[JExtract/JNI] Add support for classes/structs as parameters and return values

Sources/JExtractSwiftLib/JNI/JNISwift2JavaGenerator+JavaBindingsPrinting.swift

@@ -181,9 +181,9 @@ extension JNISwift2JavaGenerator {
       return
     }
 
-    var modifiers = "public"
+    var modifiers = ["public"]
     if decl.isStatic || decl.isInitializer || !decl.hasParent {
-      modifiers.append(" static")
+      modifiers.append("static")
     }
 
     let translatedSignature = translatedDecl.translatedFunctionSignature
@@ -194,9 +194,12 @@ extension JNISwift2JavaGenerator {
     }
     let throwsClause = decl.isThrowing ? " throws Exception" : ""
 
+    let modifiersStr = modifiers.joined(separator: " ")
+    let parametersStr = parameters.joined(separator: ", ")
+
     printDeclDocumentation(&printer, decl)
     printer.printBraceBlock(
-      "\(modifiers) \(resultType) \(translatedDecl.name)(\(parameters.joined(separator: ", ")))\(throwsClause)"
+      "\(modifiersStr) \(resultType) \(translatedDecl.name)(\(parametersStr))\(throwsClause)"
     ) { printer in
       printDowncall(&printer, decl)
     }
@@ -208,14 +211,13 @@ extension JNISwift2JavaGenerator {
     let translatedDecl = translatedDecl(for: decl)! // Will always call with valid decl
     let nativeSignature = translatedDecl.nativeFunctionSignature
     let resultType = nativeSignature.result.javaType
-    let nativeName = "$\(translatedDecl.name)"
     var parameters = nativeSignature.parameters
     if let selfParameter = nativeSignature.selfParameter {
       parameters.append(selfParameter)
     }
     let renderedParameters = parameters.map { "\($0.javaParameter.type) \($0.javaParameter.name)"}.joined(separator: ", ")
 
-    printer.print("private static native \(resultType) \(nativeName)(\(renderedParameters));")
+    printer.print("private static native \(resultType) \(translatedDecl.nativeFunctionName)(\(renderedParameters));")
   }
 
   private func printDowncall(
@@ -241,7 +243,7 @@ extension JNISwift2JavaGenerator {
     //=== Part 3: Downcall.
     // TODO: If we always generate a native method and a "public" method, we can actually choose our own thunk names
     // using the registry?
-    let downcall = "\(translatedDecl.parentName).$\(translatedDecl.name)(\(arguments.joined(separator: ", ")))"
+    let downcall = "\(translatedDecl.parentName).\(translatedDecl.nativeFunctionName)(\(arguments.joined(separator: ", ")))"
 
     //=== Part 4: Convert the return value.
     if translatedFunctionSignature.resultType.javaType.isVoid {

Sources/JExtractSwiftLib/JNI/JNISwift2JavaGenerator+JavaTranslation.swift

@@ -61,6 +61,7 @@ extension JNISwift2JavaGenerator {
 
       return TranslatedFunctionDecl(
         name: javaName,
+        nativeFunctionName: "$\(javaName)",
         parentName: parentName,
         translatedFunctionSignature: translatedFunctionSignature,
         nativeFunctionSignature: nativeFunctionSignature
@@ -161,6 +162,9 @@ extension JNISwift2JavaGenerator {
     /// Java function name
     let name: String
 
+    /// The name of the native function
+    let nativeFunctionName: String
+
     /// The name of the Java parent scope this function is declared in
     let parentName: String
 

Sources/JExtractSwiftLib/JNI/JNISwift2JavaGenerator+NativeTranslation.swift

@@ -110,7 +110,7 @@ extension JNISwift2JavaGenerator {
       // so we pass the pointer.
       return NativeResult(
         javaType: .long,
-        conversion: .getJNIValue(.allocateSwiftValue(name: "_result", swiftType: swiftResult.type))
+        conversion: .getJNIValue(.allocateSwiftValue(name: "result", swiftType: swiftResult.type))
       )
     }
   }
@@ -189,14 +189,16 @@ extension JNISwift2JavaGenerator {
         return "\(inner)$"
 
       case .allocateSwiftValue(let name, let swiftType):
+        let pointerName = "\(name)$"
+        let bitsName = "\(name)Bits$"
         printer.print(
           """
-          let \(name)$ = UnsafeMutablePointer<\(swiftType)>.allocate(capacity: 1)
-          \(name)$.initialize(to: \(placeholder))
-          let \(name)Bits$ = Int64(Int(bitPattern: \(name)$))
+          let \(pointerName) = UnsafeMutablePointer<\(swiftType)>.allocate(capacity: 1)
+          \(pointerName).initialize(to: \(placeholder))
+          let \(bitsName) = Int64(Int(bitPattern: \(pointerName)))
           """
         )
-        return "\(name)Bits$"
+        return bitsName
 
       case .pointee(let inner):
         let inner = inner.render(&printer, placeholder)

Sources/JExtractSwiftLib/JNI/JNISwift2JavaGenerator+SwiftThunkPrinting.swift

@@ -133,7 +133,7 @@ extension JNISwift2JavaGenerator {
 
     printCDecl(
       &printer,
-      javaMethodName: "$\(translatedDecl.name)",
+      javaMethodName: translatedDecl.nativeFunctionName,
       parentName: translatedDecl.parentName,
       parameters: parameters.map(\.javaParameter),
       resultType: nativeSignature.result.javaType.jniType

Sources/JExtractSwiftLib/JNI/JNIType.swift

@@ -14,6 +14,9 @@
 
 import JavaTypes
 
+/// Represents types that are able to be passed over a JNI boundary.
+///
+/// - SeeAlso: https://docs.oracle.com/javase/8/docs/technotes/guides/jni/spec/types.html
 enum JNIType {
   case jboolean
   case jfloat

Tests/JExtractSwiftTests/Asserts/TextAssertions.swift

@@ -115,7 +115,6 @@ func assertOutput(
       print("==== ---------------------------------------------------------------")
 
       #expect(output.contains(expectedChunk), sourceLocation: sourceLocation)
-//      fatalError("Failed: \(filePath):\(line)")
       continue
     }
 

Tests/JExtractSwiftTests/JNI/JNIClassTests.swift

@@ -185,19 +185,19 @@ struct JNIClassTests {
         """
         @_cdecl("Java_com_example_swift_MyClass__00024init__JJ")
         func Java_com_example_swift_MyClass__00024init__JJ(environment: UnsafeMutablePointer<JNIEnv?>!, thisClass: jclass, x: jlong, y: jlong) -> jlong {
-          let _result$ = UnsafeMutablePointer<MyClass>.allocate(capacity: 1)
-          _result$.initialize(to: MyClass.init(x: Int64(fromJNI: x, in: environment!), y: Int64(fromJNI: y, in: environment!)))
-          let _resultBits$ = Int64(Int(bitPattern: _result$))
-          return _resultBits$.getJNIValue(in: environment!)
+          let result$ = UnsafeMutablePointer<MyClass>.allocate(capacity: 1)
+          result$.initialize(to: MyClass.init(x: Int64(fromJNI: x, in: environment!), y: Int64(fromJNI: y, in: environment!)))
+          let resultBits$ = Int64(Int(bitPattern: result$))
+          return resultBits$.getJNIValue(in: environment!)
         }
         """,
         """
         @_cdecl("Java_com_example_swift_MyClass__00024init__")
         func Java_com_example_swift_MyClass__00024init__(environment: UnsafeMutablePointer<JNIEnv?>!, thisClass: jclass) -> jlong {
-          let _result$ = UnsafeMutablePointer<MyClass>.allocate(capacity: 1)
-          _result$.initialize(to: MyClass.init())
-          let _resultBits$ = Int64(Int(bitPattern: _result$))
-          return _resultBits$.getJNIValue(in: environment!)
+          let result$ = UnsafeMutablePointer<MyClass>.allocate(capacity: 1)
+          result$.initialize(to: MyClass.init())
+          let resultBits$ = Int64(Int(bitPattern: result$))
+          return resultBits$.getJNIValue(in: environment!)
         }
         """
       ]
@@ -320,10 +320,10 @@ struct JNIClassTests {
           guard let self$ = UnsafeMutablePointer<MyClass>(bitPattern: selfBits$) else {
             fatalError("self memory address was null in call to \\(#function)!")
           }
-          let _result$ = UnsafeMutablePointer<MyClass>.allocate(capacity: 1)
-          _result$.initialize(to: self$.pointee.copy())
-          let _resultBits$ = Int64(Int(bitPattern: _result$))
-          return _resultBits$.getJNIValue(in: environment!)
+          let result$ = UnsafeMutablePointer<MyClass>.allocate(capacity: 1)
+          result$.initialize(to: self$.pointee.copy())
+          let resultBits$ = Int64(Int(bitPattern: result$))
+          return resultBits$.getJNIValue(in: environment!)
         }
         """,
       ]

Tests/JExtractSwiftTests/JNI/JNIStructTests.swift

@@ -119,10 +119,10 @@ struct JNIStructTests {
         """
         @_cdecl("Java_com_example_swift_MyStruct__00024init__JJ")
         func Java_com_example_swift_MyStruct__00024init__JJ(environment: UnsafeMutablePointer<JNIEnv?>!, thisClass: jclass, x: jlong, y: jlong) -> jlong {
-          let _result$ = UnsafeMutablePointer<MyStruct>.allocate(capacity: 1)
-          _result$.initialize(to: MyStruct.init(x: Int64(fromJNI: x, in: environment!), y: Int64(fromJNI: y, in: environment!)))
-          let _resultBits$ = Int64(Int(bitPattern: _result$))
-          return _resultBits$.getJNIValue(in: environment!)
+          let result$ = UnsafeMutablePointer<MyStruct>.allocate(capacity: 1)
+          result$.initialize(to: MyStruct.init(x: Int64(fromJNI: x, in: environment!), y: Int64(fromJNI: y, in: environment!)))
+          let resultBits$ = Int64(Int(bitPattern: result$))
+          return resultBits$.getJNIValue(in: environment!)
         }
         """
       ]