On Tue, 14 Jul 2020, Mrinal Pandey wrote:
>
>
> On Tue, Jul 14, 2020 at 1:16 AM Lukas Bulwahn <lukas.bulwahn@gmail.com> wrote:
>
>
> On Mon, 13 Jul 2020, Mrinal Pandey wrote:
>
> > In all the scripts, the SPDX license should be on the second line,
> > the first line being the "sh-bang", but checkpatch issues a warning
> > "Misplaced SPDX-License-Identifier tag - use line 1 instead" for the
> > scripts that have SPDX license in the second line.
> >
> > However, this warning is not issued when checkpatch is run on a file using
> > `-f` option. The case for files has been handled gracefully by changing
> > `$checklicenseline` to `2` but a corresponding check when running checkpatch
> > on a commit hash is missing.
> >
> > I noticed this false positive while running checkpatch on the set of
> > commits from v5.7 to v5.8-rc1 of the kernel on the commits which modified
> > a script file.
> >
> > This check is missing in checkpatch since commit a8da38a9cf0e
> > ("checkpatch: add test for SPDX-License-Identifier on wrong line #")
> > when the corresponding rule was first commited.
> >
> > Fix this by setting `$checklicenseline` to `2` when the diff content that
> > is being checked originates from a script, thus, informing checkpatch that
> > the SPDX license should be on the second line.
> >
> > Signed-off-by: Mrinal Pandey <mrinalmni@gmail.com>
> > ---
> > scripts/checkpatch.pl | 3 +++
> > 1 file changed, 3 insertions(+)
> >
> > diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
> > index 4c820607540b..bbffd0c4449d 100755
> > --- a/scripts/checkpatch.pl
> > +++ b/scripts/checkpatch.pl
> > @@ -3218,6 +3218,9 @@ sub process {
> > next if ($realfile !~ /\.(h|c|s|S|sh|dtsi|dts)$/);
> >
> > # check for using SPDX-License-Identifier on the wrong line number
> > + if ($realfile =~ /^scripts/) {
> > + $checklicenseline = 2;
> > + }
>
> I think this is somehow wrong here. The check for checklicenseline = 2
> looks very different above.
>
> Why does -f work and using a patch file not work?
>
>
> Sir,
>
> I am going to explain my observation based on file `scripts/atomic/gen-atomic-fallback.sh` and
> commit hash `37f8173dd849`.
>
> If we are checking against the file, `checklicenseline` is set to 1 and when `realline` is 1 the above
> `if` block is triggered, then we check if this line is of the form `#!/` using the regular expression
> `^[ \+]\s*\#\!\s*\/`. If this is the case we set `checklicenseline` to `2` informing checkpatch that it should
> expect license on the second line and this works all fine for a file.
> The `if` block below my proposed changes evaluates to false in this case and thus it emits no false warning.
>
> However, If we are checking a diff content, the above `if` block is not triggered at all. This is
> because `realline` stores the actual line number of the line we are checking currently out of diff content.
> This value is 2 because SPDX identifier is indeed at the second line in the file but `checklicenseline` is still
> `1`.
> `realline` will never become equal to 1 again and thus the above `if` condition will never be true in this case.
> Even if the above `if` block is triggered it would not update `checklicenseline` to 2 as the regular expression
> is not satisfied since we don't have sh-bang in diff content and just the SPDX tag.
> If we don't do this, the `if` block below evaluates to true when `realline` is 2 and `checklicensline` is `1`
> leading
> to the emission of a false warning.
>
So, maybe this whole logic needs to be reworked. If you do not know the
first line, you need to have a different criteria in the first place
to determine if you expect the license tag in the first or the second,
e.g., the file extension, and then checking line 1 for a shebang is just
sanity checking. If it is of a specific file extension, you know line 1
and it is not a shebang, that is probably worth noting as a different
recommendation in checkpatch.pl anyway.
Sir,
When we know the first line, i.e. we are running checkpatch against a file, the existing logic
works fine. We probably don't want to induce any changes there.
But when we don't know the first line, if am not wrong, it would go somewhat like:
if (the file is a script) {
if (the first line is shebang) {
if (the second line is SPDX) {
All good
} else {
Issue a misplaced or missing SPDX tag warning
}
} else {
Issue a missing shebang warning
}
} else {
if (the first line is SPDX) {
All good
} else {
Issue a misplaced or missing SPDX tag warning
}
}
Lukas
> So, what I did was to check if the diff content we are checking actually comes from a script, if yes, we can set
> `checklicenseline` to `2` to avoid this confusion.
>
Why would you think that scripts are only in scripts?
How about first listing all files where the SPDX tag is in line 2 in the
current repository, e.g., v5.8-rc5?
Then, we look at that list and determine a suitable criteria for looking
in line 2 for the SPDX tag.
Yes, the scripts are not only in scripts. I have listed all the files where the SPDX tag should be
on the second line. I've attached the list for reference. We should probably be checking the file
extension to determine if the tag needs to be on the second line or not.
The documentation says the SPDX tag should be present in all source files. Do these source files include
Documentation files too?
Thank you.
Lukas
> Please let me know if this is reasonable.
>
> Thank you.
>
>
> Lukas
>
>
> > if ($realline != $checklicenseline &&
> > $rawline =~ /\bSPDX-License-Identifier:/ &&
> > substr($line, @-, @+ - @-) eq "$;" x (@+ - @-)) {
> > --
> > 2.25.1
> >
> >
>
>
>