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References: <20171215181810.4122-1-marcandre.lureau@redhat.com>
From: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <abddfb99-c6ca-70ba-eae9-16f57f60b41d@redhat.com>
Date: Mon, 18 Dec 2017 13:49:52 +0100
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Subject: Re: [Qemu-devel] [PATCH] checkpatch: warn when using volatile with
 a comment
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To: =?UTF-8?Q?Marc-Andr=c3=a9_Lureau?= <marcandre.lureau@redhat.com>, qemu-devel@nongnu.org
Cc: famz@redhat.com, lersek@redhat.com

On 15/12/2017 19:18, Marc-Andr=C3=A9 Lureau wrote:
> Instead of an error, lower to a warning message, assuming the comment
> gives some justification.
>=20
> Discussed in:
> '[Qemu-devel] [PATCH] dump-guest-memory.py: fix "You can't do that with=
out a process to debug"'
>=20
> Suggested-by: Fam Zheng <famz@redhat.com>
> Signed-off-by: Marc-Andr=C3=A9 Lureau <marcandre.lureau@redhat.com>

We can drop the error at all if there is a comment.  Also, "volatile sig_=
atomic_t" is probably self-explanatory and usually correct.  So what abou=
t this:

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index f5a523af10..3dc27d9656 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -2475,13 +2475,11 @@ sub process {
=20
 # no volatiles please
 		my $asm_volatile =3D qr{\b(__asm__|asm)\s+(__volatile__|volatile)\b};
-		if ($line =3D~ /\bvolatile\b/ && $line !~ /$asm_volatile/) {
-			my $msg =3D "Use of volatile is usually wrong: see Documentation/vola=
tile-considered-harmful.txt\n" . $herecurr;
-			if (ctx_has_comment($first_line, $linenr)) {
-				WARN($msg);
-			} else {
-				ERROR($msg);
-			}
+		if ($line =3D~ /\bvolatile\b/ && $line !~ /$asm_volatile/ &&
+                    $line !~ /sig_atomic_t/ &&
+                    !ctx_has_comment($first_line, $linenr)) {
+			my $msg =3D "Use of volatile is usually wrong, please add a comment\n=
" . $herecurr;
+                        ERROR($msg);
 		}
=20
 # warn about #if 0