Add support for building extensions using MinGW compilers

.github/workflows/main.yml

@@ -120,6 +120,48 @@ jobs:
         shell: C:\cygwin\bin\env.exe CYGWIN_NOWINPATH=1 CHERE_INVOKING=1 C:\cygwin\bin\bash.exe -leo pipefail -o igncr {0}
         run: tox
 
+  test_msys2_mingw:
+    strategy:
+      matrix:
+        include:
+          - { sys: mingw64, env: x86_64, cc: gcc, cxx: g++ }
+          - { sys: mingw32, env: i686, cc: gcc, cxx: g++ }
+          - { sys: ucrt64,  env: ucrt-x86_64, cc: gcc, cxx: g++ }
+          - { sys: clang64, env: clang-x86_64, cc: clang, cxx: clang++}
+    runs-on: windows-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: msys2/setup-msys2@v2
+        with:
+          msystem: ${{matrix.sys}}
+          install: |
+            mingw-w64-${{matrix.env}}-toolchain
+            mingw-w64-${{matrix.env}}-python
+            mingw-w64-${{matrix.env}}-python-pip
+            mingw-w64-${{matrix.env}}-python-virtualenv
+            mingw-w64-${{matrix.env}}-cc
+            git
+      - name: Install Dependencies
+        shell: msys2 {0}
+        run: |
+          export VIRTUALENV_NO_SETUPTOOLS=1
+
+          python -m virtualenv /tmp/venv
+          source /tmp/venv/bin/activate
+
+          # python-ruff doesn't work without rust
+          sed -i '/pytest-ruff/d' pyproject.toml
+
+          pip install -e .[test]
+      - name: Run tests
+        shell: msys2 {0}
+        env:
+          CC: ${{ matrix.cc }}
+          CXX: ${{ matrix.cxx }}
+        run: |
+          source /tmp/venv/bin/activate
+          pytest
+
   ci_setuptools:
     # Integration testing with setuptools
     strategy:

distutils/ccompiler.py

@@ -21,7 +21,7 @@
 )
 from .file_util import move_file
 from .spawn import spawn
-from .util import execute, split_quoted
+from .util import execute, split_quoted, is_mingw
 
 
 class CCompiler:
@@ -1075,6 +1075,10 @@ def get_default_compiler(osname=None, platform=None):
         osname = os.name
     if platform is None:
         platform = sys.platform
+    # Mingw is a special case where sys.platform is 'win32' but we
+    # want to use the 'mingw32' compiler, so check it first
+    if is_mingw():
+        return 'mingw32'
     for pattern, compiler in _default_compilers:
         if (
             re.match(pattern, platform) is not None

distutils/command/build_ext.py

@@ -23,7 +23,7 @@
 )
 from ..extension import Extension
 from ..sysconfig import customize_compiler, get_config_h_filename, get_python_version
-from ..util import get_platform
+from ..util import get_platform, is_mingw
 
 # An extension name is just a dot-separated list of Python NAMEs (ie.
 # the same as a fully-qualified module name).
@@ -212,7 +212,7 @@ def finalize_options(self):  # noqa: C901
         # for extensions under windows use different directories
         # for Release and Debug builds.
         # also Python's library directory must be appended to library_dirs
-        if os.name == 'nt':
+        if os.name == 'nt' and not is_mingw():
             # the 'libs' directory is for binary installs - we assume that
             # must be the *native* platform.  But we don't really support
             # cross-compiling via a binary install anyway, so we let it go.
@@ -754,7 +754,7 @@ def get_libraries(self, ext):  # noqa: C901
         # pyconfig.h that MSVC groks.  The other Windows compilers all seem
         # to need it mentioned explicitly, though, so that's what we do.
         # Append '_d' to the python import library on debug builds.
-        if sys.platform == "win32":
+        if sys.platform == "win32" and not is_mingw():
             from .._msvccompiler import MSVCCompiler
 
             if not isinstance(self.compiler, MSVCCompiler):
@@ -784,7 +784,7 @@ def get_libraries(self, ext):  # noqa: C901
                 # A native build on an Android device or on Cygwin
                 if hasattr(sys, 'getandroidapilevel'):
                     link_libpython = True
-                elif sys.platform == 'cygwin':
+                elif sys.platform == 'cygwin' or is_mingw():
                     link_libpython = True
                 elif '_PYTHON_HOST_PLATFORM' in os.environ:
                     # We are cross-compiling for one of the relevant platforms

distutils/cygwinccompiler.py

@@ -57,7 +57,7 @@ def get_msvcr():
     try:
         msc_ver = int(match.group(1))
     except AttributeError:
-        return
+        return []
     try:
         return _msvcr_lookup[msc_ver]
     except KeyError:
@@ -275,7 +275,7 @@ def __init__(self, verbose=False, dry_run=False, force=False):
 
         self.set_executables(
             compiler=f'{self.cc} -O -Wall',
-            compiler_so=f'{self.cc} -mdll -O -Wall',
+            compiler_so=f'{self.cc} -shared -O -Wall',
             compiler_cxx=f'{self.cxx} -O -Wall',
             linker_exe=f'{self.cc}',
             linker_so=f'{self.linker_dll} {shared_option}',

distutils/sysconfig.py

@@ -19,6 +19,7 @@
 from ._functools import pass_none
 from .compat import py39
 from .errors import DistutilsPlatformError
+from .util import is_mingw
 
 IS_PYPY = '__pypy__' in sys.builtin_module_names
 
@@ -121,8 +122,10 @@ def get_python_inc(plat_specific=False, prefix=None):
     """
     default_prefix = BASE_EXEC_PREFIX if plat_specific else BASE_PREFIX
     resolved_prefix = prefix if prefix is not None else default_prefix
+    # MinGW imitates posix like layout, but os.name != posix
+    os_name = "posix" if is_mingw() else os.name
     try:
-        getter = globals()[f'_get_python_inc_{os.name}']
+        getter = globals()[f'_get_python_inc_{os_name}']
     except KeyError:
         raise DistutilsPlatformError(
             "I don't know where Python installs its C header files "
@@ -244,7 +247,7 @@ def get_python_lib(plat_specific=False, standard_lib=False, prefix=None):
         else:
             prefix = plat_specific and EXEC_PREFIX or PREFIX
 
-    if os.name == "posix":
+    if os.name == "posix" or is_mingw():
         if plat_specific or standard_lib:
             # Platform-specific modules (any module from a non-pure-Python
             # module distribution) or standard Python library modules.
@@ -290,7 +293,7 @@ def customize_compiler(compiler):  # noqa: C901
     Mainly needed on Unix, so we can plug in the information that
     varies across Unices and is stored in Python's Makefile.
     """
-    if compiler.compiler_type == "unix":
+    if compiler.compiler_type in ["unix", "cygwin", "mingw32"]:
         _customize_macos()
 
         (

distutils/tests/test_cygwinccompiler.py

@@ -71,12 +71,12 @@ def test_check_config_h(self):
         assert check_config_h()[0] == CONFIG_H_OK
 
     def test_get_msvcr(self):
-        # none
+        # []
         sys.version = (
             '2.6.1 (r261:67515, Dec  6 2008, 16:42:21) '
             '\n[GCC 4.0.1 (Apple Computer, Inc. build 5370)]'
         )
-        assert get_msvcr() is None
+        assert get_msvcr() == []
 
         # MSVC 7.0
         sys.version = (
@@ -114,3 +114,10 @@ def test_get_msvcr(self):
         )
         with pytest.raises(ValueError):
             get_msvcr()
+
+    @pytest.mark.skipif('sys.platform != "cygwin"')
+    def test_dll_libraries_not_none(self):
+        from distutils.cygwinccompiler import CygwinCCompiler
+
+        compiler = CygwinCCompiler()
+        assert compiler.dll_libraries is not None

distutils/tests/test_install.py

@@ -13,6 +13,7 @@
 from distutils.errors import DistutilsOptionError
 from distutils.extension import Extension
 from distutils.tests import missing_compiler_executable, support
+from distutils.util import is_mingw
 
 import pytest
 
@@ -117,7 +118,7 @@ def _expanduser(path):
         assert 'usersite' in cmd.config_vars
 
         actual_headers = os.path.relpath(cmd.install_headers, site.USER_BASE)
-        if os.name == 'nt':
+        if os.name == 'nt' and not is_mingw():
             site_path = os.path.relpath(os.path.dirname(orig_site), orig_base)
             include = os.path.join(site_path, 'Include')
         else:

distutils/tests/test_mingwccompiler.py

@@ -0,0 +1,45 @@
+import pytest
+
+from distutils.util import split_quoted, is_mingw
+from distutils.errors import DistutilsPlatformError, CCompilerError
+
+
+class TestMingw32CCompiler:
+    @pytest.mark.skipif(not is_mingw(), reason='not on mingw')
+    def test_compiler_type(self):
+        from distutils.cygwinccompiler import Mingw32CCompiler
+
+        compiler = Mingw32CCompiler()
+        assert compiler.compiler_type == 'mingw32'
+
+    @pytest.mark.skipif(not is_mingw(), reason='not on mingw')
+    def test_set_executables(self, monkeypatch):
+        from distutils.cygwinccompiler import Mingw32CCompiler
+
+        monkeypatch.setenv('CC', 'cc')
+        monkeypatch.setenv('CXX', 'c++')
+
+        compiler = Mingw32CCompiler()
+
+        assert compiler.compiler == split_quoted('cc -O -Wall')
+        assert compiler.compiler_so == split_quoted('cc -shared -O -Wall')
+        assert compiler.compiler_cxx == split_quoted('c++ -O -Wall')
+        assert compiler.linker_exe == split_quoted('cc')
+        assert compiler.linker_so == split_quoted('cc -shared')
+
+    @pytest.mark.skipif(not is_mingw(), reason='not on mingw')
+    def test_runtime_library_dir_option(self):
+        from distutils.cygwinccompiler import Mingw32CCompiler
+
+        compiler = Mingw32CCompiler()
+        with pytest.raises(DistutilsPlatformError):
+            compiler.runtime_library_dir_option('/usr/lib')
+
+    @pytest.mark.skipif(not is_mingw(), reason='not on mingw')
+    def test_cygwincc_error(self, monkeypatch):
+        import distutils.cygwinccompiler
+
+        monkeypatch.setattr(distutils.cygwinccompiler, 'is_cygwincc', lambda _: True)
+
+        with pytest.raises(CCompilerError):
+            distutils.cygwinccompiler.Mingw32CCompiler()

distutils/tests/test_sysconfig.py

@@ -7,7 +7,7 @@
 import subprocess
 import sys
 from distutils import sysconfig
-from distutils.ccompiler import get_default_compiler  # noqa: F401
+from distutils.ccompiler import new_compiler  # noqa: F401
 from distutils.unixccompiler import UnixCCompiler
 from test.support import swap_item
 
@@ -110,7 +110,7 @@ def set_executables(self, **kw):
 
         return comp
 
-    @pytest.mark.skipif("get_default_compiler() != 'unix'")
+    @pytest.mark.skipif("not isinstance(new_compiler(), UnixCCompiler)")
     @pytest.mark.usefixtures('disable_macos_customization')
     def test_customize_compiler(self):
         # Make sure that sysconfig._config_vars is initialized

distutils/tests/test_util.py

@@ -108,6 +108,7 @@ def _join(*path):
 
         # windows
         os.name = 'nt'
+        os.sep = '\\'
 
         def _isabs(path):
             return path.startswith('c:\\')

distutils/util.py

@@ -159,7 +159,7 @@ def change_root(new_root, pathname):
 
     elif os.name == 'nt':
         (drive, path) = os.path.splitdrive(pathname)
-        if path[0] == '\\':
+        if path[0] == os.sep:
             path = path[1:]
         return os.path.join(new_root, path)
 
@@ -499,3 +499,12 @@ def rfc822_escape(header):
     suffix = indent if ends_in_newline else ""
 
     return indent.join(lines) + suffix
+
+
+def is_mingw():
+    """Returns True if the current platform is mingw.
+
+    Python compiled with Mingw-w64 has sys.platform == 'win32' and
+    get_platform() starts with 'mingw'.
+    """
+    return sys.platform == 'win32' and get_platform().startswith('mingw')