Add support for building extensions using MinGW compilers

distutils/ccompiler.py

@@ -19,7 +19,7 @@
 from .file_util import move_file
 from .dir_util import mkpath
 from ._modified import newer_group
-from .util import split_quoted, execute
+from .util import split_quoted, execute, is_mingw
 from ._log import log
 
 
@@ -1076,6 +1076,10 @@ 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

@@ -21,7 +21,7 @@
 from ..sysconfig import get_config_h_filename
 from .._modified import newer_group
 from ..extension import Extension
-from ..util import get_platform
+from ..util import get_platform, is_mingw
 from distutils._log import log
 from . import py37compat
 
@@ -189,7 +189,7 @@ 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.
@@ -742,7 +742,7 @@ 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):
@@ -772,7 +772,7 @@ 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:
@@ -277,7 +277,7 @@ def __init__(self, verbose=0, dry_run=0, force=0):
 
         self.set_executables(
             compiler='%s -O -Wall' % self.cc,
-            compiler_so='%s -mdll -O -Wall' % self.cc,
+            compiler_so='%s -shared -O -Wall' % self.cc,
             compiler_cxx='%s -O -Wall' % self.cxx,
             linker_exe='%s' % self.cc,
             linker_so='{} {}'.format(self.linker_dll, shared_option),

distutils/sysconfig.py

@@ -18,6 +18,7 @@
 from .errors import DistutilsPlatformError
 from . import py39compat
 from ._functools import pass_none
+from .util import is_mingw
 
 IS_PYPY = '__pypy__' in sys.builtin_module_names
 
@@ -120,8 +121,10 @@ def get_python_inc(plat_specific=0, 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=0, standard_lib=0, 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.
@@ -273,7 +276,7 @@ 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"]:
         if sys.platform == "darwin":
             # Perform first-time customization of compiler-related
             # config vars on OS X now that we know we need a compiler.

distutils/util.py

@@ -517,3 +517,12 @@ 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')