jextract: Allow importing internal decls

Sources/JExtractSwiftLib/Convenience/SwiftSyntax+Extensions.swift

@@ -51,23 +51,76 @@ extension DeclModifierSyntax {
 extension DeclModifierSyntax {
   var isPublic: Bool {
     switch self.name.tokenKind {
-    case .keyword(.private): return false
-    case .keyword(.fileprivate): return false
-    case .keyword(.internal): return false
-    case .keyword(.package): return false
-    case .keyword(.public): return true
-    case .keyword(.open): return true
-    default: return false
+    case .keyword(.private): false
+    case .keyword(.fileprivate): false
+    case .keyword(.internal): false
+    case .keyword(.package): false
+    case .keyword(.public): true
+    case .keyword(.open): true
+    default: false
     }
   }
+
+  var isPackage: Bool {
+    switch self.name.tokenKind {
+    case .keyword(.private): false
+    case .keyword(.fileprivate): false
+    case .keyword(.internal): false
+    case .keyword(.package): true
+    case .keyword(.public): false
+    case .keyword(.open): false
+    default: false
+    }
+  }
+
+  var isAtLeastPackage: Bool {
+    isPackage || isPublic
+  }
+
+  var isInternal: Bool {
+    return switch self.name.tokenKind {
+    case .keyword(.private): false
+    case .keyword(.fileprivate): false
+    case .keyword(.internal): true
+    case .keyword(.package): false
+    case .keyword(.public): false
+    case .keyword(.open): false
+    default: false
+    }
+  }
+
+  var isAtLeastInternal: Bool {
+    isInternal || isPackage || isPublic
+  }
 }
 
 extension WithModifiersSyntax {
   var isPublic: Bool {
-    self.modifiers.contains { modifier in
+    return self.modifiers.contains { modifier in
       modifier.isPublic
     }
   }
+
+  var isAtLeastPackage: Bool {
+    if self.modifiers.isEmpty {
+      return false
+    }
+
+    return self.modifiers.contains { modifier in
+      modifier.isAtLeastInternal
+    }
+  }
+
+  var isAtLeastInternal: Bool {
+    if self.modifiers.isEmpty {
+      // we assume that default access level is internal
+      return true
+    }
+
+    return self.modifiers.contains { modifier in
+      modifier.isAtLeastInternal
+    }
+  }
 }
 
 extension AttributeListSyntax.Element {

Sources/JExtractSwiftLib/Logger.swift

@@ -27,6 +27,23 @@ public struct Logger {
     self.logLevel = logLevel
   }
 
+  public func error(
+    _ message: @autoclosure () -> String,
+    metadata: [String: Any] = [:],
+    file: String = #fileID,
+    line: UInt = #line,
+    function: String = #function
+  ) {
+    guard logLevel <= .error else {
+      return
+    }
+
+    let metadataString: String =
+      if metadata.isEmpty { "" } else { "\(metadata)" }
+
+    print("[error][\(file):\(line)](\(function)) \(message()) \(metadataString)")
+  }
+
   public func warning(
     _ message: @autoclosure () -> String,
     metadata: [String: Any] = [:],

Sources/JExtractSwiftLib/Swift2JavaTranslator.swift

@@ -200,7 +200,7 @@ extension Swift2JavaTranslator {
     _ nominalNode: some DeclGroupSyntax & NamedDeclSyntax & WithModifiersSyntax & WithAttributesSyntax,
     parent: ImportedNominalType?
   ) -> ImportedNominalType? {
-    if !nominalNode.shouldImport(log: log) {
+    if !nominalNode.shouldExtract(config: config, log: log) {
       return nil
     }
 
@@ -225,7 +225,7 @@ extension Swift2JavaTranslator {
     guard swiftNominalDecl.moduleName == self.swiftModuleName else {
       return nil
     }
-    guard swiftNominalDecl.syntax!.shouldImport(log: log) else {
+    guard swiftNominalDecl.syntax!.shouldExtract(config: config, log: log) else {
       return nil
     }
 

Sources/JExtractSwiftLib/Swift2JavaVisitor.swift

@@ -15,9 +15,13 @@
 import Foundation
 import SwiftParser
 import SwiftSyntax
+import JavaKitConfigurationShared
 
 final class Swift2JavaVisitor {
   let translator: Swift2JavaTranslator
+  var config: Configuration {
+    self.translator.config
+  }
 
   init(translator: Swift2JavaTranslator) {
     self.translator = translator
@@ -48,7 +52,7 @@ final class Swift2JavaVisitor {
     case .extensionDecl(let node):
       self.visit(extensionDecl: node, in: parent)
     case .typeAliasDecl:
-      break // TODO: Implement
+      break // TODO: Implement; https://github.com/swiftlang/swift-java/issues/338
     case .associatedTypeDecl:
       break // TODO: Implement
 
@@ -93,7 +97,7 @@ final class Swift2JavaVisitor {
   }
 
   func visit(functionDecl node: FunctionDeclSyntax, in typeContext: ImportedNominalType?) {
-    guard node.shouldImport(log: log) else {
+    guard node.shouldExtract(config: config, log: log) else {
       return
     }
 
@@ -128,7 +132,7 @@ final class Swift2JavaVisitor {
   }
 
   func visit(variableDecl node: VariableDeclSyntax, in typeContext: ImportedNominalType?) {
-    guard node.shouldImport(log: log) else {
+    guard node.shouldExtract(config: config, log: log) else {
       return
     }
 
@@ -182,7 +186,7 @@ final class Swift2JavaVisitor {
       self.log.info("Initializer must be within a current type; \(node)")
       return
     }
-    guard node.shouldImport(log: log) else {
+    guard node.shouldExtract(config: config, log: log) else {
       return
     }
 
@@ -212,13 +216,20 @@ final class Swift2JavaVisitor {
 }
 
 extension DeclSyntaxProtocol where Self: WithModifiersSyntax & WithAttributesSyntax {
-  func shouldImport(log: Logger) -> Bool {
-    guard accessControlModifiers.contains(where: { $0.isPublic }) else {
-      log.trace("Skip import '\(self.qualifiedNameForDebug)': not public")
+  func shouldExtract(config: Configuration, log: Logger) -> Bool {
+    let meetsRequiredAccessLevel: Bool =
+      switch config.effectiveMinimumInputAccessLevelMode {
+      case .public: self.isPublic
+      case .package: self.isAtLeastPackage
+      case .internal: self.isAtLeastInternal
+      }
+
+    guard meetsRequiredAccessLevel else {
+      log.debug("Skip import '\(self.qualifiedNameForDebug)': not at least \(config.effectiveMinimumInputAccessLevelMode)")
       return false
     }
     guard !attributes.contains(where: { $0.isJava }) else {
-      log.trace("Skip import '\(self.qualifiedNameForDebug)': is Java")
+      log.debug("Skip import '\(self.qualifiedNameForDebug)': is Java")
       return false
     }
 

Sources/JavaKitConfigurationShared/Configuration.swift

@@ -46,6 +46,10 @@ public struct Configuration: Codable {
   public var effectiveUnsignedNumbersMode: JExtractUnsignedIntegerMode {
     unsignedNumbersMode ?? .default
   }
+  public var minimumInputAccessLevelMode: JExtractMinimumAccessLevelMode?
+  public var effectiveMinimumInputAccessLevelMode: JExtractMinimumAccessLevelMode {
+    minimumInputAccessLevelMode ?? .default
+  }
 
   // ==== java 2 swift ---------------------------------------------------------
 

Sources/JavaKitConfigurationShared/GenerationMode.swift

@@ -59,7 +59,20 @@ extension JExtractUnsignedIntegerMode {
     }
   }
 
-  public static var `default`: JExtractUnsignedIntegerMode {
+  public static var `default`: Self {
     .annotate
   }
 }
+
+/// The minimum access level which
+public enum JExtractMinimumAccessLevelMode: String, Codable {
+  case `public`
+  case `package`
+  case `internal`
+}
+
+extension JExtractMinimumAccessLevelMode {
+  public static var `default`: Self {
+    .public
+  }
+}

Sources/SwiftJavaTool/Commands/JExtractCommand.swift

@@ -64,6 +64,9 @@ extension SwiftJava {
     @Option(help: "The mode of generation to use for the output files. Used with jextract mode. By default, unsigned Swift types are imported as their bit-width compatible signed Java counterparts, and annotated using the '@Unsigned' annotation. You may choose the 'wrap-guava' mode in order to import types as class wrapper types (`UnsignedInteger` et al) defined by the Google Guava library's `com.google.common.primitives' package. that ensure complete type-safety with regards to unsigned values, however they incur an allocation and performance overhead.")
     var unsignedNumbers: JExtractUnsignedIntegerMode = .default
 
+    @Option(help: "The lowest access level of Swift declarations that should be extracted, defaults to 'public'.")
+    var minimumInputAccessLevel: JExtractMinimumAccessLevelMode = .default
+
     @Option(
       help: """
             A swift-java configuration file for a given Swift module name on which this module depends,
@@ -85,6 +88,7 @@ extension SwiftJava.JExtractCommand {
     config.outputSwiftDirectory = outputSwift
     config.writeEmptyFiles = writeEmptyFiles
     config.unsignedNumbersMode = unsignedNumbers
+    config.minimumInputAccessLevelMode = minimumInputAccessLevel
 
     try checkModeCompatibility()
 
@@ -143,3 +147,4 @@ struct IllegalModeCombinationError: Error {
 
 extension JExtractGenerationMode: ExpressibleByArgument {}
 extension JExtractUnsignedIntegerMode: ExpressibleByArgument {}
+extension JExtractMinimumAccessLevelMode: ExpressibleByArgument {}

Tests/JExtractSwiftTests/InternalExtractTests.swift

@@ -0,0 +1,49 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2024 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 JavaKitConfigurationShared
+import Testing
+
+final class InternalExtractTests {
+  let text =
+    """
+    internal func catchMeIfYouCan()
+    """
+
+  @Test("Import: internal decl if configured")
+  func data_swiftThunk() throws {
+    var config = Configuration()
+    config.minimumInputAccessLevelMode = .internal
+
+    try assertOutput(
+      input: text,
+      config: config,
+      .ffm, .java,
+      expectedChunks: [
+        """
+        /**
+         * Downcall to Swift:
+         * {@snippet lang=swift :
+         * internal func catchMeIfYouCan()
+         * }
+         */
+        public static void catchMeIfYouCan() {
+          swiftjava_SwiftModule_catchMeIfYouCan.call();
+        }
+        """,
+      ]
+    )
+  }
+}