jextract: Support Java LongSupplier func interface

Samples/SwiftAndJavaJarFFMSampleLib/Sources/MySwiftLibrary/MySwiftLibrary.swift

@@ -44,6 +44,10 @@ public func globalCallMeIntSupplier(run: () -> Int32) -> Int32 {
   run()
 }
 
+public func globalCallMeLongSupplier(run: () -> Int64) -> Int64 {
+  run()
+}
+
 public func globalCallMeDoubleSupplier(run: () -> Double) -> Double {
   run()
 }

Samples/SwiftAndJavaJarFFMSampleLib/src/test/java/com/example/swift/MySwiftLibraryTest.java

@@ -66,6 +66,12 @@ void call_globalCallMeIntSupplier_noThrow() {
         assertEquals(1, result);
     }
 
+    @Test
+    void call_globalCallMeLongSupplier_noThrow() {
+        long result = MySwiftLibrary.globalCallMeLongSupplier(() -> { return 1L; });
+        assertEquals(1L, result);
+    }
+
     @Test
     void call_globalCallMeDoubleSupplier_noThrow() {
         double result = MySwiftLibrary.globalCallMeBooleanSupplier(() -> { return 2.0; });

Samples/SwiftJavaExtractFFMSampleApp/Sources/MySwiftLibrary/MySwiftLibrary.swift

@@ -56,6 +56,10 @@ public func globalCallMeIntSupplier(run: () -> Int32) -> Int32 {
   run()
 }
 
+public func globalCallMeLongSupplier(run: () -> Int64) -> Int64 {
+  run()
+}
+
 public func globalCallMeDoubleSupplier(run: () -> Double) -> Double {
   run()
 }

Samples/SwiftJavaExtractFFMSampleApp/src/test/java/com/example/swift/MySwiftLibraryTest.java

@@ -178,6 +178,12 @@ void call_globalCallMeIntSupplier_noThrow() {
         assertEquals(2, result);
     }
 
+    @Test
+    void call_globalCallMeLongSupplier_noThrow() {
+        long result = MySwiftLibrary.globalCallMeLongSupplier(() -> { return 2L; });
+        assertEquals(2L, result);
+    }
+
     @Test
     void call_globalCallMeDoubleSupplier_noThrow() {
         double result = MySwiftLibrary.globalCallMeDoubleSupplier(() -> { return 2.0; });

Samples/SwiftJavaExtractJNISampleApp/Sources/MySwiftLibrary/Closures.swift

@@ -29,6 +29,10 @@ public func globalCallMeIntSupplier(run: () -> Int32) -> Int32 {
   run()
 }
 
+public func globalCallMeLongSupplier(run: () -> Int64) -> Int64 {
+  run()
+}
+
 public func globalCallMeDoubleSupplier(run: () -> Double) -> Double {
   run()
 }

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

@@ -60,6 +60,12 @@ void globalCallMeIntSupplier() {
         assertEquals(2, result);
     }
 
+    @Test
+    void globalCallMeLongSupplier() {
+        long result = MySwiftLibrary.globalCallMeLongSupplier(() -> 2L);
+        assertEquals(2L, result);
+    }
+
     @Test
     void globalCallMeDoubleSupplier() {
         double result = MySwiftLibrary.globalCallMeDoubleSupplier(() -> 2.0);

Sources/ExampleSwiftLibrary/MySwiftLibrary.swift

@@ -51,6 +51,10 @@ public func globalCallMeIntSupplier(run: () -> Int32) -> Int32 {
   run()
 }
 
+public func globalCallMeLongSupplier(run: () -> Int64) -> Int64 {
+  run()
+}
+
 public func globalCallMeDoubleSupplier(run: () -> Double) -> Double {
   run()
 }

Sources/JExtractSwiftLib/JavaTypes/JavaType+JDK.swift

@@ -40,6 +40,11 @@ extension JavaType {
     .class(package: "java.util.function", name: "IntSupplier")
   }
 
+  /// The description of the type java.util.function.LongSupplier.
+  static var javaUtilFunctionLongSupplier: JavaType {
+    .class(package: "java.util.function", name: "LongSupplier")
+  }
+
   /// The description of the type java.util.function.DoubleSupplier.
   static var javaUtilFunctionDoubleSupplier: JavaType {
     .class(package: "java.util.function", name: "DoubleSupplier")

Sources/JExtractSwiftLib/KnownFunctionalInterfaces.swift

@@ -43,6 +43,13 @@ struct KnownJavaFunctionalInterface: Sendable {
     result: .int
   )
 
+  static let longSupplier = KnownJavaFunctionalInterface(
+    JavaType.javaUtilFunctionLongSupplier,
+    method: "getAsLong",
+    parameters: [],
+    result: .long
+  )
+
   static let doubleSupplier = KnownJavaFunctionalInterface(
     JavaType.javaUtilFunctionDoubleSupplier,
     method: "getAsDouble",
@@ -54,6 +61,7 @@ struct KnownJavaFunctionalInterface: Sendable {
     .runnable,
     .booleanSupplier,
     .intSupplier,
+    .longSupplier,
     .doubleSupplier,
   ]
 
@@ -87,6 +95,8 @@ struct KnownJavaFunctionalInterface: Sendable {
       booleanSupplier
     case ([], _) where result.isInt32:
       intSupplier
+    case ([], _) where result.isInt64:
+      longSupplier
     case ([], _) where result.isDouble:
       doubleSupplier
     default:

Sources/SwiftExtract/SwiftTypes/SwiftType.swift

@@ -151,6 +151,17 @@ public enum SwiftType: Equatable {
     }
   }
 
+  public var isInt64: Bool {
+    switch self {
+    case .nominal(let nominal):
+      switch nominal.nominalTypeDecl.knownTypeKind {
+      case .int64, .uint64: true
+      default: false
+      }
+    default: false
+    }
+  }
+
   public var isUnsignedInteger: Bool {
     switch self {
     case .nominal(let nominal):

Tests/JExtractSwiftTests/FuncCallbackImportTests.swift

@@ -36,6 +36,7 @@ final class FuncCallbackImportTests {
     public func callMe(callback: () -> Void)
     public func callMeBoolSupplier(callback: () -> Bool)
     public func callMeIntSupplier(callback: () -> Int32)
+    public func callMeLongSupplier(callback: () -> Int64)
     public func callMeDoubleSupplier(callback: () -> Double)
     public func callMeMore(callback: (UnsafeRawPointer, Float) -> Int, fn: () -> ())
     public func withBuffer(body: (UnsafeRawBufferPointer) -> Int)
@@ -254,6 +255,49 @@ final class FuncCallbackImportTests {
     )
   }
 
+  @Test("Import: public func callMeLongSupplier(callback: () -> Int64)")
+  func func_callMeLongSupplierFunc_callback() throws {
+    var config = Configuration()
+    config.swiftModule = "__FakeModule"
+    let st = makeSwiftJavaAnalyzer(config: config)
+    st.log.logLevel = .error
+
+    try st.analyze(path: "Fake.swift", text: Self.class_interfaceFile)
+
+    let funcDecl = st.extractedGlobalFuncs.first { $0.name == "callMeLongSupplier" }!
+
+    let generator = FFMSwift2JavaGenerator(
+      config: config,
+      translator: st,
+      javaPackage: "com.example.swift",
+      swiftOutputDirectory: "/fake",
+      javaOutputDirectory: "/fake"
+    )
+
+    let output = JavaPrinter.toString { printer in
+      generator.printFunctionDowncallMethods(&printer, funcDecl)
+    }
+
+    assertOutput(
+      output,
+      expectedChunks: [
+        """
+        /**
+         * Downcall to Swift:
+         * {@snippet lang=swift :
+         * public func callMeLongSupplier(callback: () -> Int64)
+         * }
+         */
+        public static void callMeLongSupplier(java.util.function.LongSupplier callback) {
+          try(var arena$ = Arena.ofConfined()) {
+            swiftjava___FakeModule_callMeLongSupplier_callback.call(callMeLongSupplier.$toUpcallStub(callback, arena$));
+          }
+        }
+        """
+      ]
+    )
+  }
+
   @Test("Import: public func callMeDoubleSupplier(callback: () -> Double)")
   func func_callMeDoubleSupplierFunc_callback() throws {
     var config = Configuration()

Tests/JExtractSwiftTests/JNI/JNIClosureTests.swift

@@ -22,6 +22,7 @@ struct JNIClosureTests {
     public func emptyClosure(closure: () -> ()) {}
     public func closureBoolSupplier(closure: () -> Bool) {}
     public func closureIntSupplier(closure: () -> Int32) {}
+    public func closureLongSupplier(closure: () -> Int64) {}
     public func closureDoubleSupplier(closure: () -> Double) {}
     public func closureWithArgumentsAndReturn(closure: (Int64, Bool) -> Int64) {}
     """
@@ -101,6 +102,31 @@ struct JNIClosureTests {
     )
   }
 
+  @Test
+  func closureLongSupplier_javaBindings() throws {
+    try assertOutput(
+      input: source,
+      .jni,
+      .java,
+      expectedChunks: [
+        """
+        /**
+         * Downcall to Swift:
+         * {@snippet lang=swift :
+         * public func closureLongSupplier(closure: () -> Int64)
+         * }
+         */
+        public static void closureLongSupplier(java.util.function.LongSupplier closure) {
+          SwiftModule.$closureLongSupplier(closure);
+        }
+        """,
+        """
+        private static native void $closureLongSupplier(java.util.function.LongSupplier closure);
+        """,
+      ]
+    )
+  }
+
   @Test
   func closureDoubleSupplier_javaBindings() throws {
     try assertOutput(
@@ -201,6 +227,31 @@ struct JNIClosureTests {
     )
   }
 
+  @Test
+  func closureLongSupplier_swiftThunks() throws {
+    try assertOutput(
+      input: source,
+      .jni,
+      .swift,
+      detectChunkByInitialLines: 1,
+      expectedChunks: [
+        """
+        @_cdecl("Java_com_example_swift_SwiftModule__00024closureLongSupplier__Ljava_util_function_LongSupplier_2")
+        public func Java_com_example_swift_SwiftModule__00024closureLongSupplier__Ljava_util_function_LongSupplier_2(environment: UnsafeMutablePointer<JNIEnv?>!, thisClass: jclass, closure: jobject?) {
+          SwiftModule.closureLongSupplier(closure: {
+            let class$ = environment.interface.GetObjectClass(environment, closure)
+            let methodID$ = environment.interface.GetMethodID(environment, class$, "getAsLong", "()J")!
+            environment.interface.DeleteLocalRef(environment, class$)
+            let arguments$: [jvalue] = []
+            return Int64(fromJNI: environment.interface.CallLongMethodA(environment, closure, methodID$, arguments$), in: environment)
+          }
+          )
+        }
+        """
+      ]
+    )
+  }
+
   @Test
   func closureDoubleSupplier_swiftThunks() throws {
     try assertOutput(