[PATCH RFC] checkpatch: flag split arithmetic operations with CHECK

[Nicholas Mc Guire]

Simple arithmetic operations should be on one line, if they can be fit,
rather than splitting at the operator. As this is not in the CodingStyle it 
is limited to --strict use of checkpatch.pl and emits a CHECK only.

Signed-off-by: Nicholas Mc Guire <hofrat@xxxxxxxxx>
---

Patches by people like me splitting arithmetic operations, e.g.:
                       hdw->encoder_run_timer.expires = jiffies +
                                msecs_to_jiffies(TIME_MSEC_ENCODER_OK);
were flagged by Joe Perches but checkpatch.pl was not fussing, not even
with --strict. This extension should flag such lines as CHECK only, as 
this is not mandated by the CodingStyle and in some cases they are 
justified (e.g. kernel/sched/fair.c:760 and a few other examples in that
file)

Limitation: this is for + and - only still have to figure out some false
            positives for the * and /, % ($Arithmetic) case.

patch is against 4.0-rc2 (localversion-next is -next-20150505)

 scripts/checkpatch.pl |   13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 89b1df4..051ea99 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -2577,6 +2577,19 @@ sub process {
 			    "Logical continuations should be on the previous line\n" . $hereprev);
 		}
 
+# check for + or - at the end of a line
+		if ($rawline =~ /^\+[^*]*(\+|-)$/) {
+			CHK("ARITHMETIC_CONTINUATIONS",
+			    "Arithmetic expressions should be on one line\n" . $hereprev);
+		}
+
+# check for + or - at beginning of a line but exclude ++var/--var
+		if (!($rawline =~ /^\+\s*(\+\+|--).*$/) &&
+		   $rawline =~ /^\+\s*(\+|-).*$/) {
+			CHK("ARITHMETIC_CONTINUATIONS",
+			    "Arithmetic expressions should be on one line\n" . $hereprev);
+		}
+
 # check multi-line statement indentation matches previous line
 		if ($^V && $^V ge 5.10.0 &&
 		    $prevline =~ /^\+([ \t]*)((?:$c90_Keywords(?:\s+if)\s*)|(?:$Declare\s*)?(?:$Ident|\(\s*\*\s*$Ident\s*\))\s*|$Ident\s*=\s*$Ident\s*)\(.*(\&\&|\|\||,)\s*$/) {
-- 
1.7.10.4

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/