2 * Copyright (C) 2006 Dan Carpenter.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version 2
7 * of the License, or (at your option) any later version.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, see http://www.gnu.org/copyleft/gpl.txt
19 * You have a lists of states. kernel = locked, foo = NULL, ...
20 * When you hit an if {} else {} statement then you swap the list
21 * of states for a different list of states. The lists are stored
24 * At the beginning of this file there are list of the stacks that
25 * we use. Each function in this file does something to one of
28 * So the smatch_flow.c understands code but it doesn't understand states.
29 * smatch_flow calls functions in this file. This file calls functions
30 * in smatch_slist.c which just has boring generic plumbing for handling
31 * state lists. But really it's this file where all the magic happens.
37 #include "smatch_slist.h"
38 #include "smatch_extra.h"
40 struct smatch_state undefined
= { .name
= "undefined" };
41 struct smatch_state ghost
= { .name
= "ghost" };
42 struct smatch_state merged
= { .name
= "merged" };
43 struct smatch_state true_state
= { .name
= "true" };
44 struct smatch_state false_state
= { .name
= "false" };
46 static struct stree
*cur_stree
; /* current states */
48 static struct stree_stack
*true_stack
; /* states after a t/f branch */
49 static struct stree_stack
*false_stack
;
50 static struct stree_stack
*pre_cond_stack
; /* states before a t/f branch */
52 static struct stree_stack
*cond_true_stack
; /* states affected by a branch */
53 static struct stree_stack
*cond_false_stack
;
55 static struct stree_stack
*fake_cur_stree_stack
;
58 static struct stree_stack
*break_stack
;
59 static struct stree_stack
*switch_stack
;
60 static struct range_list_stack
*remaining_cases
;
61 static struct stree_stack
*default_stack
;
62 static struct stree_stack
*continue_stack
;
64 static struct named_stree_stack
*goto_stack
;
66 static struct ptr_list
*backup
;
70 void __print_cur_stree(void)
72 __print_stree(cur_stree
);
82 struct sm_state
*set_state(int owner
, const char *name
, struct symbol
*sym
, struct smatch_state
*state
)
90 sm_msg("Smatch Internal Error: cur_stree is read only.");
92 if (option_debug
|| strcmp(check_name(owner
), option_debug_check
) == 0) {
93 struct smatch_state
*s
;
95 s
= get_state(owner
, name
, sym
);
97 sm_msg("new state. name='%s' [%s] %s",
98 name
, check_name(owner
), show_state(state
));
100 sm_msg("state change name='%s' [%s] %s => %s",
101 name
, check_name(owner
), show_state(s
),
105 if (owner
!= -1 && unreachable())
108 if (fake_cur_stree_stack
)
109 set_state_stree_stack(&fake_cur_stree_stack
, owner
, name
, sym
, state
);
111 ret
= set_state_stree(&cur_stree
, owner
, name
, sym
, state
);
116 struct sm_state
*set_state_expr(int owner
, struct expression
*expr
, struct smatch_state
*state
)
120 struct sm_state
*ret
= NULL
;
122 expr
= strip_expr(expr
);
123 name
= expr_to_var_sym(expr
, &sym
);
126 ret
= set_state(owner
, name
, sym
, state
);
132 void __swap_cur_stree(struct stree
*stree
)
134 free_stree(&cur_stree
);
138 void __push_fake_cur_stree(void)
140 push_stree(&fake_cur_stree_stack
, NULL
);
141 __save_pre_cond_states();
144 struct stree
*__pop_fake_cur_stree(void)
146 if (!fake_cur_stree_stack
)
147 sm_msg("INTERNAL error: popping too many fake cur strees.");
148 __use_pre_cond_states();
149 return pop_stree(&fake_cur_stree_stack
);
152 void __free_fake_cur_stree(void)
156 stree
= __pop_fake_cur_stree();
160 void __set_fake_cur_stree_fast(struct stree
*stree
)
162 push_stree(&pre_cond_stack
, cur_stree
);
167 void __pop_fake_cur_stree_fast(void)
169 cur_stree
= pop_stree(&pre_cond_stack
);
173 void __merge_stree_into_cur(struct stree
*stree
)
176 struct sm_state
*orig
;
177 struct sm_state
*merged
;
179 FOR_EACH_SM(stree
, sm
) {
180 orig
= get_sm_state(sm
->owner
, sm
->name
, sm
->sym
);
182 merged
= merge_sm_states(orig
, sm
);
186 } END_FOR_EACH_SM(sm
);
189 void __set_sm(struct sm_state
*sm
)
192 sm_msg("Smatch Internal Error: cur_stree is read only.");
195 strcmp(check_name(sm
->owner
), option_debug_check
) == 0) {
196 struct smatch_state
*s
;
198 s
= get_state(sm
->owner
, sm
->name
, sm
->sym
);
200 sm_msg("new state. name='%s' [%s] %s",
201 sm
->name
, check_name(sm
->owner
),
202 show_state(sm
->state
));
204 sm_msg("state change name='%s' [%s] %s => %s",
205 sm
->name
, check_name(sm
->owner
), show_state(s
),
206 show_state(sm
->state
));
212 if (fake_cur_stree_stack
)
213 overwrite_sm_state_stree_stack(&fake_cur_stree_stack
, sm
);
215 overwrite_sm_state_stree(&cur_stree
, sm
);
218 void __set_sm_cur_stree(struct sm_state
*sm
)
221 sm_msg("Smatch Internal Error: cur_stree is read only.");
224 strcmp(check_name(sm
->owner
), option_debug_check
) == 0) {
225 struct smatch_state
*s
;
227 s
= get_state(sm
->owner
, sm
->name
, sm
->sym
);
229 sm_msg("new state. name='%s' [%s] %s",
230 sm
->name
, check_name(sm
->owner
),
231 show_state(sm
->state
));
233 sm_msg("state change name='%s' [%s] %s => %s",
234 sm
->name
, check_name(sm
->owner
), show_state(s
),
235 show_state(sm
->state
));
241 overwrite_sm_state_stree(&cur_stree
, sm
);
244 void __set_sm_fake_stree(struct sm_state
*sm
)
247 sm_msg("Smatch Internal Error: cur_stree is read only.");
250 strcmp(check_name(sm
->owner
), option_debug_check
) == 0) {
251 struct smatch_state
*s
;
253 s
= get_state(sm
->owner
, sm
->name
, sm
->sym
);
255 sm_msg("new state. name='%s' [%s] %s",
256 sm
->name
, check_name(sm
->owner
),
257 show_state(sm
->state
));
259 sm_msg("state change name='%s' [%s] %s => %s",
260 sm
->name
, check_name(sm
->owner
), show_state(s
),
261 show_state(sm
->state
));
267 overwrite_sm_state_stree_stack(&fake_cur_stree_stack
, sm
);
270 struct smatch_state
*get_state(int owner
, const char *name
, struct symbol
*sym
)
272 __get_state_hook(owner
, name
, sym
);
274 return get_state_stree(cur_stree
, owner
, name
, sym
);
277 struct smatch_state
*get_state_expr(int owner
, struct expression
*expr
)
281 struct smatch_state
*ret
= NULL
;
283 expr
= strip_expr(expr
);
284 name
= expr_to_var_sym(expr
, &sym
);
287 ret
= get_state(owner
, name
, sym
);
293 struct state_list
*get_possible_states(int owner
, const char *name
, struct symbol
*sym
)
295 struct sm_state
*sms
;
297 sms
= get_sm_state_stree(cur_stree
, owner
, name
, sym
);
299 return sms
->possible
;
303 struct state_list
*get_possible_states_expr(int owner
, struct expression
*expr
)
307 struct state_list
*ret
= NULL
;
309 expr
= strip_expr(expr
);
310 name
= expr_to_var_sym(expr
, &sym
);
313 ret
= get_possible_states(owner
, name
, sym
);
319 struct sm_state
*get_sm_state(int owner
, const char *name
, struct symbol
*sym
)
321 return get_sm_state_stree(cur_stree
, owner
, name
, sym
);
324 struct sm_state
*get_sm_state_expr(int owner
, struct expression
*expr
)
328 struct sm_state
*ret
= NULL
;
330 expr
= strip_expr(expr
);
331 name
= expr_to_var_sym(expr
, &sym
);
334 ret
= get_sm_state(owner
, name
, sym
);
340 void delete_state(int owner
, const char *name
, struct symbol
*sym
)
342 delete_state_stree(&cur_stree
, owner
, name
, sym
);
343 if (cond_true_stack
) {
344 delete_state_stree_stack(&pre_cond_stack
, owner
, name
, sym
);
345 delete_state_stree_stack(&cond_true_stack
, owner
, name
, sym
);
346 delete_state_stree_stack(&cond_false_stack
, owner
, name
, sym
);
350 void delete_state_expr(int owner
, struct expression
*expr
)
355 expr
= strip_expr(expr
);
356 name
= expr_to_var_sym(expr
, &sym
);
359 delete_state(owner
, name
, sym
);
364 struct stree
*get_all_states_from_stree(int owner
, struct stree
*source
)
366 struct stree
*ret
= NULL
;
367 struct sm_state
*tmp
;
369 FOR_EACH_SM(source
, tmp
) {
370 if (tmp
->owner
== owner
)
371 avl_insert(&ret
, tmp
);
372 } END_FOR_EACH_SM(tmp
);
377 struct stree
*get_all_states_stree(int owner
)
379 return get_all_states_from_stree(owner
, cur_stree
);
382 struct stree
*__get_cur_stree(void)
387 int is_reachable(void)
394 void set_true_false_states(int owner
, const char *name
, struct symbol
*sym
,
395 struct smatch_state
*true_state
,
396 struct smatch_state
*false_state
)
399 sm_msg("Smatch Internal Error: cur_stree is read only.");
401 if (option_debug
|| strcmp(check_name(owner
), option_debug_check
) == 0) {
402 struct smatch_state
*tmp
;
404 tmp
= get_state(owner
, name
, sym
);
405 sm_msg("set_true_false '%s'. Was %s. Now T:%s F:%s\n",
406 name
, show_state(tmp
),
407 show_state(true_state
), show_state(false_state
));
413 if (!cond_false_stack
|| !cond_true_stack
) {
414 printf("Error: missing true/false stacks\n");
419 set_state_stree_stack(&cond_true_stack
, owner
, name
, sym
, true_state
);
421 set_state_stree_stack(&cond_false_stack
, owner
, name
, sym
, false_state
);
424 void set_true_false_states_expr(int owner
, struct expression
*expr
,
425 struct smatch_state
*true_state
,
426 struct smatch_state
*false_state
)
431 expr
= strip_expr(expr
);
432 name
= expr_to_var_sym(expr
, &sym
);
435 set_true_false_states(owner
, name
, sym
, true_state
, false_state
);
440 void __set_true_false_sm(struct sm_state
*true_sm
, struct sm_state
*false_sm
)
445 if (!cond_false_stack
|| !cond_true_stack
) {
446 printf("Error: missing true/false stacks\n");
451 overwrite_sm_state_stree_stack(&cond_true_stack
, true_sm
);
453 overwrite_sm_state_stree_stack(&cond_false_stack
, false_sm
);
456 void __set_true_false_sm_if_not_already_set(struct sm_state
*true_sm
, struct sm_state
*false_sm
)
461 if (!cond_false_stack
|| !cond_true_stack
) {
462 printf("Error: missing true/false stacks\n");
467 set_sm_state_stree_stack_if_not_already_set(&cond_true_stack
, true_sm
);
469 set_sm_state_stree_stack_if_not_already_set(&cond_false_stack
, false_sm
);
472 void nullify_path(void)
474 free_stree(&cur_stree
);
477 void __match_nullify_path_hook(const char *fn
, struct expression
*expr
,
484 * At the start of every function we mark the path
485 * as unnull. That way there is always at least one state
486 * in the cur_stree until nullify_path is called. This
487 * is used in merge_slist() for the first null check.
489 void __unnullify_path(void)
492 set_state(-1, "unnull_path", NULL
, &true_state
);
495 int __path_is_null(void)
502 static void check_stree_stack_free(struct stree_stack
**stack
)
505 sm_msg("smatch internal error: stack not empty");
506 free_stack_and_strees(stack
);
510 void save_all_states(void)
512 __add_ptr_list(&backup
, cur_stree
, 0);
515 __add_ptr_list(&backup
, true_stack
, 0);
517 __add_ptr_list(&backup
, false_stack
, 0);
519 __add_ptr_list(&backup
, pre_cond_stack
, 0);
520 pre_cond_stack
= NULL
;
522 __add_ptr_list(&backup
, cond_true_stack
, 0);
523 cond_true_stack
= NULL
;
524 __add_ptr_list(&backup
, cond_false_stack
, 0);
525 cond_false_stack
= NULL
;
527 __add_ptr_list(&backup
, fake_cur_stree_stack
, 0);
528 fake_cur_stree_stack
= NULL
;
530 __add_ptr_list(&backup
, break_stack
, 0);
532 __add_ptr_list(&backup
, switch_stack
, 0);
534 __add_ptr_list(&backup
, remaining_cases
, 0);
535 remaining_cases
= NULL
;
536 __add_ptr_list(&backup
, default_stack
, 0);
537 default_stack
= NULL
;
538 __add_ptr_list(&backup
, continue_stack
, 0);
539 continue_stack
= NULL
;
541 __add_ptr_list(&backup
, goto_stack
, 0);
545 static void *pop_backup(void)
549 ret
= last_ptr_list(backup
);
550 delete_ptr_list_last(&backup
);
554 void restore_all_states(void)
556 goto_stack
= pop_backup();
558 continue_stack
= pop_backup();
559 default_stack
= pop_backup();
560 remaining_cases
= pop_backup();
561 switch_stack
= pop_backup();
562 break_stack
= pop_backup();
564 fake_cur_stree_stack
= pop_backup();
566 cond_false_stack
= pop_backup();
567 cond_true_stack
= pop_backup();
569 pre_cond_stack
= pop_backup();
570 false_stack
= pop_backup();
571 true_stack
= pop_backup();
573 cur_stree
= pop_backup();
576 void free_goto_stack(void)
578 struct named_stree
*named_stree
;
580 FOR_EACH_PTR(goto_stack
, named_stree
) {
581 free_stree(&named_stree
->stree
);
582 } END_FOR_EACH_PTR(named_stree
);
583 __free_ptr_list((struct ptr_list
**)&goto_stack
);
586 void clear_all_states(void)
589 check_stree_stack_free(&true_stack
);
590 check_stree_stack_free(&false_stack
);
591 check_stree_stack_free(&pre_cond_stack
);
592 check_stree_stack_free(&cond_true_stack
);
593 check_stree_stack_free(&cond_false_stack
);
594 check_stree_stack_free(&break_stack
);
595 check_stree_stack_free(&switch_stack
);
596 check_stree_stack_free(&continue_stack
);
597 check_stree_stack_free(&fake_cur_stree_stack
);
601 free_every_single_sm_state();
604 void __push_cond_stacks(void)
606 push_stree(&cond_true_stack
, NULL
);
607 push_stree(&cond_false_stack
, NULL
);
608 __push_fake_cur_stree();
611 void __fold_in_set_states(void)
613 struct stree
*new_states
;
616 new_states
= __pop_fake_cur_stree();
617 FOR_EACH_SM(new_states
, sm
) {
619 __set_true_false_sm(sm
, sm
);
620 } END_FOR_EACH_SM(sm
);
621 free_stree(&new_states
);
624 void __free_set_states(void)
626 struct stree
*new_states
;
628 new_states
= __pop_fake_cur_stree();
629 free_stree(&new_states
);
632 struct stree
*__copy_cond_true_states(void)
636 ret
= pop_stree(&cond_true_stack
);
637 push_stree(&cond_true_stack
, clone_stree(ret
));
641 struct stree
*__copy_cond_false_states(void)
645 ret
= pop_stree(&cond_false_stack
);
646 push_stree(&cond_false_stack
, clone_stree(ret
));
650 struct stree
*__pop_cond_true_stack(void)
652 return pop_stree(&cond_true_stack
);
655 struct stree
*__pop_cond_false_stack(void)
657 return pop_stree(&cond_false_stack
);
661 * This combines the pre cond states with either the true or false states.
663 * a = kmalloc() ; if (a !! foo(a)
664 * In the pre state a is possibly null. In the true state it is non null.
665 * In the false state it is null. Combine the pre and the false to get
666 * that when we call 'foo', 'a' is null.
668 static void __use_cond_stack(struct stree_stack
**stack
)
672 free_stree(&cur_stree
);
674 cur_stree
= pop_stree(&pre_cond_stack
);
675 push_stree(&pre_cond_stack
, clone_stree(cur_stree
));
677 stree
= pop_stree(stack
);
678 overwrite_stree(stree
, &cur_stree
);
679 push_stree(stack
, stree
);
682 void __use_pre_cond_states(void)
684 free_stree(&cur_stree
);
685 cur_stree
= pop_stree(&pre_cond_stack
);
688 void __use_cond_true_states(void)
690 __use_cond_stack(&cond_true_stack
);
693 void __use_cond_false_states(void)
695 __use_cond_stack(&cond_false_stack
);
698 void __negate_cond_stacks(void)
700 struct stree
*old_false
, *old_true
;
702 __use_cond_stack(&cond_false_stack
);
703 old_false
= pop_stree(&cond_false_stack
);
704 old_true
= pop_stree(&cond_true_stack
);
705 push_stree(&cond_false_stack
, old_true
);
706 push_stree(&cond_true_stack
, old_false
);
709 void __and_cond_states(void)
711 and_stree_stack(&cond_true_stack
);
712 or_stree_stack(&pre_cond_stack
, cur_stree
, &cond_false_stack
);
715 void __or_cond_states(void)
717 or_stree_stack(&pre_cond_stack
, cur_stree
, &cond_true_stack
);
718 and_stree_stack(&cond_false_stack
);
721 void __save_pre_cond_states(void)
723 push_stree(&pre_cond_stack
, clone_stree(cur_stree
));
726 void __discard_pre_cond_states(void)
730 tmp
= pop_stree(&pre_cond_stack
);
734 struct stree
*__get_true_states(void)
736 return clone_stree(top_stree(cond_true_stack
));
739 struct stree
*__get_false_states(void)
741 return clone_stree(top_stree(cond_false_stack
));
744 void __use_cond_states(void)
746 struct stree
*pre
, *pre_clone
, *true_states
, *false_states
;
748 pre
= pop_stree(&pre_cond_stack
);
749 pre_clone
= clone_stree(pre
);
751 true_states
= pop_stree(&cond_true_stack
);
752 overwrite_stree(true_states
, &pre
);
753 free_stree(&true_states
);
754 /* we use the true states right away */
755 free_stree(&cur_stree
);
758 false_states
= pop_stree(&cond_false_stack
);
759 overwrite_stree(false_states
, &pre_clone
);
760 free_stree(&false_states
);
761 push_stree(&false_stack
, pre_clone
);
764 void __push_true_states(void)
766 push_stree(&true_stack
, clone_stree(cur_stree
));
769 void __use_false_states(void)
771 free_stree(&cur_stree
);
772 cur_stree
= pop_stree(&false_stack
);
775 void __discard_false_states(void)
779 stree
= pop_stree(&false_stack
);
783 void __merge_false_states(void)
787 stree
= pop_stree(&false_stack
);
788 merge_stree(&cur_stree
, stree
);
792 static void update_fake_stree_with_merged(void)
795 struct state_list
*slist
= NULL
;
796 struct sm_state
*sm
, *new;
798 if (!fake_cur_stree_stack
)
800 stree
= pop_stree(&fake_cur_stree_stack
);
801 FOR_EACH_SM(stree
, sm
) {
802 new = get_sm_state(sm
->owner
, sm
->name
, sm
->sym
);
805 add_ptr_list(&slist
, new);
806 } END_FOR_EACH_SM(sm
);
808 FOR_EACH_PTR(slist
, sm
) {
809 overwrite_sm_state_stree(&stree
, sm
);
810 } END_FOR_EACH_PTR(sm
);
813 push_stree(&fake_cur_stree_stack
, stree
);
816 void __merge_true_states(void)
820 stree
= pop_stree(&true_stack
);
821 merge_stree(&cur_stree
, stree
);
822 update_fake_stree_with_merged();
826 void __push_continues(void)
828 push_stree(&continue_stack
, NULL
);
831 void __discard_continues(void)
835 stree
= pop_stree(&continue_stack
);
839 void __process_continues(void)
843 stree
= pop_stree(&continue_stack
);
845 stree
= clone_stree(cur_stree
);
847 merge_stree(&stree
, cur_stree
);
849 push_stree(&continue_stack
, stree
);
852 void __merge_continues(void)
856 stree
= pop_stree(&continue_stack
);
857 merge_stree(&cur_stree
, stree
);
861 void __push_breaks(void)
863 push_stree(&break_stack
, NULL
);
866 void __process_breaks(void)
870 stree
= pop_stree(&break_stack
);
872 stree
= clone_stree(cur_stree
);
874 merge_stree(&stree
, cur_stree
);
876 push_stree(&break_stack
, stree
);
879 int __has_breaks(void)
884 stree
= pop_stree(&break_stack
);
886 push_stree(&break_stack
, stree
);
890 void __merge_breaks(void)
894 stree
= pop_stree(&break_stack
);
895 merge_stree(&cur_stree
, stree
);
899 void __use_breaks(void)
901 free_stree(&cur_stree
);
902 cur_stree
= pop_stree(&break_stack
);
905 void __save_switch_states(struct expression
*switch_expr
)
907 push_rl(&remaining_cases
, __get_implied_values(switch_expr
));
908 push_stree(&switch_stack
, clone_stree(cur_stree
));
911 void __merge_switches(struct expression
*switch_expr
, struct expression
*case_expr
, struct expression
*case_to
)
914 struct stree
*implied_stree
;
916 stree
= pop_stree(&switch_stack
);
917 implied_stree
= __implied_case_stree(switch_expr
, case_expr
, case_to
, &remaining_cases
, &stree
);
918 merge_stree(&cur_stree
, implied_stree
);
919 free_stree(&implied_stree
);
920 push_stree(&switch_stack
, stree
);
923 void __discard_switches(void)
927 pop_rl(&remaining_cases
);
928 stree
= pop_stree(&switch_stack
);
932 void __push_default(void)
934 push_stree(&default_stack
, NULL
);
937 void __set_default(void)
939 set_state_stree_stack(&default_stack
, 0, "has_default", NULL
, &true_state
);
942 int __pop_default(void)
946 stree
= pop_stree(&default_stack
);
954 static struct named_stree
*alloc_named_stree(const char *name
, struct stree
*stree
)
956 struct named_stree
*named_stree
= __alloc_named_stree(0);
958 named_stree
->name
= (char *)name
;
959 named_stree
->stree
= stree
;
963 void __save_gotos(const char *name
)
965 struct stree
**stree
;
968 stree
= get_named_stree(goto_stack
, name
);
970 merge_stree(stree
, cur_stree
);
973 struct named_stree
*named_stree
;
975 clone
= clone_stree(cur_stree
);
976 named_stree
= alloc_named_stree(name
, clone
);
977 add_ptr_list(&goto_stack
, named_stree
);
981 void __merge_gotos(const char *name
)
983 struct stree
**stree
;
985 stree
= get_named_stree(goto_stack
, name
);
987 merge_stree(&cur_stree
, *stree
);