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 (!$param =~ /\w\.\.\.$/) { In Perl, the ! operator has higher precedence than the =~ 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 = param[:-3] else: # Handles unnamed variable parameters param = "..." 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-sta...@nongnu.org Signed-off-by: Peter Maydell <peter.mayd...@linaro.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