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 void __print_slist(struct state_list *slist)
  23 {
  24         struct sm_state *state;
  25         struct sm_state *poss;
  26         int i;
  27
  28         printf("dumping slist at %d\n", get_lineno());
  29         FOR_EACH_PTR(slist, state) {
  30                 printf("%d '%s'=%s (", state->owner, state->name,
  31                         show_state(state->state));
  32                 i = 0;
  33                 FOR_EACH_PTR(state->possible, poss) {
  34                         if (i++)
  35                                 printf(", ");
  36                         printf("%s", show_state(poss->state));
  37                 } END_FOR_EACH_PTR(poss);
  38                 printf(")\n");
  39         } END_FOR_EACH_PTR(state);
  40         printf("---\n");
  41 }
  42
  43
  44 /* NULL states go at the end to simplify merge_slist */
  45 int cmp_tracker(const struct sm_state *a, const struct sm_state *b)
  46 {
  47         int ret;
  48
  49         if (a == b)
  50                 return 0;
  51         if (!b)
  52                 return -1;
  53         if (!a)
  54                 return 1;
  55
  56         if (a->owner > b->owner)
  57                 return -1;
  58         if (a->owner < b->owner)
  59                 return 1;
  60
  61         ret = strcmp(a->name, b->name);
  62         if (ret)
  63                 return ret;
  64
  65         if (!b->sym && a->sym)
  66                 return -1;
  67         if (!a->sym && b->sym)
  68                 return 1;
  69         if (a->sym > b->sym)
  70                 return -1;
  71         if (a->sym < b->sym)
  72                 return 1;
  73
  74         return 0;
  75 }
  76
  77 static int cmp_sm_states(const struct sm_state *a, const struct sm_state *b)
  78 {
  79         int ret;
  80
  81         ret = cmp_tracker(a, b);
  82         if (ret)
  83                 return ret;
  84
  85         /* todo:  add hook for smatch_extra.c */
  86         if (a->state > b->state)
  87                 return -1;
  88         if (a->state < b->state)
  89                 return 1;
  90         return 0;
  91 }
  92
  93 static struct sm_state *alloc_state_no_name(const char *name, int owner,
  94                                      struct symbol *sym,
  95                                      struct smatch_state *state)
  96 {
  97         struct sm_state *tmp;
  98
  99         tmp = alloc_state(NULL, owner, sym, state);
 100         tmp->name = name;
 101         return tmp;
 102 }
 103
 104 void add_sm_state_slist(struct state_list **slist, struct sm_state *new)
 105 {
 106         struct sm_state *tmp;
 107
 108         FOR_EACH_PTR(*slist, tmp) {
 109                 if (cmp_sm_states(tmp, new) < 0)
 110                         continue;
 111                 else if (cmp_sm_states(tmp, new) == 0) {
 112                         return;
 113                 } else {
 114                         INSERT_CURRENT(new, tmp);
 115                         return;
 116                 }
 117         } END_FOR_EACH_PTR(tmp);
 118         add_ptr_list(slist, new);
 119 }
 120
 121 static void add_possible(struct sm_state *sm, struct sm_state *new)
 122 {
 123         struct sm_state *tmp;
 124         struct sm_state *tmp2;
 125
 126         if (!new) {
 127                 struct smatch_state *s;
 128
 129                 s = merge_states(sm->name, sm->owner, sm->sym, sm->state, NULL);
 130                 tmp = alloc_state_no_name(sm->name, sm->owner, sm->sym, s);
 131                 add_sm_state_slist(&sm->possible, tmp);
 132                 return;
 133         }
 134
 135         FOR_EACH_PTR(new->possible, tmp) {
 136                 tmp2 = alloc_state_no_name(tmp->name, tmp->owner, tmp->sym,
 137                                            tmp->state);
 138                 add_sm_state_slist(&sm->possible, tmp2);
 139         } END_FOR_EACH_PTR(tmp);
 140 }
 141
 142 char *alloc_sname(const char *str)
 143 {
 144         char *tmp;
 145
 146         if (!str)
 147                 return NULL;
 148         tmp = __alloc_sname(strlen(str) + 1);
 149         strcpy(tmp, str);
 150         return tmp;
 151 }
 152
 153 struct sm_state *alloc_state(const char *name, int owner,
 154                              struct symbol *sym, struct smatch_state *state)
 155 {
 156         struct sm_state *sm_state = __alloc_sm_state(0);
 157
 158         sm_state->name = alloc_sname(name);
 159         sm_state->owner = owner;
 160         sm_state->sym = sym;
 161         sm_state->state = state;
 162         sm_state->line = get_lineno();
 163         sm_state->merged = 0;
 164         sm_state->my_pools = NULL;
 165         sm_state->pre_left = NULL;
 166         sm_state->pre_right = NULL;
 167         sm_state->possible = NULL;
 168         add_ptr_list(&sm_state->possible, sm_state);
 169         return sm_state;
 170 }
 171
 172 static void free_sm_state(struct sm_state *sm)
 173 {
 174         free_slist(&sm->possible);
 175         free_stack(&sm->my_pools);
 176         /*
 177          * fixme.  Free the actual state.
 178          * Right now we leave it until the end of the function
 179          * because we don't want to double free it.
 180          * Use the freelist to not double free things
 181          */
 182 }
 183
 184 static void free_all_sm_states(struct allocation_blob *blob)
 185 {
 186         unsigned int size = sizeof(struct sm_state);
 187         unsigned int offset = 0;
 188
 189         while (offset < blob->offset) {
 190                 free_sm_state((struct sm_state *)(blob->data + offset));
 191                 offset += size;
 192         }
 193 }
 194
 195 /* At the end of every function we free all the sm_states */
 196 void free_every_single_sm_state(void)
 197 {
 198         struct allocator_struct *desc = &sm_state_allocator;
 199         struct allocation_blob *blob = desc->blobs;
 200
 201         desc->blobs = NULL;
 202         desc->allocations = 0;
 203         desc->total_bytes = 0;
 204         desc->useful_bytes = 0;
 205         desc->freelist = NULL;
 206         while (blob) {
 207                 struct allocation_blob *next = blob->next;
 208                 free_all_sm_states(blob);
 209                 blob_free(blob, desc->chunking);
 210                 blob = next;
 211         }
 212         clear_sname_alloc();
 213 }
 214
 215 struct sm_state *clone_state(struct sm_state *s)
 216 {
 217         struct sm_state *ret;
 218
 219         ret = alloc_state_no_name(s->name, s->owner, s->sym, s->state);
 220         ret->line = s->line;
 221         ret->merged = s->merged;
 222         /* clone_state() doesn't copy the my_pools.  Each state needs to have
 223            only one my_pool. */
 224         ret->possible = clone_slist(s->possible);
 225         ret->pre_left = s->pre_left;
 226         ret->pre_right = s->pre_right;
 227         return ret;
 228 }
 229
 230 int is_merged(struct sm_state *sm)
 231 {
 232         return sm->merged;
 233 }
 234
 235 int slist_has_state(struct state_list *slist, struct smatch_state *state)
 236 {
 237         struct sm_state *tmp;
 238
 239         FOR_EACH_PTR(slist, tmp) {
 240                 if (tmp->state == state)
 241                         return 1;
 242         } END_FOR_EACH_PTR(tmp);
 243         return 0;
 244 }
 245
 246 static void check_order(struct state_list *slist)
 247 {
 248 #ifdef CHECKORDER
 249         struct sm_state *state;
 250         struct sm_state *last = NULL;
 251         int printed = 0;
 252
 253         FOR_EACH_PTR(slist, state) {
 254                 if (last && cmp_tracker(state, last) <= 0) {
 255                         printf("Error.  Unsorted slist %d vs %d, %p vs %p, "
 256                                "%s vs %s\n", last->owner, state->owner,
 257                                last->sym, state->sym, last->name, state->name);
 258                         printed = 1;
 259                 }
 260                 last = state;
 261         } END_FOR_EACH_PTR(state);
 262
 263         if (printed)
 264                 printf("======\n");
 265 #endif
 266 }
 267
 268 struct state_list *clone_slist(struct state_list *from_slist)
 269 {
 270         struct sm_state *state;
 271         struct state_list *to_slist = NULL;
 272
 273         FOR_EACH_PTR(from_slist, state) {
 274                 add_ptr_list(&to_slist, state);
 275         } END_FOR_EACH_PTR(state);
 276         check_order(to_slist);
 277         return to_slist;
 278 }
 279
 280 struct state_list *clone_slist_and_states(struct state_list *from_slist)
 281 {
 282         struct sm_state *state;
 283         struct sm_state *tmp;
 284         struct state_list *to_slist = NULL;
 285
 286         FOR_EACH_PTR(from_slist, state) {
 287                 tmp = clone_state(state);
 288                 add_ptr_list(&to_slist, tmp);
 289         } END_FOR_EACH_PTR(state);
 290         check_order(to_slist);
 291         return to_slist;
 292 }
 293
 294 struct state_list_stack *clone_stack(struct state_list_stack *from_stack)
 295 {
 296         struct state_list *slist;
 297         struct state_list_stack *to_stack = NULL;
 298
 299         FOR_EACH_PTR(from_stack, slist) {
 300                 push_slist(&to_stack, slist);
 301         } END_FOR_EACH_PTR(slist);
 302         return to_stack;
 303 }
 304
 305 struct smatch_state *merge_states(const char *name, int owner,
 306                                   struct symbol *sym,
 307                                   struct smatch_state *state1,
 308                                   struct smatch_state *state2)
 309 {
 310         struct smatch_state *ret;
 311
 312         if (state1 == state2)
 313                 ret = state1;
 314         else if (__has_merge_function(owner))
 315                 ret = __client_merge_function(owner, name, sym, state1, state2);
 316         else if (!state1 || !state2)
 317                 ret = &undefined;
 318         else
 319                 ret = &merged;
 320         return ret;
 321 }
 322
 323 /*
 324  * add_pool() adds a slist to ->pools. If the slist has already been
 325  * added earlier then it doesn't get added a second time.
 326  */
 327 void add_pool(struct state_list_stack **pools, struct state_list *new)
 328 {
 329         struct state_list *tmp;
 330
 331         FOR_EACH_PTR(*pools, tmp) {
 332                 if (tmp < new)
 333                         continue;
 334                 else if (tmp == new) {
 335                         return;
 336                 } else {
 337                         INSERT_CURRENT(new, tmp);
 338                         return;
 339                 }
 340         } END_FOR_EACH_PTR(tmp);
 341         add_ptr_list(pools, new);
 342 }
 343
 344 void merge_pools(struct state_list_stack **to, struct state_list_stack *from)
 345 {
 346         struct state_list *tmp;
 347
 348         FOR_EACH_PTR(from, tmp) {
 349                 add_pool(to, tmp);
 350         } END_FOR_EACH_PTR(tmp);
 351 }
 352
 353 struct sm_state *merge_sm_states(struct sm_state *one, struct sm_state *two)
 354 {
 355         struct smatch_state *s;
 356         struct sm_state *result;
 357
 358         if (one == two)
 359                 return one;
 360         s = merge_states(one->name, one->owner, one->sym, one->state,
 361                         (two?two->state:NULL));
 362         result = alloc_state_no_name(one->name, one->owner, one->sym, s);
 363         if (two && one->line == two->line)
 364                 result->line = one->line;
 365         result->merged = 1;
 366         result->pre_left = one;
 367         result->pre_right = two;
 368         add_possible(result, one);
 369         add_possible(result, two);
 370
 371         if (debug_states) {
 372                 struct sm_state *tmp;
 373                 int i = 0;
 374
 375                 printf("%d merge name='%s' owner=%d: %s + %s => %s (",
 376                         get_lineno(), one->name, one->owner,
 377                         show_state(one->state), show_state(two?two->state:NULL),
 378                         show_state(s));
 379
 380                 FOR_EACH_PTR(result->possible, tmp) {
 381                         if (i++) {
 382                                 printf(", ");
 383                         }
 384                         printf("%s", show_state(tmp->state));
 385                 } END_FOR_EACH_PTR(tmp);
 386                 printf(")\n");
 387         }
 388
 389         return result;
 390 }
 391
 392 struct sm_state *get_sm_state_slist(struct state_list *slist, const char *name,
 393                                 int owner, struct symbol *sym)
 394 {
 395         struct sm_state *state;
 396
 397         if (!name)
 398                 return NULL;
 399
 400         FOR_EACH_PTR(slist, state) {
 401                 if (state->owner == owner && state->sym == sym
 402                     && !strcmp(state->name, name))
 403                         return state;
 404         } END_FOR_EACH_PTR(state);
 405         return NULL;
 406 }
 407
 408 struct smatch_state *get_state_slist(struct state_list *slist,
 409                                 const char *name, int owner,
 410                                 struct symbol *sym)
 411 {
 412         struct sm_state *state;
 413
 414         state = get_sm_state_slist(slist, name, owner, sym);
 415         if (state)
 416                 return state->state;
 417         return NULL;
 418 }
 419
 420 void overwrite_sm_state(struct state_list **slist, struct sm_state *new)
 421 {
 422         struct sm_state *tmp;
 423
 424         FOR_EACH_PTR(*slist, tmp) {
 425                 if (cmp_tracker(tmp, new) < 0)
 426                         continue;
 427                 else if (cmp_tracker(tmp, new) == 0) {
 428                         REPLACE_CURRENT_PTR(tmp, new);
 429                         return;
 430                 } else {
 431                         INSERT_CURRENT(new, tmp);
 432                         return;
 433                 }
 434         } END_FOR_EACH_PTR(tmp);
 435         add_ptr_list(slist, new);
 436 }
 437
 438 void overwrite_sm_state_stack(struct state_list_stack **stack,
 439                         struct sm_state *state)
 440 {
 441         struct state_list *slist;
 442
 443         slist = pop_slist(stack);
 444         overwrite_sm_state(&slist, state);
 445         push_slist(stack, slist);
 446 }
 447
 448 void set_state_slist(struct state_list **slist, const char *name, int owner,
 449                      struct symbol *sym, struct smatch_state *state)
 450 {
 451         struct sm_state *tmp;
 452         struct sm_state *new = alloc_state(name, owner, sym, state);
 453
 454         FOR_EACH_PTR(*slist, tmp) {
 455                 if (cmp_tracker(tmp, new) < 0)
 456                         continue;
 457                 else if (cmp_tracker(tmp, new) == 0) {
 458                         REPLACE_CURRENT_PTR(tmp, new);
 459                         return;
 460                 } else {
 461                         INSERT_CURRENT(new, tmp);
 462                         return;
 463                 }
 464         } END_FOR_EACH_PTR(tmp);
 465         add_ptr_list(slist, new);
 466 }
 467
 468 void delete_state_slist(struct state_list **slist, const char *name, int owner,
 469                         struct symbol *sym)
 470 {
 471         struct sm_state *state;
 472
 473         FOR_EACH_PTR(*slist, state) {
 474                 if (state->owner == owner && state->sym == sym
 475                     && !strcmp(state->name, name)){
 476                         DELETE_CURRENT_PTR(state);
 477                         return;
 478                 }
 479         } END_FOR_EACH_PTR(state);
 480 }
 481
 482
 483 void push_slist(struct state_list_stack **list_stack, struct state_list *slist)
 484 {
 485         add_ptr_list(list_stack, slist);
 486 }
 487
 488 struct state_list *pop_slist(struct state_list_stack **list_stack)
 489 {
 490         struct state_list *slist;
 491
 492         slist = last_ptr_list((struct ptr_list *)*list_stack);
 493         delete_ptr_list_last((struct ptr_list **)list_stack);
 494         return slist;
 495 }
 496
 497 void free_slist(struct state_list **slist)
 498 {
 499         __free_ptr_list((struct ptr_list **)slist);
 500 }
 501
 502 void free_stack(struct state_list_stack **stack)
 503 {
 504         __free_ptr_list((struct ptr_list **)stack);
 505 }
 506
 507 void free_stack_and_slists(struct state_list_stack **slist_stack)
 508 {
 509         struct state_list *slist;
 510
 511         FOR_EACH_PTR(*slist_stack, slist) {
 512                 free_slist(&slist);
 513         } END_FOR_EACH_PTR(slist);
 514         free_stack(slist_stack);
 515 }
 516
 517 /*
 518  * set_state_stack() sets the state for the top slist on the stack.
 519  */
 520 void set_state_stack(struct state_list_stack **stack, const char *name,
 521                      int owner, struct symbol *sym, struct smatch_state *state)
 522 {
 523         struct state_list *slist;
 524
 525         slist = pop_slist(stack);
 526         set_state_slist(&slist, name, owner, sym, state);
 527         push_slist(stack, slist);
 528 }
 529
 530 /*
 531  * get_sm_state_stack() gets the state for the top slist on the stack.
 532  */
 533 struct sm_state *get_sm_state_stack(struct state_list_stack *stack,
 534                                     const char *name, int owner,
 535                                     struct symbol *sym)
 536 {
 537         struct state_list *slist;
 538         struct sm_state *ret;
 539
 540         slist = pop_slist(&stack);
 541         ret = get_sm_state_slist(slist, name, owner, sym);
 542         push_slist(&stack, slist);
 543         return ret;
 544 }
 545
 546
 547 struct smatch_state *get_state_stack(struct state_list_stack *stack,
 548                                      const char *name, int owner,
 549                                      struct symbol *sym)
 550 {
 551         struct sm_state *state;
 552
 553         state = get_sm_state_stack(stack, name, owner, sym);
 554         if (state)
 555                 return state->state;
 556         return NULL;
 557 }
 558
 559 static void match_states(struct state_list **one, struct state_list **two)
 560 {
 561         struct sm_state *one_state;
 562         struct sm_state *two_state;
 563         struct sm_state *tmp;
 564         struct smatch_state *tmp_state;
 565         struct state_list *add_to_one = NULL;
 566         struct state_list *add_to_two = NULL;
 567
 568         PREPARE_PTR_LIST(*one, one_state);
 569         PREPARE_PTR_LIST(*two, two_state);
 570         for (;;) {
 571                 if (!one_state && !two_state)
 572                         break;
 573                 if (cmp_tracker(one_state, two_state) < 0) {
 574                         tmp_state = __client_unmatched_state_function(one_state);
 575                         tmp = alloc_state_no_name(one_state->name,
 576                                                   one_state->owner,
 577                                                   one_state->sym, tmp_state);
 578                         add_ptr_list(&add_to_two, tmp);
 579                         NEXT_PTR_LIST(one_state);
 580                 } else if (cmp_tracker(one_state, two_state) == 0) {
 581                         NEXT_PTR_LIST(one_state);
 582                         NEXT_PTR_LIST(two_state);
 583                 } else {
 584                         tmp_state = __client_unmatched_state_function(two_state);
 585                         tmp = alloc_state_no_name(two_state->name,
 586                                                   two_state->owner,
 587                                                   two_state->sym, tmp_state);
 588                         add_ptr_list(&add_to_one, tmp);
 589                         NEXT_PTR_LIST(two_state);
 590                 }
 591         }
 592         FINISH_PTR_LIST(two_state);
 593         FINISH_PTR_LIST(one_state);
 594
 595         overwrite_slist(add_to_one, one);
 596         overwrite_slist(add_to_two, two);
 597 }
 598
 599 static void clone_modified(struct state_list **one, struct state_list **two)
 600 {
 601         struct sm_state *one_state;
 602         struct sm_state *two_state;
 603         struct sm_state *clone;
 604         struct state_list *add_to_one = NULL;
 605         struct state_list *add_to_two = NULL;
 606
 607         PREPARE_PTR_LIST(*one, one_state);
 608         PREPARE_PTR_LIST(*two, two_state);
 609         for (;;) {
 610                 if (!one_state && !two_state)
 611                         break;
 612                 if (cmp_tracker(one_state, two_state) < 0) {
 613                         NEXT_PTR_LIST(one_state);
 614                 } else if (cmp_tracker(one_state, two_state) == 0) {
 615                         if (one_state != two_state) {
 616                                 clone = clone_state(one_state);
 617                                 add_ptr_list(&add_to_one, clone);
 618                                 clone = clone_state(two_state);
 619                                 add_ptr_list(&add_to_two, clone);
 620                         }
 621                         NEXT_PTR_LIST(one_state);
 622                         NEXT_PTR_LIST(two_state);
 623                 } else {
 624                         NEXT_PTR_LIST(two_state);
 625                 }
 626         }
 627         FINISH_PTR_LIST(two_state);
 628         FINISH_PTR_LIST(one_state);
 629
 630         overwrite_slist(add_to_one, one);
 631         overwrite_slist(add_to_two, two);
 632 }
 633
 634 static void clone_pool_havers(struct state_list *slist)
 635 {
 636         struct sm_state *state;
 637         struct sm_state *new;
 638
 639         FOR_EACH_PTR(slist, state) {
 640                 if (state->my_pools) {
 641                         new = clone_state(state);
 642                         REPLACE_CURRENT_PTR(state, new);
 643                 }
 644         } END_FOR_EACH_PTR(state);
 645 }
 646
 647 /*
 648  * merge_slist() is called whenever paths merge, such as after
 649  * an if statement.  It takes the two slists and creates one.
 650  */
 651 static void __merge_slist(struct state_list **to, struct state_list *slist, int clone)
 652 {
 653         struct sm_state *to_state, *state, *tmp;
 654         struct state_list *results = NULL;
 655         struct state_list *implied_to = NULL;
 656         struct state_list *implied_from = NULL;
 657
 658         check_order(*to);
 659         check_order(slist);
 660
 661         /* merging a null and nonnull path gives you only the nonnull path */
 662         if (!slist) {
 663                 return;
 664         }
 665         if (!*to) {
 666                 *to = clone_slist(slist);
 667                 return;
 668         }
 669
 670         implied_to = clone_slist(*to);
 671         implied_from = clone_slist(slist);
 672
 673         match_states(&implied_to, &implied_from);
 674         if (clone)
 675                 clone_modified(&implied_to, &implied_from);
 676         clone_pool_havers(implied_to);
 677         clone_pool_havers(implied_from);
 678
 679         PREPARE_PTR_LIST(implied_to, to_state);
 680         PREPARE_PTR_LIST(implied_from, state);
 681         for (;;) {
 682                 if (!to_state && !state)
 683                         break;
 684                 if (cmp_tracker(to_state, state) < 0) {
 685                         smatch_msg("error:  Internal smatch error.");
 686                         NEXT_PTR_LIST(to_state);
 687                 } else if (cmp_tracker(to_state, state) == 0) {
 688                         if (to_state != state) {
 689                                 if (to_state->my_pools)
 690                                         smatch_msg("to_state '%s' has pools", to_state->name);
 691                                 if (state->my_pools)
 692                                         smatch_msg("state '%s' has pools", state->name);
 693                                 add_pool(&to_state->my_pools, implied_to);
 694                                 add_pool(&state->my_pools, implied_from);
 695                         }
 696
 697                         tmp = merge_sm_states(to_state, state);
 698                         add_ptr_list(&results, tmp);
 699                         NEXT_PTR_LIST(to_state);
 700                         NEXT_PTR_LIST(state);
 701                 } else {
 702                         smatch_msg("error:  Internal smatch error.");
 703                         NEXT_PTR_LIST(state);
 704                 }
 705         }
 706         FINISH_PTR_LIST(state);
 707         FINISH_PTR_LIST(to_state);
 708
 709         free_slist(to);
 710         *to = results;
 711 }
 712
 713 void merge_slist(struct state_list **to, struct state_list *slist)
 714 {
 715         __merge_slist(to, slist, 0);
 716 }
 717
 718 void merge_slist_clone(struct state_list **to, struct state_list *slist)
 719 {
 720         __merge_slist(to, slist, 1);
 721 }
 722
 723 /*
 724  * and_slist_stack() is basically the same as popping the top two slists,
 725  * overwriting the one with the other and pushing it back on the stack.
 726  * The difference is that it checks to see that a mutually exclusive
 727  * state isn't included in both stacks.  If smatch sees something like
 728  * "if (a && !a)" it prints a warning.
 729  */
 730 void and_slist_stack(struct state_list_stack **slist_stack)
 731 {
 732         struct sm_state *tmp;
 733         struct state_list *right_slist = pop_slist(slist_stack);
 734
 735         FOR_EACH_PTR(right_slist, tmp) {
 736                 overwrite_sm_state_stack(slist_stack, tmp);
 737         } END_FOR_EACH_PTR(tmp);
 738         free_slist(&right_slist);
 739 }
 740
 741 /*
 742  * or_slist_stack() is for if we have:  if (foo || bar) { foo->baz;
 743  * It pops the two slists from the top of the stack and merges them
 744  * together in a way that preserves the things they have in common
 745  * but creates a merged state for most of the rest.
 746  * You could have code that had:  if (foo || foo) { foo->baz;
 747  * It's this function which ensures smatch does the right thing.
 748  */
 749 void or_slist_stack(struct state_list_stack **pre_conds,
 750                     struct state_list *cur_slist,
 751                     struct state_list_stack **slist_stack)
 752 {
 753         struct state_list *new;
 754         struct state_list *old;
 755         struct state_list *res = NULL;
 756         struct state_list *tmp_slist;
 757
 758         new = pop_slist(slist_stack);
 759         old = pop_slist(slist_stack);
 760
 761         tmp_slist = pop_slist(pre_conds);
 762         res = clone_slist(tmp_slist);
 763         push_slist(pre_conds, tmp_slist);
 764         overwrite_slist(old, &res);
 765
 766         tmp_slist = clone_slist(cur_slist);
 767         overwrite_slist(new, &tmp_slist);
 768
 769         merge_slist(&res, tmp_slist);
 770
 771         push_slist(slist_stack, res);
 772         free_slist(&tmp_slist);
 773         free_slist(&new);
 774         free_slist(&old);
 775 }
 776
 777 /*
 778  * get_slist_from_named_stack() is only used for gotos.
 779  */
 780 struct state_list **get_slist_from_named_stack(struct named_stack *stack,
 781                                               const char *name)
 782 {
 783         struct named_slist *tmp;
 784
 785         FOR_EACH_PTR(stack, tmp) {
 786                 if (!strcmp(tmp->name, name))
 787                         return &tmp->slist;
 788         } END_FOR_EACH_PTR(tmp);
 789         return NULL;
 790 }
 791
 792 void overwrite_slist(struct state_list *from, struct state_list **to)
 793 {
 794         struct sm_state *tmp;
 795
 796         FOR_EACH_PTR(from, tmp) {
 797                 overwrite_sm_state(to, tmp);
 798         } END_FOR_EACH_PTR(tmp);
 799 }