#!/usr/bin/perl
#
# bump-perl-version, DAPM 14 Jul 2009
#
# A utility to find, and optionally bump, references to the perl version
# number in various files within the perl source
#
# It's designed to work in two phases. First, when run with -s (scan),
# it searches all the files in MANIFEST looking for strings that appear to
# match the current perl version (or which it knows are *supposed* to
# contain the current version), and produces a list of them to stdout,
# along with a suggested edit. For example:
#
#     $ Porting/bump-perl-version -s 5.10.0 5.10.1 > /tmp/scan
#     $ cat /tmp/scan
#     Porting/config.sh
#     
#     52: -archlib='/opt/perl/lib/5.10.0/i686-linux-64int'
#         +archlib='/opt/perl/lib/5.10.1/i686-linux-64int'
#     ....
#
# At this point there will be false positives. Edit the file to remove
# those changes you don't want made. Then in the second phase, feed that
# list in, and it will change those lines in the files:
#
#     $ Porting/bump-perl-version -u < /tmp/scan
#
# (so line 52 of Porting/config.sh is now updated)
#
# The -i option can be used to combine these two steps (if you prefer to make
# all of the changes at once and then edit the results via git).

# This utility 'knows' about certain files and formats, and so can spot
# 'hidden' version numbers, like PERL_SUBVERSION=9.
#
# A third variant makes use of this knowledge to check that all the things
# it knows about are at the current version:
#
#    $ Porting/bump-perl-version -c 5.10.0
#
# XXX this script hasn't been tested against a major version bump yet,
# eg 5.11.0 to 5.12.0; there may be things it missed - DAPM 14 Jul 09
#
# Note there are various files and directories that it skips; these are
# ones that are unlikely to contain anything needing bumping, but which
# will generate lots fo false positives (eg pod/*). These are listed on
# STDERR as they are skipped.

use strict;
use warnings;
use autodie;
use Getopt::Std;
use ExtUtils::Manifest;


sub usage { die <<EOF }

@_

usage: $0 -c <C.C.C>
          -s <C.C.C> <N.N.N>
	  -u
	  -i <C.C.C> <N.N.N>

    -c check files and warn if any known string values (eg
	PERL_SUBVERSION) don't match the specified version

    -s scan files and produce list of possible change lines to stdout

    -u read in the scan file from stdin, and change all the lines specified

    -i scan files and make changes inplace

    C.C.C the current perl version, eg 5.10.0
    N.N.N the new     perl version, eg 5.10.1
EOF

my %opts;
getopts('csui', \%opts) or usage;
if ($opts{u}) {
    @ARGV == 0 or usage('no version version numbers should be specified');
    # fake to stop warnings when calculating $oldx etc
    @ARGV = qw(99.99.99 99.99.99);
}
elsif ($opts{c}) {
    @ARGV == 1 or usage('required one version number');
    push @ARGV, $ARGV[0];
}
else {
    @ARGV == 2 or usage('require two version numbers');
}
usage('only one of -c, -s, -u and -i') if keys %opts > 1;

my ($oldx, $oldy, $oldz) = $ARGV[0] =~ /^(\d+)\.(\d+)\.(\d+)$/
	or usage("bad version: $ARGV[0]");
my ($newx, $newy, $newz) = $ARGV[1] =~ /^(\d+)\.(\d+)\.(\d+)$/
	or usage("bad version: $ARGV[1]");

my $old_decimal = sprintf "%d.%03d%03d", $oldx, $oldy, $oldz; # 5.011001

# each entry is
#   0 a regexp that matches strings that might contain versions;
#   1 a sub that returns two strings based on $1 etc values:
#     * string containing captured values (for -c)
#     * a string containing the replacement value
#   2 what we expect the sub to return as its first arg; undef implies
#     don't match
#   3 a regex restricting which files this applies to (undef is all files)
#
# Note that @maps entries are checks in order, and only the first to match
# is used.

my @maps =  (
    [
	qr{^((?:api_)?version(?:=|\s+)'?) (\d+) ('?) (?!\.)}x,
	sub { $2, "$1$newy$3" },
	$oldy,
	qr/config/,
    ],
    [
	qr{^(subversion(?:=|\s+)'?) (\d+) ('?)  (?!\.)}x,
	sub { $2, "$1$newz$3" },
	$oldz,
	qr/config/,
    ],
    [
	qr{^(api_subversion(?:=|\s+)'?) (\d+) ('?)  (?!\.)}x,
	sub { $2, ($newy % 2) ? "$1$newz$3" : "${1}0$3" },
	($oldy % 2) ? $oldz : 0,
	qr/config/,
    ],
    [
	qr{^(api_versionstring(?:=|\s+)'?) ([\d\.]+) ('?) (?!\.)}x,
	sub { $2, ($newy % 2) ? "$1$newx.$newy.$newz$3": "$1$newx.$newy.0$3" },
	($oldy % 2) ? "$oldx.$oldy.$oldz" : "$oldx.$oldy.0",
	qr/config/,
    ],
    [
	qr{(version\s+'?) (\d+) ('?\s+subversion\s+'?) (\d+) ('?)  (?!\.)}x,
	sub { "$2-$4", "$1$newy$3$newz$5" },
	"$oldy-$oldz",
	qr/config/,
    ],
    [
	qr{\b (PERL_(?:API_)?VERSION(?:=|\s+)'?) (\d+) ('?)  (?!\.)}x,
	sub { $2, "$1$newy$3"},
	$oldy,
    ],
    [
	qr{\b (PERL_SUBVERSION(?:=|\s+)'?) (\d+) ('?)  (?!\.)}x,
	sub { $2, "$1$newz$3"},
	($oldy % 2) ? $oldz : 0,
    ],
    [
	qr{\b (PERL_API_SUBVERSION(?:=|\s+)'?) (\d+) ('?)  (?!\.)}x,
	sub { $2, ($newy % 2) ? "$1$newz$3" : "${1}0$3" },
	$oldz,
    ],
    # these two formats are in README.vms
    [
	qr{\b perl-(\d+\^\.\d+\^\.\d+) \b}x,
	sub { $1, "perl-$newx^.$newy^.$newz"},
	undef,
    ],
    [
	qr{\b ($oldx _ $oldy _$oldz) \b}x,
	sub { $1, ($newx . '_' . $newy . '_' . $newz)},
	undef,
    ],
    # 5.8.9
    [
	qr{ $oldx\.$oldy\.$oldz \b}x,
	sub {"", "$newx.$newy.$newz"},
	undef,
    ],

    # 5.008009
    [
	qr{ $old_decimal \b}x,
	sub {"", sprintf "%d.%03d%03d", $newx, $newy, $newz },
	undef,
    ],

    # perl511, perl511.dll, perl511.lib, perl511s.lib, libperl511.a
    [
	qr{\b ((?:lib)?) perl (\d\d\d) (s?) \b }x,
	sub {$2, "$1perl$newx$newy$3" },
	"$oldx$oldy",
	qr/win32|hints/,      # README.win32, win32/*, hints/*
    ],

    # microperl locations should be bumped for major versions
    [
        qr{(/)(\d\.\d{2})(["'/])},
        sub { $2, "$1$newx.$newy$3" },
        "$oldx.$oldy",
        qr/uconfig/,
    ],

);


# files and dirs that we likely don't want to change version numbers on.

my %SKIP_FILES = map { ($_ => 1) } qw(
    Changes
    MANIFEST
    Porting/Maintainers.pl
    Porting/acknowledgements.pl
    Porting/corelist-perldelta.pl
    Porting/epigraphs.pod
    Porting/how_to_write_a_perldelta.pod
    Porting/release_managers_guide.pod
    Porting/release_schedule.pod
    Porting/bump-perl-version
    pp_ctl.c
);
my @SKIP_DIRS = qw(
    ext
    lib
    pod
    cpan
    t
);

my @mani_files = sort keys %{ExtUtils::Manifest::maniread('MANIFEST')};
my %mani_files = map { ($_ => 1) } @mani_files;
die "No entries found in MANIFEST; aborting\n" unless @mani_files;

if ($opts{c} or $opts{s} or $opts{i}) {
    do_scan();
}
elsif ($opts{u}) {
    do_update();
}
else {
    usage('one of -c, -s or -u must be specified');
}
exit 0;




sub do_scan {
    for my $file (@mani_files) {
	next if grep $file =~ m{$_/}, @SKIP_DIRS;
	if ($SKIP_FILES{$file}) {
	    warn "(skipping $file)\n";
	    next;
	}
	open my $fh, '<', $file;
	my $header = 0;
	my @stat = stat $file;
	my $mode = $stat[2];
	my $file_changed = 0;
	my $new_contents = '';

	while (my $line = <$fh>) {
	    my $oldline = $line;
	    for my $map (@maps) {
		my ($pat, $sub, $expected, $file_pat) = @$map;

		next if defined $file_pat and $file !~ $file_pat;
		next unless $line =~ $pat;
		my ($got, $replacement) = $sub->();

		if ($opts{c}) {
		    # only report unexpected 
		    next unless defined $expected and $got ne $expected;
		}
		$line =~ s/$pat/$replacement/
		    or die "Internal error: substitution failed: [$pat]\n";
	    }
	    $new_contents .= $line if $opts{i};
	    if ($line ne $oldline) {
		$file_changed = 1;
		if ($opts{s}) {
		    print "\n$file\n" unless $header;
		    $header=1;
		    printf "\n%5d: -%s       +%s", $., $oldline, $line;
		}
	    }
	}
	if ($opts{i} && $file_changed) {
	    warn "Updating $file inplace\n";
	    open my $fh, '>', $file;
	    binmode $fh;
	    print $fh $new_contents;
	    close $fh;
	    chmod $mode & 0777, $file;
	}
    }
    warn "(skipped  $_/*)\n" for @SKIP_DIRS;
}

sub do_update {

    my %changes;
    my $file;
    my $line;

    # read in config

    while (<STDIN>) {
	next unless /\S/;
	if (/^(\S+)$/) {
	    $file = $1;
	    die "No such file in MANIFEST: '$file'\n" unless $mani_files{$file};
	    die "file already seen; '$file'\n" if exists $changes{$file};
	    undef $line;
	}
	elsif (/^\s+(\d+): -(.*)/) {
	    my $old;
	    ($line, $old) = ($1,$2);
	    die "$.: old line without preceding filename\n"
			    unless defined $file;
	    die "Dup line number: $line\n" if exists $changes{$file}{$line};
	    $changes{$file}{$line}[0] = $old;
	}
	elsif (/^\s+\+(.*)/) {
	    my $new = $1;
	    die "$.: replacement line seen without old line\n" unless $line;
	    $changes{$file}{$line}[1] = $new;
	    undef $line;
	}
	else {
	    die "Unexpected line at ;line $.: $_\n";
	}
    }

    # suck in file contents to memory, then update that in-memory copy

    my %contents;
    for my $file (sort keys %changes) {
	open my $fh, '<', $file;
	binmode $fh;
	$contents{$file} = [ <$fh> ];
	chomp @{$contents{$file}};
	close $fh;

	my $entries = $changes{$file};
	for my $line (keys %$entries) {
	    die "$file: no such line: $line\n"
		    unless defined $contents{$file}[$line-1];
	    if ($contents{$file}[$line-1] ne $entries->{$line}[0]) {
		die "$file: line mismatch at line $line:\n"
			. "File:   [$contents{$file}[$line-1]]\n"
			. "Config: [$entries->{$line}[0]]\n"
	    }
	    $contents{$file}[$line-1] = $entries->{$line}[1];
	}
    }

    # check the temp files don't already exist

    for my $file (sort keys %contents) {
	my $nfile = "$file-new";
	die "$nfile already exists in MANIFEST; aborting\n"
	    if $mani_files{$nfile};
    }

    # write out the new files

    for my $file (sort keys %contents) {
	my $nfile = "$file-new";
	open my $fh, '>', $nfile;
	binmode $fh;
	print $fh $_, "\n" for @{$contents{$file}};
	close $fh;

	my @stat = stat $file;
	my $mode = $stat[2];
	die "stat $file fgailed to give a mode!\n" unless defined $mode;
	chmod $mode & 0777, $nfile;
    }

    # and rename them

    for my $file (sort keys %contents) {
	my $nfile = "$file-new";
	warn "updating $file ...\n";
	rename $nfile, $file;
    }
}