cpython/Lib/compiler/pycodegen.py

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import imp
import os
import marshal
import stat
import string
import struct
import sys
import types
from cStringIO import StringIO
from compiler import ast, parse, walk
from compiler import pyassem, misc
from compiler.pyassem import CO_VARARGS, CO_VARKEYWORDS, CO_NEWLOCALS, TupleArg
# Do we have Python 1.x or Python 2.x?
try:
VERSION = sys.version_info[0]
except AttributeError:
VERSION = 1
callfunc_opcode_info = {
# (Have *args, Have **args) : opcode
(0,0) : "CALL_FUNCTION",
(1,0) : "CALL_FUNCTION_VAR",
(0,1) : "CALL_FUNCTION_KW",
(1,1) : "CALL_FUNCTION_VAR_KW",
}
def compile(filename, display=0):
f = open(filename)
buf = f.read()
f.close()
mod = Module(buf, filename)
mod.compile(display)
f = open(filename + "c", "wb")
mod.dump(f)
f.close()
class Module:
def __init__(self, source, filename):
self.filename = filename
self.source = source
self.code = None
def compile(self, display=0):
ast = parse(self.source)
root, filename = os.path.split(self.filename)
gen = ModuleCodeGenerator(filename)
walk(ast, gen, 1)
if display:
import pprint
print pprint.pprint(ast)
self.code = gen.getCode()
def dump(self, f):
f.write(self.getPycHeader())
marshal.dump(self.code, f)
MAGIC = imp.get_magic()
def getPycHeader(self):
# compile.c uses marshal to write a long directly, with
# calling the interface that would also generate a 1-byte code
# to indicate the type of the value. simplest way to get the
# same effect is to call marshal and then skip the code.
mtime = os.stat(self.filename)[stat.ST_MTIME]
mtime = struct.pack('i', mtime)
return self.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, e.g.
## self.graph = pyassem.PyFlowGraph()
self.filename = filename
self.locals = misc.Stack()
self.loops = misc.Stack()
self.curStack = 0
self.maxStack = 0
self.last_lineno = None
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 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 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):
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 set_lineno(self, node):
"""Emit SET_LINENO if node has lineno attribute and it is
different than the last lineno emitted.
Returns true if SET_LINENO was emitted.
There are no rules for when an AST node should have a lineno
attribute. The transformer and AST code need to be reviewed
and a consistent policy implemented and documented. Until
then, this method works around missing line numbers.
"""
lineno = getattr(node, 'lineno', None)
if lineno is not None and lineno != self.last_lineno:
self.emit('SET_LINENO', lineno)
self.last_lineno = lineno
return 1
return 0
# 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.setDocstring(node.doc)
self.visit(node.node)
self.emit('LOAD_CONST', None)
self.emit('RETURN_VALUE')
def visitFunction(self, node):
self._visitFuncOrLambda(node, isLambda=0)
self.storeName(node.name)
def visitLambda(self, node):
self._visitFuncOrLambda(node, isLambda=1)
def _visitFuncOrLambda(self, node, isLambda):
gen = FunctionCodeGenerator(node, self.filename, isLambda)
walk(node.code, gen)
gen.finish()
self.set_lineno(node)
for default in node.defaults:
self.visit(default)
self.emit('LOAD_CONST', gen)
self.emit('MAKE_FUNCTION', len(node.defaults))
def visitClass(self, node):
gen = ClassCodeGenerator(node, self.filename)
walk(node.code, gen)
gen.finish()
self.set_lineno(node)
self.emit('LOAD_CONST', node.name)
for base in node.bases:
self.visit(base)
self.emit('BUILD_TUPLE', len(node.bases))
self.emit('LOAD_CONST', gen.getCode())
self.emit('MAKE_FUNCTION', 0)
self.emit('CALL_FUNCTION', 0)
self.emit('BUILD_CLASS')
self.storeName(node.name)
# The rest are standard visitor methods
# The next few implement control-flow statements
def visitIf(self, node):
end = self.newBlock()
numtests = len(node.tests)
for i in range(numtests):
test, suite = node.tests[i]
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.loops.push(loop)
self.set_lineno(node)
self.visit(node.test)
self.emit('JUMP_IF_FALSE', else_ or after)
self.nextBlock()
self.emit('POP_TOP')
self.visit(node.body)
self.emit('JUMP_ABSOLUTE', loop)
self.startBlock(else_) # or just the POPs if not else clause
self.emit('POP_TOP')
self.emit('POP_BLOCK')
if node.else_:
self.visit(node.else_)
self.loops.pop()
self.nextBlock(after)
def visitFor(self, node):
start = self.newBlock()
anchor = self.newBlock()
after = self.newBlock()
self.loops.push(start)
self.set_lineno(node)
self.emit('SETUP_LOOP', after)
self.visit(node.list)
self.visit(ast.Const(0))
self.nextBlock(start)
self.set_lineno(node)
self.emit('FOR_LOOP', anchor)
self.nextBlock()
self.visit(node.assign)
self.visit(node.body)
self.emit('JUMP_ABSOLUTE', start)
self.startBlock(anchor)
self.emit('POP_BLOCK')
if node.else_:
self.visit(node.else_)
self.loops.pop()
self.nextBlock(after)
def visitBreak(self, node):
if not self.loops:
raise SyntaxError, "'break' outside loop (%s, %d)" % \
(self.filename, node.lineno)
self.set_lineno(node)
self.emit('BREAK_LOOP')
def visitContinue(self, node):
if not self.loops:
raise SyntaxError, "'continue' outside loop (%s, %d)" % \
(self.filename, node.lineno)
l = self.loops.top()
self.set_lineno(node)
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.startBlock(cleanup)
self.emit('ROT_TWO')
self.emit('POP_TOP')
self.nextBlock(end)
# list comprehensions
__list_count = 0
def visitListComp(self, node):
# XXX would it be easier to transform the AST into the form it
# would have if the list comp were expressed as a series of
# for and if stmts and an explicit append?
self.set_lineno(node)
# setup list
append = "$append%d" % self.__list_count
self.__list_count = self.__list_count + 1
self.emit('BUILD_LIST', 0)
self.emit('DUP_TOP')
self.emit('LOAD_ATTR', 'append')
self.storeName(append)
l = len(node.quals)
stack = []
for i, for_ in zip(range(l), 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.loadName(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.delName(append)
self.__list_count = self.__list_count - 1
def visitListCompFor(self, node):
self.set_lineno(node)
start = self.newBlock()
anchor = self.newBlock()
self.visit(node.list)
self.visit(ast.Const(0))
self.emit('SET_LINENO', node.lineno)
self.nextBlock(start)
self.emit('FOR_LOOP', anchor)
self.nextBlock()
self.visit(node.assign)
return start, anchor
def visitListCompIf(self, node, branch):
self.set_lineno(node)
self.visit(node.test)
self.emit('JUMP_IF_FALSE', branch)
self.newBlock()
self.emit('POP_TOP')
# exception related
def visitAssert(self, node):
# XXX would be interesting to implement this via a
# transformation of the AST before this stage
end = self.newBlock()
self.set_lineno(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.
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('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):
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()
self.visit(node.body)
self.emit('POP_BLOCK')
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()
self.emit('POP_TOP')
self.emit('END_FINALLY')
if node.else_:
self.nextBlock(lElse)
self.visit(node.else_)
self.nextBlock(end)
def visitTryFinally(self, node):
final = self.newBlock()
self.set_lineno(node)
self.emit('SETUP_FINALLY', final)
self.nextBlock()
self.visit(node.body)
self.emit('POP_BLOCK')
self.emit('LOAD_CONST', None)
self.nextBlock(final)
self.visit(node.final)
self.emit('END_FINALLY')
# misc
def visitDiscard(self, node):
self.visit(node.expr)
self.emit('POP_TOP')
def visitConst(self, node):
self.emit('LOAD_CONST', node.value)
def visitKeyword(self, node):
self.emit('LOAD_CONST', node.name)
self.visit(node.expr)
def visitGlobal(self, node):
# no code to generate
pass
def visitName(self, node):
self.set_lineno(node)
self.loadName(node.name)
def visitPass(self, node):
self.set_lineno(node)
def visitImport(self, node):
self.set_lineno(node)
for name, alias in node.names:
if VERSION > 1:
self.emit('LOAD_CONST', None)
self.emit('IMPORT_NAME', name)
mod = string.split(name, ".")[0]
self.storeName(alias or mod)
def visitFrom(self, node):
self.set_lineno(node)
fromlist = map(lambda (name, alias): name, 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')
# There can only be one name w/ from ... import *
assert len(node.names) == 1
return
else:
self.emit('IMPORT_FROM', name)
self._resolveDots(name)
self.storeName(alias or name)
else:
self.emit('IMPORT_FROM', name)
self.emit('POP_TOP')
def _resolveDots(self, name):
elts = string.split(name, ".")
if len(elts) == 1:
return
for elt in elts[1:]:
self.emit('LOAD_ATTR', elt)
def visitGetattr(self, node):
self.visit(node.expr)
self.emit('LOAD_ATTR', node.attrname)
# next five implement assignments
def visitAssign(self, node):
self.set_lineno(node)
self.visit(node.expr)
dups = len(node.nodes) - 1
for i in range(len(node.nodes)):
elt = node.nodes[i]
if i < dups:
self.emit('DUP_TOP')
if isinstance(elt, ast.Node):
self.visit(elt)
def visitAssName(self, node):
if node.flags == 'OP_ASSIGN':
self.storeName(node.name)
elif node.flags == 'OP_DELETE':
self.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', node.attrname)
elif node.flags == 'OP_DELETE':
self.emit('DELETE_ATTR', node.attrname)
else:
print "warning: unexpected flags:", node.flags
print node
def _visitAssSequence(self, node, op='UNPACK_SEQUENCE'):
if findOp(node) != 'OP_DELETE':
self.emit(op, len(node.nodes))
for child in node.nodes:
self.visit(child)
if VERSION > 1:
visitAssTuple = _visitAssSequence
visitAssList = _visitAssSequence
else:
def visitAssTuple(self, node):
self._visitAssSequence(node, 'UNPACK_TUPLE')
def visitAssList(self, node):
self._visitAssSequence(node, 'UNPACK_LIST')
# augmented assignment
def visitAugAssign(self, node):
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_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', node.attrname)
elif mode == "store":
self.emit('ROT_TWO')
self.emit('STORE_ATTR', 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
else:
pos = pos + 1
if node.star_args is not None:
self.visit(node.star_args)
if node.dstar_args is not None:
self.visit(node.dstar_args)
have_star = node.star_args is not None
have_dstar = node.dstar_args is not None
opcode = callfunc_opcode_info[have_star, have_dstar]
self.emit(opcode, kw << 8 | pos)
def visitPrint(self, node):
self.set_lineno(node)
if node.dest:
self.visit(node.dest)
for child in node.nodes:
if node.dest:
self.emit('DUP_TOP')
self.visit(child)
if node.dest:
self.emit('ROT_TWO')
self.emit('PRINT_ITEM_TO')
else:
self.emit('PRINT_ITEM')
def visitPrintnl(self, node):
self.visitPrint(node)
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')
# slice and subscript stuff
def visitSlice(self, node, aug_flag=None):
# aug_flag is used by visitAugSlice
self.visit(node.expr)
slice = 0
if node.lower:
self.visit(node.lower)
slice = slice | 1
if node.upper:
self.visit(node.upper)
slice = slice | 2
if aug_flag:
if slice == 0:
self.emit('DUP_TOP')
elif slice == 3:
self.emit('DUP_TOPX', 3)
else:
self.emit('DUP_TOPX', 2)
if node.flags == 'OP_APPLY':
self.emit('SLICE+%d' % slice)
elif node.flags == 'OP_ASSIGN':
self.emit('STORE_SLICE+%d' % slice)
elif node.flags == 'OP_DELETE':
self.emit('DELETE_SLICE+%d' % slice)
else:
print "weird slice", node.flags
raise
def visitSubscript(self, node, aug_flag=None):
self.visit(node.expr)
for sub in node.subs:
self.visit(sub)
if 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')
# binary ops
def binaryOp(self, node, op):
self.visit(node.left)
self.visit(node.right)
self.emit(op)
def visitAdd(self, node):
return self.binaryOp(node, 'BINARY_ADD')
def visitSub(self, node):
return self.binaryOp(node, 'BINARY_SUBTRACT')
def visitMul(self, node):
return self.binaryOp(node, 'BINARY_MULTIPLY')
def visitDiv(self, node):
return self.binaryOp(node, 'BINARY_DIVIDE')
def visitMod(self, node):
return self.binaryOp(node, 'BINARY_MODULO')
def visitPower(self, node):
return self.binaryOp(node, 'BINARY_POWER')
def visitLeftShift(self, node):
return self.binaryOp(node, 'BINARY_LSHIFT')
def visitRightShift(self, node):
return self.binaryOp(node, 'BINARY_RSHIFT')
# unary ops
def unaryOp(self, node, op):
self.visit(node.expr)
self.emit(op)
def visitInvert(self, node):
return self.unaryOp(node, 'UNARY_INVERT')
def visitUnarySub(self, node):
return self.unaryOp(node, 'UNARY_NEGATIVE')
def visitUnaryAdd(self, node):
return self.unaryOp(node, 'UNARY_POSITIVE')
def visitUnaryInvert(self, node):
return self.unaryOp(node, 'UNARY_INVERT')
def visitNot(self, node):
return self.unaryOp(node, 'UNARY_NOT')
def visitBackquote(self, node):
return self.unaryOp(node, 'UNARY_CONVERT')
# bit ops
def bitOp(self, nodes, op):
self.visit(nodes[0])
for node in nodes[1:]:
self.visit(node)
self.emit(op)
def visitBitand(self, node):
return self.bitOp(node.nodes, 'BINARY_AND')
def visitBitor(self, node):
return self.bitOp(node.nodes, 'BINARY_OR')
def visitBitxor(self, node):
return self.bitOp(node.nodes, 'BINARY_XOR')
# object constructors
def visitEllipsis(self, node):
self.emit('LOAD_CONST', Ellipsis)
def visitTuple(self, node):
for elt in node.nodes:
self.visit(elt)
self.emit('BUILD_TUPLE', len(node.nodes))
def visitList(self, 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):
lineno = getattr(node, 'lineno', None)
if lineno:
set.emit('SET_LINENO', lineno)
self.emit('BUILD_MAP', 0)
for k, v in node.items:
lineno2 = getattr(node, 'lineno', None)
if lineno2 is not None and 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')
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)
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.set_lineno(func)
if hasTupleArg:
self.generateArgUnpack(func.argnames)
def finish(self):
self.graph.startExitBlock()
if not self.isLambda:
self.emit('LOAD_CONST', None)
self.emit('RETURN_VALUE')
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.unpackSequence(arg)
def unpackSequence(self, tup):
if VERSION > 1:
self.emit('UNPACK_SEQUENCE', len(tup))
else:
self.emit('UNPACK_TUPLE', len(tup))
for elt in tup:
if type(elt) == types.TupleType:
self.unpackSequence(elt)
else:
self.emit('STORE_FAST', elt)
unpackTuple = unpackSequence
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())
self.graph.setFlag(CO_NEWLOCALS)
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()
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)
return self.names
def visitDict(self, node):
pass
def visitGlobal(self, node):
for name in node.names:
self.globals.add(name)
def visitFunction(self, node):
self.names.add(node.name)
def visitLambda(self, node):
pass
def visitImport(self, node):
for name, alias in node.names:
self.names.add(alias or name)
def visitFrom(self, node):
for name, alias in node.names:
self.names.add(alias or name)
def visitClass(self, node):
self.names.add(node.name)
def visitAssName(self, node):
self.names.add(node.name)
def 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
def visitAssName(self, node):
if self.op is None:
self.op = node.flags
elif self.op != node.flags:
raise ValueError, "mixed ops in stmt"
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__":
import sys
for file in sys.argv[1:]:
compile(file)