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Date: Thu, 12 Jun 2008 10:33:39 +0200
From: Sam Ravnborg <sam@ravnborg.org>
To: Ingo Molnar <mingo@elte.hu>
Cc: linux-kernel@vger.kernel.org, Steven Rostedt <rostedt@goodmis.org>,
       Thomas Gleixner <tglx@linutronix.de>,
       Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [tree] ftrace, v16
Message-ID: <20080612083339.GA25565@uranus.ravnborg.org>
References: <20080612075425.GB18419@elte.hu> <20080612075545.GA32585@elte.hu>
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Hi Ingo

>       kbuild: create new CFLAGS_REMOVE_(basename).o option

But no changes to Documentation/kbuild/makefiles.txt

Documentation must be included for new kbuild features.


> +ifdef CONFIG_DYNAMIC_FTRACE
> +CFLAGS_REMOVE_ftrace.o = -pg
> +endif

I can see where this comes from as we have:

    CFLAGS_ftrace.o := -foobar

But in all cases below I see the pattern:

ifdef CONFIG_FOO_BAR
CFLAGS_REMOVE_foobar.o = -pg
endif

And it would be nice to get this on one line instead.
And use a syntax we can somehow remember.

Today we have:
    ccflags-y := -foobar

to add options valid for the whole file.
So we should then add:
- possibility to remove an option valid for the whole file
- add/remove an option for a single file

The suggested syntax:
ccflags-remove-y := -foobar
ccflags-<file.o>-y := -foobar
ccflags-remove-<file.o>-y := -foobar

So in the case above for ftrace we would use:

ccflags-remove-ftrace.o-$(CONFIG_DYNAMIC_FTRACE) := -pg

Comments?

PS. Yes - I saw the patches when they were sent to linux-kbuild
but I just never came around commenting them.

	Sam