| 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) */ |