./args.py foo bar -o baz -c qaz
   input: qaz
   output: baz
   parser_args: ['foo', 'bar']

./args.py foo bar -c -o baz qaz
   input: qaz
   output: baz
   parser_args: ['foo', 'bar']

#!/usr/bin/env python

import sys

def help():
    print """
    This tool takes command line arguments in a way compatible with gcc. This is
    so that it can be compatible with ccache.

    Pass with -c the path to the rtdv file.
    Pass with -o the output path to the json file.
    All other args are forwarded to libclang.


    To accomodate ccache, the following syntax is also allowed:
      -c -o output input
"""


def parse_cl_args(argv):
    input = False
    output = False
    parser_args = []

    i = 1
    while i < len(argv):
        # When we see -c, go into a mode where next parameter is the source file,
        # except that -o and its argument are allowed to appear inbetween
        if argv[i] == '-c':
            i+=1
            # Consume any -o immediately after -c
            while argv[i] == '-o':
                if output:
                    raise Exception("Too many output files specified: " + output + " , " + argv[i+1])
                output = argv[i+1]
                i+=2

            # Consume -c parameter as input file
            if input:
                raise Exception("Too many input files specified: " + input + " , " + argv[i])
            input = argv[i]
            i+=1
        elif argv[i] == '-o':
            if output:
                raise Exception("Too many output files specified: " + output + " , " + argv[i+1])
            output = argv[i+1]
            i+=2
        else:
            parser_args += [argv[i]]
            i+=1

    return (input, output, parser_args)

def main():
    if '-h' in sys.argv or '--help' in sys.argv or len(sys.argv) <= 1:
         help()
         return

    (input, output, parser_args) = parse_cl_args(sys.argv)

#    if not input:
#        sys.stderr.write('Argv: ' + str(sys.argv) + 'n')
#        raise Exception("Must use -c flag to specify dv file to parse.")
#
#    if not output:
#        sys.stderr.write('Argv: ' + str(sys.argv) + 'n')
#        raise Exception("Must use -o flag to specify output path for json")

    print 'input: ', input
    print 'output: ', output
    print 'parser_args: ', parser_args

if __name__ == '__main__':
    main()