2 * Copyright (C) 2012 Oracle.
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 * The point here is to store the relationships between two variables.
21 * To do that we create a state with the two variables in alphabetical order:
22 * ->name = "x vs y" and the state would be "<". On the false path the state
25 * Part of the trick of it is that if x or y is modified then we need to reset
26 * the state. We need to keep a list of all the states which depend on x and
27 * all the states which depend on y. The link_id code handles this.
32 #include "smatch_extra.h"
33 #include "smatch_slist.h"
35 static int compare_id
;
37 static int inc_dec_id
;
38 static int inc_dec_link_id
;
40 /* for handling for loops */
44 ALLOCATOR(compare_data
, "compare data");
46 static struct symbol
*vsl_to_sym(struct var_sym_list
*vsl
)
52 if (ptr_list_size((struct ptr_list
*)vsl
) != 1)
54 vs
= first_ptr_list((struct ptr_list
*)vsl
);
58 struct smatch_state
*alloc_compare_state(
59 struct expression
*left
,
60 const char *left_var
, struct var_sym_list
*left_vsl
,
62 struct expression
*right
,
63 const char *right_var
, struct var_sym_list
*right_vsl
)
65 struct smatch_state
*state
;
66 struct compare_data
*data
;
68 state
= __alloc_smatch_state(0);
69 state
->name
= alloc_sname(show_special(comparison
));
70 data
= __alloc_compare_data(0);
72 data
->left_var
= alloc_sname(left_var
);
73 data
->left_vsl
= clone_var_sym_list(left_vsl
);
74 data
->comparison
= comparison
;
76 data
->right_var
= alloc_sname(right_var
);
77 data
->right_vsl
= clone_var_sym_list(right_vsl
);
82 int state_to_comparison(struct smatch_state
*state
)
84 if (!state
|| !state
->data
)
86 return ((struct compare_data
*)state
->data
)->comparison
;
90 * flip_comparison() reverses the op left and right. So "x >= y" becomes "y <= x".
92 int flip_comparison(int op
)
99 case SPECIAL_UNSIGNED_LT
:
100 return SPECIAL_UNSIGNED_GT
;
103 case SPECIAL_UNSIGNED_LTE
:
104 return SPECIAL_UNSIGNED_GTE
;
106 return SPECIAL_EQUAL
;
107 case SPECIAL_NOTEQUAL
:
108 return SPECIAL_NOTEQUAL
;
111 case SPECIAL_UNSIGNED_GTE
:
112 return SPECIAL_UNSIGNED_LTE
;
115 case SPECIAL_UNSIGNED_GT
:
116 return SPECIAL_UNSIGNED_LT
;
118 sm_msg("internal smatch bug. unhandled comparison %d", op
);
123 int negate_comparison(int op
)
130 case SPECIAL_UNSIGNED_LT
:
131 return SPECIAL_UNSIGNED_GTE
;
134 case SPECIAL_UNSIGNED_LTE
:
135 return SPECIAL_UNSIGNED_GT
;
137 return SPECIAL_NOTEQUAL
;
138 case SPECIAL_NOTEQUAL
:
139 return SPECIAL_EQUAL
;
142 case SPECIAL_UNSIGNED_GTE
:
143 return SPECIAL_UNSIGNED_LT
;
146 case SPECIAL_UNSIGNED_GT
:
147 return SPECIAL_UNSIGNED_LTE
;
149 sm_msg("internal smatch bug. unhandled comparison %d", op
);
154 static int rl_comparison(struct range_list
*left_rl
, struct range_list
*right_rl
)
156 sval_t left_min
, left_max
, right_min
, right_max
;
158 if (!left_rl
|| !right_rl
)
161 left_min
= rl_min(left_rl
);
162 left_max
= rl_max(left_rl
);
163 right_min
= rl_min(right_rl
);
164 right_max
= rl_max(right_rl
);
166 if (left_min
.value
== left_max
.value
&&
167 right_min
.value
== right_max
.value
&&
168 left_min
.value
== right_min
.value
)
169 return SPECIAL_EQUAL
;
171 if (sval_cmp(left_max
, right_min
) < 0)
173 if (sval_cmp(left_max
, right_min
) == 0)
175 if (sval_cmp(left_min
, right_max
) > 0)
177 if (sval_cmp(left_min
, right_max
) == 0)
183 static struct range_list
*get_orig_rl(struct var_sym_list
*vsl
)
186 struct smatch_state
*state
;
190 sym
= vsl_to_sym(vsl
);
191 if (!sym
|| !sym
->ident
)
193 state
= get_orig_estate(sym
->ident
->name
, sym
);
194 return estate_rl(state
);
197 static struct smatch_state
*unmatched_comparison(struct sm_state
*sm
)
199 struct compare_data
*data
= sm
->state
->data
;
200 struct range_list
*left_rl
, *right_rl
;
206 if (strstr(data
->left_var
, " orig"))
207 left_rl
= get_orig_rl(data
->left_vsl
);
208 else if (!get_implied_rl_var_sym(data
->left_var
, vsl_to_sym(data
->left_vsl
), &left_rl
))
210 if (strstr(data
->right_var
, " orig"))
211 right_rl
= get_orig_rl(data
->right_vsl
);
212 else if (!get_implied_rl_var_sym(data
->right_var
, vsl_to_sym(data
->right_vsl
), &right_rl
))
215 op
= rl_comparison(left_rl
, right_rl
);
217 return alloc_compare_state(
218 data
->left
, data
->left_var
, data
->left_vsl
,
220 data
->right
, data
->right_var
, data
->right_vsl
);
225 /* remove_unsigned_from_comparison() is obviously a hack. */
226 int remove_unsigned_from_comparison(int op
)
229 case SPECIAL_UNSIGNED_LT
:
231 case SPECIAL_UNSIGNED_LTE
:
233 case SPECIAL_UNSIGNED_GTE
:
235 case SPECIAL_UNSIGNED_GT
:
243 * This is for when you merge states "a < b" and "a == b", the result is that
244 * we can say for sure, "a <= b" after the merge.
246 int merge_comparisons(int one
, int two
)
253 one
= remove_unsigned_from_comparison(one
);
254 two
= remove_unsigned_from_comparison(two
);
304 return SPECIAL_NOTEQUAL
;
315 * This is for if you have "a < b" and "b <= c". Or in other words,
316 * "a < b <= c". You would call this like get_combined_comparison('<', '<=').
317 * The return comparison would be '<'.
319 * This function is different from merge_comparisons(), for example:
320 * merge_comparison('<', '==') returns '<='
321 * get_combined_comparison('<', '==') returns '<'
323 int combine_comparisons(int left_compare
, int right_compare
)
327 left_compare
= remove_unsigned_from_comparison(left_compare
);
328 right_compare
= remove_unsigned_from_comparison(right_compare
);
332 switch (left_compare
) {
341 return right_compare
;
350 switch (right_compare
) {
382 static int filter_comparison(int orig
, int op
)
394 case SPECIAL_NOTEQUAL
:
404 case SPECIAL_NOTEQUAL
:
413 case SPECIAL_UNSIGNED_LTE
:
414 case SPECIAL_UNSIGNED_GTE
:
415 return SPECIAL_EQUAL
;
418 case SPECIAL_NOTEQUAL
:
423 case SPECIAL_UNSIGNED_LT
:
424 case SPECIAL_UNSIGNED_LTE
:
425 return SPECIAL_UNSIGNED_LT
;
426 case SPECIAL_NOTEQUAL
:
431 case SPECIAL_UNSIGNED_GT
:
432 case SPECIAL_UNSIGNED_GTE
:
433 return SPECIAL_UNSIGNED_GT
;
439 return SPECIAL_EQUAL
;
444 case SPECIAL_NOTEQUAL
:
452 case SPECIAL_NOTEQUAL
:
456 case SPECIAL_UNSIGNED_LT
:
458 case SPECIAL_UNSIGNED_LT
:
459 case SPECIAL_UNSIGNED_LTE
:
460 case SPECIAL_NOTEQUAL
:
461 return SPECIAL_UNSIGNED_LT
;
464 case SPECIAL_UNSIGNED_LTE
:
466 case SPECIAL_UNSIGNED_LT
:
467 case SPECIAL_UNSIGNED_LTE
:
470 case SPECIAL_NOTEQUAL
:
471 return SPECIAL_UNSIGNED_LT
;
472 case SPECIAL_UNSIGNED_GTE
:
473 return SPECIAL_EQUAL
;
476 case SPECIAL_UNSIGNED_GTE
:
478 case SPECIAL_UNSIGNED_LTE
:
479 return SPECIAL_EQUAL
;
480 case SPECIAL_NOTEQUAL
:
481 return SPECIAL_UNSIGNED_GT
;
483 case SPECIAL_UNSIGNED_GTE
:
484 case SPECIAL_UNSIGNED_GT
:
488 case SPECIAL_UNSIGNED_GT
:
490 case SPECIAL_UNSIGNED_GT
:
491 case SPECIAL_UNSIGNED_GTE
:
492 case SPECIAL_NOTEQUAL
:
493 return SPECIAL_UNSIGNED_GT
;
500 struct smatch_state
*merge_compare_states(struct smatch_state
*s1
, struct smatch_state
*s2
)
502 struct compare_data
*data
= s1
->data
;
505 op
= merge_comparisons(state_to_comparison(s1
), state_to_comparison(s2
));
507 return alloc_compare_state(
508 data
->left
, data
->left_var
, data
->left_vsl
,
510 data
->right
, data
->right_var
, data
->right_vsl
);
514 static struct smatch_state
*alloc_link_state(struct string_list
*links
)
516 struct smatch_state
*state
;
517 static char buf
[256];
521 state
= __alloc_smatch_state(0);
524 FOR_EACH_PTR(links
, tmp
) {
526 snprintf(buf
, sizeof(buf
), "%s", tmp
);
528 append(buf
, ", ", sizeof(buf
));
529 append(buf
, tmp
, sizeof(buf
));
531 } END_FOR_EACH_PTR(tmp
);
533 state
->name
= alloc_sname(buf
);
538 static void save_start_states(struct statement
*stmt
)
540 struct symbol
*param
;
542 char state_name
[128];
543 struct smatch_state
*state
;
544 struct string_list
*links
;
547 FOR_EACH_PTR(cur_func_sym
->ctype
.base_type
->arguments
, param
) {
548 struct var_sym_list
*left_vsl
= NULL
;
549 struct var_sym_list
*right_vsl
= NULL
;
553 snprintf(orig
, sizeof(orig
), "%s orig", param
->ident
->name
);
554 snprintf(state_name
, sizeof(state_name
), "%s vs %s", param
->ident
->name
, orig
);
555 add_var_sym(&left_vsl
, param
->ident
->name
, param
);
556 add_var_sym(&right_vsl
, orig
, param
);
557 state
= alloc_compare_state(
558 NULL
, param
->ident
->name
, left_vsl
,
560 NULL
, alloc_sname(orig
), right_vsl
);
561 set_state(compare_id
, state_name
, NULL
, state
);
563 link
= alloc_sname(state_name
);
565 insert_string(&links
, link
);
566 state
= alloc_link_state(links
);
567 set_state(link_id
, param
->ident
->name
, param
, state
);
568 } END_FOR_EACH_PTR(param
);
571 static struct smatch_state
*merge_links(struct smatch_state
*s1
, struct smatch_state
*s2
)
573 struct smatch_state
*ret
;
574 struct string_list
*links
;
576 links
= combine_string_lists(s1
->data
, s2
->data
);
577 ret
= alloc_link_state(links
);
581 static void save_link_var_sym(const char *var
, struct symbol
*sym
, const char *link
)
583 struct smatch_state
*old_state
, *new_state
;
584 struct string_list
*links
;
587 old_state
= get_state(link_id
, var
, sym
);
589 links
= clone_str_list(old_state
->data
);
593 new = alloc_sname(link
);
594 insert_string(&links
, new);
596 new_state
= alloc_link_state(links
);
597 set_state(link_id
, var
, sym
, new_state
);
600 static void match_inc(struct sm_state
*sm
)
602 struct string_list
*links
;
603 struct smatch_state
*state
;
608 links
= sm
->state
->data
;
610 FOR_EACH_PTR(links
, tmp
) {
611 state
= get_state(compare_id
, tmp
, NULL
);
614 if (strncmp(sm
->name
, tmp
, strlen(sm
->name
)) != 0 ||
615 tmp
[strlen(sm
->name
)] != ' ')
618 op
= state_to_comparison(state
);
620 switch (flip
? flip_comparison(op
) : op
) {
623 case SPECIAL_UNSIGNED_GTE
:
625 case SPECIAL_UNSIGNED_GT
: {
626 struct compare_data
*data
= state
->data
;
627 struct smatch_state
*new;
629 new = alloc_compare_state(
630 data
->left
, data
->left_var
, data
->left_vsl
,
632 data
->right
, data
->right_var
, data
->right_vsl
);
633 set_state(compare_id
, tmp
, NULL
, new);
637 set_state(compare_id
, tmp
, NULL
, &undefined
);
639 } END_FOR_EACH_PTR(tmp
);
642 static void match_dec(struct sm_state
*sm
)
644 struct string_list
*links
;
645 struct smatch_state
*state
;
648 links
= sm
->state
->data
;
650 FOR_EACH_PTR(links
, tmp
) {
651 state
= get_state(compare_id
, tmp
, NULL
);
653 switch (state_to_comparison(state
)) {
656 case SPECIAL_UNSIGNED_LTE
:
658 case SPECIAL_UNSIGNED_LT
: {
659 struct compare_data
*data
= state
->data
;
660 struct smatch_state
*new;
662 new = alloc_compare_state(
663 data
->left
, data
->left_var
, data
->left_vsl
,
665 data
->right
, data
->right_var
, data
->right_vsl
);
666 set_state(compare_id
, tmp
, NULL
, new);
670 set_state(compare_id
, tmp
, NULL
, &undefined
);
672 } END_FOR_EACH_PTR(tmp
);
675 static int match_inc_dec(struct sm_state
*sm
, struct expression
*mod_expr
)
679 if (mod_expr
->type
!= EXPR_PREOP
&& mod_expr
->type
!= EXPR_POSTOP
)
682 if (mod_expr
->op
== SPECIAL_INCREMENT
) {
686 if (mod_expr
->op
== SPECIAL_DECREMENT
) {
693 static void match_modify(struct sm_state
*sm
, struct expression
*mod_expr
)
695 struct string_list
*links
;
699 * if (foo > bar) then ++foo is also > bar.
701 if (match_inc_dec(sm
, mod_expr
))
704 links
= sm
->state
->data
;
706 FOR_EACH_PTR(links
, tmp
) {
707 set_state(compare_id
, tmp
, NULL
, &undefined
);
708 } END_FOR_EACH_PTR(tmp
);
709 set_state(link_id
, sm
->name
, sm
->sym
, &undefined
);
712 static char *chunk_to_var_sym(struct expression
*expr
, struct symbol
**sym
)
714 expr
= strip_expr(expr
);
720 if (expr
->type
== EXPR_PREOP
&&
721 (expr
->op
== SPECIAL_INCREMENT
||
722 expr
->op
== SPECIAL_DECREMENT
))
723 expr
= strip_expr(expr
->unop
);
725 if (expr
->type
== EXPR_CALL
) {
728 snprintf(buf
, sizeof(buf
), "return %p", expr
);
729 return alloc_string(buf
);
732 return expr_to_chunk_sym_vsl(expr
, sym
, NULL
);
735 static char *chunk_to_var(struct expression
*expr
)
737 return chunk_to_var_sym(expr
, NULL
);
740 static struct smatch_state
*get_state_chunk(int owner
, struct expression
*expr
)
744 struct smatch_state
*ret
;
746 name
= chunk_to_var_sym(expr
, &sym
);
750 ret
= get_state(owner
, name
, sym
);
755 static void save_link(struct expression
*expr
, char *link
)
760 expr
= strip_expr(expr
);
761 if (expr
->type
== EXPR_BINOP
) {
764 chunk
= chunk_to_var(expr
);
768 save_link(expr
->left
, link
);
769 save_link(expr
->right
, link
);
770 save_link_var_sym(chunk
, NULL
, link
);
774 var
= chunk_to_var_sym(expr
, &sym
);
778 save_link_var_sym(var
, sym
, link
);
782 static int get_orig_comparison(struct stree
*pre_stree
, const char *left
, const char *right
)
784 struct smatch_state
*state
;
785 struct compare_data
*data
;
787 char state_name
[256];
789 if (strcmp(left
, right
) > 0) {
790 const char *tmp
= right
;
797 snprintf(state_name
, sizeof(state_name
), "%s vs %s", left
, right
);
798 state
= get_state_stree(pre_stree
, compare_id
, state_name
, NULL
);
799 if (!state
|| !state
->data
)
803 return flip_comparison(data
->comparison
);
804 return data
->comparison
;
808 static int have_common_var_sym(struct var_sym_list
*left_vsl
, struct var_sym_list
*right_vsl
)
812 FOR_EACH_PTR(left_vsl
, tmp
) {
813 if (in_var_sym_list(right_vsl
, tmp
->var
, tmp
->sym
))
815 } END_FOR_EACH_PTR(tmp
);
821 * The idea here is that we take a comparison "a < b" and then we look at all
822 * the things which "b" is compared against "b < c" and we say that that implies
823 * a relationship "a < c".
825 * The names here about because the comparisons are organized like this
829 static void update_tf_links(struct stree
*pre_stree
,
830 struct expression
*left_expr
,
831 const char *left_var
, struct var_sym_list
*left_vsl
,
832 int left_comparison
, int left_false_comparison
,
833 const char *mid_var
, struct var_sym_list
*mid_vsl
,
834 struct string_list
*links
)
836 struct smatch_state
*state
;
837 struct smatch_state
*true_state
, *false_state
;
838 struct compare_data
*data
;
839 struct expression
*right_expr
;
840 const char *right_var
;
841 struct var_sym_list
*right_vsl
;
843 int right_comparison
;
845 int false_comparison
;
847 char state_name
[256];
850 FOR_EACH_PTR(links
, tmp
) {
851 state
= get_state_stree(pre_stree
, compare_id
, tmp
, NULL
);
852 if (!state
|| !state
->data
)
855 right_comparison
= data
->comparison
;
856 right_expr
= data
->right
;
857 right_var
= data
->right_var
;
858 right_vsl
= data
->right_vsl
;
859 if (strcmp(mid_var
, right_var
) == 0) {
860 right_expr
= data
->left
;
861 right_var
= data
->left_var
;
862 right_vsl
= data
->left_vsl
;
863 right_comparison
= flip_comparison(right_comparison
);
865 if (have_common_var_sym(left_vsl
, right_vsl
))
868 orig_comparison
= get_orig_comparison(pre_stree
, left_var
, right_var
);
870 true_comparison
= combine_comparisons(left_comparison
, right_comparison
);
871 false_comparison
= combine_comparisons(left_false_comparison
, right_comparison
);
873 true_comparison
= filter_comparison(orig_comparison
, true_comparison
);
874 false_comparison
= filter_comparison(orig_comparison
, false_comparison
);
876 if (strcmp(left_var
, right_var
) > 0) {
877 struct expression
*tmp_expr
= left_expr
;
878 const char *tmp_var
= left_var
;
879 struct var_sym_list
*tmp_vsl
= left_vsl
;
881 left_expr
= right_expr
;
882 left_var
= right_var
;
883 left_vsl
= right_vsl
;
884 right_expr
= tmp_expr
;
887 true_comparison
= flip_comparison(true_comparison
);
888 false_comparison
= flip_comparison(false_comparison
);
891 if (!true_comparison
&& !false_comparison
)
895 true_state
= alloc_compare_state(
896 left_expr
, left_var
, left_vsl
,
898 right_expr
, right_var
, right_vsl
);
901 if (false_comparison
)
902 false_state
= alloc_compare_state(
903 left_expr
, left_var
, left_vsl
,
905 right_expr
, right_var
, right_vsl
);
909 snprintf(state_name
, sizeof(state_name
), "%s vs %s", left_var
, right_var
);
910 set_true_false_states(compare_id
, state_name
, NULL
, true_state
, false_state
);
911 FOR_EACH_PTR(left_vsl
, vs
) {
912 save_link_var_sym(vs
->var
, vs
->sym
, state_name
);
913 } END_FOR_EACH_PTR(vs
);
914 FOR_EACH_PTR(right_vsl
, vs
) {
915 save_link_var_sym(vs
->var
, vs
->sym
, state_name
);
916 } END_FOR_EACH_PTR(vs
);
917 if (!vsl_to_sym(left_vsl
))
918 save_link_var_sym(left_var
, NULL
, state_name
);
919 if (!vsl_to_sym(right_vsl
))
920 save_link_var_sym(right_var
, NULL
, state_name
);
921 } END_FOR_EACH_PTR(tmp
);
924 static void update_tf_data(struct stree
*pre_stree
,
925 struct expression
*left_expr
,
926 const char *left_name
, struct var_sym_list
*left_vsl
,
927 struct expression
*right_expr
,
928 const char *right_name
, struct var_sym_list
*right_vsl
,
929 int true_comparison
, int false_comparison
)
931 struct smatch_state
*state
;
933 state
= get_state_stree(pre_stree
, link_id
, right_name
, vsl_to_sym(right_vsl
));
935 update_tf_links(pre_stree
, left_expr
, left_name
, left_vsl
, true_comparison
, false_comparison
, right_name
, right_vsl
, state
->data
);
937 state
= get_state_stree(pre_stree
, link_id
, left_name
, vsl_to_sym(left_vsl
));
939 update_tf_links(pre_stree
, right_expr
, right_name
, right_vsl
, flip_comparison(true_comparison
), flip_comparison(false_comparison
), left_name
, left_vsl
, state
->data
);
942 static void iter_modify(struct sm_state
*sm
, struct expression
*mod_expr
)
944 if (sm
->state
!= &start
||
946 (mod_expr
->type
!= EXPR_PREOP
&& mod_expr
->type
!= EXPR_POSTOP
) ||
947 mod_expr
->op
!= SPECIAL_INCREMENT
)
948 set_state(inc_dec_id
, sm
->name
, sm
->sym
, &undefined
);
950 set_state(inc_dec_id
, sm
->name
, sm
->sym
, &incremented
);
953 static void handle_for_loops(struct expression
*expr
, char *state_name
, struct smatch_state
*false_state
)
956 char *iter_name
, *cap_name
;
957 struct symbol
*iter_sym
, *cap_sym
;
958 struct compare_data
*data
;
960 if (expr
->op
!= '<' && expr
->op
!= SPECIAL_UNSIGNED_LT
)
963 if (!__cur_stmt
|| !__prev_stmt
)
965 if (__cur_stmt
->type
!= STMT_ITERATOR
)
967 if (__cur_stmt
->iterator_pre_condition
!= expr
)
970 /* literals are handled in smatch_extra.c */
971 if (get_value(expr
->right
, &sval
))
974 /* First time checking the condition */
975 if (__prev_stmt
== __cur_stmt
->iterator_pre_statement
) {
976 if (!get_implied_value(expr
->left
, &sval
) ||
980 iter_name
= expr_to_var_sym(expr
->left
, &iter_sym
);
981 cap_name
= expr_to_var_sym(expr
->right
, &cap_sym
);
982 if (!iter_name
|| !cap_name
|| !iter_sym
|| !cap_sym
) {
983 free_string(iter_name
);
984 free_string(cap_name
);
988 set_state(inc_dec_id
, iter_name
, iter_sym
, &start
);
989 store_link(inc_dec_link_id
, cap_name
, cap_sym
, iter_name
, iter_sym
);
991 free_string(iter_name
);
992 free_string(cap_name
);
996 /* Second time checking the condtion */
997 if (__prev_stmt
!= __cur_stmt
->iterator_post_statement
)
1000 if (get_state_chunk(inc_dec_id
, expr
->left
) != &incremented
)
1003 data
= false_state
->data
;
1004 false_state
= alloc_compare_state(
1005 data
->left
, data
->left_var
, data
->left_vsl
,
1007 data
->right
, data
->right_var
, data
->right_vsl
);
1009 set_true_false_states(compare_id
, state_name
, NULL
, NULL
, false_state
);
1012 static int is_plus_one(struct expression
*expr
)
1016 if (expr
->type
!= EXPR_BINOP
|| expr
->op
!= '+')
1018 if (!get_implied_value(expr
->right
, &sval
) || sval
.value
!= 1)
1023 static int is_minus_one(struct expression
*expr
)
1027 if (expr
->type
!= EXPR_BINOP
|| expr
->op
!= '-')
1029 if (!get_implied_value(expr
->right
, &sval
) || sval
.value
!= 1)
1034 static void move_plus_to_minus_helper(struct expression
**left_p
, struct expression
**right_p
)
1036 struct expression
*left
= *left_p
;
1037 struct expression
*right
= *right_p
;
1040 * These two are basically equivalent: "foo + 1 != bar" and
1041 * "foo != bar - 1". There are issues with signedness and integer
1042 * overflows. There are also issues with type as well. But let's
1043 * pretend we can ignore all that stuff for now.
1047 if (!is_plus_one(left
))
1050 *left_p
= left
->left
;
1051 *right_p
= binop_expression(right
, '-', left
->right
);
1054 static void move_plus_to_minus(struct expression
**left_p
, struct expression
**right_p
)
1056 if (is_plus_one(*left_p
) && is_plus_one(*right_p
))
1059 move_plus_to_minus_helper(left_p
, right_p
);
1060 move_plus_to_minus_helper(right_p
, left_p
);
1063 static void handle_comparison(struct expression
*left_expr
, int op
, struct expression
*right_expr
, char **_state_name
, struct smatch_state
**_false_state
)
1067 struct symbol
*left_sym
, *right_sym
;
1068 struct var_sym_list
*left_vsl
, *right_vsl
;
1070 int orig_comparison
;
1071 struct smatch_state
*true_state
, *false_state
;
1072 static char state_name
[256];
1073 struct stree
*pre_stree
;
1076 left_expr
= strip_parens(left_expr
);
1077 right_expr
= strip_parens(right_expr
);
1079 false_op
= negate_comparison(op
);
1081 move_plus_to_minus(&left_expr
, &right_expr
);
1083 if (op
== SPECIAL_UNSIGNED_LT
&&
1084 get_implied_value(left_expr
, &sval
) &&
1086 false_op
= SPECIAL_EQUAL
;
1088 if (op
== SPECIAL_UNSIGNED_GT
&&
1089 get_implied_value(right_expr
, &sval
) &&
1091 false_op
= SPECIAL_EQUAL
;
1093 left
= chunk_to_var_sym(left_expr
, &left_sym
);
1096 left_vsl
= expr_to_vsl(left_expr
);
1097 right
= chunk_to_var_sym(right_expr
, &right_sym
);
1100 right_vsl
= expr_to_vsl(right_expr
);
1102 if (strcmp(left
, right
) > 0) {
1103 struct symbol
*tmp_sym
= left_sym
;
1104 char *tmp_name
= left
;
1105 struct var_sym_list
*tmp_vsl
= left_vsl
;
1106 struct expression
*tmp_expr
= left_expr
;
1109 left_sym
= right_sym
;
1110 left_vsl
= right_vsl
;
1111 left_expr
= right_expr
;
1113 right_sym
= tmp_sym
;
1114 right_vsl
= tmp_vsl
;
1115 right_expr
= tmp_expr
;
1116 op
= flip_comparison(op
);
1117 false_op
= flip_comparison(false_op
);
1120 orig_comparison
= get_comparison(left_expr
, right_expr
);
1121 op
= filter_comparison(orig_comparison
, op
);
1122 false_op
= filter_comparison(orig_comparison
, false_op
);
1124 snprintf(state_name
, sizeof(state_name
), "%s vs %s", left
, right
);
1125 true_state
= alloc_compare_state(
1126 left_expr
, left
, left_vsl
,
1128 right_expr
, right
, right_vsl
);
1129 false_state
= alloc_compare_state(
1130 left_expr
, left
, left_vsl
,
1132 right_expr
, right
, right_vsl
);
1134 pre_stree
= clone_stree(__get_cur_stree());
1135 update_tf_data(pre_stree
, left_expr
, left
, left_vsl
, right_expr
, right
, right_vsl
, op
, false_op
);
1136 free_stree(&pre_stree
);
1138 set_true_false_states(compare_id
, state_name
, NULL
, true_state
, false_state
);
1139 __compare_param_limit_hook(left_expr
, right_expr
, state_name
, true_state
, false_state
);
1140 save_link(left_expr
, state_name
);
1141 save_link(right_expr
, state_name
);
1144 *_false_state
= false_state
;
1146 *_state_name
= state_name
;
1153 void __comparison_match_condition(struct expression
*expr
)
1155 struct expression
*left
, *right
, *new_left
, *new_right
, *tmp
;
1156 struct smatch_state
*false_state
= NULL
;
1157 char *state_name
= NULL
;
1160 if (expr
->type
!= EXPR_COMPARE
)
1163 handle_comparison(expr
->left
, expr
->op
, expr
->right
, &state_name
, &false_state
);
1164 if (false_state
&& state_name
)
1165 handle_for_loops(expr
, state_name
, false_state
);
1167 left
= strip_parens(expr
->left
);
1168 right
= strip_parens(expr
->right
);
1170 if (left
->type
== EXPR_BINOP
&& left
->op
== '+') {
1171 new_left
= left
->left
;
1172 new_right
= binop_expression(right
, '-', left
->right
);
1173 handle_comparison(new_left
, expr
->op
, new_right
, NULL
, NULL
);
1175 new_left
= left
->right
;
1176 new_right
= binop_expression(right
, '-', left
->left
);
1177 handle_comparison(new_left
, expr
->op
, new_right
, NULL
, NULL
);
1182 left
= strip_parens(expr
->left
);
1183 right
= strip_parens(expr
->right
);
1184 if (get_last_expr_from_expression_stmt(expr
->left
)) {
1185 left
= get_last_expr_from_expression_stmt(expr
->left
);
1188 if (get_last_expr_from_expression_stmt(expr
->right
)) {
1189 right
= get_last_expr_from_expression_stmt(expr
->right
);
1197 while ((tmp
= get_assigned_expr(left
))) {
1200 left
= strip_expr(tmp
);
1203 while ((tmp
= get_assigned_expr(right
))) {
1206 right
= strip_expr(tmp
);
1209 handle_comparison(left
, expr
->op
, right
, NULL
, NULL
);
1212 static void add_comparison_var_sym(
1213 struct expression
*left_expr
,
1214 const char *left_name
, struct var_sym_list
*left_vsl
,
1216 struct expression
*right_expr
,
1217 const char *right_name
, struct var_sym_list
*right_vsl
)
1219 struct smatch_state
*state
;
1221 char state_name
[256];
1223 if (strcmp(left_name
, right_name
) > 0) {
1224 struct expression
*tmp_expr
= left_expr
;
1225 const char *tmp_name
= left_name
;
1226 struct var_sym_list
*tmp_vsl
= left_vsl
;
1228 left_expr
= right_expr
;
1229 left_name
= right_name
;
1230 left_vsl
= right_vsl
;
1231 right_expr
= tmp_expr
;
1232 right_name
= tmp_name
;
1233 right_vsl
= tmp_vsl
;
1234 comparison
= flip_comparison(comparison
);
1236 snprintf(state_name
, sizeof(state_name
), "%s vs %s", left_name
, right_name
);
1237 state
= alloc_compare_state(
1238 left_expr
, left_name
, left_vsl
,
1240 right_expr
, right_name
, right_vsl
);
1242 set_state(compare_id
, state_name
, NULL
, state
);
1244 FOR_EACH_PTR(left_vsl
, vs
) {
1245 save_link_var_sym(vs
->var
, vs
->sym
, state_name
);
1246 } END_FOR_EACH_PTR(vs
);
1247 FOR_EACH_PTR(right_vsl
, vs
) {
1248 save_link_var_sym(vs
->var
, vs
->sym
, state_name
);
1249 } END_FOR_EACH_PTR(vs
);
1252 static void add_comparison(struct expression
*left
, int comparison
, struct expression
*right
)
1254 char *left_name
= NULL
;
1255 char *right_name
= NULL
;
1256 struct symbol
*left_sym
, *right_sym
;
1257 struct var_sym_list
*left_vsl
, *right_vsl
;
1258 struct smatch_state
*state
;
1259 char state_name
[256];
1261 left_name
= chunk_to_var_sym(left
, &left_sym
);
1264 left_vsl
= expr_to_vsl(left
);
1265 right_name
= chunk_to_var_sym(right
, &right_sym
);
1268 right_vsl
= expr_to_vsl(right
);
1270 if (strcmp(left_name
, right_name
) > 0) {
1271 struct expression
*tmp_expr
= left
;
1272 struct symbol
*tmp_sym
= left_sym
;
1273 char *tmp_name
= left_name
;
1274 struct var_sym_list
*tmp_vsl
= left_vsl
;
1277 left_name
= right_name
;
1278 left_sym
= right_sym
;
1279 left_vsl
= right_vsl
;
1281 right_name
= tmp_name
;
1282 right_sym
= tmp_sym
;
1283 right_vsl
= tmp_vsl
;
1284 comparison
= flip_comparison(comparison
);
1286 snprintf(state_name
, sizeof(state_name
), "%s vs %s", left_name
, right_name
);
1287 state
= alloc_compare_state(
1288 left
, left_name
, left_vsl
,
1290 right
, right_name
, right_vsl
);
1292 set_state(compare_id
, state_name
, NULL
, state
);
1293 save_link(left
, state_name
);
1294 save_link(right
, state_name
);
1297 free_string(left_name
);
1298 free_string(right_name
);
1301 static void match_assign_add(struct expression
*expr
)
1303 struct expression
*right
;
1304 struct expression
*r_left
, *r_right
;
1305 sval_t left_tmp
, right_tmp
;
1307 right
= strip_expr(expr
->right
);
1308 r_left
= strip_expr(right
->left
);
1309 r_right
= strip_expr(right
->right
);
1311 get_absolute_min(r_left
, &left_tmp
);
1312 get_absolute_min(r_right
, &right_tmp
);
1314 if (left_tmp
.value
> 0)
1315 add_comparison(expr
->left
, '>', r_right
);
1316 else if (left_tmp
.value
== 0)
1317 add_comparison(expr
->left
, SPECIAL_GTE
, r_right
);
1319 if (right_tmp
.value
> 0)
1320 add_comparison(expr
->left
, '>', r_left
);
1321 else if (right_tmp
.value
== 0)
1322 add_comparison(expr
->left
, SPECIAL_GTE
, r_left
);
1325 static void match_assign_sub(struct expression
*expr
)
1327 struct expression
*right
;
1328 struct expression
*r_left
, *r_right
;
1332 right
= strip_expr(expr
->right
);
1333 r_left
= strip_expr(right
->left
);
1334 r_right
= strip_expr(right
->right
);
1336 if (get_absolute_min(r_right
, &min
) && sval_is_negative(min
))
1339 comparison
= get_comparison(r_left
, r_right
);
1341 switch (comparison
) {
1344 if (implied_not_equal(r_right
, 0))
1345 add_comparison(expr
->left
, '>', r_left
);
1347 add_comparison(expr
->left
, SPECIAL_GTE
, r_left
);
1352 static void match_assign_divide(struct expression
*expr
)
1354 struct expression
*right
;
1355 struct expression
*r_left
, *r_right
;
1358 right
= strip_expr(expr
->right
);
1359 r_left
= strip_expr(right
->left
);
1360 r_right
= strip_expr(right
->right
);
1361 if (!get_implied_min(r_right
, &min
) || min
.value
<= 1)
1364 add_comparison(expr
->left
, '<', r_left
);
1367 static void match_binop_assign(struct expression
*expr
)
1369 struct expression
*right
;
1371 right
= strip_expr(expr
->right
);
1372 if (right
->op
== '+')
1373 match_assign_add(expr
);
1374 if (right
->op
== '-')
1375 match_assign_sub(expr
);
1376 if (right
->op
== '/')
1377 match_assign_divide(expr
);
1380 static void copy_comparisons(struct expression
*left
, struct expression
*right
)
1382 struct string_list
*links
;
1383 struct smatch_state
*state
;
1384 struct compare_data
*data
;
1385 struct symbol
*left_sym
, *right_sym
;
1386 char *left_var
= NULL
;
1387 char *right_var
= NULL
;
1388 struct var_sym_list
*left_vsl
;
1389 struct expression
*expr
;
1391 struct var_sym_list
*vsl
;
1395 left_var
= chunk_to_var_sym(left
, &left_sym
);
1398 left_vsl
= expr_to_vsl(left
);
1399 right_var
= chunk_to_var_sym(right
, &right_sym
);
1403 state
= get_state(link_id
, right_var
, right_sym
);
1406 links
= state
->data
;
1408 FOR_EACH_PTR(links
, tmp
) {
1409 state
= get_state(compare_id
, tmp
, NULL
);
1410 if (!state
|| !state
->data
)
1413 comparison
= data
->comparison
;
1415 var
= data
->right_var
;
1416 vsl
= data
->right_vsl
;
1417 if (strcmp(var
, right_var
) == 0) {
1419 var
= data
->left_var
;
1420 vsl
= data
->left_vsl
;
1421 comparison
= flip_comparison(comparison
);
1423 add_comparison_var_sym(left
, left_var
, left_vsl
, comparison
, expr
, var
, vsl
);
1424 } END_FOR_EACH_PTR(tmp
);
1427 free_string(right_var
);
1430 static void match_assign(struct expression
*expr
)
1432 struct expression
*right
;
1434 if (expr
->op
!= '=')
1436 if (__in_fake_assign
|| outside_of_function())
1439 if (is_struct(expr
->left
))
1442 copy_comparisons(expr
->left
, expr
->right
);
1443 add_comparison(expr
->left
, SPECIAL_EQUAL
, expr
->right
);
1445 right
= strip_expr(expr
->right
);
1446 if (right
->type
== EXPR_BINOP
)
1447 match_binop_assign(expr
);
1450 int get_comparison_strings(const char *one
, const char *two
)
1453 struct smatch_state
*state
;
1460 if (strcmp(one
, two
) == 0)
1461 return SPECIAL_EQUAL
;
1463 if (strcmp(one
, two
) > 0) {
1464 const char *tmp
= one
;
1471 snprintf(buf
, sizeof(buf
), "%s vs %s", one
, two
);
1472 state
= get_state(compare_id
, buf
, NULL
);
1474 ret
= state_to_comparison(state
);
1477 ret
= flip_comparison(ret
);
1482 int get_comparison(struct expression
*a
, struct expression
*b
)
1488 a
= strip_parens(a
);
1489 b
= strip_parens(b
);
1491 move_plus_to_minus(&a
, &b
);
1493 one
= chunk_to_var(a
);
1496 two
= chunk_to_var(b
);
1500 ret
= get_comparison_strings(one
, two
);
1504 if (is_plus_one(a
) || is_minus_one(a
)) {
1506 one
= chunk_to_var(a
->left
);
1507 ret
= get_comparison_strings(one
, two
);
1508 } else if (is_plus_one(b
) || is_minus_one(b
)) {
1510 two
= chunk_to_var(b
->left
);
1511 ret
= get_comparison_strings(one
, two
);
1517 if ((is_plus_one(a
) || is_minus_one(b
)) && ret
== '<')
1519 else if ((is_minus_one(a
) || is_plus_one(b
)) && ret
== '>')
1530 int possible_comparison(struct expression
*a
, int comparison
, struct expression
*b
)
1536 struct sm_state
*sm
;
1539 one
= chunk_to_var(a
);
1542 two
= chunk_to_var(b
);
1547 if (strcmp(one
, two
) == 0 && comparison
== SPECIAL_EQUAL
) {
1552 if (strcmp(one
, two
) > 0) {
1557 comparison
= flip_comparison(comparison
);
1560 snprintf(buf
, sizeof(buf
), "%s vs %s", one
, two
);
1561 sm
= get_sm_state(compare_id
, buf
, NULL
);
1565 FOR_EACH_PTR(sm
->possible
, sm
) {
1566 if (!sm
->state
->data
)
1568 saved
= ((struct compare_data
*)sm
->state
->data
)->comparison
;
1569 if (saved
== comparison
)
1571 if (comparison
== SPECIAL_EQUAL
&&
1572 (saved
== SPECIAL_LTE
||
1573 saved
== SPECIAL_GTE
||
1574 saved
== SPECIAL_UNSIGNED_LTE
||
1575 saved
== SPECIAL_UNSIGNED_GTE
))
1579 } END_FOR_EACH_PTR(sm
);
1588 struct state_list
*get_all_comparisons(struct expression
*expr
)
1590 struct smatch_state
*state
;
1591 struct string_list
*links
;
1592 struct state_list
*ret
= NULL
;
1593 struct sm_state
*sm
;
1596 state
= get_state_chunk(link_id
, expr
);
1599 links
= state
->data
;
1601 FOR_EACH_PTR(links
, tmp
) {
1602 sm
= get_sm_state(compare_id
, tmp
, NULL
);
1605 // FIXME have to compare name with vsl
1606 add_ptr_list(&ret
, sm
);
1607 } END_FOR_EACH_PTR(tmp
);
1612 struct state_list
*get_all_possible_equal_comparisons(struct expression
*expr
)
1614 struct smatch_state
*state
;
1615 struct string_list
*links
;
1616 struct state_list
*ret
= NULL
;
1617 struct sm_state
*sm
;
1620 state
= get_state_chunk(link_id
, expr
);
1623 links
= state
->data
;
1625 FOR_EACH_PTR(links
, tmp
) {
1626 sm
= get_sm_state(compare_id
, tmp
, NULL
);
1629 if (!strchr(sm
->state
->name
, '='))
1631 if (strcmp(sm
->state
->name
, "!=") == 0)
1633 add_ptr_list(&ret
, sm
);
1634 } END_FOR_EACH_PTR(tmp
);
1639 struct state_list
*get_all_possible_not_equal_comparisons(struct expression
*expr
)
1641 struct smatch_state
*state
;
1642 struct string_list
*links
;
1643 struct state_list
*ret
= NULL
;
1644 struct sm_state
*sm
;
1645 struct sm_state
*possible
;
1650 state
= get_state_chunk(link_id
, expr
);
1653 links
= state
->data
;
1655 FOR_EACH_PTR(links
, link
) {
1656 sm
= get_sm_state(compare_id
, link
, NULL
);
1659 FOR_EACH_PTR(sm
->possible
, possible
) {
1660 if (strcmp(possible
->state
->name
, "!=") != 0)
1662 add_ptr_list(&ret
, sm
);
1664 } END_FOR_EACH_PTR(link
);
1665 } END_FOR_EACH_PTR(link
);
1670 static void update_links_from_call(struct expression
*left
,
1672 struct expression
*right
)
1674 struct string_list
*links
;
1675 struct smatch_state
*state
;
1676 struct compare_data
*data
;
1677 struct symbol
*left_sym
, *right_sym
;
1678 char *left_var
= NULL
;
1679 char *right_var
= NULL
;
1680 struct var_sym_list
*left_vsl
;
1681 struct expression
*expr
;
1683 struct var_sym_list
*vsl
;
1687 left_var
= chunk_to_var_sym(left
, &left_sym
);
1690 left_vsl
= expr_to_vsl(left
);
1691 right_var
= chunk_to_var_sym(right
, &right_sym
);
1695 state
= get_state(link_id
, right_var
, right_sym
);
1698 links
= state
->data
;
1700 FOR_EACH_PTR(links
, tmp
) {
1701 state
= get_state(compare_id
, tmp
, NULL
);
1702 if (!state
|| !state
->data
)
1705 comparison
= data
->comparison
;
1707 var
= data
->right_var
;
1708 vsl
= data
->right_vsl
;
1709 if (strcmp(var
, right_var
) == 0) {
1711 var
= data
->left_var
;
1712 vsl
= data
->left_vsl
;
1713 comparison
= flip_comparison(comparison
);
1715 comparison
= combine_comparisons(left_compare
, comparison
);
1718 add_comparison_var_sym(left
, left_var
, left_vsl
, comparison
, expr
, var
, vsl
);
1719 } END_FOR_EACH_PTR(tmp
);
1722 free_string(right_var
);
1725 void __add_return_comparison(struct expression
*call
, const char *range
)
1727 struct expression
*arg
;
1731 if (!str_to_comparison_arg(range
, call
, &comparison
, &arg
))
1733 snprintf(buf
, sizeof(buf
), "%s", show_special(comparison
));
1734 update_links_from_call(call
, comparison
, arg
);
1735 add_comparison(call
, comparison
, arg
);
1738 void __add_comparison_info(struct expression
*expr
, struct expression
*call
, const char *range
)
1740 copy_comparisons(expr
, call
);
1743 static char *get_mask_comparison(struct expression
*expr
, int ignore
)
1745 struct expression
*tmp
, *right
;
1749 /* The return value for "return foo & param;" is <= param */
1752 while ((tmp
= get_assigned_expr(expr
))) {
1753 expr
= strip_expr(tmp
);
1758 if (expr
->type
!= EXPR_BINOP
|| expr
->op
!= '&')
1761 right
= strip_expr(expr
->right
);
1762 param
= get_param_num(right
);
1764 if (param
== ignore
)
1767 snprintf(buf
, sizeof(buf
), "[<=$%d]", param
);
1768 return alloc_sname(buf
);
1771 static char *range_comparison_to_param_helper(struct expression
*expr
, char starts_with
, int ignore
)
1773 struct symbol
*param
;
1776 char *ret_str
= NULL
;
1783 var
= chunk_to_var(expr
);
1788 FOR_EACH_PTR(cur_func_sym
->ctype
.base_type
->arguments
, param
) {
1794 snprintf(buf
, sizeof(buf
), "%s orig", param
->ident
->name
);
1795 compare
= get_comparison_strings(var
, buf
);
1798 if (show_special(compare
)[0] != starts_with
)
1800 snprintf(buf
, sizeof(buf
), "[%s$%d]", show_special(compare
), i
);
1801 ret_str
= alloc_sname(buf
);
1803 } END_FOR_EACH_PTR(param
);
1812 if (starts_with
== '<')
1813 ret_str
= get_mask_comparison(expr
, ignore
);
1817 char *name_sym_to_param_comparison(const char *name
, struct symbol
*sym
)
1819 struct symbol
*param
;
1825 FOR_EACH_PTR(cur_func_sym
->ctype
.base_type
->arguments
, param
) {
1829 snprintf(buf
, sizeof(buf
), "%s orig", param
->ident
->name
);
1830 compare
= get_comparison_strings(name
, buf
);
1833 snprintf(buf
, sizeof(buf
), "[%s$%d]", show_special(compare
), i
);
1834 return alloc_sname(buf
);
1835 } END_FOR_EACH_PTR(param
);
1840 char *expr_equal_to_param(struct expression
*expr
, int ignore
)
1842 return range_comparison_to_param_helper(expr
, '=', ignore
);
1845 char *expr_lte_to_param(struct expression
*expr
, int ignore
)
1847 return range_comparison_to_param_helper(expr
, '<', ignore
);
1850 char *expr_param_comparison(struct expression
*expr
, int ignore
)
1852 struct symbol
*param
;
1855 char *ret_str
= NULL
;
1859 var
= chunk_to_var(expr
);
1864 FOR_EACH_PTR(cur_func_sym
->ctype
.base_type
->arguments
, param
) {
1870 snprintf(buf
, sizeof(buf
), "%s orig", param
->ident
->name
);
1871 compare
= get_comparison_strings(var
, buf
);
1874 snprintf(buf
, sizeof(buf
), "[%s$%d]", show_special(compare
), i
);
1875 ret_str
= alloc_sname(buf
);
1877 } END_FOR_EACH_PTR(param
);
1884 char *get_printed_param_name(struct expression
*call
, const char *param_name
, struct symbol
*param_sym
)
1886 struct expression
*arg
;
1889 static char buf
[256];
1894 FOR_EACH_PTR(call
->args
, arg
) {
1897 name
= expr_to_var_sym(arg
, &sym
);
1900 if (sym
!= param_sym
)
1904 if (strncmp(name
, param_name
, len
) != 0)
1906 if (param_name
[len
] == '\0') {
1907 snprintf(buf
, sizeof(buf
), "$%d", i
);
1910 if (param_name
[len
] != '-')
1912 snprintf(buf
, sizeof(buf
), "$%d%s", i
, param_name
+ len
);
1914 } END_FOR_EACH_PTR(arg
);
1919 static void match_call_info(struct expression
*expr
)
1921 struct expression
*arg
;
1922 struct smatch_state
*state
;
1923 struct sm_state
*sm
;
1924 struct compare_data
*data
;
1926 struct string_list
*links
;
1928 const char *right_name
;
1934 FOR_EACH_PTR(expr
->args
, arg
) {
1937 state
= get_state_chunk(link_id
, arg
);
1941 links
= state
->data
;
1942 FOR_EACH_PTR(links
, link
) {
1943 struct var_sym_list
*right_vsl
;
1944 struct var_sym
*right_vs
;
1947 if (strstr(link
, " orig"))
1949 sm
= get_sm_state(compare_id
, link
, NULL
);
1952 data
= sm
->state
->data
;
1953 if (!data
|| !data
->comparison
)
1955 arg_name
= expr_to_var(arg
);
1960 if (strcmp(data
->left_var
, arg_name
) == 0) {
1961 comparison
= data
->comparison
;
1962 right_name
= data
->right_var
;
1963 right_vsl
= data
->right_vsl
;
1964 } else if (strcmp(data
->right_var
, arg_name
) == 0) {
1965 comparison
= flip_comparison(data
->comparison
);
1966 right_name
= data
->left_var
;
1967 right_vsl
= data
->left_vsl
;
1969 if (!right_vsl
|| ptr_list_size((struct ptr_list
*)right_vsl
) != 1)
1972 right_vs
= first_ptr_list((struct ptr_list
*)right_vsl
);
1973 if (strcmp(right_vs
->var
, right_name
) != 0)
1975 right_name
= get_printed_param_name(expr
, right_vs
->var
, right_vs
->sym
);
1978 snprintf(info_buf
, sizeof(info_buf
), "%s %s", show_special(comparison
), right_name
);
1979 sql_insert_caller_info(expr
, PARAM_COMPARE
, i
, "$", info_buf
);
1982 free_string(arg_name
);
1983 } END_FOR_EACH_PTR(link
);
1984 } END_FOR_EACH_PTR(arg
);
1987 static void struct_member_callback(struct expression
*call
, int param
, char *printed_name
, struct sm_state
*link_sm
)
1989 struct sm_state
*compare_sm
;
1990 struct string_list
*links
;
1992 struct compare_data
*data
;
1993 struct var_sym
*left
, *right
;
1994 static char info_buf
[256];
1995 const char *right_name
;
1997 if (strstr(printed_name
, " orig"))
2000 links
= link_sm
->state
->data
;
2001 FOR_EACH_PTR(links
, link
) {
2002 compare_sm
= get_sm_state(compare_id
, link
, NULL
);
2005 data
= compare_sm
->state
->data
;
2006 if (!data
|| !data
->comparison
)
2009 if (ptr_list_size((struct ptr_list
*)data
->left_vsl
) != 1 ||
2010 ptr_list_size((struct ptr_list
*)data
->right_vsl
) != 1)
2012 left
= first_ptr_list((struct ptr_list
*)data
->left_vsl
);
2013 right
= first_ptr_list((struct ptr_list
*)data
->right_vsl
);
2014 if (left
->sym
== right
->sym
&&
2015 strcmp(left
->var
, right
->var
) == 0)
2018 * Both parameters link to this comparison so only
2019 * record the first one.
2021 if (left
->sym
!= link_sm
->sym
||
2022 strcmp(left
->var
, link_sm
->name
) != 0)
2025 right_name
= get_printed_param_name(call
, right
->var
, right
->sym
);
2028 snprintf(info_buf
, sizeof(info_buf
), "%s %s", show_special(data
->comparison
), right_name
);
2029 sql_insert_caller_info(call
, PARAM_COMPARE
, param
, printed_name
, info_buf
);
2030 } END_FOR_EACH_PTR(link
);
2033 static void print_return_value_comparison(int return_id
, char *return_ranges
, struct expression
*expr
)
2036 const char *tmp_name
;
2042 * TODO: This only prints == comparisons. That's probably the most
2043 * useful comparison because == max has lots of implications. But it
2044 * would be good to capture the rest as well.
2046 * This information is already in the DB but it's in the parameter math
2047 * bits and it's awkward to use it. This is is the simpler, possibly
2048 * cleaner way, but not necessarily the best, I don't know.
2053 name
= expr_to_var_sym(expr
, &sym
);
2057 param
= get_param_num_from_sym(sym
);
2060 if (param_was_set_var_sym(name
, sym
))
2063 tmp_name
= get_param_name_var_sym(name
, sym
);
2067 snprintf(info_buf
, sizeof(info_buf
), "== $%d%s", param
, tmp_name
+ 1);
2068 sql_insert_return_states(return_id
, return_ranges
,
2069 PARAM_COMPARE
, -1, "$", info_buf
);
2074 static void print_return_comparison(int return_id
, char *return_ranges
, struct expression
*expr
)
2076 struct sm_state
*tmp
;
2077 struct string_list
*links
;
2079 struct sm_state
*sm
;
2080 struct compare_data
*data
;
2081 struct var_sym
*left
, *right
;
2082 int left_param
, right_param
;
2084 char right_buf
[256];
2086 const char *tmp_name
;
2088 print_return_value_comparison(return_id
, return_ranges
, expr
);
2090 FOR_EACH_MY_SM(link_id
, __get_cur_stree(), tmp
) {
2091 if (get_param_num_from_sym(tmp
->sym
) < 0)
2093 links
= tmp
->state
->data
;
2094 FOR_EACH_PTR(links
, link
) {
2095 sm
= get_sm_state(compare_id
, link
, NULL
);
2098 data
= sm
->state
->data
;
2099 if (!data
|| !data
->comparison
)
2101 if (ptr_list_size((struct ptr_list
*)data
->left_vsl
) != 1 ||
2102 ptr_list_size((struct ptr_list
*)data
->right_vsl
) != 1)
2104 left
= first_ptr_list((struct ptr_list
*)data
->left_vsl
);
2105 right
= first_ptr_list((struct ptr_list
*)data
->right_vsl
);
2106 if (left
->sym
== right
->sym
&&
2107 strcmp(left
->var
, right
->var
) == 0)
2110 * Both parameters link to this comparison so only
2111 * record the first one.
2113 if (left
->sym
!= tmp
->sym
||
2114 strcmp(left
->var
, tmp
->name
) != 0)
2117 if (strstr(right
->var
, " orig"))
2120 left_param
= get_param_num_from_sym(left
->sym
);
2121 right_param
= get_param_num_from_sym(right
->sym
);
2122 if (left_param
< 0 || right_param
< 0)
2125 tmp_name
= get_param_name_var_sym(left
->var
, left
->sym
);
2128 snprintf(left_buf
, sizeof(left_buf
), "%s", tmp_name
);
2130 tmp_name
= get_param_name_var_sym(right
->var
, right
->sym
);
2131 if (!tmp_name
|| tmp_name
[0] != '$')
2133 snprintf(right_buf
, sizeof(right_buf
), "$%d%s", right_param
, tmp_name
+ 1);
2136 * FIXME: this should reject $ type variables (as
2137 * opposed to $->foo type). Those should come from
2138 * smatch_param_compare_limit.c.
2141 snprintf(info_buf
, sizeof(info_buf
), "%s %s", show_special(data
->comparison
), right_buf
);
2142 sql_insert_return_states(return_id
, return_ranges
,
2143 PARAM_COMPARE
, left_param
, left_buf
, info_buf
);
2144 } END_FOR_EACH_PTR(link
);
2146 } END_FOR_EACH_SM(tmp
);
2149 static int parse_comparison(char **value
, int *op
)
2157 if (**value
== '=') {
2165 *op
= SPECIAL_EQUAL
;
2170 *op
= SPECIAL_NOTEQUAL
;
2174 if (**value
== '=') {
2183 if (**value
!= ' ') {
2184 sm_msg("internal error parsing comparison. %s", *value
);
2192 static int split_op_param_key(char *value
, int *op
, int *param
, char **key
)
2194 static char buf
[256];
2197 if (!parse_comparison(&value
, op
))
2200 snprintf(buf
, sizeof(buf
), value
);
2207 if (*param
< 0 || *param
> 99)
2219 static void db_return_comparison(struct expression
*expr
, int left_param
, char *key
, char *value
)
2221 struct expression
*left_arg
, *right_arg
;
2222 char *left_name
= NULL
;
2223 struct symbol
*left_sym
;
2224 char *right_name
= NULL
;
2225 struct symbol
*right_sym
;
2229 struct var_sym_list
*left_vsl
= NULL
, *right_vsl
= NULL
;
2231 if (left_param
== -1) {
2232 if (expr
->type
!= EXPR_ASSIGNMENT
)
2234 left_arg
= strip_expr(expr
->left
);
2236 while (expr
->type
== EXPR_ASSIGNMENT
)
2237 expr
= strip_expr(expr
->right
);
2238 if (expr
->type
!= EXPR_CALL
)
2241 while (expr
->type
== EXPR_ASSIGNMENT
)
2242 expr
= strip_expr(expr
->right
);
2243 if (expr
->type
!= EXPR_CALL
)
2246 left_arg
= get_argument_from_call_expr(expr
->args
, left_param
);
2251 if (!split_op_param_key(value
, &op
, &right_param
, &right_key
))
2254 right_arg
= get_argument_from_call_expr(expr
->args
, right_param
);
2258 left_name
= get_variable_from_key(left_arg
, key
, &left_sym
);
2259 if (!left_name
|| !left_sym
)
2262 right_name
= get_variable_from_key(right_arg
, right_key
, &right_sym
);
2263 if (!right_name
|| !right_sym
)
2266 add_var_sym(&left_vsl
, left_name
, left_sym
);
2267 add_var_sym(&right_vsl
, right_name
, right_sym
);
2269 add_comparison_var_sym(NULL
, left_name
, left_vsl
, op
, NULL
, right_name
, right_vsl
);
2272 free_string(left_name
);
2273 free_string(right_name
);
2276 int param_compare_limit_is_impossible(struct expression
*expr
, int left_param
, char *left_key
, char *value
)
2278 struct smatch_state
*state
;
2279 char *left_name
= NULL
;
2280 char *right_name
= NULL
;
2281 struct symbol
*left_sym
, *right_sym
;
2282 struct expression
*left_arg
, *right_arg
;
2289 while (expr
->type
== EXPR_ASSIGNMENT
)
2290 expr
= strip_expr(expr
->right
);
2291 if (expr
->type
!= EXPR_CALL
)
2294 if (!split_op_param_key(value
, &op
, &right_param
, &right_key
))
2297 left_arg
= get_argument_from_call_expr(expr
->args
, left_param
);
2301 right_arg
= get_argument_from_call_expr(expr
->args
, right_param
);
2305 left_name
= get_variable_from_key(left_arg
, left_key
, &left_sym
);
2306 right_name
= get_variable_from_key(right_arg
, right_key
, &right_sym
);
2307 if (!left_name
|| !right_name
)
2310 snprintf(buf
, sizeof(buf
), "%s vs %s", left_name
, right_name
);
2311 state
= get_state(compare_id
, buf
, NULL
);
2314 state_op
= state_to_comparison(state
);
2318 if (!filter_comparison(remove_unsigned_from_comparison(state_op
), op
))
2321 free_string(left_name
);
2322 free_string(right_name
);
2326 int impossibly_high_comparison(struct expression
*expr
)
2328 struct smatch_state
*link_state
;
2329 struct sm_state
*sm
;
2330 struct string_list
*links
;
2332 struct compare_data
*data
;
2334 link_state
= get_state_expr(link_id
, expr
);
2336 if (expr
->type
== EXPR_BINOP
&&
2337 (impossibly_high_comparison(expr
->left
) ||
2338 impossibly_high_comparison(expr
->right
)))
2343 links
= link_state
->data
;
2344 FOR_EACH_PTR(links
, link
) {
2345 sm
= get_sm_state(compare_id
, link
, NULL
);
2348 data
= sm
->state
->data
;
2351 if (!possibly_true(data
->left
, data
->comparison
, data
->right
))
2353 } END_FOR_EACH_PTR(link
);
2358 static void free_data(struct symbol
*sym
)
2362 clear_compare_data_alloc();
2365 void register_comparison(int id
)
2368 add_hook(&save_start_states
, AFTER_DEF_HOOK
);
2369 add_unmatched_state_hook(compare_id
, unmatched_comparison
);
2370 add_merge_hook(compare_id
, &merge_compare_states
);
2371 add_hook(&free_data
, AFTER_FUNC_HOOK
);
2372 add_hook(&match_call_info
, FUNCTION_CALL_HOOK
);
2373 add_split_return_callback(&print_return_comparison
);
2375 select_return_states_hook(PARAM_COMPARE
, &db_return_comparison
);
2378 void register_comparison_late(int id
)
2380 add_hook(&match_assign
, ASSIGNMENT_HOOK
);
2383 void register_comparison_links(int id
)
2386 add_merge_hook(link_id
, &merge_links
);
2387 add_modification_hook(link_id
, &match_modify
);
2389 add_member_info_callback(link_id
, struct_member_callback
);
2392 void register_comparison_inc_dec(int id
)
2395 add_modification_hook_late(inc_dec_id
, &iter_modify
);
2398 void register_comparison_inc_dec_links(int id
)
2400 inc_dec_link_id
= id
;
2401 set_up_link_functions(inc_dec_id
, inc_dec_link_id
);
2404 static void filter_by_sm(struct sm_state
*sm
, int op
,
2405 struct state_list
**true_stack
,
2406 struct state_list
**false_stack
)
2408 struct compare_data
*data
;
2414 data
= sm
->state
->data
;
2417 filter_by_sm(sm
->left
, op
, true_stack
, false_stack
);
2418 filter_by_sm(sm
->right
, op
, true_stack
, false_stack
);
2423 if (data
->comparison
&&
2424 data
->comparison
== filter_comparison(data
->comparison
, op
))
2427 if (data
->comparison
&&
2428 data
->comparison
== filter_comparison(data
->comparison
, negate_comparison(op
)))
2432 add_ptr_list(true_stack
, sm
);
2434 add_ptr_list(false_stack
, sm
);
2437 filter_by_sm(sm
->left
, op
, true_stack
, false_stack
);
2438 filter_by_sm(sm
->right
, op
, true_stack
, false_stack
);
2442 struct sm_state
*comparison_implication_hook(struct expression
*expr
,
2443 struct state_list
**true_stack
,
2444 struct state_list
**false_stack
)
2446 struct sm_state
*sm
;
2449 static char buf
[256];
2451 if (expr
->type
!= EXPR_COMPARE
)
2456 left
= expr_to_var(expr
->left
);
2457 right
= expr_to_var(expr
->right
);
2458 if (!left
|| !right
) {
2464 if (strcmp(left
, right
) > 0) {
2469 op
= flip_comparison(op
);
2472 snprintf(buf
, sizeof(buf
), "%s vs %s", left
, right
);
2473 sm
= get_sm_state(compare_id
, buf
, NULL
);
2479 filter_by_sm(sm
, op
, true_stack
, false_stack
);
2480 if (!*true_stack
&& !*false_stack
)