Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Sun, 11 Feb 2018 13:01:57 -0800
From:   Matthew Wilcox <willy@infradead.org>
To:     Randy Dunlap <rdunlap@infradead.org>
Cc:     Philippe Ombredanne <pombredanne@nexb.com>,
        Igor Stoppa <igor.stoppa@huawei.com>,
        Jonathan Corbet <corbet@lwn.net>,
        Kees Cook <keescook@chromium.org>, mhocko@kernel.org,
        labbott@redhat.com, jglisse@redhat.com,
        Christoph Hellwig <hch@infradead.org>, cl@linux.com,
        linux-security-module@vger.kernel.org, linux-mm@kvack.org,
        LKML <linux-kernel@vger.kernel.org>,
        kernel-hardening@lists.openwall.com
Subject: Re: [PATCH 2/6] genalloc: selftest
Message-ID: <20180211210157.GB4680@bombadil.infradead.org>
References: <20180211031920.3424-1-igor.stoppa@huawei.com>
 <20180211031920.3424-3-igor.stoppa@huawei.com>
 <CAOFm3uGNVu87qYzPufu+gGbTwuhp3cjfhKuNDkcmwn3+ysKTdg@mail.gmail.com>
 <f95a064d-75e9-6ff3-2c11-4158a0ad1ca9@infradead.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <f95a064d-75e9-6ff3-2c11-4158a0ad1ca9@infradead.org>
User-Agent: Mutt/1.9.2 (2017-12-15)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Sun, Feb 11, 2018 at 12:27:14PM -0800, Randy Dunlap wrote:
> On 02/11/18 12:22, Philippe Ombredanne wrote:
> > nit... For a comment in .h this line should be instead its own comment
> > as the first line:
> >> +/* SPDX-License-Identifier: GPL-2.0 */
> 
> Why are we treating header files (.h) differently than .c files?
> Either one can use the C++ "//" comment syntax.

This is now documented!

Documentation/process/license-rules.rst:

   If a specific tool cannot handle the standard comment style, then the
   appropriate comment mechanism which the tool accepts shall be used. This
   is the reason for having the "/\* \*/" style comment in C header
   files. There was build breakage observed with generated .lds files where
   'ld' failed to parse the C++ comment. This has been fixed by now, but
   there are still older assembler tools which cannot handle C++ style
   comments.

Personally, I find this disappointing.  I find this:

// SPDX-License-Identifier: GPL-2.0+
/*
 * XArray implementation
 * Copyright (c) 2017 Microsoft Corporation
 * Author: Matthew Wilcox <mawilcox@microsoft.com>
 */

much less visually appealling than

/*
 * XArray implementation
 * Copyright (c) 2017 Microsoft Corporation
 * Author: Matthew Wilcox <mawilcox@microsoft.com>
 * SPDX-License-Identifier: GPL-2.0+
 */

I can't see this variation making a tag extraction tool harder to write.