Finished ILanguageExceptionErrorInfo impl and usage

InteropTests/Tests/ErrorTests.swift

@@ -47,8 +47,6 @@ class ErrorTests: WinRTTestCase {
     }
 
     func testSwiftErrorPreserved() throws {
-        try XCTSkipIf(true, "TODO(#248): Fix preserving Swift error objects across the WinRT boundary.")
-
         struct SwiftError: Error {}
         do {
             try Errors.call { throw SwiftError() }

Support/Sources/WindowsRuntime/ProjectedTypes/Core/IActivationFactory.swift

@@ -1,11 +1,12 @@
 import COM
-import WindowsRuntime_ABI
 
 public typealias IActivationFactory = any IActivationFactoryProtocol
 public protocol IActivationFactoryProtocol: IInspectableProtocol {
     func activateInstance() throws -> IInspectable
 }
 
+import WindowsRuntime_ABI
+
 public enum IActivationFactoryProjection: InterfaceProjection {
     public typealias SwiftObject = IActivationFactory
     public typealias ABIStruct = WindowsRuntime_ABI.SWRT_IActivationFactory

Support/Sources/WindowsRuntime/ProjectedTypes/Core/IInspectable.swift

@@ -1,5 +1,4 @@
 import COM
-import WindowsRuntime_ABI
 
 public typealias IInspectable = any IInspectableProtocol
 public protocol IInspectableProtocol: IUnknownProtocol {
@@ -8,6 +7,8 @@ public protocol IInspectableProtocol: IUnknownProtocol {
     func getTrustLevel() throws -> TrustLevel
 }
 
+import WindowsRuntime_ABI
+
 public enum IInspectableProjection: InterfaceProjection {
     public typealias SwiftObject = IInspectable
     public typealias ABIStruct = WindowsRuntime_ABI.SWRT_IInspectable

Support/Sources/WindowsRuntime/ProjectedTypes/Core/ILanguageExceptionErrorInfo.swift

@@ -1,10 +1,12 @@
-import WindowsRuntime_ABI
+import COM
 
 public typealias ILanguageExceptionErrorInfo = any ILanguageExceptionErrorInfoProtocol
 public protocol ILanguageExceptionErrorInfoProtocol: IUnknownProtocol {
     var languageException: IUnknown { get throws }
 }
 
+import WindowsRuntime_ABI
+
 public enum ILanguageExceptionErrorInfoProjection: COMTwoWayProjection {
     public typealias ABIStruct = WindowsRuntime_ABI.SWRT_ILanguageExceptionErrorInfo
     public typealias SwiftObject = ILanguageExceptionErrorInfo
@@ -30,18 +32,19 @@ public enum ILanguageExceptionErrorInfoProjection: COMTwoWayProjection {
         QueryInterface: { IUnknownVirtualTable.QueryInterface($0, $1, $2) },
         AddRef: { IUnknownVirtualTable.AddRef($0) },
         Release: { IUnknownVirtualTable.Release($0) },
-        GetLanguageException: { this, languageException in _implement(this) {
-            TODO;
+        GetLanguageException: { this, languageException in _implement(this) { this in
+            guard let languageException else { throw COMError.fail }
+            languageException.pointee = try IUnknownProjection.toABI(this.languageException)
         } })
 }
 
 public func uuidof(_: WindowsRuntime_ABI.SWRT_ILanguageExceptionErrorInfo.Type) -> COMInterfaceID {
-    .init(TODO)
+    .init(0x04a2dbf3, 0xdf83, 0x116c, 0x0946, 0x0812abf6e07d)
 }
 
 extension COMInterop where ABIStruct == WindowsRuntime_ABI.SWRT_ILanguageExceptionErrorInfo {
-    public func getLanguageException() throws -> IUnkown {
-        var result: IUnknownProjection.abiDefaultValue
+    public func getLanguageException() throws -> IUnknown {
+        var result: IUnknownPointer? = nil // IUnknownProjection.abiDefaultValue (compiler bug?)
         defer { IUnknownProjection.release(&result) }
         try COMError.fromABI(this.pointee.VirtualTable.pointee.GetLanguageException(this, &result))
         return try NullResult.unwrap(IUnknownProjection.toSwift(consuming: &result))

Support/Sources/WindowsRuntime/ProjectedTypes/Core/IRestrictedErrorInfo.swift

@@ -1,4 +1,4 @@
-import WindowsRuntime_ABI
+import COM
 
 public typealias IRestrictedErrorInfo = any IRestrictedErrorInfoProtocol
 public protocol IRestrictedErrorInfoProtocol: IUnknownProtocol {
@@ -10,6 +10,8 @@ public protocol IRestrictedErrorInfoProtocol: IUnknownProtocol {
     var reference: String? { get throws }
 }
 
+import WindowsRuntime_ABI
+
 public enum IRestrictedErrorInfoProjection: COMTwoWayProjection {
     public typealias SwiftObject = IRestrictedErrorInfo
     public typealias ABIStruct = WindowsRuntime_ABI.SWRT_IRestrictedErrorInfo

Support/Sources/WindowsRuntime/ProjectedTypes/Core/IWeakReference.swift

@@ -1,10 +1,12 @@
-import WindowsRuntime_ABI
+import COM
 
 public typealias IWeakReference = any IWeakReferenceProtocol
 public protocol IWeakReferenceProtocol: IUnknownProtocol {
     func resolve() throws -> IInspectable?
 }
 
+import WindowsRuntime_ABI
+
 public enum IWeakReferenceProjection: COMTwoWayProjection {
     public typealias SwiftObject = IWeakReference
     public typealias ABIStruct = WindowsRuntime_ABI.SWRT_IWeakReference

Support/Sources/WindowsRuntime/ProjectedTypes/Core/IWeakReferenceSource.swift

@@ -1,10 +1,12 @@
-import WindowsRuntime_ABI
+import COM
 
 public typealias IWeakReferenceSource = any IWeakReferenceSourceProtocol
 public protocol IWeakReferenceSourceProtocol: IUnknownProtocol {
     func getWeakReference() throws -> IWeakReference
 }
 
+import WindowsRuntime_ABI
+
 public enum IWeakReferenceSourceProjection: COMTwoWayProjection {
     public typealias SwiftObject = IWeakReferenceSource
     public typealias ABIStruct = WindowsRuntime_ABI.SWRT_IWeakReferenceSource

Support/Sources/WindowsRuntime/WinRTError.swift

@@ -45,7 +45,7 @@ public struct WinRTError: COMErrorProtocol, CustomStringConvertible {
         guard let restrictedErrorInfo else { throw WinRTError(hresult: hresult) }
 
         if let languageExceptionErrorInfo = try? restrictedErrorInfo.queryInterface(ILanguageExceptionErrorInfoProjection.self) {
-            if let languageException = try? languageExceptionErrorInfo.getLanguageException() as? LanguageException {
+            if let languageException = try? languageExceptionErrorInfo.languageException as? LanguageException {
                 throw languageException.error
             }
         }
@@ -111,7 +111,7 @@ public struct WinRTError: COMErrorProtocol, CustomStringConvertible {
         SWRT_RoFailFastWithErrorContext(hresult.value)
     }
 
-    public static func createRestrictedErrorInfo(hresult: HResult, message: String?, languageException: IUnknown?) throws -> IRestrictedErrorInfo {
+    public static func createRestrictedErrorInfo(hresult: HResult, message: String?, languageException: IUnknown? = nil) throws -> IRestrictedErrorInfo {
         // Ro*** APIs expect an IRestrictedErrorInfo created from Ro*** APIs, we can't implement our own.
         // The only way we have to create one is RoOriginate***, which overwrites the current error info.
         // So we need to artificially preserve it.

Support/Sources/WindowsRuntime_ABI/include/SWRT/windows/restrictederrorinfo.h

@@ -3,6 +3,17 @@
 #include "SWRT/windows/oleauto.h"
 #include "SWRT/windows/unknwn.h"
 
+typedef struct SWRT_ILanguageExceptionErrorInfo {
+    struct SWRT_ILanguageExceptionErrorInfo_VirtualTable* VirtualTable;
+} SWRT_ILanguageExceptionErrorInfo;
+
+struct SWRT_ILanguageExceptionErrorInfo_VirtualTable {
+    SWRT_HResult (__stdcall *QueryInterface)(SWRT_ILanguageExceptionErrorInfo* _this, SWRT_Guid* riid, void** ppvObject);
+    uint32_t (__stdcall *AddRef)(SWRT_ILanguageExceptionErrorInfo* _this);
+    uint32_t (__stdcall *Release)(SWRT_ILanguageExceptionErrorInfo* _this);
+    SWRT_HResult (__stdcall *GetLanguageException)(SWRT_ILanguageExceptionErrorInfo* _this, SWRT_IUnknown** languageException);
+};
+
 typedef struct SWRT_IRestrictedErrorInfo {
     struct SWRT_IRestrictedErrorInfo_VirtualTable* VirtualTable;
 } SWRT_IRestrictedErrorInfo;