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Copy pathpycodegen.py
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1555 lines (1312 loc) · 46.7 KB
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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_IMPLICIT, SC_GLOBAL_EXPLICIT, \
SC_FREE, SC_CELL
from compiler.consts import (CO_VARARGS, CO_VARKEYWORDS, CO_NEWLOCALS,
CO_NESTED, CO_GENERATOR, CO_FUTURE_DIVISION,
CO_FUTURE_ABSIMPORT, CO_FUTURE_WITH_STATEMENT, CO_FUTURE_PRINT_FUNCTION)
from compiler.pyassem import TupleArg
# XXX The version-specific code can go, since this code only works with 2.x.
# Do we have Python 1.x or Python 2.x?
try:
VERSION = sys.version_info[0]
except AttributeError:
VERSION = 1
callfunc_opcode_info = {
# (Have *args, Have **args) : opcode
(0,0) : "CALL_FUNCTION",
(1,0) : "CALL_FUNCTION_VAR",
(0,1) : "CALL_FUNCTION_KW",
(1,1) : "CALL_FUNCTION_VAR_KW",
}
LOOP = 1
EXCEPT = 2
TRY_FINALLY = 3
END_FINALLY = 4
def compileFile(filename, display=0):
f = open(filename, 'U')
buf = f.read()
f.close()
mod = Module(buf, filename)
try:
mod.compile(display)
except SyntaxError:
raise
else:
f = open(filename + "c", "wb")
mod.dump(f)
f.close()
def compile(source, filename, mode, flags=None, dont_inherit=None):
"""Replacement for builtin compile() function"""
if flags is not None or dont_inherit is not None:
raise RuntimeError, "not implemented yet"
if mode == "single":
gen = Interactive(source, filename)
elif mode == "exec":
gen = Module(source, filename)
elif mode == "eval":
gen = Expression(source, filename)
else:
raise ValueError("compile() 3rd arg must be 'exec' or "
"'eval' or 'single'")
gen.compile()
return gen.code
class AbstractCompileMode:
mode = None # defined by subclass
def __init__(self, source, filename):
self.source = source
self.filename = filename
self.code = None
def _get_tree(self):
tree = parse(self.source, self.mode)
misc.set_filename(self.filename, tree)
syntax.check(tree)
return tree
def compile(self):
pass # implemented by subclass
def getCode(self):
return self.code
class Expression(AbstractCompileMode):
mode = "eval"
def compile(self):
tree = self._get_tree()
gen = ExpressionCodeGenerator(tree)
self.code = gen.getCode()
class Interactive(AbstractCompileMode):
mode = "single"
def compile(self):
tree = self._get_tree()
gen = InteractiveCodeGenerator(tree)
self.code = gen.getCode()
class Module(AbstractCompileMode):
mode = "exec"
def compile(self, display=0):
tree = self._get_tree()
gen = ModuleCodeGenerator(tree)
if display:
import pprint
print pprint.pprint(tree)
self.code = gen.getCode()
def dump(self, f):
f.write(self.getPycHeader())
marshal.dump(self.code, f)
MAGIC = imp.get_magic()
def getPycHeader(self):
# compile.c uses marshal to write a long directly, with
# calling the interface that would also generate a 1-byte code
# to indicate the type of the value. simplest way to get the
# same effect is to call marshal and then skip the code.
mtime = os.path.getmtime(self.filename)
mtime = struct.pack('<i', mtime)
return self.MAGIC + mtime
class LocalNameFinder:
"""Find local names in scope"""
def __init__(self, names=()):
self.names = misc.Set()
self.globals = misc.Set()
for name in names:
self.names.add(name)
# XXX list comprehensions and for loops
def getLocals(self):
for elt in self.globals.elements():
if self.names.has_elt(elt):
self.names.remove(elt)
return self.names
def visitDict(self, node):
pass
def visitGlobal(self, node):
for name in node.names:
self.globals.add(name)
def visitFunction(self, node):
self.names.add(node.name)
def visitLambda(self, node):
pass
def visitImport(self, node):
for name, alias in node.names:
self.names.add(alias or name)
def visitFrom(self, node):
for name, alias in node.names:
self.names.add(alias or name)
def visitClass(self, node):
self.names.add(node.name)
def visitAssName(self, node):
self.names.add(node.name)
def is_constant_false(node):
if isinstance(node, ast.Const):
if not node.value:
return 1
return 0
class CodeGenerator:
"""Defines basic code generator for Python bytecode
This class is an abstract base class. Concrete subclasses must
define an __init__() that defines self.graph and then calls the
__init__() defined in this class.
The concrete class must also define the class attributes
NameFinder, FunctionGen, and ClassGen. These attributes can be
defined in the initClass() method, which is a hook for
initializing these methods after all the classes have been
defined.
"""
optimized = 0 # is namespace access optimized?
__initialized = None
class_name = None # provide default for instance variable
def __init__(self):
if self.__initialized is None:
self.initClass()
self.__class__.__initialized = 1
self.checkClass()
self.locals = misc.Stack()
self.setups = misc.Stack()
self.last_lineno = None
self._setupGraphDelegation()
self._div_op = "BINARY_DIVIDE"
# XXX set flags based on future features
futures = self.get_module().futures
for feature in futures:
if feature == "division":
self.graph.setFlag(CO_FUTURE_DIVISION)
self._div_op = "BINARY_TRUE_DIVIDE"
elif feature == "absolute_import":
self.graph.setFlag(CO_FUTURE_ABSIMPORT)
elif feature == "with_statement":
self.graph.setFlag(CO_FUTURE_WITH_STATEMENT)
elif feature == "print_function":
self.graph.setFlag(CO_FUTURE_PRINT_FUNCTION)
def initClass(self):
"""This method is called once for each class"""
def checkClass(self):
"""Verify that class is constructed correctly"""
try:
assert hasattr(self, 'graph')
assert getattr(self, 'NameFinder')
assert getattr(self, 'FunctionGen')
assert getattr(self, 'ClassGen')
except AssertionError, msg:
intro = "Bad class construction for %s" % self.__class__.__name__
raise AssertionError, intro
def _setupGraphDelegation(self):
self.emit = self.graph.emit
self.newBlock = self.graph.newBlock
self.startBlock = self.graph.startBlock
self.nextBlock = self.graph.nextBlock
self.setDocstring = self.graph.setDocstring
def getCode(self):
"""Return a code object"""
return self.graph.getCode()
def mangle(self, name):
if self.class_name is not None:
return misc.mangle(name, self.class_name)
else:
return name
def parseSymbols(self, tree):
s = symbols.SymbolVisitor()
walk(tree, s)
return s.scopes
def get_module(self):
raise RuntimeError, "should be implemented by subclasses"
# Next five methods handle name access
def isLocalName(self, name):
return self.locals.top().has_elt(name)
def storeName(self, name):
self._nameOp('STORE', name)
def loadName(self, name):
self._nameOp('LOAD', name)
def delName(self, name):
self._nameOp('DELETE', name)
def _nameOp(self, prefix, name):
name = self.mangle(name)
scope = self.scope.check_name(name)
if scope == SC_LOCAL:
if not self.optimized:
self.emit(prefix + '_NAME', name)
else:
self.emit(prefix + '_FAST', name)
elif scope == SC_GLOBAL_EXPLICIT:
self.emit(prefix + '_GLOBAL', name)
elif scope == SC_GLOBAL_IMPLICIT:
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('POP_JUMP_IF_FALSE', nextTest)
self.nextBlock()
self.visit(suite)
self.emit('JUMP_FORWARD', end)
self.startBlock(nextTest)
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('POP_JUMP_IF_FALSE', else_ or after)
self.nextBlock()
self.visit(node.body)
self.emit('JUMP_ABSOLUTE', loop)
self.startBlock(else_) # or just the POPs if not else clause
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.visit(node.nodes[-1])
self.nextBlock(end)
def visitAnd(self, node):
self.visitTest(node, 'JUMP_IF_FALSE_OR_POP')
def visitOr(self, node):
self.visitTest(node, 'JUMP_IF_TRUE_OR_POP')
def visitIfExp(self, node):
endblock = self.newBlock()
elseblock = self.newBlock()
self.visit(node.test)
self.emit('POP_JUMP_IF_FALSE', elseblock)
self.visit(node.then)
self.emit('JUMP_FORWARD', endblock)
self.nextBlock(elseblock)
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_OR_POP', cleanup)
self.nextBlock()
# 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
def visitListComp(self, node):
self.set_lineno(node)
# setup list
self.emit('BUILD_LIST', 0)
stack = []
for i, for_ in zip(range(len(node.quals)), node.quals):
start, anchor = self.visit(for_)
cont = None
for if_ in for_.ifs:
if cont is None:
cont = self.newBlock()
self.visit(if_, cont)
stack.insert(0, (start, cont, anchor))
self.visit(node.expr)
self.emit('LIST_APPEND', len(node.quals) + 1)
for start, cont, anchor in stack:
if cont:
self.nextBlock(cont)
self.emit('JUMP_ABSOLUTE', start)
self.startBlock(anchor)
def visitSetComp(self, node):
self.set_lineno(node)
# setup list
self.emit('BUILD_SET', 0)
stack = []
for i, for_ in zip(range(len(node.quals)), node.quals):
start, anchor = self.visit(for_)
cont = None
for if_ in for_.ifs:
if cont is None:
cont = self.newBlock()
self.visit(if_, cont)
stack.insert(0, (start, cont, anchor))
self.visit(node.expr)
self.emit('SET_ADD', len(node.quals) + 1)
for start, cont, anchor in stack:
if cont:
self.nextBlock(cont)
self.emit('JUMP_ABSOLUTE', start)
self.startBlock(anchor)
def visitDictComp(self, node):
self.set_lineno(node)
# setup list
self.emit('BUILD_MAP', 0)
stack = []
for i, for_ in zip(range(len(node.quals)), node.quals):
start, anchor = self.visit(for_)
cont = None
for if_ in for_.ifs:
if cont is None:
cont = self.newBlock()
self.visit(if_, cont)
stack.insert(0, (start, cont, anchor))
self.visit(node.value)
self.visit(node.key)
self.emit('MAP_ADD', len(node.quals) + 1)
for start, cont, anchor in stack:
if cont:
self.nextBlock(cont)
self.emit('JUMP_ABSOLUTE', start)
self.startBlock(anchor)
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('POP_JUMP_IF_FALSE', branch)
self.newBlock()
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:
self.nextBlock(cont)
self.emit('JUMP_ABSOLUTE', start)
self.startBlock(anchor)
self.emit('POP_BLOCK')
self.setups.pop()
self.nextBlock(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('POP_JUMP_IF_FALSE', branch)
self.newBlock()
# 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('POP_JUMP_IF_TRUE', end)
self.nextBlock()
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)
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('POP_JUMP_IF_FALSE', next)
self.nextBlock()
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('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()
self.__with_count += 1
valuevar = "_[%d]" % self.__with_count
self.set_lineno(node)
self.visit(node.expr)
self.emit('DUP_TOP')
self.emit('LOAD_ATTR', '__exit__')
self.emit('ROT_TWO')
self.emit('LOAD_ATTR', '__enter__')
self.emit('CALL_FUNCTION', 0)
if node.vars is None:
self.emit('POP_TOP')
else:
self._implicitNameOp('STORE', valuevar)
self.emit('SETUP_FINALLY', final)
self.nextBlock(body)
self.setups.push((TRY_FINALLY, body))
if node.vars is not None:
self._implicitNameOp('LOAD', valuevar)
self._implicitNameOp('DELETE', valuevar)
self.visit(node.vars)
self.visit(node.body)
self.emit('POP_BLOCK')
self.setups.pop()
self.emit('LOAD_CONST', None)
self.nextBlock(final)
self.setups.push((END_FINALLY, final))
self.emit('WITH_CLEANUP')
self.emit('END_FINALLY')
self.setups.pop()
self.__with_count -= 1
# misc
def visitDiscard(self, node):
self.set_lineno(node)
self.visit(node.expr)
self.emit('POP_TOP')
def visitConst(self, node):
self.emit('LOAD_CONST', node.value)
def visitKeyword(self, node):
self.emit('LOAD_CONST', node.name)
self.visit(node.expr)
def visitGlobal(self, node):
# no code to generate
pass
def visitName(self, node):
self.set_lineno(node)
self.loadName(node.name)
def visitPass(self, node):
self.set_lineno(node)
def visitImport(self, node):
self.set_lineno(node)
level = 0 if self.graph.checkFlag(CO_FUTURE_ABSIMPORT) else -1
for name, alias in node.names:
if VERSION > 1:
self.emit('LOAD_CONST', level)
self.emit('LOAD_CONST', None)
self.emit('IMPORT_NAME', name)
mod = name.split(".")[0]
if alias:
self._resolveDots(name)
self.storeName(alias)
else:
self.storeName(mod)
def visitFrom(self, node):
self.set_lineno(node)
level = node.level
if level == 0 and not self.graph.checkFlag(CO_FUTURE_ABSIMPORT):
level = -1
fromlist = tuple(name for (name, alias) in node.names)
if VERSION > 1:
self.emit('LOAD_CONST', level)
self.emit('LOAD_CONST', fromlist)
self.emit('IMPORT_NAME', node.modname)
for name, alias in node.names:
if VERSION > 1:
if name == '*':
self.namespace = 0
self.emit('IMPORT_STAR')
# There can only be one name w/ from ... import *
assert len(node.names) == 1
return
else:
self.emit('IMPORT_FROM', name)
self._resolveDots(name)
self.storeName(alias or name)
else:
self.emit('IMPORT_FROM', name)
self.emit('POP_TOP')
def _resolveDots(self, name):
elts = name.split(".")
if len(elts) == 1:
return
for elt in elts[1:]:
self.emit('LOAD_ATTR', elt)
def visitGetattr(self, node):
self.visit(node.expr)
self.emit('LOAD_ATTR', self.mangle(node.attrname))
# next five implement assignments
def visitAssign(self, node):
self.set_lineno(node)
self.visit(node.expr)
dups = len(node.nodes) - 1
for i in range(len(node.nodes)):
elt = node.nodes[i]
if i < dups:
self.emit('DUP_TOP')
if isinstance(elt, ast.Node):
self.visit(elt)
def visitAssName(self, node):
if node.flags == 'OP_ASSIGN':
self.storeName(node.name)
elif node.flags == 'OP_DELETE':
self.set_lineno(node)
self.delName(node.name)
else:
print "oops", node.flags
def visitAssAttr(self, node):
self.visit(node.expr)
if node.flags == 'OP_ASSIGN':
self.emit('STORE_ATTR', self.mangle(node.attrname))
elif node.flags == 'OP_DELETE':
self.emit('DELETE_ATTR', self.mangle(node.attrname))
else:
print "warning: unexpected flags:", node.flags
print node
def _visitAssSequence(self, node, op='UNPACK_SEQUENCE'):
if findOp(node) != 'OP_DELETE':
self.emit(op, len(node.nodes))
for child in node.nodes:
self.visit(child)
if VERSION > 1:
visitAssTuple = _visitAssSequence
visitAssList = _visitAssSequence
else:
def visitAssTuple(self, node):
self._visitAssSequence(node, 'UNPACK_TUPLE')
def visitAssList(self, node):
self._visitAssSequence(node, 'UNPACK_LIST')
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