Subject: Re: [PATCH trace-cmd 3/3] Revert "trace-cmd: Use conditional
 assignment of CC and AR"
From: Steven Rostedt <rostedt@goodmis.org>
To: Darren Hart <dvhart@linux.intel.com>
Cc: David Sharp <dhsharp@google.com>, linux-kernel@vger.kernel.org,
        mrubin@google.com
In-Reply-To: <4D7828F9.7000906@linux.intel.com>
References: <1299715137-22768-1-git-send-email-dhsharp@google.com>
	 <1299715137-22768-3-git-send-email-dhsharp@google.com>
	 <4D7828F9.7000906@linux.intel.com>
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Date: Wed, 09 Mar 2011 20:36:37 -0500
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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, 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)

Then you could just update BUILD_CC and that will update CC for you.

-- Steve


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