bpo-35920: Windows 10 ARM32 platform support (GH-11774)

_msvccompiler.py

@@ -89,13 +89,24 @@ def _find_vc2017():
 
     return None, None
 
+PLAT_SPEC_TO_RUNTIME = {
+    'x86' : 'x86',
+    'x86_amd64' : 'x64',
+    'x86_arm' : 'arm',
+}
+
 def _find_vcvarsall(plat_spec):
     _, best_dir = _find_vc2017()
     vcruntime = None
+
+    if plat_spec in PLAT_SPEC_TO_RUNTIME:
+        vcruntime_plat = PLAT_SPEC_TO_RUNTIME[plat_spec]
+    else:
         vcruntime_plat = 'x64' if 'amd64' in plat_spec else 'x86'
+
     if best_dir:
         vcredist = os.path.join(best_dir, "..", "..", "redist", "MSVC", "**",
-            "Microsoft.VC141.CRT", "vcruntime140.dll")
+            vcruntime_plat, "Microsoft.VC141.CRT", "vcruntime140.dll")
         try:
             import glob
             vcruntime = glob.glob(vcredist, recursive=True)[-1]
@@ -178,6 +189,7 @@ def _find_exe(exe, paths=None):
 PLAT_TO_VCVARS = {
     'win32' : 'x86',
     'win-amd64' : 'x86_amd64',
+    'win-arm32' : 'x86_arm',
 }
 
 # A set containing the DLLs that are guaranteed to be available for

spawn.py

@@ -81,7 +81,6 @@ def _spawn_nt(cmd, search_path=1, verbose=0, dry_run=0):
                   "command %r failed with exit status %d" % (cmd, rc))
 
 if sys.platform == 'darwin':
-    from distutils import sysconfig
     _cfg_target = None
     _cfg_target_split = None
 
@@ -95,6 +94,7 @@ def _spawn_posix(cmd, search_path=1, verbose=0, dry_run=0):
     if sys.platform == 'darwin':
         global _cfg_target, _cfg_target_split
         if _cfg_target is None:
+            from distutils import sysconfig
             _cfg_target = sysconfig.get_config_var(
                                   'MACOSX_DEPLOYMENT_TARGET') or ''
             if _cfg_target:

sysconfig.py

@@ -15,6 +15,7 @@ import re
 import sys
 
 from .errors import DistutilsPlatformError
+from .util import get_platform, get_host_platform
 
 # These are needed in a couple of spots, so just compute them once.
 PREFIX = os.path.normpath(sys.prefix)

util.py

@@ -15,7 +15,7 @@ from distutils.spawn import spawn
 from distutils import log
 from distutils.errors import DistutilsByteCompileError
 
-def get_platform ():
+def get_host_platform():
     """Return a string that identifies the current platform.  This is used mainly to
     distinguish platform-specific build directories and platform-specific built
     distributions.  Typically includes the OS name and version and the
@@ -38,6 +38,8 @@ def get_platform ():
     if os.name == 'nt':
         if 'amd64' in sys.version.lower():
             return 'win-amd64'
+        if '(arm)' in sys.version.lower():
+            return 'win-arm32'
         return sys.platform
 
     # Set for cross builds explicitly
@@ -90,8 +92,16 @@ def get_platform ():
 
     return "%s-%s-%s" % (osname, release, machine)
 
-# get_platform ()
-
+def get_platform():
+    if os.name == 'nt':
+        TARGET_TO_PLAT = {
+            'x86' : 'win32',
+            'x64' : 'win-amd64',
+            'arm' : 'win-arm32',
+        }
+        return TARGET_TO_PLAT.get(os.environ.get('VSCMD_ARG_TGT_ARCH')) or get_host_platform()
+    else:
+        return get_host_platform()
 
 def convert_path (pathname):
     """Return 'pathname' as a name that will work on the native filesystem,