kconfig: check prompt for choice while parsing

This can be checked on-the-fly.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

scripts/kconfig/menu.c

@@ -561,9 +561,6 @@ void menu_finalize(struct menu *parent)
 		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;

scripts/kconfig/parser.y

@@ -233,6 +233,12 @@ choice: T_CHOICE T_EOL
 
 choice_entry: choice choice_option_list
 {
+	if (!current_entry->prompt) {
+		fprintf(stderr, "%s:%d: error: choice must have a prompt\n",
+			current_entry->filename, current_entry->lineno);
+		yynerrs++;
+	}
+
 	$$ = menu_add_menu();
 };