# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1337367101 -7200
# Node ID 7bec0014e8711e78c22a1cfd621abb36c161fc9f

The compiler package from Python 2.6.8 together with copyright and licensing information.

diff -r 000000000000 -r 7bec0014e871 compiler/__init__.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/compiler/__init__.py	Fri May 18 20:51:41 2012 +0200
@@ -0,0 +1,29 @@
+"""Package for parsing and compiling Python source code
+
+There are several functions defined at the top level that are imported
+from modules contained in the package.
+
+parse(buf, mode="exec") -> AST
+    Converts a string containing Python source code to an abstract
+    syntax tree (AST).  The AST is defined in compiler.ast.
+
+parseFile(path) -> AST
+    The same as parse(open(path))
+
+walk(ast, visitor, verbose=None)
+    Does a pre-order walk over the ast using the visitor instance.
+    See compiler.visitor for details.
+
+compile(source, filename, mode, flags=None, dont_inherit=None)
+    Returns a code object.  A replacement for the builtin compile() function.
+
+compileFile(filename)
+    Generates a .pyc file by compiling filename.
+"""
+from warnings import warnpy3k
+warnpy3k("the compiler package has been removed in Python 3.0", stacklevel=2)
+del warnpy3k
+
+from compiler.transformer import parse, parseFile
+from compiler.visitor import walk
+from compiler.pycodegen import compile, compileFile
diff -r 000000000000 -r 7bec0014e871 compiler/ast.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/compiler/ast.py	Fri May 18 20:51:41 2012 +0200
@@ -0,0 +1,1358 @@
+"""Python abstract syntax node definitions
+
+This file is automatically generated by Tools/compiler/astgen.py
+"""
+from compiler.consts import CO_VARARGS, CO_VARKEYWORDS
+
+def flatten(seq):
+    l = []
+    for elt in seq:
+        t = type(elt)
+        if t is tuple or t is list:
+            for elt2 in flatten(elt):
+                l.append(elt2)
+        else:
+            l.append(elt)
+    return l
+
+def flatten_nodes(seq):
+    return [n for n in flatten(seq) if isinstance(n, Node)]
+
+nodes = {}
+
+class Node:
+    """Abstract base class for ast nodes."""
+    def getChildren(self):
+        pass # implemented by subclasses
+    def __iter__(self):
+        for n in self.getChildren():
+            yield n
+    def asList(self): # for backwards compatibility
+        return self.getChildren()
+    def getChildNodes(self):
+        pass # implemented by subclasses
+
+class EmptyNode(Node):
+    pass
+
+class Expression(Node):
+    # Expression is an artificial node class to support "eval"
+    nodes["expression"] = "Expression"
+    def __init__(self, node):
+        self.node = node
+
+    def getChildren(self):
+        return self.node,
+
+    def getChildNodes(self):
+        return self.node,
+
+    def __repr__(self):
+        return "Expression(%s)" % (repr(self.node))
+
+class Add(Node):
+    def __init__(self, leftright, lineno=None):
+        self.left = leftright[0]
+        self.right = leftright[1]
+        self.lineno = lineno
+
+    def getChildren(self):
+        return self.left, self.right
+
+    def getChildNodes(self):
+        return self.left, self.right
+
+    def __repr__(self):
+        return "Add((%s, %s))" % (repr(self.left), repr(self.right))
+
+class And(Node):
+    def __init__(self, nodes, lineno=None):
+        self.nodes = nodes
+        self.lineno = lineno
+
+    def getChildren(self):
+        return tuple(flatten(self.nodes))
+
+    def getChildNodes(self):
+        nodelist = []
+        nodelist.extend(flatten_nodes(self.nodes))
+        return tuple(nodelist)
+
+    def __repr__(self):
+        return "And(%s)" % (repr(self.nodes),)
+
+class AssAttr(Node):
+    def __init__(self, expr, attrname, flags, lineno=None):
+        self.expr = expr
+        self.attrname = attrname
+        self.flags = flags
+        self.lineno = lineno
+
+    def getChildren(self):
+        return self.expr, self.attrname, self.flags
+
+    def getChildNodes(self):
+        return self.expr,
+
+    def __repr__(self):
+        return "AssAttr(%s, %s, %s)" % (repr(self.expr), repr(self.attrname), repr(self.flags))
+
+class AssList(Node):
+    def __init__(self, nodes, lineno=None):
+        self.nodes = nodes
+        self.lineno = lineno
+
+    def getChildren(self):
+        return tuple(flatten(self.nodes))
+
+    def getChildNodes(self):
+        nodelist = []
+        nodelist.extend(flatten_nodes(self.nodes))
+        return tuple(nodelist)
+
+    def __repr__(self):
+        return "AssList(%s)" % (repr(self.nodes),)
+
+class AssName(Node):
+    def __init__(self, name, flags, lineno=None):
+        self.name = name
+        self.flags = flags
+        self.lineno = lineno
+
+    def getChildren(self):
+        return self.name, self.flags
+
+    def getChildNodes(self):
+        return ()
+
+    def __repr__(self):
+        return "AssName(%s, %s)" % (repr(self.name), repr(self.flags))
+
+class AssTuple(Node):
+    def __init__(self, nodes, lineno=None):
+        self.nodes = nodes
+        self.lineno = lineno
+
+    def getChildren(self):
+        return tuple(flatten(self.nodes))
+
+    def getChildNodes(self):
+        nodelist = []
+        nodelist.extend(flatten_nodes(self.nodes))
+        return tuple(nodelist)
+
+    def __repr__(self):
+        return "AssTuple(%s)" % (repr(self.nodes),)
+
+class Assert(Node):
+    def __init__(self, test, fail, lineno=None):
+        self.test = test
+        self.fail = fail
+        self.lineno = lineno
+
+    def getChildren(self):
+        children = []
+        children.append(self.test)
+        children.append(self.fail)
+        return tuple(children)
+
+    def getChildNodes(self):
+        nodelist = []
+        nodelist.append(self.test)
+        if self.fail is not None:
+            nodelist.append(self.fail)
+        return tuple(nodelist)
+
+    def __repr__(self):
+        return "Assert(%s, %s)" % (repr(self.test), repr(self.fail))
+
+class Assign(Node):
+    def __init__(self, nodes, expr, lineno=None):
+        self.nodes = nodes
+        self.expr = expr
+        self.lineno = lineno
+
+    def getChildren(self):
+        children = []
+        children.extend(flatten(self.nodes))
+        children.append(self.expr)
+        return tuple(children)
+
+    def getChildNodes(self):
+        nodelist = []
+        nodelist.extend(flatten_nodes(self.nodes))
+        nodelist.append(self.expr)
+        return tuple(nodelist)
+
+    def __repr__(self):
+        return "Assign(%s, %s)" % (repr(self.nodes), repr(self.expr))
+
+class AugAssign(Node):
+    def __init__(self, node, op, expr, lineno=None):
+        self.node = node
+        self.op = op
+        self.expr = expr
+        self.lineno = lineno
+
+    def getChildren(self):
+        return self.node, self.op, self.expr
+
+    def getChildNodes(self):
+        return self.node, self.expr
+
+    def __repr__(self):
+        return "AugAssign(%s, %s, %s)" % (repr(self.node), repr(self.op), repr(self.expr))
+
+class Backquote(Node):
+    def __init__(self, expr, lineno=None):
+        self.expr = expr
+        self.lineno = lineno
+
+    def getChildren(self):
+        return self.expr,
+
+    def getChildNodes(self):
+        return self.expr,
+
+    def __repr__(self):
+        return "Backquote(%s)" % (repr(self.expr),)
+
+class Bitand(Node):
+    def __init__(self, nodes, lineno=None):
+        self.nodes = nodes
+        self.lineno = lineno
+
+    def getChildren(self):
+        return tuple(flatten(self.nodes))
+
+    def getChildNodes(self):
+        nodelist = []
+        nodelist.extend(flatten_nodes(self.nodes))
+        return tuple(nodelist)
+
+    def __repr__(self):
+        return "Bitand(%s)" % (repr(self.nodes),)
+
+class Bitor(Node):
+    def __init__(self, nodes, lineno=None):
+        self.nodes = nodes
+        self.lineno = lineno
+
+    def getChildren(self):
+        return tuple(flatten(self.nodes))
+
+    def getChildNodes(self):
+        nodelist = []
+        nodelist.extend(flatten_nodes(self.nodes))
+        return tuple(nodelist)
+
+    def __repr__(self):
+        return "Bitor(%s)" % (repr(self.nodes),)
+
+class Bitxor(Node):
+    def __init__(self, nodes, lineno=None):
+        self.nodes = nodes
+        self.lineno = lineno
+
+    def getChildren(self):
+        return tuple(flatten(self.nodes))
+
+    def getChildNodes(self):
+        nodelist = []
+        nodelist.extend(flatten_nodes(self.nodes))
+        return tuple(nodelist)
+
+    def __repr__(self):
+        return "Bitxor(%s)" % (repr(self.nodes),)
+
+class Break(Node):
+    def __init__(self, lineno=None):
+        self.lineno = lineno
+
+    def getChildren(self):
+        return ()
+
+    def getChildNodes(self):
+        return ()
+
+    def __repr__(self):
+        return "Break()"
+
+class CallFunc(Node):
+    def __init__(self, node, args, star_args = None, dstar_args = None, lineno=None):
+        self.node = node
+        self.args = args
+        self.star_args = star_args
+        self.dstar_args = dstar_args
+        self.lineno = lineno
+
+    def getChildren(self):
+        children = []
+        children.append(self.node)
+        children.extend(flatten(self.args))
+        children.append(self.star_args)
+        children.append(self.dstar_args)
+        return tuple(children)
+
+    def getChildNodes(self):
+        nodelist = []
+        nodelist.append(self.node)
+        nodelist.extend(flatten_nodes(self.args))
+        if self.star_args is not None:
+            nodelist.append(self.star_args)
+        if self.dstar_args is not None:
+            nodelist.append(self.dstar_args)
+        return tuple(nodelist)
+
+    def __repr__(self):
+        return "CallFunc(%s, %s, %s, %s)" % (repr(self.node), repr(self.args), repr(self.star_args), repr(self.dstar_args))
+
+class Class(Node):
+    def __init__(self, name, bases, doc, code, decorators = None, lineno=None):
+        self.name = name
+        self.bases = bases
+        self.doc = doc
+        self.code = code
+        self.decorators = decorators
+        self.lineno = lineno
+
+    def getChildren(self):
+        children = []
+        children.append(self.name)
+        children.extend(flatten(self.bases))
+        children.append(self.doc)
+        children.append(self.code)
+        children.append(self.decorators)
+        return tuple(children)
+
+    def getChildNodes(self):
+        nodelist = []
+        nodelist.extend(flatten_nodes(self.bases))
+        nodelist.append(self.code)
+        if self.decorators is not None:
+            nodelist.append(self.decorators)
+        return tuple(nodelist)
+
+    def __repr__(self):
+        return "Class(%s, %s, %s, %s, %s)" % (repr(self.name), repr(self.bases), repr(self.doc), repr(self.code), repr(self.decorators))
+
+class Compare(Node):
+    def __init__(self, expr, ops, lineno=None):
+        self.expr = expr
+        self.ops = ops
+        self.lineno = lineno
+
+    def getChildren(self):
+        children = []
+        children.append(self.expr)
+        children.extend(flatten(self.ops))
+        return tuple(children)
+
+    def getChildNodes(self):
+        nodelist = []
+        nodelist.append(self.expr)
+        nodelist.extend(flatten_nodes(self.ops))
+        return tuple(nodelist)
+
+    def __repr__(self):
+        return "Compare(%s, %s)" % (repr(self.expr), repr(self.ops))
+
+class Const(Node):
+    def __init__(self, value, lineno=None):
+        self.value = value
+        self.lineno = lineno
+
+    def getChildren(self):
+        return self.value,
+
+    def getChildNodes(self):
+        return ()
+
+    def __repr__(self):
+        return "Const(%s)" % (repr(self.value),)
+
+class Continue(Node):
+    def __init__(self, lineno=None):
+        self.lineno = lineno
+
+    def getChildren(self):
+        return ()
+
+    def getChildNodes(self):
+        return ()
+
+    def __repr__(self):
+        return "Continue()"
+
+class Decorators(Node):
+    def __init__(self, nodes, lineno=None):
+        self.nodes = nodes
+        self.lineno = lineno
+
+    def getChildren(self):
+        return tuple(flatten(self.nodes))
+
+    def getChildNodes(self):
+        nodelist = []
+        nodelist.extend(flatten_nodes(self.nodes))
+        return tuple(nodelist)
+
+    def __repr__(self):
+        return "Decorators(%s)" % (repr(self.nodes),)
+
+class Dict(Node):
+    def __init__(self, items, lineno=None):
+        self.items = items
+        self.lineno = lineno
+
+    def getChildren(self):
+        return tuple(flatten(self.items))
+
+    def getChildNodes(self):
+        nodelist = []
+        nodelist.extend(flatten_nodes(self.items))
+        return tuple(nodelist)
+
+    def __repr__(self):
+        return "Dict(%s)" % (repr(self.items),)
+
+class Discard(Node):
+    def __init__(self, expr, lineno=None):
+        self.expr = expr
+        self.lineno = lineno
+
+    def getChildren(self):
+        return self.expr,
+
+    def getChildNodes(self):
+        return self.expr,
+
+    def __repr__(self):
+        return "Discard(%s)" % (repr(self.expr),)
+
+class Div(Node):
+    def __init__(self, leftright, lineno=None):
+        self.left = leftright[0]
+        self.right = leftright[1]
+        self.lineno = lineno
+
+    def getChildren(self):
+        return self.left, self.right
+
+    def getChildNodes(self):
+        return self.left, self.right
+
+    def __repr__(self):
+        return "Div((%s, %s))" % (repr(self.left), repr(self.right))
+
+class Ellipsis(Node):
+    def __init__(self, lineno=None):
+        self.lineno = lineno
+
+    def getChildren(self):
+        return ()
+
+    def getChildNodes(self):
+        return ()
+
+    def __repr__(self):
+        return "Ellipsis()"
+
+class Exec(Node):
+    def __init__(self, expr, locals, globals, lineno=None):
+        self.expr = expr
+        self.locals = locals
+        self.globals = globals
+        self.lineno = lineno
+
+    def getChildren(self):
+        children = []
+        children.append(self.expr)
+        children.append(self.locals)
+        children.append(self.globals)
+        return tuple(children)
+
+    def getChildNodes(self):
+        nodelist = []
+        nodelist.append(self.expr)
+        if self.locals is not None:
+            nodelist.append(self.locals)
+        if self.globals is not None:
+            nodelist.append(self.globals)
+        return tuple(nodelist)
+
+    def __repr__(self):
+        return "Exec(%s, %s, %s)" % (repr(self.expr), repr(self.locals), repr(self.globals))
+
+class FloorDiv(Node):
+    def __init__(self, leftright, lineno=None):
+        self.left = leftright[0]
+        self.right = leftright[1]
+        self.lineno = lineno
+
+    def getChildren(self):
+        return self.left, self.right
+
+    def getChildNodes(self):
+        return self.left, self.right
+
+    def __repr__(self):
+        return "FloorDiv((%s, %s))" % (repr(self.left), repr(self.right))
+
+class For(Node):
+    def __init__(self, assign, list, body, else_, lineno=None):
+        self.assign = assign
+        self.list = list
+        self.body = body
+        self.else_ = else_
+        self.lineno = lineno
+
+    def getChildren(self):
+        children = []
+        children.append(self.assign)
+        children.append(self.list)
+        children.append(self.body)
+        children.append(self.else_)
+        return tuple(children)
+
+    def getChildNodes(self):
+        nodelist = []
+        nodelist.append(self.assign)
+        nodelist.append(self.list)
+        nodelist.append(self.body)
+        if self.else_ is not None:
+            nodelist.append(self.else_)
+        return tuple(nodelist)
+
+    def __repr__(self):
+        return "For(%s, %s, %s, %s)" % (repr(self.assign), repr(self.list), repr(self.body), repr(self.else_))
+
+class From(Node):
+    def __init__(self, modname, names, level, lineno=None):
+        self.modname = modname
+        self.names = names
+        self.level = level
+        self.lineno = lineno
+
+    def getChildren(self):
+        return self.modname, self.names, self.level
+
+    def getChildNodes(self):
+        return ()
+
+    def __repr__(self):
+        return "From(%s, %s, %s)" % (repr(self.modname), repr(self.names), repr(self.level))
+
+class Function(Node):
+    def __init__(self, decorators, name, argnames, defaults, flags, doc, code, lineno=None):
+        self.decorators = decorators
+        self.name = name
+        self.argnames = argnames
+        self.defaults = defaults
+        self.flags = flags
+        self.doc = doc
+        self.code = code
+        self.lineno = lineno
+        self.varargs = self.kwargs = None
+        if flags & CO_VARARGS:
+            self.varargs = 1
+        if flags & CO_VARKEYWORDS:
+            self.kwargs = 1
+
+
+    def getChildren(self):
+        children = []
+        children.append(self.decorators)
+        children.append(self.name)
+        children.append(self.argnames)
+        children.extend(flatten(self.defaults))
+        children.append(self.flags)
+        children.append(self.doc)
+        children.append(self.code)
+        return tuple(children)
+
+    def getChildNodes(self):
+        nodelist = []
+        if self.decorators is not None:
+            nodelist.append(self.decorators)
+        nodelist.extend(flatten_nodes(self.defaults))
+        nodelist.append(self.code)
+        return tuple(nodelist)
+
+    def __repr__(self):
+        return "Function(%s, %s, %s, %s, %s, %s, %s)" % (repr(self.decorators), repr(self.name), repr(self.argnames), repr(self.defaults), repr(self.flags), repr(self.doc), repr(self.code))
+
+class GenExpr(Node):
+    def __init__(self, code, lineno=None):
+        self.code = code
+        self.lineno = lineno
+        self.argnames = ['.0']
+        self.varargs = self.kwargs = None
+
+
+    def getChildren(self):
+        return self.code,
+
+    def getChildNodes(self):
+        return self.code,
+
+    def __repr__(self):
+        return "GenExpr(%s)" % (repr(self.code),)
+
+class GenExprFor(Node):
+    def __init__(self, assign, iter, ifs, lineno=None):
+        self.assign = assign
+        self.iter = iter
+        self.ifs = ifs
+        self.lineno = lineno
+        self.is_outmost = False
+
+    def getChildren(self):
+        children = []
+        children.append(self.assign)
+        children.append(self.iter)
+        children.extend(flatten(self.ifs))
+        return tuple(children)
+
+    def getChildNodes(self):
+        nodelist = []
+        nodelist.append(self.assign)
+        nodelist.append(self.iter)
+        nodelist.extend(flatten_nodes(self.ifs))
+        return tuple(nodelist)
+
+    def __repr__(self):
+        return "GenExprFor(%s, %s, %s)" % (repr(self.assign), repr(self.iter), repr(self.ifs))
+
+class GenExprIf(Node):
+    def __init__(self, test, lineno=None):
+        self.test = test
+        self.lineno = lineno
+
+    def getChildren(self):
+        return self.test,
+
+    def getChildNodes(self):
+        return self.test,
+
+    def __repr__(self):
+        return "GenExprIf(%s)" % (repr(self.test),)
+
+class GenExprInner(Node):
+    def __init__(self, expr, quals, lineno=None):
+        self.expr = expr
+        self.quals = quals
+        self.lineno = lineno
+
+    def getChildren(self):
+        children = []
+        children.append(self.expr)
+        children.extend(flatten(self.quals))
+        return tuple(children)
+
+    def getChildNodes(self):
+        nodelist = []
+        nodelist.append(self.expr)
+        nodelist.extend(flatten_nodes(self.quals))
+        return tuple(nodelist)
+
+    def __repr__(self):
+        return "GenExprInner(%s, %s)" % (repr(self.expr), repr(self.quals))
+
+class Getattr(Node):
+    def __init__(self, expr, attrname, lineno=None):
+        self.expr = expr
+        self.attrname = attrname
+        self.lineno = lineno
+
+    def getChildren(self):
+        return self.expr, self.attrname
+
+    def getChildNodes(self):
+        return self.expr,
+
+    def __repr__(self):
+        return "Getattr(%s, %s)" % (repr(self.expr), repr(self.attrname))
+
+class Global(Node):
+    def __init__(self, names, lineno=None):
+        self.names = names
+        self.lineno = lineno
+
+    def getChildren(self):
+        return self.names,
+
+    def getChildNodes(self):
+        return ()
+
+    def __repr__(self):
+        return "Global(%s)" % (repr(self.names),)
+
+class If(Node):
+    def __init__(self, tests, else_, lineno=None):
+        self.tests = tests
+        self.else_ = else_
+        self.lineno = lineno
+
+    def getChildren(self):
+        children = []
+        children.extend(flatten(self.tests))
+        children.append(self.else_)
+        return tuple(children)
+
+    def getChildNodes(self):
+        nodelist = []
+        nodelist.extend(flatten_nodes(self.tests))
+        if self.else_ is not None:
+            nodelist.append(self.else_)
+        return tuple(nodelist)
+
+    def __repr__(self):
+        return "If(%s, %s)" % (repr(self.tests), repr(self.else_))
+
+class IfExp(Node):
+    def __init__(self, test, then, else_, lineno=None):
+        self.test = test
+        self.then = then
+        self.else_ = else_
+        self.lineno = lineno
+
+    def getChildren(self):
+        return self.test, self.then, self.else_
+
+    def getChildNodes(self):
+        return self.test, self.then, self.else_
+
+    def __repr__(self):
+        return "IfExp(%s, %s, %s)" % (repr(self.test), repr(self.then), repr(self.else_))
+
+class Import(Node):
+    def __init__(self, names, lineno=None):
+        self.names = names
+        self.lineno = lineno
+
+    def getChildren(self):
+        return self.names,
+
+    def getChildNodes(self):
+        return ()
+
+    def __repr__(self):
+        return "Import(%s)" % (repr(self.names),)
+
+class Invert(Node):
+    def __init__(self, expr, lineno=None):
+        self.expr = expr
+        self.lineno = lineno
+
+    def getChildren(self):
+        return self.expr,
+
+    def getChildNodes(self):
+        return self.expr,
+
+    def __repr__(self):
+        return "Invert(%s)" % (repr(self.expr),)
+
+class Keyword(Node):
+    def __init__(self, name, expr, lineno=None):
+        self.name = name
+        self.expr = expr
+        self.lineno = lineno
+
+    def getChildren(self):
+        return self.name, self.expr
+
+    def getChildNodes(self):
+        return self.expr,
+
+    def __repr__(self):
+        return "Keyword(%s, %s)" % (repr(self.name), repr(self.expr))
+
+class Lambda(Node):
+    def __init__(self, argnames, defaults, flags, code, lineno=None):
+        self.argnames = argnames
+        self.defaults = defaults
+        self.flags = flags
+        self.code = code
+        self.lineno = lineno
+        self.varargs = self.kwargs = None
+        if flags & CO_VARARGS:
+            self.varargs = 1
+        if flags & CO_VARKEYWORDS:
+            self.kwargs = 1
+
+
+    def getChildren(self):
+        children = []
+        children.append(self.argnames)
+        children.extend(flatten(self.defaults))
+        children.append(self.flags)
+        children.append(self.code)
+        return tuple(children)
+
+    def getChildNodes(self):
+        nodelist = []
+        nodelist.extend(flatten_nodes(self.defaults))
+        nodelist.append(self.code)
+        return tuple(nodelist)
+
+    def __repr__(self):
+        return "Lambda(%s, %s, %s, %s)" % (repr(self.argnames), repr(self.defaults), repr(self.flags), repr(self.code))
+
+class LeftShift(Node):
+    def __init__(self, leftright, lineno=None):
+        self.left = leftright[0]
+        self.right = leftright[1]
+        self.lineno = lineno
+
+    def getChildren(self):
+        return self.left, self.right
+
+    def getChildNodes(self):
+        return self.left, self.right
+
+    def __repr__(self):
+        return "LeftShift((%s, %s))" % (repr(self.left), repr(self.right))
+
+class List(Node):
+    def __init__(self, nodes, lineno=None):
+        self.nodes = nodes
+        self.lineno = lineno
+
+    def getChildren(self):
+        return tuple(flatten(self.nodes))
+
+    def getChildNodes(self):
+        nodelist = []
+        nodelist.extend(flatten_nodes(self.nodes))
+        return tuple(nodelist)
+
+    def __repr__(self):
+        return "List(%s)" % (repr(self.nodes),)
+
+class ListComp(Node):
+    def __init__(self, expr, quals, lineno=None):
+        self.expr = expr
+        self.quals = quals
+        self.lineno = lineno
+
+    def getChildren(self):
+        children = []
+        children.append(self.expr)
+        children.extend(flatten(self.quals))
+        return tuple(children)
+
+    def getChildNodes(self):
+        nodelist = []
+        nodelist.append(self.expr)
+        nodelist.extend(flatten_nodes(self.quals))
+        return tuple(nodelist)
+
+    def __repr__(self):
+        return "ListComp(%s, %s)" % (repr(self.expr), repr(self.quals))
+
+class ListCompFor(Node):
+    def __init__(self, assign, list, ifs, lineno=None):
+        self.assign = assign
+        self.list = list
+        self.ifs = ifs
+        self.lineno = lineno
+
+    def getChildren(self):
+        children = []
+        children.append(self.assign)
+        children.append(self.list)
+        children.extend(flatten(self.ifs))
+        return tuple(children)
+
+    def getChildNodes(self):
+        nodelist = []
+        nodelist.append(self.assign)
+        nodelist.append(self.list)
+        nodelist.extend(flatten_nodes(self.ifs))
+        return tuple(nodelist)
+
+    def __repr__(self):
+        return "ListCompFor(%s, %s, %s)" % (repr(self.assign), repr(self.list), repr(self.ifs))
+
+class ListCompIf(Node):
+    def __init__(self, test, lineno=None):
+        self.test = test
+        self.lineno = lineno
+
+    def getChildren(self):
+        return self.test,
+
+    def getChildNodes(self):
+        return self.test,
+
+    def __repr__(self):
+        return "ListCompIf(%s)" % (repr(self.test),)
+
+class Mod(Node):
+    def __init__(self, leftright, lineno=None):
+        self.left = leftright[0]
+        self.right = leftright[1]
+        self.lineno = lineno
+
+    def getChildren(self):
+        return self.left, self.right
+
+    def getChildNodes(self):
+        return self.left, self.right
+
+    def __repr__(self):
+        return "Mod((%s, %s))" % (repr(self.left), repr(self.right))
+
+class Module(Node):
+    def __init__(self, doc, node, lineno=None):
+        self.doc = doc
+        self.node = node
+        self.lineno = lineno
+
+    def getChildren(self):
+        return self.doc, self.node
+
+    def getChildNodes(self):
+        return self.node,
+
+    def __repr__(self):
+        return "Module(%s, %s)" % (repr(self.doc), repr(self.node))
+
+class Mul(Node):
+    def __init__(self, leftright, lineno=None):
+        self.left = leftright[0]
+        self.right = leftright[1]
+        self.lineno = lineno
+
+    def getChildren(self):
+        return self.left, self.right
+
+    def getChildNodes(self):
+        return self.left, self.right
+
+    def __repr__(self):
+        return "Mul((%s, %s))" % (repr(self.left), repr(self.right))
+
+class Name(Node):
+    def __init__(self, name, lineno=None):
+        self.name = name
+        self.lineno = lineno
+
+    def getChildren(self):
+        return self.name,
+
+    def getChildNodes(self):
+        return ()
+
+    def __repr__(self):
+        return "Name(%s)" % (repr(self.name),)
+
+class Not(Node):
+    def __init__(self, expr, lineno=None):
+        self.expr = expr
+        self.lineno = lineno
+
+    def getChildren(self):
+        return self.expr,
+
+    def getChildNodes(self):
+        return self.expr,
+
+    def __repr__(self):
+        return "Not(%s)" % (repr(self.expr),)
+
+class Or(Node):
+    def __init__(self, nodes, lineno=None):
+        self.nodes = nodes
+        self.lineno = lineno
+
+    def getChildren(self):
+        return tuple(flatten(self.nodes))
+
+    def getChildNodes(self):
+        nodelist = []
+        nodelist.extend(flatten_nodes(self.nodes))
+        return tuple(nodelist)
+
+    def __repr__(self):
+        return "Or(%s)" % (repr(self.nodes),)
+
+class Pass(Node):
+    def __init__(self, lineno=None):
+        self.lineno = lineno
+
+    def getChildren(self):
+        return ()
+
+    def getChildNodes(self):
+        return ()
+
+    def __repr__(self):
+        return "Pass()"
+
+class Power(Node):
+    def __init__(self, leftright, lineno=None):
+        self.left = leftright[0]
+        self.right = leftright[1]
+        self.lineno = lineno
+
+    def getChildren(self):
+        return self.left, self.right
+
+    def getChildNodes(self):
+        return self.left, self.right
+
+    def __repr__(self):
+        return "Power((%s, %s))" % (repr(self.left), repr(self.right))
+
+class Print(Node):
+    def __init__(self, nodes, dest, lineno=None):
+        self.nodes = nodes
+        self.dest = dest
+        self.lineno = lineno
+
+    def getChildren(self):
+        children = []
+        children.extend(flatten(self.nodes))
+        children.append(self.dest)
+        return tuple(children)
+
+    def getChildNodes(self):
+        nodelist = []
+        nodelist.extend(flatten_nodes(self.nodes))
+        if self.dest is not None:
+            nodelist.append(self.dest)
+        return tuple(nodelist)
+
+    def __repr__(self):
+        return "Print(%s, %s)" % (repr(self.nodes), repr(self.dest))
+
+class Printnl(Node):
+    def __init__(self, nodes, dest, lineno=None):
+        self.nodes = nodes
+        self.dest = dest
+        self.lineno = lineno
+
+    def getChildren(self):
+        children = []
+        children.extend(flatten(self.nodes))
+        children.append(self.dest)
+        return tuple(children)
+
+    def getChildNodes(self):
+        nodelist = []
+        nodelist.extend(flatten_nodes(self.nodes))
+        if self.dest is not None:
+            nodelist.append(self.dest)
+        return tuple(nodelist)
+
+    def __repr__(self):
+        return "Printnl(%s, %s)" % (repr(self.nodes), repr(self.dest))
+
+class Raise(Node):
+    def __init__(self, expr1, expr2, expr3, lineno=None):
+        self.expr1 = expr1
+        self.expr2 = expr2
+        self.expr3 = expr3
+        self.lineno = lineno
+
+    def getChildren(self):
+        children = []
+        children.append(self.expr1)
+        children.append(self.expr2)
+        children.append(self.expr3)
+        return tuple(children)
+
+    def getChildNodes(self):
+        nodelist = []
+        if self.expr1 is not None:
+            nodelist.append(self.expr1)
+        if self.expr2 is not None:
+            nodelist.append(self.expr2)
+        if self.expr3 is not None:
+            nodelist.append(self.expr3)
+        return tuple(nodelist)
+
+    def __repr__(self):
+        return "Raise(%s, %s, %s)" % (repr(self.expr1), repr(self.expr2), repr(self.expr3))
+
+class Return(Node):
+    def __init__(self, value, lineno=None):
+        self.value = value
+        self.lineno = lineno
+
+    def getChildren(self):
+        return self.value,
+
+    def getChildNodes(self):
+        return self.value,
+
+    def __repr__(self):
+        return "Return(%s)" % (repr(self.value),)
+
+class RightShift(Node):
+    def __init__(self, leftright, lineno=None):
+        self.left = leftright[0]
+        self.right = leftright[1]
+        self.lineno = lineno
+
+    def getChildren(self):
+        return self.left, self.right
+
+    def getChildNodes(self):
+        return self.left, self.right
+
+    def __repr__(self):
+        return "RightShift((%s, %s))" % (repr(self.left), repr(self.right))
+
+class Slice(Node):
+    def __init__(self, expr, flags, lower, upper, lineno=None):
+        self.expr = expr
+        self.flags = flags
+        self.lower = lower
+        self.upper = upper
+        self.lineno = lineno
+
+    def getChildren(self):
+        children = []
+        children.append(self.expr)
+        children.append(self.flags)
+        children.append(self.lower)
+        children.append(self.upper)
+        return tuple(children)
+
+    def getChildNodes(self):
+        nodelist = []
+        nodelist.append(self.expr)
+        if self.lower is not None:
+            nodelist.append(self.lower)
+        if self.upper is not None:
+            nodelist.append(self.upper)
+        return tuple(nodelist)
+
+    def __repr__(self):
+        return "Slice(%s, %s, %s, %s)" % (repr(self.expr), repr(self.flags), repr(self.lower), repr(self.upper))
+
+class Sliceobj(Node):
+    def __init__(self, nodes, lineno=None):
+        self.nodes = nodes
+        self.lineno = lineno
+
+    def getChildren(self):
+        return tuple(flatten(self.nodes))
+
+    def getChildNodes(self):
+        nodelist = []
+        nodelist.extend(flatten_nodes(self.nodes))
+        return tuple(nodelist)
+
+    def __repr__(self):
+        return "Sliceobj(%s)" % (repr(self.nodes),)
+
+class Stmt(Node):
+    def __init__(self, nodes, lineno=None):
+        self.nodes = nodes
+        self.lineno = lineno
+
+    def getChildren(self):
+        return tuple(flatten(self.nodes))
+
+    def getChildNodes(self):
+        nodelist = []
+        nodelist.extend(flatten_nodes(self.nodes))
+        return tuple(nodelist)
+
+    def __repr__(self):
+        return "Stmt(%s)" % (repr(self.nodes),)
+
+class Sub(Node):
+    def __init__(self, leftright, lineno=None):
+        self.left = leftright[0]
+        self.right = leftright[1]
+        self.lineno = lineno
+
+    def getChildren(self):
+        return self.left, self.right
+
+    def getChildNodes(self):
+        return self.left, self.right
+
+    def __repr__(self):
+        return "Sub((%s, %s))" % (repr(self.left), repr(self.right))
+
+class Subscript(Node):
+    def __init__(self, expr, flags, subs, lineno=None):
+        self.expr = expr
+        self.flags = flags
+        self.subs = subs
+        self.lineno = lineno
+
+    def getChildren(self):
+        children = []
+        children.append(self.expr)
+        children.append(self.flags)
+        children.extend(flatten(self.subs))
+        return tuple(children)
+
+    def getChildNodes(self):
+        nodelist = []
+        nodelist.append(self.expr)
+        nodelist.extend(flatten_nodes(self.subs))
+        return tuple(nodelist)
+
+    def __repr__(self):
+        return "Subscript(%s, %s, %s)" % (repr(self.expr), repr(self.flags), repr(self.subs))
+
+class TryExcept(Node):
+    def __init__(self, body, handlers, else_, lineno=None):
+        self.body = body
+        self.handlers = handlers
+        self.else_ = else_
+        self.lineno = lineno
+
+    def getChildren(self):
+        children = []
+        children.append(self.body)
+        children.extend(flatten(self.handlers))
+        children.append(self.else_)
+        return tuple(children)
+
+    def getChildNodes(self):
+        nodelist = []
+        nodelist.append(self.body)
+        nodelist.extend(flatten_nodes(self.handlers))
+        if self.else_ is not None:
+            nodelist.append(self.else_)
+        return tuple(nodelist)
+
+    def __repr__(self):
+        return "TryExcept(%s, %s, %s)" % (repr(self.body), repr(self.handlers), repr(self.else_))
+
+class TryFinally(Node):
+    def __init__(self, body, final, lineno=None):
+        self.body = body
+        self.final = final
+        self.lineno = lineno
+
+    def getChildren(self):
+        return self.body, self.final
+
+    def getChildNodes(self):
+        return self.body, self.final
+
+    def __repr__(self):
+        return "TryFinally(%s, %s)" % (repr(self.body), repr(self.final))
+
+class Tuple(Node):
+    def __init__(self, nodes, lineno=None):
+        self.nodes = nodes
+        self.lineno = lineno
+
+    def getChildren(self):
+        return tuple(flatten(self.nodes))
+
+    def getChildNodes(self):
+        nodelist = []
+        nodelist.extend(flatten_nodes(self.nodes))
+        return tuple(nodelist)
+
+    def __repr__(self):
+        return "Tuple(%s)" % (repr(self.nodes),)
+
+class UnaryAdd(Node):
+    def __init__(self, expr, lineno=None):
+        self.expr = expr
+        self.lineno = lineno
+
+    def getChildren(self):
+        return self.expr,
+
+    def getChildNodes(self):
+        return self.expr,
+
+    def __repr__(self):
+        return "UnaryAdd(%s)" % (repr(self.expr),)
+
+class UnarySub(Node):
+    def __init__(self, expr, lineno=None):
+        self.expr = expr
+        self.lineno = lineno
+
+    def getChildren(self):
+        return self.expr,
+
+    def getChildNodes(self):
+        return self.expr,
+
+    def __repr__(self):
+        return "UnarySub(%s)" % (repr(self.expr),)
+
+class While(Node):
+    def __init__(self, test, body, else_, lineno=None):
+        self.test = test
+        self.body = body
+        self.else_ = else_
+        self.lineno = lineno
+
+    def getChildren(self):
+        children = []
+        children.append(self.test)
+        children.append(self.body)
+        children.append(self.else_)
+        return tuple(children)
+
+    def getChildNodes(self):
+        nodelist = []
+        nodelist.append(self.test)
+        nodelist.append(self.body)
+        if self.else_ is not None:
+            nodelist.append(self.else_)
+        return tuple(nodelist)
+
+    def __repr__(self):
+        return "While(%s, %s, %s)" % (repr(self.test), repr(self.body), repr(self.else_))
+
+class With(Node):
+    def __init__(self, expr, vars, body, lineno=None):
+        self.expr = expr
+        self.vars = vars
+        self.body = body
+        self.lineno = lineno
+
+    def getChildren(self):
+        children = []
+        children.append(self.expr)
+        children.append(self.vars)
+        children.append(self.body)
+        return tuple(children)
+
+    def getChildNodes(self):
+        nodelist = []
+        nodelist.append(self.expr)
+        if self.vars is not None:
+            nodelist.append(self.vars)
+        nodelist.append(self.body)
+        return tuple(nodelist)
+
+    def __repr__(self):
+        return "With(%s, %s, %s)" % (repr(self.expr), repr(self.vars), repr(self.body))
+
+class Yield(Node):
+    def __init__(self, value, lineno=None):
+        self.value = value
+        self.lineno = lineno
+
+    def getChildren(self):
+        return self.value,
+
+    def getChildNodes(self):
+        return self.value,
+
+    def __repr__(self):
+        return "Yield(%s)" % (repr(self.value),)
+
+for name, obj in globals().items():
+    if isinstance(obj, type) and issubclass(obj, Node):
+        nodes[name.lower()] = obj
diff -r 000000000000 -r 7bec0014e871 compiler/consts.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/compiler/consts.py	Fri May 18 20:51:41 2012 +0200
@@ -0,0 +1,22 @@
+# operation flags
+OP_ASSIGN = 'OP_ASSIGN'
+OP_DELETE = 'OP_DELETE'
+OP_APPLY = 'OP_APPLY'
+
+SC_LOCAL = 1
+SC_GLOBAL = 2
+SC_FREE = 3
+SC_CELL = 4
+SC_UNKNOWN = 5
+
+CO_OPTIMIZED = 0x0001
+CO_NEWLOCALS = 0x0002
+CO_VARARGS = 0x0004
+CO_VARKEYWORDS = 0x0008
+CO_NESTED = 0x0010
+CO_GENERATOR = 0x0020
+CO_GENERATOR_ALLOWED = 0
+CO_FUTURE_DIVISION = 0x2000
+CO_FUTURE_ABSIMPORT = 0x4000
+CO_FUTURE_WITH_STATEMENT = 0x8000
+CO_FUTURE_PRINT_FUNCTION = 0x10000
diff -r 000000000000 -r 7bec0014e871 compiler/future.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/compiler/future.py	Fri May 18 20:51:41 2012 +0200
@@ -0,0 +1,74 @@
+"""Parser for future statements
+
+"""
+
+from compiler import ast, walk
+
+def is_future(stmt):
+    """Return true if statement is a well-formed future statement"""
+    if not isinstance(stmt, ast.From):
+        return 0
+    if stmt.modname == "__future__":
+        return 1
+    else:
+        return 0
+
+class FutureParser:
+
+    features = ("nested_scopes", "generators", "division",
+                "absolute_import", "with_statement", "print_function",
+                "unicode_literals")
+
+    def __init__(self):
+        self.found = {} # set
+
+    def visitModule(self, node):
+        stmt = node.node
+        for s in stmt.nodes:
+            if not self.check_stmt(s):
+                break
+
+    def check_stmt(self, stmt):
+        if is_future(stmt):
+            for name, asname in stmt.names:
+                if name in self.features:
+                    self.found[name] = 1
+                else:
+                    raise SyntaxError, \
+                          "future feature %s is not defined" % name
+            stmt.valid_future = 1
+            return 1
+        return 0
+
+    def get_features(self):
+        """Return list of features enabled by future statements"""
+        return self.found.keys()
+
+class BadFutureParser:
+    """Check for invalid future statements"""
+
+    def visitFrom(self, node):
+        if hasattr(node, 'valid_future'):
+            return
+        if node.modname != "__future__":
+            return
+        raise SyntaxError, "invalid future statement " + repr(node)
+
+def find_futures(node):
+    p1 = FutureParser()
+    p2 = BadFutureParser()
+    walk(node, p1)
+    walk(node, p2)
+    return p1.get_features()
+
+if __name__ == "__main__":
+    import sys
+    from compiler import parseFile, walk
+
+    for file in sys.argv[1:]:
+        print file
+        tree = parseFile(file)
+        v = FutureParser()
+        walk(tree, v)
+        print v.found
+        print
diff -r 000000000000 -r 7bec0014e871 compiler/misc.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/compiler/misc.py	Fri May 18 20:51:41 2012 +0200
@@ -0,0 +1,73 @@
+
+def flatten(tup):
+    elts = []
+    for elt in tup:
+        if isinstance(elt, tuple):
+            elts = elts + flatten(elt)
+        else:
+            elts.append(elt)
+    return elts
+
+class Set:
+    def __init__(self):
+        self.elts = {}
+    def __len__(self):
+        return len(self.elts)
+    def __contains__(self, elt):
+        return elt in self.elts
+    def add(self, elt):
+        self.elts[elt] = elt
+    def elements(self):
+        return self.elts.keys()
+    def has_elt(self, elt):
+        return elt in self.elts
+    def remove(self, elt):
+        del self.elts[elt]
+    def copy(self):
+        c = Set()
+        c.elts.update(self.elts)
+        return c
+
+class Stack:
+    def __init__(self):
+        self.stack = []
+        self.pop = self.stack.pop
+    def __len__(self):
+        return len(self.stack)
+    def push(self, elt):
+        self.stack.append(elt)
+    def top(self):
+        return self.stack[-1]
+    def __getitem__(self, index): # needed by visitContinue()
+        return self.stack[index]
+
+MANGLE_LEN = 256 # magic constant from compile.c
+
+def mangle(name, klass):
+    if not name.startswith('__'):
+        return name
+    if len(name) + 2 >= MANGLE_LEN:
+        return name
+    if name.endswith('__'):
+        return name
+    try:
+        i = 0
+        while klass[i] == '_':
+            i = i + 1
+    except IndexError:
+        return name
+    klass = klass[i:]
+
+    tlen = len(klass) + len(name)
+    if tlen > MANGLE_LEN:
+        klass = klass[:MANGLE_LEN-tlen]
+
+    return "_%s%s" % (klass, name)
+
+def set_filename(filename, tree):
+    """Set the filename attribute to filename on every node in tree"""
+    worklist = [tree]
+    while worklist:
+        node = worklist.pop(0)
+        node.filename = filename
+        worklist.extend(node.getChildNodes())
diff -r 000000000000 -r 7bec0014e871 compiler/pyassem.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/compiler/pyassem.py	Fri May 18 20:51:41 2012 +0200
@@ -0,0 +1,818 @@
+"""A flow graph representation for Python bytecode"""
+
+import dis
+import types
+import sys
+
+from compiler import misc
+from compiler.consts \
+     import CO_OPTIMIZED, CO_NEWLOCALS, CO_VARARGS, CO_VARKEYWORDS
+
+class FlowGraph:
+    def __init__(self):
+        self.current = self.entry = Block()
+        self.exit = Block("exit")
+        self.blocks = misc.Set()
+        self.blocks.add(self.entry)
+        self.blocks.add(self.exit)
+
+    def startBlock(self, block):
+        if self._debug:
+            if self.current:
+                print "end", repr(self.current)
+                print "    next", self.current.next
+                print "   ", self.current.get_children()
+            print repr(block)
+        self.current = block
+
+    def nextBlock(self, block=None):
+        # XXX think we need to specify when there is implicit transfer
+        # from one block to the next.  might be better to represent this
+        # with explicit JUMP_ABSOLUTE instructions that are optimized
+        # out when they are unnecessary.
+        #
+        # I think this strategy works: each block has a child
+        # designated as "next" which is returned as the last of the
+        # children.  because the nodes in a graph are emitted in
+        # reverse post order, the "next" block will always be emitted
+        # immediately after its parent.
+        # Worry: maintaining this invariant could be tricky
+        if block is None:
+            block = self.newBlock()
+
+        # Note: If the current block ends with an unconditional
+        # control transfer, then it is incorrect to add an implicit
+        # transfer to the block graph.  The current code requires
+        # these edges to get the blocks emitted in the right order,
+        # however. :-(  If a client needs to remove these edges, call
+        # pruneEdges().
+
+        self.current.addNext(block)
+        self.startBlock(block)
+
+    def newBlock(self):
+        b = Block()
+        self.blocks.add(b)
+        return b
+
+    def startExitBlock(self):
+        self.startBlock(self.exit)
+
+    _debug = 0
+
+    def _enable_debug(self):
+        self._debug = 1
+
+    def _disable_debug(self):
+        self._debug = 0
+
+    def emit(self, *inst):
+        if self._debug:
+            print "\t", inst
+        if inst[0] in ['RETURN_VALUE', 'YIELD_VALUE']:
+            self.current.addOutEdge(self.exit)
+        if len(inst) == 2 and isinstance(inst[1], Block):
+            self.current.addOutEdge(inst[1])
+        self.current.emit(inst)
+
+    def getBlocksInOrder(self):
+        """Return the blocks in reverse postorder
+
+        i.e. each node appears before all of its successors
+        """
+        # XXX make sure every node that doesn't have an explicit next
+        # is set so that next points to exit
+        for b in self.blocks.elements():
+            if b is self.exit:
+                continue
+            if not b.next:
+                b.addNext(self.exit)
+        order = dfs_postorder(self.entry, {})
+        order.reverse()
+        self.fixupOrder(order, self.exit)
+        # hack alert
+        if not self.exit in order:
+            order.append(self.exit)
+
+        return order
+
+    def fixupOrder(self, blocks, default_next):
+        """Fixup bad order introduced by DFS."""
+
+        # XXX This is a total mess.  There must be a better way to get
+        # the code blocks in the right order.
+
+        self.fixupOrderHonorNext(blocks, default_next)
+        self.fixupOrderForward(blocks, default_next)
+
+    def fixupOrderHonorNext(self, blocks, default_next):
+        """Fix one problem with DFS.
+
+        The DFS uses child block, but doesn't know about the special
+        "next" block.  As a result, the DFS can order blocks so that a
+        block isn't next to the right block for implicit control
+        transfers.
+        """
+        index = {}
+        for i in range(len(blocks)):
+            index[blocks[i]] = i
+
+        for i in range(0, len(blocks) - 1):
+            b = blocks[i]
+            n = blocks[i + 1]
+            if not b.next or b.next[0] == default_next or b.next[0] == n:
+                continue
+            # The blocks are in the wrong order.  Find the chain of
+            # blocks to insert where they belong.
+            cur = b
+            chain = []
+            elt = cur
+            while elt.next and elt.next[0] != default_next:
+                chain.append(elt.next[0])
+                elt = elt.next[0]
+            # Now remove the blocks in the chain from the current
+            # block list, so that they can be re-inserted.
+            l = []
+            for b in chain:
+                assert index[b] > i
+                l.append((index[b], b))
+            l.sort()
+            l.reverse()
+            for j, b in l:
+                del blocks[index[b]]
+            # Insert the chain in the proper location
+            blocks[i:i + 1] = [cur] + chain
+            # Finally, re-compute the block indexes
+            for i in range(len(blocks)):
+                index[blocks[i]] = i
+
+    def fixupOrderForward(self, blocks, default_next):
+        """Make sure all JUMP_FORWARDs jump forward"""
+        index = {}
+        chains = []
+        cur = []
+        for b in blocks:
+            index[b] = len(chains)
+            cur.append(b)
+            if b.next and b.next[0] == default_next:
+                chains.append(cur)
+                cur = []
+        chains.append(cur)
+
+        while 1:
+            constraints = []
+
+            for i in range(len(chains)):
+                l = chains[i]
+                for b in l:
+                    for c in b.get_children():
+                        if index[c] < i:
+                            forward_p = 0
+                            for inst in b.insts:
+                                if inst[0] == 'JUMP_FORWARD':
+                                    if inst[1] == c:
+                                        forward_p = 1
+                            if not forward_p:
+                                continue
+                            constraints.append((index[c], i))
+
+            if not constraints:
+                break
+
+            # XXX just do one for now
+            # do swaps to get things in the right order
+            goes_before, a_chain = constraints[0]
+            assert a_chain > goes_before
+            c = chains[a_chain]
+            chains.remove(c)
+            chains.insert(goes_before, c)
+
+        del blocks[:]
+        for c in chains:
+            for b in c:
+                blocks.append(b)
+
+    def getBlocks(self):
+        return self.blocks.elements()
+
+    def getRoot(self):
+        """Return nodes appropriate for use with dominator"""
+        return self.entry
+
+    def getContainedGraphs(self):
+        l = []
+        for b in self.getBlocks():
+            l.extend(b.getContainedGraphs())
+        return l
+
+def dfs_postorder(b, seen):
+    """Depth-first search of tree rooted at b, return in postorder"""
+    order = []
+    seen[b] = b
+    for c in b.get_children():
+        if c in seen:
+            continue
+        order = order + dfs_postorder(c, seen)
+    order.append(b)
+    return order
+
+class Block:
+    _count = 0
+
+    def __init__(self, label=''):
+        self.insts = []
+        self.inEdges = misc.Set()
+        self.outEdges = misc.Set()
+        self.label = label
+        self.bid = Block._count
+        self.next = []
+        Block._count = Block._count + 1
+
+    def __repr__(self):
+        if self.label:
+            return "<block %s id=%d>" % (self.label, self.bid)
+        else:
+            return "<block id=%d>" % (self.bid)
+
+    def __str__(self):
+        insts = map(str, self.insts)
+        return "<block %s %d:\n%s>" % (self.label, self.bid,
+                                       '\n'.join(insts))
+
+    def emit(self, inst):
+        op = inst[0]
+        if op[:4] == 'JUMP':
+            self.outEdges.add(inst[1])
+        self.insts.append(inst)
+
+    def getInstructions(self):
+        return self.insts
+
+    def addInEdge(self, block):
+        self.inEdges.add(block)
+
+    def addOutEdge(self, block):
+        self.outEdges.add(block)
+
+    def addNext(self, block):
+        self.next.append(block)
+        assert len(self.next) == 1, map(str, self.next)
+
+    _uncond_transfer = ('RETURN_VALUE', 'RAISE_VARARGS', 'YIELD_VALUE',
+                        'JUMP_ABSOLUTE', 'JUMP_FORWARD', 'CONTINUE_LOOP')
+
+    def pruneNext(self):
+        """Remove bogus edge for unconditional transfers
+
+        Each block has a next edge that accounts for implicit control
+        transfers, e.g. from a JUMP_IF_FALSE to the block that will be
+        executed if the test is true.
+
+        These edges must remain for the current assembler code to
+        work. If they are removed, the dfs_postorder gets things in
+        weird orders.  However, they shouldn't be there for other
+        purposes, e.g. conversion to SSA form.  This method will
+        remove the next edge when it follows an unconditional control
+        transfer.
+        """
+        try:
+            op, arg = self.insts[-1]
+        except (IndexError, ValueError):
+            return
+        if op in self._uncond_transfer:
+            self.next = []
+
+    def get_children(self):
+        if self.next and self.next[0] in self.outEdges:
+            self.outEdges.remove(self.next[0])
+        return self.outEdges.elements() + self.next
+
+    def getContainedGraphs(self):
+        """Return all graphs contained within this block.
+
+        For example, a MAKE_FUNCTION block will contain a reference to
+        the graph for the function body.
+        """
+        contained = []
+        for inst in self.insts:
+            if len(inst) == 1:
+                continue
+            op = inst[1]
+            if hasattr(op, 'graph'):
+                contained.append(op.graph)
+        return contained
+
+# flags for code objects
+
+# the FlowGraph is transformed in place; it exists in one of these states
+RAW = "RAW"
+FLAT = "FLAT"
+CONV = "CONV"
+DONE = "DONE"
+
+class PyFlowGraph(FlowGraph):
+    super_init = FlowGraph.__init__
+
+    def __init__(self, name, filename, args=(), optimized=0, klass=None):
+        self.super_init()
+        self.name = name
+        self.filename = filename
+        self.docstring = None
+        self.args = args # XXX
+        self.argcount = getArgCount(args)
+        self.klass = klass
+        if optimized:
+            self.flags = CO_OPTIMIZED | CO_NEWLOCALS
+        else:
+            self.flags = 0
+        self.consts = []
+        self.names = []
+        # Free variables found by the symbol table scan, including
+        # variables used only in nested scopes, are included here.
+        self.freevars = []
+        self.cellvars = []
+        # The closure list is used to track the order of cell
+        # variables and free variables in the resulting code object.
+        # The offsets used by LOAD_CLOSURE/LOAD_DEREF refer to both
+        # kinds of variables.
+        self.closure = []
+        self.varnames = list(args) or []
+        for i in range(len(self.varnames)):
+            var = self.varnames[i]
+            if isinstance(var, TupleArg):
+                self.varnames[i] = var.getName()
+        self.stage = RAW
+
+    def setDocstring(self, doc):
+        self.docstring = doc
+
+    def setFlag(self, flag):
+        self.flags = self.flags | flag
+        if flag == CO_VARARGS:
+            self.argcount = self.argcount - 1
+
+    def checkFlag(self, flag):
+        if self.flags & flag:
+            return 1
+
+    def setFreeVars(self, names):
+        self.freevars = list(names)
+
+    def setCellVars(self, names):
+        self.cellvars = names
+
+    def getCode(self):
+        """Get a Python code object"""
+        assert self.stage == RAW
+        self.computeStackDepth()
+        self.flattenGraph()
+        assert self.stage == FLAT
+        self.convertArgs()
+        assert self.stage == CONV
+        self.makeByteCode()
+        assert self.stage == DONE
+        return self.newCodeObject()
+
+    def dump(self, io=None):
+        if io:
+            save = sys.stdout
+            sys.stdout = io
+        pc = 0
+        for t in self.insts:
+            opname = t[0]
+            if opname == "SET_LINENO":
+                print
+            if len(t) == 1:
+                print "\t", "%3d" % pc, opname
+                pc = pc + 1
+            else:
+                print "\t", "%3d" % pc, opname, t[1]
+                pc = pc + 3
+        if io:
+            sys.stdout = save
+
+    def computeStackDepth(self):
+        """Compute the max stack depth.
+
+        Approach is to compute the stack effect of each basic block.
+        Then find the path through the code with the largest total
+        effect.
+        """
+        depth = {}
+        exit = None
+        for b in self.getBlocks():
+            depth[b] = findDepth(b.getInstructions())
+
+        seen = {}
+
+        def max_depth(b, d):
+            if b in seen:
+                return d
+            seen[b] = 1
+            d = d + depth[b]
+            children = b.get_children()
+            if children:
+                return max([max_depth(c, d) for c in children])
+            else:
+                if not b.label == "exit":
+                    return max_depth(self.exit, d)
+                else:
+                    return d
+
+        self.stacksize = max_depth(self.entry, 0)
+
+    def flattenGraph(self):
+        """Arrange the blocks in order and resolve jumps"""
+        assert self.stage == RAW
+        self.insts = insts = []
+        pc = 0
+        begin = {}
+        end = {}
+        for b in self.getBlocksInOrder():
+            begin[b] = pc
+            for inst in b.getInstructions():
+                insts.append(inst)
+                if len(inst) == 1:
+                    pc = pc + 1
+                elif inst[0] != "SET_LINENO":
+                    # arg takes 2 bytes
+                    pc = pc + 3
+            end[b] = pc
+        pc = 0
+        for i in range(len(insts)):
+            inst = insts[i]
+            if len(inst) == 1:
+                pc = pc + 1
+            elif inst[0] != "SET_LINENO":
+                pc = pc + 3
+            opname = inst[0]
+            if self.hasjrel.has_elt(opname):
+                oparg = inst[1]
+                offset = begin[oparg] - pc
+                insts[i] = opname, offset
+            elif self.hasjabs.has_elt(opname):
+                insts[i] = opname, begin[inst[1]]
+        self.stage = FLAT
+
+    hasjrel = misc.Set()
+    for i in dis.hasjrel:
+        hasjrel.add(dis.opname[i])
+    hasjabs = misc.Set()
+    for i in dis.hasjabs:
+        hasjabs.add(dis.opname[i])
+
+    def convertArgs(self):
+        """Convert arguments from symbolic to concrete form"""
+        assert self.stage == FLAT
+        self.consts.insert(0, self.docstring)
+        self.sort_cellvars()
+        for i in range(len(self.insts)):
+            t = self.insts[i]
+            if len(t) == 2:
+                opname, oparg = t
+                conv = self._converters.get(opname, None)
+                if conv:
+                    self.insts[i] = opname, conv(self, oparg)
+        self.stage = CONV
+
+    def sort_cellvars(self):
+        """Sort cellvars in the order of varnames and prune from freevars.
+        """
+        cells = {}
+        for name in self.cellvars:
+            cells[name] = 1
+        self.cellvars = [name for name in self.varnames
+                         if name in cells]
+        for name in self.cellvars:
+            del cells[name]
+        self.cellvars = self.cellvars + cells.keys()
+        self.closure = self.cellvars + self.freevars
+
+    def _lookupName(self, name, list):
+        """Return index of name in list, appending if necessary
+
+        This routine uses a list instead of a dictionary, because a
+        dictionary can't store two different keys if the keys have the
+        same value but different types, e.g. 2 and 2L.  The compiler
+        must treat these two separately, so it does an explicit type
+        comparison before comparing the values.
+        """
+        t = type(name)
+        for i in range(len(list)):
+            if t == type(list[i]) and list[i] == name:
+                return i
+        end = len(list)
+        list.append(name)
+        return end
+
+    _converters = {}
+    def _convert_LOAD_CONST(self, arg):
+        if hasattr(arg, 'getCode'):
+            arg = arg.getCode()
+        return self._lookupName(arg, self.consts)
+
+    def _convert_LOAD_FAST(self, arg):
+        self._lookupName(arg, self.names)
+        return self._lookupName(arg, self.varnames)
+    _convert_STORE_FAST = _convert_LOAD_FAST
+    _convert_DELETE_FAST = _convert_LOAD_FAST
+
+    def _convert_LOAD_NAME(self, arg):
+        if self.klass is None:
+            self._lookupName(arg, self.varnames)
+        return self._lookupName(arg, self.names)
+
+    def _convert_NAME(self, arg):
+        if self.klass is None:
+            self._lookupName(arg, self.varnames)
+        return self._lookupName(arg, self.names)
+    _convert_STORE_NAME = _convert_NAME
+    _convert_DELETE_NAME = _convert_NAME
+    _convert_IMPORT_NAME = _convert_NAME
+    _convert_IMPORT_FROM = _convert_NAME
+    _convert_STORE_ATTR = _convert_NAME
+    _convert_LOAD_ATTR = _convert_NAME
+    _convert_DELETE_ATTR = _convert_NAME
+    _convert_LOAD_GLOBAL = _convert_NAME
+    _convert_STORE_GLOBAL = _convert_NAME
+    _convert_DELETE_GLOBAL = _convert_NAME
+
+    def _convert_DEREF(self, arg):
+        self._lookupName(arg, self.names)
+        self._lookupName(arg, self.varnames)
+        return self._lookupName(arg, self.closure)
+    _convert_LOAD_DEREF = _convert_DEREF
+    _convert_STORE_DEREF = _convert_DEREF
+
+    def _convert_LOAD_CLOSURE(self, arg):
+        self._lookupName(arg, self.varnames)
+        return self._lookupName(arg, self.closure)
+
+    _cmp = list(dis.cmp_op)
+    def _convert_COMPARE_OP(self, arg):
+        return self._cmp.index(arg)
+
+    # similarly for other opcodes...
+
+    for name, obj in locals().items():
+        if name[:9] == "_convert_":
+            opname = name[9:]
+            _converters[opname] = obj
+    del name, obj, opname
+
+    def makeByteCode(self):
+        assert self.stage == CONV
+        self.lnotab = lnotab = LineAddrTable()
+        for t in self.insts:
+            opname = t[0]
+            if len(t) == 1:
+                lnotab.addCode(self.opnum[opname])
+            else:
+                oparg = t[1]
+                if opname == "SET_LINENO":
+                    lnotab.nextLine(oparg)
+                    continue
+                hi, lo = twobyte(oparg)
+                try:
+                    lnotab.addCode(self.opnum[opname], lo, hi)
+                except ValueError:
+                    print opname, oparg
+                    print self.opnum[opname], lo, hi
+                    raise
+        self.stage = DONE
+
+    opnum = {}
+    for num in range(len(dis.opname)):
+        opnum[dis.opname[num]] = num
+    del num
+
+    def newCodeObject(self):
+        assert self.stage == DONE
+        if (self.flags & CO_NEWLOCALS) == 0:
+            nlocals = 0
+        else:
+            nlocals = len(self.varnames)
+        argcount = self.argcount
+        if self.flags & CO_VARKEYWORDS:
+            argcount = argcount - 1
+        return types.CodeType(argcount, nlocals, self.stacksize, self.flags,
+                        self.lnotab.getCode(), self.getConsts(),
+                        tuple(self.names), tuple(self.varnames),
+                        self.filename, self.name, self.lnotab.firstline,
+                        self.lnotab.getTable(), tuple(self.freevars),
+                        tuple(self.cellvars))
+
+    def getConsts(self):
+        """Return a tuple for the const slot of the code object
+
+        Must convert references to code (MAKE_FUNCTION) to code
+        objects recursively.
+        """
+        l = []
+        for elt in self.consts:
+            if isinstance(elt, PyFlowGraph):
+                elt = elt.getCode()
+            l.append(elt)
+        return tuple(l)
+
+def isJump(opname):
+    if opname[:4] == 'JUMP':
+        return 1
+
+class TupleArg:
+    """Helper for marking func defs with nested tuples in arglist"""
+    def __init__(self, count, names):
+        self.count = count
+        self.names = names
+    def __repr__(self):
+        return "TupleArg(%s, %s)" % (self.count, self.names)
+    def getName(self):
+        return ".%d" % self.count
+
+def getArgCount(args):
+    argcount = len(args)
+    if args:
+        for arg in args:
+            if isinstance(arg, TupleArg):
+                numNames = len(misc.flatten(arg.names))
+                argcount = argcount - numNames
+    return argcount
+
+def twobyte(val):
+    """Convert an int argument into high and low bytes"""
+    assert isinstance(val, int)
+    return divmod(val, 256)
+
+class LineAddrTable:
+    """lnotab
+
+    This class builds the lnotab, which is documented in compile.c.
+    Here's a brief recap:
+
+    For each SET_LINENO instruction after the first one, two bytes are
+    added to lnotab.  (In some cases, multiple two-byte entries are
+    added.)  The first byte is the distance in bytes between the
+    instruction for the last SET_LINENO and the current SET_LINENO.
+    The second byte is offset in line numbers.  If either offset is
+    greater than 255, multiple two-byte entries are added -- see
+    compile.c for the delicate details.
+    """
+
+    def __init__(self):
+        self.code = []
+        self.codeOffset = 0
+        self.firstline = 0
+        self.lastline = 0
+        self.lastoff = 0
+        self.lnotab = []
+
+    def addCode(self, *args):
+        for arg in args:
+            self.code.append(chr(arg))
+        self.codeOffset = self.codeOffset + len(args)
+
+    def nextLine(self, lineno):
+        if self.firstline == 0:
+            self.firstline = lineno
+            self.lastline = lineno
+        else:
+            # compute deltas
+            addr = self.codeOffset - self.lastoff
+            line = lineno - self.lastline
+            # Python assumes that lineno always increases with
+            # increasing bytecode address (lnotab is unsigned char).
+            # Depending on when SET_LINENO instructions are emitted
+            # this is not always true.  Consider the code:
+            #     a = (1,
+            #          b)
+            # In the bytecode stream, the assignment to "a" occurs
+            # after the loading of "b".  This works with the C Python
+            # compiler because it only generates a SET_LINENO instruction
+            # for the assignment.
+            if line >= 0:
+                push = self.lnotab.append
+                while addr > 255:
+                    push(255); push(0)
+                    addr -= 255
+                while line > 255:
+                    push(addr); push(255)
+                    line -= 255
+                    addr = 0
+                if addr > 0 or line > 0:
+                    push(addr); push(line)
+                self.lastline = lineno
+                self.lastoff = self.codeOffset
+
+    def getCode(self):
+        return ''.join(self.code)
+
+    def getTable(self):
+        return ''.join(map(chr, self.lnotab))
+
+class StackDepthTracker:
+    # XXX 1. need to keep track of stack depth on jumps
+    # XXX 2. at least partly as a result, this code is broken
+
+    def findDepth(self, insts, debug=0):
+        depth = 0
+        maxDepth = 0
+        for i in insts:
+            opname = i[0]
+            if debug:
+                print i,
+            delta = self.effect.get(opname, None)
+            if delta is not None:
+                depth = depth + delta
+            else:
+                # now check patterns
+                for pat, pat_delta in self.patterns:
+                    if opname[:len(pat)] == pat:
+                        delta = pat_delta
+                        depth = depth + delta
+                        break
+                # if we still haven't found a match
+                if delta is None:
+                    meth = getattr(self, opname, None)
+                    if meth is not None:
+                        depth = depth + meth(i[1])
+            if depth > maxDepth:
+                maxDepth = depth
+            if debug:
+                print depth, maxDepth
+        return maxDepth
+
+    effect = {
+        'POP_TOP': -1,
+        'DUP_TOP': 1,
+        'LIST_APPEND': -2,
+        'SLICE+1': -1,
+        'SLICE+2': -1,
+        'SLICE+3': -2,
+        'STORE_SLICE+0': -1,
+        'STORE_SLICE+1': -2,
+        'STORE_SLICE+2': -2,
+        'STORE_SLICE+3': -3,
+        'DELETE_SLICE+0': -1,
+        'DELETE_SLICE+1': -2,
+        'DELETE_SLICE+2': -2,
+        'DELETE_SLICE+3': -3,
+        'STORE_SUBSCR': -3,
+        'DELETE_SUBSCR': -2,
+        # PRINT_EXPR?
+        'PRINT_ITEM': -1,
+        'RETURN_VALUE': -1,
+        'YIELD_VALUE': -1,
+        'EXEC_STMT': -3,
+        'BUILD_CLASS': -2,
+        'STORE_NAME': -1,
+        'STORE_ATTR': -2,
+        'DELETE_ATTR': -1,
+        'STORE_GLOBAL': -1,
+        'BUILD_MAP': 1,
+        'COMPARE_OP': -1,
+        'STORE_FAST': -1,
+        'IMPORT_STAR': -1,
+        'IMPORT_NAME': -1,
+        'IMPORT_FROM': 1,
+        'LOAD_ATTR': 0, # unlike other loads
+        # close enough...
+        'SETUP_EXCEPT': 3,
+        'SETUP_FINALLY': 3,
+        'FOR_ITER': 1,
+        'WITH_CLEANUP': -1,
+        }
+    # use pattern match
+    patterns = [
+        ('BINARY_', -1),
+        ('LOAD_', 1),
+        ]
+
+    def UNPACK_SEQUENCE(self, count):
+        return count-1
+    def BUILD_TUPLE(self, count):
+        return -count+1
+    def BUILD_LIST(self, count):
+        return -count+1
+    def CALL_FUNCTION(self, argc):
+        hi, lo = divmod(argc, 256)
+        return -(lo + hi * 2)
+    def CALL_FUNCTION_VAR(self, argc):
+        return self.CALL_FUNCTION(argc)-1
+    def CALL_FUNCTION_KW(self, argc):
+        return self.CALL_FUNCTION(argc)-1
+    def CALL_FUNCTION_VAR_KW(self, argc):
+        return self.CALL_FUNCTION(argc)-2
+    def MAKE_FUNCTION(self, argc):
+        return -argc
+    def MAKE_CLOSURE(self, argc):
+        # XXX need to account for free variables too!
+        return -argc
+    def BUILD_SLICE(self, argc):
+        if argc == 2:
+            return -1
+        elif argc == 3:
+            return -2
+    def DUP_TOPX(self, argc):
+        return argc
+
+findDepth = StackDepthTracker().findDepth
diff -r 000000000000 -r 7bec0014e871 compiler/pycodegen.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/compiler/pycodegen.py	Fri May 18 20:51:41 2012 +0200
@@ -0,0 +1,1530 @@
+import imp
+import os
+import marshal
+import struct
+import sys
+from cStringIO import StringIO
+
+from compiler import ast, parse, walk, syntax
+from compiler import pyassem, misc, future, symbols
+from compiler.consts import SC_LOCAL, SC_GLOBAL, SC_FREE, SC_CELL
+from compiler.consts import (CO_VARARGS, CO_VARKEYWORDS, CO_NEWLOCALS,
+     CO_NESTED, CO_GENERATOR, CO_FUTURE_DIVISION,
+     CO_FUTURE_ABSIMPORT, CO_FUTURE_WITH_STATEMENT, CO_FUTURE_PRINT_FUNCTION)
+from compiler.pyassem import TupleArg
+
+# XXX The version-specific code can go, since this code only works with 2.x.
+# Do we have Python 1.x or Python 2.x?
+try:
+    VERSION = sys.version_info[0]
+except AttributeError:
+    VERSION = 1
+
+callfunc_opcode_info = {
+    # (Have *args, Have **args) : opcode
+    (0,0) : "CALL_FUNCTION",
+    (1,0) : "CALL_FUNCTION_VAR",
+    (0,1) : "CALL_FUNCTION_KW",
+    (1,1) : "CALL_FUNCTION_VAR_KW",
+}
+
+LOOP = 1
+EXCEPT = 2
+TRY_FINALLY = 3
+END_FINALLY = 4
+
+def compileFile(filename, display=0):
+    f = open(filename, 'U')
+    buf = f.read()
+    f.close()
+    mod = Module(buf, filename)
+    try:
+        mod.compile(display)
+    except SyntaxError:
+        raise
+    else:
+        f = open(filename + "c", "wb")
+        mod.dump(f)
+        f.close()
+
+def compile(source, filename, mode, flags=None, dont_inherit=None):
+    """Replacement for builtin compile() function"""
+    if flags is not None or dont_inherit is not None:
+        raise RuntimeError, "not implemented yet"
+
+    if mode == "single":
+        gen = Interactive(source, filename)
+    elif mode == "exec":
+        gen = Module(source, filename)
+    elif mode == "eval":
+        gen = Expression(source, filename)
+    else:
+        raise ValueError("compile() 3rd arg must be 'exec' or "
+                         "'eval' or 'single'")
+    gen.compile()
+    return gen.code
+
+class AbstractCompileMode:
+
+    mode = None # defined by subclass
+
+    def __init__(self, source, filename):
+        self.source = source
+        self.filename = filename
+        self.code = None
+
+    def _get_tree(self):
+        tree = parse(self.source, self.mode)
+        misc.set_filename(self.filename, tree)
+        syntax.check(tree)
+        return tree
+
+    def compile(self):
+        pass # implemented by subclass
+
+    def getCode(self):
+        return self.code
+
+class Expression(AbstractCompileMode):
+
+    mode = "eval"
+
+    def compile(self):
+        tree = self._get_tree()
+        gen = ExpressionCodeGenerator(tree)
+        self.code = gen.getCode()
+
+class Interactive(AbstractCompileMode):
+
+    mode = "single"
+
+    def compile(self):
+        tree = self._get_tree()
+        gen = InteractiveCodeGenerator(tree)
+        self.code = gen.getCode()
+
+class Module(AbstractCompileMode):
+
+    mode = "exec"
+
+    def compile(self, display=0):
+        tree = self._get_tree()
+        gen = ModuleCodeGenerator(tree)
+        if display:
+            import pprint
+            print pprint.pprint(tree)
+        self.code = gen.getCode()
+
+    def dump(self, f):
+        f.write(self.getPycHeader())
+        marshal.dump(self.code, f)
+
+    MAGIC = imp.get_magic()
+
+    def getPycHeader(self):
+        # compile.c uses marshal to write a long directly, with
+        # calling the interface that would also generate a 1-byte code
+        # to indicate the type of the value.  simplest way to get the
+        # same effect is to call marshal and then skip the code.
+        mtime = os.path.getmtime(self.filename)
+        mtime = struct.pack('<i', mtime)
+        return self.MAGIC + mtime
+
+class LocalNameFinder:
+    """Find local names in scope"""
+    def __init__(self, names=()):
+        self.names = misc.Set()
+        self.globals = misc.Set()
+        for name in names:
+            self.names.add(name)
+
+    # XXX list comprehensions and for loops
+
+    def getLocals(self):
+        for elt in self.globals.elements():
+            if self.names.has_elt(elt):
+                self.names.remove(elt)
+        return self.names
+
+    def visitDict(self, node):
+        pass
+
+    def visitGlobal(self, node):
+        for name in node.names:
+            self.globals.add(name)
+
+    def visitFunction(self, node):
+        self.names.add(node.name)
+
+    def visitLambda(self, node):
+        pass
+
+    def visitImport(self, node):
+        for name, alias in node.names:
+            self.names.add(alias or name)
+
+    def visitFrom(self, node):
+        for name, alias in node.names:
+            self.names.add(alias or name)
+
+    def visitClass(self, node):
+        self.names.add(node.name)
+
+    def visitAssName(self, node):
+        self.names.add(node.name)
+
+def is_constant_false(node):
+    if isinstance(node, ast.Const):
+        if not node.value:
+            return 1
+    return 0
+
+class CodeGenerator:
+    """Defines basic code generator for Python bytecode
+
+    This class is an abstract base class.  Concrete subclasses must
+    define an __init__() that defines self.graph and then calls the
+    __init__() defined in this class.
+
+    The concrete class must also define the class attributes
+    NameFinder, FunctionGen, and ClassGen.  These attributes can be
+    defined in the initClass() method, which is a hook for
+    initializing these methods after all the classes have been
+    defined.
+    """
+
+    optimized = 0 # is namespace access optimized?
+    __initialized = None
+    class_name = None # provide default for instance variable
+
+    def __init__(self):
+        if self.__initialized is None:
+            self.initClass()
+            self.__class__.__initialized = 1
+        self.checkClass()
+        self.locals = misc.Stack()
+        self.setups = misc.Stack()
+        self.last_lineno = None
+        self._setupGraphDelegation()
+        self._div_op = "BINARY_DIVIDE"
+
+        # XXX set flags based on future features
+        futures = self.get_module().futures
+        for feature in futures:
+            if feature == "division":
+                self.graph.setFlag(CO_FUTURE_DIVISION)
+                self._div_op = "BINARY_TRUE_DIVIDE"
+            elif feature == "absolute_import":
+                self.graph.setFlag(CO_FUTURE_ABSIMPORT)
+            elif feature == "with_statement":
+                self.graph.setFlag(CO_FUTURE_WITH_STATEMENT)
+            elif feature == "print_function":
+                self.graph.setFlag(CO_FUTURE_PRINT_FUNCTION)
+
+    def initClass(self):
+        """This method is called once for each class"""
+
+    def checkClass(self):
+        """Verify that class is constructed correctly"""
+        try:
+            assert hasattr(self, 'graph')
+            assert getattr(self, 'NameFinder')
+            assert getattr(self, 'FunctionGen')
+            assert getattr(self, 'ClassGen')
+        except AssertionError, msg:
+            intro = "Bad class construction for %s" % self.__class__.__name__
+            raise AssertionError, intro
+
+    def _setupGraphDelegation(self):
+        self.emit = self.graph.emit
+        self.newBlock = self.graph.newBlock
+        self.startBlock = self.graph.startBlock
+        self.nextBlock = self.graph.nextBlock
+        self.setDocstring = self.graph.setDocstring
+
+    def getCode(self):
+        """Return a code object"""
+        return self.graph.getCode()
+
+    def mangle(self, name):
+        if self.class_name is not None:
+            return misc.mangle(name, self.class_name)
+        else:
+            return name
+
+    def parseSymbols(self, tree):
+        s = symbols.SymbolVisitor()
+        walk(tree, s)
+        return s.scopes
+
+    def get_module(self):
+        raise RuntimeError, "should be implemented by subclasses"
+
+    # Next five methods handle name access
+
+    def isLocalName(self, name):
+        return self.locals.top().has_elt(name)
+
+    def storeName(self, name):
+        self._nameOp('STORE', name)
+
+    def loadName(self, name):
+        self._nameOp('LOAD', name)
+
+    def delName(self, name):
+        self._nameOp('DELETE', name)
+
+    def _nameOp(self, prefix, name):
+        name = self.mangle(name)
+        scope = self.scope.check_name(name)
+        if scope == SC_LOCAL:
+            if not self.optimized:
+                self.emit(prefix + '_NAME', name)
+            else:
+                self.emit(prefix + '_FAST', name)
+        elif scope == SC_GLOBAL:
+            if not self.optimized:
+                self.emit(prefix + '_NAME', name)
+            else:
+                self.emit(prefix + '_GLOBAL', name)
+        elif scope == SC_FREE or scope == SC_CELL:
+            self.emit(prefix + '_DEREF', name)
+        else:
+            raise RuntimeError, "unsupported scope for var %s: %d" % \
+                  (name, scope)
+
+    def _implicitNameOp(self, prefix, name):
+        """Emit name ops for names generated implicitly by for loops
+
+        The interpreter generates names that start with a period or
+        dollar sign.  The symbol table ignores these names because
+        they aren't present in the program text.
+        """
+        if self.optimized:
+            self.emit(prefix + '_FAST', name)
+        else:
+            self.emit(prefix + '_NAME', name)
+
+    # The set_lineno() function and the explicit emit() calls for
+    # SET_LINENO below are only used to generate the line number table.
+    # As of Python 2.3, the interpreter does not have a SET_LINENO
+    # instruction.  pyassem treats SET_LINENO opcodes as a special case.
+
+    def set_lineno(self, node, force=False):
+        """Emit SET_LINENO if necessary.
+
+        The instruction is considered necessary if the node has a
+        lineno attribute and it is different than the last lineno
+        emitted.
+
+        Returns true if SET_LINENO was emitted.
+
+        There are no rules for when an AST node should have a lineno
+        attribute.  The transformer and AST code need to be reviewed
+        and a consistent policy implemented and documented.  Until
+        then, this method works around missing line numbers.
+        """
+        lineno = getattr(node, 'lineno', None)
+        if lineno is not None and (lineno != self.last_lineno
+                                   or force):
+            self.emit('SET_LINENO', lineno)
+            self.last_lineno = lineno
+            return True
+        return False
+
+    # The first few visitor methods handle nodes that generator new
+    # code objects.  They use class attributes to determine what
+    # specialized code generators to use.
+
+    NameFinder = LocalNameFinder
+    FunctionGen = None
+    ClassGen = None
+
+    def visitModule(self, node):
+        self.scopes = self.parseSymbols(node)
+        self.scope = self.scopes[node]
+        self.emit('SET_LINENO', 0)
+        if node.doc:
+            self.emit('LOAD_CONST', node.doc)
+            self.storeName('__doc__')
+        lnf = walk(node.node, self.NameFinder(), verbose=0)
+        self.locals.push(lnf.getLocals())
+        self.visit(node.node)
+        self.emit('LOAD_CONST', None)
+        self.emit('RETURN_VALUE')
+
+    def visitExpression(self, node):
+        self.set_lineno(node)
+        self.scopes = self.parseSymbols(node)
+        self.scope = self.scopes[node]
+        self.visit(node.node)
+        self.emit('RETURN_VALUE')
+
+    def visitFunction(self, node):
+        self._visitFuncOrLambda(node, isLambda=0)
+        if node.doc:
+            self.setDocstring(node.doc)
+        self.storeName(node.name)
+
+    def visitLambda(self, node):
+        self._visitFuncOrLambda(node, isLambda=1)
+
+    def _visitFuncOrLambda(self, node, isLambda=0):
+        if not isLambda and node.decorators:
+            for decorator in node.decorators.nodes:
+                self.visit(decorator)
+            ndecorators = len(node.decorators.nodes)
+        else:
+            ndecorators = 0
+
+        gen = self.FunctionGen(node, self.scopes, isLambda,
+                               self.class_name, self.get_module())
+        walk(node.code, gen)
+        gen.finish()
+        self.set_lineno(node)
+        for default in node.defaults:
+            self.visit(default)
+        self._makeClosure(gen, len(node.defaults))
+        for i in range(ndecorators):
+            self.emit('CALL_FUNCTION', 1)
+
+    def visitClass(self, node):
+        gen = self.ClassGen(node, self.scopes,
+                            self.get_module())
+        walk(node.code, gen)
+        gen.finish()
+        self.set_lineno(node)
+        self.emit('LOAD_CONST', node.name)
+        for base in node.bases:
+            self.visit(base)
+        self.emit('BUILD_TUPLE', len(node.bases))
+        self._makeClosure(gen, 0)
+        self.emit('CALL_FUNCTION', 0)
+        self.emit('BUILD_CLASS')
+        self.storeName(node.name)
+
+    # The rest are standard visitor methods
+
+    # The next few implement control-flow statements
+
+    def visitIf(self, node):
+        end = self.newBlock()
+        numtests = len(node.tests)
+        for i in range(numtests):
+            test, suite = node.tests[i]
+            if is_constant_false(test):
+                # XXX will need to check generator stuff here
+                continue
+            self.set_lineno(test)
+            self.visit(test)
+            nextTest = self.newBlock()
+            self.emit('JUMP_IF_FALSE', nextTest)
+            self.nextBlock()
+            self.emit('POP_TOP')
+            self.visit(suite)
+            self.emit('JUMP_FORWARD', end)
+            self.startBlock(nextTest)
+            self.emit('POP_TOP')
+        if node.else_:
+            self.visit(node.else_)
+        self.nextBlock(end)
+
+    def visitWhile(self, node):
+        self.set_lineno(node)
+
+        loop = self.newBlock()
+        else_ = self.newBlock()
+
+        after = self.newBlock()
+        self.emit('SETUP_LOOP', after)
+
+        self.nextBlock(loop)
+        self.setups.push((LOOP, loop))
+
+        self.set_lineno(node, force=True)
+        self.visit(node.test)
+        self.emit('JUMP_IF_FALSE', else_ or after)
+
+        self.nextBlock()
+        self.emit('POP_TOP')
+        self.visit(node.body)
+        self.emit('JUMP_ABSOLUTE', loop)
+
+        self.startBlock(else_) # or just the POPs if not else clause
+        self.emit('POP_TOP')
+        self.emit('POP_BLOCK')
+        self.setups.pop()
+        if node.else_:
+            self.visit(node.else_)
+        self.nextBlock(after)
+
+    def visitFor(self, node):
+        start = self.newBlock()
+        anchor = self.newBlock()
+        after = self.newBlock()
+        self.setups.push((LOOP, start))
+
+        self.set_lineno(node)
+        self.emit('SETUP_LOOP', after)
+        self.visit(node.list)
+        self.emit('GET_ITER')
+
+        self.nextBlock(start)
+        self.set_lineno(node, force=1)
+        self.emit('FOR_ITER', anchor)
+        self.visit(node.assign)
+        self.visit(node.body)
+        self.emit('JUMP_ABSOLUTE', start)
+        self.nextBlock(anchor)
+        self.emit('POP_BLOCK')
+        self.setups.pop()
+        if node.else_:
+            self.visit(node.else_)
+        self.nextBlock(after)
+
+    def visitBreak(self, node):
+        if not self.setups:
+            raise SyntaxError, "'break' outside loop (%s, %d)" % \
+                  (node.filename, node.lineno)
+        self.set_lineno(node)
+        self.emit('BREAK_LOOP')
+
+    def visitContinue(self, node):
+        if not self.setups:
+            raise SyntaxError, "'continue' outside loop (%s, %d)" % \
+                  (node.filename, node.lineno)
+        kind, block = self.setups.top()
+        if kind == LOOP:
+            self.set_lineno(node)
+            self.emit('JUMP_ABSOLUTE', block)
+            self.nextBlock()
+        elif kind == EXCEPT or kind == TRY_FINALLY:
+            self.set_lineno(node)
+            # find the block that starts the loop
+            top = len(self.setups)
+            while top > 0:
+                top = top - 1
+                kind, loop_block = self.setups[top]
+                if kind == LOOP:
+                    break
+            if kind != LOOP:
+                raise SyntaxError, "'continue' outside loop (%s, %d)" % \
+                      (node.filename, node.lineno)
+            self.emit('CONTINUE_LOOP', loop_block)
+            self.nextBlock()
+        elif kind == END_FINALLY:
+            msg = "'continue' not allowed inside 'finally' clause (%s, %d)"
+            raise SyntaxError, msg % (node.filename, node.lineno)
+
+    def visitTest(self, node, jump):
+        end = self.newBlock()
+        for child in node.nodes[:-1]:
+            self.visit(child)
+            self.emit(jump, end)
+            self.nextBlock()
+            self.emit('POP_TOP')
+        self.visit(node.nodes[-1])
+        self.nextBlock(end)
+
+    def visitAnd(self, node):
+        self.visitTest(node, 'JUMP_IF_FALSE')
+
+    def visitOr(self, node):
+        self.visitTest(node, 'JUMP_IF_TRUE')
+
+    def visitIfExp(self, node):
+        endblock = self.newBlock()
+        elseblock = self.newBlock()
+        self.visit(node.test)
+        self.emit('JUMP_IF_FALSE', elseblock)
+        self.emit('POP_TOP')
+        self.visit(node.then)
+        self.emit('JUMP_FORWARD', endblock)
+        self.nextBlock(elseblock)
+        self.emit('POP_TOP')
+        self.visit(node.else_)
+        self.nextBlock(endblock)
+
+    def visitCompare(self, node):
+        self.visit(node.expr)
+        cleanup = self.newBlock()
+        for op, code in node.ops[:-1]:
+            self.visit(code)
+            self.emit('DUP_TOP')
+            self.emit('ROT_THREE')
+            self.emit('COMPARE_OP', op)
+            self.emit('JUMP_IF_FALSE', cleanup)
+            self.nextBlock()
+            self.emit('POP_TOP')
+        # now do the last comparison
+        if node.ops:
+            op, code = node.ops[-1]
+            self.visit(code)
+            self.emit('COMPARE_OP', op)
+        if len(node.ops) > 1:
+            end = self.newBlock()
+            self.emit('JUMP_FORWARD', end)
+            self.startBlock(cleanup)
+            self.emit('ROT_TWO')
+            self.emit('POP_TOP')
+            self.nextBlock(end)
+
+    # list comprehensions
+    __list_count = 0
+
+    def visitListComp(self, node):
+        self.set_lineno(node)
+        # setup list
+        tmpname = "$list%d" % self.__list_count
+        self.__list_count = self.__list_count + 1
+        self.emit('BUILD_LIST', 0)
+        self.emit('DUP_TOP')
+        self._implicitNameOp('STORE', tmpname)
+
+        stack = []
+        for i, for_ in zip(range(len(node.quals)), node.quals):
+            start, anchor = self.visit(for_)
+            cont = None
+            for if_ in for_.ifs:
+                if cont is None:
+                    cont = self.newBlock()
+                self.visit(if_, cont)
+            stack.insert(0, (start, cont, anchor))
+
+        self._implicitNameOp('LOAD', tmpname)
+        self.visit(node.expr)
+        self.emit('LIST_APPEND')
+
+        for start, cont, anchor in stack:
+            if cont:
+                skip_one = self.newBlock()
+                self.emit('JUMP_FORWARD', skip_one)
+                self.startBlock(cont)
+                self.emit('POP_TOP')
+                self.nextBlock(skip_one)
+            self.emit('JUMP_ABSOLUTE', start)
+            self.startBlock(anchor)
+        self._implicitNameOp('DELETE', tmpname)
+
+        self.__list_count = self.__list_count - 1
+
+    def visitListCompFor(self, node):
+        start = self.newBlock()
+        anchor = self.newBlock()
+
+        self.visit(node.list)
+        self.emit('GET_ITER')
+        self.nextBlock(start)
+        self.set_lineno(node, force=True)
+        self.emit('FOR_ITER', anchor)
+        self.nextBlock()
+        self.visit(node.assign)
+        return start, anchor
+
+    def visitListCompIf(self, node, branch):
+        self.set_lineno(node, force=True)
+        self.visit(node.test)
+        self.emit('JUMP_IF_FALSE', branch)
+        self.newBlock()
+        self.emit('POP_TOP')
+
+    def _makeClosure(self, gen, args):
+        frees = gen.scope.get_free_vars()
+        if frees:
+            for name in frees:
+                self.emit('LOAD_CLOSURE', name)
+            self.emit('BUILD_TUPLE', len(frees))
+            self.emit('LOAD_CONST', gen)
+            self.emit('MAKE_CLOSURE', args)
+        else:
+            self.emit('LOAD_CONST', gen)
+            self.emit('MAKE_FUNCTION', args)
+
+    def visitGenExpr(self, node):
+        gen = GenExprCodeGenerator(node, self.scopes, self.class_name,
+                                   self.get_module())
+        walk(node.code, gen)
+        gen.finish()
+        self.set_lineno(node)
+        self._makeClosure(gen, 0)
+        # precomputation of outmost iterable
+        self.visit(node.code.quals[0].iter)
+        self.emit('GET_ITER')
+        self.emit('CALL_FUNCTION', 1)
+
+    def visitGenExprInner(self, node):
+        self.set_lineno(node)
+        # setup list
+
+        stack = []
+        for i, for_ in zip(range(len(node.quals)), node.quals):
+            start, anchor, end = self.visit(for_)
+            cont = None
+            for if_ in for_.ifs:
+                if cont is None:
+                    cont = self.newBlock()
+                self.visit(if_, cont)
+            stack.insert(0, (start, cont, anchor, end))
+
+        self.visit(node.expr)
+        self.emit('YIELD_VALUE')
+        self.emit('POP_TOP')
+
+        for start, cont, anchor, end in stack:
+            if cont:
+                skip_one = self.newBlock()
+                self.emit('JUMP_FORWARD', skip_one)
+                self.startBlock(cont)
+                self.emit('POP_TOP')
+                self.nextBlock(skip_one)
+            self.emit('JUMP_ABSOLUTE', start)
+            self.startBlock(anchor)
+            self.emit('POP_BLOCK')
+            self.setups.pop()
+            self.startBlock(end)
+
+        self.emit('LOAD_CONST', None)
+
+    def visitGenExprFor(self, node):
+        start = self.newBlock()
+        anchor = self.newBlock()
+        end = self.newBlock()
+
+        self.setups.push((LOOP, start))
+        self.emit('SETUP_LOOP', end)
+
+        if node.is_outmost:
+            self.loadName('.0')
+        else:
+            self.visit(node.iter)
+            self.emit('GET_ITER')
+
+        self.nextBlock(start)
+        self.set_lineno(node, force=True)
+        self.emit('FOR_ITER', anchor)
+        self.nextBlock()
+        self.visit(node.assign)
+        return start, anchor, end
+
+    def visitGenExprIf(self, node, branch):
+        self.set_lineno(node, force=True)
+        self.visit(node.test)
+        self.emit('JUMP_IF_FALSE', branch)
+        self.newBlock()
+        self.emit('POP_TOP')
+
+    # exception related
+
+    def visitAssert(self, node):
+        # XXX would be interesting to implement this via a
+        # transformation of the AST before this stage
+        if __debug__:
+            end = self.newBlock()
+            self.set_lineno(node)
+            # XXX AssertionError appears to be special case -- it is always
+            # loaded as a global even if there is a local name.  I guess this
+            # is a sort of renaming op.
+            self.nextBlock()
+            self.visit(node.test)
+            self.emit('JUMP_IF_TRUE', end)
+            self.nextBlock()
+            self.emit('POP_TOP')
+            self.emit('LOAD_GLOBAL', 'AssertionError')
+            if node.fail:
+                self.visit(node.fail)
+                self.emit('RAISE_VARARGS', 2)
+            else:
+                self.emit('RAISE_VARARGS', 1)
+            self.nextBlock(end)
+            self.emit('POP_TOP')
+
+    def visitRaise(self, node):
+        self.set_lineno(node)
+        n = 0
+        if node.expr1:
+            self.visit(node.expr1)
+            n = n + 1
+        if node.expr2:
+            self.visit(node.expr2)
+            n = n + 1
+        if node.expr3:
+            self.visit(node.expr3)
+            n = n + 1
+        self.emit('RAISE_VARARGS', n)
+
+    def visitTryExcept(self, node):
+        body = self.newBlock()
+        handlers = self.newBlock()
+        end = self.newBlock()
+        if node.else_:
+            lElse = self.newBlock()
+        else:
+            lElse = end
+        self.set_lineno(node)
+        self.emit('SETUP_EXCEPT', handlers)
+        self.nextBlock(body)
+        self.setups.push((EXCEPT, body))
+        self.visit(node.body)
+        self.emit('POP_BLOCK')
+        self.setups.pop()
+        self.emit('JUMP_FORWARD', lElse)
+        self.startBlock(handlers)
+
+        last = len(node.handlers) - 1
+        for i in range(len(node.handlers)):
+            expr, target, body = node.handlers[i]
+            self.set_lineno(expr)
+            if expr:
+                self.emit('DUP_TOP')
+                self.visit(expr)
+                self.emit('COMPARE_OP', 'exception match')
+                next = self.newBlock()
+                self.emit('JUMP_IF_FALSE', next)
+                self.nextBlock()
+                self.emit('POP_TOP')
+            self.emit('POP_TOP')
+            if target:
+                self.visit(target)
+            else:
+                self.emit('POP_TOP')
+            self.emit('POP_TOP')
+            self.visit(body)
+            self.emit('JUMP_FORWARD', end)
+            if expr:
+                self.nextBlock(next)
+            else:
+                self.nextBlock()
+            if expr: # XXX
+                self.emit('POP_TOP')
+        self.emit('END_FINALLY')
+        if node.else_:
+            self.nextBlock(lElse)
+            self.visit(node.else_)
+        self.nextBlock(end)
+
+    def visitTryFinally(self, node):
+        body = self.newBlock()
+        final = self.newBlock()
+        self.set_lineno(node)
+        self.emit('SETUP_FINALLY', final)
+        self.nextBlock(body)
+        self.setups.push((TRY_FINALLY, body))
+        self.visit(node.body)
+        self.emit('POP_BLOCK')
+        self.setups.pop()
+        self.emit('LOAD_CONST', None)
+        self.nextBlock(final)
+        self.setups.push((END_FINALLY, final))
+        self.visit(node.final)
+        self.emit('END_FINALLY')
+        self.setups.pop()
+
+    __with_count = 0
+
+    def visitWith(self, node):
+        body = self.newBlock()
+        final = self.newBlock()
+        valuevar = "$value%d" % self.__with_count
+        self.__with_count += 1
+        self.set_lineno(node)
+        self.visit(node.expr)
+        self.emit('DUP_TOP')
+        self.emit('LOAD_ATTR', '__exit__')
+        self.emit('ROT_TWO')
+        self.emit('LOAD_ATTR', '__enter__')
+        self.emit('CALL_FUNCTION', 0)
+        if node.vars is None:
+            self.emit('POP_TOP')
+        else:
+            self._implicitNameOp('STORE', valuevar)
+        self.emit('SETUP_FINALLY', final)
+        self.nextBlock(body)
+        self.setups.push((TRY_FINALLY, body))
+        if node.vars is not None:
+            self._implicitNameOp('LOAD', valuevar)
+            self._implicitNameOp('DELETE', valuevar)
+            self.visit(node.vars)
+        self.visit(node.body)
+        self.emit('POP_BLOCK')
+        self.setups.pop()
+        self.emit('LOAD_CONST', None)
+        self.nextBlock(final)
+        self.setups.push((END_FINALLY, final))
+        self.emit('WITH_CLEANUP')
+        self.emit('END_FINALLY')
+        self.setups.pop()
+        self.__with_count -= 1
+
+    # misc
+
+    def visitDiscard(self, node):
+        self.set_lineno(node)
+        self.visit(node.expr)
+        self.emit('POP_TOP')
+
+    def visitConst(self, node):
+        self.emit('LOAD_CONST', node.value)
+
+    def visitKeyword(self, node):
+        self.emit('LOAD_CONST', node.name)
+        self.visit(node.expr)
+
+    def visitGlobal(self, node):
+        # no code to generate
+        pass
+
+    def visitName(self, node):
+        self.set_lineno(node)
+        self.loadName(node.name)
+
+    def visitPass(self, node):
+        self.set_lineno(node)
+
+    def visitImport(self, node):
+        self.set_lineno(node)
+        level = 0 if self.graph.checkFlag(CO_FUTURE_ABSIMPORT) else -1
+        for name, alias in node.names:
+            if VERSION > 1:
+                self.emit('LOAD_CONST', level)
+                self.emit('LOAD_CONST', None)
+            self.emit('IMPORT_NAME', name)
+            mod = name.split(".")[0]
+            if alias:
+                self._resolveDots(name)
+                self.storeName(alias)
+            else:
+                self.storeName(mod)
+
+    def visitFrom(self, node):
+        self.set_lineno(node)
+        level = node.level
+        if level == 0 and not self.graph.checkFlag(CO_FUTURE_ABSIMPORT):
+            level = -1
+        fromlist = tuple(name for (name, alias) in node.names)
+        if VERSION > 1:
+            self.emit('LOAD_CONST', level)
+            self.emit('LOAD_CONST', fromlist)
+        self.emit('IMPORT_NAME', node.modname)
+        for name, alias in node.names:
+            if VERSION > 1:
+                if name == '*':
+                    self.namespace = 0
+                    self.emit('IMPORT_STAR')
+                    # There can only be one name w/ from ... import *
+                    assert len(node.names) == 1
+                    return
+                else:
+                    self.emit('IMPORT_FROM', name)
+                    self._resolveDots(name)
+                    self.storeName(alias or name)
+            else:
+                self.emit('IMPORT_FROM', name)
+        self.emit('POP_TOP')
+
+    def _resolveDots(self, name):
+        elts = name.split(".")
+        if len(elts) == 1:
+            return
+        for elt in elts[1:]:
+            self.emit('LOAD_ATTR', elt)
+
+    def visitGetattr(self, node):
+        self.visit(node.expr)
+        self.emit('LOAD_ATTR', self.mangle(node.attrname))
+
+    # next five implement assignments
+
+    def visitAssign(self, node):
+        self.set_lineno(node)
+        self.visit(node.expr)
+        dups = len(node.nodes) - 1
+        for i in range(len(node.nodes)):
+            elt = node.nodes[i]
+            if i < dups:
+                self.emit('DUP_TOP')
+            if isinstance(elt, ast.Node):
+                self.visit(elt)
+
+    def visitAssName(self, node):
+        if node.flags == 'OP_ASSIGN':
+            self.storeName(node.name)
+        elif node.flags == 'OP_DELETE':
+            self.set_lineno(node)
+            self.delName(node.name)
+        else:
+            print "oops", node.flags
+
+    def visitAssAttr(self, node):
+        self.visit(node.expr)
+        if node.flags == 'OP_ASSIGN':
+            self.emit('STORE_ATTR', self.mangle(node.attrname))
+        elif node.flags == 'OP_DELETE':
+            self.emit('DELETE_ATTR', self.mangle(node.attrname))
+        else:
+            print "warning: unexpected flags:", node.flags
+            print node
+
+    def _visitAssSequence(self, node, op='UNPACK_SEQUENCE'):
+        if findOp(node) != 'OP_DELETE':
+            self.emit(op, len(node.nodes))
+        for child in node.nodes:
+            self.visit(child)
+
+    if VERSION > 1:
+        visitAssTuple = _visitAssSequence
+        visitAssList = _visitAssSequence
+    else:
+        def visitAssTuple(self, node):
+            self._visitAssSequence(node, 'UNPACK_TUPLE')
+
+        def visitAssList(self, node):
+            self._visitAssSequence(node, 'UNPACK_LIST')
+
+    # augmented assignment
+
+    def visitAugAssign(self, node):
+        self.set_lineno(node)
+        aug_node = wrap_aug(node.node)
+        self.visit(aug_node, "load")
+        self.visit(node.expr)
+        self.emit(self._augmented_opcode[node.op])
+        self.visit(aug_node, "store")
+
+    _augmented_opcode = {
+        '+=' : 'INPLACE_ADD',
+        '-=' : 'INPLACE_SUBTRACT',
+        '*=' : 'INPLACE_MULTIPLY',
+        '/=' : 'INPLACE_DIVIDE',
+        '//=': 'INPLACE_FLOOR_DIVIDE',
+        '%=' : 'INPLACE_MODULO',
+        '**=': 'INPLACE_POWER',
+        '>>=': 'INPLACE_RSHIFT',
+        '<<=': 'INPLACE_LSHIFT',
+        '&=' : 'INPLACE_AND',
+        '^=' : 'INPLACE_XOR',
+        '|=' : 'INPLACE_OR',
+        }
+
+    def visitAugName(self, node, mode):
+        if mode == "load":
+            self.loadName(node.name)
+        elif mode == "store":
+            self.storeName(node.name)
+
+    def visitAugGetattr(self, node, mode):
+        if mode == "load":
+            self.visit(node.expr)
+            self.emit('DUP_TOP')
+            self.emit('LOAD_ATTR', self.mangle(node.attrname))
+        elif mode == "store":
+            self.emit('ROT_TWO')
+            self.emit('STORE_ATTR', self.mangle(node.attrname))
+
+    def visitAugSlice(self, node, mode):
+        if mode == "load":
+            self.visitSlice(node, 1)
+        elif mode == "store":
+            slice = 0
+            if node.lower:
+                slice = slice | 1
+            if node.upper:
+                slice = slice | 2
+            if slice == 0:
+                self.emit('ROT_TWO')
+            elif slice == 3:
+                self.emit('ROT_FOUR')
+            else:
+                self.emit('ROT_THREE')
+            self.emit('STORE_SLICE+%d' % slice)
+
+    def visitAugSubscript(self, node, mode):
+        if mode == "load":
+            self.visitSubscript(node, 1)
+        elif mode == "store":
+            self.emit('ROT_THREE')
+            self.emit('STORE_SUBSCR')
+
+    def visitExec(self, node):
+        self.visit(node.expr)
+        if node.locals is None:
+            self.emit('LOAD_CONST', None)
+        else:
+            self.visit(node.locals)
+        if node.globals is None:
+            self.emit('DUP_TOP')
+        else:
+            self.visit(node.globals)
+        self.emit('EXEC_STMT')
+
+    def visitCallFunc(self, node):
+        pos = 0
+        kw = 0
+        self.set_lineno(node)
+        self.visit(node.node)
+        for arg in node.args:
+            self.visit(arg)
+            if isinstance(arg, ast.Keyword):
+                kw = kw + 1
+            else:
+                pos = pos + 1
+        if node.star_args is not None:
+            self.visit(node.star_args)
+        if node.dstar_args is not None:
+            self.visit(node.dstar_args)
+        have_star = node.star_args is not None
+        have_dstar = node.dstar_args is not None
+        opcode = callfunc_opcode_info[have_star, have_dstar]
+        self.emit(opcode, kw << 8 | pos)
+
+    def visitPrint(self, node, newline=0):
+        self.set_lineno(node)
+        if node.dest:
+            self.visit(node.dest)
+        for child in node.nodes:
+            if node.dest:
+                self.emit('DUP_TOP')
+            self.visit(child)
+            if node.dest:
+                self.emit('ROT_TWO')
+                self.emit('PRINT_ITEM_TO')
+            else:
+                self.emit('PRINT_ITEM')
+        if node.dest and not newline:
+            self.emit('POP_TOP')
+
+    def visitPrintnl(self, node):
+        self.visitPrint(node, newline=1)
+        if node.dest:
+            self.emit('PRINT_NEWLINE_TO')
+        else:
+            self.emit('PRINT_NEWLINE')
+
+    def visitReturn(self, node):
+        self.set_lineno(node)
+        self.visit(node.value)
+        self.emit('RETURN_VALUE')
+
+    def visitYield(self, node):
+        self.set_lineno(node)
+        self.visit(node.value)
+        self.emit('YIELD_VALUE')
+
+    # slice and subscript stuff
+
+    def visitSlice(self, node, aug_flag=None):
+        # aug_flag is used by visitAugSlice
+        self.visit(node.expr)
+        slice = 0
+        if node.lower:
+            self.visit(node.lower)
+            slice = slice | 1
+        if node.upper:
+            self.visit(node.upper)
+            slice = slice | 2
+        if aug_flag:
+            if slice == 0:
+                self.emit('DUP_TOP')
+            elif slice == 3:
+                self.emit('DUP_TOPX', 3)
+            else:
+                self.emit('DUP_TOPX', 2)
+        if node.flags == 'OP_APPLY':
+            self.emit('SLICE+%d' % slice)
+        elif node.flags == 'OP_ASSIGN':
+            self.emit('STORE_SLICE+%d' % slice)
+        elif node.flags == 'OP_DELETE':
+            self.emit('DELETE_SLICE+%d' % slice)
+        else:
+            print "weird slice", node.flags
+            raise
+
+    def visitSubscript(self, node, aug_flag=None):
+        self.visit(node.expr)
+        for sub in node.subs:
+            self.visit(sub)
+        if len(node.subs) > 1:
+            self.emit('BUILD_TUPLE', len(node.subs))
+        if aug_flag:
+            self.emit('DUP_TOPX', 2)
+        if node.flags == 'OP_APPLY':
+            self.emit('BINARY_SUBSCR')
+        elif node.flags == 'OP_ASSIGN':
+            self.emit('STORE_SUBSCR')
+        elif node.flags == 'OP_DELETE':
+            self.emit('DELETE_SUBSCR')
+
+    # binary ops
+
+    def binaryOp(self, node, op):
+        self.visit(node.left)
+        self.visit(node.right)
+        self.emit(op)
+
+    def visitAdd(self, node):
+        return self.binaryOp(node, 'BINARY_ADD')
+
+    def visitSub(self, node):
+        return self.binaryOp(node, 'BINARY_SUBTRACT')
+
+    def visitMul(self, node):
+        return self.binaryOp(node, 'BINARY_MULTIPLY')
+
+    def visitDiv(self, node):
+        return self.binaryOp(node, self._div_op)
+
+    def visitFloorDiv(self, node):
+        return self.binaryOp(node, 'BINARY_FLOOR_DIVIDE')
+
+    def visitMod(self, node):
+        return self.binaryOp(node, 'BINARY_MODULO')
+
+    def visitPower(self, node):
+        return self.binaryOp(node, 'BINARY_POWER')
+
+    def visitLeftShift(self, node):
+        return self.binaryOp(node, 'BINARY_LSHIFT')
+
+    def visitRightShift(self, node):
+        return self.binaryOp(node, 'BINARY_RSHIFT')
+
+    # unary ops
+
+    def unaryOp(self, node, op):
+        self.visit(node.expr)
+        self.emit(op)
+
+    def visitInvert(self, node):
+        return self.unaryOp(node, 'UNARY_INVERT')
+
+    def visitUnarySub(self, node):
+        return self.unaryOp(node, 'UNARY_NEGATIVE')
+
+    def visitUnaryAdd(self, node):
+        return self.unaryOp(node, 'UNARY_POSITIVE')
+
+    def visitUnaryInvert(self, node):
+        return self.unaryOp(node, 'UNARY_INVERT')
+
+    def visitNot(self, node):
+        return self.unaryOp(node, 'UNARY_NOT')
+
+    def visitBackquote(self, node):
+        return self.unaryOp(node, 'UNARY_CONVERT')
+
+    # bit ops
+
+    def bitOp(self, nodes, op):
+        self.visit(nodes[0])
+        for node in nodes[1:]:
+            self.visit(node)
+            self.emit(op)
+
+    def visitBitand(self, node):
+        return self.bitOp(node.nodes, 'BINARY_AND')
+
+    def visitBitor(self, node):
+        return self.bitOp(node.nodes, 'BINARY_OR')
+
+    def visitBitxor(self, node):
+        return self.bitOp(node.nodes, 'BINARY_XOR')
+
+    # object constructors
+
+    def visitEllipsis(self, node):
+        self.emit('LOAD_CONST', Ellipsis)
+
+    def visitTuple(self, node):
+        self.set_lineno(node)
+        for elt in node.nodes:
+            self.visit(elt)
+        self.emit('BUILD_TUPLE', len(node.nodes))
+
+    def visitList(self, node):
+        self.set_lineno(node)
+        for elt in node.nodes:
+            self.visit(elt)
+        self.emit('BUILD_LIST', len(node.nodes))
+
+    def visitSliceobj(self, node):
+        for child in node.nodes:
+            self.visit(child)
+        self.emit('BUILD_SLICE', len(node.nodes))
+
+    def visitDict(self, node):
+        self.set_lineno(node)
+        self.emit('BUILD_MAP', 0)
+        for k, v in node.items:
+            self.emit('DUP_TOP')
+            self.visit(k)
+            self.visit(v)
+            self.emit('ROT_THREE')
+            self.emit('STORE_SUBSCR')
+
+class NestedScopeMixin:
+    """Defines initClass() for nested scoping (Python 2.2-compatible)"""
+    def initClass(self):
+        self.__class__.NameFinder = LocalNameFinder
+        self.__class__.FunctionGen = FunctionCodeGenerator
+        self.__class__.ClassGen = ClassCodeGenerator
+
+class ModuleCodeGenerator(NestedScopeMixin, CodeGenerator):
+    __super_init = CodeGenerator.__init__
+
+    scopes = None
+
+    def __init__(self, tree):
+        self.graph = pyassem.PyFlowGraph("<module>", tree.filename)
+        self.futures = future.find_futures(tree)
+        self.__super_init()
+        walk(tree, self)
+
+    def get_module(self):
+        return self
+
+class ExpressionCodeGenerator(NestedScopeMixin, CodeGenerator):
+    __super_init = CodeGenerator.__init__
+
+    scopes = None
+    futures = ()
+
+    def __init__(self, tree):
+        self.graph = pyassem.PyFlowGraph("<expression>", tree.filename)
+        self.__super_init()
+        walk(tree, self)
+
+    def get_module(self):
+        return self
+
+class InteractiveCodeGenerator(NestedScopeMixin, CodeGenerator):
+
+    __super_init = CodeGenerator.__init__
+
+    scopes = None
+    futures = ()
+
+    def __init__(self, tree):
+        self.graph = pyassem.PyFlowGraph("<interactive>", tree.filename)
+        self.__super_init()
+        self.set_lineno(tree)
+        walk(tree, self)
+        self.emit('RETURN_VALUE')
+
+    def get_module(self):
+        return self
+
+    def visitDiscard(self, node):
+        # XXX Discard means it's an expression.  Perhaps this is a bad
+        # name.
+        self.visit(node.expr)
+        self.emit('PRINT_EXPR')
+
+class AbstractFunctionCode:
+    optimized = 1
+    lambdaCount = 0
+
+    def __init__(self, func, scopes, isLambda, class_name, mod):
+        self.class_name = class_name
+        self.module = mod
+        if isLambda:
+            klass = FunctionCodeGenerator
+            name = "<lambda.%d>" % klass.lambdaCount
+            klass.lambdaCount = klass.lambdaCount + 1
+        else:
+            name = func.name
+
+        args, hasTupleArg = generateArgList(func.argnames)
+        self.graph = pyassem.PyFlowGraph(name, func.filename, args,
+                                         optimized=1)
+        self.isLambda = isLambda
+        self.super_init()
+
+        if not isLambda and func.doc:
+            self.setDocstring(func.doc)
+
+        lnf = walk(func.code, self.NameFinder(args), verbose=0)
+        self.locals.push(lnf.getLocals())
+        if func.varargs:
+            self.graph.setFlag(CO_VARARGS)
+        if func.kwargs:
+            self.graph.setFlag(CO_VARKEYWORDS)
+        self.set_lineno(func)
+        if hasTupleArg:
+            self.generateArgUnpack(func.argnames)
+
+    def get_module(self):
+        return self.module
+
+    def finish(self):
+        self.graph.startExitBlock()
+        if not self.isLambda:
+            self.emit('LOAD_CONST', None)
+        self.emit('RETURN_VALUE')
+
+    def generateArgUnpack(self, args):
+        for i in range(len(args)):
+            arg = args[i]
+            if isinstance(arg, tuple):
+                self.emit('LOAD_FAST', '.%d' % (i * 2))
+                self.unpackSequence(arg)
+
+    def unpackSequence(self, tup):
+        if VERSION > 1:
+            self.emit('UNPACK_SEQUENCE', len(tup))
+        else:
+            self.emit('UNPACK_TUPLE', len(tup))
+        for elt in tup:
+            if isinstance(elt, tuple):
+                self.unpackSequence(elt)
+            else:
+                self._nameOp('STORE', elt)
+
+    unpackTuple = unpackSequence
+
+class FunctionCodeGenerator(NestedScopeMixin, AbstractFunctionCode,
+                            CodeGenerator):
+    super_init = CodeGenerator.__init__ # call be other init
+    scopes = None
+
+    __super_init = AbstractFunctionCode.__init__
+
+    def __init__(self, func, scopes, isLambda, class_name, mod):
+        self.scopes = scopes
+        self.scope = scopes[func]
+        self.__super_init(func, scopes, isLambda, class_name, mod)
+        self.graph.setFreeVars(self.scope.get_free_vars())
+        self.graph.setCellVars(self.scope.get_cell_vars())
+        if self.scope.generator is not None:
+            self.graph.setFlag(CO_GENERATOR)
+
+class GenExprCodeGenerator(NestedScopeMixin, AbstractFunctionCode,
+                           CodeGenerator):
+    super_init = CodeGenerator.__init__ # call be other init
+    scopes = None
+
+    __super_init = AbstractFunctionCode.__init__
+
+    def __init__(self, gexp, scopes, class_name, mod):
+        self.scopes = scopes
+        self.scope = scopes[gexp]
+        self.__super_init(gexp, scopes, 1, class_name, mod)
+        self.graph.setFreeVars(self.scope.get_free_vars())
+        self.graph.setCellVars(self.scope.get_cell_vars())
+        self.graph.setFlag(CO_GENERATOR)
+
+class AbstractClassCode:
+
+    def __init__(self, klass, scopes, module):
+        self.class_name = klass.name
+        self.module = module
+        self.graph = pyassem.PyFlowGraph(klass.name, klass.filename,
+                                           optimized=0, klass=1)
+        self.super_init()
+        lnf = walk(klass.code, self.NameFinder(), verbose=0)
+        self.locals.push(lnf.getLocals())
+        self.graph.setFlag(CO_NEWLOCALS)
+        if klass.doc:
+            self.setDocstring(klass.doc)
+
+    def get_module(self):
+        return self.module
+
+    def finish(self):
+        self.graph.startExitBlock()
+        self.emit('LOAD_LOCALS')
+        self.emit('RETURN_VALUE')
+
+class ClassCodeGenerator(NestedScopeMixin, AbstractClassCode, CodeGenerator):
+    super_init = CodeGenerator.__init__
+    scopes = None
+
+    __super_init = AbstractClassCode.__init__
+
+    def __init__(self, klass, scopes, module):
+        self.scopes = scopes
+        self.scope = scopes[klass]
+        self.__super_init(klass, scopes, module)
+        self.graph.setFreeVars(self.scope.get_free_vars())
+        self.graph.setCellVars(self.scope.get_cell_vars())
+        self.set_lineno(klass)
+        self.emit("LOAD_GLOBAL", "__name__")
+        self.storeName("__module__")
+        if klass.doc:
+            self.emit("LOAD_CONST", klass.doc)
+            self.storeName('__doc__')
+
+def generateArgList(arglist):
+    """Generate an arg list marking TupleArgs"""
+    args = []
+    extra = []
+    count = 0
+    for i in range(len(arglist)):
+        elt = arglist[i]
+        if isinstance(elt, str):
+            args.append(elt)
+        elif isinstance(elt, tuple):
+            args.append(TupleArg(i * 2, elt))
+            extra.extend(misc.flatten(elt))
+            count = count + 1
+        else:
+            raise ValueError, "unexpect argument type:", elt
+    return args + extra, count
+
+def findOp(node):
+    """Find the op (DELETE, LOAD, STORE) in an AssTuple tree"""
+    v = OpFinder()
+    walk(node, v, verbose=0)
+    return v.op
+
+class OpFinder:
+    def __init__(self):
+        self.op = None
+    def visitAssName(self, node):
+        if self.op is None:
+            self.op = node.flags
+        elif self.op != node.flags:
+            raise ValueError, "mixed ops in stmt"
+    visitAssAttr = visitAssName
+    visitSubscript = visitAssName
+
+class Delegator:
+    """Base class to support delegation for augmented assignment nodes
+
+    To generator code for augmented assignments, we use the following
+    wrapper classes.  In visitAugAssign, the left-hand expression node
+    is visited twice.  The first time the visit uses the normal method
+    for that node .  The second time the visit uses a different method
+    that generates the appropriate code to perform the assignment.
+    These delegator classes wrap the original AST nodes in order to
+    support the variant visit methods.
+    """
+    def __init__(self, obj):
+        self.obj = obj
+
+    def __getattr__(self, attr):
+        return getattr(self.obj, attr)
+
+class AugGetattr(Delegator):
+    pass
+
+class AugName(Delegator):
+    pass
+
+class AugSlice(Delegator):
+    pass
+
+class AugSubscript(Delegator):
+    pass
+
+wrapper = {
+    ast.Getattr: AugGetattr,
+    ast.Name: AugName,
+    ast.Slice: AugSlice,
+    ast.Subscript: AugSubscript,
+    }
+
+def wrap_aug(node):
+    return wrapper[node.__class__](node)
+
+if __name__ == "__main__":
+    for file in sys.argv[1:]:
+        compileFile(file)
diff -r 000000000000 -r 7bec0014e871 compiler/symbols.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/compiler/symbols.py	Fri May 18 20:51:41 2012 +0200
@@ -0,0 +1,461 @@
+"""Module symbol-table generator"""
+
+from compiler import ast
+from compiler.consts import SC_LOCAL, SC_GLOBAL, SC_FREE, SC_CELL, SC_UNKNOWN
+from compiler.misc import mangle
+import types
+
+
+import sys
+
+MANGLE_LEN = 256
+
+class Scope:
+    # XXX how much information do I need about each name?
+    def __init__(self, name, module, klass=None):
+        self.name = name
+        self.module = module
+        self.defs = {}
+        self.uses = {}
+        self.globals = {}
+        self.params = {}
+        self.frees = {}
+        self.cells = {}
+        self.children = []
+        # nested is true if the class could contain free variables,
+        # i.e. if it is nested within another function.
+        self.nested = None
+        self.generator = None
+        self.klass = None
+        if klass is not None:
+            for i in range(len(klass)):
+                if klass[i] != '_':
+                    self.klass = klass[i:]
+                    break
+
+    def __repr__(self):
+        return "<%s: %s>" % (self.__class__.__name__, self.name)
+
+    def mangle(self, name):
+        if self.klass is None:
+            return name
+        return mangle(name, self.klass)
+
+    def add_def(self, name):
+        self.defs[self.mangle(name)] = 1
+
+    def add_use(self, name):
+        self.uses[self.mangle(name)] = 1
+
+    def add_global(self, name):
+        name = self.mangle(name)
+        if name in self.uses or name in self.defs:
+            pass # XXX warn about global following def/use
+        if name in self.params:
+            raise SyntaxError, "%s in %s is global and parameter" % \
+                  (name, self.name)
+        self.globals[name] = 1
+        self.module.add_def(name)
+
+    def add_param(self, name):
+        name = self.mangle(name)
+        self.defs[name] = 1
+        self.params[name] = 1
+
+    def get_names(self):
+        d = {}
+        d.update(self.defs)
+        d.update(self.uses)
+        d.update(self.globals)
+        return d.keys()
+
+    def add_child(self, child):
+        self.children.append(child)
+
+    def get_children(self):
+        return self.children
+
+    def DEBUG(self):
+        print >> sys.stderr, self.name, self.nested and "nested" or ""
+        print >> sys.stderr, "\tglobals: ", self.globals
+        print >> sys.stderr, "\tcells: ", self.cells
+        print >> sys.stderr, "\tdefs: ", self.defs
+        print >> sys.stderr, "\tuses: ", self.uses
+        print >> sys.stderr, "\tfrees:", self.frees
+
+    def check_name(self, name):
+        """Return scope of name.
+
+        The scope of a name could be LOCAL, GLOBAL, FREE, or CELL.
+        """
+        if name in self.globals:
+            return SC_GLOBAL
+        if name in self.cells:
+            return SC_CELL
+        if name in self.defs:
+            return SC_LOCAL
+        if self.nested and (name in self.frees or name in self.uses):
+            return SC_FREE
+        if self.nested:
+            return SC_UNKNOWN
+        else:
+            return SC_GLOBAL
+
+    def get_free_vars(self):
+        if not self.nested:
+            return ()
+        free = {}
+        free.update(self.frees)
+        for name in self.uses.keys():
+            if name not in self.defs and name not in self.globals:
+                free[name] = 1
+        return free.keys()
+
+    def handle_children(self):
+        for child in self.children:
+            frees = child.get_free_vars()
+            globals = self.add_frees(frees)
+            for name in globals:
+                child.force_global(name)
+
+    def force_global(self, name):
+        """Force name to be global in scope.
+
+        Some child of the current node had a free reference to name.
+        When the child was processed, it was labelled a free
+        variable.  Now that all its enclosing scope have been
+        processed, the name is known to be a global or builtin.  So
+        walk back down the child chain and set the name to be global
+        rather than free.
+
+        Be careful to stop if a child does not think the name is
+        free.
+        """
+        self.globals[name] = 1
+        if name in self.frees:
+            del self.frees[name]
+        for child in self.children:
+            if child.check_name(name) == SC_FREE:
+                child.force_global(name)
+
+    def add_frees(self, names):
+        """Process list of free vars from nested scope.
+
+        Returns a list of names that are either 1) declared global in the
+        parent or 2) undefined in a top-level parent.  In either case,
+        the nested scope should treat them as globals.
+        """
+        child_globals = []
+        for name in names:
+            sc = self.check_name(name)
+            if self.nested:
+                if sc == SC_UNKNOWN or sc == SC_FREE \
+                   or isinstance(self, ClassScope):
+                    self.frees[name] = 1
+                elif sc == SC_GLOBAL:
+                    child_globals.append(name)
+                elif isinstance(self, FunctionScope) and sc == SC_LOCAL:
+                    self.cells[name] = 1
+                elif sc != SC_CELL:
+                    child_globals.append(name)
+            else:
+                if sc == SC_LOCAL:
+                    self.cells[name] = 1
+                elif sc != SC_CELL:
+                    child_globals.append(name)
+        return child_globals
+
+    def get_cell_vars(self):
+        return self.cells.keys()
+
+class ModuleScope(Scope):
+    __super_init = Scope.__init__
+
+    def __init__(self):
+        self.__super_init("global", self)
+
+class FunctionScope(Scope):
+    pass
+
+class GenExprScope(Scope):
+    __super_init = Scope.__init__
+
+    __counter = 1
+
+    def __init__(self, module, klass=None):
+        i = self.__counter
+        self.__counter += 1
+        self.__super_init("generator expression<%d>"%i, module, klass)
+        self.add_param('.0')
+
+    def get_names(self):
+        keys = Scope.get_names(self)
+        return keys
+
+class LambdaScope(FunctionScope):
+    __super_init = Scope.__init__
+
+    __counter = 1
+
+    def __init__(self, module, klass=None):
+        i = self.__counter
+        self.__counter += 1
+        self.__super_init("lambda.%d" % i, module, klass)
+
+class ClassScope(Scope):
+    __super_init = Scope.__init__
+
+    def __init__(self, name, module):
+        self.__super_init(name, module, name)
+
+class SymbolVisitor:
+    def __init__(self):
+        self.scopes = {}
+        self.klass = None
+
+    # node that define new scopes
+
+    def visitModule(self, node):
+        scope = self.module = self.scopes[node] = ModuleScope()
+        self.visit(node.node, scope)
+
+    visitExpression = visitModule
+
+    def visitFunction(self, node, parent):
+        if node.decorators:
+            self.visit(node.decorators, parent)
+        parent.add_def(node.name)
+        for n in node.defaults:
+            self.visit(n, parent)
+        scope = FunctionScope(node.name, self.module, self.klass)
+        if parent.nested or isinstance(parent, FunctionScope):
+            scope.nested = 1
+        self.scopes[node] = scope
+        self._do_args(scope, node.argnames)
+        self.visit(node.code, scope)
+        self.handle_free_vars(scope, parent)
+
+    def visitGenExpr(self, node, parent):
+        scope = GenExprScope(self.module, self.klass);
+        if parent.nested or isinstance(parent, FunctionScope) \
+                or isinstance(parent, GenExprScope):
+            scope.nested = 1
+
+        self.scopes[node] = scope
+        self.visit(node.code, scope)
+
+        self.handle_free_vars(scope, parent)
+
+    def visitGenExprInner(self, node, scope):
+        for genfor in node.quals:
+            self.visit(genfor, scope)
+
+        self.visit(node.expr, scope)
+
+    def visitGenExprFor(self, node, scope):
+        self.visit(node.assign, scope, 1)
+        self.visit(node.iter, scope)
+        for if_ in node.ifs:
+            self.visit(if_, scope)
+
+    def visitGenExprIf(self, node, scope):
+        self.visit(node.test, scope)
+
+    def visitLambda(self, node, parent, assign=0):
+        # Lambda is an expression, so it could appear in an expression
+        # context where assign is passed.  The transformer should catch
+        # any code that has a lambda on the left-hand side.
+        assert not assign
+
+        for n in node.defaults:
+            self.visit(n, parent)
+        scope = LambdaScope(self.module, self.klass)
+        if parent.nested or isinstance(parent, FunctionScope):
+            scope.nested = 1
+        self.scopes[node] = scope
+        self._do_args(scope, node.argnames)
+        self.visit(node.code, scope)
+        self.handle_free_vars(scope, parent)
+
+    def _do_args(self, scope, args):
+        for name in args:
+            if type(name) == types.TupleType:
+                self._do_args(scope, name)
+            else:
+                scope.add_param(name)
+
+    def handle_free_vars(self, scope, parent):
+        parent.add_child(scope)
+        scope.handle_children()
+
+    def visitClass(self, node, parent):
+        parent.add_def(node.name)
+        for n in node.bases:
+            self.visit(n, parent)
+        scope = ClassScope(node.name, self.module)
+        if parent.nested or isinstance(parent, FunctionScope):
+            scope.nested = 1
+        if node.doc is not None:
+            scope.add_def('__doc__')
+        scope.add_def('__module__')
+        self.scopes[node] = scope
+        prev = self.klass
+        self.klass = node.name
+        self.visit(node.code, scope)
+        self.klass = prev
+        self.handle_free_vars(scope, parent)
+
+    # name can be a def or a use
+
+    # XXX a few calls and nodes expect a third "assign" arg that is
+    # true if the name is being used as an assignment.  only
+    # expressions contained within statements may have the assign arg.
+
+    def visitName(self, node, scope, assign=0):
+        if assign:
+            scope.add_def(node.name)
+        else:
+            scope.add_use(node.name)
+
+    # operations that bind new names
+
+    def visitFor(self, node, scope):
+        self.visit(node.assign, scope, 1)
+        self.visit(node.list, scope)
+        self.visit(node.body, scope)
+        if node.else_:
+            self.visit(node.else_, scope)
+
+    def visitFrom(self, node, scope):
+        for name, asname in node.names:
+            if name == "*":
+                continue
+            scope.add_def(asname or name)
+
+    def visitImport(self, node, scope):
+        for name, asname in node.names:
+            i = name.find(".")
+            if i > -1:
+                name = name[:i]
+            scope.add_def(asname or name)
+
+    def visitGlobal(self, node, scope):
+        for name in node.names:
+            scope.add_global(name)
+
+    def visitAssign(self, node, scope):
+        """Propagate assignment flag down to child nodes.
+
+        The Assign node doesn't itself contains the variables being
+        assigned to.  Instead, the children in node.nodes are visited
+        with the assign flag set to true.  When the names occur in
+        those nodes, they are marked as defs.
+
+        Some names that occur in an assignment target are not bound by
+        the assignment, e.g. a name occurring inside a slice.  The
+        visitor handles these nodes specially; they do not propagate
+        the assign flag to their children.
+        """
+        for n in node.nodes:
+            self.visit(n, scope, 1)
+        self.visit(node.expr, scope)
+
+    def visitAssName(self, node, scope, assign=1):
+        scope.add_def(node.name)
+
+    def visitAssAttr(self, node, scope, assign=0):
+        self.visit(node.expr, scope, 0)
+
+    def visitSubscript(self, node, scope, assign=0):
+        self.visit(node.expr, scope, 0)
+        for n in node.subs:
+            self.visit(n, scope, 0)
+
+    def visitSlice(self, node, scope, assign=0):
+        self.visit(node.expr, scope, 0)
+        if node.lower:
+            self.visit(node.lower, scope, 0)
+        if node.upper:
+            self.visit(node.upper, scope, 0)
+
+    def visitAugAssign(self, node, scope):
+        # If the LHS is a name, then this counts as assignment.
+        # Otherwise, it's just use.
+        self.visit(node.node, scope)
+        if isinstance(node.node, ast.Name):
+            self.visit(node.node, scope, 1) # XXX worry about this
+        self.visit(node.expr, scope)
+
+    # prune if statements if tests are false
+
+    _const_types = types.StringType, types.IntType, types.FloatType
+
+    def visitIf(self, node, scope):
+        for test, body in node.tests:
+            if isinstance(test, ast.Const):
+                if type(test.value) in self._const_types:
+                    if not test.value:
+                        continue
+            self.visit(test, scope)
+            self.visit(body, scope)
+        if node.else_:
+            self.visit(node.else_, scope)
+
+    # a yield statement signals a generator
+
+    def visitYield(self, node, scope):
+        scope.generator = 1
+        self.visit(node.value, scope)
+
+def list_eq(l1, l2):
+    return sorted(l1) == sorted(l2)
+
+if __name__ == "__main__":
+    import sys
+    from compiler import parseFile, walk
+    import symtable
+
+    def get_names(syms):
+        return [s for s in [s.get_name() for s in syms.get_symbols()]
+                if not (s.startswith('_[') or s.startswith('.'))]
+
+    for file in sys.argv[1:]:
+        print file
+        f = open(file)
+        buf = f.read()
+        f.close()
+        syms = symtable.symtable(buf, file, "exec")
+        mod_names = get_names(syms)
+        tree = parseFile(file)
+        s = SymbolVisitor()
+        walk(tree, s)
+
+        # compare module-level symbols
+        names2 = s.scopes[tree].get_names()
+
+        if not list_eq(mod_names, names2):
+            print
+            print "oops", file
+            print sorted(mod_names)
+            print sorted(names2)
+            sys.exit(-1)
+
+        d = {}
+        d.update(s.scopes)
+        del d[tree]
+        scopes = d.values()
+        del d
+
+        for s in syms.get_symbols():
+            if s.is_namespace():
+                l = [sc for sc in scopes
+                     if sc.name == s.get_name()]
+                if len(l) > 1:
+                    print "skipping", s.get_name()
+                else:
+                    if not list_eq(get_names(s.get_namespace()),
+                                   l[0].get_names()):
+                        print s.get_name()
+                        print sorted(get_names(s.get_namespace()))
+                        print sorted(l[0].get_names())
+                        sys.exit(-1)
diff -r 000000000000 -r 7bec0014e871 compiler/syntax.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/compiler/syntax.py	Fri May 18 20:51:41 2012 +0200
@@ -0,0 +1,46 @@
+"""Check for errs in the AST.
+
+The Python parser does not catch all syntax errors.  Others, like
+assignments with invalid targets, are caught in the code generation
+phase.
+
+The compiler package catches some errors in the transformer module.
+But it seems clearer to write checkers that use the AST to detect
+errors.
+"""
+
+from compiler import ast, walk
+
+def check(tree, multi=None):
+    v = SyntaxErrorChecker(multi)
+    walk(tree, v)
+    return v.errors
+
+class SyntaxErrorChecker:
+    """A visitor to find syntax errors in the AST."""
+
+    def __init__(self, multi=None):
+        """Create new visitor object.
+
+        If optional argument multi is not None, then print messages
+        for each error rather than raising a SyntaxError for the
+        first.
+        """
+        self.multi = multi
+        self.errors = 0
+
+    def error(self, node, msg):
+        self.errors = self.errors + 1
+        if self.multi is not None:
+            print "%s:%s: %s" % (node.filename, node.lineno, msg)
+        else:
+            raise SyntaxError, "%s (%s:%s)" % (msg, node.filename, node.lineno)
+
+    def visitAssign(self, node):
+        # the transformer module handles many of these
+        pass
+##        for target in node.nodes:
+##            if isinstance(target, ast.AssList):
+##                if target.lineno is None:
+##                    target.lineno = node.lineno
+##                self.error(target, "can't assign to list comprehension")
diff -r 000000000000 -r 7bec0014e871 compiler/transformer.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/compiler/transformer.py	Fri May 18 20:51:41 2012 +0200
@@ -0,0 +1,1499 @@
+"""Parse tree transformation module.
+
+Transforms Python source code into an abstract syntax tree (AST)
+defined in the ast module.
+
+The simplest ways to invoke this module are via parse and parseFile.
+parse(buf) -> AST
+parseFile(path) -> AST
+"""
+
+# Original version written by Greg Stein (gstein@lyra.org)
+#                         and Bill Tutt (rassilon@lima.mudlib.org)
+# February 1997.
+#
+# Modifications and improvements for Python 2.0 by Jeremy Hylton and
+# Mark Hammond
+#
+# Some fixes to try to have correct line number on almost all nodes
+# (except Module, Discard and Stmt) added by Sylvain Thenault
+#
+# Portions of this file are:
+# Copyright (C) 1997-1998 Greg Stein. All Rights Reserved.
+#
+# This module is provided under a BSD-ish license. See
+#   http://www.opensource.org/licenses/bsd-license.html
+# and replace OWNER, ORGANIZATION, and YEAR as appropriate.
+
+from compiler.ast import *
+import parser
+import symbol
+import token
+
+class WalkerError(StandardError):
+    pass
+
+from compiler.consts import CO_VARARGS, CO_VARKEYWORDS
+from compiler.consts import OP_ASSIGN, OP_DELETE, OP_APPLY
+
+def parseFile(path):
+    f = open(path, "U")
+    # XXX The parser API tolerates files without a trailing newline,
+    # but not strings without a trailing newline.  Always add an extra
+    # newline to the file contents, since we're going through the string
+    # version of the API.
+    src = f.read() + "\n"
+    f.close()
+    return parse(src)
+
+def parse(buf, mode="exec"):
+    if mode == "exec" or mode == "single":
+        return Transformer().parsesuite(buf)
+    elif mode == "eval":
+        return Transformer().parseexpr(buf)
+    else:
+        raise ValueError("compile() arg 3 must be"
+                         " 'exec' or 'eval' or 'single'")
+
+def asList(nodes):
+    l = []
+    for item in nodes:
+        if hasattr(item, "asList"):
+            l.append(item.asList())
+        else:
+            if type(item) is type( (None, None) ):
+                l.append(tuple(asList(item)))
+            elif type(item) is type( [] ):
+                l.append(asList(item))
+            else:
+                l.append(item)
+    return l
+
+def extractLineNo(ast):
+    if not isinstance(ast[1], tuple):
+        # get a terminal node
+        return ast[2]
+    for child in ast[1:]:
+        if isinstance(child, tuple):
+            lineno = extractLineNo(child)
+            if lineno is not None:
+                return lineno
+
+def Node(*args):
+    kind = args[0]
+    if kind in nodes:
+        try:
+            return nodes[kind](*args[1:])
+        except TypeError:
+            print nodes[kind], len(args), args
+            raise
+    else:
+        raise WalkerError, "Can't find appropriate Node type: %s" % str(args)
+        #return apply(ast.Node, args)
+
+class Transformer:
+    """Utility object for transforming Python parse trees.
+
+    Exposes the following methods:
+        tree = transform(ast_tree)
+        tree = parsesuite(text)
+        tree = parseexpr(text)
+        tree = parsefile(fileob | filename)
+    """
+
+    def __init__(self):
+        self._dispatch = {}
+        for value, name in symbol.sym_name.items():
+            if hasattr(self, name):
+                self._dispatch[value] = getattr(self, name)
+        self._dispatch[token.NEWLINE] = self.com_NEWLINE
+        self._atom_dispatch = {token.LPAR: self.atom_lpar,
+                               token.LSQB: self.atom_lsqb,
+                               token.LBRACE: self.atom_lbrace,
+                               token.BACKQUOTE: self.atom_backquote,
+                               token.NUMBER: self.atom_number,
+                               token.STRING: self.atom_string,
+                               token.NAME: self.atom_name,
+                               }
+        self.encoding = None
+
+    def transform(self, tree):
+        """Transform an AST into a modified parse tree."""
+        if not (isinstance(tree, tuple) or isinstance(tree, list)):
+            tree = parser.st2tuple(tree, line_info=1)
+        return self.compile_node(tree)
+
+    def parsesuite(self, text):
+        """Return a modified parse tree for the given suite text."""
+        return self.transform(parser.suite(text))
+
+    def parseexpr(self, text):
+        """Return a modified parse tree for the given expression text."""
+        return self.transform(parser.expr(text))
+
+    def parsefile(self, file):
+        """Return a modified parse tree for the contents of the given file."""
+        if type(file) == type(''):
+            file = open(file)
+        return self.parsesuite(file.read())
+
+    # --------------------------------------------------------------
+    #
+    # PRIVATE METHODS
+    #
+
+    def compile_node(self, node):
+        ### emit a line-number node?
+        n = node[0]
+
+        if n == symbol.encoding_decl:
+            self.encoding = node[2]
+            node = node[1]
+            n = node[0]
+
+        if n == symbol.single_input:
+            return self.single_input(node[1:])
+        if n == symbol.file_input:
+            return self.file_input(node[1:])
+        if n == symbol.eval_input:
+            return self.eval_input(node[1:])
+        if n == symbol.lambdef:
+            return self.lambdef(node[1:])
+        if n == symbol.funcdef:
+            return self.funcdef(node[1:])
+        if n == symbol.classdef:
+            return self.classdef(node[1:])
+
+        raise WalkerError, ('unexpected node type', n)
+
+    def single_input(self, node):
+        ### do we want to do anything about being "interactive" ?
+
+        # NEWLINE | simple_stmt | compound_stmt NEWLINE
+        n = node[0][0]
+        if n != token.NEWLINE:
+            return self.com_stmt(node[0])
+
+        return Pass()
+
+    def file_input(self, nodelist):
+        doc = self.get_docstring(nodelist, symbol.file_input)
+        if doc is not None:
+            i = 1
+        else:
+            i = 0
+        stmts = []
+        for node in nodelist[i:]:
+            if node[0] != token.ENDMARKER and node[0] != token.NEWLINE:
+                self.com_append_stmt(stmts, node)
+        return Module(doc, Stmt(stmts))
+
+    def eval_input(self, nodelist):
+        # from the built-in function input()
+        ### is this sufficient?
+        return Expression(self.com_node(nodelist[0]))
+
+    def decorator_name(self, nodelist):
+        listlen = len(nodelist)
+        assert listlen >= 1 and listlen % 2 == 1
+
+        item = self.atom_name(nodelist)
+        i = 1
+        while i < listlen:
+            assert nodelist[i][0] == token.DOT
+            assert nodelist[i + 1][0] == token.NAME
+            item = Getattr(item, nodelist[i + 1][1])
+            i += 2
+
+        return item
+
+    def decorator(self, nodelist):
+        # '@' dotted_name [ '(' [arglist] ')' ]
+        assert len(nodelist) in (3, 5, 6)
+        assert nodelist[0][0] == token.AT
+        assert nodelist[-1][0] == token.NEWLINE
+
+        assert nodelist[1][0] == symbol.dotted_name
+        funcname = self.decorator_name(nodelist[1][1:])
+
+        if len(nodelist) > 3:
+            assert nodelist[2][0] == token.LPAR
+            expr = self.com_call_function(funcname, nodelist[3])
+        else:
+            expr = funcname
+
+        return expr
+
+    def decorators(self, nodelist):
+        # decorators: decorator ([NEWLINE] decorator)* NEWLINE
+        items = []
+        for dec_nodelist in nodelist:
+            assert dec_nodelist[0] == symbol.decorator
+            items.append(self.decorator(dec_nodelist[1:]))
+        return Decorators(items)
+
+    def decorated(self, nodelist):
+        assert nodelist[0][0] == symbol.decorators
+        if nodelist[1][0] == symbol.funcdef:
+            n = [nodelist[0]] + list(nodelist[1][1:])
+            return self.funcdef(n)
+        elif nodelist[1][0] == symbol.classdef:
+            decorators = self.decorators(nodelist[0][1:])
+            cls = self.classdef(nodelist[1][1:])
+            cls.decorators = decorators
+            return cls
+        raise WalkerError()
+
+    def funcdef(self, nodelist):
+        #                    -6   -5    -4         -3  -2    -1
+        # funcdef: [decorators] 'def' NAME parameters ':' suite
+        # parameters: '(' [varargslist] ')'
+
+        if len(nodelist) == 6:
+            assert nodelist[0][0] == symbol.decorators
+            decorators = self.decorators(nodelist[0][1:])
+        else:
+            assert len(nodelist) == 5
+            decorators = None
+
+        lineno = nodelist[-4][2]
+        name = nodelist[-4][1]
+        args = nodelist[-3][2]
+
+        if args[0] == symbol.varargslist:
+            names, defaults, flags = self.com_arglist(args[1:])
+        else:
+            names = defaults = ()
+            flags = 0
+        doc = self.get_docstring(nodelist[-1])
+
+        # code for function
+        code = self.com_node(nodelist[-1])
+
+        if doc is not None:
+            assert isinstance(code, Stmt)
+            assert isinstance(code.nodes[0], Discard)
+            del code.nodes[0]
+        return Function(decorators, name, names, defaults, flags, doc, code,
+                     lineno=lineno)
+
+    def lambdef(self, nodelist):
+        # lambdef: 'lambda' [varargslist] ':' test
+        if nodelist[2][0] == symbol.varargslist:
+            names, defaults, flags = self.com_arglist(nodelist[2][1:])
+        else:
+            names = defaults = ()
+            flags = 0
+
+        # code for lambda
+        code = self.com_node(nodelist[-1])
+
+        return Lambda(names, defaults, flags, code, lineno=nodelist[1][2])
+    old_lambdef = lambdef
+
+    def classdef(self, nodelist):
+        # classdef: 'class' NAME ['(' [testlist] ')'] ':' suite
+
+        name = nodelist[1][1]
+        doc = self.get_docstring(nodelist[-1])
+        if nodelist[2][0] == token.COLON:
+            bases = []
+        elif nodelist[3][0] == token.RPAR:
+            bases = []
+        else:
+            bases = self.com_bases(nodelist[3])
+
+        # code for class
+        code = self.com_node(nodelist[-1])
+
+        if doc is not None:
+            assert isinstance(code, Stmt)
+            assert isinstance(code.nodes[0], Discard)
+            del code.nodes[0]
+
+        return Class(name, bases, doc, code, lineno=nodelist[1][2])
+
+    def stmt(self, nodelist):
+        return self.com_stmt(nodelist[0])
+
+    small_stmt = stmt
+    flow_stmt = stmt
+    compound_stmt = stmt
+
+    def simple_stmt(self, nodelist):
+        # small_stmt (';' small_stmt)* [';'] NEWLINE
+        stmts = []
+        for i in range(0, len(nodelist), 2):
+            self.com_append_stmt(stmts, nodelist[i])
+        return Stmt(stmts)
+
+    def parameters(self, nodelist):
+        raise WalkerError
+
+    def varargslist(self, nodelist):
+        raise WalkerError
+
+    def fpdef(self, nodelist):
+        raise WalkerError
+
+    def fplist(self, nodelist):
+        raise WalkerError
+
+    def dotted_name(self, nodelist):
+        raise WalkerError
+
+    def comp_op(self, nodelist):
+        raise WalkerError
+
+    def trailer(self, nodelist):
+        raise WalkerError
+
+    def sliceop(self, nodelist):
+        raise WalkerError
+
+    def argument(self, nodelist):
+        raise WalkerError
+
+    # --------------------------------------------------------------
+    #
+    # STATEMENT NODES  (invoked by com_node())
+    #
+
+    def expr_stmt(self, nodelist):
+        # augassign testlist | testlist ('=' testlist)*
+        en = nodelist[-1]
+        exprNode = self.lookup_node(en)(en[1:])
+        if len(nodelist) == 1:
+            return Discard(exprNode, lineno=exprNode.lineno)
+        if nodelist[1][0] == token.EQUAL:
+            nodesl = []
+            for i in range(0, len(nodelist) - 2, 2):
+                nodesl.append(self.com_assign(nodelist[i], OP_ASSIGN))
+            return Assign(nodesl, exprNode, lineno=nodelist[1][2])
+        else:
+            lval = self.com_augassign(nodelist[0])
+            op = self.com_augassign_op(nodelist[1])
+            return AugAssign(lval, op[1], exprNode, lineno=op[2])
+        raise WalkerError, "can't get here"
+
+    def print_stmt(self, nodelist):
+        # print ([ test (',' test)* [','] ] | '>>' test [ (',' test)+ [','] ])
+        items = []
+        if len(nodelist) == 1:
+            start = 1
+            dest = None
+        elif nodelist[1][0] == token.RIGHTSHIFT:
+            assert len(nodelist) == 3 \
+                   or nodelist[3][0] == token.COMMA
+            dest = self.com_node(nodelist[2])
+            start = 4
+        else:
+            dest = None
+            start = 1
+        for i in range(start, len(nodelist), 2):
+            items.append(self.com_node(nodelist[i]))
+        if nodelist[-1][0] == token.COMMA:
+            return Print(items, dest, lineno=nodelist[0][2])
+        return Printnl(items, dest, lineno=nodelist[0][2])
+
+    def del_stmt(self, nodelist):
+        return self.com_assign(nodelist[1], OP_DELETE)
+
+    def pass_stmt(self, nodelist):
+        return Pass(lineno=nodelist[0][2])
+
+    def break_stmt(self, nodelist):
+        return Break(lineno=nodelist[0][2])
+
+    def continue_stmt(self, nodelist):
+        return Continue(lineno=nodelist[0][2])
+
+    def return_stmt(self, nodelist):
+        # return: [testlist]
+        if len(nodelist) < 2:
+            return Return(Const(None), lineno=nodelist[0][2])
+        return Return(self.com_node(nodelist[1]), lineno=nodelist[0][2])
+
+    def yield_stmt(self, nodelist):
+        expr = self.com_node(nodelist[0])
+        return Discard(expr, lineno=expr.lineno)
+
+    def yield_expr(self, nodelist):
+        if len(nodelist) > 1:
+            value = self.com_node(nodelist[1])
+        else:
+            value = Const(None)
+        return Yield(value, lineno=nodelist[0][2])
+
+    def raise_stmt(self, nodelist):
+        # raise: [test [',' test [',' test]]]
+        if len(nodelist) > 5:
+            expr3 = self.com_node(nodelist[5])
+        else:
+            expr3 = None
+        if len(nodelist) > 3:
+            expr2 = self.com_node(nodelist[3])
+        else:
+            expr2 = None
+        if len(nodelist) > 1:
+            expr1 = self.com_node(nodelist[1])
+        else:
+            expr1 = None
+        return Raise(expr1, expr2, expr3, lineno=nodelist[0][2])
+
+    def import_stmt(self, nodelist):
+        # import_stmt: import_name | import_from
+        assert len(nodelist) == 1
+        return self.com_node(nodelist[0])
+
+    def import_name(self, nodelist):
+        # import_name: 'import' dotted_as_names
+        return Import(self.com_dotted_as_names(nodelist[1]),
+                      lineno=nodelist[0][2])
+
+    def import_from(self, nodelist):
+        # import_from: 'from' ('.'* dotted_name | '.') 'import' ('*' |
+        #    '(' import_as_names ')' | import_as_names)
+        assert nodelist[0][1] == 'from'
+        idx = 1
+        while nodelist[idx][1] == '.':
+            idx += 1
+        level = idx - 1
+        if nodelist[idx][0] == symbol.dotted_name:
+            fromname = self.com_dotted_name(nodelist[idx])
+            idx += 1
+        else:
+            fromname = ""
+        assert nodelist[idx][1] == 'import'
+        if nodelist[idx + 1][0] == token.STAR:
+            return From(fromname, [('*', None)], level,
+                        lineno=nodelist[0][2])
+        else:
+            node = nodelist[idx + 1 + (nodelist[idx + 1][0] == token.LPAR)]
+            return From(fromname, self.com_import_as_names(node), level,
+                        lineno=nodelist[0][2])
+
+    def global_stmt(self, nodelist):
+        # global: NAME (',' NAME)*
+        names = []
+        for i in range(1, len(nodelist), 2):
+            names.append(nodelist[i][1])
+        return Global(names, lineno=nodelist[0][2])
+
+    def exec_stmt(self, nodelist):
+        # exec_stmt: 'exec' expr ['in' expr [',' expr]]
+        expr1 = self.com_node(nodelist[1])
+        if len(nodelist) >= 4:
+            expr2 = self.com_node(nodelist[3])
+            if len(nodelist) >= 6:
+                expr3 = self.com_node(nodelist[5])
+            else:
+                expr3 = None
+        else:
+            expr2 = expr3 = None
+
+        return Exec(expr1, expr2, expr3, lineno=nodelist[0][2])
+
+    def assert_stmt(self, nodelist):
+        # 'assert': test, [',' test]
+        expr1 = self.com_node(nodelist[1])
+        if (len(nodelist) == 4):
+            expr2 = self.com_node(nodelist[3])
+        else:
+            expr2 = None
+        return Assert(expr1, expr2, lineno=nodelist[0][2])
+
+    def if_stmt(self, nodelist):
+        # if: test ':' suite ('elif' test ':' suite)* ['else' ':' suite]
+        tests = []
+        for i in range(0, len(nodelist) - 3, 4):
+            testNode = self.com_node(nodelist[i + 1])
+            suiteNode = self.com_node(nodelist[i + 3])
+            tests.append((testNode, suiteNode))
+
+        if len(nodelist) % 4 == 3:
+            elseNode = self.com_node(nodelist[-1])
+##      elseNode.lineno = nodelist[-1][1][2]
+        else:
+            elseNode = None
+        return If(tests, elseNode, lineno=nodelist[0][2])
+
+    def while_stmt(self, nodelist):
+        # 'while' test ':' suite ['else' ':' suite]
+
+        testNode = self.com_node(nodelist[1])
+        bodyNode = self.com_node(nodelist[3])
+
+        if len(nodelist) > 4:
+            elseNode = self.com_node(nodelist[6])
+        else:
+            elseNode = None
+
+        return While(testNode, bodyNode, elseNode, lineno=nodelist[0][2])
+
+    def for_stmt(self, nodelist):
+        # 'for' exprlist 'in' exprlist ':' suite ['else' ':' suite]
+
+        assignNode = self.com_assign(nodelist[1], OP_ASSIGN)
+        listNode = self.com_node(nodelist[3])
+        bodyNode = self.com_node(nodelist[5])
+
+        if len(nodelist) > 8:
+            elseNode = self.com_node(nodelist[8])
+        else:
+            elseNode = None
+
+        return For(assignNode, listNode, bodyNode, elseNode,
+                   lineno=nodelist[0][2])
+
+    def try_stmt(self, nodelist):
+        return self.com_try_except_finally(nodelist)
+
+    def with_stmt(self, nodelist):
+        return self.com_with(nodelist)
+
+    def with_var(self, nodelist):
+        return self.com_with_var(nodelist)
+
+    def suite(self, nodelist):
+        # simple_stmt | NEWLINE INDENT NEWLINE* (stmt NEWLINE*)+ DEDENT
+        if len(nodelist) == 1:
+            return self.com_stmt(nodelist[0])
+
+        stmts = []
+        for node in nodelist:
+            if node[0] == symbol.stmt:
+                self.com_append_stmt(stmts, node)
+        return Stmt(stmts)
+
+    # --------------------------------------------------------------
+    #
+    # EXPRESSION NODES  (invoked by com_node())
+    #
+
+    def testlist(self, nodelist):
+        # testlist: expr (',' expr)* [',']
+        # testlist_safe: test [(',' test)+ [',']]
+        # exprlist: expr (',' expr)* [',']
+        return self.com_binary(Tuple, nodelist)
+
+    testlist_safe = testlist # XXX
+    testlist1 = testlist
+    exprlist = testlist
+
+    def testlist_gexp(self, nodelist):
+        if len(nodelist) == 2 and nodelist[1][0] == symbol.gen_for:
+            test = self.com_node(nodelist[0])
+            return self.com_generator_expression(test, nodelist[1])
+        return self.testlist(nodelist)
+
+    def test(self, nodelist):
+        # or_test ['if' or_test 'else' test] | lambdef
+        if len(nodelist) == 1 and nodelist[0][0] == symbol.lambdef:
+            return self.lambdef(nodelist[0])
+        then = self.com_node(nodelist[0])
+        if len(nodelist) > 1:
+            assert len(nodelist) == 5
+            assert nodelist[1][1] == 'if'
+            assert nodelist[3][1] == 'else'
+            test = self.com_node(nodelist[2])
+            else_ = self.com_node(nodelist[4])
+            return IfExp(test, then, else_, lineno=nodelist[1][2])
+        return then
+
+    def or_test(self, nodelist):
+        # and_test ('or' and_test)* | lambdef
+        if len(nodelist) == 1 and nodelist[0][0] == symbol.lambdef:
+            return self.lambdef(nodelist[0])
+        return self.com_binary(Or, nodelist)
+    old_test = or_test
+
+    def and_test(self, nodelist):
+        # not_test ('and' not_test)*
+        return self.com_binary(And, nodelist)
+
+    def not_test(self, nodelist):
+        # 'not' not_test | comparison
+        result = self.com_node(nodelist[-1])
+        if len(nodelist) == 2:
+            return Not(result, lineno=nodelist[0][2])
+        return result
+
+    def comparison(self, nodelist):
+        # comparison: expr (comp_op expr)*
+        node = self.com_node(nodelist[0])
+        if len(nodelist) == 1:
+            return node
+
+        results = []
+        for i in range(2, len(nodelist), 2):
+            nl = nodelist[i-1]
+
+            # comp_op: '<' | '>' | '=' | '>=' | '<=' | '<>' | '!=' | '=='
+            #          | 'in' | 'not' 'in' | 'is' | 'is' 'not'
+            n = nl[1]
+            if n[0] == token.NAME:
+                type = n[1]
+                if len(nl) == 3:
+                    if type == 'not':
+                        type = 'not in'
+                    else:
+                        type = 'is not'
+            else:
+                type = _cmp_types[n[0]]
+
+            lineno = nl[1][2]
+            results.append((type, self.com_node(nodelist[i])))
+
+        # we need a special "compare" node so that we can distinguish
+        #   3 < x < 5   from    (3 < x) < 5
+        # the two have very different semantics and results (note that the
+        # latter form is always true)
+
+        return Compare(node, results, lineno=lineno)
+
+    def expr(self, nodelist):
+        # xor_expr ('|' xor_expr)*
+        return self.com_binary(Bitor, nodelist)
+
+    def xor_expr(self, nodelist):
+        # xor_expr ('^' xor_expr)*
+        return self.com_binary(Bitxor, nodelist)
+
+    def and_expr(self, nodelist):
+        # xor_expr ('&' xor_expr)*
+        return self.com_binary(Bitand, nodelist)
+
+    def shift_expr(self, nodelist):
+        # shift_expr ('<<'|'>>' shift_expr)*
+        node = self.com_node(nodelist[0])
+        for i in range(2, len(nodelist), 2):
+            right = self.com_node(nodelist[i])
+            if nodelist[i-1][0] == token.LEFTSHIFT:
+                node = LeftShift([node, right], lineno=nodelist[1][2])
+            elif nodelist[i-1][0] == token.RIGHTSHIFT:
+                node = RightShift([node, right], lineno=nodelist[1][2])
+            else:
+                raise ValueError, "unexpected token: %s" % nodelist[i-1][0]
+        return node
+
+    def arith_expr(self, nodelist):
+        node = self.com_node(nodelist[0])
+        for i in range(2, len(nodelist), 2):
+            right = self.com_node(nodelist[i])
+            if nodelist[i-1][0] == token.PLUS:
+                node = Add([node, right], lineno=nodelist[1][2])
+            elif nodelist[i-1][0] == token.MINUS:
+                node = Sub([node, right], lineno=nodelist[1][2])
+            else:
+                raise ValueError, "unexpected token: %s" % nodelist[i-1][0]
+        return node
+
+    def term(self, nodelist):
+        node = self.com_node(nodelist[0])
+        for i in range(2, len(nodelist), 2):
+            right = self.com_node(nodelist[i])
+            t = nodelist[i-1][0]
+            if t == token.STAR:
+                node = Mul([node, right])
+            elif t == token.SLASH:
+                node = Div([node, right])
+            elif t == token.PERCENT:
+                node = Mod([node, right])
+            elif t == token.DOUBLESLASH:
+                node = FloorDiv([node, right])
+            else:
+                raise ValueError, "unexpected token: %s" % t
+            node.lineno = nodelist[1][2]
+        return node
+
+    def factor(self, nodelist):
+        elt = nodelist[0]
+        t = elt[0]
+        node = self.lookup_node(nodelist[-1])(nodelist[-1][1:])
+        # need to handle (unary op)constant here...
+        if t == token.PLUS:
+            return UnaryAdd(node, lineno=elt[2])
+        elif t == token.MINUS:
+            return UnarySub(node, lineno=elt[2])
+        elif t == token.TILDE:
+            node = Invert(node, lineno=elt[2])
+        return node
+
+    def power(self, nodelist):
+        # power: atom trailer* ('**' factor)*
+        node = self.com_node(nodelist[0])
+        for i in range(1, len(nodelist)):
+            elt = nodelist[i]
+            if elt[0] == token.DOUBLESTAR:
+                return Power([node, self.com_node(nodelist[i+1])],
+                             lineno=elt[2])
+
+            node = self.com_apply_trailer(node, elt)
+
+        return node
+
+    def atom(self, nodelist):
+        return self._atom_dispatch[nodelist[0][0]](nodelist)
+
+    def atom_lpar(self, nodelist):
+        if nodelist[1][0] == token.RPAR:
+            return Tuple((), lineno=nodelist[0][2])
+        return self.com_node(nodelist[1])
+
+    def atom_lsqb(self, nodelist):
+        if nodelist[1][0] == token.RSQB:
+            return List((), lineno=nodelist[0][2])
+        return self.com_list_constructor(nodelist[1])
+
+    def atom_lbrace(self, nodelist):
+        if nodelist[1][0] == token.RBRACE:
+            return Dict((), lineno=nodelist[0][2])
+        return self.com_dictmaker(nodelist[1])
+
+    def atom_backquote(self, nodelist):
+        return Backquote(self.com_node(nodelist[1]))
+
+    def atom_number(self, nodelist):
+        ### need to verify this matches compile.c
+        k = eval(nodelist[0][1])
+        return Const(k, lineno=nodelist[0][2])
+
+    def decode_literal(self, lit):
+        if self.encoding:
+            # this is particularly fragile & a bit of a
+            # hack... changes in compile.c:parsestr and
+            # tokenizer.c must be reflected here.
+            if self.encoding not in ['utf-8', 'iso-8859-1']:
+                lit = unicode(lit, 'utf-8').encode(self.encoding)
+            return eval("# coding: %s\n%s" % (self.encoding, lit))
+        else:
+            return eval(lit)
+
+    def atom_string(self, nodelist):
+        k = ''
+        for node in nodelist:
+            k += self.decode_literal(node[1])
+        return Const(k, lineno=nodelist[0][2])
+
+    def atom_name(self, nodelist):
+        return Name(nodelist[0][1], lineno=nodelist[0][2])
+
+    # --------------------------------------------------------------
+    #
+    # INTERNAL PARSING UTILITIES
+    #
+
+    # The use of com_node() introduces a lot of extra stack frames,
+    # enough to cause a stack overflow compiling test.test_parser with
+    # the standard interpreter recursionlimit.  The com_node() is a
+    # convenience function that hides the dispatch details, but comes
+    # at a very high cost.  It is more efficient to dispatch directly
+    # in the callers.  In these cases, use lookup_node() and call the
+    # dispatched node directly.
+
+    def lookup_node(self, node):
+        return self._dispatch[node[0]]
+
+    def com_node(self, node):
+        # Note: compile.c has handling in com_node for del_stmt, pass_stmt,
+        #       break_stmt, stmt, small_stmt, flow_stmt, simple_stmt,
+        #       and compound_stmt.
+        #       We'll just dispatch them.
+        return self._dispatch[node[0]](node[1:])
+
+    def com_NEWLINE(self, *args):
+        # A ';' at the end of a line can make a NEWLINE token appear
+        # here, Render it harmless. (genc discards ('discard',
+        # ('const', xxxx)) Nodes)
+        return Discard(Const(None))
+
+    def com_arglist(self, nodelist):
+        # varargslist:
+        #     (fpdef ['=' test] ',')* ('*' NAME [',' '**' NAME] | '**' NAME)
+        #   | fpdef ['=' test] (',' fpdef ['=' test])* [',']
+        # fpdef: NAME | '(' fplist ')'
+        # fplist: fpdef (',' fpdef)* [',']
+        names = []
+        defaults = []
+        flags = 0
+
+        i = 0
+        while i < len(nodelist):
+            node = nodelist[i]
+            if node[0] == token.STAR or node[0] == token.DOUBLESTAR:
+                if node[0] == token.STAR:
+                    node = nodelist[i+1]
+                    if node[0] == token.NAME:
+                        names.append(node[1])
+                        flags = flags | CO_VARARGS
+                        i = i + 3
+
+                if i < len(nodelist):
+                    # should be DOUBLESTAR
+                    t = nodelist[i][0]
+                    if t == token.DOUBLESTAR:
+                        node = nodelist[i+1]
+                    else:
+                        raise ValueError, "unexpected token: %s" % t
+                    names.append(node[1])
+                    flags = flags | CO_VARKEYWORDS
+
+                break
+
+            # fpdef: NAME | '(' fplist ')'
+            names.append(self.com_fpdef(node))
+
+            i = i + 1
+            if i < len(nodelist) and nodelist[i][0] == token.EQUAL:
+                defaults.append(self.com_node(nodelist[i + 1]))
+                i = i + 2
+            elif len(defaults):
+                # we have already seen an argument with default, but here
+                # came one without
+                raise SyntaxError, "non-default argument follows default argument"
+
+            # skip the comma
+            i = i + 1
+
+        return names, defaults, flags
+
+    def com_fpdef(self, node):
+        # fpdef: NAME | '(' fplist ')'
+        if node[1][0] == token.LPAR:
+            return self.com_fplist(node[2])
+        return node[1][1]
+
+    def com_fplist(self, node):
+        # fplist: fpdef (',' fpdef)* [',']
+        if len(node) == 2:
+            return self.com_fpdef(node[1])
+        list = []
+        for i in range(1, len(node), 2):
+            list.append(self.com_fpdef(node[i]))
+        return tuple(list)
+
+    def com_dotted_name(self, node):
+        # String together the dotted names and return the string
+        name = ""
+        for n in node:
+            if type(n) == type(()) and n[0] == 1:
+                name = name + n[1] + '.'
+        return name[:-1]
+
+    def com_dotted_as_name(self, node):
+        assert node[0] == symbol.dotted_as_name
+        node = node[1:]
+        dot = self.com_dotted_name(node[0][1:])
+        if len(node) == 1:
+            return dot, None
+        assert node[1][1] == 'as'
+        assert node[2][0] == token.NAME
+        return dot, node[2][1]
+
+    def com_dotted_as_names(self, node):
+        assert node[0] == symbol.dotted_as_names
+        node = node[1:]
+        names = [self.com_dotted_as_name(node[0])]
+        for i in range(2, len(node), 2):
+            names.append(self.com_dotted_as_name(node[i]))
+        return names
+
+    def com_import_as_name(self, node):
+        assert node[0] == symbol.import_as_name
+        node = node[1:]
+        assert node[0][0] == token.NAME
+        if len(node) == 1:
+            return node[0][1], None
+        assert node[1][1] == 'as', node
+        assert node[2][0] == token.NAME
+        return node[0][1], node[2][1]
+
+    def com_import_as_names(self, node):
+        assert node[0] == symbol.import_as_names
+        node = node[1:]
+        names = [self.com_import_as_name(node[0])]
+        for i in range(2, len(node), 2):
+            names.append(self.com_import_as_name(node[i]))
+        return names
+
+    def com_bases(self, node):
+        bases = []
+        for i in range(1, len(node), 2):
+            bases.append(self.com_node(node[i]))
+        return bases
+
+    def com_try_except_finally(self, nodelist):
+        # ('try' ':' suite
+        #  ((except_clause ':' suite)+ ['else' ':' suite] ['finally' ':' suite]
+        #   | 'finally' ':' suite))
+
+        if nodelist[3][0] == token.NAME:
+            # first clause is a finally clause: only try-finally
+            return TryFinally(self.com_node(nodelist[2]),
+                              self.com_node(nodelist[5]),
+                              lineno=nodelist[0][2])
+
+        #tryexcept:  [TryNode, [except_clauses], elseNode)]
+        clauses = []
+        elseNode = None
+        finallyNode = None
+        for i in range(3, len(nodelist), 3):
+            node = nodelist[i]
+            if node[0] == symbol.except_clause:
+                # except_clause: 'except' [expr [(',' | 'as') expr]] */
+                if len(node) > 2:
+                    expr1 = self.com_node(node[2])
+                    if len(node) > 4:
+                        expr2 = self.com_assign(node[4], OP_ASSIGN)
+                    else:
+                        expr2 = None
+                else:
+                    expr1 = expr2 = None
+                clauses.append((expr1, expr2, self.com_node(nodelist[i+2])))
+
+            if node[0] == token.NAME:
+                if node[1] == 'else':
+                    elseNode = self.com_node(nodelist[i+2])
+                elif node[1] == 'finally':
+                    finallyNode = self.com_node(nodelist[i+2])
+        try_except = TryExcept(self.com_node(nodelist[2]), clauses, elseNode,
+                               lineno=nodelist[0][2])
+        if finallyNode:
+            return TryFinally(try_except, finallyNode, lineno=nodelist[0][2])
+        else:
+            return try_except
+
+    def com_with(self, nodelist):
+        # with_stmt: 'with' expr [with_var] ':' suite
+        expr = self.com_node(nodelist[1])
+        body = self.com_node(nodelist[-1])
+        if nodelist[2][0] == token.COLON:
+            var = None
+        else:
+            var = self.com_assign(nodelist[2][2], OP_ASSIGN)
+        return With(expr, var, body, lineno=nodelist[0][2])
+
+    def com_with_var(self, nodelist):
+        # with_var: 'as' expr
+        return self.com_node(nodelist[1])
+
+    def com_augassign_op(self, node):
+        assert node[0] == symbol.augassign
+        return node[1]
+
+    def com_augassign(self, node):
+        """Return node suitable for lvalue of augmented assignment
+
+        Names, slices, and attributes are the only allowable nodes.
+        """
+        l = self.com_node(node)
+        if l.__class__ in (Name, Slice, Subscript, Getattr):
+            return l
+        raise SyntaxError, "can't assign to %s" % l.__class__.__name__
+
+    def com_assign(self, node, assigning):
+        # return a node suitable for use as an "lvalue"
+        # loop to avoid trivial recursion
+        while 1:
+            t = node[0]
+            if t in (symbol.exprlist, symbol.testlist, symbol.testlist_safe, symbol.testlist_gexp):
+                if len(node) > 2:
+                    return self.com_assign_tuple(node, assigning)
+                node = node[1]
+            elif t in _assign_types:
+                if len(node) > 2:
+                    raise SyntaxError, "can't assign to operator"
+                node = node[1]
+            elif t == symbol.power:
+                if node[1][0] != symbol.atom:
+                    raise SyntaxError, "can't assign to operator"
+                if len(node) > 2:
+                    primary = self.com_node(node[1])
+                    for i in range(2, len(node)-1):
+                        ch = node[i]
+                        if ch[0] == token.DOUBLESTAR:
+                            raise SyntaxError, "can't assign to operator"
+                        primary = self.com_apply_trailer(primary, ch)
+                    return self.com_assign_trailer(primary, node[-1],
+                                                   assigning)
+                node = node[1]
+            elif t == symbol.atom:
+                t = node[1][0]
+                if t == token.LPAR:
+                    node = node[2]
+                    if node[0] == token.RPAR:
+                        raise SyntaxError, "can't assign to ()"
+                elif t == token.LSQB:
+                    node = node[2]
+                    if node[0] == token.RSQB:
+                        raise SyntaxError, "can't assign to []"
+                    return self.com_assign_list(node, assigning)
+                elif t == token.NAME:
+                    return self.com_assign_name(node[1], assigning)
+                else:
+                    raise SyntaxError, "can't assign to literal"
+            else:
+                raise SyntaxError, "bad assignment (%s)" % t
+
+    def com_assign_tuple(self, node, assigning):
+        assigns = []
+        for i in range(1, len(node), 2):
+            assigns.append(self.com_assign(node[i], assigning))
+        return AssTuple(assigns, lineno=extractLineNo(node))
+
+    def com_assign_list(self, node, assigning):
+        assigns = []
+        for i in range(1, len(node), 2):
+            if i + 1 < len(node):
+                if node[i + 1][0] == symbol.list_for:
+                    raise SyntaxError, "can't assign to list comprehension"
+                assert node[i + 1][0] == token.COMMA, node[i + 1]
+            assigns.append(self.com_assign(node[i], assigning))
+        return AssList(assigns, lineno=extractLineNo(node))
+
+    def com_assign_name(self, node, assigning):
+        return AssName(node[1], assigning, lineno=node[2])
+
+    def com_assign_trailer(self, primary, node, assigning):
+        t = node[1][0]
+        if t == token.DOT:
+            return self.com_assign_attr(primary, node[2], assigning)
+        if t == token.LSQB:
+            return self.com_subscriptlist(primary, node[2], assigning)
+        if t == token.LPAR:
+            raise SyntaxError, "can't assign to function call"
+        raise SyntaxError, "unknown trailer type: %s" % t
+
+    def com_assign_attr(self, primary, node, assigning):
+        return AssAttr(primary, node[1], assigning, lineno=node[-1])
+
+    def com_binary(self, constructor, nodelist):
+        "Compile 'NODE (OP NODE)*' into (type, [ node1, ..., nodeN ])."
+        l = len(nodelist)
+        if l == 1:
+            n = nodelist[0]
+            return self.lookup_node(n)(n[1:])
+        items = []
+        for i in range(0, l, 2):
+            n = nodelist[i]
+            items.append(self.lookup_node(n)(n[1:]))
+        return constructor(items, lineno=extractLineNo(nodelist))
+
+    def com_stmt(self, node):
+        result = self.lookup_node(node)(node[1:])
+        assert result is not None
+        if isinstance(result, Stmt):
+            return result
+        return Stmt([result])
+
+    def com_append_stmt(self, stmts, node):
+        result = self.lookup_node(node)(node[1:])
+        assert result is not None
+        if isinstance(result, Stmt):
+            stmts.extend(result.nodes)
+        else:
+            stmts.append(result)
+
+    if hasattr(symbol, 'list_for'):
+        def com_list_constructor(self, nodelist):
+            # listmaker: test ( list_for | (',' test)* [','] )
+            values = []
+            for i in range(1, len(nodelist)):
+                if nodelist[i][0] == symbol.list_for:
+                    assert len(nodelist[i:]) == 1
+                    return self.com_list_comprehension(values[0],
+                                                       nodelist[i])
+                elif nodelist[i][0] == token.COMMA:
+                    continue
+                values.append(self.com_node(nodelist[i]))
+            return List(values, lineno=values[0].lineno)
+
+        def com_list_comprehension(self, expr, node):
+            # list_iter: list_for | list_if
+            # list_for: 'for' exprlist 'in' testlist [list_iter]
+            # list_if: 'if' test [list_iter]
+
+            # XXX should raise SyntaxError for assignment
+
+            lineno = node[1][2]
+            fors = []
+            while node:
+                t = node[1][1]
+                if t == 'for':
+                    assignNode = self.com_assign(node[2], OP_ASSIGN)
+                    listNode = self.com_node(node[4])
+                    newfor = ListCompFor(assignNode, listNode, [])
+                    newfor.lineno = node[1][2]
+                    fors.append(newfor)
+                    if len(node) == 5:
+                        node = None
+                    else:
+                        node = self.com_list_iter(node[5])
+                elif t == 'if':
+                    test = self.com_node(node[2])
+                    newif = ListCompIf(test, lineno=node[1][2])
+                    newfor.ifs.append(newif)
+                    if len(node) == 3:
+                        node = None
+                    else:
+                        node = self.com_list_iter(node[3])
+                else:
+                    raise SyntaxError, \
+                          ("unexpected list comprehension element: %s %d"
+                           % (node, lineno))
+            return ListComp(expr, fors, lineno=lineno)
+
+        def com_list_iter(self, node):
+            assert node[0] == symbol.list_iter
+            return node[1]
+    else:
+        def com_list_constructor(self, nodelist):
+            values = []
+            for i in range(1, len(nodelist), 2):
+                values.append(self.com_node(nodelist[i]))
+            return List(values, lineno=values[0].lineno)
+
+    if hasattr(symbol, 'gen_for'):
+        def com_generator_expression(self, expr, node):
+            # gen_iter: gen_for | gen_if
+            # gen_for: 'for' exprlist 'in' test [gen_iter]
+            # gen_if: 'if' test [gen_iter]
+
+            lineno = node[1][2]
+            fors = []
+            while node:
+                t = node[1][1]
+                if t == 'for':
+                    assignNode = self.com_assign(node[2], OP_ASSIGN)
+                    genNode = self.com_node(node[4])
+                    newfor = GenExprFor(assignNode, genNode, [],
+                                        lineno=node[1][2])
+                    fors.append(newfor)
+                    if (len(node)) == 5:
+                        node = None
+                    else:
+                        node = self.com_gen_iter(node[5])
+                elif t == 'if':
+                    test = self.com_node(node[2])
+                    newif = GenExprIf(test, lineno=node[1][2])
+                    newfor.ifs.append(newif)
+                    if len(node) == 3:
+                        node = None
+                    else:
+                        node = self.com_gen_iter(node[3])
+                else:
+                    raise SyntaxError, \
+                            ("unexpected generator expression element: %s %d"
+                             % (node, lineno))
+            fors[0].is_outmost = True
+            return GenExpr(GenExprInner(expr, fors), lineno=lineno)
+
+        def com_gen_iter(self, node):
+            assert node[0] == symbol.gen_iter
+            return node[1]
+
+    def com_dictmaker(self, nodelist):
+        # dictmaker: test ':' test (',' test ':' value)* [',']
+        items = []
+        for i in range(1, len(nodelist), 4):
+            items.append((self.com_node(nodelist[i]),
+                          self.com_node(nodelist[i+2])))
+        return Dict(items, lineno=items[0][0].lineno)
+
+    def com_apply_trailer(self, primaryNode, nodelist):
+        t = nodelist[1][0]
+        if t == token.LPAR:
+            return self.com_call_function(primaryNode, nodelist[2])
+        if t == token.DOT:
+            return self.com_select_member(primaryNode, nodelist[2])
+        if t == token.LSQB:
+            return self.com_subscriptlist(primaryNode, nodelist[2], OP_APPLY)
+
+        raise SyntaxError, 'unknown node type: %s' % t
+
+    def com_select_member(self, primaryNode, nodelist):
+        if nodelist[0] != token.NAME:
+            raise SyntaxError, "member must be a name"
+        return Getattr(primaryNode, nodelist[1], lineno=nodelist[2])
+
+    def com_call_function(self, primaryNode, nodelist):
+        if nodelist[0] == token.RPAR:
+            return CallFunc(primaryNode, [], lineno=extractLineNo(nodelist))
+        args = []
+        kw = 0
+        star_node = dstar_node = None
+        len_nodelist = len(nodelist)
+        i = 1
+        while i < len_nodelist:
+            node = nodelist[i]
+
+            if node[0]==token.STAR:
+                if star_node is not None:
+                    raise SyntaxError, 'already have the varargs indentifier'
+                star_node = self.com_node(nodelist[i+1])
+                i = i + 3
+                continue
+            elif node[0]==token.DOUBLESTAR:
+                if dstar_node is not None:
+                    raise SyntaxError, 'already have the kwargs indentifier'
+                dstar_node = self.com_node(nodelist[i+1])
+                i = i + 3
+                continue
+
+            # positional or named parameters
+            kw, result = self.com_argument(node, kw, star_node)
+
+            if len_nodelist != 2 and isinstance(result, GenExpr) \
+               and len(node) == 3 and node[2][0] == symbol.gen_for:
+                # allow f(x for x in y), but reject f(x for x in y, 1)
+                # should use f((x for x in y), 1) instead of f(x for x in y, 1)
+                raise SyntaxError, 'generator expression needs parenthesis'
+
+            args.append(result)
+            i = i + 2
+
+        return CallFunc(primaryNode, args, star_node, dstar_node,
+                        lineno=extractLineNo(nodelist))
+
+    def com_argument(self, nodelist, kw, star_node):
+        if len(nodelist) == 3 and nodelist[2][0] == symbol.gen_for:
+            test = self.com_node(nodelist[1])
+            return 0, self.com_generator_expression(test, nodelist[2])
+        if len(nodelist) == 2:
+            if kw:
+                raise SyntaxError, "non-keyword arg after keyword arg"
+            if star_node:
+                raise SyntaxError, "only named arguments may follow *expression"
+            return 0, self.com_node(nodelist[1])
+        result = self.com_node(nodelist[3])
+        n = nodelist[1]
+        while len(n) == 2 and n[0] != token.NAME:
+            n = n[1]
+        if n[0] != token.NAME:
+            raise SyntaxError, "keyword can't be an expression (%s)"%n[0]
+        node = Keyword(n[1], result, lineno=n[2])
+        return 1, node
+
+    def com_subscriptlist(self, primary, nodelist, assigning):
+        # slicing:      simple_slicing | extended_slicing
+        # simple_slicing:   primary "[" short_slice "]"
+        # extended_slicing: primary "[" slice_list "]"
+        # slice_list:   slice_item ("," slice_item)* [","]
+
+        # backwards compat slice for '[i:j]'
+        if len(nodelist) == 2:
+            sub = nodelist[1]
+            if (sub[1][0] == token.COLON or \
+                            (len(sub) > 2 and sub[2][0] == token.COLON)) and \
+                            sub[-1][0] != symbol.sliceop:
+                return self.com_slice(primary, sub, assigning)
+
+        subscripts = []
+        for i in range(1, len(nodelist), 2):
+            subscripts.append(self.com_subscript(nodelist[i]))
+        return Subscript(primary, assigning, subscripts,
+                         lineno=extractLineNo(nodelist))
+
+    def com_subscript(self, node):
+        # slice_item: expression | proper_slice | ellipsis
+        ch = node[1]
+        t = ch[0]
+        if t == token.DOT and node[2][0] == token.DOT:
+            return Ellipsis()
+        if t == token.COLON or len(node) > 2:
+            return self.com_sliceobj(node)
+        return self.com_node(ch)
+
+    def com_sliceobj(self, node):
+        # proper_slice: short_slice | long_slice
+        # short_slice:  [lower_bound] ":" [upper_bound]
+        # long_slice:   short_slice ":" [stride]
+        # lower_bound:  expression
+        # upper_bound:  expression
+        # stride:       expression
+        #
+        # Note: a stride may be further slicing...
+
+        items = []
+
+        if node[1][0] == token.COLON:
+            items.append(Const(None))
+            i = 2
+        else:
+            items.append(self.com_node(node[1]))
+            # i == 2 is a COLON
+            i = 3
+
+        if i < len(node) and node[i][0] == symbol.test:
+            items.append(self.com_node(node[i]))
+            i = i + 1
+        else:
+            items.append(Const(None))
+
+        # a short_slice has been built. look for long_slice now by looking
+        # for strides...
+        for j in range(i, len(node)):
+            ch = node[j]
+            if len(ch) == 2:
+                items.append(Const(None))
+            else:
+                items.append(self.com_node(ch[2]))
+        return Sliceobj(items, lineno=extractLineNo(node))
+
+    def com_slice(self, primary, node, assigning):
+        # short_slice:  [lower_bound] ":" [upper_bound]
+        lower = upper = None
+        if len(node) == 3:
+            if node[1][0] == token.COLON:
+                upper = self.com_node(node[2])
+            else:
+                lower = self.com_node(node[1])
+        elif len(node) == 4:
+            lower = self.com_node(node[1])
+            upper = self.com_node(node[3])
+        return Slice(primary, assigning, lower, upper,
+                     lineno=extractLineNo(node))
+
+    def get_docstring(self, node, n=None):
+        if n is None:
+            n = node[0]
+            node = node[1:]
+        if n == symbol.suite:
+            if len(node) == 1:
+                return self.get_docstring(node[0])
+            for sub in node:
+                if sub[0] == symbol.stmt:
+                    return self.get_docstring(sub)
+            return None
+        if n == symbol.file_input:
+            for sub in node:
+                if sub[0] == symbol.stmt:
+                    return self.get_docstring(sub)
+            return None
+        if n == symbol.atom:
+            if node[0][0] == token.STRING:
+                s = ''
+                for t in node:
+                    s = s + eval(t[1])
+                return s
+            return None
+        if n == symbol.stmt or n == symbol.simple_stmt \
+           or n == symbol.small_stmt:
+            return self.get_docstring(node[0])
+        if n in _doc_nodes and len(node) == 1:
+            return self.get_docstring(node[0])
+        return None
+
+
+_doc_nodes = [
+    symbol.expr_stmt,
+    symbol.testlist,
+    symbol.testlist_safe,
+    symbol.test,
+    symbol.or_test,
+    symbol.and_test,
+    symbol.not_test,
+    symbol.comparison,
+    symbol.expr,
+    symbol.xor_expr,
+    symbol.and_expr,
+    symbol.shift_expr,
+    symbol.arith_expr,
+    symbol.term,
+    symbol.factor,
+    symbol.power,
+    ]
+
+# comp_op: '<' | '>' | '=' | '>=' | '<=' | '<>' | '!=' | '=='
+#             | 'in' | 'not' 'in' | 'is' | 'is' 'not'
+_cmp_types = {
+    token.LESS : '<',
+    token.GREATER : '>',
+    token.EQEQUAL : '==',
+    token.EQUAL : '==',
+    token.LESSEQUAL : '<=',
+    token.GREATEREQUAL : '>=',
+    token.NOTEQUAL : '!=',
+    }
+
+_legal_node_types = [
+    symbol.funcdef,
+    symbol.classdef,
+    symbol.stmt,
+    symbol.small_stmt,
+    symbol.flow_stmt,
+    symbol.simple_stmt,
+    symbol.compound_stmt,
+    symbol.expr_stmt,
+    symbol.print_stmt,
+    symbol.del_stmt,
+    symbol.pass_stmt,
+    symbol.break_stmt,
+    symbol.continue_stmt,
+    symbol.return_stmt,
+    symbol.raise_stmt,
+    symbol.import_stmt,
+    symbol.global_stmt,
+    symbol.exec_stmt,
+    symbol.assert_stmt,
+    symbol.if_stmt,
+    symbol.while_stmt,
+    symbol.for_stmt,
+    symbol.try_stmt,
+    symbol.with_stmt,
+    symbol.suite,
+    symbol.testlist,
+    symbol.testlist_safe,
+    symbol.test,
+    symbol.and_test,
+    symbol.not_test,
+    symbol.comparison,
+    symbol.exprlist,
+    symbol.expr,
+    symbol.xor_expr,
+    symbol.and_expr,
+    symbol.shift_expr,
+    symbol.arith_expr,
+    symbol.term,
+    symbol.factor,
+    symbol.power,
+    symbol.atom,
+    ]
+
+if hasattr(symbol, 'yield_stmt'):
+    _legal_node_types.append(symbol.yield_stmt)
+if hasattr(symbol, 'yield_expr'):
+    _legal_node_types.append(symbol.yield_expr)
+
+_assign_types = [
+    symbol.test,
+    symbol.or_test,
+    symbol.and_test,
+    symbol.not_test,
+    symbol.comparison,
+    symbol.expr,
+    symbol.xor_expr,
+    symbol.and_expr,
+    symbol.shift_expr,
+    symbol.arith_expr,
+    symbol.term,
+    symbol.factor,
+    ]
+
+_names = {}
+for k, v in symbol.sym_name.items():
+    _names[k] = v
+for k, v in token.tok_name.items():
+    _names[k] = v
+
+def debug_tree(tree):
+    l = []
+    for elt in tree:
+        if isinstance(elt, int):
+            l.append(_names.get(elt, elt))
+        elif isinstance(elt, str):
+            l.append(elt)
+        else:
+            l.append(debug_tree(elt))
+    return l
diff -r 000000000000 -r 7bec0014e871 compiler/visitor.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/compiler/visitor.py	Fri May 18 20:51:41 2012 +0200
@@ -0,0 +1,113 @@
+from compiler import ast
+
+# XXX should probably rename ASTVisitor to ASTWalker
+# XXX can it be made even more generic?
+
+class ASTVisitor:
+    """Performs a depth-first walk of the AST
+
+    The ASTVisitor will walk the AST, performing either a preorder or
+    postorder traversal depending on which method is called.
+
+    methods:
+    preorder(tree, visitor)
+    postorder(tree, visitor)
+        tree: an instance of ast.Node
+        visitor: an instance with visitXXX methods
+
+    The ASTVisitor is responsible for walking over the tree in the
+    correct order.  For each node, it checks the visitor argument for
+    a method named 'visitNodeType' where NodeType is the name of the
+    node's class, e.g. Class.  If the method exists, it is called
+    with the node as its sole argument.
+
+    The visitor method for a particular node type can control how
+    child nodes are visited during a preorder walk.  (It can't control
+    the order during a postorder walk, because it is called _after_
+    the walk has occurred.)  The ASTVisitor modifies the visitor
+    argument by adding a visit method to the visitor; this method can
+    be used to visit a child node of arbitrary type.
+    """
+
+    VERBOSE = 0
+
+    def __init__(self):
+        self.node = None
+        self._cache = {}
+
+    def default(self, node, *args):
+        for child in node.getChildNodes():
+            self.dispatch(child, *args)
+
+    def dispatch(self, node, *args):
+        self.node = node
+        klass = node.__class__
+        meth = self._cache.get(klass, None)
+        if meth is None:
+            className = klass.__name__
+            meth = getattr(self.visitor, 'visit' + className, self.default)
+            self._cache[klass] = meth
+##        if self.VERBOSE > 0:
+##            className = klass.__name__
+##            if self.VERBOSE == 1:
+##                if meth == 0:
+##                    print "dispatch", className
+##            else:
+##                print "dispatch", className, (meth and meth.__name__ or '')
+        return meth(node, *args)
+
+    def preorder(self, tree, visitor, *args):
+        """Do preorder walk of tree using visitor"""
+        self.visitor = visitor
+        visitor.visit = self.dispatch
+        self.dispatch(tree, *args) # XXX *args make sense?
+
+class ExampleASTVisitor(ASTVisitor):
+    """Prints examples of the nodes that aren't visited
+
+    This visitor-driver is only useful for development, when it's
+    helpful to develop a visitor incrementally, and get feedback on what
+    you still have to do.
+    """
+    examples = {}
+
+    def dispatch(self, node, *args):
+        self.node = node
+        meth = self._cache.get(node.__class__, None)
+        className = node.__class__.__name__
+        if meth is None:
+            meth = getattr(self.visitor, 'visit' + className, 0)
+            self._cache[node.__class__] = meth
+        if self.VERBOSE > 1:
+            print "dispatch", className, (meth and meth.__name__ or '')
+        if meth:
+            meth(node, *args)
+        elif self.VERBOSE > 0:
+            klass = node.__class__
+            if klass not in self.examples:
+                self.examples[klass] = klass
+                print
+                print self.visitor
+                print klass
+                for attr in dir(node):
+                    if attr[0] != '_':
+                        print "\t", "%-12.12s" % attr, getattr(node, attr)
+                print
+            return self.default(node, *args)
+
+# XXX this is an API change
+
+_walker = ASTVisitor
+def walk(tree, visitor, walker=None, verbose=None):
+    if walker is None:
+        walker = _walker()
+    if verbose is not None:
+        walker.VERBOSE = verbose
+    walker.preorder(tree, visitor)
+    return walker.visitor
+
+def dumpNode(node):
+    print node.__class__
+    for attr in dir(node):
+        if attr[0] != '_':
+            print "\t", "%-10.10s" % attr, getattr(node, attr)
diff -r 000000000000 -r 7bec0014e871 docs/COPYRIGHT
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/docs/COPYRIGHT	Fri May 18 20:51:41 2012 +0200
@@ -0,0 +1,24 @@
+Copyright information from Python 2.6.8
+---------------------------------------
+
+Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
+              2011, 2012
+Python Software Foundation.
+All rights reserved.
+
+Copyright (c) 2000 BeOpen.com.
+All rights reserved.
+
+Copyright (c) 1995-2001 Corporation for National Research Initiatives.
+All rights reserved.
+
+Copyright (c) 1991-1995 Stichting Mathematisch Centrum.
+All rights reserved.
+
+
+License information
+-------------------
+
+See the file "LICENSE" for information on the history of this
+software, terms & conditions for usage, and a DISCLAIMER OF ALL
+WARRANTIES.
diff -r 000000000000 -r 7bec0014e871 docs/LICENSE
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/docs/LICENSE	Fri May 18 20:51:41 2012 +0200
@@ -0,0 +1,281 @@
+A. HISTORY OF THE SOFTWARE
+==========================
+
+Python was created in the early 1990s by Guido van Rossum at Stichting
+Mathematisch Centrum (CWI, see http://www.cwi.nl) in the Netherlands
+as a successor of a language called ABC.  Guido remains Python's
+principal author, although it includes many contributions from others.
+
+In 1995, Guido continued his work on Python at the Corporation for
+National Research Initiatives (CNRI, see http://www.cnri.reston.va.us)
+in Reston, Virginia where he released several versions of the
+software.
+
+In May 2000, Guido and the Python core development team moved to
+BeOpen.com to form the BeOpen PythonLabs team.  In October of the same
+year, the PythonLabs team moved to Digital Creations (now Zope
+Corporation, see http://www.zope.com).  In 2001, the Python Software
+Foundation (PSF, see http://www.python.org/psf/) was formed, a
+non-profit organization created specifically to own Python-related
+Intellectual Property.  Zope Corporation is a sponsoring member of
+the PSF.
+
+All Python releases are Open Source (see http://www.opensource.org for
+the Open Source Definition).  Historically, most, but not all, Python
+releases have also been GPL-compatible; the table below summarizes
+the various releases.
+
+    Release         Derived     Year        Owner       GPL-
+                    from                                compatible? (1)
+
+    0.9.0 thru 1.2              1991-1995   CWI         yes
+    1.3 thru 1.5.2  1.2         1995-1999   CNRI        yes
+    1.6             1.5.2       2000        CNRI        no
+    2.0             1.6         2000        BeOpen.com  no
+    1.6.1           1.6         2001        CNRI        yes (2)
+    2.1             2.0+1.6.1   2001        PSF         no
+    2.0.1           2.0+1.6.1   2001        PSF         yes
+    2.1.1           2.1+2.0.1   2001        PSF         yes
+    2.2             2.1.1       2001        PSF         yes
+    2.1.2           2.1.1       2002        PSF         yes
+    2.1.3           2.1.2       2002        PSF         yes
+    2.2.1           2.2         2002        PSF         yes
+    2.2.2           2.2.1       2002        PSF         yes
+    2.2.3           2.2.2       2003        PSF         yes
+    2.3             2.2.2       2002-2003   PSF         yes
+    2.3.1           2.3         2002-2003   PSF         yes
+    2.3.2           2.3.1       2002-2003   PSF         yes
+    2.3.3           2.3.2       2002-2003   PSF         yes
+    2.3.4           2.3.3       2004        PSF         yes
+    2.3.5           2.3.4       2005        PSF         yes
+    2.4             2.3         2004        PSF         yes
+    2.4.1           2.4         2005        PSF         yes
+    2.4.2           2.4.1       2005        PSF         yes
+    2.4.3           2.4.2       2006        PSF         yes
+    2.4.4           2.4.3       2006        PSF         yes
+    2.5             2.4         2006        PSF         yes
+    2.5.1           2.5         2007        PSF         yes
+    2.5.2           2.5.1       2008        PSF         yes
+    2.5.3           2.5.2       2008        PSF         yes
+    2.6             2.5         2008        PSF         yes
+    2.6.1           2.6         2008        PSF         yes
+    2.6.2           2.6.1       2009        PSF         yes
+    2.6.3           2.6.2       2009        PSF         yes
+    2.6.4           2.6.3       2009        PSF         yes
+    2.6.5           2.6.4       2010        PSF         yes
+    2.6.6           2.6.5       2010        PSF         yes
+    2.6.7           2.6.6       2011        PSF         yes
+    2.6.8           2.6.7       2012        PSF         yes
+
+Footnotes:
+
+(1) GPL-compatible doesn't mean that we're distributing Python under
+    the GPL.  All Python licenses, unlike the GPL, let you distribute
+    a modified version without making your changes open source.  The
+    GPL-compatible licenses make it possible to combine Python with
+    other software that is released under the GPL; the others don't.
+
+(2) According to Richard Stallman, 1.6.1 is not GPL-compatible,
+    because its license has a choice of law clause.  According to
+    CNRI, however, Stallman's lawyer has told CNRI's lawyer that 1.6.1
+    is "not incompatible" with the GPL.
+
+Thanks to the many outside volunteers who have worked under Guido's
+direction to make these releases possible.
+
+
+B. TERMS AND CONDITIONS FOR ACCESSING OR OTHERWISE USING PYTHON
+===============================================================
+
+PYTHON SOFTWARE FOUNDATION LICENSE VERSION 2
+--------------------------------------------
+
+1. This LICENSE AGREEMENT is between the Python Software Foundation
+("PSF"), and the Individual or Organization ("Licensee") accessing and
+otherwise using this software ("Python") in source or binary form and
+its associated documentation.
+
+2. Subject to the terms and conditions of this License Agreement, PSF hereby
+grants Licensee a nonexclusive, royalty-free, world-wide license to reproduce,
+analyze, test, perform and/or display publicly, prepare derivative works,
+distribute, and otherwise use Python alone or in any derivative version,
+provided, however, that PSF's License Agreement and PSF's notice of copyright,
+i.e., "Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
+Python Software Foundation; All Rights Reserved" are retained in Python alone or
+in any derivative version prepared by Licensee.
+
+3. In the event Licensee prepares a derivative work that is based on
+or incorporates Python or any part thereof, and wants to make
+the derivative work available to others as provided herein, then
+Licensee hereby agrees to include in any such work a brief summary of
+the changes made to Python.
+
+4. PSF is making Python available to Licensee on an "AS IS"
+basis.  PSF MAKES NO REPRESENTATIONS OR WARRANTIES, EXPRESS OR
+IMPLIED.  BY WAY OF EXAMPLE, BUT NOT LIMITATION, PSF MAKES NO AND
+DISCLAIMS ANY REPRESENTATION OR WARRANTY OF MERCHANTABILITY OR FITNESS
+FOR ANY PARTICULAR PURPOSE OR THAT THE USE OF PYTHON WILL NOT
+INFRINGE ANY THIRD PARTY RIGHTS.
+
+5. PSF SHALL NOT BE LIABLE TO LICENSEE OR ANY OTHER USERS OF PYTHON
+FOR ANY INCIDENTAL, SPECIAL, OR CONSEQUENTIAL DAMAGES OR LOSS AS
+A RESULT OF MODIFYING, DISTRIBUTING, OR OTHERWISE USING PYTHON,
+OR ANY DERIVATIVE THEREOF, EVEN IF ADVISED OF THE POSSIBILITY THEREOF.
+
+6. This License Agreement will automatically terminate upon a material
+breach of its terms and conditions.
+
+7. Nothing in this License Agreement shall be deemed to create any
+relationship of agency, partnership, or joint venture between PSF and
+Licensee.  This License Agreement does not grant permission to use PSF
+trademarks or trade name in a trademark sense to endorse or promote
+products or services of Licensee, or any third party.
+
+8. By copying, installing or otherwise using Python, Licensee
+agrees to be bound by the terms and conditions of this License
+Agreement.
+
+
+BEOPEN.COM LICENSE AGREEMENT FOR PYTHON 2.0
+-------------------------------------------
+
+BEOPEN PYTHON OPEN SOURCE LICENSE AGREEMENT VERSION 1
+
+1. This LICENSE AGREEMENT is between BeOpen.com ("BeOpen"), having an
+office at 160 Saratoga Avenue, Santa Clara, CA 95051, and the
+Individual or Organization ("Licensee") accessing and otherwise using
+this software in source or binary form and its associated
+documentation ("the Software").
+
+2. Subject to the terms and conditions of this BeOpen Python License
+Agreement, BeOpen hereby grants Licensee a non-exclusive,
+royalty-free, world-wide license to reproduce, analyze, test, perform
+and/or display publicly, prepare derivative works, distribute, and
+otherwise use the Software alone or in any derivative version,
+provided, however, that the BeOpen Python License is retained in the
+Software, alone or in any derivative version prepared by Licensee.
+
+3. BeOpen is making the Software available to Licensee on an "AS IS"
+basis.  BEOPEN MAKES NO REPRESENTATIONS OR WARRANTIES, EXPRESS OR
+IMPLIED.  BY WAY OF EXAMPLE, BUT NOT LIMITATION, BEOPEN MAKES NO AND
+DISCLAIMS ANY REPRESENTATION OR WARRANTY OF MERCHANTABILITY OR FITNESS
+FOR ANY PARTICULAR PURPOSE OR THAT THE USE OF THE SOFTWARE WILL NOT
+INFRINGE ANY THIRD PARTY RIGHTS.
+
+4. BEOPEN SHALL NOT BE LIABLE TO LICENSEE OR ANY OTHER USERS OF THE
+SOFTWARE FOR ANY INCIDENTAL, SPECIAL, OR CONSEQUENTIAL DAMAGES OR LOSS
+AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THE SOFTWARE, OR ANY
+DERIVATIVE THEREOF, EVEN IF ADVISED OF THE POSSIBILITY THEREOF.
+
+5. This License Agreement will automatically terminate upon a material
+breach of its terms and conditions.
+
+6. This License Agreement shall be governed by and interpreted in all
+respects by the law of the State of California, excluding conflict of
+law provisions.  Nothing in this License Agreement shall be deemed to
+create any relationship of agency, partnership, or joint venture
+between BeOpen and Licensee.  This License Agreement does not grant
+permission to use BeOpen trademarks or trade names in a trademark
+sense to endorse or promote products or services of Licensee, or any
+third party.  As an exception, the "BeOpen Python" logos available at
+http://www.pythonlabs.com/logos.html may be used according to the
+permissions granted on that web page.
+
+7. By copying, installing or otherwise using the software, Licensee
+agrees to be bound by the terms and conditions of this License
+Agreement.
+
+
+CNRI LICENSE AGREEMENT FOR PYTHON 1.6.1
+---------------------------------------
+
+1. This LICENSE AGREEMENT is between the Corporation for National
+Research Initiatives, having an office at 1895 Preston White Drive,
+Reston, VA 20191 ("CNRI"), and the Individual or Organization
+("Licensee") accessing and otherwise using Python 1.6.1 software in
+source or binary form and its associated documentation.
+
+2. Subject to the terms and conditions of this License Agreement, CNRI
+hereby grants Licensee a nonexclusive, royalty-free, world-wide
+license to reproduce, analyze, test, perform and/or display publicly,
+prepare derivative works, distribute, and otherwise use Python 1.6.1
+alone or in any derivative version, provided, however, that CNRI's
+License Agreement and CNRI's notice of copyright, i.e., "Copyright (c)
+1995-2001 Corporation for National Research Initiatives; All Rights
+Reserved" are retained in Python 1.6.1 alone or in any derivative
+version prepared by Licensee.  Alternately, in lieu of CNRI's License
+Agreement, Licensee may substitute the following text (omitting the
+quotes): "Python 1.6.1 is made available subject to the terms and
+conditions in CNRI's License Agreement.  This Agreement together with
+Python 1.6.1 may be located on the Internet using the following
+unique, persistent identifier (known as a handle): 1895.22/1013.  This
+Agreement may also be obtained from a proxy server on the Internet
+using the following URL: http://hdl.handle.net/1895.22/1013".
+
+3. In the event Licensee prepares a derivative work that is based on
+or incorporates Python 1.6.1 or any part thereof, and wants to make
+the derivative work available to others as provided herein, then
+Licensee hereby agrees to include in any such work a brief summary of
+the changes made to Python 1.6.1.
+
+4. CNRI is making Python 1.6.1 available to Licensee on an "AS IS"
+basis.  CNRI MAKES NO REPRESENTATIONS OR WARRANTIES, EXPRESS OR
+IMPLIED.  BY WAY OF EXAMPLE, BUT NOT LIMITATION, CNRI MAKES NO AND
+DISCLAIMS ANY REPRESENTATION OR WARRANTY OF MERCHANTABILITY OR FITNESS
+FOR ANY PARTICULAR PURPOSE OR THAT THE USE OF PYTHON 1.6.1 WILL NOT
+INFRINGE ANY THIRD PARTY RIGHTS.
+
+5. CNRI SHALL NOT BE LIABLE TO LICENSEE OR ANY OTHER USERS OF PYTHON
+1.6.1 FOR ANY INCIDENTAL, SPECIAL, OR CONSEQUENTIAL DAMAGES OR LOSS AS
+A RESULT OF MODIFYING, DISTRIBUTING, OR OTHERWISE USING PYTHON 1.6.1,
+OR ANY DERIVATIVE THEREOF, EVEN IF ADVISED OF THE POSSIBILITY THEREOF.
+
+6. This License Agreement will automatically terminate upon a material
+breach of its terms and conditions.
+
+7. This License Agreement shall be governed by the federal
+intellectual property law of the United States, including without
+limitation the federal copyright law, and, to the extent such
+U.S. federal law does not apply, by the law of the Commonwealth of
+Virginia, excluding Virginia's conflict of law provisions.
+Notwithstanding the foregoing, with regard to derivative works based
+on Python 1.6.1 that incorporate non-separable material that was
+previously distributed under the GNU General Public License (GPL), the
+law of the Commonwealth of Virginia shall govern this License
+Agreement only as to issues arising under or with respect to
+Paragraphs 4, 5, and 7 of this License Agreement.  Nothing in this
+License Agreement shall be deemed to create any relationship of
+agency, partnership, or joint venture between CNRI and Licensee.  This
+License Agreement does not grant permission to use CNRI trademarks or
+trade name in a trademark sense to endorse or promote products or
+services of Licensee, or any third party.
+
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