add support for macOS arm64, build wheels (#92)

* handle platform.machine() == arm64 for macOS

Upstream wasmtime releases use aarch64-macos as part of the file name.
On aarch64 macOS, platform.machine() returns 'arm64' instead.
With this change, download-wasmtime.py correctly downloads
aarch64-macos binaries and _ffi.py correctly loads them.

* ci: build wheels for macOS arm64

* setup.py: pin flake8 due to an incompatibility with pytest-flake8

pytest-flake8 is currently incompatible with 5.x flake8 releases.
This downgrades flake8 to an older version which still works.

Author: igrr

.github/workflows/main.yml

@@ -60,6 +60,10 @@ jobs:
         git clean -fdx wasmtime build
         python download-wasmtime.py darwin x86_64
         python setup.py bdist_wheel --plat-name macosx-10-13-x86_64
+    - run: |
+        git clean -fdx wasmtime build
+        python download-wasmtime.py darwin arm64
+        python setup.py bdist_wheel --plat-name macosx-11-0-arm64
     - run: |
         git clean -fdx wasmtime build
         python download-wasmtime.py win32 x86_64

download-wasmtime.py

@@ -17,6 +17,8 @@ def main(platform, arch):
         version = fh.read().strip()
     if arch == 'AMD64':
         arch = 'x86_64'
+    if arch == 'arm64':
+        arch = 'aarch64'
     if platform == 'linux':
         filename = 'wasmtime-v{}-{}-linux-c-api.tar.xz'.format(version, arch)
         libname = '_libwasmtime.so'

setup.py

@@ -39,6 +39,9 @@
     extras_require={
         'testing': [
             'coverage',
+            # remove flake8 once https://github.com/tholo/pytest-flake8/issues/87 is fixed
+            # and the new version of pytest-flake8 is released
+            'flake8==4.0.1',
             'pytest',
             'pycparser',
             'pytest-flake8',

wasmtime/_ffi.py

@@ -21,6 +21,8 @@
 machine = platform.machine()
 if machine == 'AMD64':
     machine = 'x86_64'
+if machine == 'arm64':
+    machine = 'aarch64'
 if machine != 'x86_64' and machine != 'aarch64':
     raise RuntimeError("unsupported architecture for wasmtime: {}".format(machine))