scripts/get_feat.pl: allow output the parsed file names

Such output could be helpful while debugging it, but its main
goal is to tell kernel_feat.py about what files were used
by the script. Thie way, kernel_feat.py can add those as
documentation dependencies.

Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Link: https://lore.kernel.org/r/11b438ee01e00c866f5ea197d6aecc26e9f86945.1648290305.git.mchehab@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Author: mchehab

scripts/get_feat.pl

@@ -13,6 +13,7 @@
 my $debug;
 my $arch;
 my $feat;
+my $enable_fname;
 
 my $basename = abs_path($0);
 $basename =~ s,/[^/]+$,/,;
@@ -31,6 +32,7 @@
 	'arch=s' => \$arch,
 	'feat=s' => \$feat,
 	'feature=s' => \$feat,
+	"enable-fname" => \$enable_fname,
 	man => \$man
 ) or pod2usage(2);
 
@@ -95,6 +97,10 @@ sub parse_feat {
 	return if ($file =~ m,($prefix)/arch-support.txt,);
 	return if (!($file =~ m,arch-support.txt$,));
 
+	if ($enable_fname) {
+		printf ".. FILE %s\n", abs_path($file);
+	}
+
 	my $subsys = "";
 	$subsys = $2 if ( m,.*($prefix)/([^/]+).*,);
 
@@ -580,6 +586,11 @@ =head1 OPTIONS
 Changes the location of the Feature files. By default, it uses
 the Documentation/features directory.
 
+=item B<--enable-fname>
+
+Prints the file name of the feature files. This can be used in order to
+track dependencies during documentation build.
+
 =item B<--debug>
 
 Put the script in verbose mode, useful for debugging. Can be called multiple