Make pre-commit work on Windows

.github/workflows/ci.yml

@@ -416,6 +416,38 @@ jobs:
     with:
       is-release: ${{ github.ref_type == 'tag' }}
 
+  precommit-windows:
+    name: Pre-commit on Windows
+    runs-on: windows-latest
+    if: ${{ github.repository_owner == 'nvidia' && !fromJSON(needs.should-skip.outputs.skip) }}
+    needs:
+      - should-skip
+    permissions:
+      contents: read
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0  # v7.0.0
+        with:
+          fetch-depth: 1
+          persist-credentials: false
+
+      - name: Set up Python
+        uses: actions/setup-python@ece7cb06caefa5fff74198d8649806c4678c61a1  # v6.3.0
+        with:
+          python-version: '3.13'
+
+      - name: Install pre-commit
+        shell: bash
+        run: |
+          set -euxo pipefail
+          python -m pip install --upgrade pip pre-commit
+
+      - name: Run pre-commit
+        shell: bash
+        run: |
+          set -euxo pipefail
+          SKIP=lychee pre-commit run --all-files
+
   checks:
     name: Check job status
     if: always()
@@ -429,6 +461,7 @@ jobs:
       - test-linux-aarch64
       - test-windows
       - doc
+      - precommit-windows
     steps:
       - name: Exit
         run: |
@@ -461,6 +494,7 @@ jobs:
           check_result "should-skip"    "success" "${{ needs.should-skip.result }}"
           check_result "detect-changes" "success" "${{ needs.detect-changes.result }}"
           check_result "doc"            "success" "${{ needs.doc.result }}"
+          check_result "precommit-windows" "success" "${{ needs.precommit-windows.result }}"
 
           # [doc-only] flips these from 'success' to 'skipped'
           if [[ "$doc_only" == "true" ]]; then expected="skipped"; else expected="success"; fi

.pre-commit-config.yaml

@@ -61,7 +61,7 @@ repos:
 
       - id: stubgen-pyx-cuda-core
         name: Generate .pyi stubs for cuda_core
-        entry: stubgen-pyx cuda_core/cuda --continue-on-error --include-private
+        entry: python ./toolshed/run_stubgen_pyx.py
         language: python
         files: ^cuda_core/cuda/.*\.(pyx|pxd)$
         pass_filenames: false
@@ -95,7 +95,7 @@ repos:
     - id: check-yaml
     - id: debug-statements
     - id: end-of-file-fixer
-      exclude: &gen_exclude '^(?:cuda_python/README\.md|cuda_bindings/cuda/bindings/.*\.in?|cuda_bindings/docs/source/module/.*\.rst?|.*\.pyi)$'
+      exclude: &gen_exclude '^(?:cuda_python/README\.md|(?:.*/)?CLAUDE\.md|(?:.*/)?\.git_archival\.txt|cuda_bindings/cuda/bindings/.*\.in?|cuda_bindings/docs/source/module/.*\.rst?|.*\.pyi)$'
     - id: mixed-line-ending
     - id: trailing-whitespace
       exclude: |

CONTRIBUTING.md

@@ -21,6 +21,7 @@ Thank you for your interest in contributing to CUDA Python! Based on the type of
   - [Table of Contents](#table-of-contents)
   - [Type stubs for cuda.core](#type-stubs-for-cudacore)
   - [Pre-commit](#pre-commit)
+    - [Pre-commit on Windows](#pre-commit-on-windows)
   - [Signing Your Work](#signing-your-work)
   - [Code signing](#code-signing)
   - [Developer Certificate of Origin (DCO)](#developer-certificate-of-origin-dco)
@@ -74,6 +75,17 @@ between commits, leaving stale headers or out-of-date stubs in the history.
 If the hook isn't installed, `pre-commit run` (and CI) will print a visible
 warning reminding you to run `pre-commit install`.
 
+### Pre-commit on Windows
+
+For development on Windows (not WSL), the `lychee` pre-commit task will not work
+when running `pre-commit run --all-files`.  This problem does not occur if you
+install the pre-commit hook and run it automatically as part of your `git
+commit` workflow.  To resolve this, you can either:
+
+1. Run `pre-commit` in Git Bash, rather directly in PowerShell or cmd
+
+2. Skip it by setting the environment variable `SKIP` to `lychee`.  This would
+   be `$env:SKIP = "lychee"` in PowerShell or `set SKIP=lychee` in cmd.
 
 ## Signing Your Work
 

cuda_pathfinder/cuda/pathfinder/_dynamic_libs/load_dl_linux.py

@@ -1,4 +1,4 @@
-# SPDX-FileCopyrightText: Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-FileCopyrightText: Copyright (c) 2025-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 # SPDX-License-Identifier: Apache-2.0
 
 from __future__ import annotations
@@ -7,14 +7,18 @@
 import ctypes
 import ctypes.util
 import os
+import sys
 from typing import TYPE_CHECKING, cast
 
 from cuda.pathfinder._dynamic_libs.load_dl_common import LoadedDL
 
 if TYPE_CHECKING:
     from cuda.pathfinder._dynamic_libs.lib_descriptor import LibDescriptor
 
-CDLL_MODE = os.RTLD_NOW | os.RTLD_GLOBAL
+if sys.platform == "linux":
+    CDLL_MODE = os.RTLD_NOW | os.RTLD_GLOBAL
+else:
+    CDLL_MODE = 0
 
 
 def _load_libdl() -> ctypes.CDLL:
@@ -132,27 +136,35 @@ def _candidate_sonames(desc: LibDescriptor) -> list[str]:
     return candidates
 
 
-def check_if_already_loaded_from_elsewhere(desc: LibDescriptor, _have_abs_path: bool) -> LoadedDL | None:
-    for soname in _candidate_sonames(desc):
-        try:
-            handle = ctypes.CDLL(soname, mode=os.RTLD_NOLOAD)
-        except OSError:
-            continue
-        else:
-            return LoadedDL(
-                abs_path_for_dynamic_library(desc.name, handle),
-                True,
-                handle._handle,
-                "was-already-loaded-from-elsewhere",
-            )
-    return None
-
-
-def _load_lib(desc: LibDescriptor, filename: str) -> ctypes.CDLL:
-    cdll_mode = CDLL_MODE
-    if desc.requires_rtld_deepbind:
-        cdll_mode |= os.RTLD_DEEPBIND
-    return ctypes.CDLL(filename, cdll_mode)
+if sys.platform == "linux":
+
+    def check_if_already_loaded_from_elsewhere(desc: LibDescriptor, _have_abs_path: bool) -> LoadedDL | None:
+        for soname in _candidate_sonames(desc):
+            try:
+                handle = ctypes.CDLL(soname, mode=os.RTLD_NOLOAD)
+            except OSError:
+                continue
+            else:
+                return LoadedDL(
+                    abs_path_for_dynamic_library(desc.name, handle),
+                    True,
+                    handle._handle,
+                    "was-already-loaded-from-elsewhere",
+                )
+        return None
+
+    def _load_lib(desc: LibDescriptor, filename: str) -> ctypes.CDLL:
+        cdll_mode = CDLL_MODE
+        if desc.requires_rtld_deepbind:
+            cdll_mode |= os.RTLD_DEEPBIND
+        return ctypes.CDLL(filename, cdll_mode)
+else:
+
+    def check_if_already_loaded_from_elsewhere(_desc: LibDescriptor, _have_abs_path: bool) -> LoadedDL | None:
+        raise RuntimeError(f"check_if_already_loaded_from_elsewhere() is not supported on platform {sys.platform!r}")
+
+    def _load_lib(_desc: LibDescriptor, _filename: str) -> ctypes.CDLL:
+        raise RuntimeError(f"_load_lib() is not supported on platform {sys.platform!r}")
 
 
 def load_with_system_search(desc: LibDescriptor) -> LoadedDL | None:

cuda_pathfinder/cuda/pathfinder/_dynamic_libs/load_dl_windows.py

@@ -1,4 +1,4 @@
-# SPDX-FileCopyrightText: Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-FileCopyrightText: Copyright (c) 2025-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 # SPDX-License-Identifier: Apache-2.0
 
 from __future__ import annotations
@@ -7,6 +7,7 @@
 import ctypes.wintypes
 import os
 import struct
+import sys
 import warnings
 from typing import TYPE_CHECKING
 
@@ -22,7 +23,10 @@
 POINTER_ADDRESS_SPACE = 2 ** (struct.calcsize("P") * 8)
 
 # Set up kernel32 functions with proper types
-kernel32 = ctypes.windll.kernel32  # type: ignore[attr-defined]
+windll = getattr(ctypes, "windll", None)
+if windll is None:
+    raise RuntimeError("ctypes.windll is required on Windows")
+kernel32 = windll.kernel32
 
 # GetModuleHandleW
 kernel32.GetModuleHandleW.argtypes = [ctypes.wintypes.LPCWSTR]
@@ -44,6 +48,14 @@
 ]
 kernel32.GetModuleFileNameW.restype = ctypes.wintypes.DWORD
 
+# AddDllDirectory (Windows 7+)
+kernel32.AddDllDirectory.argtypes = [ctypes.wintypes.LPCWSTR]
+kernel32.AddDllDirectory.restype = ctypes.c_void_p  # DLL_DIRECTORY_COOKIE
+
+# GetLastError
+kernel32.GetLastError.argtypes = []
+kernel32.GetLastError.restype = ctypes.wintypes.DWORD
+
 
 def ctypes_handle_to_unsigned_int(handle: ctypes.wintypes.HMODULE) -> int:
     """Convert ctypes HMODULE to unsigned int."""
@@ -73,7 +85,8 @@ def add_dll_directory(dll_abs_path: str) -> None:
     # the directory must stay on the search path for the process lifetime, and
     # the handle has no finalizer, so dropping it does not remove the directory.
     try:
-        os.add_dll_directory(dirpath)  # type: ignore[attr-defined]
+        if sys.platform == "win32":
+            os.add_dll_directory(dirpath)
     except OSError as e:
         # Warn instead of failing silently; the PATH update below is a weaker
         # fallback that newer loaders may ignore.
@@ -96,15 +109,15 @@ def abs_path_for_dynamic_library(libname: str, handle: ctypes.wintypes.HMODULE)
     length = kernel32.GetModuleFileNameW(handle, buffer, len(buffer))
 
     if length == 0:
-        error_code = ctypes.GetLastError()  # type: ignore[attr-defined]
+        error_code = kernel32.GetLastError()
         raise RuntimeError(f"GetModuleFileNameW failed for {libname!r} (error code: {error_code})")
 
     # If buffer was too small, try with larger buffer
     if length == len(buffer):
         buffer = ctypes.create_unicode_buffer(32768)  # Extended path length
         length = kernel32.GetModuleFileNameW(handle, buffer, len(buffer))
         if length == 0:
-            error_code = ctypes.GetLastError()  # type: ignore[attr-defined]
+            error_code = kernel32.GetLastError()
             raise RuntimeError(f"GetModuleFileNameW failed for {libname!r} (error code: {error_code})")
 
     return buffer.value
@@ -170,7 +183,7 @@ def load_with_abs_path(desc: LibDescriptor, found_path: str, found_via: str | No
     handle = kernel32.LoadLibraryExW(found_path, None, flags)
 
     if not handle:
-        error_code = ctypes.GetLastError()  # type: ignore[attr-defined]
+        error_code = kernel32.GetLastError()
         raise RuntimeError(f"Failed to load DLL at {found_path}: Windows error {error_code}")
 
     return LoadedDL(found_path, False, ctypes_handle_to_unsigned_int(handle), found_via)

cuda_pathfinder/cuda/pathfinder/_dynamic_libs/platform_loader.py

@@ -1,4 +1,4 @@
-# SPDX-FileCopyrightText: Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-FileCopyrightText: Copyright (c) 2025-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 # SPDX-License-Identifier: Apache-2.0
 
 """Platform loader seam for OS-specific dynamic linking.
@@ -16,11 +16,11 @@
 
 from __future__ import annotations
 
+import sys
 from typing import Protocol
 
 from cuda.pathfinder._dynamic_libs.lib_descriptor import LibDescriptor
 from cuda.pathfinder._dynamic_libs.load_dl_common import LoadedDL
-from cuda.pathfinder._utils.platform_aware import IS_WINDOWS
 
 
 class PlatformLoader(Protocol):
@@ -31,7 +31,7 @@ def load_with_system_search(self, desc: LibDescriptor) -> LoadedDL | None: ...
     def load_with_abs_path(self, desc: LibDescriptor, found_path: str, found_via: str | None = None) -> LoadedDL: ...
 
 
-if IS_WINDOWS:
+if sys.platform == "win32":
     from cuda.pathfinder._dynamic_libs import load_dl_windows as _impl
 else:
     from cuda.pathfinder._dynamic_libs import load_dl_linux as _impl

cuda_pathfinder/cuda/pathfinder/_utils/driver_info.py

@@ -5,13 +5,13 @@
 
 import ctypes
 import functools
+import sys
 from collections.abc import Callable
 from dataclasses import dataclass
 
 from cuda.pathfinder._dynamic_libs.load_nvidia_dynamic_lib import (
     load_nvidia_dynamic_lib as _load_nvidia_dynamic_lib,
 )
-from cuda.pathfinder._utils.platform_aware import IS_WINDOWS
 
 
 class QueryDriverCudaVersionError(RuntimeError):
@@ -60,16 +60,16 @@ def query_driver_cuda_version() -> DriverCudaVersion:
         raise QueryDriverCudaVersionError("Failed to query the CUDA driver version.") from exc
 
 
+if sys.platform == "win32":
+    _DRIVER_LIB_LOADER: Callable[[str], ctypes.CDLL] = ctypes.WinDLL
+else:
+    _DRIVER_LIB_LOADER = ctypes.CDLL
+
+
 def _query_driver_cuda_version_int() -> int:
     """Return the encoded CUDA driver version from ``cuDriverGetVersion()``."""
     loaded_cuda = _load_nvidia_dynamic_lib("cuda")
-    if IS_WINDOWS:
-        # `ctypes.WinDLL` exists on Windows at runtime. The ignore is only for
-        # Linux mypy runs, where the platform stubs do not define that attribute.
-        loader_cls: Callable[[str], ctypes.CDLL] = ctypes.WinDLL  # type: ignore[attr-defined]
-    else:
-        loader_cls = ctypes.CDLL
-    driver_lib = loader_cls(loaded_cuda.abs_path)
+    driver_lib = _DRIVER_LIB_LOADER(loaded_cuda.abs_path)
     cu_driver_get_version = driver_lib.cuDriverGetVersion
     cu_driver_get_version.argtypes = [ctypes.POINTER(ctypes.c_int)]
     cu_driver_get_version.restype = ctypes.c_int

cuda_pathfinder/tests/test_utils_driver_info.py

@@ -46,7 +46,6 @@ def test_query_driver_cuda_version_uses_windll_on_windows(monkeypatch):
     fake_driver_lib = _FakeDriverLib(status=0, version=12080)
     loaded_paths: list[str] = []
 
-    monkeypatch.setattr(driver_info, "IS_WINDOWS", True)
     monkeypatch.setattr(
         driver_info,
         "_load_nvidia_dynamic_lib",
@@ -57,7 +56,7 @@ def fake_windll(abs_path: str):
         loaded_paths.append(abs_path)
         return fake_driver_lib
 
-    monkeypatch.setattr(driver_info.ctypes, "WinDLL", fake_windll, raising=False)
+    monkeypatch.setattr(driver_info, "_DRIVER_LIB_LOADER", fake_windll)
 
     assert driver_info._query_driver_cuda_version_int() == 12080
     assert loaded_paths == [r"C:\Windows\System32\nvcuda.dll"]
@@ -93,9 +92,8 @@ def fail_query_driver_cuda_version_int() -> int:
 def test_query_driver_cuda_version_int_raises_when_cuda_call_fails(monkeypatch):
     fake_driver_lib = _FakeDriverLib(status=1, version=0)
 
-    monkeypatch.setattr(driver_info, "IS_WINDOWS", False)
     monkeypatch.setattr(driver_info, "_load_nvidia_dynamic_lib", lambda _libname: _loaded_cuda("/usr/lib/libcuda.so.1"))
-    monkeypatch.setattr(driver_info.ctypes, "CDLL", lambda _abs_path: fake_driver_lib)
+    monkeypatch.setattr(driver_info, "_DRIVER_LIB_LOADER", lambda _abs_path: fake_driver_lib)
 
     with pytest.raises(RuntimeError, match=r"cuDriverGetVersion\(\) \(status=1\)"):
         driver_info._query_driver_cuda_version_int()