Source code for apache_beam.typehints.opcodes

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"""Defines the actions various bytecodes have on the frame.

Each function here corresponds to a bytecode documented in
https://docs.python.org/2/library/dis.html or
https://docs.python.org/3/library/dis.html. The first argument is a (mutable)
FrameState object, the second the integer opcode argument.

Bytecodes with more complicated behavior (e.g. modifying the program counter)
are handled inline rather than here.

For internal use only; no backwards-compatibility guarantees.
"""
# pytype: skip-file

from __future__ import absolute_import

import inspect
import logging
import sys
import types
from functools import reduce

from past.builtins import unicode

from apache_beam.typehints import row_type
from apache_beam.typehints import typehints
from apache_beam.typehints.trivial_inference import BoundMethod
from apache_beam.typehints.trivial_inference import Const
from apache_beam.typehints.trivial_inference import element_type
from apache_beam.typehints.trivial_inference import union
from apache_beam.typehints.typehints import Any
from apache_beam.typehints.typehints import Dict
from apache_beam.typehints.typehints import Iterable
from apache_beam.typehints.typehints import List
from apache_beam.typehints.typehints import Tuple
from apache_beam.typehints.typehints import Union

# This is missing in the builtin types module.  str.upper is arbitrary, any
# method on a C-implemented type will do.
_MethodDescriptorType = type(str.upper)


[docs]def pop_one(state, unused_arg): del state.stack[-1:]
[docs]def pop_two(state, unused_arg): del state.stack[-2:]
[docs]def pop_three(state, unused_arg): del state.stack[-3:]
[docs]def push_value(v): def pusher(state, unused_arg): state.stack.append(v) return pusher
[docs]def nop(unused_state, unused_arg): pass
[docs]def pop_top(state, unused_arg): state.stack.pop()
[docs]def rot_n(state, n): state.stack[-n:] = [state.stack[-1]] + state.stack[-n:-1]
[docs]def rot_two(state, unused_arg): rot_n(state, 2)
[docs]def rot_three(state, unused_arg): rot_n(state, 3)
[docs]def rot_four(state, unused_arg): rot_n(state, 4)
[docs]def dup_top(state, unused_arg): state.stack.append(state.stack[-1])
[docs]def unary(state, unused_arg): state.stack[-1] = Const.unwrap(state.stack[-1])
unary_positive = unary_negative = unary_invert = unary
[docs]def unary_not(state, unused_arg): state.stack[-1] = bool
[docs]def unary_convert(state, unused_arg): state.stack[-1] = str
[docs]def get_iter(state, unused_arg): state.stack.append(Iterable[element_type(state.stack.pop())])
[docs]def symmetric_binary_op(state, unused_arg): # TODO(robertwb): This may not be entirely correct... b, a = Const.unwrap(state.stack.pop()), Const.unwrap(state.stack.pop()) if a == b: state.stack.append(a) elif type(a) == type(b) and isinstance(a, typehints.SequenceTypeConstraint): state.stack.append(type(a)(union(element_type(a), element_type(b)))) else: state.stack.append(Any)
# Except for int ** -int binary_power = inplace_power = symmetric_binary_op binary_multiply = inplace_multiply = symmetric_binary_op binary_divide = inplace_divide = symmetric_binary_op binary_floor_divide = inplace_floor_divide = symmetric_binary_op
[docs]def binary_true_divide(state, unused_arg): u = union(state.stack.pop(), state.stack.pop) if u == int: state.stack.append(float) else: state.stack.append(u)
inplace_true_divide = binary_true_divide binary_modulo = inplace_modulo = symmetric_binary_op # TODO(robertwb): Tuple add. binary_add = inplace_add = symmetric_binary_op binary_subtract = inplace_subtract = symmetric_binary_op
[docs]def binary_subscr(state, unused_arg): index = state.stack.pop() base = Const.unwrap(state.stack.pop()) if base in (str, unicode): out = base elif (isinstance(index, Const) and isinstance(index.value, int) and isinstance(base, typehints.IndexableTypeConstraint)): try: out = base._constraint_for_index(index.value) except IndexError: out = element_type(base) elif index == slice and isinstance(base, typehints.IndexableTypeConstraint): out = base else: out = element_type(base) state.stack.append(out)
# As far as types are concerned. binary_lshift = inplace_lshift = binary_rshift = inplace_rshift = pop_top binary_and = inplace_and = symmetric_binary_op binary_xor = inplace_xor = symmetric_binary_op binary_or = inpalce_or = symmetric_binary_op
[docs]def store_subscr(unused_state, unused_args): # TODO(robertwb): Update element/value type of iterable/dict. pass
print_item = pop_top print_newline = nop
[docs]def list_append(state, arg): new_element_type = Const.unwrap(state.stack.pop()) state.stack[-arg] = List[Union[element_type(state.stack[-arg]), new_element_type]]
[docs]def map_add(state, arg): if sys.version_info >= (3, 8): # PEP 572 The MAP_ADD expects the value as the first element in the stack # and the key as the second element. new_value_type = Const.unwrap(state.stack.pop()) new_key_type = Const.unwrap(state.stack.pop()) else: new_key_type = Const.unwrap(state.stack.pop()) new_value_type = Const.unwrap(state.stack.pop()) state.stack[-arg] = Dict[Union[state.stack[-arg].key_type, new_key_type], Union[state.stack[-arg].value_type, new_value_type]]
load_locals = push_value(Dict[str, Any]) exec_stmt = pop_three build_class = pop_three
[docs]def unpack_sequence(state, arg): t = state.stack.pop() if isinstance(t, Const): try: unpacked = [Const(ti) for ti in t.value] if len(unpacked) != arg: unpacked = [Any] * arg except TypeError: unpacked = [Any] * arg elif (isinstance(t, typehints.TupleHint.TupleConstraint) and len(t.tuple_types) == arg): unpacked = list(t.tuple_types) else: unpacked = [element_type(t)] * arg state.stack += reversed(unpacked)
[docs]def dup_topx(state, arg): state.stack += state[-arg:]
store_attr = pop_top delete_attr = nop store_global = pop_top delete_global = nop
[docs]def load_const(state, arg): state.stack.append(state.const_type(arg))
load_name = push_value(Any)
[docs]def build_tuple(state, arg): if arg == 0: state.stack.append(Tuple[()]) else: state.stack[-arg:] = [Tuple[[Const.unwrap(t) for t in state.stack[-arg:]]]]
[docs]def build_list(state, arg): if arg == 0: state.stack.append(List[Union[()]]) else: state.stack[-arg:] = [List[reduce(union, state.stack[-arg:], Union[()])]]
# A Dict[Union[], Union[]] is the type of an empty dict.
[docs]def build_map(state, arg): if arg == 0: state.stack.append(Dict[Union[()], Union[()]]) else: state.stack[-2 * arg:] = [ Dict[reduce(union, state.stack[-2 * arg::2], Union[()]), reduce(union, state.stack[-2 * arg + 1::2], Union[()])] ]
[docs]def build_const_key_map(state, arg): key_tuple = state.stack.pop() if isinstance(key_tuple, typehints.TupleHint.TupleConstraint): key_types = key_tuple.tuple_types elif isinstance(key_tuple, Const): key_types = [Const(v) for v in key_tuple.value] else: key_types = [Any] state.stack[-arg:] = [ Dict[reduce(union, key_types, Union[()]), reduce(union, state.stack[-arg:], Union[()])] ]
[docs]def load_attr(state, arg): """Replaces the top of the stack, TOS, with getattr(TOS, co_names[arg]) Will replace with Any for builtin methods, but these don't have bytecode in CPython so that's okay. """ o = state.stack.pop() name = state.get_name(arg) state.stack.append(_getattr(o, name))
def _getattr(o, name): if isinstance(o, Const) and hasattr(o.value, name): return Const(getattr(o.value, name)) elif (inspect.isclass(o) and isinstance(getattr(o, name, None), (types.MethodType, types.FunctionType))): # TODO(luke-zhu): Support other callable objects func = getattr(o, name) # Python 3 has no unbound methods return Const(BoundMethod(func, o)) elif isinstance(o, row_type.RowTypeConstraint): return o.get_type_for(name) else: return Any
[docs]def load_method(state, arg): """Like load_attr. Replaces TOS object with method and TOS.""" o = state.stack.pop() name = state.get_name(arg) if isinstance(o, Const): method = Const(getattr(o.value, name)) elif isinstance(o, typehints.AnyTypeConstraint): method = typehints.Any elif hasattr(o, name): attr = getattr(o, name) if isinstance(attr, _MethodDescriptorType): # Skip builtins since they don't disassemble. method = typehints.Any else: method = Const(BoundMethod(attr, o)) else: method = typehints.Any state.stack.append(method)
[docs]def compare_op(state, unused_arg): # Could really be anything... state.stack[-2:] = [bool]
[docs]def import_name(state, unused_arg): state.stack[-2:] = [Any]
import_from = push_value(Any)
[docs]def load_global(state, arg): state.stack.append(state.get_global(arg))
store_map = pop_two
[docs]def load_fast(state, arg): state.stack.append(state.vars[arg])
[docs]def store_fast(state, arg): state.vars[arg] = state.stack.pop()
[docs]def delete_fast(state, arg): state.vars[arg] = Any # really an error
[docs]def load_closure(state, arg): state.stack.append(state.get_closure(arg))
[docs]def load_deref(state, arg): state.stack.append(state.closure_type(arg))
[docs]def make_function(state, arg): """Creates a function with the arguments at the top of the stack. """ # TODO(luke-zhu): Handle default argument types globals = state.f.__globals__ # Inherits globals from the current frame func_name = state.stack[-1].value func_code = state.stack[-2].value pop_count = 2 closure = None # arg contains flags, with corresponding stack values if positive. # https://docs.python.org/3.6/library/dis.html#opcode-MAKE_FUNCTION pop_count += bin(arg).count('1') if arg & 0x08: # Convert types in Tuple constraint to a tuple of CPython cells. # https://stackoverflow.com/a/44670295 closure = tuple((lambda _: lambda: _)(t).__closure__[0] for t in state.stack[-3].tuple_types) func = types.FunctionType(func_code, globals, name=func_name, closure=closure) assert pop_count <= len(state.stack) state.stack[-pop_count:] = [Const(func)]
[docs]def make_closure(state, arg): state.stack[-arg - 2:] = [Any] # a callable
[docs]def build_slice(state, arg): state.stack[-arg:] = [slice] # a slice object
def _unpack_lists(state, arg): """Extract inner types of Lists and Tuples. Pops arg count items from the stack, concatenates their inner types into 1 list, and returns that list. Example: if stack[-arg:] == [[i1, i2], [i3]], the output is [i1, i2, i3] """ types = [] for i in range(arg, 0, -1): type_constraint = state.stack[-i] if isinstance(type_constraint, typehints.IndexableTypeConstraint): types.extend(type_constraint._inner_types()) else: logging.debug('Unhandled type_constraint: %r', type_constraint) types.append(typehints.Any) state.stack[-arg:] = [] return types
[docs]def build_list_unpack(state, arg): """Joins arg count iterables from the stack into a single list.""" state.stack.append(List[Union[_unpack_lists(state, arg)]])
[docs]def build_tuple_unpack(state, arg): """Joins arg count iterables from the stack into a single tuple.""" state.stack.append(Tuple[_unpack_lists(state, arg)])
[docs]def build_tuple_unpack_with_call(state, arg): """Same as build_tuple_unpack, with an extra fn argument at the bottom of the stack, which remains untouched.""" build_tuple_unpack(state, arg)