github-actions: Add license check

.github/verify_header.sh

@@ -0,0 +1,36 @@
+#!/bin/bash
+
+#
+# Copyright(c) 2022 Intel Corporation
+# SPDX-License-Identifier: BSD-3-Clause
+#
+
+# COPYRIGHT_REGEX is lowercase, because the whole line is
+# converted to lowercase before test against this regex.
+COPYRIGHT_REGEX="(copyright|\(c\))\s*([0-9]{4}(\s*-\s*([0-9]{4}))?)"
+LICENSE_REGEX="SPDX-License-Identifier: BSD-3-Clause$"
+YEAR=$(date +"%Y")
+
+unset copyright_header license_header
+
+# Read lines until proper copyright and license headers are found.
+while read -r line && [[ ! "$copyright_header" || ! "$license_header" ]]; do
+	if [[ "${line,,}" =~ $COPYRIGHT_REGEX ]]; then
+		# If the fourth regex group (from year range) doesn't exist,
+		# use the second regex group instead (from a single year).
+		copyright_year=${BASH_REMATCH[4]:-${BASH_REMATCH[2]}}
+
+		if [[ $copyright_year == $YEAR ]]; then
+			copyright_header="correct_copyright_header_found"
+		fi
+	elif [[ "$line" =~ $LICENSE_REGEX ]]; then
+		license_header="correct_license_header_found"
+	fi
+done < "$1"
+
+# Proper copyright and license info were found - all good.
+[[ "$copyright_header" && "$license_header" ]] && exit 0
+
+[[ ! "$copyright_header" ]] && echo >&2 "error: file '$1' does not contain any appropriate copyright info"
+[[ ! "$license_header" ]] && echo >&2 "error: file '$1' does not contain appropriate license identifier"
+exit 1

.github/workflows/license-check.yml

@@ -0,0 +1,43 @@
+name: Licence-date-verification
+permissions:
+  contents: read
+  pull-requests: read
+on:
+  pull_request:
+    branches:
+      - master
+      - v*
+
+env:
+  EXTENSIONS: "c h cpp py go sh mk spec service"
+  FILES: "configure configure.d/* *Makefile utils/casctl tools/pckgen.d/deb/debian/rules"
+jobs:
+  verify-date:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+      - name: Get changed files
+        id: changed-files
+        uses: tj-actions/[email protected]
+        with:
+          files_ignore: '.github/**'
+      - name: List all changed files
+        run: |
+          files_to_check=(${{ steps.changed-files.outputs.added_files }})
+          files_to_check+=(${{ steps.changed-files.outputs.modified_files }})
+
+          for file in ${files_to_check[@]}; do
+            for file_in_list in $FILES; do
+              if [[ "$file" == $file_in_list ]]; then
+                .github/verify_header.sh "$file"
+                continue 2
+              fi
+            done
+
+            extension=${file##*.}
+            if [[ "$EXTENSIONS" =~ $extension ]]; then
+              .github/verify_header.sh "$file"
+            fi
+          done