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