#!/usr/bin/python

"""fixapplepython23 - Fix Apple-installed Python 2.3 (on Mac OS X 10.3)

Python 2.3 (and 2.3.X for X<5) have the problem that building an extension

for a framework installation may accidentally pick up the framework

of a newer Python, in stead of the one that was used to build the extension.

This script modifies the Makefile (in .../lib/python2.3/config) to use

the newer method of linking extensions with "-undefined dynamic_lookup"

which fixes this problem.

The script will first check all prerequisites, and return a zero exit

status also when nothing needs to be fixed.

"""

import sys

import os

import gestalt

MAKEFILE='/System/Library/Frameworks/Python.framework/Versions/2.3/lib/python2.3/config/Makefile'

CHANGES=((

    'LDSHARED=\t$(CC) $(LDFLAGS) -bundle -framework $(PYTHONFRAMEWORK)\n',

    'LDSHARED=\t$(CC) $(LDFLAGS) -bundle -undefined dynamic_lookup\n'

    ),(

    'BLDSHARED=\t$(CC) $(LDFLAGS) -bundle -framework $(PYTHONFRAMEWORK)\n',

    'BLDSHARED=\t$(CC) $(LDFLAGS) -bundle -undefined dynamic_lookup\n'

    ),(

    'CC=\t\tgcc\n',

    'CC=\t\t/System/Library/Frameworks/Python.framework/Versions/2.3/lib/python2.3/config/PantherPythonFix/run-gcc\n'

    ),(

    'CXX=\t\tc++\n',

    'CXX=\t\t/System/Library/Frameworks/Python.framework/Versions/2.3/lib/python2.3/config/PantherPythonFix/run-g++\n'

))

GCC_SCRIPT='/System/Library/Frameworks/Python.framework/Versions/2.3/lib/python2.3/config/PantherPythonFix/run-gcc'

GXX_SCRIPT='/System/Library/Frameworks/Python.framework/Versions/2.3/lib/python2.3/config/PantherPythonFix/run-g++'

SCRIPT="""#!/bin/sh

export MACOSX_DEPLOYMENT_TARGET=10.3

exec %s "${@}"

"""

def findline(lines, start):

    """return line starting with given string or -1"""

    for i in range(len(lines)):

        if lines[i][:len(start)] == start:

            return i

    return -1

def fix(makefile, do_apply):

    """Fix the Makefile, if required."""

    fixed = False

    lines = open(makefile).readlines()

    for old, new in CHANGES:

        i = findline(lines, new)

        if i >= 0:

            # Already fixed

            continue

        i = findline(lines, old)

        if i < 0:

            print 'fixapplepython23: Python installation not fixed (appears broken)'

            print 'fixapplepython23: missing line:', old

            return 2

        lines[i] = new

        fixed = True

    if fixed:

        if do_apply:

            print 'fixapplepython23: Fix to Apple-installed Python 2.3 applied'

            os.rename(makefile, makefile + '~')

            open(makefile, 'w').writelines(lines)

            return 0

        else:

            print 'fixapplepython23: Fix to Apple-installed Python 2.3 should be applied'

            return 1

    else:

        print 'fixapplepython23: No fix needed, appears to have been applied before'

        return 0

def makescript(filename, compiler):

    """Create a wrapper script for a compiler"""

    dirname = os.path.split(filename)[0]

    if not os.access(dirname, os.X_OK):

        os.mkdir(dirname, 0755)

    fp = open(filename, 'w')

    fp.write(SCRIPT % compiler)

    fp.close()

    os.chmod(filename, 0755)

    print 'fixapplepython23: Created', filename

def main():

    # Check for -n option

    if len(sys.argv) > 1 and sys.argv[1] == '-n':

        do_apply = False

    else:

        do_apply = True

    # First check OS version

    if sys.byteorder == 'little':

        # All intel macs are fine

        print "fixapplypython23: no fix is needed on MacOSX on Intel"

        sys.exit(0)

    if gestalt.gestalt('sysv') < 0x1030:

        print 'fixapplepython23: no fix needed on MacOSX < 10.3'

        sys.exit(0)

    if gestalt.gestalt('sysv') >= 0x1040:

        print 'fixapplepython23: no fix needed on MacOSX >= 10.4'

        sys.exit(0)

    # Test that a framework Python is indeed installed

    if not os.path.exists(MAKEFILE):

        print 'fixapplepython23: Python framework does not appear to be installed (?), nothing fixed'

        sys.exit(0)

    # Check that we can actually write the file

    if do_apply and not os.access(MAKEFILE, os.W_OK):

        print 'fixapplepython23: No write permission, please run with "sudo"'

        sys.exit(2)

    # Create the shell scripts

    if do_apply:

        if not os.access(GCC_SCRIPT, os.X_OK):

            makescript(GCC_SCRIPT, "gcc")

        if not os.access(GXX_SCRIPT, os.X_OK):

            makescript(GXX_SCRIPT, "g++")

    #  Finally fix the makefile

    rv = fix(MAKEFILE, do_apply)

    #sys.exit(rv)

    sys.exit(0)

if __name__ == '__main__':

    main()