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"""
Generate AST node definitions from an ASDL description.
"""
import sys
import os
import asdl
class ASDLVisitor(asdl.VisitorBase):
def __init__(self, stream, data):
super(ASDLVisitor, self).__init__()
self.stream = stream
self.data = data
def visitModule(self, mod, *args):
for df in mod.dfns:
self.visit(df, *args)
def visitSum(self, sum, *args):
for tp in sum.types:
self.visit(tp, *args)
def visitType(self, tp, *args):
self.visit(tp.value, *args)
def visitProduct(self, prod, *args):
for field in prod.fields:
self.visit(field, *args)
def visitConstructor(self, cons, *args):
for field in cons.fields:
self.visit(field, *args)
def visitField(self, field):
pass
def emit(self, line, level=0):
indent = " "*level
self.stream.write(indent + line + "\n")
def is_simple_sum(sum):
assert isinstance(sum, asdl.Sum)
for constructor in sum.types:
if constructor.fields:
return False
return True
class ASTNodeVisitor(ASDLVisitor):
def visitType(self, tp):
self.visit(tp.value, tp.name)
def visitSum(self, sum, base):
if is_simple_sum(sum):
self.emit("class %s(AST):" % (base,))
self.emit("")
self.emit("def to_simple_int(self, space):", 1)
self.emit("w_msg = space.wrap(\"not a valid %s\")" % (base,), 2)
self.emit("raise OperationError(space.w_TypeError, w_msg)", 2)
self.emit("")
for i, cons in enumerate(sum.types):
self.emit("class _%s(%s):" % (cons.name, base))
self.emit("")
self.emit("def to_simple_int(self, space):", 1)
self.emit("return %i" % (i + 1,), 2)
self.emit("")
for i, cons in enumerate(sum.types):
self.emit("%s = %i" % (cons.name, i + 1))
self.emit("")
self.emit("%s_to_class = [" % (base,))
for cons in sum.types:
self.emit("_%s," % (cons.name,), 1)
self.emit("]")
self.emit("")
else:
self.emit("class %s(AST):" % (base,))
self.emit("")
slots = ", ".join(repr(attr.name.value) for attr in sum.attributes)
self.emit("__slots__ = (%s)" % (slots,), 1)
self.emit("")
if sum.attributes:
args = ", ".join(attr.name.value for attr in sum.attributes)
self.emit("def __init__(self, %s):" % (args,), 1)
for attr in sum.attributes:
self.visit(attr)
self.emit("")
for cons in sum.types:
self.visit(cons, base, sum.attributes)
self.emit("")
def visitProduct(self, product, name):
self.emit("class %s(AST):" % (name,))
self.emit("")
slots = self.make_slots(product.fields)
self.emit("__slots__ = (%s)" % (slots,), 1)
self.emit("")
self.make_constructor(product.fields, product)
self.emit("")
self.emit("def walkabout(self, visitor):", 1)
self.emit("visitor.visit_%s(self)" % (name,), 2)
self.emit("")
self.make_var_syncer(product.fields, product, name)
def make_slots(self, fields):
slots = []
for field in fields:
name = repr(field.name.value)
slots.append(name)
if field.seq:
slots.append("'w_%s'" % (field.name,))
return ", ".join(slots)
def make_var_syncer(self, fields, node, name):
self.emit("def sync_app_attrs(self, space):", 1)
config = (self.data.optional_masks[node],
self.data.required_masks[node])
self.emit("if (self.initialization_state & ~%i) ^ %i:" % config, 2)
names = []
for field in fields:
if field.opt:
names.append("None")
else:
names.append(repr(field.name.value))
sub = (", ".join(names), name.value)
self.emit("missing_field(space, self.initialization_state, [%s], %r)"
% sub, 3)
self.emit("else:", 2)
# Fill in all the default fields.
doing_something = False
for field in fields:
if field.opt:
doing_something = True
flag = self.data.field_masks[field]
self.emit("if not self.initialization_state & %i:" % (flag,), 3)
default = "0" if field.type.value == "int" else "None"
self.emit("self.%s = %s" % (field.name, default), 4)
if not doing_something:
self.emit("pass", 3)
for attr in fields:
if attr.seq:
self.emit("w_list = self.w_%s" % (attr.name,), 2)
self.emit("if w_list is not None:", 2)
self.emit("list_w = space.viewiterable(w_list)", 3)
self.emit("if list_w:", 3)
unwrapper = get_unwrapper(attr.type.value, "w_obj",
self.data.simple_types)
config = (attr.name, unwrapper)
self.emit("self.%s = [%s for w_obj in list_w]" % config,
4),
self.emit("else:", 3)
self.emit("self.%s = None" % (attr.name,), 4)
if attr.type.value not in asdl.builtin_types and \
attr.type.value not in self.data.simple_types:
self.emit("if self.%s is not None:" % (attr.name,), 2)
self.emit("for node in self.%s:" % (attr.name,), 3)
self.emit("node.sync_app_attrs(space)", 4)
elif attr.type.value not in asdl.builtin_types and \
attr.type.value not in self.data.simple_types:
doing_something = True
level = 2
if attr.opt:
self.emit("if self.%s:" % (attr.name,), 2)
level += 1
self.emit("self.%s.sync_app_attrs(space)" % (attr.name,), level)
self.emit("")
def make_constructor(self, fields, node, extras=None, base=None):
if fields or extras:
arg_fields = fields + extras if extras else fields
args = ", ".join(str(field.name) for field in arg_fields)
self.emit("def __init__(self, %s):" % args, 1)
for field in fields:
self.visit(field)
if extras:
base_args = ", ".join(str(field.name) for field in extras)
self.emit("%s.__init__(self, %s)" % (base, base_args), 2)
else:
self.emit("def __init__(self):", 1)
have_everything = self.data.required_masks[node] | \
self.data.optional_masks[node]
self.emit("self.initialization_state = %i" % (have_everything,), 2)
def visitConstructor(self, cons, base, extra_attributes):
self.emit("class %s(%s):" % (cons.name, base))
self.emit("")
slots = self.make_slots(cons.fields)
self.emit("__slots__ = (%s)" % (slots,), 1)
self.emit("")
for field in self.data.cons_attributes[cons]:
subst = (field.name, self.data.field_masks[field])
self.emit("_%s_mask = %i" % subst, 1)
self.emit("")
self.make_constructor(cons.fields, cons, extra_attributes, base)
self.emit("")
self.emit("def walkabout(self, visitor):", 1)
self.emit("visitor.visit_%s(self)" % (cons.name,), 2)
self.emit("")
self.emit("def mutate_over(self, visitor):", 1)
for field in cons.fields:
if field.type.value not in asdl.builtin_types and \
field.type.value not in self.data.prod_simple:
if field.opt or field.seq:
level = 3
self.emit("if self.%s:" % (field.name,), 2)
else:
level = 2
if field.seq:
sub = (field.name,)
self.emit("visitor._mutate_sequence(self.%s)" % sub, level)
else:
sub = (field.name, field.name)
self.emit("self.%s = self.%s.mutate_over(visitor)" % sub,
level)
self.emit("return visitor.visit_%s(self)" % (cons.name,), 2)
self.emit("")
self.make_var_syncer(cons.fields + self.data.cons_attributes[cons],
cons, cons.name)
def visitField(self, field):
self.emit("self.%s = %s" % (field.name, field.name), 2)
if field.seq:
self.emit("self.w_%s = None" % (field.name,), 2)
class ASTVisitorVisitor(ASDLVisitor):
"""A meta visitor! :)"""
def visitModule(self, mod):
self.emit("class ASTVisitor(object):")
self.emit("")
self.emit("def visit_sequence(self, seq):", 1)
self.emit("for node in seq:", 2)
self.emit("node.walkabout(self)", 3)
self.emit("")
self.emit("def default_visitor(self, node):", 1)
self.emit("raise NodeVisitorNotImplemented", 2)
self.emit("")
self.emit("def _mutate_sequence(self, seq):", 1)
self.emit("for i in range(len(seq)):", 2)
self.emit("seq[i] = seq[i].mutate_over(self)", 3)
self.emit("")
super(ASTVisitorVisitor, self).visitModule(mod)
self.emit("")
def visitType(self, tp):
if not (isinstance(tp.value, asdl.Sum) and
is_simple_sum(tp.value)):
super(ASTVisitorVisitor, self).visitType(tp, tp.name)
def visitProduct(self, prod, name):
self.emit("def visit_%s(self, node):" % (name,), 1)
self.emit("return self.default_visitor(node)", 2)
def visitConstructor(self, cons, _):
self.emit("def visit_%s(self, node):" % (cons.name,), 1)
self.emit("return self.default_visitor(node)", 2)
class GenericASTVisitorVisitor(ASDLVisitor):
def visitModule(self, mod):
self.emit("class GenericASTVisitor(ASTVisitor):")
self.emit("")
super(GenericASTVisitorVisitor, self).visitModule(mod)
self.emit("")
def visitType(self, tp):
if not (isinstance(tp.value, asdl.Sum) and
is_simple_sum(tp.value)):
super(GenericASTVisitorVisitor, self).visitType(tp, tp.name)
def visitProduct(self, prod, name):
self.make_visitor(name, prod.fields)
def visitConstructor(self, cons, _):
self.make_visitor(cons.name, cons.fields)
def make_visitor(self, name, fields):
self.emit("def visit_%s(self, node):" % (name,), 1)
have_body = False
for field in fields:
if self.visitField(field):
have_body = True
if not have_body:
self.emit("pass", 2)
self.emit("")
def visitField(self, field):
if field.type.value not in asdl.builtin_types and \
field.type.value not in self.data.simple_types:
if field.seq or field.opt:
self.emit("if node.%s:" % (field.name,), 2)
level = 3
else:
level = 2
if field.seq:
template = "self.visit_sequence(node.%s)"
else:
template = "node.%s.walkabout(self)"
self.emit(template % (field.name,), level)
return True
return False
asdl_type_map = {
"int" : "int_w",
"identifier" : "str_w",
"bool" : "bool_w"
}
def get_unwrapper(tp, name, simple_types):
if tp in asdl.builtin_types:
return "space.%s(%s)" % (asdl_type_map[tp], name)
elif tp in simple_types:
return "space.interp_w(%s, %s).to_simple_int(space)" % (tp, name)
else:
return "space.interp_w(%s, %s)" % (tp, name)
# CPython lets blank AST nodes (no constructor arguments) be created
# and the attributes added later. In CPython, it is implemented by
# implementing applevel and c level AST as different structures and
# copying between them. This is hideous, so we use a slightly less
# ugly hack in PyPy. Each field has a bitmask which is set on the
# initialization_state attribute when the field type is set. When
# sync_app_attrs() is called, it's a simple matter of removing the
# optional field flags from initialization_state, and using XOR to
# test if all the required fields have been set.
class AppExposeVisitor(ASDLVisitor):
def visitType(self, tp):
super(AppExposeVisitor, self).visitType(tp, tp.name)
def visitSum(self, sum, name):
for field in sum.attributes:
self.make_property(field, name, True)
self.make_typedef(name, "AST", sum.attributes,
fields_name="_attributes")
if not is_simple_sum(sum):
super(AppExposeVisitor, self).visitSum(sum, name)
else:
for cons in sum.types:
self.make_typedef("_" + cons.name.value, name, (), cons.name,
concrete=True)
def make_typedef(self, name, base, fields, display_name=None,
fields_name="_fields", concrete=False, needs_init=False):
if display_name is None:
display_name = name
self.emit("%s.typedef = typedef.TypeDef(\"%s\"," % (name, display_name))
self.emit("%s.typedef," % (base,), 1)
comma_fields = ", ".join(repr(field.name.value) for field in fields)
self.emit("%s=_FieldsWrapper([%s])," % (fields_name, comma_fields), 1)
for field in fields:
getter = "%s_get_%s" % (name, field.name)
setter = "%s_set_%s" % (name, field.name)
config = (field.name, getter, setter, name)
self.emit("%s=typedef.GetSetProperty(%s, %s, cls=%s)," % config, 1)
# CPython lets you create instances of "abstract" AST nodes
# like ast.expr or even ast.AST. This doesn't seem to useful
# and would be a pain to implement safely, so we don't allow
# it.
if concrete:
self.emit("__new__=interp2app(get_AST_new(%s))," % (name,), 1)
if needs_init:
self.emit("__init__=interp2app(%s_init)," % (name,), 1)
self.emit(")")
self.emit("%s.typedef.acceptable_as_base_class = False" % (name,))
self.emit("")
def make_init(self, name, fields):
comma_fields = ", ".join(repr(field.name.value) for field in fields)
config = (name, comma_fields)
self.emit("_%s_field_unroller = unrolling_iterable([%s])" % config)
self.emit("def %s_init(space, w_self, args):" % (name,))
self.emit("w_self = space.descr_self_interp_w(%s, w_self)" % (name,), 1)
for field in fields:
if field.seq:
self.emit("w_self.w_%s = None" % (field.name,), 1)
self.emit("args_w, kwargs_w = args.unpack()", 1)
self.emit("if args_w:", 1)
arity = len(fields)
if arity:
self.emit("if len(args_w) != %i:" % (arity,), 2)
self.emit("w_err = space.wrap(\"%s constructor takes 0 or %i " \
"positional arguments\")" % (name, arity), 3)
self.emit("raise OperationError(space.w_TypeError, w_err)", 3)
self.emit("i = 0", 2)
self.emit("for field in _%s_field_unroller:" % (name,), 2)
self.emit("space.setattr(w_self, space.wrap(field), args_w[i])", 3)
self.emit("i += 1", 3)
else:
self.emit("w_err = space.wrap(\"%s constructor takes no " \
" arguments\")" % (name,), 2)
self.emit("raise OperationError(space.w_TypeError, w_err)", 2)
self.emit("for field, w_value in kwargs_w.iteritems():", 1)
self.emit("space.setattr(w_self, space.wrap(field), w_value)", 2)
self.emit("%s_init.unwrap_spec = [ObjSpace, W_Root, Arguments]"
% (name,))
self.emit("")
def visitConstructor(self, cons, base):
super(AppExposeVisitor, self).visitConstructor(cons, cons.name)
self.make_init(cons.name, cons.fields + self.data.cons_attributes[cons])
self.make_typedef(cons.name, base, cons.fields, concrete=True,
needs_init=True)
def visitProduct(self, product, name):
super(AppExposeVisitor, self).visitProduct(product, name)
self.make_init(name, product.fields)
self.make_typedef(name, "AST", product.fields, concrete=True,
needs_init=True)
def visitField(self, field, name):
self.make_property(field, name)
def make_property(self, field, name, different_masks=False):
func = "def %s_get_%s(space, w_self):" % (name, field.name)
self.emit(func)
if different_masks:
flag = "w_self._%s_mask" % (field.name,)
else:
flag = self.data.field_masks[field]
self.emit("if not w_self.initialization_state & %s:" % (flag,), 1)
self.emit("w_err = space.wrap(\"attribute '%s' has not been set\")" %
(field.name,), 2)
self.emit("raise OperationError(space.w_AttributeError, w_err)", 2)
if field.seq:
self.emit("if w_self.w_%s is None:" % (field.name,), 1)
self.emit("if w_self.%s is None:" % (field.name,), 2)
self.emit("w_list = space.newlist([])", 3)
self.emit("else:", 2)
if field.type.value in self.data.simple_types:
wrapper = "%s_to_class[node - 1]()" % (field.type,)
else:
wrapper = "space.wrap(node)"
self.emit("list_w = [%s for node in w_self.%s]" %
(wrapper, field.name), 3)
self.emit("w_list = space.newlist(list_w)", 3)
self.emit("w_self.w_%s = w_list" % (field.name,), 2)
self.emit("return w_self.w_%s" % (field.name,), 1)
elif field.type.value in self.data.simple_types:
config = (field.type, field.name)
self.emit("return %s_to_class[w_self.%s - 1]()" % config, 1)
elif field.type.value in ("object", "string"):
self.emit("return w_self.%s" % (field.name,), 1)
else:
self.emit("return space.wrap(w_self.%s)" % (field.name,), 1)
self.emit("")
func = "def %s_set_%s(space, w_self, w_new_value):" % (name, field.name)
self.emit(func)
if field.seq:
self.emit("w_self.w_%s = w_new_value" % (field.name,), 1)
elif field.type.value not in asdl.builtin_types:
# These are always other AST nodes.
if field.type.value in self.data.simple_types:
self.emit("obj = space.interp_w(%s, w_new_value)" % \
(field.type,), 1)
self.emit("w_self.%s = obj.to_simple_int(space)" %
(field.name,), 1)
else:
config = (field.name, field.type, repr(field.opt))
self.emit("w_self.%s = space.interp_w(%s, w_new_value, %s)" %
config, 1)
else:
level = 1
if field.opt and field.type.value != "int":
self.emit("if space.is_w(w_new_value, space.w_None):", 1)
self.emit("w_self.%s = None" % (field.name,), 2)
level += 1
self.emit("else:", 1)
if field.type.value == "object":
self.emit("w_self.%s = w_new_value" % (field.name,), level)
elif field.type.value == "string":
self.emit("if not space.is_true(space.isinstance(" \
"w_new_value, space.w_basestring)):", level)
line = "w_err = space.wrap(\"some kind of string required\")"
self.emit(line, level + 1)
self.emit("raise OperationError(space.w_TypeError, w_err)",
level + 1)
self.emit("w_self.%s = w_new_value" % (field.name,), level)
else:
space_method = asdl_type_map[field.type.value]
config = (field.name, space_method)
self.emit("w_self.%s = space.%s(w_new_value)" % config, level)
self.emit("w_self.initialization_state |= %s" % (flag,), 1)
self.emit("")
def copy_field(field):
return asdl.Field(field.type, field.name, field.seq, field.opt)
class ASDLData(object):
def __init__(self, tree):
simple_types = set()
prod_simple = set()
field_masks = {}
required_masks = {}
optional_masks = {}
cons_attributes = {}
def add_masks(fields, node):
required_mask = 0
optional_mask = 0
for i, field in enumerate(fields):
flag = 1 << i
field_masks[field] = flag
if field.opt:
optional_mask |= flag
else:
required_mask |= flag
required_masks[node] = required_mask
optional_masks[node] = optional_mask
for tp in tree.dfns:
if isinstance(tp.value, asdl.Sum):
sum = tp.value
if is_simple_sum(sum):
simple_types.add(tp.name.value)
else:
for cons in sum.types:
attrs = [copy_field(field) for field in sum.attributes]
add_masks(cons.fields + attrs, cons)
cons_attributes[cons] = attrs
else:
prod = tp.value
prod_simple.add(tp.name.value)
add_masks(prod.fields, prod)
prod_simple.update(simple_types)
self.cons_attributes = cons_attributes
self.simple_types = simple_types
self.prod_simple = prod_simple
self.field_masks = field_masks
self.required_masks = required_masks
self.optional_masks = optional_masks
HEAD = """# Generated by tools/asdl_py.py
from pypy.interpreter.baseobjspace import Wrappable, ObjSpace, W_Root
from pypy.interpreter import typedef
from pypy.interpreter.gateway import interp2app
from pypy.interpreter.argument import Arguments
from pypy.interpreter.error import OperationError
from pypy.rlib.unroll import unrolling_iterable
from pypy.tool.pairtype import extendabletype
from pypy.tool.sourcetools import func_with_new_name
class AST(Wrappable):
__slots__ = ("initialization_state",)
__metaclass__ = extendabletype
def walkabout(self, visitor):
raise AssertionError("walkabout() implementation not provided")
def mutate_over(self, visitor):
raise AssertionError("mutate_over() implementation not provided")
def sync_app_attrs(self, space):
raise NotImplementedError
class NodeVisitorNotImplemented(Exception):
pass
class _FieldsWrapper(Wrappable):
"Hack around the fact we can't store tuples on a TypeDef."
def __init__(self, fields):
self.fields = fields
def __spacebind__(self, space):
return space.newtuple([space.wrap(field) for field in self.fields])
def get_AST_new(node_class):
def generic_AST_new(space, w_type, __args__):
node = space.allocate_instance(node_class, w_type)
node.initialization_state = 0
return space.wrap(node)
generic_AST_new.unwrap_spec = [ObjSpace, W_Root, Arguments]
return func_with_new_name(generic_AST_new, "new_%s" % node_class.__name__)
AST.typedef = typedef.TypeDef("AST",
_fields=_FieldsWrapper([]),
_attributes=_FieldsWrapper([]),
)
AST.typedef.acceptable_as_base_class = False
def missing_field(space, state, required, host):
"Find which required field is missing."
for i in range(len(required)):
if not (state >> i) & 1:
missing = required[i]
if missing is not None:
err = "required attribute '%s' missing from %s"
err = err % (missing, host)
w_err = space.wrap(err)
raise OperationError(space.w_TypeError, w_err)
raise AssertionError("should not reach here")
"""
visitors = [ASTNodeVisitor, ASTVisitorVisitor, GenericASTVisitorVisitor,
AppExposeVisitor]
def main(argv):
if len(argv) == 3:
def_file, out_file = argv[1:]
elif len(argv) == 1:
print "Assuming default values of Python.asdl and ast.py"
here = os.path.dirname(__file__)
def_file = os.path.join(here, "Python.asdl")
out_file = os.path.join(here, "..", "ast.py")
else:
print >> sys.stderr, "invalid arguments"
return 2
mod = asdl.parse(def_file)
data = ASDLData(mod)
fp = open(out_file, "w")
try:
fp.write(HEAD)
for visitor in visitors:
visitor(fp, data).visit(mod)
finally:
fp.close()
if __name__ == "__main__":
sys.exit(main(sys.argv))