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, 1, 4, "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
 172         FOR_EACH_PTR(from->possible, tmp) {
 173                 add_sm_state_slist(&to->possible, tmp);
 174         } END_FOR_EACH_PTR(tmp);
 175 }
 176
 177 char *alloc_sname(const char *str)
 178 {
 179         char *tmp;
 180
 181         if (!str)
 182                 return NULL;
 183         tmp = __alloc_sname(strlen(str) + 1);
 184         strcpy(tmp, str);
 185         return tmp;
 186 }
 187
 188 int out_of_memory()
 189 {
 190         /*
 191          * I decided to use 50M here based on trial and error.
 192          * It works out OK for the kernel and so it should work
 193          * for most other projects as well.
 194          */
 195         if (sm_state_counter * sizeof(struct sm_state) >= 50000000)
 196                 return 1;
 197         return 0;
 198 }
 199
 200 int low_on_memory(void)
 201 {
 202         if (sm_state_counter * sizeof(struct sm_state) >= 25000000)
 203                 return 1;
 204         return 0;
 205 }
 206
 207 static void free_sm_state(struct sm_state *sm)
 208 {
 209         free_slist(&sm->possible);
 210         /*
 211          * fixme.  Free the actual state.
 212          * Right now we leave it until the end of the function
 213          * because we don't want to double free it.
 214          * Use the freelist to not double free things
 215          */
 216 }
 217
 218 static void free_all_sm_states(struct allocation_blob *blob)
 219 {
 220         unsigned int size = sizeof(struct sm_state);
 221         unsigned int offset = 0;
 222
 223         while (offset < blob->offset) {
 224                 free_sm_state((struct sm_state *)(blob->data + offset));
 225                 offset += size;
 226         }
 227 }
 228
 229 /* At the end of every function we free all the sm_states */
 230 void free_every_single_sm_state(void)
 231 {
 232         struct allocator_struct *desc = &sm_state_allocator;
 233         struct allocation_blob *blob = desc->blobs;
 234
 235         desc->blobs = NULL;
 236         desc->allocations = 0;
 237         desc->total_bytes = 0;
 238         desc->useful_bytes = 0;
 239         desc->freelist = NULL;
 240         while (blob) {
 241                 struct allocation_blob *next = blob->next;
 242                 free_all_sm_states(blob);
 243                 blob_free(blob, desc->chunking);
 244                 blob = next;
 245         }
 246         clear_sname_alloc();
 247         clear_smatch_state_alloc();
 248
 249         sm_state_counter = 0;
 250 }
 251
 252 struct sm_state *clone_sm(struct sm_state *s)
 253 {
 254         struct sm_state *ret;
 255
 256         ret = alloc_state_no_name(s->owner, s->name, s->sym, s->state);
 257         ret->merged = s->merged;
 258         ret->implied = s->implied;
 259         ret->line = s->line;
 260         /* clone_sm() doesn't copy the pools.  Each state needs to have
 261            only one pool. */
 262         ret->possible = clone_slist(s->possible);
 263         ret->left = s->left;
 264         ret->right = s->right;
 265         ret->nr_children = s->nr_children;
 266         return ret;
 267 }
 268
 269 int is_merged(struct sm_state *sm)
 270 {
 271         return sm->merged;
 272 }
 273
 274 int is_implied(struct sm_state *sm)
 275 {
 276         return sm->implied;
 277 }
 278
 279 int slist_has_state(struct state_list *slist, struct smatch_state *state)
 280 {
 281         struct sm_state *tmp;
 282
 283         FOR_EACH_PTR(slist, tmp) {
 284                 if (tmp->state == state)
 285                         return 1;
 286         } END_FOR_EACH_PTR(tmp);
 287         return 0;
 288 }
 289
 290 static void check_order(struct state_list *slist)
 291 {
 292 #ifdef CHECKORDER
 293         struct sm_state *sm;
 294         struct sm_state *last = NULL;
 295         int printed = 0;
 296
 297         FOR_EACH_PTR(slist, sm) {
 298                 if (last && cmp_tracker(sm, last) <= 0) {
 299                         printf("Error.  Unsorted slist %d vs %d, %p vs %p, "
 300                                "%s vs %s\n", last->owner, sm->owner,
 301                                last->sym, sm->sym, last->name, sm->name);
 302                         printed = 1;
 303                 }
 304                 last = sm;
 305         } END_FOR_EACH_PTR(sm);
 306
 307         if (printed)
 308                 printf("======\n");
 309 #endif
 310 }
 311
 312 struct state_list *clone_slist(struct state_list *from_slist)
 313 {
 314         struct sm_state *sm;
 315         struct state_list *to_slist = NULL;
 316
 317         FOR_EACH_PTR(from_slist, sm) {
 318                 add_ptr_list(&to_slist, sm);
 319         } END_FOR_EACH_PTR(sm);
 320         return to_slist;
 321 }
 322
 323 struct state_list_stack *clone_stack(struct state_list_stack *from_stack)
 324 {
 325         struct state_list *slist;
 326         struct state_list_stack *to_stack = NULL;
 327
 328         FOR_EACH_PTR(from_stack, slist) {
 329                 push_slist(&to_stack, slist);
 330         } END_FOR_EACH_PTR(slist);
 331         return to_stack;
 332 }
 333
 334 struct smatch_state *merge_states(int owner, const char *name,
 335                                   struct symbol *sym,
 336                                   struct smatch_state *state1,
 337                                   struct smatch_state *state2)
 338 {
 339         struct smatch_state *ret;
 340
 341         if (state1 == state2)
 342                 ret = state1;
 343         else if (__has_merge_function(owner))
 344                 ret = __client_merge_function(owner, state1, state2);
 345         else if (!state1 || !state2)
 346                 ret = &undefined;
 347         else
 348                 ret = &merged;
 349         return ret;
 350 }
 351
 352 struct sm_state *merge_sm_states(struct sm_state *one, struct sm_state *two)
 353 {
 354         struct smatch_state *s;
 355         struct sm_state *result;
 356
 357         if (one == two)
 358                 return one;
 359         s = merge_states(one->owner, one->name, one->sym, one->state, two->state);
 360         result = alloc_state_no_name(one->owner, one->name, one->sym, s);
 361         result->merged = 1;
 362         result->left = one;
 363         result->right = two;
 364         result->nr_children = one->nr_children + two->nr_children;
 365         copy_possibles(result, one);
 366         copy_possibles(result, two);
 367
 368         if (option_debug) {
 369                 struct sm_state *tmp;
 370                 int i = 0;
 371
 372                 printf("%d merge [%s] '%s' %s(L %d) + %s(L %d) => %s (",
 373                         get_lineno(), check_name(one->owner), one->name,
 374                         show_state(one->state), one->line,
 375                         show_state(two->state), two->line,
 376                         show_state(s));
 377
 378                 FOR_EACH_PTR(result->possible, tmp) {
 379                         if (i++)
 380                                 printf(", ");
 381                         printf("%s", show_state(tmp->state));
 382                 } END_FOR_EACH_PTR(tmp);
 383                 printf(")\n");
 384         }
 385
 386         return result;
 387 }
 388
 389 struct sm_state *get_sm_state_slist(struct state_list *slist, int owner, const char *name,
 390                                 struct symbol *sym)
 391 {
 392         struct sm_state *sm;
 393
 394         if (!name)
 395                 return NULL;
 396
 397         FOR_EACH_PTR(slist, sm) {
 398                 if (sm->owner == owner && sm->sym == sym && !strcmp(sm->name, name))
 399                         return sm;
 400         } END_FOR_EACH_PTR(sm);
 401         return NULL;
 402 }
 403
 404 struct smatch_state *get_state_slist(struct state_list *slist,
 405                                 int owner, const char *name,
 406                                 struct symbol *sym)
 407 {
 408         struct sm_state *sm;
 409
 410         sm = get_sm_state_slist(slist, owner, name, sym);
 411         if (sm)
 412                 return sm->state;
 413         return NULL;
 414 }
 415
 416 void overwrite_sm_state(struct state_list **slist, struct sm_state *new)
 417 {
 418         struct sm_state *tmp;
 419
 420         FOR_EACH_PTR(*slist, tmp) {
 421                 if (cmp_tracker(tmp, new) < 0)
 422                         continue;
 423                 else if (cmp_tracker(tmp, new) == 0) {
 424                         REPLACE_CURRENT_PTR(tmp, new);
 425                         return;
 426                 } else {
 427                         INSERT_CURRENT(new, tmp);
 428                         return;
 429                 }
 430         } END_FOR_EACH_PTR(tmp);
 431         add_ptr_list(slist, new);
 432 }
 433
 434 void overwrite_sm_state_stack(struct state_list_stack **stack,
 435                         struct sm_state *sm)
 436 {
 437         struct state_list *slist;
 438
 439         slist = pop_slist(stack);
 440         overwrite_sm_state(&slist, sm);
 441         push_slist(stack, slist);
 442 }
 443
 444 struct sm_state *set_state_slist(struct state_list **slist, int owner, const char *name,
 445                      struct symbol *sym, struct smatch_state *state)
 446 {
 447         struct sm_state *tmp;
 448         struct sm_state *new = alloc_sm_state(owner, name, sym, state);
 449
 450         FOR_EACH_PTR(*slist, tmp) {
 451                 if (cmp_tracker(tmp, new) < 0)
 452                         continue;
 453                 else if (cmp_tracker(tmp, new) == 0) {
 454                         REPLACE_CURRENT_PTR(tmp, new);
 455                         return new;
 456                 } else {
 457                         INSERT_CURRENT(new, tmp);
 458                         return new;
 459                 }
 460         } END_FOR_EACH_PTR(tmp);
 461         add_ptr_list(slist, new);
 462         return new;
 463 }
 464
 465 void delete_state_slist(struct state_list **slist, int owner, const char *name,
 466                         struct symbol *sym)
 467 {
 468         struct sm_state *sm;
 469
 470         FOR_EACH_PTR(*slist, sm) {
 471                 if (sm->owner == owner && sm->sym == sym && !strcmp(sm->name, name)) {
 472                         DELETE_CURRENT_PTR(sm);
 473                         return;
 474                 }
 475         } END_FOR_EACH_PTR(sm);
 476 }
 477
 478 void delete_state_stack(struct state_list_stack **stack, int owner, const char *name,
 479                         struct symbol *sym)
 480 {
 481         struct state_list *slist;
 482
 483         slist = pop_slist(stack);
 484         delete_state_slist(&slist, owner, name, sym);
 485         push_slist(stack, slist);
 486 }
 487
 488 void push_slist(struct state_list_stack **list_stack, struct state_list *slist)
 489 {
 490         add_ptr_list(list_stack, slist);
 491 }
 492
 493 struct state_list *pop_slist(struct state_list_stack **list_stack)
 494 {
 495         struct state_list *slist;
 496
 497         slist = last_ptr_list((struct ptr_list *)*list_stack);
 498         delete_ptr_list_last((struct ptr_list **)list_stack);
 499         return slist;
 500 }
 501
 502 void free_slist(struct state_list **slist)
 503 {
 504         __free_ptr_list((struct ptr_list **)slist);
 505 }
 506
 507 void free_stack(struct state_list_stack **stack)
 508 {
 509         __free_ptr_list((struct ptr_list **)stack);
 510 }
 511
 512 void free_stack_and_slists(struct state_list_stack **slist_stack)
 513 {
 514         struct state_list *slist;
 515
 516         FOR_EACH_PTR(*slist_stack, slist) {
 517                 free_slist(&slist);
 518         } END_FOR_EACH_PTR(slist);
 519         free_stack(slist_stack);
 520 }
 521
 522 /*
 523  * set_state_stack() sets the state for the top slist on the stack.
 524  */
 525 struct sm_state *set_state_stack(struct state_list_stack **stack, int owner, const char *name,
 526                                 struct symbol *sym, struct smatch_state *state)
 527 {
 528         struct state_list *slist;
 529         struct sm_state *sm;
 530
 531         slist = pop_slist(stack);
 532         sm = set_state_slist(&slist, owner, name, sym, state);
 533         push_slist(stack, slist);
 534
 535         return sm;
 536 }
 537
 538 /*
 539  * get_sm_state_stack() gets the state for the top slist on the stack.
 540  */
 541 struct sm_state *get_sm_state_stack(struct state_list_stack *stack,
 542                                 int owner, const char *name,
 543                                 struct symbol *sym)
 544 {
 545         struct state_list *slist;
 546         struct sm_state *ret;
 547
 548         slist = pop_slist(&stack);
 549         ret = get_sm_state_slist(slist, owner, name, sym);
 550         push_slist(&stack, slist);
 551         return ret;
 552 }
 553
 554 struct smatch_state *get_state_stack(struct state_list_stack *stack,
 555                                 int owner, const char *name,
 556                                 struct symbol *sym)
 557 {
 558         struct sm_state *sm;
 559
 560         sm = get_sm_state_stack(stack, owner, name, sym);
 561         if (sm)
 562                 return sm->state;
 563         return NULL;
 564 }
 565
 566 static void match_states(struct state_list **one, struct state_list **two)
 567 {
 568         struct sm_state *one_sm;
 569         struct sm_state *two_sm;
 570         struct sm_state *tmp;
 571         struct smatch_state *tmp_state;
 572         struct state_list *add_to_one = NULL;
 573         struct state_list *add_to_two = NULL;
 574
 575         PREPARE_PTR_LIST(*one, one_sm);
 576         PREPARE_PTR_LIST(*two, two_sm);
 577         for (;;) {
 578                 if (!one_sm && !two_sm)
 579                         break;
 580                 if (cmp_tracker(one_sm, two_sm) < 0) {
 581                         __set_fake_cur_slist_fast(*two);
 582                         tmp_state = __client_unmatched_state_function(one_sm);
 583                         __pop_fake_cur_slist_fast();
 584                         tmp = alloc_state_no_name(one_sm->owner, one_sm->name,
 585                                                   one_sm->sym, tmp_state);
 586                         add_ptr_list(&add_to_two, tmp);
 587                         NEXT_PTR_LIST(one_sm);
 588                 } else if (cmp_tracker(one_sm, two_sm) == 0) {
 589                         NEXT_PTR_LIST(one_sm);
 590                         NEXT_PTR_LIST(two_sm);
 591                 } else {
 592                         __set_fake_cur_slist_fast(*one);
 593                         tmp_state = __client_unmatched_state_function(two_sm);
 594                         __pop_fake_cur_slist_fast();
 595                         tmp = alloc_state_no_name(two_sm->owner, two_sm->name,
 596                                                   two_sm->sym, tmp_state);
 597                         add_ptr_list(&add_to_one, tmp);
 598                         NEXT_PTR_LIST(two_sm);
 599                 }
 600         }
 601         FINISH_PTR_LIST(two_sm);
 602         FINISH_PTR_LIST(one_sm);
 603
 604         overwrite_slist(add_to_one, one);
 605         overwrite_slist(add_to_two, two);
 606 }
 607
 608 static void clone_pool_havers(struct state_list *slist)
 609 {
 610         struct sm_state *sm;
 611         struct sm_state *new;
 612
 613         FOR_EACH_PTR(slist, sm) {
 614                 if (sm->pool) {
 615                         new = clone_sm(sm);
 616                         REPLACE_CURRENT_PTR(sm, new);
 617                 }
 618         } END_FOR_EACH_PTR(sm);
 619 }
 620
 621 int __slist_id;
 622 /*
 623  * Sets the first state to the slist_id.
 624  */
 625 static void set_slist_id(struct state_list *slist)
 626 {
 627         struct smatch_state *state;
 628         struct sm_state *tmp, *new;
 629
 630         state = alloc_state_num(++__slist_id);
 631         new = alloc_sm_state(-1, "unnull_path", NULL, state);
 632
 633         FOR_EACH_PTR(slist, tmp) {
 634                 if (tmp->owner != (unsigned short)-1)
 635                         return;
 636                 REPLACE_CURRENT_PTR(tmp, new);
 637                 return;
 638         } END_FOR_EACH_PTR(tmp);
 639 }
 640
 641 int get_slist_id(struct state_list *slist)
 642 {
 643         struct sm_state *tmp;
 644
 645         FOR_EACH_PTR(slist, tmp) {
 646                 if (tmp->owner != (unsigned short)-1)
 647                         return 0;
 648                 return PTR_INT(tmp->state->data);
 649         } END_FOR_EACH_PTR(tmp);
 650         return 0;
 651 }
 652
 653 /*
 654  * merge_slist() is called whenever paths merge, such as after
 655  * an if statement.  It takes the two slists and creates one.
 656  */
 657 void merge_slist(struct state_list **to, struct state_list *slist)
 658 {
 659         struct sm_state *one_sm, *two_sm, *tmp;
 660         struct state_list *results = NULL;
 661         struct state_list *implied_one = NULL;
 662         struct state_list *implied_two = NULL;
 663
 664         if (out_of_memory())
 665                 return;
 666
 667         check_order(*to);
 668         check_order(slist);
 669
 670         /* merging a null and nonnull path gives you only the nonnull path */
 671         if (!slist)
 672                 return;
 673
 674         if (!*to) {
 675                 *to = clone_slist(slist);
 676                 return;
 677         }
 678
 679         implied_one = clone_slist(*to);
 680         implied_two = clone_slist(slist);
 681
 682         match_states(&implied_one, &implied_two);
 683
 684         clone_pool_havers(implied_one);
 685         clone_pool_havers(implied_two);
 686
 687         set_slist_id(implied_one);
 688         set_slist_id(implied_two);
 689
 690         PREPARE_PTR_LIST(implied_one, one_sm);
 691         PREPARE_PTR_LIST(implied_two, two_sm);
 692         for (;;) {
 693                 if (!one_sm && !two_sm)
 694                         break;
 695                 if (cmp_tracker(one_sm, two_sm) < 0) {
 696                         sm_msg("error:  Internal smatch error.");
 697                         NEXT_PTR_LIST(one_sm);
 698                 } else if (cmp_tracker(one_sm, two_sm) == 0) {
 699                         if (one_sm != two_sm) {
 700                                 one_sm->pool = implied_one;
 701                                 two_sm->pool = implied_two;
 702                         }
 703
 704                         tmp = merge_sm_states(one_sm, two_sm);
 705                         add_ptr_list(&results, tmp);
 706                         NEXT_PTR_LIST(one_sm);
 707                         NEXT_PTR_LIST(two_sm);
 708                 } else {
 709                         sm_msg("error:  Internal smatch error.");
 710                         NEXT_PTR_LIST(two_sm);
 711                 }
 712         }
 713         FINISH_PTR_LIST(two_sm);
 714         FINISH_PTR_LIST(one_sm);
 715
 716         free_slist(to);
 717         *to = results;
 718 }
 719
 720 /*
 721  * filter_slist() removes any sm states "slist" holds in common with "filter"
 722  */
 723 void filter_slist(struct state_list **slist, struct state_list *filter)
 724 {
 725         struct sm_state *one_sm, *two_sm;
 726         struct state_list *results = NULL;
 727
 728         PREPARE_PTR_LIST(*slist, one_sm);
 729         PREPARE_PTR_LIST(filter, two_sm);
 730         for (;;) {
 731                 if (!one_sm && !two_sm)
 732                         break;
 733                 if (cmp_tracker(one_sm, two_sm) < 0) {
 734                         add_ptr_list(&results, one_sm);
 735                         NEXT_PTR_LIST(one_sm);
 736                 } else if (cmp_tracker(one_sm, two_sm) == 0) {
 737                         if (one_sm != two_sm)
 738                                 add_ptr_list(&results, one_sm);
 739                         NEXT_PTR_LIST(one_sm);
 740                         NEXT_PTR_LIST(two_sm);
 741                 } else {
 742                         NEXT_PTR_LIST(two_sm);
 743                 }
 744         }
 745         FINISH_PTR_LIST(two_sm);
 746         FINISH_PTR_LIST(one_sm);
 747
 748         free_slist(slist);
 749         *slist = results;
 750 }
 751
 752 /*
 753  * and_slist_stack() pops the top two slists, overwriting the one with
 754  * the other and pushing it back on the stack.
 755  */
 756 void and_slist_stack(struct state_list_stack **slist_stack)
 757 {
 758         struct sm_state *tmp;
 759         struct state_list *right_slist = pop_slist(slist_stack);
 760
 761         FOR_EACH_PTR(right_slist, tmp) {
 762                 overwrite_sm_state_stack(slist_stack, tmp);
 763         } END_FOR_EACH_PTR(tmp);
 764         free_slist(&right_slist);
 765 }
 766
 767 /*
 768  * or_slist_stack() is for if we have:  if (foo || bar) { foo->baz;
 769  * It pops the two slists from the top of the stack and merges them
 770  * together in a way that preserves the things they have in common
 771  * but creates a merged state for most of the rest.
 772  * You could have code that had:  if (foo || foo) { foo->baz;
 773  * It's this function which ensures smatch does the right thing.
 774  */
 775 void or_slist_stack(struct state_list_stack **pre_conds,
 776                     struct state_list *cur_slist,
 777                     struct state_list_stack **slist_stack)
 778 {
 779         struct state_list *new;
 780         struct state_list *old;
 781         struct state_list *pre_slist;
 782         struct state_list *res;
 783         struct state_list *tmp_slist;
 784
 785         new = pop_slist(slist_stack);
 786         old = pop_slist(slist_stack);
 787
 788         pre_slist = pop_slist(pre_conds);
 789         push_slist(pre_conds, clone_slist(pre_slist));
 790
 791         res = clone_slist(pre_slist);
 792         overwrite_slist(old, &res);
 793
 794         tmp_slist = clone_slist(cur_slist);
 795         overwrite_slist(new, &tmp_slist);
 796
 797         merge_slist(&res, tmp_slist);
 798         filter_slist(&res, pre_slist);
 799
 800         push_slist(slist_stack, res);
 801         free_slist(&tmp_slist);
 802         free_slist(&pre_slist);
 803         free_slist(&new);
 804         free_slist(&old);
 805 }
 806
 807 /*
 808  * get_slist_from_named_stack() is only used for gotos.
 809  */
 810 struct state_list **get_slist_from_named_stack(struct named_stack *stack,
 811                                               const char *name)
 812 {
 813         struct named_slist *tmp;
 814
 815         FOR_EACH_PTR(stack, tmp) {
 816                 if (!strcmp(tmp->name, name))
 817                         return &tmp->slist;
 818         } END_FOR_EACH_PTR(tmp);
 819         return NULL;
 820 }
 821
 822 void overwrite_slist(struct state_list *from, struct state_list **to)
 823 {
 824         struct sm_state *tmp;
 825
 826         FOR_EACH_PTR(from, tmp) {
 827                 overwrite_sm_state(to, tmp);
 828         } END_FOR_EACH_PTR(tmp);
 829 }