xref: /openbmc/linux/scripts/kconfig/symbol.c (revision df2634f43f5106947f3735a0b61a6527a4b278cd) 
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 				struct expr *e;
355 				e = expr_simplify_unmet_dep(sym->rev_dep.expr,
356 				    sym->dir_dep.expr);
357 				fprintf(stderr, "warning: (");
358 				expr_fprint(e, stderr);
359 				fprintf(stderr, ") selects %s which has unmet direct dependencies (",
360 					sym->name);
361 				expr_fprint(sym->dir_dep.expr, stderr);
362 				fprintf(stderr, ")\n");
363 				expr_free(e);
364 			}
365 			newval.tri = EXPR_OR(newval.tri, sym->rev_dep.tri);
366 		}
367 		if (newval.tri == mod && sym_get_type(sym) == S_BOOLEAN)
368 			newval.tri = yes;
369 		break;
370 	case S_STRING:
371 	case S_HEX:
372 	case S_INT:
373 		if (sym->visible != no) {
374 			sym->flags |= SYMBOL_WRITE;
375 			if (sym_has_value(sym)) {
376 				newval.val = sym->def[S_DEF_USER].val;
377 				break;
378 			}
379 		}
380 		prop = sym_get_default_prop(sym);
381 		if (prop) {
382 			struct symbol *ds = prop_get_symbol(prop);
383 			if (ds) {
384 				sym->flags |= SYMBOL_WRITE;
385 				sym_calc_value(ds);
386 				newval.val = ds->curr.val;
387 			}
388 		}
389 		break;
390 	default:
391 		;
392 	}
393 
394 	sym->curr = newval;
395 	if (sym_is_choice(sym) && newval.tri == yes)
396 		sym->curr.val = sym_calc_choice(sym);
397 	sym_validate_range(sym);
398 
399 	if (memcmp(&oldval, &sym->curr, sizeof(oldval))) {
400 		sym_set_changed(sym);
401 		if (modules_sym == sym) {
402 			sym_set_all_changed();
403 			modules_val = modules_sym->curr.tri;
404 		}
405 	}
406 
407 	if (sym_is_choice(sym)) {
408 		struct symbol *choice_sym;
409 
410 		prop = sym_get_choice_prop(sym);
411 		expr_list_for_each_sym(prop->expr, e, choice_sym) {
412 			if ((sym->flags & SYMBOL_WRITE) &&
413 			    choice_sym->visible != no)
414 				choice_sym->flags |= SYMBOL_WRITE;
415 			if (sym->flags & SYMBOL_CHANGED)
416 				sym_set_changed(choice_sym);
417 		}
418 	}
419 
420 	if (sym->flags & SYMBOL_AUTO)
421 		sym->flags &= ~SYMBOL_WRITE;
422 }
423 
424 void sym_clear_all_valid(void)
425 {
426 	struct symbol *sym;
427 	int i;
428 
429 	for_all_symbols(i, sym)
430 		sym->flags &= ~SYMBOL_VALID;
431 	sym_add_change_count(1);
432 	if (modules_sym)
433 		sym_calc_value(modules_sym);
434 }
435 
436 void sym_set_changed(struct symbol *sym)
437 {
438 	struct property *prop;
439 
440 	sym->flags |= SYMBOL_CHANGED;
441 	for (prop = sym->prop; prop; prop = prop->next) {
442 		if (prop->menu)
443 			prop->menu->flags |= MENU_CHANGED;
444 	}
445 }
446 
447 void sym_set_all_changed(void)
448 {
449 	struct symbol *sym;
450 	int i;
451 
452 	for_all_symbols(i, sym)
453 		sym_set_changed(sym);
454 }
455 
456 bool sym_tristate_within_range(struct symbol *sym, tristate val)
457 {
458 	int type = sym_get_type(sym);
459 
460 	if (sym->visible == no)
461 		return false;
462 
463 	if (type != S_BOOLEAN && type != S_TRISTATE)
464 		return false;
465 
466 	if (type == S_BOOLEAN && val == mod)
467 		return false;
468 	if (sym->visible <= sym->rev_dep.tri)
469 		return false;
470 	if (sym_is_choice_value(sym) && sym->visible == yes)
471 		return val == yes;
472 	return val >= sym->rev_dep.tri && val <= sym->visible;
473 }
474 
475 bool sym_set_tristate_value(struct symbol *sym, tristate val)
476 {
477 	tristate oldval = sym_get_tristate_value(sym);
478 
479 	if (oldval != val && !sym_tristate_within_range(sym, val))
480 		return false;
481 
482 	if (!(sym->flags & SYMBOL_DEF_USER)) {
483 		sym->flags |= SYMBOL_DEF_USER;
484 		sym_set_changed(sym);
485 	}
486 	/*
487 	 * setting a choice value also resets the new flag of the choice
488 	 * symbol and all other choice values.
489 	 */
490 	if (sym_is_choice_value(sym) && val == yes) {
491 		struct symbol *cs = prop_get_symbol(sym_get_choice_prop(sym));
492 		struct property *prop;
493 		struct expr *e;
494 
495 		cs->def[S_DEF_USER].val = sym;
496 		cs->flags |= SYMBOL_DEF_USER;
497 		prop = sym_get_choice_prop(cs);
498 		for (e = prop->expr; e; e = e->left.expr) {
499 			if (e->right.sym->visible != no)
500 				e->right.sym->flags |= SYMBOL_DEF_USER;
501 		}
502 	}
503 
504 	sym->def[S_DEF_USER].tri = val;
505 	if (oldval != val)
506 		sym_clear_all_valid();
507 
508 	return true;
509 }
510 
511 tristate sym_toggle_tristate_value(struct symbol *sym)
512 {
513 	tristate oldval, newval;
514 
515 	oldval = newval = sym_get_tristate_value(sym);
516 	do {
517 		switch (newval) {
518 		case no:
519 			newval = mod;
520 			break;
521 		case mod:
522 			newval = yes;
523 			break;
524 		case yes:
525 			newval = no;
526 			break;
527 		}
528 		if (sym_set_tristate_value(sym, newval))
529 			break;
530 	} while (oldval != newval);
531 	return newval;
532 }
533 
534 bool sym_string_valid(struct symbol *sym, const char *str)
535 {
536 	signed char ch;
537 
538 	switch (sym->type) {
539 	case S_STRING:
540 		return true;
541 	case S_INT:
542 		ch = *str++;
543 		if (ch == '-')
544 			ch = *str++;
545 		if (!isdigit(ch))
546 			return false;
547 		if (ch == '0' && *str != 0)
548 			return false;
549 		while ((ch = *str++)) {
550 			if (!isdigit(ch))
551 				return false;
552 		}
553 		return true;
554 	case S_HEX:
555 		if (str[0] == '0' && (str[1] == 'x' || str[1] == 'X'))
556 			str += 2;
557 		ch = *str++;
558 		do {
559 			if (!isxdigit(ch))
560 				return false;
561 		} while ((ch = *str++));
562 		return true;
563 	case S_BOOLEAN:
564 	case S_TRISTATE:
565 		switch (str[0]) {
566 		case 'y': case 'Y':
567 		case 'm': case 'M':
568 		case 'n': case 'N':
569 			return true;
570 		}
571 		return false;
572 	default:
573 		return false;
574 	}
575 }
576 
577 bool sym_string_within_range(struct symbol *sym, const char *str)
578 {
579 	struct property *prop;
580 	int val;
581 
582 	switch (sym->type) {
583 	case S_STRING:
584 		return sym_string_valid(sym, str);
585 	case S_INT:
586 		if (!sym_string_valid(sym, str))
587 			return false;
588 		prop = sym_get_range_prop(sym);
589 		if (!prop)
590 			return true;
591 		val = strtol(str, NULL, 10);
592 		return val >= sym_get_range_val(prop->expr->left.sym, 10) &&
593 		       val <= sym_get_range_val(prop->expr->right.sym, 10);
594 	case S_HEX:
595 		if (!sym_string_valid(sym, str))
596 			return false;
597 		prop = sym_get_range_prop(sym);
598 		if (!prop)
599 			return true;
600 		val = strtol(str, NULL, 16);
601 		return val >= sym_get_range_val(prop->expr->left.sym, 16) &&
602 		       val <= sym_get_range_val(prop->expr->right.sym, 16);
603 	case S_BOOLEAN:
604 	case S_TRISTATE:
605 		switch (str[0]) {
606 		case 'y': case 'Y':
607 			return sym_tristate_within_range(sym, yes);
608 		case 'm': case 'M':
609 			return sym_tristate_within_range(sym, mod);
610 		case 'n': case 'N':
611 			return sym_tristate_within_range(sym, no);
612 		}
613 		return false;
614 	default:
615 		return false;
616 	}
617 }
618 
619 bool sym_set_string_value(struct symbol *sym, const char *newval)
620 {
621 	const char *oldval;
622 	char *val;
623 	int size;
624 
625 	switch (sym->type) {
626 	case S_BOOLEAN:
627 	case S_TRISTATE:
628 		switch (newval[0]) {
629 		case 'y': case 'Y':
630 			return sym_set_tristate_value(sym, yes);
631 		case 'm': case 'M':
632 			return sym_set_tristate_value(sym, mod);
633 		case 'n': case 'N':
634 			return sym_set_tristate_value(sym, no);
635 		}
636 		return false;
637 	default:
638 		;
639 	}
640 
641 	if (!sym_string_within_range(sym, newval))
642 		return false;
643 
644 	if (!(sym->flags & SYMBOL_DEF_USER)) {
645 		sym->flags |= SYMBOL_DEF_USER;
646 		sym_set_changed(sym);
647 	}
648 
649 	oldval = sym->def[S_DEF_USER].val;
650 	size = strlen(newval) + 1;
651 	if (sym->type == S_HEX && (newval[0] != '0' || (newval[1] != 'x' && newval[1] != 'X'))) {
652 		size += 2;
653 		sym->def[S_DEF_USER].val = val = malloc(size);
654 		*val++ = '0';
655 		*val++ = 'x';
656 	} else if (!oldval || strcmp(oldval, newval))
657 		sym->def[S_DEF_USER].val = val = malloc(size);
658 	else
659 		return true;
660 
661 	strcpy(val, newval);
662 	free((void *)oldval);
663 	sym_clear_all_valid();
664 
665 	return true;
666 }
667 
668 /*
669  * Find the default value associated to a symbol.
670  * For tristate symbol handle the modules=n case
671  * in which case "m" becomes "y".
672  * If the symbol does not have any default then fallback
673  * to the fixed default values.
674  */
675 const char *sym_get_string_default(struct symbol *sym)
676 {
677 	struct property *prop;
678 	struct symbol *ds;
679 	const char *str;
680 	tristate val;
681 
682 	sym_calc_visibility(sym);
683 	sym_calc_value(modules_sym);
684 	val = symbol_no.curr.tri;
685 	str = symbol_empty.curr.val;
686 
687 	/* If symbol has a default value look it up */
688 	prop = sym_get_default_prop(sym);
689 	if (prop != NULL) {
690 		switch (sym->type) {
691 		case S_BOOLEAN:
692 		case S_TRISTATE:
693 			/* The visibility may limit the value from yes => mod */
694 			val = EXPR_AND(expr_calc_value(prop->expr), prop->visible.tri);
695 			break;
696 		default:
697 			/*
698 			 * The following fails to handle the situation
699 			 * where a default value is further limited by
700 			 * the valid range.
701 			 */
702 			ds = prop_get_symbol(prop);
703 			if (ds != NULL) {
704 				sym_calc_value(ds);
705 				str = (const char *)ds->curr.val;
706 			}
707 		}
708 	}
709 
710 	/* Handle select statements */
711 	val = EXPR_OR(val, sym->rev_dep.tri);
712 
713 	/* transpose mod to yes if modules are not enabled */
714 	if (val == mod)
715 		if (!sym_is_choice_value(sym) && modules_sym->curr.tri == no)
716 			val = yes;
717 
718 	/* transpose mod to yes if type is bool */
719 	if (sym->type == S_BOOLEAN && val == mod)
720 		val = yes;
721 
722 	switch (sym->type) {
723 	case S_BOOLEAN:
724 	case S_TRISTATE:
725 		switch (val) {
726 		case no: return "n";
727 		case mod: return "m";
728 		case yes: return "y";
729 		}
730 	case S_INT:
731 	case S_HEX:
732 		return str;
733 	case S_STRING:
734 		return str;
735 	case S_OTHER:
736 	case S_UNKNOWN:
737 		break;
738 	}
739 	return "";
740 }
741 
742 const char *sym_get_string_value(struct symbol *sym)
743 {
744 	tristate val;
745 
746 	switch (sym->type) {
747 	case S_BOOLEAN:
748 	case S_TRISTATE:
749 		val = sym_get_tristate_value(sym);
750 		switch (val) {
751 		case no:
752 			return "n";
753 		case mod:
754 			return "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 struct symbol **sym_re_search(const char *pattern)
897 {
898 	struct symbol *sym, **sym_arr = NULL;
899 	int i, cnt, size;
900 	regex_t re;
901 
902 	cnt = size = 0;
903 	/* Skip if empty */
904 	if (strlen(pattern) == 0)
905 		return NULL;
906 	if (regcomp(&re, pattern, REG_EXTENDED|REG_NOSUB|REG_ICASE))
907 		return NULL;
908 
909 	for_all_symbols(i, sym) {
910 		if (sym->flags & SYMBOL_CONST || !sym->name)
911 			continue;
912 		if (regexec(&re, sym->name, 0, NULL, 0))
913 			continue;
914 		if (cnt + 1 >= size) {
915 			void *tmp = sym_arr;
916 			size += 16;
917 			sym_arr = realloc(sym_arr, size * sizeof(struct symbol *));
918 			if (!sym_arr) {
919 				free(tmp);
920 				return NULL;
921 			}
922 		}
923 		sym_calc_value(sym);
924 		sym_arr[cnt++] = sym;
925 	}
926 	if (sym_arr)
927 		sym_arr[cnt] = NULL;
928 	regfree(&re);
929 
930 	return sym_arr;
931 }
932 
933 /*
934  * When we check for recursive dependencies we use a stack to save
935  * current state so we can print out relevant info to user.
936  * The entries are located on the call stack so no need to free memory.
937  * Note inser() remove() must always match to properly clear the stack.
938  */
939 static struct dep_stack {
940 	struct dep_stack *prev, *next;
941 	struct symbol *sym;
942 	struct property *prop;
943 	struct expr *expr;
944 } *check_top;
945 
946 static void dep_stack_insert(struct dep_stack *stack, struct symbol *sym)
947 {
948 	memset(stack, 0, sizeof(*stack));
949 	if (check_top)
950 		check_top->next = stack;
951 	stack->prev = check_top;
952 	stack->sym = sym;
953 	check_top = stack;
954 }
955 
956 static void dep_stack_remove(void)
957 {
958 	check_top = check_top->prev;
959 	if (check_top)
960 		check_top->next = NULL;
961 }
962 
963 /*
964  * Called when we have detected a recursive dependency.
965  * check_top point to the top of the stact so we use
966  * the ->prev pointer to locate the bottom of the stack.
967  */
968 static void sym_check_print_recursive(struct symbol *last_sym)
969 {
970 	struct dep_stack *stack;
971 	struct symbol *sym, *next_sym;
972 	struct menu *menu = NULL;
973 	struct property *prop;
974 	struct dep_stack cv_stack;
975 
976 	if (sym_is_choice_value(last_sym)) {
977 		dep_stack_insert(&cv_stack, last_sym);
978 		last_sym = prop_get_symbol(sym_get_choice_prop(last_sym));
979 	}
980 
981 	for (stack = check_top; stack != NULL; stack = stack->prev)
982 		if (stack->sym == last_sym)
983 			break;
984 	if (!stack) {
985 		fprintf(stderr, "unexpected recursive dependency error\n");
986 		return;
987 	}
988 
989 	for (; stack; stack = stack->next) {
990 		sym = stack->sym;
991 		next_sym = stack->next ? stack->next->sym : last_sym;
992 		prop = stack->prop;
993 		if (prop == NULL)
994 			prop = stack->sym->prop;
995 
996 		/* for choice values find the menu entry (used below) */
997 		if (sym_is_choice(sym) || sym_is_choice_value(sym)) {
998 			for (prop = sym->prop; prop; prop = prop->next) {
999 				menu = prop->menu;
1000 				if (prop->menu)
1001 					break;
1002 			}
1003 		}
1004 		if (stack->sym == last_sym)
1005 			fprintf(stderr, "%s:%d:error: recursive dependency detected!\n",
1006 				prop->file->name, prop->lineno);
1007 		if (stack->expr) {
1008 			fprintf(stderr, "%s:%d:\tsymbol %s %s value contains %s\n",
1009 				prop->file->name, prop->lineno,
1010 				sym->name ? sym->name : "<choice>",
1011 				prop_get_type_name(prop->type),
1012 				next_sym->name ? next_sym->name : "<choice>");
1013 		} else if (stack->prop) {
1014 			fprintf(stderr, "%s:%d:\tsymbol %s depends on %s\n",
1015 				prop->file->name, prop->lineno,
1016 				sym->name ? sym->name : "<choice>",
1017 				next_sym->name ? next_sym->name : "<choice>");
1018 		} else if (sym_is_choice(sym)) {
1019 			fprintf(stderr, "%s:%d:\tchoice %s contains symbol %s\n",
1020 				menu->file->name, menu->lineno,
1021 				sym->name ? sym->name : "<choice>",
1022 				next_sym->name ? next_sym->name : "<choice>");
1023 		} else if (sym_is_choice_value(sym)) {
1024 			fprintf(stderr, "%s:%d:\tsymbol %s is part of choice %s\n",
1025 				menu->file->name, menu->lineno,
1026 				sym->name ? sym->name : "<choice>",
1027 				next_sym->name ? next_sym->name : "<choice>");
1028 		} else {
1029 			fprintf(stderr, "%s:%d:\tsymbol %s is selected by %s\n",
1030 				prop->file->name, prop->lineno,
1031 				sym->name ? sym->name : "<choice>",
1032 				next_sym->name ? next_sym->name : "<choice>");
1033 		}
1034 	}
1035 
1036 	if (check_top == &cv_stack)
1037 		dep_stack_remove();
1038 }
1039 
1040 static struct symbol *sym_check_expr_deps(struct expr *e)
1041 {
1042 	struct symbol *sym;
1043 
1044 	if (!e)
1045 		return NULL;
1046 	switch (e->type) {
1047 	case E_OR:
1048 	case E_AND:
1049 		sym = sym_check_expr_deps(e->left.expr);
1050 		if (sym)
1051 			return sym;
1052 		return sym_check_expr_deps(e->right.expr);
1053 	case E_NOT:
1054 		return sym_check_expr_deps(e->left.expr);
1055 	case E_EQUAL:
1056 	case E_UNEQUAL:
1057 		sym = sym_check_deps(e->left.sym);
1058 		if (sym)
1059 			return sym;
1060 		return sym_check_deps(e->right.sym);
1061 	case E_SYMBOL:
1062 		return sym_check_deps(e->left.sym);
1063 	default:
1064 		break;
1065 	}
1066 	printf("Oops! How to check %d?\n", e->type);
1067 	return NULL;
1068 }
1069 
1070 /* return NULL when dependencies are OK */
1071 static struct symbol *sym_check_sym_deps(struct symbol *sym)
1072 {
1073 	struct symbol *sym2;
1074 	struct property *prop;
1075 	struct dep_stack stack;
1076 
1077 	dep_stack_insert(&stack, sym);
1078 
1079 	sym2 = sym_check_expr_deps(sym->rev_dep.expr);
1080 	if (sym2)
1081 		goto out;
1082 
1083 	for (prop = sym->prop; prop; prop = prop->next) {
1084 		if (prop->type == P_CHOICE || prop->type == P_SELECT)
1085 			continue;
1086 		stack.prop = prop;
1087 		sym2 = sym_check_expr_deps(prop->visible.expr);
1088 		if (sym2)
1089 			break;
1090 		if (prop->type != P_DEFAULT || sym_is_choice(sym))
1091 			continue;
1092 		stack.expr = prop->expr;
1093 		sym2 = sym_check_expr_deps(prop->expr);
1094 		if (sym2)
1095 			break;
1096 		stack.expr = NULL;
1097 	}
1098 
1099 out:
1100 	dep_stack_remove();
1101 
1102 	return sym2;
1103 }
1104 
1105 static struct symbol *sym_check_choice_deps(struct symbol *choice)
1106 {
1107 	struct symbol *sym, *sym2;
1108 	struct property *prop;
1109 	struct expr *e;
1110 	struct dep_stack stack;
1111 
1112 	dep_stack_insert(&stack, choice);
1113 
1114 	prop = sym_get_choice_prop(choice);
1115 	expr_list_for_each_sym(prop->expr, e, sym)
1116 		sym->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1117 
1118 	choice->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1119 	sym2 = sym_check_sym_deps(choice);
1120 	choice->flags &= ~SYMBOL_CHECK;
1121 	if (sym2)
1122 		goto out;
1123 
1124 	expr_list_for_each_sym(prop->expr, e, sym) {
1125 		sym2 = sym_check_sym_deps(sym);
1126 		if (sym2)
1127 			break;
1128 	}
1129 out:
1130 	expr_list_for_each_sym(prop->expr, e, sym)
1131 		sym->flags &= ~SYMBOL_CHECK;
1132 
1133 	if (sym2 && sym_is_choice_value(sym2) &&
1134 	    prop_get_symbol(sym_get_choice_prop(sym2)) == choice)
1135 		sym2 = choice;
1136 
1137 	dep_stack_remove();
1138 
1139 	return sym2;
1140 }
1141 
1142 struct symbol *sym_check_deps(struct symbol *sym)
1143 {
1144 	struct symbol *sym2;
1145 	struct property *prop;
1146 
1147 	if (sym->flags & SYMBOL_CHECK) {
1148 		sym_check_print_recursive(sym);
1149 		return sym;
1150 	}
1151 	if (sym->flags & SYMBOL_CHECKED)
1152 		return NULL;
1153 
1154 	if (sym_is_choice_value(sym)) {
1155 		struct dep_stack stack;
1156 
1157 		/* for choice groups start the check with main choice symbol */
1158 		dep_stack_insert(&stack, sym);
1159 		prop = sym_get_choice_prop(sym);
1160 		sym2 = sym_check_deps(prop_get_symbol(prop));
1161 		dep_stack_remove();
1162 	} else if (sym_is_choice(sym)) {
1163 		sym2 = sym_check_choice_deps(sym);
1164 	} else {
1165 		sym->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1166 		sym2 = sym_check_sym_deps(sym);
1167 		sym->flags &= ~SYMBOL_CHECK;
1168 	}
1169 
1170 	if (sym2 && sym2 == sym)
1171 		sym2 = NULL;
1172 
1173 	return sym2;
1174 }
1175 
1176 struct property *prop_alloc(enum prop_type type, struct symbol *sym)
1177 {
1178 	struct property *prop;
1179 	struct property **propp;
1180 
1181 	prop = malloc(sizeof(*prop));
1182 	memset(prop, 0, sizeof(*prop));
1183 	prop->type = type;
1184 	prop->sym = sym;
1185 	prop->file = current_file;
1186 	prop->lineno = zconf_lineno();
1187 
1188 	/* append property to the prop list of symbol */
1189 	if (sym) {
1190 		for (propp = &sym->prop; *propp; propp = &(*propp)->next)
1191 			;
1192 		*propp = prop;
1193 	}
1194 
1195 	return prop;
1196 }
1197 
1198 struct symbol *prop_get_symbol(struct property *prop)
1199 {
1200 	if (prop->expr && (prop->expr->type == E_SYMBOL ||
1201 			   prop->expr->type == E_LIST))
1202 		return prop->expr->left.sym;
1203 	return NULL;
1204 }
1205 
1206 const char *prop_get_type_name(enum prop_type type)
1207 {
1208 	switch (type) {
1209 	case P_PROMPT:
1210 		return "prompt";
1211 	case P_ENV:
1212 		return "env";
1213 	case P_COMMENT:
1214 		return "comment";
1215 	case P_MENU:
1216 		return "menu";
1217 	case P_DEFAULT:
1218 		return "default";
1219 	case P_CHOICE:
1220 		return "choice";
1221 	case P_SELECT:
1222 		return "select";
1223 	case P_RANGE:
1224 		return "range";
1225 	case P_SYMBOL:
1226 		return "symbol";
1227 	case P_UNKNOWN:
1228 		break;
1229 	}
1230 	return "unknown";
1231 }
1232 
1233 static void prop_add_env(const char *env)
1234 {
1235 	struct symbol *sym, *sym2;
1236 	struct property *prop;
1237 	char *p;
1238 
1239 	sym = current_entry->sym;
1240 	sym->flags |= SYMBOL_AUTO;
1241 	for_all_properties(sym, prop, P_ENV) {
1242 		sym2 = prop_get_symbol(prop);
1243 		if (strcmp(sym2->name, env))
1244 			menu_warn(current_entry, "redefining environment symbol from %s",
1245 				  sym2->name);
1246 		return;
1247 	}
1248 
1249 	prop = prop_alloc(P_ENV, sym);
1250 	prop->expr = expr_alloc_symbol(sym_lookup(env, SYMBOL_CONST));
1251 
1252 	sym_env_list = expr_alloc_one(E_LIST, sym_env_list);
1253 	sym_env_list->right.sym = sym;
1254 
1255 	p = getenv(env);
1256 	if (p)
1257 		sym_add_default(sym, p);
1258 	else
1259 		menu_warn(current_entry, "environment variable %s undefined", env);
1260 }
1261