xref: /linux/scripts/kconfig/symbol.c (revision 2504075d383fcefd746dac42a0cd1c3bdc006bd1) 
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 static 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 static 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 	/* defaulting to "yes" if no explicit "depends on" are given */
209 	tri = yes;
210 	if (sym->dir_dep.expr)
211 		tri = expr_calc_value(sym->dir_dep.expr);
212 	if (tri == mod)
213 		tri = yes;
214 	if (sym->dir_dep.tri != tri) {
215 		sym->dir_dep.tri = tri;
216 		sym_set_changed(sym);
217 	}
218 	tri = no;
219 	if (sym->rev_dep.expr)
220 		tri = expr_calc_value(sym->rev_dep.expr);
221 	if (tri == mod && sym_get_type(sym) == S_BOOLEAN)
222 		tri = yes;
223 	if (sym->rev_dep.tri != tri) {
224 		sym->rev_dep.tri = tri;
225 		sym_set_changed(sym);
226 	}
227 }
228 
229 /*
230  * Find the default symbol for a choice.
231  * First try the default values for the choice symbol
232  * Next locate the first visible choice value
233  * Return NULL if none was found
234  */
235 struct symbol *sym_choice_default(struct symbol *sym)
236 {
237 	struct symbol *def_sym;
238 	struct property *prop;
239 	struct expr *e;
240 
241 	/* any of the defaults visible? */
242 	for_all_defaults(sym, prop) {
243 		prop->visible.tri = expr_calc_value(prop->visible.expr);
244 		if (prop->visible.tri == no)
245 			continue;
246 		def_sym = prop_get_symbol(prop);
247 		if (def_sym->visible != no)
248 			return def_sym;
249 	}
250 
251 	/* just get the first visible value */
252 	prop = sym_get_choice_prop(sym);
253 	expr_list_for_each_sym(prop->expr, e, def_sym)
254 		if (def_sym->visible != no)
255 			return def_sym;
256 
257 	/* failed to locate any defaults */
258 	return NULL;
259 }
260 
261 static struct symbol *sym_calc_choice(struct symbol *sym)
262 {
263 	struct symbol *def_sym;
264 	struct property *prop;
265 	struct expr *e;
266 
267 	/* first calculate all choice values' visibilities */
268 	prop = sym_get_choice_prop(sym);
269 	expr_list_for_each_sym(prop->expr, e, def_sym)
270 		sym_calc_visibility(def_sym);
271 
272 	/* is the user choice visible? */
273 	def_sym = sym->def[S_DEF_USER].val;
274 	if (def_sym && def_sym->visible != no)
275 		return def_sym;
276 
277 	def_sym = sym_choice_default(sym);
278 
279 	if (def_sym == NULL)
280 		/* no choice? reset tristate value */
281 		sym->curr.tri = no;
282 
283 	return def_sym;
284 }
285 
286 void sym_calc_value(struct symbol *sym)
287 {
288 	struct symbol_value newval, oldval;
289 	struct property *prop;
290 	struct expr *e;
291 
292 	if (!sym)
293 		return;
294 
295 	if (sym->flags & SYMBOL_VALID)
296 		return;
297 	sym->flags |= SYMBOL_VALID;
298 
299 	oldval = sym->curr;
300 
301 	switch (sym->type) {
302 	case S_INT:
303 	case S_HEX:
304 	case S_STRING:
305 		newval = symbol_empty.curr;
306 		break;
307 	case S_BOOLEAN:
308 	case S_TRISTATE:
309 		newval = symbol_no.curr;
310 		break;
311 	default:
312 		sym->curr.val = sym->name;
313 		sym->curr.tri = no;
314 		return;
315 	}
316 	if (!sym_is_choice_value(sym))
317 		sym->flags &= ~SYMBOL_WRITE;
318 
319 	sym_calc_visibility(sym);
320 
321 	/* set default if recursively called */
322 	sym->curr = newval;
323 
324 	switch (sym_get_type(sym)) {
325 	case S_BOOLEAN:
326 	case S_TRISTATE:
327 		if (sym_is_choice_value(sym) && sym->visible == yes) {
328 			prop = sym_get_choice_prop(sym);
329 			newval.tri = (prop_get_symbol(prop)->curr.val == sym) ? yes : no;
330 		} else {
331 			if (sym->visible != no) {
332 				/* if the symbol is visible use the user value
333 				 * if available, otherwise try the default value
334 				 */
335 				sym->flags |= SYMBOL_WRITE;
336 				if (sym_has_value(sym)) {
337 					newval.tri = EXPR_AND(sym->def[S_DEF_USER].tri,
338 							      sym->visible);
339 					goto calc_newval;
340 				}
341 			}
342 			if (sym->rev_dep.tri != no)
343 				sym->flags |= SYMBOL_WRITE;
344 			if (!sym_is_choice(sym)) {
345 				prop = sym_get_default_prop(sym);
346 				if (prop) {
347 					sym->flags |= SYMBOL_WRITE;
348 					newval.tri = EXPR_AND(expr_calc_value(prop->expr),
349 							      prop->visible.tri);
350 				}
351 			}
352 		calc_newval:
353 			if (sym->dir_dep.tri == no && sym->rev_dep.tri != no) {
354 				fprintf(stderr, "warning: (");
355 				expr_fprint(sym->rev_dep.expr, stderr);
356 				fprintf(stderr, ") selects %s which has unmet direct dependencies (",
357 					sym->name);
358 				expr_fprint(sym->dir_dep.expr, stderr);
359 				fprintf(stderr, ")\n");
360 			}
361 			newval.tri = EXPR_OR(newval.tri, sym->rev_dep.tri);
362 		}
363 		if (newval.tri == mod && sym_get_type(sym) == S_BOOLEAN)
364 			newval.tri = yes;
365 		break;
366 	case S_STRING:
367 	case S_HEX:
368 	case S_INT:
369 		if (sym->visible != no) {
370 			sym->flags |= SYMBOL_WRITE;
371 			if (sym_has_value(sym)) {
372 				newval.val = sym->def[S_DEF_USER].val;
373 				break;
374 			}
375 		}
376 		prop = sym_get_default_prop(sym);
377 		if (prop) {
378 			struct symbol *ds = prop_get_symbol(prop);
379 			if (ds) {
380 				sym->flags |= SYMBOL_WRITE;
381 				sym_calc_value(ds);
382 				newval.val = ds->curr.val;
383 			}
384 		}
385 		break;
386 	default:
387 		;
388 	}
389 
390 	sym->curr = newval;
391 	if (sym_is_choice(sym) && newval.tri == yes)
392 		sym->curr.val = sym_calc_choice(sym);
393 	sym_validate_range(sym);
394 
395 	if (memcmp(&oldval, &sym->curr, sizeof(oldval))) {
396 		sym_set_changed(sym);
397 		if (modules_sym == sym) {
398 			sym_set_all_changed();
399 			modules_val = modules_sym->curr.tri;
400 		}
401 	}
402 
403 	if (sym_is_choice(sym)) {
404 		struct symbol *choice_sym;
405 
406 		prop = sym_get_choice_prop(sym);
407 		expr_list_for_each_sym(prop->expr, e, choice_sym) {
408 			if ((sym->flags & SYMBOL_WRITE) &&
409 			    choice_sym->visible != no)
410 				choice_sym->flags |= SYMBOL_WRITE;
411 			if (sym->flags & SYMBOL_CHANGED)
412 				sym_set_changed(choice_sym);
413 		}
414 	}
415 
416 	if (sym->flags & SYMBOL_AUTO)
417 		sym->flags &= ~SYMBOL_WRITE;
418 }
419 
420 void sym_clear_all_valid(void)
421 {
422 	struct symbol *sym;
423 	int i;
424 
425 	for_all_symbols(i, sym)
426 		sym->flags &= ~SYMBOL_VALID;
427 	sym_add_change_count(1);
428 	if (modules_sym)
429 		sym_calc_value(modules_sym);
430 }
431 
432 void sym_set_changed(struct symbol *sym)
433 {
434 	struct property *prop;
435 
436 	sym->flags |= SYMBOL_CHANGED;
437 	for (prop = sym->prop; prop; prop = prop->next) {
438 		if (prop->menu)
439 			prop->menu->flags |= MENU_CHANGED;
440 	}
441 }
442 
443 void sym_set_all_changed(void)
444 {
445 	struct symbol *sym;
446 	int i;
447 
448 	for_all_symbols(i, sym)
449 		sym_set_changed(sym);
450 }
451 
452 bool sym_tristate_within_range(struct symbol *sym, tristate val)
453 {
454 	int type = sym_get_type(sym);
455 
456 	if (sym->visible == no)
457 		return false;
458 
459 	if (type != S_BOOLEAN && type != S_TRISTATE)
460 		return false;
461 
462 	if (type == S_BOOLEAN && val == mod)
463 		return false;
464 	if (sym->visible <= sym->rev_dep.tri)
465 		return false;
466 	if (sym_is_choice_value(sym) && sym->visible == yes)
467 		return val == yes;
468 	return val >= sym->rev_dep.tri && val <= sym->visible;
469 }
470 
471 bool sym_set_tristate_value(struct symbol *sym, tristate val)
472 {
473 	tristate oldval = sym_get_tristate_value(sym);
474 
475 	if (oldval != val && !sym_tristate_within_range(sym, val))
476 		return false;
477 
478 	if (!(sym->flags & SYMBOL_DEF_USER)) {
479 		sym->flags |= SYMBOL_DEF_USER;
480 		sym_set_changed(sym);
481 	}
482 	/*
483 	 * setting a choice value also resets the new flag of the choice
484 	 * symbol and all other choice values.
485 	 */
486 	if (sym_is_choice_value(sym) && val == yes) {
487 		struct symbol *cs = prop_get_symbol(sym_get_choice_prop(sym));
488 		struct property *prop;
489 		struct expr *e;
490 
491 		cs->def[S_DEF_USER].val = sym;
492 		cs->flags |= SYMBOL_DEF_USER;
493 		prop = sym_get_choice_prop(cs);
494 		for (e = prop->expr; e; e = e->left.expr) {
495 			if (e->right.sym->visible != no)
496 				e->right.sym->flags |= SYMBOL_DEF_USER;
497 		}
498 	}
499 
500 	sym->def[S_DEF_USER].tri = val;
501 	if (oldval != val)
502 		sym_clear_all_valid();
503 
504 	return true;
505 }
506 
507 tristate sym_toggle_tristate_value(struct symbol *sym)
508 {
509 	tristate oldval, newval;
510 
511 	oldval = newval = sym_get_tristate_value(sym);
512 	do {
513 		switch (newval) {
514 		case no:
515 			newval = mod;
516 			break;
517 		case mod:
518 			newval = yes;
519 			break;
520 		case yes:
521 			newval = no;
522 			break;
523 		}
524 		if (sym_set_tristate_value(sym, newval))
525 			break;
526 	} while (oldval != newval);
527 	return newval;
528 }
529 
530 bool sym_string_valid(struct symbol *sym, const char *str)
531 {
532 	signed char ch;
533 
534 	switch (sym->type) {
535 	case S_STRING:
536 		return true;
537 	case S_INT:
538 		ch = *str++;
539 		if (ch == '-')
540 			ch = *str++;
541 		if (!isdigit(ch))
542 			return false;
543 		if (ch == '0' && *str != 0)
544 			return false;
545 		while ((ch = *str++)) {
546 			if (!isdigit(ch))
547 				return false;
548 		}
549 		return true;
550 	case S_HEX:
551 		if (str[0] == '0' && (str[1] == 'x' || str[1] == 'X'))
552 			str += 2;
553 		ch = *str++;
554 		do {
555 			if (!isxdigit(ch))
556 				return false;
557 		} while ((ch = *str++));
558 		return true;
559 	case S_BOOLEAN:
560 	case S_TRISTATE:
561 		switch (str[0]) {
562 		case 'y': case 'Y':
563 		case 'm': case 'M':
564 		case 'n': case 'N':
565 			return true;
566 		}
567 		return false;
568 	default:
569 		return false;
570 	}
571 }
572 
573 bool sym_string_within_range(struct symbol *sym, const char *str)
574 {
575 	struct property *prop;
576 	int val;
577 
578 	switch (sym->type) {
579 	case S_STRING:
580 		return sym_string_valid(sym, str);
581 	case S_INT:
582 		if (!sym_string_valid(sym, str))
583 			return false;
584 		prop = sym_get_range_prop(sym);
585 		if (!prop)
586 			return true;
587 		val = strtol(str, NULL, 10);
588 		return val >= sym_get_range_val(prop->expr->left.sym, 10) &&
589 		       val <= sym_get_range_val(prop->expr->right.sym, 10);
590 	case S_HEX:
591 		if (!sym_string_valid(sym, str))
592 			return false;
593 		prop = sym_get_range_prop(sym);
594 		if (!prop)
595 			return true;
596 		val = strtol(str, NULL, 16);
597 		return val >= sym_get_range_val(prop->expr->left.sym, 16) &&
598 		       val <= sym_get_range_val(prop->expr->right.sym, 16);
599 	case S_BOOLEAN:
600 	case S_TRISTATE:
601 		switch (str[0]) {
602 		case 'y': case 'Y':
603 			return sym_tristate_within_range(sym, yes);
604 		case 'm': case 'M':
605 			return sym_tristate_within_range(sym, mod);
606 		case 'n': case 'N':
607 			return sym_tristate_within_range(sym, no);
608 		}
609 		return false;
610 	default:
611 		return false;
612 	}
613 }
614 
615 bool sym_set_string_value(struct symbol *sym, const char *newval)
616 {
617 	const char *oldval;
618 	char *val;
619 	int size;
620 
621 	switch (sym->type) {
622 	case S_BOOLEAN:
623 	case S_TRISTATE:
624 		switch (newval[0]) {
625 		case 'y': case 'Y':
626 			return sym_set_tristate_value(sym, yes);
627 		case 'm': case 'M':
628 			return sym_set_tristate_value(sym, mod);
629 		case 'n': case 'N':
630 			return sym_set_tristate_value(sym, no);
631 		}
632 		return false;
633 	default:
634 		;
635 	}
636 
637 	if (!sym_string_within_range(sym, newval))
638 		return false;
639 
640 	if (!(sym->flags & SYMBOL_DEF_USER)) {
641 		sym->flags |= SYMBOL_DEF_USER;
642 		sym_set_changed(sym);
643 	}
644 
645 	oldval = sym->def[S_DEF_USER].val;
646 	size = strlen(newval) + 1;
647 	if (sym->type == S_HEX && (newval[0] != '0' || (newval[1] != 'x' && newval[1] != 'X'))) {
648 		size += 2;
649 		sym->def[S_DEF_USER].val = val = malloc(size);
650 		*val++ = '0';
651 		*val++ = 'x';
652 	} else if (!oldval || strcmp(oldval, newval))
653 		sym->def[S_DEF_USER].val = val = malloc(size);
654 	else
655 		return true;
656 
657 	strcpy(val, newval);
658 	free((void *)oldval);
659 	sym_clear_all_valid();
660 
661 	return true;
662 }
663 
664 /*
665  * Find the default value associated to a symbol.
666  * For tristate symbol handle the modules=n case
667  * in which case "m" becomes "y".
668  * If the symbol does not have any default then fallback
669  * to the fixed default values.
670  */
671 const char *sym_get_string_default(struct symbol *sym)
672 {
673 	struct property *prop;
674 	struct symbol *ds;
675 	const char *str;
676 	tristate val;
677 
678 	sym_calc_visibility(sym);
679 	sym_calc_value(modules_sym);
680 	val = symbol_no.curr.tri;
681 	str = symbol_empty.curr.val;
682 
683 	/* If symbol has a default value look it up */
684 	prop = sym_get_default_prop(sym);
685 	if (prop != NULL) {
686 		switch (sym->type) {
687 		case S_BOOLEAN:
688 		case S_TRISTATE:
689 			/* The visibility imay limit the value from yes => mod */
690 			val = EXPR_AND(expr_calc_value(prop->expr), prop->visible.tri);
691 			break;
692 		default:
693 			/*
694 			 * The following fails to handle the situation
695 			 * where a default value is further limited by
696 			 * the valid range.
697 			 */
698 			ds = prop_get_symbol(prop);
699 			if (ds != NULL) {
700 				sym_calc_value(ds);
701 				str = (const char *)ds->curr.val;
702 			}
703 		}
704 	}
705 
706 	/* Handle select statements */
707 	val = EXPR_OR(val, sym->rev_dep.tri);
708 
709 	/* transpose mod to yes if modules are not enabled */
710 	if (val == mod)
711 		if (!sym_is_choice_value(sym) && modules_sym->curr.tri == no)
712 			val = yes;
713 
714 	/* transpose mod to yes if type is bool */
715 	if (sym->type == S_BOOLEAN && val == mod)
716 		val = yes;
717 
718 	switch (sym->type) {
719 	case S_BOOLEAN:
720 	case S_TRISTATE:
721 		switch (val) {
722 		case no: return "n";
723 		case mod: return "m";
724 		case yes: return "y";
725 		}
726 	case S_INT:
727 	case S_HEX:
728 		return str;
729 	case S_STRING:
730 		return str;
731 	case S_OTHER:
732 	case S_UNKNOWN:
733 		break;
734 	}
735 	return "";
736 }
737 
738 const char *sym_get_string_value(struct symbol *sym)
739 {
740 	tristate val;
741 
742 	switch (sym->type) {
743 	case S_BOOLEAN:
744 	case S_TRISTATE:
745 		val = sym_get_tristate_value(sym);
746 		switch (val) {
747 		case no:
748 			return "n";
749 		case mod:
750 			return "m";
751 		case yes:
752 			return "y";
753 		}
754 		break;
755 	default:
756 		;
757 	}
758 	return (const char *)sym->curr.val;
759 }
760 
761 bool sym_is_changable(struct symbol *sym)
762 {
763 	return sym->visible > sym->rev_dep.tri;
764 }
765 
766 static unsigned strhash(const char *s)
767 {
768 	/* fnv32 hash */
769 	unsigned hash = 2166136261U;
770 	for (; *s; s++)
771 		hash = (hash ^ *s) * 0x01000193;
772 	return hash;
773 }
774 
775 struct symbol *sym_lookup(const char *name, int flags)
776 {
777 	struct symbol *symbol;
778 	char *new_name;
779 	int hash;
780 
781 	if (name) {
782 		if (name[0] && !name[1]) {
783 			switch (name[0]) {
784 			case 'y': return &symbol_yes;
785 			case 'm': return &symbol_mod;
786 			case 'n': return &symbol_no;
787 			}
788 		}
789 		hash = strhash(name) % SYMBOL_HASHSIZE;
790 
791 		for (symbol = symbol_hash[hash]; symbol; symbol = symbol->next) {
792 			if (symbol->name &&
793 			    !strcmp(symbol->name, name) &&
794 			    (flags ? symbol->flags & flags
795 				   : !(symbol->flags & (SYMBOL_CONST|SYMBOL_CHOICE))))
796 				return symbol;
797 		}
798 		new_name = strdup(name);
799 	} else {
800 		new_name = NULL;
801 		hash = 0;
802 	}
803 
804 	symbol = malloc(sizeof(*symbol));
805 	memset(symbol, 0, sizeof(*symbol));
806 	symbol->name = new_name;
807 	symbol->type = S_UNKNOWN;
808 	symbol->flags |= flags;
809 
810 	symbol->next = symbol_hash[hash];
811 	symbol_hash[hash] = symbol;
812 
813 	return symbol;
814 }
815 
816 struct symbol *sym_find(const char *name)
817 {
818 	struct symbol *symbol = NULL;
819 	int hash = 0;
820 
821 	if (!name)
822 		return NULL;
823 
824 	if (name[0] && !name[1]) {
825 		switch (name[0]) {
826 		case 'y': return &symbol_yes;
827 		case 'm': return &symbol_mod;
828 		case 'n': return &symbol_no;
829 		}
830 	}
831 	hash = strhash(name) % SYMBOL_HASHSIZE;
832 
833 	for (symbol = symbol_hash[hash]; symbol; symbol = symbol->next) {
834 		if (symbol->name &&
835 		    !strcmp(symbol->name, name) &&
836 		    !(symbol->flags & SYMBOL_CONST))
837 				break;
838 	}
839 
840 	return symbol;
841 }
842 
843 /*
844  * Expand symbol's names embedded in the string given in argument. Symbols'
845  * name to be expanded shall be prefixed by a '$'. Unknown symbol expands to
846  * the empty string.
847  */
848 const char *sym_expand_string_value(const char *in)
849 {
850 	const char *src;
851 	char *res;
852 	size_t reslen;
853 
854 	reslen = strlen(in) + 1;
855 	res = malloc(reslen);
856 	res[0] = '\0';
857 
858 	while ((src = strchr(in, '$'))) {
859 		char *p, name[SYMBOL_MAXLENGTH];
860 		const char *symval = "";
861 		struct symbol *sym;
862 		size_t newlen;
863 
864 		strncat(res, in, src - in);
865 		src++;
866 
867 		p = name;
868 		while (isalnum(*src) || *src == '_')
869 			*p++ = *src++;
870 		*p = '\0';
871 
872 		sym = sym_find(name);
873 		if (sym != NULL) {
874 			sym_calc_value(sym);
875 			symval = sym_get_string_value(sym);
876 		}
877 
878 		newlen = strlen(res) + strlen(symval) + strlen(src);
879 		if (newlen > reslen) {
880 			reslen = newlen;
881 			res = realloc(res, reslen);
882 		}
883 
884 		strcat(res, symval);
885 		in = src;
886 	}
887 	strcat(res, in);
888 
889 	return res;
890 }
891 
892 struct symbol **sym_re_search(const char *pattern)
893 {
894 	struct symbol *sym, **sym_arr = NULL;
895 	int i, cnt, size;
896 	regex_t re;
897 
898 	cnt = size = 0;
899 	/* Skip if empty */
900 	if (strlen(pattern) == 0)
901 		return NULL;
902 	if (regcomp(&re, pattern, REG_EXTENDED|REG_NOSUB|REG_ICASE))
903 		return NULL;
904 
905 	for_all_symbols(i, sym) {
906 		if (sym->flags & SYMBOL_CONST || !sym->name)
907 			continue;
908 		if (regexec(&re, sym->name, 0, NULL, 0))
909 			continue;
910 		if (cnt + 1 >= size) {
911 			void *tmp = sym_arr;
912 			size += 16;
913 			sym_arr = realloc(sym_arr, size * sizeof(struct symbol *));
914 			if (!sym_arr) {
915 				free(tmp);
916 				return NULL;
917 			}
918 		}
919 		sym_calc_value(sym);
920 		sym_arr[cnt++] = sym;
921 	}
922 	if (sym_arr)
923 		sym_arr[cnt] = NULL;
924 	regfree(&re);
925 
926 	return sym_arr;
927 }
928 
929 /*
930  * When we check for recursive dependencies we use a stack to save
931  * current state so we can print out relevant info to user.
932  * The entries are located on the call stack so no need to free memory.
933  * Note inser() remove() must always match to properly clear the stack.
934  */
935 static struct dep_stack {
936 	struct dep_stack *prev, *next;
937 	struct symbol *sym;
938 	struct property *prop;
939 	struct expr *expr;
940 } *check_top;
941 
942 static void dep_stack_insert(struct dep_stack *stack, struct symbol *sym)
943 {
944 	memset(stack, 0, sizeof(*stack));
945 	if (check_top)
946 		check_top->next = stack;
947 	stack->prev = check_top;
948 	stack->sym = sym;
949 	check_top = stack;
950 }
951 
952 static void dep_stack_remove(void)
953 {
954 	check_top = check_top->prev;
955 	if (check_top)
956 		check_top->next = NULL;
957 }
958 
959 /*
960  * Called when we have detected a recursive dependency.
961  * check_top point to the top of the stact so we use
962  * the ->prev pointer to locate the bottom of the stack.
963  */
964 static void sym_check_print_recursive(struct symbol *last_sym)
965 {
966 	struct dep_stack *stack;
967 	struct symbol *sym, *next_sym;
968 	struct menu *menu = NULL;
969 	struct property *prop;
970 	struct dep_stack cv_stack;
971 
972 	if (sym_is_choice_value(last_sym)) {
973 		dep_stack_insert(&cv_stack, last_sym);
974 		last_sym = prop_get_symbol(sym_get_choice_prop(last_sym));
975 	}
976 
977 	for (stack = check_top; stack != NULL; stack = stack->prev)
978 		if (stack->sym == last_sym)
979 			break;
980 	if (!stack) {
981 		fprintf(stderr, "unexpected recursive dependency error\n");
982 		return;
983 	}
984 
985 	for (; stack; stack = stack->next) {
986 		sym = stack->sym;
987 		next_sym = stack->next ? stack->next->sym : last_sym;
988 		prop = stack->prop;
989 		if (prop == NULL)
990 			prop = stack->sym->prop;
991 
992 		/* for choice values find the menu entry (used below) */
993 		if (sym_is_choice(sym) || sym_is_choice_value(sym)) {
994 			for (prop = sym->prop; prop; prop = prop->next) {
995 				menu = prop->menu;
996 				if (prop->menu)
997 					break;
998 			}
999 		}
1000 		if (stack->sym == last_sym)
1001 			fprintf(stderr, "%s:%d:error: recursive dependency detected!\n",
1002 				prop->file->name, prop->lineno);
1003 		if (stack->expr) {
1004 			fprintf(stderr, "%s:%d:\tsymbol %s %s value contains %s\n",
1005 				prop->file->name, prop->lineno,
1006 				sym->name ? sym->name : "<choice>",
1007 				prop_get_type_name(prop->type),
1008 				next_sym->name ? next_sym->name : "<choice>");
1009 		} else if (stack->prop) {
1010 			fprintf(stderr, "%s:%d:\tsymbol %s depends on %s\n",
1011 				prop->file->name, prop->lineno,
1012 				sym->name ? sym->name : "<choice>",
1013 				next_sym->name ? next_sym->name : "<choice>");
1014 		} else if (sym_is_choice(sym)) {
1015 			fprintf(stderr, "%s:%d:\tchoice %s contains symbol %s\n",
1016 				menu->file->name, menu->lineno,
1017 				sym->name ? sym->name : "<choice>",
1018 				next_sym->name ? next_sym->name : "<choice>");
1019 		} else if (sym_is_choice_value(sym)) {
1020 			fprintf(stderr, "%s:%d:\tsymbol %s is part of choice %s\n",
1021 				menu->file->name, menu->lineno,
1022 				sym->name ? sym->name : "<choice>",
1023 				next_sym->name ? next_sym->name : "<choice>");
1024 		} else {
1025 			fprintf(stderr, "%s:%d:\tsymbol %s is selected by %s\n",
1026 				prop->file->name, prop->lineno,
1027 				sym->name ? sym->name : "<choice>",
1028 				next_sym->name ? next_sym->name : "<choice>");
1029 		}
1030 	}
1031 
1032 	if (check_top == &cv_stack)
1033 		dep_stack_remove();
1034 }
1035 
1036 static struct symbol *sym_check_expr_deps(struct expr *e)
1037 {
1038 	struct symbol *sym;
1039 
1040 	if (!e)
1041 		return NULL;
1042 	switch (e->type) {
1043 	case E_OR:
1044 	case E_AND:
1045 		sym = sym_check_expr_deps(e->left.expr);
1046 		if (sym)
1047 			return sym;
1048 		return sym_check_expr_deps(e->right.expr);
1049 	case E_NOT:
1050 		return sym_check_expr_deps(e->left.expr);
1051 	case E_EQUAL:
1052 	case E_UNEQUAL:
1053 		sym = sym_check_deps(e->left.sym);
1054 		if (sym)
1055 			return sym;
1056 		return sym_check_deps(e->right.sym);
1057 	case E_SYMBOL:
1058 		return sym_check_deps(e->left.sym);
1059 	default:
1060 		break;
1061 	}
1062 	printf("Oops! How to check %d?\n", e->type);
1063 	return NULL;
1064 }
1065 
1066 /* return NULL when dependencies are OK */
1067 static struct symbol *sym_check_sym_deps(struct symbol *sym)
1068 {
1069 	struct symbol *sym2;
1070 	struct property *prop;
1071 	struct dep_stack stack;
1072 
1073 	dep_stack_insert(&stack, sym);
1074 
1075 	sym2 = sym_check_expr_deps(sym->rev_dep.expr);
1076 	if (sym2)
1077 		goto out;
1078 
1079 	for (prop = sym->prop; prop; prop = prop->next) {
1080 		if (prop->type == P_CHOICE || prop->type == P_SELECT)
1081 			continue;
1082 		stack.prop = prop;
1083 		sym2 = sym_check_expr_deps(prop->visible.expr);
1084 		if (sym2)
1085 			break;
1086 		if (prop->type != P_DEFAULT || sym_is_choice(sym))
1087 			continue;
1088 		stack.expr = prop->expr;
1089 		sym2 = sym_check_expr_deps(prop->expr);
1090 		if (sym2)
1091 			break;
1092 		stack.expr = NULL;
1093 	}
1094 
1095 out:
1096 	dep_stack_remove();
1097 
1098 	return sym2;
1099 }
1100 
1101 static struct symbol *sym_check_choice_deps(struct symbol *choice)
1102 {
1103 	struct symbol *sym, *sym2;
1104 	struct property *prop;
1105 	struct expr *e;
1106 	struct dep_stack stack;
1107 
1108 	dep_stack_insert(&stack, choice);
1109 
1110 	prop = sym_get_choice_prop(choice);
1111 	expr_list_for_each_sym(prop->expr, e, sym)
1112 		sym->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1113 
1114 	choice->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1115 	sym2 = sym_check_sym_deps(choice);
1116 	choice->flags &= ~SYMBOL_CHECK;
1117 	if (sym2)
1118 		goto out;
1119 
1120 	expr_list_for_each_sym(prop->expr, e, sym) {
1121 		sym2 = sym_check_sym_deps(sym);
1122 		if (sym2)
1123 			break;
1124 	}
1125 out:
1126 	expr_list_for_each_sym(prop->expr, e, sym)
1127 		sym->flags &= ~SYMBOL_CHECK;
1128 
1129 	if (sym2 && sym_is_choice_value(sym2) &&
1130 	    prop_get_symbol(sym_get_choice_prop(sym2)) == choice)
1131 		sym2 = choice;
1132 
1133 	dep_stack_remove();
1134 
1135 	return sym2;
1136 }
1137 
1138 struct symbol *sym_check_deps(struct symbol *sym)
1139 {
1140 	struct symbol *sym2;
1141 	struct property *prop;
1142 
1143 	if (sym->flags & SYMBOL_CHECK) {
1144 		sym_check_print_recursive(sym);
1145 		return sym;
1146 	}
1147 	if (sym->flags & SYMBOL_CHECKED)
1148 		return NULL;
1149 
1150 	if (sym_is_choice_value(sym)) {
1151 		struct dep_stack stack;
1152 
1153 		/* for choice groups start the check with main choice symbol */
1154 		dep_stack_insert(&stack, sym);
1155 		prop = sym_get_choice_prop(sym);
1156 		sym2 = sym_check_deps(prop_get_symbol(prop));
1157 		dep_stack_remove();
1158 	} else if (sym_is_choice(sym)) {
1159 		sym2 = sym_check_choice_deps(sym);
1160 	} else {
1161 		sym->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1162 		sym2 = sym_check_sym_deps(sym);
1163 		sym->flags &= ~SYMBOL_CHECK;
1164 	}
1165 
1166 	if (sym2 && sym2 == sym)
1167 		sym2 = NULL;
1168 
1169 	return sym2;
1170 }
1171 
1172 struct property *prop_alloc(enum prop_type type, struct symbol *sym)
1173 {
1174 	struct property *prop;
1175 	struct property **propp;
1176 
1177 	prop = malloc(sizeof(*prop));
1178 	memset(prop, 0, sizeof(*prop));
1179 	prop->type = type;
1180 	prop->sym = sym;
1181 	prop->file = current_file;
1182 	prop->lineno = zconf_lineno();
1183 
1184 	/* append property to the prop list of symbol */
1185 	if (sym) {
1186 		for (propp = &sym->prop; *propp; propp = &(*propp)->next)
1187 			;
1188 		*propp = prop;
1189 	}
1190 
1191 	return prop;
1192 }
1193 
1194 struct symbol *prop_get_symbol(struct property *prop)
1195 {
1196 	if (prop->expr && (prop->expr->type == E_SYMBOL ||
1197 			   prop->expr->type == E_LIST))
1198 		return prop->expr->left.sym;
1199 	return NULL;
1200 }
1201 
1202 const char *prop_get_type_name(enum prop_type type)
1203 {
1204 	switch (type) {
1205 	case P_PROMPT:
1206 		return "prompt";
1207 	case P_ENV:
1208 		return "env";
1209 	case P_COMMENT:
1210 		return "comment";
1211 	case P_MENU:
1212 		return "menu";
1213 	case P_DEFAULT:
1214 		return "default";
1215 	case P_CHOICE:
1216 		return "choice";
1217 	case P_SELECT:
1218 		return "select";
1219 	case P_RANGE:
1220 		return "range";
1221 	case P_SYMBOL:
1222 		return "symbol";
1223 	case P_UNKNOWN:
1224 		break;
1225 	}
1226 	return "unknown";
1227 }
1228 
1229 static void prop_add_env(const char *env)
1230 {
1231 	struct symbol *sym, *sym2;
1232 	struct property *prop;
1233 	char *p;
1234 
1235 	sym = current_entry->sym;
1236 	sym->flags |= SYMBOL_AUTO;
1237 	for_all_properties(sym, prop, P_ENV) {
1238 		sym2 = prop_get_symbol(prop);
1239 		if (strcmp(sym2->name, env))
1240 			menu_warn(current_entry, "redefining environment symbol from %s",
1241 				  sym2->name);
1242 		return;
1243 	}
1244 
1245 	prop = prop_alloc(P_ENV, sym);
1246 	prop->expr = expr_alloc_symbol(sym_lookup(env, SYMBOL_CONST));
1247 
1248 	sym_env_list = expr_alloc_one(E_LIST, sym_env_list);
1249 	sym_env_list->right.sym = sym;
1250 
1251 	p = getenv(env);
1252 	if (p)
1253 		sym_add_default(sym, p);
1254 	else
1255 		menu_warn(current_entry, "environment variable %s undefined", env);
1256 }
1257