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| author | Dwaipayan Ray <dwaipayanray1@gmail.com> | 2020-12-15 20:45:15 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-12-15 22:46:17 -0800 |
| commit | 70eb2275ff8e0b4cafe67176674d580c987c071d (patch) | |
| tree | 2e5107d68fa302b6831300b85474c164aef25c06 /scripts | |
| parent | 831242ab8dffab4cf2f89c597d5902ac86caeefe (diff) | |
| download | linux-stable-70eb2275ff8e0b4cafe67176674d580c987c071d.tar.gz linux-stable-70eb2275ff8e0b4cafe67176674d580c987c071d.tar.bz2 linux-stable-70eb2275ff8e0b4cafe67176674d580c987c071d.zip | |
checkpatch: add warning for unnecessary use of %h[xudi] and %hh[xudi]
Modifiers %h and %hh should never be used.
Commit cbacb5ab0aa0 ("docs: printk-formats: Stop encouraging use of
unnecessary %h[xudi] and %hh[xudi]") specifies that:
"Standard integer promotion is already done and %hx and %hhx is useless
so do not encourage the use of %hh[xudi] or %h[xudi]."
"The "h" and "hh" things should never be used. The only reason for them
being used if you have an "int", but you want to print it out as a
"char" (and honestly, that is a really bad reason, you'd be better off
just using a proper cast to make the code more obvious)."
Add a new check to emit a warning on finding an unneeded use of %h or
%hh modifier.
Also add a fix option to the check.
Link: https://lore.kernel.org/lkml/4910042649a4f3ab22fac93191b8c1fa0a2e17c3.camel@perches.com/
Link: https://lkml.kernel.org/r/20201128200046.78739-1-dwaipayanray1@gmail.com
Signed-off-by: Dwaipayan Ray <dwaipayanray1@gmail.com>
Suggested-by: Joe Perches <joe@perches.com>
Suggested-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'scripts')
| -rwxr-xr-x | scripts/checkpatch.pl | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl index d7616a6f1436..2716b9bfc0c2 100755 --- a/scripts/checkpatch.pl +++ b/scripts/checkpatch.pl @@ -6102,6 +6102,28 @@ sub process { "Avoid logging continuation uses where feasible\n" . $herecurr); } +# check for unnecessary use of %h[xudi] and %hh[xudi] in logging functions + if (defined $stat && + $line =~ /\b$logFunctions\s*\(/ && + index($stat, '"') >= 0) { + my $lc = $stat =~ tr@\n@@; + $lc = $lc + $linenr; + my $stat_real = get_stat_real($linenr, $lc); + pos($stat_real) = index($stat_real, '"'); + while ($stat_real =~ /[^\"%]*(%[\#\d\.\*\-]*(h+)[idux])/g) { + my $pspec = $1; + my $h = $2; + my $lineoff = substr($stat_real, 0, $-[1]) =~ tr@\n@@; + if (WARN("UNNECESSARY_MODIFIER", + "Integer promotion: Using '$h' in '$pspec' is unnecessary\n" . "$here\n$stat_real\n") && + $fix && $fixed[$fixlinenr + $lineoff] =~ /^\+/) { + my $nspec = $pspec; + $nspec =~ s/h//g; + $fixed[$fixlinenr + $lineoff] =~ s/\Q$pspec\E/$nspec/; + } + } + } + # check for mask then right shift without a parentheses if ($perl_version_ok && $line =~ /$LvalOrFunc\s*\&\s*($LvalOrFunc)\s*>>/ && |