1 /*
2 * Copyright (C) 2006 Dan Carpenter.
3 *
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.
8 *
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.
13 *
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
16 */
17
18 /*
19 * Miscellaneous helper functions.
20 */
21
22 #include <stdlib.h>
23 #include <stdio.h>
24 #include "allocate.h"
25 #include "smatch.h"
26 #include "smatch_extra.h"
27 #include "smatch_slist.h"
28
29 #define VAR_LEN 512
30
31 char *alloc_string(const char *str)
32 {
33 char *tmp;
34
35 if (!str)
36 return NULL;
37 tmp = malloc(strlen(str) + 1);
38 strcpy(tmp, str);
39 return tmp;
40 }
41
42 void free_string(char *str)
43 {
44 free(str);
45 }
46
47 void remove_parens(char *str)
48 {
49 char *src, *dst;
50
51 dst = src = str;
52 while (*src != '\0') {
53 if (*src == '(' || *src == ')') {
54 src++;
55 continue;
56 }
57 *dst++ = *src++;
58 }
59 *dst = *src;
60 }
61
62 struct smatch_state *alloc_state_num(int num)
63 {
64 struct smatch_state *state;
65 static char buff[256];
66
67 state = __alloc_smatch_state(0);
68 snprintf(buff, 255, "%d", num);
69 buff[255] = '\0';
70 state->name = alloc_string(buff);
71 state->data = INT_PTR(num);
72 return state;
73 }
74
75 struct smatch_state *alloc_state_str(const char *name)
76 {
77 struct smatch_state *state;
78
79 state = __alloc_smatch_state(0);
80 state->name = alloc_string(name);
81 return state;
82 }
83
84 struct smatch_state *alloc_state_expr(struct expression *expr)
85 {
86 struct smatch_state *state;
87 char *name;
88
89 state = __alloc_smatch_state(0);
90 expr = strip_expr(expr);
91 name = expr_to_str(expr);
92 state->name = alloc_sname(name);
93 free_string(name);
94 state->data = expr;
95 return state;
96 }
97
98 void append(char *dest, const char *data, int buff_len)
99 {
100 strncat(dest, data, buff_len - strlen(dest) - 1);
101 }
102
103 /*
104 * If you have "foo(a, b, 1);" then use
105 * get_argument_from_call_expr(expr, 0) to return the expression for
106 * a. Yes, it does start counting from 0.
107 */
108 struct expression *get_argument_from_call_expr(struct expression_list *args,
109 int num)
110 {
111 struct expression *expr;
112 int i = 0;
113
114 if (!args)
115 return NULL;
116
117 FOR_EACH_PTR(args, expr) {
118 if (i == num)
119 return expr;
120 i++;
121 } END_FOR_EACH_PTR(expr);
122 return NULL;
123 }
124
125 static struct expression *get_array_expr(struct expression *expr)
126 {
127 struct expression *parent;
128 struct symbol *type;
129
130 if (expr->type != EXPR_BINOP || expr->op != '+')
131 return NULL;
132
133 type = get_type(expr->left);
134 if (!type)
135 return NULL;
136 if (type->type == SYM_ARRAY)
137 return expr->left;
138 if (type->type != SYM_PTR)
139 return NULL;
140
141 parent = expr_get_parent_expr(expr);
142 if (!parent) /* Sometimes we haven't set up the ->parent yet. FIXME!! */
143 return expr->left;
144 if (parent->type == EXPR_PREOP && parent->op == '*')
145 return expr->left;
146
147 return NULL;
148 }
149
150 static void __get_variable_from_expr(struct symbol **sym_ptr, char *buf,
151 struct expression *expr, int len,
152 int *complicated, int no_parens)
153 {
154
155
156 if (!expr) {
157 /* can't happen on valid code */
158 *complicated = 1;
159 return;
160 }
161
162 switch (expr->type) {
163 case EXPR_DEREF: {
164 struct expression *deref;
165 int op;
166
167 deref = expr->deref;
168 op = deref->op;
169 if (op == '*') {
170 struct expression *unop = strip_expr(deref->unop);
171
172 if (unop->type == EXPR_PREOP && unop->op == '&') {
173 deref = unop->unop;
174 op = '.';
175 } else {
176 deref = deref->unop;
177 if (!is_pointer(deref))
178 op = '.';
179 }
180 }
181
182 __get_variable_from_expr(sym_ptr, buf, deref, len, complicated, no_parens);
183
184 if (op == '*')
185 append(buf, "->", len);
186 else
187 append(buf, ".", len);
188
189 if (expr->member)
190 append(buf, expr->member->name, len);
191 else
192 append(buf, "unknown_member", len);
193
194 return;
195 }
196 case EXPR_SYMBOL:
197 if (expr->symbol_name)
198 append(buf, expr->symbol_name->name, len);
199 if (sym_ptr) {
200 if (*sym_ptr)
201 *complicated = 1;
202 *sym_ptr = expr->symbol;
203 }
204 return;
205 case EXPR_PREOP: {
206 const char *tmp;
207
208 if (get_expression_statement(expr)) {
209 *complicated = 2;
210 return;
211 }
212
213 if (expr->op == '(') {
214 if (!no_parens && expr->unop->type != EXPR_SYMBOL)
215 append(buf, "(", len);
216 } else if (expr->op != '*' || !get_array_expr(expr->unop)) {
217 tmp = show_special(expr->op);
218 append(buf, tmp, len);
219 }
220 __get_variable_from_expr(sym_ptr, buf, expr->unop,
221 len, complicated, no_parens);
222
223 if (expr->op == '(' && !no_parens && expr->unop->type != EXPR_SYMBOL)
224 append(buf, ")", len);
225
226 if (expr->op == SPECIAL_DECREMENT ||
227 expr->op == SPECIAL_INCREMENT)
228 *complicated = 1;
229
230 return;
231 }
232 case EXPR_POSTOP: {
233 const char *tmp;
234
235 __get_variable_from_expr(sym_ptr, buf, expr->unop,
236 len, complicated, no_parens);
237 tmp = show_special(expr->op);
238 append(buf, tmp, len);
239
240 if (expr->op == SPECIAL_DECREMENT || expr->op == SPECIAL_INCREMENT)
241 *complicated = 1;
242 return;
243 }
244 case EXPR_ASSIGNMENT:
245 case EXPR_COMPARE:
246 case EXPR_LOGICAL:
247 case EXPR_BINOP: {
248 char tmp[10];
249 struct expression *array_expr;
250
251 *complicated = 1;
252 array_expr = get_array_expr(expr);
253 if (array_expr) {
254 __get_variable_from_expr(sym_ptr, buf, array_expr, len, complicated, no_parens);
255 append(buf, "[", len);
256 } else {
257 __get_variable_from_expr(sym_ptr, buf, expr->left, len, complicated, no_parens);
258 snprintf(tmp, sizeof(tmp), " %s ", show_special(expr->op));
259 append(buf, tmp, len);
260 }
261 __get_variable_from_expr(NULL, buf, expr->right, len, complicated, no_parens);
262 if (array_expr)
263 append(buf, "]", len);
264 return;
265 }
266 case EXPR_VALUE: {
267 char tmp[25];
268
269 *complicated = 1;
270 snprintf(tmp, 25, "%lld", expr->value);
271 append(buf, tmp, len);
272 return;
273 }
274 case EXPR_STRING:
275 append(buf, "\"", len);
276 if (expr->string)
277 append(buf, expr->string->data, len);
278 append(buf, "\"", len);
279 return;
280 case EXPR_CALL: {
281 struct expression *tmp;
282 int i;
283
284 *complicated = 1;
285 __get_variable_from_expr(NULL, buf, expr->fn, len, complicated, no_parens);
286 append(buf, "(", len);
287 i = 0;
288 FOR_EACH_PTR(expr->args, tmp) {
289 if (i++)
290 append(buf, ", ", len);
291 __get_variable_from_expr(NULL, buf, tmp, len, complicated, no_parens);
292 } END_FOR_EACH_PTR(tmp);
293 append(buf, ")", len);
294 return;
295 }
296 case EXPR_CAST:
297 case EXPR_FORCE_CAST:
298 __get_variable_from_expr(sym_ptr, buf,
299 expr->cast_expression, len,
300 complicated, no_parens);
301 return;
302 case EXPR_SIZEOF: {
303 sval_t sval;
304 int size;
305 char tmp[25];
306
307 if (expr->cast_type && get_base_type(expr->cast_type)) {
308 size = type_bytes(get_base_type(expr->cast_type));
309 snprintf(tmp, 25, "%d", size);
310 append(buf, tmp, len);
311 } else if (get_value(expr, &sval)) {
312 snprintf(tmp, 25, "%s", sval_to_str(sval));
313 append(buf, tmp, len);
314 }
315 return;
316 }
317 case EXPR_IDENTIFIER:
318 *complicated = 1;
319 if (expr->expr_ident)
320 append(buf, expr->expr_ident->name, len);
321 return;
322 default:
323 *complicated = 1;
324 //printf("unknown type = %d\n", expr->type);
325 return;
326 }
327 }
328
329 struct expr_str_cache_results {
330 struct expression *expr;
331 int no_parens;
332 char str[VAR_LEN];
333 struct symbol *sym;
334 int complicated;
335 };
336
337 static void get_variable_from_expr(struct symbol **sym_ptr, char *buf,
338 struct expression *expr, int len,
339 int *complicated, int no_parens)
340 {
341 static struct expr_str_cache_results cached[8];
342 struct symbol *tmp_sym = NULL;
343 static int idx;
344 int i;
345
346 for (i = 0; i < ARRAY_SIZE(cached); i++) {
347 if (expr == cached[i].expr &&
348 no_parens == cached[i].no_parens) {
349 strncpy(buf, cached[i].str, len);
350 if (sym_ptr)
351 *sym_ptr = cached[i].sym;
352 *complicated = cached[i].complicated;
353 return;
354 }
355 }
356
357 __get_variable_from_expr(&tmp_sym, buf, expr, len, complicated, no_parens);
358 if (sym_ptr)
359 *sym_ptr = tmp_sym;
360
361 cached[idx].expr = expr;
362 cached[idx].no_parens = no_parens;
363 strncpy(cached[idx].str, buf, VAR_LEN);
364 cached[idx].sym = tmp_sym;
365 cached[idx].complicated = *complicated;
366
367 idx = (idx + 1) % ARRAY_SIZE(cached);
368 }
369
370 /*
371 * This is returns a stylized "c looking" representation of the
372 * variable name.
373 *
374 * It uses the same buffer every time so you have to save the result
375 * yourself if you want to keep it.
376 *
377 */
378
379 char *expr_to_str_sym(struct expression *expr, struct symbol **sym_ptr)
380 {
381 static char var_name[VAR_LEN];
382 int complicated = 0;
383
384 if (sym_ptr)
385 *sym_ptr = NULL;
386 var_name[0] = '\0';
387
388 if (!expr)
389 return NULL;
390 get_variable_from_expr(sym_ptr, var_name, expr, sizeof(var_name),
391 &complicated, 0);
392 if (complicated < 2)
393 return alloc_string(var_name);
394 else
395 return NULL;
396 }
397
398 char *expr_to_str(struct expression *expr)
399 {
400 return expr_to_str_sym(expr, NULL);
401 }
402
403 /*
404 * get_variable_from_expr_simple() only returns simple variables.
405 * If it's a complicated variable like a->foo[x] instead of just 'a->foo'
406 * then it returns NULL.
407 */
408 char *expr_to_var_sym(struct expression *expr,
409 struct symbol **sym_ptr)
410 {
411 static char var_name[VAR_LEN];
412 int complicated = 0;
413
414 if (sym_ptr)
415 *sym_ptr = NULL;
416 var_name[0] = '\0';
417
418 if (!expr)
419 return NULL;
420 expr = strip_expr(expr);
421 get_variable_from_expr(sym_ptr, var_name, expr, sizeof(var_name),
422 &complicated, 1);
423
424 if (complicated) {
425 if (sym_ptr)
426 *sym_ptr = NULL;
427 return NULL;
428 }
429 return alloc_string(var_name);
430 }
431
432 char *expr_to_var(struct expression *expr)
433 {
434 return expr_to_var_sym(expr, NULL);
435 }
436
437 struct symbol *expr_to_sym(struct expression *expr)
438 {
439 struct symbol *sym;
440 char *name;
441
442 name = expr_to_var_sym(expr, &sym);
443 free_string(name);
444 return sym;
445 }
446
447 int get_complication_score(struct expression *expr)
448 {
449 expr = strip_expr(expr);
450
451 /*
452 * Don't forget to keep get_complication_score() and store_all_links()
453 * in sync.
454 *
455 */
456
457 if (!expr)
458 return 990;
459
460 switch (expr->type) {
461 case EXPR_CALL:
462 return 991;
463 case EXPR_COMPARE:
464 case EXPR_BINOP:
465 return get_complication_score(expr->left) +
466 get_complication_score(expr->right);
467 case EXPR_SYMBOL:
468 return 1;
469 case EXPR_PREOP:
470 if (expr->op == '*' || expr->op == '(')
471 return get_complication_score(expr->unop);
472 return 993;
473 case EXPR_DEREF:
474 return get_complication_score(expr->deref);
475 case EXPR_VALUE:
476 case EXPR_SIZEOF:
477 return 0;
478 default:
479 return 994;
480 }
481 }
482
483 struct expression *reorder_expr_alphabetically(struct expression *expr)
484 {
485 struct expression *ret;
486 char *left, *right;
487
488 if (expr->type != EXPR_BINOP)
489 return expr;
490 if (expr->op != '+' && expr->op != '*')
491 return expr;
492
493 left = expr_to_var(expr->left);
494 right = expr_to_var(expr->right);
495 ret = expr;
496 if (!left || !right)
497 goto free;
498 if (strcmp(left, right) <= 0)
499 goto free;
500
501 ret = binop_expression(expr->right, expr->op, expr->left);
502 free:
503 free_string(left);
504 free_string(right);
505
506 return ret;
507 }
508
509 char *expr_to_chunk_helper(struct expression *expr, struct symbol **sym, struct var_sym_list **vsl)
510 {
511 struct var_sym_list *tmp_vsl;
512 char *name;
513 struct symbol *tmp;
514 int score;
515
516 if (vsl)
517 *vsl = NULL;
518 if (sym)
519 *sym = NULL;
520
521 expr = strip_parens(expr);
522 if (!expr)
523 return NULL;
524
525 name = expr_to_var_sym(expr, &tmp);
526 if (name && tmp) {
527 if (sym)
528 *sym = tmp;
529 if (vsl)
530 *vsl = expr_to_vsl(expr);
531 return name;
532 }
533 free_string(name);
534
535 score = get_complication_score(expr);
536 if (score <= 0 || score > 2)
537 return NULL;
538
539 tmp_vsl = expr_to_vsl(expr);
540 if (vsl) {
541 *vsl = tmp_vsl;
542 if (!*vsl)
543 return NULL;
544 }
545 if (sym) {
546 if (ptr_list_size((struct ptr_list *)tmp_vsl) == 1) {
547 struct var_sym *vs;
548
549 vs = first_ptr_list((struct ptr_list *)tmp_vsl);
550 *sym = vs->sym;
551 }
552 }
553
554 expr = reorder_expr_alphabetically(expr);
555
556 return expr_to_str(expr);
557 }
558
559 char *expr_to_known_chunk_sym(struct expression *expr, struct symbol **sym)
560 {
561 return expr_to_chunk_helper(expr, sym, NULL);
562 }
563
564 char *expr_to_chunk_sym_vsl(struct expression *expr, struct symbol **sym, struct var_sym_list **vsl)
565 {
566 return expr_to_chunk_helper(expr, sym, vsl);
567 }
568
569 int sym_name_is(const char *name, struct expression *expr)
570 {
571 if (!expr)
572 return 0;
573 if (expr->type != EXPR_SYMBOL)
574 return 0;
575 if (!strcmp(expr->symbol_name->name, name))
576 return 1;
577 return 0;
578 }
579
580 int is_zero(struct expression *expr)
581 {
582 sval_t sval;
583
584 if (get_value(expr, &sval) && sval.value == 0)
585 return 1;
586 return 0;
587 }
588
589 int is_array(struct expression *expr)
590 {
591 struct symbol *type;
592
593 expr = strip_expr(expr);
594 if (!expr)
595 return 0;
596
597 if (expr->type == EXPR_PREOP && expr->op == '*') {
598 expr = strip_expr(expr->unop);
599 if (!expr)
600 return 0;
601 if (expr->type == EXPR_BINOP && expr->op == '+')
602 return 1;
603 }
604
605 if (expr->type != EXPR_BINOP || expr->op != '+')
606 return 0;
607
608 type = get_type(expr->left);
609 if (!type || type->type != SYM_ARRAY)
610 return 0;
611
612 return 1;
613 }
614
615 struct expression *get_array_base(struct expression *expr)
616 {
617 if (!is_array(expr))
618 return NULL;
619 expr = strip_expr(expr);
620 if (expr->type == EXPR_PREOP && expr->op == '*')
621 expr = strip_expr(expr->unop);
622 if (expr->type != EXPR_BINOP || expr->op != '+')
623 return NULL;
624 return strip_parens(expr->left);
625 }
626
627 struct expression *get_array_offset(struct expression *expr)
628 {
629 if (!is_array(expr))
630 return NULL;
631 expr = strip_expr(expr);
632 if (expr->type == EXPR_PREOP && expr->op == '*')
633 expr = strip_expr(expr->unop);
634 if (expr->type != EXPR_BINOP || expr->op != '+')
635 return NULL;
636 return strip_parens(expr->right);
637 }
638
639 const char *show_state(struct smatch_state *state)
640 {
641 if (!state)
642 return NULL;
643 return state->name;
644 }
645
646 struct statement *get_expression_statement(struct expression *expr)
647 {
648 /* What are those things called? if (({....; ret;})) { ...*/
649
650 if (expr->type != EXPR_PREOP)
651 return NULL;
652 if (expr->op != '(')
653 return NULL;
654 if (!expr->unop)
655 return NULL;
656 if (expr->unop->type != EXPR_STATEMENT)
657 return NULL;
658 if (expr->unop->statement->type != STMT_COMPOUND)
659 return NULL;
660 return expr->unop->statement;
661 }
662
663 struct expression *strip_parens(struct expression *expr)
664 {
665 if (!expr)
666 return NULL;
667
668 if (expr->type == EXPR_PREOP) {
669 if (!expr->unop)
670 return expr; /* parsing invalid code */
671
672 if (expr->op == '(' && expr->unop->type == EXPR_STATEMENT &&
673 expr->unop->statement->type == STMT_COMPOUND)
674 return expr;
675 if (expr->op == '(')
676 return strip_parens(expr->unop);
677 }
678 return expr;
679 }
680
681 static struct expression *strip_expr_helper(struct expression *expr, bool set_parent)
682 {
683 if (!expr)
684 return NULL;
685
686 switch (expr->type) {
687 case EXPR_FORCE_CAST:
688 case EXPR_CAST:
689 if (set_parent)
690 expr_set_parent_expr(expr->cast_expression, expr);
691
692 if (!expr->cast_expression)
693 return expr;
694 return strip_expr_helper(expr->cast_expression, set_parent);
695 case EXPR_PREOP: {
696 struct expression *unop;
697
698 if (!expr->unop) /* parsing invalid code */
699 return expr;
700 if (set_parent)
701 expr_set_parent_expr(expr->unop, expr);
702
703
704 if (expr->op == '(' && expr->unop->type == EXPR_STATEMENT &&
705 expr->unop->statement->type == STMT_COMPOUND)
706 return expr;
707
708 unop = strip_expr_helper(expr->unop, set_parent);
709
710 if (expr->op == '*' && unop &&
711 unop->type == EXPR_PREOP && unop->op == '&') {
712 struct symbol *type = get_type(unop->unop);
713
714 if (type && type->type == SYM_ARRAY)
715 return expr;
716 return strip_expr_helper(unop->unop, set_parent);
717 }
718
719 if (expr->op == '(')
720 return unop;
721
722 return expr;
723 }
724 case EXPR_CONDITIONAL:
725 if (known_condition_true(expr->conditional)) {
726 if (expr->cond_true) {
727 if (set_parent)
728 expr_set_parent_expr(expr->cond_true, expr);
729 return strip_expr_helper(expr->cond_true, set_parent);
730 }
731 if (set_parent)
732 expr_set_parent_expr(expr->conditional, expr);
733 return strip_expr_helper(expr->conditional, set_parent);
734 }
735 if (known_condition_false(expr->conditional)) {
736 if (set_parent)
737 expr_set_parent_expr(expr->cond_false, expr);
738 return strip_expr_helper(expr->cond_false, set_parent);
739 }
740 return expr;
741 case EXPR_CALL:
742 if (sym_name_is("__builtin_expect", expr->fn) ||
743 sym_name_is("__builtin_bswap16", expr->fn) ||
744 sym_name_is("__builtin_bswap32", expr->fn) ||
745 sym_name_is("__builtin_bswap64", expr->fn)) {
746 expr = get_argument_from_call_expr(expr->args, 0);
747 return strip_expr_helper(expr, set_parent);
748 }
749 return expr;
750 }
751 return expr;
752 }
753
754 struct expression *strip_expr(struct expression *expr)
755 {
756 return strip_expr_helper(expr, false);
757 }
758
759 struct expression *strip_expr_set_parent(struct expression *expr)
760 {
761 return strip_expr_helper(expr, true);
762 }
763
764 static void delete_state_tracker(struct tracker *t)
765 {
766 delete_state(t->owner, t->name, t->sym);
767 __free_tracker(t);
768 }
769
770 void scoped_state(int my_id, const char *name, struct symbol *sym)
771 {
772 struct tracker *t;
773
774 t = alloc_tracker(my_id, name, sym);
775 add_scope_hook((scope_hook *)&delete_state_tracker, t);
776 }
777
778 int is_error_return(struct expression *expr)
779 {
780 struct symbol *cur_func = cur_func_sym;
781 struct range_list *rl;
782 sval_t sval;
783
784 if (!expr)
785 return 0;
786 if (cur_func->type != SYM_NODE)
787 return 0;
788 cur_func = get_base_type(cur_func);
789 if (cur_func->type != SYM_FN)
790 return 0;
791 cur_func = get_base_type(cur_func);
792 if (cur_func == &void_ctype)
793 return 0;
794 if (option_project == PROJ_KERNEL &&
795 get_implied_rl(expr, &rl) &&
796 rl_type(rl) == &int_ctype &&
797 sval_is_negative(rl_min(rl)) &&
798 rl_max(rl).value == -1)
799 return 1;
800 if (!get_implied_value(expr, &sval))
801 return 0;
802 if (sval.value < 0)
803 return 1;
804 if (cur_func->type == SYM_PTR && sval.value == 0)
805 return 1;
806 return 0;
807 }
808
809 int getting_address(void)
810 {
811 struct expression *tmp;
812 int i = 0;
813 int dot_ops = 0;
814
815 FOR_EACH_PTR_REVERSE(big_expression_stack, tmp) {
816 if (!i++)
817 continue;
818 if (tmp->type == EXPR_PREOP && tmp->op == '(')
819 continue;
820 if (tmp->op == '.' && !dot_ops++)
821 continue;
822 if (tmp->op == '&')
823 return 1;
824 return 0;
825 } END_FOR_EACH_PTR_REVERSE(tmp);
826 return 0;
827 }
828
829 int get_struct_and_member(struct expression *expr, const char **type, const char **member)
830 {
831 struct symbol *sym;
832
833 expr = strip_expr(expr);
834 if (expr->type != EXPR_DEREF)
835 return 0;
836 if (!expr->member)
837 return 0;
838
839 sym = get_type(expr->deref);
840 if (!sym)
841 return 0;
842 if (sym->type == SYM_UNION)
843 return 0;
844 if (!sym->ident)
845 return 0;
846
847 *type = sym->ident->name;
848 *member = expr->member->name;
849 return 1;
850 }
851
852 char *get_member_name(struct expression *expr)
853 {
854 char buf[256];
855 struct symbol *sym;
856
857 expr = strip_expr(expr);
858 if (!expr || expr->type != EXPR_DEREF)
859 return NULL;
860 if (!expr->member)
861 return NULL;
862
863 sym = get_type(expr->deref);
864 if (!sym)
865 return NULL;
866 if (sym->type == SYM_UNION) {
867 snprintf(buf, sizeof(buf), "(union %s)->%s",
868 sym->ident ? sym->ident->name : "anonymous",
869 expr->member->name);
870 return alloc_string(buf);
871 }
872 if (!sym->ident)
873 return NULL;
874 snprintf(buf, sizeof(buf), "(struct %s)->%s", sym->ident->name, expr->member->name);
875 return alloc_string(buf);
876 }
877
878 int cmp_pos(struct position pos1, struct position pos2)
879 {
880 /* the stream position is ... */
881 if (pos1.stream > pos2.stream)
882 return -1;
883 if (pos1.stream < pos2.stream)
884 return 1;
885
886 if (pos1.line < pos2.line)
887 return -1;
888 if (pos1.line > pos2.line)
889 return 1;
890
891 if (pos1.pos < pos2.pos)
892 return -1;
893 if (pos1.pos > pos2.pos)
894 return 1;
895
896 return 0;
897 }
898
899 int positions_eq(struct position pos1, struct position pos2)
900 {
901 if (pos1.line != pos2.line)
902 return 0;
903 if (pos1.pos != pos2.pos)
904 return 0;
905 if (pos1.stream != pos2.stream)
906 return 0;
907 return 1;
908 }
909
910 struct statement *get_current_statement(void)
911 {
912 struct statement *prev, *tmp;
913
914 prev = last_ptr_list((struct ptr_list *)big_statement_stack);
915
916 if (!prev || !get_macro_name(prev->pos))
917 return prev;
918
919 FOR_EACH_PTR_REVERSE(big_statement_stack, tmp) {
920 if (positions_eq(tmp->pos, prev->pos))
921 continue;
922 if (prev->pos.line > tmp->pos.line)
923 return prev;
924 return tmp;
925 } END_FOR_EACH_PTR_REVERSE(tmp);
926 return prev;
927 }
928
929 struct statement *get_prev_statement(void)
930 {
931 struct statement *tmp;
932 int i;
933
934 i = 0;
935 FOR_EACH_PTR_REVERSE(big_statement_stack, tmp) {
936 if (i++ == 1)
937 return tmp;
938 } END_FOR_EACH_PTR_REVERSE(tmp);
939 return NULL;
940 }
941
942 struct expression *get_last_expr_from_expression_stmt(struct expression *expr)
943 {
944 struct statement *stmt;
945 struct statement *last_stmt;
946
947 while (expr->type == EXPR_PREOP && expr->op == '(')
948 expr = expr->unop;
949 if (expr->type != EXPR_STATEMENT)
950 return NULL;
951 stmt = expr->statement;
952 if (!stmt)
953 return NULL;
954 if (stmt->type == STMT_COMPOUND) {
955 last_stmt = last_ptr_list((struct ptr_list *)stmt->stmts);
956 if (!last_stmt)
957 return NULL;
958 if (last_stmt->type == STMT_LABEL)
959 last_stmt = last_stmt->label_statement;
960 if (last_stmt->type != STMT_EXPRESSION)
961 return NULL;
962 return last_stmt->expression;
963 }
964 if (stmt->type == STMT_EXPRESSION)
965 return stmt->expression;
966 return NULL;
967 }
968
969 int get_param_num_from_sym(struct symbol *sym)
970 {
971 struct symbol *tmp;
972 int i;
973
974 if (!cur_func_sym)
975 return -1;
976
977 i = 0;
978 FOR_EACH_PTR(cur_func_sym->ctype.base_type->arguments, tmp) {
979 if (tmp == sym)
980 return i;
981 i++;
982 } END_FOR_EACH_PTR(tmp);
983 return -1;
984 }
985
986 int get_param_num(struct expression *expr)
987 {
988 struct symbol *sym;
989 char *name;
990
991 if (!cur_func_sym)
992 return -1;
993 name = expr_to_var_sym(expr, &sym);
994 free_string(name);
995 if (!sym)
996 return -1;
997 return get_param_num_from_sym(sym);
998 }
999
1000 int ms_since(struct timeval *start)
1001 {
1002 struct timeval end;
1003 double diff;
1004
1005 gettimeofday(&end, NULL);
1006 diff = (end.tv_sec - start->tv_sec) * 1000.0;
1007 diff += (end.tv_usec - start->tv_usec) / 1000.0;
1008 return (int)diff;
1009 }
1010
1011 int parent_is_gone_var_sym(const char *name, struct symbol *sym)
1012 {
1013 if (!name || !sym)
1014 return 0;
1015
1016 if (parent_is_null_var_sym(name, sym) ||
1017 parent_is_free_var_sym(name, sym))
1018 return 1;
1019 return 0;
1020 }
1021
1022 int parent_is_gone(struct expression *expr)
1023 {
1024 struct symbol *sym;
1025 char *var;
1026 int ret = 0;
1027
1028 expr = strip_expr(expr);
1029 var = expr_to_var_sym(expr, &sym);
1030 if (!var || !sym)
1031 goto free;
1032 ret = parent_is_gone_var_sym(var, sym);
1033 free:
1034 free_string(var);
1035 return ret;
1036 }
1037
1038 int invert_op(int op)
1039 {
1040 switch (op) {
1041 case '*':
1042 return '/';
1043 case '/':
1044 return '*';
1045 case '+':
1046 return '-';
1047 case '-':
1048 return '+';
1049 case SPECIAL_LEFTSHIFT:
1050 return SPECIAL_RIGHTSHIFT;
1051 case SPECIAL_RIGHTSHIFT:
1052 return SPECIAL_LEFTSHIFT;
1053 }
1054 return 0;
1055 }
1056
1057 int expr_equiv(struct expression *one, struct expression *two)
1058 {
1059 struct symbol *one_sym = NULL;
1060 struct symbol *two_sym = NULL;
1061 char *one_name = NULL;
1062 char *two_name = NULL;
1063 int ret = 0;
1064
1065 if (!one || !two)
1066 return 0;
1067 if (one->type != two->type)
1068 return 0;
1069 if (is_fake_call(one) || is_fake_call(two))
1070 return 0;
1071
1072 one_name = expr_to_str_sym(one, &one_sym);
1073 if (!one_name)
1074 goto free;
1075 two_name = expr_to_str_sym(two, &two_sym);
1076 if (!two_name)
1077 goto free;
1078 if (one_sym != two_sym)
1079 goto free;
1080 /*
1081 * This is a terrible hack because expr_to_str() sometimes gives up in
1082 * the middle and just returns what it has. If you see a () you know
1083 * the string is bogus.
1084 */
1085 if (strstr(one_name, "()"))
1086 goto free;
1087 if (strcmp(one_name, two_name) == 0)
1088 ret = 1;
1089 free:
1090 free_string(one_name);
1091 free_string(two_name);
1092 return ret;
1093 }
1094
1095 void push_int(struct int_stack **stack, int num)
1096 {
1097 int *munged;
1098
1099 /*
1100 * Just put the int on directly instead of a pointer to the int.
1101 * Shift it to the left because Sparse uses the last two bits.
1102 * This is sort of a dirty hack, yes.
1103 */
1104
1105 munged = INT_PTR(num << 2);
1106
1107 add_ptr_list(stack, munged);
1108 }
1109
1110 int pop_int(struct int_stack **stack)
1111 {
1112 int *num;
1113
1114 num = last_ptr_list((struct ptr_list *)*stack);
1115 delete_ptr_list_last((struct ptr_list **)stack);
1116
1117 return PTR_INT(num) >> 2;
1118 }