[JExtract/JNI] Support JavaKit wrapped types as function parameters. (#330)

Author: madsodgaard

Plugins/JExtractSwiftPlugin/JExtractSwiftPlugin.swift

@@ -15,6 +15,8 @@
 import Foundation
 import PackagePlugin
 
+fileprivate let SwiftJavaConfigFileName = "swift-java.config"
+
 @main
 struct JExtractSwiftBuildToolPlugin: SwiftJavaPluginProtocol, BuildToolPlugin {
 
@@ -51,12 +53,14 @@ struct JExtractSwiftBuildToolPlugin: SwiftJavaPluginProtocol, BuildToolPlugin {
       log("Skipping jextract step, no 'javaPackage' configuration in \(getSwiftJavaConfigPath(target: target) ?? "")")
       return []
     }
-    
+
     // We use the the usual maven-style structure of "src/[generated|main|test]/java/..."
     // that is common in JVM ecosystem
     let outputJavaDirectory = context.outputJavaDirectory
     let outputSwiftDirectory = context.outputSwiftDirectory
 
+    let dependentConfigFiles = searchForDependentConfigFiles(in: target)
+
     var arguments: [String] = [
       /*subcommand=*/"jextract",
       "--swift-module", sourceModule.name,
@@ -71,6 +75,16 @@ struct JExtractSwiftBuildToolPlugin: SwiftJavaPluginProtocol, BuildToolPlugin {
       //       as it depends on the contents of the input files. Therefore we have to implement this as a prebuild plugin.
       //       We'll have to make up some caching inside the tool so we don't re-parse files which have not changed etc.
     ]
+
+    let dependentConfigFilesArguments = dependentConfigFiles.flatMap { moduleAndConfigFile in
+      let (moduleName, configFile) = moduleAndConfigFile
+      return [
+        "--depends-on",
+        "\(configFile.path(percentEncoded: false))"
+      ]
+    }
+    arguments += dependentConfigFilesArguments
+
     if !javaPackage.isEmpty {
       arguments += ["--java-package", javaPackage]
     }
@@ -117,5 +131,53 @@ struct JExtractSwiftBuildToolPlugin: SwiftJavaPluginProtocol, BuildToolPlugin {
       )
     ]
   }
+
+  /// Find the manifest files from other swift-java executions in any targets
+  /// this target depends on.
+  func searchForDependentConfigFiles(in target: any Target) -> [(String, URL)] {
+    var dependentConfigFiles = [(String, URL)]()
+
+    func _searchForConfigFiles(in target: any Target) {
+      // log("Search for config files in target: \(target.name)")
+      let dependencyURL = URL(filePath: target.directory.string)
+
+      // Look for a config file within this target.
+      let dependencyConfigURL = dependencyURL
+        .appending(path: SwiftJavaConfigFileName)
+      let dependencyConfigString = dependencyConfigURL
+        .path(percentEncoded: false)
+
+      if FileManager.default.fileExists(atPath: dependencyConfigString) {
+        dependentConfigFiles.append((target.name, dependencyConfigURL))
+      }
+    }
+
+    // Process direct dependencies of this target.
+    for dependency in target.dependencies {
+      switch dependency {
+      case .target(let target):
+        // log("Dependency target: \(target.name)")
+        _searchForConfigFiles(in: target)
+
+      case .product(let product):
+        // log("Dependency product: \(product.name)")
+        for target in product.targets {
+          // log("Dependency product: \(product.name), target: \(target.name)")
+          _searchForConfigFiles(in: target)
+        }
+
+      @unknown default:
+        break
+      }
+    }
+
+    // Process indirect target dependencies.
+    for dependency in target.recursiveTargetDependencies {
+      // log("Recursive dependency target: \(dependency.name)")
+      _searchForConfigFiles(in: dependency)
+    }
+
+    return dependentConfigFiles
+  }
 }
 

Samples/JExtractJNISampleApp/Sources/MySwiftLibrary/MySwiftClass.swift

@@ -12,6 +12,8 @@
 //
 //===----------------------------------------------------------------------===//
 
+import JavaKit
+
 public class MySwiftClass {
   public let x: Int64
   public let y: Int64
@@ -84,4 +86,8 @@ public class MySwiftClass {
   public func copy() -> MySwiftClass {
     return MySwiftClass(x: self.x, y: self.y)
   }
+
+  public func addXWithJavaLong(_ other: JavaLong) -> Int64 {
+    return self.x + other.longValue()
+  }
 }

Samples/JExtractJNISampleApp/src/test/java/com/example/swift/MySwiftClassTest.java

@@ -139,4 +139,13 @@ void copy() {
             assertNotEquals(c1.$memoryAddress(), c2.$memoryAddress());
         }
     }
+
+    @Test
+    void addXWithJavaLong() {
+        try (var arena = new ConfinedSwiftMemorySession()) {
+            MySwiftClass c1 = MySwiftClass.init(20, 10, arena);
+            Long javaLong = 50L;
+            assertEquals(70, c1.addXWithJavaLong(javaLong));
+        }
+    }
 }

Sources/JExtractSwiftLib/Convenience/String+Extensions.swift

@@ -12,6 +12,8 @@
 //
 //===----------------------------------------------------------------------===//
 
+import JavaTypes
+
 extension String {
 
   var firstCharacterUppercased: String {
@@ -31,4 +33,41 @@ extension String {
     let thirdCharacterIndex = self.index(self.startIndex, offsetBy: 2)
     return self[thirdCharacterIndex].isUppercase
   }
+
+  /// Returns a version of the string correctly escaped for a JNI
+  var escapedJNIIdentifier: String {
+    self.map {
+      if $0 == "_" {
+        return "_1"
+      } else if $0 == "/" {
+        return "_"
+      } else if $0 == ";" {
+        return "_2"
+      } else if $0 == "[" {
+        return "_3"
+      } else if $0.isASCII && ($0.isLetter || $0.isNumber)  {
+        return String($0)
+      } else if let utf16 = $0.utf16.first {
+        // Escape any non-alphanumeric to their UTF16 hex encoding
+        let utf16Hex = String(format: "%04x", utf16)
+        return "_0\(utf16Hex)"
+      } else {
+        fatalError("Invalid JNI character: \($0)")
+      }
+    }
+    .joined()
+  }
+
+  /// Looks up self as a JavaKit wrapped class name and converts it
+  /// into a `JavaType.class` if it exists in `lookupTable`.
+  func parseJavaClassFromJavaKitName(in lookupTable: [String: String]) -> JavaType? {
+    guard let canonicalJavaName = lookupTable[self] else {
+      return nil
+    }
+    let nameParts = canonicalJavaName.components(separatedBy: ".")
+    let javaPackageName = nameParts.dropLast().joined(separator: ".")
+    let javaClassName = nameParts.last!
+
+    return .class(package: javaPackageName, name: javaClassName)
+  }
 }

Sources/JExtractSwiftLib/JNI/JNISwift2JavaGenerator+JavaTranslation.swift

@@ -24,7 +24,11 @@ extension JNISwift2JavaGenerator {
 
     let translated: TranslatedFunctionDecl?
     do {
-      let translation = JavaTranslation(swiftModuleName: swiftModuleName, javaPackage: self.javaPackage)
+      let translation = JavaTranslation(
+        swiftModuleName: swiftModuleName,
+        javaPackage: self.javaPackage,
+        javaClassLookupTable: self.javaClassLookupTable
+      )
       translated = try translation.translate(decl)
     } catch {
       self.logger.debug("Failed to translate: '\(decl.swiftDecl.qualifiedNameForDebug)'; \(error)")
@@ -38,9 +42,13 @@ extension JNISwift2JavaGenerator {
   struct JavaTranslation {
     let swiftModuleName: String
     let javaPackage: String
+    let javaClassLookupTable: JavaClassLookupTable
 
     func translate(_ decl: ImportedFunc) throws -> TranslatedFunctionDecl {
-      let nativeTranslation = NativeJavaTranslation(javaPackage: self.javaPackage)
+      let nativeTranslation = NativeJavaTranslation(
+        javaPackage: self.javaPackage,
+        javaClassLookupTable: self.javaClassLookupTable
+      )
 
       // Types with no parent will be outputted inside a "module" class.
       let parentName = decl.parentType?.asNominalType?.nominalTypeDecl.qualifiedName ?? swiftModuleName
@@ -157,6 +165,8 @@ extension JNISwift2JavaGenerator {
     ) throws -> TranslatedParameter {
       switch swiftType {
       case .nominal(let nominalType):
+        let nominalTypeName = nominalType.nominalTypeDecl.name
+
         if let knownType = nominalType.nominalTypeDecl.knownTypeKind {
           guard let javaType = JNISwift2JavaGenerator.translate(knownType: knownType) else {
             throw JavaTranslationError.unsupportedSwiftType(swiftType)
@@ -168,11 +178,25 @@ extension JNISwift2JavaGenerator {
           )
         }
 
-        // For now, we assume this is a JExtract class.
+        if nominalType.isJavaKitWrapper {
+          guard let javaType = nominalTypeName.parseJavaClassFromJavaKitName(in: self.javaClassLookupTable) else {
+            throw JavaTranslationError.wrappedJavaClassTranslationNotProvided(swiftType)
+          }
+
+          return TranslatedParameter(
+            parameter: JavaParameter(
+              name: parameterName,
+              type: javaType
+            ),
+            conversion: .placeholder
+          )
+        }
+
+        // We assume this is a JExtract class.
         return TranslatedParameter(
           parameter: JavaParameter(
             name: parameterName,
-            type: .class(package: nil, name: nominalType.nominalTypeDecl.name)
+            type: .class(package: nil, name: nominalTypeName)
           ),
           conversion: .valueMemoryAddress(.placeholder)
         )
@@ -213,7 +237,11 @@ extension JNISwift2JavaGenerator {
           )
         }
 
-        // For now, we assume this is a JExtract class.
+        if nominalType.isJavaKitWrapper {
+          throw JavaTranslationError.unsupportedSwiftType(swiftResult.type)
+        }
+
+        // We assume this is a JExtract class.
         let javaType = JavaType.class(package: nil, name: nominalType.nominalTypeDecl.name)
         return TranslatedResult(
           javaType: javaType,
@@ -350,5 +378,9 @@ extension JNISwift2JavaGenerator {
 
   enum JavaTranslationError: Error {
     case unsupportedSwiftType(SwiftType)
+
+    /// The user has not supplied a mapping from `SwiftType` to
+    /// a java class.
+    case wrappedJavaClassTranslationNotProvided(SwiftType)
   }
 }

Sources/JExtractSwiftLib/JNI/JNISwift2JavaGenerator+NativeTranslation.swift

@@ -18,6 +18,7 @@ extension JNISwift2JavaGenerator {
 
   struct NativeJavaTranslation {
     let javaPackage: String
+    let javaClassLookupTable: JavaClassLookupTable
 
     /// Translates a Swift function into the native JNI method signature.
     func translate(
@@ -62,10 +63,12 @@ extension JNISwift2JavaGenerator {
       swiftParameter: SwiftParameter,
       parameterName: String,
       methodName: String,
-      parentName: String,
+      parentName: String
     ) throws -> NativeParameter {
       switch swiftParameter.type {
       case .nominal(let nominalType):
+        let nominalTypeName = nominalType.nominalTypeDecl.name
+
         if let knownType = nominalType.nominalTypeDecl.knownTypeKind {
           guard let javaType = JNISwift2JavaGenerator.translate(knownType: knownType), javaType.implementsJavaValue else {
             throw JavaTranslationError.unsupportedSwiftType(swiftParameter.type)
@@ -78,6 +81,25 @@ extension JNISwift2JavaGenerator {
           )
         }
 
+        if nominalType.isJavaKitWrapper {
+          guard let javaType = nominalTypeName.parseJavaClassFromJavaKitName(in: self.javaClassLookupTable) else {
+            throw JavaTranslationError.wrappedJavaClassTranslationNotProvided(swiftParameter.type)
+          }
+
+          return NativeParameter(
+            name: parameterName,
+            javaType: javaType,
+            conversion: .initializeJavaKitWrapper(wrapperName: nominalTypeName)
+          )
+        }
+
+        // JExtract classes are passed as the pointer.
+        return NativeParameter(
+          name: parameterName,
+          javaType: .long,
+          conversion: .pointee(.extractSwiftValue(.placeholder, swiftType: swiftParameter.type))
+        )
+
       case .tuple([]):
         return NativeParameter(
           name: parameterName,
@@ -110,13 +132,6 @@ extension JNISwift2JavaGenerator {
       case .metatype, .optional, .tuple, .existential, .opaque:
         throw JavaTranslationError.unsupportedSwiftType(swiftParameter.type)
       }
-
-      // Classes are passed as the pointer.
-      return NativeParameter(
-        name: parameterName,
-        javaType: .long,
-        conversion: .pointee(.extractSwiftValue(.placeholder, swiftType: swiftParameter.type))
-      )
     }
 
     func translateClosureResult(
@@ -193,6 +208,15 @@ extension JNISwift2JavaGenerator {
           )
         }
 
+        if nominalType.isJavaKitWrapper {
+          throw JavaTranslationError.unsupportedSwiftType(swiftResult.type)
+        }
+
+        return NativeResult(
+          javaType: .long,
+          conversion: .getJNIValue(.allocateSwiftValue(name: "result", swiftType: swiftResult.type))
+        )
+
       case .tuple([]):
         return NativeResult(
           javaType: .void,
@@ -203,13 +227,7 @@ extension JNISwift2JavaGenerator {
         throw JavaTranslationError.unsupportedSwiftType(swiftResult.type)
       }
 
-      // TODO: Handle other classes, for example from JavaKit macros.
-      // for now we assume all passed in classes are JExtract generated
-      // so we pass the pointer.
-      return NativeResult(
-        javaType: .long,
-        conversion: .getJNIValue(.allocateSwiftValue(name: "result", swiftType: swiftResult.type))
-      )
+
     }
   }
 
@@ -262,6 +280,8 @@ extension JNISwift2JavaGenerator {
 
     indirect case closureLowering(parameters: [NativeParameter], result: NativeResult)
 
+    case initializeJavaKitWrapper(wrapperName: String)
+
     /// 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.
@@ -348,6 +368,9 @@ extension JNISwift2JavaGenerator {
         printer.print("}")
 
         return printer.finalize()
+
+      case .initializeJavaKitWrapper(let wrapperName):
+        return "\(wrapperName)(javaThis: \(placeholder), environment: environment!)"
       }
     }
   }