checkpatch: add test for assignment at start of line

Kernel style seems to prefer line wrapping an assignment with the
assignment operator on the previous line like:

	<leading tabs>	identifier =
				expression;
over
	<leading tabs>	identifier
				= expression;

somewhere around a 50:1 ratio

$ git grep -P "[^=]=\s*$" -- "*.[ch]" | wc -l
52008
$ git grep -P "^\s+[\*\/\+\|\%\-]?=[^=>]" | wc -l
1161

So add a --strict test for that condition.

Link: http://lkml.kernel.org/r/1522275726.2210.12.camel@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index d2464002bb40dfaba8ab52f4f0df07b94ce1b42d..5deee8bd0baeb77ed1b66652c5fc62793dbaa37d 100755 (executable)
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -3062,6 +3062,12 @@ sub process {
                        }
                }
 
+# check for assignments on the start of a line
+               if ($sline =~ /^\+\s+($Assignment)[^=]/) {
+                       CHK("ASSIGNMENT_CONTINUATIONS",
+                           "Assignment operator '$1' should be on the previous line\n" . $hereprev);
+               }
+
 # check for && or || at the start of a line
                if ($rawline =~ /^\+\s*(&&|\|\|)/) {
                        CHK("LOGICAL_CONTINUATIONS",