xref: /linux/scripts/kconfig/symbol.c (revision f2ee442115c9b6219083c019939a9cc0c9abb2f8) 
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 #include "lkc.h"
13 
14 struct symbol symbol_yes = {
15 	.name = "y",
16 	.curr = { "y", yes },
17 	.flags = SYMBOL_CONST|SYMBOL_VALID,
18 }, symbol_mod = {
19 	.name = "m",
20 	.curr = { "m", mod },
21 	.flags = SYMBOL_CONST|SYMBOL_VALID,
22 }, symbol_no = {
23 	.name = "n",
24 	.curr = { "n", no },
25 	.flags = SYMBOL_CONST|SYMBOL_VALID,
26 }, symbol_empty = {
27 	.name = "",
28 	.curr = { "", no },
29 	.flags = SYMBOL_VALID,
30 };
31 
32 struct symbol *sym_defconfig_list;
33 struct symbol *modules_sym;
34 tristate modules_val;
35 
36 struct expr *sym_env_list;
37 
38 static void sym_add_default(struct symbol *sym, const char *def)
39 {
40 	struct property *prop = prop_alloc(P_DEFAULT, sym);
41 
42 	prop->expr = expr_alloc_symbol(sym_lookup(def, SYMBOL_CONST));
43 }
44 
45 void sym_init(void)
46 {
47 	struct symbol *sym;
48 	struct utsname uts;
49 	static bool inited = false;
50 
51 	if (inited)
52 		return;
53 	inited = true;
54 
55 	uname(&uts);
56 
57 	sym = sym_lookup("UNAME_RELEASE", 0);
58 	sym->type = S_STRING;
59 	sym->flags |= SYMBOL_AUTO;
60 	sym_add_default(sym, uts.release);
61 }
62 
63 enum symbol_type sym_get_type(struct symbol *sym)
64 {
65 	enum symbol_type type = sym->type;
66 
67 	if (type == S_TRISTATE) {
68 		if (sym_is_choice_value(sym) && sym->visible == yes)
69 			type = S_BOOLEAN;
70 		else if (modules_val == no)
71 			type = S_BOOLEAN;
72 	}
73 	return type;
74 }
75 
76 const char *sym_type_name(enum symbol_type type)
77 {
78 	switch (type) {
79 	case S_BOOLEAN:
80 		return "boolean";
81 	case S_TRISTATE:
82 		return "tristate";
83 	case S_INT:
84 		return "integer";
85 	case S_HEX:
86 		return "hex";
87 	case S_STRING:
88 		return "string";
89 	case S_UNKNOWN:
90 		return "unknown";
91 	case S_OTHER:
92 		break;
93 	}
94 	return "???";
95 }
96 
97 struct property *sym_get_choice_prop(struct symbol *sym)
98 {
99 	struct property *prop;
100 
101 	for_all_choices(sym, prop)
102 		return prop;
103 	return NULL;
104 }
105 
106 struct property *sym_get_env_prop(struct symbol *sym)
107 {
108 	struct property *prop;
109 
110 	for_all_properties(sym, prop, P_ENV)
111 		return prop;
112 	return NULL;
113 }
114 
115 struct property *sym_get_default_prop(struct symbol *sym)
116 {
117 	struct property *prop;
118 
119 	for_all_defaults(sym, prop) {
120 		prop->visible.tri = expr_calc_value(prop->visible.expr);
121 		if (prop->visible.tri != no)
122 			return prop;
123 	}
124 	return NULL;
125 }
126 
127 static struct property *sym_get_range_prop(struct symbol *sym)
128 {
129 	struct property *prop;
130 
131 	for_all_properties(sym, prop, P_RANGE) {
132 		prop->visible.tri = expr_calc_value(prop->visible.expr);
133 		if (prop->visible.tri != no)
134 			return prop;
135 	}
136 	return NULL;
137 }
138 
139 static int sym_get_range_val(struct symbol *sym, int base)
140 {
141 	sym_calc_value(sym);
142 	switch (sym->type) {
143 	case S_INT:
144 		base = 10;
145 		break;
146 	case S_HEX:
147 		base = 16;
148 		break;
149 	default:
150 		break;
151 	}
152 	return strtol(sym->curr.val, NULL, base);
153 }
154 
155 static void sym_validate_range(struct symbol *sym)
156 {
157 	struct property *prop;
158 	int base, val, val2;
159 	char str[64];
160 
161 	switch (sym->type) {
162 	case S_INT:
163 		base = 10;
164 		break;
165 	case S_HEX:
166 		base = 16;
167 		break;
168 	default:
169 		return;
170 	}
171 	prop = sym_get_range_prop(sym);
172 	if (!prop)
173 		return;
174 	val = strtol(sym->curr.val, NULL, base);
175 	val2 = sym_get_range_val(prop->expr->left.sym, base);
176 	if (val >= val2) {
177 		val2 = sym_get_range_val(prop->expr->right.sym, base);
178 		if (val <= val2)
179 			return;
180 	}
181 	if (sym->type == S_INT)
182 		sprintf(str, "%d", val2);
183 	else
184 		sprintf(str, "0x%x", val2);
185 	sym->curr.val = strdup(str);
186 }
187 
188 static void sym_calc_visibility(struct symbol *sym)
189 {
190 	struct property *prop;
191 	tristate tri;
192 
193 	/* any prompt visible? */
194 	tri = no;
195 	for_all_prompts(sym, prop) {
196 		prop->visible.tri = expr_calc_value(prop->visible.expr);
197 		tri = EXPR_OR(tri, prop->visible.tri);
198 	}
199 	if (tri == mod && (sym->type != S_TRISTATE || modules_val == no))
200 		tri = yes;
201 	if (sym->visible != tri) {
202 		sym->visible = tri;
203 		sym_set_changed(sym);
204 	}
205 	if (sym_is_choice_value(sym))
206 		return;
207 	/* defaulting to "yes" if no explicit "depends on" are given */
208 	tri = yes;
209 	if (sym->dir_dep.expr)
210 		tri = expr_calc_value(sym->dir_dep.expr);
211 	if (tri == mod)
212 		tri = yes;
213 	if (sym->dir_dep.tri != tri) {
214 		sym->dir_dep.tri = tri;
215 		sym_set_changed(sym);
216 	}
217 	tri = no;
218 	if (sym->rev_dep.expr)
219 		tri = expr_calc_value(sym->rev_dep.expr);
220 	if (tri == mod && sym_get_type(sym) == S_BOOLEAN)
221 		tri = yes;
222 	if (sym->rev_dep.tri != tri) {
223 		sym->rev_dep.tri = tri;
224 		sym_set_changed(sym);
225 	}
226 }
227 
228 /*
229  * Find the default symbol for a choice.
230  * First try the default values for the choice symbol
231  * Next locate the first visible choice value
232  * Return NULL if none was found
233  */
234 struct symbol *sym_choice_default(struct symbol *sym)
235 {
236 	struct symbol *def_sym;
237 	struct property *prop;
238 	struct expr *e;
239 
240 	/* any of the defaults visible? */
241 	for_all_defaults(sym, prop) {
242 		prop->visible.tri = expr_calc_value(prop->visible.expr);
243 		if (prop->visible.tri == no)
244 			continue;
245 		def_sym = prop_get_symbol(prop);
246 		if (def_sym->visible != no)
247 			return def_sym;
248 	}
249 
250 	/* just get the first visible value */
251 	prop = sym_get_choice_prop(sym);
252 	expr_list_for_each_sym(prop->expr, e, def_sym)
253 		if (def_sym->visible != no)
254 			return def_sym;
255 
256 	/* failed to locate any defaults */
257 	return NULL;
258 }
259 
260 static struct symbol *sym_calc_choice(struct symbol *sym)
261 {
262 	struct symbol *def_sym;
263 	struct property *prop;
264 	struct expr *e;
265 
266 	/* first calculate all choice values' visibilities */
267 	prop = sym_get_choice_prop(sym);
268 	expr_list_for_each_sym(prop->expr, e, def_sym)
269 		sym_calc_visibility(def_sym);
270 
271 	/* is the user choice visible? */
272 	def_sym = sym->def[S_DEF_USER].val;
273 	if (def_sym && def_sym->visible != no)
274 		return def_sym;
275 
276 	def_sym = sym_choice_default(sym);
277 
278 	if (def_sym == NULL)
279 		/* no choice? reset tristate value */
280 		sym->curr.tri = no;
281 
282 	return def_sym;
283 }
284 
285 void sym_calc_value(struct symbol *sym)
286 {
287 	struct symbol_value newval, oldval;
288 	struct property *prop;
289 	struct expr *e;
290 
291 	if (!sym)
292 		return;
293 
294 	if (sym->flags & SYMBOL_VALID)
295 		return;
296 	sym->flags |= SYMBOL_VALID;
297 
298 	oldval = sym->curr;
299 
300 	switch (sym->type) {
301 	case S_INT:
302 	case S_HEX:
303 	case S_STRING:
304 		newval = symbol_empty.curr;
305 		break;
306 	case S_BOOLEAN:
307 	case S_TRISTATE:
308 		newval = symbol_no.curr;
309 		break;
310 	default:
311 		sym->curr.val = sym->name;
312 		sym->curr.tri = no;
313 		return;
314 	}
315 	if (!sym_is_choice_value(sym))
316 		sym->flags &= ~SYMBOL_WRITE;
317 
318 	sym_calc_visibility(sym);
319 
320 	/* set default if recursively called */
321 	sym->curr = newval;
322 
323 	switch (sym_get_type(sym)) {
324 	case S_BOOLEAN:
325 	case S_TRISTATE:
326 		if (sym_is_choice_value(sym) && sym->visible == yes) {
327 			prop = sym_get_choice_prop(sym);
328 			newval.tri = (prop_get_symbol(prop)->curr.val == sym) ? yes : no;
329 		} else {
330 			if (sym->visible != no) {
331 				/* if the symbol is visible use the user value
332 				 * if available, otherwise try the default value
333 				 */
334 				sym->flags |= SYMBOL_WRITE;
335 				if (sym_has_value(sym)) {
336 					newval.tri = EXPR_AND(sym->def[S_DEF_USER].tri,
337 							      sym->visible);
338 					goto calc_newval;
339 				}
340 			}
341 			if (sym->rev_dep.tri != no)
342 				sym->flags |= SYMBOL_WRITE;
343 			if (!sym_is_choice(sym)) {
344 				prop = sym_get_default_prop(sym);
345 				if (prop) {
346 					sym->flags |= SYMBOL_WRITE;
347 					newval.tri = EXPR_AND(expr_calc_value(prop->expr),
348 							      prop->visible.tri);
349 				}
350 			}
351 		calc_newval:
352 			if (sym->dir_dep.tri == no && sym->rev_dep.tri != no) {
353 				struct expr *e;
354 				e = expr_simplify_unmet_dep(sym->rev_dep.expr,
355 				    sym->dir_dep.expr);
356 				fprintf(stderr, "warning: (");
357 				expr_fprint(e, stderr);
358 				fprintf(stderr, ") selects %s which has unmet direct dependencies (",
359 					sym->name);
360 				expr_fprint(sym->dir_dep.expr, stderr);
361 				fprintf(stderr, ")\n");
362 				expr_free(e);
363 			}
364 			newval.tri = EXPR_OR(newval.tri, sym->rev_dep.tri);
365 		}
366 		if (newval.tri == mod && sym_get_type(sym) == S_BOOLEAN)
367 			newval.tri = yes;
368 		break;
369 	case S_STRING:
370 	case S_HEX:
371 	case S_INT:
372 		if (sym->visible != no) {
373 			sym->flags |= SYMBOL_WRITE;
374 			if (sym_has_value(sym)) {
375 				newval.val = sym->def[S_DEF_USER].val;
376 				break;
377 			}
378 		}
379 		prop = sym_get_default_prop(sym);
380 		if (prop) {
381 			struct symbol *ds = prop_get_symbol(prop);
382 			if (ds) {
383 				sym->flags |= SYMBOL_WRITE;
384 				sym_calc_value(ds);
385 				newval.val = ds->curr.val;
386 			}
387 		}
388 		break;
389 	default:
390 		;
391 	}
392 
393 	sym->curr = newval;
394 	if (sym_is_choice(sym) && newval.tri == yes)
395 		sym->curr.val = sym_calc_choice(sym);
396 	sym_validate_range(sym);
397 
398 	if (memcmp(&oldval, &sym->curr, sizeof(oldval))) {
399 		sym_set_changed(sym);
400 		if (modules_sym == sym) {
401 			sym_set_all_changed();
402 			modules_val = modules_sym->curr.tri;
403 		}
404 	}
405 
406 	if (sym_is_choice(sym)) {
407 		struct symbol *choice_sym;
408 
409 		prop = sym_get_choice_prop(sym);
410 		expr_list_for_each_sym(prop->expr, e, choice_sym) {
411 			if ((sym->flags & SYMBOL_WRITE) &&
412 			    choice_sym->visible != no)
413 				choice_sym->flags |= SYMBOL_WRITE;
414 			if (sym->flags & SYMBOL_CHANGED)
415 				sym_set_changed(choice_sym);
416 		}
417 	}
418 
419 	if (sym->flags & SYMBOL_AUTO)
420 		sym->flags &= ~SYMBOL_WRITE;
421 }
422 
423 void sym_clear_all_valid(void)
424 {
425 	struct symbol *sym;
426 	int i;
427 
428 	for_all_symbols(i, sym)
429 		sym->flags &= ~SYMBOL_VALID;
430 	sym_add_change_count(1);
431 	if (modules_sym)
432 		sym_calc_value(modules_sym);
433 }
434 
435 void sym_set_changed(struct symbol *sym)
436 {
437 	struct property *prop;
438 
439 	sym->flags |= SYMBOL_CHANGED;
440 	for (prop = sym->prop; prop; prop = prop->next) {
441 		if (prop->menu)
442 			prop->menu->flags |= MENU_CHANGED;
443 	}
444 }
445 
446 void sym_set_all_changed(void)
447 {
448 	struct symbol *sym;
449 	int i;
450 
451 	for_all_symbols(i, sym)
452 		sym_set_changed(sym);
453 }
454 
455 bool sym_tristate_within_range(struct symbol *sym, tristate val)
456 {
457 	int type = sym_get_type(sym);
458 
459 	if (sym->visible == no)
460 		return false;
461 
462 	if (type != S_BOOLEAN && type != S_TRISTATE)
463 		return false;
464 
465 	if (type == S_BOOLEAN && val == mod)
466 		return false;
467 	if (sym->visible <= sym->rev_dep.tri)
468 		return false;
469 	if (sym_is_choice_value(sym) && sym->visible == yes)
470 		return val == yes;
471 	return val >= sym->rev_dep.tri && val <= sym->visible;
472 }
473 
474 bool sym_set_tristate_value(struct symbol *sym, tristate val)
475 {
476 	tristate oldval = sym_get_tristate_value(sym);
477 
478 	if (oldval != val && !sym_tristate_within_range(sym, val))
479 		return false;
480 
481 	if (!(sym->flags & SYMBOL_DEF_USER)) {
482 		sym->flags |= SYMBOL_DEF_USER;
483 		sym_set_changed(sym);
484 	}
485 	/*
486 	 * setting a choice value also resets the new flag of the choice
487 	 * symbol and all other choice values.
488 	 */
489 	if (sym_is_choice_value(sym) && val == yes) {
490 		struct symbol *cs = prop_get_symbol(sym_get_choice_prop(sym));
491 		struct property *prop;
492 		struct expr *e;
493 
494 		cs->def[S_DEF_USER].val = sym;
495 		cs->flags |= SYMBOL_DEF_USER;
496 		prop = sym_get_choice_prop(cs);
497 		for (e = prop->expr; e; e = e->left.expr) {
498 			if (e->right.sym->visible != no)
499 				e->right.sym->flags |= SYMBOL_DEF_USER;
500 		}
501 	}
502 
503 	sym->def[S_DEF_USER].tri = val;
504 	if (oldval != val)
505 		sym_clear_all_valid();
506 
507 	return true;
508 }
509 
510 tristate sym_toggle_tristate_value(struct symbol *sym)
511 {
512 	tristate oldval, newval;
513 
514 	oldval = newval = sym_get_tristate_value(sym);
515 	do {
516 		switch (newval) {
517 		case no:
518 			newval = mod;
519 			break;
520 		case mod:
521 			newval = yes;
522 			break;
523 		case yes:
524 			newval = no;
525 			break;
526 		}
527 		if (sym_set_tristate_value(sym, newval))
528 			break;
529 	} while (oldval != newval);
530 	return newval;
531 }
532 
533 bool sym_string_valid(struct symbol *sym, const char *str)
534 {
535 	signed char ch;
536 
537 	switch (sym->type) {
538 	case S_STRING:
539 		return true;
540 	case S_INT:
541 		ch = *str++;
542 		if (ch == '-')
543 			ch = *str++;
544 		if (!isdigit(ch))
545 			return false;
546 		if (ch == '0' && *str != 0)
547 			return false;
548 		while ((ch = *str++)) {
549 			if (!isdigit(ch))
550 				return false;
551 		}
552 		return true;
553 	case S_HEX:
554 		if (str[0] == '0' && (str[1] == 'x' || str[1] == 'X'))
555 			str += 2;
556 		ch = *str++;
557 		do {
558 			if (!isxdigit(ch))
559 				return false;
560 		} while ((ch = *str++));
561 		return true;
562 	case S_BOOLEAN:
563 	case S_TRISTATE:
564 		switch (str[0]) {
565 		case 'y': case 'Y':
566 		case 'm': case 'M':
567 		case 'n': case 'N':
568 			return true;
569 		}
570 		return false;
571 	default:
572 		return false;
573 	}
574 }
575 
576 bool sym_string_within_range(struct symbol *sym, const char *str)
577 {
578 	struct property *prop;
579 	int val;
580 
581 	switch (sym->type) {
582 	case S_STRING:
583 		return sym_string_valid(sym, str);
584 	case S_INT:
585 		if (!sym_string_valid(sym, str))
586 			return false;
587 		prop = sym_get_range_prop(sym);
588 		if (!prop)
589 			return true;
590 		val = strtol(str, NULL, 10);
591 		return val >= sym_get_range_val(prop->expr->left.sym, 10) &&
592 		       val <= sym_get_range_val(prop->expr->right.sym, 10);
593 	case S_HEX:
594 		if (!sym_string_valid(sym, str))
595 			return false;
596 		prop = sym_get_range_prop(sym);
597 		if (!prop)
598 			return true;
599 		val = strtol(str, NULL, 16);
600 		return val >= sym_get_range_val(prop->expr->left.sym, 16) &&
601 		       val <= sym_get_range_val(prop->expr->right.sym, 16);
602 	case S_BOOLEAN:
603 	case S_TRISTATE:
604 		switch (str[0]) {
605 		case 'y': case 'Y':
606 			return sym_tristate_within_range(sym, yes);
607 		case 'm': case 'M':
608 			return sym_tristate_within_range(sym, mod);
609 		case 'n': case 'N':
610 			return sym_tristate_within_range(sym, no);
611 		}
612 		return false;
613 	default:
614 		return false;
615 	}
616 }
617 
618 bool sym_set_string_value(struct symbol *sym, const char *newval)
619 {
620 	const char *oldval;
621 	char *val;
622 	int size;
623 
624 	switch (sym->type) {
625 	case S_BOOLEAN:
626 	case S_TRISTATE:
627 		switch (newval[0]) {
628 		case 'y': case 'Y':
629 			return sym_set_tristate_value(sym, yes);
630 		case 'm': case 'M':
631 			return sym_set_tristate_value(sym, mod);
632 		case 'n': case 'N':
633 			return sym_set_tristate_value(sym, no);
634 		}
635 		return false;
636 	default:
637 		;
638 	}
639 
640 	if (!sym_string_within_range(sym, newval))
641 		return false;
642 
643 	if (!(sym->flags & SYMBOL_DEF_USER)) {
644 		sym->flags |= SYMBOL_DEF_USER;
645 		sym_set_changed(sym);
646 	}
647 
648 	oldval = sym->def[S_DEF_USER].val;
649 	size = strlen(newval) + 1;
650 	if (sym->type == S_HEX && (newval[0] != '0' || (newval[1] != 'x' && newval[1] != 'X'))) {
651 		size += 2;
652 		sym->def[S_DEF_USER].val = val = malloc(size);
653 		*val++ = '0';
654 		*val++ = 'x';
655 	} else if (!oldval || strcmp(oldval, newval))
656 		sym->def[S_DEF_USER].val = val = malloc(size);
657 	else
658 		return true;
659 
660 	strcpy(val, newval);
661 	free((void *)oldval);
662 	sym_clear_all_valid();
663 
664 	return true;
665 }
666 
667 /*
668  * Find the default value associated to a symbol.
669  * For tristate symbol handle the modules=n case
670  * in which case "m" becomes "y".
671  * If the symbol does not have any default then fallback
672  * to the fixed default values.
673  */
674 const char *sym_get_string_default(struct symbol *sym)
675 {
676 	struct property *prop;
677 	struct symbol *ds;
678 	const char *str;
679 	tristate val;
680 
681 	sym_calc_visibility(sym);
682 	sym_calc_value(modules_sym);
683 	val = symbol_no.curr.tri;
684 	str = symbol_empty.curr.val;
685 
686 	/* If symbol has a default value look it up */
687 	prop = sym_get_default_prop(sym);
688 	if (prop != NULL) {
689 		switch (sym->type) {
690 		case S_BOOLEAN:
691 		case S_TRISTATE:
692 			/* The visibility may limit the value from yes => mod */
693 			val = EXPR_AND(expr_calc_value(prop->expr), prop->visible.tri);
694 			break;
695 		default:
696 			/*
697 			 * The following fails to handle the situation
698 			 * where a default value is further limited by
699 			 * the valid range.
700 			 */
701 			ds = prop_get_symbol(prop);
702 			if (ds != NULL) {
703 				sym_calc_value(ds);
704 				str = (const char *)ds->curr.val;
705 			}
706 		}
707 	}
708 
709 	/* Handle select statements */
710 	val = EXPR_OR(val, sym->rev_dep.tri);
711 
712 	/* transpose mod to yes if modules are not enabled */
713 	if (val == mod)
714 		if (!sym_is_choice_value(sym) && modules_sym->curr.tri == no)
715 			val = yes;
716 
717 	/* transpose mod to yes if type is bool */
718 	if (sym->type == S_BOOLEAN && val == mod)
719 		val = yes;
720 
721 	switch (sym->type) {
722 	case S_BOOLEAN:
723 	case S_TRISTATE:
724 		switch (val) {
725 		case no: return "n";
726 		case mod: return "m";
727 		case yes: return "y";
728 		}
729 	case S_INT:
730 	case S_HEX:
731 		return str;
732 	case S_STRING:
733 		return str;
734 	case S_OTHER:
735 	case S_UNKNOWN:
736 		break;
737 	}
738 	return "";
739 }
740 
741 const char *sym_get_string_value(struct symbol *sym)
742 {
743 	tristate val;
744 
745 	switch (sym->type) {
746 	case S_BOOLEAN:
747 	case S_TRISTATE:
748 		val = sym_get_tristate_value(sym);
749 		switch (val) {
750 		case no:
751 			return "n";
752 		case mod:
753 			sym_calc_value(modules_sym);
754 			return (modules_sym->curr.tri == no) ? "n" : "m";
755 		case yes:
756 			return "y";
757 		}
758 		break;
759 	default:
760 		;
761 	}
762 	return (const char *)sym->curr.val;
763 }
764 
765 bool sym_is_changable(struct symbol *sym)
766 {
767 	return sym->visible > sym->rev_dep.tri;
768 }
769 
770 static unsigned strhash(const char *s)
771 {
772 	/* fnv32 hash */
773 	unsigned hash = 2166136261U;
774 	for (; *s; s++)
775 		hash = (hash ^ *s) * 0x01000193;
776 	return hash;
777 }
778 
779 struct symbol *sym_lookup(const char *name, int flags)
780 {
781 	struct symbol *symbol;
782 	char *new_name;
783 	int hash;
784 
785 	if (name) {
786 		if (name[0] && !name[1]) {
787 			switch (name[0]) {
788 			case 'y': return &symbol_yes;
789 			case 'm': return &symbol_mod;
790 			case 'n': return &symbol_no;
791 			}
792 		}
793 		hash = strhash(name) % SYMBOL_HASHSIZE;
794 
795 		for (symbol = symbol_hash[hash]; symbol; symbol = symbol->next) {
796 			if (symbol->name &&
797 			    !strcmp(symbol->name, name) &&
798 			    (flags ? symbol->flags & flags
799 				   : !(symbol->flags & (SYMBOL_CONST|SYMBOL_CHOICE))))
800 				return symbol;
801 		}
802 		new_name = strdup(name);
803 	} else {
804 		new_name = NULL;
805 		hash = 0;
806 	}
807 
808 	symbol = malloc(sizeof(*symbol));
809 	memset(symbol, 0, sizeof(*symbol));
810 	symbol->name = new_name;
811 	symbol->type = S_UNKNOWN;
812 	symbol->flags |= flags;
813 
814 	symbol->next = symbol_hash[hash];
815 	symbol_hash[hash] = symbol;
816 
817 	return symbol;
818 }
819 
820 struct symbol *sym_find(const char *name)
821 {
822 	struct symbol *symbol = NULL;
823 	int hash = 0;
824 
825 	if (!name)
826 		return NULL;
827 
828 	if (name[0] && !name[1]) {
829 		switch (name[0]) {
830 		case 'y': return &symbol_yes;
831 		case 'm': return &symbol_mod;
832 		case 'n': return &symbol_no;
833 		}
834 	}
835 	hash = strhash(name) % SYMBOL_HASHSIZE;
836 
837 	for (symbol = symbol_hash[hash]; symbol; symbol = symbol->next) {
838 		if (symbol->name &&
839 		    !strcmp(symbol->name, name) &&
840 		    !(symbol->flags & SYMBOL_CONST))
841 				break;
842 	}
843 
844 	return symbol;
845 }
846 
847 /*
848  * Expand symbol's names embedded in the string given in argument. Symbols'
849  * name to be expanded shall be prefixed by a '$'. Unknown symbol expands to
850  * the empty string.
851  */
852 const char *sym_expand_string_value(const char *in)
853 {
854 	const char *src;
855 	char *res;
856 	size_t reslen;
857 
858 	reslen = strlen(in) + 1;
859 	res = malloc(reslen);
860 	res[0] = '\0';
861 
862 	while ((src = strchr(in, '$'))) {
863 		char *p, name[SYMBOL_MAXLENGTH];
864 		const char *symval = "";
865 		struct symbol *sym;
866 		size_t newlen;
867 
868 		strncat(res, in, src - in);
869 		src++;
870 
871 		p = name;
872 		while (isalnum(*src) || *src == '_')
873 			*p++ = *src++;
874 		*p = '\0';
875 
876 		sym = sym_find(name);
877 		if (sym != NULL) {
878 			sym_calc_value(sym);
879 			symval = sym_get_string_value(sym);
880 		}
881 
882 		newlen = strlen(res) + strlen(symval) + strlen(src) + 1;
883 		if (newlen > reslen) {
884 			reslen = newlen;
885 			res = realloc(res, reslen);
886 		}
887 
888 		strcat(res, symval);
889 		in = src;
890 	}
891 	strcat(res, in);
892 
893 	return res;
894 }
895 
896 const char *sym_escape_string_value(const char *in)
897 {
898 	const char *p;
899 	size_t reslen;
900 	char *res;
901 	size_t l;
902 
903 	reslen = strlen(in) + strlen("\"\"") + 1;
904 
905 	p = in;
906 	for (;;) {
907 		l = strcspn(p, "\"\\");
908 		p += l;
909 
910 		if (p[0] == '\0')
911 			break;
912 
913 		reslen++;
914 		p++;
915 	}
916 
917 	res = malloc(reslen);
918 	res[0] = '\0';
919 
920 	strcat(res, "\"");
921 
922 	p = in;
923 	for (;;) {
924 		l = strcspn(p, "\"\\");
925 		strncat(res, p, l);
926 		p += l;
927 
928 		if (p[0] == '\0')
929 			break;
930 
931 		strcat(res, "\\");
932 		strncat(res, p++, 1);
933 	}
934 
935 	strcat(res, "\"");
936 	return res;
937 }
938 
939 struct symbol **sym_re_search(const char *pattern)
940 {
941 	struct symbol *sym, **sym_arr = NULL;
942 	int i, cnt, size;
943 	regex_t re;
944 
945 	cnt = size = 0;
946 	/* Skip if empty */
947 	if (strlen(pattern) == 0)
948 		return NULL;
949 	if (regcomp(&re, pattern, REG_EXTENDED|REG_NOSUB|REG_ICASE))
950 		return NULL;
951 
952 	for_all_symbols(i, sym) {
953 		if (sym->flags & SYMBOL_CONST || !sym->name)
954 			continue;
955 		if (regexec(&re, sym->name, 0, NULL, 0))
956 			continue;
957 		if (cnt + 1 >= size) {
958 			void *tmp = sym_arr;
959 			size += 16;
960 			sym_arr = realloc(sym_arr, size * sizeof(struct symbol *));
961 			if (!sym_arr) {
962 				free(tmp);
963 				return NULL;
964 			}
965 		}
966 		sym_calc_value(sym);
967 		sym_arr[cnt++] = sym;
968 	}
969 	if (sym_arr)
970 		sym_arr[cnt] = NULL;
971 	regfree(&re);
972 
973 	return sym_arr;
974 }
975 
976 /*
977  * When we check for recursive dependencies we use a stack to save
978  * current state so we can print out relevant info to user.
979  * The entries are located on the call stack so no need to free memory.
980  * Note inser() remove() must always match to properly clear the stack.
981  */
982 static struct dep_stack {
983 	struct dep_stack *prev, *next;
984 	struct symbol *sym;
985 	struct property *prop;
986 	struct expr *expr;
987 } *check_top;
988 
989 static void dep_stack_insert(struct dep_stack *stack, struct symbol *sym)
990 {
991 	memset(stack, 0, sizeof(*stack));
992 	if (check_top)
993 		check_top->next = stack;
994 	stack->prev = check_top;
995 	stack->sym = sym;
996 	check_top = stack;
997 }
998 
999 static void dep_stack_remove(void)
1000 {
1001 	check_top = check_top->prev;
1002 	if (check_top)
1003 		check_top->next = NULL;
1004 }
1005 
1006 /*
1007  * Called when we have detected a recursive dependency.
1008  * check_top point to the top of the stact so we use
1009  * the ->prev pointer to locate the bottom of the stack.
1010  */
1011 static void sym_check_print_recursive(struct symbol *last_sym)
1012 {
1013 	struct dep_stack *stack;
1014 	struct symbol *sym, *next_sym;
1015 	struct menu *menu = NULL;
1016 	struct property *prop;
1017 	struct dep_stack cv_stack;
1018 
1019 	if (sym_is_choice_value(last_sym)) {
1020 		dep_stack_insert(&cv_stack, last_sym);
1021 		last_sym = prop_get_symbol(sym_get_choice_prop(last_sym));
1022 	}
1023 
1024 	for (stack = check_top; stack != NULL; stack = stack->prev)
1025 		if (stack->sym == last_sym)
1026 			break;
1027 	if (!stack) {
1028 		fprintf(stderr, "unexpected recursive dependency error\n");
1029 		return;
1030 	}
1031 
1032 	for (; stack; stack = stack->next) {
1033 		sym = stack->sym;
1034 		next_sym = stack->next ? stack->next->sym : last_sym;
1035 		prop = stack->prop;
1036 		if (prop == NULL)
1037 			prop = stack->sym->prop;
1038 
1039 		/* for choice values find the menu entry (used below) */
1040 		if (sym_is_choice(sym) || sym_is_choice_value(sym)) {
1041 			for (prop = sym->prop; prop; prop = prop->next) {
1042 				menu = prop->menu;
1043 				if (prop->menu)
1044 					break;
1045 			}
1046 		}
1047 		if (stack->sym == last_sym)
1048 			fprintf(stderr, "%s:%d:error: recursive dependency detected!\n",
1049 				prop->file->name, prop->lineno);
1050 		if (stack->expr) {
1051 			fprintf(stderr, "%s:%d:\tsymbol %s %s value contains %s\n",
1052 				prop->file->name, prop->lineno,
1053 				sym->name ? sym->name : "<choice>",
1054 				prop_get_type_name(prop->type),
1055 				next_sym->name ? next_sym->name : "<choice>");
1056 		} else if (stack->prop) {
1057 			fprintf(stderr, "%s:%d:\tsymbol %s depends on %s\n",
1058 				prop->file->name, prop->lineno,
1059 				sym->name ? sym->name : "<choice>",
1060 				next_sym->name ? next_sym->name : "<choice>");
1061 		} else if (sym_is_choice(sym)) {
1062 			fprintf(stderr, "%s:%d:\tchoice %s contains symbol %s\n",
1063 				menu->file->name, menu->lineno,
1064 				sym->name ? sym->name : "<choice>",
1065 				next_sym->name ? next_sym->name : "<choice>");
1066 		} else if (sym_is_choice_value(sym)) {
1067 			fprintf(stderr, "%s:%d:\tsymbol %s is part of choice %s\n",
1068 				menu->file->name, menu->lineno,
1069 				sym->name ? sym->name : "<choice>",
1070 				next_sym->name ? next_sym->name : "<choice>");
1071 		} else {
1072 			fprintf(stderr, "%s:%d:\tsymbol %s is selected by %s\n",
1073 				prop->file->name, prop->lineno,
1074 				sym->name ? sym->name : "<choice>",
1075 				next_sym->name ? next_sym->name : "<choice>");
1076 		}
1077 	}
1078 
1079 	if (check_top == &cv_stack)
1080 		dep_stack_remove();
1081 }
1082 
1083 static struct symbol *sym_check_expr_deps(struct expr *e)
1084 {
1085 	struct symbol *sym;
1086 
1087 	if (!e)
1088 		return NULL;
1089 	switch (e->type) {
1090 	case E_OR:
1091 	case E_AND:
1092 		sym = sym_check_expr_deps(e->left.expr);
1093 		if (sym)
1094 			return sym;
1095 		return sym_check_expr_deps(e->right.expr);
1096 	case E_NOT:
1097 		return sym_check_expr_deps(e->left.expr);
1098 	case E_EQUAL:
1099 	case E_UNEQUAL:
1100 		sym = sym_check_deps(e->left.sym);
1101 		if (sym)
1102 			return sym;
1103 		return sym_check_deps(e->right.sym);
1104 	case E_SYMBOL:
1105 		return sym_check_deps(e->left.sym);
1106 	default:
1107 		break;
1108 	}
1109 	printf("Oops! How to check %d?\n", e->type);
1110 	return NULL;
1111 }
1112 
1113 /* return NULL when dependencies are OK */
1114 static struct symbol *sym_check_sym_deps(struct symbol *sym)
1115 {
1116 	struct symbol *sym2;
1117 	struct property *prop;
1118 	struct dep_stack stack;
1119 
1120 	dep_stack_insert(&stack, sym);
1121 
1122 	sym2 = sym_check_expr_deps(sym->rev_dep.expr);
1123 	if (sym2)
1124 		goto out;
1125 
1126 	for (prop = sym->prop; prop; prop = prop->next) {
1127 		if (prop->type == P_CHOICE || prop->type == P_SELECT)
1128 			continue;
1129 		stack.prop = prop;
1130 		sym2 = sym_check_expr_deps(prop->visible.expr);
1131 		if (sym2)
1132 			break;
1133 		if (prop->type != P_DEFAULT || sym_is_choice(sym))
1134 			continue;
1135 		stack.expr = prop->expr;
1136 		sym2 = sym_check_expr_deps(prop->expr);
1137 		if (sym2)
1138 			break;
1139 		stack.expr = NULL;
1140 	}
1141 
1142 out:
1143 	dep_stack_remove();
1144 
1145 	return sym2;
1146 }
1147 
1148 static struct symbol *sym_check_choice_deps(struct symbol *choice)
1149 {
1150 	struct symbol *sym, *sym2;
1151 	struct property *prop;
1152 	struct expr *e;
1153 	struct dep_stack stack;
1154 
1155 	dep_stack_insert(&stack, choice);
1156 
1157 	prop = sym_get_choice_prop(choice);
1158 	expr_list_for_each_sym(prop->expr, e, sym)
1159 		sym->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1160 
1161 	choice->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1162 	sym2 = sym_check_sym_deps(choice);
1163 	choice->flags &= ~SYMBOL_CHECK;
1164 	if (sym2)
1165 		goto out;
1166 
1167 	expr_list_for_each_sym(prop->expr, e, sym) {
1168 		sym2 = sym_check_sym_deps(sym);
1169 		if (sym2)
1170 			break;
1171 	}
1172 out:
1173 	expr_list_for_each_sym(prop->expr, e, sym)
1174 		sym->flags &= ~SYMBOL_CHECK;
1175 
1176 	if (sym2 && sym_is_choice_value(sym2) &&
1177 	    prop_get_symbol(sym_get_choice_prop(sym2)) == choice)
1178 		sym2 = choice;
1179 
1180 	dep_stack_remove();
1181 
1182 	return sym2;
1183 }
1184 
1185 struct symbol *sym_check_deps(struct symbol *sym)
1186 {
1187 	struct symbol *sym2;
1188 	struct property *prop;
1189 
1190 	if (sym->flags & SYMBOL_CHECK) {
1191 		sym_check_print_recursive(sym);
1192 		return sym;
1193 	}
1194 	if (sym->flags & SYMBOL_CHECKED)
1195 		return NULL;
1196 
1197 	if (sym_is_choice_value(sym)) {
1198 		struct dep_stack stack;
1199 
1200 		/* for choice groups start the check with main choice symbol */
1201 		dep_stack_insert(&stack, sym);
1202 		prop = sym_get_choice_prop(sym);
1203 		sym2 = sym_check_deps(prop_get_symbol(prop));
1204 		dep_stack_remove();
1205 	} else if (sym_is_choice(sym)) {
1206 		sym2 = sym_check_choice_deps(sym);
1207 	} else {
1208 		sym->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1209 		sym2 = sym_check_sym_deps(sym);
1210 		sym->flags &= ~SYMBOL_CHECK;
1211 	}
1212 
1213 	if (sym2 && sym2 == sym)
1214 		sym2 = NULL;
1215 
1216 	return sym2;
1217 }
1218 
1219 struct property *prop_alloc(enum prop_type type, struct symbol *sym)
1220 {
1221 	struct property *prop;
1222 	struct property **propp;
1223 
1224 	prop = malloc(sizeof(*prop));
1225 	memset(prop, 0, sizeof(*prop));
1226 	prop->type = type;
1227 	prop->sym = sym;
1228 	prop->file = current_file;
1229 	prop->lineno = zconf_lineno();
1230 
1231 	/* append property to the prop list of symbol */
1232 	if (sym) {
1233 		for (propp = &sym->prop; *propp; propp = &(*propp)->next)
1234 			;
1235 		*propp = prop;
1236 	}
1237 
1238 	return prop;
1239 }
1240 
1241 struct symbol *prop_get_symbol(struct property *prop)
1242 {
1243 	if (prop->expr && (prop->expr->type == E_SYMBOL ||
1244 			   prop->expr->type == E_LIST))
1245 		return prop->expr->left.sym;
1246 	return NULL;
1247 }
1248 
1249 const char *prop_get_type_name(enum prop_type type)
1250 {
1251 	switch (type) {
1252 	case P_PROMPT:
1253 		return "prompt";
1254 	case P_ENV:
1255 		return "env";
1256 	case P_COMMENT:
1257 		return "comment";
1258 	case P_MENU:
1259 		return "menu";
1260 	case P_DEFAULT:
1261 		return "default";
1262 	case P_CHOICE:
1263 		return "choice";
1264 	case P_SELECT:
1265 		return "select";
1266 	case P_RANGE:
1267 		return "range";
1268 	case P_SYMBOL:
1269 		return "symbol";
1270 	case P_UNKNOWN:
1271 		break;
1272 	}
1273 	return "unknown";
1274 }
1275 
1276 static void prop_add_env(const char *env)
1277 {
1278 	struct symbol *sym, *sym2;
1279 	struct property *prop;
1280 	char *p;
1281 
1282 	sym = current_entry->sym;
1283 	sym->flags |= SYMBOL_AUTO;
1284 	for_all_properties(sym, prop, P_ENV) {
1285 		sym2 = prop_get_symbol(prop);
1286 		if (strcmp(sym2->name, env))
1287 			menu_warn(current_entry, "redefining environment symbol from %s",
1288 				  sym2->name);
1289 		return;
1290 	}
1291 
1292 	prop = prop_alloc(P_ENV, sym);
1293 	prop->expr = expr_alloc_symbol(sym_lookup(env, SYMBOL_CONST));
1294 
1295 	sym_env_list = expr_alloc_one(E_LIST, sym_env_list);
1296 	sym_env_list->right.sym = sym;
1297 
1298 	p = getenv(env);
1299 	if (p)
1300 		sym_add_default(sym, p);
1301 	else
1302 		menu_warn(current_entry, "environment variable %s undefined", env);
1303 }
1304