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param_compare_limit: don't print impossible comparisons
[smatch.git] / smatch_flow.c
bloba45c421f89b3a390a758aee87cde9a45d38d056b
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 __in_fake_struct_assign;
30 int __in_fake_var_assign;
31 int __fake_state_cnt;
32 int in_fake_env;
33 int final_pass;
34 int __inline_call;
35 struct expression *__inline_fn;
36
37 static int __smatch_lineno = 0;
38
39 static char *base_file;
40 static const char *filename;
41 static char *pathname;
42 static char *full_filename;
43 static char *full_base_file;
44 static char *cur_func;
45 static unsigned int loop_count;
46 static int last_goto_statement_handled;
47 int __expr_stmt_count;
48 int __in_function_def;
49 int __in_unmatched_hook;
50 static struct expression_list *switch_expr_stack = NULL;
51 static struct expression_list *post_op_stack = NULL;
52
53 static struct ptr_list *fn_data_list;
54 static struct ptr_list *backup;
55
56 struct expression_list *big_expression_stack;
57 struct statement_list *big_statement_stack;
58 struct statement *__prev_stmt;
59 struct statement *__cur_stmt;
60 struct statement *__next_stmt;
61 int __in_pre_condition = 0;
62 int __bail_on_rest_of_function = 0;
63 static struct timeval fn_start_time;
64 static struct timeval outer_fn_start_time;
65 char *get_function(void) { return cur_func; }
66 int get_lineno(void) { return __smatch_lineno; }
67 int inside_loop(void) { return !!loop_count; }
68 int definitely_inside_loop(void) { return !!(loop_count & ~0x08000000); }
69 struct expression *get_switch_expr(void) { return top_expression(switch_expr_stack); }
70 int in_expression_statement(void) { return !!__expr_stmt_count; }
71
72 static void split_symlist(struct symbol_list *sym_list);
73 static void split_declaration(struct symbol_list *sym_list);
74 static void split_expr_list(struct expression_list *expr_list, struct expression *parent);
75 static void split_args(struct expression *expr);
76 static struct expression *fake_a_variable_assign(struct symbol *type, struct expression *call, struct expression *expr, int nr);
77 static void add_inline_function(struct symbol *sym);
78 static void parse_inline(struct expression *expr);
79
80 int option_assume_loops = 0;
81 int option_two_passes = 0;
82 struct symbol *cur_func_sym = NULL;
83 struct stree *global_states;
84
85 const unsigned long valid_ptr_min = 4096;
86 unsigned long valid_ptr_max = ULONG_MAX & ~(MTAG_OFFSET_MASK);
87 const sval_t valid_ptr_min_sval = {
88 .type = &ptr_ctype,
89 {.value = 4096},
90 };
91 sval_t valid_ptr_max_sval = {
92 .type = &ptr_ctype,
93 {.value = ULONG_MAX & ~(MTAG_OFFSET_MASK)},
94 };
95 struct range_list *valid_ptr_rl;
96
97 void alloc_valid_ptr_rl(void)
98 {
99 valid_ptr_max = sval_type_max(&ulong_ctype).value & ~(MTAG_OFFSET_MASK);
100 valid_ptr_max_sval.value = valid_ptr_max;
101
102 valid_ptr_rl = alloc_rl(valid_ptr_min_sval, valid_ptr_max_sval);
103 valid_ptr_rl = cast_rl(&ptr_ctype, valid_ptr_rl);
104 valid_ptr_rl = clone_rl_permanent(valid_ptr_rl);
105 }
106
107 int outside_of_function(void)
108 {
109 return cur_func_sym == NULL;
110 }
111
112 const char *get_filename(void)
113 {
114 if (option_info && option_full_path)
115 return full_base_file;
116 if (option_info)
117 return base_file;
118 if (option_full_path)
119 return full_filename;
120 return filename;
121 }
122
123 const char *get_base_file(void)
124 {
125 if (option_full_path)
126 return full_base_file;
127 return base_file;
128 }
129
130 static void set_position(struct position pos)
131 {
132 int len;
133 static int prev_stream = -1;
134
135 if (in_fake_env)
136 return;
137
138 if (pos.stream == 0 && pos.line == 0)
139 return;
140
141 __smatch_lineno = pos.line;
142
143 if (pos.stream == prev_stream)
144 return;
145
146 filename = stream_name(pos.stream);
147
148 free(full_filename);
149 pathname = getcwd(NULL, 0);
150 if (pathname) {
151 len = strlen(pathname) + 1 + strlen(filename) + 1;
152 full_filename = malloc(len);
153 snprintf(full_filename, len, "%s/%s", pathname, filename);
154 } else {
155 full_filename = alloc_string(filename);
156 }
157 free(pathname);
158 }
159
160 int is_assigned_call(struct expression *expr)
161 {
162 struct expression *parent = expr_get_parent_expr(expr);
163
164 if (parent &&
165 parent->type == EXPR_ASSIGNMENT &&
166 parent->op == '=' &&
167 strip_expr(parent->right) == expr)
168 return 1;
169
170 return 0;
171 }
172
173 int is_fake_assigned_call(struct expression *expr)
174 {
175 struct expression *parent = expr_get_fake_parent_expr(expr);
176
177 if (parent &&
178 parent->type == EXPR_ASSIGNMENT &&
179 parent->op == '=' &&
180 strip_expr(parent->right) == expr)
181 return 1;
182
183 return 0;
184 }
185
186 static bool is_inline_func(struct expression *expr)
187 {
188 if (expr->type != EXPR_SYMBOL || !expr->symbol)
189 return false;
190 if (!expr->symbol->definition)
191 return false;
192 if (expr->symbol->definition->ctype.modifiers & MOD_INLINE)
193 return true;
194
195 return 0;
196 }
197
198 static int is_noreturn_func(struct expression *expr)
199 {
200 if (expr->type != EXPR_SYMBOL || !expr->symbol)
201 return 0;
202 if (expr->symbol->ctype.modifiers & MOD_NORETURN)
203 return 1;
204 return 0;
205 }
206
207 static int save_func_time(void *_rl, int argc, char **argv, char **azColName)
208 {
209 unsigned long *rl = _rl;
210
211 *rl = strtoul(argv[0], NULL, 10);
212 return 0;
213 }
214
215 static int get_func_time(struct symbol *sym)
216 {
217 unsigned long time = 0;
218
219 run_sql(&save_func_time, &time,
220 "select key from return_implies where %s and type = %d;",
221 get_static_filter(sym), FUNC_TIME);
222
223 return time;
224 }
225
226 static int inline_budget = 20;
227
228 int inlinable(struct expression *expr)
229 {
230 struct symbol *sym;
231 struct statement *last_stmt = NULL;
232
233 if (__inline_fn) /* don't nest */
234 return 0;
235
236 if (expr->type != EXPR_SYMBOL || !expr->symbol)
237 return 0;
238 if (is_no_inline_function(expr->symbol->ident->name))
239 return 0;
240 sym = get_base_type(expr->symbol);
241 if (sym->stmt && sym->stmt->type == STMT_COMPOUND) {
242 if (ptr_list_size((struct ptr_list *)sym->stmt->stmts) > 10)
243 return 0;
244 if (sym->stmt->type != STMT_COMPOUND)
245 return 0;
246 last_stmt = last_ptr_list((struct ptr_list *)sym->stmt->stmts);
247 }
248 if (sym->inline_stmt && sym->inline_stmt->type == STMT_COMPOUND) {
249 if (ptr_list_size((struct ptr_list *)sym->inline_stmt->stmts) > 10)
250 return 0;
251 if (sym->inline_stmt->type != STMT_COMPOUND)
252 return 0;
253 last_stmt = last_ptr_list((struct ptr_list *)sym->inline_stmt->stmts);
254 }
255
256 if (!last_stmt)
257 return 0;
258
259 /* the magic numbers in this function are pulled out of my bum. */
260 if (last_stmt->pos.line > sym->pos.line + inline_budget)
261 return 0;
262
263 if (get_func_time(expr->symbol) >= 2)
264 return 0;
265
266 return 1;
267 }
268
269 void __process_post_op_stack(void)
270 {
271 struct expression *expr;
272
273 FOR_EACH_PTR(post_op_stack, expr) {
274 __pass_to_client(expr, OP_HOOK);
275 } END_FOR_EACH_PTR(expr);
276
277 __free_ptr_list((struct ptr_list **)&post_op_stack);
278 }
279
280 static int handle_comma_assigns(struct expression *expr)
281 {
282 struct expression *right;
283 struct expression *assign;
284
285 right = strip_expr(expr->right);
286 if (right->type != EXPR_COMMA)
287 return 0;
288
289 __split_expr(right->left);
290 __process_post_op_stack();
291
292 assign = assign_expression(expr->left, '=', right->right);
293 __split_expr(assign);
294
295 return 1;
296 }
297
298 /* This is to handle *p++ = foo; assignments */
299 static int handle_postop_assigns(struct expression *expr)
300 {
301 struct expression *left, *fake_left;
302 struct expression *assign;
303
304 left = strip_expr(expr->left);
305 if (left->type != EXPR_PREOP || left->op != '*')
306 return 0;
307 left = strip_expr(left->unop);
308 if (left->type != EXPR_POSTOP)
309 return 0;
310
311 fake_left = deref_expression(strip_expr(left->unop));
312 assign = assign_expression(fake_left, '=', expr->right);
313
314 __split_expr(assign);
315 __split_expr(expr->left);
316
317 return 1;
318 }
319
320 static int prev_expression_is_getting_address(struct expression *expr)
321 {
322 struct expression *parent;
323
324 do {
325 parent = expr_get_parent_expr(expr);
326
327 if (!parent)
328 return 0;
329 if (parent->type == EXPR_PREOP && parent->op == '&')
330 return 1;
331 if (parent->type == EXPR_PREOP && parent->op == '(')
332 goto next;
333 if (parent->type == EXPR_DEREF && parent->op == '.')
334 goto next;
335
336 return 0;
337 next:
338 expr = parent;
339 } while (1);
340 }
341
342 static void handle_builtin_overflow_func(struct expression *expr)
343 {
344 struct expression *a, *b, *res, *assign;
345 int op;
346
347 if (sym_name_is("__builtin_add_overflow", expr->fn))
348 op = '+';
349 else if (sym_name_is("__builtin_sub_overflow", expr->fn))
350 op = '-';
351 else if (sym_name_is("__builtin_mul_overflow", expr->fn))
352 op = '*';
353 else
354 return;
355
356 a = get_argument_from_call_expr(expr->args, 0);
357 b = get_argument_from_call_expr(expr->args, 1);
358 res = get_argument_from_call_expr(expr->args, 2);
359
360 assign = assign_expression(deref_expression(res), '=', binop_expression(a, op, b));
361 __split_expr(assign);
362 }
363
364 static int handle__builtin_choose_expr(struct expression *expr)
365 {
366 struct expression *const_expr, *expr1, *expr2;
367 sval_t sval;
368
369 if (!sym_name_is("__builtin_choose_expr", expr->fn))
370 return 0;
371
372 const_expr = get_argument_from_call_expr(expr->args, 0);
373 expr1 = get_argument_from_call_expr(expr->args, 1);
374 expr2 = get_argument_from_call_expr(expr->args, 2);
375
376 if (!get_value(const_expr, &sval) || !expr1 || !expr2)
377 return 0;
378 if (sval.value)
379 __split_expr(expr1);
380 else
381 __split_expr(expr2);
382 return 1;
383 }
384
385 static int handle__builtin_choose_expr_assigns(struct expression *expr)
386 {
387 struct expression *const_expr, *right, *expr1, *expr2, *fake;
388 sval_t sval;
389
390 right = strip_expr(expr->right);
391 if (right->type != EXPR_CALL)
392 return 0;
393 if (!sym_name_is("__builtin_choose_expr", right->fn))
394 return 0;
395
396 const_expr = get_argument_from_call_expr(right->args, 0);
397 expr1 = get_argument_from_call_expr(right->args, 1);
398 expr2 = get_argument_from_call_expr(right->args, 2);
399
400 if (!get_value(const_expr, &sval) || !expr1 || !expr2)
401 return 0;
402
403 fake = assign_expression(expr->left, '=', sval.value ? expr1 : expr2);
404 __split_expr(fake);
405 return 1;
406 }
407
408 void __split_expr(struct expression *expr)
409 {
410 if (!expr)
411 return;
412
413 // sm_msg(" Debug expr_type %d %s", expr->type, show_special(expr->op));
414
415 if (__in_fake_assign && expr->type != EXPR_ASSIGNMENT)
416 return;
417 if (__in_fake_assign >= 4) /* don't allow too much nesting */
418 return;
419
420 push_expression(&big_expression_stack, expr);
421 set_position(expr->pos);
422 __pass_to_client(expr, EXPR_HOOK);
423
424 switch (expr->type) {
425 case EXPR_PREOP:
426 expr_set_parent_expr(expr->unop, expr);
427
428 if (expr->op == '*' &&
429 !prev_expression_is_getting_address(expr))
430 __pass_to_client(expr, DEREF_HOOK);
431 __split_expr(expr->unop);
432 __pass_to_client(expr, OP_HOOK);
433 break;
434 case EXPR_POSTOP:
435 expr_set_parent_expr(expr->unop, expr);
436
437 __split_expr(expr->unop);
438 push_expression(&post_op_stack, expr);
439 break;
440 case EXPR_STATEMENT:
441 __expr_stmt_count++;
442 if (expr->statement && !expr->statement) {
443 stmt_set_parent_stmt(expr->statement,
444 last_ptr_list((struct ptr_list *)big_statement_stack));
445 }
446 __split_stmt(expr->statement);
447 __expr_stmt_count--;
448 break;
449 case EXPR_LOGICAL:
450 case EXPR_COMPARE:
451 expr_set_parent_expr(expr->left, expr);
452 expr_set_parent_expr(expr->right, expr);
453
454 __pass_to_client(expr, LOGIC_HOOK);
455 __handle_logic(expr);
456 break;
457 case EXPR_BINOP:
458 expr_set_parent_expr(expr->left, expr);
459 expr_set_parent_expr(expr->right, expr);
460
461 __pass_to_client(expr, BINOP_HOOK);
462 case EXPR_COMMA:
463 expr_set_parent_expr(expr->left, expr);
464 expr_set_parent_expr(expr->right, expr);
465
466 __split_expr(expr->left);
467 __process_post_op_stack();
468 __split_expr(expr->right);
469 break;
470 case EXPR_ASSIGNMENT: {
471 struct expression *right;
472
473 expr_set_parent_expr(expr->left, expr);
474 expr_set_parent_expr(expr->right, expr);
475
476 right = strip_expr(expr->right);
477 if (!right)
478 break;
479
480 __pass_to_client(expr, RAW_ASSIGNMENT_HOOK);
481
482 /* foo = !bar() */
483 if (__handle_condition_assigns(expr))
484 goto after_assign;
485 /* foo = (x < 5 ? foo : 5); */
486 if (__handle_select_assigns(expr))
487 goto after_assign;
488 /* foo = ({frob(); frob(); frob(); 1;}) */
489 if (__handle_expr_statement_assigns(expr))
490 break; // FIXME: got after
491 /* foo = (3, 4); */
492 if (handle_comma_assigns(expr))
493 goto after_assign;
494 if (handle__builtin_choose_expr_assigns(expr))
495 goto after_assign;
496 if (handle_postop_assigns(expr))
497 break; /* no need to goto after_assign */
498
499 __split_expr(expr->right);
500 if (outside_of_function())
501 __pass_to_client(expr, GLOBAL_ASSIGNMENT_HOOK);
502 else
503 __pass_to_client(expr, ASSIGNMENT_HOOK);
504
505 __fake_struct_member_assignments(expr);
506
507 /* Re-examine ->right for inlines. See the commit message */
508 right = strip_expr(expr->right);
509 if (expr->op == '=' && right->type == EXPR_CALL)
510 __pass_to_client(expr, CALL_ASSIGNMENT_HOOK);
511
512 if (get_macro_name(right->pos) &&
513 get_macro_name(expr->pos) != get_macro_name(right->pos))
514 __pass_to_client(expr, MACRO_ASSIGNMENT_HOOK);
515
516 after_assign:
517 __pass_to_client(expr, ASSIGNMENT_HOOK_AFTER);
518 __split_expr(expr->left);
519 break;
520 }
521 case EXPR_DEREF:
522 expr_set_parent_expr(expr->deref, expr);
523
524 __pass_to_client(expr, DEREF_HOOK);
525 __split_expr(expr->deref);
526 break;
527 case EXPR_SLICE:
528 expr_set_parent_expr(expr->base, expr);
529
530 __split_expr(expr->base);
531 break;
532 case EXPR_CAST:
533 case EXPR_FORCE_CAST:
534 expr_set_parent_expr(expr->cast_expression, expr);
535
536 __pass_to_client(expr, CAST_HOOK);
537 __split_expr(expr->cast_expression);
538 break;
539 case EXPR_SIZEOF:
540 if (expr->cast_expression)
541 __pass_to_client(strip_parens(expr->cast_expression),
542 SIZEOF_HOOK);
543 break;
544 case EXPR_OFFSETOF:
545 case EXPR_ALIGNOF:
546 break;
547 case EXPR_CONDITIONAL:
548 case EXPR_SELECT:
549 expr_set_parent_expr(expr->conditional, expr);
550 expr_set_parent_expr(expr->cond_true, expr);
551 expr_set_parent_expr(expr->cond_false, expr);
552
553 if (known_condition_true(expr->conditional)) {
554 __split_expr(expr->cond_true);
555 break;
556 }
557 if (known_condition_false(expr->conditional)) {
558 __split_expr(expr->cond_false);
559 break;
560 }
561 __pass_to_client(expr, SELECT_HOOK);
562 __split_whole_condition(expr->conditional);
563 __split_expr(expr->cond_true);
564 __push_true_states();
565 __use_false_states();
566 __split_expr(expr->cond_false);
567 __merge_true_states();
568 break;
569 case EXPR_CALL:
570 expr_set_parent_expr(expr->fn, expr);
571
572 if (sym_name_is("__builtin_constant_p", expr->fn))
573 break;
574 if (handle__builtin_choose_expr(expr))
575 break;
576 __split_expr(expr->fn);
577 split_args(expr);
578 if (is_inline_func(expr->fn))
579 add_inline_function(expr->fn->symbol->definition);
580 if (inlinable(expr->fn))
581 __inline_call = 1;
582 __process_post_op_stack();
583 __pass_to_client(expr, FUNCTION_CALL_HOOK_BEFORE);
584 __pass_to_client(expr, FUNCTION_CALL_HOOK);
585 __inline_call = 0;
586 if (inlinable(expr->fn))
587 parse_inline(expr);
588 __pass_to_client(expr, CALL_HOOK_AFTER_INLINE);
589 if (is_noreturn_func(expr->fn))
590 nullify_path();
591 if (!expr_get_parent_expr(expr))
592 __discard_fake_states(expr);
593 handle_builtin_overflow_func(expr);
594 break;
595 case EXPR_INITIALIZER:
596 split_expr_list(expr->expr_list, expr);
597 break;
598 case EXPR_IDENTIFIER:
599 expr_set_parent_expr(expr->ident_expression, expr);
600 __split_expr(expr->ident_expression);
601 break;
602 case EXPR_INDEX:
603 expr_set_parent_expr(expr->idx_expression, expr);
604 __split_expr(expr->idx_expression);
605 break;
606 case EXPR_POS:
607 expr_set_parent_expr(expr->init_expr, expr);
608 __split_expr(expr->init_expr);
609 break;
610 case EXPR_SYMBOL:
611 __pass_to_client(expr, SYM_HOOK);
612 break;
613 case EXPR_STRING:
614 __pass_to_client(expr, STRING_HOOK);
615 break;
616 default:
617 break;
618 };
619 __pass_to_client(expr, EXPR_HOOK_AFTER);
620 pop_expression(&big_expression_stack);
621 }
622
623 static int is_forever_loop(struct statement *stmt)
624 {
625 struct expression *expr;
626 sval_t sval;
627
628 expr = strip_expr(stmt->iterator_pre_condition);
629 if (!expr)
630 expr = stmt->iterator_post_condition;
631 if (!expr) {
632 /* this is a for(;;) loop... */
633 return 1;
634 }
635
636 if (get_value(expr, &sval) && sval.value != 0)
637 return 1;
638
639 return 0;
640 }
641
642 static int loop_num;
643 static char *get_loop_name(int num)
644 {
645 char buf[256];
646
647 snprintf(buf, 255, "-loop%d", num);
648 buf[255] = '\0';
649 return alloc_sname(buf);
650 }
651
652 /*
653 * Pre Loops are while and for loops.
654 */
655 static void handle_pre_loop(struct statement *stmt)
656 {
657 int once_through; /* we go through the loop at least once */
658 struct sm_state *extra_sm = NULL;
659 int unchanged = 0;
660 char *loop_name;
661 struct stree *stree = NULL;
662 struct sm_state *sm = NULL;
663
664 loop_name = get_loop_name(loop_num);
665 loop_num++;
666
667 __split_stmt(stmt->iterator_pre_statement);
668 __prev_stmt = stmt->iterator_pre_statement;
669
670 once_through = implied_condition_true(stmt->iterator_pre_condition);
671
672 loop_count++;
673 __push_continues();
674 __push_breaks();
675
676 __merge_gotos(loop_name, NULL);
677
678 extra_sm = __extra_handle_canonical_loops(stmt, &stree);
679 __in_pre_condition++;
680 __pass_to_client(stmt, PRELOOP_HOOK);
681 __split_whole_condition(stmt->iterator_pre_condition);
682 __in_pre_condition--;
683 FOR_EACH_SM(stree, sm) {
684 set_state(sm->owner, sm->name, sm->sym, sm->state);
685 } END_FOR_EACH_SM(sm);
686 free_stree(&stree);
687 if (extra_sm)
688 extra_sm = get_sm_state(extra_sm->owner, extra_sm->name, extra_sm->sym);
689
690 if (option_assume_loops)
691 once_through = 1;
692
693 __split_stmt(stmt->iterator_statement);
694 if (is_forever_loop(stmt)) {
695 __merge_continues();
696 __save_gotos(loop_name, NULL);
697
698 __push_fake_cur_stree();
699 __split_stmt(stmt->iterator_post_statement);
700 stree = __pop_fake_cur_stree();
701
702 __discard_false_states();
703 __use_breaks();
704
705 if (!__path_is_null())
706 __merge_stree_into_cur(stree);
707 free_stree(&stree);
708 } else {
709 __merge_continues();
710 unchanged = __iterator_unchanged(extra_sm);
711 __split_stmt(stmt->iterator_post_statement);
712 __prev_stmt = stmt->iterator_post_statement;
713 __cur_stmt = stmt;
714
715 __save_gotos(loop_name, NULL);
716 __in_pre_condition++;
717 __split_whole_condition(stmt->iterator_pre_condition);
718 __in_pre_condition--;
719 nullify_path();
720 __merge_false_states();
721 if (once_through)
722 __discard_false_states();
723 else
724 __merge_false_states();
725
726 if (extra_sm && unchanged)
727 __extra_pre_loop_hook_after(extra_sm,
728 stmt->iterator_post_statement,
729 stmt->iterator_pre_condition);
730 __merge_breaks();
731 }
732 loop_count--;
733 }
734
735 /*
736 * Post loops are do {} while();
737 */
738 static void handle_post_loop(struct statement *stmt)
739 {
740 char *loop_name;
741
742 loop_name = get_loop_name(loop_num);
743 loop_num++;
744 loop_count++;
745
746 __push_continues();
747 __push_breaks();
748 __merge_gotos(loop_name, NULL);
749 __split_stmt(stmt->iterator_statement);
750 __merge_continues();
751 if (!expr_is_zero(stmt->iterator_post_condition))
752 __save_gotos(loop_name, NULL);
753
754 if (is_forever_loop(stmt)) {
755 __use_breaks();
756 } else {
757 __split_whole_condition(stmt->iterator_post_condition);
758 __use_false_states();
759 __merge_breaks();
760 }
761 loop_count--;
762 }
763
764 static int empty_statement(struct statement *stmt)
765 {
766 if (!stmt)
767 return 0;
768 if (stmt->type == STMT_EXPRESSION && !stmt->expression)
769 return 1;
770 return 0;
771 }
772
773 static int last_stmt_on_same_line(void)
774 {
775 struct statement *stmt;
776 int i = 0;
777
778 FOR_EACH_PTR_REVERSE(big_statement_stack, stmt) {
779 if (!i++)
780 continue;
781 if (stmt->pos.line == get_lineno())
782 return 1;
783 return 0;
784 } END_FOR_EACH_PTR_REVERSE(stmt);
785 return 0;
786 }
787
788 static void split_asm_ops(struct asm_operand_list *ops)
789 {
790 struct asm_operand *op;
791
792 FOR_EACH_PTR(ops, op) {
793 __split_expr(op->expr);
794 } END_FOR_EACH_PTR(op);
795 }
796
797 static int is_case_val(struct statement *stmt, sval_t sval)
798 {
799 sval_t case_sval;
800
801 if (stmt->type != STMT_CASE)
802 return 0;
803 if (!stmt->case_expression) {
804 __set_default();
805 return 1;
806 }
807 if (!get_value(stmt->case_expression, &case_sval))
808 return 0;
809 if (case_sval.value == sval.value)
810 return 1;
811 return 0;
812 }
813
814 static struct range_list *get_case_rl(struct expression *switch_expr,
815 struct expression *case_expr,
816 struct expression *case_to)
817 {
818 sval_t start, end;
819 struct range_list *rl = NULL;
820 struct symbol *switch_type;
821
822 switch_type = get_type(switch_expr);
823 if (get_value(case_to, &end) && get_value(case_expr, &start)) {
824 start = sval_cast(switch_type, start);
825 end = sval_cast(switch_type, end);
826 add_range(&rl, start, end);
827 } else if (get_value(case_expr, &start)) {
828 start = sval_cast(switch_type, start);
829 add_range(&rl, start, start);
830 }
831
832 return rl;
833 }
834
835 static void split_known_switch(struct statement *stmt, sval_t sval)
836 {
837 struct statement *tmp;
838 struct range_list *rl;
839
840 __split_expr(stmt->switch_expression);
841 sval = sval_cast(get_type(stmt->switch_expression), sval);
842
843 push_expression(&switch_expr_stack, stmt->switch_expression);
844 __save_switch_states(top_expression(switch_expr_stack));
845 nullify_path();
846 __push_default();
847 __push_breaks();
848
849 stmt = stmt->switch_statement;
850
851 __push_scope_hooks();
852 FOR_EACH_PTR(stmt->stmts, tmp) {
853 __smatch_lineno = tmp->pos.line;
854 if (is_case_val(tmp, sval)) {
855 rl = alloc_rl(sval, sval);
856 __merge_switches(top_expression(switch_expr_stack), rl);
857 __pass_case_to_client(top_expression(switch_expr_stack), rl);
858 }
859 if (__path_is_null())
860 continue;
861 __split_stmt(tmp);
862 if (__path_is_null()) {
863 __set_default();
864 goto out;
865 }
866 } END_FOR_EACH_PTR(tmp);
867 out:
868 __call_scope_hooks();
869 if (!__pop_default())
870 __merge_switches(top_expression(switch_expr_stack), NULL);
871 __discard_switches();
872 __merge_breaks();
873 pop_expression(&switch_expr_stack);
874 }
875
876 static void split_case(struct statement *stmt)
877 {
878 struct range_list *rl = NULL;
879
880 expr_set_parent_stmt(stmt->case_expression, stmt);
881 expr_set_parent_stmt(stmt->case_to, stmt);
882
883 rl = get_case_rl(top_expression(switch_expr_stack),
884 stmt->case_expression, stmt->case_to);
885 while (stmt->case_statement->type == STMT_CASE) {
886 struct range_list *tmp;
887
888 tmp = get_case_rl(top_expression(switch_expr_stack),
889 stmt->case_statement->case_expression,
890 stmt->case_statement->case_to);
891 if (!tmp)
892 break;
893 rl = rl_union(rl, tmp);
894 if (!stmt->case_expression)
895 __set_default();
896 stmt = stmt->case_statement;
897 }
898
899 __merge_switches(top_expression(switch_expr_stack), rl);
900
901 if (!stmt->case_expression)
902 __set_default();
903 __split_stmt(stmt->case_statement);
904 }
905
906 int time_parsing_function(void)
907 {
908 return ms_since(&fn_start_time) / 1000;
909 }
910
911 bool taking_too_long(void)
912 {
913 if ((ms_since(&outer_fn_start_time) / 1000) > 60 * 5) /* five minutes */
914 return 1;
915 return 0;
916 }
917
918 int is_last_stmt(struct statement *cur_stmt)
919 {
920 struct symbol *fn;
921 struct statement *stmt;
922
923 if (!cur_func_sym)
924 return 0;
925 fn = get_base_type(cur_func_sym);
926 if (!fn)
927 return 0;
928 stmt = fn->stmt;
929 if (!stmt)
930 stmt = fn->inline_stmt;
931 if (!stmt || stmt->type != STMT_COMPOUND)
932 return 0;
933 stmt = last_ptr_list((struct ptr_list *)stmt->stmts);
934 if (stmt && stmt->type == STMT_LABEL)
935 stmt = stmt->label_statement;
936 if (stmt == cur_stmt)
937 return 1;
938 return 0;
939 }
940
941 static void handle_backward_goto(struct statement *goto_stmt)
942 {
943 const char *goto_name, *label_name;
944 struct statement *func_stmt;
945 struct symbol *base_type = get_base_type(cur_func_sym);
946 struct statement *tmp;
947 int found = 0;
948
949 if (!option_info)
950 return;
951 if (last_goto_statement_handled)
952 return;
953 last_goto_statement_handled = 1;
954
955 if (!goto_stmt->goto_label ||
956 goto_stmt->goto_label->type != SYM_LABEL ||
957 !goto_stmt->goto_label->ident)
958 return;
959 goto_name = goto_stmt->goto_label->ident->name;
960
961 func_stmt = base_type->stmt;
962 if (!func_stmt)
963 func_stmt = base_type->inline_stmt;
964 if (!func_stmt)
965 return;
966 if (func_stmt->type != STMT_COMPOUND)
967 return;
968
969 FOR_EACH_PTR(func_stmt->stmts, tmp) {
970 if (!found) {
971 if (tmp->type != STMT_LABEL)
972 continue;
973 if (!tmp->label_identifier ||
974 tmp->label_identifier->type != SYM_LABEL ||
975 !tmp->label_identifier->ident)
976 continue;
977 label_name = tmp->label_identifier->ident->name;
978 if (strcmp(goto_name, label_name) != 0)
979 continue;
980 found = 1;
981 }
982 __split_stmt(tmp);
983 } END_FOR_EACH_PTR(tmp);
984 }
985
986 static void fake_a_return(void)
987 {
988 struct symbol *return_type;
989
990 nullify_path();
991 __unnullify_path();
992
993 return_type = get_real_base_type(cur_func_sym);
994 return_type = get_real_base_type(return_type);
995 if (return_type != &void_ctype) {
996 __pass_to_client(unknown_value_expression(NULL), RETURN_HOOK);
997 nullify_path();
998 }
999 }
1000
1001 static void split_ret_value(struct expression *expr)
1002 {
1003 struct symbol *type;
1004
1005 if (!expr)
1006 return;
1007
1008 type = get_real_base_type(cur_func_sym);
1009 type = get_real_base_type(type);
1010 expr = fake_a_variable_assign(type, NULL, expr, -1);
1011
1012 __in_fake_var_assign++;
1013 __split_expr(expr);
1014 __in_fake_var_assign--;
1015 }
1016
1017 static void fake_an_empty_default(struct position pos)
1018 {
1019 static struct statement none = {};
1020
1021 none.pos = pos;
1022 none.type = STMT_NONE;
1023 __merge_switches(top_expression(switch_expr_stack), NULL);
1024 __split_stmt(&none);
1025 }
1026
1027 static void split_compound(struct statement *stmt)
1028 {
1029 struct statement *prev = NULL;
1030 struct statement *cur = NULL;
1031 struct statement *next;
1032
1033 __push_scope_hooks();
1034
1035 FOR_EACH_PTR(stmt->stmts, next) {
1036 /* just set them all ahead of time */
1037 stmt_set_parent_stmt(next, stmt);
1038
1039 if (cur) {
1040 __prev_stmt = prev;
1041 __next_stmt = next;
1042 __cur_stmt = cur;
1043 __split_stmt(cur);
1044 }
1045 prev = cur;
1046 cur = next;
1047 } END_FOR_EACH_PTR(next);
1048 if (cur) {
1049 __prev_stmt = prev;
1050 __cur_stmt = cur;
1051 __next_stmt = NULL;
1052 __split_stmt(cur);
1053 }
1054
1055 /*
1056 * For function scope, then delay calling the scope hooks until the
1057 * end of function hooks can run. I'm not positive this is the right
1058 * thing...
1059 */
1060 if (!is_last_stmt(cur))
1061 __call_scope_hooks();
1062 }
1063
1064 /*
1065 * This is a hack, work around for detecting empty functions.
1066 */
1067 static int need_delayed_scope_hooks(void)
1068 {
1069 struct symbol *fn = get_base_type(cur_func_sym);
1070 struct statement *stmt;
1071
1072 if (!fn)
1073 return 0;
1074 stmt = fn->stmt;
1075 if (!stmt)
1076 stmt = fn->inline_stmt;
1077 if (stmt && stmt->type == STMT_COMPOUND)
1078 return 1;
1079 return 0;
1080 }
1081
1082 void __split_label_stmt(struct statement *stmt)
1083 {
1084 if (stmt->label_identifier &&
1085 stmt->label_identifier->type == SYM_LABEL &&
1086 stmt->label_identifier->ident) {
1087 loop_count |= 0x0800000;
1088 __merge_gotos(stmt->label_identifier->ident->name, stmt->label_identifier);
1089 }
1090 }
1091
1092 static void find_asm_gotos(struct statement *stmt)
1093 {
1094 struct symbol *sym;
1095
1096 FOR_EACH_PTR(stmt->asm_labels, sym) {
1097 __save_gotos(sym->ident->name, sym);
1098 } END_FOR_EACH_PTR(sym);
1099 }
1100
1101 void __split_stmt(struct statement *stmt)
1102 {
1103 static int indent_cnt;
1104 sval_t sval;
1105
1106 if (!stmt)
1107 goto out;
1108
1109 if (!__in_fake_assign)
1110 __silence_warnings_for_stmt = false;
1111
1112 if (__bail_on_rest_of_function || is_skipped_function())
1113 return;
1114
1115 if (out_of_memory() || taking_too_long()) {
1116 struct timeval stop;
1117
1118 gettimeofday(&stop, NULL);
1119
1120 __bail_on_rest_of_function = 1;
1121 final_pass = 1;
1122 sm_perror("Function too hairy. Giving up. %lu seconds",
1123 stop.tv_sec - fn_start_time.tv_sec);
1124 fake_a_return();
1125 final_pass = 0; /* turn off sm_msg() from here */
1126 return;
1127 }
1128
1129 indent_cnt++;
1130
1131 add_ptr_list(&big_statement_stack, stmt);
1132 free_expression_stack(&big_expression_stack);
1133 set_position(stmt->pos);
1134 __pass_to_client(stmt, STMT_HOOK);
1135
1136 switch (stmt->type) {
1137 case STMT_DECLARATION:
1138 split_declaration(stmt->declaration);
1139 break;
1140 case STMT_RETURN:
1141 expr_set_parent_stmt(stmt->ret_value, stmt);
1142
1143 split_ret_value(stmt->ret_value);
1144 __pass_to_client(stmt->ret_value, RETURN_HOOK);
1145 __process_post_op_stack();
1146 nullify_path();
1147 break;
1148 case STMT_EXPRESSION:
1149 expr_set_parent_stmt(stmt->expression, stmt);
1150 expr_set_parent_stmt(stmt->context, stmt);
1151
1152 __split_expr(stmt->expression);
1153 break;
1154 case STMT_COMPOUND:
1155 split_compound(stmt);
1156 break;
1157 case STMT_IF:
1158 stmt_set_parent_stmt(stmt->if_true, stmt);
1159 stmt_set_parent_stmt(stmt->if_false, stmt);
1160 expr_set_parent_stmt(stmt->if_conditional, stmt);
1161
1162 if (known_condition_true(stmt->if_conditional)) {
1163 __split_stmt(stmt->if_true);
1164 break;
1165 }
1166 if (known_condition_false(stmt->if_conditional)) {
1167 __split_stmt(stmt->if_false);
1168 break;
1169 }
1170 __split_whole_condition(stmt->if_conditional);
1171 __split_stmt(stmt->if_true);
1172 if (empty_statement(stmt->if_true) &&
1173 last_stmt_on_same_line() &&
1174 !get_macro_name(stmt->if_true->pos))
1175 sm_warning("if();");
1176 __push_true_states();
1177 __use_false_states();
1178 __split_stmt(stmt->if_false);
1179 __merge_true_states();
1180 break;
1181 case STMT_ITERATOR:
1182 stmt_set_parent_stmt(stmt->iterator_pre_statement, stmt);
1183 stmt_set_parent_stmt(stmt->iterator_statement, stmt);
1184 stmt_set_parent_stmt(stmt->iterator_post_statement, stmt);
1185 expr_set_parent_stmt(stmt->iterator_pre_condition, stmt);
1186 expr_set_parent_stmt(stmt->iterator_post_condition, stmt);
1187
1188 if (stmt->iterator_pre_condition)
1189 handle_pre_loop(stmt);
1190 else if (stmt->iterator_post_condition)
1191 handle_post_loop(stmt);
1192 else {
1193 // these are for(;;) type loops.
1194 handle_pre_loop(stmt);
1195 }
1196 break;
1197 case STMT_SWITCH:
1198 stmt_set_parent_stmt(stmt->switch_statement, stmt);
1199 expr_set_parent_stmt(stmt->switch_expression, stmt);
1200
1201 if (get_value(stmt->switch_expression, &sval)) {
1202 split_known_switch(stmt, sval);
1203 break;
1204 }
1205 __split_expr(stmt->switch_expression);
1206 push_expression(&switch_expr_stack, stmt->switch_expression);
1207 __save_switch_states(top_expression(switch_expr_stack));
1208 nullify_path();
1209 __push_default();
1210 __push_breaks();
1211 __split_stmt(stmt->switch_statement);
1212 if (!__pop_default() && have_remaining_cases())
1213 fake_an_empty_default(stmt->pos);
1214 __discard_switches();
1215 __merge_breaks();
1216 pop_expression(&switch_expr_stack);
1217 break;
1218 case STMT_CASE:
1219 split_case(stmt);
1220 break;
1221 case STMT_LABEL:
1222 __split_label_stmt(stmt);
1223 __split_stmt(stmt->label_statement);
1224 break;
1225 case STMT_GOTO:
1226 expr_set_parent_stmt(stmt->goto_expression, stmt);
1227
1228 __split_expr(stmt->goto_expression);
1229 if (stmt->goto_label && stmt->goto_label->type == SYM_NODE) {
1230 if (!strcmp(stmt->goto_label->ident->name, "break")) {
1231 __process_breaks();
1232 } else if (!strcmp(stmt->goto_label->ident->name,
1233 "continue")) {
1234 __process_continues();
1235 }
1236 } else if (stmt->goto_label &&
1237 stmt->goto_label->type == SYM_LABEL &&
1238 stmt->goto_label->ident) {
1239 __save_gotos(stmt->goto_label->ident->name, stmt->goto_label);
1240 }
1241 nullify_path();
1242 if (is_last_stmt(stmt))
1243 handle_backward_goto(stmt);
1244 break;
1245 case STMT_NONE:
1246 break;
1247 case STMT_ASM:
1248 expr_set_parent_stmt(stmt->asm_string, stmt);
1249
1250 find_asm_gotos(stmt);
1251 __pass_to_client(stmt, ASM_HOOK);
1252 __split_expr(stmt->asm_string);
1253 split_asm_ops(stmt->asm_outputs);
1254 split_asm_ops(stmt->asm_inputs);
1255 split_expr_list(stmt->asm_clobbers, NULL);
1256 break;
1257 case STMT_CONTEXT:
1258 break;
1259 case STMT_RANGE:
1260 __split_expr(stmt->range_expression);
1261 __split_expr(stmt->range_low);
1262 __split_expr(stmt->range_high);
1263 break;
1264 }
1265 __pass_to_client(stmt, STMT_HOOK_AFTER);
1266 if (--indent_cnt == 1)
1267 __discard_fake_states(NULL);
1268
1269 out:
1270 __process_post_op_stack();
1271 }
1272
1273 static void split_expr_list(struct expression_list *expr_list, struct expression *parent)
1274 {
1275 struct expression *expr;
1276
1277 FOR_EACH_PTR(expr_list, expr) {
1278 expr_set_parent_expr(expr, parent);
1279 __split_expr(expr);
1280 __process_post_op_stack();
1281 } END_FOR_EACH_PTR(expr);
1282 }
1283
1284 static bool cast_arg(struct symbol *type, struct expression *arg)
1285 {
1286 struct symbol *orig;
1287
1288 if (!type)
1289 return false;
1290
1291 arg = strip_parens(arg);
1292 if (arg != strip_expr(arg))
1293 return true;
1294
1295 orig = get_type(arg);
1296 if (!orig)
1297 return true;
1298 if (orig == type)
1299 return false;
1300
1301 if (orig->type == SYM_ARRAY && type->type == SYM_PTR)
1302 return true;
1303
1304 /*
1305 * I would have expected that we could just do use (orig == type) but I
1306 * guess for pointers we need to get the basetype to do that comparison.
1307 *
1308 */
1309
1310 if (orig->type != SYM_PTR ||
1311 type->type != SYM_PTR) {
1312 if (type_fits(type, orig))
1313 return false;
1314 return true;
1315 }
1316 orig = get_real_base_type(orig);
1317 type = get_real_base_type(type);
1318 if (orig == type)
1319 return false;
1320
1321 return true;
1322 }
1323
1324 static struct expression *fake_a_variable_assign(struct symbol *type, struct expression *call, struct expression *expr, int nr)
1325 {
1326 struct expression *var, *assign, *parent;
1327 char buf[64];
1328 bool cast;
1329
1330 if (!expr)
1331 return NULL;
1332
1333 if (expr->type == EXPR_ASSIGNMENT)
1334 return expr;
1335
1336 cast = cast_arg(type, expr);
1337 /*
1338 * Using expr_to_sym() here is a hack. We want to say that we don't
1339 * need to assign frob(foo) or frob(foo->bar) if the types are right.
1340 * It turns out faking these assignments is way more expensive than I
1341 * would have imagined. I'm not sure why exactly.
1342 *
1343 */
1344 if (!cast) {
1345 /*
1346 * if the code is "return *p;" where "p" is a user pointer then
1347 * we want to create a fake assignment so that it sets the state
1348 * in check_kernel_user_data.c.
1349 *
1350 */
1351 if (expr->type != EXPR_PREOP &&
1352 expr->op != '*' && expr->op != '&' &&
1353 expr_to_sym(expr))
1354 return expr;
1355 }
1356
1357 if (nr == -1)
1358 snprintf(buf, sizeof(buf), "__sm_fake_%p", expr);
1359 else
1360 snprintf(buf, sizeof(buf), "__fake_param_%p_%d", call, nr);
1361 var = fake_variable(type, buf);
1362 assign = assign_expression(var, '=', expr);
1363 assign->smatch_flags |= Fake;
1364
1365 parent = expr_get_parent_expr(expr);
1366 expr_set_parent_expr(assign, parent);
1367 expr_set_parent_expr(expr, assign);
1368
1369 __fake_state_cnt++;
1370
1371 return assign;
1372 }
1373
1374 static void split_args(struct expression *expr)
1375 {
1376 struct expression *arg, *tmp;
1377 struct symbol *type;
1378 int i;
1379
1380 i = -1;
1381 FOR_EACH_PTR(expr->args, arg) {
1382 i++;
1383 expr_set_parent_expr(arg, expr);
1384 type = get_arg_type(expr->fn, i);
1385 tmp = fake_a_variable_assign(type, expr, arg, i);
1386 if (tmp != arg)
1387 __in_fake_var_assign++;
1388 __split_expr(tmp);
1389 if (tmp != arg)
1390 __in_fake_var_assign--;
1391 __process_post_op_stack();
1392 } END_FOR_EACH_PTR(arg);
1393 }
1394
1395 static void split_sym(struct symbol *sym)
1396 {
1397 if (!sym)
1398 return;
1399 if (!(sym->namespace & NS_SYMBOL))
1400 return;
1401
1402 __split_stmt(sym->stmt);
1403 __split_expr(sym->array_size);
1404 split_symlist(sym->arguments);
1405 split_symlist(sym->symbol_list);
1406 __split_stmt(sym->inline_stmt);
1407 split_symlist(sym->inline_symbol_list);
1408 }
1409
1410 static void split_symlist(struct symbol_list *sym_list)
1411 {
1412 struct symbol *sym;
1413
1414 FOR_EACH_PTR(sym_list, sym) {
1415 split_sym(sym);
1416 } END_FOR_EACH_PTR(sym);
1417 }
1418
1419 typedef void (fake_cb)(struct expression *expr);
1420
1421 static int member_to_number(struct expression *expr, struct ident *member)
1422 {
1423 struct symbol *type, *tmp;
1424 char *name;
1425 int i;
1426
1427 if (!member)
1428 return -1;
1429 name = member->name;
1430
1431 type = get_type(expr);
1432 if (!type || type->type != SYM_STRUCT)
1433 return -1;
1434
1435 i = -1;
1436 FOR_EACH_PTR(type->symbol_list, tmp) {
1437 i++;
1438 if (!tmp->ident)
1439 continue;
1440 if (strcmp(name, tmp->ident->name) == 0)
1441 return i;
1442 } END_FOR_EACH_PTR(tmp);
1443 return -1;
1444 }
1445
1446 static struct ident *number_to_member(struct expression *expr, int num)
1447 {
1448 struct symbol *type, *member;
1449 int i = 0;
1450
1451 type = get_type(expr);
1452 if (!type || type->type != SYM_STRUCT)
1453 return NULL;
1454
1455 FOR_EACH_PTR(type->symbol_list, member) {
1456 if (i == num)
1457 return member->ident;
1458 i++;
1459 } END_FOR_EACH_PTR(member);
1460 return NULL;
1461 }
1462
1463 static void fake_element_assigns_helper(struct expression *array, struct expression_list *expr_list, fake_cb *fake_cb);
1464
1465 static void set_inner_struct_members(struct expression *expr, struct symbol *member)
1466 {
1467 struct expression *edge_member, *assign;
1468 struct symbol *base = get_real_base_type(member);
1469 struct symbol *tmp;
1470
1471 if (member->ident)
1472 expr = member_expression(expr, '.', member->ident);
1473
1474 FOR_EACH_PTR(base->symbol_list, tmp) {
1475 struct symbol *type;
1476
1477 type = get_real_base_type(tmp);
1478 if (!type)
1479 continue;
1480
1481 edge_member = member_expression(expr, '.', tmp->ident);
1482 if (get_extra_state(edge_member))
1483 continue;
1484
1485 if (type->type == SYM_UNION || type->type == SYM_STRUCT) {
1486 set_inner_struct_members(expr, tmp);
1487 continue;
1488 }
1489
1490 if (!tmp->ident)
1491 continue;
1492
1493 assign = assign_expression(edge_member, '=', zero_expr());
1494 __split_expr(assign);
1495 } END_FOR_EACH_PTR(tmp);
1496
1497
1498 }
1499
1500 static void set_unset_to_zero(struct symbol *type, struct expression *expr)
1501 {
1502 struct symbol *tmp;
1503 struct expression *member = NULL;
1504 struct expression *assign;
1505 int op = '*';
1506
1507 if (expr->type == EXPR_PREOP && expr->op == '&') {
1508 expr = strip_expr(expr->unop);
1509 op = '.';
1510 }
1511
1512 FOR_EACH_PTR(type->symbol_list, tmp) {
1513 type = get_real_base_type(tmp);
1514 if (!type)
1515 continue;
1516
1517 if (tmp->ident) {
1518 member = member_expression(expr, op, tmp->ident);
1519 if (get_extra_state(member))
1520 continue;
1521 }
1522
1523 if (type->type == SYM_UNION || type->type == SYM_STRUCT) {
1524 set_inner_struct_members(expr, tmp);
1525 continue;
1526 }
1527 if (type->type == SYM_ARRAY)
1528 continue;
1529 if (!tmp->ident)
1530 continue;
1531
1532 assign = assign_expression(member, '=', zero_expr());
1533 __split_expr(assign);
1534 } END_FOR_EACH_PTR(tmp);
1535 }
1536
1537 static void fake_member_assigns_helper(struct expression *symbol, struct expression_list *members, fake_cb *fake_cb)
1538 {
1539 struct expression *deref, *assign, *tmp, *right;
1540 struct symbol *struct_type, *type;
1541 struct ident *member;
1542 int member_idx;
1543
1544 struct_type = get_type(symbol);
1545 if (!struct_type ||
1546 (struct_type->type != SYM_STRUCT && struct_type->type != SYM_UNION))
1547 return;
1548
1549 /*
1550 * We're parsing an initializer that could look something like this:
1551 * struct foo foo = {
1552 * 42,
1553 * .whatever.xxx = 11,
1554 * .zzz = 12,
1555 * };
1556 *
1557 * So what we have here is a list with 42, .whatever, and .zzz. We need
1558 * to break it up into left and right sides of the assignments.
1559 *
1560 */
1561 member_idx = 0;
1562 FOR_EACH_PTR(members, tmp) {
1563 deref = NULL;
1564 if (tmp->type == EXPR_IDENTIFIER) {
1565 member_idx = member_to_number(symbol, tmp->expr_ident);
1566 while (tmp->type == EXPR_IDENTIFIER) {
1567 member = tmp->expr_ident;
1568 tmp = tmp->ident_expression;
1569 if (deref)
1570 deref = member_expression(deref, '.', member);
1571 else
1572 deref = member_expression(symbol, '.', member);
1573 }
1574 } else {
1575 member = number_to_member(symbol, member_idx);
1576 deref = member_expression(symbol, '.', member);
1577 }
1578 right = tmp;
1579 member_idx++;
1580 if (right->type == EXPR_INITIALIZER) {
1581 type = get_type(deref);
1582 if (type && type->type == SYM_ARRAY)
1583 fake_element_assigns_helper(deref, right->expr_list, fake_cb);
1584 else
1585 fake_member_assigns_helper(deref, right->expr_list, fake_cb);
1586 } else {
1587 assign = assign_expression(deref, '=', right);
1588 fake_cb(assign);
1589 }
1590 } END_FOR_EACH_PTR(tmp);
1591
1592 set_unset_to_zero(struct_type, symbol);
1593 }
1594
1595 static void fake_member_assigns(struct symbol *sym, fake_cb *fake_cb)
1596 {
1597 fake_member_assigns_helper(symbol_expression(sym),
1598 sym->initializer->expr_list, fake_cb);
1599 }
1600
1601 static void fake_element_assigns_helper(struct expression *array, struct expression_list *expr_list, fake_cb *fake_cb)
1602 {
1603 struct expression *offset, *binop, *assign, *tmp;
1604 struct symbol *type;
1605 int idx;
1606
1607 if (ptr_list_size((struct ptr_list *)expr_list) > 1000)
1608 return;
1609
1610 idx = 0;
1611 FOR_EACH_PTR(expr_list, tmp) {
1612 if (tmp->type == EXPR_INDEX) {
1613 if (tmp->idx_from != tmp->idx_to)
1614 return;
1615 idx = tmp->idx_from;
1616 if (!tmp->idx_expression)
1617 goto next;
1618 tmp = tmp->idx_expression;
1619 }
1620 offset = value_expr(idx);
1621 binop = array_element_expression(array, offset);
1622 if (tmp->type == EXPR_INITIALIZER) {
1623 type = get_type(binop);
1624 if (type && type->type == SYM_ARRAY)
1625 fake_element_assigns_helper(binop, tmp->expr_list, fake_cb);
1626 else
1627 fake_member_assigns_helper(binop, tmp->expr_list, fake_cb);
1628 } else {
1629 assign = assign_expression(binop, '=', tmp);
1630 fake_cb(assign);
1631 }
1632 next:
1633 idx++;
1634 } END_FOR_EACH_PTR(tmp);
1635 }
1636
1637 static void fake_element_assigns(struct symbol *sym, fake_cb *fake_cb)
1638 {
1639 fake_element_assigns_helper(symbol_expression(sym), sym->initializer->expr_list, fake_cb);
1640 }
1641
1642 static void fake_assign_expr(struct symbol *sym)
1643 {
1644 struct expression *assign, *symbol;
1645
1646 symbol = symbol_expression(sym);
1647 assign = assign_expression(symbol, '=', sym->initializer);
1648 __split_expr(assign);
1649 }
1650
1651 static void do_initializer_stuff(struct symbol *sym)
1652 {
1653 if (!sym->initializer)
1654 return;
1655
1656 if (sym->initializer->type == EXPR_INITIALIZER) {
1657 if (get_real_base_type(sym)->type == SYM_ARRAY)
1658 fake_element_assigns(sym, __split_expr);
1659 else
1660 fake_member_assigns(sym, __split_expr);
1661 } else {
1662 fake_assign_expr(sym);
1663 }
1664 }
1665
1666 static void split_declaration(struct symbol_list *sym_list)
1667 {
1668 struct symbol *sym;
1669
1670 FOR_EACH_PTR(sym_list, sym) {
1671 __pass_to_client(sym, DECLARATION_HOOK);
1672 do_initializer_stuff(sym);
1673 split_sym(sym);
1674 } END_FOR_EACH_PTR(sym);
1675 }
1676
1677 static void call_global_assign_hooks(struct expression *assign)
1678 {
1679 __pass_to_client(assign, GLOBAL_ASSIGNMENT_HOOK);
1680 }
1681
1682 static void fake_global_assign(struct symbol *sym)
1683 {
1684 struct expression *assign, *symbol;
1685
1686 if (get_real_base_type(sym)->type == SYM_ARRAY) {
1687 if (sym->initializer && sym->initializer->type == EXPR_INITIALIZER) {
1688 fake_element_assigns(sym, call_global_assign_hooks);
1689 } else if (sym->initializer) {
1690 symbol = symbol_expression(sym);
1691 assign = assign_expression(symbol, '=', sym->initializer);
1692 __pass_to_client(assign, GLOBAL_ASSIGNMENT_HOOK);
1693 } else {
1694 fake_element_assigns_helper(symbol_expression(sym), NULL, call_global_assign_hooks);
1695 }
1696 } else if (get_real_base_type(sym)->type == SYM_STRUCT) {
1697 if (sym->initializer && sym->initializer->type == EXPR_INITIALIZER) {
1698 fake_member_assigns(sym, call_global_assign_hooks);
1699 } else if (sym->initializer) {
1700 symbol = symbol_expression(sym);
1701 assign = assign_expression(symbol, '=', sym->initializer);
1702 __pass_to_client(assign, GLOBAL_ASSIGNMENT_HOOK);
1703 } else {
1704 fake_member_assigns_helper(symbol_expression(sym), NULL, call_global_assign_hooks);
1705 }
1706 } else {
1707 symbol = symbol_expression(sym);
1708 if (sym->initializer) {
1709 assign = assign_expression(symbol, '=', sym->initializer);
1710 __split_expr(assign);
1711 } else {
1712 assign = assign_expression(symbol, '=', zero_expr());
1713 }
1714 __pass_to_client(assign, GLOBAL_ASSIGNMENT_HOOK);
1715 }
1716 }
1717
1718 static void start_function_definition(struct symbol *sym)
1719 {
1720 __in_function_def = 1;
1721 __pass_to_client(sym, FUNC_DEF_HOOK);
1722 __in_function_def = 0;
1723 __pass_to_client(sym, AFTER_DEF_HOOK);
1724
1725 }
1726
1727 void add_function_data(unsigned long *fn_data)
1728 {
1729 __add_ptr_list(&fn_data_list, fn_data);
1730 }
1731
1732 static void clear_function_data(void)
1733 {
1734 unsigned long *tmp;
1735
1736 FOR_EACH_PTR(fn_data_list, tmp) {
1737 *tmp = 0;
1738 } END_FOR_EACH_PTR(tmp);
1739 }
1740
1741 static void record_func_time(void)
1742 {
1743 struct timeval stop;
1744 int func_time;
1745 char buf[32];
1746
1747 gettimeofday(&stop, NULL);
1748 func_time = stop.tv_sec - fn_start_time.tv_sec;
1749 snprintf(buf, sizeof(buf), "%d", func_time);
1750 sql_insert_return_implies(FUNC_TIME, 0, "", buf);
1751 if (option_time && func_time > 2) {
1752 final_pass++;
1753 sm_msg("func_time: %d", func_time);
1754 final_pass--;
1755 }
1756 }
1757
1758 static void split_function(struct symbol *sym)
1759 {
1760 struct symbol *base_type = get_base_type(sym);
1761
1762 if (!base_type->stmt && !base_type->inline_stmt)
1763 return;
1764
1765 gettimeofday(&outer_fn_start_time, NULL);
1766 gettimeofday(&fn_start_time, NULL);
1767 cur_func_sym = sym;
1768 if (sym->ident)
1769 cur_func = sym->ident->name;
1770 set_position(sym->pos);
1771 clear_function_data();
1772 loop_count = 0;
1773 last_goto_statement_handled = 0;
1774 sm_debug("new function: %s\n", cur_func);
1775 __stree_id = 0;
1776 if (option_two_passes) {
1777 __unnullify_path();
1778 loop_num = 0;
1779 final_pass = 0;
1780 start_function_definition(sym);
1781 __split_stmt(base_type->stmt);
1782 __split_stmt(base_type->inline_stmt);
1783 nullify_path();
1784 }
1785 __unnullify_path();
1786 loop_num = 0;
1787 final_pass = 1;
1788 start_function_definition(sym);
1789 __split_stmt(base_type->stmt);
1790 __split_stmt(base_type->inline_stmt);
1791 __pass_to_client(sym, END_FUNC_HOOK);
1792 if (need_delayed_scope_hooks())
1793 __call_scope_hooks();
1794 __pass_to_client(sym, AFTER_FUNC_HOOK);
1795 sym->parsed = true;
1796
1797 clear_all_states();
1798
1799 record_func_time();
1800
1801 cur_func_sym = NULL;
1802 cur_func = NULL;
1803 free_data_info_allocs();
1804 free_expression_stack(&switch_expr_stack);
1805 __free_ptr_list((struct ptr_list **)&big_statement_stack);
1806 __bail_on_rest_of_function = 0;
1807 }
1808
1809 static void save_flow_state(void)
1810 {
1811 unsigned long *tmp;
1812
1813 __add_ptr_list(&backup, INT_PTR(loop_num << 2));
1814 __add_ptr_list(&backup, INT_PTR(loop_count << 2));
1815 __add_ptr_list(&backup, INT_PTR(final_pass << 2));
1816
1817 __add_ptr_list(&backup, big_statement_stack);
1818 __add_ptr_list(&backup, big_expression_stack);
1819 __add_ptr_list(&backup, big_condition_stack);
1820 __add_ptr_list(&backup, switch_expr_stack);
1821
1822 __add_ptr_list(&backup, cur_func_sym);
1823
1824 __add_ptr_list(&backup, __prev_stmt);
1825 __add_ptr_list(&backup, __cur_stmt);
1826 __add_ptr_list(&backup, __next_stmt);
1827
1828 FOR_EACH_PTR(fn_data_list, tmp) {
1829 __add_ptr_list(&backup, (void *)*tmp);
1830 } END_FOR_EACH_PTR(tmp);
1831 }
1832
1833 static void *pop_backup(void)
1834 {
1835 void *ret;
1836
1837 ret = last_ptr_list(backup);
1838 delete_ptr_list_last(&backup);
1839 return ret;
1840 }
1841
1842 static void restore_flow_state(void)
1843 {
1844 unsigned long *tmp;
1845
1846 FOR_EACH_PTR_REVERSE(fn_data_list, tmp) {
1847 *tmp = (unsigned long)pop_backup();
1848 } END_FOR_EACH_PTR_REVERSE(tmp);
1849
1850 __next_stmt = pop_backup();
1851 __cur_stmt = pop_backup();
1852 __prev_stmt = pop_backup();
1853
1854 cur_func_sym = pop_backup();
1855 switch_expr_stack = pop_backup();
1856 big_condition_stack = pop_backup();
1857 big_expression_stack = pop_backup();
1858 big_statement_stack = pop_backup();
1859 final_pass = PTR_INT(pop_backup()) >> 2;
1860 loop_count = PTR_INT(pop_backup()) >> 2;
1861 loop_num = PTR_INT(pop_backup()) >> 2;
1862 }
1863
1864 static void parse_inline(struct expression *call)
1865 {
1866 struct symbol *base_type;
1867 char *cur_func_bak = cur_func; /* not aligned correctly for backup */
1868 struct timeval time_backup = fn_start_time;
1869 struct expression *orig_inline = __inline_fn;
1870 int orig_budget;
1871
1872 if (out_of_memory() || taking_too_long())
1873 return;
1874
1875 save_flow_state();
1876
1877 __pass_to_client(call, INLINE_FN_START);
1878 final_pass = 0; /* don't print anything */
1879 __inline_fn = call;
1880 orig_budget = inline_budget;
1881 inline_budget = inline_budget - 5;
1882
1883 base_type = get_base_type(call->fn->symbol);
1884 cur_func_sym = call->fn->symbol;
1885 if (call->fn->symbol->ident)
1886 cur_func = call->fn->symbol->ident->name;
1887 else
1888 cur_func = NULL;
1889 set_position(call->fn->symbol->pos);
1890
1891 save_all_states();
1892 big_statement_stack = NULL;
1893 big_expression_stack = NULL;
1894 big_condition_stack = NULL;
1895 switch_expr_stack = NULL;
1896
1897 sm_debug("inline function: %s\n", cur_func);
1898 __unnullify_path();
1899 clear_function_data();
1900 loop_num = 0;
1901 loop_count = 0;
1902 start_function_definition(call->fn->symbol);
1903 __split_stmt(base_type->stmt);
1904 __split_stmt(base_type->inline_stmt);
1905 __pass_to_client(call->fn->symbol, END_FUNC_HOOK);
1906 __pass_to_client(call->fn->symbol, AFTER_FUNC_HOOK);
1907 call->fn->symbol->parsed = true;
1908
1909 free_expression_stack(&switch_expr_stack);
1910 __free_ptr_list((struct ptr_list **)&big_statement_stack);
1911 nullify_path();
1912 free_goto_stack();
1913
1914 restore_flow_state();
1915 fn_start_time = time_backup;
1916 cur_func = cur_func_bak;
1917
1918 restore_all_states();
1919 set_position(call->pos);
1920 __inline_fn = orig_inline;
1921 inline_budget = orig_budget;
1922 __pass_to_client(call, INLINE_FN_END);
1923 }
1924
1925 static struct symbol_list *inlines_called;
1926 static void add_inline_function(struct symbol *sym)
1927 {
1928 static struct symbol_list *already_added;
1929 struct symbol *tmp;
1930
1931 FOR_EACH_PTR(already_added, tmp) {
1932 if (tmp == sym)
1933 return;
1934 } END_FOR_EACH_PTR(tmp);
1935
1936 add_ptr_list(&already_added, sym);
1937 add_ptr_list(&inlines_called, sym);
1938 }
1939
1940 static void process_inlines(void)
1941 {
1942 struct symbol *tmp;
1943
1944 FOR_EACH_PTR(inlines_called, tmp) {
1945 split_function(tmp);
1946 } END_FOR_EACH_PTR(tmp);
1947 free_ptr_list(&inlines_called);
1948 }
1949
1950 static struct symbol *get_last_scoped_symbol(struct symbol_list *big_list, int use_static)
1951 {
1952 struct symbol *sym;
1953
1954 FOR_EACH_PTR_REVERSE(big_list, sym) {
1955 if (!sym->scope)
1956 continue;
1957 if (use_static && sym->ctype.modifiers & MOD_STATIC)
1958 return sym;
1959 if (!use_static && !(sym->ctype.modifiers & MOD_STATIC))
1960 return sym;
1961 } END_FOR_EACH_PTR_REVERSE(sym);
1962
1963 return NULL;
1964 }
1965
1966 static bool interesting_function(struct symbol *sym)
1967 {
1968 static int prev_stream = -1;
1969 static bool prev_answer;
1970 const char *filename;
1971 int len;
1972
1973 if (!(sym->ctype.modifiers & MOD_INLINE))
1974 return true;
1975
1976 if (sym->pos.stream == prev_stream)
1977 return prev_answer;
1978
1979 prev_stream = sym->pos.stream;
1980 prev_answer = false;
1981
1982 filename = stream_name(sym->pos.stream);
1983 len = strlen(filename);
1984 if (len > 0 && filename[len - 1] == 'c')
1985 prev_answer = true;
1986 return prev_answer;
1987 }
1988
1989 static void split_inlines_in_scope(struct symbol *sym)
1990 {
1991 struct symbol *base;
1992 struct symbol_list *scope_list;
1993 int stream;
1994
1995 scope_list = sym->scope->symbols;
1996 stream = sym->pos.stream;
1997
1998 /* find the last static symbol in the file */
1999 FOR_EACH_PTR_REVERSE(scope_list, sym) {
2000 if (sym->pos.stream != stream)
2001 continue;
2002 if (sym->type != SYM_NODE)
2003 continue;
2004 base = get_base_type(sym);
2005 if (!base)
2006 continue;
2007 if (base->type != SYM_FN)
2008 continue;
2009 if (!base->inline_stmt)
2010 continue;
2011 if (!interesting_function(sym))
2012 continue;
2013 add_inline_function(sym);
2014 } END_FOR_EACH_PTR_REVERSE(sym);
2015
2016 process_inlines();
2017 }
2018
2019 static void split_inlines(struct symbol_list *sym_list)
2020 {
2021 struct symbol *sym;
2022
2023 sym = get_last_scoped_symbol(sym_list, 0);
2024 if (sym)
2025 split_inlines_in_scope(sym);
2026 sym = get_last_scoped_symbol(sym_list, 1);
2027 if (sym)
2028 split_inlines_in_scope(sym);
2029 }
2030
2031 static struct stree *clone_estates_perm(struct stree *orig)
2032 {
2033 struct stree *ret = NULL;
2034 struct sm_state *tmp;
2035
2036 FOR_EACH_SM(orig, tmp) {
2037 set_state_stree_perm(&ret, tmp->owner, tmp->name, tmp->sym, clone_estate_perm(tmp->state));
2038 } END_FOR_EACH_SM(tmp);
2039
2040 return ret;
2041 }
2042
2043 struct position last_pos;
2044 static void split_c_file_functions(struct symbol_list *sym_list)
2045 {
2046 struct symbol *sym;
2047
2048 __unnullify_path();
2049 FOR_EACH_PTR(sym_list, sym) {
2050 set_position(sym->pos);
2051 if (sym->type != SYM_NODE || get_base_type(sym)->type != SYM_FN) {
2052 __pass_to_client(sym, BASE_HOOK);
2053 fake_global_assign(sym);
2054 }
2055 } END_FOR_EACH_PTR(sym);
2056 global_states = clone_estates_perm(get_all_states_stree(SMATCH_EXTRA));
2057 nullify_path();
2058
2059 FOR_EACH_PTR(sym_list, sym) {
2060 set_position(sym->pos);
2061 last_pos = sym->pos;
2062 if (!interesting_function(sym))
2063 continue;
2064 if (sym->type == SYM_NODE && get_base_type(sym)->type == SYM_FN) {
2065 split_function(sym);
2066 process_inlines();
2067 }
2068 last_pos = sym->pos;
2069 } END_FOR_EACH_PTR(sym);
2070 split_inlines(sym_list);
2071 __pass_to_client(sym_list, END_FILE_HOOK);
2072 }
2073
2074 static int final_before_fake;
2075 void init_fake_env(void)
2076 {
2077 if (!in_fake_env)
2078 final_before_fake = final_pass;
2079 in_fake_env++;
2080 __push_fake_cur_stree();
2081 final_pass = 0;
2082 }
2083
2084 void end_fake_env(void)
2085 {
2086 __pop_fake_cur_stree();
2087 in_fake_env--;
2088 if (!in_fake_env)
2089 final_pass = final_before_fake;
2090 }
2091
2092 static void open_output_files(char *base_file)
2093 {
2094 char buf[256];
2095
2096 snprintf(buf, sizeof(buf), "%s.smatch", base_file);
2097 sm_outfd = fopen(buf, "w");
2098 if (!sm_outfd)
2099 sm_fatal("Cannot open %s", buf);
2100
2101 if (!option_info)
2102 return;
2103
2104 snprintf(buf, sizeof(buf), "%s.smatch.sql", base_file);
2105 sql_outfd = fopen(buf, "w");
2106 if (!sql_outfd)
2107 sm_fatal("Error: Cannot open %s", buf);
2108
2109 snprintf(buf, sizeof(buf), "%s.smatch.caller_info", base_file);
2110 caller_info_fd = fopen(buf, "w");
2111 if (!caller_info_fd)
2112 sm_fatal("Error: Cannot open %s", buf);
2113 }
2114
2115 void smatch(struct string_list *filelist)
2116 {
2117 struct symbol_list *sym_list;
2118 struct timeval stop, start;
2119 char *path;
2120 int len;
2121
2122 gettimeofday(&start, NULL);
2123
2124 FOR_EACH_PTR_NOTAG(filelist, base_file) {
2125 path = getcwd(NULL, 0);
2126 free(full_base_file);
2127 if (path) {
2128 len = strlen(path) + 1 + strlen(base_file) + 1;
2129 full_base_file = malloc(len);
2130 snprintf(full_base_file, len, "%s/%s", path, base_file);
2131 } else {
2132 full_base_file = alloc_string(base_file);
2133 }
2134 if (option_file_output)
2135 open_output_files(base_file);
2136 sym_list = sparse_keep_tokens(base_file);
2137 split_c_file_functions(sym_list);
2138 } END_FOR_EACH_PTR_NOTAG(base_file);
2139
2140 gettimeofday(&stop, NULL);
2141
2142 set_position(last_pos);
2143 final_pass = 1;
2144 if (option_time)
2145 sm_msg("time: %lu", stop.tv_sec - start.tv_sec);
2146 if (option_mem)
2147 sm_msg("mem: %luKb", get_max_memory());
2148 }
Static analysis for C