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Message-ID: <213451dcf8036133426aa04b6f377a16c6b53ff5.camel@infradead.org>
Subject: Re: [PATCH] KVM: selftests: add -MP to CFLAGS
From:   David Woodhouse <dwmw2@infradead.org>
To:     David Laight <David.Laight@ACULAB.COM>,
        "kvm@vger.kernel.org" <kvm@vger.kernel.org>
Cc:     Paolo Bonzini <pbonzini@redhat.com>, Shuah Khan <shuah@kernel.org>,
        "linux-kselftest@vger.kernel.org" <linux-kselftest@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Date:   Mon, 30 Oct 2023 09:45:33 +0000
In-Reply-To: <3fa5bdded7504d6582cf01f4db4cd6b4@AcuMS.aculab.com>
References: <9fc8b5395321abbfcaf5d78477a9a7cd350b08e4.camel@infradead.org>
         <3fa5bdded7504d6582cf01f4db4cd6b4@AcuMS.aculab.com>
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On Sun, 2023-10-29 at 21:13 +0000, David Laight wrote:
> From: David Woodhouse
> > Sent: 28 October 2023 20:35
> >=20
> > Using -MD without -MP causes build failures when a header file is delet=
ed
> > or moved. With -MP, the compiler will emit phony targets for the header
> > files it lists as dependencies, and the Makefiles won't refuse to attem=
pt
> > to rebuild a C unit which no longer includes the deleted header.
>=20
> Won't a phony target stop a header being built if there is
> an actual rule to build it?

It probably would have taken you about the same time to find the answer
for yourself, as it took to write that email. Why don't you try it?

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