smatch_slist.c

   1 /*
   2  * sparse/smatch_slist.c
   3  *
   4  * Copyright (C) 2008,2009 Dan Carpenter.
   5  *
   6  * Licensed under the Open Software License version 1.1
   7  *
   8  */
   9
  10 #include <stdlib.h>
  11 #include <stdio.h>
  12 #include "smatch.h"
  13 #include "smatch_slist.h"
  14
  15 #undef CHECKORDER
  16
  17 ALLOCATOR(smatch_state, "smatch state");
  18 ALLOCATOR(sm_state, "sm state");
  19 ALLOCATOR(named_slist, "named slist");
  20 __DO_ALLOCATOR(char, 0, 1, "state names", sname);
  21
  22 static int sm_state_counter;
  23
  24 char *show_sm(struct sm_state *sm)
  25 {
  26         static char buf[256];
  27         struct sm_state *tmp;
  28         int pos;
  29         int i;
  30
  31         pos = snprintf(buf, sizeof(buf), "[%s] '%s' = %s (",
  32                        check_name(sm->owner), sm->name, show_state(sm->state));
  33         if (pos > sizeof(buf))
  34                 goto truncate;
  35
  36         i = 0;
  37         FOR_EACH_PTR(sm->possible, tmp) {
  38                 if (i++)
  39                         pos += snprintf(buf + pos, sizeof(buf) - pos, ", ");
  40                 if (pos > sizeof(buf))
  41                         goto truncate;
  42                 pos += snprintf(buf + pos, sizeof(buf) - pos, "%s",
  43                                show_state(tmp->state));
  44                 if (pos > sizeof(buf))
  45                         goto truncate;
  46         } END_FOR_EACH_PTR(tmp);
  47         snprintf(buf + pos, sizeof(buf) - pos, ")");
  48
  49         return buf;
  50
  51 truncate:
  52         for (i = 0; i < 3; i++)
  53                 buf[sizeof(buf) - 2 - i] = '.';
  54         return buf;
  55 }
  56
  57 void __print_slist(struct state_list *slist)
  58 {
  59         struct sm_state *sm;
  60
  61         printf("dumping slist at %d\n", get_lineno());
  62         FOR_EACH_PTR(slist, sm) {
  63                 printf("%s\n", show_sm(sm));
  64         } END_FOR_EACH_PTR(sm);
  65         printf("---\n");
  66 }
  67
  68 /* NULL states go at the end to simplify merge_slist */
  69 int cmp_tracker(const struct sm_state *a, const struct sm_state *b)
  70 {
  71         int ret;
  72
  73         if (a == b)
  74                 return 0;
  75         if (!b)
  76                 return -1;
  77         if (!a)
  78                 return 1;
  79
  80         if (a->owner > b->owner)
  81                 return -1;
  82         if (a->owner < b->owner)
  83                 return 1;
  84
  85         ret = strcmp(a->name, b->name);
  86         if (ret)
  87                 return ret;
  88
  89         if (!b->sym && a->sym)
  90                 return -1;
  91         if (!a->sym && b->sym)
  92                 return 1;
  93         if (a->sym > b->sym)
  94                 return -1;
  95         if (a->sym < b->sym)
  96                 return 1;
  97
  98         return 0;
  99 }
 100
 101 static int cmp_sm_states(const struct sm_state *a, const struct sm_state *b)
 102 {
 103         int ret;
 104
 105         ret = cmp_tracker(a, b);
 106         if (ret)
 107                 return ret;
 108
 109         /* todo:  add hook for smatch_extra.c */
 110         if (a->state > b->state)
 111                 return -1;
 112         if (a->state < b->state)
 113                 return 1;
 114         return 0;
 115 }
 116
 117 static struct sm_state *alloc_sm_state(int owner, const char *name,
 118                              struct symbol *sym, struct smatch_state *state)
 119 {
 120         struct sm_state *sm_state = __alloc_sm_state(0);
 121
 122         sm_state_counter++;
 123
 124         sm_state->name = alloc_sname(name);
 125         sm_state->owner = owner;
 126         sm_state->sym = sym;
 127         sm_state->state = state;
 128         sm_state->line = get_lineno();
 129         sm_state->merged = 0;
 130         sm_state->implied = 0;
 131         sm_state->pool = NULL;
 132         sm_state->left = NULL;
 133         sm_state->right = NULL;
 134         sm_state->nr_children = 1;
 135         sm_state->possible = NULL;
 136         add_ptr_list(&sm_state->possible, sm_state);
 137         return sm_state;
 138 }
 139
 140 static struct sm_state *alloc_state_no_name(int owner, const char *name,
 141                                      struct symbol *sym,
 142                                      struct smatch_state *state)
 143 {
 144         struct sm_state *tmp;
 145
 146         tmp = alloc_sm_state(owner, NULL, sym, state);
 147         tmp->name = name;
 148         return tmp;
 149 }
 150
 151 void add_sm_state_slist(struct state_list **slist, struct sm_state *new)
 152 {
 153         struct sm_state *tmp;
 154
 155         FOR_EACH_PTR(*slist, tmp) {
 156                 if (cmp_sm_states(tmp, new) < 0)
 157                         continue;
 158                 else if (cmp_sm_states(tmp, new) == 0) {
 159                         return;
 160                 } else {
 161                         INSERT_CURRENT(new, tmp);
 162                         return;
 163                 }
 164         } END_FOR_EACH_PTR(tmp);
 165         add_ptr_list(slist, new);
 166 }
 167
 168 static void copy_possibles(struct sm_state *to, struct sm_state *from)
 169 {
 170         struct sm_state *tmp;
 171         struct sm_state *tmp2;
 172
 173         FOR_EACH_PTR(from->possible, tmp) {
 174                 tmp2 = alloc_state_no_name(tmp->owner, tmp->name, tmp->sym,
 175                                            tmp->state);
 176                 tmp2->line = tmp->line;
 177                 add_sm_state_slist(&to->possible, tmp2);
 178         } END_FOR_EACH_PTR(tmp);
 179 }
 180
 181 char *alloc_sname(const char *str)
 182 {
 183         char *tmp;
 184
 185         if (!str)
 186                 return NULL;
 187         tmp = __alloc_sname(strlen(str) + 1);
 188         strcpy(tmp, str);
 189         return tmp;
 190 }
 191
 192 int out_of_memory()
 193 {
 194         /*
 195          * I decided to use 50M here based on trial and error.
 196          * It works out OK for the kernel and so it should work
 197          * for most other projects as well.
 198          */
 199         if (sm_state_counter * sizeof(struct sm_state) >= 50000000)
 200                 return 1;
 201         return 0;
 202 }
 203
 204 static void free_sm_state(struct sm_state *sm)
 205 {
 206         free_slist(&sm->possible);
 207         /*
 208          * fixme.  Free the actual state.
 209          * Right now we leave it until the end of the function
 210          * because we don't want to double free it.
 211          * Use the freelist to not double free things
 212          */
 213 }
 214
 215 static void free_all_sm_states(struct allocation_blob *blob)
 216 {
 217         unsigned int size = sizeof(struct sm_state);
 218         unsigned int offset = 0;
 219
 220         while (offset < blob->offset) {
 221                 free_sm_state((struct sm_state *)(blob->data + offset));
 222                 offset += size;
 223         }
 224 }
 225
 226 /* At the end of every function we free all the sm_states */
 227 void free_every_single_sm_state(void)
 228 {
 229         struct allocator_struct *desc = &sm_state_allocator;
 230         struct allocation_blob *blob = desc->blobs;
 231
 232         desc->blobs = NULL;
 233         desc->allocations = 0;
 234         desc->total_bytes = 0;
 235         desc->useful_bytes = 0;
 236         desc->freelist = NULL;
 237         while (blob) {
 238                 struct allocation_blob *next = blob->next;
 239                 free_all_sm_states(blob);
 240                 blob_free(blob, desc->chunking);
 241                 blob = next;
 242         }
 243         clear_sname_alloc();
 244
 245         sm_state_counter = 0;
 246 }
 247
 248 struct sm_state *clone_sm(struct sm_state *s)
 249 {
 250         struct sm_state *ret;
 251
 252         ret = alloc_state_no_name(s->owner, s->name, s->sym, s->state);
 253         ret->merged = s->merged;
 254         ret->implied = s->implied;
 255         ret->line = s->line;
 256         /* clone_sm() doesn't copy the pools.  Each state needs to have
 257            only one pool. */
 258         ret->possible = clone_slist(s->possible);
 259         ret->left = s->left;
 260         ret->right = s->right;
 261         ret->nr_children = s->nr_children;
 262         return ret;
 263 }
 264
 265 int is_merged(struct sm_state *sm)
 266 {
 267         return sm->merged;
 268 }
 269
 270 int is_implied(struct sm_state *sm)
 271 {
 272         return sm->implied;
 273 }
 274
 275 int slist_has_state(struct state_list *slist, struct smatch_state *state)
 276 {
 277         struct sm_state *tmp;
 278
 279         FOR_EACH_PTR(slist, tmp) {
 280                 if (tmp->state == state)
 281                         return 1;
 282         } END_FOR_EACH_PTR(tmp);
 283         return 0;
 284 }
 285
 286 static void check_order(struct state_list *slist)
 287 {
 288 #ifdef CHECKORDER
 289         struct sm_state *sm;
 290         struct sm_state *last = NULL;
 291         int printed = 0;
 292
 293         FOR_EACH_PTR(slist, sm) {
 294                 if (last && cmp_tracker(sm, last) <= 0) {
 295                         printf("Error.  Unsorted slist %d vs %d, %p vs %p, "
 296                                "%s vs %s\n", last->owner, sm->owner,
 297                                last->sym, sm->sym, last->name, sm->name);
 298                         printed = 1;
 299                 }
 300                 last = state;
 301         } END_FOR_EACH_PTR(sm);
 302
 303         if (printed)
 304                 printf("======\n");
 305 #endif
 306 }
 307
 308 struct state_list *clone_slist(struct state_list *from_slist)
 309 {
 310         struct sm_state *sm;
 311         struct state_list *to_slist = NULL;
 312
 313         FOR_EACH_PTR(from_slist, sm) {
 314                 add_ptr_list(&to_slist, sm);
 315         } END_FOR_EACH_PTR(sm);
 316         check_order(to_slist);
 317         return to_slist;
 318 }
 319
 320 struct state_list_stack *clone_stack(struct state_list_stack *from_stack)
 321 {
 322         struct state_list *slist;
 323         struct state_list_stack *to_stack = NULL;
 324
 325         FOR_EACH_PTR(from_stack, slist) {
 326                 push_slist(&to_stack, slist);
 327         } END_FOR_EACH_PTR(slist);
 328         return to_stack;
 329 }
 330
 331 struct smatch_state *merge_states(int owner, const char *name,
 332                                   struct symbol *sym,
 333                                   struct smatch_state *state1,
 334                                   struct smatch_state *state2)
 335 {
 336         struct smatch_state *ret;
 337
 338         if (state1 == state2)
 339                 ret = state1;
 340         else if (__has_merge_function(owner))
 341                 ret = __client_merge_function(owner, name, sym, state1, state2);
 342         else if (!state1 || !state2)
 343                 ret = &undefined;
 344         else
 345                 ret = &merged;
 346         return ret;
 347 }
 348
 349 struct sm_state *merge_sm_states(struct sm_state *one, struct sm_state *two)
 350 {
 351         struct smatch_state *s;
 352         struct sm_state *result;
 353
 354         if (one == two)
 355                 return one;
 356         s = merge_states(one->owner, one->name, one->sym, one->state, two->state);
 357         result = alloc_state_no_name(one->owner, one->name, one->sym, s);
 358         result->merged = 1;
 359         result->left = one;
 360         result->right = two;
 361         result->nr_children = one->nr_children + two->nr_children;
 362         copy_possibles(result, one);
 363         copy_possibles(result, two);
 364
 365         if (option_debug) {
 366                 struct sm_state *tmp;
 367                 int i = 0;
 368
 369                 printf("%d merge name='%s' [%s] %s(L %d) + %s(L %d) => %s (",
 370                         get_lineno(), one->name, check_name(one->owner),
 371                         show_state(one->state), one->line,
 372                         show_state(two->state), two->line,
 373                         show_state(s));
 374
 375                 FOR_EACH_PTR(result->possible, tmp) {
 376                         if (i++)
 377                                 printf(", ");
 378                         printf("%s", show_state(tmp->state));
 379                 } END_FOR_EACH_PTR(tmp);
 380                 printf(")\n");
 381         }
 382
 383         return result;
 384 }
 385
 386 struct sm_state *get_sm_state_slist(struct state_list *slist, int owner, const char *name,
 387                                 struct symbol *sym)
 388 {
 389         struct sm_state *sm;
 390
 391         if (!name)
 392                 return NULL;
 393
 394         FOR_EACH_PTR(slist, sm) {
 395                 if (sm->owner == owner && sm->sym == sym && !strcmp(sm->name, name))
 396                         return sm;
 397         } END_FOR_EACH_PTR(sm);
 398         return NULL;
 399 }
 400
 401 struct smatch_state *get_state_slist(struct state_list *slist,
 402                                 int owner, const char *name,
 403                                 struct symbol *sym)
 404 {
 405         struct sm_state *sm;
 406
 407         sm = get_sm_state_slist(slist, owner, name, sym);
 408         if (sm)
 409                 return sm->state;
 410         return NULL;
 411 }
 412
 413 void overwrite_sm_state(struct state_list **slist, struct sm_state *new)
 414 {
 415         struct sm_state *tmp;
 416
 417         FOR_EACH_PTR(*slist, tmp) {
 418                 if (cmp_tracker(tmp, new) < 0)
 419                         continue;
 420                 else if (cmp_tracker(tmp, new) == 0) {
 421                         REPLACE_CURRENT_PTR(tmp, new);
 422                         return;
 423                 } else {
 424                         INSERT_CURRENT(new, tmp);
 425                         return;
 426                 }
 427         } END_FOR_EACH_PTR(tmp);
 428         add_ptr_list(slist, new);
 429 }
 430
 431 void overwrite_sm_state_stack(struct state_list_stack **stack,
 432                         struct sm_state *sm)
 433 {
 434         struct state_list *slist;
 435
 436         slist = pop_slist(stack);
 437         overwrite_sm_state(&slist, sm);
 438         push_slist(stack, slist);
 439 }
 440
 441 struct sm_state *set_state_slist(struct state_list **slist, int owner, const char *name,
 442                      struct symbol *sym, struct smatch_state *state)
 443 {
 444         struct sm_state *tmp;
 445         struct sm_state *new = alloc_sm_state(owner, name, sym, state);
 446
 447         FOR_EACH_PTR(*slist, tmp) {
 448                 if (cmp_tracker(tmp, new) < 0)
 449                         continue;
 450                 else if (cmp_tracker(tmp, new) == 0) {
 451                         REPLACE_CURRENT_PTR(tmp, new);
 452                         return new;
 453                 } else {
 454                         INSERT_CURRENT(new, tmp);
 455                         return new;
 456                 }
 457         } END_FOR_EACH_PTR(tmp);
 458         add_ptr_list(slist, new);
 459         return new;
 460 }
 461
 462 void delete_state_slist(struct state_list **slist, int owner, const char *name,
 463                         struct symbol *sym)
 464 {
 465         struct sm_state *sm;
 466
 467         FOR_EACH_PTR(*slist, sm) {
 468                 if (sm->owner == owner && sm->sym == sym && !strcmp(sm->name, name)) {
 469                         DELETE_CURRENT_PTR(sm);
 470                         return;
 471                 }
 472         } END_FOR_EACH_PTR(sm);
 473 }
 474
 475 void delete_state_stack(struct state_list_stack **stack, int owner, const char *name,
 476                         struct symbol *sym)
 477 {
 478         struct state_list *slist;
 479
 480         slist = pop_slist(stack);
 481         delete_state_slist(&slist, owner, name, sym);
 482         push_slist(stack, slist);
 483 }
 484
 485 void push_slist(struct state_list_stack **list_stack, struct state_list *slist)
 486 {
 487         add_ptr_list(list_stack, slist);
 488 }
 489
 490 struct state_list *pop_slist(struct state_list_stack **list_stack)
 491 {
 492         struct state_list *slist;
 493
 494         slist = last_ptr_list((struct ptr_list *)*list_stack);
 495         delete_ptr_list_last((struct ptr_list **)list_stack);
 496         return slist;
 497 }
 498
 499 void free_slist(struct state_list **slist)
 500 {
 501         __free_ptr_list((struct ptr_list **)slist);
 502 }
 503
 504 void free_stack(struct state_list_stack **stack)
 505 {
 506         __free_ptr_list((struct ptr_list **)stack);
 507 }
 508
 509 void free_stack_and_slists(struct state_list_stack **slist_stack)
 510 {
 511         struct state_list *slist;
 512
 513         FOR_EACH_PTR(*slist_stack, slist) {
 514                 free_slist(&slist);
 515         } END_FOR_EACH_PTR(slist);
 516         free_stack(slist_stack);
 517 }
 518
 519 /*
 520  * set_state_stack() sets the state for the top slist on the stack.
 521  */
 522 struct sm_state *set_state_stack(struct state_list_stack **stack, int owner, const char *name,
 523                                 struct symbol *sym, struct smatch_state *state)
 524 {
 525         struct state_list *slist;
 526         struct sm_state *sm;
 527
 528         slist = pop_slist(stack);
 529         sm = set_state_slist(&slist, owner, name, sym, state);
 530         push_slist(stack, slist);
 531
 532         return sm;
 533 }
 534
 535 /*
 536  * get_sm_state_stack() gets the state for the top slist on the stack.
 537  */
 538 struct sm_state *get_sm_state_stack(struct state_list_stack *stack,
 539                                 int owner, const char *name,
 540                                 struct symbol *sym)
 541 {
 542         struct state_list *slist;
 543         struct sm_state *ret;
 544
 545         slist = pop_slist(&stack);
 546         ret = get_sm_state_slist(slist, owner, name, sym);
 547         push_slist(&stack, slist);
 548         return ret;
 549 }
 550
 551 struct smatch_state *get_state_stack(struct state_list_stack *stack,
 552                                 int owner, const char *name,
 553                                 struct symbol *sym)
 554 {
 555         struct sm_state *sm;
 556
 557         sm = get_sm_state_stack(stack, owner, name, sym);
 558         if (sm)
 559                 return sm->state;
 560         return NULL;
 561 }
 562
 563 static void match_states(struct state_list **one, struct state_list **two)
 564 {
 565         struct sm_state *one_sm;
 566         struct sm_state *two_sm;
 567         struct sm_state *tmp;
 568         struct smatch_state *tmp_state;
 569         struct state_list *add_to_one = NULL;
 570         struct state_list *add_to_two = NULL;
 571
 572         PREPARE_PTR_LIST(*one, one_sm);
 573         PREPARE_PTR_LIST(*two, two_sm);
 574         for (;;) {
 575                 if (!one_sm && !two_sm)
 576                         break;
 577                 if (cmp_tracker(one_sm, two_sm) < 0) {
 578                         tmp_state = __client_unmatched_state_function(one_sm);
 579                         tmp = alloc_state_no_name(one_sm->owner, one_sm->name,
 580                                                   one_sm->sym, tmp_state);
 581                         add_ptr_list(&add_to_two, tmp);
 582                         NEXT_PTR_LIST(one_sm);
 583                 } else if (cmp_tracker(one_sm, two_sm) == 0) {
 584                         NEXT_PTR_LIST(one_sm);
 585                         NEXT_PTR_LIST(two_sm);
 586                 } else {
 587                         tmp_state = __client_unmatched_state_function(two_sm);
 588                         tmp = alloc_state_no_name(two_sm->owner, two_sm->name,
 589                                                   two_sm->sym, tmp_state);
 590                         add_ptr_list(&add_to_one, tmp);
 591                         NEXT_PTR_LIST(two_sm);
 592                 }
 593         }
 594         FINISH_PTR_LIST(two_sm);
 595         FINISH_PTR_LIST(one_sm);
 596
 597         overwrite_slist(add_to_one, one);
 598         overwrite_slist(add_to_two, two);
 599 }
 600
 601 static void clone_pool_havers(struct state_list *slist)
 602 {
 603         struct sm_state *sm;
 604         struct sm_state *new;
 605
 606         FOR_EACH_PTR(slist, sm) {
 607                 if (sm->pool) {
 608                         new = clone_sm(sm);
 609                         REPLACE_CURRENT_PTR(sm, new);
 610                 }
 611         } END_FOR_EACH_PTR(sm);
 612 }
 613
 614 /*
 615  * merge_slist() is called whenever paths merge, such as after
 616  * an if statement.  It takes the two slists and creates one.
 617  */
 618 void merge_slist(struct state_list **to, struct state_list *slist)
 619 {
 620         struct sm_state *one_sm, *two_sm, *tmp;
 621         struct state_list *results = NULL;
 622         struct state_list *implied_one = NULL;
 623         struct state_list *implied_two = NULL;
 624
 625         if (out_of_memory())
 626                 return;
 627
 628         check_order(*to);
 629         check_order(slist);
 630
 631         /* merging a null and nonnull path gives you only the nonnull path */
 632         if (!slist)
 633                 return;
 634
 635         if (!*to) {
 636                 *to = clone_slist(slist);
 637                 return;
 638         }
 639
 640         implied_one = clone_slist(*to);
 641         implied_two = clone_slist(slist);
 642
 643         match_states(&implied_one, &implied_two);
 644
 645         clone_pool_havers(implied_one);
 646         clone_pool_havers(implied_two);
 647
 648         PREPARE_PTR_LIST(implied_one, one_sm);
 649         PREPARE_PTR_LIST(implied_two, two_sm);
 650         for (;;) {
 651                 if (!one_sm && !two_sm)
 652                         break;
 653                 if (cmp_tracker(one_sm, two_sm) < 0) {
 654                         sm_msg("error:  Internal smatch error.");
 655                         NEXT_PTR_LIST(one_sm);
 656                 } else if (cmp_tracker(one_sm, two_sm) == 0) {
 657                         if (one_sm != two_sm) {
 658                                 one_sm->pool = implied_one;
 659                                 two_sm->pool = implied_two;
 660                         }
 661
 662                         tmp = merge_sm_states(one_sm, two_sm);
 663                         add_ptr_list(&results, tmp);
 664                         NEXT_PTR_LIST(one_sm);
 665                         NEXT_PTR_LIST(two_sm);
 666                 } else {
 667                         sm_msg("error:  Internal smatch error.");
 668                         NEXT_PTR_LIST(two_sm);
 669                 }
 670         }
 671         FINISH_PTR_LIST(two_sm);
 672         FINISH_PTR_LIST(one_sm);
 673
 674         free_slist(to);
 675         *to = results;
 676 }
 677
 678 /*
 679  * filter_slist() removes any sm states "slist" holds in common with "filter"
 680  */
 681 void filter_slist(struct state_list **slist, struct state_list *filter)
 682 {
 683         struct sm_state *one_sm, *two_sm;
 684         struct state_list *results = NULL;
 685
 686         PREPARE_PTR_LIST(*slist, one_sm);
 687         PREPARE_PTR_LIST(filter, two_sm);
 688         for (;;) {
 689                 if (!one_sm && !two_sm)
 690                         break;
 691                 if (cmp_tracker(one_sm, two_sm) < 0) {
 692                         add_ptr_list(&results, one_sm);
 693                         NEXT_PTR_LIST(one_sm);
 694                 } else if (cmp_tracker(one_sm, two_sm) == 0) {
 695                         if (one_sm != two_sm)
 696                                 add_ptr_list(&results, one_sm);
 697                         NEXT_PTR_LIST(one_sm);
 698                         NEXT_PTR_LIST(two_sm);
 699                 } else {
 700                         NEXT_PTR_LIST(two_sm);
 701                 }
 702         }
 703         FINISH_PTR_LIST(two_sm);
 704         FINISH_PTR_LIST(one_sm);
 705
 706         free_slist(slist);
 707         *slist = results;
 708 }
 709
 710 /*
 711  * and_slist_stack() pops the top two slists, overwriting the one with
 712  * the other and pushing it back on the stack.
 713  */
 714 void and_slist_stack(struct state_list_stack **slist_stack)
 715 {
 716         struct sm_state *tmp;
 717         struct state_list *right_slist = pop_slist(slist_stack);
 718
 719         FOR_EACH_PTR(right_slist, tmp) {
 720                 overwrite_sm_state_stack(slist_stack, tmp);
 721         } END_FOR_EACH_PTR(tmp);
 722         free_slist(&right_slist);
 723 }
 724
 725 /*
 726  * or_slist_stack() is for if we have:  if (foo || bar) { foo->baz;
 727  * It pops the two slists from the top of the stack and merges them
 728  * together in a way that preserves the things they have in common
 729  * but creates a merged state for most of the rest.
 730  * You could have code that had:  if (foo || foo) { foo->baz;
 731  * It's this function which ensures smatch does the right thing.
 732  */
 733 void or_slist_stack(struct state_list_stack **pre_conds,
 734                     struct state_list *cur_slist,
 735                     struct state_list_stack **slist_stack)
 736 {
 737         struct state_list *new;
 738         struct state_list *old;
 739         struct state_list *pre_slist;
 740         struct state_list *res;
 741         struct state_list *tmp_slist;
 742
 743         new = pop_slist(slist_stack);
 744         old = pop_slist(slist_stack);
 745
 746         pre_slist = pop_slist(pre_conds);
 747         push_slist(pre_conds, clone_slist(pre_slist));
 748
 749         res = clone_slist(pre_slist);
 750         overwrite_slist(old, &res);
 751
 752         tmp_slist = clone_slist(cur_slist);
 753         overwrite_slist(new, &tmp_slist);
 754
 755         merge_slist(&res, tmp_slist);
 756         filter_slist(&res, pre_slist);
 757
 758         push_slist(slist_stack, res);
 759         free_slist(&tmp_slist);
 760         free_slist(&pre_slist);
 761         free_slist(&new);
 762         free_slist(&old);
 763 }
 764
 765 /*
 766  * get_slist_from_named_stack() is only used for gotos.
 767  */
 768 struct state_list **get_slist_from_named_stack(struct named_stack *stack,
 769                                               const char *name)
 770 {
 771         struct named_slist *tmp;
 772
 773         FOR_EACH_PTR(stack, tmp) {
 774                 if (!strcmp(tmp->name, name))
 775                         return &tmp->slist;
 776         } END_FOR_EACH_PTR(tmp);
 777         return NULL;
 778 }
 779
 780 void overwrite_slist(struct state_list *from, struct state_list **to)
 781 {
 782         struct sm_state *tmp;
 783
 784         FOR_EACH_PTR(from, tmp) {
 785                 overwrite_sm_state(to, tmp);
 786         } END_FOR_EACH_PTR(tmp);
 787 }