JNI: support consumers with C++ interoperability enabled

.github/workflows/pull_request.yml

@@ -258,6 +258,13 @@ jobs:
           perl -pi -e "s#(download_and_extract_toolchain \".ANDROID_SDK_TAG\"\))#\1\n        PATH=\\\$(dirname \\\$SWIFT_EXECUTABLE_FOR_ANDROID_SDK):\\\$PATH\n        echo \"path is now \\\$PATH\"#" install-and-build-with-sdk.sh
           chmod 500 install-and-build-with-sdk.sh
           ./install-and-build-with-sdk.sh --android --build-command="swift build" --android-sdk-triple="${{ matrix.sdk_triple }}" --android-ndk-version="${{ matrix.ndk_version }}" ${{ matrix.swift_version }}
+      - name: Verify Android JNI consumer with C++ interoperability
+        if: matrix.swift_version == '6.3' && matrix.sdk_triple == 'aarch64-unknown-linux-android28' && matrix.ndk_version == 'r27d'
+        working-directory: Samples/SwiftJavaExtractJNISampleApp
+        env:
+          CXX_INTEROP: '1'
+          SWIFT_JAVA_VERBOSE: true
+        run: ./install-and-build-with-sdk.sh --android --build-command="swift build" --android-sdk-triple="${{ matrix.sdk_triple }}" --android-ndk-version="${{ matrix.ndk_version }}" ${{ matrix.swift_version }}
 
   verify-samples:
     name: Sample ${{ matrix.sample_app }} (${{ matrix.os_version }} swift:${{ matrix.swift_version }} jdk:${{matrix.jdk_vendor}})
@@ -296,6 +303,12 @@ jobs:
             ${{ runner.os }}-swift${{ matrix.swift_version }}-sample-
       - name: "Verify sample: ${{ matrix.sample_app }}"
         run: .github/scripts/validate_sample.sh Samples/${{ matrix.sample_app }}
+      - name: Verify JNI consumer with C++ interoperability
+        if: matrix.swift_version == '6.3' && (matrix.sample_app == 'JavaKitSampleApp' || matrix.sample_app == 'SwiftJavaExtractJNISampleApp')
+        env:
+          CXX_INTEROP: '1'
+          SWIFT_JAVA_VERBOSE: true
+        run: .github/scripts/validate_sample.sh Samples/${{ matrix.sample_app }}
 
 
   verify-samples-macos:
@@ -335,6 +348,12 @@ jobs:
             ${{ runner.os }}-swift${{ matrix.swift_version }}-sample-
       - name: "Verify sample ${{ matrix.sample_app }}"
         run: .github/scripts/validate_sample.sh Samples/${{ matrix.sample_app }}
+      - name: Verify JNI consumer with C++ interoperability
+        if: matrix.swift_version == '6.3' && (matrix.sample_app == 'JavaKitSampleApp' || matrix.sample_app == 'SwiftJavaExtractJNISampleApp')
+        env:
+          CXX_INTEROP: '1'
+          SWIFT_JAVA_VERBOSE: true
+        run: .github/scripts/validate_sample.sh Samples/${{ matrix.sample_app }}
 
   linkage-test:
     name: Linkage test (noble swift:6.3)

Samples/JavaKitSampleApp/Package.swift

@@ -4,6 +4,11 @@
 import CompilerPluginSupport
 import PackageDescription
 
+// Enable C++ interoperability only in the consumer targets, not their dependencies.
+let sampleSwiftSettings: [SwiftSetting] =
+  [.swiftLanguageMode(.v5)]
+  + (Context.environment["CXX_INTEROP"] == "1" ? [.interoperabilityMode(.Cxx)] : [])
+
 let package = Package(
   name: "JavaKitSampleApp",
   platforms: [
@@ -35,9 +40,7 @@ let package = Package(
         .product(name: "JavaUtilJar", package: "swift-java"),
         .product(name: "ArgumentParser", package: "swift-argument-parser"),
       ],
-      swiftSettings: [
-        .swiftLanguageMode(.v5)
-      ],
+      swiftSettings: sampleSwiftSettings,
       plugins: [
         .plugin(name: "JavaCompilerPlugin", package: "swift-java"),
         .plugin(name: "SwiftJavaPlugin", package: "swift-java"),
@@ -49,9 +52,7 @@ let package = Package(
       dependencies: [
         "JavaKitExample"
       ],
-      swiftSettings: [
-        .swiftLanguageMode(.v5)
-      ]
+      swiftSettings: sampleSwiftSettings
     ),
   ]
 )

Samples/SwiftJavaExtractJNISampleApp/Package.swift

@@ -4,6 +4,11 @@
 import CompilerPluginSupport
 import PackageDescription
 
+// Enable C++ interoperability only in the consumer targets, not their dependencies.
+let sampleSwiftSettings: [SwiftSetting] =
+  [.swiftLanguageMode(.v5)]
+  + (Context.environment["CXX_INTEROP"] == "1" ? [.interoperabilityMode(.Cxx)] : [])
+
 let package = Package(
   name: "JExtractJNISampleApp",
   platforms: [
@@ -34,9 +39,7 @@ let package = Package(
       exclude: [
         "swift-java.config"
       ],
-      swiftSettings: [
-        .swiftLanguageMode(.v5)
-      ],
+      swiftSettings: sampleSwiftSettings,
       plugins: [
         .plugin(name: "JExtractSwiftPlugin", package: "swift-java")
       ]
@@ -50,9 +53,7 @@ let package = Package(
       exclude: [
         "swift-java.config"
       ],
-      swiftSettings: [
-        .swiftLanguageMode(.v5)
-      ],
+      swiftSettings: sampleSwiftSettings,
       plugins: [
         .plugin(name: "JExtractSwiftPlugin", package: "swift-java")
       ]

Samples/SwiftJavaExtractJNISampleApp/ci-validate.sh

@@ -42,5 +42,8 @@ fi
 # FIXME: disable prebuilts until prebuilt swift-syntax isn't broken on 6.2 anymore: https://github.com/swiftlang/swift-java/issues/418
 swift build $DISABLE_EXPERIMENTAL_PREBUILTS --disable-sandbox  
 
-./gradlew run
-./gradlew test
+# A reused daemon can resolve `swift` using the PATH from an older toolchain.
+./gradlew --no-daemon run
+# Gradle does not track the Swift library as a test input. Rerun tests when
+# switching C++ interoperability so the second configuration is exercised too.
+./gradlew --no-daemon test --rerun-tasks

Sources/JExtractSwiftLib/JNI/JNISwift2JavaGenerator+NativeTranslation.swift

@@ -1515,8 +1515,8 @@ extension JNISwift2JavaGenerator {
           let typeMetadataVariableName = "\(inner)typeMetadata$"
           printer.print(
             """
-            let \(pointerVariableName) = environment.interface.CallLongMethodA(environment, \(inner), _JNIMethodIDCache.JNISwiftInstance.memoryAddress, [])
-            let \(typeMetadataVariableName) = environment.interface.CallLongMethodA(environment, \(inner), _JNIMethodIDCache.JNISwiftInstance.typeMetadataAddress, [])
+            let \(pointerVariableName) = environment.swiftInterface.CallLongMethodA(environment, \(inner), _JNIMethodIDCache.JNISwiftInstance.memoryAddress, [])
+            let \(typeMetadataVariableName) = environment.swiftInterface.CallLongMethodA(environment, \(inner), _JNIMethodIDCache.JNISwiftInstance.typeMetadataAddress, [])
             """
           )
           let existentialName = NativeSwiftConversionStep.extractSwiftProtocolValue(
@@ -1533,7 +1533,7 @@ extension JNISwift2JavaGenerator {
         // or if its a custom class implementing the interface.
         if allowsJavaImplementations {
           printer.printBraceBlock(
-            "if environment.interface.IsInstanceOf(environment, \(inner), _JNIMethodIDCache.JNISwiftInstance.class) != 0"
+            "if environment.swiftInterface.IsInstanceOf(environment, \(inner), _JNIMethodIDCache.JNISwiftInstance.class) != 0"
           ) { printer in
             printStandardJExtractBlock(&printer)
           }
@@ -1702,15 +1702,15 @@ extension JNISwift2JavaGenerator {
 
         printer.print(
           """
-          let class$ = environment.interface.GetObjectClass(environment, \(placeholder))
-          let methodID$ = environment.interface.GetMethodID(environment, class$, "\(methodName)", "\(methodSignature.mangledName)")!
-          environment.interface.DeleteLocalRef(environment, class$)
-          let arguments$: [jvalue] = [\(arguments.joined(separator: .comma))]
+          let class$ = environment.swiftInterface.GetObjectClass(environment, \(placeholder))
+          let methodID$ = environment.swiftInterface.GetMethodID(environment, class$, "\(methodName)", "\(methodSignature.mangledName)")!
+          environment.swiftInterface.DeleteLocalRef(environment, class$)
+          let arguments$: [JNITypes.jvalue] = [\(arguments.joined(separator: .comma))]
           """
         )
 
         let upcall =
-          "environment.interface.\(nativeResult.javaType.jniCallMethodAName)(environment, \(placeholder), methodID$, arguments$)"
+          "environment.swiftInterface.\(nativeResult.javaType.jniCallMethodAName)(environment, \(placeholder), methodID$, arguments$)"
         let result = nativeResult.conversion.render(&printer, upcall)
 
         if nativeResult.javaType.isVoid {
@@ -1818,7 +1818,7 @@ extension JNISwift2JavaGenerator {
         let discriminatorParameterName
       ):
         if !returnType.isVoid {
-          printer.print("let \(resultName): \(returnType.jniTypeName)")
+          printer.print("let \(resultName): \(returnType.swiftJNITypeName)")
         }
         printer.printIfBlock("let innerResult$ = \(placeholder)") { printer in
           let inner = inner.render(&printer, "innerResult$")
@@ -1828,7 +1828,7 @@ extension JNISwift2JavaGenerator {
           printer.print(
             """
             var flag$ = Int8(1)
-            environment.interface.SetByteArrayRegion(environment, \(discriminatorParameterName), 0, 1, &flag$)
+            environment.swiftInterface.SetByteArrayRegion(environment, \(discriminatorParameterName), 0, 1, &flag$)
             """
           )
         }
@@ -1839,7 +1839,7 @@ extension JNISwift2JavaGenerator {
           printer.print(
             """
             var flag$ = Int8(0)
-            environment.interface.SetByteArrayRegion(environment, \(discriminatorParameterName), 0, 1, &flag$)
+            environment.swiftInterface.SetByteArrayRegion(environment, \(discriminatorParameterName), 0, 1, &flag$)
             """
           )
         }
@@ -1854,10 +1854,10 @@ extension JNISwift2JavaGenerator {
         printer.printBraceBlock("do") { printer in
           printer.print(
             """
-            environment.interface.SetLongField(environment, \(outArgumentName), _JNIMethodIDCache._OutSwiftGenericInstance.selfPointer, \(inner))
+            environment.swiftInterface.SetLongField(environment, \(outArgumentName), _JNIMethodIDCache._OutSwiftGenericInstance.selfPointer, \(inner))
             let metadataPointer = unsafeBitCast(\(swiftFunctionResultType).self, to: UnsafeRawPointer.self)
             let metadataPointerBits$ = Int64(Int(bitPattern: metadataPointer))
-            environment.interface.SetLongField(environment, \(outArgumentName), _JNIMethodIDCache._OutSwiftGenericInstance.selfTypePointer, metadataPointerBits$.getJNIValue(in: environment))
+            environment.swiftInterface.SetLongField(environment, \(outArgumentName), _JNIMethodIDCache._OutSwiftGenericInstance.selfTypePointer, metadataPointerBits$.getJNIValue(in: environment))
             """
           )
         }
@@ -1869,8 +1869,8 @@ extension JNISwift2JavaGenerator {
           printer.print(
             """
             let (selfPointerBits$, selfTypePointerBits$) = \(boxed)
-            environment.interface.SetLongField(environment, \(outArgumentName), _JNIMethodIDCache._OutSwiftGenericInstance.selfPointer, selfPointerBits$.getJNIValue(in: environment))
-            environment.interface.SetLongField(environment, \(outArgumentName), _JNIMethodIDCache._OutSwiftGenericInstance.selfTypePointer, selfTypePointerBits$.getJNIValue(in: environment))
+            environment.swiftInterface.SetLongField(environment, \(outArgumentName), _JNIMethodIDCache._OutSwiftGenericInstance.selfPointer, selfPointerBits$.getJNIValue(in: environment))
+            environment.swiftInterface.SetLongField(environment, \(outArgumentName), _JNIMethodIDCache._OutSwiftGenericInstance.selfTypePointer, selfTypePointerBits$.getJNIValue(in: environment))
             """
           )
         }
@@ -1941,20 +1941,20 @@ extension JNISwift2JavaGenerator {
         // Global ref all indirect returns
         for outParameter in nativeFunctionSignature.result.outParameters {
           printer.print(
-            "nonisolated(unsafe) let \(outParameter.name) = environment.interface.NewGlobalRef(environment, \(outParameter.name))"
+            "nonisolated(unsafe) let \(outParameter.name) = environment.swiftInterface.NewGlobalRef(environment, \(outParameter.name))"
           )
           globalRefs.append(outParameter.name)
         }
 
         // We also need to global ref any objects passed in
         for parameter in nativeFunctionSignature.parameters.flatMap(\.parameters) where !parameter.type.isPrimitive {
-          printer.print("nonisolated(unsafe) let \(parameter.name) = environment.interface.NewGlobalRef(environment, \(parameter.name))")
+          printer.print("nonisolated(unsafe) let \(parameter.name) = environment.swiftInterface.NewGlobalRef(environment, \(parameter.name))")
           globalRefs.append(parameter.name)
         }
 
         printer.print(
           """
-          nonisolated(unsafe) let globalFuture = environment.interface.NewGlobalRef(environment, result_future)
+          nonisolated(unsafe) let globalFuture = environment.swiftInterface.NewGlobalRef(environment, result_future)
           """
         )
 
@@ -1993,7 +1993,7 @@ extension JNISwift2JavaGenerator {
             printer.print("\(tryAwaitString) \(placeholderWithoutTry)")
             printer.print("environment = try! JavaVirtualMachine.shared().environment()")
             printer.print(
-              "_ = environment.interface.CallBooleanMethodA(environment, globalFuture, \(completeMethodID), [jvalue(l: nil)])"
+              "_ = environment.swiftInterface.CallBooleanMethodA(environment, globalFuture, \(completeMethodID), [JNITypes.objectValue(nil)])"
             )
           } else {
             printer.print("let swiftResult$ = \(tryAwaitString) \(placeholderWithoutTry)")
@@ -2013,7 +2013,7 @@ extension JNISwift2JavaGenerator {
             }
 
             printer.print(
-              "_ = environment.interface.CallBooleanMethodA(environment, globalFuture, \(completeMethodID), [jvalue(l: \(result))])"
+              "_ = environment.swiftInterface.CallBooleanMethodA(environment, globalFuture, \(completeMethodID), [JNITypes.objectValue(\(result))])"
             )
           }
         }
@@ -2026,7 +2026,7 @@ extension JNISwift2JavaGenerator {
             // Defer might on any thread, so we need to attach environment.
             printer.print("let deferEnvironment = try! JavaVirtualMachine.shared().environment()")
             for globalRef in globalRefs {
-              printer.print("deferEnvironment.interface.DeleteGlobalRef(deferEnvironment, \(globalRef))")
+              printer.print("deferEnvironment.swiftInterface.DeleteGlobalRef(deferEnvironment, \(globalRef))")
             }
           }
           if isThrowing {
@@ -2039,7 +2039,7 @@ extension JNISwift2JavaGenerator {
                 """
                 let catchEnvironment = try! JavaVirtualMachine.shared().environment()
                 let exception = catchEnvironment.makeJavaThrowable(for: error)
-                _ = catchEnvironment.interface.CallBooleanMethodA(catchEnvironment, globalFuture, \(completeExceptionallyMethodID), [jvalue(l: exception)])
+                _ = catchEnvironment.swiftInterface.CallBooleanMethodA(catchEnvironment, globalFuture, \(completeExceptionallyMethodID), [JNITypes.objectValue(exception)])
                 """
               )
             }
@@ -2107,9 +2107,9 @@ extension JNISwift2JavaGenerator {
         let releaseMode = mutable ? "0" : "jint(JNI_ABORT)"
         printer.print(
           """
-          let \(countVar) = Int(environment.interface.GetArrayLength(environment, \(inner)))
-          let \(ptrVar) = environment.interface.GetByteArrayElements(environment, \(inner), nil)!
-          defer { environment.interface.ReleaseByteArrayElements(environment, \(inner), \(ptrVar), \(releaseMode)) }
+          let \(countVar) = Int(environment.swiftInterface.GetArrayLength(environment, \(inner)))
+          let \(ptrVar) = environment.swiftInterface.GetByteArrayElements(environment, \(inner), nil)!
+          defer { environment.swiftInterface.ReleaseByteArrayElements(environment, \(inner), \(ptrVar), \(releaseMode)) }
           let \(rbpVar) = \(bufferPointerType)(start: \(ptrVar), count: \(countVar))
           """
         )
@@ -2138,12 +2138,12 @@ extension JNISwift2JavaGenerator {
             let setMethodName = element.javaType.jniSetArrayRegionMethodName
             printer.print("var element_\(element.index)_jni$ = \(converted)")
             printer.print(
-              "environment.interface.\(setMethodName)(environment, \(element.outParamName), 0, 1, &element_\(element.index)_jni$)"
+              "environment.swiftInterface.\(setMethodName)(environment, \(element.outParamName), 0, 1, &element_\(element.index)_jni$)"
             )
           case .class, .array:
             printer.print("let element_\(element.index)_jni$ = \(converted)")
             printer.print(
-              "environment.interface.SetObjectArrayElement(environment, \(element.outParamName), 0, element_\(element.index)_jni$)"
+              "environment.swiftInterface.SetObjectArrayElement(environment, \(element.outParamName), 0, element_\(element.index)_jni$)"
             )
           }
         }

Sources/JExtractSwiftLib/JNI/JNISwift2JavaGenerator+SwiftThunkPrinting.swift

@@ -892,15 +892,17 @@ extension JNISwift2JavaGenerator {
     self.generatedCDeclSymbolNames.append(cName)
 
     let translatedParameters = parameters.map {
-      "\($0.name): \($0.type.jniTypeName)"
+      "\($0.name): \($0.type.swiftJNITypeName)"
     }
 
+    // Use the Swift alias defined in the runtime's C import context. Importing
+    // Android's JNIEnv directly in a C++-enabled client makes it a C++ struct.
     let thunkParameters =
       [
-        "environment: UnsafeMutablePointer<JNIEnv?>!",
-        "thisClass: jclass",
+        "environment: JNIEnvironment!",
+        "thisClass: JNITypes.jclass",
       ] + translatedParameters
-    let thunkReturnType = resultType != .void ? " -> \(resultType.jniTypeName)" : ""
+    let thunkReturnType = resultType != .void ? " -> \(resultType.swiftJNITypeName)" : ""
 
     // TODO: Think about function overloads
     printer.printBraceBlock(
@@ -944,7 +946,7 @@ extension JNISwift2JavaGenerator {
           methods: [wrapMemoryAddressUnsafeMethod]
         )
 
-        static var javaClass: jclass {
+        static var javaClass: JNITypes.jclass {
           cache.javaClass
         }
 
@@ -960,7 +962,7 @@ extension JNISwift2JavaGenerator {
   private func printThrowableErrorConformance(_ printer: inout SwiftPrinter, _ type: ExtractedNominalType) {
     let bridgeName = JNICaching.bridgeName(for: type)
     printer.printBraceBlock("extension \(type.effectiveSwiftTypeName): _JNIThrowableError") { printer in
-      printer.printBraceBlock("public func _makeJavaThrowable(in environment: JNIEnvironment) -> jthrowable?") { printer in
+      printer.printBraceBlock("public func _makeJavaThrowable(in environment: JNIEnvironment) -> JNITypes.jthrowable?") { printer in
         printer.print("\(bridgeName).toJavaObject(self, in: environment)")
       }
     }
@@ -995,7 +997,7 @@ extension JNISwift2JavaGenerator {
     printer.printBraceBlock(bridgeDeclaration) { printer in
       printer.print("typealias SwiftType = \(bridgedSwiftType)")
       printer.println()
-      printer.printBraceBlock("static var javaClass: jclass") { printer in
+      printer.printBraceBlock("static var javaClass: JNITypes.jclass") { printer in
         printer.print("\(cacheName).javaClass")
       }
       printer.println()
@@ -1167,15 +1169,15 @@ extension JNISwift2JavaGenerator {
       let resultType = nativeSignature.result.javaType
 
       let translatedParameters = parameters.map {
-        "\($0.name): \($0.type.jniTypeName)"
+        "\($0.name): \($0.type.swiftJNITypeName)"
       }
 
       let thunkParameters =
         [
-          "environment: UnsafeMutablePointer<JNIEnv?>!",
-          "thisClass: jclass",
+          "environment: JNIEnvironment!",
+          "thisClass: JNITypes.jclass",
         ] + translatedParameters
-      let thunkReturnType = resultType != .void ? " -> \(resultType.jniTypeName)" : ""
+      let thunkReturnType = resultType != .void ? " -> \(resultType.swiftJNITypeName)" : ""
 
       let signature = #"static func \#(decl.openerMethodName)(\#(thunkParameters.joined(separator: .comma)))\#(thunkReturnType)"#
       if !skipMethodBody {