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Subject: Re: [RFC v3] scripts: kernel-doc: reduce repeated regex expressions
 into variables
To:     Matthew Wilcox <willy@infradead.org>
Cc:     corbet@lwn.net, lukas.bulwahn@gmail.com,
        linux-kernel-mentees@lists.linuxfoundation.org,
        linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org
References: <20210427165633.GA235567@casper.infradead.org>
 <20210429063729.8144-1-yashsri421@gmail.com>
 <20210501154336.GS1847222@casper.infradead.org>
From:   Aditya Srivastava <yashsri421@gmail.com>
Message-ID: <490cdb39-74a1-951a-0688-0f72f58ae7f8@gmail.com>
Date:   Fri, 14 May 2021 21:47:27 +0530
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On 1/5/21 9:13 pm, Matthew Wilcox wrote:
> On Thu, Apr 29, 2021 at 12:07:29PM +0530, Aditya Srivastava wrote:
>> +    my $name = qr{[a-zA-Z0-9_~:]+};
>> +    my $prototype_end1 = qr{[^\(]*};
>> +    my $prototype_end2 = qr{[^\{]*};
>> +    my $prototype_end = qr{\(($prototype_end1|$prototype_end2)\)};
> 
> Would this be better written as:
> 
> 	my $prototype_end = qr{\([^\(\{]*\)}
> 

Hi Matthew
I have actually tried this earlier, but it does not work as expected,
probably because of greedy matching. I have produced the list of
warning differences before and after over the files, when using this
regex:
https://github.com/AdityaSrivast/kernel-tasks/blob/master/random/kernel-doc/diff_on_alt_protend


> And now that I look at the whole thing, doesn't this fail to parse
> a function declared as:
> 
> int f(void (*g)(long));
> 
> (that is, f takes a single argument, which is a pointer to a function
> which takes a long argument and returns void)
> 

I think this will match against:
$prototype =~ m/^($type1)\s+($name)\s*$prototype_end/

Thanks
Aditya