xref: /openbmc/linux/scripts/kconfig/menu.c (revision 2d99a7ec)
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 #include "internal.h"
13 
14 static const char nohelp_text[] = "There is no help available for this option.";
15 
16 struct menu rootmenu;
17 static struct menu **last_entry_ptr;
18 
19 struct file *file_list;
20 struct file *current_file;
21 
22 void menu_warn(struct menu *menu, const char *fmt, ...)
23 {
24 	va_list ap;
25 	va_start(ap, fmt);
26 	fprintf(stderr, "%s:%d:warning: ", menu->file->name, menu->lineno);
27 	vfprintf(stderr, fmt, ap);
28 	fprintf(stderr, "\n");
29 	va_end(ap);
30 }
31 
32 static void prop_warn(struct property *prop, const char *fmt, ...)
33 {
34 	va_list ap;
35 	va_start(ap, fmt);
36 	fprintf(stderr, "%s:%d:warning: ", prop->file->name, prop->lineno);
37 	vfprintf(stderr, fmt, ap);
38 	fprintf(stderr, "\n");
39 	va_end(ap);
40 }
41 
42 void _menu_init(void)
43 {
44 	current_entry = current_menu = &rootmenu;
45 	last_entry_ptr = &rootmenu.list;
46 }
47 
48 void menu_add_entry(struct symbol *sym)
49 {
50 	struct menu *menu;
51 
52 	menu = xmalloc(sizeof(*menu));
53 	memset(menu, 0, sizeof(*menu));
54 	menu->sym = sym;
55 	menu->parent = current_menu;
56 	menu->file = current_file;
57 	menu->lineno = zconf_lineno();
58 
59 	*last_entry_ptr = menu;
60 	last_entry_ptr = &menu->next;
61 	current_entry = menu;
62 	if (sym)
63 		menu_add_symbol(P_SYMBOL, sym, NULL);
64 }
65 
66 struct menu *menu_add_menu(void)
67 {
68 	last_entry_ptr = &current_entry->list;
69 	current_menu = current_entry;
70 	return current_menu;
71 }
72 
73 void menu_end_menu(void)
74 {
75 	last_entry_ptr = &current_menu->next;
76 	current_menu = current_menu->parent;
77 }
78 
79 /*
80  * Rewrites 'm' to 'm' && MODULES, so that it evaluates to 'n' when running
81  * without modules
82  */
83 static struct expr *rewrite_m(struct expr *e)
84 {
85 	if (!e)
86 		return e;
87 
88 	switch (e->type) {
89 	case E_NOT:
90 		e->left.expr = rewrite_m(e->left.expr);
91 		break;
92 	case E_OR:
93 	case E_AND:
94 		e->left.expr = rewrite_m(e->left.expr);
95 		e->right.expr = rewrite_m(e->right.expr);
96 		break;
97 	case E_SYMBOL:
98 		/* change 'm' into 'm' && MODULES */
99 		if (e->left.sym == &symbol_mod)
100 			return expr_alloc_and(e, expr_alloc_symbol(modules_sym));
101 		break;
102 	default:
103 		break;
104 	}
105 	return e;
106 }
107 
108 void menu_add_dep(struct expr *dep)
109 {
110 	current_entry->dep = expr_alloc_and(current_entry->dep, dep);
111 }
112 
113 void menu_set_type(int type)
114 {
115 	struct symbol *sym = current_entry->sym;
116 
117 	if (sym->type == type)
118 		return;
119 	if (sym->type == S_UNKNOWN) {
120 		sym->type = type;
121 		return;
122 	}
123 	menu_warn(current_entry,
124 		"ignoring type redefinition of '%s' from '%s' to '%s'",
125 		sym->name ? sym->name : "<choice>",
126 		sym_type_name(sym->type), sym_type_name(type));
127 }
128 
129 static struct property *menu_add_prop(enum prop_type type, struct expr *expr,
130 				      struct expr *dep)
131 {
132 	struct property *prop;
133 
134 	prop = xmalloc(sizeof(*prop));
135 	memset(prop, 0, sizeof(*prop));
136 	prop->type = type;
137 	prop->file = current_file;
138 	prop->lineno = zconf_lineno();
139 	prop->menu = current_entry;
140 	prop->expr = expr;
141 	prop->visible.expr = dep;
142 
143 	/* append property to the prop list of symbol */
144 	if (current_entry->sym) {
145 		struct property **propp;
146 
147 		for (propp = &current_entry->sym->prop;
148 		     *propp;
149 		     propp = &(*propp)->next)
150 			;
151 		*propp = prop;
152 	}
153 
154 	return prop;
155 }
156 
157 struct property *menu_add_prompt(enum prop_type type, char *prompt,
158 				 struct expr *dep)
159 {
160 	struct property *prop = menu_add_prop(type, NULL, dep);
161 
162 	if (isspace(*prompt)) {
163 		prop_warn(prop, "leading whitespace ignored");
164 		while (isspace(*prompt))
165 			prompt++;
166 	}
167 	if (current_entry->prompt)
168 		prop_warn(prop, "prompt redefined");
169 
170 	/* Apply all upper menus' visibilities to actual prompts. */
171 	if (type == P_PROMPT) {
172 		struct menu *menu = current_entry;
173 
174 		while ((menu = menu->parent) != NULL) {
175 			struct expr *dup_expr;
176 
177 			if (!menu->visibility)
178 				continue;
179 			/*
180 			 * Do not add a reference to the menu's visibility
181 			 * expression but use a copy of it. Otherwise the
182 			 * expression reduction functions will modify
183 			 * expressions that have multiple references which
184 			 * can cause unwanted side effects.
185 			 */
186 			dup_expr = expr_copy(menu->visibility);
187 
188 			prop->visible.expr = expr_alloc_and(prop->visible.expr,
189 							    dup_expr);
190 		}
191 	}
192 
193 	current_entry->prompt = prop;
194 	prop->text = prompt;
195 
196 	return prop;
197 }
198 
199 void menu_add_visibility(struct expr *expr)
200 {
201 	current_entry->visibility = expr_alloc_and(current_entry->visibility,
202 	    expr);
203 }
204 
205 void menu_add_expr(enum prop_type type, struct expr *expr, struct expr *dep)
206 {
207 	menu_add_prop(type, expr, dep);
208 }
209 
210 void menu_add_symbol(enum prop_type type, struct symbol *sym, struct expr *dep)
211 {
212 	menu_add_prop(type, expr_alloc_symbol(sym), dep);
213 }
214 
215 static int menu_validate_number(struct symbol *sym, struct symbol *sym2)
216 {
217 	return sym2->type == S_INT || sym2->type == S_HEX ||
218 	       (sym2->type == S_UNKNOWN && sym_string_valid(sym, sym2->name));
219 }
220 
221 static void sym_check_prop(struct symbol *sym)
222 {
223 	struct property *prop;
224 	struct symbol *sym2;
225 	char *use;
226 
227 	for (prop = sym->prop; prop; prop = prop->next) {
228 		switch (prop->type) {
229 		case P_DEFAULT:
230 			if ((sym->type == S_STRING || sym->type == S_INT || sym->type == S_HEX) &&
231 			    prop->expr->type != E_SYMBOL)
232 				prop_warn(prop,
233 				    "default for config symbol '%s'"
234 				    " must be a single symbol", sym->name);
235 			if (prop->expr->type != E_SYMBOL)
236 				break;
237 			sym2 = prop_get_symbol(prop);
238 			if (sym->type == S_HEX || sym->type == S_INT) {
239 				if (!menu_validate_number(sym, sym2))
240 					prop_warn(prop,
241 					    "'%s': number is invalid",
242 					    sym->name);
243 			}
244 			if (sym_is_choice(sym)) {
245 				struct property *choice_prop =
246 					sym_get_choice_prop(sym2);
247 
248 				if (!choice_prop ||
249 				    prop_get_symbol(choice_prop) != sym)
250 					prop_warn(prop,
251 						  "choice default symbol '%s' is not contained in the choice",
252 						  sym2->name);
253 			}
254 			break;
255 		case P_SELECT:
256 		case P_IMPLY:
257 			use = prop->type == P_SELECT ? "select" : "imply";
258 			sym2 = prop_get_symbol(prop);
259 			if (sym->type != S_BOOLEAN && sym->type != S_TRISTATE)
260 				prop_warn(prop,
261 				    "config symbol '%s' uses %s, but is "
262 				    "not bool or tristate", sym->name, use);
263 			else if (sym2->type != S_UNKNOWN &&
264 				 sym2->type != S_BOOLEAN &&
265 				 sym2->type != S_TRISTATE)
266 				prop_warn(prop,
267 				    "'%s' has wrong type. '%s' only "
268 				    "accept arguments of bool and "
269 				    "tristate type", sym2->name, use);
270 			break;
271 		case P_RANGE:
272 			if (sym->type != S_INT && sym->type != S_HEX)
273 				prop_warn(prop, "range is only allowed "
274 						"for int or hex symbols");
275 			if (!menu_validate_number(sym, prop->expr->left.sym) ||
276 			    !menu_validate_number(sym, prop->expr->right.sym))
277 				prop_warn(prop, "range is invalid");
278 			break;
279 		default:
280 			;
281 		}
282 	}
283 }
284 
285 void menu_finalize(struct menu *parent)
286 {
287 	struct menu *menu, *last_menu;
288 	struct symbol *sym;
289 	struct property *prop;
290 	struct expr *parentdep, *basedep, *dep, *dep2, **ep;
291 
292 	sym = parent->sym;
293 	if (parent->list) {
294 		/*
295 		 * This menu node has children. We (recursively) process them
296 		 * and propagate parent dependencies before moving on.
297 		 */
298 
299 		if (sym && sym_is_choice(sym)) {
300 			if (sym->type == S_UNKNOWN) {
301 				/* find the first choice value to find out choice type */
302 				current_entry = parent;
303 				for (menu = parent->list; menu; menu = menu->next) {
304 					if (menu->sym && menu->sym->type != S_UNKNOWN) {
305 						menu_set_type(menu->sym->type);
306 						break;
307 					}
308 				}
309 			}
310 			/* set the type of the remaining choice values */
311 			for (menu = parent->list; menu; menu = menu->next) {
312 				current_entry = menu;
313 				if (menu->sym && menu->sym->type == S_UNKNOWN)
314 					menu_set_type(sym->type);
315 			}
316 
317 			/*
318 			 * Use the choice itself as the parent dependency of
319 			 * the contained items. This turns the mode of the
320 			 * choice into an upper bound on the visibility of the
321 			 * choice value symbols.
322 			 */
323 			parentdep = expr_alloc_symbol(sym);
324 		} else {
325 			/* Menu node for 'menu', 'if' */
326 			parentdep = parent->dep;
327 		}
328 
329 		/* For each child menu node... */
330 		for (menu = parent->list; menu; menu = menu->next) {
331 			/*
332 			 * Propagate parent dependencies to the child menu
333 			 * node, also rewriting and simplifying expressions
334 			 */
335 			basedep = rewrite_m(menu->dep);
336 			basedep = expr_transform(basedep);
337 			basedep = expr_alloc_and(expr_copy(parentdep), basedep);
338 			basedep = expr_eliminate_dups(basedep);
339 			menu->dep = basedep;
340 
341 			if (menu->sym)
342 				/*
343 				 * Note: For symbols, all prompts are included
344 				 * too in the symbol's own property list
345 				 */
346 				prop = menu->sym->prop;
347 			else
348 				/*
349 				 * For non-symbol menu nodes, we just need to
350 				 * handle the prompt
351 				 */
352 				prop = menu->prompt;
353 
354 			/* For each property... */
355 			for (; prop; prop = prop->next) {
356 				if (prop->menu != menu)
357 					/*
358 					 * Two possibilities:
359 					 *
360 					 * 1. The property lacks dependencies
361 					 *    and so isn't location-specific,
362 					 *    e.g. an 'option'
363 					 *
364 					 * 2. The property belongs to a symbol
365 					 *    defined in multiple locations and
366 					 *    is from some other location. It
367 					 *    will be handled there in that
368 					 *    case.
369 					 *
370 					 * Skip the property.
371 					 */
372 					continue;
373 
374 				/*
375 				 * Propagate parent dependencies to the
376 				 * property's condition, rewriting and
377 				 * simplifying expressions at the same time
378 				 */
379 				dep = rewrite_m(prop->visible.expr);
380 				dep = expr_transform(dep);
381 				dep = expr_alloc_and(expr_copy(basedep), dep);
382 				dep = expr_eliminate_dups(dep);
383 				if (menu->sym && menu->sym->type != S_TRISTATE)
384 					dep = expr_trans_bool(dep);
385 				prop->visible.expr = dep;
386 
387 				/*
388 				 * Handle selects and implies, which modify the
389 				 * dependencies of the selected/implied symbol
390 				 */
391 				if (prop->type == P_SELECT) {
392 					struct symbol *es = prop_get_symbol(prop);
393 					es->rev_dep.expr = expr_alloc_or(es->rev_dep.expr,
394 							expr_alloc_and(expr_alloc_symbol(menu->sym), expr_copy(dep)));
395 				} else if (prop->type == P_IMPLY) {
396 					struct symbol *es = prop_get_symbol(prop);
397 					es->implied.expr = expr_alloc_or(es->implied.expr,
398 							expr_alloc_and(expr_alloc_symbol(menu->sym), expr_copy(dep)));
399 				}
400 			}
401 		}
402 
403 		if (sym && sym_is_choice(sym))
404 			expr_free(parentdep);
405 
406 		/*
407 		 * Recursively process children in the same fashion before
408 		 * moving on
409 		 */
410 		for (menu = parent->list; menu; menu = menu->next)
411 			menu_finalize(menu);
412 	} else if (sym) {
413 		/*
414 		 * Automatic submenu creation. If sym is a symbol and A, B, C,
415 		 * ... are consecutive items (symbols, menus, ifs, etc.) that
416 		 * all depend on sym, then the following menu structure is
417 		 * created:
418 		 *
419 		 *	sym
420 		 *	 +-A
421 		 *	 +-B
422 		 *	 +-C
423 		 *	 ...
424 		 *
425 		 * This also works recursively, giving the following structure
426 		 * if A is a symbol and B depends on A:
427 		 *
428 		 *	sym
429 		 *	 +-A
430 		 *	 | +-B
431 		 *	 +-C
432 		 *	 ...
433 		 */
434 
435 		basedep = parent->prompt ? parent->prompt->visible.expr : NULL;
436 		basedep = expr_trans_compare(basedep, E_UNEQUAL, &symbol_no);
437 		basedep = expr_eliminate_dups(expr_transform(basedep));
438 
439 		/* Examine consecutive elements after sym */
440 		last_menu = NULL;
441 		for (menu = parent->next; menu; menu = menu->next) {
442 			dep = menu->prompt ? menu->prompt->visible.expr : menu->dep;
443 			if (!expr_contains_symbol(dep, sym))
444 				/* No dependency, quit */
445 				break;
446 			if (expr_depends_symbol(dep, sym))
447 				/* Absolute dependency, put in submenu */
448 				goto next;
449 
450 			/*
451 			 * Also consider it a dependency on sym if our
452 			 * dependencies contain sym and are a "superset" of
453 			 * sym's dependencies, e.g. '(sym || Q) && R' when sym
454 			 * depends on R.
455 			 *
456 			 * Note that 'R' might be from an enclosing menu or if,
457 			 * making this a more common case than it might seem.
458 			 */
459 			dep = expr_trans_compare(dep, E_UNEQUAL, &symbol_no);
460 			dep = expr_eliminate_dups(expr_transform(dep));
461 			dep2 = expr_copy(basedep);
462 			expr_eliminate_eq(&dep, &dep2);
463 			expr_free(dep);
464 			if (!expr_is_yes(dep2)) {
465 				/* Not superset, quit */
466 				expr_free(dep2);
467 				break;
468 			}
469 			/* Superset, put in submenu */
470 			expr_free(dep2);
471 		next:
472 			menu_finalize(menu);
473 			menu->parent = parent;
474 			last_menu = menu;
475 		}
476 		expr_free(basedep);
477 		if (last_menu) {
478 			parent->list = parent->next;
479 			parent->next = last_menu->next;
480 			last_menu->next = NULL;
481 		}
482 
483 		sym->dir_dep.expr = expr_alloc_or(sym->dir_dep.expr, parent->dep);
484 	}
485 	for (menu = parent->list; menu; menu = menu->next) {
486 		if (sym && sym_is_choice(sym) &&
487 		    menu->sym && !sym_is_choice_value(menu->sym)) {
488 			current_entry = menu;
489 			menu->sym->flags |= SYMBOL_CHOICEVAL;
490 			if (!menu->prompt)
491 				menu_warn(menu, "choice value must have a prompt");
492 			for (prop = menu->sym->prop; prop; prop = prop->next) {
493 				if (prop->type == P_DEFAULT)
494 					prop_warn(prop, "defaults for choice "
495 						  "values not supported");
496 				if (prop->menu == menu)
497 					continue;
498 				if (prop->type == P_PROMPT &&
499 				    prop->menu->parent->sym != sym)
500 					prop_warn(prop, "choice value used outside its choice group");
501 			}
502 			/* Non-tristate choice values of tristate choices must
503 			 * depend on the choice being set to Y. The choice
504 			 * values' dependencies were propagated to their
505 			 * properties above, so the change here must be re-
506 			 * propagated.
507 			 */
508 			if (sym->type == S_TRISTATE && menu->sym->type != S_TRISTATE) {
509 				basedep = expr_alloc_comp(E_EQUAL, sym, &symbol_yes);
510 				menu->dep = expr_alloc_and(basedep, menu->dep);
511 				for (prop = menu->sym->prop; prop; prop = prop->next) {
512 					if (prop->menu != menu)
513 						continue;
514 					prop->visible.expr = expr_alloc_and(expr_copy(basedep),
515 									    prop->visible.expr);
516 				}
517 			}
518 			menu_add_symbol(P_CHOICE, sym, NULL);
519 			prop = sym_get_choice_prop(sym);
520 			for (ep = &prop->expr; *ep; ep = &(*ep)->left.expr)
521 				;
522 			*ep = expr_alloc_one(E_LIST, NULL);
523 			(*ep)->right.sym = menu->sym;
524 		}
525 
526 		/*
527 		 * This code serves two purposes:
528 		 *
529 		 * (1) Flattening 'if' blocks, which do not specify a submenu
530 		 *     and only add dependencies.
531 		 *
532 		 *     (Automatic submenu creation might still create a submenu
533 		 *     from an 'if' before this code runs.)
534 		 *
535 		 * (2) "Undoing" any automatic submenus created earlier below
536 		 *     promptless symbols.
537 		 *
538 		 * Before:
539 		 *
540 		 *	A
541 		 *	if ... (or promptless symbol)
542 		 *	 +-B
543 		 *	 +-C
544 		 *	D
545 		 *
546 		 * After:
547 		 *
548 		 *	A
549 		 *	if ... (or promptless symbol)
550 		 *	B
551 		 *	C
552 		 *	D
553 		 */
554 		if (menu->list && (!menu->prompt || !menu->prompt->text)) {
555 			for (last_menu = menu->list; ; last_menu = last_menu->next) {
556 				last_menu->parent = parent;
557 				if (!last_menu->next)
558 					break;
559 			}
560 			last_menu->next = menu->next;
561 			menu->next = menu->list;
562 			menu->list = NULL;
563 		}
564 	}
565 
566 	if (sym && !(sym->flags & SYMBOL_WARNED)) {
567 		if (sym->type == S_UNKNOWN)
568 			menu_warn(parent, "config symbol defined without type");
569 
570 		if (sym_is_choice(sym) && !parent->prompt)
571 			menu_warn(parent, "choice must have a prompt");
572 
573 		/* Check properties connected to this symbol */
574 		sym_check_prop(sym);
575 		sym->flags |= SYMBOL_WARNED;
576 	}
577 
578 	/*
579 	 * For non-optional choices, add a reverse dependency (corresponding to
580 	 * a select) of '<visibility> && m'. This prevents the user from
581 	 * setting the choice mode to 'n' when the choice is visible.
582 	 *
583 	 * This would also work for non-choice symbols, but only non-optional
584 	 * choices clear SYMBOL_OPTIONAL as of writing. Choices are implemented
585 	 * as a type of symbol.
586 	 */
587 	if (sym && !sym_is_optional(sym) && parent->prompt) {
588 		sym->rev_dep.expr = expr_alloc_or(sym->rev_dep.expr,
589 				expr_alloc_and(parent->prompt->visible.expr,
590 					expr_alloc_symbol(&symbol_mod)));
591 	}
592 }
593 
594 bool menu_has_prompt(struct menu *menu)
595 {
596 	if (!menu->prompt)
597 		return false;
598 	return true;
599 }
600 
601 /*
602  * Determine if a menu is empty.
603  * A menu is considered empty if it contains no or only
604  * invisible entries.
605  */
606 bool menu_is_empty(struct menu *menu)
607 {
608 	struct menu *child;
609 
610 	for (child = menu->list; child; child = child->next) {
611 		if (menu_is_visible(child))
612 			return(false);
613 	}
614 	return(true);
615 }
616 
617 bool menu_is_visible(struct menu *menu)
618 {
619 	struct menu *child;
620 	struct symbol *sym;
621 	tristate visible;
622 
623 	if (!menu->prompt)
624 		return false;
625 
626 	if (menu->visibility) {
627 		if (expr_calc_value(menu->visibility) == no)
628 			return false;
629 	}
630 
631 	sym = menu->sym;
632 	if (sym) {
633 		sym_calc_value(sym);
634 		visible = menu->prompt->visible.tri;
635 	} else
636 		visible = menu->prompt->visible.tri = expr_calc_value(menu->prompt->visible.expr);
637 
638 	if (visible != no)
639 		return true;
640 
641 	if (!sym || sym_get_tristate_value(menu->sym) == no)
642 		return false;
643 
644 	for (child = menu->list; child; child = child->next) {
645 		if (menu_is_visible(child)) {
646 			if (sym)
647 				sym->flags |= SYMBOL_DEF_USER;
648 			return true;
649 		}
650 	}
651 
652 	return false;
653 }
654 
655 const char *menu_get_prompt(struct menu *menu)
656 {
657 	if (menu->prompt)
658 		return menu->prompt->text;
659 	else if (menu->sym)
660 		return menu->sym->name;
661 	return NULL;
662 }
663 
664 struct menu *menu_get_parent_menu(struct menu *menu)
665 {
666 	enum prop_type type;
667 
668 	for (; menu != &rootmenu; menu = menu->parent) {
669 		type = menu->prompt ? menu->prompt->type : 0;
670 		if (type == P_MENU)
671 			break;
672 	}
673 	return menu;
674 }
675 
676 bool menu_has_help(struct menu *menu)
677 {
678 	return menu->help != NULL;
679 }
680 
681 const char *menu_get_help(struct menu *menu)
682 {
683 	if (menu->help)
684 		return menu->help;
685 	else
686 		return "";
687 }
688 
689 static void get_def_str(struct gstr *r, struct menu *menu)
690 {
691 	str_printf(r, "Defined at %s:%d\n",
692 		   menu->file->name, menu->lineno);
693 }
694 
695 static void get_dep_str(struct gstr *r, struct expr *expr, const char *prefix)
696 {
697 	if (!expr_is_yes(expr)) {
698 		str_append(r, prefix);
699 		expr_gstr_print(expr, r);
700 		str_append(r, "\n");
701 	}
702 }
703 
704 static void get_prompt_str(struct gstr *r, struct property *prop,
705 			   struct list_head *head)
706 {
707 	int i, j;
708 	struct menu *submenu[8], *menu, *location = NULL;
709 	struct jump_key *jump = NULL;
710 
711 	str_printf(r, "  Prompt: %s\n", prop->text);
712 
713 	get_dep_str(r, prop->menu->dep, "  Depends on: ");
714 	/*
715 	 * Most prompts in Linux have visibility that exactly matches their
716 	 * dependencies. For these, we print only the dependencies to improve
717 	 * readability. However, prompts with inline "if" expressions and
718 	 * prompts with a parent that has a "visible if" expression have
719 	 * differing dependencies and visibility. In these rare cases, we
720 	 * print both.
721 	 */
722 	if (!expr_eq(prop->menu->dep, prop->visible.expr))
723 		get_dep_str(r, prop->visible.expr, "  Visible if: ");
724 
725 	menu = prop->menu;
726 	for (i = 0; menu != &rootmenu && i < 8; menu = menu->parent) {
727 		submenu[i++] = menu;
728 		if (location == NULL && menu_is_visible(menu))
729 			location = menu;
730 	}
731 	if (head && location) {
732 		jump = xmalloc(sizeof(struct jump_key));
733 
734 		jump->target = location;
735 
736 		if (list_empty(head))
737 			jump->index = 0;
738 		else
739 			jump->index = list_entry(head->prev, struct jump_key,
740 						 entries)->index + 1;
741 
742 		list_add_tail(&jump->entries, head);
743 	}
744 
745 	str_printf(r, "  Location:\n");
746 	for (j = 4; --i >= 0; j += 2) {
747 		menu = submenu[i];
748 		if (jump && menu == location)
749 			jump->offset = strlen(r->s);
750 		str_printf(r, "%*c-> %s", j, ' ', menu_get_prompt(menu));
751 		if (menu->sym) {
752 			str_printf(r, " (%s [=%s])", menu->sym->name ?
753 				menu->sym->name : "<choice>",
754 				sym_get_string_value(menu->sym));
755 		}
756 		str_append(r, "\n");
757 	}
758 }
759 
760 static void get_symbol_props_str(struct gstr *r, struct symbol *sym,
761 				 enum prop_type tok, const char *prefix)
762 {
763 	bool hit = false;
764 	struct property *prop;
765 
766 	for_all_properties(sym, prop, tok) {
767 		if (!hit) {
768 			str_append(r, prefix);
769 			hit = true;
770 		} else
771 			str_printf(r, " && ");
772 		expr_gstr_print(prop->expr, r);
773 	}
774 	if (hit)
775 		str_append(r, "\n");
776 }
777 
778 /*
779  * head is optional and may be NULL
780  */
781 static void get_symbol_str(struct gstr *r, struct symbol *sym,
782 		    struct list_head *head)
783 {
784 	struct property *prop;
785 
786 	if (sym && sym->name) {
787 		str_printf(r, "Symbol: %s [=%s]\n", sym->name,
788 			   sym_get_string_value(sym));
789 		str_printf(r, "Type  : %s\n", sym_type_name(sym->type));
790 		if (sym->type == S_INT || sym->type == S_HEX) {
791 			prop = sym_get_range_prop(sym);
792 			if (prop) {
793 				str_printf(r, "Range : ");
794 				expr_gstr_print(prop->expr, r);
795 				str_append(r, "\n");
796 			}
797 		}
798 	}
799 
800 	/* Print the definitions with prompts before the ones without */
801 	for_all_properties(sym, prop, P_SYMBOL) {
802 		if (prop->menu->prompt) {
803 			get_def_str(r, prop->menu);
804 			get_prompt_str(r, prop->menu->prompt, head);
805 		}
806 	}
807 
808 	for_all_properties(sym, prop, P_SYMBOL) {
809 		if (!prop->menu->prompt) {
810 			get_def_str(r, prop->menu);
811 			get_dep_str(r, prop->menu->dep, "  Depends on: ");
812 		}
813 	}
814 
815 	get_symbol_props_str(r, sym, P_SELECT, "Selects: ");
816 	if (sym->rev_dep.expr) {
817 		expr_gstr_print_revdep(sym->rev_dep.expr, r, yes, "Selected by [y]:\n");
818 		expr_gstr_print_revdep(sym->rev_dep.expr, r, mod, "Selected by [m]:\n");
819 		expr_gstr_print_revdep(sym->rev_dep.expr, r, no, "Selected by [n]:\n");
820 	}
821 
822 	get_symbol_props_str(r, sym, P_IMPLY, "Implies: ");
823 	if (sym->implied.expr) {
824 		expr_gstr_print_revdep(sym->implied.expr, r, yes, "Implied by [y]:\n");
825 		expr_gstr_print_revdep(sym->implied.expr, r, mod, "Implied by [m]:\n");
826 		expr_gstr_print_revdep(sym->implied.expr, r, no, "Implied by [n]:\n");
827 	}
828 
829 	str_append(r, "\n\n");
830 }
831 
832 struct gstr get_relations_str(struct symbol **sym_arr, struct list_head *head)
833 {
834 	struct symbol *sym;
835 	struct gstr res = str_new();
836 	int i;
837 
838 	for (i = 0; sym_arr && (sym = sym_arr[i]); i++)
839 		get_symbol_str(&res, sym, head);
840 	if (!i)
841 		str_append(&res, "No matches found.\n");
842 	return res;
843 }
844 
845 
846 void menu_get_ext_help(struct menu *menu, struct gstr *help)
847 {
848 	struct symbol *sym = menu->sym;
849 	const char *help_text = nohelp_text;
850 
851 	if (menu_has_help(menu)) {
852 		if (sym->name)
853 			str_printf(help, "%s%s:\n\n", CONFIG_, sym->name);
854 		help_text = menu_get_help(menu);
855 	}
856 	str_printf(help, "%s\n", help_text);
857 	if (sym)
858 		get_symbol_str(help, sym, NULL);
859 }
860