Source code for torch.jit._script


This module contains functionality to support the JIT's scripting frontend, notably:
    - torch.jit.script

This is not intended to be imported directly; please use the exposed
functionalities in `torch.jit`.
import collections
import copy
import enum
import functools
import inspect
import pickle
import warnings
from typing import Any, Callable, Dict, List, Set, Tuple, Union

import torch
import torch._jit_internal as _jit_internal
from torch._classes import classes
from torch._jit_internal import _qualified_name
from torch.jit._builtins import _register_builtin
from torch.jit._fuser import _graph_for, _script_method_graph_for

from torch.jit._monkeytype_config import (
from torch.jit._recursive import (
from torch.jit._state import (
from torch.jit.frontend import get_default_args, get_jit_class_def, get_jit_def
from torch.nn import Module
from torch.overrides import (
from torch.package import PackageExporter, PackageImporter
from torch.utils import set_module
from ._serialization import validate_map_location

type_trace_db = JitTypeTraceStore()  # DB to hold all call traces from MonkeyType

torch._C.ScriptMethod.graph_for = _script_method_graph_for  # type: ignore[attr-defined]
torch._C.ScriptFunction.graph_for = _graph_for  # type: ignore[attr-defined]
ScriptFunction = torch._C.ScriptFunction
ScriptFunction.__doc__ = """
Functionally equivalent to a :class:`ScriptModule`, but represents a single
function and does not have any attributes or Parameters.
set_module(ScriptFunction, "torch.jit")

# Throws an error if a jit function is pickled.
# Helps to avoid Python crashes for Python versions 3.9.5 + when protocol 0 or 1 is given as an argument.
def _reduce(cls):
    raise pickle.PickleError("ScriptFunction cannot be pickled")

ScriptFunction.__reduce__ = _reduce  # type: ignore[assignment]

if _enabled:
    Attribute = collections.namedtuple("Attribute", ["value", "type"])

[docs] def Attribute(value, type): # type: ignore[no-redef] return value
Attribute.__doc__ = """ This method is a pass-through function that returns `value`, mostly used to indicate to the TorchScript compiler that the left-hand side expression is a class instance attribute with type of `type`. Note that `torch.jit.Attribute` should only be used in `__init__` method of `jit.ScriptModule` subclasses. Though TorchScript can infer correct type for most Python expressions, there are some cases where type inference can be wrong, including: - Empty containers like `[]` and `{}`, which TorchScript assumes to be container of `Tensor` - Optional types like `Optional[T]` but assigned a valid value of type `T`, TorchScript would assume it is type `T` rather than `Optional[T]` In eager mode, it is simply a pass-through function that returns `value` without other implications. Example: .. testcode:: import torch from typing import Dict class AttributeModule(torch.jit.ScriptModule): def __init__(self): super().__init__() = torch.jit.Attribute(0.1, float) # we should be able to use as a float here assert 0.0 < self.names_ages = torch.jit.Attribute({}, Dict[str, int]) self.names_ages["someone"] = 20 assert isinstance(self.names_ages["someone"], int) m = AttributeModule() # m will contain two attributes # 1. foo of type float # 2. names_ages of type Dict[str, int] .. testcleanup:: del AttributeModule del m Note: it's now preferred to instead use type annotations instead of `torch.jit.Attribute`: .. testcode:: import torch from typing import Dict class AttributeModule(torch.nn.Module): names: Dict[str, int] def __init__(self): super().__init__() self.names = {} m = AttributeModule() .. testcleanup:: del AttributeModule del m Args: value: An initial value to be assigned to attribute. type: A Python type Returns: Returns `value` """ def _get_type_trace_db(): # This is a private API. Use of this for external purposes is discouraged. return type_trace_db # Gets a function from the name of a method on a type def _get_function_from_type(cls, name): return getattr(cls, name, None) # ScriptClasses must be new-style classes because we construct them using their # __new__ method. def _is_new_style_class(cls): if hasattr(cls, "__class__"): return "__dict__" in dir(cls) or hasattr(cls, "__slots__") # These OrderedDictWrapper classes replace the actual OrderedDicts in # module with versions that get/set properties inside of Module. # This allows us to reuse most of nn.Module while still storing the # data in C++. # Each OrderedDict needs to support: # x not in view # x in view # view[name] = ... # view.values() # del view[name] # view.items() # view.keys() # len(view) class OrderedDictWrapper: def __init__(self, _c): self._c = _c def keys(self): return [k for k, v in self.items()] def values(self): return [v for k, v in self.items()] def __len__(self): return len(self.values()) def __delitem__(self, k): raise RuntimeError("cannot delete methods or parameters of a script module") def items(self): return self._c.items() def __setitem__(self, k, v): if k not in self: raise RuntimeError( f"Can't add a new parameter after ScriptModule construction. Tried to add '{k}" ) self._c.setattr(k, v) def __contains__(self, k): return self._c.contains(k) def __getitem__(self, k): if k not in self: raise KeyError(k) return self._c.getattr(k) class OrderedModuleDict(OrderedDictWrapper): def __init__(self, module, python_dict): super().__init__(torch._C.ModuleDict(module)) # contains _both_ script modules and non-script python-only modules # because script modules are subclassed in python and the # C++ Module class will not hold references to them, # to ensure that you always get the same python value here # we store it in the python dict as well self._python_modules = python_dict def items(self): r = self._python_modules.items() return r def __contains__(self, k): return k in self._python_modules def __setitem__(self, k, v): # Cases where sub-module can be re-assigned after ScriptModule construction # 1. If the attr is an module interface type, it's guaranteed that the module is # not inlined in the graph, so it's safe to swap a new ScriptModule in. # 2. if the new value if a ScriptModule with the same JIT type, IR won't change # and it's legit to swap a new module in. # In these two cases we allow swapping a new scripted module and update the # corresponding python module dict to keep sync. # Note: the value to be swapped in has to be ScriptModule instead of nn.Module, # otherwise it's illegal and we throw error. if isinstance(v, ScriptModule): self._c.setattr(k, v) self._python_modules[k] = v else: raise RuntimeError( "Cannot re-assign modules in a ScriptModule with non-scripted " f"module, tried to replace existing module '{k}': {v}" ) def __getitem__(self, k): return self._python_modules[k] # For each user-defined class that subclasses ScriptModule, this meta-class: # (1) finds all the methods annotated with @script_method in a ScriptModule and # removes them from the class attributes # (2) puts a wrapper around the class's __init__ method to recursively compile # all of the script_methods with the module after the original __init__ has # run. This has to occur after the user-defined __init__ so that submodules and # parameters are initialized _before_ the script compiler resolve references to # `self.param` or `self.module`. class ScriptMeta(type): def __init__(cls, name, bases, attrs): # noqa: B902 # Aggregate all the ScriptMethods and constants from superclasses cls._methods: Dict[str, Any] = {} cls._constants_set = set(getattr(cls, "__constants__", ())) for base in reversed(bases): for k, v in getattr(base, "_methods", {}).items(): cls._methods[k] = v base_constants: Set = getattr(base, "_constants_set", set()) cls._constants_set = cls._constants_set.union(base_constants) # find all the script methods of the current class for k, v in sorted(attrs.items()): if isinstance(v, ScriptMethodStub): delattr(cls, k) cls._methods[v.original_method.__name__] = v if getattr(cls, "_disable_script_meta", False): # We leave built-in ScriptModule types alone, since this metaclass # is only for compiling user classes that inherit from # ScriptModule. return super().__init__(name, bases, attrs) original_init = getattr(cls, "__init__", lambda self: None) @functools.wraps(original_init) def init_then_script(self, *args, **kwargs): num_methods = len(cls._methods) original_init(self, *args, **kwargs) added_methods_in_init = len(cls._methods) > num_methods if type(self) == cls: def make_stubs(module): cls = type(module) if hasattr(cls, "_methods"): return [v for k, v in sorted(cls._methods.items())] else: return infer_methods_to_compile(module) self.__dict__[ "_actual_script_module" ] = torch.jit._recursive.create_script_module( self, make_stubs, share_types=not added_methods_in_init ) # Delete the Python attributes that now shadow the ScriptModule # ones, so that __getattr__ and __setattr__ will properly find # the scripted versions. concrete_type = self._actual_script_module._concrete_type for name in concrete_type.get_attributes(): delattr(self, name) for name, _ in concrete_type.get_modules(): delattr(self, name) for name in ("_parameters", "_buffers", "_modules"): delattr(self, name) cls.__init__ = init_then_script # type: ignore[misc] super().__init__(name, bases, attrs) class _CachedForward: def __get__(self, obj, cls): return self.__getattr__("forward") # type: ignore[attr-defined] class ScriptWarning(Warning): pass def script_method(fn): if not _enabled: return fn # NOTE: we need to traverse two frames here because the meta-class frame # for ScriptModule will be present, as opposed to invoking @script on a # a function or invoking define() on a CompilationUnit. # The stack will look like: # # 0. createResolutionCallback() # 1. script_method() # 2. ScriptModule metaclass frame # 3. Surrounding scope # # createResolutionCallback internally adds 1 to get us to the scope of this # function (the calling function). Adding 2 gets us to the proper surrounding scope. _rcb = _jit_internal.createResolutionCallbackFromFrame(frames_up=2) ast = get_jit_def(fn, fn.__name__, self_name="ScriptModule") return ScriptMethodStub(_rcb, ast, fn) class ConstMap: def __init__(self, const_mapping): self.const_mapping = const_mapping def __getattr__(self, attr): return self.const_mapping[attr] def unpackage_script_module( importer: PackageImporter, script_module_id: str ) -> torch.nn.Module: """ Call by ``torch.package.PackageImporter``'s Pickler's ``persistent_load`` function. Performs work of loading and returning a ScriptModule from a ``torch.package`` archive. """ if not isinstance(importer.zip_reader, torch._C.PyTorchFileReader): raise RuntimeError( "Loading ScriptObjects from a PackageImporter created from a " "directory is not supported. Use a package archive file instead." ) cu = torch._C.CompilationUnit() cpp_module = torch._C._import_ir_module_from_package( cu, importer.zip_reader, importer.storage_context, validate_map_location(importer.last_map_location), script_module_id, ) return wrap_cpp_module(cpp_module) if _enabled: _magic_methods = [ "__iter__", "__len__", "__neg__", "__mul__", "__contains__", "__add__", "__sub__", "__pow__", "__truediv__", "__mod__", "__ne__", "__eq__", "__lt__", "__gt__", "__le__", "__ge__", "__and__", "__or__", "__xor__", "__getitem__", "__setitem__", "__call__", "__int__", "__float__", "__bool__", "__str__", "__enter__", "__exit__", ] class RecursiveScriptClass: """Wrapper for a TorchScript class instance for use in Python. An analogue of RecursiveScriptModule for regular objects that are not modules. This class is a wrapper around a torch._C.ScriptObject that represents an instance of a TorchScript class and allows it to be used in Python. Attributes: _c [torch._C.ScriptObject]: The C++ object to which attribute lookups and method calls are forwarded. _props [Dict[str, property]]: A dictionary of properties fetched from self._c and exposed on this wrppaer. """ def __init__(self, cpp_class): super().__init__() self.__dict__["_initializing"] = True self._c = cpp_class # Add wrapped object's properties to this class instance. self._props = { property(prop.getter, prop.setter) for prop in self._c._properties() } self.__dict__["_initializing"] = False def __getattr__(self, attr): if self.__dict__.get("_initializing"): return super().__getattr__(attr) # type: ignore[misc] if attr in self._props: return self._props[attr].fget() # type: ignore[call-arg, misc] return getattr(self._c, attr) def __setattr__(self, attr, value): if self.__dict__.get("_initializing"): return super().__setattr__(attr, value) if attr in self._props: return self._props[attr].fset(value) # type: ignore[call-arg, misc] setattr(self._c, attr, value) # Delegate calls to magic methods like __len__ to the C++ module backing the # RecursiveScriptClass. def forward_magic_method(self, method_name, *args, **kwargs): if not self._c._has_method(method_name): raise TypeError() self_method = self.__getattr__(method_name) return self_method(*args, **kwargs) def __getstate__(self): raise pickle.PickleError("ScriptClasses cannot be pickled") def __iadd__(self, other): if self._c._has_method("__iadd__"): return self.forward_magic_method("__iadd__", other) else: return self.forward_magic_method("__add__", other) for method_name in _magic_methods: def method_template(self, *args, **kwargs): return self.forward_magic_method(method_name, *args, **kwargs) setattr(RecursiveScriptClass, method_name, method_template) # this is a Python 'non-data descriptor' that causes the first access # to ScriptModule's forward to look up the forward method and stash # it in the objects dict. Due to the standard rules for attribute lookup, # subsequent lookups will just directly return the previously looked up method. # This is necessary because nn.Module defines forward as a method. If we # did nothing, __getattr__ would not be called. Instead we'd get nn.Module.forward # which always throws an exception. class ScriptModule(Module, metaclass=ScriptMeta): r"""Wrapper for C++ torch::jit::Module with methods, attributes, and parameters. A wrapper around C++ ``torch::jit::Module``. ``ScriptModule``\s contain methods, attributes, parameters, and constants. These can be accessed the same way as on a normal ``nn.Module``. """ __jit_unused_properties__ = [ "code", "code_with_constants", "graph", "inlined_graph", "original_name", ] def __init__(self): super().__init__() forward: Callable[..., Any] = _CachedForward() # type: ignore[assignment] def __getattr__(self, attr): if "_actual_script_module" not in self.__dict__: return super().__getattr__(attr) return getattr(self._actual_script_module, attr) def __setattr__(self, attr, value): if "_actual_script_module" not in self.__dict__: # Unwrap torch.jit.Attribute into a regular setattr + record # the provided type in __annotations__. # # This ensures that if we use the attr again in `__init__`, it # will look like the actual value, not an instance of Attribute. if isinstance(value, Attribute): # NB: Ensure that we set __annotations__ on the specific # class in question, and not on a superclass (which would # be wrong wrong wrong!). # See also if "__annotations__" not in self.__class__.__dict__: self.__class__.__annotations__ = {} self.__annotations__[attr] = value.type value = value.value return super().__setattr__(attr, value) setattr(self._actual_script_module, attr, value) def define(self, src): if "_actual_script_module" in self.__dict__: # If we have completed initialization, just defer to the # backing RecursiveScriptModule to eagerly compile the provided # source. return self._actual_script_module.define(src) # Otherwise, we are still in the object's __init__. # In that case, add `src` as a stub to be compiled. # # We use frames_up=1 to get to the proper surrounding scope. The stack # will look like: # 0. createResolutionCallback # 1. define() # 2. surrounding scope. # # createResolutionCallback internally adds 1 to get us to our frame, then # we add 1 to get to the proper surrounding scope. rcb = _jit_internal.createResolutionCallbackFromFrame(frames_up=1) ast = torch._C._parse_source_def(src) self._methods[] = ScriptMethodStub(rcb, ast, None) def _replicate_for_data_parallel(self): return self._actual_script_module._replicate_for_data_parallel() def __reduce_package__(self, exporter: PackageExporter): """Save a ScriptModule inside of a ``torch.package`` archive. Called by ``torch.package.PackageExporter``'s Pickler's ``persistent_id`` when saving TorchScript objects. Performs act of saving a ScriptModule inside of a ``torch.package`` archive. Returns method to load the ScriptModule from a ``torch.package.PackageImporter``'s Pickler's ``persistent_load`` function. """ script_module_id = exporter.get_unique_id() exporter.script_module_serializer.serialize(self._c, int(script_module_id)) return (unpackage_script_module, (script_module_id,)) class RecursiveScriptModule(ScriptModule): # XXX: RecursiveScriptModule inherits from ScriptModule for the sole # reason that it retains the existing isinstance(ScriptModule) # behavior. r"""Retain the existing isinstance(ScriptModule) behavior. The core data structure in TorchScript is the ``ScriptModule``. It is an analogue of torch's ``nn.Module`` and represents an entire model as a tree of submodules. Like normal modules, each individual module in a ``ScriptModule`` can have submodules, parameters, and methods. In ``nn.Module``\s methods are implemented as Python functions, but in ``ScriptModule``\s methods are implemented as TorchScript functions, a statically-typed subset of Python that contains all of PyTorch's built-in Tensor operations. This difference allows your ``ScriptModule``\s code to run without the need for a Python interpreter. ``ScriptModule``\s should not be created manually, instead use either :func:`tracing <torch.jit.trace>` or :func:`scripting <torch.jit.script>`. Tracing and scripting can be applied incrementally and :ref:`composed as necessary <Types>`. * Tracing records the tensor operations as executed with a set of example inputs and uses these operations to construct a computation graph. You can use the full dynamic behavior of Python with tracing, but values other than Tensors and control flow aren't captured in the graph. * Scripting inspects the Python code of the model and compiles it to TorchScript. Scripting allows the use of many `types`_ of values and supports dynamic control flow. Many, but not all features of Python are supported by the compiler, so changes to the source code may be necessary. """ _disable_script_meta = True def __init__(self, cpp_module): self.__dict__["_initializing"] = True self._c = cpp_module super().__init__() # Delete the 'training' attribute set up by `Module.__init__`. It # will get set on the underlying cpp module, so we delete it here # to avoid this version shadowing the cpp module version. delattr(self, "training") @staticmethod def _construct(cpp_module, init_fn): """ Construct a RecursiveScriptModule that's ready for use. PyTorch code should use this to construct a RecursiveScriptModule instead of instead of calling `__init__` directly, as it makes sure the object is properly finalized (and in the future, we may take control of how the RecursiveScriptModule instance is created). Args: cpp_module: The C++ Module that will hold the actual state of this RecursiveScriptModule instance. init_fn: Lambda that initializes the RecursiveScriptModule passed to it. """ script_module = RecursiveScriptModule(cpp_module) init_fn(script_module) # Finalize the ScriptModule: replace the nn.Module state with our # custom implementations and flip the _initializing bit. RecursiveScriptModule._finalize_scriptmodule(script_module) return script_module @staticmethod def _finalize_scriptmodule(script_module): script_module._parameters = OrderedDictWrapper( torch._C.ParameterDict(script_module._c) ) script_module._buffers = OrderedDictWrapper( torch._C.BufferDict(script_module._c) ) script_module._modules = OrderedModuleDict( script_module._c, script_module._modules ) script_module._initializing = False def _reconstruct(self, cpp_module): """ Re-construct an instance of RecursiveScriptModule using an instance of a C++ module. Args: cpp_module: The C++ module that this RecursiveScriptModule will be rebuilt around. """ self.__init__(cpp_module) # type: ignore[misc] # Copy the concrete type from the C++ module to this ScriptModule. self._concrete_type = torch._C.ConcreteModuleType.from_jit_type( self._c._type() ) # Copy submodules from the C++ module to this ScriptModule. modules = {} for name, cpp_module in torch._C.ModuleDict(self._c).items(): modules[name] = wrap_cpp_module(cpp_module) self._modules = OrderedModuleDict(self._c, modules) # type: ignore[assignment] # Copy parameters and buffers. self._parameters = OrderedDictWrapper(torch._C.ParameterDict(self._c)) # type: ignore[assignment] self._buffers = OrderedDictWrapper(torch._C.BufferDict(self._c)) # type: ignore[assignment] # Get rid of the functions from the old C++ module. self.__dict__ = { k: v for k, v in self.__dict__.items() if not isinstance(v, torch._C.ScriptMethod) } self.__dict__["_initializing"] = False @property def graph(self): r"""Return a string representation of the internal graph for the ``forward`` method. See :ref:`interpreting-graphs` for details. """ return self._c._get_method("forward").graph @property def inlined_graph(self): r""" Return a string representation of the internal graph for the ``forward`` method. This graph will be preprocessed to inline all function and method calls. See :ref:`interpreting-graphs` for details. """ return self.forward.inlined_graph # type: ignore[attr-defined] @property def code(self): r""" Return a pretty-printed representation (as valid Python syntax) of the internal graph for the ``forward`` method. See :ref:`inspecting-code` for details. """ return self.forward.code # type: ignore[attr-defined] @property def code_with_constants(self): r"""Return a tuple. Returns a tuple of: [0] a pretty-printed representation (as valid Python syntax) of the internal graph for the ``forward`` method. See `code`. [1] a ConstMap following the CONSTANT.cN format of the output in [0]. The indices in the [0] output are keys to the underlying constant's values. See :ref:`inspecting-code` for details. """ r = self.forward.code_with_constants # type: ignore[attr-defined] return (r[0], ConstMap(r[1])) def save(self, f, **kwargs): r"""Save with a file-like object. save(f, _extra_files={}) See :func:` <>` which accepts a file-like object. This function,, converts the object to a string, treating it as a path. DO NOT confuse these two functions when it comes to the 'f' parameter functionality. """ return, **kwargs) def _save_for_lite_interpreter(self, *args, **kwargs): r"""Add (or update) the bytecode session to the script model. _save_for_lite_interpreter(f) The updated model is used in lite interpreter for mobile applications. Args: f: a string containing a file name. _extra_files: Map from filename to contents which will be stored as part of 'f'. """ return self._c._save_for_mobile(*args, **kwargs) def _save_to_buffer_for_lite_interpreter(self, *args, **kwargs): return self._c._save_to_buffer_for_mobile(*args, **kwargs) def save_to_buffer(self, *args, **kwargs): return self._c.save_to_buffer(*args, **kwargs) def get_debug_state(self, *args, **kwargs): return self._c.get_debug_state() def extra_repr(self): return f"original_name={self.original_name}" def graph_for(self, *args, **kwargs): return self.forward.graph_for(self, *args, **kwargs) # type: ignore[attr-defined] @property def original_name(self): if type(self) == str(self._c._type().name()): return "" return str(self._c._type().name()) def define(self, src): # We use frames_up=1 to get to the proper surrounding scope. The stack # will look like: # 0. createResolutionCallback # 1. define() # 2. surrounding scope. # # createResolutionCallback internally adds 1 to get us to our frame, then # we add 1 to get to the proper surrounding scope. rcb = _jit_internal.createResolutionCallbackFromFrame(frames_up=1) self._c._define(self._concrete_type, src, rcb) def __getattr__(self, attr): if "_initializing" not in self.__dict__: raise RuntimeError( "ScriptModule has not been initialized, did you forget to call super's init?" ) if self._initializing: return super().__getattr__(attr) # _modules check is before hasattr since modules are included as attributes in _c, # but we want to get the python wrapper from _modules instead of the raw _c object. if attr in self._modules: return self._modules[attr] elif self._c.hasattr(attr): return self._c.getattr(attr) elif self._c._has_method(attr): script_method = self._c._get_method(attr) # cache method so future calls do not go through __getattr__ # to improve invocation performance self.__dict__[attr] = script_method return script_method return super().__getattr__(attr) def __setattr__(self, attr, value): if self._initializing: return super().__setattr__(attr, value) if attr in self._modules: self._modules[attr] = value elif self._c.hasattr(attr): self._c.setattr(attr, value) elif ( hasattr(self, "_concrete_type") and attr in self._concrete_type.get_constants().keys() ): # TODO: we don't have _concrete_type set after load(), and in general we lose constant information. # We should encode constants as class type attributes (or something) so it persists across save/load. raise AttributeError( f"Cannot mutate TorchScript constant value: '{attr}'. Value: '{value}'" ) else: # We allow setting Python attributes on the ScriptModule, for # when people want to stash some convenience info on it. # TODO: it's possible that the following is confusing: # s = torch.jit.script(...) # s.python_attr = ... # <--- this doesn't have `python_attr` # It's fairly trivial to save enough info to warn in this case. return super().__setattr__(attr, value) def __copy__(self): return torch.jit._recursive.wrap_cpp_module(copy.copy(self._c)) def __deepcopy__(self, memo): return torch.jit._recursive.wrap_cpp_module(copy.deepcopy(self._c, memo)) # Python magic methods do method lookups on an object's class type, instead of looking up # the method defines on the class instance. In order to continue to expose the magic methods # of builtin-containers (ModuleList, Sequential, ModuleDict) to Python, we # define magic methods here as a shim to the correct attribute. def forward_magic_method(self, method_name, *args, **kwargs): self_method = getattr(self, method_name) if getattr(self_method, "__func__", None) == getattr( RecursiveScriptModule, method_name ): raise NotImplementedError() return self_method(*args, **kwargs) def __iter__(self): return self.forward_magic_method("__iter__") def __getitem__(self, idx): return self.forward_magic_method("__getitem__", idx) def __len__(self): return self.forward_magic_method("__len__") def __contains__(self, key): return self.forward_magic_method("__contains__", key) # dir is defined by the base nn.Module, so instead of throwing if # it is not overridden, we call into the nn.Module __dir__ method def __dir__(self): self_method = self.__dir__ if ( self_method.__func__ # type: ignore[attr-defined] == _get_function_from_type(RecursiveScriptModule, "__dir__") ): return super().__dir__() return self_method() # to resolve bool(value), Python looks if __bool__ is defined then __iter__ # is defined then returns true for classes. Since __iter__() on this # class throws if it isn't overridden, we define __bool__ to preserve default behavior def __bool__(self): self_method = self.__bool__ if ( self_method.__func__ # type: ignore[attr-defined] == _get_function_from_type(RecursiveScriptModule, "__bool__") ): return True return self_method() def _replicate_for_data_parallel(self): # we have to initialize ScriptModule properly so that # it works with pybind11 def init_fn(script_module): # Don't do anything here, we'll initialize the ScriptModule below return return RecursiveScriptModule._construct( self._c._replicate_for_data_parallel(), init_fn ) # Need to copy all RecursiveScriptModule methods to ScriptModule. # # This is because `super().foo()` does not use # `__getattr__` to look up `foo`. So we need to make each method available on # the ScriptModule manually. for name, item in RecursiveScriptModule.__dict__.items(): if not callable(item) and not isinstance(item, property): continue if name.startswith("__") or hasattr(ScriptModule, name): continue # We can copy over the implementation wholesale because besides the # `super()` thing above, ScriptModule behaves exactly like # RecursiveScriptModule setattr(ScriptModule, name, item) def _get_methods(cls): import inspect # In Python 3 unbound methods are functions, but in Python 2 they are methods return inspect.getmembers( cls, predicate=lambda x: inspect.isfunction(x) or inspect.ismethod(x) ) _compiled_methods_allowlist = { "forward", "register_buffer", "register_parameter", "register_module", "add_module", "_apply", "apply", "cuda", "cpu", "to", "type", "float", "double", "half", "state_dict", "_save_to_state_dict", "load_state_dict", "_load_from_state_dict", "_named_members", "parameters", "named_parameters", "buffers", "named_buffers", "children", "named_children", "modules", "named_modules", "zero_grad", "share_memory", "_get_name", "extra_repr", "_slow_forward", "_tracing_name", "eval", "train", "get_extra_state", "set_extra_state", } def _make_fail(name): def fail(self, *args, **kwargs): raise RuntimeError(name + " is not supported on ScriptModules") return fail for name, method in _get_methods(torch.nn.Module): if name.startswith("__") or name.endswith("_call_impl"): continue if ( name not in RecursiveScriptModule.__dict__ and name not in _compiled_methods_allowlist ): setattr(RecursiveScriptModule, method.__name__, _make_fail(name)) else: # TODO MAKE SURE THAT DISABLING WORKS class RecursiveScriptClass: # type: ignore[no-redef] pass
[docs] class ScriptModule(torch.nn.Module): # type: ignore[no-redef] def __init__(self, arg=None): super().__init__()
class RecursiveScriptModule(ScriptModule): # type: ignore[no-redef] def __init__(self, arg=None): super().__init__() def call_prepare_scriptable_func_impl(obj, memo): if not isinstance(obj, torch.nn.Module): return obj obj_id = id(obj) # If obj_id is in memo, obj has already been prepared or is being # prepared in another call up the stack. if obj_id in memo: return memo[id(obj)] obj = obj.__prepare_scriptable__() if hasattr(obj, "__prepare_scriptable__") else obj # type: ignore[operator] # Record obj in memo to avoid infinite recursion in the case of cycles in the module # hierarchy when recursing below. memo[obj_id] = obj new_obj_dict = {} for name, sub_module in obj.__dict__.items(): if name == "_modules": for k, v in sub_module.items(): sub_module[k] = call_prepare_scriptable_func_impl(v, memo) new_obj_dict[name] = sub_module elif isinstance(sub_module, torch.nn.Module) and not isinstance( sub_module, ScriptModule ): new_obj_dict[name] = call_prepare_scriptable_func_impl(sub_module, memo) else: new_obj_dict[name] = sub_module for k, v in new_obj_dict.items(): obj.__dict__[name] = v return obj def call_prepare_scriptable_func(obj): memo: Dict[int, torch.nn.Module] = {} return call_prepare_scriptable_func_impl(obj, memo) def create_script_dict(obj): """ Create a ``torch._C.ScriptDict`` instance with the data from ``obj``. Args: obj (dict): The Python dictionary that is used to initialize the ``ScriptDict`` returned by this function. Returns: An instance of ``torch._C.ScriptDict`` that has the same data as ``obj`` and can be passed between Python and TorchScript with reference semantics and zero copy overhead. """ return torch._C.ScriptDict(obj) # type: ignore[attr-defined] def create_script_list(obj, type_hint=None): """ Create a ``torch._C.ScriptList`` instance with the data from ``obj``. Args: obj (dict): The Python list that is used to initialize the ``ScriptList`` returned by this function. Returns: An instance of ``torch._C.ScriptList`` that has the same data as ``obj`` and can be passed between Python and TorchScript with reference semantics and zero copy overhead. """ return torch._C.ScriptList(obj) # type: ignore[attr-defined]
[docs]def script( obj, optimize=None, _frames_up=0, _rcb=None, example_inputs: Union[List[Tuple], Dict[Callable, List[Tuple]], None] = None, ): r"""Script the function. Scripting a function or ``nn.Module`` will inspect the source code, compile it as TorchScript code using the TorchScript compiler, and return a :class:`ScriptModule` or :class:`ScriptFunction`. TorchScript itself is a subset of the Python language, so not all features in Python work, but we provide enough functionality to compute on tensors and do control-dependent operations. For a complete guide, see the :ref:`language-reference`. Scripting a dictionary or list copies the data inside it into a TorchScript instance than can be subsequently passed by reference between Python and TorchScript with zero copy overhead. ``torch.jit.script`` can be used as a function for modules, functions, dictionaries and lists and as a decorator ``@torch.jit.script`` for :ref:`torchscript-classes` and functions. Args: obj (Callable, class, or nn.Module): The ``nn.Module``, function, class type, dictionary, or list to compile. example_inputs (Union[List[Tuple], Dict[Callable, List[Tuple]], None]): Provide example inputs to annotate the arguments for a function or ``nn.Module``. Returns: If ``obj`` is ``nn.Module``, ``script`` returns a :class:`ScriptModule` object. The returned :class:`ScriptModule` will have the same set of sub-modules and parameters as the original ``nn.Module``. If ``obj`` is a standalone function, a :class:`ScriptFunction` will be returned. If ``obj`` is a ``dict``, then ``script`` returns an instance of `torch._C.ScriptDict`. If ``obj`` is a ``list``, then ``script`` returns an instance of `torch._C.ScriptList`. **Scripting a function** The ``@torch.jit.script`` decorator will construct a :class:`ScriptFunction` by compiling the body of the function. Example (scripting a function): .. testcode:: import torch @torch.jit.script def foo(x, y): if x.max() > y.max(): r = x else: r = y return r print(type(foo)) # torch.jit.ScriptFunction # See the compiled graph as Python code print(foo.code) # Call the function using the TorchScript interpreter foo(torch.ones(2, 2), torch.ones(2, 2)) .. testoutput:: :hide: ... ****Scripting a function using example_inputs** Example inputs can be used to annotate a function arguments. Example (annotating a function before scripting): .. testcode:: import torch def test_sum(a, b): return a + b # Annotate the arguments to be int scripted_fn = torch.jit.script(test_sum, example_inputs=[(3, 4)]) print(type(scripted_fn)) # torch.jit.ScriptFunction # See the compiled graph as Python code print(scripted_fn.code) # Call the function using the TorchScript interpreter scripted_fn(20, 100) .. testoutput:: :hide: ... **Scripting an nn.Module** Scripting an ``nn.Module`` by default will compile the ``forward`` method and recursively compile any methods, submodules, and functions called by ``forward``. If a ``nn.Module`` only uses features supported in TorchScript, no changes to the original module code should be necessary. ``script`` will construct :class:`ScriptModule` that has copies of the attributes, parameters, and methods of the original module. Example (scripting a simple module with a Parameter): .. testcode:: import torch class MyModule(torch.nn.Module): def __init__(self, N, M): super().__init__() # This parameter will be copied to the new ScriptModule self.weight = torch.nn.Parameter(torch.rand(N, M)) # When this submodule is used, it will be compiled self.linear = torch.nn.Linear(N, M) def forward(self, input): output = # This calls the `forward` method of the `nn.Linear` module, which will # cause the `self.linear` submodule to be compiled to a `ScriptModule` here output = self.linear(output) return output scripted_module = torch.jit.script(MyModule(2, 3)) Example (scripting a module with traced submodules): .. testcode:: import torch import torch.nn as nn import torch.nn.functional as F class MyModule(nn.Module): def __init__(self): super().__init__() # torch.jit.trace produces a ScriptModule's conv1 and conv2 self.conv1 = torch.jit.trace(nn.Conv2d(1, 20, 5), torch.rand(1, 1, 16, 16)) self.conv2 = torch.jit.trace(nn.Conv2d(20, 20, 5), torch.rand(1, 20, 16, 16)) def forward(self, input): input = F.relu(self.conv1(input)) input = F.relu(self.conv2(input)) return input scripted_module = torch.jit.script(MyModule()) To compile a method other than ``forward`` (and recursively compile anything it calls), add the :func:`@torch.jit.export <torch.jit.export>` decorator to the method. To opt out of compilation use :func:`@torch.jit.ignore <torch.jit.ignore>` or :func:`@torch.jit.unused <torch.jit.unused>`. Example (an exported and ignored method in a module):: import torch import torch.nn as nn class MyModule(nn.Module): def __init__(self): super().__init__() @torch.jit.export def some_entry_point(self, input): return input + 10 @torch.jit.ignore def python_only_fn(self, input): # This function won't be compiled, so any # Python APIs can be used import pdb pdb.set_trace() def forward(self, input): if self.python_only_fn(input) return input * 99 scripted_module = torch.jit.script(MyModule()) print(scripted_module.some_entry_point(torch.randn(2, 2))) print(scripted_module(torch.randn(2, 2))) Example ( Annotating forward of nn.Module using example_inputs):: import torch import torch.nn as nn from typing import NamedTuple class MyModule(NamedTuple): result: List[int] class TestNNModule(torch.nn.Module): def forward(self, a) -> MyModule: result = MyModule(result=a) return result pdt_model = TestNNModule() # Runs the pdt_model in eager model with the inputs provided and annotates the arguments of forward scripted_model = torch.jit.script(pdt_model, example_inputs={pdt_model: [([10, 20, ], ), ], }) # Run the scripted_model with actual inputs print(scripted_model([20])) """ global type_trace_db if not _enabled: return obj if optimize is not None: warnings.warn( "`optimize` is deprecated and has no effect. Use `with torch.jit.optimized_execution() instead" ) # No-op for modules, functions, class instances that are already scripted if isinstance(obj, RecursiveScriptClass): return obj if isinstance(obj, ScriptModule): return obj if isinstance(obj, ScriptFunction): return obj if example_inputs: # If MonkeyType is installed, enable profile directed type annotation # Check if example_inputs are defined and generate call traces # for the method by running eager mode version of the method with # the provide example inputs. This logs all the traces in type_trace_db type_trace_db = JitTypeTraceStore() if monkeytype_trace: monkeytype_config = JitTypeTraceConfig(type_trace_db) with monkeytype_trace(monkeytype_config): if isinstance(example_inputs, Dict): # If the obj is an nn.Module or a class, then each method is # executed with the arguments provided in the example inputs. # example inputs here will be of type Dict(class.method, (arguments)) # This is used to infer type annotations for those methods # which are not called directly under the hood of monkeytype. for module, example_input in example_inputs.items(): for example in example_input: module(*example) elif isinstance(example_inputs, List): for examples in example_inputs: obj(*examples) else: raise ValueError( "Error: Unable to infer types. Please format the inputs to type `List[Tuple]`" " or `Dict[Callable, List[Tuple]]` to be run with MonkeyType." ) else: warnings.warn( "Warning: monkeytype is not installed. Please install " "to enable Profile-Directed Typing in TorchScript. Refer to " " to install MonkeyType. " ) if isinstance(obj, torch.nn.Module): obj = call_prepare_scriptable_func(obj) return torch.jit._recursive.create_script_module( obj, torch.jit._recursive.infer_methods_to_compile ) else: obj = obj.__prepare_scriptable__() if hasattr(obj, "__prepare_scriptable__") else obj # type: ignore[operator] if isinstance(obj, dict): return create_script_dict(obj) if isinstance(obj, list): return create_script_list(obj) if inspect.isclass(obj): qualified_name = _qualified_name(obj) # If this type is a `nn.Module` subclass, they probably meant to pass # an instance instead of a Module if issubclass(obj, torch.nn.Module): raise RuntimeError( f"Type '{obj}' cannot be compiled since it inherits from nn.Module, pass an instance instead" ) # Enums are automatically usable in TorchScript, explicitly scripting # is not necessary, but not harmful either. if issubclass(obj, enum.Enum): return obj if not _is_new_style_class(obj): raise RuntimeError( "TorchScript classes must be new-style classes. " "Please inherit from 'object'." ) if len(obj.mro()) > 2: raise RuntimeError( "TorchScript classes does not support inheritance yet. " "Please directly inherit from 'object'." ) if _rcb is None: _rcb = _jit_internal.createResolutionCallbackFromFrame(_frames_up + 1) _compile_and_register_class(obj, _rcb, qualified_name) return obj elif inspect.isfunction(obj) or inspect.ismethod(obj): qualified_name = _qualified_name(obj) # this is a decorated fn, and we need to the underlying fn and its rcb if hasattr(obj, "__script_if_tracing_wrapper"): obj = obj.__original_fn # type: ignore[union-attr] _rcb = _jit_internal.createResolutionCallbackFromClosure(obj) # some functions are explicitly marked as not supported in script mode if hasattr(obj, "__script_unsupported"): raise RuntimeError("TorchScript error: " + obj.__script_unsupported) _check_directly_compile_overloaded(obj) maybe_already_compiled_fn = _try_get_jit_cached_function(obj) if maybe_already_compiled_fn: return maybe_already_compiled_fn ast = get_jit_def(obj, obj.__name__) if _rcb is None: _rcb = _jit_internal.createResolutionCallbackFromClosure(obj) fn = torch._C._jit_script_compile( qualified_name, ast, _rcb, get_default_args(obj) ) # Forward docstrings fn.__doc__ = obj.__doc__ # Allow torch.compile() to inline fn._torchdynamo_inline = obj # type: ignore[attr-defined] _set_jit_function_cache(obj, fn) return fn else: return torch.jit._recursive.create_script_class(obj)
# overloads are registered in _jit_internal and compiled here so that _overload # can be used in nn/ without an import cycle def _check_overload_defaults(impl_defaults, overload_defaults, loc): for name, overload_value in overload_defaults.items(): if name not in impl_defaults or impl_defaults[name] != overload_value: raise torch.jit.frontend.FrontendError( loc, "Default parameters on overloads do not affect the runtime so they " "must equal to the default parameter on the implementation function. Found on " f"parameter {name}", ) def _compile_function_with_overload(overload_fn, qual_name, impl_fn): overload_decl = get_jit_def(overload_fn, overload_fn.__name__).decl() overload_signature = torch.jit.annotations.get_signature( overload_fn, None, None, inspect.ismethod(overload_fn) ) impl_ast = get_jit_def(impl_fn, impl_fn.__name__) overload_defaults = get_default_args(overload_fn) implementation_defaults = get_default_args(impl_fn) _rcb = _jit_internal.createResolutionCallbackFromClosure(impl_fn) _check_overload_defaults( implementation_defaults, overload_defaults, overload_decl.range() ) fn = torch._C._jit_script_compile_overload( qual_name, overload_decl, impl_ast, _rcb, implementation_defaults, overload_signature, ) return fn def _get_overloads(obj): # check for cached compiled fns existing_compiled_fns = _try_get_jit_cached_overloads(obj) qual_name = _qualified_name(obj) uncompiled_overloads = _jit_internal._get_fn_overloads(qual_name) if uncompiled_overloads is None: return existing_compiled_fns if obj in uncompiled_overloads: raise RuntimeError( _jit_internal.get_overload_no_implementation_error_message("function", obj) ) compiled_fns = [] for overload_fn in uncompiled_overloads: compiled_fns.append( _compile_function_with_overload(overload_fn, qual_name, obj) ) if existing_compiled_fns: compiled_fns = existing_compiled_fns + compiled_fns # cache compilation, remove information stored to do compilation _set_jit_overload_cache(obj, compiled_fns) _jit_internal._clear_fn_overloads(qual_name) return compiled_fns def _check_directly_compile_overloaded(obj): qual_name = _qualified_name(obj) if _jit_internal._get_fn_overloads(qual_name) or _try_get_jit_cached_overloads(obj): raise RuntimeError( f"Function {qual_name} cannot be directly compiled because it" " is overloaded. It must be used in a context of a function" " where its inputs can determine which overload to call." )
[docs]def interface(obj): r"""Decorate to annotate classes or modules of different types. This decorator can be used to define an interface that can be used to annotate classes or modules of different types. This can be used for to annotate a submodule or attribute class that could have different types that implement the same interface, or which could be swapped at runtime; or to store a list of modules or classes of varying types. It is sometimes used to implement "Callables" - functions or modules that implement an interface but whose implementations differ and which can be swapped out. Example: .. testcode:: import torch from typing import List @torch.jit.interface class InterfaceType: def run(self, x: torch.Tensor) -> torch.Tensor: pass # implements InterfaceType @torch.jit.script class Impl1: def run(self, x: torch.Tensor) -> torch.Tensor: return x.relu() class Impl2(torch.nn.Module): def __init__(self): super().__init__() self.val = torch.rand(()) @torch.jit.export def run(self, x: torch.Tensor) -> torch.Tensor: return x + self.val def user_fn(impls: List[InterfaceType], idx: int, val: torch.Tensor) -> torch.Tensor: return impls[idx].run(val) user_fn_jit = torch.jit.script(user_fn) impls = [Impl1(), torch.jit.script(Impl2())] val = torch.rand(4, 4) user_fn_jit(impls, 0, val) user_fn_jit(impls, 1, val) """ if not inspect.isclass(obj): raise RuntimeError("interface must be applied to a class") if not _is_new_style_class(obj): raise RuntimeError("TorchScript interfaces must inherit from 'object'") # Expected MRO is: # User module # torch.nn.modules.module.Module # object is_module_interface = issubclass(obj, torch.nn.Module) and len(obj.mro()) == 3 if not is_module_interface and len(obj.mro()) > 2: raise RuntimeError( "TorchScript interface does not support inheritance yet. " "Please directly inherit from 'object' or 'nn.Module'." ) qualified_name = _qualified_name(obj) rcb = _jit_internal.createResolutionCallbackFromFrame(1) # if this type is a `nn.Module` subclass, generate a module interface type # instead of a class interface type; a module interface type only compiles # the user provided methods as part of the interface ast = get_jit_class_def(obj, obj.__name__) mangled_classname = torch._C._jit_script_interface_compile( qualified_name, ast, rcb, is_module_interface ) obj.__torch_script_interface__ = mangled_classname return obj
def _recursive_compile_class(obj, loc): _qual_name = _qualified_name(obj) # We're starting a new compilation, so update the error call stack in # case it fails error_stack = torch._C.CallStack(_qual_name, loc) rcb = _jit_internal.createResolutionCallbackForClassMethods(obj) return _compile_and_register_class(obj, rcb, _qual_name) CompilationUnit = torch._C.CompilationUnit set_module(CompilationUnit, "torch.jit") def pad(s: str, padding: int, offset: int = 0, char: str = " "): if padding >= len(s): padding -= len(s) return "".join([char for _ in range(padding + offset)]) + s class _ScriptProfileColumn: def __init__(self, header: str, alignment: int = 4, offset: int = 0): self.header = header self.alignment = alignment self.offset = offset self.rows: Dict[int, Any] = {} def add_row(self, lineno: int, value: Any): self.rows[lineno] = value def materialize(self): max_length = len(self.header) rows: List[Tuple[int, str]] = [] for key, value in self.rows.items(): cell = str(value) rows.append((key, cell)) max_length = max(len(cell), max_length) if self.alignment > 0: padding = max_length + self.alignment padding -= padding % self.alignment else: padding = 0 rows = [(key, pad(cell, padding, self.offset)) for key, cell in rows] return pad(self.header, padding, self.offset), rows class _ScriptProfileTable: def __init__(self, cols: List[_ScriptProfileColumn], source_range: List[int]): self.cols = cols self.source_range = source_range def dump_string(self): outputs: List[str] = [] cells: List[Tuple[str, Dict[int, str]]] = [] header_buffer = "" for col in self.cols: header, rows = col.materialize() header_buffer += header cells.append((header, dict(rows))) outputs.append(header_buffer) outputs.append(pad("", len(header_buffer), 0, "=")) for line in self.source_range: row_buffer = "" for header, rows in cells: cell = rows.get(line) if cell is None: row_buffer += pad("", len(header)) else: row_buffer += cell outputs.append(row_buffer) return "\n".join(outputs) class _ScriptProfile: def __init__(self): self.profile = classes.profiling._ScriptProfile() def enable(self): self.profile.enable() def disable(self): self.profile.disable() def dump_string(self) -> str: outputs: List[str] = [] for source_stats in self.profile._dump_stats(): source_ref = source_stats.source() source_lines = source_ref.text().splitlines() dedent = min([len(line) - len(line.lstrip(" ")) for line in source_lines]) source_lines = [line[dedent:] for line in source_lines] start_line = source_ref.starting_lineno() end_line = start_line + len(source_lines) source_range = range(start_line, end_line) lineno = _ScriptProfileColumn("Line #") hits = _ScriptProfileColumn("Hits") time_ns = _ScriptProfileColumn("Time (ns)") line_contents = _ScriptProfileColumn("Line Contents", 0, 1) stats = source_stats.line_map() for line in source_range: lineno.add_row(line, line) line_contents.add_row(line, source_lines[line - start_line]) stat = stats.get(line) if stat is not None: hits.add_row(line, stat.count()) time_ns.add_row(line, stat.duration_ns()) table = _ScriptProfileTable( [lineno, hits, time_ns, line_contents], list(source_range) ) outputs.append(table.dump_string()) return "\n\n".join(outputs) def dump(self): print(self.dump_string()) def _unwrap_optional(x): assert x is not None, "Unwrapping null optional" return x _register_builtin(_unwrap_optional, "aten::_unwrap_optional") _register_builtin(_jit_internal.is_scripting, "aten::is_scripting") _register_builtin(has_torch_function, "aten::has_torch_function") _register_builtin(has_torch_function_unary, "aten::has_torch_function") _register_builtin(has_torch_function_variadic, "aten::has_torch_function")


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