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.
34 #include "smatch_slist.h"
35 #include "smatch_extra.h"
40 static void match_link_modify(struct sm_state
*sm
, struct expression
*mod_expr
);
42 struct string_list
*__ignored_macros
= NULL
;
43 int in_warn_on_macro(void)
45 struct statement
*stmt
;
49 stmt
= get_current_statement();
52 macro
= get_macro_name(stmt
->pos
);
56 FOR_EACH_PTR(__ignored_macros
, tmp
) {
57 if (!strcmp(tmp
, macro
))
59 } END_FOR_EACH_PTR(tmp
);
63 typedef void (mod_hook
)(const char *name
, struct symbol
*sym
, struct expression
*expr
, struct smatch_state
*state
);
64 DECLARE_PTR_LIST(mod_hook_list
, mod_hook
*);
65 static struct mod_hook_list
*extra_mod_hooks
;
66 static struct mod_hook_list
*extra_nomod_hooks
;
68 void add_extra_mod_hook(mod_hook
*fn
)
70 mod_hook
**p
= malloc(sizeof(mod_hook
*));
72 add_ptr_list(&extra_mod_hooks
, p
);
75 void add_extra_nomod_hook(mod_hook
*fn
)
77 mod_hook
**p
= malloc(sizeof(mod_hook
*));
79 add_ptr_list(&extra_nomod_hooks
, p
);
82 void call_extra_hooks(struct mod_hook_list
*hooks
, const char *name
, struct symbol
*sym
, struct expression
*expr
, struct smatch_state
*state
)
86 FOR_EACH_PTR(hooks
, fn
) {
87 (*fn
)(name
, sym
, expr
, state
);
88 } END_FOR_EACH_PTR(fn
);
91 void call_extra_mod_hooks(const char *name
, struct symbol
*sym
, struct expression
*expr
, struct smatch_state
*state
)
93 call_extra_hooks(extra_mod_hooks
, name
, sym
, expr
, state
);
96 void call_extra_nomod_hooks(const char *name
, struct symbol
*sym
, struct expression
*expr
, struct smatch_state
*state
)
98 call_extra_hooks(extra_nomod_hooks
, name
, sym
, expr
, state
);
101 static void set_union_info(const char *name
, struct symbol
*sym
, struct expression
*expr
, struct smatch_state
*state
)
103 struct symbol
*type
, *tmp
, *inner_type
, *inner
, *new_type
;
104 struct expression
*deref
, *member_expr
;
105 struct smatch_state
*new;
106 int offset
, inner_offset
;
107 static bool in_recurse
;
110 if (__in_fake_assign
)
117 if (!expr
|| expr
->type
!= EXPR_DEREF
|| !expr
->member
)
119 offset
= get_member_offset_from_deref(expr
);
123 deref
= strip_expr(expr
->deref
);
124 type
= get_type(deref
);
125 if (type_is_ptr(type
))
126 type
= get_real_base_type(type
);
127 if (!type
|| type
->type
!= SYM_STRUCT
)
130 FOR_EACH_PTR(type
->symbol_list
, tmp
) {
131 inner_type
= get_real_base_type(tmp
);
132 if (!inner_type
|| inner_type
->type
!= SYM_UNION
)
135 inner
= first_ptr_list((struct ptr_list
*)inner_type
->symbol_list
);
136 if (!inner
|| !inner
->ident
)
139 inner_offset
= get_member_offset(type
, inner
->ident
->name
);
140 if (inner_offset
< offset
)
142 if (inner_offset
> offset
)
145 FOR_EACH_PTR(inner_type
->symbol_list
, inner
) {
146 struct symbol
*tmp_type
;
148 if (!inner
->ident
|| inner
->ident
== expr
->member
)
150 tmp_type
= get_real_base_type(inner
);
151 if (tmp_type
&& tmp_type
->type
== SYM_STRUCT
)
155 member_expr
= member_expression(member_expr
, '.', tmp
->ident
);
156 member_expr
= member_expression(member_expr
, expr
->op
, inner
->ident
);
157 member_name
= expr_to_var(member_expr
);
160 new_type
= get_real_base_type(inner
);
161 new = alloc_estate_rl(cast_rl(new_type
, estate_rl(state
)));
162 set_extra_mod_helper(member_name
, sym
, member_expr
, new);
163 free_string(member_name
);
164 } END_FOR_EACH_PTR(inner
);
165 } END_FOR_EACH_PTR(tmp
);
171 extern int __no_limits
;
172 static void mark_sub_members_gone(const char *name
, struct symbol
*sym
, struct expression
*expr
, struct smatch_state
*state
)
176 if (__in_fake_assign
)
178 if (is_fake_var_assign(expr
))
181 if (!estate_type(state
) || estate_type(state
)->type
!= SYM_PTR
)
183 if (!is_noderef_ptr_rl(estate_rl(state
)))
186 FOR_EACH_MY_SM(SMATCH_EXTRA
, __get_cur_stree(), sm
) {
189 if (strcmp(name
, sm
->name
) == 0)
191 if (!is_sub_member(name
, sym
, sm
))
194 set_extra_nomod(sm
->name
, sm
->sym
, NULL
, alloc_estate_empty());
196 } END_FOR_EACH_SM(sm
);
199 static bool is_fake_assign(struct expression
*expr
)
201 struct expression
*faked
;
203 if (is_fake_var_assign(expr
))
206 faked
= get_faked_expression();
207 if (!faked
|| faked
->type
!= EXPR_ASSIGNMENT
|| faked
->op
!= '=')
210 faked
= strip_expr(faked
->right
);
211 if (faked
->type
== EXPR_PREOP
&& faked
->op
== '&')
217 static void call_update_mtag_data(struct expression
*expr
,
218 struct smatch_state
*state
)
220 if (is_fake_assign(expr
))
223 update_mtag_data(expr
, state
);
226 static bool in_param_set
;
227 void set_extra_mod_helper(const char *name
, struct symbol
*sym
, struct expression
*expr
, struct smatch_state
*state
)
230 expr
= gen_expression_from_name_sym(name
, sym
);
231 remove_from_equiv(name
, sym
);
232 set_union_info(name
, sym
, expr
, state
);
233 mark_sub_members_gone(name
, sym
, expr
, state
);
234 call_extra_mod_hooks(name
, sym
, expr
, state
);
235 call_update_mtag_data(expr
, state
);
236 if ((__in_fake_assign
|| in_param_set
) &&
237 estate_is_unknown(state
) && !get_state(SMATCH_EXTRA
, name
, sym
))
239 set_state(SMATCH_EXTRA
, name
, sym
, state
);
242 static void set_extra_nomod_helper(const char *name
, struct symbol
*sym
, struct expression
*expr
, struct smatch_state
*state
)
244 call_extra_nomod_hooks(name
, sym
, expr
, state
);
245 set_state(SMATCH_EXTRA
, name
, sym
, state
);
248 static char *get_pointed_at(const char *name
, struct symbol
*sym
, struct symbol
**new_sym
)
250 struct expression
*assigned
;
253 * Imagine we have an assignment: "foo = &addr;" then the other name
259 if (strcmp(name
+ 1, sym
->ident
->name
) != 0)
262 assigned
= get_assigned_expr_name_sym(sym
->ident
->name
, sym
);
265 assigned
= strip_parens(assigned
);
266 if (assigned
->type
!= EXPR_PREOP
|| assigned
->op
!= '&')
269 return expr_to_var_sym(assigned
->unop
, new_sym
);
272 char *get_other_name_sym_from_chunk(const char *name
, const char *chunk
, int len
, struct symbol
*sym
, struct symbol
**new_sym
)
274 struct expression
*assigned
;
275 char *orig_name
= NULL
;
279 assigned
= get_assigned_expr_name_sym(chunk
, sym
);
282 if (assigned
->type
== EXPR_CALL
)
283 return map_call_to_other_name_sym(name
, sym
, new_sym
);
284 if (assigned
->type
== EXPR_PREOP
&& assigned
->op
== '&') {
286 orig_name
= expr_to_var_sym(assigned
, new_sym
);
287 if (!orig_name
|| !*new_sym
)
290 snprintf(buf
, sizeof(buf
), "%s.%s", orig_name
+ 1, name
+ len
);
291 ret
= alloc_string(buf
);
292 free_string(orig_name
);
296 orig_name
= expr_to_var_sym(assigned
, new_sym
);
297 if (!orig_name
|| !*new_sym
)
300 snprintf(buf
, sizeof(buf
), "%s->%s", orig_name
, name
+ len
);
301 ret
= alloc_string(buf
);
302 free_string(orig_name
);
305 free_string(orig_name
);
309 static char *get_long_name_sym(const char *name
, struct symbol
*sym
, struct symbol
**new_sym
, bool use_stack
)
311 struct expression
*orig
;
312 struct symbol
*orig_sym
;
313 char *orig_name
, *ret
;
315 if (!sym
|| !sym
->ident
)
318 orig
= get_assigned_expr_name_sym(sym
->ident
->name
, sym
);
320 orig_name
= expr_to_var_sym(orig
, &orig_sym
);
324 ret
= swap_names(name
, sym
->ident
->name
, orig_name
);
325 free_string(orig_name
);
334 char *get_other_name_sym_helper(const char *name
, struct symbol
*sym
, struct symbol
**new_sym
, bool use_stack
)
342 if (!sym
|| !sym
->ident
)
345 ret
= get_pointed_at(name
, sym
, new_sym
);
349 ret
= map_long_to_short_name_sym(name
, sym
, new_sym
, use_stack
);
353 len
= snprintf(buf
, sizeof(buf
), "%s", name
);
354 if (len
>= sizeof(buf
) - 2)
357 while (use_stack
&& len
>= 1) {
358 if (buf
[len
] == '>' && buf
[len
- 1] == '-') {
361 ret
= get_other_name_sym_from_chunk(name
, buf
, len
+ 2, sym
, new_sym
);
368 ret
= get_long_name_sym(name
, sym
, new_sym
, use_stack
);
375 char *get_other_name_sym(const char *name
, struct symbol
*sym
, struct symbol
**new_sym
)
377 return get_other_name_sym_helper(name
, sym
, new_sym
, true);
380 char *get_other_name_sym_nostack(const char *name
, struct symbol
*sym
, struct symbol
**new_sym
)
382 return get_other_name_sym_helper(name
, sym
, new_sym
, false);
385 void set_extra_mod(const char *name
, struct symbol
*sym
, struct expression
*expr
, struct smatch_state
*state
)
388 struct symbol
*new_sym
;
390 set_extra_mod_helper(name
, sym
, expr
, state
);
391 new_name
= get_other_name_sym_nostack(name
, sym
, &new_sym
);
392 if (new_name
&& new_sym
)
393 set_extra_mod_helper(new_name
, new_sym
, NULL
, state
);
394 free_string(new_name
);
397 static struct expression
*chunk_get_array_base(struct expression
*expr
)
400 * The problem with is_array() is that it only returns true for things
401 * like foo[1] but not for foo[1].bar.
404 expr
= strip_expr(expr
);
405 while (expr
&& expr
->type
== EXPR_DEREF
)
406 expr
= strip_expr(expr
->deref
);
407 return get_array_base(expr
);
410 static int chunk_has_array(struct expression
*expr
)
412 return !!chunk_get_array_base(expr
);
415 static void clear_array_states(struct expression
*array
)
419 sm
= get_sm_state_expr(link_id
, array
);
421 match_link_modify(sm
, NULL
);
424 static void set_extra_array_mod(struct expression
*expr
, struct smatch_state
*state
)
426 struct expression
*array
;
427 struct var_sym_list
*vsl
;
432 array
= chunk_get_array_base(expr
);
434 name
= expr_to_chunk_sym_vsl(expr
, &sym
, &vsl
);
436 clear_array_states(array
);
440 FOR_EACH_PTR(vsl
, vs
) {
441 store_link(link_id
, vs
->var
, vs
->sym
, name
, sym
);
442 } END_FOR_EACH_PTR(vs
);
444 call_extra_mod_hooks(name
, sym
, expr
, state
);
445 set_state(SMATCH_EXTRA
, name
, sym
, state
);
450 void set_extra_expr_mod(struct expression
*expr
, struct smatch_state
*state
)
455 if (chunk_has_array(expr
)) {
456 set_extra_array_mod(expr
, state
);
460 expr
= strip_expr(expr
);
461 name
= expr_to_var_sym(expr
, &sym
);
464 set_extra_mod(name
, sym
, expr
, state
);
469 void set_extra_nomod(const char *name
, struct symbol
*sym
, struct expression
*expr
, struct smatch_state
*state
)
472 struct symbol
*new_sym
;
473 struct relation
*rel
;
474 struct smatch_state
*orig_state
;
476 orig_state
= get_state(SMATCH_EXTRA
, name
, sym
);
478 /* don't save unknown states if leaving it blank is the same */
479 if (!orig_state
&& estate_is_unknown(state
))
482 new_name
= get_other_name_sym(name
, sym
, &new_sym
);
483 if (new_name
&& new_sym
)
484 set_extra_nomod_helper(new_name
, new_sym
, expr
, state
);
485 free_string(new_name
);
487 if (!estate_related(orig_state
)) {
488 set_extra_nomod_helper(name
, sym
, expr
, state
);
492 set_related(state
, estate_related(orig_state
));
493 FOR_EACH_PTR(estate_related(orig_state
), rel
) {
494 struct smatch_state
*estate
;
496 estate
= get_state(SMATCH_EXTRA
, rel
->name
, rel
->sym
);
499 set_extra_nomod_helper(rel
->name
, rel
->sym
, expr
, clone_estate_cast(estate_type(estate
), state
));
500 } END_FOR_EACH_PTR(rel
);
503 void set_extra_nomod_vsl(const char *name
, struct symbol
*sym
, struct var_sym_list
*vsl
, struct expression
*expr
, struct smatch_state
*state
)
507 FOR_EACH_PTR(vsl
, vs
) {
508 store_link(link_id
, vs
->var
, vs
->sym
, name
, sym
);
509 } END_FOR_EACH_PTR(vs
);
511 set_extra_nomod(name
, sym
, expr
, state
);
515 * This is for return_implies_state() hooks which modify a SMATCH_EXTRA state
517 void set_extra_expr_nomod(struct expression
*expr
, struct smatch_state
*state
)
519 struct var_sym_list
*vsl
;
524 name
= expr_to_chunk_sym_vsl(expr
, &sym
, &vsl
);
527 FOR_EACH_PTR(vsl
, vs
) {
528 store_link(link_id
, vs
->var
, vs
->sym
, name
, sym
);
529 } END_FOR_EACH_PTR(vs
);
531 set_extra_nomod(name
, sym
, expr
, state
);
536 static void set_extra_true_false(const char *name
, struct symbol
*sym
,
537 struct smatch_state
*true_state
,
538 struct smatch_state
*false_state
)
541 struct symbol
*new_sym
;
542 struct relation
*rel
;
543 struct smatch_state
*orig_state
;
545 if (!true_state
&& !false_state
)
548 if (in_warn_on_macro())
551 new_name
= get_other_name_sym(name
, sym
, &new_sym
);
552 if (new_name
&& new_sym
)
553 set_true_false_states(SMATCH_EXTRA
, new_name
, new_sym
, true_state
, false_state
);
554 free_string(new_name
);
556 orig_state
= get_state(SMATCH_EXTRA
, name
, sym
);
558 if (!estate_related(orig_state
)) {
559 set_true_false_states(SMATCH_EXTRA
, name
, sym
, true_state
, false_state
);
564 set_related(true_state
, estate_related(orig_state
));
566 set_related(false_state
, estate_related(orig_state
));
568 FOR_EACH_PTR(estate_related(orig_state
), rel
) {
569 set_true_false_states(SMATCH_EXTRA
, rel
->name
, rel
->sym
,
570 true_state
, false_state
);
571 } END_FOR_EACH_PTR(rel
);
574 static void set_extra_chunk_true_false(struct expression
*expr
,
575 struct smatch_state
*true_state
,
576 struct smatch_state
*false_state
)
578 struct var_sym_list
*vsl
;
584 if (in_warn_on_macro())
587 type
= get_type(expr
);
591 name
= expr_to_chunk_sym_vsl(expr
, &sym
, &vsl
);
594 FOR_EACH_PTR(vsl
, vs
) {
595 store_link(link_id
, vs
->var
, vs
->sym
, name
, sym
);
596 } END_FOR_EACH_PTR(vs
);
598 set_true_false_states(SMATCH_EXTRA
, name
, sym
,
599 clone_estate(true_state
),
600 clone_estate(false_state
));
605 static void set_extra_expr_true_false(struct expression
*expr
,
606 struct smatch_state
*true_state
,
607 struct smatch_state
*false_state
)
613 if (!true_state
&& !false_state
)
616 if (get_value(expr
, &sval
))
619 expr
= strip_expr(expr
);
620 name
= expr_to_var_sym(expr
, &sym
);
623 set_extra_chunk_true_false(expr
, true_state
, false_state
);
626 set_extra_true_false(name
, sym
, true_state
, false_state
);
630 static int get_countdown_info(struct expression
*condition
, struct expression
**unop
, int *op
, sval_t
*right
)
632 struct expression
*unop_expr
;
636 right
->type
= &int_ctype
;
639 condition
= strip_expr(condition
);
641 if (condition
->type
== EXPR_COMPARE
) {
642 comparison
= remove_unsigned_from_comparison(condition
->op
);
644 if (comparison
!= SPECIAL_GTE
&& comparison
!= '>')
646 if (!get_value(condition
->right
, &limit
))
649 unop_expr
= condition
->left
;
650 if (unop_expr
->type
!= EXPR_PREOP
&& unop_expr
->type
!= EXPR_POSTOP
)
652 if (unop_expr
->op
!= SPECIAL_DECREMENT
)
662 if (condition
->type
!= EXPR_PREOP
&& condition
->type
!= EXPR_POSTOP
)
664 if (condition
->op
!= SPECIAL_DECREMENT
)
673 static struct sm_state
*handle_canonical_while_count_down(struct statement
*loop
)
675 struct expression
*iter_var
;
676 struct expression
*condition
, *unop
;
679 struct smatch_state
*estate
;
683 right
.type
= &int_ctype
;
686 condition
= strip_expr(loop
->iterator_pre_condition
);
690 if (!get_countdown_info(condition
, &unop
, &op
, &right
))
693 iter_var
= unop
->unop
;
695 sm
= get_sm_state_expr(SMATCH_EXTRA
, iter_var
);
698 if (sval_cmp(estate_min(sm
->state
), right
) < 0)
700 start
= estate_max(sm
->state
);
702 type
= get_type(iter_var
);
703 right
= sval_cast(type
, right
);
704 start
= sval_cast(type
, start
);
706 if (sval_cmp(start
, right
) <= 0)
708 if (!sval_is_max(start
))
711 if (op
== SPECIAL_GTE
)
714 if (unop
->type
== EXPR_PREOP
) {
716 estate
= alloc_estate_range(right
, start
);
717 if (estate_has_hard_max(sm
->state
))
718 estate_set_hard_max(estate
);
719 estate_copy_fuzzy_max(estate
, sm
->state
);
720 set_extra_expr_mod(iter_var
, estate
);
722 if (unop
->type
== EXPR_POSTOP
) {
723 estate
= alloc_estate_range(right
, start
);
724 if (estate_has_hard_max(sm
->state
))
725 estate_set_hard_max(estate
);
726 estate_copy_fuzzy_max(estate
, sm
->state
);
727 set_extra_expr_mod(iter_var
, estate
);
729 return get_sm_state_expr(SMATCH_EXTRA
, iter_var
);
732 static struct sm_state
*handle_canonical_for_inc(struct expression
*iter_expr
,
733 struct expression
*condition
)
735 struct expression
*iter_var
;
737 struct smatch_state
*estate
;
738 sval_t start
, end
, max
;
739 bool unknown_end
= false;
741 iter_var
= iter_expr
->unop
;
742 sm
= get_sm_state_expr(SMATCH_EXTRA
, iter_var
);
745 if (!estate_get_single_value(sm
->state
, &start
))
747 if (!get_implied_max(condition
->right
, &end
)) {
748 end
= sval_type_max(get_type(condition
->right
));
749 end
= sval_cast(start
.type
, end
);
750 if (sval_is_max(end
))
754 if (get_sm_state_expr(SMATCH_EXTRA
, condition
->left
) != sm
)
757 switch (condition
->op
) {
758 case SPECIAL_UNSIGNED_LT
:
759 case SPECIAL_NOTEQUAL
:
761 if (!sval_is_min(end
) && !unknown_end
)
764 case SPECIAL_UNSIGNED_LTE
:
770 if (sval_cmp(end
, start
) < 0)
772 end
= sval_cast(start
.type
, end
);
773 estate
= alloc_estate_range(start
, end
);
774 if (get_hard_max(condition
->right
, &max
)) {
775 if (!get_macro_name(condition
->pos
))
776 estate_set_hard_max(estate
);
777 if (condition
->op
== '<' ||
778 condition
->op
== SPECIAL_UNSIGNED_LT
||
779 condition
->op
== SPECIAL_NOTEQUAL
)
781 max
= sval_cast(start
.type
, max
);
782 estate_set_fuzzy_max(estate
, max
);
784 set_extra_expr_mod(iter_var
, estate
);
785 return get_sm_state_expr(SMATCH_EXTRA
, iter_var
);
788 static struct sm_state
*handle_canonical_for_dec(struct expression
*iter_expr
,
789 struct expression
*condition
)
791 struct expression
*iter_var
;
793 struct smatch_state
*estate
;
796 iter_var
= iter_expr
->unop
;
797 sm
= get_sm_state_expr(SMATCH_EXTRA
, iter_var
);
800 if (!estate_get_single_value(sm
->state
, &start
))
802 if (!get_implied_min(condition
->right
, &end
))
803 end
= sval_type_min(get_type(iter_var
));
804 end
= sval_cast(estate_type(sm
->state
), end
);
805 if (get_sm_state_expr(SMATCH_EXTRA
, condition
->left
) != sm
)
808 switch (condition
->op
) {
809 case SPECIAL_NOTEQUAL
:
811 if (!sval_is_max(end
))
819 if (sval_cmp(end
, start
) > 0)
821 estate
= alloc_estate_range(end
, start
);
822 estate_set_hard_max(estate
);
823 estate_set_fuzzy_max(estate
, estate_get_fuzzy_max(estate
));
824 set_extra_expr_mod(iter_var
, estate
);
825 return get_sm_state_expr(SMATCH_EXTRA
, iter_var
);
828 static struct sm_state
*handle_canonical_for_loops(struct statement
*loop
)
830 struct expression
*iter_expr
;
831 struct expression
*condition
;
833 if (!loop
->iterator_post_statement
)
835 if (loop
->iterator_post_statement
->type
!= STMT_EXPRESSION
)
837 iter_expr
= loop
->iterator_post_statement
->expression
;
838 if (!loop
->iterator_pre_condition
)
840 if (loop
->iterator_pre_condition
->type
!= EXPR_COMPARE
)
842 condition
= loop
->iterator_pre_condition
;
844 if (iter_expr
->op
== SPECIAL_INCREMENT
)
845 return handle_canonical_for_inc(iter_expr
, condition
);
846 if (iter_expr
->op
== SPECIAL_DECREMENT
)
847 return handle_canonical_for_dec(iter_expr
, condition
);
851 struct sm_state
*__extra_handle_canonical_loops(struct statement
*loop
, struct stree
**stree
)
853 struct sm_state
*ret
;
856 * Canonical loops are a hack. The proper way to handle this is to
857 * use two passes, but unfortunately, doing two passes makes parsing
858 * code twice as slow.
860 * What we do is we set the inside state here, which overwrites whatever
861 * __extra_match_condition() does. Then we set the outside state in
862 * __extra_pre_loop_hook_after().
865 __push_fake_cur_stree();
866 if (!loop
->iterator_post_statement
)
867 ret
= handle_canonical_while_count_down(loop
);
869 ret
= handle_canonical_for_loops(loop
);
870 *stree
= __pop_fake_cur_stree();
874 int __iterator_unchanged(struct sm_state
*sm
)
878 if (get_sm_state(my_id
, sm
->name
, sm
->sym
) == sm
)
883 static void while_count_down_after(struct sm_state
*sm
, struct expression
*condition
)
885 struct expression
*unop
;
887 sval_t limit
, after_value
;
889 if (!get_countdown_info(condition
, &unop
, &op
, &limit
))
891 after_value
= estate_min(sm
->state
);
893 set_extra_mod(sm
->name
, sm
->sym
, condition
->unop
, alloc_estate_sval(after_value
));
896 void __extra_pre_loop_hook_after(struct sm_state
*sm
,
897 struct statement
*iterator
,
898 struct expression
*condition
)
900 struct expression
*iter_expr
;
902 struct smatch_state
*state
;
906 while_count_down_after(sm
, condition
);
910 iter_expr
= iterator
->expression
;
912 if (condition
->type
!= EXPR_COMPARE
)
915 if (iter_expr
->op
== SPECIAL_INCREMENT
) {
916 if (!get_implied_value(condition
->right
, &end
) &&
917 sval_is_max(estate_max(sm
->state
)))
918 limit
= estate_max(sm
->state
);
920 limit
= sval_binop(estate_max(sm
->state
), '+',
921 sval_type_val(estate_type(sm
->state
), 1));
923 limit
= sval_binop(estate_min(sm
->state
), '-',
924 sval_type_val(estate_type(sm
->state
), 1));
926 limit
= sval_cast(estate_type(sm
->state
), limit
);
927 if (!estate_has_hard_max(sm
->state
) && !__has_breaks()) {
928 if (iter_expr
->op
== SPECIAL_INCREMENT
)
929 state
= alloc_estate_range(estate_min(sm
->state
), limit
);
931 state
= alloc_estate_range(limit
, estate_max(sm
->state
));
933 state
= alloc_estate_sval(limit
);
935 if (!estate_has_hard_max(sm
->state
)) {
936 estate_clear_hard_max(state
);
938 if (estate_has_fuzzy_max(sm
->state
)) {
939 sval_t hmax
= estate_get_fuzzy_max(sm
->state
);
940 sval_t max
= estate_max(sm
->state
);
942 if (sval_cmp(hmax
, max
) != 0)
943 estate_clear_fuzzy_max(state
);
944 } else if (!estate_has_fuzzy_max(sm
->state
)) {
945 estate_clear_fuzzy_max(state
);
948 set_extra_mod(sm
->name
, sm
->sym
, iter_expr
, state
);
951 static bool get_global_rl(const char *name
, struct symbol
*sym
, struct range_list
**rl
)
953 struct expression
*expr
;
955 if (!sym
|| !(sym
->ctype
.modifiers
& MOD_TOPLEVEL
) || !sym
->ident
)
957 if (strcmp(sym
->ident
->name
, name
) != 0)
960 expr
= symbol_expression(sym
);
961 return get_implied_rl(expr
, rl
);
964 static struct stree
*unmatched_stree
;
965 static struct smatch_state
*unmatched_state(struct sm_state
*sm
)
967 struct smatch_state
*state
;
968 struct expression
*expr
;
969 struct range_list
*rl
;
971 if (unmatched_stree
) {
972 state
= get_state_stree(unmatched_stree
, SMATCH_EXTRA
, sm
->name
, sm
->sym
);
976 if (parent_is_gone_var_sym(sm
->name
, sm
->sym
))
977 return alloc_estate_empty();
978 if (get_global_rl(sm
->name
, sm
->sym
, &rl
))
979 return alloc_estate_rl(rl
);
981 expr
= gen_expression_from_name_sym(sm
->name
, sm
->sym
);
983 return alloc_estate_whole(estate_type(sm
->state
));
984 get_absolute_rl(expr
, &rl
);
985 return alloc_estate_rl(rl
);
988 static void clear_the_pointed_at(struct expression
*expr
)
993 struct sm_state
*tmp
;
995 name
= expr_to_var_sym(expr
, &sym
);
999 stree
= __get_cur_stree();
1000 FOR_EACH_MY_SM(SMATCH_EXTRA
, stree
, tmp
) {
1001 if (tmp
->name
[0] != '*')
1003 if (tmp
->sym
!= sym
)
1005 if (strcmp(tmp
->name
+ 1, name
) != 0)
1007 set_extra_mod(tmp
->name
, tmp
->sym
, expr
, alloc_estate_whole(estate_type(tmp
->state
)));
1008 } END_FOR_EACH_SM(tmp
);
1014 static int is_const_param(struct expression
*expr
, int param
)
1016 struct symbol
*type
;
1018 type
= get_arg_type(expr
, param
);
1021 if (type
->ctype
.modifiers
& MOD_CONST
)
1026 static void match_function_call(struct expression
*expr
)
1028 struct expression
*arg
;
1029 struct expression
*tmp
;
1032 /* if we have the db this is handled in smatch_function_hooks.c */
1035 if (inlinable(expr
->fn
))
1038 FOR_EACH_PTR(expr
->args
, arg
) {
1040 if (is_const_param(expr
->fn
, param
))
1042 tmp
= strip_expr(arg
);
1043 if (tmp
->type
== EXPR_PREOP
&& tmp
->op
== '&')
1044 set_extra_expr_mod(tmp
->unop
, alloc_estate_whole(get_type(tmp
->unop
)));
1046 clear_the_pointed_at(tmp
);
1047 } END_FOR_EACH_PTR(arg
);
1050 int values_fit_type(struct expression
*left
, struct expression
*right
)
1052 struct range_list
*rl
;
1053 struct symbol
*type
;
1055 type
= get_type(left
);
1058 get_absolute_rl(right
, &rl
);
1059 if (type
== rl_type(rl
))
1061 if (sval_is_negative(rl_min(rl
))) {
1062 if (type_unsigned(type
))
1064 if (sval_cmp(sval_type_min(type
), rl_min(rl
)) > 0)
1067 if (sval_cmp(sval_type_max(type
), rl_max(rl
)) < 0)
1072 static void save_chunk_info(struct expression
*left
, struct expression
*right
)
1074 struct var_sym_list
*vsl
;
1076 struct expression
*add_expr
;
1077 struct symbol
*type
;
1082 if (right
->type
!= EXPR_BINOP
|| right
->op
!= '-')
1084 if (!get_value(right
->left
, &sval
))
1086 if (!expr_to_sym(right
->right
))
1089 add_expr
= binop_expression(left
, '+', right
->right
);
1090 type
= get_type(add_expr
);
1093 name
= expr_to_chunk_sym_vsl(add_expr
, &sym
, &vsl
);
1096 FOR_EACH_PTR(vsl
, vs
) {
1097 store_link(link_id
, vs
->var
, vs
->sym
, name
, sym
);
1098 } END_FOR_EACH_PTR(vs
);
1100 set_state(SMATCH_EXTRA
, name
, sym
, alloc_estate_sval(sval_cast(type
, sval
)));
1105 static void do_array_assign(struct expression
*left
, int op
, struct expression
*right
)
1107 struct range_list
*rl
;
1110 get_absolute_rl(right
, &rl
);
1111 rl
= cast_rl(get_type(left
), rl
);
1113 rl
= alloc_whole_rl(get_type(left
));
1116 set_extra_array_mod(left
, alloc_estate_rl(rl
));
1119 static void match_vanilla_assign(struct expression
*left
, struct expression
*right
)
1121 struct range_list
*orig_rl
= NULL
;
1122 struct range_list
*rl
= NULL
;
1123 struct symbol
*right_sym
;
1124 struct symbol
*left_type
;
1125 struct symbol
*right_type
;
1126 char *right_name
= NULL
;
1130 struct smatch_state
*state
;
1133 if (is_struct(left
))
1136 if (expr_equiv(left
, right
))
1139 save_chunk_info(left
, right
);
1141 name
= expr_to_var_sym(left
, &sym
);
1143 if (chunk_has_array(left
))
1144 do_array_assign(left
, '=', right
);
1148 left_type
= get_type(left
);
1149 right_type
= get_type(right
);
1151 right_name
= expr_to_var_sym(right
, &right_sym
);
1153 if (!__in_fake_assign
&&
1154 !(right
->type
== EXPR_PREOP
&& right
->op
== '&') &&
1155 right_name
&& right_sym
&&
1156 values_fit_type(left
, strip_expr(right
)) &&
1157 !has_symbol(right
, sym
)) {
1158 set_equiv(left
, right
);
1162 if (get_implied_value(right
, &sval
)) {
1163 state
= alloc_estate_sval(sval_cast(left_type
, sval
));
1167 if (__in_fake_assign
|| is_fake_var(left
)) {
1168 struct smatch_state
*right_state
;
1169 struct range_list
*rl
;
1171 right_state
= get_state(SMATCH_EXTRA
, right_name
, right_sym
);
1173 state
= clone_estate_cast(left_type
, right_state
);
1177 if (get_implied_rl(right
, &rl
)) {
1178 rl
= cast_rl(left_type
, rl
);
1179 state
= alloc_estate_rl(rl
);
1183 rl
= alloc_whole_rl(right_type
);
1184 rl
= cast_rl(left_type
, rl
);
1185 state
= alloc_estate_rl(rl
);
1189 comparison
= get_comparison_no_extra(left
, right
);
1191 comparison
= flip_comparison(comparison
);
1192 get_implied_rl(left
, &orig_rl
);
1195 if (get_implied_rl(right
, &rl
)) {
1196 rl
= cast_rl(left_type
, rl
);
1198 filter_by_comparison(&rl
, comparison
, orig_rl
);
1199 state
= alloc_estate_rl(rl
);
1200 if (get_hard_max(right
, &max
)) {
1201 estate_set_hard_max(state
);
1202 estate_set_fuzzy_max(state
, max
);
1205 rl
= alloc_whole_rl(right_type
);
1206 rl
= cast_rl(left_type
, rl
);
1208 filter_by_comparison(&rl
, comparison
, orig_rl
);
1209 state
= alloc_estate_rl(rl
);
1213 set_extra_mod(name
, sym
, left
, state
);
1215 free_string(right_name
);
1218 static void match_assign(struct expression
*expr
)
1220 struct range_list
*rl
= NULL
;
1221 struct expression
*left
;
1222 struct expression
*right
;
1223 struct expression
*binop_expr
;
1224 struct symbol
*left_type
;
1228 left
= strip_expr(expr
->left
);
1230 right
= strip_parens(expr
->right
);
1231 if (right
->type
== EXPR_CALL
&& sym_name_is("__builtin_expect", right
->fn
))
1232 right
= get_argument_from_call_expr(right
->args
, 0);
1233 while (right
->type
== EXPR_ASSIGNMENT
&& right
->op
== '=')
1234 right
= strip_parens(right
->left
);
1236 if (expr
->op
== '=' && is_condition(expr
->right
))
1237 return; /* handled in smatch_condition.c */
1238 if (expr
->op
== '=' && right
->type
== EXPR_CALL
&&
1239 !is_fake_call(right
))
1240 return; /* handled in smatch_function_hooks.c */
1241 if (expr
->op
== '=') {
1242 match_vanilla_assign(left
, right
);
1246 name
= expr_to_var_sym(left
, &sym
);
1250 left_type
= get_type(left
);
1253 case SPECIAL_ADD_ASSIGN
:
1254 case SPECIAL_SUB_ASSIGN
:
1255 case SPECIAL_AND_ASSIGN
:
1256 case SPECIAL_MOD_ASSIGN
:
1257 case SPECIAL_SHL_ASSIGN
:
1258 case SPECIAL_SHR_ASSIGN
:
1259 case SPECIAL_OR_ASSIGN
:
1260 case SPECIAL_XOR_ASSIGN
:
1261 case SPECIAL_MUL_ASSIGN
:
1262 case SPECIAL_DIV_ASSIGN
:
1263 binop_expr
= binop_expression(expr
->left
,
1264 op_remove_assign(expr
->op
),
1266 get_absolute_rl(binop_expr
, &rl
);
1267 rl
= cast_rl(left_type
, rl
);
1268 if (inside_loop()) {
1269 if (expr
->op
== SPECIAL_ADD_ASSIGN
)
1270 add_range(&rl
, rl_max(rl
), sval_type_max(rl_type(rl
)));
1272 if (expr
->op
== SPECIAL_SUB_ASSIGN
&&
1273 !sval_is_negative(rl_min(rl
))) {
1274 sval_t zero
= { .type
= rl_type(rl
) };
1276 add_range(&rl
, rl_min(rl
), zero
);
1279 set_extra_mod(name
, sym
, left
, alloc_estate_rl(rl
));
1282 set_extra_mod(name
, sym
, left
, alloc_estate_whole(left_type
));
1287 static struct smatch_state
*increment_state(struct smatch_state
*state
)
1289 sval_t min
= estate_min(state
);
1290 sval_t max
= estate_max(state
);
1292 if (!estate_rl(state
))
1296 max
= sval_type_max(max
.type
);
1298 if (!sval_is_min(min
) && !sval_is_max(min
))
1300 if (!sval_is_min(max
) && !sval_is_max(max
))
1302 return alloc_estate_range(min
, max
);
1305 static struct smatch_state
*decrement_state(struct smatch_state
*state
)
1307 sval_t min
= estate_min(state
);
1308 sval_t max
= estate_max(state
);
1310 if (!estate_rl(state
))
1314 min
= sval_type_min(min
.type
);
1316 if (!sval_is_min(min
) && !sval_is_max(min
))
1318 if (!sval_is_min(max
) && !sval_is_max(max
))
1320 return alloc_estate_range(min
, max
);
1323 static void clear_pointed_at_state(struct expression
*expr
)
1325 struct symbol
*type
;
1328 * ALERT: This is sort of a mess. If it's is a struct assigment like
1329 * "foo = bar;", then that's handled by smatch_struct_assignment.c.
1330 * the same thing for p++ where "p" is a struct. Most modifications
1331 * are handled by the assignment hook or the db. Smatch_extra.c doesn't
1332 * use smatch_modification.c because we have to get the ordering right
1333 * or something. So if you have p++ where p is a pointer to a standard
1334 * c type then we handle that here. What a mess.
1336 expr
= strip_expr(expr
);
1337 type
= get_type(expr
);
1338 if (!type
|| type
->type
!= SYM_PTR
)
1340 type
= get_real_base_type(type
);
1341 if (!type
|| type
->type
!= SYM_BASETYPE
)
1343 set_extra_expr_nomod(deref_expression(expr
), alloc_estate_whole(type
));
1346 static void unop_expr(struct expression
*expr
)
1348 struct smatch_state
*state
;
1350 if (expr
->smatch_flags
& Handled
)
1354 case SPECIAL_INCREMENT
:
1355 state
= get_state_expr(SMATCH_EXTRA
, expr
->unop
);
1356 state
= increment_state(state
);
1358 state
= alloc_estate_whole(get_type(expr
));
1359 set_extra_expr_mod(expr
->unop
, state
);
1360 clear_pointed_at_state(expr
->unop
);
1362 case SPECIAL_DECREMENT
:
1363 state
= get_state_expr(SMATCH_EXTRA
, expr
->unop
);
1364 state
= decrement_state(state
);
1366 state
= alloc_estate_whole(get_type(expr
));
1367 set_extra_expr_mod(expr
->unop
, state
);
1368 clear_pointed_at_state(expr
->unop
);
1375 static void asm_expr(struct statement
*stmt
)
1377 struct asm_operand
*op
;
1378 struct symbol
*type
;
1380 FOR_EACH_PTR(stmt
->asm_outputs
, op
) {
1381 type
= get_type(strip_expr(op
->expr
));
1382 set_extra_expr_mod(op
->expr
, alloc_estate_whole(type
));
1383 } END_FOR_EACH_PTR(op
);
1386 static void check_dereference(struct expression
*expr
)
1388 struct smatch_state
*state
;
1390 if (__in_fake_assign
)
1392 if (outside_of_function())
1394 state
= get_extra_state(expr
);
1396 struct range_list
*rl
;
1398 rl
= rl_intersection(estate_rl(state
), valid_ptr_rl
);
1399 if (rl_equiv(rl
, estate_rl(state
)))
1401 set_extra_expr_nomod(expr
, alloc_estate_rl(rl
));
1403 struct range_list
*rl
;
1405 if (get_mtag_rl(expr
, &rl
))
1406 rl
= rl_intersection(rl
, valid_ptr_rl
);
1408 rl
= clone_rl(valid_ptr_rl
);
1411 set_extra_expr_nomod(expr
, alloc_estate_rl(rl
));
1416 static void match_dereferences(struct expression
*expr
)
1418 if (expr
->type
!= EXPR_PREOP
)
1420 if (getting_address(expr
))
1422 /* it's saying that foo[1] = bar dereferences foo[1] */
1425 check_dereference(expr
->unop
);
1428 static void match_pointer_as_array(struct expression
*expr
)
1430 if (!is_array(expr
))
1432 check_dereference(get_array_base(expr
));
1435 static void find_dereferences(struct expression
*expr
)
1437 while (expr
->type
== EXPR_PREOP
) {
1438 if (expr
->op
== '*')
1439 check_dereference(expr
->unop
);
1440 expr
= strip_expr(expr
->unop
);
1444 static void set_param_dereferenced(struct expression
*call
, struct expression
*arg
, char *key
, char *unused
)
1449 if (strcmp(key
, "$") == 0 && arg
->type
== EXPR_PREOP
&& arg
->op
== '&') {
1450 struct expression
*tmp
;
1452 tmp
= strip_expr(arg
->unop
);
1453 if (tmp
->type
== EXPR_DEREF
) {
1454 tmp
= strip_expr(tmp
->deref
);
1455 if (tmp
->type
== EXPR_PREOP
&& tmp
->op
== '*')
1456 arg
= strip_expr(tmp
->unop
);
1460 name
= get_variable_from_key(arg
, key
, &sym
);
1462 struct smatch_state
*orig
, *new;
1463 struct range_list
*rl
;
1465 orig
= get_state(SMATCH_EXTRA
, name
, sym
);
1467 rl
= rl_intersection(estate_rl(orig
),
1468 alloc_rl(valid_ptr_min_sval
,
1469 valid_ptr_max_sval
));
1470 new = alloc_estate_rl(rl
);
1472 new = alloc_estate_range(valid_ptr_min_sval
, valid_ptr_max_sval
);
1477 set_extra_nomod(name
, sym
, NULL
, new);
1483 find_dereferences(arg
);
1486 static sval_t
add_one(sval_t sval
)
1492 static int handle_postop_inc(struct expression
*left
, int op
, struct expression
*right
)
1494 struct statement
*stmt
;
1495 struct expression
*cond
;
1496 struct smatch_state
*true_state
, *false_state
;
1497 struct symbol
*type
;
1502 * If we're decrementing here then that's a canonical while count down
1503 * so it's handled already. We're only handling loops like:
1505 * do { ... } while (i++ < 3);
1508 if (left
->type
!= EXPR_POSTOP
|| left
->op
!= SPECIAL_INCREMENT
)
1511 stmt
= __cur_stmt
->parent
;
1514 if (stmt
->type
== STMT_COMPOUND
)
1515 stmt
= stmt
->parent
;
1516 if (!stmt
|| stmt
->type
!= STMT_ITERATOR
|| !stmt
->iterator_post_condition
)
1519 cond
= strip_expr(stmt
->iterator_post_condition
);
1520 if (cond
->type
!= EXPR_COMPARE
|| cond
->op
!= op
)
1522 if (left
!= strip_expr(cond
->left
) || right
!= strip_expr(cond
->right
))
1525 if (!get_implied_value(left
->unop
, &start
))
1527 if (!get_implied_value(right
, &limit
))
1529 type
= get_type(left
->unop
);
1530 limit
= sval_cast(type
, limit
);
1531 if (sval_cmp(start
, limit
) > 0)
1536 case SPECIAL_UNSIGNED_LT
:
1539 case SPECIAL_UNSIGNED_LTE
:
1540 limit
= add_one(limit
);
1546 true_state
= alloc_estate_range(add_one(start
), limit
);
1547 false_state
= alloc_estate_range(add_one(limit
), add_one(limit
));
1549 /* Currently we just discard the false state but when two passes is
1550 * implimented correctly then it will use it.
1553 set_extra_expr_true_false(left
->unop
, true_state
, false_state
);
1558 bool is_impossible_variable(struct expression
*expr
)
1560 struct smatch_state
*state
;
1562 state
= get_extra_state(expr
);
1563 if (state
&& !estate_rl(state
))
1568 static bool in_macro(struct expression
*left
, struct expression
*right
)
1570 if (!left
|| !right
)
1572 if (left
->pos
.line
!= right
->pos
.line
|| left
->pos
.pos
!= right
->pos
.pos
)
1574 if (get_macro_name(left
->pos
))
1579 static void handle_comparison(struct symbol
*type
, struct expression
*left
, int op
, struct expression
*right
)
1581 struct smatch_state
*left_state_orig
, *right_state_orig
;
1582 struct range_list
*left_orig
;
1583 struct range_list
*left_true
;
1584 struct range_list
*left_false
;
1585 struct range_list
*right_orig
;
1586 struct range_list
*right_true
;
1587 struct range_list
*right_false
;
1588 struct smatch_state
*left_true_state
;
1589 struct smatch_state
*left_false_state
;
1590 struct smatch_state
*right_true_state
;
1591 struct smatch_state
*right_false_state
;
1592 sval_t dummy
, hard_max
;
1593 int left_postop
= 0;
1594 int right_postop
= 0;
1596 if (left
->op
== SPECIAL_INCREMENT
|| left
->op
== SPECIAL_DECREMENT
) {
1597 if (left
->type
== EXPR_POSTOP
) {
1598 left
->smatch_flags
|= Handled
;
1599 left_postop
= left
->op
;
1600 if (handle_postop_inc(left
, op
, right
))
1603 left
= strip_parens(left
->unop
);
1605 while (left
->type
== EXPR_ASSIGNMENT
)
1606 left
= strip_parens(left
->left
);
1608 if (right
->op
== SPECIAL_INCREMENT
|| right
->op
== SPECIAL_DECREMENT
) {
1609 if (right
->type
== EXPR_POSTOP
) {
1610 right
->smatch_flags
|= Handled
;
1611 right_postop
= right
->op
;
1613 right
= strip_parens(right
->unop
);
1616 if (is_impossible_variable(left
) || is_impossible_variable(right
))
1619 left_state_orig
= get_extra_state(left
);
1620 get_real_absolute_rl(left
, &left_orig
);
1621 left_orig
= cast_rl(type
, left_orig
);
1623 right_state_orig
= get_extra_state(right
);
1624 get_real_absolute_rl(right
, &right_orig
);
1625 right_orig
= cast_rl(type
, right_orig
);
1627 split_comparison_rl(left_orig
, op
, right_orig
, &left_true
, &left_false
, &right_true
, &right_false
);
1629 left_true
= rl_truncate_cast(get_type(strip_expr(left
)), left_true
);
1630 left_false
= rl_truncate_cast(get_type(strip_expr(left
)), left_false
);
1631 right_true
= rl_truncate_cast(get_type(strip_expr(right
)), right_true
);
1632 right_false
= rl_truncate_cast(get_type(strip_expr(right
)), right_false
);
1634 if (!left_true
|| !left_false
) {
1635 struct range_list
*tmp_true
, *tmp_false
;
1637 split_comparison_rl(alloc_whole_rl(type
), op
, right_orig
, &tmp_true
, &tmp_false
, NULL
, NULL
);
1638 tmp_true
= rl_truncate_cast(get_type(strip_expr(left
)), tmp_true
);
1639 tmp_false
= rl_truncate_cast(get_type(strip_expr(left
)), tmp_false
);
1640 if (tmp_true
&& tmp_false
)
1641 __save_imaginary_state(left
, tmp_true
, tmp_false
);
1644 if (!right_true
|| !right_false
) {
1645 struct range_list
*tmp_true
, *tmp_false
;
1647 split_comparison_rl(alloc_whole_rl(type
), op
, right_orig
, NULL
, NULL
, &tmp_true
, &tmp_false
);
1648 tmp_true
= rl_truncate_cast(get_type(strip_expr(right
)), tmp_true
);
1649 tmp_false
= rl_truncate_cast(get_type(strip_expr(right
)), tmp_false
);
1650 if (tmp_true
&& tmp_false
)
1651 __save_imaginary_state(right
, tmp_true
, tmp_false
);
1654 left_true_state
= alloc_estate_rl(left_true
);
1655 left_false_state
= alloc_estate_rl(left_false
);
1656 right_true_state
= alloc_estate_rl(right_true
);
1657 right_false_state
= alloc_estate_rl(right_false
);
1661 case SPECIAL_UNSIGNED_LT
:
1662 case SPECIAL_UNSIGNED_LTE
:
1664 if (get_hard_max(right
, &dummy
) && !in_macro(left
, right
))
1665 estate_set_hard_max(left_true_state
);
1666 if (get_hard_max(left
, &dummy
) && !in_macro(left
, right
))
1667 estate_set_hard_max(right_false_state
);
1670 case SPECIAL_UNSIGNED_GT
:
1671 case SPECIAL_UNSIGNED_GTE
:
1673 if (get_hard_max(left
, &dummy
) && !in_macro(left
, right
))
1674 estate_set_hard_max(right_true_state
);
1675 if (get_hard_max(right
, &dummy
) && !in_macro(left
, right
))
1676 estate_set_hard_max(left_false_state
);
1682 case SPECIAL_UNSIGNED_LT
:
1683 case SPECIAL_UNSIGNED_LTE
:
1685 if (get_hard_max(right
, &hard_max
)) {
1686 if (op
== '<' || op
== SPECIAL_UNSIGNED_LT
)
1688 estate_set_fuzzy_max(left_true_state
, hard_max
);
1690 if (get_implied_value(right
, &hard_max
)) {
1691 if (op
== SPECIAL_UNSIGNED_LTE
||
1694 estate_set_fuzzy_max(left_false_state
, hard_max
);
1696 if (get_hard_max(left
, &hard_max
)) {
1697 if (op
== SPECIAL_UNSIGNED_LTE
||
1700 estate_set_fuzzy_max(right_false_state
, hard_max
);
1702 if (get_implied_value(left
, &hard_max
)) {
1703 if (op
== '<' || op
== SPECIAL_UNSIGNED_LT
)
1705 estate_set_fuzzy_max(right_true_state
, hard_max
);
1709 case SPECIAL_UNSIGNED_GT
:
1710 case SPECIAL_UNSIGNED_GTE
:
1712 if (get_hard_max(left
, &hard_max
)) {
1713 if (op
== '>' || op
== SPECIAL_UNSIGNED_GT
)
1715 estate_set_fuzzy_max(right_true_state
, hard_max
);
1717 if (get_implied_value(left
, &hard_max
)) {
1718 if (op
== SPECIAL_UNSIGNED_GTE
||
1721 estate_set_fuzzy_max(right_false_state
, hard_max
);
1723 if (get_hard_max(right
, &hard_max
)) {
1724 if (op
== SPECIAL_UNSIGNED_LTE
||
1727 estate_set_fuzzy_max(left_false_state
, hard_max
);
1729 if (get_implied_value(right
, &hard_max
)) {
1731 op
== SPECIAL_UNSIGNED_GT
)
1733 estate_set_fuzzy_max(left_true_state
, hard_max
);
1737 if (get_hard_max(left
, &hard_max
))
1738 estate_set_fuzzy_max(right_true_state
, hard_max
);
1739 if (get_hard_max(right
, &hard_max
))
1740 estate_set_fuzzy_max(left_true_state
, hard_max
);
1744 if (get_hard_max(left
, &hard_max
)) {
1745 estate_set_hard_max(left_true_state
);
1746 estate_set_hard_max(left_false_state
);
1748 if (get_hard_max(right
, &hard_max
)) {
1749 estate_set_hard_max(right_true_state
);
1750 estate_set_hard_max(right_false_state
);
1753 if (left_postop
== SPECIAL_INCREMENT
) {
1754 left_true_state
= increment_state(left_true_state
);
1755 left_false_state
= increment_state(left_false_state
);
1757 if (left_postop
== SPECIAL_DECREMENT
) {
1758 left_true_state
= decrement_state(left_true_state
);
1759 left_false_state
= decrement_state(left_false_state
);
1761 if (right_postop
== SPECIAL_INCREMENT
) {
1762 right_true_state
= increment_state(right_true_state
);
1763 right_false_state
= increment_state(right_false_state
);
1765 if (right_postop
== SPECIAL_DECREMENT
) {
1766 right_true_state
= decrement_state(right_true_state
);
1767 right_false_state
= decrement_state(right_false_state
);
1770 if (estate_rl(left_true_state
) && estates_equiv(left_true_state
, left_false_state
)) {
1771 left_true_state
= NULL
;
1772 left_false_state
= NULL
;
1775 if (estate_rl(right_true_state
) && estates_equiv(right_true_state
, right_false_state
)) {
1776 right_true_state
= NULL
;
1777 right_false_state
= NULL
;
1780 /* Don't introduce new states for known true/false conditions */
1781 if (rl_equiv(estate_rl(left_state_orig
), estate_rl(left_true_state
)))
1782 left_true_state
= NULL
;
1783 if (rl_equiv(estate_rl(left_state_orig
), estate_rl(left_false_state
)))
1784 left_false_state
= NULL
;
1785 if (rl_equiv(estate_rl(right_state_orig
), estate_rl(right_true_state
)))
1786 right_true_state
= NULL
;
1787 if (rl_equiv(estate_rl(right_state_orig
), estate_rl(right_false_state
)))
1788 right_false_state
= NULL
;
1790 set_extra_expr_true_false(left
, left_true_state
, left_false_state
);
1791 set_extra_expr_true_false(right
, right_true_state
, right_false_state
);
1794 static int is_simple_math(struct expression
*expr
)
1798 if (expr
->type
!= EXPR_BINOP
)
1809 static int flip_op(int op
)
1811 /* We only care about simple math */
1823 static void move_known_to_rl(struct expression
**expr_p
, struct range_list
**rl_p
)
1825 struct expression
*expr
= *expr_p
;
1826 struct range_list
*rl
= *rl_p
;
1829 if (!is_simple_math(expr
))
1832 if (get_implied_value(expr
->right
, &sval
)) {
1833 *expr_p
= expr
->left
;
1834 *rl_p
= rl_binop(rl
, flip_op(expr
->op
), alloc_rl(sval
, sval
));
1835 move_known_to_rl(expr_p
, rl_p
);
1838 if (expr
->op
== '-')
1840 if (get_implied_value(expr
->left
, &sval
)) {
1841 *expr_p
= expr
->right
;
1842 *rl_p
= rl_binop(rl
, flip_op(expr
->op
), alloc_rl(sval
, sval
));
1843 move_known_to_rl(expr_p
, rl_p
);
1848 static void move_known_values(struct expression
**left_p
, struct expression
**right_p
)
1850 struct expression
*left
= *left_p
;
1851 struct expression
*right
= *right_p
;
1854 if (get_implied_value(left
, &sval
)) {
1855 if (!is_simple_math(right
))
1857 if (get_implied_value(right
, &dummy
))
1859 if (right
->op
== '*') {
1862 if (!get_value(right
->right
, &divisor
))
1864 if (divisor
.value
== 0)
1866 *left_p
= binop_expression(left
, invert_op(right
->op
), right
->right
);
1867 *right_p
= right
->left
;
1870 if (right
->op
== '+' && get_value(right
->left
, &sval
)) {
1871 *left_p
= binop_expression(left
, invert_op(right
->op
), right
->left
);
1872 *right_p
= right
->right
;
1875 if (get_value(right
->right
, &sval
)) {
1876 *left_p
= binop_expression(left
, invert_op(right
->op
), right
->right
);
1877 *right_p
= right
->left
;
1882 if (get_implied_value(right
, &sval
)) {
1883 if (!is_simple_math(left
))
1885 if (get_implied_value(left
, &dummy
))
1887 if (left
->op
== '*') {
1890 if (!get_value(left
->right
, &divisor
))
1892 if (divisor
.value
== 0)
1894 *right_p
= binop_expression(right
, invert_op(left
->op
), left
->right
);
1895 *left_p
= left
->left
;
1898 if (left
->op
== '+' && get_value(left
->left
, &sval
)) {
1899 *right_p
= binop_expression(right
, invert_op(left
->op
), left
->left
);
1900 *left_p
= left
->right
;
1904 if (get_value(left
->right
, &sval
)) {
1905 *right_p
= binop_expression(right
, invert_op(left
->op
), left
->right
);
1906 *left_p
= left
->left
;
1914 * The reason for do_simple_algebra() is to solve things like:
1915 * if (foo > 66 || foo + bar > 64) {
1916 * "foo" is not really a known variable so it won't be handled by
1917 * move_known_variables() but it's a super common idiom.
1920 static int do_simple_algebra(struct expression
**left_p
, struct expression
**right_p
)
1922 struct expression
*left
= *left_p
;
1923 struct expression
*right
= *right_p
;
1924 struct range_list
*rl
;
1927 if (left
->type
!= EXPR_BINOP
|| left
->op
!= '+')
1929 if (can_integer_overflow(get_type(left
), left
))
1931 if (!get_implied_value(right
, &tmp
))
1934 if (!get_implied_value(left
->left
, &tmp
) &&
1935 get_implied_rl(left
->left
, &rl
) &&
1937 *right_p
= binop_expression(right
, '-', left
->left
);
1938 *left_p
= left
->right
;
1941 if (!get_implied_value(left
->right
, &tmp
) &&
1942 get_implied_rl(left
->right
, &rl
) &&
1944 *right_p
= binop_expression(right
, '-', left
->right
);
1945 *left_p
= left
->left
;
1952 static int match_func_comparison(struct expression
*expr
)
1954 struct expression
*left
= strip_expr(expr
->left
);
1955 struct expression
*right
= strip_expr(expr
->right
);
1957 if (left
->type
== EXPR_CALL
|| right
->type
== EXPR_CALL
) {
1958 // TODO: faked_assign this should be handled as a fake assignment instead
1959 function_comparison(left
, expr
->op
, right
);
1966 /* Handle conditions like "if (foo + bar < foo) {" */
1967 static int handle_integer_overflow_test(struct expression
*expr
)
1969 struct expression
*left
, *right
;
1970 struct symbol
*type
;
1971 sval_t left_min
, right_min
, min
, max
;
1973 if (expr
->op
!= '<' && expr
->op
!= SPECIAL_UNSIGNED_LT
)
1976 left
= strip_parens(expr
->left
);
1977 right
= strip_parens(expr
->right
);
1979 if (left
->op
!= '+')
1982 type
= get_type(expr
);
1985 if (type_positive_bits(type
) == 32) {
1986 max
.type
= &uint_ctype
;
1987 max
.uvalue
= (unsigned int)-1;
1988 } else if (type_positive_bits(type
) == 64) {
1989 max
.type
= &ulong_ctype
;
1990 max
.value
= (unsigned long long)-1;
1995 if (!expr_equiv(left
->left
, right
) && !expr_equiv(left
->right
, right
))
1998 get_absolute_min(left
->left
, &left_min
);
1999 get_absolute_min(left
->right
, &right_min
);
2000 min
= sval_binop(left_min
, '+', right_min
);
2002 type
= get_type(left
);
2003 min
= sval_cast(type
, min
);
2004 max
= sval_cast(type
, max
);
2006 set_extra_chunk_true_false(left
, NULL
, alloc_estate_range(min
, max
));
2010 static void match_comparison(struct expression
*expr
)
2012 struct expression
*left_orig
= strip_parens(expr
->left
);
2013 struct expression
*right_orig
= strip_parens(expr
->right
);
2014 struct expression
*left
, *right
, *tmp
;
2015 struct expression
*prev
;
2016 struct symbol
*type
;
2019 if (match_func_comparison(expr
))
2022 type
= get_type(expr
);
2024 type
= &llong_ctype
;
2026 if (handle_integer_overflow_test(expr
))
2031 move_known_values(&left
, &right
);
2032 handle_comparison(type
, left
, expr
->op
, right
);
2036 if (do_simple_algebra(&left
, &right
))
2037 handle_comparison(type
, left
, expr
->op
, right
);
2039 prev
= get_assigned_expr(left_orig
);
2040 if (is_simple_math(prev
) && !has_variable(prev
, left_orig
)) {
2043 move_known_values(&left
, &right
);
2044 handle_comparison(type
, left
, expr
->op
, right
);
2047 prev
= get_assigned_expr(right_orig
);
2048 if (is_simple_math(prev
) && !has_variable(prev
, right_orig
)) {
2051 move_known_values(&left
, &right
);
2052 handle_comparison(type
, left
, expr
->op
, right
);
2058 if (get_last_expr_from_expression_stmt(left_orig
)) {
2059 left
= get_last_expr_from_expression_stmt(left_orig
);
2062 if (get_last_expr_from_expression_stmt(right_orig
)) {
2063 right
= get_last_expr_from_expression_stmt(right_orig
);
2071 while ((tmp
= get_assigned_expr(left
))) {
2074 left
= strip_expr(tmp
);
2077 while ((tmp
= get_assigned_expr(right
))) {
2080 right
= strip_expr(tmp
);
2083 handle_comparison(type
, left
, expr
->op
, right
);
2086 static sval_t
get_high_mask(sval_t known
)
2094 for (i
= type_bits(known
.type
) - 1; i
>= 0; i
--) {
2095 if (known
.uvalue
& (1ULL << i
))
2096 ret
.uvalue
|= (1ULL << i
);
2104 static bool handle_bit_test(struct expression
*expr
)
2106 struct range_list
*orig_rl
, *rlt
, *rlf
, *true_rl
, *false_rl
;
2107 struct expression
*shift
, *mask
, *var
;
2108 struct bit_info
*bit_info
;
2110 sval_t high
= { .type
= &int_ctype
};
2111 sval_t low
= { .type
= &int_ctype
};
2113 shift
= strip_expr(expr
->right
);
2114 mask
= strip_expr(expr
->left
);
2115 if (shift
->type
!= EXPR_BINOP
|| shift
->op
!= SPECIAL_LEFTSHIFT
) {
2116 shift
= strip_expr(expr
->left
);
2117 mask
= strip_expr(expr
->right
);
2118 if (shift
->type
!= EXPR_BINOP
|| shift
->op
!= SPECIAL_LEFTSHIFT
)
2121 if (!get_implied_value(shift
->left
, &sval
) || sval
.value
!= 1)
2123 var
= strip_expr(shift
->right
);
2125 bit_info
= get_bit_info(mask
);
2128 if (!bit_info
->possible
){
2129 set_true_false_states_expr(my_id
, var
, alloc_estate_empty(), NULL
);
2133 get_absolute_rl(var
, &orig_rl
);
2134 if (sval_is_negative(rl_min(orig_rl
)) ||
2135 rl_max(orig_rl
).uvalue
> type_bits(get_type(shift
->left
)))
2138 low
.value
= ffsll(bit_info
->possible
) - 1;
2139 high
.value
= sm_fls64(bit_info
->possible
) - 1;
2140 rlt
= alloc_rl(low
, high
);
2141 rlt
= cast_rl(get_type(var
), rlt
);
2142 true_rl
= rl_intersection(orig_rl
, rlt
);
2144 low
.value
= ffsll(bit_info
->set
) - 1;
2145 high
.value
= sm_fls64(bit_info
->set
) - 1;
2146 rlf
= alloc_rl(low
, high
);
2147 rlf
= cast_rl(get_type(var
), rlf
);
2148 false_rl
= rl_filter(orig_rl
, rlf
);
2150 set_extra_expr_true_false(var
, alloc_estate_rl(true_rl
), alloc_estate_rl(false_rl
));
2155 static void handle_AND_op(struct expression
*var
, sval_t known
)
2157 struct range_list
*orig_rl
;
2158 struct range_list
*true_rl
= NULL
;
2159 struct range_list
*false_rl
= NULL
;
2161 sval_t low_mask
= known
;
2165 get_absolute_rl(var
, &orig_rl
);
2167 if (known
.value
> 0) {
2168 bit
= ffsll(known
.value
) - 1;
2169 low_mask
.uvalue
= (1ULL << bit
) - 1;
2170 true_rl
= remove_range(orig_rl
, sval_type_val(known
.type
, 0), low_mask
);
2172 high_mask
= get_high_mask(known
);
2173 if (high_mask
.value
) {
2174 bit
= ffsll(high_mask
.value
) - 1;
2175 low_mask
.uvalue
= (1ULL << bit
) - 1;
2178 if (sval_is_negative(rl_min(orig_rl
)))
2179 false_rl
= remove_range(false_rl
, sval_type_min(known
.type
), sval_type_val(known
.type
, -1));
2180 false_rl
= remove_range(false_rl
, low_mask
, sval_type_max(known
.type
));
2181 if (type_signed(high_mask
.type
) && type_unsigned(rl_type(false_rl
))) {
2182 false_rl
= remove_range(false_rl
,
2183 sval_type_val(rl_type(false_rl
), sval_type_max(known
.type
).uvalue
),
2184 sval_type_val(rl_type(false_rl
), -1));
2186 } else if (known
.value
== 1 &&
2187 get_hard_max(var
, &max
) &&
2188 sval_cmp(max
, rl_max(orig_rl
)) == 0 &&
2190 false_rl
= remove_range(orig_rl
, max
, max
);
2192 set_extra_expr_true_false(var
,
2193 true_rl
? alloc_estate_rl(true_rl
) : NULL
,
2194 false_rl
? alloc_estate_rl(false_rl
) : NULL
);
2197 static void handle_AND_condition(struct expression
*expr
)
2201 if (handle_bit_test(expr
))
2204 if (get_implied_value(expr
->left
, &known
))
2205 handle_AND_op(expr
->right
, known
);
2206 else if (get_implied_value(expr
->right
, &known
))
2207 handle_AND_op(expr
->left
, known
);
2210 static void handle_MOD_condition(struct expression
*expr
)
2212 struct range_list
*orig_rl
;
2213 struct range_list
*true_rl
;
2214 struct range_list
*false_rl
= NULL
;
2220 if (!get_implied_value(expr
->right
, &right
) || right
.value
== 0)
2222 get_absolute_rl(expr
->left
, &orig_rl
);
2224 zero
.type
= rl_type(orig_rl
);
2226 /* We're basically dorking around the min and max here */
2227 true_rl
= remove_range(orig_rl
, zero
, zero
);
2228 if (!sval_is_max(rl_max(true_rl
)) &&
2229 !(rl_max(true_rl
).value
% right
.value
))
2230 true_rl
= remove_range(true_rl
, rl_max(true_rl
), rl_max(true_rl
));
2232 if (rl_equiv(true_rl
, orig_rl
))
2235 if (sval_is_positive(rl_min(orig_rl
)) &&
2236 (rl_max(orig_rl
).value
- rl_min(orig_rl
).value
) / right
.value
< 5) {
2240 add
= rl_min(orig_rl
);
2241 add
.value
+= right
.value
- (add
.value
% right
.value
);
2242 add
.value
-= right
.value
;
2244 for (i
= 0; i
< 5; i
++) {
2245 add
.value
+= right
.value
;
2246 if (add
.value
> rl_max(orig_rl
).value
)
2248 add_range(&false_rl
, add
, add
);
2251 if (rl_min(orig_rl
).uvalue
!= 0 &&
2252 rl_min(orig_rl
).uvalue
< right
.uvalue
) {
2253 sval_t chop
= right
;
2255 false_rl
= remove_range(orig_rl
, zero
, chop
);
2258 if (!sval_is_max(rl_max(orig_rl
)) &&
2259 (rl_max(orig_rl
).value
% right
.value
)) {
2260 sval_t chop
= rl_max(orig_rl
);
2261 chop
.value
-= chop
.value
% right
.value
;
2264 false_rl
= clone_rl(orig_rl
);
2265 false_rl
= remove_range(false_rl
, chop
, rl_max(orig_rl
));
2269 set_extra_expr_true_false(expr
->left
,
2270 true_rl
? alloc_estate_rl(true_rl
) : NULL
,
2271 false_rl
? alloc_estate_rl(false_rl
) : NULL
);
2274 /* this is actually hooked from smatch_implied.c... it's hacky, yes */
2275 void __extra_match_condition(struct expression
*expr
)
2277 expr
= strip_expr(expr
);
2278 switch (expr
->type
) {
2280 function_comparison(expr
, SPECIAL_NOTEQUAL
, zero_expr());
2285 handle_comparison(get_type(expr
), expr
, SPECIAL_NOTEQUAL
, zero_expr());
2288 match_comparison(expr
);
2290 case EXPR_ASSIGNMENT
:
2291 __extra_match_condition(expr
->left
);
2294 if (expr
->op
== '&')
2295 handle_AND_condition(expr
);
2296 if (expr
->op
== '%')
2297 handle_MOD_condition(expr
);
2302 static void assume_indexes_are_valid(struct expression
*expr
)
2304 struct expression
*array_expr
;
2306 struct expression
*offset
;
2307 struct symbol
*offset_type
;
2308 struct range_list
*rl_before
;
2309 struct range_list
*rl_after
;
2310 struct range_list
*filter
= NULL
;
2313 expr
= strip_expr(expr
);
2314 if (!is_array(expr
))
2317 offset
= get_array_offset(expr
);
2318 offset_type
= get_type(offset
);
2319 if (offset_type
&& type_signed(offset_type
)) {
2320 filter
= alloc_rl(sval_type_min(offset_type
),
2321 sval_type_val(offset_type
, -1));
2324 array_expr
= get_array_base(expr
);
2325 array_size
= get_real_array_size(array_expr
);
2326 if (array_size
> 1) {
2327 size
= sval_type_val(offset_type
, array_size
);
2328 add_range(&filter
, size
, sval_type_max(offset_type
));
2333 get_absolute_rl(offset
, &rl_before
);
2334 rl_after
= rl_filter(rl_before
, filter
);
2335 if (rl_equiv(rl_before
, rl_after
))
2337 set_extra_expr_nomod(offset
, alloc_estate_rl(rl_after
));
2340 /* returns 1 if it is not possible for expr to be value, otherwise returns 0 */
2341 int implied_not_equal(struct expression
*expr
, long long val
)
2343 return !possibly_false(expr
, SPECIAL_NOTEQUAL
, value_expr(val
));
2346 int implied_not_equal_name_sym(char *name
, struct symbol
*sym
, long long val
)
2348 struct smatch_state
*estate
;
2350 estate
= get_state(SMATCH_EXTRA
, name
, sym
);
2353 if (!rl_has_sval(estate_rl(estate
), sval_type_val(estate_type(estate
), 0)))
2358 bool is_noderef_ptr(struct expression
*expr
)
2360 struct range_list
*rl
;
2362 if (!get_implied_rl(expr
, &rl
))
2364 return is_noderef_ptr_rl(rl
);
2367 static int parent_is_err_or_null_var_sym_helper(const char *name
, struct symbol
*sym
, bool check_err_ptr
)
2369 struct smatch_state
*state
;
2374 strncpy(buf
, name
, sizeof(buf
) - 1);
2375 buf
[sizeof(buf
) - 1] = '\0';
2378 while (*start
== '*') {
2380 state
= __get_state(SMATCH_EXTRA
, start
, sym
);
2383 if (!estate_rl(state
))
2385 if (is_noderef_ptr_rl(estate_rl(state
)))
2390 while (*start
== '&')
2393 len
= strlen(start
);
2397 if (start
[len
] == '-' ||
2398 start
[len
] == '.') {
2405 state
= __get_state(SMATCH_EXTRA
, start
, sym
);
2408 if (is_noderef_ptr_rl(estate_rl(state
)))
2413 int parent_is_null_var_sym(const char *name
, struct symbol
*sym
)
2415 return parent_is_err_or_null_var_sym_helper(name
, sym
, false);
2418 int parent_is_err_or_null_var_sym(const char *name
, struct symbol
*sym
)
2420 return parent_is_err_or_null_var_sym_helper(name
, sym
, (option_project
== PROJ_KERNEL
));
2423 int parent_is_null(struct expression
*expr
)
2429 expr
= strip_expr(expr
);
2430 var
= expr_to_var_sym(expr
, &sym
);
2433 ret
= parent_is_null_var_sym(var
, sym
);
2439 static int param_used_callback(void *found
, int argc
, char **argv
, char **azColName
)
2445 static int is_kzalloc_info(struct sm_state
*sm
)
2450 * kzalloc() information is treated as special because so there is just
2451 * a lot of stuff initialized to zero and it makes building the database
2452 * take hours and hours.
2454 * In theory, we should just remove this line and not pass any unused
2455 * information, but I'm not sure enough that this code works so I want
2456 * to hold off on that for now.
2458 if (!estate_get_single_value(sm
->state
, &sval
))
2460 if (sval
.value
!= 0)
2465 static int is_really_long(struct sm_state
*sm
)
2471 while ((p
= strstr(p
, "->"))) {
2477 strlen(sm
->name
) < 40)
2482 static int filter_unused_param_value_info(struct expression
*call
, int param
, char *printed_name
, struct sm_state
*sm
)
2486 /* for function pointers assume everything is used */
2487 if (call
->fn
->type
!= EXPR_SYMBOL
)
2490 if (strcmp(printed_name
, "$") == 0 ||
2491 strcmp(printed_name
, "*$") == 0)
2495 * This is to handle __builtin_mul_overflow(). In an ideal world we
2496 * would only need this for invalid code.
2499 if (!call
->fn
->symbol
)
2502 if (!is_kzalloc_info(sm
) && !is_really_long(sm
))
2505 run_sql(¶m_used_callback
, &found
,
2506 "select * from return_implies where %s and type = %d and parameter = %d and key = '%s';",
2507 get_static_filter(call
->fn
->symbol
), PARAM_USED
, param
, printed_name
);
2511 /* If the database is not built yet, then assume everything is used */
2512 run_sql(¶m_used_callback
, &found
,
2513 "select * from return_implies where %s and type = %d;",
2514 get_static_filter(call
->fn
->symbol
), PARAM_USED
);
2521 struct range_list
*intersect_with_real_abs_var_sym(const char *name
, struct symbol
*sym
, struct range_list
*start
)
2523 struct smatch_state
*state
;
2526 * Here is the difference between implied value and real absolute, say
2531 * Then you know that a is 0-255. That's real absolute. But you don't
2532 * know for sure that it actually goes up to 255. So it's not implied.
2533 * Implied indicates a degree of certainty.
2535 * But then say you cap "a" at 8. That means you know it goes up to
2536 * 8. So now the implied value is s32min-8. But you can combine it
2537 * with the real absolute to say that actually it's 0-8.
2539 * We are combining it here. But now that I think about it, this is
2540 * probably not the ideal place to combine it because it should proably
2541 * be done earlier. Oh well, this is an improvement on what was there
2542 * before so I'm going to commit this code.
2546 state
= get_real_absolute_state_var_sym(name
, sym
);
2547 if (!state
|| !estate_rl(state
))
2550 return rl_intersection(estate_rl(state
), start
);
2553 struct range_list
*intersect_with_real_abs_expr(struct expression
*expr
, struct range_list
*start
)
2555 struct smatch_state
*state
;
2556 struct range_list
*abs_rl
;
2558 state
= get_real_absolute_state(expr
);
2559 if (!state
|| !estate_rl(state
))
2562 abs_rl
= cast_rl(rl_type(start
), estate_rl(state
));
2563 return rl_intersection(abs_rl
, start
);
2566 static void caller_info_callback(struct expression
*call
, int param
, char *printed_name
, struct sm_state
*sm
)
2568 struct range_list
*rl
;
2571 if (printed_name
[0] == '&')
2573 if (estate_is_whole(sm
->state
) || !estate_rl(sm
->state
))
2575 if (filter_unused_param_value_info(call
, param
, printed_name
, sm
))
2577 rl
= estate_rl(sm
->state
);
2578 rl
= intersect_with_real_abs_var_sym(sm
->name
, sm
->sym
, rl
);
2581 sql_insert_caller_info(call
, PARAM_VALUE
, param
, printed_name
, show_rl(rl
));
2582 if (!estate_get_single_value(sm
->state
, &dummy
)) {
2583 if (estate_has_hard_max(sm
->state
))
2584 sql_insert_caller_info(call
, HARD_MAX
, param
, printed_name
,
2585 sval_to_str(estate_max(sm
->state
)));
2586 if (estate_has_fuzzy_max(sm
->state
))
2587 sql_insert_caller_info(call
, FUZZY_MAX
, param
, printed_name
,
2588 sval_to_str(estate_get_fuzzy_max(sm
->state
)));
2592 static void returned_struct_members(int return_id
, char *return_ranges
, struct expression
*expr
)
2594 struct symbol
*returned_sym
;
2595 char *returned_name
;
2596 struct sm_state
*sm
;
2604 if (!is_pointer(expr
))
2606 if (return_ranges
&& strstr(return_ranges
, "[==$"))
2609 returned_name
= expr_to_var_sym(expr
, &returned_sym
);
2610 if (!returned_name
|| !returned_sym
)
2612 len
= strlen(returned_name
);
2614 FOR_EACH_MY_SM(my_id
, __get_cur_stree(), sm
) {
2615 if (!estate_rl(sm
->state
))
2617 if (returned_sym
!= sm
->sym
)
2619 if (strncmp(returned_name
, sm
->name
, len
) != 0)
2621 if (sm
->name
[len
] != '-')
2624 snprintf(name_buf
, sizeof(name_buf
), "$%s", sm
->name
+ len
);
2626 compare_str
= name_sym_to_param_comparison(sm
->name
, sm
->sym
);
2627 if (!compare_str
&& estate_is_whole(sm
->state
))
2629 snprintf(val_buf
, sizeof(val_buf
), "%s%s", sm
->state
->name
, compare_str
?: "");
2631 sql_insert_return_states(return_id
, return_ranges
, PARAM_VALUE
,
2632 -1, name_buf
, val_buf
);
2633 } END_FOR_EACH_SM(sm
);
2636 free_string(returned_name
);
2639 static void db_limited_before(void)
2641 unmatched_stree
= clone_stree(__get_cur_stree());
2644 static void db_limited_after(void)
2646 free_stree(&unmatched_stree
);
2649 static int basically_the_same(struct range_list
*orig
, struct range_list
*new)
2651 if (type_is_ptr(rl_type(orig
)) &&
2652 is_whole_ptr_rl(orig
) &&
2653 is_whole_ptr_rl(new))
2656 return rl_equiv(orig
, new);
2659 static void db_param_limit_binops(struct expression
*arg
, char *key
, struct range_list
*rl
)
2661 struct range_list
*left_rl
;
2662 sval_t zero
= { .type
= rl_type(rl
), };
2665 if (strcmp(key
, "$") != 0)
2669 if (!get_implied_value(arg
->right
, &sval
))
2671 if (can_integer_overflow(get_type(arg
), arg
))
2674 left_rl
= rl_binop(rl
, '/', alloc_rl(sval
, sval
));
2675 if (!rl_has_sval(rl
, zero
))
2676 left_rl
= remove_range(left_rl
, zero
, zero
);
2678 set_extra_expr_nomod(arg
->left
, alloc_estate_rl(left_rl
));
2681 static void db_param_limit_filter(struct expression
*expr
, int param
, char *key
, char *value
, enum info_type op
)
2683 struct smatch_state
*state
;
2684 struct expression
*arg
;
2687 struct var_sym_list
*vsl
= NULL
;
2688 struct sm_state
*sm
;
2689 struct symbol
*compare_type
, *var_type
;
2690 struct range_list
*rl
;
2691 struct range_list
*limit
;
2692 struct range_list
*new;
2694 struct symbol
*other_sym
;
2696 while (expr
->type
== EXPR_ASSIGNMENT
)
2697 expr
= strip_expr(expr
->right
);
2698 if (expr
->type
!= EXPR_CALL
)
2701 arg
= get_argument_from_call_expr(expr
->args
, param
);
2705 if (strcmp(key
, "$") == 0)
2706 compare_type
= get_arg_type(expr
->fn
, param
);
2708 compare_type
= get_member_type_from_key(arg
, key
);
2710 call_results_to_rl(expr
, compare_type
, value
, &limit
);
2711 if (strcmp(key
, "$") == 0)
2712 move_known_to_rl(&arg
, &limit
);
2713 name
= get_chunk_from_key(arg
, key
, &sym
, &vsl
);
2716 if (op
!= PARAM_LIMIT
&& !sym
)
2719 sm
= get_sm_state(SMATCH_EXTRA
, name
, sym
);
2721 rl
= estate_rl(sm
->state
);
2723 rl
= alloc_whole_rl(compare_type
);
2725 if (op
== PARAM_LIMIT
&& !rl_fits_in_type(rl
, compare_type
))
2728 new = rl_intersection(rl
, limit
);
2730 var_type
= get_member_type_from_key(arg
, key
);
2731 new = cast_rl(var_type
, new);
2733 /* We want to preserve the implications here */
2734 if (sm
&& basically_the_same(rl
, new))
2736 other_name
= get_other_name_sym(name
, sym
, &other_sym
);
2738 state
= alloc_estate_rl(new);
2739 if (sm
&& estate_has_hard_max(sm
->state
))
2740 estate_set_hard_max(state
);
2742 if (op
== PARAM_LIMIT
) {
2743 set_extra_nomod_vsl(name
, sym
, vsl
, NULL
, state
);
2745 set_extra_mod(name
, sym
, NULL
, state
);
2747 if (other_name
&& other_sym
) {
2748 state
= clone_estate(state
);
2749 if (op
== PARAM_LIMIT
)
2750 set_extra_nomod_vsl(other_name
, other_sym
, vsl
, NULL
, state
);
2752 set_extra_mod(other_name
, other_sym
, NULL
, state
);
2755 if (op
== PARAM_LIMIT
&& arg
->type
== EXPR_BINOP
)
2756 db_param_limit_binops(arg
, key
, new);
2761 static void db_param_limit(struct expression
*expr
, int param
, char *key
, char *value
)
2763 db_param_limit_filter(expr
, param
, key
, value
, PARAM_LIMIT
);
2766 static void db_param_filter(struct expression
*expr
, int param
, char *key
, char *value
)
2768 db_param_limit_filter(expr
, param
, key
, value
, PARAM_FILTER
);
2771 static struct expression
*get_star_pointer_hack(struct expression
*arg
, const char *key
)
2773 /* if we are setting *(p + offset) then we are setting *p */
2774 if (strcmp(key
, "*$") != 0)
2777 arg
= strip_expr(arg
);
2780 arg
= strip_expr(arg
->left
);
2781 if (!is_pointer(arg
))
2786 static bool handle_param_assign(struct expression
*expr
, int param
, char *key
, char *value
)
2788 struct expression
*arg
, *left
, *right
, *fake_assign
;
2789 struct range_list
*filter
, *filtered
;
2790 struct symbol
*arg_type
, *param_type
;
2791 struct smatch_state
*state
, *clone
;
2797 p
= strchr(value
, '[');
2803 snprintf(buf
, sizeof(buf
), "%s", p
);
2804 p
= strchr(buf
, ']');
2809 if (!split_param_key(buf
, &right_param
, right_key
, sizeof(right_key
)))
2812 left
= gen_expr_from_param_key(expr
, param
, key
);
2815 right
= gen_expr_from_param_key(expr
, right_param
, right_key
);
2819 fake_assign
= assign_expression(left
, '=', right
);
2820 fake_param_assign_helper(expr
, fake_assign
, true);
2822 /* Assignment faked. Now filter the results */
2823 arg
= get_argument_from_call_expr(expr
->args
, param
);
2826 state
= get_extra_state(left
);
2829 arg_type
= get_arg_type_from_key(expr
->fn
, param
, arg
, key
);
2830 param_type
= get_member_type_from_key(arg
, key
);
2831 if (param_type
&& param_type
->type
== SYM_STRUCT
)
2833 call_results_to_rl(expr
, arg_type
, value
, &filter
);
2834 filter
= cast_rl(param_type
, filter
);
2835 filtered
= rl_intersection(estate_rl(state
), filter
);
2837 if (!rl_equiv(estate_rl(state
), filtered
)) {
2838 clone
= clone_partial_estate(state
, filtered
);
2839 set_extra_expr_nomod(left
, clone
);
2845 static void db_param_add_set(struct expression
*expr
, int param
, char *key
, char *value
, enum info_type op
)
2847 struct expression
*arg
, *gen_expr
;
2849 char *other_name
= NULL
;
2850 struct symbol
*sym
, *other_sym
;
2851 struct symbol
*param_type
, *arg_type
;
2852 struct smatch_state
*state
;
2853 struct range_list
*new = NULL
;
2854 struct range_list
*added
= NULL
;
2856 while (expr
->type
== EXPR_ASSIGNMENT
)
2857 expr
= strip_expr(expr
->right
);
2858 if (expr
->type
!= EXPR_CALL
)
2861 if (op
== PARAM_SET
) {
2862 if (handle_param_assign(expr
, param
, key
, value
))
2866 arg
= get_argument_from_call_expr(expr
->args
, param
);
2870 arg_type
= get_arg_type_from_key(expr
->fn
, param
, arg
, key
);
2871 param_type
= get_member_type_from_key(arg
, key
);
2872 if (param_type
&& param_type
->type
== SYM_STRUCT
)
2874 name
= get_variable_from_key(arg
, key
, &sym
);
2875 if (!name
|| !sym
) {
2876 arg
= get_star_pointer_hack(arg
, key
);
2879 name
= get_variable_from_key(arg
, key
, &sym
);
2883 gen_expr
= gen_expression_from_key(arg
, key
);
2885 state
= get_state(SMATCH_EXTRA
, name
, sym
);
2887 new = estate_rl(state
);
2889 call_results_to_rl(expr
, arg_type
, value
, &added
);
2890 added
= cast_rl(param_type
, added
);
2891 if (op
== PARAM_SET
)
2894 new = rl_union(new, added
);
2896 other_name
= get_other_name_sym_nostack(name
, sym
, &other_sym
);
2897 set_extra_mod(name
, sym
, gen_expr
, alloc_estate_rl(new));
2898 if (other_name
&& other_sym
)
2899 set_extra_mod(other_name
, other_sym
, gen_expr
, alloc_estate_rl(new));
2901 free_string(other_name
);
2905 static void db_param_add(struct expression
*expr
, int param
, char *key
, char *value
)
2907 in_param_set
= true;
2908 db_param_add_set(expr
, param
, key
, value
, PARAM_ADD
);
2909 in_param_set
= false;
2912 static void db_param_set(struct expression
*expr
, int param
, char *key
, char *value
)
2914 in_param_set
= true;
2915 db_param_add_set(expr
, param
, key
, value
, PARAM_SET
);
2916 in_param_set
= false;
2919 static void match_lost_param(struct expression
*call
, int param
)
2921 struct expression
*arg
;
2923 if (is_const_param(call
->fn
, param
))
2926 arg
= get_argument_from_call_expr(call
->args
, param
);
2930 arg
= strip_expr(arg
);
2931 if (arg
->type
== EXPR_PREOP
&& arg
->op
== '&')
2932 set_extra_expr_mod(arg
->unop
, alloc_estate_whole(get_type(arg
->unop
)));
2934 ; /* if pointer then set struct members, maybe?*/
2937 static void db_param_value(struct expression
*expr
, int param
, char *key
, char *value
)
2939 struct expression
*call
;
2942 struct symbol
*type
;
2943 struct range_list
*rl
= NULL
;
2949 while (call
->type
== EXPR_ASSIGNMENT
)
2950 call
= strip_expr(call
->right
);
2951 if (call
->type
!= EXPR_CALL
)
2954 type
= get_member_type_from_key(expr
->left
, key
);
2955 name
= get_variable_from_key(expr
->left
, key
, &sym
);
2959 call_results_to_rl(call
, type
, value
, &rl
);
2961 set_extra_mod(name
, sym
, NULL
, alloc_estate_rl(rl
));
2966 static void set_param_value(const char *name
, struct symbol
*sym
, char *key
, char *value
)
2968 struct expression
*expr
;
2969 struct range_list
*rl
= NULL
;
2970 struct smatch_state
*state
;
2971 struct symbol
*type
;
2972 char *key_orig
= key
;
2976 expr
= symbol_expression(sym
);
2977 fullname
= get_variable_from_key(expr
, key
, NULL
);
2981 type
= get_member_type_from_key(expr
, key_orig
);
2982 str_to_rl(type
, value
, &rl
);
2983 state
= alloc_estate_rl(rl
);
2984 if (estate_get_single_value(state
, &dummy
))
2985 estate_set_hard_max(state
);
2986 set_state(SMATCH_EXTRA
, fullname
, sym
, state
);
2989 static void db_buf_add_helper(struct expression
*expr
, void *data
)
2991 struct expression
*left
= expr
->left
;
2992 struct sm_state
*sm
;
2994 sm
= get_sm_state_expr(my_id
, left
);
2998 set_state(my_id
, sm
->name
, sm
->sym
, alloc_estate_whole(estate_type(sm
->state
)));
3001 static void db_buf_add(struct expression
*expr
, int param
, char *key
, char *value
)
3003 struct expression
*arg
;
3006 * There really isn't much we can do with a BUF_ADD. A BUF_CLEAR is
3007 * like a full modification which some stuff cares about. A no_mod
3008 * thing is useful because that's normally bounds checking etc. But
3009 * with BUF_ADD the only thing we can say is do is delete any previous
3014 arg
= gen_expr_from_param_key(expr
, param
, key
);
3018 create_recursive_fake_assignments(deref_expression(arg
), &db_buf_add_helper
, NULL
);
3021 static void set_param_fuzzy_max(const char *name
, struct symbol
*sym
, char *key
, char *value
)
3023 struct expression
*expr
;
3024 struct range_list
*rl
= NULL
;
3025 struct smatch_state
*state
;
3026 struct symbol
*type
;
3030 expr
= symbol_expression(sym
);
3031 fullname
= get_variable_from_key(expr
, key
, NULL
);
3035 state
= get_state(SMATCH_EXTRA
, fullname
, sym
);
3038 type
= estate_type(state
);
3039 str_to_rl(type
, value
, &rl
);
3040 if (!rl_to_sval(rl
, &max
))
3042 estate_set_fuzzy_max(state
, max
);
3045 static void set_param_hard_max(const char *name
, struct symbol
*sym
, char *key
, char *value
)
3047 struct smatch_state
*state
;
3048 struct expression
*expr
;
3051 expr
= symbol_expression(sym
);
3052 fullname
= get_variable_from_key(expr
, key
, NULL
);
3056 state
= get_state(SMATCH_EXTRA
, fullname
, sym
);
3059 estate_set_hard_max(state
);
3062 static struct sm_state
*get_sm_from_call(struct expression
*expr
)
3064 struct expression
*fake
;
3065 struct sm_state
*ret
;
3068 if (is_fake_call(expr
))
3071 fake
= expr_get_fake_parent_expr(expr
);
3072 if (fake
&& fake
->type
== EXPR_ASSIGNMENT
) {
3073 ret
= get_sm_state_expr(SMATCH_EXTRA
, fake
->left
);
3078 snprintf(buf
, sizeof(buf
), "return %p", expr
);
3079 return get_sm_state(SMATCH_EXTRA
, buf
, NULL
);
3082 struct sm_state
*get_extra_sm_state(struct expression
*expr
)
3086 struct sm_state
*ret
= NULL
;
3088 expr
= strip_expr(expr
);
3092 if (expr
->type
== EXPR_CALL
)
3093 return get_sm_from_call(expr
);
3095 name
= expr_to_known_chunk_sym(expr
, &sym
);
3099 ret
= get_sm_state(SMATCH_EXTRA
, name
, sym
);
3105 struct smatch_state
*get_extra_state(struct expression
*expr
)
3107 struct sm_state
*sm
;
3109 sm
= get_extra_sm_state(expr
);
3115 void register_smatch_extra(int id
)
3119 set_dynamic_states(my_id
);
3120 add_merge_hook(my_id
, &merge_estates
);
3121 add_unmatched_state_hook(my_id
, &unmatched_state
);
3122 select_caller_info_hook(set_param_value
, PARAM_VALUE
);
3123 select_caller_info_hook(set_param_fuzzy_max
, FUZZY_MAX
);
3124 select_caller_info_hook(set_param_hard_max
, HARD_MAX
);
3125 select_return_states_before(&db_limited_before
);
3126 select_return_states_hook(PARAM_LIMIT
, &db_param_limit
);
3127 select_return_states_hook(PARAM_FILTER
, &db_param_filter
);
3128 select_return_states_hook(PARAM_ADD
, &db_param_add
);
3129 select_return_states_hook(PARAM_SET
, &db_param_set
);
3130 select_return_states_hook(BUF_ADD
, &db_buf_add
);
3131 add_lost_param_hook(&match_lost_param
);
3132 select_return_states_hook(PARAM_VALUE
, &db_param_value
);
3133 select_return_states_after(&db_limited_after
);
3136 static void match_link_modify(struct sm_state
*sm
, struct expression
*mod_expr
)
3138 struct var_sym_list
*links
;
3139 struct var_sym
*tmp
;
3140 struct smatch_state
*state
;
3142 links
= sm
->state
->data
;
3144 FOR_EACH_PTR(links
, tmp
) {
3145 if (sm
->sym
== tmp
->sym
&&
3146 strcmp(sm
->name
, tmp
->var
) == 0)
3148 state
= get_state(SMATCH_EXTRA
, tmp
->var
, tmp
->sym
);
3151 set_state(SMATCH_EXTRA
, tmp
->var
, tmp
->sym
, alloc_estate_whole(estate_type(state
)));
3152 } END_FOR_EACH_PTR(tmp
);
3153 set_state(link_id
, sm
->name
, sm
->sym
, &undefined
);
3156 void register_smatch_extra_links(int id
)
3159 set_dynamic_states(link_id
);
3162 void register_smatch_extra_late(int id
)
3164 add_merge_hook(link_id
, &merge_link_states
);
3165 add_modification_hook(link_id
, &match_link_modify
);
3166 add_hook(&match_dereferences
, DEREF_HOOK
);
3167 add_hook(&match_pointer_as_array
, OP_HOOK
);
3168 select_return_implies_hook_early(DEREFERENCE
, &set_param_dereferenced
);
3169 add_hook(&match_function_call
, FUNCTION_CALL_HOOK
);
3170 add_hook(&match_assign
, ASSIGNMENT_HOOK
);
3171 add_hook(&match_assign
, GLOBAL_ASSIGNMENT_HOOK
);
3172 add_hook(&unop_expr
, OP_HOOK
);
3173 add_hook(&asm_expr
, ASM_HOOK
);
3175 add_caller_info_callback(my_id
, caller_info_callback
);
3176 add_split_return_callback(&returned_struct_members
);
3178 // add_hook(&assume_indexes_are_valid, OP_HOOK);