pyvix2/get_enum.py

The C-language API depends on a large number of enumerated constants.

In order to be absolutely sure that the current values are used, this script extracts the values from the vix.h header.

Overheads

from __future__ import print_function
import datetime
import sys

File Processing

We create an iterator to visit source stripped of leading and trailing whitespace.

The interesting enum lines are (fortunately) easy to find. Further, each enumerated name has an explicit value, saving us from really parsing the source.

def get_enum( source, target ):
    """Get VIX enum values.
    :param source: Source file-like object, usually :samp:`open("vix.h","r")`.
    :param target: Target file-like object, usually :samp:`open("pyvix2/enum.py","w")`.
    """
    print( '"""{2!r} created {0} from {1!r}"""'.format(
            datetime.datetime.now(), source.name, target.name ),
        file= target )

    source_iter= (l.strip() for l in source)
    for line in source_iter:

        if line.startswith( "enum" ):
            for line in source_iter:
                # end of enum?
                if line.endswith( "};" ): break

                # C++ comments?
                line, delim, text = line.partition( '//' )

                # Block comments?
                if line.startswith('/*'):
                    print( '#', line, file=target )
                    if '*/' not in line:
                        for line in source_iter:
                            print( '#', line, file=target )
                            if '*/'  in line: break
                    continue

                # Finally, the values.
                if line.endswith(','):
                    words= line[:-1].split()
                else:
                    words= line.split()
                assert len(words) == 0 or (len(words) == 3 and words[1] == "=")
                print( ' '.join(words), file=target )

        else:
            pass # non-enum lines

    print( '# Finished.', file=target )

Main-Import Switch

This allows us to either execute this module or import the relevant function.

def main():
    if sys.platform.startswith("win"):
        vix_h= r"C:\Program Files\VMware\VMware VIX\vix.h"
    else:
        vix_h= "/usr/lib/vmware-vix/lib/vix.h"
    with open( vix_h, "r" ) as source:
        with open( "pyvix2/enum.py", "w" ) as target:
        #with sys.stdout as target:
            get_enum(source, target)
            print( "get_enum created {1!r}".format( source.name, target.name ) )

if __name__ == "__main__":
    main()