xref: /linux/scripts/kconfig/symbol.c (revision a530a36bb548bbd441402b736f17339183ff53fd)
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 <hash.h>
13 #include <xalloc.h>
14 #include "internal.h"
15 #include "lkc.h"
16 
17 struct symbol symbol_yes = {
18 	.name = "y",
19 	.type = S_TRISTATE,
20 	.curr = { "y", yes },
21 	.menus = LIST_HEAD_INIT(symbol_yes.menus),
22 	.flags = SYMBOL_CONST|SYMBOL_VALID,
23 };
24 
25 struct symbol symbol_mod = {
26 	.name = "m",
27 	.type = S_TRISTATE,
28 	.curr = { "m", mod },
29 	.menus = LIST_HEAD_INIT(symbol_mod.menus),
30 	.flags = SYMBOL_CONST|SYMBOL_VALID,
31 };
32 
33 struct symbol symbol_no = {
34 	.name = "n",
35 	.type = S_TRISTATE,
36 	.curr = { "n", no },
37 	.menus = LIST_HEAD_INIT(symbol_no.menus),
38 	.flags = SYMBOL_CONST|SYMBOL_VALID,
39 };
40 
41 struct symbol *modules_sym;
42 static tristate modules_val;
43 static int sym_warnings;
44 
sym_get_type(const struct symbol * sym)45 enum symbol_type sym_get_type(const struct symbol *sym)
46 {
47 	enum symbol_type type = sym->type;
48 
49 	if (type == S_TRISTATE && modules_val == no)
50 		type = S_BOOLEAN;
51 	return type;
52 }
53 
sym_type_name(enum symbol_type type)54 const char *sym_type_name(enum symbol_type type)
55 {
56 	switch (type) {
57 	case S_BOOLEAN:
58 		return "bool";
59 	case S_TRISTATE:
60 		return "tristate";
61 	case S_INT:
62 		return "integer";
63 	case S_HEX:
64 		return "hex";
65 	case S_STRING:
66 		return "string";
67 	case S_UNKNOWN:
68 		return "unknown";
69 	}
70 	return "???";
71 }
72 
73 /**
74  * sym_get_prompt_menu - get the menu entry with a prompt
75  *
76  * @sym: a symbol pointer
77  *
78  * Return: the menu entry with a prompt.
79  */
sym_get_prompt_menu(const struct symbol * sym)80 struct menu *sym_get_prompt_menu(const struct symbol *sym)
81 {
82 	struct menu *m;
83 
84 	list_for_each_entry(m, &sym->menus, link)
85 		if (m->prompt)
86 			return m;
87 
88 	return NULL;
89 }
90 
91 /**
92  * sym_get_choice_menu - get the parent choice menu if present
93  *
94  * @sym: a symbol pointer
95  *
96  * Return: a choice menu if this function is called against a choice member.
97  */
sym_get_choice_menu(const struct symbol * sym)98 struct menu *sym_get_choice_menu(const struct symbol *sym)
99 {
100 	struct menu *menu = NULL;
101 
102 	/*
103 	 * Choice members must have a prompt. Find a menu entry with a prompt,
104 	 * and assume it resides inside a choice block.
105 	 */
106 	menu = sym_get_prompt_menu(sym);
107 	if (!menu)
108 		return NULL;
109 
110 	do {
111 		menu = menu->parent;
112 	} while (menu && !menu->sym);
113 
114 	if (menu && menu->sym && sym_is_choice(menu->sym))
115 		return menu;
116 
117 	return NULL;
118 }
119 
sym_get_default_prop(struct symbol * sym)120 static struct property *sym_get_default_prop(struct symbol *sym)
121 {
122 	struct property *prop;
123 
124 	for_all_defaults(sym, prop) {
125 		prop->visible.tri = expr_calc_value(prop->visible.expr);
126 		if (prop->visible.tri != no)
127 			return prop;
128 	}
129 	return NULL;
130 }
131 
sym_get_range_prop(struct symbol * sym)132 struct property *sym_get_range_prop(struct symbol *sym)
133 {
134 	struct property *prop;
135 
136 	for_all_properties(sym, prop, P_RANGE) {
137 		prop->visible.tri = expr_calc_value(prop->visible.expr);
138 		if (prop->visible.tri != no)
139 			return prop;
140 	}
141 	return NULL;
142 }
143 
sym_get_range_val(struct symbol * sym,int base)144 static long long sym_get_range_val(struct symbol *sym, int base)
145 {
146 	sym_calc_value(sym);
147 	switch (sym->type) {
148 	case S_INT:
149 		base = 10;
150 		break;
151 	case S_HEX:
152 		base = 16;
153 		break;
154 	default:
155 		break;
156 	}
157 	return strtoll(sym->curr.val, NULL, base);
158 }
159 
sym_validate_range(struct symbol * sym)160 static void sym_validate_range(struct symbol *sym)
161 {
162 	struct property *prop;
163 	struct symbol *range_sym;
164 	int base;
165 	long long val, val2;
166 
167 	switch (sym->type) {
168 	case S_INT:
169 		base = 10;
170 		break;
171 	case S_HEX:
172 		base = 16;
173 		break;
174 	default:
175 		return;
176 	}
177 	prop = sym_get_range_prop(sym);
178 	if (!prop)
179 		return;
180 	val = strtoll(sym->curr.val, NULL, base);
181 	range_sym = prop->expr->left.sym;
182 	val2 = sym_get_range_val(range_sym, base);
183 	if (val >= val2) {
184 		range_sym = prop->expr->right.sym;
185 		val2 = sym_get_range_val(range_sym, base);
186 		if (val <= val2)
187 			return;
188 	}
189 	sym->curr.val = range_sym->curr.val;
190 }
191 
sym_set_changed(struct symbol * sym)192 static void sym_set_changed(struct symbol *sym)
193 {
194 	struct menu *menu;
195 
196 	list_for_each_entry(menu, &sym->menus, link)
197 		menu->flags |= MENU_CHANGED;
198 
199 	menu = sym_get_choice_menu(sym);
200 	if (menu)
201 		menu->flags |= MENU_CHANGED;
202 }
203 
sym_set_all_changed(void)204 static void sym_set_all_changed(void)
205 {
206 	struct symbol *sym;
207 
208 	for_all_symbols(sym)
209 		sym_set_changed(sym);
210 }
211 
sym_calc_visibility(struct symbol * sym)212 static void sym_calc_visibility(struct symbol *sym)
213 {
214 	struct property *prop;
215 	tristate tri;
216 
217 	/* any prompt visible? */
218 	tri = no;
219 	for_all_prompts(sym, prop) {
220 		prop->visible.tri = expr_calc_value(prop->visible.expr);
221 		tri = EXPR_OR(tri, prop->visible.tri);
222 	}
223 	if (tri == mod && (sym->type != S_TRISTATE || modules_val == no))
224 		tri = yes;
225 	if (sym->visible != tri) {
226 		sym->visible = tri;
227 		sym_set_changed(sym);
228 	}
229 	if (sym_is_choice_value(sym))
230 		return;
231 	/* defaulting to "yes" if no explicit "depends on" are given */
232 	tri = yes;
233 	if (sym->dir_dep.expr)
234 		tri = expr_calc_value(sym->dir_dep.expr);
235 	if (tri == mod && sym_get_type(sym) == S_BOOLEAN)
236 		tri = yes;
237 	if (sym->dir_dep.tri != tri) {
238 		sym->dir_dep.tri = tri;
239 		sym_set_changed(sym);
240 	}
241 	tri = no;
242 	if (sym->rev_dep.expr)
243 		tri = expr_calc_value(sym->rev_dep.expr);
244 	if (tri == mod && sym_get_type(sym) == S_BOOLEAN)
245 		tri = yes;
246 	if (sym->rev_dep.tri != tri) {
247 		sym->rev_dep.tri = tri;
248 		sym_set_changed(sym);
249 	}
250 	tri = no;
251 	if (sym->implied.expr)
252 		tri = expr_calc_value(sym->implied.expr);
253 	if (tri == mod && sym_get_type(sym) == S_BOOLEAN)
254 		tri = yes;
255 	if (sym->implied.tri != tri) {
256 		sym->implied.tri = tri;
257 		sym_set_changed(sym);
258 	}
259 }
260 
261 /*
262  * Find the default symbol for a choice.
263  * First try the default values for the choice symbol
264  * Next locate the first visible choice value
265  * Return NULL if none was found
266  */
sym_choice_default(struct menu * choice)267 struct symbol *sym_choice_default(struct menu *choice)
268 {
269 	struct menu *menu;
270 	struct symbol *def_sym;
271 	struct property *prop;
272 
273 	/* any of the defaults visible? */
274 	for_all_defaults(choice->sym, prop) {
275 		prop->visible.tri = expr_calc_value(prop->visible.expr);
276 		if (prop->visible.tri == no)
277 			continue;
278 		def_sym = prop_get_symbol(prop);
279 		if (def_sym->visible != no)
280 			return def_sym;
281 	}
282 
283 	/* just get the first visible value */
284 	menu_for_each_sub_entry(menu, choice)
285 		if (menu->sym && menu->sym->visible != no)
286 			return menu->sym;
287 
288 	/* failed to locate any defaults */
289 	return NULL;
290 }
291 
292 /*
293  * sym_calc_choice - calculate symbol values in a choice
294  *
295  * @choice: a menu of the choice
296  *
297  * Return: a chosen symbol
298  */
sym_calc_choice(struct menu * choice)299 struct symbol *sym_calc_choice(struct menu *choice)
300 {
301 	struct symbol *res = NULL;
302 	struct symbol *sym;
303 	struct menu *menu;
304 
305 	/* Traverse the list of choice members in the priority order. */
306 	list_for_each_entry(sym, &choice->choice_members, choice_link) {
307 		sym_calc_visibility(sym);
308 		if (sym->visible == no)
309 			continue;
310 
311 		/* The first visible symble with the user value 'y'. */
312 		if (sym_has_value(sym) && sym->def[S_DEF_USER].tri == yes) {
313 			res = sym;
314 			break;
315 		}
316 	}
317 
318 	/*
319 	 * If 'y' is not found in the user input, use the default, unless it is
320 	 * explicitly set to 'n'.
321 	 */
322 	if (!res) {
323 		res = sym_choice_default(choice);
324 		if (res && sym_has_value(res) && res->def[S_DEF_USER].tri == no)
325 			res = NULL;
326 	}
327 
328 	/* Still not found. Pick up the first visible, user-unspecified symbol. */
329 	if (!res) {
330 		menu_for_each_sub_entry(menu, choice) {
331 			sym = menu->sym;
332 
333 			if (!sym || sym->visible == no || sym_has_value(sym))
334 				continue;
335 
336 			res = sym;
337 			break;
338 		}
339 	}
340 
341 	/*
342 	 * Still not found. Traverse the linked list in the _reverse_ order to
343 	 * pick up the least prioritized 'n'.
344 	 */
345 	if (!res) {
346 		list_for_each_entry_reverse(sym, &choice->choice_members,
347 					    choice_link) {
348 			if (sym->visible == no)
349 				continue;
350 
351 			res = sym;
352 			break;
353 		}
354 	}
355 
356 	menu_for_each_sub_entry(menu, choice) {
357 		tristate val;
358 
359 		sym = menu->sym;
360 
361 		if (!sym || sym->visible == no)
362 			continue;
363 
364 		val = sym == res ? yes : no;
365 
366 		if (sym->curr.tri != val)
367 			sym_set_changed(sym);
368 
369 		sym->curr.tri = val;
370 		sym->flags |= SYMBOL_VALID | SYMBOL_WRITE;
371 	}
372 
373 	return res;
374 }
375 
sym_warn_unmet_dep(const struct symbol * sym)376 static void sym_warn_unmet_dep(const struct symbol *sym)
377 {
378 	struct gstr gs = str_new();
379 
380 	str_printf(&gs,
381 		   "\nWARNING: unmet direct dependencies detected for %s\n",
382 		   sym->name);
383 	str_printf(&gs,
384 		   "  Depends on [%c]: ",
385 		   sym->dir_dep.tri == mod ? 'm' : 'n');
386 	expr_gstr_print(sym->dir_dep.expr, &gs);
387 	str_printf(&gs, "\n");
388 
389 	expr_gstr_print_revdep(sym->rev_dep.expr, &gs, yes,
390 			       "  Selected by [y]:\n");
391 	expr_gstr_print_revdep(sym->rev_dep.expr, &gs, mod,
392 			       "  Selected by [m]:\n");
393 
394 	fputs(str_get(&gs), stderr);
395 	str_free(&gs);
396 	sym_warnings++;
397 }
398 
sym_dep_errors(void)399 bool sym_dep_errors(void)
400 {
401 	if (sym_warnings)
402 		return getenv("KCONFIG_WERROR");
403 	return false;
404 }
405 
sym_calc_value(struct symbol * sym)406 void sym_calc_value(struct symbol *sym)
407 {
408 	struct symbol_value newval, oldval;
409 	struct property *prop;
410 	struct menu *choice_menu;
411 
412 	if (!sym)
413 		return;
414 
415 	if (sym->flags & SYMBOL_VALID)
416 		return;
417 
418 	sym->flags |= SYMBOL_VALID;
419 
420 	oldval = sym->curr;
421 
422 	newval.tri = no;
423 
424 	switch (sym->type) {
425 	case S_INT:
426 		newval.val = "0";
427 		break;
428 	case S_HEX:
429 		newval.val = "0x0";
430 		break;
431 	case S_STRING:
432 		newval.val = "";
433 		break;
434 	case S_BOOLEAN:
435 	case S_TRISTATE:
436 		newval.val = "n";
437 		break;
438 	default:
439 		sym->curr.val = sym->name;
440 		sym->curr.tri = no;
441 		return;
442 	}
443 	sym->flags &= ~SYMBOL_WRITE;
444 
445 	sym_calc_visibility(sym);
446 
447 	if (sym->visible != no)
448 		sym->flags |= SYMBOL_WRITE;
449 
450 	/* set default if recursively called */
451 	sym->curr = newval;
452 
453 	switch (sym_get_type(sym)) {
454 	case S_BOOLEAN:
455 	case S_TRISTATE:
456 		choice_menu = sym_get_choice_menu(sym);
457 
458 		if (choice_menu) {
459 			sym_calc_choice(choice_menu);
460 			newval.tri = sym->curr.tri;
461 		} else {
462 			if (sym->visible != no) {
463 				/* if the symbol is visible use the user value
464 				 * if available, otherwise try the default value
465 				 */
466 				if (sym_has_value(sym)) {
467 					newval.tri = EXPR_AND(sym->def[S_DEF_USER].tri,
468 							      sym->visible);
469 					goto calc_newval;
470 				}
471 			}
472 			if (sym->rev_dep.tri != no)
473 				sym->flags |= SYMBOL_WRITE;
474 			if (!sym_is_choice(sym)) {
475 				prop = sym_get_default_prop(sym);
476 				if (prop) {
477 					newval.tri = EXPR_AND(expr_calc_value(prop->expr),
478 							      prop->visible.tri);
479 					if (newval.tri != no)
480 						sym->flags |= SYMBOL_WRITE;
481 				}
482 				if (sym->implied.tri != no) {
483 					sym->flags |= SYMBOL_WRITE;
484 					newval.tri = EXPR_OR(newval.tri, sym->implied.tri);
485 					newval.tri = EXPR_AND(newval.tri,
486 							      sym->dir_dep.tri);
487 				}
488 			}
489 		calc_newval:
490 			if (sym->dir_dep.tri < sym->rev_dep.tri)
491 				sym_warn_unmet_dep(sym);
492 			newval.tri = EXPR_OR(newval.tri, sym->rev_dep.tri);
493 		}
494 		if (newval.tri == mod && sym_get_type(sym) == S_BOOLEAN)
495 			newval.tri = yes;
496 		break;
497 	case S_STRING:
498 	case S_HEX:
499 	case S_INT:
500 		if (sym->visible != no && sym_has_value(sym)) {
501 			newval.val = sym->def[S_DEF_USER].val;
502 			break;
503 		}
504 		prop = sym_get_default_prop(sym);
505 		if (prop) {
506 			struct symbol *ds = prop_get_symbol(prop);
507 			if (ds) {
508 				sym->flags |= SYMBOL_WRITE;
509 				sym_calc_value(ds);
510 				newval.val = ds->curr.val;
511 			}
512 		}
513 		break;
514 	default:
515 		;
516 	}
517 
518 	sym->curr = newval;
519 	sym_validate_range(sym);
520 
521 	if (memcmp(&oldval, &sym->curr, sizeof(oldval))) {
522 		sym_set_changed(sym);
523 		if (modules_sym == sym) {
524 			sym_set_all_changed();
525 			modules_val = modules_sym->curr.tri;
526 		}
527 	}
528 
529 	if (sym_is_choice(sym))
530 		sym->flags &= ~SYMBOL_WRITE;
531 }
532 
sym_clear_all_valid(void)533 void sym_clear_all_valid(void)
534 {
535 	struct symbol *sym;
536 
537 	for_all_symbols(sym)
538 		sym->flags &= ~SYMBOL_VALID;
539 	expr_invalidate_all();
540 	conf_set_changed(true);
541 	sym_calc_value(modules_sym);
542 }
543 
sym_tristate_within_range(const struct symbol * sym,tristate val)544 bool sym_tristate_within_range(const struct symbol *sym, tristate val)
545 {
546 	int type = sym_get_type(sym);
547 
548 	if (sym->visible == no)
549 		return false;
550 
551 	if (type != S_BOOLEAN && type != S_TRISTATE)
552 		return false;
553 
554 	if (type == S_BOOLEAN && val == mod)
555 		return false;
556 	if (sym->visible <= sym->rev_dep.tri)
557 		return false;
558 	return val >= sym->rev_dep.tri && val <= sym->visible;
559 }
560 
sym_set_tristate_value(struct symbol * sym,tristate val)561 bool sym_set_tristate_value(struct symbol *sym, tristate val)
562 {
563 	tristate oldval = sym_get_tristate_value(sym);
564 
565 	if (!sym_tristate_within_range(sym, val))
566 		return false;
567 
568 	if (!(sym->flags & SYMBOL_DEF_USER) || sym->def[S_DEF_USER].tri != val) {
569 		sym->def[S_DEF_USER].tri = val;
570 		sym->flags |= SYMBOL_DEF_USER;
571 		sym_set_changed(sym);
572 	}
573 
574 	if (oldval != val)
575 		sym_clear_all_valid();
576 
577 	return true;
578 }
579 
580 /**
581  * choice_set_value - set the user input to a choice
582  *
583  * @choice: menu entry for the choice
584  * @sym: selected symbol
585  */
choice_set_value(struct menu * choice,struct symbol * sym)586 void choice_set_value(struct menu *choice, struct symbol *sym)
587 {
588 	struct menu *menu;
589 	bool changed = false;
590 
591 	menu_for_each_sub_entry(menu, choice) {
592 		tristate val;
593 
594 		if (!menu->sym)
595 			continue;
596 
597 		if (menu->sym->visible == no)
598 			continue;
599 
600 		val = menu->sym == sym ? yes : no;
601 
602 		if (menu->sym->curr.tri != val)
603 			changed = true;
604 
605 		menu->sym->def[S_DEF_USER].tri = val;
606 		menu->sym->flags |= SYMBOL_DEF_USER;
607 
608 		/*
609 		 * Now, the user has explicitly enabled or disabled this symbol,
610 		 * it should be given the highest priority. We are possibly
611 		 * setting multiple symbols to 'n', where the first symbol is
612 		 * given the least prioritized 'n'. This works well when the
613 		 * choice block ends up with selecting 'n' symbol.
614 		 * (see sym_calc_choice())
615 		 */
616 		list_move(&menu->sym->choice_link, &choice->choice_members);
617 	}
618 
619 	if (changed)
620 		sym_clear_all_valid();
621 }
622 
sym_toggle_tristate_value(struct symbol * sym)623 tristate sym_toggle_tristate_value(struct symbol *sym)
624 {
625 	struct menu *choice;
626 	tristate oldval, newval;
627 
628 	choice = sym_get_choice_menu(sym);
629 	if (choice) {
630 		choice_set_value(choice, sym);
631 		return yes;
632 	}
633 
634 	oldval = newval = sym_get_tristate_value(sym);
635 	do {
636 		switch (newval) {
637 		case no:
638 			newval = mod;
639 			break;
640 		case mod:
641 			newval = yes;
642 			break;
643 		case yes:
644 			newval = no;
645 			break;
646 		}
647 		if (sym_set_tristate_value(sym, newval))
648 			break;
649 	} while (oldval != newval);
650 	return newval;
651 }
652 
sym_string_valid(struct symbol * sym,const char * str)653 bool sym_string_valid(struct symbol *sym, const char *str)
654 {
655 	signed char ch;
656 
657 	switch (sym->type) {
658 	case S_STRING:
659 		return true;
660 	case S_INT:
661 		ch = *str++;
662 		if (ch == '-')
663 			ch = *str++;
664 		if (!isdigit(ch))
665 			return false;
666 		if (ch == '0' && *str != 0)
667 			return false;
668 		while ((ch = *str++)) {
669 			if (!isdigit(ch))
670 				return false;
671 		}
672 		return true;
673 	case S_HEX:
674 		if (str[0] == '0' && (str[1] == 'x' || str[1] == 'X'))
675 			str += 2;
676 		ch = *str++;
677 		do {
678 			if (!isxdigit(ch))
679 				return false;
680 		} while ((ch = *str++));
681 		return true;
682 	case S_BOOLEAN:
683 	case S_TRISTATE:
684 		switch (str[0]) {
685 		case 'y': case 'Y':
686 		case 'm': case 'M':
687 		case 'n': case 'N':
688 			return true;
689 		}
690 		return false;
691 	default:
692 		return false;
693 	}
694 }
695 
sym_string_within_range(struct symbol * sym,const char * str)696 bool sym_string_within_range(struct symbol *sym, const char *str)
697 {
698 	struct property *prop;
699 	long long val;
700 
701 	switch (sym->type) {
702 	case S_STRING:
703 		return sym_string_valid(sym, str);
704 	case S_INT:
705 		if (!sym_string_valid(sym, str))
706 			return false;
707 		prop = sym_get_range_prop(sym);
708 		if (!prop)
709 			return true;
710 		val = strtoll(str, NULL, 10);
711 		return val >= sym_get_range_val(prop->expr->left.sym, 10) &&
712 		       val <= sym_get_range_val(prop->expr->right.sym, 10);
713 	case S_HEX:
714 		if (!sym_string_valid(sym, str))
715 			return false;
716 		prop = sym_get_range_prop(sym);
717 		if (!prop)
718 			return true;
719 		val = strtoll(str, NULL, 16);
720 		return val >= sym_get_range_val(prop->expr->left.sym, 16) &&
721 		       val <= sym_get_range_val(prop->expr->right.sym, 16);
722 	case S_BOOLEAN:
723 	case S_TRISTATE:
724 		switch (str[0]) {
725 		case 'y': case 'Y':
726 			return sym_tristate_within_range(sym, yes);
727 		case 'm': case 'M':
728 			return sym_tristate_within_range(sym, mod);
729 		case 'n': case 'N':
730 			return sym_tristate_within_range(sym, no);
731 		}
732 		return false;
733 	default:
734 		return false;
735 	}
736 }
737 
sym_set_string_value(struct symbol * sym,const char * newval)738 bool sym_set_string_value(struct symbol *sym, const char *newval)
739 {
740 	const char *oldval;
741 	char *val;
742 	int size;
743 
744 	switch (sym->type) {
745 	case S_BOOLEAN:
746 	case S_TRISTATE:
747 		switch (newval[0]) {
748 		case 'y': case 'Y':
749 			return sym_set_tristate_value(sym, yes);
750 		case 'm': case 'M':
751 			return sym_set_tristate_value(sym, mod);
752 		case 'n': case 'N':
753 			return sym_set_tristate_value(sym, no);
754 		}
755 		return false;
756 	default:
757 		;
758 	}
759 
760 	if (!sym_string_within_range(sym, newval))
761 		return false;
762 
763 	if (!(sym->flags & SYMBOL_DEF_USER)) {
764 		sym->flags |= SYMBOL_DEF_USER;
765 		sym_set_changed(sym);
766 	}
767 
768 	oldval = sym->def[S_DEF_USER].val;
769 	size = strlen(newval) + 1;
770 	if (sym->type == S_HEX && (newval[0] != '0' || (newval[1] != 'x' && newval[1] != 'X'))) {
771 		size += 2;
772 		sym->def[S_DEF_USER].val = val = xmalloc(size);
773 		*val++ = '0';
774 		*val++ = 'x';
775 	} else if (!oldval || strcmp(oldval, newval))
776 		sym->def[S_DEF_USER].val = val = xmalloc(size);
777 	else
778 		return true;
779 
780 	strcpy(val, newval);
781 	free((void *)oldval);
782 	sym_clear_all_valid();
783 
784 	return true;
785 }
786 
787 /*
788  * Find the default value associated to a symbol.
789  * For tristate symbol handle the modules=n case
790  * in which case "m" becomes "y".
791  * If the symbol does not have any default then fallback
792  * to the fixed default values.
793  */
sym_get_string_default(struct symbol * sym)794 const char *sym_get_string_default(struct symbol *sym)
795 {
796 	struct property *prop;
797 	struct symbol *ds;
798 	const char *str = "";
799 	tristate val;
800 
801 	sym_calc_visibility(sym);
802 	sym_calc_value(modules_sym);
803 	val = symbol_no.curr.tri;
804 
805 	/* If symbol has a default value look it up */
806 	prop = sym_get_default_prop(sym);
807 	if (prop != NULL) {
808 		switch (sym->type) {
809 		case S_BOOLEAN:
810 		case S_TRISTATE:
811 			/* The visibility may limit the value from yes => mod */
812 			val = EXPR_AND(expr_calc_value(prop->expr), prop->visible.tri);
813 			break;
814 		default:
815 			/*
816 			 * The following fails to handle the situation
817 			 * where a default value is further limited by
818 			 * the valid range.
819 			 */
820 			ds = prop_get_symbol(prop);
821 			if (ds != NULL) {
822 				sym_calc_value(ds);
823 				str = (const char *)ds->curr.val;
824 			}
825 		}
826 	}
827 
828 	/* Handle select statements */
829 	val = EXPR_OR(val, sym->rev_dep.tri);
830 
831 	/* transpose mod to yes if modules are not enabled */
832 	if (val == mod)
833 		if (!sym_is_choice_value(sym) && modules_sym->curr.tri == no)
834 			val = yes;
835 
836 	/* transpose mod to yes if type is bool */
837 	if (sym->type == S_BOOLEAN && val == mod)
838 		val = yes;
839 
840 	/* adjust the default value if this symbol is implied by another */
841 	if (val < sym->implied.tri)
842 		val = sym->implied.tri;
843 
844 	switch (sym->type) {
845 	case S_BOOLEAN:
846 	case S_TRISTATE:
847 		switch (val) {
848 		case no: return "n";
849 		case mod: return "m";
850 		case yes: return "y";
851 		}
852 	case S_INT:
853 		if (!str[0])
854 			str = "0";
855 		break;
856 	case S_HEX:
857 		if (!str[0])
858 			str = "0x0";
859 		break;
860 	default:
861 		break;
862 	}
863 	return str;
864 }
865 
sym_get_string_value(struct symbol * sym)866 const char *sym_get_string_value(struct symbol *sym)
867 {
868 	tristate val;
869 
870 	switch (sym->type) {
871 	case S_BOOLEAN:
872 	case S_TRISTATE:
873 		val = sym_get_tristate_value(sym);
874 		switch (val) {
875 		case no:
876 			return "n";
877 		case mod:
878 			return "m";
879 		case yes:
880 			return "y";
881 		}
882 		break;
883 	default:
884 		;
885 	}
886 	return sym->curr.val;
887 }
888 
sym_is_changeable(const struct symbol * sym)889 bool sym_is_changeable(const struct symbol *sym)
890 {
891 	return !sym_is_choice(sym) && sym->visible > sym->rev_dep.tri;
892 }
893 
sym_is_choice_value(const struct symbol * sym)894 bool sym_is_choice_value(const struct symbol *sym)
895 {
896 	return !list_empty(&sym->choice_link);
897 }
898 
899 HASHTABLE_DEFINE(sym_hashtable, SYMBOL_HASHSIZE);
900 
sym_lookup(const char * name,int flags)901 struct symbol *sym_lookup(const char *name, int flags)
902 {
903 	struct symbol *symbol;
904 	char *new_name;
905 	int hash;
906 
907 	if (name) {
908 		if (name[0] && !name[1]) {
909 			switch (name[0]) {
910 			case 'y': return &symbol_yes;
911 			case 'm': return &symbol_mod;
912 			case 'n': return &symbol_no;
913 			}
914 		}
915 		hash = hash_str(name);
916 
917 		hash_for_each_possible(sym_hashtable, symbol, node, hash) {
918 			if (symbol->name &&
919 			    !strcmp(symbol->name, name) &&
920 			    (flags ? symbol->flags & flags
921 				   : !(symbol->flags & SYMBOL_CONST)))
922 				return symbol;
923 		}
924 		new_name = xstrdup(name);
925 	} else {
926 		new_name = NULL;
927 		hash = 0;
928 	}
929 
930 	symbol = xmalloc(sizeof(*symbol));
931 	memset(symbol, 0, sizeof(*symbol));
932 	symbol->name = new_name;
933 	symbol->type = S_UNKNOWN;
934 	symbol->flags = flags;
935 	INIT_LIST_HEAD(&symbol->menus);
936 	INIT_LIST_HEAD(&symbol->choice_link);
937 
938 	hash_add(sym_hashtable, &symbol->node, hash);
939 
940 	return symbol;
941 }
942 
sym_find(const char * name)943 struct symbol *sym_find(const char *name)
944 {
945 	struct symbol *symbol = NULL;
946 	int hash = 0;
947 
948 	if (!name)
949 		return NULL;
950 
951 	if (name[0] && !name[1]) {
952 		switch (name[0]) {
953 		case 'y': return &symbol_yes;
954 		case 'm': return &symbol_mod;
955 		case 'n': return &symbol_no;
956 		}
957 	}
958 	hash = hash_str(name);
959 
960 	hash_for_each_possible(sym_hashtable, symbol, node, hash) {
961 		if (symbol->name &&
962 		    !strcmp(symbol->name, name) &&
963 		    !(symbol->flags & SYMBOL_CONST))
964 				break;
965 	}
966 
967 	return symbol;
968 }
969 
970 struct sym_match {
971 	struct symbol	*sym;
972 	off_t		so, eo;
973 };
974 
975 /* Compare matched symbols as thus:
976  * - first, symbols that match exactly
977  * - then, alphabetical sort
978  */
sym_rel_comp(const void * sym1,const void * sym2)979 static int sym_rel_comp(const void *sym1, const void *sym2)
980 {
981 	const struct sym_match *s1 = sym1;
982 	const struct sym_match *s2 = sym2;
983 	int exact1, exact2;
984 
985 	/* Exact match:
986 	 * - if matched length on symbol s1 is the length of that symbol,
987 	 *   then this symbol should come first;
988 	 * - if matched length on symbol s2 is the length of that symbol,
989 	 *   then this symbol should come first.
990 	 * Note: since the search can be a regexp, both symbols may match
991 	 * exactly; if this is the case, we can't decide which comes first,
992 	 * and we fallback to sorting alphabetically.
993 	 */
994 	exact1 = (s1->eo - s1->so) == strlen(s1->sym->name);
995 	exact2 = (s2->eo - s2->so) == strlen(s2->sym->name);
996 	if (exact1 && !exact2)
997 		return -1;
998 	if (!exact1 && exact2)
999 		return 1;
1000 
1001 	/* As a fallback, sort symbols alphabetically */
1002 	return strcmp(s1->sym->name, s2->sym->name);
1003 }
1004 
sym_re_search(const char * pattern)1005 struct symbol **sym_re_search(const char *pattern)
1006 {
1007 	struct symbol *sym, **sym_arr = NULL;
1008 	struct sym_match *sym_match_arr = NULL;
1009 	int i, cnt, size;
1010 	regex_t re;
1011 	regmatch_t match[1];
1012 
1013 	cnt = size = 0;
1014 	/* Skip if empty */
1015 	if (strlen(pattern) == 0)
1016 		return NULL;
1017 	if (regcomp(&re, pattern, REG_EXTENDED|REG_ICASE))
1018 		return NULL;
1019 
1020 	for_all_symbols(sym) {
1021 		if (sym->flags & SYMBOL_CONST || !sym->name)
1022 			continue;
1023 		if (regexec(&re, sym->name, 1, match, 0))
1024 			continue;
1025 		if (cnt >= size) {
1026 			void *tmp;
1027 			size += 16;
1028 			tmp = realloc(sym_match_arr, size * sizeof(struct sym_match));
1029 			if (!tmp)
1030 				goto sym_re_search_free;
1031 			sym_match_arr = tmp;
1032 		}
1033 		sym_calc_value(sym);
1034 		/* As regexec returned 0, we know we have a match, so
1035 		 * we can use match[0].rm_[se]o without further checks
1036 		 */
1037 		sym_match_arr[cnt].so = match[0].rm_so;
1038 		sym_match_arr[cnt].eo = match[0].rm_eo;
1039 		sym_match_arr[cnt++].sym = sym;
1040 	}
1041 	if (sym_match_arr) {
1042 		qsort(sym_match_arr, cnt, sizeof(struct sym_match), sym_rel_comp);
1043 		sym_arr = malloc((cnt+1) * sizeof(struct symbol *));
1044 		if (!sym_arr)
1045 			goto sym_re_search_free;
1046 		for (i = 0; i < cnt; i++)
1047 			sym_arr[i] = sym_match_arr[i].sym;
1048 		sym_arr[cnt] = NULL;
1049 	}
1050 sym_re_search_free:
1051 	/* sym_match_arr can be NULL if no match, but free(NULL) is OK */
1052 	free(sym_match_arr);
1053 	regfree(&re);
1054 
1055 	return sym_arr;
1056 }
1057 
1058 /*
1059  * When we check for recursive dependencies we use a stack to save
1060  * current state so we can print out relevant info to user.
1061  * The entries are located on the call stack so no need to free memory.
1062  * Note insert() remove() must always match to properly clear the stack.
1063  */
1064 static struct dep_stack {
1065 	struct dep_stack *prev, *next;
1066 	struct symbol *sym;
1067 	struct property *prop;
1068 	struct expr **expr;
1069 } *check_top;
1070 
dep_stack_insert(struct dep_stack * stack,struct symbol * sym)1071 static void dep_stack_insert(struct dep_stack *stack, struct symbol *sym)
1072 {
1073 	memset(stack, 0, sizeof(*stack));
1074 	if (check_top)
1075 		check_top->next = stack;
1076 	stack->prev = check_top;
1077 	stack->sym = sym;
1078 	check_top = stack;
1079 }
1080 
dep_stack_remove(void)1081 static void dep_stack_remove(void)
1082 {
1083 	check_top = check_top->prev;
1084 	if (check_top)
1085 		check_top->next = NULL;
1086 }
1087 
1088 /*
1089  * Called when we have detected a recursive dependency.
1090  * check_top point to the top of the stact so we use
1091  * the ->prev pointer to locate the bottom of the stack.
1092  */
sym_check_print_recursive(struct symbol * last_sym)1093 static void sym_check_print_recursive(struct symbol *last_sym)
1094 {
1095 	struct dep_stack *stack;
1096 	struct symbol *sym, *next_sym;
1097 	struct menu *choice;
1098 	struct dep_stack cv_stack;
1099 	enum prop_type type;
1100 
1101 	choice = sym_get_choice_menu(last_sym);
1102 	if (choice) {
1103 		dep_stack_insert(&cv_stack, last_sym);
1104 		last_sym = choice->sym;
1105 	}
1106 
1107 	for (stack = check_top; stack != NULL; stack = stack->prev)
1108 		if (stack->sym == last_sym)
1109 			break;
1110 	if (!stack) {
1111 		fprintf(stderr, "unexpected recursive dependency error\n");
1112 		return;
1113 	}
1114 
1115 	for (; stack; stack = stack->next) {
1116 		sym = stack->sym;
1117 		next_sym = stack->next ? stack->next->sym : last_sym;
1118 		type = stack->prop ? stack->prop->type : P_UNKNOWN;
1119 
1120 		if (stack->sym == last_sym)
1121 			fprintf(stderr, "error: recursive dependency detected!\n");
1122 
1123 		if (sym_is_choice(next_sym)) {
1124 			choice = list_first_entry(&next_sym->menus, struct menu, link);
1125 
1126 			fprintf(stderr, "\tsymbol %s is part of choice block at %s:%d\n",
1127 				sym->name ? sym->name : "<choice>",
1128 				choice->filename, choice->lineno);
1129 		} else if (stack->expr == &sym->dir_dep.expr) {
1130 			fprintf(stderr, "\tsymbol %s depends on %s\n",
1131 				sym->name ? sym->name : "<choice>",
1132 				next_sym->name);
1133 		} else if (stack->expr == &sym->rev_dep.expr) {
1134 			fprintf(stderr, "\tsymbol %s is selected by %s\n",
1135 				sym->name, next_sym->name);
1136 		} else if (stack->expr == &sym->implied.expr) {
1137 			fprintf(stderr, "\tsymbol %s is implied by %s\n",
1138 				sym->name, next_sym->name);
1139 		} else if (stack->expr) {
1140 			fprintf(stderr, "\tsymbol %s %s value contains %s\n",
1141 				sym->name ? sym->name : "<choice>",
1142 				prop_get_type_name(type),
1143 				next_sym->name);
1144 		} else {
1145 			fprintf(stderr, "\tsymbol %s %s is visible depending on %s\n",
1146 				sym->name ? sym->name : "<choice>",
1147 				prop_get_type_name(type),
1148 				next_sym->name);
1149 		}
1150 	}
1151 
1152 	fprintf(stderr,
1153 		"For a resolution refer to Documentation/kbuild/kconfig-language.rst\n"
1154 		"subsection \"Kconfig recursive dependency limitations\"\n"
1155 		"\n");
1156 
1157 	if (check_top == &cv_stack)
1158 		dep_stack_remove();
1159 }
1160 
sym_check_expr_deps(const struct expr * e)1161 static struct symbol *sym_check_expr_deps(const struct expr *e)
1162 {
1163 	struct symbol *sym;
1164 
1165 	if (!e)
1166 		return NULL;
1167 	switch (e->type) {
1168 	case E_OR:
1169 	case E_AND:
1170 		sym = sym_check_expr_deps(e->left.expr);
1171 		if (sym)
1172 			return sym;
1173 		return sym_check_expr_deps(e->right.expr);
1174 	case E_NOT:
1175 		return sym_check_expr_deps(e->left.expr);
1176 	case E_EQUAL:
1177 	case E_GEQ:
1178 	case E_GTH:
1179 	case E_LEQ:
1180 	case E_LTH:
1181 	case E_UNEQUAL:
1182 		sym = sym_check_deps(e->left.sym);
1183 		if (sym)
1184 			return sym;
1185 		return sym_check_deps(e->right.sym);
1186 	case E_SYMBOL:
1187 		return sym_check_deps(e->left.sym);
1188 	default:
1189 		break;
1190 	}
1191 	fprintf(stderr, "Oops! How to check %d?\n", e->type);
1192 	return NULL;
1193 }
1194 
1195 /* return NULL when dependencies are OK */
sym_check_sym_deps(struct symbol * sym)1196 static struct symbol *sym_check_sym_deps(struct symbol *sym)
1197 {
1198 	struct symbol *sym2;
1199 	struct property *prop;
1200 	struct dep_stack stack;
1201 
1202 	dep_stack_insert(&stack, sym);
1203 
1204 	stack.expr = &sym->dir_dep.expr;
1205 	sym2 = sym_check_expr_deps(sym->dir_dep.expr);
1206 	if (sym2)
1207 		goto out;
1208 
1209 	stack.expr = &sym->rev_dep.expr;
1210 	sym2 = sym_check_expr_deps(sym->rev_dep.expr);
1211 	if (sym2)
1212 		goto out;
1213 
1214 	stack.expr = &sym->implied.expr;
1215 	sym2 = sym_check_expr_deps(sym->implied.expr);
1216 	if (sym2)
1217 		goto out;
1218 
1219 	stack.expr = NULL;
1220 
1221 	for (prop = sym->prop; prop; prop = prop->next) {
1222 		if (prop->type == P_SELECT || prop->type == P_IMPLY)
1223 			continue;
1224 		stack.prop = prop;
1225 		sym2 = sym_check_expr_deps(prop->visible.expr);
1226 		if (sym2)
1227 			break;
1228 		if (prop->type != P_DEFAULT || sym_is_choice(sym))
1229 			continue;
1230 		stack.expr = &prop->expr;
1231 		sym2 = sym_check_expr_deps(prop->expr);
1232 		if (sym2)
1233 			break;
1234 		stack.expr = NULL;
1235 	}
1236 
1237 out:
1238 	dep_stack_remove();
1239 
1240 	return sym2;
1241 }
1242 
sym_check_choice_deps(struct symbol * choice)1243 static struct symbol *sym_check_choice_deps(struct symbol *choice)
1244 {
1245 	struct menu *choice_menu, *menu;
1246 	struct symbol *sym2;
1247 	struct dep_stack stack;
1248 
1249 	dep_stack_insert(&stack, choice);
1250 
1251 	choice_menu = list_first_entry(&choice->menus, struct menu, link);
1252 
1253 	menu_for_each_sub_entry(menu, choice_menu) {
1254 		if (menu->sym)
1255 			menu->sym->flags |= SYMBOL_CHECK | SYMBOL_CHECKED;
1256 	}
1257 
1258 	choice->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1259 	sym2 = sym_check_sym_deps(choice);
1260 	choice->flags &= ~SYMBOL_CHECK;
1261 	if (sym2)
1262 		goto out;
1263 
1264 	menu_for_each_sub_entry(menu, choice_menu) {
1265 		if (!menu->sym)
1266 			continue;
1267 		sym2 = sym_check_sym_deps(menu->sym);
1268 		if (sym2)
1269 			break;
1270 	}
1271 out:
1272 	menu_for_each_sub_entry(menu, choice_menu)
1273 		if (menu->sym)
1274 			menu->sym->flags &= ~SYMBOL_CHECK;
1275 
1276 	if (sym2) {
1277 		struct menu *choice_menu2;
1278 
1279 		choice_menu2 = sym_get_choice_menu(sym2);
1280 		if (choice_menu2 == choice_menu)
1281 			sym2 = choice;
1282 	}
1283 
1284 	dep_stack_remove();
1285 
1286 	return sym2;
1287 }
1288 
sym_check_deps(struct symbol * sym)1289 struct symbol *sym_check_deps(struct symbol *sym)
1290 {
1291 	struct menu *choice;
1292 	struct symbol *sym2;
1293 
1294 	if (sym->flags & SYMBOL_CHECK) {
1295 		sym_check_print_recursive(sym);
1296 		return sym;
1297 	}
1298 	if (sym->flags & SYMBOL_CHECKED)
1299 		return NULL;
1300 
1301 	choice = sym_get_choice_menu(sym);
1302 	if (choice) {
1303 		struct dep_stack stack;
1304 
1305 		/* for choice groups start the check with main choice symbol */
1306 		dep_stack_insert(&stack, sym);
1307 		sym2 = sym_check_deps(choice->sym);
1308 		dep_stack_remove();
1309 	} else if (sym_is_choice(sym)) {
1310 		sym2 = sym_check_choice_deps(sym);
1311 	} else {
1312 		sym->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1313 		sym2 = sym_check_sym_deps(sym);
1314 		sym->flags &= ~SYMBOL_CHECK;
1315 	}
1316 
1317 	return sym2;
1318 }
1319 
prop_get_symbol(const struct property * prop)1320 struct symbol *prop_get_symbol(const struct property *prop)
1321 {
1322 	if (prop->expr && prop->expr->type == E_SYMBOL)
1323 		return prop->expr->left.sym;
1324 	return NULL;
1325 }
1326 
prop_get_type_name(enum prop_type type)1327 const char *prop_get_type_name(enum prop_type type)
1328 {
1329 	switch (type) {
1330 	case P_PROMPT:
1331 		return "prompt";
1332 	case P_COMMENT:
1333 		return "comment";
1334 	case P_MENU:
1335 		return "menu";
1336 	case P_DEFAULT:
1337 		return "default";
1338 	case P_SELECT:
1339 		return "select";
1340 	case P_IMPLY:
1341 		return "imply";
1342 	case P_RANGE:
1343 		return "range";
1344 	case P_UNKNOWN:
1345 		break;
1346 	}
1347 	return "unknown";
1348 }
1349