# Compares classpaths from ant -v logfiles
# Useful for debugging errors in ant build scripts,
# where a build typically works on one machine and not another

import sys, os
from optparse import OptionParser
from sets import Set
import re

# Build dirs are different on machines
# /src/SABS/build or /home/hendry/SABS/build or /u01/build/SABS/build
# With '^.*SABS/' we strip all the above to the same build/ for comparison
prefix = '^.*SABS/'

# Regex for choosing what you do not want to see in the output
exclude = 'ant|tools.jar'

debug = 1

def win32file(line):
    win32 = re.search(r"\r\n", line)
    if win32:
        return 1
    else:
        return 0 

def compare(classpath1, classpath2):

    # Assuming UNIX style
    delimiter = ':'
    sep = "/"

    # Make sure classpath1 is the larger
    if len(classpath1) < len(classpath2):
        tmp = classpath1
        classpath1 = classpath2
        classpath2 = tmp
        tmp = None

    if debug: 
        print "Length of 1: %d" % len(classpath1)
        print "Length of 2: %d" % len(classpath2)
        print
    
    classpath2length = len(classpath2) + 1

    classes1 = Set([])
    classes2 = Set([])

    # Classpath with least classpath defs is loaded up first
    # This is the one which most likely bombed out of the compile
    # And requires comparing to at each stage

    for i in classpath2:
        j = i.split(delimiter)
        for jar in j: 
            jar = re.sub(prefix, '', jar)
            classes2.add(jar)
        print "Adding %d values to classes2 of size %d" % (len(j), len(classes2))

    print "Classpath2 loaded for comparison"

    for i in classpath1:
        classpath2length = classpath2length - 1
        if not classpath2length:
            print '*'*25
            print "Critical stage"
            print '*'*25, '\n'
        j = i.split(delimiter)
        for jar in j: 
            jar = re.sub(prefix, '', jar)
            classes1.add(jar)
        print "Adding %d values to classes1 of size %d and comparing to classes2 of size %d" % (len(j), len(classes1), len(classes2))
        print "What they share:"
        for i in (classes1 & classes2):
            display(i)
        print
        print "What classes1 has that classes2 doesn't:"
        for i in (classes1 - classes2):
            display(i)
        print
        print "What classes2 has that classes1 doesn't:"
        for i in (classes2 - classes1):
            display(i)
        print
        print

def display(i):
    if not re.search(exclude, i):
        print i

def grabclasspath(input):
    """ Grabs classpaths from Ant log """
    s = re.findall(r"classpath\'\s+\[javac\]\s+'(.*)'\s+\[javac\]\s\'\-sourcepath", input)
    if s:
        return s
    else:
        print "No classpath(s) found!"
        sys.exit(1)

def main():
    usage = "Usage: %prog [options] classes"
    parser = OptionParser(usage, version="%prog $Id$ ")

    (options, args) = parser.parse_args()

    if len(args) == 2:

        classpath1 = open(args[0]).read()
        classpath2 = open(args[1]).read()

        compare(grabclasspath(classpath1), grabclasspath(classpath2))

if __name__ == '__main__':
    main()