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 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 "gdb_assert.h" 49 #include "mi/mi-common.h" 50 #include "event-top.h" 51 #include "record.h" 52 #include "inline-frame.h" 53 #include "jit.h" 54 55 /* Prototypes for local functions */ 56 57 static void signals_info (char *, int); 58 59 static void handle_command (char *, int); 60 61 static void sig_print_info (enum target_signal); 62 63 static void sig_print_header (void); 64 65 static void resume_cleanups (void *); 66 67 static int hook_stop_stub (void *); 68 69 static int restore_selected_frame (void *); 70 71 static void build_infrun (void); 72 73 static int follow_fork (void); 74 75 static void set_schedlock_func (char *args, int from_tty, 76 struct cmd_list_element *c); 77 78 static int currently_stepping (struct thread_info *tp); 79 80 static int currently_stepping_or_nexting_callback (struct thread_info *tp, 81 void *data); 82 83 static void xdb_handle_command (char *args, int from_tty); 84 85 static int prepare_to_proceed (int); 86 87 void _initialize_infrun (void); 88 89 void nullify_last_target_wait_ptid (void); 90 91 /* When set, stop the 'step' command if we enter a function which has 92 no line number information. The normal behavior is that we step 93 over such function. */ 94 int step_stop_if_no_debug = 0; 95 static void 96 show_step_stop_if_no_debug (struct ui_file *file, int from_tty, 97 struct cmd_list_element *c, const char *value) 98 { 99 fprintf_filtered (file, _("Mode of the step operation is %s.\n"), value); 100 } 101 102 /* In asynchronous mode, but simulating synchronous execution. */ 103 104 int sync_execution = 0; 105 106 /* wait_for_inferior and normal_stop use this to notify the user 107 when the inferior stopped in a different thread than it had been 108 running in. */ 109 110 static ptid_t previous_inferior_ptid; 111 112 int debug_displaced = 0; 113 static void 114 show_debug_displaced (struct ui_file *file, int from_tty, 115 struct cmd_list_element *c, const char *value) 116 { 117 fprintf_filtered (file, _("Displace stepping debugging is %s.\n"), value); 118 } 119 120 static int debug_infrun = 0; 121 static void 122 show_debug_infrun (struct ui_file *file, int from_tty, 123 struct cmd_list_element *c, const char *value) 124 { 125 fprintf_filtered (file, _("Inferior debugging is %s.\n"), value); 126 } 127 128 /* If the program uses ELF-style shared libraries, then calls to 129 functions in shared libraries go through stubs, which live in a 130 table called the PLT (Procedure Linkage Table). The first time the 131 function is called, the stub sends control to the dynamic linker, 132 which looks up the function's real address, patches the stub so 133 that future calls will go directly to the function, and then passes 134 control to the function. 135 136 If we are stepping at the source level, we don't want to see any of 137 this --- we just want to skip over the stub and the dynamic linker. 138 The simple approach is to single-step until control leaves the 139 dynamic linker. 140 141 However, on some systems (e.g., Red Hat's 5.2 distribution) the 142 dynamic linker calls functions in the shared C library, so you 143 can't tell from the PC alone whether the dynamic linker is still 144 running. In this case, we use a step-resume breakpoint to get us 145 past the dynamic linker, as if we were using "next" to step over a 146 function call. 147 148 in_solib_dynsym_resolve_code() says whether we're in the dynamic 149 linker code or not. Normally, this means we single-step. However, 150 if SKIP_SOLIB_RESOLVER then returns non-zero, then its value is an 151 address where we can place a step-resume breakpoint to get past the 152 linker's symbol resolution function. 153 154 in_solib_dynsym_resolve_code() can generally be implemented in a 155 pretty portable way, by comparing the PC against the address ranges 156 of the dynamic linker's sections. 157 158 SKIP_SOLIB_RESOLVER is generally going to be system-specific, since 159 it depends on internal details of the dynamic linker. It's usually 160 not too hard to figure out where to put a breakpoint, but it 161 certainly isn't portable. SKIP_SOLIB_RESOLVER should do plenty of 162 sanity checking. If it can't figure things out, returning zero and 163 getting the (possibly confusing) stepping behavior is better than 164 signalling an error, which will obscure the change in the 165 inferior's state. */ 166 167 /* This function returns TRUE if pc is the address of an instruction 168 that lies within the dynamic linker (such as the event hook, or the 169 dld itself). 170 171 This function must be used only when a dynamic linker event has 172 been caught, and the inferior is being stepped out of the hook, or 173 undefined results are guaranteed. */ 174 175 #ifndef SOLIB_IN_DYNAMIC_LINKER 176 #define SOLIB_IN_DYNAMIC_LINKER(pid,pc) 0 177 #endif 178 179 180 /* Convert the #defines into values. This is temporary until wfi control 181 flow is completely sorted out. */ 182 183 #ifndef CANNOT_STEP_HW_WATCHPOINTS 184 #define CANNOT_STEP_HW_WATCHPOINTS 0 185 #else 186 #undef CANNOT_STEP_HW_WATCHPOINTS 187 #define CANNOT_STEP_HW_WATCHPOINTS 1 188 #endif 189 190 /* Tables of how to react to signals; the user sets them. */ 191 192 static unsigned char *signal_stop; 193 static unsigned char *signal_print; 194 static unsigned char *signal_program; 195 196 #define SET_SIGS(nsigs,sigs,flags) \ 197 do { \ 198 int signum = (nsigs); \ 199 while (signum-- > 0) \ 200 if ((sigs)[signum]) \ 201 (flags)[signum] = 1; \ 202 } while (0) 203 204 #define UNSET_SIGS(nsigs,sigs,flags) \ 205 do { \ 206 int signum = (nsigs); \ 207 while (signum-- > 0) \ 208 if ((sigs)[signum]) \ 209 (flags)[signum] = 0; \ 210 } while (0) 211 212 /* Value to pass to target_resume() to cause all threads to resume */ 213 214 #define RESUME_ALL minus_one_ptid 215 216 /* Command list pointer for the "stop" placeholder. */ 217 218 static struct cmd_list_element *stop_command; 219 220 /* Function inferior was in as of last step command. */ 221 222 static struct symbol *step_start_function; 223 224 /* Nonzero if we want to give control to the user when we're notified 225 of shared library events by the dynamic linker. */ 226 static int stop_on_solib_events; 227 static void 228 show_stop_on_solib_events (struct ui_file *file, int from_tty, 229 struct cmd_list_element *c, const char *value) 230 { 231 fprintf_filtered (file, _("Stopping for shared library events is %s.\n"), 232 value); 233 } 234 235 /* Nonzero means expecting a trace trap 236 and should stop the inferior and return silently when it happens. */ 237 238 int stop_after_trap; 239 240 /* Save register contents here when executing a "finish" command or are 241 about to pop a stack dummy frame, if-and-only-if proceed_to_finish is set. 242 Thus this contains the return value from the called function (assuming 243 values are returned in a register). */ 244 245 struct regcache *stop_registers; 246 247 /* Nonzero after stop if current stack frame should be printed. */ 248 249 static int stop_print_frame; 250 251 /* This is a cached copy of the pid/waitstatus of the last event 252 returned by target_wait()/deprecated_target_wait_hook(). This 253 information is returned by get_last_target_status(). */ 254 static ptid_t target_last_wait_ptid; 255 static struct target_waitstatus target_last_waitstatus; 256 257 static void context_switch (ptid_t ptid); 258 259 void init_thread_stepping_state (struct thread_info *tss); 260 261 void init_infwait_state (void); 262 263 static const char follow_fork_mode_child[] = "child"; 264 static const char follow_fork_mode_parent[] = "parent"; 265 266 static const char *follow_fork_mode_kind_names[] = { 267 follow_fork_mode_child, 268 follow_fork_mode_parent, 269 NULL 270 }; 271 272 static const char *follow_fork_mode_string = follow_fork_mode_parent; 273 static void 274 show_follow_fork_mode_string (struct ui_file *file, int from_tty, 275 struct cmd_list_element *c, const char *value) 276 { 277 fprintf_filtered (file, _("\ 278 Debugger response to a program call of fork or vfork is \"%s\".\n"), 279 value); 280 } 281 282 283 /* Tell the target to follow the fork we're stopped at. Returns true 284 if the inferior should be resumed; false, if the target for some 285 reason decided it's best not to resume. */ 286 287 static int 288 follow_fork (void) 289 { 290 int follow_child = (follow_fork_mode_string == follow_fork_mode_child); 291 int should_resume = 1; 292 struct thread_info *tp; 293 294 /* Copy user stepping state to the new inferior thread. FIXME: the 295 followed fork child thread should have a copy of most of the 296 parent thread structure's run control related fields, not just these. 297 Initialized to avoid "may be used uninitialized" warnings from gcc. */ 298 struct breakpoint *step_resume_breakpoint = NULL; 299 CORE_ADDR step_range_start = 0; 300 CORE_ADDR step_range_end = 0; 301 struct frame_id step_frame_id = { 0 }; 302 303 if (!non_stop) 304 { 305 ptid_t wait_ptid; 306 struct target_waitstatus wait_status; 307 308 /* Get the last target status returned by target_wait(). */ 309 get_last_target_status (&wait_ptid, &wait_status); 310 311 /* If not stopped at a fork event, then there's nothing else to 312 do. */ 313 if (wait_status.kind != TARGET_WAITKIND_FORKED 314 && wait_status.kind != TARGET_WAITKIND_VFORKED) 315 return 1; 316 317 /* Check if we switched over from WAIT_PTID, since the event was 318 reported. */ 319 if (!ptid_equal (wait_ptid, minus_one_ptid) 320 && !ptid_equal (inferior_ptid, wait_ptid)) 321 { 322 /* We did. Switch back to WAIT_PTID thread, to tell the 323 target to follow it (in either direction). We'll 324 afterwards refuse to resume, and inform the user what 325 happened. */ 326 switch_to_thread (wait_ptid); 327 should_resume = 0; 328 } 329 } 330 331 tp = inferior_thread (); 332 333 /* If there were any forks/vforks that were caught and are now to be 334 followed, then do so now. */ 335 switch (tp->pending_follow.kind) 336 { 337 case TARGET_WAITKIND_FORKED: 338 case TARGET_WAITKIND_VFORKED: 339 { 340 ptid_t parent, child; 341 342 /* If the user did a next/step, etc, over a fork call, 343 preserve the stepping state in the fork child. */ 344 if (follow_child && should_resume) 345 { 346 step_resume_breakpoint 347 = clone_momentary_breakpoint (tp->step_resume_breakpoint); 348 step_range_start = tp->step_range_start; 349 step_range_end = tp->step_range_end; 350 step_frame_id = tp->step_frame_id; 351 352 /* For now, delete the parent's sr breakpoint, otherwise, 353 parent/child sr breakpoints are considered duplicates, 354 and the child version will not be installed. Remove 355 this when the breakpoints module becomes aware of 356 inferiors and address spaces. */ 357 delete_step_resume_breakpoint (tp); 358 tp->step_range_start = 0; 359 tp->step_range_end = 0; 360 tp->step_frame_id = null_frame_id; 361 } 362 363 parent = inferior_ptid; 364 child = tp->pending_follow.value.related_pid; 365 366 /* Tell the target to do whatever is necessary to follow 367 either parent or child. */ 368 if (target_follow_fork (follow_child)) 369 { 370 /* Target refused to follow, or there's some other reason 371 we shouldn't resume. */ 372 should_resume = 0; 373 } 374 else 375 { 376 /* This pending follow fork event is now handled, one way 377 or another. The previous selected thread may be gone 378 from the lists by now, but if it is still around, need 379 to clear the pending follow request. */ 380 tp = find_thread_ptid (parent); 381 if (tp) 382 tp->pending_follow.kind = TARGET_WAITKIND_SPURIOUS; 383 384 /* This makes sure we don't try to apply the "Switched 385 over from WAIT_PID" logic above. */ 386 nullify_last_target_wait_ptid (); 387 388 /* If we followed the child, switch to it... */ 389 if (follow_child) 390 { 391 switch_to_thread (child); 392 393 /* ... and preserve the stepping state, in case the 394 user was stepping over the fork call. */ 395 if (should_resume) 396 { 397 tp = inferior_thread (); 398 tp->step_resume_breakpoint = step_resume_breakpoint; 399 tp->step_range_start = step_range_start; 400 tp->step_range_end = step_range_end; 401 tp->step_frame_id = step_frame_id; 402 } 403 else 404 { 405 /* If we get here, it was because we're trying to 406 resume from a fork catchpoint, but, the user 407 has switched threads away from the thread that 408 forked. In that case, the resume command 409 issued is most likely not applicable to the 410 child, so just warn, and refuse to resume. */ 411 warning (_("\ 412 Not resuming: switched threads before following fork child.\n")); 413 } 414 415 /* Reset breakpoints in the child as appropriate. */ 416 follow_inferior_reset_breakpoints (); 417 } 418 else 419 switch_to_thread (parent); 420 } 421 } 422 break; 423 case TARGET_WAITKIND_SPURIOUS: 424 /* Nothing to follow. */ 425 break; 426 default: 427 internal_error (__FILE__, __LINE__, 428 "Unexpected pending_follow.kind %d\n", 429 tp->pending_follow.kind); 430 break; 431 } 432 433 return should_resume; 434 } 435 436 void 437 follow_inferior_reset_breakpoints (void) 438 { 439 struct thread_info *tp = inferior_thread (); 440 441 /* Was there a step_resume breakpoint? (There was if the user 442 did a "next" at the fork() call.) If so, explicitly reset its 443 thread number. 444 445 step_resumes are a form of bp that are made to be per-thread. 446 Since we created the step_resume bp when the parent process 447 was being debugged, and now are switching to the child process, 448 from the breakpoint package's viewpoint, that's a switch of 449 "threads". We must update the bp's notion of which thread 450 it is for, or it'll be ignored when it triggers. */ 451 452 if (tp->step_resume_breakpoint) 453 breakpoint_re_set_thread (tp->step_resume_breakpoint); 454 455 /* Reinsert all breakpoints in the child. The user may have set 456 breakpoints after catching the fork, in which case those 457 were never set in the child, but only in the parent. This makes 458 sure the inserted breakpoints match the breakpoint list. */ 459 460 breakpoint_re_set (); 461 insert_breakpoints (); 462 } 463 464 /* EXECD_PATHNAME is assumed to be non-NULL. */ 465 466 static void 467 follow_exec (ptid_t pid, char *execd_pathname) 468 { 469 struct target_ops *tgt; 470 struct thread_info *th = inferior_thread (); 471 472 /* This is an exec event that we actually wish to pay attention to. 473 Refresh our symbol table to the newly exec'd program, remove any 474 momentary bp's, etc. 475 476 If there are breakpoints, they aren't really inserted now, 477 since the exec() transformed our inferior into a fresh set 478 of instructions. 479 480 We want to preserve symbolic breakpoints on the list, since 481 we have hopes that they can be reset after the new a.out's 482 symbol table is read. 483 484 However, any "raw" breakpoints must be removed from the list 485 (e.g., the solib bp's), since their address is probably invalid 486 now. 487 488 And, we DON'T want to call delete_breakpoints() here, since 489 that may write the bp's "shadow contents" (the instruction 490 value that was overwritten witha TRAP instruction). Since 491 we now have a new a.out, those shadow contents aren't valid. */ 492 update_breakpoints_after_exec (); 493 494 /* If there was one, it's gone now. We cannot truly step-to-next 495 statement through an exec(). */ 496 th->step_resume_breakpoint = NULL; 497 th->step_range_start = 0; 498 th->step_range_end = 0; 499 500 /* The target reports the exec event to the main thread, even if 501 some other thread does the exec, and even if the main thread was 502 already stopped --- if debugging in non-stop mode, it's possible 503 the user had the main thread held stopped in the previous image 504 --- release it now. This is the same behavior as step-over-exec 505 with scheduler-locking on in all-stop mode. */ 506 th->stop_requested = 0; 507 508 /* What is this a.out's name? */ 509 printf_unfiltered (_("Executing new program: %s\n"), execd_pathname); 510 511 /* We've followed the inferior through an exec. Therefore, the 512 inferior has essentially been killed & reborn. */ 513 514 gdb_flush (gdb_stdout); 515 516 breakpoint_init_inferior (inf_execd); 517 518 if (gdb_sysroot && *gdb_sysroot) 519 { 520 char *name = alloca (strlen (gdb_sysroot) 521 + strlen (execd_pathname) 522 + 1); 523 strcpy (name, gdb_sysroot); 524 strcat (name, execd_pathname); 525 execd_pathname = name; 526 } 527 528 /* That a.out is now the one to use. */ 529 exec_file_attach (execd_pathname, 0); 530 531 /* Reset the shared library package. This ensures that we get a 532 shlib event when the child reaches "_start", at which point the 533 dld will have had a chance to initialize the child. */ 534 /* Also, loading a symbol file below may trigger symbol lookups, and 535 we don't want those to be satisfied by the libraries of the 536 previous incarnation of this process. */ 537 no_shared_libraries (NULL, 0); 538 539 /* Load the main file's symbols. */ 540 symbol_file_add_main (execd_pathname, 0); 541 542 #ifdef SOLIB_CREATE_INFERIOR_HOOK 543 SOLIB_CREATE_INFERIOR_HOOK (PIDGET (inferior_ptid)); 544 #else 545 solib_create_inferior_hook (); 546 #endif 547 548 jit_inferior_created_hook (); 549 550 /* Reinsert all breakpoints. (Those which were symbolic have 551 been reset to the proper address in the new a.out, thanks 552 to symbol_file_command...) */ 553 insert_breakpoints (); 554 555 /* The next resume of this inferior should bring it to the shlib 556 startup breakpoints. (If the user had also set bp's on 557 "main" from the old (parent) process, then they'll auto- 558 matically get reset there in the new process.) */ 559 } 560 561 /* Non-zero if we just simulating a single-step. This is needed 562 because we cannot remove the breakpoints in the inferior process 563 until after the `wait' in `wait_for_inferior'. */ 564 static int singlestep_breakpoints_inserted_p = 0; 565 566 /* The thread we inserted single-step breakpoints for. */ 567 static ptid_t singlestep_ptid; 568 569 /* PC when we started this single-step. */ 570 static CORE_ADDR singlestep_pc; 571 572 /* If another thread hit the singlestep breakpoint, we save the original 573 thread here so that we can resume single-stepping it later. */ 574 static ptid_t saved_singlestep_ptid; 575 static int stepping_past_singlestep_breakpoint; 576 577 /* If not equal to null_ptid, this means that after stepping over breakpoint 578 is finished, we need to switch to deferred_step_ptid, and step it. 579 580 The use case is when one thread has hit a breakpoint, and then the user 581 has switched to another thread and issued 'step'. We need to step over 582 breakpoint in the thread which hit the breakpoint, but then continue 583 stepping the thread user has selected. */ 584 static ptid_t deferred_step_ptid; 585 586 /* Displaced stepping. */ 587 588 /* In non-stop debugging mode, we must take special care to manage 589 breakpoints properly; in particular, the traditional strategy for 590 stepping a thread past a breakpoint it has hit is unsuitable. 591 'Displaced stepping' is a tactic for stepping one thread past a 592 breakpoint it has hit while ensuring that other threads running 593 concurrently will hit the breakpoint as they should. 594 595 The traditional way to step a thread T off a breakpoint in a 596 multi-threaded program in all-stop mode is as follows: 597 598 a0) Initially, all threads are stopped, and breakpoints are not 599 inserted. 600 a1) We single-step T, leaving breakpoints uninserted. 601 a2) We insert breakpoints, and resume all threads. 602 603 In non-stop debugging, however, this strategy is unsuitable: we 604 don't want to have to stop all threads in the system in order to 605 continue or step T past a breakpoint. Instead, we use displaced 606 stepping: 607 608 n0) Initially, T is stopped, other threads are running, and 609 breakpoints are inserted. 610 n1) We copy the instruction "under" the breakpoint to a separate 611 location, outside the main code stream, making any adjustments 612 to the instruction, register, and memory state as directed by 613 T's architecture. 614 n2) We single-step T over the instruction at its new location. 615 n3) We adjust the resulting register and memory state as directed 616 by T's architecture. This includes resetting T's PC to point 617 back into the main instruction stream. 618 n4) We resume T. 619 620 This approach depends on the following gdbarch methods: 621 622 - gdbarch_max_insn_length and gdbarch_displaced_step_location 623 indicate where to copy the instruction, and how much space must 624 be reserved there. We use these in step n1. 625 626 - gdbarch_displaced_step_copy_insn copies a instruction to a new 627 address, and makes any necessary adjustments to the instruction, 628 register contents, and memory. We use this in step n1. 629 630 - gdbarch_displaced_step_fixup adjusts registers and memory after 631 we have successfuly single-stepped the instruction, to yield the 632 same effect the instruction would have had if we had executed it 633 at its original address. We use this in step n3. 634 635 - gdbarch_displaced_step_free_closure provides cleanup. 636 637 The gdbarch_displaced_step_copy_insn and 638 gdbarch_displaced_step_fixup functions must be written so that 639 copying an instruction with gdbarch_displaced_step_copy_insn, 640 single-stepping across the copied instruction, and then applying 641 gdbarch_displaced_insn_fixup should have the same effects on the 642 thread's memory and registers as stepping the instruction in place 643 would have. Exactly which responsibilities fall to the copy and 644 which fall to the fixup is up to the author of those functions. 645 646 See the comments in gdbarch.sh for details. 647 648 Note that displaced stepping and software single-step cannot 649 currently be used in combination, although with some care I think 650 they could be made to. Software single-step works by placing 651 breakpoints on all possible subsequent instructions; if the 652 displaced instruction is a PC-relative jump, those breakpoints 653 could fall in very strange places --- on pages that aren't 654 executable, or at addresses that are not proper instruction 655 boundaries. (We do generally let other threads run while we wait 656 to hit the software single-step breakpoint, and they might 657 encounter such a corrupted instruction.) One way to work around 658 this would be to have gdbarch_displaced_step_copy_insn fully 659 simulate the effect of PC-relative instructions (and return NULL) 660 on architectures that use software single-stepping. 661 662 In non-stop mode, we can have independent and simultaneous step 663 requests, so more than one thread may need to simultaneously step 664 over a breakpoint. The current implementation assumes there is 665 only one scratch space per process. In this case, we have to 666 serialize access to the scratch space. If thread A wants to step 667 over a breakpoint, but we are currently waiting for some other 668 thread to complete a displaced step, we leave thread A stopped and 669 place it in the displaced_step_request_queue. Whenever a displaced 670 step finishes, we pick the next thread in the queue and start a new 671 displaced step operation on it. See displaced_step_prepare and 672 displaced_step_fixup for details. */ 673 674 /* If this is not null_ptid, this is the thread carrying out a 675 displaced single-step. This thread's state will require fixing up 676 once it has completed its step. */ 677 static ptid_t displaced_step_ptid; 678 679 struct displaced_step_request 680 { 681 ptid_t ptid; 682 struct displaced_step_request *next; 683 }; 684 685 /* A queue of pending displaced stepping requests. */ 686 struct displaced_step_request *displaced_step_request_queue; 687 688 /* The architecture the thread had when we stepped it. */ 689 static struct gdbarch *displaced_step_gdbarch; 690 691 /* The closure provided gdbarch_displaced_step_copy_insn, to be used 692 for post-step cleanup. */ 693 static struct displaced_step_closure *displaced_step_closure; 694 695 /* The address of the original instruction, and the copy we made. */ 696 static CORE_ADDR displaced_step_original, displaced_step_copy; 697 698 /* Saved contents of copy area. */ 699 static gdb_byte *displaced_step_saved_copy; 700 701 /* Enum strings for "set|show displaced-stepping". */ 702 703 static const char can_use_displaced_stepping_auto[] = "auto"; 704 static const char can_use_displaced_stepping_on[] = "on"; 705 static const char can_use_displaced_stepping_off[] = "off"; 706 static const char *can_use_displaced_stepping_enum[] = 707 { 708 can_use_displaced_stepping_auto, 709 can_use_displaced_stepping_on, 710 can_use_displaced_stepping_off, 711 NULL, 712 }; 713 714 /* If ON, and the architecture supports it, GDB will use displaced 715 stepping to step over breakpoints. If OFF, or if the architecture 716 doesn't support it, GDB will instead use the traditional 717 hold-and-step approach. If AUTO (which is the default), GDB will 718 decide which technique to use to step over breakpoints depending on 719 which of all-stop or non-stop mode is active --- displaced stepping 720 in non-stop mode; hold-and-step in all-stop mode. */ 721 722 static const char *can_use_displaced_stepping = 723 can_use_displaced_stepping_auto; 724 725 static void 726 show_can_use_displaced_stepping (struct ui_file *file, int from_tty, 727 struct cmd_list_element *c, 728 const char *value) 729 { 730 if (can_use_displaced_stepping == can_use_displaced_stepping_auto) 731 fprintf_filtered (file, _("\ 732 Debugger's willingness to use displaced stepping to step over \ 733 breakpoints is %s (currently %s).\n"), 734 value, non_stop ? "on" : "off"); 735 else 736 fprintf_filtered (file, _("\ 737 Debugger's willingness to use displaced stepping to step over \ 738 breakpoints is %s.\n"), value); 739 } 740 741 /* Return non-zero if displaced stepping can/should be used to step 742 over breakpoints. */ 743 744 static int 745 use_displaced_stepping (struct gdbarch *gdbarch) 746 { 747 return (((can_use_displaced_stepping == can_use_displaced_stepping_auto 748 && non_stop) 749 || can_use_displaced_stepping == can_use_displaced_stepping_on) 750 && gdbarch_displaced_step_copy_insn_p (gdbarch) 751 && !RECORD_IS_USED); 752 } 753 754 /* Clean out any stray displaced stepping state. */ 755 static void 756 displaced_step_clear (void) 757 { 758 /* Indicate that there is no cleanup pending. */ 759 displaced_step_ptid = null_ptid; 760 761 if (displaced_step_closure) 762 { 763 gdbarch_displaced_step_free_closure (displaced_step_gdbarch, 764 displaced_step_closure); 765 displaced_step_closure = NULL; 766 } 767 } 768 769 static void 770 displaced_step_clear_cleanup (void *ignore) 771 { 772 displaced_step_clear (); 773 } 774 775 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */ 776 void 777 displaced_step_dump_bytes (struct ui_file *file, 778 const gdb_byte *buf, 779 size_t len) 780 { 781 int i; 782 783 for (i = 0; i < len; i++) 784 fprintf_unfiltered (file, "%02x ", buf[i]); 785 fputs_unfiltered ("\n", file); 786 } 787 788 /* Prepare to single-step, using displaced stepping. 789 790 Note that we cannot use displaced stepping when we have a signal to 791 deliver. If we have a signal to deliver and an instruction to step 792 over, then after the step, there will be no indication from the 793 target whether the thread entered a signal handler or ignored the 794 signal and stepped over the instruction successfully --- both cases 795 result in a simple SIGTRAP. In the first case we mustn't do a 796 fixup, and in the second case we must --- but we can't tell which. 797 Comments in the code for 'random signals' in handle_inferior_event 798 explain how we handle this case instead. 799 800 Returns 1 if preparing was successful -- this thread is going to be 801 stepped now; or 0 if displaced stepping this thread got queued. */ 802 static int 803 displaced_step_prepare (ptid_t ptid) 804 { 805 struct cleanup *old_cleanups, *ignore_cleanups; 806 struct regcache *regcache = get_thread_regcache (ptid); 807 struct gdbarch *gdbarch = get_regcache_arch (regcache); 808 CORE_ADDR original, copy; 809 ULONGEST len; 810 struct displaced_step_closure *closure; 811 812 /* We should never reach this function if the architecture does not 813 support displaced stepping. */ 814 gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch)); 815 816 /* For the first cut, we're displaced stepping one thread at a 817 time. */ 818 819 if (!ptid_equal (displaced_step_ptid, null_ptid)) 820 { 821 /* Already waiting for a displaced step to finish. Defer this 822 request and place in queue. */ 823 struct displaced_step_request *req, *new_req; 824 825 if (debug_displaced) 826 fprintf_unfiltered (gdb_stdlog, 827 "displaced: defering step of %s\n", 828 target_pid_to_str (ptid)); 829 830 new_req = xmalloc (sizeof (*new_req)); 831 new_req->ptid = ptid; 832 new_req->next = NULL; 833 834 if (displaced_step_request_queue) 835 { 836 for (req = displaced_step_request_queue; 837 req && req->next; 838 req = req->next) 839 ; 840 req->next = new_req; 841 } 842 else 843 displaced_step_request_queue = new_req; 844 845 return 0; 846 } 847 else 848 { 849 if (debug_displaced) 850 fprintf_unfiltered (gdb_stdlog, 851 "displaced: stepping %s now\n", 852 target_pid_to_str (ptid)); 853 } 854 855 displaced_step_clear (); 856 857 old_cleanups = save_inferior_ptid (); 858 inferior_ptid = ptid; 859 860 original = regcache_read_pc (regcache); 861 862 copy = gdbarch_displaced_step_location (gdbarch); 863 len = gdbarch_max_insn_length (gdbarch); 864 865 /* Save the original contents of the copy area. */ 866 displaced_step_saved_copy = xmalloc (len); 867 ignore_cleanups = make_cleanup (free_current_contents, 868 &displaced_step_saved_copy); 869 read_memory (copy, displaced_step_saved_copy, len); 870 if (debug_displaced) 871 { 872 fprintf_unfiltered (gdb_stdlog, "displaced: saved %s: ", 873 paddress (gdbarch, copy)); 874 displaced_step_dump_bytes (gdb_stdlog, displaced_step_saved_copy, len); 875 }; 876 877 closure = gdbarch_displaced_step_copy_insn (gdbarch, 878 original, copy, regcache); 879 880 /* We don't support the fully-simulated case at present. */ 881 gdb_assert (closure); 882 883 /* Save the information we need to fix things up if the step 884 succeeds. */ 885 displaced_step_ptid = ptid; 886 displaced_step_gdbarch = gdbarch; 887 displaced_step_closure = closure; 888 displaced_step_original = original; 889 displaced_step_copy = copy; 890 891 make_cleanup (displaced_step_clear_cleanup, 0); 892 893 /* Resume execution at the copy. */ 894 regcache_write_pc (regcache, copy); 895 896 discard_cleanups (ignore_cleanups); 897 898 do_cleanups (old_cleanups); 899 900 if (debug_displaced) 901 fprintf_unfiltered (gdb_stdlog, "displaced: displaced pc to %s\n", 902 paddress (gdbarch, copy)); 903 904 return 1; 905 } 906 907 static void 908 write_memory_ptid (ptid_t ptid, CORE_ADDR memaddr, const gdb_byte *myaddr, int len) 909 { 910 struct cleanup *ptid_cleanup = save_inferior_ptid (); 911 inferior_ptid = ptid; 912 write_memory (memaddr, myaddr, len); 913 do_cleanups (ptid_cleanup); 914 } 915 916 static void 917 displaced_step_fixup (ptid_t event_ptid, enum target_signal signal) 918 { 919 struct cleanup *old_cleanups; 920 921 /* Was this event for the pid we displaced? */ 922 if (ptid_equal (displaced_step_ptid, null_ptid) 923 || ! ptid_equal (displaced_step_ptid, event_ptid)) 924 return; 925 926 old_cleanups = make_cleanup (displaced_step_clear_cleanup, 0); 927 928 /* Restore the contents of the copy area. */ 929 { 930 ULONGEST len = gdbarch_max_insn_length (displaced_step_gdbarch); 931 write_memory_ptid (displaced_step_ptid, displaced_step_copy, 932 displaced_step_saved_copy, len); 933 if (debug_displaced) 934 fprintf_unfiltered (gdb_stdlog, "displaced: restored %s\n", 935 paddress (displaced_step_gdbarch, 936 displaced_step_copy)); 937 } 938 939 /* Did the instruction complete successfully? */ 940 if (signal == TARGET_SIGNAL_TRAP) 941 { 942 /* Fix up the resulting state. */ 943 gdbarch_displaced_step_fixup (displaced_step_gdbarch, 944 displaced_step_closure, 945 displaced_step_original, 946 displaced_step_copy, 947 get_thread_regcache (displaced_step_ptid)); 948 } 949 else 950 { 951 /* Since the instruction didn't complete, all we can do is 952 relocate the PC. */ 953 struct regcache *regcache = get_thread_regcache (event_ptid); 954 CORE_ADDR pc = regcache_read_pc (regcache); 955 pc = displaced_step_original + (pc - displaced_step_copy); 956 regcache_write_pc (regcache, pc); 957 } 958 959 do_cleanups (old_cleanups); 960 961 displaced_step_ptid = null_ptid; 962 963 /* Are there any pending displaced stepping requests? If so, run 964 one now. */ 965 while (displaced_step_request_queue) 966 { 967 struct displaced_step_request *head; 968 ptid_t ptid; 969 struct regcache *regcache; 970 struct gdbarch *gdbarch; 971 CORE_ADDR actual_pc; 972 973 head = displaced_step_request_queue; 974 ptid = head->ptid; 975 displaced_step_request_queue = head->next; 976 xfree (head); 977 978 context_switch (ptid); 979 980 regcache = get_thread_regcache (ptid); 981 actual_pc = regcache_read_pc (regcache); 982 983 if (breakpoint_here_p (actual_pc)) 984 { 985 if (debug_displaced) 986 fprintf_unfiltered (gdb_stdlog, 987 "displaced: stepping queued %s now\n", 988 target_pid_to_str (ptid)); 989 990 displaced_step_prepare (ptid); 991 992 gdbarch = get_regcache_arch (regcache); 993 994 if (debug_displaced) 995 { 996 CORE_ADDR actual_pc = regcache_read_pc (regcache); 997 gdb_byte buf[4]; 998 999 fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ", 1000 paddress (gdbarch, actual_pc)); 1001 read_memory (actual_pc, buf, sizeof (buf)); 1002 displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf)); 1003 } 1004 1005 if (gdbarch_displaced_step_hw_singlestep 1006 (gdbarch, displaced_step_closure)) 1007 target_resume (ptid, 1, TARGET_SIGNAL_0); 1008 else 1009 target_resume (ptid, 0, TARGET_SIGNAL_0); 1010 1011 /* Done, we're stepping a thread. */ 1012 break; 1013 } 1014 else 1015 { 1016 int step; 1017 struct thread_info *tp = inferior_thread (); 1018 1019 /* The breakpoint we were sitting under has since been 1020 removed. */ 1021 tp->trap_expected = 0; 1022 1023 /* Go back to what we were trying to do. */ 1024 step = currently_stepping (tp); 1025 1026 if (debug_displaced) 1027 fprintf_unfiltered (gdb_stdlog, "breakpoint is gone %s: step(%d)\n", 1028 target_pid_to_str (tp->ptid), step); 1029 1030 target_resume (ptid, step, TARGET_SIGNAL_0); 1031 tp->stop_signal = TARGET_SIGNAL_0; 1032 1033 /* This request was discarded. See if there's any other 1034 thread waiting for its turn. */ 1035 } 1036 } 1037 } 1038 1039 /* Update global variables holding ptids to hold NEW_PTID if they were 1040 holding OLD_PTID. */ 1041 static void 1042 infrun_thread_ptid_changed (ptid_t old_ptid, ptid_t new_ptid) 1043 { 1044 struct displaced_step_request *it; 1045 1046 if (ptid_equal (inferior_ptid, old_ptid)) 1047 inferior_ptid = new_ptid; 1048 1049 if (ptid_equal (singlestep_ptid, old_ptid)) 1050 singlestep_ptid = new_ptid; 1051 1052 if (ptid_equal (displaced_step_ptid, old_ptid)) 1053 displaced_step_ptid = new_ptid; 1054 1055 if (ptid_equal (deferred_step_ptid, old_ptid)) 1056 deferred_step_ptid = new_ptid; 1057 1058 for (it = displaced_step_request_queue; it; it = it->next) 1059 if (ptid_equal (it->ptid, old_ptid)) 1060 it->ptid = new_ptid; 1061 } 1062 1063 1064 /* Resuming. */ 1065 1066 /* Things to clean up if we QUIT out of resume (). */ 1067 static void 1068 resume_cleanups (void *ignore) 1069 { 1070 normal_stop (); 1071 } 1072 1073 static const char schedlock_off[] = "off"; 1074 static const char schedlock_on[] = "on"; 1075 static const char schedlock_step[] = "step"; 1076 static const char *scheduler_enums[] = { 1077 schedlock_off, 1078 schedlock_on, 1079 schedlock_step, 1080 NULL 1081 }; 1082 static const char *scheduler_mode = schedlock_off; 1083 static void 1084 show_scheduler_mode (struct ui_file *file, int from_tty, 1085 struct cmd_list_element *c, const char *value) 1086 { 1087 fprintf_filtered (file, _("\ 1088 Mode for locking scheduler during execution is \"%s\".\n"), 1089 value); 1090 } 1091 1092 static void 1093 set_schedlock_func (char *args, int from_tty, struct cmd_list_element *c) 1094 { 1095 if (!target_can_lock_scheduler) 1096 { 1097 scheduler_mode = schedlock_off; 1098 error (_("Target '%s' cannot support this command."), target_shortname); 1099 } 1100 } 1101 1102 /* True if execution commands resume all threads of all processes by 1103 default; otherwise, resume only threads of the current inferior 1104 process. */ 1105 int sched_multi = 0; 1106 1107 /* Try to setup for software single stepping over the specified location. 1108 Return 1 if target_resume() should use hardware single step. 1109 1110 GDBARCH the current gdbarch. 1111 PC the location to step over. */ 1112 1113 static int 1114 maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc) 1115 { 1116 int hw_step = 1; 1117 1118 if (gdbarch_software_single_step_p (gdbarch) 1119 && gdbarch_software_single_step (gdbarch, get_current_frame ())) 1120 { 1121 hw_step = 0; 1122 /* Do not pull these breakpoints until after a `wait' in 1123 `wait_for_inferior' */ 1124 singlestep_breakpoints_inserted_p = 1; 1125 singlestep_ptid = inferior_ptid; 1126 singlestep_pc = pc; 1127 } 1128 return hw_step; 1129 } 1130 1131 /* Resume the inferior, but allow a QUIT. This is useful if the user 1132 wants to interrupt some lengthy single-stepping operation 1133 (for child processes, the SIGINT goes to the inferior, and so 1134 we get a SIGINT random_signal, but for remote debugging and perhaps 1135 other targets, that's not true). 1136 1137 STEP nonzero if we should step (zero to continue instead). 1138 SIG is the signal to give the inferior (zero for none). */ 1139 void 1140 resume (int step, enum target_signal sig) 1141 { 1142 int should_resume = 1; 1143 struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0); 1144 struct regcache *regcache = get_current_regcache (); 1145 struct gdbarch *gdbarch = get_regcache_arch (regcache); 1146 struct thread_info *tp = inferior_thread (); 1147 CORE_ADDR pc = regcache_read_pc (regcache); 1148 1149 QUIT; 1150 1151 if (debug_infrun) 1152 fprintf_unfiltered (gdb_stdlog, 1153 "infrun: resume (step=%d, signal=%d), " 1154 "trap_expected=%d\n", 1155 step, sig, tp->trap_expected); 1156 1157 /* Some targets (e.g. Solaris x86) have a kernel bug when stepping 1158 over an instruction that causes a page fault without triggering 1159 a hardware watchpoint. The kernel properly notices that it shouldn't 1160 stop, because the hardware watchpoint is not triggered, but it forgets 1161 the step request and continues the program normally. 1162 Work around the problem by removing hardware watchpoints if a step is 1163 requested, GDB will check for a hardware watchpoint trigger after the 1164 step anyway. */ 1165 if (CANNOT_STEP_HW_WATCHPOINTS && step) 1166 remove_hw_watchpoints (); 1167 1168 1169 /* Normally, by the time we reach `resume', the breakpoints are either 1170 removed or inserted, as appropriate. The exception is if we're sitting 1171 at a permanent breakpoint; we need to step over it, but permanent 1172 breakpoints can't be removed. So we have to test for it here. */ 1173 if (breakpoint_here_p (pc) == permanent_breakpoint_here) 1174 { 1175 if (gdbarch_skip_permanent_breakpoint_p (gdbarch)) 1176 gdbarch_skip_permanent_breakpoint (gdbarch, regcache); 1177 else 1178 error (_("\ 1179 The program is stopped at a permanent breakpoint, but GDB does not know\n\ 1180 how to step past a permanent breakpoint on this architecture. Try using\n\ 1181 a command like `return' or `jump' to continue execution.")); 1182 } 1183 1184 /* If enabled, step over breakpoints by executing a copy of the 1185 instruction at a different address. 1186 1187 We can't use displaced stepping when we have a signal to deliver; 1188 the comments for displaced_step_prepare explain why. The 1189 comments in the handle_inferior event for dealing with 'random 1190 signals' explain what we do instead. */ 1191 if (use_displaced_stepping (gdbarch) 1192 && (tp->trap_expected 1193 || (step && gdbarch_software_single_step_p (gdbarch))) 1194 && sig == TARGET_SIGNAL_0) 1195 { 1196 if (!displaced_step_prepare (inferior_ptid)) 1197 { 1198 /* Got placed in displaced stepping queue. Will be resumed 1199 later when all the currently queued displaced stepping 1200 requests finish. The thread is not executing at this point, 1201 and the call to set_executing will be made later. But we 1202 need to call set_running here, since from frontend point of view, 1203 the thread is running. */ 1204 set_running (inferior_ptid, 1); 1205 discard_cleanups (old_cleanups); 1206 return; 1207 } 1208 1209 step = gdbarch_displaced_step_hw_singlestep 1210 (gdbarch, displaced_step_closure); 1211 } 1212 1213 /* Do we need to do it the hard way, w/temp breakpoints? */ 1214 else if (step) 1215 step = maybe_software_singlestep (gdbarch, pc); 1216 1217 if (should_resume) 1218 { 1219 ptid_t resume_ptid; 1220 1221 /* If STEP is set, it's a request to use hardware stepping 1222 facilities. But in that case, we should never 1223 use singlestep breakpoint. */ 1224 gdb_assert (!(singlestep_breakpoints_inserted_p && step)); 1225 1226 /* Decide the set of threads to ask the target to resume. Start 1227 by assuming everything will be resumed, than narrow the set 1228 by applying increasingly restricting conditions. */ 1229 1230 /* By default, resume all threads of all processes. */ 1231 resume_ptid = RESUME_ALL; 1232 1233 /* Maybe resume only all threads of the current process. */ 1234 if (!sched_multi && target_supports_multi_process ()) 1235 { 1236 resume_ptid = pid_to_ptid (ptid_get_pid (inferior_ptid)); 1237 } 1238 1239 /* Maybe resume a single thread after all. */ 1240 if (singlestep_breakpoints_inserted_p 1241 && stepping_past_singlestep_breakpoint) 1242 { 1243 /* The situation here is as follows. In thread T1 we wanted to 1244 single-step. Lacking hardware single-stepping we've 1245 set breakpoint at the PC of the next instruction -- call it 1246 P. After resuming, we've hit that breakpoint in thread T2. 1247 Now we've removed original breakpoint, inserted breakpoint 1248 at P+1, and try to step to advance T2 past breakpoint. 1249 We need to step only T2, as if T1 is allowed to freely run, 1250 it can run past P, and if other threads are allowed to run, 1251 they can hit breakpoint at P+1, and nested hits of single-step 1252 breakpoints is not something we'd want -- that's complicated 1253 to support, and has no value. */ 1254 resume_ptid = inferior_ptid; 1255 } 1256 else if ((step || singlestep_breakpoints_inserted_p) 1257 && tp->trap_expected) 1258 { 1259 /* We're allowing a thread to run past a breakpoint it has 1260 hit, by single-stepping the thread with the breakpoint 1261 removed. In which case, we need to single-step only this 1262 thread, and keep others stopped, as they can miss this 1263 breakpoint if allowed to run. 1264 1265 The current code actually removes all breakpoints when 1266 doing this, not just the one being stepped over, so if we 1267 let other threads run, we can actually miss any 1268 breakpoint, not just the one at PC. */ 1269 resume_ptid = inferior_ptid; 1270 } 1271 else if (non_stop) 1272 { 1273 /* With non-stop mode on, threads are always handled 1274 individually. */ 1275 resume_ptid = inferior_ptid; 1276 } 1277 else if ((scheduler_mode == schedlock_on) 1278 || (scheduler_mode == schedlock_step 1279 && (step || singlestep_breakpoints_inserted_p))) 1280 { 1281 /* User-settable 'scheduler' mode requires solo thread resume. */ 1282 resume_ptid = inferior_ptid; 1283 } 1284 1285 if (gdbarch_cannot_step_breakpoint (gdbarch)) 1286 { 1287 /* Most targets can step a breakpoint instruction, thus 1288 executing it normally. But if this one cannot, just 1289 continue and we will hit it anyway. */ 1290 if (step && breakpoint_inserted_here_p (pc)) 1291 step = 0; 1292 } 1293 1294 if (debug_displaced 1295 && use_displaced_stepping (gdbarch) 1296 && tp->trap_expected) 1297 { 1298 struct regcache *resume_regcache = get_thread_regcache (resume_ptid); 1299 struct gdbarch *resume_gdbarch = get_regcache_arch (resume_regcache); 1300 CORE_ADDR actual_pc = regcache_read_pc (resume_regcache); 1301 gdb_byte buf[4]; 1302 1303 fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ", 1304 paddress (resume_gdbarch, actual_pc)); 1305 read_memory (actual_pc, buf, sizeof (buf)); 1306 displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf)); 1307 } 1308 1309 /* Install inferior's terminal modes. */ 1310 target_terminal_inferior (); 1311 1312 /* Avoid confusing the next resume, if the next stop/resume 1313 happens to apply to another thread. */ 1314 tp->stop_signal = TARGET_SIGNAL_0; 1315 1316 target_resume (resume_ptid, step, sig); 1317 } 1318 1319 discard_cleanups (old_cleanups); 1320 } 1321 1322 /* Proceeding. */ 1323 1324 /* Clear out all variables saying what to do when inferior is continued. 1325 First do this, then set the ones you want, then call `proceed'. */ 1326 1327 static void 1328 clear_proceed_status_thread (struct thread_info *tp) 1329 { 1330 if (debug_infrun) 1331 fprintf_unfiltered (gdb_stdlog, 1332 "infrun: clear_proceed_status_thread (%s)\n", 1333 target_pid_to_str (tp->ptid)); 1334 1335 tp->trap_expected = 0; 1336 tp->step_range_start = 0; 1337 tp->step_range_end = 0; 1338 tp->step_frame_id = null_frame_id; 1339 tp->step_stack_frame_id = null_frame_id; 1340 tp->step_over_calls = STEP_OVER_UNDEBUGGABLE; 1341 tp->stop_requested = 0; 1342 1343 tp->stop_step = 0; 1344 1345 tp->proceed_to_finish = 0; 1346 1347 /* Discard any remaining commands or status from previous stop. */ 1348 bpstat_clear (&tp->stop_bpstat); 1349 } 1350 1351 static int 1352 clear_proceed_status_callback (struct thread_info *tp, void *data) 1353 { 1354 if (is_exited (tp->ptid)) 1355 return 0; 1356 1357 clear_proceed_status_thread (tp); 1358 return 0; 1359 } 1360 1361 void 1362 clear_proceed_status (void) 1363 { 1364 if (!ptid_equal (inferior_ptid, null_ptid)) 1365 { 1366 struct inferior *inferior; 1367 1368 if (non_stop) 1369 { 1370 /* If in non-stop mode, only delete the per-thread status 1371 of the current thread. */ 1372 clear_proceed_status_thread (inferior_thread ()); 1373 } 1374 else 1375 { 1376 /* In all-stop mode, delete the per-thread status of 1377 *all* threads. */ 1378 iterate_over_threads (clear_proceed_status_callback, NULL); 1379 } 1380 1381 inferior = current_inferior (); 1382 inferior->stop_soon = NO_STOP_QUIETLY; 1383 } 1384 1385 stop_after_trap = 0; 1386 1387 observer_notify_about_to_proceed (); 1388 1389 if (stop_registers) 1390 { 1391 regcache_xfree (stop_registers); 1392 stop_registers = NULL; 1393 } 1394 } 1395 1396 /* Check the current thread against the thread that reported the most recent 1397 event. If a step-over is required return TRUE and set the current thread 1398 to the old thread. Otherwise return FALSE. 1399 1400 This should be suitable for any targets that support threads. */ 1401 1402 static int 1403 prepare_to_proceed (int step) 1404 { 1405 ptid_t wait_ptid; 1406 struct target_waitstatus wait_status; 1407 int schedlock_enabled; 1408 1409 /* With non-stop mode on, threads are always handled individually. */ 1410 gdb_assert (! non_stop); 1411 1412 /* Get the last target status returned by target_wait(). */ 1413 get_last_target_status (&wait_ptid, &wait_status); 1414 1415 /* Make sure we were stopped at a breakpoint. */ 1416 if (wait_status.kind != TARGET_WAITKIND_STOPPED 1417 || wait_status.value.sig != TARGET_SIGNAL_TRAP) 1418 { 1419 return 0; 1420 } 1421 1422 schedlock_enabled = (scheduler_mode == schedlock_on 1423 || (scheduler_mode == schedlock_step 1424 && step)); 1425 1426 /* Don't switch over to WAIT_PTID if scheduler locking is on. */ 1427 if (schedlock_enabled) 1428 return 0; 1429 1430 /* Don't switch over if we're about to resume some other process 1431 other than WAIT_PTID's, and schedule-multiple is off. */ 1432 if (!sched_multi 1433 && ptid_get_pid (wait_ptid) != ptid_get_pid (inferior_ptid)) 1434 return 0; 1435 1436 /* Switched over from WAIT_PID. */ 1437 if (!ptid_equal (wait_ptid, minus_one_ptid) 1438 && !ptid_equal (inferior_ptid, wait_ptid)) 1439 { 1440 struct regcache *regcache = get_thread_regcache (wait_ptid); 1441 1442 if (breakpoint_here_p (regcache_read_pc (regcache))) 1443 { 1444 /* If stepping, remember current thread to switch back to. */ 1445 if (step) 1446 deferred_step_ptid = inferior_ptid; 1447 1448 /* Switch back to WAIT_PID thread. */ 1449 switch_to_thread (wait_ptid); 1450 1451 /* We return 1 to indicate that there is a breakpoint here, 1452 so we need to step over it before continuing to avoid 1453 hitting it straight away. */ 1454 return 1; 1455 } 1456 } 1457 1458 return 0; 1459 } 1460 1461 /* Basic routine for continuing the program in various fashions. 1462 1463 ADDR is the address to resume at, or -1 for resume where stopped. 1464 SIGGNAL is the signal to give it, or 0 for none, 1465 or -1 for act according to how it stopped. 1466 STEP is nonzero if should trap after one instruction. 1467 -1 means return after that and print nothing. 1468 You should probably set various step_... variables 1469 before calling here, if you are stepping. 1470 1471 You should call clear_proceed_status before calling proceed. */ 1472 1473 void 1474 proceed (CORE_ADDR addr, enum target_signal siggnal, int step) 1475 { 1476 struct regcache *regcache; 1477 struct gdbarch *gdbarch; 1478 struct thread_info *tp; 1479 CORE_ADDR pc; 1480 int oneproc = 0; 1481 1482 /* If we're stopped at a fork/vfork, follow the branch set by the 1483 "set follow-fork-mode" command; otherwise, we'll just proceed 1484 resuming the current thread. */ 1485 if (!follow_fork ()) 1486 { 1487 /* The target for some reason decided not to resume. */ 1488 normal_stop (); 1489 return; 1490 } 1491 1492 regcache = get_current_regcache (); 1493 gdbarch = get_regcache_arch (regcache); 1494 pc = regcache_read_pc (regcache); 1495 1496 if (step > 0) 1497 step_start_function = find_pc_function (pc); 1498 if (step < 0) 1499 stop_after_trap = 1; 1500 1501 if (addr == (CORE_ADDR) -1) 1502 { 1503 if (pc == stop_pc && breakpoint_here_p (pc) 1504 && execution_direction != EXEC_REVERSE) 1505 /* There is a breakpoint at the address we will resume at, 1506 step one instruction before inserting breakpoints so that 1507 we do not stop right away (and report a second hit at this 1508 breakpoint). 1509 1510 Note, we don't do this in reverse, because we won't 1511 actually be executing the breakpoint insn anyway. 1512 We'll be (un-)executing the previous instruction. */ 1513 1514 oneproc = 1; 1515 else if (gdbarch_single_step_through_delay_p (gdbarch) 1516 && gdbarch_single_step_through_delay (gdbarch, 1517 get_current_frame ())) 1518 /* We stepped onto an instruction that needs to be stepped 1519 again before re-inserting the breakpoint, do so. */ 1520 oneproc = 1; 1521 } 1522 else 1523 { 1524 regcache_write_pc (regcache, addr); 1525 } 1526 1527 if (debug_infrun) 1528 fprintf_unfiltered (gdb_stdlog, 1529 "infrun: proceed (addr=%s, signal=%d, step=%d)\n", 1530 paddress (gdbarch, addr), siggnal, step); 1531 1532 if (non_stop) 1533 /* In non-stop, each thread is handled individually. The context 1534 must already be set to the right thread here. */ 1535 ; 1536 else 1537 { 1538 /* In a multi-threaded task we may select another thread and 1539 then continue or step. 1540 1541 But if the old thread was stopped at a breakpoint, it will 1542 immediately cause another breakpoint stop without any 1543 execution (i.e. it will report a breakpoint hit incorrectly). 1544 So we must step over it first. 1545 1546 prepare_to_proceed checks the current thread against the 1547 thread that reported the most recent event. If a step-over 1548 is required it returns TRUE and sets the current thread to 1549 the old thread. */ 1550 if (prepare_to_proceed (step)) 1551 oneproc = 1; 1552 } 1553 1554 /* prepare_to_proceed may change the current thread. */ 1555 tp = inferior_thread (); 1556 1557 if (oneproc) 1558 { 1559 tp->trap_expected = 1; 1560 /* If displaced stepping is enabled, we can step over the 1561 breakpoint without hitting it, so leave all breakpoints 1562 inserted. Otherwise we need to disable all breakpoints, step 1563 one instruction, and then re-add them when that step is 1564 finished. */ 1565 if (!use_displaced_stepping (gdbarch)) 1566 remove_breakpoints (); 1567 } 1568 1569 /* We can insert breakpoints if we're not trying to step over one, 1570 or if we are stepping over one but we're using displaced stepping 1571 to do so. */ 1572 if (! tp->trap_expected || use_displaced_stepping (gdbarch)) 1573 insert_breakpoints (); 1574 1575 if (!non_stop) 1576 { 1577 /* Pass the last stop signal to the thread we're resuming, 1578 irrespective of whether the current thread is the thread that 1579 got the last event or not. This was historically GDB's 1580 behaviour before keeping a stop_signal per thread. */ 1581 1582 struct thread_info *last_thread; 1583 ptid_t last_ptid; 1584 struct target_waitstatus last_status; 1585 1586 get_last_target_status (&last_ptid, &last_status); 1587 if (!ptid_equal (inferior_ptid, last_ptid) 1588 && !ptid_equal (last_ptid, null_ptid) 1589 && !ptid_equal (last_ptid, minus_one_ptid)) 1590 { 1591 last_thread = find_thread_ptid (last_ptid); 1592 if (last_thread) 1593 { 1594 tp->stop_signal = last_thread->stop_signal; 1595 last_thread->stop_signal = TARGET_SIGNAL_0; 1596 } 1597 } 1598 } 1599 1600 if (siggnal != TARGET_SIGNAL_DEFAULT) 1601 tp->stop_signal = siggnal; 1602 /* If this signal should not be seen by program, 1603 give it zero. Used for debugging signals. */ 1604 else if (!signal_program[tp->stop_signal]) 1605 tp->stop_signal = TARGET_SIGNAL_0; 1606 1607 annotate_starting (); 1608 1609 /* Make sure that output from GDB appears before output from the 1610 inferior. */ 1611 gdb_flush (gdb_stdout); 1612 1613 /* Refresh prev_pc value just prior to resuming. This used to be 1614 done in stop_stepping, however, setting prev_pc there did not handle 1615 scenarios such as inferior function calls or returning from 1616 a function via the return command. In those cases, the prev_pc 1617 value was not set properly for subsequent commands. The prev_pc value 1618 is used to initialize the starting line number in the ecs. With an 1619 invalid value, the gdb next command ends up stopping at the position 1620 represented by the next line table entry past our start position. 1621 On platforms that generate one line table entry per line, this 1622 is not a problem. However, on the ia64, the compiler generates 1623 extraneous line table entries that do not increase the line number. 1624 When we issue the gdb next command on the ia64 after an inferior call 1625 or a return command, we often end up a few instructions forward, still 1626 within the original line we started. 1627 1628 An attempt was made to have init_execution_control_state () refresh 1629 the prev_pc value before calculating the line number. This approach 1630 did not work because on platforms that use ptrace, the pc register 1631 cannot be read unless the inferior is stopped. At that point, we 1632 are not guaranteed the inferior is stopped and so the regcache_read_pc () 1633 call can fail. Setting the prev_pc value here ensures the value is 1634 updated correctly when the inferior is stopped. */ 1635 tp->prev_pc = regcache_read_pc (get_current_regcache ()); 1636 1637 /* Fill in with reasonable starting values. */ 1638 init_thread_stepping_state (tp); 1639 1640 /* Reset to normal state. */ 1641 init_infwait_state (); 1642 1643 /* Resume inferior. */ 1644 resume (oneproc || step || bpstat_should_step (), tp->stop_signal); 1645 1646 /* Wait for it to stop (if not standalone) 1647 and in any case decode why it stopped, and act accordingly. */ 1648 /* Do this only if we are not using the event loop, or if the target 1649 does not support asynchronous execution. */ 1650 if (!target_can_async_p ()) 1651 { 1652 wait_for_inferior (0); 1653 normal_stop (); 1654 } 1655 } 1656 1657 1658 /* Start remote-debugging of a machine over a serial link. */ 1659 1660 void 1661 start_remote (int from_tty) 1662 { 1663 struct inferior *inferior; 1664 init_wait_for_inferior (); 1665 1666 inferior = current_inferior (); 1667 inferior->stop_soon = STOP_QUIETLY_REMOTE; 1668 1669 /* Always go on waiting for the target, regardless of the mode. */ 1670 /* FIXME: cagney/1999-09-23: At present it isn't possible to 1671 indicate to wait_for_inferior that a target should timeout if 1672 nothing is returned (instead of just blocking). Because of this, 1673 targets expecting an immediate response need to, internally, set 1674 things up so that the target_wait() is forced to eventually 1675 timeout. */ 1676 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to 1677 differentiate to its caller what the state of the target is after 1678 the initial open has been performed. Here we're assuming that 1679 the target has stopped. It should be possible to eventually have 1680 target_open() return to the caller an indication that the target 1681 is currently running and GDB state should be set to the same as 1682 for an async run. */ 1683 wait_for_inferior (0); 1684 1685 /* Now that the inferior has stopped, do any bookkeeping like 1686 loading shared libraries. We want to do this before normal_stop, 1687 so that the displayed frame is up to date. */ 1688 post_create_inferior (¤t_target, from_tty); 1689 1690 normal_stop (); 1691 } 1692 1693 /* Initialize static vars when a new inferior begins. */ 1694 1695 void 1696 init_wait_for_inferior (void) 1697 { 1698 /* These are meaningless until the first time through wait_for_inferior. */ 1699 1700 breakpoint_init_inferior (inf_starting); 1701 1702 clear_proceed_status (); 1703 1704 stepping_past_singlestep_breakpoint = 0; 1705 deferred_step_ptid = null_ptid; 1706 1707 target_last_wait_ptid = minus_one_ptid; 1708 1709 previous_inferior_ptid = null_ptid; 1710 init_infwait_state (); 1711 1712 displaced_step_clear (); 1713 1714 /* Discard any skipped inlined frames. */ 1715 clear_inline_frame_state (minus_one_ptid); 1716 } 1717 1718 1719 /* This enum encodes possible reasons for doing a target_wait, so that 1720 wfi can call target_wait in one place. (Ultimately the call will be 1721 moved out of the infinite loop entirely.) */ 1722 1723 enum infwait_states 1724 { 1725 infwait_normal_state, 1726 infwait_thread_hop_state, 1727 infwait_step_watch_state, 1728 infwait_nonstep_watch_state 1729 }; 1730 1731 /* Why did the inferior stop? Used to print the appropriate messages 1732 to the interface from within handle_inferior_event(). */ 1733 enum inferior_stop_reason 1734 { 1735 /* Step, next, nexti, stepi finished. */ 1736 END_STEPPING_RANGE, 1737 /* Inferior terminated by signal. */ 1738 SIGNAL_EXITED, 1739 /* Inferior exited. */ 1740 EXITED, 1741 /* Inferior received signal, and user asked to be notified. */ 1742 SIGNAL_RECEIVED, 1743 /* Reverse execution -- target ran out of history info. */ 1744 NO_HISTORY 1745 }; 1746 1747 /* The PTID we'll do a target_wait on.*/ 1748 ptid_t waiton_ptid; 1749 1750 /* Current inferior wait state. */ 1751 enum infwait_states infwait_state; 1752 1753 /* Data to be passed around while handling an event. This data is 1754 discarded between events. */ 1755 struct execution_control_state 1756 { 1757 ptid_t ptid; 1758 /* The thread that got the event, if this was a thread event; NULL 1759 otherwise. */ 1760 struct thread_info *event_thread; 1761 1762 struct target_waitstatus ws; 1763 int random_signal; 1764 CORE_ADDR stop_func_start; 1765 CORE_ADDR stop_func_end; 1766 char *stop_func_name; 1767 int new_thread_event; 1768 int wait_some_more; 1769 }; 1770 1771 static void init_execution_control_state (struct execution_control_state *ecs); 1772 1773 static void handle_inferior_event (struct execution_control_state *ecs); 1774 1775 static void handle_step_into_function (struct gdbarch *gdbarch, 1776 struct execution_control_state *ecs); 1777 static void handle_step_into_function_backward (struct gdbarch *gdbarch, 1778 struct execution_control_state *ecs); 1779 static void insert_step_resume_breakpoint_at_frame (struct frame_info *step_frame); 1780 static void insert_step_resume_breakpoint_at_caller (struct frame_info *); 1781 static void insert_step_resume_breakpoint_at_sal (struct gdbarch *gdbarch, 1782 struct symtab_and_line sr_sal, 1783 struct frame_id sr_id); 1784 static void insert_longjmp_resume_breakpoint (struct gdbarch *, CORE_ADDR); 1785 1786 static void stop_stepping (struct execution_control_state *ecs); 1787 static void prepare_to_wait (struct execution_control_state *ecs); 1788 static void keep_going (struct execution_control_state *ecs); 1789 static void print_stop_reason (enum inferior_stop_reason stop_reason, 1790 int stop_info); 1791 1792 /* Callback for iterate over threads. If the thread is stopped, but 1793 the user/frontend doesn't know about that yet, go through 1794 normal_stop, as if the thread had just stopped now. ARG points at 1795 a ptid. If PTID is MINUS_ONE_PTID, applies to all threads. If 1796 ptid_is_pid(PTID) is true, applies to all threads of the process 1797 pointed at by PTID. Otherwise, apply only to the thread pointed by 1798 PTID. */ 1799 1800 static int 1801 infrun_thread_stop_requested_callback (struct thread_info *info, void *arg) 1802 { 1803 ptid_t ptid = * (ptid_t *) arg; 1804 1805 if ((ptid_equal (info->ptid, ptid) 1806 || ptid_equal (minus_one_ptid, ptid) 1807 || (ptid_is_pid (ptid) 1808 && ptid_get_pid (ptid) == ptid_get_pid (info->ptid))) 1809 && is_running (info->ptid) 1810 && !is_executing (info->ptid)) 1811 { 1812 struct cleanup *old_chain; 1813 struct execution_control_state ecss; 1814 struct execution_control_state *ecs = &ecss; 1815 1816 memset (ecs, 0, sizeof (*ecs)); 1817 1818 old_chain = make_cleanup_restore_current_thread (); 1819 1820 switch_to_thread (info->ptid); 1821 1822 /* Go through handle_inferior_event/normal_stop, so we always 1823 have consistent output as if the stop event had been 1824 reported. */ 1825 ecs->ptid = info->ptid; 1826 ecs->event_thread = find_thread_ptid (info->ptid); 1827 ecs->ws.kind = TARGET_WAITKIND_STOPPED; 1828 ecs->ws.value.sig = TARGET_SIGNAL_0; 1829 1830 handle_inferior_event (ecs); 1831 1832 if (!ecs->wait_some_more) 1833 { 1834 struct thread_info *tp; 1835 1836 normal_stop (); 1837 1838 /* Finish off the continuations. The continations 1839 themselves are responsible for realising the thread 1840 didn't finish what it was supposed to do. */ 1841 tp = inferior_thread (); 1842 do_all_intermediate_continuations_thread (tp); 1843 do_all_continuations_thread (tp); 1844 } 1845 1846 do_cleanups (old_chain); 1847 } 1848 1849 return 0; 1850 } 1851 1852 /* This function is attached as a "thread_stop_requested" observer. 1853 Cleanup local state that assumed the PTID was to be resumed, and 1854 report the stop to the frontend. */ 1855 1856 static void 1857 infrun_thread_stop_requested (ptid_t ptid) 1858 { 1859 struct displaced_step_request *it, *next, *prev = NULL; 1860 1861 /* PTID was requested to stop. Remove it from the displaced 1862 stepping queue, so we don't try to resume it automatically. */ 1863 for (it = displaced_step_request_queue; it; it = next) 1864 { 1865 next = it->next; 1866 1867 if (ptid_equal (it->ptid, ptid) 1868 || ptid_equal (minus_one_ptid, ptid) 1869 || (ptid_is_pid (ptid) 1870 && ptid_get_pid (ptid) == ptid_get_pid (it->ptid))) 1871 { 1872 if (displaced_step_request_queue == it) 1873 displaced_step_request_queue = it->next; 1874 else 1875 prev->next = it->next; 1876 1877 xfree (it); 1878 } 1879 else 1880 prev = it; 1881 } 1882 1883 iterate_over_threads (infrun_thread_stop_requested_callback, &ptid); 1884 } 1885 1886 static void 1887 infrun_thread_thread_exit (struct thread_info *tp, int silent) 1888 { 1889 if (ptid_equal (target_last_wait_ptid, tp->ptid)) 1890 nullify_last_target_wait_ptid (); 1891 } 1892 1893 /* Callback for iterate_over_threads. */ 1894 1895 static int 1896 delete_step_resume_breakpoint_callback (struct thread_info *info, void *data) 1897 { 1898 if (is_exited (info->ptid)) 1899 return 0; 1900 1901 delete_step_resume_breakpoint (info); 1902 return 0; 1903 } 1904 1905 /* In all-stop, delete the step resume breakpoint of any thread that 1906 had one. In non-stop, delete the step resume breakpoint of the 1907 thread that just stopped. */ 1908 1909 static void 1910 delete_step_thread_step_resume_breakpoint (void) 1911 { 1912 if (!target_has_execution 1913 || ptid_equal (inferior_ptid, null_ptid)) 1914 /* If the inferior has exited, we have already deleted the step 1915 resume breakpoints out of GDB's lists. */ 1916 return; 1917 1918 if (non_stop) 1919 { 1920 /* If in non-stop mode, only delete the step-resume or 1921 longjmp-resume breakpoint of the thread that just stopped 1922 stepping. */ 1923 struct thread_info *tp = inferior_thread (); 1924 delete_step_resume_breakpoint (tp); 1925 } 1926 else 1927 /* In all-stop mode, delete all step-resume and longjmp-resume 1928 breakpoints of any thread that had them. */ 1929 iterate_over_threads (delete_step_resume_breakpoint_callback, NULL); 1930 } 1931 1932 /* A cleanup wrapper. */ 1933 1934 static void 1935 delete_step_thread_step_resume_breakpoint_cleanup (void *arg) 1936 { 1937 delete_step_thread_step_resume_breakpoint (); 1938 } 1939 1940 /* Pretty print the results of target_wait, for debugging purposes. */ 1941 1942 static void 1943 print_target_wait_results (ptid_t waiton_ptid, ptid_t result_ptid, 1944 const struct target_waitstatus *ws) 1945 { 1946 char *status_string = target_waitstatus_to_string (ws); 1947 struct ui_file *tmp_stream = mem_fileopen (); 1948 char *text; 1949 1950 /* The text is split over several lines because it was getting too long. 1951 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still 1952 output as a unit; we want only one timestamp printed if debug_timestamp 1953 is set. */ 1954 1955 fprintf_unfiltered (tmp_stream, 1956 "infrun: target_wait (%d", PIDGET (waiton_ptid)); 1957 if (PIDGET (waiton_ptid) != -1) 1958 fprintf_unfiltered (tmp_stream, 1959 " [%s]", target_pid_to_str (waiton_ptid)); 1960 fprintf_unfiltered (tmp_stream, ", status) =\n"); 1961 fprintf_unfiltered (tmp_stream, 1962 "infrun: %d [%s],\n", 1963 PIDGET (result_ptid), target_pid_to_str (result_ptid)); 1964 fprintf_unfiltered (tmp_stream, 1965 "infrun: %s\n", 1966 status_string); 1967 1968 text = ui_file_xstrdup (tmp_stream, NULL); 1969 1970 /* This uses %s in part to handle %'s in the text, but also to avoid 1971 a gcc error: the format attribute requires a string literal. */ 1972 fprintf_unfiltered (gdb_stdlog, "%s", text); 1973 1974 xfree (status_string); 1975 xfree (text); 1976 ui_file_delete (tmp_stream); 1977 } 1978 1979 /* Wait for control to return from inferior to debugger. 1980 1981 If TREAT_EXEC_AS_SIGTRAP is non-zero, then handle EXEC signals 1982 as if they were SIGTRAP signals. This can be useful during 1983 the startup sequence on some targets such as HP/UX, where 1984 we receive an EXEC event instead of the expected SIGTRAP. 1985 1986 If inferior gets a signal, we may decide to start it up again 1987 instead of returning. That is why there is a loop in this function. 1988 When this function actually returns it means the inferior 1989 should be left stopped and GDB should read more commands. */ 1990 1991 void 1992 wait_for_inferior (int treat_exec_as_sigtrap) 1993 { 1994 struct cleanup *old_cleanups; 1995 struct execution_control_state ecss; 1996 struct execution_control_state *ecs; 1997 1998 if (debug_infrun) 1999 fprintf_unfiltered 2000 (gdb_stdlog, "infrun: wait_for_inferior (treat_exec_as_sigtrap=%d)\n", 2001 treat_exec_as_sigtrap); 2002 2003 old_cleanups = 2004 make_cleanup (delete_step_thread_step_resume_breakpoint_cleanup, NULL); 2005 2006 ecs = &ecss; 2007 memset (ecs, 0, sizeof (*ecs)); 2008 2009 /* We'll update this if & when we switch to a new thread. */ 2010 previous_inferior_ptid = inferior_ptid; 2011 2012 while (1) 2013 { 2014 struct cleanup *old_chain; 2015 2016 /* We have to invalidate the registers BEFORE calling target_wait 2017 because they can be loaded from the target while in target_wait. 2018 This makes remote debugging a bit more efficient for those 2019 targets that provide critical registers as part of their normal 2020 status mechanism. */ 2021 2022 overlay_cache_invalid = 1; 2023 registers_changed (); 2024 2025 if (deprecated_target_wait_hook) 2026 ecs->ptid = deprecated_target_wait_hook (waiton_ptid, &ecs->ws, 0); 2027 else 2028 ecs->ptid = target_wait (waiton_ptid, &ecs->ws, 0); 2029 2030 if (debug_infrun) 2031 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws); 2032 2033 if (treat_exec_as_sigtrap && ecs->ws.kind == TARGET_WAITKIND_EXECD) 2034 { 2035 xfree (ecs->ws.value.execd_pathname); 2036 ecs->ws.kind = TARGET_WAITKIND_STOPPED; 2037 ecs->ws.value.sig = TARGET_SIGNAL_TRAP; 2038 } 2039 2040 /* If an error happens while handling the event, propagate GDB's 2041 knowledge of the executing state to the frontend/user running 2042 state. */ 2043 old_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid); 2044 2045 if (ecs->ws.kind == TARGET_WAITKIND_SYSCALL_ENTRY 2046 || ecs->ws.kind == TARGET_WAITKIND_SYSCALL_RETURN) 2047 ecs->ws.value.syscall_number = UNKNOWN_SYSCALL; 2048 2049 /* Now figure out what to do with the result of the result. */ 2050 handle_inferior_event (ecs); 2051 2052 /* No error, don't finish the state yet. */ 2053 discard_cleanups (old_chain); 2054 2055 if (!ecs->wait_some_more) 2056 break; 2057 } 2058 2059 do_cleanups (old_cleanups); 2060 } 2061 2062 /* Asynchronous version of wait_for_inferior. It is called by the 2063 event loop whenever a change of state is detected on the file 2064 descriptor corresponding to the target. It can be called more than 2065 once to complete a single execution command. In such cases we need 2066 to keep the state in a global variable ECSS. If it is the last time 2067 that this function is called for a single execution command, then 2068 report to the user that the inferior has stopped, and do the 2069 necessary cleanups. */ 2070 2071 void 2072 fetch_inferior_event (void *client_data) 2073 { 2074 struct execution_control_state ecss; 2075 struct execution_control_state *ecs = &ecss; 2076 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL); 2077 struct cleanup *ts_old_chain; 2078 int was_sync = sync_execution; 2079 2080 memset (ecs, 0, sizeof (*ecs)); 2081 2082 /* We'll update this if & when we switch to a new thread. */ 2083 previous_inferior_ptid = inferior_ptid; 2084 2085 if (non_stop) 2086 /* In non-stop mode, the user/frontend should not notice a thread 2087 switch due to internal events. Make sure we reverse to the 2088 user selected thread and frame after handling the event and 2089 running any breakpoint commands. */ 2090 make_cleanup_restore_current_thread (); 2091 2092 /* We have to invalidate the registers BEFORE calling target_wait 2093 because they can be loaded from the target while in target_wait. 2094 This makes remote debugging a bit more efficient for those 2095 targets that provide critical registers as part of their normal 2096 status mechanism. */ 2097 2098 overlay_cache_invalid = 1; 2099 registers_changed (); 2100 2101 if (deprecated_target_wait_hook) 2102 ecs->ptid = 2103 deprecated_target_wait_hook (waiton_ptid, &ecs->ws, TARGET_WNOHANG); 2104 else 2105 ecs->ptid = target_wait (waiton_ptid, &ecs->ws, TARGET_WNOHANG); 2106 2107 if (debug_infrun) 2108 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws); 2109 2110 if (non_stop 2111 && ecs->ws.kind != TARGET_WAITKIND_IGNORE 2112 && ecs->ws.kind != TARGET_WAITKIND_EXITED 2113 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED) 2114 /* In non-stop mode, each thread is handled individually. Switch 2115 early, so the global state is set correctly for this 2116 thread. */ 2117 context_switch (ecs->ptid); 2118 2119 /* If an error happens while handling the event, propagate GDB's 2120 knowledge of the executing state to the frontend/user running 2121 state. */ 2122 if (!non_stop) 2123 ts_old_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid); 2124 else 2125 ts_old_chain = make_cleanup (finish_thread_state_cleanup, &ecs->ptid); 2126 2127 /* Now figure out what to do with the result of the result. */ 2128 handle_inferior_event (ecs); 2129 2130 if (!ecs->wait_some_more) 2131 { 2132 struct inferior *inf = find_inferior_pid (ptid_get_pid (ecs->ptid)); 2133 2134 delete_step_thread_step_resume_breakpoint (); 2135 2136 /* We may not find an inferior if this was a process exit. */ 2137 if (inf == NULL || inf->stop_soon == NO_STOP_QUIETLY) 2138 normal_stop (); 2139 2140 if (target_has_execution 2141 && ecs->ws.kind != TARGET_WAITKIND_EXITED 2142 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED 2143 && ecs->event_thread->step_multi 2144 && ecs->event_thread->stop_step) 2145 inferior_event_handler (INF_EXEC_CONTINUE, NULL); 2146 else 2147 inferior_event_handler (INF_EXEC_COMPLETE, NULL); 2148 } 2149 2150 /* No error, don't finish the thread states yet. */ 2151 discard_cleanups (ts_old_chain); 2152 2153 /* Revert thread and frame. */ 2154 do_cleanups (old_chain); 2155 2156 /* If the inferior was in sync execution mode, and now isn't, 2157 restore the prompt. */ 2158 if (was_sync && !sync_execution) 2159 display_gdb_prompt (0); 2160 } 2161 2162 /* Record the frame and location we're currently stepping through. */ 2163 void 2164 set_step_info (struct frame_info *frame, struct symtab_and_line sal) 2165 { 2166 struct thread_info *tp = inferior_thread (); 2167 2168 tp->step_frame_id = get_frame_id (frame); 2169 tp->step_stack_frame_id = get_stack_frame_id (frame); 2170 2171 tp->current_symtab = sal.symtab; 2172 tp->current_line = sal.line; 2173 } 2174 2175 /* Prepare an execution control state for looping through a 2176 wait_for_inferior-type loop. */ 2177 2178 static void 2179 init_execution_control_state (struct execution_control_state *ecs) 2180 { 2181 ecs->random_signal = 0; 2182 } 2183 2184 /* Clear context switchable stepping state. */ 2185 2186 void 2187 init_thread_stepping_state (struct thread_info *tss) 2188 { 2189 tss->stepping_over_breakpoint = 0; 2190 tss->step_after_step_resume_breakpoint = 0; 2191 tss->stepping_through_solib_after_catch = 0; 2192 tss->stepping_through_solib_catchpoints = NULL; 2193 } 2194 2195 /* Return the cached copy of the last pid/waitstatus returned by 2196 target_wait()/deprecated_target_wait_hook(). The data is actually 2197 cached by handle_inferior_event(), which gets called immediately 2198 after target_wait()/deprecated_target_wait_hook(). */ 2199 2200 void 2201 get_last_target_status (ptid_t *ptidp, struct target_waitstatus *status) 2202 { 2203 *ptidp = target_last_wait_ptid; 2204 *status = target_last_waitstatus; 2205 } 2206 2207 void 2208 nullify_last_target_wait_ptid (void) 2209 { 2210 target_last_wait_ptid = minus_one_ptid; 2211 } 2212 2213 /* Switch thread contexts. */ 2214 2215 static void 2216 context_switch (ptid_t ptid) 2217 { 2218 if (debug_infrun) 2219 { 2220 fprintf_unfiltered (gdb_stdlog, "infrun: Switching context from %s ", 2221 target_pid_to_str (inferior_ptid)); 2222 fprintf_unfiltered (gdb_stdlog, "to %s\n", 2223 target_pid_to_str (ptid)); 2224 } 2225 2226 switch_to_thread (ptid); 2227 } 2228 2229 static void 2230 adjust_pc_after_break (struct execution_control_state *ecs) 2231 { 2232 struct regcache *regcache; 2233 struct gdbarch *gdbarch; 2234 CORE_ADDR breakpoint_pc; 2235 2236 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If 2237 we aren't, just return. 2238 2239 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not 2240 affected by gdbarch_decr_pc_after_break. Other waitkinds which are 2241 implemented by software breakpoints should be handled through the normal 2242 breakpoint layer. 2243 2244 NOTE drow/2004-01-31: On some targets, breakpoints may generate 2245 different signals (SIGILL or SIGEMT for instance), but it is less 2246 clear where the PC is pointing afterwards. It may not match 2247 gdbarch_decr_pc_after_break. I don't know any specific target that 2248 generates these signals at breakpoints (the code has been in GDB since at 2249 least 1992) so I can not guess how to handle them here. 2250 2251 In earlier versions of GDB, a target with 2252 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a 2253 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any 2254 target with both of these set in GDB history, and it seems unlikely to be 2255 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */ 2256 2257 if (ecs->ws.kind != TARGET_WAITKIND_STOPPED) 2258 return; 2259 2260 if (ecs->ws.value.sig != TARGET_SIGNAL_TRAP) 2261 return; 2262 2263 /* In reverse execution, when a breakpoint is hit, the instruction 2264 under it has already been de-executed. The reported PC always 2265 points at the breakpoint address, so adjusting it further would 2266 be wrong. E.g., consider this case on a decr_pc_after_break == 1 2267 architecture: 2268 2269 B1 0x08000000 : INSN1 2270 B2 0x08000001 : INSN2 2271 0x08000002 : INSN3 2272 PC -> 0x08000003 : INSN4 2273 2274 Say you're stopped at 0x08000003 as above. Reverse continuing 2275 from that point should hit B2 as below. Reading the PC when the 2276 SIGTRAP is reported should read 0x08000001 and INSN2 should have 2277 been de-executed already. 2278 2279 B1 0x08000000 : INSN1 2280 B2 PC -> 0x08000001 : INSN2 2281 0x08000002 : INSN3 2282 0x08000003 : INSN4 2283 2284 We can't apply the same logic as for forward execution, because 2285 we would wrongly adjust the PC to 0x08000000, since there's a 2286 breakpoint at PC - 1. We'd then report a hit on B1, although 2287 INSN1 hadn't been de-executed yet. Doing nothing is the correct 2288 behaviour. */ 2289 if (execution_direction == EXEC_REVERSE) 2290 return; 2291 2292 /* If this target does not decrement the PC after breakpoints, then 2293 we have nothing to do. */ 2294 regcache = get_thread_regcache (ecs->ptid); 2295 gdbarch = get_regcache_arch (regcache); 2296 if (gdbarch_decr_pc_after_break (gdbarch) == 0) 2297 return; 2298 2299 /* Find the location where (if we've hit a breakpoint) the 2300 breakpoint would be. */ 2301 breakpoint_pc = regcache_read_pc (regcache) 2302 - gdbarch_decr_pc_after_break (gdbarch); 2303 2304 /* Check whether there actually is a software breakpoint inserted at 2305 that location. 2306 2307 If in non-stop mode, a race condition is possible where we've 2308 removed a breakpoint, but stop events for that breakpoint were 2309 already queued and arrive later. To suppress those spurious 2310 SIGTRAPs, we keep a list of such breakpoint locations for a bit, 2311 and retire them after a number of stop events are reported. */ 2312 if (software_breakpoint_inserted_here_p (breakpoint_pc) 2313 || (non_stop && moribund_breakpoint_here_p (breakpoint_pc))) 2314 { 2315 struct cleanup *old_cleanups = NULL; 2316 if (RECORD_IS_USED) 2317 old_cleanups = record_gdb_operation_disable_set (); 2318 2319 /* When using hardware single-step, a SIGTRAP is reported for both 2320 a completed single-step and a software breakpoint. Need to 2321 differentiate between the two, as the latter needs adjusting 2322 but the former does not. 2323 2324 The SIGTRAP can be due to a completed hardware single-step only if 2325 - we didn't insert software single-step breakpoints 2326 - the thread to be examined is still the current thread 2327 - this thread is currently being stepped 2328 2329 If any of these events did not occur, we must have stopped due 2330 to hitting a software breakpoint, and have to back up to the 2331 breakpoint address. 2332 2333 As a special case, we could have hardware single-stepped a 2334 software breakpoint. In this case (prev_pc == breakpoint_pc), 2335 we also need to back up to the breakpoint address. */ 2336 2337 if (singlestep_breakpoints_inserted_p 2338 || !ptid_equal (ecs->ptid, inferior_ptid) 2339 || !currently_stepping (ecs->event_thread) 2340 || ecs->event_thread->prev_pc == breakpoint_pc) 2341 regcache_write_pc (regcache, breakpoint_pc); 2342 2343 if (RECORD_IS_USED) 2344 do_cleanups (old_cleanups); 2345 } 2346 } 2347 2348 void 2349 init_infwait_state (void) 2350 { 2351 waiton_ptid = pid_to_ptid (-1); 2352 infwait_state = infwait_normal_state; 2353 } 2354 2355 void 2356 error_is_running (void) 2357 { 2358 error (_("\ 2359 Cannot execute this command while the selected thread is running.")); 2360 } 2361 2362 void 2363 ensure_not_running (void) 2364 { 2365 if (is_running (inferior_ptid)) 2366 error_is_running (); 2367 } 2368 2369 static int 2370 stepped_in_from (struct frame_info *frame, struct frame_id step_frame_id) 2371 { 2372 for (frame = get_prev_frame (frame); 2373 frame != NULL; 2374 frame = get_prev_frame (frame)) 2375 { 2376 if (frame_id_eq (get_frame_id (frame), step_frame_id)) 2377 return 1; 2378 if (get_frame_type (frame) != INLINE_FRAME) 2379 break; 2380 } 2381 2382 return 0; 2383 } 2384 2385 /* Auxiliary function that handles syscall entry/return events. 2386 It returns 1 if the inferior should keep going (and GDB 2387 should ignore the event), or 0 if the event deserves to be 2388 processed. */ 2389 static int 2390 deal_with_syscall_event (struct execution_control_state *ecs) 2391 { 2392 struct regcache *regcache = get_thread_regcache (ecs->ptid); 2393 struct gdbarch *gdbarch = get_regcache_arch (regcache); 2394 int syscall_number = gdbarch_get_syscall_number (gdbarch, 2395 ecs->ptid); 2396 target_last_waitstatus.value.syscall_number = syscall_number; 2397 2398 if (catch_syscall_enabled () > 0 2399 && catching_syscall_number (syscall_number) > 0) 2400 { 2401 if (debug_infrun) 2402 fprintf_unfiltered (gdb_stdlog, "infrun: syscall number = '%d'\n", 2403 syscall_number); 2404 ecs->event_thread->stop_signal = TARGET_SIGNAL_TRAP; 2405 2406 if (!ptid_equal (ecs->ptid, inferior_ptid)) 2407 { 2408 context_switch (ecs->ptid); 2409 reinit_frame_cache (); 2410 } 2411 2412 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid)); 2413 2414 ecs->event_thread->stop_bpstat = bpstat_stop_status (stop_pc, ecs->ptid); 2415 2416 ecs->random_signal = !bpstat_explains_signal (ecs->event_thread->stop_bpstat); 2417 2418 /* If no catchpoint triggered for this, then keep going. */ 2419 if (ecs->random_signal) 2420 { 2421 ecs->event_thread->stop_signal = TARGET_SIGNAL_0; 2422 keep_going (ecs); 2423 return 1; 2424 } 2425 return 0; 2426 } 2427 else 2428 { 2429 resume (0, TARGET_SIGNAL_0); 2430 prepare_to_wait (ecs); 2431 return 1; 2432 } 2433 } 2434 2435 /* Given an execution control state that has been freshly filled in 2436 by an event from the inferior, figure out what it means and take 2437 appropriate action. */ 2438 2439 static void 2440 handle_inferior_event (struct execution_control_state *ecs) 2441 { 2442 struct frame_info *frame; 2443 struct gdbarch *gdbarch; 2444 int sw_single_step_trap_p = 0; 2445 int stopped_by_watchpoint; 2446 int stepped_after_stopped_by_watchpoint = 0; 2447 struct symtab_and_line stop_pc_sal; 2448 enum stop_kind stop_soon; 2449 2450 if (ecs->ws.kind != TARGET_WAITKIND_EXITED 2451 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED 2452 && ecs->ws.kind != TARGET_WAITKIND_IGNORE) 2453 { 2454 struct inferior *inf = find_inferior_pid (ptid_get_pid (ecs->ptid)); 2455 gdb_assert (inf); 2456 stop_soon = inf->stop_soon; 2457 } 2458 else 2459 stop_soon = NO_STOP_QUIETLY; 2460 2461 /* Cache the last pid/waitstatus. */ 2462 target_last_wait_ptid = ecs->ptid; 2463 target_last_waitstatus = ecs->ws; 2464 2465 /* Always clear state belonging to the previous time we stopped. */ 2466 stop_stack_dummy = 0; 2467 2468 /* If it's a new process, add it to the thread database */ 2469 2470 ecs->new_thread_event = (!ptid_equal (ecs->ptid, inferior_ptid) 2471 && !ptid_equal (ecs->ptid, minus_one_ptid) 2472 && !in_thread_list (ecs->ptid)); 2473 2474 if (ecs->ws.kind != TARGET_WAITKIND_EXITED 2475 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED && ecs->new_thread_event) 2476 add_thread (ecs->ptid); 2477 2478 ecs->event_thread = find_thread_ptid (ecs->ptid); 2479 2480 /* Dependent on valid ECS->EVENT_THREAD. */ 2481 adjust_pc_after_break (ecs); 2482 2483 /* Dependent on the current PC value modified by adjust_pc_after_break. */ 2484 reinit_frame_cache (); 2485 2486 if (ecs->ws.kind != TARGET_WAITKIND_IGNORE) 2487 { 2488 breakpoint_retire_moribund (); 2489 2490 /* Mark the non-executing threads accordingly. In all-stop, all 2491 threads of all processes are stopped when we get any event 2492 reported. In non-stop mode, only the event thread stops. If 2493 we're handling a process exit in non-stop mode, there's 2494 nothing to do, as threads of the dead process are gone, and 2495 threads of any other process were left running. */ 2496 if (!non_stop) 2497 set_executing (minus_one_ptid, 0); 2498 else if (ecs->ws.kind != TARGET_WAITKIND_SIGNALLED 2499 && ecs->ws.kind != TARGET_WAITKIND_EXITED) 2500 set_executing (inferior_ptid, 0); 2501 } 2502 2503 switch (infwait_state) 2504 { 2505 case infwait_thread_hop_state: 2506 if (debug_infrun) 2507 fprintf_unfiltered (gdb_stdlog, "infrun: infwait_thread_hop_state\n"); 2508 break; 2509 2510 case infwait_normal_state: 2511 if (debug_infrun) 2512 fprintf_unfiltered (gdb_stdlog, "infrun: infwait_normal_state\n"); 2513 break; 2514 2515 case infwait_step_watch_state: 2516 if (debug_infrun) 2517 fprintf_unfiltered (gdb_stdlog, 2518 "infrun: infwait_step_watch_state\n"); 2519 2520 stepped_after_stopped_by_watchpoint = 1; 2521 break; 2522 2523 case infwait_nonstep_watch_state: 2524 if (debug_infrun) 2525 fprintf_unfiltered (gdb_stdlog, 2526 "infrun: infwait_nonstep_watch_state\n"); 2527 insert_breakpoints (); 2528 2529 /* FIXME-maybe: is this cleaner than setting a flag? Does it 2530 handle things like signals arriving and other things happening 2531 in combination correctly? */ 2532 stepped_after_stopped_by_watchpoint = 1; 2533 break; 2534 2535 default: 2536 internal_error (__FILE__, __LINE__, _("bad switch")); 2537 } 2538 2539 infwait_state = infwait_normal_state; 2540 waiton_ptid = pid_to_ptid (-1); 2541 2542 switch (ecs->ws.kind) 2543 { 2544 case TARGET_WAITKIND_LOADED: 2545 if (debug_infrun) 2546 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_LOADED\n"); 2547 /* Ignore gracefully during startup of the inferior, as it might 2548 be the shell which has just loaded some objects, otherwise 2549 add the symbols for the newly loaded objects. Also ignore at 2550 the beginning of an attach or remote session; we will query 2551 the full list of libraries once the connection is 2552 established. */ 2553 if (stop_soon == NO_STOP_QUIETLY) 2554 { 2555 /* Check for any newly added shared libraries if we're 2556 supposed to be adding them automatically. Switch 2557 terminal for any messages produced by 2558 breakpoint_re_set. */ 2559 target_terminal_ours_for_output (); 2560 /* NOTE: cagney/2003-11-25: Make certain that the target 2561 stack's section table is kept up-to-date. Architectures, 2562 (e.g., PPC64), use the section table to perform 2563 operations such as address => section name and hence 2564 require the table to contain all sections (including 2565 those found in shared libraries). */ 2566 #ifdef SOLIB_ADD 2567 SOLIB_ADD (NULL, 0, ¤t_target, auto_solib_add); 2568 #else 2569 solib_add (NULL, 0, ¤t_target, auto_solib_add); 2570 #endif 2571 target_terminal_inferior (); 2572 2573 /* If requested, stop when the dynamic linker notifies 2574 gdb of events. This allows the user to get control 2575 and place breakpoints in initializer routines for 2576 dynamically loaded objects (among other things). */ 2577 if (stop_on_solib_events) 2578 { 2579 stop_stepping (ecs); 2580 return; 2581 } 2582 2583 /* NOTE drow/2007-05-11: This might be a good place to check 2584 for "catch load". */ 2585 } 2586 2587 /* If we are skipping through a shell, or through shared library 2588 loading that we aren't interested in, resume the program. If 2589 we're running the program normally, also resume. But stop if 2590 we're attaching or setting up a remote connection. */ 2591 if (stop_soon == STOP_QUIETLY || stop_soon == NO_STOP_QUIETLY) 2592 { 2593 /* Loading of shared libraries might have changed breakpoint 2594 addresses. Make sure new breakpoints are inserted. */ 2595 if (stop_soon == NO_STOP_QUIETLY 2596 && !breakpoints_always_inserted_mode ()) 2597 insert_breakpoints (); 2598 resume (0, TARGET_SIGNAL_0); 2599 prepare_to_wait (ecs); 2600 return; 2601 } 2602 2603 break; 2604 2605 case TARGET_WAITKIND_SPURIOUS: 2606 if (debug_infrun) 2607 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SPURIOUS\n"); 2608 resume (0, TARGET_SIGNAL_0); 2609 prepare_to_wait (ecs); 2610 return; 2611 2612 case TARGET_WAITKIND_EXITED: 2613 if (debug_infrun) 2614 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_EXITED\n"); 2615 inferior_ptid = ecs->ptid; 2616 target_terminal_ours (); /* Must do this before mourn anyway */ 2617 print_stop_reason (EXITED, ecs->ws.value.integer); 2618 2619 /* Record the exit code in the convenience variable $_exitcode, so 2620 that the user can inspect this again later. */ 2621 set_internalvar_integer (lookup_internalvar ("_exitcode"), 2622 (LONGEST) ecs->ws.value.integer); 2623 gdb_flush (gdb_stdout); 2624 target_mourn_inferior (); 2625 singlestep_breakpoints_inserted_p = 0; 2626 stop_print_frame = 0; 2627 stop_stepping (ecs); 2628 return; 2629 2630 case TARGET_WAITKIND_SIGNALLED: 2631 if (debug_infrun) 2632 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SIGNALLED\n"); 2633 inferior_ptid = ecs->ptid; 2634 stop_print_frame = 0; 2635 target_terminal_ours (); /* Must do this before mourn anyway */ 2636 2637 /* Note: By definition of TARGET_WAITKIND_SIGNALLED, we shouldn't 2638 reach here unless the inferior is dead. However, for years 2639 target_kill() was called here, which hints that fatal signals aren't 2640 really fatal on some systems. If that's true, then some changes 2641 may be needed. */ 2642 target_mourn_inferior (); 2643 2644 print_stop_reason (SIGNAL_EXITED, ecs->ws.value.sig); 2645 singlestep_breakpoints_inserted_p = 0; 2646 stop_stepping (ecs); 2647 return; 2648 2649 /* The following are the only cases in which we keep going; 2650 the above cases end in a continue or goto. */ 2651 case TARGET_WAITKIND_FORKED: 2652 case TARGET_WAITKIND_VFORKED: 2653 if (debug_infrun) 2654 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_FORKED\n"); 2655 2656 if (!ptid_equal (ecs->ptid, inferior_ptid)) 2657 { 2658 context_switch (ecs->ptid); 2659 reinit_frame_cache (); 2660 } 2661 2662 /* Immediately detach breakpoints from the child before there's 2663 any chance of letting the user delete breakpoints from the 2664 breakpoint lists. If we don't do this early, it's easy to 2665 leave left over traps in the child, vis: "break foo; catch 2666 fork; c; <fork>; del; c; <child calls foo>". We only follow 2667 the fork on the last `continue', and by that time the 2668 breakpoint at "foo" is long gone from the breakpoint table. 2669 If we vforked, then we don't need to unpatch here, since both 2670 parent and child are sharing the same memory pages; we'll 2671 need to unpatch at follow/detach time instead to be certain 2672 that new breakpoints added between catchpoint hit time and 2673 vfork follow are detached. */ 2674 if (ecs->ws.kind != TARGET_WAITKIND_VFORKED) 2675 { 2676 int child_pid = ptid_get_pid (ecs->ws.value.related_pid); 2677 2678 /* This won't actually modify the breakpoint list, but will 2679 physically remove the breakpoints from the child. */ 2680 detach_breakpoints (child_pid); 2681 } 2682 2683 /* In case the event is caught by a catchpoint, remember that 2684 the event is to be followed at the next resume of the thread, 2685 and not immediately. */ 2686 ecs->event_thread->pending_follow = ecs->ws; 2687 2688 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid)); 2689 2690 ecs->event_thread->stop_bpstat = bpstat_stop_status (stop_pc, ecs->ptid); 2691 2692 ecs->random_signal = !bpstat_explains_signal (ecs->event_thread->stop_bpstat); 2693 2694 /* If no catchpoint triggered for this, then keep going. */ 2695 if (ecs->random_signal) 2696 { 2697 int should_resume; 2698 2699 ecs->event_thread->stop_signal = TARGET_SIGNAL_0; 2700 2701 should_resume = follow_fork (); 2702 2703 ecs->event_thread = inferior_thread (); 2704 ecs->ptid = inferior_ptid; 2705 2706 if (should_resume) 2707 keep_going (ecs); 2708 else 2709 stop_stepping (ecs); 2710 return; 2711 } 2712 ecs->event_thread->stop_signal = TARGET_SIGNAL_TRAP; 2713 goto process_event_stop_test; 2714 2715 case TARGET_WAITKIND_EXECD: 2716 if (debug_infrun) 2717 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_EXECD\n"); 2718 2719 if (!ptid_equal (ecs->ptid, inferior_ptid)) 2720 { 2721 context_switch (ecs->ptid); 2722 reinit_frame_cache (); 2723 } 2724 2725 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid)); 2726 2727 /* This causes the eventpoints and symbol table to be reset. 2728 Must do this now, before trying to determine whether to 2729 stop. */ 2730 follow_exec (inferior_ptid, ecs->ws.value.execd_pathname); 2731 2732 ecs->event_thread->stop_bpstat = bpstat_stop_status (stop_pc, ecs->ptid); 2733 ecs->random_signal = !bpstat_explains_signal (ecs->event_thread->stop_bpstat); 2734 2735 /* Note that this may be referenced from inside 2736 bpstat_stop_status above, through inferior_has_execd. */ 2737 xfree (ecs->ws.value.execd_pathname); 2738 ecs->ws.value.execd_pathname = NULL; 2739 2740 /* If no catchpoint triggered for this, then keep going. */ 2741 if (ecs->random_signal) 2742 { 2743 ecs->event_thread->stop_signal = TARGET_SIGNAL_0; 2744 keep_going (ecs); 2745 return; 2746 } 2747 ecs->event_thread->stop_signal = TARGET_SIGNAL_TRAP; 2748 goto process_event_stop_test; 2749 2750 /* Be careful not to try to gather much state about a thread 2751 that's in a syscall. It's frequently a losing proposition. */ 2752 case TARGET_WAITKIND_SYSCALL_ENTRY: 2753 if (debug_infrun) 2754 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n"); 2755 /* Getting the current syscall number */ 2756 if (deal_with_syscall_event (ecs) != 0) 2757 return; 2758 goto process_event_stop_test; 2759 break; 2760 2761 /* Before examining the threads further, step this thread to 2762 get it entirely out of the syscall. (We get notice of the 2763 event when the thread is just on the verge of exiting a 2764 syscall. Stepping one instruction seems to get it back 2765 into user code.) */ 2766 case TARGET_WAITKIND_SYSCALL_RETURN: 2767 if (debug_infrun) 2768 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SYSCALL_RETURN\n"); 2769 if (deal_with_syscall_event (ecs) != 0) 2770 return; 2771 goto process_event_stop_test; 2772 break; 2773 2774 case TARGET_WAITKIND_STOPPED: 2775 if (debug_infrun) 2776 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_STOPPED\n"); 2777 ecs->event_thread->stop_signal = ecs->ws.value.sig; 2778 break; 2779 2780 case TARGET_WAITKIND_NO_HISTORY: 2781 /* Reverse execution: target ran out of history info. */ 2782 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid)); 2783 print_stop_reason (NO_HISTORY, 0); 2784 stop_stepping (ecs); 2785 return; 2786 2787 /* We had an event in the inferior, but we are not interested 2788 in handling it at this level. The lower layers have already 2789 done what needs to be done, if anything. 2790 2791 One of the possible circumstances for this is when the 2792 inferior produces output for the console. The inferior has 2793 not stopped, and we are ignoring the event. Another possible 2794 circumstance is any event which the lower level knows will be 2795 reported multiple times without an intervening resume. */ 2796 case TARGET_WAITKIND_IGNORE: 2797 if (debug_infrun) 2798 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_IGNORE\n"); 2799 prepare_to_wait (ecs); 2800 return; 2801 } 2802 2803 if (ecs->new_thread_event) 2804 { 2805 if (non_stop) 2806 /* Non-stop assumes that the target handles adding new threads 2807 to the thread list. */ 2808 internal_error (__FILE__, __LINE__, "\ 2809 targets should add new threads to the thread list themselves in non-stop mode."); 2810 2811 /* We may want to consider not doing a resume here in order to 2812 give the user a chance to play with the new thread. It might 2813 be good to make that a user-settable option. */ 2814 2815 /* At this point, all threads are stopped (happens automatically 2816 in either the OS or the native code). Therefore we need to 2817 continue all threads in order to make progress. */ 2818 2819 if (!ptid_equal (ecs->ptid, inferior_ptid)) 2820 context_switch (ecs->ptid); 2821 target_resume (RESUME_ALL, 0, TARGET_SIGNAL_0); 2822 prepare_to_wait (ecs); 2823 return; 2824 } 2825 2826 if (ecs->ws.kind == TARGET_WAITKIND_STOPPED) 2827 { 2828 /* Do we need to clean up the state of a thread that has 2829 completed a displaced single-step? (Doing so usually affects 2830 the PC, so do it here, before we set stop_pc.) */ 2831 displaced_step_fixup (ecs->ptid, ecs->event_thread->stop_signal); 2832 2833 /* If we either finished a single-step or hit a breakpoint, but 2834 the user wanted this thread to be stopped, pretend we got a 2835 SIG0 (generic unsignaled stop). */ 2836 2837 if (ecs->event_thread->stop_requested 2838 && ecs->event_thread->stop_signal == TARGET_SIGNAL_TRAP) 2839 ecs->event_thread->stop_signal = TARGET_SIGNAL_0; 2840 } 2841 2842 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid)); 2843 2844 if (debug_infrun) 2845 { 2846 struct regcache *regcache = get_thread_regcache (ecs->ptid); 2847 struct gdbarch *gdbarch = get_regcache_arch (regcache); 2848 2849 fprintf_unfiltered (gdb_stdlog, "infrun: stop_pc = %s\n", 2850 paddress (gdbarch, stop_pc)); 2851 if (target_stopped_by_watchpoint ()) 2852 { 2853 CORE_ADDR addr; 2854 fprintf_unfiltered (gdb_stdlog, "infrun: stopped by watchpoint\n"); 2855 2856 if (target_stopped_data_address (¤t_target, &addr)) 2857 fprintf_unfiltered (gdb_stdlog, 2858 "infrun: stopped data address = %s\n", 2859 paddress (gdbarch, addr)); 2860 else 2861 fprintf_unfiltered (gdb_stdlog, 2862 "infrun: (no data address available)\n"); 2863 } 2864 } 2865 2866 if (stepping_past_singlestep_breakpoint) 2867 { 2868 gdb_assert (singlestep_breakpoints_inserted_p); 2869 gdb_assert (ptid_equal (singlestep_ptid, ecs->ptid)); 2870 gdb_assert (!ptid_equal (singlestep_ptid, saved_singlestep_ptid)); 2871 2872 stepping_past_singlestep_breakpoint = 0; 2873 2874 /* We've either finished single-stepping past the single-step 2875 breakpoint, or stopped for some other reason. It would be nice if 2876 we could tell, but we can't reliably. */ 2877 if (ecs->event_thread->stop_signal == TARGET_SIGNAL_TRAP) 2878 { 2879 if (debug_infrun) 2880 fprintf_unfiltered (gdb_stdlog, "infrun: stepping_past_singlestep_breakpoint\n"); 2881 /* Pull the single step breakpoints out of the target. */ 2882 remove_single_step_breakpoints (); 2883 singlestep_breakpoints_inserted_p = 0; 2884 2885 ecs->random_signal = 0; 2886 ecs->event_thread->trap_expected = 0; 2887 2888 context_switch (saved_singlestep_ptid); 2889 if (deprecated_context_hook) 2890 deprecated_context_hook (pid_to_thread_id (ecs->ptid)); 2891 2892 resume (1, TARGET_SIGNAL_0); 2893 prepare_to_wait (ecs); 2894 return; 2895 } 2896 } 2897 2898 if (!ptid_equal (deferred_step_ptid, null_ptid)) 2899 { 2900 /* In non-stop mode, there's never a deferred_step_ptid set. */ 2901 gdb_assert (!non_stop); 2902 2903 /* If we stopped for some other reason than single-stepping, ignore 2904 the fact that we were supposed to switch back. */ 2905 if (ecs->event_thread->stop_signal == TARGET_SIGNAL_TRAP) 2906 { 2907 if (debug_infrun) 2908 fprintf_unfiltered (gdb_stdlog, 2909 "infrun: handling deferred step\n"); 2910 2911 /* Pull the single step breakpoints out of the target. */ 2912 if (singlestep_breakpoints_inserted_p) 2913 { 2914 remove_single_step_breakpoints (); 2915 singlestep_breakpoints_inserted_p = 0; 2916 } 2917 2918 /* Note: We do not call context_switch at this point, as the 2919 context is already set up for stepping the original thread. */ 2920 switch_to_thread (deferred_step_ptid); 2921 deferred_step_ptid = null_ptid; 2922 /* Suppress spurious "Switching to ..." message. */ 2923 previous_inferior_ptid = inferior_ptid; 2924 2925 resume (1, TARGET_SIGNAL_0); 2926 prepare_to_wait (ecs); 2927 return; 2928 } 2929 2930 deferred_step_ptid = null_ptid; 2931 } 2932 2933 /* See if a thread hit a thread-specific breakpoint that was meant for 2934 another thread. If so, then step that thread past the breakpoint, 2935 and continue it. */ 2936 2937 if (ecs->event_thread->stop_signal == TARGET_SIGNAL_TRAP) 2938 { 2939 int thread_hop_needed = 0; 2940 2941 /* Check if a regular breakpoint has been hit before checking 2942 for a potential single step breakpoint. Otherwise, GDB will 2943 not see this breakpoint hit when stepping onto breakpoints. */ 2944 if (regular_breakpoint_inserted_here_p (stop_pc)) 2945 { 2946 ecs->random_signal = 0; 2947 if (!breakpoint_thread_match (stop_pc, ecs->ptid)) 2948 thread_hop_needed = 1; 2949 } 2950 else if (singlestep_breakpoints_inserted_p) 2951 { 2952 /* We have not context switched yet, so this should be true 2953 no matter which thread hit the singlestep breakpoint. */ 2954 gdb_assert (ptid_equal (inferior_ptid, singlestep_ptid)); 2955 if (debug_infrun) 2956 fprintf_unfiltered (gdb_stdlog, "infrun: software single step " 2957 "trap for %s\n", 2958 target_pid_to_str (ecs->ptid)); 2959 2960 ecs->random_signal = 0; 2961 /* The call to in_thread_list is necessary because PTIDs sometimes 2962 change when we go from single-threaded to multi-threaded. If 2963 the singlestep_ptid is still in the list, assume that it is 2964 really different from ecs->ptid. */ 2965 if (!ptid_equal (singlestep_ptid, ecs->ptid) 2966 && in_thread_list (singlestep_ptid)) 2967 { 2968 /* If the PC of the thread we were trying to single-step 2969 has changed, discard this event (which we were going 2970 to ignore anyway), and pretend we saw that thread 2971 trap. This prevents us continuously moving the 2972 single-step breakpoint forward, one instruction at a 2973 time. If the PC has changed, then the thread we were 2974 trying to single-step has trapped or been signalled, 2975 but the event has not been reported to GDB yet. 2976 2977 There might be some cases where this loses signal 2978 information, if a signal has arrived at exactly the 2979 same time that the PC changed, but this is the best 2980 we can do with the information available. Perhaps we 2981 should arrange to report all events for all threads 2982 when they stop, or to re-poll the remote looking for 2983 this particular thread (i.e. temporarily enable 2984 schedlock). */ 2985 2986 CORE_ADDR new_singlestep_pc 2987 = regcache_read_pc (get_thread_regcache (singlestep_ptid)); 2988 2989 if (new_singlestep_pc != singlestep_pc) 2990 { 2991 enum target_signal stop_signal; 2992 2993 if (debug_infrun) 2994 fprintf_unfiltered (gdb_stdlog, "infrun: unexpected thread," 2995 " but expected thread advanced also\n"); 2996 2997 /* The current context still belongs to 2998 singlestep_ptid. Don't swap here, since that's 2999 the context we want to use. Just fudge our 3000 state and continue. */ 3001 stop_signal = ecs->event_thread->stop_signal; 3002 ecs->event_thread->stop_signal = TARGET_SIGNAL_0; 3003 ecs->ptid = singlestep_ptid; 3004 ecs->event_thread = find_thread_ptid (ecs->ptid); 3005 ecs->event_thread->stop_signal = stop_signal; 3006 stop_pc = new_singlestep_pc; 3007 } 3008 else 3009 { 3010 if (debug_infrun) 3011 fprintf_unfiltered (gdb_stdlog, 3012 "infrun: unexpected thread\n"); 3013 3014 thread_hop_needed = 1; 3015 stepping_past_singlestep_breakpoint = 1; 3016 saved_singlestep_ptid = singlestep_ptid; 3017 } 3018 } 3019 } 3020 3021 if (thread_hop_needed) 3022 { 3023 struct regcache *thread_regcache; 3024 int remove_status = 0; 3025 3026 if (debug_infrun) 3027 fprintf_unfiltered (gdb_stdlog, "infrun: thread_hop_needed\n"); 3028 3029 /* Switch context before touching inferior memory, the 3030 previous thread may have exited. */ 3031 if (!ptid_equal (inferior_ptid, ecs->ptid)) 3032 context_switch (ecs->ptid); 3033 3034 /* Saw a breakpoint, but it was hit by the wrong thread. 3035 Just continue. */ 3036 3037 if (singlestep_breakpoints_inserted_p) 3038 { 3039 /* Pull the single step breakpoints out of the target. */ 3040 remove_single_step_breakpoints (); 3041 singlestep_breakpoints_inserted_p = 0; 3042 } 3043 3044 /* If the arch can displace step, don't remove the 3045 breakpoints. */ 3046 thread_regcache = get_thread_regcache (ecs->ptid); 3047 if (!use_displaced_stepping (get_regcache_arch (thread_regcache))) 3048 remove_status = remove_breakpoints (); 3049 3050 /* Did we fail to remove breakpoints? If so, try 3051 to set the PC past the bp. (There's at least 3052 one situation in which we can fail to remove 3053 the bp's: On HP-UX's that use ttrace, we can't 3054 change the address space of a vforking child 3055 process until the child exits (well, okay, not 3056 then either :-) or execs. */ 3057 if (remove_status != 0) 3058 error (_("Cannot step over breakpoint hit in wrong thread")); 3059 else 3060 { /* Single step */ 3061 if (!non_stop) 3062 { 3063 /* Only need to require the next event from this 3064 thread in all-stop mode. */ 3065 waiton_ptid = ecs->ptid; 3066 infwait_state = infwait_thread_hop_state; 3067 } 3068 3069 ecs->event_thread->stepping_over_breakpoint = 1; 3070 keep_going (ecs); 3071 return; 3072 } 3073 } 3074 else if (singlestep_breakpoints_inserted_p) 3075 { 3076 sw_single_step_trap_p = 1; 3077 ecs->random_signal = 0; 3078 } 3079 } 3080 else 3081 ecs->random_signal = 1; 3082 3083 /* See if something interesting happened to the non-current thread. If 3084 so, then switch to that thread. */ 3085 if (!ptid_equal (ecs->ptid, inferior_ptid)) 3086 { 3087 if (debug_infrun) 3088 fprintf_unfiltered (gdb_stdlog, "infrun: context switch\n"); 3089 3090 context_switch (ecs->ptid); 3091 3092 if (deprecated_context_hook) 3093 deprecated_context_hook (pid_to_thread_id (ecs->ptid)); 3094 } 3095 3096 /* At this point, get hold of the now-current thread's frame. */ 3097 frame = get_current_frame (); 3098 gdbarch = get_frame_arch (frame); 3099 3100 if (singlestep_breakpoints_inserted_p) 3101 { 3102 /* Pull the single step breakpoints out of the target. */ 3103 remove_single_step_breakpoints (); 3104 singlestep_breakpoints_inserted_p = 0; 3105 } 3106 3107 if (stepped_after_stopped_by_watchpoint) 3108 stopped_by_watchpoint = 0; 3109 else 3110 stopped_by_watchpoint = watchpoints_triggered (&ecs->ws); 3111 3112 /* If necessary, step over this watchpoint. We'll be back to display 3113 it in a moment. */ 3114 if (stopped_by_watchpoint 3115 && (target_have_steppable_watchpoint 3116 || gdbarch_have_nonsteppable_watchpoint (gdbarch))) 3117 { 3118 /* At this point, we are stopped at an instruction which has 3119 attempted to write to a piece of memory under control of 3120 a watchpoint. The instruction hasn't actually executed 3121 yet. If we were to evaluate the watchpoint expression 3122 now, we would get the old value, and therefore no change 3123 would seem to have occurred. 3124 3125 In order to make watchpoints work `right', we really need 3126 to complete the memory write, and then evaluate the 3127 watchpoint expression. We do this by single-stepping the 3128 target. 3129 3130 It may not be necessary to disable the watchpoint to stop over 3131 it. For example, the PA can (with some kernel cooperation) 3132 single step over a watchpoint without disabling the watchpoint. 3133 3134 It is far more common to need to disable a watchpoint to step 3135 the inferior over it. If we have non-steppable watchpoints, 3136 we must disable the current watchpoint; it's simplest to 3137 disable all watchpoints and breakpoints. */ 3138 int hw_step = 1; 3139 3140 if (!target_have_steppable_watchpoint) 3141 remove_breakpoints (); 3142 /* Single step */ 3143 hw_step = maybe_software_singlestep (gdbarch, stop_pc); 3144 target_resume (ecs->ptid, hw_step, TARGET_SIGNAL_0); 3145 waiton_ptid = ecs->ptid; 3146 if (target_have_steppable_watchpoint) 3147 infwait_state = infwait_step_watch_state; 3148 else 3149 infwait_state = infwait_nonstep_watch_state; 3150 prepare_to_wait (ecs); 3151 return; 3152 } 3153 3154 ecs->stop_func_start = 0; 3155 ecs->stop_func_end = 0; 3156 ecs->stop_func_name = 0; 3157 /* Don't care about return value; stop_func_start and stop_func_name 3158 will both be 0 if it doesn't work. */ 3159 find_pc_partial_function (stop_pc, &ecs->stop_func_name, 3160 &ecs->stop_func_start, &ecs->stop_func_end); 3161 ecs->stop_func_start 3162 += gdbarch_deprecated_function_start_offset (gdbarch); 3163 ecs->event_thread->stepping_over_breakpoint = 0; 3164 bpstat_clear (&ecs->event_thread->stop_bpstat); 3165 ecs->event_thread->stop_step = 0; 3166 stop_print_frame = 1; 3167 ecs->random_signal = 0; 3168 stopped_by_random_signal = 0; 3169 3170 /* Hide inlined functions starting here, unless we just performed stepi or 3171 nexti. After stepi and nexti, always show the innermost frame (not any 3172 inline function call sites). */ 3173 if (ecs->event_thread->step_range_end != 1) 3174 skip_inline_frames (ecs->ptid); 3175 3176 if (ecs->event_thread->stop_signal == TARGET_SIGNAL_TRAP 3177 && ecs->event_thread->trap_expected 3178 && gdbarch_single_step_through_delay_p (gdbarch) 3179 && currently_stepping (ecs->event_thread)) 3180 { 3181 /* We're trying to step off a breakpoint. Turns out that we're 3182 also on an instruction that needs to be stepped multiple 3183 times before it's been fully executing. E.g., architectures 3184 with a delay slot. It needs to be stepped twice, once for 3185 the instruction and once for the delay slot. */ 3186 int step_through_delay 3187 = gdbarch_single_step_through_delay (gdbarch, frame); 3188 if (debug_infrun && step_through_delay) 3189 fprintf_unfiltered (gdb_stdlog, "infrun: step through delay\n"); 3190 if (ecs->event_thread->step_range_end == 0 && step_through_delay) 3191 { 3192 /* The user issued a continue when stopped at a breakpoint. 3193 Set up for another trap and get out of here. */ 3194 ecs->event_thread->stepping_over_breakpoint = 1; 3195 keep_going (ecs); 3196 return; 3197 } 3198 else if (step_through_delay) 3199 { 3200 /* The user issued a step when stopped at a breakpoint. 3201 Maybe we should stop, maybe we should not - the delay 3202 slot *might* correspond to a line of source. In any 3203 case, don't decide that here, just set 3204 ecs->stepping_over_breakpoint, making sure we 3205 single-step again before breakpoints are re-inserted. */ 3206 ecs->event_thread->stepping_over_breakpoint = 1; 3207 } 3208 } 3209 3210 /* Look at the cause of the stop, and decide what to do. 3211 The alternatives are: 3212 1) stop_stepping and return; to really stop and return to the debugger, 3213 2) keep_going and return to start up again 3214 (set ecs->event_thread->stepping_over_breakpoint to 1 to single step once) 3215 3) set ecs->random_signal to 1, and the decision between 1 and 2 3216 will be made according to the signal handling tables. */ 3217 3218 /* First, distinguish signals caused by the debugger from signals 3219 that have to do with the program's own actions. Note that 3220 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending 3221 on the operating system version. Here we detect when a SIGILL or 3222 SIGEMT is really a breakpoint and change it to SIGTRAP. We do 3223 something similar for SIGSEGV, since a SIGSEGV will be generated 3224 when we're trying to execute a breakpoint instruction on a 3225 non-executable stack. This happens for call dummy breakpoints 3226 for architectures like SPARC that place call dummies on the 3227 stack. 3228 3229 If we're doing a displaced step past a breakpoint, then the 3230 breakpoint is always inserted at the original instruction; 3231 non-standard signals can't be explained by the breakpoint. */ 3232 if (ecs->event_thread->stop_signal == TARGET_SIGNAL_TRAP 3233 || (! ecs->event_thread->trap_expected 3234 && breakpoint_inserted_here_p (stop_pc) 3235 && (ecs->event_thread->stop_signal == TARGET_SIGNAL_ILL 3236 || ecs->event_thread->stop_signal == TARGET_SIGNAL_SEGV 3237 || ecs->event_thread->stop_signal == TARGET_SIGNAL_EMT)) 3238 || stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_NO_SIGSTOP 3239 || stop_soon == STOP_QUIETLY_REMOTE) 3240 { 3241 if (ecs->event_thread->stop_signal == TARGET_SIGNAL_TRAP && stop_after_trap) 3242 { 3243 if (debug_infrun) 3244 fprintf_unfiltered (gdb_stdlog, "infrun: stopped\n"); 3245 stop_print_frame = 0; 3246 stop_stepping (ecs); 3247 return; 3248 } 3249 3250 /* This is originated from start_remote(), start_inferior() and 3251 shared libraries hook functions. */ 3252 if (stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_REMOTE) 3253 { 3254 if (debug_infrun) 3255 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n"); 3256 stop_stepping (ecs); 3257 return; 3258 } 3259 3260 /* This originates from attach_command(). We need to overwrite 3261 the stop_signal here, because some kernels don't ignore a 3262 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call. 3263 See more comments in inferior.h. On the other hand, if we 3264 get a non-SIGSTOP, report it to the user - assume the backend 3265 will handle the SIGSTOP if it should show up later. 3266 3267 Also consider that the attach is complete when we see a 3268 SIGTRAP. Some systems (e.g. Windows), and stubs supporting 3269 target extended-remote report it instead of a SIGSTOP 3270 (e.g. gdbserver). We already rely on SIGTRAP being our 3271 signal, so this is no exception. 3272 3273 Also consider that the attach is complete when we see a 3274 TARGET_SIGNAL_0. In non-stop mode, GDB will explicitly tell 3275 the target to stop all threads of the inferior, in case the 3276 low level attach operation doesn't stop them implicitly. If 3277 they weren't stopped implicitly, then the stub will report a 3278 TARGET_SIGNAL_0, meaning: stopped for no particular reason 3279 other than GDB's request. */ 3280 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP 3281 && (ecs->event_thread->stop_signal == TARGET_SIGNAL_STOP 3282 || ecs->event_thread->stop_signal == TARGET_SIGNAL_TRAP 3283 || ecs->event_thread->stop_signal == TARGET_SIGNAL_0)) 3284 { 3285 stop_stepping (ecs); 3286 ecs->event_thread->stop_signal = TARGET_SIGNAL_0; 3287 return; 3288 } 3289 3290 /* See if there is a breakpoint at the current PC. */ 3291 ecs->event_thread->stop_bpstat = bpstat_stop_status (stop_pc, ecs->ptid); 3292 3293 /* Following in case break condition called a 3294 function. */ 3295 stop_print_frame = 1; 3296 3297 /* NOTE: cagney/2003-03-29: These two checks for a random signal 3298 at one stage in the past included checks for an inferior 3299 function call's call dummy's return breakpoint. The original 3300 comment, that went with the test, read: 3301 3302 ``End of a stack dummy. Some systems (e.g. Sony news) give 3303 another signal besides SIGTRAP, so check here as well as 3304 above.'' 3305 3306 If someone ever tries to get call dummys on a 3307 non-executable stack to work (where the target would stop 3308 with something like a SIGSEGV), then those tests might need 3309 to be re-instated. Given, however, that the tests were only 3310 enabled when momentary breakpoints were not being used, I 3311 suspect that it won't be the case. 3312 3313 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to 3314 be necessary for call dummies on a non-executable stack on 3315 SPARC. */ 3316 3317 if (ecs->event_thread->stop_signal == TARGET_SIGNAL_TRAP) 3318 ecs->random_signal 3319 = !(bpstat_explains_signal (ecs->event_thread->stop_bpstat) 3320 || ecs->event_thread->trap_expected 3321 || (ecs->event_thread->step_range_end 3322 && ecs->event_thread->step_resume_breakpoint == NULL)); 3323 else 3324 { 3325 ecs->random_signal = !bpstat_explains_signal (ecs->event_thread->stop_bpstat); 3326 if (!ecs->random_signal) 3327 ecs->event_thread->stop_signal = TARGET_SIGNAL_TRAP; 3328 } 3329 } 3330 3331 /* When we reach this point, we've pretty much decided 3332 that the reason for stopping must've been a random 3333 (unexpected) signal. */ 3334 3335 else 3336 ecs->random_signal = 1; 3337 3338 process_event_stop_test: 3339 3340 /* Re-fetch current thread's frame in case we did a 3341 "goto process_event_stop_test" above. */ 3342 frame = get_current_frame (); 3343 gdbarch = get_frame_arch (frame); 3344 3345 /* For the program's own signals, act according to 3346 the signal handling tables. */ 3347 3348 if (ecs->random_signal) 3349 { 3350 /* Signal not for debugging purposes. */ 3351 int printed = 0; 3352 3353 if (debug_infrun) 3354 fprintf_unfiltered (gdb_stdlog, "infrun: random signal %d\n", 3355 ecs->event_thread->stop_signal); 3356 3357 stopped_by_random_signal = 1; 3358 3359 if (signal_print[ecs->event_thread->stop_signal]) 3360 { 3361 printed = 1; 3362 target_terminal_ours_for_output (); 3363 print_stop_reason (SIGNAL_RECEIVED, ecs->event_thread->stop_signal); 3364 } 3365 /* Always stop on signals if we're either just gaining control 3366 of the program, or the user explicitly requested this thread 3367 to remain stopped. */ 3368 if (stop_soon != NO_STOP_QUIETLY 3369 || ecs->event_thread->stop_requested 3370 || signal_stop_state (ecs->event_thread->stop_signal)) 3371 { 3372 stop_stepping (ecs); 3373 return; 3374 } 3375 /* If not going to stop, give terminal back 3376 if we took it away. */ 3377 else if (printed) 3378 target_terminal_inferior (); 3379 3380 /* Clear the signal if it should not be passed. */ 3381 if (signal_program[ecs->event_thread->stop_signal] == 0) 3382 ecs->event_thread->stop_signal = TARGET_SIGNAL_0; 3383 3384 if (ecs->event_thread->prev_pc == stop_pc 3385 && ecs->event_thread->trap_expected 3386 && ecs->event_thread->step_resume_breakpoint == NULL) 3387 { 3388 /* We were just starting a new sequence, attempting to 3389 single-step off of a breakpoint and expecting a SIGTRAP. 3390 Instead this signal arrives. This signal will take us out 3391 of the stepping range so GDB needs to remember to, when 3392 the signal handler returns, resume stepping off that 3393 breakpoint. */ 3394 /* To simplify things, "continue" is forced to use the same 3395 code paths as single-step - set a breakpoint at the 3396 signal return address and then, once hit, step off that 3397 breakpoint. */ 3398 if (debug_infrun) 3399 fprintf_unfiltered (gdb_stdlog, 3400 "infrun: signal arrived while stepping over " 3401 "breakpoint\n"); 3402 3403 insert_step_resume_breakpoint_at_frame (frame); 3404 ecs->event_thread->step_after_step_resume_breakpoint = 1; 3405 keep_going (ecs); 3406 return; 3407 } 3408 3409 if (ecs->event_thread->step_range_end != 0 3410 && ecs->event_thread->stop_signal != TARGET_SIGNAL_0 3411 && (ecs->event_thread->step_range_start <= stop_pc 3412 && stop_pc < ecs->event_thread->step_range_end) 3413 && frame_id_eq (get_stack_frame_id (frame), 3414 ecs->event_thread->step_stack_frame_id) 3415 && ecs->event_thread->step_resume_breakpoint == NULL) 3416 { 3417 /* The inferior is about to take a signal that will take it 3418 out of the single step range. Set a breakpoint at the 3419 current PC (which is presumably where the signal handler 3420 will eventually return) and then allow the inferior to 3421 run free. 3422 3423 Note that this is only needed for a signal delivered 3424 while in the single-step range. Nested signals aren't a 3425 problem as they eventually all return. */ 3426 if (debug_infrun) 3427 fprintf_unfiltered (gdb_stdlog, 3428 "infrun: signal may take us out of " 3429 "single-step range\n"); 3430 3431 insert_step_resume_breakpoint_at_frame (frame); 3432 keep_going (ecs); 3433 return; 3434 } 3435 3436 /* Note: step_resume_breakpoint may be non-NULL. This occures 3437 when either there's a nested signal, or when there's a 3438 pending signal enabled just as the signal handler returns 3439 (leaving the inferior at the step-resume-breakpoint without 3440 actually executing it). Either way continue until the 3441 breakpoint is really hit. */ 3442 keep_going (ecs); 3443 return; 3444 } 3445 3446 /* Handle cases caused by hitting a breakpoint. */ 3447 { 3448 CORE_ADDR jmp_buf_pc; 3449 struct bpstat_what what; 3450 3451 what = bpstat_what (ecs->event_thread->stop_bpstat); 3452 3453 if (what.call_dummy) 3454 { 3455 stop_stack_dummy = 1; 3456 } 3457 3458 switch (what.main_action) 3459 { 3460 case BPSTAT_WHAT_SET_LONGJMP_RESUME: 3461 /* If we hit the breakpoint at longjmp while stepping, we 3462 install a momentary breakpoint at the target of the 3463 jmp_buf. */ 3464 3465 if (debug_infrun) 3466 fprintf_unfiltered (gdb_stdlog, 3467 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n"); 3468 3469 ecs->event_thread->stepping_over_breakpoint = 1; 3470 3471 if (!gdbarch_get_longjmp_target_p (gdbarch) 3472 || !gdbarch_get_longjmp_target (gdbarch, frame, &jmp_buf_pc)) 3473 { 3474 if (debug_infrun) 3475 fprintf_unfiltered (gdb_stdlog, "\ 3476 infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME (!gdbarch_get_longjmp_target)\n"); 3477 keep_going (ecs); 3478 return; 3479 } 3480 3481 /* We're going to replace the current step-resume breakpoint 3482 with a longjmp-resume breakpoint. */ 3483 delete_step_resume_breakpoint (ecs->event_thread); 3484 3485 /* Insert a breakpoint at resume address. */ 3486 insert_longjmp_resume_breakpoint (gdbarch, jmp_buf_pc); 3487 3488 keep_going (ecs); 3489 return; 3490 3491 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME: 3492 if (debug_infrun) 3493 fprintf_unfiltered (gdb_stdlog, 3494 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n"); 3495 3496 gdb_assert (ecs->event_thread->step_resume_breakpoint != NULL); 3497 delete_step_resume_breakpoint (ecs->event_thread); 3498 3499 ecs->event_thread->stop_step = 1; 3500 print_stop_reason (END_STEPPING_RANGE, 0); 3501 stop_stepping (ecs); 3502 return; 3503 3504 case BPSTAT_WHAT_SINGLE: 3505 if (debug_infrun) 3506 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_SINGLE\n"); 3507 ecs->event_thread->stepping_over_breakpoint = 1; 3508 /* Still need to check other stuff, at least the case 3509 where we are stepping and step out of the right range. */ 3510 break; 3511 3512 case BPSTAT_WHAT_STOP_NOISY: 3513 if (debug_infrun) 3514 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_NOISY\n"); 3515 stop_print_frame = 1; 3516 3517 /* We are about to nuke the step_resume_breakpointt via the 3518 cleanup chain, so no need to worry about it here. */ 3519 3520 stop_stepping (ecs); 3521 return; 3522 3523 case BPSTAT_WHAT_STOP_SILENT: 3524 if (debug_infrun) 3525 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_SILENT\n"); 3526 stop_print_frame = 0; 3527 3528 /* We are about to nuke the step_resume_breakpoin via the 3529 cleanup chain, so no need to worry about it here. */ 3530 3531 stop_stepping (ecs); 3532 return; 3533 3534 case BPSTAT_WHAT_STEP_RESUME: 3535 if (debug_infrun) 3536 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STEP_RESUME\n"); 3537 3538 delete_step_resume_breakpoint (ecs->event_thread); 3539 if (ecs->event_thread->step_after_step_resume_breakpoint) 3540 { 3541 /* Back when the step-resume breakpoint was inserted, we 3542 were trying to single-step off a breakpoint. Go back 3543 to doing that. */ 3544 ecs->event_thread->step_after_step_resume_breakpoint = 0; 3545 ecs->event_thread->stepping_over_breakpoint = 1; 3546 keep_going (ecs); 3547 return; 3548 } 3549 if (stop_pc == ecs->stop_func_start 3550 && execution_direction == EXEC_REVERSE) 3551 { 3552 /* We are stepping over a function call in reverse, and 3553 just hit the step-resume breakpoint at the start 3554 address of the function. Go back to single-stepping, 3555 which should take us back to the function call. */ 3556 ecs->event_thread->stepping_over_breakpoint = 1; 3557 keep_going (ecs); 3558 return; 3559 } 3560 break; 3561 3562 case BPSTAT_WHAT_CHECK_SHLIBS: 3563 { 3564 if (debug_infrun) 3565 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_CHECK_SHLIBS\n"); 3566 3567 /* Check for any newly added shared libraries if we're 3568 supposed to be adding them automatically. Switch 3569 terminal for any messages produced by 3570 breakpoint_re_set. */ 3571 target_terminal_ours_for_output (); 3572 /* NOTE: cagney/2003-11-25: Make certain that the target 3573 stack's section table is kept up-to-date. Architectures, 3574 (e.g., PPC64), use the section table to perform 3575 operations such as address => section name and hence 3576 require the table to contain all sections (including 3577 those found in shared libraries). */ 3578 #ifdef SOLIB_ADD 3579 SOLIB_ADD (NULL, 0, ¤t_target, auto_solib_add); 3580 #else 3581 solib_add (NULL, 0, ¤t_target, auto_solib_add); 3582 #endif 3583 target_terminal_inferior (); 3584 3585 /* If requested, stop when the dynamic linker notifies 3586 gdb of events. This allows the user to get control 3587 and place breakpoints in initializer routines for 3588 dynamically loaded objects (among other things). */ 3589 if (stop_on_solib_events || stop_stack_dummy) 3590 { 3591 stop_stepping (ecs); 3592 return; 3593 } 3594 else 3595 { 3596 /* We want to step over this breakpoint, then keep going. */ 3597 ecs->event_thread->stepping_over_breakpoint = 1; 3598 break; 3599 } 3600 } 3601 break; 3602 3603 case BPSTAT_WHAT_CHECK_JIT: 3604 if (debug_infrun) 3605 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_CHECK_JIT\n"); 3606 3607 /* Switch terminal for any messages produced by breakpoint_re_set. */ 3608 target_terminal_ours_for_output (); 3609 3610 jit_event_handler (gdbarch); 3611 3612 target_terminal_inferior (); 3613 3614 /* We want to step over this breakpoint, then keep going. */ 3615 ecs->event_thread->stepping_over_breakpoint = 1; 3616 3617 break; 3618 3619 case BPSTAT_WHAT_LAST: 3620 /* Not a real code, but listed here to shut up gcc -Wall. */ 3621 3622 case BPSTAT_WHAT_KEEP_CHECKING: 3623 break; 3624 } 3625 } 3626 3627 /* We come here if we hit a breakpoint but should not 3628 stop for it. Possibly we also were stepping 3629 and should stop for that. So fall through and 3630 test for stepping. But, if not stepping, 3631 do not stop. */ 3632 3633 /* In all-stop mode, if we're currently stepping but have stopped in 3634 some other thread, we need to switch back to the stepped thread. */ 3635 if (!non_stop) 3636 { 3637 struct thread_info *tp; 3638 tp = iterate_over_threads (currently_stepping_or_nexting_callback, 3639 ecs->event_thread); 3640 if (tp) 3641 { 3642 /* However, if the current thread is blocked on some internal 3643 breakpoint, and we simply need to step over that breakpoint 3644 to get it going again, do that first. */ 3645 if ((ecs->event_thread->trap_expected 3646 && ecs->event_thread->stop_signal != TARGET_SIGNAL_TRAP) 3647 || ecs->event_thread->stepping_over_breakpoint) 3648 { 3649 keep_going (ecs); 3650 return; 3651 } 3652 3653 /* If the stepping thread exited, then don't try to switch 3654 back and resume it, which could fail in several different 3655 ways depending on the target. Instead, just keep going. 3656 3657 We can find a stepping dead thread in the thread list in 3658 two cases: 3659 3660 - The target supports thread exit events, and when the 3661 target tries to delete the thread from the thread list, 3662 inferior_ptid pointed at the exiting thread. In such 3663 case, calling delete_thread does not really remove the 3664 thread from the list; instead, the thread is left listed, 3665 with 'exited' state. 3666 3667 - The target's debug interface does not support thread 3668 exit events, and so we have no idea whatsoever if the 3669 previously stepping thread is still alive. For that 3670 reason, we need to synchronously query the target 3671 now. */ 3672 if (is_exited (tp->ptid) 3673 || !target_thread_alive (tp->ptid)) 3674 { 3675 if (debug_infrun) 3676 fprintf_unfiltered (gdb_stdlog, "\ 3677 infrun: not switching back to stepped thread, it has vanished\n"); 3678 3679 delete_thread (tp->ptid); 3680 keep_going (ecs); 3681 return; 3682 } 3683 3684 /* Otherwise, we no longer expect a trap in the current thread. 3685 Clear the trap_expected flag before switching back -- this is 3686 what keep_going would do as well, if we called it. */ 3687 ecs->event_thread->trap_expected = 0; 3688 3689 if (debug_infrun) 3690 fprintf_unfiltered (gdb_stdlog, 3691 "infrun: switching back to stepped thread\n"); 3692 3693 ecs->event_thread = tp; 3694 ecs->ptid = tp->ptid; 3695 context_switch (ecs->ptid); 3696 keep_going (ecs); 3697 return; 3698 } 3699 } 3700 3701 /* Are we stepping to get the inferior out of the dynamic linker's 3702 hook (and possibly the dld itself) after catching a shlib 3703 event? */ 3704 if (ecs->event_thread->stepping_through_solib_after_catch) 3705 { 3706 #if defined(SOLIB_ADD) 3707 /* Have we reached our destination? If not, keep going. */ 3708 if (SOLIB_IN_DYNAMIC_LINKER (PIDGET (ecs->ptid), stop_pc)) 3709 { 3710 if (debug_infrun) 3711 fprintf_unfiltered (gdb_stdlog, "infrun: stepping in dynamic linker\n"); 3712 ecs->event_thread->stepping_over_breakpoint = 1; 3713 keep_going (ecs); 3714 return; 3715 } 3716 #endif 3717 if (debug_infrun) 3718 fprintf_unfiltered (gdb_stdlog, "infrun: step past dynamic linker\n"); 3719 /* Else, stop and report the catchpoint(s) whose triggering 3720 caused us to begin stepping. */ 3721 ecs->event_thread->stepping_through_solib_after_catch = 0; 3722 bpstat_clear (&ecs->event_thread->stop_bpstat); 3723 ecs->event_thread->stop_bpstat 3724 = bpstat_copy (ecs->event_thread->stepping_through_solib_catchpoints); 3725 bpstat_clear (&ecs->event_thread->stepping_through_solib_catchpoints); 3726 stop_print_frame = 1; 3727 stop_stepping (ecs); 3728 return; 3729 } 3730 3731 if (ecs->event_thread->step_resume_breakpoint) 3732 { 3733 if (debug_infrun) 3734 fprintf_unfiltered (gdb_stdlog, 3735 "infrun: step-resume breakpoint is inserted\n"); 3736 3737 /* Having a step-resume breakpoint overrides anything 3738 else having to do with stepping commands until 3739 that breakpoint is reached. */ 3740 keep_going (ecs); 3741 return; 3742 } 3743 3744 if (ecs->event_thread->step_range_end == 0) 3745 { 3746 if (debug_infrun) 3747 fprintf_unfiltered (gdb_stdlog, "infrun: no stepping, continue\n"); 3748 /* Likewise if we aren't even stepping. */ 3749 keep_going (ecs); 3750 return; 3751 } 3752 3753 /* If stepping through a line, keep going if still within it. 3754 3755 Note that step_range_end is the address of the first instruction 3756 beyond the step range, and NOT the address of the last instruction 3757 within it! 3758 3759 Note also that during reverse execution, we may be stepping 3760 through a function epilogue and therefore must detect when 3761 the current-frame changes in the middle of a line. */ 3762 3763 if (stop_pc >= ecs->event_thread->step_range_start 3764 && stop_pc < ecs->event_thread->step_range_end 3765 && (execution_direction != EXEC_REVERSE 3766 || frame_id_eq (get_frame_id (frame), 3767 ecs->event_thread->step_frame_id))) 3768 { 3769 if (debug_infrun) 3770 fprintf_unfiltered 3771 (gdb_stdlog, "infrun: stepping inside range [%s-%s]\n", 3772 paddress (gdbarch, ecs->event_thread->step_range_start), 3773 paddress (gdbarch, ecs->event_thread->step_range_end)); 3774 3775 /* When stepping backward, stop at beginning of line range 3776 (unless it's the function entry point, in which case 3777 keep going back to the call point). */ 3778 if (stop_pc == ecs->event_thread->step_range_start 3779 && stop_pc != ecs->stop_func_start 3780 && execution_direction == EXEC_REVERSE) 3781 { 3782 ecs->event_thread->stop_step = 1; 3783 print_stop_reason (END_STEPPING_RANGE, 0); 3784 stop_stepping (ecs); 3785 } 3786 else 3787 keep_going (ecs); 3788 3789 return; 3790 } 3791 3792 /* We stepped out of the stepping range. */ 3793 3794 /* If we are stepping at the source level and entered the runtime 3795 loader dynamic symbol resolution code... 3796 3797 EXEC_FORWARD: we keep on single stepping until we exit the run 3798 time loader code and reach the callee's address. 3799 3800 EXEC_REVERSE: we've already executed the callee (backward), and 3801 the runtime loader code is handled just like any other 3802 undebuggable function call. Now we need only keep stepping 3803 backward through the trampoline code, and that's handled further 3804 down, so there is nothing for us to do here. */ 3805 3806 if (execution_direction != EXEC_REVERSE 3807 && ecs->event_thread->step_over_calls == STEP_OVER_UNDEBUGGABLE 3808 && in_solib_dynsym_resolve_code (stop_pc)) 3809 { 3810 CORE_ADDR pc_after_resolver = 3811 gdbarch_skip_solib_resolver (gdbarch, stop_pc); 3812 3813 if (debug_infrun) 3814 fprintf_unfiltered (gdb_stdlog, "infrun: stepped into dynsym resolve code\n"); 3815 3816 if (pc_after_resolver) 3817 { 3818 /* Set up a step-resume breakpoint at the address 3819 indicated by SKIP_SOLIB_RESOLVER. */ 3820 struct symtab_and_line sr_sal; 3821 init_sal (&sr_sal); 3822 sr_sal.pc = pc_after_resolver; 3823 3824 insert_step_resume_breakpoint_at_sal (gdbarch, 3825 sr_sal, null_frame_id); 3826 } 3827 3828 keep_going (ecs); 3829 return; 3830 } 3831 3832 if (ecs->event_thread->step_range_end != 1 3833 && (ecs->event_thread->step_over_calls == STEP_OVER_UNDEBUGGABLE 3834 || ecs->event_thread->step_over_calls == STEP_OVER_ALL) 3835 && get_frame_type (frame) == SIGTRAMP_FRAME) 3836 { 3837 if (debug_infrun) 3838 fprintf_unfiltered (gdb_stdlog, "infrun: stepped into signal trampoline\n"); 3839 /* The inferior, while doing a "step" or "next", has ended up in 3840 a signal trampoline (either by a signal being delivered or by 3841 the signal handler returning). Just single-step until the 3842 inferior leaves the trampoline (either by calling the handler 3843 or returning). */ 3844 keep_going (ecs); 3845 return; 3846 } 3847 3848 /* Check for subroutine calls. The check for the current frame 3849 equalling the step ID is not necessary - the check of the 3850 previous frame's ID is sufficient - but it is a common case and 3851 cheaper than checking the previous frame's ID. 3852 3853 NOTE: frame_id_eq will never report two invalid frame IDs as 3854 being equal, so to get into this block, both the current and 3855 previous frame must have valid frame IDs. */ 3856 /* The outer_frame_id check is a heuristic to detect stepping 3857 through startup code. If we step over an instruction which 3858 sets the stack pointer from an invalid value to a valid value, 3859 we may detect that as a subroutine call from the mythical 3860 "outermost" function. This could be fixed by marking 3861 outermost frames as !stack_p,code_p,special_p. Then the 3862 initial outermost frame, before sp was valid, would 3863 have code_addr == &_start. See the commend in frame_id_eq 3864 for more. */ 3865 if (!frame_id_eq (get_stack_frame_id (frame), 3866 ecs->event_thread->step_stack_frame_id) 3867 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()), 3868 ecs->event_thread->step_stack_frame_id) 3869 && (!frame_id_eq (ecs->event_thread->step_stack_frame_id, 3870 outer_frame_id) 3871 || step_start_function != find_pc_function (stop_pc)))) 3872 { 3873 CORE_ADDR real_stop_pc; 3874 3875 if (debug_infrun) 3876 fprintf_unfiltered (gdb_stdlog, "infrun: stepped into subroutine\n"); 3877 3878 if ((ecs->event_thread->step_over_calls == STEP_OVER_NONE) 3879 || ((ecs->event_thread->step_range_end == 1) 3880 && in_prologue (gdbarch, ecs->event_thread->prev_pc, 3881 ecs->stop_func_start))) 3882 { 3883 /* I presume that step_over_calls is only 0 when we're 3884 supposed to be stepping at the assembly language level 3885 ("stepi"). Just stop. */ 3886 /* Also, maybe we just did a "nexti" inside a prolog, so we 3887 thought it was a subroutine call but it was not. Stop as 3888 well. FENN */ 3889 /* And this works the same backward as frontward. MVS */ 3890 ecs->event_thread->stop_step = 1; 3891 print_stop_reason (END_STEPPING_RANGE, 0); 3892 stop_stepping (ecs); 3893 return; 3894 } 3895 3896 /* Reverse stepping through solib trampolines. */ 3897 3898 if (execution_direction == EXEC_REVERSE 3899 && ecs->event_thread->step_over_calls != STEP_OVER_NONE 3900 && (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc) 3901 || (ecs->stop_func_start == 0 3902 && in_solib_dynsym_resolve_code (stop_pc)))) 3903 { 3904 /* Any solib trampoline code can be handled in reverse 3905 by simply continuing to single-step. We have already 3906 executed the solib function (backwards), and a few 3907 steps will take us back through the trampoline to the 3908 caller. */ 3909 keep_going (ecs); 3910 return; 3911 } 3912 3913 if (ecs->event_thread->step_over_calls == STEP_OVER_ALL) 3914 { 3915 /* We're doing a "next". 3916 3917 Normal (forward) execution: set a breakpoint at the 3918 callee's return address (the address at which the caller 3919 will resume). 3920 3921 Reverse (backward) execution. set the step-resume 3922 breakpoint at the start of the function that we just 3923 stepped into (backwards), and continue to there. When we 3924 get there, we'll need to single-step back to the caller. */ 3925 3926 if (execution_direction == EXEC_REVERSE) 3927 { 3928 struct symtab_and_line sr_sal; 3929 3930 /* Normal function call return (static or dynamic). */ 3931 init_sal (&sr_sal); 3932 sr_sal.pc = ecs->stop_func_start; 3933 insert_step_resume_breakpoint_at_sal (gdbarch, 3934 sr_sal, null_frame_id); 3935 } 3936 else 3937 insert_step_resume_breakpoint_at_caller (frame); 3938 3939 keep_going (ecs); 3940 return; 3941 } 3942 3943 /* If we are in a function call trampoline (a stub between the 3944 calling routine and the real function), locate the real 3945 function. That's what tells us (a) whether we want to step 3946 into it at all, and (b) what prologue we want to run to the 3947 end of, if we do step into it. */ 3948 real_stop_pc = skip_language_trampoline (frame, stop_pc); 3949 if (real_stop_pc == 0) 3950 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc); 3951 if (real_stop_pc != 0) 3952 ecs->stop_func_start = real_stop_pc; 3953 3954 if (real_stop_pc != 0 && in_solib_dynsym_resolve_code (real_stop_pc)) 3955 { 3956 struct symtab_and_line sr_sal; 3957 init_sal (&sr_sal); 3958 sr_sal.pc = ecs->stop_func_start; 3959 3960 insert_step_resume_breakpoint_at_sal (gdbarch, 3961 sr_sal, null_frame_id); 3962 keep_going (ecs); 3963 return; 3964 } 3965 3966 /* If we have line number information for the function we are 3967 thinking of stepping into, step into it. 3968 3969 If there are several symtabs at that PC (e.g. with include 3970 files), just want to know whether *any* of them have line 3971 numbers. find_pc_line handles this. */ 3972 { 3973 struct symtab_and_line tmp_sal; 3974 3975 tmp_sal = find_pc_line (ecs->stop_func_start, 0); 3976 if (tmp_sal.line != 0) 3977 { 3978 if (execution_direction == EXEC_REVERSE) 3979 handle_step_into_function_backward (gdbarch, ecs); 3980 else 3981 handle_step_into_function (gdbarch, ecs); 3982 return; 3983 } 3984 } 3985 3986 /* If we have no line number and the step-stop-if-no-debug is 3987 set, we stop the step so that the user has a chance to switch 3988 in assembly mode. */ 3989 if (ecs->event_thread->step_over_calls == STEP_OVER_UNDEBUGGABLE 3990 && step_stop_if_no_debug) 3991 { 3992 ecs->event_thread->stop_step = 1; 3993 print_stop_reason (END_STEPPING_RANGE, 0); 3994 stop_stepping (ecs); 3995 return; 3996 } 3997 3998 if (execution_direction == EXEC_REVERSE) 3999 { 4000 /* Set a breakpoint at callee's start address. 4001 From there we can step once and be back in the caller. */ 4002 struct symtab_and_line sr_sal; 4003 init_sal (&sr_sal); 4004 sr_sal.pc = ecs->stop_func_start; 4005 insert_step_resume_breakpoint_at_sal (gdbarch, 4006 sr_sal, null_frame_id); 4007 } 4008 else 4009 /* Set a breakpoint at callee's return address (the address 4010 at which the caller will resume). */ 4011 insert_step_resume_breakpoint_at_caller (frame); 4012 4013 keep_going (ecs); 4014 return; 4015 } 4016 4017 /* Reverse stepping through solib trampolines. */ 4018 4019 if (execution_direction == EXEC_REVERSE 4020 && ecs->event_thread->step_over_calls != STEP_OVER_NONE) 4021 { 4022 if (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc) 4023 || (ecs->stop_func_start == 0 4024 && in_solib_dynsym_resolve_code (stop_pc))) 4025 { 4026 /* Any solib trampoline code can be handled in reverse 4027 by simply continuing to single-step. We have already 4028 executed the solib function (backwards), and a few 4029 steps will take us back through the trampoline to the 4030 caller. */ 4031 keep_going (ecs); 4032 return; 4033 } 4034 else if (in_solib_dynsym_resolve_code (stop_pc)) 4035 { 4036 /* Stepped backward into the solib dynsym resolver. 4037 Set a breakpoint at its start and continue, then 4038 one more step will take us out. */ 4039 struct symtab_and_line sr_sal; 4040 init_sal (&sr_sal); 4041 sr_sal.pc = ecs->stop_func_start; 4042 insert_step_resume_breakpoint_at_sal (gdbarch, 4043 sr_sal, null_frame_id); 4044 keep_going (ecs); 4045 return; 4046 } 4047 } 4048 4049 /* If we're in the return path from a shared library trampoline, 4050 we want to proceed through the trampoline when stepping. */ 4051 if (gdbarch_in_solib_return_trampoline (gdbarch, 4052 stop_pc, ecs->stop_func_name)) 4053 { 4054 /* Determine where this trampoline returns. */ 4055 CORE_ADDR real_stop_pc; 4056 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc); 4057 4058 if (debug_infrun) 4059 fprintf_unfiltered (gdb_stdlog, "infrun: stepped into solib return tramp\n"); 4060 4061 /* Only proceed through if we know where it's going. */ 4062 if (real_stop_pc) 4063 { 4064 /* And put the step-breakpoint there and go until there. */ 4065 struct symtab_and_line sr_sal; 4066 4067 init_sal (&sr_sal); /* initialize to zeroes */ 4068 sr_sal.pc = real_stop_pc; 4069 sr_sal.section = find_pc_overlay (sr_sal.pc); 4070 4071 /* Do not specify what the fp should be when we stop since 4072 on some machines the prologue is where the new fp value 4073 is established. */ 4074 insert_step_resume_breakpoint_at_sal (gdbarch, 4075 sr_sal, null_frame_id); 4076 4077 /* Restart without fiddling with the step ranges or 4078 other state. */ 4079 keep_going (ecs); 4080 return; 4081 } 4082 } 4083 4084 stop_pc_sal = find_pc_line (stop_pc, 0); 4085 4086 /* NOTE: tausq/2004-05-24: This if block used to be done before all 4087 the trampoline processing logic, however, there are some trampolines 4088 that have no names, so we should do trampoline handling first. */ 4089 if (ecs->event_thread->step_over_calls == STEP_OVER_UNDEBUGGABLE 4090 && ecs->stop_func_name == NULL 4091 && stop_pc_sal.line == 0) 4092 { 4093 if (debug_infrun) 4094 fprintf_unfiltered (gdb_stdlog, "infrun: stepped into undebuggable function\n"); 4095 4096 /* The inferior just stepped into, or returned to, an 4097 undebuggable function (where there is no debugging information 4098 and no line number corresponding to the address where the 4099 inferior stopped). Since we want to skip this kind of code, 4100 we keep going until the inferior returns from this 4101 function - unless the user has asked us not to (via 4102 set step-mode) or we no longer know how to get back 4103 to the call site. */ 4104 if (step_stop_if_no_debug 4105 || !frame_id_p (frame_unwind_caller_id (frame))) 4106 { 4107 /* If we have no line number and the step-stop-if-no-debug 4108 is set, we stop the step so that the user has a chance to 4109 switch in assembly mode. */ 4110 ecs->event_thread->stop_step = 1; 4111 print_stop_reason (END_STEPPING_RANGE, 0); 4112 stop_stepping (ecs); 4113 return; 4114 } 4115 else 4116 { 4117 /* Set a breakpoint at callee's return address (the address 4118 at which the caller will resume). */ 4119 insert_step_resume_breakpoint_at_caller (frame); 4120 keep_going (ecs); 4121 return; 4122 } 4123 } 4124 4125 if (ecs->event_thread->step_range_end == 1) 4126 { 4127 /* It is stepi or nexti. We always want to stop stepping after 4128 one instruction. */ 4129 if (debug_infrun) 4130 fprintf_unfiltered (gdb_stdlog, "infrun: stepi/nexti\n"); 4131 ecs->event_thread->stop_step = 1; 4132 print_stop_reason (END_STEPPING_RANGE, 0); 4133 stop_stepping (ecs); 4134 return; 4135 } 4136 4137 if (stop_pc_sal.line == 0) 4138 { 4139 /* We have no line number information. That means to stop 4140 stepping (does this always happen right after one instruction, 4141 when we do "s" in a function with no line numbers, 4142 or can this happen as a result of a return or longjmp?). */ 4143 if (debug_infrun) 4144 fprintf_unfiltered (gdb_stdlog, "infrun: no line number info\n"); 4145 ecs->event_thread->stop_step = 1; 4146 print_stop_reason (END_STEPPING_RANGE, 0); 4147 stop_stepping (ecs); 4148 return; 4149 } 4150 4151 /* Look for "calls" to inlined functions, part one. If the inline 4152 frame machinery detected some skipped call sites, we have entered 4153 a new inline function. */ 4154 4155 if (frame_id_eq (get_frame_id (get_current_frame ()), 4156 ecs->event_thread->step_frame_id) 4157 && inline_skipped_frames (ecs->ptid)) 4158 { 4159 struct symtab_and_line call_sal; 4160 4161 if (debug_infrun) 4162 fprintf_unfiltered (gdb_stdlog, 4163 "infrun: stepped into inlined function\n"); 4164 4165 find_frame_sal (get_current_frame (), &call_sal); 4166 4167 if (ecs->event_thread->step_over_calls != STEP_OVER_ALL) 4168 { 4169 /* For "step", we're going to stop. But if the call site 4170 for this inlined function is on the same source line as 4171 we were previously stepping, go down into the function 4172 first. Otherwise stop at the call site. */ 4173 4174 if (call_sal.line == ecs->event_thread->current_line 4175 && call_sal.symtab == ecs->event_thread->current_symtab) 4176 step_into_inline_frame (ecs->ptid); 4177 4178 ecs->event_thread->stop_step = 1; 4179 print_stop_reason (END_STEPPING_RANGE, 0); 4180 stop_stepping (ecs); 4181 return; 4182 } 4183 else 4184 { 4185 /* For "next", we should stop at the call site if it is on a 4186 different source line. Otherwise continue through the 4187 inlined function. */ 4188 if (call_sal.line == ecs->event_thread->current_line 4189 && call_sal.symtab == ecs->event_thread->current_symtab) 4190 keep_going (ecs); 4191 else 4192 { 4193 ecs->event_thread->stop_step = 1; 4194 print_stop_reason (END_STEPPING_RANGE, 0); 4195 stop_stepping (ecs); 4196 } 4197 return; 4198 } 4199 } 4200 4201 /* Look for "calls" to inlined functions, part two. If we are still 4202 in the same real function we were stepping through, but we have 4203 to go further up to find the exact frame ID, we are stepping 4204 through a more inlined call beyond its call site. */ 4205 4206 if (get_frame_type (get_current_frame ()) == INLINE_FRAME 4207 && !frame_id_eq (get_frame_id (get_current_frame ()), 4208 ecs->event_thread->step_frame_id) 4209 && stepped_in_from (get_current_frame (), 4210 ecs->event_thread->step_frame_id)) 4211 { 4212 if (debug_infrun) 4213 fprintf_unfiltered (gdb_stdlog, 4214 "infrun: stepping through inlined function\n"); 4215 4216 if (ecs->event_thread->step_over_calls == STEP_OVER_ALL) 4217 keep_going (ecs); 4218 else 4219 { 4220 ecs->event_thread->stop_step = 1; 4221 print_stop_reason (END_STEPPING_RANGE, 0); 4222 stop_stepping (ecs); 4223 } 4224 return; 4225 } 4226 4227 if ((stop_pc == stop_pc_sal.pc) 4228 && (ecs->event_thread->current_line != stop_pc_sal.line 4229 || ecs->event_thread->current_symtab != stop_pc_sal.symtab)) 4230 { 4231 /* We are at the start of a different line. So stop. Note that 4232 we don't stop if we step into the middle of a different line. 4233 That is said to make things like for (;;) statements work 4234 better. */ 4235 if (debug_infrun) 4236 fprintf_unfiltered (gdb_stdlog, "infrun: stepped to a different line\n"); 4237 ecs->event_thread->stop_step = 1; 4238 print_stop_reason (END_STEPPING_RANGE, 0); 4239 stop_stepping (ecs); 4240 return; 4241 } 4242 4243 /* We aren't done stepping. 4244 4245 Optimize by setting the stepping range to the line. 4246 (We might not be in the original line, but if we entered a 4247 new line in mid-statement, we continue stepping. This makes 4248 things like for(;;) statements work better.) */ 4249 4250 ecs->event_thread->step_range_start = stop_pc_sal.pc; 4251 ecs->event_thread->step_range_end = stop_pc_sal.end; 4252 set_step_info (frame, stop_pc_sal); 4253 4254 if (debug_infrun) 4255 fprintf_unfiltered (gdb_stdlog, "infrun: keep going\n"); 4256 keep_going (ecs); 4257 } 4258 4259 /* Is thread TP in the middle of single-stepping? */ 4260 4261 static int 4262 currently_stepping (struct thread_info *tp) 4263 { 4264 return ((tp->step_range_end && tp->step_resume_breakpoint == NULL) 4265 || tp->trap_expected 4266 || tp->stepping_through_solib_after_catch 4267 || bpstat_should_step ()); 4268 } 4269 4270 /* Returns true if any thread *but* the one passed in "data" is in the 4271 middle of stepping or of handling a "next". */ 4272 4273 static int 4274 currently_stepping_or_nexting_callback (struct thread_info *tp, void *data) 4275 { 4276 if (tp == data) 4277 return 0; 4278 4279 return (tp->step_range_end 4280 || tp->trap_expected 4281 || tp->stepping_through_solib_after_catch); 4282 } 4283 4284 /* Inferior has stepped into a subroutine call with source code that 4285 we should not step over. Do step to the first line of code in 4286 it. */ 4287 4288 static void 4289 handle_step_into_function (struct gdbarch *gdbarch, 4290 struct execution_control_state *ecs) 4291 { 4292 struct symtab *s; 4293 struct symtab_and_line stop_func_sal, sr_sal; 4294 4295 s = find_pc_symtab (stop_pc); 4296 if (s && s->language != language_asm) 4297 ecs->stop_func_start = gdbarch_skip_prologue (gdbarch, 4298 ecs->stop_func_start); 4299 4300 stop_func_sal = find_pc_line (ecs->stop_func_start, 0); 4301 /* Use the step_resume_break to step until the end of the prologue, 4302 even if that involves jumps (as it seems to on the vax under 4303 4.2). */ 4304 /* If the prologue ends in the middle of a source line, continue to 4305 the end of that source line (if it is still within the function). 4306 Otherwise, just go to end of prologue. */ 4307 if (stop_func_sal.end 4308 && stop_func_sal.pc != ecs->stop_func_start 4309 && stop_func_sal.end < ecs->stop_func_end) 4310 ecs->stop_func_start = stop_func_sal.end; 4311 4312 /* Architectures which require breakpoint adjustment might not be able 4313 to place a breakpoint at the computed address. If so, the test 4314 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust 4315 ecs->stop_func_start to an address at which a breakpoint may be 4316 legitimately placed. 4317 4318 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not 4319 made, GDB will enter an infinite loop when stepping through 4320 optimized code consisting of VLIW instructions which contain 4321 subinstructions corresponding to different source lines. On 4322 FR-V, it's not permitted to place a breakpoint on any but the 4323 first subinstruction of a VLIW instruction. When a breakpoint is 4324 set, GDB will adjust the breakpoint address to the beginning of 4325 the VLIW instruction. Thus, we need to make the corresponding 4326 adjustment here when computing the stop address. */ 4327 4328 if (gdbarch_adjust_breakpoint_address_p (gdbarch)) 4329 { 4330 ecs->stop_func_start 4331 = gdbarch_adjust_breakpoint_address (gdbarch, 4332 ecs->stop_func_start); 4333 } 4334 4335 if (ecs->stop_func_start == stop_pc) 4336 { 4337 /* We are already there: stop now. */ 4338 ecs->event_thread->stop_step = 1; 4339 print_stop_reason (END_STEPPING_RANGE, 0); 4340 stop_stepping (ecs); 4341 return; 4342 } 4343 else 4344 { 4345 /* Put the step-breakpoint there and go until there. */ 4346 init_sal (&sr_sal); /* initialize to zeroes */ 4347 sr_sal.pc = ecs->stop_func_start; 4348 sr_sal.section = find_pc_overlay (ecs->stop_func_start); 4349 4350 /* Do not specify what the fp should be when we stop since on 4351 some machines the prologue is where the new fp value is 4352 established. */ 4353 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal, null_frame_id); 4354 4355 /* And make sure stepping stops right away then. */ 4356 ecs->event_thread->step_range_end = ecs->event_thread->step_range_start; 4357 } 4358 keep_going (ecs); 4359 } 4360 4361 /* Inferior has stepped backward into a subroutine call with source 4362 code that we should not step over. Do step to the beginning of the 4363 last line of code in it. */ 4364 4365 static void 4366 handle_step_into_function_backward (struct gdbarch *gdbarch, 4367 struct execution_control_state *ecs) 4368 { 4369 struct symtab *s; 4370 struct symtab_and_line stop_func_sal, sr_sal; 4371 4372 s = find_pc_symtab (stop_pc); 4373 if (s && s->language != language_asm) 4374 ecs->stop_func_start = gdbarch_skip_prologue (gdbarch, 4375 ecs->stop_func_start); 4376 4377 stop_func_sal = find_pc_line (stop_pc, 0); 4378 4379 /* OK, we're just going to keep stepping here. */ 4380 if (stop_func_sal.pc == stop_pc) 4381 { 4382 /* We're there already. Just stop stepping now. */ 4383 ecs->event_thread->stop_step = 1; 4384 print_stop_reason (END_STEPPING_RANGE, 0); 4385 stop_stepping (ecs); 4386 } 4387 else 4388 { 4389 /* Else just reset the step range and keep going. 4390 No step-resume breakpoint, they don't work for 4391 epilogues, which can have multiple entry paths. */ 4392 ecs->event_thread->step_range_start = stop_func_sal.pc; 4393 ecs->event_thread->step_range_end = stop_func_sal.end; 4394 keep_going (ecs); 4395 } 4396 return; 4397 } 4398 4399 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID. 4400 This is used to both functions and to skip over code. */ 4401 4402 static void 4403 insert_step_resume_breakpoint_at_sal (struct gdbarch *gdbarch, 4404 struct symtab_and_line sr_sal, 4405 struct frame_id sr_id) 4406 { 4407 /* There should never be more than one step-resume or longjmp-resume 4408 breakpoint per thread, so we should never be setting a new 4409 step_resume_breakpoint when one is already active. */ 4410 gdb_assert (inferior_thread ()->step_resume_breakpoint == NULL); 4411 4412 if (debug_infrun) 4413 fprintf_unfiltered (gdb_stdlog, 4414 "infrun: inserting step-resume breakpoint at %s\n", 4415 paddress (gdbarch, sr_sal.pc)); 4416 4417 inferior_thread ()->step_resume_breakpoint 4418 = set_momentary_breakpoint (gdbarch, sr_sal, sr_id, bp_step_resume); 4419 } 4420 4421 /* Insert a "step-resume breakpoint" at RETURN_FRAME.pc. This is used 4422 to skip a potential signal handler. 4423 4424 This is called with the interrupted function's frame. The signal 4425 handler, when it returns, will resume the interrupted function at 4426 RETURN_FRAME.pc. */ 4427 4428 static void 4429 insert_step_resume_breakpoint_at_frame (struct frame_info *return_frame) 4430 { 4431 struct symtab_and_line sr_sal; 4432 struct gdbarch *gdbarch; 4433 4434 gdb_assert (return_frame != NULL); 4435 init_sal (&sr_sal); /* initialize to zeros */ 4436 4437 gdbarch = get_frame_arch (return_frame); 4438 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch, get_frame_pc (return_frame)); 4439 sr_sal.section = find_pc_overlay (sr_sal.pc); 4440 4441 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal, 4442 get_stack_frame_id (return_frame)); 4443 } 4444 4445 /* Similar to insert_step_resume_breakpoint_at_frame, except 4446 but a breakpoint at the previous frame's PC. This is used to 4447 skip a function after stepping into it (for "next" or if the called 4448 function has no debugging information). 4449 4450 The current function has almost always been reached by single 4451 stepping a call or return instruction. NEXT_FRAME belongs to the 4452 current function, and the breakpoint will be set at the caller's 4453 resume address. 4454 4455 This is a separate function rather than reusing 4456 insert_step_resume_breakpoint_at_frame in order to avoid 4457 get_prev_frame, which may stop prematurely (see the implementation 4458 of frame_unwind_caller_id for an example). */ 4459 4460 static void 4461 insert_step_resume_breakpoint_at_caller (struct frame_info *next_frame) 4462 { 4463 struct symtab_and_line sr_sal; 4464 struct gdbarch *gdbarch; 4465 4466 /* We shouldn't have gotten here if we don't know where the call site 4467 is. */ 4468 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame))); 4469 4470 init_sal (&sr_sal); /* initialize to zeros */ 4471 4472 gdbarch = frame_unwind_caller_arch (next_frame); 4473 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch, 4474 frame_unwind_caller_pc (next_frame)); 4475 sr_sal.section = find_pc_overlay (sr_sal.pc); 4476 4477 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal, 4478 frame_unwind_caller_id (next_frame)); 4479 } 4480 4481 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a 4482 new breakpoint at the target of a jmp_buf. The handling of 4483 longjmp-resume uses the same mechanisms used for handling 4484 "step-resume" breakpoints. */ 4485 4486 static void 4487 insert_longjmp_resume_breakpoint (struct gdbarch *gdbarch, CORE_ADDR pc) 4488 { 4489 /* There should never be more than one step-resume or longjmp-resume 4490 breakpoint per thread, so we should never be setting a new 4491 longjmp_resume_breakpoint when one is already active. */ 4492 gdb_assert (inferior_thread ()->step_resume_breakpoint == NULL); 4493 4494 if (debug_infrun) 4495 fprintf_unfiltered (gdb_stdlog, 4496 "infrun: inserting longjmp-resume breakpoint at %s\n", 4497 paddress (gdbarch, pc)); 4498 4499 inferior_thread ()->step_resume_breakpoint = 4500 set_momentary_breakpoint_at_pc (gdbarch, pc, bp_longjmp_resume); 4501 } 4502 4503 static void 4504 stop_stepping (struct execution_control_state *ecs) 4505 { 4506 if (debug_infrun) 4507 fprintf_unfiltered (gdb_stdlog, "infrun: stop_stepping\n"); 4508 4509 /* Let callers know we don't want to wait for the inferior anymore. */ 4510 ecs->wait_some_more = 0; 4511 } 4512 4513 /* This function handles various cases where we need to continue 4514 waiting for the inferior. */ 4515 /* (Used to be the keep_going: label in the old wait_for_inferior) */ 4516 4517 static void 4518 keep_going (struct execution_control_state *ecs) 4519 { 4520 /* Save the pc before execution, to compare with pc after stop. */ 4521 ecs->event_thread->prev_pc 4522 = regcache_read_pc (get_thread_regcache (ecs->ptid)); 4523 4524 /* If we did not do break;, it means we should keep running the 4525 inferior and not return to debugger. */ 4526 4527 if (ecs->event_thread->trap_expected 4528 && ecs->event_thread->stop_signal != TARGET_SIGNAL_TRAP) 4529 { 4530 /* We took a signal (which we are supposed to pass through to 4531 the inferior, else we'd not get here) and we haven't yet 4532 gotten our trap. Simply continue. */ 4533 resume (currently_stepping (ecs->event_thread), 4534 ecs->event_thread->stop_signal); 4535 } 4536 else 4537 { 4538 /* Either the trap was not expected, but we are continuing 4539 anyway (the user asked that this signal be passed to the 4540 child) 4541 -- or -- 4542 The signal was SIGTRAP, e.g. it was our signal, but we 4543 decided we should resume from it. 4544 4545 We're going to run this baby now! 4546 4547 Note that insert_breakpoints won't try to re-insert 4548 already inserted breakpoints. Therefore, we don't 4549 care if breakpoints were already inserted, or not. */ 4550 4551 if (ecs->event_thread->stepping_over_breakpoint) 4552 { 4553 struct regcache *thread_regcache = get_thread_regcache (ecs->ptid); 4554 if (!use_displaced_stepping (get_regcache_arch (thread_regcache))) 4555 /* Since we can't do a displaced step, we have to remove 4556 the breakpoint while we step it. To keep things 4557 simple, we remove them all. */ 4558 remove_breakpoints (); 4559 } 4560 else 4561 { 4562 struct gdb_exception e; 4563 /* Stop stepping when inserting breakpoints 4564 has failed. */ 4565 TRY_CATCH (e, RETURN_MASK_ERROR) 4566 { 4567 insert_breakpoints (); 4568 } 4569 if (e.reason < 0) 4570 { 4571 stop_stepping (ecs); 4572 return; 4573 } 4574 } 4575 4576 ecs->event_thread->trap_expected = ecs->event_thread->stepping_over_breakpoint; 4577 4578 /* Do not deliver SIGNAL_TRAP (except when the user explicitly 4579 specifies that such a signal should be delivered to the 4580 target program). 4581 4582 Typically, this would occure when a user is debugging a 4583 target monitor on a simulator: the target monitor sets a 4584 breakpoint; the simulator encounters this break-point and 4585 halts the simulation handing control to GDB; GDB, noteing 4586 that the break-point isn't valid, returns control back to the 4587 simulator; the simulator then delivers the hardware 4588 equivalent of a SIGNAL_TRAP to the program being debugged. */ 4589 4590 if (ecs->event_thread->stop_signal == TARGET_SIGNAL_TRAP 4591 && !signal_program[ecs->event_thread->stop_signal]) 4592 ecs->event_thread->stop_signal = TARGET_SIGNAL_0; 4593 4594 resume (currently_stepping (ecs->event_thread), 4595 ecs->event_thread->stop_signal); 4596 } 4597 4598 prepare_to_wait (ecs); 4599 } 4600 4601 /* This function normally comes after a resume, before 4602 handle_inferior_event exits. It takes care of any last bits of 4603 housekeeping, and sets the all-important wait_some_more flag. */ 4604 4605 static void 4606 prepare_to_wait (struct execution_control_state *ecs) 4607 { 4608 if (debug_infrun) 4609 fprintf_unfiltered (gdb_stdlog, "infrun: prepare_to_wait\n"); 4610 4611 /* This is the old end of the while loop. Let everybody know we 4612 want to wait for the inferior some more and get called again 4613 soon. */ 4614 ecs->wait_some_more = 1; 4615 } 4616 4617 /* Print why the inferior has stopped. We always print something when 4618 the inferior exits, or receives a signal. The rest of the cases are 4619 dealt with later on in normal_stop() and print_it_typical(). Ideally 4620 there should be a call to this function from handle_inferior_event() 4621 each time stop_stepping() is called.*/ 4622 static void 4623 print_stop_reason (enum inferior_stop_reason stop_reason, int stop_info) 4624 { 4625 switch (stop_reason) 4626 { 4627 case END_STEPPING_RANGE: 4628 /* We are done with a step/next/si/ni command. */ 4629 /* For now print nothing. */ 4630 /* Print a message only if not in the middle of doing a "step n" 4631 operation for n > 1 */ 4632 if (!inferior_thread ()->step_multi 4633 || !inferior_thread ()->stop_step) 4634 if (ui_out_is_mi_like_p (uiout)) 4635 ui_out_field_string 4636 (uiout, "reason", 4637 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE)); 4638 break; 4639 case SIGNAL_EXITED: 4640 /* The inferior was terminated by a signal. */ 4641 annotate_signalled (); 4642 if (ui_out_is_mi_like_p (uiout)) 4643 ui_out_field_string 4644 (uiout, "reason", 4645 async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED)); 4646 ui_out_text (uiout, "\nProgram terminated with signal "); 4647 annotate_signal_name (); 4648 ui_out_field_string (uiout, "signal-name", 4649 target_signal_to_name (stop_info)); 4650 annotate_signal_name_end (); 4651 ui_out_text (uiout, ", "); 4652 annotate_signal_string (); 4653 ui_out_field_string (uiout, "signal-meaning", 4654 target_signal_to_string (stop_info)); 4655 annotate_signal_string_end (); 4656 ui_out_text (uiout, ".\n"); 4657 ui_out_text (uiout, "The program no longer exists.\n"); 4658 break; 4659 case EXITED: 4660 /* The inferior program is finished. */ 4661 annotate_exited (stop_info); 4662 if (stop_info) 4663 { 4664 if (ui_out_is_mi_like_p (uiout)) 4665 ui_out_field_string (uiout, "reason", 4666 async_reason_lookup (EXEC_ASYNC_EXITED)); 4667 ui_out_text (uiout, "\nProgram exited with code "); 4668 ui_out_field_fmt (uiout, "exit-code", "0%o", 4669 (unsigned int) stop_info); 4670 ui_out_text (uiout, ".\n"); 4671 } 4672 else 4673 { 4674 if (ui_out_is_mi_like_p (uiout)) 4675 ui_out_field_string 4676 (uiout, "reason", 4677 async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY)); 4678 ui_out_text (uiout, "\nProgram exited normally.\n"); 4679 } 4680 /* Support the --return-child-result option. */ 4681 return_child_result_value = stop_info; 4682 break; 4683 case SIGNAL_RECEIVED: 4684 /* Signal received. The signal table tells us to print about 4685 it. */ 4686 annotate_signal (); 4687 4688 if (stop_info == TARGET_SIGNAL_0 && !ui_out_is_mi_like_p (uiout)) 4689 { 4690 struct thread_info *t = inferior_thread (); 4691 4692 ui_out_text (uiout, "\n["); 4693 ui_out_field_string (uiout, "thread-name", 4694 target_pid_to_str (t->ptid)); 4695 ui_out_field_fmt (uiout, "thread-id", "] #%d", t->num); 4696 ui_out_text (uiout, " stopped"); 4697 } 4698 else 4699 { 4700 ui_out_text (uiout, "\nProgram received signal "); 4701 annotate_signal_name (); 4702 if (ui_out_is_mi_like_p (uiout)) 4703 ui_out_field_string 4704 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED)); 4705 ui_out_field_string (uiout, "signal-name", 4706 target_signal_to_name (stop_info)); 4707 annotate_signal_name_end (); 4708 ui_out_text (uiout, ", "); 4709 annotate_signal_string (); 4710 ui_out_field_string (uiout, "signal-meaning", 4711 target_signal_to_string (stop_info)); 4712 annotate_signal_string_end (); 4713 } 4714 ui_out_text (uiout, ".\n"); 4715 break; 4716 case NO_HISTORY: 4717 /* Reverse execution: target ran out of history info. */ 4718 ui_out_text (uiout, "\nNo more reverse-execution history.\n"); 4719 break; 4720 default: 4721 internal_error (__FILE__, __LINE__, 4722 _("print_stop_reason: unrecognized enum value")); 4723 break; 4724 } 4725 } 4726 4727 4728 /* Here to return control to GDB when the inferior stops for real. 4729 Print appropriate messages, remove breakpoints, give terminal our modes. 4730 4731 STOP_PRINT_FRAME nonzero means print the executing frame 4732 (pc, function, args, file, line number and line text). 4733 BREAKPOINTS_FAILED nonzero means stop was due to error 4734 attempting to insert breakpoints. */ 4735 4736 void 4737 normal_stop (void) 4738 { 4739 struct target_waitstatus last; 4740 ptid_t last_ptid; 4741 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL); 4742 4743 get_last_target_status (&last_ptid, &last); 4744 4745 /* If an exception is thrown from this point on, make sure to 4746 propagate GDB's knowledge of the executing state to the 4747 frontend/user running state. A QUIT is an easy exception to see 4748 here, so do this before any filtered output. */ 4749 if (!non_stop) 4750 make_cleanup (finish_thread_state_cleanup, &minus_one_ptid); 4751 else if (last.kind != TARGET_WAITKIND_SIGNALLED 4752 && last.kind != TARGET_WAITKIND_EXITED) 4753 make_cleanup (finish_thread_state_cleanup, &inferior_ptid); 4754 4755 /* In non-stop mode, we don't want GDB to switch threads behind the 4756 user's back, to avoid races where the user is typing a command to 4757 apply to thread x, but GDB switches to thread y before the user 4758 finishes entering the command. */ 4759 4760 /* As with the notification of thread events, we want to delay 4761 notifying the user that we've switched thread context until 4762 the inferior actually stops. 4763 4764 There's no point in saying anything if the inferior has exited. 4765 Note that SIGNALLED here means "exited with a signal", not 4766 "received a signal". */ 4767 if (!non_stop 4768 && !ptid_equal (previous_inferior_ptid, inferior_ptid) 4769 && target_has_execution 4770 && last.kind != TARGET_WAITKIND_SIGNALLED 4771 && last.kind != TARGET_WAITKIND_EXITED) 4772 { 4773 target_terminal_ours_for_output (); 4774 printf_filtered (_("[Switching to %s]\n"), 4775 target_pid_to_str (inferior_ptid)); 4776 annotate_thread_changed (); 4777 previous_inferior_ptid = inferior_ptid; 4778 } 4779 4780 if (!breakpoints_always_inserted_mode () && target_has_execution) 4781 { 4782 if (remove_breakpoints ()) 4783 { 4784 target_terminal_ours_for_output (); 4785 printf_filtered (_("\ 4786 Cannot remove breakpoints because program is no longer writable.\n\ 4787 Further execution is probably impossible.\n")); 4788 } 4789 } 4790 4791 /* If an auto-display called a function and that got a signal, 4792 delete that auto-display to avoid an infinite recursion. */ 4793 4794 if (stopped_by_random_signal) 4795 disable_current_display (); 4796 4797 /* Don't print a message if in the middle of doing a "step n" 4798 operation for n > 1 */ 4799 if (target_has_execution 4800 && last.kind != TARGET_WAITKIND_SIGNALLED 4801 && last.kind != TARGET_WAITKIND_EXITED 4802 && inferior_thread ()->step_multi 4803 && inferior_thread ()->stop_step) 4804 goto done; 4805 4806 target_terminal_ours (); 4807 4808 /* Set the current source location. This will also happen if we 4809 display the frame below, but the current SAL will be incorrect 4810 during a user hook-stop function. */ 4811 if (has_stack_frames () && !stop_stack_dummy) 4812 set_current_sal_from_frame (get_current_frame (), 1); 4813 4814 /* Let the user/frontend see the threads as stopped. */ 4815 do_cleanups (old_chain); 4816 4817 /* Look up the hook_stop and run it (CLI internally handles problem 4818 of stop_command's pre-hook not existing). */ 4819 if (stop_command) 4820 catch_errors (hook_stop_stub, stop_command, 4821 "Error while running hook_stop:\n", RETURN_MASK_ALL); 4822 4823 if (!has_stack_frames ()) 4824 goto done; 4825 4826 if (last.kind == TARGET_WAITKIND_SIGNALLED 4827 || last.kind == TARGET_WAITKIND_EXITED) 4828 goto done; 4829 4830 /* Select innermost stack frame - i.e., current frame is frame 0, 4831 and current location is based on that. 4832 Don't do this on return from a stack dummy routine, 4833 or if the program has exited. */ 4834 4835 if (!stop_stack_dummy) 4836 { 4837 select_frame (get_current_frame ()); 4838 4839 /* Print current location without a level number, if 4840 we have changed functions or hit a breakpoint. 4841 Print source line if we have one. 4842 bpstat_print() contains the logic deciding in detail 4843 what to print, based on the event(s) that just occurred. */ 4844 4845 /* If --batch-silent is enabled then there's no need to print the current 4846 source location, and to try risks causing an error message about 4847 missing source files. */ 4848 if (stop_print_frame && !batch_silent) 4849 { 4850 int bpstat_ret; 4851 int source_flag; 4852 int do_frame_printing = 1; 4853 struct thread_info *tp = inferior_thread (); 4854 4855 bpstat_ret = bpstat_print (tp->stop_bpstat); 4856 switch (bpstat_ret) 4857 { 4858 case PRINT_UNKNOWN: 4859 /* If we had hit a shared library event breakpoint, 4860 bpstat_print would print out this message. If we hit 4861 an OS-level shared library event, do the same 4862 thing. */ 4863 if (last.kind == TARGET_WAITKIND_LOADED) 4864 { 4865 printf_filtered (_("Stopped due to shared library event\n")); 4866 source_flag = SRC_LINE; /* something bogus */ 4867 do_frame_printing = 0; 4868 break; 4869 } 4870 4871 /* FIXME: cagney/2002-12-01: Given that a frame ID does 4872 (or should) carry around the function and does (or 4873 should) use that when doing a frame comparison. */ 4874 if (tp->stop_step 4875 && frame_id_eq (tp->step_frame_id, 4876 get_frame_id (get_current_frame ())) 4877 && step_start_function == find_pc_function (stop_pc)) 4878 source_flag = SRC_LINE; /* finished step, just print source line */ 4879 else 4880 source_flag = SRC_AND_LOC; /* print location and source line */ 4881 break; 4882 case PRINT_SRC_AND_LOC: 4883 source_flag = SRC_AND_LOC; /* print location and source line */ 4884 break; 4885 case PRINT_SRC_ONLY: 4886 source_flag = SRC_LINE; 4887 break; 4888 case PRINT_NOTHING: 4889 source_flag = SRC_LINE; /* something bogus */ 4890 do_frame_printing = 0; 4891 break; 4892 default: 4893 internal_error (__FILE__, __LINE__, _("Unknown value.")); 4894 } 4895 4896 /* The behavior of this routine with respect to the source 4897 flag is: 4898 SRC_LINE: Print only source line 4899 LOCATION: Print only location 4900 SRC_AND_LOC: Print location and source line */ 4901 if (do_frame_printing) 4902 print_stack_frame (get_selected_frame (NULL), 0, source_flag); 4903 4904 /* Display the auto-display expressions. */ 4905 do_displays (); 4906 } 4907 } 4908 4909 /* Save the function value return registers, if we care. 4910 We might be about to restore their previous contents. */ 4911 if (inferior_thread ()->proceed_to_finish) 4912 { 4913 /* This should not be necessary. */ 4914 if (stop_registers) 4915 regcache_xfree (stop_registers); 4916 4917 /* NB: The copy goes through to the target picking up the value of 4918 all the registers. */ 4919 stop_registers = regcache_dup (get_current_regcache ()); 4920 } 4921 4922 if (stop_stack_dummy) 4923 { 4924 /* Pop the empty frame that contains the stack dummy. 4925 This also restores inferior state prior to the call 4926 (struct inferior_thread_state). */ 4927 struct frame_info *frame = get_current_frame (); 4928 gdb_assert (get_frame_type (frame) == DUMMY_FRAME); 4929 frame_pop (frame); 4930 /* frame_pop() calls reinit_frame_cache as the last thing it does 4931 which means there's currently no selected frame. We don't need 4932 to re-establish a selected frame if the dummy call returns normally, 4933 that will be done by restore_inferior_status. However, we do have 4934 to handle the case where the dummy call is returning after being 4935 stopped (e.g. the dummy call previously hit a breakpoint). We 4936 can't know which case we have so just always re-establish a 4937 selected frame here. */ 4938 select_frame (get_current_frame ()); 4939 } 4940 4941 done: 4942 annotate_stopped (); 4943 4944 /* Suppress the stop observer if we're in the middle of: 4945 4946 - a step n (n > 1), as there still more steps to be done. 4947 4948 - a "finish" command, as the observer will be called in 4949 finish_command_continuation, so it can include the inferior 4950 function's return value. 4951 4952 - calling an inferior function, as we pretend we inferior didn't 4953 run at all. The return value of the call is handled by the 4954 expression evaluator, through call_function_by_hand. */ 4955 4956 if (!target_has_execution 4957 || last.kind == TARGET_WAITKIND_SIGNALLED 4958 || last.kind == TARGET_WAITKIND_EXITED 4959 || (!inferior_thread ()->step_multi 4960 && !(inferior_thread ()->stop_bpstat 4961 && inferior_thread ()->proceed_to_finish) 4962 && !inferior_thread ()->in_infcall)) 4963 { 4964 if (!ptid_equal (inferior_ptid, null_ptid)) 4965 observer_notify_normal_stop (inferior_thread ()->stop_bpstat, 4966 stop_print_frame); 4967 else 4968 observer_notify_normal_stop (NULL, stop_print_frame); 4969 } 4970 4971 if (target_has_execution) 4972 { 4973 if (last.kind != TARGET_WAITKIND_SIGNALLED 4974 && last.kind != TARGET_WAITKIND_EXITED) 4975 /* Delete the breakpoint we stopped at, if it wants to be deleted. 4976 Delete any breakpoint that is to be deleted at the next stop. */ 4977 breakpoint_auto_delete (inferior_thread ()->stop_bpstat); 4978 } 4979 } 4980 4981 static int 4982 hook_stop_stub (void *cmd) 4983 { 4984 execute_cmd_pre_hook ((struct cmd_list_element *) cmd); 4985 return (0); 4986 } 4987 4988 int 4989 signal_stop_state (int signo) 4990 { 4991 return signal_stop[signo]; 4992 } 4993 4994 int 4995 signal_print_state (int signo) 4996 { 4997 return signal_print[signo]; 4998 } 4999 5000 int 5001 signal_pass_state (int signo) 5002 { 5003 return signal_program[signo]; 5004 } 5005 5006 int 5007 signal_stop_update (int signo, int state) 5008 { 5009 int ret = signal_stop[signo]; 5010 signal_stop[signo] = state; 5011 return ret; 5012 } 5013 5014 int 5015 signal_print_update (int signo, int state) 5016 { 5017 int ret = signal_print[signo]; 5018 signal_print[signo] = state; 5019 return ret; 5020 } 5021 5022 int 5023 signal_pass_update (int signo, int state) 5024 { 5025 int ret = signal_program[signo]; 5026 signal_program[signo] = state; 5027 return ret; 5028 } 5029 5030 static void 5031 sig_print_header (void) 5032 { 5033 printf_filtered (_("\ 5034 Signal Stop\tPrint\tPass to program\tDescription\n")); 5035 } 5036 5037 static void 5038 sig_print_info (enum target_signal oursig) 5039 { 5040 const char *name = target_signal_to_name (oursig); 5041 int name_padding = 13 - strlen (name); 5042 5043 if (name_padding <= 0) 5044 name_padding = 0; 5045 5046 printf_filtered ("%s", name); 5047 printf_filtered ("%*.*s ", name_padding, name_padding, " "); 5048 printf_filtered ("%s\t", signal_stop[oursig] ? "Yes" : "No"); 5049 printf_filtered ("%s\t", signal_print[oursig] ? "Yes" : "No"); 5050 printf_filtered ("%s\t\t", signal_program[oursig] ? "Yes" : "No"); 5051 printf_filtered ("%s\n", target_signal_to_string (oursig)); 5052 } 5053 5054 /* Specify how various signals in the inferior should be handled. */ 5055 5056 static void 5057 handle_command (char *args, int from_tty) 5058 { 5059 char **argv; 5060 int digits, wordlen; 5061 int sigfirst, signum, siglast; 5062 enum target_signal oursig; 5063 int allsigs; 5064 int nsigs; 5065 unsigned char *sigs; 5066 struct cleanup *old_chain; 5067 5068 if (args == NULL) 5069 { 5070 error_no_arg (_("signal to handle")); 5071 } 5072 5073 /* Allocate and zero an array of flags for which signals to handle. */ 5074 5075 nsigs = (int) TARGET_SIGNAL_LAST; 5076 sigs = (unsigned char *) alloca (nsigs); 5077 memset (sigs, 0, nsigs); 5078 5079 /* Break the command line up into args. */ 5080 5081 argv = gdb_buildargv (args); 5082 old_chain = make_cleanup_freeargv (argv); 5083 5084 /* Walk through the args, looking for signal oursigs, signal names, and 5085 actions. Signal numbers and signal names may be interspersed with 5086 actions, with the actions being performed for all signals cumulatively 5087 specified. Signal ranges can be specified as <LOW>-<HIGH>. */ 5088 5089 while (*argv != NULL) 5090 { 5091 wordlen = strlen (*argv); 5092 for (digits = 0; isdigit ((*argv)[digits]); digits++) 5093 {; 5094 } 5095 allsigs = 0; 5096 sigfirst = siglast = -1; 5097 5098 if (wordlen >= 1 && !strncmp (*argv, "all", wordlen)) 5099 { 5100 /* Apply action to all signals except those used by the 5101 debugger. Silently skip those. */ 5102 allsigs = 1; 5103 sigfirst = 0; 5104 siglast = nsigs - 1; 5105 } 5106 else if (wordlen >= 1 && !strncmp (*argv, "stop", wordlen)) 5107 { 5108 SET_SIGS (nsigs, sigs, signal_stop); 5109 SET_SIGS (nsigs, sigs, signal_print); 5110 } 5111 else if (wordlen >= 1 && !strncmp (*argv, "ignore", wordlen)) 5112 { 5113 UNSET_SIGS (nsigs, sigs, signal_program); 5114 } 5115 else if (wordlen >= 2 && !strncmp (*argv, "print", wordlen)) 5116 { 5117 SET_SIGS (nsigs, sigs, signal_print); 5118 } 5119 else if (wordlen >= 2 && !strncmp (*argv, "pass", wordlen)) 5120 { 5121 SET_SIGS (nsigs, sigs, signal_program); 5122 } 5123 else if (wordlen >= 3 && !strncmp (*argv, "nostop", wordlen)) 5124 { 5125 UNSET_SIGS (nsigs, sigs, signal_stop); 5126 } 5127 else if (wordlen >= 3 && !strncmp (*argv, "noignore", wordlen)) 5128 { 5129 SET_SIGS (nsigs, sigs, signal_program); 5130 } 5131 else if (wordlen >= 4 && !strncmp (*argv, "noprint", wordlen)) 5132 { 5133 UNSET_SIGS (nsigs, sigs, signal_print); 5134 UNSET_SIGS (nsigs, sigs, signal_stop); 5135 } 5136 else if (wordlen >= 4 && !strncmp (*argv, "nopass", wordlen)) 5137 { 5138 UNSET_SIGS (nsigs, sigs, signal_program); 5139 } 5140 else if (digits > 0) 5141 { 5142 /* It is numeric. The numeric signal refers to our own 5143 internal signal numbering from target.h, not to host/target 5144 signal number. This is a feature; users really should be 5145 using symbolic names anyway, and the common ones like 5146 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */ 5147 5148 sigfirst = siglast = (int) 5149 target_signal_from_command (atoi (*argv)); 5150 if ((*argv)[digits] == '-') 5151 { 5152 siglast = (int) 5153 target_signal_from_command (atoi ((*argv) + digits + 1)); 5154 } 5155 if (sigfirst > siglast) 5156 { 5157 /* Bet he didn't figure we'd think of this case... */ 5158 signum = sigfirst; 5159 sigfirst = siglast; 5160 siglast = signum; 5161 } 5162 } 5163 else 5164 { 5165 oursig = target_signal_from_name (*argv); 5166 if (oursig != TARGET_SIGNAL_UNKNOWN) 5167 { 5168 sigfirst = siglast = (int) oursig; 5169 } 5170 else 5171 { 5172 /* Not a number and not a recognized flag word => complain. */ 5173 error (_("Unrecognized or ambiguous flag word: \"%s\"."), *argv); 5174 } 5175 } 5176 5177 /* If any signal numbers or symbol names were found, set flags for 5178 which signals to apply actions to. */ 5179 5180 for (signum = sigfirst; signum >= 0 && signum <= siglast; signum++) 5181 { 5182 switch ((enum target_signal) signum) 5183 { 5184 case TARGET_SIGNAL_TRAP: 5185 case TARGET_SIGNAL_INT: 5186 if (!allsigs && !sigs[signum]) 5187 { 5188 if (query (_("%s is used by the debugger.\n\ 5189 Are you sure you want to change it? "), target_signal_to_name ((enum target_signal) signum))) 5190 { 5191 sigs[signum] = 1; 5192 } 5193 else 5194 { 5195 printf_unfiltered (_("Not confirmed, unchanged.\n")); 5196 gdb_flush (gdb_stdout); 5197 } 5198 } 5199 break; 5200 case TARGET_SIGNAL_0: 5201 case TARGET_SIGNAL_DEFAULT: 5202 case TARGET_SIGNAL_UNKNOWN: 5203 /* Make sure that "all" doesn't print these. */ 5204 break; 5205 default: 5206 sigs[signum] = 1; 5207 break; 5208 } 5209 } 5210 5211 argv++; 5212 } 5213 5214 for (signum = 0; signum < nsigs; signum++) 5215 if (sigs[signum]) 5216 { 5217 target_notice_signals (inferior_ptid); 5218 5219 if (from_tty) 5220 { 5221 /* Show the results. */ 5222 sig_print_header (); 5223 for (; signum < nsigs; signum++) 5224 if (sigs[signum]) 5225 sig_print_info (signum); 5226 } 5227 5228 break; 5229 } 5230 5231 do_cleanups (old_chain); 5232 } 5233 5234 static void 5235 xdb_handle_command (char *args, int from_tty) 5236 { 5237 char **argv; 5238 struct cleanup *old_chain; 5239 5240 if (args == NULL) 5241 error_no_arg (_("xdb command")); 5242 5243 /* Break the command line up into args. */ 5244 5245 argv = gdb_buildargv (args); 5246 old_chain = make_cleanup_freeargv (argv); 5247 if (argv[1] != (char *) NULL) 5248 { 5249 char *argBuf; 5250 int bufLen; 5251 5252 bufLen = strlen (argv[0]) + 20; 5253 argBuf = (char *) xmalloc (bufLen); 5254 if (argBuf) 5255 { 5256 int validFlag = 1; 5257 enum target_signal oursig; 5258 5259 oursig = target_signal_from_name (argv[0]); 5260 memset (argBuf, 0, bufLen); 5261 if (strcmp (argv[1], "Q") == 0) 5262 sprintf (argBuf, "%s %s", argv[0], "noprint"); 5263 else 5264 { 5265 if (strcmp (argv[1], "s") == 0) 5266 { 5267 if (!signal_stop[oursig]) 5268 sprintf (argBuf, "%s %s", argv[0], "stop"); 5269 else 5270 sprintf (argBuf, "%s %s", argv[0], "nostop"); 5271 } 5272 else if (strcmp (argv[1], "i") == 0) 5273 { 5274 if (!signal_program[oursig]) 5275 sprintf (argBuf, "%s %s", argv[0], "pass"); 5276 else 5277 sprintf (argBuf, "%s %s", argv[0], "nopass"); 5278 } 5279 else if (strcmp (argv[1], "r") == 0) 5280 { 5281 if (!signal_print[oursig]) 5282 sprintf (argBuf, "%s %s", argv[0], "print"); 5283 else 5284 sprintf (argBuf, "%s %s", argv[0], "noprint"); 5285 } 5286 else 5287 validFlag = 0; 5288 } 5289 if (validFlag) 5290 handle_command (argBuf, from_tty); 5291 else 5292 printf_filtered (_("Invalid signal handling flag.\n")); 5293 if (argBuf) 5294 xfree (argBuf); 5295 } 5296 } 5297 do_cleanups (old_chain); 5298 } 5299 5300 /* Print current contents of the tables set by the handle command. 5301 It is possible we should just be printing signals actually used 5302 by the current target (but for things to work right when switching 5303 targets, all signals should be in the signal tables). */ 5304 5305 static void 5306 signals_info (char *signum_exp, int from_tty) 5307 { 5308 enum target_signal oursig; 5309 sig_print_header (); 5310 5311 if (signum_exp) 5312 { 5313 /* First see if this is a symbol name. */ 5314 oursig = target_signal_from_name (signum_exp); 5315 if (oursig == TARGET_SIGNAL_UNKNOWN) 5316 { 5317 /* No, try numeric. */ 5318 oursig = 5319 target_signal_from_command (parse_and_eval_long (signum_exp)); 5320 } 5321 sig_print_info (oursig); 5322 return; 5323 } 5324 5325 printf_filtered ("\n"); 5326 /* These ugly casts brought to you by the native VAX compiler. */ 5327 for (oursig = TARGET_SIGNAL_FIRST; 5328 (int) oursig < (int) TARGET_SIGNAL_LAST; 5329 oursig = (enum target_signal) ((int) oursig + 1)) 5330 { 5331 QUIT; 5332 5333 if (oursig != TARGET_SIGNAL_UNKNOWN 5334 && oursig != TARGET_SIGNAL_DEFAULT && oursig != TARGET_SIGNAL_0) 5335 sig_print_info (oursig); 5336 } 5337 5338 printf_filtered (_("\nUse the \"handle\" command to change these tables.\n")); 5339 } 5340 5341 /* The $_siginfo convenience variable is a bit special. We don't know 5342 for sure the type of the value until we actually have a chance to 5343 fetch the data. The type can change depending on gdbarch, so it it 5344 also dependent on which thread you have selected. 5345 5346 1. making $_siginfo be an internalvar that creates a new value on 5347 access. 5348 5349 2. making the value of $_siginfo be an lval_computed value. */ 5350 5351 /* This function implements the lval_computed support for reading a 5352 $_siginfo value. */ 5353 5354 static void 5355 siginfo_value_read (struct value *v) 5356 { 5357 LONGEST transferred; 5358 5359 transferred = 5360 target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO, 5361 NULL, 5362 value_contents_all_raw (v), 5363 value_offset (v), 5364 TYPE_LENGTH (value_type (v))); 5365 5366 if (transferred != TYPE_LENGTH (value_type (v))) 5367 error (_("Unable to read siginfo")); 5368 } 5369 5370 /* This function implements the lval_computed support for writing a 5371 $_siginfo value. */ 5372 5373 static void 5374 siginfo_value_write (struct value *v, struct value *fromval) 5375 { 5376 LONGEST transferred; 5377 5378 transferred = target_write (¤t_target, 5379 TARGET_OBJECT_SIGNAL_INFO, 5380 NULL, 5381 value_contents_all_raw (fromval), 5382 value_offset (v), 5383 TYPE_LENGTH (value_type (fromval))); 5384 5385 if (transferred != TYPE_LENGTH (value_type (fromval))) 5386 error (_("Unable to write siginfo")); 5387 } 5388 5389 static struct lval_funcs siginfo_value_funcs = 5390 { 5391 siginfo_value_read, 5392 siginfo_value_write 5393 }; 5394 5395 /* Return a new value with the correct type for the siginfo object of 5396 the current thread using architecture GDBARCH. Return a void value 5397 if there's no object available. */ 5398 5399 static struct value * 5400 siginfo_make_value (struct gdbarch *gdbarch, struct internalvar *var) 5401 { 5402 if (target_has_stack 5403 && !ptid_equal (inferior_ptid, null_ptid) 5404 && gdbarch_get_siginfo_type_p (gdbarch)) 5405 { 5406 struct type *type = gdbarch_get_siginfo_type (gdbarch); 5407 return allocate_computed_value (type, &siginfo_value_funcs, NULL); 5408 } 5409 5410 return allocate_value (builtin_type (gdbarch)->builtin_void); 5411 } 5412 5413 5414 /* Inferior thread state. 5415 These are details related to the inferior itself, and don't include 5416 things like what frame the user had selected or what gdb was doing 5417 with the target at the time. 5418 For inferior function calls these are things we want to restore 5419 regardless of whether the function call successfully completes 5420 or the dummy frame has to be manually popped. */ 5421 5422 struct inferior_thread_state 5423 { 5424 enum target_signal stop_signal; 5425 CORE_ADDR stop_pc; 5426 struct regcache *registers; 5427 }; 5428 5429 struct inferior_thread_state * 5430 save_inferior_thread_state (void) 5431 { 5432 struct inferior_thread_state *inf_state = XMALLOC (struct inferior_thread_state); 5433 struct thread_info *tp = inferior_thread (); 5434 5435 inf_state->stop_signal = tp->stop_signal; 5436 inf_state->stop_pc = stop_pc; 5437 5438 inf_state->registers = regcache_dup (get_current_regcache ()); 5439 5440 return inf_state; 5441 } 5442 5443 /* Restore inferior session state to INF_STATE. */ 5444 5445 void 5446 restore_inferior_thread_state (struct inferior_thread_state *inf_state) 5447 { 5448 struct thread_info *tp = inferior_thread (); 5449 5450 tp->stop_signal = inf_state->stop_signal; 5451 stop_pc = inf_state->stop_pc; 5452 5453 /* The inferior can be gone if the user types "print exit(0)" 5454 (and perhaps other times). */ 5455 if (target_has_execution) 5456 /* NB: The register write goes through to the target. */ 5457 regcache_cpy (get_current_regcache (), inf_state->registers); 5458 regcache_xfree (inf_state->registers); 5459 xfree (inf_state); 5460 } 5461 5462 static void 5463 do_restore_inferior_thread_state_cleanup (void *state) 5464 { 5465 restore_inferior_thread_state (state); 5466 } 5467 5468 struct cleanup * 5469 make_cleanup_restore_inferior_thread_state (struct inferior_thread_state *inf_state) 5470 { 5471 return make_cleanup (do_restore_inferior_thread_state_cleanup, inf_state); 5472 } 5473 5474 void 5475 discard_inferior_thread_state (struct inferior_thread_state *inf_state) 5476 { 5477 regcache_xfree (inf_state->registers); 5478 xfree (inf_state); 5479 } 5480 5481 struct regcache * 5482 get_inferior_thread_state_regcache (struct inferior_thread_state *inf_state) 5483 { 5484 return inf_state->registers; 5485 } 5486 5487 /* Session related state for inferior function calls. 5488 These are the additional bits of state that need to be restored 5489 when an inferior function call successfully completes. */ 5490 5491 struct inferior_status 5492 { 5493 bpstat stop_bpstat; 5494 int stop_step; 5495 int stop_stack_dummy; 5496 int stopped_by_random_signal; 5497 int stepping_over_breakpoint; 5498 CORE_ADDR step_range_start; 5499 CORE_ADDR step_range_end; 5500 struct frame_id step_frame_id; 5501 struct frame_id step_stack_frame_id; 5502 enum step_over_calls_kind step_over_calls; 5503 CORE_ADDR step_resume_break_address; 5504 int stop_after_trap; 5505 int stop_soon; 5506 5507 /* ID if the selected frame when the inferior function call was made. */ 5508 struct frame_id selected_frame_id; 5509 5510 int proceed_to_finish; 5511 int in_infcall; 5512 }; 5513 5514 /* Save all of the information associated with the inferior<==>gdb 5515 connection. */ 5516 5517 struct inferior_status * 5518 save_inferior_status (void) 5519 { 5520 struct inferior_status *inf_status = XMALLOC (struct inferior_status); 5521 struct thread_info *tp = inferior_thread (); 5522 struct inferior *inf = current_inferior (); 5523 5524 inf_status->stop_step = tp->stop_step; 5525 inf_status->stop_stack_dummy = stop_stack_dummy; 5526 inf_status->stopped_by_random_signal = stopped_by_random_signal; 5527 inf_status->stepping_over_breakpoint = tp->trap_expected; 5528 inf_status->step_range_start = tp->step_range_start; 5529 inf_status->step_range_end = tp->step_range_end; 5530 inf_status->step_frame_id = tp->step_frame_id; 5531 inf_status->step_stack_frame_id = tp->step_stack_frame_id; 5532 inf_status->step_over_calls = tp->step_over_calls; 5533 inf_status->stop_after_trap = stop_after_trap; 5534 inf_status->stop_soon = inf->stop_soon; 5535 /* Save original bpstat chain here; replace it with copy of chain. 5536 If caller's caller is walking the chain, they'll be happier if we 5537 hand them back the original chain when restore_inferior_status is 5538 called. */ 5539 inf_status->stop_bpstat = tp->stop_bpstat; 5540 tp->stop_bpstat = bpstat_copy (tp->stop_bpstat); 5541 inf_status->proceed_to_finish = tp->proceed_to_finish; 5542 inf_status->in_infcall = tp->in_infcall; 5543 5544 inf_status->selected_frame_id = get_frame_id (get_selected_frame (NULL)); 5545 5546 return inf_status; 5547 } 5548 5549 static int 5550 restore_selected_frame (void *args) 5551 { 5552 struct frame_id *fid = (struct frame_id *) args; 5553 struct frame_info *frame; 5554 5555 frame = frame_find_by_id (*fid); 5556 5557 /* If inf_status->selected_frame_id is NULL, there was no previously 5558 selected frame. */ 5559 if (frame == NULL) 5560 { 5561 warning (_("Unable to restore previously selected frame.")); 5562 return 0; 5563 } 5564 5565 select_frame (frame); 5566 5567 return (1); 5568 } 5569 5570 /* Restore inferior session state to INF_STATUS. */ 5571 5572 void 5573 restore_inferior_status (struct inferior_status *inf_status) 5574 { 5575 struct thread_info *tp = inferior_thread (); 5576 struct inferior *inf = current_inferior (); 5577 5578 tp->stop_step = inf_status->stop_step; 5579 stop_stack_dummy = inf_status->stop_stack_dummy; 5580 stopped_by_random_signal = inf_status->stopped_by_random_signal; 5581 tp->trap_expected = inf_status->stepping_over_breakpoint; 5582 tp->step_range_start = inf_status->step_range_start; 5583 tp->step_range_end = inf_status->step_range_end; 5584 tp->step_frame_id = inf_status->step_frame_id; 5585 tp->step_stack_frame_id = inf_status->step_stack_frame_id; 5586 tp->step_over_calls = inf_status->step_over_calls; 5587 stop_after_trap = inf_status->stop_after_trap; 5588 inf->stop_soon = inf_status->stop_soon; 5589 bpstat_clear (&tp->stop_bpstat); 5590 tp->stop_bpstat = inf_status->stop_bpstat; 5591 inf_status->stop_bpstat = NULL; 5592 tp->proceed_to_finish = inf_status->proceed_to_finish; 5593 tp->in_infcall = inf_status->in_infcall; 5594 5595 if (target_has_stack) 5596 { 5597 /* The point of catch_errors is that if the stack is clobbered, 5598 walking the stack might encounter a garbage pointer and 5599 error() trying to dereference it. */ 5600 if (catch_errors 5601 (restore_selected_frame, &inf_status->selected_frame_id, 5602 "Unable to restore previously selected frame:\n", 5603 RETURN_MASK_ERROR) == 0) 5604 /* Error in restoring the selected frame. Select the innermost 5605 frame. */ 5606 select_frame (get_current_frame ()); 5607 } 5608 5609 xfree (inf_status); 5610 } 5611 5612 static void 5613 do_restore_inferior_status_cleanup (void *sts) 5614 { 5615 restore_inferior_status (sts); 5616 } 5617 5618 struct cleanup * 5619 make_cleanup_restore_inferior_status (struct inferior_status *inf_status) 5620 { 5621 return make_cleanup (do_restore_inferior_status_cleanup, inf_status); 5622 } 5623 5624 void 5625 discard_inferior_status (struct inferior_status *inf_status) 5626 { 5627 /* See save_inferior_status for info on stop_bpstat. */ 5628 bpstat_clear (&inf_status->stop_bpstat); 5629 xfree (inf_status); 5630 } 5631 5632 int 5633 inferior_has_forked (ptid_t pid, ptid_t *child_pid) 5634 { 5635 struct target_waitstatus last; 5636 ptid_t last_ptid; 5637 5638 get_last_target_status (&last_ptid, &last); 5639 5640 if (last.kind != TARGET_WAITKIND_FORKED) 5641 return 0; 5642 5643 if (!ptid_equal (last_ptid, pid)) 5644 return 0; 5645 5646 *child_pid = last.value.related_pid; 5647 return 1; 5648 } 5649 5650 int 5651 inferior_has_vforked (ptid_t pid, ptid_t *child_pid) 5652 { 5653 struct target_waitstatus last; 5654 ptid_t last_ptid; 5655 5656 get_last_target_status (&last_ptid, &last); 5657 5658 if (last.kind != TARGET_WAITKIND_VFORKED) 5659 return 0; 5660 5661 if (!ptid_equal (last_ptid, pid)) 5662 return 0; 5663 5664 *child_pid = last.value.related_pid; 5665 return 1; 5666 } 5667 5668 int 5669 inferior_has_execd (ptid_t pid, char **execd_pathname) 5670 { 5671 struct target_waitstatus last; 5672 ptid_t last_ptid; 5673 5674 get_last_target_status (&last_ptid, &last); 5675 5676 if (last.kind != TARGET_WAITKIND_EXECD) 5677 return 0; 5678 5679 if (!ptid_equal (last_ptid, pid)) 5680 return 0; 5681 5682 *execd_pathname = xstrdup (last.value.execd_pathname); 5683 return 1; 5684 } 5685 5686 int 5687 inferior_has_called_syscall (ptid_t pid, int *syscall_number) 5688 { 5689 struct target_waitstatus last; 5690 ptid_t last_ptid; 5691 5692 get_last_target_status (&last_ptid, &last); 5693 5694 if (last.kind != TARGET_WAITKIND_SYSCALL_ENTRY && 5695 last.kind != TARGET_WAITKIND_SYSCALL_RETURN) 5696 return 0; 5697 5698 if (!ptid_equal (last_ptid, pid)) 5699 return 0; 5700 5701 *syscall_number = last.value.syscall_number; 5702 return 1; 5703 } 5704 5705 /* Oft used ptids */ 5706 ptid_t null_ptid; 5707 ptid_t minus_one_ptid; 5708 5709 /* Create a ptid given the necessary PID, LWP, and TID components. */ 5710 5711 ptid_t 5712 ptid_build (int pid, long lwp, long tid) 5713 { 5714 ptid_t ptid; 5715 5716 ptid.pid = pid; 5717 ptid.lwp = lwp; 5718 ptid.tid = tid; 5719 return ptid; 5720 } 5721 5722 /* Create a ptid from just a pid. */ 5723 5724 ptid_t 5725 pid_to_ptid (int pid) 5726 { 5727 return ptid_build (pid, 0, 0); 5728 } 5729 5730 /* Fetch the pid (process id) component from a ptid. */ 5731 5732 int 5733 ptid_get_pid (ptid_t ptid) 5734 { 5735 return ptid.pid; 5736 } 5737 5738 /* Fetch the lwp (lightweight process) component from a ptid. */ 5739 5740 long 5741 ptid_get_lwp (ptid_t ptid) 5742 { 5743 return ptid.lwp; 5744 } 5745 5746 /* Fetch the tid (thread id) component from a ptid. */ 5747 5748 long 5749 ptid_get_tid (ptid_t ptid) 5750 { 5751 return ptid.tid; 5752 } 5753 5754 /* ptid_equal() is used to test equality of two ptids. */ 5755 5756 int 5757 ptid_equal (ptid_t ptid1, ptid_t ptid2) 5758 { 5759 return (ptid1.pid == ptid2.pid && ptid1.lwp == ptid2.lwp 5760 && ptid1.tid == ptid2.tid); 5761 } 5762 5763 /* Returns true if PTID represents a process. */ 5764 5765 int 5766 ptid_is_pid (ptid_t ptid) 5767 { 5768 if (ptid_equal (minus_one_ptid, ptid)) 5769 return 0; 5770 if (ptid_equal (null_ptid, ptid)) 5771 return 0; 5772 5773 return (ptid_get_lwp (ptid) == 0 && ptid_get_tid (ptid) == 0); 5774 } 5775 5776 /* restore_inferior_ptid() will be used by the cleanup machinery 5777 to restore the inferior_ptid value saved in a call to 5778 save_inferior_ptid(). */ 5779 5780 static void 5781 restore_inferior_ptid (void *arg) 5782 { 5783 ptid_t *saved_ptid_ptr = arg; 5784 inferior_ptid = *saved_ptid_ptr; 5785 xfree (arg); 5786 } 5787 5788 /* Save the value of inferior_ptid so that it may be restored by a 5789 later call to do_cleanups(). Returns the struct cleanup pointer 5790 needed for later doing the cleanup. */ 5791 5792 struct cleanup * 5793 save_inferior_ptid (void) 5794 { 5795 ptid_t *saved_ptid_ptr; 5796 5797 saved_ptid_ptr = xmalloc (sizeof (ptid_t)); 5798 *saved_ptid_ptr = inferior_ptid; 5799 return make_cleanup (restore_inferior_ptid, saved_ptid_ptr); 5800 } 5801 5802 5803 /* User interface for reverse debugging: 5804 Set exec-direction / show exec-direction commands 5805 (returns error unless target implements to_set_exec_direction method). */ 5806 5807 enum exec_direction_kind execution_direction = EXEC_FORWARD; 5808 static const char exec_forward[] = "forward"; 5809 static const char exec_reverse[] = "reverse"; 5810 static const char *exec_direction = exec_forward; 5811 static const char *exec_direction_names[] = { 5812 exec_forward, 5813 exec_reverse, 5814 NULL 5815 }; 5816 5817 static void 5818 set_exec_direction_func (char *args, int from_tty, 5819 struct cmd_list_element *cmd) 5820 { 5821 if (target_can_execute_reverse) 5822 { 5823 if (!strcmp (exec_direction, exec_forward)) 5824 execution_direction = EXEC_FORWARD; 5825 else if (!strcmp (exec_direction, exec_reverse)) 5826 execution_direction = EXEC_REVERSE; 5827 } 5828 } 5829 5830 static void 5831 show_exec_direction_func (struct ui_file *out, int from_tty, 5832 struct cmd_list_element *cmd, const char *value) 5833 { 5834 switch (execution_direction) { 5835 case EXEC_FORWARD: 5836 fprintf_filtered (out, _("Forward.\n")); 5837 break; 5838 case EXEC_REVERSE: 5839 fprintf_filtered (out, _("Reverse.\n")); 5840 break; 5841 case EXEC_ERROR: 5842 default: 5843 fprintf_filtered (out, 5844 _("Forward (target `%s' does not support exec-direction).\n"), 5845 target_shortname); 5846 break; 5847 } 5848 } 5849 5850 /* User interface for non-stop mode. */ 5851 5852 int non_stop = 0; 5853 static int non_stop_1 = 0; 5854 5855 static void 5856 set_non_stop (char *args, int from_tty, 5857 struct cmd_list_element *c) 5858 { 5859 if (target_has_execution) 5860 { 5861 non_stop_1 = non_stop; 5862 error (_("Cannot change this setting while the inferior is running.")); 5863 } 5864 5865 non_stop = non_stop_1; 5866 } 5867 5868 static void 5869 show_non_stop (struct ui_file *file, int from_tty, 5870 struct cmd_list_element *c, const char *value) 5871 { 5872 fprintf_filtered (file, 5873 _("Controlling the inferior in non-stop mode is %s.\n"), 5874 value); 5875 } 5876 5877 static void 5878 show_schedule_multiple (struct ui_file *file, int from_tty, 5879 struct cmd_list_element *c, const char *value) 5880 { 5881 fprintf_filtered (file, _("\ 5882 Resuming the execution of threads of all processes is %s.\n"), value); 5883 } 5884 5885 void 5886 _initialize_infrun (void) 5887 { 5888 int i; 5889 int numsigs; 5890 struct cmd_list_element *c; 5891 5892 add_info ("signals", signals_info, _("\ 5893 What debugger does when program gets various signals.\n\ 5894 Specify a signal as argument to print info on that signal only.")); 5895 add_info_alias ("handle", "signals", 0); 5896 5897 add_com ("handle", class_run, handle_command, _("\ 5898 Specify how to handle a signal.\n\ 5899 Args are signals and actions to apply to those signals.\n\ 5900 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\ 5901 from 1-15 are allowed for compatibility with old versions of GDB.\n\ 5902 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\ 5903 The special arg \"all\" is recognized to mean all signals except those\n\ 5904 used by the debugger, typically SIGTRAP and SIGINT.\n\ 5905 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\ 5906 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\ 5907 Stop means reenter debugger if this signal happens (implies print).\n\ 5908 Print means print a message if this signal happens.\n\ 5909 Pass means let program see this signal; otherwise program doesn't know.\n\ 5910 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\ 5911 Pass and Stop may be combined.")); 5912 if (xdb_commands) 5913 { 5914 add_com ("lz", class_info, signals_info, _("\ 5915 What debugger does when program gets various signals.\n\ 5916 Specify a signal as argument to print info on that signal only.")); 5917 add_com ("z", class_run, xdb_handle_command, _("\ 5918 Specify how to handle a signal.\n\ 5919 Args are signals and actions to apply to those signals.\n\ 5920 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\ 5921 from 1-15 are allowed for compatibility with old versions of GDB.\n\ 5922 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\ 5923 The special arg \"all\" is recognized to mean all signals except those\n\ 5924 used by the debugger, typically SIGTRAP and SIGINT.\n\ 5925 Recognized actions include \"s\" (toggles between stop and nostop), \n\ 5926 \"r\" (toggles between print and noprint), \"i\" (toggles between pass and \ 5927 nopass), \"Q\" (noprint)\n\ 5928 Stop means reenter debugger if this signal happens (implies print).\n\ 5929 Print means print a message if this signal happens.\n\ 5930 Pass means let program see this signal; otherwise program doesn't know.\n\ 5931 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\ 5932 Pass and Stop may be combined.")); 5933 } 5934 5935 if (!dbx_commands) 5936 stop_command = add_cmd ("stop", class_obscure, 5937 not_just_help_class_command, _("\ 5938 There is no `stop' command, but you can set a hook on `stop'.\n\ 5939 This allows you to set a list of commands to be run each time execution\n\ 5940 of the program stops."), &cmdlist); 5941 5942 add_setshow_zinteger_cmd ("infrun", class_maintenance, &debug_infrun, _("\ 5943 Set inferior debugging."), _("\ 5944 Show inferior debugging."), _("\ 5945 When non-zero, inferior specific debugging is enabled."), 5946 NULL, 5947 show_debug_infrun, 5948 &setdebuglist, &showdebuglist); 5949 5950 add_setshow_boolean_cmd ("displaced", class_maintenance, &debug_displaced, _("\ 5951 Set displaced stepping debugging."), _("\ 5952 Show displaced stepping debugging."), _("\ 5953 When non-zero, displaced stepping specific debugging is enabled."), 5954 NULL, 5955 show_debug_displaced, 5956 &setdebuglist, &showdebuglist); 5957 5958 add_setshow_boolean_cmd ("non-stop", no_class, 5959 &non_stop_1, _("\ 5960 Set whether gdb controls the inferior in non-stop mode."), _("\ 5961 Show whether gdb controls the inferior in non-stop mode."), _("\ 5962 When debugging a multi-threaded program and this setting is\n\ 5963 off (the default, also called all-stop mode), when one thread stops\n\ 5964 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\ 5965 all other threads in the program while you interact with the thread of\n\ 5966 interest. When you continue or step a thread, you can allow the other\n\ 5967 threads to run, or have them remain stopped, but while you inspect any\n\ 5968 thread's state, all threads stop.\n\ 5969 \n\ 5970 In non-stop mode, when one thread stops, other threads can continue\n\ 5971 to run freely. You'll be able to step each thread independently,\n\ 5972 leave it stopped or free to run as needed."), 5973 set_non_stop, 5974 show_non_stop, 5975 &setlist, 5976 &showlist); 5977 5978 numsigs = (int) TARGET_SIGNAL_LAST; 5979 signal_stop = (unsigned char *) xmalloc (sizeof (signal_stop[0]) * numsigs); 5980 signal_print = (unsigned char *) 5981 xmalloc (sizeof (signal_print[0]) * numsigs); 5982 signal_program = (unsigned char *) 5983 xmalloc (sizeof (signal_program[0]) * numsigs); 5984 for (i = 0; i < numsigs; i++) 5985 { 5986 signal_stop[i] = 1; 5987 signal_print[i] = 1; 5988 signal_program[i] = 1; 5989 } 5990 5991 /* Signals caused by debugger's own actions 5992 should not be given to the program afterwards. */ 5993 signal_program[TARGET_SIGNAL_TRAP] = 0; 5994 signal_program[TARGET_SIGNAL_INT] = 0; 5995 5996 /* Signals that are not errors should not normally enter the debugger. */ 5997 signal_stop[TARGET_SIGNAL_ALRM] = 0; 5998 signal_print[TARGET_SIGNAL_ALRM] = 0; 5999 signal_stop[TARGET_SIGNAL_VTALRM] = 0; 6000 signal_print[TARGET_SIGNAL_VTALRM] = 0; 6001 signal_stop[TARGET_SIGNAL_PROF] = 0; 6002 signal_print[TARGET_SIGNAL_PROF] = 0; 6003 signal_stop[TARGET_SIGNAL_CHLD] = 0; 6004 signal_print[TARGET_SIGNAL_CHLD] = 0; 6005 signal_stop[TARGET_SIGNAL_IO] = 0; 6006 signal_print[TARGET_SIGNAL_IO] = 0; 6007 signal_stop[TARGET_SIGNAL_POLL] = 0; 6008 signal_print[TARGET_SIGNAL_POLL] = 0; 6009 signal_stop[TARGET_SIGNAL_URG] = 0; 6010 signal_print[TARGET_SIGNAL_URG] = 0; 6011 signal_stop[TARGET_SIGNAL_WINCH] = 0; 6012 signal_print[TARGET_SIGNAL_WINCH] = 0; 6013 6014 /* These signals are used internally by user-level thread 6015 implementations. (See signal(5) on Solaris.) Like the above 6016 signals, a healthy program receives and handles them as part of 6017 its normal operation. */ 6018 signal_stop[TARGET_SIGNAL_LWP] = 0; 6019 signal_print[TARGET_SIGNAL_LWP] = 0; 6020 signal_stop[TARGET_SIGNAL_WAITING] = 0; 6021 signal_print[TARGET_SIGNAL_WAITING] = 0; 6022 signal_stop[TARGET_SIGNAL_CANCEL] = 0; 6023 signal_print[TARGET_SIGNAL_CANCEL] = 0; 6024 6025 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support, 6026 &stop_on_solib_events, _("\ 6027 Set stopping for shared library events."), _("\ 6028 Show stopping for shared library events."), _("\ 6029 If nonzero, gdb will give control to the user when the dynamic linker\n\ 6030 notifies gdb of shared library events. The most common event of interest\n\ 6031 to the user would be loading/unloading of a new library."), 6032 NULL, 6033 show_stop_on_solib_events, 6034 &setlist, &showlist); 6035 6036 add_setshow_enum_cmd ("follow-fork-mode", class_run, 6037 follow_fork_mode_kind_names, 6038 &follow_fork_mode_string, _("\ 6039 Set debugger response to a program call of fork or vfork."), _("\ 6040 Show debugger response to a program call of fork or vfork."), _("\ 6041 A fork or vfork creates a new process. follow-fork-mode can be:\n\ 6042 parent - the original process is debugged after a fork\n\ 6043 child - the new process is debugged after a fork\n\ 6044 The unfollowed process will continue to run.\n\ 6045 By default, the debugger will follow the parent process."), 6046 NULL, 6047 show_follow_fork_mode_string, 6048 &setlist, &showlist); 6049 6050 add_setshow_enum_cmd ("scheduler-locking", class_run, 6051 scheduler_enums, &scheduler_mode, _("\ 6052 Set mode for locking scheduler during execution."), _("\ 6053 Show mode for locking scheduler during execution."), _("\ 6054 off == no locking (threads may preempt at any time)\n\ 6055 on == full locking (no thread except the current thread may run)\n\ 6056 step == scheduler locked during every single-step operation.\n\ 6057 In this mode, no other thread may run during a step command.\n\ 6058 Other threads may run while stepping over a function call ('next')."), 6059 set_schedlock_func, /* traps on target vector */ 6060 show_scheduler_mode, 6061 &setlist, &showlist); 6062 6063 add_setshow_boolean_cmd ("schedule-multiple", class_run, &sched_multi, _("\ 6064 Set mode for resuming threads of all processes."), _("\ 6065 Show mode for resuming threads of all processes."), _("\ 6066 When on, execution commands (such as 'continue' or 'next') resume all\n\ 6067 threads of all processes. When off (which is the default), execution\n\ 6068 commands only resume the threads of the current process. The set of\n\ 6069 threads that are resumed is further refined by the scheduler-locking\n\ 6070 mode (see help set scheduler-locking)."), 6071 NULL, 6072 show_schedule_multiple, 6073 &setlist, &showlist); 6074 6075 add_setshow_boolean_cmd ("step-mode", class_run, &step_stop_if_no_debug, _("\ 6076 Set mode of the step operation."), _("\ 6077 Show mode of the step operation."), _("\ 6078 When set, doing a step over a function without debug line information\n\ 6079 will stop at the first instruction of that function. Otherwise, the\n\ 6080 function is skipped and the step command stops at a different source line."), 6081 NULL, 6082 show_step_stop_if_no_debug, 6083 &setlist, &showlist); 6084 6085 add_setshow_enum_cmd ("displaced-stepping", class_run, 6086 can_use_displaced_stepping_enum, 6087 &can_use_displaced_stepping, _("\ 6088 Set debugger's willingness to use displaced stepping."), _("\ 6089 Show debugger's willingness to use displaced stepping."), _("\ 6090 If on, gdb will use displaced stepping to step over breakpoints if it is\n\ 6091 supported by the target architecture. If off, gdb will not use displaced\n\ 6092 stepping to step over breakpoints, even if such is supported by the target\n\ 6093 architecture. If auto (which is the default), gdb will use displaced stepping\n\ 6094 if the target architecture supports it and non-stop mode is active, but will not\n\ 6095 use it in all-stop mode (see help set non-stop)."), 6096 NULL, 6097 show_can_use_displaced_stepping, 6098 &setlist, &showlist); 6099 6100 add_setshow_enum_cmd ("exec-direction", class_run, exec_direction_names, 6101 &exec_direction, _("Set direction of execution.\n\ 6102 Options are 'forward' or 'reverse'."), 6103 _("Show direction of execution (forward/reverse)."), 6104 _("Tells gdb whether to execute forward or backward."), 6105 set_exec_direction_func, show_exec_direction_func, 6106 &setlist, &showlist); 6107 6108 /* ptid initializations */ 6109 null_ptid = ptid_build (0, 0, 0); 6110 minus_one_ptid = ptid_build (-1, 0, 0); 6111 inferior_ptid = null_ptid; 6112 target_last_wait_ptid = minus_one_ptid; 6113 displaced_step_ptid = null_ptid; 6114 6115 observer_attach_thread_ptid_changed (infrun_thread_ptid_changed); 6116 observer_attach_thread_stop_requested (infrun_thread_stop_requested); 6117 observer_attach_thread_exit (infrun_thread_thread_exit); 6118 6119 /* Explicitly create without lookup, since that tries to create a 6120 value with a void typed value, and when we get here, gdbarch 6121 isn't initialized yet. At this point, we're quite sure there 6122 isn't another convenience variable of the same name. */ 6123 create_internalvar_type_lazy ("_siginfo", siginfo_make_value); 6124 } 6125