |
| 3029 | |
| 3030 | static void |
| 3031 | delete_just_stopped_threads_infrun_breakpoints_cleanup (void *arg) |
| 3032 | { |
| 3033 | delete_just_stopped_threads_infrun_breakpoints (); |
| 3034 | } |
| 3035 | |
| 3036 | /* Pretty print the results of target_wait, for debugging purposes. */ |
| 3037 | |
| 3038 | static void |
| 3039 | print_target_wait_results (ptid_t waiton_ptid, ptid_t result_ptid, |
| 3040 | const struct target_waitstatus *ws) |
| 3041 | { |
| 3042 | char *status_string = target_waitstatus_to_string (ws); |
| 3043 | struct ui_file *tmp_stream = mem_fileopen (); |
| 3044 | char *text; |
| 3045 | |
| 3046 | /* The text is split over several lines because it was getting too long. |
| 3047 | Call fprintf_unfiltered (gdb_stdlog) once so that the text is still |
| 3048 | output as a unit; we want only one timestamp printed if debug_timestamp |
| 3049 | is set. */ |
| 3050 | |
| 3051 | fprintf_unfiltered (tmp_stream, |
| 3052 | "infrun: target_wait (%d.%ld.%ld", |
| 3053 | ptid_get_pid (waiton_ptid), |
| 3054 | ptid_get_lwp (waiton_ptid), |
| 3055 | ptid_get_tid (waiton_ptid)); |
| 3056 | if (ptid_get_pid (waiton_ptid) != -1) |
| 3057 | fprintf_unfiltered (tmp_stream, |
| 3058 | " [%s]", target_pid_to_str (waiton_ptid)); |
| 3059 | fprintf_unfiltered (tmp_stream, ", status) =\n"); |
| 3060 | fprintf_unfiltered (tmp_stream, |
| 3061 | "infrun: %d.%ld.%ld [%s],\n", |
| 3062 | ptid_get_pid (result_ptid), |
| 3063 | ptid_get_lwp (result_ptid), |
| 3064 | ptid_get_tid (result_ptid), |
| 3065 | target_pid_to_str (result_ptid)); |
| 3066 | fprintf_unfiltered (tmp_stream, |
| 3067 | "infrun: %s\n", |
| 3068 | status_string); |
| 3069 | |
| 3070 | text = ui_file_xstrdup (tmp_stream, NULL); |
| 3071 | |
| 3072 | /* This uses %s in part to handle %'s in the text, but also to avoid |
| 3073 | a gcc error: the format attribute requires a string literal. */ |
| 3074 | fprintf_unfiltered (gdb_stdlog, "%s", text); |
| 3075 | |
| 3076 | xfree (status_string); |
| 3077 | xfree (text); |
| 3078 | ui_file_delete (tmp_stream); |
| 3079 | } |
| 3080 | |
| 3081 | /* Prepare and stabilize the inferior for detaching it. E.g., |
| 3082 | detaching while a thread is displaced stepping is a recipe for |
| 3083 | crashing it, as nothing would readjust the PC out of the scratch |
| 3084 | pad. */ |
| 3085 | |
| 3086 | void |
| 3087 | prepare_for_detach (void) |
| 3088 | { |
| 3089 | struct inferior *inf = current_inferior (); |
| 3090 | ptid_t pid_ptid = pid_to_ptid (inf->pid); |
| 3091 | struct cleanup *old_chain_1; |
| 3092 | struct displaced_step_inferior_state *displaced; |
| 3093 | |
| 3094 | displaced = get_displaced_stepping_state (inf->pid); |
| 3095 | |
| 3096 | /* Is any thread of this process displaced stepping? If not, |
| 3097 | there's nothing else to do. */ |
| 3098 | if (displaced == NULL || ptid_equal (displaced->step_ptid, null_ptid)) |
| 3099 | return; |
| 3100 | |
| 3101 | if (debug_infrun) |
| 3102 | fprintf_unfiltered (gdb_stdlog, |
| 3103 | "displaced-stepping in-process while detaching"); |
| 3104 | |
| 3105 | old_chain_1 = make_cleanup_restore_integer (&inf->detaching); |
| 3106 | inf->detaching = 1; |
| 3107 | |
| 3108 | while (!ptid_equal (displaced->step_ptid, null_ptid)) |
| 3109 | { |
| 3110 | struct cleanup *old_chain_2; |
| 3111 | struct execution_control_state ecss; |
| 3112 | struct execution_control_state *ecs; |
| 3113 | |
| 3114 | ecs = &ecss; |
| 3115 | memset (ecs, 0, sizeof (*ecs)); |
| 3116 | |
| 3117 | overlay_cache_invalid = 1; |
| 3118 | /* Flush target cache before starting to handle each event. |
| 3119 | Target was running and cache could be stale. This is just a |
| 3120 | heuristic. Running threads may modify target memory, but we |
| 3121 | don't get any event. */ |
| 3122 | target_dcache_invalidate (); |
| 3123 | |
| 3124 | if (deprecated_target_wait_hook) |
| 3125 | ecs->ptid = deprecated_target_wait_hook (pid_ptid, &ecs->ws, 0); |
| 3126 | else |
| 3127 | ecs->ptid = target_wait (pid_ptid, &ecs->ws, 0); |
| 3128 | |
| 3129 | if (debug_infrun) |
| 3130 | print_target_wait_results (pid_ptid, ecs->ptid, &ecs->ws); |
| 3131 | |
| 3132 | /* If an error happens while handling the event, propagate GDB's |
| 3133 | knowledge of the executing state to the frontend/user running |
| 3134 | state. */ |
| 3135 | old_chain_2 = make_cleanup (finish_thread_state_cleanup, |
| 3136 | &minus_one_ptid); |
| 3137 | |
| 3138 | /* Now figure out what to do with the result of the result. */ |
| 3139 | handle_inferior_event (ecs); |
| 3140 | |
| 3141 | /* No error, don't finish the state yet. */ |
| 3142 | discard_cleanups (old_chain_2); |
| 3143 | |
| 3144 | /* Breakpoints and watchpoints are not installed on the target |
| 3145 | at this point, and signals are passed directly to the |
| 3146 | inferior, so this must mean the process is gone. */ |
| 3147 | if (!ecs->wait_some_more) |
| 3148 | { |
| 3149 | discard_cleanups (old_chain_1); |
| 3150 | error (_("Program exited while detaching")); |
| 3151 | } |
| 3152 | } |
| 3153 | |
| 3154 | discard_cleanups (old_chain_1); |
| 3155 | } |
| 3156 | |
| 3157 | /* Wait for control to return from inferior to debugger. |
| 3158 | |
| 3159 | If inferior gets a signal, we may decide to start it up again |
| 3160 | instead of returning. That is why there is a loop in this function. |
| 3161 | When this function actually returns it means the inferior |
| 3162 | should be left stopped and GDB should read more commands. */ |
| 3163 | |
| 3164 | void |
| 3165 | wait_for_inferior (void) |
| 3166 | { |
| 3167 | struct cleanup *old_cleanups; |
| 3168 | struct cleanup *thread_state_chain; |
| 3169 | |
| 3170 | if (debug_infrun) |
| 3171 | fprintf_unfiltered |
| 3172 | (gdb_stdlog, "infrun: wait_for_inferior ()\n"); |
| 3173 | |
| 3174 | old_cleanups |
| 3175 | = make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup, |
| 3176 | NULL); |
| 3177 | |
| 3178 | /* If an error happens while handling the event, propagate GDB's |
| 3179 | knowledge of the executing state to the frontend/user running |
| 3180 | state. */ |
| 3181 | thread_state_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid); |
| 3182 | |
| 3183 | while (1) |
| 3184 | { |
| 3185 | struct execution_control_state ecss; |
| 3186 | struct execution_control_state *ecs = &ecss; |
| 3187 | ptid_t waiton_ptid = minus_one_ptid; |
| 3188 | |
| 3189 | memset (ecs, 0, sizeof (*ecs)); |
| 3190 | |
| 3191 | overlay_cache_invalid = 1; |
| 3192 | |
| 3193 | /* Flush target cache before starting to handle each event. |
| 3194 | Target was running and cache could be stale. This is just a |
| 3195 | heuristic. Running threads may modify target memory, but we |
| 3196 | don't get any event. */ |
| 3197 | target_dcache_invalidate (); |
| 3198 | |
| 3199 | if (deprecated_target_wait_hook) |
| 3200 | ecs->ptid = deprecated_target_wait_hook (waiton_ptid, &ecs->ws, 0); |
| 3201 | else |
| 3202 | ecs->ptid = target_wait (waiton_ptid, &ecs->ws, 0); |
| 3203 | |
| 3204 | if (debug_infrun) |
| 3205 | print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws); |
| 3206 | |
| 3207 | /* Now figure out what to do with the result of the result. */ |
| 3208 | handle_inferior_event (ecs); |
| 3209 | |
| 3210 | if (!ecs->wait_some_more) |
| 3211 | break; |
| 3212 | } |
| 3213 | |
| 3214 | /* No error, don't finish the state yet. */ |
| 3215 | discard_cleanups (thread_state_chain); |
| 3216 | |
| 3217 | do_cleanups (old_cleanups); |
| 3218 | } |
| 3219 | |
| 3220 | /* Cleanup that reinstalls the readline callback handler, if the |
| 3221 | target is running in the background. If while handling the target |
| 3222 | event something triggered a secondary prompt, like e.g., a |
| 3223 | pagination prompt, we'll have removed the callback handler (see |
| 3224 | gdb_readline_wrapper_line). Need to do this as we go back to the |
| 3225 | event loop, ready to process further input. Note this has no |
| 3226 | effect if the handler hasn't actually been removed, because calling |
| 3227 | rl_callback_handler_install resets the line buffer, thus losing |
| 3228 | input. */ |
| 3229 | |
| 3230 | static void |
| 3231 | reinstall_readline_callback_handler_cleanup (void *arg) |
| 3232 | { |
| 3233 | if (!interpreter_async) |
| 3234 | { |
| 3235 | /* We're not going back to the top level event loop yet. Don't |
| 3236 | install the readline callback, as it'd prep the terminal, |
| 3237 | readline-style (raw, noecho) (e.g., --batch). We'll install |
| 3238 | it the next time the prompt is displayed, when we're ready |
| 3239 | for input. */ |
| 3240 | return; |
| 3241 | } |
| 3242 | |
| 3243 | if (async_command_editing_p && !sync_execution) |
| 3244 | gdb_rl_callback_handler_reinstall (); |
| 3245 | } |
| 3246 | |
| 3247 | /* Asynchronous version of wait_for_inferior. It is called by the |
| 3248 | event loop whenever a change of state is detected on the file |
| 3249 | descriptor corresponding to the target. It can be called more than |
| 3250 | once to complete a single execution command. In such cases we need |
| 3251 | to keep the state in a global variable ECSS. If it is the last time |
| 3252 | that this function is called for a single execution command, then |
| 3253 | report to the user that the inferior has stopped, and do the |
| 3254 | necessary cleanups. */ |
| 3255 | |
| 3256 | void |
| 3257 | fetch_inferior_event (void *client_data) |
| 3258 | { |
| 3259 | struct execution_control_state ecss; |
| 3260 | struct execution_control_state *ecs = &ecss; |
| 3261 | struct cleanup *old_chain = make_cleanup (null_cleanup, NULL); |
| 3262 | struct cleanup *ts_old_chain; |
| 3263 | int was_sync = sync_execution; |
| 3264 | int cmd_done = 0; |
| 3265 | ptid_t waiton_ptid = minus_one_ptid; |
| 3266 | |
| 3267 | memset (ecs, 0, sizeof (*ecs)); |
| 3268 | |
| 3269 | /* End up with readline processing input, if necessary. */ |
| 3270 | make_cleanup (reinstall_readline_callback_handler_cleanup, NULL); |
| 3271 | |
| 3272 | /* We're handling a live event, so make sure we're doing live |
| 3273 | debugging. If we're looking at traceframes while the target is |
| 3274 | running, we're going to need to get back to that mode after |
| 3275 | handling the event. */ |
| 3276 | if (non_stop) |
| 3277 | { |
| 3278 | make_cleanup_restore_current_traceframe (); |
| 3279 | set_current_traceframe (-1); |
| 3280 | } |
| 3281 | |
| 3282 | if (non_stop) |
| 3283 | /* In non-stop mode, the user/frontend should not notice a thread |
| 3284 | switch due to internal events. Make sure we reverse to the |
| 3285 | user selected thread and frame after handling the event and |
| 3286 | running any breakpoint commands. */ |
| 3287 | make_cleanup_restore_current_thread (); |
| 3288 | |
| 3289 | overlay_cache_invalid = 1; |
| 3290 | /* Flush target cache before starting to handle each event. Target |
| 3291 | was running and cache could be stale. This is just a heuristic. |
| 3292 | Running threads may modify target memory, but we don't get any |
| 3293 | event. */ |
| 3294 | target_dcache_invalidate (); |
| 3295 | |
| 3296 | make_cleanup_restore_integer (&execution_direction); |
| 3297 | execution_direction = target_execution_direction (); |
| 3298 | |
| 3299 | if (deprecated_target_wait_hook) |
| 3300 | ecs->ptid = |
| 3301 | deprecated_target_wait_hook (waiton_ptid, &ecs->ws, TARGET_WNOHANG); |
| 3302 | else |
| 3303 | ecs->ptid = target_wait (waiton_ptid, &ecs->ws, TARGET_WNOHANG); |
| 3304 | |
| 3305 | if (debug_infrun) |
| 3306 | print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws); |
| 3307 | |
| 3308 | /* If an error happens while handling the event, propagate GDB's |
| 3309 | knowledge of the executing state to the frontend/user running |
| 3310 | state. */ |
| 3311 | if (!non_stop) |
| 3312 | ts_old_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid); |
| 3313 | else |
| 3314 | ts_old_chain = make_cleanup (finish_thread_state_cleanup, &ecs->ptid); |
| 3315 | |
| 3316 | /* Get executed before make_cleanup_restore_current_thread above to apply |
| 3317 | still for the thread which has thrown the exception. */ |
| 3318 | make_bpstat_clear_actions_cleanup (); |
| 3319 | |
| 3320 | make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup, NULL); |
| 3321 | |
| 3322 | /* Now figure out what to do with the result of the result. */ |
| 3323 | handle_inferior_event (ecs); |
| 3324 | |
| 3325 | if (!ecs->wait_some_more) |
| 3326 | { |
| 3327 | struct inferior *inf = find_inferior_ptid (ecs->ptid); |
| 3328 | |
| 3329 | delete_just_stopped_threads_infrun_breakpoints (); |
| 3330 | |
| 3331 | /* We may not find an inferior if this was a process exit. */ |
| 3332 | if (inf == NULL || inf->control.stop_soon == NO_STOP_QUIETLY) |
| 3333 | normal_stop (); |
| 3334 | |
| 3335 | if (target_has_execution |
| 3336 | && ecs->ws.kind != TARGET_WAITKIND_NO_RESUMED |
| 3337 | && ecs->ws.kind != TARGET_WAITKIND_EXITED |
| 3338 | && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED |
| 3339 | && ecs->event_thread->step_multi |
| 3340 | && ecs->event_thread->control.stop_step) |
| 3341 | inferior_event_handler (INF_EXEC_CONTINUE, NULL); |
| 3342 | else |
| 3343 | { |
| 3344 | inferior_event_handler (INF_EXEC_COMPLETE, NULL); |
| 3345 | cmd_done = 1; |
| 3346 | } |
| 3347 | } |
| 3348 | |
| 3349 | /* No error, don't finish the thread states yet. */ |
| 3350 | discard_cleanups (ts_old_chain); |
| 3351 | |
| 3352 | /* Revert thread and frame. */ |
| 3353 | do_cleanups (old_chain); |
| 3354 | |
| 3355 | /* If the inferior was in sync execution mode, and now isn't, |
| 3356 | restore the prompt (a synchronous execution command has finished, |
| 3357 | and we're ready for input). */ |
| 3358 | if (interpreter_async && was_sync && !sync_execution) |
| 3359 | observer_notify_sync_execution_done (); |
| 3360 | |
| 3361 | if (cmd_done |
| 3362 | && !was_sync |
| 3363 | && exec_done_display_p |
| 3364 | && (ptid_equal (inferior_ptid, null_ptid) |
| 3365 | || !is_running (inferior_ptid))) |
| 3366 | printf_unfiltered (_("completed.\n")); |
| 3367 | } |
| 3368 | |
| 3369 | /* Record the frame and location we're currently stepping through. */ |
| 3370 | void |
| 3371 | set_step_info (struct frame_info *frame, struct symtab_and_line sal) |
| 3372 | { |
| 3373 | struct thread_info *tp = inferior_thread (); |
| 3374 | |
| 3375 | tp->control.step_frame_id = get_frame_id (frame); |
| 3376 | tp->control.step_stack_frame_id = get_stack_frame_id (frame); |
| 3377 | |
| 3378 | tp->current_symtab = sal.symtab; |
| 3379 | tp->current_line = sal.line; |
| 3380 | } |
| 3381 | |
| 3382 | /* Clear context switchable stepping state. */ |
| 3383 | |
| 3384 | void |
| 3385 | init_thread_stepping_state (struct thread_info *tss) |
| 3386 | { |
| 3387 | tss->stepped_breakpoint = 0; |
| 3388 | tss->stepping_over_breakpoint = 0; |
| 3389 | tss->stepping_over_watchpoint = 0; |
| 3390 | tss->step_after_step_resume_breakpoint = 0; |
| 3391 | } |
| 3392 | |
| 3393 | /* Set the cached copy of the last ptid/waitstatus. */ |
| 3394 | |
| 3395 | static void |
| 3396 | set_last_target_status (ptid_t ptid, struct target_waitstatus status) |
| 3397 | { |
| 3398 | target_last_wait_ptid = ptid; |
| 3399 | target_last_waitstatus = status; |
| 3400 | } |
| 3401 | |
| 3402 | /* Return the cached copy of the last pid/waitstatus returned by |
| 3403 | target_wait()/deprecated_target_wait_hook(). The data is actually |
| 3404 | cached by handle_inferior_event(), which gets called immediately |
| 3405 | after target_wait()/deprecated_target_wait_hook(). */ |
| 3406 | |
| 3407 | void |
| 3408 | get_last_target_status (ptid_t *ptidp, struct target_waitstatus *status) |
| 3409 | { |
| 3410 | *ptidp = target_last_wait_ptid; |
| 3411 | *status = target_last_waitstatus; |
| 3412 | } |
| 3413 | |
| 3414 | void |
| 3415 | nullify_last_target_wait_ptid (void) |
| 3416 | { |
| 3417 | target_last_wait_ptid = minus_one_ptid; |
| 3418 | } |
| 3419 | |
| 3420 | /* Switch thread contexts. */ |
| 3421 | |
| 3422 | static void |
| 3423 | context_switch (ptid_t ptid) |
| 3424 | { |
| 3425 | if (debug_infrun && !ptid_equal (ptid, inferior_ptid)) |
| 3426 | { |
| 3427 | fprintf_unfiltered (gdb_stdlog, "infrun: Switching context from %s ", |
| 3428 | target_pid_to_str (inferior_ptid)); |
| 3429 | fprintf_unfiltered (gdb_stdlog, "to %s\n", |
| 3430 | target_pid_to_str (ptid)); |
| 3431 | } |
| 3432 | |
| 3433 | switch_to_thread (ptid); |
| 3434 | } |
| 3435 | |
| 3436 | static void |
| 3437 | adjust_pc_after_break (struct execution_control_state *ecs) |
| 3438 | { |
| 3439 | struct regcache *regcache; |
| 3440 | struct gdbarch *gdbarch; |
| 3441 | struct address_space *aspace; |
| 3442 | CORE_ADDR breakpoint_pc, decr_pc; |
| 3443 | |
| 3444 | /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If |
| 3445 | we aren't, just return. |
| 3446 | |
| 3447 | We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not |
| 3448 | affected by gdbarch_decr_pc_after_break. Other waitkinds which are |
| 3449 | implemented by software breakpoints should be handled through the normal |
| 3450 | breakpoint layer. |
| 3451 | |
| 3452 | NOTE drow/2004-01-31: On some targets, breakpoints may generate |
| 3453 | different signals (SIGILL or SIGEMT for instance), but it is less |
| 3454 | clear where the PC is pointing afterwards. It may not match |
| 3455 | gdbarch_decr_pc_after_break. I don't know any specific target that |
| 3456 | generates these signals at breakpoints (the code has been in GDB since at |
| 3457 | least 1992) so I can not guess how to handle them here. |
| 3458 | |
| 3459 | In earlier versions of GDB, a target with |
| 3460 | gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a |
| 3461 | watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any |
| 3462 | target with both of these set in GDB history, and it seems unlikely to be |
| 3463 | correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */ |
| 3464 | |
| 3465 | if (ecs->ws.kind != TARGET_WAITKIND_STOPPED) |
| 3466 | return; |
| 3467 | |
| 3468 | if (ecs->ws.value.sig != GDB_SIGNAL_TRAP) |
| 3469 | return; |
| 3470 | |
| 3471 | /* In reverse execution, when a breakpoint is hit, the instruction |
| 3472 | under it has already been de-executed. The reported PC always |
| 3473 | points at the breakpoint address, so adjusting it further would |
| 3474 | be wrong. E.g., consider this case on a decr_pc_after_break == 1 |
| 3475 | architecture: |
| 3476 | |
| 3477 | B1 0x08000000 : INSN1 |
| 3478 | B2 0x08000001 : INSN2 |
| 3479 | 0x08000002 : INSN3 |
| 3480 | PC -> 0x08000003 : INSN4 |
| 3481 | |
| 3482 | Say you're stopped at 0x08000003 as above. Reverse continuing |
| 3483 | from that point should hit B2 as below. Reading the PC when the |
| 3484 | SIGTRAP is reported should read 0x08000001 and INSN2 should have |
| 3485 | been de-executed already. |
| 3486 | |
| 3487 | B1 0x08000000 : INSN1 |
| 3488 | B2 PC -> 0x08000001 : INSN2 |
| 3489 | 0x08000002 : INSN3 |
| 3490 | 0x08000003 : INSN4 |
| 3491 | |
| 3492 | We can't apply the same logic as for forward execution, because |
| 3493 | we would wrongly adjust the PC to 0x08000000, since there's a |
| 3494 | breakpoint at PC - 1. We'd then report a hit on B1, although |
| 3495 | INSN1 hadn't been de-executed yet. Doing nothing is the correct |
| 3496 | behaviour. */ |
| 3497 | if (execution_direction == EXEC_REVERSE) |
| 3498 | return; |
| 3499 | |
| 3500 | /* If the target can tell whether the thread hit a SW breakpoint, |
| 3501 | trust it. Targets that can tell also adjust the PC |
| 3502 | themselves. */ |
| 3503 | if (target_supports_stopped_by_sw_breakpoint ()) |
| 3504 | return; |
| 3505 | |
| 3506 | /* Note that relying on whether a breakpoint is planted in memory to |
| 3507 | determine this can fail. E.g,. the breakpoint could have been |
| 3508 | removed since. Or the thread could have been told to step an |
| 3509 | instruction the size of a breakpoint instruction, and only |
| 3510 | _after_ was a breakpoint inserted at its address. */ |
| 3511 | |
| 3512 | /* If this target does not decrement the PC after breakpoints, then |
| 3513 | we have nothing to do. */ |
| 3514 | regcache = get_thread_regcache (ecs->ptid); |
| 3515 | gdbarch = get_regcache_arch (regcache); |
| 3516 | |
| 3517 | decr_pc = gdbarch_decr_pc_after_break (gdbarch); |
| 3518 | if (decr_pc == 0) |
| 3519 | return; |
| 3520 | |
| 3521 | aspace = get_regcache_aspace (regcache); |
| 3522 | |
| 3523 | /* Find the location where (if we've hit a breakpoint) the |
| 3524 | breakpoint would be. */ |
| 3525 | breakpoint_pc = regcache_read_pc (regcache) - decr_pc; |
| 3526 | |
| 3527 | /* If the target can't tell whether a software breakpoint triggered, |
| 3528 | fallback to figuring it out based on breakpoints we think were |
| 3529 | inserted in the target, and on whether the thread was stepped or |
| 3530 | continued. */ |
| 3531 | |
| 3532 | /* Check whether there actually is a software breakpoint inserted at |
| 3533 | that location. |
| 3534 | |
| 3535 | If in non-stop mode, a race condition is possible where we've |
| 3536 | removed a breakpoint, but stop events for that breakpoint were |
| 3537 | already queued and arrive later. To suppress those spurious |
| 3538 | SIGTRAPs, we keep a list of such breakpoint locations for a bit, |
| 3539 | and retire them after a number of stop events are reported. Note |
| 3540 | this is an heuristic and can thus get confused. The real fix is |
| 3541 | to get the "stopped by SW BP and needs adjustment" info out of |
| 3542 | the target/kernel (and thus never reach here; see above). */ |
| 3543 | if (software_breakpoint_inserted_here_p (aspace, breakpoint_pc) |
| 3544 | || (non_stop && moribund_breakpoint_here_p (aspace, breakpoint_pc))) |
| 3545 | { |
| 3546 | struct cleanup *old_cleanups = make_cleanup (null_cleanup, NULL); |
| 3547 | |
| 3548 | if (record_full_is_used ()) |
| 3549 | record_full_gdb_operation_disable_set (); |
| 3550 | |
| 3551 | /* When using hardware single-step, a SIGTRAP is reported for both |
| 3552 | a completed single-step and a software breakpoint. Need to |
| 3553 | differentiate between the two, as the latter needs adjusting |
| 3554 | but the former does not. |
| 3555 | |
| 3556 | The SIGTRAP can be due to a completed hardware single-step only if |
| 3557 | - we didn't insert software single-step breakpoints |
| 3558 | - this thread is currently being stepped |
| 3559 | |
| 3560 | If any of these events did not occur, we must have stopped due |
| 3561 | to hitting a software breakpoint, and have to back up to the |
| 3562 | breakpoint address. |
| 3563 | |
| 3564 | As a special case, we could have hardware single-stepped a |
| 3565 | software breakpoint. In this case (prev_pc == breakpoint_pc), |
| 3566 | we also need to back up to the breakpoint address. */ |
| 3567 | |
| 3568 | if (thread_has_single_step_breakpoints_set (ecs->event_thread) |
| 3569 | || !currently_stepping (ecs->event_thread) |
| 3570 | || (ecs->event_thread->stepped_breakpoint |
| 3571 | && ecs->event_thread->prev_pc == breakpoint_pc)) |
| 3572 | regcache_write_pc (regcache, breakpoint_pc); |
| 3573 | |
| 3574 | do_cleanups (old_cleanups); |
| 3575 | } |
| 3576 | } |
| 3577 | |
| 3578 | static int |
| 3579 | stepped_in_from (struct frame_info *frame, struct frame_id step_frame_id) |
| 3580 | { |
| 3581 | for (frame = get_prev_frame (frame); |
| 3582 | frame != NULL; |
| 3583 | frame = get_prev_frame (frame)) |
| 3584 | { |
| 3585 | if (frame_id_eq (get_frame_id (frame), step_frame_id)) |
| 3586 | return 1; |
| 3587 | if (get_frame_type (frame) != INLINE_FRAME) |
| 3588 | break; |
| 3589 | } |
| 3590 | |
| 3591 | return 0; |
| 3592 | } |
| 3593 | |
| 3594 | /* Auxiliary function that handles syscall entry/return events. |
| 3595 | It returns 1 if the inferior should keep going (and GDB |
| 3596 | should ignore the event), or 0 if the event deserves to be |
| 3597 | processed. */ |
| 3598 | |
| 3599 | static int |
| 3600 | handle_syscall_event (struct execution_control_state *ecs) |
| 3601 | { |
| 3602 | struct regcache *regcache; |
| 3603 | int syscall_number; |
| 3604 | |
| 3605 | if (!ptid_equal (ecs->ptid, inferior_ptid)) |
| 3606 | context_switch (ecs->ptid); |
| 3607 | |
| 3608 | regcache = get_thread_regcache (ecs->ptid); |
| 3609 | syscall_number = ecs->ws.value.syscall_number; |
| 3610 | stop_pc = regcache_read_pc (regcache); |
| 3611 | |
| 3612 | if (catch_syscall_enabled () > 0 |
| 3613 | && catching_syscall_number (syscall_number) > 0) |
| 3614 | { |
| 3615 | if (debug_infrun) |
| 3616 | fprintf_unfiltered (gdb_stdlog, "infrun: syscall number = '%d'\n", |
| 3617 | syscall_number); |
| 3618 | |
| 3619 | ecs->event_thread->control.stop_bpstat |
| 3620 | = bpstat_stop_status (get_regcache_aspace (regcache), |
| 3621 | stop_pc, ecs->ptid, &ecs->ws); |
| 3622 | |
| 3623 | if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat)) |
| 3624 | { |
| 3625 | /* Catchpoint hit. */ |
| 3626 | return 0; |
| 3627 | } |
| 3628 | } |
| 3629 | |
| 3630 | /* If no catchpoint triggered for this, then keep going. */ |
| 3631 | keep_going (ecs); |
| 3632 | return 1; |
| 3633 | } |
| 3634 | |
| 3635 | /* Lazily fill in the execution_control_state's stop_func_* fields. */ |
| 3636 | |
| 3637 | static void |
| 3638 | fill_in_stop_func (struct gdbarch *gdbarch, |
| 3639 | struct execution_control_state *ecs) |
| 3640 | { |
| 3641 | if (!ecs->stop_func_filled_in) |
| 3642 | { |
| 3643 | /* Don't care about return value; stop_func_start and stop_func_name |
| 3644 | will both be 0 if it doesn't work. */ |
| 3645 | find_pc_partial_function (stop_pc, &ecs->stop_func_name, |
| 3646 | &ecs->stop_func_start, &ecs->stop_func_end); |
| 3647 | ecs->stop_func_start |
| 3648 | += gdbarch_deprecated_function_start_offset (gdbarch); |
| 3649 | |
| 3650 | if (gdbarch_skip_entrypoint_p (gdbarch)) |
| 3651 | ecs->stop_func_start = gdbarch_skip_entrypoint (gdbarch, |
| 3652 | ecs->stop_func_start); |
| 3653 | |
| 3654 | ecs->stop_func_filled_in = 1; |
| 3655 | } |
| 3656 | } |
| 3657 | |
| 3658 | |
| 3659 | /* Return the STOP_SOON field of the inferior pointed at by PTID. */ |
| 3660 | |
| 3661 | static enum stop_kind |
| 3662 | get_inferior_stop_soon (ptid_t ptid) |
| 3663 | { |
| 3664 | struct inferior *inf = find_inferior_ptid (ptid); |
| 3665 | |
| 3666 | gdb_assert (inf != NULL); |
| 3667 | return inf->control.stop_soon; |
| 3668 | } |
| 3669 | |
| 3670 | /* Given an execution control state that has been freshly filled in by |
| 3671 | an event from the inferior, figure out what it means and take |
| 3672 | appropriate action. |
| 3673 | |
| 3674 | The alternatives are: |
| 3675 | |
| 3676 | 1) stop_waiting and return; to really stop and return to the |
| 3677 | debugger. |
| 3678 | |
| 3679 | 2) keep_going and return; to wait for the next event (set |
| 3680 | ecs->event_thread->stepping_over_breakpoint to 1 to single step |
| 3681 | once). */ |
| 3682 | |
| 3683 | static void |
| 3684 | handle_inferior_event_1 (struct execution_control_state *ecs) |
| 3685 | { |
| 3686 | enum stop_kind stop_soon; |
| 3687 | |
| 3688 | if (ecs->ws.kind == TARGET_WAITKIND_IGNORE) |
| 3689 | { |
| 3690 | /* We had an event in the inferior, but we are not interested in |
| 3691 | handling it at this level. The lower layers have already |
| 3692 | done what needs to be done, if anything. |
| 3693 | |
| 3694 | One of the possible circumstances for this is when the |
| 3695 | inferior produces output for the console. The inferior has |
| 3696 | not stopped, and we are ignoring the event. Another possible |
| 3697 | circumstance is any event which the lower level knows will be |
| 3698 | reported multiple times without an intervening resume. */ |
| 3699 | if (debug_infrun) |
| 3700 | fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_IGNORE\n"); |
| 3701 | prepare_to_wait (ecs); |
| 3702 | return; |
| 3703 | } |
| 3704 | |
| 3705 | if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED |
| 3706 | && target_can_async_p () && !sync_execution) |
| 3707 | { |
| 3708 | /* There were no unwaited-for children left in the target, but, |
| 3709 | we're not synchronously waiting for events either. Just |
| 3710 | ignore. Otherwise, if we were running a synchronous |
| 3711 | execution command, we need to cancel it and give the user |
| 3712 | back the terminal. */ |
| 3713 | if (debug_infrun) |
| 3714 | fprintf_unfiltered (gdb_stdlog, |
| 3715 | "infrun: TARGET_WAITKIND_NO_RESUMED (ignoring)\n"); |
| 3716 | prepare_to_wait (ecs); |
| 3717 | return; |
| 3718 | } |
| 3719 | |
| 3720 | /* Cache the last pid/waitstatus. */ |
| 3721 | set_last_target_status (ecs->ptid, ecs->ws); |
| 3722 | |
| 3723 | /* Always clear state belonging to the previous time we stopped. */ |
| 3724 | stop_stack_dummy = STOP_NONE; |
| 3725 | |
| 3726 | if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED) |
| 3727 | { |
| 3728 | /* No unwaited-for children left. IOW, all resumed children |
| 3729 | have exited. */ |
| 3730 | if (debug_infrun) |
| 3731 | fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_RESUMED\n"); |
| 3732 | |
| 3733 | stop_print_frame = 0; |
| 3734 | stop_waiting (ecs); |
| 3735 | return; |
| 3736 | } |
| 3737 | |
| 3738 | if (ecs->ws.kind != TARGET_WAITKIND_EXITED |
| 3739 | && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED) |
| 3740 | { |
| 3741 | ecs->event_thread = find_thread_ptid (ecs->ptid); |
| 3742 | /* If it's a new thread, add it to the thread database. */ |
| 3743 | if (ecs->event_thread == NULL) |
| 3744 | ecs->event_thread = add_thread (ecs->ptid); |
| 3745 | |
| 3746 | /* Disable range stepping. If the next step request could use a |
| 3747 | range, this will be end up re-enabled then. */ |
| 3748 | ecs->event_thread->control.may_range_step = 0; |
| 3749 | } |
| 3750 | |
| 3751 | /* Dependent on valid ECS->EVENT_THREAD. */ |
| 3752 | adjust_pc_after_break (ecs); |
| 3753 | |
| 3754 | /* Dependent on the current PC value modified by adjust_pc_after_break. */ |
| 3755 | reinit_frame_cache (); |
| 3756 | |
| 3757 | breakpoint_retire_moribund (); |
| 3758 | |
| 3759 | /* First, distinguish signals caused by the debugger from signals |
| 3760 | that have to do with the program's own actions. Note that |
| 3761 | breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending |
| 3762 | on the operating system version. Here we detect when a SIGILL or |
| 3763 | SIGEMT is really a breakpoint and change it to SIGTRAP. We do |
| 3764 | something similar for SIGSEGV, since a SIGSEGV will be generated |
| 3765 | when we're trying to execute a breakpoint instruction on a |
| 3766 | non-executable stack. This happens for call dummy breakpoints |
| 3767 | for architectures like SPARC that place call dummies on the |
| 3768 | stack. */ |
| 3769 | if (ecs->ws.kind == TARGET_WAITKIND_STOPPED |
| 3770 | && (ecs->ws.value.sig == GDB_SIGNAL_ILL |
| 3771 | || ecs->ws.value.sig == GDB_SIGNAL_SEGV |
| 3772 | || ecs->ws.value.sig == GDB_SIGNAL_EMT)) |
| 3773 | { |
| 3774 | struct regcache *regcache = get_thread_regcache (ecs->ptid); |
| 3775 | |
| 3776 | if (breakpoint_inserted_here_p (get_regcache_aspace (regcache), |
| 3777 | regcache_read_pc (regcache))) |
| 3778 | { |
| 3779 | if (debug_infrun) |
| 3780 | fprintf_unfiltered (gdb_stdlog, |
| 3781 | "infrun: Treating signal as SIGTRAP\n"); |
| 3782 | ecs->ws.value.sig = GDB_SIGNAL_TRAP; |
| 3783 | } |
| 3784 | } |
| 3785 | |
| 3786 | /* Mark the non-executing threads accordingly. In all-stop, all |
| 3787 | threads of all processes are stopped when we get any event |
| 3788 | reported. In non-stop mode, only the event thread stops. If |
| 3789 | we're handling a process exit in non-stop mode, there's nothing |
| 3790 | to do, as threads of the dead process are gone, and threads of |
| 3791 | any other process were left running. */ |
| 3792 | if (!non_stop) |
| 3793 | set_executing (minus_one_ptid, 0); |
| 3794 | else if (ecs->ws.kind != TARGET_WAITKIND_SIGNALLED |
| 3795 | && ecs->ws.kind != TARGET_WAITKIND_EXITED) |
| 3796 | set_executing (ecs->ptid, 0); |
| 3797 | |
| 3798 | switch (ecs->ws.kind) |
| 3799 | { |
| 3800 | case TARGET_WAITKIND_LOADED: |
| 3801 | if (debug_infrun) |
| 3802 | fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_LOADED\n"); |
| 3803 | if (!ptid_equal (ecs->ptid, inferior_ptid)) |
| 3804 | context_switch (ecs->ptid); |
| 3805 | /* Ignore gracefully during startup of the inferior, as it might |
| 3806 | be the shell which has just loaded some objects, otherwise |
| 3807 | add the symbols for the newly loaded objects. Also ignore at |
| 3808 | the beginning of an attach or remote session; we will query |
| 3809 | the full list of libraries once the connection is |
| 3810 | established. */ |
| 3811 | |
| 3812 | stop_soon = get_inferior_stop_soon (ecs->ptid); |
| 3813 | if (stop_soon == NO_STOP_QUIETLY) |
| 3814 | { |
| 3815 | struct regcache *regcache; |
| 3816 | |
| 3817 | regcache = get_thread_regcache (ecs->ptid); |
| 3818 | |
| 3819 | handle_solib_event (); |
| 3820 | |
| 3821 | ecs->event_thread->control.stop_bpstat |
| 3822 | = bpstat_stop_status (get_regcache_aspace (regcache), |
| 3823 | stop_pc, ecs->ptid, &ecs->ws); |
| 3824 | |
| 3825 | if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat)) |
| 3826 | { |
| 3827 | /* A catchpoint triggered. */ |
| 3828 | process_event_stop_test (ecs); |
| 3829 | return; |
| 3830 | } |
| 3831 | |
| 3832 | /* If requested, stop when the dynamic linker notifies |
| 3833 | gdb of events. This allows the user to get control |
| 3834 | and place breakpoints in initializer routines for |
| 3835 | dynamically loaded objects (among other things). */ |
| 3836 | ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0; |
| 3837 | if (stop_on_solib_events) |
| 3838 | { |
| 3839 | /* Make sure we print "Stopped due to solib-event" in |
| 3840 | normal_stop. */ |
| 3841 | stop_print_frame = 1; |
| 3842 | |
| 3843 | stop_waiting (ecs); |
| 3844 | return; |
| 3845 | } |
| 3846 | } |
| 3847 | |
| 3848 | /* If we are skipping through a shell, or through shared library |
| 3849 | loading that we aren't interested in, resume the program. If |
| 3850 | we're running the program normally, also resume. */ |
| 3851 | if (stop_soon == STOP_QUIETLY || stop_soon == NO_STOP_QUIETLY) |
| 3852 | { |
| 3853 | /* Loading of shared libraries might have changed breakpoint |
| 3854 | addresses. Make sure new breakpoints are inserted. */ |
| 3855 | if (stop_soon == NO_STOP_QUIETLY) |
| 3856 | insert_breakpoints (); |
| 3857 | resume (GDB_SIGNAL_0); |
| 3858 | prepare_to_wait (ecs); |
| 3859 | return; |
| 3860 | } |
| 3861 | |
| 3862 | /* But stop if we're attaching or setting up a remote |
| 3863 | connection. */ |
| 3864 | if (stop_soon == STOP_QUIETLY_NO_SIGSTOP |
| 3865 | || stop_soon == STOP_QUIETLY_REMOTE) |
| 3866 | { |
| 3867 | if (debug_infrun) |
| 3868 | fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n"); |
| 3869 | stop_waiting (ecs); |
| 3870 | return; |
| 3871 | } |
| 3872 | |
| 3873 | internal_error (__FILE__, __LINE__, |
| 3874 | _("unhandled stop_soon: %d"), (int) stop_soon); |
| 3875 | |
| 3876 | case TARGET_WAITKIND_SPURIOUS: |
| 3877 | if (debug_infrun) |
| 3878 | fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SPURIOUS\n"); |
| 3879 | if (!ptid_equal (ecs->ptid, inferior_ptid)) |
| 3880 | context_switch (ecs->ptid); |
| 3881 | resume (GDB_SIGNAL_0); |
| 3882 | prepare_to_wait (ecs); |
| 3883 | return; |
| 3884 | |
| 3885 | case TARGET_WAITKIND_EXITED: |
| 3886 | case TARGET_WAITKIND_SIGNALLED: |
| 3887 | if (debug_infrun) |
| 3888 | { |
| 3889 | if (ecs->ws.kind == TARGET_WAITKIND_EXITED) |
| 3890 | fprintf_unfiltered (gdb_stdlog, |
| 3891 | "infrun: TARGET_WAITKIND_EXITED\n"); |
| 3892 | else |
| 3893 | fprintf_unfiltered (gdb_stdlog, |
| 3894 | "infrun: TARGET_WAITKIND_SIGNALLED\n"); |
| 3895 | } |
| 3896 | |
| 3897 | inferior_ptid = ecs->ptid; |
| 3898 | set_current_inferior (find_inferior_ptid (ecs->ptid)); |
| 3899 | set_current_program_space (current_inferior ()->pspace); |
| 3900 | handle_vfork_child_exec_or_exit (0); |
| 3901 | target_terminal_ours (); /* Must do this before mourn anyway. */ |
| 3902 | |
| 3903 | /* Clearing any previous state of convenience variables. */ |
| 3904 | clear_exit_convenience_vars (); |
| 3905 | |
| 3906 | if (ecs->ws.kind == TARGET_WAITKIND_EXITED) |
| 3907 | { |
| 3908 | /* Record the exit code in the convenience variable $_exitcode, so |
| 3909 | that the user can inspect this again later. */ |
| 3910 | set_internalvar_integer (lookup_internalvar ("_exitcode"), |
| 3911 | (LONGEST) ecs->ws.value.integer); |
| 3912 | |
| 3913 | /* Also record this in the inferior itself. */ |
| 3914 | current_inferior ()->has_exit_code = 1; |
| 3915 | current_inferior ()->exit_code = (LONGEST) ecs->ws.value.integer; |
| 3916 | |
| 3917 | /* Support the --return-child-result option. */ |
| 3918 | return_child_result_value = ecs->ws.value.integer; |
| 3919 | |
| 3920 | observer_notify_exited (ecs->ws.value.integer); |
| 3921 | } |
| 3922 | else |
| 3923 | { |
| 3924 | struct regcache *regcache = get_thread_regcache (ecs->ptid); |
| 3925 | struct gdbarch *gdbarch = get_regcache_arch (regcache); |
| 3926 | |
| 3927 | if (gdbarch_gdb_signal_to_target_p (gdbarch)) |
| 3928 | { |
| 3929 | /* Set the value of the internal variable $_exitsignal, |
| 3930 | which holds the signal uncaught by the inferior. */ |
| 3931 | set_internalvar_integer (lookup_internalvar ("_exitsignal"), |
| 3932 | gdbarch_gdb_signal_to_target (gdbarch, |
| 3933 | ecs->ws.value.sig)); |
| 3934 | } |
| 3935 | else |
| 3936 | { |
| 3937 | /* We don't have access to the target's method used for |
| 3938 | converting between signal numbers (GDB's internal |
| 3939 | representation <-> target's representation). |
| 3940 | Therefore, we cannot do a good job at displaying this |
| 3941 | information to the user. It's better to just warn |
| 3942 | her about it (if infrun debugging is enabled), and |
| 3943 | give up. */ |
| 3944 | if (debug_infrun) |
| 3945 | fprintf_filtered (gdb_stdlog, _("\ |
| 3946 | Cannot fill $_exitsignal with the correct signal number.\n")); |
| 3947 | } |
| 3948 | |
| 3949 | observer_notify_signal_exited (ecs->ws.value.sig); |
| 3950 | } |
| 3951 | |
| 3952 | gdb_flush (gdb_stdout); |
| 3953 | target_mourn_inferior (); |
| 3954 | stop_print_frame = 0; |
| 3955 | stop_waiting (ecs); |
| 3956 | return; |
| 3957 | |
| 3958 | /* The following are the only cases in which we keep going; |
| 3959 | the above cases end in a continue or goto. */ |
| 3960 | case TARGET_WAITKIND_FORKED: |
| 3961 | case TARGET_WAITKIND_VFORKED: |
| 3962 | if (debug_infrun) |
| 3963 | { |
| 3964 | if (ecs->ws.kind == TARGET_WAITKIND_FORKED) |
| 3965 | fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_FORKED\n"); |
| 3966 | else |
| 3967 | fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_VFORKED\n"); |
| 3968 | } |
| 3969 | |
| 3970 | /* Check whether the inferior is displaced stepping. */ |
| 3971 | { |
| 3972 | struct regcache *regcache = get_thread_regcache (ecs->ptid); |
| 3973 | struct gdbarch *gdbarch = get_regcache_arch (regcache); |
| 3974 | struct displaced_step_inferior_state *displaced |
| 3975 | = get_displaced_stepping_state (ptid_get_pid (ecs->ptid)); |
| 3976 | |
| 3977 | /* If checking displaced stepping is supported, and thread |
| 3978 | ecs->ptid is displaced stepping. */ |
| 3979 | if (displaced && ptid_equal (displaced->step_ptid, ecs->ptid)) |
| 3980 | { |
| 3981 | struct inferior *parent_inf |
| 3982 | = find_inferior_ptid (ecs->ptid); |
| 3983 | struct regcache *child_regcache; |
| 3984 | CORE_ADDR parent_pc; |
| 3985 | |
| 3986 | /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED, |
| 3987 | indicating that the displaced stepping of syscall instruction |
| 3988 | has been done. Perform cleanup for parent process here. Note |
| 3989 | that this operation also cleans up the child process for vfork, |
| 3990 | because their pages are shared. */ |
| 3991 | displaced_step_fixup (ecs->ptid, GDB_SIGNAL_TRAP); |
| 3992 | |
| 3993 | if (ecs->ws.kind == TARGET_WAITKIND_FORKED) |
| 3994 | { |
| 3995 | /* Restore scratch pad for child process. */ |
| 3996 | displaced_step_restore (displaced, ecs->ws.value.related_pid); |
| 3997 | } |
| 3998 | |
| 3999 | /* Since the vfork/fork syscall instruction was executed in the scratchpad, |
| 4000 | the child's PC is also within the scratchpad. Set the child's PC |
| 4001 | to the parent's PC value, which has already been fixed up. |
| 4002 | FIXME: we use the parent's aspace here, although we're touching |
| 4003 | the child, because the child hasn't been added to the inferior |
| 4004 | list yet at this point. */ |
| 4005 | |
| 4006 | child_regcache |
| 4007 | = get_thread_arch_aspace_regcache (ecs->ws.value.related_pid, |
| 4008 | gdbarch, |
| 4009 | parent_inf->aspace); |
| 4010 | /* Read PC value of parent process. */ |
| 4011 | parent_pc = regcache_read_pc (regcache); |
| 4012 | |
| 4013 | if (debug_displaced) |
| 4014 | fprintf_unfiltered (gdb_stdlog, |
| 4015 | "displaced: write child pc from %s to %s\n", |
| 4016 | paddress (gdbarch, |
| 4017 | regcache_read_pc (child_regcache)), |
| 4018 | paddress (gdbarch, parent_pc)); |
| 4019 | |
| 4020 | regcache_write_pc (child_regcache, parent_pc); |
| 4021 | } |
| 4022 | } |
| 4023 | |
| 4024 | if (!ptid_equal (ecs->ptid, inferior_ptid)) |
| 4025 | context_switch (ecs->ptid); |
| 4026 | |
| 4027 | /* Immediately detach breakpoints from the child before there's |
| 4028 | any chance of letting the user delete breakpoints from the |
| 4029 | breakpoint lists. If we don't do this early, it's easy to |
| 4030 | leave left over traps in the child, vis: "break foo; catch |
| 4031 | fork; c; <fork>; del; c; <child calls foo>". We only follow |
| 4032 | the fork on the last `continue', and by that time the |
| 4033 | breakpoint at "foo" is long gone from the breakpoint table. |
| 4034 | If we vforked, then we don't need to unpatch here, since both |
| 4035 | parent and child are sharing the same memory pages; we'll |
| 4036 | need to unpatch at follow/detach time instead to be certain |
| 4037 | that new breakpoints added between catchpoint hit time and |
| 4038 | vfork follow are detached. */ |
| 4039 | if (ecs->ws.kind != TARGET_WAITKIND_VFORKED) |
| 4040 | { |
| 4041 | /* This won't actually modify the breakpoint list, but will |
| 4042 | physically remove the breakpoints from the child. */ |
| 4043 | detach_breakpoints (ecs->ws.value.related_pid); |
| 4044 | } |
| 4045 | |
| 4046 | delete_just_stopped_threads_single_step_breakpoints (); |
| 4047 | |
| 4048 | /* In case the event is caught by a catchpoint, remember that |
| 4049 | the event is to be followed at the next resume of the thread, |
| 4050 | and not immediately. */ |
| 4051 | ecs->event_thread->pending_follow = ecs->ws; |
| 4052 | |
| 4053 | stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid)); |
| 4054 | |
| 4055 | ecs->event_thread->control.stop_bpstat |
| 4056 | = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()), |
| 4057 | stop_pc, ecs->ptid, &ecs->ws); |
| 4058 | |
| 4059 | /* If no catchpoint triggered for this, then keep going. Note |
| 4060 | that we're interested in knowing the bpstat actually causes a |
| 4061 | stop, not just if it may explain the signal. Software |
| 4062 | watchpoints, for example, always appear in the bpstat. */ |
| 4063 | if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat)) |
| 4064 | { |
| 4065 | ptid_t parent; |
| 4066 | ptid_t child; |
| 4067 | int should_resume; |
| 4068 | int follow_child |
| 4069 | = (follow_fork_mode_string == follow_fork_mode_child); |
| 4070 | |
| 4071 | ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0; |
| 4072 | |
| 4073 | should_resume = follow_fork (); |
| 4074 | |
| 4075 | parent = ecs->ptid; |
| 4076 | child = ecs->ws.value.related_pid; |
| 4077 | |
| 4078 | /* In non-stop mode, also resume the other branch. */ |
| 4079 | if (non_stop && !detach_fork) |
| 4080 | { |
| 4081 | if (follow_child) |
| 4082 | switch_to_thread (parent); |
| 4083 | else |
| 4084 | switch_to_thread (child); |
| 4085 | |
| 4086 | ecs->event_thread = inferior_thread (); |
| 4087 | ecs->ptid = inferior_ptid; |
| 4088 | keep_going (ecs); |
| 4089 | } |
| 4090 | |
| 4091 | if (follow_child) |
| 4092 | switch_to_thread (child); |
| 4093 | else |
| 4094 | switch_to_thread (parent); |
| 4095 | |
| 4096 | ecs->event_thread = inferior_thread (); |
| 4097 | ecs->ptid = inferior_ptid; |
| 4098 | |
| 4099 | if (should_resume) |
| 4100 | keep_going (ecs); |
| 4101 | else |
| 4102 | stop_waiting (ecs); |
| 4103 | return; |
| 4104 | } |
| 4105 | process_event_stop_test (ecs); |
| 4106 | return; |
| 4107 | |
| 4108 | case TARGET_WAITKIND_VFORK_DONE: |
| 4109 | /* Done with the shared memory region. Re-insert breakpoints in |
| 4110 | the parent, and keep going. */ |
| 4111 | |
| 4112 | if (debug_infrun) |
| 4113 | fprintf_unfiltered (gdb_stdlog, |
| 4114 | "infrun: TARGET_WAITKIND_VFORK_DONE\n"); |
| 4115 | |
| 4116 | if (!ptid_equal (ecs->ptid, inferior_ptid)) |
| 4117 | context_switch (ecs->ptid); |
| 4118 | |
| 4119 | current_inferior ()->waiting_for_vfork_done = 0; |
| 4120 | current_inferior ()->pspace->breakpoints_not_allowed = 0; |
| 4121 | /* This also takes care of reinserting breakpoints in the |
| 4122 | previously locked inferior. */ |
| 4123 | keep_going (ecs); |
| 4124 | return; |
| 4125 | |
| 4126 | case TARGET_WAITKIND_EXECD: |
| 4127 | if (debug_infrun) |
| 4128 | fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_EXECD\n"); |
| 4129 | |
| 4130 | if (!ptid_equal (ecs->ptid, inferior_ptid)) |
| 4131 | context_switch (ecs->ptid); |
| 4132 | |
| 4133 | stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid)); |
| 4134 | |
| 4135 | /* Do whatever is necessary to the parent branch of the vfork. */ |
| 4136 | handle_vfork_child_exec_or_exit (1); |
| 4137 | |
| 4138 | /* This causes the eventpoints and symbol table to be reset. |
| 4139 | Must do this now, before trying to determine whether to |
| 4140 | stop. */ |
| 4141 | follow_exec (inferior_ptid, ecs->ws.value.execd_pathname); |
| 4142 | |
| 4143 | ecs->event_thread->control.stop_bpstat |
| 4144 | = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()), |
| 4145 | stop_pc, ecs->ptid, &ecs->ws); |
| 4146 | |
| 4147 | /* Note that this may be referenced from inside |
| 4148 | bpstat_stop_status above, through inferior_has_execd. */ |
| 4149 | xfree (ecs->ws.value.execd_pathname); |
| 4150 | ecs->ws.value.execd_pathname = NULL; |
| 4151 | |
| 4152 | /* If no catchpoint triggered for this, then keep going. */ |
| 4153 | if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat)) |
| 4154 | { |
| 4155 | ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0; |
| 4156 | keep_going (ecs); |
| 4157 | return; |
| 4158 | } |
| 4159 | process_event_stop_test (ecs); |
| 4160 | return; |
| 4161 | |
| 4162 | /* Be careful not to try to gather much state about a thread |
| 4163 | that's in a syscall. It's frequently a losing proposition. */ |
| 4164 | case TARGET_WAITKIND_SYSCALL_ENTRY: |
| 4165 | if (debug_infrun) |
| 4166 | fprintf_unfiltered (gdb_stdlog, |
| 4167 | "infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n"); |
| 4168 | /* Getting the current syscall number. */ |
| 4169 | if (handle_syscall_event (ecs) == 0) |
| 4170 | process_event_stop_test (ecs); |
| 4171 | return; |
| 4172 | |
| 4173 | /* Before examining the threads further, step this thread to |
| 4174 | get it entirely out of the syscall. (We get notice of the |
| 4175 | event when the thread is just on the verge of exiting a |
| 4176 | syscall. Stepping one instruction seems to get it back |
| 4177 | into user code.) */ |
| 4178 | case TARGET_WAITKIND_SYSCALL_RETURN: |
| 4179 | if (debug_infrun) |
| 4180 | fprintf_unfiltered (gdb_stdlog, |
| 4181 | "infrun: TARGET_WAITKIND_SYSCALL_RETURN\n"); |
| 4182 | if (handle_syscall_event (ecs) == 0) |
| 4183 | process_event_stop_test (ecs); |
| 4184 | return; |
| 4185 | |
| 4186 | case TARGET_WAITKIND_STOPPED: |
| 4187 | if (debug_infrun) |
| 4188 | fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_STOPPED\n"); |
| 4189 | ecs->event_thread->suspend.stop_signal = ecs->ws.value.sig; |
| 4190 | handle_signal_stop (ecs); |
| 4191 | return; |
| 4192 | |
| 4193 | case TARGET_WAITKIND_NO_HISTORY: |
| 4194 | if (debug_infrun) |
| 4195 | fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_HISTORY\n"); |
| 4196 | /* Reverse execution: target ran out of history info. */ |
| 4197 | |
| 4198 | delete_just_stopped_threads_single_step_breakpoints (); |
| 4199 | stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid)); |
| 4200 | observer_notify_no_history (); |
| 4201 | stop_waiting (ecs); |
| 4202 | return; |
| 4203 | } |
| 4204 | } |
| 4205 | |
| 4206 | /* A wrapper around handle_inferior_event_1, which also makes sure |
| 4207 | that all temporary struct value objects that were created during |
| 4208 | the handling of the event get deleted at the end. */ |
| 4209 | |
| 4210 | static void |
| 4211 | handle_inferior_event (struct execution_control_state *ecs) |
| 4212 | { |
| 4213 | struct value *mark = value_mark (); |
| 4214 | |
| 4215 | handle_inferior_event_1 (ecs); |
| 4216 | /* Purge all temporary values created during the event handling, |
| 4217 | as it could be a long time before we return to the command level |
| 4218 | where such values would otherwise be purged. */ |
| 4219 | value_free_to_mark (mark); |
| 4220 | } |
| 4221 | |
| 4222 | /* Come here when the program has stopped with a signal. */ |
| 4223 | |
| 4224 | static void |
| 4225 | handle_signal_stop (struct execution_control_state *ecs) |
| 4226 | { |
| 4227 | struct frame_info *frame; |
| 4228 | struct gdbarch *gdbarch; |
| 4229 | int stopped_by_watchpoint; |
| 4230 | enum stop_kind stop_soon; |
| 4231 | int random_signal; |
| 4232 | |
| 4233 | gdb_assert (ecs->ws.kind == TARGET_WAITKIND_STOPPED); |
| 4234 | |
| 4235 | /* Do we need to clean up the state of a thread that has |
| 4236 | completed a displaced single-step? (Doing so usually affects |
| 4237 | the PC, so do it here, before we set stop_pc.) */ |
| 4238 | displaced_step_fixup (ecs->ptid, |
| 4239 | ecs->event_thread->suspend.stop_signal); |
| 4240 | |
| 4241 | /* If we either finished a single-step or hit a breakpoint, but |
| 4242 | the user wanted this thread to be stopped, pretend we got a |
| 4243 | SIG0 (generic unsignaled stop). */ |
| 4244 | if (ecs->event_thread->stop_requested |
| 4245 | && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP) |
| 4246 | ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0; |
| 4247 | |
| 4248 | stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid)); |
| 4249 | |
| 4250 | if (debug_infrun) |
| 4251 | { |
| 4252 | struct regcache *regcache = get_thread_regcache (ecs->ptid); |
| 4253 | struct gdbarch *gdbarch = get_regcache_arch (regcache); |
| 4254 | struct cleanup *old_chain = save_inferior_ptid (); |
| 4255 | |
| 4256 | inferior_ptid = ecs->ptid; |
| 4257 | |
| 4258 | fprintf_unfiltered (gdb_stdlog, "infrun: stop_pc = %s\n", |
| 4259 | paddress (gdbarch, stop_pc)); |
| 4260 | if (target_stopped_by_watchpoint ()) |
| 4261 | { |
| 4262 | CORE_ADDR addr; |
| 4263 | |
| 4264 | fprintf_unfiltered (gdb_stdlog, "infrun: stopped by watchpoint\n"); |
| 4265 | |
| 4266 | if (target_stopped_data_address (¤t_target, &addr)) |
| 4267 | fprintf_unfiltered (gdb_stdlog, |
| 4268 | "infrun: stopped data address = %s\n", |
| 4269 | paddress (gdbarch, addr)); |
| 4270 | else |
| 4271 | fprintf_unfiltered (gdb_stdlog, |
| 4272 | "infrun: (no data address available)\n"); |
| 4273 | } |
| 4274 | |
| 4275 | do_cleanups (old_chain); |
| 4276 | } |
| 4277 | |
| 4278 | /* This is originated from start_remote(), start_inferior() and |
| 4279 | shared libraries hook functions. */ |
| 4280 | stop_soon = get_inferior_stop_soon (ecs->ptid); |
| 4281 | if (stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_REMOTE) |
| 4282 | { |
| 4283 | if (!ptid_equal (ecs->ptid, inferior_ptid)) |
| 4284 | context_switch (ecs->ptid); |
| 4285 | if (debug_infrun) |
| 4286 | fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n"); |
| 4287 | stop_print_frame = 1; |
| 4288 | stop_waiting (ecs); |
| 4289 | return; |
| 4290 | } |
| 4291 | |
| 4292 | if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP |
| 4293 | && stop_after_trap) |
| 4294 | { |
| 4295 | if (!ptid_equal (ecs->ptid, inferior_ptid)) |
| 4296 | context_switch (ecs->ptid); |
| 4297 | if (debug_infrun) |
| 4298 | fprintf_unfiltered (gdb_stdlog, "infrun: stopped\n"); |
| 4299 | stop_print_frame = 0; |
| 4300 | stop_waiting (ecs); |
| 4301 | return; |
| 4302 | } |
| 4303 | |
| 4304 | /* This originates from attach_command(). We need to overwrite |
| 4305 | the stop_signal here, because some kernels don't ignore a |
| 4306 | SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call. |
| 4307 | See more comments in inferior.h. On the other hand, if we |
| 4308 | get a non-SIGSTOP, report it to the user - assume the backend |
| 4309 | will handle the SIGSTOP if it should show up later. |
| 4310 | |
| 4311 | Also consider that the attach is complete when we see a |
| 4312 | SIGTRAP. Some systems (e.g. Windows), and stubs supporting |
| 4313 | target extended-remote report it instead of a SIGSTOP |
| 4314 | (e.g. gdbserver). We already rely on SIGTRAP being our |
| 4315 | signal, so this is no exception. |
| 4316 | |
| 4317 | Also consider that the attach is complete when we see a |
| 4318 | GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell |
| 4319 | the target to stop all threads of the inferior, in case the |
| 4320 | low level attach operation doesn't stop them implicitly. If |
| 4321 | they weren't stopped implicitly, then the stub will report a |
| 4322 | GDB_SIGNAL_0, meaning: stopped for no particular reason |
| 4323 | other than GDB's request. */ |
| 4324 | if (stop_soon == STOP_QUIETLY_NO_SIGSTOP |
| 4325 | && (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_STOP |
| 4326 | || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP |
| 4327 | || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_0)) |
| 4328 | { |
| 4329 | stop_print_frame = 1; |
| 4330 | stop_waiting (ecs); |
| 4331 | ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0; |
| 4332 | return; |
| 4333 | } |
| 4334 | |
| 4335 | /* See if something interesting happened to the non-current thread. If |
| 4336 | so, then switch to that thread. */ |
| 4337 | if (!ptid_equal (ecs->ptid, inferior_ptid)) |
| 4338 | { |
| 4339 | if (debug_infrun) |
| 4340 | fprintf_unfiltered (gdb_stdlog, "infrun: context switch\n"); |
| 4341 | |
| 4342 | context_switch (ecs->ptid); |
| 4343 | |
| 4344 | if (deprecated_context_hook) |
| 4345 | deprecated_context_hook (pid_to_thread_id (ecs->ptid)); |
| 4346 | } |
| 4347 | |
| 4348 | /* At this point, get hold of the now-current thread's frame. */ |
| 4349 | frame = get_current_frame (); |
| 4350 | gdbarch = get_frame_arch (frame); |
| 4351 | |
| 4352 | /* Pull the single step breakpoints out of the target. */ |
| 4353 | if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP) |
| 4354 | { |
| 4355 | struct regcache *regcache; |
| 4356 | struct address_space *aspace; |
| 4357 | CORE_ADDR pc; |
| 4358 | |
| 4359 | regcache = get_thread_regcache (ecs->ptid); |
| 4360 | aspace = get_regcache_aspace (regcache); |
| 4361 | pc = regcache_read_pc (regcache); |
| 4362 | |
| 4363 | /* However, before doing so, if this single-step breakpoint was |
| 4364 | actually for another thread, set this thread up for moving |
| 4365 | past it. */ |
| 4366 | if (!thread_has_single_step_breakpoint_here (ecs->event_thread, |
| 4367 | aspace, pc)) |
| 4368 | { |
| 4369 | if (single_step_breakpoint_inserted_here_p (aspace, pc)) |
| 4370 | { |
| 4371 | if (debug_infrun) |
| 4372 | { |
| 4373 | fprintf_unfiltered (gdb_stdlog, |
| 4374 | "infrun: [%s] hit another thread's " |
| 4375 | "single-step breakpoint\n", |
| 4376 | target_pid_to_str (ecs->ptid)); |
| 4377 | } |
| 4378 | ecs->hit_singlestep_breakpoint = 1; |
| 4379 | } |
| 4380 | } |
| 4381 | else |
| 4382 | { |
| 4383 | if (debug_infrun) |
| 4384 | { |
| 4385 | fprintf_unfiltered (gdb_stdlog, |
| 4386 | "infrun: [%s] hit its " |
| 4387 | "single-step breakpoint\n", |
| 4388 | target_pid_to_str (ecs->ptid)); |
| 4389 | } |
| 4390 | } |
| 4391 | } |
| 4392 | delete_just_stopped_threads_single_step_breakpoints (); |
| 4393 | |
| 4394 | if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP |
| 4395 | && ecs->event_thread->control.trap_expected |
| 4396 | && ecs->event_thread->stepping_over_watchpoint) |
| 4397 | stopped_by_watchpoint = 0; |
| 4398 | else |
| 4399 | stopped_by_watchpoint = watchpoints_triggered (&ecs->ws); |
| 4400 | |
| 4401 | /* If necessary, step over this watchpoint. We'll be back to display |
| 4402 | it in a moment. */ |
| 4403 | if (stopped_by_watchpoint |
| 4404 | && (target_have_steppable_watchpoint |
| 4405 | || gdbarch_have_nonsteppable_watchpoint (gdbarch))) |
| 4406 | { |
| 4407 | /* At this point, we are stopped at an instruction which has |
| 4408 | attempted to write to a piece of memory under control of |
| 4409 | a watchpoint. The instruction hasn't actually executed |
| 4410 | yet. If we were to evaluate the watchpoint expression |
| 4411 | now, we would get the old value, and therefore no change |
| 4412 | would seem to have occurred. |
| 4413 | |
| 4414 | In order to make watchpoints work `right', we really need |
| 4415 | to complete the memory write, and then evaluate the |
| 4416 | watchpoint expression. We do this by single-stepping the |
| 4417 | target. |
| 4418 | |
| 4419 | It may not be necessary to disable the watchpoint to step over |
| 4420 | it. For example, the PA can (with some kernel cooperation) |
| 4421 | single step over a watchpoint without disabling the watchpoint. |
| 4422 | |
| 4423 | It is far more common to need to disable a watchpoint to step |
| 4424 | the inferior over it. If we have non-steppable watchpoints, |
| 4425 | we must disable the current watchpoint; it's simplest to |
| 4426 | disable all watchpoints. |
| 4427 | |
| 4428 | Any breakpoint at PC must also be stepped over -- if there's |
| 4429 | one, it will have already triggered before the watchpoint |
| 4430 | triggered, and we either already reported it to the user, or |
| 4431 | it didn't cause a stop and we called keep_going. In either |
| 4432 | case, if there was a breakpoint at PC, we must be trying to |
| 4433 | step past it. */ |
| 4434 | ecs->event_thread->stepping_over_watchpoint = 1; |
| 4435 | keep_going (ecs); |
| 4436 | return; |
| 4437 | } |
| 4438 | |
| 4439 | ecs->event_thread->stepping_over_breakpoint = 0; |
| 4440 | ecs->event_thread->stepping_over_watchpoint = 0; |
| 4441 | bpstat_clear (&ecs->event_thread->control.stop_bpstat); |
| 4442 | ecs->event_thread->control.stop_step = 0; |
| 4443 | stop_print_frame = 1; |
| 4444 | stopped_by_random_signal = 0; |
| 4445 | |
| 4446 | /* Hide inlined functions starting here, unless we just performed stepi or |
| 4447 | nexti. After stepi and nexti, always show the innermost frame (not any |
| 4448 | inline function call sites). */ |
| 4449 | if (ecs->event_thread->control.step_range_end != 1) |
| 4450 | { |
| 4451 | struct address_space *aspace = |
| 4452 | get_regcache_aspace (get_thread_regcache (ecs->ptid)); |
| 4453 | |
| 4454 | /* skip_inline_frames is expensive, so we avoid it if we can |
| 4455 | determine that the address is one where functions cannot have |
| 4456 | been inlined. This improves performance with inferiors that |
| 4457 | load a lot of shared libraries, because the solib event |
| 4458 | breakpoint is defined as the address of a function (i.e. not |
| 4459 | inline). Note that we have to check the previous PC as well |
| 4460 | as the current one to catch cases when we have just |
| 4461 | single-stepped off a breakpoint prior to reinstating it. |
| 4462 | Note that we're assuming that the code we single-step to is |
| 4463 | not inline, but that's not definitive: there's nothing |
| 4464 | preventing the event breakpoint function from containing |
| 4465 | inlined code, and the single-step ending up there. If the |
| 4466 | user had set a breakpoint on that inlined code, the missing |
| 4467 | skip_inline_frames call would break things. Fortunately |
| 4468 | that's an extremely unlikely scenario. */ |
| 4469 | if (!pc_at_non_inline_function (aspace, stop_pc, &ecs->ws) |
| 4470 | && !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP |
| 4471 | && ecs->event_thread->control.trap_expected |
| 4472 | && pc_at_non_inline_function (aspace, |
| 4473 | ecs->event_thread->prev_pc, |
| 4474 | &ecs->ws))) |
| 4475 | { |
| 4476 | skip_inline_frames (ecs->ptid); |
| 4477 | |
| 4478 | /* Re-fetch current thread's frame in case that invalidated |
| 4479 | the frame cache. */ |
| 4480 | frame = get_current_frame (); |
| 4481 | gdbarch = get_frame_arch (frame); |
| 4482 | } |
| 4483 | } |
| 4484 | |
| 4485 | if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP |
| 4486 | && ecs->event_thread->control.trap_expected |
| 4487 | && gdbarch_single_step_through_delay_p (gdbarch) |
| 4488 | && currently_stepping (ecs->event_thread)) |
| 4489 | { |
| 4490 | /* We're trying to step off a breakpoint. Turns out that we're |
| 4491 | also on an instruction that needs to be stepped multiple |
| 4492 | times before it's been fully executing. E.g., architectures |
| 4493 | with a delay slot. It needs to be stepped twice, once for |
| 4494 | the instruction and once for the delay slot. */ |
| 4495 | int step_through_delay |
| 4496 | = gdbarch_single_step_through_delay (gdbarch, frame); |
| 4497 | |
| 4498 | if (debug_infrun && step_through_delay) |
| 4499 | fprintf_unfiltered (gdb_stdlog, "infrun: step through delay\n"); |
| 4500 | if (ecs->event_thread->control.step_range_end == 0 |
| 4501 | && step_through_delay) |
| 4502 | { |
| 4503 | /* The user issued a continue when stopped at a breakpoint. |
| 4504 | Set up for another trap and get out of here. */ |
| 4505 | ecs->event_thread->stepping_over_breakpoint = 1; |
| 4506 | keep_going (ecs); |
| 4507 | return; |
| 4508 | } |
| 4509 | else if (step_through_delay) |
| 4510 | { |
| 4511 | /* The user issued a step when stopped at a breakpoint. |
| 4512 | Maybe we should stop, maybe we should not - the delay |
| 4513 | slot *might* correspond to a line of source. In any |
| 4514 | case, don't decide that here, just set |
| 4515 | ecs->stepping_over_breakpoint, making sure we |
| 4516 | single-step again before breakpoints are re-inserted. */ |
| 4517 | ecs->event_thread->stepping_over_breakpoint = 1; |
| 4518 | } |
| 4519 | } |
| 4520 | |
| 4521 | /* See if there is a breakpoint/watchpoint/catchpoint/etc. that |
| 4522 | handles this event. */ |
| 4523 | ecs->event_thread->control.stop_bpstat |
| 4524 | = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()), |
| 4525 | stop_pc, ecs->ptid, &ecs->ws); |
| 4526 | |
| 4527 | /* Following in case break condition called a |
| 4528 | function. */ |
| 4529 | stop_print_frame = 1; |
| 4530 | |
| 4531 | /* This is where we handle "moribund" watchpoints. Unlike |
| 4532 | software breakpoints traps, hardware watchpoint traps are |
| 4533 | always distinguishable from random traps. If no high-level |
| 4534 | watchpoint is associated with the reported stop data address |
| 4535 | anymore, then the bpstat does not explain the signal --- |
| 4536 | simply make sure to ignore it if `stopped_by_watchpoint' is |
| 4537 | set. */ |
| 4538 | |
| 4539 | if (debug_infrun |
| 4540 | && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP |
| 4541 | && !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat, |
| 4542 | GDB_SIGNAL_TRAP) |
| 4543 | && stopped_by_watchpoint) |
| 4544 | fprintf_unfiltered (gdb_stdlog, |
| 4545 | "infrun: no user watchpoint explains " |
| 4546 | "watchpoint SIGTRAP, ignoring\n"); |
| 4547 | |
| 4548 | /* NOTE: cagney/2003-03-29: These checks for a random signal |
| 4549 | at one stage in the past included checks for an inferior |
| 4550 | function call's call dummy's return breakpoint. The original |
| 4551 | comment, that went with the test, read: |
| 4552 | |
| 4553 | ``End of a stack dummy. Some systems (e.g. Sony news) give |
| 4554 | another signal besides SIGTRAP, so check here as well as |
| 4555 | above.'' |
| 4556 | |
| 4557 | If someone ever tries to get call dummys on a |
| 4558 | non-executable stack to work (where the target would stop |
| 4559 | with something like a SIGSEGV), then those tests might need |
| 4560 | to be re-instated. Given, however, that the tests were only |
| 4561 | enabled when momentary breakpoints were not being used, I |
| 4562 | suspect that it won't be the case. |
| 4563 | |
| 4564 | NOTE: kettenis/2004-02-05: Indeed such checks don't seem to |
| 4565 | be necessary for call dummies on a non-executable stack on |
| 4566 | SPARC. */ |
| 4567 | |
| 4568 | /* See if the breakpoints module can explain the signal. */ |
| 4569 | random_signal |
| 4570 | = !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat, |
| 4571 | ecs->event_thread->suspend.stop_signal); |
| 4572 | |
| 4573 | /* Maybe this was a trap for a software breakpoint that has since |
| 4574 | been removed. */ |
| 4575 | if (random_signal && target_stopped_by_sw_breakpoint ()) |
| 4576 | { |
| 4577 | if (program_breakpoint_here_p (gdbarch, stop_pc)) |
| 4578 | { |
| 4579 | struct regcache *regcache; |
| 4580 | int decr_pc; |
| 4581 | |
| 4582 | /* Re-adjust PC to what the program would see if GDB was not |
| 4583 | debugging it. */ |
| 4584 | regcache = get_thread_regcache (ecs->event_thread->ptid); |
| 4585 | decr_pc = gdbarch_decr_pc_after_break (gdbarch); |
| 4586 | if (decr_pc != 0) |
| 4587 | { |
| 4588 | struct cleanup *old_cleanups = make_cleanup (null_cleanup, NULL); |
| 4589 | |
| 4590 | if (record_full_is_used ()) |
| 4591 | record_full_gdb_operation_disable_set (); |
| 4592 | |
| 4593 | regcache_write_pc (regcache, stop_pc + decr_pc); |
| 4594 | |
| 4595 | do_cleanups (old_cleanups); |
| 4596 | } |
| 4597 | } |
| 4598 | else |
| 4599 | { |
| 4600 | /* A delayed software breakpoint event. Ignore the trap. */ |
| 4601 | if (debug_infrun) |
| 4602 | fprintf_unfiltered (gdb_stdlog, |
| 4603 | "infrun: delayed software breakpoint " |
| 4604 | "trap, ignoring\n"); |
| 4605 | random_signal = 0; |
| 4606 | } |
| 4607 | } |
| 4608 | |
| 4609 | /* Maybe this was a trap for a hardware breakpoint/watchpoint that |
| 4610 | has since been removed. */ |
| 4611 | if (random_signal && target_stopped_by_hw_breakpoint ()) |
| 4612 | { |
| 4613 | /* A delayed hardware breakpoint event. Ignore the trap. */ |
| 4614 | if (debug_infrun) |
| 4615 | fprintf_unfiltered (gdb_stdlog, |
| 4616 | "infrun: delayed hardware breakpoint/watchpoint " |
| 4617 | "trap, ignoring\n"); |
| 4618 | random_signal = 0; |
| 4619 | } |
| 4620 | |
| 4621 | /* If not, perhaps stepping/nexting can. */ |
| 4622 | if (random_signal) |
| 4623 | random_signal = !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP |
| 4624 | && currently_stepping (ecs->event_thread)); |
| 4625 | |
| 4626 | /* Perhaps the thread hit a single-step breakpoint of _another_ |
| 4627 | thread. Single-step breakpoints are transparent to the |
| 4628 | breakpoints module. */ |
| 4629 | if (random_signal) |
| 4630 | random_signal = !ecs->hit_singlestep_breakpoint; |
| 4631 | |
| 4632 | /* No? Perhaps we got a moribund watchpoint. */ |
| 4633 | if (random_signal) |
| 4634 | random_signal = !stopped_by_watchpoint; |
| 4635 | |
| 4636 | /* For the program's own signals, act according to |
| 4637 | the signal handling tables. */ |
| 4638 | |
| 4639 | if (random_signal) |
| 4640 | { |
| 4641 | /* Signal not for debugging purposes. */ |
| 4642 | struct inferior *inf = find_inferior_ptid (ecs->ptid); |
| 4643 | enum gdb_signal stop_signal = ecs->event_thread->suspend.stop_signal; |
| 4644 | |
| 4645 | if (debug_infrun) |
| 4646 | fprintf_unfiltered (gdb_stdlog, "infrun: random signal (%s)\n", |
| 4647 | gdb_signal_to_symbol_string (stop_signal)); |
| 4648 | |
| 4649 | stopped_by_random_signal = 1; |
| 4650 | |
| 4651 | /* Always stop on signals if we're either just gaining control |
| 4652 | of the program, or the user explicitly requested this thread |
| 4653 | to remain stopped. */ |
| 4654 | if (stop_soon != NO_STOP_QUIETLY |
| 4655 | || ecs->event_thread->stop_requested |
| 4656 | || (!inf->detaching |
| 4657 | && signal_stop_state (ecs->event_thread->suspend.stop_signal))) |
| 4658 | { |
| 4659 | stop_waiting (ecs); |
| 4660 | return; |
| 4661 | } |
| 4662 | |
| 4663 | /* Notify observers the signal has "handle print" set. Note we |
| 4664 | returned early above if stopping; normal_stop handles the |
| 4665 | printing in that case. */ |
| 4666 | if (signal_print[ecs->event_thread->suspend.stop_signal]) |
| 4667 | { |
| 4668 | /* The signal table tells us to print about this signal. */ |
| 4669 | target_terminal_ours_for_output (); |
| 4670 | observer_notify_signal_received (ecs->event_thread->suspend.stop_signal); |
| 4671 | target_terminal_inferior (); |
| 4672 | } |
| 4673 | |
| 4674 | /* Clear the signal if it should not be passed. */ |
| 4675 | if (signal_program[ecs->event_thread->suspend.stop_signal] == 0) |
| 4676 | ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0; |
| 4677 | |
| 4678 | if (ecs->event_thread->prev_pc == stop_pc |
| 4679 | && ecs->event_thread->control.trap_expected |
| 4680 | && ecs->event_thread->control.step_resume_breakpoint == NULL) |
| 4681 | { |
| 4682 | /* We were just starting a new sequence, attempting to |
| 4683 | single-step off of a breakpoint and expecting a SIGTRAP. |
| 4684 | Instead this signal arrives. This signal will take us out |
| 4685 | of the stepping range so GDB needs to remember to, when |
| 4686 | the signal handler returns, resume stepping off that |
| 4687 | breakpoint. */ |
| 4688 | /* To simplify things, "continue" is forced to use the same |
| 4689 | code paths as single-step - set a breakpoint at the |
| 4690 | signal return address and then, once hit, step off that |
| 4691 | breakpoint. */ |
| 4692 | if (debug_infrun) |
| 4693 | fprintf_unfiltered (gdb_stdlog, |
| 4694 | "infrun: signal arrived while stepping over " |
| 4695 | "breakpoint\n"); |
| 4696 | |
| 4697 | insert_hp_step_resume_breakpoint_at_frame (frame); |
| 4698 | ecs->event_thread->step_after_step_resume_breakpoint = 1; |
| 4699 | /* Reset trap_expected to ensure breakpoints are re-inserted. */ |
| 4700 | ecs->event_thread->control.trap_expected = 0; |
| 4701 | |
| 4702 | /* If we were nexting/stepping some other thread, switch to |
| 4703 | it, so that we don't continue it, losing control. */ |
| 4704 | if (!switch_back_to_stepped_thread (ecs)) |
| 4705 | keep_going (ecs); |
| 4706 | return; |
| 4707 | } |
| 4708 | |
| 4709 | if (ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_0 |
| 4710 | && (pc_in_thread_step_range (stop_pc, ecs->event_thread) |
| 4711 | || ecs->event_thread->control.step_range_end == 1) |
| 4712 | && frame_id_eq (get_stack_frame_id (frame), |
| 4713 | ecs->event_thread->control.step_stack_frame_id) |
| 4714 | && ecs->event_thread->control.step_resume_breakpoint == NULL) |
| 4715 | { |
| 4716 | /* The inferior is about to take a signal that will take it |
| 4717 | out of the single step range. Set a breakpoint at the |
| 4718 | current PC (which is presumably where the signal handler |
| 4719 | will eventually return) and then allow the inferior to |
| 4720 | run free. |
| 4721 | |
| 4722 | Note that this is only needed for a signal delivered |
| 4723 | while in the single-step range. Nested signals aren't a |
| 4724 | problem as they eventually all return. */ |
| 4725 | if (debug_infrun) |
| 4726 | fprintf_unfiltered (gdb_stdlog, |
| 4727 | "infrun: signal may take us out of " |
| 4728 | "single-step range\n"); |
| 4729 | |
| 4730 | insert_hp_step_resume_breakpoint_at_frame (frame); |
| 4731 | ecs->event_thread->step_after_step_resume_breakpoint = 1; |
| 4732 | /* Reset trap_expected to ensure breakpoints are re-inserted. */ |
| 4733 | ecs->event_thread->control.trap_expected = 0; |
| 4734 | keep_going (ecs); |
| 4735 | return; |
| 4736 | } |
| 4737 | |
| 4738 | /* Note: step_resume_breakpoint may be non-NULL. This occures |
| 4739 | when either there's a nested signal, or when there's a |
| 4740 | pending signal enabled just as the signal handler returns |
| 4741 | (leaving the inferior at the step-resume-breakpoint without |
| 4742 | actually executing it). Either way continue until the |
| 4743 | breakpoint is really hit. */ |
| 4744 | |
| 4745 | if (!switch_back_to_stepped_thread (ecs)) |
| 4746 | { |
| 4747 | if (debug_infrun) |
| 4748 | fprintf_unfiltered (gdb_stdlog, |
| 4749 | "infrun: random signal, keep going\n"); |
| 4750 | |
| 4751 | keep_going (ecs); |
| 4752 | } |
| 4753 | return; |
| 4754 | } |
| 4755 | |
| 4756 | process_event_stop_test (ecs); |
| 4757 | } |
| 4758 | |
| 4759 | /* Come here when we've got some debug event / signal we can explain |
| 4760 | (IOW, not a random signal), and test whether it should cause a |
| 4761 | stop, or whether we should resume the inferior (transparently). |
| 4762 | E.g., could be a breakpoint whose condition evaluates false; we |
| 4763 | could be still stepping within the line; etc. */ |
| 4764 | |
| 4765 | static void |
| 4766 | process_event_stop_test (struct execution_control_state *ecs) |
| 4767 | { |
| 4768 | struct symtab_and_line stop_pc_sal; |
| 4769 | struct frame_info *frame; |
| 4770 | struct gdbarch *gdbarch; |
| 4771 | CORE_ADDR jmp_buf_pc; |
| 4772 | struct bpstat_what what; |
| 4773 | |
| 4774 | /* Handle cases caused by hitting a breakpoint. */ |
| 4775 | |
| 4776 | frame = get_current_frame (); |
| 4777 | gdbarch = get_frame_arch (frame); |
| 4778 | |
| 4779 | what = bpstat_what (ecs->event_thread->control.stop_bpstat); |
| 4780 | |
| 4781 | if (what.call_dummy) |
| 4782 | { |
| 4783 | stop_stack_dummy = what.call_dummy; |
| 4784 | } |
| 4785 | |
| 4786 | /* If we hit an internal event that triggers symbol changes, the |
| 4787 | current frame will be invalidated within bpstat_what (e.g., if we |
| 4788 | hit an internal solib event). Re-fetch it. */ |
| 4789 | frame = get_current_frame (); |
| 4790 | gdbarch = get_frame_arch (frame); |
| 4791 | |
| 4792 | switch (what.main_action) |
| 4793 | { |
| 4794 | case BPSTAT_WHAT_SET_LONGJMP_RESUME: |
| 4795 | /* If we hit the breakpoint at longjmp while stepping, we |
| 4796 | install a momentary breakpoint at the target of the |
| 4797 | jmp_buf. */ |
| 4798 | |
| 4799 | if (debug_infrun) |
| 4800 | fprintf_unfiltered (gdb_stdlog, |
| 4801 | "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n"); |
| 4802 | |
| 4803 | ecs->event_thread->stepping_over_breakpoint = 1; |
| 4804 | |
| 4805 | if (what.is_longjmp) |
| 4806 | { |
| 4807 | struct value *arg_value; |
| 4808 | |
| 4809 | /* If we set the longjmp breakpoint via a SystemTap probe, |
| 4810 | then use it to extract the arguments. The destination PC |
| 4811 | is the third argument to the probe. */ |
| 4812 | arg_value = probe_safe_evaluate_at_pc (frame, 2); |
| 4813 | if (arg_value) |
| 4814 | { |
| 4815 | jmp_buf_pc = value_as_address (arg_value); |
| 4816 | jmp_buf_pc = gdbarch_addr_bits_remove (gdbarch, jmp_buf_pc); |
| 4817 | } |
| 4818 | else if (!gdbarch_get_longjmp_target_p (gdbarch) |
| 4819 | || !gdbarch_get_longjmp_target (gdbarch, |
| 4820 | frame, &jmp_buf_pc)) |
| 4821 | { |
| 4822 | if (debug_infrun) |
| 4823 | fprintf_unfiltered (gdb_stdlog, |
| 4824 | "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME " |
| 4825 | "(!gdbarch_get_longjmp_target)\n"); |
| 4826 | keep_going (ecs); |
| 4827 | return; |
| 4828 | } |
| 4829 | |
| 4830 | /* Insert a breakpoint at resume address. */ |
| 4831 | insert_longjmp_resume_breakpoint (gdbarch, jmp_buf_pc); |
| 4832 | } |
| 4833 | else |
| 4834 | check_exception_resume (ecs, frame); |
| 4835 | keep_going (ecs); |
| 4836 | return; |
| 4837 | |
| 4838 | case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME: |
| 4839 | { |
| 4840 | struct frame_info *init_frame; |
| 4841 | |
| 4842 | /* There are several cases to consider. |
| 4843 | |
| 4844 | 1. The initiating frame no longer exists. In this case we |
| 4845 | must stop, because the exception or longjmp has gone too |
| 4846 | far. |
| 4847 | |
| 4848 | 2. The initiating frame exists, and is the same as the |
| 4849 | current frame. We stop, because the exception or longjmp |
| 4850 | has been caught. |
| 4851 | |
| 4852 | 3. The initiating frame exists and is different from the |
| 4853 | current frame. This means the exception or longjmp has |
| 4854 | been caught beneath the initiating frame, so keep going. |
| 4855 | |
| 4856 | 4. longjmp breakpoint has been placed just to protect |
| 4857 | against stale dummy frames and user is not interested in |
| 4858 | stopping around longjmps. */ |
| 4859 | |
| 4860 | if (debug_infrun) |
| 4861 | fprintf_unfiltered (gdb_stdlog, |
| 4862 | "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n"); |
| 4863 | |
| 4864 | gdb_assert (ecs->event_thread->control.exception_resume_breakpoint |
| 4865 | != NULL); |
| 4866 | delete_exception_resume_breakpoint (ecs->event_thread); |
| 4867 | |
| 4868 | if (what.is_longjmp) |
| 4869 | { |
| 4870 | check_longjmp_breakpoint_for_call_dummy (ecs->event_thread); |
| 4871 | |
| 4872 | if (!frame_id_p (ecs->event_thread->initiating_frame)) |
| 4873 | { |
| 4874 | /* Case 4. */ |
| 4875 | keep_going (ecs); |
| 4876 | return; |
| 4877 | } |
| 4878 | } |
| 4879 | |
| 4880 | init_frame = frame_find_by_id (ecs->event_thread->initiating_frame); |
| 4881 | |
| 4882 | if (init_frame) |
| 4883 | { |
| 4884 | struct frame_id current_id |
| 4885 | = get_frame_id (get_current_frame ()); |
| 4886 | if (frame_id_eq (current_id, |
| 4887 | ecs->event_thread->initiating_frame)) |
| 4888 | { |
| 4889 | /* Case 2. Fall through. */ |
| 4890 | } |
| 4891 | else |
| 4892 | { |
| 4893 | /* Case 3. */ |
| 4894 | keep_going (ecs); |
| 4895 | return; |
| 4896 | } |
| 4897 | } |
| 4898 | |
| 4899 | /* For Cases 1 and 2, remove the step-resume breakpoint, if it |
| 4900 | exists. */ |
| 4901 | delete_step_resume_breakpoint (ecs->event_thread); |
| 4902 | |
| 4903 | end_stepping_range (ecs); |
| 4904 | } |
| 4905 | return; |
| 4906 | |
| 4907 | case BPSTAT_WHAT_SINGLE: |
| 4908 | if (debug_infrun) |
| 4909 | fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_SINGLE\n"); |
| 4910 | ecs->event_thread->stepping_over_breakpoint = 1; |
| 4911 | /* Still need to check other stuff, at least the case where we |
| 4912 | are stepping and step out of the right range. */ |
| 4913 | break; |
| 4914 | |
| 4915 | case BPSTAT_WHAT_STEP_RESUME: |
| 4916 | if (debug_infrun) |
| 4917 | fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STEP_RESUME\n"); |
| 4918 | |
| 4919 | delete_step_resume_breakpoint (ecs->event_thread); |
| 4920 | if (ecs->event_thread->control.proceed_to_finish |
| 4921 | && execution_direction == EXEC_REVERSE) |
| 4922 | { |
| 4923 | struct thread_info *tp = ecs->event_thread; |
| 4924 | |
| 4925 | /* We are finishing a function in reverse, and just hit the |
| 4926 | step-resume breakpoint at the start address of the |
| 4927 | function, and we're almost there -- just need to back up |
| 4928 | by one more single-step, which should take us back to the |
| 4929 | function call. */ |
| 4930 | tp->control.step_range_start = tp->control.step_range_end = 1; |
| 4931 | keep_going (ecs); |
| 4932 | return; |
| 4933 | } |
| 4934 | fill_in_stop_func (gdbarch, ecs); |
| 4935 | if (stop_pc == ecs->stop_func_start |
| 4936 | && execution_direction == EXEC_REVERSE) |
| 4937 | { |
| 4938 | /* We are stepping over a function call in reverse, and just |
| 4939 | hit the step-resume breakpoint at the start address of |
| 4940 | the function. Go back to single-stepping, which should |
| 4941 | take us back to the function call. */ |
| 4942 | ecs->event_thread->stepping_over_breakpoint = 1; |
| 4943 | keep_going (ecs); |
| 4944 | return; |
| 4945 | } |
| 4946 | break; |
| 4947 | |
| 4948 | case BPSTAT_WHAT_STOP_NOISY: |
| 4949 | if (debug_infrun) |
| 4950 | fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_NOISY\n"); |
| 4951 | stop_print_frame = 1; |
| 4952 | |
| 4953 | /* Assume the thread stopped for a breapoint. We'll still check |
| 4954 | whether a/the breakpoint is there when the thread is next |
| 4955 | resumed. */ |
| 4956 | ecs->event_thread->stepping_over_breakpoint = 1; |
| 4957 | |
| 4958 | stop_waiting (ecs); |
| 4959 | return; |
| 4960 | |
| 4961 | case BPSTAT_WHAT_STOP_SILENT: |
| 4962 | if (debug_infrun) |
| 4963 | fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_SILENT\n"); |
| 4964 | stop_print_frame = 0; |
| 4965 | |
| 4966 | /* Assume the thread stopped for a breapoint. We'll still check |
| 4967 | whether a/the breakpoint is there when the thread is next |
| 4968 | resumed. */ |
| 4969 | ecs->event_thread->stepping_over_breakpoint = 1; |
| 4970 | stop_waiting (ecs); |
| 4971 | return; |
| 4972 | |
| 4973 | case BPSTAT_WHAT_HP_STEP_RESUME: |
| 4974 | if (debug_infrun) |
| 4975 | fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n"); |
| 4976 | |
| 4977 | delete_step_resume_breakpoint (ecs->event_thread); |
| 4978 | if (ecs->event_thread->step_after_step_resume_breakpoint) |
| 4979 | { |
| 4980 | /* Back when the step-resume breakpoint was inserted, we |
| 4981 | were trying to single-step off a breakpoint. Go back to |
| 4982 | doing that. */ |
| 4983 | ecs->event_thread->step_after_step_resume_breakpoint = 0; |
| 4984 | ecs->event_thread->stepping_over_breakpoint = 1; |
| 4985 | keep_going (ecs); |
| 4986 | return; |
| 4987 | } |
| 4988 | break; |
| 4989 | |
| 4990 | case BPSTAT_WHAT_KEEP_CHECKING: |
| 4991 | break; |
| 4992 | } |
| 4993 | |
| 4994 | /* If we stepped a permanent breakpoint and we had a high priority |
| 4995 | step-resume breakpoint for the address we stepped, but we didn't |
| 4996 | hit it, then we must have stepped into the signal handler. The |
| 4997 | step-resume was only necessary to catch the case of _not_ |
| 4998 | stepping into the handler, so delete it, and fall through to |
| 4999 | checking whether the step finished. */ |
| 5000 | if (ecs->event_thread->stepped_breakpoint) |
| 5001 | { |
| 5002 | struct breakpoint *sr_bp |
| 5003 | = ecs->event_thread->control.step_resume_breakpoint; |
| 5004 | |
| 5005 | if (sr_bp != NULL |
| 5006 | && sr_bp->loc->permanent |
| 5007 | && sr_bp->type == bp_hp_step_resume |
| 5008 | && sr_bp->loc->address == ecs->event_thread->prev_pc) |
| 5009 | { |
| 5010 | if (debug_infrun) |
| 5011 | fprintf_unfiltered (gdb_stdlog, |
| 5012 | "infrun: stepped permanent breakpoint, stopped in " |
| 5013 | "handler\n"); |
| 5014 | delete_step_resume_breakpoint (ecs->event_thread); |
| 5015 | ecs->event_thread->step_after_step_resume_breakpoint = 0; |
| 5016 | } |
| 5017 | } |
| 5018 | |
| 5019 | /* We come here if we hit a breakpoint but should not stop for it. |
| 5020 | Possibly we also were stepping and should stop for that. So fall |
| 5021 | through and test for stepping. But, if not stepping, do not |
| 5022 | stop. */ |
| 5023 | |
| 5024 | /* In all-stop mode, if we're currently stepping but have stopped in |
| 5025 | some other thread, we need to switch back to the stepped thread. */ |
| 5026 | if (switch_back_to_stepped_thread (ecs)) |
| 5027 | return; |
| 5028 | |
| 5029 | if (ecs->event_thread->control.step_resume_breakpoint) |
| 5030 | { |
| 5031 | if (debug_infrun) |
| 5032 | fprintf_unfiltered (gdb_stdlog, |
| 5033 | "infrun: step-resume breakpoint is inserted\n"); |
| 5034 | |
| 5035 | /* Having a step-resume breakpoint overrides anything |
| 5036 | else having to do with stepping commands until |
| 5037 | that breakpoint is reached. */ |
| 5038 | keep_going (ecs); |
| 5039 | return; |
| 5040 | } |
| 5041 | |
| 5042 | if (ecs->event_thread->control.step_range_end == 0) |
| 5043 | { |
| 5044 | if (debug_infrun) |
| 5045 | fprintf_unfiltered (gdb_stdlog, "infrun: no stepping, continue\n"); |
| 5046 | /* Likewise if we aren't even stepping. */ |
| 5047 | keep_going (ecs); |
| 5048 | return; |
| 5049 | } |
| 5050 | |
| 5051 | /* Re-fetch current thread's frame in case the code above caused |
| 5052 | the frame cache to be re-initialized, making our FRAME variable |
| 5053 | a dangling pointer. */ |
| 5054 | frame = get_current_frame (); |
| 5055 | gdbarch = get_frame_arch (frame); |
| 5056 | fill_in_stop_func (gdbarch, ecs); |
| 5057 | |
| 5058 | /* If stepping through a line, keep going if still within it. |
| 5059 | |
| 5060 | Note that step_range_end is the address of the first instruction |
| 5061 | beyond the step range, and NOT the address of the last instruction |
| 5062 | within it! |
| 5063 | |
| 5064 | Note also that during reverse execution, we may be stepping |
| 5065 | through a function epilogue and therefore must detect when |
| 5066 | the current-frame changes in the middle of a line. */ |
| 5067 | |
| 5068 | if (pc_in_thread_step_range (stop_pc, ecs->event_thread) |
| 5069 | && (execution_direction != EXEC_REVERSE |
| 5070 | || frame_id_eq (get_frame_id (frame), |
| 5071 | ecs->event_thread->control.step_frame_id))) |
| 5072 | { |
| 5073 | if (debug_infrun) |
| 5074 | fprintf_unfiltered |
| 5075 | (gdb_stdlog, "infrun: stepping inside range [%s-%s]\n", |
| 5076 | paddress (gdbarch, ecs->event_thread->control.step_range_start), |
| 5077 | paddress (gdbarch, ecs->event_thread->control.step_range_end)); |
| 5078 | |
| 5079 | /* Tentatively re-enable range stepping; `resume' disables it if |
| 5080 | necessary (e.g., if we're stepping over a breakpoint or we |
| 5081 | have software watchpoints). */ |
| 5082 | ecs->event_thread->control.may_range_step = 1; |
| 5083 | |
| 5084 | /* When stepping backward, stop at beginning of line range |
| 5085 | (unless it's the function entry point, in which case |
| 5086 | keep going back to the call point). */ |
| 5087 | if (stop_pc == ecs->event_thread->control.step_range_start |
| 5088 | && stop_pc != ecs->stop_func_start |
| 5089 | && execution_direction == EXEC_REVERSE) |
| 5090 | end_stepping_range (ecs); |
| 5091 | else |
| 5092 | keep_going (ecs); |
| 5093 | |
| 5094 | return; |
| 5095 | } |
| 5096 | |
| 5097 | /* We stepped out of the stepping range. */ |
| 5098 | |
| 5099 | /* If we are stepping at the source level and entered the runtime |
| 5100 | loader dynamic symbol resolution code... |
| 5101 | |
| 5102 | EXEC_FORWARD: we keep on single stepping until we exit the run |
| 5103 | time loader code and reach the callee's address. |
| 5104 | |
| 5105 | EXEC_REVERSE: we've already executed the callee (backward), and |
| 5106 | the runtime loader code is handled just like any other |
| 5107 | undebuggable function call. Now we need only keep stepping |
| 5108 | backward through the trampoline code, and that's handled further |
| 5109 | down, so there is nothing for us to do here. */ |
| 5110 | |
| 5111 | if (execution_direction != EXEC_REVERSE |
| 5112 | && ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE |
| 5113 | && in_solib_dynsym_resolve_code (stop_pc)) |
| 5114 | { |
| 5115 | CORE_ADDR pc_after_resolver = |
| 5116 | gdbarch_skip_solib_resolver (gdbarch, stop_pc); |
| 5117 | |
| 5118 | if (debug_infrun) |
| 5119 | fprintf_unfiltered (gdb_stdlog, |
| 5120 | "infrun: stepped into dynsym resolve code\n"); |
| 5121 | |
| 5122 | if (pc_after_resolver) |
| 5123 | { |
| 5124 | /* Set up a step-resume breakpoint at the address |
| 5125 | indicated by SKIP_SOLIB_RESOLVER. */ |
| 5126 | struct symtab_and_line sr_sal; |
| 5127 | |
| 5128 | init_sal (&sr_sal); |
| 5129 | sr_sal.pc = pc_after_resolver; |
| 5130 | sr_sal.pspace = get_frame_program_space (frame); |
| 5131 | |
| 5132 | insert_step_resume_breakpoint_at_sal (gdbarch, |
| 5133 | sr_sal, null_frame_id); |
| 5134 | } |
| 5135 | |
| 5136 | keep_going (ecs); |
| 5137 | return; |
| 5138 | } |
| 5139 | |
| 5140 | if (ecs->event_thread->control.step_range_end != 1 |
| 5141 | && (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE |
| 5142 | || ecs->event_thread->control.step_over_calls == STEP_OVER_ALL) |
| 5143 | && get_frame_type (frame) == SIGTRAMP_FRAME) |
| 5144 | { |
| 5145 | if (debug_infrun) |
| 5146 | fprintf_unfiltered (gdb_stdlog, |
| 5147 | "infrun: stepped into signal trampoline\n"); |
| 5148 | /* The inferior, while doing a "step" or "next", has ended up in |
| 5149 | a signal trampoline (either by a signal being delivered or by |
| 5150 | the signal handler returning). Just single-step until the |
| 5151 | inferior leaves the trampoline (either by calling the handler |
| 5152 | or returning). */ |
| 5153 | keep_going (ecs); |
| 5154 | return; |
| 5155 | } |
| 5156 | |
| 5157 | /* If we're in the return path from a shared library trampoline, |
| 5158 | we want to proceed through the trampoline when stepping. */ |
| 5159 | /* macro/2012-04-25: This needs to come before the subroutine |
| 5160 | call check below as on some targets return trampolines look |
| 5161 | like subroutine calls (MIPS16 return thunks). */ |
| 5162 | if (gdbarch_in_solib_return_trampoline (gdbarch, |
| 5163 | stop_pc, ecs->stop_func_name) |
| 5164 | && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE) |
| 5165 | { |
| 5166 | /* Determine where this trampoline returns. */ |
| 5167 | CORE_ADDR real_stop_pc; |
| 5168 | |
| 5169 | real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc); |
| 5170 | |
| 5171 | if (debug_infrun) |
| 5172 | fprintf_unfiltered (gdb_stdlog, |
| 5173 | "infrun: stepped into solib return tramp\n"); |
| 5174 | |
| 5175 | /* Only proceed through if we know where it's going. */ |
| 5176 | if (real_stop_pc) |
| 5177 | { |
| 5178 | /* And put the step-breakpoint there and go until there. */ |
| 5179 | struct symtab_and_line sr_sal; |
| 5180 | |
| 5181 | init_sal (&sr_sal); /* initialize to zeroes */ |
| 5182 | sr_sal.pc = real_stop_pc; |
| 5183 | sr_sal.section = find_pc_overlay (sr_sal.pc); |
| 5184 | sr_sal.pspace = get_frame_program_space (frame); |
| 5185 | |
| 5186 | /* Do not specify what the fp should be when we stop since |
| 5187 | on some machines the prologue is where the new fp value |
| 5188 | is established. */ |
| 5189 | insert_step_resume_breakpoint_at_sal (gdbarch, |
| 5190 | sr_sal, null_frame_id); |
| 5191 | |
| 5192 | /* Restart without fiddling with the step ranges or |
| 5193 | other state. */ |
| 5194 | keep_going (ecs); |
| 5195 | return; |
| 5196 | } |
| 5197 | } |
| 5198 | |
| 5199 | /* Check for subroutine calls. The check for the current frame |
| 5200 | equalling the step ID is not necessary - the check of the |
| 5201 | previous frame's ID is sufficient - but it is a common case and |
| 5202 | cheaper than checking the previous frame's ID. |
| 5203 | |
| 5204 | NOTE: frame_id_eq will never report two invalid frame IDs as |
| 5205 | being equal, so to get into this block, both the current and |
| 5206 | previous frame must have valid frame IDs. */ |
| 5207 | /* The outer_frame_id check is a heuristic to detect stepping |
| 5208 | through startup code. If we step over an instruction which |
| 5209 | sets the stack pointer from an invalid value to a valid value, |
| 5210 | we may detect that as a subroutine call from the mythical |
| 5211 | "outermost" function. This could be fixed by marking |
| 5212 | outermost frames as !stack_p,code_p,special_p. Then the |
| 5213 | initial outermost frame, before sp was valid, would |
| 5214 | have code_addr == &_start. See the comment in frame_id_eq |
| 5215 | for more. */ |
| 5216 | if (!frame_id_eq (get_stack_frame_id (frame), |
| 5217 | ecs->event_thread->control.step_stack_frame_id) |
| 5218 | && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()), |
| 5219 | ecs->event_thread->control.step_stack_frame_id) |
| 5220 | && (!frame_id_eq (ecs->event_thread->control.step_stack_frame_id, |
| 5221 | outer_frame_id) |
| 5222 | || (ecs->event_thread->control.step_start_function |
| 5223 | != find_pc_function (stop_pc))))) |
| 5224 | { |
| 5225 | CORE_ADDR real_stop_pc; |
| 5226 | |
| 5227 | if (debug_infrun) |
| 5228 | fprintf_unfiltered (gdb_stdlog, "infrun: stepped into subroutine\n"); |
| 5229 | |
| 5230 | if (ecs->event_thread->control.step_over_calls == STEP_OVER_NONE) |
| 5231 | { |
| 5232 | /* I presume that step_over_calls is only 0 when we're |
| 5233 | supposed to be stepping at the assembly language level |
| 5234 | ("stepi"). Just stop. */ |
| 5235 | /* And this works the same backward as frontward. MVS */ |
| 5236 | end_stepping_range (ecs); |
| 5237 | return; |
| 5238 | } |
| 5239 | |
| 5240 | /* Reverse stepping through solib trampolines. */ |
| 5241 | |
| 5242 | if (execution_direction == EXEC_REVERSE |
| 5243 | && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE |
| 5244 | && (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc) |
| 5245 | || (ecs->stop_func_start == 0 |
| 5246 | && in_solib_dynsym_resolve_code (stop_pc)))) |
| 5247 | { |
| 5248 | /* Any solib trampoline code can be handled in reverse |
| 5249 | by simply continuing to single-step. We have already |
| 5250 | executed the solib function (backwards), and a few |
| 5251 | steps will take us back through the trampoline to the |
| 5252 | caller. */ |
| 5253 | keep_going (ecs); |
| 5254 | return; |
| 5255 | } |
| 5256 | |
| 5257 | if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL) |
| 5258 | { |
| 5259 | /* We're doing a "next". |
| 5260 | |
| 5261 | Normal (forward) execution: set a breakpoint at the |
| 5262 | callee's return address (the address at which the caller |
| 5263 | will resume). |
| 5264 | |
| 5265 | Reverse (backward) execution. set the step-resume |
| 5266 | breakpoint at the start of the function that we just |
| 5267 | stepped into (backwards), and continue to there. When we |
| 5268 | get there, we'll need to single-step back to the caller. */ |
| 5269 | |
| 5270 | if (execution_direction == EXEC_REVERSE) |
| 5271 | { |
| 5272 | /* If we're already at the start of the function, we've either |
| 5273 | just stepped backward into a single instruction function, |
| 5274 | or stepped back out of a signal handler to the first instruction |
| 5275 | of the function. Just keep going, which will single-step back |
| 5276 | to the caller. */ |
| 5277 | if (ecs->stop_func_start != stop_pc && ecs->stop_func_start != 0) |
| 5278 | { |
| 5279 | struct symtab_and_line sr_sal; |
| 5280 | |
| 5281 | /* Normal function call return (static or dynamic). */ |
| 5282 | init_sal (&sr_sal); |
| 5283 | sr_sal.pc = ecs->stop_func_start; |
| 5284 | sr_sal.pspace = get_frame_program_space (frame); |
| 5285 | insert_step_resume_breakpoint_at_sal (gdbarch, |
| 5286 | sr_sal, null_frame_id); |
| 5287 | } |
| 5288 | } |
| 5289 | else |
| 5290 | insert_step_resume_breakpoint_at_caller (frame); |
| 5291 | |
| 5292 | keep_going (ecs); |
| 5293 | return; |
| 5294 | } |
| 5295 | |
| 5296 | /* If we are in a function call trampoline (a stub between the |
| 5297 | calling routine and the real function), locate the real |
| 5298 | function. That's what tells us (a) whether we want to step |
| 5299 | into it at all, and (b) what prologue we want to run to the |
| 5300 | end of, if we do step into it. */ |
| 5301 | real_stop_pc = skip_language_trampoline (frame, stop_pc); |
| 5302 | if (real_stop_pc == 0) |
| 5303 | real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc); |
| 5304 | if (real_stop_pc != 0) |
| 5305 | ecs->stop_func_start = real_stop_pc; |
| 5306 | |
| 5307 | if (real_stop_pc != 0 && in_solib_dynsym_resolve_code (real_stop_pc)) |
| 5308 | { |
| 5309 | struct symtab_and_line sr_sal; |
| 5310 | |
| 5311 | init_sal (&sr_sal); |
| 5312 | sr_sal.pc = ecs->stop_func_start; |
| 5313 | sr_sal.pspace = get_frame_program_space (frame); |
| 5314 | |
| 5315 | insert_step_resume_breakpoint_at_sal (gdbarch, |
| 5316 | sr_sal, null_frame_id); |
| 5317 | keep_going (ecs); |
| 5318 | return; |
| 5319 | } |
| 5320 | |
| 5321 | /* If we have line number information for the function we are |
| 5322 | thinking of stepping into and the function isn't on the skip |
| 5323 | list, step into it. |
| 5324 | |
| 5325 | If there are several symtabs at that PC (e.g. with include |
| 5326 | files), just want to know whether *any* of them have line |
| 5327 | numbers. find_pc_line handles this. */ |
| 5328 | { |
| 5329 | struct symtab_and_line tmp_sal; |
| 5330 | |
| 5331 | tmp_sal = find_pc_line (ecs->stop_func_start, 0); |
| 5332 | if (tmp_sal.line != 0 |
| 5333 | && !function_name_is_marked_for_skip (ecs->stop_func_name, |
| 5334 | &tmp_sal)) |
| 5335 | { |
| 5336 | if (execution_direction == EXEC_REVERSE) |
| 5337 | handle_step_into_function_backward (gdbarch, ecs); |
| 5338 | else |
| 5339 | handle_step_into_function (gdbarch, ecs); |
| 5340 | return; |
| 5341 | } |
| 5342 | } |
| 5343 | |
| 5344 | /* If we have no line number and the step-stop-if-no-debug is |
| 5345 | set, we stop the step so that the user has a chance to switch |
| 5346 | in assembly mode. */ |
| 5347 | if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE |
| 5348 | && step_stop_if_no_debug) |
| 5349 | { |
| 5350 | end_stepping_range (ecs); |
| 5351 | return; |
| 5352 | } |
| 5353 | |
| 5354 | if (execution_direction == EXEC_REVERSE) |
| 5355 | { |
| 5356 | /* If we're already at the start of the function, we've either just |
| 5357 | stepped backward into a single instruction function without line |
| 5358 | number info, or stepped back out of a signal handler to the first |
| 5359 | instruction of the function without line number info. Just keep |
| 5360 | going, which will single-step back to the caller. */ |
| 5361 | if (ecs->stop_func_start != stop_pc) |
| 5362 | { |
| 5363 | /* Set a breakpoint at callee's start address. |
| 5364 | From there we can step once and be back in the caller. */ |
| 5365 | struct symtab_and_line sr_sal; |
| 5366 | |
| 5367 | init_sal (&sr_sal); |
| 5368 | sr_sal.pc = ecs->stop_func_start; |
| 5369 | sr_sal.pspace = get_frame_program_space (frame); |
| 5370 | insert_step_resume_breakpoint_at_sal (gdbarch, |
| 5371 | sr_sal, null_frame_id); |
| 5372 | } |
| 5373 | } |
| 5374 | else |
| 5375 | /* Set a breakpoint at callee's return address (the address |
| 5376 | at which the caller will resume). */ |
| 5377 | insert_step_resume_breakpoint_at_caller (frame); |
| 5378 | |
| 5379 | keep_going (ecs); |
| 5380 | return; |
| 5381 | } |
| 5382 | |
| 5383 | /* Reverse stepping through solib trampolines. */ |
| 5384 | |
| 5385 | if (execution_direction == EXEC_REVERSE |
| 5386 | && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE) |
| 5387 | { |
| 5388 | if (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc) |
| 5389 | || (ecs->stop_func_start == 0 |
| 5390 | && in_solib_dynsym_resolve_code (stop_pc))) |
| 5391 | { |
| 5392 | /* Any solib trampoline code can be handled in reverse |
| 5393 | by simply continuing to single-step. We have already |
| 5394 | executed the solib function (backwards), and a few |
| 5395 | steps will take us back through the trampoline to the |
| 5396 | caller. */ |
| 5397 | keep_going (ecs); |
| 5398 | return; |
| 5399 | } |
| 5400 | else if (in_solib_dynsym_resolve_code (stop_pc)) |
| 5401 | { |
| 5402 | /* Stepped backward into the solib dynsym resolver. |
| 5403 | Set a breakpoint at its start and continue, then |
| 5404 | one more step will take us out. */ |
| 5405 | struct symtab_and_line sr_sal; |
| 5406 | |
| 5407 | init_sal (&sr_sal); |
| 5408 | sr_sal.pc = ecs->stop_func_start; |
| 5409 | sr_sal.pspace = get_frame_program_space (frame); |
| 5410 | insert_step_resume_breakpoint_at_sal (gdbarch, |
| 5411 | sr_sal, null_frame_id); |
| 5412 | keep_going (ecs); |
| 5413 | return; |
| 5414 | } |
| 5415 | } |
| 5416 | |
| 5417 | stop_pc_sal = find_pc_line (stop_pc, 0); |
| 5418 | |
| 5419 | /* NOTE: tausq/2004-05-24: This if block used to be done before all |
| 5420 | the trampoline processing logic, however, there are some trampolines |
| 5421 | that have no names, so we should do trampoline handling first. */ |
| 5422 | if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE |
| 5423 | && ecs->stop_func_name == NULL |
| 5424 | && stop_pc_sal.line == 0) |
| 5425 | { |
| 5426 | if (debug_infrun) |
| 5427 | fprintf_unfiltered (gdb_stdlog, |
| 5428 | "infrun: stepped into undebuggable function\n"); |
| 5429 | |
| 5430 | /* The inferior just stepped into, or returned to, an |
| 5431 | undebuggable function (where there is no debugging information |
| 5432 | and no line number corresponding to the address where the |
| 5433 | inferior stopped). Since we want to skip this kind of code, |
| 5434 | we keep going until the inferior returns from this |
| 5435 | function - unless the user has asked us not to (via |
| 5436 | set step-mode) or we no longer know how to get back |
| 5437 | to the call site. */ |
| 5438 | if (step_stop_if_no_debug |
| 5439 | || !frame_id_p (frame_unwind_caller_id (frame))) |
| 5440 | { |
| 5441 | /* If we have no line number and the step-stop-if-no-debug |
| 5442 | is set, we stop the step so that the user has a chance to |
| 5443 | switch in assembly mode. */ |
| 5444 | end_stepping_range (ecs); |
| 5445 | return; |
| 5446 | } |
| 5447 | else |
| 5448 | { |
| 5449 | /* Set a breakpoint at callee's return address (the address |
| 5450 | at which the caller will resume). */ |
| 5451 | insert_step_resume_breakpoint_at_caller (frame); |
| 5452 | keep_going (ecs); |
| 5453 | return; |
| 5454 | } |
| 5455 | } |
| 5456 | |
| 5457 | if (ecs->event_thread->control.step_range_end == 1) |
| 5458 | { |
| 5459 | /* It is stepi or nexti. We always want to stop stepping after |
| 5460 | one instruction. */ |
| 5461 | if (debug_infrun) |
| 5462 | fprintf_unfiltered (gdb_stdlog, "infrun: stepi/nexti\n"); |
| 5463 | end_stepping_range (ecs); |
| 5464 | return; |
| 5465 | } |
| 5466 | |
| 5467 | if (stop_pc_sal.line == 0) |
| 5468 | { |
| 5469 | /* We have no line number information. That means to stop |
| 5470 | stepping (does this always happen right after one instruction, |
| 5471 | when we do "s" in a function with no line numbers, |
| 5472 | or can this happen as a result of a return or longjmp?). */ |
| 5473 | if (debug_infrun) |
| 5474 | fprintf_unfiltered (gdb_stdlog, "infrun: no line number info\n"); |
| 5475 | end_stepping_range (ecs); |
| 5476 | return; |
| 5477 | } |
| 5478 | |
| 5479 | /* Look for "calls" to inlined functions, part one. If the inline |
| 5480 | frame machinery detected some skipped call sites, we have entered |
| 5481 | a new inline function. */ |
| 5482 | |
| 5483 | if (frame_id_eq (get_frame_id (get_current_frame ()), |
| 5484 | ecs->event_thread->control.step_frame_id) |
| 5485 | && inline_skipped_frames (ecs->ptid)) |
| 5486 | { |
| 5487 | struct symtab_and_line call_sal; |
| 5488 | |
| 5489 | if (debug_infrun) |
| 5490 | fprintf_unfiltered (gdb_stdlog, |
| 5491 | "infrun: stepped into inlined function\n"); |
| 5492 | |
| 5493 | find_frame_sal (get_current_frame (), &call_sal); |
| 5494 | |
| 5495 | if (ecs->event_thread->control.step_over_calls != STEP_OVER_ALL) |
| 5496 | { |
| 5497 | /* For "step", we're going to stop. But if the call site |
| 5498 | for this inlined function is on the same source line as |
| 5499 | we were previously stepping, go down into the function |
| 5500 | first. Otherwise stop at the call site. */ |
| 5501 | |
| 5502 | if (call_sal.line == ecs->event_thread->current_line |
| 5503 | && call_sal.symtab == ecs->event_thread->current_symtab) |
| 5504 | step_into_inline_frame (ecs->ptid); |
| 5505 | |
| 5506 | end_stepping_range (ecs); |
| 5507 | return; |
| 5508 | } |
| 5509 | else |
| 5510 | { |
| 5511 | /* For "next", we should stop at the call site if it is on a |
| 5512 | different source line. Otherwise continue through the |
| 5513 | inlined function. */ |
| 5514 | if (call_sal.line == ecs->event_thread->current_line |
| 5515 | && call_sal.symtab == ecs->event_thread->current_symtab) |
| 5516 | keep_going (ecs); |
| 5517 | else |
| 5518 | end_stepping_range (ecs); |
| 5519 | return; |
| 5520 | } |
| 5521 | } |
| 5522 | |
| 5523 | /* Look for "calls" to inlined functions, part two. If we are still |
| 5524 | in the same real function we were stepping through, but we have |
| 5525 | to go further up to find the exact frame ID, we are stepping |
| 5526 | through a more inlined call beyond its call site. */ |
| 5527 | |
| 5528 | if (get_frame_type (get_current_frame ()) == INLINE_FRAME |
| 5529 | && !frame_id_eq (get_frame_id (get_current_frame ()), |
| 5530 | ecs->event_thread->control.step_frame_id) |
| 5531 | && stepped_in_from (get_current_frame (), |
| 5532 | ecs->event_thread->control.step_frame_id)) |
| 5533 | { |
| 5534 | if (debug_infrun) |
| 5535 | fprintf_unfiltered (gdb_stdlog, |
| 5536 | "infrun: stepping through inlined function\n"); |
| 5537 | |
| 5538 | if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL) |
| 5539 | keep_going (ecs); |
| 5540 | else |
| 5541 | end_stepping_range (ecs); |
| 5542 | return; |
| 5543 | } |
| 5544 | |
| 5545 | if ((stop_pc == stop_pc_sal.pc) |
| 5546 | && (ecs->event_thread->current_line != stop_pc_sal.line |
| 5547 | || ecs->event_thread->current_symtab != stop_pc_sal.symtab)) |
| 5548 | { |
| 5549 | /* We are at the start of a different line. So stop. Note that |
| 5550 | we don't stop if we step into the middle of a different line. |
| 5551 | That is said to make things like for (;;) statements work |
| 5552 | better. */ |
| 5553 | if (debug_infrun) |
| 5554 | fprintf_unfiltered (gdb_stdlog, |
| 5555 | "infrun: stepped to a different line\n"); |
| 5556 | end_stepping_range (ecs); |
| 5557 | return; |
| 5558 | } |
| 5559 | |
| 5560 | /* We aren't done stepping. |
| 5561 | |
| 5562 | Optimize by setting the stepping range to the line. |
| 5563 | (We might not be in the original line, but if we entered a |
| 5564 | new line in mid-statement, we continue stepping. This makes |
| 5565 | things like for(;;) statements work better.) */ |
| 5566 | |
| 5567 | ecs->event_thread->control.step_range_start = stop_pc_sal.pc; |
| 5568 | ecs->event_thread->control.step_range_end = stop_pc_sal.end; |
| 5569 | ecs->event_thread->control.may_range_step = 1; |
| 5570 | set_step_info (frame, stop_pc_sal); |
| 5571 | |
| 5572 | if (debug_infrun) |
| 5573 | fprintf_unfiltered (gdb_stdlog, "infrun: keep going\n"); |
| 5574 | keep_going (ecs); |
| 5575 | } |
| 5576 | |
| 5577 | /* In all-stop mode, if we're currently stepping but have stopped in |
| 5578 | some other thread, we may need to switch back to the stepped |
| 5579 | thread. Returns true we set the inferior running, false if we left |
| 5580 | it stopped (and the event needs further processing). */ |
| 5581 | |
| 5582 | static int |
| 5583 | switch_back_to_stepped_thread (struct execution_control_state *ecs) |
| 5584 | { |
| 5585 | if (!non_stop) |
| 5586 | { |
| 5587 | struct thread_info *tp; |
| 5588 | struct thread_info *stepping_thread; |
| 5589 | struct thread_info *step_over; |
| 5590 | |
| 5591 | /* If any thread is blocked on some internal breakpoint, and we |
| 5592 | simply need to step over that breakpoint to get it going |
| 5593 | again, do that first. */ |
| 5594 | |
| 5595 | /* However, if we see an event for the stepping thread, then we |
| 5596 | know all other threads have been moved past their breakpoints |
| 5597 | already. Let the caller check whether the step is finished, |
| 5598 | etc., before deciding to move it past a breakpoint. */ |
| 5599 | if (ecs->event_thread->control.step_range_end != 0) |
| 5600 | return 0; |
| 5601 | |
| 5602 | /* Check if the current thread is blocked on an incomplete |
| 5603 | step-over, interrupted by a random signal. */ |
| 5604 | if (ecs->event_thread->control.trap_expected |
| 5605 | && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_TRAP) |
| 5606 | { |
| 5607 | if (debug_infrun) |
| 5608 | { |
| 5609 | fprintf_unfiltered (gdb_stdlog, |
| 5610 | "infrun: need to finish step-over of [%s]\n", |
| 5611 | target_pid_to_str (ecs->event_thread->ptid)); |
| 5612 | } |
| 5613 | keep_going (ecs); |
| 5614 | return 1; |
| 5615 | } |
| 5616 | |
| 5617 | /* Check if the current thread is blocked by a single-step |
| 5618 | breakpoint of another thread. */ |
| 5619 | if (ecs->hit_singlestep_breakpoint) |
| 5620 | { |
| 5621 | if (debug_infrun) |
| 5622 | { |
| 5623 | fprintf_unfiltered (gdb_stdlog, |
| 5624 | "infrun: need to step [%s] over single-step " |
| 5625 | "breakpoint\n", |
| 5626 | target_pid_to_str (ecs->ptid)); |
| 5627 | } |
| 5628 | keep_going (ecs); |
| 5629 | return 1; |
| 5630 | } |
| 5631 | |
| 5632 | /* Otherwise, we no longer expect a trap in the current thread. |
| 5633 | Clear the trap_expected flag before switching back -- this is |
| 5634 | what keep_going does as well, if we call it. */ |
| 5635 | ecs->event_thread->control.trap_expected = 0; |
| 5636 | |
| 5637 | /* Likewise, clear the signal if it should not be passed. */ |
| 5638 | if (!signal_program[ecs->event_thread->suspend.stop_signal]) |
| 5639 | ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0; |
| 5640 | |
| 5641 | /* If scheduler locking applies even if not stepping, there's no |
| 5642 | need to walk over threads. Above we've checked whether the |
| 5643 | current thread is stepping. If some other thread not the |
| 5644 | event thread is stepping, then it must be that scheduler |
| 5645 | locking is not in effect. */ |
| 5646 | if (schedlock_applies (ecs->event_thread)) |
| 5647 | return 0; |
| 5648 | |
| 5649 | /* Look for the stepping/nexting thread, and check if any other |
| 5650 | thread other than the stepping thread needs to start a |
| 5651 | step-over. Do all step-overs before actually proceeding with |
| 5652 | step/next/etc. */ |
| 5653 | stepping_thread = NULL; |
| 5654 | step_over = NULL; |
| 5655 | ALL_NON_EXITED_THREADS (tp) |
| 5656 | { |
| 5657 | /* Ignore threads of processes we're not resuming. */ |
| 5658 | if (!sched_multi |
| 5659 | && ptid_get_pid (tp->ptid) != ptid_get_pid (inferior_ptid)) |
| 5660 | continue; |
| 5661 | |
| 5662 | /* When stepping over a breakpoint, we lock all threads |
| 5663 | except the one that needs to move past the breakpoint. |
| 5664 | If a non-event thread has this set, the "incomplete |
| 5665 | step-over" check above should have caught it earlier. */ |
| 5666 | gdb_assert (!tp->control.trap_expected); |
| 5667 | |
| 5668 | /* Did we find the stepping thread? */ |
| 5669 | if (tp->control.step_range_end) |
| 5670 | { |
| 5671 | /* Yep. There should only one though. */ |
| 5672 | gdb_assert (stepping_thread == NULL); |
| 5673 | |
| 5674 | /* The event thread is handled at the top, before we |
| 5675 | enter this loop. */ |
| 5676 | gdb_assert (tp != ecs->event_thread); |
| 5677 | |
| 5678 | /* If some thread other than the event thread is |
| 5679 | stepping, then scheduler locking can't be in effect, |
| 5680 | otherwise we wouldn't have resumed the current event |
| 5681 | thread in the first place. */ |
| 5682 | gdb_assert (!schedlock_applies (tp)); |
| 5683 | |
| 5684 | stepping_thread = tp; |
| 5685 | } |
| 5686 | else if (thread_still_needs_step_over (tp)) |
| 5687 | { |
| 5688 | step_over = tp; |
| 5689 | |
| 5690 | /* At the top we've returned early if the event thread |
| 5691 | is stepping. If some other thread not the event |
| 5692 | thread is stepping, then scheduler locking can't be |
| 5693 | in effect, and we can resume this thread. No need to |
| 5694 | keep looking for the stepping thread then. */ |
| 5695 | break; |
| 5696 | } |
| 5697 | } |
| 5698 | |
| 5699 | if (step_over != NULL) |
| 5700 | { |
| 5701 | tp = step_over; |
| 5702 | if (debug_infrun) |
| 5703 | { |
| 5704 | fprintf_unfiltered (gdb_stdlog, |
| 5705 | "infrun: need to step-over [%s]\n", |
| 5706 | target_pid_to_str (tp->ptid)); |
| 5707 | } |
| 5708 | |
| 5709 | /* Only the stepping thread should have this set. */ |
| 5710 | gdb_assert (tp->control.step_range_end == 0); |
| 5711 | |
| 5712 | ecs->ptid = tp->ptid; |
| 5713 | ecs->event_thread = tp; |
| 5714 | switch_to_thread (ecs->ptid); |
| 5715 | keep_going (ecs); |
| 5716 | return 1; |
| 5717 | } |
| 5718 | |
| 5719 | if (stepping_thread != NULL) |
| 5720 | { |
| 5721 | struct frame_info *frame; |
| 5722 | struct gdbarch *gdbarch; |
| 5723 | |
| 5724 | tp = stepping_thread; |
| 5725 | |
| 5726 | /* If the stepping thread exited, then don't try to switch |
| 5727 | back and resume it, which could fail in several different |
| 5728 | ways depending on the target. Instead, just keep going. |
| 5729 | |
| 5730 | We can find a stepping dead thread in the thread list in |
| 5731 | two cases: |
| 5732 | |
| 5733 | - The target supports thread exit events, and when the |
| 5734 | target tries to delete the thread from the thread list, |
| 5735 | inferior_ptid pointed at the exiting thread. In such |
| 5736 | case, calling delete_thread does not really remove the |
| 5737 | thread from the list; instead, the thread is left listed, |
| 5738 | with 'exited' state. |
| 5739 | |
| 5740 | - The target's debug interface does not support thread |
| 5741 | exit events, and so we have no idea whatsoever if the |
| 5742 | previously stepping thread is still alive. For that |
| 5743 | reason, we need to synchronously query the target |
| 5744 | now. */ |
| 5745 | if (is_exited (tp->ptid) |
| 5746 | || !target_thread_alive (tp->ptid)) |
| 5747 | { |
| 5748 | if (debug_infrun) |
| 5749 | fprintf_unfiltered (gdb_stdlog, |
| 5750 | "infrun: not switching back to " |
| 5751 | "stepped thread, it has vanished\n"); |
| 5752 | |
| 5753 | delete_thread (tp->ptid); |
| 5754 | keep_going (ecs); |
| 5755 | return 1; |
| 5756 | } |
| 5757 | |
| 5758 | if (debug_infrun) |
| 5759 | fprintf_unfiltered (gdb_stdlog, |
| 5760 | "infrun: switching back to stepped thread\n"); |
| 5761 | |
| 5762 | ecs->event_thread = tp; |
| 5763 | ecs->ptid = tp->ptid; |
| 5764 | context_switch (ecs->ptid); |
| 5765 | |
| 5766 | stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid)); |
| 5767 | frame = get_current_frame (); |
| 5768 | gdbarch = get_frame_arch (frame); |
| 5769 | |
| 5770 | /* If the PC of the thread we were trying to single-step has |
| 5771 | changed, then that thread has trapped or been signaled, |
| 5772 | but the event has not been reported to GDB yet. Re-poll |
| 5773 | the target looking for this particular thread's event |
| 5774 | (i.e. temporarily enable schedlock) by: |
| 5775 | |
| 5776 | - setting a break at the current PC |
| 5777 | - resuming that particular thread, only (by setting |
| 5778 | trap expected) |
| 5779 | |
| 5780 | This prevents us continuously moving the single-step |
| 5781 | breakpoint forward, one instruction at a time, |
| 5782 | overstepping. */ |
| 5783 | |
| 5784 | if (stop_pc != tp->prev_pc) |
| 5785 | { |
| 5786 | ptid_t resume_ptid; |
| 5787 | |
| 5788 | if (debug_infrun) |
| 5789 | fprintf_unfiltered (gdb_stdlog, |
| 5790 | "infrun: expected thread advanced also\n"); |
| 5791 | |
| 5792 | /* Clear the info of the previous step-over, as it's no |
| 5793 | longer valid. It's what keep_going would do too, if |
| 5794 | we called it. Must do this before trying to insert |
| 5795 | the sss breakpoint, otherwise if we were previously |
| 5796 | trying to step over this exact address in another |
| 5797 | thread, the breakpoint ends up not installed. */ |
| 5798 | clear_step_over_info (); |
| 5799 | |
| 5800 | insert_single_step_breakpoint (get_frame_arch (frame), |
| 5801 | get_frame_address_space (frame), |
| 5802 | stop_pc); |
| 5803 | |
| 5804 | resume_ptid = user_visible_resume_ptid (tp->control.stepping_command); |
| 5805 | do_target_resume (resume_ptid, |
| 5806 | currently_stepping (tp), GDB_SIGNAL_0); |
| 5807 | prepare_to_wait (ecs); |
| 5808 | } |
| 5809 | else |
| 5810 | { |
| 5811 | if (debug_infrun) |
| 5812 | fprintf_unfiltered (gdb_stdlog, |
| 5813 | "infrun: expected thread still " |
| 5814 | "hasn't advanced\n"); |
| 5815 | keep_going (ecs); |
| 5816 | } |
| 5817 | |
| 5818 | return 1; |
| 5819 | } |
| 5820 | } |
| 5821 | return 0; |
| 5822 | } |
| 5823 | |
| 5824 | /* Is thread TP in the middle of single-stepping? */ |
| 5825 | |
| 5826 | static int |
| 5827 | currently_stepping (struct thread_info *tp) |
| 5828 | { |
| 5829 | return ((tp->control.step_range_end |
| 5830 | && tp->control.step_resume_breakpoint == NULL) |
| 5831 | || tp->control.trap_expected |
| 5832 | || tp->stepped_breakpoint |
| 5833 | || bpstat_should_step ()); |
| 5834 | } |
| 5835 | |
| 5836 | /* Inferior has stepped into a subroutine call with source code that |
| 5837 | we should not step over. Do step to the first line of code in |
| 5838 | it. */ |
| 5839 | |
| 5840 | static void |
| 5841 | handle_step_into_function (struct gdbarch *gdbarch, |
| 5842 | struct execution_control_state *ecs) |
| 5843 | { |
| 5844 | struct compunit_symtab *cust; |
| 5845 | struct symtab_and_line stop_func_sal, sr_sal; |
| 5846 | |
| 5847 | fill_in_stop_func (gdbarch, ecs); |
| 5848 | |
| 5849 | cust = find_pc_compunit_symtab (stop_pc); |
| 5850 | if (cust != NULL && compunit_language (cust) != language_asm) |
| 5851 | ecs->stop_func_start = gdbarch_skip_prologue (gdbarch, |
| 5852 | ecs->stop_func_start); |
| 5853 | |
| 5854 | stop_func_sal = find_pc_line (ecs->stop_func_start, 0); |
| 5855 | /* Use the step_resume_break to step until the end of the prologue, |
| 5856 | even if that involves jumps (as it seems to on the vax under |
| 5857 | 4.2). */ |
| 5858 | /* If the prologue ends in the middle of a source line, continue to |
| 5859 | the end of that source line (if it is still within the function). |
| 5860 | Otherwise, just go to end of prologue. */ |
| 5861 | if (stop_func_sal.end |
| 5862 | && stop_func_sal.pc != ecs->stop_func_start |
| 5863 | && stop_func_sal.end < ecs->stop_func_end) |
| 5864 | ecs->stop_func_start = stop_func_sal.end; |
| 5865 | |
| 5866 | /* Architectures which require breakpoint adjustment might not be able |
| 5867 | to place a breakpoint at the computed address. If so, the test |
| 5868 | ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust |
| 5869 | ecs->stop_func_start to an address at which a breakpoint may be |
| 5870 | legitimately placed. |
| 5871 | |
| 5872 | Note: kevinb/2004-01-19: On FR-V, if this adjustment is not |
| 5873 | made, GDB will enter an infinite loop when stepping through |
| 5874 | optimized code consisting of VLIW instructions which contain |
| 5875 | subinstructions corresponding to different source lines. On |
| 5876 | FR-V, it's not permitted to place a breakpoint on any but the |
| 5877 | first subinstruction of a VLIW instruction. When a breakpoint is |
| 5878 | set, GDB will adjust the breakpoint address to the beginning of |
| 5879 | the VLIW instruction. Thus, we need to make the corresponding |
| 5880 | adjustment here when computing the stop address. */ |
| 5881 | |
| 5882 | if (gdbarch_adjust_breakpoint_address_p (gdbarch)) |
| 5883 | { |
| 5884 | ecs->stop_func_start |
| 5885 | = gdbarch_adjust_breakpoint_address (gdbarch, |
| 5886 | ecs->stop_func_start); |
| 5887 | } |
| 5888 | |
| 5889 | if (ecs->stop_func_start == stop_pc) |
| 5890 | { |
| 5891 | /* We are already there: stop now. */ |
| 5892 | end_stepping_range (ecs); |
| 5893 | return; |
| 5894 | } |
| 5895 | else |
| 5896 | { |
| 5897 | /* Put the step-breakpoint there and go until there. */ |
| 5898 | init_sal (&sr_sal); /* initialize to zeroes */ |
| 5899 | sr_sal.pc = ecs->stop_func_start; |
| 5900 | sr_sal.section = find_pc_overlay (ecs->stop_func_start); |
| 5901 | sr_sal.pspace = get_frame_program_space (get_current_frame ()); |
| 5902 | |
| 5903 | /* Do not specify what the fp should be when we stop since on |
| 5904 | some machines the prologue is where the new fp value is |
| 5905 | established. */ |
| 5906 | insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal, null_frame_id); |
| 5907 | |
| 5908 | /* And make sure stepping stops right away then. */ |
| 5909 | ecs->event_thread->control.step_range_end |
| 5910 | = ecs->event_thread->control.step_range_start; |
| 5911 | } |
| 5912 | keep_going (ecs); |
| 5913 | } |
| 5914 | |
| 5915 | /* Inferior has stepped backward into a subroutine call with source |
| 5916 | code that we should not step over. Do step to the beginning of the |
| 5917 | last line of code in it. */ |
| 5918 | |
| 5919 | static void |
| 5920 | handle_step_into_function_backward (struct gdbarch *gdbarch, |
| 5921 | struct execution_control_state *ecs) |
| 5922 | { |
| 5923 | struct compunit_symtab *cust; |
| 5924 | struct symtab_and_line stop_func_sal; |
| 5925 | |
| 5926 | fill_in_stop_func (gdbarch, ecs); |
| 5927 | |
| 5928 | cust = find_pc_compunit_symtab (stop_pc); |
| 5929 | if (cust != NULL && compunit_language (cust) != language_asm) |
| 5930 | ecs->stop_func_start = gdbarch_skip_prologue (gdbarch, |
| 5931 | ecs->stop_func_start); |
| 5932 | |
| 5933 | stop_func_sal = find_pc_line (stop_pc, 0); |
| 5934 | |
| 5935 | /* OK, we're just going to keep stepping here. */ |
| 5936 | if (stop_func_sal.pc == stop_pc) |
| 5937 | { |
| 5938 | /* We're there already. Just stop stepping now. */ |
| 5939 | end_stepping_range (ecs); |
| 5940 | } |
| 5941 | else |
| 5942 | { |
| 5943 | /* Else just reset the step range and keep going. |
| 5944 | No step-resume breakpoint, they don't work for |
| 5945 | epilogues, which can have multiple entry paths. */ |
| 5946 | ecs->event_thread->control.step_range_start = stop_func_sal.pc; |
| 5947 | ecs->event_thread->control.step_range_end = stop_func_sal.end; |
| 5948 | keep_going (ecs); |
| 5949 | } |
| 5950 | return; |
| 5951 | } |
| 5952 | |
| 5953 | /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID. |
| 5954 | This is used to both functions and to skip over code. */ |
| 5955 | |
| 5956 | static void |
| 5957 | insert_step_resume_breakpoint_at_sal_1 (struct gdbarch *gdbarch, |
| 5958 | struct symtab_and_line sr_sal, |
| 5959 | struct frame_id sr_id, |
| 5960 | enum bptype sr_type) |
| 5961 | { |
| 5962 | /* There should never be more than one step-resume or longjmp-resume |
| 5963 | breakpoint per thread, so we should never be setting a new |
| 5964 | step_resume_breakpoint when one is already active. */ |
| 5965 | gdb_assert (inferior_thread ()->control.step_resume_breakpoint == NULL); |
| 5966 | gdb_assert (sr_type == bp_step_resume || sr_type == bp_hp_step_resume); |
| 5967 | |
| 5968 | if (debug_infrun) |
| 5969 | fprintf_unfiltered (gdb_stdlog, |
| 5970 | "infrun: inserting step-resume breakpoint at %s\n", |
| 5971 | paddress (gdbarch, sr_sal.pc)); |
| 5972 | |
| 5973 | inferior_thread ()->control.step_resume_breakpoint |
| 5974 | = set_momentary_breakpoint (gdbarch, sr_sal, sr_id, sr_type); |
| 5975 | } |
| 5976 | |
| 5977 | void |
| 5978 | insert_step_resume_breakpoint_at_sal (struct gdbarch *gdbarch, |
| 5979 | struct symtab_and_line sr_sal, |
| 5980 | struct frame_id sr_id) |
| 5981 | { |
| 5982 | insert_step_resume_breakpoint_at_sal_1 (gdbarch, |
| 5983 | sr_sal, sr_id, |
| 5984 | bp_step_resume); |
| 5985 | } |
| 5986 | |
| 5987 | /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc. |
| 5988 | This is used to skip a potential signal handler. |
| 5989 | |
| 5990 | This is called with the interrupted function's frame. The signal |
| 5991 | handler, when it returns, will resume the interrupted function at |
| 5992 | RETURN_FRAME.pc. */ |
| 5993 | |
| 5994 | static void |
| 5995 | insert_hp_step_resume_breakpoint_at_frame (struct frame_info *return_frame) |
| 5996 | { |
| 5997 | struct symtab_and_line sr_sal; |
| 5998 | struct gdbarch *gdbarch; |
| 5999 | |
| 6000 | gdb_assert (return_frame != NULL); |
| 6001 | init_sal (&sr_sal); /* initialize to zeros */ |
| 6002 | |
| 6003 | gdbarch = get_frame_arch (return_frame); |
| 6004 | sr_sal.pc = gdbarch_addr_bits_remove (gdbarch, get_frame_pc (return_frame)); |
| 6005 | sr_sal.section = find_pc_overlay (sr_sal.pc); |
| 6006 | sr_sal.pspace = get_frame_program_space (return_frame); |
| 6007 | |
| 6008 | insert_step_resume_breakpoint_at_sal_1 (gdbarch, sr_sal, |
| 6009 | get_stack_frame_id (return_frame), |
| 6010 | bp_hp_step_resume); |
| 6011 | } |
| 6012 | |
| 6013 | /* Insert a "step-resume breakpoint" at the previous frame's PC. This |
| 6014 | is used to skip a function after stepping into it (for "next" or if |
| 6015 | the called function has no debugging information). |
| 6016 | |
| 6017 | The current function has almost always been reached by single |
| 6018 | stepping a call or return instruction. NEXT_FRAME belongs to the |
| 6019 | current function, and the breakpoint will be set at the caller's |
| 6020 | resume address. |
| 6021 | |
| 6022 | This is a separate function rather than reusing |
| 6023 | insert_hp_step_resume_breakpoint_at_frame in order to avoid |
| 6024 | get_prev_frame, which may stop prematurely (see the implementation |
| 6025 | of frame_unwind_caller_id for an example). */ |
| 6026 | |
| 6027 | static void |
| 6028 | insert_step_resume_breakpoint_at_caller (struct frame_info *next_frame) |
| 6029 | { |
| 6030 | struct symtab_and_line sr_sal; |
| 6031 | struct gdbarch *gdbarch; |
| 6032 | |
| 6033 | /* We shouldn't have gotten here if we don't know where the call site |
| 6034 | is. */ |
| 6035 | gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame))); |
| 6036 | |
| 6037 | init_sal (&sr_sal); /* initialize to zeros */ |
| 6038 | |
| 6039 | gdbarch = frame_unwind_caller_arch (next_frame); |
| 6040 | sr_sal.pc = gdbarch_addr_bits_remove (gdbarch, |
| 6041 | frame_unwind_caller_pc (next_frame)); |
| 6042 | sr_sal.section = find_pc_overlay (sr_sal.pc); |
| 6043 | sr_sal.pspace = frame_unwind_program_space (next_frame); |
| 6044 | |
| 6045 | insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal, |
| 6046 | frame_unwind_caller_id (next_frame)); |
| 6047 | } |
| 6048 | |
| 6049 | /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a |
| 6050 | new breakpoint at the target of a jmp_buf. The handling of |
| 6051 | longjmp-resume uses the same mechanisms used for handling |
| 6052 | "step-resume" breakpoints. */ |
| 6053 | |
| 6054 | static void |
| 6055 | insert_longjmp_resume_breakpoint (struct gdbarch *gdbarch, CORE_ADDR pc) |
| 6056 | { |
| 6057 | /* There should never be more than one longjmp-resume breakpoint per |
| 6058 | thread, so we should never be setting a new |
| 6059 | longjmp_resume_breakpoint when one is already active. */ |
| 6060 | gdb_assert (inferior_thread ()->control.exception_resume_breakpoint == NULL); |
| 6061 | |
| 6062 | if (debug_infrun) |
| 6063 | fprintf_unfiltered (gdb_stdlog, |
| 6064 | "infrun: inserting longjmp-resume breakpoint at %s\n", |
| 6065 | paddress (gdbarch, pc)); |
| 6066 | |
| 6067 | inferior_thread ()->control.exception_resume_breakpoint = |
| 6068 | set_momentary_breakpoint_at_pc (gdbarch, pc, bp_longjmp_resume); |
| 6069 | } |
| 6070 | |
| 6071 | /* Insert an exception resume breakpoint. TP is the thread throwing |
| 6072 | the exception. The block B is the block of the unwinder debug hook |
| 6073 | function. FRAME is the frame corresponding to the call to this |
| 6074 | function. SYM is the symbol of the function argument holding the |
| 6075 | target PC of the exception. */ |
| 6076 | |
| 6077 | static void |
| 6078 | insert_exception_resume_breakpoint (struct thread_info *tp, |
| 6079 | const struct block *b, |
| 6080 | struct frame_info *frame, |
| 6081 | struct symbol *sym) |
| 6082 | { |
| 6083 | TRY |
| 6084 | { |
| 6085 | struct symbol *vsym; |
| 6086 | struct value *value; |
| 6087 | CORE_ADDR handler; |
| 6088 | struct breakpoint *bp; |
| 6089 | |
| 6090 | vsym = lookup_symbol (SYMBOL_LINKAGE_NAME (sym), b, VAR_DOMAIN, NULL); |
| 6091 | value = read_var_value (vsym, frame); |
| 6092 | /* If the value was optimized out, revert to the old behavior. */ |
| 6093 | if (! value_optimized_out (value)) |
| 6094 | { |
| 6095 | handler = value_as_address (value); |
| 6096 | |
| 6097 | if (debug_infrun) |
| 6098 | fprintf_unfiltered (gdb_stdlog, |
| 6099 | "infrun: exception resume at %lx\n", |
| 6100 | (unsigned long) handler); |
| 6101 | |
| 6102 | bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame), |
| 6103 | handler, bp_exception_resume); |
| 6104 | |
| 6105 | /* set_momentary_breakpoint_at_pc invalidates FRAME. */ |
| 6106 | frame = NULL; |
| 6107 | |
| 6108 | bp->thread = tp->num; |
| 6109 | inferior_thread ()->control.exception_resume_breakpoint = bp; |
| 6110 | } |
| 6111 | } |
| 6112 | CATCH (e, RETURN_MASK_ERROR) |
| 6113 | { |
| 6114 | /* We want to ignore errors here. */ |
| 6115 | } |
| 6116 | END_CATCH |
| 6117 | } |
| 6118 | |
| 6119 | /* A helper for check_exception_resume that sets an |
| 6120 | exception-breakpoint based on a SystemTap probe. */ |
| 6121 | |
| 6122 | static void |
| 6123 | insert_exception_resume_from_probe (struct thread_info *tp, |
| 6124 | const struct bound_probe *probe, |
| 6125 | struct frame_info *frame) |
| 6126 | { |
| 6127 | struct value *arg_value; |
| 6128 | CORE_ADDR handler; |
| 6129 | struct breakpoint *bp; |
| 6130 | |
| 6131 | arg_value = probe_safe_evaluate_at_pc (frame, 1); |
| 6132 | if (!arg_value) |
| 6133 | return; |
| 6134 | |
| 6135 | handler = value_as_address (arg_value); |
| 6136 | |
| 6137 | if (debug_infrun) |
| 6138 | fprintf_unfiltered (gdb_stdlog, |
| 6139 | "infrun: exception resume at %s\n", |
| 6140 | paddress (get_objfile_arch (probe->objfile), |
| 6141 | handler)); |
| 6142 | |
| 6143 | bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame), |
| 6144 | handler, bp_exception_resume); |
| 6145 | bp->thread = tp->num; |
| 6146 | inferior_thread ()->control.exception_resume_breakpoint = bp; |
| 6147 | } |
| 6148 | |
| 6149 | /* This is called when an exception has been intercepted. Check to |
| 6150 | see whether the exception's destination is of interest, and if so, |
| 6151 | set an exception resume breakpoint there. */ |
| 6152 | |
| 6153 | static void |
| 6154 | check_exception_resume (struct execution_control_state *ecs, |
| 6155 | struct frame_info *frame) |
| 6156 | { |
| 6157 | struct bound_probe probe; |
| 6158 | struct symbol *func; |
| 6159 | |
| 6160 | /* First see if this exception unwinding breakpoint was set via a |
| 6161 | SystemTap probe point. If so, the probe has two arguments: the |
| 6162 | CFA and the HANDLER. We ignore the CFA, extract the handler, and |
| 6163 | set a breakpoint there. */ |
| 6164 | probe = find_probe_by_pc (get_frame_pc (frame)); |
| 6165 | if (probe.probe) |
| 6166 | { |
| 6167 | insert_exception_resume_from_probe (ecs->event_thread, &probe, frame); |
| 6168 | return; |
| 6169 | } |
| 6170 | |
| 6171 | func = get_frame_function (frame); |
| 6172 | if (!func) |
| 6173 | return; |
| 6174 | |
| 6175 | TRY |
| 6176 | { |
| 6177 | const struct block *b; |
| 6178 | struct block_iterator iter; |
| 6179 | struct symbol *sym; |
| 6180 | int argno = 0; |
| 6181 | |
| 6182 | /* The exception breakpoint is a thread-specific breakpoint on |
| 6183 | the unwinder's debug hook, declared as: |
| 6184 | |
| 6185 | void _Unwind_DebugHook (void *cfa, void *handler); |
| 6186 | |
| 6187 | The CFA argument indicates the frame to which control is |
| 6188 | about to be transferred. HANDLER is the destination PC. |
| 6189 | |
| 6190 | We ignore the CFA and set a temporary breakpoint at HANDLER. |
| 6191 | This is not extremely efficient but it avoids issues in gdb |
| 6192 | with computing the DWARF CFA, and it also works even in weird |
| 6193 | cases such as throwing an exception from inside a signal |
| 6194 | handler. */ |
| 6195 | |
| 6196 | b = SYMBOL_BLOCK_VALUE (func); |
| 6197 | ALL_BLOCK_SYMBOLS (b, iter, sym) |
| 6198 | { |
| 6199 | if (!SYMBOL_IS_ARGUMENT (sym)) |
| 6200 | continue; |
| 6201 | |
| 6202 | if (argno == 0) |
| 6203 | ++argno; |
| 6204 | else |
| 6205 | { |
| 6206 | insert_exception_resume_breakpoint (ecs->event_thread, |
| 6207 | b, frame, sym); |
| 6208 | break; |
| 6209 | } |
| 6210 | } |
| 6211 | } |
| 6212 | CATCH (e, RETURN_MASK_ERROR) |
| 6213 | { |
| 6214 | } |
| 6215 | END_CATCH |
| 6216 | } |
| 6217 | |
| 6218 | static void |
| 6219 | stop_waiting (struct execution_control_state *ecs) |
| 6220 | { |
| 6221 | if (debug_infrun) |
| 6222 | fprintf_unfiltered (gdb_stdlog, "infrun: stop_waiting\n"); |
| 6223 | |
| 6224 | clear_step_over_info (); |
| 6225 | |
| 6226 | /* Let callers know we don't want to wait for the inferior anymore. */ |
| 6227 | ecs->wait_some_more = 0; |
| 6228 | } |
| 6229 | |
| 6230 | /* Called when we should continue running the inferior, because the |
| 6231 | current event doesn't cause a user visible stop. This does the |
| 6232 | resuming part; waiting for the next event is done elsewhere. */ |
| 6233 | |
| 6234 | static void |
| 6235 | keep_going (struct execution_control_state *ecs) |
| 6236 | { |
| 6237 | /* Make sure normal_stop is called if we get a QUIT handled before |
| 6238 | reaching resume. */ |
| 6239 | struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0); |
| 6240 | |
| 6241 | /* Save the pc before execution, to compare with pc after stop. */ |
| 6242 | ecs->event_thread->prev_pc |
| 6243 | = regcache_read_pc (get_thread_regcache (ecs->ptid)); |
| 6244 | |
| 6245 | if (ecs->event_thread->control.trap_expected |
| 6246 | && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_TRAP) |
| 6247 | { |
| 6248 | /* We haven't yet gotten our trap, and either: intercepted a |
| 6249 | non-signal event (e.g., a fork); or took a signal which we |
| 6250 | are supposed to pass through to the inferior. Simply |
| 6251 | continue. */ |
| 6252 | discard_cleanups (old_cleanups); |
| 6253 | resume (ecs->event_thread->suspend.stop_signal); |
| 6254 | } |
| 6255 | else |
| 6256 | { |
| 6257 | struct regcache *regcache = get_current_regcache (); |
| 6258 | int remove_bp; |
| 6259 | int remove_wps; |
| 6260 | |
| 6261 | /* Either the trap was not expected, but we are continuing |
| 6262 | anyway (if we got a signal, the user asked it be passed to |
| 6263 | the child) |
| 6264 | -- or -- |
| 6265 | We got our expected trap, but decided we should resume from |
| 6266 | it. |
| 6267 | |
| 6268 | We're going to run this baby now! |
| 6269 | |
| 6270 | Note that insert_breakpoints won't try to re-insert |
| 6271 | already inserted breakpoints. Therefore, we don't |
| 6272 | care if breakpoints were already inserted, or not. */ |
| 6273 | |
| 6274 | /* If we need to step over a breakpoint, and we're not using |
| 6275 | displaced stepping to do so, insert all breakpoints |
| 6276 | (watchpoints, etc.) but the one we're stepping over, step one |
| 6277 | instruction, and then re-insert the breakpoint when that step |
| 6278 | is finished. */ |
| 6279 | |
| 6280 | remove_bp = (ecs->hit_singlestep_breakpoint |
| 6281 | || thread_still_needs_step_over (ecs->event_thread)); |
| 6282 | remove_wps = (ecs->event_thread->stepping_over_watchpoint |
| 6283 | && !target_have_steppable_watchpoint); |
| 6284 | |
| 6285 | /* We can't use displaced stepping if we need to step past a |
| 6286 | watchpoint. The instruction copied to the scratch pad would |
| 6287 | still trigger the watchpoint. */ |
| 6288 | if (remove_bp |
| 6289 | && (remove_wps |
| 6290 | || !use_displaced_stepping (get_regcache_arch (regcache)))) |
| 6291 | { |
| 6292 | set_step_over_info (get_regcache_aspace (regcache), |
| 6293 | regcache_read_pc (regcache), remove_wps); |
| 6294 | } |
| 6295 | else if (remove_wps) |
| 6296 | set_step_over_info (NULL, 0, remove_wps); |
| 6297 | else |
| 6298 | clear_step_over_info (); |
| 6299 | |
| 6300 | /* Stop stepping if inserting breakpoints fails. */ |
| 6301 | TRY |
| 6302 | { |
| 6303 | insert_breakpoints (); |
| 6304 | } |
| 6305 | CATCH (e, RETURN_MASK_ERROR) |
| 6306 | { |
| 6307 | exception_print (gdb_stderr, e); |
| 6308 | stop_waiting (ecs); |
| 6309 | discard_cleanups (old_cleanups); |
| 6310 | return; |
| 6311 | } |
| 6312 | END_CATCH |
| 6313 | |
| 6314 | ecs->event_thread->control.trap_expected = (remove_bp || remove_wps); |
| 6315 | |
| 6316 | /* Do not deliver GDB_SIGNAL_TRAP (except when the user |
| 6317 | explicitly specifies that such a signal should be delivered |
| 6318 | to the target program). Typically, that would occur when a |
| 6319 | user is debugging a target monitor on a simulator: the target |
| 6320 | monitor sets a breakpoint; the simulator encounters this |
| 6321 | breakpoint and halts the simulation handing control to GDB; |
| 6322 | GDB, noting that the stop address doesn't map to any known |
| 6323 | breakpoint, returns control back to the simulator; the |
| 6324 | simulator then delivers the hardware equivalent of a |
| 6325 | GDB_SIGNAL_TRAP to the program being debugged. */ |
| 6326 | if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP |
| 6327 | && !signal_program[ecs->event_thread->suspend.stop_signal]) |
| 6328 | ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0; |
| 6329 | |
| 6330 | discard_cleanups (old_cleanups); |
| 6331 | resume (ecs->event_thread->suspend.stop_signal); |
| 6332 | } |
| 6333 | |
| 6334 | prepare_to_wait (ecs); |
| 6335 | } |
| 6336 | |
| 6337 | /* This function normally comes after a resume, before |
| 6338 | handle_inferior_event exits. It takes care of any last bits of |
| 6339 | housekeeping, and sets the all-important wait_some_more flag. */ |
| 6340 | |
| 6341 | static void |
| 6342 | prepare_to_wait (struct execution_control_state *ecs) |
| 6343 | { |
| 6344 | if (debug_infrun) |
| 6345 | fprintf_unfiltered (gdb_stdlog, "infrun: prepare_to_wait\n"); |
| 6346 | |
| 6347 | /* This is the old end of the while loop. Let everybody know we |
| 6348 | want to wait for the inferior some more and get called again |
| 6349 | soon. */ |
| 6350 | ecs->wait_some_more = 1; |
| 6351 | } |
| 6352 | |
| 6353 | /* We are done with the step range of a step/next/si/ni command. |
| 6354 | Called once for each n of a "step n" operation. */ |
| 6355 | |
| 6356 | static void |
| 6357 | end_stepping_range (struct execution_control_state *ecs) |
| 6358 | { |
| 6359 | ecs->event_thread->control.stop_step = 1; |
| 6360 | stop_waiting (ecs); |
| 6361 | } |
| 6362 | |
| 6363 | /* Several print_*_reason functions to print why the inferior has stopped. |
| 6364 | We always print something when the inferior exits, or receives a signal. |
| 6365 | The rest of the cases are dealt with later on in normal_stop and |
| 6366 | print_it_typical. Ideally there should be a call to one of these |
| 6367 | print_*_reason functions functions from handle_inferior_event each time |
| 6368 | stop_waiting is called. |
| 6369 | |
| 6370 | Note that we don't call these directly, instead we delegate that to |
| 6371 | the interpreters, through observers. Interpreters then call these |
| 6372 | with whatever uiout is right. */ |
| 6373 | |
| 6374 | void |
| 6375 | print_end_stepping_range_reason (struct ui_out *uiout) |
| 6376 | { |
| 6377 | /* For CLI-like interpreters, print nothing. */ |
| 6378 | |
| 6379 | if (ui_out_is_mi_like_p (uiout)) |
| 6380 | { |
| 6381 | ui_out_field_string (uiout, "reason", |
| 6382 | async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE)); |
| 6383 | } |
| 6384 | } |
| 6385 | |
| 6386 | void |
| 6387 | print_signal_exited_reason (struct ui_out *uiout, enum gdb_signal siggnal) |
| 6388 | { |
| 6389 | annotate_signalled (); |
| 6390 | if (ui_out_is_mi_like_p (uiout)) |
| 6391 | ui_out_field_string |
| 6392 | (uiout, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED)); |
| 6393 | ui_out_text (uiout, "\nProgram terminated with signal "); |
| 6394 | annotate_signal_name (); |
| 6395 | ui_out_field_string (uiout, "signal-name", |
| 6396 | gdb_signal_to_name (siggnal)); |
| 6397 | annotate_signal_name_end (); |
| 6398 | ui_out_text (uiout, ", "); |
| 6399 | annotate_signal_string (); |
| 6400 | ui_out_field_string (uiout, "signal-meaning", |
| 6401 | gdb_signal_to_string (siggnal)); |
| 6402 | annotate_signal_string_end (); |
| 6403 | ui_out_text (uiout, ".\n"); |
| 6404 | ui_out_text (uiout, "The program no longer exists.\n"); |
| 6405 | } |
| 6406 | |
| 6407 | void |
| 6408 | print_exited_reason (struct ui_out *uiout, int exitstatus) |
| 6409 | { |
| 6410 | struct inferior *inf = current_inferior (); |
| 6411 | const char *pidstr = target_pid_to_str (pid_to_ptid (inf->pid)); |
| 6412 | |
| 6413 | annotate_exited (exitstatus); |
| 6414 | if (exitstatus) |
| 6415 | { |
| 6416 | if (ui_out_is_mi_like_p (uiout)) |
| 6417 | ui_out_field_string (uiout, "reason", |
| 6418 | async_reason_lookup (EXEC_ASYNC_EXITED)); |
| 6419 | ui_out_text (uiout, "[Inferior "); |
| 6420 | ui_out_text (uiout, plongest (inf->num)); |
| 6421 | ui_out_text (uiout, " ("); |
| 6422 | ui_out_text (uiout, pidstr); |
| 6423 | ui_out_text (uiout, ") exited with code "); |
| 6424 | ui_out_field_fmt (uiout, "exit-code", "0%o", (unsigned int) exitstatus); |
| 6425 | ui_out_text (uiout, "]\n"); |
| 6426 | } |
| 6427 | else |
| 6428 | { |
| 6429 | if (ui_out_is_mi_like_p (uiout)) |
| 6430 | ui_out_field_string |
| 6431 | (uiout, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY)); |
| 6432 | ui_out_text (uiout, "[Inferior "); |
| 6433 | ui_out_text (uiout, plongest (inf->num)); |
| 6434 | ui_out_text (uiout, " ("); |
| 6435 | ui_out_text (uiout, pidstr); |
| 6436 | ui_out_text (uiout, ") exited normally]\n"); |
| 6437 | } |
| 6438 | } |
| 6439 | |
| 6440 | void |
| 6441 | print_signal_received_reason (struct ui_out *uiout, enum gdb_signal siggnal) |
| 6442 | { |
| 6443 | annotate_signal (); |
| 6444 | |
| 6445 | if (siggnal == GDB_SIGNAL_0 && !ui_out_is_mi_like_p (uiout)) |
| 6446 | { |
| 6447 | struct thread_info *t = inferior_thread (); |
| 6448 | |
| 6449 | ui_out_text (uiout, "\n["); |
| 6450 | ui_out_field_string (uiout, "thread-name", |
| 6451 | target_pid_to_str (t->ptid)); |
| 6452 | ui_out_field_fmt (uiout, "thread-id", "] #%d", t->num); |
| 6453 | ui_out_text (uiout, " stopped"); |
| 6454 | } |
| 6455 | else |
| 6456 | { |
| 6457 | ui_out_text (uiout, "\nProgram received signal "); |
| 6458 | annotate_signal_name (); |
| 6459 | if (ui_out_is_mi_like_p (uiout)) |
| 6460 | ui_out_field_string |
| 6461 | (uiout, "reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED)); |
| 6462 | ui_out_field_string (uiout, "signal-name", |
| 6463 | gdb_signal_to_name (siggnal)); |
| 6464 | annotate_signal_name_end (); |
| 6465 | ui_out_text (uiout, ", "); |
| 6466 | annotate_signal_string (); |
| 6467 | ui_out_field_string (uiout, "signal-meaning", |
| 6468 | gdb_signal_to_string (siggnal)); |
| 6469 | annotate_signal_string_end (); |
| 6470 | } |
| 6471 | ui_out_text (uiout, ".\n"); |
| 6472 | } |
| 6473 | |
| 6474 | void |
| 6475 | print_no_history_reason (struct ui_out *uiout) |
| 6476 | { |
| 6477 | ui_out_text (uiout, "\nNo more reverse-execution history.\n"); |
| 6478 | } |
| 6479 | |
| 6480 | /* Print current location without a level number, if we have changed |
| 6481 | functions or hit a breakpoint. Print source line if we have one. |
| 6482 | bpstat_print contains the logic deciding in detail what to print, |
| 6483 | based on the event(s) that just occurred. */ |
| 6484 | |
| 6485 | void |
| 6486 | print_stop_event (struct target_waitstatus *ws) |
| 6487 | { |
| 6488 | int bpstat_ret; |
| 6489 | int source_flag; |
| 6490 | int do_frame_printing = 1; |
| 6491 | struct thread_info *tp = inferior_thread (); |
| 6492 | |
| 6493 | bpstat_ret = bpstat_print (tp->control.stop_bpstat, ws->kind); |
| 6494 | switch (bpstat_ret) |
| 6495 | { |
| 6496 | case PRINT_UNKNOWN: |
| 6497 | /* FIXME: cagney/2002-12-01: Given that a frame ID does (or |
| 6498 | should) carry around the function and does (or should) use |
| 6499 | that when doing a frame comparison. */ |
| 6500 | if (tp->control.stop_step |
| 6501 | && frame_id_eq (tp->control.step_frame_id, |
| 6502 | get_frame_id (get_current_frame ())) |
| 6503 | && tp->control.step_start_function == find_pc_function (stop_pc)) |
| 6504 | { |
| 6505 | /* Finished step, just print source line. */ |
| 6506 | source_flag = SRC_LINE; |
| 6507 | } |
| 6508 | else |
| 6509 | { |
| 6510 | /* Print location and source line. */ |
| 6511 | source_flag = SRC_AND_LOC; |
| 6512 | } |
| 6513 | break; |
| 6514 | case PRINT_SRC_AND_LOC: |
| 6515 | /* Print location and source line. */ |
| 6516 | source_flag = SRC_AND_LOC; |
| 6517 | break; |
| 6518 | case PRINT_SRC_ONLY: |
| 6519 | source_flag = SRC_LINE; |
| 6520 | break; |
| 6521 | case PRINT_NOTHING: |
| 6522 | /* Something bogus. */ |
| 6523 | source_flag = SRC_LINE; |
| 6524 | do_frame_printing = 0; |
| 6525 | break; |
| 6526 | default: |
| 6527 | internal_error (__FILE__, __LINE__, _("Unknown value.")); |
| 6528 | } |
| 6529 | |
| 6530 | /* The behavior of this routine with respect to the source |
| 6531 | flag is: |
| 6532 | SRC_LINE: Print only source line |
| 6533 | LOCATION: Print only location |
| 6534 | SRC_AND_LOC: Print location and source line. */ |
| 6535 | if (do_frame_printing) |
| 6536 | print_stack_frame (get_selected_frame (NULL), 0, source_flag, 1); |
| 6537 | |
| 6538 | /* Display the auto-display expressions. */ |
| 6539 | do_displays (); |
| 6540 | } |
| 6541 | |
| 6542 | /* Here to return control to GDB when the inferior stops for real. |
| 6543 | Print appropriate messages, remove breakpoints, give terminal our modes. |
| 6544 | |
| 6545 | STOP_PRINT_FRAME nonzero means print the executing frame |
| 6546 | (pc, function, args, file, line number and line text). |
| 6547 | BREAKPOINTS_FAILED nonzero means stop was due to error |
| 6548 | attempting to insert breakpoints. */ |
| 6549 | |
| 6550 | void |
| 6551 | normal_stop (void) |
| 6552 | { |
| 6553 | struct target_waitstatus last; |
| 6554 | ptid_t last_ptid; |
| 6555 | struct cleanup *old_chain = make_cleanup (null_cleanup, NULL); |
| 6556 | |
| 6557 | get_last_target_status (&last_ptid, &last); |
| 6558 | |
| 6559 | /* If an exception is thrown from this point on, make sure to |
| 6560 | propagate GDB's knowledge of the executing state to the |
| 6561 | frontend/user running state. A QUIT is an easy exception to see |
| 6562 | here, so do this before any filtered output. */ |
| 6563 | if (!non_stop) |
| 6564 | make_cleanup (finish_thread_state_cleanup, &minus_one_ptid); |
| 6565 | else if (last.kind != TARGET_WAITKIND_SIGNALLED |
| 6566 | && last.kind != TARGET_WAITKIND_EXITED |
| 6567 | && last.kind != TARGET_WAITKIND_NO_RESUMED) |
| 6568 | make_cleanup (finish_thread_state_cleanup, &inferior_ptid); |
| 6569 | |
| 6570 | /* As we're presenting a stop, and potentially removing breakpoints, |
| 6571 | update the thread list so we can tell whether there are threads |
| 6572 | running on the target. With target remote, for example, we can |
| 6573 | only learn about new threads when we explicitly update the thread |
| 6574 | list. Do this before notifying the interpreters about signal |
| 6575 | stops, end of stepping ranges, etc., so that the "new thread" |
| 6576 | output is emitted before e.g., "Program received signal FOO", |
| 6577 | instead of after. */ |
| 6578 | update_thread_list (); |
| 6579 | |
| 6580 | if (last.kind == TARGET_WAITKIND_STOPPED && stopped_by_random_signal) |
| 6581 | observer_notify_signal_received (inferior_thread ()->suspend.stop_signal); |
| 6582 | |
| 6583 | /* As with the notification of thread events, we want to delay |
| 6584 | notifying the user that we've switched thread context until |
| 6585 | the inferior actually stops. |
| 6586 | |
| 6587 | There's no point in saying anything if the inferior has exited. |
| 6588 | Note that SIGNALLED here means "exited with a signal", not |
| 6589 | "received a signal". |
| 6590 | |
| 6591 | Also skip saying anything in non-stop mode. In that mode, as we |
| 6592 | don't want GDB to switch threads behind the user's back, to avoid |
| 6593 | races where the user is typing a command to apply to thread x, |
| 6594 | but GDB switches to thread y before the user finishes entering |
| 6595 | the command, fetch_inferior_event installs a cleanup to restore |
| 6596 | the current thread back to the thread the user had selected right |
| 6597 | after this event is handled, so we're not really switching, only |
| 6598 | informing of a stop. */ |
| 6599 | if (!non_stop |
| 6600 | && !ptid_equal (previous_inferior_ptid, inferior_ptid) |
| 6601 | && target_has_execution |
| 6602 | && last.kind != TARGET_WAITKIND_SIGNALLED |
| 6603 | && last.kind != TARGET_WAITKIND_EXITED |
| 6604 | && last.kind != TARGET_WAITKIND_NO_RESUMED) |
| 6605 | { |
| 6606 | target_terminal_ours_for_output (); |
| 6607 | printf_filtered (_("[Switching to %s]\n"), |
| 6608 | target_pid_to_str (inferior_ptid)); |
| 6609 | annotate_thread_changed (); |
| 6610 | previous_inferior_ptid = inferior_ptid; |
| 6611 | } |
| 6612 | |
| 6613 | if (last.kind == TARGET_WAITKIND_NO_RESUMED) |
| 6614 | { |
| 6615 | gdb_assert (sync_execution || !target_can_async_p ()); |
| 6616 | |
| 6617 | target_terminal_ours_for_output (); |
| 6618 | printf_filtered (_("No unwaited-for children left.\n")); |
| 6619 | } |
| 6620 | |
| 6621 | /* Note: this depends on the update_thread_list call above. */ |
| 6622 | if (!breakpoints_should_be_inserted_now () && target_has_execution) |
| 6623 | { |
| 6624 | if (remove_breakpoints ()) |
| 6625 | { |
| 6626 | target_terminal_ours_for_output (); |
| 6627 | printf_filtered (_("Cannot remove breakpoints because " |
| 6628 | "program is no longer writable.\nFurther " |
| 6629 | "execution is probably impossible.\n")); |
| 6630 | } |
| 6631 | } |
| 6632 | |
| 6633 | /* If an auto-display called a function and that got a signal, |
| 6634 | delete that auto-display to avoid an infinite recursion. */ |
| 6635 | |
| 6636 | if (stopped_by_random_signal) |
| 6637 | disable_current_display (); |
| 6638 | |
| 6639 | /* Notify observers if we finished a "step"-like command, etc. */ |
| 6640 | if (target_has_execution |
| 6641 | && last.kind != TARGET_WAITKIND_SIGNALLED |
| 6642 | && last.kind != TARGET_WAITKIND_EXITED |
| 6643 | && inferior_thread ()->control.stop_step) |
| 6644 | { |
| 6645 | /* But not if in the middle of doing a "step n" operation for |
| 6646 | n > 1 */ |
| 6647 | if (inferior_thread ()->step_multi) |
| 6648 | goto done; |
| 6649 | |
| 6650 | observer_notify_end_stepping_range (); |
| 6651 | } |
| 6652 | |
| 6653 | target_terminal_ours (); |
| 6654 | async_enable_stdin (); |
| 6655 | |
| 6656 | /* Set the current source location. This will also happen if we |
| 6657 | display the frame below, but the current SAL will be incorrect |
| 6658 | during a user hook-stop function. */ |
| 6659 | if (has_stack_frames () && !stop_stack_dummy) |
| 6660 | set_current_sal_from_frame (get_current_frame ()); |
| 6661 | |
| 6662 | /* Let the user/frontend see the threads as stopped, but defer to |
| 6663 | call_function_by_hand if the thread finished an infcall |
| 6664 | successfully. We may be e.g., evaluating a breakpoint condition. |
| 6665 | In that case, the thread had state THREAD_RUNNING before the |
| 6666 | infcall, and shall remain marked running, all without informing |
| 6667 | the user/frontend about state transition changes. */ |
| 6668 | if (target_has_execution |
| 6669 | && inferior_thread ()->control.in_infcall |
| 6670 | && stop_stack_dummy == STOP_STACK_DUMMY) |
| 6671 | discard_cleanups (old_chain); |
| 6672 | else |
| 6673 | do_cleanups (old_chain); |
| 6674 | |
| 6675 | /* Look up the hook_stop and run it (CLI internally handles problem |
| 6676 | of stop_command's pre-hook not existing). */ |
| 6677 | if (stop_command) |
| 6678 | catch_errors (hook_stop_stub, stop_command, |
| 6679 | "Error while running hook_stop:\n", RETURN_MASK_ALL); |
| 6680 | |
| 6681 | if (!has_stack_frames ()) |
| 6682 | goto done; |
| 6683 | |
| 6684 | if (last.kind == TARGET_WAITKIND_SIGNALLED |
| 6685 | || last.kind == TARGET_WAITKIND_EXITED) |
| 6686 | goto done; |
| 6687 | |
| 6688 | /* Select innermost stack frame - i.e., current frame is frame 0, |
| 6689 | and current location is based on that. |
| 6690 | Don't do this on return from a stack dummy routine, |
| 6691 | or if the program has exited. */ |
| 6692 | |
| 6693 | if (!stop_stack_dummy) |
| 6694 | { |
| 6695 | select_frame (get_current_frame ()); |
| 6696 | |
| 6697 | /* If --batch-silent is enabled then there's no need to print the current |
| 6698 | source location, and to try risks causing an error message about |
| 6699 | missing source files. */ |
| 6700 | if (stop_print_frame && !batch_silent) |
| 6701 | print_stop_event (&last); |
| 6702 | } |
| 6703 | |
| 6704 | if (stop_stack_dummy == STOP_STACK_DUMMY) |
| 6705 | { |
| 6706 | /* Pop the empty frame that contains the stack dummy. |
| 6707 | This also restores inferior state prior to the call |
| 6708 | (struct infcall_suspend_state). */ |
| 6709 | struct frame_info *frame = get_current_frame (); |
| 6710 | |
| 6711 | gdb_assert (get_frame_type (frame) == DUMMY_FRAME); |
| 6712 | frame_pop (frame); |
| 6713 | /* frame_pop() calls reinit_frame_cache as the last thing it |
| 6714 | does which means there's currently no selected frame. We |
| 6715 | don't need to re-establish a selected frame if the dummy call |
| 6716 | returns normally, that will be done by |
| 6717 | restore_infcall_control_state. However, we do have to handle |
| 6718 | the case where the dummy call is returning after being |
| 6719 | stopped (e.g. the dummy call previously hit a breakpoint). |
| 6720 | We can't know which case we have so just always re-establish |
| 6721 | a selected frame here. */ |
| 6722 | select_frame (get_current_frame ()); |
| 6723 | } |
| 6724 | |
| 6725 | done: |
| 6726 | annotate_stopped (); |
| 6727 | |
| 6728 | /* Suppress the stop observer if we're in the middle of: |
| 6729 | |
| 6730 | - a step n (n > 1), as there still more steps to be done. |
| 6731 | |
| 6732 | - a "finish" command, as the observer will be called in |
| 6733 | finish_command_continuation, so it can include the inferior |
| 6734 | function's return value. |
| 6735 | |
| 6736 | - calling an inferior function, as we pretend we inferior didn't |
| 6737 | run at all. The return value of the call is handled by the |
| 6738 | expression evaluator, through call_function_by_hand. */ |
| 6739 | |
| 6740 | if (!target_has_execution |
| 6741 | || last.kind == TARGET_WAITKIND_SIGNALLED |
| 6742 | || last.kind == TARGET_WAITKIND_EXITED |
| 6743 | || last.kind == TARGET_WAITKIND_NO_RESUMED |
| 6744 | || (!(inferior_thread ()->step_multi |
| 6745 | && inferior_thread ()->control.stop_step) |
| 6746 | && !(inferior_thread ()->control.stop_bpstat |
| 6747 | && inferior_thread ()->control.proceed_to_finish) |
| 6748 | && !inferior_thread ()->control.in_infcall)) |
| 6749 | { |
| 6750 | if (!ptid_equal (inferior_ptid, null_ptid)) |
| 6751 | observer_notify_normal_stop (inferior_thread ()->control.stop_bpstat, |
| 6752 | stop_print_frame); |
| 6753 | else |
| 6754 | observer_notify_normal_stop (NULL, stop_print_frame); |
| 6755 | } |
| 6756 | |
| 6757 | if (target_has_execution) |
| 6758 | { |
| 6759 | if (last.kind != TARGET_WAITKIND_SIGNALLED |
| 6760 | && last.kind != TARGET_WAITKIND_EXITED) |
| 6761 | /* Delete the breakpoint we stopped at, if it wants to be deleted. |
| 6762 | Delete any breakpoint that is to be deleted at the next stop. */ |
| 6763 | breakpoint_auto_delete (inferior_thread ()->control.stop_bpstat); |
| 6764 | } |
| 6765 | |
| 6766 | /* Try to get rid of automatically added inferiors that are no |
| 6767 | longer needed. Keeping those around slows down things linearly. |
| 6768 | Note that this never removes the current inferior. */ |
| 6769 | prune_inferiors (); |
| 6770 | } |
| 6771 | |
| 6772 | static int |
| 6773 | hook_stop_stub (void *cmd) |
| 6774 | { |
| 6775 | execute_cmd_pre_hook ((struct cmd_list_element *) cmd); |
| 6776 | return (0); |
| 6777 | } |
| 6778 | \f |
| 6779 | int |
| 6780 | signal_stop_state (int signo) |
| 6781 | { |
| 6782 | return signal_stop[signo]; |
| 6783 | } |
| 6784 | |
| 6785 | int |
| 6786 | signal_print_state (int signo) |
| 6787 | { |
| 6788 | return signal_print[signo]; |
| 6789 | } |
| 6790 | |
| 6791 | int |
| 6792 | signal_pass_state (int signo) |
| 6793 | { |
| 6794 | return signal_program[signo]; |
| 6795 | } |
| 6796 | |
| 6797 | static void |
| 6798 | signal_cache_update (int signo) |
| 6799 | { |
| 6800 | if (signo == -1) |
| 6801 | { |
| 6802 | for (signo = 0; signo < (int) GDB_SIGNAL_LAST; signo++) |
| 6803 | signal_cache_update (signo); |
| 6804 | |
| 6805 | return; |
| 6806 | } |
| 6807 | |
| 6808 | signal_pass[signo] = (signal_stop[signo] == 0 |
| 6809 | && signal_print[signo] == 0 |
| 6810 | && signal_program[signo] == 1 |
| 6811 | && signal_catch[signo] == 0); |
| 6812 | } |
| 6813 | |
| 6814 | int |
| 6815 | signal_stop_update (int signo, int state) |
| 6816 | { |
| 6817 | int ret = signal_stop[signo]; |
| 6818 | |
| 6819 | signal_stop[signo] = state; |
| 6820 | signal_cache_update (signo); |
| 6821 | return ret; |
| 6822 | } |
| 6823 | |
| 6824 | int |
| 6825 | signal_print_update (int signo, int state) |
| 6826 | { |
| 6827 | int ret = signal_print[signo]; |
| 6828 | |
| 6829 | signal_print[signo] = state; |
| 6830 | signal_cache_update (signo); |
| 6831 | return ret; |
| 6832 | } |
| 6833 | |
| 6834 | int |
| 6835 | signal_pass_update (int signo, int state) |
| 6836 | { |
| 6837 | int ret = signal_program[signo]; |
| 6838 | |
| 6839 | signal_program[signo] = state; |
| 6840 | signal_cache_update (signo); |
| 6841 | return ret; |
| 6842 | } |
| 6843 | |
| 6844 | /* Update the global 'signal_catch' from INFO and notify the |
| 6845 | target. */ |
| 6846 | |
| 6847 | void |
| 6848 | signal_catch_update (const unsigned int *info) |
| 6849 | { |
| 6850 | int i; |
| 6851 | |
| 6852 | for (i = 0; i < GDB_SIGNAL_LAST; ++i) |
| 6853 | signal_catch[i] = info[i] > 0; |
| 6854 | signal_cache_update (-1); |
| 6855 | target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass); |
| 6856 | } |
| 6857 | |
| 6858 | static void |
| 6859 | sig_print_header (void) |
| 6860 | { |
| 6861 | printf_filtered (_("Signal Stop\tPrint\tPass " |
| 6862 | "to program\tDescription\n")); |
| 6863 | } |
| 6864 | |
| 6865 | static void |
| 6866 | sig_print_info (enum gdb_signal oursig) |
| 6867 | { |
| 6868 | const char *name = gdb_signal_to_name (oursig); |
| 6869 | int name_padding = 13 - strlen (name); |
| 6870 | |
| 6871 | if (name_padding <= 0) |
| 6872 | name_padding = 0; |
| 6873 | |
| 6874 | printf_filtered ("%s", name); |
| 6875 | printf_filtered ("%*.*s ", name_padding, name_padding, " "); |
| 6876 | printf_filtered ("%s\t", signal_stop[oursig] ? "Yes" : "No"); |
| 6877 | printf_filtered ("%s\t", signal_print[oursig] ? "Yes" : "No"); |
| 6878 | printf_filtered ("%s\t\t", signal_program[oursig] ? "Yes" : "No"); |
| 6879 | printf_filtered ("%s\n", gdb_signal_to_string (oursig)); |
| 6880 | } |
| 6881 | |
| 6882 | /* Specify how various signals in the inferior should be handled. */ |
| 6883 | |
| 6884 | static void |
| 6885 | handle_command (char *args, int from_tty) |
| 6886 | { |
| 6887 | char **argv; |
| 6888 | int digits, wordlen; |
| 6889 | int sigfirst, signum, siglast; |
| 6890 | enum gdb_signal oursig; |
| 6891 | int allsigs; |
| 6892 | int nsigs; |
| 6893 | unsigned char *sigs; |
| 6894 | struct cleanup *old_chain; |
| 6895 | |
| 6896 | if (args == NULL) |
| 6897 | { |
| 6898 | error_no_arg (_("signal to handle")); |
| 6899 | } |
| 6900 | |
| 6901 | /* Allocate and zero an array of flags for which signals to handle. */ |
| 6902 | |
| 6903 | nsigs = (int) GDB_SIGNAL_LAST; |
| 6904 | sigs = (unsigned char *) alloca (nsigs); |
| 6905 | memset (sigs, 0, nsigs); |
| 6906 | |
| 6907 | /* Break the command line up into args. */ |
| 6908 | |
| 6909 | argv = gdb_buildargv (args); |
| 6910 | old_chain = make_cleanup_freeargv (argv); |
| 6911 | |
| 6912 | /* Walk through the args, looking for signal oursigs, signal names, and |
| 6913 | actions. Signal numbers and signal names may be interspersed with |
| 6914 | actions, with the actions being performed for all signals cumulatively |
| 6915 | specified. Signal ranges can be specified as <LOW>-<HIGH>. */ |
| 6916 | |
| 6917 | while (*argv != NULL) |
| 6918 | { |
| 6919 | wordlen = strlen (*argv); |
| 6920 | for (digits = 0; isdigit ((*argv)[digits]); digits++) |
| 6921 | {; |
| 6922 | } |
| 6923 | allsigs = 0; |
| 6924 | sigfirst = siglast = -1; |
| 6925 | |
| 6926 | if (wordlen >= 1 && !strncmp (*argv, "all", wordlen)) |
| 6927 | { |
| 6928 | /* Apply action to all signals except those used by the |
| 6929 | debugger. Silently skip those. */ |
| 6930 | allsigs = 1; |
| 6931 | sigfirst = 0; |
| 6932 | siglast = nsigs - 1; |
| 6933 | } |
| 6934 | else if (wordlen >= 1 && !strncmp (*argv, "stop", wordlen)) |
| 6935 | { |
| 6936 | SET_SIGS (nsigs, sigs, signal_stop); |
| 6937 | SET_SIGS (nsigs, sigs, signal_print); |
| 6938 | } |
| 6939 | else if (wordlen >= 1 && !strncmp (*argv, "ignore", wordlen)) |
| 6940 | { |
| 6941 | UNSET_SIGS (nsigs, sigs, signal_program); |
| 6942 | } |
| 6943 | else if (wordlen >= 2 && !strncmp (*argv, "print", wordlen)) |
| 6944 | { |
| 6945 | SET_SIGS (nsigs, sigs, signal_print); |
| 6946 | } |
| 6947 | else if (wordlen >= 2 && !strncmp (*argv, "pass", wordlen)) |
| 6948 | { |
| 6949 | SET_SIGS (nsigs, sigs, signal_program); |
| 6950 | } |
| 6951 | else if (wordlen >= 3 && !strncmp (*argv, "nostop", wordlen)) |
| 6952 | { |
| 6953 | UNSET_SIGS (nsigs, sigs, signal_stop); |
| 6954 | } |
| 6955 | else if (wordlen >= 3 && !strncmp (*argv, "noignore", wordlen)) |
| 6956 | { |
| 6957 | SET_SIGS (nsigs, sigs, signal_program); |
| 6958 | } |
| 6959 | else if (wordlen >= 4 && !strncmp (*argv, "noprint", wordlen)) |
| 6960 | { |
| 6961 | UNSET_SIGS (nsigs, sigs, signal_print); |
| 6962 | UNSET_SIGS (nsigs, sigs, signal_stop); |
| 6963 | } |
| 6964 | else if (wordlen >= 4 && !strncmp (*argv, "nopass", wordlen)) |
| 6965 | { |
| 6966 | UNSET_SIGS (nsigs, sigs, signal_program); |
| 6967 | } |
| 6968 | else if (digits > 0) |
| 6969 | { |
| 6970 | /* It is numeric. The numeric signal refers to our own |
| 6971 | internal signal numbering from target.h, not to host/target |
| 6972 | signal number. This is a feature; users really should be |
| 6973 | using symbolic names anyway, and the common ones like |
| 6974 | SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */ |
| 6975 | |
| 6976 | sigfirst = siglast = (int) |
| 6977 | gdb_signal_from_command (atoi (*argv)); |
| 6978 | if ((*argv)[digits] == '-') |
| 6979 | { |
| 6980 | siglast = (int) |
| 6981 | gdb_signal_from_command (atoi ((*argv) + digits + 1)); |
| 6982 | } |
| 6983 | if (sigfirst > siglast) |
| 6984 | { |
| 6985 | /* Bet he didn't figure we'd think of this case... */ |
| 6986 | signum = sigfirst; |
| 6987 | sigfirst = siglast; |
| 6988 | siglast = signum; |
| 6989 | } |
| 6990 | } |
| 6991 | else |
| 6992 | { |
| 6993 | oursig = gdb_signal_from_name (*argv); |
| 6994 | if (oursig != GDB_SIGNAL_UNKNOWN) |
| 6995 | { |
| 6996 | sigfirst = siglast = (int) oursig; |
| 6997 | } |
| 6998 | else |
| 6999 | { |
| 7000 | /* Not a number and not a recognized flag word => complain. */ |
| 7001 | error (_("Unrecognized or ambiguous flag word: \"%s\"."), *argv); |
| 7002 | } |
| 7003 | } |
| 7004 | |
| 7005 | /* If any signal numbers or symbol names were found, set flags for |
| 7006 | which signals to apply actions to. */ |
| 7007 | |
| 7008 | for (signum = sigfirst; signum >= 0 && signum <= siglast; signum++) |
| 7009 | { |
| 7010 | switch ((enum gdb_signal) signum) |
| 7011 | { |
| 7012 | case GDB_SIGNAL_TRAP: |
| 7013 | case GDB_SIGNAL_INT: |
| 7014 | if (!allsigs && !sigs[signum]) |
| 7015 | { |
| 7016 | if (query (_("%s is used by the debugger.\n\ |
| 7017 | Are you sure you want to change it? "), |
| 7018 | gdb_signal_to_name ((enum gdb_signal) signum))) |
| 7019 | { |
| 7020 | sigs[signum] = 1; |
| 7021 | } |
| 7022 | else |
| 7023 | { |
| 7024 | printf_unfiltered (_("Not confirmed, unchanged.\n")); |
| 7025 | gdb_flush (gdb_stdout); |
| 7026 | } |
| 7027 | } |
| 7028 | break; |
| 7029 | case GDB_SIGNAL_0: |
| 7030 | case GDB_SIGNAL_DEFAULT: |
| 7031 | case GDB_SIGNAL_UNKNOWN: |
| 7032 | /* Make sure that "all" doesn't print these. */ |
| 7033 | break; |
| 7034 | default: |
| 7035 | sigs[signum] = 1; |
| 7036 | break; |
| 7037 | } |
| 7038 | } |
| 7039 | |
| 7040 | argv++; |
| 7041 | } |
| 7042 | |
| 7043 | for (signum = 0; signum < nsigs; signum++) |
| 7044 | if (sigs[signum]) |
| 7045 | { |
| 7046 | signal_cache_update (-1); |
| 7047 | target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass); |
| 7048 | target_program_signals ((int) GDB_SIGNAL_LAST, signal_program); |
| 7049 | |
| 7050 | if (from_tty) |
| 7051 | { |
| 7052 | /* Show the results. */ |
| 7053 | sig_print_header (); |
| 7054 | for (; signum < nsigs; signum++) |
| 7055 | if (sigs[signum]) |
| 7056 | sig_print_info (signum); |
| 7057 | } |
| 7058 | |
| 7059 | break; |
| 7060 | } |
| 7061 | |
| 7062 | do_cleanups (old_chain); |
| 7063 | } |
| 7064 | |
| 7065 | /* Complete the "handle" command. */ |
| 7066 | |
| 7067 | static VEC (char_ptr) * |
| 7068 | handle_completer (struct cmd_list_element *ignore, |
| 7069 | const char *text, const char *word) |
| 7070 | { |
| 7071 | VEC (char_ptr) *vec_signals, *vec_keywords, *return_val; |
| 7072 | static const char * const keywords[] = |
| 7073 | { |
| 7074 | "all", |
| 7075 | "stop", |
| 7076 | "ignore", |
| 7077 | "print", |
| 7078 | "pass", |
| 7079 | "nostop", |
| 7080 | "noignore", |
| 7081 | "noprint", |
| 7082 | "nopass", |
| 7083 | NULL, |
| 7084 | }; |
| 7085 | |
| 7086 | vec_signals = signal_completer (ignore, text, word); |
| 7087 | vec_keywords = complete_on_enum (keywords, word, word); |
| 7088 | |
| 7089 | return_val = VEC_merge (char_ptr, vec_signals, vec_keywords); |
| 7090 | VEC_free (char_ptr, vec_signals); |
| 7091 | VEC_free (char_ptr, vec_keywords); |
| 7092 | return return_val; |
| 7093 | } |
| 7094 | |
| 7095 | enum gdb_signal |
| 7096 | gdb_signal_from_command (int num) |
| 7097 | { |
| 7098 | if (num >= 1 && num <= 15) |
| 7099 | return (enum gdb_signal) num; |
| 7100 | error (_("Only signals 1-15 are valid as numeric signals.\n\ |
| 7101 | Use \"info signals\" for a list of symbolic signals.")); |
| 7102 | } |
| 7103 | |
| 7104 | /* Print current contents of the tables set by the handle command. |
| 7105 | It is possible we should just be printing signals actually used |
| 7106 | by the current target (but for things to work right when switching |
| 7107 | targets, all signals should be in the signal tables). */ |
| 7108 | |
| 7109 | static void |
| 7110 | signals_info (char *signum_exp, int from_tty) |
| 7111 | { |
| 7112 | enum gdb_signal oursig; |
| 7113 | |
| 7114 | sig_print_header (); |
| 7115 | |
| 7116 | if (signum_exp) |
| 7117 | { |
| 7118 | /* First see if this is a symbol name. */ |
| 7119 | oursig = gdb_signal_from_name (signum_exp); |
| 7120 | if (oursig == GDB_SIGNAL_UNKNOWN) |
| 7121 | { |
| 7122 | /* No, try numeric. */ |
| 7123 | oursig = |
| 7124 | gdb_signal_from_command (parse_and_eval_long (signum_exp)); |
| 7125 | } |
| 7126 | sig_print_info (oursig); |
| 7127 | return; |
| 7128 | } |
| 7129 | |
| 7130 | printf_filtered ("\n"); |
| 7131 | /* These ugly casts brought to you by the native VAX compiler. */ |
| 7132 | for (oursig = GDB_SIGNAL_FIRST; |
| 7133 | (int) oursig < (int) GDB_SIGNAL_LAST; |
| 7134 | oursig = (enum gdb_signal) ((int) oursig + 1)) |
| 7135 | { |
| 7136 | QUIT; |
| 7137 | |
| 7138 | if (oursig != GDB_SIGNAL_UNKNOWN |
| 7139 | && oursig != GDB_SIGNAL_DEFAULT && oursig != GDB_SIGNAL_0) |
| 7140 | sig_print_info (oursig); |
| 7141 | } |
| 7142 | |
| 7143 | printf_filtered (_("\nUse the \"handle\" command " |
| 7144 | "to change these tables.\n")); |
| 7145 | } |
| 7146 | |
| 7147 | /* Check if it makes sense to read $_siginfo from the current thread |
| 7148 | at this point. If not, throw an error. */ |
| 7149 | |
| 7150 | static void |
| 7151 | validate_siginfo_access (void) |
| 7152 | { |
| 7153 | /* No current inferior, no siginfo. */ |
| 7154 | if (ptid_equal (inferior_ptid, null_ptid)) |
| 7155 | error (_("No thread selected.")); |
| 7156 | |
| 7157 | /* Don't try to read from a dead thread. */ |
| 7158 | if (is_exited (inferior_ptid)) |
| 7159 | error (_("The current thread has terminated")); |
| 7160 | |
| 7161 | /* ... or from a spinning thread. */ |
| 7162 | if (is_running (inferior_ptid)) |
| 7163 | error (_("Selected thread is running.")); |
| 7164 | } |
| 7165 | |
| 7166 | /* The $_siginfo convenience variable is a bit special. We don't know |
| 7167 | for sure the type of the value until we actually have a chance to |
| 7168 | fetch the data. The type can change depending on gdbarch, so it is |
| 7169 | also dependent on which thread you have selected. |
| 7170 | |
| 7171 | 1. making $_siginfo be an internalvar that creates a new value on |
| 7172 | access. |
| 7173 | |
| 7174 | 2. making the value of $_siginfo be an lval_computed value. */ |
| 7175 | |
| 7176 | /* This function implements the lval_computed support for reading a |
| 7177 | $_siginfo value. */ |
| 7178 | |
| 7179 | static void |
| 7180 | siginfo_value_read (struct value *v) |
| 7181 | { |
| 7182 | LONGEST transferred; |
| 7183 | |
| 7184 | validate_siginfo_access (); |
| 7185 | |
| 7186 | transferred = |
| 7187 | target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO, |
| 7188 | NULL, |
| 7189 | value_contents_all_raw (v), |
| 7190 | value_offset (v), |
| 7191 | TYPE_LENGTH (value_type (v))); |
| 7192 | |
| 7193 | if (transferred != TYPE_LENGTH (value_type (v))) |
| 7194 | error (_("Unable to read siginfo")); |
| 7195 | } |
| 7196 | |
| 7197 | /* This function implements the lval_computed support for writing a |
| 7198 | $_siginfo value. */ |
| 7199 | |
| 7200 | static void |
| 7201 | siginfo_value_write (struct value *v, struct value *fromval) |
| 7202 | { |
| 7203 | LONGEST transferred; |
| 7204 | |
| 7205 | validate_siginfo_access (); |
| 7206 | |
| 7207 | transferred = target_write (¤t_target, |
| 7208 | TARGET_OBJECT_SIGNAL_INFO, |
| 7209 | NULL, |
| 7210 | value_contents_all_raw (fromval), |
| 7211 | value_offset (v), |
| 7212 | TYPE_LENGTH (value_type (fromval))); |
| 7213 | |
| 7214 | if (transferred != TYPE_LENGTH (value_type (fromval))) |
| 7215 | error (_("Unable to write siginfo")); |
| 7216 | } |
| 7217 | |
| 7218 | static const struct lval_funcs siginfo_value_funcs = |
| 7219 | { |
| 7220 | siginfo_value_read, |
| 7221 | siginfo_value_write |
| 7222 | }; |
| 7223 | |
| 7224 | /* Return a new value with the correct type for the siginfo object of |
| 7225 | the current thread using architecture GDBARCH. Return a void value |
| 7226 | if there's no object available. */ |
| 7227 | |
| 7228 | static struct value * |
| 7229 | siginfo_make_value (struct gdbarch *gdbarch, struct internalvar *var, |
| 7230 | void *ignore) |
| 7231 | { |
| 7232 | if (target_has_stack |
| 7233 | && !ptid_equal (inferior_ptid, null_ptid) |
| 7234 | && gdbarch_get_siginfo_type_p (gdbarch)) |
| 7235 | { |
| 7236 | struct type *type = gdbarch_get_siginfo_type (gdbarch); |
| 7237 | |
| 7238 | return allocate_computed_value (type, &siginfo_value_funcs, NULL); |
| 7239 | } |
| 7240 | |
| 7241 | return allocate_value (builtin_type (gdbarch)->builtin_void); |
| 7242 | } |
| 7243 | |
| 7244 | \f |
| 7245 | /* infcall_suspend_state contains state about the program itself like its |
| 7246 | registers and any signal it received when it last stopped. |
| 7247 | This state must be restored regardless of how the inferior function call |
| 7248 | ends (either successfully, or after it hits a breakpoint or signal) |
| 7249 | if the program is to properly continue where it left off. */ |
| 7250 | |
| 7251 | struct infcall_suspend_state |
| 7252 | { |
| 7253 | struct thread_suspend_state thread_suspend; |
| 7254 | |
| 7255 | /* Other fields: */ |
| 7256 | CORE_ADDR stop_pc; |
| 7257 | struct regcache *registers; |
| 7258 | |
| 7259 | /* Format of SIGINFO_DATA or NULL if it is not present. */ |
| 7260 | struct gdbarch *siginfo_gdbarch; |
| 7261 | |
| 7262 | /* The inferior format depends on SIGINFO_GDBARCH and it has a length of |
| 7263 | TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the |
| 7264 | content would be invalid. */ |
| 7265 | gdb_byte *siginfo_data; |
| 7266 | }; |
| 7267 | |
| 7268 | struct infcall_suspend_state * |
| 7269 | save_infcall_suspend_state (void) |
| 7270 | { |
| 7271 | struct infcall_suspend_state *inf_state; |
| 7272 | struct thread_info *tp = inferior_thread (); |
| 7273 | struct regcache *regcache = get_current_regcache (); |
| 7274 | struct gdbarch *gdbarch = get_regcache_arch (regcache); |
| 7275 | gdb_byte *siginfo_data = NULL; |
| 7276 | |
| 7277 | if (gdbarch_get_siginfo_type_p (gdbarch)) |
| 7278 | { |
| 7279 | struct type *type = gdbarch_get_siginfo_type (gdbarch); |
| 7280 | size_t len = TYPE_LENGTH (type); |
| 7281 | struct cleanup *back_to; |
| 7282 | |
| 7283 | siginfo_data = xmalloc (len); |
| 7284 | back_to = make_cleanup (xfree, siginfo_data); |
| 7285 | |
| 7286 | if (target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL, |
| 7287 | siginfo_data, 0, len) == len) |
| 7288 | discard_cleanups (back_to); |
| 7289 | else |
| 7290 | { |
| 7291 | /* Errors ignored. */ |
| 7292 | do_cleanups (back_to); |
| 7293 | siginfo_data = NULL; |
| 7294 | } |
| 7295 | } |
| 7296 | |
| 7297 | inf_state = XCNEW (struct infcall_suspend_state); |
| 7298 | |
| 7299 | if (siginfo_data) |
| 7300 | { |
| 7301 | inf_state->siginfo_gdbarch = gdbarch; |
| 7302 | inf_state->siginfo_data = siginfo_data; |
| 7303 | } |
| 7304 | |
| 7305 | inf_state->thread_suspend = tp->suspend; |
| 7306 | |
| 7307 | /* run_inferior_call will not use the signal due to its `proceed' call with |
| 7308 | GDB_SIGNAL_0 anyway. */ |
| 7309 | tp->suspend.stop_signal = GDB_SIGNAL_0; |
| 7310 | |
| 7311 | inf_state->stop_pc = stop_pc; |
| 7312 | |
| 7313 | inf_state->registers = regcache_dup (regcache); |
| 7314 | |
| 7315 | return inf_state; |
| 7316 | } |
| 7317 | |
| 7318 | /* Restore inferior session state to INF_STATE. */ |
| 7319 | |
| 7320 | void |
| 7321 | restore_infcall_suspend_state (struct infcall_suspend_state *inf_state) |
| 7322 | { |
| 7323 | struct thread_info *tp = inferior_thread (); |
| 7324 | struct regcache *regcache = get_current_regcache (); |
| 7325 | struct gdbarch *gdbarch = get_regcache_arch (regcache); |
| 7326 | |
| 7327 | tp->suspend = inf_state->thread_suspend; |
| 7328 | |
| 7329 | stop_pc = inf_state->stop_pc; |
| 7330 | |
| 7331 | if (inf_state->siginfo_gdbarch == gdbarch) |
| 7332 | { |
| 7333 | struct type *type = gdbarch_get_siginfo_type (gdbarch); |
| 7334 | |
| 7335 | /* Errors ignored. */ |
| 7336 | target_write (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL, |
| 7337 | inf_state->siginfo_data, 0, TYPE_LENGTH (type)); |
| 7338 | } |
| 7339 | |
| 7340 | /* The inferior can be gone if the user types "print exit(0)" |
| 7341 | (and perhaps other times). */ |
| 7342 | if (target_has_execution) |
| 7343 | /* NB: The register write goes through to the target. */ |
| 7344 | regcache_cpy (regcache, inf_state->registers); |
| 7345 | |
| 7346 | discard_infcall_suspend_state (inf_state); |
| 7347 | } |
| 7348 | |
| 7349 | static void |
| 7350 | do_restore_infcall_suspend_state_cleanup (void *state) |
| 7351 | { |
| 7352 | restore_infcall_suspend_state (state); |
| 7353 | } |
| 7354 | |
| 7355 | struct cleanup * |
| 7356 | make_cleanup_restore_infcall_suspend_state |
| 7357 | (struct infcall_suspend_state *inf_state) |
| 7358 | { |
| 7359 | return make_cleanup (do_restore_infcall_suspend_state_cleanup, inf_state); |
| 7360 | } |
| 7361 | |
| 7362 | void |
| 7363 | discard_infcall_suspend_state (struct infcall_suspend_state *inf_state) |
| 7364 | { |
| 7365 | regcache_xfree (inf_state->registers); |
| 7366 | xfree (inf_state->siginfo_data); |
| 7367 | xfree (inf_state); |
| 7368 | } |
| 7369 | |
| 7370 | struct regcache * |
| 7371 | get_infcall_suspend_state_regcache (struct infcall_suspend_state *inf_state) |
| 7372 | { |
| 7373 | return inf_state->registers; |
| 7374 | } |
| 7375 | |
| 7376 | /* infcall_control_state contains state regarding gdb's control of the |
| 7377 | inferior itself like stepping control. It also contains session state like |
| 7378 | the user's currently selected frame. */ |
| 7379 | |
| 7380 | struct infcall_control_state |
| 7381 | { |
| 7382 | struct thread_control_state thread_control; |
| 7383 | struct inferior_control_state inferior_control; |
| 7384 | |
| 7385 | /* Other fields: */ |
| 7386 | enum stop_stack_kind stop_stack_dummy; |
| 7387 | int stopped_by_random_signal; |
| 7388 | int stop_after_trap; |
| 7389 | |
| 7390 | /* ID if the selected frame when the inferior function call was made. */ |
| 7391 | struct frame_id selected_frame_id; |
| 7392 | }; |
| 7393 | |
| 7394 | /* Save all of the information associated with the inferior<==>gdb |
| 7395 | connection. */ |
| 7396 | |
| 7397 | struct infcall_control_state * |
| 7398 | save_infcall_control_state (void) |
| 7399 | { |
| 7400 | struct infcall_control_state *inf_status = xmalloc (sizeof (*inf_status)); |
| 7401 | struct thread_info *tp = inferior_thread (); |
| 7402 | struct inferior *inf = current_inferior (); |
| 7403 | |
| 7404 | inf_status->thread_control = tp->control; |
| 7405 | inf_status->inferior_control = inf->control; |
| 7406 | |
| 7407 | tp->control.step_resume_breakpoint = NULL; |
| 7408 | tp->control.exception_resume_breakpoint = NULL; |
| 7409 | |
| 7410 | /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of |
| 7411 | chain. If caller's caller is walking the chain, they'll be happier if we |
| 7412 | hand them back the original chain when restore_infcall_control_state is |
| 7413 | called. */ |
| 7414 | tp->control.stop_bpstat = bpstat_copy (tp->control.stop_bpstat); |
| 7415 | |
| 7416 | /* Other fields: */ |
| 7417 | inf_status->stop_stack_dummy = stop_stack_dummy; |
| 7418 | inf_status->stopped_by_random_signal = stopped_by_random_signal; |
| 7419 | inf_status->stop_after_trap = stop_after_trap; |
| 7420 | |
| 7421 | inf_status->selected_frame_id = get_frame_id (get_selected_frame (NULL)); |
| 7422 | |
| 7423 | return inf_status; |
| 7424 | } |
| 7425 | |
| 7426 | static int |
| 7427 | restore_selected_frame (void *args) |
| 7428 | { |
| 7429 | struct frame_id *fid = (struct frame_id *) args; |
| 7430 | struct frame_info *frame; |
| 7431 | |
| 7432 | frame = frame_find_by_id (*fid); |
| 7433 | |
| 7434 | /* If inf_status->selected_frame_id is NULL, there was no previously |
| 7435 | selected frame. */ |
| 7436 | if (frame == NULL) |
| 7437 | { |
| 7438 | warning (_("Unable to restore previously selected frame.")); |
| 7439 | return 0; |
| 7440 | } |
| 7441 | |
| 7442 | select_frame (frame); |
| 7443 | |
| 7444 | return (1); |
| 7445 | } |
| 7446 | |
| 7447 | /* Restore inferior session state to INF_STATUS. */ |
| 7448 | |
| 7449 | void |
| 7450 | restore_infcall_control_state (struct infcall_control_state *inf_status) |
| 7451 | { |
| 7452 | struct thread_info *tp = inferior_thread (); |
| 7453 | struct inferior *inf = current_inferior (); |
| 7454 | |
| 7455 | if (tp->control.step_resume_breakpoint) |
| 7456 | tp->control.step_resume_breakpoint->disposition = disp_del_at_next_stop; |
| 7457 | |
| 7458 | if (tp->control.exception_resume_breakpoint) |
| 7459 | tp->control.exception_resume_breakpoint->disposition |
| 7460 | = disp_del_at_next_stop; |
| 7461 | |
| 7462 | /* Handle the bpstat_copy of the chain. */ |
| 7463 | bpstat_clear (&tp->control.stop_bpstat); |
| 7464 | |
| 7465 | tp->control = inf_status->thread_control; |
| 7466 | inf->control = inf_status->inferior_control; |
| 7467 | |
| 7468 | /* Other fields: */ |
| 7469 | stop_stack_dummy = inf_status->stop_stack_dummy; |
| 7470 | stopped_by_random_signal = inf_status->stopped_by_random_signal; |
| 7471 | stop_after_trap = inf_status->stop_after_trap; |
| 7472 | |
| 7473 | if (target_has_stack) |
| 7474 | { |
| 7475 | /* The point of catch_errors is that if the stack is clobbered, |
| 7476 | walking the stack might encounter a garbage pointer and |
| 7477 | error() trying to dereference it. */ |
| 7478 | if (catch_errors |
| 7479 | (restore_selected_frame, &inf_status->selected_frame_id, |
| 7480 | "Unable to restore previously selected frame:\n", |
| 7481 | RETURN_MASK_ERROR) == 0) |
| 7482 | /* Error in restoring the selected frame. Select the innermost |
| 7483 | frame. */ |
| 7484 | select_frame (get_current_frame ()); |
| 7485 | } |
| 7486 | |
| 7487 | xfree (inf_status); |
| 7488 | } |
| 7489 | |
| 7490 | static void |
| 7491 | do_restore_infcall_control_state_cleanup (void *sts) |
| 7492 | { |
| 7493 | restore_infcall_control_state (sts); |
| 7494 | } |
| 7495 | |
| 7496 | struct cleanup * |
| 7497 | make_cleanup_restore_infcall_control_state |
| 7498 | (struct infcall_control_state *inf_status) |
| 7499 | { |
| 7500 | return make_cleanup (do_restore_infcall_control_state_cleanup, inf_status); |
| 7501 | } |
| 7502 | |
| 7503 | void |
| 7504 | discard_infcall_control_state (struct infcall_control_state *inf_status) |
| 7505 | { |
| 7506 | if (inf_status->thread_control.step_resume_breakpoint) |
| 7507 | inf_status->thread_control.step_resume_breakpoint->disposition |
| 7508 | = disp_del_at_next_stop; |
| 7509 | |
| 7510 | if (inf_status->thread_control.exception_resume_breakpoint) |
| 7511 | inf_status->thread_control.exception_resume_breakpoint->disposition |
| 7512 | = disp_del_at_next_stop; |
| 7513 | |
| 7514 | /* See save_infcall_control_state for info on stop_bpstat. */ |
| 7515 | bpstat_clear (&inf_status->thread_control.stop_bpstat); |
| 7516 | |
| 7517 | xfree (inf_status); |
| 7518 | } |
| 7519 | \f |
| 7520 | /* restore_inferior_ptid() will be used by the cleanup machinery |
| 7521 | to restore the inferior_ptid value saved in a call to |
| 7522 | save_inferior_ptid(). */ |
| 7523 | |
| 7524 | static void |
| 7525 | restore_inferior_ptid (void *arg) |
| 7526 | { |
| 7527 | ptid_t *saved_ptid_ptr = arg; |
| 7528 | |
| 7529 | inferior_ptid = *saved_ptid_ptr; |
| 7530 | xfree (arg); |
| 7531 | } |
| 7532 | |
| 7533 | /* Save the value of inferior_ptid so that it may be restored by a |
| 7534 | later call to do_cleanups(). Returns the struct cleanup pointer |
| 7535 | needed for later doing the cleanup. */ |
| 7536 | |
| 7537 | struct cleanup * |
| 7538 | save_inferior_ptid (void) |
| 7539 | { |
| 7540 | ptid_t *saved_ptid_ptr; |
| 7541 | |
| 7542 | saved_ptid_ptr = xmalloc (sizeof (ptid_t)); |
| 7543 | *saved_ptid_ptr = inferior_ptid; |
| 7544 | return make_cleanup (restore_inferior_ptid, saved_ptid_ptr); |
| 7545 | } |
| 7546 | |
| 7547 | /* See infrun.h. */ |
| 7548 | |
| 7549 | void |
| 7550 | clear_exit_convenience_vars (void) |
| 7551 | { |
| 7552 | clear_internalvar (lookup_internalvar ("_exitsignal")); |
| 7553 | clear_internalvar (lookup_internalvar ("_exitcode")); |
| 7554 | } |
| 7555 | \f |
| 7556 | |
| 7557 | /* User interface for reverse debugging: |
| 7558 | Set exec-direction / show exec-direction commands |
| 7559 | (returns error unless target implements to_set_exec_direction method). */ |
| 7560 | |
| 7561 | int execution_direction = EXEC_FORWARD; |
| 7562 | static const char exec_forward[] = "forward"; |
| 7563 | static const char exec_reverse[] = "reverse"; |
| 7564 | static const char *exec_direction = exec_forward; |
| 7565 | static const char *const exec_direction_names[] = { |
| 7566 | exec_forward, |
| 7567 | exec_reverse, |
| 7568 | NULL |
| 7569 | }; |
| 7570 | |
| 7571 | static void |
| 7572 | set_exec_direction_func (char *args, int from_tty, |
| 7573 | struct cmd_list_element *cmd) |
| 7574 | { |
| 7575 | if (target_can_execute_reverse) |
| 7576 | { |
| 7577 | if (!strcmp (exec_direction, exec_forward)) |
| 7578 | execution_direction = EXEC_FORWARD; |
| 7579 | else if (!strcmp (exec_direction, exec_reverse)) |
| 7580 | execution_direction = EXEC_REVERSE; |
| 7581 | } |
| 7582 | else |
| 7583 | { |
| 7584 | exec_direction = exec_forward; |
| 7585 | error (_("Target does not support this operation.")); |
| 7586 | } |
| 7587 | } |
| 7588 | |
| 7589 | static void |
| 7590 | show_exec_direction_func (struct ui_file *out, int from_tty, |
| 7591 | struct cmd_list_element *cmd, const char *value) |
| 7592 | { |
| 7593 | switch (execution_direction) { |
| 7594 | case EXEC_FORWARD: |
| 7595 | fprintf_filtered (out, _("Forward.\n")); |
| 7596 | break; |
| 7597 | case EXEC_REVERSE: |
| 7598 | fprintf_filtered (out, _("Reverse.\n")); |
| 7599 | break; |
| 7600 | default: |
| 7601 | internal_error (__FILE__, __LINE__, |
| 7602 | _("bogus execution_direction value: %d"), |
| 7603 | (int) execution_direction); |
| 7604 | } |
| 7605 | } |
| 7606 | |
| 7607 | static void |
| 7608 | show_schedule_multiple (struct ui_file *file, int from_tty, |
| 7609 | struct cmd_list_element *c, const char *value) |
| 7610 | { |
| 7611 | fprintf_filtered (file, _("Resuming the execution of threads " |
| 7612 | "of all processes is %s.\n"), value); |
| 7613 | } |
| 7614 | |
| 7615 | /* Implementation of `siginfo' variable. */ |
| 7616 | |
| 7617 | static const struct internalvar_funcs siginfo_funcs = |
| 7618 | { |
| 7619 | siginfo_make_value, |
| 7620 | NULL, |
| 7621 | NULL |
| 7622 | }; |
| 7623 | |
| 7624 | void |
| 7625 | _initialize_infrun (void) |
| 7626 | { |
| 7627 | int i; |
| 7628 | int numsigs; |
| 7629 | struct cmd_list_element *c; |
| 7630 | |
| 7631 | add_info ("signals", signals_info, _("\ |
| 7632 | What debugger does when program gets various signals.\n\ |
| 7633 | Specify a signal as argument to print info on that signal only.")); |
| 7634 | add_info_alias ("handle", "signals", 0); |
| 7635 | |
| 7636 | c = add_com ("handle", class_run, handle_command, _("\ |
| 7637 | Specify how to handle signals.\n\ |
| 7638 | Usage: handle SIGNAL [ACTIONS]\n\ |
| 7639 | Args are signals and actions to apply to those signals.\n\ |
| 7640 | If no actions are specified, the current settings for the specified signals\n\ |
| 7641 | will be displayed instead.\n\ |
| 7642 | \n\ |
| 7643 | Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\ |
| 7644 | from 1-15 are allowed for compatibility with old versions of GDB.\n\ |
| 7645 | Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\ |
| 7646 | The special arg \"all\" is recognized to mean all signals except those\n\ |
| 7647 | used by the debugger, typically SIGTRAP and SIGINT.\n\ |
| 7648 | \n\ |
| 7649 | Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\ |
| 7650 | \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\ |
| 7651 | Stop means reenter debugger if this signal happens (implies print).\n\ |
| 7652 | Print means print a message if this signal happens.\n\ |
| 7653 | Pass means let program see this signal; otherwise program doesn't know.\n\ |
| 7654 | Ignore is a synonym for nopass and noignore is a synonym for pass.\n\ |
| 7655 | Pass and Stop may be combined.\n\ |
| 7656 | \n\ |
| 7657 | Multiple signals may be specified. Signal numbers and signal names\n\ |
| 7658 | may be interspersed with actions, with the actions being performed for\n\ |
| 7659 | all signals cumulatively specified.")); |
| 7660 | set_cmd_completer (c, handle_completer); |
| 7661 | |
| 7662 | if (!dbx_commands) |
| 7663 | stop_command = add_cmd ("stop", class_obscure, |
| 7664 | not_just_help_class_command, _("\ |
| 7665 | There is no `stop' command, but you can set a hook on `stop'.\n\ |
| 7666 | This allows you to set a list of commands to be run each time execution\n\ |
| 7667 | of the program stops."), &cmdlist); |
| 7668 | |
| 7669 | add_setshow_zuinteger_cmd ("infrun", class_maintenance, &debug_infrun, _("\ |
| 7670 | Set inferior debugging."), _("\ |
| 7671 | Show inferior debugging."), _("\ |
| 7672 | When non-zero, inferior specific debugging is enabled."), |
| 7673 | NULL, |
| 7674 | show_debug_infrun, |
| 7675 | &setdebuglist, &showdebuglist); |
| 7676 | |
| 7677 | add_setshow_boolean_cmd ("displaced", class_maintenance, |
| 7678 | &debug_displaced, _("\ |
| 7679 | Set displaced stepping debugging."), _("\ |
| 7680 | Show displaced stepping debugging."), _("\ |
| 7681 | When non-zero, displaced stepping specific debugging is enabled."), |
| 7682 | NULL, |
| 7683 | show_debug_displaced, |
| 7684 | &setdebuglist, &showdebuglist); |
| 7685 | |
| 7686 | add_setshow_boolean_cmd ("non-stop", no_class, |
| 7687 | &non_stop_1, _("\ |
| 7688 | Set whether gdb controls the inferior in non-stop mode."), _("\ |
| 7689 | Show whether gdb controls the inferior in non-stop mode."), _("\ |
| 7690 | When debugging a multi-threaded program and this setting is\n\ |
| 7691 | off (the default, also called all-stop mode), when one thread stops\n\ |
| 7692 | (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\ |
| 7693 | all other threads in the program while you interact with the thread of\n\ |
| 7694 | interest. When you continue or step a thread, you can allow the other\n\ |
| 7695 | threads to run, or have them remain stopped, but while you inspect any\n\ |
| 7696 | thread's state, all threads stop.\n\ |
| 7697 | \n\ |
| 7698 | In non-stop mode, when one thread stops, other threads can continue\n\ |
| 7699 | to run freely. You'll be able to step each thread independently,\n\ |
| 7700 | leave it stopped or free to run as needed."), |
| 7701 | set_non_stop, |
| 7702 | show_non_stop, |
| 7703 | &setlist, |
| 7704 | &showlist); |
| 7705 | |
| 7706 | numsigs = (int) GDB_SIGNAL_LAST; |
| 7707 | signal_stop = (unsigned char *) xmalloc (sizeof (signal_stop[0]) * numsigs); |
| 7708 | signal_print = (unsigned char *) |
| 7709 | xmalloc (sizeof (signal_print[0]) * numsigs); |
| 7710 | signal_program = (unsigned char *) |
| 7711 | xmalloc (sizeof (signal_program[0]) * numsigs); |
| 7712 | signal_catch = (unsigned char *) |
| 7713 | xmalloc (sizeof (signal_catch[0]) * numsigs); |
| 7714 | signal_pass = (unsigned char *) |
| 7715 | xmalloc (sizeof (signal_pass[0]) * numsigs); |
| 7716 | for (i = 0; i < numsigs; i++) |
| 7717 | { |
| 7718 | signal_stop[i] = 1; |
| 7719 | signal_print[i] = 1; |
| 7720 | signal_program[i] = 1; |
| 7721 | signal_catch[i] = 0; |
| 7722 | } |
| 7723 | |
| 7724 | /* Signals caused by debugger's own actions |
| 7725 | should not be given to the program afterwards. */ |
| 7726 | signal_program[GDB_SIGNAL_TRAP] = 0; |
| 7727 | signal_program[GDB_SIGNAL_INT] = 0; |
| 7728 | |
| 7729 | /* Signals that are not errors should not normally enter the debugger. */ |
| 7730 | signal_stop[GDB_SIGNAL_ALRM] = 0; |
| 7731 | signal_print[GDB_SIGNAL_ALRM] = 0; |
| 7732 | signal_stop[GDB_SIGNAL_VTALRM] = 0; |
| 7733 | signal_print[GDB_SIGNAL_VTALRM] = 0; |
| 7734 | signal_stop[GDB_SIGNAL_PROF] = 0; |
| 7735 | signal_print[GDB_SIGNAL_PROF] = 0; |
| 7736 | signal_stop[GDB_SIGNAL_CHLD] = 0; |
| 7737 | signal_print[GDB_SIGNAL_CHLD] = 0; |
| 7738 | signal_stop[GDB_SIGNAL_IO] = 0; |
| 7739 | signal_print[GDB_SIGNAL_IO] = 0; |
| 7740 | signal_stop[GDB_SIGNAL_POLL] = 0; |
| 7741 | signal_print[GDB_SIGNAL_POLL] = 0; |
| 7742 | signal_stop[GDB_SIGNAL_URG] = 0; |
| 7743 | signal_print[GDB_SIGNAL_URG] = 0; |
| 7744 | signal_stop[GDB_SIGNAL_WINCH] = 0; |
| 7745 | signal_print[GDB_SIGNAL_WINCH] = 0; |
| 7746 | signal_stop[GDB_SIGNAL_PRIO] = 0; |
| 7747 | signal_print[GDB_SIGNAL_PRIO] = 0; |
| 7748 | |
| 7749 | /* These signals are used internally by user-level thread |
| 7750 | implementations. (See signal(5) on Solaris.) Like the above |
| 7751 | signals, a healthy program receives and handles them as part of |
| 7752 | its normal operation. */ |
| 7753 | signal_stop[GDB_SIGNAL_LWP] = 0; |
| 7754 | signal_print[GDB_SIGNAL_LWP] = 0; |
| 7755 | signal_stop[GDB_SIGNAL_WAITING] = 0; |
| 7756 | signal_print[GDB_SIGNAL_WAITING] = 0; |
| 7757 | signal_stop[GDB_SIGNAL_CANCEL] = 0; |
| 7758 | signal_print[GDB_SIGNAL_CANCEL] = 0; |
| 7759 | |
| 7760 | /* Update cached state. */ |
| 7761 | signal_cache_update (-1); |
| 7762 | |
| 7763 | add_setshow_zinteger_cmd ("stop-on-solib-events", class_support, |
| 7764 | &stop_on_solib_events, _("\ |
| 7765 | Set stopping for shared library events."), _("\ |
| 7766 | Show stopping for shared library events."), _("\ |
| 7767 | If nonzero, gdb will give control to the user when the dynamic linker\n\ |
| 7768 | notifies gdb of shared library events. The most common event of interest\n\ |
| 7769 | to the user would be loading/unloading of a new library."), |
| 7770 | set_stop_on_solib_events, |
| 7771 | show_stop_on_solib_events, |
| 7772 | &setlist, &showlist); |
| 7773 | |
| 7774 | add_setshow_enum_cmd ("follow-fork-mode", class_run, |
| 7775 | follow_fork_mode_kind_names, |
| 7776 | &follow_fork_mode_string, _("\ |
| 7777 | Set debugger response to a program call of fork or vfork."), _("\ |
| 7778 | Show debugger response to a program call of fork or vfork."), _("\ |
| 7779 | A fork or vfork creates a new process. follow-fork-mode can be:\n\ |
| 7780 | parent - the original process is debugged after a fork\n\ |
| 7781 | child - the new process is debugged after a fork\n\ |
| 7782 | The unfollowed process will continue to run.\n\ |
| 7783 | By default, the debugger will follow the parent process."), |
| 7784 | NULL, |
| 7785 | show_follow_fork_mode_string, |
| 7786 | &setlist, &showlist); |
| 7787 | |
| 7788 | add_setshow_enum_cmd ("follow-exec-mode", class_run, |
| 7789 | follow_exec_mode_names, |
| 7790 | &follow_exec_mode_string, _("\ |
| 7791 | Set debugger response to a program call of exec."), _("\ |
| 7792 | Show debugger response to a program call of exec."), _("\ |
| 7793 | An exec call replaces the program image of a process.\n\ |
| 7794 | \n\ |
| 7795 | follow-exec-mode can be:\n\ |
| 7796 | \n\ |
| 7797 | new - the debugger creates a new inferior and rebinds the process\n\ |
| 7798 | to this new inferior. The program the process was running before\n\ |
| 7799 | the exec call can be restarted afterwards by restarting the original\n\ |
| 7800 | inferior.\n\ |
| 7801 | \n\ |
| 7802 | same - the debugger keeps the process bound to the same inferior.\n\ |
| 7803 | The new executable image replaces the previous executable loaded in\n\ |
| 7804 | the inferior. Restarting the inferior after the exec call restarts\n\ |
| 7805 | the executable the process was running after the exec call.\n\ |
| 7806 | \n\ |
| 7807 | By default, the debugger will use the same inferior."), |
| 7808 | NULL, |
| 7809 | show_follow_exec_mode_string, |
| 7810 | &setlist, &showlist); |
| 7811 | |
| 7812 | add_setshow_enum_cmd ("scheduler-locking", class_run, |
| 7813 | scheduler_enums, &scheduler_mode, _("\ |
| 7814 | Set mode for locking scheduler during execution."), _("\ |
| 7815 | Show mode for locking scheduler during execution."), _("\ |
| 7816 | off == no locking (threads may preempt at any time)\n\ |
| 7817 | on == full locking (no thread except the current thread may run)\n\ |
| 7818 | step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\ |
| 7819 | In this mode, other threads may run during other commands."), |
| 7820 | set_schedlock_func, /* traps on target vector */ |
| 7821 | show_scheduler_mode, |
| 7822 | &setlist, &showlist); |
| 7823 | |
| 7824 | add_setshow_boolean_cmd ("schedule-multiple", class_run, &sched_multi, _("\ |
| 7825 | Set mode for resuming threads of all processes."), _("\ |
| 7826 | Show mode for resuming threads of all processes."), _("\ |
| 7827 | When on, execution commands (such as 'continue' or 'next') resume all\n\ |
| 7828 | threads of all processes. When off (which is the default), execution\n\ |
| 7829 | commands only resume the threads of the current process. The set of\n\ |
| 7830 | threads that are resumed is further refined by the scheduler-locking\n\ |
| 7831 | mode (see help set scheduler-locking)."), |
| 7832 | NULL, |
| 7833 | show_schedule_multiple, |
| 7834 | &setlist, &showlist); |
| 7835 | |
| 7836 | add_setshow_boolean_cmd ("step-mode", class_run, &step_stop_if_no_debug, _("\ |
| 7837 | Set mode of the step operation."), _("\ |
| 7838 | Show mode of the step operation."), _("\ |
| 7839 | When set, doing a step over a function without debug line information\n\ |
| 7840 | will stop at the first instruction of that function. Otherwise, the\n\ |
| 7841 | function is skipped and the step command stops at a different source line."), |
| 7842 | NULL, |
| 7843 | show_step_stop_if_no_debug, |
| 7844 | &setlist, &showlist); |
| 7845 | |
| 7846 | add_setshow_auto_boolean_cmd ("displaced-stepping", class_run, |
| 7847 | &can_use_displaced_stepping, _("\ |
| 7848 | Set debugger's willingness to use displaced stepping."), _("\ |
| 7849 | Show debugger's willingness to use displaced stepping."), _("\ |
| 7850 | If on, gdb will use displaced stepping to step over breakpoints if it is\n\ |
| 7851 | supported by the target architecture. If off, gdb will not use displaced\n\ |
| 7852 | stepping to step over breakpoints, even if such is supported by the target\n\ |
| 7853 | architecture. If auto (which is the default), gdb will use displaced stepping\n\ |
| 7854 | if the target architecture supports it and non-stop mode is active, but will not\n\ |
| 7855 | use it in all-stop mode (see help set non-stop)."), |
| 7856 | NULL, |
| 7857 | show_can_use_displaced_stepping, |
| 7858 | &setlist, &showlist); |
| 7859 | |
| 7860 | add_setshow_enum_cmd ("exec-direction", class_run, exec_direction_names, |
| 7861 | &exec_direction, _("Set direction of execution.\n\ |
| 7862 | Options are 'forward' or 'reverse'."), |
| 7863 | _("Show direction of execution (forward/reverse)."), |
| 7864 | _("Tells gdb whether to execute forward or backward."), |
| 7865 | set_exec_direction_func, show_exec_direction_func, |
| 7866 | &setlist, &showlist); |
| 7867 | |
| 7868 | /* Set/show detach-on-fork: user-settable mode. */ |
| 7869 | |
| 7870 | add_setshow_boolean_cmd ("detach-on-fork", class_run, &detach_fork, _("\ |
| 7871 | Set whether gdb will detach the child of a fork."), _("\ |
| 7872 | Show whether gdb will detach the child of a fork."), _("\ |
| 7873 | Tells gdb whether to detach the child of a fork."), |
| 7874 | NULL, NULL, &setlist, &showlist); |
| 7875 | |
| 7876 | /* Set/show disable address space randomization mode. */ |
| 7877 | |
| 7878 | add_setshow_boolean_cmd ("disable-randomization", class_support, |
| 7879 | &disable_randomization, _("\ |
| 7880 | Set disabling of debuggee's virtual address space randomization."), _("\ |
| 7881 | Show disabling of debuggee's virtual address space randomization."), _("\ |
| 7882 | When this mode is on (which is the default), randomization of the virtual\n\ |
| 7883 | address space is disabled. Standalone programs run with the randomization\n\ |
| 7884 | enabled by default on some platforms."), |
| 7885 | &set_disable_randomization, |
| 7886 | &show_disable_randomization, |
| 7887 | &setlist, &showlist); |
| 7888 | |
| 7889 | /* ptid initializations */ |
| 7890 | inferior_ptid = null_ptid; |
| 7891 | target_last_wait_ptid = minus_one_ptid; |
| 7892 | |
| 7893 | observer_attach_thread_ptid_changed (infrun_thread_ptid_changed); |
| 7894 | observer_attach_thread_stop_requested (infrun_thread_stop_requested); |
| 7895 | observer_attach_thread_exit (infrun_thread_thread_exit); |
| 7896 | observer_attach_inferior_exit (infrun_inferior_exit); |
| 7897 | |
| 7898 | /* Explicitly create without lookup, since that tries to create a |
| 7899 | value with a void typed value, and when we get here, gdbarch |
| 7900 | isn't initialized yet. At this point, we're quite sure there |
| 7901 | isn't another convenience variable of the same name. */ |
| 7902 | create_internalvar_type_lazy ("_siginfo", &siginfo_funcs, NULL); |
| 7903 | |
| 7904 | add_setshow_boolean_cmd ("observer", no_class, |
| 7905 | &observer_mode_1, _("\ |
| 7906 | Set whether gdb controls the inferior in observer mode."), _("\ |
| 7907 | Show whether gdb controls the inferior in observer mode."), _("\ |
| 7908 | In observer mode, GDB can get data from the inferior, but not\n\ |
| 7909 | affect its execution. Registers and memory may not be changed,\n\ |
| 7910 | breakpoints may not be set, and the program cannot be interrupted\n\ |
| 7911 | or signalled."), |
| 7912 | set_observer_mode, |
| 7913 | show_observer_mode, |
| 7914 | &setlist, |
| 7915 | &showlist); |
| 7916 | } |