gen_exc.py

#!/usr/bin/env python

# Copyright 2011 Julian Phillips.  All rights reserved.
# Use of this source code is governed by a BSD-style
# license that can be found in the LICENSE file.

import re
import subprocess
import threading


header = """// Copyright 2011 Julian Phillips.  All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

// This file is automatically generated.  To regenerate:
//   ./gen_exc.py | gofmt > exc.go

package py

// #include "utils.h"
import "C"
"""

exc_re = re.compile('^extern .* PyExc_(?P<name>\w+);$')


def get_ffi_flags():
    cmd = ['pkg-config', '--cflags', 'libffi']
    p = subprocess.Popen(cmd, stdout=subprocess.PIPE)
    out, err = p.communicate()
    return out.strip().split(' ')

def get_python3_flags():
    cmd = ['python3.3-config', '--cflags']
    p = subprocess.Popen(cmd, stdout=subprocess.PIPE)
    out, err = p.communicate()
    return out.strip().split(' ')

def process(inp):
    exceptions = []
    maxlen = 0

    for rawline in inp:
        line = rawline.strip()
        excm = exc_re.match(line)
        if excm is None:
            continue
        exc = excm.group('name')
        exceptions.append(exc)
        if len(exc) > maxlen:
            maxlen = len(exc)

    print header

    print 'var ('
    for exception in exceptions:
        print '\t%s%s = newException(C.PyExc_%s)' % \
              (exception, ' ' * (maxlen - len(exception)), exception)
    print ')\n'

def main():
    cmd = ["cc", "-E", "-o", "-", "utils.c"] + get_ffi_flags() + get_python3_flags()
    p = subprocess.Popen(cmd, stdout=subprocess.PIPE)
    t = threading.Thread(target=process, args=(p.stdout,))
    t.start()
    p.wait()
    t.join()

if __name__ == "__main__":
    main()