Lib/distutils/core.py

"""distutils.core

The only module that needs to be imported to use the Distutils; provides
the 'setup' function (which is to be called from the setup script).  Also
indirectly provides the Distribution and Command classes, although they are
really defined in distutils.dist and distutils.cmd.
"""

# created 1999/03/01, Greg Ward

__revision__ = "$Id$"

import sys, os
from types import *
from distutils.errors import *
from distutils.util import grok_environment_error

# Mainly import these so setup scripts can "from distutils.core import" them.
from distutils.dist import Distribution
from distutils.cmd import Command
from distutils.extension import Extension


# This is a barebones help message generated displayed when the user
# runs the setup script with no arguments at all.  More useful help
# is generated with various --help options: global help, list commands,
# and per-command help.
USAGE = """\
usage: %(script)s [global_opts] cmd1 [cmd1_opts] [cmd2 [cmd2_opts] ...]
   or: %(script)s --help [cmd1 cmd2 ...]
   or: %(script)s --help-commands
   or: %(script)s cmd --help
"""


# If DISTUTILS_DEBUG is anything other than the empty string, we run in
# debug mode.
DEBUG = os.environ.get('DISTUTILS_DEBUG')

def gen_usage (script_name):
    script = os.path.basename(script_name)
    return USAGE % vars()


# Some mild magic to control the behaviour of 'setup()' from 'run_setup()'.
_setup_stop_after = None
_setup_distribution = None


def setup (**attrs):
    """The gateway to the Distutils: do everything your setup script needs
    to do, in a highly flexible and user-driven way.  Briefly: create a
    Distribution instance; find and parse config files; parse the command
    line; run each Distutils command found there, customized by the options
    supplied to 'setup()' (as keyword arguments), in config files, and on
    the command line.

    The Distribution instance might be an instance of a class supplied via
    the 'distclass' keyword argument to 'setup'; if no such class is
    supplied, then the Distribution class (in dist.py) is instantiated.
    All other arguments to 'setup' (except for 'cmdclass') are used to set
    attributes of the Distribution instance.

    The 'cmdclass' argument, if supplied, is a dictionary mapping command
    names to command classes.  Each command encountered on the command line
    will be turned into a command class, which is in turn instantiated; any
    class found in 'cmdclass' is used in place of the default, which is
    (for command 'foo_bar') class 'foo_bar' in module
    'distutils.command.foo_bar'.  The command class must provide a
    'user_options' attribute which is a list of option specifiers for
    'distutils.fancy_getopt'.  Any command-line options between the current
    and the next command are used to set attributes of the current command
    object.

    When the entire command-line has been successfully parsed, calls the
    'run()' method on each command object in turn.  This method will be
    driven entirely by the Distribution object (which each command object
    has a reference to, thanks to its constructor), and the
    command-specific options that became attributes of each command
    object.
    """

    global _setup_stop_after, _setup_distribution

    # Determine the distribution class -- either caller-supplied or
    # our Distribution (see below).
    klass = attrs.get('distclass')
    if klass:
        del attrs['distclass']
    else:
        klass = Distribution

    if not attrs.has_key('script_name'):
        attrs['script_name'] = sys.argv[0]
    if not attrs.has_key('script_args'):
        attrs['script_args'] = sys.argv[1:]

    # Create the Distribution instance, using the remaining arguments
    # (ie. everything except distclass) to initialize it
    try:
        _setup_distribution = dist = klass(attrs)
    except DistutilsSetupError, msg:
        raise SystemExit, "error in setup script: %s" % msg

    if _setup_stop_after == "init":
        return dist

    # Find and parse the config file(s): they will override options from
    # the setup script, but be overridden by the command line.
    dist.parse_config_files()
    
    if DEBUG:
        print "options (after parsing config files):"
        dist.dump_option_dicts()

    if _setup_stop_after == "config":
        return dist

    # Parse the command line; any command-line errors are the end user's
    # fault, so turn them into SystemExit to suppress tracebacks.
    try:
        ok = dist.parse_command_line()
    except DistutilsArgError, msg:
        script = os.path.basename(dist.script_name)
        raise SystemExit, \
              gen_usage(dist.script_name) + "\nerror: %s" % msg

    if DEBUG:
        print "options (after parsing command line):"
        dist.dump_option_dicts()

    if _setup_stop_after == "commandline":
        return dist

    # And finally, run all the commands found on the command line.
    if ok:
        try:
            dist.run_commands()
        except KeyboardInterrupt:
            raise SystemExit, "interrupted"
        except (IOError, os.error), exc:
            error = grok_environment_error(exc)

            if DEBUG:
                sys.stderr.write(error + "\n")
                raise
            else:
                raise SystemExit, error
            
        except (DistutilsExecError,
                DistutilsFileError,
                DistutilsOptionError,
                CCompilerError), msg:
            if DEBUG:
                raise
            else:
                raise SystemExit, "error: " + str(msg)

    return dist

# setup ()


def run_setup (script_name, script_args=None, stop_after="run"):
    """Run a setup script in a somewhat controlled environment, and
    return the Distribution instance that drives things.  This is useful
    if you need to find out the distribution meta-data (passed as
    keyword args from 'script' to 'setup()', or the contents of the
    config files or command-line.

    'script_name' is a file that will be run with 'execfile()';
    'sys.argv[0]' will be replaced with 'script' for the duration of the
    call.  'script_args' is a list of strings; if supplied,
    'sys.argv[1:]' will be replaced by 'script_args' for the duration of
    the call.

    'stop_after' tells 'setup()' when to stop processing; possible
    values:
      init
        stop after the Distribution instance has been created and
        populated with the keyword arguments to 'setup()'
      config
        stop after config files have been parsed (and their data
        stored in the Distribution instance)
      commandline
        stop after the command-line ('sys.argv[1:]' or 'script_args')
        have been parsed (and the data stored in the Distribution)
      run [default]
        stop after all commands have been run (the same as if 'setup()'
        had been called in the usual way

    Returns the Distribution instance, which provides all information
    used to drive the Distutils.
    """
    if stop_after not in ('init', 'config', 'commandline', 'run'):
        raise ValueError, "invalid value for 'stop_after': %s" % `stop_after`

    global _setup_stop_after, _setup_distribution
    _setup_stop_after = stop_after

    save_argv = sys.argv
    g = {}
    l = {}
    try:
        try:
            sys.argv[0] = script_name
            if script_args is not None:
                sys.argv[1:] = script_args
            execfile(script_name, g, l)
        finally:
            sys.argv = save_argv
            _setup_stop_after = None
    except SystemExit:
        # Hmm, should we do something if exiting with a non-zero code
        # (ie. error)?
        pass
    except:
        raise

    if _setup_distribution is None:
        raise RuntimeError, \
              ("'distutils.core.setup()' was never called -- "
               "perhaps '%s' is not a Distutils setup script?") % \
              script_name

    # I wonder if the setup script's namespace -- g and l -- would be of
    # any interest to callers?
    #print "_setup_distribution:", _setup_distribution
    return _setup_distribution

# run_setup ()