// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2002 Roman Zippel <zippel@linux-m68k.org>
 */

#include <ctype.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>

#include "lkc.h"

static const char nohelp_text[] = "There is no help available for this option.";

struct menu rootmenu;
static struct menu **last_entry_ptr;

struct file *file_list;
struct file *current_file;

void menu_warn(struct menu *menu, const char *fmt, ...)
{
        va_list ap;
        va_start(ap, fmt);
        fprintf(stderr, "%s:%d:warning: ", menu->file->name, menu->lineno);
        vfprintf(stderr, fmt, ap);
        fprintf(stderr, "\n");
        va_end(ap);
}

static void prop_warn(struct property *prop, const char *fmt, ...)
{
        va_list ap;
        va_start(ap, fmt);
        fprintf(stderr, "%s:%d:warning: ", prop->file->name, prop->lineno);
        vfprintf(stderr, fmt, ap);
        fprintf(stderr, "\n");
        va_end(ap);
}

void _menu_init(void)
{
        current_entry = current_menu = &rootmenu;
        last_entry_ptr = &rootmenu.list;
}

void menu_add_entry(struct symbol *sym)
{
        struct menu *menu;

        menu = xmalloc(sizeof(*menu));
        memset(menu, 0, sizeof(*menu));
        menu->sym = sym;
        menu->parent = current_menu;
        menu->file = current_file;
        menu->lineno = zconf_lineno();

        *last_entry_ptr = menu;
        last_entry_ptr = &menu->next;
        current_entry = menu;
        if (sym)
                menu_add_symbol(P_SYMBOL, sym, NULL);
}

struct menu *menu_add_menu(void)
{
        last_entry_ptr = &current_entry->list;
        return current_menu = current_entry;
}

void menu_end_menu(void)
{
        last_entry_ptr = &current_menu->next;
        current_menu = current_menu->parent;
}

/*
 * Rewrites 'm' to 'm' && MODULES, so that it evaluates to 'n' when running
 * without modules
 */
static struct expr *rewrite_m(struct expr *e)
{
        if (!e)
                return e;

        switch (e->type) {
        case E_NOT:
                e->left.expr = rewrite_m(e->left.expr);
                break;
        case E_OR:
        case E_AND:
                e->left.expr = rewrite_m(e->left.expr);
                e->right.expr = rewrite_m(e->right.expr);
                break;
        case E_SYMBOL:
                /* change 'm' into 'm' && MODULES */
                if (e->left.sym == &symbol_mod)
                        return expr_alloc_and(e, expr_alloc_symbol(modules_sym));
                break;
        default:
                break;
        }
        return e;
}

void menu_add_dep(struct expr *dep)
{
        current_entry->dep = expr_alloc_and(current_entry->dep, dep);
}

void menu_set_type(int type)
{
        struct symbol *sym = current_entry->sym;

        if (sym->type == type)
                return;
        if (sym->type == S_UNKNOWN) {
                sym->type = type;
                return;
        }
        menu_warn(current_entry,
                "ignoring type redefinition of '%s' from '%s' to '%s'",
                sym->name ? sym->name : "<choice>",
                sym_type_name(sym->type), sym_type_name(type));
}

static struct property *menu_add_prop(enum prop_type type, char *prompt, struct expr *expr, struct expr *dep)
{
        struct property *prop = prop_alloc(type, current_entry->sym);

        prop->menu = current_entry;
        prop->expr = expr;
        prop->visible.expr = dep;

        if (prompt) {
                if (isspace(*prompt)) {
                        prop_warn(prop, "leading whitespace ignored");
                        while (isspace(*prompt))
                                prompt++;
                }
                if (current_entry->prompt && current_entry != &rootmenu)
                        prop_warn(prop, "prompt redefined");

                /* Apply all upper menus' visibilities to actual prompts. */
                if(type == P_PROMPT) {
                        struct menu *menu = current_entry;

                        while ((menu = menu->parent) != NULL) {
                                struct expr *dup_expr;

                                if (!menu->visibility)
                                        continue;
                                /*
                                 * Do not add a reference to the
                                 * menu's visibility expression but
                                 * use a copy of it.  Otherwise the
                                 * expression reduction functions
                                 * will modify expressions that have
                                 * multiple references which can
                                 * cause unwanted side effects.
                                 */
                                dup_expr = expr_copy(menu->visibility);

                                prop->visible.expr
                                        = expr_alloc_and(prop->visible.expr,
                                                         dup_expr);
                        }
                }

                current_entry->prompt = prop;
        }
        prop->text = prompt;

        return prop;
}

struct property *menu_add_prompt(enum prop_type type, char *prompt, struct expr *dep)
{
        return menu_add_prop(type, prompt, NULL, dep);
}

void menu_add_visibility(struct expr *expr)
{
        current_entry->visibility = expr_alloc_and(current_entry->visibility,
            expr);
}

void menu_add_expr(enum prop_type type, struct expr *expr, struct expr *dep)
{
        menu_add_prop(type, NULL, expr, dep);
}

void menu_add_symbol(enum prop_type type, struct symbol *sym, struct expr *dep)
{
        menu_add_prop(type, NULL, expr_alloc_symbol(sym), dep);
}

void menu_add_option_modules(void)
{
        if (modules_sym)
                zconf_error("symbol '%s' redefines option 'modules' already defined by symbol '%s'",
                            current_entry->sym->name, modules_sym->name);
        modules_sym = current_entry->sym;
}

void menu_add_option_defconfig_list(void)
{
        if (!sym_defconfig_list)
                sym_defconfig_list = current_entry->sym;
        else if (sym_defconfig_list != current_entry->sym)
                zconf_error("trying to redefine defconfig symbol");
        sym_defconfig_list->flags |= SYMBOL_NO_WRITE;
}

void menu_add_option_allnoconfig_y(void)
{
        current_entry->sym->flags |= SYMBOL_ALLNOCONFIG_Y;
}

static int menu_validate_number(struct symbol *sym, struct symbol *sym2)
{
        return sym2->type == S_INT || sym2->type == S_HEX ||
               (sym2->type == S_UNKNOWN && sym_string_valid(sym, sym2->name));
}

static void sym_check_prop(struct symbol *sym)
{
        struct property *prop;
        struct symbol *sym2;
        char *use;

        for (prop = sym->prop; prop; prop = prop->next) {
                switch (prop->type) {
                case P_DEFAULT:
                        if ((sym->type == S_STRING || sym->type == S_INT || sym->type == S_HEX) &&
                            prop->expr->type != E_SYMBOL)
                                prop_warn(prop,
                                    "default for config symbol '%s'"
                                    " must be a single symbol", sym->name);
                        if (prop->expr->type != E_SYMBOL)
                                break;
                        sym2 = prop_get_symbol(prop);
                        if (sym->type == S_HEX || sym->type == S_INT) {
                                if (!menu_validate_number(sym, sym2))
                                        prop_warn(prop,
                                            "'%s': number is invalid",
                                            sym->name);
                        }
                        if (sym_is_choice(sym)) {
                                struct property *choice_prop =
                                        sym_get_choice_prop(sym2);

                                if (!choice_prop ||
                                    prop_get_symbol(choice_prop) != sym)
                                        prop_warn(prop,
                                                  "choice default symbol '%s' is not contained in the choice",
                                                  sym2->name);
                        }
                        break;
                case P_SELECT:
                case P_IMPLY:
                        use = prop->type == P_SELECT ? "select" : "imply";
                        sym2 = prop_get_symbol(prop);
                        if (sym->type != S_BOOLEAN && sym->type != S_TRISTATE)
                                prop_warn(prop,
                                    "config symbol '%s' uses %s, but is "
                                    "not bool or tristate", sym->name, use);
                        else if (sym2->type != S_UNKNOWN &&
                                 sym2->type != S_BOOLEAN &&
                                 sym2->type != S_TRISTATE)
                                prop_warn(prop,
                                    "'%s' has wrong type. '%s' only "
                                    "accept arguments of bool and "
                                    "tristate type", sym2->name, use);
                        break;
                case P_RANGE:
                        if (sym->type != S_INT && sym->type != S_HEX)
                                prop_warn(prop, "range is only allowed "
                                                "for int or hex symbols");
                        if (!menu_validate_number(sym, prop->expr->left.sym) ||
                            !menu_validate_number(sym, prop->expr->right.sym))
                                prop_warn(prop, "range is invalid");
                        break;
                default:
                        ;
                }
        }
}

void menu_finalize(struct menu *parent)
{
        struct menu *menu, *last_menu;
        struct symbol *sym;
        struct property *prop;
        struct expr *parentdep, *basedep, *dep, *dep2, **ep;

        sym = parent->sym;
        if (parent->list) {
                /*
                 * This menu node has children. We (recursively) process them
                 * and propagate parent dependencies before moving on.
                 */

                if (sym && sym_is_choice(sym)) {
                        if (sym->type == S_UNKNOWN) {
                                /* find the first choice value to find out choice type */
                                current_entry = parent;
                                for (menu = parent->list; menu; menu = menu->next) {
                                        if (menu->sym && menu->sym->type != S_UNKNOWN) {
                                                menu_set_type(menu->sym->type);
                                                break;
                                        }
                                }
                        }
                        /* set the type of the remaining choice values */
                        for (menu = parent->list; menu; menu = menu->next) {
                                current_entry = menu;
                                if (menu->sym && menu->sym->type == S_UNKNOWN)
                                        menu_set_type(sym->type);
                        }

                        /*
                         * Use the choice itself as the parent dependency of
                         * the contained items. This turns the mode of the
                         * choice into an upper bound on the visibility of the
                         * choice value symbols.
                         */
                        parentdep = expr_alloc_symbol(sym);
                } else if (parent->prompt)
                        /* Menu node for 'menu' */
                        parentdep = parent->prompt->visible.expr;
                else
                        /* Menu node for 'if' */
                        parentdep = parent->dep;

                /* For each child menu node... */
                for (menu = parent->list; menu; menu = menu->next) {
                        /*
                         * Propagate parent dependencies to the child menu
                         * node, also rewriting and simplifying expressions
                         */
                        basedep = rewrite_m(menu->dep);
                        basedep = expr_transform(basedep);
                        basedep = expr_alloc_and(expr_copy(parentdep), basedep);
                        basedep = expr_eliminate_dups(basedep);
                        menu->dep = basedep;

                        if (menu->sym)
                                /*
                                 * Note: For symbols, all prompts are included
                                 * too in the symbol's own property list
                                 */
                                prop = menu->sym->prop;
                        else
                                /*
                                 * For non-symbol menu nodes, we just need to
                                 * handle the prompt
                                 */
                                prop = menu->prompt;

                        /* For each property... */
                        for (; prop; prop = prop->next) {
                                if (prop->menu != menu)
                                        /*
                                         * Two possibilities:
                                         *
                                         * 1. The property lacks dependencies
                                         *    and so isn't location-specific,
                                         *    e.g. an 'option'
                                         *
                                         * 2. The property belongs to a symbol
                                         *    defined in multiple locations and
                                         *    is from some other location. It
                                         *    will be handled there in that
                                         *    case.
                                         *
                                         * Skip the property.
                                         */
                                        continue;

                                /*
                                 * Propagate parent dependencies to the
                                 * property's condition, rewriting and
                                 * simplifying expressions at the same time
                                 */
                                dep = rewrite_m(prop->visible.expr);
                                dep = expr_transform(dep);
                                dep = expr_alloc_and(expr_copy(basedep), dep);
                                dep = expr_eliminate_dups(dep);
                                if (menu->sym && menu->sym->type != S_TRISTATE)
                                        dep = expr_trans_bool(dep);
                                prop->visible.expr = dep;

                                /*
                                 * Handle selects and implies, which modify the
                                 * dependencies of the selected/implied symbol
                                 */
                                if (prop->type == P_SELECT) {
                                        struct symbol *es = prop_get_symbol(prop);
                                        es->rev_dep.expr = expr_alloc_or(es->rev_dep.expr,
                                                        expr_alloc_and(expr_alloc_symbol(menu->sym), expr_copy(dep)));
                                } else if (prop->type == P_IMPLY) {
                                        struct symbol *es = prop_get_symbol(prop);
                                        es->implied.expr = expr_alloc_or(es->implied.expr,
                                                        expr_alloc_and(expr_alloc_symbol(menu->sym), expr_copy(dep)));
                                }
                        }
                }

                if (sym && sym_is_choice(sym))
                        expr_free(parentdep);

                /*
                 * Recursively process children in the same fashion before
                 * moving on
                 */
                for (menu = parent->list; menu; menu = menu->next)
                        menu_finalize(menu);
        } else if (sym) {
                /*
                 * Automatic submenu creation. If sym is a symbol and A, B, C,
                 * ... are consecutive items (symbols, menus, ifs, etc.) that
                 * all depend on sym, then the following menu structure is
                 * created:
                 *
                 *      sym
                 *       +-A
                 *       +-B
                 *       +-C
                 *       ...
                 *
                 * This also works recursively, giving the following structure
                 * if A is a symbol and B depends on A:
                 *
                 *      sym
                 *       +-A
                 *       | +-B
                 *       +-C
                 *       ...
                 */

                basedep = parent->prompt ? parent->prompt->visible.expr : NULL;
                basedep = expr_trans_compare(basedep, E_UNEQUAL, &symbol_no);
                basedep = expr_eliminate_dups(expr_transform(basedep));

                /* Examine consecutive elements after sym */
                last_menu = NULL;
                for (menu = parent->next; menu; menu = menu->next) {
                        dep = menu->prompt ? menu->prompt->visible.expr : menu->dep;
                        if (!expr_contains_symbol(dep, sym))
                                /* No dependency, quit */
                                break;
                        if (expr_depends_symbol(dep, sym))
                                /* Absolute dependency, put in submenu */
                                goto next;

                        /*
                         * Also consider it a dependency on sym if our
                         * dependencies contain sym and are a "superset" of
                         * sym's dependencies, e.g. '(sym || Q) && R' when sym
                         * depends on R.
                         *
                         * Note that 'R' might be from an enclosing menu or if,
                         * making this a more common case than it might seem.
                         */
                        dep = expr_trans_compare(dep, E_UNEQUAL, &symbol_no);
                        dep = expr_eliminate_dups(expr_transform(dep));
                        dep2 = expr_copy(basedep);
                        expr_eliminate_eq(&dep, &dep2);
                        expr_free(dep);
                        if (!expr_is_yes(dep2)) {
                                /* Not superset, quit */
                                expr_free(dep2);
                                break;
                        }
                        /* Superset, put in submenu */
                        expr_free(dep2);
                next:
                        menu_finalize(menu);
                        menu->parent = parent;
                        last_menu = menu;
                }
                expr_free(basedep);
                if (last_menu) {
                        parent->list = parent->next;
                        parent->next = last_menu->next;
                        last_menu->next = NULL;
                }

                sym->dir_dep.expr = expr_alloc_or(sym->dir_dep.expr, parent->dep);
        }
        for (menu = parent->list; menu; menu = menu->next) {
                if (sym && sym_is_choice(sym) &&
                    menu->sym && !sym_is_choice_value(menu->sym)) {
                        current_entry = menu;
                        menu->sym->flags |= SYMBOL_CHOICEVAL;
                        if (!menu->prompt)
                                menu_warn(menu, "choice value must have a prompt");
                        for (prop = menu->sym->prop; prop; prop = prop->next) {
                                if (prop->type == P_DEFAULT)
                                        prop_warn(prop, "defaults for choice "
                                                  "values not supported");
                                if (prop->menu == menu)
                                        continue;
                                if (prop->type == P_PROMPT &&
                                    prop->menu->parent->sym != sym)
                                        prop_warn(prop, "choice value used outside its choice group");
                        }
                        /* Non-tristate choice values of tristate choices must
                         * depend on the choice being set to Y. The choice
                         * values' dependencies were propagated to their
                         * properties above, so the change here must be re-
                         * propagated.
                         */
                        if (sym->type == S_TRISTATE && menu->sym->type != S_TRISTATE) {
                                basedep = expr_alloc_comp(E_EQUAL, sym, &symbol_yes);
                                menu->dep = expr_alloc_and(basedep, menu->dep);
                                for (prop = menu->sym->prop; prop; prop = prop->next) {
                                        if (prop->menu != menu)
                                                continue;
                                        prop->visible.expr = expr_alloc_and(expr_copy(basedep),
                                                                            prop->visible.expr);
                                }
                        }
                        menu_add_symbol(P_CHOICE, sym, NULL);
                        prop = sym_get_choice_prop(sym);
                        for (ep = &prop->expr; *ep; ep = &(*ep)->left.expr)
                                ;
                        *ep = expr_alloc_one(E_LIST, NULL);
                        (*ep)->right.sym = menu->sym;
                }

                /*
                 * This code serves two purposes:
                 *
                 * (1) Flattening 'if' blocks, which do not specify a submenu
                 *     and only add dependencies.
                 *
                 *     (Automatic submenu creation might still create a submenu
                 *     from an 'if' before this code runs.)
                 *
                 * (2) "Undoing" any automatic submenus created earlier below
                 *     promptless symbols.
                 *
                 * Before:
                 *
                 *      A
                 *      if ... (or promptless symbol)
                 *       +-B
                 *       +-C
                 *      D
                 *
                 * After:
                 *
                 *      A
                 *      if ... (or promptless symbol)
                 *      B
                 *      C
                 *      D
                 */
                if (menu->list && (!menu->prompt || !menu->prompt->text)) {
                        for (last_menu = menu->list; ; last_menu = last_menu->next) {
                                last_menu->parent = parent;
                                if (!last_menu->next)
                                        break;
                        }
                        last_menu->next = menu->next;
                        menu->next = menu->list;
                        menu->list = NULL;
                }
        }

        if (sym && !(sym->flags & SYMBOL_WARNED)) {
                if (sym->type == S_UNKNOWN)
                        menu_warn(parent, "config symbol defined without type");

                if (sym_is_choice(sym) && !parent->prompt)
                        menu_warn(parent, "choice must have a prompt");

                /* Check properties connected to this symbol */
                sym_check_prop(sym);
                sym->flags |= SYMBOL_WARNED;
        }

        /*
         * For non-optional choices, add a reverse dependency (corresponding to
         * a select) of '<visibility> && m'. This prevents the user from
         * setting the choice mode to 'n' when the choice is visible.
         *
         * This would also work for non-choice symbols, but only non-optional
         * choices clear SYMBOL_OPTIONAL as of writing. Choices are implemented
         * as a type of symbol.
         */
        if (sym && !sym_is_optional(sym) && parent->prompt) {
                sym->rev_dep.expr = expr_alloc_or(sym->rev_dep.expr,
                                expr_alloc_and(parent->prompt->visible.expr,
                                        expr_alloc_symbol(&symbol_mod)));
        }
}

bool menu_has_prompt(struct menu *menu)
{
        if (!menu->prompt)
                return false;
        return true;
}

/*
 * Determine if a menu is empty.
 * A menu is considered empty if it contains no or only
 * invisible entries.
 */
bool menu_is_empty(struct menu *menu)
{
        struct menu *child;

        for (child = menu->list; child; child = child->next) {
                if (menu_is_visible(child))
                        return(false);
        }
        return(true);
}

bool menu_is_visible(struct menu *menu)
{
        struct menu *child;
        struct symbol *sym;
        tristate visible;

        if (!menu->prompt)
                return false;

        if (menu->visibility) {
                if (expr_calc_value(menu->visibility) == no)
                        return false;
        }

        sym = menu->sym;
        if (sym) {
                sym_calc_value(sym);
                visible = menu->prompt->visible.tri;
        } else
                visible = menu->prompt->visible.tri = expr_calc_value(menu->prompt->visible.expr);

        if (visible != no)
                return true;

        if (!sym || sym_get_tristate_value(menu->sym) == no)
                return false;

        for (child = menu->list; child; child = child->next) {
                if (menu_is_visible(child)) {
                        if (sym)
                                sym->flags |= SYMBOL_DEF_USER;
                        return true;
                }
        }

        return false;
}

const char *menu_get_prompt(struct menu *menu)
{
        if (menu->prompt)
                return menu->prompt->text;
        else if (menu->sym)
                return menu->sym->name;
        return NULL;
}

struct menu *menu_get_root_menu(struct menu *menu)
{
        return &rootmenu;
}

struct menu *menu_get_parent_menu(struct menu *menu)
{
        enum prop_type type;

        for (; menu != &rootmenu; menu = menu->parent) {
                type = menu->prompt ? menu->prompt->type : 0;
                if (type == P_MENU)
                        break;
        }
        return menu;
}

bool menu_has_help(struct menu *menu)
{
        return menu->help != NULL;
}

const char *menu_get_help(struct menu *menu)
{
        if (menu->help)
                return menu->help;
        else
                return "";
}

static void get_prompt_str(struct gstr *r, struct property *prop,
                           struct list_head *head)
{
        int i, j;
        struct menu *submenu[8], *menu, *location = NULL;
        struct jump_key *jump = NULL;

        str_printf(r, "Prompt: %s\n", prop->text);
        menu = prop->menu->parent;
        for (i = 0; menu != &rootmenu && i < 8; menu = menu->parent) {
                bool accessible = menu_is_visible(menu);

                submenu[i++] = menu;
                if (location == NULL && accessible)
                        location = menu;
        }
        if (head && location) {
                jump = xmalloc(sizeof(struct jump_key));

                if (menu_is_visible(prop->menu)) {
                        /*
                         * There is not enough room to put the hint at the
                         * beginning of the "Prompt" line. Put the hint on the
                         * last "Location" line even when it would belong on
                         * the former.
                         */
                        jump->target = prop->menu;
                } else
                        jump->target = location;

                if (list_empty(head))
                        jump->index = 0;
                else
                        jump->index = list_entry(head->prev, struct jump_key,
                                                 entries)->index + 1;

                list_add_tail(&jump->entries, head);
        }

        if (i > 0) {
                str_printf(r, "  Location:\n");
                for (j = 4; --i >= 0; j += 2) {
                        menu = submenu[i];
                        if (jump && menu == location)
                                jump->offset = strlen(r->s);
                        str_printf(r, "%*c-> %s", j, ' ',
                                   menu_get_prompt(menu));
                        if (menu->sym) {
                                str_printf(r, " (%s [=%s])", menu->sym->name ?
                                        menu->sym->name : "<choice>",
                                        sym_get_string_value(menu->sym));
                        }
                        str_append(r, "\n");
                }
        }
}

/*
 * get property of type P_SYMBOL
 */
static struct property *get_symbol_prop(struct symbol *sym)
{
        struct property *prop = NULL;

        for_all_properties(sym, prop, P_SYMBOL)
                break;
        return prop;
}

static void get_symbol_props_str(struct gstr *r, struct symbol *sym,
                                 enum prop_type tok, const char *prefix)
{
        bool hit = false;
        struct property *prop;

        for_all_properties(sym, prop, tok) {
                if (!hit) {
                        str_append(r, prefix);
                        hit = true;
                } else
                        str_printf(r, " && ");
                expr_gstr_print(prop->expr, r);
        }
        if (hit)
                str_append(r, "\n");
}

/*
 * head is optional and may be NULL
 */
static void get_symbol_str(struct gstr *r, struct symbol *sym,
                    struct list_head *head)
{
        struct property *prop;

        if (sym && sym->name) {
                str_printf(r, "Symbol: %s [=%s]\n", sym->name,
                           sym_get_string_value(sym));
                str_printf(r, "Type  : %s\n", sym_type_name(sym->type));
                if (sym->type == S_INT || sym->type == S_HEX) {
                        prop = sym_get_range_prop(sym);
                        if (prop) {
                                str_printf(r, "Range : ");
                                expr_gstr_print(prop->expr, r);
                                str_append(r, "\n");
                        }
                }
        }
        for_all_prompts(sym, prop)
                get_prompt_str(r, prop, head);

        prop = get_symbol_prop(sym);
        if (prop) {
                str_printf(r, "  Defined at %s:%d\n", prop->menu->file->name,
                        prop->menu->lineno);
                if (!expr_is_yes(prop->visible.expr)) {
                        str_append(r, "  Depends on: ");
                        expr_gstr_print(prop->visible.expr, r);
                        str_append(r, "\n");
                }
        }

        get_symbol_props_str(r, sym, P_SELECT, "  Selects: ");
        if (sym->rev_dep.expr) {
                expr_gstr_print_revdep(sym->rev_dep.expr, r, yes, "  Selected by [y]:\n");
                expr_gstr_print_revdep(sym->rev_dep.expr, r, mod, "  Selected by [m]:\n");
                expr_gstr_print_revdep(sym->rev_dep.expr, r, no, "  Selected by [n]:\n");
        }

        get_symbol_props_str(r, sym, P_IMPLY, "  Implies: ");
        if (sym->implied.expr) {
                expr_gstr_print_revdep(sym->implied.expr, r, yes, "  Implied by [y]:\n");
                expr_gstr_print_revdep(sym->implied.expr, r, mod, "  Implied by [m]:\n");
                expr_gstr_print_revdep(sym->implied.expr, r, no, "  Implied by [n]:\n");
        }

        str_append(r, "\n\n");
}

struct gstr get_relations_str(struct symbol **sym_arr, struct list_head *head)
{
        struct symbol *sym;
        struct gstr res = str_new();
        int i;

        for (i = 0; sym_arr && (sym = sym_arr[i]); i++)
                get_symbol_str(&res, sym, head);
        if (!i)
                str_append(&res, "No matches found.\n");
        return res;
}


void menu_get_ext_help(struct menu *menu, struct gstr *help)
{
        struct symbol *sym = menu->sym;
        const char *help_text = nohelp_text;

        if (menu_has_help(menu)) {
                if (sym->name)
                        str_printf(help, "%s%s:\n\n", CONFIG_, sym->name);
                help_text = menu_get_help(menu);
        }
        str_printf(help, "%s\n", help_text);
        if (sym)
                get_symbol_str(help, sym, NULL);
}