mercurial/packagescan.py

setup.py: install packagescan before any mercurial modules is imported

Further the installation of packagescan over demandload is moved to the
packagescan module.

I added as well few more comments in the packagescan module to avoid
the wrong use of package scan in the future.

Reason:

mercurial.packagescan acts as fake mercurial.demandload during a py2exe
run.  Unfortunatly the import of mercurial.version in setup.py is done
before mercurial.packagescan is installed. This results in few imports
without mercurial.packagescan in charge and therefore not all dependend
modules are detected when running mercurial.packagescan.getmodules
later e.g.  winerror is missed.

# packagescan.py - Helper module for identifing used modules.
# Used for the py2exe distutil.
# This module must be the first mercurial module imported in setup.py
#
# Copyright 2005 Volker Kleinfeld <[e-mail]>
#
# This software may be used and distributed according to the terms
# of the GNU General Public License, incorporated herein by reference.
import glob
import os
import sys
import ihooks

# Install this module as fake demandload module
sys.modules['mercurial.demandload'] = sys.modules[__name__]

# Requiredmodules contains the modules imported by demandload.
# Please note that demandload can be invoked before the 
# mercurial.packagescan.scan method is invoked in case a mercurial
# module is imported.
requiredmodules = {} 
def demandload(scope, modules):
    """ fake demandload function that collects the required modules """
    for m in modules.split():
        mod = None
        try:
            module, submodules = m.split(':')
            submodules = submodules.split(',')
        except:
            module = m
            submodules = []
        mod = __import__(module, scope, scope, submodules)
        scope[module] = mod
        requiredmodules[mod.__name__] = 1

def scan(libpath,packagename):
    """ helper for finding all required modules of package <packagename> """
    # Use the package in the build directory
    libpath = os.path.abspath(libpath)
    sys.path.insert(0,libpath)
    packdir = os.path.join(libpath,packagename)
    # A normal import would not find the package in
    # the build directory. ihook is used to force the import.
    # After the package is imported the import scope for
    # the following imports is settled.
    p = importfrom(packdir)
    globals()[packagename] = p
    sys.modules[packagename] = p
    # Fetch the python modules in the package
    cwd = os.getcwd()
    os.chdir(packdir)
    pymodulefiles = glob.glob('*.py')
    extmodulefiles = glob.glob('*.pyd')
    os.chdir(cwd)
    # Import all python modules and by that run the fake demandload
    for m in pymodulefiles:
        if m == '__init__.py': continue
        tmp = {}
        mname,ext = os.path.splitext(m)
        fullname = packagename+'.'+mname
        __import__(fullname,tmp,tmp)
        requiredmodules[fullname] = 1
    # Import all extension modules and by that run the fake demandload
    for m in extmodulefiles:
        tmp = {}
        mname,ext = os.path.splitext(m)
        fullname = packagename+'.'+mname
        __import__(fullname,tmp,tmp)
        requiredmodules[fullname] = 1

def getmodules():
    return requiredmodules.keys()

def importfrom(filename):
    """
    import module/package from a named file and returns the module.
    It does not check on sys.modules or includes the module in the scope.
    """
    loader = ihooks.BasicModuleLoader()
    path, file = os.path.split(filename)
    name, ext  = os.path.splitext(file)
    m = loader.find_module_in_dir(name, path)
    if not m:
        raise ImportError, name
    m = loader.load_module(name, m)
    return m