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depot_tools/third_party/logilab/astroid/manager.py

268 lines
11 KiB
Python

# copyright 2003-2013 LOGILAB S.A. (Paris, FRANCE), all rights reserved.
# contact http://www.logilab.fr/ -- mailto:contact@logilab.fr
#
# This file is part of astroid.
#
# astroid is free software: you can redistribute it and/or modify it
# under the terms of the GNU Lesser General Public License as published by the
# Free Software Foundation, either version 2.1 of the License, or (at your
# option) any later version.
#
# astroid is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
# FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
# for more details.
#
# You should have received a copy of the GNU Lesser General Public License along
# with astroid. If not, see <http://www.gnu.org/licenses/>.
"""astroid manager: avoid multiple astroid build of a same module when
possible by providing a class responsible to get astroid representation
from various source and using a cache of built modules)
"""
from __future__ import print_function
import imp
import os
import zipimport
from astroid import exceptions
from astroid import modutils
from astroid import transforms
def safe_repr(obj):
try:
return repr(obj)
except Exception: # pylint: disable=broad-except
return '???'
class AstroidManager(object):
"""the astroid manager, responsible to build astroid from files
or modules.
Use the Borg pattern.
"""
name = 'astroid loader'
brain = {}
def __init__(self):
self.__dict__ = AstroidManager.brain
if not self.__dict__:
# NOTE: cache entries are added by the [re]builder
self.astroid_cache = {}
self._mod_file_cache = {}
self._failed_import_hooks = []
self.always_load_extensions = False
self.optimize_ast = False
self.extension_package_whitelist = set()
self._transform = transforms.TransformVisitor()
# Export these APIs for convenience
self.register_transform = self._transform.register_transform
self.unregister_transform = self._transform.unregister_transform
def visit_transforms(self, node):
"""Visit the transforms and apply them to the given *node*."""
return self._transform.visit(node)
def ast_from_file(self, filepath, modname=None, fallback=True, source=False):
"""given a module name, return the astroid object"""
try:
filepath = modutils.get_source_file(filepath, include_no_ext=True)
source = True
except modutils.NoSourceFile:
pass
if modname is None:
try:
modname = '.'.join(modutils.modpath_from_file(filepath))
except ImportError:
modname = filepath
if modname in self.astroid_cache and self.astroid_cache[modname].source_file == filepath:
return self.astroid_cache[modname]
if source:
from astroid.builder import AstroidBuilder
return AstroidBuilder(self).file_build(filepath, modname)
elif fallback and modname:
return self.ast_from_module_name(modname)
raise exceptions.AstroidBuildingException(
'unable to get astroid for file %s' % filepath)
def _build_stub_module(self, modname):
from astroid.builder import AstroidBuilder
return AstroidBuilder(self).string_build('', modname)
def _can_load_extension(self, modname):
if self.always_load_extensions:
return True
if modutils.is_standard_module(modname):
return True
parts = modname.split('.')
return any(
'.'.join(parts[:x]) in self.extension_package_whitelist
for x in range(1, len(parts) + 1))
def ast_from_module_name(self, modname, context_file=None):
"""given a module name, return the astroid object"""
if modname in self.astroid_cache:
return self.astroid_cache[modname]
if modname == '__main__':
return self._build_stub_module(modname)
old_cwd = os.getcwd()
if context_file:
os.chdir(os.path.dirname(context_file))
try:
filepath, mp_type = self.file_from_module_name(modname, context_file)
if mp_type == modutils.PY_ZIPMODULE:
module = self.zip_import_data(filepath)
if module is not None:
return module
elif mp_type in (imp.C_BUILTIN, imp.C_EXTENSION):
if mp_type == imp.C_EXTENSION and not self._can_load_extension(modname):
return self._build_stub_module(modname)
try:
module = modutils.load_module_from_name(modname)
except Exception as ex:
msg = 'Unable to load module %s (%s)' % (modname, ex)
raise exceptions.AstroidBuildingException(msg)
return self.ast_from_module(module, modname)
elif mp_type == imp.PY_COMPILED:
msg = "Unable to load compiled module %s" % (modname,)
raise exceptions.AstroidBuildingException(msg)
if filepath is None:
msg = "Unable to load module %s" % (modname,)
raise exceptions.AstroidBuildingException(msg)
return self.ast_from_file(filepath, modname, fallback=False)
except exceptions.AstroidBuildingException as e:
for hook in self._failed_import_hooks:
try:
return hook(modname)
except exceptions.AstroidBuildingException:
pass
raise e
finally:
os.chdir(old_cwd)
def zip_import_data(self, filepath):
if zipimport is None:
return None
from astroid.builder import AstroidBuilder
builder = AstroidBuilder(self)
for ext in ('.zip', '.egg'):
try:
eggpath, resource = filepath.rsplit(ext + os.path.sep, 1)
except ValueError:
continue
try:
importer = zipimport.zipimporter(eggpath + ext)
zmodname = resource.replace(os.path.sep, '.')
if importer.is_package(resource):
zmodname = zmodname + '.__init__'
module = builder.string_build(importer.get_source(resource),
zmodname, filepath)
return module
except Exception: # pylint: disable=broad-except
continue
return None
def file_from_module_name(self, modname, contextfile):
# pylint: disable=redefined-variable-type
try:
value = self._mod_file_cache[(modname, contextfile)]
except KeyError:
try:
value = modutils.file_info_from_modpath(
modname.split('.'), context_file=contextfile)
except ImportError as ex:
msg = 'Unable to load module %s (%s)' % (modname, ex)
value = exceptions.AstroidBuildingException(msg)
self._mod_file_cache[(modname, contextfile)] = value
if isinstance(value, exceptions.AstroidBuildingException):
raise value
return value
def ast_from_module(self, module, modname=None):
"""given an imported module, return the astroid object"""
modname = modname or module.__name__
if modname in self.astroid_cache:
return self.astroid_cache[modname]
try:
# some builtin modules don't have __file__ attribute
filepath = module.__file__
if modutils.is_python_source(filepath):
return self.ast_from_file(filepath, modname)
except AttributeError:
pass
from astroid.builder import AstroidBuilder
return AstroidBuilder(self).module_build(module, modname)
def ast_from_class(self, klass, modname=None):
"""get astroid for the given class"""
if modname is None:
try:
modname = klass.__module__
except AttributeError:
msg = 'Unable to get module for class %s' % safe_repr(klass)
raise exceptions.AstroidBuildingException(msg)
modastroid = self.ast_from_module_name(modname)
return modastroid.getattr(klass.__name__)[0] # XXX
def infer_ast_from_something(self, obj, context=None):
"""infer astroid for the given class"""
if hasattr(obj, '__class__') and not isinstance(obj, type):
klass = obj.__class__
else:
klass = obj
try:
modname = klass.__module__
except AttributeError:
msg = 'Unable to get module for %s' % safe_repr(klass)
raise exceptions.AstroidBuildingException(msg)
except Exception as ex:
msg = ('Unexpected error while retrieving module for %s: %s'
% (safe_repr(klass), ex))
raise exceptions.AstroidBuildingException(msg)
try:
name = klass.__name__
except AttributeError:
msg = 'Unable to get name for %s' % safe_repr(klass)
raise exceptions.AstroidBuildingException(msg)
except Exception as ex:
exc = ('Unexpected error while retrieving name for %s: %s'
% (safe_repr(klass), ex))
raise exceptions.AstroidBuildingException(exc)
# take care, on living object __module__ is regularly wrong :(
modastroid = self.ast_from_module_name(modname)
if klass is obj:
for inferred in modastroid.igetattr(name, context):
yield inferred
else:
for inferred in modastroid.igetattr(name, context):
yield inferred.instantiate_class()
def register_failed_import_hook(self, hook):
"""Registers a hook to resolve imports that cannot be found otherwise.
`hook` must be a function that accepts a single argument `modname` which
contains the name of the module or package that could not be imported.
If `hook` can resolve the import, must return a node of type `astroid.Module`,
otherwise, it must raise `AstroidBuildingException`.
"""
self._failed_import_hooks.append(hook)
def cache_module(self, module):
"""Cache a module if no module with the same name is known yet."""
self.astroid_cache.setdefault(module.name, module)
def clear_cache(self, astroid_builtin=None):
# XXX clear transforms
self.astroid_cache.clear()
# force bootstrap again, else we may ends up with cache inconsistency
# between the manager and CONST_PROXY, making
# unittest_lookup.LookupTC.test_builtin_lookup fail depending on the
# test order
import astroid.raw_building
astroid.raw_building._astroid_bootstrapping(
astroid_builtin=astroid_builtin)