From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lf0-f66.google.com ([209.85.215.66]:40123 "EHLO mail-lf0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750915AbeANJ4g (ORCPT ); Sun, 14 Jan 2018 04:56:36 -0500 From: Ulf Magnusson Subject: [PATCH] kconfig: Document SYMBOL_OPTIONAL logic Date: Sun, 14 Jan 2018 10:56:20 +0100 Message-Id: <20180114095620.12088-1-ulfalizer@gmail.com> Sender: linux-kbuild-owner@vger.kernel.org List-ID: To: linux-kbuild@vger.kernel.org Cc: yamada.masahiro@socionext.com, sam@ravnborg.org, linux-kernel@vger.kernel.org, Ulf Magnusson Not obvious, especially if you don't already know how choices are implemented. No functional changes. Only comments added. Signed-off-by: Ulf Magnusson --- scripts/kconfig/menu.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/scripts/kconfig/menu.c b/scripts/kconfig/menu.c index 92d3f06cd8a2..372eb5d9fef3 100644 --- a/scripts/kconfig/menu.c +++ b/scripts/kconfig/menu.c @@ -548,6 +548,15 @@ void menu_finalize(struct menu *parent) sym->flags |= SYMBOL_WARNED; } + /* + * For non-optional choices, add a reverse dependency (corresponding to + * a select) of ' && 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, -- 2.14.1