xref: /linux/scripts/kconfig/menu.c (revision 37744feebc086908fd89760650f458ab19071750)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2002 Roman Zippel <zippel@linux-m68k.org>
4  */
5 
6 #include <ctype.h>
7 #include <stdarg.h>
8 #include <stdlib.h>
9 #include <string.h>
10 
11 #include "lkc.h"
12 
13 static const char nohelp_text[] = "There is no help available for this option.";
14 
15 struct menu rootmenu;
16 static struct menu **last_entry_ptr;
17 
18 struct file *file_list;
19 struct file *current_file;
20 
21 void menu_warn(struct menu *menu, const char *fmt, ...)
22 {
23 	va_list ap;
24 	va_start(ap, fmt);
25 	fprintf(stderr, "%s:%d:warning: ", menu->file->name, menu->lineno);
26 	vfprintf(stderr, fmt, ap);
27 	fprintf(stderr, "\n");
28 	va_end(ap);
29 }
30 
31 static void prop_warn(struct property *prop, const char *fmt, ...)
32 {
33 	va_list ap;
34 	va_start(ap, fmt);
35 	fprintf(stderr, "%s:%d:warning: ", prop->file->name, prop->lineno);
36 	vfprintf(stderr, fmt, ap);
37 	fprintf(stderr, "\n");
38 	va_end(ap);
39 }
40 
41 void _menu_init(void)
42 {
43 	current_entry = current_menu = &rootmenu;
44 	last_entry_ptr = &rootmenu.list;
45 }
46 
47 void menu_add_entry(struct symbol *sym)
48 {
49 	struct menu *menu;
50 
51 	menu = xmalloc(sizeof(*menu));
52 	memset(menu, 0, sizeof(*menu));
53 	menu->sym = sym;
54 	menu->parent = current_menu;
55 	menu->file = current_file;
56 	menu->lineno = zconf_lineno();
57 
58 	*last_entry_ptr = menu;
59 	last_entry_ptr = &menu->next;
60 	current_entry = menu;
61 	if (sym)
62 		menu_add_symbol(P_SYMBOL, sym, NULL);
63 }
64 
65 struct menu *menu_add_menu(void)
66 {
67 	last_entry_ptr = &current_entry->list;
68 	return current_menu = current_entry;
69 }
70 
71 void menu_end_menu(void)
72 {
73 	last_entry_ptr = &current_menu->next;
74 	current_menu = current_menu->parent;
75 }
76 
77 /*
78  * Rewrites 'm' to 'm' && MODULES, so that it evaluates to 'n' when running
79  * without modules
80  */
81 static struct expr *rewrite_m(struct expr *e)
82 {
83 	if (!e)
84 		return e;
85 
86 	switch (e->type) {
87 	case E_NOT:
88 		e->left.expr = rewrite_m(e->left.expr);
89 		break;
90 	case E_OR:
91 	case E_AND:
92 		e->left.expr = rewrite_m(e->left.expr);
93 		e->right.expr = rewrite_m(e->right.expr);
94 		break;
95 	case E_SYMBOL:
96 		/* change 'm' into 'm' && MODULES */
97 		if (e->left.sym == &symbol_mod)
98 			return expr_alloc_and(e, expr_alloc_symbol(modules_sym));
99 		break;
100 	default:
101 		break;
102 	}
103 	return e;
104 }
105 
106 void menu_add_dep(struct expr *dep)
107 {
108 	current_entry->dep = expr_alloc_and(current_entry->dep, dep);
109 }
110 
111 void menu_set_type(int type)
112 {
113 	struct symbol *sym = current_entry->sym;
114 
115 	if (sym->type == type)
116 		return;
117 	if (sym->type == S_UNKNOWN) {
118 		sym->type = type;
119 		return;
120 	}
121 	menu_warn(current_entry,
122 		"ignoring type redefinition of '%s' from '%s' to '%s'",
123 		sym->name ? sym->name : "<choice>",
124 		sym_type_name(sym->type), sym_type_name(type));
125 }
126 
127 static struct property *menu_add_prop(enum prop_type type, struct expr *expr,
128 				      struct expr *dep)
129 {
130 	struct property *prop;
131 
132 	prop = xmalloc(sizeof(*prop));
133 	memset(prop, 0, sizeof(*prop));
134 	prop->type = type;
135 	prop->file = current_file;
136 	prop->lineno = zconf_lineno();
137 	prop->menu = current_entry;
138 	prop->expr = expr;
139 	prop->visible.expr = dep;
140 
141 	/* append property to the prop list of symbol */
142 	if (current_entry->sym) {
143 		struct property **propp;
144 
145 		for (propp = &current_entry->sym->prop;
146 		     *propp;
147 		     propp = &(*propp)->next)
148 			;
149 		*propp = prop;
150 	}
151 
152 	return prop;
153 }
154 
155 struct property *menu_add_prompt(enum prop_type type, char *prompt,
156 				 struct expr *dep)
157 {
158 	struct property *prop = menu_add_prop(type, NULL, dep);
159 
160 	if (isspace(*prompt)) {
161 		prop_warn(prop, "leading whitespace ignored");
162 		while (isspace(*prompt))
163 			prompt++;
164 	}
165 	if (current_entry->prompt)
166 		prop_warn(prop, "prompt redefined");
167 
168 	/* Apply all upper menus' visibilities to actual prompts. */
169 	if (type == P_PROMPT) {
170 		struct menu *menu = current_entry;
171 
172 		while ((menu = menu->parent) != NULL) {
173 			struct expr *dup_expr;
174 
175 			if (!menu->visibility)
176 				continue;
177 			/*
178 			 * Do not add a reference to the menu's visibility
179 			 * expression but use a copy of it. Otherwise the
180 			 * expression reduction functions will modify
181 			 * expressions that have multiple references which
182 			 * can cause unwanted side effects.
183 			 */
184 			dup_expr = expr_copy(menu->visibility);
185 
186 			prop->visible.expr = expr_alloc_and(prop->visible.expr,
187 							    dup_expr);
188 		}
189 	}
190 
191 	current_entry->prompt = prop;
192 	prop->text = prompt;
193 
194 	return prop;
195 }
196 
197 void menu_add_visibility(struct expr *expr)
198 {
199 	current_entry->visibility = expr_alloc_and(current_entry->visibility,
200 	    expr);
201 }
202 
203 void menu_add_expr(enum prop_type type, struct expr *expr, struct expr *dep)
204 {
205 	menu_add_prop(type, expr, dep);
206 }
207 
208 void menu_add_symbol(enum prop_type type, struct symbol *sym, struct expr *dep)
209 {
210 	menu_add_prop(type, expr_alloc_symbol(sym), dep);
211 }
212 
213 void menu_add_option_modules(void)
214 {
215 	if (modules_sym)
216 		zconf_error("symbol '%s' redefines option 'modules' already defined by symbol '%s'",
217 			    current_entry->sym->name, modules_sym->name);
218 	modules_sym = current_entry->sym;
219 }
220 
221 void menu_add_option_defconfig_list(void)
222 {
223 	if (!sym_defconfig_list)
224 		sym_defconfig_list = current_entry->sym;
225 	else if (sym_defconfig_list != current_entry->sym)
226 		zconf_error("trying to redefine defconfig symbol");
227 	sym_defconfig_list->flags |= SYMBOL_NO_WRITE;
228 }
229 
230 void menu_add_option_allnoconfig_y(void)
231 {
232 	current_entry->sym->flags |= SYMBOL_ALLNOCONFIG_Y;
233 }
234 
235 static int menu_validate_number(struct symbol *sym, struct symbol *sym2)
236 {
237 	return sym2->type == S_INT || sym2->type == S_HEX ||
238 	       (sym2->type == S_UNKNOWN && sym_string_valid(sym, sym2->name));
239 }
240 
241 static void sym_check_prop(struct symbol *sym)
242 {
243 	struct property *prop;
244 	struct symbol *sym2;
245 	char *use;
246 
247 	for (prop = sym->prop; prop; prop = prop->next) {
248 		switch (prop->type) {
249 		case P_DEFAULT:
250 			if ((sym->type == S_STRING || sym->type == S_INT || sym->type == S_HEX) &&
251 			    prop->expr->type != E_SYMBOL)
252 				prop_warn(prop,
253 				    "default for config symbol '%s'"
254 				    " must be a single symbol", sym->name);
255 			if (prop->expr->type != E_SYMBOL)
256 				break;
257 			sym2 = prop_get_symbol(prop);
258 			if (sym->type == S_HEX || sym->type == S_INT) {
259 				if (!menu_validate_number(sym, sym2))
260 					prop_warn(prop,
261 					    "'%s': number is invalid",
262 					    sym->name);
263 			}
264 			if (sym_is_choice(sym)) {
265 				struct property *choice_prop =
266 					sym_get_choice_prop(sym2);
267 
268 				if (!choice_prop ||
269 				    prop_get_symbol(choice_prop) != sym)
270 					prop_warn(prop,
271 						  "choice default symbol '%s' is not contained in the choice",
272 						  sym2->name);
273 			}
274 			break;
275 		case P_SELECT:
276 		case P_IMPLY:
277 			use = prop->type == P_SELECT ? "select" : "imply";
278 			sym2 = prop_get_symbol(prop);
279 			if (sym->type != S_BOOLEAN && sym->type != S_TRISTATE)
280 				prop_warn(prop,
281 				    "config symbol '%s' uses %s, but is "
282 				    "not bool or tristate", sym->name, use);
283 			else if (sym2->type != S_UNKNOWN &&
284 				 sym2->type != S_BOOLEAN &&
285 				 sym2->type != S_TRISTATE)
286 				prop_warn(prop,
287 				    "'%s' has wrong type. '%s' only "
288 				    "accept arguments of bool and "
289 				    "tristate type", sym2->name, use);
290 			break;
291 		case P_RANGE:
292 			if (sym->type != S_INT && sym->type != S_HEX)
293 				prop_warn(prop, "range is only allowed "
294 						"for int or hex symbols");
295 			if (!menu_validate_number(sym, prop->expr->left.sym) ||
296 			    !menu_validate_number(sym, prop->expr->right.sym))
297 				prop_warn(prop, "range is invalid");
298 			break;
299 		default:
300 			;
301 		}
302 	}
303 }
304 
305 void menu_finalize(struct menu *parent)
306 {
307 	struct menu *menu, *last_menu;
308 	struct symbol *sym;
309 	struct property *prop;
310 	struct expr *parentdep, *basedep, *dep, *dep2, **ep;
311 
312 	sym = parent->sym;
313 	if (parent->list) {
314 		/*
315 		 * This menu node has children. We (recursively) process them
316 		 * and propagate parent dependencies before moving on.
317 		 */
318 
319 		if (sym && sym_is_choice(sym)) {
320 			if (sym->type == S_UNKNOWN) {
321 				/* find the first choice value to find out choice type */
322 				current_entry = parent;
323 				for (menu = parent->list; menu; menu = menu->next) {
324 					if (menu->sym && menu->sym->type != S_UNKNOWN) {
325 						menu_set_type(menu->sym->type);
326 						break;
327 					}
328 				}
329 			}
330 			/* set the type of the remaining choice values */
331 			for (menu = parent->list; menu; menu = menu->next) {
332 				current_entry = menu;
333 				if (menu->sym && menu->sym->type == S_UNKNOWN)
334 					menu_set_type(sym->type);
335 			}
336 
337 			/*
338 			 * Use the choice itself as the parent dependency of
339 			 * the contained items. This turns the mode of the
340 			 * choice into an upper bound on the visibility of the
341 			 * choice value symbols.
342 			 */
343 			parentdep = expr_alloc_symbol(sym);
344 		} else {
345 			/* Menu node for 'menu', 'if' */
346 			parentdep = parent->dep;
347 		}
348 
349 		/* For each child menu node... */
350 		for (menu = parent->list; menu; menu = menu->next) {
351 			/*
352 			 * Propagate parent dependencies to the child menu
353 			 * node, also rewriting and simplifying expressions
354 			 */
355 			basedep = rewrite_m(menu->dep);
356 			basedep = expr_transform(basedep);
357 			basedep = expr_alloc_and(expr_copy(parentdep), basedep);
358 			basedep = expr_eliminate_dups(basedep);
359 			menu->dep = basedep;
360 
361 			if (menu->sym)
362 				/*
363 				 * Note: For symbols, all prompts are included
364 				 * too in the symbol's own property list
365 				 */
366 				prop = menu->sym->prop;
367 			else
368 				/*
369 				 * For non-symbol menu nodes, we just need to
370 				 * handle the prompt
371 				 */
372 				prop = menu->prompt;
373 
374 			/* For each property... */
375 			for (; prop; prop = prop->next) {
376 				if (prop->menu != menu)
377 					/*
378 					 * Two possibilities:
379 					 *
380 					 * 1. The property lacks dependencies
381 					 *    and so isn't location-specific,
382 					 *    e.g. an 'option'
383 					 *
384 					 * 2. The property belongs to a symbol
385 					 *    defined in multiple locations and
386 					 *    is from some other location. It
387 					 *    will be handled there in that
388 					 *    case.
389 					 *
390 					 * Skip the property.
391 					 */
392 					continue;
393 
394 				/*
395 				 * Propagate parent dependencies to the
396 				 * property's condition, rewriting and
397 				 * simplifying expressions at the same time
398 				 */
399 				dep = rewrite_m(prop->visible.expr);
400 				dep = expr_transform(dep);
401 				dep = expr_alloc_and(expr_copy(basedep), dep);
402 				dep = expr_eliminate_dups(dep);
403 				if (menu->sym && menu->sym->type != S_TRISTATE)
404 					dep = expr_trans_bool(dep);
405 				prop->visible.expr = dep;
406 
407 				/*
408 				 * Handle selects and implies, which modify the
409 				 * dependencies of the selected/implied symbol
410 				 */
411 				if (prop->type == P_SELECT) {
412 					struct symbol *es = prop_get_symbol(prop);
413 					es->rev_dep.expr = expr_alloc_or(es->rev_dep.expr,
414 							expr_alloc_and(expr_alloc_symbol(menu->sym), expr_copy(dep)));
415 				} else if (prop->type == P_IMPLY) {
416 					struct symbol *es = prop_get_symbol(prop);
417 					es->implied.expr = expr_alloc_or(es->implied.expr,
418 							expr_alloc_and(expr_alloc_symbol(menu->sym), expr_copy(dep)));
419 				}
420 			}
421 		}
422 
423 		if (sym && sym_is_choice(sym))
424 			expr_free(parentdep);
425 
426 		/*
427 		 * Recursively process children in the same fashion before
428 		 * moving on
429 		 */
430 		for (menu = parent->list; menu; menu = menu->next)
431 			menu_finalize(menu);
432 	} else if (sym) {
433 		/*
434 		 * Automatic submenu creation. If sym is a symbol and A, B, C,
435 		 * ... are consecutive items (symbols, menus, ifs, etc.) that
436 		 * all depend on sym, then the following menu structure is
437 		 * created:
438 		 *
439 		 *	sym
440 		 *	 +-A
441 		 *	 +-B
442 		 *	 +-C
443 		 *	 ...
444 		 *
445 		 * This also works recursively, giving the following structure
446 		 * if A is a symbol and B depends on A:
447 		 *
448 		 *	sym
449 		 *	 +-A
450 		 *	 | +-B
451 		 *	 +-C
452 		 *	 ...
453 		 */
454 
455 		basedep = parent->prompt ? parent->prompt->visible.expr : NULL;
456 		basedep = expr_trans_compare(basedep, E_UNEQUAL, &symbol_no);
457 		basedep = expr_eliminate_dups(expr_transform(basedep));
458 
459 		/* Examine consecutive elements after sym */
460 		last_menu = NULL;
461 		for (menu = parent->next; menu; menu = menu->next) {
462 			dep = menu->prompt ? menu->prompt->visible.expr : menu->dep;
463 			if (!expr_contains_symbol(dep, sym))
464 				/* No dependency, quit */
465 				break;
466 			if (expr_depends_symbol(dep, sym))
467 				/* Absolute dependency, put in submenu */
468 				goto next;
469 
470 			/*
471 			 * Also consider it a dependency on sym if our
472 			 * dependencies contain sym and are a "superset" of
473 			 * sym's dependencies, e.g. '(sym || Q) && R' when sym
474 			 * depends on R.
475 			 *
476 			 * Note that 'R' might be from an enclosing menu or if,
477 			 * making this a more common case than it might seem.
478 			 */
479 			dep = expr_trans_compare(dep, E_UNEQUAL, &symbol_no);
480 			dep = expr_eliminate_dups(expr_transform(dep));
481 			dep2 = expr_copy(basedep);
482 			expr_eliminate_eq(&dep, &dep2);
483 			expr_free(dep);
484 			if (!expr_is_yes(dep2)) {
485 				/* Not superset, quit */
486 				expr_free(dep2);
487 				break;
488 			}
489 			/* Superset, put in submenu */
490 			expr_free(dep2);
491 		next:
492 			menu_finalize(menu);
493 			menu->parent = parent;
494 			last_menu = menu;
495 		}
496 		expr_free(basedep);
497 		if (last_menu) {
498 			parent->list = parent->next;
499 			parent->next = last_menu->next;
500 			last_menu->next = NULL;
501 		}
502 
503 		sym->dir_dep.expr = expr_alloc_or(sym->dir_dep.expr, parent->dep);
504 	}
505 	for (menu = parent->list; menu; menu = menu->next) {
506 		if (sym && sym_is_choice(sym) &&
507 		    menu->sym && !sym_is_choice_value(menu->sym)) {
508 			current_entry = menu;
509 			menu->sym->flags |= SYMBOL_CHOICEVAL;
510 			if (!menu->prompt)
511 				menu_warn(menu, "choice value must have a prompt");
512 			for (prop = menu->sym->prop; prop; prop = prop->next) {
513 				if (prop->type == P_DEFAULT)
514 					prop_warn(prop, "defaults for choice "
515 						  "values not supported");
516 				if (prop->menu == menu)
517 					continue;
518 				if (prop->type == P_PROMPT &&
519 				    prop->menu->parent->sym != sym)
520 					prop_warn(prop, "choice value used outside its choice group");
521 			}
522 			/* Non-tristate choice values of tristate choices must
523 			 * depend on the choice being set to Y. The choice
524 			 * values' dependencies were propagated to their
525 			 * properties above, so the change here must be re-
526 			 * propagated.
527 			 */
528 			if (sym->type == S_TRISTATE && menu->sym->type != S_TRISTATE) {
529 				basedep = expr_alloc_comp(E_EQUAL, sym, &symbol_yes);
530 				menu->dep = expr_alloc_and(basedep, menu->dep);
531 				for (prop = menu->sym->prop; prop; prop = prop->next) {
532 					if (prop->menu != menu)
533 						continue;
534 					prop->visible.expr = expr_alloc_and(expr_copy(basedep),
535 									    prop->visible.expr);
536 				}
537 			}
538 			menu_add_symbol(P_CHOICE, sym, NULL);
539 			prop = sym_get_choice_prop(sym);
540 			for (ep = &prop->expr; *ep; ep = &(*ep)->left.expr)
541 				;
542 			*ep = expr_alloc_one(E_LIST, NULL);
543 			(*ep)->right.sym = menu->sym;
544 		}
545 
546 		/*
547 		 * This code serves two purposes:
548 		 *
549 		 * (1) Flattening 'if' blocks, which do not specify a submenu
550 		 *     and only add dependencies.
551 		 *
552 		 *     (Automatic submenu creation might still create a submenu
553 		 *     from an 'if' before this code runs.)
554 		 *
555 		 * (2) "Undoing" any automatic submenus created earlier below
556 		 *     promptless symbols.
557 		 *
558 		 * Before:
559 		 *
560 		 *	A
561 		 *	if ... (or promptless symbol)
562 		 *	 +-B
563 		 *	 +-C
564 		 *	D
565 		 *
566 		 * After:
567 		 *
568 		 *	A
569 		 *	if ... (or promptless symbol)
570 		 *	B
571 		 *	C
572 		 *	D
573 		 */
574 		if (menu->list && (!menu->prompt || !menu->prompt->text)) {
575 			for (last_menu = menu->list; ; last_menu = last_menu->next) {
576 				last_menu->parent = parent;
577 				if (!last_menu->next)
578 					break;
579 			}
580 			last_menu->next = menu->next;
581 			menu->next = menu->list;
582 			menu->list = NULL;
583 		}
584 	}
585 
586 	if (sym && !(sym->flags & SYMBOL_WARNED)) {
587 		if (sym->type == S_UNKNOWN)
588 			menu_warn(parent, "config symbol defined without type");
589 
590 		if (sym_is_choice(sym) && !parent->prompt)
591 			menu_warn(parent, "choice must have a prompt");
592 
593 		/* Check properties connected to this symbol */
594 		sym_check_prop(sym);
595 		sym->flags |= SYMBOL_WARNED;
596 	}
597 
598 	/*
599 	 * For non-optional choices, add a reverse dependency (corresponding to
600 	 * a select) of '<visibility> && m'. This prevents the user from
601 	 * setting the choice mode to 'n' when the choice is visible.
602 	 *
603 	 * This would also work for non-choice symbols, but only non-optional
604 	 * choices clear SYMBOL_OPTIONAL as of writing. Choices are implemented
605 	 * as a type of symbol.
606 	 */
607 	if (sym && !sym_is_optional(sym) && parent->prompt) {
608 		sym->rev_dep.expr = expr_alloc_or(sym->rev_dep.expr,
609 				expr_alloc_and(parent->prompt->visible.expr,
610 					expr_alloc_symbol(&symbol_mod)));
611 	}
612 }
613 
614 bool menu_has_prompt(struct menu *menu)
615 {
616 	if (!menu->prompt)
617 		return false;
618 	return true;
619 }
620 
621 /*
622  * Determine if a menu is empty.
623  * A menu is considered empty if it contains no or only
624  * invisible entries.
625  */
626 bool menu_is_empty(struct menu *menu)
627 {
628 	struct menu *child;
629 
630 	for (child = menu->list; child; child = child->next) {
631 		if (menu_is_visible(child))
632 			return(false);
633 	}
634 	return(true);
635 }
636 
637 bool menu_is_visible(struct menu *menu)
638 {
639 	struct menu *child;
640 	struct symbol *sym;
641 	tristate visible;
642 
643 	if (!menu->prompt)
644 		return false;
645 
646 	if (menu->visibility) {
647 		if (expr_calc_value(menu->visibility) == no)
648 			return false;
649 	}
650 
651 	sym = menu->sym;
652 	if (sym) {
653 		sym_calc_value(sym);
654 		visible = menu->prompt->visible.tri;
655 	} else
656 		visible = menu->prompt->visible.tri = expr_calc_value(menu->prompt->visible.expr);
657 
658 	if (visible != no)
659 		return true;
660 
661 	if (!sym || sym_get_tristate_value(menu->sym) == no)
662 		return false;
663 
664 	for (child = menu->list; child; child = child->next) {
665 		if (menu_is_visible(child)) {
666 			if (sym)
667 				sym->flags |= SYMBOL_DEF_USER;
668 			return true;
669 		}
670 	}
671 
672 	return false;
673 }
674 
675 const char *menu_get_prompt(struct menu *menu)
676 {
677 	if (menu->prompt)
678 		return menu->prompt->text;
679 	else if (menu->sym)
680 		return menu->sym->name;
681 	return NULL;
682 }
683 
684 struct menu *menu_get_root_menu(struct menu *menu)
685 {
686 	return &rootmenu;
687 }
688 
689 struct menu *menu_get_parent_menu(struct menu *menu)
690 {
691 	enum prop_type type;
692 
693 	for (; menu != &rootmenu; menu = menu->parent) {
694 		type = menu->prompt ? menu->prompt->type : 0;
695 		if (type == P_MENU)
696 			break;
697 	}
698 	return menu;
699 }
700 
701 bool menu_has_help(struct menu *menu)
702 {
703 	return menu->help != NULL;
704 }
705 
706 const char *menu_get_help(struct menu *menu)
707 {
708 	if (menu->help)
709 		return menu->help;
710 	else
711 		return "";
712 }
713 
714 static void get_def_str(struct gstr *r, struct menu *menu)
715 {
716 	str_printf(r, "Defined at %s:%d\n",
717 		   menu->file->name, menu->lineno);
718 }
719 
720 static void get_dep_str(struct gstr *r, struct expr *expr, const char *prefix)
721 {
722 	if (!expr_is_yes(expr)) {
723 		str_append(r, prefix);
724 		expr_gstr_print(expr, r);
725 		str_append(r, "\n");
726 	}
727 }
728 
729 static void get_prompt_str(struct gstr *r, struct property *prop,
730 			   struct list_head *head)
731 {
732 	int i, j;
733 	struct menu *submenu[8], *menu, *location = NULL;
734 	struct jump_key *jump = NULL;
735 
736 	str_printf(r, "  Prompt: %s\n", prop->text);
737 
738 	get_dep_str(r, prop->menu->dep, "  Depends on: ");
739 	/*
740 	 * Most prompts in Linux have visibility that exactly matches their
741 	 * dependencies. For these, we print only the dependencies to improve
742 	 * readability. However, prompts with inline "if" expressions and
743 	 * prompts with a parent that has a "visible if" expression have
744 	 * differing dependencies and visibility. In these rare cases, we
745 	 * print both.
746 	 */
747 	if (!expr_eq(prop->menu->dep, prop->visible.expr))
748 		get_dep_str(r, prop->visible.expr, "  Visible if: ");
749 
750 	menu = prop->menu->parent;
751 	for (i = 0; menu != &rootmenu && i < 8; menu = menu->parent) {
752 		bool accessible = menu_is_visible(menu);
753 
754 		submenu[i++] = menu;
755 		if (location == NULL && accessible)
756 			location = menu;
757 	}
758 	if (head && location) {
759 		jump = xmalloc(sizeof(struct jump_key));
760 
761 		if (menu_is_visible(prop->menu)) {
762 			/*
763 			 * There is not enough room to put the hint at the
764 			 * beginning of the "Prompt" line. Put the hint on the
765 			 * last "Location" line even when it would belong on
766 			 * the former.
767 			 */
768 			jump->target = prop->menu;
769 		} else
770 			jump->target = location;
771 
772 		if (list_empty(head))
773 			jump->index = 0;
774 		else
775 			jump->index = list_entry(head->prev, struct jump_key,
776 						 entries)->index + 1;
777 
778 		list_add_tail(&jump->entries, head);
779 	}
780 
781 	if (i > 0) {
782 		str_printf(r, "  Location:\n");
783 		for (j = 4; --i >= 0; j += 2) {
784 			menu = submenu[i];
785 			if (jump && menu == location)
786 				jump->offset = strlen(r->s);
787 			str_printf(r, "%*c-> %s", j, ' ',
788 				   menu_get_prompt(menu));
789 			if (menu->sym) {
790 				str_printf(r, " (%s [=%s])", menu->sym->name ?
791 					menu->sym->name : "<choice>",
792 					sym_get_string_value(menu->sym));
793 			}
794 			str_append(r, "\n");
795 		}
796 	}
797 }
798 
799 static void get_symbol_props_str(struct gstr *r, struct symbol *sym,
800 				 enum prop_type tok, const char *prefix)
801 {
802 	bool hit = false;
803 	struct property *prop;
804 
805 	for_all_properties(sym, prop, tok) {
806 		if (!hit) {
807 			str_append(r, prefix);
808 			hit = true;
809 		} else
810 			str_printf(r, " && ");
811 		expr_gstr_print(prop->expr, r);
812 	}
813 	if (hit)
814 		str_append(r, "\n");
815 }
816 
817 /*
818  * head is optional and may be NULL
819  */
820 static void get_symbol_str(struct gstr *r, struct symbol *sym,
821 		    struct list_head *head)
822 {
823 	struct property *prop;
824 
825 	if (sym && sym->name) {
826 		str_printf(r, "Symbol: %s [=%s]\n", sym->name,
827 			   sym_get_string_value(sym));
828 		str_printf(r, "Type  : %s\n", sym_type_name(sym->type));
829 		if (sym->type == S_INT || sym->type == S_HEX) {
830 			prop = sym_get_range_prop(sym);
831 			if (prop) {
832 				str_printf(r, "Range : ");
833 				expr_gstr_print(prop->expr, r);
834 				str_append(r, "\n");
835 			}
836 		}
837 	}
838 
839 	/* Print the definitions with prompts before the ones without */
840 	for_all_properties(sym, prop, P_SYMBOL) {
841 		if (prop->menu->prompt) {
842 			get_def_str(r, prop->menu);
843 			get_prompt_str(r, prop->menu->prompt, head);
844 		}
845 	}
846 
847 	for_all_properties(sym, prop, P_SYMBOL) {
848 		if (!prop->menu->prompt) {
849 			get_def_str(r, prop->menu);
850 			get_dep_str(r, prop->menu->dep, "  Depends on: ");
851 		}
852 	}
853 
854 	get_symbol_props_str(r, sym, P_SELECT, "Selects: ");
855 	if (sym->rev_dep.expr) {
856 		expr_gstr_print_revdep(sym->rev_dep.expr, r, yes, "Selected by [y]:\n");
857 		expr_gstr_print_revdep(sym->rev_dep.expr, r, mod, "Selected by [m]:\n");
858 		expr_gstr_print_revdep(sym->rev_dep.expr, r, no, "Selected by [n]:\n");
859 	}
860 
861 	get_symbol_props_str(r, sym, P_IMPLY, "Implies: ");
862 	if (sym->implied.expr) {
863 		expr_gstr_print_revdep(sym->implied.expr, r, yes, "Implied by [y]:\n");
864 		expr_gstr_print_revdep(sym->implied.expr, r, mod, "Implied by [m]:\n");
865 		expr_gstr_print_revdep(sym->implied.expr, r, no, "Implied by [n]:\n");
866 	}
867 
868 	str_append(r, "\n\n");
869 }
870 
871 struct gstr get_relations_str(struct symbol **sym_arr, struct list_head *head)
872 {
873 	struct symbol *sym;
874 	struct gstr res = str_new();
875 	int i;
876 
877 	for (i = 0; sym_arr && (sym = sym_arr[i]); i++)
878 		get_symbol_str(&res, sym, head);
879 	if (!i)
880 		str_append(&res, "No matches found.\n");
881 	return res;
882 }
883 
884 
885 void menu_get_ext_help(struct menu *menu, struct gstr *help)
886 {
887 	struct symbol *sym = menu->sym;
888 	const char *help_text = nohelp_text;
889 
890 	if (menu_has_help(menu)) {
891 		if (sym->name)
892 			str_printf(help, "%s%s:\n\n", CONFIG_, sym->name);
893 		help_text = menu_get_help(menu);
894 	}
895 	str_printf(help, "%s\n", help_text);
896 	if (sym)
897 		get_symbol_str(help, sym, NULL);
898 }
899