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 #undef CHECKMYPOOLS
  17
  18 ALLOCATOR(sm_state, "smatch state");
  19 ALLOCATOR(named_slist, "named slist");
  20
  21 void __print_slist(struct state_list *slist)
  22 {
  23         struct sm_state *state;
  24         struct sm_state *poss;
  25         int i;
  26
  27         printf("dumping slist at %d\n", get_lineno());
  28         FOR_EACH_PTR(slist, state) {
  29                 printf("%d '%s'=%s (", state->owner, state->name,
  30                         show_state(state->state));
  31                 i = 0;
  32                 FOR_EACH_PTR(state->possible, poss) {
  33                         if (i++)
  34                                 printf(", ");
  35                         printf("%s", show_state(poss->state));
  36                 } END_FOR_EACH_PTR(poss);
  37                 printf(")\n");
  38         } END_FOR_EACH_PTR(state);
  39         printf("---\n");
  40 }
  41
  42
  43 /* NULL states go at the end to simplify merge_slist */
  44 int cmp_tracker(const struct sm_state *a, const struct sm_state *b)
  45 {
  46         int ret;
  47
  48         if (!a && !b)
  49                 return 0;
  50         if (!b)
  51                 return -1;
  52         if (!a)
  53                 return 1;
  54
  55         if (a->owner > b->owner)
  56                 return -1;
  57         if (a->owner < b->owner)
  58                 return 1;
  59
  60         ret = strcmp(a->name, b->name);
  61         if (ret)
  62                 return ret;
  63
  64         if (!b->sym && a->sym)
  65                 return -1;
  66         if (!a->sym && b->sym)
  67                 return 1;
  68         if (a->sym > b->sym)
  69                 return -1;
  70         if (a->sym < b->sym)
  71                 return 1;
  72
  73         return 0;
  74 }
  75
  76 static int cmp_sm_states(const struct sm_state *a, const struct sm_state *b)
  77 {
  78         int ret;
  79
  80         ret = cmp_tracker(a, b);
  81         if (ret)
  82                 return ret;
  83
  84         /* todo:  add hook for smatch_extra.c */
  85         if (a->state > b->state)
  86                 return -1;
  87         if (a->state < b->state)
  88                 return 1;
  89         return 0;
  90 }
  91
  92 void add_sm_state_slist(struct state_list **slist, struct sm_state *new)
  93 {
  94         struct sm_state *tmp;
  95
  96         FOR_EACH_PTR(*slist, tmp) {
  97                 if (cmp_sm_states(tmp, new) < 0)
  98                         continue;
  99                 else if (cmp_sm_states(tmp, new) == 0) {
 100                         return;
 101                 } else {
 102                         INSERT_CURRENT(new, tmp);
 103                         return;
 104                 }
 105         } END_FOR_EACH_PTR(tmp);
 106         add_ptr_list(slist, new);
 107 }
 108
 109 static void add_possible(struct sm_state *sm, struct sm_state *new)
 110 {
 111         struct sm_state *tmp;
 112         struct sm_state *tmp2;
 113
 114         if (!new) {
 115                 struct smatch_state *s;
 116
 117                 s = merge_states(sm->name, sm->owner, sm->sym, sm->state, NULL);
 118                 tmp = alloc_state(sm->name, sm->owner, sm->sym, s);
 119                 add_sm_state_slist(&sm->possible, tmp);
 120                 return;
 121         }
 122
 123         FOR_EACH_PTR(new->possible, tmp) {
 124                 tmp2 = alloc_state(tmp->name, tmp->owner, tmp->sym, tmp->state);
 125                 add_sm_state_slist(&sm->possible, tmp2);
 126         } END_FOR_EACH_PTR(tmp);
 127 }
 128
 129 struct sm_state *alloc_state(const char *name, int owner,
 130                              struct symbol *sym, struct smatch_state *state)
 131 {
 132         struct sm_state *sm_state = __alloc_sm_state(0);
 133
 134         sm_state->name = alloc_string(name);
 135         sm_state->owner = owner;
 136         sm_state->sym = sym;
 137         sm_state->state = state;
 138         sm_state->line = get_lineno();
 139         sm_state->my_pools = NULL;
 140         sm_state->all_pools = NULL;
 141         sm_state->possible = NULL;
 142         add_ptr_list(&sm_state->possible, sm_state);
 143         return sm_state;
 144 }
 145
 146 static void free_sm_state(struct sm_state *sm)
 147 {
 148                 free_string(sm->name);
 149                 free_slist(&sm->possible);
 150                 free_stack(&sm->my_pools);
 151                 free_stack(&sm->all_pools);
 152                 /*
 153                  * fixme.  Free the actual state.
 154                  * Right now we leave it until the end of the function
 155                  * because we don't want to double free it.
 156                  * Use the freelist to not double free things
 157                  */
 158 }
 159
 160 static void free_all_sm_states(struct allocation_blob *blob)
 161 {
 162         unsigned int size = sizeof(struct sm_state);
 163         unsigned int offset = 0;
 164
 165         while (offset < blob->offset) {
 166                 free_sm_state((struct sm_state *)(blob->data + offset));
 167                 offset += size;
 168         }
 169 }
 170
 171 /* At the end of every function we free all the sm_states */
 172 void free_every_single_sm_state(void)
 173 {
 174         struct allocator_struct *desc = &sm_state_allocator;
 175         struct allocation_blob *blob = desc->blobs;
 176
 177         desc->blobs = NULL;
 178         desc->allocations = 0;
 179         desc->total_bytes = 0;
 180         desc->useful_bytes = 0;
 181         desc->freelist = NULL;
 182         while (blob) {
 183                 struct allocation_blob *next = blob->next;
 184                 free_all_sm_states(blob);
 185                 blob_free(blob, desc->chunking);
 186                 blob = next;
 187         }
 188 }
 189
 190 struct sm_state *clone_state(struct sm_state *s)
 191 {
 192         struct sm_state *ret;
 193         struct sm_state *poss;
 194
 195         ret = alloc_state(s->name, s->owner, s->sym, s->state);
 196         ret->line = s->line;
 197         ret->my_pools = clone_stack(s->my_pools);
 198         ret->all_pools = clone_stack(s->all_pools);
 199         FOR_EACH_PTR(s->possible, poss) {
 200                 add_sm_state_slist(&ret->possible, poss);
 201         } END_FOR_EACH_PTR(poss);
 202         return ret;
 203 }
 204
 205 int slist_has_state(struct state_list *slist, struct smatch_state *state)
 206 {
 207         struct sm_state *tmp;
 208
 209         FOR_EACH_PTR(slist, tmp) {
 210                 if (tmp->state == state)
 211                         return 1;
 212         } END_FOR_EACH_PTR(tmp);
 213         return 0;
 214 }
 215
 216 static void check_order(struct state_list *slist)
 217 {
 218 #ifdef CHECKORDER
 219         struct sm_state *state;
 220         struct sm_state *last = NULL;
 221         int printed = 0;
 222
 223         FOR_EACH_PTR(slist, state) {
 224                 if (last && cmp_tracker(state, last) <= 0) {
 225                         printf("Error.  Unsorted slist %d vs %d, %p vs %p, "
 226                                "%s vs %s\n", last->owner, state->owner,
 227                                last->sym, state->sym, last->name, state->name);
 228                         printed = 1;
 229                 }
 230                 last = state;
 231         } END_FOR_EACH_PTR(state);
 232
 233         if (printed)
 234                 printf("======\n");
 235 #endif
 236 }
 237 #ifdef CHECKMYPOOLS
 238 static void check_my_pools(struct sm_state *sm)
 239 {
 240        struct sm_state *poss;
 241        struct state_list *slist;
 242
 243        if (sm->state != &merged)
 244                return;
 245
 246        FOR_EACH_PTR(sm->possible, poss) {
 247                if (poss->state == &merged)
 248                        continue;
 249                FOR_EACH_PTR(sm->my_pools, slist) {
 250                        if (get_state_slist(slist, sm->name, sm->owner, sm->sym)
 251                            == poss->state)
 252                                goto found;
 253                } END_FOR_EACH_PTR(slist);
 254                printf("%d pool not found for '%s' possible state \"%s\".\n",
 255                       get_lineno(), sm->name, show_state(poss->state));
 256                return;
 257 found:
 258                continue;
 259        } END_FOR_EACH_PTR(poss);
 260 }
 261 #endif
 262
 263 static void sanity_check_pools(struct state_list *slist)
 264 {
 265 #ifdef CHECKMYPOOLS
 266        struct sm_state *tmp;
 267
 268        FOR_EACH_PTR(slist, tmp) {
 269                check_my_pools(tmp);
 270        } END_FOR_EACH_PTR(tmp);
 271 #endif
 272 }
 273
 274 struct state_list *clone_slist(struct state_list *from_slist)
 275 {
 276         struct sm_state *state;
 277         struct sm_state *tmp;
 278         struct state_list *to_slist = NULL;
 279
 280         FOR_EACH_PTR(from_slist, state) {
 281                 tmp = clone_state(state);
 282                 add_ptr_list(&to_slist, tmp);
 283         } END_FOR_EACH_PTR(state);
 284         check_order(to_slist);
 285         return to_slist;
 286 }
 287
 288 struct state_list_stack *clone_stack(struct state_list_stack *from_stack)
 289 {
 290         struct state_list *slist;
 291         struct state_list_stack *to_stack = NULL;
 292
 293         FOR_EACH_PTR(from_stack, slist) {
 294                 push_slist(&to_stack, slist);
 295         } END_FOR_EACH_PTR(slist);
 296         return to_stack;
 297 }
 298
 299 struct smatch_state *merge_states(const char *name, int owner,
 300                                   struct symbol *sym,
 301                                   struct smatch_state *state1,
 302                                   struct smatch_state *state2)
 303 {
 304         struct smatch_state *ret;
 305
 306         if (state1 == state2)
 307                 ret = state1;
 308         else if (__has_merge_function(owner))
 309                 ret = __client_merge_function(owner, name, sym, state1, state2);
 310         else if (!state1 || !state2)
 311                 ret = &undefined;
 312         else
 313                 ret = &merged;
 314         return ret;
 315 }
 316
 317 /*
 318  * add_pool() adds a slist to ->pools. If the slist has already been
 319  * added earlier then it doesn't get added a second time.
 320  */
 321 static void add_pool(struct state_list_stack **pools, struct state_list *new)
 322 {
 323         struct state_list *tmp;
 324
 325         FOR_EACH_PTR(*pools, tmp) {
 326                 if (tmp < new)
 327                         continue;
 328                 else if (tmp == new) {
 329                         return;
 330                 } else {
 331                         INSERT_CURRENT(new, tmp);
 332                         return;
 333                 }
 334         } END_FOR_EACH_PTR(tmp);
 335         add_ptr_list(pools, new);
 336 }
 337
 338 static void copy_pools(struct sm_state *to, struct sm_state *sm)
 339 {
 340         struct state_list *tmp;
 341
 342         if (!sm)
 343                 return;
 344
 345         FOR_EACH_PTR(sm->my_pools, tmp) {
 346                 add_pool(&to->my_pools, tmp);
 347         } END_FOR_EACH_PTR(tmp);
 348
 349         FOR_EACH_PTR(sm->all_pools, tmp) {
 350                 add_pool(&to->all_pools, tmp);
 351         } END_FOR_EACH_PTR(tmp);
 352 }
 353
 354 struct sm_state *merge_sm_states(struct sm_state *one, struct sm_state *two)
 355 {
 356         struct smatch_state *s;
 357         struct sm_state *result;
 358
 359         s = merge_states(one->name, one->owner, one->sym, one->state,
 360                         (two?two->state:NULL));
 361         result = alloc_state(one->name, one->owner, one->sym, s);
 362         if (two && one->line == two->line)
 363                 result->line = one->line;
 364         add_possible(result, one);
 365         add_possible(result, two);
 366         copy_pools(result, one);
 367         copy_pools(result, two);
 368
 369         if (debug_states) {
 370                 struct sm_state *tmp;
 371                 int i = 0;
 372
 373                 printf("%d merge name='%s' owner=%d: %s + %s => %s (",
 374                         get_lineno(), one->name, one->owner,
 375                         show_state(one->state), show_state(two?two->state:NULL),
 376                         show_state(s));
 377
 378                 FOR_EACH_PTR(result->possible, tmp) {
 379                         if (i++) {
 380                                 printf(", ");
 381                         }
 382                         printf("%s", show_state(tmp->state));
 383                 } END_FOR_EACH_PTR(tmp);
 384                 printf(")\n");
 385         }
 386
 387         return result;
 388 }
 389
 390 struct sm_state *get_sm_state_slist(struct state_list *slist, const char *name,
 391                                 int owner, struct symbol *sym)
 392 {
 393         struct sm_state *state;
 394
 395         if (!name)
 396                 return NULL;
 397
 398         FOR_EACH_PTR(slist, state) {
 399                 if (state->owner == owner && state->sym == sym
 400                     && !strcmp(state->name, name))
 401                         return state;
 402         } END_FOR_EACH_PTR(state);
 403         return NULL;
 404 }
 405
 406 struct smatch_state *get_state_slist(struct state_list *slist,
 407                                 const char *name, int owner,
 408                                 struct symbol *sym)
 409 {
 410         struct sm_state *state;
 411
 412         state = get_sm_state_slist(slist, name, owner, sym);
 413         if (state)
 414                 return state->state;
 415         return NULL;
 416 }
 417
 418 void overwrite_sm_state(struct state_list **slist, struct sm_state *new)
 419 {
 420         struct sm_state *tmp;
 421
 422         FOR_EACH_PTR(*slist, tmp) {
 423                 if (cmp_tracker(tmp, new) < 0)
 424                         continue;
 425                 else if (cmp_tracker(tmp, new) == 0) {
 426                         REPLACE_CURRENT_PTR(tmp, new);
 427                         return;
 428                 } else {
 429                         INSERT_CURRENT(new, tmp);
 430                         return;
 431                 }
 432         } END_FOR_EACH_PTR(tmp);
 433         add_ptr_list(slist, new);
 434 }
 435
 436 void overwrite_sm_state_stack(struct state_list_stack **stack,
 437                         struct sm_state *state)
 438 {
 439         struct state_list *slist;
 440
 441         slist = pop_slist(stack);
 442         overwrite_sm_state(&slist, state);
 443         push_slist(stack, slist);
 444 }
 445
 446 void set_state_slist(struct state_list **slist, const char *name, int owner,
 447                      struct symbol *sym, struct smatch_state *state)
 448 {
 449         struct sm_state *tmp;
 450         struct sm_state *new = alloc_state(name, owner, sym, state);
 451
 452         FOR_EACH_PTR(*slist, tmp) {
 453                 if (cmp_tracker(tmp, new) < 0)
 454                         continue;
 455                 else if (cmp_tracker(tmp, new) == 0) {
 456                         REPLACE_CURRENT_PTR(tmp, new);
 457                         return;
 458                 } else {
 459                         INSERT_CURRENT(new, tmp);
 460                         return;
 461                 }
 462         } END_FOR_EACH_PTR(tmp);
 463         add_ptr_list(slist, new);
 464 }
 465
 466 void delete_state_slist(struct state_list **slist, const char *name, int owner,
 467                         struct symbol *sym)
 468 {
 469         struct sm_state *state;
 470
 471         FOR_EACH_PTR(*slist, state) {
 472                 if (state->owner == owner && state->sym == sym
 473                     && !strcmp(state->name, name)){
 474                         delete_ptr_list_entry((struct ptr_list **)slist,
 475                                               state, 1);
 476                         return;
 477                 }
 478         } END_FOR_EACH_PTR(state);
 479 }
 480
 481
 482 void push_slist(struct state_list_stack **list_stack, struct state_list *slist)
 483 {
 484         add_ptr_list(list_stack, slist);
 485 }
 486
 487 struct state_list *pop_slist(struct state_list_stack **list_stack)
 488 {
 489         struct state_list *slist;
 490
 491         slist = last_ptr_list((struct ptr_list *)*list_stack);
 492         delete_ptr_list_last((struct ptr_list **)list_stack);
 493         return slist;
 494 }
 495
 496 void free_slist(struct state_list **slist)
 497 {
 498         __free_ptr_list((struct ptr_list **)slist);
 499 }
 500
 501 void free_stack(struct state_list_stack **stack)
 502 {
 503         __free_ptr_list((struct ptr_list **)stack);
 504 }
 505
 506 void free_stack_and_slists(struct state_list_stack **slist_stack)
 507 {
 508         struct state_list *slist;
 509
 510         FOR_EACH_PTR(*slist_stack, slist) {
 511                 free_slist(&slist);
 512         } END_FOR_EACH_PTR(slist);
 513         free_stack(slist_stack);
 514 }
 515
 516 /*
 517  * set_state_stack() sets the state for the top slist on the stack.
 518  */
 519 void set_state_stack(struct state_list_stack **stack, const char *name,
 520                      int owner, struct symbol *sym, struct smatch_state *state)
 521 {
 522         struct state_list *slist;
 523
 524         slist = pop_slist(stack);
 525         set_state_slist(&slist, name, owner, sym, state);
 526         push_slist(stack, slist);
 527 }
 528
 529 /*
 530  * get_sm_state_stack() gets the state for the top slist on the stack.
 531  */
 532 struct sm_state *get_sm_state_stack(struct state_list_stack *stack,
 533                                     const char *name, int owner,
 534                                     struct symbol *sym)
 535 {
 536         struct state_list *slist;
 537         struct sm_state *ret;
 538
 539         slist = pop_slist(&stack);
 540         ret = get_sm_state_slist(slist, name, owner, sym);
 541         push_slist(&stack, slist);
 542         return ret;
 543 }
 544
 545
 546 struct smatch_state *get_state_stack(struct state_list_stack *stack,
 547                                      const char *name, int owner,
 548                                      struct symbol *sym)
 549 {
 550         struct sm_state *state;
 551
 552         state = get_sm_state_stack(stack, name, owner, sym);
 553         if (state)
 554                 return state->state;
 555         return NULL;
 556 }
 557
 558 static void register_implied_pool(struct state_list *pool)
 559 {
 560         struct sm_state *sm;
 561
 562         FOR_EACH_PTR(pool, sm) {
 563                 if (sm->state != &merged)
 564                         free_stack(&sm->my_pools);
 565                 if (!sm->my_pools)
 566                         add_pool(&sm->my_pools, pool);
 567                 add_pool(&sm->all_pools, pool);
 568         } END_FOR_EACH_PTR(sm);
 569
 570         push_slist(&implied_pools, pool);
 571 }
 572
 573 static void match_states(struct state_list **one, struct state_list **two)
 574 {
 575         struct sm_state *one_state;
 576         struct sm_state *two_state;
 577         struct sm_state *tmp;
 578         struct smatch_state *tmp_state;
 579         struct state_list *add_to_one = NULL;
 580         struct state_list *add_to_two = NULL;
 581
 582         PREPARE_PTR_LIST(*one, one_state);
 583         PREPARE_PTR_LIST(*two, two_state);
 584         for (;;) {
 585                 if (!one_state && !two_state)
 586                         break;
 587                 if (cmp_tracker(one_state, two_state) < 0) {
 588                         tmp_state = __client_unmatched_state_function(one_state);
 589                         tmp = alloc_state(one_state->name, one_state->owner,
 590                                           one_state->sym, tmp_state);
 591                         add_ptr_list(&add_to_two, tmp);
 592                         NEXT_PTR_LIST(one_state);
 593                 } else if (cmp_tracker(one_state, two_state) == 0) {
 594                         NEXT_PTR_LIST(one_state);
 595                         NEXT_PTR_LIST(two_state);
 596                 } else {
 597                         tmp_state = __client_unmatched_state_function(two_state);
 598                         tmp = alloc_state(two_state->name, two_state->owner,
 599                                           two_state->sym, tmp_state);
 600                         add_ptr_list(&add_to_one, tmp);
 601                         NEXT_PTR_LIST(two_state);
 602                 }
 603         }
 604         FINISH_PTR_LIST(two_state);
 605         FINISH_PTR_LIST(one_state);
 606
 607         overwrite_slist(add_to_one, one);
 608         overwrite_slist(add_to_two, two);
 609 }
 610
 611 /*
 612  * merge_slist() is called whenever paths merge, such as after
 613  * an if statement.  It takes the two slists and creates one.
 614  */
 615 void merge_slist(struct state_list **to, struct state_list *slist)
 616 {
 617         struct sm_state *to_state, *state, *tmp;
 618         struct state_list *results = NULL;
 619         struct state_list *implied_to = NULL;
 620         struct state_list *implied_from = NULL;
 621
 622         check_order(*to);
 623         check_order(slist);
 624         sanity_check_pools(*to);
 625         sanity_check_pools(slist);
 626
 627         /* merging a null and nonnull path gives you only the nonnull path */
 628         if (!slist) {
 629                 return;
 630         }
 631         if (!*to) {
 632                 *to = clone_slist(slist);
 633                 return;
 634         }
 635
 636         implied_to = clone_slist(*to);
 637         implied_from = clone_slist(slist);
 638
 639         match_states(&implied_to, &implied_from);
 640
 641         register_implied_pool(implied_to);
 642         register_implied_pool(implied_from);
 643
 644         PREPARE_PTR_LIST(implied_to, to_state);
 645         PREPARE_PTR_LIST(implied_from, state);
 646         for (;;) {
 647                 if (!to_state && !state)
 648                         break;
 649                 if (cmp_tracker(to_state, state) < 0) {
 650                         smatch_msg("error:  Internal smatch error.");
 651                         NEXT_PTR_LIST(to_state);
 652                 } else if (cmp_tracker(to_state, state) == 0) {
 653                         tmp = merge_sm_states(to_state, state);
 654                         add_ptr_list(&results, tmp);
 655                         NEXT_PTR_LIST(to_state);
 656                         NEXT_PTR_LIST(state);
 657                 } else {
 658                         smatch_msg("error:  Internal smatch error.");
 659                         NEXT_PTR_LIST(state);
 660                 }
 661         }
 662         FINISH_PTR_LIST(state);
 663         FINISH_PTR_LIST(to_state);
 664
 665         free_slist(to);
 666         *to = results;
 667 }
 668
 669 static struct sm_state *find_intersection(struct sm_state *one,
 670                                           struct sm_state *two)
 671 {
 672         struct state_list *tmp1, *tmp2;
 673         struct state_list_stack *stack = NULL;
 674         struct sm_state *tmp_state;
 675         struct sm_state *ret;
 676
 677         if (!one)
 678                 return two;
 679         if (one->state != &merged) {
 680                 if (one->state == two->state)
 681                         return one;
 682                 if (two->state != &merged) {
 683                         smatch_msg("mutually exclusive 'and' conditions states "
 684                                    "'%s': %s + %s", one->name,
 685                                    show_state(one->state),
 686                                    show_state(two->state));
 687                         return two;
 688                 }
 689         }
 690
 691         PREPARE_PTR_LIST(one->my_pools, tmp1);
 692         PREPARE_PTR_LIST(two->my_pools, tmp2);
 693         for (;;) {
 694                 if (!tmp1 && !tmp2)
 695                         break;
 696                 if (!tmp2 || (tmp1 && tmp1 < tmp2)) {
 697                         NEXT_PTR_LIST(tmp1);
 698                 } else if (tmp1 == tmp2) {
 699                         push_slist(&stack, tmp1);
 700                         NEXT_PTR_LIST(tmp1);
 701                         NEXT_PTR_LIST(tmp2);
 702                 } else {
 703                         NEXT_PTR_LIST(tmp2);
 704                 }
 705         }
 706         FINISH_PTR_LIST(tmp2);
 707         FINISH_PTR_LIST(tmp1);
 708
 709         if (!stack) {
 710                 smatch_msg("mutually eXclusive 'and' conditions states "
 711                            "'%s': %s + %s", one->name, show_state(one->state),
 712                            show_state(two->state));
 713                 return two;
 714         }
 715
 716         ret = alloc_state(one->name, one->owner, one->sym, &merged);
 717         FOR_EACH_PTR(stack, tmp1) {
 718                 tmp_state = get_sm_state_slist(tmp1, one->name, one->owner,
 719                                                one->sym);
 720                 add_possible(ret, tmp_state);
 721         } END_FOR_EACH_PTR(tmp1);
 722         ret->my_pools = stack;
 723         ret->all_pools = clone_stack(stack);
 724         return ret;
 725 }
 726
 727 /*
 728  * and_slist_stack() is basically the same as popping the top two slists,
 729  * overwriting the one with the other and pushing it back on the stack.
 730  * The difference is that it checks to see that a mutually exclusive
 731  * state isn't included in both stacks.  If smatch sees something like
 732  * "if (a && !a)" it prints a warning.
 733  */
 734 void and_slist_stack(struct state_list_stack **slist_stack)
 735 {
 736         struct sm_state *tmp;
 737         struct sm_state *left_state;
 738         struct sm_state *res;
 739         struct state_list *right_slist = pop_slist(slist_stack);
 740
 741         FOR_EACH_PTR(right_slist, tmp) {
 742                 left_state = get_sm_state_stack(*slist_stack, tmp->name,
 743                                                 tmp->owner, tmp->sym);
 744                 res = find_intersection(left_state, tmp);
 745                 overwrite_sm_state_stack(slist_stack, res);
 746         } END_FOR_EACH_PTR(tmp);
 747         free_slist(&right_slist);
 748 }
 749
 750 /*
 751  * or_slist_stack() is for if we have:  if (foo || bar) { foo->baz;
 752  * It pops the two slists from the top of the stack and merges them
 753  * together in a way that preserves the things they have in common
 754  * but creates a merged state for most of the rest.
 755  * You could have code that had:  if (foo || foo) { foo->baz;
 756  * It's this function which ensures smatch does the right thing.
 757  */
 758 void or_slist_stack(struct state_list_stack **pre_conds,
 759                     struct state_list *cur_slist,
 760                     struct state_list_stack **slist_stack)
 761 {
 762         struct state_list *new;
 763         struct state_list *old;
 764         struct state_list *res = NULL;
 765         struct state_list *tmp_slist;
 766
 767         new = pop_slist(slist_stack);
 768         old = pop_slist(slist_stack);
 769
 770         tmp_slist = pop_slist(pre_conds);
 771         res = clone_slist(tmp_slist);
 772         push_slist(pre_conds, tmp_slist);
 773         overwrite_slist(old, &res);
 774
 775         tmp_slist = clone_slist(cur_slist);
 776         overwrite_slist(new, &tmp_slist);
 777
 778         merge_slist(&res, tmp_slist);
 779
 780         push_slist(slist_stack, res);
 781         free_slist(&tmp_slist);
 782         free_slist(&new);
 783         free_slist(&old);
 784 }
 785
 786 /*
 787  * get_slist_from_named_stack() is only used for gotos.
 788  */
 789 struct state_list **get_slist_from_named_stack(struct named_stack *stack,
 790                                               const char *name)
 791 {
 792         struct named_slist *tmp;
 793
 794         FOR_EACH_PTR(stack, tmp) {
 795                 if (!strcmp(tmp->name, name))
 796                         return &tmp->slist;
 797         } END_FOR_EACH_PTR(tmp);
 798         return NULL;
 799 }
 800
 801 void overwrite_slist(struct state_list *from, struct state_list **to)
 802 {
 803         struct sm_state *tmp;
 804
 805         FOR_EACH_PTR(from, tmp) {
 806                 overwrite_sm_state(to, tmp);
 807         } END_FOR_EACH_PTR(tmp);
 808 }
 809
 810 unsigned int __get_allocations()
 811 {
 812         return sm_state_allocator.allocations;
 813 }