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Message-ID: <a7de235e15dbba2df9eb7ef82750ea8b6eae2b7b.camel@perches.com>
Subject: Re: [PATCH 1/2] checkpatch: warn when unknown tags are used for
 links
From:   Joe Perches <joe@perches.com>
To:     Kai =?ISO-8859-1?Q?Wasserb=E4ch?= <kai@dev.carbon-project.org>,
        linux-kernel@vger.kernel.org
Cc:     Thorsten Leemhuis <linux@leemhuis.info>,
        Andrew Morton <akpm@linux-foundation.org>,
        Andy Whitcroft <apw@canonical.com>,
        Dwaipayan Ray <dwaipayanray1@gmail.com>,
        Lukas Bulwahn <lukas.bulwahn@gmail.com>
Date:   Thu, 08 Dec 2022 11:58:58 -0800
In-Reply-To: <869badb999d4021dd6efd792f53fc2859257c350.1670527774.git.kai@dev.carbon-project.org>
References: <cover.1670152844.git.kai@dev.carbon-project.org>
         <869badb999d4021dd6efd792f53fc2859257c350.1670527774.git.kai@dev.carbon-project.org>
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On Thu, 2022-12-08 at 20:32 +0100, Kai Wasserb?ch wrote:
> Issue a warning when encountering URLs behind unknown tags, as Linus
> recently stated ```please stop making up random tags that make no sense.
> Just use "Link:"```[1]. That statement was triggered by an use of
> 'BugLink', but that's not the only tag people invented:
> 
> $ git log -100000 --format=email -P --grep='^\w+:[ \t]*http' | \

Please use the --no-merges output

>   grep -Poh '^\w+:[ \t]*http' | \
>   sort | uniq -c | sort -rn | head -n 20
>  103889 Link: http
>     415 BugLink: http
>     372 Patchwork: http
>     270 Closes: http
>     221 Bug: http
>     121 References: http
>     101 v1: http
>      77 Bugzilla: http
>      60 URL: http
>      59 v2: http
>      37 Datasheet: http
>      35 v3: http
>      19 v4: http
>      12 v5: http
>       9 Ref: http
>       9 Fixes: http
>       9 Buglink: http
>       8 v6: http
>       8 Reference: http
>       7 V1: http
> 
> Some of these non-standard tags make it harder for external tools that
> rely on use of proper tags. One of those tools is the regression
> tracking bot 'regzbot', which looks out for "Link:" tags pointing to
> reports of tracked regressions.
> 
> The initial idea was to use a disallow list to raise an error when
> encountering known unwanted tags like BugLink:; during review it was
> requested to use a list of allowed tags instead[2].
[]
> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
[]
> @@ -3239,6 +3239,13 @@ sub process {
>  			$commit_log_possible_stack_dump = 0;
>  		}
>  
> +# Check for odd tags before a URI/URL
> +		if ($in_commit_log &&
> +		    $line =~ /^\s*(\w+):\s*http/ && $1 !~ /^Link/) {
> +			WARN("COMMIT_LOG_USE_LINK",
> +			     "Unknown link reference '$1:', use 'Link:' instead.\n" . $herecurr);

This would allow LinkFoo: so better would be

		    $line =~ /^\s*(\w+):\s*http/ && $1 ne 'Link')
or
		    $line =~ /^\s*(\w+):\s*http/ && $1 !~ /^Link$/) {

(and checkpatch doesn't use periods after output messages)

Maybe better as well would be to use something like the below to
better describe the preferred location of patch versioning info.

# Check for odd tags before a URI/URL
		if ($in_commit_log &&
		    $line =~ /^\s*(\w+):\s*http/ && $1 ne 'Link') {
			if ($1 =~ /^v(?:ersion)?\d+/i) {
				WARN("COMMIT_LOG_VERSIONING",
				     "Patch version information should be after the --- line\n" . $herecurr);
			} else {
				WARN("COMMIT_LOG_USE_LINK",
				     "Unknown link reference '$1:', use 'Link:' instead\n" . $herecurr);
			}
		}