Improve is_fbcode functionality (#136871)

Summary: Previously is_fbcode just checked whether the checkout was git or not. This is extremely error prone. Lets make it fool-proof.

Test Plan: unit tests

Reviewed By: masnesral

Differential Revision: D63545169

Pull Request resolved: https://github.com/pytorch/pytorch/pull/136871
Approved by: https://github.com/masnesral

test/profiler/test_cpp_thread.py

@@ -7,6 +7,7 @@ from unittest import skipIf
 
 import torch
 import torch.utils.cpp_extension
+from torch._environment import is_fbcode
 from torch.testing._internal.common_utils import IS_WINDOWS, run_tests, TestCase
 
 
@@ -21,10 +22,6 @@ def remove_build_path():
             shutil.rmtree(default_build_root)
 
 
-def is_fbcode():
-    return not hasattr(torch.version, "git_version")
-
-
 if is_fbcode():
     import caffe2.test.profiler_test_cpp_thread_lib as cpp  # @manual=//caffe2/test:profiler_test_cpp_thread_lib
 else:

test/quantization/pt2e/test_numeric_debugger.py

@@ -6,6 +6,7 @@ from collections import Counter
 from typing import Dict
 
 import torch
+from torch._environment import is_fbcode
 from torch._export import capture_pre_autograd_graph
 from torch.ao.quantization import (
     compare_results,
@@ -40,10 +41,6 @@ def _extract_debug_handles(model) -> Dict[str, int]:
     return debug_handle_map
 
 
-def is_fbcode():
-    return not hasattr(torch.version, "git_version")
-
-
 @unittest.skipIf(IS_WINDOWS, "Windows not yet supported for torch.compile")
 class TestNumericDebugger(TestCase):
     def test_simple(self):

torch/_dynamo/config.py

@@ -9,10 +9,7 @@ from os.path import abspath, dirname
 from typing import Any, Callable, Dict, Optional, Set, Type, TYPE_CHECKING, Union
 
 import torch
-
-
-def is_fbcode():
-    return not hasattr(torch.version, "git_version")
+from torch._environment import is_fbcode
 
 
 # to configure logging for dynamo, aot, and inductor

torch/_environment.py

@@ -0,0 +1,2 @@
+def is_fbcode() -> bool:
+    return False

torch/_inductor/config.py

@@ -3,10 +3,7 @@ import sys
 from typing import Any, Callable, Dict, List, Optional, TYPE_CHECKING, Union
 
 import torch
-
-
-def is_fbcode() -> bool:
-    return not hasattr(torch.version, "git_version")
+from torch._environment import is_fbcode
 
 
 def _get_tristate_env(name: str) -> Optional[bool]: