[dynamo] simplify implementation for os.fspath (#133801)

Pull Request resolved: https://github.com/pytorch/pytorch/pull/133801
Approved by: https://github.com/anijain2305

torch/_dynamo/polyfills/__init__.py

@@ -168,15 +168,3 @@ def instantiate_user_defined_class_object(cls, /, *args, **kwargs):
     if isinstance(obj, cls):
         obj.__init__(*args, **kwargs)
     return obj
-
-
-def fspath(path):
-    # Python equivalent of os.fspath
-    if isinstance(path, (str, bytes)):
-        return path
-    elif hasattr(path, "__fspath__"):
-        return path.__fspath__()
-    else:
-        raise TypeError(
-            f"expected str, bytes or os.PathLike object, not {type(path).__name__}"
-        )

torch/_dynamo/polyfills/builtins.py

@@ -0,0 +1,6 @@
+"""
+Python polyfills for builtins
+"""
+
+
+__all__ = []  # type: ignore[var-annotated]

torch/_dynamo/polyfills/functools.py

@@ -0,0 +1,6 @@
+"""
+Python polyfills for functools
+"""
+
+
+__all__ = []  # type: ignore[var-annotated]

torch/_dynamo/polyfills/itertools.py

@@ -0,0 +1,6 @@
+"""
+Python polyfills for itertools
+"""
+
+
+__all__ = []  # type: ignore[var-annotated]

torch/_dynamo/polyfills/loader.py

@@ -11,7 +11,13 @@ if TYPE_CHECKING:
     from types import ModuleType
 
 
-POLYFILLED_MODULE_NAMES: Tuple[str, ...] = ()
+POLYFILLED_MODULE_NAMES: Tuple[str, ...] = (
+    "builtins",
+    "functools",
+    "itertools",
+    "os",
+    "sys",
+)
 POLYFILLED_MODULES: Tuple["ModuleType", ...] = tuple(
     importlib.import_module(f".{submodule}", package=polyfills.__name__)
     for submodule in POLYFILLED_MODULE_NAMES

torch/_dynamo/polyfills/os.py

@@ -0,0 +1,36 @@
+"""
+Python polyfills for os
+"""
+
+from __future__ import annotations
+
+import os
+from typing import AnyStr
+
+from ..decorators import substitute_in_graph
+
+
+__all__ = ["fspath"]
+
+
+# Copied from os.py in the standard library
+@substitute_in_graph(os.fspath)
+def fspath(path: AnyStr | os.PathLike[AnyStr]) -> AnyStr:
+    if isinstance(path, (str, bytes)):
+        return path
+
+    path_type = type(path)
+    try:
+        path_repr = path_type.__fspath__(path)  # type: ignore[arg-type]
+    except AttributeError:
+        if hasattr(path_type, "__fspath__"):
+            raise
+        raise TypeError(
+            f"expected str, bytes or os.PathLike object, not {path_type.__name__}",
+        ) from None
+    if isinstance(path_repr, (str, bytes)):
+        return path_repr  # type: ignore[return-value]
+    raise TypeError(
+        f"expected {path_type.__name__}.__fspath__() to return str or bytes, "
+        f"not {type(path_repr).__name__}",
+    )

torch/_dynamo/polyfills/sys.py

@@ -0,0 +1,6 @@
+"""
+Python polyfills for sys
+"""
+
+
+__all__ = []  # type: ignore[var-annotated]

torch/_dynamo/variables/misc.py

@@ -4,7 +4,6 @@ import dataclasses
 import functools
 import inspect
 import itertools
-import os
 import random
 import re
 import sys
@@ -15,7 +14,7 @@ import torch._C
 import torch._numpy as tnp
 import torch.utils._pytree as pytree
 
-from .. import config, polyfills, variables
+from .. import config, variables
 from ..bytecode_transformation import create_call_function, create_instruction
 from ..create_parameter_op import do_not_convert_to_tracable_parameter
 from ..exc import unimplemented
@@ -30,7 +29,6 @@ from ..source import (
 )
 from ..utils import (
     check_unspec_or_constant_args,
-    hashable,
     identity,
     is_tensor_base_attr_getter,
     proxy_args_kwargs,
@@ -49,10 +47,6 @@ from .user_defined import call_random_fn, is_standard_setattr, UserDefinedObject
 if TYPE_CHECKING:
     from torch._dynamo.symbolic_convert import InstructionTranslator
 
-POLYFILL_SUPPORTED_PYTHON_MODULE_METHODS = {
-    os.fspath: polyfills.fspath,
-}
-
 
 class NO_SUCH_SUBOBJ:
     pass
@@ -1167,12 +1161,6 @@ class PythonModuleVariable(VariableTracker):
         else:
             attr_value = self.value.__dict__[name]
 
-        if hashable(attr_value):
-            if polyfill_fn := POLYFILL_SUPPORTED_PYTHON_MODULE_METHODS.get(
-                attr_value, None
-            ):
-                return variables.UserFunctionVariable(polyfill_fn)
-
         if self.source:
             new_source = AttrSource(self.source, name)
             return VariableBuilder(tx, new_source)(attr_value)