Support Windows on ARM64 (#268)

* Support Windows on ARM64

* Update workflow

* Fix type annotations

* Updated the docs for gcc requirements

* Fix platform for Windows

Author: billti

.github/workflows/main.yml

@@ -79,24 +79,14 @@ jobs:
         python setup.py bdist_wheel --plat-name win-amd64
     - run: |
         git clean -fdx wasmtime build
-        python ci/download-wasmtime.py musl x86_64
+        python ci/download-wasmtime.py win32 arm64
         python ci/build-rust.py
-        python setup.py bdist_wheel --plat-name musllinux_1_2_x86_64
-
-    # Build an "any" wheel with:
-    #
-    #   * MinGW
-    #
-    # because at this time I don't know what the `--plat-name` tags supported on
-    # PyPI are for these platforms. Our hope is that any platform not matching
-    # the above `--plat-name` arguments will install this `any` wheel instead,
-    # and then when the wheel runs it'll dynamically select from the available
-    # shared libraries.
+        python setup.py bdist_wheel --plat-name win-arm64
     - run: |
         git clean -fdx wasmtime build
-        python ci/download-wasmtime.py win32 x86_64
+        python ci/download-wasmtime.py musl x86_64
         python ci/build-rust.py
-        python setup.py bdist_wheel
+        python setup.py bdist_wheel --plat-name musllinux_1_2_x86_64
 
     - uses: actions/upload-artifact@v4
       with:

CONTRIBUTING.md

@@ -24,8 +24,9 @@ Otherwise if you have a local checkout of Wasmtime you can symlink its
 `libwasmtime.so` (or equivalent) to `wasmtime/linux-x86_64/_libwasmtime.so` (or
 equivalent).
 
-Next the bindings generation requires compiling some Rust code to WebAssembly,
-which can be done with:
+Next the bindings generation requires compiling some Rust code to WebAssembly.
+This requires the `wasip1` Rust target be installed (`rustup target add wasm32-wasip1`)
+as well as `wasm-tools` (`cargo install wasm-tools`), and then run:
 
 ```sh
 $ python ci/build-rust.py
@@ -39,6 +40,12 @@ $ pip install -e ".[testing]"
 
 ## Testing
 
+On Windows, the below will require `gcc` to be installed locally and on the PATH.
+The easiest way to do this is via an installer such as `https://github.com/msys2/msys2-installer/releases/download/2024-12-08/msys2-x86_64-20241208.exe`,
+and then in the MSYS2 terminal run the command `pacman -S --needed base-devel mingw-w64-ucrt-x86_64-toolchain` to install GCC. Put `C:\msys64\ucrt64\bin` (or
+wherever you installed GCC to) on the end of the PATH (if earlier on the PATH its
+version of Python may get picked up before the desired version).
+
 After you've completed the set up steps, you can run the tests locally with
 `pytest`:
 

README.md

@@ -27,8 +27,8 @@ To install `wasmtime-py`, run this command in your terminal:
 $ pip install wasmtime
 ```
 
-The package currently supports 64-bit builds of Python 3.9+ on x86\_64 Windows,
-macOS, and Linux, as well as on arm64 macOS and Linux.
+The package currently supports 64-bit builds of Python 3.9+ on Windows,
+macOS, and Linux, for x86\_64 and arm64 architectures.
 
 ## Versioning
 

ci/download-wasmtime.py

@@ -21,7 +21,7 @@ def main(platform, arch):
 
     if arch == 'AMD64':
         arch = 'x86_64'
-    if arch == 'arm64':
+    if arch == 'arm64' or arch == 'ARM64':
         arch = 'aarch64'
     dirname = '{}-{}'.format(platform, arch)
     if platform == 'linux' or platform == 'musl':

setup.py

@@ -42,7 +42,9 @@
             'pytest',
             'pycparser',
             'pytest-mypy',
-            'componentize-py',
+            # componentize-py only support x86_64 builds on Windows
+            # platform.machine() on Windows returns 'AMD64' for x86_64
+            "componentize-py; platform_system != 'Windows' or platform_machine == 'AMD64'",
         ],
     },
     classifiers=[

tests/bindgen/__init__.py

@@ -1,6 +1,9 @@
 import sys
 import pytest
+import platform
 
-# componentize-py requires Python 3.10
-if sys.version_info < (3, 10):
+is_win_arm64 = platform.system() == 'Windows' and platform.machine() == 'ARM64'
+
+# componentize-py requires Python 3.10, and doesn't support Windows on ARM64
+if sys.version_info < (3, 10) or is_win_arm64:
     pytest.skip("skipping componentize-py tests", allow_module_level=True)

wasmtime/_ffi.py

@@ -20,7 +20,7 @@
 machine = platform.machine()
 if machine == 'AMD64':
     machine = 'x86_64'
-if machine == 'arm64':
+if machine == 'arm64' or machine == 'ARM64':
     machine = 'aarch64'
 if machine != 'x86_64' and machine != 'aarch64':
     raise RuntimeError("unsupported architecture for wasmtime: {}".format(machine))

wasmtime/_func.py

@@ -185,8 +185,8 @@ def extract_val(val: Val) -> Any:
     return val
 
 
-@ffi.wasmtime_func_callback_t  # type: ignore
-def trampoline(idx, caller, params, nparams, results, nresults):
+@ffi.wasmtime_func_callback_t
+def trampoline(idx, caller, params, nparams, results, nresults):  # type: ignore
     caller = Caller(caller)
     try:
         func, result_tys, access_caller = FUNCTIONS.get(idx or 0)