#!/usr/bin/env perl
# SPDX-License-Identifier: GPL-2.0
use strict;
use warnings;
use utf8;
use Pod::Usage;
use Getopt::Long;
use File::Find;
use Fcntl ':mode';
use Cwd 'abs_path';
my $help = 0;
my $hint = 0;
my $man = 0;
my $debug = 0;
my $enable_lineno = 0;
my $show_warnings = 1;
my $prefix="Documentation/ABI";
my $sysfs_prefix="/sys";
my $search_string;
#
# If true, assumes that the description is formatted with ReST
#
my $description_is_rst = 1;
GetOptions(
"debug|d+" => \$debug,
"enable-lineno" => \$enable_lineno,
"rst-source!" => \$description_is_rst,
"dir=s" => \$prefix,
'help|?' => \$help,
"show-hints" => \$hint,
"search-string=s" => \$search_string,
man => \$man
) or pod2usage(2);
pod2usage(1) if $help;
pod2usage(-exitstatus => 0, -verbose => 2) if $man;
pod2usage(2) if (scalar @ARGV < 1 || @ARGV > 2);
my ($cmd, $arg) = @ARGV;
pod2usage(2) if ($cmd ne "search" && $cmd ne "rest" && $cmd ne "validate" && $cmd ne "undefined");
pod2usage(2) if ($cmd eq "search" && !$arg);
require Data::Dumper if ($debug);
my %data;
my %symbols;
#
# Displays an error message, printing file name and line
#
sub parse_error($$$$) {
my ($file, $ln, $msg, $data) = @_;
return if (!$show_warnings);
$data =~ s/\s+$/\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 an ABI file, storing its contents at %data
#
sub parse_abi {
my $file = $File::Find::name;
my $mode = (stat($file))[2];
return if ($mode & S_IFDIR);
return if ($file =~ m,/README,);
my $name = $file;
$name =~ s,.*/,,;
my $fn = $file;
$fn =~ s,Documentation/ABI/,,;
my $nametag = "File $fn";
$data{$nametag}->{what} = "File $name";
$data{$nametag}->{type} = "File";
$data{$nametag}->{file} = $name;
$data{$nametag}->{filepath} = $file;
$data{$nametag}->{is_file} = 1;
$data{$nametag}->{line_no} = 1;
my $type = $file;
$type =~ s,.*/(.*)/.*,$1,;
my $what;
my $new_what;
my $tag = "";
my $ln;
my $xrefs;
my $space;
my @labels;
my $label = "";
print STDERR "Opening $file\n" if ($debug > 1);
open IN, $file;
while(<IN>) {
$ln++;
if (m/^(\S+)(:\s*)(.*)/i) {
my $new_tag = lc($1);
my $sep = $2;
my $content = $3;
if (!($new_tag =~ m/(what|where|date|kernelversion|contact|description|users)/)) {
if ($tag eq "description") {
# New "tag" is actually part of
# description. Don't consider it a tag
$new_tag = "";
} elsif ($tag ne "") {
parse_error($file, $ln, "tag '$tag' is invalid", $_);
}
}
# Invalid, but it is a common mistake
if ($new_tag eq "where") {
parse_error($file, $ln, "tag 'Where' is invalid. Should be 'What:' instead", "");
$new_tag = "what";
}
if ($new_tag =~ m/what/) {
$space = "";
$content =~ s/[,.;]$//;
push @{$symbols{$content}->{file}}, " $file:" . ($ln - 1);
if ($tag =~ m/what/) {
$what .= "\xac" . $content;
} else {
if ($what) {
parse_error($file, $ln, "What '$what' doesn't have a description", "") if (!$data{$what}->{description});
foreach my $w(split /\xac/, $what) {
$symbols{$w}->{xref} = $what;
};
}
$what = $content;
$label = $content;
$new_what = 1;
}
push @labels, [($content, $label)];
$tag = $new_tag;
push @{$data{$nametag}->{symbols}}, $content if ($data{$nametag}->{what});
next;
}
if ($tag ne "" && $new_tag) {
$tag = $new_tag;
if ($new_what) {
@{$data{$what}->{label_list}} = @labels if ($data{$nametag}->{what});
@labels = ();
$label = "";
$new_what = 0;
$data{$what}->{type} = $type;
if (!defined($data{$what}->{file})) {
$data{$what}->{file} = $name;
$data{$what}->{filepath} = $file;
} else {
if ($name ne $data{$what}->{file}) {
$data{$what}->{file} .= " " . $name;
$data{$what}->{filepath} .= " " . $file;
}
}
print STDERR "\twhat: $what\n" if ($debug > 1);
$data{$what}->{line_no} = $ln;
} else {
$data{$what}->{line_no} = $ln if (!defined($data{$what}->{line_no}));
}
if (!$what) {
parse_error($file, $ln, "'What:' should come first:", $_);
next;
}
if ($new_tag eq "description") {
$sep =~ s,:, ,;
$content = ' ' x length($new_tag) . $sep . $content;
while ($content =~ s/\t+/' ' x (length($&) * 8 - length($`) % 8)/e) {}
if ($content =~ m/^(\s*)(\S.*)$/) {
# Preserve initial spaces for the first line
$space = $1;
$content = "$2\n";
$data{$what}->{$tag} .= $content;
} else {
undef($space);
}
} else {
$data{$what}->{$tag} = $content;
}
next;
}
}
# Store any contents before tags at the database
if (!$tag && $data{$nametag}->{what}) {
$data{$nametag}->{description} .= $_;
next;
}
if ($tag eq "description") {
my $content = $_;
while ($content =~ s/\t+/' ' x (length($&) * 8 - length($`) % 8)/e) {}
if (m/^\s*\n/) {
$data{$what}->{$tag} .= "\n";
next;
}
if (!defined($space)) {
# Preserve initial spaces for the first line
if ($content =~ m/^(\s*)(\S.*)$/) {
$space = $1;
$content = "$2\n";
}
} else {
$space = "" if (!($content =~ s/^($space)//));
}
$data{$what}->{$tag} .= $content;
next;
}
if (m/^\s*(.*)/) {
$data{$what}->{$tag} .= "\n$1";
$data{$what}->{$tag} =~ s/\n+$//;
next;
}
# Everything else is error
parse_error($file, $ln, "Unexpected content", $_);
}
$data{$nametag}->{description} =~ s/^\n+// if ($data{$nametag}->{description});
if ($what) {
parse_error($file, $ln, "What '$what' doesn't have a description", "") if (!$data{$what}->{description});
foreach my $w(split /\xac/,$what) {
$symbols{$w}->{xref} = $what;
};
}
close IN;
}
sub create_labels {
my %labels;
foreach my $what (keys %data) {
next if ($data{$what}->{file} eq "File");
foreach my $p (@{$data{$what}->{label_list}}) {
my ($content, $label) = @{$p};
$label = "abi_" . $label . " ";
$label =~ tr/A-Z/a-z/;
# Convert special chars to "_"
$label =~s/([\x00-\x2f\x3a-\x40\x5b-\x60\x7b-\xff])/_/g;
$label =~ s,_+,_,g;
$label =~ s,_$,,;
# Avoid duplicated labels
while (defined($labels{$label})) {
my @chars = ("A".."Z", "a".."z");
$label .= $chars[rand @chars];
}
$labels{$label} = 1;
$data{$what}->{label} = $label;
# only one label is enough
last;
}
}
}
#
# Outputs the book on ReST format
#
# \b doesn't work well with paths. So, we need to define something else:
# Boundaries are punct characters, spaces and end-of-line
my $start = qr {(^|\s|\() }x;
my $bondary = qr { ([,.:;\)\s]|\z) }x;
my $xref_match = qr { $start(\/(sys|config|proc|dev|kvd)\/[^,.:;\)\s]+)$bondary }x;
my $symbols = qr { ([\x01-\x08\x0e-\x1f\x21-\x2f\x3a-\x40\x7b-\xff]) }x;
sub output_rest {
create_labels();
my $part = "";
foreach my $what (sort {
($data{$a}->{type} eq "File") cmp ($data{$b}->{type} eq "File") ||
$a cmp $b
} keys %data) {
my $type = $data{$what}->{type};
my @file = split / /, $data{$what}->{file};
my @filepath = split / /, $data{$what}->{filepath};
if ($enable_lineno) {
printf "#define LINENO %s%s#%s\n\n",
$prefix, $file[0],
$data{$what}->{line_no};
}
my $w = $what;
if ($type ne "File") {
my $cur_part = $what;
if ($what =~ '/') {
if ($what =~ m#^(\/?(?:[\w\-]+\/?){1,2})#) {
$cur_part = "Symbols under $1";
$cur_part =~ s,/$,,;
}
}
if ($cur_part ne "" && $part ne $cur_part) {
$part = $cur_part;
my $bar = $part;
$bar =~ s/./-/g;
print "$part\n$bar\n\n";
}
printf ".. _%s:\n\n", $data{$what}->{label};
my @names = split /\xac/,$w;
my $len = 0;
foreach my $name (@names) {
$name =~ s/$symbols/\\$1/g;
$name = "**$name**";
$len = length($name) if (length($name) > $len);
}
print "+-" . "-" x $len . "-+\n";
foreach my $name (@names) {
printf "| %s", $name . " " x ($len - length($name)) . " |\n";
print "+-" . "-" x $len . "-+\n";
}
print "\n";
}
for (my $i = 0; $i < scalar(@filepath); $i++) {
my $path = $filepath[$i];
my $f = $file[$i];
$path =~ s,.*/(.*/.*),$1,;;
$path =~ s,[/\-],_,g;;
my $fileref = "abi_file_".$path;
if ($type eq "File") {
print ".. _$fileref:\n\n";
} else {
print "Defined on file :ref:`$f <$fileref>`\n\n";
}
}
if ($type eq "File") {
my $bar = $w;
$bar =~ s/./-/g;
print "$w\n$bar\n\n";
}
my $desc = "";
$desc = $data{$what}->{description} if (defined($data{$what}->{description}));
$desc =~ s/\s+$/\n/;
if (!($desc =~ /^\s*$/)) {
if ($description_is_rst) {
# Remove title markups from the description
# Having titles inside ABI files will only work if extra
# care would be taken in order to strictly follow the same
# level order for each markup.
$desc =~ s/\n[\-\*\=\^\~]+\n/\n\n/g;
# Enrich text by creating cross-references
my $new_desc = "";
my $init_indent = -1;
my $literal_indent = -1;
open(my $fh, "+<", \$desc);
while (my $d = <$fh>) {
my $indent = $d =~ m/^(\s+)/;
my $spaces = length($indent);
$init_indent = $indent if ($init_indent < 0);
if ($literal_indent >= 0) {
if ($spaces > $literal_indent) {
$new_desc .= $d;
next;
} else {
$literal_indent = -1;
}
} else {
if ($d =~ /()::$/ && !($d =~ /^\s*\.\./)) {
$literal_indent = $spaces;
}
}
$d =~ s,Documentation/(?!devicetree)(\S+)\.rst,:doc:`/$1`,g;
my @matches = $d =~ m,Documentation/ABI/([\w\/\-]+),g;
foreach my $f (@matches) {
my $xref = $f;
my $path = $f;
$path =~ s,.*/(.*/.*),$1,;;
$path =~ s,[/\-],_,g;;
$xref .= " <abi_file_" . $path . ">";
$d =~ s,\bDocumentation/ABI/$f\b,:ref:`$xref`,g;
}
# Seek for cross reference symbols like /sys/...
@matches = $d =~ m/$xref_match/g;
foreach my $s (@matches) {
next if (!($s =~ m,/,));
if (defined($data{$s}) && defined($data{$s}->{label})) {
my $xref = $s;
$xref =~ s/$symbols/\\$1/g;
$xref = ":ref:`$xref <" . $data{$s}->{label} . ">`";
$d =~ s,$start$s$bondary,$1$xref$2,g;
}
}
$new_desc .= $d;
}
close $fh;
print "$new_desc\n\n";
} else {
$desc =~ s/^\s+//;
# Remove title markups from the description, as they won't work
$desc =~ s/\n[\-\*\=\^\~]+\n/\n\n/g;
if ($desc =~ m/\:\n/ || $desc =~ m/\n[\t ]+/ || $desc =~ m/[\x00-\x08\x0b-\x1f\x7b-\xff]/) {
# put everything inside a code block
$desc =~ s/\n/\n /g;
print "::\n\n";
print " $desc\n\n";
} else {
# Escape any special chars from description
$desc =~s/([\x00-\x08\x0b-\x1f\x21-\x2a\x2d\x2f\x3c-\x40\x5c\x5e-\x60\x7b-\xff])/\\$1/g;
print "$desc\n\n";
}
}
} else {
print "DESCRIPTION MISSING for $what\n\n" if (!$data{$what}->{is_file});
}
if ($data{$what}->{symbols}) {
printf "Has the following ABI:\n\n";
foreach my $content(@{$data{$what}->{symbols}}) {
my $label = $data{$symbols{$content}->{xref}}->{label};
# Escape special chars from content
$content =~s/([\x00-\x1f\x21-\x2f\x3a-\x40\x7b-\xff])/\\$1/g;
print "- :ref:`$content <$label>`\n\n";
}
}
if (defined($data{$what}->{users})) {
my $users = $data{$what}->{users};
$users =~ s/\n/\n\t/g;
printf "Users:\n\t%s\n\n", $users if ($users ne "");
}
}
}
#
# Searches for ABI symbols
#
sub search_symbols {
foreach my $what (sort keys %data) {
next if (!($what =~ m/($arg)/));
my $type = $data{$what}->{type};
next if ($type eq "File");
my $file = $data{$what}->{filepath};
$what =~ s/\xac/, /g;
my $bar = $what;
$bar =~ s/./-/g;
print "\n$what\n$bar\n\n";
my $kernelversion = $data{$what}->{kernelversion} if (defined($data{$what}->{kernelversion}));
my $contact = $data{$what}->{contact} if (defined($data{$what}->{contact}));
my $users = $data{$what}->{users} if (defined($data{$what}->{users}));
my $date = $data{$what}->{date} if (defined($data{$what}->{date}));
my $desc = $data{$what}->{description} if (defined($data{$what}->{description}));
$kernelversion =~ s/^\s+// if ($kernelversion);
$contact =~ s/^\s+// if ($contact);
if ($users) {
$users =~ s/^\s+//;
$users =~ s/\n//g;
}
$date =~ s/^\s+// if ($date);
$desc =~ s/^\s+// if ($desc);
printf "Kernel version:\t\t%s\n", $kernelversion if ($kernelversion);
printf "Date:\t\t\t%s\n", $date if ($date);
printf "Contact:\t\t%s\n", $contact if ($contact);
printf "Users:\t\t\t%s\n", $users if ($users);
print "Defined on file(s):\t$file\n\n";
print "Description:\n\n$desc";
}
}
# Exclude /sys/kernel/debug and /sys/kernel/tracing from the search path
sub dont_parse_special_attributes {
if (($File::Find::dir =~ m,^/sys/kernel,)) {
return grep {!/(debug|tracing)/ } @_;
}
if (($File::Find::dir =~ m,^/sys/fs,)) {
return grep {!/(pstore|bpf|fuse)/ } @_;
}
return @_
}
my %leaf;
my %aliases;
my @files;
my %root;
sub graph_add_file {
my $file = shift;
my $type = shift;
my $dir = $file;
$dir =~ s,^(.*/).*,$1,;
$file =~ s,.*/,,;
my $name;
my $file_ref = \%root;
foreach my $edge(split "/", $dir) {
$name .= "$edge/";
if (!defined ${$file_ref}{$edge}) {
${$file_ref}{$edge} = { };
}
$file_ref = \%{$$file_ref{$edge}};
${$file_ref}{"__name"} = [ $name ];
}
$name .= "$file";
${$file_ref}{$file} = {
"__name" => [ $name ]
};
return \%{$$file_ref{$file}};
}
sub graph_add_link {
my $file = shift;
my $link = shift;
# Traverse graph to find the reference
my $file_ref = \%root;
foreach my $edge(split "/", $file) {
$file_ref = \%{$$file_ref{$edge}} || die "Missing node!";
}
# do a BFS
my @queue;
my %seen;
my $base_name;
my $st;
push @queue, $file_ref;
$seen{$start}++;
while (@queue) {
my $v = shift @queue;
my @child = keys(%{$v});
foreach my $c(@child) {
next if $seen{$$v{$c}};
next if ($c eq "__name");
# Add new name
my $name = @{$$v{$c}{"__name"}}[0];
if ($name =~ s#^$file/#$link/#) {
push @{$$v{$c}{"__name"}}, $name;
}
# Add child to the queue and mark as seen
push @queue, $$v{$c};
$seen{$c}++;
}
}
}
my $escape_symbols = qr { ([\x01-\x08\x0e-\x1f\x21-\x29\x2b-\x2d\x3a-\x40\x7b-\xfe]) }x;
sub parse_existing_sysfs {
my $file = $File::Find::name;
# Ignore cgroup and firmware
return if ($file =~ m#^/sys/(fs/cgroup|firmware)/#);
my $mode = (lstat($file))[2];
my $abs_file = abs_path($file);
if (S_ISLNK($mode)) {
$aliases{$file} = $abs_file;
return;
}
return if (S_ISDIR($mode));
# Trivial: file is defined exactly the same way at ABI What:
return if (defined($data{$file}));
return if (defined($data{$abs_file}));
push @files, graph_add_file($abs_file, "file");
}
sub get_leave($)
{
my $what = shift;
my $leave;
my $l = $what;
my $stop = 1;
$leave = $l;
$leave =~ s,/$,,;
$leave =~ s,.*/,,;
$leave =~ s/[\(\)]//g;
# $leave is used to improve search performance at
# check_undefined_symbols, as the algorithm there can seek
# for a small number of "what". It also allows giving a
# hint about a leave with the same name somewhere else.
# However, there are a few occurences where the leave is
# either a wildcard or a number. Just group such cases
# altogether.
if ($leave =~ m/^\.\*/ || $leave eq "" || $leave =~ /^\d+$/) {
$leave = "others";
}
return $leave;
}
sub check_undefined_symbols {
foreach my $file_ref (sort @files) {
my @names = @{$$file_ref{"__name"}};
my $file = $names[0];
my $defined = 0;
my $exact = 0;
my $found_string;
my $leave = get_leave($file);
if (!defined($leaf{$leave})) {
$leave = "others";
}
my $what = $leaf{$leave};
my $path = $file;
$path =~ s,(.*/).*,$1,;
if ($search_string) {
next if (!($file =~ m#$search_string#));
$found_string = 1;
}
foreach my $a (@names) {
print "--> $a\n" if ($found_string && $hint);
foreach my $w (split /\xac/, $what) {
if ($a =~ m#^$w$#) {
$exact = 1;
last;
}
}
}
$defined++;
next if ($exact);
# Ignore some sysfs nodes
next if ($file =~ m#/(sections|notes)/#);
# Would need to check at
# Documentation/admin-guide/kernel-parameters.txt, but this
# is not easily parseable.
next if ($file =~ m#/parameters/#);
if ($hint && $defined && (!$search_string || $found_string)) {
$what =~ s/\xac/\n\t/g;
if ($leave ne "others") {
print " more likely regexes:\n\t$what\n";
} else {
print " tested regexes:\n\t$what\n";
}
next;
}
print "$file not found.\n" if (!$search_string || $found_string);
}
}
sub undefined_symbols {
find({
wanted =>\&parse_existing_sysfs,
preprocess =>\&dont_parse_special_attributes,
no_chdir => 1
}, $sysfs_prefix);
$leaf{"others"} = "";
foreach my $w (sort keys %data) {
foreach my $what (split /\xac/,$w) {
next if (!($what =~ m/^$sysfs_prefix/));
# Convert what into regular expressions
$what =~ s,/\.\.\./,/*/,g;
$what =~ s,\*,.*,g;
# Temporarily change [0-9]+ type of patterns
$what =~ s/\[0\-9\]\+/\xff/g;
# Temporarily change [\d+-\d+] type of patterns
$what =~ s/\[0\-\d+\]/\xff/g;
$what =~ s/\[(\d+)\]/\xf4$1\xf5/g;
# Temporarily change [0-9] type of patterns
$what =~ s/\[(\d)\-(\d)\]/\xf4$1-$2\xf5/g;
# Handle multiple option patterns
$what =~ s/[\{\<\[]([\w_]+)(?:[,|]+([\w_]+)){1,}[\}\>\]]/($1|$2)/g;
# Handle wildcards
$what =~ s/\<[^\>]+\>/.*/g;
$what =~ s/\{[^\}]+\}/.*/g;
$what =~ s/\[[^\]]+\]/.*/g;
$what =~ s/[XYZ]/.*/g;
# Recover [0-9] type of patterns
$what =~ s/\xf4/[/g;
$what =~ s/\xf5/]/g;
# Remove duplicated spaces
$what =~ s/\s+/ /g;
# Special case: this ABI has a parenthesis on it
$what =~ s/sqrt\(x^2\+y^2\+z^2\)/sqrt\(x^2\+y^2\+z^2\)/;
# Special case: drop comparition as in:
# What: foo = <something>
# (this happens on a few IIO definitions)
$what =~ s,\s*\=.*$,,;
my $leave = get_leave($what);
# Escape all other symbols
$what =~ s/$escape_symbols/\\$1/g;
$what =~ s/\\\\/\\/g;
$what =~ s/\\([\[\]\(\)\|])/$1/g;
$what =~ s/(\d+)\\(-\d+)/$1$2/g;
$what =~ s/\xff/\\d+/g;
# Special case: IIO ABI which a parenthesis.
$what =~ s/sqrt(.*)/sqrt\(.*\)/;
my $added = 0;
foreach my $l (split /\|/, $leave) {
if (defined($leaf{$l})) {
next if ($leaf{$l} =~ m/\b$what\b/);
$leaf{$l} .= "\xac" . $what;
$added = 1;
} else {
$leaf{$l} = $what;
$added = 1;
}
}
if ($search_string && $added) {
print "What: $what\n" if ($what =~ m#$search_string#);
}
}
}
# Take links into account
foreach my $link (keys %aliases) {
my $abs_file = $aliases{$link};
graph_add_link($abs_file, $link);
}
check_undefined_symbols;
}
# Ensure that the prefix will always end with a slash
# While this is not needed for find, it makes the patch nicer
# with --enable-lineno
$prefix =~ s,/?$,/,;
if ($cmd eq "undefined" || $cmd eq "search") {
$show_warnings = 0;
}
#
# Parses all ABI files located at $prefix dir
#
find({wanted =>\&parse_abi, no_chdir => 1}, $prefix);
print STDERR Data::Dumper->Dump([\%data], [qw(*data)]) if ($debug);
#
# Handles the command
#
if ($cmd eq "undefined") {
undefined_symbols;
} elsif ($cmd eq "search") {
search_symbols;
} else {
if ($cmd eq "rest") {
output_rest;
}
# Warn about duplicated ABI entries
foreach my $what(sort keys %symbols) {
my @files = @{$symbols{$what}->{file}};
next if (scalar(@files) == 1);
printf STDERR "Warning: $what is defined %d times: @files\n",
scalar(@files);
}
}
__END__
=head1 NAME
abi_book.pl - parse the Linux ABI files and produce a ReST book.
=head1 SYNOPSIS
B<abi_book.pl> [--debug] [--enable-lineno] [--man] [--help]
[--(no-)rst-source] [--dir=<dir>] [--show-hints]
[--search-string <regex>]
<COMAND> [<ARGUMENT>]
Where <COMMAND> can be:
=over 8
B<search> [SEARCH_REGEX] - search for [SEARCH_REGEX] inside ABI
B<rest> - output the ABI in ReST markup language
B<validate> - validate the ABI contents
B<undefined> - existing symbols at the system that aren't
defined at Documentation/ABI
=back
=head1 OPTIONS
=over 8
=item B<--dir>
Changes the location of the ABI search. By default, it uses
the Documentation/ABI directory.
=item B<--rst-source> and B<--no-rst-source>
The input file may be using ReST syntax or not. Those two options allow
selecting between a rst-compliant source ABI (--rst-source), or a
plain text that may be violating ReST spec, so it requres some escaping
logic (--no-rst-source).
=item B<--enable-lineno>
Enable output of #define LINENO lines.
=item B<--debug>
Put the script in verbose mode, useful for debugging. Can be called multiple
times, to increase verbosity.
=item B<--show-hints>
Show hints about possible definitions for the missing ABI symbols.
Used only when B<undefined>.
=item B<--search-string> [regex string]
Show only occurences that match a search string.
Used only when B<undefined>.
=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 ABI files from ABI DIR (usually located at Documentation/ABI),
allowing to search for ABI symbols or to produce a ReST book containing
the Linux ABI documentation.
=head1 EXAMPLES
Search for all stable symbols with the word "usb":
=over 8
$ scripts/get_abi.pl search usb --dir Documentation/ABI/stable
=back
Search for all symbols that match the regex expression "usb.*cap":
=over 8
$ scripts/get_abi.pl search usb.*cap
=back
Output all obsoleted symbols in ReST format
=over 8
$ scripts/get_abi.pl rest --dir Documentation/ABI/obsolete
=back
=head1 BUGS
Report bugs to Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
=head1 COPYRIGHT
Copyright (c) 2016-2019 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