complete rewrite

code generator uses flowgraph as intermediate representation.  the old
    rep uses a list with explicit "StackRefs" to indicate the target
    of jumps.

pyassem converts flowgraph to bytecode, breaks up individual steps of
    generating bytecode

2 files changed, 831 insertions, 800 deletions

diff --git a/Lib/compiler/pyassem.py b/Lib/compiler/pyassem.py
index 4cb910c..3272419 100644
--- a/Lib/compiler/pyassem.py
+++ b/Lib/compiler/pyassem.py
@@ -1,40 +1,127 @@
-"""Assembler for Python bytecode
-
-The new module is used to create the code object.  The following
-attribute definitions are included from the reference manual:
-
-co_name gives the function name
-co_argcount is the number of positional arguments (including
-    arguments with default values) 
-co_nlocals is the number of local variables used by the function
-    (including arguments)  
-co_varnames is a tuple containing the names of the local variables
-    (starting with the argument names) 
-co_code is a string representing the sequence of bytecode instructions 
-co_consts is a tuple containing the literals used by the bytecode
-co_names is a tuple containing the names used by the bytecode
-co_filename is the filename from which the code was compiled
-co_firstlineno is the first line number of the function
-co_lnotab is a string encoding the mapping from byte code offsets
-    to line numbers.  see LineAddrTable below.
-co_stacksize is the required stack size (including local variables)
-co_flags is an integer encoding a number of flags for the
-    interpreter.  There are four flags:
-    CO_OPTIMIZED -- uses load fast
-    CO_NEWLOCALS -- everything?
-    CO_VARARGS -- use *args
-    CO_VARKEYWORDS -- uses **args
-
-If a code object represents a function, the first item in co_consts is
-the documentation string of the function, or None if undefined.
-"""
-
-import sys
+"""A flow graph representation for Python bytecode"""
+
 import dis
 import new
 import string
+import types
+
+from compiler import misc
+
+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):
+	self.current = block
+
+    def nextBlock(self, block=None):
+	if block is None:
+	    block = self.newBlock()
+	# XXX think we need to specify when there is implicit transfer
+	# from one block to the next
+	#
+	# 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
+	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)
+
+    def emit(self, *inst):
+	# XXX should jump instructions implicitly call nextBlock?
+	if inst[0] == 'RETURN_VALUE':
+	    self.current.addOutEdge(self.exit)
+	self.current.emit(inst)
+
+    def getBlocks(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()
+	# hack alert
+	if not self.exit in order:
+	    order.append(self.exit)
+	return order
+
+def dfs_postorder(b, seen):
+    """Depth-first search of tree rooted at b, return in postorder"""
+    order = []
+    seen[b] = b
+    for c in b.children():
+	if seen.has_key(c):
+	    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 len=%d>" % (self.label, self.bid,
+						len(self.insts)) 
+	else:
+	    return "<block id=%d len=%d>" % (self.bid, len(self.insts))
+
+    def __str__(self):
+	insts = map(str, self.insts)
+	return "<block %s %d:\n%s>" % (self.label, self.bid,
+				       string.join(insts, '\n')) 
+
+    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)
 
-import misc
+    def children(self):
+	return self.outEdges.elements() + self.next
 
 # flags for code objects
 CO_OPTIMIZED = 0x0001
@@ -42,224 +129,128 @@ CO_NEWLOCALS = 0x0002
 CO_VARARGS = 0x0004
 CO_VARKEYWORDS = 0x0008
 
-class TupleArg:
-    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 ".nested%d" % self.count
-
-class PyAssembler:
-    """Creates Python code objects
-    """
-
-    # XXX this class needs to major refactoring
-
-    def __init__(self, args=(), name='?', filename='<?>',
-                 docstring=None):
-        # XXX why is the default value for flags 3?
-        self.insts = []
-        # used by makeCodeObject
-        self._getArgCount(args)
-        self.code = ''
-        self.consts = [docstring]
-        self.filename = filename
-        self.flags = CO_NEWLOCALS
-        self.name = name
-        self.names = []
+# 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):
+	self.super_init()
+	self.name = name
+	self.filename = filename
+	self.docstring = None
+	self.args = args # XXX
+	self.argcount = getArgCount(args)
+	if optimized:
+	    self.flags = CO_OPTIMIZED | CO_NEWLOCALS 
+	else:
+	    self.flags = 0
+	self.firstlineno = None
+	self.consts = []
+	self.names = []
         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()
-        # lnotab support
-        self.firstlineno = 0
-        self.lastlineno = 0
-        self.last_addr = 0
-        self.lnotab = ''
-
-    def _getArgCount(self, args):
-        self.argcount = len(args)
-        if args:
-            for arg in args:
-                if isinstance(arg, TupleArg):
-                    numNames = len(misc.flatten(arg.names))
-                    self.argcount = self.argcount - numNames 
+        self.stage = RAW
 
-    def __repr__(self):
-        return "<bytecode: %d instrs>" % len(self.insts)
-
-    def setFlags(self, val):
-        """XXX for module's function"""
-        self.flags = val
-
-    def setOptimized(self):
-        self.flags = self.flags | CO_OPTIMIZED
-
-    def setVarArgs(self):
-        if not self.flags & CO_VARARGS:
-            self.flags = self.flags | CO_VARARGS
-            self.argcount = self.argcount - 1
-
-    def setKWArgs(self):
-        self.flags = self.flags | CO_VARKEYWORDS
-
-    def getCurInst(self):
-        return len(self.insts)
+    def setDocstring(self, doc):
+        self.docstring = doc
+        self.consts.insert(0, doc)
 
-    def getNextInst(self):
-        return len(self.insts) + 1
+    def setFlag(self, flag):
+	self.flags = self.flags | flag
+	if flag == CO_VARARGS:
+	    self.argcount = self.argcount - 1
 
-    def dump(self, io=sys.stdout):
-        i = 0
-        for inst in self.insts:
-            if inst[0] == 'SET_LINENO':
-                io.write("\n")
-            io.write("    %3d " % i)
-            if len(inst) == 1:
-                io.write("%s\n" % inst)
-            else:
-                io.write("%-15.15s\t%s\n" % inst)
-            i = i + 1
-
-    def makeCodeObject(self):
-        """Make a Python code object
-
-        This creates a Python code object using the new module.  This
-        seems simpler than reverse-engineering the way marshal dumps
-        code objects into .pyc files.  One of the key difficulties is
-        figuring out how to layout references to code objects that
-        appear on the VM stack; e.g.
-          3 SET_LINENO          1
-          6 LOAD_CONST          0 (<code object fact at 8115878 [...]
-          9 MAKE_FUNCTION       0
-         12 STORE_NAME          0 (fact)
-        """
-        
-        self._findOffsets()
-        lnotab = LineAddrTable()
+    def getCode(self):
+	"""Get a Python code object"""
+	if self.stage == RAW:
+            self.flattenGraph()
+        if self.stage == FLAT:
+            self.convertArgs()
+        if self.stage == CONV:
+            self.makeByteCode()
+        if self.stage == DONE:
+            return self.newCodeObject()
+        raise RuntimeError, "inconsistent PyFlowGraph state"
+
+    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:
-                lnotab.addCode(self.opnum[opname])
-            elif len(t) == 2:
-                if opname == 'SET_LINENO':
-		    oparg = t[1]
-                    lnotab.nextLine(oparg)
+                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 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.getBlocks():
+	    begin[b] = pc
+	    for inst in b.getInstructions():
+		insts.append(inst)
+		if len(inst) == 1:
+		    pc = pc + 1
 		else:
-		    oparg = self._convertArg(opname, t[1])
-                try:
-                    hi, lo = divmod(oparg, 256)
-                except TypeError:
-                    raise TypeError, "untranslated arg: %s, %s" % (opname, oparg)
-                lnotab.addCode(self.opnum[opname], lo, hi)
-                
-        # why is a module a special case?
-        if self.flags == 0:
-            nlocals = 0
-        else:
-            nlocals = len(self.varnames)
-        # XXX danger! can't pass through here twice
-        if self.flags & CO_VARKEYWORDS:
-            self.argcount = self.argcount - 1
-        stacksize = findDepth(self.insts)
-        try:
-            co = new.code(self.argcount, nlocals, stacksize,
-                          self.flags, lnotab.getCode(), self._getConsts(),
-                          tuple(self.names), tuple(self.varnames),
-                          self.filename, self.name, self.firstlineno,
-                          lnotab.getTable())
-        except SystemError, err:
-            print err
-            print repr(self.argcount)
-            print repr(nlocals)
-            print repr(stacksize)
-            print repr(self.flags)
-            print repr(lnotab.getCode())
-            print repr(self._getConsts())
-            print repr(self.names)
-            print repr(self.varnames)
-            print repr(self.filename)
-            print repr(self.name)
-            print repr(self.firstlineno)
-            print repr(lnotab.getTable())
-            raise
-        return co
-
-    def _getConsts(self):
-        """Return a tuple for the const slot of a code object
-
-        Converts PythonVMCode objects to code objects
-        """
-        l = []
-        for elt in self.consts:
-            # XXX might be clearer to just as isinstance(CodeGen)
-            if hasattr(elt, 'asConst'):
-                l.append(elt.asConst())
+		    # 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
             else:
-                l.append(elt)
-        return tuple(l)
+                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.stacksize = findDepth(self.insts)
+	self.stage = FLAT
 
-    def _findOffsets(self):
-        """Find offsets for use in resolving StackRefs"""
-        self.offsets = []
-        cur = 0
-        for t in self.insts:
-            self.offsets.append(cur)
-            l = len(t)
-            if l == 1:
-                cur = cur + 1
-            elif l == 2:
-                cur = cur + 3
-                arg = t[1]
-                # XXX this is a total hack: for a reference used
-                # multiple times, we create a list of offsets and
-                # expect that we when we pass through the code again
-                # to actually generate the offsets, we'll pass in the
-                # same order.
-                if isinstance(arg, StackRef):
-                    try:
-                        arg.__offset.append(cur)
-                    except AttributeError:
-                        arg.__offset = [cur]
-
-    def _convertArg(self, op, arg):
-        """Convert the string representation of an arg to a number
-
-        The specific handling depends on the opcode.
-
-        XXX This first implementation isn't going to be very
-        efficient. 
-        """
-        if op == 'SET_LINENO':
-            return arg
-        if op == 'LOAD_CONST':
-            return self._lookupName(arg, self.consts)
-        if op in self.localOps:
-            # make sure it's in self.names, but use the bytecode offset
-            self._lookupName(arg, self.names)
-            return self._lookupName(arg, self.varnames)
-        if op in self.globalOps:
-            return self._lookupName(arg, self.names)
-        if op in self.nameOps:
-            return self._lookupName(arg, self.names)
-        if op == 'COMPARE_OP':
-            return self.cmp_op.index(arg)
-        if self.hasjrel.has_elt(op):
-            offset = arg.__offset[0]
-            del arg.__offset[0]
-            return self.offsets[arg.resolve()] - offset
-        if self.hasjabs.has_elt(op):
-            return self.offsets[arg.resolve()]
-        return arg
-
-    nameOps = ('STORE_NAME', 'IMPORT_NAME', 'IMPORT_FROM',
-               'STORE_ATTR', 'LOAD_ATTR', 'LOAD_NAME', 'DELETE_NAME',
-               'DELETE_ATTR')
-    localOps = ('LOAD_FAST', 'STORE_FAST', 'DELETE_FAST')
-    globalOps = ('LOAD_GLOBAL', 'STORE_GLOBAL', 'DELETE_GLOBAL')
+    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
+        for i in range(len(self.insts)):
+            t = self.insts[i]
+            if len(t) == 2:
+                opname = t[0]
+                oparg = t[1]
+                conv = self._converters.get(opname, None)
+                if conv:
+                    self.insts[i] = opname, conv(self, oparg)
+        self.stage = CONV
 
     def _lookupName(self, name, list):
         """Return index of name in list, appending if necessary"""
@@ -276,32 +267,124 @@ class PyAssembler:
         list.append(name)
         return end
 
-    # Convert some stuff from the dis module for local use
-    
-    cmp_op = list(dis.cmp_op)
-    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])
-    
+    _converters = {}
+    def _convert_LOAD_CONST(self, arg):
+        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_NAME(self, arg):
+        return self._lookupName(arg, self.names)
+    _convert_LOAD_NAME = _convert_NAME
+    _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
+
+    _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)
+                    if self.firstlineno is None:
+                        self.firstlineno = oparg
+                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
 
-    # this version of emit + arbitrary hooks might work, but it's damn
-    # messy.
+    def newCodeObject(self):
+        assert self.stage == DONE
+        if self.flags == 0:
+            nlocals = 0
+        else:
+            nlocals = len(self.varnames)
+        argcount = self.argcount
+        if self.flags & CO_VARKEYWORDS:
+            argcount = argcount - 1
+        return new.code(argcount, nlocals, self.stacksize, self.flags,
+                        self.lnotab.getCode(), self.getConsts(),
+                        tuple(self.names), tuple(self.varnames),
+                        self.filename, self.name, self.firstlineno,
+                        self.lnotab.getTable())
+
+    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
 
-    def emit(self, *args):
-        self._emitDispatch(args[0], args[1:])
-        self.insts.append(args)
+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 ".nested%d" % self.count
 
-    def _emitDispatch(self, type, args):
-        for func in self._emit_hooks.get(type, []):
-            func(self, args)
+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
 
-    _emit_hooks = {}
+def twobyte(val):
+    """Convert an int argument into high and low bytes"""
+    assert type(val) == types.IntType
+    return divmod(val, 256)
 
 class LineAddrTable:
     """lnotab
@@ -361,34 +444,9 @@ class LineAddrTable:
     def getTable(self):
         return string.join(map(chr, self.lnotab), '')
     
-class StackRef:
-    """Manage stack locations for jumps, loops, etc."""
-    count = 0
-
-    def __init__(self, id=None, val=None):
-        if id is None:
-            id = StackRef.count
-            StackRef.count = StackRef.count + 1
-        self.id = id
-        self.val = val
-
-    def __repr__(self):
-        if self.val:
-            return "StackRef(val=%d)" % self.val
-        else:
-            return "StackRef(id=%d)" % self.id
-
-    def bind(self, inst):
-        self.val = inst
-
-    def resolve(self):
-        if self.val is None:
-            print "UNRESOLVE REF", self
-            return 0
-        return self.val
-
 class StackDepthTracker:
-    # XXX need to keep track of stack depth on jumps
+    # 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):
         depth = 0
diff --git a/Lib/compiler/pycodegen.py b/Lib/compiler/pycodegen.py
index b2d55d9..2e98d4e 100644
--- a/Lib/compiler/pycodegen.py
+++ b/Lib/compiler/pycodegen.py
@@ -1,132 +1,84 @@
-"""Python bytecode generator
-
-Currently contains generic ASTVisitor code, a LocalNameFinder, and a
-CodeGenerator.  Eventually, this will get split into the ASTVisitor as
-a generic tool and CodeGenerator as a specific tool.
-"""
-
-from compiler import parseFile, ast, visitor, walk, parse
-from pyassem import StackRef, PyAssembler, TupleArg
-import dis
-import misc
-import marshal
-import new
-import string
-import sys
 import os
+import marshal
 import stat
 import struct
 import types
+from cStringIO import StringIO
 
-class CodeGenerator:
-    """Generate bytecode for the Python VM"""
-
-    OPTIMIZED = 1
-
-    # XXX should clean up initialization and generateXXX funcs
-    def __init__(self, filename="<?>"):
-        self.filename = filename
-        self.code = PyAssembler()
-        self.code.setFlags(0)
-        self.locals = misc.Stack()
-        self.loops = misc.Stack()
-        self.namespace = 0
-        self.curStack = 0
-        self.maxStack = 0
-
-    def emit(self, *args):
-        # XXX could just use self.emit = self.code.emit
-        apply(self.code.emit, args)
-
-    def _generateFunctionOrLambdaCode(self, func):
-        self.name = func.name
- 
-        # keep a lookout for 'def foo((x,y)):'
-        args, hasTupleArg = self.generateArglist(func.argnames)
-        
-        self.code = PyAssembler(args=args, name=func.name,
-                                filename=self.filename)
-        self.namespace = self.OPTIMIZED
-        if func.varargs:
-            self.code.setVarArgs()
-        if func.kwargs:
-            self.code.setKWArgs()
-        lnf = walk(func.code, LocalNameFinder(args), 0)
-        self.locals.push(lnf.getLocals())
-        self.emit('SET_LINENO', func.lineno)
-        if hasTupleArg:
-            self.generateArgUnpack(func.argnames)
-        walk(func.code, self)
+from compiler import ast, parse, walk
+from compiler import pyassem, misc
+from compiler.pyassem import CO_VARARGS, CO_VARKEYWORDS, TupleArg
 
-    def generateArglist(self, arglist):
-        args = []
-        extra = []
-        count = 0
-        for elt in arglist:
-            if type(elt) == types.StringType:
-                args.append(elt)
-            elif type(elt) == types.TupleType:
-                args.append(TupleArg(count, elt))
-                count = count + 1
-                extra.extend(misc.flatten(elt))
-            else:
-                raise ValueError, "unexpect argument type:", elt
-        return args + extra, count
+def compile(filename):
+    f = open(filename)
+    buf = f.read()
+    f.close()
+    mod = Module(buf, filename)
+    mod.compile()
+    f = open(filename + "c", "wb")
+    mod.dump(f)
+    f.close()
 
-    def generateArgUnpack(self, args):
-        count = 0
-        for arg in args:
-            if type(arg) == types.TupleType:
-                self.emit('LOAD_FAST', '.nested%d' % count)
-                count = count + 1
-                self.unpackTuple(arg)
-                        
-    def unpackTuple(self, tup):
-        self.emit('UNPACK_TUPLE', len(tup))
-        for elt in tup:
-            if type(elt) == types.TupleType:
-                self.unpackTuple(elt)
-            else:
-                self.emit('STORE_FAST', elt)
+class Module:
+    def __init__(self, source, filename):
+	self.filename = filename
+	self.source = source
+	self.code = None
 
-    def generateFunctionCode(self, func):
-        """Generate code for a function body"""
-        self._generateFunctionOrLambdaCode(func)
-        self.emit('LOAD_CONST', None)
-        self.emit('RETURN_VALUE')
+    def compile(self):
+	ast = parse(self.source)
+        root, filename = os.path.split(self.filename)
+	gen = ModuleCodeGenerator(filename)
+	walk(ast, gen, 1)
+	self.code = gen.getCode()
 
-    def generateLambdaCode(self, func):
-        self._generateFunctionOrLambdaCode(func)
-        self.emit('RETURN_VALUE')
+    def dump(self, f):
+	f.write(self.getPycHeader())
+	marshal.dump(self.code, f)
 
-    def generateClassCode(self, klass):
-        self.code = PyAssembler(name=klass.name,
-                                 filename=self.filename)
-        self.emit('SET_LINENO', klass.lineno)
-        lnf = walk(klass.code, LocalNameFinder(), 0)
-        self.locals.push(lnf.getLocals())
-        walk(klass.code, self)
-        self.emit('LOAD_LOCALS')
-        self.emit('RETURN_VALUE')
+    MAGIC = (20121 | (ord('\r')<<16) | (ord('\n')<<24))
+
+    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.
+	magic = marshal.dumps(self.MAGIC)[1:]
+	mtime = os.stat(self.filename)[stat.ST_MTIME]
+	mtime = struct.pack('i', mtime)
+	return magic + mtime
+
+class CodeGenerator:
+
+    optimized = 0 # is namespace access optimized?
+
+    def __init__(self, filename):
+## Subclasses must define a constructor that intializes self.graph
+## before calling this init function
+## 	self.graph = pyassem.PyFlowGraph()
+	self.filename = filename
+	self.locals = misc.Stack()
+	self.loops = misc.Stack()
+	self.curStack = 0
+	self.maxStack = 0
+	self._setupGraphDelegation()
+
+    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 asConst(self):
-        """Create a Python code object."""
-        if self.namespace == self.OPTIMIZED:
-            self.code.setOptimized()
-        return self.code.makeCodeObject()
+    def getCode(self):
+	"""Return a code object"""
+	return self.graph.getCode()
+
+    # Next five methods handle name access
 
     def isLocalName(self, name):
         return self.locals.top().has_elt(name)
 
-    def _nameOp(self, prefix, name):
-        if self.isLocalName(name):
-            if self.namespace == self.OPTIMIZED:
-                self.emit(prefix + '_FAST', name)
-            else:
-                self.emit(prefix + '_NAME', name)
-        else:
-            self.emit(prefix + '_GLOBAL', name)
-
     def storeName(self, name):
         self._nameOp('STORE', name)
 
@@ -136,195 +88,237 @@ class CodeGenerator:
     def delName(self, name):
         self._nameOp('DELETE', name)
 
-    def visitNULL(self, node):
-        """Method exists only to stop warning in -v mode"""
-        pass
-
-    visitStmt = visitNULL
-    visitGlobal = visitNULL
-
-    def visitDiscard(self, node):
-        self.visit(node.expr)
-        self.emit('POP_TOP')
-        return 1
+    def _nameOp(self, prefix, name):
+	if not self.optimized:
+	    self.emit(prefix + '_NAME', name)
+	    return
+        if self.isLocalName(name):
+	    self.emit(prefix + '_FAST', name)
+        else:
+            self.emit(prefix + '_GLOBAL', name)
 
-    def visitPass(self, node):
-        self.emit('SET_LINENO', node.lineno)
+    # The first few visitor methods handle nodes that generator new
+    # code objects 
 
     def visitModule(self, node):
-        lnf = walk(node.node, LocalNameFinder(), 0)
-        self.locals.push(lnf.getLocals())
-        self.visit(node.node)
-        self.emit('LOAD_CONST', None)
-        self.emit('RETURN_VALUE')
-        return 1
+	lnf = walk(node.node, LocalNameFinder(), 0)
+	self.locals.push(lnf.getLocals())
+	self.setDocstring(node.doc)
+	self.visit(node.node)
+	self.emit('LOAD_CONST', None)
+	self.emit('RETURN_VALUE')
 
-    def visitImport(self, node):
-        self.emit('SET_LINENO', node.lineno)
-        for name in node.names:
-            self.emit('IMPORT_NAME', name)
-            self.storeName(name)
+    def visitFunction(self, node):
+	self._visitFuncOrLambda(node, isLambda=0)
+	self.storeName(node.name)
 
-    def visitFrom(self, node):
-        self.emit('SET_LINENO', node.lineno)
-        self.emit('IMPORT_NAME', node.modname)
-        for name in node.names:
-            if name == '*':
-                self.namespace = 0
-            self.emit('IMPORT_FROM', name)
-        self.emit('POP_TOP')
+    def visitLambda(self, node):
+	self._visitFuncOrLambda(node, isLambda=1)
+##	self.storeName("<lambda>")
+
+    def _visitFuncOrLambda(self, node, isLambda):
+	gen = FunctionCodeGenerator(node, self.filename, isLambda)
+	walk(node.code, gen)
+	gen.finish()
+	self.emit('SET_LINENO', node.lineno)
+        for default in node.defaults:
+            self.visit(default)
+        self.emit('LOAD_CONST', gen.getCode())
+        self.emit('MAKE_FUNCTION', len(node.defaults))
 
     def visitClass(self, node):
+        gen = ClassCodeGenerator(node, self.filename)
+        walk(node.code, gen)
+        gen.finish()
         self.emit('SET_LINENO', node.lineno)
         self.emit('LOAD_CONST', node.name)
         for base in node.bases:
             self.visit(base)
         self.emit('BUILD_TUPLE', len(node.bases))
-        classBody = CodeGenerator(self.filename)
-        classBody.generateClassCode(node)
-        self.emit('LOAD_CONST', classBody)
+        self.emit('LOAD_CONST', gen.getCode())
         self.emit('MAKE_FUNCTION', 0)
         self.emit('CALL_FUNCTION', 0)
         self.emit('BUILD_CLASS')
         self.storeName(node.name)
-        return 1
 
-    def _visitFuncOrLambda(self, node, kind):
-        """Code common to Function and Lambda nodes"""
-        codeBody = CodeGenerator(self.filename)
-        getattr(codeBody, 'generate%sCode' % kind)(node)
-        self.emit('SET_LINENO', node.lineno)
-        for default in node.defaults:
-            self.visit(default)
-        self.emit('LOAD_CONST', codeBody)
-        self.emit('MAKE_FUNCTION', len(node.defaults))
+    # The rest are standard visitor methods
 
-    def visitFunction(self, node):
-        self._visitFuncOrLambda(node, 'Function')
-        self.storeName(node.name)
-        return 1
+    # The next few implement control-flow statements
 
-    def visitLambda(self, node):
-        node.name = '<lambda>'
-        self._visitFuncOrLambda(node, 'Lambda')
-        return 1
+    def visitIf(self, node):
+	end = self.newBlock()
+	numtests = len(node.tests)
+	for i in range(numtests):
+	    test, suite = node.tests[i]
+	    if hasattr(test, 'lineno'):
+		self.emit('SET_LINENO', test.lineno)
+	    self.visit(test)
+## 	    if i == numtests - 1 and not node.else_:
+## 		nextTest = end
+## 	    else:
+## 		nextTest = self.newBlock()
+	    nextTest = self.newBlock()
+	    self.emit('JUMP_IF_FALSE', nextTest)
+	    self.nextBlock()
+	    self.emit('POP_TOP')
+	    self.visit(suite)
+	    self.emit('JUMP_FORWARD', end)
+	    self.nextBlock(nextTest)
+	    self.emit('POP_TOP')
+	if node.else_:
+	    self.visit(node.else_)
+	self.nextBlock(end)
 
-    def visitCallFunc(self, node):
-        pos = 0
-        kw = 0
-        if hasattr(node, 'lineno'):
-            self.emit('SET_LINENO', node.lineno)
-        self.visit(node.node)
-        for arg in node.args:
-            self.visit(arg)
-            if isinstance(arg, ast.Keyword):
-                kw = kw + 1
-            else:
-                pos = pos + 1
-        self.emit('CALL_FUNCTION', kw << 8 | pos)
-        return 1
+    def visitWhile(self, node):
+	self.emit('SET_LINENO', node.lineno)
 
-    def visitKeyword(self, node):
-        self.emit('LOAD_CONST', node.name)
-        self.visit(node.expr)
-        return 1
+	loop = self.newBlock()
+	else_ = self.newBlock()
 
-    def visitIf(self, node):
-        after = StackRef()
-        for test, suite in node.tests:
-            if hasattr(test, 'lineno'):
-                self.emit('SET_LINENO', test.lineno)
-            else:
-                print "warning", "no line number"
-            self.visit(test)
-            dest = StackRef()
-            self.emit('JUMP_IF_FALSE', dest)
-            self.emit('POP_TOP')
-            self.visit(suite)
-            self.emit('JUMP_FORWARD', after)
-            dest.bind(self.code.getCurInst())
-            self.emit('POP_TOP')
-        if node.else_:
-            self.visit(node.else_)
-        after.bind(self.code.getCurInst())
-        return 1
+	after = self.newBlock()
+	self.emit('SETUP_LOOP', after)
+
+	self.nextBlock(loop)
+	self.loops.push(loop)
+
+	self.emit('SET_LINENO', node.lineno)
+	self.visit(node.test)
+	self.emit('JUMP_IF_FALSE', else_ or after)
 
-    def startLoop(self):
-        l = Loop()
-        self.loops.push(l)
-        self.emit('SETUP_LOOP', l.extentAnchor)
-        return l
+	self.nextBlock()
+	self.emit('POP_TOP')
+	self.visit(node.body)
+	self.emit('JUMP_ABSOLUTE', loop)
 
-    def finishLoop(self):
-        l = self.loops.pop()
-        i = self.code.getCurInst()
-        l.extentAnchor.bind(self.code.getCurInst())
+	self.startBlock(else_) # or just the POPs if not else clause
+	self.emit('POP_TOP')
+	self.emit('POP_BLOCK')
+	if node.else_:
+	    self.visit(node.else_)
+	self.loops.pop()
+	self.nextBlock(after)
 
     def visitFor(self, node):
-        # three refs needed
-        anchor = StackRef()
+	start = self.newBlock()
+        anchor = self.newBlock()
+	after = self.newBlock()
+        self.loops.push(start)
 
         self.emit('SET_LINENO', node.lineno)
-        l = self.startLoop()
+	self.emit('SETUP_LOOP', after)
         self.visit(node.list)
         self.visit(ast.Const(0))
-        l.startAnchor.bind(self.code.getCurInst())
+	self.nextBlock(start)
         self.emit('SET_LINENO', node.lineno)
         self.emit('FOR_LOOP', anchor)
         self.visit(node.assign)
         self.visit(node.body)
-        self.emit('JUMP_ABSOLUTE', l.startAnchor)
-        anchor.bind(self.code.getCurInst())
+        self.emit('JUMP_ABSOLUTE', start)
+	self.nextBlock(anchor)
         self.emit('POP_BLOCK')
         if node.else_:
             self.visit(node.else_)
-        self.finishLoop()
-        return 1
-
-    def visitWhile(self, node):
-        self.emit('SET_LINENO', node.lineno)
-        l = self.startLoop()
-        if node.else_:
-            lElse = StackRef()
-        else:
-            lElse = l.breakAnchor
-        l.startAnchor.bind(self.code.getCurInst())
-        if hasattr(node.test, 'lineno'):
-            self.emit('SET_LINENO', node.test.lineno)
-        self.visit(node.test)
-        self.emit('JUMP_IF_FALSE', lElse)
-        self.emit('POP_TOP')
-        self.visit(node.body)
-        self.emit('JUMP_ABSOLUTE', l.startAnchor)
-        # note that lElse may be an alias for l.breakAnchor
-        lElse.bind(self.code.getCurInst())
-        self.emit('POP_TOP')
-        self.emit('POP_BLOCK')
-        if node.else_:
-            self.visit(node.else_)
-        self.finishLoop()
-        return 1
+	self.loops.pop()
+	self.nextBlock(after)
 
     def visitBreak(self, node):
-        if not self.loops:
-            raise SyntaxError, "'break' outside loop"
-        self.emit('SET_LINENO', node.lineno)
-        self.emit('BREAK_LOOP')
+	if not self.loops:
+	    raise SyntaxError, "'break' outside loop (%s, %d)" % \
+		  (self.filename, node.lineno)
+	self.emit('SET_LINENO', node.lineno)
+	self.emit('BREAK_LOOP')
 
     def visitContinue(self, node):
         if not self.loops:
-            raise SyntaxError, "'continue' outside loop"
+            raise SyntaxError, "'continue' outside loop (%s, %d)" % \
+		  (self.filename, node.lineno)
         l = self.loops.top()
         self.emit('SET_LINENO', node.lineno)
-        self.emit('JUMP_ABSOLUTE', l.startAnchor)
+        self.emit('JUMP_ABSOLUTE', l)
+	self.nextBlock()
+
+    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')
+	# 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.nextBlock(cleanup)
+	    self.emit('ROT_TWO')
+	    self.emit('POP_TOP')
+	    self.nextBlock(end)
+
+    # exception related
+
+    def visitAssert(self, node):
+	# XXX would be interesting to implement this via a
+	# transformation of the AST before this stage
+	end = self.newBlock()
+	self.emit('SET_LINENO', node.lineno)
+        # XXX __debug__ and AssertionError appear to be special cases
+        # -- they are always loaded as globals even if there are local
+        # names.  I guess this is a sort of renaming op.
+	self.emit('LOAD_GLOBAL', '__debug__')
+	self.emit('JUMP_IF_FALSE', end)
+	self.nextBlock()
+	self.emit('POP_TOP')
+	self.visit(node.test)
+	self.emit('JUMP_IF_TRUE', end)
+	self.nextBlock()
+	self.emit('LOAD_GLOBAL', 'AssertionError')
+	self.visit(node.fail)
+	self.emit('RAISE_VARARGS', 2)
+	self.nextBlock(end)
+	self.emit('POP_TOP')
+
+    def visitRaise(self, node):
+        self.emit('SET_LINENO', node.lineno)
+        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):
-        # XXX need to figure out exactly what is on the stack when an
-        # exception is raised and the first handler is checked
-        handlers = StackRef()
-        end = StackRef()
+        handlers = self.newBlock()
+        end = self.newBlock()
         if node.else_:
-            lElse = StackRef()
+            lElse = self.newBlock()
         else:
             lElse = end
         self.emit('SET_LINENO', node.lineno)
@@ -332,7 +326,7 @@ class CodeGenerator:
         self.visit(node.body)
         self.emit('POP_BLOCK')
         self.emit('JUMP_FORWARD', lElse)
-        handlers.bind(self.code.getCurInst())
+	self.nextBlock(handlers)
         
         last = len(node.handlers) - 1
         for i in range(len(node.handlers)):
@@ -342,9 +336,10 @@ class CodeGenerator:
             if expr:
                 self.emit('DUP_TOP')
                 self.visit(expr)
-                self.emit('COMPARE_OP', "exception match")
-                next = StackRef()
+                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:
@@ -355,132 +350,72 @@ class CodeGenerator:
             self.visit(body)
             self.emit('JUMP_FORWARD', end)
             if expr:
-                next.bind(self.code.getCurInst())
+		self.nextBlock(next)
             self.emit('POP_TOP')
         self.emit('END_FINALLY')
         if node.else_:
-            lElse.bind(self.code.getCurInst())
+	    self.nextBlock(lElse)
             self.visit(node.else_)
-        end.bind(self.code.getCurInst())
-        return 1
+	self.nextBlock(end)
     
     def visitTryFinally(self, node):
-        final = StackRef()
+        final = self.newBlock()
         self.emit('SET_LINENO', node.lineno)
         self.emit('SETUP_FINALLY', final)
         self.visit(node.body)
         self.emit('POP_BLOCK')
         self.emit('LOAD_CONST', None)
-        final.bind(self.code.getCurInst())
+	self.nextBlock(final)
         self.visit(node.final)
         self.emit('END_FINALLY')
-        return 1
 
-    def visitCompare(self, node):
-        """Comment from compile.c follows:
-
-        The following code is generated for all but the last
-        comparison in a chain:
-           
-        label:  on stack:       opcode:         jump to:
-           
-                a               <code to load b>
-                a, b            DUP_TOP
-                a, b, b         ROT_THREE
-                b, a, b         COMPARE_OP
-                b, 0-or-1       JUMP_IF_FALSE   L1
-                b, 1            POP_TOP
-                b               
-        
-        We are now ready to repeat this sequence for the next
-        comparison in the chain.
-           
-        For the last we generate:
-           
-                b               <code to load c>
-                b, c            COMPARE_OP
-                0-or-1          
-           
-        If there were any jumps to L1 (i.e., there was more than one
-        comparison), we generate:
-           
-                0-or-1          JUMP_FORWARD    L2
-           L1:  b, 0            ROT_TWO
-                0, b            POP_TOP
-                0
-           L2:  0-or-1
-        """
-        self.visit(node.expr)
-        # if refs are never emitted, subsequent bind call has no effect
-        l1 = StackRef()
-        l2 = StackRef()
-        for op, code in node.ops[:-1]:
-            # emit every comparison except the last
-            self.visit(code)
-            self.emit('DUP_TOP')
-            self.emit('ROT_THREE')
-            self.emit('COMPARE_OP', op)
-            # dupTop and compareOp cancel stack effect
-            self.emit('JUMP_IF_FALSE', l1)
-            self.emit('POP_TOP')
-        if node.ops:
-            # emit the last comparison
-            op, code = node.ops[-1]
-            self.visit(code)
-            self.emit('COMPARE_OP', op)
-        if len(node.ops) > 1:
-            self.emit('JUMP_FORWARD', l2)
-            l1.bind(self.code.getCurInst())
-            self.emit('ROT_TWO')
-            self.emit('POP_TOP')
-            l2.bind(self.code.getCurInst())
-        return 1
+    # misc
 
-    def visitGetattr(self, node):
-        self.visit(node.expr)
-        self.emit('LOAD_ATTR', node.attrname)
-        return 1
+##     def visitStmt(self, node):
+## 	# nothing to do except walk the children
+## 	pass
 
-    def visitSubscript(self, node):
+    def visitDiscard(self, node):
         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 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')
-        return 1
+        self.emit('POP_TOP')
 
-    def visitSlice(self, node):
+    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.loadName(node.name)
+        
+    def visitPass(self, node):
+        self.emit('SET_LINENO', node.lineno)
+
+    def visitImport(self, node):
+        self.emit('SET_LINENO', node.lineno)
+        for name in node.names:
+            self.emit('IMPORT_NAME', name)
+            self.storeName(name)
+
+    def visitFrom(self, node):
+        self.emit('SET_LINENO', node.lineno)
+        self.emit('IMPORT_NAME', node.modname)
+        for name in node.names:
+            if name == '*':
+                self.namespace = 0
+            self.emit('IMPORT_FROM', name)
+        self.emit('POP_TOP')
+
+    def visitGetattr(self, node):
         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 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
-        return 1
+        self.emit('LOAD_ATTR', node.attrname)
 
-    def visitSliceobj(self, node):
-        for child in node.nodes:
-            print child
-            self.visit(child)
-        self.emit('BUILD_SLICE', len(node.nodes))
-        return 1
+    # next five implement assignments
 
     def visitAssign(self, node):
         self.emit('SET_LINENO', node.lineno)
@@ -492,7 +427,6 @@ class CodeGenerator:
                 self.emit('DUP_TOP')
             if isinstance(elt, ast.Node):
                 self.visit(elt)
-        return 1
 
     def visitAssName(self, node):
         if node.flags == 'OP_ASSIGN':
@@ -501,7 +435,6 @@ class CodeGenerator:
             self.delName(node.name)
         else:
             print "oops", node.flags
-        return 1
 
     def visitAssAttr(self, node):
         self.visit(node.expr)
@@ -512,24 +445,96 @@ class CodeGenerator:
         else:
             print "warning: unexpected flags:", node.flags
             print node
-        return 1
 
     def visitAssTuple(self, node):
         if findOp(node) != 'OP_DELETE':
             self.emit('UNPACK_TUPLE', len(node.nodes))
         for child in node.nodes:
             self.visit(child)
-        return 1
 
     visitAssList = visitAssTuple
 
+    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
+        if hasattr(node, 'lineno'):
+            self.emit('SET_LINENO', node.lineno)
+        self.visit(node.node)
+        for arg in node.args:
+            self.visit(arg)
+            if isinstance(arg, ast.Keyword):
+                kw = kw + 1
+            else:
+                pos = pos + 1
+        self.emit('CALL_FUNCTION', kw << 8 | pos)
+
+    def visitPrint(self, node):
+        self.emit('SET_LINENO', node.lineno)
+        for child in node.nodes:
+            self.visit(child)
+            self.emit('PRINT_ITEM')
+
+    def visitPrintnl(self, node):
+        self.visitPrint(node)
+        self.emit('PRINT_NEWLINE')
+
+    def visitReturn(self, node):
+        self.emit('SET_LINENO', node.lineno)
+        self.visit(node.value)
+        self.emit('RETURN_VALUE')
+
+    # slice and subscript stuff
+
+    def visitSlice(self, node):
+        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 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):
+        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 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)
-        return 1
 
     def visitAdd(self, node):
         return self.binaryOp(node, 'BINARY_ADD')
@@ -560,7 +565,6 @@ class CodeGenerator:
     def unaryOp(self, node, op):
         self.visit(node.expr)
         self.emit(op)
-        return 1
 
     def visitInvert(self, node):
         return self.unaryOp(node, 'UNARY_INVERT')
@@ -587,7 +591,6 @@ class CodeGenerator:
         for node in nodes[1:]:
             self.visit(node)
             self.emit(op)
-        return 1
 
     def visitBitand(self, node):
         return self.bitOp(node.nodes, 'BINARY_AND')
@@ -598,121 +601,137 @@ class CodeGenerator:
     def visitBitxor(self, node):
         return self.bitOp(node.nodes, 'BINARY_XOR')
 
-    def visitAssert(self, node):
-        # XXX __debug__ and AssertionError appear to be special cases
-        # -- they are always loaded as globals even if there are local
-        # names.  I guess this is a sort of renaming op.
-        skip = StackRef()
-        self.emit('SET_LINENO', node.lineno)
-        self.emit('LOAD_GLOBAL', '__debug__')
-        self.emit('JUMP_IF_FALSE', skip)
-        self.emit('POP_TOP')
-        self.visit(node.test)
-        self.emit('JUMP_IF_TRUE', skip)
-        self.emit('LOAD_GLOBAL', 'AssertionError')
-        self.visit(node.fail)
-        self.emit('RAISE_VARARGS', 2)
-        skip.bind(self.code.getCurInst())
-        self.emit('POP_TOP')
-        return 1
-
-    def visitTest(self, node, jump):
-        end = StackRef()
-        for child in node.nodes[:-1]:
-            self.visit(child)
-            self.emit(jump, end)
-            self.emit('POP_TOP')
-        self.visit(node.nodes[-1])
-        end.bind(self.code.getCurInst())
-        return 1
-
-    def visitAnd(self, node):
-        return self.visitTest(node, 'JUMP_IF_FALSE')
-
-    def visitOr(self, node):
-        return self.visitTest(node, 'JUMP_IF_TRUE')
-
-    def visitName(self, node):
-        self.loadName(node.name)
-
-    def visitConst(self, node):
-        self.emit('LOAD_CONST', node.value)
-        return 1
+    # object constructors
 
     def visitEllipsis(self, node):
         self.emit('LOAD_CONST', Ellipsis)
-        return 1
 
     def visitTuple(self, node):
         for elt in node.nodes:
             self.visit(elt)
         self.emit('BUILD_TUPLE', len(node.nodes))
-        return 1
 
     def visitList(self, node):
         for elt in node.nodes:
             self.visit(elt)
         self.emit('BUILD_LIST', len(node.nodes))
-        return 1
+
+    def visitSliceobj(self, node):
+        for child in node.nodes:
+            self.visit(child)
+        self.emit('BUILD_SLICE', len(node.nodes))
 
     def visitDict(self, node):
+	# XXX is this a good general strategy?  could it be done 
+	# separately from the general visitor
+	lineno = getattr(node, 'lineno', None)
+	if lineno:
+	    self.emit('SET_LINENO', lineno)
         self.emit('BUILD_MAP', 0)
         for k, v in node.items:
-            # XXX need to add set lineno when there aren't constants
+	    lineno2 = getattr(node, 'lineno', None)
+	    if lineno != lineno2:
+		self.emit('SET_LINENO', lineno2)
+		lineno = lineno2
             self.emit('DUP_TOP')
             self.visit(v)
             self.emit('ROT_TWO')
             self.visit(k)
             self.emit('STORE_SUBSCR')
-        return 1
 
-    def visitReturn(self, node):
-        self.emit('SET_LINENO', node.lineno)
-        self.visit(node.value)
-        self.emit('RETURN_VALUE')
-        return 1
+class ModuleCodeGenerator(CodeGenerator):
+    super_init = CodeGenerator.__init__
+    
+    def __init__(self, filename):
+	# XXX <module> is ? in compile.c
+	self.graph = pyassem.PyFlowGraph("<module>", filename)
+	self.super_init(filename)
+
+class FunctionCodeGenerator(CodeGenerator):
+    super_init = CodeGenerator.__init__
+
+    optimized = 1
+    lambdaCount = 0
+
+    def __init__(self, func, filename, isLambda=0):
+        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, filename, args, 
+					   optimized=1) 
+	self.isLambda = isLambda
+	self.super_init(filename)
 
-    def visitRaise(self, node):
-        self.emit('SET_LINENO', node.lineno)
-        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)
-        return 1
+        lnf = walk(func.code, LocalNameFinder(args), 0)
+        self.locals.push(lnf.getLocals())
+	if func.varargs:
+	    self.graph.setFlag(CO_VARARGS)
+	if func.kwargs:
+	    self.graph.setFlag(CO_VARKEYWORDS)
+        self.emit('SET_LINENO', func.lineno)
+        if hasTupleArg:
+            self.generateArgUnpack(func.argnames)
 
-    def visitPrint(self, node):
-        self.emit('SET_LINENO', node.lineno)
-        for child in node.nodes:
-            self.visit(child)
-            self.emit('PRINT_ITEM')
-        return 1
+    def finish(self):
+	self.graph.startExitBlock()
+	if not self.isLambda:
+	    self.emit('LOAD_CONST', None)
+	self.emit('RETURN_VALUE')
 
-    def visitPrintnl(self, node):
-        self.visitPrint(node)
-        self.emit('PRINT_NEWLINE')
-        return 1
+    def generateArgUnpack(self, args):
+        count = 0
+        for arg in args:
+            if type(arg) == types.TupleType:
+                self.emit('LOAD_FAST', '.nested%d' % count)
+                count = count + 1
+                self.unpackTuple(arg)
+                        
+    def unpackTuple(self, tup):
+        self.emit('UNPACK_TUPLE', len(tup))
+        for elt in tup:
+            if type(elt) == types.TupleType:
+                self.unpackTuple(elt)
+            else:
+                self.emit('STORE_FAST', elt)
 
-    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')
-        return 1
+class ClassCodeGenerator(CodeGenerator):
+    super_init = CodeGenerator.__init__
+
+    def __init__(self, klass, filename):
+	self.graph = pyassem.PyFlowGraph(klass.name, filename,
+					   optimized=0)
+        self.super_init(filename)
+        lnf = walk(klass.code, LocalNameFinder(), 0)
+        self.locals.push(lnf.getLocals())
+
+    def finish(self):
+	self.graph.startExitBlock()
+        self.emit('LOAD_LOCALS')
+	self.emit('RETURN_VALUE')
+
+
+def generateArgList(arglist):
+    """Generate an arg list marking TupleArgs"""
+    args = []
+    extra = []
+    count = 0
+    for elt in arglist:
+	if type(elt) == types.StringType:
+	    args.append(elt)
+	elif type(elt) == types.TupleType:
+	    args.append(TupleArg(count, elt))
+	    count = count + 1
+	    extra.extend(misc.flatten(elt))
+	else:
+	    raise ValueError, "unexpect argument type:", elt
+    return args + extra, count
 
 class LocalNameFinder:
+    """Find local names in scope"""
     def __init__(self, names=()):
         self.names = misc.Set()
         self.globals = misc.Set()
@@ -720,25 +739,23 @@ class LocalNameFinder:
             self.names.add(name)
 
     def getLocals(self):
-        for elt in self.globals.items():
+        for elt in self.globals.elements():
             if self.names.has_elt(elt):
                 self.names.remove(elt)
         return self.names
 
     def visitDict(self, node):
-        return 1
+	pass
 
     def visitGlobal(self, node):
         for name in node.names:
             self.globals.add(name)
-        return 1
 
     def visitFunction(self, node):
         self.names.add(node.name)
-        return 1
 
     def visitLambda(self, node):
-        return 1
+	pass
 
     def visitImport(self, node):
         for name in node.names:
@@ -750,11 +767,16 @@ class LocalNameFinder:
 
     def visitClass(self, node):
         self.names.add(node.name)
-        return 1
 
     def visitAssName(self, node):
         self.names.add(node.name)
 
+def findOp(node):
+    """Find the op (DELETE, LOAD, STORE) in an AssTuple tree"""
+    v = OpFinder()
+    walk(node, v, 0)
+    return v.op
+
 class OpFinder:
     def __init__(self):
         self.op = None
@@ -764,57 +786,8 @@ class OpFinder:
         elif self.op != node.flags:
             raise ValueError, "mixed ops in stmt"
 
-def findOp(node):
-    v = OpFinder()
-    walk(node, v)
-    return v.op
-
-class Loop:
-    def __init__(self):
-        self.startAnchor = StackRef()
-        self.breakAnchor = StackRef()
-        self.extentAnchor = StackRef()
-
-class CompiledModule:
-    """Store the code object for a compiled module
-
-    XXX Not clear how the code objects will be stored.  Seems possible
-    that a single code attribute is sufficient, because it will
-    contains references to all the need code objects.  That might be
-    messy, though.
-    """
-    MAGIC = (20121 | (ord('\r')<<16) | (ord('\n')<<24))
-
-    def __init__(self, source, filename):
-        self.source = source
-        self.filename = filename
+if __name__ == "__main__":
+    import sys
 
-    def compile(self):
-	self.ast = parse(self.source)
-        cg = CodeGenerator(self.filename)
-        walk(self.ast, cg)
-        self.code = cg.asConst()
-
-    def dump(self, path):
-        """create a .pyc file"""
-        f = open(path, 'wb')
-        f.write(self._pyc_header())
-        marshal.dump(self.code, f)
-        f.close()
-        
-    def _pyc_header(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.
-        magic = marshal.dumps(self.MAGIC)[1:]
-        mtime = os.stat(self.filename)[stat.ST_MTIME]
-        mtime = struct.pack('i', mtime)
-        return magic + mtime
-
-def compile(filename):
-    buf = open(filename).read()
-    mod = CompiledModule(buf, filename)
-    mod.compile()
-    mod.dump(filename + 'c')
-        
+    for file in sys.argv[1:]:
+	compile(file)