ref: dc96f164a2b72ccb209ae98ce50a11087cbe44f8
dir: /sys/lib/python/compiler/pycodegen.py/
import imp
import os
import marshal
import struct
import sys
from cStringIO import StringIO
from compiler import ast, parse, walk, syntax
from compiler import pyassem, misc, future, symbols
from compiler.consts import SC_LOCAL, SC_GLOBAL, SC_FREE, SC_CELL
from compiler.consts import (CO_VARARGS, CO_VARKEYWORDS, CO_NEWLOCALS,
CO_NESTED, CO_GENERATOR, CO_FUTURE_DIVISION,
CO_FUTURE_ABSIMPORT, CO_FUTURE_WITH_STATEMENT)
from compiler.pyassem import TupleArg
# XXX The version-specific code can go, since this code only works with 2.x.
# Do we have Python 1.x or Python 2.x?
try:
VERSION = sys.version_info[0]
except AttributeError:
VERSION = 1
callfunc_opcode_info = {
# (Have *args, Have **args) : opcode
(0,0) : "CALL_FUNCTION",
(1,0) : "CALL_FUNCTION_VAR",
(0,1) : "CALL_FUNCTION_KW",
(1,1) : "CALL_FUNCTION_VAR_KW",
}
LOOP = 1
EXCEPT = 2
TRY_FINALLY = 3
END_FINALLY = 4
def compileFile(filename, display=0):
f = open(filename, 'U')
buf = f.read()
f.close()
mod = Module(buf, filename)
try:
mod.compile(display)
except SyntaxError:
raise
else:
f = open(filename + "c", "wb")
mod.dump(f)
f.close()
def compile(source, filename, mode, flags=None, dont_inherit=None):
"""Replacement for builtin compile() function"""
if flags is not None or dont_inherit is not None:
raise RuntimeError, "not implemented yet"
if mode == "single":
gen = Interactive(source, filename)
elif mode == "exec":
gen = Module(source, filename)
elif mode == "eval":
gen = Expression(source, filename)
else:
raise ValueError("compile() 3rd arg must be 'exec' or "
"'eval' or 'single'")
gen.compile()
return gen.code
class AbstractCompileMode:
mode = None # defined by subclass
def __init__(self, source, filename):
self.source = source
self.filename = filename
self.code = None
def _get_tree(self):
tree = parse(self.source, self.mode)
misc.set_filename(self.filename, tree)
syntax.check(tree)
return tree
def compile(self):
pass # implemented by subclass
def getCode(self):
return self.code
class Expression(AbstractCompileMode):
mode = "eval"
def compile(self):
tree = self._get_tree()
gen = ExpressionCodeGenerator(tree)
self.code = gen.getCode()
class Interactive(AbstractCompileMode):
mode = "single"
def compile(self):
tree = self._get_tree()
gen = InteractiveCodeGenerator(tree)
self.code = gen.getCode()
class Module(AbstractCompileMode):
mode = "exec"
def compile(self, display=0):
tree = self._get_tree()
gen = ModuleCodeGenerator(tree)
if display:
import pprint
print pprint.pprint(tree)
self.code = gen.getCode()
def dump(self, f):
f.write(self.getPycHeader())
marshal.dump(self.code, f)
MAGIC = imp.get_magic()
def getPycHeader(self):
# compile.c uses marshal to write a long directly, with
# calling the interface that would also generate a 1-byte code
# to indicate the type of the value. simplest way to get the
# same effect is to call marshal and then skip the code.
mtime = os.path.getmtime(self.filename)
mtime = struct.pack('<i', mtime)
return self.MAGIC + mtime
class LocalNameFinder:
"""Find local names in scope"""
def __init__(self, names=()):
self.names = misc.Set()
self.globals = misc.Set()
for name in names:
self.names.add(name)
# XXX list comprehensions and for loops
def getLocals(self):
for elt in self.globals.elements():
if self.names.has_elt(elt):
self.names.remove(elt)
return self.names
def visitDict(self, node):
pass
def visitGlobal(self, node):
for name in node.names:
self.globals.add(name)
def visitFunction(self, node):
self.names.add(node.name)
def visitLambda(self, node):
pass
def visitImport(self, node):
for name, alias in node.names:
self.names.add(alias or name)
def visitFrom(self, node):
for name, alias in node.names:
self.names.add(alias or name)
def visitClass(self, node):
self.names.add(node.name)
def visitAssName(self, node):
self.names.add(node.name)
def is_constant_false(node):
if isinstance(node, ast.Const):
if not node.value:
return 1
return 0
class CodeGenerator:
"""Defines basic code generator for Python bytecode
This class is an abstract base class. Concrete subclasses must
define an __init__() that defines self.graph and then calls the
__init__() defined in this class.
The concrete class must also define the class attributes
NameFinder, FunctionGen, and ClassGen. These attributes can be
defined in the initClass() method, which is a hook for
initializing these methods after all the classes have been
defined.
"""
optimized = 0 # is namespace access optimized?
__initialized = None
class_name = None # provide default for instance variable
def __init__(self):
if self.__initialized is None:
self.initClass()
self.__class__.__initialized = 1
self.checkClass()
self.locals = misc.Stack()
self.setups = misc.Stack()
self.last_lineno = None
self._setupGraphDelegation()
self._div_op = "BINARY_DIVIDE"
# XXX set flags based on future features
futures = self.get_module().futures
for feature in futures:
if feature == "division":
self.graph.setFlag(CO_FUTURE_DIVISION)
self._div_op = "BINARY_TRUE_DIVIDE"
elif feature == "absolute_import":
self.graph.setFlag(CO_FUTURE_ABSIMPORT)
elif feature == "with_statement":
self.graph.setFlag(CO_FUTURE_WITH_STATEMENT)
def initClass(self):
"""This method is called once for each class"""
def checkClass(self):
"""Verify that class is constructed correctly"""
try:
assert hasattr(self, 'graph')
assert getattr(self, 'NameFinder')
assert getattr(self, 'FunctionGen')
assert getattr(self, 'ClassGen')
except AssertionError, msg:
intro = "Bad class construction for %s" % self.__class__.__name__
raise AssertionError, intro
def _setupGraphDelegation(self):
self.emit = self.graph.emit
self.newBlock = self.graph.newBlock
self.startBlock = self.graph.startBlock
self.nextBlock = self.graph.nextBlock
self.setDocstring = self.graph.setDocstring
def getCode(self):
"""Return a code object"""
return self.graph.getCode()
def mangle(self, name):
if self.class_name is not None:
return misc.mangle(name, self.class_name)
else:
return name
def parseSymbols(self, tree):
s = symbols.SymbolVisitor()
walk(tree, s)
return s.scopes
def get_module(self):
raise RuntimeError, "should be implemented by subclasses"
# Next five methods handle name access
def isLocalName(self, name):
return self.locals.top().has_elt(name)
def storeName(self, name):
self._nameOp('STORE', name)
def loadName(self, name):
self._nameOp('LOAD', name)
def delName(self, name):
self._nameOp('DELETE', name)
def _nameOp(self, prefix, name):
name = self.mangle(name)
scope = self.scope.check_name(name)
if scope == SC_LOCAL:
if not self.optimized:
self.emit(prefix + '_NAME', name)
else:
self.emit(prefix + '_FAST', name)
elif scope == SC_GLOBAL:
if not self.optimized:
self.emit(prefix + '_NAME', name)
else:
self.emit(prefix + '_GLOBAL', name)
elif scope == SC_FREE or scope == SC_CELL:
self.emit(prefix + '_DEREF', name)
else:
raise RuntimeError, "unsupported scope for var %s: %d" % \
(name, scope)
def _implicitNameOp(self, prefix, name):
"""Emit name ops for names generated implicitly by for loops
The interpreter generates names that start with a period or
dollar sign. The symbol table ignores these names because
they aren't present in the program text.
"""
if self.optimized:
self.emit(prefix + '_FAST', name)
else:
self.emit(prefix + '_NAME', name)
# The set_lineno() function and the explicit emit() calls for
# SET_LINENO below are only used to generate the line number table.
# As of Python 2.3, the interpreter does not have a SET_LINENO
# instruction. pyassem treats SET_LINENO opcodes as a special case.
def set_lineno(self, node, force=False):
"""Emit SET_LINENO if necessary.
The instruction is considered necessary if the node has a
lineno attribute and it is different than the last lineno
emitted.
Returns true if SET_LINENO was emitted.
There are no rules for when an AST node should have a lineno
attribute. The transformer and AST code need to be reviewed
and a consistent policy implemented and documented. Until
then, this method works around missing line numbers.
"""
lineno = getattr(node, 'lineno', None)
if lineno is not None and (lineno != self.last_lineno
or force):
self.emit('SET_LINENO', lineno)
self.last_lineno = lineno
return True
return False
# The first few visitor methods handle nodes that generator new
# code objects. They use class attributes to determine what
# specialized code generators to use.
NameFinder = LocalNameFinder
FunctionGen = None
ClassGen = None
def visitModule(self, node):
self.scopes = self.parseSymbols(node)
self.scope = self.scopes[node]
self.emit('SET_LINENO', 0)
if node.doc:
self.emit('LOAD_CONST', node.doc)
self.storeName('__doc__')
lnf = walk(node.node, self.NameFinder(), verbose=0)
self.locals.push(lnf.getLocals())
self.visit(node.node)
self.emit('LOAD_CONST', None)
self.emit('RETURN_VALUE')
def visitExpression(self, node):
self.set_lineno(node)
self.scopes = self.parseSymbols(node)
self.scope = self.scopes[node]
self.visit(node.node)
self.emit('RETURN_VALUE')
def visitFunction(self, node):
self._visitFuncOrLambda(node, isLambda=0)
if node.doc:
self.setDocstring(node.doc)
self.storeName(node.name)
def visitLambda(self, node):
self._visitFuncOrLambda(node, isLambda=1)
def _visitFuncOrLambda(self, node, isLambda=0):
if not isLambda and node.decorators:
for decorator in node.decorators.nodes:
self.visit(decorator)
ndecorators = len(node.decorators.nodes)
else:
ndecorators = 0
gen = self.FunctionGen(node, self.scopes, isLambda,
self.class_name, self.get_module())
walk(node.code, gen)
gen.finish()
self.set_lineno(node)
for default in node.defaults:
self.visit(default)
self._makeClosure(gen, len(node.defaults))
for i in range(ndecorators):
self.emit('CALL_FUNCTION', 1)
def visitClass(self, node):
gen = self.ClassGen(node, self.scopes,
self.get_module())
walk(node.code, gen)
gen.finish()
self.set_lineno(node)
self.emit('LOAD_CONST', node.name)
for base in node.bases:
self.visit(base)
self.emit('BUILD_TUPLE', len(node.bases))
self._makeClosure(gen, 0)
self.emit('CALL_FUNCTION', 0)
self.emit('BUILD_CLASS')
self.storeName(node.name)
# The rest are standard visitor methods
# The next few implement control-flow statements
def visitIf(self, node):
end = self.newBlock()
numtests = len(node.tests)
for i in range(numtests):
test, suite = node.tests[i]
if is_constant_false(test):
# XXX will need to check generator stuff here
continue
self.set_lineno(test)
self.visit(test)
nextTest = self.newBlock()
self.emit('JUMP_IF_FALSE', nextTest)
self.nextBlock()
self.emit('POP_TOP')
self.visit(suite)
self.emit('JUMP_FORWARD', end)
self.startBlock(nextTest)
self.emit('POP_TOP')
if node.else_:
self.visit(node.else_)
self.nextBlock(end)
def visitWhile(self, node):
self.set_lineno(node)
loop = self.newBlock()
else_ = self.newBlock()
after = self.newBlock()
self.emit('SETUP_LOOP', after)
self.nextBlock(loop)
self.setups.push((LOOP, loop))
self.set_lineno(node, force=True)
self.visit(node.test)
self.emit('JUMP_IF_FALSE', else_ or after)
self.nextBlock()
self.emit('POP_TOP')
self.visit(node.body)
self.emit('JUMP_ABSOLUTE', loop)
self.startBlock(else_) # or just the POPs if not else clause
self.emit('POP_TOP')
self.emit('POP_BLOCK')
self.setups.pop()
if node.else_:
self.visit(node.else_)
self.nextBlock(after)
def visitFor(self, node):
start = self.newBlock()
anchor = self.newBlock()
after = self.newBlock()
self.setups.push((LOOP, start))
self.set_lineno(node)
self.emit('SETUP_LOOP', after)
self.visit(node.list)
self.emit('GET_ITER')
self.nextBlock(start)
self.set_lineno(node, force=1)
self.emit('FOR_ITER', anchor)
self.visit(node.assign)
self.visit(node.body)
self.emit('JUMP_ABSOLUTE', start)
self.nextBlock(anchor)
self.emit('POP_BLOCK')
self.setups.pop()
if node.else_:
self.visit(node.else_)
self.nextBlock(after)
def visitBreak(self, node):
if not self.setups:
raise SyntaxError, "'break' outside loop (%s, %d)" % \
(node.filename, node.lineno)
self.set_lineno(node)
self.emit('BREAK_LOOP')
def visitContinue(self, node):
if not self.setups:
raise SyntaxError, "'continue' outside loop (%s, %d)" % \
(node.filename, node.lineno)
kind, block = self.setups.top()
if kind == LOOP:
self.set_lineno(node)
self.emit('JUMP_ABSOLUTE', block)
self.nextBlock()
elif kind == EXCEPT or kind == TRY_FINALLY:
self.set_lineno(node)
# find the block that starts the loop
top = len(self.setups)
while top > 0:
top = top - 1
kind, loop_block = self.setups[top]
if kind == LOOP:
break
if kind != LOOP:
raise SyntaxError, "'continue' outside loop (%s, %d)" % \
(node.filename, node.lineno)
self.emit('CONTINUE_LOOP', loop_block)
self.nextBlock()
elif kind == END_FINALLY:
msg = "'continue' not allowed inside 'finally' clause (%s, %d)"
raise SyntaxError, msg % (node.filename, node.lineno)
def visitTest(self, node, jump):
end = self.newBlock()
for child in node.nodes[:-1]:
self.visit(child)
self.emit(jump, end)
self.nextBlock()
self.emit('POP_TOP')
self.visit(node.nodes[-1])
self.nextBlock(end)
def visitAnd(self, node):
self.visitTest(node, 'JUMP_IF_FALSE')
def visitOr(self, node):
self.visitTest(node, 'JUMP_IF_TRUE')
def visitIfExp(self, node):
endblock = self.newBlock()
elseblock = self.newBlock()
self.visit(node.test)
self.emit('JUMP_IF_FALSE', elseblock)
self.emit('POP_TOP')
self.visit(node.then)
self.emit('JUMP_FORWARD', endblock)
self.nextBlock(elseblock)
self.emit('POP_TOP')
self.visit(node.else_)
self.nextBlock(endblock)
def visitCompare(self, node):
self.visit(node.expr)
cleanup = self.newBlock()
for op, code in node.ops[:-1]:
self.visit(code)
self.emit('DUP_TOP')
self.emit('ROT_THREE')
self.emit('COMPARE_OP', op)
self.emit('JUMP_IF_FALSE', cleanup)
self.nextBlock()
self.emit('POP_TOP')
# now do the last comparison
if node.ops:
op, code = node.ops[-1]
self.visit(code)
self.emit('COMPARE_OP', op)
if len(node.ops) > 1:
end = self.newBlock()
self.emit('JUMP_FORWARD', end)
self.startBlock(cleanup)
self.emit('ROT_TWO')
self.emit('POP_TOP')
self.nextBlock(end)
# list comprehensions
__list_count = 0
def visitListComp(self, node):
self.set_lineno(node)
# setup list
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._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.__list_count = self.__list_count - 1
def visitListCompFor(self, node):
start = self.newBlock()
anchor = self.newBlock()
self.visit(node.list)
self.emit('GET_ITER')
self.nextBlock(start)
self.set_lineno(node, force=True)
self.emit('FOR_ITER', anchor)
self.nextBlock()
self.visit(node.assign)
return start, anchor
def visitListCompIf(self, node, branch):
self.set_lineno(node, force=True)
self.visit(node.test)
self.emit('JUMP_IF_FALSE', branch)
self.newBlock()
self.emit('POP_TOP')
def _makeClosure(self, gen, args):
frees = gen.scope.get_free_vars()
if frees:
for name in frees:
self.emit('LOAD_CLOSURE', name)
self.emit('BUILD_TUPLE', len(frees))
self.emit('LOAD_CONST', gen)
self.emit('MAKE_CLOSURE', args)
else:
self.emit('LOAD_CONST', gen)
self.emit('MAKE_FUNCTION', args)
def visitGenExpr(self, node):
gen = GenExprCodeGenerator(node, self.scopes, self.class_name,
self.get_module())
walk(node.code, gen)
gen.finish()
self.set_lineno(node)
self._makeClosure(gen, 0)
# precomputation of outmost iterable
self.visit(node.code.quals[0].iter)
self.emit('GET_ITER')
self.emit('CALL_FUNCTION', 1)
def visitGenExprInner(self, node):
self.set_lineno(node)
# setup list
stack = []
for i, for_ in zip(range(len(node.quals)), node.quals):
start, anchor, end = self.visit(for_)
cont = None
for if_ in for_.ifs:
if cont is None:
cont = self.newBlock()
self.visit(if_, cont)
stack.insert(0, (start, cont, anchor, end))
self.visit(node.expr)
self.emit('YIELD_VALUE')
self.emit('POP_TOP')
for start, cont, anchor, end in stack:
if cont:
skip_one = self.newBlock()
self.emit('JUMP_FORWARD', skip_one)
self.startBlock(cont)
self.emit('POP_TOP')
self.nextBlock(skip_one)
self.emit('JUMP_ABSOLUTE', start)
self.startBlock(anchor)
self.emit('POP_BLOCK')
self.setups.pop()
self.startBlock(end)
self.emit('LOAD_CONST', None)
def visitGenExprFor(self, node):
start = self.newBlock()
anchor = self.newBlock()
end = self.newBlock()
self.setups.push((LOOP, start))
self.emit('SETUP_LOOP', end)
if node.is_outmost:
self.loadName('.0')
else:
self.visit(node.iter)
self.emit('GET_ITER')
self.nextBlock(start)
self.set_lineno(node, force=True)
self.emit('FOR_ITER', anchor)
self.nextBlock()
self.visit(node.assign)
return start, anchor, end
def visitGenExprIf(self, node, branch):
self.set_lineno(node, force=True)
self.visit(node.test)
self.emit('JUMP_IF_FALSE', branch)
self.newBlock()
self.emit('POP_TOP')
# exception related
def visitAssert(self, node):
# XXX would be interesting to implement this via a
# transformation of the AST before this stage
if __debug__:
end = self.newBlock()
self.set_lineno(node)
# XXX AssertionError appears to be special case -- it is always
# loaded as a global even if there is a local name. I guess this
# is a sort of renaming op.
self.nextBlock()
self.visit(node.test)
self.emit('JUMP_IF_TRUE', end)
self.nextBlock()
self.emit('POP_TOP')
self.emit('LOAD_GLOBAL', 'AssertionError')
if node.fail:
self.visit(node.fail)
self.emit('RAISE_VARARGS', 2)
else:
self.emit('RAISE_VARARGS', 1)
self.nextBlock(end)
self.emit('POP_TOP')
def visitRaise(self, node):
self.set_lineno(node)
n = 0
if node.expr1:
self.visit(node.expr1)
n = n + 1
if node.expr2:
self.visit(node.expr2)
n = n + 1
if node.expr3:
self.visit(node.expr3)
n = n + 1
self.emit('RAISE_VARARGS', n)
def visitTryExcept(self, node):
body = self.newBlock()
handlers = self.newBlock()
end = self.newBlock()
if node.else_:
lElse = self.newBlock()
else:
lElse = end
self.set_lineno(node)
self.emit('SETUP_EXCEPT', handlers)
self.nextBlock(body)
self.setups.push((EXCEPT, body))
self.visit(node.body)
self.emit('POP_BLOCK')
self.setups.pop()
self.emit('JUMP_FORWARD', lElse)
self.startBlock(handlers)
last = len(node.handlers) - 1
for i in range(len(node.handlers)):
expr, target, body = node.handlers[i]
self.set_lineno(expr)
if expr:
self.emit('DUP_TOP')
self.visit(expr)
self.emit('COMPARE_OP', 'exception match')
next = self.newBlock()
self.emit('JUMP_IF_FALSE', next)
self.nextBlock()
self.emit('POP_TOP')
self.emit('POP_TOP')
if target:
self.visit(target)
else:
self.emit('POP_TOP')
self.emit('POP_TOP')
self.visit(body)
self.emit('JUMP_FORWARD', end)
if expr:
self.nextBlock(next)
else:
self.nextBlock()
if expr: # XXX
self.emit('POP_TOP')
self.emit('END_FINALLY')
if node.else_:
self.nextBlock(lElse)
self.visit(node.else_)
self.nextBlock(end)
def visitTryFinally(self, node):
body = self.newBlock()
final = self.newBlock()
self.set_lineno(node)
self.emit('SETUP_FINALLY', final)
self.nextBlock(body)
self.setups.push((TRY_FINALLY, body))
self.visit(node.body)
self.emit('POP_BLOCK')
self.setups.pop()
self.emit('LOAD_CONST', None)
self.nextBlock(final)
self.setups.push((END_FINALLY, final))
self.visit(node.final)
self.emit('END_FINALLY')
self.setups.pop()
__with_count = 0
def visitWith(self, node):
body = self.newBlock()
final = self.newBlock()
exitvar = "$exit%d" % self.__with_count
valuevar = "$value%d" % self.__with_count
self.__with_count += 1
self.set_lineno(node)
self.visit(node.expr)
self.emit('DUP_TOP')
self.emit('LOAD_ATTR', '__exit__')
self._implicitNameOp('STORE', exitvar)
self.emit('LOAD_ATTR', '__enter__')
self.emit('CALL_FUNCTION', 0)
if node.vars is None:
self.emit('POP_TOP')
else:
self._implicitNameOp('STORE', valuevar)
self.emit('SETUP_FINALLY', final)
self.nextBlock(body)
self.setups.push((TRY_FINALLY, body))
if node.vars is not None:
self._implicitNameOp('LOAD', valuevar)
self._implicitNameOp('DELETE', valuevar)
self.visit(node.vars)
self.visit(node.body)
self.emit('POP_BLOCK')
self.setups.pop()
self.emit('LOAD_CONST', None)
self.nextBlock(final)
self.setups.push((END_FINALLY, final))
self._implicitNameOp('LOAD', exitvar)
self._implicitNameOp('DELETE', exitvar)
self.emit('WITH_CLEANUP')
self.emit('END_FINALLY')
self.setups.pop()
self.__with_count -= 1
# misc
def visitDiscard(self, node):
self.set_lineno(node)
self.visit(node.expr)
self.emit('POP_TOP')
def visitConst(self, node):
self.emit('LOAD_CONST', node.value)
def visitKeyword(self, node):
self.emit('LOAD_CONST', node.name)
self.visit(node.expr)
def visitGlobal(self, node):
# no code to generate
pass
def visitName(self, node):
self.set_lineno(node)
self.loadName(node.name)
def visitPass(self, node):
self.set_lineno(node)
def visitImport(self, node):
self.set_lineno(node)
level = 0 if self.graph.checkFlag(CO_FUTURE_ABSIMPORT) else -1
for name, alias in node.names:
if VERSION > 1:
self.emit('LOAD_CONST', level)
self.emit('LOAD_CONST', None)
self.emit('IMPORT_NAME', name)
mod = name.split(".")[0]
if alias:
self._resolveDots(name)
self.storeName(alias)
else:
self.storeName(mod)
def visitFrom(self, node):
self.set_lineno(node)
level = node.level
if level == 0 and not self.graph.checkFlag(CO_FUTURE_ABSIMPORT):
level = -1
fromlist = map(lambda (name, alias): name, node.names)
if VERSION > 1:
self.emit('LOAD_CONST', level)
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 = name.split(".")
if len(elts) == 1:
return
for elt in elts[1:]:
self.emit('LOAD_ATTR', elt)
def visitGetattr(self, node):
self.visit(node.expr)
self.emit('LOAD_ATTR', self.mangle(node.attrname))
# next five implement assignments
def visitAssign(self, node):
self.set_lineno(node)
self.visit(node.expr)
dups = len(node.nodes) - 1
for i in range(len(node.nodes)):
elt = node.nodes[i]
if i < dups:
self.emit('DUP_TOP')
if isinstance(elt, ast.Node):
self.visit(elt)
def visitAssName(self, node):
if node.flags == 'OP_ASSIGN':
self.storeName(node.name)
elif node.flags == 'OP_DELETE':
self.set_lineno(node)
self.delName(node.name)
else:
print "oops", node.flags
def visitAssAttr(self, node):
self.visit(node.expr)
if node.flags == 'OP_ASSIGN':
self.emit('STORE_ATTR', self.mangle(node.attrname))
elif node.flags == 'OP_DELETE':
self.emit('DELETE_ATTR', self.mangle(node.attrname))
else:
print "warning: unexpected flags:", node.flags
print node
def _visitAssSequence(self, node, op='UNPACK_SEQUENCE'):
if findOp(node) != 'OP_DELETE':
self.emit(op, len(node.nodes))
for child in node.nodes:
self.visit(child)
if VERSION > 1:
visitAssTuple = _visitAssSequence
visitAssList = _visitAssSequence
else:
def visitAssTuple(self, node):
self._visitAssSequence(node, 'UNPACK_TUPLE')
def visitAssList(self, node):
self._visitAssSequence(node, 'UNPACK_LIST')
# augmented assignment
def visitAugAssign(self, node):
self.set_lineno(node)
aug_node = wrap_aug(node.node)
self.visit(aug_node, "load")
self.visit(node.expr)
self.emit(self._augmented_opcode[node.op])
self.visit(aug_node, "store")
_augmented_opcode = {
'+=' : 'INPLACE_ADD',
'-=' : 'INPLACE_SUBTRACT',
'*=' : 'INPLACE_MULTIPLY',
'/=' : 'INPLACE_DIVIDE',
'//=': 'INPLACE_FLOOR_DIVIDE',
'%=' : 'INPLACE_MODULO',
'**=': 'INPLACE_POWER',
'>>=': 'INPLACE_RSHIFT',
'<<=': 'INPLACE_LSHIFT',
'&=' : 'INPLACE_AND',
'^=' : 'INPLACE_XOR',
'|=' : 'INPLACE_OR',
}
def visitAugName(self, node, mode):
if mode == "load":
self.loadName(node.name)
elif mode == "store":
self.storeName(node.name)
def visitAugGetattr(self, node, mode):
if mode == "load":
self.visit(node.expr)
self.emit('DUP_TOP')
self.emit('LOAD_ATTR', self.mangle(node.attrname))
elif mode == "store":
self.emit('ROT_TWO')
self.emit('STORE_ATTR', self.mangle(node.attrname))
def visitAugSlice(self, node, mode):
if mode == "load":
self.visitSlice(node, 1)
elif mode == "store":
slice = 0
if node.lower:
slice = slice | 1
if node.upper:
slice = slice | 2
if slice == 0:
self.emit('ROT_TWO')
elif slice == 3:
self.emit('ROT_FOUR')
else:
self.emit('ROT_THREE')
self.emit('STORE_SLICE+%d' % slice)
def visitAugSubscript(self, node, mode):
if mode == "load":
self.visitSubscript(node, 1)
elif mode == "store":
self.emit('ROT_THREE')
self.emit('STORE_SUBSCR')
def visitExec(self, node):
self.visit(node.expr)
if node.locals is None:
self.emit('LOAD_CONST', None)
else:
self.visit(node.locals)
if node.globals is None:
self.emit('DUP_TOP')
else:
self.visit(node.globals)
self.emit('EXEC_STMT')
def visitCallFunc(self, node):
pos = 0
kw = 0
self.set_lineno(node)
self.visit(node.node)
for arg in node.args:
self.visit(arg)
if isinstance(arg, ast.Keyword):
kw = kw + 1
else:
pos = pos + 1
if node.star_args is not None:
self.visit(node.star_args)
if node.dstar_args is not None:
self.visit(node.dstar_args)
have_star = node.star_args is not None
have_dstar = node.dstar_args is not None
opcode = callfunc_opcode_info[have_star, have_dstar]
self.emit(opcode, kw << 8 | pos)
def visitPrint(self, node, newline=0):
self.set_lineno(node)
if node.dest:
self.visit(node.dest)
for child in node.nodes:
if node.dest:
self.emit('DUP_TOP')
self.visit(child)
if node.dest:
self.emit('ROT_TWO')
self.emit('PRINT_ITEM_TO')
else:
self.emit('PRINT_ITEM')
if node.dest and not newline:
self.emit('POP_TOP')
def visitPrintnl(self, node):
self.visitPrint(node, newline=1)
if node.dest:
self.emit('PRINT_NEWLINE_TO')
else:
self.emit('PRINT_NEWLINE')
def visitReturn(self, node):
self.set_lineno(node)
self.visit(node.value)
self.emit('RETURN_VALUE')
def visitYield(self, node):
self.set_lineno(node)
self.visit(node.value)
self.emit('YIELD_VALUE')
# slice and subscript stuff
def visitSlice(self, node, aug_flag=None):
# aug_flag is used by visitAugSlice
self.visit(node.expr)
slice = 0
if node.lower:
self.visit(node.lower)
slice = slice | 1
if node.upper:
self.visit(node.upper)
slice = slice | 2
if aug_flag:
if slice == 0:
self.emit('DUP_TOP')
elif slice == 3:
self.emit('DUP_TOPX', 3)
else:
self.emit('DUP_TOPX', 2)
if node.flags == 'OP_APPLY':
self.emit('SLICE+%d' % slice)
elif node.flags == 'OP_ASSIGN':
self.emit('STORE_SLICE+%d' % slice)
elif node.flags == 'OP_DELETE':
self.emit('DELETE_SLICE+%d' % slice)
else:
print "weird slice", node.flags
raise
def visitSubscript(self, node, aug_flag=None):
self.visit(node.expr)
for sub in node.subs:
self.visit(sub)
if len(node.subs) > 1:
self.emit('BUILD_TUPLE', len(node.subs))
if aug_flag:
self.emit('DUP_TOPX', 2)
if node.flags == 'OP_APPLY':
self.emit('BINARY_SUBSCR')
elif node.flags == 'OP_ASSIGN':
self.emit('STORE_SUBSCR')
elif node.flags == 'OP_DELETE':
self.emit('DELETE_SUBSCR')
# binary ops
def binaryOp(self, node, op):
self.visit(node.left)
self.visit(node.right)
self.emit(op)
def visitAdd(self, node):
return self.binaryOp(node, 'BINARY_ADD')
def visitSub(self, node):
return self.binaryOp(node, 'BINARY_SUBTRACT')
def visitMul(self, node):
return self.binaryOp(node, 'BINARY_MULTIPLY')
def visitDiv(self, node):
return self.binaryOp(node, self._div_op)
def visitFloorDiv(self, node):
return self.binaryOp(node, 'BINARY_FLOOR_DIVIDE')
def visitMod(self, node):
return self.binaryOp(node, 'BINARY_MODULO')
def visitPower(self, node):
return self.binaryOp(node, 'BINARY_POWER')
def visitLeftShift(self, node):
return self.binaryOp(node, 'BINARY_LSHIFT')
def visitRightShift(self, node):
return self.binaryOp(node, 'BINARY_RSHIFT')
# unary ops
def unaryOp(self, node, op):
self.visit(node.expr)
self.emit(op)
def visitInvert(self, node):
return self.unaryOp(node, 'UNARY_INVERT')
def visitUnarySub(self, node):
return self.unaryOp(node, 'UNARY_NEGATIVE')
def visitUnaryAdd(self, node):
return self.unaryOp(node, 'UNARY_POSITIVE')
def visitUnaryInvert(self, node):
return self.unaryOp(node, 'UNARY_INVERT')
def visitNot(self, node):
return self.unaryOp(node, 'UNARY_NOT')
def visitBackquote(self, node):
return self.unaryOp(node, 'UNARY_CONVERT')
# bit ops
def bitOp(self, nodes, op):
self.visit(nodes[0])
for node in nodes[1:]:
self.visit(node)
self.emit(op)
def visitBitand(self, node):
return self.bitOp(node.nodes, 'BINARY_AND')
def visitBitor(self, node):
return self.bitOp(node.nodes, 'BINARY_OR')
def visitBitxor(self, node):
return self.bitOp(node.nodes, 'BINARY_XOR')
# object constructors
def visitEllipsis(self, node):
self.emit('LOAD_CONST', Ellipsis)
def visitTuple(self, node):
self.set_lineno(node)
for elt in node.nodes:
self.visit(elt)
self.emit('BUILD_TUPLE', len(node.nodes))
def visitList(self, node):
self.set_lineno(node)
for elt in node.nodes:
self.visit(elt)
self.emit('BUILD_LIST', len(node.nodes))
def visitSliceobj(self, node):
for child in node.nodes:
self.visit(child)
self.emit('BUILD_SLICE', len(node.nodes))
def visitDict(self, node):
self.set_lineno(node)
self.emit('BUILD_MAP', 0)
for k, v in node.items:
self.emit('DUP_TOP')
self.visit(k)
self.visit(v)
self.emit('ROT_THREE')
self.emit('STORE_SUBSCR')
class NestedScopeMixin:
"""Defines initClass() for nested scoping (Python 2.2-compatible)"""
def initClass(self):
self.__class__.NameFinder = LocalNameFinder
self.__class__.FunctionGen = FunctionCodeGenerator
self.__class__.ClassGen = ClassCodeGenerator
class ModuleCodeGenerator(NestedScopeMixin, CodeGenerator):
__super_init = CodeGenerator.__init__
scopes = None
def __init__(self, tree):
self.graph = pyassem.PyFlowGraph("<module>", tree.filename)
self.futures = future.find_futures(tree)
self.__super_init()
walk(tree, self)
def get_module(self):
return self
class ExpressionCodeGenerator(NestedScopeMixin, CodeGenerator):
__super_init = CodeGenerator.__init__
scopes = None
futures = ()
def __init__(self, tree):
self.graph = pyassem.PyFlowGraph("<expression>", tree.filename)
self.__super_init()
walk(tree, self)
def get_module(self):
return self
class InteractiveCodeGenerator(NestedScopeMixin, CodeGenerator):
__super_init = CodeGenerator.__init__
scopes = None
futures = ()
def __init__(self, tree):
self.graph = pyassem.PyFlowGraph("<interactive>", tree.filename)
self.__super_init()
self.set_lineno(tree)
walk(tree, self)
self.emit('RETURN_VALUE')
def get_module(self):
return self
def visitDiscard(self, node):
# XXX Discard means it's an expression. Perhaps this is a bad
# name.
self.visit(node.expr)
self.emit('PRINT_EXPR')
class AbstractFunctionCode:
optimized = 1
lambdaCount = 0
def __init__(self, func, scopes, isLambda, class_name, mod):
self.class_name = class_name
self.module = mod
if isLambda:
klass = FunctionCodeGenerator
name = "<lambda.%d>" % klass.lambdaCount
klass.lambdaCount = klass.lambdaCount + 1
else:
name = func.name
args, hasTupleArg = generateArgList(func.argnames)
self.graph = pyassem.PyFlowGraph(name, func.filename, args,
optimized=1)
self.isLambda = isLambda
self.super_init()
if not isLambda and func.doc:
self.setDocstring(func.doc)
lnf = walk(func.code, self.NameFinder(args), verbose=0)
self.locals.push(lnf.getLocals())
if func.varargs:
self.graph.setFlag(CO_VARARGS)
if func.kwargs:
self.graph.setFlag(CO_VARKEYWORDS)
self.set_lineno(func)
if hasTupleArg:
self.generateArgUnpack(func.argnames)
def get_module(self):
return self.module
def finish(self):
self.graph.startExitBlock()
if not self.isLambda:
self.emit('LOAD_CONST', None)
self.emit('RETURN_VALUE')
def generateArgUnpack(self, args):
for i in range(len(args)):
arg = args[i]
if isinstance(arg, tuple):
self.emit('LOAD_FAST', '.%d' % (i * 2))
self.unpackSequence(arg)
def unpackSequence(self, tup):
if VERSION > 1:
self.emit('UNPACK_SEQUENCE', len(tup))
else:
self.emit('UNPACK_TUPLE', len(tup))
for elt in tup:
if isinstance(elt, tuple):
self.unpackSequence(elt)
else:
self._nameOp('STORE', elt)
unpackTuple = unpackSequence
class FunctionCodeGenerator(NestedScopeMixin, AbstractFunctionCode,
CodeGenerator):
super_init = CodeGenerator.__init__ # call be other init
scopes = None
__super_init = AbstractFunctionCode.__init__
def __init__(self, func, scopes, isLambda, class_name, mod):
self.scopes = scopes
self.scope = scopes[func]
self.__super_init(func, scopes, isLambda, class_name, mod)
self.graph.setFreeVars(self.scope.get_free_vars())
self.graph.setCellVars(self.scope.get_cell_vars())
if self.scope.generator is not None:
self.graph.setFlag(CO_GENERATOR)
class GenExprCodeGenerator(NestedScopeMixin, AbstractFunctionCode,
CodeGenerator):
super_init = CodeGenerator.__init__ # call be other init
scopes = None
__super_init = AbstractFunctionCode.__init__
def __init__(self, gexp, scopes, class_name, mod):
self.scopes = scopes
self.scope = scopes[gexp]
self.__super_init(gexp, scopes, 1, class_name, mod)
self.graph.setFreeVars(self.scope.get_free_vars())
self.graph.setCellVars(self.scope.get_cell_vars())
self.graph.setFlag(CO_GENERATOR)
class AbstractClassCode:
def __init__(self, klass, scopes, module):
self.class_name = klass.name
self.module = module
self.graph = pyassem.PyFlowGraph(klass.name, klass.filename,
optimized=0, klass=1)
self.super_init()
lnf = walk(klass.code, self.NameFinder(), verbose=0)
self.locals.push(lnf.getLocals())
self.graph.setFlag(CO_NEWLOCALS)
if klass.doc:
self.setDocstring(klass.doc)
def get_module(self):
return self.module
def finish(self):
self.graph.startExitBlock()
self.emit('LOAD_LOCALS')
self.emit('RETURN_VALUE')
class ClassCodeGenerator(NestedScopeMixin, AbstractClassCode, CodeGenerator):
super_init = CodeGenerator.__init__
scopes = None
__super_init = AbstractClassCode.__init__
def __init__(self, klass, scopes, module):
self.scopes = scopes
self.scope = scopes[klass]
self.__super_init(klass, scopes, module)
self.graph.setFreeVars(self.scope.get_free_vars())
self.graph.setCellVars(self.scope.get_cell_vars())
self.set_lineno(klass)
self.emit("LOAD_GLOBAL", "__name__")
self.storeName("__module__")
if klass.doc:
self.emit("LOAD_CONST", klass.doc)
self.storeName('__doc__')
def generateArgList(arglist):
"""Generate an arg list marking TupleArgs"""
args = []
extra = []
count = 0
for i in range(len(arglist)):
elt = arglist[i]
if isinstance(elt, str):
args.append(elt)
elif isinstance(elt, tuple):
args.append(TupleArg(i * 2, elt))
extra.extend(misc.flatten(elt))
count = count + 1
else:
raise ValueError, "unexpect argument type:", elt
return args + extra, count
def findOp(node):
"""Find the op (DELETE, LOAD, STORE) in an AssTuple tree"""
v = OpFinder()
walk(node, v, verbose=0)
return v.op
class OpFinder:
def __init__(self):
self.op = None
def visitAssName(self, node):
if self.op is None:
self.op = node.flags
elif self.op != node.flags:
raise ValueError, "mixed ops in stmt"
visitAssAttr = visitAssName
visitSubscript = visitAssName
class Delegator:
"""Base class to support delegation for augmented assignment nodes
To generator code for augmented assignments, we use the following
wrapper classes. In visitAugAssign, the left-hand expression node
is visited twice. The first time the visit uses the normal method
for that node . The second time the visit uses a different method
that generates the appropriate code to perform the assignment.
These delegator classes wrap the original AST nodes in order to
support the variant visit methods.
"""
def __init__(self, obj):
self.obj = obj
def __getattr__(self, attr):
return getattr(self.obj, attr)
class AugGetattr(Delegator):
pass
class AugName(Delegator):
pass
class AugSlice(Delegator):
pass
class AugSubscript(Delegator):
pass
wrapper = {
ast.Getattr: AugGetattr,
ast.Name: AugName,
ast.Slice: AugSlice,
ast.Subscript: AugSubscript,
}
def wrap_aug(node):
return wrapper[node.__class__](node)
if __name__ == "__main__":
for file in sys.argv[1:]:
compileFile(file)