[PATCH] Deprecate checkpatch.pl --file mode; add warning; add --file-force

[Andi Kleen <ak@suse.de>]

I'm not entirely sure who collects checkpatch patches for .25 -- i thought it
was Andy W., but he doesn't seem to answer. Anyways whoever does it please
queue this patch for the next checkpatch.pl update. Or perhaps it could
be put into -mm?

Thanks,
-Andi
----

Deprecate checkpatch.pl --file mode; add warning; add --file-force

As discussed on linux-kernel checkpatch.pl only patches for whole
files have a significant cost. Better such changes should be only
done together with other changes. Add a explicit warning about
this; deprecate --file and add a --file-force instead.

Signed-off-by: Andi Kleen <ak@suse.de>

---
 scripts/checkpatch.pl |   20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

Index: linux/scripts/checkpatch.pl
===================================================================
--- linux.orig/scripts/checkpatch.pl
+++ linux/scripts/checkpatch.pl
@@ -21,6 +21,7 @@ my $tst_type = 0;
 my $emacs = 0;
 my $terse = 0;
 my $file = 0;
+my $file_force = 0;
 my $check = 0;
 my $summary = 1;
 my $mailback = 0;
@@ -34,6 +35,7 @@ GetOptions(
 	'emacs!'	=> \$emacs,
 	'terse!'	=> \$terse,
 	'file!'		=> \$file,
+	'file-force!'	=> \$file_force,
 	'subjective!'	=> \$check,
 	'strict!'	=> \$check,
 	'root=s'	=> \$root,
@@ -50,12 +52,28 @@ if ($#ARGV < 0) {
 	print "         --no-tree    => run without a kernel tree\n";
 	print "         --terse      => one line per report\n";
 	print "         --emacs      => emacs compile window format\n";
-	print "         --file       => check a source file\n";
+	print " 	--file	     => check a source file (deprecated)\n";
+	print " 	--file-force => check a source file\n";
 	print "         --strict     => enable more subjective tests\n";
 	print "         --root       => path to the kernel tree root\n";
 	exit(1);
 }
 
+if ($file) {
+	print <<EOL
+WARNING: Using --file mode. Please do not send patches to linux-kernel
+that change whole existing files if you did not significantly change most
+of the the file for other reasons anyways or just wrote the file newly
+from scratch. Pure code style patches have a significant cost in a
+quickly changing code base like Linux because they cause rejects
+with other changes.
+If you're sure you want to use whole file mode please use --file-force
+EOL
+;
+	exit(1);
+};
+$file = $file_force;
+
 if ($terse) {
 	$emacs = 1;
 	$quiet++;