xref: /openbmc/linux/scripts/kconfig/symbol.c (revision 93dc544c) 
1 /*
2  * Copyright (C) 2002 Roman Zippel <zippel@linux-m68k.org>
3  * Released under the terms of the GNU GPL v2.0.
4  */
5 
6 #include <ctype.h>
7 #include <stdlib.h>
8 #include <string.h>
9 #include <regex.h>
10 #include <sys/utsname.h>
11 
12 #define LKC_DIRECT_LINK
13 #include "lkc.h"
14 
15 struct symbol symbol_yes = {
16 	.name = "y",
17 	.curr = { "y", yes },
18 	.flags = SYMBOL_CONST|SYMBOL_VALID,
19 }, symbol_mod = {
20 	.name = "m",
21 	.curr = { "m", mod },
22 	.flags = SYMBOL_CONST|SYMBOL_VALID,
23 }, symbol_no = {
24 	.name = "n",
25 	.curr = { "n", no },
26 	.flags = SYMBOL_CONST|SYMBOL_VALID,
27 }, symbol_empty = {
28 	.name = "",
29 	.curr = { "", no },
30 	.flags = SYMBOL_VALID,
31 };
32 
33 struct symbol *sym_defconfig_list;
34 struct symbol *modules_sym;
35 tristate modules_val;
36 
37 struct expr *sym_env_list;
38 
39 void sym_add_default(struct symbol *sym, const char *def)
40 {
41 	struct property *prop = prop_alloc(P_DEFAULT, sym);
42 
43 	prop->expr = expr_alloc_symbol(sym_lookup(def, SYMBOL_CONST));
44 }
45 
46 void sym_init(void)
47 {
48 	struct symbol *sym;
49 	struct utsname uts;
50 	static bool inited = false;
51 
52 	if (inited)
53 		return;
54 	inited = true;
55 
56 	uname(&uts);
57 
58 	sym = sym_lookup("UNAME_RELEASE", 0);
59 	sym->type = S_STRING;
60 	sym->flags |= SYMBOL_AUTO;
61 	sym_add_default(sym, uts.release);
62 }
63 
64 enum symbol_type sym_get_type(struct symbol *sym)
65 {
66 	enum symbol_type type = sym->type;
67 
68 	if (type == S_TRISTATE) {
69 		if (sym_is_choice_value(sym) && sym->visible == yes)
70 			type = S_BOOLEAN;
71 		else if (modules_val == no)
72 			type = S_BOOLEAN;
73 	}
74 	return type;
75 }
76 
77 const char *sym_type_name(enum symbol_type type)
78 {
79 	switch (type) {
80 	case S_BOOLEAN:
81 		return "boolean";
82 	case S_TRISTATE:
83 		return "tristate";
84 	case S_INT:
85 		return "integer";
86 	case S_HEX:
87 		return "hex";
88 	case S_STRING:
89 		return "string";
90 	case S_UNKNOWN:
91 		return "unknown";
92 	case S_OTHER:
93 		break;
94 	}
95 	return "???";
96 }
97 
98 struct property *sym_get_choice_prop(struct symbol *sym)
99 {
100 	struct property *prop;
101 
102 	for_all_choices(sym, prop)
103 		return prop;
104 	return NULL;
105 }
106 
107 struct property *sym_get_env_prop(struct symbol *sym)
108 {
109 	struct property *prop;
110 
111 	for_all_properties(sym, prop, P_ENV)
112 		return prop;
113 	return NULL;
114 }
115 
116 struct property *sym_get_default_prop(struct symbol *sym)
117 {
118 	struct property *prop;
119 
120 	for_all_defaults(sym, prop) {
121 		prop->visible.tri = expr_calc_value(prop->visible.expr);
122 		if (prop->visible.tri != no)
123 			return prop;
124 	}
125 	return NULL;
126 }
127 
128 struct property *sym_get_range_prop(struct symbol *sym)
129 {
130 	struct property *prop;
131 
132 	for_all_properties(sym, prop, P_RANGE) {
133 		prop->visible.tri = expr_calc_value(prop->visible.expr);
134 		if (prop->visible.tri != no)
135 			return prop;
136 	}
137 	return NULL;
138 }
139 
140 static int sym_get_range_val(struct symbol *sym, int base)
141 {
142 	sym_calc_value(sym);
143 	switch (sym->type) {
144 	case S_INT:
145 		base = 10;
146 		break;
147 	case S_HEX:
148 		base = 16;
149 		break;
150 	default:
151 		break;
152 	}
153 	return strtol(sym->curr.val, NULL, base);
154 }
155 
156 static void sym_validate_range(struct symbol *sym)
157 {
158 	struct property *prop;
159 	int base, val, val2;
160 	char str[64];
161 
162 	switch (sym->type) {
163 	case S_INT:
164 		base = 10;
165 		break;
166 	case S_HEX:
167 		base = 16;
168 		break;
169 	default:
170 		return;
171 	}
172 	prop = sym_get_range_prop(sym);
173 	if (!prop)
174 		return;
175 	val = strtol(sym->curr.val, NULL, base);
176 	val2 = sym_get_range_val(prop->expr->left.sym, base);
177 	if (val >= val2) {
178 		val2 = sym_get_range_val(prop->expr->right.sym, base);
179 		if (val <= val2)
180 			return;
181 	}
182 	if (sym->type == S_INT)
183 		sprintf(str, "%d", val2);
184 	else
185 		sprintf(str, "0x%x", val2);
186 	sym->curr.val = strdup(str);
187 }
188 
189 static void sym_calc_visibility(struct symbol *sym)
190 {
191 	struct property *prop;
192 	tristate tri;
193 
194 	/* any prompt visible? */
195 	tri = no;
196 	for_all_prompts(sym, prop) {
197 		prop->visible.tri = expr_calc_value(prop->visible.expr);
198 		tri = EXPR_OR(tri, prop->visible.tri);
199 	}
200 	if (tri == mod && (sym->type != S_TRISTATE || modules_val == no))
201 		tri = yes;
202 	if (sym->visible != tri) {
203 		sym->visible = tri;
204 		sym_set_changed(sym);
205 	}
206 	if (sym_is_choice_value(sym))
207 		return;
208 	tri = no;
209 	if (sym->rev_dep.expr)
210 		tri = expr_calc_value(sym->rev_dep.expr);
211 	if (tri == mod && sym_get_type(sym) == S_BOOLEAN)
212 		tri = yes;
213 	if (sym->rev_dep.tri != tri) {
214 		sym->rev_dep.tri = tri;
215 		sym_set_changed(sym);
216 	}
217 }
218 
219 static struct symbol *sym_calc_choice(struct symbol *sym)
220 {
221 	struct symbol *def_sym;
222 	struct property *prop;
223 	struct expr *e;
224 
225 	/* is the user choice visible? */
226 	def_sym = sym->def[S_DEF_USER].val;
227 	if (def_sym) {
228 		sym_calc_visibility(def_sym);
229 		if (def_sym->visible != no)
230 			return def_sym;
231 	}
232 
233 	/* any of the defaults visible? */
234 	for_all_defaults(sym, prop) {
235 		prop->visible.tri = expr_calc_value(prop->visible.expr);
236 		if (prop->visible.tri == no)
237 			continue;
238 		def_sym = prop_get_symbol(prop);
239 		sym_calc_visibility(def_sym);
240 		if (def_sym->visible != no)
241 			return def_sym;
242 	}
243 
244 	/* just get the first visible value */
245 	prop = sym_get_choice_prop(sym);
246 	expr_list_for_each_sym(prop->expr, e, def_sym) {
247 		sym_calc_visibility(def_sym);
248 		if (def_sym->visible != no)
249 			return def_sym;
250 	}
251 
252 	/* no choice? reset tristate value */
253 	sym->curr.tri = no;
254 	return NULL;
255 }
256 
257 void sym_calc_value(struct symbol *sym)
258 {
259 	struct symbol_value newval, oldval;
260 	struct property *prop;
261 	struct expr *e;
262 
263 	if (!sym)
264 		return;
265 
266 	if (sym->flags & SYMBOL_VALID)
267 		return;
268 	sym->flags |= SYMBOL_VALID;
269 
270 	oldval = sym->curr;
271 
272 	switch (sym->type) {
273 	case S_INT:
274 	case S_HEX:
275 	case S_STRING:
276 		newval = symbol_empty.curr;
277 		break;
278 	case S_BOOLEAN:
279 	case S_TRISTATE:
280 		newval = symbol_no.curr;
281 		break;
282 	default:
283 		sym->curr.val = sym->name;
284 		sym->curr.tri = no;
285 		return;
286 	}
287 	if (!sym_is_choice_value(sym))
288 		sym->flags &= ~SYMBOL_WRITE;
289 
290 	sym_calc_visibility(sym);
291 
292 	/* set default if recursively called */
293 	sym->curr = newval;
294 
295 	switch (sym_get_type(sym)) {
296 	case S_BOOLEAN:
297 	case S_TRISTATE:
298 		if (sym_is_choice_value(sym) && sym->visible == yes) {
299 			prop = sym_get_choice_prop(sym);
300 			newval.tri = (prop_get_symbol(prop)->curr.val == sym) ? yes : no;
301 		} else {
302 			if (sym->visible != no) {
303 				/* if the symbol is visible use the user value
304 				 * if available, otherwise try the default value
305 				 */
306 				sym->flags |= SYMBOL_WRITE;
307 				if (sym_has_value(sym)) {
308 					newval.tri = EXPR_AND(sym->def[S_DEF_USER].tri,
309 							      sym->visible);
310 					goto calc_newval;
311 				}
312 			}
313 			if (sym->rev_dep.tri != no)
314 				sym->flags |= SYMBOL_WRITE;
315 			if (!sym_is_choice(sym)) {
316 				prop = sym_get_default_prop(sym);
317 				if (prop) {
318 					sym->flags |= SYMBOL_WRITE;
319 					newval.tri = EXPR_AND(expr_calc_value(prop->expr),
320 							      prop->visible.tri);
321 				}
322 			}
323 		calc_newval:
324 			newval.tri = EXPR_OR(newval.tri, sym->rev_dep.tri);
325 		}
326 		if (newval.tri == mod && sym_get_type(sym) == S_BOOLEAN)
327 			newval.tri = yes;
328 		break;
329 	case S_STRING:
330 	case S_HEX:
331 	case S_INT:
332 		if (sym->visible != no) {
333 			sym->flags |= SYMBOL_WRITE;
334 			if (sym_has_value(sym)) {
335 				newval.val = sym->def[S_DEF_USER].val;
336 				break;
337 			}
338 		}
339 		prop = sym_get_default_prop(sym);
340 		if (prop) {
341 			struct symbol *ds = prop_get_symbol(prop);
342 			if (ds) {
343 				sym->flags |= SYMBOL_WRITE;
344 				sym_calc_value(ds);
345 				newval.val = ds->curr.val;
346 			}
347 		}
348 		break;
349 	default:
350 		;
351 	}
352 
353 	sym->curr = newval;
354 	if (sym_is_choice(sym) && newval.tri == yes)
355 		sym->curr.val = sym_calc_choice(sym);
356 	sym_validate_range(sym);
357 
358 	if (memcmp(&oldval, &sym->curr, sizeof(oldval))) {
359 		sym_set_changed(sym);
360 		if (modules_sym == sym) {
361 			sym_set_all_changed();
362 			modules_val = modules_sym->curr.tri;
363 		}
364 	}
365 
366 	if (sym_is_choice(sym)) {
367 		struct symbol *choice_sym;
368 		int flags = sym->flags & (SYMBOL_CHANGED | SYMBOL_WRITE);
369 
370 		prop = sym_get_choice_prop(sym);
371 		expr_list_for_each_sym(prop->expr, e, choice_sym) {
372 			choice_sym->flags |= flags;
373 			if (flags & SYMBOL_CHANGED)
374 				sym_set_changed(choice_sym);
375 		}
376 	}
377 
378 	if (sym->flags & SYMBOL_AUTO)
379 		sym->flags &= ~SYMBOL_WRITE;
380 }
381 
382 void sym_clear_all_valid(void)
383 {
384 	struct symbol *sym;
385 	int i;
386 
387 	for_all_symbols(i, sym)
388 		sym->flags &= ~SYMBOL_VALID;
389 	sym_add_change_count(1);
390 	if (modules_sym)
391 		sym_calc_value(modules_sym);
392 }
393 
394 void sym_set_changed(struct symbol *sym)
395 {
396 	struct property *prop;
397 
398 	sym->flags |= SYMBOL_CHANGED;
399 	for (prop = sym->prop; prop; prop = prop->next) {
400 		if (prop->menu)
401 			prop->menu->flags |= MENU_CHANGED;
402 	}
403 }
404 
405 void sym_set_all_changed(void)
406 {
407 	struct symbol *sym;
408 	int i;
409 
410 	for_all_symbols(i, sym)
411 		sym_set_changed(sym);
412 }
413 
414 bool sym_tristate_within_range(struct symbol *sym, tristate val)
415 {
416 	int type = sym_get_type(sym);
417 
418 	if (sym->visible == no)
419 		return false;
420 
421 	if (type != S_BOOLEAN && type != S_TRISTATE)
422 		return false;
423 
424 	if (type == S_BOOLEAN && val == mod)
425 		return false;
426 	if (sym->visible <= sym->rev_dep.tri)
427 		return false;
428 	if (sym_is_choice_value(sym) && sym->visible == yes)
429 		return val == yes;
430 	return val >= sym->rev_dep.tri && val <= sym->visible;
431 }
432 
433 bool sym_set_tristate_value(struct symbol *sym, tristate val)
434 {
435 	tristate oldval = sym_get_tristate_value(sym);
436 
437 	if (oldval != val && !sym_tristate_within_range(sym, val))
438 		return false;
439 
440 	if (!(sym->flags & SYMBOL_DEF_USER)) {
441 		sym->flags |= SYMBOL_DEF_USER;
442 		sym_set_changed(sym);
443 	}
444 	/*
445 	 * setting a choice value also resets the new flag of the choice
446 	 * symbol and all other choice values.
447 	 */
448 	if (sym_is_choice_value(sym) && val == yes) {
449 		struct symbol *cs = prop_get_symbol(sym_get_choice_prop(sym));
450 		struct property *prop;
451 		struct expr *e;
452 
453 		cs->def[S_DEF_USER].val = sym;
454 		cs->flags |= SYMBOL_DEF_USER;
455 		prop = sym_get_choice_prop(cs);
456 		for (e = prop->expr; e; e = e->left.expr) {
457 			if (e->right.sym->visible != no)
458 				e->right.sym->flags |= SYMBOL_DEF_USER;
459 		}
460 	}
461 
462 	sym->def[S_DEF_USER].tri = val;
463 	if (oldval != val)
464 		sym_clear_all_valid();
465 
466 	return true;
467 }
468 
469 tristate sym_toggle_tristate_value(struct symbol *sym)
470 {
471 	tristate oldval, newval;
472 
473 	oldval = newval = sym_get_tristate_value(sym);
474 	do {
475 		switch (newval) {
476 		case no:
477 			newval = mod;
478 			break;
479 		case mod:
480 			newval = yes;
481 			break;
482 		case yes:
483 			newval = no;
484 			break;
485 		}
486 		if (sym_set_tristate_value(sym, newval))
487 			break;
488 	} while (oldval != newval);
489 	return newval;
490 }
491 
492 bool sym_string_valid(struct symbol *sym, const char *str)
493 {
494 	signed char ch;
495 
496 	switch (sym->type) {
497 	case S_STRING:
498 		return true;
499 	case S_INT:
500 		ch = *str++;
501 		if (ch == '-')
502 			ch = *str++;
503 		if (!isdigit(ch))
504 			return false;
505 		if (ch == '0' && *str != 0)
506 			return false;
507 		while ((ch = *str++)) {
508 			if (!isdigit(ch))
509 				return false;
510 		}
511 		return true;
512 	case S_HEX:
513 		if (str[0] == '0' && (str[1] == 'x' || str[1] == 'X'))
514 			str += 2;
515 		ch = *str++;
516 		do {
517 			if (!isxdigit(ch))
518 				return false;
519 		} while ((ch = *str++));
520 		return true;
521 	case S_BOOLEAN:
522 	case S_TRISTATE:
523 		switch (str[0]) {
524 		case 'y': case 'Y':
525 		case 'm': case 'M':
526 		case 'n': case 'N':
527 			return true;
528 		}
529 		return false;
530 	default:
531 		return false;
532 	}
533 }
534 
535 bool sym_string_within_range(struct symbol *sym, const char *str)
536 {
537 	struct property *prop;
538 	int val;
539 
540 	switch (sym->type) {
541 	case S_STRING:
542 		return sym_string_valid(sym, str);
543 	case S_INT:
544 		if (!sym_string_valid(sym, str))
545 			return false;
546 		prop = sym_get_range_prop(sym);
547 		if (!prop)
548 			return true;
549 		val = strtol(str, NULL, 10);
550 		return val >= sym_get_range_val(prop->expr->left.sym, 10) &&
551 		       val <= sym_get_range_val(prop->expr->right.sym, 10);
552 	case S_HEX:
553 		if (!sym_string_valid(sym, str))
554 			return false;
555 		prop = sym_get_range_prop(sym);
556 		if (!prop)
557 			return true;
558 		val = strtol(str, NULL, 16);
559 		return val >= sym_get_range_val(prop->expr->left.sym, 16) &&
560 		       val <= sym_get_range_val(prop->expr->right.sym, 16);
561 	case S_BOOLEAN:
562 	case S_TRISTATE:
563 		switch (str[0]) {
564 		case 'y': case 'Y':
565 			return sym_tristate_within_range(sym, yes);
566 		case 'm': case 'M':
567 			return sym_tristate_within_range(sym, mod);
568 		case 'n': case 'N':
569 			return sym_tristate_within_range(sym, no);
570 		}
571 		return false;
572 	default:
573 		return false;
574 	}
575 }
576 
577 bool sym_set_string_value(struct symbol *sym, const char *newval)
578 {
579 	const char *oldval;
580 	char *val;
581 	int size;
582 
583 	switch (sym->type) {
584 	case S_BOOLEAN:
585 	case S_TRISTATE:
586 		switch (newval[0]) {
587 		case 'y': case 'Y':
588 			return sym_set_tristate_value(sym, yes);
589 		case 'm': case 'M':
590 			return sym_set_tristate_value(sym, mod);
591 		case 'n': case 'N':
592 			return sym_set_tristate_value(sym, no);
593 		}
594 		return false;
595 	default:
596 		;
597 	}
598 
599 	if (!sym_string_within_range(sym, newval))
600 		return false;
601 
602 	if (!(sym->flags & SYMBOL_DEF_USER)) {
603 		sym->flags |= SYMBOL_DEF_USER;
604 		sym_set_changed(sym);
605 	}
606 
607 	oldval = sym->def[S_DEF_USER].val;
608 	size = strlen(newval) + 1;
609 	if (sym->type == S_HEX && (newval[0] != '0' || (newval[1] != 'x' && newval[1] != 'X'))) {
610 		size += 2;
611 		sym->def[S_DEF_USER].val = val = malloc(size);
612 		*val++ = '0';
613 		*val++ = 'x';
614 	} else if (!oldval || strcmp(oldval, newval))
615 		sym->def[S_DEF_USER].val = val = malloc(size);
616 	else
617 		return true;
618 
619 	strcpy(val, newval);
620 	free((void *)oldval);
621 	sym_clear_all_valid();
622 
623 	return true;
624 }
625 
626 const char *sym_get_string_value(struct symbol *sym)
627 {
628 	tristate val;
629 
630 	switch (sym->type) {
631 	case S_BOOLEAN:
632 	case S_TRISTATE:
633 		val = sym_get_tristate_value(sym);
634 		switch (val) {
635 		case no:
636 			return "n";
637 		case mod:
638 			return "m";
639 		case yes:
640 			return "y";
641 		}
642 		break;
643 	default:
644 		;
645 	}
646 	return (const char *)sym->curr.val;
647 }
648 
649 bool sym_is_changable(struct symbol *sym)
650 {
651 	return sym->visible > sym->rev_dep.tri;
652 }
653 
654 struct symbol *sym_lookup(const char *name, int flags)
655 {
656 	struct symbol *symbol;
657 	const char *ptr;
658 	char *new_name;
659 	int hash = 0;
660 
661 	if (name) {
662 		if (name[0] && !name[1]) {
663 			switch (name[0]) {
664 			case 'y': return &symbol_yes;
665 			case 'm': return &symbol_mod;
666 			case 'n': return &symbol_no;
667 			}
668 		}
669 		for (ptr = name; *ptr; ptr++)
670 			hash += *ptr;
671 		hash &= 0xff;
672 
673 		for (symbol = symbol_hash[hash]; symbol; symbol = symbol->next) {
674 			if (!strcmp(symbol->name, name) &&
675 			    (flags ? symbol->flags & flags
676 				   : !(symbol->flags & (SYMBOL_CONST|SYMBOL_CHOICE))))
677 				return symbol;
678 		}
679 		new_name = strdup(name);
680 	} else {
681 		new_name = NULL;
682 		hash = 256;
683 	}
684 
685 	symbol = malloc(sizeof(*symbol));
686 	memset(symbol, 0, sizeof(*symbol));
687 	symbol->name = new_name;
688 	symbol->type = S_UNKNOWN;
689 	symbol->flags |= flags;
690 
691 	symbol->next = symbol_hash[hash];
692 	symbol_hash[hash] = symbol;
693 
694 	return symbol;
695 }
696 
697 struct symbol *sym_find(const char *name)
698 {
699 	struct symbol *symbol = NULL;
700 	const char *ptr;
701 	int hash = 0;
702 
703 	if (!name)
704 		return NULL;
705 
706 	if (name[0] && !name[1]) {
707 		switch (name[0]) {
708 		case 'y': return &symbol_yes;
709 		case 'm': return &symbol_mod;
710 		case 'n': return &symbol_no;
711 		}
712 	}
713 	for (ptr = name; *ptr; ptr++)
714 		hash += *ptr;
715 	hash &= 0xff;
716 
717 	for (symbol = symbol_hash[hash]; symbol; symbol = symbol->next) {
718 		if (!strcmp(symbol->name, name) &&
719 		    !(symbol->flags & SYMBOL_CONST))
720 				break;
721 	}
722 
723 	return symbol;
724 }
725 
726 struct symbol **sym_re_search(const char *pattern)
727 {
728 	struct symbol *sym, **sym_arr = NULL;
729 	int i, cnt, size;
730 	regex_t re;
731 
732 	cnt = size = 0;
733 	/* Skip if empty */
734 	if (strlen(pattern) == 0)
735 		return NULL;
736 	if (regcomp(&re, pattern, REG_EXTENDED|REG_NOSUB|REG_ICASE))
737 		return NULL;
738 
739 	for_all_symbols(i, sym) {
740 		if (sym->flags & SYMBOL_CONST || !sym->name)
741 			continue;
742 		if (regexec(&re, sym->name, 0, NULL, 0))
743 			continue;
744 		if (cnt + 1 >= size) {
745 			void *tmp = sym_arr;
746 			size += 16;
747 			sym_arr = realloc(sym_arr, size * sizeof(struct symbol *));
748 			if (!sym_arr) {
749 				free(tmp);
750 				return NULL;
751 			}
752 		}
753 		sym_arr[cnt++] = sym;
754 	}
755 	if (sym_arr)
756 		sym_arr[cnt] = NULL;
757 	regfree(&re);
758 
759 	return sym_arr;
760 }
761 
762 
763 static struct symbol *sym_check_expr_deps(struct expr *e)
764 {
765 	struct symbol *sym;
766 
767 	if (!e)
768 		return NULL;
769 	switch (e->type) {
770 	case E_OR:
771 	case E_AND:
772 		sym = sym_check_expr_deps(e->left.expr);
773 		if (sym)
774 			return sym;
775 		return sym_check_expr_deps(e->right.expr);
776 	case E_NOT:
777 		return sym_check_expr_deps(e->left.expr);
778 	case E_EQUAL:
779 	case E_UNEQUAL:
780 		sym = sym_check_deps(e->left.sym);
781 		if (sym)
782 			return sym;
783 		return sym_check_deps(e->right.sym);
784 	case E_SYMBOL:
785 		return sym_check_deps(e->left.sym);
786 	default:
787 		break;
788 	}
789 	printf("Oops! How to check %d?\n", e->type);
790 	return NULL;
791 }
792 
793 /* return NULL when dependencies are OK */
794 static struct symbol *sym_check_sym_deps(struct symbol *sym)
795 {
796 	struct symbol *sym2;
797 	struct property *prop;
798 
799 	sym2 = sym_check_expr_deps(sym->rev_dep.expr);
800 	if (sym2)
801 		return sym2;
802 
803 	for (prop = sym->prop; prop; prop = prop->next) {
804 		if (prop->type == P_CHOICE || prop->type == P_SELECT)
805 			continue;
806 		sym2 = sym_check_expr_deps(prop->visible.expr);
807 		if (sym2)
808 			break;
809 		if (prop->type != P_DEFAULT || sym_is_choice(sym))
810 			continue;
811 		sym2 = sym_check_expr_deps(prop->expr);
812 		if (sym2)
813 			break;
814 	}
815 
816 	return sym2;
817 }
818 
819 static struct symbol *sym_check_choice_deps(struct symbol *choice)
820 {
821 	struct symbol *sym, *sym2;
822 	struct property *prop;
823 	struct expr *e;
824 
825 	prop = sym_get_choice_prop(choice);
826 	expr_list_for_each_sym(prop->expr, e, sym)
827 		sym->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
828 
829 	choice->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
830 	sym2 = sym_check_sym_deps(choice);
831 	choice->flags &= ~SYMBOL_CHECK;
832 	if (sym2)
833 		goto out;
834 
835 	expr_list_for_each_sym(prop->expr, e, sym) {
836 		sym2 = sym_check_sym_deps(sym);
837 		if (sym2) {
838 			fprintf(stderr, " -> %s", sym->name);
839 			break;
840 		}
841 	}
842 out:
843 	expr_list_for_each_sym(prop->expr, e, sym)
844 		sym->flags &= ~SYMBOL_CHECK;
845 
846 	if (sym2 && sym_is_choice_value(sym2) &&
847 	    prop_get_symbol(sym_get_choice_prop(sym2)) == choice)
848 		sym2 = choice;
849 
850 	return sym2;
851 }
852 
853 struct symbol *sym_check_deps(struct symbol *sym)
854 {
855 	struct symbol *sym2;
856 	struct property *prop;
857 
858 	if (sym->flags & SYMBOL_CHECK) {
859 		fprintf(stderr, "%s:%d:error: found recursive dependency: %s",
860 		        sym->prop->file->name, sym->prop->lineno,
861 			sym->name ? sym->name : "<choice>");
862 		return sym;
863 	}
864 	if (sym->flags & SYMBOL_CHECKED)
865 		return NULL;
866 
867 	if (sym_is_choice_value(sym)) {
868 		/* for choice groups start the check with main choice symbol */
869 		prop = sym_get_choice_prop(sym);
870 		sym2 = sym_check_deps(prop_get_symbol(prop));
871 	} else if (sym_is_choice(sym)) {
872 		sym2 = sym_check_choice_deps(sym);
873 	} else {
874 		sym->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
875 		sym2 = sym_check_sym_deps(sym);
876 		sym->flags &= ~SYMBOL_CHECK;
877 	}
878 
879 	if (sym2) {
880 		fprintf(stderr, " -> %s", sym->name ? sym->name : "<choice>");
881 		if (sym2 == sym) {
882 			fprintf(stderr, "\n");
883 			zconfnerrs++;
884 			sym2 = NULL;
885 		}
886 	}
887 
888 	return sym2;
889 }
890 
891 struct property *prop_alloc(enum prop_type type, struct symbol *sym)
892 {
893 	struct property *prop;
894 	struct property **propp;
895 
896 	prop = malloc(sizeof(*prop));
897 	memset(prop, 0, sizeof(*prop));
898 	prop->type = type;
899 	prop->sym = sym;
900 	prop->file = current_file;
901 	prop->lineno = zconf_lineno();
902 
903 	/* append property to the prop list of symbol */
904 	if (sym) {
905 		for (propp = &sym->prop; *propp; propp = &(*propp)->next)
906 			;
907 		*propp = prop;
908 	}
909 
910 	return prop;
911 }
912 
913 struct symbol *prop_get_symbol(struct property *prop)
914 {
915 	if (prop->expr && (prop->expr->type == E_SYMBOL ||
916 			   prop->expr->type == E_LIST))
917 		return prop->expr->left.sym;
918 	return NULL;
919 }
920 
921 const char *prop_get_type_name(enum prop_type type)
922 {
923 	switch (type) {
924 	case P_PROMPT:
925 		return "prompt";
926 	case P_ENV:
927 		return "env";
928 	case P_COMMENT:
929 		return "comment";
930 	case P_MENU:
931 		return "menu";
932 	case P_DEFAULT:
933 		return "default";
934 	case P_CHOICE:
935 		return "choice";
936 	case P_SELECT:
937 		return "select";
938 	case P_RANGE:
939 		return "range";
940 	case P_UNKNOWN:
941 		break;
942 	}
943 	return "unknown";
944 }
945 
946 void prop_add_env(const char *env)
947 {
948 	struct symbol *sym, *sym2;
949 	struct property *prop;
950 	char *p;
951 
952 	sym = current_entry->sym;
953 	sym->flags |= SYMBOL_AUTO;
954 	for_all_properties(sym, prop, P_ENV) {
955 		sym2 = prop_get_symbol(prop);
956 		if (strcmp(sym2->name, env))
957 			menu_warn(current_entry, "redefining environment symbol from %s",
958 				  sym2->name);
959 		return;
960 	}
961 
962 	prop = prop_alloc(P_ENV, sym);
963 	prop->expr = expr_alloc_symbol(sym_lookup(env, SYMBOL_CONST));
964 
965 	sym_env_list = expr_alloc_one(E_LIST, sym_env_list);
966 	sym_env_list->right.sym = sym;
967 
968 	p = getenv(env);
969 	if (p)
970 		sym_add_default(sym, p);
971 	else
972 		menu_warn(current_entry, "environment variable %s undefined", env);
973 }
974