gdb/breakpoint.h

   1 /* Data structures associated with breakpoints in GDB.
   2    Copyright (C) 1992 Free Software Foundation, Inc.
   3
   4 This file is part of GDB.
   5
   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.
  10
  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.
  15
  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., 675 Mass Ave, Cambridge, MA 02139, USA.  */
  19
  20 #if !defined (BREAKPOINT_H)
  21 #define BREAKPOINT_H 1
  22
  23 #include "frame.h"
  24 #include "value.h"
  25
  26 /* This is the maximum number of bytes a breakpoint instruction can take.
  27    Feel free to increase it.  It's just used in a few places to size
  28    arrays that should be independent of the target architecture.  */
  29
  30 #define BREAKPOINT_MAX  16
  31 \f
  32 /* The follow stuff is an abstract data type "bpstat" ("breakpoint status").
  33    This provides the ability to determine whether we have stopped at a
  34    breakpoint, and what we should do about it.  */
  35
  36 typedef struct bpstat *bpstat;
  37
  38 /* Interface:  */
  39 /* Clear a bpstat so that it says we are not at any breakpoint.
  40    Also free any storage that is part of a bpstat.  */
  41 extern void bpstat_clear PARAMS ((bpstat *));
  42
  43 /* Return a copy of a bpstat.  Like "bs1 = bs2" but all storage that
  44    is part of the bpstat is copied as well.  */
  45 extern bpstat bpstat_copy PARAMS ((bpstat));
  46
  47 /* Get a bpstat associated with having just stopped at address *PC
  48    and frame address FRAME_ADDRESS.  Update *PC to point at the
  49    breakpoint (if we hit a breakpoint).  */
  50 /* FIXME:  prototypes uses equivalence between FRAME_ADDR and CORE_ADDR */
  51 extern bpstat bpstat_stop_status PARAMS ((CORE_ADDR *, CORE_ADDR));
  52
  53 /* Return values from bpstat_what.  */
  54 enum bpstat_what {
  55   /* Perform various other tests; that is, this bpstat does not
  56      say to perform any action (e.g. failed watchpoint and nothing
  57      else).  */
  58   BPSTAT_WHAT_KEEP_CHECKING,
  59
  60   /* Rather than distinguish between noisy and silent stops here, it
  61      might be cleaner to have bpstat_print make that decision (also
  62      taking into account stop_print_frame and source_only).  But the
  63      implications are a bit scary (interaction with auto-displays, etc.),
  64      so I won't try it.  */
  65
  66   /* Stop silently.  */
  67   BPSTAT_WHAT_STOP_SILENT,
  68
  69   /* Stop and print.  */
  70   BPSTAT_WHAT_STOP_NOISY,
  71
  72   /* Remove breakpoints, single step once, then put them back in and
  73      go back to what we were doing.  */
  74   BPSTAT_WHAT_SINGLE,
  75
  76   /* Set longjmp_resume breakpoint, remove all other breakpoints,
  77      and continue.  The "remove all other breakpoints" part is required
  78      if we are also stepping over another breakpoint as well as doing
  79      the longjmp handling.  */
  80   BPSTAT_WHAT_SET_LONGJMP_RESUME,
  81
  82   /* Clear longjmp_resume breakpoint, then handle as
  83      BPSTAT_WHAT_KEEP_CHECKING.  */
  84   BPSTAT_WHAT_CLEAR_LONGJMP_RESUME,
  85
  86   /* Clear longjmp_resume breakpoint, then handle as BPSTAT_WHAT_SINGLE.  */
  87   BPSTAT_WHAT_CLEAR_LONGJMP_RESUME_SINGLE,
  88
  89   /* This is just used to keep track of how many enums there are.  */
  90   BPSTAT_WHAT_LAST
  91 };
  92
  93 /* Tell what to do about this bpstat.  */
  94 enum bpstat_what bpstat_what PARAMS ((bpstat));
  95
  96 /* Find the bpstat associated with a breakpoint.  NULL otherwise. */
  97 bpstat bpstat_find_breakpoint PARAMS ((bpstat, struct breakpoint *));
  98
  99 /* Nonzero if a signal that we got in wait() was due to circumstances
 100    explained by the BS.  */
 101 /* Currently that is true if we have hit a breakpoint, or if there is
 102    a watchpoint enabled.  */
 103 #define bpstat_explains_signal(bs) ((bs) != NULL)
 104
 105 /* Nonzero if we should step constantly (e.g. watchpoints on machines
 106    without hardware support).  This isn't related to a specific bpstat,
 107    just to things like whether watchpoints are set.  */
 108 extern int bpstat_should_step PARAMS ((void));
 109
 110 /* Print a message indicating what happened.  Returns nonzero to
 111    say that only the source line should be printed after this (zero
 112    return means print the frame as well as the source line).  */
 113 extern int bpstat_print PARAMS ((bpstat));
 114
 115 /* Return the breakpoint number of the first breakpoint we are stopped
 116    at.  *BSP upon return is a bpstat which points to the remaining
 117    breakpoints stopped at (but which is not guaranteed to be good for
 118    anything but further calls to bpstat_num).
 119    Return 0 if passed a bpstat which does not indicate any breakpoints.  */
 120 extern int bpstat_num PARAMS ((bpstat *));
 121
 122 /* Perform actions associated with having stopped at *BSP.  */
 123 extern void bpstat_do_actions PARAMS ((bpstat *));
 124
 125 /* Modify BS so that the actions will not be performed.  */
 126 extern void bpstat_clear_actions PARAMS ((bpstat));
 127
 128 /* Implementation:  */
 129 struct bpstat
 130 {
 131   /* Linked list because there can be two breakpoints at the
 132      same place, and a bpstat reflects the fact that both have been hit.  */
 133   bpstat next;
 134   /* Breakpoint that we are at.  */
 135   struct breakpoint *breakpoint_at;
 136   /* Commands left to be done.  */
 137   struct command_line *commands;
 138   /* Old value associated with a watchpoint.  */
 139   value old_val;
 140
 141   /* Nonzero if this breakpoint tells us to print the frame.  */
 142   char print;
 143
 144   /* Nonzero if this breakpoint tells us to stop.  */
 145   char stop;
 146
 147   /* Function called by bpstat_print to print stuff associated with
 148      this element of the bpstat chain.  Returns 0 or 1 just like
 149      bpstat_print, or -1 if it can't deal with it.  */
 150   int (*print_it) PARAMS((bpstat bs));
 151 };
 152 \f
 153 /* Type of breakpoint. */
 154 /* FIXME In the future, we should fold all other breakpoint-like things into
 155    here.  This includes:
 156
 157    1) single-step (for machines where we have to simulate single stepping),
 158    2) step-resume (for 'next'ing over subroutine calls),
 159    3) call-dummy (the breakpoint at the end of a subroutine stub that gdb
 160       uses to call functions in the target).
 161
 162    I definately agree with (2) and (3); I'm not as sure about (1)
 163    (it is a low-level thing, perhaps the best thing is that it looks
 164    as much as possible like a single-step to wait_for_inferior)
 165    -kingdon, 8 Apr 93.
 166 */
 167
 168 enum bptype {
 169   bp_breakpoint,                /* Normal breakpoint */
 170   bp_until,                     /* used by until command */
 171   bp_finish,                    /* used by finish command */
 172   bp_watchpoint,                /* Watchpoint */
 173   bp_longjmp,                   /* secret breakpoint to find longjmp() */
 174   bp_longjmp_resume             /* secret breakpoint to escape longjmp() */
 175 };
 176
 177 /* States of enablement of breakpoint. */
 178
 179 enum enable { disabled, enabled};
 180
 181 /* Disposition of breakpoint.  Ie: what to do after hitting it. */
 182
 183 enum bpdisp {
 184   delete,                       /* Delete it */
 185   disable,                      /* Disable it */
 186   donttouch                     /* Leave it alone */
 187 };
 188
 189 /* Note that the ->silent field is not currently used by any commands
 190    (though the code is in there if it was to be, and set_raw_breakpoint
 191    does set it to 0).  I implemented it because I thought it would be
 192    useful for a hack I had to put in; I'm going to leave it in because
 193    I can see how there might be times when it would indeed be useful */
 194
 195 /* This is for a breakpoint or a watchpoint.  */
 196
 197 struct breakpoint
 198 {
 199   struct breakpoint *next;
 200   /* Type of breakpoint. */
 201   enum bptype type;
 202   /* Zero means disabled; remember the info but don't break here.  */
 203   enum enable enable;
 204   /* What to do with this breakpoint after we hit it. */
 205   enum bpdisp disposition;
 206   /* Number assigned to distinguish breakpoints.  */
 207   int number;
 208   /* Address to break at, or NULL if not a breakpoint.  */
 209   CORE_ADDR address;
 210   /* Line number of this address.  Redundant.  Only matters if address
 211      is non-NULL.  */
 212   int line_number;
 213   /* Symtab of file of this address.  Redundant.  Only matters if address
 214      is non-NULL.  */
 215   struct symtab *symtab;
 216   /* Non-zero means a silent breakpoint (don't print frame info
 217      if we stop here). */
 218   unsigned char silent;
 219   /* Number of stops at this breakpoint that should
 220      be continued automatically before really stopping.  */
 221   int ignore_count;
 222   /* "Real" contents of byte where breakpoint has been inserted.
 223      Valid only when breakpoints are in the program.  Under the complete
 224      control of the target insert_breakpoint and remove_breakpoint routines.
 225      No other code should assume anything about the value(s) here.  */
 226   char shadow_contents[BREAKPOINT_MAX];
 227   /* Nonzero if this breakpoint is now inserted.  Only matters if address
 228      is non-NULL.  */
 229   char inserted;
 230   /* Nonzero if this is not the first breakpoint in the list
 231      for the given address.  Only matters if address is non-NULL.  */
 232   char duplicate;
 233   /* Chain of command lines to execute when this breakpoint is hit.  */
 234   struct command_line *commands;
 235   /* Stack depth (address of frame).  If nonzero, break only if fp
 236      equals this.  */
 237   FRAME_ADDR frame;
 238   /* Conditional.  Break only if this expression's value is nonzero.  */
 239   struct expression *cond;
 240
 241   /* String we used to set the breakpoint (malloc'd).  Only matters if
 242      address is non-NULL.  */
 243   char *addr_string;
 244   /* String form of the breakpoint condition (malloc'd), or NULL if there
 245      is no condition.  */
 246   char *cond_string;
 247   /* String form of exp (malloc'd), or NULL if none.  */
 248   char *exp_string;
 249
 250   /* The expression we are watching, or NULL if not a watchpoint.  */
 251   struct expression *exp;
 252   /* The largest block within which it is valid, or NULL if it is
 253      valid anywhere (e.g. consists just of global symbols).  */
 254   struct block *exp_valid_block;
 255   /* Value of the watchpoint the last time we checked it.  */
 256   value val;
 257 };
 258 \f
 259 /* Prototypes for breakpoint-related functions.  */
 260
 261 #ifdef __STDC__         /* Forward declarations for prototypes */
 262 struct frame_info;
 263 #endif
 264
 265 extern int
 266 breakpoint_here_p PARAMS ((CORE_ADDR));
 267
 268 extern void
 269 until_break_command PARAMS ((char *, int));
 270
 271 extern void
 272 breakpoint_re_set PARAMS ((void));
 273
 274 extern void
 275 clear_momentary_breakpoints PARAMS ((void));
 276
 277 /* FIXME:  Prototype uses equivalence of "struct frame_info *" and FRAME */
 278 extern struct breakpoint *
 279 set_momentary_breakpoint PARAMS ((struct symtab_and_line,
 280                                   struct frame_info *,
 281                                   enum bptype));
 282
 283 extern void
 284 set_ignore_count PARAMS ((int, int, int));
 285
 286 extern void
 287 set_default_breakpoint PARAMS ((int, CORE_ADDR, struct symtab *, int));
 288
 289 extern void
 290 mark_breakpoints_out PARAMS ((void));
 291
 292 extern void
 293 delete_breakpoint PARAMS ((struct breakpoint *));
 294
 295 extern void
 296 breakpoint_auto_delete PARAMS ((bpstat));
 297
 298 extern void
 299 breakpoint_clear_ignore_counts PARAMS ((void));
 300
 301 extern void
 302 break_command PARAMS ((char *, int));
 303
 304 extern int
 305 insert_breakpoints PARAMS ((void));
 306
 307 extern int
 308 remove_breakpoints PARAMS ((void));
 309
 310 extern void
 311 enable_longjmp_breakpoint PARAMS ((void));
 312
 313 extern void
 314 disable_longjmp_breakpoint PARAMS ((void));
 315
 316 extern void
 317 set_longjmp_resume_breakpoint PARAMS ((CORE_ADDR, FRAME));
 318
 319 /* The following are for displays, which aren't really breakpoints, but
 320    here is as good a place as any for them.  */
 321
 322 extern void
 323 disable_current_display PARAMS ((void));
 324
 325 extern void
 326 do_displays PARAMS ((void));
 327
 328 extern void
 329 disable_display PARAMS ((int));
 330
 331 extern void
 332 clear_displays PARAMS ((void));
 333
 334 #endif /* !defined (BREAKPOINT_H) */