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From:   Lukas Bulwahn <lukas.bulwahn@gmail.com>
Date:   Sat, 6 Mar 2021 07:38:39 +0100
Message-ID: <CAKXUXMwoYa6xbCsqnUYL5uSA71h_3xV7-8erF6XTpmkck8ozaw@mail.gmail.com>
Subject: Re: [RFC] scripts: kernel-doc: fix attribute capture in function parsing
To:     Aditya <yashsri421@gmail.com>
Cc:     Matthew Wilcox <willy@infradead.org>,
        Jonathan Corbet <corbet@lwn.net>,
        "open list:DOCUMENTATION" <linux-doc@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        linux-kernel-mentees@lists.linuxfoundation.org
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On Fri, Mar 5, 2021 at 8:38 PM Aditya <yashsri421@gmail.com> wrote:
>
> On 6/3/21 12:13 am, Matthew Wilcox wrote:
> > On Fri, Mar 05, 2021 at 11:50:00PM +0530, Aditya Srivastava wrote:
> >> Provide a simple fix by adding "__attribute_const__" in the corresponding
> >> regex expression.
> >>
> >> A quick evaluation by running 'kernel-doc -none' on kernel-tree reveals
> >> that no additional warning or error has been added or removed by the fix.
> >
> > I'm no perlmonger, but why isn't this simply:
> >
> > +++ b/scripts/kernel-doc
> > @@ -1753,6 +1753,7 @@ sub dump_function($$) {
> >      $prototype =~ s/^__inline +//;
> >      $prototype =~ s/^__always_inline +//;
> >      $prototype =~ s/^noinline +//;
> > +    $prototype =~ s/__attribute_const__ +//;
> >      $prototype =~ s/__init +//;
> >      $prototype =~ s/__init_or_module +//;
> >      $prototype =~ s/__meminit +//;
> >
> > (completely untested)
> >
> >> +++ b/scripts/kernel-doc
> >> @@ -1753,6 +1753,7 @@ sub dump_function($$) {
> >>      my $prototype = shift;
> >>      my $file = shift;
> >>      my $noret = 0;
> >> +    my $attribute_const = qr{__attribute_const__};
> >>
> >>      print_lineno($new_start_line);
> >>
> >> @@ -1808,7 +1809,7 @@ sub dump_function($$) {
> >>      $prototype =~ m/^(\w+)\s+([a-zA-Z0-9_~:]+)\s*\(([^\(]*)\)/ ||
> >>      $prototype =~ m/^(\w+\s*\*+)\s*([a-zA-Z0-9_~:]+)\s*\(([^\(]*)\)/ ||
> >>      $prototype =~ m/^(\w+\s+\w+)\s+([a-zA-Z0-9_~:]+)\s*\(([^\(]*)\)/ ||
> >> -    $prototype =~ m/^(\w+\s+\w+\s*\*+)\s*([a-zA-Z0-9_~:]+)\s*\(([^\(]*)\)/ ||
> >> +    $prototype =~ m/^(\w+\s+\w+\s*\*+$attribute_const?)\s*([a-zA-Z0-9_~:]+)\s*\(([^\(]*)\)/ ||
> >>      $prototype =~ m/^(\w+\s+\w+\s+\w+)\s+([a-zA-Z0-9_~:]+)\s*\(([^\(]*)\)/ ||
> >>      $prototype =~ m/^(\w+\s+\w+\s+\w+\s*\*+)\s*([a-zA-Z0-9_~:]+)\s*\(([^\(]*)\)/ ||
> >>      $prototype =~ m/^()([a-zA-Z0-9_~:]+)\s*\(([^\{]*)\)/ ||
>
> Hi Matthew
> You are correct, it should be placed there. I was considering it as a
> return type instead.
> I'll send a modified v2 with the changes.
>

Aditya, I also ran:

git ls-files | xargs ./scripts/kernel-doc -none 2>&1 | tee kernel-doc-output

cat kernel-doc-output | grep "cannot understand function prototype:" |
sed 's/[^:].*:[0-9]*: \(.*\)$/\1/' | sort

and I found another instance of failed parsing function prototypes in
mm/percpu.c:2671:

struct pcpu_alloc_info * __flatten pcpu_build_alloc_info(size_t
reserved_size, size_t dyn_size, size_t atom_size,
pcpu_fc_cpu_distance_fn_t cpu_distance_fn)

Could you address that one in your patch as well?

Lukas