Source

SCons / src / engine / SCons / Platform / __init__.py

"""SCons.Platform

SCons platform selection.

This looks for modules that define a callable object that can modify a
construction environment as appropriate for a given platform.

Note that we take a more simplistic view of "platform" than Python does.
We're looking for a single string that determines a set of
tool-independent variables with which to initialize a construction
environment.  Consequently, we'll examine both sys.platform and os.name
(and anything else that might come in to play) in order to return some
specification which is unique enough for our purposes.

Note that because this subsysem just *selects* a callable that can
modify a construction environment, it's possible for people to define
their own "platform specification" in an arbitrary callable function.
No one needs to use or tie in to this subsystem in order to roll
their own platform definition.
"""

#
# __COPYRIGHT__
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# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
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# The above copyright notice and this permission notice shall be included
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# KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
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__revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"

import imp
import os
import sys

import SCons.Errors

def platform_default():
    """Return the platform string for our execution environment.

    The returned value should map to one of the SCons/Platform/*.py
    files.  Since we're architecture independent, though, we don't
    care about the machine architecture.
    """
    osname = os.name
    if osname == 'java':
        osname = os._osType
    if osname == 'posix':
        if sys.platform == 'cygwin':
            return 'cygwin'
        return 'posix'
    elif os.name == 'os2':
        return 'os2'
    else:
        return sys.platform

def platform_module(name = platform_default()):
    """Return the imported module for the platform.

    This looks for a module name that matches the specified argument.
    If the name is unspecified, we fetch the appropriate default for
    our execution environment.
    """
    full_name = 'SCons.Platform.' + name
    if not sys.modules.has_key(full_name):
        if os.name == 'java':
            eval(full_name)
        else:
            try:
                file, path, desc = imp.find_module(name,
                                        sys.modules['SCons.Platform'].__path__)
                imp.load_module(full_name, file, path, desc)
            except ImportError:
                raise SCons.Errors.UserError, "No platform named '%s'" % name
            if file:
                file.close()
    return sys.modules[full_name]

def DefaultToolList(platform, env):
    """Select a default tool list for the specified platform.
    """
    return SCons.Tool.tool_list(platform, env)

class PlatformSpec:
    def __init__(self, name):
        self.name = name

    def __str__(self):
        return self.name
    
def Platform(name = platform_default()):
    """Select a canned Platform specification.
    """
    module = platform_module(name)
    spec = PlatformSpec(name)
    spec.__call__ = module.generate
    return spec