Lib/distutils/cmd.py

"""distutils.cmd

Provides the Command class, the base class for the command classes
in the distutils.command package.
"""

# created 2000/04/03, Greg Ward
# (extricated from core.py; actually dates back to the beginning)

__revision__ = "$Id$"

import sys, os, string, re
from types import *
from distutils.errors import *
from distutils import util


class Command:
    """Abstract base class for defining command classes, the "worker bees"
    of the Distutils.  A useful analogy for command classes is to think of
    them as subroutines with local variables called "options".  The options
    are "declared" in 'initialize_options()' and "defined" (given their
    final values, aka "finalized") in 'finalize_options()', both of which
    must be defined by every command class.  The distinction between the
    two is necessary because option values might come from the outside
    world (command line, config file, ...), and any options dependent on
    other options must be computed *after* these outside influences have
    been processed -- hence 'finalize_options()'.  The "body" of the
    subroutine, where it does all its work based on the values of its
    options, is the 'run()' method, which must also be implemented by every
    command class.
    """

    # -- Creation/initialization methods -------------------------------

    def __init__ (self, dist):
        """Create and initialize a new Command object.  Most importantly,
        invokes the 'initialize_options()' method, which is the real
        initializer and depends on the actual command being
        instantiated.
        """
        # late import because of mutual dependence between these classes
        from distutils.dist import Distribution

        if not isinstance (dist, Distribution):
            raise TypeError, "dist must be a Distribution instance"
        if self.__class__ is Command:
            raise RuntimeError, "Command is an abstract class"

        self.distribution = dist
        self.initialize_options ()

        # Per-command versions of the global flags, so that the user can
        # customize Distutils' behaviour command-by-command and let some
        # commands fallback on the Distribution's behaviour.  None means
        # "not defined, check self.distribution's copy", while 0 or 1 mean
        # false and true (duh).  Note that this means figuring out the real
        # value of each flag is a touch complicatd -- hence "self.verbose"
        # (etc.) will be handled by __getattr__, below.
        self._verbose = None
        self._dry_run = None

        # Some commands define a 'self.force' option to ignore file
        # timestamps, but methods defined *here* assume that
        # 'self.force' exists for all commands.  So define it here
        # just to be safe.
        self.force = None

        # The 'help' flag is just used for command-line parsing, so
        # none of that complicated bureaucracy is needed.
        self.help = 0

        # 'finalized' records whether or not 'finalize_options()' has been
        # called.  'finalize_options()' itself should not pay attention to
        # this flag: it is the business of 'ensure_finalized()', which
        # always calls 'finalize_options()', to respect/update it.
        self.finalized = 0

    # __init__ ()


    def __getattr__ (self, attr):
        if attr in ('verbose', 'dry_run'):
            myval = getattr (self, "_" + attr)
            if myval is None:
                return getattr (self.distribution, attr)
            else:
                return myval
        else:
            raise AttributeError, attr


    def ensure_finalized (self):
        if not self.finalized:
            self.finalize_options ()
        self.finalized = 1
        

    # Subclasses must define:
    #   initialize_options()
    #     provide default values for all options; may be customized by
    #     setup script, by options from config file(s), or by command-line
    #     options
    #   finalize_options()
    #     decide on the final values for all options; this is called
    #     after all possible intervention from the outside world
    #     (command-line, option file, etc.) has been processed
    #   run()
    #     run the command: do whatever it is we're here to do,
    #     controlled by the command's various option values

    def initialize_options (self):
        """Set default values for all the options that this command
        supports.  Note that these defaults may be overridden by other
        commands, by the setup script, by config files, or by the
        command-line.  Thus, this is not the place to code dependencies
        between options; generally, 'initialize_options()' implementations
        are just a bunch of "self.foo = None" assignments.
           
        This method must be implemented by all command classes.
        """
        raise RuntimeError, \
              "abstract method -- subclass %s must override" % self.__class__
        
    def finalize_options (self):
        """Set final values for all the options that this command supports.
        This is always called as late as possible, ie.  after any option
        assignments from the command-line or from other commands have been
        done.  Thus, this is the place to to code option dependencies: if
        'foo' depends on 'bar', then it is safe to set 'foo' from 'bar' as
        long as 'foo' still has the same value it was assigned in
        'initialize_options()'.

        This method must be implemented by all command classes.
        """
        raise RuntimeError, \
              "abstract method -- subclass %s must override" % self.__class__


    def dump_options (self, header=None, indent=""):
        from distutils.fancy_getopt import longopt_xlate
        if header is None:
            header = "command options for '%s':" % self.get_command_name()
        print indent + header
        indent = indent + "  "
        for (option, _, _) in self.user_options:
            option = string.translate(option, longopt_xlate)
            if option[-1] == "=":
                option = option[:-1]
            value = getattr(self, option)
            print indent + "%s = %s" % (option, value)


    def run (self):
        """A command's raison d'etre: carry out the action it exists to
        perform, controlled by the options initialized in
        'initialize_options()', customized by other commands, the setup
        script, the command-line, and config files, and finalized in
        'finalize_options()'.  All terminal output and filesystem
        interaction should be done by 'run()'.

        This method must be implemented by all command classes.
        """

        raise RuntimeError, \
              "abstract method -- subclass %s must override" % self.__class__

    def announce (self, msg, level=1):
        """If the current verbosity level is of greater than or equal to
        'level' print 'msg' to stdout.
        """
        if self.verbose >= level:
            print msg

    def debug_print (self, msg):
        """Print 'msg' to stdout if the global DEBUG (taken from the
        DISTUTILS_DEBUG environment variable) flag is true.
        """
        from distutils.core import DEBUG
        if DEBUG:
            print msg
        


    # -- Option validation methods -------------------------------------
    # (these are very handy in writing the 'finalize_options()' method)
    # 
    # NB. the general philosophy here is to ensure that a particular option
    # value meets certain type and value constraints.  If not, we try to
    # force it into conformance (eg. if we expect a list but have a string,
    # split the string on comma and/or whitespace).  If we can't force the
    # option into conformance, raise DistutilsOptionError.  Thus, command
    # classes need do nothing more than (eg.)
    #   self.ensure_string_list('foo')
    # and they can be guaranteed that thereafter, self.foo will be
    # a list of strings.

    def _ensure_stringlike (self, option, what, default=None):
        val = getattr(self, option)
        if val is None:
            setattr(self, option, default)
            return default
        elif type(val) is not StringType:
            raise DistutilsOptionError, \
                  "'%s' must be a %s (got `%s`)" % (option, what, val)
        return val

    def ensure_string (self, option, default=None):
        """Ensure that 'option' is a string; if not defined, set it to
        'default'.
        """
        self._ensure_stringlike(option, "string", default)

    def ensure_string_list (self, option):
        """Ensure that 'option' is a list of strings.  If 'option' is
        currently a string, we split it either on /,\s*/ or /\s+/, so
        "foo bar baz", "foo,bar,baz", and "foo,   bar baz" all become
        ["foo", "bar", "baz"].
        """
        val = getattr(self, option)
        if val is None:
            return
        elif type(val) is StringType:
            setattr(self, option, re.split(r',\s*|\s+', val))
        else:
            if type(val) is ListType:
                types = map(type, val)
                ok = (types == [StringType] * len(val))
            else:
                ok = 0

            if not ok:
                raise DistutilsOptionError, \
                      "'%s' must be a list of strings (got %s)" % \
                      (option, `val`)
        
    def _ensure_tested_string (self, option, tester,
                               what, error_fmt, default=None):
        val = self._ensure_stringlike(option, what, default)
        if val is not None and not tester(val):
            raise DistutilsOptionError, \
                  ("error in '%s' option: " + error_fmt) % (option, val)

    def ensure_filename (self, option):
        """Ensure that 'option' is the name of an existing file."""
        self._ensure_tested_string(option, os.path.isfile,
                                   "filename",
                                   "'%s' does not exist or is not a file")

    def ensure_dirname (self, option):
        self._ensure_tested_string(option, os.path.isdir,
                                   "directory name",
                                   "'%s' does not exist or is not a directory")


    # -- Convenience methods for commands ------------------------------

    def get_command_name (self):
        if hasattr (self, 'command_name'):
            return self.command_name
        else:
            return self.__class__.__name__


    def set_undefined_options (self, src_cmd, *option_pairs):
        """Set the values of any "undefined" options from corresponding
        option values in some other command object.  "Undefined" here means
        "is None", which is the convention used to indicate that an option
        has not been changed between 'initialize_options()' and
        'finalize_options()'.  Usually called from 'finalize_options()' for
        options that depend on some other command rather than another
        option of the same command.  'src_cmd' is the other command from
        which option values will be taken (a command object will be created
        for it if necessary); the remaining arguments are
        '(src_option,dst_option)' tuples which mean "take the value of
        'src_option' in the 'src_cmd' command object, and copy it to
        'dst_option' in the current command object".
        """

        # Option_pairs: list of (src_option, dst_option) tuples

        src_cmd_obj = self.distribution.get_command_obj (src_cmd)
        src_cmd_obj.ensure_finalized ()
        for (src_option, dst_option) in option_pairs:
            if getattr (self, dst_option) is None:
                setattr (self, dst_option,
                         getattr (src_cmd_obj, src_option))


    def get_finalized_command (self, command, create=1):
        """Wrapper around Distribution's 'get_command_obj()' method: find
        (create if necessary and 'create' is true) the command object for
        'command', call its 'ensure_finalized()' method, and return the
        finalized command object.
        """
        cmd_obj = self.distribution.get_command_obj (command, create)
        cmd_obj.ensure_finalized ()
        return cmd_obj

    # XXX rename to 'get_reinitialized_command()'? (should do the
    # same in dist.py, if so)
    def reinitialize_command (self, command):
        return self.distribution.reinitialize_command(command)

    def run_command (self, command):
        """Run some other command: uses the 'run_command()' method of
        Distribution, which creates and finalizes the command object if
        necessary and then invokes its 'run()' method.
        """
        self.distribution.run_command (command)


    # -- External world manipulation -----------------------------------

    def warn (self, msg):
        sys.stderr.write ("warning: %s: %s\n" %
                          (self.get_command_name(), msg))


    def execute (self, func, args, msg=None, level=1):
        """Perform some action that affects the outside world (eg.  by
        writing to the filesystem).  Such actions are special because they
        should be disabled by the "dry run" flag, and should announce
        themselves if the current verbosity level is high enough.  This
        method takes care of all that bureaucracy for you; all you have to
        do is supply the function to call and an argument tuple for it (to
        embody the "external action" being performed), a message to print
        if the verbosity level is high enough, and an optional verbosity
        threshold.
        """

        # Generate a message if we weren't passed one
        if msg is None:
            msg = "%s %s" % (func.__name__, `args`)
            if msg[-2:] == ',)':        # correct for singleton tuple 
                msg = msg[0:-2] + ')'

        # Print it if verbosity level is high enough
        self.announce (msg, level)

        # And do it, as long as we're not in dry-run mode
        if not self.dry_run:
            apply (func, args)

    # execute()


    def mkpath (self, name, mode=0777):
        util.mkpath (name, mode,
                     self.verbose, self.dry_run)


    def copy_file (self, infile, outfile,
                   preserve_mode=1, preserve_times=1, link=None, level=1):
        """Copy a file respecting verbose, dry-run and force flags.  (The
        former two default to whatever is in the Distribution object, and
        the latter defaults to false for commands that don't define it.)"""

        return util.copy_file (infile, outfile,
                               preserve_mode, preserve_times,
                               not self.force,
                               link,
                               self.verbose >= level,
                               self.dry_run)


    def copy_tree (self, infile, outfile,
                   preserve_mode=1, preserve_times=1, preserve_symlinks=0,
                   level=1):
        """Copy an entire directory tree respecting verbose, dry-run,
        and force flags.
        """
        return util.copy_tree (infile, outfile, 
                               preserve_mode,preserve_times,preserve_symlinks,
                               not self.force,
                               self.verbose >= level,
                               self.dry_run)


    def move_file (self, src, dst, level=1):
        """Move a file respecting verbose and dry-run flags."""
        return util.move_file (src, dst,
                               self.verbose >= level,
                               self.dry_run)


    def spawn (self, cmd, search_path=1, level=1):
        """Spawn an external command respecting verbose and dry-run flags."""
        from distutils.spawn import spawn
        spawn (cmd, search_path,
               self.verbose >= level,
               self.dry_run)


    def make_archive (self, base_name, format,
                      root_dir=None, base_dir=None):
        return util.make_archive (base_name, format, root_dir, base_dir,
                                  self.verbose, self.dry_run)


    def make_file (self, infiles, outfile, func, args,
                   exec_msg=None, skip_msg=None, level=1):
        """Special case of 'execute()' for operations that process one or
        more input files and generate one output file.  Works just like
        'execute()', except the operation is skipped and a different
        message printed if 'outfile' already exists and is newer than all
        files listed in 'infiles'.  If the command defined 'self.force',
        and it is true, then the command is unconditionally run -- does no
        timestamp checks.
        """
        if exec_msg is None:
            exec_msg = "generating %s from %s" % \
                       (outfile, string.join (infiles, ', '))
        if skip_msg is None:
            skip_msg = "skipping %s (inputs unchanged)" % outfile
        

        # Allow 'infiles' to be a single string
        if type (infiles) is StringType:
            infiles = (infiles,)
        elif type (infiles) not in (ListType, TupleType):
            raise TypeError, \
                  "'infiles' must be a string, or a list or tuple of strings"

        # If 'outfile' must be regenerated (either because it doesn't
        # exist, is out-of-date, or the 'force' flag is true) then
        # perform the action that presumably regenerates it
        if self.force or util.newer_group (infiles, outfile):
            self.execute (func, args, exec_msg, level)

        # Otherwise, print the "skip" message
        else:
            self.announce (skip_msg, level)

    # make_file ()

# class Command


# XXX 'install_misc' class not currently used -- it was the base class for
# both 'install_scripts' and 'install_data', but they outgrew it.  It might
# still be useful for 'install_headers', though, so I'm keeping it around
# for the time being.

class install_misc (Command):
    """Common base class for installing some files in a subdirectory.
    Currently used by install_data and install_scripts.
    """
    
    user_options = [('install-dir=', 'd', "directory to install the files to")]

    def initialize_options (self):
        self.install_dir = None
        self.outfiles = []

    def _install_dir_from (self, dirname):
        self.set_undefined_options('install', (dirname, 'install_dir'))

    def _copy_files (self, filelist):
        self.outfiles = []
        if not filelist:
            return
        self.mkpath(self.install_dir)
        for f in filelist:
            self.copy_file(f, self.install_dir)
            self.outfiles.append(os.path.join(self.install_dir, f))

    def get_outputs (self):
        return self.outfiles


if __name__ == "__main__":
    print "ok"