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[smatch.git] / smatch_slist.c
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1 /*
2 * sparse/smatch_slist.c
4 * Copyright (C) 2008,2009 Dan Carpenter.
6 * Licensed under the Open Software License version 1.1
8 */
10 #include <stdlib.h>
11 #include <stdio.h>
12 #include "smatch.h"
13 #include "smatch_slist.h"
15 #undef CHECKORDER
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);
22 static int sm_state_counter;
24 char *show_sm(struct sm_state *sm)
26 static char buf[256];
27 struct sm_state *tmp;
28 int pos;
29 int i;
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;
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, ")");
49 return buf;
51 truncate:
52 for (i = 0; i < 3; i++)
53 buf[sizeof(buf) - 2 - i] = '.';
54 return buf;
57 void __print_slist(struct state_list *slist)
59 struct sm_state *sm;
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");
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)
71 int ret;
73 if (a == b)
74 return 0;
75 if (!b)
76 return -1;
77 if (!a)
78 return 1;
80 if (a->owner > b->owner)
81 return -1;
82 if (a->owner < b->owner)
83 return 1;
85 ret = strcmp(a->name, b->name);
86 if (ret)
87 return ret;
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;
98 return 0;
101 static int cmp_sm_states(const struct sm_state *a, const struct sm_state *b)
103 int ret;
105 ret = cmp_tracker(a, b);
106 if (ret)
107 return ret;
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;
117 static struct sm_state *alloc_sm_state(int owner, const char *name,
118 struct symbol *sym, struct smatch_state *state)
120 struct sm_state *sm_state = __alloc_sm_state(0);
122 sm_state_counter++;
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;
140 static struct sm_state *alloc_state_no_name(int owner, const char *name,
141 struct symbol *sym,
142 struct smatch_state *state)
144 struct sm_state *tmp;
146 tmp = alloc_sm_state(owner, NULL, sym, state);
147 tmp->name = name;
148 return tmp;
151 void add_sm_state_slist(struct state_list **slist, struct sm_state *new)
153 struct sm_state *tmp;
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;
164 } END_FOR_EACH_PTR(tmp);
165 add_ptr_list(slist, new);
168 static void copy_possibles(struct sm_state *to, struct sm_state *from)
170 struct sm_state *tmp;
172 FOR_EACH_PTR(from->possible, tmp) {
173 add_sm_state_slist(&to->possible, tmp);
174 } END_FOR_EACH_PTR(tmp);
177 char *alloc_sname(const char *str)
179 char *tmp;
181 if (!str)
182 return NULL;
183 tmp = __alloc_sname(strlen(str) + 1);
184 strcpy(tmp, str);
185 return tmp;
188 int out_of_memory()
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.
195 if (sm_state_counter * sizeof(struct sm_state) >= 50000000)
196 return 1;
197 return 0;
200 static void free_sm_state(struct sm_state *sm)
202 free_slist(&sm->possible);
204 * fixme. Free the actual state.
205 * Right now we leave it until the end of the function
206 * because we don't want to double free it.
207 * Use the freelist to not double free things
211 static void free_all_sm_states(struct allocation_blob *blob)
213 unsigned int size = sizeof(struct sm_state);
214 unsigned int offset = 0;
216 while (offset < blob->offset) {
217 free_sm_state((struct sm_state *)(blob->data + offset));
218 offset += size;
222 /* At the end of every function we free all the sm_states */
223 void free_every_single_sm_state(void)
225 struct allocator_struct *desc = &sm_state_allocator;
226 struct allocation_blob *blob = desc->blobs;
228 desc->blobs = NULL;
229 desc->allocations = 0;
230 desc->total_bytes = 0;
231 desc->useful_bytes = 0;
232 desc->freelist = NULL;
233 while (blob) {
234 struct allocation_blob *next = blob->next;
235 free_all_sm_states(blob);
236 blob_free(blob, desc->chunking);
237 blob = next;
239 clear_sname_alloc();
241 sm_state_counter = 0;
244 struct sm_state *clone_sm(struct sm_state *s)
246 struct sm_state *ret;
248 ret = alloc_state_no_name(s->owner, s->name, s->sym, s->state);
249 ret->merged = s->merged;
250 ret->implied = s->implied;
251 ret->line = s->line;
252 /* clone_sm() doesn't copy the pools. Each state needs to have
253 only one pool. */
254 ret->possible = clone_slist(s->possible);
255 ret->left = s->left;
256 ret->right = s->right;
257 ret->nr_children = s->nr_children;
258 return ret;
261 int is_merged(struct sm_state *sm)
263 return sm->merged;
266 int is_implied(struct sm_state *sm)
268 return sm->implied;
271 int slist_has_state(struct state_list *slist, struct smatch_state *state)
273 struct sm_state *tmp;
275 FOR_EACH_PTR(slist, tmp) {
276 if (tmp->state == state)
277 return 1;
278 } END_FOR_EACH_PTR(tmp);
279 return 0;
282 static void check_order(struct state_list *slist)
284 #ifdef CHECKORDER
285 struct sm_state *sm;
286 struct sm_state *last = NULL;
287 int printed = 0;
289 FOR_EACH_PTR(slist, sm) {
290 if (last && cmp_tracker(sm, last) <= 0) {
291 printf("Error. Unsorted slist %d vs %d, %p vs %p, "
292 "%s vs %s\n", last->owner, sm->owner,
293 last->sym, sm->sym, last->name, sm->name);
294 printed = 1;
296 last = state;
297 } END_FOR_EACH_PTR(sm);
299 if (printed)
300 printf("======\n");
301 #endif
304 struct state_list *clone_slist(struct state_list *from_slist)
306 struct sm_state *sm;
307 struct state_list *to_slist = NULL;
309 FOR_EACH_PTR(from_slist, sm) {
310 add_ptr_list(&to_slist, sm);
311 } END_FOR_EACH_PTR(sm);
312 check_order(to_slist);
313 return to_slist;
316 struct state_list_stack *clone_stack(struct state_list_stack *from_stack)
318 struct state_list *slist;
319 struct state_list_stack *to_stack = NULL;
321 FOR_EACH_PTR(from_stack, slist) {
322 push_slist(&to_stack, slist);
323 } END_FOR_EACH_PTR(slist);
324 return to_stack;
327 struct smatch_state *merge_states(int owner, const char *name,
328 struct symbol *sym,
329 struct smatch_state *state1,
330 struct smatch_state *state2)
332 struct smatch_state *ret;
334 if (state1 == state2)
335 ret = state1;
336 else if (__has_merge_function(owner))
337 ret = __client_merge_function(owner, state1, state2);
338 else if (!state1 || !state2)
339 ret = &undefined;
340 else
341 ret = &merged;
342 return ret;
345 struct sm_state *merge_sm_states(struct sm_state *one, struct sm_state *two)
347 struct smatch_state *s;
348 struct sm_state *result;
350 if (one == two)
351 return one;
352 s = merge_states(one->owner, one->name, one->sym, one->state, two->state);
353 result = alloc_state_no_name(one->owner, one->name, one->sym, s);
354 result->merged = 1;
355 result->left = one;
356 result->right = two;
357 result->nr_children = one->nr_children + two->nr_children;
358 copy_possibles(result, one);
359 copy_possibles(result, two);
361 if (option_debug) {
362 struct sm_state *tmp;
363 int i = 0;
365 printf("%d merge [%s] '%s' %s(L %d) + %s(L %d) => %s (",
366 get_lineno(), check_name(one->owner), one->name,
367 show_state(one->state), one->line,
368 show_state(two->state), two->line,
369 show_state(s));
371 FOR_EACH_PTR(result->possible, tmp) {
372 if (i++)
373 printf(", ");
374 printf("%s", show_state(tmp->state));
375 } END_FOR_EACH_PTR(tmp);
376 printf(")\n");
379 return result;
382 struct sm_state *get_sm_state_slist(struct state_list *slist, int owner, const char *name,
383 struct symbol *sym)
385 struct sm_state *sm;
387 if (!name)
388 return NULL;
390 FOR_EACH_PTR(slist, sm) {
391 if (sm->owner == owner && sm->sym == sym && !strcmp(sm->name, name))
392 return sm;
393 } END_FOR_EACH_PTR(sm);
394 return NULL;
397 struct smatch_state *get_state_slist(struct state_list *slist,
398 int owner, const char *name,
399 struct symbol *sym)
401 struct sm_state *sm;
403 sm = get_sm_state_slist(slist, owner, name, sym);
404 if (sm)
405 return sm->state;
406 return NULL;
409 void overwrite_sm_state(struct state_list **slist, struct sm_state *new)
411 struct sm_state *tmp;
413 FOR_EACH_PTR(*slist, tmp) {
414 if (cmp_tracker(tmp, new) < 0)
415 continue;
416 else if (cmp_tracker(tmp, new) == 0) {
417 REPLACE_CURRENT_PTR(tmp, new);
418 return;
419 } else {
420 INSERT_CURRENT(new, tmp);
421 return;
423 } END_FOR_EACH_PTR(tmp);
424 add_ptr_list(slist, new);
427 void overwrite_sm_state_stack(struct state_list_stack **stack,
428 struct sm_state *sm)
430 struct state_list *slist;
432 slist = pop_slist(stack);
433 overwrite_sm_state(&slist, sm);
434 push_slist(stack, slist);
437 struct sm_state *set_state_slist(struct state_list **slist, int owner, const char *name,
438 struct symbol *sym, struct smatch_state *state)
440 struct sm_state *tmp;
441 struct sm_state *new = alloc_sm_state(owner, name, sym, state);
443 FOR_EACH_PTR(*slist, tmp) {
444 if (cmp_tracker(tmp, new) < 0)
445 continue;
446 else if (cmp_tracker(tmp, new) == 0) {
447 REPLACE_CURRENT_PTR(tmp, new);
448 return new;
449 } else {
450 INSERT_CURRENT(new, tmp);
451 return new;
453 } END_FOR_EACH_PTR(tmp);
454 add_ptr_list(slist, new);
455 return new;
458 void delete_state_slist(struct state_list **slist, int owner, const char *name,
459 struct symbol *sym)
461 struct sm_state *sm;
463 FOR_EACH_PTR(*slist, sm) {
464 if (sm->owner == owner && sm->sym == sym && !strcmp(sm->name, name)) {
465 DELETE_CURRENT_PTR(sm);
466 return;
468 } END_FOR_EACH_PTR(sm);
471 void delete_state_stack(struct state_list_stack **stack, int owner, const char *name,
472 struct symbol *sym)
474 struct state_list *slist;
476 slist = pop_slist(stack);
477 delete_state_slist(&slist, owner, name, sym);
478 push_slist(stack, slist);
481 void push_slist(struct state_list_stack **list_stack, struct state_list *slist)
483 add_ptr_list(list_stack, slist);
486 struct state_list *pop_slist(struct state_list_stack **list_stack)
488 struct state_list *slist;
490 slist = last_ptr_list((struct ptr_list *)*list_stack);
491 delete_ptr_list_last((struct ptr_list **)list_stack);
492 return slist;
495 void free_slist(struct state_list **slist)
497 __free_ptr_list((struct ptr_list **)slist);
500 void free_stack(struct state_list_stack **stack)
502 __free_ptr_list((struct ptr_list **)stack);
505 void free_stack_and_slists(struct state_list_stack **slist_stack)
507 struct state_list *slist;
509 FOR_EACH_PTR(*slist_stack, slist) {
510 free_slist(&slist);
511 } END_FOR_EACH_PTR(slist);
512 free_stack(slist_stack);
516 * set_state_stack() sets the state for the top slist on the stack.
518 struct sm_state *set_state_stack(struct state_list_stack **stack, int owner, const char *name,
519 struct symbol *sym, struct smatch_state *state)
521 struct state_list *slist;
522 struct sm_state *sm;
524 slist = pop_slist(stack);
525 sm = set_state_slist(&slist, owner, name, sym, state);
526 push_slist(stack, slist);
528 return sm;
532 * get_sm_state_stack() gets the state for the top slist on the stack.
534 struct sm_state *get_sm_state_stack(struct state_list_stack *stack,
535 int owner, const char *name,
536 struct symbol *sym)
538 struct state_list *slist;
539 struct sm_state *ret;
541 slist = pop_slist(&stack);
542 ret = get_sm_state_slist(slist, owner, name, sym);
543 push_slist(&stack, slist);
544 return ret;
547 struct smatch_state *get_state_stack(struct state_list_stack *stack,
548 int owner, const char *name,
549 struct symbol *sym)
551 struct sm_state *sm;
553 sm = get_sm_state_stack(stack, owner, name, sym);
554 if (sm)
555 return sm->state;
556 return NULL;
559 static void match_states(struct state_list **one, struct state_list **two)
561 struct sm_state *one_sm;
562 struct sm_state *two_sm;
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;
568 PREPARE_PTR_LIST(*one, one_sm);
569 PREPARE_PTR_LIST(*two, two_sm);
570 for (;;) {
571 if (!one_sm && !two_sm)
572 break;
573 if (cmp_tracker(one_sm, two_sm) < 0) {
574 tmp_state = __client_unmatched_state_function(one_sm);
575 tmp = alloc_state_no_name(one_sm->owner, one_sm->name,
576 one_sm->sym, tmp_state);
577 add_ptr_list(&add_to_two, tmp);
578 NEXT_PTR_LIST(one_sm);
579 } else if (cmp_tracker(one_sm, two_sm) == 0) {
580 NEXT_PTR_LIST(one_sm);
581 NEXT_PTR_LIST(two_sm);
582 } else {
583 tmp_state = __client_unmatched_state_function(two_sm);
584 tmp = alloc_state_no_name(two_sm->owner, two_sm->name,
585 two_sm->sym, tmp_state);
586 add_ptr_list(&add_to_one, tmp);
587 NEXT_PTR_LIST(two_sm);
590 FINISH_PTR_LIST(two_sm);
591 FINISH_PTR_LIST(one_sm);
593 overwrite_slist(add_to_one, one);
594 overwrite_slist(add_to_two, two);
597 static void clone_pool_havers(struct state_list *slist)
599 struct sm_state *sm;
600 struct sm_state *new;
602 FOR_EACH_PTR(slist, sm) {
603 if (sm->pool) {
604 new = clone_sm(sm);
605 REPLACE_CURRENT_PTR(sm, new);
607 } END_FOR_EACH_PTR(sm);
610 int __slist_id;
612 * Sets the first state to the slist_id.
614 static void set_slist_id(struct state_list *slist)
616 struct smatch_state *state;
617 struct sm_state *tmp, *new;
619 state = alloc_state_num(++__slist_id);
620 new = alloc_sm_state(-1, "unnull_path", NULL, state);
622 FOR_EACH_PTR(slist, tmp) {
623 if (tmp->owner != (unsigned short)-1)
624 return;
625 REPLACE_CURRENT_PTR(tmp, new);
626 return;
627 } END_FOR_EACH_PTR(tmp);
630 int get_slist_id(struct state_list *slist)
632 struct sm_state *tmp;
634 FOR_EACH_PTR(slist, tmp) {
635 if (tmp->owner != (unsigned short)-1)
636 return 0;
637 return PTR_INT(tmp->state->data);
638 } END_FOR_EACH_PTR(tmp);
639 return 0;
643 * merge_slist() is called whenever paths merge, such as after
644 * an if statement. It takes the two slists and creates one.
646 void merge_slist(struct state_list **to, struct state_list *slist)
648 struct sm_state *one_sm, *two_sm, *tmp;
649 struct state_list *results = NULL;
650 struct state_list *implied_one = NULL;
651 struct state_list *implied_two = NULL;
653 if (out_of_memory())
654 return;
656 check_order(*to);
657 check_order(slist);
659 /* merging a null and nonnull path gives you only the nonnull path */
660 if (!slist)
661 return;
663 if (!*to) {
664 *to = clone_slist(slist);
665 return;
668 implied_one = clone_slist(*to);
669 implied_two = clone_slist(slist);
671 match_states(&implied_one, &implied_two);
673 clone_pool_havers(implied_one);
674 clone_pool_havers(implied_two);
676 set_slist_id(implied_one);
677 set_slist_id(implied_two);
679 PREPARE_PTR_LIST(implied_one, one_sm);
680 PREPARE_PTR_LIST(implied_two, two_sm);
681 for (;;) {
682 if (!one_sm && !two_sm)
683 break;
684 if (cmp_tracker(one_sm, two_sm) < 0) {
685 sm_msg("error: Internal smatch error.");
686 NEXT_PTR_LIST(one_sm);
687 } else if (cmp_tracker(one_sm, two_sm) == 0) {
688 if (one_sm != two_sm) {
689 one_sm->pool = implied_one;
690 two_sm->pool = implied_two;
693 tmp = merge_sm_states(one_sm, two_sm);
694 add_ptr_list(&results, tmp);
695 NEXT_PTR_LIST(one_sm);
696 NEXT_PTR_LIST(two_sm);
697 } else {
698 sm_msg("error: Internal smatch error.");
699 NEXT_PTR_LIST(two_sm);
702 FINISH_PTR_LIST(two_sm);
703 FINISH_PTR_LIST(one_sm);
705 free_slist(to);
706 *to = results;
710 * filter_slist() removes any sm states "slist" holds in common with "filter"
712 void filter_slist(struct state_list **slist, struct state_list *filter)
714 struct sm_state *one_sm, *two_sm;
715 struct state_list *results = NULL;
717 PREPARE_PTR_LIST(*slist, one_sm);
718 PREPARE_PTR_LIST(filter, two_sm);
719 for (;;) {
720 if (!one_sm && !two_sm)
721 break;
722 if (cmp_tracker(one_sm, two_sm) < 0) {
723 add_ptr_list(&results, one_sm);
724 NEXT_PTR_LIST(one_sm);
725 } else if (cmp_tracker(one_sm, two_sm) == 0) {
726 if (one_sm != two_sm)
727 add_ptr_list(&results, one_sm);
728 NEXT_PTR_LIST(one_sm);
729 NEXT_PTR_LIST(two_sm);
730 } else {
731 NEXT_PTR_LIST(two_sm);
734 FINISH_PTR_LIST(two_sm);
735 FINISH_PTR_LIST(one_sm);
737 free_slist(slist);
738 *slist = results;
742 * and_slist_stack() pops the top two slists, overwriting the one with
743 * the other and pushing it back on the stack.
745 void and_slist_stack(struct state_list_stack **slist_stack)
747 struct sm_state *tmp;
748 struct state_list *right_slist = pop_slist(slist_stack);
750 FOR_EACH_PTR(right_slist, tmp) {
751 overwrite_sm_state_stack(slist_stack, tmp);
752 } END_FOR_EACH_PTR(tmp);
753 free_slist(&right_slist);
757 * or_slist_stack() is for if we have: if (foo || bar) { foo->baz;
758 * It pops the two slists from the top of the stack and merges them
759 * together in a way that preserves the things they have in common
760 * but creates a merged state for most of the rest.
761 * You could have code that had: if (foo || foo) { foo->baz;
762 * It's this function which ensures smatch does the right thing.
764 void or_slist_stack(struct state_list_stack **pre_conds,
765 struct state_list *cur_slist,
766 struct state_list_stack **slist_stack)
768 struct state_list *new;
769 struct state_list *old;
770 struct state_list *pre_slist;
771 struct state_list *res;
772 struct state_list *tmp_slist;
774 new = pop_slist(slist_stack);
775 old = pop_slist(slist_stack);
777 pre_slist = pop_slist(pre_conds);
778 push_slist(pre_conds, clone_slist(pre_slist));
780 res = clone_slist(pre_slist);
781 overwrite_slist(old, &res);
783 tmp_slist = clone_slist(cur_slist);
784 overwrite_slist(new, &tmp_slist);
786 merge_slist(&res, tmp_slist);
787 filter_slist(&res, pre_slist);
789 push_slist(slist_stack, res);
790 free_slist(&tmp_slist);
791 free_slist(&pre_slist);
792 free_slist(&new);
793 free_slist(&old);
797 * get_slist_from_named_stack() is only used for gotos.
799 struct state_list **get_slist_from_named_stack(struct named_stack *stack,
800 const char *name)
802 struct named_slist *tmp;
804 FOR_EACH_PTR(stack, tmp) {
805 if (!strcmp(tmp->name, name))
806 return &tmp->slist;
807 } END_FOR_EACH_PTR(tmp);
808 return NULL;
811 void overwrite_slist(struct state_list *from, struct state_list **to)
813 struct sm_state *tmp;
815 FOR_EACH_PTR(from, tmp) {
816 overwrite_sm_state(to, tmp);
817 } END_FOR_EACH_PTR(tmp);