xref: /linux/scripts/kconfig/symbol.c (revision a1ff5a7d78a036d6c2178ee5acd6ba4946243800)
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 
15 struct 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 
23 struct 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 
31 struct 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 
39 struct symbol *modules_sym;
40 static tristate modules_val;
41 static int sym_warnings;
42 
sym_get_type(const struct symbol * sym)43 enum symbol_type sym_get_type(const struct symbol *sym)
44 {
45 	enum symbol_type type = sym->type;
46 
47 	if (type == S_TRISTATE && modules_val == no)
48 		type = S_BOOLEAN;
49 	return type;
50 }
51 
sym_type_name(enum symbol_type type)52 const char *sym_type_name(enum symbol_type type)
53 {
54 	switch (type) {
55 	case S_BOOLEAN:
56 		return "bool";
57 	case S_TRISTATE:
58 		return "tristate";
59 	case S_INT:
60 		return "integer";
61 	case S_HEX:
62 		return "hex";
63 	case S_STRING:
64 		return "string";
65 	case S_UNKNOWN:
66 		return "unknown";
67 	}
68 	return "???";
69 }
70 
71 /**
72  * sym_get_choice_menu - get the parent choice menu if present
73  *
74  * @sym: a symbol pointer
75  *
76  * Return: a choice menu if this function is called against a choice member.
77  */
sym_get_choice_menu(const struct symbol * sym)78 struct menu *sym_get_choice_menu(const struct symbol *sym)
79 {
80 	struct menu *menu = NULL;
81 	struct menu *m;
82 
83 	/*
84 	 * Choice members must have a prompt. Find a menu entry with a prompt,
85 	 * and assume it resides inside a choice block.
86 	 */
87 	list_for_each_entry(m, &sym->menus, link)
88 		if (m->prompt) {
89 			menu = m;
90 			break;
91 		}
92 
93 	if (!menu)
94 		return NULL;
95 
96 	do {
97 		menu = menu->parent;
98 	} while (menu && !menu->sym);
99 
100 	if (menu && menu->sym && sym_is_choice(menu->sym))
101 		return menu;
102 
103 	return NULL;
104 }
105 
sym_get_default_prop(struct symbol * sym)106 static struct property *sym_get_default_prop(struct symbol *sym)
107 {
108 	struct property *prop;
109 
110 	for_all_defaults(sym, prop) {
111 		prop->visible.tri = expr_calc_value(prop->visible.expr);
112 		if (prop->visible.tri != no)
113 			return prop;
114 	}
115 	return NULL;
116 }
117 
sym_get_range_prop(struct symbol * sym)118 struct property *sym_get_range_prop(struct symbol *sym)
119 {
120 	struct property *prop;
121 
122 	for_all_properties(sym, prop, P_RANGE) {
123 		prop->visible.tri = expr_calc_value(prop->visible.expr);
124 		if (prop->visible.tri != no)
125 			return prop;
126 	}
127 	return NULL;
128 }
129 
sym_get_range_val(struct symbol * sym,int base)130 static long long sym_get_range_val(struct symbol *sym, int base)
131 {
132 	sym_calc_value(sym);
133 	switch (sym->type) {
134 	case S_INT:
135 		base = 10;
136 		break;
137 	case S_HEX:
138 		base = 16;
139 		break;
140 	default:
141 		break;
142 	}
143 	return strtoll(sym->curr.val, NULL, base);
144 }
145 
sym_validate_range(struct symbol * sym)146 static void sym_validate_range(struct symbol *sym)
147 {
148 	struct property *prop;
149 	struct symbol *range_sym;
150 	int base;
151 	long long val, val2;
152 
153 	switch (sym->type) {
154 	case S_INT:
155 		base = 10;
156 		break;
157 	case S_HEX:
158 		base = 16;
159 		break;
160 	default:
161 		return;
162 	}
163 	prop = sym_get_range_prop(sym);
164 	if (!prop)
165 		return;
166 	val = strtoll(sym->curr.val, NULL, base);
167 	range_sym = prop->expr->left.sym;
168 	val2 = sym_get_range_val(range_sym, base);
169 	if (val >= val2) {
170 		range_sym = prop->expr->right.sym;
171 		val2 = sym_get_range_val(range_sym, base);
172 		if (val <= val2)
173 			return;
174 	}
175 	sym->curr.val = range_sym->curr.val;
176 }
177 
sym_set_changed(struct symbol * sym)178 static void sym_set_changed(struct symbol *sym)
179 {
180 	struct menu *menu;
181 
182 	list_for_each_entry(menu, &sym->menus, link)
183 		menu->flags |= MENU_CHANGED;
184 }
185 
sym_set_all_changed(void)186 static void sym_set_all_changed(void)
187 {
188 	struct symbol *sym;
189 
190 	for_all_symbols(sym)
191 		sym_set_changed(sym);
192 }
193 
sym_calc_visibility(struct symbol * sym)194 static void sym_calc_visibility(struct symbol *sym)
195 {
196 	struct property *prop;
197 	tristate tri;
198 
199 	/* any prompt visible? */
200 	tri = no;
201 	for_all_prompts(sym, prop) {
202 		prop->visible.tri = expr_calc_value(prop->visible.expr);
203 		tri = EXPR_OR(tri, prop->visible.tri);
204 	}
205 	if (tri == mod && (sym->type != S_TRISTATE || modules_val == no))
206 		tri = yes;
207 	if (sym->visible != tri) {
208 		sym->visible = tri;
209 		sym_set_changed(sym);
210 	}
211 	if (sym_is_choice_value(sym))
212 		return;
213 	/* defaulting to "yes" if no explicit "depends on" are given */
214 	tri = yes;
215 	if (sym->dir_dep.expr)
216 		tri = expr_calc_value(sym->dir_dep.expr);
217 	if (tri == mod && sym_get_type(sym) == S_BOOLEAN)
218 		tri = yes;
219 	if (sym->dir_dep.tri != tri) {
220 		sym->dir_dep.tri = tri;
221 		sym_set_changed(sym);
222 	}
223 	tri = no;
224 	if (sym->rev_dep.expr)
225 		tri = expr_calc_value(sym->rev_dep.expr);
226 	if (tri == mod && sym_get_type(sym) == S_BOOLEAN)
227 		tri = yes;
228 	if (sym->rev_dep.tri != tri) {
229 		sym->rev_dep.tri = tri;
230 		sym_set_changed(sym);
231 	}
232 	tri = no;
233 	if (sym->implied.expr)
234 		tri = expr_calc_value(sym->implied.expr);
235 	if (tri == mod && sym_get_type(sym) == S_BOOLEAN)
236 		tri = yes;
237 	if (sym->implied.tri != tri) {
238 		sym->implied.tri = tri;
239 		sym_set_changed(sym);
240 	}
241 }
242 
243 /*
244  * Find the default symbol for a choice.
245  * First try the default values for the choice symbol
246  * Next locate the first visible choice value
247  * Return NULL if none was found
248  */
sym_choice_default(struct menu * choice)249 struct symbol *sym_choice_default(struct menu *choice)
250 {
251 	struct menu *menu;
252 	struct symbol *def_sym;
253 	struct property *prop;
254 
255 	/* any of the defaults visible? */
256 	for_all_defaults(choice->sym, prop) {
257 		prop->visible.tri = expr_calc_value(prop->visible.expr);
258 		if (prop->visible.tri == no)
259 			continue;
260 		def_sym = prop_get_symbol(prop);
261 		if (def_sym->visible != no)
262 			return def_sym;
263 	}
264 
265 	/* just get the first visible value */
266 	menu_for_each_sub_entry(menu, choice)
267 		if (menu->sym && menu->sym->visible != no)
268 			return menu->sym;
269 
270 	/* failed to locate any defaults */
271 	return NULL;
272 }
273 
274 /*
275  * sym_calc_choice - calculate symbol values in a choice
276  *
277  * @choice: a menu of the choice
278  *
279  * Return: a chosen symbol
280  */
sym_calc_choice(struct menu * choice)281 struct symbol *sym_calc_choice(struct menu *choice)
282 {
283 	struct symbol *res = NULL;
284 	struct symbol *sym;
285 	struct menu *menu;
286 
287 	/* Traverse the list of choice members in the priority order. */
288 	list_for_each_entry(sym, &choice->choice_members, choice_link) {
289 		sym_calc_visibility(sym);
290 		if (sym->visible == no)
291 			continue;
292 
293 		/* The first visible symble with the user value 'y'. */
294 		if (sym_has_value(sym) && sym->def[S_DEF_USER].tri == yes) {
295 			res = sym;
296 			break;
297 		}
298 	}
299 
300 	/*
301 	 * If 'y' is not found in the user input, use the default, unless it is
302 	 * explicitly set to 'n'.
303 	 */
304 	if (!res) {
305 		res = sym_choice_default(choice);
306 		if (res && sym_has_value(res) && res->def[S_DEF_USER].tri == no)
307 			res = NULL;
308 	}
309 
310 	/* Still not found. Pick up the first visible, user-unspecified symbol. */
311 	if (!res) {
312 		menu_for_each_sub_entry(menu, choice) {
313 			sym = menu->sym;
314 
315 			if (!sym || sym->visible == no || sym_has_value(sym))
316 				continue;
317 
318 			res = sym;
319 			break;
320 		}
321 	}
322 
323 	/*
324 	 * Still not found. Traverse the linked list in the _reverse_ order to
325 	 * pick up the least prioritized 'n'.
326 	 */
327 	if (!res) {
328 		list_for_each_entry_reverse(sym, &choice->choice_members,
329 					    choice_link) {
330 			if (sym->visible == no)
331 				continue;
332 
333 			res = sym;
334 			break;
335 		}
336 	}
337 
338 	menu_for_each_sub_entry(menu, choice) {
339 		tristate val;
340 
341 		sym = menu->sym;
342 
343 		if (!sym || sym->visible == no)
344 			continue;
345 
346 		val = sym == res ? yes : no;
347 
348 		if (sym->curr.tri != val)
349 			sym_set_changed(sym);
350 
351 		sym->curr.tri = val;
352 		sym->flags |= SYMBOL_VALID | SYMBOL_WRITE;
353 	}
354 
355 	return res;
356 }
357 
sym_warn_unmet_dep(const struct symbol * sym)358 static void sym_warn_unmet_dep(const struct symbol *sym)
359 {
360 	struct gstr gs = str_new();
361 
362 	str_printf(&gs,
363 		   "\nWARNING: unmet direct dependencies detected for %s\n",
364 		   sym->name);
365 	str_printf(&gs,
366 		   "  Depends on [%c]: ",
367 		   sym->dir_dep.tri == mod ? 'm' : 'n');
368 	expr_gstr_print(sym->dir_dep.expr, &gs);
369 	str_printf(&gs, "\n");
370 
371 	expr_gstr_print_revdep(sym->rev_dep.expr, &gs, yes,
372 			       "  Selected by [y]:\n");
373 	expr_gstr_print_revdep(sym->rev_dep.expr, &gs, mod,
374 			       "  Selected by [m]:\n");
375 
376 	fputs(str_get(&gs), stderr);
377 	sym_warnings++;
378 }
379 
sym_dep_errors(void)380 bool sym_dep_errors(void)
381 {
382 	if (sym_warnings)
383 		return getenv("KCONFIG_WERROR");
384 	return false;
385 }
386 
sym_calc_value(struct symbol * sym)387 void sym_calc_value(struct symbol *sym)
388 {
389 	struct symbol_value newval, oldval;
390 	struct property *prop;
391 	struct menu *choice_menu;
392 
393 	if (!sym)
394 		return;
395 
396 	if (sym->flags & SYMBOL_VALID)
397 		return;
398 
399 	sym->flags |= SYMBOL_VALID;
400 
401 	oldval = sym->curr;
402 
403 	newval.tri = no;
404 
405 	switch (sym->type) {
406 	case S_INT:
407 		newval.val = "0";
408 		break;
409 	case S_HEX:
410 		newval.val = "0x0";
411 		break;
412 	case S_STRING:
413 		newval.val = "";
414 		break;
415 	case S_BOOLEAN:
416 	case S_TRISTATE:
417 		newval.val = "n";
418 		break;
419 	default:
420 		sym->curr.val = sym->name;
421 		sym->curr.tri = no;
422 		return;
423 	}
424 	sym->flags &= ~SYMBOL_WRITE;
425 
426 	sym_calc_visibility(sym);
427 
428 	if (sym->visible != no)
429 		sym->flags |= SYMBOL_WRITE;
430 
431 	/* set default if recursively called */
432 	sym->curr = newval;
433 
434 	switch (sym_get_type(sym)) {
435 	case S_BOOLEAN:
436 	case S_TRISTATE:
437 		choice_menu = sym_get_choice_menu(sym);
438 
439 		if (choice_menu) {
440 			sym_calc_choice(choice_menu);
441 			newval.tri = sym->curr.tri;
442 		} else {
443 			if (sym->visible != no) {
444 				/* if the symbol is visible use the user value
445 				 * if available, otherwise try the default value
446 				 */
447 				if (sym_has_value(sym)) {
448 					newval.tri = EXPR_AND(sym->def[S_DEF_USER].tri,
449 							      sym->visible);
450 					goto calc_newval;
451 				}
452 			}
453 			if (sym->rev_dep.tri != no)
454 				sym->flags |= SYMBOL_WRITE;
455 			if (!sym_is_choice(sym)) {
456 				prop = sym_get_default_prop(sym);
457 				if (prop) {
458 					newval.tri = EXPR_AND(expr_calc_value(prop->expr),
459 							      prop->visible.tri);
460 					if (newval.tri != no)
461 						sym->flags |= SYMBOL_WRITE;
462 				}
463 				if (sym->implied.tri != no) {
464 					sym->flags |= SYMBOL_WRITE;
465 					newval.tri = EXPR_OR(newval.tri, sym->implied.tri);
466 					newval.tri = EXPR_AND(newval.tri,
467 							      sym->dir_dep.tri);
468 				}
469 			}
470 		calc_newval:
471 			if (sym->dir_dep.tri < sym->rev_dep.tri)
472 				sym_warn_unmet_dep(sym);
473 			newval.tri = EXPR_OR(newval.tri, sym->rev_dep.tri);
474 		}
475 		if (newval.tri == mod && sym_get_type(sym) == S_BOOLEAN)
476 			newval.tri = yes;
477 		break;
478 	case S_STRING:
479 	case S_HEX:
480 	case S_INT:
481 		if (sym->visible != no && sym_has_value(sym)) {
482 			newval.val = sym->def[S_DEF_USER].val;
483 			break;
484 		}
485 		prop = sym_get_default_prop(sym);
486 		if (prop) {
487 			struct symbol *ds = prop_get_symbol(prop);
488 			if (ds) {
489 				sym->flags |= SYMBOL_WRITE;
490 				sym_calc_value(ds);
491 				newval.val = ds->curr.val;
492 			}
493 		}
494 		break;
495 	default:
496 		;
497 	}
498 
499 	sym->curr = newval;
500 	sym_validate_range(sym);
501 
502 	if (memcmp(&oldval, &sym->curr, sizeof(oldval))) {
503 		sym_set_changed(sym);
504 		if (modules_sym == sym) {
505 			sym_set_all_changed();
506 			modules_val = modules_sym->curr.tri;
507 		}
508 	}
509 
510 	if (sym_is_choice(sym))
511 		sym->flags &= ~SYMBOL_WRITE;
512 }
513 
sym_clear_all_valid(void)514 void sym_clear_all_valid(void)
515 {
516 	struct symbol *sym;
517 
518 	for_all_symbols(sym)
519 		sym->flags &= ~SYMBOL_VALID;
520 	conf_set_changed(true);
521 	sym_calc_value(modules_sym);
522 }
523 
sym_tristate_within_range(const struct symbol * sym,tristate val)524 bool sym_tristate_within_range(const struct symbol *sym, tristate val)
525 {
526 	int type = sym_get_type(sym);
527 
528 	if (sym->visible == no)
529 		return false;
530 
531 	if (type != S_BOOLEAN && type != S_TRISTATE)
532 		return false;
533 
534 	if (type == S_BOOLEAN && val == mod)
535 		return false;
536 	if (sym->visible <= sym->rev_dep.tri)
537 		return false;
538 	return val >= sym->rev_dep.tri && val <= sym->visible;
539 }
540 
sym_set_tristate_value(struct symbol * sym,tristate val)541 bool sym_set_tristate_value(struct symbol *sym, tristate val)
542 {
543 	tristate oldval = sym_get_tristate_value(sym);
544 
545 	if (!sym_tristate_within_range(sym, val))
546 		return false;
547 
548 	if (!(sym->flags & SYMBOL_DEF_USER) || sym->def[S_DEF_USER].tri != val) {
549 		sym->def[S_DEF_USER].tri = val;
550 		sym->flags |= SYMBOL_DEF_USER;
551 		sym_set_changed(sym);
552 	}
553 
554 	if (oldval != val)
555 		sym_clear_all_valid();
556 
557 	return true;
558 }
559 
560 /**
561  * choice_set_value - set the user input to a choice
562  *
563  * @choice: menu entry for the choice
564  * @sym: selected symbol
565  */
choice_set_value(struct menu * choice,struct symbol * sym)566 void choice_set_value(struct menu *choice, struct symbol *sym)
567 {
568 	struct menu *menu;
569 	bool changed = false;
570 
571 	menu_for_each_sub_entry(menu, choice) {
572 		tristate val;
573 
574 		if (!menu->sym)
575 			continue;
576 
577 		if (menu->sym->visible == no)
578 			continue;
579 
580 		val = menu->sym == sym ? yes : no;
581 
582 		if (menu->sym->curr.tri != val)
583 			changed = true;
584 
585 		menu->sym->def[S_DEF_USER].tri = val;
586 		menu->sym->flags |= SYMBOL_DEF_USER;
587 
588 		/*
589 		 * Now, the user has explicitly enabled or disabled this symbol,
590 		 * it should be given the highest priority. We are possibly
591 		 * setting multiple symbols to 'n', where the first symbol is
592 		 * given the least prioritized 'n'. This works well when the
593 		 * choice block ends up with selecting 'n' symbol.
594 		 * (see sym_calc_choice())
595 		 */
596 		list_move(&menu->sym->choice_link, &choice->choice_members);
597 	}
598 
599 	if (changed)
600 		sym_clear_all_valid();
601 }
602 
sym_toggle_tristate_value(struct symbol * sym)603 tristate sym_toggle_tristate_value(struct symbol *sym)
604 {
605 	struct menu *choice;
606 	tristate oldval, newval;
607 
608 	choice = sym_get_choice_menu(sym);
609 	if (choice) {
610 		choice_set_value(choice, sym);
611 		return yes;
612 	}
613 
614 	oldval = newval = sym_get_tristate_value(sym);
615 	do {
616 		switch (newval) {
617 		case no:
618 			newval = mod;
619 			break;
620 		case mod:
621 			newval = yes;
622 			break;
623 		case yes:
624 			newval = no;
625 			break;
626 		}
627 		if (sym_set_tristate_value(sym, newval))
628 			break;
629 	} while (oldval != newval);
630 	return newval;
631 }
632 
sym_string_valid(struct symbol * sym,const char * str)633 bool sym_string_valid(struct symbol *sym, const char *str)
634 {
635 	signed char ch;
636 
637 	switch (sym->type) {
638 	case S_STRING:
639 		return true;
640 	case S_INT:
641 		ch = *str++;
642 		if (ch == '-')
643 			ch = *str++;
644 		if (!isdigit(ch))
645 			return false;
646 		if (ch == '0' && *str != 0)
647 			return false;
648 		while ((ch = *str++)) {
649 			if (!isdigit(ch))
650 				return false;
651 		}
652 		return true;
653 	case S_HEX:
654 		if (str[0] == '0' && (str[1] == 'x' || str[1] == 'X'))
655 			str += 2;
656 		ch = *str++;
657 		do {
658 			if (!isxdigit(ch))
659 				return false;
660 		} while ((ch = *str++));
661 		return true;
662 	case S_BOOLEAN:
663 	case S_TRISTATE:
664 		switch (str[0]) {
665 		case 'y': case 'Y':
666 		case 'm': case 'M':
667 		case 'n': case 'N':
668 			return true;
669 		}
670 		return false;
671 	default:
672 		return false;
673 	}
674 }
675 
sym_string_within_range(struct symbol * sym,const char * str)676 bool sym_string_within_range(struct symbol *sym, const char *str)
677 {
678 	struct property *prop;
679 	long long val;
680 
681 	switch (sym->type) {
682 	case S_STRING:
683 		return sym_string_valid(sym, str);
684 	case S_INT:
685 		if (!sym_string_valid(sym, str))
686 			return false;
687 		prop = sym_get_range_prop(sym);
688 		if (!prop)
689 			return true;
690 		val = strtoll(str, NULL, 10);
691 		return val >= sym_get_range_val(prop->expr->left.sym, 10) &&
692 		       val <= sym_get_range_val(prop->expr->right.sym, 10);
693 	case S_HEX:
694 		if (!sym_string_valid(sym, str))
695 			return false;
696 		prop = sym_get_range_prop(sym);
697 		if (!prop)
698 			return true;
699 		val = strtoll(str, NULL, 16);
700 		return val >= sym_get_range_val(prop->expr->left.sym, 16) &&
701 		       val <= sym_get_range_val(prop->expr->right.sym, 16);
702 	case S_BOOLEAN:
703 	case S_TRISTATE:
704 		switch (str[0]) {
705 		case 'y': case 'Y':
706 			return sym_tristate_within_range(sym, yes);
707 		case 'm': case 'M':
708 			return sym_tristate_within_range(sym, mod);
709 		case 'n': case 'N':
710 			return sym_tristate_within_range(sym, no);
711 		}
712 		return false;
713 	default:
714 		return false;
715 	}
716 }
717 
sym_set_string_value(struct symbol * sym,const char * newval)718 bool sym_set_string_value(struct symbol *sym, const char *newval)
719 {
720 	const char *oldval;
721 	char *val;
722 	int size;
723 
724 	switch (sym->type) {
725 	case S_BOOLEAN:
726 	case S_TRISTATE:
727 		switch (newval[0]) {
728 		case 'y': case 'Y':
729 			return sym_set_tristate_value(sym, yes);
730 		case 'm': case 'M':
731 			return sym_set_tristate_value(sym, mod);
732 		case 'n': case 'N':
733 			return sym_set_tristate_value(sym, no);
734 		}
735 		return false;
736 	default:
737 		;
738 	}
739 
740 	if (!sym_string_within_range(sym, newval))
741 		return false;
742 
743 	if (!(sym->flags & SYMBOL_DEF_USER)) {
744 		sym->flags |= SYMBOL_DEF_USER;
745 		sym_set_changed(sym);
746 	}
747 
748 	oldval = sym->def[S_DEF_USER].val;
749 	size = strlen(newval) + 1;
750 	if (sym->type == S_HEX && (newval[0] != '0' || (newval[1] != 'x' && newval[1] != 'X'))) {
751 		size += 2;
752 		sym->def[S_DEF_USER].val = val = xmalloc(size);
753 		*val++ = '0';
754 		*val++ = 'x';
755 	} else if (!oldval || strcmp(oldval, newval))
756 		sym->def[S_DEF_USER].val = val = xmalloc(size);
757 	else
758 		return true;
759 
760 	strcpy(val, newval);
761 	free((void *)oldval);
762 	sym_clear_all_valid();
763 
764 	return true;
765 }
766 
767 /*
768  * Find the default value associated to a symbol.
769  * For tristate symbol handle the modules=n case
770  * in which case "m" becomes "y".
771  * If the symbol does not have any default then fallback
772  * to the fixed default values.
773  */
sym_get_string_default(struct symbol * sym)774 const char *sym_get_string_default(struct symbol *sym)
775 {
776 	struct property *prop;
777 	struct symbol *ds;
778 	const char *str = "";
779 	tristate val;
780 
781 	sym_calc_visibility(sym);
782 	sym_calc_value(modules_sym);
783 	val = symbol_no.curr.tri;
784 
785 	/* If symbol has a default value look it up */
786 	prop = sym_get_default_prop(sym);
787 	if (prop != NULL) {
788 		switch (sym->type) {
789 		case S_BOOLEAN:
790 		case S_TRISTATE:
791 			/* The visibility may limit the value from yes => mod */
792 			val = EXPR_AND(expr_calc_value(prop->expr), prop->visible.tri);
793 			break;
794 		default:
795 			/*
796 			 * The following fails to handle the situation
797 			 * where a default value is further limited by
798 			 * the valid range.
799 			 */
800 			ds = prop_get_symbol(prop);
801 			if (ds != NULL) {
802 				sym_calc_value(ds);
803 				str = (const char *)ds->curr.val;
804 			}
805 		}
806 	}
807 
808 	/* Handle select statements */
809 	val = EXPR_OR(val, sym->rev_dep.tri);
810 
811 	/* transpose mod to yes if modules are not enabled */
812 	if (val == mod)
813 		if (!sym_is_choice_value(sym) && modules_sym->curr.tri == no)
814 			val = yes;
815 
816 	/* transpose mod to yes if type is bool */
817 	if (sym->type == S_BOOLEAN && val == mod)
818 		val = yes;
819 
820 	/* adjust the default value if this symbol is implied by another */
821 	if (val < sym->implied.tri)
822 		val = sym->implied.tri;
823 
824 	switch (sym->type) {
825 	case S_BOOLEAN:
826 	case S_TRISTATE:
827 		switch (val) {
828 		case no: return "n";
829 		case mod: return "m";
830 		case yes: return "y";
831 		}
832 	case S_INT:
833 		if (!str[0])
834 			str = "0";
835 		break;
836 	case S_HEX:
837 		if (!str[0])
838 			str = "0x0";
839 		break;
840 	default:
841 		break;
842 	}
843 	return str;
844 }
845 
sym_get_string_value(struct symbol * sym)846 const char *sym_get_string_value(struct symbol *sym)
847 {
848 	tristate val;
849 
850 	switch (sym->type) {
851 	case S_BOOLEAN:
852 	case S_TRISTATE:
853 		val = sym_get_tristate_value(sym);
854 		switch (val) {
855 		case no:
856 			return "n";
857 		case mod:
858 			return "m";
859 		case yes:
860 			return "y";
861 		}
862 		break;
863 	default:
864 		;
865 	}
866 	return (const char *)sym->curr.val;
867 }
868 
sym_is_changeable(const struct symbol * sym)869 bool sym_is_changeable(const struct symbol *sym)
870 {
871 	return !sym_is_choice(sym) && sym->visible > sym->rev_dep.tri;
872 }
873 
sym_is_choice_value(const struct symbol * sym)874 bool sym_is_choice_value(const struct symbol *sym)
875 {
876 	return !list_empty(&sym->choice_link);
877 }
878 
879 HASHTABLE_DEFINE(sym_hashtable, SYMBOL_HASHSIZE);
880 
sym_lookup(const char * name,int flags)881 struct symbol *sym_lookup(const char *name, int flags)
882 {
883 	struct symbol *symbol;
884 	char *new_name;
885 	int hash;
886 
887 	if (name) {
888 		if (name[0] && !name[1]) {
889 			switch (name[0]) {
890 			case 'y': return &symbol_yes;
891 			case 'm': return &symbol_mod;
892 			case 'n': return &symbol_no;
893 			}
894 		}
895 		hash = strhash(name);
896 
897 		hash_for_each_possible(sym_hashtable, symbol, node, hash) {
898 			if (symbol->name &&
899 			    !strcmp(symbol->name, name) &&
900 			    (flags ? symbol->flags & flags
901 				   : !(symbol->flags & SYMBOL_CONST)))
902 				return symbol;
903 		}
904 		new_name = xstrdup(name);
905 	} else {
906 		new_name = NULL;
907 		hash = 0;
908 	}
909 
910 	symbol = xmalloc(sizeof(*symbol));
911 	memset(symbol, 0, sizeof(*symbol));
912 	symbol->name = new_name;
913 	symbol->type = S_UNKNOWN;
914 	symbol->flags = flags;
915 	INIT_LIST_HEAD(&symbol->menus);
916 	INIT_LIST_HEAD(&symbol->choice_link);
917 
918 	hash_add(sym_hashtable, &symbol->node, hash);
919 
920 	return symbol;
921 }
922 
sym_find(const char * name)923 struct symbol *sym_find(const char *name)
924 {
925 	struct symbol *symbol = NULL;
926 	int hash = 0;
927 
928 	if (!name)
929 		return NULL;
930 
931 	if (name[0] && !name[1]) {
932 		switch (name[0]) {
933 		case 'y': return &symbol_yes;
934 		case 'm': return &symbol_mod;
935 		case 'n': return &symbol_no;
936 		}
937 	}
938 	hash = strhash(name);
939 
940 	hash_for_each_possible(sym_hashtable, symbol, node, hash) {
941 		if (symbol->name &&
942 		    !strcmp(symbol->name, name) &&
943 		    !(symbol->flags & SYMBOL_CONST))
944 				break;
945 	}
946 
947 	return symbol;
948 }
949 
950 struct sym_match {
951 	struct symbol	*sym;
952 	off_t		so, eo;
953 };
954 
955 /* Compare matched symbols as thus:
956  * - first, symbols that match exactly
957  * - then, alphabetical sort
958  */
sym_rel_comp(const void * sym1,const void * sym2)959 static int sym_rel_comp(const void *sym1, const void *sym2)
960 {
961 	const struct sym_match *s1 = sym1;
962 	const struct sym_match *s2 = sym2;
963 	int exact1, exact2;
964 
965 	/* Exact match:
966 	 * - if matched length on symbol s1 is the length of that symbol,
967 	 *   then this symbol should come first;
968 	 * - if matched length on symbol s2 is the length of that symbol,
969 	 *   then this symbol should come first.
970 	 * Note: since the search can be a regexp, both symbols may match
971 	 * exactly; if this is the case, we can't decide which comes first,
972 	 * and we fallback to sorting alphabetically.
973 	 */
974 	exact1 = (s1->eo - s1->so) == strlen(s1->sym->name);
975 	exact2 = (s2->eo - s2->so) == strlen(s2->sym->name);
976 	if (exact1 && !exact2)
977 		return -1;
978 	if (!exact1 && exact2)
979 		return 1;
980 
981 	/* As a fallback, sort symbols alphabetically */
982 	return strcmp(s1->sym->name, s2->sym->name);
983 }
984 
sym_re_search(const char * pattern)985 struct symbol **sym_re_search(const char *pattern)
986 {
987 	struct symbol *sym, **sym_arr = NULL;
988 	struct sym_match *sym_match_arr = NULL;
989 	int i, cnt, size;
990 	regex_t re;
991 	regmatch_t match[1];
992 
993 	cnt = size = 0;
994 	/* Skip if empty */
995 	if (strlen(pattern) == 0)
996 		return NULL;
997 	if (regcomp(&re, pattern, REG_EXTENDED|REG_ICASE))
998 		return NULL;
999 
1000 	for_all_symbols(sym) {
1001 		if (sym->flags & SYMBOL_CONST || !sym->name)
1002 			continue;
1003 		if (regexec(&re, sym->name, 1, match, 0))
1004 			continue;
1005 		if (cnt >= size) {
1006 			void *tmp;
1007 			size += 16;
1008 			tmp = realloc(sym_match_arr, size * sizeof(struct sym_match));
1009 			if (!tmp)
1010 				goto sym_re_search_free;
1011 			sym_match_arr = tmp;
1012 		}
1013 		sym_calc_value(sym);
1014 		/* As regexec returned 0, we know we have a match, so
1015 		 * we can use match[0].rm_[se]o without further checks
1016 		 */
1017 		sym_match_arr[cnt].so = match[0].rm_so;
1018 		sym_match_arr[cnt].eo = match[0].rm_eo;
1019 		sym_match_arr[cnt++].sym = sym;
1020 	}
1021 	if (sym_match_arr) {
1022 		qsort(sym_match_arr, cnt, sizeof(struct sym_match), sym_rel_comp);
1023 		sym_arr = malloc((cnt+1) * sizeof(struct symbol *));
1024 		if (!sym_arr)
1025 			goto sym_re_search_free;
1026 		for (i = 0; i < cnt; i++)
1027 			sym_arr[i] = sym_match_arr[i].sym;
1028 		sym_arr[cnt] = NULL;
1029 	}
1030 sym_re_search_free:
1031 	/* sym_match_arr can be NULL if no match, but free(NULL) is OK */
1032 	free(sym_match_arr);
1033 	regfree(&re);
1034 
1035 	return sym_arr;
1036 }
1037 
1038 /*
1039  * When we check for recursive dependencies we use a stack to save
1040  * current state so we can print out relevant info to user.
1041  * The entries are located on the call stack so no need to free memory.
1042  * Note insert() remove() must always match to properly clear the stack.
1043  */
1044 static struct dep_stack {
1045 	struct dep_stack *prev, *next;
1046 	struct symbol *sym;
1047 	struct property *prop;
1048 	struct expr **expr;
1049 } *check_top;
1050 
dep_stack_insert(struct dep_stack * stack,struct symbol * sym)1051 static void dep_stack_insert(struct dep_stack *stack, struct symbol *sym)
1052 {
1053 	memset(stack, 0, sizeof(*stack));
1054 	if (check_top)
1055 		check_top->next = stack;
1056 	stack->prev = check_top;
1057 	stack->sym = sym;
1058 	check_top = stack;
1059 }
1060 
dep_stack_remove(void)1061 static void dep_stack_remove(void)
1062 {
1063 	check_top = check_top->prev;
1064 	if (check_top)
1065 		check_top->next = NULL;
1066 }
1067 
1068 /*
1069  * Called when we have detected a recursive dependency.
1070  * check_top point to the top of the stact so we use
1071  * the ->prev pointer to locate the bottom of the stack.
1072  */
sym_check_print_recursive(struct symbol * last_sym)1073 static void sym_check_print_recursive(struct symbol *last_sym)
1074 {
1075 	struct dep_stack *stack;
1076 	struct symbol *sym, *next_sym;
1077 	struct menu *choice;
1078 	struct dep_stack cv_stack;
1079 	enum prop_type type;
1080 
1081 	choice = sym_get_choice_menu(last_sym);
1082 	if (choice) {
1083 		dep_stack_insert(&cv_stack, last_sym);
1084 		last_sym = choice->sym;
1085 	}
1086 
1087 	for (stack = check_top; stack != NULL; stack = stack->prev)
1088 		if (stack->sym == last_sym)
1089 			break;
1090 	if (!stack) {
1091 		fprintf(stderr, "unexpected recursive dependency error\n");
1092 		return;
1093 	}
1094 
1095 	for (; stack; stack = stack->next) {
1096 		sym = stack->sym;
1097 		next_sym = stack->next ? stack->next->sym : last_sym;
1098 		type = stack->prop ? stack->prop->type : P_UNKNOWN;
1099 
1100 		if (stack->sym == last_sym)
1101 			fprintf(stderr, "error: recursive dependency detected!\n");
1102 
1103 		if (sym_is_choice(next_sym)) {
1104 			choice = list_first_entry(&next_sym->menus, struct menu, link);
1105 
1106 			fprintf(stderr, "\tsymbol %s is part of choice block at %s:%d\n",
1107 				sym->name ? sym->name : "<choice>",
1108 				choice->filename, choice->lineno);
1109 		} else if (stack->expr == &sym->dir_dep.expr) {
1110 			fprintf(stderr, "\tsymbol %s depends on %s\n",
1111 				sym->name ? sym->name : "<choice>",
1112 				next_sym->name);
1113 		} else if (stack->expr == &sym->rev_dep.expr) {
1114 			fprintf(stderr, "\tsymbol %s is selected by %s\n",
1115 				sym->name, next_sym->name);
1116 		} else if (stack->expr == &sym->implied.expr) {
1117 			fprintf(stderr, "\tsymbol %s is implied by %s\n",
1118 				sym->name, next_sym->name);
1119 		} else if (stack->expr) {
1120 			fprintf(stderr, "\tsymbol %s %s value contains %s\n",
1121 				sym->name ? sym->name : "<choice>",
1122 				prop_get_type_name(type),
1123 				next_sym->name);
1124 		} else {
1125 			fprintf(stderr, "\tsymbol %s %s is visible depending on %s\n",
1126 				sym->name ? sym->name : "<choice>",
1127 				prop_get_type_name(type),
1128 				next_sym->name);
1129 		}
1130 	}
1131 
1132 	fprintf(stderr,
1133 		"For a resolution refer to Documentation/kbuild/kconfig-language.rst\n"
1134 		"subsection \"Kconfig recursive dependency limitations\"\n"
1135 		"\n");
1136 
1137 	if (check_top == &cv_stack)
1138 		dep_stack_remove();
1139 }
1140 
sym_check_expr_deps(const struct expr * e)1141 static struct symbol *sym_check_expr_deps(const struct expr *e)
1142 {
1143 	struct symbol *sym;
1144 
1145 	if (!e)
1146 		return NULL;
1147 	switch (e->type) {
1148 	case E_OR:
1149 	case E_AND:
1150 		sym = sym_check_expr_deps(e->left.expr);
1151 		if (sym)
1152 			return sym;
1153 		return sym_check_expr_deps(e->right.expr);
1154 	case E_NOT:
1155 		return sym_check_expr_deps(e->left.expr);
1156 	case E_EQUAL:
1157 	case E_GEQ:
1158 	case E_GTH:
1159 	case E_LEQ:
1160 	case E_LTH:
1161 	case E_UNEQUAL:
1162 		sym = sym_check_deps(e->left.sym);
1163 		if (sym)
1164 			return sym;
1165 		return sym_check_deps(e->right.sym);
1166 	case E_SYMBOL:
1167 		return sym_check_deps(e->left.sym);
1168 	default:
1169 		break;
1170 	}
1171 	fprintf(stderr, "Oops! How to check %d?\n", e->type);
1172 	return NULL;
1173 }
1174 
1175 /* return NULL when dependencies are OK */
sym_check_sym_deps(struct symbol * sym)1176 static struct symbol *sym_check_sym_deps(struct symbol *sym)
1177 {
1178 	struct symbol *sym2;
1179 	struct property *prop;
1180 	struct dep_stack stack;
1181 
1182 	dep_stack_insert(&stack, sym);
1183 
1184 	stack.expr = &sym->dir_dep.expr;
1185 	sym2 = sym_check_expr_deps(sym->dir_dep.expr);
1186 	if (sym2)
1187 		goto out;
1188 
1189 	stack.expr = &sym->rev_dep.expr;
1190 	sym2 = sym_check_expr_deps(sym->rev_dep.expr);
1191 	if (sym2)
1192 		goto out;
1193 
1194 	stack.expr = &sym->implied.expr;
1195 	sym2 = sym_check_expr_deps(sym->implied.expr);
1196 	if (sym2)
1197 		goto out;
1198 
1199 	stack.expr = NULL;
1200 
1201 	for (prop = sym->prop; prop; prop = prop->next) {
1202 		if (prop->type == P_SELECT || prop->type == P_IMPLY)
1203 			continue;
1204 		stack.prop = prop;
1205 		sym2 = sym_check_expr_deps(prop->visible.expr);
1206 		if (sym2)
1207 			break;
1208 		if (prop->type != P_DEFAULT || sym_is_choice(sym))
1209 			continue;
1210 		stack.expr = &prop->expr;
1211 		sym2 = sym_check_expr_deps(prop->expr);
1212 		if (sym2)
1213 			break;
1214 		stack.expr = NULL;
1215 	}
1216 
1217 out:
1218 	dep_stack_remove();
1219 
1220 	return sym2;
1221 }
1222 
sym_check_choice_deps(struct symbol * choice)1223 static struct symbol *sym_check_choice_deps(struct symbol *choice)
1224 {
1225 	struct menu *choice_menu, *menu;
1226 	struct symbol *sym2;
1227 	struct dep_stack stack;
1228 
1229 	dep_stack_insert(&stack, choice);
1230 
1231 	choice_menu = list_first_entry(&choice->menus, struct menu, link);
1232 
1233 	menu_for_each_sub_entry(menu, choice_menu) {
1234 		if (menu->sym)
1235 			menu->sym->flags |= SYMBOL_CHECK | SYMBOL_CHECKED;
1236 	}
1237 
1238 	choice->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1239 	sym2 = sym_check_sym_deps(choice);
1240 	choice->flags &= ~SYMBOL_CHECK;
1241 	if (sym2)
1242 		goto out;
1243 
1244 	menu_for_each_sub_entry(menu, choice_menu) {
1245 		if (!menu->sym)
1246 			continue;
1247 		sym2 = sym_check_sym_deps(menu->sym);
1248 		if (sym2)
1249 			break;
1250 	}
1251 out:
1252 	menu_for_each_sub_entry(menu, choice_menu)
1253 		if (menu->sym)
1254 			menu->sym->flags &= ~SYMBOL_CHECK;
1255 
1256 	if (sym2) {
1257 		struct menu *choice_menu2;
1258 
1259 		choice_menu2 = sym_get_choice_menu(sym2);
1260 		if (choice_menu2 == choice_menu)
1261 			sym2 = choice;
1262 	}
1263 
1264 	dep_stack_remove();
1265 
1266 	return sym2;
1267 }
1268 
sym_check_deps(struct symbol * sym)1269 struct symbol *sym_check_deps(struct symbol *sym)
1270 {
1271 	struct menu *choice;
1272 	struct symbol *sym2;
1273 
1274 	if (sym->flags & SYMBOL_CHECK) {
1275 		sym_check_print_recursive(sym);
1276 		return sym;
1277 	}
1278 	if (sym->flags & SYMBOL_CHECKED)
1279 		return NULL;
1280 
1281 	choice = sym_get_choice_menu(sym);
1282 	if (choice) {
1283 		struct dep_stack stack;
1284 
1285 		/* for choice groups start the check with main choice symbol */
1286 		dep_stack_insert(&stack, sym);
1287 		sym2 = sym_check_deps(choice->sym);
1288 		dep_stack_remove();
1289 	} else if (sym_is_choice(sym)) {
1290 		sym2 = sym_check_choice_deps(sym);
1291 	} else {
1292 		sym->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1293 		sym2 = sym_check_sym_deps(sym);
1294 		sym->flags &= ~SYMBOL_CHECK;
1295 	}
1296 
1297 	return sym2;
1298 }
1299 
prop_get_symbol(const struct property * prop)1300 struct symbol *prop_get_symbol(const struct property *prop)
1301 {
1302 	if (prop->expr && prop->expr->type == E_SYMBOL)
1303 		return prop->expr->left.sym;
1304 	return NULL;
1305 }
1306 
prop_get_type_name(enum prop_type type)1307 const char *prop_get_type_name(enum prop_type type)
1308 {
1309 	switch (type) {
1310 	case P_PROMPT:
1311 		return "prompt";
1312 	case P_COMMENT:
1313 		return "comment";
1314 	case P_MENU:
1315 		return "menu";
1316 	case P_DEFAULT:
1317 		return "default";
1318 	case P_SELECT:
1319 		return "select";
1320 	case P_IMPLY:
1321 		return "imply";
1322 	case P_RANGE:
1323 		return "range";
1324 	case P_SYMBOL:
1325 		return "symbol";
1326 	case P_UNKNOWN:
1327 		break;
1328 	}
1329 	return "unknown";
1330 }
1331