pylint: upgrade to 1.3.1

third_party/logilab/astroid/brain/py2stdlib.py

+"""Astroid hooks for the Python 2 standard library.
+
+Currently help understanding of :
+
+* hashlib.md5 and hashlib.sha1
+"""
+
+import sys
+from textwrap import dedent
+
+from astroid import (
+    MANAGER, AsStringRegexpPredicate,
+    UseInferenceDefault, inference_tip,
+    YES, InferenceError)
+from astroid import exceptions
+from astroid import nodes
+from astroid.builder import AstroidBuilder
+
+MODULE_TRANSFORMS = {}
+PY3K = sys.version_info > (3, 0)
+PY33 = sys.version_info >= (3, 3)
+
+# general function
+
+def infer_func_form(node, base_type, context=None, enum=False):
+    """Specific inference function for namedtuple or Python 3 enum. """
+    def infer_first(node):
+        try:
+            value = node.infer(context=context).next()
+            if value is YES:
+                raise UseInferenceDefault()
+            else:
+                return value
+        except StopIteration:
+            raise InferenceError()
+
+    # node is a CallFunc node, class name as first argument and generated class
+    # attributes as second argument
+    if len(node.args) != 2:
+        # something weird here, go back to class implementation
+        raise UseInferenceDefault()
+    # namedtuple or enums list of attributes can be a list of strings or a
+    # whitespace-separate string
+    try:
+        name = infer_first(node.args[0]).value
+        names = infer_first(node.args[1])
+        try:
+            attributes = names.value.replace(',', ' ').split()
+        except AttributeError:
+            if not enum:
+                attributes = [infer_first(const).value for const in names.elts]
+            else:
+                # Enums supports either iterator of (name, value) pairs
+                # or mappings.
+                # TODO: support only list, tuples and mappings.
+                if hasattr(names, 'items') and isinstance(names.items, list):
+                    attributes = [infer_first(const[0]).value
+                                  for const in names.items
+                                  if isinstance(const[0], nodes.Const)]
+                elif hasattr(names, 'elts'):
+                    # Enums can support either ["a", "b", "c"]
+                    # or [("a", 1), ("b", 2), ...], but they can't
+                    # be mixed.
+                    if all(isinstance(const, nodes.Tuple)
+                           for const in names.elts):
+                        attributes = [infer_first(const.elts[0]).value
+                                      for const in names.elts
+                                      if isinstance(const, nodes.Tuple)]
+                    else:
+                        attributes = [infer_first(const).value
+                                      for const in names.elts]
+                else:
+                    raise AttributeError
+                if not attributes:
+                    raise AttributeError
+    except (AttributeError, exceptions.InferenceError) as exc:
+        raise UseInferenceDefault()
+    # we want to return a Class node instance with proper attributes set
+    class_node = nodes.Class(name, 'docstring')
+    class_node.parent = node.parent
+    # set base class=tuple
+    class_node.bases.append(base_type)
+    # XXX add __init__(*attributes) method
+    for attr in attributes:
+        fake_node = nodes.EmptyNode()
+        fake_node.parent = class_node
+        class_node.instance_attrs[attr] = [fake_node]
+    return class_node, name, attributes
+
+
+# module specific transformation functions #####################################
+
+def transform(module):
+    try:
+        tr = MODULE_TRANSFORMS[module.name]
+    except KeyError:
+        pass
+    else:
+        tr(module)
+MANAGER.register_transform(nodes.Module, transform)
+
+# module specific transformation functions #####################################
+
+def hashlib_transform(module):
+    template = '''
+
+class %s(object):
+  def __init__(self, value=''): pass
+  def digest(self):
+    return u''
+  def update(self, value): pass
+  def hexdigest(self):
+    return u''
+'''
+
+    algorithms = ('md5', 'sha1', 'sha224', 'sha256', 'sha384', 'sha512')
+    classes = "".join(template % hashfunc for hashfunc in algorithms)
+
+    fake = AstroidBuilder(MANAGER).string_build(classes)
+
+    for hashfunc in algorithms:
+        module.locals[hashfunc] = fake.locals[hashfunc]
+
+def collections_transform(module):
+    fake = AstroidBuilder(MANAGER).string_build('''
+
+class defaultdict(dict):
+    default_factory = None
+    def __missing__(self, key): pass
+
+class deque(object):
+    maxlen = 0
+    def __init__(self, iterable=None, maxlen=None): pass
+    def append(self, x): pass
+    def appendleft(self, x): pass
+    def clear(self): pass
+    def count(self, x): return 0
+    def extend(self, iterable): pass
+    def extendleft(self, iterable): pass
+    def pop(self): pass
+    def popleft(self): pass
+    def remove(self, value): pass
+    def reverse(self): pass
+    def rotate(self, n): pass
+    def __iter__(self): return self
+
+''')
+
+    for klass in ('deque', 'defaultdict'):
+        module.locals[klass] = fake.locals[klass]
+
+def pkg_resources_transform(module):
+    fake = AstroidBuilder(MANAGER).string_build('''
+
+def resource_exists(package_or_requirement, resource_name):
+    pass
+
+def resource_isdir(package_or_requirement, resource_name):
+    pass
+
+def resource_filename(package_or_requirement, resource_name):
+    pass
+
+def resource_stream(package_or_requirement, resource_name):
+    pass
+
+def resource_string(package_or_requirement, resource_name):
+    pass
+
+def resource_listdir(package_or_requirement, resource_name):
+    pass
+
+def extraction_error():
+    pass
+
+def get_cache_path(archive_name, names=()):
+    pass
+
+def postprocess(tempname, filename):
+    pass
+
+def set_extraction_path(path):
+    pass
+
+def cleanup_resources(force=False):
+    pass
+
+''')
+
+    for func_name, func in fake.locals.items():
+        module.locals[func_name] = func
+
+
+def subprocess_transform(module):
+    if PY3K:
+        communicate = (bytes('string', 'ascii'), bytes('string', 'ascii'))
+        init = """
+    def __init__(self, args, bufsize=0, executable=None,
+                 stdin=None, stdout=None, stderr=None,
+                 preexec_fn=None, close_fds=False, shell=False,
+                 cwd=None, env=None, universal_newlines=False,
+                 startupinfo=None, creationflags=0, restore_signals=True,
+                 start_new_session=False, pass_fds=()):
+        pass
+        """
+    else:
+        communicate = ('string', 'string')
+        init = """
+    def __init__(self, args, bufsize=0, executable=None,
+                 stdin=None, stdout=None, stderr=None,
+                 preexec_fn=None, close_fds=False, shell=False,
+                 cwd=None, env=None, universal_newlines=False,
+                 startupinfo=None, creationflags=0):
+        pass
+        """
+    if PY33:
+        wait_signature = 'def wait(self, timeout=None)'
+    else:
+        wait_signature = 'def wait(self)'
+    fake = AstroidBuilder(MANAGER).string_build('''
+
+class Popen(object):
+    returncode = pid = 0
+    stdin = stdout = stderr = file()
+
+    %(init)s
+
+    def communicate(self, input=None):
+        return %(communicate)r
+    %(wait_signature)s:
+        return self.returncode
+    def poll(self):
+        return self.returncode
+    def send_signal(self, signal):
+        pass
+    def terminate(self):
+        pass
+    def kill(self):
+        pass
+   ''' % {'init': init,
+          'communicate': communicate,
+          'wait_signature': wait_signature})
+
+    for func_name, func in fake.locals.items():
+        module.locals[func_name] = func
+
+
+
+MODULE_TRANSFORMS['hashlib'] = hashlib_transform
+MODULE_TRANSFORMS['collections'] = collections_transform
+MODULE_TRANSFORMS['pkg_resources'] = pkg_resources_transform
+MODULE_TRANSFORMS['subprocess'] = subprocess_transform
+
+# namedtuple support ###########################################################
+
+def infer_named_tuple(node, context=None):
+    """Specific inference function for namedtuple CallFunc node"""
+    class_node, name, attributes = infer_func_form(node, nodes.Tuple._proxied,
+                                                   context=context)
+    fake = AstroidBuilder(MANAGER).string_build('''
+class %(name)s(tuple):
+    _fields = %(fields)r
+    def _asdict(self):
+        return self.__dict__
+    @classmethod
+    def _make(cls, iterable, new=tuple.__new__, len=len):
+        return new(cls, iterable)
+    def _replace(_self, **kwds):
+        result = _self._make(map(kwds.pop, %(fields)r, _self))
+        if kwds:
+            raise ValueError('Got unexpected field names: %%r' %% list(kwds))
+        return result
+    ''' % {'name': name, 'fields': attributes})
+    class_node.locals['_asdict'] = fake.body[0].locals['_asdict']
+    class_node.locals['_make'] = fake.body[0].locals['_make']
+    class_node.locals['_replace'] = fake.body[0].locals['_replace']
+    class_node.locals['_fields'] = fake.body[0].locals['_fields']
+    # we use UseInferenceDefault, we can't be a generator so return an iterator
+    return iter([class_node])
+
+def infer_enum(node, context=None):
+    """ Specific inference function for enum CallFunc node. """
+    enum_meta = nodes.Class("EnumMeta", 'docstring')
+    class_node = infer_func_form(node, enum_meta,
+                                 context=context, enum=True)[0]
+    return iter([class_node.instanciate_class()])
+
+def infer_enum_class(node, context=None):
+    """ Specific inference for enums. """
+    names = set(('Enum', 'IntEnum', 'enum.Enum', 'enum.IntEnum'))
+    for basename in node.basenames:
+        # TODO: doesn't handle subclasses yet.
+        if basename not in names:
+            continue
+        if node.root().name == 'enum':
+            # Skip if the class is directly from enum module.
+            break
+        for local, values in node.locals.items():
+            if any(not isinstance(value, nodes.AssName)
+                   for value in values):
+                continue
+            parent = values[0].parent
+            real_value = parent.value
+            new_targets = []
+            for target in parent.targets:
+                # Replace all the assignments with our mocked class.
+                classdef = dedent('''
+                class %(name)s(object):
+                    @property
+                    def value(self):
+                        return %(value)s
+                    @property
+                    def name(self):
+                        return %(name)r
+                    %(name)s = %(value)s
+                ''' % {'name': target.name,
+                       'value': real_value.as_string()})
+                fake = AstroidBuilder(MANAGER).string_build(classdef)[target.name]
+                fake.parent = target.parent
+                for method in node.mymethods():
+                    fake.locals[method.name] = [method]
+                new_targets.append(fake.instanciate_class())
+            node.locals[local] = new_targets
+        break
+    return node
+
+MANAGER.register_transform(nodes.CallFunc, inference_tip(infer_named_tuple),
+                           AsStringRegexpPredicate('namedtuple', 'func'))
+MANAGER.register_transform(nodes.CallFunc, inference_tip(infer_enum),
+                           AsStringRegexpPredicate('Enum', 'func'))
+MANAGER.register_transform(nodes.Class, infer_enum_class)