Pass -ivfsoverlay windows-vfs-overlay.yaml to swift-ide-test only when testing for Windows host platform

Author: weliveindetail

test/lit.cfg

@@ -395,28 +395,6 @@ lit_config.note('Using resource dir: ' + test_resource_dir)
 test_clang_resource_dir = lit.util.executeCommand([config.clang, '-print-resource-dir'])[0].rstrip()
 lit_config.note('Using Clang resource dir: ' + test_clang_resource_dir)
 
-config.swift_system_overlay_opt = ""
-config.clang_system_overlay_opt = ""
-config.windows_vfs_overlay_opt = ""
-if kIsWindows:
-    # ucrt.modulemap currently requires -fbuiltin-headers-in-system-modules. -strict-implicit-module-context
-    # is necessary for -Xcc arguments to be passed through ModuleInterfaceLoader.
-    config.swift_system_overlay_opt = "-vfsoverlay {} -strict-implicit-module-context -Xcc -Xclang -Xcc -fbuiltin-headers-in-system-modules".format(
-        os.path.join(config.swift_obj_root, "stdlib", "windows-vfs-overlay.yaml")
-    )
-    # this variant is for extract-symbolgraph which doesn't accept all the same arugments as swiftc
-    # so the extra ceremony lets us pass in the relevant pieces needed for Windows SDK access.
-    config.windows_vfs_overlay_opt = "-Xcc -vfsoverlay -Xcc {} -Xcc -strict-implicit-module-context -Xcc -Xclang -Xcc -fbuiltin-headers-in-system-modules".format(
-        os.path.join(config.swift_obj_root, "stdlib", "windows-vfs-overlay.yaml")
-    )
-    config.clang_system_overlay_opt = "-Xcc -ivfsoverlay -Xcc {} -Xcc -Xclang -Xcc -fbuiltin-headers-in-system-modules".format(
-        os.path.join(config.swift_obj_root, "stdlib", "windows-vfs-overlay.yaml")
-    )
-config.substitutions.append( ('%windows_vfs_overlay_opt', config.windows_vfs_overlay_opt) )
-stdlib_resource_dir_opt = config.resource_dir_opt
-sourcekitd_framework_dir = config.swift_lib_dir
-config.substitutions.append( ('%test-resource-dir', test_resource_dir) )
-
 # Parse the variant triple.
 # FIXME: We ought to parse 'run_environment' separately from 'run_os'.
 (run_cpu, run_vendor, run_os, run_vers) = re.match('([^-]+)-([^-]+)-([^0-9]+)(.*)', config.variant_triple).groups()
@@ -479,6 +457,28 @@ if test_sdk_overlay_dir is not None:
     lit_config.note('Using SDK overlay dir: ' + test_sdk_overlay_dir)
     config.resource_dir_opt += (" %s" % sdk_overlay_dir_opt)
 
+config.swift_system_overlay_opt = ""
+config.clang_system_overlay_opt = ""
+config.windows_vfs_overlay_opt = ""
+if kIsWindows and run_os in ['windows-msvc']:
+    # ucrt.modulemap currently requires -fbuiltin-headers-in-system-modules. -strict-implicit-module-context
+    # is necessary for -Xcc arguments to be passed through ModuleInterfaceLoader.
+    config.swift_system_overlay_opt = "-vfsoverlay {} -strict-implicit-module-context -Xcc -Xclang -Xcc -fbuiltin-headers-in-system-modules".format(
+        os.path.join(config.swift_obj_root, "stdlib", "windows-vfs-overlay.yaml")
+    )
+    # this variant is for extract-symbolgraph which doesn't accept all the same arugments as swiftc
+    # so the extra ceremony lets us pass in the relevant pieces needed for Windows SDK access.
+    config.windows_vfs_overlay_opt = "-Xcc -vfsoverlay -Xcc {} -Xcc -strict-implicit-module-context -Xcc -Xclang -Xcc -fbuiltin-headers-in-system-modules".format(
+        os.path.join(config.swift_obj_root, "stdlib", "windows-vfs-overlay.yaml")
+    )
+    config.clang_system_overlay_opt = "-Xcc -ivfsoverlay -Xcc {} -Xcc -Xclang -Xcc -fbuiltin-headers-in-system-modules".format(
+        os.path.join(config.swift_obj_root, "stdlib", "windows-vfs-overlay.yaml")
+    )
+config.substitutions.append( ('%windows_vfs_overlay_opt', config.windows_vfs_overlay_opt) )
+stdlib_resource_dir_opt = config.resource_dir_opt
+sourcekitd_framework_dir = config.swift_lib_dir
+config.substitutions.append( ('%test-resource-dir', test_resource_dir) )
+
 # Default to Swift 4 for now.
 # Note that this accepts both `--param swift-version` (like the compiler flag)
 # and `--param swift_version` (like a lit configuration parameter).