validation/sm_compare12.c: update to reflect latest code
[smatch.git] / smatch_function_hooks.c
blob13a66dc65c494c6a39c07389da12b4be5315d7a3
1 /*
2 * Copyright (C) 2009 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 * There are several types of function hooks:
20 * add_function_hook() - For any time a function is called.
21 * add_function_assign_hook() - foo = the_function().
22 * add_implied_return_hook() - Calculates the implied return value.
23 * add_macro_assign_hook() - foo = the_macro().
24 * return_implies_state() - For when a return value of 1 implies locked
25 * and 0 implies unlocked. etc. etc.
29 #include <stdlib.h>
30 #include <stdio.h>
31 #include "smatch.h"
32 #include "smatch_slist.h"
33 #include "smatch_extra.h"
34 #include "smatch_function_hashtable.h"
36 struct fcall_back {
37 int type;
38 struct data_range *range;
39 union {
40 func_hook *call_back;
41 implication_hook *ranged;
42 implied_return_hook *implied_return;
43 } u;
44 void *info;
47 ALLOCATOR(fcall_back, "call backs");
48 DECLARE_PTR_LIST(call_back_list, struct fcall_back);
50 DEFINE_FUNCTION_HASHTABLE_STATIC(callback, struct fcall_back, struct call_back_list);
51 static struct hashtable *func_hash;
53 #define REGULAR_CALL 0
54 #define RANGED_CALL 1
55 #define ASSIGN_CALL 2
56 #define IMPLIED_RETURN 3
57 #define MACRO_ASSIGN 4
58 #define MACRO_ASSIGN_EXTRA 5
60 struct return_implies_callback {
61 int type;
62 return_implies_hook *callback;
64 ALLOCATOR(return_implies_callback, "return_implies callbacks");
65 DECLARE_PTR_LIST(db_implies_list, struct return_implies_callback);
66 static struct db_implies_list *db_return_states_list;
68 typedef void (void_fn)(void);
69 DECLARE_PTR_LIST(void_fn_list, void_fn *);
70 static struct void_fn_list *return_states_before;
71 static struct void_fn_list *return_states_after;
73 static struct fcall_back *alloc_fcall_back(int type, void *call_back,
74 void *info)
76 struct fcall_back *cb;
78 cb = __alloc_fcall_back(0);
79 cb->type = type;
80 cb->u.call_back = call_back;
81 cb->info = info;
82 return cb;
85 void add_function_hook(const char *look_for, func_hook *call_back, void *info)
87 struct fcall_back *cb;
89 cb = alloc_fcall_back(REGULAR_CALL, call_back, info);
90 add_callback(func_hash, look_for, cb);
93 void add_function_assign_hook(const char *look_for, func_hook *call_back,
94 void *info)
96 struct fcall_back *cb;
98 cb = alloc_fcall_back(ASSIGN_CALL, call_back, info);
99 add_callback(func_hash, look_for, cb);
102 void add_implied_return_hook(const char *look_for,
103 implied_return_hook *call_back,
104 void *info)
106 struct fcall_back *cb;
108 cb = alloc_fcall_back(IMPLIED_RETURN, call_back, info);
109 add_callback(func_hash, look_for, cb);
112 void add_macro_assign_hook(const char *look_for, func_hook *call_back,
113 void *info)
115 struct fcall_back *cb;
117 cb = alloc_fcall_back(MACRO_ASSIGN, call_back, info);
118 add_callback(func_hash, look_for, cb);
121 void add_macro_assign_hook_extra(const char *look_for, func_hook *call_back,
122 void *info)
124 struct fcall_back *cb;
126 cb = alloc_fcall_back(MACRO_ASSIGN_EXTRA, call_back, info);
127 add_callback(func_hash, look_for, cb);
130 void return_implies_state(const char *look_for, long long start, long long end,
131 implication_hook *call_back, void *info)
133 struct fcall_back *cb;
135 cb = alloc_fcall_back(RANGED_CALL, call_back, info);
136 cb->range = alloc_range_perm(ll_to_sval(start), ll_to_sval(end));
137 add_callback(func_hash, look_for, cb);
140 void select_return_states_hook(int type, return_implies_hook *callback)
142 struct return_implies_callback *cb = __alloc_return_implies_callback(0);
144 cb->type = type;
145 cb->callback = callback;
146 add_ptr_list(&db_return_states_list, cb);
149 void select_return_states_before(void_fn *fn)
151 void_fn **p = malloc(sizeof(void_fn *));
152 *p = fn;
153 add_ptr_list(&return_states_before, p);
156 void select_return_states_after(void_fn *fn)
158 void_fn **p = malloc(sizeof(void_fn *));
159 *p = fn;
160 add_ptr_list(&return_states_after, p);
163 static void call_return_states_before_hooks(void)
165 void_fn **fn;
167 FOR_EACH_PTR(return_states_before, fn) {
168 (*fn)();
169 } END_FOR_EACH_PTR(fn);
172 static void call_return_states_after_hooks(struct expression *expr)
174 void_fn **fn;
176 FOR_EACH_PTR(return_states_after, fn) {
177 (*fn)();
178 } END_FOR_EACH_PTR(fn);
179 __pass_to_client(expr, FUNCTION_CALL_HOOK_AFTER_DB);
182 static int call_call_backs(struct call_back_list *list, int type,
183 const char *fn, struct expression *expr)
185 struct fcall_back *tmp;
186 int handled = 0;
188 FOR_EACH_PTR(list, tmp) {
189 if (tmp->type == type) {
190 (tmp->u.call_back)(fn, expr, tmp->info);
191 handled = 1;
193 } END_FOR_EACH_PTR(tmp);
195 return handled;
198 static void call_ranged_call_backs(struct call_back_list *list,
199 const char *fn, struct expression *call_expr,
200 struct expression *assign_expr)
202 struct fcall_back *tmp;
204 FOR_EACH_PTR(list, tmp) {
205 (tmp->u.ranged)(fn, call_expr, assign_expr, tmp->info);
206 } END_FOR_EACH_PTR(tmp);
209 static struct call_back_list *get_same_ranged_call_backs(struct call_back_list *list,
210 struct data_range *drange)
212 struct call_back_list *ret = NULL;
213 struct fcall_back *tmp;
215 FOR_EACH_PTR(list, tmp) {
216 if (tmp->type != RANGED_CALL)
217 continue;
218 if (ranges_equiv(tmp->range, drange))
219 add_ptr_list(&ret, tmp);
220 } END_FOR_EACH_PTR(tmp);
221 return ret;
224 static int in_list_exact_sval(struct range_list *list, struct data_range *drange)
226 struct data_range *tmp;
228 FOR_EACH_PTR(list, tmp) {
229 if (ranges_equiv(tmp, drange))
230 return 1;
231 } END_FOR_EACH_PTR(tmp);
232 return 0;
235 static int assign_ranged_funcs(const char *fn, struct expression *expr,
236 struct call_back_list *call_backs)
238 struct fcall_back *tmp;
239 struct sm_state *sm;
240 char *var_name;
241 struct symbol *sym;
242 struct smatch_state *estate;
243 struct stree *tmp_stree;
244 struct stree *final_states = NULL;
245 struct range_list *handled_ranges = NULL;
246 struct call_back_list *same_range_call_backs = NULL;
247 int handled = 0;
249 if (!call_backs)
250 return 0;
252 var_name = expr_to_var_sym(expr->left, &sym);
253 if (!var_name || !sym)
254 goto free;
256 FOR_EACH_PTR(call_backs, tmp) {
257 if (tmp->type != RANGED_CALL)
258 continue;
260 if (in_list_exact_sval(handled_ranges, tmp->range))
261 continue;
262 __push_fake_cur_stree();
263 tack_on(&handled_ranges, tmp->range);
265 same_range_call_backs = get_same_ranged_call_backs(call_backs, tmp->range);
266 call_ranged_call_backs(same_range_call_backs, fn, expr->right, expr);
267 __free_ptr_list((struct ptr_list **)&same_range_call_backs);
269 estate = alloc_estate_range(tmp->range->min, tmp->range->max);
270 set_extra_mod(var_name, sym, estate);
272 tmp_stree = __pop_fake_cur_stree();
273 merge_fake_stree(&final_states, tmp_stree);
274 free_stree(&tmp_stree);
275 handled = 1;
276 } END_FOR_EACH_PTR(tmp);
278 FOR_EACH_SM(final_states, sm) {
279 __set_sm(sm);
280 } END_FOR_EACH_SM(sm);
282 free_stree(&final_states);
283 free:
284 free_string(var_name);
285 return handled;
288 static void call_implies_callbacks(int comparison, struct expression *expr, sval_t sval, int left, struct stree **implied_true, struct stree **implied_false)
290 struct call_back_list *call_backs;
291 struct fcall_back *tmp;
292 const char *fn;
293 struct data_range *value_range;
294 struct stree *true_states = NULL;
295 struct stree *false_states = NULL;
296 struct stree *tmp_stree;
298 *implied_true = NULL;
299 *implied_false = NULL;
300 if (expr->fn->type != EXPR_SYMBOL || !expr->fn->symbol)
301 return;
302 fn = expr->fn->symbol->ident->name;
303 call_backs = search_callback(func_hash, (char *)expr->fn->symbol->ident->name);
304 if (!call_backs)
305 return;
306 value_range = alloc_range(sval, sval);
308 /* set true states */
309 __push_fake_cur_stree();
310 FOR_EACH_PTR(call_backs, tmp) {
311 if (tmp->type != RANGED_CALL)
312 continue;
313 if (!true_comparison_range_LR(comparison, tmp->range, value_range, left))
314 continue;
315 (tmp->u.ranged)(fn, expr, NULL, tmp->info);
316 } END_FOR_EACH_PTR(tmp);
317 tmp_stree = __pop_fake_cur_stree();
318 merge_fake_stree(&true_states, tmp_stree);
319 free_stree(&tmp_stree);
321 /* set false states */
322 __push_fake_cur_stree();
323 FOR_EACH_PTR(call_backs, tmp) {
324 if (tmp->type != RANGED_CALL)
325 continue;
326 if (!false_comparison_range_LR(comparison, tmp->range, value_range, left))
327 continue;
328 (tmp->u.ranged)(fn, expr, NULL, tmp->info);
329 } END_FOR_EACH_PTR(tmp);
330 tmp_stree = __pop_fake_cur_stree();
331 merge_fake_stree(&false_states, tmp_stree);
332 free_stree(&tmp_stree);
334 *implied_true = true_states;
335 *implied_false = false_states;
338 struct db_callback_info {
339 int true_side;
340 int comparison;
341 struct expression *expr;
342 struct range_list *rl;
343 int left;
344 struct stree *stree;
345 struct db_implies_list *callbacks;
346 int prev_return_id;
347 int cull;
348 int has_states;
349 struct smatch_state *ret_state;
350 struct expression *var_expr;
351 int handled;
354 static void store_return_state(struct db_callback_info *db_info, struct smatch_state *state)
356 db_info->ret_state = state;
359 static void set_return_state(struct expression *expr, struct db_callback_info *db_info)
361 struct smatch_state *state;
363 if (!db_info->ret_state)
364 return;
366 state = alloc_estate_rl(cast_rl(get_type(expr), clone_rl(estate_rl(db_info->ret_state))));
367 set_extra_expr_mod(expr, state);
368 db_info->ret_state = NULL;
371 static void handle_ret_equals_param(char *ret_string, struct range_list *rl, struct expression *call)
373 char *str;
374 long long param;
375 struct expression *arg;
376 struct range_list *orig;
378 str = strstr(ret_string, "==$");
379 if (!str)
380 return;
381 str += 3;
382 param = strtoll(str, NULL, 10);
383 arg = get_argument_from_call_expr(call->args, param);
384 if (!arg)
385 return;
386 get_absolute_rl(arg, &orig);
387 rl = rl_intersection(orig, rl);
388 if (!rl)
389 return;
390 set_extra_expr_nomod(arg, alloc_estate_rl(rl));
393 static int impossible_limit(struct expression *expr, int param, char *key, char *value)
395 struct expression *arg;
396 struct smatch_state *state;
397 struct range_list *passed;
398 struct range_list *limit;
399 struct symbol *compare_type;
401 while (expr->type == EXPR_ASSIGNMENT)
402 expr = strip_expr(expr->right);
403 if (expr->type != EXPR_CALL)
404 return 0;
406 arg = get_argument_from_call_expr(expr->args, param);
407 if (!arg)
408 return 0;
410 if (strcmp(key, "$") == 0) {
411 if (!get_implied_rl(arg, &passed))
412 return 0;
414 compare_type = get_arg_type(expr->fn, param);
415 } else {
416 char *name;
417 struct symbol *sym;
419 name = get_variable_from_key(arg, key, &sym);
420 if (!name || !sym)
421 return 0;
423 state = get_state(SMATCH_EXTRA, name, sym);
424 if (!state) {
425 free_string(name);
426 return 0;
428 passed = estate_rl(state);
429 if (!passed || is_whole_rl(passed)) {
430 free_string(name);
431 return 0;
434 compare_type = get_member_type_from_key(arg, key);
437 passed = cast_rl(compare_type, passed);
438 call_results_to_rl(expr, compare_type, value, &limit);
439 if (!limit || is_whole_rl(limit))
440 return 0;
441 if (possibly_true_rl(passed, SPECIAL_EQUAL, limit))
442 return 0;
443 if (option_debug || local_debug)
444 sm_msg("impossible: %d '%s' limit '%s' == '%s'", param, key, show_rl(passed), value);
445 return 1;
448 static int is_impossible_data(int type, struct expression *expr, int param, char *key, char *value)
450 if (type == PARAM_LIMIT && impossible_limit(expr, param, key, value))
451 return 1;
452 if (type == COMPARE_LIMIT && param_compare_limit_is_impossible(expr, param, key, value))
453 return 1;
454 return 0;
457 static int func_type_mismatch(struct expression *expr, const char *value)
459 struct symbol *type;
461 /* This makes faking returns easier */
462 if (!value || value[0] == '\0')
463 return 0;
465 while (expr->type == EXPR_ASSIGNMENT)
466 expr = strip_expr(expr->right);
469 * Short cut: We only care about function pointers that are struct
470 * members.
473 if (expr->fn->type == EXPR_SYMBOL)
474 return 0;
476 type = get_type(expr->fn);
477 if (!type)
478 return 0;
479 if (type->type == SYM_PTR)
480 type = get_real_base_type(type);
482 if (strcmp(type_to_str(type), value) == 0)
483 return 0;
485 return 1;
488 static int db_compare_callback(void *_info, int argc, char **argv, char **azColName)
490 struct db_callback_info *db_info = _info;
491 struct range_list *var_rl = db_info->rl;
492 struct range_list *ret_range;
493 int type, param;
494 char *key, *value;
495 struct return_implies_callback *tmp;
496 struct stree *stree;
497 int return_id;
498 int comparison;
500 if (argc != 6)
501 return 0;
503 return_id = atoi(argv[0]);
504 type = atoi(argv[2]);
505 param = atoi(argv[3]);
506 key = argv[4];
507 value = argv[5];
509 db_info->has_states = 1;
510 if (db_info->prev_return_id != -1 && type == INTERNAL) {
511 set_return_state(db_info->var_expr, db_info);
512 stree = __pop_fake_cur_stree();
514 if (!db_info->cull)
515 merge_fake_stree(&db_info->stree, stree);
516 free_stree(&stree);
517 __push_fake_cur_stree();
518 db_info->cull = 0;
520 db_info->prev_return_id = return_id;
522 if (type == INTERNAL && func_type_mismatch(db_info->expr, value))
523 db_info->cull = 1;
524 if (db_info->cull)
525 return 0;
526 if (type == CULL_PATH) {
527 db_info->cull = 1;
528 return 0;
531 if (is_impossible_data(type, db_info->expr, param, key, value)) {
532 db_info->cull = 1;
533 return 0;
536 call_results_to_rl(db_info->expr, get_type(strip_expr(db_info->expr)), argv[1], &ret_range);
537 ret_range = cast_rl(get_type(db_info->expr), ret_range);
538 if (!ret_range)
539 ret_range = alloc_whole_rl(get_type(db_info->expr));
541 comparison = db_info->comparison;
542 if (db_info->left)
543 comparison = flip_comparison(comparison);
545 if (db_info->true_side) {
546 if (!possibly_true_rl(var_rl, comparison, ret_range))
547 return 0;
548 if (type == PARAM_LIMIT)
549 param_limit_implications(db_info->expr, param, key, value);
550 filter_by_comparison(&var_rl, comparison, ret_range);
551 filter_by_comparison(&ret_range, flip_comparison(comparison), var_rl);
552 } else {
553 if (!possibly_false_rl(var_rl, comparison, ret_range))
554 return 0;
555 if (type == PARAM_LIMIT)
556 param_limit_implications(db_info->expr, param, key, value);
557 filter_by_comparison(&var_rl, negate_comparison(comparison), ret_range);
558 filter_by_comparison(&ret_range, flip_comparison(negate_comparison(comparison)), var_rl);
561 handle_ret_equals_param(argv[1], ret_range, db_info->expr);
563 if (type == INTERNAL) {
564 set_state(-1, "unnull_path", NULL, &true_state);
565 __add_return_comparison(strip_expr(db_info->expr), argv[1]);
566 __add_return_to_param_mapping(db_info->expr, argv[1]);
569 FOR_EACH_PTR(db_info->callbacks, tmp) {
570 if (tmp->type == type)
571 tmp->callback(db_info->expr, param, key, value);
572 } END_FOR_EACH_PTR(tmp);
574 store_return_state(db_info, alloc_estate_rl(clone_rl(var_rl)));
575 return 0;
578 static void compare_db_return_states_callbacks(struct expression *left, int comparison, struct expression *right, struct stree *implied_true, struct stree *implied_false)
580 struct stree *orig_states;
581 struct stree *stree;
582 struct stree *true_states;
583 struct stree *false_states;
584 struct sm_state *sm;
585 struct db_callback_info db_info = {};
586 struct expression *var_expr;
587 struct expression *call_expr;
588 struct range_list *rl;
589 int call_on_left;
591 orig_states = clone_stree(__get_cur_stree());
593 /* legacy cruft. need to fix call_implies_callbacks(). */
594 call_on_left = 1;
595 call_expr = left;
596 var_expr = right;
597 if (left->type != EXPR_CALL) {
598 call_on_left = 0;
599 call_expr = right;
600 var_expr = left;
603 get_absolute_rl(var_expr, &rl);
605 db_info.comparison = comparison;
606 db_info.expr = call_expr;
607 db_info.rl = rl;
608 db_info.left = call_on_left;
609 db_info.callbacks = db_return_states_list;
610 db_info.var_expr = var_expr;
612 call_return_states_before_hooks();
614 db_info.true_side = 1;
615 db_info.stree = NULL;
616 db_info.prev_return_id = -1;
617 __push_fake_cur_stree();
618 sql_select_return_states("return_id, return, type, parameter, key, value",
619 call_expr, db_compare_callback, &db_info);
620 set_return_state(db_info.var_expr, &db_info);
621 stree = __pop_fake_cur_stree();
622 if (!db_info.cull) {
623 set_return_state(db_info.var_expr, &db_info);
624 merge_fake_stree(&db_info.stree, stree);
626 free_stree(&stree);
627 true_states = db_info.stree;
628 if (!true_states && db_info.has_states) {
629 __push_fake_cur_stree();
630 set_path_impossible();
631 true_states = __pop_fake_cur_stree();
634 nullify_path();
635 __unnullify_path();
636 FOR_EACH_SM(orig_states, sm) {
637 __set_sm_cur_stree(sm);
638 } END_FOR_EACH_SM(sm);
640 db_info.true_side = 0;
641 db_info.stree = NULL;
642 db_info.prev_return_id = -1;
643 db_info.cull = 0;
644 __push_fake_cur_stree();
645 sql_select_return_states("return_id, return, type, parameter, key, value", call_expr,
646 db_compare_callback, &db_info);
647 stree = __pop_fake_cur_stree();
648 if (!db_info.cull) {
649 set_return_state(db_info.var_expr, &db_info);
650 merge_fake_stree(&db_info.stree, stree);
652 free_stree(&stree);
653 false_states = db_info.stree;
654 if (!false_states && db_info.has_states) {
655 __push_fake_cur_stree();
656 set_path_impossible();
657 false_states = __pop_fake_cur_stree();
660 nullify_path();
661 __unnullify_path();
662 FOR_EACH_SM(orig_states, sm) {
663 __set_sm_cur_stree(sm);
664 } END_FOR_EACH_SM(sm);
666 free_stree(&orig_states);
668 FOR_EACH_SM(true_states, sm) {
669 __set_true_false_sm(sm, NULL);
670 } END_FOR_EACH_SM(sm);
671 FOR_EACH_SM(false_states, sm) {
672 __set_true_false_sm(NULL, sm);
673 } END_FOR_EACH_SM(sm);
675 free_stree(&true_states);
676 free_stree(&false_states);
678 call_return_states_after_hooks(call_expr);
680 FOR_EACH_SM(implied_true, sm) {
681 __set_true_false_sm(sm, NULL);
682 } END_FOR_EACH_SM(sm);
683 FOR_EACH_SM(implied_false, sm) {
684 __set_true_false_sm(NULL, sm);
685 } END_FOR_EACH_SM(sm);
688 void function_comparison(struct expression *left, int comparison, struct expression *right)
690 struct expression *var_expr;
691 struct expression *call_expr;
692 struct stree *implied_true = NULL;
693 struct stree *implied_false = NULL;
694 struct range_list *rl;
695 sval_t sval;
696 int call_on_left;
698 if (unreachable())
699 return;
701 /* legacy cruft. need to fix call_implies_callbacks(). */
702 call_on_left = 1;
703 call_expr = left;
704 var_expr = right;
705 if (left->type != EXPR_CALL) {
706 call_on_left = 0;
707 call_expr = right;
708 var_expr = left;
711 get_absolute_rl(var_expr, &rl);
713 if (rl_to_sval(rl, &sval))
714 call_implies_callbacks(comparison, call_expr, sval, call_on_left, &implied_true, &implied_false);
716 compare_db_return_states_callbacks(left, comparison, right, implied_true, implied_false);
717 free_stree(&implied_true);
718 free_stree(&implied_false);
721 static void call_ranged_return_hooks(struct db_callback_info *db_info)
723 struct call_back_list *call_backs;
724 struct expression *expr;
725 struct fcall_back *tmp;
726 char *fn;
728 expr = strip_expr(db_info->expr);
729 while (expr->type == EXPR_ASSIGNMENT)
730 expr = strip_expr(expr->right);
731 if (expr->type != EXPR_CALL ||
732 expr->fn->type != EXPR_SYMBOL)
733 return;
735 fn = expr->fn->symbol_name->name;
737 call_backs = search_callback(func_hash, fn);
738 FOR_EACH_PTR(call_backs, tmp) {
739 struct range_list *range_rl = NULL;
741 if (tmp->type != RANGED_CALL)
742 continue;
743 add_range(&range_rl, tmp->range->min, tmp->range->max);
744 range_rl = cast_rl(estate_type(db_info->ret_state), range_rl);
745 if (possibly_true_rl(range_rl, SPECIAL_EQUAL, estate_rl(db_info->ret_state))) {
746 if (!possibly_true_rl(rl_invert(range_rl), SPECIAL_EQUAL, estate_rl(db_info->ret_state)))
747 (tmp->u.ranged)(fn, expr, db_info->expr, tmp->info);
748 else
749 db_info->handled = -1;
751 } END_FOR_EACH_PTR(tmp);
754 static int db_assign_return_states_callback(void *_info, int argc, char **argv, char **azColName)
756 struct db_callback_info *db_info = _info;
757 struct range_list *ret_range;
758 int type, param;
759 char *key, *value;
760 struct return_implies_callback *tmp;
761 struct stree *stree;
762 int return_id;
764 if (argc != 6)
765 return 0;
767 return_id = atoi(argv[0]);
768 type = atoi(argv[2]);
769 param = atoi(argv[3]);
770 key = argv[4];
771 value = argv[5];
773 if (db_info->prev_return_id != -1 && type == INTERNAL) {
774 call_ranged_return_hooks(db_info);
775 set_return_state(db_info->expr->left, db_info);
776 stree = __pop_fake_cur_stree();
777 if (!db_info->cull)
778 merge_fake_stree(&db_info->stree, stree);
779 free_stree(&stree);
780 __push_fake_cur_stree();
781 db_info->cull = 0;
783 db_info->prev_return_id = return_id;
785 if (type == INTERNAL && func_type_mismatch(db_info->expr, value))
786 db_info->cull = 1;
787 if (db_info->cull)
788 return 0;
789 if (type == CULL_PATH) {
790 db_info->cull = 1;
791 return 0;
793 if (is_impossible_data(type, db_info->expr, param, key, value)) {
794 db_info->cull = 1;
795 return 0;
798 if (type == PARAM_LIMIT)
799 param_limit_implications(db_info->expr, param, key, value);
801 db_info->handled = 1;
802 call_results_to_rl(db_info->expr->right, get_type(strip_expr(db_info->expr->right)), argv[1], &ret_range);
803 if (!ret_range)
804 ret_range = alloc_whole_rl(get_type(strip_expr(db_info->expr->right)));
805 ret_range = cast_rl(get_type(db_info->expr->right), ret_range);
807 if (type == INTERNAL) {
808 set_state(-1, "unnull_path", NULL, &true_state);
809 __add_return_comparison(strip_expr(db_info->expr->right), argv[1]);
810 __add_comparison_info(db_info->expr->left, strip_expr(db_info->expr->right), argv[1]);
811 __add_return_to_param_mapping(db_info->expr, argv[1]);
814 FOR_EACH_PTR(db_return_states_list, tmp) {
815 if (tmp->type == type)
816 tmp->callback(db_info->expr, param, key, value);
817 } END_FOR_EACH_PTR(tmp);
818 store_return_state(db_info, alloc_estate_rl(ret_range));
820 return 0;
823 static int db_return_states_assign(struct expression *expr)
825 struct expression *right;
826 struct sm_state *sm;
827 struct stree *stree;
828 struct db_callback_info db_info = {};
830 right = strip_expr(expr->right);
832 db_info.prev_return_id = -1;
833 db_info.expr = expr;
834 db_info.stree = NULL;
835 db_info.handled = 0;
837 call_return_states_before_hooks();
839 __push_fake_cur_stree();
840 sql_select_return_states("return_id, return, type, parameter, key, value",
841 right, db_assign_return_states_callback, &db_info);
842 if (option_debug) {
843 sm_msg("%s return_id %d return_ranges %s",
844 db_info.cull ? "culled" : "merging",
845 db_info.prev_return_id,
846 db_info.ret_state ? db_info.ret_state->name : "'<empty>'");
848 if (db_info.handled)
849 call_ranged_return_hooks(&db_info);
850 set_return_state(db_info.expr->left, &db_info);
851 stree = __pop_fake_cur_stree();
852 if (!db_info.cull)
853 merge_fake_stree(&db_info.stree, stree);
854 free_stree(&stree);
856 if (!db_info.stree && db_info.cull) /* this means we culled everything */
857 set_extra_expr_mod(expr->left, alloc_estate_whole(get_type(expr->left)));
858 FOR_EACH_SM(db_info.stree, sm) {
859 __set_sm(sm);
860 } END_FOR_EACH_SM(sm);
862 free_stree(&db_info.stree);
863 call_return_states_after_hooks(right);
865 return db_info.handled;
868 static int handle_implied_return(struct expression *expr)
870 struct range_list *rl;
872 if (!get_implied_return(expr->right, &rl))
873 return 0;
874 rl = cast_rl(get_type(expr->left), rl);
875 set_extra_expr_mod(expr->left, alloc_estate_rl(rl));
876 return 1;
879 static void match_assign_call(struct expression *expr)
881 struct call_back_list *call_backs;
882 const char *fn;
883 struct expression *right;
884 int handled = 0;
885 struct range_list *rl;
887 if (expr->op != '=')
888 return;
890 right = strip_expr(expr->right);
891 if (right->fn->type != EXPR_SYMBOL || !right->fn->symbol) {
892 handled |= db_return_states_assign(expr);
893 if (!handled)
894 goto assigned_unknown;
895 return;
897 if (is_fake_call(right)) {
898 set_extra_expr_mod(expr->left, alloc_estate_whole(get_type(expr->left)));
899 return;
902 fn = right->fn->symbol->ident->name;
903 call_backs = search_callback(func_hash, (char *)fn);
906 * The ordering here is sort of important.
907 * One example, of how this matters is that when we do:
909 * len = strlen(str);
911 * That is handled by smatch_common_functions.c and smatch_strlen.c.
912 * They use implied_return and function_assign_hook respectively.
913 * We want to get the implied return first before we do the function
914 * assignment hook otherwise we end up writing the wrong thing for len
915 * in smatch_extra.c because we assume that it already holds the
916 * strlen() when we haven't set it yet.
919 if (db_return_states_assign(expr) == 1)
920 handled = 1;
921 else
922 handled = assign_ranged_funcs(fn, expr, call_backs);
923 handled |= handle_implied_return(expr);
926 call_call_backs(call_backs, ASSIGN_CALL, fn, expr);
928 if (handled)
929 return;
931 assigned_unknown:
932 get_absolute_rl(expr->right, &rl);
933 rl = cast_rl(get_type(expr->left), rl);
934 set_extra_expr_mod(expr->left, alloc_estate_rl(rl));
937 static int db_return_states_callback(void *_info, int argc, char **argv, char **azColName)
939 struct db_callback_info *db_info = _info;
940 struct range_list *ret_range;
941 int type, param;
942 char *key, *value;
943 struct return_implies_callback *tmp;
944 struct stree *stree;
945 int return_id;
946 char buf[64];
948 if (argc != 6)
949 return 0;
951 return_id = atoi(argv[0]);
952 type = atoi(argv[2]);
953 param = atoi(argv[3]);
954 key = argv[4];
955 value = argv[5];
957 if (db_info->prev_return_id != -1 && type == INTERNAL) {
958 stree = __pop_fake_cur_stree();
959 if (!db_info->cull)
960 merge_fake_stree(&db_info->stree, stree);
961 free_stree(&stree);
962 __push_fake_cur_stree();
963 __unnullify_path();
964 db_info->cull = 0;
966 db_info->prev_return_id = return_id;
968 if (type == INTERNAL && func_type_mismatch(db_info->expr, value))
969 db_info->cull = 1;
970 if (db_info->cull)
971 return 0;
972 if (type == CULL_PATH) {
973 db_info->cull = 1;
974 return 0;
976 if (is_impossible_data(type, db_info->expr, param, key, value)) {
977 db_info->cull = 1;
978 return 0;
981 if (type == PARAM_LIMIT)
982 param_limit_implications(db_info->expr, param, key, value);
984 call_results_to_rl(db_info->expr, get_type(strip_expr(db_info->expr)), argv[1], &ret_range);
985 ret_range = cast_rl(get_type(db_info->expr), ret_range);
987 if (type == INTERNAL) {
988 set_state(-1, "unnull_path", NULL, &true_state);
989 __add_return_comparison(strip_expr(db_info->expr), argv[1]);
990 __add_return_to_param_mapping(db_info->expr, argv[1]);
994 FOR_EACH_PTR(db_return_states_list, tmp) {
995 if (tmp->type == type)
996 tmp->callback(db_info->expr, param, key, value);
997 } END_FOR_EACH_PTR(tmp);
1000 * We want to store the return values so that we can split the strees
1001 * in smatch_db.c. This uses set_state() directly because it's not a
1002 * real smatch_extra state.
1004 snprintf(buf, sizeof(buf), "return %p", db_info->expr);
1005 set_state(SMATCH_EXTRA, buf, NULL, alloc_estate_rl(ret_range));
1007 return 0;
1010 static void db_return_states(struct expression *expr)
1012 struct sm_state *sm;
1013 struct stree *stree;
1014 struct db_callback_info db_info = {};
1016 if (!__get_cur_stree()) /* no return functions */
1017 return;
1019 db_info.prev_return_id = -1;
1020 db_info.expr = expr;
1021 db_info.stree = NULL;
1023 call_return_states_before_hooks();
1025 __push_fake_cur_stree();
1026 __unnullify_path();
1027 sql_select_return_states("return_id, return, type, parameter, key, value",
1028 expr, db_return_states_callback, &db_info);
1029 stree = __pop_fake_cur_stree();
1030 if (!db_info.cull)
1031 merge_fake_stree(&db_info.stree, stree);
1032 free_stree(&stree);
1034 FOR_EACH_SM(db_info.stree, sm) {
1035 __set_sm(sm);
1036 } END_FOR_EACH_SM(sm);
1038 free_stree(&db_info.stree);
1039 call_return_states_after_hooks(expr);
1042 static int is_condition_call(struct expression *expr)
1044 struct expression *tmp;
1046 FOR_EACH_PTR_REVERSE(big_condition_stack, tmp) {
1047 if (expr == tmp || expr_get_parent_expr(expr) == tmp)
1048 return 1;
1049 if (tmp->pos.line < expr->pos.line)
1050 return 0;
1051 } END_FOR_EACH_PTR_REVERSE(tmp);
1053 return 0;
1056 static void db_return_states_call(struct expression *expr)
1058 if (unreachable())
1059 return;
1061 if (is_assigned_call(expr))
1062 return;
1063 if (is_condition_call(expr))
1064 return;
1065 db_return_states(expr);
1068 static void match_function_call(struct expression *expr)
1070 struct call_back_list *call_backs;
1072 if (expr->fn->type == EXPR_SYMBOL && expr->fn->symbol) {
1073 call_backs = search_callback(func_hash, (char *)expr->fn->symbol->ident->name);
1074 if (call_backs)
1075 call_call_backs(call_backs, REGULAR_CALL,
1076 expr->fn->symbol->ident->name, expr);
1078 db_return_states_call(expr);
1081 static void match_macro_assign(struct expression *expr)
1083 struct call_back_list *call_backs;
1084 const char *macro;
1085 struct expression *right;
1087 right = strip_expr(expr->right);
1088 macro = get_macro_name(right->pos);
1089 call_backs = search_callback(func_hash, (char *)macro);
1090 if (!call_backs)
1091 return;
1092 call_call_backs(call_backs, MACRO_ASSIGN, macro, expr);
1093 call_call_backs(call_backs, MACRO_ASSIGN_EXTRA, macro, expr);
1096 int get_implied_return(struct expression *expr, struct range_list **rl)
1098 struct call_back_list *call_backs;
1099 struct fcall_back *tmp;
1100 int handled = 0;
1101 char *fn;
1103 *rl = NULL;
1105 expr = strip_expr(expr);
1106 fn = expr_to_var(expr->fn);
1107 if (!fn)
1108 goto out;
1110 call_backs = search_callback(func_hash, fn);
1112 FOR_EACH_PTR(call_backs, tmp) {
1113 if (tmp->type == IMPLIED_RETURN) {
1114 (tmp->u.implied_return)(expr, tmp->info, rl);
1115 handled = 1;
1117 } END_FOR_EACH_PTR(tmp);
1119 out:
1120 free_string(fn);
1121 return handled;
1124 void create_function_hook_hash(void)
1126 func_hash = create_function_hashtable(5000);
1129 void register_function_hooks(int id)
1131 add_hook(&match_function_call, CALL_HOOK_AFTER_INLINE);
1132 add_hook(&match_assign_call, CALL_ASSIGNMENT_HOOK);
1133 add_hook(&match_macro_assign, MACRO_ASSIGNMENT_HOOK);