| 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 | /* 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_until, /* used by until command */ |
| 43 | bp_finish, /* used by finish command */ |
| 44 | bp_watchpoint, /* Watchpoint */ |
| 45 | bp_longjmp, /* secret breakpoint to find longjmp() */ |
| 46 | bp_longjmp_resume, /* secret breakpoint to escape longjmp() */ |
| 47 | |
| 48 | /* Used by wait_for_inferior for stepping over subroutine calls, for |
| 49 | stepping over signal handlers, and for skipping prologues. */ |
| 50 | bp_step_resume, |
| 51 | |
| 52 | /* The breakpoint at the end of a call dummy. */ |
| 53 | /* FIXME: What if the function we are calling longjmp()s out of the |
| 54 | call, or the user gets out with the "return" command? We currently |
| 55 | have no way of cleaning up the breakpoint in these (obscure) situations. |
| 56 | (Probably can solve this by noticing longjmp, "return", etc., it's |
| 57 | similar to noticing when a watchpoint on a local variable goes out |
| 58 | of scope (with hardware support for watchpoints)). */ |
| 59 | bp_call_dummy |
| 60 | }; |
| 61 | |
| 62 | /* States of enablement of breakpoint. */ |
| 63 | |
| 64 | enum enable { disabled, enabled}; |
| 65 | |
| 66 | /* Disposition of breakpoint. Ie: what to do after hitting it. */ |
| 67 | |
| 68 | enum bpdisp { |
| 69 | delete, /* Delete it */ |
| 70 | disable, /* Disable it */ |
| 71 | donttouch /* Leave it alone */ |
| 72 | }; |
| 73 | |
| 74 | /* Note that the ->silent field is not currently used by any commands |
| 75 | (though the code is in there if it was to be, and set_raw_breakpoint |
| 76 | does set it to 0). I implemented it because I thought it would be |
| 77 | useful for a hack I had to put in; I'm going to leave it in because |
| 78 | I can see how there might be times when it would indeed be useful */ |
| 79 | |
| 80 | /* This is for a breakpoint or a watchpoint. */ |
| 81 | |
| 82 | struct breakpoint |
| 83 | { |
| 84 | struct breakpoint *next; |
| 85 | /* Type of breakpoint. */ |
| 86 | enum bptype type; |
| 87 | /* Zero means disabled; remember the info but don't break here. */ |
| 88 | enum enable enable; |
| 89 | /* What to do with this breakpoint after we hit it. */ |
| 90 | enum bpdisp disposition; |
| 91 | /* Number assigned to distinguish breakpoints. */ |
| 92 | int number; |
| 93 | |
| 94 | /* Address to break at, or NULL if not a breakpoint. */ |
| 95 | CORE_ADDR address; |
| 96 | |
| 97 | /* Line number of this address. Only matters if address is |
| 98 | non-NULL. */ |
| 99 | |
| 100 | int line_number; |
| 101 | |
| 102 | /* Source file name of this address. Only matters if address is |
| 103 | non-NULL. */ |
| 104 | |
| 105 | char *source_file; |
| 106 | |
| 107 | /* Non-zero means a silent breakpoint (don't print frame info |
| 108 | if we stop here). */ |
| 109 | unsigned char silent; |
| 110 | /* Number of stops at this breakpoint that should |
| 111 | be continued automatically before really stopping. */ |
| 112 | int ignore_count; |
| 113 | /* "Real" contents of byte where breakpoint has been inserted. |
| 114 | Valid only when breakpoints are in the program. Under the complete |
| 115 | control of the target insert_breakpoint and remove_breakpoint routines. |
| 116 | No other code should assume anything about the value(s) here. */ |
| 117 | char shadow_contents[BREAKPOINT_MAX]; |
| 118 | /* Nonzero if this breakpoint is now inserted. Only matters if address |
| 119 | is non-NULL. */ |
| 120 | char inserted; |
| 121 | /* Nonzero if this is not the first breakpoint in the list |
| 122 | for the given address. Only matters if address is non-NULL. */ |
| 123 | char duplicate; |
| 124 | /* Chain of command lines to execute when this breakpoint is hit. */ |
| 125 | struct command_line *commands; |
| 126 | /* Stack depth (address of frame). If nonzero, break only if fp |
| 127 | equals this. */ |
| 128 | FRAME_ADDR frame; |
| 129 | /* Conditional. Break only if this expression's value is nonzero. */ |
| 130 | struct expression *cond; |
| 131 | |
| 132 | /* String we used to set the breakpoint (malloc'd). Only matters if |
| 133 | address is non-NULL. */ |
| 134 | char *addr_string; |
| 135 | /* String form of the breakpoint condition (malloc'd), or NULL if there |
| 136 | is no condition. */ |
| 137 | char *cond_string; |
| 138 | /* String form of exp (malloc'd), or NULL if none. */ |
| 139 | char *exp_string; |
| 140 | |
| 141 | /* The expression we are watching, or NULL if not a watchpoint. */ |
| 142 | struct expression *exp; |
| 143 | /* The largest block within which it is valid, or NULL if it is |
| 144 | valid anywhere (e.g. consists just of global symbols). */ |
| 145 | struct block *exp_valid_block; |
| 146 | /* Value of the watchpoint the last time we checked it. */ |
| 147 | value val; |
| 148 | }; |
| 149 | \f |
| 150 | /* The following stuff is an abstract data type "bpstat" ("breakpoint status"). |
| 151 | This provides the ability to determine whether we have stopped at a |
| 152 | breakpoint, and what we should do about it. */ |
| 153 | |
| 154 | typedef struct bpstat *bpstat; |
| 155 | |
| 156 | /* Interface: */ |
| 157 | /* Clear a bpstat so that it says we are not at any breakpoint. |
| 158 | Also free any storage that is part of a bpstat. */ |
| 159 | extern void bpstat_clear PARAMS ((bpstat *)); |
| 160 | |
| 161 | /* Return a copy of a bpstat. Like "bs1 = bs2" but all storage that |
| 162 | is part of the bpstat is copied as well. */ |
| 163 | extern bpstat bpstat_copy PARAMS ((bpstat)); |
| 164 | |
| 165 | /* FIXME: prototypes uses equivalence between FRAME_ADDR and CORE_ADDR */ |
| 166 | extern bpstat bpstat_stop_status PARAMS ((CORE_ADDR *, CORE_ADDR, int)); |
| 167 | \f |
| 168 | /* This bpstat_what stuff tells wait_for_inferior what to do with a |
| 169 | breakpoint (a challenging task). */ |
| 170 | |
| 171 | enum bpstat_what_main_action { |
| 172 | /* Perform various other tests; that is, this bpstat does not |
| 173 | say to perform any action (e.g. failed watchpoint and nothing |
| 174 | else). */ |
| 175 | BPSTAT_WHAT_KEEP_CHECKING, |
| 176 | |
| 177 | /* Rather than distinguish between noisy and silent stops here, it |
| 178 | might be cleaner to have bpstat_print make that decision (also |
| 179 | taking into account stop_print_frame and source_only). But the |
| 180 | implications are a bit scary (interaction with auto-displays, etc.), |
| 181 | so I won't try it. */ |
| 182 | |
| 183 | /* Stop silently. */ |
| 184 | BPSTAT_WHAT_STOP_SILENT, |
| 185 | |
| 186 | /* Stop and print. */ |
| 187 | BPSTAT_WHAT_STOP_NOISY, |
| 188 | |
| 189 | /* Remove breakpoints, single step once, then put them back in and |
| 190 | go back to what we were doing. It's possible that this should be |
| 191 | removed from the main_action and put into a separate field, to more |
| 192 | cleanly handle BPSTAT_WHAT_CLEAR_LONGJMP_RESUME_SINGLE. */ |
| 193 | BPSTAT_WHAT_SINGLE, |
| 194 | |
| 195 | /* Set longjmp_resume breakpoint, remove all other breakpoints, |
| 196 | and continue. The "remove all other breakpoints" part is required |
| 197 | if we are also stepping over another breakpoint as well as doing |
| 198 | the longjmp handling. */ |
| 199 | BPSTAT_WHAT_SET_LONGJMP_RESUME, |
| 200 | |
| 201 | /* Clear longjmp_resume breakpoint, then handle as |
| 202 | BPSTAT_WHAT_KEEP_CHECKING. */ |
| 203 | BPSTAT_WHAT_CLEAR_LONGJMP_RESUME, |
| 204 | |
| 205 | /* Clear longjmp_resume breakpoint, then handle as BPSTAT_WHAT_SINGLE. */ |
| 206 | BPSTAT_WHAT_CLEAR_LONGJMP_RESUME_SINGLE, |
| 207 | |
| 208 | /* This is just used to keep track of how many enums there are. */ |
| 209 | BPSTAT_WHAT_LAST |
| 210 | }; |
| 211 | |
| 212 | struct bpstat_what { |
| 213 | enum bpstat_what_main_action main_action : 4; |
| 214 | |
| 215 | /* Did we hit the step resume breakpoint? This is separate from the |
| 216 | main_action to allow for it to be combined with any of the main |
| 217 | actions. */ |
| 218 | unsigned int step_resume : 1; |
| 219 | |
| 220 | /* Did we hit a call dummy breakpoint? This only goes with a main_action |
| 221 | of BPSTAT_WHAT_STOP_SILENT or BPSTAT_WHAT_STOP_NOISY (the concept of |
| 222 | continuing from a call dummy without popping the frame is not a |
| 223 | useful one). */ |
| 224 | unsigned int call_dummy : 1; |
| 225 | }; |
| 226 | |
| 227 | /* Tell what to do about this bpstat. */ |
| 228 | struct bpstat_what bpstat_what PARAMS ((bpstat)); |
| 229 | \f |
| 230 | /* Find the bpstat associated with a breakpoint. NULL otherwise. */ |
| 231 | bpstat bpstat_find_breakpoint PARAMS ((bpstat, struct breakpoint *)); |
| 232 | |
| 233 | /* Nonzero if a signal that we got in wait() was due to circumstances |
| 234 | explained by the BS. */ |
| 235 | /* Currently that is true if we have hit a breakpoint, or if there is |
| 236 | a watchpoint enabled. */ |
| 237 | #define bpstat_explains_signal(bs) ((bs) != NULL) |
| 238 | |
| 239 | /* Nonzero if we should step constantly (e.g. watchpoints on machines |
| 240 | without hardware support). This isn't related to a specific bpstat, |
| 241 | just to things like whether watchpoints are set. */ |
| 242 | extern int bpstat_should_step PARAMS ((void)); |
| 243 | |
| 244 | /* Print a message indicating what happened. Returns nonzero to |
| 245 | say that only the source line should be printed after this (zero |
| 246 | return means print the frame as well as the source line). */ |
| 247 | extern int bpstat_print PARAMS ((bpstat)); |
| 248 | |
| 249 | /* Return the breakpoint number of the first breakpoint we are stopped |
| 250 | at. *BSP upon return is a bpstat which points to the remaining |
| 251 | breakpoints stopped at (but which is not guaranteed to be good for |
| 252 | anything but further calls to bpstat_num). |
| 253 | Return 0 if passed a bpstat which does not indicate any breakpoints. */ |
| 254 | extern int bpstat_num PARAMS ((bpstat *)); |
| 255 | |
| 256 | /* Perform actions associated with having stopped at *BSP. Actually, we just |
| 257 | use this for breakpoint commands. Perhaps other actions will go here |
| 258 | later, but this is executed at a late time (from the command loop). */ |
| 259 | extern void bpstat_do_actions PARAMS ((bpstat *)); |
| 260 | |
| 261 | /* Modify BS so that the actions will not be performed. */ |
| 262 | extern void bpstat_clear_actions PARAMS ((bpstat)); |
| 263 | |
| 264 | /* Implementation: */ |
| 265 | struct bpstat |
| 266 | { |
| 267 | /* Linked list because there can be two breakpoints at the |
| 268 | same place, and a bpstat reflects the fact that both have been hit. */ |
| 269 | bpstat next; |
| 270 | /* Breakpoint that we are at. */ |
| 271 | struct breakpoint *breakpoint_at; |
| 272 | /* Commands left to be done. */ |
| 273 | struct command_line *commands; |
| 274 | /* Old value associated with a watchpoint. */ |
| 275 | value old_val; |
| 276 | |
| 277 | /* Nonzero if this breakpoint tells us to print the frame. */ |
| 278 | char print; |
| 279 | |
| 280 | /* Nonzero if this breakpoint tells us to stop. */ |
| 281 | char stop; |
| 282 | |
| 283 | /* Function called by bpstat_print to print stuff associated with |
| 284 | this element of the bpstat chain. Returns 0 or 1 just like |
| 285 | bpstat_print, or -1 if it can't deal with it. */ |
| 286 | int (*print_it) PARAMS((bpstat bs)); |
| 287 | }; |
| 288 | \f |
| 289 | /* Prototypes for breakpoint-related functions. */ |
| 290 | |
| 291 | #ifdef __STDC__ /* Forward declarations for prototypes */ |
| 292 | struct frame_info; |
| 293 | #endif |
| 294 | |
| 295 | extern int |
| 296 | breakpoint_here_p PARAMS ((CORE_ADDR)); |
| 297 | |
| 298 | extern void |
| 299 | until_break_command PARAMS ((char *, int)); |
| 300 | |
| 301 | extern void |
| 302 | breakpoint_re_set PARAMS ((void)); |
| 303 | |
| 304 | extern void |
| 305 | clear_momentary_breakpoints PARAMS ((void)); |
| 306 | |
| 307 | /* FIXME: Prototype uses equivalence of "struct frame_info *" and FRAME */ |
| 308 | extern struct breakpoint * |
| 309 | set_momentary_breakpoint PARAMS ((struct symtab_and_line, |
| 310 | struct frame_info *, |
| 311 | enum bptype)); |
| 312 | |
| 313 | extern void |
| 314 | set_ignore_count PARAMS ((int, int, int)); |
| 315 | |
| 316 | extern void |
| 317 | set_default_breakpoint PARAMS ((int, CORE_ADDR, struct symtab *, int)); |
| 318 | |
| 319 | extern void |
| 320 | mark_breakpoints_out PARAMS ((void)); |
| 321 | |
| 322 | extern void |
| 323 | breakpoint_init_inferior PARAMS ((void)); |
| 324 | |
| 325 | extern void |
| 326 | delete_breakpoint PARAMS ((struct breakpoint *)); |
| 327 | |
| 328 | extern void |
| 329 | breakpoint_auto_delete PARAMS ((bpstat)); |
| 330 | |
| 331 | extern void |
| 332 | breakpoint_clear_ignore_counts PARAMS ((void)); |
| 333 | |
| 334 | extern void |
| 335 | break_command PARAMS ((char *, int)); |
| 336 | |
| 337 | extern int |
| 338 | insert_breakpoints PARAMS ((void)); |
| 339 | |
| 340 | extern int |
| 341 | remove_breakpoints PARAMS ((void)); |
| 342 | |
| 343 | extern void |
| 344 | enable_longjmp_breakpoint PARAMS ((void)); |
| 345 | |
| 346 | extern void |
| 347 | disable_longjmp_breakpoint PARAMS ((void)); |
| 348 | |
| 349 | extern void |
| 350 | set_longjmp_resume_breakpoint PARAMS ((CORE_ADDR, FRAME)); |
| 351 | |
| 352 | /* The following are for displays, which aren't really breakpoints, but |
| 353 | here is as good a place as any for them. */ |
| 354 | |
| 355 | extern void |
| 356 | disable_current_display PARAMS ((void)); |
| 357 | |
| 358 | extern void |
| 359 | do_displays PARAMS ((void)); |
| 360 | |
| 361 | extern void |
| 362 | disable_display PARAMS ((int)); |
| 363 | |
| 364 | extern void |
| 365 | clear_displays PARAMS ((void)); |
| 366 | |
| 367 | #endif /* !defined (BREAKPOINT_H) */ |