From mboxrd@z Thu Jan 1 00:00:00 1970 From: Darren Hart Subject: Re: [PATCH 1/3] rt-tests: Support user supplied CFLAGS and LDFLAGS Date: Wed, 21 Mar 2012 12:11:59 -0700 Message-ID: <4F6A27FF.5020107@linux.intel.com> References: <3343440fb02872debc8b49be5261aec530a205f3.1332270303.git.dvhart@linux.intel.com> <4F691C88.2020907@linux.intel.com> <20120321191022.GA6857@denix.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: John Kacur , linux-rt-users@vger.kernel.org, Clark Williams To: Denys Dmytriyenko Return-path: Received: from mga01.intel.com ([192.55.52.88]:43832 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756459Ab2CUTMp (ORCPT ); Wed, 21 Mar 2012 15:12:45 -0400 In-Reply-To: <20120321191022.GA6857@denix.org> Sender: linux-rt-users-owner@vger.kernel.org List-ID: On 03/21/2012 12:10 PM, Denys Dmytriyenko wrote: > On Tue, Mar 20, 2012 at 05:10:48PM -0700, Darren Hart wrote: >> >> >> On 03/20/2012 04:58 PM, John Kacur wrote: >>> On Tue, Mar 20, 2012 at 8:05 PM, Darren Hart wrote: >>>> Accept user supplied CFLAGS and LDFLAGS, overwriting the >>>> Makefile supplied versions. This can cause the build to >>>> fail if the user does not provide at least what the Makefile >>>> defines, but so be it. >>>> >>>> Signed-off-by: Darren Hart >>>> CC: Clark Williams >>>> CC: John Kacur >>>> CC: Denys Dmytriyenko >>>> --- >>> >>> I was just wondering what you need LDFLAGS for? Chatting with Darren >>> on IRC, it seems like you're using -Wl to pass options via gcc to the >>> linker, and we don't have loadable libs either. Maybe you could resend >>> the patch with just the CFLAGS change until we have a real world >>> reason for LDFLAGS >> >> Denys, >> >> Am I missing a reason why we need LDFLAGS? With the current Makefile. we >> could just add anything we want to CFLAGS in a pinch anyway... > > Darren, > > From OE-Core config files: > > LINKER_HASH_STYLE ??= "gnu" > TARGET_LINK_HASH_STYLE ?= "${@['-Wl,--hash-style=gnu',''][d.getVar('LINKER_HASH_STYLE', True) != 'gnu']}" > export TARGET_LDFLAGS = "-Wl,-O1 ${TARGET_LINK_HASH_STYLE}" > ASNEEDED = "-Wl,--as-needed" > TARGET_LDFLAGS += "${ASNEEDED}" > export LDFLAGS = "${TARGET_LDFLAGS}" > > > So, those are still linker flags (altough passed through -Wl to gcc), hence > they belong to LDFLAGS, not CFLAGS. Arguably, you only need to pass CFLAGS > during compile stage and LDFLAGS during link stage. On the other hand, as a > workaround, I was passing them to TARGET_CC_ARCH, which gets embedded into CC > and won't distinguish between compile/link stages... > > So rt-tests just gets away not using LDFLAGS and re-using CFLAGS for the link > stage. :) But the current Makefile as it is now won't honor CFLAGS being set > from outside, unless you pass them explicitly on the command line to make, or > call make with -e flag. Right, at the very least I'll resubmit the patch allowing override of CFLAGS. But I wanted to know if you felt there was any need to support overriding of LDFLAGS for rt-tests which doesn't build any shared libs. -- Darren Hart Intel Open Source Technology Center Yocto Project - Linux Kernel