checkpatch: handle string concatenation in simple #defines

Adjacent strings indicate concatentation, therefore look at identifiers
directly adjacent to literal strings as strings too.  This allows us to
better detect the form below and accept it as a simple constant:

    #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

Signed-off-by: Andy Whitcroft <apw@canonical.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 6 insertions, 0 deletions

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 95ba30a24dcf..01a65988a057 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -2894,6 +2894,12 @@ sub process {
                         {
                         }
 
+                        # Flatten any obvious string concatentation.
+                        while ($dstat =~ s/("X*")\s*$Ident/$1/ ||
+                               $dstat =~ s/$Ident\s*("X*")/$1/)
+                        {
+                        }
+
                         my $exceptions = qr{
                                 $Declare|
                                 module_param_named|