Chip 2007 January, February, March & April/Chip-Cover-CD-2007-02.iso/Pakiet bezpieczenstwa/mini Pentoo LiveCD 2006.1/mpentoo-2006.1.iso/livecd.squashfs/usr/lib/python2.4/compiler/pycodegen.pyc

Python Compiled Bytecode | 2005-10-18 | 50KB | 1,656 lines

# Source Generated with Decompyle++
# File: in.pyc (Python 2.4)

import imp
import os
import marshal
import struct
import sys
import types
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_GENERATOR_ALLOWED, CO_FUTURE_DIVISION
from compiler.pyassem import TupleArg

try:
    VERSION = sys.version_info[0]
except AttributeError:
    VERSION = 1

callfunc_opcode_info = {
    (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

    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

    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


    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 as 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):
        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)



    def getLocals(self):
        for elt in self.globals.elements():
            if self.names.has_elt(elt):
                self.names.remove(elt)
                continue

        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:
            if not alias:
                pass
            self.names.add(name)



    def visitFrom(self, node):
        for name, alias in node.names:
            if not alias:
                pass
            self.names.add(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
    __initialized = None
    class_name = None

    def __init__(self):
        if self._CodeGenerator__initialized is None:
            self.initClass()
            self.__class__._CodeGenerator__initialized = 1

        self.checkClass()
        self.locals = misc.Stack()
        self.setups = misc.Stack()
        self.last_lineno = None
        self._setupGraphDelegation()
        self._div_op = 'BINARY_DIVIDE'
        futures = self.get_module().futures
        for feature in futures:
            if feature == 'division':
                self.graph.setFlag(CO_FUTURE_DIVISION)
                self._div_op = 'BINARY_TRUE_DIVIDE'
                continue
            if feature == 'generators':
                self.graph.setFlag(CO_GENERATOR_ALLOWED)
                continue



    def initClass(self):
        '''This method is called once for each class'''
        pass


    def checkClass(self):
        '''Verify that class is constructed correctly'''

        try:
            if not hasattr(self, 'graph'):
                raise AssertionError
            if not getattr(self, 'NameFinder'):
                raise AssertionError
            if not getattr(self, 'FunctionGen'):
                raise AssertionError
            if not getattr(self, 'ClassGen'):
                raise AssertionError
        except AssertionError:
            msg = None
            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'


    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)


    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:
            if lineno != self.last_lineno or force:
                self.emit('SET_LINENO', lineno)
                self.last_lineno = lineno
                return True

        return False

    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)

        frees = gen.scope.get_free_vars()
        if frees:
            for name in frees:
                self.emit('LOAD_CLOSURE', name)

            self.emit('LOAD_CONST', gen)
            self.emit('MAKE_CLOSURE', len(node.defaults))
        else:
            self.emit('LOAD_CONST', gen)
            self.emit('MAKE_FUNCTION', 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))
        frees = gen.scope.get_free_vars()
        for name in frees:
            self.emit('LOAD_CLOSURE', name)

        self.emit('LOAD_CONST', gen)
        if frees:
            self.emit('MAKE_CLOSURE', 0)
        else:
            self.emit('MAKE_FUNCTION', 0)
        self.emit('CALL_FUNCTION', 0)
        self.emit('BUILD_CLASS')
        self.storeName(node.name)


    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):
                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)
        if not else_:
            pass
        self.emit('JUMP_IF_FALSE', after)
        self.nextBlock()
        self.emit('POP_TOP')
        self.visit(node.body)
        self.emit('JUMP_ABSOLUTE', loop)
        self.startBlock(else_)
        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)
            top = len(self.setups)
            while top > 0:
                top = top - 1
                (kind, loop_block) = self.setups[top]
                if kind == LOOP:
                    break
                    continue
            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 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')

        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_count = 0

    def visitListComp(self, node):
        self.set_lineno(node)
        append = '$append%d' % self._CodeGenerator__list_count
        self._CodeGenerator__list_count = self._CodeGenerator__list_count + 1
        self.emit('BUILD_LIST', 0)
        self.emit('DUP_TOP')
        self.emit('LOAD_ATTR', 'append')
        self._implicitNameOp('STORE', append)
        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', append)
        self.visit(node.expr)
        self.emit('CALL_FUNCTION', 1)
        self.emit('POP_TOP')
        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', append)
        self._CodeGenerator__list_count = self._CodeGenerator__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 visitGenExpr(self, node):
        gen = GenExprCodeGenerator(node, self.scopes, self.class_name, self.get_module())
        walk(node.code, gen)
        gen.finish()
        self.set_lineno(node)
        frees = gen.scope.get_free_vars()
        if frees:
            for name in frees:
                self.emit('LOAD_CLOSURE', name)

            self.emit('LOAD_CONST', gen)
            self.emit('MAKE_CLOSURE', 0)
        else:
            self.emit('LOAD_CONST', gen)
            self.emit('MAKE_FUNCTION', 0)
        self.visit(node.code.quals[0].iter)
        self.emit('GET_ITER')
        self.emit('CALL_FUNCTION', 1)


    def visitGenExprInner(self, node):
        self.set_lineno(node)
        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.visit(node.expr)
        self.emit('YIELD_VALUE')
        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.emit('LOAD_CONST', None)


    def visitGenExprFor(self, node):
        start = self.newBlock()
        anchor = self.newBlock()
        if node.is_outmost:
            self.loadName('[outmost-iterable]')
        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)


    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')


    def visitAssert(self, node):
        if __debug__:
            end = self.newBlock()
            self.set_lineno(node)
            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:
                self.emit('POP_TOP')
                continue

        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()


    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):
        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)
        for name, alias in node.names:
            if VERSION > 1:
                self.emit('LOAD_CONST', None)

            self.emit('IMPORT_NAME', name)
            mod = name.split('.')[0]
            if alias:
                self._resolveDots(name)
                self.storeName(alias)
                continue
            self.storeName(mod)



    def visitFrom(self, node):
        self.set_lineno(node)
        fromlist = map((lambda .0: (name, alias) = .0name), node.names)
        if VERSION > 1:
            self.emit('LOAD_CONST', tuple(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')
                    if not len(node.names) == 1:
                        raise AssertionError
                    return None
                else:
                    self.emit('IMPORT_FROM', name)
                    self._resolveDots(name)
                    if not alias:
                        pass
                    self.storeName(name)
            name == '*'
            self.emit('IMPORT_FROM', name)

        self.emit('POP_TOP')


    def _resolveDots(self, name):
        elts = name.split('.')
        if len(elts) == 1:
            return None

        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))


    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)
                continue



    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')


    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 len(node.subs) > 1:
            raise SyntaxError, 'augmented assignment to tuple is not possible'

        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
                continue
            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')
                continue
            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')


    def visitSlice(self, node, aug_flag = None):
        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 aug_flag:
            self.emit('DUP_TOPX', 2)

        if len(node.subs) > 1:
            self.emit('BUILD_TUPLE', len(node.subs))

        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')



    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')


    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')


    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')


    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._ModuleCodeGenerator__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._ExpressionCodeGenerator__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._InteractiveCodeGenerator__super_init()
        self.set_lineno(tree)
        walk(tree, self)
        self.emit('RETURN_VALUE')


    def get_module(self):
        return self


    def visitDiscard(self, node):
        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 type(arg) == types.TupleType:
                self.emit('LOAD_FAST', '.%d' % i * 2)
                self.unpackSequence(arg)
                continue



    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 type(elt) == types.TupleType:
                self.unpackSequence(elt)
                continue
            self._nameOp('STORE', elt)


    unpackTuple = unpackSequence


class FunctionCodeGenerator(NestedScopeMixin, AbstractFunctionCode, CodeGenerator):
    super_init = CodeGenerator.__init__
    scopes = None
    __super_init = AbstractFunctionCode.__init__

    def __init__(self, func, scopes, isLambda, class_name, mod):
        self.scopes = scopes
        self.scope = scopes[func]
        self._FunctionCodeGenerator__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__
    scopes = None
    __super_init = AbstractFunctionCode.__init__

    def __init__(self, gexp, scopes, class_name, mod):
        self.scopes = scopes
        self.scope = scopes[gexp]
        self._GenExprCodeGenerator__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._ClassCodeGenerator__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 type(elt) == types.StringType:
            args.append(elt)
            continue
        if type(elt) == types.TupleType:
            args.append(TupleArg(i * 2, elt))
            extra.extend(misc.flatten(elt))
            count = count + 1
            continue
        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)