torch/_export/__init__.py

import copy
import dataclasses
import functools
import io
import json
import pathlib
import re
import sys

import types
import warnings
import weakref
import zipfile
from collections import OrderedDict
from contextlib import contextmanager

from typing import Any, Callable, Dict, List, Optional, Tuple, Union
from unittest.mock import patch

import sympy

import torch
import torch._dynamo
import torch.fx
import torch.fx._pytree as fx_pytree

import torch.utils._pytree as pytree
from torch._decomp import core_aten_decompositions, get_decompositions
from torch._dispatch.python import enable_python_dispatcher
from torch._dynamo.exc import UserError, UserErrorType
from torch._dynamo.source import ConstantSource
from torch._export.passes.collect_tracepoints_pass import CollectTracepointsPass
from torch._functorch.aot_autograd import aot_export_module, GraphSignature
from torch._functorch.eager_transforms import functionalize
from torch._guards import detect_fake_mode
from torch._ops import OpOverload
from torch._subclasses.fake_tensor import FakeTensor, FakeTensorMode
from torch.export import _create_constraint, _Dim, Constraint
from torch.export.exported_program import (
    ExportedProgram,
    ModuleCallEntry,
    ModuleCallSignature,
    _disable_prexisiting_fake_mode,
)
from torch.export.graph_signature import (
    _sig_to_specs,
    ArgumentSpec,
    ConstantArgument,
    ExportGraphSignature,
    InputKind,
    InputSpec,
    OutputKind,
    OutputSpec,
    SymIntArgument,
    TensorArgument,
)
from torch.fx import traceback as fx_traceback
from torch.fx._compatibility import compatibility
from torch.fx.experimental.proxy_tensor import make_fx, maybe_disable_fake_tensor_mode
from torch.fx.experimental.symbolic_shapes import (
    ConstraintViolationError,
    GuardOnDataDependentSymNode,
    ShapeEnv,
    StrictMinMaxConstraint,
)
from torch.fx.graph import _PyTreeCodeGen, _PyTreeInfo
from torch.utils._sympy.value_ranges import ValueRangeError, ValueRanges

from .exported_program import (
    _create_stateful_graph_module,
    _process_constraints,
    CallSpec,
)
from .passes.add_runtime_assertions_for_constraints_pass import (
    _AddRuntimeAssertionsForInlineConstraintsPass,
)
from .passes.lift_constant_tensor_pass import lift_constant_tensor_pass
from .passes.remove_runtime_assertions import _RemoveRuntimeAssertionsPass
from .passes.replace_sym_size_ops_pass import _replace_sym_size_ops_pass
from .passes.replace_view_ops_with_view_copy_ops_pass import (
    ReplaceViewOpsWithViewCopyOpsPass,
)
from .wrappers import _wrap_submodules


def _process_dynamic_shapes(
    f: Callable,
    args: Tuple[Any, ...],
    kwargs: Optional[Dict[str, Any]] = None,
    dynamic_shapes: Optional[Union[Dict[str, Any], Tuple[Any]]] = None,
) -> Optional[List[Constraint]]:
    if dynamic_shapes is None or len(dynamic_shapes) == 0:
        return None

    kwargs = kwargs if kwargs is not None else {}

    from collections.abc import Mapping, Sequence

    def tree_zip(combined_args, dynamic_shapes):
        if isinstance(combined_args, (tuple, list)):
            if not isinstance(dynamic_shapes, Sequence):
                raise UserError(
                    UserErrorType.INVALID_INPUT,
                    f"Expected dynamic_shapes of a {type(combined_args)} to be a Sequence, "
                    f"got {dynamic_shapes} instead",
                )
            if len(combined_args) != len(dynamic_shapes):
                raise UserError(
                    UserErrorType.INVALID_INPUT,
                    f"Expected {dynamic_shapes} to have {len(combined_args)} items",
                )
            for i, shape in enumerate(dynamic_shapes):
                yield from tree_zip(combined_args[i], shape)
        elif isinstance(combined_args, dict):
            if not isinstance(dynamic_shapes, Mapping):
                raise UserError(
                    UserErrorType.INVALID_INPUT,
                    f"Expected dynamic_shapes of a {type(combined_args)} to be a Mapping, "
                    f"got {dynamic_shapes} instead",
                )
            if len(combined_args) != len(dynamic_shapes):
                raise UserError(
                    UserErrorType.INVALID_INPUT,
                    f"Expected {dynamic_shapes} to have {len(combined_args)} items",
                )
            for k, shape in dynamic_shapes.items():
                yield from tree_zip(combined_args[k], shape)
        elif dataclasses.is_dataclass(combined_args):
            if not type(dynamic_shapes) == type(combined_args):
                raise UserError(
                    UserErrorType.INVALID_INPUT,
                    f"Expected dynamic_shapes of a {type(combined_args)} to be a {type(combined_args)}, "
                    f"got {dynamic_shapes} instead",
                )
            for f in dataclasses.fields(combined_args):
                yield from tree_zip(getattr(combined_args, f.name), getattr(dynamic_shapes, f.name))
        elif isinstance(combined_args, torch.Tensor):
            yield (combined_args, dynamic_shapes)
        else:
            if dynamic_shapes is not None:
                raise UserError(
                    UserErrorType.INVALID_INPUT,
                    f"Expected dynamic_shapes of a {type(combined_args)} to be None, "
                    f"got {dynamic_shapes} instead",
                )

    def to_constraint(dim, tensor, i):
        constraint = dynamic_dim(tensor, i, debug_name=dim.__name__)
        if dim.min != 2:
            constraint = constraint >= dim.min
        if dim.max != sys.maxsize - 1:
            constraint = constraint <= dim.max
        return constraint

    from collections import defaultdict
    symbols = defaultdict(list)
    bounds: Dict[str, Tuple[int, int]] = {}

    def check_same_bounds(dim):
        if dim.__name__ in symbols:
            min_, max_ = bounds[dim.__name__]
            if dim.min != min_ or dim.max != max_:
                this_ = _Dim.readable(dim.__name__, min_, max_)
                that_ = _Dim.readable(dim.__name__, dim.min, dim.max)
                raise UserError(
                    UserErrorType.INVALID_INPUT,
                    f"Found different definitions {this_} and {that_} "
                    f"for the same symbolic dimension {dim}!"
                )

        else:
            bounds[dim.__name__] = (dim.min, dim.max)

    def update_symbols(tensor, shape):
        if isinstance(shape, dict):
            for i, dim in shape.items():
                if isinstance(dim, _Dim):
                    check_same_bounds(dim)
                    symbols[dim.__name__].append(to_constraint(dim, tensor, i))
                else:
                    if dim is not None:
                        raise UserError(
                            UserErrorType.INVALID_INPUT,
                            f"Unexpected item #{i} ({dim}) in dynamic_shape {shape} of Tensor, "
                            "try None instead",
                        )
        elif isinstance(shape, (tuple, list)):
            for i, dim in enumerate(shape):
                if isinstance(dim, _Dim):
                    check_same_bounds(dim)
                    symbols[dim.__name__].append(to_constraint(dim, tensor, i))
                else:
                    if dim is not None:
                        raise UserError(
                            UserErrorType.INVALID_INPUT,
                            f"Unexpected item #{i} ({dim}) in dynamic_shape {shape} of Tensor, "
                            "try None instead",
                        )
        else:
            if shape is not None:
                raise UserError(
                    UserErrorType.INVALID_INPUT,
                    f"Unexpected dynamic_shape {shape} of Tensor, "
                    "try None instead",
                )

    import inspect
    if isinstance(f, ExportedProgram):
        f = f.module()
    signature = inspect.signature(f.forward) if isinstance(f, torch.nn.Module) else inspect.signature(f)
    combined_args = signature.bind(*args, **kwargs).arguments

    # This means user didn't specify dynamic shapes with argument names.
    combined_args = combined_args if isinstance(dynamic_shapes, Mapping) else list(combined_args.values())  # type: ignore[assignment]
    for tensor, shape in tree_zip(combined_args, dynamic_shapes):
        update_symbols(tensor, shape)

    constraints = []
    for dynamic_dims in symbols.values():
        primary, *others = dynamic_dims
        if others:
            for other in others:
                constraints.append(primary == other)
        else:
            constraints.append(primary)

    return constraints


def export__RC__(
    f: Callable,
    args: Tuple[Any, ...],
    kwargs: Optional[Dict[str, Any]] = None,
    *,
    dynamic_shapes: Optional[Union[Dict[str, Any], Tuple[Any]]] = None,
    strict: bool = True,
    preserve_module_call_signature: Tuple[str, ...] = (),
) -> ExportedProgram:
    """
    API for exporting with dynamic shape specifications instead of constraints.
    It should be considered "release candidate" (RC), meant to replace `export`.

    Here, `dynamic_shapes` is expected to be a dict from
    argument names of `f` to dynamic shape specifications OR a tuple where each element
    corresponds to the original order of the arguments defined in the function signature
    ,as follows:
    - The dynamic shape of a tensor argument can be specified as:
      - Either a dict from dynamic dimension indices to Dim types. It is not
        required to include static dimension indices in this dict, but when
        they are, they should be mapped to None.
      - Or a tuple of Dim types or None. The Dim types correspond to dynamic
        dimensions, whereas static dimensions are denoted by None.
    - Arguments that are dicts or tuples of tensors are recursively specified
      by using mappings or sequences of contained specifications.

    See `export` for documentation of `f`, `args`, `kwargs` and return.
    """
    constraints = _process_dynamic_shapes(f, args, kwargs, dynamic_shapes)
    return _export(
        f,
        args,
        kwargs,
        constraints=constraints,
        strict=strict,
        preserve_module_call_signature=preserve_module_call_signature
    )


def dynamic_dim(t: torch.Tensor, index: int, debug_name: Optional[str] = None):
    if not isinstance(t, torch.Tensor):
        raise UserError(
            UserErrorType.DYNAMIC_DIM,
            f"Expected tensor as input to dynamic_dim but got {type(t)}"
        )

    if t.dim() < 1:
        raise UserError(
            UserErrorType.DYNAMIC_DIM,
            "Cannot mark 0-dimension tensors to be dynamic"
        )

    if index >= t.dim():
        raise UserError(
            UserErrorType.DYNAMIC_DIM,
            f"Expected the dimension passed to dynamic_dim to be in the range [0:{t.dim()-1}]"
            f" but got {index}, which is out of bounds for the given tensor."
        )

    return _create_constraint(
        weakref.ref(t),
        id(t),
        index,
        StrictMinMaxConstraint(
            vr=ValueRanges(lower=2, upper=sympy.oo), warn_only=False
        ),
        debug_name=debug_name,
    )


@dataclasses.dataclass
class ExportDynamoConfig:
    """
    Manage Export-specific configurations of Dynamo.
    """
    allow_rnn: bool = True

DEFAULT_EXPORT_DYNAMO_CONFIG = ExportDynamoConfig()


DECOMP_TABLE = core_aten_decompositions()


# TODO(zhxchen17) This is not needed if we output pre_dispatch graph upfront from export().
@contextmanager
def _disable_decomp_table():
    global DECOMP_TABLE
    prev, DECOMP_TABLE = DECOMP_TABLE, {}
    try:
        yield
    finally:
        DECOMP_TABLE = prev


@compatibility(is_backward_compatible=False)
def capture_pre_autograd_graph(
    f: Callable,
    args: Tuple[Any],
    kwargs: Optional[Dict[str, Any]] = None,
    constraints: Optional[List[Constraint]] = None,
) -> torch.nn.Module:
    """
    A helper function that is intended to trace a module before any pre-autograd
    decomposition is run. The produced module will be "non-functional" and
    composed of aten operators. Later this API will be deleted in favor of more general
    torch.export API.

    Args:
      f: A callable to be traced

      args: example positional inputs.

      kwargs: optional example keyword inputs.

      constraints: A optional list of constraints on the dynamic arguments specifying
            their possible range of their shapes

    Returns:
        An nn.Module containing the traced method.

    """

    decomp_table = {
        torch.ops.aten.dropout.default: torch.ops.aten.dropout.default.decompose,
        torch.ops.aten.batch_norm.default: torch.ops.aten.batch_norm.default.decompose,
        torch.ops.aten._batch_norm_impl_index.default: torch.ops.aten._batch_norm_impl_index.default.decompose,
        torch.ops.aten.native_batch_norm.default: torch.ops.aten.native_batch_norm.default.decompose,
    }

    if kwargs is None:
        kwargs = {}

    with torch._dynamo.config.patch(dataclasses.asdict(DEFAULT_EXPORT_DYNAMO_CONFIG)):
        m = torch._dynamo.export(
            f,
            constraints=constraints,
            assume_static_by_default=True,
            tracing_mode="symbolic",
            decomposition_table=decomp_table,
            pre_dispatch=True,
            aten_graph=True,
        )(
            *args,
            **kwargs,
        )[0]

        def _train(self, mode: bool = True):
            raise NotImplementedError("Calling train() is not supported yet.")

        def _eval(self, mode: bool = True):
            raise NotImplementedError("Calling eval() is not supported yet.")

        _, _, _, fake_mode = _convert_input_to_fake(m, args, kwargs)

        m.meta["inline_constraints"] = {
            k: v
            for k, v in fake_mode.shape_env.runtime_var_to_range.items()
            if re.match(r"^[if]\d+$", str(k))
        }

        flat_args, _ = pytree.tree_flatten((args, kwargs or {}))
        range_constraints, equality_constraints = _process_constraints(m, 0, flat_args)
        unlifted_m = _create_stateful_graph_module(
            m,
            range_constraints=range_constraints,
            equality_constraints=equality_constraints,
        )
        unlifted_m.train = types.MethodType(_train, m)  # type: ignore[method-assign]
        unlifted_m.eval = types.MethodType(_eval, m)  # type: ignore[method-assign]
        return unlifted_m


def _convert_input_to_fake(gm, args, kwargs):
    if len(args) == 0 and len(kwargs) == 0 and len(dict(gm.named_parameters())) == 0 and len(dict(gm.named_buffers())) == 0:
        return [], {}, {}, None

    fake_inps: List[torch.Tensor] = []
    fake_mode = None
    for node in gm.graph.nodes:
        if node.op == "placeholder" and "val" in node.meta:
            fake_val = node.meta["val"]
            if fake_val is not None and isinstance(fake_val, torch.Tensor):
                fake_inps.append(fake_val)

    if detected_fake_mode := detect_fake_mode(fake_inps):
        fake_mode = detected_fake_mode

    assert fake_mode is not None, "Cannot find fake_mode attatched to the graph's placeholders."

    count = 0

    def convert_to_fake(x):
        nonlocal count
        val = fake_inps[count]
        count += 1
        return val

    fake_args = pytree.tree_map_only(torch.Tensor, convert_to_fake, args)
    # TODO properly use the cached fake tensor
    fake_kwargs = pytree.tree_map_only(torch.Tensor, fake_mode.from_tensor, kwargs)
    fake_params_buffers = pytree.tree_map_only(torch.Tensor,
                                               functools.partial(fake_mode.from_tensor, static_shapes=True),
                                               {**dict(gm.named_parameters(remove_duplicate=False)),
                                                **dict(gm.named_buffers(remove_duplicate=False))})
    return fake_args, fake_kwargs, fake_params_buffers, fake_mode


def _replace_param_buffer_names(param_buffer_table, sig):
    for spec in sig.input_specs:
        spec.target = param_buffer_table.get(spec.target, spec.target)
    for spec in sig.output_specs:
        spec.target = param_buffer_table.get(spec.target, spec.target)


def _normalize_nn_module_stack(gm_torch_level, root_cls):
    # Append a root module to every nn_module_stack.
    root = "L['self']"
    root_key = re.sub(r'[^a-zA-Z0-9]', '_', root)
    for gm in gm_torch_level.modules():
        if not isinstance(gm, torch.fx.GraphModule):
            continue
        for node in gm.graph.nodes:
            if node.op in ["placeholder", "output"]:
                continue
            add_root = True
            if nn_module_stack := node.meta.get("nn_module_stack", {}):
                path, ty = next(iter(nn_module_stack.values()))
                assert issubclass(ty, torch.nn.Module)
                # TODO Figure out why sometimes we have root sometimes we don't.
                if path == root and ty is root_cls:
                    add_root = False
            if add_root:
                def normalize_path(path):
                    try:
                        parts = []

                        class Path:
                            def __getattr__(self, name):
                                parts.append(name)
                                return self

                            def __getitem__(self, idx):
                                parts.append(str(idx))
                                return self

                        eval(path, {"L": {"self": Path()}})
                        return ".".join(parts)
                    except Exception:  # TODO(zhxchen17) Remove this.
                        return path

                nn_module_stack = {root_key: (root, root_cls), **nn_module_stack}
                node.meta["nn_module_stack"] = {
                    key: (normalize_path(path), ty)
                    for key, (path, ty) in nn_module_stack.items()
                }

def _export_to_torch_ir(
    f: Callable,
    args: Tuple[Any, ...],
    kwargs: Optional[Dict[str, Any]] = None,
    constraints: Optional[List[Constraint]] = None,
    *,
    preserve_module_call_signature: Tuple[str, ...] = (),
    disable_constraint_solver: bool = False,
) -> torch.fx.GraphModule:
    """
    Traces either an nn.Module's forward function or just a callable with PyTorch
    operations inside and produce a torch.fx.GraphModule in torch IR.
    """

    constraints = constraints or []
    kwargs = kwargs or {}

    if not isinstance(args, tuple):
        raise UserError(UserErrorType.INVALID_INPUT,
                        f"Expecting `args` to be a tuple of example positional inputs, got {type(args)}")

    # We convert to nn.Module because __call__ of ExportedProgram
    # is untracable right now.
    if isinstance(f, ExportedProgram):
        f = f.module()

    with torch._dynamo.config.patch(dataclasses.asdict(DEFAULT_EXPORT_DYNAMO_CONFIG)):
        try:
            module_call_specs: Dict[str, Dict[str, pytree.TreeSpec]] = {}
            with _wrap_submodules(f, preserve_module_call_signature, module_call_specs):
                gm_torch_level, _ = torch._dynamo.export(
                    f,
                    constraints=constraints,
                    assume_static_by_default=True,
                    tracing_mode="symbolic",
                    disable_constraint_solver=disable_constraint_solver,
                )(
                    *args,
                    **kwargs,
                )
        except (ConstraintViolationError, ValueRangeError) as e:
            raise UserError(UserErrorType.CONSTRAINT_VIOLATION, str(e))  # noqa: TRY200
        except GuardOnDataDependentSymNode as e:
            raise UserError(  # noqa: TRY200
                UserErrorType.ANTI_PATTERN,
                f"Consider annotating your code using torch._constrain_as_*(). {str(e)}",
                case_name="constrain_as_size_example",
            )

    gm_torch_level.meta["module_call_specs"] = module_call_specs
    return gm_torch_level


def export(
    f: Callable,
    args: Tuple[Any, ...],
    kwargs: Optional[Dict[str, Any]] = None,
    constraints: Optional[List[Constraint]] = None,
    *,
    strict: bool = True,
    preserve_module_call_signature: Tuple[str, ...] = (),
) -> ExportedProgram:

    if constraints is not None:
        warnings.warn(
            "Using `constraints` to specify dynamic shapes for export is DEPRECATED "
            "and will not be supported in the future. "
            "Please use `dynamic_shapes` instead (see docs on `torch.export.export`).",
            DeprecationWarning,
            stacklevel=2,
        )
    return _export(
        f,
        args,
        kwargs,
        constraints,
        strict=strict,
        preserve_module_call_signature=preserve_module_call_signature,
    )


def _unlift_user_inputs_to_buffers(
    gm_torch_level: torch.fx.GraphModule,
    aot_export_args
) -> List[str]:
    flat_args = pytree.tree_leaves(aot_export_args)
    user_input_names = []
    with gm_torch_level.graph.inserting_before():
        for i, (arg, node) in enumerate(zip(flat_args, gm_torch_level.graph.nodes)):
            assert node.op == "placeholder"
            user_input_names.append(node.name)
            if isinstance(arg, torch.Tensor):
                assert not hasattr(gm_torch_level, node.name)
                gm_torch_level.register_buffer(node.name, arg)
                get_attr = gm_torch_level.graph.get_attr(node.name)
                node.replace_all_uses_with(get_attr)
                get_attr.meta = copy.copy(node.meta)

    for node in list(gm_torch_level.graph.nodes):
        if node.op == "placeholder":
            assert len(node.users) == 0
            gm_torch_level.graph.erase_node(node)
    gm_torch_level.recompile()
    return user_input_names


def _lift_buffers_to_user_inputs(
    gm: torch.fx.GraphModule,
    graph_signature: GraphSignature,
    user_input_names: List[str]
) -> Dict[str, str]:
    assert len(graph_signature.user_inputs) == 0
    assert graph_signature.backward_signature is None
    names = set(user_input_names)

    placeholders = [node for node in gm.graph.nodes if node.op == "placeholder"]
    # user inputs are always added in the end
    start = len(graph_signature.parameters)
    end = start + len(graph_signature.buffers)
    buffer_nodes = placeholders[start:end]
    last_placeholder_node = placeholders[-1] if len(placeholders) > 0 else None
    old_nodes: Dict[str, torch.fx.Node] = {}
    for node in buffer_nodes:
        buffer_name = graph_signature.inputs_to_buffers[node.name]
        if buffer_name not in names:
            continue
        old_nodes[buffer_name] = node
    replaces = {}
    new_node_names: Dict[str, str] = {}
    with gm.graph.inserting_after(last_placeholder_node):
        for name in reversed(user_input_names):
            new_node = gm.graph.placeholder(name)
            new_node.target = new_node.name
            new_node_names[name] = new_node.name
            if name in old_nodes:
                old_node = old_nodes[name]
                new_node.meta = copy.copy(old_node.meta)
                old_node.replace_all_uses_with(new_node)
                replaces[old_node.name] = new_node.name
    new_node_names = dict(reversed(new_node_names.items()))
    for old_node in old_nodes.values():
        gm.graph.erase_node(old_node)

    gm.recompile()

    graph_signature.buffers = [b for b in graph_signature.buffers if b not in names]
    graph_signature.inputs_to_buffers = {
        i: b for i, b in graph_signature.inputs_to_buffers.items() if b not in names
    }
    user_inputs_to_mutate = {
        o: b for o, b in graph_signature.buffers_to_mutate.items() if b in names
    }
    graph_signature.buffers_to_mutate = {
        o: b for o, b in graph_signature.buffers_to_mutate.items() if b not in names
    }
    graph_signature.user_inputs.extend(new_node_names.values())  # type: ignore[arg-type]
    graph_signature.user_outputs = [
        replaces[o] if o in replaces else o for o in graph_signature.user_outputs
    ]
    return user_inputs_to_mutate  # type: ignore[return-value]


def _export_non_strict(
    mod,
    fake_args,
    fake_kwargs,
    fake_params_buffers,
    *,
    transform=lambda x: x  # TODO(zhxchen17) Revisit if this is needed later.
):
    # This _reparametrize_module makes sure inputs and module.params/buffers have the same fake_mode,
    # otherwise aot_export_module will error out because it sees a mix of fake_modes.
    # And we want aot_export_module to use the fake_tensor mode in dynamo to keep the pipeline easy to reason about.
    with torch.nn.utils.stateless._reparametrize_module(mod, fake_params_buffers):
        gm, graph_signature = transform(aot_export_module)(
            mod,
            (*fake_args, *fake_kwargs.values()),
            trace_joint=False
        )

    # NOTE: aot_export adds symint metadata for placeholders with int values;
    # since these become specialized, we replace such metadata with the original values
    flat_args = pytree.tree_leaves((fake_args, fake_kwargs))
    index = 0
    total_param_buffers = len(graph_signature.parameters) + len(graph_signature.buffers)
    for node in gm.graph.nodes:
        if node.op == "placeholder":
            if index >= total_param_buffers:
                user_arg = flat_args[index - total_param_buffers]
                if not isinstance(user_arg, torch.Tensor):
                    node.meta["val"] = user_arg
            index += 1

    is_joint = graph_signature.backward_signature is not None

    def make_argument_spec(node) -> ArgumentSpec:
        assert "val" in node.meta, f"{node} has no 'val' metadata field"
        val = node.meta["val"]
        if isinstance(val, FakeTensor):
            return TensorArgument(name=node.name)
        elif isinstance(val, torch.SymInt):
            return SymIntArgument(name=node.name)
        else:
            return ConstantArgument(value=val)

    input_specs, output_specs = _sig_to_specs(
        user_inputs=set(graph_signature.user_inputs),
        inputs_to_parameters=graph_signature.inputs_to_parameters,  # type: ignore[arg-type]
        inputs_to_buffers=graph_signature.inputs_to_buffers,  # type: ignore[arg-type]
        user_outputs=set(graph_signature.user_outputs),  # type: ignore[arg-type]
        buffer_mutations=graph_signature.buffers_to_mutate,  # type: ignore[arg-type]
        user_input_mutations=gm.meta.get("user_inputs_to_mutate", {}),  # type: ignore[arg-type]
        grad_params=graph_signature.backward_signature.gradients_to_parameters if is_joint else {},  # type: ignore[arg-type, union-attr]
        grad_user_inputs=graph_signature.backward_signature.gradients_to_user_inputs if is_joint else {},  # type: ignore[arg-type, union-attr]
        loss_output=graph_signature.backward_signature.loss_output if is_joint else None,  # type: ignore[arg-type, union-attr]
        inputs=[make_argument_spec(node) for node in gm.graph.nodes if node.op == "placeholder"],
        outputs=[make_argument_spec(node) for node in pytree.tree_leaves(next(iter(reversed(gm.graph.nodes))).args)],
    )
    export_graph_signature = ExportGraphSignature(input_specs=input_specs, output_specs=output_specs)

    tensor_constants = lift_constant_tensor_pass(gm, export_graph_signature)

    @dataclasses.dataclass
    class _ExportedProgramNonStrict:
        gm: torch.fx.GraphModule
        sig: ExportGraphSignature
        tensor_constants: Dict[str, torch.Tensor]

    return _ExportedProgramNonStrict(
        gm,
        export_graph_signature,
        tensor_constants,
    )


def _get_params_buffers(mod: torch.nn.Module) -> Dict[str, torch.Tensor]:
    params_buffers: Dict[str, torch.Tensor] = {}
    for name, param in mod.named_parameters(remove_duplicate=False):
        params_buffers[name] = param

    for name, buffer in mod.named_buffers(remove_duplicate=False):
        params_buffers[name] = buffer
    return params_buffers


@_disable_prexisiting_fake_mode
def _export(
    f: Callable,
    args: Tuple[Any, ...],
    kwargs: Optional[Dict[str, Any]] = None,
    constraints: Optional[List[Constraint]] = None,
    *,
    strict: bool = True,
    preserve_module_call_signature: Tuple[str, ...] = (),
) -> ExportedProgram:
    """
    Traces either an nn.Module's forward function or just a callable with PyTorch
    operations inside and produce a ExportedProgram.

    Args:
        m: the `nn.Module` or callable to trace.

        args: example positional inputs.

        kwargs: optional example keyword inputs.

        constraints: A optional list of constraints on the dynamic arguments specifying
            their possible range of their shapes

        preserve_module_call_signature: A list of submodule paths for which the original
            calling conventions are preserved as metadata.

    Returns:
        An ExportedProgram containing the traced method.
    """
    constraints = constraints or []
    kwargs = kwargs or {}

    if not strict:
        assert isinstance(f, torch.nn.Module)
        assert len(preserve_module_call_signature) == 0
        assert len(constraints) == 0, "dynamic shape NYI"
        assert len(kwargs) == 0, "keyword arguments NYI"
        out_spec = None

        def _tuplify_outputs(aot_export):
            def _aot_export_non_strict(mod, args, **kwargs):
                class Wrapper(torch.nn.Module):
                    def __init__(self, mod):
                        super().__init__()
                        self._export_root = mod

                    def forward(self, *args, **kwargs):
                        nonlocal out_spec
                        flat_outs, out_spec = pytree.tree_flatten(self._export_root(*args, **kwargs))
                        return tuple(flat_outs)

                gm, sig = aot_export(Wrapper(mod), args, **kwargs)

                def strip_root(x):
                    return x[len('_export_root.'):] if x.startswith('_export_root.') else x

                sig.parameters = pytree.tree_map(strip_root, sig.parameters)
                sig.buffers = pytree.tree_map(strip_root, sig.buffers)
                sig.inputs_to_buffers = pytree.tree_map(strip_root, sig.inputs_to_buffers)
                sig.inputs_to_parameters = pytree.tree_map(strip_root, sig.inputs_to_parameters)
                sig.buffers_to_mutate = pytree.tree_map(strip_root, sig.buffers_to_mutate)
                return gm, sig
            return _aot_export_non_strict
        ep_non_strict = _export_non_strict(f, args, {}, f.state_dict(), transform=_tuplify_outputs)
        assert out_spec is not None
        return ExportedProgram(
            ep_non_strict.gm,
            ep_non_strict.gm.graph,
            ep_non_strict.sig,
            _get_params_buffers(f),
            {},
            [],
            [ModuleCallEntry("", ModuleCallSignature([], [], pytree.tree_flatten((args, {}))[1], out_spec))],
            (args, kwargs),
            tensor_constants=ep_non_strict.tensor_constants,
        )


    gm_torch_level = _export_to_torch_ir(
        f,
        args,
        kwargs,
        constraints,
        preserve_module_call_signature=preserve_module_call_signature,
    )

    params_buffers = _get_params_buffers(gm_torch_level)

    # We detect the fake_mode by looking at gm_torch_level's placeholders, this is the fake_mode created in dynamo.
    fake_args, fake_kwargs, fake_params_buffers, dynamo_fake_mode = _convert_input_to_fake(gm_torch_level, args, kwargs)

    # First, we want to pass through the graph to try populating
    # val field for getattr if there is anything missing.
    # THis can happen when quantization adds extra params and forgets
    # to update "val"
    for node in gm_torch_level.graph.nodes:
        if node.op == "get_attr" and "val" not in node.meta:
            attr = getattr(gm_torch_level, node.target)
            # Checks if it is not a HigherOrderOp branch or a module
            if not isinstance(attr, torch.nn.Module):
                assert dynamo_fake_mode is not None, (
                    "Cannot find dynamo_fake_mode. This could be due to the exported graph module have no placeholders."
                )
                node.meta["val"] = dynamo_fake_mode.from_tensor(attr, static_shapes=True)

    # When aot_export lifts the params, we lose the nn_module_stack
    # and source_fn from the param nodes as they are treated as fresh inputs
    # Therefore, we manually extract them before calling into aot_export
    params_buffers_to_node_meta = {}
    for node in gm_torch_level.graph.nodes:
        target = node.target
        meta = node.meta
        if node.op == "call_module":
            submodule = getattr(gm_torch_level, target)
            if isinstance(submodule, torch.nn.Module):
                for name, _ in submodule.named_parameters(recurse=True, remove_duplicate=False):
                    params_buffers_to_node_meta[target + "." + name] = meta

                for name, _ in submodule.named_buffers(recurse=True, remove_duplicate=False):
                    params_buffers_to_node_meta[target + "." + name] = meta

        if node.op == "get_attr":
            submodule = getattr(gm_torch_level, target)
            if not isinstance(submodule, torch.fx.GraphModule):
                params_buffers_to_node_meta[target] = meta

        # If the call_function uses param as input, we also need to update params' meta
        # with this call_function node's meta.
        # This is basically the same flow as torch.fx.traceback.preserve_meta()
        if node.op == "call_function" and not isinstance(node.target, torch._ops.HigherOrderOperator):
            for arg in node._input_nodes:
                if arg.op == "get_attr":
                    for entry in torch.fx.proxy._COPY_META_FIELDS:
                        if entry in meta:
                            params_buffers_to_node_meta[arg.target][entry] = meta[entry]

    # Fix the graph output signature to be tuple if scalar
    out_spec = orig_out_spec = gm_torch_level._out_spec
    assert out_spec is not None
    # aot_export expect the return type to always be a tuple.
    if out_spec.type not in (list, tuple):
        out_spec = pytree.TreeSpec(tuple, None, [out_spec])

    orig_args = gm_torch_level.graph._codegen.pytree_info.orig_args  # type: ignore[attr-defined]

    gm_torch_level.graph._codegen = _PyTreeCodeGen(
        _PyTreeInfo(
            orig_args,
            gm_torch_level._in_spec,
            out_spec,
        )
    )
    gm_torch_level.recompile()

    param_buffer_table: Dict[str, str] = {}
    if isinstance(f, torch.nn.Module):
        param_lookup: Dict[int, List[str]] = {}
        buffer_lookup: Dict[int, List[str]] = {}
        for name, param in f.named_parameters(remove_duplicate=False):
            param_lookup.setdefault(id(param), []).append(name)
        for name, buffer in f.named_buffers(remove_duplicate=False):
            buffer_lookup.setdefault(id(buffer), []).append(name)
        for dynamo_name, dynamo_param in gm_torch_level.named_parameters(remove_duplicate=False):
            assert dynamo_name not in param_buffer_table
            if id(dynamo_param) in param_lookup:
                param_buffer_table[dynamo_name] = param_lookup[id(dynamo_param)].pop()

        for dynamo_name, dynamo_buffer in gm_torch_level.named_buffers(remove_duplicate=False):
            assert dynamo_name not in param_buffer_table
            if id(dynamo_buffer) in buffer_lookup:
                param_buffer_table[dynamo_name] = buffer_lookup[id(dynamo_buffer)].pop()

    if isinstance(f, torch.nn.Module):
        _normalize_nn_module_stack(gm_torch_level, type(f))

    def _process_user_inputs(aot_export):
        def _aot_export_strict(gm_torch_level: torch.fx.GraphModule, args, **kwargs):
            user_input_names = _unlift_user_inputs_to_buffers(gm_torch_level, args)
            gm, graph_signature = aot_export(gm_torch_level, (), **kwargs)
            user_inputs_to_mutate = _lift_buffers_to_user_inputs(gm, graph_signature, user_input_names)
            # TODO unfortunately preserving graph-level metadata is not
            # working well with aot_export. So we manually copy it.
            # (The node-level meta is addressed above.)
            gm.meta.update(gm_torch_level.meta)
            assert "user_inputs_to_mutate" not in gm.meta
            gm.meta["user_inputs_to_mutate"] = user_inputs_to_mutate
            return gm, graph_signature

        return _aot_export_strict

    # Note: aot_export_module doesn't accept kwargs, we'd like to reorder the kwargs as an OrderedDict
    # to follow the order in orig_args and correctly call module
    ep_non_strict = _export_non_strict(
        gm_torch_level,
        fake_args,
        _reorder_kwargs_by_names(orig_args, fake_args, fake_kwargs),
        fake_params_buffers,
        transform=_process_user_inputs
    )

    gm = ep_non_strict.gm
    export_graph_signature = ep_non_strict.sig
    tensor_constants = ep_non_strict.tensor_constants

    # After aot_export, set the param/buffer metadata back into placeholders
    # Technically, users can still construct this data from param names
    # without relying on this metadata
    for node in gm.graph.nodes:
        if node.op == "placeholder":
            if node.target in export_graph_signature.inputs_to_parameters:
                param_name = export_graph_signature.inputs_to_parameters[node.target]
                if param_name in params_buffers_to_node_meta:
                    for k, v in params_buffers_to_node_meta[param_name].items():
                        node.meta[k] = v
            if node.target in export_graph_signature.inputs_to_buffers:
                buffer_name = export_graph_signature.inputs_to_buffers[node.target]
                if buffer_name in params_buffers_to_node_meta:
                    for k, v in params_buffers_to_node_meta[buffer_name].items():
                        node.meta[k] = v

    # The unbacked symint symbols are updated in aot_export
    # so we serialize them here instead of inside dynamo

    # dynamo_fake_mode can be None if there's no placeholder in gm_torch_level
    if dynamo_fake_mode:
        gm.meta["inline_constraints"] = {
            k: v
            for k, v in dynamo_fake_mode.shape_env.runtime_var_to_range.items()
            if re.match(r"^[if]\d+$", str(k))
        }

    num_lifted = next(
        (i for i, s in enumerate(export_graph_signature.input_specs) if s.kind == InputKind.USER_INPUT), 0
    )
    flat_args, orig_in_spec = pytree.tree_flatten((args, kwargs))
    range_constraints, equality_constraints = _process_constraints(
        gm,
        num_lifted,
        flat_args,
    )

    if isinstance(f, torch.nn.Module):
        _replace_param_buffer_names(param_buffer_table, export_graph_signature)
        params_buffers = {param_buffer_table.get(name, name): tensor for name, tensor in params_buffers.items()}

    module_call_signatures = {
        fqn: ModuleCallSignature(inputs=[], outputs=[], **specs)
        for fqn, specs in gm_torch_level.meta["module_call_specs"].items()
    }

    if len(preserve_module_call_signature) > 0:
        res = CollectTracepointsPass(module_call_signatures, export_graph_signature)(gm)
        assert res is not None
        gm = res.graph_module

    assert orig_out_spec is not None
    exported_program = ExportedProgram(
        gm,
        gm.graph,
        export_graph_signature,
        # TODO(zhxchen17) Return empty state_dict for functions.
        params_buffers,
        range_constraints,
        equality_constraints,
        [ModuleCallEntry("", ModuleCallSignature(inputs=[], outputs=[], in_spec=orig_in_spec, out_spec=orig_out_spec))] +
        [ModuleCallEntry(fqn, sig) for fqn, sig in module_call_signatures.items()],
        (args, kwargs),
        tensor_constants=tensor_constants,
    )

    if len(range_constraints) > 0 or len(equality_constraints) > 0:
        exported_program = exported_program._transform(
            _AddRuntimeAssertionsForInlineConstraintsPass(range_constraints, equality_constraints)
        )

    return exported_program


def _reorder_kwargs_by_names(arg_names: List[str], args: Tuple[Any], kwargs: Dict[str, Any]):
    assert len(arg_names) == len(args) + len(kwargs), (
        f"Total number of arg names is expected to be {len(arg_names)} "
        f"but got {len(args)} positional args, {len(kwargs)} kwargs."
    )
    return {kw_name: kwargs[kw_name] for kw_name in arg_names[len(args):]}


def save(
    ep: ExportedProgram,
    f: Union[str, pathlib.Path, io.BytesIO],
    *,
    extra_files: Optional[Dict[str, Any]] = None,
    opset_version: Optional[Dict[str, int]] = None,
) -> None:
    from .serde.serialize import serialize, SerializedArtifact
    from .serde.schema import SCHEMA_VERSION
    artifact: SerializedArtifact = serialize(ep, opset_version)

    if isinstance(f, (str, pathlib.Path)):
        f = str(f)

    with zipfile.ZipFile(f, 'w') as zipf:
        # Save every field the SerializedArtifact to a file
        for field in dataclasses.fields(artifact):
            field_name = field.name
            serialized_field = getattr(artifact, field_name)
            zipf.writestr(f"serialized_{field_name}.json", serialized_field)

        zipf.writestr('version', str(SCHEMA_VERSION))

        # Add extra files if provided
        if extra_files:
            for extra_file_name, content in extra_files.items():
                encoded_content = content.encode('utf-8')
                zipf.writestr(f"extra_files/{extra_file_name}", encoded_content)


def load(
    f: Union[str, pathlib.Path, io.BytesIO],
    *,
    extra_files: Optional[Dict[str, Any]] = None,
    expected_opset_version: Optional[Dict[str, int]] = None,
) -> ExportedProgram:
    if isinstance(f, (str, pathlib.Path)):
        f = str(f)

    with zipfile.ZipFile(f, 'r') as zipf:
        # Check the version
        version = int(zipf.read('version'))
        from .serde.schema import SCHEMA_VERSION

        if version != SCHEMA_VERSION:
            raise RuntimeError(
                f"Serialized version {version} does not match our current "
                f"schema version {SCHEMA_VERSION}."
            )

        from .serde.serialize import deserialize, SerializedArtifact

        # Load serialized_ep and serialized_state_dict from the zip file
        artifact: SerializedArtifact = SerializedArtifact(
            **{
                field.name: zipf.read(f"serialized_{field.name}.json")
                for field in dataclasses.fields(SerializedArtifact)
            }
        )

        # Deserialize ExportedProgram
        ep = deserialize(artifact)

        # Populate extra_files map
        if extra_files is not None:
            for filename in extra_files.keys():
                extra_files[filename] = zipf.read(f"extra_files/{filename}").decode('utf-8')

        return ep


def aot_compile(
    f: Callable,
    args: Tuple[Any],
    kwargs: Optional[Dict[str, Any]] = None,
    *,
    constraints: Optional[List[Constraint]] = None,
    dynamic_shapes: Optional[Dict[str, Any]] = None,
    options: Optional[Dict[str, Any]] = None,
    remove_runtime_assertions: bool = False,
    disable_constraint_solver: bool = False,
) -> str:
    """
    Note: this function is not stable yet

    Traces either an nn.Module's forward function or just a callable with PyTorch
    operations inside, generates executable cpp code from the program, and returns
    the path to the generated shared library

    Args:
        f: the `nn.Module` or callable to trace.

        args: example positional inputs.

        kwargs: optional example keyword inputs.

        constraints: A optional list of constraints on the dynamic arguments specifying
            their possible range of their shapes

        dynamic_shapes: An experimental new feature designed to subsume ``constraints``.
            A dict mapping argument names of ``f`` to their dynamic shape
            specifications, as follows. Dynamic shape specifications can be a
            dict from dynamic dimensions to ``Dim`` types, or a tuple/list of
            ``Optional[Dim]`` corresponding to each input dimension.

        options: A dictionary of options to control inductor

        disable_constraint_solver: Whether the dim constraint solver must be disabled.

    Returns:
        Path to the generated shared library
    """
    if constraints is not None:
        warnings.warn(
            "The constraints field is deprecated. "
            "Please use dynamic_shapes instead."
        )

    from torch._inductor.decomposition import select_decomp_table

    if constraints is None:
        constraints = _process_dynamic_shapes(f, args, kwargs, dynamic_shapes)

    # We want to export to Torch IR here to utilize the pre_grad passes in
    # inductor, which run on Torch IR.
    gm = _export_to_torch_ir(
        f,
        args,
        kwargs,
        constraints,
        disable_constraint_solver=disable_constraint_solver
    )
    flat_example_inputs = pytree.arg_tree_leaves(*args, **(kwargs or {}))

    with torch.no_grad():
        so_path = torch._inductor.aot_compile(gm, flat_example_inputs, options)  # type: ignore[arg-type]

    return so_path