kconfig: add menu_get_ext_help function to display more information

The three functions are moved from mconf.c, then they can be shared in
all menuconfig & gconfig & xconfig & config.

  +void menu_get_ext_help(struct menu *menu, struct gstr *help)
  +static void get_prompt_str(struct gstr *r, struct property *prop)
  +void get_symbol_str(struct gstr *r, struct symbol *sym)

Signed-off-by: Cheng Renquan <crquan@gmail.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

scripts/kconfig/lkc_proto.h

@@ -17,6 +17,8 @@ P(menu_get_root_menu,struct menu *,(struct menu *menu));
 P(menu_get_parent_menu,struct menu *,(struct menu *menu));
 P(menu_has_help,bool,(struct menu *menu));
 P(menu_get_help,const char *,(struct menu *menu));
+P(get_symbol_str,void,(struct gstr *r, struct symbol *sym));
+P(menu_get_ext_help,void,(struct menu *menu, struct gstr *help));
 
 /* symbol.c */
 P(symbol_hash,struct symbol *,[SYMBOL_HASHSIZE]);

scripts/kconfig/menu.c

@@ -9,6 +9,9 @@
 #define LKC_DIRECT_LINK
 #include "lkc.h"
 
+static const char nohelp_text[] = N_(
+	"There is no help available for this kernel option.\n");
+
 struct menu rootmenu;
 static struct menu **last_entry_ptr;
 
@@ -451,3 +454,79 @@ const char *menu_get_help(struct menu *menu)
 	else
 		return "";
 }
+
+static void get_prompt_str(struct gstr *r, struct property *prop)
+{
+	int i, j;
+	struct menu *submenu[8], *menu;
+
+	str_printf(r, _("Prompt: %s\n"), _(prop->text));
+	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");
+	}
+	menu = prop->menu->parent;
+	for (i = 0; menu != &rootmenu && i < 8; menu = menu->parent)
+		submenu[i++] = menu;
+	if (i > 0) {
+		str_printf(r, _("  Location:\n"));
+		for (j = 4; --i >= 0; j += 2) {
+			menu = submenu[i];
+			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");
+		}
+	}
+}
+
+void get_symbol_str(struct gstr *r, struct symbol *sym)
+{
+	bool hit;
+	struct property *prop;
+
+	if (sym && sym->name)
+		str_printf(r, "Symbol: %s [=%s]\n", sym->name,
+			   sym_get_string_value(sym));
+	for_all_prompts(sym, prop)
+		get_prompt_str(r, prop);
+	hit = false;
+	for_all_properties(sym, prop, P_SELECT) {
+		if (!hit) {
+			str_append(r, "  Selects: ");
+			hit = true;
+		} else
+			str_printf(r, " && ");
+		expr_gstr_print(prop->expr, r);
+	}
+	if (hit)
+		str_append(r, "\n");
+	if (sym->rev_dep.expr) {
+		str_append(r, _("  Selected by: "));
+		expr_gstr_print(sym->rev_dep.expr, r);
+		str_append(r, "\n");
+	}
+	str_append(r, "\n\n");
+}
+
+void menu_get_ext_help(struct menu *menu, struct gstr *help)
+{
+	struct symbol *sym = menu->sym;
+
+	if (menu_has_help(menu)) {
+		if (sym->name) {
+			str_printf(help, "CONFIG_%s:\n\n", sym->name);
+			str_append(help, _(menu_get_help(menu)));
+			str_append(help, "\n");
+		}
+	} else {
+		str_append(help, nohelp_text);
+	}
+	get_symbol_str(help, sym);
+}