Mercurial > hg > xemacs-beta
annotate src/backtrace.h @ 5857:6ec4964c1687
Be more careful about echo_buf arithmetic, event-stream.c.
src/ChangeLog addition:
2015-03-12 Aidan Kehoe <kehoea@parhasard.net>
* event-stream.c (lookup_command_event):
Check whether echo_buf_fill_pointer is negative before using it in
arithmetic, avoiding a crash in GC.
Oddly the old code didn't do this check and didn't crash, but its
echo_buf was from malloced memory, not from our string data, so
there may have been more room to manoeuvre.
| author | Aidan Kehoe <kehoea@parhasard.net> |
|---|---|
| date | Thu, 12 Mar 2015 23:31:42 +0000 |
| parents | 308d34e9f07d |
| children |
| rev | line source |
|---|---|
| 428 | 1 /* The lisp stack. |
| 2 Copyright (C) 1985, 1986, 1987, 1992, 1993 Free Software Foundation, Inc. | |
| 1292 | 3 Copyright (C) 2002, 2003 Ben Wing. |
| 428 | 4 |
| 5 This file is part of XEmacs. | |
| 6 | |
|
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7 XEmacs is free software: you can redistribute it and/or modify it |
| 428 | 8 under the terms of the GNU General Public License as published by the |
|
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9 Free Software Foundation, either version 3 of the License, or (at your |
|
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10 option) any later version. |
| 428 | 11 |
| 12 XEmacs is distributed in the hope that it will be useful, but WITHOUT | |
| 13 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
| 14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
| 15 for more details. | |
| 16 | |
| 17 You should have received a copy of the GNU General Public License | |
|
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18 along with XEmacs. If not, see <http://www.gnu.org/licenses/>. */ |
| 428 | 19 |
| 20 /* Synched up with: FSF 19.30. Contained redundantly in various C files | |
| 21 in FSFmacs. */ | |
| 22 | |
| 23 /* Authorship: | |
| 24 | |
| 25 FSF: Original version; a long time ago. | |
| 26 XEmacs: split out of some C files. (For some obscure reason, a header | |
| 27 file couldn't be used in FSF Emacs, but XEmacs doesn't have | |
| 28 that problem.) | |
| 29 Mly (probably) or JWZ: Some changes. | |
| 30 */ | |
| 31 | |
| 440 | 32 #ifndef INCLUDED_backtrace_h_ |
| 33 #define INCLUDED_backtrace_h_ | |
| 428 | 34 |
| 35 #include <setjmp.h> | |
| 36 | |
| 853 | 37 #ifdef ERROR_CHECK_CATCH |
| 38 /* you can use this if you are trying to debug corruption in the | |
| 39 catchlist */ | |
| 40 void check_catchlist_sanity (void); | |
| 41 | |
| 42 /* you can use this if you are trying to debug corruption in the specbind | |
| 43 stack */ | |
| 44 void check_specbind_stack_sanity (void); | |
| 45 #else | |
| 46 #define check_catchlist_sanity() | |
| 47 #define check_specbind_stack_sanity() | |
| 48 #endif | |
| 49 | |
| 428 | 50 /* These definitions are used in eval.c and alloc.c */ |
| 51 | |
| 52 struct backtrace | |
| 53 { | |
| 54 struct backtrace *next; | |
| 55 Lisp_Object *function; | |
| 56 Lisp_Object *args; /* Points to vector of args. */ | |
| 57 int nargs; /* Length of vector. | |
| 58 If nargs is UNEVALLED, args points to | |
| 59 slot holding list of unevalled args */ | |
| 60 int pdlcount; /* specpdl_depth () when invoked */ | |
| 61 char evalargs; | |
| 62 /* Nonzero means call value of debugger when done with this operation. */ | |
| 63 char debug_on_exit; | |
| 1292 | 64 |
| 65 /* All the rest is information for the use of the profiler. The only | |
| 66 thing that eval.c does is set the first value to 0 so that it can | |
| 67 be relied upon. */ | |
| 68 | |
| 69 /* ----------------------------------------------------------------- */ | |
| 70 | |
| 71 /* 0 = profiling not turned on when function called. | |
| 72 Since profiling can be turned on and off dynamically, we can't | |
| 73 always count on having info recorded when a function was called | |
| 74 and need to take evasive action if necessary. | |
| 75 1 = profiling turned on but function not yet actually called. Lots of | |
| 76 stuff can happen between when a function is pushed onto the | |
| 77 backtrace list and when it's actually called (e.g. evalling its | |
| 78 arguments, autoloading, etc.). For greater accuracy we don't | |
| 79 treat the preamble stuff as part of the function itself. | |
| 80 2 = profiling turned on, function called. | |
| 81 */ | |
| 82 char function_being_called; | |
| 83 /* The trick here is handling recursive functions and dealing with the | |
| 84 dynamicity of in-profile/not-in-profile. I used to just use a bunch | |
| 85 of hash tables for all info but that fails in the presence of | |
| 86 recursive functions because they can modify values out from under | |
| 87 you. The algorithm here is that we record the total_ticks and | |
| 88 total_consing, as well as the current values of `total-timing' and | |
| 89 `total-gc-usage' for the OBJ -- that's because recursive functions, | |
| 90 which get called later and exit early, will go ahead and modify the | |
| 91 `total-timing' and `total-gc-usage' for the fun, even though it's | |
| 92 not "correct" because the outer function is still running. However, | |
| 93 if we ask for profiling info at this point, at least we're getting | |
| 94 SOME info. | |
| 95 | |
| 96 So ... On entry, we record these four values. On exit, we compute | |
| 97 an offset from the recorded value to the current value and then | |
| 98 store it into the appropriate hash table entry, using the recorded | |
| 99 value in the entry rather than the actual one. (Inner recursive | |
| 100 functions may have added their own values to the total-counts, and | |
| 101 we want to subsume them, not add to them.) | |
| 102 | |
| 103 #### Also we need to go through the backtrace list during | |
| 104 stop-profiling and record values, just like for unwind_to. */ | |
| 105 EMACS_INT current_total_timing_val; | |
| 106 EMACS_INT current_total_gc_usage_val; | |
| 107 EMACS_UINT total_ticks_at_start; | |
| 108 EMACS_UINT total_consing_at_start; | |
| 428 | 109 }; |
| 110 | |
| 111 /* This structure helps implement the `catch' and `throw' control | |
| 112 structure. A struct catchtag contains all the information needed | |
| 113 to restore the state of the interpreter after a non-local jump. | |
| 853 | 114 (No information is stored concerning how to restore the state of |
| 115 the condition-handler list; this is handled implicitly through | |
| 116 an unwind-protect. unwind-protects are on the specbind stack, | |
| 117 which is reset to its proper value by `throw'. In the process of | |
| 118 that, any intervening bindings are reset and unwind-protects called, | |
| 119 which fixes up the condition-handler list. | |
| 428 | 120 |
| 121 catchtag structures are chained together in the C calling stack; | |
| 122 the `next' member points to the next outer catchtag. | |
| 123 | |
| 124 A call like (throw TAG VAL) searches for a catchtag whose `tag' | |
| 853 | 125 member is TAG, and then unbinds to it. A value of Vcatch_everything_tag |
| 126 for the `tag' member of a catchtag is special and means "catch all throws, | |
| 127 regardless of the tag". This is used internally by the C code. The `val' | |
| 128 member is used to hold VAL while the stack is unwound; `val' is returned | |
| 129 as the value of the catch form. The `actual_tag' member holds the value | |
| 130 of TAG as passed to throw, so that it can be retrieved when catches with | |
| 131 Vcatch_everything_tag are set up. | |
| 428 | 132 |
| 133 All the other members are concerned with restoring the interpreter | |
| 134 state. */ | |
| 135 | |
| 136 struct catchtag | |
| 137 { | |
| 138 Lisp_Object tag; | |
| 853 | 139 /* Stores the actual tag used in `throw'; the same as TAG, unless |
| 140 TAG is Vcatch_everything_tag. */ | |
| 141 Lisp_Object actual_tag; | |
| 2532 | 142 /* A backtrace prior to the throw, used with Vcatch_everything_tag. */ |
| 143 Lisp_Object backtrace; | |
| 428 | 144 Lisp_Object val; |
| 145 struct catchtag *next; | |
| 146 struct gcpro *gcpro; | |
| 147 JMP_BUF jmp; | |
| 148 struct backtrace *backlist; | |
| 149 #if 0 /* FSFmacs */ | |
| 617 | 150 /* FSF uses a separate handler stack to hold condition-cases, |
| 151 where we use Vcondition_handlers. We should switch to their | |
| 152 system becaue it avoids the need to mess around with consing | |
| 153 up stuff and then dangerously freeing it. See comment in | |
| 154 condition_case_unwind(). */ | |
| 428 | 155 struct handler *handlerlist; |
| 156 #endif | |
| 157 int lisp_eval_depth; | |
| 158 int pdlcount; | |
| 159 #if 0 /* FSFmacs */ | |
| 160 /* This is the equivalent of async_timer_suppress_count. | |
| 161 We probably don't have to bother with this. */ | |
| 162 int poll_suppress_count; | |
| 163 #endif | |
| 164 }; | |
| 165 | |
| 166 /* Dynamic-binding-o-rama */ | |
| 167 | |
| 168 /* Structure for recording Lisp call stack for backtrace purposes. */ | |
| 169 | |
| 170 /* The special binding stack holds the outer values of variables while | |
| 171 they are bound by a function application or a let form, stores the | |
| 172 code to be executed for Lisp unwind-protect forms, and stores the C | |
| 173 functions to be called for record_unwind_protect. | |
| 174 | |
| 175 If func is non-zero, undoing this binding applies func to old_value; | |
| 176 This implements record_unwind_protect. | |
| 177 If func is zero and symbol is nil, undoing this binding evaluates | |
| 178 the list of forms in old_value; this implements Lisp's unwind-protect | |
| 179 form. | |
| 180 Otherwise, undoing this binding stores old_value as symbol's value; this | |
| 181 undoes the bindings made by a let form or function call. */ | |
| 182 | |
| 183 struct specbinding | |
| 184 { | |
| 185 Lisp_Object symbol; | |
| 186 Lisp_Object old_value; | |
| 187 Lisp_Object (*func) (Lisp_Object); /* for unwind-protect */ | |
| 188 }; | |
| 189 | |
| 190 #if 0 /* FSFmacs */ | |
| 191 /* #### */ | |
| 192 /* Everything needed to describe an active condition case. */ | |
| 193 struct handler | |
| 194 { | |
| 195 /* The handler clauses and variable from the condition-case form. */ | |
| 196 Lisp_Object handler; | |
| 197 Lisp_Object var; | |
| 198 /* Fsignal stores here the condition-case clause that applies, | |
| 199 and Fcondition_case thus knows which clause to run. */ | |
| 200 Lisp_Object chosen_clause; | |
| 201 | |
| 202 /* Used to effect the longjmp() out to the handler. */ | |
| 203 struct catchtag *tag; | |
| 204 | |
| 205 /* The next enclosing handler. */ | |
| 206 struct handler *next; | |
| 207 }; | |
| 208 | |
| 209 extern struct handler *handlerlist; | |
| 210 | |
| 211 #endif | |
| 212 | |
| 213 /* These are extern because GC needs to mark them */ | |
| 214 extern struct specbinding *specpdl; | |
| 215 extern struct specbinding *specpdl_ptr; | |
| 216 extern struct catchtag *catchlist; | |
| 217 extern struct backtrace *backtrace_list; | |
| 218 | |
| 771 | 219 /* Most callers should simply use specbind() and unbind_to_1(), but if |
| 428 | 220 speed is REALLY IMPORTANT, you can use the faster macros below */ |
| 221 void specbind_magic (Lisp_Object, Lisp_Object); | |
| 647 | 222 void grow_specpdl (EMACS_INT reserved); |
| 428 | 223 void unbind_to_hairy (int); |
| 224 extern int specpdl_size; | |
| 225 | |
| 226 /* Inline version of specbind(). | |
| 227 Use this instead of specbind() if speed is sufficiently important | |
| 228 to save the overhead of even a single function call. */ | |
| 229 #define SPECBIND(symbol_object, value_object) do { \ | |
| 230 Lisp_Object SB_symbol = (symbol_object); \ | |
| 231 Lisp_Object SB_newval = (value_object); \ | |
| 232 Lisp_Object SB_oldval; \ | |
| 440 | 233 Lisp_Symbol *SB_sym; \ |
| 428 | 234 \ |
| 235 SPECPDL_RESERVE (1); \ | |
| 236 \ | |
| 237 CHECK_SYMBOL (SB_symbol); \ | |
| 238 SB_sym = XSYMBOL (SB_symbol); \ | |
| 239 SB_oldval = SB_sym->value; \ | |
| 240 \ | |
| 241 if (!SYMBOL_VALUE_MAGIC_P (SB_oldval) || UNBOUNDP (SB_oldval)) \ | |
| 242 { \ | |
| 440 | 243 /* #### the following test will go away when we have a constant \ |
| 428 | 244 symbol magic object */ \ |
| 245 if (EQ (SB_symbol, Qnil) || \ | |
| 246 EQ (SB_symbol, Qt) || \ | |
| 247 SYMBOL_IS_KEYWORD (SB_symbol)) \ | |
| 248 reject_constant_symbols (SB_symbol, SB_newval, 0, \ | |
| 249 UNBOUNDP (SB_newval) ? \ | |
| 250 Qmakunbound : Qset); \ | |
| 251 \ | |
| 252 specpdl_ptr->symbol = SB_symbol; \ | |
| 253 specpdl_ptr->old_value = SB_oldval; \ | |
| 254 specpdl_ptr->func = 0; \ | |
| 255 specpdl_ptr++; \ | |
| 256 specpdl_depth_counter++; \ | |
| 257 \ | |
| 258 SB_sym->value = (SB_newval); \ | |
| 259 } \ | |
| 260 else \ | |
| 261 specbind_magic (SB_symbol, SB_newval); \ | |
| 853 | 262 check_specbind_stack_sanity (); \ |
| 428 | 263 } while (0) |
| 264 | |
| 265 /* An even faster, but less safe inline version of specbind(). | |
| 266 Caller guarantees that: | |
| 267 - SYMBOL is a non-constant symbol (i.e. not Qnil, Qt, or keyword). | |
| 268 - specpdl_depth_counter >= specpdl_size. | |
| 269 Else we crash. */ | |
| 270 #define SPECBIND_FAST_UNSAFE(symbol_object, value_object) do { \ | |
| 271 Lisp_Object SFU_symbol = (symbol_object); \ | |
| 272 Lisp_Object SFU_newval = (value_object); \ | |
| 440 | 273 Lisp_Symbol *SFU_sym = XSYMBOL (SFU_symbol); \ |
| 428 | 274 Lisp_Object SFU_oldval = SFU_sym->value; \ |
| 814 | 275 /* Most of the time, will be previously unbound. #### With a bit of \ |
| 276 rearranging, this could be reduced to only one check. */ \ | |
| 277 if (UNBOUNDP (SFU_oldval) || !SYMBOL_VALUE_MAGIC_P (SFU_oldval)) \ | |
| 428 | 278 { \ |
| 279 specpdl_ptr->symbol = SFU_symbol; \ | |
| 280 specpdl_ptr->old_value = SFU_oldval; \ | |
| 281 specpdl_ptr->func = 0; \ | |
| 282 specpdl_ptr++; \ | |
| 283 specpdl_depth_counter++; \ | |
| 284 \ | |
| 285 SFU_sym->value = (SFU_newval); \ | |
| 286 } \ | |
| 287 else \ | |
| 288 specbind_magic (SFU_symbol, SFU_newval); \ | |
| 853 | 289 check_specbind_stack_sanity (); \ |
| 428 | 290 } while (0) |
| 291 /* Request enough room for SIZE future entries on special binding stack */ | |
| 292 #define SPECPDL_RESERVE(size) do { \ | |
| 647 | 293 EMACS_INT SR_size = (size); \ |
| 428 | 294 if (specpdl_depth() + SR_size >= specpdl_size) \ |
| 295 grow_specpdl (SR_size); \ | |
| 296 } while (0) | |
| 297 | |
| 771 | 298 /* Inline version of unbind_to_1(). |
| 299 [[Use this instead of unbind_to_1() if speed is sufficiently important | |
| 300 to save the overhead of even a single function call.]] | |
| 301 This is bogus pseudo-optimization. --ben | |
| 428 | 302 |
| 771 | 303 Most of the time, unbind_to_1() is called only on ordinary |
| 428 | 304 variables, so optimize for that. */ |
| 305 #define UNBIND_TO_GCPRO(count, value) do { \ | |
| 306 int UNBIND_TO_count = (count); \ | |
| 307 while (specpdl_depth_counter != UNBIND_TO_count) \ | |
| 308 { \ | |
| 440 | 309 Lisp_Symbol *sym; \ |
| 428 | 310 --specpdl_ptr; \ |
| 311 --specpdl_depth_counter; \ | |
| 312 \ | |
| 313 if (specpdl_ptr->func != 0 || \ | |
| 314 ((sym = XSYMBOL (specpdl_ptr->symbol)), \ | |
| 315 SYMBOL_VALUE_MAGIC_P (sym->value))) \ | |
| 316 { \ | |
| 317 struct gcpro gcpro1; \ | |
| 318 GCPRO1 (value); \ | |
| 319 unbind_to_hairy (UNBIND_TO_count); \ | |
| 320 UNGCPRO; \ | |
| 321 break; \ | |
| 322 } \ | |
| 323 \ | |
| 324 sym->value = specpdl_ptr->old_value; \ | |
| 325 } \ | |
| 853 | 326 check_specbind_stack_sanity (); \ |
| 428 | 327 } while (0) |
| 328 | |
| 771 | 329 /* A slightly faster inline version of unbind_to_1, |
| 428 | 330 that doesn't offer GCPROing services. */ |
| 331 #define UNBIND_TO(count) do { \ | |
| 332 int UNBIND_TO_count = (count); \ | |
| 333 while (specpdl_depth_counter != UNBIND_TO_count) \ | |
| 334 { \ | |
| 440 | 335 Lisp_Symbol *sym; \ |
| 428 | 336 --specpdl_ptr; \ |
| 337 --specpdl_depth_counter; \ | |
| 338 \ | |
| 339 if (specpdl_ptr->func != 0 || \ | |
| 340 ((sym = XSYMBOL (specpdl_ptr->symbol)), \ | |
| 341 SYMBOL_VALUE_MAGIC_P (sym->value))) \ | |
| 342 { \ | |
| 343 unbind_to_hairy (UNBIND_TO_count); \ | |
| 344 break; \ | |
| 345 } \ | |
| 346 \ | |
| 347 sym->value = specpdl_ptr->old_value; \ | |
| 348 } \ | |
| 853 | 349 check_specbind_stack_sanity (); \ |
| 428 | 350 } while (0) |
| 351 | |
| 352 #if 0 | |
| 353 /* Unused. It's too hard to guarantee that the current bindings | |
| 354 contain only variables. */ | |
| 771 | 355 /* Another inline version of unbind_to_1(). VALUE is GC-protected. |
| 428 | 356 Caller guarantees that: |
| 357 - all of the elements on the binding stack are variable bindings. | |
| 358 Else we crash. */ | |
| 359 #define UNBIND_TO_GCPRO_VARIABLES_ONLY(count, value) do { \ | |
| 360 int UNBIND_TO_count = (count); \ | |
| 361 while (specpdl_depth_counter != UNBIND_TO_count) \ | |
| 362 { \ | |
| 440 | 363 Lisp_Symbol *sym; \ |
| 428 | 364 --specpdl_ptr; \ |
| 365 --specpdl_depth_counter; \ | |
| 366 \ | |
| 367 sym = XSYMBOL (specpdl_ptr->symbol); \ | |
| 368 if (!SYMBOL_VALUE_MAGIC_P (sym->value)) \ | |
| 369 sym->value = specpdl_ptr->old_value; \ | |
| 370 else \ | |
| 371 { \ | |
| 372 struct gcpro gcpro1; \ | |
| 373 GCPRO1 (value); \ | |
| 374 unbind_to_hairy (UNBIND_TO_count); \ | |
| 375 UNGCPRO; \ | |
| 376 break; \ | |
| 377 } \ | |
| 378 } \ | |
| 379 } while (0) | |
| 380 #endif /* unused */ | |
| 381 | |
| 382 /* A faster, but less safe inline version of Fset(). | |
| 383 Caller guarantees that: | |
| 384 - SYMBOL is a non-constant symbol (i.e. not Qnil, Qt, or keyword). | |
| 385 Else we crash. */ | |
| 386 #define FSET_FAST_UNSAFE(sym, newval) do { \ | |
| 387 Lisp_Object FFU_sym = (sym); \ | |
| 388 Lisp_Object FFU_newval = (newval); \ | |
| 440 | 389 Lisp_Symbol *FFU_symbol = XSYMBOL (FFU_sym); \ |
| 428 | 390 Lisp_Object FFU_oldval = FFU_symbol->value; \ |
| 391 if (!SYMBOL_VALUE_MAGIC_P (FFU_oldval) || UNBOUNDP (FFU_oldval)) \ | |
| 392 FFU_symbol->value = FFU_newval; \ | |
| 393 else \ | |
| 394 Fset (FFU_sym, FFU_newval); \ | |
| 395 } while (0) | |
| 396 | |
| 1292 | 397 /* Note: you must always fill in all of the fields in a backtrace structure |
| 398 before pushing them on the backtrace_list. The profiling code depends | |
| 399 on this. */ | |
| 400 | |
| 401 #define PUSH_BACKTRACE(bt) do { \ | |
| 402 (bt).next = backtrace_list; \ | |
| 403 backtrace_list = &(bt); \ | |
| 404 } while (0) | |
| 405 | |
| 406 #define POP_BACKTRACE(bt) do { \ | |
| 407 backtrace_list = (bt).next; \ | |
| 408 } while (0) | |
| 409 | |
| 440 | 410 #endif /* INCLUDED_backtrace_h_ */ |