#! perl
# urm.pl
# 2003 (c) by Marcus Thiesen
# Maybe you can use it for debugging
# Copyright (C) 2003-2006, The Perl Foundation.
# $Id: urm-old.pl 21250 2007-09-13 06:33:53Z paultcochrane $

use strict;
use warnings;
use Data::Dumper;

my @program;
my %register;
my $outreg;
open PROGRAM, '<', $ARGV[0] or die "Couldn't get file";
foreach my $line (<PROGRAM>) {
    chomp $line;
    next if ( $line =~ /^ *\#/ );
    if ( $line =~ /in *\(([r\d,]+)\)/ ) {
        print "Werte für $1: ";
        my $input = readline(STDIN);
        my @register = split( ",", $1 );
        chomp $input;
        my @input = split( ",", $input );
        foreach my $reg (@register) {
            $register{$reg} = shift @input;
        }
    }
    if ( $line =~ /(r\d+)/ ) { $register{$1} = 0 unless defined $register{$1} }
    if ( $line =~ /out\((r\d+)/ ) { $outreg = $1 }
    if ( $line =~ /^\d+:(.+)/ ) {
        my $code = $1;

        # Some beautification!
        $code =~ s/ +/ /g;
        $code =~ s/\#.*//g;
        next unless $code;
        push @program, $code;
    }
}
close PROGRAM;

#print Dumper @program;

my $pos = 1;
while (1) {
    my $line = $program[ $pos - 1 ];
    if ( $pos > @program ) { last; }
    print "($pos";
    foreach my $reg ( sort keys %register ) {
        print ", " . $register{$reg};
    }
    print ") \t$line\n";
    if ( $line =~ /if *(r\d) *= *(\d) *goto *(\d+)/ ) {
        $register{$1} = 0 unless defined $register{$1};
        if ( $register{$1} == $2 ) { $pos = $3; }
        else { $pos++ }
    }
    elsif ( $line =~ /(r\d) *<- *(\d+)/ ) {
        $register{$1} = $2;
        $pos++;
    }
    elsif ( $line =~ /(r\d) *<- *(r\d+) *([+-]) *1/ ) {
        if ( $1 ne $2 ) { print "Syntax error: Registers don't match!\n"; exit 1; }
        $register{$1} = eval("$register{$2} $3 1;");
        if ( $register{$1} < 0 ) { $register{$1} = 0 }
        $pos++;
    }
    elsif ( $line =~ / *goto *(\d+)/ ) {
        $pos = $1;
    }
    else {
        print "Syntax error\n";
        exit;
    }
}

print "Output: $register{$outreg}\n";

#print Dumper %register;

# Local Variables:
#   mode: cperl
#   cperl-indent-level: 4
#   fill-column: 100
# End:
# vim: expandtab shiftwidth=4: