xref: /illumos-gate/usr/src/tools/smatch/src/smatch_conditions.c (revision c85f09cc92abd00c84e58ec9f0f5d942906cb713)
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 /*
19  * The simplest type of condition is
20  * if (a) { ...
21  *
22  * The next simplest kind of conditions is
23  * if (a && b) { c;
24  * In that case 'a' is true when we get to 'b' and both are true
25  * when we get to c.
26  *
27  * Or's are a little more complicated.
28  * if (a || b) { c;
29  * We know 'a' is not true when we get to 'b' but it may be true
30  * when we get to c.
31  *
32  * If we mix and's and or's that's even more complicated.
33  * if (a && b && c || a && d) { d ;
34  * 'a' is true when we evaluate 'b', and 'd'.
35  * 'b' is true when we evaluate 'c' but otherwise we don't.
36  *
37  * The other thing that complicates matters is if we negate
38  * some if conditions.
39  * if (!a) { ...
40  * Smatch has passes the un-negated version to the client and flip
41  * the true and false values internally.  This makes it easier
42  * to write checks.
43  *
44  * And negations can be part of a compound.
45  * if (a && !(b || c)) { d;
46  * In that situation we multiply the negative through to simplify
47  * stuff so that we can remove the parens like this:
48  * if (a && !b && !c) { d;
49  *
50  * One other thing is that:
51  * if ((a) != 0){ ...
52  * that's basically the same as testing for just 'a' and we simplify
53  * comparisons with zero before passing it to the script.
54  *
55  */
56 
57 #include "smatch.h"
58 #include "smatch_slist.h"
59 #include "smatch_extra.h"
60 #include "smatch_expression_stacks.h"
61 
62 extern int __expr_stmt_count;
63 
64 struct expression_list *big_condition_stack;
65 
66 static void split_conditions(struct expression *expr);
67 
is_logical_and(struct expression * expr)68 static int is_logical_and(struct expression *expr)
69 {
70 	if (expr->op == SPECIAL_LOGICAL_AND)
71 		return 1;
72 	return 0;
73 }
74 
handle_zero_comparisons(struct expression * expr)75 static int handle_zero_comparisons(struct expression *expr)
76 {
77 	struct expression *tmp = NULL;
78 	struct expression *zero;
79 
80 	// if left is zero or right is zero
81 	if (expr_is_zero(expr->left)) {
82 		zero = strip_expr(expr->left);
83 		if (zero->type != EXPR_VALUE)
84 			__split_expr(expr->left);
85 		tmp = expr->right;
86 	} else if (expr_is_zero(expr->right)) {
87 		zero = strip_expr(expr->left);
88 		if (zero->type != EXPR_VALUE)
89 			__split_expr(expr->right);
90 		tmp = expr->left;
91 	} else {
92 		return 0;
93 	}
94 
95 	// "if (foo != 0)" is the same as "if (foo)"
96 	if (expr->op == SPECIAL_NOTEQUAL) {
97 		split_conditions(tmp);
98 		return 1;
99 	}
100 
101 	// "if (foo == 0)" is the same as "if (!foo)"
102 	if (expr->op == SPECIAL_EQUAL) {
103 		split_conditions(tmp);
104 		__negate_cond_stacks();
105 		return 1;
106 	}
107 
108 	return 0;
109 }
110 
111 /*
112  * This function is for handling calls to likely/unlikely
113  */
114 
ignore_builtin_expect(struct expression * expr)115 static int ignore_builtin_expect(struct expression *expr)
116 {
117 	if (sym_name_is("__builtin_expect", expr->fn)) {
118 		split_conditions(first_ptr_list((struct ptr_list *) expr->args));
119 		return 1;
120 	}
121 	return 0;
122 }
123 
124 /*
125  * handle_compound_stmt() is for: foo = ({blah; blah; blah; 1})
126  */
127 
handle_compound_stmt(struct statement * stmt)128 static void handle_compound_stmt(struct statement *stmt)
129 {
130 	struct expression *expr = NULL;
131 	struct statement *last;
132 	struct statement *s;
133 
134 	last = last_ptr_list((struct ptr_list *)stmt->stmts);
135 	if (last->type == STMT_LABEL) {
136 		if (last->label_statement &&
137 		    last->label_statement->type == STMT_EXPRESSION)
138 			expr = last->label_statement->expression;
139 		else
140 			last = NULL;
141 	} else if (last->type != STMT_EXPRESSION) {
142 		last = NULL;
143 	} else {
144 		expr = last->expression;
145 	}
146 
147 	FOR_EACH_PTR(stmt->stmts, s) {
148 		if (s != last)
149 			__split_stmt(s);
150 	} END_FOR_EACH_PTR(s);
151 	if (last && last->type == STMT_LABEL)
152 		__split_label_stmt(last);
153 	split_conditions(expr);
154 }
155 
handle_preop(struct expression * expr)156 static int handle_preop(struct expression *expr)
157 {
158 	struct statement *stmt;
159 
160 	if (expr->op == '!') {
161 		split_conditions(expr->unop);
162 		__negate_cond_stacks();
163 		return 1;
164 	}
165 	stmt = get_expression_statement(expr);
166 	if (stmt) {
167 		handle_compound_stmt(stmt);
168 		return 1;
169 	}
170 	return 0;
171 }
172 
handle_logical(struct expression * expr)173 static void handle_logical(struct expression *expr)
174 {
175 	/*
176 	 * If we come to an "and" expr then:
177 	 * We split the left side.
178 	 * We keep all the current states.
179 	 * We split the right side.
180 	 * We keep all the states from both true sides.
181 	 *
182 	 * If it's an "or" expr then:
183 	 * We save the current slist.
184 	 * We split the left side.
185 	 * We use the false states for the right side.
186 	 * We split the right side.
187 	 * We save all the states that are the same on both sides.
188 	 */
189 
190 	split_conditions(expr->left);
191 
192 	if (is_logical_and(expr))
193 		__use_cond_true_states();
194 	else
195 		__use_cond_false_states();
196 
197 	__push_cond_stacks();
198 
199 	__save_pre_cond_states();
200 	split_conditions(expr->right);
201 	__discard_pre_cond_states();
202 
203 	if (is_logical_and(expr))
204 		__and_cond_states();
205 	else
206 		__or_cond_states();
207 
208 	__use_cond_true_states();
209 }
210 
combine_strees(struct stree * orig,struct stree * fake,struct stree * new)211 static struct stree *combine_strees(struct stree *orig, struct stree *fake, struct stree *new)
212 {
213 	struct stree *ret = NULL;
214 
215 	overwrite_stree(orig, &ret);
216 	overwrite_stree(fake, &ret);
217 	overwrite_stree(new, &ret);
218 	free_stree(&new);
219 
220 	return ret;
221 }
222 
223 /*
224  * handle_select()
225  * if ((aaa()?bbb():ccc())) { ...
226  *
227  * This is almost the same as:
228  * if ((aaa() && bbb()) || (!aaa() && ccc())) { ...
229  *
230  * It's a bit complicated because we shouldn't pass aaa()
231  * to the clients more than once.
232  */
233 
handle_select(struct expression * expr)234 static void handle_select(struct expression *expr)
235 {
236 	struct stree *a_T = NULL;
237 	struct stree *a_F = NULL;
238 	struct stree *a_T_b_T = NULL;
239 	struct stree *a_T_b_F = NULL;
240 	struct stree *a_T_b_fake = NULL;
241 	struct stree *a_F_c_T = NULL;
242 	struct stree *a_F_c_F = NULL;
243 	struct stree *a_F_c_fake = NULL;
244 	struct stree *tmp;
245 	struct sm_state *sm;
246 
247 	/*
248 	 * Imagine we have this:  if (a ? b : c) { ...
249 	 *
250 	 * The condition is true if "a" is true and "b" is true or
251 	 * "a" is false and "c" is true.  It's false if "a" is true
252 	 * and "b" is false or "a" is false and "c" is false.
253 	 *
254 	 * The variable name "a_T_b_T" stands for "a true b true" etc.
255 	 *
256 	 * But if we know "b" is true then we can simpilify things.
257 	 * The condition is true if "a" is true or if "a" is false and
258 	 * "c" is true.  The only way the condition can be false is if
259 	 * "a" is false and "c" is false.
260 	 *
261 	 * The remaining thing is the "a_T_b_fake".  When we simplify
262 	 * the equations we have to take into consideration that other
263 	 * states may have changed that don't play into the true false
264 	 * equation.  Take the following example:
265 	 * if ({
266 	 *         (flags) = __raw_local_irq_save();
267 	 *         _spin_trylock(lock) ? 1 :
268 	 *                 ({ raw_local_irq_restore(flags);  0; });
269 	 *    })
270 	 * Smatch has to record that the irq flags were restored on the
271 	 * false path.
272 	 *
273 	 */
274 
275 	__save_pre_cond_states();
276 
277 	split_conditions(expr->conditional);
278 
279 	a_T = __copy_cond_true_states();
280 	a_F = __copy_cond_false_states();
281 
282 	__use_cond_true_states();
283 
284 	__push_cond_stacks();
285 	__push_fake_cur_stree();
286 	split_conditions(expr->cond_true);
287 	__process_post_op_stack();
288 	a_T_b_fake = __pop_fake_cur_stree();
289 	a_T_b_T = combine_strees(a_T, a_T_b_fake, __pop_cond_true_stack());
290 	a_T_b_F = combine_strees(a_T, a_T_b_fake, __pop_cond_false_stack());
291 
292 	__use_cond_false_states();
293 
294 	__push_cond_stacks();
295 	__push_fake_cur_stree();
296 	split_conditions(expr->cond_false);
297 	a_F_c_fake = __pop_fake_cur_stree();
298 	a_F_c_T = combine_strees(a_F, a_F_c_fake, __pop_cond_true_stack());
299 	a_F_c_F = combine_strees(a_F, a_F_c_fake, __pop_cond_false_stack());
300 
301 	/* We have to restore the pre condition states so that
302 	   implied_condition_true() will use the right cur_stree */
303 	__use_pre_cond_states();
304 
305 	if (implied_condition_true(expr->cond_true)) {
306 		free_stree(&a_T_b_T);
307 		free_stree(&a_T_b_F);
308 		a_T_b_T = clone_stree(a_T);
309 		overwrite_stree(a_T_b_fake, &a_T_b_T);
310 	}
311 	if (implied_condition_false(expr->cond_true)) {
312 		free_stree(&a_T_b_T);
313 		free_stree(&a_T_b_F);
314 		a_T_b_F = clone_stree(a_T);
315 		overwrite_stree(a_T_b_fake, &a_T_b_F);
316 	}
317 	if (implied_condition_true(expr->cond_false)) {
318 		free_stree(&a_F_c_T);
319 		free_stree(&a_F_c_F);
320 		a_F_c_T = clone_stree(a_F);
321 		overwrite_stree(a_F_c_fake, &a_F_c_T);
322 	}
323 	if (implied_condition_false(expr->cond_false)) {
324 		free_stree(&a_F_c_T);
325 		free_stree(&a_F_c_F);
326 		a_F_c_F = clone_stree(a_F);
327 		overwrite_stree(a_F_c_fake, &a_F_c_F);
328 	}
329 
330 	merge_stree(&a_T_b_T, a_F_c_T);
331 	merge_stree(&a_T_b_F, a_F_c_F);
332 
333 	tmp = __pop_cond_true_stack();
334 	free_stree(&tmp);
335 	tmp = __pop_cond_false_stack();
336 	free_stree(&tmp);
337 
338 	__push_cond_stacks();
339 	FOR_EACH_SM(a_T_b_T, sm) {
340 		__set_true_false_sm(sm, NULL);
341 	} END_FOR_EACH_SM(sm);
342 	FOR_EACH_SM(a_T_b_F, sm) {
343 		__set_true_false_sm(NULL, sm);
344 	} END_FOR_EACH_SM(sm);
345 	__free_set_states();
346 
347 	free_stree(&a_T_b_fake);
348 	free_stree(&a_F_c_fake);
349 	free_stree(&a_F_c_T);
350 	free_stree(&a_F_c_F);
351 	free_stree(&a_T_b_T);
352 	free_stree(&a_T_b_F);
353 	free_stree(&a_T);
354 	free_stree(&a_F);
355 }
356 
handle_comma(struct expression * expr)357 static void handle_comma(struct expression *expr)
358 {
359 	__split_expr(expr->left);
360 	split_conditions(expr->right);
361 }
362 
make_op_unsigned(int op)363 static int make_op_unsigned(int op)
364 {
365 	switch (op) {
366 	case '<':
367 		return SPECIAL_UNSIGNED_LT;
368 	case SPECIAL_LTE:
369 		return SPECIAL_UNSIGNED_LTE;
370 	case '>':
371 		return SPECIAL_UNSIGNED_GT;
372 	case SPECIAL_GTE:
373 		return SPECIAL_UNSIGNED_GTE;
374 	}
375 	return op;
376 }
377 
hackup_unsigned_compares(struct expression * expr)378 static void hackup_unsigned_compares(struct expression *expr)
379 {
380 	if (expr->type != EXPR_COMPARE)
381 		return;
382 
383 	if (type_unsigned(get_type(expr)))
384 		expr->op = make_op_unsigned(expr->op);
385 }
386 
do_condition(struct expression * expr)387 static void do_condition(struct expression *expr)
388 {
389 	__fold_in_set_states();
390 	__push_fake_cur_stree();
391 	__pass_to_client(expr, CONDITION_HOOK);
392 	__fold_in_set_states();
393 }
394 
split_conditions(struct expression * expr)395 static void split_conditions(struct expression *expr)
396 {
397 	if (option_debug) {
398 		char *cond = expr_to_str(expr);
399 
400 		sm_msg("%d in split_conditions (%s)", get_lineno(), cond);
401 		free_string(cond);
402 	}
403 
404 	expr = strip_expr_set_parent(expr);
405 	if (!expr) {
406 		__fold_in_set_states();
407 		return;
408 	}
409 
410 	/*
411 	 * On fast paths (and also I guess some people think it's cool) people
412 	 * sometimes use | instead of ||.  It works the same basically except
413 	 * that || implies a memory barrier between conditions.  The easiest way
414 	 * to handle it is by pretending that | also has a barrier and re-using
415 	 * all the normal condition code.  This potentially hides some bugs, but
416 	 * people who write code like this should just be careful or they
417 	 * deserve bugs.
418 	 *
419 	 * We could potentially treat boolean bitwise & this way but that seems
420 	 * too complicated to deal with.
421 	 */
422 	if (expr->type == EXPR_BINOP && expr->op == '|') {
423 		expr_set_parent_expr(expr->left, expr);
424 		expr_set_parent_expr(expr->right, expr);
425 		handle_logical(expr);
426 		return;
427 	}
428 
429 	switch (expr->type) {
430 	case EXPR_LOGICAL:
431 		expr_set_parent_expr(expr->left, expr);
432 		expr_set_parent_expr(expr->right, expr);
433 		__pass_to_client(expr, LOGIC_HOOK);
434 		handle_logical(expr);
435 		return;
436 	case EXPR_COMPARE:
437 		expr_set_parent_expr(expr->left, expr);
438 		expr_set_parent_expr(expr->right, expr);
439 		hackup_unsigned_compares(expr);
440 		if (handle_zero_comparisons(expr))
441 			return;
442 		break;
443 	case EXPR_CALL:
444 		if (ignore_builtin_expect(expr))
445 			return;
446 		break;
447 	case EXPR_PREOP:
448 		expr_set_parent_expr(expr->unop, expr);
449 		if (handle_preop(expr))
450 			return;
451 		break;
452 	case EXPR_CONDITIONAL:
453 	case EXPR_SELECT:
454 		expr_set_parent_expr(expr->conditional, expr);
455 		expr_set_parent_expr(expr->cond_true, expr);
456 		expr_set_parent_expr(expr->cond_false, expr);
457 		handle_select(expr);
458 		return;
459 	case EXPR_COMMA:
460 		expr_set_parent_expr(expr->left, expr);
461 		expr_set_parent_expr(expr->right, expr);
462 		handle_comma(expr);
463 		return;
464 	}
465 
466 	/* fixme: this should be in smatch_flow.c
467 	   but because of the funny stuff we do with conditions
468 	   it's awkward to put it there.  We would need to
469 	   call CONDITION_HOOK in smatch_flow as well.
470 	*/
471 	push_expression(&big_expression_stack, expr);
472 	push_expression(&big_condition_stack, expr);
473 
474 	if (expr->type == EXPR_COMPARE) {
475 		if (expr->left->type != EXPR_POSTOP)
476 			__split_expr(expr->left);
477 		if (expr->right->type != EXPR_POSTOP)
478 			__split_expr(expr->right);
479 	} else if (expr->type != EXPR_POSTOP) {
480 		__split_expr(expr);
481 	}
482 	do_condition(expr);
483 	if (expr->type == EXPR_COMPARE) {
484 		if (expr->left->type == EXPR_POSTOP)
485 			__split_expr(expr->left);
486 		if (expr->right->type == EXPR_POSTOP)
487 			__split_expr(expr->right);
488 	} else if (expr->type == EXPR_POSTOP) {
489 		__split_expr(expr);
490 	}
491 	__push_fake_cur_stree();
492 	__process_post_op_stack();
493 	__fold_in_set_states();
494 	pop_expression(&big_condition_stack);
495 	pop_expression(&big_expression_stack);
496 }
497 
498 static int inside_condition;
__split_whole_condition(struct expression * expr)499 void __split_whole_condition(struct expression *expr)
500 {
501 	sm_debug("%d in __split_whole_condition\n", get_lineno());
502 	inside_condition++;
503 	__save_pre_cond_states();
504 	__push_cond_stacks();
505 	/* it's a hack, but it's sometimes handy to have this stuff
506 	   on the big_expression_stack.  */
507 	push_expression(&big_expression_stack, expr);
508 	split_conditions(expr);
509 	__use_cond_states();
510 	__pass_to_client(expr, WHOLE_CONDITION_HOOK);
511 	pop_expression(&big_expression_stack);
512 	inside_condition--;
513 	sm_debug("%d done __split_whole_condition\n", get_lineno());
514 }
515 
__handle_logic(struct expression * expr)516 void __handle_logic(struct expression *expr)
517 {
518 	sm_debug("%d in __handle_logic\n", get_lineno());
519 	inside_condition++;
520 	__save_pre_cond_states();
521 	__push_cond_stacks();
522 	/* it's a hack, but it's sometimes handy to have this stuff
523 	   on the big_expression_stack.  */
524 	push_expression(&big_expression_stack, expr);
525 	if (expr)
526 		split_conditions(expr);
527 	__use_cond_states();
528 	__pass_to_client(expr, WHOLE_CONDITION_HOOK);
529 	pop_expression(&big_expression_stack);
530 	__merge_false_states();
531 	inside_condition--;
532 	sm_debug("%d done __handle_logic\n", get_lineno());
533 }
534 
is_condition(struct expression * expr)535 int is_condition(struct expression *expr)
536 {
537 
538 	expr = strip_expr(expr);
539 	if (!expr)
540 		return 0;
541 
542 	switch (expr->type) {
543 	case EXPR_LOGICAL:
544 	case EXPR_COMPARE:
545 		return 1;
546 	case EXPR_PREOP:
547 		if (expr->op == '!')
548 			return 1;
549 	}
550 	return 0;
551 }
552 
__handle_condition_assigns(struct expression * expr)553 int __handle_condition_assigns(struct expression *expr)
554 {
555 	struct expression *right;
556 	struct stree *true_stree, *false_stree, *fake_stree;
557 	struct sm_state *sm;
558 
559 	if (expr->op != '=')
560 		return 0;
561 	right = strip_expr(expr->right);
562 	if (!is_condition(expr->right))
563 		return 0;
564 
565 	sm_debug("%d in __handle_condition_assigns\n", get_lineno());
566 	inside_condition++;
567 	__save_pre_cond_states();
568 	__push_cond_stacks();
569 	/* it's a hack, but it's sometimes handy to have this stuff
570 	   on the big_expression_stack.  */
571 	push_expression(&big_expression_stack, right);
572 	split_conditions(right);
573 	true_stree = __get_true_states();
574 	false_stree = __get_false_states();
575 	__use_cond_states();
576 	__push_fake_cur_stree();
577 	set_extra_expr_mod(expr->left, alloc_estate_sval(sval_type_val(get_type(expr->left), 1)));
578 	__pass_to_client(right, WHOLE_CONDITION_HOOK);
579 
580 	fake_stree = __pop_fake_cur_stree();
581 	FOR_EACH_SM(fake_stree, sm) {
582 		overwrite_sm_state_stree(&true_stree, sm);
583 	} END_FOR_EACH_SM(sm);
584 	free_stree(&fake_stree);
585 
586 	pop_expression(&big_expression_stack);
587 	inside_condition--;
588 
589 	__push_true_states();
590 
591 	__use_false_states();
592 	__push_fake_cur_stree();
593 	set_extra_expr_mod(expr->left, alloc_estate_sval(sval_type_val(get_type(expr->left), 0)));
594 
595 	fake_stree = __pop_fake_cur_stree();
596 	FOR_EACH_SM(fake_stree, sm) {
597 		overwrite_sm_state_stree(&false_stree, sm);
598 	} END_FOR_EACH_SM(sm);
599 	free_stree(&fake_stree);
600 
601 	__merge_true_states();
602 	merge_fake_stree(&true_stree, false_stree);
603 	free_stree(&false_stree);
604 	FOR_EACH_SM(true_stree, sm) {
605 		__set_sm(sm);
606 	} END_FOR_EACH_SM(sm);
607 
608 	__pass_to_client(expr, ASSIGNMENT_HOOK);
609 	sm_debug("%d done __handle_condition_assigns\n", get_lineno());
610 	return 1;
611 }
612 
is_select_assign(struct expression * expr)613 static int is_select_assign(struct expression *expr)
614 {
615 	struct expression *right;
616 
617 	if (expr->op != '=')
618 		return 0;
619 	right = strip_expr(expr->right);
620 	if (right->type == EXPR_CONDITIONAL)
621 		return 1;
622 	if (right->type == EXPR_SELECT)
623 		return 1;
624 	return 0;
625 }
626 
__handle_select_assigns(struct expression * expr)627 int __handle_select_assigns(struct expression *expr)
628 {
629 	struct expression *right;
630 	struct stree *final_states = NULL;
631 	struct sm_state *sm;
632 	int is_true;
633 	int is_false;
634 
635 	if (!is_select_assign(expr))
636 		return 0;
637 	sm_debug("%d in __handle_ternary_assigns\n", get_lineno());
638 	right = strip_expr(expr->right);
639 	__pass_to_client(right, SELECT_HOOK);
640 
641 	is_true = implied_condition_true(right->conditional);
642 	is_false = implied_condition_false(right->conditional);
643 
644 	/* hah hah.  the ultra fake out */
645 	__save_pre_cond_states();
646 	__split_whole_condition(right->conditional);
647 
648 	if (!is_false) {
649 		struct expression *fake_expr;
650 
651 		if (right->cond_true)
652 			fake_expr = assign_expression(expr->left, expr->op, right->cond_true);
653 		else
654 			fake_expr = assign_expression(expr->left, expr->op, right->conditional);
655 		__split_expr(fake_expr);
656 		final_states = clone_stree(__get_cur_stree());
657 	}
658 
659 	__use_false_states();
660 	if (!is_true) {
661 		struct expression *fake_expr;
662 
663 		fake_expr = assign_expression(expr->left, expr->op, right->cond_false);
664 		__split_expr(fake_expr);
665 		merge_stree(&final_states, __get_cur_stree());
666 	}
667 
668 	__use_pre_cond_states();
669 
670 	FOR_EACH_SM(final_states, sm) {
671 		__set_sm(sm);
672 	} END_FOR_EACH_SM(sm);
673 
674 	free_stree(&final_states);
675 
676 	sm_debug("%d done __handle_ternary_assigns\n", get_lineno());
677 
678 	return 1;
679 }
680 
split_then_return_last(struct statement * stmt)681 static struct statement *split_then_return_last(struct statement *stmt)
682 {
683 	struct statement *tmp;
684 	struct statement *last_stmt;
685 
686 	last_stmt = last_ptr_list((struct ptr_list *)stmt->stmts);
687 	if (!last_stmt)
688 		return NULL;
689 
690 	__push_scope_hooks();
691 	FOR_EACH_PTR(stmt->stmts, tmp) {
692 		if (tmp == last_stmt) {
693 			if (tmp->type == STMT_LABEL) {
694 				__split_label_stmt(tmp);
695 				return tmp->label_statement;
696 			}
697 			return last_stmt;
698 		}
699 		__split_stmt(tmp);
700 	} END_FOR_EACH_PTR(tmp);
701 	return NULL;
702 }
703 
__handle_expr_statement_assigns(struct expression * expr)704 int __handle_expr_statement_assigns(struct expression *expr)
705 {
706 	struct expression *right;
707 	struct statement *stmt;
708 
709 	right = expr->right;
710 	if (right->type == EXPR_PREOP && right->op == '(')
711 		right = right->unop;
712 	if (right->type != EXPR_STATEMENT)
713 		return 0;
714 
715 	__expr_stmt_count++;
716 	stmt = right->statement;
717 	if (stmt->type == STMT_COMPOUND) {
718 		struct statement *last_stmt;
719 		struct expression *fake_assign;
720 		struct expression fake_expr_stmt = { .smatch_flags = Fake, };
721 
722 		last_stmt = split_then_return_last(stmt);
723 		if (!last_stmt) {
724 			__expr_stmt_count--;
725 			return 0;
726 		}
727 
728 		fake_expr_stmt.pos = last_stmt->pos;
729 		fake_expr_stmt.type = EXPR_STATEMENT;
730 		fake_expr_stmt.op = 0;
731 		fake_expr_stmt.statement = last_stmt;
732 
733 		fake_assign = assign_expression(expr->left, expr->op, &fake_expr_stmt);
734 		__split_expr(fake_assign);
735 
736 		__pass_to_client(stmt, STMT_HOOK_AFTER);
737 		__call_scope_hooks();
738 	} else if (stmt->type == STMT_EXPRESSION) {
739 		struct expression *fake_assign;
740 
741 		fake_assign = assign_expression(expr->left, expr->op, stmt->expression);
742 		__split_expr(fake_assign);
743 
744 	} else {
745 		__split_stmt(stmt);
746 	}
747 	__expr_stmt_count--;
748 	return 1;
749 }
750 
in_condition(void)751 int in_condition(void)
752 {
753 	return inside_condition;
754 }
755