[#3732] Migrate tools/print-generated-files.sh away from autotools

tools/amend-gitattributes.sh

@@ -0,0 +1,30 @@
+#!/bin/sh
+
+# Copyright (C) 2025 Internet Systems Consortium, Inc. ("ISC")
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# Exit with error if commands exit with non-zero and if undefined variables are
+# used.
+set -eu
+
+root_path=$(cd "$(dirname "${0}")/.." && pwd)
+cd "${root_path}"
+
+# Write to .gitattributes.
+find . -type f -name '.gitattributes' -exec rm -f {} \;
+for i in $(./tools/print-generated-files.sh); do
+    # We need to be lenient because we call this script in premium too. Files might not exist.
+    if test ! -f "${i}"; then
+        continue
+    fi
+
+    # Align to 32 characters.
+    dir=$(dirname "${i}")
+    name="/$(basename "${i}")"
+    length=$(( 32 - ${#name} ))
+
+    printf "%s%${length}s -diff merge=ours\\n" "${name}" ' ' >> "${dir}/.gitattributes"
+done