1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2002 Roman Zippel <zippel@linux-m68k.org>
4 */
5
6#include <sys/types.h>
7#include <ctype.h>
8#include <stdlib.h>
9#include <string.h>
10#include <regex.h>
11
12#include "internal.h"
13#include "lkc.h"
14
15struct symbol symbol_yes = {
16	.name = "y",
17	.type = S_TRISTATE,
18	.curr = { "y", yes },
19	.menus = LIST_HEAD_INIT(symbol_yes.menus),
20	.flags = SYMBOL_CONST|SYMBOL_VALID,
21};
22
23struct symbol symbol_mod = {
24	.name = "m",
25	.type = S_TRISTATE,
26	.curr = { "m", mod },
27	.menus = LIST_HEAD_INIT(symbol_mod.menus),
28	.flags = SYMBOL_CONST|SYMBOL_VALID,
29};
30
31struct symbol symbol_no = {
32	.name = "n",
33	.type = S_TRISTATE,
34	.curr = { "n", no },
35	.menus = LIST_HEAD_INIT(symbol_no.menus),
36	.flags = SYMBOL_CONST|SYMBOL_VALID,
37};
38
39struct symbol *modules_sym;
40static tristate modules_val;
41static int sym_warnings;
42
43enum symbol_type sym_get_type(struct symbol *sym)
44{
45	enum symbol_type type = sym->type;
46
47	if (type == S_TRISTATE) {
48		if (sym_is_choice_value(sym) && sym->visible == yes)
49			type = S_BOOLEAN;
50		else if (modules_val == no)
51			type = S_BOOLEAN;
52	}
53	return type;
54}
55
56const char *sym_type_name(enum symbol_type type)
57{
58	switch (type) {
59	case S_BOOLEAN:
60		return "bool";
61	case S_TRISTATE:
62		return "tristate";
63	case S_INT:
64		return "integer";
65	case S_HEX:
66		return "hex";
67	case S_STRING:
68		return "string";
69	case S_UNKNOWN:
70		return "unknown";
71	}
72	return "???";
73}
74
75struct property *sym_get_choice_prop(struct symbol *sym)
76{
77	struct property *prop;
78
79	for_all_choices(sym, prop)
80		return prop;
81	return NULL;
82}
83
84/**
85 * sym_get_choice_menu - get the parent choice menu if present
86 *
87 * @sym: a symbol pointer
88 *
89 * Return: a choice menu if this function is called against a choice member.
90 */
91struct menu *sym_get_choice_menu(struct symbol *sym)
92{
93	struct menu *menu = NULL;
94	struct menu *m;
95
96	/*
97	 * Choice members must have a prompt. Find a menu entry with a prompt,
98	 * and assume it resides inside a choice block.
99	 */
100	list_for_each_entry(m, &sym->menus, link)
101		if (m->prompt) {
102			menu = m;
103			break;
104		}
105
106	if (!menu)
107		return NULL;
108
109	do {
110		menu = menu->parent;
111	} while (menu && !menu->sym);
112
113	if (menu && menu->sym && sym_is_choice(menu->sym))
114		return menu;
115
116	return NULL;
117}
118
119static struct property *sym_get_default_prop(struct symbol *sym)
120{
121	struct property *prop;
122
123	for_all_defaults(sym, prop) {
124		prop->visible.tri = expr_calc_value(prop->visible.expr);
125		if (prop->visible.tri != no)
126			return prop;
127	}
128	return NULL;
129}
130
131struct property *sym_get_range_prop(struct symbol *sym)
132{
133	struct property *prop;
134
135	for_all_properties(sym, prop, P_RANGE) {
136		prop->visible.tri = expr_calc_value(prop->visible.expr);
137		if (prop->visible.tri != no)
138			return prop;
139	}
140	return NULL;
141}
142
143static long long sym_get_range_val(struct symbol *sym, int base)
144{
145	sym_calc_value(sym);
146	switch (sym->type) {
147	case S_INT:
148		base = 10;
149		break;
150	case S_HEX:
151		base = 16;
152		break;
153	default:
154		break;
155	}
156	return strtoll(sym->curr.val, NULL, base);
157}
158
159static void sym_validate_range(struct symbol *sym)
160{
161	struct property *prop;
162	struct symbol *range_sym;
163	int base;
164	long long val, val2;
165
166	switch (sym->type) {
167	case S_INT:
168		base = 10;
169		break;
170	case S_HEX:
171		base = 16;
172		break;
173	default:
174		return;
175	}
176	prop = sym_get_range_prop(sym);
177	if (!prop)
178		return;
179	val = strtoll(sym->curr.val, NULL, base);
180	range_sym = prop->expr->left.sym;
181	val2 = sym_get_range_val(range_sym, base);
182	if (val >= val2) {
183		range_sym = prop->expr->right.sym;
184		val2 = sym_get_range_val(range_sym, base);
185		if (val <= val2)
186			return;
187	}
188	sym->curr.val = range_sym->curr.val;
189}
190
191static void sym_set_changed(struct symbol *sym)
192{
193	struct menu *menu;
194
195	sym->flags |= SYMBOL_CHANGED;
196	list_for_each_entry(menu, &sym->menus, link)
197		menu->flags |= MENU_CHANGED;
198}
199
200static void sym_set_all_changed(void)
201{
202	struct symbol *sym;
203
204	for_all_symbols(sym)
205		sym_set_changed(sym);
206}
207
208static void sym_calc_visibility(struct symbol *sym)
209{
210	struct property *prop;
211	struct symbol *choice_sym = NULL;
212	tristate tri;
213
214	/* any prompt visible? */
215	tri = no;
216
217	if (sym_is_choice_value(sym))
218		choice_sym = prop_get_symbol(sym_get_choice_prop(sym));
219
220	for_all_prompts(sym, prop) {
221		prop->visible.tri = expr_calc_value(prop->visible.expr);
222		/*
223		 * Tristate choice_values with visibility 'mod' are
224		 * not visible if the corresponding choice's value is
225		 * 'yes'.
226		 */
227		if (choice_sym && sym->type == S_TRISTATE &&
228		    prop->visible.tri == mod && choice_sym->curr.tri == yes)
229			prop->visible.tri = no;
230
231		tri = EXPR_OR(tri, prop->visible.tri);
232	}
233	if (tri == mod && (sym->type != S_TRISTATE || modules_val == no))
234		tri = yes;
235	if (sym->visible != tri) {
236		sym->visible = tri;
237		sym_set_changed(sym);
238	}
239	if (sym_is_choice_value(sym))
240		return;
241	/* defaulting to "yes" if no explicit "depends on" are given */
242	tri = yes;
243	if (sym->dir_dep.expr)
244		tri = expr_calc_value(sym->dir_dep.expr);
245	if (tri == mod && sym_get_type(sym) == S_BOOLEAN)
246		tri = yes;
247	if (sym->dir_dep.tri != tri) {
248		sym->dir_dep.tri = tri;
249		sym_set_changed(sym);
250	}
251	tri = no;
252	if (sym->rev_dep.expr)
253		tri = expr_calc_value(sym->rev_dep.expr);
254	if (tri == mod && sym_get_type(sym) == S_BOOLEAN)
255		tri = yes;
256	if (sym->rev_dep.tri != tri) {
257		sym->rev_dep.tri = tri;
258		sym_set_changed(sym);
259	}
260	tri = no;
261	if (sym->implied.expr)
262		tri = expr_calc_value(sym->implied.expr);
263	if (tri == mod && sym_get_type(sym) == S_BOOLEAN)
264		tri = yes;
265	if (sym->implied.tri != tri) {
266		sym->implied.tri = tri;
267		sym_set_changed(sym);
268	}
269}
270
271/*
272 * Find the default symbol for a choice.
273 * First try the default values for the choice symbol
274 * Next locate the first visible choice value
275 * Return NULL if none was found
276 */
277struct symbol *sym_choice_default(struct symbol *sym)
278{
279	struct symbol *def_sym;
280	struct property *prop;
281	struct expr *e;
282
283	/* any of the defaults visible? */
284	for_all_defaults(sym, prop) {
285		prop->visible.tri = expr_calc_value(prop->visible.expr);
286		if (prop->visible.tri == no)
287			continue;
288		def_sym = prop_get_symbol(prop);
289		if (def_sym->visible != no)
290			return def_sym;
291	}
292
293	/* just get the first visible value */
294	prop = sym_get_choice_prop(sym);
295	expr_list_for_each_sym(prop->expr, e, def_sym)
296		if (def_sym->visible != no)
297			return def_sym;
298
299	/* failed to locate any defaults */
300	return NULL;
301}
302
303static struct symbol *sym_calc_choice(struct symbol *sym)
304{
305	struct symbol *def_sym;
306	struct property *prop;
307	struct expr *e;
308	int flags;
309
310	/* first calculate all choice values' visibilities */
311	flags = sym->flags;
312	prop = sym_get_choice_prop(sym);
313	expr_list_for_each_sym(prop->expr, e, def_sym) {
314		sym_calc_visibility(def_sym);
315		if (def_sym->visible != no)
316			flags &= def_sym->flags;
317	}
318
319	sym->flags &= flags | ~SYMBOL_DEF_USER;
320
321	/* is the user choice visible? */
322	def_sym = sym->def[S_DEF_USER].val;
323	if (def_sym && def_sym->visible != no)
324		return def_sym;
325
326	def_sym = sym_choice_default(sym);
327
328	if (def_sym == NULL)
329		/* no choice? reset tristate value */
330		sym->curr.tri = no;
331
332	return def_sym;
333}
334
335static void sym_warn_unmet_dep(struct symbol *sym)
336{
337	struct gstr gs = str_new();
338
339	str_printf(&gs,
340		   "\nWARNING: unmet direct dependencies detected for %s\n",
341		   sym->name);
342	str_printf(&gs,
343		   "  Depends on [%c]: ",
344		   sym->dir_dep.tri == mod ? 'm' : 'n');
345	expr_gstr_print(sym->dir_dep.expr, &gs);
346	str_printf(&gs, "\n");
347
348	expr_gstr_print_revdep(sym->rev_dep.expr, &gs, yes,
349			       "  Selected by [y]:\n");
350	expr_gstr_print_revdep(sym->rev_dep.expr, &gs, mod,
351			       "  Selected by [m]:\n");
352
353	fputs(str_get(&gs), stderr);
354	sym_warnings++;
355}
356
357bool sym_dep_errors(void)
358{
359	if (sym_warnings)
360		return getenv("KCONFIG_WERROR");
361	return false;
362}
363
364void sym_calc_value(struct symbol *sym)
365{
366	struct symbol_value newval, oldval;
367	struct property *prop;
368	struct expr *e;
369
370	if (!sym)
371		return;
372
373	if (sym->flags & SYMBOL_VALID)
374		return;
375
376	if (sym_is_choice_value(sym) &&
377	    sym->flags & SYMBOL_NEED_SET_CHOICE_VALUES) {
378		sym->flags &= ~SYMBOL_NEED_SET_CHOICE_VALUES;
379		prop = sym_get_choice_prop(sym);
380		sym_calc_value(prop_get_symbol(prop));
381	}
382
383	sym->flags |= SYMBOL_VALID;
384
385	oldval = sym->curr;
386
387	newval.tri = no;
388
389	switch (sym->type) {
390	case S_INT:
391		newval.val = "0";
392		break;
393	case S_HEX:
394		newval.val = "0x0";
395		break;
396	case S_STRING:
397		newval.val = "";
398		break;
399	case S_BOOLEAN:
400	case S_TRISTATE:
401		newval.val = "n";
402		break;
403	default:
404		sym->curr.val = sym->name;
405		sym->curr.tri = no;
406		return;
407	}
408	sym->flags &= ~SYMBOL_WRITE;
409
410	sym_calc_visibility(sym);
411
412	if (sym->visible != no)
413		sym->flags |= SYMBOL_WRITE;
414
415	/* set default if recursively called */
416	sym->curr = newval;
417
418	switch (sym_get_type(sym)) {
419	case S_BOOLEAN:
420	case S_TRISTATE:
421		if (sym_is_choice_value(sym) && sym->visible == yes) {
422			prop = sym_get_choice_prop(sym);
423			newval.tri = (prop_get_symbol(prop)->curr.val == sym) ? yes : no;
424		} else {
425			if (sym->visible != no) {
426				/* if the symbol is visible use the user value
427				 * if available, otherwise try the default value
428				 */
429				if (sym_has_value(sym)) {
430					newval.tri = EXPR_AND(sym->def[S_DEF_USER].tri,
431							      sym->visible);
432					goto calc_newval;
433				}
434			}
435			if (sym->rev_dep.tri != no)
436				sym->flags |= SYMBOL_WRITE;
437			if (!sym_is_choice(sym)) {
438				prop = sym_get_default_prop(sym);
439				if (prop) {
440					newval.tri = EXPR_AND(expr_calc_value(prop->expr),
441							      prop->visible.tri);
442					if (newval.tri != no)
443						sym->flags |= SYMBOL_WRITE;
444				}
445				if (sym->implied.tri != no) {
446					sym->flags |= SYMBOL_WRITE;
447					newval.tri = EXPR_OR(newval.tri, sym->implied.tri);
448					newval.tri = EXPR_AND(newval.tri,
449							      sym->dir_dep.tri);
450				}
451			}
452		calc_newval:
453			if (sym->dir_dep.tri < sym->rev_dep.tri)
454				sym_warn_unmet_dep(sym);
455			newval.tri = EXPR_OR(newval.tri, sym->rev_dep.tri);
456		}
457		if (newval.tri == mod && sym_get_type(sym) == S_BOOLEAN)
458			newval.tri = yes;
459		break;
460	case S_STRING:
461	case S_HEX:
462	case S_INT:
463		if (sym->visible != no && sym_has_value(sym)) {
464			newval.val = sym->def[S_DEF_USER].val;
465			break;
466		}
467		prop = sym_get_default_prop(sym);
468		if (prop) {
469			struct symbol *ds = prop_get_symbol(prop);
470			if (ds) {
471				sym->flags |= SYMBOL_WRITE;
472				sym_calc_value(ds);
473				newval.val = ds->curr.val;
474			}
475		}
476		break;
477	default:
478		;
479	}
480
481	sym->curr = newval;
482	if (sym_is_choice(sym) && newval.tri == yes)
483		sym->curr.val = sym_calc_choice(sym);
484	sym_validate_range(sym);
485
486	if (memcmp(&oldval, &sym->curr, sizeof(oldval))) {
487		sym_set_changed(sym);
488		if (modules_sym == sym) {
489			sym_set_all_changed();
490			modules_val = modules_sym->curr.tri;
491		}
492	}
493
494	if (sym_is_choice(sym)) {
495		struct symbol *choice_sym;
496
497		prop = sym_get_choice_prop(sym);
498		expr_list_for_each_sym(prop->expr, e, choice_sym) {
499			if ((sym->flags & SYMBOL_WRITE) &&
500			    choice_sym->visible != no)
501				choice_sym->flags |= SYMBOL_WRITE;
502			if (sym->flags & SYMBOL_CHANGED)
503				sym_set_changed(choice_sym);
504		}
505
506		sym->flags &= ~SYMBOL_WRITE;
507	}
508
509	if (sym->flags & SYMBOL_NEED_SET_CHOICE_VALUES)
510		set_all_choice_values(sym);
511}
512
513void sym_clear_all_valid(void)
514{
515	struct symbol *sym;
516
517	for_all_symbols(sym)
518		sym->flags &= ~SYMBOL_VALID;
519	conf_set_changed(true);
520	sym_calc_value(modules_sym);
521}
522
523bool sym_tristate_within_range(struct symbol *sym, tristate val)
524{
525	int type = sym_get_type(sym);
526
527	if (sym->visible == no)
528		return false;
529
530	if (type != S_BOOLEAN && type != S_TRISTATE)
531		return false;
532
533	if (type == S_BOOLEAN && val == mod)
534		return false;
535	if (sym->visible <= sym->rev_dep.tri)
536		return false;
537	if (sym_is_choice_value(sym) && sym->visible == yes)
538		return val == yes;
539	return val >= sym->rev_dep.tri && val <= sym->visible;
540}
541
542bool sym_set_tristate_value(struct symbol *sym, tristate val)
543{
544	tristate oldval = sym_get_tristate_value(sym);
545
546	if (oldval != val && !sym_tristate_within_range(sym, val))
547		return false;
548
549	if (!(sym->flags & SYMBOL_DEF_USER)) {
550		sym->flags |= SYMBOL_DEF_USER;
551		sym_set_changed(sym);
552	}
553	/*
554	 * setting a choice value also resets the new flag of the choice
555	 * symbol and all other choice values.
556	 */
557	if (sym_is_choice_value(sym) && val == yes) {
558		struct symbol *cs = prop_get_symbol(sym_get_choice_prop(sym));
559		struct property *prop;
560		struct expr *e;
561
562		cs->def[S_DEF_USER].val = sym;
563		cs->flags |= SYMBOL_DEF_USER;
564		prop = sym_get_choice_prop(cs);
565		for (e = prop->expr; e; e = e->left.expr) {
566			if (e->right.sym->visible != no)
567				e->right.sym->flags |= SYMBOL_DEF_USER;
568		}
569	}
570
571	sym->def[S_DEF_USER].tri = val;
572	if (oldval != val)
573		sym_clear_all_valid();
574
575	return true;
576}
577
578tristate sym_toggle_tristate_value(struct symbol *sym)
579{
580	tristate oldval, newval;
581
582	oldval = newval = sym_get_tristate_value(sym);
583	do {
584		switch (newval) {
585		case no:
586			newval = mod;
587			break;
588		case mod:
589			newval = yes;
590			break;
591		case yes:
592			newval = no;
593			break;
594		}
595		if (sym_set_tristate_value(sym, newval))
596			break;
597	} while (oldval != newval);
598	return newval;
599}
600
601bool sym_string_valid(struct symbol *sym, const char *str)
602{
603	signed char ch;
604
605	switch (sym->type) {
606	case S_STRING:
607		return true;
608	case S_INT:
609		ch = *str++;
610		if (ch == '-')
611			ch = *str++;
612		if (!isdigit(ch))
613			return false;
614		if (ch == '0' && *str != 0)
615			return false;
616		while ((ch = *str++)) {
617			if (!isdigit(ch))
618				return false;
619		}
620		return true;
621	case S_HEX:
622		if (str[0] == '0' && (str[1] == 'x' || str[1] == 'X'))
623			str += 2;
624		ch = *str++;
625		do {
626			if (!isxdigit(ch))
627				return false;
628		} while ((ch = *str++));
629		return true;
630	case S_BOOLEAN:
631	case S_TRISTATE:
632		switch (str[0]) {
633		case 'y': case 'Y':
634		case 'm': case 'M':
635		case 'n': case 'N':
636			return true;
637		}
638		return false;
639	default:
640		return false;
641	}
642}
643
644bool sym_string_within_range(struct symbol *sym, const char *str)
645{
646	struct property *prop;
647	long long val;
648
649	switch (sym->type) {
650	case S_STRING:
651		return sym_string_valid(sym, str);
652	case S_INT:
653		if (!sym_string_valid(sym, str))
654			return false;
655		prop = sym_get_range_prop(sym);
656		if (!prop)
657			return true;
658		val = strtoll(str, NULL, 10);
659		return val >= sym_get_range_val(prop->expr->left.sym, 10) &&
660		       val <= sym_get_range_val(prop->expr->right.sym, 10);
661	case S_HEX:
662		if (!sym_string_valid(sym, str))
663			return false;
664		prop = sym_get_range_prop(sym);
665		if (!prop)
666			return true;
667		val = strtoll(str, NULL, 16);
668		return val >= sym_get_range_val(prop->expr->left.sym, 16) &&
669		       val <= sym_get_range_val(prop->expr->right.sym, 16);
670	case S_BOOLEAN:
671	case S_TRISTATE:
672		switch (str[0]) {
673		case 'y': case 'Y':
674			return sym_tristate_within_range(sym, yes);
675		case 'm': case 'M':
676			return sym_tristate_within_range(sym, mod);
677		case 'n': case 'N':
678			return sym_tristate_within_range(sym, no);
679		}
680		return false;
681	default:
682		return false;
683	}
684}
685
686bool sym_set_string_value(struct symbol *sym, const char *newval)
687{
688	const char *oldval;
689	char *val;
690	int size;
691
692	switch (sym->type) {
693	case S_BOOLEAN:
694	case S_TRISTATE:
695		switch (newval[0]) {
696		case 'y': case 'Y':
697			return sym_set_tristate_value(sym, yes);
698		case 'm': case 'M':
699			return sym_set_tristate_value(sym, mod);
700		case 'n': case 'N':
701			return sym_set_tristate_value(sym, no);
702		}
703		return false;
704	default:
705		;
706	}
707
708	if (!sym_string_within_range(sym, newval))
709		return false;
710
711	if (!(sym->flags & SYMBOL_DEF_USER)) {
712		sym->flags |= SYMBOL_DEF_USER;
713		sym_set_changed(sym);
714	}
715
716	oldval = sym->def[S_DEF_USER].val;
717	size = strlen(newval) + 1;
718	if (sym->type == S_HEX && (newval[0] != '0' || (newval[1] != 'x' && newval[1] != 'X'))) {
719		size += 2;
720		sym->def[S_DEF_USER].val = val = xmalloc(size);
721		*val++ = '0';
722		*val++ = 'x';
723	} else if (!oldval || strcmp(oldval, newval))
724		sym->def[S_DEF_USER].val = val = xmalloc(size);
725	else
726		return true;
727
728	strcpy(val, newval);
729	free((void *)oldval);
730	sym_clear_all_valid();
731
732	return true;
733}
734
735/*
736 * Find the default value associated to a symbol.
737 * For tristate symbol handle the modules=n case
738 * in which case "m" becomes "y".
739 * If the symbol does not have any default then fallback
740 * to the fixed default values.
741 */
742const char *sym_get_string_default(struct symbol *sym)
743{
744	struct property *prop;
745	struct symbol *ds;
746	const char *str = "";
747	tristate val;
748
749	sym_calc_visibility(sym);
750	sym_calc_value(modules_sym);
751	val = symbol_no.curr.tri;
752
753	/* If symbol has a default value look it up */
754	prop = sym_get_default_prop(sym);
755	if (prop != NULL) {
756		switch (sym->type) {
757		case S_BOOLEAN:
758		case S_TRISTATE:
759			/* The visibility may limit the value from yes => mod */
760			val = EXPR_AND(expr_calc_value(prop->expr), prop->visible.tri);
761			break;
762		default:
763			/*
764			 * The following fails to handle the situation
765			 * where a default value is further limited by
766			 * the valid range.
767			 */
768			ds = prop_get_symbol(prop);
769			if (ds != NULL) {
770				sym_calc_value(ds);
771				str = (const char *)ds->curr.val;
772			}
773		}
774	}
775
776	/* Handle select statements */
777	val = EXPR_OR(val, sym->rev_dep.tri);
778
779	/* transpose mod to yes if modules are not enabled */
780	if (val == mod)
781		if (!sym_is_choice_value(sym) && modules_sym->curr.tri == no)
782			val = yes;
783
784	/* transpose mod to yes if type is bool */
785	if (sym->type == S_BOOLEAN && val == mod)
786		val = yes;
787
788	/* adjust the default value if this symbol is implied by another */
789	if (val < sym->implied.tri)
790		val = sym->implied.tri;
791
792	switch (sym->type) {
793	case S_BOOLEAN:
794	case S_TRISTATE:
795		switch (val) {
796		case no: return "n";
797		case mod: return "m";
798		case yes: return "y";
799		}
800	case S_INT:
801		if (!str[0])
802			str = "0";
803		break;
804	case S_HEX:
805		if (!str[0])
806			str = "0x0";
807		break;
808	default:
809		break;
810	}
811	return str;
812}
813
814const char *sym_get_string_value(struct symbol *sym)
815{
816	tristate val;
817
818	switch (sym->type) {
819	case S_BOOLEAN:
820	case S_TRISTATE:
821		val = sym_get_tristate_value(sym);
822		switch (val) {
823		case no:
824			return "n";
825		case mod:
826			return "m";
827		case yes:
828			return "y";
829		}
830		break;
831	default:
832		;
833	}
834	return (const char *)sym->curr.val;
835}
836
837bool sym_is_changeable(struct symbol *sym)
838{
839	return sym->visible > sym->rev_dep.tri;
840}
841
842HASHTABLE_DEFINE(sym_hashtable, SYMBOL_HASHSIZE);
843
844struct symbol *sym_lookup(const char *name, int flags)
845{
846	struct symbol *symbol;
847	char *new_name;
848	int hash;
849
850	if (name) {
851		if (name[0] && !name[1]) {
852			switch (name[0]) {
853			case 'y': return &symbol_yes;
854			case 'm': return &symbol_mod;
855			case 'n': return &symbol_no;
856			}
857		}
858		hash = strhash(name);
859
860		hash_for_each_possible(sym_hashtable, symbol, node, hash) {
861			if (symbol->name &&
862			    !strcmp(symbol->name, name) &&
863			    (flags ? symbol->flags & flags
864				   : !(symbol->flags & SYMBOL_CONST)))
865				return symbol;
866		}
867		new_name = xstrdup(name);
868	} else {
869		new_name = NULL;
870		hash = 0;
871	}
872
873	symbol = xmalloc(sizeof(*symbol));
874	memset(symbol, 0, sizeof(*symbol));
875	symbol->name = new_name;
876	symbol->type = S_UNKNOWN;
877	symbol->flags = flags;
878	INIT_LIST_HEAD(&symbol->menus);
879
880	hash_add(sym_hashtable, &symbol->node, hash);
881
882	return symbol;
883}
884
885struct symbol *sym_find(const char *name)
886{
887	struct symbol *symbol = NULL;
888	int hash = 0;
889
890	if (!name)
891		return NULL;
892
893	if (name[0] && !name[1]) {
894		switch (name[0]) {
895		case 'y': return &symbol_yes;
896		case 'm': return &symbol_mod;
897		case 'n': return &symbol_no;
898		}
899	}
900	hash = strhash(name);
901
902	hash_for_each_possible(sym_hashtable, symbol, node, hash) {
903		if (symbol->name &&
904		    !strcmp(symbol->name, name) &&
905		    !(symbol->flags & SYMBOL_CONST))
906				break;
907	}
908
909	return symbol;
910}
911
912struct sym_match {
913	struct symbol	*sym;
914	off_t		so, eo;
915};
916
917/* Compare matched symbols as thus:
918 * - first, symbols that match exactly
919 * - then, alphabetical sort
920 */
921static int sym_rel_comp(const void *sym1, const void *sym2)
922{
923	const struct sym_match *s1 = sym1;
924	const struct sym_match *s2 = sym2;
925	int exact1, exact2;
926
927	/* Exact match:
928	 * - if matched length on symbol s1 is the length of that symbol,
929	 *   then this symbol should come first;
930	 * - if matched length on symbol s2 is the length of that symbol,
931	 *   then this symbol should come first.
932	 * Note: since the search can be a regexp, both symbols may match
933	 * exactly; if this is the case, we can't decide which comes first,
934	 * and we fallback to sorting alphabetically.
935	 */
936	exact1 = (s1->eo - s1->so) == strlen(s1->sym->name);
937	exact2 = (s2->eo - s2->so) == strlen(s2->sym->name);
938	if (exact1 && !exact2)
939		return -1;
940	if (!exact1 && exact2)
941		return 1;
942
943	/* As a fallback, sort symbols alphabetically */
944	return strcmp(s1->sym->name, s2->sym->name);
945}
946
947struct symbol **sym_re_search(const char *pattern)
948{
949	struct symbol *sym, **sym_arr = NULL;
950	struct sym_match *sym_match_arr = NULL;
951	int i, cnt, size;
952	regex_t re;
953	regmatch_t match[1];
954
955	cnt = size = 0;
956	/* Skip if empty */
957	if (strlen(pattern) == 0)
958		return NULL;
959	if (regcomp(&re, pattern, REG_EXTENDED|REG_ICASE))
960		return NULL;
961
962	for_all_symbols(sym) {
963		if (sym->flags & SYMBOL_CONST || !sym->name)
964			continue;
965		if (regexec(&re, sym->name, 1, match, 0))
966			continue;
967		if (cnt >= size) {
968			void *tmp;
969			size += 16;
970			tmp = realloc(sym_match_arr, size * sizeof(struct sym_match));
971			if (!tmp)
972				goto sym_re_search_free;
973			sym_match_arr = tmp;
974		}
975		sym_calc_value(sym);
976		/* As regexec returned 0, we know we have a match, so
977		 * we can use match[0].rm_[se]o without further checks
978		 */
979		sym_match_arr[cnt].so = match[0].rm_so;
980		sym_match_arr[cnt].eo = match[0].rm_eo;
981		sym_match_arr[cnt++].sym = sym;
982	}
983	if (sym_match_arr) {
984		qsort(sym_match_arr, cnt, sizeof(struct sym_match), sym_rel_comp);
985		sym_arr = malloc((cnt+1) * sizeof(struct symbol *));
986		if (!sym_arr)
987			goto sym_re_search_free;
988		for (i = 0; i < cnt; i++)
989			sym_arr[i] = sym_match_arr[i].sym;
990		sym_arr[cnt] = NULL;
991	}
992sym_re_search_free:
993	/* sym_match_arr can be NULL if no match, but free(NULL) is OK */
994	free(sym_match_arr);
995	regfree(&re);
996
997	return sym_arr;
998}
999
1000/*
1001 * When we check for recursive dependencies we use a stack to save
1002 * current state so we can print out relevant info to user.
1003 * The entries are located on the call stack so no need to free memory.
1004 * Note insert() remove() must always match to properly clear the stack.
1005 */
1006static struct dep_stack {
1007	struct dep_stack *prev, *next;
1008	struct symbol *sym;
1009	struct property *prop;
1010	struct expr **expr;
1011} *check_top;
1012
1013static void dep_stack_insert(struct dep_stack *stack, struct symbol *sym)
1014{
1015	memset(stack, 0, sizeof(*stack));
1016	if (check_top)
1017		check_top->next = stack;
1018	stack->prev = check_top;
1019	stack->sym = sym;
1020	check_top = stack;
1021}
1022
1023static void dep_stack_remove(void)
1024{
1025	check_top = check_top->prev;
1026	if (check_top)
1027		check_top->next = NULL;
1028}
1029
1030/*
1031 * Called when we have detected a recursive dependency.
1032 * check_top point to the top of the stact so we use
1033 * the ->prev pointer to locate the bottom of the stack.
1034 */
1035static void sym_check_print_recursive(struct symbol *last_sym)
1036{
1037	struct dep_stack *stack;
1038	struct symbol *sym, *next_sym;
1039	struct menu *menu = NULL;
1040	struct property *prop;
1041	struct dep_stack cv_stack;
1042
1043	if (sym_is_choice_value(last_sym)) {
1044		dep_stack_insert(&cv_stack, last_sym);
1045		last_sym = prop_get_symbol(sym_get_choice_prop(last_sym));
1046	}
1047
1048	for (stack = check_top; stack != NULL; stack = stack->prev)
1049		if (stack->sym == last_sym)
1050			break;
1051	if (!stack) {
1052		fprintf(stderr, "unexpected recursive dependency error\n");
1053		return;
1054	}
1055
1056	for (; stack; stack = stack->next) {
1057		sym = stack->sym;
1058		next_sym = stack->next ? stack->next->sym : last_sym;
1059		prop = stack->prop;
1060		if (prop == NULL)
1061			prop = stack->sym->prop;
1062
1063		/* for choice values find the menu entry (used below) */
1064		if (sym_is_choice(sym) || sym_is_choice_value(sym)) {
1065			for (prop = sym->prop; prop; prop = prop->next) {
1066				menu = prop->menu;
1067				if (prop->menu)
1068					break;
1069			}
1070		}
1071		if (stack->sym == last_sym)
1072			fprintf(stderr, "%s:%d:error: recursive dependency detected!\n",
1073				prop->filename, prop->lineno);
1074
1075		if (sym_is_choice(sym)) {
1076			fprintf(stderr, "%s:%d:\tchoice %s contains symbol %s\n",
1077				menu->filename, menu->lineno,
1078				sym->name ? sym->name : "<choice>",
1079				next_sym->name ? next_sym->name : "<choice>");
1080		} else if (sym_is_choice_value(sym)) {
1081			fprintf(stderr, "%s:%d:\tsymbol %s is part of choice %s\n",
1082				menu->filename, menu->lineno,
1083				sym->name ? sym->name : "<choice>",
1084				next_sym->name ? next_sym->name : "<choice>");
1085		} else if (stack->expr == &sym->dir_dep.expr) {
1086			fprintf(stderr, "%s:%d:\tsymbol %s depends on %s\n",
1087				prop->filename, prop->lineno,
1088				sym->name ? sym->name : "<choice>",
1089				next_sym->name ? next_sym->name : "<choice>");
1090		} else if (stack->expr == &sym->rev_dep.expr) {
1091			fprintf(stderr, "%s:%d:\tsymbol %s is selected by %s\n",
1092				prop->filename, prop->lineno,
1093				sym->name ? sym->name : "<choice>",
1094				next_sym->name ? next_sym->name : "<choice>");
1095		} else if (stack->expr == &sym->implied.expr) {
1096			fprintf(stderr, "%s:%d:\tsymbol %s is implied by %s\n",
1097				prop->filename, prop->lineno,
1098				sym->name ? sym->name : "<choice>",
1099				next_sym->name ? next_sym->name : "<choice>");
1100		} else if (stack->expr) {
1101			fprintf(stderr, "%s:%d:\tsymbol %s %s value contains %s\n",
1102				prop->filename, prop->lineno,
1103				sym->name ? sym->name : "<choice>",
1104				prop_get_type_name(prop->type),
1105				next_sym->name ? next_sym->name : "<choice>");
1106		} else {
1107			fprintf(stderr, "%s:%d:\tsymbol %s %s is visible depending on %s\n",
1108				prop->filename, prop->lineno,
1109				sym->name ? sym->name : "<choice>",
1110				prop_get_type_name(prop->type),
1111				next_sym->name ? next_sym->name : "<choice>");
1112		}
1113	}
1114
1115	fprintf(stderr,
1116		"For a resolution refer to Documentation/kbuild/kconfig-language.rst\n"
1117		"subsection \"Kconfig recursive dependency limitations\"\n"
1118		"\n");
1119
1120	if (check_top == &cv_stack)
1121		dep_stack_remove();
1122}
1123
1124static struct symbol *sym_check_expr_deps(struct expr *e)
1125{
1126	struct symbol *sym;
1127
1128	if (!e)
1129		return NULL;
1130	switch (e->type) {
1131	case E_OR:
1132	case E_AND:
1133		sym = sym_check_expr_deps(e->left.expr);
1134		if (sym)
1135			return sym;
1136		return sym_check_expr_deps(e->right.expr);
1137	case E_NOT:
1138		return sym_check_expr_deps(e->left.expr);
1139	case E_EQUAL:
1140	case E_GEQ:
1141	case E_GTH:
1142	case E_LEQ:
1143	case E_LTH:
1144	case E_UNEQUAL:
1145		sym = sym_check_deps(e->left.sym);
1146		if (sym)
1147			return sym;
1148		return sym_check_deps(e->right.sym);
1149	case E_SYMBOL:
1150		return sym_check_deps(e->left.sym);
1151	default:
1152		break;
1153	}
1154	fprintf(stderr, "Oops! How to check %d?\n", e->type);
1155	return NULL;
1156}
1157
1158/* return NULL when dependencies are OK */
1159static struct symbol *sym_check_sym_deps(struct symbol *sym)
1160{
1161	struct symbol *sym2;
1162	struct property *prop;
1163	struct dep_stack stack;
1164
1165	dep_stack_insert(&stack, sym);
1166
1167	stack.expr = &sym->dir_dep.expr;
1168	sym2 = sym_check_expr_deps(sym->dir_dep.expr);
1169	if (sym2)
1170		goto out;
1171
1172	stack.expr = &sym->rev_dep.expr;
1173	sym2 = sym_check_expr_deps(sym->rev_dep.expr);
1174	if (sym2)
1175		goto out;
1176
1177	stack.expr = &sym->implied.expr;
1178	sym2 = sym_check_expr_deps(sym->implied.expr);
1179	if (sym2)
1180		goto out;
1181
1182	stack.expr = NULL;
1183
1184	for (prop = sym->prop; prop; prop = prop->next) {
1185		if (prop->type == P_CHOICE || prop->type == P_SELECT ||
1186		    prop->type == P_IMPLY)
1187			continue;
1188		stack.prop = prop;
1189		sym2 = sym_check_expr_deps(prop->visible.expr);
1190		if (sym2)
1191			break;
1192		if (prop->type != P_DEFAULT || sym_is_choice(sym))
1193			continue;
1194		stack.expr = &prop->expr;
1195		sym2 = sym_check_expr_deps(prop->expr);
1196		if (sym2)
1197			break;
1198		stack.expr = NULL;
1199	}
1200
1201out:
1202	dep_stack_remove();
1203
1204	return sym2;
1205}
1206
1207static struct symbol *sym_check_choice_deps(struct symbol *choice)
1208{
1209	struct menu *choice_menu, *menu;
1210	struct symbol *sym2;
1211	struct dep_stack stack;
1212
1213	dep_stack_insert(&stack, choice);
1214
1215	choice_menu = list_first_entry(&choice->menus, struct menu, link);
1216
1217	menu_for_each_sub_entry(menu, choice_menu) {
1218		if (menu->sym)
1219			menu->sym->flags |= SYMBOL_CHECK | SYMBOL_CHECKED;
1220	}
1221
1222	choice->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1223	sym2 = sym_check_sym_deps(choice);
1224	choice->flags &= ~SYMBOL_CHECK;
1225	if (sym2)
1226		goto out;
1227
1228	menu_for_each_sub_entry(menu, choice_menu) {
1229		if (!menu->sym)
1230			continue;
1231		sym2 = sym_check_sym_deps(menu->sym);
1232		if (sym2)
1233			break;
1234	}
1235out:
1236	menu_for_each_sub_entry(menu, choice_menu)
1237		if (menu->sym)
1238			menu->sym->flags &= ~SYMBOL_CHECK;
1239
1240	if (sym2 && sym_is_choice_value(sym2) &&
1241	    prop_get_symbol(sym_get_choice_prop(sym2)) == choice)
1242		sym2 = choice;
1243
1244	dep_stack_remove();
1245
1246	return sym2;
1247}
1248
1249struct symbol *sym_check_deps(struct symbol *sym)
1250{
1251	struct symbol *sym2;
1252	struct property *prop;
1253
1254	if (sym->flags & SYMBOL_CHECK) {
1255		sym_check_print_recursive(sym);
1256		return sym;
1257	}
1258	if (sym->flags & SYMBOL_CHECKED)
1259		return NULL;
1260
1261	if (sym_is_choice_value(sym)) {
1262		struct dep_stack stack;
1263
1264		/* for choice groups start the check with main choice symbol */
1265		dep_stack_insert(&stack, sym);
1266		prop = sym_get_choice_prop(sym);
1267		sym2 = sym_check_deps(prop_get_symbol(prop));
1268		dep_stack_remove();
1269	} else if (sym_is_choice(sym)) {
1270		sym2 = sym_check_choice_deps(sym);
1271	} else {
1272		sym->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1273		sym2 = sym_check_sym_deps(sym);
1274		sym->flags &= ~SYMBOL_CHECK;
1275	}
1276
1277	return sym2;
1278}
1279
1280struct symbol *prop_get_symbol(struct property *prop)
1281{
1282	if (prop->expr && (prop->expr->type == E_SYMBOL ||
1283			   prop->expr->type == E_LIST))
1284		return prop->expr->left.sym;
1285	return NULL;
1286}
1287
1288const char *prop_get_type_name(enum prop_type type)
1289{
1290	switch (type) {
1291	case P_PROMPT:
1292		return "prompt";
1293	case P_COMMENT:
1294		return "comment";
1295	case P_MENU:
1296		return "menu";
1297	case P_DEFAULT:
1298		return "default";
1299	case P_CHOICE:
1300		return "choice";
1301	case P_SELECT:
1302		return "select";
1303	case P_IMPLY:
1304		return "imply";
1305	case P_RANGE:
1306		return "range";
1307	case P_SYMBOL:
1308		return "symbol";
1309	case P_UNKNOWN:
1310		break;
1311	}
1312	return "unknown";
1313}
1314