Preliminary support for nested scopes

XXX Still doesn't work right for classes
XXX Still doesn't do sufficient error checking
This commit is contained in:
Jeremy Hylton 2001-04-12 06:40:42 +00:00
parent 53ee2a94c7
commit 364f9b9e2f
6 changed files with 792 additions and 178 deletions

View File

@ -99,12 +99,6 @@ class FlowGraph:
if not self.exit in order:
order.append(self.exit)
## for b in order:
## print repr(b)
## print "\t", b.get_children()
## print b
## print
return order
def getBlocks(self):
@ -222,6 +216,7 @@ CO_OPTIMIZED = 0x0001
CO_NEWLOCALS = 0x0002
CO_VARARGS = 0x0004
CO_VARKEYWORDS = 0x0008
CO_NESTED = 0x0010
# the FlowGraph is transformed in place; it exists in one of these states
RAW = "RAW"
@ -245,6 +240,15 @@ class PyFlowGraph(FlowGraph):
self.flags = 0
self.consts = []
self.names = []
# Free variables found by the symbol table scan, including
# variables used only in nested scopes, are included here.
self.freevars = []
self.cellvars = []
# The closure list is used to track the order of cell
# variables and free variables in the resulting code object.
# The offsets used by LOAD_CLOSURE/LOAD_DEREF refer to both
# kinds of variables.
self.closure = []
self.varnames = list(args) or []
for i in range(len(self.varnames)):
var = self.varnames[i]
@ -260,6 +264,12 @@ class PyFlowGraph(FlowGraph):
if flag == CO_VARARGS:
self.argcount = self.argcount - 1
def setFreeVars(self, names):
self.freevars = list(names)
def setCellVars(self, names):
self.cellvars = names
def getCode(self):
"""Get a Python code object"""
if self.stage == RAW:
@ -335,6 +345,7 @@ class PyFlowGraph(FlowGraph):
"""Convert arguments from symbolic to concrete form"""
assert self.stage == FLAT
self.consts.insert(0, self.docstring)
self.sort_cellvars()
for i in range(len(self.insts)):
t = self.insts[i]
if len(t) == 2:
@ -345,6 +356,19 @@ class PyFlowGraph(FlowGraph):
self.insts[i] = opname, conv(self, oparg)
self.stage = CONV
def sort_cellvars(self):
"""Sort cellvars in the order of varnames and prune from freevars.
"""
cells = {}
for name in self.cellvars:
cells[name] = 1
self.cellvars = [name for name in self.varnames
if cells.has_key(name)]
for name in self.cellvars:
del cells[name]
self.cellvars = self.cellvars + cells.keys()
self.closure = self.cellvars + self.freevars
def _lookupName(self, name, list):
"""Return index of name in list, appending if necessary"""
t = type(name)
@ -382,6 +406,17 @@ class PyFlowGraph(FlowGraph):
_convert_STORE_GLOBAL = _convert_NAME
_convert_DELETE_GLOBAL = _convert_NAME
def _convert_DEREF(self, arg):
self._lookupName(arg, self.names)
self._lookupName(arg, self.varnames)
return self._lookupName(arg, self.closure)
_convert_LOAD_DEREF = _convert_DEREF
_convert_STORE_DEREF = _convert_DEREF
def _convert_LOAD_CLOSURE(self, arg):
self._lookupName(arg, self.varnames)
return self._lookupName(arg, self.closure)
_cmp = list(dis.cmp_op)
def _convert_COMPARE_OP(self, arg):
return self._cmp.index(arg)
@ -432,7 +467,8 @@ class PyFlowGraph(FlowGraph):
self.lnotab.getCode(), self.getConsts(),
tuple(self.names), tuple(self.varnames),
self.filename, self.name, self.lnotab.firstline,
self.lnotab.getTable())
self.lnotab.getTable(), tuple(self.freevars),
tuple(self.cellvars))
def getConsts(self):
"""Return a tuple for the const slot of the code object

View File

@ -9,8 +9,10 @@ import types
from cStringIO import StringIO
from compiler import ast, parse, walk
from compiler import pyassem, misc, future
from compiler.pyassem import CO_VARARGS, CO_VARKEYWORDS, CO_NEWLOCALS, TupleArg
from compiler import pyassem, misc, future, symbols
from compiler.consts import SC_LOCAL, SC_GLOBAL, SC_FREE, SC_CELL
from compiler.pyassem import CO_VARARGS, CO_VARKEYWORDS, CO_NEWLOCALS,\
CO_NESTED, TupleArg
# Do we have Python 1.x or Python 2.x?
try:
@ -46,7 +48,7 @@ class Module:
tree = parse(self.source)
root, filename = os.path.split(self.filename)
if "nested_scopes" in future.find_futures(tree):
gen = NestedScopeCodeGenerator(filename)
gen = NestedScopeModuleCodeGenerator(filename)
else:
gen = ModuleCodeGenerator(filename)
walk(tree, gen, 1)
@ -70,14 +72,71 @@ class Module:
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)
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
def __init__(self, filename):
## Subclasses must define a constructor that intializes self.graph
## before calling this init function, e.g.
## self.graph = pyassem.PyFlowGraph()
if self.__initialized is None:
self.initClass()
self.__class__.__initialized = 1
self.checkClass()
self.filename = filename
self.locals = misc.Stack()
self.loops = misc.Stack()
@ -86,6 +145,20 @@ class CodeGenerator:
self.last_lineno = None
self._setupGraphDelegation()
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
@ -139,10 +212,15 @@ class CodeGenerator:
return 0
# The first few visitor methods handle nodes that generator new
# code objects
# code objects. They use class attributes to determine what
# specialized code generators to use.
NameFinder = LocalNameFinder
FunctionGen = None
ClassGen = None
def visitModule(self, node):
lnf = walk(node.node, LocalNameFinder(), 0)
lnf = walk(node.node, self.NameFinder(), 0)
self.locals.push(lnf.getLocals())
if node.doc:
self.fixDocstring(node.node)
@ -159,8 +237,8 @@ class CodeGenerator:
def visitLambda(self, node):
self._visitFuncOrLambda(node, isLambda=1)
def _visitFuncOrLambda(self, node, isLambda):
gen = FunctionCodeGenerator(node, self.filename, isLambda)
def _visitFuncOrLambda(self, node, isLambda=0):
gen = self.FunctionGen(node, self.filename, self.scopes, isLambda)
walk(node.code, gen)
gen.finish()
self.set_lineno(node)
@ -170,7 +248,7 @@ class CodeGenerator:
self.emit('MAKE_FUNCTION', len(node.defaults))
def visitClass(self, node):
gen = ClassCodeGenerator(node, self.filename)
gen = self.ClassGen(node, self.filename, self.scopes)
if node.doc:
self.fixDocstring(node.code)
walk(node.code, gen)
@ -180,7 +258,7 @@ class CodeGenerator:
for base in node.bases:
self.visit(base)
self.emit('BUILD_TUPLE', len(node.bases))
self.emit('LOAD_CONST', gen.getCode())
self.emit('LOAD_CONST', gen)
self.emit('MAKE_FUNCTION', 0)
self.emit('CALL_FUNCTION', 0)
self.emit('BUILD_CLASS')
@ -883,34 +961,114 @@ class CodeGenerator:
self.visit(k)
self.emit('STORE_SUBSCR')
class ModuleCodeGenerator(CodeGenerator):
__super_init = CodeGenerator.__init__
class NestedScopeCodeGenerator(CodeGenerator):
__super_visitModule = CodeGenerator.visitModule
def __init__(self, filename):
# XXX <module> is ? in compile.c
self.graph = pyassem.PyFlowGraph("<module>", filename)
self.__super_init(filename)
self.symbols = None
__super_visitClass = CodeGenerator.visitClass
__super__visitFuncOrLambda = CodeGenerator._visitFuncOrLambda
def parseSymbols(self, tree):
s = symbols.SymbolVisitor()
walk(tree, s)
return s.scopes
def visitModule(self, node):
self.symbols = self.parseSymbols(node)
self.scopes = self.parseSymbols(node)
self.scope = self.scopes[node]
self.__super_visitModule(node)
def parseSymbols(self, node):
# XXX not implemented
return None
def _nameOp(self, prefix, 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:
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)
class NestedScopeCodeGenerator(ModuleCodeGenerator):
pass
def _visitFuncOrLambda(self, node, isLambda=0):
gen = self.FunctionGen(node, self.filename, self.scopes, isLambda)
walk(node.code, gen)
gen.finish()
self.set_lineno(node)
for default in node.defaults:
self.visit(default)
frees = gen.scope.get_free_vars()
if frees:
for name in frees:
self.emit('LOAD_CLOSURE', name)
self.emit('LOAD_CONST', gen)
self.emit('MAKE_CLOSURE', len(node.defaults))
else:
self.emit('LOAD_CONST', gen)
self.emit('MAKE_FUNCTION', len(node.defaults))
class FunctionCodeGenerator(CodeGenerator):
super_init = CodeGenerator.__init__
def visitClass(self, node):
gen = self.ClassGen(node, self.filename, self.scopes)
if node.doc:
self.fixDocstring(node.code)
walk(node.code, gen)
gen.finish()
self.set_lineno(node)
self.emit('LOAD_CONST', node.name)
for base in node.bases:
self.visit(base)
self.emit('BUILD_TUPLE', len(node.bases))
frees = gen.scope.get_free_vars()
for name in frees:
self.emit('LOAD_CLOSURE', name)
self.emit('LOAD_CONST', gen)
if frees:
self.emit('MAKE_CLOSURE', 0)
else:
self.emit('MAKE_FUNCTION', 0)
self.emit('CALL_FUNCTION', 0)
self.emit('BUILD_CLASS')
self.storeName(node.name)
class LGBScopeMixin:
"""Defines initClass() for Python 2.1-compatible scoping"""
def initClass(self):
self.__class__.NameFinder = LocalNameFinder
self.__class__.FunctionGen = FunctionCodeGenerator
self.__class__.ClassGen = ClassCodeGenerator
class NestedScopeMixin:
"""Defines initClass() for nested scoping (Python 2.2-compatible)"""
def initClass(self):
self.__class__.NameFinder = LocalNameFinder
self.__class__.FunctionGen = NestedFunctionCodeGenerator
self.__class__.ClassGen = NestedClassCodeGenerator
class ModuleCodeGenerator(LGBScopeMixin, CodeGenerator):
__super_init = CodeGenerator.__init__
scopes = None
def __init__(self, filename):
self.graph = pyassem.PyFlowGraph("<module>", filename)
self.__super_init(filename)
class NestedScopeModuleCodeGenerator(NestedScopeMixin,
NestedScopeCodeGenerator):
__super_init = CodeGenerator.__init__
def __init__(self, filename):
self.graph = pyassem.PyFlowGraph("<module>", filename)
self.__super_init(filename)
self.graph.setFlag(CO_NESTED)
class AbstractFunctionCode:
optimized = 1
lambdaCount = 0
def __init__(self, func, filename, isLambda=0):
def __init__(self, func, filename, scopes, isLambda):
if isLambda:
klass = FunctionCodeGenerator
name = "<lambda.%d>" % klass.lambdaCount
@ -926,7 +1084,7 @@ class FunctionCodeGenerator(CodeGenerator):
if not isLambda and func.doc:
self.setDocstring(func.doc)
lnf = walk(func.code, LocalNameFinder(args), 0)
lnf = walk(func.code, self.NameFinder(args), 0)
self.locals.push(lnf.getLocals())
if func.varargs:
self.graph.setFlag(CO_VARARGS)
@ -963,14 +1121,32 @@ class FunctionCodeGenerator(CodeGenerator):
unpackTuple = unpackSequence
class ClassCodeGenerator(CodeGenerator):
super_init = CodeGenerator.__init__
class FunctionCodeGenerator(LGBScopeMixin, AbstractFunctionCode,
CodeGenerator):
super_init = CodeGenerator.__init__ # call be other init
scopes = None
def __init__(self, klass, filename):
class NestedFunctionCodeGenerator(AbstractFunctionCode,
NestedScopeMixin,
NestedScopeCodeGenerator):
super_init = NestedScopeCodeGenerator.__init__ # call be other init
__super_init = AbstractFunctionCode.__init__
def __init__(self, func, filename, scopes, isLambda):
self.scopes = scopes
self.scope = scopes[func]
self.__super_init(func, filename, scopes, isLambda)
self.graph.setFreeVars(self.scope.get_free_vars())
self.graph.setCellVars(self.scope.get_cell_vars())
self.graph.setFlag(CO_NESTED)
class AbstractClassCode:
def __init__(self, klass, filename, scopes):
self.graph = pyassem.PyFlowGraph(klass.name, filename,
optimized=0)
self.super_init(filename)
lnf = walk(klass.code, LocalNameFinder(), 0)
lnf = walk(klass.code, self.NameFinder(), 0)
self.locals.push(lnf.getLocals())
self.graph.setFlag(CO_NEWLOCALS)
if klass.doc:
@ -981,6 +1157,24 @@ class ClassCodeGenerator(CodeGenerator):
self.emit('LOAD_LOCALS')
self.emit('RETURN_VALUE')
class ClassCodeGenerator(LGBScopeMixin, AbstractClassCode, CodeGenerator):
super_init = CodeGenerator.__init__
scopes = None
class NestedClassCodeGenerator(AbstractClassCode,
NestedScopeMixin,
NestedScopeCodeGenerator):
super_init = NestedScopeCodeGenerator.__init__ # call be other init
__super_init = AbstractClassCode.__init__
def __init__(self, klass, filename, scopes):
self.scopes = scopes
self.scope = scopes[klass]
self.__super_init(klass, filename, scopes)
self.graph.setFreeVars(self.scope.get_free_vars())
self.graph.setCellVars(self.scope.get_cell_vars())
self.graph.setFlag(CO_NESTED)
def generateArgList(arglist):
"""Generate an arg list marking TupleArgs"""
args = []
@ -997,49 +1191,6 @@ def generateArgList(arglist):
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)
# 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 findOp(node):
"""Find the op (DELETE, LOAD, STORE) in an AssTuple tree"""
v = OpFinder()

View File

@ -1,8 +1,11 @@
"""Module symbol-table generator"""
from compiler import ast
from compiler.consts import SC_LOCAL, SC_GLOBAL, SC_FREE, SC_CELL, SC_UNKNOWN
import types
import sys
MANGLE_LEN = 256
class Scope:
@ -14,7 +17,12 @@ class Scope:
self.uses = {}
self.globals = {}
self.params = {}
self.frees = {}
self.cells = {}
self.children = []
# nested is true if the class could contain free variables,
# i.e. if it is nested within another function.
self.nested = None
self.klass = None
if klass is not None:
for i in range(len(klass)):
@ -70,13 +78,112 @@ class Scope:
def get_children(self):
return self.children
def DEBUG(self):
return
print >> sys.stderr, self.name, self.nested and "nested" or ""
print >> sys.stderr, "\tglobals: ", self.globals
print >> sys.stderr, "\tcells: ", self.cells
print >> sys.stderr, "\tdefs: ", self.defs
print >> sys.stderr, "\tuses: ", self.uses
print >> sys.stderr, "\tfrees:", self.frees
def check_name(self, name):
"""Return scope of name.
The scope of a name could be LOCAL, GLOBAL, FREE, or CELL.
"""
if self.globals.has_key(name):
return SC_GLOBAL
if self.cells.has_key(name):
return SC_CELL
if self.defs.has_key(name):
return SC_LOCAL
if self.nested and (self.frees.has_key(name) or
self.uses.has_key(name)):
return SC_FREE
if self.nested:
return SC_UNKNOWN
else:
return SC_GLOBAL
def get_free_vars(self):
if not self.nested:
return ()
free = {}
free.update(self.frees)
for name in self.uses.keys():
if not (self.defs.has_key(name) or
self.globals.has_key(name)):
free[name] = 1
return free.keys()
def handle_children(self):
for child in self.children:
frees = child.get_free_vars()
globals = self.add_frees(frees)
for name in globals:
child.force_global(name)
def force_global(self, name):
"""Force name to be global in scope.
Some child of the current node had a free reference to name.
When the child was processed, it was labelled a free
variable. Now that all its enclosing scope have been
processed, the name is known to be a global or builtin. So
walk back down the child chain and set the name to be global
rather than free.
Be careful to stop if a child does not think the name is
free.
"""
self.globals[name] = 1
if self.frees.has_key(name):
del self.frees[name]
for child in self.children:
if child.check_name(name) == SC_FREE:
child.force_global(name)
def add_frees(self, names):
"""Process list of free vars from nested scope.
Returns a list of names that are either 1) declared global in the
parent or 2) undefined in a top-level parent. In either case,
the nested scope should treat them as globals.
"""
child_globals = []
for name in names:
sc = self.check_name(name)
if self.nested:
if sc == SC_UNKNOWN or sc == SC_FREE \
or isinstance(self, ClassScope):
self.frees[name] = 1
elif sc == SC_GLOBAL:
child_globals.append(name)
elif isinstance(self, FunctionScope) and sc == SC_LOCAL:
self.cells[name] = 1
else:
child_globals.append(name)
else:
if sc == SC_LOCAL:
self.cells[name] = 1
else:
child_globals.append(name)
return child_globals
def get_cell_vars(self):
return self.cells.keys()
class ModuleScope(Scope):
__super_init = Scope.__init__
def __init__(self):
self.__super_init("global", self)
class LambdaScope(Scope):
class FunctionScope(Scope):
pass
class LambdaScope(FunctionScope):
__super_init = Scope.__init__
__counter = 1
@ -86,9 +193,6 @@ class LambdaScope(Scope):
self.__counter += 1
self.__super_init("lambda.%d" % i, module, klass)
class FunctionScope(Scope):
pass
class ClassScope(Scope):
__super_init = Scope.__init__
@ -111,17 +215,24 @@ class SymbolVisitor:
for n in node.defaults:
self.visit(n, parent)
scope = FunctionScope(node.name, self.module, self.klass)
if parent.nested or isinstance(parent, FunctionScope):
scope.nested = 1
self.scopes[node] = scope
self._do_args(scope, node.argnames)
self.visit(node.code, scope)
self.handle_free_vars(scope, parent)
scope.DEBUG()
def visitLambda(self, node, parent):
for n in node.defaults:
self.visit(n, parent)
scope = LambdaScope(self.module, self.klass)
if parent.nested or isinstance(parent, FunctionScope):
scope.nested = 1
self.scopes[node] = scope
self._do_args(scope, node.argnames)
self.visit(node.code, scope)
self.handle_free_vars(scope, parent)
def _do_args(self, scope, args):
for name in args:
@ -130,16 +241,25 @@ class SymbolVisitor:
else:
scope.add_param(name)
def handle_free_vars(self, scope, parent):
parent.add_child(scope)
if scope.children:
scope.DEBUG()
scope.handle_children()
def visitClass(self, node, parent):
parent.add_def(node.name)
for n in node.bases:
self.visit(n, parent)
scope = ClassScope(node.name, self.module)
if parent.nested or isinstance(parent, FunctionScope):
scope.nested = 1
self.scopes[node] = scope
prev = self.klass
self.klass = node.name
self.visit(node.code, scope)
self.klass = prev
self.handle_free_vars(scope, parent)
# name can be a def or a use

View File

@ -99,12 +99,6 @@ class FlowGraph:
if not self.exit in order:
order.append(self.exit)
## for b in order:
## print repr(b)
## print "\t", b.get_children()
## print b
## print
return order
def getBlocks(self):
@ -222,6 +216,7 @@ CO_OPTIMIZED = 0x0001
CO_NEWLOCALS = 0x0002
CO_VARARGS = 0x0004
CO_VARKEYWORDS = 0x0008
CO_NESTED = 0x0010
# the FlowGraph is transformed in place; it exists in one of these states
RAW = "RAW"
@ -245,6 +240,15 @@ class PyFlowGraph(FlowGraph):
self.flags = 0
self.consts = []
self.names = []
# Free variables found by the symbol table scan, including
# variables used only in nested scopes, are included here.
self.freevars = []
self.cellvars = []
# The closure list is used to track the order of cell
# variables and free variables in the resulting code object.
# The offsets used by LOAD_CLOSURE/LOAD_DEREF refer to both
# kinds of variables.
self.closure = []
self.varnames = list(args) or []
for i in range(len(self.varnames)):
var = self.varnames[i]
@ -260,6 +264,12 @@ class PyFlowGraph(FlowGraph):
if flag == CO_VARARGS:
self.argcount = self.argcount - 1
def setFreeVars(self, names):
self.freevars = list(names)
def setCellVars(self, names):
self.cellvars = names
def getCode(self):
"""Get a Python code object"""
if self.stage == RAW:
@ -335,6 +345,7 @@ class PyFlowGraph(FlowGraph):
"""Convert arguments from symbolic to concrete form"""
assert self.stage == FLAT
self.consts.insert(0, self.docstring)
self.sort_cellvars()
for i in range(len(self.insts)):
t = self.insts[i]
if len(t) == 2:
@ -345,6 +356,19 @@ class PyFlowGraph(FlowGraph):
self.insts[i] = opname, conv(self, oparg)
self.stage = CONV
def sort_cellvars(self):
"""Sort cellvars in the order of varnames and prune from freevars.
"""
cells = {}
for name in self.cellvars:
cells[name] = 1
self.cellvars = [name for name in self.varnames
if cells.has_key(name)]
for name in self.cellvars:
del cells[name]
self.cellvars = self.cellvars + cells.keys()
self.closure = self.cellvars + self.freevars
def _lookupName(self, name, list):
"""Return index of name in list, appending if necessary"""
t = type(name)
@ -382,6 +406,17 @@ class PyFlowGraph(FlowGraph):
_convert_STORE_GLOBAL = _convert_NAME
_convert_DELETE_GLOBAL = _convert_NAME
def _convert_DEREF(self, arg):
self._lookupName(arg, self.names)
self._lookupName(arg, self.varnames)
return self._lookupName(arg, self.closure)
_convert_LOAD_DEREF = _convert_DEREF
_convert_STORE_DEREF = _convert_DEREF
def _convert_LOAD_CLOSURE(self, arg):
self._lookupName(arg, self.varnames)
return self._lookupName(arg, self.closure)
_cmp = list(dis.cmp_op)
def _convert_COMPARE_OP(self, arg):
return self._cmp.index(arg)
@ -432,7 +467,8 @@ class PyFlowGraph(FlowGraph):
self.lnotab.getCode(), self.getConsts(),
tuple(self.names), tuple(self.varnames),
self.filename, self.name, self.lnotab.firstline,
self.lnotab.getTable())
self.lnotab.getTable(), tuple(self.freevars),
tuple(self.cellvars))
def getConsts(self):
"""Return a tuple for the const slot of the code object

View File

@ -9,8 +9,10 @@ import types
from cStringIO import StringIO
from compiler import ast, parse, walk
from compiler import pyassem, misc, future
from compiler.pyassem import CO_VARARGS, CO_VARKEYWORDS, CO_NEWLOCALS, TupleArg
from compiler import pyassem, misc, future, symbols
from compiler.consts import SC_LOCAL, SC_GLOBAL, SC_FREE, SC_CELL
from compiler.pyassem import CO_VARARGS, CO_VARKEYWORDS, CO_NEWLOCALS,\
CO_NESTED, TupleArg
# Do we have Python 1.x or Python 2.x?
try:
@ -46,7 +48,7 @@ class Module:
tree = parse(self.source)
root, filename = os.path.split(self.filename)
if "nested_scopes" in future.find_futures(tree):
gen = NestedScopeCodeGenerator(filename)
gen = NestedScopeModuleCodeGenerator(filename)
else:
gen = ModuleCodeGenerator(filename)
walk(tree, gen, 1)
@ -70,14 +72,71 @@ class Module:
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)
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
def __init__(self, filename):
## Subclasses must define a constructor that intializes self.graph
## before calling this init function, e.g.
## self.graph = pyassem.PyFlowGraph()
if self.__initialized is None:
self.initClass()
self.__class__.__initialized = 1
self.checkClass()
self.filename = filename
self.locals = misc.Stack()
self.loops = misc.Stack()
@ -86,6 +145,20 @@ class CodeGenerator:
self.last_lineno = None
self._setupGraphDelegation()
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
@ -139,10 +212,15 @@ class CodeGenerator:
return 0
# The first few visitor methods handle nodes that generator new
# code objects
# code objects. They use class attributes to determine what
# specialized code generators to use.
NameFinder = LocalNameFinder
FunctionGen = None
ClassGen = None
def visitModule(self, node):
lnf = walk(node.node, LocalNameFinder(), 0)
lnf = walk(node.node, self.NameFinder(), 0)
self.locals.push(lnf.getLocals())
if node.doc:
self.fixDocstring(node.node)
@ -159,8 +237,8 @@ class CodeGenerator:
def visitLambda(self, node):
self._visitFuncOrLambda(node, isLambda=1)
def _visitFuncOrLambda(self, node, isLambda):
gen = FunctionCodeGenerator(node, self.filename, isLambda)
def _visitFuncOrLambda(self, node, isLambda=0):
gen = self.FunctionGen(node, self.filename, self.scopes, isLambda)
walk(node.code, gen)
gen.finish()
self.set_lineno(node)
@ -170,7 +248,7 @@ class CodeGenerator:
self.emit('MAKE_FUNCTION', len(node.defaults))
def visitClass(self, node):
gen = ClassCodeGenerator(node, self.filename)
gen = self.ClassGen(node, self.filename, self.scopes)
if node.doc:
self.fixDocstring(node.code)
walk(node.code, gen)
@ -180,7 +258,7 @@ class CodeGenerator:
for base in node.bases:
self.visit(base)
self.emit('BUILD_TUPLE', len(node.bases))
self.emit('LOAD_CONST', gen.getCode())
self.emit('LOAD_CONST', gen)
self.emit('MAKE_FUNCTION', 0)
self.emit('CALL_FUNCTION', 0)
self.emit('BUILD_CLASS')
@ -883,34 +961,114 @@ class CodeGenerator:
self.visit(k)
self.emit('STORE_SUBSCR')
class ModuleCodeGenerator(CodeGenerator):
__super_init = CodeGenerator.__init__
class NestedScopeCodeGenerator(CodeGenerator):
__super_visitModule = CodeGenerator.visitModule
def __init__(self, filename):
# XXX <module> is ? in compile.c
self.graph = pyassem.PyFlowGraph("<module>", filename)
self.__super_init(filename)
self.symbols = None
__super_visitClass = CodeGenerator.visitClass
__super__visitFuncOrLambda = CodeGenerator._visitFuncOrLambda
def parseSymbols(self, tree):
s = symbols.SymbolVisitor()
walk(tree, s)
return s.scopes
def visitModule(self, node):
self.symbols = self.parseSymbols(node)
self.scopes = self.parseSymbols(node)
self.scope = self.scopes[node]
self.__super_visitModule(node)
def parseSymbols(self, node):
# XXX not implemented
return None
def _nameOp(self, prefix, 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:
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)
class NestedScopeCodeGenerator(ModuleCodeGenerator):
pass
def _visitFuncOrLambda(self, node, isLambda=0):
gen = self.FunctionGen(node, self.filename, self.scopes, isLambda)
walk(node.code, gen)
gen.finish()
self.set_lineno(node)
for default in node.defaults:
self.visit(default)
frees = gen.scope.get_free_vars()
if frees:
for name in frees:
self.emit('LOAD_CLOSURE', name)
self.emit('LOAD_CONST', gen)
self.emit('MAKE_CLOSURE', len(node.defaults))
else:
self.emit('LOAD_CONST', gen)
self.emit('MAKE_FUNCTION', len(node.defaults))
class FunctionCodeGenerator(CodeGenerator):
super_init = CodeGenerator.__init__
def visitClass(self, node):
gen = self.ClassGen(node, self.filename, self.scopes)
if node.doc:
self.fixDocstring(node.code)
walk(node.code, gen)
gen.finish()
self.set_lineno(node)
self.emit('LOAD_CONST', node.name)
for base in node.bases:
self.visit(base)
self.emit('BUILD_TUPLE', len(node.bases))
frees = gen.scope.get_free_vars()
for name in frees:
self.emit('LOAD_CLOSURE', name)
self.emit('LOAD_CONST', gen)
if frees:
self.emit('MAKE_CLOSURE', 0)
else:
self.emit('MAKE_FUNCTION', 0)
self.emit('CALL_FUNCTION', 0)
self.emit('BUILD_CLASS')
self.storeName(node.name)
class LGBScopeMixin:
"""Defines initClass() for Python 2.1-compatible scoping"""
def initClass(self):
self.__class__.NameFinder = LocalNameFinder
self.__class__.FunctionGen = FunctionCodeGenerator
self.__class__.ClassGen = ClassCodeGenerator
class NestedScopeMixin:
"""Defines initClass() for nested scoping (Python 2.2-compatible)"""
def initClass(self):
self.__class__.NameFinder = LocalNameFinder
self.__class__.FunctionGen = NestedFunctionCodeGenerator
self.__class__.ClassGen = NestedClassCodeGenerator
class ModuleCodeGenerator(LGBScopeMixin, CodeGenerator):
__super_init = CodeGenerator.__init__
scopes = None
def __init__(self, filename):
self.graph = pyassem.PyFlowGraph("<module>", filename)
self.__super_init(filename)
class NestedScopeModuleCodeGenerator(NestedScopeMixin,
NestedScopeCodeGenerator):
__super_init = CodeGenerator.__init__
def __init__(self, filename):
self.graph = pyassem.PyFlowGraph("<module>", filename)
self.__super_init(filename)
self.graph.setFlag(CO_NESTED)
class AbstractFunctionCode:
optimized = 1
lambdaCount = 0
def __init__(self, func, filename, isLambda=0):
def __init__(self, func, filename, scopes, isLambda):
if isLambda:
klass = FunctionCodeGenerator
name = "<lambda.%d>" % klass.lambdaCount
@ -926,7 +1084,7 @@ class FunctionCodeGenerator(CodeGenerator):
if not isLambda and func.doc:
self.setDocstring(func.doc)
lnf = walk(func.code, LocalNameFinder(args), 0)
lnf = walk(func.code, self.NameFinder(args), 0)
self.locals.push(lnf.getLocals())
if func.varargs:
self.graph.setFlag(CO_VARARGS)
@ -963,14 +1121,32 @@ class FunctionCodeGenerator(CodeGenerator):
unpackTuple = unpackSequence
class ClassCodeGenerator(CodeGenerator):
super_init = CodeGenerator.__init__
class FunctionCodeGenerator(LGBScopeMixin, AbstractFunctionCode,
CodeGenerator):
super_init = CodeGenerator.__init__ # call be other init
scopes = None
def __init__(self, klass, filename):
class NestedFunctionCodeGenerator(AbstractFunctionCode,
NestedScopeMixin,
NestedScopeCodeGenerator):
super_init = NestedScopeCodeGenerator.__init__ # call be other init
__super_init = AbstractFunctionCode.__init__
def __init__(self, func, filename, scopes, isLambda):
self.scopes = scopes
self.scope = scopes[func]
self.__super_init(func, filename, scopes, isLambda)
self.graph.setFreeVars(self.scope.get_free_vars())
self.graph.setCellVars(self.scope.get_cell_vars())
self.graph.setFlag(CO_NESTED)
class AbstractClassCode:
def __init__(self, klass, filename, scopes):
self.graph = pyassem.PyFlowGraph(klass.name, filename,
optimized=0)
self.super_init(filename)
lnf = walk(klass.code, LocalNameFinder(), 0)
lnf = walk(klass.code, self.NameFinder(), 0)
self.locals.push(lnf.getLocals())
self.graph.setFlag(CO_NEWLOCALS)
if klass.doc:
@ -981,6 +1157,24 @@ class ClassCodeGenerator(CodeGenerator):
self.emit('LOAD_LOCALS')
self.emit('RETURN_VALUE')
class ClassCodeGenerator(LGBScopeMixin, AbstractClassCode, CodeGenerator):
super_init = CodeGenerator.__init__
scopes = None
class NestedClassCodeGenerator(AbstractClassCode,
NestedScopeMixin,
NestedScopeCodeGenerator):
super_init = NestedScopeCodeGenerator.__init__ # call be other init
__super_init = AbstractClassCode.__init__
def __init__(self, klass, filename, scopes):
self.scopes = scopes
self.scope = scopes[klass]
self.__super_init(klass, filename, scopes)
self.graph.setFreeVars(self.scope.get_free_vars())
self.graph.setCellVars(self.scope.get_cell_vars())
self.graph.setFlag(CO_NESTED)
def generateArgList(arglist):
"""Generate an arg list marking TupleArgs"""
args = []
@ -997,49 +1191,6 @@ def generateArgList(arglist):
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)
# 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 findOp(node):
"""Find the op (DELETE, LOAD, STORE) in an AssTuple tree"""
v = OpFinder()

View File

@ -1,8 +1,11 @@
"""Module symbol-table generator"""
from compiler import ast
from compiler.consts import SC_LOCAL, SC_GLOBAL, SC_FREE, SC_CELL, SC_UNKNOWN
import types
import sys
MANGLE_LEN = 256
class Scope:
@ -14,7 +17,12 @@ class Scope:
self.uses = {}
self.globals = {}
self.params = {}
self.frees = {}
self.cells = {}
self.children = []
# nested is true if the class could contain free variables,
# i.e. if it is nested within another function.
self.nested = None
self.klass = None
if klass is not None:
for i in range(len(klass)):
@ -70,13 +78,112 @@ class Scope:
def get_children(self):
return self.children
def DEBUG(self):
return
print >> sys.stderr, self.name, self.nested and "nested" or ""
print >> sys.stderr, "\tglobals: ", self.globals
print >> sys.stderr, "\tcells: ", self.cells
print >> sys.stderr, "\tdefs: ", self.defs
print >> sys.stderr, "\tuses: ", self.uses
print >> sys.stderr, "\tfrees:", self.frees
def check_name(self, name):
"""Return scope of name.
The scope of a name could be LOCAL, GLOBAL, FREE, or CELL.
"""
if self.globals.has_key(name):
return SC_GLOBAL
if self.cells.has_key(name):
return SC_CELL
if self.defs.has_key(name):
return SC_LOCAL
if self.nested and (self.frees.has_key(name) or
self.uses.has_key(name)):
return SC_FREE
if self.nested:
return SC_UNKNOWN
else:
return SC_GLOBAL
def get_free_vars(self):
if not self.nested:
return ()
free = {}
free.update(self.frees)
for name in self.uses.keys():
if not (self.defs.has_key(name) or
self.globals.has_key(name)):
free[name] = 1
return free.keys()
def handle_children(self):
for child in self.children:
frees = child.get_free_vars()
globals = self.add_frees(frees)
for name in globals:
child.force_global(name)
def force_global(self, name):
"""Force name to be global in scope.
Some child of the current node had a free reference to name.
When the child was processed, it was labelled a free
variable. Now that all its enclosing scope have been
processed, the name is known to be a global or builtin. So
walk back down the child chain and set the name to be global
rather than free.
Be careful to stop if a child does not think the name is
free.
"""
self.globals[name] = 1
if self.frees.has_key(name):
del self.frees[name]
for child in self.children:
if child.check_name(name) == SC_FREE:
child.force_global(name)
def add_frees(self, names):
"""Process list of free vars from nested scope.
Returns a list of names that are either 1) declared global in the
parent or 2) undefined in a top-level parent. In either case,
the nested scope should treat them as globals.
"""
child_globals = []
for name in names:
sc = self.check_name(name)
if self.nested:
if sc == SC_UNKNOWN or sc == SC_FREE \
or isinstance(self, ClassScope):
self.frees[name] = 1
elif sc == SC_GLOBAL:
child_globals.append(name)
elif isinstance(self, FunctionScope) and sc == SC_LOCAL:
self.cells[name] = 1
else:
child_globals.append(name)
else:
if sc == SC_LOCAL:
self.cells[name] = 1
else:
child_globals.append(name)
return child_globals
def get_cell_vars(self):
return self.cells.keys()
class ModuleScope(Scope):
__super_init = Scope.__init__
def __init__(self):
self.__super_init("global", self)
class LambdaScope(Scope):
class FunctionScope(Scope):
pass
class LambdaScope(FunctionScope):
__super_init = Scope.__init__
__counter = 1
@ -86,9 +193,6 @@ class LambdaScope(Scope):
self.__counter += 1
self.__super_init("lambda.%d" % i, module, klass)
class FunctionScope(Scope):
pass
class ClassScope(Scope):
__super_init = Scope.__init__
@ -111,17 +215,24 @@ class SymbolVisitor:
for n in node.defaults:
self.visit(n, parent)
scope = FunctionScope(node.name, self.module, self.klass)
if parent.nested or isinstance(parent, FunctionScope):
scope.nested = 1
self.scopes[node] = scope
self._do_args(scope, node.argnames)
self.visit(node.code, scope)
self.handle_free_vars(scope, parent)
scope.DEBUG()
def visitLambda(self, node, parent):
for n in node.defaults:
self.visit(n, parent)
scope = LambdaScope(self.module, self.klass)
if parent.nested or isinstance(parent, FunctionScope):
scope.nested = 1
self.scopes[node] = scope
self._do_args(scope, node.argnames)
self.visit(node.code, scope)
self.handle_free_vars(scope, parent)
def _do_args(self, scope, args):
for name in args:
@ -130,16 +241,25 @@ class SymbolVisitor:
else:
scope.add_param(name)
def handle_free_vars(self, scope, parent):
parent.add_child(scope)
if scope.children:
scope.DEBUG()
scope.handle_children()
def visitClass(self, node, parent):
parent.add_def(node.name)
for n in node.bases:
self.visit(n, parent)
scope = ClassScope(node.name, self.module)
if parent.nested or isinstance(parent, FunctionScope):
scope.nested = 1
self.scopes[node] = scope
prev = self.klass
self.klass = node.name
self.visit(node.code, scope)
self.klass = prev
self.handle_free_vars(scope, parent)
# name can be a def or a use