#!/sprite/cmds/perl

if ($#ARGV != 1) {
    printf("$#ARGV\n");
    printf("Usage: kdiff oldKernel newKernel\n");
    exit;
}
if (! -e $ARGV[0]) {
    die("File $ARGV[0] does not exist.\n");
}
if (! -e $ARGV[1]) {
    die("File $ARGV[1] does not exist.\n");
}
open(fid, "strings $ARGV[0] |") || die ("Can't open pipe.\n");
while (<fid>) {
    if (/RCS/) {
	($d1,$file, $version) = split;
	$versionArray{$file} = $version;
    }
}

open(fid, "strings $ARGV[1] |") || die ("Can't open pipe.\n");
while (<fid>) {
    if (/RCS/) {
	($d1, $file, $version) = split;
	if (! defined($versionArray{$file})) {
	    $#newFiles++;
	    $newFiles[$#newFiles] = $file;
	} elsif ($version != $versionArray{$file}) {
	    do SaveLog($file, $versionArray{$file}, $version);
	}
	$used{$file} = 1;
    }
}
&PrintLog();
if ($#newFiles > 0) {
    printf("\nThe following files were added to the new kernel:\n\n");
    for ($i = 0; $i <= $#newFiles; $i++) {
	printf("$newFiles[$i]\n");
    }
}

$headerPrinted = 0;
while (($file, $version) = each(%versionArray)) {
    if (! defined($used{$file})) {
	if ($headerPrinted == 0) {
	    printf(
	"\nThe following files were not used in the new kernel:\n\n");
	    $headerPrinted = 1;
	}
	printf("$file\n");
    }
}

sub SaveLog {
    local($stream);
    local($start) = 0;
    local($comment) = "";
    local($file) = $_[0];
    local($oldVersion) = $_[1];
    local($newVersion) = $_[2];
    open($stream, "rlog $file |") || die("Can't rlog $file\n");
    while (<$stream>) {
	($f1, $f2, $f3, $f4, $f5) = split(' ');
	if (/^revision/) {
	    if ($f2 eq $newVersion) {
		$start = 1;
	    } elsif ($f2 eq $oldVersion) {
		if ($start == 0) {
		    printf("File: $file\n");
		    printf("New version %s appears older than old version %s\n",
			$newVersion, $oldVersion);
		    printf("Were the kernel arguments in the correct order?\n");
		} else {
		    $changes{$comment} = $changes{$comment} . $file . "\n";
		}
		last;
	    }
	    next;
	}
	if (/^date:/) {
	    $_ = "$f2 $f5\n";
	} elsif (/^[-]+$/) {
	    next;
	}
	if ($start) {
	    $comment = $comment . $_;
	}
    }
}

sub PrintLog {
    foreach $comment (keys %changes) {
	printf("-------------------------------\n");
	printf($changes{$comment});
	printf($comment);
    }
}