mirror of
https://github.com/jart/cosmopolitan.git
synced 2025-02-07 15:03:34 +00:00
60eb34509b
- enable WITH_THREAD and _POSIX_THREADS - add headers everywhere - breaks only two tests (faulthandler and signal) - disabled terminal completion because it causes segfaults for some reason (probably could not get the current thread)
1096 lines
37 KiB
Python
1096 lines
37 KiB
Python
"""Core implementation of import.
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This module is NOT meant to be directly imported! It has been designed such
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that it can be bootstrapped into Python as the implementation of import. As
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such it requires the injection of specific modules and attributes in order to
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work. One should use importlib as the public-facing version of this module.
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"""
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#
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# IMPORTANT: Whenever making changes to this module, be sure to run
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# a top-level make in order to get the frozen version of the module
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# updated. Not doing so will result in the Makefile to fail for
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# all others who don't have a ./python around to freeze the module
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# in the early stages of compilation.
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#
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# See importlib._setup() for what is injected into the global namespace.
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# When editing this code be aware that code executed at import time CANNOT
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# reference any injected objects! This includes not only global code but also
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# anything specified at the class level.
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# Bootstrap-related code ######################################################
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_bootstrap_external = None
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def _wrap(new, old):
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"""Simple substitute for functools.update_wrapper."""
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for replace in ['__module__', '__name__', '__qualname__', '__doc__']:
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if hasattr(old, replace):
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setattr(new, replace, getattr(old, replace))
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new.__dict__.update(old.__dict__)
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# Module-level locking ########################################################
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# A dict mapping module names to weakrefs of _ModuleLock instances
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# Dictionary protected by the global import lock
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_module_locks = {}
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# A dict mapping thread ids to _ModuleLock instances
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_blocking_on = {}
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class _DeadlockError(RuntimeError):
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pass
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class _ModuleLock:
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"""A recursive lock implementation which is able to detect deadlocks
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(e.g. thread 1 trying to take locks A then B, and thread 2 trying to
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take locks B then A).
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"""
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def __init__(self, name):
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self.lock = _thread.allocate_lock()
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self.wakeup = _thread.allocate_lock()
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self.name = name
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self.owner = None
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self.count = 0
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self.waiters = 0
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def has_deadlock(self):
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# Deadlock avoidance for concurrent circular imports.
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me = _thread.get_ident()
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tid = self.owner
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while True:
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lock = _blocking_on.get(tid)
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if lock is None:
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return False
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tid = lock.owner
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if tid == me:
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return True
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def acquire(self):
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"""
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Acquire the module lock. If a potential deadlock is detected,
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a _DeadlockError is raised.
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Otherwise, the lock is always acquired and True is returned.
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"""
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tid = _thread.get_ident()
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_blocking_on[tid] = self
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try:
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while True:
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with self.lock:
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if self.count == 0 or self.owner == tid:
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self.owner = tid
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self.count += 1
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return True
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if self.has_deadlock():
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raise _DeadlockError('deadlock detected by %r' % self)
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if self.wakeup.acquire(False):
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self.waiters += 1
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# Wait for a release() call
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self.wakeup.acquire()
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self.wakeup.release()
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finally:
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del _blocking_on[tid]
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def release(self):
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tid = _thread.get_ident()
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with self.lock:
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if self.owner != tid:
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raise RuntimeError('cannot release un-acquired lock')
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assert self.count > 0
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self.count -= 1
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if self.count == 0:
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self.owner = None
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if self.waiters:
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self.waiters -= 1
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self.wakeup.release()
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def __repr__(self):
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return '_ModuleLock({!r}) at {}'.format(self.name, id(self))
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class _DummyModuleLock:
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"""A simple _ModuleLock equivalent for Python builds without
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multi-threading support."""
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def __init__(self, name):
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self.name = name
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self.count = 0
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def acquire(self):
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self.count += 1
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return True
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def release(self):
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if self.count == 0:
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raise RuntimeError('cannot release un-acquired lock')
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self.count -= 1
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def __repr__(self):
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return '_DummyModuleLock({!r}) at {}'.format(self.name, id(self))
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class _ModuleLockManager:
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def __init__(self, name):
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self._name = name
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self._lock = None
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def __enter__(self):
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self._lock = _get_module_lock(self._name)
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self._lock.acquire()
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def __exit__(self, *args, **kwargs):
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self._lock.release()
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# The following two functions are for consumption by Python/import.c.
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def _get_module_lock(name):
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"""Get or create the module lock for a given module name.
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Acquire/release internally the global import lock to protect
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_module_locks."""
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_imp.acquire_lock()
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try:
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try:
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lock = _module_locks[name]()
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except KeyError:
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lock = None
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if lock is None:
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if _thread is None:
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lock = _DummyModuleLock(name)
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else:
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lock = _ModuleLock(name)
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def cb(ref, name=name):
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_imp.acquire_lock()
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try:
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# bpo-31070: Check if another thread created a new lock
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# after the previous lock was destroyed
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# but before the weakref callback was called.
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if _module_locks.get(name) is ref:
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del _module_locks[name]
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finally:
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_imp.release_lock()
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_module_locks[name] = _weakref.ref(lock, cb)
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finally:
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_imp.release_lock()
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return lock
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def _lock_unlock_module(name):
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"""Acquires then releases the module lock for a given module name.
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This is used to ensure a module is completely initialized, in the
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event it is being imported by another thread.
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"""
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lock = _get_module_lock(name)
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try:
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lock.acquire()
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except _DeadlockError:
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# Concurrent circular import, we'll accept a partially initialized
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# module object.
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pass
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else:
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lock.release()
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# Frame stripping magic ###############################################
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def _call_with_frames_removed(f, *args, **kwds):
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"""remove_importlib_frames in import.c will always remove sequences
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of importlib frames that end with a call to this function
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Use it instead of a normal call in places where including the importlib
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frames introduces unwanted noise into the traceback (e.g. when executing
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module code)
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"""
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return f(*args, **kwds)
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def _verbose_message(message, *args, verbosity=1):
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"""Print the message to stderr if -v/PYTHONVERBOSE is turned on."""
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if sys.flags.verbose >= verbosity:
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if not message.startswith(('#', 'import ')):
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message = '# ' + message
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print(message.format(*args), file=sys.stderr)
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def _requires_builtin(fxn):
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"""Decorator to verify the named module is built-in."""
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def _requires_builtin_wrapper(self, fullname):
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if not _imp.is_builtin(fullname):
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raise ImportError('{!r} is not a built-in module'.format(fullname),
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name=fullname)
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return fxn(self, fullname)
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_wrap(_requires_builtin_wrapper, fxn)
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return _requires_builtin_wrapper
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def _requires_frozen(fxn):
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"""Decorator to verify the named module is frozen."""
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def _requires_frozen_wrapper(self, fullname):
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if not _imp.is_frozen(fullname):
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raise ImportError('{!r} is not a frozen module'.format(fullname),
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name=fullname)
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return fxn(self, fullname)
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_wrap(_requires_frozen_wrapper, fxn)
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return _requires_frozen_wrapper
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# Typically used by loader classes as a method replacement.
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def _load_module_shim(self, fullname):
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"""Load the specified module into sys.modules and return it.
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This method is deprecated. Use loader.exec_module instead.
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"""
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spec = spec_from_loader(fullname, self)
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if fullname in sys.modules:
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module = sys.modules[fullname]
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_exec(spec, module)
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return sys.modules[fullname]
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else:
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return _load(spec)
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# Module specifications #######################################################
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def _module_repr(module):
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# The implementation of ModuleType.__repr__().
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loader = getattr(module, '__loader__', None)
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if hasattr(loader, 'module_repr'):
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# As soon as BuiltinImporter, FrozenImporter, and NamespaceLoader
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# drop their implementations for module_repr. we can add a
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# deprecation warning here.
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try:
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return loader.module_repr(module)
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except Exception:
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pass
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spec = getattr(module, "__spec__", None)
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if spec is not None:
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return _module_repr_from_spec(spec)
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# We could use module.__class__.__name__ instead of 'module' in the
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# various repr permutations.
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name = getattr(module,"__name__", '?')
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filename = getattr(module, "__file__", None)
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if filename is not None:
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return '<module {!r} from {!r}>'.format(name, filename)
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else:
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if loader is None:
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return '<module {!r}>'.format(name)
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else:
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return '<module {!r} ({!r})>'.format(name, loader)
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class _installed_safely:
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def __init__(self, module):
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self._module = module
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self._spec = module.__spec__
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def __enter__(self):
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# This must be done before putting the module in sys.modules
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# (otherwise an optimization shortcut in import.c becomes
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# wrong)
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sys.modules[self._spec.name] = self._module
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def __exit__(self, *args):
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spec = self._spec
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if args and any(arg is not None for arg in args):
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sys.modules.pop(spec.name, None)
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else:
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_verbose_message('import {!r} # {!r}', spec.name, spec.loader)
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class ModuleSpec:
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"""The specification for a module, used for loading.
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A module's spec is the source for information about the module. For
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data associated with the module, including source, use the spec's
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loader.
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`name` is the absolute name of the module. `loader` is the loader
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to use when loading the module. `parent` is the name of the
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package the module is in. The parent is derived from the name.
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`is_package` determines if the module is considered a package or
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not. On modules this is reflected by the `__path__` attribute.
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`origin` is the specific location used by the loader from which to
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load the module, if that information is available. When filename is
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set, origin will match.
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`has_location` indicates that a spec's "origin" reflects a location.
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When this is True, `__file__` attribute of the module is set.
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`cached` is the location of the cached bytecode file, if any. It
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corresponds to the `__cached__` attribute.
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`submodule_search_locations` is the sequence of path entries to
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search when importing submodules. If set, is_package should be
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True--and False otherwise.
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Packages are simply modules that (may) have submodules. If a spec
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has a non-None value in `submodule_search_locations`, the import
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system will consider modules loaded from the spec as packages.
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Only finders (see importlib.abc.MetaPathFinder and
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importlib.abc.PathEntryFinder) should modify ModuleSpec instances.
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"""
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def __init__(self, name, loader, *, origin=None, loader_state=None,
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is_package=None):
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self.name = name
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self.loader = loader
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self.origin = origin
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self.loader_state = loader_state
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self.submodule_search_locations = [] if is_package else None
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# file-location attributes
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self._set_fileattr = False
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self._cached = None
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def __repr__(self):
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args = ['name={!r}'.format(self.name),
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'loader={!r}'.format(self.loader)]
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if self.origin is not None:
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args.append('origin={!r}'.format(self.origin))
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if self.submodule_search_locations is not None:
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args.append('submodule_search_locations={}'
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.format(self.submodule_search_locations))
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return '{}({})'.format(self.__class__.__name__, ', '.join(args))
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def __eq__(self, other):
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smsl = self.submodule_search_locations
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try:
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return (self.name == other.name and
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self.loader == other.loader and
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self.origin == other.origin and
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smsl == other.submodule_search_locations and
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self.cached == other.cached and
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self.has_location == other.has_location)
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except AttributeError:
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return False
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@property
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def cached(self):
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if self._cached is None:
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if self.origin is not None and self._set_fileattr:
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if _bootstrap_external is None:
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raise NotImplementedError
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self._cached = _bootstrap_external._get_cached(self.origin)
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return self._cached
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@cached.setter
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def cached(self, cached):
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self._cached = cached
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@property
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def parent(self):
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"""The name of the module's parent."""
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if self.submodule_search_locations is None:
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return self.name.rpartition('.')[0]
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else:
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return self.name
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@property
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def has_location(self):
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return self._set_fileattr
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@has_location.setter
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def has_location(self, value):
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self._set_fileattr = bool(value)
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def spec_from_loader(name, loader, *, origin=None, is_package=None):
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"""Return a module spec based on various loader methods."""
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if hasattr(loader, 'get_filename'):
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if _bootstrap_external is None:
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raise NotImplementedError
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spec_from_file_location = _bootstrap_external.spec_from_file_location
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if is_package is None:
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return spec_from_file_location(name, loader=loader)
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search = [] if is_package else None
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return spec_from_file_location(name, loader=loader,
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submodule_search_locations=search)
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if is_package is None:
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if hasattr(loader, 'is_package'):
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try:
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is_package = loader.is_package(name)
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except ImportError:
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is_package = None # aka, undefined
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else:
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# the default
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is_package = False
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return ModuleSpec(name, loader, origin=origin, is_package=is_package)
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def _spec_from_module(module, loader=None, origin=None):
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# This function is meant for use in _setup().
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name = module.__name__
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loader = loader or getattr(module, "__loader__", None)
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location = getattr(module, "__file__", None)
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origin = origin or location or getattr(loader, "_ORIGIN", None)
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cached = getattr(module, "__cached__", None)
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submodule_search_locations = getattr(module, "__path__", None)
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if submodule_search_locations is not None:
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submodule_search_locations = list(submodule_search_locations)
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spec = ModuleSpec(name, loader, origin=origin)
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spec._set_fileattr = location is not None
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spec.cached = cached
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spec.submodule_search_locations = submodule_search_locations
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return spec
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def _init_module_attrs(spec, module, *, override=False):
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if override:
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module.__name__ = spec.name
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module.__loader__ = spec.loader
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module.__package__ = spec.parent
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if spec.submodule_search_locations:
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module.__path__ = spec.submodule_search_locations
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if spec.has_location:
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module.__file__ = None or spec.origin
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module.__cached__ = None or spec.cached
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else:
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module.__name__ = getattr(module, "__name__", None) or spec.name
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module.__loader__ = getattr(module, "__loader__", None) or spec.loader
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module.__package__ = getattr(module, "__package__", None) or spec.parent
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if spec.submodule_search_locations and getattr(module, "__path__", None) is None:
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module.__path__ = spec.submodule_search_locations
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if spec.has_location:
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module.__file__ = getattr(module, "__file__", None) or spec.origin
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module.__cached__ = getattr(module, "__cached__", None) or spec.cached
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module.__spec__ = getattr(module, "__spec__", None) or spec
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if module.__loader__ is None:
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# A backward compatibility hack.
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if spec.submodule_search_locations is not None:
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if _bootstrap_external is None:
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raise NotImplementedError
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_NamespaceLoader = _bootstrap_external._NamespaceLoader
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module.__loader__ = _NamespaceLoader.__new__(_NamespaceLoader)
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module.__loader__._path = spec.submodule_search_locations
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return module
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def module_from_spec(spec):
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"""Create a module based on the provided spec."""
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# Typically loaders will not implement create_module().
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module = None
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if hasattr(spec.loader, 'create_module'):
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# If create_module() returns `None` then it means default
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# module creation should be used.
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module = spec.loader.create_module(spec)
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elif hasattr(spec.loader, 'exec_module'):
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raise ImportError('loaders that define exec_module() '
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'must also define create_module()')
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if module is None:
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module = type(sys)(spec.name)
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_init_module_attrs(spec, module)
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return module
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def _module_repr_from_spec(spec):
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"""Return the repr to use for the module."""
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# We mostly replicate _module_repr() using the spec attributes.
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name = '?' if spec.name is None else spec.name
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if spec.origin is None:
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if spec.loader is None:
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return '<module {!r}>'.format(name)
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else:
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return '<module {!r} ({!r})>'.format(name, spec.loader)
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else:
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if spec.has_location:
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return '<module {!r} from {!r}>'.format(name, spec.origin)
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else:
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return '<module {!r} ({})>'.format(spec.name, spec.origin)
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|
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def _exec(spec, module):
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"""Execute the spec's specified module in an existing module's namespace."""
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name = spec.name
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with _ModuleLockManager(name):
|
|
if sys.modules.get(name) is not module:
|
|
msg = 'module {!r} not in sys.modules'.format(name)
|
|
raise ImportError(msg, name=name)
|
|
if spec.loader is None:
|
|
if spec.submodule_search_locations is None:
|
|
raise ImportError('missing loader', name=spec.name)
|
|
# namespace package
|
|
_init_module_attrs(spec, module, override=True)
|
|
return module
|
|
_init_module_attrs(spec, module, override=True)
|
|
if not hasattr(spec.loader, 'exec_module'):
|
|
# (issue19713) Once BuiltinImporter and ExtensionFileLoader
|
|
# have exec_module() implemented, we can add a deprecation
|
|
# warning here.
|
|
spec.loader.load_module(name)
|
|
else:
|
|
spec.loader.exec_module(module)
|
|
return sys.modules[name]
|
|
|
|
def _load_backward_compatible(spec):
|
|
# (issue19713) Once BuiltinImporter and ExtensionFileLoader
|
|
# have exec_module() implemented, we can add a deprecation
|
|
# warning here.
|
|
spec.loader.load_module(spec.name)
|
|
# The module must be in sys.modules at this point!
|
|
module = sys.modules[spec.name]
|
|
if getattr(module, '__loader__', None) is None:
|
|
try:
|
|
module.__loader__ = spec.loader
|
|
except AttributeError:
|
|
pass
|
|
if getattr(module, '__package__', None) is None:
|
|
try:
|
|
# Since module.__path__ may not line up with
|
|
# spec.submodule_search_paths, we can't necessarily rely
|
|
# on spec.parent here.
|
|
module.__package__ = module.__name__
|
|
if not hasattr(module, '__path__'):
|
|
module.__package__ = spec.name.rpartition('.')[0]
|
|
except AttributeError:
|
|
pass
|
|
if getattr(module, '__spec__', None) is None:
|
|
try:
|
|
module.__spec__ = spec
|
|
except AttributeError:
|
|
pass
|
|
return module
|
|
|
|
def _load_unlocked(spec):
|
|
# A helper for direct use by the import system.
|
|
if spec.loader is not None:
|
|
# not a namespace package
|
|
if not hasattr(spec.loader, 'exec_module'):
|
|
return _load_backward_compatible(spec)
|
|
|
|
module = module_from_spec(spec)
|
|
with _installed_safely(module):
|
|
if spec.loader is None:
|
|
if spec.submodule_search_locations is None:
|
|
raise ImportError('missing loader', name=spec.name)
|
|
# A namespace package so do nothing.
|
|
else:
|
|
spec.loader.exec_module(module)
|
|
|
|
# We don't ensure that the import-related module attributes get
|
|
# set in the sys.modules replacement case. Such modules are on
|
|
# their own.
|
|
return sys.modules[spec.name]
|
|
|
|
# A method used during testing of _load_unlocked() and by
|
|
# _load_module_shim().
|
|
def _load(spec):
|
|
"""Return a new module object, loaded by the spec's loader.
|
|
|
|
The module is not added to its parent.
|
|
|
|
If a module is already in sys.modules, that existing module gets
|
|
clobbered.
|
|
|
|
"""
|
|
with _ModuleLockManager(spec.name):
|
|
return _load_unlocked(spec)
|
|
|
|
# Loaders #####################################################################
|
|
|
|
class BuiltinImporter:
|
|
|
|
"""Meta path import for built-in modules.
|
|
|
|
All methods are either class or static methods to avoid the need to
|
|
instantiate the class.
|
|
|
|
"""
|
|
|
|
@staticmethod
|
|
def module_repr(module):
|
|
"""Return repr for the module.
|
|
|
|
The method is deprecated. The import machinery does the job itself.
|
|
|
|
"""
|
|
return '<module {!r} (built-in)>'.format(module.__name__)
|
|
|
|
@classmethod
|
|
def find_spec(cls, fullname, path=None, target=None):
|
|
if path is not None:
|
|
return None
|
|
if _imp.is_builtin(fullname):
|
|
return spec_from_loader(fullname, cls, origin='built-in')
|
|
else:
|
|
return None
|
|
|
|
@classmethod
|
|
def find_module(cls, fullname, path=None):
|
|
"""Find the built-in module.
|
|
|
|
If 'path' is ever specified then the search is considered a failure.
|
|
|
|
This method is deprecated. Use find_spec() instead.
|
|
|
|
"""
|
|
spec = cls.find_spec(fullname, path)
|
|
return spec.loader if spec is not None else None
|
|
|
|
@classmethod
|
|
def create_module(self, spec):
|
|
"""Create a built-in module"""
|
|
if not _imp.is_builtin(spec.name):
|
|
raise ImportError('{!r} is not a built-in module'.format(spec.name),
|
|
name=spec.name)
|
|
return _call_with_frames_removed(_imp.create_builtin, spec)
|
|
|
|
@classmethod
|
|
def exec_module(self, module):
|
|
"""Exec a built-in module"""
|
|
_call_with_frames_removed(_imp.exec_builtin, module)
|
|
|
|
@classmethod
|
|
@_requires_builtin
|
|
def get_code(cls, fullname):
|
|
"""Return None as built-in modules do not have code objects."""
|
|
return None
|
|
|
|
@classmethod
|
|
@_requires_builtin
|
|
def get_source(cls, fullname):
|
|
"""Return None as built-in modules do not have source code."""
|
|
return None
|
|
|
|
@classmethod
|
|
@_requires_builtin
|
|
def is_package(cls, fullname):
|
|
"""Return False as built-in modules are never packages."""
|
|
return False
|
|
|
|
load_module = classmethod(_load_module_shim)
|
|
|
|
|
|
class FrozenImporter:
|
|
|
|
"""Meta path import for frozen modules.
|
|
|
|
All methods are either class or static methods to avoid the need to
|
|
instantiate the class.
|
|
|
|
"""
|
|
|
|
@staticmethod
|
|
def module_repr(m):
|
|
"""Return repr for the module.
|
|
|
|
The method is deprecated. The import machinery does the job itself.
|
|
|
|
"""
|
|
return '<module {!r} (frozen)>'.format(m.__name__)
|
|
|
|
@classmethod
|
|
def find_spec(cls, fullname, path=None, target=None):
|
|
if _imp.is_frozen(fullname):
|
|
return spec_from_loader(fullname, cls, origin='frozen')
|
|
else:
|
|
return None
|
|
|
|
@classmethod
|
|
def find_module(cls, fullname, path=None):
|
|
"""Find a frozen module.
|
|
|
|
This method is deprecated. Use find_spec() instead.
|
|
|
|
"""
|
|
return cls if _imp.is_frozen(fullname) else None
|
|
|
|
@classmethod
|
|
def create_module(cls, spec):
|
|
"""Use default semantics for module creation."""
|
|
|
|
@staticmethod
|
|
def exec_module(module):
|
|
name = module.__spec__.name
|
|
if not _imp.is_frozen(name):
|
|
raise ImportError('{!r} is not a frozen module'.format(name),
|
|
name=name)
|
|
code = _call_with_frames_removed(_imp.get_frozen_object, name)
|
|
exec(code, module.__dict__)
|
|
|
|
@classmethod
|
|
def load_module(cls, fullname):
|
|
"""Load a frozen module.
|
|
|
|
This method is deprecated. Use exec_module() instead.
|
|
|
|
"""
|
|
return _load_module_shim(cls, fullname)
|
|
|
|
@classmethod
|
|
@_requires_frozen
|
|
def get_code(cls, fullname):
|
|
"""Return the code object for the frozen module."""
|
|
return _imp.get_frozen_object(fullname)
|
|
|
|
@classmethod
|
|
@_requires_frozen
|
|
def get_source(cls, fullname):
|
|
"""Return None as frozen modules do not have source code."""
|
|
return None
|
|
|
|
@classmethod
|
|
@_requires_frozen
|
|
def is_package(cls, fullname):
|
|
"""Return True if the frozen module is a package."""
|
|
return _imp.is_frozen_package(fullname)
|
|
|
|
|
|
# Import itself ###############################################################
|
|
|
|
class _ImportLockContext:
|
|
|
|
"""Context manager for the import lock."""
|
|
|
|
def __enter__(self):
|
|
"""Acquire the import lock."""
|
|
_imp.acquire_lock()
|
|
|
|
def __exit__(self, exc_type, exc_value, exc_traceback):
|
|
"""Release the import lock regardless of any raised exceptions."""
|
|
_imp.release_lock()
|
|
|
|
|
|
def _resolve_name(name, package, level):
|
|
"""Resolve a relative module name to an absolute one."""
|
|
bits = package.rsplit('.', level - 1)
|
|
if len(bits) < level:
|
|
raise ValueError('attempted relative import beyond top-level package')
|
|
base = bits[0]
|
|
return '{}.{}'.format(base, name) if name else base
|
|
|
|
|
|
def _find_spec_legacy(finder, name, path):
|
|
# This would be a good place for a DeprecationWarning if
|
|
# we ended up going that route.
|
|
loader = finder.find_module(name, path)
|
|
if loader is None:
|
|
return None
|
|
return spec_from_loader(name, loader)
|
|
|
|
|
|
def _find_spec(name, path, target=None):
|
|
"""Find a module's spec."""
|
|
meta_path = sys.meta_path
|
|
if meta_path is None:
|
|
# PyImport_Cleanup() is running or has been called.
|
|
raise ImportError("sys.meta_path is None, Python is likely "
|
|
"shutting down")
|
|
|
|
if not meta_path:
|
|
_warnings.warn('sys.meta_path is empty', ImportWarning)
|
|
|
|
# We check sys.modules here for the reload case. While a passed-in
|
|
# target will usually indicate a reload there is no guarantee, whereas
|
|
# sys.modules provides one.
|
|
is_reload = name in sys.modules
|
|
for finder in meta_path:
|
|
try:
|
|
find_spec = finder.find_spec
|
|
except AttributeError:
|
|
spec = _find_spec_legacy(finder, name, path)
|
|
if spec is None:
|
|
continue
|
|
else:
|
|
spec = find_spec(name, path, target)
|
|
if spec is not None:
|
|
# The parent import may have already imported this module.
|
|
if not is_reload and name in sys.modules:
|
|
module = sys.modules[name]
|
|
try:
|
|
__spec__ = module.__spec__
|
|
except AttributeError:
|
|
# We use the found spec since that is the one that
|
|
# we would have used if the parent module hadn't
|
|
# beaten us to the punch.
|
|
return spec
|
|
else:
|
|
if __spec__ is None:
|
|
return spec
|
|
else:
|
|
return __spec__
|
|
else:
|
|
return spec
|
|
else:
|
|
return None
|
|
|
|
|
|
def _sanity_check(name, package, level):
|
|
"""Verify arguments are "sane"."""
|
|
if not isinstance(name, str):
|
|
raise TypeError('module name must be str, not {}'.format(type(name)))
|
|
if level < 0:
|
|
raise ValueError('level must be >= 0')
|
|
if level > 0:
|
|
if not isinstance(package, str):
|
|
raise TypeError('__package__ not set to a string')
|
|
elif not package:
|
|
raise ImportError('attempted relative import with no known parent '
|
|
'package')
|
|
if not name and level == 0:
|
|
raise ValueError('Empty module name')
|
|
|
|
|
|
_ERR_MSG_PREFIX = 'No module named '
|
|
_ERR_MSG = _ERR_MSG_PREFIX + '{!r}'
|
|
|
|
def _find_and_load_unlocked(name, import_):
|
|
path = None
|
|
parent = name.rpartition('.')[0]
|
|
if parent:
|
|
if parent not in sys.modules:
|
|
_call_with_frames_removed(import_, parent)
|
|
# Crazy side-effects!
|
|
if name in sys.modules:
|
|
return sys.modules[name]
|
|
parent_module = sys.modules[parent]
|
|
try:
|
|
path = parent_module.__path__
|
|
except AttributeError:
|
|
msg = (_ERR_MSG + '; {!r} is not a package').format(name, parent)
|
|
raise ModuleNotFoundError(msg, name=name) from None
|
|
spec = _find_spec(name, path)
|
|
if spec is None and _imp.is_builtin(name):
|
|
# If this module is a C extension, the interpreter
|
|
# expects it to be a shared object located in path,
|
|
# and returns spec is None because it was not found.
|
|
#
|
|
# however, if it is a C extension, we can check if it
|
|
# is available using sys.builtin_module_names,
|
|
# because the APE is statically compiled.
|
|
#
|
|
# if the module is present as a builtin, we call
|
|
# BuiltinImporter with the full name (and no path)
|
|
# to create the module spec correctly.
|
|
spec = BuiltinImporter.find_spec(name)
|
|
if spec is None:
|
|
raise ModuleNotFoundError(_ERR_MSG.format(name), name=name)
|
|
else:
|
|
module = _load_unlocked(spec)
|
|
if parent:
|
|
# Set the module as an attribute on its parent.
|
|
parent_module = sys.modules[parent]
|
|
setattr(parent_module, name.rpartition('.')[2], module)
|
|
return module
|
|
|
|
|
|
_NEEDS_LOADING = object()
|
|
|
|
|
|
def _find_and_load(name, import_):
|
|
"""Find and load the module."""
|
|
module = sys.modules.get(name, _NEEDS_LOADING)
|
|
if module is _NEEDS_LOADING:
|
|
return _find_and_load_unlocked(name, import_)
|
|
|
|
if module is None:
|
|
message = ('import of {} halted; '
|
|
'None in sys.modules'.format(name))
|
|
raise ModuleNotFoundError(message, name=name)
|
|
|
|
return module
|
|
|
|
|
|
def _gcd_import(name, package=None, level=0):
|
|
"""Import and return the module based on its name, the package the call is
|
|
being made from, and the level adjustment.
|
|
|
|
This function represents the greatest common denominator of functionality
|
|
between import_module and __import__. This includes setting __package__ if
|
|
the loader did not.
|
|
|
|
"""
|
|
_sanity_check(name, package, level)
|
|
if level > 0:
|
|
name = _resolve_name(name, package, level)
|
|
return _find_and_load(name, _gcd_import)
|
|
|
|
|
|
def _handle_fromlist(module, fromlist, import_, *, recursive=False):
|
|
"""Figure out what __import__ should return.
|
|
|
|
The import_ parameter is a callable which takes the name of module to
|
|
import. It is required to decouple the function from assuming importlib's
|
|
import implementation is desired.
|
|
|
|
"""
|
|
# The hell that is fromlist ...
|
|
# If a package was imported, try to import stuff from fromlist.
|
|
if hasattr(module, '__path__'):
|
|
for x in fromlist:
|
|
if not isinstance(x, str):
|
|
if recursive:
|
|
where = module.__name__ + '.__all__'
|
|
else:
|
|
where = "``from list''"
|
|
raise TypeError(f"Item in {where} must be str, "
|
|
f"not {type(x).__name__}")
|
|
elif x == '*':
|
|
if not recursive and hasattr(module, '__all__'):
|
|
_handle_fromlist(module, module.__all__, import_,
|
|
recursive=True)
|
|
elif not hasattr(module, x):
|
|
from_name = '{}.{}'.format(module.__name__, x)
|
|
try:
|
|
_call_with_frames_removed(import_, from_name)
|
|
except ModuleNotFoundError as exc:
|
|
# Backwards-compatibility dictates we ignore failed
|
|
# imports triggered by fromlist for modules that don't
|
|
# exist.
|
|
if (exc.name == from_name and
|
|
sys.modules.get(from_name, _NEEDS_LOADING) is not None):
|
|
continue
|
|
raise
|
|
return module
|
|
|
|
|
|
def _calc___package__(globals):
|
|
"""Calculate what __package__ should be.
|
|
|
|
__package__ is not guaranteed to be defined or could be set to None
|
|
to represent that its proper value is unknown.
|
|
|
|
"""
|
|
package = globals.get('__package__')
|
|
spec = globals.get('__spec__')
|
|
if package is not None:
|
|
if spec is not None and package != spec.parent:
|
|
_warnings.warn("__package__ != __spec__.parent "
|
|
f"({package!r} != {spec.parent!r})",
|
|
ImportWarning, stacklevel=3)
|
|
return package
|
|
elif spec is not None:
|
|
return spec.parent
|
|
else:
|
|
_warnings.warn("can't resolve package from __spec__ or __package__, "
|
|
"falling back on __name__ and __path__",
|
|
ImportWarning, stacklevel=3)
|
|
package = globals['__name__']
|
|
if '__path__' not in globals:
|
|
package = package.rpartition('.')[0]
|
|
return package
|
|
|
|
|
|
def __import__(name, globals=None, locals=None, fromlist=(), level=0):
|
|
"""Import a module.
|
|
|
|
The 'globals' argument is used to infer where the import is occurring from
|
|
to handle relative imports. The 'locals' argument is ignored. The
|
|
'fromlist' argument specifies what should exist as attributes on the module
|
|
being imported (e.g. ``from module import <fromlist>``). The 'level'
|
|
argument represents the package location to import from in a relative
|
|
import (e.g. ``from ..pkg import mod`` would have a 'level' of 2).
|
|
|
|
"""
|
|
if level == 0:
|
|
module = _gcd_import(name)
|
|
else:
|
|
globals_ = globals if globals is not None else {}
|
|
package = _calc___package__(globals_)
|
|
module = _gcd_import(name, package, level)
|
|
if not fromlist:
|
|
# Return up to the first dot in 'name'. This is complicated by the fact
|
|
# that 'name' may be relative.
|
|
if level == 0:
|
|
return _gcd_import(name.partition('.')[0])
|
|
elif not name:
|
|
return module
|
|
else:
|
|
# Figure out where to slice the module's name up to the first dot
|
|
# in 'name'.
|
|
cut_off = len(name) - len(name.partition('.')[0])
|
|
# Slice end needs to be positive to alleviate need to special-case
|
|
# when ``'.' not in name``.
|
|
return sys.modules[module.__name__[:len(module.__name__)-cut_off]]
|
|
else:
|
|
return _handle_fromlist(module, fromlist, _gcd_import)
|
|
|
|
|
|
def _builtin_from_name(name):
|
|
spec = BuiltinImporter.find_spec(name)
|
|
if spec is None:
|
|
raise ImportError('no built-in module named ' + name)
|
|
return _load_unlocked(spec)
|
|
|
|
def _get_builtin_spec(name):
|
|
# called from CosmoImporter in import.c
|
|
return ModuleSpec(name, BuiltinImporter, origin="built-in", is_package=False)
|
|
|
|
def _get_frozen_spec(name, is_package):
|
|
# called from CosmoImporter in import.c
|
|
return ModuleSpec(name, FrozenImporter, origin="frozen", is_package=is_package)
|
|
|
|
def _get_zipstore_spec(name, loader, origin, is_package):
|
|
# called from CosmoImporter in import.c
|
|
spec = ModuleSpec(name, loader, origin=origin, is_package=is_package)
|
|
spec.has_location = True
|
|
if is_package:
|
|
spec.submodule_search_locations = [origin.rpartition("/")[0]]
|
|
return spec
|
|
|
|
def _setup(sys_module, _imp_module):
|
|
"""Setup importlib by importing needed built-in modules and injecting them
|
|
into the global namespace.
|
|
|
|
As sys is needed for sys.modules access and _imp is needed to load built-in
|
|
modules, those two modules must be explicitly passed in.
|
|
|
|
"""
|
|
global _imp, sys
|
|
_imp = _imp_module
|
|
sys = sys_module
|
|
|
|
# Set up the spec for existing builtin/frozen modules.
|
|
module_type = type(sys)
|
|
for name, module in sys.modules.items():
|
|
if isinstance(module, module_type):
|
|
if _imp.is_builtin(name):
|
|
loader = BuiltinImporter
|
|
elif _imp.is_frozen(name):
|
|
loader = FrozenImporter
|
|
else:
|
|
continue
|
|
spec = getattr(module, "__spec__", None) or _spec_from_module(module, loader)
|
|
_init_module_attrs(spec, module)
|
|
|
|
# Directly load built-in modules needed during bootstrap.
|
|
self_module = sys.modules[__name__]
|
|
for builtin_name in ('_warnings', '_weakref'):
|
|
builtin_module = sys.modules.get(builtin_name, _builtin_from_name(builtin_name))
|
|
setattr(self_module, builtin_name, builtin_module)
|
|
setattr(self_module, '_thread', None)
|
|
|
|
|
|
def _install(sys_module, _imp_module):
|
|
"""Install importlib as the implementation of import."""
|
|
_setup(sys_module, _imp_module)
|
|
|
|
sys.meta_path.append(_imp_module.CosmoImporter)
|
|
# sys.meta_path.append(BuiltinImporter)
|
|
# sys.meta_path.append(FrozenImporter)
|
|
|
|
global _bootstrap_external
|
|
import _frozen_importlib_external
|
|
_bootstrap_external = _frozen_importlib_external
|
|
_frozen_importlib_external._install(sys.modules[__name__])
|