Re: [PATCH 21/27] kbuild, dma-mapping: benchmark: remove MODULE_LICENSE in non-modules

[Luis Chamberlain]

On Wed, Feb 22, 2023 at 03:48:56PM +0100, Christoph Hellwig wrote:
> Looks good:
> 
> Reviewed-by: Christoph Hellwig <hch@xxxxxx>
> 
> On Wed, Feb 22, 2023 at 12:14:47PM +0000, Nick Alcock wrote:
> > Since commit 8b41fc4454e ("kbuild: create modules.builtin without
> > Makefile.modbuiltin or tristate.conf"), MODULE_LICENSE declarations
> > are used to identify modules.
> 
> .. but this seems like a really odd design.  How is this going to
> continue working once we can autogenerate the module license section
> from the SPDX tags, which we eventually really should?

Yes I totally agree we should. But I think we should take this by steps.
First, we ensure we have only MODULE_LICENSE() macros upstream on things which
are really possible modules, ie we remove the false positives. We then put a
stop-gap script which can complain if it finds new usecases which are buggy.

Then we look for an optimal way to address the final step:

 * remove all MODULE_LICENSE() and autogenerate them from SPDX

The difficulty in this will be that we want to upkeep existing build
heuristics and avoid to have to traverse the tree twice (see details
on commit 8b41fc4454e). I can't think of an easy way to do this that
does not involve using kconfig tristate somehow. This is a bit of
tricky homework we have. Perhaps Masahiro can come up with something
clever.

  Luis