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helper: segfault because of strip_expr()
[smatch.git] / smatch_flow.c
blobce7baef387e531eb6a93871d25205ebc470aa57b
1 /*
2 * Copyright (C) 2006,2008 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 #define _GNU_SOURCE 1
19 #include <unistd.h>
20 #include <stdio.h>
21 #include "token.h"
22 #include "scope.h"
23 #include "smatch.h"
24 #include "smatch_expression_stacks.h"
25 #include "smatch_extra.h"
26 #include "smatch_slist.h"
27
28 int __in_fake_assign;
29 int final_pass;
30 int __inline_call;
31 struct expression *__inline_fn;
32
33 static int __smatch_lineno = 0;
34
35 static char *base_file;
36 static const char *filename;
37 static char *pathname;
38 static char *full_filename;
39 static char *cur_func;
40 static unsigned int loop_count;
41 static int last_goto_statement_handled;
42 int __expr_stmt_count;
43 int __in_function_def;
44 static struct expression_list *switch_expr_stack = NULL;
45 static struct expression_list *post_op_stack = NULL;
46
47 struct expression_list *big_expression_stack;
48 struct statement_list *big_statement_stack;
49 int __in_pre_condition = 0;
50 int __bail_on_rest_of_function = 0;
51 static struct timeval fn_start_time;
52 char *get_function(void) { return cur_func; }
53 int get_lineno(void) { return __smatch_lineno; }
54 int inside_loop(void) { return !!loop_count; }
55 int definitely_inside_loop(void) { return !!(loop_count & ~0x80000000); }
56 struct expression *get_switch_expr(void) { return top_expression(switch_expr_stack); }
57 int in_expression_statement(void) { return !!__expr_stmt_count; }
58
59 static void split_symlist(struct symbol_list *sym_list);
60 static void split_declaration(struct symbol_list *sym_list);
61 static void split_expr_list(struct expression_list *expr_list);
62 static void add_inline_function(struct symbol *sym);
63 static void parse_inline(struct expression *expr);
64
65 int option_assume_loops = 0;
66 int option_known_conditions = 0;
67 int option_two_passes = 0;
68 struct symbol *cur_func_sym = NULL;
69 struct stree *global_states;
70
71 long long valid_ptr_min = 4096;
72 long long valid_ptr_max = LONG_MAX - 100000;
73 sval_t valid_ptr_min_sval = {
74 .type = &ptr_ctype,
75 {.value = 4096},
76 };
77 sval_t valid_ptr_max_sval = {
78 .type = &ptr_ctype,
79 {.value = LONG_MAX - 100000},
80 };
81
82 static void set_valid_ptr_max(void)
83 {
84 if (type_bits(&ptr_ctype) == 32)
85 valid_ptr_max = INT_MAX - 100000;
86 else if (type_bits(&ptr_ctype) == 64)
87 valid_ptr_max = LLONG_MAX - 100000;
88
89 valid_ptr_max_sval.value = valid_ptr_max;
90 }
91
92 int outside_of_function(void)
93 {
94 return cur_func_sym == NULL;
95 }
96
97 const char *get_filename(void)
98 {
99 if (option_info)
100 return base_file;
101 if (option_full_path)
102 return full_filename;
103 return filename;
104 }
105
106 const char *get_base_file(void)
107 {
108 return base_file;
109 }
110
111 static void set_position(struct position pos)
112 {
113 int len;
114 static int prev_stream = -1;
115
116 if (pos.stream == 0 && pos.line == 0)
117 return;
118
119 __smatch_lineno = pos.line;
120
121 if (pos.stream == prev_stream)
122 return;
123
124 filename = stream_name(pos.stream);
125
126 free(full_filename);
127 pathname = getcwd(NULL, 0);
128 if (pathname) {
129 len = strlen(pathname) + 1 + strlen(filename) + 1;
130 full_filename = malloc(len);
131 snprintf(full_filename, len, "%s/%s", pathname, filename);
132 } else {
133 full_filename = alloc_string(filename);
134 }
135 free(pathname);
136 }
137
138 static int is_inline_func(struct expression *expr)
139 {
140 if (expr->type != EXPR_SYMBOL || !expr->symbol)
141 return 0;
142 if (expr->symbol->ctype.modifiers & MOD_INLINE)
143 return 1;
144 return 0;
145 }
146
147 static int is_noreturn_func(struct expression *expr)
148 {
149 if (expr->type != EXPR_SYMBOL || !expr->symbol)
150 return 0;
151 if (expr->symbol->ctype.modifiers & MOD_NORETURN)
152 return 1;
153 return 0;
154 }
155
156 int inlinable(struct expression *expr)
157 {
158 struct symbol *sym;
159
160 if (__inline_fn) /* don't nest */
161 return 0;
162
163 if (expr->type != EXPR_SYMBOL || !expr->symbol)
164 return 0;
165 if (is_no_inline_function(expr->symbol->ident->name))
166 return 0;
167 sym = get_base_type(expr->symbol);
168 if (sym->stmt && sym->stmt->type == STMT_COMPOUND) {
169 if (ptr_list_size((struct ptr_list *)sym->stmt->stmts) <= 10)
170 return 1;
171 return 0;
172 }
173 if (sym->inline_stmt && sym->inline_stmt->type == STMT_COMPOUND) {
174 if (ptr_list_size((struct ptr_list *)sym->inline_stmt->stmts) <= 10)
175 return 1;
176 return 0;
177 }
178 return 0;
179 }
180
181 void __process_post_op_stack(void)
182 {
183 struct expression *expr;
184
185 FOR_EACH_PTR(post_op_stack, expr) {
186 __pass_to_client(expr, OP_HOOK);
187 } END_FOR_EACH_PTR(expr);
188
189 __free_ptr_list((struct ptr_list **)&post_op_stack);
190 }
191
192 void __split_expr(struct expression *expr)
193 {
194 if (!expr)
195 return;
196
197 // sm_msg(" Debug expr_type %d %s", expr->type, show_special(expr->op));
198
199 if (__in_fake_assign && expr->type != EXPR_ASSIGNMENT)
200 return;
201 if (__in_fake_assign >= 4) /* don't allow too much nesting */
202 return;
203
204 push_expression(&big_expression_stack, expr);
205 set_position(expr->pos);
206 __pass_to_client(expr, EXPR_HOOK);
207
208 switch (expr->type) {
209 case EXPR_PREOP:
210 if (expr->op == '*')
211 __pass_to_client(expr, DEREF_HOOK);
212 __split_expr(expr->unop);
213 __pass_to_client(expr, OP_HOOK);
214 break;
215 case EXPR_POSTOP:
216 __split_expr(expr->unop);
217 push_expression(&post_op_stack, expr);
218 break;
219 case EXPR_STATEMENT:
220 __expr_stmt_count++;
221 __split_stmt(expr->statement);
222 __expr_stmt_count--;
223 break;
224 case EXPR_LOGICAL:
225 case EXPR_COMPARE:
226 __pass_to_client(expr, LOGIC_HOOK);
227 __handle_logic(expr);
228 break;
229 case EXPR_BINOP:
230 __pass_to_client(expr, BINOP_HOOK);
231 case EXPR_COMMA:
232 __split_expr(expr->left);
233 __process_post_op_stack();
234 __split_expr(expr->right);
235 break;
236 case EXPR_ASSIGNMENT: {
237 struct expression *tmp;
238
239 if (!expr->right)
240 break;
241
242 __pass_to_client(expr, RAW_ASSIGNMENT_HOOK);
243
244 /* foo = !bar() */
245 if (__handle_condition_assigns(expr))
246 break;
247 /* foo = (x < 5 ? foo : 5); */
248 if (__handle_select_assigns(expr))
249 break;
250 /* foo = ({frob(); frob(); frob(); 1;}) */
251 if (__handle_expr_statement_assigns(expr))
252 break;
253
254 __split_expr(expr->right);
255 if (outside_of_function())
256 __pass_to_client(expr, GLOBAL_ASSIGNMENT_HOOK);
257 else
258 __pass_to_client(expr, ASSIGNMENT_HOOK);
259
260 __fake_struct_member_assignments(expr);
261
262 tmp = strip_expr(expr->right);
263 if (tmp->type == EXPR_CALL)
264 __pass_to_client(expr, CALL_ASSIGNMENT_HOOK);
265 if (get_macro_name(tmp->pos) &&
266 get_macro_name(expr->pos) != get_macro_name(tmp->pos))
267 __pass_to_client(expr, MACRO_ASSIGNMENT_HOOK);
268 __split_expr(expr->left);
269 break;
270 }
271 case EXPR_DEREF:
272 __pass_to_client(expr, DEREF_HOOK);
273 __split_expr(expr->deref);
274 break;
275 case EXPR_SLICE:
276 __split_expr(expr->base);
277 break;
278 case EXPR_CAST:
279 case EXPR_FORCE_CAST:
280 __pass_to_client(expr, CAST_HOOK);
281 __split_expr(expr->cast_expression);
282 break;
283 case EXPR_SIZEOF:
284 if (expr->cast_expression)
285 __pass_to_client(strip_parens(expr->cast_expression),
286 SIZEOF_HOOK);
287 break;
288 case EXPR_OFFSETOF:
289 case EXPR_ALIGNOF:
290 evaluate_expression(expr);
291 break;
292 case EXPR_CONDITIONAL:
293 case EXPR_SELECT:
294 if (known_condition_true(expr->conditional)) {
295 __split_expr(expr->cond_true);
296 break;
297 }
298 if (known_condition_false(expr->conditional)) {
299 __split_expr(expr->cond_false);
300 break;
301 }
302 __pass_to_client(expr, SELECT_HOOK);
303 __split_whole_condition(expr->conditional);
304 __split_expr(expr->cond_true);
305 __push_true_states();
306 __use_false_states();
307 __split_expr(expr->cond_false);
308 __merge_true_states();
309 break;
310 case EXPR_CALL:
311 if (sym_name_is("__builtin_constant_p", expr->fn))
312 break;
313 split_expr_list(expr->args);
314 __split_expr(expr->fn);
315 if (is_inline_func(expr->fn))
316 add_inline_function(expr->fn->symbol);
317 if (inlinable(expr->fn))
318 __inline_call = 1;
319 __process_post_op_stack();
320 __pass_to_client(expr, FUNCTION_CALL_HOOK);
321 __inline_call = 0;
322 if (inlinable(expr->fn)) {
323 parse_inline(expr);
324 }
325 __pass_to_client(expr, CALL_HOOK_AFTER_INLINE);
326 if (is_noreturn_func(expr->fn))
327 nullify_path();
328 break;
329 case EXPR_INITIALIZER:
330 split_expr_list(expr->expr_list);
331 break;
332 case EXPR_IDENTIFIER:
333 __split_expr(expr->ident_expression);
334 break;
335 case EXPR_INDEX:
336 __split_expr(expr->idx_expression);
337 break;
338 case EXPR_POS:
339 __split_expr(expr->init_expr);
340 break;
341 case EXPR_SYMBOL:
342 __pass_to_client(expr, SYM_HOOK);
343 break;
344 case EXPR_STRING:
345 __pass_to_client(expr, STRING_HOOK);
346 break;
347 default:
348 break;
349 };
350 pop_expression(&big_expression_stack);
351 }
352
353 static int is_forever_loop(struct statement *stmt)
354 {
355 struct expression *expr;
356
357 expr = strip_expr(stmt->iterator_pre_condition);
358 if (!expr)
359 expr = stmt->iterator_post_condition;
360 if (!expr) {
361 /* this is a for(;;) loop... */
362 return 1;
363 }
364
365 if (expr->type == EXPR_VALUE && expr->value == 1)
366 return 1;
367
368 return 0;
369 }
370
371 static int loop_num;
372 static char *get_loop_name(int num)
373 {
374 char buf[256];
375
376 snprintf(buf, 255, "-loop%d", num);
377 buf[255] = '\0';
378 return alloc_sname(buf);
379 }
380
381 /*
382 * Pre Loops are while and for loops.
383 */
384 static void handle_pre_loop(struct statement *stmt)
385 {
386 int once_through; /* we go through the loop at least once */
387 struct sm_state *extra_sm = NULL;
388 int unchanged = 0;
389 char *loop_name;
390 struct stree *stree = NULL;
391 struct sm_state *sm = NULL;
392
393 loop_name = get_loop_name(loop_num);
394 loop_num++;
395
396 __split_stmt(stmt->iterator_pre_statement);
397
398 once_through = implied_condition_true(stmt->iterator_pre_condition);
399
400 loop_count++;
401 __push_continues();
402 __push_breaks();
403
404 __merge_gotos(loop_name);
405
406 extra_sm = __extra_handle_canonical_loops(stmt, &stree);
407 __in_pre_condition++;
408 __pass_to_client(stmt, PRELOOP_HOOK);
409 __split_whole_condition(stmt->iterator_pre_condition);
410 __in_pre_condition--;
411 FOR_EACH_SM(stree, sm) {
412 set_state(sm->owner, sm->name, sm->sym, sm->state);
413 } END_FOR_EACH_SM(sm);
414 free_stree(&stree);
415 if (extra_sm)
416 extra_sm = get_sm_state(extra_sm->owner, extra_sm->name, extra_sm->sym);
417
418 if (option_assume_loops)
419 once_through = 1;
420
421 __split_stmt(stmt->iterator_statement);
422 __warn_on_silly_pre_loops();
423 if (is_forever_loop(stmt)) {
424 __merge_continues();
425 __save_gotos(loop_name);
426
427 __push_fake_cur_stree();
428 __split_stmt(stmt->iterator_post_statement);
429 stree = __pop_fake_cur_stree();
430
431 __discard_false_states();
432 __use_breaks();
433
434 if (!__path_is_null())
435 __merge_stree_into_cur(stree);
436 free_stree(&stree);
437 } else {
438 __merge_continues();
439 unchanged = __iterator_unchanged(extra_sm);
440 __split_stmt(stmt->iterator_post_statement);
441 __save_gotos(loop_name);
442 __in_pre_condition++;
443 __split_whole_condition(stmt->iterator_pre_condition);
444 __in_pre_condition--;
445 nullify_path();
446 __merge_false_states();
447 if (once_through)
448 __discard_false_states();
449 else
450 __merge_false_states();
451
452 if (extra_sm && unchanged)
453 __extra_pre_loop_hook_after(extra_sm,
454 stmt->iterator_post_statement,
455 stmt->iterator_pre_condition);
456 __merge_breaks();
457 }
458 loop_count--;
459 }
460
461 /*
462 * Post loops are do {} while();
463 */
464 static void handle_post_loop(struct statement *stmt)
465 {
466 char *loop_name;
467
468 loop_name = get_loop_name(loop_num);
469 loop_num++;
470 loop_count++;
471
472 __push_continues();
473 __push_breaks();
474 __merge_gotos(loop_name);
475 __split_stmt(stmt->iterator_statement);
476 __merge_continues();
477 if (!is_zero(stmt->iterator_post_condition))
478 __save_gotos(loop_name);
479
480 if (is_forever_loop(stmt)) {
481 __use_breaks();
482 } else {
483 __split_whole_condition(stmt->iterator_post_condition);
484 __use_false_states();
485 __merge_breaks();
486 }
487 loop_count--;
488 }
489
490 static int empty_statement(struct statement *stmt)
491 {
492 if (!stmt)
493 return 0;
494 if (stmt->type == STMT_EXPRESSION && !stmt->expression)
495 return 1;
496 return 0;
497 }
498
499 static int last_stmt_on_same_line(void)
500 {
501 struct statement *stmt;
502 int i = 0;
503
504 FOR_EACH_PTR_REVERSE(big_statement_stack, stmt) {
505 if (!i++)
506 continue;
507 if (stmt->pos.line == get_lineno())
508 return 1;
509 return 0;
510 } END_FOR_EACH_PTR_REVERSE(stmt);
511 return 0;
512 }
513
514 static void split_asm_constraints(struct expression_list *expr_list)
515 {
516 struct expression *expr;
517 int state = 0;
518
519 FOR_EACH_PTR(expr_list, expr) {
520 switch (state) {
521 case 0: /* identifier */
522 case 1: /* constraint */
523 state++;
524 continue;
525 case 2: /* expression */
526 state = 0;
527 __split_expr(expr);
528 continue;
529 }
530 } END_FOR_EACH_PTR(expr);
531 }
532
533 static int is_case_val(struct statement *stmt, sval_t sval)
534 {
535 sval_t case_sval;
536
537 if (stmt->type != STMT_CASE)
538 return 0;
539 if (!stmt->case_expression) {
540 __set_default();
541 return 1;
542 }
543 if (!get_value(stmt->case_expression, &case_sval))
544 return 0;
545 if (case_sval.value == sval.value)
546 return 1;
547 return 0;
548 }
549
550 static void split_known_switch(struct statement *stmt, sval_t sval)
551 {
552 struct statement *tmp;
553
554 __split_expr(stmt->switch_expression);
555
556 push_expression(&switch_expr_stack, stmt->switch_expression);
557 __save_switch_states(top_expression(switch_expr_stack));
558 nullify_path();
559 __push_default();
560 __push_breaks();
561
562 stmt = stmt->switch_statement;
563
564 __push_scope_hooks();
565 FOR_EACH_PTR(stmt->stmts, tmp) {
566 __smatch_lineno = tmp->pos.line;
567 if (is_case_val(tmp, sval)) {
568 __merge_switches(top_expression(switch_expr_stack),
569 stmt->case_expression);
570 __pass_case_to_client(top_expression(switch_expr_stack),
571 stmt->case_expression);
572 }
573 if (__path_is_null())
574 continue;
575 __split_stmt(tmp);
576 if (__path_is_null()) {
577 __set_default();
578 goto out;
579 }
580 } END_FOR_EACH_PTR(tmp);
581 out:
582 __call_scope_hooks();
583 if (!__pop_default())
584 __merge_switches(top_expression(switch_expr_stack),
585 NULL);
586 __discard_switches();
587 __merge_breaks();
588 pop_expression(&switch_expr_stack);
589 }
590
591 static int taking_too_long(void)
592 {
593 int ms;
594
595 ms = ms_since(&fn_start_time);
596 if (ms > 1000 * 60 * 5) /* five minutes */
597 return 1;
598 return 0;
599 }
600
601 static int is_last_stmt(struct statement *cur_stmt)
602 {
603 struct symbol *fn = get_base_type(cur_func_sym);
604 struct statement *stmt;
605
606 if (!fn)
607 return 0;
608 stmt = fn->stmt;
609 if (!stmt)
610 stmt = fn->inline_stmt;
611 if (!stmt || stmt->type != STMT_COMPOUND)
612 return 0;
613 stmt = last_ptr_list((struct ptr_list *)stmt->stmts);
614 if (stmt && stmt->type == STMT_LABEL)
615 stmt = stmt->label_statement;
616 if (stmt == cur_stmt)
617 return 1;
618 return 0;
619 }
620
621 static void handle_backward_goto(struct statement *goto_stmt)
622 {
623 const char *goto_name, *label_name;
624 struct statement *func_stmt;
625 struct symbol *base_type = get_base_type(cur_func_sym);
626 struct statement *tmp;
627 int found = 0;
628
629 if (!option_info)
630 return;
631 if (last_goto_statement_handled)
632 return;
633 last_goto_statement_handled = 1;
634
635 if (!goto_stmt->goto_label ||
636 goto_stmt->goto_label->type != SYM_LABEL ||
637 !goto_stmt->goto_label->ident)
638 return;
639 goto_name = goto_stmt->goto_label->ident->name;
640
641 func_stmt = base_type->stmt;
642 if (!func_stmt)
643 func_stmt = base_type->inline_stmt;
644 if (!func_stmt)
645 return;
646 if (func_stmt->type != STMT_COMPOUND)
647 return;
648
649 FOR_EACH_PTR(func_stmt->stmts, tmp) {
650 if (!found) {
651 if (tmp->type != STMT_LABEL)
652 continue;
653 if (!tmp->label_identifier ||
654 tmp->label_identifier->type != SYM_LABEL ||
655 !tmp->label_identifier->ident)
656 continue;
657 label_name = tmp->label_identifier->ident->name;
658 if (strcmp(goto_name, label_name) != 0)
659 continue;
660 found = 1;
661 }
662 __split_stmt(tmp);
663 } END_FOR_EACH_PTR(tmp);
664 }
665
666 static void fake_a_return(void)
667 {
668 struct symbol *return_type;
669
670 nullify_path();
671 __unnullify_path();
672
673 return_type = get_real_base_type(cur_func_sym);
674 return_type = get_real_base_type(return_type);
675 if (return_type != &void_ctype) {
676 __pass_to_client(unknown_value_expression(NULL), RETURN_HOOK);
677 nullify_path();
678 }
679
680 __pass_to_client(cur_func_sym, END_FUNC_HOOK);
681 __pass_to_client(cur_func_sym, AFTER_FUNC_HOOK);
682 }
683
684 void __split_stmt(struct statement *stmt)
685 {
686 sval_t sval;
687
688 if (!stmt)
689 goto out;
690
691 if (__bail_on_rest_of_function || out_of_memory() || taking_too_long()) {
692 static char *printed = NULL;
693
694 __bail_on_rest_of_function = 1;
695 if (printed != cur_func)
696 sm_msg("Function too hairy. Giving up.");
697 fake_a_return();
698 final_pass = 0; /* turn off sm_msg() from here */
699 printed = cur_func;
700 return;
701 }
702
703 add_ptr_list(&big_statement_stack, stmt);
704 free_expression_stack(&big_expression_stack);
705 set_position(stmt->pos);
706 __pass_to_client(stmt, STMT_HOOK);
707
708 switch (stmt->type) {
709 case STMT_DECLARATION:
710 split_declaration(stmt->declaration);
711 break;
712 case STMT_RETURN:
713 __split_expr(stmt->ret_value);
714 __pass_to_client(stmt->ret_value, RETURN_HOOK);
715 __process_post_op_stack();
716 nullify_path();
717 break;
718 case STMT_EXPRESSION:
719 __split_expr(stmt->expression);
720 break;
721 case STMT_COMPOUND: {
722 struct statement *tmp;
723
724 __push_scope_hooks();
725 FOR_EACH_PTR(stmt->stmts, tmp) {
726 __split_stmt(tmp);
727 } END_FOR_EACH_PTR(tmp);
728 __call_scope_hooks();
729 break;
730 }
731 case STMT_IF:
732 if (known_condition_true(stmt->if_conditional)) {
733 __split_stmt(stmt->if_true);
734 break;
735 }
736 if (known_condition_false(stmt->if_conditional)) {
737 __split_stmt(stmt->if_false);
738 break;
739 }
740 if (option_known_conditions &&
741 implied_condition_true(stmt->if_conditional)) {
742 sm_info("this condition is true.");
743 __split_stmt(stmt->if_true);
744 break;
745 }
746 if (option_known_conditions &&
747 implied_condition_false(stmt->if_conditional)) {
748 sm_info("this condition is false.");
749 __split_stmt(stmt->if_false);
750 break;
751 }
752 __split_whole_condition(stmt->if_conditional);
753 __split_stmt(stmt->if_true);
754 if (empty_statement(stmt->if_true) &&
755 last_stmt_on_same_line() &&
756 !get_macro_name(stmt->if_true->pos))
757 sm_msg("warn: if();");
758 __push_true_states();
759 __use_false_states();
760 __split_stmt(stmt->if_false);
761 __merge_true_states();
762 break;
763 case STMT_ITERATOR:
764 if (stmt->iterator_pre_condition)
765 handle_pre_loop(stmt);
766 else if (stmt->iterator_post_condition)
767 handle_post_loop(stmt);
768 else {
769 // these are for(;;) type loops.
770 handle_pre_loop(stmt);
771 }
772 break;
773 case STMT_SWITCH:
774 if (get_value(stmt->switch_expression, &sval)) {
775 split_known_switch(stmt, sval);
776 break;
777 }
778 __split_expr(stmt->switch_expression);
779 push_expression(&switch_expr_stack, stmt->switch_expression);
780 __save_switch_states(top_expression(switch_expr_stack));
781 nullify_path();
782 __push_default();
783 __push_breaks();
784 __split_stmt(stmt->switch_statement);
785 if (!__pop_default())
786 __merge_switches(top_expression(switch_expr_stack),
787 NULL);
788 __discard_switches();
789 __merge_breaks();
790 pop_expression(&switch_expr_stack);
791 break;
792 case STMT_CASE:
793 __merge_switches(top_expression(switch_expr_stack),
794 stmt->case_expression);
795 __pass_case_to_client(top_expression(switch_expr_stack),
796 stmt->case_expression);
797 if (!stmt->case_expression)
798 __set_default();
799 __split_expr(stmt->case_expression);
800 __split_expr(stmt->case_to);
801 __split_stmt(stmt->case_statement);
802 break;
803 case STMT_LABEL:
804 if (stmt->label_identifier &&
805 stmt->label_identifier->type == SYM_LABEL &&
806 stmt->label_identifier->ident) {
807 loop_count |= 0x80000000;
808 __merge_gotos(stmt->label_identifier->ident->name);
809 }
810 __split_stmt(stmt->label_statement);
811 break;
812 case STMT_GOTO:
813 __split_expr(stmt->goto_expression);
814 if (stmt->goto_label && stmt->goto_label->type == SYM_NODE) {
815 if (!strcmp(stmt->goto_label->ident->name, "break")) {
816 __process_breaks();
817 } else if (!strcmp(stmt->goto_label->ident->name,
818 "continue")) {
819 __process_continues();
820 }
821 } else if (stmt->goto_label &&
822 stmt->goto_label->type == SYM_LABEL &&
823 stmt->goto_label->ident) {
824 __save_gotos(stmt->goto_label->ident->name);
825 }
826 nullify_path();
827 if (is_last_stmt(stmt))
828 handle_backward_goto(stmt);
829 break;
830 case STMT_NONE:
831 break;
832 case STMT_ASM:
833 __pass_to_client(stmt, ASM_HOOK);
834 __split_expr(stmt->asm_string);
835 split_asm_constraints(stmt->asm_outputs);
836 split_asm_constraints(stmt->asm_inputs);
837 split_asm_constraints(stmt->asm_clobbers);
838 break;
839 case STMT_CONTEXT:
840 break;
841 case STMT_RANGE:
842 __split_expr(stmt->range_expression);
843 __split_expr(stmt->range_low);
844 __split_expr(stmt->range_high);
845 break;
846 }
847 __pass_to_client(stmt, STMT_HOOK_AFTER);
848 out:
849 __process_post_op_stack();
850 }
851
852 static void split_expr_list(struct expression_list *expr_list)
853 {
854 struct expression *expr;
855
856 FOR_EACH_PTR(expr_list, expr) {
857 __split_expr(expr);
858 __process_post_op_stack();
859 } END_FOR_EACH_PTR(expr);
860 }
861
862 static void split_sym(struct symbol *sym)
863 {
864 if (!sym)
865 return;
866 if (!(sym->namespace & NS_SYMBOL))
867 return;
868
869 __split_stmt(sym->stmt);
870 __split_expr(sym->array_size);
871 split_symlist(sym->arguments);
872 split_symlist(sym->symbol_list);
873 __split_stmt(sym->inline_stmt);
874 split_symlist(sym->inline_symbol_list);
875 }
876
877 static void split_symlist(struct symbol_list *sym_list)
878 {
879 struct symbol *sym;
880
881 FOR_EACH_PTR(sym_list, sym) {
882 split_sym(sym);
883 } END_FOR_EACH_PTR(sym);
884 }
885
886 typedef void (fake_cb)(struct expression *expr);
887
888 static int member_to_number(struct expression *expr, struct ident *member)
889 {
890 struct symbol *type, *tmp;
891 char *name;
892 int i;
893
894 if (!member)
895 return -1;
896 name = member->name;
897
898 type = get_type(expr);
899 if (!type || type->type != SYM_STRUCT)
900 return -1;
901
902 i = -1;
903 FOR_EACH_PTR(type->symbol_list, tmp) {
904 i++;
905 if (!tmp->ident)
906 continue;
907 if (strcmp(name, tmp->ident->name) == 0)
908 return i;
909 } END_FOR_EACH_PTR(tmp);
910 return -1;
911 }
912
913 static struct ident *number_to_member(struct expression *expr, int num)
914 {
915 struct symbol *type, *member;
916 int i = 0;
917
918 type = get_type(expr);
919 if (!type || type->type != SYM_STRUCT)
920 return NULL;
921
922 FOR_EACH_PTR(type->symbol_list, member) {
923 if (i == num)
924 return member->ident;
925 i++;
926 } END_FOR_EACH_PTR(member);
927 return NULL;
928 }
929
930 static void fake_element_assigns_helper(struct expression *array, struct expression_list *expr_list, fake_cb *fake_cb);
931
932 struct member_set {
933 struct ident *ident;
934 int set;
935 };
936
937 static struct member_set *alloc_member_set(struct symbol *type)
938 {
939 struct member_set *member_set;
940 struct symbol *member;
941 int member_count;
942 int member_idx;
943
944 member_count = ptr_list_size((struct ptr_list *)type->symbol_list);
945 member_set = malloc(member_count * sizeof(*member_set));
946 member_idx = 0;
947 FOR_EACH_PTR(type->symbol_list, member) {
948 member_set[member_idx].ident = member->ident;
949 member_set[member_idx].set = 0;
950 member_idx++;
951 } END_FOR_EACH_PTR(member);
952
953 return member_set;
954 }
955
956 static void mark_member_as_set(struct symbol *type, struct member_set *member_set, struct ident *ident)
957 {
958 int member_count = ptr_list_size((struct ptr_list *)type->symbol_list);
959 int i;
960
961 for (i = 0; i < member_count; i++) {
962 if (member_set[i].ident == ident) {
963 member_set[i].set = 1;
964 return;
965 }
966 }
967 // crap. this is buggy.
968 // sm_msg("internal smatch error in initializer %s.%s", type->ident->name, ident->name);
969 }
970
971 static void set_unset_to_zero(struct expression *symbol, struct symbol *type, struct member_set *member_set)
972 {
973 struct expression *deref, *assign;
974 struct symbol *member, *member_type;
975 int member_idx;
976
977 member_idx = 0;
978 FOR_EACH_PTR(type->symbol_list, member) {
979 if (!member->ident || member_set[member_idx].set) {
980 member_idx++;
981 continue;
982 }
983 member_type = get_real_base_type(member);
984 if (!member_type || member_type->type == SYM_ARRAY) {
985 member_idx++;
986 continue;
987 }
988 /* TODO: this should be handled recursively and not ignored */
989 if (member_type->type == SYM_STRUCT || member_type->type == SYM_UNION) {
990 member_idx++;
991 continue;
992 }
993 deref = member_expression(symbol, '.', member->ident);
994 assign = assign_expression(deref, zero_expr());
995 __split_expr(assign);
996 member_idx++;
997 } END_FOR_EACH_PTR(member);
998
999 }
1000
1001 static void fake_member_assigns_helper(struct expression *symbol, struct expression_list *members, fake_cb *fake_cb)
1002 {
1003 struct expression *deref, *assign, *tmp;
1004 struct symbol *struct_type, *type;
1005 struct ident *member;
1006 int member_idx;
1007 struct member_set *member_set;
1008
1009 struct_type = get_type(symbol);
1010 if (!struct_type ||
1011 (struct_type->type != SYM_STRUCT && struct_type->type != SYM_UNION))
1012 return;
1013
1014 member_set = alloc_member_set(struct_type);
1015
1016 member_idx = 0;
1017 FOR_EACH_PTR(members, tmp) {
1018 member = number_to_member(symbol, member_idx);
1019 while (tmp->type == EXPR_IDENTIFIER) {
1020 member = tmp->expr_ident;
1021 member_idx = member_to_number(symbol, member);
1022 tmp = tmp->ident_expression;
1023 }
1024 mark_member_as_set(struct_type, member_set, member);
1025 member_idx++;
1026 deref = member_expression(symbol, '.', member);
1027 if (tmp->type == EXPR_INITIALIZER) {
1028 type = get_type(deref);
1029 if (type && type->type == SYM_ARRAY)
1030 fake_element_assigns_helper(deref, tmp->expr_list, fake_cb);
1031 else
1032 fake_member_assigns_helper(deref, tmp->expr_list, fake_cb);
1033 } else {
1034 assign = assign_expression(deref, tmp);
1035 fake_cb(assign);
1036 }
1037 } END_FOR_EACH_PTR(tmp);
1038
1039 set_unset_to_zero(symbol, struct_type, member_set);
1040 }
1041
1042 static void fake_member_assigns(struct symbol *sym, fake_cb *fake_cb)
1043 {
1044 fake_member_assigns_helper(symbol_expression(sym),
1045 sym->initializer->expr_list, fake_cb);
1046 }
1047
1048 static void fake_element_assigns_helper(struct expression *array, struct expression_list *expr_list, fake_cb *fake_cb)
1049 {
1050 struct expression *offset, *binop, *assign, *tmp;
1051 struct symbol *type;
1052 int idx;
1053
1054 idx = 0;
1055 FOR_EACH_PTR(expr_list, tmp) {
1056 if (tmp->type == EXPR_INDEX) {
1057 if (tmp->idx_from != tmp->idx_to)
1058 return;
1059 idx = tmp->idx_from;
1060 if (!tmp->idx_expression)
1061 goto next;
1062 tmp = tmp->idx_expression;
1063 }
1064 offset = value_expr(idx);
1065 binop = array_element_expression(array, offset);
1066 if (tmp->type == EXPR_INITIALIZER) {
1067 type = get_type(binop);
1068 if (type && type->type == SYM_ARRAY)
1069 fake_element_assigns_helper(binop, tmp->expr_list, fake_cb);
1070 else
1071 fake_member_assigns_helper(binop, tmp->expr_list, fake_cb);
1072 } else {
1073 assign = assign_expression(binop, tmp);
1074 fake_cb(assign);
1075 }
1076 next:
1077 idx++;
1078 } END_FOR_EACH_PTR(tmp);
1079 }
1080
1081 static void fake_element_assigns(struct symbol *sym, fake_cb *fake_cb)
1082 {
1083 fake_element_assigns_helper(symbol_expression(sym), sym->initializer->expr_list, fake_cb);
1084 }
1085
1086 static void fake_assign_expr(struct symbol *sym)
1087 {
1088 struct expression *assign, *symbol;
1089
1090 symbol = symbol_expression(sym);
1091 assign = assign_expression(symbol, sym->initializer);
1092 __split_expr(assign);
1093 }
1094
1095 static void call_split_expr(struct expression *expr)
1096 {
1097 __split_expr(expr);
1098 }
1099
1100 static void do_initializer_stuff(struct symbol *sym)
1101 {
1102 if (!sym->initializer)
1103 return;
1104
1105 if (sym->initializer->type == EXPR_INITIALIZER) {
1106 if (get_real_base_type(sym)->type == SYM_ARRAY)
1107 fake_element_assigns(sym, call_split_expr);
1108 else
1109 fake_member_assigns(sym, call_split_expr);
1110 } else {
1111 fake_assign_expr(sym);
1112 }
1113 }
1114
1115 static void split_declaration(struct symbol_list *sym_list)
1116 {
1117 struct symbol *sym;
1118
1119 FOR_EACH_PTR(sym_list, sym) {
1120 __pass_to_client(sym, DECLARATION_HOOK);
1121 do_initializer_stuff(sym);
1122 split_sym(sym);
1123 } END_FOR_EACH_PTR(sym);
1124 }
1125
1126 static void call_global_assign_hooks(struct expression *assign)
1127 {
1128 __pass_to_client(assign, GLOBAL_ASSIGNMENT_HOOK);
1129 }
1130
1131 static void fake_global_assign(struct symbol *sym)
1132 {
1133 struct expression *assign, *symbol;
1134
1135 if (get_real_base_type(sym)->type == SYM_ARRAY) {
1136 if (sym->initializer && sym->initializer->type == EXPR_INITIALIZER) {
1137 fake_element_assigns(sym, call_global_assign_hooks);
1138 } else if (sym->initializer) {
1139 symbol = symbol_expression(sym);
1140 assign = assign_expression(symbol, sym->initializer);
1141 __pass_to_client(assign, GLOBAL_ASSIGNMENT_HOOK);
1142 } else {
1143 fake_element_assigns_helper(symbol_expression(sym), NULL, call_global_assign_hooks);
1144 }
1145 } else if (get_real_base_type(sym)->type == SYM_STRUCT) {
1146 if (sym->initializer && sym->initializer->type == EXPR_INITIALIZER) {
1147 fake_member_assigns(sym, call_global_assign_hooks);
1148 } else if (sym->initializer) {
1149 symbol = symbol_expression(sym);
1150 assign = assign_expression(symbol, sym->initializer);
1151 __pass_to_client(assign, GLOBAL_ASSIGNMENT_HOOK);
1152 } else {
1153 fake_member_assigns_helper(symbol_expression(sym), NULL, call_global_assign_hooks);
1154 }
1155 } else {
1156 symbol = symbol_expression(sym);
1157 if (sym->initializer)
1158 assign = assign_expression(symbol, sym->initializer);
1159 else
1160 assign = assign_expression(symbol, zero_expr());
1161 __pass_to_client(assign, GLOBAL_ASSIGNMENT_HOOK);
1162 }
1163 }
1164
1165 static void start_function_definition(struct symbol *sym)
1166 {
1167 __in_function_def = 1;
1168 __pass_to_client(sym, FUNC_DEF_HOOK);
1169 __in_function_def = 0;
1170 __pass_to_client(sym, AFTER_DEF_HOOK);
1171
1172 }
1173
1174 static void split_function(struct symbol *sym)
1175 {
1176 struct symbol *base_type = get_base_type(sym);
1177
1178 if (!base_type->stmt && !base_type->inline_stmt)
1179 return;
1180
1181 gettimeofday(&fn_start_time, NULL);
1182 cur_func_sym = sym;
1183 if (sym->ident)
1184 cur_func = sym->ident->name;
1185 __smatch_lineno = sym->pos.line;
1186 loop_count = 0;
1187 last_goto_statement_handled = 0;
1188 sm_debug("new function: %s\n", cur_func);
1189 __stree_id = 0;
1190 if (option_two_passes) {
1191 __unnullify_path();
1192 loop_num = 0;
1193 final_pass = 0;
1194 start_function_definition(sym);
1195 __split_stmt(base_type->stmt);
1196 __split_stmt(base_type->inline_stmt);
1197 nullify_path();
1198 }
1199 __unnullify_path();
1200 loop_num = 0;
1201 final_pass = 1;
1202 start_function_definition(sym);
1203 __split_stmt(base_type->stmt);
1204 __split_stmt(base_type->inline_stmt);
1205 __pass_to_client(sym, END_FUNC_HOOK);
1206 __pass_to_client(sym, AFTER_FUNC_HOOK);
1207
1208 cur_func_sym = NULL;
1209 cur_func = NULL;
1210 clear_all_states();
1211 free_data_info_allocs();
1212 free_expression_stack(&switch_expr_stack);
1213 __free_ptr_list((struct ptr_list **)&big_statement_stack);
1214 __bail_on_rest_of_function = 0;
1215 }
1216
1217 static void parse_inline(struct expression *call)
1218 {
1219 struct symbol *base_type;
1220 int loop_num_bak = loop_num;
1221 int final_pass_bak = final_pass;
1222 char *cur_func_bak = cur_func;
1223 struct statement_list *big_statement_stack_bak = big_statement_stack;
1224 struct expression_list *big_expression_stack_bak = big_expression_stack;
1225 struct expression_list *switch_expr_stack_bak = switch_expr_stack;
1226 struct symbol *cur_func_sym_bak = cur_func_sym;
1227
1228 __pass_to_client(call, INLINE_FN_START);
1229 final_pass = 0; /* don't print anything */
1230 __inline_fn = call;
1231
1232 base_type = get_base_type(call->fn->symbol);
1233 cur_func_sym = call->fn->symbol;
1234 if (call->fn->symbol->ident)
1235 cur_func = call->fn->symbol->ident->name;
1236 else
1237 cur_func = NULL;
1238 set_position(call->fn->symbol->pos);
1239
1240 save_all_states();
1241 big_statement_stack = NULL;
1242 big_expression_stack = NULL;
1243 switch_expr_stack = NULL;
1244
1245 sm_debug("inline function: %s\n", cur_func);
1246 __unnullify_path();
1247 loop_num = 0;
1248 start_function_definition(call->fn->symbol);
1249 __split_stmt(base_type->stmt);
1250 __split_stmt(base_type->inline_stmt);
1251 __pass_to_client(call->fn->symbol, END_FUNC_HOOK);
1252 __pass_to_client(call->fn->symbol, AFTER_FUNC_HOOK);
1253
1254 free_expression_stack(&switch_expr_stack);
1255 __free_ptr_list((struct ptr_list **)&big_statement_stack);
1256 nullify_path();
1257 free_goto_stack();
1258
1259 loop_num = loop_num_bak;
1260 final_pass = final_pass_bak;
1261 cur_func_sym = cur_func_sym_bak;
1262 cur_func = cur_func_bak;
1263 big_statement_stack = big_statement_stack_bak;
1264 big_expression_stack = big_expression_stack_bak;
1265 switch_expr_stack = switch_expr_stack_bak;
1266
1267 restore_all_states();
1268 set_position(call->pos);
1269 __inline_fn = NULL;
1270 __pass_to_client(call, INLINE_FN_END);
1271 }
1272
1273 static struct symbol_list *inlines_called;
1274 static void add_inline_function(struct symbol *sym)
1275 {
1276 static struct symbol_list *already_added;
1277 struct symbol *tmp;
1278
1279 FOR_EACH_PTR(already_added, tmp) {
1280 if (tmp == sym)
1281 return;
1282 } END_FOR_EACH_PTR(tmp);
1283
1284 add_ptr_list(&already_added, sym);
1285 add_ptr_list(&inlines_called, sym);
1286 }
1287
1288 static void process_inlines(void)
1289 {
1290 struct symbol *tmp;
1291
1292 FOR_EACH_PTR(inlines_called, tmp) {
1293 split_function(tmp);
1294 } END_FOR_EACH_PTR(tmp);
1295 free_ptr_list(&inlines_called);
1296 }
1297
1298 static struct symbol *get_last_scoped_symbol(struct symbol_list *big_list, int use_static)
1299 {
1300 struct symbol *sym;
1301
1302 FOR_EACH_PTR_REVERSE(big_list, sym) {
1303 if (!sym->scope)
1304 continue;
1305 if (use_static && sym->ctype.modifiers & MOD_STATIC)
1306 return sym;
1307 if (!use_static && !(sym->ctype.modifiers & MOD_STATIC))
1308 return sym;
1309 } END_FOR_EACH_PTR_REVERSE(sym);
1310
1311 return NULL;
1312 }
1313
1314 static void split_inlines_in_scope(struct symbol *sym)
1315 {
1316 struct symbol *base;
1317 struct symbol_list *scope_list;
1318 int stream;
1319
1320 scope_list = sym->scope->symbols;
1321 stream = sym->pos.stream;
1322
1323 /* find the last static symbol in the file */
1324 FOR_EACH_PTR_REVERSE(scope_list, sym) {
1325 if (sym->pos.stream != stream)
1326 continue;
1327 if (sym->type != SYM_NODE)
1328 continue;
1329 base = get_base_type(sym);
1330 if (!base)
1331 continue;
1332 if (base->type != SYM_FN)
1333 continue;
1334 if (!base->inline_stmt)
1335 continue;
1336 add_inline_function(sym);
1337 } END_FOR_EACH_PTR_REVERSE(sym);
1338
1339 process_inlines();
1340 }
1341
1342 static void split_inlines(struct symbol_list *sym_list)
1343 {
1344 struct symbol *sym;
1345
1346 sym = get_last_scoped_symbol(sym_list, 0);
1347 if (sym)
1348 split_inlines_in_scope(sym);
1349 sym = get_last_scoped_symbol(sym_list, 1);
1350 if (sym)
1351 split_inlines_in_scope(sym);
1352 }
1353
1354 static struct stree *clone_estates_perm(struct stree *orig)
1355 {
1356 struct stree *ret = NULL;
1357 struct sm_state *tmp;
1358
1359 FOR_EACH_SM(orig, tmp) {
1360 set_state_stree_perm(&ret, tmp->owner, tmp->name, tmp->sym, clone_estate_perm(tmp->state));
1361 } END_FOR_EACH_SM(tmp);
1362
1363 return ret;
1364 }
1365
1366 static void split_functions(struct symbol_list *sym_list)
1367 {
1368 struct symbol *sym;
1369
1370 __unnullify_path();
1371 FOR_EACH_PTR(sym_list, sym) {
1372 set_position(sym->pos);
1373 if (sym->type != SYM_NODE || get_base_type(sym)->type != SYM_FN) {
1374 __pass_to_client(sym, BASE_HOOK);
1375 fake_global_assign(sym);
1376 }
1377 } END_FOR_EACH_PTR(sym);
1378 global_states = clone_estates_perm(get_all_states_stree(SMATCH_EXTRA));
1379 nullify_path();
1380
1381 FOR_EACH_PTR(sym_list, sym) {
1382 set_position(sym->pos);
1383 if (sym->type == SYM_NODE && get_base_type(sym)->type == SYM_FN) {
1384 split_function(sym);
1385 process_inlines();
1386 }
1387 } END_FOR_EACH_PTR(sym);
1388 split_inlines(sym_list);
1389 __pass_to_client(sym_list, END_FILE_HOOK);
1390 }
1391
1392 void smatch(int argc, char **argv)
1393 {
1394
1395 struct string_list *filelist = NULL;
1396 struct symbol_list *sym_list;
1397
1398 if (argc < 2) {
1399 printf("Usage: smatch [--debug] <filename.c>\n");
1400 exit(1);
1401 }
1402 sparse_initialize(argc, argv, &filelist);
1403 set_valid_ptr_max();
1404 FOR_EACH_PTR_NOTAG(filelist, base_file) {
1405 if (option_file_output) {
1406 char buf[256];
1407
1408 snprintf(buf, sizeof(buf), "%s.smatch", base_file);
1409 sm_outfd = fopen(buf, "w");
1410 if (!sm_outfd) {
1411 printf("Error: Cannot open %s\n", base_file);
1412 exit(1);
1413 }
1414 }
1415 sym_list = sparse_keep_tokens(base_file);
1416 split_functions(sym_list);
1417 } END_FOR_EACH_PTR_NOTAG(base_file);
1418 }
Static analysis for C