build-script: Make --xcode imply --skip-build --skip-early-swift-driver

Author: AnthonyLatsis

utils/build_swift/build_swift/driver_arguments.py

@@ -122,6 +122,10 @@ def _apply_default_arguments(args):
     # Set the default CMake generator.
     if args.cmake_generator is None:
         args.cmake_generator = 'Ninja'
+    elif args.cmake_generator == 'Xcode':
+        # Building with Xcode is deprecated.
+        args.skip_build = True
+        args.build_early_swift_driver = False
 
     # --ios-all etc are not supported by open-source Swift.
     if args.ios_all:

utils/build_swift/tests/build_swift/test_driver_arguments.py

@@ -640,3 +640,9 @@ def test_implied_defaults_host_test(self):
     def test_implied_defaults_swift_disable_dead_stripping(self):
         namespace = self.parse_default_args(['--swift-disable-dead-stripping'])
         self.assertTrue(namespace.swift_disable_dead_stripping)
+
+    def test_implied_defaults_xcode(self):
+        namespace = self.parse_default_args(['--xcode'])
+        self.assertEqual(namespace.cmake_generator, 'Xcode')
+        self.assertTrue(namespace.skip_build)
+        self.assertFalse(namespace.build_early_swift_driver)