The patch titled
Subject: checkpatch: add constant comparison on left side test
has been added to the -mm tree. Its filename is
checkpatch-add-constant-comparison-on-left-side-test.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/checkpatch-add-constant-comparison-on-left-side-test.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/checkpatch-add-constant-comparison-on-left-side-test.patch
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*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
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------------------------------------------------------
From: Joe Perches <joe@xxxxxxxxxxx>
Subject: checkpatch: add constant comparison on left side test
"CONST <comparison> variable" checks like:
if (NULL != foo)
and
while (0 < bar(...))
where a constant (or what appears to be a constant like an upper case
identifier) is on the left of a comparison are generally preferred to be
written using the constant on the right side like:
if (foo != NULL)
and
while (bar(...) > 0)
Add a test for this.
Add a --fix option too, but only do it when the code is immediately
surrounded by parentheses to avoid misfixing things like "(0 < bar() +
constant)"
Signed-off-by: Joe Perches <joe@xxxxxxxxxxx>
Cc: Nicolas Morey Chaisemartin <nmorey@xxxxxxxxx>
Cc: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
Cc: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
scripts/checkpatch.pl | 29 +++++++++++++++++++++++++++++
1 file changed, 29 insertions(+)
diff -puN scripts/checkpatch.pl~checkpatch-add-constant-comparison-on-left-side-test scripts/checkpatch.pl
--- a/scripts/checkpatch.pl~checkpatch-add-constant-comparison-on-left-side-test
+++ a/scripts/checkpatch.pl
@@ -4231,6 +4231,35 @@ sub process {
}
}
+# comparisons with a constant or upper case identifier on the left
+# avoid cases like "foo + BAR < baz"
+# only fix matches surrounded by parentheses to avoid incorrect
+# conversions like "FOO < baz() + 5" being "misfixed" to "baz() > FOO + 5"
+ if ($^V && $^V ge 5.10.0 &&
+ $line =~ /^\+(.*)\b($Constant|[A-Z_][A-Z0-9_]*)\s*($Compare)\s*($LvalOrFunc)/) {
+ my $lead = $1;
+ my $const = $2;
+ my $comp = $3;
+ my $to = $4;
+ my $newcomp = $comp;
+ if ($lead !~ /$Operators\s*$/ &&
+ $to !~ /^(?:Constant|[A-Z_][A-Z0-9_]*)$/ &&
+ WARN("CONSTANT_COMPARISON",
+ "Comparisons should place the constant on the right side of the test\n" . $herecurr) &&
+ $fix) {
+ if ($comp eq "<") {
+ $newcomp = ">";
+ } elsif ($comp eq "<=") {
+ $newcomp = ">=";
+ } elsif ($comp eq ">") {
+ $newcomp = "<";
+ } elsif ($comp eq ">=") {
+ $newcomp = "<=";
+ }
+ $fixed[$fixlinenr] =~ s/\(\s*\Q$const\E\s*$Compare\s*\Q$to\E\s*\)/($to $newcomp $const)/;
+ }
+ }
+
# Return of what appears to be an errno should normally be negative
if ($sline =~ /\breturn(?:\s*\(+\s*|\s+)(E[A-Z]+)(?:\s*\)+\s*|\s*)[;:,]/) {
my $name = $1;
_
Patches currently in -mm which might be from joe@xxxxxxxxxxx are
ocfs2-neaten-do_error-ocfs2_error-and-ocfs2_abort.patch
cred-remove-unnecessary-kdebug-atomic-reads.patch
maintainers-credits-mark-maxraid-as-orphan-move-anil-ravindranath-to-credits.patch
checkpatch-warn-on-bare-sha-1-commit-ids-in-commit-logs.patch
checkpatch-add-warning-on-bug-bug_on-use.patch
checkpatch-improve-suspect_code_indent-test.patch
checkpatch-allow-longer-declaration-macros.patch
checkpatch-add-some-foo_destroy-functions-to-needless_if-tests.patch
checkpatch-report-the-right-line-when-using-emacs-and-file.patch
checkpatch-always-check-block-comment-styles.patch
checkpatch-make-strict-the-default-for-drivers-staging-files-and-patches.patch
checkpatch-emit-an-error-on-formats-with-0x%decimal.patch
checkpatch-avoid-some-commit-message-long-line-warnings.patch
checkpatch-add-__pmem-to-sparse-annotations.patch
checkpatch-add-constant-comparison-on-left-side-test.patch
fs-seq_file-convert-int-seq_vprint-seq_printf-etc-returns-to-void.patch
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