disasm-cmp

#!/usr/bin/perl

if (@ARGV < 3) {
	print STDERR "disasm-cmp <bits> <decompiler> <file>\n";
	exit 1;
}

my $bits = (shift @ARGV) + 0;
my $deco = shift @ARGV;
my $file = shift @ARGV;

die unless -x $deco;
die unless -f $file;

open(A,"./$deco '$file' -$bits |") || die;
open(B,"ndisasm -b $bits '$file' |") || die;

sub ours_filter($) {
	my @a = split(/ +/,@_[0]);
	my $ret = '',$x;

	# address
	$ret .= sprintf("0x%04X ",hex(shift @a));

	# hex opcodes
	while (@a > 0 && length($a[0]) == 2 && $a[0] =~ m/[0123456789abcdef]{2}/i) {
		$ret .= shift @a;
	}
	$ret .= "  ";

	# pad
	while (length($ret) < 40) {
		$ret .= " ";
	}

	# instructions
	while (@a > 0) {
		$x = uc(shift @a);
#		$x =~ s/(DS|ES|FS|GS|SS):\((BYTE|WORD|DWORD|QWORD)\*\)/$1:/;
		$x =~ s/0X(0|1|2|3|4|5|6|7|8|9|A|B|C|D|E|F)/0x$1/g;
		$ret .= $x;
		$ret .= ' ';
	}

	return $ret;
}

sub nasm_filter($) {
	my @a = split(/ +/,@_[0]);
	my $ret = '';

	# address
	$ret .= sprintf("0x%04X ",hex(shift @a));

	# hex opcodes
	$ret .= shift @a;
	$ret .= "  ";

	# pad
	while (length($ret) < 40) {
		$ret .= " ";
	}

	# instructions
	while (@a > 0) {
#		if ($a[0] =~ m/(BYTE|WORD|DWORD|QWORD)/i && $a[1] =~ m/^\[/) {
#			shift @a;
#			next;
#		}
		$x = uc(shift @a);
		$x =~ s/0X(0|1|2|3|4|5|6|7|8|9|A|B|C|D|E|F)/0x$1/g;
		$ret .= $x;
		$ret .= ' ';
	}

	return $ret;
}

my $line_A,$line_B;
while (1) {
	$line_B = <B>;
	next if $line_B =~ m/^ +-[0-9a-f]+/i;
	$line_A = <A>;
	last if (!$line_A && !$line_B);
	chomp $line_A; # our decompiler
	chomp $line_B; # NASM decompiler

# for comparison purposes massage both so they line up
# example:
# + OURS:0x0000  8B 04                   MOV      AX,DS:(WORD*)[SI]
#   NASM:00000000  8B04              mov ax,[si]
	$line_A = ours_filter($line_A);
	$line_B = nasm_filter($line_B);

	if ($line_A ne $line_B) {
		print ">>>>>>>>>>>>>------------------------------\n";
	}

	print "+ OURS:$line_A\n";
	print "  NASM:$line_B\n";
}

close(B);
close(A);