WIP start introducing jextract mode in swift-java tool

Author: ktoso

Package.swift

@@ -337,6 +337,7 @@ let package = Package(
         "JavaKitJar",
         "JavaKitNetwork",
         "SwiftJavaLib",
+        "JExtractSwiftLib",
         "JavaKitShared",
       ],
 
@@ -367,7 +368,7 @@ let package = Package(
       name: "JExtractSwiftPlugin",
       capability: .buildTool(),
       dependencies: [
-        "JExtractSwiftTool"
+        "SwiftJavaTool"
       ]
     ),
     .plugin(
@@ -377,7 +378,7 @@ let package = Package(
         permissions: [
         ]),
       dependencies: [
-        "JExtractSwiftTool"
+        "SwiftJavaTool"
       ]
     ),
 

Plugins/JExtractSwiftCommandPlugin/JExtractSwiftCommandPlugin.swift

@@ -130,7 +130,7 @@ final class JExtractSwiftCommandPlugin: SwiftJavaPluginProtocol, BuildToolPlugin
 
   func runExtract(context: PluginContext, target: Target, arguments: [String]) throws {
     let process = Process()
-    process.executableURL = try context.tool(named: "JExtractSwiftTool").url
+    process.executableURL = try context.tool(named: "SwiftJavaTool").url
     process.arguments = arguments
 
     do {

Plugins/JExtractSwiftPlugin/JExtractSwiftPlugin.swift

@@ -22,7 +22,7 @@ struct JExtractSwiftBuildToolPlugin: SwiftJavaPluginProtocol, BuildToolPlugin {
   var verbose: Bool = getEnvironmentBool("SWIFT_JAVA_VERBOSE")
 
   func createBuildCommands(context: PluginContext, target: Target) throws -> [Command] {
-    let toolURL = try context.tool(named: "JExtractSwiftTool").url
+    let toolURL = try context.tool(named: "SwiftJavaTool").url
 
     guard let sourceModule = target.sourceModule else { return [] }
 

Sources/JavaKitConfigurationShared/Configuration.swift

@@ -27,6 +27,10 @@ public struct Configuration: Codable {
 
   public var javaPackage: String?
 
+  public var inputSwift: String?
+  public var outputSwift: String?
+  public var outputJava: String?
+
   // ==== java 2 swift ---------------------------------------------------------
 
   /// The Java class path that should be passed along to the Java2Swift tool.

Sources/SwiftJavaTool/JExtractSwiftTool.swift renamed to Sources/SwiftJavaTool/SwiftJava+JExtract.swift

@@ -12,12 +12,29 @@
 //
 //===----------------------------------------------------------------------===//
 
+import Foundation
+import ArgumentParser
+import SwiftJavaLib
+import JavaKit
+import JavaKitJar
+import SwiftJavaLib
 import JExtractSwiftLib
+import JavaKitConfigurationShared
+
+/// Extract Java bindings from Swift sources or interface files.
+///
+/// Example usage:
+/// ```
+/// > swift-java --input-swift Sources/SwiftyBusiness \
+///              --output-swift .build/.../outputs/SwiftyBusiness \
+///              --output-Java .build/.../outputs/Java
+/// ```
+extension SwiftJava {
+
+  mutating func jextractSwift(
+    config: Configuration
+  ) throws {
 
-@main
-struct JExtractSwift {
-  static func main() throws {
-    let command = SwiftToJava.parseOrExit(CommandLine.arguments)
-    try command.run()
   }
+
 }

Sources/SwiftJavaTool/SwiftJava.swift

@@ -59,10 +59,19 @@ struct SwiftJava: AsyncParsableCommand {
   )
   var swiftNativeImplementation: [String] = []
 
-  @Option(name: .shortAndLong, help: "The directory in which to output the generated Swift files or the Java2Swift configuration file.")
+  @Option(name: .shortAndLong, help: "Directory containing Swift files which should be extracted into Java bindings. Also known as 'jextract' mode. Must be paired with --output-java and --output-swift.")
+  var inputSwift: String? = nil
+
+  @Option(name: .shortAndLong, help: "The directory where generated Swift files should be written. Generally used with jextract mode.")
+  var outputSwift: String? = nil
+
+  @Option(name: .shortAndLong, help: "The directory where generated Java files should be written. Generally used with jextract mode.")
+  var outputJava: String? = nil
+
+  // TODO: clarify this vs outputSwift (history: outputSwift is jextract, and this was java2swift)
+  @Option(name: .shortAndLong, help: "The directory in which to output the generated Swift files or the SwiftJava configuration file.")
   var outputDirectory: String? = nil
 
-  
   @Option(name: .shortAndLong, help: "Directory where to write cached values (e.g. swift-java.classpath files)")
   var cacheDirectory: String? = nil
 
@@ -87,8 +96,7 @@ struct SwiftJava: AsyncParsableCommand {
   var javaPackageFilter: String? = nil
 
   @Argument(
-    help:
-      "The input file, which is either a Java2Swift configuration file or (if '-jar' was specified) a Jar file."
+    help: "The input file, which is either a Java2Swift configuration file or (if '-jar' was specified) a Jar file."
   )
   var input: String
 
@@ -163,6 +171,9 @@ struct SwiftJava: AsyncParsableCommand {
 
     /// Fetch dependencies for a module
     case fetchDependencies
+
+    /// Extract Java bindings from provided Swift sources.
+    case jextract // TODO: carry jextract specific config here?
   }
 
   mutating func run() async {
@@ -172,7 +183,24 @@ struct SwiftJava: AsyncParsableCommand {
 
       // Determine the mode in which we'll execute.
       let toolMode: ToolMode
-      if jar {
+      // TODO: some options are exclusive to eachother so we should detect that
+      if let inputSwift {
+        guard let outputSwift else {
+          print("[swift-java] --input-swift enabled 'jextract' mode, however no --output-swift directory was provided!")
+          return
+        }
+        guard let outputJava else {
+          print("[swift-java] --input-swift enabled 'jextract' mode, however no --output-java directory was provided!")
+          return
+        }
+        var c = Configuration()
+        c.inputSwift = inputSwift
+        c.outputSwift = outputSwift
+        c.outputJava = outputJava
+        config = c
+
+        toolMode = .jextract
+      } else if jar {
         if let moduleBaseDir {
           config = try readConfiguration(sourceDir: moduleBaseDir.path)
         } else {
@@ -251,7 +279,7 @@ struct SwiftJava: AsyncParsableCommand {
 //          print("[debug][swift-java] Found cached dependency resolver classpath: \(dependencyResolverClasspath)")
 //          classpathEntries += dependencyResolverClasspath
 //        }
-      case .classWrappers:
+      case .classWrappers, .jextract:
         break;
       }
 
@@ -310,6 +338,9 @@ struct SwiftJava: AsyncParsableCommand {
           moduleName: moduleName,
           cacheDir: effectiveCacheDirectory,
           resolvedClasspath: dependencyClasspath)
+
+        case .jextract:
+          try jextractSwift(config: config)
       }
     } catch {
       // We fail like this since throwing out of the run often ends up hiding the failure reason when it is executed as SwiftPM plugin (!)