File 0006-perl-5.41-precedence-warning-kernel-doc.patch of Package linux-lts66
https://patchew.org/QEMU/20250819115648.2125709-1-peter.maydell@linaro.org/
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From: Peter Maydell <peter.maydell@linaro.org>
To: qemu-devel@nongnu.org
Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Subject: [PATCH] scripts/kernel-doc: Avoid new Perl precedence warning
Date: Tue, 19 Aug 2025 12:56:48 +0100
Message-ID: <20250819115648.2125709-1-peter.maydell@linaro.org>
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Newer versions of Perl (5.41.x and up) emit a warning for code in
kernel-doc:
Possible precedence problem between ! and pattern match (m//) at /scripts/=
kernel-doc line 1597.
This is because the code does:
if (!$param =3D~ /\w\.\.\.$/) {
In Perl, the ! operator has higher precedence than the =3D~
pattern-match binding, so the effect of this condition is to first
logically-negate the string $param into a true-or-false value and
then try to pattern match it against the regex, which in this case
will always fail. This is almost certainly not what the author
intended.
In the new Python version of kernel-doc in the Linux kernel,
the equivalent code is written:
if KernRe(r'\w\.\.\.$').search(param):
# For named variable parameters of the form `x...`,
# remove the dots
param =3D param[:-3]
else:
# Handles unnamed variable parameters
param =3D "..."
which is a more sensible way of writing the behaviour you would
get if you put in brackets to make the regex match first and
then negate the result.
Take this as the intended behaviour, and update the Perl to match.
For QEMU, this produces no change in output, presumably because we
never used the "unnamed variable parameters" syntax.
Cc: qemu-stable@nongnu.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Daniel P. Berrang=C3=A9 <berrange@redhat.com>
Reviewed-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
---
This obviously will clash with the "import the python script"
patchseries, but I figured it was worth providing the minimal
fix for the benefit of stable backports.
The kernel's copy of kernel-doc.pl still has this bug.
---
scripts/kernel-doc | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)
#diff --git a/scripts/kernel-doc b/scripts/kernel-doc
#index fec83f53eda..117ec8fcd1f 100755
#--- a/scripts/kernel-doc
#+++ b/scripts/kernel-doc
#@@ -1594,13 +1594,12 @@ sub push_parameter($$$$$) {
#
# if ($type eq "" && $param =~ /\.\.\.$/)
# {
#- if (!$param =~ /\w\.\.\.$/) {
#- # handles unnamed variable parameters
#- $param = "...";
#- }
#- elsif ($param =~ /\w\.\.\.$/) {
#+ if ($param =~ /\w\.\.\.$/) {
# # for named variable parameters of the form `x...`, remove the dots
# $param =~ s/\.\.\.$//;
#+ } else {
#+ # handles unnamed variable parameters
#+ $param = "...";
# }
# if (!defined $parameterdescs{$param} || $parameterdescs{$param} eq "") {
# $parameterdescs{$param} = "variable arguments";
#--
#2.43.0
The mail list coloring mangled this patch pretty bad.
I redid the original patch to create a clean version above.
I think the patch unnecessairly rearranged code so I redid it my way.
Cleaned and fixed for Arch linux-lts66
diff -pNaru3 a/scripts/kernel-doc b/scripts/kernel-doc
--- a/scripts/kernel-doc 2025-10-29 09:04:43.000000000 -0400
+++ b/scripts/kernel-doc 2025-10-30 19:54:05.146063059 -0400
@@ -1567,11 +1567,11 @@ sub push_parameter($$$$$) {
if ($type eq "" && $param =~ /\.\.\.$/)
{
- if (!$param =~ /\w\.\.\.$/) {
+ if (!($param =~ /\w\.\.\.$/)) {
# handles unnamed variable parameters
$param = "...";
}
- elsif ($param =~ /\w\.\.\.$/) {
+ else {
# for named variable parameters of the form `x...`, remove the dots
$param =~ s/\.\.\.$//;
}
