1 /* Target-struct-independent code to start (run) and stop an inferior 2 process. 3 4 Copyright (C) 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 5 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 6 2008, 2009, 2010, 2011 Free Software Foundation, Inc. 7 8 This file is part of GDB. 9 10 This program is free software; you can redistribute it and/or modify 11 it under the terms of the GNU General Public License as published by 12 the Free Software Foundation; either version 3 of the License, or 13 (at your option) any later version. 14 15 This program is distributed in the hope that it will be useful, 16 but WITHOUT ANY WARRANTY; without even the implied warranty of 17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 18 GNU General Public License for more details. 19 20 You should have received a copy of the GNU General Public License 21 along with this program. If not, see <http://www.gnu.org/licenses/>. */ 22 23 #include "defs.h" 24 #include "gdb_string.h" 25 #include <ctype.h> 26 #include "symtab.h" 27 #include "frame.h" 28 #include "inferior.h" 29 #include "exceptions.h" 30 #include "breakpoint.h" 31 #include "gdb_wait.h" 32 #include "gdbcore.h" 33 #include "gdbcmd.h" 34 #include "cli/cli-script.h" 35 #include "target.h" 36 #include "gdbthread.h" 37 #include "annotate.h" 38 #include "symfile.h" 39 #include "top.h" 40 #include <signal.h> 41 #include "inf-loop.h" 42 #include "regcache.h" 43 #include "value.h" 44 #include "observer.h" 45 #include "language.h" 46 #include "solib.h" 47 #include "main.h" 48 #include "dictionary.h" 49 #include "block.h" 50 #include "gdb_assert.h" 51 #include "mi/mi-common.h" 52 #include "event-top.h" 53 #include "record.h" 54 #include "inline-frame.h" 55 #include "jit.h" 56 #include "tracepoint.h" 57 58 /* Prototypes for local functions */ 59 60 static void signals_info (char *, int); 61 62 static void handle_command (char *, int); 63 64 static void sig_print_info (enum target_signal); 65 66 static void sig_print_header (void); 67 68 static void resume_cleanups (void *); 69 70 static int hook_stop_stub (void *); 71 72 static int restore_selected_frame (void *); 73 74 static int follow_fork (void); 75 76 static void set_schedlock_func (char *args, int from_tty, 77 struct cmd_list_element *c); 78 79 static int currently_stepping (struct thread_info *tp); 80 81 static int currently_stepping_or_nexting_callback (struct thread_info *tp, 82 void *data); 83 84 static void xdb_handle_command (char *args, int from_tty); 85 86 static int prepare_to_proceed (int); 87 88 static void print_exited_reason (int exitstatus); 89 90 static void print_signal_exited_reason (enum target_signal siggnal); 91 92 static void print_no_history_reason (void); 93 94 static void print_signal_received_reason (enum target_signal siggnal); 95 96 static void print_end_stepping_range_reason (void); 97 98 void _initialize_infrun (void); 99 100 void nullify_last_target_wait_ptid (void); 101 102 /* When set, stop the 'step' command if we enter a function which has 103 no line number information. The normal behavior is that we step 104 over such function. */ 105 int step_stop_if_no_debug = 0; 106 static void 107 show_step_stop_if_no_debug (struct ui_file *file, int from_tty, 108 struct cmd_list_element *c, const char *value) 109 { 110 fprintf_filtered (file, _("Mode of the step operation is %s.\n"), value); 111 } 112 113 /* In asynchronous mode, but simulating synchronous execution. */ 114 115 int sync_execution = 0; 116 117 /* wait_for_inferior and normal_stop use this to notify the user 118 when the inferior stopped in a different thread than it had been 119 running in. */ 120 121 static ptid_t previous_inferior_ptid; 122 123 /* Default behavior is to detach newly forked processes (legacy). */ 124 int detach_fork = 1; 125 126 int debug_displaced = 0; 127 static void 128 show_debug_displaced (struct ui_file *file, int from_tty, 129 struct cmd_list_element *c, const char *value) 130 { 131 fprintf_filtered (file, _("Displace stepping debugging is %s.\n"), value); 132 } 133 134 int debug_infrun = 0; 135 static void 136 show_debug_infrun (struct ui_file *file, int from_tty, 137 struct cmd_list_element *c, const char *value) 138 { 139 fprintf_filtered (file, _("Inferior debugging is %s.\n"), value); 140 } 141 142 /* If the program uses ELF-style shared libraries, then calls to 143 functions in shared libraries go through stubs, which live in a 144 table called the PLT (Procedure Linkage Table). The first time the 145 function is called, the stub sends control to the dynamic linker, 146 which looks up the function's real address, patches the stub so 147 that future calls will go directly to the function, and then passes 148 control to the function. 149 150 If we are stepping at the source level, we don't want to see any of 151 this --- we just want to skip over the stub and the dynamic linker. 152 The simple approach is to single-step until control leaves the 153 dynamic linker. 154 155 However, on some systems (e.g., Red Hat's 5.2 distribution) the 156 dynamic linker calls functions in the shared C library, so you 157 can't tell from the PC alone whether the dynamic linker is still 158 running. In this case, we use a step-resume breakpoint to get us 159 past the dynamic linker, as if we were using "next" to step over a 160 function call. 161 162 in_solib_dynsym_resolve_code() says whether we're in the dynamic 163 linker code or not. Normally, this means we single-step. However, 164 if SKIP_SOLIB_RESOLVER then returns non-zero, then its value is an 165 address where we can place a step-resume breakpoint to get past the 166 linker's symbol resolution function. 167 168 in_solib_dynsym_resolve_code() can generally be implemented in a 169 pretty portable way, by comparing the PC against the address ranges 170 of the dynamic linker's sections. 171 172 SKIP_SOLIB_RESOLVER is generally going to be system-specific, since 173 it depends on internal details of the dynamic linker. It's usually 174 not too hard to figure out where to put a breakpoint, but it 175 certainly isn't portable. SKIP_SOLIB_RESOLVER should do plenty of 176 sanity checking. If it can't figure things out, returning zero and 177 getting the (possibly confusing) stepping behavior is better than 178 signalling an error, which will obscure the change in the 179 inferior's state. */ 180 181 /* This function returns TRUE if pc is the address of an instruction 182 that lies within the dynamic linker (such as the event hook, or the 183 dld itself). 184 185 This function must be used only when a dynamic linker event has 186 been caught, and the inferior is being stepped out of the hook, or 187 undefined results are guaranteed. */ 188 189 #ifndef SOLIB_IN_DYNAMIC_LINKER 190 #define SOLIB_IN_DYNAMIC_LINKER(pid,pc) 0 191 #endif 192 193 /* "Observer mode" is somewhat like a more extreme version of 194 non-stop, in which all GDB operations that might affect the 195 target's execution have been disabled. */ 196 197 static int non_stop_1 = 0; 198 199 int observer_mode = 0; 200 static int observer_mode_1 = 0; 201 202 static void 203 set_observer_mode (char *args, int from_tty, 204 struct cmd_list_element *c) 205 { 206 extern int pagination_enabled; 207 208 if (target_has_execution) 209 { 210 observer_mode_1 = observer_mode; 211 error (_("Cannot change this setting while the inferior is running.")); 212 } 213 214 observer_mode = observer_mode_1; 215 216 may_write_registers = !observer_mode; 217 may_write_memory = !observer_mode; 218 may_insert_breakpoints = !observer_mode; 219 may_insert_tracepoints = !observer_mode; 220 /* We can insert fast tracepoints in or out of observer mode, 221 but enable them if we're going into this mode. */ 222 if (observer_mode) 223 may_insert_fast_tracepoints = 1; 224 may_stop = !observer_mode; 225 update_target_permissions (); 226 227 /* Going *into* observer mode we must force non-stop, then 228 going out we leave it that way. */ 229 if (observer_mode) 230 { 231 target_async_permitted = 1; 232 pagination_enabled = 0; 233 non_stop = non_stop_1 = 1; 234 } 235 236 if (from_tty) 237 printf_filtered (_("Observer mode is now %s.\n"), 238 (observer_mode ? "on" : "off")); 239 } 240 241 static void 242 show_observer_mode (struct ui_file *file, int from_tty, 243 struct cmd_list_element *c, const char *value) 244 { 245 fprintf_filtered (file, _("Observer mode is %s.\n"), value); 246 } 247 248 /* This updates the value of observer mode based on changes in 249 permissions. Note that we are deliberately ignoring the values of 250 may-write-registers and may-write-memory, since the user may have 251 reason to enable these during a session, for instance to turn on a 252 debugging-related global. */ 253 254 void 255 update_observer_mode (void) 256 { 257 int newval; 258 259 newval = (!may_insert_breakpoints 260 && !may_insert_tracepoints 261 && may_insert_fast_tracepoints 262 && !may_stop 263 && non_stop); 264 265 /* Let the user know if things change. */ 266 if (newval != observer_mode) 267 printf_filtered (_("Observer mode is now %s.\n"), 268 (newval ? "on" : "off")); 269 270 observer_mode = observer_mode_1 = newval; 271 } 272 273 /* Tables of how to react to signals; the user sets them. */ 274 275 static unsigned char *signal_stop; 276 static unsigned char *signal_print; 277 static unsigned char *signal_program; 278 279 #define SET_SIGS(nsigs,sigs,flags) \ 280 do { \ 281 int signum = (nsigs); \ 282 while (signum-- > 0) \ 283 if ((sigs)[signum]) \ 284 (flags)[signum] = 1; \ 285 } while (0) 286 287 #define UNSET_SIGS(nsigs,sigs,flags) \ 288 do { \ 289 int signum = (nsigs); \ 290 while (signum-- > 0) \ 291 if ((sigs)[signum]) \ 292 (flags)[signum] = 0; \ 293 } while (0) 294 295 /* Value to pass to target_resume() to cause all threads to resume. */ 296 297 #define RESUME_ALL minus_one_ptid 298 299 /* Command list pointer for the "stop" placeholder. */ 300 301 static struct cmd_list_element *stop_command; 302 303 /* Function inferior was in as of last step command. */ 304 305 static struct symbol *step_start_function; 306 307 /* Nonzero if we want to give control to the user when we're notified 308 of shared library events by the dynamic linker. */ 309 int stop_on_solib_events; 310 static void 311 show_stop_on_solib_events (struct ui_file *file, int from_tty, 312 struct cmd_list_element *c, const char *value) 313 { 314 fprintf_filtered (file, _("Stopping for shared library events is %s.\n"), 315 value); 316 } 317 318 /* Nonzero means expecting a trace trap 319 and should stop the inferior and return silently when it happens. */ 320 321 int stop_after_trap; 322 323 /* Save register contents here when executing a "finish" command or are 324 about to pop a stack dummy frame, if-and-only-if proceed_to_finish is set. 325 Thus this contains the return value from the called function (assuming 326 values are returned in a register). */ 327 328 struct regcache *stop_registers; 329 330 /* Nonzero after stop if current stack frame should be printed. */ 331 332 static int stop_print_frame; 333 334 /* This is a cached copy of the pid/waitstatus of the last event 335 returned by target_wait()/deprecated_target_wait_hook(). This 336 information is returned by get_last_target_status(). */ 337 static ptid_t target_last_wait_ptid; 338 static struct target_waitstatus target_last_waitstatus; 339 340 static void context_switch (ptid_t ptid); 341 342 void init_thread_stepping_state (struct thread_info *tss); 343 344 void init_infwait_state (void); 345 346 static const char follow_fork_mode_child[] = "child"; 347 static const char follow_fork_mode_parent[] = "parent"; 348 349 static const char *follow_fork_mode_kind_names[] = { 350 follow_fork_mode_child, 351 follow_fork_mode_parent, 352 NULL 353 }; 354 355 static const char *follow_fork_mode_string = follow_fork_mode_parent; 356 static void 357 show_follow_fork_mode_string (struct ui_file *file, int from_tty, 358 struct cmd_list_element *c, const char *value) 359 { 360 fprintf_filtered (file, 361 _("Debugger response to a program " 362 "call of fork or vfork is \"%s\".\n"), 363 value); 364 } 365 366 367 /* Tell the target to follow the fork we're stopped at. Returns true 368 if the inferior should be resumed; false, if the target for some 369 reason decided it's best not to resume. */ 370 371 static int 372 follow_fork (void) 373 { 374 int follow_child = (follow_fork_mode_string == follow_fork_mode_child); 375 int should_resume = 1; 376 struct thread_info *tp; 377 378 /* Copy user stepping state to the new inferior thread. FIXME: the 379 followed fork child thread should have a copy of most of the 380 parent thread structure's run control related fields, not just these. 381 Initialized to avoid "may be used uninitialized" warnings from gcc. */ 382 struct breakpoint *step_resume_breakpoint = NULL; 383 struct breakpoint *exception_resume_breakpoint = NULL; 384 CORE_ADDR step_range_start = 0; 385 CORE_ADDR step_range_end = 0; 386 struct frame_id step_frame_id = { 0 }; 387 388 if (!non_stop) 389 { 390 ptid_t wait_ptid; 391 struct target_waitstatus wait_status; 392 393 /* Get the last target status returned by target_wait(). */ 394 get_last_target_status (&wait_ptid, &wait_status); 395 396 /* If not stopped at a fork event, then there's nothing else to 397 do. */ 398 if (wait_status.kind != TARGET_WAITKIND_FORKED 399 && wait_status.kind != TARGET_WAITKIND_VFORKED) 400 return 1; 401 402 /* Check if we switched over from WAIT_PTID, since the event was 403 reported. */ 404 if (!ptid_equal (wait_ptid, minus_one_ptid) 405 && !ptid_equal (inferior_ptid, wait_ptid)) 406 { 407 /* We did. Switch back to WAIT_PTID thread, to tell the 408 target to follow it (in either direction). We'll 409 afterwards refuse to resume, and inform the user what 410 happened. */ 411 switch_to_thread (wait_ptid); 412 should_resume = 0; 413 } 414 } 415 416 tp = inferior_thread (); 417 418 /* If there were any forks/vforks that were caught and are now to be 419 followed, then do so now. */ 420 switch (tp->pending_follow.kind) 421 { 422 case TARGET_WAITKIND_FORKED: 423 case TARGET_WAITKIND_VFORKED: 424 { 425 ptid_t parent, child; 426 427 /* If the user did a next/step, etc, over a fork call, 428 preserve the stepping state in the fork child. */ 429 if (follow_child && should_resume) 430 { 431 step_resume_breakpoint = clone_momentary_breakpoint 432 (tp->control.step_resume_breakpoint); 433 step_range_start = tp->control.step_range_start; 434 step_range_end = tp->control.step_range_end; 435 step_frame_id = tp->control.step_frame_id; 436 exception_resume_breakpoint 437 = clone_momentary_breakpoint (tp->control.exception_resume_breakpoint); 438 439 /* For now, delete the parent's sr breakpoint, otherwise, 440 parent/child sr breakpoints are considered duplicates, 441 and the child version will not be installed. Remove 442 this when the breakpoints module becomes aware of 443 inferiors and address spaces. */ 444 delete_step_resume_breakpoint (tp); 445 tp->control.step_range_start = 0; 446 tp->control.step_range_end = 0; 447 tp->control.step_frame_id = null_frame_id; 448 delete_exception_resume_breakpoint (tp); 449 } 450 451 parent = inferior_ptid; 452 child = tp->pending_follow.value.related_pid; 453 454 /* Tell the target to do whatever is necessary to follow 455 either parent or child. */ 456 if (target_follow_fork (follow_child)) 457 { 458 /* Target refused to follow, or there's some other reason 459 we shouldn't resume. */ 460 should_resume = 0; 461 } 462 else 463 { 464 /* This pending follow fork event is now handled, one way 465 or another. The previous selected thread may be gone 466 from the lists by now, but if it is still around, need 467 to clear the pending follow request. */ 468 tp = find_thread_ptid (parent); 469 if (tp) 470 tp->pending_follow.kind = TARGET_WAITKIND_SPURIOUS; 471 472 /* This makes sure we don't try to apply the "Switched 473 over from WAIT_PID" logic above. */ 474 nullify_last_target_wait_ptid (); 475 476 /* If we followed the child, switch to it... */ 477 if (follow_child) 478 { 479 switch_to_thread (child); 480 481 /* ... and preserve the stepping state, in case the 482 user was stepping over the fork call. */ 483 if (should_resume) 484 { 485 tp = inferior_thread (); 486 tp->control.step_resume_breakpoint 487 = step_resume_breakpoint; 488 tp->control.step_range_start = step_range_start; 489 tp->control.step_range_end = step_range_end; 490 tp->control.step_frame_id = step_frame_id; 491 tp->control.exception_resume_breakpoint 492 = exception_resume_breakpoint; 493 } 494 else 495 { 496 /* If we get here, it was because we're trying to 497 resume from a fork catchpoint, but, the user 498 has switched threads away from the thread that 499 forked. In that case, the resume command 500 issued is most likely not applicable to the 501 child, so just warn, and refuse to resume. */ 502 warning (_("Not resuming: switched threads " 503 "before following fork child.\n")); 504 } 505 506 /* Reset breakpoints in the child as appropriate. */ 507 follow_inferior_reset_breakpoints (); 508 } 509 else 510 switch_to_thread (parent); 511 } 512 } 513 break; 514 case TARGET_WAITKIND_SPURIOUS: 515 /* Nothing to follow. */ 516 break; 517 default: 518 internal_error (__FILE__, __LINE__, 519 "Unexpected pending_follow.kind %d\n", 520 tp->pending_follow.kind); 521 break; 522 } 523 524 return should_resume; 525 } 526 527 void 528 follow_inferior_reset_breakpoints (void) 529 { 530 struct thread_info *tp = inferior_thread (); 531 532 /* Was there a step_resume breakpoint? (There was if the user 533 did a "next" at the fork() call.) If so, explicitly reset its 534 thread number. 535 536 step_resumes are a form of bp that are made to be per-thread. 537 Since we created the step_resume bp when the parent process 538 was being debugged, and now are switching to the child process, 539 from the breakpoint package's viewpoint, that's a switch of 540 "threads". We must update the bp's notion of which thread 541 it is for, or it'll be ignored when it triggers. */ 542 543 if (tp->control.step_resume_breakpoint) 544 breakpoint_re_set_thread (tp->control.step_resume_breakpoint); 545 546 if (tp->control.exception_resume_breakpoint) 547 breakpoint_re_set_thread (tp->control.exception_resume_breakpoint); 548 549 /* Reinsert all breakpoints in the child. The user may have set 550 breakpoints after catching the fork, in which case those 551 were never set in the child, but only in the parent. This makes 552 sure the inserted breakpoints match the breakpoint list. */ 553 554 breakpoint_re_set (); 555 insert_breakpoints (); 556 } 557 558 /* The child has exited or execed: resume threads of the parent the 559 user wanted to be executing. */ 560 561 static int 562 proceed_after_vfork_done (struct thread_info *thread, 563 void *arg) 564 { 565 int pid = * (int *) arg; 566 567 if (ptid_get_pid (thread->ptid) == pid 568 && is_running (thread->ptid) 569 && !is_executing (thread->ptid) 570 && !thread->stop_requested 571 && thread->suspend.stop_signal == TARGET_SIGNAL_0) 572 { 573 if (debug_infrun) 574 fprintf_unfiltered (gdb_stdlog, 575 "infrun: resuming vfork parent thread %s\n", 576 target_pid_to_str (thread->ptid)); 577 578 switch_to_thread (thread->ptid); 579 clear_proceed_status (); 580 proceed ((CORE_ADDR) -1, TARGET_SIGNAL_DEFAULT, 0); 581 } 582 583 return 0; 584 } 585 586 /* Called whenever we notice an exec or exit event, to handle 587 detaching or resuming a vfork parent. */ 588 589 static void 590 handle_vfork_child_exec_or_exit (int exec) 591 { 592 struct inferior *inf = current_inferior (); 593 594 if (inf->vfork_parent) 595 { 596 int resume_parent = -1; 597 598 /* This exec or exit marks the end of the shared memory region 599 between the parent and the child. If the user wanted to 600 detach from the parent, now is the time. */ 601 602 if (inf->vfork_parent->pending_detach) 603 { 604 struct thread_info *tp; 605 struct cleanup *old_chain; 606 struct program_space *pspace; 607 struct address_space *aspace; 608 609 /* follow-fork child, detach-on-fork on. */ 610 611 old_chain = make_cleanup_restore_current_thread (); 612 613 /* We're letting loose of the parent. */ 614 tp = any_live_thread_of_process (inf->vfork_parent->pid); 615 switch_to_thread (tp->ptid); 616 617 /* We're about to detach from the parent, which implicitly 618 removes breakpoints from its address space. There's a 619 catch here: we want to reuse the spaces for the child, 620 but, parent/child are still sharing the pspace at this 621 point, although the exec in reality makes the kernel give 622 the child a fresh set of new pages. The problem here is 623 that the breakpoints module being unaware of this, would 624 likely chose the child process to write to the parent 625 address space. Swapping the child temporarily away from 626 the spaces has the desired effect. Yes, this is "sort 627 of" a hack. */ 628 629 pspace = inf->pspace; 630 aspace = inf->aspace; 631 inf->aspace = NULL; 632 inf->pspace = NULL; 633 634 if (debug_infrun || info_verbose) 635 { 636 target_terminal_ours (); 637 638 if (exec) 639 fprintf_filtered (gdb_stdlog, 640 "Detaching vfork parent process " 641 "%d after child exec.\n", 642 inf->vfork_parent->pid); 643 else 644 fprintf_filtered (gdb_stdlog, 645 "Detaching vfork parent process " 646 "%d after child exit.\n", 647 inf->vfork_parent->pid); 648 } 649 650 target_detach (NULL, 0); 651 652 /* Put it back. */ 653 inf->pspace = pspace; 654 inf->aspace = aspace; 655 656 do_cleanups (old_chain); 657 } 658 else if (exec) 659 { 660 /* We're staying attached to the parent, so, really give the 661 child a new address space. */ 662 inf->pspace = add_program_space (maybe_new_address_space ()); 663 inf->aspace = inf->pspace->aspace; 664 inf->removable = 1; 665 set_current_program_space (inf->pspace); 666 667 resume_parent = inf->vfork_parent->pid; 668 669 /* Break the bonds. */ 670 inf->vfork_parent->vfork_child = NULL; 671 } 672 else 673 { 674 struct cleanup *old_chain; 675 struct program_space *pspace; 676 677 /* If this is a vfork child exiting, then the pspace and 678 aspaces were shared with the parent. Since we're 679 reporting the process exit, we'll be mourning all that is 680 found in the address space, and switching to null_ptid, 681 preparing to start a new inferior. But, since we don't 682 want to clobber the parent's address/program spaces, we 683 go ahead and create a new one for this exiting 684 inferior. */ 685 686 /* Switch to null_ptid, so that clone_program_space doesn't want 687 to read the selected frame of a dead process. */ 688 old_chain = save_inferior_ptid (); 689 inferior_ptid = null_ptid; 690 691 /* This inferior is dead, so avoid giving the breakpoints 692 module the option to write through to it (cloning a 693 program space resets breakpoints). */ 694 inf->aspace = NULL; 695 inf->pspace = NULL; 696 pspace = add_program_space (maybe_new_address_space ()); 697 set_current_program_space (pspace); 698 inf->removable = 1; 699 clone_program_space (pspace, inf->vfork_parent->pspace); 700 inf->pspace = pspace; 701 inf->aspace = pspace->aspace; 702 703 /* Put back inferior_ptid. We'll continue mourning this 704 inferior. */ 705 do_cleanups (old_chain); 706 707 resume_parent = inf->vfork_parent->pid; 708 /* Break the bonds. */ 709 inf->vfork_parent->vfork_child = NULL; 710 } 711 712 inf->vfork_parent = NULL; 713 714 gdb_assert (current_program_space == inf->pspace); 715 716 if (non_stop && resume_parent != -1) 717 { 718 /* If the user wanted the parent to be running, let it go 719 free now. */ 720 struct cleanup *old_chain = make_cleanup_restore_current_thread (); 721 722 if (debug_infrun) 723 fprintf_unfiltered (gdb_stdlog, 724 "infrun: resuming vfork parent process %d\n", 725 resume_parent); 726 727 iterate_over_threads (proceed_after_vfork_done, &resume_parent); 728 729 do_cleanups (old_chain); 730 } 731 } 732 } 733 734 /* Enum strings for "set|show displaced-stepping". */ 735 736 static const char follow_exec_mode_new[] = "new"; 737 static const char follow_exec_mode_same[] = "same"; 738 static const char *follow_exec_mode_names[] = 739 { 740 follow_exec_mode_new, 741 follow_exec_mode_same, 742 NULL, 743 }; 744 745 static const char *follow_exec_mode_string = follow_exec_mode_same; 746 static void 747 show_follow_exec_mode_string (struct ui_file *file, int from_tty, 748 struct cmd_list_element *c, const char *value) 749 { 750 fprintf_filtered (file, _("Follow exec mode is \"%s\".\n"), value); 751 } 752 753 /* EXECD_PATHNAME is assumed to be non-NULL. */ 754 755 static void 756 follow_exec (ptid_t pid, char *execd_pathname) 757 { 758 struct thread_info *th = inferior_thread (); 759 struct inferior *inf = current_inferior (); 760 761 /* This is an exec event that we actually wish to pay attention to. 762 Refresh our symbol table to the newly exec'd program, remove any 763 momentary bp's, etc. 764 765 If there are breakpoints, they aren't really inserted now, 766 since the exec() transformed our inferior into a fresh set 767 of instructions. 768 769 We want to preserve symbolic breakpoints on the list, since 770 we have hopes that they can be reset after the new a.out's 771 symbol table is read. 772 773 However, any "raw" breakpoints must be removed from the list 774 (e.g., the solib bp's), since their address is probably invalid 775 now. 776 777 And, we DON'T want to call delete_breakpoints() here, since 778 that may write the bp's "shadow contents" (the instruction 779 value that was overwritten witha TRAP instruction). Since 780 we now have a new a.out, those shadow contents aren't valid. */ 781 782 mark_breakpoints_out (); 783 784 update_breakpoints_after_exec (); 785 786 /* If there was one, it's gone now. We cannot truly step-to-next 787 statement through an exec(). */ 788 th->control.step_resume_breakpoint = NULL; 789 th->control.exception_resume_breakpoint = NULL; 790 th->control.step_range_start = 0; 791 th->control.step_range_end = 0; 792 793 /* The target reports the exec event to the main thread, even if 794 some other thread does the exec, and even if the main thread was 795 already stopped --- if debugging in non-stop mode, it's possible 796 the user had the main thread held stopped in the previous image 797 --- release it now. This is the same behavior as step-over-exec 798 with scheduler-locking on in all-stop mode. */ 799 th->stop_requested = 0; 800 801 /* What is this a.out's name? */ 802 printf_unfiltered (_("%s is executing new program: %s\n"), 803 target_pid_to_str (inferior_ptid), 804 execd_pathname); 805 806 /* We've followed the inferior through an exec. Therefore, the 807 inferior has essentially been killed & reborn. */ 808 809 gdb_flush (gdb_stdout); 810 811 breakpoint_init_inferior (inf_execd); 812 813 if (gdb_sysroot && *gdb_sysroot) 814 { 815 char *name = alloca (strlen (gdb_sysroot) 816 + strlen (execd_pathname) 817 + 1); 818 819 strcpy (name, gdb_sysroot); 820 strcat (name, execd_pathname); 821 execd_pathname = name; 822 } 823 824 /* Reset the shared library package. This ensures that we get a 825 shlib event when the child reaches "_start", at which point the 826 dld will have had a chance to initialize the child. */ 827 /* Also, loading a symbol file below may trigger symbol lookups, and 828 we don't want those to be satisfied by the libraries of the 829 previous incarnation of this process. */ 830 no_shared_libraries (NULL, 0); 831 832 if (follow_exec_mode_string == follow_exec_mode_new) 833 { 834 struct program_space *pspace; 835 836 /* The user wants to keep the old inferior and program spaces 837 around. Create a new fresh one, and switch to it. */ 838 839 inf = add_inferior (current_inferior ()->pid); 840 pspace = add_program_space (maybe_new_address_space ()); 841 inf->pspace = pspace; 842 inf->aspace = pspace->aspace; 843 844 exit_inferior_num_silent (current_inferior ()->num); 845 846 set_current_inferior (inf); 847 set_current_program_space (pspace); 848 } 849 850 gdb_assert (current_program_space == inf->pspace); 851 852 /* That a.out is now the one to use. */ 853 exec_file_attach (execd_pathname, 0); 854 855 /* SYMFILE_DEFER_BP_RESET is used as the proper displacement for PIE 856 (Position Independent Executable) main symbol file will get applied by 857 solib_create_inferior_hook below. breakpoint_re_set would fail to insert 858 the breakpoints with the zero displacement. */ 859 860 symbol_file_add (execd_pathname, SYMFILE_MAINLINE | SYMFILE_DEFER_BP_RESET, 861 NULL, 0); 862 863 set_initial_language (); 864 865 #ifdef SOLIB_CREATE_INFERIOR_HOOK 866 SOLIB_CREATE_INFERIOR_HOOK (PIDGET (inferior_ptid)); 867 #else 868 solib_create_inferior_hook (0); 869 #endif 870 871 jit_inferior_created_hook (); 872 873 breakpoint_re_set (); 874 875 /* Reinsert all breakpoints. (Those which were symbolic have 876 been reset to the proper address in the new a.out, thanks 877 to symbol_file_command...). */ 878 insert_breakpoints (); 879 880 /* The next resume of this inferior should bring it to the shlib 881 startup breakpoints. (If the user had also set bp's on 882 "main" from the old (parent) process, then they'll auto- 883 matically get reset there in the new process.). */ 884 } 885 886 /* Non-zero if we just simulating a single-step. This is needed 887 because we cannot remove the breakpoints in the inferior process 888 until after the `wait' in `wait_for_inferior'. */ 889 static int singlestep_breakpoints_inserted_p = 0; 890 891 /* The thread we inserted single-step breakpoints for. */ 892 static ptid_t singlestep_ptid; 893 894 /* PC when we started this single-step. */ 895 static CORE_ADDR singlestep_pc; 896 897 /* If another thread hit the singlestep breakpoint, we save the original 898 thread here so that we can resume single-stepping it later. */ 899 static ptid_t saved_singlestep_ptid; 900 static int stepping_past_singlestep_breakpoint; 901 902 /* If not equal to null_ptid, this means that after stepping over breakpoint 903 is finished, we need to switch to deferred_step_ptid, and step it. 904 905 The use case is when one thread has hit a breakpoint, and then the user 906 has switched to another thread and issued 'step'. We need to step over 907 breakpoint in the thread which hit the breakpoint, but then continue 908 stepping the thread user has selected. */ 909 static ptid_t deferred_step_ptid; 910 911 /* Displaced stepping. */ 912 913 /* In non-stop debugging mode, we must take special care to manage 914 breakpoints properly; in particular, the traditional strategy for 915 stepping a thread past a breakpoint it has hit is unsuitable. 916 'Displaced stepping' is a tactic for stepping one thread past a 917 breakpoint it has hit while ensuring that other threads running 918 concurrently will hit the breakpoint as they should. 919 920 The traditional way to step a thread T off a breakpoint in a 921 multi-threaded program in all-stop mode is as follows: 922 923 a0) Initially, all threads are stopped, and breakpoints are not 924 inserted. 925 a1) We single-step T, leaving breakpoints uninserted. 926 a2) We insert breakpoints, and resume all threads. 927 928 In non-stop debugging, however, this strategy is unsuitable: we 929 don't want to have to stop all threads in the system in order to 930 continue or step T past a breakpoint. Instead, we use displaced 931 stepping: 932 933 n0) Initially, T is stopped, other threads are running, and 934 breakpoints are inserted. 935 n1) We copy the instruction "under" the breakpoint to a separate 936 location, outside the main code stream, making any adjustments 937 to the instruction, register, and memory state as directed by 938 T's architecture. 939 n2) We single-step T over the instruction at its new location. 940 n3) We adjust the resulting register and memory state as directed 941 by T's architecture. This includes resetting T's PC to point 942 back into the main instruction stream. 943 n4) We resume T. 944 945 This approach depends on the following gdbarch methods: 946 947 - gdbarch_max_insn_length and gdbarch_displaced_step_location 948 indicate where to copy the instruction, and how much space must 949 be reserved there. We use these in step n1. 950 951 - gdbarch_displaced_step_copy_insn copies a instruction to a new 952 address, and makes any necessary adjustments to the instruction, 953 register contents, and memory. We use this in step n1. 954 955 - gdbarch_displaced_step_fixup adjusts registers and memory after 956 we have successfuly single-stepped the instruction, to yield the 957 same effect the instruction would have had if we had executed it 958 at its original address. We use this in step n3. 959 960 - gdbarch_displaced_step_free_closure provides cleanup. 961 962 The gdbarch_displaced_step_copy_insn and 963 gdbarch_displaced_step_fixup functions must be written so that 964 copying an instruction with gdbarch_displaced_step_copy_insn, 965 single-stepping across the copied instruction, and then applying 966 gdbarch_displaced_insn_fixup should have the same effects on the 967 thread's memory and registers as stepping the instruction in place 968 would have. Exactly which responsibilities fall to the copy and 969 which fall to the fixup is up to the author of those functions. 970 971 See the comments in gdbarch.sh for details. 972 973 Note that displaced stepping and software single-step cannot 974 currently be used in combination, although with some care I think 975 they could be made to. Software single-step works by placing 976 breakpoints on all possible subsequent instructions; if the 977 displaced instruction is a PC-relative jump, those breakpoints 978 could fall in very strange places --- on pages that aren't 979 executable, or at addresses that are not proper instruction 980 boundaries. (We do generally let other threads run while we wait 981 to hit the software single-step breakpoint, and they might 982 encounter such a corrupted instruction.) One way to work around 983 this would be to have gdbarch_displaced_step_copy_insn fully 984 simulate the effect of PC-relative instructions (and return NULL) 985 on architectures that use software single-stepping. 986 987 In non-stop mode, we can have independent and simultaneous step 988 requests, so more than one thread may need to simultaneously step 989 over a breakpoint. The current implementation assumes there is 990 only one scratch space per process. In this case, we have to 991 serialize access to the scratch space. If thread A wants to step 992 over a breakpoint, but we are currently waiting for some other 993 thread to complete a displaced step, we leave thread A stopped and 994 place it in the displaced_step_request_queue. Whenever a displaced 995 step finishes, we pick the next thread in the queue and start a new 996 displaced step operation on it. See displaced_step_prepare and 997 displaced_step_fixup for details. */ 998 999 struct displaced_step_request 1000 { 1001 ptid_t ptid; 1002 struct displaced_step_request *next; 1003 }; 1004 1005 /* Per-inferior displaced stepping state. */ 1006 struct displaced_step_inferior_state 1007 { 1008 /* Pointer to next in linked list. */ 1009 struct displaced_step_inferior_state *next; 1010 1011 /* The process this displaced step state refers to. */ 1012 int pid; 1013 1014 /* A queue of pending displaced stepping requests. One entry per 1015 thread that needs to do a displaced step. */ 1016 struct displaced_step_request *step_request_queue; 1017 1018 /* If this is not null_ptid, this is the thread carrying out a 1019 displaced single-step in process PID. This thread's state will 1020 require fixing up once it has completed its step. */ 1021 ptid_t step_ptid; 1022 1023 /* The architecture the thread had when we stepped it. */ 1024 struct gdbarch *step_gdbarch; 1025 1026 /* The closure provided gdbarch_displaced_step_copy_insn, to be used 1027 for post-step cleanup. */ 1028 struct displaced_step_closure *step_closure; 1029 1030 /* The address of the original instruction, and the copy we 1031 made. */ 1032 CORE_ADDR step_original, step_copy; 1033 1034 /* Saved contents of copy area. */ 1035 gdb_byte *step_saved_copy; 1036 }; 1037 1038 /* The list of states of processes involved in displaced stepping 1039 presently. */ 1040 static struct displaced_step_inferior_state *displaced_step_inferior_states; 1041 1042 /* Get the displaced stepping state of process PID. */ 1043 1044 static struct displaced_step_inferior_state * 1045 get_displaced_stepping_state (int pid) 1046 { 1047 struct displaced_step_inferior_state *state; 1048 1049 for (state = displaced_step_inferior_states; 1050 state != NULL; 1051 state = state->next) 1052 if (state->pid == pid) 1053 return state; 1054 1055 return NULL; 1056 } 1057 1058 /* Add a new displaced stepping state for process PID to the displaced 1059 stepping state list, or return a pointer to an already existing 1060 entry, if it already exists. Never returns NULL. */ 1061 1062 static struct displaced_step_inferior_state * 1063 add_displaced_stepping_state (int pid) 1064 { 1065 struct displaced_step_inferior_state *state; 1066 1067 for (state = displaced_step_inferior_states; 1068 state != NULL; 1069 state = state->next) 1070 if (state->pid == pid) 1071 return state; 1072 1073 state = xcalloc (1, sizeof (*state)); 1074 state->pid = pid; 1075 state->next = displaced_step_inferior_states; 1076 displaced_step_inferior_states = state; 1077 1078 return state; 1079 } 1080 1081 /* If inferior is in displaced stepping, and ADDR equals to starting address 1082 of copy area, return corresponding displaced_step_closure. Otherwise, 1083 return NULL. */ 1084 1085 struct displaced_step_closure* 1086 get_displaced_step_closure_by_addr (CORE_ADDR addr) 1087 { 1088 struct displaced_step_inferior_state *displaced 1089 = get_displaced_stepping_state (ptid_get_pid (inferior_ptid)); 1090 1091 /* If checking the mode of displaced instruction in copy area. */ 1092 if (displaced && !ptid_equal (displaced->step_ptid, null_ptid) 1093 && (displaced->step_copy == addr)) 1094 return displaced->step_closure; 1095 1096 return NULL; 1097 } 1098 1099 /* Remove the displaced stepping state of process PID. */ 1100 1101 static void 1102 remove_displaced_stepping_state (int pid) 1103 { 1104 struct displaced_step_inferior_state *it, **prev_next_p; 1105 1106 gdb_assert (pid != FAKE_PROCESS_ID); 1107 1108 it = displaced_step_inferior_states; 1109 prev_next_p = &displaced_step_inferior_states; 1110 while (it) 1111 { 1112 if (it->pid == pid) 1113 { 1114 *prev_next_p = it->next; 1115 xfree (it); 1116 return; 1117 } 1118 1119 prev_next_p = &it->next; 1120 it = *prev_next_p; 1121 } 1122 } 1123 1124 static void 1125 infrun_inferior_exit (struct inferior *inf) 1126 { 1127 remove_displaced_stepping_state (inf->pid); 1128 } 1129 1130 /* Enum strings for "set|show displaced-stepping". */ 1131 1132 static const char can_use_displaced_stepping_auto[] = "auto"; 1133 static const char can_use_displaced_stepping_on[] = "on"; 1134 static const char can_use_displaced_stepping_off[] = "off"; 1135 static const char *can_use_displaced_stepping_enum[] = 1136 { 1137 can_use_displaced_stepping_auto, 1138 can_use_displaced_stepping_on, 1139 can_use_displaced_stepping_off, 1140 NULL, 1141 }; 1142 1143 /* If ON, and the architecture supports it, GDB will use displaced 1144 stepping to step over breakpoints. If OFF, or if the architecture 1145 doesn't support it, GDB will instead use the traditional 1146 hold-and-step approach. If AUTO (which is the default), GDB will 1147 decide which technique to use to step over breakpoints depending on 1148 which of all-stop or non-stop mode is active --- displaced stepping 1149 in non-stop mode; hold-and-step in all-stop mode. */ 1150 1151 static const char *can_use_displaced_stepping = 1152 can_use_displaced_stepping_auto; 1153 1154 static void 1155 show_can_use_displaced_stepping (struct ui_file *file, int from_tty, 1156 struct cmd_list_element *c, 1157 const char *value) 1158 { 1159 if (can_use_displaced_stepping == can_use_displaced_stepping_auto) 1160 fprintf_filtered (file, 1161 _("Debugger's willingness to use displaced stepping " 1162 "to step over breakpoints is %s (currently %s).\n"), 1163 value, non_stop ? "on" : "off"); 1164 else 1165 fprintf_filtered (file, 1166 _("Debugger's willingness to use displaced stepping " 1167 "to step over breakpoints is %s.\n"), value); 1168 } 1169 1170 /* Return non-zero if displaced stepping can/should be used to step 1171 over breakpoints. */ 1172 1173 static int 1174 use_displaced_stepping (struct gdbarch *gdbarch) 1175 { 1176 return (((can_use_displaced_stepping == can_use_displaced_stepping_auto 1177 && non_stop) 1178 || can_use_displaced_stepping == can_use_displaced_stepping_on) 1179 && gdbarch_displaced_step_copy_insn_p (gdbarch) 1180 && !RECORD_IS_USED); 1181 } 1182 1183 /* Clean out any stray displaced stepping state. */ 1184 static void 1185 displaced_step_clear (struct displaced_step_inferior_state *displaced) 1186 { 1187 /* Indicate that there is no cleanup pending. */ 1188 displaced->step_ptid = null_ptid; 1189 1190 if (displaced->step_closure) 1191 { 1192 gdbarch_displaced_step_free_closure (displaced->step_gdbarch, 1193 displaced->step_closure); 1194 displaced->step_closure = NULL; 1195 } 1196 } 1197 1198 static void 1199 displaced_step_clear_cleanup (void *arg) 1200 { 1201 struct displaced_step_inferior_state *state = arg; 1202 1203 displaced_step_clear (state); 1204 } 1205 1206 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */ 1207 void 1208 displaced_step_dump_bytes (struct ui_file *file, 1209 const gdb_byte *buf, 1210 size_t len) 1211 { 1212 int i; 1213 1214 for (i = 0; i < len; i++) 1215 fprintf_unfiltered (file, "%02x ", buf[i]); 1216 fputs_unfiltered ("\n", file); 1217 } 1218 1219 /* Prepare to single-step, using displaced stepping. 1220 1221 Note that we cannot use displaced stepping when we have a signal to 1222 deliver. If we have a signal to deliver and an instruction to step 1223 over, then after the step, there will be no indication from the 1224 target whether the thread entered a signal handler or ignored the 1225 signal and stepped over the instruction successfully --- both cases 1226 result in a simple SIGTRAP. In the first case we mustn't do a 1227 fixup, and in the second case we must --- but we can't tell which. 1228 Comments in the code for 'random signals' in handle_inferior_event 1229 explain how we handle this case instead. 1230 1231 Returns 1 if preparing was successful -- this thread is going to be 1232 stepped now; or 0 if displaced stepping this thread got queued. */ 1233 static int 1234 displaced_step_prepare (ptid_t ptid) 1235 { 1236 struct cleanup *old_cleanups, *ignore_cleanups; 1237 struct regcache *regcache = get_thread_regcache (ptid); 1238 struct gdbarch *gdbarch = get_regcache_arch (regcache); 1239 CORE_ADDR original, copy; 1240 ULONGEST len; 1241 struct displaced_step_closure *closure; 1242 struct displaced_step_inferior_state *displaced; 1243 1244 /* We should never reach this function if the architecture does not 1245 support displaced stepping. */ 1246 gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch)); 1247 1248 /* We have to displaced step one thread at a time, as we only have 1249 access to a single scratch space per inferior. */ 1250 1251 displaced = add_displaced_stepping_state (ptid_get_pid (ptid)); 1252 1253 if (!ptid_equal (displaced->step_ptid, null_ptid)) 1254 { 1255 /* Already waiting for a displaced step to finish. Defer this 1256 request and place in queue. */ 1257 struct displaced_step_request *req, *new_req; 1258 1259 if (debug_displaced) 1260 fprintf_unfiltered (gdb_stdlog, 1261 "displaced: defering step of %s\n", 1262 target_pid_to_str (ptid)); 1263 1264 new_req = xmalloc (sizeof (*new_req)); 1265 new_req->ptid = ptid; 1266 new_req->next = NULL; 1267 1268 if (displaced->step_request_queue) 1269 { 1270 for (req = displaced->step_request_queue; 1271 req && req->next; 1272 req = req->next) 1273 ; 1274 req->next = new_req; 1275 } 1276 else 1277 displaced->step_request_queue = new_req; 1278 1279 return 0; 1280 } 1281 else 1282 { 1283 if (debug_displaced) 1284 fprintf_unfiltered (gdb_stdlog, 1285 "displaced: stepping %s now\n", 1286 target_pid_to_str (ptid)); 1287 } 1288 1289 displaced_step_clear (displaced); 1290 1291 old_cleanups = save_inferior_ptid (); 1292 inferior_ptid = ptid; 1293 1294 original = regcache_read_pc (regcache); 1295 1296 copy = gdbarch_displaced_step_location (gdbarch); 1297 len = gdbarch_max_insn_length (gdbarch); 1298 1299 /* Save the original contents of the copy area. */ 1300 displaced->step_saved_copy = xmalloc (len); 1301 ignore_cleanups = make_cleanup (free_current_contents, 1302 &displaced->step_saved_copy); 1303 read_memory (copy, displaced->step_saved_copy, len); 1304 if (debug_displaced) 1305 { 1306 fprintf_unfiltered (gdb_stdlog, "displaced: saved %s: ", 1307 paddress (gdbarch, copy)); 1308 displaced_step_dump_bytes (gdb_stdlog, 1309 displaced->step_saved_copy, 1310 len); 1311 }; 1312 1313 closure = gdbarch_displaced_step_copy_insn (gdbarch, 1314 original, copy, regcache); 1315 1316 /* We don't support the fully-simulated case at present. */ 1317 gdb_assert (closure); 1318 1319 /* Save the information we need to fix things up if the step 1320 succeeds. */ 1321 displaced->step_ptid = ptid; 1322 displaced->step_gdbarch = gdbarch; 1323 displaced->step_closure = closure; 1324 displaced->step_original = original; 1325 displaced->step_copy = copy; 1326 1327 make_cleanup (displaced_step_clear_cleanup, displaced); 1328 1329 /* Resume execution at the copy. */ 1330 regcache_write_pc (regcache, copy); 1331 1332 discard_cleanups (ignore_cleanups); 1333 1334 do_cleanups (old_cleanups); 1335 1336 if (debug_displaced) 1337 fprintf_unfiltered (gdb_stdlog, "displaced: displaced pc to %s\n", 1338 paddress (gdbarch, copy)); 1339 1340 return 1; 1341 } 1342 1343 static void 1344 write_memory_ptid (ptid_t ptid, CORE_ADDR memaddr, 1345 const gdb_byte *myaddr, int len) 1346 { 1347 struct cleanup *ptid_cleanup = save_inferior_ptid (); 1348 1349 inferior_ptid = ptid; 1350 write_memory (memaddr, myaddr, len); 1351 do_cleanups (ptid_cleanup); 1352 } 1353 1354 static void 1355 displaced_step_fixup (ptid_t event_ptid, enum target_signal signal) 1356 { 1357 struct cleanup *old_cleanups; 1358 struct displaced_step_inferior_state *displaced 1359 = get_displaced_stepping_state (ptid_get_pid (event_ptid)); 1360 1361 /* Was any thread of this process doing a displaced step? */ 1362 if (displaced == NULL) 1363 return; 1364 1365 /* Was this event for the pid we displaced? */ 1366 if (ptid_equal (displaced->step_ptid, null_ptid) 1367 || ! ptid_equal (displaced->step_ptid, event_ptid)) 1368 return; 1369 1370 old_cleanups = make_cleanup (displaced_step_clear_cleanup, displaced); 1371 1372 /* Restore the contents of the copy area. */ 1373 { 1374 ULONGEST len = gdbarch_max_insn_length (displaced->step_gdbarch); 1375 1376 write_memory_ptid (displaced->step_ptid, displaced->step_copy, 1377 displaced->step_saved_copy, len); 1378 if (debug_displaced) 1379 fprintf_unfiltered (gdb_stdlog, "displaced: restored %s\n", 1380 paddress (displaced->step_gdbarch, 1381 displaced->step_copy)); 1382 } 1383 1384 /* Did the instruction complete successfully? */ 1385 if (signal == TARGET_SIGNAL_TRAP) 1386 { 1387 /* Fix up the resulting state. */ 1388 gdbarch_displaced_step_fixup (displaced->step_gdbarch, 1389 displaced->step_closure, 1390 displaced->step_original, 1391 displaced->step_copy, 1392 get_thread_regcache (displaced->step_ptid)); 1393 } 1394 else 1395 { 1396 /* Since the instruction didn't complete, all we can do is 1397 relocate the PC. */ 1398 struct regcache *regcache = get_thread_regcache (event_ptid); 1399 CORE_ADDR pc = regcache_read_pc (regcache); 1400 1401 pc = displaced->step_original + (pc - displaced->step_copy); 1402 regcache_write_pc (regcache, pc); 1403 } 1404 1405 do_cleanups (old_cleanups); 1406 1407 displaced->step_ptid = null_ptid; 1408 1409 /* Are there any pending displaced stepping requests? If so, run 1410 one now. Leave the state object around, since we're likely to 1411 need it again soon. */ 1412 while (displaced->step_request_queue) 1413 { 1414 struct displaced_step_request *head; 1415 ptid_t ptid; 1416 struct regcache *regcache; 1417 struct gdbarch *gdbarch; 1418 CORE_ADDR actual_pc; 1419 struct address_space *aspace; 1420 1421 head = displaced->step_request_queue; 1422 ptid = head->ptid; 1423 displaced->step_request_queue = head->next; 1424 xfree (head); 1425 1426 context_switch (ptid); 1427 1428 regcache = get_thread_regcache (ptid); 1429 actual_pc = regcache_read_pc (regcache); 1430 aspace = get_regcache_aspace (regcache); 1431 1432 if (breakpoint_here_p (aspace, actual_pc)) 1433 { 1434 if (debug_displaced) 1435 fprintf_unfiltered (gdb_stdlog, 1436 "displaced: stepping queued %s now\n", 1437 target_pid_to_str (ptid)); 1438 1439 displaced_step_prepare (ptid); 1440 1441 gdbarch = get_regcache_arch (regcache); 1442 1443 if (debug_displaced) 1444 { 1445 CORE_ADDR actual_pc = regcache_read_pc (regcache); 1446 gdb_byte buf[4]; 1447 1448 fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ", 1449 paddress (gdbarch, actual_pc)); 1450 read_memory (actual_pc, buf, sizeof (buf)); 1451 displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf)); 1452 } 1453 1454 if (gdbarch_displaced_step_hw_singlestep (gdbarch, 1455 displaced->step_closure)) 1456 target_resume (ptid, 1, TARGET_SIGNAL_0); 1457 else 1458 target_resume (ptid, 0, TARGET_SIGNAL_0); 1459 1460 /* Done, we're stepping a thread. */ 1461 break; 1462 } 1463 else 1464 { 1465 int step; 1466 struct thread_info *tp = inferior_thread (); 1467 1468 /* The breakpoint we were sitting under has since been 1469 removed. */ 1470 tp->control.trap_expected = 0; 1471 1472 /* Go back to what we were trying to do. */ 1473 step = currently_stepping (tp); 1474 1475 if (debug_displaced) 1476 fprintf_unfiltered (gdb_stdlog, 1477 "breakpoint is gone %s: step(%d)\n", 1478 target_pid_to_str (tp->ptid), step); 1479 1480 target_resume (ptid, step, TARGET_SIGNAL_0); 1481 tp->suspend.stop_signal = TARGET_SIGNAL_0; 1482 1483 /* This request was discarded. See if there's any other 1484 thread waiting for its turn. */ 1485 } 1486 } 1487 } 1488 1489 /* Update global variables holding ptids to hold NEW_PTID if they were 1490 holding OLD_PTID. */ 1491 static void 1492 infrun_thread_ptid_changed (ptid_t old_ptid, ptid_t new_ptid) 1493 { 1494 struct displaced_step_request *it; 1495 struct displaced_step_inferior_state *displaced; 1496 1497 if (ptid_equal (inferior_ptid, old_ptid)) 1498 inferior_ptid = new_ptid; 1499 1500 if (ptid_equal (singlestep_ptid, old_ptid)) 1501 singlestep_ptid = new_ptid; 1502 1503 if (ptid_equal (deferred_step_ptid, old_ptid)) 1504 deferred_step_ptid = new_ptid; 1505 1506 for (displaced = displaced_step_inferior_states; 1507 displaced; 1508 displaced = displaced->next) 1509 { 1510 if (ptid_equal (displaced->step_ptid, old_ptid)) 1511 displaced->step_ptid = new_ptid; 1512 1513 for (it = displaced->step_request_queue; it; it = it->next) 1514 if (ptid_equal (it->ptid, old_ptid)) 1515 it->ptid = new_ptid; 1516 } 1517 } 1518 1519 1520 /* Resuming. */ 1521 1522 /* Things to clean up if we QUIT out of resume (). */ 1523 static void 1524 resume_cleanups (void *ignore) 1525 { 1526 normal_stop (); 1527 } 1528 1529 static const char schedlock_off[] = "off"; 1530 static const char schedlock_on[] = "on"; 1531 static const char schedlock_step[] = "step"; 1532 static const char *scheduler_enums[] = { 1533 schedlock_off, 1534 schedlock_on, 1535 schedlock_step, 1536 NULL 1537 }; 1538 static const char *scheduler_mode = schedlock_off; 1539 static void 1540 show_scheduler_mode (struct ui_file *file, int from_tty, 1541 struct cmd_list_element *c, const char *value) 1542 { 1543 fprintf_filtered (file, 1544 _("Mode for locking scheduler " 1545 "during execution is \"%s\".\n"), 1546 value); 1547 } 1548 1549 static void 1550 set_schedlock_func (char *args, int from_tty, struct cmd_list_element *c) 1551 { 1552 if (!target_can_lock_scheduler) 1553 { 1554 scheduler_mode = schedlock_off; 1555 error (_("Target '%s' cannot support this command."), target_shortname); 1556 } 1557 } 1558 1559 /* True if execution commands resume all threads of all processes by 1560 default; otherwise, resume only threads of the current inferior 1561 process. */ 1562 int sched_multi = 0; 1563 1564 /* Try to setup for software single stepping over the specified location. 1565 Return 1 if target_resume() should use hardware single step. 1566 1567 GDBARCH the current gdbarch. 1568 PC the location to step over. */ 1569 1570 static int 1571 maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc) 1572 { 1573 int hw_step = 1; 1574 1575 if (execution_direction == EXEC_FORWARD 1576 && gdbarch_software_single_step_p (gdbarch) 1577 && gdbarch_software_single_step (gdbarch, get_current_frame ())) 1578 { 1579 hw_step = 0; 1580 /* Do not pull these breakpoints until after a `wait' in 1581 `wait_for_inferior'. */ 1582 singlestep_breakpoints_inserted_p = 1; 1583 singlestep_ptid = inferior_ptid; 1584 singlestep_pc = pc; 1585 } 1586 return hw_step; 1587 } 1588 1589 /* Resume the inferior, but allow a QUIT. This is useful if the user 1590 wants to interrupt some lengthy single-stepping operation 1591 (for child processes, the SIGINT goes to the inferior, and so 1592 we get a SIGINT random_signal, but for remote debugging and perhaps 1593 other targets, that's not true). 1594 1595 STEP nonzero if we should step (zero to continue instead). 1596 SIG is the signal to give the inferior (zero for none). */ 1597 void 1598 resume (int step, enum target_signal sig) 1599 { 1600 int should_resume = 1; 1601 struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0); 1602 struct regcache *regcache = get_current_regcache (); 1603 struct gdbarch *gdbarch = get_regcache_arch (regcache); 1604 struct thread_info *tp = inferior_thread (); 1605 CORE_ADDR pc = regcache_read_pc (regcache); 1606 struct address_space *aspace = get_regcache_aspace (regcache); 1607 1608 QUIT; 1609 1610 if (current_inferior ()->waiting_for_vfork_done) 1611 { 1612 /* Don't try to single-step a vfork parent that is waiting for 1613 the child to get out of the shared memory region (by exec'ing 1614 or exiting). This is particularly important on software 1615 single-step archs, as the child process would trip on the 1616 software single step breakpoint inserted for the parent 1617 process. Since the parent will not actually execute any 1618 instruction until the child is out of the shared region (such 1619 are vfork's semantics), it is safe to simply continue it. 1620 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for 1621 the parent, and tell it to `keep_going', which automatically 1622 re-sets it stepping. */ 1623 if (debug_infrun) 1624 fprintf_unfiltered (gdb_stdlog, 1625 "infrun: resume : clear step\n"); 1626 step = 0; 1627 } 1628 1629 if (debug_infrun) 1630 fprintf_unfiltered (gdb_stdlog, 1631 "infrun: resume (step=%d, signal=%d), " 1632 "trap_expected=%d\n", 1633 step, sig, tp->control.trap_expected); 1634 1635 /* Normally, by the time we reach `resume', the breakpoints are either 1636 removed or inserted, as appropriate. The exception is if we're sitting 1637 at a permanent breakpoint; we need to step over it, but permanent 1638 breakpoints can't be removed. So we have to test for it here. */ 1639 if (breakpoint_here_p (aspace, pc) == permanent_breakpoint_here) 1640 { 1641 if (gdbarch_skip_permanent_breakpoint_p (gdbarch)) 1642 gdbarch_skip_permanent_breakpoint (gdbarch, regcache); 1643 else 1644 error (_("\ 1645 The program is stopped at a permanent breakpoint, but GDB does not know\n\ 1646 how to step past a permanent breakpoint on this architecture. Try using\n\ 1647 a command like `return' or `jump' to continue execution.")); 1648 } 1649 1650 /* If enabled, step over breakpoints by executing a copy of the 1651 instruction at a different address. 1652 1653 We can't use displaced stepping when we have a signal to deliver; 1654 the comments for displaced_step_prepare explain why. The 1655 comments in the handle_inferior event for dealing with 'random 1656 signals' explain what we do instead. 1657 1658 We can't use displaced stepping when we are waiting for vfork_done 1659 event, displaced stepping breaks the vfork child similarly as single 1660 step software breakpoint. */ 1661 if (use_displaced_stepping (gdbarch) 1662 && (tp->control.trap_expected 1663 || (step && gdbarch_software_single_step_p (gdbarch))) 1664 && sig == TARGET_SIGNAL_0 1665 && !current_inferior ()->waiting_for_vfork_done) 1666 { 1667 struct displaced_step_inferior_state *displaced; 1668 1669 if (!displaced_step_prepare (inferior_ptid)) 1670 { 1671 /* Got placed in displaced stepping queue. Will be resumed 1672 later when all the currently queued displaced stepping 1673 requests finish. The thread is not executing at this point, 1674 and the call to set_executing will be made later. But we 1675 need to call set_running here, since from frontend point of view, 1676 the thread is running. */ 1677 set_running (inferior_ptid, 1); 1678 discard_cleanups (old_cleanups); 1679 return; 1680 } 1681 1682 displaced = get_displaced_stepping_state (ptid_get_pid (inferior_ptid)); 1683 step = gdbarch_displaced_step_hw_singlestep (gdbarch, 1684 displaced->step_closure); 1685 } 1686 1687 /* Do we need to do it the hard way, w/temp breakpoints? */ 1688 else if (step) 1689 step = maybe_software_singlestep (gdbarch, pc); 1690 1691 if (should_resume) 1692 { 1693 ptid_t resume_ptid; 1694 1695 /* If STEP is set, it's a request to use hardware stepping 1696 facilities. But in that case, we should never 1697 use singlestep breakpoint. */ 1698 gdb_assert (!(singlestep_breakpoints_inserted_p && step)); 1699 1700 /* Decide the set of threads to ask the target to resume. Start 1701 by assuming everything will be resumed, than narrow the set 1702 by applying increasingly restricting conditions. */ 1703 1704 /* By default, resume all threads of all processes. */ 1705 resume_ptid = RESUME_ALL; 1706 1707 /* Maybe resume only all threads of the current process. */ 1708 if (!sched_multi && target_supports_multi_process ()) 1709 { 1710 resume_ptid = pid_to_ptid (ptid_get_pid (inferior_ptid)); 1711 } 1712 1713 /* Maybe resume a single thread after all. */ 1714 if (singlestep_breakpoints_inserted_p 1715 && stepping_past_singlestep_breakpoint) 1716 { 1717 /* The situation here is as follows. In thread T1 we wanted to 1718 single-step. Lacking hardware single-stepping we've 1719 set breakpoint at the PC of the next instruction -- call it 1720 P. After resuming, we've hit that breakpoint in thread T2. 1721 Now we've removed original breakpoint, inserted breakpoint 1722 at P+1, and try to step to advance T2 past breakpoint. 1723 We need to step only T2, as if T1 is allowed to freely run, 1724 it can run past P, and if other threads are allowed to run, 1725 they can hit breakpoint at P+1, and nested hits of single-step 1726 breakpoints is not something we'd want -- that's complicated 1727 to support, and has no value. */ 1728 resume_ptid = inferior_ptid; 1729 } 1730 else if ((step || singlestep_breakpoints_inserted_p) 1731 && tp->control.trap_expected) 1732 { 1733 /* We're allowing a thread to run past a breakpoint it has 1734 hit, by single-stepping the thread with the breakpoint 1735 removed. In which case, we need to single-step only this 1736 thread, and keep others stopped, as they can miss this 1737 breakpoint if allowed to run. 1738 1739 The current code actually removes all breakpoints when 1740 doing this, not just the one being stepped over, so if we 1741 let other threads run, we can actually miss any 1742 breakpoint, not just the one at PC. */ 1743 resume_ptid = inferior_ptid; 1744 } 1745 else if (non_stop) 1746 { 1747 /* With non-stop mode on, threads are always handled 1748 individually. */ 1749 resume_ptid = inferior_ptid; 1750 } 1751 else if ((scheduler_mode == schedlock_on) 1752 || (scheduler_mode == schedlock_step 1753 && (step || singlestep_breakpoints_inserted_p))) 1754 { 1755 /* User-settable 'scheduler' mode requires solo thread resume. */ 1756 resume_ptid = inferior_ptid; 1757 } 1758 1759 if (gdbarch_cannot_step_breakpoint (gdbarch)) 1760 { 1761 /* Most targets can step a breakpoint instruction, thus 1762 executing it normally. But if this one cannot, just 1763 continue and we will hit it anyway. */ 1764 if (step && breakpoint_inserted_here_p (aspace, pc)) 1765 step = 0; 1766 } 1767 1768 if (debug_displaced 1769 && use_displaced_stepping (gdbarch) 1770 && tp->control.trap_expected) 1771 { 1772 struct regcache *resume_regcache = get_thread_regcache (resume_ptid); 1773 struct gdbarch *resume_gdbarch = get_regcache_arch (resume_regcache); 1774 CORE_ADDR actual_pc = regcache_read_pc (resume_regcache); 1775 gdb_byte buf[4]; 1776 1777 fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ", 1778 paddress (resume_gdbarch, actual_pc)); 1779 read_memory (actual_pc, buf, sizeof (buf)); 1780 displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf)); 1781 } 1782 1783 /* Install inferior's terminal modes. */ 1784 target_terminal_inferior (); 1785 1786 /* Avoid confusing the next resume, if the next stop/resume 1787 happens to apply to another thread. */ 1788 tp->suspend.stop_signal = TARGET_SIGNAL_0; 1789 1790 target_resume (resume_ptid, step, sig); 1791 } 1792 1793 discard_cleanups (old_cleanups); 1794 } 1795 1796 /* Proceeding. */ 1797 1798 /* Clear out all variables saying what to do when inferior is continued. 1799 First do this, then set the ones you want, then call `proceed'. */ 1800 1801 static void 1802 clear_proceed_status_thread (struct thread_info *tp) 1803 { 1804 if (debug_infrun) 1805 fprintf_unfiltered (gdb_stdlog, 1806 "infrun: clear_proceed_status_thread (%s)\n", 1807 target_pid_to_str (tp->ptid)); 1808 1809 tp->control.trap_expected = 0; 1810 tp->control.step_range_start = 0; 1811 tp->control.step_range_end = 0; 1812 tp->control.step_frame_id = null_frame_id; 1813 tp->control.step_stack_frame_id = null_frame_id; 1814 tp->control.step_over_calls = STEP_OVER_UNDEBUGGABLE; 1815 tp->stop_requested = 0; 1816 1817 tp->control.stop_step = 0; 1818 1819 tp->control.proceed_to_finish = 0; 1820 1821 /* Discard any remaining commands or status from previous stop. */ 1822 bpstat_clear (&tp->control.stop_bpstat); 1823 } 1824 1825 static int 1826 clear_proceed_status_callback (struct thread_info *tp, void *data) 1827 { 1828 if (is_exited (tp->ptid)) 1829 return 0; 1830 1831 clear_proceed_status_thread (tp); 1832 return 0; 1833 } 1834 1835 void 1836 clear_proceed_status (void) 1837 { 1838 if (!non_stop) 1839 { 1840 /* In all-stop mode, delete the per-thread status of all 1841 threads, even if inferior_ptid is null_ptid, there may be 1842 threads on the list. E.g., we may be launching a new 1843 process, while selecting the executable. */ 1844 iterate_over_threads (clear_proceed_status_callback, NULL); 1845 } 1846 1847 if (!ptid_equal (inferior_ptid, null_ptid)) 1848 { 1849 struct inferior *inferior; 1850 1851 if (non_stop) 1852 { 1853 /* If in non-stop mode, only delete the per-thread status of 1854 the current thread. */ 1855 clear_proceed_status_thread (inferior_thread ()); 1856 } 1857 1858 inferior = current_inferior (); 1859 inferior->control.stop_soon = NO_STOP_QUIETLY; 1860 } 1861 1862 stop_after_trap = 0; 1863 1864 observer_notify_about_to_proceed (); 1865 1866 if (stop_registers) 1867 { 1868 regcache_xfree (stop_registers); 1869 stop_registers = NULL; 1870 } 1871 } 1872 1873 /* Check the current thread against the thread that reported the most recent 1874 event. If a step-over is required return TRUE and set the current thread 1875 to the old thread. Otherwise return FALSE. 1876 1877 This should be suitable for any targets that support threads. */ 1878 1879 static int 1880 prepare_to_proceed (int step) 1881 { 1882 ptid_t wait_ptid; 1883 struct target_waitstatus wait_status; 1884 int schedlock_enabled; 1885 1886 /* With non-stop mode on, threads are always handled individually. */ 1887 gdb_assert (! non_stop); 1888 1889 /* Get the last target status returned by target_wait(). */ 1890 get_last_target_status (&wait_ptid, &wait_status); 1891 1892 /* Make sure we were stopped at a breakpoint. */ 1893 if (wait_status.kind != TARGET_WAITKIND_STOPPED 1894 || (wait_status.value.sig != TARGET_SIGNAL_TRAP 1895 && wait_status.value.sig != TARGET_SIGNAL_ILL 1896 && wait_status.value.sig != TARGET_SIGNAL_SEGV 1897 && wait_status.value.sig != TARGET_SIGNAL_EMT)) 1898 { 1899 return 0; 1900 } 1901 1902 schedlock_enabled = (scheduler_mode == schedlock_on 1903 || (scheduler_mode == schedlock_step 1904 && step)); 1905 1906 /* Don't switch over to WAIT_PTID if scheduler locking is on. */ 1907 if (schedlock_enabled) 1908 return 0; 1909 1910 /* Don't switch over if we're about to resume some other process 1911 other than WAIT_PTID's, and schedule-multiple is off. */ 1912 if (!sched_multi 1913 && ptid_get_pid (wait_ptid) != ptid_get_pid (inferior_ptid)) 1914 return 0; 1915 1916 /* Switched over from WAIT_PID. */ 1917 if (!ptid_equal (wait_ptid, minus_one_ptid) 1918 && !ptid_equal (inferior_ptid, wait_ptid)) 1919 { 1920 struct regcache *regcache = get_thread_regcache (wait_ptid); 1921 1922 if (breakpoint_here_p (get_regcache_aspace (regcache), 1923 regcache_read_pc (regcache))) 1924 { 1925 /* If stepping, remember current thread to switch back to. */ 1926 if (step) 1927 deferred_step_ptid = inferior_ptid; 1928 1929 /* Switch back to WAIT_PID thread. */ 1930 switch_to_thread (wait_ptid); 1931 1932 /* We return 1 to indicate that there is a breakpoint here, 1933 so we need to step over it before continuing to avoid 1934 hitting it straight away. */ 1935 return 1; 1936 } 1937 } 1938 1939 return 0; 1940 } 1941 1942 /* Basic routine for continuing the program in various fashions. 1943 1944 ADDR is the address to resume at, or -1 for resume where stopped. 1945 SIGGNAL is the signal to give it, or 0 for none, 1946 or -1 for act according to how it stopped. 1947 STEP is nonzero if should trap after one instruction. 1948 -1 means return after that and print nothing. 1949 You should probably set various step_... variables 1950 before calling here, if you are stepping. 1951 1952 You should call clear_proceed_status before calling proceed. */ 1953 1954 void 1955 proceed (CORE_ADDR addr, enum target_signal siggnal, int step) 1956 { 1957 struct regcache *regcache; 1958 struct gdbarch *gdbarch; 1959 struct thread_info *tp; 1960 CORE_ADDR pc; 1961 struct address_space *aspace; 1962 int oneproc = 0; 1963 1964 /* If we're stopped at a fork/vfork, follow the branch set by the 1965 "set follow-fork-mode" command; otherwise, we'll just proceed 1966 resuming the current thread. */ 1967 if (!follow_fork ()) 1968 { 1969 /* The target for some reason decided not to resume. */ 1970 normal_stop (); 1971 return; 1972 } 1973 1974 regcache = get_current_regcache (); 1975 gdbarch = get_regcache_arch (regcache); 1976 aspace = get_regcache_aspace (regcache); 1977 pc = regcache_read_pc (regcache); 1978 1979 if (step > 0) 1980 step_start_function = find_pc_function (pc); 1981 if (step < 0) 1982 stop_after_trap = 1; 1983 1984 if (addr == (CORE_ADDR) -1) 1985 { 1986 if (pc == stop_pc && breakpoint_here_p (aspace, pc) 1987 && execution_direction != EXEC_REVERSE) 1988 /* There is a breakpoint at the address we will resume at, 1989 step one instruction before inserting breakpoints so that 1990 we do not stop right away (and report a second hit at this 1991 breakpoint). 1992 1993 Note, we don't do this in reverse, because we won't 1994 actually be executing the breakpoint insn anyway. 1995 We'll be (un-)executing the previous instruction. */ 1996 1997 oneproc = 1; 1998 else if (gdbarch_single_step_through_delay_p (gdbarch) 1999 && gdbarch_single_step_through_delay (gdbarch, 2000 get_current_frame ())) 2001 /* We stepped onto an instruction that needs to be stepped 2002 again before re-inserting the breakpoint, do so. */ 2003 oneproc = 1; 2004 } 2005 else 2006 { 2007 regcache_write_pc (regcache, addr); 2008 } 2009 2010 if (debug_infrun) 2011 fprintf_unfiltered (gdb_stdlog, 2012 "infrun: proceed (addr=%s, signal=%d, step=%d)\n", 2013 paddress (gdbarch, addr), siggnal, step); 2014 2015 if (non_stop) 2016 /* In non-stop, each thread is handled individually. The context 2017 must already be set to the right thread here. */ 2018 ; 2019 else 2020 { 2021 /* In a multi-threaded task we may select another thread and 2022 then continue or step. 2023 2024 But if the old thread was stopped at a breakpoint, it will 2025 immediately cause another breakpoint stop without any 2026 execution (i.e. it will report a breakpoint hit incorrectly). 2027 So we must step over it first. 2028 2029 prepare_to_proceed checks the current thread against the 2030 thread that reported the most recent event. If a step-over 2031 is required it returns TRUE and sets the current thread to 2032 the old thread. */ 2033 if (prepare_to_proceed (step)) 2034 oneproc = 1; 2035 } 2036 2037 /* prepare_to_proceed may change the current thread. */ 2038 tp = inferior_thread (); 2039 2040 if (oneproc) 2041 { 2042 tp->control.trap_expected = 1; 2043 /* If displaced stepping is enabled, we can step over the 2044 breakpoint without hitting it, so leave all breakpoints 2045 inserted. Otherwise we need to disable all breakpoints, step 2046 one instruction, and then re-add them when that step is 2047 finished. */ 2048 if (!use_displaced_stepping (gdbarch)) 2049 remove_breakpoints (); 2050 } 2051 2052 /* We can insert breakpoints if we're not trying to step over one, 2053 or if we are stepping over one but we're using displaced stepping 2054 to do so. */ 2055 if (! tp->control.trap_expected || use_displaced_stepping (gdbarch)) 2056 insert_breakpoints (); 2057 2058 if (!non_stop) 2059 { 2060 /* Pass the last stop signal to the thread we're resuming, 2061 irrespective of whether the current thread is the thread that 2062 got the last event or not. This was historically GDB's 2063 behaviour before keeping a stop_signal per thread. */ 2064 2065 struct thread_info *last_thread; 2066 ptid_t last_ptid; 2067 struct target_waitstatus last_status; 2068 2069 get_last_target_status (&last_ptid, &last_status); 2070 if (!ptid_equal (inferior_ptid, last_ptid) 2071 && !ptid_equal (last_ptid, null_ptid) 2072 && !ptid_equal (last_ptid, minus_one_ptid)) 2073 { 2074 last_thread = find_thread_ptid (last_ptid); 2075 if (last_thread) 2076 { 2077 tp->suspend.stop_signal = last_thread->suspend.stop_signal; 2078 last_thread->suspend.stop_signal = TARGET_SIGNAL_0; 2079 } 2080 } 2081 } 2082 2083 if (siggnal != TARGET_SIGNAL_DEFAULT) 2084 tp->suspend.stop_signal = siggnal; 2085 /* If this signal should not be seen by program, 2086 give it zero. Used for debugging signals. */ 2087 else if (!signal_program[tp->suspend.stop_signal]) 2088 tp->suspend.stop_signal = TARGET_SIGNAL_0; 2089 2090 annotate_starting (); 2091 2092 /* Make sure that output from GDB appears before output from the 2093 inferior. */ 2094 gdb_flush (gdb_stdout); 2095 2096 /* Refresh prev_pc value just prior to resuming. This used to be 2097 done in stop_stepping, however, setting prev_pc there did not handle 2098 scenarios such as inferior function calls or returning from 2099 a function via the return command. In those cases, the prev_pc 2100 value was not set properly for subsequent commands. The prev_pc value 2101 is used to initialize the starting line number in the ecs. With an 2102 invalid value, the gdb next command ends up stopping at the position 2103 represented by the next line table entry past our start position. 2104 On platforms that generate one line table entry per line, this 2105 is not a problem. However, on the ia64, the compiler generates 2106 extraneous line table entries that do not increase the line number. 2107 When we issue the gdb next command on the ia64 after an inferior call 2108 or a return command, we often end up a few instructions forward, still 2109 within the original line we started. 2110 2111 An attempt was made to refresh the prev_pc at the same time the 2112 execution_control_state is initialized (for instance, just before 2113 waiting for an inferior event). But this approach did not work 2114 because of platforms that use ptrace, where the pc register cannot 2115 be read unless the inferior is stopped. At that point, we are not 2116 guaranteed the inferior is stopped and so the regcache_read_pc() call 2117 can fail. Setting the prev_pc value here ensures the value is updated 2118 correctly when the inferior is stopped. */ 2119 tp->prev_pc = regcache_read_pc (get_current_regcache ()); 2120 2121 /* Fill in with reasonable starting values. */ 2122 init_thread_stepping_state (tp); 2123 2124 /* Reset to normal state. */ 2125 init_infwait_state (); 2126 2127 /* Resume inferior. */ 2128 resume (oneproc || step || bpstat_should_step (), tp->suspend.stop_signal); 2129 2130 /* Wait for it to stop (if not standalone) 2131 and in any case decode why it stopped, and act accordingly. */ 2132 /* Do this only if we are not using the event loop, or if the target 2133 does not support asynchronous execution. */ 2134 if (!target_can_async_p ()) 2135 { 2136 wait_for_inferior (0); 2137 normal_stop (); 2138 } 2139 } 2140 2141 2142 /* Start remote-debugging of a machine over a serial link. */ 2143 2144 void 2145 start_remote (int from_tty) 2146 { 2147 struct inferior *inferior; 2148 2149 init_wait_for_inferior (); 2150 inferior = current_inferior (); 2151 inferior->control.stop_soon = STOP_QUIETLY_REMOTE; 2152 2153 /* Always go on waiting for the target, regardless of the mode. */ 2154 /* FIXME: cagney/1999-09-23: At present it isn't possible to 2155 indicate to wait_for_inferior that a target should timeout if 2156 nothing is returned (instead of just blocking). Because of this, 2157 targets expecting an immediate response need to, internally, set 2158 things up so that the target_wait() is forced to eventually 2159 timeout. */ 2160 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to 2161 differentiate to its caller what the state of the target is after 2162 the initial open has been performed. Here we're assuming that 2163 the target has stopped. It should be possible to eventually have 2164 target_open() return to the caller an indication that the target 2165 is currently running and GDB state should be set to the same as 2166 for an async run. */ 2167 wait_for_inferior (0); 2168 2169 /* Now that the inferior has stopped, do any bookkeeping like 2170 loading shared libraries. We want to do this before normal_stop, 2171 so that the displayed frame is up to date. */ 2172 post_create_inferior (¤t_target, from_tty); 2173 2174 normal_stop (); 2175 } 2176 2177 /* Initialize static vars when a new inferior begins. */ 2178 2179 void 2180 init_wait_for_inferior (void) 2181 { 2182 /* These are meaningless until the first time through wait_for_inferior. */ 2183 2184 breakpoint_init_inferior (inf_starting); 2185 2186 clear_proceed_status (); 2187 2188 stepping_past_singlestep_breakpoint = 0; 2189 deferred_step_ptid = null_ptid; 2190 2191 target_last_wait_ptid = minus_one_ptid; 2192 2193 previous_inferior_ptid = null_ptid; 2194 init_infwait_state (); 2195 2196 /* Discard any skipped inlined frames. */ 2197 clear_inline_frame_state (minus_one_ptid); 2198 } 2199 2200 2201 /* This enum encodes possible reasons for doing a target_wait, so that 2202 wfi can call target_wait in one place. (Ultimately the call will be 2203 moved out of the infinite loop entirely.) */ 2204 2205 enum infwait_states 2206 { 2207 infwait_normal_state, 2208 infwait_thread_hop_state, 2209 infwait_step_watch_state, 2210 infwait_nonstep_watch_state 2211 }; 2212 2213 /* The PTID we'll do a target_wait on.*/ 2214 ptid_t waiton_ptid; 2215 2216 /* Current inferior wait state. */ 2217 enum infwait_states infwait_state; 2218 2219 /* Data to be passed around while handling an event. This data is 2220 discarded between events. */ 2221 struct execution_control_state 2222 { 2223 ptid_t ptid; 2224 /* The thread that got the event, if this was a thread event; NULL 2225 otherwise. */ 2226 struct thread_info *event_thread; 2227 2228 struct target_waitstatus ws; 2229 int random_signal; 2230 CORE_ADDR stop_func_start; 2231 CORE_ADDR stop_func_end; 2232 char *stop_func_name; 2233 int new_thread_event; 2234 int wait_some_more; 2235 }; 2236 2237 static void handle_inferior_event (struct execution_control_state *ecs); 2238 2239 static void handle_step_into_function (struct gdbarch *gdbarch, 2240 struct execution_control_state *ecs); 2241 static void handle_step_into_function_backward (struct gdbarch *gdbarch, 2242 struct execution_control_state *ecs); 2243 static void insert_step_resume_breakpoint_at_frame (struct frame_info *); 2244 static void insert_step_resume_breakpoint_at_caller (struct frame_info *); 2245 static void insert_step_resume_breakpoint_at_sal (struct gdbarch *, 2246 struct symtab_and_line , 2247 struct frame_id); 2248 static void insert_longjmp_resume_breakpoint (struct gdbarch *, CORE_ADDR); 2249 static void check_exception_resume (struct execution_control_state *, 2250 struct frame_info *, struct symbol *); 2251 2252 static void stop_stepping (struct execution_control_state *ecs); 2253 static void prepare_to_wait (struct execution_control_state *ecs); 2254 static void keep_going (struct execution_control_state *ecs); 2255 2256 /* Callback for iterate over threads. If the thread is stopped, but 2257 the user/frontend doesn't know about that yet, go through 2258 normal_stop, as if the thread had just stopped now. ARG points at 2259 a ptid. If PTID is MINUS_ONE_PTID, applies to all threads. If 2260 ptid_is_pid(PTID) is true, applies to all threads of the process 2261 pointed at by PTID. Otherwise, apply only to the thread pointed by 2262 PTID. */ 2263 2264 static int 2265 infrun_thread_stop_requested_callback (struct thread_info *info, void *arg) 2266 { 2267 ptid_t ptid = * (ptid_t *) arg; 2268 2269 if ((ptid_equal (info->ptid, ptid) 2270 || ptid_equal (minus_one_ptid, ptid) 2271 || (ptid_is_pid (ptid) 2272 && ptid_get_pid (ptid) == ptid_get_pid (info->ptid))) 2273 && is_running (info->ptid) 2274 && !is_executing (info->ptid)) 2275 { 2276 struct cleanup *old_chain; 2277 struct execution_control_state ecss; 2278 struct execution_control_state *ecs = &ecss; 2279 2280 memset (ecs, 0, sizeof (*ecs)); 2281 2282 old_chain = make_cleanup_restore_current_thread (); 2283 2284 switch_to_thread (info->ptid); 2285 2286 /* Go through handle_inferior_event/normal_stop, so we always 2287 have consistent output as if the stop event had been 2288 reported. */ 2289 ecs->ptid = info->ptid; 2290 ecs->event_thread = find_thread_ptid (info->ptid); 2291 ecs->ws.kind = TARGET_WAITKIND_STOPPED; 2292 ecs->ws.value.sig = TARGET_SIGNAL_0; 2293 2294 handle_inferior_event (ecs); 2295 2296 if (!ecs->wait_some_more) 2297 { 2298 struct thread_info *tp; 2299 2300 normal_stop (); 2301 2302 /* Finish off the continuations. The continations 2303 themselves are responsible for realising the thread 2304 didn't finish what it was supposed to do. */ 2305 tp = inferior_thread (); 2306 do_all_intermediate_continuations_thread (tp); 2307 do_all_continuations_thread (tp); 2308 } 2309 2310 do_cleanups (old_chain); 2311 } 2312 2313 return 0; 2314 } 2315 2316 /* This function is attached as a "thread_stop_requested" observer. 2317 Cleanup local state that assumed the PTID was to be resumed, and 2318 report the stop to the frontend. */ 2319 2320 static void 2321 infrun_thread_stop_requested (ptid_t ptid) 2322 { 2323 struct displaced_step_inferior_state *displaced; 2324 2325 /* PTID was requested to stop. Remove it from the displaced 2326 stepping queue, so we don't try to resume it automatically. */ 2327 2328 for (displaced = displaced_step_inferior_states; 2329 displaced; 2330 displaced = displaced->next) 2331 { 2332 struct displaced_step_request *it, **prev_next_p; 2333 2334 it = displaced->step_request_queue; 2335 prev_next_p = &displaced->step_request_queue; 2336 while (it) 2337 { 2338 if (ptid_match (it->ptid, ptid)) 2339 { 2340 *prev_next_p = it->next; 2341 it->next = NULL; 2342 xfree (it); 2343 } 2344 else 2345 { 2346 prev_next_p = &it->next; 2347 } 2348 2349 it = *prev_next_p; 2350 } 2351 } 2352 2353 iterate_over_threads (infrun_thread_stop_requested_callback, &ptid); 2354 } 2355 2356 static void 2357 infrun_thread_thread_exit (struct thread_info *tp, int silent) 2358 { 2359 if (ptid_equal (target_last_wait_ptid, tp->ptid)) 2360 nullify_last_target_wait_ptid (); 2361 } 2362 2363 /* Callback for iterate_over_threads. */ 2364 2365 static int 2366 delete_step_resume_breakpoint_callback (struct thread_info *info, void *data) 2367 { 2368 if (is_exited (info->ptid)) 2369 return 0; 2370 2371 delete_step_resume_breakpoint (info); 2372 delete_exception_resume_breakpoint (info); 2373 return 0; 2374 } 2375 2376 /* In all-stop, delete the step resume breakpoint of any thread that 2377 had one. In non-stop, delete the step resume breakpoint of the 2378 thread that just stopped. */ 2379 2380 static void 2381 delete_step_thread_step_resume_breakpoint (void) 2382 { 2383 if (!target_has_execution 2384 || ptid_equal (inferior_ptid, null_ptid)) 2385 /* If the inferior has exited, we have already deleted the step 2386 resume breakpoints out of GDB's lists. */ 2387 return; 2388 2389 if (non_stop) 2390 { 2391 /* If in non-stop mode, only delete the step-resume or 2392 longjmp-resume breakpoint of the thread that just stopped 2393 stepping. */ 2394 struct thread_info *tp = inferior_thread (); 2395 2396 delete_step_resume_breakpoint (tp); 2397 delete_exception_resume_breakpoint (tp); 2398 } 2399 else 2400 /* In all-stop mode, delete all step-resume and longjmp-resume 2401 breakpoints of any thread that had them. */ 2402 iterate_over_threads (delete_step_resume_breakpoint_callback, NULL); 2403 } 2404 2405 /* A cleanup wrapper. */ 2406 2407 static void 2408 delete_step_thread_step_resume_breakpoint_cleanup (void *arg) 2409 { 2410 delete_step_thread_step_resume_breakpoint (); 2411 } 2412 2413 /* Pretty print the results of target_wait, for debugging purposes. */ 2414 2415 static void 2416 print_target_wait_results (ptid_t waiton_ptid, ptid_t result_ptid, 2417 const struct target_waitstatus *ws) 2418 { 2419 char *status_string = target_waitstatus_to_string (ws); 2420 struct ui_file *tmp_stream = mem_fileopen (); 2421 char *text; 2422 2423 /* The text is split over several lines because it was getting too long. 2424 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still 2425 output as a unit; we want only one timestamp printed if debug_timestamp 2426 is set. */ 2427 2428 fprintf_unfiltered (tmp_stream, 2429 "infrun: target_wait (%d", PIDGET (waiton_ptid)); 2430 if (PIDGET (waiton_ptid) != -1) 2431 fprintf_unfiltered (tmp_stream, 2432 " [%s]", target_pid_to_str (waiton_ptid)); 2433 fprintf_unfiltered (tmp_stream, ", status) =\n"); 2434 fprintf_unfiltered (tmp_stream, 2435 "infrun: %d [%s],\n", 2436 PIDGET (result_ptid), target_pid_to_str (result_ptid)); 2437 fprintf_unfiltered (tmp_stream, 2438 "infrun: %s\n", 2439 status_string); 2440 2441 text = ui_file_xstrdup (tmp_stream, NULL); 2442 2443 /* This uses %s in part to handle %'s in the text, but also to avoid 2444 a gcc error: the format attribute requires a string literal. */ 2445 fprintf_unfiltered (gdb_stdlog, "%s", text); 2446 2447 xfree (status_string); 2448 xfree (text); 2449 ui_file_delete (tmp_stream); 2450 } 2451 2452 /* Prepare and stabilize the inferior for detaching it. E.g., 2453 detaching while a thread is displaced stepping is a recipe for 2454 crashing it, as nothing would readjust the PC out of the scratch 2455 pad. */ 2456 2457 void 2458 prepare_for_detach (void) 2459 { 2460 struct inferior *inf = current_inferior (); 2461 ptid_t pid_ptid = pid_to_ptid (inf->pid); 2462 struct cleanup *old_chain_1; 2463 struct displaced_step_inferior_state *displaced; 2464 2465 displaced = get_displaced_stepping_state (inf->pid); 2466 2467 /* Is any thread of this process displaced stepping? If not, 2468 there's nothing else to do. */ 2469 if (displaced == NULL || ptid_equal (displaced->step_ptid, null_ptid)) 2470 return; 2471 2472 if (debug_infrun) 2473 fprintf_unfiltered (gdb_stdlog, 2474 "displaced-stepping in-process while detaching"); 2475 2476 old_chain_1 = make_cleanup_restore_integer (&inf->detaching); 2477 inf->detaching = 1; 2478 2479 while (!ptid_equal (displaced->step_ptid, null_ptid)) 2480 { 2481 struct cleanup *old_chain_2; 2482 struct execution_control_state ecss; 2483 struct execution_control_state *ecs; 2484 2485 ecs = &ecss; 2486 memset (ecs, 0, sizeof (*ecs)); 2487 2488 overlay_cache_invalid = 1; 2489 2490 /* We have to invalidate the registers BEFORE calling 2491 target_wait because they can be loaded from the target while 2492 in target_wait. This makes remote debugging a bit more 2493 efficient for those targets that provide critical registers 2494 as part of their normal status mechanism. */ 2495 2496 registers_changed (); 2497 2498 if (deprecated_target_wait_hook) 2499 ecs->ptid = deprecated_target_wait_hook (pid_ptid, &ecs->ws, 0); 2500 else 2501 ecs->ptid = target_wait (pid_ptid, &ecs->ws, 0); 2502 2503 if (debug_infrun) 2504 print_target_wait_results (pid_ptid, ecs->ptid, &ecs->ws); 2505 2506 /* If an error happens while handling the event, propagate GDB's 2507 knowledge of the executing state to the frontend/user running 2508 state. */ 2509 old_chain_2 = make_cleanup (finish_thread_state_cleanup, 2510 &minus_one_ptid); 2511 2512 /* In non-stop mode, each thread is handled individually. 2513 Switch early, so the global state is set correctly for this 2514 thread. */ 2515 if (non_stop 2516 && ecs->ws.kind != TARGET_WAITKIND_EXITED 2517 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED) 2518 context_switch (ecs->ptid); 2519 2520 /* Now figure out what to do with the result of the result. */ 2521 handle_inferior_event (ecs); 2522 2523 /* No error, don't finish the state yet. */ 2524 discard_cleanups (old_chain_2); 2525 2526 /* Breakpoints and watchpoints are not installed on the target 2527 at this point, and signals are passed directly to the 2528 inferior, so this must mean the process is gone. */ 2529 if (!ecs->wait_some_more) 2530 { 2531 discard_cleanups (old_chain_1); 2532 error (_("Program exited while detaching")); 2533 } 2534 } 2535 2536 discard_cleanups (old_chain_1); 2537 } 2538 2539 /* Wait for control to return from inferior to debugger. 2540 2541 If TREAT_EXEC_AS_SIGTRAP is non-zero, then handle EXEC signals 2542 as if they were SIGTRAP signals. This can be useful during 2543 the startup sequence on some targets such as HP/UX, where 2544 we receive an EXEC event instead of the expected SIGTRAP. 2545 2546 If inferior gets a signal, we may decide to start it up again 2547 instead of returning. That is why there is a loop in this function. 2548 When this function actually returns it means the inferior 2549 should be left stopped and GDB should read more commands. */ 2550 2551 void 2552 wait_for_inferior (int treat_exec_as_sigtrap) 2553 { 2554 struct cleanup *old_cleanups; 2555 struct execution_control_state ecss; 2556 struct execution_control_state *ecs; 2557 2558 if (debug_infrun) 2559 fprintf_unfiltered 2560 (gdb_stdlog, "infrun: wait_for_inferior (treat_exec_as_sigtrap=%d)\n", 2561 treat_exec_as_sigtrap); 2562 2563 old_cleanups = 2564 make_cleanup (delete_step_thread_step_resume_breakpoint_cleanup, NULL); 2565 2566 ecs = &ecss; 2567 memset (ecs, 0, sizeof (*ecs)); 2568 2569 /* We'll update this if & when we switch to a new thread. */ 2570 previous_inferior_ptid = inferior_ptid; 2571 2572 while (1) 2573 { 2574 struct cleanup *old_chain; 2575 2576 /* We have to invalidate the registers BEFORE calling target_wait 2577 because they can be loaded from the target while in target_wait. 2578 This makes remote debugging a bit more efficient for those 2579 targets that provide critical registers as part of their normal 2580 status mechanism. */ 2581 2582 overlay_cache_invalid = 1; 2583 registers_changed (); 2584 2585 if (deprecated_target_wait_hook) 2586 ecs->ptid = deprecated_target_wait_hook (waiton_ptid, &ecs->ws, 0); 2587 else 2588 ecs->ptid = target_wait (waiton_ptid, &ecs->ws, 0); 2589 2590 if (debug_infrun) 2591 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws); 2592 2593 if (treat_exec_as_sigtrap && ecs->ws.kind == TARGET_WAITKIND_EXECD) 2594 { 2595 xfree (ecs->ws.value.execd_pathname); 2596 ecs->ws.kind = TARGET_WAITKIND_STOPPED; 2597 ecs->ws.value.sig = TARGET_SIGNAL_TRAP; 2598 } 2599 2600 /* If an error happens while handling the event, propagate GDB's 2601 knowledge of the executing state to the frontend/user running 2602 state. */ 2603 old_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid); 2604 2605 if (ecs->ws.kind == TARGET_WAITKIND_SYSCALL_ENTRY 2606 || ecs->ws.kind == TARGET_WAITKIND_SYSCALL_RETURN) 2607 ecs->ws.value.syscall_number = UNKNOWN_SYSCALL; 2608 2609 /* Now figure out what to do with the result of the result. */ 2610 handle_inferior_event (ecs); 2611 2612 /* No error, don't finish the state yet. */ 2613 discard_cleanups (old_chain); 2614 2615 if (!ecs->wait_some_more) 2616 break; 2617 } 2618 2619 do_cleanups (old_cleanups); 2620 } 2621 2622 /* Asynchronous version of wait_for_inferior. It is called by the 2623 event loop whenever a change of state is detected on the file 2624 descriptor corresponding to the target. It can be called more than 2625 once to complete a single execution command. In such cases we need 2626 to keep the state in a global variable ECSS. If it is the last time 2627 that this function is called for a single execution command, then 2628 report to the user that the inferior has stopped, and do the 2629 necessary cleanups. */ 2630 2631 void 2632 fetch_inferior_event (void *client_data) 2633 { 2634 struct execution_control_state ecss; 2635 struct execution_control_state *ecs = &ecss; 2636 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL); 2637 struct cleanup *ts_old_chain; 2638 int was_sync = sync_execution; 2639 2640 memset (ecs, 0, sizeof (*ecs)); 2641 2642 /* We'll update this if & when we switch to a new thread. */ 2643 previous_inferior_ptid = inferior_ptid; 2644 2645 /* We're handling a live event, so make sure we're doing live 2646 debugging. If we're looking at traceframes while the target is 2647 running, we're going to need to get back to that mode after 2648 handling the event. */ 2649 if (non_stop) 2650 { 2651 make_cleanup_restore_current_traceframe (); 2652 set_current_traceframe (-1); 2653 } 2654 2655 if (non_stop) 2656 /* In non-stop mode, the user/frontend should not notice a thread 2657 switch due to internal events. Make sure we reverse to the 2658 user selected thread and frame after handling the event and 2659 running any breakpoint commands. */ 2660 make_cleanup_restore_current_thread (); 2661 2662 /* We have to invalidate the registers BEFORE calling target_wait 2663 because they can be loaded from the target while in target_wait. 2664 This makes remote debugging a bit more efficient for those 2665 targets that provide critical registers as part of their normal 2666 status mechanism. */ 2667 2668 overlay_cache_invalid = 1; 2669 registers_changed (); 2670 2671 if (deprecated_target_wait_hook) 2672 ecs->ptid = 2673 deprecated_target_wait_hook (waiton_ptid, &ecs->ws, TARGET_WNOHANG); 2674 else 2675 ecs->ptid = target_wait (waiton_ptid, &ecs->ws, TARGET_WNOHANG); 2676 2677 if (debug_infrun) 2678 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws); 2679 2680 if (non_stop 2681 && ecs->ws.kind != TARGET_WAITKIND_IGNORE 2682 && ecs->ws.kind != TARGET_WAITKIND_EXITED 2683 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED) 2684 /* In non-stop mode, each thread is handled individually. Switch 2685 early, so the global state is set correctly for this 2686 thread. */ 2687 context_switch (ecs->ptid); 2688 2689 /* If an error happens while handling the event, propagate GDB's 2690 knowledge of the executing state to the frontend/user running 2691 state. */ 2692 if (!non_stop) 2693 ts_old_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid); 2694 else 2695 ts_old_chain = make_cleanup (finish_thread_state_cleanup, &ecs->ptid); 2696 2697 /* Now figure out what to do with the result of the result. */ 2698 handle_inferior_event (ecs); 2699 2700 if (!ecs->wait_some_more) 2701 { 2702 struct inferior *inf = find_inferior_pid (ptid_get_pid (ecs->ptid)); 2703 2704 delete_step_thread_step_resume_breakpoint (); 2705 2706 /* We may not find an inferior if this was a process exit. */ 2707 if (inf == NULL || inf->control.stop_soon == NO_STOP_QUIETLY) 2708 normal_stop (); 2709 2710 if (target_has_execution 2711 && ecs->ws.kind != TARGET_WAITKIND_EXITED 2712 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED 2713 && ecs->event_thread->step_multi 2714 && ecs->event_thread->control.stop_step) 2715 inferior_event_handler (INF_EXEC_CONTINUE, NULL); 2716 else 2717 inferior_event_handler (INF_EXEC_COMPLETE, NULL); 2718 } 2719 2720 /* No error, don't finish the thread states yet. */ 2721 discard_cleanups (ts_old_chain); 2722 2723 /* Revert thread and frame. */ 2724 do_cleanups (old_chain); 2725 2726 /* If the inferior was in sync execution mode, and now isn't, 2727 restore the prompt. */ 2728 if (was_sync && !sync_execution) 2729 display_gdb_prompt (0); 2730 } 2731 2732 /* Record the frame and location we're currently stepping through. */ 2733 void 2734 set_step_info (struct frame_info *frame, struct symtab_and_line sal) 2735 { 2736 struct thread_info *tp = inferior_thread (); 2737 2738 tp->control.step_frame_id = get_frame_id (frame); 2739 tp->control.step_stack_frame_id = get_stack_frame_id (frame); 2740 2741 tp->current_symtab = sal.symtab; 2742 tp->current_line = sal.line; 2743 } 2744 2745 /* Clear context switchable stepping state. */ 2746 2747 void 2748 init_thread_stepping_state (struct thread_info *tss) 2749 { 2750 tss->stepping_over_breakpoint = 0; 2751 tss->step_after_step_resume_breakpoint = 0; 2752 tss->stepping_through_solib_after_catch = 0; 2753 tss->stepping_through_solib_catchpoints = NULL; 2754 } 2755 2756 /* Return the cached copy of the last pid/waitstatus returned by 2757 target_wait()/deprecated_target_wait_hook(). The data is actually 2758 cached by handle_inferior_event(), which gets called immediately 2759 after target_wait()/deprecated_target_wait_hook(). */ 2760 2761 void 2762 get_last_target_status (ptid_t *ptidp, struct target_waitstatus *status) 2763 { 2764 *ptidp = target_last_wait_ptid; 2765 *status = target_last_waitstatus; 2766 } 2767 2768 void 2769 nullify_last_target_wait_ptid (void) 2770 { 2771 target_last_wait_ptid = minus_one_ptid; 2772 } 2773 2774 /* Switch thread contexts. */ 2775 2776 static void 2777 context_switch (ptid_t ptid) 2778 { 2779 if (debug_infrun) 2780 { 2781 fprintf_unfiltered (gdb_stdlog, "infrun: Switching context from %s ", 2782 target_pid_to_str (inferior_ptid)); 2783 fprintf_unfiltered (gdb_stdlog, "to %s\n", 2784 target_pid_to_str (ptid)); 2785 } 2786 2787 switch_to_thread (ptid); 2788 } 2789 2790 static void 2791 adjust_pc_after_break (struct execution_control_state *ecs) 2792 { 2793 struct regcache *regcache; 2794 struct gdbarch *gdbarch; 2795 struct address_space *aspace; 2796 CORE_ADDR breakpoint_pc; 2797 2798 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If 2799 we aren't, just return. 2800 2801 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not 2802 affected by gdbarch_decr_pc_after_break. Other waitkinds which are 2803 implemented by software breakpoints should be handled through the normal 2804 breakpoint layer. 2805 2806 NOTE drow/2004-01-31: On some targets, breakpoints may generate 2807 different signals (SIGILL or SIGEMT for instance), but it is less 2808 clear where the PC is pointing afterwards. It may not match 2809 gdbarch_decr_pc_after_break. I don't know any specific target that 2810 generates these signals at breakpoints (the code has been in GDB since at 2811 least 1992) so I can not guess how to handle them here. 2812 2813 In earlier versions of GDB, a target with 2814 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a 2815 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any 2816 target with both of these set in GDB history, and it seems unlikely to be 2817 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */ 2818 2819 if (ecs->ws.kind != TARGET_WAITKIND_STOPPED) 2820 return; 2821 2822 if (ecs->ws.value.sig != TARGET_SIGNAL_TRAP) 2823 return; 2824 2825 /* In reverse execution, when a breakpoint is hit, the instruction 2826 under it has already been de-executed. The reported PC always 2827 points at the breakpoint address, so adjusting it further would 2828 be wrong. E.g., consider this case on a decr_pc_after_break == 1 2829 architecture: 2830 2831 B1 0x08000000 : INSN1 2832 B2 0x08000001 : INSN2 2833 0x08000002 : INSN3 2834 PC -> 0x08000003 : INSN4 2835 2836 Say you're stopped at 0x08000003 as above. Reverse continuing 2837 from that point should hit B2 as below. Reading the PC when the 2838 SIGTRAP is reported should read 0x08000001 and INSN2 should have 2839 been de-executed already. 2840 2841 B1 0x08000000 : INSN1 2842 B2 PC -> 0x08000001 : INSN2 2843 0x08000002 : INSN3 2844 0x08000003 : INSN4 2845 2846 We can't apply the same logic as for forward execution, because 2847 we would wrongly adjust the PC to 0x08000000, since there's a 2848 breakpoint at PC - 1. We'd then report a hit on B1, although 2849 INSN1 hadn't been de-executed yet. Doing nothing is the correct 2850 behaviour. */ 2851 if (execution_direction == EXEC_REVERSE) 2852 return; 2853 2854 /* If this target does not decrement the PC after breakpoints, then 2855 we have nothing to do. */ 2856 regcache = get_thread_regcache (ecs->ptid); 2857 gdbarch = get_regcache_arch (regcache); 2858 if (gdbarch_decr_pc_after_break (gdbarch) == 0) 2859 return; 2860 2861 aspace = get_regcache_aspace (regcache); 2862 2863 /* Find the location where (if we've hit a breakpoint) the 2864 breakpoint would be. */ 2865 breakpoint_pc = regcache_read_pc (regcache) 2866 - gdbarch_decr_pc_after_break (gdbarch); 2867 2868 /* Check whether there actually is a software breakpoint inserted at 2869 that location. 2870 2871 If in non-stop mode, a race condition is possible where we've 2872 removed a breakpoint, but stop events for that breakpoint were 2873 already queued and arrive later. To suppress those spurious 2874 SIGTRAPs, we keep a list of such breakpoint locations for a bit, 2875 and retire them after a number of stop events are reported. */ 2876 if (software_breakpoint_inserted_here_p (aspace, breakpoint_pc) 2877 || (non_stop && moribund_breakpoint_here_p (aspace, breakpoint_pc))) 2878 { 2879 struct cleanup *old_cleanups = NULL; 2880 2881 if (RECORD_IS_USED) 2882 old_cleanups = record_gdb_operation_disable_set (); 2883 2884 /* When using hardware single-step, a SIGTRAP is reported for both 2885 a completed single-step and a software breakpoint. Need to 2886 differentiate between the two, as the latter needs adjusting 2887 but the former does not. 2888 2889 The SIGTRAP can be due to a completed hardware single-step only if 2890 - we didn't insert software single-step breakpoints 2891 - the thread to be examined is still the current thread 2892 - this thread is currently being stepped 2893 2894 If any of these events did not occur, we must have stopped due 2895 to hitting a software breakpoint, and have to back up to the 2896 breakpoint address. 2897 2898 As a special case, we could have hardware single-stepped a 2899 software breakpoint. In this case (prev_pc == breakpoint_pc), 2900 we also need to back up to the breakpoint address. */ 2901 2902 if (singlestep_breakpoints_inserted_p 2903 || !ptid_equal (ecs->ptid, inferior_ptid) 2904 || !currently_stepping (ecs->event_thread) 2905 || ecs->event_thread->prev_pc == breakpoint_pc) 2906 regcache_write_pc (regcache, breakpoint_pc); 2907 2908 if (RECORD_IS_USED) 2909 do_cleanups (old_cleanups); 2910 } 2911 } 2912 2913 void 2914 init_infwait_state (void) 2915 { 2916 waiton_ptid = pid_to_ptid (-1); 2917 infwait_state = infwait_normal_state; 2918 } 2919 2920 void 2921 error_is_running (void) 2922 { 2923 error (_("Cannot execute this command while " 2924 "the selected thread is running.")); 2925 } 2926 2927 void 2928 ensure_not_running (void) 2929 { 2930 if (is_running (inferior_ptid)) 2931 error_is_running (); 2932 } 2933 2934 static int 2935 stepped_in_from (struct frame_info *frame, struct frame_id step_frame_id) 2936 { 2937 for (frame = get_prev_frame (frame); 2938 frame != NULL; 2939 frame = get_prev_frame (frame)) 2940 { 2941 if (frame_id_eq (get_frame_id (frame), step_frame_id)) 2942 return 1; 2943 if (get_frame_type (frame) != INLINE_FRAME) 2944 break; 2945 } 2946 2947 return 0; 2948 } 2949 2950 /* Auxiliary function that handles syscall entry/return events. 2951 It returns 1 if the inferior should keep going (and GDB 2952 should ignore the event), or 0 if the event deserves to be 2953 processed. */ 2954 2955 static int 2956 handle_syscall_event (struct execution_control_state *ecs) 2957 { 2958 struct regcache *regcache; 2959 struct gdbarch *gdbarch; 2960 int syscall_number; 2961 2962 if (!ptid_equal (ecs->ptid, inferior_ptid)) 2963 context_switch (ecs->ptid); 2964 2965 regcache = get_thread_regcache (ecs->ptid); 2966 gdbarch = get_regcache_arch (regcache); 2967 syscall_number = gdbarch_get_syscall_number (gdbarch, ecs->ptid); 2968 stop_pc = regcache_read_pc (regcache); 2969 2970 target_last_waitstatus.value.syscall_number = syscall_number; 2971 2972 if (catch_syscall_enabled () > 0 2973 && catching_syscall_number (syscall_number) > 0) 2974 { 2975 if (debug_infrun) 2976 fprintf_unfiltered (gdb_stdlog, "infrun: syscall number = '%d'\n", 2977 syscall_number); 2978 2979 ecs->event_thread->control.stop_bpstat 2980 = bpstat_stop_status (get_regcache_aspace (regcache), 2981 stop_pc, ecs->ptid); 2982 ecs->random_signal 2983 = !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat); 2984 2985 if (!ecs->random_signal) 2986 { 2987 /* Catchpoint hit. */ 2988 ecs->event_thread->suspend.stop_signal = TARGET_SIGNAL_TRAP; 2989 return 0; 2990 } 2991 } 2992 2993 /* If no catchpoint triggered for this, then keep going. */ 2994 ecs->event_thread->suspend.stop_signal = TARGET_SIGNAL_0; 2995 keep_going (ecs); 2996 return 1; 2997 } 2998 2999 /* Given an execution control state that has been freshly filled in 3000 by an event from the inferior, figure out what it means and take 3001 appropriate action. */ 3002 3003 static void 3004 handle_inferior_event (struct execution_control_state *ecs) 3005 { 3006 struct frame_info *frame; 3007 struct gdbarch *gdbarch; 3008 int sw_single_step_trap_p = 0; 3009 int stopped_by_watchpoint; 3010 int stepped_after_stopped_by_watchpoint = 0; 3011 struct symtab_and_line stop_pc_sal; 3012 enum stop_kind stop_soon; 3013 3014 if (ecs->ws.kind == TARGET_WAITKIND_IGNORE) 3015 { 3016 /* We had an event in the inferior, but we are not interested in 3017 handling it at this level. The lower layers have already 3018 done what needs to be done, if anything. 3019 3020 One of the possible circumstances for this is when the 3021 inferior produces output for the console. The inferior has 3022 not stopped, and we are ignoring the event. Another possible 3023 circumstance is any event which the lower level knows will be 3024 reported multiple times without an intervening resume. */ 3025 if (debug_infrun) 3026 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_IGNORE\n"); 3027 prepare_to_wait (ecs); 3028 return; 3029 } 3030 3031 if (ecs->ws.kind != TARGET_WAITKIND_EXITED 3032 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED) 3033 { 3034 struct inferior *inf = find_inferior_pid (ptid_get_pid (ecs->ptid)); 3035 3036 gdb_assert (inf); 3037 stop_soon = inf->control.stop_soon; 3038 } 3039 else 3040 stop_soon = NO_STOP_QUIETLY; 3041 3042 /* Cache the last pid/waitstatus. */ 3043 target_last_wait_ptid = ecs->ptid; 3044 target_last_waitstatus = ecs->ws; 3045 3046 /* Always clear state belonging to the previous time we stopped. */ 3047 stop_stack_dummy = STOP_NONE; 3048 3049 /* If it's a new process, add it to the thread database. */ 3050 3051 ecs->new_thread_event = (!ptid_equal (ecs->ptid, inferior_ptid) 3052 && !ptid_equal (ecs->ptid, minus_one_ptid) 3053 && !in_thread_list (ecs->ptid)); 3054 3055 if (ecs->ws.kind != TARGET_WAITKIND_EXITED 3056 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED && ecs->new_thread_event) 3057 add_thread (ecs->ptid); 3058 3059 ecs->event_thread = find_thread_ptid (ecs->ptid); 3060 3061 /* Dependent on valid ECS->EVENT_THREAD. */ 3062 adjust_pc_after_break (ecs); 3063 3064 /* Dependent on the current PC value modified by adjust_pc_after_break. */ 3065 reinit_frame_cache (); 3066 3067 breakpoint_retire_moribund (); 3068 3069 /* First, distinguish signals caused by the debugger from signals 3070 that have to do with the program's own actions. Note that 3071 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending 3072 on the operating system version. Here we detect when a SIGILL or 3073 SIGEMT is really a breakpoint and change it to SIGTRAP. We do 3074 something similar for SIGSEGV, since a SIGSEGV will be generated 3075 when we're trying to execute a breakpoint instruction on a 3076 non-executable stack. This happens for call dummy breakpoints 3077 for architectures like SPARC that place call dummies on the 3078 stack. */ 3079 if (ecs->ws.kind == TARGET_WAITKIND_STOPPED 3080 && (ecs->ws.value.sig == TARGET_SIGNAL_ILL 3081 || ecs->ws.value.sig == TARGET_SIGNAL_SEGV 3082 || ecs->ws.value.sig == TARGET_SIGNAL_EMT)) 3083 { 3084 struct regcache *regcache = get_thread_regcache (ecs->ptid); 3085 3086 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache), 3087 regcache_read_pc (regcache))) 3088 { 3089 if (debug_infrun) 3090 fprintf_unfiltered (gdb_stdlog, 3091 "infrun: Treating signal as SIGTRAP\n"); 3092 ecs->ws.value.sig = TARGET_SIGNAL_TRAP; 3093 } 3094 } 3095 3096 /* Mark the non-executing threads accordingly. In all-stop, all 3097 threads of all processes are stopped when we get any event 3098 reported. In non-stop mode, only the event thread stops. If 3099 we're handling a process exit in non-stop mode, there's nothing 3100 to do, as threads of the dead process are gone, and threads of 3101 any other process were left running. */ 3102 if (!non_stop) 3103 set_executing (minus_one_ptid, 0); 3104 else if (ecs->ws.kind != TARGET_WAITKIND_SIGNALLED 3105 && ecs->ws.kind != TARGET_WAITKIND_EXITED) 3106 set_executing (inferior_ptid, 0); 3107 3108 switch (infwait_state) 3109 { 3110 case infwait_thread_hop_state: 3111 if (debug_infrun) 3112 fprintf_unfiltered (gdb_stdlog, "infrun: infwait_thread_hop_state\n"); 3113 break; 3114 3115 case infwait_normal_state: 3116 if (debug_infrun) 3117 fprintf_unfiltered (gdb_stdlog, "infrun: infwait_normal_state\n"); 3118 break; 3119 3120 case infwait_step_watch_state: 3121 if (debug_infrun) 3122 fprintf_unfiltered (gdb_stdlog, 3123 "infrun: infwait_step_watch_state\n"); 3124 3125 stepped_after_stopped_by_watchpoint = 1; 3126 break; 3127 3128 case infwait_nonstep_watch_state: 3129 if (debug_infrun) 3130 fprintf_unfiltered (gdb_stdlog, 3131 "infrun: infwait_nonstep_watch_state\n"); 3132 insert_breakpoints (); 3133 3134 /* FIXME-maybe: is this cleaner than setting a flag? Does it 3135 handle things like signals arriving and other things happening 3136 in combination correctly? */ 3137 stepped_after_stopped_by_watchpoint = 1; 3138 break; 3139 3140 default: 3141 internal_error (__FILE__, __LINE__, _("bad switch")); 3142 } 3143 3144 infwait_state = infwait_normal_state; 3145 waiton_ptid = pid_to_ptid (-1); 3146 3147 switch (ecs->ws.kind) 3148 { 3149 case TARGET_WAITKIND_LOADED: 3150 if (debug_infrun) 3151 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_LOADED\n"); 3152 /* Ignore gracefully during startup of the inferior, as it might 3153 be the shell which has just loaded some objects, otherwise 3154 add the symbols for the newly loaded objects. Also ignore at 3155 the beginning of an attach or remote session; we will query 3156 the full list of libraries once the connection is 3157 established. */ 3158 if (stop_soon == NO_STOP_QUIETLY) 3159 { 3160 /* Check for any newly added shared libraries if we're 3161 supposed to be adding them automatically. Switch 3162 terminal for any messages produced by 3163 breakpoint_re_set. */ 3164 target_terminal_ours_for_output (); 3165 /* NOTE: cagney/2003-11-25: Make certain that the target 3166 stack's section table is kept up-to-date. Architectures, 3167 (e.g., PPC64), use the section table to perform 3168 operations such as address => section name and hence 3169 require the table to contain all sections (including 3170 those found in shared libraries). */ 3171 #ifdef SOLIB_ADD 3172 SOLIB_ADD (NULL, 0, ¤t_target, auto_solib_add); 3173 #else 3174 solib_add (NULL, 0, ¤t_target, auto_solib_add); 3175 #endif 3176 target_terminal_inferior (); 3177 3178 /* If requested, stop when the dynamic linker notifies 3179 gdb of events. This allows the user to get control 3180 and place breakpoints in initializer routines for 3181 dynamically loaded objects (among other things). */ 3182 if (stop_on_solib_events) 3183 { 3184 /* Make sure we print "Stopped due to solib-event" in 3185 normal_stop. */ 3186 stop_print_frame = 1; 3187 3188 stop_stepping (ecs); 3189 return; 3190 } 3191 3192 /* NOTE drow/2007-05-11: This might be a good place to check 3193 for "catch load". */ 3194 } 3195 3196 /* If we are skipping through a shell, or through shared library 3197 loading that we aren't interested in, resume the program. If 3198 we're running the program normally, also resume. But stop if 3199 we're attaching or setting up a remote connection. */ 3200 if (stop_soon == STOP_QUIETLY || stop_soon == NO_STOP_QUIETLY) 3201 { 3202 /* Loading of shared libraries might have changed breakpoint 3203 addresses. Make sure new breakpoints are inserted. */ 3204 if (stop_soon == NO_STOP_QUIETLY 3205 && !breakpoints_always_inserted_mode ()) 3206 insert_breakpoints (); 3207 resume (0, TARGET_SIGNAL_0); 3208 prepare_to_wait (ecs); 3209 return; 3210 } 3211 3212 break; 3213 3214 case TARGET_WAITKIND_SPURIOUS: 3215 if (debug_infrun) 3216 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SPURIOUS\n"); 3217 resume (0, TARGET_SIGNAL_0); 3218 prepare_to_wait (ecs); 3219 return; 3220 3221 case TARGET_WAITKIND_EXITED: 3222 if (debug_infrun) 3223 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_EXITED\n"); 3224 inferior_ptid = ecs->ptid; 3225 set_current_inferior (find_inferior_pid (ptid_get_pid (ecs->ptid))); 3226 set_current_program_space (current_inferior ()->pspace); 3227 handle_vfork_child_exec_or_exit (0); 3228 target_terminal_ours (); /* Must do this before mourn anyway. */ 3229 print_exited_reason (ecs->ws.value.integer); 3230 3231 /* Record the exit code in the convenience variable $_exitcode, so 3232 that the user can inspect this again later. */ 3233 set_internalvar_integer (lookup_internalvar ("_exitcode"), 3234 (LONGEST) ecs->ws.value.integer); 3235 3236 /* Also record this in the inferior itself. */ 3237 current_inferior ()->has_exit_code = 1; 3238 current_inferior ()->exit_code = (LONGEST) ecs->ws.value.integer; 3239 3240 gdb_flush (gdb_stdout); 3241 target_mourn_inferior (); 3242 singlestep_breakpoints_inserted_p = 0; 3243 cancel_single_step_breakpoints (); 3244 stop_print_frame = 0; 3245 stop_stepping (ecs); 3246 return; 3247 3248 case TARGET_WAITKIND_SIGNALLED: 3249 if (debug_infrun) 3250 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SIGNALLED\n"); 3251 inferior_ptid = ecs->ptid; 3252 set_current_inferior (find_inferior_pid (ptid_get_pid (ecs->ptid))); 3253 set_current_program_space (current_inferior ()->pspace); 3254 handle_vfork_child_exec_or_exit (0); 3255 stop_print_frame = 0; 3256 target_terminal_ours (); /* Must do this before mourn anyway. */ 3257 3258 /* Note: By definition of TARGET_WAITKIND_SIGNALLED, we shouldn't 3259 reach here unless the inferior is dead. However, for years 3260 target_kill() was called here, which hints that fatal signals aren't 3261 really fatal on some systems. If that's true, then some changes 3262 may be needed. */ 3263 target_mourn_inferior (); 3264 3265 print_signal_exited_reason (ecs->ws.value.sig); 3266 singlestep_breakpoints_inserted_p = 0; 3267 cancel_single_step_breakpoints (); 3268 stop_stepping (ecs); 3269 return; 3270 3271 /* The following are the only cases in which we keep going; 3272 the above cases end in a continue or goto. */ 3273 case TARGET_WAITKIND_FORKED: 3274 case TARGET_WAITKIND_VFORKED: 3275 if (debug_infrun) 3276 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_FORKED\n"); 3277 3278 if (!ptid_equal (ecs->ptid, inferior_ptid)) 3279 { 3280 context_switch (ecs->ptid); 3281 reinit_frame_cache (); 3282 } 3283 3284 /* Immediately detach breakpoints from the child before there's 3285 any chance of letting the user delete breakpoints from the 3286 breakpoint lists. If we don't do this early, it's easy to 3287 leave left over traps in the child, vis: "break foo; catch 3288 fork; c; <fork>; del; c; <child calls foo>". We only follow 3289 the fork on the last `continue', and by that time the 3290 breakpoint at "foo" is long gone from the breakpoint table. 3291 If we vforked, then we don't need to unpatch here, since both 3292 parent and child are sharing the same memory pages; we'll 3293 need to unpatch at follow/detach time instead to be certain 3294 that new breakpoints added between catchpoint hit time and 3295 vfork follow are detached. */ 3296 if (ecs->ws.kind != TARGET_WAITKIND_VFORKED) 3297 { 3298 int child_pid = ptid_get_pid (ecs->ws.value.related_pid); 3299 3300 /* This won't actually modify the breakpoint list, but will 3301 physically remove the breakpoints from the child. */ 3302 detach_breakpoints (child_pid); 3303 } 3304 3305 if (singlestep_breakpoints_inserted_p) 3306 { 3307 /* Pull the single step breakpoints out of the target. */ 3308 remove_single_step_breakpoints (); 3309 singlestep_breakpoints_inserted_p = 0; 3310 } 3311 3312 /* In case the event is caught by a catchpoint, remember that 3313 the event is to be followed at the next resume of the thread, 3314 and not immediately. */ 3315 ecs->event_thread->pending_follow = ecs->ws; 3316 3317 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid)); 3318 3319 ecs->event_thread->control.stop_bpstat 3320 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()), 3321 stop_pc, ecs->ptid); 3322 3323 /* Note that we're interested in knowing the bpstat actually 3324 causes a stop, not just if it may explain the signal. 3325 Software watchpoints, for example, always appear in the 3326 bpstat. */ 3327 ecs->random_signal 3328 = !bpstat_causes_stop (ecs->event_thread->control.stop_bpstat); 3329 3330 /* If no catchpoint triggered for this, then keep going. */ 3331 if (ecs->random_signal) 3332 { 3333 ptid_t parent; 3334 ptid_t child; 3335 int should_resume; 3336 int follow_child 3337 = (follow_fork_mode_string == follow_fork_mode_child); 3338 3339 ecs->event_thread->suspend.stop_signal = TARGET_SIGNAL_0; 3340 3341 should_resume = follow_fork (); 3342 3343 parent = ecs->ptid; 3344 child = ecs->ws.value.related_pid; 3345 3346 /* In non-stop mode, also resume the other branch. */ 3347 if (non_stop && !detach_fork) 3348 { 3349 if (follow_child) 3350 switch_to_thread (parent); 3351 else 3352 switch_to_thread (child); 3353 3354 ecs->event_thread = inferior_thread (); 3355 ecs->ptid = inferior_ptid; 3356 keep_going (ecs); 3357 } 3358 3359 if (follow_child) 3360 switch_to_thread (child); 3361 else 3362 switch_to_thread (parent); 3363 3364 ecs->event_thread = inferior_thread (); 3365 ecs->ptid = inferior_ptid; 3366 3367 if (should_resume) 3368 keep_going (ecs); 3369 else 3370 stop_stepping (ecs); 3371 return; 3372 } 3373 ecs->event_thread->suspend.stop_signal = TARGET_SIGNAL_TRAP; 3374 goto process_event_stop_test; 3375 3376 case TARGET_WAITKIND_VFORK_DONE: 3377 /* Done with the shared memory region. Re-insert breakpoints in 3378 the parent, and keep going. */ 3379 3380 if (debug_infrun) 3381 fprintf_unfiltered (gdb_stdlog, 3382 "infrun: TARGET_WAITKIND_VFORK_DONE\n"); 3383 3384 if (!ptid_equal (ecs->ptid, inferior_ptid)) 3385 context_switch (ecs->ptid); 3386 3387 current_inferior ()->waiting_for_vfork_done = 0; 3388 current_inferior ()->pspace->breakpoints_not_allowed = 0; 3389 /* This also takes care of reinserting breakpoints in the 3390 previously locked inferior. */ 3391 keep_going (ecs); 3392 return; 3393 3394 case TARGET_WAITKIND_EXECD: 3395 if (debug_infrun) 3396 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_EXECD\n"); 3397 3398 if (!ptid_equal (ecs->ptid, inferior_ptid)) 3399 { 3400 context_switch (ecs->ptid); 3401 reinit_frame_cache (); 3402 } 3403 3404 singlestep_breakpoints_inserted_p = 0; 3405 cancel_single_step_breakpoints (); 3406 3407 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid)); 3408 3409 /* Do whatever is necessary to the parent branch of the vfork. */ 3410 handle_vfork_child_exec_or_exit (1); 3411 3412 /* This causes the eventpoints and symbol table to be reset. 3413 Must do this now, before trying to determine whether to 3414 stop. */ 3415 follow_exec (inferior_ptid, ecs->ws.value.execd_pathname); 3416 3417 ecs->event_thread->control.stop_bpstat 3418 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()), 3419 stop_pc, ecs->ptid); 3420 ecs->random_signal 3421 = !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat); 3422 3423 /* Note that this may be referenced from inside 3424 bpstat_stop_status above, through inferior_has_execd. */ 3425 xfree (ecs->ws.value.execd_pathname); 3426 ecs->ws.value.execd_pathname = NULL; 3427 3428 /* If no catchpoint triggered for this, then keep going. */ 3429 if (ecs->random_signal) 3430 { 3431 ecs->event_thread->suspend.stop_signal = TARGET_SIGNAL_0; 3432 keep_going (ecs); 3433 return; 3434 } 3435 ecs->event_thread->suspend.stop_signal = TARGET_SIGNAL_TRAP; 3436 goto process_event_stop_test; 3437 3438 /* Be careful not to try to gather much state about a thread 3439 that's in a syscall. It's frequently a losing proposition. */ 3440 case TARGET_WAITKIND_SYSCALL_ENTRY: 3441 if (debug_infrun) 3442 fprintf_unfiltered (gdb_stdlog, 3443 "infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n"); 3444 /* Getting the current syscall number. */ 3445 if (handle_syscall_event (ecs) != 0) 3446 return; 3447 goto process_event_stop_test; 3448 3449 /* Before examining the threads further, step this thread to 3450 get it entirely out of the syscall. (We get notice of the 3451 event when the thread is just on the verge of exiting a 3452 syscall. Stepping one instruction seems to get it back 3453 into user code.) */ 3454 case TARGET_WAITKIND_SYSCALL_RETURN: 3455 if (debug_infrun) 3456 fprintf_unfiltered (gdb_stdlog, 3457 "infrun: TARGET_WAITKIND_SYSCALL_RETURN\n"); 3458 if (handle_syscall_event (ecs) != 0) 3459 return; 3460 goto process_event_stop_test; 3461 3462 case TARGET_WAITKIND_STOPPED: 3463 if (debug_infrun) 3464 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_STOPPED\n"); 3465 ecs->event_thread->suspend.stop_signal = ecs->ws.value.sig; 3466 break; 3467 3468 case TARGET_WAITKIND_NO_HISTORY: 3469 /* Reverse execution: target ran out of history info. */ 3470 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid)); 3471 print_no_history_reason (); 3472 stop_stepping (ecs); 3473 return; 3474 } 3475 3476 if (ecs->new_thread_event) 3477 { 3478 if (non_stop) 3479 /* Non-stop assumes that the target handles adding new threads 3480 to the thread list. */ 3481 internal_error (__FILE__, __LINE__, 3482 "targets should add new threads to the thread " 3483 "list themselves in non-stop mode."); 3484 3485 /* We may want to consider not doing a resume here in order to 3486 give the user a chance to play with the new thread. It might 3487 be good to make that a user-settable option. */ 3488 3489 /* At this point, all threads are stopped (happens automatically 3490 in either the OS or the native code). Therefore we need to 3491 continue all threads in order to make progress. */ 3492 3493 if (!ptid_equal (ecs->ptid, inferior_ptid)) 3494 context_switch (ecs->ptid); 3495 target_resume (RESUME_ALL, 0, TARGET_SIGNAL_0); 3496 prepare_to_wait (ecs); 3497 return; 3498 } 3499 3500 if (ecs->ws.kind == TARGET_WAITKIND_STOPPED) 3501 { 3502 /* Do we need to clean up the state of a thread that has 3503 completed a displaced single-step? (Doing so usually affects 3504 the PC, so do it here, before we set stop_pc.) */ 3505 displaced_step_fixup (ecs->ptid, 3506 ecs->event_thread->suspend.stop_signal); 3507 3508 /* If we either finished a single-step or hit a breakpoint, but 3509 the user wanted this thread to be stopped, pretend we got a 3510 SIG0 (generic unsignaled stop). */ 3511 3512 if (ecs->event_thread->stop_requested 3513 && ecs->event_thread->suspend.stop_signal == TARGET_SIGNAL_TRAP) 3514 ecs->event_thread->suspend.stop_signal = TARGET_SIGNAL_0; 3515 } 3516 3517 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid)); 3518 3519 if (debug_infrun) 3520 { 3521 struct regcache *regcache = get_thread_regcache (ecs->ptid); 3522 struct gdbarch *gdbarch = get_regcache_arch (regcache); 3523 struct cleanup *old_chain = save_inferior_ptid (); 3524 3525 inferior_ptid = ecs->ptid; 3526 3527 fprintf_unfiltered (gdb_stdlog, "infrun: stop_pc = %s\n", 3528 paddress (gdbarch, stop_pc)); 3529 if (target_stopped_by_watchpoint ()) 3530 { 3531 CORE_ADDR addr; 3532 3533 fprintf_unfiltered (gdb_stdlog, "infrun: stopped by watchpoint\n"); 3534 3535 if (target_stopped_data_address (¤t_target, &addr)) 3536 fprintf_unfiltered (gdb_stdlog, 3537 "infrun: stopped data address = %s\n", 3538 paddress (gdbarch, addr)); 3539 else 3540 fprintf_unfiltered (gdb_stdlog, 3541 "infrun: (no data address available)\n"); 3542 } 3543 3544 do_cleanups (old_chain); 3545 } 3546 3547 if (stepping_past_singlestep_breakpoint) 3548 { 3549 gdb_assert (singlestep_breakpoints_inserted_p); 3550 gdb_assert (ptid_equal (singlestep_ptid, ecs->ptid)); 3551 gdb_assert (!ptid_equal (singlestep_ptid, saved_singlestep_ptid)); 3552 3553 stepping_past_singlestep_breakpoint = 0; 3554 3555 /* We've either finished single-stepping past the single-step 3556 breakpoint, or stopped for some other reason. It would be nice if 3557 we could tell, but we can't reliably. */ 3558 if (ecs->event_thread->suspend.stop_signal == TARGET_SIGNAL_TRAP) 3559 { 3560 if (debug_infrun) 3561 fprintf_unfiltered (gdb_stdlog, 3562 "infrun: stepping_past_" 3563 "singlestep_breakpoint\n"); 3564 /* Pull the single step breakpoints out of the target. */ 3565 remove_single_step_breakpoints (); 3566 singlestep_breakpoints_inserted_p = 0; 3567 3568 ecs->random_signal = 0; 3569 ecs->event_thread->control.trap_expected = 0; 3570 3571 context_switch (saved_singlestep_ptid); 3572 if (deprecated_context_hook) 3573 deprecated_context_hook (pid_to_thread_id (ecs->ptid)); 3574 3575 resume (1, TARGET_SIGNAL_0); 3576 prepare_to_wait (ecs); 3577 return; 3578 } 3579 } 3580 3581 if (!ptid_equal (deferred_step_ptid, null_ptid)) 3582 { 3583 /* In non-stop mode, there's never a deferred_step_ptid set. */ 3584 gdb_assert (!non_stop); 3585 3586 /* If we stopped for some other reason than single-stepping, ignore 3587 the fact that we were supposed to switch back. */ 3588 if (ecs->event_thread->suspend.stop_signal == TARGET_SIGNAL_TRAP) 3589 { 3590 if (debug_infrun) 3591 fprintf_unfiltered (gdb_stdlog, 3592 "infrun: handling deferred step\n"); 3593 3594 /* Pull the single step breakpoints out of the target. */ 3595 if (singlestep_breakpoints_inserted_p) 3596 { 3597 remove_single_step_breakpoints (); 3598 singlestep_breakpoints_inserted_p = 0; 3599 } 3600 3601 /* Note: We do not call context_switch at this point, as the 3602 context is already set up for stepping the original thread. */ 3603 switch_to_thread (deferred_step_ptid); 3604 deferred_step_ptid = null_ptid; 3605 /* Suppress spurious "Switching to ..." message. */ 3606 previous_inferior_ptid = inferior_ptid; 3607 3608 resume (1, TARGET_SIGNAL_0); 3609 prepare_to_wait (ecs); 3610 return; 3611 } 3612 3613 deferred_step_ptid = null_ptid; 3614 } 3615 3616 /* See if a thread hit a thread-specific breakpoint that was meant for 3617 another thread. If so, then step that thread past the breakpoint, 3618 and continue it. */ 3619 3620 if (ecs->event_thread->suspend.stop_signal == TARGET_SIGNAL_TRAP) 3621 { 3622 int thread_hop_needed = 0; 3623 struct address_space *aspace = 3624 get_regcache_aspace (get_thread_regcache (ecs->ptid)); 3625 3626 /* Check if a regular breakpoint has been hit before checking 3627 for a potential single step breakpoint. Otherwise, GDB will 3628 not see this breakpoint hit when stepping onto breakpoints. */ 3629 if (regular_breakpoint_inserted_here_p (aspace, stop_pc)) 3630 { 3631 ecs->random_signal = 0; 3632 if (!breakpoint_thread_match (aspace, stop_pc, ecs->ptid)) 3633 thread_hop_needed = 1; 3634 } 3635 else if (singlestep_breakpoints_inserted_p) 3636 { 3637 /* We have not context switched yet, so this should be true 3638 no matter which thread hit the singlestep breakpoint. */ 3639 gdb_assert (ptid_equal (inferior_ptid, singlestep_ptid)); 3640 if (debug_infrun) 3641 fprintf_unfiltered (gdb_stdlog, "infrun: software single step " 3642 "trap for %s\n", 3643 target_pid_to_str (ecs->ptid)); 3644 3645 ecs->random_signal = 0; 3646 /* The call to in_thread_list is necessary because PTIDs sometimes 3647 change when we go from single-threaded to multi-threaded. If 3648 the singlestep_ptid is still in the list, assume that it is 3649 really different from ecs->ptid. */ 3650 if (!ptid_equal (singlestep_ptid, ecs->ptid) 3651 && in_thread_list (singlestep_ptid)) 3652 { 3653 /* If the PC of the thread we were trying to single-step 3654 has changed, discard this event (which we were going 3655 to ignore anyway), and pretend we saw that thread 3656 trap. This prevents us continuously moving the 3657 single-step breakpoint forward, one instruction at a 3658 time. If the PC has changed, then the thread we were 3659 trying to single-step has trapped or been signalled, 3660 but the event has not been reported to GDB yet. 3661 3662 There might be some cases where this loses signal 3663 information, if a signal has arrived at exactly the 3664 same time that the PC changed, but this is the best 3665 we can do with the information available. Perhaps we 3666 should arrange to report all events for all threads 3667 when they stop, or to re-poll the remote looking for 3668 this particular thread (i.e. temporarily enable 3669 schedlock). */ 3670 3671 CORE_ADDR new_singlestep_pc 3672 = regcache_read_pc (get_thread_regcache (singlestep_ptid)); 3673 3674 if (new_singlestep_pc != singlestep_pc) 3675 { 3676 enum target_signal stop_signal; 3677 3678 if (debug_infrun) 3679 fprintf_unfiltered (gdb_stdlog, "infrun: unexpected thread," 3680 " but expected thread advanced also\n"); 3681 3682 /* The current context still belongs to 3683 singlestep_ptid. Don't swap here, since that's 3684 the context we want to use. Just fudge our 3685 state and continue. */ 3686 stop_signal = ecs->event_thread->suspend.stop_signal; 3687 ecs->event_thread->suspend.stop_signal = TARGET_SIGNAL_0; 3688 ecs->ptid = singlestep_ptid; 3689 ecs->event_thread = find_thread_ptid (ecs->ptid); 3690 ecs->event_thread->suspend.stop_signal = stop_signal; 3691 stop_pc = new_singlestep_pc; 3692 } 3693 else 3694 { 3695 if (debug_infrun) 3696 fprintf_unfiltered (gdb_stdlog, 3697 "infrun: unexpected thread\n"); 3698 3699 thread_hop_needed = 1; 3700 stepping_past_singlestep_breakpoint = 1; 3701 saved_singlestep_ptid = singlestep_ptid; 3702 } 3703 } 3704 } 3705 3706 if (thread_hop_needed) 3707 { 3708 struct regcache *thread_regcache; 3709 int remove_status = 0; 3710 3711 if (debug_infrun) 3712 fprintf_unfiltered (gdb_stdlog, "infrun: thread_hop_needed\n"); 3713 3714 /* Switch context before touching inferior memory, the 3715 previous thread may have exited. */ 3716 if (!ptid_equal (inferior_ptid, ecs->ptid)) 3717 context_switch (ecs->ptid); 3718 3719 /* Saw a breakpoint, but it was hit by the wrong thread. 3720 Just continue. */ 3721 3722 if (singlestep_breakpoints_inserted_p) 3723 { 3724 /* Pull the single step breakpoints out of the target. */ 3725 remove_single_step_breakpoints (); 3726 singlestep_breakpoints_inserted_p = 0; 3727 } 3728 3729 /* If the arch can displace step, don't remove the 3730 breakpoints. */ 3731 thread_regcache = get_thread_regcache (ecs->ptid); 3732 if (!use_displaced_stepping (get_regcache_arch (thread_regcache))) 3733 remove_status = remove_breakpoints (); 3734 3735 /* Did we fail to remove breakpoints? If so, try 3736 to set the PC past the bp. (There's at least 3737 one situation in which we can fail to remove 3738 the bp's: On HP-UX's that use ttrace, we can't 3739 change the address space of a vforking child 3740 process until the child exits (well, okay, not 3741 then either :-) or execs. */ 3742 if (remove_status != 0) 3743 error (_("Cannot step over breakpoint hit in wrong thread")); 3744 else 3745 { /* Single step */ 3746 if (!non_stop) 3747 { 3748 /* Only need to require the next event from this 3749 thread in all-stop mode. */ 3750 waiton_ptid = ecs->ptid; 3751 infwait_state = infwait_thread_hop_state; 3752 } 3753 3754 ecs->event_thread->stepping_over_breakpoint = 1; 3755 keep_going (ecs); 3756 return; 3757 } 3758 } 3759 else if (singlestep_breakpoints_inserted_p) 3760 { 3761 sw_single_step_trap_p = 1; 3762 ecs->random_signal = 0; 3763 } 3764 } 3765 else 3766 ecs->random_signal = 1; 3767 3768 /* See if something interesting happened to the non-current thread. If 3769 so, then switch to that thread. */ 3770 if (!ptid_equal (ecs->ptid, inferior_ptid)) 3771 { 3772 if (debug_infrun) 3773 fprintf_unfiltered (gdb_stdlog, "infrun: context switch\n"); 3774 3775 context_switch (ecs->ptid); 3776 3777 if (deprecated_context_hook) 3778 deprecated_context_hook (pid_to_thread_id (ecs->ptid)); 3779 } 3780 3781 /* At this point, get hold of the now-current thread's frame. */ 3782 frame = get_current_frame (); 3783 gdbarch = get_frame_arch (frame); 3784 3785 if (singlestep_breakpoints_inserted_p) 3786 { 3787 /* Pull the single step breakpoints out of the target. */ 3788 remove_single_step_breakpoints (); 3789 singlestep_breakpoints_inserted_p = 0; 3790 } 3791 3792 if (stepped_after_stopped_by_watchpoint) 3793 stopped_by_watchpoint = 0; 3794 else 3795 stopped_by_watchpoint = watchpoints_triggered (&ecs->ws); 3796 3797 /* If necessary, step over this watchpoint. We'll be back to display 3798 it in a moment. */ 3799 if (stopped_by_watchpoint 3800 && (target_have_steppable_watchpoint 3801 || gdbarch_have_nonsteppable_watchpoint (gdbarch))) 3802 { 3803 /* At this point, we are stopped at an instruction which has 3804 attempted to write to a piece of memory under control of 3805 a watchpoint. The instruction hasn't actually executed 3806 yet. If we were to evaluate the watchpoint expression 3807 now, we would get the old value, and therefore no change 3808 would seem to have occurred. 3809 3810 In order to make watchpoints work `right', we really need 3811 to complete the memory write, and then evaluate the 3812 watchpoint expression. We do this by single-stepping the 3813 target. 3814 3815 It may not be necessary to disable the watchpoint to stop over 3816 it. For example, the PA can (with some kernel cooperation) 3817 single step over a watchpoint without disabling the watchpoint. 3818 3819 It is far more common to need to disable a watchpoint to step 3820 the inferior over it. If we have non-steppable watchpoints, 3821 we must disable the current watchpoint; it's simplest to 3822 disable all watchpoints and breakpoints. */ 3823 int hw_step = 1; 3824 3825 if (!target_have_steppable_watchpoint) 3826 remove_breakpoints (); 3827 /* Single step */ 3828 hw_step = maybe_software_singlestep (gdbarch, stop_pc); 3829 target_resume (ecs->ptid, hw_step, TARGET_SIGNAL_0); 3830 waiton_ptid = ecs->ptid; 3831 if (target_have_steppable_watchpoint) 3832 infwait_state = infwait_step_watch_state; 3833 else 3834 infwait_state = infwait_nonstep_watch_state; 3835 prepare_to_wait (ecs); 3836 return; 3837 } 3838 3839 ecs->stop_func_start = 0; 3840 ecs->stop_func_end = 0; 3841 ecs->stop_func_name = 0; 3842 /* Don't care about return value; stop_func_start and stop_func_name 3843 will both be 0 if it doesn't work. */ 3844 find_pc_partial_function (stop_pc, &ecs->stop_func_name, 3845 &ecs->stop_func_start, &ecs->stop_func_end); 3846 ecs->stop_func_start 3847 += gdbarch_deprecated_function_start_offset (gdbarch); 3848 ecs->event_thread->stepping_over_breakpoint = 0; 3849 bpstat_clear (&ecs->event_thread->control.stop_bpstat); 3850 ecs->event_thread->control.stop_step = 0; 3851 stop_print_frame = 1; 3852 ecs->random_signal = 0; 3853 stopped_by_random_signal = 0; 3854 3855 /* Hide inlined functions starting here, unless we just performed stepi or 3856 nexti. After stepi and nexti, always show the innermost frame (not any 3857 inline function call sites). */ 3858 if (ecs->event_thread->control.step_range_end != 1) 3859 skip_inline_frames (ecs->ptid); 3860 3861 if (ecs->event_thread->suspend.stop_signal == TARGET_SIGNAL_TRAP 3862 && ecs->event_thread->control.trap_expected 3863 && gdbarch_single_step_through_delay_p (gdbarch) 3864 && currently_stepping (ecs->event_thread)) 3865 { 3866 /* We're trying to step off a breakpoint. Turns out that we're 3867 also on an instruction that needs to be stepped multiple 3868 times before it's been fully executing. E.g., architectures 3869 with a delay slot. It needs to be stepped twice, once for 3870 the instruction and once for the delay slot. */ 3871 int step_through_delay 3872 = gdbarch_single_step_through_delay (gdbarch, frame); 3873 3874 if (debug_infrun && step_through_delay) 3875 fprintf_unfiltered (gdb_stdlog, "infrun: step through delay\n"); 3876 if (ecs->event_thread->control.step_range_end == 0 3877 && step_through_delay) 3878 { 3879 /* The user issued a continue when stopped at a breakpoint. 3880 Set up for another trap and get out of here. */ 3881 ecs->event_thread->stepping_over_breakpoint = 1; 3882 keep_going (ecs); 3883 return; 3884 } 3885 else if (step_through_delay) 3886 { 3887 /* The user issued a step when stopped at a breakpoint. 3888 Maybe we should stop, maybe we should not - the delay 3889 slot *might* correspond to a line of source. In any 3890 case, don't decide that here, just set 3891 ecs->stepping_over_breakpoint, making sure we 3892 single-step again before breakpoints are re-inserted. */ 3893 ecs->event_thread->stepping_over_breakpoint = 1; 3894 } 3895 } 3896 3897 /* Look at the cause of the stop, and decide what to do. 3898 The alternatives are: 3899 1) stop_stepping and return; to really stop and return to the debugger, 3900 2) keep_going and return to start up again 3901 (set ecs->event_thread->stepping_over_breakpoint to 1 to single step once) 3902 3) set ecs->random_signal to 1, and the decision between 1 and 2 3903 will be made according to the signal handling tables. */ 3904 3905 if (ecs->event_thread->suspend.stop_signal == TARGET_SIGNAL_TRAP 3906 || stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_NO_SIGSTOP 3907 || stop_soon == STOP_QUIETLY_REMOTE) 3908 { 3909 if (ecs->event_thread->suspend.stop_signal == TARGET_SIGNAL_TRAP 3910 && stop_after_trap) 3911 { 3912 if (debug_infrun) 3913 fprintf_unfiltered (gdb_stdlog, "infrun: stopped\n"); 3914 stop_print_frame = 0; 3915 stop_stepping (ecs); 3916 return; 3917 } 3918 3919 /* This is originated from start_remote(), start_inferior() and 3920 shared libraries hook functions. */ 3921 if (stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_REMOTE) 3922 { 3923 if (debug_infrun) 3924 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n"); 3925 stop_stepping (ecs); 3926 return; 3927 } 3928 3929 /* This originates from attach_command(). We need to overwrite 3930 the stop_signal here, because some kernels don't ignore a 3931 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call. 3932 See more comments in inferior.h. On the other hand, if we 3933 get a non-SIGSTOP, report it to the user - assume the backend 3934 will handle the SIGSTOP if it should show up later. 3935 3936 Also consider that the attach is complete when we see a 3937 SIGTRAP. Some systems (e.g. Windows), and stubs supporting 3938 target extended-remote report it instead of a SIGSTOP 3939 (e.g. gdbserver). We already rely on SIGTRAP being our 3940 signal, so this is no exception. 3941 3942 Also consider that the attach is complete when we see a 3943 TARGET_SIGNAL_0. In non-stop mode, GDB will explicitly tell 3944 the target to stop all threads of the inferior, in case the 3945 low level attach operation doesn't stop them implicitly. If 3946 they weren't stopped implicitly, then the stub will report a 3947 TARGET_SIGNAL_0, meaning: stopped for no particular reason 3948 other than GDB's request. */ 3949 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP 3950 && (ecs->event_thread->suspend.stop_signal == TARGET_SIGNAL_STOP 3951 || ecs->event_thread->suspend.stop_signal == TARGET_SIGNAL_TRAP 3952 || ecs->event_thread->suspend.stop_signal == TARGET_SIGNAL_0)) 3953 { 3954 stop_stepping (ecs); 3955 ecs->event_thread->suspend.stop_signal = TARGET_SIGNAL_0; 3956 return; 3957 } 3958 3959 /* See if there is a breakpoint at the current PC. */ 3960 ecs->event_thread->control.stop_bpstat 3961 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()), 3962 stop_pc, ecs->ptid); 3963 3964 /* Following in case break condition called a 3965 function. */ 3966 stop_print_frame = 1; 3967 3968 /* This is where we handle "moribund" watchpoints. Unlike 3969 software breakpoints traps, hardware watchpoint traps are 3970 always distinguishable from random traps. If no high-level 3971 watchpoint is associated with the reported stop data address 3972 anymore, then the bpstat does not explain the signal --- 3973 simply make sure to ignore it if `stopped_by_watchpoint' is 3974 set. */ 3975 3976 if (debug_infrun 3977 && ecs->event_thread->suspend.stop_signal == TARGET_SIGNAL_TRAP 3978 && !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat) 3979 && stopped_by_watchpoint) 3980 fprintf_unfiltered (gdb_stdlog, 3981 "infrun: no user watchpoint explains " 3982 "watchpoint SIGTRAP, ignoring\n"); 3983 3984 /* NOTE: cagney/2003-03-29: These two checks for a random signal 3985 at one stage in the past included checks for an inferior 3986 function call's call dummy's return breakpoint. The original 3987 comment, that went with the test, read: 3988 3989 ``End of a stack dummy. Some systems (e.g. Sony news) give 3990 another signal besides SIGTRAP, so check here as well as 3991 above.'' 3992 3993 If someone ever tries to get call dummys on a 3994 non-executable stack to work (where the target would stop 3995 with something like a SIGSEGV), then those tests might need 3996 to be re-instated. Given, however, that the tests were only 3997 enabled when momentary breakpoints were not being used, I 3998 suspect that it won't be the case. 3999 4000 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to 4001 be necessary for call dummies on a non-executable stack on 4002 SPARC. */ 4003 4004 if (ecs->event_thread->suspend.stop_signal == TARGET_SIGNAL_TRAP) 4005 ecs->random_signal 4006 = !(bpstat_explains_signal (ecs->event_thread->control.stop_bpstat) 4007 || stopped_by_watchpoint 4008 || ecs->event_thread->control.trap_expected 4009 || (ecs->event_thread->control.step_range_end 4010 && (ecs->event_thread->control.step_resume_breakpoint 4011 == NULL))); 4012 else 4013 { 4014 ecs->random_signal = !bpstat_explains_signal 4015 (ecs->event_thread->control.stop_bpstat); 4016 if (!ecs->random_signal) 4017 ecs->event_thread->suspend.stop_signal = TARGET_SIGNAL_TRAP; 4018 } 4019 } 4020 4021 /* When we reach this point, we've pretty much decided 4022 that the reason for stopping must've been a random 4023 (unexpected) signal. */ 4024 4025 else 4026 ecs->random_signal = 1; 4027 4028 process_event_stop_test: 4029 4030 /* Re-fetch current thread's frame in case we did a 4031 "goto process_event_stop_test" above. */ 4032 frame = get_current_frame (); 4033 gdbarch = get_frame_arch (frame); 4034 4035 /* For the program's own signals, act according to 4036 the signal handling tables. */ 4037 4038 if (ecs->random_signal) 4039 { 4040 /* Signal not for debugging purposes. */ 4041 int printed = 0; 4042 struct inferior *inf = find_inferior_pid (ptid_get_pid (ecs->ptid)); 4043 4044 if (debug_infrun) 4045 fprintf_unfiltered (gdb_stdlog, "infrun: random signal %d\n", 4046 ecs->event_thread->suspend.stop_signal); 4047 4048 stopped_by_random_signal = 1; 4049 4050 if (signal_print[ecs->event_thread->suspend.stop_signal]) 4051 { 4052 printed = 1; 4053 target_terminal_ours_for_output (); 4054 print_signal_received_reason 4055 (ecs->event_thread->suspend.stop_signal); 4056 } 4057 /* Always stop on signals if we're either just gaining control 4058 of the program, or the user explicitly requested this thread 4059 to remain stopped. */ 4060 if (stop_soon != NO_STOP_QUIETLY 4061 || ecs->event_thread->stop_requested 4062 || (!inf->detaching 4063 && signal_stop_state (ecs->event_thread->suspend.stop_signal))) 4064 { 4065 stop_stepping (ecs); 4066 return; 4067 } 4068 /* If not going to stop, give terminal back 4069 if we took it away. */ 4070 else if (printed) 4071 target_terminal_inferior (); 4072 4073 /* Clear the signal if it should not be passed. */ 4074 if (signal_program[ecs->event_thread->suspend.stop_signal] == 0) 4075 ecs->event_thread->suspend.stop_signal = TARGET_SIGNAL_0; 4076 4077 if (ecs->event_thread->prev_pc == stop_pc 4078 && ecs->event_thread->control.trap_expected 4079 && ecs->event_thread->control.step_resume_breakpoint == NULL) 4080 { 4081 /* We were just starting a new sequence, attempting to 4082 single-step off of a breakpoint and expecting a SIGTRAP. 4083 Instead this signal arrives. This signal will take us out 4084 of the stepping range so GDB needs to remember to, when 4085 the signal handler returns, resume stepping off that 4086 breakpoint. */ 4087 /* To simplify things, "continue" is forced to use the same 4088 code paths as single-step - set a breakpoint at the 4089 signal return address and then, once hit, step off that 4090 breakpoint. */ 4091 if (debug_infrun) 4092 fprintf_unfiltered (gdb_stdlog, 4093 "infrun: signal arrived while stepping over " 4094 "breakpoint\n"); 4095 4096 insert_step_resume_breakpoint_at_frame (frame); 4097 ecs->event_thread->step_after_step_resume_breakpoint = 1; 4098 keep_going (ecs); 4099 return; 4100 } 4101 4102 if (ecs->event_thread->control.step_range_end != 0 4103 && ecs->event_thread->suspend.stop_signal != TARGET_SIGNAL_0 4104 && (ecs->event_thread->control.step_range_start <= stop_pc 4105 && stop_pc < ecs->event_thread->control.step_range_end) 4106 && frame_id_eq (get_stack_frame_id (frame), 4107 ecs->event_thread->control.step_stack_frame_id) 4108 && ecs->event_thread->control.step_resume_breakpoint == NULL) 4109 { 4110 /* The inferior is about to take a signal that will take it 4111 out of the single step range. Set a breakpoint at the 4112 current PC (which is presumably where the signal handler 4113 will eventually return) and then allow the inferior to 4114 run free. 4115 4116 Note that this is only needed for a signal delivered 4117 while in the single-step range. Nested signals aren't a 4118 problem as they eventually all return. */ 4119 if (debug_infrun) 4120 fprintf_unfiltered (gdb_stdlog, 4121 "infrun: signal may take us out of " 4122 "single-step range\n"); 4123 4124 insert_step_resume_breakpoint_at_frame (frame); 4125 keep_going (ecs); 4126 return; 4127 } 4128 4129 /* Note: step_resume_breakpoint may be non-NULL. This occures 4130 when either there's a nested signal, or when there's a 4131 pending signal enabled just as the signal handler returns 4132 (leaving the inferior at the step-resume-breakpoint without 4133 actually executing it). Either way continue until the 4134 breakpoint is really hit. */ 4135 keep_going (ecs); 4136 return; 4137 } 4138 4139 /* Handle cases caused by hitting a breakpoint. */ 4140 { 4141 CORE_ADDR jmp_buf_pc; 4142 struct bpstat_what what; 4143 4144 what = bpstat_what (ecs->event_thread->control.stop_bpstat); 4145 4146 if (what.call_dummy) 4147 { 4148 stop_stack_dummy = what.call_dummy; 4149 } 4150 4151 /* If we hit an internal event that triggers symbol changes, the 4152 current frame will be invalidated within bpstat_what (e.g., if 4153 we hit an internal solib event). Re-fetch it. */ 4154 frame = get_current_frame (); 4155 gdbarch = get_frame_arch (frame); 4156 4157 switch (what.main_action) 4158 { 4159 case BPSTAT_WHAT_SET_LONGJMP_RESUME: 4160 /* If we hit the breakpoint at longjmp while stepping, we 4161 install a momentary breakpoint at the target of the 4162 jmp_buf. */ 4163 4164 if (debug_infrun) 4165 fprintf_unfiltered (gdb_stdlog, 4166 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n"); 4167 4168 ecs->event_thread->stepping_over_breakpoint = 1; 4169 4170 if (what.is_longjmp) 4171 { 4172 if (!gdbarch_get_longjmp_target_p (gdbarch) 4173 || !gdbarch_get_longjmp_target (gdbarch, 4174 frame, &jmp_buf_pc)) 4175 { 4176 if (debug_infrun) 4177 fprintf_unfiltered (gdb_stdlog, 4178 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME " 4179 "(!gdbarch_get_longjmp_target)\n"); 4180 keep_going (ecs); 4181 return; 4182 } 4183 4184 /* We're going to replace the current step-resume breakpoint 4185 with a longjmp-resume breakpoint. */ 4186 delete_step_resume_breakpoint (ecs->event_thread); 4187 4188 /* Insert a breakpoint at resume address. */ 4189 insert_longjmp_resume_breakpoint (gdbarch, jmp_buf_pc); 4190 } 4191 else 4192 { 4193 struct symbol *func = get_frame_function (frame); 4194 4195 if (func) 4196 check_exception_resume (ecs, frame, func); 4197 } 4198 keep_going (ecs); 4199 return; 4200 4201 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME: 4202 if (debug_infrun) 4203 fprintf_unfiltered (gdb_stdlog, 4204 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n"); 4205 4206 if (what.is_longjmp) 4207 { 4208 gdb_assert (ecs->event_thread->control.step_resume_breakpoint 4209 != NULL); 4210 delete_step_resume_breakpoint (ecs->event_thread); 4211 } 4212 else 4213 { 4214 /* There are several cases to consider. 4215 4216 1. The initiating frame no longer exists. In this case 4217 we must stop, because the exception has gone too far. 4218 4219 2. The initiating frame exists, and is the same as the 4220 current frame. We stop, because the exception has been 4221 caught. 4222 4223 3. The initiating frame exists and is different from 4224 the current frame. This means the exception has been 4225 caught beneath the initiating frame, so keep going. */ 4226 struct frame_info *init_frame 4227 = frame_find_by_id (ecs->event_thread->initiating_frame); 4228 4229 gdb_assert (ecs->event_thread->control.exception_resume_breakpoint 4230 != NULL); 4231 delete_exception_resume_breakpoint (ecs->event_thread); 4232 4233 if (init_frame) 4234 { 4235 struct frame_id current_id 4236 = get_frame_id (get_current_frame ()); 4237 if (frame_id_eq (current_id, 4238 ecs->event_thread->initiating_frame)) 4239 { 4240 /* Case 2. Fall through. */ 4241 } 4242 else 4243 { 4244 /* Case 3. */ 4245 keep_going (ecs); 4246 return; 4247 } 4248 } 4249 4250 /* For Cases 1 and 2, remove the step-resume breakpoint, 4251 if it exists. */ 4252 delete_step_resume_breakpoint (ecs->event_thread); 4253 } 4254 4255 ecs->event_thread->control.stop_step = 1; 4256 print_end_stepping_range_reason (); 4257 stop_stepping (ecs); 4258 return; 4259 4260 case BPSTAT_WHAT_SINGLE: 4261 if (debug_infrun) 4262 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_SINGLE\n"); 4263 ecs->event_thread->stepping_over_breakpoint = 1; 4264 /* Still need to check other stuff, at least the case 4265 where we are stepping and step out of the right range. */ 4266 break; 4267 4268 case BPSTAT_WHAT_STOP_NOISY: 4269 if (debug_infrun) 4270 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_NOISY\n"); 4271 stop_print_frame = 1; 4272 4273 /* We are about to nuke the step_resume_breakpointt via the 4274 cleanup chain, so no need to worry about it here. */ 4275 4276 stop_stepping (ecs); 4277 return; 4278 4279 case BPSTAT_WHAT_STOP_SILENT: 4280 if (debug_infrun) 4281 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_SILENT\n"); 4282 stop_print_frame = 0; 4283 4284 /* We are about to nuke the step_resume_breakpoin via the 4285 cleanup chain, so no need to worry about it here. */ 4286 4287 stop_stepping (ecs); 4288 return; 4289 4290 case BPSTAT_WHAT_STEP_RESUME: 4291 if (debug_infrun) 4292 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STEP_RESUME\n"); 4293 4294 delete_step_resume_breakpoint (ecs->event_thread); 4295 if (ecs->event_thread->step_after_step_resume_breakpoint) 4296 { 4297 /* Back when the step-resume breakpoint was inserted, we 4298 were trying to single-step off a breakpoint. Go back 4299 to doing that. */ 4300 ecs->event_thread->step_after_step_resume_breakpoint = 0; 4301 ecs->event_thread->stepping_over_breakpoint = 1; 4302 keep_going (ecs); 4303 return; 4304 } 4305 if (stop_pc == ecs->stop_func_start 4306 && execution_direction == EXEC_REVERSE) 4307 { 4308 /* We are stepping over a function call in reverse, and 4309 just hit the step-resume breakpoint at the start 4310 address of the function. Go back to single-stepping, 4311 which should take us back to the function call. */ 4312 ecs->event_thread->stepping_over_breakpoint = 1; 4313 keep_going (ecs); 4314 return; 4315 } 4316 break; 4317 4318 case BPSTAT_WHAT_KEEP_CHECKING: 4319 break; 4320 } 4321 } 4322 4323 /* We come here if we hit a breakpoint but should not 4324 stop for it. Possibly we also were stepping 4325 and should stop for that. So fall through and 4326 test for stepping. But, if not stepping, 4327 do not stop. */ 4328 4329 /* In all-stop mode, if we're currently stepping but have stopped in 4330 some other thread, we need to switch back to the stepped thread. */ 4331 if (!non_stop) 4332 { 4333 struct thread_info *tp; 4334 4335 tp = iterate_over_threads (currently_stepping_or_nexting_callback, 4336 ecs->event_thread); 4337 if (tp) 4338 { 4339 /* However, if the current thread is blocked on some internal 4340 breakpoint, and we simply need to step over that breakpoint 4341 to get it going again, do that first. */ 4342 if ((ecs->event_thread->control.trap_expected 4343 && ecs->event_thread->suspend.stop_signal != TARGET_SIGNAL_TRAP) 4344 || ecs->event_thread->stepping_over_breakpoint) 4345 { 4346 keep_going (ecs); 4347 return; 4348 } 4349 4350 /* If the stepping thread exited, then don't try to switch 4351 back and resume it, which could fail in several different 4352 ways depending on the target. Instead, just keep going. 4353 4354 We can find a stepping dead thread in the thread list in 4355 two cases: 4356 4357 - The target supports thread exit events, and when the 4358 target tries to delete the thread from the thread list, 4359 inferior_ptid pointed at the exiting thread. In such 4360 case, calling delete_thread does not really remove the 4361 thread from the list; instead, the thread is left listed, 4362 with 'exited' state. 4363 4364 - The target's debug interface does not support thread 4365 exit events, and so we have no idea whatsoever if the 4366 previously stepping thread is still alive. For that 4367 reason, we need to synchronously query the target 4368 now. */ 4369 if (is_exited (tp->ptid) 4370 || !target_thread_alive (tp->ptid)) 4371 { 4372 if (debug_infrun) 4373 fprintf_unfiltered (gdb_stdlog, 4374 "infrun: not switching back to " 4375 "stepped thread, it has vanished\n"); 4376 4377 delete_thread (tp->ptid); 4378 keep_going (ecs); 4379 return; 4380 } 4381 4382 /* Otherwise, we no longer expect a trap in the current thread. 4383 Clear the trap_expected flag before switching back -- this is 4384 what keep_going would do as well, if we called it. */ 4385 ecs->event_thread->control.trap_expected = 0; 4386 4387 if (debug_infrun) 4388 fprintf_unfiltered (gdb_stdlog, 4389 "infrun: switching back to stepped thread\n"); 4390 4391 ecs->event_thread = tp; 4392 ecs->ptid = tp->ptid; 4393 context_switch (ecs->ptid); 4394 keep_going (ecs); 4395 return; 4396 } 4397 } 4398 4399 /* Are we stepping to get the inferior out of the dynamic linker's 4400 hook (and possibly the dld itself) after catching a shlib 4401 event? */ 4402 if (ecs->event_thread->stepping_through_solib_after_catch) 4403 { 4404 #if defined(SOLIB_ADD) 4405 /* Have we reached our destination? If not, keep going. */ 4406 if (SOLIB_IN_DYNAMIC_LINKER (PIDGET (ecs->ptid), stop_pc)) 4407 { 4408 if (debug_infrun) 4409 fprintf_unfiltered (gdb_stdlog, 4410 "infrun: stepping in dynamic linker\n"); 4411 ecs->event_thread->stepping_over_breakpoint = 1; 4412 keep_going (ecs); 4413 return; 4414 } 4415 #endif 4416 if (debug_infrun) 4417 fprintf_unfiltered (gdb_stdlog, "infrun: step past dynamic linker\n"); 4418 /* Else, stop and report the catchpoint(s) whose triggering 4419 caused us to begin stepping. */ 4420 ecs->event_thread->stepping_through_solib_after_catch = 0; 4421 bpstat_clear (&ecs->event_thread->control.stop_bpstat); 4422 ecs->event_thread->control.stop_bpstat 4423 = bpstat_copy (ecs->event_thread->stepping_through_solib_catchpoints); 4424 bpstat_clear (&ecs->event_thread->stepping_through_solib_catchpoints); 4425 stop_print_frame = 1; 4426 stop_stepping (ecs); 4427 return; 4428 } 4429 4430 if (ecs->event_thread->control.step_resume_breakpoint) 4431 { 4432 if (debug_infrun) 4433 fprintf_unfiltered (gdb_stdlog, 4434 "infrun: step-resume breakpoint is inserted\n"); 4435 4436 /* Having a step-resume breakpoint overrides anything 4437 else having to do with stepping commands until 4438 that breakpoint is reached. */ 4439 keep_going (ecs); 4440 return; 4441 } 4442 4443 if (ecs->event_thread->control.step_range_end == 0) 4444 { 4445 if (debug_infrun) 4446 fprintf_unfiltered (gdb_stdlog, "infrun: no stepping, continue\n"); 4447 /* Likewise if we aren't even stepping. */ 4448 keep_going (ecs); 4449 return; 4450 } 4451 4452 /* Re-fetch current thread's frame in case the code above caused 4453 the frame cache to be re-initialized, making our FRAME variable 4454 a dangling pointer. */ 4455 frame = get_current_frame (); 4456 gdbarch = get_frame_arch (frame); 4457 4458 /* If stepping through a line, keep going if still within it. 4459 4460 Note that step_range_end is the address of the first instruction 4461 beyond the step range, and NOT the address of the last instruction 4462 within it! 4463 4464 Note also that during reverse execution, we may be stepping 4465 through a function epilogue and therefore must detect when 4466 the current-frame changes in the middle of a line. */ 4467 4468 if (stop_pc >= ecs->event_thread->control.step_range_start 4469 && stop_pc < ecs->event_thread->control.step_range_end 4470 && (execution_direction != EXEC_REVERSE 4471 || frame_id_eq (get_frame_id (frame), 4472 ecs->event_thread->control.step_frame_id))) 4473 { 4474 if (debug_infrun) 4475 fprintf_unfiltered 4476 (gdb_stdlog, "infrun: stepping inside range [%s-%s]\n", 4477 paddress (gdbarch, ecs->event_thread->control.step_range_start), 4478 paddress (gdbarch, ecs->event_thread->control.step_range_end)); 4479 4480 /* When stepping backward, stop at beginning of line range 4481 (unless it's the function entry point, in which case 4482 keep going back to the call point). */ 4483 if (stop_pc == ecs->event_thread->control.step_range_start 4484 && stop_pc != ecs->stop_func_start 4485 && execution_direction == EXEC_REVERSE) 4486 { 4487 ecs->event_thread->control.stop_step = 1; 4488 print_end_stepping_range_reason (); 4489 stop_stepping (ecs); 4490 } 4491 else 4492 keep_going (ecs); 4493 4494 return; 4495 } 4496 4497 /* We stepped out of the stepping range. */ 4498 4499 /* If we are stepping at the source level and entered the runtime 4500 loader dynamic symbol resolution code... 4501 4502 EXEC_FORWARD: we keep on single stepping until we exit the run 4503 time loader code and reach the callee's address. 4504 4505 EXEC_REVERSE: we've already executed the callee (backward), and 4506 the runtime loader code is handled just like any other 4507 undebuggable function call. Now we need only keep stepping 4508 backward through the trampoline code, and that's handled further 4509 down, so there is nothing for us to do here. */ 4510 4511 if (execution_direction != EXEC_REVERSE 4512 && ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE 4513 && in_solib_dynsym_resolve_code (stop_pc)) 4514 { 4515 CORE_ADDR pc_after_resolver = 4516 gdbarch_skip_solib_resolver (gdbarch, stop_pc); 4517 4518 if (debug_infrun) 4519 fprintf_unfiltered (gdb_stdlog, 4520 "infrun: stepped into dynsym resolve code\n"); 4521 4522 if (pc_after_resolver) 4523 { 4524 /* Set up a step-resume breakpoint at the address 4525 indicated by SKIP_SOLIB_RESOLVER. */ 4526 struct symtab_and_line sr_sal; 4527 4528 init_sal (&sr_sal); 4529 sr_sal.pc = pc_after_resolver; 4530 sr_sal.pspace = get_frame_program_space (frame); 4531 4532 insert_step_resume_breakpoint_at_sal (gdbarch, 4533 sr_sal, null_frame_id); 4534 } 4535 4536 keep_going (ecs); 4537 return; 4538 } 4539 4540 if (ecs->event_thread->control.step_range_end != 1 4541 && (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE 4542 || ecs->event_thread->control.step_over_calls == STEP_OVER_ALL) 4543 && get_frame_type (frame) == SIGTRAMP_FRAME) 4544 { 4545 if (debug_infrun) 4546 fprintf_unfiltered (gdb_stdlog, 4547 "infrun: stepped into signal trampoline\n"); 4548 /* The inferior, while doing a "step" or "next", has ended up in 4549 a signal trampoline (either by a signal being delivered or by 4550 the signal handler returning). Just single-step until the 4551 inferior leaves the trampoline (either by calling the handler 4552 or returning). */ 4553 keep_going (ecs); 4554 return; 4555 } 4556 4557 /* Check for subroutine calls. The check for the current frame 4558 equalling the step ID is not necessary - the check of the 4559 previous frame's ID is sufficient - but it is a common case and 4560 cheaper than checking the previous frame's ID. 4561 4562 NOTE: frame_id_eq will never report two invalid frame IDs as 4563 being equal, so to get into this block, both the current and 4564 previous frame must have valid frame IDs. */ 4565 /* The outer_frame_id check is a heuristic to detect stepping 4566 through startup code. If we step over an instruction which 4567 sets the stack pointer from an invalid value to a valid value, 4568 we may detect that as a subroutine call from the mythical 4569 "outermost" function. This could be fixed by marking 4570 outermost frames as !stack_p,code_p,special_p. Then the 4571 initial outermost frame, before sp was valid, would 4572 have code_addr == &_start. See the comment in frame_id_eq 4573 for more. */ 4574 if (!frame_id_eq (get_stack_frame_id (frame), 4575 ecs->event_thread->control.step_stack_frame_id) 4576 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()), 4577 ecs->event_thread->control.step_stack_frame_id) 4578 && (!frame_id_eq (ecs->event_thread->control.step_stack_frame_id, 4579 outer_frame_id) 4580 || step_start_function != find_pc_function (stop_pc)))) 4581 { 4582 CORE_ADDR real_stop_pc; 4583 4584 if (debug_infrun) 4585 fprintf_unfiltered (gdb_stdlog, "infrun: stepped into subroutine\n"); 4586 4587 if ((ecs->event_thread->control.step_over_calls == STEP_OVER_NONE) 4588 || ((ecs->event_thread->control.step_range_end == 1) 4589 && in_prologue (gdbarch, ecs->event_thread->prev_pc, 4590 ecs->stop_func_start))) 4591 { 4592 /* I presume that step_over_calls is only 0 when we're 4593 supposed to be stepping at the assembly language level 4594 ("stepi"). Just stop. */ 4595 /* Also, maybe we just did a "nexti" inside a prolog, so we 4596 thought it was a subroutine call but it was not. Stop as 4597 well. FENN */ 4598 /* And this works the same backward as frontward. MVS */ 4599 ecs->event_thread->control.stop_step = 1; 4600 print_end_stepping_range_reason (); 4601 stop_stepping (ecs); 4602 return; 4603 } 4604 4605 /* Reverse stepping through solib trampolines. */ 4606 4607 if (execution_direction == EXEC_REVERSE 4608 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE 4609 && (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc) 4610 || (ecs->stop_func_start == 0 4611 && in_solib_dynsym_resolve_code (stop_pc)))) 4612 { 4613 /* Any solib trampoline code can be handled in reverse 4614 by simply continuing to single-step. We have already 4615 executed the solib function (backwards), and a few 4616 steps will take us back through the trampoline to the 4617 caller. */ 4618 keep_going (ecs); 4619 return; 4620 } 4621 4622 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL) 4623 { 4624 /* We're doing a "next". 4625 4626 Normal (forward) execution: set a breakpoint at the 4627 callee's return address (the address at which the caller 4628 will resume). 4629 4630 Reverse (backward) execution. set the step-resume 4631 breakpoint at the start of the function that we just 4632 stepped into (backwards), and continue to there. When we 4633 get there, we'll need to single-step back to the caller. */ 4634 4635 if (execution_direction == EXEC_REVERSE) 4636 { 4637 struct symtab_and_line sr_sal; 4638 4639 /* Normal function call return (static or dynamic). */ 4640 init_sal (&sr_sal); 4641 sr_sal.pc = ecs->stop_func_start; 4642 sr_sal.pspace = get_frame_program_space (frame); 4643 insert_step_resume_breakpoint_at_sal (gdbarch, 4644 sr_sal, null_frame_id); 4645 } 4646 else 4647 insert_step_resume_breakpoint_at_caller (frame); 4648 4649 keep_going (ecs); 4650 return; 4651 } 4652 4653 /* If we are in a function call trampoline (a stub between the 4654 calling routine and the real function), locate the real 4655 function. That's what tells us (a) whether we want to step 4656 into it at all, and (b) what prologue we want to run to the 4657 end of, if we do step into it. */ 4658 real_stop_pc = skip_language_trampoline (frame, stop_pc); 4659 if (real_stop_pc == 0) 4660 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc); 4661 if (real_stop_pc != 0) 4662 ecs->stop_func_start = real_stop_pc; 4663 4664 if (real_stop_pc != 0 && in_solib_dynsym_resolve_code (real_stop_pc)) 4665 { 4666 struct symtab_and_line sr_sal; 4667 4668 init_sal (&sr_sal); 4669 sr_sal.pc = ecs->stop_func_start; 4670 sr_sal.pspace = get_frame_program_space (frame); 4671 4672 insert_step_resume_breakpoint_at_sal (gdbarch, 4673 sr_sal, null_frame_id); 4674 keep_going (ecs); 4675 return; 4676 } 4677 4678 /* If we have line number information for the function we are 4679 thinking of stepping into, step into it. 4680 4681 If there are several symtabs at that PC (e.g. with include 4682 files), just want to know whether *any* of them have line 4683 numbers. find_pc_line handles this. */ 4684 { 4685 struct symtab_and_line tmp_sal; 4686 4687 tmp_sal = find_pc_line (ecs->stop_func_start, 0); 4688 if (tmp_sal.line != 0) 4689 { 4690 if (execution_direction == EXEC_REVERSE) 4691 handle_step_into_function_backward (gdbarch, ecs); 4692 else 4693 handle_step_into_function (gdbarch, ecs); 4694 return; 4695 } 4696 } 4697 4698 /* If we have no line number and the step-stop-if-no-debug is 4699 set, we stop the step so that the user has a chance to switch 4700 in assembly mode. */ 4701 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE 4702 && step_stop_if_no_debug) 4703 { 4704 ecs->event_thread->control.stop_step = 1; 4705 print_end_stepping_range_reason (); 4706 stop_stepping (ecs); 4707 return; 4708 } 4709 4710 if (execution_direction == EXEC_REVERSE) 4711 { 4712 /* Set a breakpoint at callee's start address. 4713 From there we can step once and be back in the caller. */ 4714 struct symtab_and_line sr_sal; 4715 4716 init_sal (&sr_sal); 4717 sr_sal.pc = ecs->stop_func_start; 4718 sr_sal.pspace = get_frame_program_space (frame); 4719 insert_step_resume_breakpoint_at_sal (gdbarch, 4720 sr_sal, null_frame_id); 4721 } 4722 else 4723 /* Set a breakpoint at callee's return address (the address 4724 at which the caller will resume). */ 4725 insert_step_resume_breakpoint_at_caller (frame); 4726 4727 keep_going (ecs); 4728 return; 4729 } 4730 4731 /* Reverse stepping through solib trampolines. */ 4732 4733 if (execution_direction == EXEC_REVERSE 4734 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE) 4735 { 4736 if (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc) 4737 || (ecs->stop_func_start == 0 4738 && in_solib_dynsym_resolve_code (stop_pc))) 4739 { 4740 /* Any solib trampoline code can be handled in reverse 4741 by simply continuing to single-step. We have already 4742 executed the solib function (backwards), and a few 4743 steps will take us back through the trampoline to the 4744 caller. */ 4745 keep_going (ecs); 4746 return; 4747 } 4748 else if (in_solib_dynsym_resolve_code (stop_pc)) 4749 { 4750 /* Stepped backward into the solib dynsym resolver. 4751 Set a breakpoint at its start and continue, then 4752 one more step will take us out. */ 4753 struct symtab_and_line sr_sal; 4754 4755 init_sal (&sr_sal); 4756 sr_sal.pc = ecs->stop_func_start; 4757 sr_sal.pspace = get_frame_program_space (frame); 4758 insert_step_resume_breakpoint_at_sal (gdbarch, 4759 sr_sal, null_frame_id); 4760 keep_going (ecs); 4761 return; 4762 } 4763 } 4764 4765 /* If we're in the return path from a shared library trampoline, 4766 we want to proceed through the trampoline when stepping. */ 4767 if (gdbarch_in_solib_return_trampoline (gdbarch, 4768 stop_pc, ecs->stop_func_name)) 4769 { 4770 /* Determine where this trampoline returns. */ 4771 CORE_ADDR real_stop_pc; 4772 4773 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc); 4774 4775 if (debug_infrun) 4776 fprintf_unfiltered (gdb_stdlog, 4777 "infrun: stepped into solib return tramp\n"); 4778 4779 /* Only proceed through if we know where it's going. */ 4780 if (real_stop_pc) 4781 { 4782 /* And put the step-breakpoint there and go until there. */ 4783 struct symtab_and_line sr_sal; 4784 4785 init_sal (&sr_sal); /* initialize to zeroes */ 4786 sr_sal.pc = real_stop_pc; 4787 sr_sal.section = find_pc_overlay (sr_sal.pc); 4788 sr_sal.pspace = get_frame_program_space (frame); 4789 4790 /* Do not specify what the fp should be when we stop since 4791 on some machines the prologue is where the new fp value 4792 is established. */ 4793 insert_step_resume_breakpoint_at_sal (gdbarch, 4794 sr_sal, null_frame_id); 4795 4796 /* Restart without fiddling with the step ranges or 4797 other state. */ 4798 keep_going (ecs); 4799 return; 4800 } 4801 } 4802 4803 stop_pc_sal = find_pc_line (stop_pc, 0); 4804 4805 /* NOTE: tausq/2004-05-24: This if block used to be done before all 4806 the trampoline processing logic, however, there are some trampolines 4807 that have no names, so we should do trampoline handling first. */ 4808 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE 4809 && ecs->stop_func_name == NULL 4810 && stop_pc_sal.line == 0) 4811 { 4812 if (debug_infrun) 4813 fprintf_unfiltered (gdb_stdlog, 4814 "infrun: stepped into undebuggable function\n"); 4815 4816 /* The inferior just stepped into, or returned to, an 4817 undebuggable function (where there is no debugging information 4818 and no line number corresponding to the address where the 4819 inferior stopped). Since we want to skip this kind of code, 4820 we keep going until the inferior returns from this 4821 function - unless the user has asked us not to (via 4822 set step-mode) or we no longer know how to get back 4823 to the call site. */ 4824 if (step_stop_if_no_debug 4825 || !frame_id_p (frame_unwind_caller_id (frame))) 4826 { 4827 /* If we have no line number and the step-stop-if-no-debug 4828 is set, we stop the step so that the user has a chance to 4829 switch in assembly mode. */ 4830 ecs->event_thread->control.stop_step = 1; 4831 print_end_stepping_range_reason (); 4832 stop_stepping (ecs); 4833 return; 4834 } 4835 else 4836 { 4837 /* Set a breakpoint at callee's return address (the address 4838 at which the caller will resume). */ 4839 insert_step_resume_breakpoint_at_caller (frame); 4840 keep_going (ecs); 4841 return; 4842 } 4843 } 4844 4845 if (ecs->event_thread->control.step_range_end == 1) 4846 { 4847 /* It is stepi or nexti. We always want to stop stepping after 4848 one instruction. */ 4849 if (debug_infrun) 4850 fprintf_unfiltered (gdb_stdlog, "infrun: stepi/nexti\n"); 4851 ecs->event_thread->control.stop_step = 1; 4852 print_end_stepping_range_reason (); 4853 stop_stepping (ecs); 4854 return; 4855 } 4856 4857 if (stop_pc_sal.line == 0) 4858 { 4859 /* We have no line number information. That means to stop 4860 stepping (does this always happen right after one instruction, 4861 when we do "s" in a function with no line numbers, 4862 or can this happen as a result of a return or longjmp?). */ 4863 if (debug_infrun) 4864 fprintf_unfiltered (gdb_stdlog, "infrun: no line number info\n"); 4865 ecs->event_thread->control.stop_step = 1; 4866 print_end_stepping_range_reason (); 4867 stop_stepping (ecs); 4868 return; 4869 } 4870 4871 /* Look for "calls" to inlined functions, part one. If the inline 4872 frame machinery detected some skipped call sites, we have entered 4873 a new inline function. */ 4874 4875 if (frame_id_eq (get_frame_id (get_current_frame ()), 4876 ecs->event_thread->control.step_frame_id) 4877 && inline_skipped_frames (ecs->ptid)) 4878 { 4879 struct symtab_and_line call_sal; 4880 4881 if (debug_infrun) 4882 fprintf_unfiltered (gdb_stdlog, 4883 "infrun: stepped into inlined function\n"); 4884 4885 find_frame_sal (get_current_frame (), &call_sal); 4886 4887 if (ecs->event_thread->control.step_over_calls != STEP_OVER_ALL) 4888 { 4889 /* For "step", we're going to stop. But if the call site 4890 for this inlined function is on the same source line as 4891 we were previously stepping, go down into the function 4892 first. Otherwise stop at the call site. */ 4893 4894 if (call_sal.line == ecs->event_thread->current_line 4895 && call_sal.symtab == ecs->event_thread->current_symtab) 4896 step_into_inline_frame (ecs->ptid); 4897 4898 ecs->event_thread->control.stop_step = 1; 4899 print_end_stepping_range_reason (); 4900 stop_stepping (ecs); 4901 return; 4902 } 4903 else 4904 { 4905 /* For "next", we should stop at the call site if it is on a 4906 different source line. Otherwise continue through the 4907 inlined function. */ 4908 if (call_sal.line == ecs->event_thread->current_line 4909 && call_sal.symtab == ecs->event_thread->current_symtab) 4910 keep_going (ecs); 4911 else 4912 { 4913 ecs->event_thread->control.stop_step = 1; 4914 print_end_stepping_range_reason (); 4915 stop_stepping (ecs); 4916 } 4917 return; 4918 } 4919 } 4920 4921 /* Look for "calls" to inlined functions, part two. If we are still 4922 in the same real function we were stepping through, but we have 4923 to go further up to find the exact frame ID, we are stepping 4924 through a more inlined call beyond its call site. */ 4925 4926 if (get_frame_type (get_current_frame ()) == INLINE_FRAME 4927 && !frame_id_eq (get_frame_id (get_current_frame ()), 4928 ecs->event_thread->control.step_frame_id) 4929 && stepped_in_from (get_current_frame (), 4930 ecs->event_thread->control.step_frame_id)) 4931 { 4932 if (debug_infrun) 4933 fprintf_unfiltered (gdb_stdlog, 4934 "infrun: stepping through inlined function\n"); 4935 4936 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL) 4937 keep_going (ecs); 4938 else 4939 { 4940 ecs->event_thread->control.stop_step = 1; 4941 print_end_stepping_range_reason (); 4942 stop_stepping (ecs); 4943 } 4944 return; 4945 } 4946 4947 if ((stop_pc == stop_pc_sal.pc) 4948 && (ecs->event_thread->current_line != stop_pc_sal.line 4949 || ecs->event_thread->current_symtab != stop_pc_sal.symtab)) 4950 { 4951 /* We are at the start of a different line. So stop. Note that 4952 we don't stop if we step into the middle of a different line. 4953 That is said to make things like for (;;) statements work 4954 better. */ 4955 if (debug_infrun) 4956 fprintf_unfiltered (gdb_stdlog, 4957 "infrun: stepped to a different line\n"); 4958 ecs->event_thread->control.stop_step = 1; 4959 print_end_stepping_range_reason (); 4960 stop_stepping (ecs); 4961 return; 4962 } 4963 4964 /* We aren't done stepping. 4965 4966 Optimize by setting the stepping range to the line. 4967 (We might not be in the original line, but if we entered a 4968 new line in mid-statement, we continue stepping. This makes 4969 things like for(;;) statements work better.) */ 4970 4971 ecs->event_thread->control.step_range_start = stop_pc_sal.pc; 4972 ecs->event_thread->control.step_range_end = stop_pc_sal.end; 4973 set_step_info (frame, stop_pc_sal); 4974 4975 if (debug_infrun) 4976 fprintf_unfiltered (gdb_stdlog, "infrun: keep going\n"); 4977 keep_going (ecs); 4978 } 4979 4980 /* Is thread TP in the middle of single-stepping? */ 4981 4982 static int 4983 currently_stepping (struct thread_info *tp) 4984 { 4985 return ((tp->control.step_range_end 4986 && tp->control.step_resume_breakpoint == NULL) 4987 || tp->control.trap_expected 4988 || tp->stepping_through_solib_after_catch 4989 || bpstat_should_step ()); 4990 } 4991 4992 /* Returns true if any thread *but* the one passed in "data" is in the 4993 middle of stepping or of handling a "next". */ 4994 4995 static int 4996 currently_stepping_or_nexting_callback (struct thread_info *tp, void *data) 4997 { 4998 if (tp == data) 4999 return 0; 5000 5001 return (tp->control.step_range_end 5002 || tp->control.trap_expected 5003 || tp->stepping_through_solib_after_catch); 5004 } 5005 5006 /* Inferior has stepped into a subroutine call with source code that 5007 we should not step over. Do step to the first line of code in 5008 it. */ 5009 5010 static void 5011 handle_step_into_function (struct gdbarch *gdbarch, 5012 struct execution_control_state *ecs) 5013 { 5014 struct symtab *s; 5015 struct symtab_and_line stop_func_sal, sr_sal; 5016 5017 s = find_pc_symtab (stop_pc); 5018 if (s && s->language != language_asm) 5019 ecs->stop_func_start = gdbarch_skip_prologue (gdbarch, 5020 ecs->stop_func_start); 5021 5022 stop_func_sal = find_pc_line (ecs->stop_func_start, 0); 5023 /* Use the step_resume_break to step until the end of the prologue, 5024 even if that involves jumps (as it seems to on the vax under 5025 4.2). */ 5026 /* If the prologue ends in the middle of a source line, continue to 5027 the end of that source line (if it is still within the function). 5028 Otherwise, just go to end of prologue. */ 5029 if (stop_func_sal.end 5030 && stop_func_sal.pc != ecs->stop_func_start 5031 && stop_func_sal.end < ecs->stop_func_end) 5032 ecs->stop_func_start = stop_func_sal.end; 5033 5034 /* Architectures which require breakpoint adjustment might not be able 5035 to place a breakpoint at the computed address. If so, the test 5036 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust 5037 ecs->stop_func_start to an address at which a breakpoint may be 5038 legitimately placed. 5039 5040 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not 5041 made, GDB will enter an infinite loop when stepping through 5042 optimized code consisting of VLIW instructions which contain 5043 subinstructions corresponding to different source lines. On 5044 FR-V, it's not permitted to place a breakpoint on any but the 5045 first subinstruction of a VLIW instruction. When a breakpoint is 5046 set, GDB will adjust the breakpoint address to the beginning of 5047 the VLIW instruction. Thus, we need to make the corresponding 5048 adjustment here when computing the stop address. */ 5049 5050 if (gdbarch_adjust_breakpoint_address_p (gdbarch)) 5051 { 5052 ecs->stop_func_start 5053 = gdbarch_adjust_breakpoint_address (gdbarch, 5054 ecs->stop_func_start); 5055 } 5056 5057 if (ecs->stop_func_start == stop_pc) 5058 { 5059 /* We are already there: stop now. */ 5060 ecs->event_thread->control.stop_step = 1; 5061 print_end_stepping_range_reason (); 5062 stop_stepping (ecs); 5063 return; 5064 } 5065 else 5066 { 5067 /* Put the step-breakpoint there and go until there. */ 5068 init_sal (&sr_sal); /* initialize to zeroes */ 5069 sr_sal.pc = ecs->stop_func_start; 5070 sr_sal.section = find_pc_overlay (ecs->stop_func_start); 5071 sr_sal.pspace = get_frame_program_space (get_current_frame ()); 5072 5073 /* Do not specify what the fp should be when we stop since on 5074 some machines the prologue is where the new fp value is 5075 established. */ 5076 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal, null_frame_id); 5077 5078 /* And make sure stepping stops right away then. */ 5079 ecs->event_thread->control.step_range_end 5080 = ecs->event_thread->control.step_range_start; 5081 } 5082 keep_going (ecs); 5083 } 5084 5085 /* Inferior has stepped backward into a subroutine call with source 5086 code that we should not step over. Do step to the beginning of the 5087 last line of code in it. */ 5088 5089 static void 5090 handle_step_into_function_backward (struct gdbarch *gdbarch, 5091 struct execution_control_state *ecs) 5092 { 5093 struct symtab *s; 5094 struct symtab_and_line stop_func_sal; 5095 5096 s = find_pc_symtab (stop_pc); 5097 if (s && s->language != language_asm) 5098 ecs->stop_func_start = gdbarch_skip_prologue (gdbarch, 5099 ecs->stop_func_start); 5100 5101 stop_func_sal = find_pc_line (stop_pc, 0); 5102 5103 /* OK, we're just going to keep stepping here. */ 5104 if (stop_func_sal.pc == stop_pc) 5105 { 5106 /* We're there already. Just stop stepping now. */ 5107 ecs->event_thread->control.stop_step = 1; 5108 print_end_stepping_range_reason (); 5109 stop_stepping (ecs); 5110 } 5111 else 5112 { 5113 /* Else just reset the step range and keep going. 5114 No step-resume breakpoint, they don't work for 5115 epilogues, which can have multiple entry paths. */ 5116 ecs->event_thread->control.step_range_start = stop_func_sal.pc; 5117 ecs->event_thread->control.step_range_end = stop_func_sal.end; 5118 keep_going (ecs); 5119 } 5120 return; 5121 } 5122 5123 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID. 5124 This is used to both functions and to skip over code. */ 5125 5126 static void 5127 insert_step_resume_breakpoint_at_sal (struct gdbarch *gdbarch, 5128 struct symtab_and_line sr_sal, 5129 struct frame_id sr_id) 5130 { 5131 /* There should never be more than one step-resume or longjmp-resume 5132 breakpoint per thread, so we should never be setting a new 5133 step_resume_breakpoint when one is already active. */ 5134 gdb_assert (inferior_thread ()->control.step_resume_breakpoint == NULL); 5135 5136 if (debug_infrun) 5137 fprintf_unfiltered (gdb_stdlog, 5138 "infrun: inserting step-resume breakpoint at %s\n", 5139 paddress (gdbarch, sr_sal.pc)); 5140 5141 inferior_thread ()->control.step_resume_breakpoint 5142 = set_momentary_breakpoint (gdbarch, sr_sal, sr_id, bp_step_resume); 5143 } 5144 5145 /* Insert a "step-resume breakpoint" at RETURN_FRAME.pc. This is used 5146 to skip a potential signal handler. 5147 5148 This is called with the interrupted function's frame. The signal 5149 handler, when it returns, will resume the interrupted function at 5150 RETURN_FRAME.pc. */ 5151 5152 static void 5153 insert_step_resume_breakpoint_at_frame (struct frame_info *return_frame) 5154 { 5155 struct symtab_and_line sr_sal; 5156 struct gdbarch *gdbarch; 5157 5158 gdb_assert (return_frame != NULL); 5159 init_sal (&sr_sal); /* initialize to zeros */ 5160 5161 gdbarch = get_frame_arch (return_frame); 5162 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch, get_frame_pc (return_frame)); 5163 sr_sal.section = find_pc_overlay (sr_sal.pc); 5164 sr_sal.pspace = get_frame_program_space (return_frame); 5165 5166 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal, 5167 get_stack_frame_id (return_frame)); 5168 } 5169 5170 /* Similar to insert_step_resume_breakpoint_at_frame, except 5171 but a breakpoint at the previous frame's PC. This is used to 5172 skip a function after stepping into it (for "next" or if the called 5173 function has no debugging information). 5174 5175 The current function has almost always been reached by single 5176 stepping a call or return instruction. NEXT_FRAME belongs to the 5177 current function, and the breakpoint will be set at the caller's 5178 resume address. 5179 5180 This is a separate function rather than reusing 5181 insert_step_resume_breakpoint_at_frame in order to avoid 5182 get_prev_frame, which may stop prematurely (see the implementation 5183 of frame_unwind_caller_id for an example). */ 5184 5185 static void 5186 insert_step_resume_breakpoint_at_caller (struct frame_info *next_frame) 5187 { 5188 struct symtab_and_line sr_sal; 5189 struct gdbarch *gdbarch; 5190 5191 /* We shouldn't have gotten here if we don't know where the call site 5192 is. */ 5193 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame))); 5194 5195 init_sal (&sr_sal); /* initialize to zeros */ 5196 5197 gdbarch = frame_unwind_caller_arch (next_frame); 5198 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch, 5199 frame_unwind_caller_pc (next_frame)); 5200 sr_sal.section = find_pc_overlay (sr_sal.pc); 5201 sr_sal.pspace = frame_unwind_program_space (next_frame); 5202 5203 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal, 5204 frame_unwind_caller_id (next_frame)); 5205 } 5206 5207 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a 5208 new breakpoint at the target of a jmp_buf. The handling of 5209 longjmp-resume uses the same mechanisms used for handling 5210 "step-resume" breakpoints. */ 5211 5212 static void 5213 insert_longjmp_resume_breakpoint (struct gdbarch *gdbarch, CORE_ADDR pc) 5214 { 5215 /* There should never be more than one step-resume or longjmp-resume 5216 breakpoint per thread, so we should never be setting a new 5217 longjmp_resume_breakpoint when one is already active. */ 5218 gdb_assert (inferior_thread ()->control.step_resume_breakpoint == NULL); 5219 5220 if (debug_infrun) 5221 fprintf_unfiltered (gdb_stdlog, 5222 "infrun: inserting longjmp-resume breakpoint at %s\n", 5223 paddress (gdbarch, pc)); 5224 5225 inferior_thread ()->control.step_resume_breakpoint = 5226 set_momentary_breakpoint_at_pc (gdbarch, pc, bp_longjmp_resume); 5227 } 5228 5229 /* Insert an exception resume breakpoint. TP is the thread throwing 5230 the exception. The block B is the block of the unwinder debug hook 5231 function. FRAME is the frame corresponding to the call to this 5232 function. SYM is the symbol of the function argument holding the 5233 target PC of the exception. */ 5234 5235 static void 5236 insert_exception_resume_breakpoint (struct thread_info *tp, 5237 struct block *b, 5238 struct frame_info *frame, 5239 struct symbol *sym) 5240 { 5241 struct gdb_exception e; 5242 5243 /* We want to ignore errors here. */ 5244 TRY_CATCH (e, RETURN_MASK_ERROR) 5245 { 5246 struct symbol *vsym; 5247 struct value *value; 5248 CORE_ADDR handler; 5249 struct breakpoint *bp; 5250 5251 vsym = lookup_symbol (SYMBOL_LINKAGE_NAME (sym), b, VAR_DOMAIN, NULL); 5252 value = read_var_value (vsym, frame); 5253 /* If the value was optimized out, revert to the old behavior. */ 5254 if (! value_optimized_out (value)) 5255 { 5256 handler = value_as_address (value); 5257 5258 if (debug_infrun) 5259 fprintf_unfiltered (gdb_stdlog, 5260 "infrun: exception resume at %lx\n", 5261 (unsigned long) handler); 5262 5263 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame), 5264 handler, bp_exception_resume); 5265 bp->thread = tp->num; 5266 inferior_thread ()->control.exception_resume_breakpoint = bp; 5267 } 5268 } 5269 } 5270 5271 /* This is called when an exception has been intercepted. Check to 5272 see whether the exception's destination is of interest, and if so, 5273 set an exception resume breakpoint there. */ 5274 5275 static void 5276 check_exception_resume (struct execution_control_state *ecs, 5277 struct frame_info *frame, struct symbol *func) 5278 { 5279 struct gdb_exception e; 5280 5281 TRY_CATCH (e, RETURN_MASK_ERROR) 5282 { 5283 struct block *b; 5284 struct dict_iterator iter; 5285 struct symbol *sym; 5286 int argno = 0; 5287 5288 /* The exception breakpoint is a thread-specific breakpoint on 5289 the unwinder's debug hook, declared as: 5290 5291 void _Unwind_DebugHook (void *cfa, void *handler); 5292 5293 The CFA argument indicates the frame to which control is 5294 about to be transferred. HANDLER is the destination PC. 5295 5296 We ignore the CFA and set a temporary breakpoint at HANDLER. 5297 This is not extremely efficient but it avoids issues in gdb 5298 with computing the DWARF CFA, and it also works even in weird 5299 cases such as throwing an exception from inside a signal 5300 handler. */ 5301 5302 b = SYMBOL_BLOCK_VALUE (func); 5303 ALL_BLOCK_SYMBOLS (b, iter, sym) 5304 { 5305 if (!SYMBOL_IS_ARGUMENT (sym)) 5306 continue; 5307 5308 if (argno == 0) 5309 ++argno; 5310 else 5311 { 5312 insert_exception_resume_breakpoint (ecs->event_thread, 5313 b, frame, sym); 5314 break; 5315 } 5316 } 5317 } 5318 } 5319 5320 static void 5321 stop_stepping (struct execution_control_state *ecs) 5322 { 5323 if (debug_infrun) 5324 fprintf_unfiltered (gdb_stdlog, "infrun: stop_stepping\n"); 5325 5326 /* Let callers know we don't want to wait for the inferior anymore. */ 5327 ecs->wait_some_more = 0; 5328 } 5329 5330 /* This function handles various cases where we need to continue 5331 waiting for the inferior. */ 5332 /* (Used to be the keep_going: label in the old wait_for_inferior). */ 5333 5334 static void 5335 keep_going (struct execution_control_state *ecs) 5336 { 5337 /* Make sure normal_stop is called if we get a QUIT handled before 5338 reaching resume. */ 5339 struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0); 5340 5341 /* Save the pc before execution, to compare with pc after stop. */ 5342 ecs->event_thread->prev_pc 5343 = regcache_read_pc (get_thread_regcache (ecs->ptid)); 5344 5345 /* If we did not do break;, it means we should keep running the 5346 inferior and not return to debugger. */ 5347 5348 if (ecs->event_thread->control.trap_expected 5349 && ecs->event_thread->suspend.stop_signal != TARGET_SIGNAL_TRAP) 5350 { 5351 /* We took a signal (which we are supposed to pass through to 5352 the inferior, else we'd not get here) and we haven't yet 5353 gotten our trap. Simply continue. */ 5354 5355 discard_cleanups (old_cleanups); 5356 resume (currently_stepping (ecs->event_thread), 5357 ecs->event_thread->suspend.stop_signal); 5358 } 5359 else 5360 { 5361 /* Either the trap was not expected, but we are continuing 5362 anyway (the user asked that this signal be passed to the 5363 child) 5364 -- or -- 5365 The signal was SIGTRAP, e.g. it was our signal, but we 5366 decided we should resume from it. 5367 5368 We're going to run this baby now! 5369 5370 Note that insert_breakpoints won't try to re-insert 5371 already inserted breakpoints. Therefore, we don't 5372 care if breakpoints were already inserted, or not. */ 5373 5374 if (ecs->event_thread->stepping_over_breakpoint) 5375 { 5376 struct regcache *thread_regcache = get_thread_regcache (ecs->ptid); 5377 5378 if (!use_displaced_stepping (get_regcache_arch (thread_regcache))) 5379 /* Since we can't do a displaced step, we have to remove 5380 the breakpoint while we step it. To keep things 5381 simple, we remove them all. */ 5382 remove_breakpoints (); 5383 } 5384 else 5385 { 5386 struct gdb_exception e; 5387 5388 /* Stop stepping when inserting breakpoints 5389 has failed. */ 5390 TRY_CATCH (e, RETURN_MASK_ERROR) 5391 { 5392 insert_breakpoints (); 5393 } 5394 if (e.reason < 0) 5395 { 5396 exception_print (gdb_stderr, e); 5397 stop_stepping (ecs); 5398 return; 5399 } 5400 } 5401 5402 ecs->event_thread->control.trap_expected 5403 = ecs->event_thread->stepping_over_breakpoint; 5404 5405 /* Do not deliver SIGNAL_TRAP (except when the user explicitly 5406 specifies that such a signal should be delivered to the 5407 target program). 5408 5409 Typically, this would occure when a user is debugging a 5410 target monitor on a simulator: the target monitor sets a 5411 breakpoint; the simulator encounters this break-point and 5412 halts the simulation handing control to GDB; GDB, noteing 5413 that the break-point isn't valid, returns control back to the 5414 simulator; the simulator then delivers the hardware 5415 equivalent of a SIGNAL_TRAP to the program being debugged. */ 5416 5417 if (ecs->event_thread->suspend.stop_signal == TARGET_SIGNAL_TRAP 5418 && !signal_program[ecs->event_thread->suspend.stop_signal]) 5419 ecs->event_thread->suspend.stop_signal = TARGET_SIGNAL_0; 5420 5421 discard_cleanups (old_cleanups); 5422 resume (currently_stepping (ecs->event_thread), 5423 ecs->event_thread->suspend.stop_signal); 5424 } 5425 5426 prepare_to_wait (ecs); 5427 } 5428 5429 /* This function normally comes after a resume, before 5430 handle_inferior_event exits. It takes care of any last bits of 5431 housekeeping, and sets the all-important wait_some_more flag. */ 5432 5433 static void 5434 prepare_to_wait (struct execution_control_state *ecs) 5435 { 5436 if (debug_infrun) 5437 fprintf_unfiltered (gdb_stdlog, "infrun: prepare_to_wait\n"); 5438 5439 /* This is the old end of the while loop. Let everybody know we 5440 want to wait for the inferior some more and get called again 5441 soon. */ 5442 ecs->wait_some_more = 1; 5443 } 5444 5445 /* Several print_*_reason functions to print why the inferior has stopped. 5446 We always print something when the inferior exits, or receives a signal. 5447 The rest of the cases are dealt with later on in normal_stop and 5448 print_it_typical. Ideally there should be a call to one of these 5449 print_*_reason functions functions from handle_inferior_event each time 5450 stop_stepping is called. */ 5451 5452 /* Print why the inferior has stopped. 5453 We are done with a step/next/si/ni command, print why the inferior has 5454 stopped. For now print nothing. Print a message only if not in the middle 5455 of doing a "step n" operation for n > 1. */ 5456 5457 static void 5458 print_end_stepping_range_reason (void) 5459 { 5460 if ((!inferior_thread ()->step_multi 5461 || !inferior_thread ()->control.stop_step) 5462 && ui_out_is_mi_like_p (uiout)) 5463 ui_out_field_string (uiout, "reason", 5464 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE)); 5465 } 5466 5467 /* The inferior was terminated by a signal, print why it stopped. */ 5468 5469 static void 5470 print_signal_exited_reason (enum target_signal siggnal) 5471 { 5472 annotate_signalled (); 5473 if (ui_out_is_mi_like_p (uiout)) 5474 ui_out_field_string 5475 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED)); 5476 ui_out_text (uiout, "\nProgram terminated with signal "); 5477 annotate_signal_name (); 5478 ui_out_field_string (uiout, "signal-name", 5479 target_signal_to_name (siggnal)); 5480 annotate_signal_name_end (); 5481 ui_out_text (uiout, ", "); 5482 annotate_signal_string (); 5483 ui_out_field_string (uiout, "signal-meaning", 5484 target_signal_to_string (siggnal)); 5485 annotate_signal_string_end (); 5486 ui_out_text (uiout, ".\n"); 5487 ui_out_text (uiout, "The program no longer exists.\n"); 5488 } 5489 5490 /* The inferior program is finished, print why it stopped. */ 5491 5492 static void 5493 print_exited_reason (int exitstatus) 5494 { 5495 struct inferior *inf = current_inferior (); 5496 const char *pidstr = target_pid_to_str (pid_to_ptid (inf->pid)); 5497 5498 annotate_exited (exitstatus); 5499 if (exitstatus) 5500 { 5501 if (ui_out_is_mi_like_p (uiout)) 5502 ui_out_field_string (uiout, "reason", 5503 async_reason_lookup (EXEC_ASYNC_EXITED)); 5504 ui_out_text (uiout, "[Inferior "); 5505 ui_out_text (uiout, plongest (inf->num)); 5506 ui_out_text (uiout, " ("); 5507 ui_out_text (uiout, pidstr); 5508 ui_out_text (uiout, ") exited with code "); 5509 ui_out_field_fmt (uiout, "exit-code", "0%o", (unsigned int) exitstatus); 5510 ui_out_text (uiout, "]\n"); 5511 } 5512 else 5513 { 5514 if (ui_out_is_mi_like_p (uiout)) 5515 ui_out_field_string 5516 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY)); 5517 ui_out_text (uiout, "[Inferior "); 5518 ui_out_text (uiout, plongest (inf->num)); 5519 ui_out_text (uiout, " ("); 5520 ui_out_text (uiout, pidstr); 5521 ui_out_text (uiout, ") exited normally]\n"); 5522 } 5523 /* Support the --return-child-result option. */ 5524 return_child_result_value = exitstatus; 5525 } 5526 5527 /* Signal received, print why the inferior has stopped. The signal table 5528 tells us to print about it. */ 5529 5530 static void 5531 print_signal_received_reason (enum target_signal siggnal) 5532 { 5533 annotate_signal (); 5534 5535 if (siggnal == TARGET_SIGNAL_0 && !ui_out_is_mi_like_p (uiout)) 5536 { 5537 struct thread_info *t = inferior_thread (); 5538 5539 ui_out_text (uiout, "\n["); 5540 ui_out_field_string (uiout, "thread-name", 5541 target_pid_to_str (t->ptid)); 5542 ui_out_field_fmt (uiout, "thread-id", "] #%d", t->num); 5543 ui_out_text (uiout, " stopped"); 5544 } 5545 else 5546 { 5547 ui_out_text (uiout, "\nProgram received signal "); 5548 annotate_signal_name (); 5549 if (ui_out_is_mi_like_p (uiout)) 5550 ui_out_field_string 5551 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED)); 5552 ui_out_field_string (uiout, "signal-name", 5553 target_signal_to_name (siggnal)); 5554 annotate_signal_name_end (); 5555 ui_out_text (uiout, ", "); 5556 annotate_signal_string (); 5557 ui_out_field_string (uiout, "signal-meaning", 5558 target_signal_to_string (siggnal)); 5559 annotate_signal_string_end (); 5560 } 5561 ui_out_text (uiout, ".\n"); 5562 } 5563 5564 /* Reverse execution: target ran out of history info, print why the inferior 5565 has stopped. */ 5566 5567 static void 5568 print_no_history_reason (void) 5569 { 5570 ui_out_text (uiout, "\nNo more reverse-execution history.\n"); 5571 } 5572 5573 /* Here to return control to GDB when the inferior stops for real. 5574 Print appropriate messages, remove breakpoints, give terminal our modes. 5575 5576 STOP_PRINT_FRAME nonzero means print the executing frame 5577 (pc, function, args, file, line number and line text). 5578 BREAKPOINTS_FAILED nonzero means stop was due to error 5579 attempting to insert breakpoints. */ 5580 5581 void 5582 normal_stop (void) 5583 { 5584 struct target_waitstatus last; 5585 ptid_t last_ptid; 5586 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL); 5587 5588 get_last_target_status (&last_ptid, &last); 5589 5590 /* If an exception is thrown from this point on, make sure to 5591 propagate GDB's knowledge of the executing state to the 5592 frontend/user running state. A QUIT is an easy exception to see 5593 here, so do this before any filtered output. */ 5594 if (!non_stop) 5595 make_cleanup (finish_thread_state_cleanup, &minus_one_ptid); 5596 else if (last.kind != TARGET_WAITKIND_SIGNALLED 5597 && last.kind != TARGET_WAITKIND_EXITED) 5598 make_cleanup (finish_thread_state_cleanup, &inferior_ptid); 5599 5600 /* In non-stop mode, we don't want GDB to switch threads behind the 5601 user's back, to avoid races where the user is typing a command to 5602 apply to thread x, but GDB switches to thread y before the user 5603 finishes entering the command. */ 5604 5605 /* As with the notification of thread events, we want to delay 5606 notifying the user that we've switched thread context until 5607 the inferior actually stops. 5608 5609 There's no point in saying anything if the inferior has exited. 5610 Note that SIGNALLED here means "exited with a signal", not 5611 "received a signal". */ 5612 if (!non_stop 5613 && !ptid_equal (previous_inferior_ptid, inferior_ptid) 5614 && target_has_execution 5615 && last.kind != TARGET_WAITKIND_SIGNALLED 5616 && last.kind != TARGET_WAITKIND_EXITED) 5617 { 5618 target_terminal_ours_for_output (); 5619 printf_filtered (_("[Switching to %s]\n"), 5620 target_pid_to_str (inferior_ptid)); 5621 annotate_thread_changed (); 5622 previous_inferior_ptid = inferior_ptid; 5623 } 5624 5625 if (!breakpoints_always_inserted_mode () && target_has_execution) 5626 { 5627 if (remove_breakpoints ()) 5628 { 5629 target_terminal_ours_for_output (); 5630 printf_filtered (_("Cannot remove breakpoints because " 5631 "program is no longer writable.\nFurther " 5632 "execution is probably impossible.\n")); 5633 } 5634 } 5635 5636 /* If an auto-display called a function and that got a signal, 5637 delete that auto-display to avoid an infinite recursion. */ 5638 5639 if (stopped_by_random_signal) 5640 disable_current_display (); 5641 5642 /* Don't print a message if in the middle of doing a "step n" 5643 operation for n > 1 */ 5644 if (target_has_execution 5645 && last.kind != TARGET_WAITKIND_SIGNALLED 5646 && last.kind != TARGET_WAITKIND_EXITED 5647 && inferior_thread ()->step_multi 5648 && inferior_thread ()->control.stop_step) 5649 goto done; 5650 5651 target_terminal_ours (); 5652 5653 /* Set the current source location. This will also happen if we 5654 display the frame below, but the current SAL will be incorrect 5655 during a user hook-stop function. */ 5656 if (has_stack_frames () && !stop_stack_dummy) 5657 set_current_sal_from_frame (get_current_frame (), 1); 5658 5659 /* Let the user/frontend see the threads as stopped. */ 5660 do_cleanups (old_chain); 5661 5662 /* Look up the hook_stop and run it (CLI internally handles problem 5663 of stop_command's pre-hook not existing). */ 5664 if (stop_command) 5665 catch_errors (hook_stop_stub, stop_command, 5666 "Error while running hook_stop:\n", RETURN_MASK_ALL); 5667 5668 if (!has_stack_frames ()) 5669 goto done; 5670 5671 if (last.kind == TARGET_WAITKIND_SIGNALLED 5672 || last.kind == TARGET_WAITKIND_EXITED) 5673 goto done; 5674 5675 /* Select innermost stack frame - i.e., current frame is frame 0, 5676 and current location is based on that. 5677 Don't do this on return from a stack dummy routine, 5678 or if the program has exited. */ 5679 5680 if (!stop_stack_dummy) 5681 { 5682 select_frame (get_current_frame ()); 5683 5684 /* Print current location without a level number, if 5685 we have changed functions or hit a breakpoint. 5686 Print source line if we have one. 5687 bpstat_print() contains the logic deciding in detail 5688 what to print, based on the event(s) that just occurred. */ 5689 5690 /* If --batch-silent is enabled then there's no need to print the current 5691 source location, and to try risks causing an error message about 5692 missing source files. */ 5693 if (stop_print_frame && !batch_silent) 5694 { 5695 int bpstat_ret; 5696 int source_flag; 5697 int do_frame_printing = 1; 5698 struct thread_info *tp = inferior_thread (); 5699 5700 bpstat_ret = bpstat_print (tp->control.stop_bpstat); 5701 switch (bpstat_ret) 5702 { 5703 case PRINT_UNKNOWN: 5704 /* If we had hit a shared library event breakpoint, 5705 bpstat_print would print out this message. If we hit 5706 an OS-level shared library event, do the same 5707 thing. */ 5708 if (last.kind == TARGET_WAITKIND_LOADED) 5709 { 5710 printf_filtered (_("Stopped due to shared library event\n")); 5711 source_flag = SRC_LINE; /* something bogus */ 5712 do_frame_printing = 0; 5713 break; 5714 } 5715 5716 /* FIXME: cagney/2002-12-01: Given that a frame ID does 5717 (or should) carry around the function and does (or 5718 should) use that when doing a frame comparison. */ 5719 if (tp->control.stop_step 5720 && frame_id_eq (tp->control.step_frame_id, 5721 get_frame_id (get_current_frame ())) 5722 && step_start_function == find_pc_function (stop_pc)) 5723 source_flag = SRC_LINE; /* Finished step, just 5724 print source line. */ 5725 else 5726 source_flag = SRC_AND_LOC; /* Print location and 5727 source line. */ 5728 break; 5729 case PRINT_SRC_AND_LOC: 5730 source_flag = SRC_AND_LOC; /* Print location and 5731 source line. */ 5732 break; 5733 case PRINT_SRC_ONLY: 5734 source_flag = SRC_LINE; 5735 break; 5736 case PRINT_NOTHING: 5737 source_flag = SRC_LINE; /* something bogus */ 5738 do_frame_printing = 0; 5739 break; 5740 default: 5741 internal_error (__FILE__, __LINE__, _("Unknown value.")); 5742 } 5743 5744 /* The behavior of this routine with respect to the source 5745 flag is: 5746 SRC_LINE: Print only source line 5747 LOCATION: Print only location 5748 SRC_AND_LOC: Print location and source line. */ 5749 if (do_frame_printing) 5750 print_stack_frame (get_selected_frame (NULL), 0, source_flag); 5751 5752 /* Display the auto-display expressions. */ 5753 do_displays (); 5754 } 5755 } 5756 5757 /* Save the function value return registers, if we care. 5758 We might be about to restore their previous contents. */ 5759 if (inferior_thread ()->control.proceed_to_finish) 5760 { 5761 /* This should not be necessary. */ 5762 if (stop_registers) 5763 regcache_xfree (stop_registers); 5764 5765 /* NB: The copy goes through to the target picking up the value of 5766 all the registers. */ 5767 stop_registers = regcache_dup (get_current_regcache ()); 5768 } 5769 5770 if (stop_stack_dummy == STOP_STACK_DUMMY) 5771 { 5772 /* Pop the empty frame that contains the stack dummy. 5773 This also restores inferior state prior to the call 5774 (struct infcall_suspend_state). */ 5775 struct frame_info *frame = get_current_frame (); 5776 5777 gdb_assert (get_frame_type (frame) == DUMMY_FRAME); 5778 frame_pop (frame); 5779 /* frame_pop() calls reinit_frame_cache as the last thing it 5780 does which means there's currently no selected frame. We 5781 don't need to re-establish a selected frame if the dummy call 5782 returns normally, that will be done by 5783 restore_infcall_control_state. However, we do have to handle 5784 the case where the dummy call is returning after being 5785 stopped (e.g. the dummy call previously hit a breakpoint). 5786 We can't know which case we have so just always re-establish 5787 a selected frame here. */ 5788 select_frame (get_current_frame ()); 5789 } 5790 5791 done: 5792 annotate_stopped (); 5793 5794 /* Suppress the stop observer if we're in the middle of: 5795 5796 - a step n (n > 1), as there still more steps to be done. 5797 5798 - a "finish" command, as the observer will be called in 5799 finish_command_continuation, so it can include the inferior 5800 function's return value. 5801 5802 - calling an inferior function, as we pretend we inferior didn't 5803 run at all. The return value of the call is handled by the 5804 expression evaluator, through call_function_by_hand. */ 5805 5806 if (!target_has_execution 5807 || last.kind == TARGET_WAITKIND_SIGNALLED 5808 || last.kind == TARGET_WAITKIND_EXITED 5809 || (!inferior_thread ()->step_multi 5810 && !(inferior_thread ()->control.stop_bpstat 5811 && inferior_thread ()->control.proceed_to_finish) 5812 && !inferior_thread ()->control.in_infcall)) 5813 { 5814 if (!ptid_equal (inferior_ptid, null_ptid)) 5815 observer_notify_normal_stop (inferior_thread ()->control.stop_bpstat, 5816 stop_print_frame); 5817 else 5818 observer_notify_normal_stop (NULL, stop_print_frame); 5819 } 5820 5821 if (target_has_execution) 5822 { 5823 if (last.kind != TARGET_WAITKIND_SIGNALLED 5824 && last.kind != TARGET_WAITKIND_EXITED) 5825 /* Delete the breakpoint we stopped at, if it wants to be deleted. 5826 Delete any breakpoint that is to be deleted at the next stop. */ 5827 breakpoint_auto_delete (inferior_thread ()->control.stop_bpstat); 5828 } 5829 5830 /* Try to get rid of automatically added inferiors that are no 5831 longer needed. Keeping those around slows down things linearly. 5832 Note that this never removes the current inferior. */ 5833 prune_inferiors (); 5834 } 5835 5836 static int 5837 hook_stop_stub (void *cmd) 5838 { 5839 execute_cmd_pre_hook ((struct cmd_list_element *) cmd); 5840 return (0); 5841 } 5842 5843 int 5844 signal_stop_state (int signo) 5845 { 5846 return signal_stop[signo]; 5847 } 5848 5849 int 5850 signal_print_state (int signo) 5851 { 5852 return signal_print[signo]; 5853 } 5854 5855 int 5856 signal_pass_state (int signo) 5857 { 5858 return signal_program[signo]; 5859 } 5860 5861 int 5862 signal_stop_update (int signo, int state) 5863 { 5864 int ret = signal_stop[signo]; 5865 5866 signal_stop[signo] = state; 5867 return ret; 5868 } 5869 5870 int 5871 signal_print_update (int signo, int state) 5872 { 5873 int ret = signal_print[signo]; 5874 5875 signal_print[signo] = state; 5876 return ret; 5877 } 5878 5879 int 5880 signal_pass_update (int signo, int state) 5881 { 5882 int ret = signal_program[signo]; 5883 5884 signal_program[signo] = state; 5885 return ret; 5886 } 5887 5888 static void 5889 sig_print_header (void) 5890 { 5891 printf_filtered (_("Signal Stop\tPrint\tPass " 5892 "to program\tDescription\n")); 5893 } 5894 5895 static void 5896 sig_print_info (enum target_signal oursig) 5897 { 5898 const char *name = target_signal_to_name (oursig); 5899 int name_padding = 13 - strlen (name); 5900 5901 if (name_padding <= 0) 5902 name_padding = 0; 5903 5904 printf_filtered ("%s", name); 5905 printf_filtered ("%*.*s ", name_padding, name_padding, " "); 5906 printf_filtered ("%s\t", signal_stop[oursig] ? "Yes" : "No"); 5907 printf_filtered ("%s\t", signal_print[oursig] ? "Yes" : "No"); 5908 printf_filtered ("%s\t\t", signal_program[oursig] ? "Yes" : "No"); 5909 printf_filtered ("%s\n", target_signal_to_string (oursig)); 5910 } 5911 5912 /* Specify how various signals in the inferior should be handled. */ 5913 5914 static void 5915 handle_command (char *args, int from_tty) 5916 { 5917 char **argv; 5918 int digits, wordlen; 5919 int sigfirst, signum, siglast; 5920 enum target_signal oursig; 5921 int allsigs; 5922 int nsigs; 5923 unsigned char *sigs; 5924 struct cleanup *old_chain; 5925 5926 if (args == NULL) 5927 { 5928 error_no_arg (_("signal to handle")); 5929 } 5930 5931 /* Allocate and zero an array of flags for which signals to handle. */ 5932 5933 nsigs = (int) TARGET_SIGNAL_LAST; 5934 sigs = (unsigned char *) alloca (nsigs); 5935 memset (sigs, 0, nsigs); 5936 5937 /* Break the command line up into args. */ 5938 5939 argv = gdb_buildargv (args); 5940 old_chain = make_cleanup_freeargv (argv); 5941 5942 /* Walk through the args, looking for signal oursigs, signal names, and 5943 actions. Signal numbers and signal names may be interspersed with 5944 actions, with the actions being performed for all signals cumulatively 5945 specified. Signal ranges can be specified as <LOW>-<HIGH>. */ 5946 5947 while (*argv != NULL) 5948 { 5949 wordlen = strlen (*argv); 5950 for (digits = 0; isdigit ((*argv)[digits]); digits++) 5951 {; 5952 } 5953 allsigs = 0; 5954 sigfirst = siglast = -1; 5955 5956 if (wordlen >= 1 && !strncmp (*argv, "all", wordlen)) 5957 { 5958 /* Apply action to all signals except those used by the 5959 debugger. Silently skip those. */ 5960 allsigs = 1; 5961 sigfirst = 0; 5962 siglast = nsigs - 1; 5963 } 5964 else if (wordlen >= 1 && !strncmp (*argv, "stop", wordlen)) 5965 { 5966 SET_SIGS (nsigs, sigs, signal_stop); 5967 SET_SIGS (nsigs, sigs, signal_print); 5968 } 5969 else if (wordlen >= 1 && !strncmp (*argv, "ignore", wordlen)) 5970 { 5971 UNSET_SIGS (nsigs, sigs, signal_program); 5972 } 5973 else if (wordlen >= 2 && !strncmp (*argv, "print", wordlen)) 5974 { 5975 SET_SIGS (nsigs, sigs, signal_print); 5976 } 5977 else if (wordlen >= 2 && !strncmp (*argv, "pass", wordlen)) 5978 { 5979 SET_SIGS (nsigs, sigs, signal_program); 5980 } 5981 else if (wordlen >= 3 && !strncmp (*argv, "nostop", wordlen)) 5982 { 5983 UNSET_SIGS (nsigs, sigs, signal_stop); 5984 } 5985 else if (wordlen >= 3 && !strncmp (*argv, "noignore", wordlen)) 5986 { 5987 SET_SIGS (nsigs, sigs, signal_program); 5988 } 5989 else if (wordlen >= 4 && !strncmp (*argv, "noprint", wordlen)) 5990 { 5991 UNSET_SIGS (nsigs, sigs, signal_print); 5992 UNSET_SIGS (nsigs, sigs, signal_stop); 5993 } 5994 else if (wordlen >= 4 && !strncmp (*argv, "nopass", wordlen)) 5995 { 5996 UNSET_SIGS (nsigs, sigs, signal_program); 5997 } 5998 else if (digits > 0) 5999 { 6000 /* It is numeric. The numeric signal refers to our own 6001 internal signal numbering from target.h, not to host/target 6002 signal number. This is a feature; users really should be 6003 using symbolic names anyway, and the common ones like 6004 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */ 6005 6006 sigfirst = siglast = (int) 6007 target_signal_from_command (atoi (*argv)); 6008 if ((*argv)[digits] == '-') 6009 { 6010 siglast = (int) 6011 target_signal_from_command (atoi ((*argv) + digits + 1)); 6012 } 6013 if (sigfirst > siglast) 6014 { 6015 /* Bet he didn't figure we'd think of this case... */ 6016 signum = sigfirst; 6017 sigfirst = siglast; 6018 siglast = signum; 6019 } 6020 } 6021 else 6022 { 6023 oursig = target_signal_from_name (*argv); 6024 if (oursig != TARGET_SIGNAL_UNKNOWN) 6025 { 6026 sigfirst = siglast = (int) oursig; 6027 } 6028 else 6029 { 6030 /* Not a number and not a recognized flag word => complain. */ 6031 error (_("Unrecognized or ambiguous flag word: \"%s\"."), *argv); 6032 } 6033 } 6034 6035 /* If any signal numbers or symbol names were found, set flags for 6036 which signals to apply actions to. */ 6037 6038 for (signum = sigfirst; signum >= 0 && signum <= siglast; signum++) 6039 { 6040 switch ((enum target_signal) signum) 6041 { 6042 case TARGET_SIGNAL_TRAP: 6043 case TARGET_SIGNAL_INT: 6044 if (!allsigs && !sigs[signum]) 6045 { 6046 if (query (_("%s is used by the debugger.\n\ 6047 Are you sure you want to change it? "), 6048 target_signal_to_name ((enum target_signal) signum))) 6049 { 6050 sigs[signum] = 1; 6051 } 6052 else 6053 { 6054 printf_unfiltered (_("Not confirmed, unchanged.\n")); 6055 gdb_flush (gdb_stdout); 6056 } 6057 } 6058 break; 6059 case TARGET_SIGNAL_0: 6060 case TARGET_SIGNAL_DEFAULT: 6061 case TARGET_SIGNAL_UNKNOWN: 6062 /* Make sure that "all" doesn't print these. */ 6063 break; 6064 default: 6065 sigs[signum] = 1; 6066 break; 6067 } 6068 } 6069 6070 argv++; 6071 } 6072 6073 for (signum = 0; signum < nsigs; signum++) 6074 if (sigs[signum]) 6075 { 6076 target_notice_signals (inferior_ptid); 6077 6078 if (from_tty) 6079 { 6080 /* Show the results. */ 6081 sig_print_header (); 6082 for (; signum < nsigs; signum++) 6083 if (sigs[signum]) 6084 sig_print_info (signum); 6085 } 6086 6087 break; 6088 } 6089 6090 do_cleanups (old_chain); 6091 } 6092 6093 static void 6094 xdb_handle_command (char *args, int from_tty) 6095 { 6096 char **argv; 6097 struct cleanup *old_chain; 6098 6099 if (args == NULL) 6100 error_no_arg (_("xdb command")); 6101 6102 /* Break the command line up into args. */ 6103 6104 argv = gdb_buildargv (args); 6105 old_chain = make_cleanup_freeargv (argv); 6106 if (argv[1] != (char *) NULL) 6107 { 6108 char *argBuf; 6109 int bufLen; 6110 6111 bufLen = strlen (argv[0]) + 20; 6112 argBuf = (char *) xmalloc (bufLen); 6113 if (argBuf) 6114 { 6115 int validFlag = 1; 6116 enum target_signal oursig; 6117 6118 oursig = target_signal_from_name (argv[0]); 6119 memset (argBuf, 0, bufLen); 6120 if (strcmp (argv[1], "Q") == 0) 6121 sprintf (argBuf, "%s %s", argv[0], "noprint"); 6122 else 6123 { 6124 if (strcmp (argv[1], "s") == 0) 6125 { 6126 if (!signal_stop[oursig]) 6127 sprintf (argBuf, "%s %s", argv[0], "stop"); 6128 else 6129 sprintf (argBuf, "%s %s", argv[0], "nostop"); 6130 } 6131 else if (strcmp (argv[1], "i") == 0) 6132 { 6133 if (!signal_program[oursig]) 6134 sprintf (argBuf, "%s %s", argv[0], "pass"); 6135 else 6136 sprintf (argBuf, "%s %s", argv[0], "nopass"); 6137 } 6138 else if (strcmp (argv[1], "r") == 0) 6139 { 6140 if (!signal_print[oursig]) 6141 sprintf (argBuf, "%s %s", argv[0], "print"); 6142 else 6143 sprintf (argBuf, "%s %s", argv[0], "noprint"); 6144 } 6145 else 6146 validFlag = 0; 6147 } 6148 if (validFlag) 6149 handle_command (argBuf, from_tty); 6150 else 6151 printf_filtered (_("Invalid signal handling flag.\n")); 6152 if (argBuf) 6153 xfree (argBuf); 6154 } 6155 } 6156 do_cleanups (old_chain); 6157 } 6158 6159 /* Print current contents of the tables set by the handle command. 6160 It is possible we should just be printing signals actually used 6161 by the current target (but for things to work right when switching 6162 targets, all signals should be in the signal tables). */ 6163 6164 static void 6165 signals_info (char *signum_exp, int from_tty) 6166 { 6167 enum target_signal oursig; 6168 6169 sig_print_header (); 6170 6171 if (signum_exp) 6172 { 6173 /* First see if this is a symbol name. */ 6174 oursig = target_signal_from_name (signum_exp); 6175 if (oursig == TARGET_SIGNAL_UNKNOWN) 6176 { 6177 /* No, try numeric. */ 6178 oursig = 6179 target_signal_from_command (parse_and_eval_long (signum_exp)); 6180 } 6181 sig_print_info (oursig); 6182 return; 6183 } 6184 6185 printf_filtered ("\n"); 6186 /* These ugly casts brought to you by the native VAX compiler. */ 6187 for (oursig = TARGET_SIGNAL_FIRST; 6188 (int) oursig < (int) TARGET_SIGNAL_LAST; 6189 oursig = (enum target_signal) ((int) oursig + 1)) 6190 { 6191 QUIT; 6192 6193 if (oursig != TARGET_SIGNAL_UNKNOWN 6194 && oursig != TARGET_SIGNAL_DEFAULT && oursig != TARGET_SIGNAL_0) 6195 sig_print_info (oursig); 6196 } 6197 6198 printf_filtered (_("\nUse the \"handle\" command " 6199 "to change these tables.\n")); 6200 } 6201 6202 /* The $_siginfo convenience variable is a bit special. We don't know 6203 for sure the type of the value until we actually have a chance to 6204 fetch the data. The type can change depending on gdbarch, so it it 6205 also dependent on which thread you have selected. 6206 6207 1. making $_siginfo be an internalvar that creates a new value on 6208 access. 6209 6210 2. making the value of $_siginfo be an lval_computed value. */ 6211 6212 /* This function implements the lval_computed support for reading a 6213 $_siginfo value. */ 6214 6215 static void 6216 siginfo_value_read (struct value *v) 6217 { 6218 LONGEST transferred; 6219 6220 transferred = 6221 target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO, 6222 NULL, 6223 value_contents_all_raw (v), 6224 value_offset (v), 6225 TYPE_LENGTH (value_type (v))); 6226 6227 if (transferred != TYPE_LENGTH (value_type (v))) 6228 error (_("Unable to read siginfo")); 6229 } 6230 6231 /* This function implements the lval_computed support for writing a 6232 $_siginfo value. */ 6233 6234 static void 6235 siginfo_value_write (struct value *v, struct value *fromval) 6236 { 6237 LONGEST transferred; 6238 6239 transferred = target_write (¤t_target, 6240 TARGET_OBJECT_SIGNAL_INFO, 6241 NULL, 6242 value_contents_all_raw (fromval), 6243 value_offset (v), 6244 TYPE_LENGTH (value_type (fromval))); 6245 6246 if (transferred != TYPE_LENGTH (value_type (fromval))) 6247 error (_("Unable to write siginfo")); 6248 } 6249 6250 static struct lval_funcs siginfo_value_funcs = 6251 { 6252 siginfo_value_read, 6253 siginfo_value_write 6254 }; 6255 6256 /* Return a new value with the correct type for the siginfo object of 6257 the current thread using architecture GDBARCH. Return a void value 6258 if there's no object available. */ 6259 6260 static struct value * 6261 siginfo_make_value (struct gdbarch *gdbarch, struct internalvar *var) 6262 { 6263 if (target_has_stack 6264 && !ptid_equal (inferior_ptid, null_ptid) 6265 && gdbarch_get_siginfo_type_p (gdbarch)) 6266 { 6267 struct type *type = gdbarch_get_siginfo_type (gdbarch); 6268 6269 return allocate_computed_value (type, &siginfo_value_funcs, NULL); 6270 } 6271 6272 return allocate_value (builtin_type (gdbarch)->builtin_void); 6273 } 6274 6275 6276 /* infcall_suspend_state contains state about the program itself like its 6277 registers and any signal it received when it last stopped. 6278 This state must be restored regardless of how the inferior function call 6279 ends (either successfully, or after it hits a breakpoint or signal) 6280 if the program is to properly continue where it left off. */ 6281 6282 struct infcall_suspend_state 6283 { 6284 struct thread_suspend_state thread_suspend; 6285 struct inferior_suspend_state inferior_suspend; 6286 6287 /* Other fields: */ 6288 CORE_ADDR stop_pc; 6289 struct regcache *registers; 6290 6291 /* Format of SIGINFO_DATA or NULL if it is not present. */ 6292 struct gdbarch *siginfo_gdbarch; 6293 6294 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of 6295 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the 6296 content would be invalid. */ 6297 gdb_byte *siginfo_data; 6298 }; 6299 6300 struct infcall_suspend_state * 6301 save_infcall_suspend_state (void) 6302 { 6303 struct infcall_suspend_state *inf_state; 6304 struct thread_info *tp = inferior_thread (); 6305 struct inferior *inf = current_inferior (); 6306 struct regcache *regcache = get_current_regcache (); 6307 struct gdbarch *gdbarch = get_regcache_arch (regcache); 6308 gdb_byte *siginfo_data = NULL; 6309 6310 if (gdbarch_get_siginfo_type_p (gdbarch)) 6311 { 6312 struct type *type = gdbarch_get_siginfo_type (gdbarch); 6313 size_t len = TYPE_LENGTH (type); 6314 struct cleanup *back_to; 6315 6316 siginfo_data = xmalloc (len); 6317 back_to = make_cleanup (xfree, siginfo_data); 6318 6319 if (target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL, 6320 siginfo_data, 0, len) == len) 6321 discard_cleanups (back_to); 6322 else 6323 { 6324 /* Errors ignored. */ 6325 do_cleanups (back_to); 6326 siginfo_data = NULL; 6327 } 6328 } 6329 6330 inf_state = XZALLOC (struct infcall_suspend_state); 6331 6332 if (siginfo_data) 6333 { 6334 inf_state->siginfo_gdbarch = gdbarch; 6335 inf_state->siginfo_data = siginfo_data; 6336 } 6337 6338 inf_state->thread_suspend = tp->suspend; 6339 inf_state->inferior_suspend = inf->suspend; 6340 6341 /* run_inferior_call will not use the signal due to its `proceed' call with 6342 TARGET_SIGNAL_0 anyway. */ 6343 tp->suspend.stop_signal = TARGET_SIGNAL_0; 6344 6345 inf_state->stop_pc = stop_pc; 6346 6347 inf_state->registers = regcache_dup (regcache); 6348 6349 return inf_state; 6350 } 6351 6352 /* Restore inferior session state to INF_STATE. */ 6353 6354 void 6355 restore_infcall_suspend_state (struct infcall_suspend_state *inf_state) 6356 { 6357 struct thread_info *tp = inferior_thread (); 6358 struct inferior *inf = current_inferior (); 6359 struct regcache *regcache = get_current_regcache (); 6360 struct gdbarch *gdbarch = get_regcache_arch (regcache); 6361 6362 tp->suspend = inf_state->thread_suspend; 6363 inf->suspend = inf_state->inferior_suspend; 6364 6365 stop_pc = inf_state->stop_pc; 6366 6367 if (inf_state->siginfo_gdbarch == gdbarch) 6368 { 6369 struct type *type = gdbarch_get_siginfo_type (gdbarch); 6370 size_t len = TYPE_LENGTH (type); 6371 6372 /* Errors ignored. */ 6373 target_write (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL, 6374 inf_state->siginfo_data, 0, len); 6375 } 6376 6377 /* The inferior can be gone if the user types "print exit(0)" 6378 (and perhaps other times). */ 6379 if (target_has_execution) 6380 /* NB: The register write goes through to the target. */ 6381 regcache_cpy (regcache, inf_state->registers); 6382 6383 discard_infcall_suspend_state (inf_state); 6384 } 6385 6386 static void 6387 do_restore_infcall_suspend_state_cleanup (void *state) 6388 { 6389 restore_infcall_suspend_state (state); 6390 } 6391 6392 struct cleanup * 6393 make_cleanup_restore_infcall_suspend_state 6394 (struct infcall_suspend_state *inf_state) 6395 { 6396 return make_cleanup (do_restore_infcall_suspend_state_cleanup, inf_state); 6397 } 6398 6399 void 6400 discard_infcall_suspend_state (struct infcall_suspend_state *inf_state) 6401 { 6402 regcache_xfree (inf_state->registers); 6403 xfree (inf_state->siginfo_data); 6404 xfree (inf_state); 6405 } 6406 6407 struct regcache * 6408 get_infcall_suspend_state_regcache (struct infcall_suspend_state *inf_state) 6409 { 6410 return inf_state->registers; 6411 } 6412 6413 /* infcall_control_state contains state regarding gdb's control of the 6414 inferior itself like stepping control. It also contains session state like 6415 the user's currently selected frame. */ 6416 6417 struct infcall_control_state 6418 { 6419 struct thread_control_state thread_control; 6420 struct inferior_control_state inferior_control; 6421 6422 /* Other fields: */ 6423 enum stop_stack_kind stop_stack_dummy; 6424 int stopped_by_random_signal; 6425 int stop_after_trap; 6426 6427 /* ID if the selected frame when the inferior function call was made. */ 6428 struct frame_id selected_frame_id; 6429 }; 6430 6431 /* Save all of the information associated with the inferior<==>gdb 6432 connection. */ 6433 6434 struct infcall_control_state * 6435 save_infcall_control_state (void) 6436 { 6437 struct infcall_control_state *inf_status = xmalloc (sizeof (*inf_status)); 6438 struct thread_info *tp = inferior_thread (); 6439 struct inferior *inf = current_inferior (); 6440 6441 inf_status->thread_control = tp->control; 6442 inf_status->inferior_control = inf->control; 6443 6444 tp->control.step_resume_breakpoint = NULL; 6445 tp->control.exception_resume_breakpoint = NULL; 6446 6447 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of 6448 chain. If caller's caller is walking the chain, they'll be happier if we 6449 hand them back the original chain when restore_infcall_control_state is 6450 called. */ 6451 tp->control.stop_bpstat = bpstat_copy (tp->control.stop_bpstat); 6452 6453 /* Other fields: */ 6454 inf_status->stop_stack_dummy = stop_stack_dummy; 6455 inf_status->stopped_by_random_signal = stopped_by_random_signal; 6456 inf_status->stop_after_trap = stop_after_trap; 6457 6458 inf_status->selected_frame_id = get_frame_id (get_selected_frame (NULL)); 6459 6460 return inf_status; 6461 } 6462 6463 static int 6464 restore_selected_frame (void *args) 6465 { 6466 struct frame_id *fid = (struct frame_id *) args; 6467 struct frame_info *frame; 6468 6469 frame = frame_find_by_id (*fid); 6470 6471 /* If inf_status->selected_frame_id is NULL, there was no previously 6472 selected frame. */ 6473 if (frame == NULL) 6474 { 6475 warning (_("Unable to restore previously selected frame.")); 6476 return 0; 6477 } 6478 6479 select_frame (frame); 6480 6481 return (1); 6482 } 6483 6484 /* Restore inferior session state to INF_STATUS. */ 6485 6486 void 6487 restore_infcall_control_state (struct infcall_control_state *inf_status) 6488 { 6489 struct thread_info *tp = inferior_thread (); 6490 struct inferior *inf = current_inferior (); 6491 6492 if (tp->control.step_resume_breakpoint) 6493 tp->control.step_resume_breakpoint->disposition = disp_del_at_next_stop; 6494 6495 if (tp->control.exception_resume_breakpoint) 6496 tp->control.exception_resume_breakpoint->disposition 6497 = disp_del_at_next_stop; 6498 6499 /* Handle the bpstat_copy of the chain. */ 6500 bpstat_clear (&tp->control.stop_bpstat); 6501 6502 tp->control = inf_status->thread_control; 6503 inf->control = inf_status->inferior_control; 6504 6505 /* Other fields: */ 6506 stop_stack_dummy = inf_status->stop_stack_dummy; 6507 stopped_by_random_signal = inf_status->stopped_by_random_signal; 6508 stop_after_trap = inf_status->stop_after_trap; 6509 6510 if (target_has_stack) 6511 { 6512 /* The point of catch_errors is that if the stack is clobbered, 6513 walking the stack might encounter a garbage pointer and 6514 error() trying to dereference it. */ 6515 if (catch_errors 6516 (restore_selected_frame, &inf_status->selected_frame_id, 6517 "Unable to restore previously selected frame:\n", 6518 RETURN_MASK_ERROR) == 0) 6519 /* Error in restoring the selected frame. Select the innermost 6520 frame. */ 6521 select_frame (get_current_frame ()); 6522 } 6523 6524 xfree (inf_status); 6525 } 6526 6527 static void 6528 do_restore_infcall_control_state_cleanup (void *sts) 6529 { 6530 restore_infcall_control_state (sts); 6531 } 6532 6533 struct cleanup * 6534 make_cleanup_restore_infcall_control_state 6535 (struct infcall_control_state *inf_status) 6536 { 6537 return make_cleanup (do_restore_infcall_control_state_cleanup, inf_status); 6538 } 6539 6540 void 6541 discard_infcall_control_state (struct infcall_control_state *inf_status) 6542 { 6543 if (inf_status->thread_control.step_resume_breakpoint) 6544 inf_status->thread_control.step_resume_breakpoint->disposition 6545 = disp_del_at_next_stop; 6546 6547 if (inf_status->thread_control.exception_resume_breakpoint) 6548 inf_status->thread_control.exception_resume_breakpoint->disposition 6549 = disp_del_at_next_stop; 6550 6551 /* See save_infcall_control_state for info on stop_bpstat. */ 6552 bpstat_clear (&inf_status->thread_control.stop_bpstat); 6553 6554 xfree (inf_status); 6555 } 6556 6557 int 6558 inferior_has_forked (ptid_t pid, ptid_t *child_pid) 6559 { 6560 struct target_waitstatus last; 6561 ptid_t last_ptid; 6562 6563 get_last_target_status (&last_ptid, &last); 6564 6565 if (last.kind != TARGET_WAITKIND_FORKED) 6566 return 0; 6567 6568 if (!ptid_equal (last_ptid, pid)) 6569 return 0; 6570 6571 *child_pid = last.value.related_pid; 6572 return 1; 6573 } 6574 6575 int 6576 inferior_has_vforked (ptid_t pid, ptid_t *child_pid) 6577 { 6578 struct target_waitstatus last; 6579 ptid_t last_ptid; 6580 6581 get_last_target_status (&last_ptid, &last); 6582 6583 if (last.kind != TARGET_WAITKIND_VFORKED) 6584 return 0; 6585 6586 if (!ptid_equal (last_ptid, pid)) 6587 return 0; 6588 6589 *child_pid = last.value.related_pid; 6590 return 1; 6591 } 6592 6593 int 6594 inferior_has_execd (ptid_t pid, char **execd_pathname) 6595 { 6596 struct target_waitstatus last; 6597 ptid_t last_ptid; 6598 6599 get_last_target_status (&last_ptid, &last); 6600 6601 if (last.kind != TARGET_WAITKIND_EXECD) 6602 return 0; 6603 6604 if (!ptid_equal (last_ptid, pid)) 6605 return 0; 6606 6607 *execd_pathname = xstrdup (last.value.execd_pathname); 6608 return 1; 6609 } 6610 6611 int 6612 inferior_has_called_syscall (ptid_t pid, int *syscall_number) 6613 { 6614 struct target_waitstatus last; 6615 ptid_t last_ptid; 6616 6617 get_last_target_status (&last_ptid, &last); 6618 6619 if (last.kind != TARGET_WAITKIND_SYSCALL_ENTRY && 6620 last.kind != TARGET_WAITKIND_SYSCALL_RETURN) 6621 return 0; 6622 6623 if (!ptid_equal (last_ptid, pid)) 6624 return 0; 6625 6626 *syscall_number = last.value.syscall_number; 6627 return 1; 6628 } 6629 6630 /* Oft used ptids */ 6631 ptid_t null_ptid; 6632 ptid_t minus_one_ptid; 6633 6634 /* Create a ptid given the necessary PID, LWP, and TID components. */ 6635 6636 ptid_t 6637 ptid_build (int pid, long lwp, long tid) 6638 { 6639 ptid_t ptid; 6640 6641 ptid.pid = pid; 6642 ptid.lwp = lwp; 6643 ptid.tid = tid; 6644 return ptid; 6645 } 6646 6647 /* Create a ptid from just a pid. */ 6648 6649 ptid_t 6650 pid_to_ptid (int pid) 6651 { 6652 return ptid_build (pid, 0, 0); 6653 } 6654 6655 /* Fetch the pid (process id) component from a ptid. */ 6656 6657 int 6658 ptid_get_pid (ptid_t ptid) 6659 { 6660 return ptid.pid; 6661 } 6662 6663 /* Fetch the lwp (lightweight process) component from a ptid. */ 6664 6665 long 6666 ptid_get_lwp (ptid_t ptid) 6667 { 6668 return ptid.lwp; 6669 } 6670 6671 /* Fetch the tid (thread id) component from a ptid. */ 6672 6673 long 6674 ptid_get_tid (ptid_t ptid) 6675 { 6676 return ptid.tid; 6677 } 6678 6679 /* ptid_equal() is used to test equality of two ptids. */ 6680 6681 int 6682 ptid_equal (ptid_t ptid1, ptid_t ptid2) 6683 { 6684 return (ptid1.pid == ptid2.pid && ptid1.lwp == ptid2.lwp 6685 && ptid1.tid == ptid2.tid); 6686 } 6687 6688 /* Returns true if PTID represents a process. */ 6689 6690 int 6691 ptid_is_pid (ptid_t ptid) 6692 { 6693 if (ptid_equal (minus_one_ptid, ptid)) 6694 return 0; 6695 if (ptid_equal (null_ptid, ptid)) 6696 return 0; 6697 6698 return (ptid_get_lwp (ptid) == 0 && ptid_get_tid (ptid) == 0); 6699 } 6700 6701 int 6702 ptid_match (ptid_t ptid, ptid_t filter) 6703 { 6704 if (ptid_equal (filter, minus_one_ptid)) 6705 return 1; 6706 if (ptid_is_pid (filter) 6707 && ptid_get_pid (ptid) == ptid_get_pid (filter)) 6708 return 1; 6709 else if (ptid_equal (ptid, filter)) 6710 return 1; 6711 6712 return 0; 6713 } 6714 6715 /* restore_inferior_ptid() will be used by the cleanup machinery 6716 to restore the inferior_ptid value saved in a call to 6717 save_inferior_ptid(). */ 6718 6719 static void 6720 restore_inferior_ptid (void *arg) 6721 { 6722 ptid_t *saved_ptid_ptr = arg; 6723 6724 inferior_ptid = *saved_ptid_ptr; 6725 xfree (arg); 6726 } 6727 6728 /* Save the value of inferior_ptid so that it may be restored by a 6729 later call to do_cleanups(). Returns the struct cleanup pointer 6730 needed for later doing the cleanup. */ 6731 6732 struct cleanup * 6733 save_inferior_ptid (void) 6734 { 6735 ptid_t *saved_ptid_ptr; 6736 6737 saved_ptid_ptr = xmalloc (sizeof (ptid_t)); 6738 *saved_ptid_ptr = inferior_ptid; 6739 return make_cleanup (restore_inferior_ptid, saved_ptid_ptr); 6740 } 6741 6742 6743 /* User interface for reverse debugging: 6744 Set exec-direction / show exec-direction commands 6745 (returns error unless target implements to_set_exec_direction method). */ 6746 6747 enum exec_direction_kind execution_direction = EXEC_FORWARD; 6748 static const char exec_forward[] = "forward"; 6749 static const char exec_reverse[] = "reverse"; 6750 static const char *exec_direction = exec_forward; 6751 static const char *exec_direction_names[] = { 6752 exec_forward, 6753 exec_reverse, 6754 NULL 6755 }; 6756 6757 static void 6758 set_exec_direction_func (char *args, int from_tty, 6759 struct cmd_list_element *cmd) 6760 { 6761 if (target_can_execute_reverse) 6762 { 6763 if (!strcmp (exec_direction, exec_forward)) 6764 execution_direction = EXEC_FORWARD; 6765 else if (!strcmp (exec_direction, exec_reverse)) 6766 execution_direction = EXEC_REVERSE; 6767 } 6768 else 6769 { 6770 exec_direction = exec_forward; 6771 error (_("Target does not support this operation.")); 6772 } 6773 } 6774 6775 static void 6776 show_exec_direction_func (struct ui_file *out, int from_tty, 6777 struct cmd_list_element *cmd, const char *value) 6778 { 6779 switch (execution_direction) { 6780 case EXEC_FORWARD: 6781 fprintf_filtered (out, _("Forward.\n")); 6782 break; 6783 case EXEC_REVERSE: 6784 fprintf_filtered (out, _("Reverse.\n")); 6785 break; 6786 case EXEC_ERROR: 6787 default: 6788 fprintf_filtered (out, _("Forward (target `%s' does not " 6789 "support exec-direction).\n"), 6790 target_shortname); 6791 break; 6792 } 6793 } 6794 6795 /* User interface for non-stop mode. */ 6796 6797 int non_stop = 0; 6798 6799 static void 6800 set_non_stop (char *args, int from_tty, 6801 struct cmd_list_element *c) 6802 { 6803 if (target_has_execution) 6804 { 6805 non_stop_1 = non_stop; 6806 error (_("Cannot change this setting while the inferior is running.")); 6807 } 6808 6809 non_stop = non_stop_1; 6810 } 6811 6812 static void 6813 show_non_stop (struct ui_file *file, int from_tty, 6814 struct cmd_list_element *c, const char *value) 6815 { 6816 fprintf_filtered (file, 6817 _("Controlling the inferior in non-stop mode is %s.\n"), 6818 value); 6819 } 6820 6821 static void 6822 show_schedule_multiple (struct ui_file *file, int from_tty, 6823 struct cmd_list_element *c, const char *value) 6824 { 6825 fprintf_filtered (file, _("Resuming the execution of threads " 6826 "of all processes is %s.\n"), value); 6827 } 6828 6829 void 6830 _initialize_infrun (void) 6831 { 6832 int i; 6833 int numsigs; 6834 6835 add_info ("signals", signals_info, _("\ 6836 What debugger does when program gets various signals.\n\ 6837 Specify a signal as argument to print info on that signal only.")); 6838 add_info_alias ("handle", "signals", 0); 6839 6840 add_com ("handle", class_run, handle_command, _("\ 6841 Specify how to handle a signal.\n\ 6842 Args are signals and actions to apply to those signals.\n\ 6843 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\ 6844 from 1-15 are allowed for compatibility with old versions of GDB.\n\ 6845 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\ 6846 The special arg \"all\" is recognized to mean all signals except those\n\ 6847 used by the debugger, typically SIGTRAP and SIGINT.\n\ 6848 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\ 6849 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\ 6850 Stop means reenter debugger if this signal happens (implies print).\n\ 6851 Print means print a message if this signal happens.\n\ 6852 Pass means let program see this signal; otherwise program doesn't know.\n\ 6853 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\ 6854 Pass and Stop may be combined.")); 6855 if (xdb_commands) 6856 { 6857 add_com ("lz", class_info, signals_info, _("\ 6858 What debugger does when program gets various signals.\n\ 6859 Specify a signal as argument to print info on that signal only.")); 6860 add_com ("z", class_run, xdb_handle_command, _("\ 6861 Specify how to handle a signal.\n\ 6862 Args are signals and actions to apply to those signals.\n\ 6863 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\ 6864 from 1-15 are allowed for compatibility with old versions of GDB.\n\ 6865 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\ 6866 The special arg \"all\" is recognized to mean all signals except those\n\ 6867 used by the debugger, typically SIGTRAP and SIGINT.\n\ 6868 Recognized actions include \"s\" (toggles between stop and nostop),\n\ 6869 \"r\" (toggles between print and noprint), \"i\" (toggles between pass and \ 6870 nopass), \"Q\" (noprint)\n\ 6871 Stop means reenter debugger if this signal happens (implies print).\n\ 6872 Print means print a message if this signal happens.\n\ 6873 Pass means let program see this signal; otherwise program doesn't know.\n\ 6874 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\ 6875 Pass and Stop may be combined.")); 6876 } 6877 6878 if (!dbx_commands) 6879 stop_command = add_cmd ("stop", class_obscure, 6880 not_just_help_class_command, _("\ 6881 There is no `stop' command, but you can set a hook on `stop'.\n\ 6882 This allows you to set a list of commands to be run each time execution\n\ 6883 of the program stops."), &cmdlist); 6884 6885 add_setshow_zinteger_cmd ("infrun", class_maintenance, &debug_infrun, _("\ 6886 Set inferior debugging."), _("\ 6887 Show inferior debugging."), _("\ 6888 When non-zero, inferior specific debugging is enabled."), 6889 NULL, 6890 show_debug_infrun, 6891 &setdebuglist, &showdebuglist); 6892 6893 add_setshow_boolean_cmd ("displaced", class_maintenance, 6894 &debug_displaced, _("\ 6895 Set displaced stepping debugging."), _("\ 6896 Show displaced stepping debugging."), _("\ 6897 When non-zero, displaced stepping specific debugging is enabled."), 6898 NULL, 6899 show_debug_displaced, 6900 &setdebuglist, &showdebuglist); 6901 6902 add_setshow_boolean_cmd ("non-stop", no_class, 6903 &non_stop_1, _("\ 6904 Set whether gdb controls the inferior in non-stop mode."), _("\ 6905 Show whether gdb controls the inferior in non-stop mode."), _("\ 6906 When debugging a multi-threaded program and this setting is\n\ 6907 off (the default, also called all-stop mode), when one thread stops\n\ 6908 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\ 6909 all other threads in the program while you interact with the thread of\n\ 6910 interest. When you continue or step a thread, you can allow the other\n\ 6911 threads to run, or have them remain stopped, but while you inspect any\n\ 6912 thread's state, all threads stop.\n\ 6913 \n\ 6914 In non-stop mode, when one thread stops, other threads can continue\n\ 6915 to run freely. You'll be able to step each thread independently,\n\ 6916 leave it stopped or free to run as needed."), 6917 set_non_stop, 6918 show_non_stop, 6919 &setlist, 6920 &showlist); 6921 6922 numsigs = (int) TARGET_SIGNAL_LAST; 6923 signal_stop = (unsigned char *) xmalloc (sizeof (signal_stop[0]) * numsigs); 6924 signal_print = (unsigned char *) 6925 xmalloc (sizeof (signal_print[0]) * numsigs); 6926 signal_program = (unsigned char *) 6927 xmalloc (sizeof (signal_program[0]) * numsigs); 6928 for (i = 0; i < numsigs; i++) 6929 { 6930 signal_stop[i] = 1; 6931 signal_print[i] = 1; 6932 signal_program[i] = 1; 6933 } 6934 6935 /* Signals caused by debugger's own actions 6936 should not be given to the program afterwards. */ 6937 signal_program[TARGET_SIGNAL_TRAP] = 0; 6938 signal_program[TARGET_SIGNAL_INT] = 0; 6939 6940 /* Signals that are not errors should not normally enter the debugger. */ 6941 signal_stop[TARGET_SIGNAL_ALRM] = 0; 6942 signal_print[TARGET_SIGNAL_ALRM] = 0; 6943 signal_stop[TARGET_SIGNAL_VTALRM] = 0; 6944 signal_print[TARGET_SIGNAL_VTALRM] = 0; 6945 signal_stop[TARGET_SIGNAL_PROF] = 0; 6946 signal_print[TARGET_SIGNAL_PROF] = 0; 6947 signal_stop[TARGET_SIGNAL_CHLD] = 0; 6948 signal_print[TARGET_SIGNAL_CHLD] = 0; 6949 signal_stop[TARGET_SIGNAL_IO] = 0; 6950 signal_print[TARGET_SIGNAL_IO] = 0; 6951 signal_stop[TARGET_SIGNAL_POLL] = 0; 6952 signal_print[TARGET_SIGNAL_POLL] = 0; 6953 signal_stop[TARGET_SIGNAL_URG] = 0; 6954 signal_print[TARGET_SIGNAL_URG] = 0; 6955 signal_stop[TARGET_SIGNAL_WINCH] = 0; 6956 signal_print[TARGET_SIGNAL_WINCH] = 0; 6957 signal_stop[TARGET_SIGNAL_PRIO] = 0; 6958 signal_print[TARGET_SIGNAL_PRIO] = 0; 6959 6960 /* These signals are used internally by user-level thread 6961 implementations. (See signal(5) on Solaris.) Like the above 6962 signals, a healthy program receives and handles them as part of 6963 its normal operation. */ 6964 signal_stop[TARGET_SIGNAL_LWP] = 0; 6965 signal_print[TARGET_SIGNAL_LWP] = 0; 6966 signal_stop[TARGET_SIGNAL_WAITING] = 0; 6967 signal_print[TARGET_SIGNAL_WAITING] = 0; 6968 signal_stop[TARGET_SIGNAL_CANCEL] = 0; 6969 signal_print[TARGET_SIGNAL_CANCEL] = 0; 6970 6971 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support, 6972 &stop_on_solib_events, _("\ 6973 Set stopping for shared library events."), _("\ 6974 Show stopping for shared library events."), _("\ 6975 If nonzero, gdb will give control to the user when the dynamic linker\n\ 6976 notifies gdb of shared library events. The most common event of interest\n\ 6977 to the user would be loading/unloading of a new library."), 6978 NULL, 6979 show_stop_on_solib_events, 6980 &setlist, &showlist); 6981 6982 add_setshow_enum_cmd ("follow-fork-mode", class_run, 6983 follow_fork_mode_kind_names, 6984 &follow_fork_mode_string, _("\ 6985 Set debugger response to a program call of fork or vfork."), _("\ 6986 Show debugger response to a program call of fork or vfork."), _("\ 6987 A fork or vfork creates a new process. follow-fork-mode can be:\n\ 6988 parent - the original process is debugged after a fork\n\ 6989 child - the new process is debugged after a fork\n\ 6990 The unfollowed process will continue to run.\n\ 6991 By default, the debugger will follow the parent process."), 6992 NULL, 6993 show_follow_fork_mode_string, 6994 &setlist, &showlist); 6995 6996 add_setshow_enum_cmd ("follow-exec-mode", class_run, 6997 follow_exec_mode_names, 6998 &follow_exec_mode_string, _("\ 6999 Set debugger response to a program call of exec."), _("\ 7000 Show debugger response to a program call of exec."), _("\ 7001 An exec call replaces the program image of a process.\n\ 7002 \n\ 7003 follow-exec-mode can be:\n\ 7004 \n\ 7005 new - the debugger creates a new inferior and rebinds the process\n\ 7006 to this new inferior. The program the process was running before\n\ 7007 the exec call can be restarted afterwards by restarting the original\n\ 7008 inferior.\n\ 7009 \n\ 7010 same - the debugger keeps the process bound to the same inferior.\n\ 7011 The new executable image replaces the previous executable loaded in\n\ 7012 the inferior. Restarting the inferior after the exec call restarts\n\ 7013 the executable the process was running after the exec call.\n\ 7014 \n\ 7015 By default, the debugger will use the same inferior."), 7016 NULL, 7017 show_follow_exec_mode_string, 7018 &setlist, &showlist); 7019 7020 add_setshow_enum_cmd ("scheduler-locking", class_run, 7021 scheduler_enums, &scheduler_mode, _("\ 7022 Set mode for locking scheduler during execution."), _("\ 7023 Show mode for locking scheduler during execution."), _("\ 7024 off == no locking (threads may preempt at any time)\n\ 7025 on == full locking (no thread except the current thread may run)\n\ 7026 step == scheduler locked during every single-step operation.\n\ 7027 In this mode, no other thread may run during a step command.\n\ 7028 Other threads may run while stepping over a function call ('next')."), 7029 set_schedlock_func, /* traps on target vector */ 7030 show_scheduler_mode, 7031 &setlist, &showlist); 7032 7033 add_setshow_boolean_cmd ("schedule-multiple", class_run, &sched_multi, _("\ 7034 Set mode for resuming threads of all processes."), _("\ 7035 Show mode for resuming threads of all processes."), _("\ 7036 When on, execution commands (such as 'continue' or 'next') resume all\n\ 7037 threads of all processes. When off (which is the default), execution\n\ 7038 commands only resume the threads of the current process. The set of\n\ 7039 threads that are resumed is further refined by the scheduler-locking\n\ 7040 mode (see help set scheduler-locking)."), 7041 NULL, 7042 show_schedule_multiple, 7043 &setlist, &showlist); 7044 7045 add_setshow_boolean_cmd ("step-mode", class_run, &step_stop_if_no_debug, _("\ 7046 Set mode of the step operation."), _("\ 7047 Show mode of the step operation."), _("\ 7048 When set, doing a step over a function without debug line information\n\ 7049 will stop at the first instruction of that function. Otherwise, the\n\ 7050 function is skipped and the step command stops at a different source line."), 7051 NULL, 7052 show_step_stop_if_no_debug, 7053 &setlist, &showlist); 7054 7055 add_setshow_enum_cmd ("displaced-stepping", class_run, 7056 can_use_displaced_stepping_enum, 7057 &can_use_displaced_stepping, _("\ 7058 Set debugger's willingness to use displaced stepping."), _("\ 7059 Show debugger's willingness to use displaced stepping."), _("\ 7060 If on, gdb will use displaced stepping to step over breakpoints if it is\n\ 7061 supported by the target architecture. If off, gdb will not use displaced\n\ 7062 stepping to step over breakpoints, even if such is supported by the target\n\ 7063 architecture. If auto (which is the default), gdb will use displaced stepping\n\ 7064 if the target architecture supports it and non-stop mode is active, but will not\n\ 7065 use it in all-stop mode (see help set non-stop)."), 7066 NULL, 7067 show_can_use_displaced_stepping, 7068 &setlist, &showlist); 7069 7070 add_setshow_enum_cmd ("exec-direction", class_run, exec_direction_names, 7071 &exec_direction, _("Set direction of execution.\n\ 7072 Options are 'forward' or 'reverse'."), 7073 _("Show direction of execution (forward/reverse)."), 7074 _("Tells gdb whether to execute forward or backward."), 7075 set_exec_direction_func, show_exec_direction_func, 7076 &setlist, &showlist); 7077 7078 /* Set/show detach-on-fork: user-settable mode. */ 7079 7080 add_setshow_boolean_cmd ("detach-on-fork", class_run, &detach_fork, _("\ 7081 Set whether gdb will detach the child of a fork."), _("\ 7082 Show whether gdb will detach the child of a fork."), _("\ 7083 Tells gdb whether to detach the child of a fork."), 7084 NULL, NULL, &setlist, &showlist); 7085 7086 /* ptid initializations */ 7087 null_ptid = ptid_build (0, 0, 0); 7088 minus_one_ptid = ptid_build (-1, 0, 0); 7089 inferior_ptid = null_ptid; 7090 target_last_wait_ptid = minus_one_ptid; 7091 7092 observer_attach_thread_ptid_changed (infrun_thread_ptid_changed); 7093 observer_attach_thread_stop_requested (infrun_thread_stop_requested); 7094 observer_attach_thread_exit (infrun_thread_thread_exit); 7095 observer_attach_inferior_exit (infrun_inferior_exit); 7096 7097 /* Explicitly create without lookup, since that tries to create a 7098 value with a void typed value, and when we get here, gdbarch 7099 isn't initialized yet. At this point, we're quite sure there 7100 isn't another convenience variable of the same name. */ 7101 create_internalvar_type_lazy ("_siginfo", siginfo_make_value); 7102 7103 add_setshow_boolean_cmd ("observer", no_class, 7104 &observer_mode_1, _("\ 7105 Set whether gdb controls the inferior in observer mode."), _("\ 7106 Show whether gdb controls the inferior in observer mode."), _("\ 7107 In observer mode, GDB can get data from the inferior, but not\n\ 7108 affect its execution. Registers and memory may not be changed,\n\ 7109 breakpoints may not be set, and the program cannot be interrupted\n\ 7110 or signalled."), 7111 set_observer_mode, 7112 show_observer_mode, 7113 &setlist, 7114 &showlist); 7115 } 7116