tracking: replacing old license headers with SPDX headers

[N11cc00]

Description

Currently, RIOT OS uses an outdated and not machine-friendly way of declaring the license and the copyright at the start of the file. The exact layout of the copyright headers is also not consistent. For this reason the SPDX standard provides a consistent way to declare license and copyright information that can easily be read by humans and programs such as REUSE.

Basically, all .c and .h files will have to be converted except for the ones provided by vendors.

Before:

/*
 * Copyright (C) 2016 Inria
 * Copyright (C) 2018 Freie Universität Berlin
 *
 * This file is subject to the terms and conditions of the GNU Lesser
 * General Public License v2.1. See the file LICENSE in the top level
 * directory for more details.
 */

After (with the SPDX standard for headers):

/*
 * SPDX-FileCopyrightText: 2016 Inria
 * SPDX-FileCopyrightText: 2018 Freie Universität Berlin
 * SPDX-License-Identifier: LGPL-2.1-only
 */

Fixed directories

This issue will track the different parts of RIOT that have already been converted to the SPDX standard. Multiple PRs will have to be created.

• drivers drivers: change old license headers to SPDX format #21516

Testing procedure

The script can be found here but it is still WIP and only prints the new header format. It is able to convert 90% of all old license headers into the new SPDX format. Some edge cases will need to be fixed or manually adjusted.

References

This issue was brought up by @mguetschow

[crasbe]

IMO it would make sense to also adapt the static test to check for that license format: https://github.com/RIOT-OS/RIOT/blob/master/dist/tools/licenses/check.sh

[N11cc00]

IMO it would make sense to also adapt the static test to check for that license format: https://github.com/RIOT-OS/RIOT/blob/master/dist/tools/licenses/check.sh

What the CI script does at the moment is to check whether the file contains the correct string as found in the license directory. Now, SPDX offers parsers that can do just that by processing the header information. I don't know if we want to incorporate that into our CI.