pytorch/torch/jit/annotations.py
Meghan Lele 75bf5f2b59 [JIT] Improve class type annotation inference (#45940)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/45940

**Summary**
In `try_ann_to_type`, if an annotation has an attribute named
`__torch_script_class__`, it is assumed to be a TorchScript class that
has already been scripted. However, if it is a class that extends
another class, this code path causes a crash because it looks up the
JIT type for the class by name in the compilation unit. This JIT type
obviously cannot exist because inheritance is not supported.

This commit fixes this by looking up the qualified name of a class
in torch.jit._state._script_class in order to ascertain whether it has
already been scripted (instead of looking for a `__torch_script_class__`
attribute on the class object.

**Test Plan**
This commit adds a unit test consisting of the code sample from the
issue that reported this problem.

**Fixes**
This commit fixes #45860.

Test Plan: Imported from OSS

Reviewed By: anjali411

Differential Revision: D24310027

Pulled By: SplitInfinity

fbshipit-source-id: 9f8225f3316fd50738d98e3544bf5562b16425b6
2020-10-14 23:28:47 -07:00

380 lines
14 KiB
Python

import ast
import enum
import inspect
import re
import torch
from .._jit_internal import List, Tuple, is_tuple, is_list, Dict, is_dict, Optional, \
is_optional, _qualified_name, Any, Future, is_future, is_ignored_fn
from .._jit_internal import BroadcastingList1, BroadcastingList2, BroadcastingList3 # type: ignore
from ._state import _get_script_class
from torch._C import TensorType, TupleType, FloatType, IntType, \
ListType, StringType, DictType, BoolType, OptionalType, ClassType, InterfaceType, AnyType, NoneType, \
DeviceObjType, StreamObjType, FutureType, EnumType
from textwrap import dedent
from torch._six import builtins
from torch._utils_internal import get_source_lines_and_file
from typing import Type
if torch.distributed.rpc.is_available():
from .._jit_internal import RRef, is_rref
from torch._C import RRefType
class Module(object):
def __init__(self, name, members):
self.name = name
self.members = members
def __getattr__(self, name):
try:
return self.members[name]
except KeyError:
raise RuntimeError(f"Module {self.name} has no member called {name}") from None
class EvalEnv(object):
env = {
'torch': Module('torch', {'Tensor': torch.Tensor}),
'Tensor': torch.Tensor,
'typing': Module('typing', {'Tuple': Tuple}),
'Tuple': Tuple,
'List': List,
'Dict': Dict,
'Optional': Optional,
'Future': Future,
}
def __init__(self, rcb):
self.rcb = rcb
if torch.distributed.rpc.is_available():
self.env['RRef'] = RRef
def __getitem__(self, name):
if name in self.env:
return self.env[name]
if self.rcb is not None:
return self.rcb(name)
return getattr(builtins, name, None)
def get_signature(fn, rcb, loc, is_method):
signature = try_real_annotations(fn, loc)
if signature is not None and is_method:
# If this is a method, then the signature will include a type for
# `self`, but type comments do not contain a `self`. So strip it
# away here so everything is consistent (`inspect.ismethod` does
# not work here since `fn` is unbound at this point)
param_types, return_type = signature
param_types = param_types[1:]
signature = (param_types, return_type)
if signature is None:
type_line, source = None, None
try:
source = dedent(''.join(get_source_lines_and_file(fn)[0]))
type_line = get_type_line(source)
except TypeError:
pass
# This might happen both because we failed to get the source of fn, or
# because it didn't have any annotations.
if type_line is not None:
signature = parse_type_line(type_line, rcb, loc)
return signature
def is_function_or_method(the_callable):
# A stricter version of `inspect.isroutine` that does not pass for built-in
# functions
return inspect.isfunction(the_callable) or inspect.ismethod(the_callable)
def is_vararg(the_callable):
if not is_function_or_method(the_callable) and hasattr(the_callable, '__call__'): # noqa: B004
# If `the_callable` is a class, de-sugar the call so we can still get
# the signature
the_callable = the_callable.__call__
if is_function_or_method(the_callable):
return inspect.getfullargspec(the_callable).varargs is not None
else:
return False
def get_param_names(fn, n_args):
if not is_function_or_method(fn) and hasattr(fn, '__call__') and is_function_or_method(fn.__call__): # noqa: B004
# De-sugar calls to classes
fn = fn.__call__
if is_function_or_method(fn):
if is_ignored_fn(fn):
fn = inspect.unwrap(fn)
return inspect.getfullargspec(fn).args
else:
# The `fn` was not a method or function (maybe a class with a __call__
# method, so use a default param name list)
return [str(i) for i in range(n_args)]
def check_fn(fn, loc):
# Make sure the function definition is not a class instantiation
try:
source = dedent(''.join(get_source_lines_and_file(fn)[0]))
except (TypeError, IOError):
return
if source is None:
return
py_ast = ast.parse(source)
if len(py_ast.body) == 1 and isinstance(py_ast.body[0], ast.ClassDef):
raise torch.jit.frontend.FrontendError(
loc, f"Cannot instantiate class '{py_ast.body[0].name}' in a script function")
if len(py_ast.body) != 1 or not isinstance(py_ast.body[0], ast.FunctionDef):
raise torch.jit.frontend.FrontendError(loc, "Expected a single top-level function")
def parse_type_line(type_line, rcb, loc):
"""Parses a type annotation specified as a comment.
Example inputs:
# type: (Tensor, torch.Tensor) -> Tuple[Tensor]
# type: (Tensor, Tuple[Tensor, Tensor]) -> Tensor
"""
arg_ann_str, ret_ann_str = split_type_line(type_line)
try:
arg_ann = eval(arg_ann_str, {}, EvalEnv(rcb)) # type: ignore # noqa: P204
except (NameError, SyntaxError) as e:
raise RuntimeError("Failed to parse the argument list of a type annotation") from e
if not isinstance(arg_ann, tuple):
arg_ann = (arg_ann,)
try:
ret_ann = eval(ret_ann_str, {}, EvalEnv(rcb)) # type: ignore # noqa: P204
except (NameError, SyntaxError) as e:
raise RuntimeError("Failed to parse the return type of a type annotation") from e
arg_types = [ann_to_type(ann, loc) for ann in arg_ann]
return arg_types, ann_to_type(ret_ann, loc)
def get_type_line(source):
"""Tries to find the line containing a comment with the type annotation."""
type_comment = '# type:'
lines = source.split('\n')
lines = [(line_num, line) for line_num, line in enumerate(lines)]
type_lines = list(filter(lambda line: type_comment in line[1], lines))
# `type: ignore` comments may be needed in JIT'ed functions for mypy, due
# to the hack in torch/_VF.py.
type_lines = list(filter(lambda line: not line[1].endswith("# type: ignore"),
type_lines))
lines_with_type = list(filter(lambda line: 'type' in line[1], lines))
if len(type_lines) == 0:
type_pattern = re.compile('#[\t ]*type[\t ]*(?!: ignore$):')
wrong_type_lines = list(filter(lambda line: type_pattern.search(line[1]), lines))
if len(wrong_type_lines) > 0:
raise RuntimeError("The annotation prefix in line " + str(wrong_type_lines[0][0])
+ " is probably invalid.\nIt must be '# type:'"
+ "\nSee PEP 484 (https://www.python.org/dev/peps/pep-0484/#suggested-syntax-for-python-2-7-and-straddling-code)" # noqa
+ "\nfor examples")
return None
elif len(type_lines) == 1:
# Only 1 type line, quit now
return type_lines[0][1].strip()
# Parse split up argument types according to PEP 484
# https://www.python.org/dev/peps/pep-0484/#suggested-syntax-for-python-2-7-and-straddling-code
return_line = None
parameter_type_lines = []
for line_num, line in type_lines:
if '# type: (...) -> ' in line:
return_line = (line_num, line)
break
elif type_comment in line:
parameter_type_lines.append(line)
if return_line is None:
raise RuntimeError(
"Return type line '# type: (...) -> ...' not found on multiline "
"type annotation\nfor type lines:\n" +
'\n'.join([line[1] for line in type_lines]) +
"\n(See PEP 484 https://www.python.org/dev/peps/pep-0484/#suggested-syntax-for-python-2-7-and-straddling-code)") # noqa
def get_parameter_type(line):
item_type = line[line.find(type_comment) + len(type_comment):]
return item_type.strip()
types = map(get_parameter_type, parameter_type_lines)
parameter_types = ", ".join(types)
return return_line[1].replace("...", parameter_types)
def split_type_line(type_line):
"""Splits the comment with the type annotation into parts for argument and return types.
For example, for an input of:
# type: (Tensor, torch.Tensor) -> Tuple[Tensor, Tensor]
This function will return:
("(Tensor, torch.Tensor)", "Tuple[Tensor, Tensor]")
"""
start_offset = len('# type:')
try:
arrow_pos = type_line.index('->')
except ValueError:
raise RuntimeError("Syntax error in type annotation (cound't find `->`)") from None
return type_line[start_offset:arrow_pos].strip(), type_line[arrow_pos + 2:].strip()
def try_real_annotations(fn, loc):
"""Tries to use the Py3.5+ annotation syntax to get the type."""
try:
sig = inspect.signature(fn)
except ValueError:
return None
all_annots = [sig.return_annotation] + [p.annotation for p in sig.parameters.values()]
if all(ann is sig.empty for ann in all_annots):
return None
def as_ann(ann):
# sig.empty is really annoying so convert it to None
return ann if ann is not sig.empty else None
arg_types = [ann_to_type(as_ann(p.annotation), loc)
for p in sig.parameters.values()]
return_type = ann_to_type(as_ann(sig.return_annotation), loc)
return arg_types, return_type
# Finds common type for enum values belonging to an Enum class. If not all
# values have the same type, AnyType is returned.
def get_enum_value_type(e: Type[enum.Enum], loc):
enum_values: List[enum.Enum] = list(e)
if not enum_values:
raise ValueError(f"No enum values defined for: '{e.__class__}'")
types = {type(v.value) for v in enum_values}
ir_types = [try_ann_to_type(t, loc) for t in types]
# If Enum values are of different types, an exception will be raised here.
# Even though Python supports this case, we chose to not implement it to
# avoid overcomplicate logic here for a rare use case. Please report a
# feature request if you find it necessary.
return torch._C.unify_type_list(ir_types)
def try_ann_to_type(ann, loc):
if ann is None:
return TensorType.getInferred()
if inspect.isclass(ann) and issubclass(ann, torch.Tensor):
return TensorType.get()
if is_tuple(ann):
return TupleType([try_ann_to_type(a, loc) for a in ann.__args__])
if is_list(ann):
elem_type = try_ann_to_type(ann.__args__[0], loc)
if elem_type:
return ListType(elem_type)
if is_dict(ann):
key = try_ann_to_type(ann.__args__[0], loc)
value = try_ann_to_type(ann.__args__[1], loc)
return DictType(key, value)
if is_optional(ann):
if issubclass(ann.__args__[1], type(None)):
contained = ann.__args__[0]
else:
contained = ann.__args__[1]
valid_type = try_ann_to_type(contained, loc)
msg = "Unsupported annotation {} could not be resolved because {} could not be resolved."
assert valid_type, msg.format(repr(ann), repr(contained))
return OptionalType(valid_type)
if torch.distributed.rpc.is_available() and is_rref(ann):
return RRefType(try_ann_to_type(ann.__args__[0], loc))
if is_future(ann):
return FutureType(try_ann_to_type(ann.__args__[0], loc))
if ann is float:
return FloatType.get()
if ann is int:
return IntType.get()
if ann is str:
return StringType.get()
if ann is bool:
return BoolType.get()
if ann is Any:
return AnyType.get()
if ann is type(None):
return NoneType.get()
if inspect.isclass(ann) and hasattr(ann, "__torch_script_interface__"):
return InterfaceType(_qualified_name(ann))
if ann is torch.device:
return DeviceObjType.get()
if ann is torch.Stream:
return StreamObjType.get()
if ann is torch.dtype:
return IntType.get() # dtype not yet bound in as its own type
if inspect.isclass(ann) and issubclass(ann, enum.Enum):
qualified_name = _qualified_name(ann)
if _get_script_class(qualified_name) is None:
torch.jit._script._recursive_compile_class(ann, loc)
return EnumType(_qualified_name(ann), get_enum_value_type(ann, loc), list(ann))
if inspect.isclass(ann):
qualified_name = _qualified_name(ann)
if _get_script_class(qualified_name) is not None:
return ClassType(qualified_name)
ignored_builtin_classes = (torch.nn.Module, tuple, list, Exception)
if torch._jit_internal.can_compile_class(ann) and not issubclass(ann, ignored_builtin_classes):
torch.jit._script._recursive_compile_class(ann, loc)
return ClassType(qualified_name)
# Maybe resolve a NamedTuple to a Tuple Type
def fake_rcb(key):
return None
return torch._C._resolve_type_from_object(ann, loc, fake_rcb)
def ann_to_type(ann, loc):
the_type = try_ann_to_type(ann, loc)
if the_type is not None:
return the_type
raise ValueError(f"Unknown type annotation: '{ann}'")
__all__ = [
'Any',
'List',
'BroadcastingList1',
'BroadcastingList2',
'BroadcastingList3',
'Tuple',
'is_tuple',
'is_list',
'Dict',
'is_dict',
'TensorType',
'TupleType',
'FloatType',
'IntType',
'ListType',
'StringType',
'DictType',
'AnyType',
'Module',
# TODO: Consider not exporting these during wildcard import (reserve
# that for the types; for idiomatic typing code.)
'get_signature',
'check_fn',
'get_param_names',
'parse_type_line',
'get_type_line',
'split_type_line',
'try_real_annotations',
'try_ann_to_type',
'ann_to_type',
]