#! /usr/bin/env perl
# Copyright (c) 2003-2007 The Regents of The University of Michigan
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are
# met: redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer;
# redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution;
# neither the name of the copyright holders nor the names of its
# contributors may be used to endorse or promote products derived from
# this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

# Script to simplify using rundiff on trace outputs from two
# invocations of m5.  Takes a common m5 command line with embedded
# alternatives and executes the two alternative commands in separate
# subdirectories with output piped to rundiff.
#
# ******Note that you need to enable some trace flags in the args in order
# to do anything useful!******
#
# Script arguments are handled uniformly as follows:
# - If the argument does not contain a '|' character, it is appended
#   to both command lines.
# - If the argument has a '|' character in it, the text on either side
#   of the '|' is appended to the respective command lines.  Note that
#   you'll have to quote the arg or escape the '|' with a backslash
#   so that the shell doesn't think you're doing a pipe.
# - Arguments with '#' characters are split at those characters,
#   processed for alternatives ('|'s) as independent terms, then
#   pasted back into a single argument (without the '#'s).  (Sort of
#   inspired by the C preprocessor '##' token pasting operator.)
#
# In other words, the arguments should look like the command line you
# want to run, with "|" used to list the alternatives for the parts
# that you want to differ between the two runs.
#
# For example:
#
# % tracediff m5.opt --opt1 '--opt2|--opt3' --opt4
# would compare these two runs:
# m5.opt --opt1 --opt2 --opt4
# m5.opt --opt1 --opt3 --opt4
#
# % tracediff 'path1|path2#/m5.opt' --opt1 --opt2
# would compare these two runs:
# path1/m5.opt --opt1 --opt2
# path2/m5.opt --opt1 --opt2
#
# If you want to add arguments to one run only, just put a '|' in with
# text only on one side ('--onlyOn1|').  You can do this with multiple
# arguments together too ('|-a -b -c' adds three args to the second
# run only).
#
# The '-n' argument to tracediff allows you to preview the two
# generated command lines without running them.
#

use FindBin;

$dryrun = 0;

if (@ARGV >= 1 && $ARGV[0] eq '-n') {
    $dryrun = 1;
    shift @ARGV;
}

if (@ARGV < 1) {
    die "Usage: tracediff [-n] \"sim1|sim2\" [common-arg \"arg1|arg2\" ...]\n";
}

foreach $arg (@ARGV) {
    $a1 = $a2 = '';
    @subargs = split('#', $arg);
    foreach $subarg (@subargs) {
        if ($subarg eq '') {
            next;
        }
        @pair = split('\|', $subarg, -1); # -1 enables null trailing fields
        if (@pair == 1) {
            $a1 .= $subarg;
            $a2 .= $subarg;
        } elsif (@pair == 2) {
            $a1 .= $pair[0];
            $a2 .= $pair[1];
        } else {
            print 'Parse error: too many |s in ', $arg, "\n";
            exit(1);
        }
    }

    push @cmd1, $a1;
    push @cmd2, $a2;
}


if ($dryrun) {
    print "CMD1: ", join(' ', @cmd1), "\n";
    print "CMD2: ", join(' ', @cmd2), "\n";
    exit(0);
}

# First two args are the two simulator binaries to compare
$sim1 = shift @cmd1;
$sim2 = shift @cmd2;

# Everything else is a simulator arg.
$args1 = join(' ', @cmd1);
$args2 = join(' ', @cmd2);

# Common mistake: if you don't set any debugflags this often isn't
# doing what you want.
if ($args1 !~ /--debug-flags/) {
    print "****\n";
    print "**** WARNING: no debug flags set... you may not be diffing much!\n";
    print "****\n";
}

# Run individual invocations in separate dirs so output and intermediate
# files (particularly config.py and config.ini) don't conflict.
$dir1 = "tracediff-$$-1";
$dir2 = "tracediff-$$-2";
mkdir($dir1) or die "Can't create dir $dir1\n";
mkdir($dir2) or die "Can't create dir $dir2\n";

$cmd1 = "$sim1 -d $dir1 $args1 2>&1 |";
$cmd2 = "$sim2 -d $dir2 $args2 2>&1 |";

# Expect that rundiff is in the same dir as the tracediff script.
# FindBin figures that out for us.
$fullcmd = "$FindBin::Bin/rundiff '$cmd1' '$cmd2' 2>&1 > tracediff-$$.out";

print "Executing $fullcmd\n";
system($fullcmd);