[PATCH] checkpatch: Verify SPDX comment style

[Joe Perches <joe@perches.com>]

Using SPDX commenting style // or /* is specified for
various file types in Documentation/process/license-rules.rst
so add an appropriate test for .[chsS] files because many
proposed file additions and patches do not use the correct style.

Signed-off-by: Joe Perches <joe@perches.com>
---
 scripts/checkpatch.pl | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 155fa9305166..44c2a876be43 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -3039,6 +3039,14 @@ sub process {
 					$comment = '..';
 				}
 
+# check SPDX comment style for .[chsS] files
+				if ($realfile =~ /\.[chsS]$/ &&
+				    $rawline =~ /SPDX-License-Identifier:/ &&
+				    $rawline !~ /^\+\s*\Q$comment\E\s*/) {
+					WARN("SPDX_LICENSE_TAG",
+					     "Improper SPDX comment style for '$realfile', please use '$comment' instead\n" . $herecurr);
+				}
+
 				if ($comment !~ /^$/ &&
 				    $rawline !~ /^\+\Q$comment\E SPDX-License-Identifier: /) {
 					 WARN("SPDX_LICENSE_TAG",