Index: third_party/logilab/astroid/utils.py |
=================================================================== |
--- third_party/logilab/astroid/utils.py (revision 0) |
+++ third_party/logilab/astroid/utils.py (working copy) |
@@ -0,0 +1,238 @@ |
+# 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/>. |
+"""this module contains some utilities to navigate in the tree or to |
+extract information from it |
+""" |
+ |
+__docformat__ = "restructuredtext en" |
+ |
+from astroid.exceptions import AstroidBuildingException |
+from astroid.builder import parse |
+ |
+ |
+class ASTWalker(object): |
+ """a walker visiting a tree in preorder, calling on the handler: |
+ |
+ * visit_<class name> on entering a node, where class name is the class of |
+ the node in lower case |
+ |
+ * leave_<class name> on leaving a node, where class name is the class of |
+ the node in lower case |
+ """ |
+ |
+ def __init__(self, handler): |
+ self.handler = handler |
+ self._cache = {} |
+ |
+ def walk(self, node, _done=None): |
+ """walk on the tree from <node>, getting callbacks from handler""" |
+ if _done is None: |
+ _done = set() |
+ if node in _done: |
+ raise AssertionError((id(node), node, node.parent)) |
+ _done.add(node) |
+ self.visit(node) |
+ for child_node in node.get_children(): |
+ self.handler.set_context(node, child_node) |
+ assert child_node is not node |
+ self.walk(child_node, _done) |
+ self.leave(node) |
+ assert node.parent is not node |
+ |
+ def get_callbacks(self, node): |
+ """get callbacks from handler for the visited node""" |
+ klass = node.__class__ |
+ methods = self._cache.get(klass) |
+ if methods is None: |
+ handler = self.handler |
+ kid = klass.__name__.lower() |
+ e_method = getattr(handler, 'visit_%s' % kid, |
+ getattr(handler, 'visit_default', None)) |
+ l_method = getattr(handler, 'leave_%s' % kid, |
+ getattr(handler, 'leave_default', None)) |
+ self._cache[klass] = (e_method, l_method) |
+ else: |
+ e_method, l_method = methods |
+ return e_method, l_method |
+ |
+ def visit(self, node): |
+ """walk on the tree from <node>, getting callbacks from handler""" |
+ method = self.get_callbacks(node)[0] |
+ if method is not None: |
+ method(node) |
+ |
+ def leave(self, node): |
+ """walk on the tree from <node>, getting callbacks from handler""" |
+ method = self.get_callbacks(node)[1] |
+ if method is not None: |
+ method(node) |
+ |
+ |
+class LocalsVisitor(ASTWalker): |
+ """visit a project by traversing the locals dictionary""" |
+ def __init__(self): |
+ ASTWalker.__init__(self, self) |
+ self._visited = {} |
+ |
+ def visit(self, node): |
+ """launch the visit starting from the given node""" |
+ if node in self._visited: |
+ return |
+ self._visited[node] = 1 # FIXME: use set ? |
+ methods = self.get_callbacks(node) |
+ if methods[0] is not None: |
+ methods[0](node) |
+ if 'locals' in node.__dict__: # skip Instance and other proxy |
+ for local_node in node.values(): |
+ self.visit(local_node) |
+ if methods[1] is not None: |
+ return methods[1](node) |
+ |
+ |
+def _check_children(node): |
+ """a helper function to check children - parent relations""" |
+ for child in node.get_children(): |
+ ok = False |
+ if child is None: |
+ print "Hm, child of %s is None" % node |
+ continue |
+ if not hasattr(child, 'parent'): |
+ print " ERROR: %s has child %s %x with no parent" % ( |
+ node, child, id(child)) |
+ elif not child.parent: |
+ print " ERROR: %s has child %s %x with parent %r" % ( |
+ node, child, id(child), child.parent) |
+ elif child.parent is not node: |
+ print " ERROR: %s %x has child %s %x with wrong parent %s" % ( |
+ node, id(node), child, id(child), child.parent) |
+ else: |
+ ok = True |
+ if not ok: |
+ print "lines;", node.lineno, child.lineno |
+ print "of module", node.root(), node.root().name |
+ raise AstroidBuildingException |
+ _check_children(child) |
+ |
+ |
+class TreeTester(object): |
+ '''A helper class to see _ast tree and compare with astroid tree |
+ |
+ indent: string for tree indent representation |
+ lineno: bool to tell if we should print the line numbers |
+ |
+ >>> tester = TreeTester('print') |
+ >>> print tester.native_tree_repr() |
+ |
+ <Module> |
+ . body = [ |
+ . <Print> |
+ . . nl = True |
+ . ] |
+ >>> print tester.astroid_tree_repr() |
+ Module() |
+ body = [ |
+ Print() |
+ dest = |
+ values = [ |
+ ] |
+ ] |
+ ''' |
+ |
+ indent = '. ' |
+ lineno = False |
+ |
+ def __init__(self, sourcecode): |
+ self._string = '' |
+ self.sourcecode = sourcecode |
+ self._ast_node = None |
+ self.build_ast() |
+ |
+ def build_ast(self): |
+ """build the _ast tree from the source code""" |
+ self._ast_node = parse(self.sourcecode) |
+ |
+ def native_tree_repr(self, node=None, indent=''): |
+ """get a nice representation of the _ast tree""" |
+ self._string = '' |
+ if node is None: |
+ node = self._ast_node |
+ self._native_repr_tree(node, indent) |
+ return self._string |
+ |
+ |
+ def _native_repr_tree(self, node, indent, _done=None): |
+ """recursive method for the native tree representation""" |
+ from _ast import Load as _Load, Store as _Store, Del as _Del |
+ from _ast import AST as Node |
+ if _done is None: |
+ _done = set() |
+ if node in _done: |
+ self._string += '\nloop in tree: %r (%s)' % ( |
+ node, getattr(node, 'lineno', None)) |
+ return |
+ _done.add(node) |
+ self._string += '\n' + indent + '<%s>' % node.__class__.__name__ |
+ indent += self.indent |
+ if not hasattr(node, '__dict__'): |
+ self._string += '\n' + self.indent + " ** node has no __dict__ " + str(node) |
+ return |
+ node_dict = node.__dict__ |
+ if hasattr(node, '_attributes'): |
+ for a in node._attributes: |
+ attr = node_dict[a] |
+ if attr is None: |
+ continue |
+ if a in ("lineno", "col_offset") and not self.lineno: |
+ continue |
+ self._string += '\n' + indent + a + " = " + repr(attr) |
+ for field in node._fields or (): |
+ attr = node_dict[field] |
+ if attr is None: |
+ continue |
+ if isinstance(attr, list): |
+ if not attr: |
+ continue |
+ self._string += '\n' + indent + field + ' = [' |
+ for elt in attr: |
+ self._native_repr_tree(elt, indent, _done) |
+ self._string += '\n' + indent + ']' |
+ continue |
+ if isinstance(attr, (_Load, _Store, _Del)): |
+ continue |
+ if isinstance(attr, Node): |
+ self._string += '\n' + indent + field + " = " |
+ self._native_repr_tree(attr, indent, _done) |
+ else: |
+ self._string += '\n' + indent + field + " = " + repr(attr) |
+ |
+ |
+ def build_astroid_tree(self): |
+ """build astroid tree from the _ast tree |
+ """ |
+ from astroid.builder import AstroidBuilder |
+ tree = AstroidBuilder().string_build(self.sourcecode) |
+ return tree |
+ |
+ def astroid_tree_repr(self, ids=False): |
+ """build the astroid tree and return a nice tree representation""" |
+ mod = self.build_astroid_tree() |
+ return mod.repr_tree(ids) |
+ |
+ |
+__all__ = ('LocalsVisitor', 'ASTWalker',) |
+ |