Script for making pyodide wheel

pyodide/setup.py

@@ -2,12 +2,16 @@
 # because `tool.setuptools.ext-modules` is still experimental in pyproject.toml
 # and we need it to get the wheel suffix right.
 import os
+import sys
 from pathlib import Path
 
 import tomllib
 from setuptools import Extension, find_packages, setup
+from setuptools.command.build_ext import build_ext
 
-REPO_FOLDER = Path(__file__).parent
+# Detect repo folder: if setup.py is in pyodide folder, go to parent
+SETUP_DIR = Path(__file__).parent
+REPO_FOLDER = SETUP_DIR.parent if SETUP_DIR.name == "pyodide" else SETUP_DIR
 
 
 def get_version() -> str:
@@ -24,6 +28,37 @@ def get_dependencies() -> list[str]:
     dependencies = pyproject_data["project"]["dependencies"]
     return dependencies
 
+class UnixBuildExt(build_ext):
+    """Customize ``build_ext`` to support packing on Windows."""
+    def finalize_options(self):
+        from distutils import sysconfig
+
+        super().finalize_options()
+        if sys.platform == 'win32':
+            self.compiler = 'unix'
+
+            # Configure sysconfig for Windows builds
+            # CCSHARED is the only variable that's not customizable with env vars.
+            # Basically avoiding this:
+            # File ".venv\Lib\site-packages\setuptools\_distutils\sysconfig.py", line 366, in customize_compiler
+            #     compiler_so=cc_cmd + ' ' + ccshared,
+            #                 ~~~~~~~~~~~~~^~~~~~~~~~
+            # TypeError: can only concatenate str (not "NoneType") to str
+            sysconfig.get_config_vars()  # Initialize config cache
+            if sysconfig._config_vars.get('CCSHARED') is None:
+                sysconfig._config_vars['CCSHARED'] = '-fPIC'
+            # Override compiler type before it's instantiated
+
+        # Set Emscripten compiler environment variables
+        os.environ['CC'] = 'emcc'
+        os.environ['CXX'] = 'em++'
+        os.environ['CFLAGS'] = ''
+        os.environ['CXXFLAGS'] = ''
+        os.environ['LDSHARED'] = 'emcc -shared'
+        os.environ['AR'] = 'emar'
+        os.environ['ARFLAGS'] = 'rcs'
+        os.environ['SETUPTOOLS_EXT_SUFFIX'] = '.cpython-313-wasm32-emscripten.so'
+
 
 setup(
     name="ifcopenshell",
@@ -44,4 +79,5 @@ setup(
     },
     # Has to provide extension to get the correct wheel suffix.
     ext_modules=[Extension("ifcopenshell._ifcopenshell_wrapper", sources=[])],
+    cmdclass={'build_ext': UnixBuildExt},
 )