Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752546Ab1CJGnd (ORCPT ); Thu, 10 Mar 2011 01:43:33 -0500 Received: from mga09.intel.com ([134.134.136.24]:55883 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752275Ab1CJGnb (ORCPT ); Thu, 10 Mar 2011 01:43:31 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.62,295,1297065600"; d="scan'208";a="718538637" Message-ID: <4D787312.7080609@linux.intel.com> Date: Wed, 09 Mar 2011 22:43:30 -0800 From: Darren Hart User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.14) Gecko/20110223 Lightning/1.0b2 Thunderbird/3.1.8 MIME-Version: 1.0 To: David Sharp CC: Steven Rostedt , linux-kernel@vger.kernel.org, mrubin@google.com Subject: Re: [PATCH trace-cmd 3/3] Revert "trace-cmd: Use conditional assignment of CC and AR" References: <1299715137-22768-1-git-send-email-dhsharp@google.com> <1299715137-22768-3-git-send-email-dhsharp@google.com> <4D7828F9.7000906@linux.intel.com> <1299720997.15854.276.camel@gandalf.stny.rr.com> <4D783038.8080103@linux.intel.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3041 Lines: 85 On 03/09/2011 06:27 PM, David Sharp wrote: > On Wed, Mar 9, 2011 at 5:58 PM, Darren Hart wrote: >> On 03/09/2011 05:36 PM, Steven Rostedt wrote: >>> On Wed, 2011-03-09 at 17:27 -0800, Darren Hart wrote: >>>> On 03/09/2011 03:58 PM, David Sharp wrote: >>>>> >>>>> This reverts commit 6c696cec3f264a9399241b6e648f58bc97117d49. >>>>> >>>>> Make has default values CC and AR of 'cc' and 'ar' respectively. This >>>>> means >>>>> that "CC ?= anything" will never have effect, because CC is always >>>>> already set. >>>>> Because of this, 6c696cec makes setting CROSS_COMPILE from the command >>>>> line or >>>>> environment useless. >>>> >>>> The problem with this approach is it prevents the user from setting CC >>>> explicitly with the environment which is a very common way of using a >>>> specific version of gcc (for example). It also places restrictions on >>>> the filename of the compiler (it must end in gcc - so gcc-4.5.1 cannot >>>> work), this isn't acceptable. >>>> >>>> You could use CC=your-cross-compiler, and if that doesn't work for you, >>>> you could prepare a patch that conditionally sets CC only if >>>> CROSS_COMPILE is set, but please do not simply revert this patch which >>>> solved a real problem with the Makefile. >>> >>> Hmm, but the thing is, the change did not work, >> >> It did work for me as I was setting CC= on the command line. >> >> unless your environment >>> >>> for some reason does not supply a 'cc'. Or that 'cc' defaulted to the >>> compiler that you wanted, where 'gcc' would not. >>> >>> Thus, would you be fine with something like: >>> >>> BUILD_CC ?= $(CROSS_COMPILE)gcc >>> CC = $(BUILD_CC) >> >> This would also work, but what is wrong with: >> >> dvhart@doubt:templates$ cat Makefile >> ifdef CROSS_COMPILE >> CC = $(CROSS_COMPILE)gcc >> AR = $(CROSS_COMPILE)ar >> endif >> >> all: >> echo "CC: $(CC)" >> >> dvhart@doubt:templates$ make -s >> CC: cc >> >> dvhart@doubt:templates$ CC=gcc-4.5.1 make -s >> CC: gcc-4.5.1 >> >> dvhart@doubt:templates$ CROSS_COMPILE=my-cross- make -s >> CC: my-cross-gcc >> >> >> Seems to meet everyone's needs without changing any tools/scripts/etc that >> have used trace-cmd before or after the CC ?= wreckage. > > It's a little odd that the default CC is "cc" unless you supply > CROSS_COMPILE, then it's "gcc". I'd probably be okay with this, but I > would think it's weird. > > I don't know the answers, but if we take the kernel Makefile as a > template, then setting CC doesn't work. The kernel is a bit special I believe as it is pretty tied to gcc. Is trace-cmd tied to gcc to such a degree that we want to make it difficult for people to try different compilers? -- Darren Intel Open Source Technology Center Yocto Project - Linux Kernel -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/