First step of updating the copyright dates

Add a script "update-copyright.sh" that automatically updates the
copyright dates, which was mostly copied from Ronan's PR KhronosGroup#339.
Manually change the copyright line for a few files that don't follow
our regular pattern.

The file "copyright-ccby.txt" seems to be copied from the Vulkan repo.
I think we don't even use it, but the copyright notice listed
"Khronos Group" instead of "The Khronos Goup".  I replaced this file
with the latest version from the Vulkan repo, which has the corrected
name.

.github/workflows/CI.yml

@@ -1,4 +1,4 @@
-# Copyright 2021 The Khronos Group, Inc.
+# Copyright 2021-2023 The Khronos Group, Inc.
 # SPDX-License-Identifier: Apache-2.0
 
 # CI to build asciidoctor spec targets, on push or manually

adoc/Makefile

@@ -1,4 +1,4 @@
-# Copyright 2011-2022 The Khronos Group, Inc.
+# Copyright 2011-2023 The Khronos Group, Inc.
 #
 # SPDX-License-Identifier: Apache-2.0
 

adoc/config/copyright-ccby.txt

@@ -1,4 +1,3 @@
-Copyright (c) 2011-2021 Khronos Group, Inc. This work is licensed under a
-http://creativecommons.org/licenses/by/4.0/[Creative Commons
-Attribution 4.0 International License].
+Copyright 2014-2023 The Khronos Group Inc.
 
+SPDX-License-Identifier: CC-BY-4.0

adoc/scripts/doctransformer.py

@@ -1,4 +1,4 @@
-# Copyright 2023 The Khronos Group Inc.
+# Copyright 2023-2023 The Khronos Group Inc.
 #
 # SPDX-License-Identifier: Apache-2.0
 

adoc/scripts/update-copyright.sh

@@ -0,0 +1,42 @@
+#! /bin/bash
+# Copyright 2024-2024 The Khronos Group Inc.
+#
+# SPDX-License-Identifier: Apache-2.0
+
+# Run this script at the beginning of the year to update the copyright dates
+# on all the source files.  Run it from the root of the repo.  The script only
+# updates copyright dates in the following forms:
+#
+# Copyright <begin-date>-<end-date> The Khronos Group
+# Copyright (c) <begin-date>-<end-date> The Khronos Group
+#
+# And it only updates the <end-date> if the original value is the previous year
+# (i.e. last year, assuming you run the script at the beginning of the year).
+#
+# We intentionally do not update copyright notices from other companies.
+#
+# The script also performs a check for Khronos copyright notices that do not
+# follow either of the patterns above.  If any such notices are found, they are
+# printed to stdout.  These lines should be examined and modified manually.
+
+thisyear=`date +%Y`
+lastyear=`expr $thisyear - 1`
+
+function update_code() {
+  file_name="$1"
+  # Update the copyright dates and names
+  sed -i \
+    -e "s/Copyright\\( (c)\\)\\? \\([12][0-9][0-9][0-9]\\)-$lastyear The Khronos Group/Copyright\\1 \\2-$thisyear The Khronos Group/g" \
+    "$file_name"
+}
+
+git ls-files | while read -r f ; do
+  update_code "$f"
+
+  # See if the file contains a Khronos copyright that was not updated.
+  # We skip the file for this script because the sed expression above causes
+  # a false report.
+  if [ "$f" != "adoc/scripts/update-copyright.sh" ]; then
+    grep -iH 'copyright.*khronos' "$f" | grep -v "[12][0-9][0-9][0-9]-$thisyear"
+  fi
+done