Re: [PATCH] checkpatch: Ignore removed lines in license check

["Daniel P. Berrangé" <berrange@redhat.com>]

On Wed, Sep 17, 2025 at 09:17:57AM -0700, Nabih Estefan wrote:
> On Wed, Sep 17, 2025 at 9:05 AM Daniel P. Berrangé <berrange@redhat.com> wrote:
> >
> > On Wed, Sep 17, 2025 at 08:16:53AM -0700, Nabih Estefan wrote:
> > > We ran it against an internal patch that we were updating, so I can't
> > > show you the patch.
> >
> > If you can't share that private patch, perhaps you can create a
> > dummy patch with the same type of diff structure that shows the
> > problem ?
> >
> The patch looks something like the following:

snip

> It's just changing the file from an invalid  to a valid one, nothing else is
> being done, which is why I'm confused how it's triggering this.

Ahhh, I was getting confused about which SPDX check was being
triggered.

The one that runs against "new" files only is a check for the
existence of a SPDX tag.

The one that runs against all files is a check for the declared
license check.

So yes, your patch here is correct & required so

  Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>


> 
> > > However, the difference on it being affected might be in how we're
> > > running it? To check
> > > against just the changes being done in the specific patch, instead of
> > > the whole file, we
> > > trigger it by running `./scripts/checkpatch.pl --branch HEAD...HEAD^`.
> > > Could that be
> > > why it's triggering against existing files?
> >
> > I don't think that's a problem. It is just a different way ot getting
> > a list of git commit hashes to analyse - it'll still operate against
> > a patch diff IIUC.
> >
> > FWIW, I use   'checkpatch.pl master..' and/or 'git show| checkpatch.pl -'
> >
> > >
> > > Thanks,
> > > Nabih
> > >
> > > On Wed, Sep 17, 2025 at 2:24 AM Daniel P. Berrangé <berrange@redhat.com> wrote:
> > > >
> > > > On Tue, Sep 16, 2025 at 04:59:28PM +0000, Nabih Estefan wrote:
> > > > > When running the license check, if we are updating a license it is
> > > > > possible for the checkpatch script to test against old license lines
> > > > > instead of newer ones, since the removal lines appear before the
> > > > > addition lines in a .patch file.
> > > >
> > > > While we match the "SPDX-License-Identifier" text in any context,
> > > > the "file must have SDPX" validation is only performed against
> > > > files that are entirely new:
> > > >
> > > >   # Called at the end of processing a diff hunk for a file
> > > >   sub process_end_of_file {
> > > >         my $fileinfo = shift;
> > > >
> > > >         if ($fileinfo->{action} eq "new" &&
> > > >             !exists $fileinfo->{facts}->{sawspdx}) {
> > > >              ...raise error ....
> > > >
> > > > > Fix this by skipping over lines that start with "-" in the checkpatch
> > > > > script.
> > > >
> > > > A new file cannot have any "-" lines present, so there isn't any
> > > > bug that needs fixing AFAICT.  Can you show any patch or commit
> > > > where this would have made a difference to what checkpatch.pl
> > > > reports ?
> > > >
> > > > >
> > > > > Signed-off-by: Nabih Estefan <nabihestefan@google.com>
> > > > > ---
> > > > >  scripts/checkpatch.pl | 3 ++-
> > > > >  1 file changed, 2 insertions(+), 1 deletion(-)
> > > > >
> > > > > diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
> > > > > index 833f20f555..c57a423f9f 100755
> > > > > --- a/scripts/checkpatch.pl
> > > > > +++ b/scripts/checkpatch.pl
> > > > > @@ -1813,7 +1813,8 @@ sub process {
> > > > >               }
> > > > >
> > > > >  # Check SPDX-License-Identifier references a permitted license
> > > > > -             if ($rawline =~ m,SPDX-License-Identifier: (.*?)(\*/)?\s*$,) {
> > > > > +             if (($rawline =~ m,SPDX-License-Identifier: (.*?)(\*/)?\s*$,) &&
> > > > > +                     $rawline !~ /^-/) {
> > > > >                       $fileinfo->{facts}->{sawspdx} = 1;
> > > > >                       &checkspdx($realfile, $1);
> > > > >               }
> > > > > --
> > > > > 2.51.0.384.g4c02a37b29-goog
> > > > >
> > > >
> > > > With regards,
> > > > Daniel
> > > > --
> > > > |: https://berrange.com      -o-    https://www.flickr.com/photos/dberrange :|
> > > > |: https://libvirt.org         -o-            https://fstop138.berrange.com :|
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> > > >
> > >
> >
> > With regards,
> > Daniel
> > --
> > |: https://berrange.com      -o-    https://www.flickr.com/photos/dberrange :|
> > |: https://libvirt.org         -o-            https://fstop138.berrange.com :|
> > |: https://entangle-photo.org    -o-    https://www.instagram.com/dberrange :|
> >
> 

With regards,
Daniel
-- 
|: https://berrange.com      -o-    https://www.flickr.com/photos/dberrange :|
|: https://libvirt.org         -o-            https://fstop138.berrange.com :|
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