Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754160AbdFNBPi (ORCPT ); Tue, 13 Jun 2017 21:15:38 -0400 Received: from conssluserg-03.nifty.com ([210.131.2.82]:33439 "EHLO conssluserg-03.nifty.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753996AbdFNBPg (ORCPT ); Tue, 13 Jun 2017 21:15:36 -0400 DKIM-Filter: OpenDKIM Filter v2.10.3 conssluserg-03.nifty.com v5E1FGaO000599 X-Nifty-SrcIP: [209.85.161.177] MIME-Version: 1.0 In-Reply-To: <593FB5F2.4040206@cn.fujitsu.com> References: <1496740073-3320-1-git-send-email-caoj.fnst@cn.fujitsu.com> <593FB5F2.4040206@cn.fujitsu.com> From: Masahiro Yamada Date: Wed, 14 Jun 2017 10:15:14 +0900 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v2] Kbuild: tiny correction on `make help` To: Cao jin Cc: Linux Kernel Mailing List , Linux Kbuild mailing list , Michal Marek Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 712 Lines: 27 2017-06-13 18:52 GMT+09:00 Cao jin : > Yamada-san, > > I have a question on the current top level Makefile. There are > following lines, I have trouble to understand "firstword x$(MAKEFLAGS)" > in 2nd line, why there is a 'x' there? > > > ifneq ($(filter 4.%,$(MAKE_VERSION)),) # make-4 > ifneq ($(filter %s ,$(firstword x$(MAKEFLAGS))),) I do not understand the 'x' either. Michal suggested the code according to the following: https://patchwork.kernel.org/patch/3291301/ (I hope Michal can help you.) My first guess was, it was added just in case $(MAKEFLAGS) is empty. Actually $(firstword ) seems to work with empty argument, though. -- Best Regards Masahiro Yamada