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>

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 95ba30a..01a6598 100755 (executable)
--- 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|