extra: foo((void *)&x) writes to x probably
[smatch.git] / smatch_extra.c
blob655366a7f17154f6e7f1ec5067a92aa160927f39
1 /*
2 * sparse/smatch_extra.c
4 * Copyright (C) 2008 Dan Carpenter.
6 * Licensed under the Open Software License version 1.1
8 */
11 * smatch_extra.c is supposed to track the value of every variable.
15 #include <stdlib.h>
16 #include <errno.h>
17 #ifndef __USE_ISOC99
18 #define __USE_ISOC99
19 #endif
20 #include <limits.h>
21 #include "parse.h"
22 #include "smatch.h"
23 #include "smatch_slist.h"
24 #include "smatch_extra.h"
26 static int my_id;
28 struct string_list *__ignored_macros = NULL;
29 static int in_warn_on_macro()
31 struct statement *stmt;
32 char *tmp;
33 char *macro;
35 stmt = last_ptr_list((struct ptr_list *)big_statement_stack);
36 macro = get_macro_name(stmt->pos);
37 if (!macro)
38 return 0;
40 FOR_EACH_PTR(__ignored_macros, tmp) {
41 if (!strcmp(tmp, macro))
42 return 1;
43 } END_FOR_EACH_PTR(tmp);
44 return 0;
47 struct sm_state *set_extra_mod(const char *name, struct symbol *sym, struct smatch_state *state)
49 if (in_warn_on_macro())
50 return NULL;
51 remove_from_equiv(name, sym);
52 return set_state(SMATCH_EXTRA, name, sym, state);
55 struct sm_state *set_extra_expr_mod(struct expression *expr, struct smatch_state *state)
57 if (in_warn_on_macro())
58 return NULL;
59 remove_from_equiv_expr(expr);
60 return set_state_expr(SMATCH_EXTRA, expr, state);
64 * This is for return_implies_state() hooks which modify a SMATCH_EXTRA state
66 void set_extra_expr_nomod(struct expression *expr, struct smatch_state *state)
68 struct relation *rel;
69 struct smatch_state *orig_state;
71 orig_state = get_state_expr(SMATCH_EXTRA, expr);
73 if (!estate_related(orig_state)) {
74 set_state_expr(SMATCH_EXTRA, expr, state);
75 return;
78 FOR_EACH_PTR(estate_related(orig_state), rel) {
79 if (option_debug_related)
80 sm_msg("updating related %s to %s", rel->name, state->name);
81 set_state(SMATCH_EXTRA, rel->name, rel->sym, state);
82 add_equiv(state, rel->name, rel->sym);
83 } END_FOR_EACH_PTR(rel);
86 static void set_extra_true_false(const char *name, struct symbol *sym,
87 struct smatch_state *true_state,
88 struct smatch_state *false_state)
90 struct relation *rel;
91 struct smatch_state *orig_state;
93 if (in_warn_on_macro())
94 return;
96 orig_state = get_state(SMATCH_EXTRA, name, sym);
98 if (!estate_related(orig_state)) {
99 set_true_false_states(SMATCH_EXTRA, name, sym, true_state, false_state);
100 return;
103 // FIXME!!!! equiv => related
104 FOR_EACH_PTR(estate_related(orig_state), rel) {
105 set_true_false_states(SMATCH_EXTRA, rel->name, rel->sym,
106 true_state, false_state);
107 if (true_state)
108 add_equiv(true_state, rel->name, rel->sym);
109 if (false_state)
110 add_equiv(false_state, rel->name, rel->sym);
111 } END_FOR_EACH_PTR(rel);
114 static void set_extra_expr_true_false(struct expression *expr,
115 struct smatch_state *true_state,
116 struct smatch_state *false_state)
118 char *name;
119 struct symbol *sym;
121 expr = strip_expr(expr);
122 name = get_variable_from_expr(expr, &sym);
123 if (!name || !sym)
124 goto free;
125 set_extra_true_false(name, sym, true_state, false_state);
126 free:
127 free_string(name);
130 struct smatch_state *filter_range(struct smatch_state *orig,
131 long long filter_min, long long filter_max)
133 struct range_list *rl;
135 if (!orig)
136 orig = extra_undefined();
138 rl = remove_range(estate_ranges(orig), filter_min, filter_max);
139 return alloc_estate_range_list(rl);
142 struct smatch_state *add_filter(struct smatch_state *orig, long long num)
144 return filter_range(orig, num, num);
147 static struct smatch_state *merge_func(const char *name, struct symbol *sym,
148 struct smatch_state *s1,
149 struct smatch_state *s2)
151 struct smatch_state *tmp;
152 struct range_list *value_ranges;
153 struct relation *rel;
154 struct relation *new;
156 value_ranges = range_list_union(estate_ranges(s1), estate_ranges(s2));
157 tmp = alloc_estate_range_list(value_ranges);
158 FOR_EACH_PTR(estate_related(s1), rel) {
159 new = get_common_relationship(s2, rel->op, rel->name, rel->sym);
160 if (new)
161 add_related(tmp, new->op, new->name, new->sym);
162 } END_FOR_EACH_PTR(rel);
163 return tmp;
166 static struct sm_state *handle_canonical_while_count_down(struct statement *loop)
168 struct expression *iter_var;
169 struct expression *condition;
170 struct sm_state *sm;
171 long long start;
173 condition = strip_expr(loop->iterator_pre_condition);
174 if (!condition)
175 return NULL;
176 if (condition->type != EXPR_PREOP && condition->type != EXPR_POSTOP)
177 return NULL;
178 if (condition->op != SPECIAL_DECREMENT)
179 return NULL;
181 iter_var = condition->unop;
182 sm = get_sm_state_expr(SMATCH_EXTRA, iter_var);
183 if (!sm)
184 return NULL;
185 if (estate_min(sm->state) < 0)
186 return NULL;
187 start = estate_max(sm->state);
188 if (start <= 0)
189 return NULL;
190 if (start != whole_range.max)
191 start--;
193 if (condition->type == EXPR_PREOP)
194 set_extra_expr_mod(iter_var, alloc_estate_range(1, start));
195 if (condition->type == EXPR_POSTOP)
196 set_extra_expr_mod(iter_var, alloc_estate_range(0, start));
197 return get_sm_state_expr(SMATCH_EXTRA, iter_var);
200 static struct sm_state *handle_canonical_for_inc(struct expression *iter_expr,
201 struct expression *condition)
203 struct expression *iter_var;
204 struct sm_state *sm;
205 long long start;
206 long long end;
208 iter_var = iter_expr->unop;
209 sm = get_sm_state_expr(SMATCH_EXTRA, iter_var);
210 if (!sm)
211 return NULL;
212 if (!estate_get_single_value(sm->state, &start))
213 return NULL;
214 if (!get_implied_value(condition->right, &end))
215 end = whole_range.max;
216 if (get_sm_state_expr(SMATCH_EXTRA, condition->left) != sm)
217 return NULL;
219 switch (condition->op) {
220 case SPECIAL_NOTEQUAL:
221 case '<':
222 if (end != whole_range.max)
223 end--;
224 break;
225 case SPECIAL_LTE:
226 break;
227 default:
228 return NULL;
230 if (end < start)
231 return NULL;
232 set_extra_expr_mod(iter_var, alloc_estate_range(start, end));
233 return get_sm_state_expr(SMATCH_EXTRA, iter_var);
236 static struct sm_state *handle_canonical_for_dec(struct expression *iter_expr,
237 struct expression *condition)
239 struct expression *iter_var;
240 struct sm_state *sm;
241 long long start;
242 long long end;
244 iter_var = iter_expr->unop;
245 sm = get_sm_state_expr(SMATCH_EXTRA, iter_var);
246 if (!sm)
247 return NULL;
248 if (!estate_get_single_value(sm->state, &start))
249 return NULL;
250 if (!get_implied_value(condition->right, &end))
251 end = whole_range.max;
252 if (get_sm_state_expr(SMATCH_EXTRA, condition->left) != sm)
253 return NULL;
255 switch (condition->op) {
256 case SPECIAL_NOTEQUAL:
257 case '>':
258 if (end != whole_range.min)
259 end++;
260 break;
261 case SPECIAL_GTE:
262 break;
263 default:
264 return NULL;
266 if (end > start)
267 return NULL;
268 set_extra_expr_mod(iter_var, alloc_estate_range(end, start));
269 return get_sm_state_expr(SMATCH_EXTRA, iter_var);
272 static struct sm_state *handle_canonical_for_loops(struct statement *loop)
274 struct expression *iter_expr;
275 struct expression *condition;
277 if (!loop->iterator_post_statement)
278 return NULL;
279 if (loop->iterator_post_statement->type != STMT_EXPRESSION)
280 return NULL;
281 iter_expr = loop->iterator_post_statement->expression;
282 if (!loop->iterator_pre_condition)
283 return NULL;
284 if (loop->iterator_pre_condition->type != EXPR_COMPARE)
285 return NULL;
286 condition = loop->iterator_pre_condition;
288 if (iter_expr->op == SPECIAL_INCREMENT)
289 return handle_canonical_for_inc(iter_expr, condition);
290 if (iter_expr->op == SPECIAL_DECREMENT)
291 return handle_canonical_for_dec(iter_expr, condition);
292 return NULL;
295 struct sm_state *__extra_handle_canonical_loops(struct statement *loop, struct state_list **slist)
297 struct sm_state *ret;
299 __push_fake_cur_slist();
300 if (!loop->iterator_post_statement)
301 ret = handle_canonical_while_count_down(loop);
302 else
303 ret = handle_canonical_for_loops(loop);
304 *slist = __pop_fake_cur_slist();
305 return ret;
308 int __iterator_unchanged(struct sm_state *sm)
310 if (!sm)
311 return 0;
312 if (get_sm_state(my_id, sm->name, sm->sym) == sm)
313 return 1;
314 return 0;
317 static void while_count_down_after(struct sm_state *sm, struct expression *condition)
319 long long after_value;
321 /* paranoid checking. prolly not needed */
322 condition = strip_expr(condition);
323 if (!condition)
324 return;
325 if (condition->type != EXPR_PREOP && condition->type != EXPR_POSTOP)
326 return;
327 if (condition->op != SPECIAL_DECREMENT)
328 return;
329 after_value = estate_min(sm->state);
330 after_value--;
331 set_extra_mod(sm->name, sm->sym, alloc_estate(after_value));
334 void __extra_pre_loop_hook_after(struct sm_state *sm,
335 struct statement *iterator,
336 struct expression *condition)
338 struct expression *iter_expr;
339 char *name;
340 struct symbol *sym;
341 long long value;
342 int left = 0;
343 struct smatch_state *state;
344 long long min, max;
346 if (!iterator) {
347 while_count_down_after(sm, condition);
348 return;
351 iter_expr = iterator->expression;
353 if (condition->type != EXPR_COMPARE)
354 return;
355 if (!get_value(condition->left, &value)) {
356 if (!get_value(condition->right, &value))
357 return;
358 left = 1;
360 if (left)
361 name = get_variable_from_expr(condition->left, &sym);
362 else
363 name = get_variable_from_expr(condition->right, &sym);
364 if (!name || !sym)
365 goto free;
366 if (sym != sm->sym || strcmp(name, sm->name))
367 goto free;
368 state = get_state(my_id, name, sym);
369 min = estate_min(state);
370 max = estate_max(state);
371 if (iter_expr->op == SPECIAL_INCREMENT &&
372 min != whole_range.min &&
373 max == whole_range.max) {
374 set_extra_mod(name, sym, alloc_estate(min));
375 } else if (min == whole_range.min && max != whole_range.max) {
376 set_extra_mod(name, sym, alloc_estate(max));
378 free:
379 free_string(name);
380 return;
383 static struct smatch_state *unmatched_state(struct sm_state *sm)
385 return extra_undefined();
388 static void match_function_call(struct expression *expr)
390 struct expression *arg;
391 struct expression *tmp;
393 FOR_EACH_PTR(expr->args, arg) {
394 tmp = strip_expr(arg);
395 if (tmp->type == EXPR_PREOP && tmp->op == '&') {
396 remove_from_equiv_expr(tmp->unop);
397 set_state_expr(SMATCH_EXTRA, tmp->unop, extra_undefined());
399 } END_FOR_EACH_PTR(arg);
402 static void match_assign(struct expression *expr)
404 struct expression *left;
405 struct expression *right;
406 struct symbol *right_sym;
407 char *right_name;
408 struct symbol *sym;
409 char *name;
410 long long value;
411 int known;
412 long long min = whole_range.min;
413 long long max = whole_range.max;
414 long long tmp;
416 if (__is_condition_assign(expr))
417 return;
418 left = strip_expr(expr->left);
419 name = get_variable_from_expr(left, &sym);
420 if (!name)
421 return;
422 right = strip_parens(expr->right);
423 while (right->type == EXPR_ASSIGNMENT && right->op == '=')
424 right = strip_parens(right->left);
426 if (expr->op == '=' && right->type == EXPR_CALL)
427 return; /* these are handled in match_call_assign() */
429 right_name = get_variable_from_expr(right, &right_sym);
430 if (expr->op == '=' && right_name && right_sym) {
431 set_equiv(left, right);
432 goto free;
435 known = get_implied_value(right, &value);
436 switch (expr->op) {
437 case '=': {
438 struct range_list *rl = NULL;
440 if (get_implied_range_list(right, &rl)) {
441 set_extra_mod(name, sym, alloc_estate_range_list(rl));
442 goto free;
445 if (expr_unsigned(right))
446 min = 0;
447 break;
449 case SPECIAL_ADD_ASSIGN:
450 if (get_implied_min(left, &tmp)) {
451 if (known)
452 min = tmp + value;
453 else
454 min = tmp;
456 if (!inside_loop() && known && get_implied_max(left, &tmp))
457 max = tmp + value;
458 break;
459 case SPECIAL_SUB_ASSIGN:
460 if (get_implied_max(left, &tmp)) {
461 if (known)
462 max = tmp - value;
463 else
464 max = tmp;
466 if (!inside_loop() && known && get_implied_min(left, &tmp))
467 min = tmp - value;
468 break;
470 set_extra_mod(name, sym, alloc_estate_range(min, max));
471 free:
472 free_string(right_name);
473 free_string(name);
476 static void reset_struct_members(const char *name, struct symbol *sym, struct expression *expr, void *unused)
478 struct state_list *slist;
479 struct sm_state *tmp;
480 int len;
482 len = strlen(name);
483 slist = get_all_states(SMATCH_EXTRA);
484 FOR_EACH_PTR(slist, tmp) {
485 if (sym != tmp->sym)
486 continue;
487 if (strncmp(name, tmp->name, len))
488 continue;
489 if (tmp->name[len] != '-' && tmp->name[len] != '.')
490 continue;
491 set_extra_mod(tmp->name, tmp->sym, extra_undefined());
492 } END_FOR_EACH_PTR(tmp);
495 static struct smatch_state *increment_state(struct smatch_state *state)
497 long long min = estate_min(state);
498 long long max = estate_max(state);
500 if (inside_loop())
501 max = whole_range.max;
503 if (min != whole_range.min)
504 min++;
505 if (max != whole_range.max)
506 max++;
507 return alloc_estate_range(min, max);
510 static struct smatch_state *decrement_state(struct smatch_state *state)
512 long long min = estate_min(state);
513 long long max = estate_max(state);
515 if (inside_loop())
516 min = whole_range.min;
518 if (min != whole_range.min)
519 min--;
520 if (max != whole_range.max)
521 max--;
522 return alloc_estate_range(min, max);
525 static void unop_expr(struct expression *expr)
527 struct smatch_state *state;
529 if (expr->smatch_flags & Handled)
530 return;
532 switch (expr->op) {
533 case SPECIAL_INCREMENT:
534 state = get_state_expr(SMATCH_EXTRA, expr->unop);
535 state = increment_state(state);
536 set_extra_expr_mod(expr->unop, state);
537 break;
538 case SPECIAL_DECREMENT:
539 state = get_state_expr(SMATCH_EXTRA, expr->unop);
540 state = decrement_state(state);
541 set_extra_expr_mod(expr->unop, state);
542 break;
543 default:
544 return;
548 static void delete_state_tracker(struct tracker *t)
550 remove_from_equiv(t->name, t->sym);
551 delete_state(t->owner, t->name, t->sym);
554 static void scoped_state_extra(const char *name, struct symbol *sym)
556 struct tracker *t;
558 t = alloc_tracker(SMATCH_EXTRA, name, sym);
559 add_scope_hook((scope_hook *)&delete_state_tracker, t);
562 static void match_declarations(struct symbol *sym)
564 const char *name;
566 if (sym->ident) {
567 name = sym->ident->name;
568 if (!sym->initializer) {
569 set_state(SMATCH_EXTRA, name, sym, extra_undefined());
570 scoped_state_extra(name, sym);
575 static void match_function_def(struct symbol *sym)
577 struct symbol *arg;
579 FOR_EACH_PTR(sym->ctype.base_type->arguments, arg) {
580 if (!arg->ident)
581 continue;
582 set_state(my_id, arg->ident->name, arg, extra_undefined());
583 } END_FOR_EACH_PTR(arg);
586 static int match_func_comparison(struct expression *expr)
588 struct expression *left = strip_expr(expr->left);
589 struct expression *right = strip_expr(expr->right);
590 long long val;
592 if (left->type == EXPR_CALL) {
593 if (!get_implied_value(right, &val))
594 return 1;
595 function_comparison(expr->op, left, val, 1);
596 return 1;
599 if (right->type == EXPR_CALL) {
600 if (!get_implied_value(left, &val))
601 return 1;
602 function_comparison(expr->op, right, val, 0);
603 return 1;
606 return 0;
609 static void match_comparison(struct expression *expr)
611 struct expression *left = strip_expr(expr->left);
612 struct expression *right = strip_expr(expr->right);
613 struct range_list *left_orig;
614 struct range_list *left_true;
615 struct range_list *left_false;
616 struct range_list *right_orig;
617 struct range_list *right_true;
618 struct range_list *right_false;
619 struct smatch_state *left_true_state;
620 struct smatch_state *left_false_state;
621 struct smatch_state *right_true_state;
622 struct smatch_state *right_false_state;
623 int left_postop = 0;
624 int right_postop = 0;
626 if (match_func_comparison(expr))
627 return;
629 if (left->op == SPECIAL_INCREMENT || left->op == SPECIAL_DECREMENT) {
630 if (left->type == EXPR_POSTOP) {
631 left->smatch_flags |= Handled;
632 left_postop = left->op;
634 left = strip_expr(left->unop);
637 if (right->op == SPECIAL_INCREMENT || right->op == SPECIAL_DECREMENT) {
638 if (right->type == EXPR_POSTOP) {
639 right->smatch_flags |= Handled;
640 right_postop = right->op;
642 right = strip_expr(right->unop);
645 if (!get_implied_range_list(left, &left_orig))
646 left_orig = alloc_range_list(whole_range.min, whole_range.max);
647 if (!get_implied_range_list(right, &right_orig))
648 right_orig = alloc_range_list(whole_range.min, whole_range.max);
650 left_true = clone_range_list(left_orig);
651 left_false = clone_range_list(left_orig);
652 right_true = clone_range_list(right_orig);
653 right_false = clone_range_list(right_orig);
655 switch (expr->op) {
656 case '<':
657 case SPECIAL_UNSIGNED_LT:
658 if (rl_max(right_orig) != whole_range.max)
659 left_true = remove_range(left_orig, rl_max(right_orig), whole_range.max);
660 if (rl_min(right_orig) != whole_range.min)
661 left_false = remove_range(left_orig, whole_range.min, rl_min(right_orig) - 1);
663 if (rl_min(left_orig) != whole_range.min)
664 right_true = remove_range(right_orig, whole_range.min, rl_min(left_orig));
665 if (rl_max(left_orig) != whole_range.max)
666 right_false = remove_range(right_orig, rl_max(left_orig) + 1, whole_range.max);
667 break;
668 case SPECIAL_UNSIGNED_LTE:
669 case SPECIAL_LTE:
670 if (rl_max(right_orig) != whole_range.max)
671 left_true = remove_range(left_orig, rl_max(right_orig) + 1, whole_range.max);
672 if (rl_min(right_orig) != whole_range.min)
673 left_false = remove_range(left_orig, whole_range.min, rl_min(right_orig));
675 if (rl_min(left_orig) != whole_range.min)
676 right_true = remove_range(right_orig, whole_range.min, rl_min(left_orig) - 1);
677 if (rl_max(left_orig) != whole_range.max)
678 right_false = remove_range(right_orig, rl_max(left_orig), whole_range.max);
679 break;
680 case SPECIAL_EQUAL:
681 if (rl_max(right_orig) != whole_range.max)
682 left_true = remove_range(left_true, rl_max(right_orig) + 1, whole_range.max);
683 if (rl_min(right_orig) != whole_range.min)
684 left_true = remove_range(left_true, whole_range.min, rl_min(right_orig) - 1);
685 if (rl_min(right_orig) == rl_max(right_orig))
686 left_false = remove_range(left_orig, rl_min(right_orig), rl_min(right_orig));
688 if (rl_max(left_orig) != whole_range.max)
689 right_true = remove_range(right_true, rl_max(left_orig) + 1, whole_range.max);
690 if (rl_min(left_orig) != whole_range.min)
691 right_true = remove_range(right_true, whole_range.min, rl_min(left_orig) - 1);
692 if (rl_min(left_orig) == rl_max(left_orig))
693 right_false = remove_range(right_orig, rl_min(left_orig), rl_min(left_orig));
694 break;
695 case SPECIAL_UNSIGNED_GTE:
696 case SPECIAL_GTE:
697 if (rl_min(right_orig) != whole_range.min)
698 left_true = remove_range(left_orig, whole_range.min, rl_min(right_orig) - 1);
699 if (rl_max(right_orig) != whole_range.max)
700 left_false = remove_range(left_orig, rl_max(right_orig), whole_range.max);
702 if (rl_max(left_orig) != whole_range.max)
703 right_true = remove_range(right_orig, rl_max(left_orig) + 1, whole_range.max);
704 if (rl_min(left_orig) != whole_range.min)
705 right_false = remove_range(right_orig, whole_range.min, rl_min(left_orig));
706 break;
707 case '>':
708 case SPECIAL_UNSIGNED_GT:
709 if (rl_min(right_orig) != whole_range.min)
710 left_true = remove_range(left_orig, whole_range.min, rl_min(right_orig));
711 if (rl_max(right_orig) != whole_range.max)
712 left_false = remove_range(left_orig, rl_max(right_orig) + 1, whole_range.max);
714 if (rl_max(left_orig) != whole_range.max)
715 right_true = remove_range(right_orig, rl_max(left_orig), whole_range.max);
716 if (rl_min(left_orig) != whole_range.min)
717 right_false = remove_range(right_orig, whole_range.min, rl_min(left_orig) - 1);
718 break;
719 case SPECIAL_NOTEQUAL:
720 if (rl_max(right_orig) != whole_range.max)
721 left_false = remove_range(left_false, rl_max(right_orig) + 1, whole_range.max);
722 if (rl_min(right_orig) != whole_range.min)
723 left_false = remove_range(left_false, whole_range.min, rl_min(right_orig) - 1);
724 if (rl_min(right_orig) == rl_max(right_orig))
725 left_true = remove_range(left_orig, rl_min(right_orig), rl_min(right_orig));
727 if (rl_max(left_orig) != whole_range.max)
728 right_false = remove_range(right_false, rl_max(left_orig) + 1, whole_range.max);
729 if (rl_min(left_orig) != whole_range.min)
730 right_false = remove_range(right_false, whole_range.min, rl_min(left_orig) - 1);
731 if (rl_min(left_orig) == rl_max(left_orig))
732 right_true = remove_range(right_orig, rl_min(left_orig), rl_min(left_orig));
733 break;
734 default:
735 return;
738 left_true_state = alloc_estate_range_list(left_true);
739 left_false_state = alloc_estate_range_list(left_false);
740 right_true_state = alloc_estate_range_list(right_true);
741 right_false_state = alloc_estate_range_list(right_false);
743 if (left_postop == SPECIAL_INCREMENT) {
744 left_true_state = increment_state(left_true_state);
745 left_false_state = increment_state(left_false_state);
747 if (left_postop == SPECIAL_DECREMENT) {
748 left_true_state = decrement_state(left_true_state);
749 left_false_state = decrement_state(left_false_state);
751 if (right_postop == SPECIAL_INCREMENT) {
752 right_true_state = increment_state(right_true_state);
753 right_false_state = increment_state(right_false_state);
755 if (right_postop == SPECIAL_DECREMENT) {
756 right_true_state = decrement_state(right_true_state);
757 right_false_state = decrement_state(right_false_state);
760 set_extra_expr_true_false(left, left_true_state, left_false_state);
761 set_extra_expr_true_false(right, right_true_state, right_false_state);
764 /* this is actually hooked from smatch_implied.c... it's hacky, yes */
765 void __extra_match_condition(struct expression *expr)
767 struct symbol *sym;
768 char *name;
769 struct smatch_state *pre_state;
770 struct smatch_state *true_state;
771 struct smatch_state *false_state;
773 expr = strip_expr(expr);
774 switch (expr->type) {
775 case EXPR_CALL:
776 function_comparison(SPECIAL_NOTEQUAL, expr, 0, 1);
777 return;
778 case EXPR_PREOP:
779 case EXPR_SYMBOL:
780 case EXPR_DEREF:
781 name = get_variable_from_expr(expr, &sym);
782 if (!name)
783 return;
784 pre_state = get_state(my_id, name, sym);
785 true_state = add_filter(pre_state, 0);
786 if (possibly_true(expr, SPECIAL_EQUAL, zero_expr()))
787 false_state = alloc_estate(0);
788 else
789 false_state = alloc_estate_empty();
790 set_extra_true_false(name, sym, true_state, false_state);
791 free_string(name);
792 return;
793 case EXPR_COMPARE:
794 match_comparison(expr);
795 return;
796 case EXPR_ASSIGNMENT:
797 __extra_match_condition(expr->left);
798 return;
802 /* returns 1 if it is not possible for expr to be value, otherwise returns 0 */
803 int implied_not_equal(struct expression *expr, long long val)
805 return !possibly_false(expr, SPECIAL_NOTEQUAL, value_expr(val));
808 int get_implied_range_list(struct expression *expr, struct range_list **rl)
810 long long val;
811 struct smatch_state *state;
812 long long min;
813 long long max;
815 *rl = NULL;
817 expr = strip_parens(expr);
818 if (!expr)
819 return 0;
821 state = get_state_expr(my_id, expr);
822 if (state) {
823 *rl = clone_range_list(estate_ranges(state));
824 return 1;
827 if (expr->type == EXPR_CALL) {
828 *rl = db_return_vals(expr);
829 return !!*rl;
832 if (get_implied_value(expr, &val)) {
833 add_range(rl, val, val);
834 return 1;
837 if (expr->type == EXPR_BINOP && expr->op == '%') {
838 if (!get_implied_value(expr->right, &val))
839 return 0;
840 add_range(rl, 0, val - 1);
841 return 1;
844 if (!get_implied_min(expr, &min))
845 return 0;
846 if (!get_implied_max(expr, &max))
847 return 0;
849 *rl = alloc_range_list(min, max);
850 return 1;
853 int is_whole_range(struct smatch_state *state)
855 return is_whole_range_rl(estate_ranges(state));
858 static void struct_member_callback(char *fn, int param, char *printed_name, struct smatch_state *state)
860 if (is_whole_range(state))
861 return;
862 sm_msg("info: passes param_value '%s' %d '%s' %s", fn, param, printed_name, state->name);
865 static void match_call_info(struct expression *expr)
867 struct range_list *rl = NULL;
868 struct expression *arg;
869 char *name;
870 int i = 0;
872 name = get_fnptr_name(expr->fn);
873 if (!name)
874 return;
876 FOR_EACH_PTR(expr->args, arg) {
877 if (get_implied_range_list(arg, &rl) && !is_whole_range_rl(rl)) {
878 sm_msg("info: passes param_value '%s' %d '$$' %s",
879 name, i, show_ranges(rl));
881 i++;
882 } END_FOR_EACH_PTR(arg);
884 free_string(name);
887 void set_param_value(const char *name, struct symbol *sym, char *key, char *value)
889 struct range_list *rl = NULL;
890 struct smatch_state *state;
891 char fullname[256];
893 if (strncmp(key, "$$", 2))
894 return;
896 snprintf(fullname, 256, "%s%s", name, key + 2);
897 get_value_ranges(value, &rl);
898 char *tmp = show_ranges(rl);
899 if (strcmp(tmp, value))
900 sm_msg("value = %s, ranges = %s", value, tmp);
901 state = alloc_estate_range_list(rl);
902 set_state(SMATCH_EXTRA, fullname, sym, state);
905 static void match_call_assign(struct expression *expr)
907 struct expression *right;
908 struct range_list *rl;
910 if (expr->op != '=')
911 return;
913 right = strip_parens(expr->right);
914 while (right->type == EXPR_ASSIGNMENT && right->op == '=')
915 right = strip_parens(right->left);
917 rl = db_return_vals(right);
918 if (rl)
919 set_extra_expr_mod(expr->left, alloc_estate_range_list(rl));
920 else
921 set_extra_expr_mod(expr->left, extra_undefined());
924 void register_smatch_extra(int id)
926 my_id = id;
927 add_merge_hook(my_id, &merge_func);
928 add_unmatched_state_hook(my_id, &unmatched_state);
929 add_hook(&unop_expr, OP_HOOK);
930 add_hook(&match_function_def, FUNC_DEF_HOOK);
931 add_hook(&match_function_call, FUNCTION_CALL_HOOK);
932 add_hook(&match_assign, ASSIGNMENT_HOOK);
933 add_hook(&match_call_assign, CALL_ASSIGNMENT_HOOK);
934 add_hook(&match_declarations, DECLARATION_HOOK);
935 if (option_info) {
936 add_hook(&match_call_info, FUNCTION_CALL_HOOK);
937 add_member_info_callback(my_id, struct_member_callback);
939 add_definition_db_callback(set_param_value, PARAM_VALUE);
942 void register_smatch_extra_late(int id)
944 set_default_modification_hook(SMATCH_EXTRA, reset_struct_members);