1 /* Data structures associated with breakpoints in GDB.
2 Copyright (C) 1992, 93, 94, 95, 96, 98, 1999 Free Software Foundation, Inc.
4 This file is part of GDB.
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA. */
21 #if !defined (BREAKPOINT_H)
22 #define BREAKPOINT_H 1
27 /* This is the maximum number of bytes a breakpoint instruction can take.
28 Feel free to increase it. It's just used in a few places to size
29 arrays that should be independent of the target architecture. */
31 #define BREAKPOINT_MAX 16
33 /* Type of breakpoint. */
34 /* FIXME In the future, we should fold all other breakpoint-like things into
37 * single-step (for machines where we have to simulate single stepping)
38 (probably, though perhaps it is better for it to look as much as
39 possible like a single-step to wait_for_inferior). */
43 bp_none = 0, /* Eventpoint has been deleted. */
44 bp_breakpoint, /* Normal breakpoint */
45 bp_hardware_breakpoint, /* Hardware assisted breakpoint */
46 bp_until, /* used by until command */
47 bp_finish, /* used by finish command */
48 bp_watchpoint, /* Watchpoint */
49 bp_hardware_watchpoint, /* Hardware assisted watchpoint */
50 bp_read_watchpoint, /* read watchpoint, (hardware assisted) */
51 bp_access_watchpoint, /* access watchpoint, (hardware assisted) */
52 bp_longjmp, /* secret breakpoint to find longjmp() */
53 bp_longjmp_resume, /* secret breakpoint to escape longjmp() */
55 /* Used by wait_for_inferior for stepping over subroutine calls, for
56 stepping over signal handlers, and for skipping prologues. */
59 /* Used by wait_for_inferior for stepping over signal handlers. */
62 /* Used to detect when a watchpoint expression has gone out of
63 scope. These breakpoints are usually not visible to the user.
65 This breakpoint has some interesting properties:
67 1) There's always a 1:1 mapping between watchpoints
68 on local variables and watchpoint_scope breakpoints.
70 2) It automatically deletes itself and the watchpoint it's
71 associated with when hit.
73 3) It can never be disabled. */
76 /* The breakpoint at the end of a call dummy. */
77 /* FIXME: What if the function we are calling longjmp()s out of the
78 call, or the user gets out with the "return" command? We currently
79 have no way of cleaning up the breakpoint in these (obscure) situations.
80 (Probably can solve this by noticing longjmp, "return", etc., it's
81 similar to noticing when a watchpoint on a local variable goes out
82 of scope (with hardware support for watchpoints)). */
85 /* Some dynamic linkers (HP, maybe Solaris) can arrange for special
86 code in the inferior to run when significant events occur in the
87 dynamic linker (for example a library is loaded or unloaded).
89 By placing a breakpoint in this magic code GDB will get control
90 when these significant events occur. GDB can then re-examine
91 the dynamic linker's data structures to discover any newly loaded
95 /* These breakpoints are used to implement the "catch load" command
96 on platforms whose dynamic linkers support such functionality. */
99 /* These breakpoints are used to implement the "catch unload" command
100 on platforms whose dynamic linkers support such functionality. */
103 /* These are not really breakpoints, but are catchpoints that
104 implement the "catch fork", "catch vfork" and "catch exec" commands
105 on platforms whose kernel support such functionality. (I.e.,
106 kernels which can raise an event when a fork or exec occurs, as
107 opposed to the debugger setting breakpoints on functions named
108 "fork" or "exec".) */
113 /* These are catchpoints to implement "catch catch" and "catch throw"
114 commands for C++ exception handling. */
121 /* States of enablement of breakpoint. */
125 disabled, /* The eventpoint is inactive, and cannot trigger. */
126 enabled, /* The eventpoint is active, and can trigger. */
127 shlib_disabled, /* The eventpoint's address is in an unloaded solib.
128 The eventpoint will be automatically enabled
129 and reset when that solib is loaded. */
130 call_disabled /* The eventpoint has been disabled while a call
131 into the inferior is "in flight", because some
132 eventpoints interfere with the implementation of
133 a call on some targets. The eventpoint will be
134 automatically enabled and reset when the call
135 "lands" (either completes, or stops at another
140 /* Disposition of breakpoint. Ie: what to do after hitting it. */
145 del_at_next_stop, /* Delete at next stop, whether hit or not */
146 disable, /* Disable it */
147 donttouch /* Leave it alone */
150 enum target_hw_bp_type
152 hw_write = 0, /* Common HW watchpoint */
153 hw_read = 1, /* Read HW watchpoint */
154 hw_access = 2, /* Access HW watchpoint */
155 hw_execute = 3 /* Execute HW breakpoint */
158 /* Note that the ->silent field is not currently used by any commands
159 (though the code is in there if it was to be, and set_raw_breakpoint
160 does set it to 0). I implemented it because I thought it would be
161 useful for a hack I had to put in; I'm going to leave it in because
162 I can see how there might be times when it would indeed be useful */
164 /* This is for a breakpoint or a watchpoint. */
168 struct breakpoint *next;
169 /* Type of breakpoint. */
171 /* Zero means disabled; remember the info but don't break here. */
173 /* What to do with this breakpoint after we hit it. */
174 enum bpdisp disposition;
175 /* Number assigned to distinguish breakpoints. */
178 /* Address to break at, or NULL if not a breakpoint. */
181 /* Line number of this address. Only matters if address is
186 /* Source file name of this address. Only matters if address is
191 /* Non-zero means a silent breakpoint (don't print frame info
193 unsigned char silent;
194 /* Number of stops at this breakpoint that should
195 be continued automatically before really stopping. */
197 /* "Real" contents of byte where breakpoint has been inserted.
198 Valid only when breakpoints are in the program. Under the complete
199 control of the target insert_breakpoint and remove_breakpoint routines.
200 No other code should assume anything about the value(s) here. */
201 char shadow_contents[BREAKPOINT_MAX];
202 /* Nonzero if this breakpoint is now inserted. Only matters if address
205 /* Nonzero if this is not the first breakpoint in the list
206 for the given address. Only matters if address is non-NULL. */
208 /* Chain of command lines to execute when this breakpoint is hit. */
209 struct command_line *commands;
210 /* Stack depth (address of frame). If nonzero, break only if fp
213 /* Conditional. Break only if this expression's value is nonzero. */
214 struct expression *cond;
216 /* String we used to set the breakpoint (malloc'd). Only matters if
217 address is non-NULL. */
219 /* Language we used to set the breakpoint. */
220 enum language language;
221 /* Input radix we used to set the breakpoint. */
223 /* String form of the breakpoint condition (malloc'd), or NULL if there
226 /* String form of exp (malloc'd), or NULL if none. */
229 /* The expression we are watching, or NULL if not a watchpoint. */
230 struct expression *exp;
231 /* The largest block within which it is valid, or NULL if it is
232 valid anywhere (e.g. consists just of global symbols). */
233 struct block *exp_valid_block;
234 /* Value of the watchpoint the last time we checked it. */
237 /* Holds the value chain for a hardware watchpoint expression. */
240 /* Holds the address of the related watchpoint_scope breakpoint
241 when using watchpoints on local variables (might the concept
242 of a related breakpoint be useful elsewhere, if not just call
243 it the watchpoint_scope breakpoint or something like that. FIXME). */
244 struct breakpoint *related_breakpoint;
246 /* Holds the frame address which identifies the frame this watchpoint
247 should be evaluated in, or NULL if the watchpoint should be evaluated
248 on the outermost frame. */
249 CORE_ADDR watchpoint_frame;
251 /* Thread number for thread-specific breakpoint, or -1 if don't care */
254 /* Count of the number of times this breakpoint was taken, dumped
255 with the info, but not used for anything else. Useful for
256 seeing how many times you hit a break prior to the program
257 aborting, so you can back up to just before the abort. */
260 /* Filename of a dynamically-linked library (dll), used for
261 bp_catch_load and bp_catch_unload (malloc'd), or NULL if any
262 library is significant. */
265 /* Filename of a dll whose state change (e.g., load or unload)
266 triggered this catchpoint. This field is only vaid immediately
267 after this catchpoint has triggered. */
268 char *triggered_dll_pathname;
270 /* Process id of a child process whose forking triggered this
271 catchpoint. This field is only vaid immediately after this
272 catchpoint has triggered. */
273 int forked_inferior_pid;
275 /* Filename of a program whose exec triggered this catchpoint.
276 This field is only vaid immediately after this catchpoint has
283 /* The following stuff is an abstract data type "bpstat" ("breakpoint
284 status"). This provides the ability to determine whether we have
285 stopped at a breakpoint, and what we should do about it. */
287 typedef struct bpstats *bpstat;
290 /* Clear a bpstat so that it says we are not at any breakpoint.
291 Also free any storage that is part of a bpstat. */
292 extern void bpstat_clear PARAMS ((bpstat *));
294 /* Return a copy of a bpstat. Like "bs1 = bs2" but all storage that
295 is part of the bpstat is copied as well. */
296 extern bpstat bpstat_copy PARAMS ((bpstat));
298 extern bpstat bpstat_stop_status PARAMS ((CORE_ADDR *, int));
300 /* This bpstat_what stuff tells wait_for_inferior what to do with a
301 breakpoint (a challenging task). */
303 enum bpstat_what_main_action
305 /* Perform various other tests; that is, this bpstat does not
306 say to perform any action (e.g. failed watchpoint and nothing
308 BPSTAT_WHAT_KEEP_CHECKING,
310 /* Rather than distinguish between noisy and silent stops here, it
311 might be cleaner to have bpstat_print make that decision (also
312 taking into account stop_print_frame and source_only). But the
313 implications are a bit scary (interaction with auto-displays, etc.),
314 so I won't try it. */
317 BPSTAT_WHAT_STOP_SILENT,
319 /* Stop and print. */
320 BPSTAT_WHAT_STOP_NOISY,
322 /* Remove breakpoints, single step once, then put them back in and
323 go back to what we were doing. It's possible that this should be
324 removed from the main_action and put into a separate field, to more
325 cleanly handle BPSTAT_WHAT_CLEAR_LONGJMP_RESUME_SINGLE. */
328 /* Set longjmp_resume breakpoint, remove all other breakpoints,
329 and continue. The "remove all other breakpoints" part is required
330 if we are also stepping over another breakpoint as well as doing
331 the longjmp handling. */
332 BPSTAT_WHAT_SET_LONGJMP_RESUME,
334 /* Clear longjmp_resume breakpoint, then handle as
335 BPSTAT_WHAT_KEEP_CHECKING. */
336 BPSTAT_WHAT_CLEAR_LONGJMP_RESUME,
338 /* Clear longjmp_resume breakpoint, then handle as BPSTAT_WHAT_SINGLE. */
339 BPSTAT_WHAT_CLEAR_LONGJMP_RESUME_SINGLE,
341 /* Clear step resume breakpoint, and keep checking. */
342 BPSTAT_WHAT_STEP_RESUME,
344 /* Clear through_sigtramp breakpoint, muck with trap_expected, and keep
346 BPSTAT_WHAT_THROUGH_SIGTRAMP,
348 /* Check the dynamic linker's data structures for new libraries, then
350 BPSTAT_WHAT_CHECK_SHLIBS,
352 /* Check the dynamic linker's data structures for new libraries, then
353 resume out of the dynamic linker's callback, stop and print. */
354 BPSTAT_WHAT_CHECK_SHLIBS_RESUME_FROM_HOOK,
356 /* This is just used to keep track of how many enums there are. */
362 enum bpstat_what_main_action main_action;
364 /* Did we hit a call dummy breakpoint? This only goes with a main_action
365 of BPSTAT_WHAT_STOP_SILENT or BPSTAT_WHAT_STOP_NOISY (the concept of
366 continuing from a call dummy without popping the frame is not a
371 /* Tell what to do about this bpstat. */
372 struct bpstat_what bpstat_what PARAMS ((bpstat));
374 /* Find the bpstat associated with a breakpoint. NULL otherwise. */
375 bpstat bpstat_find_breakpoint PARAMS ((bpstat, struct breakpoint *));
377 /* Find a step_resume breakpoint associated with this bpstat.
378 (If there are multiple step_resume bp's on the list, this function
379 will arbitrarily pick one.)
381 It is an error to use this function if BPSTAT doesn't contain a
382 step_resume breakpoint.
384 See wait_for_inferior's use of this function.
386 extern struct breakpoint *
387 bpstat_find_step_resume_breakpoint PARAMS ((bpstat));
389 /* Nonzero if a signal that we got in wait() was due to circumstances
390 explained by the BS. */
391 /* Currently that is true if we have hit a breakpoint, or if there is
392 a watchpoint enabled. */
393 #define bpstat_explains_signal(bs) ((bs) != NULL)
395 /* Nonzero if we should step constantly (e.g. watchpoints on machines
396 without hardware support). This isn't related to a specific bpstat,
397 just to things like whether watchpoints are set. */
398 extern int bpstat_should_step PARAMS ((void));
400 /* Nonzero if there are enabled hardware watchpoints. */
401 extern int bpstat_have_active_hw_watchpoints PARAMS ((void));
403 /* Print a message indicating what happened. Returns nonzero to
404 say that only the source line should be printed after this (zero
405 return means print the frame as well as the source line). */
406 extern int bpstat_print PARAMS ((bpstat));
408 /* Return the breakpoint number of the first breakpoint we are stopped
409 at. *BSP upon return is a bpstat which points to the remaining
410 breakpoints stopped at (but which is not guaranteed to be good for
411 anything but further calls to bpstat_num).
412 Return 0 if passed a bpstat which does not indicate any breakpoints. */
413 extern int bpstat_num PARAMS ((bpstat *));
415 /* Perform actions associated with having stopped at *BSP. Actually, we just
416 use this for breakpoint commands. Perhaps other actions will go here
417 later, but this is executed at a late time (from the command loop). */
418 extern void bpstat_do_actions PARAMS ((bpstat *));
420 /* Modify BS so that the actions will not be performed. */
421 extern void bpstat_clear_actions PARAMS ((bpstat));
423 /* Given a bpstat that records zero or more triggered eventpoints, this
424 function returns another bpstat which contains only the catchpoints
425 on that first list, if any.
427 extern void bpstat_get_triggered_catchpoints PARAMS ((bpstat, bpstat *));
429 /* Implementation: */
432 /* Linked list because there can be two breakpoints at the same
433 place, and a bpstat reflects the fact that both have been hit. */
435 /* Breakpoint that we are at. */
436 struct breakpoint *breakpoint_at;
437 /* Commands left to be done. */
438 struct command_line *commands;
439 /* Old value associated with a watchpoint. */
442 /* Nonzero if this breakpoint tells us to print the frame. */
445 /* Nonzero if this breakpoint tells us to stop. */
448 /* Function called by bpstat_print to print stuff associated with
449 this element of the bpstat chain. Returns 0 or 1 just like
450 bpstat_print, or -1 if it can't deal with it. */
451 int (*print_it) PARAMS ((bpstat bs));
462 /* Prototypes for breakpoint-related functions. */
464 #ifdef __STDC__ /* Forward declarations for prototypes */
468 extern int breakpoint_here_p PARAMS ((CORE_ADDR));
470 extern int breakpoint_inserted_here_p PARAMS ((CORE_ADDR));
472 extern int frame_in_dummy PARAMS ((struct frame_info *));
474 extern int breakpoint_thread_match PARAMS ((CORE_ADDR, int));
476 extern void until_break_command PARAMS ((char *, int));
478 extern void breakpoint_re_set PARAMS ((void));
480 extern void breakpoint_re_set_thread PARAMS ((struct breakpoint *));
482 extern int ep_is_exception_catchpoint PARAMS ((struct breakpoint *));
484 extern struct breakpoint *set_momentary_breakpoint
485 PARAMS ((struct symtab_and_line, struct frame_info *, enum bptype));
487 extern void set_ignore_count PARAMS ((int, int, int));
489 extern void set_default_breakpoint PARAMS ((int, CORE_ADDR,
490 struct symtab *, int));
492 extern void mark_breakpoints_out PARAMS ((void));
494 extern void breakpoint_init_inferior PARAMS ((enum inf_context));
496 extern void delete_breakpoint PARAMS ((struct breakpoint *));
498 extern void breakpoint_auto_delete PARAMS ((bpstat));
500 extern void breakpoint_clear_ignore_counts PARAMS ((void));
502 extern void break_command PARAMS ((char *, int));
504 extern void tbreak_command PARAMS ((char *, int));
506 extern int insert_breakpoints PARAMS ((void));
508 extern int remove_breakpoints PARAMS ((void));
510 /* This function can be used to physically insert eventpoints from the
511 specified traced inferior process, without modifying the breakpoint
512 package's state. This can be useful for those targets which support
513 following the processes of a fork() or vfork() system call, when both
514 of the resulting two processes are to be followed. */
515 extern int reattach_breakpoints PARAMS ((int));
517 /* This function can be used to update the breakpoint package's state
518 after an exec() system call has been executed.
520 This function causes the following:
522 - All eventpoints are marked "not inserted".
523 - All eventpoints with a symbolic address are reset such that
524 the symbolic address must be reevaluated before the eventpoints
526 - The solib breakpoints are explicitly removed from the breakpoint
528 - A step-resume breakpoint, if any, is explicitly removed from the
530 - All eventpoints without a symbolic address are removed from the
532 extern void update_breakpoints_after_exec PARAMS ((void));
534 /* This function can be used to physically remove hardware breakpoints
535 and watchpoints from the specified traced inferior process, without
536 modifying the breakpoint package's state. This can be useful for
537 those targets which support following the processes of a fork() or
538 vfork() system call, when one of the resulting two processes is to
539 be detached and allowed to run free.
541 It is an error to use this function on the process whose id is
543 extern int detach_breakpoints PARAMS ((int));
545 extern void enable_longjmp_breakpoint PARAMS ((void));
547 extern void disable_longjmp_breakpoint PARAMS ((void));
549 extern void set_longjmp_resume_breakpoint PARAMS ((CORE_ADDR,
550 struct frame_info *));
551 /* These functions respectively disable or reenable all currently
552 enabled watchpoints. When disabled, the watchpoints are marked
553 call_disabled. When reenabled, they are marked enabled.
555 The intended client of these functions is infcmd.c\run_stack_dummy.
557 The inferior must be stopped, and all breakpoints removed, when
558 these functions are used.
560 The need for these functions is that on some targets (e.g., HP-UX),
561 gdb is unable to unwind through the dummy frame that is pushed as
562 part of the implementation of a call command. Watchpoints can
563 cause the inferior to stop in places where this frame is visible,
564 and that can cause execution control to become very confused.
566 Note that if a user sets breakpoints in an interactively call
567 function, the call_disabled watchpoints will have been reenabled
568 when the first such breakpoint is reached. However, on targets
569 that are unable to unwind through the call dummy frame, watches
570 of stack-based storage may then be deleted, because gdb will
571 believe that their watched storage is out of scope. (Sigh.) */
573 disable_watchpoints_before_interactive_call_start PARAMS ((void));
576 enable_watchpoints_after_interactive_call_stop PARAMS ((void));
579 extern void clear_breakpoint_hit_counts PARAMS ((void));
581 /* The following are for displays, which aren't really breakpoints, but
582 here is as good a place as any for them. */
584 extern void disable_current_display PARAMS ((void));
586 extern void do_displays PARAMS ((void));
588 extern void disable_display PARAMS ((int));
590 extern void clear_displays PARAMS ((void));
592 extern void disable_breakpoint PARAMS ((struct breakpoint *));
594 extern void enable_breakpoint PARAMS ((struct breakpoint *));
596 extern void create_solib_event_breakpoint PARAMS ((CORE_ADDR));
598 extern void remove_solib_event_breakpoints PARAMS ((void));
600 extern void disable_breakpoints_in_shlibs PARAMS ((int silent));
602 extern void re_enable_breakpoints_in_shlibs PARAMS ((void));
604 extern void create_solib_load_event_breakpoint PARAMS ((char *, int,
607 extern void create_solib_unload_event_breakpoint PARAMS ((char *, int,
610 extern void create_fork_event_catchpoint PARAMS ((int, char *));
612 extern void create_vfork_event_catchpoint PARAMS ((int, char *));
614 extern void create_exec_event_catchpoint PARAMS ((int, char *));
616 /* This function returns TRUE if ep is a catchpoint. */
617 extern int ep_is_catchpoint PARAMS ((struct breakpoint *));
619 /* This function returns TRUE if ep is a catchpoint of a
620 shared library (aka dynamically-linked library) event,
621 such as a library load or unload. */
622 extern int ep_is_shlib_catchpoint PARAMS ((struct breakpoint *));
624 extern struct breakpoint *set_breakpoint_sal PARAMS ((struct symtab_and_line));
626 #endif /* !defined (BREAKPOINT_H) */