msvc compiler: Re-sort sources to compile Message Compiler files (.mc) first

distutils/compilers/C/msvc.py

@@ -18,7 +18,8 @@
 import subprocess
 import unittest.mock as mock
 import warnings
-from collections.abc import Iterable
+from collections.abc import Iterable, Sequence
+from pathlib import Path
 
 with contextlib.suppress(ImportError):
     import winreg
@@ -371,17 +372,24 @@ def out_extensions(self) -> dict[str, str]:
 
     def compile(  # noqa: C901
         self,
-        sources,
+        sources: Sequence[str | os.PathLike[str]],
         output_dir=None,
         macros=None,
         include_dirs=None,
         debug=False,
         extra_preargs=None,
         extra_postargs=None,
         depends=None,
-    ):
+    ) -> list[str]:
         if not self.initialized:
             self.initialize()
+
+        # Move .mc files to the start of the list, otherwise keep the same order
+        # See pypa/setuptools#4986
+        sources = sorted(
+            sources, key=lambda source: Path(source).suffix not in self._mc_extensions
+        )
+
         compile_info = self._setup_compile(
             output_dir, macros, include_dirs, sources, depends, extra_postargs
         )

distutils/compilers/C/tests/test_msvc.py

@@ -6,6 +6,7 @@
 from distutils.errors import DistutilsPlatformError
 from distutils.tests import support
 from distutils.util import get_platform
+from pathlib import Path
 
 import pytest
 
@@ -53,6 +54,23 @@ def _get_vcvars_spec(host_platform, platform):
         monkeypatch.setattr(msvc, '_get_vcvars_spec', _get_vcvars_spec)
         compiler.initialize(plat_name)
 
+    @pytest.mark.skipif(
+        not sysconfig.get_platform().startswith("win"),
+        reason="Only run test for non-mingw Windows platforms",
+    )
+    def test_sources_compilation_order(self, tmp_path: Path) -> None:
+        # We expect the the mc files to be compiled first, but otherwise keep the same order
+        test_sources = [tmp_path / file for file in ("b.cpp", "y.mc", "a.c", "z.mc")]
+        expected_objects = [
+            str(tmp_path / obj) for obj in ("y.res", "z.res", "b.obj", "a.obj")
+        ]
+        for source in test_sources:
+            source.write_text("")
+
+        compiler = msvc.Compiler()
+        objects = compiler.compile(test_sources)
+        assert objects == expected_objects
+
     @needs_winreg
     def test_get_vc_env_unicode(self):
         test_var = 'ṰḖṤṪ┅ṼẨṜ'