Re: [PATCH v2 phy-next 24/24] MAINTAINERS: add regexes for linux-phy

[Joe Perches <joe@perches.com>]

On Sun, 2026-03-08 at 22:56 +0200, Vladimir Oltean wrote:
> On Sun, Mar 08, 2026 at 12:25:32PM -0700, Joe Perches wrote:
> > On Sun, 2026-03-08 at 21:10 +0200, Vladimir Oltean wrote:
> On Sun, Mar 08, 2026 at 11:40:44AM -0700, Joe Perches wrote:
> > > Perhaps if matching only the include uses:
> > > > (/ is escaped because get_maintainer is stupid)
> > > > something like:
> > > > 
> > > > K:	include\s*\<linux\/phy\/phy(?:-common-props|-provider)?\.h\>
> 
> > > Why is get_maintainer stupid?
> > 
> > The get_maintainer code used to match keywords is
> > 
> 	    foreach my $line (keys %keyword_hash) {
> 		if ($text =~ m/$keyword_hash{$line}/x) {
> > 
> > so it seems the first / in the K: <foo> regex would terminate
> > the match.
> > 
> > It might have been better to use a different delimiter.
> > Maybe:
> > 
> 		if ($text =~ m{$keyword_hash{$line}}/x
> 
> So why does it match in my example?

Not sure really.  But it does match exactly.
Maybe the regex code scans forward until the last /
as the / character is not a "real" metacharacter.

I added some test code and it produced:

line:	<+#include <linux/phy/phy.h>>
kw:	<(?:linux/phy/phy\.h|phy-props\.h|phy-provider\.h)>
test:	<^[+-].*(?:linux/phy/phy\.h|phy-props\.h|phy-provider\.h)>
match:	<+#include <linux/phy/phy.h>

From https://perldoc.perl.org/perlrequick

Not all characters can be used 'as is' in a match.
Some characters, called metacharacters, are considered special,
and reserved for use in regex notation. The metacharacters are

{}[]()^$.|*+?\

A metacharacter can be matched literally by putting a backslash before it:

"2+2=4" =~ /2+2/;    # doesn't match, + is a metacharacter
"2+2=4" =~ /2\+2/;   # matches, \+ is treated like an ordinary +
'C:\WIN32' =~ /C:\\WIN/;                       # matches
"/usr/bin/perl" =~ /\/usr\/bin\/perl/;  # matches

In the last regex, the forward slash '/' is also backslashed, because it is used to delimit the regex.