[jextract/jni] Bridge UUID

Samples/SwiftJavaExtractJNISampleApp/Sources/MySwiftLibrary/UUID.swift

@@ -0,0 +1,28 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2025 Apple Inc. and the Swift.org project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.txt for the list of Swift.org project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+
+#if canImport(FoundationEssentials)
+import FoundationEssentials
+#else
+import Foundation
+#endif
+import SwiftJava
+
+public func echoUUID(_ uuid: UUID) -> UUID {
+  return uuid
+}
+
+public func makeUUID() -> UUID {
+  return UUID()
+}

Samples/SwiftJavaExtractJNISampleApp/src/test/java/com/example/swift/UUIDTest.java

@@ -0,0 +1,38 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2025 Apple Inc. and the Swift.org project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.txt for the list of Swift.org project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+
+package com.example.swift;
+
+import org.junit.jupiter.api.Test;
+import org.swift.swiftkit.core.SwiftArena;
+
+import java.time.Instant;
+import java.time.temporal.ChronoUnit;
+import java.util.UUID;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+public class UUIDTest {
+    @Test
+    void echoUUID() {
+        var uuid = UUID.randomUUID();
+        assertEquals(uuid, MySwiftLibrary.echoUUID(uuid));
+    }
+
+    @Test
+    void makeUUID() {
+        var uuid = MySwiftLibrary.makeUUID();
+        assertEquals(4, uuid.version());
+    }
+}

Sources/JExtractSwiftLib/FFM/CDeclLowering/CRepresentation.swift

@@ -129,7 +129,7 @@ extension SwiftKnownTypeDeclKind {
     case .void: .void
     case .unsafePointer, .unsafeMutablePointer, .unsafeRawBufferPointer, .unsafeMutableRawBufferPointer, 
       .unsafeBufferPointer, .unsafeMutableBufferPointer, .string, .foundationData, .foundationDataProtocol, 
-      .essentialsData, .essentialsDataProtocol, .optional, .foundationDate, .essentialsDate:
+      .essentialsData, .essentialsDataProtocol, .optional, .foundationDate, .essentialsDate, .foundationUUID, .essentialsUUID:
        nil
     }
   }

Sources/JExtractSwiftLib/JNI/JNIJavaTypeTranslator.swift

@@ -45,7 +45,7 @@ enum JNIJavaTypeTranslator {
         .unsafePointer, .unsafeMutablePointer,
         .unsafeRawBufferPointer, .unsafeMutableRawBufferPointer,
         .unsafeBufferPointer, .unsafeMutableBufferPointer,
-        .optional, .foundationData, .foundationDataProtocol, .essentialsData, .essentialsDataProtocol, .array, .foundationDate, .essentialsDate:
+        .optional, .foundationData, .foundationDataProtocol, .essentialsData, .essentialsDataProtocol, .array, .foundationDate, .essentialsDate, .foundationUUID, .essentialsUUID:
       return nil
     }
   }
@@ -62,7 +62,7 @@ enum JNIJavaTypeTranslator {
       .unsafeRawBufferPointer, .unsafeMutableRawBufferPointer,
       .unsafeBufferPointer, .unsafeMutableBufferPointer,
       .optional, .foundationData, .foundationDataProtocol, .essentialsData, .essentialsDataProtocol,
-      .array, .foundationDate, .essentialsDate:
+      .array, .foundationDate, .essentialsDate, .foundationUUID, .essentialsUUID:
       nil
     }
   }
@@ -79,7 +79,7 @@ enum JNIJavaTypeTranslator {
       .unsafeRawBufferPointer, .unsafeMutableRawBufferPointer,
       .unsafeBufferPointer, .unsafeMutableBufferPointer,
       .optional, .foundationData, .foundationDataProtocol, .essentialsData, .essentialsDataProtocol,
-      .array, .foundationDate, .essentialsDate:
+      .array, .foundationDate, .essentialsDate, .foundationUUID, .essentialsUUID:
       nil
     }
   }

Sources/JExtractSwiftLib/JNI/JNISwift2JavaGenerator+JavaTranslation.swift

@@ -409,6 +409,12 @@ extension JNISwift2JavaGenerator {
             // Handled as wrapped struct
             break
 
+          case .foundationUUID, .essentialsUUID:
+            return TranslatedParameter(
+              parameter: JavaParameter(name: parameterName, type: .javaUtilUUID),
+              conversion: .method(.placeholder, function: "toString")
+            )
+
           default:
             guard let javaType = JNIJavaTypeTranslator.translate(knownType: knownType, config: self.config) else {
               throw JavaTranslationError.unsupportedSwiftType(swiftType)
@@ -695,6 +701,17 @@ extension JNISwift2JavaGenerator {
             // Handled as wrapped struct
             break
 
+          case .foundationUUID, .essentialsUUID:
+            return TranslatedResult(
+              javaType: .javaUtilUUID,
+              outParameters: [],
+              conversion: .method(
+                .constant("java.util.UUID"),
+                function: "fromString",
+                arguments: [.placeholder]
+              )
+            )
+
           default:
             guard let javaType = JNIJavaTypeTranslator.translate(knownType: knownType, config: self.config) else {
               throw JavaTranslationError.unsupportedSwiftType(swiftType)

Sources/JExtractSwiftLib/JNI/JNISwift2JavaGenerator+NativeTranslation.swift

@@ -102,6 +102,33 @@ extension JNISwift2JavaGenerator {
             // Handled as wrapped struct
             break
 
+          case .foundationUUID, .essentialsUUID:
+            let uuidStringVariable = "\(parameterName)_string$"
+            let initUUIDStep = NativeSwiftConversionStep.unwrapOptional(
+              .method(
+                .constant("UUID"),
+                function: "init",
+                arguments: [("uuidString", .placeholder)]
+              ),
+              name: parameterName,
+              fatalErrorMessage: "Invalid UUID string passed from Java: \\(\(uuidStringVariable))"
+            )
+
+            return NativeParameter(
+              parameters: [
+                JavaParameter(name: parameterName, type: .javaLangString)
+              ],
+              conversion: .replacingPlaceholder(
+                .aggregate(
+                  variable: uuidStringVariable,
+                  [initUUIDStep]
+                ),
+                placeholder: .initFromJNI(.placeholder, swiftType: self.knownTypes.string)
+              ),
+              indirectConversion: nil,
+              conversionCheck: nil
+            )
+
           default:
             guard let javaType = JNIJavaTypeTranslator.translate(knownType: knownType, config: self.config),
                   javaType.implementsJavaValue else {
@@ -515,6 +542,13 @@ extension JNISwift2JavaGenerator {
             // Handled as wrapped struct
             break
 
+          case .foundationUUID, .essentialsUUID:
+            return NativeResult(
+              javaType: .javaLangString,
+              conversion: .getJNIValue(.member(.placeholder, member: "uuidString")),
+              outParameters: []
+            )
+
           default:
             guard let javaType = JNIJavaTypeTranslator.translate(knownType: knownType, config: self.config), javaType.implementsJavaValue else {
               throw JavaTranslationError.unsupportedSwiftType(swiftResult.type)
@@ -766,6 +800,10 @@ extension JNISwift2JavaGenerator {
 
     indirect case labelessAssignmentOfVariable(NativeSwiftConversionStep, swiftType: SwiftType)
 
+    indirect case aggregate(variable: String, [NativeSwiftConversionStep])
+
+    indirect case replacingPlaceholder(NativeSwiftConversionStep, placeholder: NativeSwiftConversionStep)
+
     /// Returns the conversion string applied to the placeholder.
     func render(_ printer: inout CodePrinter, _ placeholder: String) -> String {
       // NOTE: 'printer' is used if the conversion wants to cause side-effects.
@@ -1166,8 +1204,21 @@ extension JNISwift2JavaGenerator {
           }
         }
         return printer.finalize()
+
       case .labelessAssignmentOfVariable(let name, let swiftType):
         return "\(swiftType)(\(JNISwift2JavaGenerator.indirectVariableName(for: name.render(&printer, placeholder))))"
+
+      case .aggregate(let variable, let steps):
+        precondition(!steps.isEmpty, "Aggregate must contain steps")
+        printer.print("let \(variable) = \(placeholder)")
+        let steps = steps.map {
+          $0.render(&printer, variable)
+        }
+        return steps.last!
+
+      case .replacingPlaceholder(let inner, let newPlaceholder):
+        let newPlaceholder = newPlaceholder.render(&printer, placeholder)
+        return inner.render(&printer, newPlaceholder)
       }
     }
   }

Sources/JExtractSwiftLib/JavaTypes/JavaType+JDK.swift

@@ -55,4 +55,8 @@ extension JavaType {
   static func future(_ T: JavaType) -> JavaType {
     .class(package: "java.util.concurrent", name: "Future", typeParameters: [T.boxedType])
   }
+
+  static var javaUtilUUID: JavaType {
+    .class(package: "java.util", name: "UUID")
+  }
 }

Sources/JExtractSwiftLib/SwiftTypes/SwiftKnownModules.swift

@@ -121,6 +121,8 @@ private let foundationEssentialsSourceFile: SourceFileSyntax = """
     /// Returns a `Date` initialized relative to 00:00:00 UTC on 1 January 1970 by a given number of seconds.
     public init(timeIntervalSince1970: Double)
   }
+
+  public struct UUID {}
   """
 
 private var foundationSourceFile: SourceFileSyntax {

Sources/JExtractSwiftLib/SwiftTypes/SwiftKnownTypeDecls.swift

@@ -49,6 +49,8 @@ enum SwiftKnownTypeDeclKind: String, Hashable {
   case essentialsData = "FoundationEssentials.Data"
   case foundationDate = "Foundation.Date"
   case essentialsDate = "FoundationEssentials.Date"
+  case foundationUUID = "Foundation.UUID"
+  case essentialsUUID = "FoundationEssentials.UUID"
 
   var moduleAndName: (module: String, name: String) {
     let qualified = self.rawValue

Sources/JExtractSwiftLib/SwiftTypes/SwiftKnownTypes.swift

@@ -35,12 +35,15 @@ struct SwiftKnownTypes {
   var unsafeRawPointer: SwiftType { .nominal(SwiftNominalType(nominalTypeDecl: symbolTable[.unsafeRawPointer])) }
   var unsafeRawBufferPointer: SwiftType { .nominal(SwiftNominalType(nominalTypeDecl: symbolTable[.unsafeRawBufferPointer])) }
   var unsafeMutableRawPointer: SwiftType { .nominal(SwiftNominalType(nominalTypeDecl: symbolTable[.unsafeMutableRawPointer])) }
-
+  var string: SwiftType { .nominal(SwiftNominalType(nominalTypeDecl: symbolTable[.string])) }
+
   var foundationDataProtocol: SwiftType { .nominal(SwiftNominalType(nominalTypeDecl: symbolTable[.foundationDataProtocol])) }
   var foundationData: SwiftType { .nominal(SwiftNominalType(nominalTypeDecl: symbolTable[.foundationData])) }
   var essentialsDataProtocol: SwiftType { .nominal(SwiftNominalType(nominalTypeDecl: symbolTable[.essentialsDataProtocol])) }
   var essentialsData: SwiftType { .nominal(SwiftNominalType(nominalTypeDecl: symbolTable[.essentialsData])) }
-
+  var foundationUUID: SwiftType { .nominal(SwiftNominalType(nominalTypeDecl: symbolTable[.foundationUUID])) }
+  var essentialsUUID: SwiftType { .nominal(SwiftNominalType(nominalTypeDecl: symbolTable[.essentialsUUID]))}
+
   /// `(UnsafeRawPointer, Long) -> ()` function type.
   /// 
   /// Commonly used to initialize a buffer using the passed bytes and length.

Sources/SwiftJavaDocumentation/Documentation.docc/SupportedFeatures.md

@@ -70,6 +70,7 @@ SwiftJava's `swift-java jextract` tool automates generating Java bindings from S
 | Existential return types `f() -> any Collection`                                     | ❌        | ❌   |
 | Foundation Data and DataProtocol: `f(x: any DataProtocol) -> Data`                   | ✅        | ❌   |
 | Foundation Date: `f(date: Date) -> Date`                                             | ❌        | ✅   |
+| Foundation UUID: `f(uuid: UUID) -> UUID`                                             | ❌        | ✅   |
 | Opaque parameters: `func take(worker: some Builder) -> some Builder`                 | ❌        | ✅   |
 | Opaque return types: `func get() -> some Builder`                                    | ❌        | ❌   |
 | Optional parameters: `func f(i: Int?, class: MyClass?)`                              | ✅        | ✅   |

Tests/JExtractSwiftTests/UUIDTests.swift

@@ -0,0 +1,115 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2025 Apple Inc. and the Swift.org project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.txt for the list of Swift.org project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+
+import JExtractSwiftLib
+import SwiftJavaConfigurationShared
+import Testing
+
+struct UUIDTests {
+  @Test(
+    "Import: accept UUID",
+    arguments: [
+      (
+        JExtractGenerationMode.jni,
+        /* expected Java chunks */
+        [
+          """
+          public static void acceptUUID(java.util.UUID uuid) {
+            SwiftModule.$acceptUUID(uuid.toString());
+          }
+          """
+        ],
+        /* expected Swift chunks */
+        [
+          """
+          @_cdecl("Java_com_example_swift_SwiftModule__00024acceptUUID__Ljava_lang_String_2")
+          public func Java_com_example_swift_SwiftModule__00024acceptUUID__Ljava_lang_String_2(environment: UnsafeMutablePointer<JNIEnv?>!, thisClass: jclass, uuid: jstring?) {
+            let uuid_string$ = String(fromJNI: uuid, in: environment)
+            guard let uuid_unwrapped$ = UUID.init(uuidString: uuid_string$) else {
+              fatalError("Invalid UUID string passed from Java: \\(uuid_string$)")
+            }
+            SwiftModule.acceptUUID(uuid: uuid_unwrapped$)
+          }
+          """
+        ],
+      )
+    ]
+  )
+  func func_accept_uuid(mode: JExtractGenerationMode, expectedJavaChunks: [String], expectedSwiftChunks: [String]) throws {
+    let text =
+      """
+      import Foundation
+
+      public func acceptUUID(uuid: UUID)
+      """
+
+    try assertOutput(
+      input: text, 
+      mode, .java,
+      detectChunkByInitialLines: 1,
+      expectedChunks: expectedJavaChunks)
+
+      try assertOutput(
+      input: text, 
+      mode, .swift,
+      detectChunkByInitialLines: 1,
+      expectedChunks: expectedSwiftChunks)
+  }  
+
+  @Test(
+    "Import: return UUID",
+    arguments: [
+      (
+        JExtractGenerationMode.jni,
+        /* expected Java chunks */
+        [
+          """
+          public static java.util.UUID returnUUID() {
+            return java.util.UUID.fromString(SwiftModule.$returnUUID());
+          }
+          """
+        ],
+        /* expected Swift chunks */
+        [
+          """
+          @_cdecl("Java_com_example_swift_SwiftModule__00024returnUUID__")
+          public func Java_com_example_swift_SwiftModule__00024returnUUID__(environment: UnsafeMutablePointer<JNIEnv?>!, thisClass: jclass) -> jstring? {
+            return SwiftModule.returnUUID().uuidString.getJNIValue(in: environment)
+          }
+          """
+        ]
+      )
+    ]
+  )
+  func func_return_UUID(mode: JExtractGenerationMode, expectedJavaChunks: [String], expectedSwiftChunks: [String]) throws {
+    let text =
+      """
+      import Foundation
+      public func returnUUID() -> UUID
+      """
+
+    try assertOutput(
+      input: text, 
+      mode, .java,
+      detectChunkByInitialLines: 1,
+      expectedChunks: expectedJavaChunks
+    )
+
+      try assertOutput(
+      input: text, 
+      mode, .swift,
+      detectChunkByInitialLines: 1,
+      expectedChunks: expectedSwiftChunks)
+  }
+}