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From:   Antonio Borneo <borneo.antonio@gmail.com>
Date:   Thu, 9 May 2019 11:26:50 +0200
Message-ID: <CAAj6DX3aZ+_q1Vi7A+fyje9-s27dYO5_MEhZ_EU-DEVSXwNzkw@mail.gmail.com>
Subject: Re: [PATCH v4] checkpatch: add command-line option for TAB size
To:     Joe Perches <joe@perches.com>
Cc:     Andy Whitcroft <apw@canonical.com>,
        "Elliott, Robert (Servers)" <elliott@hpe.com>,
        linux-kernel@vger.kernel.org
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On Thu, May 9, 2019 at 10:03 AM Joe Perches <joe@perches.com> wrote:
>
> On Thu, 2019-05-09 at 09:21 +0200, Antonio Borneo wrote:
> > diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
> []
> > @@ -2224,7 +2229,7 @@ sub string_find_replace {
> >  sub tabify {
> >       my ($leading) = @_;
> >
> > -     my $source_indent = 8;
> > +     my $source_indent = $tabsize;
> >       my $max_spaces_before_tab = $source_indent - 1;
>
> I didn't test this.
>
> Does this work properly if --tab-size=1 ?
> Maybe die if ($tabsize < 2); is necessary?

I have tested it and it works fine, but now that you point it, I
rechecked the code. There is already this in checkpatch
sub tabify {
...
        my $source_indent = $tabsize;
        my $max_spaces_before_tab = $source_indent - 1;
...
        #Remove spaces before a tab
        1 while $leading =~ s@^([\t]*)( {1,$max_spaces_before_tab})\t@$1\t@g;
that works fine.
But we could have in the future some other test in checkpatch that
uses "$tabsize - 1" and does not get the proper validation for
--tab-size=1
Maybe it's safer to put die if ($tabsize < 2) right now, and avoid
future headaches. With a comment to explains this choice.

Antonio