#! /usr/bin/env perl
# Copyright 2002-2019 The OpenSSL Project Authors. All Rights Reserved.
#
# Licensed under the OpenSSL license (the "License").  You may not use
# this file except in compliance with the License.  You can obtain a copy
# in the file LICENSE in the source distribution or at
# https://www.openssl.org/source/license.html


require 5.10.0;
use warnings;
use strict;
use Pod::Checker;
use File::Find;
use File::Basename;
use File::Spec::Functions;
use Getopt::Std;
use lib catdir(dirname($0), "perl");
use OpenSSL::Util::Pod;

# Options.
our($opt_d);
our($opt_h);
our($opt_l);
our($opt_n);
our($opt_p);
our($opt_u);
our($opt_c);

sub help()
{
    print <<EOF;
Find small errors (nits) in documentation.  Options:
    -d Detailed list of undocumented (implies -u)
    -l Print bogus links
    -n Print nits in POD pages
    -p Warn if non-public name documented (implies -n)
    -u Count undocumented functions
    -h Print this help message
    -c List undocumented commands and options
EOF
    exit;
}

my $temp = '/tmp/docnits.txt';
my $OUT;
my %public;

my %mandatory_sections =
    ( '*'    => [ 'NAME', 'DESCRIPTION', 'COPYRIGHT' ],
      1      => [ 'SYNOPSIS', 'OPTIONS' ],
      3      => [ 'SYNOPSIS', 'RETURN VALUES' ],
      5      => [ ],
      7      => [ ] );

# Cross-check functions in the NAME and SYNOPSIS section.
sub name_synopsis()
{
    my $id = shift;
    my $filename = shift;
    my $contents = shift;

    # Get NAME section and all words in it.
    return unless $contents =~ /=head1 NAME(.*)=head1 SYNOPSIS/ms;
    my $tmp = $1;
    $tmp =~ tr/\n/ /;
    print "$id trailing comma before - in NAME\n" if $tmp =~ /, *-/;
    $tmp =~ s/ -.*//g;
    $tmp =~ s/  */ /g;
    print "$id missing comma in NAME\n" if $tmp =~ /[^,] /;
    $tmp =~ s/,//g;

    my $dirname = dirname($filename);
    my $simplename = basename($filename);
    $simplename =~ s/.pod$//;
    my $foundfilename = 0;
    my %foundfilenames = ();
    my %names;
    foreach my $n ( split ' ', $tmp ) {
        $names{$n} = 1;
        $foundfilename++ if $n eq $simplename;
        $foundfilenames{$n} = 1
            if -f "$dirname/$n.pod" && $n ne $simplename;
    }
    print "$id the following exist as other .pod files:\n",
        join(" ", sort keys %foundfilenames), "\n"
        if %foundfilenames;
    print "$id $simplename (filename) missing from NAME section\n"
        unless $foundfilename;
    foreach my $n ( keys %names ) {
        print "$id $n is not public\n"
            if $opt_p and !defined $public{$n};
    }

    # Find all functions in SYNOPSIS
    return unless $contents =~ /=head1 SYNOPSIS(.*)=head1 DESCRIPTION/ms;
    my $syn = $1;
    foreach my $line ( split /\n+/, $syn ) {
        my $sym;
        $line =~ s/STACK_OF\([^)]+\)/int/g;
        $line =~ s/__declspec\([^)]+\)//;
        if ( $line =~ /env (\S*)=/ ) {
            # environment variable env NAME=...
            $sym = $1;
        } elsif ( $line =~ /typedef.*\(\*(\S+)\)\(.*/ ) {
            # a callback function pointer: typedef ... (*NAME)(...
            $sym = $1;
        } elsif ( $line =~ /typedef.* (\S+)\(.*/ ) {
            # a callback function signature: typedef ... NAME(...
            $sym = $1;
        } elsif ( $line =~ /typedef.* (\S+);/ ) {
            # a simple typedef: typedef ... NAME;
            $sym = $1;
        } elsif ( $line =~ /enum (\S*) \{/ ) {
            # an enumeration: enum ... {
            $sym = $1;
        } elsif ( $line =~ /#define ([A-Za-z0-9_]+)/ ) {
            $sym = $1;
        } elsif ( $line =~ /([A-Za-z0-9_]+)\(/ ) {
            $sym = $1;
        }
        else {
            next;
        }
        print "$id $sym missing from NAME section\n"
            unless defined $names{$sym};
        $names{$sym} = 2;

        # Do some sanity checks on the prototype.
        print "$id prototype missing spaces around commas: $line\n"
            if ( $line =~ /[a-z0-9],[^ ]/ );
    }

    foreach my $n ( keys %names ) {
        next if $names{$n} == 2;
        print "$id $n missing from SYNOPSIS\n";
    }
}

# Check if SECTION ($3) is located before BEFORE ($4)
sub check_section_location()
{
    my $id = shift;
    my $contents = shift;
    my $section = shift;
    my $before = shift;

    return
        unless $contents =~ /=head1 $section/ and $contents =~ /=head1 $before/;
    print "$id $section should be placed before $before section\n"
        if $contents =~ /=head1 $before.*=head1 $section/ms;
}

sub check()
{
    my $filename = shift;
    my $dirname = basename(dirname($filename));

    my $contents = '';
    {
        local $/ = undef;
        open POD, $filename or die "Couldn't open $filename, $!";
        $contents = <POD>;
        close POD;
    }

    my $id = "${filename}:1:";

    # Check ordering of some sections in man3
    if ( $filename =~ m|man3/| ) {
        &check_section_location($id, $contents, "RETURN VALUES", "EXAMPLES");
        &check_section_location($id, $contents, "SEE ALSO", "HISTORY");
        &check_section_location($id, $contents, "EXAMPLES", "SEE ALSO");
    }

    &name_synopsis($id, $filename, $contents)
        unless $contents =~ /=for comment generic/
            or $filename =~ m@man[157]/@;

    print "$id doesn't start with =pod\n"
        if $contents !~ /^=pod/;
    print "$id doesn't end with =cut\n"
        if $contents !~ /=cut\n$/;
    print "$id more than one cut line.\n"
        if $contents =~ /=cut.*=cut/ms;
    print "$id EXAMPLE not EXAMPLES section.\n"
        if $contents =~ /=head1 EXAMPLE[^S]/;
    print "$id WARNING not WARNINGS section.\n"
        if $contents =~ /=head1 WARNING[^S]/;
    print "$id missing copyright\n"
        if $contents !~ /Copyright .*/;
    print "$id copyright not last\n"
        if $contents =~ /head1 COPYRIGHT.*=head/ms;
    print "$id head2 in All uppercase\n"
        if $contents =~ /head2\s+[A-Z ]+\n/;
    print "$id extra space after head\n"
        if $contents =~ /=head\d\s\s+/;
    print "$id period in NAME section\n"
        if $contents =~ /=head1 NAME.*\.\n.*=head1 SYNOPSIS/ms;
    print "$id POD markup in NAME section\n"
        if $contents =~ /=head1 NAME.*[<>].*=head1 SYNOPSIS/ms;
    print "$id Duplicate $1 in L<>\n"
        if $contents =~ /L<([^>]*)\|([^>]*)>/ && $1 eq $2;
    print "$id Bad =over $1\n"
        if $contents =~ /=over([^ ][^24])/;
    print "$id Possible version style issue\n"
        if $contents =~ /OpenSSL version [019]/;

    if ( $contents !~ /=for comment multiple includes/ ) {
        # Look for multiple consecutive openssl #include lines
        # (non-consecutive lines are okay; see man3/MD5.pod).
        if ( $contents =~ /=head1 SYNOPSIS(.*)=head1 DESCRIPTION/ms ) {
            my $count = 0;
            foreach my $line ( split /\n+/, $1 ) {
                if ( $line =~ m@include <openssl/@ ) {
                    print "$id has multiple includes\n" if ++$count == 2;
                } else {
                    $count = 0;
                }
            }
        }
    }

    open my $OUT, '>', $temp
        or die "Can't open $temp, $!";
    podchecker($filename, $OUT);
    close $OUT;
    open $OUT, '<', $temp
        or die "Can't read $temp, $!";
    while ( <$OUT> ) {
        next if /\(section\) in.*deprecated/;
        print;
    }
    close $OUT;
    unlink $temp || warn "Can't remove $temp, $!";

    # Find what section this page is in; assume 3.
    my $section = 3;
    $section = $1 if $dirname =~ /man([1-9])/;

    foreach ((@{$mandatory_sections{'*'}}, @{$mandatory_sections{$section}})) {
        # Skip "return values" if not -s
        print "$id: missing $_ head1 section\n"
            if $contents !~ /^=head1\s+${_}\s*$/m;
    }
}

my %dups;

sub parsenum()
{
    my $file = shift;
    my @apis;

    open my $IN, '<', $file
        or die "Can't open $file, $!, stopped";

    while ( <$IN> ) {
        next if /^#/;
        next if /\bNOEXIST\b/;
        next if /\bEXPORT_VAR_AS_FUNC\b/;
        my @fields = split();
        die "Malformed line $_"
            if scalar @fields != 2 && scalar @fields != 4;
        push @apis, $fields[0];
    }

    close $IN;

    print "# Found ", scalar(@apis), " in $file\n" unless $opt_p;
    return sort @apis;
}

sub getdocced()
{
    my $dir = shift;
    my %return;

    foreach my $pod ( glob("$dir/*.pod") ) {
        my %podinfo = extract_pod_info($pod);
        foreach my $n ( @{$podinfo{names}} ) {
            $return{$n} = $pod;
            print "# Duplicate $n in $pod and $dups{$n}\n"
                if defined $dups{$n} && $dups{$n} ne $pod;
            $dups{$n} = $pod;
        }
    }

    return %return;
}

my %docced;

sub checkmacros()
{
    my $count = 0;
    my %seen;

    print "# Checking macros (approximate)\n";
    foreach my $f ( glob('include/openssl/*.h') ) {
        # Skip some internals we don't want to document yet.
        next if $f eq 'include/openssl/asn1.h';
        next if $f eq 'include/openssl/asn1t.h';
        next if $f eq 'include/openssl/err.h';
        open(IN, $f) || die "Can't open $f, $!";
        while ( <IN> ) {
            next unless /^#\s*define\s*(\S+)\(/;
            my $macro = $1;
            next if $docced{$macro} || defined $seen{$macro};
            next if $macro =~ /i2d_/
                || $macro =~ /d2i_/
                || $macro =~ /DEPRECATEDIN/
                || $macro =~ /IMPLEMENT_/
                || $macro =~ /DECLARE_/;
            print "$f:$macro\n" if $opt_d;
            $count++;
            $seen{$macro} = 1;
        }
        close(IN);
    }
    print "# Found $count macros missing (not all should be documented)\n"
}

sub printem()
{
    my $libname = shift;
    my $numfile = shift;
    my $count = 0;
    my %seen;

    foreach my $func ( &parsenum($numfile) ) {
        next if $docced{$func} || defined $seen{$func};

        # Skip ASN1 utilities
        next if $func =~ /^ASN1_/;

        print "$libname:$func\n" if $opt_d;
        $count++;
        $seen{$func} = 1;
    }
    print "# Found $count missing from $numfile\n\n";
}


# Collection of links in each POD file.
# filename => [ "foo(1)", "bar(3)", ... ]
my %link_collection = ();
# Collection of names in each POD file.
# "name(s)" => filename
my %name_collection = ();

sub collectnames {
    my $filename = shift;
    $filename =~ m|man(\d)/|;
    my $section = $1;
    my $simplename = basename($filename, ".pod");
    my $id = "${filename}:1:";

    my $contents = '';
    {
        local $/ = undef;
        open POD, $filename or die "Couldn't open $filename, $!";
        $contents = <POD>;
        close POD;
    }

    $contents =~ /=head1 NAME([^=]*)=head1 /ms;
    my $tmp = $1;
    unless (defined $tmp) {
        print "$id weird name section\n";
        return;
    }
    $tmp =~ tr/\n/ /;
    $tmp =~ s/-.*//g;

    my @names = map { s/\s+//g; $_ } split(/,/, $tmp);
    unless (grep { $simplename eq $_ } @names) {
        print "$id missing $simplename\n";
        push @names, $simplename;
    }
    foreach my $name (@names) {
        next if $name eq "";
        my $name_sec = "$name($section)";
        if (! exists $name_collection{$name_sec}) {
            $name_collection{$name_sec} = $filename;
        } else { #elsif ($filename ne $name_collection{$name_sec}) {
            print "$id $name_sec also in $name_collection{$name_sec}\n";
        }
    }

    my @foreign_names =
        map { map { s/\s+//g; $_ } split(/,/, $_) }
        $contents =~ /=for\s+comment\s+foreign\s+manuals:\s*(.*)\n\n/;
    foreach (@foreign_names) {
        $name_collection{$_} = undef; # It still exists!
    }

    my @links = $contents =~ /L<
                              # if the link is of the form L<something|name(s)>,
                              # then remove 'something'.  Note that 'something'
                              # may contain POD codes as well...
                              (?:(?:[^\|]|<[^>]*>)*\|)?
                              # we're only interested in references that have
                              # a one digit section number
                              ([^\/>\(]+\(\d\))
                             /gx;
    $link_collection{$filename} = [ @links ];
}

sub checklinks {
    foreach my $filename (sort keys %link_collection) {
        foreach my $link (@{$link_collection{$filename}}) {
            print "${filename}:1: reference to non-existing $link\n"
                unless exists $name_collection{$link};
        }
    }
}

sub publicize() {
    foreach my $name ( &parsenum('util/libcrypto.num') ) {
        $public{$name} = 1;
    }
    foreach my $name ( &parsenum('util/libssl.num') ) {
        $public{$name} = 1;
    }
    foreach my $name ( &parsenum('util/private.num') ) {
        $public{$name} = 1;
    }
}

my %skips = (
    'aes128' => 1,
    'aes192' => 1,
    'aes256' => 1,
    'camellia128' => 1,
    'camellia192' => 1,
    'camellia256' => 1,
    'des' => 1,
    'des3' => 1,
    'idea' => 1,
    '[cipher]' => 1,
    '[digest]' => 1,
);

sub checkflags() {
    my $cmd = shift;
    my %cmdopts;
    my %docopts;
    my $ok = 1;

    # Get the list of options in the command.
    open CFH, "./apps/openssl list --options $cmd|"
        || die "Can list options for $cmd, $!";
    while ( <CFH> ) {
        chop;
        s/ .$//;
        $cmdopts{$_} = 1;
    }
    close CFH;

    # Get the list of flags from the synopsis
    open CFH, "<doc/man1/$cmd.pod"
        || die "Can't open $cmd.pod, $!";
    while ( <CFH> ) {
        chop;
        last if /DESCRIPTION/;
        next unless /\[B<-([^ >]+)/;
        $docopts{$1} = 1;
    }
    close CFH;

    # See what's in the command not the manpage.
    my @undocced = ();
    foreach my $k ( keys %cmdopts ) {
        push @undocced, $k unless $docopts{$k};
    }
    if ( scalar @undocced > 0 ) {
        $ok = 0;
        foreach ( @undocced ) {
            print "doc/man1/$cmd.pod: Missing -$_\n";
        }
    }

    # See what's in the command not the manpage.
    my @unimpl = ();
    foreach my $k ( keys %docopts ) {
        push @unimpl, $k unless $cmdopts{$k};
    }
    if ( scalar @unimpl > 0 ) {
        $ok = 0;
        foreach ( @unimpl ) {
            next if defined $skips{$_};
            print "doc/man1/$cmd.pod: Not implemented -$_\n";
        }
    }

    return $ok;
}

getopts('cdlnphu');

&help() if $opt_h;
$opt_n = 1 if $opt_p;
$opt_u = 1 if $opt_d;

die "Need one of -[cdlnpu] flags.\n"
    unless $opt_c or $opt_l or $opt_n or $opt_u;

if ( $opt_c ) {
    my $ok = 1;
    my @commands = ();

    # Get list of commands.
    open FH, "./apps/openssl list -1 -commands|"
        || die "Can't list commands, $!";
    while ( <FH> ) {
        chop;
        push @commands, $_;
    }
    close FH;

    # See if each has a manpage.
    foreach ( @commands ) {
        next if $_ eq 'help' || $_ eq 'exit';
        if ( ! -f "doc/man1/$_.pod" ) {
            print "doc/man1/$_.pod does not exist\n";
            $ok = 0;
        } else {
            $ok = 0 if not &checkflags($_);
        }
    }

    # See what help is missing.
    open FH, "./apps/openssl list --missing-help |"
        || die "Can't list missing help, $!";
    while ( <FH> ) {
        chop;
        my ($cmd, $flag) = split;
        print "$cmd has no help for -$flag\n";
        $ok = 0;
    }
    close FH;

    exit 1 if not $ok;
}

if ( $opt_l ) {
    foreach (@ARGV ? @ARGV : glob('doc/*/*.pod')) {
        collectnames($_);
    }
    checklinks();
}

if ( $opt_n ) {
    &publicize() if $opt_p;
    foreach (@ARGV ? @ARGV : glob('doc/*/*.pod')) {
        &check($_);
    }
}

if ( $opt_u ) {
    my %temp = &getdocced('doc/man3');
    foreach ( keys %temp ) {
        $docced{$_} = $temp{$_};
    }
    &printem('crypto', 'util/libcrypto.num');
    &printem('ssl', 'util/libssl.num');
    &checkmacros();
}

exit;