#! /usr/bin/perl

# Generate variants of parallel_schedule file to verify that there are
# no order dependencies between tests executed in parallel.

# Usage: sched_variants input_file output_prefix

# Output files are named with 'output_prefix' suffixed .1, .2, etc.

die "Usage: sched_variants input_file output_prefix\n" if ($#ARGV != 1);

$infile = $ARGV[0];
$outprefix = $ARGV[1];

$outcount = 0;			# number of output files created

# We scan the input file repeatedly.  On each pass we generate two
# output files, one where the k'th entry of each parallel test set
# has been extracted and forced to run first, and one where it's been
# forced to run last.  The number of passes needed is the same as the
# largest number of tests in a parallel test set.

$k = 1;				# test index we are currently hacking

$more = 1;			# true if we need another pass

while ($more) {
    $more = 0;			# until proven differently

    open(INFILE, $infile) || die "$infile: $!\n";

    $outcount++;
    $outbefore = $outprefix . "." . $outcount;
    open(OUTBEFORE, "> $outbefore") || die "$outbefore: $!\n";

    $outcount++;
    $outafter = $outprefix . "." . $outcount;
    open(OUTAFTER, "> $outafter") || die "$outafter: $!\n";

    while (<INFILE>) {
	if (! /^test:/) {
	    # comment line
	    print OUTBEFORE $_;
	    print OUTAFTER $_;
	    next;
	}
	@tests = split;
	shift(@tests);		# remove test:
	if ($#tests < $k-1 || $#tests == 0) {
	    # too few tests in this set, just repeat as-is
	    print OUTBEFORE $_;
	    print OUTAFTER $_;
	    next;
	}
	if ($#tests >= $k) {
	    $more = 1;		# need more passes to process this set
	}
	@thistest = splice(@tests, $k-1, 1);
	print OUTBEFORE "test: @thistest\n";
	print OUTBEFORE "test: @tests\n";

	print OUTAFTER "test: @tests\n";
	print OUTAFTER "test: @thistest\n";
    }

    close OUTBEFORE;
    close OUTAFTER;
    close INFILE;

    $k++;
}

print "$outcount test files generated.\n";

exit 0;