2 * Copyright (C) 2008 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 * Imagine we have this code:
26 * if (foo == 99) // <-- point #2
27 * bar->baz; // <-- point #3
30 * At point #3 bar is non null and can be dereferenced.
32 * It's smatch_implied.c which sets bar to non null at point #2.
34 * At point #1 merge_slist() stores the list of states from both
35 * the true and false paths. On the true path foo == 99 and on
36 * the false path foo == 1. merge_slist() sets their pool
37 * list to show the other states which were there when foo == 99.
39 * When it comes to the if (foo == 99) the smatch implied hook
40 * looks for all the pools where foo was not 99. It makes a list
43 * Then for bar (and all the other states) it says, ok bar is a
44 * merged state that came from these previous states. We'll
45 * chop out all the states where it came from a pool where
46 * foo != 99 and merge it all back together.
48 * That is the implied state of bar.
50 * merge_slist() sets up ->pool. An sm_state only has one ->pool and
51 * that is the pool where it was first set. The my pool gets set when
52 * code paths merge. States that have been set since the last merge do
54 * merge_sm_state() sets ->left and ->right. (These are the states which were
55 * merged to form the current state.)
56 * a pool: a pool is an slist that has been merged with another slist.
62 #include "smatch_slist.h"
63 #include "smatch_extra.h"
65 char *implied_debug_msg
;
66 #define DIMPLIED(msg...) do { if (option_debug_implied || option_debug) printf(msg); } while (0)
68 int option_debug_implied
= 0;
72 * It messes things up to free range list allocations. This helper fuction
73 * lets us reuse memory instead of doing new allocations.
75 static struct range_list
*tmp_range_list(struct symbol
*type
, long long num
)
77 static struct range_list
*my_list
= NULL
;
78 static struct data_range
*my_range
;
80 __free_ptr_list((struct ptr_list
**)&my_list
);
81 my_range
= alloc_range(ll_to_sval(num
), ll_to_sval(num
));
82 add_ptr_list(&my_list
, my_range
);
86 static void print_debug_tf(struct sm_state
*sm
, int istrue
, int isfalse
)
88 if (!option_debug_implied
&& !option_debug
)
91 if (istrue
&& isfalse
) {
92 printf("%s: %d: does not exist.\n", show_sm(sm
), sm
->line
);
94 printf("'%s = %s' from %d is true. %s[stree %d]\n", sm
->name
, show_state(sm
->state
),
95 sm
->line
, sm
->merged
? "[merged]" : "[leaf]",
96 get_stree_id(sm
->pool
));
98 printf("'%s = %s' from %d is false. %s[stree %d]\n", sm
->name
, show_state(sm
->state
),
100 sm
->merged
? "[merged]" : "[leaf]",
101 get_stree_id(sm
->pool
));
103 printf("'%s = %s' from %d could be true or false. %s[stree %d]\n", sm
->name
,
104 show_state(sm
->state
), sm
->line
,
105 sm
->merged
? "[merged]" : "[leaf]",
106 get_stree_id(sm
->pool
));
110 static int create_fake_history(struct sm_state
*sm
, int comparison
, struct range_list
*rl
)
112 struct range_list
*orig_rl
;
113 struct range_list
*true_rl
, *false_rl
;
114 struct stree
*true_stree
, *false_stree
;
115 struct sm_state
*true_sm
, *false_sm
;
118 if (is_merged(sm
) || sm
->left
|| sm
->right
)
120 if (!rl_to_sval(rl
, &sval
))
122 if (!estate_rl(sm
->state
))
125 orig_rl
= cast_rl(rl_type(rl
), estate_rl(sm
->state
));
126 split_comparison_rl(orig_rl
, comparison
, rl
, &true_rl
, &false_rl
, NULL
, NULL
);
128 true_rl
= rl_truncate_cast(estate_type(sm
->state
), true_rl
);
129 false_rl
= rl_truncate_cast(estate_type(sm
->state
), false_rl
);
130 if (is_whole_rl(true_rl
) || is_whole_rl(false_rl
) ||
131 !true_rl
|| !false_rl
||
132 rl_equiv(orig_rl
, true_rl
) || rl_equiv(orig_rl
, false_rl
) ||
133 rl_equiv(estate_rl(sm
->state
), true_rl
) || rl_equiv(estate_rl(sm
->state
), false_rl
))
136 if (rl_intersection(true_rl
, false_rl
)) {
137 sm_msg("internal error parsing (%s (%s) %s %s)",
138 sm
->name
, sm
->state
->name
, show_special(comparison
), show_rl(rl
));
139 sm_msg("true_rl = %s false_rl = %s intersection = %s",
140 show_rl(true_rl
), show_rl(false_rl
), show_rl(rl_intersection(true_rl
, false_rl
)));
145 sm_msg("fake_history: %s vs %s. %s %s %s. --> T: %s F: %s",
146 sm
->name
, show_rl(rl
), sm
->state
->name
, show_special(comparison
), show_rl(rl
),
147 show_rl(true_rl
), show_rl(false_rl
));
149 true_sm
= clone_sm(sm
);
150 false_sm
= clone_sm(sm
);
152 true_sm
->state
= alloc_estate_rl(cast_rl(estate_type(sm
->state
), true_rl
));
153 free_slist(&true_sm
->possible
);
154 add_possible_sm(true_sm
, true_sm
);
155 false_sm
->state
= alloc_estate_rl(cast_rl(estate_type(sm
->state
), false_rl
));
156 free_slist(&false_sm
->possible
);
157 add_possible_sm(false_sm
, false_sm
);
159 true_stree
= clone_stree(sm
->pool
);
160 false_stree
= clone_stree(sm
->pool
);
162 overwrite_sm_state_stree(&true_stree
, true_sm
);
163 overwrite_sm_state_stree(&false_stree
, false_sm
);
165 true_sm
->pool
= true_stree
;
166 false_sm
->pool
= false_stree
;
170 sm
->right
= false_sm
;
176 * add_pool() adds a slist to *pools. If the slist has already been
177 * added earlier then it doesn't get added a second time.
179 void add_pool(struct state_list
**pools
, struct sm_state
*new)
181 struct sm_state
*tmp
;
183 FOR_EACH_PTR(*pools
, tmp
) {
184 if (tmp
->pool
< new->pool
)
186 else if (tmp
->pool
== new->pool
) {
189 INSERT_CURRENT(new, tmp
);
192 } END_FOR_EACH_PTR(tmp
);
193 add_ptr_list(pools
, new);
196 static int pool_in_pools(struct stree
*pool
,
197 const struct state_list
*slist
)
199 struct sm_state
*tmp
;
201 FOR_EACH_PTR(slist
, tmp
) {
204 if (tmp
->pool
== pool
)
206 } END_FOR_EACH_PTR(tmp
);
210 static int remove_pool(struct state_list
**pools
, struct stree
*remove
)
212 struct sm_state
*tmp
;
215 FOR_EACH_PTR(*pools
, tmp
) {
216 if (tmp
->pool
== remove
) {
217 DELETE_CURRENT_PTR(tmp
);
220 } END_FOR_EACH_PTR(tmp
);
226 * If 'foo' == 99 add it that pool to the true pools. If it's false, add it to
227 * the false pools. If we're not sure, then we don't add it to either.
229 static void do_compare(struct sm_state
*sm
, int comparison
, struct range_list
*rl
,
230 struct state_list
**true_stack
,
231 struct state_list
**maybe_stack
,
232 struct state_list
**false_stack
,
233 int *mixed
, struct sm_state
*gate_sm
)
237 struct range_list
*var_rl
;
242 var_rl
= cast_rl(rl_type(rl
), estate_rl(sm
->state
));
244 istrue
= !possibly_false_rl(var_rl
, comparison
, rl
);
245 isfalse
= !possibly_true_rl(var_rl
, comparison
, rl
);
247 print_debug_tf(sm
, istrue
, isfalse
);
249 /* give up if we have borrowed implications (smatch_equiv.c) */
250 if (sm
->sym
!= gate_sm
->sym
||
251 strcmp(sm
->name
, gate_sm
->name
) != 0) {
256 if (mixed
&& !*mixed
&& !is_merged(sm
) && !istrue
&& !isfalse
) {
257 if (!create_fake_history(sm
, comparison
, rl
)) {
264 add_pool(true_stack
, sm
);
266 add_pool(false_stack
, sm
);
268 add_pool(maybe_stack
, sm
);
272 static int is_checked(struct state_list
*checked
, struct sm_state
*sm
)
274 struct sm_state
*tmp
;
276 FOR_EACH_PTR(checked
, tmp
) {
279 } END_FOR_EACH_PTR(tmp
);
285 * Example code: if (foo == 99) {
287 * Say 'foo' is a merged state that has many possible values. It is the combination
288 * of merges. separate_pools() iterates through the pools recursively and calls
289 * do_compare() for each time 'foo' was set.
291 static void __separate_pools(struct sm_state
*sm
, int comparison
, struct range_list
*rl
,
292 struct state_list
**true_stack
,
293 struct state_list
**maybe_stack
,
294 struct state_list
**false_stack
,
295 struct state_list
**checked
, int *mixed
, struct sm_state
*gate_sm
)
297 int free_checked
= 0;
298 struct state_list
*checked_states
= NULL
;
304 * If it looks like this is going to take too long as-is, then don't
305 * create even more fake history.
307 if (mixed
&& sm
->nr_children
> 100)
311 Sometimes the implications are just too big to deal with
312 so we bail. Theoretically, bailing out here can cause more false
313 positives but won't hide actual bugs.
315 if (sm
->nr_children
> 4000) {
316 if (option_debug
|| option_debug_implied
) {
317 static char buf
[1028];
318 snprintf(buf
, sizeof(buf
), "debug: %s: nr_children over 4000 (%d). (%s %s)",
319 __func__
, sm
->nr_children
, sm
->name
, show_state(sm
->state
));
320 implied_debug_msg
= buf
;
325 if (checked
== NULL
) {
326 checked
= &checked_states
;
329 if (is_checked(*checked
, sm
))
331 add_ptr_list(checked
, sm
);
333 do_compare(sm
, comparison
, rl
, true_stack
, maybe_stack
, false_stack
, mixed
, gate_sm
);
335 __separate_pools(sm
->left
, comparison
, rl
, true_stack
, maybe_stack
, false_stack
, checked
, mixed
, gate_sm
);
336 __separate_pools(sm
->right
, comparison
, rl
, true_stack
, maybe_stack
, false_stack
, checked
, mixed
, gate_sm
);
341 static void separate_pools(struct sm_state
*sm
, int comparison
, struct range_list
*rl
,
342 struct state_list
**true_stack
,
343 struct state_list
**false_stack
,
344 struct state_list
**checked
, int *mixed
)
346 struct state_list
*maybe_stack
= NULL
;
347 struct sm_state
*tmp
;
349 __separate_pools(sm
, comparison
, rl
, true_stack
, &maybe_stack
, false_stack
, checked
, mixed
, sm
);
354 FOR_EACH_PTR(*true_stack
, sm
) {
355 sm_msg("TRUE %s [stree %d]", show_sm(sm
), get_stree_id(sm
->pool
));
356 } END_FOR_EACH_PTR(sm
);
358 FOR_EACH_PTR(maybe_stack
, sm
) {
359 sm_msg("MAYBE %s [stree %d]", show_sm(sm
), get_stree_id(sm
->pool
));
360 } END_FOR_EACH_PTR(sm
);
362 FOR_EACH_PTR(*false_stack
, sm
) {
363 sm_msg("FALSE %s [stree %d]", show_sm(sm
), get_stree_id(sm
->pool
));
364 } END_FOR_EACH_PTR(sm
);
366 /* if it's a maybe then remove it from the false stack */
367 FOR_EACH_PTR(maybe_stack
, tmp
) {
368 remove_pool(false_stack
, tmp
->pool
);
369 } END_FOR_EACH_PTR(tmp
);
371 /* and the true stack */
372 FOR_EACH_PTR(maybe_stack
, tmp
) {
373 remove_pool(true_stack
, tmp
->pool
);
374 } END_FOR_EACH_PTR(tmp
);
376 /* if it's both true and false remove it from both */
377 FOR_EACH_PTR(*true_stack
, tmp
) {
378 if (remove_pool(false_stack
, tmp
->pool
))
379 DELETE_CURRENT_PTR(tmp
);
380 } END_FOR_EACH_PTR(tmp
);
383 static int sm_in_keep_leafs(struct sm_state
*sm
, const struct state_list
*keep_gates
)
385 struct sm_state
*tmp
, *old
;
387 FOR_EACH_PTR(keep_gates
, tmp
) {
390 old
= get_sm_state_stree(tmp
->pool
, sm
->owner
, sm
->name
, sm
->sym
);
395 } END_FOR_EACH_PTR(tmp
);
400 * NOTE: If a state is in both the keep stack and the remove stack then it is
401 * removed. If that happens it means you have a bug. Only add states which are
402 * definitely true or definitely false. If you have a leaf state that could be
403 * both true and false, then create a fake split history where one side is true
404 * and one side is false. Otherwise, if you can't do that, then don't add it to
405 * either list, and it will be treated as true.
407 struct sm_state
*filter_pools(struct sm_state
*sm
,
408 const struct state_list
*remove_stack
,
409 const struct state_list
*keep_stack
,
412 struct sm_state
*ret
= NULL
;
413 struct sm_state
*left
;
414 struct sm_state
*right
;
420 if (sm
->nr_children
> 4000) {
421 if (option_debug
|| option_debug_implied
) {
422 static char buf
[1028];
423 snprintf(buf
, sizeof(buf
), "debug: %s: nr_children over 4000 (%d). (%s %s)",
424 __func__
, sm
->nr_children
, sm
->name
, show_state(sm
->state
));
425 implied_debug_msg
= buf
;
430 if (pool_in_pools(sm
->pool
, remove_stack
)) {
431 DIMPLIED("removed [stree %d] %s from %d\n", get_stree_id(sm
->pool
), show_sm(sm
), sm
->line
);
436 if (!is_merged(sm
) || pool_in_pools(sm
->pool
, keep_stack
) || sm_in_keep_leafs(sm
, keep_stack
)) {
437 DIMPLIED("kept [stree %d] %s from %d\n", get_stree_id(sm
->pool
), show_sm(sm
), sm
->line
);
441 DIMPLIED("checking [stree %d] %s from %d (%d) left = %s [stree %d] right = %s [stree %d]\n",
442 get_stree_id(sm
->pool
),
443 show_sm(sm
), sm
->line
, sm
->nr_children
,
444 sm
->left
? sm
->left
->state
->name
: "<none>", sm
->left
? get_stree_id(sm
->left
->pool
) : -1,
445 sm
->right
? sm
->right
->state
->name
: "<none>", sm
->right
? get_stree_id(sm
->right
->pool
) : -1);
446 left
= filter_pools(sm
->left
, remove_stack
, keep_stack
, &removed
);
447 right
= filter_pools(sm
->right
, remove_stack
, keep_stack
, &removed
);
449 DIMPLIED("kept [stree %d] %s from %d\n", get_stree_id(sm
->pool
), show_sm(sm
), sm
->line
);
453 if (!left
&& !right
) {
454 DIMPLIED("removed [stree %d] %s from %d <none>\n", get_stree_id(sm
->pool
), show_sm(sm
), sm
->line
);
459 ret
= clone_sm(right
);
464 ret
= clone_sm(left
);
469 ret
= merge_sm_states(left
, right
);
472 ret
->pool
= sm
->pool
;
475 DIMPLIED("partial %s => ", show_sm(sm
));
476 DIMPLIED("%s from %d [stree %d]\n", show_sm(ret
), sm
->line
, get_stree_id(sm
->pool
));
480 static struct stree
*filter_stack(struct sm_state
*gate_sm
,
481 struct stree
*pre_stree
,
482 const struct state_list
*remove_stack
,
483 const struct state_list
*keep_stack
)
485 struct stree
*ret
= NULL
;
486 struct sm_state
*tmp
;
487 struct sm_state
*filtered_sm
;
493 FOR_EACH_SM(pre_stree
, tmp
) {
495 sm_msg("%s: %s", __func__
, show_sm(tmp
));
498 if (sm_in_keep_leafs(tmp
, keep_stack
))
501 filtered_sm
= filter_pools(tmp
, remove_stack
, keep_stack
, &modified
);
502 if (!filtered_sm
|| !modified
)
504 /* the assignments here are for borrowed implications */
505 filtered_sm
->name
= tmp
->name
;
506 filtered_sm
->sym
= tmp
->sym
;
507 avl_insert(&ret
, filtered_sm
);
511 } END_FOR_EACH_SM(tmp
);
515 static void separate_and_filter(struct sm_state
*sm
, int comparison
, struct range_list
*rl
,
516 struct stree
*pre_stree
,
517 struct stree
**true_states
,
518 struct stree
**false_states
,
521 struct state_list
*true_stack
= NULL
;
522 struct state_list
*false_stack
= NULL
;
523 struct timeval time_before
;
524 struct timeval time_after
;
526 gettimeofday(&time_before
, NULL
);
528 if (!is_merged(sm
)) {
529 DIMPLIED("%d '%s' is not merged.\n", get_lineno(), sm
->name
);
533 if (option_debug_implied
|| option_debug
) {
534 sm_msg("checking implications: (%s %s %s)",
535 sm
->name
, show_special(comparison
), show_rl(rl
));
538 separate_pools(sm
, comparison
, rl
, &true_stack
, &false_stack
, NULL
, mixed
);
540 DIMPLIED("filtering true stack.\n");
541 *true_states
= filter_stack(sm
, pre_stree
, false_stack
, true_stack
);
542 DIMPLIED("filtering false stack.\n");
543 *false_states
= filter_stack(sm
, pre_stree
, true_stack
, false_stack
);
544 free_slist(&true_stack
);
545 free_slist(&false_stack
);
546 if (option_debug_implied
|| option_debug
) {
547 printf("These are the implied states for the true path:\n");
548 __print_stree(*true_states
);
549 printf("These are the implied states for the false path:\n");
550 __print_stree(*false_states
);
553 gettimeofday(&time_after
, NULL
);
554 if (time_after
.tv_sec
- time_before
.tv_sec
> 20) {
555 sm
->nr_children
= 4000;
556 sm_msg("Function too hairy. Giving up.");
560 static struct expression
*get_last_expr(struct statement
*stmt
)
562 struct statement
*last
;
564 last
= last_ptr_list((struct ptr_list
*)stmt
->stmts
);
565 if (last
->type
== STMT_EXPRESSION
)
566 return last
->expression
;
568 if (last
->type
== STMT_LABEL
) {
569 if (last
->label_statement
&&
570 last
->label_statement
->type
== STMT_EXPRESSION
)
571 return last
->label_statement
->expression
;
577 static struct expression
*get_left_most_expr(struct expression
*expr
)
579 struct statement
*compound
;
581 compound
= get_expression_statement(expr
);
583 return get_last_expr(compound
);
585 expr
= strip_parens(expr
);
586 if (expr
->type
== EXPR_ASSIGNMENT
)
587 return get_left_most_expr(expr
->left
);
591 static int is_merged_expr(struct expression
*expr
)
596 if (get_value(expr
, &dummy
))
598 sm
= get_sm_state_expr(SMATCH_EXTRA
, expr
);
606 static void delete_gate_sm_equiv(struct stree
**stree
, const char *name
, struct symbol
*sym
)
608 struct smatch_state
*state
;
609 struct relation
*rel
;
611 state
= get_state(SMATCH_EXTRA
, name
, sym
);
614 FOR_EACH_PTR(estate_related(state
), rel
) {
615 delete_state_stree(stree
, SMATCH_EXTRA
, rel
->name
, rel
->sym
);
616 } END_FOR_EACH_PTR(rel
);
619 static void delete_gate_sm(struct stree
**stree
, const char *name
, struct symbol
*sym
)
621 delete_state_stree(stree
, SMATCH_EXTRA
, name
, sym
);
624 static int handle_comparison(struct expression
*expr
,
625 struct stree
**implied_true
,
626 struct stree
**implied_false
)
628 struct sm_state
*sm
= NULL
;
629 struct range_list
*rl
= NULL
;
630 struct expression
*left
;
631 struct expression
*right
;
633 int comparison
= expr
->op
;
636 left
= get_left_most_expr(expr
->left
);
637 right
= get_left_most_expr(expr
->right
);
639 if (is_merged_expr(left
)) {
640 sm
= get_sm_state_expr(SMATCH_EXTRA
, left
);
641 get_implied_rl(right
, &rl
);
642 } else if (is_merged_expr(right
)) {
643 sm
= get_sm_state_expr(SMATCH_EXTRA
, right
);
644 get_implied_rl(left
, &rl
);
645 comparison
= flip_comparison(comparison
);
653 type
= get_type(expr
);
656 if (type_positive_bits(rl_type(rl
)) > type_positive_bits(type
))
658 if (type_positive_bits(type
) < 31)
660 rl
= cast_rl(type
, rl
);
662 separate_and_filter(sm
, comparison
, rl
, __get_cur_stree(), implied_true
, implied_false
, &mixed
);
665 delete_gate_sm_equiv(implied_true
, sm
->name
, sm
->sym
);
666 delete_gate_sm_equiv(implied_false
, sm
->name
, sm
->sym
);
668 delete_gate_sm(implied_true
, sm
->name
, sm
->sym
);
669 delete_gate_sm(implied_false
, sm
->name
, sm
->sym
);
675 static int handle_zero_comparison(struct expression
*expr
,
676 struct stree
**implied_true
,
677 struct stree
**implied_false
)
685 if (expr
->type
== EXPR_POSTOP
)
686 expr
= strip_expr(expr
->unop
);
688 if (expr
->type
== EXPR_ASSIGNMENT
) {
689 /* most of the time ->pools will be empty here because we
690 just set the state, but if have assigned a conditional
691 function there are implications. */
695 name
= expr_to_var_sym(expr
, &sym
);
698 sm
= get_sm_state(SMATCH_EXTRA
, name
, sym
);
702 separate_and_filter(sm
, SPECIAL_NOTEQUAL
, tmp_range_list(estate_type(sm
->state
), 0), __get_cur_stree(), implied_true
, implied_false
, &mixed
);
703 delete_gate_sm_equiv(implied_true
, sm
->name
, sm
->sym
);
704 delete_gate_sm_equiv(implied_false
, sm
->name
, sm
->sym
);
706 delete_gate_sm(implied_true
, sm
->name
, sm
->sym
);
707 delete_gate_sm(implied_false
, sm
->name
, sm
->sym
);
716 static int handled_by_implied_hook(struct expression
*expr
,
717 struct stree
**implied_true
,
718 struct stree
**implied_false
)
720 struct state_list
*true_stack
= NULL
;
721 struct state_list
*false_stack
= NULL
;
722 struct stree
*pre_stree
;
725 sm
= comparison_implication_hook(expr
, &true_stack
, &false_stack
);
729 pre_stree
= clone_stree(__get_cur_stree());
731 *implied_true
= filter_stack(sm
, pre_stree
, false_stack
, true_stack
);
732 *implied_false
= filter_stack(sm
, pre_stree
, true_stack
, false_stack
);
734 free_stree(&pre_stree
);
735 free_slist(&true_stack
);
736 free_slist(&false_stack
);
741 static int handled_by_extra_states(struct expression
*expr
,
742 struct stree
**implied_true
,
743 struct stree
**implied_false
)
745 if (expr
->type
== EXPR_COMPARE
)
746 return handle_comparison(expr
, implied_true
, implied_false
);
748 return handle_zero_comparison(expr
, implied_true
, implied_false
);
751 static int handled_by_stored_conditions(struct expression
*expr
,
752 struct stree
**implied_true
,
753 struct stree
**implied_false
)
755 struct state_list
*true_stack
= NULL
;
756 struct state_list
*false_stack
= NULL
;
757 struct stree
*pre_stree
;
760 sm
= stored_condition_implication_hook(expr
, &true_stack
, &false_stack
);
764 pre_stree
= clone_stree(__get_cur_stree());
766 *implied_true
= filter_stack(sm
, pre_stree
, false_stack
, true_stack
);
767 *implied_false
= filter_stack(sm
, pre_stree
, true_stack
, false_stack
);
769 free_stree(&pre_stree
);
770 free_slist(&true_stack
);
771 free_slist(&false_stack
);
776 static int found_implications
;
777 static struct stree
*saved_implied_true
;
778 static struct stree
*saved_implied_false
;
779 static struct stree
*extra_saved_implied_true
;
780 static struct stree
*extra_saved_implied_false
;
782 static void get_tf_states(struct expression
*expr
,
783 struct stree
**implied_true
,
784 struct stree
**implied_false
)
786 if (handled_by_implied_hook(expr
, implied_true
, implied_false
))
789 if (handled_by_extra_states(expr
, implied_true
, implied_false
)) {
790 /* We process these later. */
791 extra_saved_implied_true
= *implied_true
;
792 extra_saved_implied_false
= *implied_false
;
793 *implied_true
= NULL
;
794 *implied_false
= NULL
;
798 if (handled_by_stored_conditions(expr
, implied_true
, implied_false
))
803 found_implications
= 1;
806 static void save_implications_hook(struct expression
*expr
)
808 get_tf_states(expr
, &saved_implied_true
, &saved_implied_false
);
811 static void set_implied_states(struct expression
*expr
)
815 FOR_EACH_SM(saved_implied_true
, sm
) {
816 __set_true_false_sm(sm
, NULL
);
817 } END_FOR_EACH_SM(sm
);
818 free_stree(&saved_implied_true
);
820 FOR_EACH_SM(saved_implied_false
, sm
) {
821 __set_true_false_sm(NULL
, sm
);
822 } END_FOR_EACH_SM(sm
);
823 free_stree(&saved_implied_false
);
826 static void set_extra_implied_states(struct expression
*expr
)
828 saved_implied_true
= extra_saved_implied_true
;
829 saved_implied_false
= extra_saved_implied_false
;
830 extra_saved_implied_true
= NULL
;
831 extra_saved_implied_false
= NULL
;
832 set_implied_states(NULL
);
835 void param_limit_implications(struct expression
*expr
, int param
, char *key
, char *value
)
837 struct expression
*arg
;
838 struct symbol
*compare_type
;
842 struct sm_state
*tmp
;
843 struct stree
*implied_true
= NULL
;
844 struct stree
*implied_false
= NULL
;
845 struct range_list
*orig
, *limit
, *rl
;
847 while (expr
->type
== EXPR_ASSIGNMENT
)
848 expr
= strip_expr(expr
->right
);
849 if (expr
->type
!= EXPR_CALL
)
852 arg
= get_argument_from_call_expr(expr
->args
, param
);
856 name
= get_variable_from_key(arg
, key
, &sym
);
860 sm
= get_sm_state(SMATCH_EXTRA
, name
, sym
);
861 if (!sm
|| !sm
->merged
)
864 if (strcmp(key
, "$") == 0)
865 compare_type
= get_arg_type(expr
->fn
, param
);
867 compare_type
= get_member_type_from_key(arg
, key
);
869 orig
= estate_rl(sm
->state
);
870 orig
= cast_rl(compare_type
, orig
);
872 call_results_to_rl(expr
, compare_type
, value
, &limit
);
873 rl
= rl_intersection(orig
, limit
);
875 separate_and_filter(sm
, SPECIAL_EQUAL
, rl
, __get_cur_stree(), &implied_true
, &implied_false
, NULL
);
877 FOR_EACH_SM(implied_true
, tmp
) {
878 __set_sm_fake_stree(tmp
);
879 } END_FOR_EACH_SM(tmp
);
881 free_stree(&implied_true
);
882 free_stree(&implied_false
);
887 struct stree
*__implied_case_stree(struct expression
*switch_expr
,
888 struct range_list
*rl
,
889 struct range_list_stack
**remaining_cases
,
890 struct stree
**raw_stree
)
894 struct var_sym_list
*vsl
;
896 struct stree
*true_states
= NULL
;
897 struct stree
*false_states
= NULL
;
898 struct stree
*extra_states
;
899 struct stree
*ret
= clone_stree(*raw_stree
);
901 name
= expr_to_chunk_sym_vsl(switch_expr
, &sym
, &vsl
);
906 filter_top_rl(remaining_cases
, rl
);
908 rl
= clone_rl(top_rl(*remaining_cases
));
910 sm
= get_sm_state_stree(*raw_stree
, SMATCH_EXTRA
, name
, sym
);
912 separate_and_filter(sm
, SPECIAL_EQUAL
, rl
, *raw_stree
, &true_states
, &false_states
, NULL
);
914 __push_fake_cur_stree();
916 set_extra_nomod_vsl(name
, sym
, vsl
, alloc_estate_rl(rl
));
917 __pass_case_to_client(switch_expr
, rl
);
918 extra_states
= __pop_fake_cur_stree();
919 overwrite_stree(extra_states
, &true_states
);
920 overwrite_stree(true_states
, &ret
);
921 free_stree(&extra_states
);
922 free_stree(&true_states
);
923 free_stree(&false_states
);
929 static void match_end_func(struct symbol
*sym
)
933 implied_debug_msg
= NULL
;
936 static void get_tf_stacks_from_pool(struct sm_state
*gate_sm
,
937 struct sm_state
*pool_sm
,
938 struct state_list
**true_stack
,
939 struct state_list
**false_stack
)
941 struct sm_state
*tmp
;
942 int possibly_true
= 0;
947 if (strcmp(gate_sm
->state
->name
, pool_sm
->state
->name
) == 0) {
948 add_ptr_list(true_stack
, pool_sm
);
952 FOR_EACH_PTR(gate_sm
->possible
, tmp
) {
953 if (strcmp(tmp
->state
->name
, pool_sm
->state
->name
) == 0) {
957 } END_FOR_EACH_PTR(tmp
);
959 if (!possibly_true
) {
960 add_ptr_list(false_stack
, gate_sm
);
964 get_tf_stacks_from_pool(gate_sm
->left
, pool_sm
, true_stack
, false_stack
);
965 get_tf_stacks_from_pool(gate_sm
->right
, pool_sm
, true_stack
, false_stack
);
969 * The situation is we have a SMATCH_EXTRA state and we want to break it into
970 * each of the ->possible states and find the implications of each. The caller
971 * has to use __push_fake_cur_stree() to preserve the correct states so they
972 * can be restored later.
974 void overwrite_states_using_pool(struct sm_state
*gate_sm
, struct sm_state
*pool_sm
)
976 struct state_list
*true_stack
= NULL
;
977 struct state_list
*false_stack
= NULL
;
978 struct stree
*pre_stree
;
979 struct stree
*implied_true
;
980 struct sm_state
*tmp
;
985 get_tf_stacks_from_pool(gate_sm
, pool_sm
, &true_stack
, &false_stack
);
987 pre_stree
= clone_stree(__get_cur_stree());
989 implied_true
= filter_stack(gate_sm
, pre_stree
, false_stack
, true_stack
);
991 free_stree(&pre_stree
);
992 free_slist(&true_stack
);
993 free_slist(&false_stack
);
995 FOR_EACH_SM(implied_true
, tmp
) {
996 set_state(tmp
->owner
, tmp
->name
, tmp
->sym
, tmp
->state
);
997 } END_FOR_EACH_SM(tmp
);
999 free_stree(&implied_true
);
1002 int assume(struct expression
*expr
)
1004 int orig_final_pass
= final_pass
;
1007 __push_fake_cur_stree();
1008 found_implications
= 0;
1009 __split_whole_condition(expr
);
1010 final_pass
= orig_final_pass
;
1012 if (!found_implications
) {
1013 __discard_false_states();
1014 __free_fake_cur_stree();
1021 void end_assume(void)
1023 __discard_false_states();
1024 __free_fake_cur_stree();
1027 void __extra_match_condition(struct expression
*expr
);
1028 void __comparison_match_condition(struct expression
*expr
);
1029 void __stored_condition(struct expression
*expr
);
1030 void register_implications(int id
)
1032 add_hook(&save_implications_hook
, CONDITION_HOOK
);
1033 add_hook(&set_implied_states
, CONDITION_HOOK
);
1034 add_hook(&__extra_match_condition
, CONDITION_HOOK
);
1035 add_hook(&set_extra_implied_states
, CONDITION_HOOK
);
1036 add_hook(&__comparison_match_condition
, CONDITION_HOOK
);
1037 add_hook(&__stored_condition
, CONDITION_HOOK
);
1038 add_hook(&match_end_func
, END_FUNC_HOOK
);