checkpatch: improve macros with flow control test

The current test excludes any macro with ## concatenation from being
reported with hidden flow control.

Some macros are used with return or goto statements along with ##args or
##__VA_ARGS__.  A somewhat common case is a logging macro like
pr_info(fmt, ...) then a return or goto statement.

Check the concatenated variable for args or __VA_ARGS__ and allow those
macros to also be reported when they contain a return or goto.

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 8645706..77b293d 100755 (executable)
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -4539,7 +4539,7 @@ sub process {
                        #print "LINE<$lines[$ln-1]> len<" . length($lines[$ln-1]) . "\n";
 
                        $has_flow_statement = 1 if ($ctx =~ /\b(goto|return)\b/);
-                       $has_arg_concat = 1 if ($ctx =~ /\#\#/);
+                       $has_arg_concat = 1 if ($ctx =~ /\#\#/ && $ctx !~ /\#\#\s*(?:__VA_ARGS__|args)\b/);
 
                        $dstat =~ s/^.\s*\#\s*define\s+$Ident(?:\([^\)]*\))?\s*//;
                        $dstat =~ s/$;//g;