1 /* Data structures associated with breakpoints in GDB.
2 Copyright 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000
3 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software
19 Foundation, Inc., 59 Temple Place - Suite 330,
20 Boston, MA 02111-1307, USA. */
22 #if !defined (BREAKPOINT_H)
23 #define BREAKPOINT_H 1
28 #include "gdb-events.h"
32 /* This is the maximum number of bytes a breakpoint instruction can take.
33 Feel free to increase it. It's just used in a few places to size
34 arrays that should be independent of the target architecture. */
36 #define BREAKPOINT_MAX 16
38 /* Type of breakpoint. */
39 /* FIXME In the future, we should fold all other breakpoint-like things into
42 * single-step (for machines where we have to simulate single stepping)
43 (probably, though perhaps it is better for it to look as much as
44 possible like a single-step to wait_for_inferior). */
48 bp_none = 0, /* Eventpoint has been deleted. */
49 bp_breakpoint, /* Normal breakpoint */
50 bp_hardware_breakpoint, /* Hardware assisted breakpoint */
51 bp_until, /* used by until command */
52 bp_finish, /* used by finish command */
53 bp_watchpoint, /* Watchpoint */
54 bp_hardware_watchpoint, /* Hardware assisted watchpoint */
55 bp_read_watchpoint, /* read watchpoint, (hardware assisted) */
56 bp_access_watchpoint, /* access watchpoint, (hardware assisted) */
57 bp_longjmp, /* secret breakpoint to find longjmp() */
58 bp_longjmp_resume, /* secret breakpoint to escape longjmp() */
60 /* Used by wait_for_inferior for stepping over subroutine calls, for
61 stepping over signal handlers, and for skipping prologues. */
64 /* Used by wait_for_inferior for stepping over signal handlers. */
67 /* Used to detect when a watchpoint expression has gone out of
68 scope. These breakpoints are usually not visible to the user.
70 This breakpoint has some interesting properties:
72 1) There's always a 1:1 mapping between watchpoints
73 on local variables and watchpoint_scope breakpoints.
75 2) It automatically deletes itself and the watchpoint it's
76 associated with when hit.
78 3) It can never be disabled. */
81 /* The breakpoint at the end of a call dummy. */
82 /* FIXME: What if the function we are calling longjmp()s out of the
83 call, or the user gets out with the "return" command? We currently
84 have no way of cleaning up the breakpoint in these (obscure) situations.
85 (Probably can solve this by noticing longjmp, "return", etc., it's
86 similar to noticing when a watchpoint on a local variable goes out
87 of scope (with hardware support for watchpoints)). */
90 /* Some dynamic linkers (HP, maybe Solaris) can arrange for special
91 code in the inferior to run when significant events occur in the
92 dynamic linker (for example a library is loaded or unloaded).
94 By placing a breakpoint in this magic code GDB will get control
95 when these significant events occur. GDB can then re-examine
96 the dynamic linker's data structures to discover any newly loaded
100 /* Some multi-threaded systems can arrange for a location in the
101 inferior to be executed when certain thread-related events occur
102 (such as thread creation or thread death).
104 By placing a breakpoint at one of these locations, GDB will get
105 control when these events occur. GDB can then update its thread
110 /* On the same principal, an overlay manager can arrange to call a
111 magic location in the inferior whenever there is an interesting
112 change in overlay status. GDB can update its overlay tables
113 and fiddle with breakpoints in overlays when this breakpoint
118 /* These breakpoints are used to implement the "catch load" command
119 on platforms whose dynamic linkers support such functionality. */
122 /* These breakpoints are used to implement the "catch unload" command
123 on platforms whose dynamic linkers support such functionality. */
126 /* These are not really breakpoints, but are catchpoints that
127 implement the "catch fork", "catch vfork" and "catch exec" commands
128 on platforms whose kernel support such functionality. (I.e.,
129 kernels which can raise an event when a fork or exec occurs, as
130 opposed to the debugger setting breakpoints on functions named
131 "fork" or "exec".) */
136 /* These are catchpoints to implement "catch catch" and "catch throw"
137 commands for C++ exception handling. */
144 /* States of enablement of breakpoint. */
148 bp_disabled, /* The eventpoint is inactive, and cannot trigger. */
149 bp_enabled, /* The eventpoint is active, and can trigger. */
150 bp_shlib_disabled, /* The eventpoint's address is in an unloaded solib.
151 The eventpoint will be automatically enabled
152 and reset when that solib is loaded. */
153 bp_call_disabled, /* The eventpoint has been disabled while a call
154 into the inferior is "in flight", because some
155 eventpoints interfere with the implementation of
156 a call on some targets. The eventpoint will be
157 automatically enabled and reset when the call
158 "lands" (either completes, or stops at another
160 bp_permanent /* There is a breakpoint instruction hard-wired into
161 the target's code. Don't try to write another
162 breakpoint instruction on top of it, or restore
163 its value. Step over it using the architecture's
168 /* Disposition of breakpoint. Ie: what to do after hitting it. */
172 disp_del, /* Delete it */
173 disp_del_at_next_stop, /* Delete at next stop, whether hit or not */
174 disp_disable, /* Disable it */
175 disp_donttouch /* Leave it alone */
178 enum target_hw_bp_type
180 hw_write = 0, /* Common HW watchpoint */
181 hw_read = 1, /* Read HW watchpoint */
182 hw_access = 2, /* Access HW watchpoint */
183 hw_execute = 3 /* Execute HW breakpoint */
186 /* Note that the ->silent field is not currently used by any commands
187 (though the code is in there if it was to be, and set_raw_breakpoint
188 does set it to 0). I implemented it because I thought it would be
189 useful for a hack I had to put in; I'm going to leave it in because
190 I can see how there might be times when it would indeed be useful */
192 /* This is for a breakpoint or a watchpoint. */
196 struct breakpoint *next;
197 /* Type of breakpoint. */
199 /* Zero means disabled; remember the info but don't break here. */
200 enum enable_state enable_state;
201 /* What to do with this breakpoint after we hit it. */
202 enum bpdisp disposition;
203 /* Number assigned to distinguish breakpoints. */
206 /* Address to break at.
207 Note that zero is a perfectly valid code address on some
208 platforms (for example, the mn10200 and mn10300 simulators).
209 NULL is not a special value for this field. */
212 /* Line number of this address. */
216 /* Source file name of this address. */
220 /* Non-zero means a silent breakpoint (don't print frame info
222 unsigned char silent;
223 /* Number of stops at this breakpoint that should
224 be continued automatically before really stopping. */
226 /* "Real" contents of byte where breakpoint has been inserted.
227 Valid only when breakpoints are in the program. Under the complete
228 control of the target insert_breakpoint and remove_breakpoint routines.
229 No other code should assume anything about the value(s) here. */
230 char shadow_contents[BREAKPOINT_MAX];
231 /* Nonzero if this breakpoint is now inserted. */
233 /* Nonzero if this is not the first breakpoint in the list
234 for the given address. */
236 /* Chain of command lines to execute when this breakpoint is hit. */
237 struct command_line *commands;
238 /* Stack depth (address of frame). If nonzero, break only if fp
241 /* Conditional. Break only if this expression's value is nonzero. */
242 struct expression *cond;
244 /* String we used to set the breakpoint (malloc'd). */
246 /* Language we used to set the breakpoint. */
247 enum language language;
248 /* Input radix we used to set the breakpoint. */
250 /* String form of the breakpoint condition (malloc'd), or NULL if there
253 /* String form of exp (malloc'd), or NULL if none. */
256 /* The expression we are watching, or NULL if not a watchpoint. */
257 struct expression *exp;
258 /* The largest block within which it is valid, or NULL if it is
259 valid anywhere (e.g. consists just of global symbols). */
260 struct block *exp_valid_block;
261 /* Value of the watchpoint the last time we checked it. */
264 /* Holds the value chain for a hardware watchpoint expression. */
265 struct value *val_chain;
267 /* Holds the address of the related watchpoint_scope breakpoint
268 when using watchpoints on local variables (might the concept
269 of a related breakpoint be useful elsewhere, if not just call
270 it the watchpoint_scope breakpoint or something like that. FIXME). */
271 struct breakpoint *related_breakpoint;
273 /* Holds the frame address which identifies the frame this watchpoint
274 should be evaluated in, or NULL if the watchpoint should be evaluated
275 on the outermost frame. */
276 CORE_ADDR watchpoint_frame;
278 /* Thread number for thread-specific breakpoint, or -1 if don't care */
281 /* Count of the number of times this breakpoint was taken, dumped
282 with the info, but not used for anything else. Useful for
283 seeing how many times you hit a break prior to the program
284 aborting, so you can back up to just before the abort. */
287 /* Filename of a dynamically-linked library (dll), used for
288 bp_catch_load and bp_catch_unload (malloc'd), or NULL if any
289 library is significant. */
292 /* Filename of a dll whose state change (e.g., load or unload)
293 triggered this catchpoint. This field is only valid immediately
294 after this catchpoint has triggered. */
295 char *triggered_dll_pathname;
297 /* Process id of a child process whose forking triggered this
298 catchpoint. This field is only valid immediately after this
299 catchpoint has triggered. */
300 int forked_inferior_pid;
302 /* Filename of a program whose exec triggered this catchpoint.
303 This field is only valid immediately after this catchpoint has
310 /* The following stuff is an abstract data type "bpstat" ("breakpoint
311 status"). This provides the ability to determine whether we have
312 stopped at a breakpoint, and what we should do about it. */
314 typedef struct bpstats *bpstat;
317 /* Clear a bpstat so that it says we are not at any breakpoint.
318 Also free any storage that is part of a bpstat. */
319 extern void bpstat_clear (bpstat *);
321 /* Return a copy of a bpstat. Like "bs1 = bs2" but all storage that
322 is part of the bpstat is copied as well. */
323 extern bpstat bpstat_copy (bpstat);
325 extern bpstat bpstat_stop_status (CORE_ADDR *, int);
327 /* This bpstat_what stuff tells wait_for_inferior what to do with a
328 breakpoint (a challenging task). */
330 enum bpstat_what_main_action
332 /* Perform various other tests; that is, this bpstat does not
333 say to perform any action (e.g. failed watchpoint and nothing
335 BPSTAT_WHAT_KEEP_CHECKING,
337 /* Rather than distinguish between noisy and silent stops here, it
338 might be cleaner to have bpstat_print make that decision (also
339 taking into account stop_print_frame and source_only). But the
340 implications are a bit scary (interaction with auto-displays, etc.),
341 so I won't try it. */
344 BPSTAT_WHAT_STOP_SILENT,
346 /* Stop and print. */
347 BPSTAT_WHAT_STOP_NOISY,
349 /* Remove breakpoints, single step once, then put them back in and
350 go back to what we were doing. It's possible that this should be
351 removed from the main_action and put into a separate field, to more
352 cleanly handle BPSTAT_WHAT_CLEAR_LONGJMP_RESUME_SINGLE. */
355 /* Set longjmp_resume breakpoint, remove all other breakpoints,
356 and continue. The "remove all other breakpoints" part is required
357 if we are also stepping over another breakpoint as well as doing
358 the longjmp handling. */
359 BPSTAT_WHAT_SET_LONGJMP_RESUME,
361 /* Clear longjmp_resume breakpoint, then handle as
362 BPSTAT_WHAT_KEEP_CHECKING. */
363 BPSTAT_WHAT_CLEAR_LONGJMP_RESUME,
365 /* Clear longjmp_resume breakpoint, then handle as BPSTAT_WHAT_SINGLE. */
366 BPSTAT_WHAT_CLEAR_LONGJMP_RESUME_SINGLE,
368 /* Clear step resume breakpoint, and keep checking. */
369 BPSTAT_WHAT_STEP_RESUME,
371 /* Clear through_sigtramp breakpoint, muck with trap_expected, and keep
373 BPSTAT_WHAT_THROUGH_SIGTRAMP,
375 /* Check the dynamic linker's data structures for new libraries, then
377 BPSTAT_WHAT_CHECK_SHLIBS,
379 /* Check the dynamic linker's data structures for new libraries, then
380 resume out of the dynamic linker's callback, stop and print. */
381 BPSTAT_WHAT_CHECK_SHLIBS_RESUME_FROM_HOOK,
383 /* This is just used to keep track of how many enums there are. */
389 enum bpstat_what_main_action main_action;
391 /* Did we hit a call dummy breakpoint? This only goes with a main_action
392 of BPSTAT_WHAT_STOP_SILENT or BPSTAT_WHAT_STOP_NOISY (the concept of
393 continuing from a call dummy without popping the frame is not a
398 /* The possible return values for print_bpstat, print_it_normal,
399 print_it_done, print_it_noop. */
400 enum print_stop_action
408 /* Tell what to do about this bpstat. */
409 struct bpstat_what bpstat_what (bpstat);
411 /* Find the bpstat associated with a breakpoint. NULL otherwise. */
412 bpstat bpstat_find_breakpoint (bpstat, struct breakpoint *);
414 /* Find a step_resume breakpoint associated with this bpstat.
415 (If there are multiple step_resume bp's on the list, this function
416 will arbitrarily pick one.)
418 It is an error to use this function if BPSTAT doesn't contain a
419 step_resume breakpoint.
421 See wait_for_inferior's use of this function.
423 extern struct breakpoint *bpstat_find_step_resume_breakpoint (bpstat);
425 /* Nonzero if a signal that we got in wait() was due to circumstances
426 explained by the BS. */
427 /* Currently that is true if we have hit a breakpoint, or if there is
428 a watchpoint enabled. */
429 #define bpstat_explains_signal(bs) ((bs) != NULL)
431 /* Nonzero if we should step constantly (e.g. watchpoints on machines
432 without hardware support). This isn't related to a specific bpstat,
433 just to things like whether watchpoints are set. */
434 extern int bpstat_should_step (void);
436 /* Nonzero if there are enabled hardware watchpoints. */
437 extern int bpstat_have_active_hw_watchpoints (void);
439 /* Print a message indicating what happened. Returns nonzero to
440 say that only the source line should be printed after this (zero
441 return means print the frame as well as the source line). */
442 extern enum print_stop_action bpstat_print (bpstat);
444 /* Return the breakpoint number of the first breakpoint we are stopped
445 at. *BSP upon return is a bpstat which points to the remaining
446 breakpoints stopped at (but which is not guaranteed to be good for
447 anything but further calls to bpstat_num).
448 Return 0 if passed a bpstat which does not indicate any breakpoints. */
449 extern int bpstat_num (bpstat *);
451 /* Perform actions associated with having stopped at *BSP. Actually, we just
452 use this for breakpoint commands. Perhaps other actions will go here
453 later, but this is executed at a late time (from the command loop). */
454 extern void bpstat_do_actions (bpstat *);
456 /* Modify BS so that the actions will not be performed. */
457 extern void bpstat_clear_actions (bpstat);
459 /* Given a bpstat that records zero or more triggered eventpoints, this
460 function returns another bpstat which contains only the catchpoints
461 on that first list, if any.
463 extern void bpstat_get_triggered_catchpoints (bpstat, bpstat *);
465 /* Implementation: */
467 /* Values used to tell the printing routine how to behave for this bpstat. */
470 /* This is used when we want to do a normal printing of the reason
471 for stopping. The output will depend on the type of eventpoint
472 we are dealing with. This is the default value, most commonly
475 /* This is used when nothing should be printed for this bpstat entry. */
477 /* This is used when everything which needs to be printed has
478 already been printed. But we still want to print the frame. */
484 /* Linked list because there can be two breakpoints at the same
485 place, and a bpstat reflects the fact that both have been hit. */
487 /* Breakpoint that we are at. */
488 struct breakpoint *breakpoint_at;
489 /* Commands left to be done. */
490 struct command_line *commands;
491 /* Old value associated with a watchpoint. */
492 struct value *old_val;
494 /* Nonzero if this breakpoint tells us to print the frame. */
497 /* Nonzero if this breakpoint tells us to stop. */
500 /* Tell bpstat_print and print_bp_stop_message how to print stuff
501 associated with this element of the bpstat chain. */
502 enum bp_print_how print_it;
512 /* The possible return values for breakpoint_here_p.
513 We guarantee that zero always means "no breakpoint here". */
516 no_breakpoint_here = 0,
517 ordinary_breakpoint_here,
518 permanent_breakpoint_here
522 /* Prototypes for breakpoint-related functions. */
524 /* Forward declarations for prototypes */
527 extern enum breakpoint_here breakpoint_here_p (CORE_ADDR);
529 extern int breakpoint_inserted_here_p (CORE_ADDR);
531 extern int frame_in_dummy (struct frame_info *);
533 extern int breakpoint_thread_match (CORE_ADDR, ptid_t);
535 extern void until_break_command (char *, int);
537 extern void breakpoint_re_set (void);
539 extern void breakpoint_re_set_thread (struct breakpoint *);
541 extern int ep_is_exception_catchpoint (struct breakpoint *);
543 extern struct breakpoint *set_momentary_breakpoint
544 (struct symtab_and_line, struct frame_info *, enum bptype);
546 extern void set_ignore_count (int, int, int);
548 extern void set_default_breakpoint (int, CORE_ADDR, struct symtab *, int);
550 extern void mark_breakpoints_out (void);
552 extern void breakpoint_init_inferior (enum inf_context);
554 extern struct cleanup *make_cleanup_delete_breakpoint (struct breakpoint *);
556 extern struct cleanup *make_exec_cleanup_delete_breakpoint (struct breakpoint *);
558 extern void delete_breakpoint (struct breakpoint *);
560 extern void breakpoint_auto_delete (bpstat);
562 extern void breakpoint_clear_ignore_counts (void);
564 extern void break_command (char *, int);
566 extern void hbreak_command_wrapper (char *, int);
567 extern void thbreak_command_wrapper (char *, int);
568 extern void rbreak_command_wrapper (char *, int);
569 extern void watch_command_wrapper (char *, int);
570 extern void awatch_command_wrapper (char *, int);
571 extern void rwatch_command_wrapper (char *, int);
572 extern void tbreak_command (char *, int);
574 extern int insert_breakpoints (void);
576 extern int remove_breakpoints (void);
578 /* This function can be used to physically insert eventpoints from the
579 specified traced inferior process, without modifying the breakpoint
580 package's state. This can be useful for those targets which support
581 following the processes of a fork() or vfork() system call, when both
582 of the resulting two processes are to be followed. */
583 extern int reattach_breakpoints (int);
585 /* This function can be used to update the breakpoint package's state
586 after an exec() system call has been executed.
588 This function causes the following:
590 - All eventpoints are marked "not inserted".
591 - All eventpoints with a symbolic address are reset such that
592 the symbolic address must be reevaluated before the eventpoints
594 - The solib breakpoints are explicitly removed from the breakpoint
596 - A step-resume breakpoint, if any, is explicitly removed from the
598 - All eventpoints without a symbolic address are removed from the
600 extern void update_breakpoints_after_exec (void);
602 /* This function can be used to physically remove hardware breakpoints
603 and watchpoints from the specified traced inferior process, without
604 modifying the breakpoint package's state. This can be useful for
605 those targets which support following the processes of a fork() or
606 vfork() system call, when one of the resulting two processes is to
607 be detached and allowed to run free.
609 It is an error to use this function on the process whose id is
611 extern int detach_breakpoints (int);
613 extern void enable_longjmp_breakpoint (void);
614 extern void disable_longjmp_breakpoint (void);
615 extern void enable_overlay_breakpoints (void);
616 extern void disable_overlay_breakpoints (void);
618 extern void set_longjmp_resume_breakpoint (CORE_ADDR, struct frame_info *);
619 /* These functions respectively disable or reenable all currently
620 enabled watchpoints. When disabled, the watchpoints are marked
621 call_disabled. When reenabled, they are marked enabled.
623 The intended client of these functions is infcmd.c\run_stack_dummy.
625 The inferior must be stopped, and all breakpoints removed, when
626 these functions are used.
628 The need for these functions is that on some targets (e.g., HP-UX),
629 gdb is unable to unwind through the dummy frame that is pushed as
630 part of the implementation of a call command. Watchpoints can
631 cause the inferior to stop in places where this frame is visible,
632 and that can cause execution control to become very confused.
634 Note that if a user sets breakpoints in an interactively called
635 function, the call_disabled watchpoints will have been reenabled
636 when the first such breakpoint is reached. However, on targets
637 that are unable to unwind through the call dummy frame, watches
638 of stack-based storage may then be deleted, because gdb will
639 believe that their watched storage is out of scope. (Sigh.) */
640 extern void disable_watchpoints_before_interactive_call_start (void);
642 extern void enable_watchpoints_after_interactive_call_stop (void);
645 extern void clear_breakpoint_hit_counts (void);
647 extern int get_number (char **);
649 extern int get_number_or_range (char **);
651 /* The following are for displays, which aren't really breakpoints, but
652 here is as good a place as any for them. */
654 extern void disable_current_display (void);
656 extern void do_displays (void);
658 extern void disable_display (int);
660 extern void clear_displays (void);
662 extern void disable_breakpoint (struct breakpoint *);
664 extern void enable_breakpoint (struct breakpoint *);
666 extern void make_breakpoint_permanent (struct breakpoint *);
668 extern struct breakpoint *create_solib_event_breakpoint (CORE_ADDR);
670 extern struct breakpoint *create_thread_event_breakpoint (CORE_ADDR);
672 extern void remove_solib_event_breakpoints (void);
674 extern void remove_thread_event_breakpoints (void);
676 extern void disable_breakpoints_in_shlibs (int silent);
678 extern void re_enable_breakpoints_in_shlibs (void);
680 extern void create_solib_load_event_breakpoint (char *, int, char *, char *);
682 extern void create_solib_unload_event_breakpoint (char *, int,
685 extern void create_fork_event_catchpoint (int, char *);
687 extern void create_vfork_event_catchpoint (int, char *);
689 extern void create_exec_event_catchpoint (int, char *);
691 /* This function returns TRUE if ep is a catchpoint. */
692 extern int ep_is_catchpoint (struct breakpoint *);
694 /* This function returns TRUE if ep is a catchpoint of a
695 shared library (aka dynamically-linked library) event,
696 such as a library load or unload. */
697 extern int ep_is_shlib_catchpoint (struct breakpoint *);
699 extern struct breakpoint *set_breakpoint_sal (struct symtab_and_line);
701 /* Enable breakpoints and delete when hit. Called with ARG == NULL
702 deletes all breakpoints. */
703 extern void delete_command (char *arg, int from_tty);
705 /* Pull all H/W watchpoints from the target. Return non-zero if the
707 extern int remove_hw_watchpoints (void);
709 #endif /* !defined (BREAKPOINT_H) */