Merge branch 'mauro' into docs-mw

Mauro says:

That's the final series to complete the migration of documentation
build: it converts get_feat from Perl to Python.

V2 is technically identical to v1: the only difference is that it
now uses tools/lib/python/feat to store the library logic.

With that, no Sphinx in-kernel extensions use fork anymore to call
ancillary scripts: everything is now importing Python methods
directly from the libraries.

There's nothing special on this conversion: it is a direct translation,
almost bug-compatible with the original version (*).

(*) I did solve two or three caveats on patch 1.

Most of the complexity of the script relies at the logic to produce
ReST tables. I do have here on my internal scripts a (somewhat) generic
formatter for ReST tables in Python. I was tempted to convert the logic
to use it, but, as this could cause regressions, I opted to not do it
right now, mainly because the matrix table logic is complex. Also,
I'm tempted to modify a little bit the output there, but extra tests
are required to see if PDF output would work with complex tables (I
remember I had a problem with that in the past). So, I'm postponing
such extra cleanup.

2 files changed, 225 insertions, 641 deletions

diff --git a/tools/docs/get_feat.pl b/tools/docs/get_feat.pl
deleted file mode 100755
index d75e7c85dc85..000000000000
--- a/tools/docs/get_feat.pl
+++ /dev/null
@@ -1,641 +0,0 @@
-#!/usr/bin/env perl
-# SPDX-License-Identifier: GPL-2.0
-
-use strict;
-use Pod::Usage;
-use Getopt::Long;
-use File::Find;
-use Fcntl ':mode';
-use Cwd 'abs_path';
-
-my $help;
-my $man;
-my $debug;
-my $arch;
-my $feat;
-my $enable_fname;
-
-my $basename = abs_path($0);
-$basename =~ s,/[^/]+$,/,;
-
-my $prefix=$basename . "../../Documentation/features";
-
-# Used only at for full features output. The script will auto-adjust
-# such values for the minimal possible values
-my $status_size = 1;
-my $description_size = 1;
-
-GetOptions(
-	"debug|d+" => \$debug,
-	"dir=s" => \$prefix,
-	'help|?' => \$help,
-	'arch=s' => \$arch,
-	'feat=s' => \$feat,
-	'feature=s' => \$feat,
-	"enable-fname" => \$enable_fname,
-	man => \$man
-) or pod2usage(2);
-
-pod2usage(1) if $help;
-pod2usage(-exitstatus => 0, -verbose => 2) if $man;
-
-pod2usage(1) if (scalar @ARGV < 1 || @ARGV > 2);
-
-my ($cmd, $arg) = @ARGV;
-
-pod2usage(2) if ($cmd ne "current" && $cmd ne "rest" && $cmd ne "validate"
-		&& $cmd ne "ls" && $cmd ne "list");
-
-require Data::Dumper if ($debug);
-
-my %data;
-my %archs;
-
-#
-# Displays an error message, printing file name and line
-#
-sub parse_error($$$$) {
-	my ($file, $ln, $msg, $data) = @_;
-
-	$data =~ s/\s+$/\n/;
-
-	print STDERR "Warning: file $file#$ln:\n\t$msg";
-
-	if ($data ne "") {
-		print STDERR ". Line\n\t\t$data";
-	} else {
-	    print STDERR "\n";
-	}
-}
-
-#
-# Parse a features file, storing its contents at %data
-#
-
-my $h_name = "Feature";
-my $h_kconfig = "Kconfig";
-my $h_description = "Description";
-my $h_subsys = "Subsystem";
-my $h_status = "Status";
-my $h_arch = "Architecture";
-
-my $max_size_name = length($h_name);
-my $max_size_kconfig = length($h_kconfig);
-my $max_size_description = length($h_description);
-my $max_size_subsys = length($h_subsys);
-my $max_size_status = length($h_status);
-
-my $max_size_arch = 0;
-my $max_size_arch_with_header;
-my $max_description_word = 0;
-
-sub parse_feat {
-	my $file = $File::Find::name;
-
-	my $mode = (stat($file))[2];
-	return if ($mode & S_IFDIR);
-	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)/([^/]+).*,);
-
-	if (length($subsys) > $max_size_subsys) {
-		$max_size_subsys = length($subsys);
-	}
-
-	my $name;
-	my $kconfig;
-	my $description;
-	my $comments = "";
-	my $last_status;
-	my $ln;
-	my %arch_table;
-
-	print STDERR "Opening $file\n" if ($debug > 1);
-	open IN, $file;
-
-	while(<IN>) {
-		$ln++;
-
-		if (m/^\#\s+Feature\s+name:\s*(.*\S)/) {
-			$name = $1;
-			if (length($name) > $max_size_name) {
-				$max_size_name = length($name);
-			}
-			next;
-		}
-		if (m/^\#\s+Kconfig:\s*(.*\S)/) {
-			$kconfig = $1;
-			if (length($kconfig) > $max_size_kconfig) {
-				$max_size_kconfig = length($kconfig);
-			}
-			next;
-		}
-		if (m/^\#\s+description:\s*(.*\S)/) {
-			$description = $1;
-			if (length($description) > $max_size_description) {
-				$max_size_description = length($description);
-			}
-
-			foreach my $word (split /\s+/, $description) {
-				if (length($word) > $max_description_word) {
-					$max_description_word = length($word);
-				}
-			}
-
-			next;
-		}
-		next if (m/^\\s*$/);
-		next if (m/^\s*\-+\s*$/);
-		next if (m/^\s*\|\s*arch\s*\|\s*status\s*\|\s*$/);
-
-		if (m/^\#\s*(.*)/) {
-			$comments .= "$1\n";
-			next;
-		}
-		if (m/^\s*\|\s*(\S+):\s*\|\s*(\S+)\s*\|\s*$/) {
-			my $a = $1;
-			my $status = $2;
-
-			if (length($status) > $max_size_status) {
-				$max_size_status = length($status);
-			}
-			if (length($a) > $max_size_arch) {
-				$max_size_arch = length($a);
-			}
-
-			$status = "---" if ($status =~ m/^\.\.$/);
-
-			$archs{$a} = 1;
-			$arch_table{$a} = $status;
-			next;
-		}
-
-		#Everything else is an error
-		parse_error($file, $ln, "line is invalid", $_);
-	}
-	close IN;
-
-	if (!$name) {
-		parse_error($file, $ln, "Feature name not found", "");
-		return;
-	}
-
-	parse_error($file, $ln, "Subsystem not found", "") if (!$subsys);
-	parse_error($file, $ln, "Kconfig not found", "") if (!$kconfig);
-	parse_error($file, $ln, "Description not found", "") if (!$description);
-
-	if (!%arch_table) {
-		parse_error($file, $ln, "Architecture table not found", "");
-		return;
-	}
-
-	$data{$name}->{where} = $file;
-	$data{$name}->{subsys} = $subsys;
-	$data{$name}->{kconfig} = $kconfig;
-	$data{$name}->{description} = $description;
-	$data{$name}->{comments} = $comments;
-	$data{$name}->{table} = \%arch_table;
-
-	$max_size_arch_with_header = $max_size_arch + length($h_arch);
-}
-
-#
-# Output feature(s) for a given architecture
-#
-sub output_arch_table {
-	my $title = "Feature status on $arch architecture";
-
-	print "=" x length($title) . "\n";
-	print "$title\n";
-	print "=" x length($title) . "\n\n";
-
-	print "=" x $max_size_subsys;
-	print "  ";
-	print "=" x $max_size_name;
-	print "  ";
-	print "=" x $max_size_kconfig;
-	print "  ";
-	print "=" x $max_size_status;
-	print "  ";
-	print "=" x $max_size_description;
-	print "\n";
-	printf "%-${max_size_subsys}s  ", $h_subsys;
-	printf "%-${max_size_name}s  ", $h_name;
-	printf "%-${max_size_kconfig}s  ", $h_kconfig;
-	printf "%-${max_size_status}s  ", $h_status;
-	printf "%-${max_size_description}s\n", $h_description;
-	print "=" x $max_size_subsys;
-	print "  ";
-	print "=" x $max_size_name;
-	print "  ";
-	print "=" x $max_size_kconfig;
-	print "  ";
-	print "=" x $max_size_status;
-	print "  ";
-	print "=" x $max_size_description;
-	print "\n";
-
-	foreach my $name (sort {
-				($data{$a}->{subsys} cmp $data{$b}->{subsys}) ||
-				("\L$a" cmp "\L$b")
-			       } keys %data) {
-		next if ($feat && $name ne $feat);
-
-		my %arch_table = %{$data{$name}->{table}};
-		printf "%-${max_size_subsys}s  ", $data{$name}->{subsys};
-		printf "%-${max_size_name}s  ", $name;
-		printf "%-${max_size_kconfig}s  ", $data{$name}->{kconfig};
-		printf "%-${max_size_status}s  ", $arch_table{$arch};
-		printf "%-s\n", $data{$name}->{description};
-	}
-
-	print "=" x $max_size_subsys;
-	print "  ";
-	print "=" x $max_size_name;
-	print "  ";
-	print "=" x $max_size_kconfig;
-	print "  ";
-	print "=" x $max_size_status;
-	print "  ";
-	print "=" x $max_size_description;
-	print "\n";
-}
-
-#
-# list feature(s) for a given architecture
-#
-sub list_arch_features {
-	print "#\n# Kernel feature support matrix of the '$arch' architecture:\n#\n";
-
-	foreach my $name (sort {
-				($data{$a}->{subsys} cmp $data{$b}->{subsys}) ||
-				("\L$a" cmp "\L$b")
-			       } keys %data) {
-		next if ($feat && $name ne $feat);
-
-		my %arch_table = %{$data{$name}->{table}};
-
-		my $status = $arch_table{$arch};
-		$status = " " x ((4 - length($status)) / 2) . $status;
-
-		printf " %${max_size_subsys}s/ ", $data{$name}->{subsys};
-		printf "%-${max_size_name}s: ", $name;
-		printf "%-5s|   ", $status;
-		printf "%${max_size_kconfig}s # ", $data{$name}->{kconfig};
-		printf " %s\n", $data{$name}->{description};
-	}
-}
-
-#
-# Output a feature on all architectures
-#
-sub output_feature {
-	my $title = "Feature $feat";
-
-	print "=" x length($title) . "\n";
-	print "$title\n";
-	print "=" x length($title) . "\n\n";
-
-	print ":Subsystem: $data{$feat}->{subsys} \n" if ($data{$feat}->{subsys});
-	print ":Kconfig: $data{$feat}->{kconfig} \n" if ($data{$feat}->{kconfig});
-
-	my $desc = $data{$feat}->{description};
-	$desc =~ s/^([a-z])/\U$1/;
-	$desc =~ s/\.?\s*//;
-	print "\n$desc.\n\n";
-
-	my $com = $data{$feat}->{comments};
-	$com =~ s/^\s+//;
-	$com =~ s/\s+$//;
-	if ($com) {
-		print "Comments\n";
-		print "--------\n\n";
-		print "$com\n\n";
-	}
-
-	print "=" x $max_size_arch_with_header;
-	print "  ";
-	print "=" x $max_size_status;
-	print "\n";
-
-	printf "%-${max_size_arch}s  ", $h_arch;
-	printf "%-${max_size_status}s", $h_status . "\n";
-
-	print "=" x $max_size_arch_with_header;
-	print "  ";
-	print "=" x $max_size_status;
-	print "\n";
-
-	my %arch_table = %{$data{$feat}->{table}};
-	foreach my $arch (sort keys %arch_table) {
-		printf "%-${max_size_arch}s  ", $arch;
-		printf "%-${max_size_status}s\n", $arch_table{$arch};
-	}
-
-	print "=" x $max_size_arch_with_header;
-	print "  ";
-	print "=" x $max_size_status;
-	print "\n";
-}
-
-#
-# Output all features for all architectures
-#
-
-sub matrix_lines($$$) {
-	my $desc_size = shift;
-	my $status_size = shift;
-	my $header = shift;
-	my $fill;
-	my $ln_marker;
-
-	if ($header) {
-		$ln_marker = "=";
-	} else {
-		$ln_marker = "-";
-	}
-
-	$fill = $ln_marker;
-
-	print "+";
-	print $fill x $max_size_name;
-	print "+";
-	print $fill x $desc_size;
-	print "+";
-	print $ln_marker x $status_size;
-	print "+\n";
-}
-
-sub output_matrix {
-	my $title = "Feature status on all architectures";
-	my $notcompat = "Not compatible";
-
-	print "=" x length($title) . "\n";
-	print "$title\n";
-	print "=" x length($title) . "\n\n";
-
-	my $desc_title = "$h_kconfig / $h_description";
-
-	my $desc_size = $max_size_kconfig + 4;
-	if (!$description_size) {
-		$desc_size = $max_size_description if ($max_size_description > $desc_size);
-	} else {
-		$desc_size = $description_size if ($description_size > $desc_size);
-	}
-	$desc_size = $max_description_word if ($max_description_word > $desc_size);
-
-	$desc_size = length($desc_title) if (length($desc_title) > $desc_size);
-
-	$max_size_status = length($notcompat) if (length($notcompat) > $max_size_status);
-
-	# Ensure that the status will fit
-	my $min_status_size = $max_size_status + $max_size_arch + 6;
-	$status_size = $min_status_size if ($status_size < $min_status_size);
-
-
-	my $cur_subsys = "";
-	foreach my $name (sort {
-				($data{$a}->{subsys} cmp $data{$b}->{subsys}) or
-				("\L$a" cmp "\L$b")
-			       } keys %data) {
-
-		if ($cur_subsys ne $data{$name}->{subsys}) {
-			if ($cur_subsys ne "") {
-				printf "\n";
-			}
-
-			$cur_subsys = $data{$name}->{subsys};
-
-			my $title = "Subsystem: $cur_subsys";
-			print "$title\n";
-			print "=" x length($title) . "\n\n";
-
-
-			matrix_lines($desc_size, $status_size, 0);
-
-			printf "|%-${max_size_name}s", $h_name;
-			printf "|%-${desc_size}s", $desc_title;
-
-			printf "|%-${status_size}s|\n", "Status per architecture";
-			matrix_lines($desc_size, $status_size, 1);
-		}
-
-		my %arch_table = %{$data{$name}->{table}};
-		my $cur_status = "";
-
-		my (@lines, @descs);
-		my $line = "";
-		foreach my $arch (sort {
-					($arch_table{$b} cmp $arch_table{$a}) or
-					("\L$a" cmp "\L$b")
-				       } keys %arch_table) {
-
-			my $status = $arch_table{$arch};
-
-			if ($status eq "---") {
-				$status = $notcompat;
-			}
-
-			if ($status ne $cur_status) {
-				if ($line ne "") {
-					push @lines, $line;
-					$line = "";
-				}
-				$line = "- **" . $status . "**: " . $arch;
-			} elsif (length($line) + length ($arch) + 2 < $status_size) {
-				$line .= ", " . $arch;
-			} else {
-				push @lines, $line;
-				$line = "  " . $arch;
-			}
-			$cur_status = $status;
-		}
-		push @lines, $line if ($line ne "");
-
-		my $description = $data{$name}->{description};
-		while (length($description) > $desc_size) {
-			my $d = substr $description, 0, $desc_size;
-
-			# Ensure that it will end on a space
-			# if it can't, it means that the size is too small
-			# Instead of aborting it, let's print what we have
-			if (!($d =~ s/^(.*)\s+.*/$1/)) {
-				$d = substr $d, 0, -1;
-				push @descs, "$d\\";
-				$description =~ s/^\Q$d\E//;
-			} else {
-				push @descs, $d;
-				$description =~ s/^\Q$d\E\s+//;
-			}
-		}
-		push @descs, $description;
-
-		# Ensure that the full description will be printed
-		push @lines, "" while (scalar(@lines) < 2 + scalar(@descs));
-
-		my $ln = 0;
-		for my $line(@lines) {
-			if (!$ln) {
-				printf "|%-${max_size_name}s", $name;
-				printf "|%-${desc_size}s", "``" . $data{$name}->{kconfig} . "``";
-			} elsif ($ln >= 2 && scalar(@descs)) {
-				printf "|%-${max_size_name}s", "";
-				printf "|%-${desc_size}s", shift @descs;
-			} else {
-				printf "|%-${max_size_name}s", "";
-				printf "|%-${desc_size}s", "";
-			}
-
-			printf "|%-${status_size}s|\n", $line;
-
-			$ln++;
-		}
-		matrix_lines($desc_size, $status_size, 0);
-	}
-}
-
-
-#
-# Parses all feature files located at $prefix dir
-#
-find({wanted =>\&parse_feat, no_chdir => 1}, $prefix);
-
-print STDERR Data::Dumper->Dump([\%data], [qw(*data)]) if ($debug);
-
-#
-# Handles the command
-#
-if ($cmd eq "current") {
-	$arch = qx(uname -m | sed 's/x86_64/x86/' | sed 's/i386/x86/' | sed 's/s390x/s390/');
-	$arch =~s/\s+$//;
-}
-
-if ($cmd eq "ls" or $cmd eq "list") {
-	if (!$arch) {
-		$arch = qx(uname -m | sed 's/x86_64/x86/' | sed 's/i386/x86/' | sed 's/s390x/s390/');
-		$arch =~s/\s+$//;
-	}
-
-	list_arch_features;
-
-	exit;
-}
-
-if ($cmd ne "validate") {
-	if ($arch) {
-		output_arch_table;
-	} elsif ($feat) {
-		output_feature;
-	} else {
-		output_matrix;
-	}
-}
-
-__END__
-
-=head1 NAME
-
-get_feat.pl - parse the Linux Feature files and produce a ReST book.
-
-=head1 SYNOPSIS
-
-B<get_feat.pl> [--debug] [--man] [--help] [--dir=<dir>] [--arch=<arch>]
-	       [--feature=<feature>|--feat=<feature>] <COMAND> [<ARGUMENT>]
-
-Where <COMMAND> can be:
-
-=over 8
-
-B<current>               - output table in ReST compatible ASCII format
-			   with features for this machine's architecture
-
-B<rest>                  - output table(s)  in ReST compatible ASCII format
-			   with features in ReST markup language. The output
-			   is affected by --arch or --feat/--feature flags.
-
-B<validate>              - validate the contents of the files under
-			   Documentation/features.
-
-B<ls> or B<list>         - list features for this machine's architecture,
-			   using an easier to parse format.
-			   The output is affected by --arch flag.
-
-=back
-
-=head1 OPTIONS
-
-=over 8
-
-=item B<--arch>
-
-Output features for an specific architecture, optionally filtering for
-a single specific feature.
-
-=item B<--feat> or B<--feature>
-
-Output features for a single specific feature.
-
-=item B<--dir>
-
-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
-times, to increase verbosity.
-
-=item B<--help>
-
-Prints a brief help message and exits.
-
-=item B<--man>
-
-Prints the manual page and exits.
-
-=back
-
-=head1 DESCRIPTION
-
-Parse the Linux feature files from Documentation/features (by default),
-optionally producing results at ReST format.
-
-It supports output data per architecture, per feature or a
-feature x arch matrix.
-
-When used with B<rest> command, it will use either one of the tree formats:
-
-If neither B<--arch> or B<--feature> arguments are used, it will output a
-matrix with features per architecture.
-
-If B<--arch> argument is used, it will output the features availability for
-a given architecture.
-
-If B<--feat> argument is used, it will output the content of the feature
-file using ReStructured Text markup.
-
-=head1 BUGS
-
-Report bugs to Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
-
-=head1 COPYRIGHT
-
-Copyright (c) 2019 by Mauro Carvalho Chehab <mchehab+samsung@kernel.org>.
-
-License GPLv2: GNU GPL version 2 <http://gnu.org/licenses/gpl.html>.
-
-This is free software: you are free to change and redistribute it.
-There is NO WARRANTY, to the extent permitted by law.
-
-=cut
diff --git a/tools/docs/get_feat.py b/tools/docs/get_feat.py
new file mode 100755
index 000000000000..2b5155a1f134
--- /dev/null
+++ b/tools/docs/get_feat.py
@@ -0,0 +1,225 @@
+#!/usr/bin/env python3
+# pylint: disable=R0902,R0911,R0912,R0914,R0915
+# Copyright(c) 2025: Mauro Carvalho Chehab <mchehab@kernel.org>.
+# SPDX-License-Identifier: GPL-2.0
+
+
+"""
+Parse the Linux Feature files and produce a ReST book.
+"""
+
+import argparse
+import os
+import subprocess
+import sys
+
+from pprint import pprint
+
+LIB_DIR = "../../tools/lib/python"
+SRC_DIR = os.path.dirname(os.path.realpath(__file__))
+
+sys.path.insert(0, os.path.join(SRC_DIR, LIB_DIR))
+
+from feat.parse_features import ParseFeature                # pylint: disable=C0413
+
+SRCTREE = os.path.join(os.path.dirname(os.path.realpath(__file__)), "../..")
+DEFAULT_DIR = "Documentation/features"
+
+
+class GetFeature:
+    """Helper class to parse feature parsing parameters"""
+
+    @staticmethod
+    def get_current_arch():
+        """Detects the current architecture"""
+
+        proc = subprocess.run(["uname", "-m"], check=True,
+                              capture_output=True, text=True)
+
+        arch = proc.stdout.strip()
+        if arch in ["x86_64", "i386"]:
+            arch = "x86"
+        elif arch == "s390x":
+            arch = "s390"
+
+        return arch
+
+    def run_parser(self, args):
+        """Execute the feature parser"""
+
+        feat = ParseFeature(args.directory, args.debug, args.enable_fname)
+        data = feat.parse()
+
+        if args.debug > 2:
+            pprint(data)
+
+        return feat
+
+    def run_rest(self, args):
+        """
+        Generate tables in ReST format. Three types of tables are
+        supported, depending on the calling arguments:
+
+        - neither feature nor arch is passed: generates a full matrix;
+        - arch provided: generates a table of supported tables for the
+          guiven architecture, eventually filtered by feature;
+        - only feature provided: generates a table with feature details,
+          showing what architectures it is implemented.
+        """
+
+        feat = self.run_parser(args)
+
+        if args.arch:
+            rst = feat.output_arch_table(args.arch, args.feat)
+        elif args.feat:
+            rst = feat.output_feature(args.feat)
+        else:
+            rst = feat.output_matrix()
+
+        print(rst)
+
+    def run_current(self, args):
+        """
+        Instead of using a --arch parameter, get feature for the current
+        architecture.
+        """
+
+        args.arch = self.get_current_arch()
+
+        self.run_rest(args)
+
+    def run_list(self, args):
+        """
+        Generate a list of features for a given architecture, in a format
+        parseable by other scripts. The output format is not ReST.
+        """
+
+        if not args.arch:
+            args.arch = self.get_current_arch()
+
+        feat = self.run_parser(args)
+        msg = feat.list_arch_features(args.arch, args.feat)
+
+        print(msg)
+
+    def parse_arch(self, parser):
+        """Add a --arch parsing argument"""
+
+        parser.add_argument("--arch",
+                            help="Output features for an specific"
+                                 " architecture, optionally filtering for a "
+                                 "single specific feature.")
+
+    def parse_feat(self, parser):
+        """Add a --feat parsing argument"""
+
+        parser.add_argument("--feat", "--feature",
+                            help="Output features for a single specific "
+                                  "feature.")
+
+
+    def current_args(self, subparsers):
+        """Implementscurrent argparse subparser"""
+
+        parser = subparsers.add_parser("current",
+                                       formatter_class=argparse.RawTextHelpFormatter,
+                                       description="Output table in ReST "
+                                                   "compatible ASCII format "
+                                                   "with features for this "
+                                                   "machine's architecture")
+
+        self.parse_feat(parser)
+        parser.set_defaults(func=self.run_current)
+
+    def rest_args(self, subparsers):
+        """Implement rest argparse subparser"""
+
+        parser = subparsers.add_parser("rest",
+                                       formatter_class=argparse.RawTextHelpFormatter,
+                                       description="Output table(s) in ReST "
+                                                   "compatible ASCII format "
+                                                   "with features in ReST "
+                                                   "markup language. The "
+                                                   "output is affected by "
+                                                   "--arch or --feat/--feature"
+                                                   " flags.")
+
+        self.parse_arch(parser)
+        self.parse_feat(parser)
+        parser.set_defaults(func=self.run_rest)
+
+    def list_args(self, subparsers):
+        """Implement list argparse subparser"""
+
+        parser = subparsers.add_parser("list",
+                                       formatter_class=argparse.RawTextHelpFormatter,
+                                       description="List features for this "
+                                                   "machine's architecture, "
+                                                   "using an easier to parse "
+                                                   "format. The output is "
+                                                   "affected by --arch flag.")
+
+        self.parse_arch(parser)
+        self.parse_feat(parser)
+        parser.set_defaults(func=self.run_list)
+
+    def validate_args(self, subparsers):
+        """Implement validate argparse subparser"""
+
+        parser = subparsers.add_parser("validate",
+                                       formatter_class=argparse.RawTextHelpFormatter,
+                                       description="Validate the contents of "
+                                                   "the files under "
+                                                   f"{DEFAULT_DIR}.")
+
+        parser.set_defaults(func=self.run_parser)
+
+    def parser(self):
+        """
+        Create an arparse with common options and several subparsers
+        """
+        parser = argparse.ArgumentParser(formatter_class=argparse.RawTextHelpFormatter)
+
+        parser.add_argument("-d", "--debug", action="count", default=0,
+                            help="Put the script in verbose mode, useful for "
+                                 "debugging. Can be called multiple times, to "
+                                 "increase verbosity.")
+
+        parser.add_argument("--directory", "--dir", default=DEFAULT_DIR,
+                            help="Changes the location of the Feature files. "
+                                 f"By default, it uses the {DEFAULT_DIR} "
+                                 "directory.")
+
+        parser.add_argument("--enable-fname", action="store_true",
+                            help="Prints the file name of the feature files. "
+                                 "This can be used in order to track "
+                                 "dependencies during documentation build.")
+
+        subparsers = parser.add_subparsers()
+
+        self.current_args(subparsers)
+        self.rest_args(subparsers)
+        self.list_args(subparsers)
+        self.validate_args(subparsers)
+
+        args = parser.parse_args()
+
+        return args
+
+
+def main():
+    """Main program"""
+
+    feat = GetFeature()
+
+    args = feat.parser()
+
+    if "func" in args:
+        args.func(args)
+    else:
+        sys.exit(f"Please specify a valid command for {sys.argv[0]}")
+
+
+# Call main method
+if __name__ == "__main__":
+    main()