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