| 1 | /* Data structures associated with breakpoints in GDB. |
| 2 | Copyright (C) 1992, 1993, 1994, 1995, 1996 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, 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 | /* Type of breakpoint. */ |
| 33 | /* FIXME In the future, we should fold all other breakpoint-like things into |
| 34 | here. This includes: |
| 35 | |
| 36 | * single-step (for machines where we have to simulate single stepping) |
| 37 | (probably, though perhaps it is better for it to look as much as |
| 38 | possible like a single-step to wait_for_inferior). */ |
| 39 | |
| 40 | enum bptype { |
| 41 | bp_breakpoint, /* Normal breakpoint */ |
| 42 | bp_hardware_breakpoint, /* Hardware assisted breakpoint */ |
| 43 | bp_until, /* used by until command */ |
| 44 | bp_finish, /* used by finish command */ |
| 45 | bp_watchpoint, /* Watchpoint */ |
| 46 | bp_hardware_watchpoint, /* Hardware assisted watchpoint */ |
| 47 | bp_read_watchpoint, /* read watchpoint, (hardware assisted) */ |
| 48 | bp_access_watchpoint, /* access watchpoint, (hardware assisted) */ |
| 49 | bp_longjmp, /* secret breakpoint to find longjmp() */ |
| 50 | bp_longjmp_resume, /* secret breakpoint to escape longjmp() */ |
| 51 | |
| 52 | /* Used by wait_for_inferior for stepping over subroutine calls, for |
| 53 | stepping over signal handlers, and for skipping prologues. */ |
| 54 | bp_step_resume, |
| 55 | |
| 56 | /* Used by wait_for_inferior for stepping over signal handlers. */ |
| 57 | bp_through_sigtramp, |
| 58 | |
| 59 | /* Used to detect when a watchpoint expression has gone out of |
| 60 | scope. These breakpoints are usually not visible to the user. |
| 61 | |
| 62 | This breakpoint has some interesting properties: |
| 63 | |
| 64 | 1) There's always a 1:1 mapping between watchpoints |
| 65 | on local variables and watchpoint_scope breakpoints. |
| 66 | |
| 67 | 2) It automatically deletes itself and the watchpoint it's |
| 68 | associated with when hit. |
| 69 | |
| 70 | 3) It can never be disabled. */ |
| 71 | bp_watchpoint_scope, |
| 72 | |
| 73 | /* The breakpoint at the end of a call dummy. */ |
| 74 | /* FIXME: What if the function we are calling longjmp()s out of the |
| 75 | call, or the user gets out with the "return" command? We currently |
| 76 | have no way of cleaning up the breakpoint in these (obscure) situations. |
| 77 | (Probably can solve this by noticing longjmp, "return", etc., it's |
| 78 | similar to noticing when a watchpoint on a local variable goes out |
| 79 | of scope (with hardware support for watchpoints)). */ |
| 80 | bp_call_dummy, |
| 81 | |
| 82 | /* Some dynamic linkers (HP, maybe Solaris) can arrange for special |
| 83 | code in the inferior to run when significant events occur in the |
| 84 | dynamic linker (for example a library is loaded or unloaded). |
| 85 | |
| 86 | By placing a breakpoint in this magic code GDB will get control |
| 87 | when these significant events occur. GDB can then re-examine |
| 88 | the dynamic linker's data structures to discover any newly loaded |
| 89 | dynamic libraries. */ |
| 90 | bp_shlib_event |
| 91 | }; |
| 92 | |
| 93 | /* States of enablement of breakpoint. */ |
| 94 | |
| 95 | enum enable { disabled, enabled, shlib_disabled}; |
| 96 | |
| 97 | /* Disposition of breakpoint. Ie: what to do after hitting it. */ |
| 98 | |
| 99 | enum bpdisp { |
| 100 | del, /* Delete it */ |
| 101 | del_at_next_stop, /* Delete at next stop, whether hit or not */ |
| 102 | disable, /* Disable it */ |
| 103 | donttouch /* Leave it alone */ |
| 104 | }; |
| 105 | |
| 106 | /* Note that the ->silent field is not currently used by any commands |
| 107 | (though the code is in there if it was to be, and set_raw_breakpoint |
| 108 | does set it to 0). I implemented it because I thought it would be |
| 109 | useful for a hack I had to put in; I'm going to leave it in because |
| 110 | I can see how there might be times when it would indeed be useful */ |
| 111 | |
| 112 | /* This is for a breakpoint or a watchpoint. */ |
| 113 | |
| 114 | struct breakpoint |
| 115 | { |
| 116 | struct breakpoint *next; |
| 117 | /* Type of breakpoint. */ |
| 118 | enum bptype type; |
| 119 | /* Zero means disabled; remember the info but don't break here. */ |
| 120 | enum enable enable; |
| 121 | /* What to do with this breakpoint after we hit it. */ |
| 122 | enum bpdisp disposition; |
| 123 | /* Number assigned to distinguish breakpoints. */ |
| 124 | int number; |
| 125 | |
| 126 | /* Address to break at, or NULL if not a breakpoint. */ |
| 127 | CORE_ADDR address; |
| 128 | |
| 129 | /* Line number of this address. Only matters if address is |
| 130 | non-NULL. */ |
| 131 | |
| 132 | int line_number; |
| 133 | |
| 134 | /* Source file name of this address. Only matters if address is |
| 135 | non-NULL. */ |
| 136 | |
| 137 | char *source_file; |
| 138 | |
| 139 | /* Non-zero means a silent breakpoint (don't print frame info |
| 140 | if we stop here). */ |
| 141 | unsigned char silent; |
| 142 | /* Number of stops at this breakpoint that should |
| 143 | be continued automatically before really stopping. */ |
| 144 | int ignore_count; |
| 145 | /* "Real" contents of byte where breakpoint has been inserted. |
| 146 | Valid only when breakpoints are in the program. Under the complete |
| 147 | control of the target insert_breakpoint and remove_breakpoint routines. |
| 148 | No other code should assume anything about the value(s) here. */ |
| 149 | char shadow_contents[BREAKPOINT_MAX]; |
| 150 | /* Nonzero if this breakpoint is now inserted. Only matters if address |
| 151 | is non-NULL. */ |
| 152 | char inserted; |
| 153 | /* Nonzero if this is not the first breakpoint in the list |
| 154 | for the given address. Only matters if address is non-NULL. */ |
| 155 | char duplicate; |
| 156 | /* Chain of command lines to execute when this breakpoint is hit. */ |
| 157 | struct command_line *commands; |
| 158 | /* Stack depth (address of frame). If nonzero, break only if fp |
| 159 | equals this. */ |
| 160 | CORE_ADDR frame; |
| 161 | /* Conditional. Break only if this expression's value is nonzero. */ |
| 162 | struct expression *cond; |
| 163 | |
| 164 | /* String we used to set the breakpoint (malloc'd). Only matters if |
| 165 | address is non-NULL. */ |
| 166 | char *addr_string; |
| 167 | /* Language we used to set the breakpoint. */ |
| 168 | enum language language; |
| 169 | /* Input radix we used to set the breakpoint. */ |
| 170 | int input_radix; |
| 171 | /* String form of the breakpoint condition (malloc'd), or NULL if there |
| 172 | is no condition. */ |
| 173 | char *cond_string; |
| 174 | /* String form of exp (malloc'd), or NULL if none. */ |
| 175 | char *exp_string; |
| 176 | |
| 177 | /* The expression we are watching, or NULL if not a watchpoint. */ |
| 178 | struct expression *exp; |
| 179 | /* The largest block within which it is valid, or NULL if it is |
| 180 | valid anywhere (e.g. consists just of global symbols). */ |
| 181 | struct block *exp_valid_block; |
| 182 | /* Value of the watchpoint the last time we checked it. */ |
| 183 | value_ptr val; |
| 184 | |
| 185 | /* Holds the value chain for a hardware watchpoint expression. */ |
| 186 | value_ptr val_chain; |
| 187 | |
| 188 | /* Holds the address of the related watchpoint_scope breakpoint |
| 189 | when using watchpoints on local variables (might the concept |
| 190 | of a related breakpoint be useful elsewhere, if not just call |
| 191 | it the watchpoint_scope breakpoint or something like that. FIXME). */ |
| 192 | struct breakpoint *related_breakpoint; |
| 193 | |
| 194 | /* Holds the frame address which identifies the frame this watchpoint |
| 195 | should be evaluated in, or NULL if the watchpoint should be evaluated |
| 196 | on the outermost frame. */ |
| 197 | CORE_ADDR watchpoint_frame; |
| 198 | |
| 199 | /* Thread number for thread-specific breakpoint, or -1 if don't care */ |
| 200 | int thread; |
| 201 | |
| 202 | /* Count of the number of times this breakpoint was taken, dumped |
| 203 | with the info, but not used for anything else. Useful for |
| 204 | seeing how many times you hit a break prior to the program |
| 205 | aborting, so you can back up to just before the abort. */ |
| 206 | int hit_count; |
| 207 | |
| 208 | }; |
| 209 | \f |
| 210 | /* The following stuff is an abstract data type "bpstat" ("breakpoint status"). |
| 211 | This provides the ability to determine whether we have stopped at a |
| 212 | breakpoint, and what we should do about it. */ |
| 213 | |
| 214 | typedef struct bpstats *bpstat; |
| 215 | |
| 216 | /* Interface: */ |
| 217 | /* Clear a bpstat so that it says we are not at any breakpoint. |
| 218 | Also free any storage that is part of a bpstat. */ |
| 219 | extern void bpstat_clear PARAMS ((bpstat *)); |
| 220 | |
| 221 | /* Return a copy of a bpstat. Like "bs1 = bs2" but all storage that |
| 222 | is part of the bpstat is copied as well. */ |
| 223 | extern bpstat bpstat_copy PARAMS ((bpstat)); |
| 224 | |
| 225 | extern bpstat bpstat_stop_status PARAMS ((CORE_ADDR *, int)); |
| 226 | \f |
| 227 | /* This bpstat_what stuff tells wait_for_inferior what to do with a |
| 228 | breakpoint (a challenging task). */ |
| 229 | |
| 230 | enum bpstat_what_main_action { |
| 231 | /* Perform various other tests; that is, this bpstat does not |
| 232 | say to perform any action (e.g. failed watchpoint and nothing |
| 233 | else). */ |
| 234 | BPSTAT_WHAT_KEEP_CHECKING, |
| 235 | |
| 236 | /* Rather than distinguish between noisy and silent stops here, it |
| 237 | might be cleaner to have bpstat_print make that decision (also |
| 238 | taking into account stop_print_frame and source_only). But the |
| 239 | implications are a bit scary (interaction with auto-displays, etc.), |
| 240 | so I won't try it. */ |
| 241 | |
| 242 | /* Stop silently. */ |
| 243 | BPSTAT_WHAT_STOP_SILENT, |
| 244 | |
| 245 | /* Stop and print. */ |
| 246 | BPSTAT_WHAT_STOP_NOISY, |
| 247 | |
| 248 | /* Remove breakpoints, single step once, then put them back in and |
| 249 | go back to what we were doing. It's possible that this should be |
| 250 | removed from the main_action and put into a separate field, to more |
| 251 | cleanly handle BPSTAT_WHAT_CLEAR_LONGJMP_RESUME_SINGLE. */ |
| 252 | BPSTAT_WHAT_SINGLE, |
| 253 | |
| 254 | /* Set longjmp_resume breakpoint, remove all other breakpoints, |
| 255 | and continue. The "remove all other breakpoints" part is required |
| 256 | if we are also stepping over another breakpoint as well as doing |
| 257 | the longjmp handling. */ |
| 258 | BPSTAT_WHAT_SET_LONGJMP_RESUME, |
| 259 | |
| 260 | /* Clear longjmp_resume breakpoint, then handle as |
| 261 | BPSTAT_WHAT_KEEP_CHECKING. */ |
| 262 | BPSTAT_WHAT_CLEAR_LONGJMP_RESUME, |
| 263 | |
| 264 | /* Clear longjmp_resume breakpoint, then handle as BPSTAT_WHAT_SINGLE. */ |
| 265 | BPSTAT_WHAT_CLEAR_LONGJMP_RESUME_SINGLE, |
| 266 | |
| 267 | /* Clear step resume breakpoint, and keep checking. */ |
| 268 | BPSTAT_WHAT_STEP_RESUME, |
| 269 | |
| 270 | /* Clear through_sigtramp breakpoint, muck with trap_expected, and keep |
| 271 | checking. */ |
| 272 | BPSTAT_WHAT_THROUGH_SIGTRAMP, |
| 273 | |
| 274 | /* Check the dynamic linker's data structures for new libraries, then |
| 275 | keep checking. */ |
| 276 | BPSTAT_WHAT_CHECK_SHLIBS, |
| 277 | |
| 278 | /* This is just used to keep track of how many enums there are. */ |
| 279 | BPSTAT_WHAT_LAST |
| 280 | }; |
| 281 | |
| 282 | struct bpstat_what { |
| 283 | enum bpstat_what_main_action main_action; |
| 284 | |
| 285 | /* Did we hit a call dummy breakpoint? This only goes with a main_action |
| 286 | of BPSTAT_WHAT_STOP_SILENT or BPSTAT_WHAT_STOP_NOISY (the concept of |
| 287 | continuing from a call dummy without popping the frame is not a |
| 288 | useful one). */ |
| 289 | int call_dummy; |
| 290 | }; |
| 291 | |
| 292 | /* Tell what to do about this bpstat. */ |
| 293 | struct bpstat_what bpstat_what PARAMS ((bpstat)); |
| 294 | \f |
| 295 | /* Find the bpstat associated with a breakpoint. NULL otherwise. */ |
| 296 | bpstat bpstat_find_breakpoint PARAMS ((bpstat, struct breakpoint *)); |
| 297 | |
| 298 | /* Nonzero if a signal that we got in wait() was due to circumstances |
| 299 | explained by the BS. */ |
| 300 | /* Currently that is true if we have hit a breakpoint, or if there is |
| 301 | a watchpoint enabled. */ |
| 302 | #define bpstat_explains_signal(bs) ((bs) != NULL) |
| 303 | |
| 304 | /* Nonzero if we should step constantly (e.g. watchpoints on machines |
| 305 | without hardware support). This isn't related to a specific bpstat, |
| 306 | just to things like whether watchpoints are set. */ |
| 307 | extern int bpstat_should_step PARAMS ((void)); |
| 308 | |
| 309 | /* Print a message indicating what happened. Returns nonzero to |
| 310 | say that only the source line should be printed after this (zero |
| 311 | return means print the frame as well as the source line). */ |
| 312 | extern int bpstat_print PARAMS ((bpstat)); |
| 313 | |
| 314 | /* Return the breakpoint number of the first breakpoint we are stopped |
| 315 | at. *BSP upon return is a bpstat which points to the remaining |
| 316 | breakpoints stopped at (but which is not guaranteed to be good for |
| 317 | anything but further calls to bpstat_num). |
| 318 | Return 0 if passed a bpstat which does not indicate any breakpoints. */ |
| 319 | extern int bpstat_num PARAMS ((bpstat *)); |
| 320 | |
| 321 | /* Perform actions associated with having stopped at *BSP. Actually, we just |
| 322 | use this for breakpoint commands. Perhaps other actions will go here |
| 323 | later, but this is executed at a late time (from the command loop). */ |
| 324 | extern void bpstat_do_actions PARAMS ((bpstat *)); |
| 325 | |
| 326 | /* Modify BS so that the actions will not be performed. */ |
| 327 | extern void bpstat_clear_actions PARAMS ((bpstat)); |
| 328 | |
| 329 | /* Implementation: */ |
| 330 | struct bpstats |
| 331 | { |
| 332 | /* Linked list because there can be two breakpoints at the |
| 333 | same place, and a bpstat reflects the fact that both have been hit. */ |
| 334 | bpstat next; |
| 335 | /* Breakpoint that we are at. */ |
| 336 | struct breakpoint *breakpoint_at; |
| 337 | /* Commands left to be done. */ |
| 338 | struct command_line *commands; |
| 339 | /* Old value associated with a watchpoint. */ |
| 340 | value_ptr old_val; |
| 341 | |
| 342 | /* Nonzero if this breakpoint tells us to print the frame. */ |
| 343 | char print; |
| 344 | |
| 345 | /* Nonzero if this breakpoint tells us to stop. */ |
| 346 | char stop; |
| 347 | |
| 348 | /* Function called by bpstat_print to print stuff associated with |
| 349 | this element of the bpstat chain. Returns 0 or 1 just like |
| 350 | bpstat_print, or -1 if it can't deal with it. */ |
| 351 | int (*print_it) PARAMS((bpstat bs)); |
| 352 | }; |
| 353 | \f |
| 354 | /* Prototypes for breakpoint-related functions. */ |
| 355 | |
| 356 | #ifdef __STDC__ /* Forward declarations for prototypes */ |
| 357 | struct frame_info; |
| 358 | #endif |
| 359 | |
| 360 | extern int breakpoint_here_p PARAMS ((CORE_ADDR)); |
| 361 | |
| 362 | extern int frame_in_dummy PARAMS ((struct frame_info *)); |
| 363 | |
| 364 | extern int breakpoint_thread_match PARAMS ((CORE_ADDR, int)); |
| 365 | |
| 366 | extern void until_break_command PARAMS ((char *, int)); |
| 367 | |
| 368 | extern void breakpoint_re_set PARAMS ((void)); |
| 369 | |
| 370 | extern void clear_momentary_breakpoints PARAMS ((void)); |
| 371 | |
| 372 | extern struct breakpoint *set_momentary_breakpoint |
| 373 | PARAMS ((struct symtab_and_line, struct frame_info *, enum bptype)); |
| 374 | |
| 375 | extern void set_ignore_count PARAMS ((int, int, int)); |
| 376 | |
| 377 | extern void set_default_breakpoint PARAMS ((int, CORE_ADDR, struct symtab *, int)); |
| 378 | |
| 379 | extern void mark_breakpoints_out PARAMS ((void)); |
| 380 | |
| 381 | extern void breakpoint_init_inferior PARAMS ((void)); |
| 382 | |
| 383 | extern void delete_breakpoint PARAMS ((struct breakpoint *)); |
| 384 | |
| 385 | extern void breakpoint_auto_delete PARAMS ((bpstat)); |
| 386 | |
| 387 | extern void breakpoint_clear_ignore_counts PARAMS ((void)); |
| 388 | |
| 389 | extern void break_command PARAMS ((char *, int)); |
| 390 | |
| 391 | extern int insert_breakpoints PARAMS ((void)); |
| 392 | |
| 393 | extern int remove_breakpoints PARAMS ((void)); |
| 394 | |
| 395 | extern void enable_longjmp_breakpoint PARAMS ((void)); |
| 396 | |
| 397 | extern void disable_longjmp_breakpoint PARAMS ((void)); |
| 398 | |
| 399 | extern void set_longjmp_resume_breakpoint PARAMS ((CORE_ADDR, |
| 400 | struct frame_info *)); |
| 401 | |
| 402 | extern void clear_breakpoint_hit_counts PARAMS ((void)); |
| 403 | |
| 404 | /* The following are for displays, which aren't really breakpoints, but |
| 405 | here is as good a place as any for them. */ |
| 406 | |
| 407 | extern void disable_current_display PARAMS ((void)); |
| 408 | |
| 409 | extern void do_displays PARAMS ((void)); |
| 410 | |
| 411 | extern void disable_display PARAMS ((int)); |
| 412 | |
| 413 | extern void clear_displays PARAMS ((void)); |
| 414 | |
| 415 | extern void disable_breakpoint PARAMS ((struct breakpoint *)); |
| 416 | |
| 417 | extern void enable_breakpoint PARAMS ((struct breakpoint *)); |
| 418 | |
| 419 | extern void create_solib_event_breakpoint PARAMS ((CORE_ADDR)); |
| 420 | |
| 421 | extern void remove_solib_event_breakpoints PARAMS ((void)); |
| 422 | |
| 423 | extern void re_enable_breakpoints_in_shlibs PARAMS ((void)); |
| 424 | |
| 425 | #endif /* !defined (BREAKPOINT_H) */ |