From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:32983) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1caiJE-0005M9-5l for qemu-devel@nongnu.org; Mon, 06 Feb 2017 07:22:16 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1caiJA-0006YH-8h for qemu-devel@nongnu.org; Mon, 06 Feb 2017 07:22:16 -0500 Received: from mx1.redhat.com ([209.132.183.28]:44970) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1caiJA-0006Y5-2w for qemu-devel@nongnu.org; Mon, 06 Feb 2017 07:22:12 -0500 References: <20170206112953.16993-1-berrange@redhat.com> <20170206120515.GJ3029@redhat.com> From: Paolo Bonzini Message-ID: <221a40d6-9688-d384-0d59-5b0fefe8206e@redhat.com> Date: Mon, 6 Feb 2017 13:22:08 +0100 MIME-Version: 1.0 In-Reply-To: <20170206120515.GJ3029@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] rules: don't try to create missing include dirs List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Daniel P. Berrange" , Peter Maydell Cc: QEMU Developers , Alberto Garcia , Stefan Hajnoczi On 06/02/2017 13:05, Daniel P. Berrange wrote: >>> $(shell mkdir -p ./ $(sort $(dir $($v)))) >>> - $(shell cd $(BUILD_DIR) && mkdir -p ./ $(sort $(dir $($v)))) >> I know this is the same syntax as the existing line above >> and we're deleting it anyway, but what does it actually do? >> When does telling mkdir to create "./" make sense? > No idea why the ./ was there originally - it appears to serve no > purpose. The useful bit is the stuff afterwards - the $($v) bit. > It gets populated based on the variable being unnested. For example > > block-obj-y = block.o blockjob.o block/ nbd/ > > will make $v contain "block nbd", hence cause creation of those > dirs in the the build dir. "mkdir -p" with no arguments gives an error, the "./" shuts it up. Paolo