Build and test on Windows (MSYS2 CLANG64)

.github/workflows/tests.yml

@@ -4,10 +4,30 @@ on: [push, pull_request]
 
 jobs:
   test:
+    name: test (${{ matrix.os }})
+    runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        os: [ubuntu-latest, macos-latest]
-    runs-on: ${{ matrix.os }}
+        include:
+          - os: ubuntu-latest
+          - os: macos-latest
+          - os: windows-latest
+            shell: msys2 {0}
+    defaults:
+      run:
+        shell: ${{ matrix.shell || 'bash -e {0}' }}
     steps:
+    - name: Keep LF line endings
+      if: runner.os == 'Windows'
+      shell: pwsh
+      run: git config --global core.autocrlf false
     - uses: actions/checkout@v7
+    - uses: msys2/setup-msys2@v2
+      if: runner.os == 'Windows'
+      with:
+        msystem: CLANG64
+        path-type: inherit  # uv and Git for Windows stay visible
+        install: mingw-w64-clang-x86_64-clang mingw-w64-clang-x86_64-dlfcn  # clang for scons, dlopen for the filters
+    - uses: astral-sh/setup-uv@v5
+      if: runner.os == 'Windows'
     - run: ./test.sh

SConstruct

@@ -1,10 +1,12 @@
 import os
 import platform
 import subprocess
+import sys
 import sysconfig
 import numpy as np
 import eigen
 
+WINDOWS = platform.system() == "Windows"
 arch = subprocess.check_output(["uname", "-m"], encoding='utf8').rstrip()
 
 common = ''
@@ -38,7 +40,9 @@ env = Environment(
   CXXFLAGS="-std=c++1z",
   CPPPATH=cpppath,
   REDNOSE_ROOT=Dir("#").abspath,
-  tools=["default", "cython", "rednose_filter"],
+  tools=["mingw" if WINDOWS else "default", "cython", "rednose_filter"],  # the default tool picks MSVC on Windows
+  # the mingw tool assumes gcc and drops the lib prefix ekf_load expects; static libc++ so the DLLs load outside the MSYS2 shell
+  **({"CC": "clang", "CXX": "clang++", "SHLIBPREFIX": "lib", "LINKFLAGS": ["-static"]} if WINDOWS else {}),
 )
 
 # Cython build enviroment
@@ -48,6 +52,14 @@ envCython["CCFLAGS"] += ["-Wno-#warnings", "-Wno-cpp", "-Wno-shadow", "-Wno-depr
 envCython["LIBS"] = []
 if platform.system() == "Darwin":
   envCython["LINKFLAGS"] = ["-bundle", "-undefined", "dynamic_lookup"]
+elif WINDOWS:
+  envCython["LINKFLAGS"] = ["-shared", "-static"]
+  envCython["LIBPATH"] = [os.path.join(sys.base_prefix, "libs")]
+  envCython["LIBS"] = [f"python{sys.version_info.major}{sys.version_info.minor}"]
+  # extension modules are .pyd on Windows; the SConscript names them .so
+  def _pyd_emitter(target, source, env):
+    return [env.File(str(t)[:-3] + ".pyd") if str(t).endswith(".so") else t for t in target], source
+  envCython.Append(PROGEMITTER=[_pyd_emitter])
 elif arch == "aarch64":
   envCython["LINKFLAGS"] = ["-shared"]
   envCython["LIBS"] = [os.path.basename(python_path)]

rednose/helpers/__init__.py

@@ -16,7 +16,7 @@ def write_code(folder, name, code, header):
 
 
 def load_code(folder, name):
-  shared_ext = "dylib" if platform.system() == "Darwin" else "so"
+  shared_ext = {"Darwin": "dylib", "Windows": "dll"}.get(platform.system(), "so")
   shared_fn = os.path.join(folder, f"lib{name}.{shared_ext}")
   header_fn = os.path.join(folder, f"{name}.h")
 

site_scons/site_tools/rednose_filter.py

@@ -1,4 +1,5 @@
 import platform
+import sys
 
 import eigen
 from SCons.Script import Dir, File
@@ -9,8 +10,10 @@ def compile_single_filter(env, target, filter_gen_script, output_dir, extra_gen_
   extra_generated_files = [File(f'{output_dir}/{x}') for x in extra_gen_artifacts]
   generator_file = File(filter_gen_script)
 
+  # SCons runs commands through cmd.exe on Windows, which cannot start a script by its shebang
+  python = f'"{sys.executable}" ' if platform.system() == "Windows" else ""
   env.Command(generated_src_files + extra_generated_files,
-              [generator_file] + script_deps, f"{File(generator_file).relpath} {target} {Dir(output_dir).relpath}")
+              [generator_file] + script_deps, f"{python}{File(generator_file).relpath} {target} {Dir(output_dir).relpath}")
 
   generated_cc_file = File(generated_src_files[:1])