Re: [PATCH v3 4/4] Remove extra copies of licenses and license headers

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On Sun, 9 Oct 2022, Julien Grall wrote:
> Hi Stefano,
> 
> On 08/10/2022 01:15, Stefano Stabellini wrote:
> > From: Stefano Stabellini <stefano.stabellini@xxxxxxx>
> > 
> > Remove the extra copy of the GPL license and license copyright headers
> > from CONTRIBUTING and the top-level COPYING.
> > 
> > Mention of the LICENSES/ directory and also mention the SPDX tag.
> > 
> > SPDX support is still in progress and COPYING files in subdirectories
> > still need to be updated.
> > 
> > Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxx>
> > ---
> > Patch new in v3
> > ---
> >   CONTRIBUTING | 150 ++--------------------
> >   COPYING      | 351 +--------------------------------------------------
> >   2 files changed, 17 insertions(+), 484 deletions(-)
> > 
> > diff --git a/CONTRIBUTING b/CONTRIBUTING
> > index 6ec146baf0..7b6b03fb96 100644
> > --- a/CONTRIBUTING
> > +++ b/CONTRIBUTING
> > @@ -19,10 +19,6 @@ Most notably:
> >    - tools/xl           : LGPL v2.1
> >    - xen/include/public : MIT license
> >   -The COMMON COPYRIGHT NOTICES section of this document contains
> > -sample copyright notices for the most common licenses used within
> > -this repository.
> > -
> 
> How about replacing this section with something like:
> 
> " See LICENSES/ for a list of licenses and SPDX tags currently used."

Good idea


> >   When creating new components, new files, or importing code please follow
> >   the conventions outlined below. As a general rule, whenever code using a
> >   license other than GPLv2 is introduced, attention must be drawn to the
> > @@ -32,20 +28,22 @@ deviation. Any new code must be GPLv2 compatible.
> >   New components
> >   --------------
> >   -When creating new components and directories that contain a
> > -significant amount of files that are licensed under licenses other
> > -than GPLv2 or the license specified in the COPYING file, please
> > -create a new COPYING file in that directory containing a copy of the
> > -license text and a rationale for using a different license. This helps
> > -ensure that the license of this new component/directory is maintained
> > -consistently with the original intention.
> > +When creating new components and directories that contain a significant
> > +amount of files that are licensed under licenses other than GPLv2,
> > +please create a new COPYING file in that directory with the rationale
> > +for using a different license. This helps ensure that the license of
> > +this new component/directory is maintained consistently with the
> > +original intention.
> 
> I don't understand why the wording "or the license specified in the COPYING
> file" is dropped. To me, the sentence was indicating that it is not necessary
> to create a COPYING file in every sub-directory if the license is not GPLv2
> and it matches the license of a parent directory.
> 
> Do you plan to remove COPYING completely?

No, I don't plan to remove COPYING completely. COPYING is useful to tell
the user what license to choose. I only meant to clarify that COPYING
doesn't need to have a full copy of the license again. An SPDX tag would
be enough. I can change it to:

---
When creating new components and directories that contain a
significant amount of files that are licensed under licenses other
than GPLv2 or the license specified in the COPYING file, please
create a new COPYING file in that directory containing the SPDX tag
and a rationale for using a different license. This helps ensure that
the license of this new component/directory is maintained consistently
with the original intention.
---


> >     New files
> >   ---------
> >   -If specific files that differ from the license in a directory are
> > introduced,
> 
> This is fine to drop but ...
> 
> > -exceptions should be highlighted and discussed in the commit message or
> > cover
> > -letter introducing the file.
> 
> ... I think this should be kept because we want to have justification why the
> license of a file doesn't match the license of the directory.

Good idea


> > +New files should start with a single-line SPDX comment to express the
> > +license. The following comment and license are recommended:
> 
> Someone reading this may think that a new file in libxl wants to be GPLv2. So
> I would add in parentheses that the license may be different in some
> directory.
> 
> Similarly, I think this should be stronger than recommended. The SPDX should
> be a *must* and for the license there are effectively little leeway in which
> one we could use for existing components.
> So how about:
> 
> "For instance, if the file is GPLv2, the comment would look like:
> 
> /* SPDX-License-Identifier... */
> 
> The recommended license of a directory will depend on the COPYING file. If the
> new file is using a different license, this should be highlighted and
> discussed in the commit message or cover letter introducing the file.
> "
> 
> Cheers,
> 
> -- 
> Julien Grall
>