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 * smatch_extra.c is supposed to track the value of every variable.
31 #include "smatch_slist.h"
32 #include "smatch_extra.h"
37 static void match_link_modify(struct sm_state
*sm
, struct expression
*mod_expr
);
39 struct string_list
*__ignored_macros
= NULL
;
40 static int in_warn_on_macro(void)
42 struct statement
*stmt
;
46 stmt
= get_current_statement();
49 macro
= get_macro_name(stmt
->pos
);
53 FOR_EACH_PTR(__ignored_macros
, tmp
) {
54 if (!strcmp(tmp
, macro
))
56 } END_FOR_EACH_PTR(tmp
);
60 typedef void (mod_hook
)(const char *name
, struct symbol
*sym
, struct smatch_state
*state
);
61 DECLARE_PTR_LIST(void_fn_list
, mod_hook
*);
62 static struct void_fn_list
*extra_mod_hooks
;
63 void add_extra_mod_hook(mod_hook
*fn
)
65 mod_hook
**p
= malloc(sizeof(mod_hook
*));
67 add_ptr_list(&extra_mod_hooks
, p
);
70 void call_extra_mod_hooks(const char *name
, struct symbol
*sym
, struct smatch_state
*state
)
74 FOR_EACH_PTR(extra_mod_hooks
, fn
) {
75 (*fn
)(name
, sym
, state
);
76 } END_FOR_EACH_PTR(fn
);
79 struct sm_state
*set_extra_mod_helper(const char *name
, struct symbol
*sym
, struct smatch_state
*state
)
81 remove_from_equiv(name
, sym
);
82 call_extra_mod_hooks(name
, sym
, state
);
83 if (__in_fake_assign
&& estate_is_unknown(state
) && !get_state(SMATCH_EXTRA
, name
, sym
))
85 return set_state(SMATCH_EXTRA
, name
, sym
, state
);
88 static char *get_other_name_sym(const char *name
, struct symbol
*sym
, struct symbol
**new_sym
)
90 struct expression
*assigned
;
91 char *orig_name
= NULL
;
101 skip
= strlen(sym
->ident
->name
);
102 if (name
[skip
] != '-' || name
[skip
+ 1] != '>')
106 assigned
= get_assigned_expr_name_sym(sym
->ident
->name
, sym
);
109 if (assigned
->type
== EXPR_PREOP
|| assigned
->op
== '&') {
111 orig_name
= expr_to_var_sym(assigned
, new_sym
);
112 if (!orig_name
|| !*new_sym
)
115 snprintf(buf
, sizeof(buf
), "%s.%s", orig_name
+ 1, name
+ skip
);
116 ret
= alloc_string(buf
);
117 free_string(orig_name
);
121 if (assigned
->type
!= EXPR_DEREF
)
124 orig_name
= expr_to_var_sym(assigned
, new_sym
);
125 if (!orig_name
|| !*new_sym
)
128 snprintf(buf
, sizeof(buf
), "%s->%s", orig_name
, name
+ skip
);
129 ret
= alloc_string(buf
);
130 free_string(orig_name
);
134 free_string(orig_name
);
138 struct sm_state
*set_extra_mod(const char *name
, struct symbol
*sym
, struct smatch_state
*state
)
141 struct symbol
*new_sym
;
144 sm
= set_extra_mod_helper(name
, sym
, state
);
145 new_name
= get_other_name_sym(name
, sym
, &new_sym
);
146 if (new_name
&& new_sym
)
147 set_extra_mod_helper(new_name
, new_sym
, state
);
148 free_string(new_name
);
152 static void clear_array_states(struct expression
*array
)
156 sm
= get_sm_state_expr(link_id
, array
);
158 match_link_modify(sm
, NULL
);
161 static struct sm_state
*set_extra_array_mod(struct expression
*expr
, struct smatch_state
*state
)
163 struct expression
*array
;
164 struct expression
*offset
;
165 struct var_sym_list
*vsl
;
170 struct sm_state
*ret
= NULL
;
172 array
= get_array_base(expr
);
173 offset
= get_array_offset(expr
);
175 name
= expr_to_chunk_sym_vsl(expr
, &sym
, &vsl
);
177 if (!name
|| !vsl
|| !get_value(offset
, &sval
)) {
178 clear_array_states(array
);
182 FOR_EACH_PTR(vsl
, vs
) {
183 store_link(link_id
, vs
->var
, vs
->sym
, name
, sym
);
184 } END_FOR_EACH_PTR(vs
);
186 ret
= set_state(SMATCH_EXTRA
, name
, sym
, state
);
192 struct sm_state
*set_extra_expr_mod(struct expression
*expr
, struct smatch_state
*state
)
196 struct sm_state
*ret
= NULL
;
199 return set_extra_array_mod(expr
, state
);
201 expr
= strip_expr(expr
);
202 name
= expr_to_var_sym(expr
, &sym
);
205 ret
= set_extra_mod(name
, sym
, state
);
211 void set_extra_nomod(const char *name
, struct symbol
*sym
, struct smatch_state
*state
)
214 struct symbol
*new_sym
;
215 struct relation
*rel
;
216 struct smatch_state
*orig_state
;
218 orig_state
= get_state(SMATCH_EXTRA
, name
, sym
);
220 new_name
= get_other_name_sym(name
, sym
, &new_sym
);
221 if (new_name
&& new_sym
)
222 set_state(SMATCH_EXTRA
, new_name
, new_sym
, state
);
223 free_string(new_name
);
225 if (!estate_related(orig_state
)) {
226 set_state(SMATCH_EXTRA
, name
, sym
, state
);
230 set_related(state
, estate_related(orig_state
));
231 FOR_EACH_PTR(estate_related(orig_state
), rel
) {
232 struct smatch_state
*estate
;
234 if (option_debug_related
)
235 sm_msg("%s updating related %s to %s", name
, rel
->name
, state
->name
);
236 estate
= get_state(SMATCH_EXTRA
, rel
->name
, rel
->sym
);
239 set_state(SMATCH_EXTRA
, rel
->name
, rel
->sym
, clone_estate_cast(estate_type(estate
), state
));
240 } END_FOR_EACH_PTR(rel
);
244 * This is for return_implies_state() hooks which modify a SMATCH_EXTRA state
246 void set_extra_expr_nomod(struct expression
*expr
, struct smatch_state
*state
)
251 name
= expr_to_var_sym(expr
, &sym
);
254 set_extra_nomod(name
, sym
, state
);
260 static void set_extra_true_false(const char *name
, struct symbol
*sym
,
261 struct smatch_state
*true_state
,
262 struct smatch_state
*false_state
)
265 struct symbol
*new_sym
;
266 struct relation
*rel
;
267 struct smatch_state
*orig_state
;
269 if (!true_state
&& !false_state
)
272 if (in_warn_on_macro())
275 new_name
= get_other_name_sym(name
, sym
, &new_sym
);
276 if (new_name
&& new_sym
)
277 set_true_false_states(SMATCH_EXTRA
, new_name
, new_sym
, true_state
, false_state
);
278 free_string(new_name
);
280 orig_state
= get_state(SMATCH_EXTRA
, name
, sym
);
282 if (!estate_related(orig_state
)) {
283 set_true_false_states(SMATCH_EXTRA
, name
, sym
, true_state
, false_state
);
288 set_related(true_state
, estate_related(orig_state
));
290 set_related(false_state
, estate_related(orig_state
));
292 FOR_EACH_PTR(estate_related(orig_state
), rel
) {
293 set_true_false_states(SMATCH_EXTRA
, rel
->name
, rel
->sym
,
294 true_state
, false_state
);
295 } END_FOR_EACH_PTR(rel
);
298 static void set_extra_chunk_true_false(struct expression
*expr
,
299 struct smatch_state
*true_state
,
300 struct smatch_state
*false_state
)
302 struct var_sym_list
*vsl
;
308 if (in_warn_on_macro())
311 type
= get_type(expr
);
315 name
= expr_to_chunk_sym_vsl(expr
, &sym
, &vsl
);
318 FOR_EACH_PTR(vsl
, vs
) {
319 store_link(link_id
, vs
->var
, vs
->sym
, name
, sym
);
320 } END_FOR_EACH_PTR(vs
);
322 set_true_false_states(SMATCH_EXTRA
, name
, sym
,
323 clone_estate(true_state
),
324 clone_estate(false_state
));
329 static void set_extra_expr_true_false(struct expression
*expr
,
330 struct smatch_state
*true_state
,
331 struct smatch_state
*false_state
)
337 if (!true_state
&& !false_state
)
340 if (get_value(expr
, &sval
))
343 expr
= strip_expr(expr
);
344 name
= expr_to_var_sym(expr
, &sym
);
347 set_extra_chunk_true_false(expr
, true_state
, false_state
);
350 set_extra_true_false(name
, sym
, true_state
, false_state
);
354 static struct sm_state
*handle_canonical_while_count_down(struct statement
*loop
)
356 struct expression
*iter_var
;
357 struct expression
*condition
;
359 struct smatch_state
*estate
;
362 condition
= strip_expr(loop
->iterator_pre_condition
);
365 if (condition
->type
!= EXPR_PREOP
&& condition
->type
!= EXPR_POSTOP
)
367 if (condition
->op
!= SPECIAL_DECREMENT
)
370 iter_var
= condition
->unop
;
371 sm
= get_sm_state_expr(SMATCH_EXTRA
, iter_var
);
374 if (sval_cmp_val(estate_min(sm
->state
), 0) < 0)
376 start
= estate_max(sm
->state
);
377 if (sval_cmp_val(start
, 0) <= 0)
379 if (!sval_is_max(start
))
382 if (condition
->type
== EXPR_PREOP
) {
383 estate
= alloc_estate_range(sval_type_val(start
.type
, 1), start
);
384 if (estate_has_hard_max(sm
->state
))
385 estate_set_hard_max(estate
);
386 estate_copy_fuzzy_max(estate
, sm
->state
);
387 set_extra_expr_mod(iter_var
, estate
);
389 if (condition
->type
== EXPR_POSTOP
) {
390 estate
= alloc_estate_range(sval_type_val(start
.type
, 0), start
);
391 if (estate_has_hard_max(sm
->state
))
392 estate_set_hard_max(estate
);
393 estate_copy_fuzzy_max(estate
, sm
->state
);
394 set_extra_expr_mod(iter_var
, estate
);
396 return get_sm_state_expr(SMATCH_EXTRA
, iter_var
);
399 static struct sm_state
*handle_canonical_for_inc(struct expression
*iter_expr
,
400 struct expression
*condition
)
402 struct expression
*iter_var
;
404 struct smatch_state
*estate
;
405 sval_t start
, end
, max
;
407 iter_var
= iter_expr
->unop
;
408 sm
= get_sm_state_expr(SMATCH_EXTRA
, iter_var
);
411 if (!estate_get_single_value(sm
->state
, &start
))
413 if (get_implied_max(condition
->right
, &end
))
414 end
= sval_cast(get_type(iter_var
), end
);
416 end
= sval_type_max(get_type(iter_var
));
418 if (get_sm_state_expr(SMATCH_EXTRA
, condition
->left
) != sm
)
421 switch (condition
->op
) {
422 case SPECIAL_UNSIGNED_LT
:
423 case SPECIAL_NOTEQUAL
:
425 if (!sval_is_min(end
))
428 case SPECIAL_UNSIGNED_LTE
:
434 if (sval_cmp(end
, start
) < 0)
436 estate
= alloc_estate_range(start
, end
);
437 if (get_hard_max(condition
->right
, &max
)) {
438 estate_set_hard_max(estate
);
439 if (condition
->op
== '<' ||
440 condition
->op
== SPECIAL_UNSIGNED_LT
||
441 condition
->op
== SPECIAL_NOTEQUAL
)
443 estate_set_fuzzy_max(estate
, max
);
445 set_extra_expr_mod(iter_var
, estate
);
446 return get_sm_state_expr(SMATCH_EXTRA
, iter_var
);
449 static struct sm_state
*handle_canonical_for_dec(struct expression
*iter_expr
,
450 struct expression
*condition
)
452 struct expression
*iter_var
;
454 struct smatch_state
*estate
;
457 iter_var
= iter_expr
->unop
;
458 sm
= get_sm_state_expr(SMATCH_EXTRA
, iter_var
);
461 if (!estate_get_single_value(sm
->state
, &start
))
463 if (!get_implied_min(condition
->right
, &end
))
464 end
= sval_type_min(get_type(iter_var
));
465 if (get_sm_state_expr(SMATCH_EXTRA
, condition
->left
) != sm
)
468 switch (condition
->op
) {
469 case SPECIAL_NOTEQUAL
:
471 if (!sval_is_min(end
) && !sval_is_max(end
))
479 if (sval_cmp(end
, start
) > 0)
481 estate
= alloc_estate_range(end
, start
);
482 estate_set_hard_max(estate
);
483 estate_set_fuzzy_max(estate
, estate_get_fuzzy_max(estate
));
484 set_extra_expr_mod(iter_var
, estate
);
485 return get_sm_state_expr(SMATCH_EXTRA
, iter_var
);
488 static struct sm_state
*handle_canonical_for_loops(struct statement
*loop
)
490 struct expression
*iter_expr
;
491 struct expression
*condition
;
493 if (!loop
->iterator_post_statement
)
495 if (loop
->iterator_post_statement
->type
!= STMT_EXPRESSION
)
497 iter_expr
= loop
->iterator_post_statement
->expression
;
498 if (!loop
->iterator_pre_condition
)
500 if (loop
->iterator_pre_condition
->type
!= EXPR_COMPARE
)
502 condition
= loop
->iterator_pre_condition
;
504 if (iter_expr
->op
== SPECIAL_INCREMENT
)
505 return handle_canonical_for_inc(iter_expr
, condition
);
506 if (iter_expr
->op
== SPECIAL_DECREMENT
)
507 return handle_canonical_for_dec(iter_expr
, condition
);
511 struct sm_state
*__extra_handle_canonical_loops(struct statement
*loop
, struct stree
**stree
)
513 struct sm_state
*ret
;
515 __push_fake_cur_stree();
516 if (!loop
->iterator_post_statement
)
517 ret
= handle_canonical_while_count_down(loop
);
519 ret
= handle_canonical_for_loops(loop
);
520 *stree
= __pop_fake_cur_stree();
524 int __iterator_unchanged(struct sm_state
*sm
)
528 if (get_sm_state(my_id
, sm
->name
, sm
->sym
) == sm
)
533 static void while_count_down_after(struct sm_state
*sm
, struct expression
*condition
)
537 /* paranoid checking. prolly not needed */
538 condition
= strip_expr(condition
);
541 if (condition
->type
!= EXPR_PREOP
&& condition
->type
!= EXPR_POSTOP
)
543 if (condition
->op
!= SPECIAL_DECREMENT
)
545 after_value
= estate_min(sm
->state
);
547 set_extra_mod(sm
->name
, sm
->sym
, alloc_estate_sval(after_value
));
550 void __extra_pre_loop_hook_after(struct sm_state
*sm
,
551 struct statement
*iterator
,
552 struct expression
*condition
)
554 struct expression
*iter_expr
;
556 struct smatch_state
*state
;
559 while_count_down_after(sm
, condition
);
563 iter_expr
= iterator
->expression
;
565 if (condition
->type
!= EXPR_COMPARE
)
567 if (iter_expr
->op
== SPECIAL_INCREMENT
) {
568 limit
= sval_binop(estate_max(sm
->state
), '+',
569 sval_type_val(estate_type(sm
->state
), 1));
571 limit
= sval_binop(estate_min(sm
->state
), '-',
572 sval_type_val(estate_type(sm
->state
), 1));
574 if (!estate_has_hard_max(sm
->state
) && !__has_breaks()) {
575 if (iter_expr
->op
== SPECIAL_INCREMENT
)
576 state
= alloc_estate_range(estate_min(sm
->state
), limit
);
578 state
= alloc_estate_range(limit
, estate_max(sm
->state
));
580 state
= alloc_estate_sval(limit
);
582 if (!estate_has_hard_max(sm
->state
)) {
583 estate_clear_hard_max(state
);
585 if (estate_has_fuzzy_max(sm
->state
)) {
586 sval_t hmax
= estate_get_fuzzy_max(sm
->state
);
587 sval_t max
= estate_max(sm
->state
);
589 if (sval_cmp(hmax
, max
) != 0)
590 estate_clear_fuzzy_max(state
);
591 } else if (!estate_has_fuzzy_max(sm
->state
)) {
592 estate_clear_fuzzy_max(state
);
595 set_extra_mod(sm
->name
, sm
->sym
, state
);
598 static struct stree
*unmatched_stree
;
599 static struct smatch_state
*unmatched_state(struct sm_state
*sm
)
601 struct smatch_state
*state
;
603 if (unmatched_stree
) {
604 state
= get_state_stree(unmatched_stree
, SMATCH_EXTRA
, sm
->name
, sm
->sym
);
608 if (parent_is_gone_var_sym(sm
->name
, sm
->sym
))
609 return alloc_estate_empty();
610 return alloc_estate_whole(estate_type(sm
->state
));
613 static void clear_the_pointed_at(struct expression
*expr
)
618 struct sm_state
*tmp
;
620 name
= expr_to_var_sym(expr
, &sym
);
624 stree
= __get_cur_stree();
625 FOR_EACH_MY_SM(SMATCH_EXTRA
, stree
, tmp
) {
626 if (tmp
->name
[0] != '*')
630 if (strcmp(tmp
->name
+ 1, name
) != 0)
632 set_extra_mod(tmp
->name
, tmp
->sym
, alloc_estate_whole(estate_type(tmp
->state
)));
633 } END_FOR_EACH_SM(tmp
);
639 static void match_function_call(struct expression
*expr
)
641 struct expression
*arg
;
642 struct expression
*tmp
;
644 /* if we have the db this is handled in smatch_function_hooks.c */
647 if (inlinable(expr
->fn
))
650 FOR_EACH_PTR(expr
->args
, arg
) {
651 tmp
= strip_expr(arg
);
652 if (tmp
->type
== EXPR_PREOP
&& tmp
->op
== '&')
653 set_extra_expr_mod(tmp
->unop
, alloc_estate_whole(get_type(tmp
->unop
)));
655 clear_the_pointed_at(tmp
);
656 } END_FOR_EACH_PTR(arg
);
659 static int values_fit_type(struct expression
*left
, struct expression
*right
)
661 struct range_list
*rl
;
664 type
= get_type(left
);
667 get_absolute_rl(right
, &rl
);
668 if (type_unsigned(type
) && sval_is_negative(rl_min(rl
)))
670 if (sval_cmp(sval_type_min(type
), rl_min(rl
)) > 0)
672 if (sval_cmp(sval_type_max(type
), rl_max(rl
)) < 0)
677 static void save_chunk_info(struct expression
*left
, struct expression
*right
)
679 struct var_sym_list
*vsl
;
681 struct expression
*add_expr
;
687 if (right
->type
!= EXPR_BINOP
|| right
->op
!= '-')
689 if (!get_value(right
->left
, &sval
))
691 if (!expr_to_sym(right
->right
))
694 add_expr
= binop_expression(left
, '+', right
->right
);
695 type
= get_type(add_expr
);
698 name
= expr_to_chunk_sym_vsl(add_expr
, &sym
, &vsl
);
701 FOR_EACH_PTR(vsl
, vs
) {
702 store_link(link_id
, vs
->var
, vs
->sym
, name
, sym
);
703 } END_FOR_EACH_PTR(vs
);
705 set_state(SMATCH_EXTRA
, name
, sym
, alloc_estate_sval(sval_cast(type
, sval
)));
710 static void do_array_assign(struct expression
*left
, int op
, struct expression
*right
)
712 struct range_list
*rl
;
715 get_absolute_rl(right
, &rl
);
716 rl
= cast_rl(get_type(left
), rl
);
718 rl
= alloc_whole_rl(get_type(left
));
721 set_extra_array_mod(left
, alloc_estate_rl(rl
));
724 static void match_untracked_array(struct expression
*call
, int param
)
726 struct expression
*arg
;
728 arg
= get_argument_from_call_expr(call
->args
, param
);
729 arg
= strip_expr(arg
);
731 clear_array_states(arg
);
734 static void match_vanilla_assign(struct expression
*left
, struct expression
*right
)
736 struct range_list
*orig_rl
= NULL
;
737 struct range_list
*rl
= NULL
;
738 struct symbol
*right_sym
;
739 struct symbol
*left_type
;
740 struct symbol
*right_type
;
741 char *right_name
= NULL
;
745 struct smatch_state
*state
;
751 save_chunk_info(left
, right
);
753 name
= expr_to_var_sym(left
, &sym
);
756 do_array_assign(left
, '=', right
);
760 left_type
= get_type(left
);
761 right_type
= get_type(right
);
763 right_name
= expr_to_var_sym(right
, &right_sym
);
765 if (!__in_fake_assign
&&
766 !(right
->type
== EXPR_PREOP
&& right
->op
== '&') &&
767 right_name
&& right_sym
&&
768 values_fit_type(left
, right
) &&
769 !has_symbol(right
, sym
)) {
770 set_equiv(left
, right
);
774 if (is_pointer(right
) && get_address_rl(right
, &rl
)) {
775 state
= alloc_estate_rl(rl
);
779 comparison
= get_comparison(left
, right
);
781 comparison
= flip_comparison(comparison
);
782 get_implied_rl(left
, &orig_rl
);
785 if (get_implied_rl(right
, &rl
)) {
786 rl
= cast_rl(left_type
, rl
);
788 filter_by_comparison(&rl
, comparison
, orig_rl
);
789 state
= alloc_estate_rl(rl
);
790 if (get_hard_max(right
, &max
)) {
791 estate_set_hard_max(state
);
792 estate_set_fuzzy_max(state
, max
);
795 rl
= alloc_whole_rl(right_type
);
796 rl
= cast_rl(left_type
, rl
);
798 filter_by_comparison(&rl
, comparison
, orig_rl
);
799 state
= alloc_estate_rl(rl
);
803 set_extra_mod(name
, sym
, state
);
805 free_string(right_name
);
808 static int op_remove_assign(int op
)
811 case SPECIAL_ADD_ASSIGN
:
813 case SPECIAL_SUB_ASSIGN
:
815 case SPECIAL_MUL_ASSIGN
:
817 case SPECIAL_DIV_ASSIGN
:
819 case SPECIAL_MOD_ASSIGN
:
821 case SPECIAL_AND_ASSIGN
:
823 case SPECIAL_OR_ASSIGN
:
825 case SPECIAL_XOR_ASSIGN
:
827 case SPECIAL_SHL_ASSIGN
:
828 return SPECIAL_LEFTSHIFT
;
829 case SPECIAL_SHR_ASSIGN
:
830 return SPECIAL_RIGHTSHIFT
;
836 static void match_assign(struct expression
*expr
)
838 struct range_list
*rl
= NULL
;
839 struct expression
*left
;
840 struct expression
*right
;
841 struct expression
*binop_expr
;
842 struct symbol
*left_type
;
843 struct symbol
*right_type
;
846 sval_t left_min
, left_max
;
847 sval_t right_min
, right_max
;
848 sval_t res_min
, res_max
;
850 left
= strip_expr(expr
->left
);
852 right
= strip_parens(expr
->right
);
853 if (right
->type
== EXPR_CALL
&& sym_name_is("__builtin_expect", right
->fn
))
854 right
= get_argument_from_call_expr(right
->args
, 0);
855 while (right
->type
== EXPR_ASSIGNMENT
&& right
->op
== '=')
856 right
= strip_parens(right
->left
);
858 if (expr
->op
== '=' && is_condition(expr
->right
))
859 return; /* handled in smatch_condition.c */
860 if (expr
->op
== '=' && right
->type
== EXPR_CALL
)
861 return; /* handled in smatch_function_hooks.c */
862 if (expr
->op
== '=') {
863 match_vanilla_assign(left
, right
);
867 name
= expr_to_var_sym(left
, &sym
);
871 left_type
= get_type(left
);
872 right_type
= get_type(right
);
874 res_min
= sval_type_min(left_type
);
875 res_max
= sval_type_max(left_type
);
878 case SPECIAL_ADD_ASSIGN
:
879 get_absolute_max(left
, &left_max
);
880 get_absolute_max(right
, &right_max
);
881 if (sval_binop_overflows(left_max
, '+', right_max
))
883 if (get_implied_min(left
, &left_min
) &&
884 !sval_is_negative_min(left_min
) &&
885 get_implied_min(right
, &right_min
) &&
886 !sval_is_negative_min(right_min
)) {
887 res_min
= sval_binop(left_min
, '+', right_min
);
888 res_min
= sval_cast(right_type
, res_min
);
890 if (inside_loop()) /* we are assuming loops don't lead to wrapping */
892 res_max
= sval_binop(left_max
, '+', right_max
);
893 res_max
= sval_cast(right_type
, res_max
);
895 case SPECIAL_SUB_ASSIGN
:
896 if (get_implied_max(left
, &left_max
) &&
897 !sval_is_max(left_max
) &&
898 get_implied_min(right
, &right_min
) &&
899 !sval_is_min(right_min
)) {
900 res_max
= sval_binop(left_max
, '-', right_min
);
901 res_max
= sval_cast(right_type
, res_max
);
905 if (get_implied_min(left
, &left_min
) &&
906 !sval_is_min(left_min
) &&
907 get_implied_max(right
, &right_max
) &&
908 !sval_is_max(right_max
)) {
909 res_min
= sval_binop(left_min
, '-', right_max
);
910 res_min
= sval_cast(right_type
, res_min
);
913 case SPECIAL_AND_ASSIGN
:
914 case SPECIAL_MOD_ASSIGN
:
915 case SPECIAL_SHL_ASSIGN
:
916 case SPECIAL_SHR_ASSIGN
:
917 case SPECIAL_OR_ASSIGN
:
918 case SPECIAL_XOR_ASSIGN
:
919 case SPECIAL_MUL_ASSIGN
:
920 case SPECIAL_DIV_ASSIGN
:
921 binop_expr
= binop_expression(expr
->left
,
922 op_remove_assign(expr
->op
),
924 if (get_absolute_rl(binop_expr
, &rl
)) {
925 rl
= cast_rl(left_type
, rl
);
926 set_extra_mod(name
, sym
, alloc_estate_rl(rl
));
931 rl
= cast_rl(left_type
, alloc_rl(res_min
, res_max
));
932 set_extra_mod(name
, sym
, alloc_estate_rl(rl
));
937 static struct smatch_state
*increment_state(struct smatch_state
*state
)
939 sval_t min
= estate_min(state
);
940 sval_t max
= estate_max(state
);
942 if (!estate_rl(state
))
946 max
= sval_type_max(max
.type
);
948 if (!sval_is_min(min
) && !sval_is_max(min
))
950 if (!sval_is_min(max
) && !sval_is_max(max
))
952 return alloc_estate_range(min
, max
);
955 static struct smatch_state
*decrement_state(struct smatch_state
*state
)
957 sval_t min
= estate_min(state
);
958 sval_t max
= estate_max(state
);
960 if (!estate_rl(state
))
964 min
= sval_type_min(min
.type
);
966 if (!sval_is_min(min
) && !sval_is_max(min
))
968 if (!sval_is_min(max
) && !sval_is_max(max
))
970 return alloc_estate_range(min
, max
);
973 static void unop_expr(struct expression
*expr
)
975 struct smatch_state
*state
;
977 if (expr
->smatch_flags
& Handled
)
981 case SPECIAL_INCREMENT
:
982 state
= get_state_expr(SMATCH_EXTRA
, expr
->unop
);
983 state
= increment_state(state
);
985 state
= alloc_estate_whole(get_type(expr
));
986 set_extra_expr_mod(expr
->unop
, state
);
988 case SPECIAL_DECREMENT
:
989 state
= get_state_expr(SMATCH_EXTRA
, expr
->unop
);
990 state
= decrement_state(state
);
992 state
= alloc_estate_whole(get_type(expr
));
993 set_extra_expr_mod(expr
->unop
, state
);
1000 static void asm_expr(struct statement
*stmt
)
1003 struct expression
*expr
;
1004 struct symbol
*type
;
1007 FOR_EACH_PTR(stmt
->asm_outputs
, expr
) {
1009 case 0: /* identifier */
1010 case 1: /* constraint */
1013 case 2: /* expression */
1015 type
= get_type(strip_expr(expr
));
1016 set_extra_expr_mod(expr
, alloc_estate_whole(type
));
1019 } END_FOR_EACH_PTR(expr
);
1022 static void check_dereference(struct expression
*expr
)
1024 if (outside_of_function())
1026 set_extra_expr_nomod(expr
, alloc_estate_range(valid_ptr_min_sval
, valid_ptr_max_sval
));
1029 static void match_dereferences(struct expression
*expr
)
1031 if (expr
->type
!= EXPR_PREOP
)
1033 check_dereference(expr
->unop
);
1036 static void match_pointer_as_array(struct expression
*expr
)
1038 if (!is_array(expr
))
1040 check_dereference(get_array_base(expr
));
1043 static void set_param_dereferenced(struct expression
*arg
, char *key
, char *unused
)
1048 name
= get_variable_from_key(arg
, key
, &sym
);
1052 set_extra_nomod(name
, sym
, alloc_estate_range(valid_ptr_min_sval
, valid_ptr_max_sval
));
1058 static sval_t
add_one(sval_t sval
)
1064 static sval_t
sub_one(sval_t sval
)
1070 static int handle_postop_inc(struct expression
*left
, int op
, struct expression
*right
)
1072 struct statement
*stmt
;
1073 struct expression
*cond
;
1074 struct smatch_state
*true_state
, *false_state
;
1079 * If we're decrementing here then that's a canonical while count down
1080 * so it's handled already. We're only handling loops like:
1082 * do { ... } while (i++ < 3);
1085 if (left
->type
!= EXPR_POSTOP
|| left
->op
!= SPECIAL_INCREMENT
)
1088 stmt
= __cur_stmt
->parent
;
1091 if (stmt
->type
== STMT_COMPOUND
)
1092 stmt
= stmt
->parent
;
1093 if (!stmt
|| stmt
->type
!= STMT_ITERATOR
|| !stmt
->iterator_post_condition
)
1096 cond
= strip_expr(stmt
->iterator_post_condition
);
1097 if (cond
->type
!= EXPR_COMPARE
|| cond
->op
!= op
)
1099 if (left
!= strip_expr(cond
->left
) || right
!= strip_expr(cond
->right
))
1102 if (!get_implied_value(left
->unop
, &start
))
1104 if (!get_implied_value(right
, &limit
))
1107 if (sval_cmp(start
, limit
) > 0)
1112 case SPECIAL_UNSIGNED_LT
:
1115 case SPECIAL_UNSIGNED_LTE
:
1116 limit
= add_one(limit
);
1122 true_state
= alloc_estate_range(add_one(start
), limit
);
1123 false_state
= alloc_estate_range(add_one(limit
), add_one(limit
));
1125 /* Currently we just discard the false state but when two passes is
1126 * implimented correctly then it will use it.
1129 set_extra_expr_true_false(left
->unop
, true_state
, false_state
);
1134 static void handle_comparison(struct symbol
*type
, struct expression
*left
, int op
, struct expression
*right
)
1136 struct range_list
*left_orig
;
1137 struct range_list
*left_true
;
1138 struct range_list
*left_false
;
1139 struct range_list
*right_orig
;
1140 struct range_list
*right_true
;
1141 struct range_list
*right_false
;
1142 struct smatch_state
*left_true_state
;
1143 struct smatch_state
*left_false_state
;
1144 struct smatch_state
*right_true_state
;
1145 struct smatch_state
*right_false_state
;
1146 sval_t min
, max
, dummy
, hard_max
;
1147 int left_postop
= 0;
1148 int right_postop
= 0;
1150 if (left
->op
== SPECIAL_INCREMENT
|| left
->op
== SPECIAL_DECREMENT
) {
1151 if (left
->type
== EXPR_POSTOP
) {
1152 left
->smatch_flags
|= Handled
;
1153 left_postop
= left
->op
;
1154 if (handle_postop_inc(left
, op
, right
))
1157 left
= strip_parens(left
->unop
);
1159 while (left
->type
== EXPR_ASSIGNMENT
)
1160 left
= strip_parens(left
->left
);
1162 if (right
->op
== SPECIAL_INCREMENT
|| right
->op
== SPECIAL_DECREMENT
) {
1163 if (right
->type
== EXPR_POSTOP
) {
1164 right
->smatch_flags
|= Handled
;
1165 right_postop
= right
->op
;
1167 right
= strip_parens(right
->unop
);
1170 /* FIXME: we should be able to use get_real_absolute_rl() here but
1171 * apparently that is buggy.
1173 get_absolute_rl(left
, &left_orig
);
1174 left_orig
= cast_rl(type
, left_orig
);
1176 get_absolute_rl(right
, &right_orig
);
1177 right_orig
= cast_rl(type
, right_orig
);
1179 min
= sval_type_min(type
);
1180 max
= sval_type_max(type
);
1182 left_true
= clone_rl(left_orig
);
1183 left_false
= clone_rl(left_orig
);
1184 right_true
= clone_rl(right_orig
);
1185 right_false
= clone_rl(right_orig
);
1189 case SPECIAL_UNSIGNED_LT
:
1190 left_true
= remove_range(left_orig
, rl_max(right_orig
), max
);
1191 if (!sval_is_min(rl_min(right_orig
))) {
1192 left_false
= remove_range(left_orig
, min
, sub_one(rl_min(right_orig
)));
1195 right_true
= remove_range(right_orig
, min
, rl_min(left_orig
));
1196 if (!sval_is_max(rl_max(left_orig
)))
1197 right_false
= remove_range(right_orig
, add_one(rl_max(left_orig
)), max
);
1199 case SPECIAL_UNSIGNED_LTE
:
1201 if (!sval_is_max(rl_max(right_orig
)))
1202 left_true
= remove_range(left_orig
, add_one(rl_max(right_orig
)), max
);
1203 left_false
= remove_range(left_orig
, min
, rl_min(right_orig
));
1205 if (!sval_is_min(rl_min(left_orig
)))
1206 right_true
= remove_range(right_orig
, min
, sub_one(rl_min(left_orig
)));
1207 right_false
= remove_range(right_orig
, rl_max(left_orig
), max
);
1209 if (sval_cmp(rl_min(left_orig
), rl_min(right_orig
)) == 0)
1210 left_false
= remove_range(left_false
, rl_min(left_orig
), rl_min(left_orig
));
1211 if (sval_cmp(rl_max(left_orig
), rl_max(right_orig
)) == 0)
1212 right_false
= remove_range(right_false
, rl_max(left_orig
), rl_max(left_orig
));
1215 if (!sval_is_max(rl_max(right_orig
))) {
1216 left_true
= remove_range(left_true
, add_one(rl_max(right_orig
)), max
);
1218 if (!sval_is_min(rl_min(right_orig
))) {
1219 left_true
= remove_range(left_true
, min
, sub_one(rl_min(right_orig
)));
1221 if (sval_cmp(rl_min(right_orig
), rl_max(right_orig
)) == 0)
1222 left_false
= remove_range(left_orig
, rl_min(right_orig
), rl_min(right_orig
));
1224 if (!sval_is_max(rl_max(left_orig
)))
1225 right_true
= remove_range(right_true
, add_one(rl_max(left_orig
)), max
);
1226 if (!sval_is_min(rl_min(left_orig
)))
1227 right_true
= remove_range(right_true
, min
, sub_one(rl_min(left_orig
)));
1228 if (sval_cmp(rl_min(left_orig
), rl_max(left_orig
)) == 0)
1229 right_false
= remove_range(right_orig
, rl_min(left_orig
), rl_min(left_orig
));
1231 case SPECIAL_UNSIGNED_GTE
:
1233 if (!sval_is_min(rl_min(right_orig
)))
1234 left_true
= remove_range(left_orig
, min
, sub_one(rl_min(right_orig
)));
1235 left_false
= remove_range(left_orig
, rl_max(right_orig
), max
);
1237 if (!sval_is_max(rl_max(left_orig
)))
1238 right_true
= remove_range(right_orig
, add_one(rl_max(left_orig
)), max
);
1239 right_false
= remove_range(right_orig
, min
, rl_min(left_orig
));
1241 if (sval_cmp(rl_min(left_orig
), rl_min(right_orig
)) == 0)
1242 right_false
= remove_range(right_false
, rl_min(left_orig
), rl_min(left_orig
));
1243 if (sval_cmp(rl_max(left_orig
), rl_max(right_orig
)) == 0)
1244 left_false
= remove_range(left_false
, rl_max(left_orig
), rl_max(left_orig
));
1247 case SPECIAL_UNSIGNED_GT
:
1248 left_true
= remove_range(left_orig
, min
, rl_min(right_orig
));
1249 if (!sval_is_max(rl_max(right_orig
)))
1250 left_false
= remove_range(left_orig
, add_one(rl_max(right_orig
)), max
);
1252 right_true
= remove_range(right_orig
, rl_max(left_orig
), max
);
1253 if (!sval_is_min(rl_min(left_orig
)))
1254 right_false
= remove_range(right_orig
, min
, sub_one(rl_min(left_orig
)));
1256 case SPECIAL_NOTEQUAL
:
1257 if (!sval_is_max(rl_max(right_orig
)))
1258 left_false
= remove_range(left_false
, add_one(rl_max(right_orig
)), max
);
1259 if (!sval_is_min(rl_min(right_orig
)))
1260 left_false
= remove_range(left_false
, min
, sub_one(rl_min(right_orig
)));
1261 if (sval_cmp(rl_min(right_orig
), rl_max(right_orig
)) == 0)
1262 left_true
= remove_range(left_orig
, rl_min(right_orig
), rl_min(right_orig
));
1264 if (!sval_is_max(rl_max(left_orig
)))
1265 right_false
= remove_range(right_false
, add_one(rl_max(left_orig
)), max
);
1266 if (!sval_is_min(rl_min(left_orig
)))
1267 right_false
= remove_range(right_false
, min
, sub_one(rl_min(left_orig
)));
1268 if (sval_cmp(rl_min(left_orig
), rl_max(left_orig
)) == 0)
1269 right_true
= remove_range(right_orig
, rl_min(left_orig
), rl_min(left_orig
));
1275 left_true
= rl_truncate_cast(get_type(strip_expr(left
)), left_true
);
1276 left_false
= rl_truncate_cast(get_type(strip_expr(left
)), left_false
);
1277 right_true
= rl_truncate_cast(get_type(strip_expr(right
)), right_true
);
1278 right_false
= rl_truncate_cast(get_type(strip_expr(right
)), right_false
);
1280 left_true_state
= alloc_estate_rl(left_true
);
1281 left_false_state
= alloc_estate_rl(left_false
);
1282 right_true_state
= alloc_estate_rl(right_true
);
1283 right_false_state
= alloc_estate_rl(right_false
);
1287 case SPECIAL_UNSIGNED_LT
:
1288 case SPECIAL_UNSIGNED_LTE
:
1290 if (get_hard_max(right
, &dummy
))
1291 estate_set_hard_max(left_true_state
);
1292 if (get_hard_max(left
, &dummy
))
1293 estate_set_hard_max(right_false_state
);
1296 case SPECIAL_UNSIGNED_GT
:
1297 case SPECIAL_UNSIGNED_GTE
:
1299 if (get_hard_max(left
, &dummy
))
1300 estate_set_hard_max(right_true_state
);
1301 if (get_hard_max(right
, &dummy
))
1302 estate_set_hard_max(left_false_state
);
1308 case SPECIAL_UNSIGNED_LT
:
1309 case SPECIAL_UNSIGNED_LTE
:
1311 if (get_hard_max(right
, &hard_max
)) {
1312 if (op
== '<' || op
== SPECIAL_UNSIGNED_LT
)
1314 estate_set_fuzzy_max(left_true_state
, hard_max
);
1316 if (get_implied_value(right
, &hard_max
)) {
1317 if (op
== SPECIAL_UNSIGNED_LTE
||
1320 estate_set_fuzzy_max(left_false_state
, hard_max
);
1322 if (get_hard_max(left
, &hard_max
)) {
1323 if (op
== SPECIAL_UNSIGNED_LTE
||
1326 estate_set_fuzzy_max(right_false_state
, hard_max
);
1328 if (get_implied_value(left
, &hard_max
)) {
1329 if (op
== '<' || op
== SPECIAL_UNSIGNED_LT
)
1331 estate_set_fuzzy_max(right_true_state
, hard_max
);
1335 case SPECIAL_UNSIGNED_GT
:
1336 case SPECIAL_UNSIGNED_GTE
:
1338 if (get_hard_max(left
, &hard_max
)) {
1339 if (op
== '>' || op
== SPECIAL_UNSIGNED_GT
)
1341 estate_set_fuzzy_max(right_true_state
, hard_max
);
1343 if (get_implied_value(left
, &hard_max
)) {
1344 if (op
== SPECIAL_UNSIGNED_GTE
||
1347 estate_set_fuzzy_max(right_false_state
, hard_max
);
1349 if (get_hard_max(right
, &hard_max
)) {
1350 if (op
== SPECIAL_UNSIGNED_LTE
||
1353 estate_set_fuzzy_max(left_false_state
, hard_max
);
1355 if (get_implied_value(right
, &hard_max
)) {
1357 op
== SPECIAL_UNSIGNED_GT
)
1359 estate_set_fuzzy_max(left_true_state
, hard_max
);
1363 if (get_hard_max(left
, &hard_max
))
1364 estate_set_fuzzy_max(right_true_state
, hard_max
);
1365 if (get_hard_max(right
, &hard_max
))
1366 estate_set_fuzzy_max(left_true_state
, hard_max
);
1370 if (get_hard_max(left
, &hard_max
)) {
1371 estate_set_hard_max(left_true_state
);
1372 estate_set_hard_max(left_false_state
);
1374 if (get_hard_max(right
, &hard_max
)) {
1375 estate_set_hard_max(right_true_state
);
1376 estate_set_hard_max(right_false_state
);
1379 if (left_postop
== SPECIAL_INCREMENT
) {
1380 left_true_state
= increment_state(left_true_state
);
1381 left_false_state
= increment_state(left_false_state
);
1383 if (left_postop
== SPECIAL_DECREMENT
) {
1384 left_true_state
= decrement_state(left_true_state
);
1385 left_false_state
= decrement_state(left_false_state
);
1387 if (right_postop
== SPECIAL_INCREMENT
) {
1388 right_true_state
= increment_state(right_true_state
);
1389 right_false_state
= increment_state(right_false_state
);
1391 if (right_postop
== SPECIAL_DECREMENT
) {
1392 right_true_state
= decrement_state(right_true_state
);
1393 right_false_state
= decrement_state(right_false_state
);
1396 if (estate_rl(left_true_state
) && estates_equiv(left_true_state
, left_false_state
)) {
1397 left_true_state
= NULL
;
1398 left_false_state
= NULL
;
1401 if (estate_rl(right_true_state
) && estates_equiv(right_true_state
, right_false_state
)) {
1402 right_true_state
= NULL
;
1403 right_false_state
= NULL
;
1406 set_extra_expr_true_false(left
, left_true_state
, left_false_state
);
1407 set_extra_expr_true_false(right
, right_true_state
, right_false_state
);
1410 static int is_simple_math(struct expression
*expr
)
1414 if (expr
->type
!= EXPR_BINOP
)
1425 static void move_known_values(struct expression
**left_p
, struct expression
**right_p
)
1427 struct expression
*left
= *left_p
;
1428 struct expression
*right
= *right_p
;
1431 if (get_implied_value(left
, &sval
)) {
1432 if (!is_simple_math(right
))
1434 if (right
->op
== '*') {
1437 if (!get_value(right
->right
, &divisor
))
1439 if (divisor
.value
== 0 && sval
.value
% divisor
.value
)
1441 *left_p
= binop_expression(left
, invert_op(right
->op
), right
->right
);
1442 *right_p
= right
->left
;
1445 if (right
->op
== '+' && get_value(right
->left
, &sval
)) {
1446 *left_p
= binop_expression(left
, invert_op(right
->op
), right
->left
);
1447 *right_p
= right
->right
;
1450 if (get_value(right
->right
, &sval
)) {
1451 *left_p
= binop_expression(left
, invert_op(right
->op
), right
->right
);
1452 *right_p
= right
->left
;
1457 if (get_implied_value(right
, &sval
)) {
1458 if (!is_simple_math(left
))
1460 if (left
->op
== '*') {
1463 if (!get_value(left
->right
, &divisor
))
1465 if (divisor
.value
== 0 && sval
.value
% divisor
.value
)
1467 *right_p
= binop_expression(right
, invert_op(left
->op
), left
->right
);
1468 *left_p
= left
->left
;
1471 if (left
->op
== '+' && get_value(left
->left
, &sval
)) {
1472 *right_p
= binop_expression(right
, invert_op(left
->op
), left
->left
);
1473 *left_p
= left
->right
;
1477 if (get_value(left
->right
, &sval
)) {
1478 *right_p
= binop_expression(right
, invert_op(left
->op
), left
->right
);
1479 *left_p
= left
->left
;
1486 static int match_func_comparison(struct expression
*expr
)
1488 struct expression
*left
= strip_expr(expr
->left
);
1489 struct expression
*right
= strip_expr(expr
->right
);
1493 * fixme: think about this harder. We should always be trying to limit
1494 * the non-call side as well. If we can't determine the limitter does
1495 * that mean we aren't querying the database and are missing important
1499 if (left
->type
== EXPR_CALL
) {
1500 if (get_implied_value(left
, &sval
)) {
1501 handle_comparison(get_type(expr
), left
, expr
->op
, right
);
1504 function_comparison(left
, expr
->op
, right
);
1508 if (right
->type
== EXPR_CALL
) {
1509 if (get_implied_value(right
, &sval
)) {
1510 handle_comparison(get_type(expr
), left
, expr
->op
, right
);
1513 function_comparison(left
, expr
->op
, right
);
1520 static void match_comparison(struct expression
*expr
)
1522 struct expression
*left_orig
= strip_parens(expr
->left
);
1523 struct expression
*right_orig
= strip_parens(expr
->right
);
1524 struct expression
*left
, *right
;
1525 struct expression
*prev
;
1526 struct symbol
*type
;
1528 if (match_func_comparison(expr
))
1531 type
= get_type(expr
);
1533 type
= &llong_ctype
;
1537 move_known_values(&left
, &right
);
1538 handle_comparison(type
, left
, expr
->op
, right
);
1540 prev
= get_assigned_expr(left_orig
);
1541 if (is_simple_math(prev
) && has_variable(prev
, left_orig
) == 0) {
1544 move_known_values(&left
, &right
);
1545 handle_comparison(type
, left
, expr
->op
, right
);
1548 prev
= get_assigned_expr(right_orig
);
1549 if (is_simple_math(prev
) && has_variable(prev
, right_orig
) == 0) {
1552 move_known_values(&left
, &right
);
1553 handle_comparison(type
, left
, expr
->op
, right
);
1557 static void handle_AND_condition(struct expression
*expr
)
1559 struct range_list
*rl
= NULL
;
1562 if (get_implied_value(expr
->left
, &known
) && known
.value
> 0) {
1564 get_absolute_rl(expr
->right
, &rl
);
1565 rl
= remove_range(rl
, sval_type_val(known
.type
, 0), known
);
1566 set_extra_expr_true_false(expr
->right
, alloc_estate_rl(rl
), NULL
);
1570 if (get_implied_value(expr
->right
, &known
) && known
.value
> 0) {
1572 get_absolute_rl(expr
->left
, &rl
);
1573 rl
= remove_range(rl
, sval_type_val(known
.type
, 0), known
);
1574 set_extra_expr_true_false(expr
->left
, alloc_estate_rl(rl
), NULL
);
1579 /* this is actually hooked from smatch_implied.c... it's hacky, yes */
1580 void __extra_match_condition(struct expression
*expr
)
1582 struct smatch_state
*pre_state
;
1583 struct smatch_state
*true_state
;
1584 struct smatch_state
*false_state
;
1586 expr
= strip_expr(expr
);
1587 switch (expr
->type
) {
1589 function_comparison(expr
, SPECIAL_NOTEQUAL
, zero_expr());
1596 zero
= sval_blank(expr
);
1599 pre_state
= get_extra_state(expr
);
1600 true_state
= estate_filter_sval(pre_state
, zero
);
1601 if (possibly_true(expr
, SPECIAL_EQUAL
, zero_expr()))
1602 false_state
= alloc_estate_sval(zero
);
1604 false_state
= alloc_estate_empty();
1605 set_extra_expr_true_false(expr
, true_state
, false_state
);
1609 match_comparison(expr
);
1611 case EXPR_ASSIGNMENT
:
1612 __extra_match_condition(expr
->left
);
1615 if (expr
->op
== '&')
1616 handle_AND_condition(expr
);
1621 static void assume_indexes_are_valid(struct expression
*expr
)
1623 struct expression
*array_expr
;
1625 struct expression
*offset
;
1626 struct symbol
*offset_type
;
1627 struct range_list
*rl_before
;
1628 struct range_list
*rl_after
;
1629 struct range_list
*filter
= NULL
;
1632 expr
= strip_expr(expr
);
1633 if (!is_array(expr
))
1636 offset
= get_array_offset(expr
);
1637 offset_type
= get_type(offset
);
1638 if (offset_type
&& type_signed(offset_type
)) {
1639 filter
= alloc_rl(sval_type_min(offset_type
),
1640 sval_type_val(offset_type
, -1));
1643 array_expr
= get_array_base(expr
);
1644 array_size
= get_real_array_size(array_expr
);
1645 if (array_size
> 1) {
1646 size
= sval_type_val(offset_type
, array_size
);
1647 add_range(&filter
, size
, sval_type_max(offset_type
));
1652 get_absolute_rl(offset
, &rl_before
);
1653 rl_after
= rl_filter(rl_before
, filter
);
1654 if (rl_equiv(rl_before
, rl_after
))
1656 set_extra_expr_nomod(offset
, alloc_estate_rl(rl_after
));
1659 /* returns 1 if it is not possible for expr to be value, otherwise returns 0 */
1660 int implied_not_equal(struct expression
*expr
, long long val
)
1662 return !possibly_false(expr
, SPECIAL_NOTEQUAL
, value_expr(val
));
1665 int implied_not_equal_name_sym(char *name
, struct symbol
*sym
, long long val
)
1667 struct smatch_state
*estate
;
1669 estate
= get_state(SMATCH_EXTRA
, name
, sym
);
1672 if (!rl_has_sval(estate_rl(estate
), sval_type_val(estate_type(estate
), 0)))
1677 int parent_is_null_var_sym(const char *name
, struct symbol
*sym
)
1682 struct smatch_state
*state
;
1684 strncpy(buf
, name
, sizeof(buf
) - 1);
1685 buf
[sizeof(buf
) - 1] = '\0';
1688 while (*start
== '*') {
1690 state
= get_state(SMATCH_EXTRA
, start
, sym
);
1693 if (!estate_rl(state
))
1695 if (estate_min(state
).value
== 0 &&
1696 estate_max(state
).value
== 0)
1701 while (*start
== '&')
1704 while ((end
= strrchr(start
, '-'))) {
1706 state
= get_state(SMATCH_EXTRA
, start
, sym
);
1709 if (estate_min(state
).value
== 0 &&
1710 estate_max(state
).value
== 0)
1716 int parent_is_null(struct expression
*expr
)
1722 expr
= strip_expr(expr
);
1723 var
= expr_to_var_sym(expr
, &sym
);
1726 ret
= parent_is_null_var_sym(var
, sym
);
1732 static int param_used_callback(void *found
, int argc
, char **argv
, char **azColName
)
1738 static int filter_unused_kzalloc_info(struct expression
*call
, int param
, char *printed_name
, struct sm_state
*sm
)
1743 /* for function pointers assume everything is used */
1744 if (call
->fn
->type
!= EXPR_SYMBOL
)
1748 * kzalloc() information is treated as special because so there is just
1749 * a lot of stuff initialized to zero and it makes building the database
1750 * take hours and hours.
1752 * In theory, we should just remove this line and not pass any unused
1753 * information, but I'm not sure enough that this code works so I want
1754 * to hold off on that for now.
1756 if (!estate_get_single_value(sm
->state
, &sval
) || sval
.value
!= 0)
1759 run_sql(¶m_used_callback
, &found
,
1760 "select * from call_implies where %s and type = %d and parameter = %d and key = '%s';",
1761 get_static_filter(call
->fn
->symbol
), PARAM_USED
, param
, printed_name
);
1765 /* If the database is not built yet, then assume everything is used */
1766 run_sql(¶m_used_callback
, &found
,
1767 "select * from call_implies where %s and type = %d;",
1768 get_static_filter(call
->fn
->symbol
), PARAM_USED
);
1775 static void struct_member_callback(struct expression
*call
, int param
, char *printed_name
, struct sm_state
*sm
)
1777 if (estate_is_whole(sm
->state
))
1779 if (filter_unused_kzalloc_info(call
, param
, printed_name
, sm
))
1781 sql_insert_caller_info(call
, PARAM_VALUE
, param
, printed_name
, sm
->state
->name
);
1782 if (estate_has_fuzzy_max(sm
->state
))
1783 sql_insert_caller_info(call
, FUZZY_MAX
, param
, printed_name
,
1784 sval_to_str(estate_get_fuzzy_max(sm
->state
)));
1787 static void returned_struct_members(int return_id
, char *return_ranges
, struct expression
*expr
)
1789 struct symbol
*returned_sym
;
1790 struct sm_state
*sm
;
1791 const char *param_name
;
1795 returned_sym
= expr_to_sym(expr
);
1799 FOR_EACH_MY_SM(my_id
, __get_cur_stree(), sm
) {
1800 if (!estate_rl(sm
->state
))
1802 if (returned_sym
!= sm
->sym
)
1805 param_name
= get_param_name(sm
);
1808 if (strcmp(param_name
, "$") == 0)
1810 compare_str
= name_sym_to_param_comparison(sm
->name
, sm
->sym
);
1811 if (!compare_str
&& estate_is_whole(sm
->state
))
1813 snprintf(buf
, sizeof(buf
), "%s%s", sm
->state
->name
, compare_str
?: "");
1815 sql_insert_return_states(return_id
, return_ranges
, PARAM_VALUE
,
1816 -1, param_name
, buf
);
1817 } END_FOR_EACH_SM(sm
);
1820 static void db_limited_before(void)
1822 unmatched_stree
= clone_stree(__get_cur_stree());
1825 static void db_limited_after(void)
1827 free_stree(&unmatched_stree
);
1830 static void db_param_limit_filter(struct expression
*expr
, int param
, char *key
, char *value
, enum info_type op
)
1832 struct expression
*arg
;
1835 struct sm_state
*sm
;
1836 struct symbol
*compare_type
, *var_type
;
1837 struct range_list
*rl
;
1838 struct range_list
*limit
;
1839 struct range_list
*new;
1841 while (expr
->type
== EXPR_ASSIGNMENT
)
1842 expr
= strip_expr(expr
->right
);
1843 if (expr
->type
!= EXPR_CALL
)
1846 arg
= get_argument_from_call_expr(expr
->args
, param
);
1850 name
= get_variable_from_key(arg
, key
, &sym
);
1854 if (strcmp(key
, "$") == 0)
1855 compare_type
= get_arg_type(expr
->fn
, param
);
1857 compare_type
= get_member_type_from_key(arg
, key
);
1859 sm
= get_sm_state(SMATCH_EXTRA
, name
, sym
);
1861 rl
= estate_rl(sm
->state
);
1863 rl
= alloc_whole_rl(compare_type
);
1865 call_results_to_rl(expr
, compare_type
, value
, &limit
);
1866 new = rl_intersection(rl
, limit
);
1868 var_type
= get_member_type_from_key(arg
, key
);
1869 new = cast_rl(var_type
, new);
1871 /* We want to preserve the implications here */
1872 if (sm
&& rl_equiv(estate_rl(sm
->state
), new))
1875 if (op
== PARAM_LIMIT
)
1876 set_extra_nomod(name
, sym
, alloc_estate_rl(new));
1878 set_extra_mod(name
, sym
, alloc_estate_rl(new));
1885 static void db_param_limit(struct expression
*expr
, int param
, char *key
, char *value
)
1887 db_param_limit_filter(expr
, param
, key
, value
, PARAM_LIMIT
);
1890 static void db_param_filter(struct expression
*expr
, int param
, char *key
, char *value
)
1892 db_param_limit_filter(expr
, param
, key
, value
, PARAM_FILTER
);
1895 static void db_param_add_set(struct expression
*expr
, int param
, char *key
, char *value
, enum info_type op
)
1897 struct expression
*arg
;
1900 struct symbol
*type
;
1901 struct smatch_state
*state
;
1902 struct range_list
*new = NULL
;
1903 struct range_list
*added
= NULL
;
1905 while (expr
->type
== EXPR_ASSIGNMENT
)
1906 expr
= strip_expr(expr
->right
);
1907 if (expr
->type
!= EXPR_CALL
)
1910 arg
= get_argument_from_call_expr(expr
->args
, param
);
1913 type
= get_member_type_from_key(arg
, key
);
1914 name
= get_variable_from_key(arg
, key
, &sym
);
1918 state
= get_state(SMATCH_EXTRA
, name
, sym
);
1920 new = estate_rl(state
);
1922 call_results_to_rl(expr
, type
, value
, &added
);
1924 if (op
== PARAM_SET
)
1927 new = rl_union(new, added
);
1929 set_extra_mod(name
, sym
, alloc_estate_rl(new));
1934 static void db_param_add(struct expression
*expr
, int param
, char *key
, char *value
)
1936 db_param_add_set(expr
, param
, key
, value
, PARAM_ADD
);
1939 static void db_param_set(struct expression
*expr
, int param
, char *key
, char *value
)
1941 db_param_add_set(expr
, param
, key
, value
, PARAM_SET
);
1944 static void db_param_value(struct expression
*expr
, int param
, char *key
, char *value
)
1946 struct expression
*call
;
1949 struct symbol
*type
;
1950 struct range_list
*rl
= NULL
;
1956 while (call
->type
== EXPR_ASSIGNMENT
)
1957 call
= strip_expr(call
->right
);
1958 if (call
->type
!= EXPR_CALL
)
1961 type
= get_member_type_from_key(expr
->left
, key
);
1962 name
= get_variable_from_key(expr
->left
, key
, &sym
);
1966 call_results_to_rl(call
, type
, value
, &rl
);
1968 set_extra_mod(name
, sym
, alloc_estate_rl(rl
));
1973 static void match_call_info(struct expression
*expr
)
1975 struct smatch_state
*state
;
1976 struct range_list
*rl
= NULL
;
1977 struct expression
*arg
;
1978 struct symbol
*type
;
1981 FOR_EACH_PTR(expr
->args
, arg
) {
1982 type
= get_arg_type(expr
->fn
, i
);
1984 if (get_implied_rl(arg
, &rl
))
1985 rl
= cast_rl(type
, rl
);
1987 rl
= cast_rl(type
, alloc_whole_rl(get_type(arg
)));
1989 if (!is_whole_rl(rl
))
1990 sql_insert_caller_info(expr
, PARAM_VALUE
, i
, "$", show_rl(rl
));
1991 state
= get_state_expr(SMATCH_EXTRA
, arg
);
1992 if (estate_has_fuzzy_max(state
)) {
1993 sql_insert_caller_info(expr
, FUZZY_MAX
, i
, "$",
1994 sval_to_str(estate_get_fuzzy_max(state
)));
1997 } END_FOR_EACH_PTR(arg
);
2000 static void set_param_value(const char *name
, struct symbol
*sym
, char *key
, char *value
)
2002 struct range_list
*rl
= NULL
;
2003 struct smatch_state
*state
;
2004 struct symbol
*type
;
2007 if (strcmp(key
, "*$") == 0)
2008 snprintf(fullname
, sizeof(fullname
), "*%s", name
);
2009 else if (strncmp(key
, "$", 1) == 0)
2010 snprintf(fullname
, 256, "%s%s", name
, key
+ 1);
2014 type
= get_member_type_from_key(symbol_expression(sym
), key
);
2015 str_to_rl(type
, value
, &rl
);
2016 state
= alloc_estate_rl(rl
);
2017 set_state(SMATCH_EXTRA
, fullname
, sym
, state
);
2020 static void set_param_hard_max(const char *name
, struct symbol
*sym
, char *key
, char *value
)
2022 struct range_list
*rl
= NULL
;
2023 struct smatch_state
*state
;
2024 struct symbol
*type
;
2028 if (strcmp(key
, "*$") == 0)
2029 snprintf(fullname
, sizeof(fullname
), "*%s", name
);
2030 else if (strncmp(key
, "$", 1) == 0)
2031 snprintf(fullname
, 256, "%s%s", name
, key
+ 1);
2035 state
= get_state(SMATCH_EXTRA
, fullname
, sym
);
2038 type
= get_member_type_from_key(symbol_expression(sym
), key
);
2039 str_to_rl(type
, value
, &rl
);
2040 if (!rl_to_sval(rl
, &max
))
2042 estate_set_fuzzy_max(state
, max
);
2045 struct smatch_state
*get_extra_state(struct expression
*expr
)
2049 struct smatch_state
*ret
= NULL
;
2050 struct range_list
*rl
;
2052 if (is_pointer(expr
) && get_address_rl(expr
, &rl
))
2053 return alloc_estate_rl(rl
);
2055 name
= expr_to_known_chunk_sym(expr
, &sym
);
2059 ret
= get_state(SMATCH_EXTRA
, name
, sym
);
2065 void register_smatch_extra(int id
)
2069 add_merge_hook(my_id
, &merge_estates
);
2070 add_unmatched_state_hook(my_id
, &unmatched_state
);
2071 select_caller_info_hook(set_param_value
, PARAM_VALUE
);
2072 select_caller_info_hook(set_param_hard_max
, FUZZY_MAX
);
2073 select_return_states_before(&db_limited_before
);
2074 select_return_states_hook(PARAM_LIMIT
, &db_param_limit
);
2075 select_return_states_hook(PARAM_FILTER
, &db_param_filter
);
2076 select_return_states_hook(PARAM_ADD
, &db_param_add
);
2077 select_return_states_hook(PARAM_SET
, &db_param_set
);
2078 select_return_states_hook(PARAM_VALUE
, &db_param_value
);
2079 select_return_states_after(&db_limited_after
);
2082 static void match_link_modify(struct sm_state
*sm
, struct expression
*mod_expr
)
2084 struct var_sym_list
*links
;
2085 struct var_sym
*tmp
;
2086 struct smatch_state
*state
;
2088 links
= sm
->state
->data
;
2090 FOR_EACH_PTR(links
, tmp
) {
2091 state
= get_state(SMATCH_EXTRA
, tmp
->var
, tmp
->sym
);
2094 set_state(SMATCH_EXTRA
, tmp
->var
, tmp
->sym
, alloc_estate_whole(estate_type(state
)));
2095 } END_FOR_EACH_PTR(tmp
);
2096 set_state(link_id
, sm
->name
, sm
->sym
, &undefined
);
2099 void register_smatch_extra_links(int id
)
2104 void register_smatch_extra_late(int id
)
2106 add_merge_hook(link_id
, &merge_link_states
);
2107 add_modification_hook(link_id
, &match_link_modify
);
2108 add_hook(&match_dereferences
, DEREF_HOOK
);
2109 add_hook(&match_pointer_as_array
, OP_HOOK
);
2110 select_call_implies_hook(DEREFERENCE
, &set_param_dereferenced
);
2111 add_hook(&match_function_call
, FUNCTION_CALL_HOOK
);
2112 add_hook(&match_assign
, ASSIGNMENT_HOOK
);
2113 add_hook(&match_assign
, GLOBAL_ASSIGNMENT_HOOK
);
2114 add_hook(&unop_expr
, OP_HOOK
);
2115 add_hook(&asm_expr
, ASM_HOOK
);
2116 add_untracked_param_hook(&match_untracked_array
);
2118 add_hook(&match_call_info
, FUNCTION_CALL_HOOK
);
2119 add_member_info_callback(my_id
, struct_member_callback
);
2120 add_split_return_callback(&returned_struct_members
);
2122 add_hook(&assume_indexes_are_valid
, OP_HOOK
);