source: vendor/perl/5.8.8/Porting/genlog

#!/usr/bin/perl -w
#
# Generate a nice changelist by querying perforce.
#
# Each change is described with the change number, description,
# which branch the change happened in, files modified,
# and who was responsible for entering the change.
#
# Can be called with a list of change numbers or a range of the
# form "12..42".  Changelog will be printed from highest number
# to lowest.
#
# Outputs the changelist to stdout.
#
# Gurusamy Sarathy <gsar@activestate.com>
#

use Text::Wrap;

$0 =~ s|^.*/||;
unless (@ARGV) {
    die <<USAGE;
        $0 [-p \$P4PORT] [-bi branch_include] [-be branch_exclude] <change numbers or from..to>
USAGE
}

my @changes;

my %editkind;
@editkind{ qw(   add      edit    delete integrate   branch )}
         = qw(     +         !         -        !>       +> );

my $p4port = $ENV{P4PORT} || 'localhost:1666';

my @branch_include;
my @branch_exclude;
my %branch_include;
my %branch_exclude;

while (@ARGV) {
    $_ = shift;
    if (/^(\d+)\.\.(\d+)?$/) {
        push @changes, $1 .. ($2 || (split(' ', `p4 changes -m 1`))[1]);
    }
    elsif (/^\d+$/) {
        push @changes, $_;
    }
    elsif (/^-p(.*)$/) {
        $p4port = $1 || shift;
    }
    elsif (/^-bi(.*)$/) {
        push @branch_include, $1 || shift;
    }
    elsif (/^-be(.*)$/) {
        push @branch_exclude, $1 || shift;
    }
    else {
        warn "Arguments must be change numbers, ignoring `$_'\n";
    }
}

@changes = sort { $b <=> $a } @changes;

@branch_include{@branch_include} = @branch_include if @branch_include;
@branch_exclude{@branch_exclude} = @branch_exclude if @branch_exclude;

my @desc = `p4 -p $p4port describe -s @changes`;
if ($?) {
    die "$0: `p4 -p $p4port describe -s @changes` failed, status[$?]\n";
}
else {
    tr/\r/\n/ foreach @desc;
    chomp @desc;
    while (@desc) {
        my ($change,$who,$date,$time,@log,$branch,$file,$type,%files);
        my $skip = 0;
        my $nbranch = 0;
        $_ = shift @desc;
        if (/^Change (\d+) by (\w+)\@.+ on (\S+) (\S+)\s*$/) {
            ($change, $who, $date, $time) = ($1,$2,$3,$4);
            $_ = shift @desc;  # get rid of empty line
            while (@desc) {
                $_ = shift @desc;
                last if /^Affected/;
                push @log, $_;    
            }
            if (/^Affected/) {
                $_ = shift @desc;  # get rid of empty line
                while ($_ = shift @desc) {
                    last unless /^\.\.\./;
                    if (m{^\.\.\. //depot/(.*?perl|[^/]*)/([^#]+)#\d+ (\w+)\s*$}) {
                        ($branch,$file,$type) = ($1,$2,$3);
                        $nbranch++;
                        if (exists $branch_exclude{$branch} or
                            @branch_include and
                            not exists $branch_include{$branch}) {
                            $skip++;
                        }
                        $files{$branch} = {} unless exists $files{$branch};
                        $files{$branch}{$type} = [] unless exists $files{$branch}{$type};
                        push @{$files{$branch}{$type}}, $file;
                    }
                    else {
                        warn "Unknown line [$_], ignoring\n";
                    }
                }
            }
        }
        next if ((not $change) or $skip);
        print "_" x 76, "\n";
        printf <<EOT, $change, $who, $date, $time;
[%6s] By: %-25s             on %9s %9s
EOT
        print "        Log: ";
        my $i = 0;
        while (@log) {
            $_ = shift @log;
            s/^\s*//;
            s/^\[.*\]\s*// unless $i ;
            # don't print last empty line
            if ($_ or @log) {
                print "             " if $i++;
                print "$_\n";
            }
        }
        for my $branch (sort keys %files) {
            printf "%11s: $branch\n", 'Branch';
            for my $kind (sort keys %{$files{$branch}}) {
                warn("### $kind ###\n"), next unless exists $editkind{$kind};
                my $files = $files{$branch}{$kind};
                # don't show large branches and integrations
                $files = ["($kind " . scalar(@$files) . ' files)']
                    if (@$files > 25 && ($kind eq 'integrate'
                                         || $kind eq 'branch'))
                       || @$files > 100;
                print wrap(sprintf("%12s ", $editkind{$kind}),
                           sprintf("%12s ", $editkind{$kind}),
                           "@$files\n");
            }
        }
    }
}