Add pylint to depot_tools.

third_party/logilab/astng/builder.py

+# copyright 2003-2011 LOGILAB S.A. (Paris, FRANCE), all rights reserved.
+# contact http://www.logilab.fr/ -- mailto:contact@logilab.fr
+# copyright 2003-2010 Sylvain Thenault, all rights reserved.
+# contact mailto:thenault@gmail.com
+#
+# This file is part of logilab-astng.
+#
+# logilab-astng 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.
+#
+# logilab-astng 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 logilab-astng. If not, see <http://www.gnu.org/licenses/>.
+"""The ASTNGBuilder makes astng from living object and / or from _ast
+
+The builder is not thread safe and can't be used to parse different sources
+at the same time.
+"""
+
+__docformat__ = "restructuredtext en"
+
+import sys, re
+from os.path import splitext, basename, dirname, exists, abspath
+
+from logilab.common.modutils import modpath_from_file
+
+from logilab.astng.exceptions import ASTNGBuildingException, InferenceError
+from logilab.astng.raw_building import InspectBuilder
+from logilab.astng.rebuilder import TreeRebuilder
+from logilab.astng.manager import ASTNGManager
+from logilab.astng.bases import YES, Instance
+
+from _ast import PyCF_ONLY_AST
+def parse(string):
+    return compile(string, "<string>", 'exec', PyCF_ONLY_AST)
+
+if sys.version_info >= (3, 0):
+    from tokenize import detect_encoding
+
+    def open_source_file(filename):
+        byte_stream = open(filename, 'bU')
+        encoding = detect_encoding(byte_stream.readline)[0]
+        stream = open(filename, 'U', encoding=encoding)
+        try:
+            data = stream.read()
+        except UnicodeError, uex: # wrong encodingg
+            # detect_encoding returns utf-8 if no encoding specified
+            msg = 'Wrong (%s) or no encoding specified' % encoding
+            raise ASTNGBuildingException(msg)
+        return stream, encoding, data
+
+else:
+    import re
+
+    _ENCODING_RGX = re.compile("\s*#+.*coding[:=]\s*([-\w.]+)")
+
+    def _guess_encoding(string):
+        """get encoding from a python file as string or return None if not found
+        """
+        # check for UTF-8 byte-order mark
+        if string.startswith('\xef\xbb\xbf'):
+            return 'UTF-8'
+        for line in string.split('\n', 2)[:2]:
+            # check for encoding declaration
+            match = _ENCODING_RGX.match(line)
+            if match is not None:
+                return match.group(1)
+
+    def open_source_file(filename):
+        """get data for parsing a file"""
+        stream = open(filename, 'U')
+        data = stream.read()
+        encoding = _guess_encoding(data)
+        return stream, encoding, data
+
+# ast NG builder ##############################################################
+
+MANAGER = ASTNGManager()
+
+class ASTNGBuilder(InspectBuilder):
+    """provide astng building methods"""
+    rebuilder = TreeRebuilder()
+
+    def __init__(self, manager=None):
+        self._manager = manager or MANAGER
+
+    def module_build(self, module, modname=None):
+        """build an astng from a living module instance
+        """
+        node = None
+        path = getattr(module, '__file__', None)
+        if path is not None:
+            path_, ext = splitext(module.__file__)
+            if ext in ('.py', '.pyc', '.pyo') and exists(path_ + '.py'):
+                node = self.file_build(path_ + '.py', modname)
+        if node is None:
+            # this is a built-in module
+            # get a partial representation by introspection
+            node = self.inspect_build(module, modname=modname, path=path)
+        return node
+
+    def file_build(self, path, modname=None):
+        """build astng from a source code file (i.e. from an ast)
+
+        path is expected to be a python source file
+        """
+        try:
+            stream, encoding, data = open_source_file(path)
+        except IOError, exc:
+            msg = 'Unable to load file %r (%s)' % (path, exc)
+            raise ASTNGBuildingException(msg)
+        except SyntaxError, exc: # py3k encoding specification error
+            raise ASTNGBuildingException(exc)
+        except LookupError, exc: # unknown encoding
+            raise ASTNGBuildingException(exc)
+        # get module name if necessary
+        if modname is None:
+            try:
+                modname = '.'.join(modpath_from_file(path))
+            except ImportError:
+                modname = splitext(basename(path))[0]
+        # build astng representation
+        node = self.string_build(data, modname, path)
+        node.file_encoding = encoding
+        return node
+
+    def string_build(self, data, modname='', path=None):
+        """build astng from source code string and return rebuilded astng"""
+        module = self._data_build(data, modname, path)
+        self._manager.astng_cache[module.name] = module
+        # post tree building steps after we stored the module in the cache:
+        for from_node in module._from_nodes:
+            self.add_from_names_to_locals(from_node)
+        # handle delayed assattr nodes
+        for delayed in module._delayed_assattr:
+            self.delayed_assattr(delayed)
+        if modname:
+            for transformer in self._manager.transformers:
+                transformer(module)
+        return module
+
+    def _data_build(self, data, modname, path):
+        """build tree node from data and add some informations"""
+        # this method could be wrapped with a pickle/cache function
+        node = parse(data + '\n')
+        if path is not None:
+            node_file = abspath(path)
+        else:
+            node_file = '<?>'
+        if modname.endswith('.__init__'):
+            modname = modname[:-9]
+            package = True
+        else:
+            package = path and path.find('__init__.py') > -1 or False
+        self.rebuilder.init()
+        module = self.rebuilder.visit_module(node, modname, package)
+        module.file = module.path = node_file
+        module._from_nodes = self.rebuilder._from_nodes
+        module._delayed_assattr = self.rebuilder._delayed_assattr
+        return module
+
+    def add_from_names_to_locals(self, node):
+        """store imported names to the locals;
+        resort the locals if coming from a delayed node
+        """
+
+        _key_func = lambda node: node.fromlineno
+        def sort_locals(my_list):
+            my_list.sort(key=_key_func)
+        for (name, asname) in node.names:
+            if name == '*':
+                try:
+                    imported = node.root().import_module(node.modname)
+                except ASTNGBuildingException:
+                    continue
+                for name in imported.wildcard_import_names():
+                    node.parent.set_local(name, node)
+                    sort_locals(node.parent.scope().locals[name])
+            else:
+                node.parent.set_local(asname or name, node)
+                sort_locals(node.parent.scope().locals[asname or name])
+
+    def delayed_assattr(self, node):
+        """visit a AssAttr node -> add name to locals, handle members
+        definition
+        """
+        try:
+            frame = node.frame()
+            for infered in node.expr.infer():
+                if infered is YES:
+                    continue
+                try:
+                    if infered.__class__ is Instance:
+                        infered = infered._proxied
+                        iattrs = infered.instance_attrs
+                    elif isinstance(infered, Instance):
+                        # Const, Tuple, ... we may be wrong, may be not, but
+                        # anyway we don't want to pollute builtin's namespace
+                        continue
+                    elif infered.is_function:
+                        iattrs = infered.instance_attrs
+                    else:
+                        iattrs = infered.locals
+                except AttributeError:
+                    # XXX log error
+                    #import traceback
+                    #traceback.print_exc()
+                    continue
+                values = iattrs.setdefault(node.attrname, [])
+                if node in values:
+                    continue
+                # get assign in __init__ first XXX useful ?
+                if frame.name == '__init__' and values and not \
+                       values[0].frame().name == '__init__':
+                    values.insert(0, node)
+                else:
+                    values.append(node)
+        except InferenceError:
+            pass
+