xref: /illumos-gate/usr/src/tools/smatch/src/smatch_flow.c (revision 3dae5456c609a0bdfeffc8d1c0dc436db6ab3436)
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_env;
31 int final_pass;
32 int __inline_call;
33 struct expression  *__inline_fn;
34 
35 static int __smatch_lineno = 0;
36 
37 static char *base_file;
38 static const char *filename;
39 static char *pathname;
40 static char *full_filename;
41 static char *full_base_file;
42 static char *cur_func;
43 static unsigned int loop_count;
44 static int last_goto_statement_handled;
45 int __expr_stmt_count;
46 int __in_function_def;
47 static struct expression_list *switch_expr_stack = NULL;
48 static struct expression_list *post_op_stack = NULL;
49 
50 static struct ptr_list *backup;
51 
52 struct expression_list *big_expression_stack;
53 struct statement_list *big_statement_stack;
54 struct statement *__prev_stmt;
55 struct statement *__cur_stmt;
56 struct statement *__next_stmt;
57 int __in_pre_condition = 0;
58 int __bail_on_rest_of_function = 0;
59 static struct timeval fn_start_time;
60 static struct timeval outer_fn_start_time;
61 char *get_function(void) { return cur_func; }
62 int get_lineno(void) { return __smatch_lineno; }
63 int inside_loop(void) { return !!loop_count; }
64 int definitely_inside_loop(void) { return !!(loop_count & ~0x08000000); }
65 struct expression *get_switch_expr(void) { return top_expression(switch_expr_stack); }
66 int in_expression_statement(void) { return !!__expr_stmt_count; }
67 
68 static void split_symlist(struct symbol_list *sym_list);
69 static void split_declaration(struct symbol_list *sym_list);
70 static void split_expr_list(struct expression_list *expr_list, struct expression *parent);
71 static void add_inline_function(struct symbol *sym);
72 static void parse_inline(struct expression *expr);
73 
74 int option_assume_loops = 0;
75 int option_two_passes = 0;
76 struct symbol *cur_func_sym = NULL;
77 struct stree *global_states;
78 
79 const unsigned long valid_ptr_min = 4096;
80 unsigned long valid_ptr_max = ULONG_MAX & ~(MTAG_OFFSET_MASK);
81 const sval_t valid_ptr_min_sval = {
82 	.type = &ptr_ctype,
83 	{.value = 4096},
84 };
85 sval_t valid_ptr_max_sval = {
86 	.type = &ptr_ctype,
87 	{.value = ULONG_MAX & ~(MTAG_OFFSET_MASK)},
88 };
89 struct range_list *valid_ptr_rl;
90 
91 void alloc_valid_ptr_rl(void)
92 {
93 	valid_ptr_max = sval_type_max(&ulong_ctype).value & ~(MTAG_OFFSET_MASK);
94 	valid_ptr_max_sval.value = valid_ptr_max;
95 
96 	valid_ptr_rl = alloc_rl(valid_ptr_min_sval, valid_ptr_max_sval);
97 	valid_ptr_rl = cast_rl(&ptr_ctype, valid_ptr_rl);
98 	valid_ptr_rl = clone_rl_permanent(valid_ptr_rl);
99 }
100 
101 int outside_of_function(void)
102 {
103 	return cur_func_sym == NULL;
104 }
105 
106 const char *get_filename(void)
107 {
108 	if (option_info && option_full_path)
109 		return full_base_file;
110 	if (option_info)
111 		return base_file;
112 	if (option_full_path)
113 		return full_filename;
114 	return filename;
115 }
116 
117 const char *get_base_file(void)
118 {
119 	if (option_full_path)
120 		return full_base_file;
121 	return base_file;
122 }
123 
124 static void set_position(struct position pos)
125 {
126 	int len;
127 	static int prev_stream = -1;
128 
129 	if (in_fake_env)
130 		return;
131 
132 	if (pos.stream == 0 && pos.line == 0)
133 		return;
134 
135 	__smatch_lineno = pos.line;
136 
137 	if (pos.stream == prev_stream)
138 		return;
139 
140 	filename = stream_name(pos.stream);
141 
142 	free(full_filename);
143 	pathname = getcwd(NULL, 0);
144 	if (pathname) {
145 		len = strlen(pathname) + 1 + strlen(filename) + 1;
146 		full_filename = malloc(len);
147 		snprintf(full_filename, len, "%s/%s", pathname, filename);
148 	} else {
149 		full_filename = alloc_string(filename);
150 	}
151 	free(pathname);
152 }
153 
154 int is_assigned_call(struct expression *expr)
155 {
156 	struct expression *parent = expr_get_parent_expr(expr);
157 
158 	if (parent &&
159 	    parent->type == EXPR_ASSIGNMENT &&
160 	    parent->op == '=' &&
161 	    strip_expr(parent->right) == expr)
162 		return 1;
163 
164 	return 0;
165 }
166 
167 static int is_inline_func(struct expression *expr)
168 {
169 	if (expr->type != EXPR_SYMBOL || !expr->symbol)
170 		return 0;
171 	if (expr->symbol->ctype.modifiers & MOD_INLINE)
172 		return 1;
173 	return 0;
174 }
175 
176 static int is_noreturn_func(struct expression *expr)
177 {
178 	if (expr->type != EXPR_SYMBOL || !expr->symbol)
179 		return 0;
180 	if (expr->symbol->ctype.modifiers & MOD_NORETURN)
181 		return 1;
182 	return 0;
183 }
184 
185 static int inline_budget = 20;
186 
187 int inlinable(struct expression *expr)
188 {
189 	struct symbol *sym;
190 	struct statement *last_stmt = NULL;
191 
192 	if (__inline_fn)  /* don't nest */
193 		return 0;
194 
195 	if (expr->type != EXPR_SYMBOL || !expr->symbol)
196 		return 0;
197 	if (is_no_inline_function(expr->symbol->ident->name))
198 		return 0;
199 	sym = get_base_type(expr->symbol);
200 	if (sym->stmt && sym->stmt->type == STMT_COMPOUND) {
201 		if (ptr_list_size((struct ptr_list *)sym->stmt->stmts) > 10)
202 			return 0;
203 		if (sym->stmt->type != STMT_COMPOUND)
204 			return 0;
205 		last_stmt = last_ptr_list((struct ptr_list *)sym->stmt->stmts);
206 	}
207 	if (sym->inline_stmt && sym->inline_stmt->type == STMT_COMPOUND) {
208 		if (ptr_list_size((struct ptr_list *)sym->inline_stmt->stmts) > 10)
209 			return 0;
210 		if (sym->inline_stmt->type != STMT_COMPOUND)
211 			return 0;
212 		last_stmt = last_ptr_list((struct ptr_list *)sym->inline_stmt->stmts);
213 	}
214 
215 	if (!last_stmt)
216 		return 0;
217 
218 	/* the magic numbers in this function are pulled out of my bum. */
219 	if (last_stmt->pos.line > sym->pos.line + inline_budget)
220 		return 0;
221 
222 	return 1;
223 }
224 
225 void __process_post_op_stack(void)
226 {
227 	struct expression *expr;
228 
229 	FOR_EACH_PTR(post_op_stack, expr) {
230 		__pass_to_client(expr, OP_HOOK);
231 	} END_FOR_EACH_PTR(expr);
232 
233 	__free_ptr_list((struct ptr_list **)&post_op_stack);
234 }
235 
236 static int handle_comma_assigns(struct expression *expr)
237 {
238 	struct expression *right;
239 	struct expression *assign;
240 
241 	right = strip_expr(expr->right);
242 	if (right->type != EXPR_COMMA)
243 		return 0;
244 
245 	__split_expr(right->left);
246 	__process_post_op_stack();
247 
248 	assign = assign_expression(expr->left, '=', right->right);
249 	__split_expr(assign);
250 
251 	return 1;
252 }
253 
254 /* This is to handle *p++ = foo; assignments */
255 static int handle_postop_assigns(struct expression *expr)
256 {
257 	struct expression *left, *fake_left;
258 	struct expression *assign;
259 
260 	left = strip_expr(expr->left);
261 	if (left->type != EXPR_PREOP || left->op != '*')
262 		return 0;
263 	left = strip_expr(left->unop);
264 	if (left->type != EXPR_POSTOP)
265 		return 0;
266 
267 	fake_left = deref_expression(strip_expr(left->unop));
268 	assign = assign_expression(fake_left, '=', expr->right);
269 
270 	__split_expr(assign);
271 	__split_expr(expr->left);
272 
273 	return 1;
274 }
275 
276 static int prev_expression_is_getting_address(struct expression *expr)
277 {
278 	struct expression *parent;
279 
280 	do {
281 		parent = expr_get_parent_expr(expr);
282 
283 		if (!parent)
284 			return 0;
285 		if (parent->type == EXPR_PREOP && parent->op == '&')
286 			return 1;
287 		if (parent->type == EXPR_PREOP && parent->op == '(')
288 			goto next;
289 		if (parent->type == EXPR_DEREF && parent->op == '.')
290 			goto next;
291 
292 		return 0;
293 next:
294 		expr = parent;
295 	} while (1);
296 }
297 
298 static void handle_builtin_overflow_func(struct expression *expr)
299 {
300 	struct expression *a, *b, *res, *assign;
301 	int op;
302 
303 	if (sym_name_is("__builtin_add_overflow", expr->fn))
304 		op = '+';
305 	else if (sym_name_is("__builtin_sub_overflow", expr->fn))
306 		op = '-';
307 	else if (sym_name_is("__builtin_mul_overflow", expr->fn))
308 		op = '*';
309 	else
310 		return;
311 
312 	a = get_argument_from_call_expr(expr->args, 0);
313 	b = get_argument_from_call_expr(expr->args, 1);
314 	res = get_argument_from_call_expr(expr->args, 2);
315 
316 	assign = assign_expression(deref_expression(res), '=', binop_expression(a, op, b));
317 	__split_expr(assign);
318 }
319 
320 static int handle__builtin_choose_expr(struct expression *expr)
321 {
322 	struct expression *const_expr, *expr1, *expr2;
323 	sval_t sval;
324 
325 	if (!sym_name_is("__builtin_choose_expr", expr->fn))
326 		return 0;
327 
328 	const_expr = get_argument_from_call_expr(expr->args, 0);
329 	expr1 = get_argument_from_call_expr(expr->args, 1);
330 	expr2 = get_argument_from_call_expr(expr->args, 2);
331 
332 	if (!get_value(const_expr, &sval) || !expr1 || !expr2)
333 		return 0;
334 	if (sval.value)
335 		__split_expr(expr1);
336 	else
337 		__split_expr(expr2);
338 	return 1;
339 }
340 
341 static int handle__builtin_choose_expr_assigns(struct expression *expr)
342 {
343 	struct expression *const_expr, *right, *expr1, *expr2, *fake;
344 	sval_t sval;
345 
346 	right = strip_expr(expr->right);
347 	if (right->type != EXPR_CALL)
348 		return 0;
349 	if (!sym_name_is("__builtin_choose_expr", right->fn))
350 		return 0;
351 
352 	const_expr = get_argument_from_call_expr(right->args, 0);
353 	expr1 = get_argument_from_call_expr(right->args, 1);
354 	expr2 = get_argument_from_call_expr(right->args, 2);
355 
356 	if (!get_value(const_expr, &sval) || !expr1 || !expr2)
357 		return 0;
358 
359 	fake = assign_expression(expr->left, '=', sval.value ? expr1 : expr2);
360 	__split_expr(fake);
361 	return 1;
362 }
363 
364 void __split_expr(struct expression *expr)
365 {
366 	if (!expr)
367 		return;
368 
369 	// sm_msg(" Debug expr_type %d %s", expr->type, show_special(expr->op));
370 
371 	if (__in_fake_assign && expr->type != EXPR_ASSIGNMENT)
372 		return;
373 	if (__in_fake_assign >= 4)  /* don't allow too much nesting */
374 		return;
375 
376 	push_expression(&big_expression_stack, expr);
377 	set_position(expr->pos);
378 	__pass_to_client(expr, EXPR_HOOK);
379 
380 	switch (expr->type) {
381 	case EXPR_PREOP:
382 		expr_set_parent_expr(expr->unop, expr);
383 
384 		if (expr->op == '*' &&
385 		    !prev_expression_is_getting_address(expr))
386 			__pass_to_client(expr, DEREF_HOOK);
387 		__split_expr(expr->unop);
388 		__pass_to_client(expr, OP_HOOK);
389 		break;
390 	case EXPR_POSTOP:
391 		expr_set_parent_expr(expr->unop, expr);
392 
393 		__split_expr(expr->unop);
394 		push_expression(&post_op_stack, expr);
395 		break;
396 	case EXPR_STATEMENT:
397 		__expr_stmt_count++;
398 		if (expr->statement && !expr->statement) {
399 			stmt_set_parent_stmt(expr->statement,
400 					last_ptr_list((struct ptr_list *)big_statement_stack));
401 		}
402 		__split_stmt(expr->statement);
403 		__expr_stmt_count--;
404 		break;
405 	case EXPR_LOGICAL:
406 	case EXPR_COMPARE:
407 		expr_set_parent_expr(expr->left, expr);
408 		expr_set_parent_expr(expr->right, expr);
409 
410 		__pass_to_client(expr, LOGIC_HOOK);
411 		__handle_logic(expr);
412 		break;
413 	case EXPR_BINOP:
414 		expr_set_parent_expr(expr->left, expr);
415 		expr_set_parent_expr(expr->right, expr);
416 
417 		__pass_to_client(expr, BINOP_HOOK);
418 	case EXPR_COMMA:
419 		expr_set_parent_expr(expr->left, expr);
420 		expr_set_parent_expr(expr->right, expr);
421 
422 		__split_expr(expr->left);
423 		__process_post_op_stack();
424 		__split_expr(expr->right);
425 		break;
426 	case EXPR_ASSIGNMENT: {
427 		struct expression *right;
428 
429 		expr_set_parent_expr(expr->left, expr);
430 		expr_set_parent_expr(expr->right, expr);
431 
432 		right = strip_expr(expr->right);
433 		if (!right)
434 			break;
435 
436 		__pass_to_client(expr, RAW_ASSIGNMENT_HOOK);
437 
438 		/* foo = !bar() */
439 		if (__handle_condition_assigns(expr))
440 			break;
441 		/* foo = (x < 5 ? foo : 5); */
442 		if (__handle_select_assigns(expr))
443 			break;
444 		/* foo = ({frob(); frob(); frob(); 1;}) */
445 		if (__handle_expr_statement_assigns(expr))
446 			break;
447 		/* foo = (3, 4); */
448 		if (handle_comma_assigns(expr))
449 			break;
450 		if (handle_postop_assigns(expr))
451 			break;
452 		if (handle__builtin_choose_expr_assigns(expr))
453 			break;
454 
455 		__split_expr(expr->right);
456 		if (outside_of_function())
457 			__pass_to_client(expr, GLOBAL_ASSIGNMENT_HOOK);
458 		else
459 			__pass_to_client(expr, ASSIGNMENT_HOOK);
460 
461 		__fake_struct_member_assignments(expr);
462 
463 		if (expr->op == '=' && right->type == EXPR_CALL)
464 			__pass_to_client(expr, CALL_ASSIGNMENT_HOOK);
465 
466 		if (get_macro_name(right->pos) &&
467 		    get_macro_name(expr->pos) != get_macro_name(right->pos))
468 			__pass_to_client(expr, MACRO_ASSIGNMENT_HOOK);
469 
470 		__pass_to_client(expr, ASSIGNMENT_HOOK_AFTER);
471 
472 		__split_expr(expr->left);
473 		break;
474 	}
475 	case EXPR_DEREF:
476 		expr_set_parent_expr(expr->deref, expr);
477 
478 		__pass_to_client(expr, DEREF_HOOK);
479 		__split_expr(expr->deref);
480 		break;
481 	case EXPR_SLICE:
482 		expr_set_parent_expr(expr->base, expr);
483 
484 		__split_expr(expr->base);
485 		break;
486 	case EXPR_CAST:
487 	case EXPR_FORCE_CAST:
488 		expr_set_parent_expr(expr->cast_expression, expr);
489 
490 		__pass_to_client(expr, CAST_HOOK);
491 		__split_expr(expr->cast_expression);
492 		break;
493 	case EXPR_SIZEOF:
494 		if (expr->cast_expression)
495 			__pass_to_client(strip_parens(expr->cast_expression),
496 					 SIZEOF_HOOK);
497 		break;
498 	case EXPR_OFFSETOF:
499 	case EXPR_ALIGNOF:
500 		break;
501 	case EXPR_CONDITIONAL:
502 	case EXPR_SELECT:
503 		expr_set_parent_expr(expr->conditional, expr);
504 		expr_set_parent_expr(expr->cond_true, expr);
505 		expr_set_parent_expr(expr->cond_false, expr);
506 
507 		if (known_condition_true(expr->conditional)) {
508 			__split_expr(expr->cond_true);
509 			break;
510 		}
511 		if (known_condition_false(expr->conditional)) {
512 			__split_expr(expr->cond_false);
513 			break;
514 		}
515 		__pass_to_client(expr, SELECT_HOOK);
516 		__split_whole_condition(expr->conditional);
517 		__split_expr(expr->cond_true);
518 		__push_true_states();
519 		__use_false_states();
520 		__split_expr(expr->cond_false);
521 		__merge_true_states();
522 		break;
523 	case EXPR_CALL:
524 		expr_set_parent_expr(expr->fn, expr);
525 
526 		if (sym_name_is("__builtin_constant_p", expr->fn))
527 			break;
528 		if (handle__builtin_choose_expr(expr))
529 			break;
530 		split_expr_list(expr->args, expr);
531 		__split_expr(expr->fn);
532 		if (is_inline_func(expr->fn))
533 			add_inline_function(expr->fn->symbol);
534 		if (inlinable(expr->fn))
535 			__inline_call = 1;
536 		__process_post_op_stack();
537 		__pass_to_client(expr, FUNCTION_CALL_HOOK_BEFORE);
538 		__pass_to_client(expr, FUNCTION_CALL_HOOK);
539 		__inline_call = 0;
540 		if (inlinable(expr->fn)) {
541 			parse_inline(expr);
542 		}
543 		__pass_to_client(expr, CALL_HOOK_AFTER_INLINE);
544 		if (is_noreturn_func(expr->fn))
545 			nullify_path();
546 		handle_builtin_overflow_func(expr);
547 		break;
548 	case EXPR_INITIALIZER:
549 		split_expr_list(expr->expr_list, expr);
550 		break;
551 	case EXPR_IDENTIFIER:
552 		expr_set_parent_expr(expr->ident_expression, expr);
553 		__split_expr(expr->ident_expression);
554 		break;
555 	case EXPR_INDEX:
556 		expr_set_parent_expr(expr->idx_expression, expr);
557 		__split_expr(expr->idx_expression);
558 		break;
559 	case EXPR_POS:
560 		expr_set_parent_expr(expr->init_expr, expr);
561 		__split_expr(expr->init_expr);
562 		break;
563 	case EXPR_SYMBOL:
564 		__pass_to_client(expr, SYM_HOOK);
565 		break;
566 	case EXPR_STRING:
567 		__pass_to_client(expr, STRING_HOOK);
568 		break;
569 	default:
570 		break;
571 	};
572 	pop_expression(&big_expression_stack);
573 }
574 
575 static int is_forever_loop(struct statement *stmt)
576 {
577 	struct expression *expr;
578 	sval_t sval;
579 
580 	expr = strip_expr(stmt->iterator_pre_condition);
581 	if (!expr)
582 		expr = stmt->iterator_post_condition;
583 	if (!expr) {
584 		/* this is a for(;;) loop... */
585 		return 1;
586 	}
587 
588 	if (get_value(expr, &sval) && sval.value != 0)
589 		return 1;
590 
591 	return 0;
592 }
593 
594 static int loop_num;
595 static char *get_loop_name(int num)
596 {
597 	char buf[256];
598 
599 	snprintf(buf, 255, "-loop%d", num);
600 	buf[255] = '\0';
601 	return alloc_sname(buf);
602 }
603 
604 /*
605  * Pre Loops are while and for loops.
606  */
607 static void handle_pre_loop(struct statement *stmt)
608 {
609 	int once_through; /* we go through the loop at least once */
610 	struct sm_state *extra_sm = NULL;
611 	int unchanged = 0;
612 	char *loop_name;
613 	struct stree *stree = NULL;
614 	struct sm_state *sm = NULL;
615 
616 	loop_name = get_loop_name(loop_num);
617 	loop_num++;
618 
619 	__split_stmt(stmt->iterator_pre_statement);
620 	__prev_stmt = stmt->iterator_pre_statement;
621 
622 	once_through = implied_condition_true(stmt->iterator_pre_condition);
623 
624 	loop_count++;
625 	__push_continues();
626 	__push_breaks();
627 
628 	__merge_gotos(loop_name, NULL);
629 
630 	extra_sm = __extra_handle_canonical_loops(stmt, &stree);
631 	__in_pre_condition++;
632 	__pass_to_client(stmt, PRELOOP_HOOK);
633 	__split_whole_condition(stmt->iterator_pre_condition);
634 	__in_pre_condition--;
635 	FOR_EACH_SM(stree, sm) {
636 		set_state(sm->owner, sm->name, sm->sym, sm->state);
637 	} END_FOR_EACH_SM(sm);
638 	free_stree(&stree);
639 	if (extra_sm)
640 		extra_sm = get_sm_state(extra_sm->owner, extra_sm->name, extra_sm->sym);
641 
642 	if (option_assume_loops)
643 		once_through = 1;
644 
645 	__split_stmt(stmt->iterator_statement);
646 	if (is_forever_loop(stmt)) {
647 		__merge_continues();
648 		__save_gotos(loop_name, NULL);
649 
650 		__push_fake_cur_stree();
651 		__split_stmt(stmt->iterator_post_statement);
652 		stree = __pop_fake_cur_stree();
653 
654 		__discard_false_states();
655 		__use_breaks();
656 
657 		if (!__path_is_null())
658 			__merge_stree_into_cur(stree);
659 		free_stree(&stree);
660 	} else {
661 		__merge_continues();
662 		unchanged = __iterator_unchanged(extra_sm);
663 		__split_stmt(stmt->iterator_post_statement);
664 		__prev_stmt = stmt->iterator_post_statement;
665 		__cur_stmt = stmt;
666 
667 		__save_gotos(loop_name, NULL);
668 		__in_pre_condition++;
669 		__split_whole_condition(stmt->iterator_pre_condition);
670 		__in_pre_condition--;
671 		nullify_path();
672 		__merge_false_states();
673 		if (once_through)
674 			__discard_false_states();
675 		else
676 			__merge_false_states();
677 
678 		if (extra_sm && unchanged)
679 			__extra_pre_loop_hook_after(extra_sm,
680 						stmt->iterator_post_statement,
681 						stmt->iterator_pre_condition);
682 		__merge_breaks();
683 	}
684 	loop_count--;
685 }
686 
687 /*
688  * Post loops are do {} while();
689  */
690 static void handle_post_loop(struct statement *stmt)
691 {
692 	char *loop_name;
693 
694 	loop_name = get_loop_name(loop_num);
695 	loop_num++;
696 	loop_count++;
697 
698 	__push_continues();
699 	__push_breaks();
700 	__merge_gotos(loop_name, NULL);
701 	__split_stmt(stmt->iterator_statement);
702 	__merge_continues();
703 	if (!is_zero(stmt->iterator_post_condition))
704 		__save_gotos(loop_name, NULL);
705 
706 	if (is_forever_loop(stmt)) {
707 		__use_breaks();
708 	} else {
709 		__split_whole_condition(stmt->iterator_post_condition);
710 		__use_false_states();
711 		__merge_breaks();
712 	}
713 	loop_count--;
714 }
715 
716 static int empty_statement(struct statement *stmt)
717 {
718 	if (!stmt)
719 		return 0;
720 	if (stmt->type == STMT_EXPRESSION && !stmt->expression)
721 		return 1;
722 	return 0;
723 }
724 
725 static int last_stmt_on_same_line(void)
726 {
727 	struct statement *stmt;
728 	int i = 0;
729 
730 	FOR_EACH_PTR_REVERSE(big_statement_stack, stmt) {
731 		if (!i++)
732 			continue;
733 		if  (stmt->pos.line == get_lineno())
734 			return 1;
735 		return 0;
736 	} END_FOR_EACH_PTR_REVERSE(stmt);
737 	return 0;
738 }
739 
740 static void split_asm_constraints(struct expression_list *expr_list)
741 {
742 	struct expression *expr;
743 	int state = 0;
744 
745 	FOR_EACH_PTR(expr_list, expr) {
746 		switch (state) {
747 		case 0: /* identifier */
748 		case 1: /* constraint */
749 			state++;
750 			continue;
751 		case 2: /* expression */
752 			state = 0;
753 			__split_expr(expr);
754 			continue;
755 		}
756 	} END_FOR_EACH_PTR(expr);
757 }
758 
759 static int is_case_val(struct statement *stmt, sval_t sval)
760 {
761 	sval_t case_sval;
762 
763 	if (stmt->type != STMT_CASE)
764 		return 0;
765 	if (!stmt->case_expression) {
766 		__set_default();
767 		return 1;
768 	}
769 	if (!get_value(stmt->case_expression, &case_sval))
770 		return 0;
771 	if (case_sval.value == sval.value)
772 		return 1;
773 	return 0;
774 }
775 
776 static struct range_list *get_case_rl(struct expression *switch_expr,
777 				      struct expression *case_expr,
778 				      struct expression *case_to)
779 {
780 	sval_t start, end;
781 	struct range_list *rl = NULL;
782 	struct symbol *switch_type;
783 
784 	switch_type = get_type(switch_expr);
785 	if (get_value(case_to, &end) && get_value(case_expr, &start)) {
786 		start = sval_cast(switch_type, start);
787 		end = sval_cast(switch_type, end);
788 		add_range(&rl, start, end);
789 	} else if (get_value(case_expr, &start)) {
790 		start = sval_cast(switch_type, start);
791 		add_range(&rl, start, start);
792 	}
793 
794 	return rl;
795 }
796 
797 static void split_known_switch(struct statement *stmt, sval_t sval)
798 {
799 	struct statement *tmp;
800 	struct range_list *rl;
801 
802 	__split_expr(stmt->switch_expression);
803 	sval = sval_cast(get_type(stmt->switch_expression), sval);
804 
805 	push_expression(&switch_expr_stack, stmt->switch_expression);
806 	__save_switch_states(top_expression(switch_expr_stack));
807 	nullify_path();
808 	__push_default();
809 	__push_breaks();
810 
811 	stmt = stmt->switch_statement;
812 
813 	__push_scope_hooks();
814 	FOR_EACH_PTR(stmt->stmts, tmp) {
815 		__smatch_lineno = tmp->pos.line;
816 		if (is_case_val(tmp, sval)) {
817 			rl = alloc_rl(sval, sval);
818 			__merge_switches(top_expression(switch_expr_stack), rl);
819 			__pass_case_to_client(top_expression(switch_expr_stack), rl);
820 		}
821 		if (__path_is_null())
822 			continue;
823 		__split_stmt(tmp);
824 		if (__path_is_null()) {
825 			__set_default();
826 			goto out;
827 		}
828 	} END_FOR_EACH_PTR(tmp);
829 out:
830 	__call_scope_hooks();
831 	if (!__pop_default())
832 		__merge_switches(top_expression(switch_expr_stack), NULL);
833 	__discard_switches();
834 	__merge_breaks();
835 	pop_expression(&switch_expr_stack);
836 }
837 
838 static void split_case(struct statement *stmt)
839 {
840 	struct range_list *rl = NULL;
841 
842 	expr_set_parent_stmt(stmt->case_expression, stmt);
843 	expr_set_parent_stmt(stmt->case_to, stmt);
844 
845 	rl = get_case_rl(top_expression(switch_expr_stack),
846 			 stmt->case_expression, stmt->case_to);
847 	while (stmt->case_statement->type == STMT_CASE) {
848 		struct range_list *tmp;
849 
850 		tmp = get_case_rl(top_expression(switch_expr_stack),
851 				  stmt->case_statement->case_expression,
852 				  stmt->case_statement->case_to);
853 		if (!tmp)
854 			break;
855 		rl = rl_union(rl, tmp);
856 		if (!stmt->case_expression)
857 			__set_default();
858 		stmt = stmt->case_statement;
859 	}
860 
861 	__merge_switches(top_expression(switch_expr_stack), rl);
862 
863 	if (!stmt->case_expression)
864 		__set_default();
865 	__split_stmt(stmt->case_statement);
866 }
867 
868 int time_parsing_function(void)
869 {
870 	return ms_since(&fn_start_time) / 1000;
871 }
872 
873 /*
874  * This defaults to 60 * 5 == 5 minutes, so we'll just multiply
875  * whatever we're given by 5.
876  */
877 bool taking_too_long(void)
878 {
879 	if (option_timeout &&
880 	    (ms_since(&outer_fn_start_time) / 1000) > option_timeout * 5)
881 		return 1;
882 	return 0;
883 }
884 
885 static int is_last_stmt(struct statement *cur_stmt)
886 {
887 	struct symbol *fn;
888 	struct statement *stmt;
889 
890 	if (!cur_func_sym)
891 		return 0;
892 	fn = get_base_type(cur_func_sym);
893 	if (!fn)
894 		return 0;
895 	stmt = fn->stmt;
896 	if (!stmt)
897 		stmt = fn->inline_stmt;
898 	if (!stmt || stmt->type != STMT_COMPOUND)
899 		return 0;
900 	stmt = last_ptr_list((struct ptr_list *)stmt->stmts);
901 	if (stmt && stmt->type == STMT_LABEL)
902 		stmt = stmt->label_statement;
903 	if (stmt == cur_stmt)
904 		return 1;
905 	return 0;
906 }
907 
908 static void handle_backward_goto(struct statement *goto_stmt)
909 {
910 	const char *goto_name, *label_name;
911 	struct statement *func_stmt;
912 	struct symbol *base_type = get_base_type(cur_func_sym);
913 	struct statement *tmp;
914 	int found = 0;
915 
916 	if (!option_info)
917 		return;
918 	if (last_goto_statement_handled)
919 		return;
920 	last_goto_statement_handled = 1;
921 
922 	if (!goto_stmt->goto_label ||
923 	    goto_stmt->goto_label->type != SYM_LABEL ||
924 	    !goto_stmt->goto_label->ident)
925 		return;
926 	goto_name = goto_stmt->goto_label->ident->name;
927 
928 	func_stmt = base_type->stmt;
929 	if (!func_stmt)
930 		func_stmt = base_type->inline_stmt;
931 	if (!func_stmt)
932 		return;
933 	if (func_stmt->type != STMT_COMPOUND)
934 		return;
935 
936 	FOR_EACH_PTR(func_stmt->stmts, tmp) {
937 		if (!found) {
938 			if (tmp->type != STMT_LABEL)
939 				continue;
940 			if (!tmp->label_identifier ||
941 			    tmp->label_identifier->type != SYM_LABEL ||
942 			    !tmp->label_identifier->ident)
943 				continue;
944 			label_name = tmp->label_identifier->ident->name;
945 			if (strcmp(goto_name, label_name) != 0)
946 				continue;
947 			found = 1;
948 		}
949 		__split_stmt(tmp);
950 	} END_FOR_EACH_PTR(tmp);
951 }
952 
953 static void fake_a_return(void)
954 {
955 	struct symbol *return_type;
956 
957 	nullify_path();
958 	__unnullify_path();
959 
960 	return_type = get_real_base_type(cur_func_sym);
961 	return_type = get_real_base_type(return_type);
962 	if (return_type != &void_ctype) {
963 		__pass_to_client(unknown_value_expression(NULL), RETURN_HOOK);
964 		nullify_path();
965 	}
966 }
967 
968 static void fake_an_empty_default(struct position pos)
969 {
970 	static struct statement none = {};
971 
972 	none.pos = pos;
973 	none.type = STMT_NONE;
974 	__merge_switches(top_expression(switch_expr_stack), NULL);
975 	__split_stmt(&none);
976 }
977 
978 static void split_compound(struct statement *stmt)
979 {
980 	struct statement *prev = NULL;
981 	struct statement *cur = NULL;
982 	struct statement *next;
983 
984 	__push_scope_hooks();
985 
986 	FOR_EACH_PTR(stmt->stmts, next) {
987 		/* just set them all ahead of time */
988 		stmt_set_parent_stmt(next, stmt);
989 
990 		if (cur) {
991 			__prev_stmt = prev;
992 			__next_stmt = next;
993 			__cur_stmt = cur;
994 			__split_stmt(cur);
995 		}
996 		prev = cur;
997 		cur = next;
998 	} END_FOR_EACH_PTR(next);
999 	if (cur) {
1000 		__prev_stmt = prev;
1001 		__cur_stmt = cur;
1002 		__next_stmt = NULL;
1003 		__split_stmt(cur);
1004 	}
1005 
1006 	/*
1007 	 * For function scope, then delay calling the scope hooks until the
1008 	 * end of function hooks can run.  I'm not positive this is the right
1009 	 * thing...
1010 	 */
1011 	if (!is_last_stmt(cur))
1012 		__call_scope_hooks();
1013 }
1014 
1015 /*
1016  * This is a hack, work around for detecting empty functions.
1017  */
1018 static int need_delayed_scope_hooks(void)
1019 {
1020 	struct symbol *fn = get_base_type(cur_func_sym);
1021 	struct statement *stmt;
1022 
1023 	if (!fn)
1024 		return 0;
1025 	stmt = fn->stmt;
1026 	if (!stmt)
1027 		stmt = fn->inline_stmt;
1028 	if (stmt && stmt->type == STMT_COMPOUND)
1029 		return 1;
1030 	return 0;
1031 }
1032 
1033 void __split_label_stmt(struct statement *stmt)
1034 {
1035 	if (stmt->label_identifier &&
1036 	    stmt->label_identifier->type == SYM_LABEL &&
1037 	    stmt->label_identifier->ident) {
1038 		loop_count |= 0x0800000;
1039 		__merge_gotos(stmt->label_identifier->ident->name, stmt->label_identifier);
1040 	}
1041 }
1042 
1043 static void find_asm_gotos(struct statement *stmt)
1044 {
1045 	struct symbol *sym;
1046 
1047 	FOR_EACH_PTR(stmt->asm_labels, sym) {
1048 		__save_gotos(sym->ident->name, sym);
1049 	} END_FOR_EACH_PTR(sym);
1050 }
1051 
1052 void __split_stmt(struct statement *stmt)
1053 {
1054 	sval_t sval;
1055 
1056 	if (!stmt)
1057 		goto out;
1058 
1059 	if (!__in_fake_assign)
1060 		__silence_warnings_for_stmt = false;
1061 
1062 	if (__bail_on_rest_of_function || is_skipped_function())
1063 		return;
1064 
1065 	if (out_of_memory() || taking_too_long()) {
1066 		struct timeval stop;
1067 
1068 		gettimeofday(&stop, NULL);
1069 
1070 		__bail_on_rest_of_function = 1;
1071 		final_pass = 1;
1072 		sm_perror("Function too hairy.  Giving up. %lu seconds",
1073 		       stop.tv_sec - fn_start_time.tv_sec);
1074 		fake_a_return();
1075 		final_pass = 0;  /* turn off sm_msg() from here */
1076 		return;
1077 	}
1078 
1079 	add_ptr_list(&big_statement_stack, stmt);
1080 	free_expression_stack(&big_expression_stack);
1081 	set_position(stmt->pos);
1082 	__pass_to_client(stmt, STMT_HOOK);
1083 
1084 	switch (stmt->type) {
1085 	case STMT_DECLARATION:
1086 		split_declaration(stmt->declaration);
1087 		break;
1088 	case STMT_RETURN:
1089 		expr_set_parent_stmt(stmt->ret_value, stmt);
1090 
1091 		__split_expr(stmt->ret_value);
1092 		__pass_to_client(stmt->ret_value, RETURN_HOOK);
1093 		__process_post_op_stack();
1094 		nullify_path();
1095 		break;
1096 	case STMT_EXPRESSION:
1097 		expr_set_parent_stmt(stmt->expression, stmt);
1098 		expr_set_parent_stmt(stmt->context, stmt);
1099 
1100 		__split_expr(stmt->expression);
1101 		break;
1102 	case STMT_COMPOUND:
1103 		split_compound(stmt);
1104 		break;
1105 	case STMT_IF:
1106 		stmt_set_parent_stmt(stmt->if_true, stmt);
1107 		stmt_set_parent_stmt(stmt->if_false, stmt);
1108 		expr_set_parent_stmt(stmt->if_conditional, stmt);
1109 
1110 		if (known_condition_true(stmt->if_conditional)) {
1111 			__split_stmt(stmt->if_true);
1112 			break;
1113 		}
1114 		if (known_condition_false(stmt->if_conditional)) {
1115 			__split_stmt(stmt->if_false);
1116 			break;
1117 		}
1118 		__split_whole_condition(stmt->if_conditional);
1119 		__split_stmt(stmt->if_true);
1120 		if (empty_statement(stmt->if_true) &&
1121 			last_stmt_on_same_line() &&
1122 			!get_macro_name(stmt->if_true->pos))
1123 			sm_warning("if();");
1124 		__push_true_states();
1125 		__use_false_states();
1126 		__split_stmt(stmt->if_false);
1127 		__merge_true_states();
1128 		break;
1129 	case STMT_ITERATOR:
1130 		stmt_set_parent_stmt(stmt->iterator_pre_statement, stmt);
1131 		stmt_set_parent_stmt(stmt->iterator_statement, stmt);
1132 		stmt_set_parent_stmt(stmt->iterator_post_statement, stmt);
1133 		expr_set_parent_stmt(stmt->iterator_pre_condition, stmt);
1134 		expr_set_parent_stmt(stmt->iterator_post_condition, stmt);
1135 
1136 		if (stmt->iterator_pre_condition)
1137 			handle_pre_loop(stmt);
1138 		else if (stmt->iterator_post_condition)
1139 			handle_post_loop(stmt);
1140 		else {
1141 			// these are for(;;) type loops.
1142 			handle_pre_loop(stmt);
1143 		}
1144 		break;
1145 	case STMT_SWITCH:
1146 		stmt_set_parent_stmt(stmt->switch_statement, stmt);
1147 		expr_set_parent_stmt(stmt->switch_expression, stmt);
1148 
1149 		if (get_value(stmt->switch_expression, &sval)) {
1150 			split_known_switch(stmt, sval);
1151 			break;
1152 		}
1153 		__split_expr(stmt->switch_expression);
1154 		push_expression(&switch_expr_stack, stmt->switch_expression);
1155 		__save_switch_states(top_expression(switch_expr_stack));
1156 		nullify_path();
1157 		__push_default();
1158 		__push_breaks();
1159 		__split_stmt(stmt->switch_statement);
1160 		if (!__pop_default() && have_remaining_cases())
1161 			fake_an_empty_default(stmt->pos);
1162 		__discard_switches();
1163 		__merge_breaks();
1164 		pop_expression(&switch_expr_stack);
1165 		break;
1166 	case STMT_CASE:
1167 		split_case(stmt);
1168 		break;
1169 	case STMT_LABEL:
1170 		__split_label_stmt(stmt);
1171 		__split_stmt(stmt->label_statement);
1172 		break;
1173 	case STMT_GOTO:
1174 		expr_set_parent_stmt(stmt->goto_expression, stmt);
1175 
1176 		__split_expr(stmt->goto_expression);
1177 		if (stmt->goto_label && stmt->goto_label->type == SYM_NODE) {
1178 			if (!strcmp(stmt->goto_label->ident->name, "break")) {
1179 				__process_breaks();
1180 			} else if (!strcmp(stmt->goto_label->ident->name,
1181 					   "continue")) {
1182 				__process_continues();
1183 			}
1184 		} else if (stmt->goto_label &&
1185 			   stmt->goto_label->type == SYM_LABEL &&
1186 			   stmt->goto_label->ident) {
1187 			__save_gotos(stmt->goto_label->ident->name, stmt->goto_label);
1188 		}
1189 		nullify_path();
1190 		if (is_last_stmt(stmt))
1191 			handle_backward_goto(stmt);
1192 		break;
1193 	case STMT_NONE:
1194 		break;
1195 	case STMT_ASM:
1196 		expr_set_parent_stmt(stmt->asm_string, stmt);
1197 
1198 		find_asm_gotos(stmt);
1199 		__pass_to_client(stmt, ASM_HOOK);
1200 		__split_expr(stmt->asm_string);
1201 		split_asm_constraints(stmt->asm_outputs);
1202 		split_asm_constraints(stmt->asm_inputs);
1203 		split_asm_constraints(stmt->asm_clobbers);
1204 		break;
1205 	case STMT_CONTEXT:
1206 		break;
1207 	case STMT_RANGE:
1208 		__split_expr(stmt->range_expression);
1209 		__split_expr(stmt->range_low);
1210 		__split_expr(stmt->range_high);
1211 		break;
1212 	}
1213 	__pass_to_client(stmt, STMT_HOOK_AFTER);
1214 out:
1215 	__process_post_op_stack();
1216 }
1217 
1218 static void split_expr_list(struct expression_list *expr_list, struct expression *parent)
1219 {
1220 	struct expression *expr;
1221 
1222 	FOR_EACH_PTR(expr_list, expr) {
1223 		expr_set_parent_expr(expr, parent);
1224 		__split_expr(expr);
1225 		__process_post_op_stack();
1226 	} END_FOR_EACH_PTR(expr);
1227 }
1228 
1229 static void split_sym(struct symbol *sym)
1230 {
1231 	if (!sym)
1232 		return;
1233 	if (!(sym->namespace & NS_SYMBOL))
1234 		return;
1235 
1236 	__split_stmt(sym->stmt);
1237 	__split_expr(sym->array_size);
1238 	split_symlist(sym->arguments);
1239 	split_symlist(sym->symbol_list);
1240 	__split_stmt(sym->inline_stmt);
1241 	split_symlist(sym->inline_symbol_list);
1242 }
1243 
1244 static void split_symlist(struct symbol_list *sym_list)
1245 {
1246 	struct symbol *sym;
1247 
1248 	FOR_EACH_PTR(sym_list, sym) {
1249 		split_sym(sym);
1250 	} END_FOR_EACH_PTR(sym);
1251 }
1252 
1253 typedef void (fake_cb)(struct expression *expr);
1254 
1255 static int member_to_number(struct expression *expr, struct ident *member)
1256 {
1257 	struct symbol *type, *tmp;
1258 	char *name;
1259 	int i;
1260 
1261 	if (!member)
1262 		return -1;
1263 	name = member->name;
1264 
1265 	type = get_type(expr);
1266 	if (!type || type->type != SYM_STRUCT)
1267 		return -1;
1268 
1269 	i = -1;
1270 	FOR_EACH_PTR(type->symbol_list, tmp) {
1271 		i++;
1272 		if (!tmp->ident)
1273 			continue;
1274 		if (strcmp(name, tmp->ident->name) == 0)
1275 			return i;
1276 	} END_FOR_EACH_PTR(tmp);
1277 	return -1;
1278 }
1279 
1280 static struct ident *number_to_member(struct expression *expr, int num)
1281 {
1282 	struct symbol *type, *member;
1283 	int i = 0;
1284 
1285 	type = get_type(expr);
1286 	if (!type || type->type != SYM_STRUCT)
1287 		return NULL;
1288 
1289 	FOR_EACH_PTR(type->symbol_list, member) {
1290 		if (i == num)
1291 			return member->ident;
1292 		i++;
1293 	} END_FOR_EACH_PTR(member);
1294 	return NULL;
1295 }
1296 
1297 static void fake_element_assigns_helper(struct expression *array, struct expression_list *expr_list, fake_cb *fake_cb);
1298 
1299 static void set_inner_struct_members(struct expression *expr, struct symbol *member)
1300 {
1301 	struct expression *edge_member, *assign;
1302 	struct symbol *base = get_real_base_type(member);
1303 	struct symbol *tmp;
1304 
1305 	if (member->ident)
1306 		expr = member_expression(expr, '.', member->ident);
1307 
1308 	FOR_EACH_PTR(base->symbol_list, tmp) {
1309 		struct symbol *type;
1310 
1311 		type = get_real_base_type(tmp);
1312 		if (!type)
1313 			continue;
1314 
1315 		edge_member = member_expression(expr, '.', tmp->ident);
1316 		if (get_extra_state(edge_member))
1317 			continue;
1318 
1319 		if (type->type == SYM_UNION || type->type == SYM_STRUCT) {
1320 			set_inner_struct_members(expr, tmp);
1321 			continue;
1322 		}
1323 
1324 		if (!tmp->ident)
1325 			continue;
1326 
1327 		assign = assign_expression(edge_member, '=', zero_expr());
1328 		__split_expr(assign);
1329 	} END_FOR_EACH_PTR(tmp);
1330 
1331 
1332 }
1333 
1334 static void set_unset_to_zero(struct symbol *type, struct expression *expr)
1335 {
1336 	struct symbol *tmp;
1337 	struct expression *member = NULL;
1338 	struct expression *assign;
1339 	int op = '*';
1340 
1341 	if (expr->type == EXPR_PREOP && expr->op == '&') {
1342 		expr = strip_expr(expr->unop);
1343 		op = '.';
1344 	}
1345 
1346 	FOR_EACH_PTR(type->symbol_list, tmp) {
1347 		type = get_real_base_type(tmp);
1348 		if (!type)
1349 			continue;
1350 
1351 		if (tmp->ident) {
1352 			member = member_expression(expr, op, tmp->ident);
1353 			if (get_extra_state(member))
1354 				continue;
1355 		}
1356 
1357 		if (type->type == SYM_UNION || type->type == SYM_STRUCT) {
1358 			set_inner_struct_members(expr, tmp);
1359 			continue;
1360 		}
1361 		if (type->type == SYM_ARRAY)
1362 			continue;
1363 		if (!tmp->ident)
1364 			continue;
1365 
1366 		assign = assign_expression(member, '=', zero_expr());
1367 		__split_expr(assign);
1368 	} END_FOR_EACH_PTR(tmp);
1369 }
1370 
1371 static void fake_member_assigns_helper(struct expression *symbol, struct expression_list *members, fake_cb *fake_cb)
1372 {
1373 	struct expression *deref, *assign, *tmp, *right;
1374 	struct symbol *struct_type, *type;
1375 	struct ident *member;
1376 	int member_idx;
1377 
1378 	struct_type = get_type(symbol);
1379 	if (!struct_type ||
1380 	    (struct_type->type != SYM_STRUCT && struct_type->type != SYM_UNION))
1381 		return;
1382 
1383 	/*
1384 	 * We're parsing an initializer that could look something like this:
1385 	 * struct foo foo = {
1386 	 *	42,
1387 	 *	.whatever.xxx = 11,
1388 	 *	.zzz = 12,
1389 	 * };
1390 	 *
1391 	 * So what we have here is a list with 42, .whatever, and .zzz.  We need
1392 	 * to break it up into left and right sides of the assignments.
1393 	 *
1394 	 */
1395 	member_idx = 0;
1396 	FOR_EACH_PTR(members, tmp) {
1397 		deref = NULL;
1398 		if (tmp->type == EXPR_IDENTIFIER) {
1399 			member_idx = member_to_number(symbol, tmp->expr_ident);
1400 			while (tmp->type == EXPR_IDENTIFIER) {
1401 				member = tmp->expr_ident;
1402 				tmp = tmp->ident_expression;
1403 				if (deref)
1404 					deref = member_expression(deref, '.', member);
1405 				else
1406 					deref = member_expression(symbol, '.', member);
1407 			}
1408 		} else {
1409 			member = number_to_member(symbol, member_idx);
1410 			deref = member_expression(symbol, '.', member);
1411 		}
1412 		right = tmp;
1413 		member_idx++;
1414 		if (right->type == EXPR_INITIALIZER) {
1415 			type = get_type(deref);
1416 			if (type && type->type == SYM_ARRAY)
1417 				fake_element_assigns_helper(deref, right->expr_list, fake_cb);
1418 			else
1419 				fake_member_assigns_helper(deref, right->expr_list, fake_cb);
1420 		} else {
1421 			assign = assign_expression(deref, '=', right);
1422 			fake_cb(assign);
1423 		}
1424 	} END_FOR_EACH_PTR(tmp);
1425 
1426 	set_unset_to_zero(struct_type, symbol);
1427 }
1428 
1429 static void fake_member_assigns(struct symbol *sym, fake_cb *fake_cb)
1430 {
1431 	fake_member_assigns_helper(symbol_expression(sym),
1432 				   sym->initializer->expr_list, fake_cb);
1433 }
1434 
1435 static void fake_element_assigns_helper(struct expression *array, struct expression_list *expr_list, fake_cb *fake_cb)
1436 {
1437 	struct expression *offset, *binop, *assign, *tmp;
1438 	struct symbol *type;
1439 	int idx;
1440 
1441 	if (ptr_list_size((struct ptr_list *)expr_list) > 1000)
1442 		return;
1443 
1444 	idx = 0;
1445 	FOR_EACH_PTR(expr_list, tmp) {
1446 		if (tmp->type == EXPR_INDEX) {
1447 			if (tmp->idx_from != tmp->idx_to)
1448 				return;
1449 			idx = tmp->idx_from;
1450 			if (!tmp->idx_expression)
1451 				goto next;
1452 			tmp = tmp->idx_expression;
1453 		}
1454 		offset = value_expr(idx);
1455 		binop = array_element_expression(array, offset);
1456 		if (tmp->type == EXPR_INITIALIZER) {
1457 			type = get_type(binop);
1458 			if (type && type->type == SYM_ARRAY)
1459 				fake_element_assigns_helper(binop, tmp->expr_list, fake_cb);
1460 			else
1461 				fake_member_assigns_helper(binop, tmp->expr_list, fake_cb);
1462 		} else {
1463 			assign = assign_expression(binop, '=', tmp);
1464 			fake_cb(assign);
1465 		}
1466 next:
1467 		idx++;
1468 	} END_FOR_EACH_PTR(tmp);
1469 }
1470 
1471 static void fake_element_assigns(struct symbol *sym, fake_cb *fake_cb)
1472 {
1473 	fake_element_assigns_helper(symbol_expression(sym), sym->initializer->expr_list, fake_cb);
1474 }
1475 
1476 static void fake_assign_expr(struct symbol *sym)
1477 {
1478 	struct expression *assign, *symbol;
1479 
1480 	symbol = symbol_expression(sym);
1481 	assign = assign_expression(symbol, '=', sym->initializer);
1482 	__split_expr(assign);
1483 }
1484 
1485 static void do_initializer_stuff(struct symbol *sym)
1486 {
1487 	if (!sym->initializer)
1488 		return;
1489 
1490 	if (sym->initializer->type == EXPR_INITIALIZER) {
1491 		if (get_real_base_type(sym)->type == SYM_ARRAY)
1492 			fake_element_assigns(sym, __split_expr);
1493 		else
1494 			fake_member_assigns(sym, __split_expr);
1495 	} else {
1496 		fake_assign_expr(sym);
1497 	}
1498 }
1499 
1500 static void split_declaration(struct symbol_list *sym_list)
1501 {
1502 	struct symbol *sym;
1503 
1504 	FOR_EACH_PTR(sym_list, sym) {
1505 		__pass_to_client(sym, DECLARATION_HOOK);
1506 		do_initializer_stuff(sym);
1507 		split_sym(sym);
1508 	} END_FOR_EACH_PTR(sym);
1509 }
1510 
1511 static void call_global_assign_hooks(struct expression *assign)
1512 {
1513 	__pass_to_client(assign, GLOBAL_ASSIGNMENT_HOOK);
1514 }
1515 
1516 static void fake_global_assign(struct symbol *sym)
1517 {
1518 	struct expression *assign, *symbol;
1519 
1520 	if (get_real_base_type(sym)->type == SYM_ARRAY) {
1521 		if (sym->initializer && sym->initializer->type == EXPR_INITIALIZER) {
1522 			fake_element_assigns(sym, call_global_assign_hooks);
1523 		} else if (sym->initializer) {
1524 			symbol = symbol_expression(sym);
1525 			assign = assign_expression(symbol, '=', sym->initializer);
1526 			__pass_to_client(assign, GLOBAL_ASSIGNMENT_HOOK);
1527 		} else {
1528 			fake_element_assigns_helper(symbol_expression(sym), NULL, call_global_assign_hooks);
1529 		}
1530 	} else if (get_real_base_type(sym)->type == SYM_STRUCT) {
1531 		if (sym->initializer && sym->initializer->type == EXPR_INITIALIZER) {
1532 			fake_member_assigns(sym, call_global_assign_hooks);
1533 		} else if (sym->initializer) {
1534 			symbol = symbol_expression(sym);
1535 			assign = assign_expression(symbol, '=', sym->initializer);
1536 			__pass_to_client(assign, GLOBAL_ASSIGNMENT_HOOK);
1537 		} else {
1538 			fake_member_assigns_helper(symbol_expression(sym), NULL, call_global_assign_hooks);
1539 		}
1540 	} else {
1541 		symbol = symbol_expression(sym);
1542 		if (sym->initializer) {
1543 			assign = assign_expression(symbol, '=', sym->initializer);
1544 			__split_expr(assign);
1545 		} else {
1546 			assign = assign_expression(symbol, '=', zero_expr());
1547 		}
1548 		__pass_to_client(assign, GLOBAL_ASSIGNMENT_HOOK);
1549 	}
1550 }
1551 
1552 static void start_function_definition(struct symbol *sym)
1553 {
1554 	__in_function_def = 1;
1555 	__pass_to_client(sym, FUNC_DEF_HOOK);
1556 	__in_function_def = 0;
1557 	__pass_to_client(sym, AFTER_DEF_HOOK);
1558 
1559 }
1560 
1561 static void split_function(struct symbol *sym)
1562 {
1563 	struct symbol *base_type = get_base_type(sym);
1564 	struct timeval stop;
1565 
1566 	if (!base_type->stmt && !base_type->inline_stmt)
1567 		return;
1568 
1569 	gettimeofday(&outer_fn_start_time, NULL);
1570 	gettimeofday(&fn_start_time, NULL);
1571 	cur_func_sym = sym;
1572 	if (sym->ident)
1573 		cur_func = sym->ident->name;
1574 	set_position(sym->pos);
1575 	loop_count = 0;
1576 	last_goto_statement_handled = 0;
1577 	sm_debug("new function:  %s\n", cur_func);
1578 	__stree_id = 0;
1579 	if (option_two_passes) {
1580 		__unnullify_path();
1581 		loop_num = 0;
1582 		final_pass = 0;
1583 		start_function_definition(sym);
1584 		__split_stmt(base_type->stmt);
1585 		__split_stmt(base_type->inline_stmt);
1586 		nullify_path();
1587 	}
1588 	__unnullify_path();
1589 	loop_num = 0;
1590 	final_pass = 1;
1591 	start_function_definition(sym);
1592 	__split_stmt(base_type->stmt);
1593 	__split_stmt(base_type->inline_stmt);
1594 	__pass_to_client(sym, END_FUNC_HOOK);
1595 	if (need_delayed_scope_hooks())
1596 		__call_scope_hooks();
1597 	__pass_to_client(sym, AFTER_FUNC_HOOK);
1598 
1599 	clear_all_states();
1600 
1601 	gettimeofday(&stop, NULL);
1602 	if (option_time && stop.tv_sec - fn_start_time.tv_sec > 2) {
1603 		final_pass++;
1604 		sm_msg("func_time: %lu", stop.tv_sec - fn_start_time.tv_sec);
1605 		final_pass--;
1606 	}
1607 	cur_func_sym = NULL;
1608 	cur_func = NULL;
1609 	free_data_info_allocs();
1610 	free_expression_stack(&switch_expr_stack);
1611 	__free_ptr_list((struct ptr_list **)&big_statement_stack);
1612 	__bail_on_rest_of_function = 0;
1613 }
1614 
1615 static void save_flow_state(void)
1616 {
1617 	__add_ptr_list(&backup, INT_PTR(loop_num << 2), 0);
1618 	__add_ptr_list(&backup, INT_PTR(loop_count << 2), 0);
1619 	__add_ptr_list(&backup, INT_PTR(final_pass << 2), 0);
1620 
1621 	__add_ptr_list(&backup, big_statement_stack, 0);
1622 	__add_ptr_list(&backup, big_expression_stack, 0);
1623 	__add_ptr_list(&backup, big_condition_stack, 0);
1624 	__add_ptr_list(&backup, switch_expr_stack, 0);
1625 
1626 	__add_ptr_list(&backup, cur_func_sym, 0);
1627 
1628 	__add_ptr_list(&backup, __prev_stmt, 0);
1629 	__add_ptr_list(&backup, __cur_stmt, 0);
1630 	__add_ptr_list(&backup, __next_stmt, 0);
1631 
1632 }
1633 
1634 static void *pop_backup(void)
1635 {
1636 	void *ret;
1637 
1638 	ret = last_ptr_list(backup);
1639 	delete_ptr_list_last(&backup);
1640 	return ret;
1641 }
1642 
1643 static void restore_flow_state(void)
1644 {
1645 	__next_stmt = pop_backup();
1646 	__cur_stmt = pop_backup();
1647 	__prev_stmt = pop_backup();
1648 
1649 	cur_func_sym = pop_backup();
1650 	switch_expr_stack = pop_backup();
1651 	big_condition_stack = pop_backup();
1652 	big_expression_stack = pop_backup();
1653 	big_statement_stack = pop_backup();
1654 	final_pass = PTR_INT(pop_backup()) >> 2;
1655 	loop_count = PTR_INT(pop_backup()) >> 2;
1656 	loop_num = PTR_INT(pop_backup()) >> 2;
1657 }
1658 
1659 static void parse_inline(struct expression *call)
1660 {
1661 	struct symbol *base_type;
1662 	char *cur_func_bak = cur_func;  /* not aligned correctly for backup */
1663 	struct timeval time_backup = fn_start_time;
1664 	struct expression *orig_inline = __inline_fn;
1665 	int orig_budget;
1666 
1667 	if (out_of_memory() || taking_too_long())
1668 		return;
1669 
1670 	save_flow_state();
1671 
1672 	__pass_to_client(call, INLINE_FN_START);
1673 	final_pass = 0;  /* don't print anything */
1674 	__inline_fn = call;
1675 	orig_budget = inline_budget;
1676 	inline_budget = inline_budget - 5;
1677 
1678 	base_type = get_base_type(call->fn->symbol);
1679 	cur_func_sym = call->fn->symbol;
1680 	if (call->fn->symbol->ident)
1681 		cur_func = call->fn->symbol->ident->name;
1682 	else
1683 		cur_func = NULL;
1684 	set_position(call->fn->symbol->pos);
1685 
1686 	save_all_states();
1687 	big_statement_stack = NULL;
1688 	big_expression_stack = NULL;
1689 	big_condition_stack = NULL;
1690 	switch_expr_stack = NULL;
1691 
1692 	sm_debug("inline function:  %s\n", cur_func);
1693 	__unnullify_path();
1694 	loop_num = 0;
1695 	loop_count = 0;
1696 	start_function_definition(call->fn->symbol);
1697 	__split_stmt(base_type->stmt);
1698 	__split_stmt(base_type->inline_stmt);
1699 	__pass_to_client(call->fn->symbol, END_FUNC_HOOK);
1700 	__pass_to_client(call->fn->symbol, AFTER_FUNC_HOOK);
1701 
1702 	free_expression_stack(&switch_expr_stack);
1703 	__free_ptr_list((struct ptr_list **)&big_statement_stack);
1704 	nullify_path();
1705 	free_goto_stack();
1706 
1707 	restore_flow_state();
1708 	fn_start_time = time_backup;
1709 	cur_func = cur_func_bak;
1710 
1711 	restore_all_states();
1712 	set_position(call->pos);
1713 	__inline_fn = orig_inline;
1714 	inline_budget = orig_budget;
1715 	__pass_to_client(call, INLINE_FN_END);
1716 }
1717 
1718 static struct symbol_list *inlines_called;
1719 static void add_inline_function(struct symbol *sym)
1720 {
1721 	static struct symbol_list *already_added;
1722 	struct symbol *tmp;
1723 
1724 	FOR_EACH_PTR(already_added, tmp) {
1725 		if (tmp == sym)
1726 			return;
1727 	} END_FOR_EACH_PTR(tmp);
1728 
1729 	add_ptr_list(&already_added, sym);
1730 	add_ptr_list(&inlines_called, sym);
1731 }
1732 
1733 static void process_inlines(void)
1734 {
1735 	struct symbol *tmp;
1736 
1737 	FOR_EACH_PTR(inlines_called, tmp) {
1738 		split_function(tmp);
1739 	} END_FOR_EACH_PTR(tmp);
1740 	free_ptr_list(&inlines_called);
1741 }
1742 
1743 static struct symbol *get_last_scoped_symbol(struct symbol_list *big_list, int use_static)
1744 {
1745 	struct symbol *sym;
1746 
1747 	FOR_EACH_PTR_REVERSE(big_list, sym) {
1748 		if (!sym->scope)
1749 			continue;
1750 		if (use_static && sym->ctype.modifiers & MOD_STATIC)
1751 			return sym;
1752 		if (!use_static && !(sym->ctype.modifiers & MOD_STATIC))
1753 			return sym;
1754 	} END_FOR_EACH_PTR_REVERSE(sym);
1755 
1756 	return NULL;
1757 }
1758 
1759 static bool interesting_function(struct symbol *sym)
1760 {
1761 	static int prev_stream = -1;
1762 	static bool prev_answer;
1763 	const char *filename;
1764 	int len;
1765 
1766 	if (!(sym->ctype.modifiers & MOD_INLINE))
1767 		return true;
1768 
1769 	if (sym->pos.stream == prev_stream)
1770 		return prev_answer;
1771 
1772 	prev_stream = sym->pos.stream;
1773 	prev_answer = false;
1774 
1775 	filename = stream_name(sym->pos.stream);
1776 	len = strlen(filename);
1777 	if (len > 0 && filename[len - 1] == 'c')
1778 		prev_answer = true;
1779 	return prev_answer;
1780 }
1781 
1782 static void split_inlines_in_scope(struct symbol *sym)
1783 {
1784 	struct symbol *base;
1785 	struct symbol_list *scope_list;
1786 	int stream;
1787 
1788 	scope_list = sym->scope->symbols;
1789 	stream = sym->pos.stream;
1790 
1791 	/* find the last static symbol in the file */
1792 	FOR_EACH_PTR_REVERSE(scope_list, sym) {
1793 		if (sym->pos.stream != stream)
1794 			continue;
1795 		if (sym->type != SYM_NODE)
1796 			continue;
1797 		base = get_base_type(sym);
1798 		if (!base)
1799 			continue;
1800 		if (base->type != SYM_FN)
1801 			continue;
1802 		if (!base->inline_stmt)
1803 			continue;
1804 		if (!interesting_function(sym))
1805 			continue;
1806 		add_inline_function(sym);
1807 	} END_FOR_EACH_PTR_REVERSE(sym);
1808 
1809 	process_inlines();
1810 }
1811 
1812 static void split_inlines(struct symbol_list *sym_list)
1813 {
1814 	struct symbol *sym;
1815 
1816 	sym = get_last_scoped_symbol(sym_list, 0);
1817 	if (sym)
1818 		split_inlines_in_scope(sym);
1819 	sym = get_last_scoped_symbol(sym_list, 1);
1820 	if (sym)
1821 		split_inlines_in_scope(sym);
1822 }
1823 
1824 static struct stree *clone_estates_perm(struct stree *orig)
1825 {
1826 	struct stree *ret = NULL;
1827 	struct sm_state *tmp;
1828 
1829 	FOR_EACH_SM(orig, tmp) {
1830 		set_state_stree_perm(&ret, tmp->owner, tmp->name, tmp->sym, clone_estate_perm(tmp->state));
1831 	} END_FOR_EACH_SM(tmp);
1832 
1833 	return ret;
1834 }
1835 
1836 struct position last_pos;
1837 static void split_c_file_functions(struct symbol_list *sym_list)
1838 {
1839 	struct symbol *sym;
1840 
1841 	__unnullify_path();
1842 	FOR_EACH_PTR(sym_list, sym) {
1843 		set_position(sym->pos);
1844 		if (sym->type != SYM_NODE || get_base_type(sym)->type != SYM_FN) {
1845 			__pass_to_client(sym, BASE_HOOK);
1846 			fake_global_assign(sym);
1847 		}
1848 	} END_FOR_EACH_PTR(sym);
1849 	global_states = clone_estates_perm(get_all_states_stree(SMATCH_EXTRA));
1850 	nullify_path();
1851 
1852 	FOR_EACH_PTR(sym_list, sym) {
1853 		set_position(sym->pos);
1854 		last_pos = sym->pos;
1855 		if (!interesting_function(sym))
1856 			continue;
1857 		if (sym->type == SYM_NODE && get_base_type(sym)->type == SYM_FN) {
1858 			split_function(sym);
1859 			process_inlines();
1860 		}
1861 		last_pos = sym->pos;
1862 	} END_FOR_EACH_PTR(sym);
1863 	split_inlines(sym_list);
1864 	__pass_to_client(sym_list, END_FILE_HOOK);
1865 }
1866 
1867 static int final_before_fake;
1868 void init_fake_env(void)
1869 {
1870 	if (!in_fake_env)
1871 		final_before_fake = final_pass;
1872 	in_fake_env++;
1873 	__push_fake_cur_stree();
1874 	final_pass = 0;
1875 }
1876 
1877 void end_fake_env(void)
1878 {
1879 	__pop_fake_cur_stree();
1880 	in_fake_env--;
1881 	if (!in_fake_env)
1882 		final_pass = final_before_fake;
1883 }
1884 
1885 static void open_output_files(char *base_file)
1886 {
1887 	char buf[256];
1888 
1889 	snprintf(buf, sizeof(buf), "%s.smatch", base_file);
1890 	sm_outfd = fopen(buf, "w");
1891 	if (!sm_outfd)
1892 		sm_fatal("Cannot open %s", buf);
1893 
1894 	if (!option_info)
1895 		return;
1896 
1897 	snprintf(buf, sizeof(buf), "%s.smatch.sql", base_file);
1898 	sql_outfd = fopen(buf, "w");
1899 	if (!sql_outfd)
1900 		sm_fatal("Error:  Cannot open %s", buf);
1901 
1902 	snprintf(buf, sizeof(buf), "%s.smatch.caller_info", base_file);
1903 	caller_info_fd = fopen(buf, "w");
1904 	if (!caller_info_fd)
1905 		sm_fatal("Error:  Cannot open %s", buf);
1906 }
1907 
1908 void smatch(struct string_list *filelist)
1909 {
1910 	struct symbol_list *sym_list;
1911 	struct timeval stop, start;
1912 	char *path;
1913 	int len;
1914 
1915 	gettimeofday(&start, NULL);
1916 
1917 	FOR_EACH_PTR_NOTAG(filelist, base_file) {
1918 		path = getcwd(NULL, 0);
1919 		free(full_base_file);
1920 		if (path) {
1921 			len = strlen(path) + 1 + strlen(base_file) + 1;
1922 			full_base_file = malloc(len);
1923 			snprintf(full_base_file, len, "%s/%s", path, base_file);
1924 		} else {
1925 			full_base_file = alloc_string(base_file);
1926 		}
1927 		if (option_file_output)
1928 			open_output_files(base_file);
1929 		sym_list = sparse_keep_tokens(base_file);
1930 		split_c_file_functions(sym_list);
1931 	} END_FOR_EACH_PTR_NOTAG(base_file);
1932 
1933 	gettimeofday(&stop, NULL);
1934 
1935 	set_position(last_pos);
1936 	final_pass = 1;
1937 	if (option_time)
1938 		sm_msg("time: %lu", stop.tv_sec - start.tv_sec);
1939 	if (option_mem)
1940 		sm_msg("mem: %luKb", get_max_memory());
1941 }
1942