gradle build now causes proper emission of the swift/java sources

Author: ktoso

Plugins/JExtractSwiftCommandPlugin/JExtractSwiftCommandPlugin.swift

@@ -20,6 +20,16 @@ final class JExtractSwiftCommandPlugin: BuildToolPlugin, CommandPlugin {
 
   var verbose: Bool = false
 
+  /// Build the target before attempting to extract from it.
+  /// This avoids trying to extract from broken sources.
+  ///
+  /// You may disable this if confident that input targets sources are correct and there's no need to kick off a pre-build for some reason.
+  var buildInputs: Bool = true
+  
+  /// Build the target once swift-java sources have been generated.
+  /// This helps verify that the generated output is correct, and won't miscompile on the next build.
+  var buildOutputs: Bool = true
+  
   func createBuildCommands(context: PackagePlugin.PluginContext, target: any PackagePlugin.Target) async throws -> [PackagePlugin.Command] {
     // FIXME: This is not a build plugin but SwiftPM forces us to impleme the protocol anyway? rdar://139556637
     return []
@@ -37,7 +47,7 @@ final class JExtractSwiftCommandPlugin: BuildToolPlugin, CommandPlugin {
       }
 
     for target in context.package.targets {
-      guard hasSwiftJavaConfig(target: target) else {
+      guard let configPath = getSwiftJavaConfig(target: target) else {
         log("Skipping target '\(target.name), has no 'swift-java.config' file")
         continue
       }
@@ -58,6 +68,16 @@ final class JExtractSwiftCommandPlugin: BuildToolPlugin, CommandPlugin {
 
     guard let sourceModule = target.sourceModule else { return }
 
+    if self.buildInputs {
+      log("Pre-building target '\(target.name)' before extracting sources...")
+      try self.packageManager.build(.target(target.name), parameters: .init())
+    }
+    
+    if self.buildOutputs {
+      log("Post-building target '\(target.name)' to verify generated sources...")
+      try self.packageManager.build(.target(target.name), parameters: .init())
+    }
+    
     // Note: Target doesn't have a directoryURL counterpart to directory,
     // so we cannot eliminate this deprecation warning.
     let sourceDir = target.directory.string
@@ -87,8 +107,6 @@ final class JExtractSwiftCommandPlugin: BuildToolPlugin, CommandPlugin {
     ]
     arguments.append(sourceDir)
 
-    print("PLUGIN: jextract \(arguments.joined(separator: " "))")
-    
     try runExtract(context: context, target: target, arguments: arguments)
   }
 
@@ -98,6 +116,8 @@ final class JExtractSwiftCommandPlugin: BuildToolPlugin, CommandPlugin {
     process.arguments = arguments
 
     do {
+      log("Execute: \(process.executableURL) \(arguments)")
+      
       try process.run()
       process.waitUntilExit()
 
@@ -107,7 +127,7 @@ final class JExtractSwiftCommandPlugin: BuildToolPlugin, CommandPlugin {
     }
   }
 
-  func log(message: @autoclosure () -> String) {
+  func log(_ message: @autoclosure () -> String) {
     if self.verbose {
       print("[swift-java] \(message())")
     }

Plugins/JExtractSwiftCommandPlugin/PluginsShared/Configuration.swift

@@ -21,7 +21,7 @@ struct Configuration: Codable {
 }
 
 func readConfiguration(sourceDir: String) throws -> Configuration {
-  let configFile = URL(filePath: sourceDir).appending(path: "JExtractSwift.config")
+  let configFile = URL(filePath: sourceDir).appending(path: "swift-java.config")
   do {
     let configData = try Data(contentsOf: configFile)
     return try JSONDecoder().decode(Configuration.self, from: configData)

Plugins/JExtractSwiftCommandPlugin/PluginsShared/PluginUtils.swift

@@ -22,21 +22,27 @@ func findJavaHome() -> String {
   if let home = ProcessInfo.processInfo.environment["JAVA_HOME"] {
     return home
   }
-
+  
   // This is a workaround for envs (some IDEs) which have trouble with
   // picking up env variables during the build process
   let path = "\(FileManager.default.homeDirectoryForCurrentUser.path()).java_home"
   if let home = try? String(contentsOfFile: path, encoding: .utf8) {
     if let lastChar = home.last, lastChar.isNewline {
       return String(home.dropLast())
     }
-
+    
     return home
   }
-
+  
   fatalError("Please set the JAVA_HOME environment variable to point to where Java is installed.")
 }
 
-func hasSwiftJavaConfig(target: Target) -> Bool {
-  target.directory
+func getSwiftJavaConfig(target: Target) -> String? {
+  let configPath = URL(fileURLWithPath: target.directory.string).appending(component: "swift-java.config").path()
+  
+  if FileManager.default.fileExists(atPath: configPath) {
+    return    configPath
+  } else {
+    return nil
+  }
 }

Plugins/JExtractSwiftPlugin/PluginsShared/Configuration.swift

@@ -21,7 +21,7 @@ struct Configuration: Codable {
 }
 
 func readConfiguration(sourceDir: String) throws -> Configuration {
-  let configFile = URL(filePath: sourceDir).appending(path: "JExtractSwift.config")
+  let configFile = URL(filePath: sourceDir).appending(path: "swift-java.config")
   do {
     let configData = try Data(contentsOf: configFile)
     return try JSONDecoder().decode(Configuration.self, from: configData)

Samples/JExtractPluginSampleApp/Sources/JExtractPluginSampleLib/JExtractSwift.config renamed to Samples/JExtractPluginSampleApp/Sources/JExtractPluginSampleLib/swift-java.config

@@ -49,7 +49,7 @@ def buildJExtractPlugin = tasks.register("swiftBuildJExtractPlugin", Exec) {
     args "build"
 }
 
-def buildSwift = tasks.register("swiftBuildProject", Exec) {
+def jextract = tasks.register("jextract", Exec) {
     description = "Builds swift sources, including swift-java source generation"
     dependsOn buildJExtractPlugin
 
@@ -76,14 +76,14 @@ def buildSwift = tasks.register("swiftBuildProject", Exec) {
 
     workingDir = layout.projectDirectory
     commandLine "swift"
-    args "build"
+    args("package", "jextract")
 }
 
 // Add the java-swift generated Java sources
 sourceSets {
     main {
         java {
-            srcDir(buildSwift)
+            srcDir(jextract)
         }
     }
 }

Samples/JExtractPluginSampleApp/build.gradle

@@ -22,7 +22,15 @@ public static void main(String[] args) {
         System.out.println("java.library.path = " + SwiftKit.getJavaLibraryPath());
         System.out.println("jextract.trace.downcalls = " + SwiftKit.getJextractTraceDowncalls());
 
-        var o = new MyCoolSwiftClass(12);
-        o.exposedToJava();
+        try {
+            var o = new MyCoolSwiftClass(12);
+            o.exposedToJava();
+        } catch (UnsatisfiedLinkError linkError) {
+            if (linkError.getMessage().startsWith("unresolved symbol: ")) {
+                var unresolvedSymbolName = linkError.getMessage().substring("unresolved symbol: ".length());
+
+
+            }
+        }
     }
 }

Samples/JExtractPluginSampleApp/src/main/java/com/example/swift/JExtractPluginSampleMain.java

@@ -75,7 +75,7 @@ def buildSwift = tasks.register("swiftBuildProject", Exec) {
 
     workingDir = layout.projectDirectory
     commandLine "swift"
-    args "build"
+    args ["package", "jextract"]
 }
 
 // Add the java-swift generated Java sources

Samples/SwiftKitSampleApp/build.gradle

@@ -40,13 +40,13 @@ public struct CodePrinter {
     return printer.finalize()
   }
 
-  var ioMode: PrintMode
+  var mode: PrintMode
   public enum PrintMode {
     case accumulateAll
     case flushToFileOnWrite
   }
-  public init(io: PrintMode = .flushToFileOnWrite) {
-    self.ioMode = .accumulateAll
+  public init(mode: PrintMode = .flushToFileOnWrite) {
+    self.mode = mode
   }
 
   internal mutating func append(_ text: String) {
@@ -208,16 +208,18 @@ public enum PrinterTerminator: String {
 }
 
 extension CodePrinter {
+  
+  /// - Returns: the output path of the generated file, if any (i.e. not in accumulate in memory mode)
   package mutating func writeContents(
     outputDirectory: String,
     javaPackagePath: String?,
     filename: String
-  ) throws {
-    guard self.ioMode != .accumulateAll else {
+  ) throws -> URL? {
+    guard self.mode != .accumulateAll else {
       // if we're accumulating everything, we don't want to finalize/flush any contents
       // let's mark that this is where a write would have happened though:
       print("// ^^^^ Contents of: \(outputDirectory)/\(filename)")
-      return
+      return nil
     }
 
     let contents = finalize()
@@ -231,24 +233,22 @@ extension CodePrinter {
         print("// \(filename)")
       }
       print(contents)
-      return
+      return nil
     }
 
-    let targetDirectory = [outputDirectory, javaPackagePath].compactMap { $0 }.joined(
-        separator: PATH_SEPARATOR)
+    let targetDirectory = [outputDirectory, javaPackagePath].compactMap { $0 }.joined(separator: PATH_SEPARATOR)
     log.trace("Prepare target directory: \(targetDirectory)")
     try FileManager.default.createDirectory(
       atPath: targetDirectory, withIntermediateDirectories: true)
 
-    let targetFilePath = [javaPackagePath, filename].compactMap { $0 }.joined(
-        separator: PATH_SEPARATOR)
-  Swift.print("Writing '\(targetFilePath)'...", terminator: "")
+    let outputPath = Foundation.URL(fileURLWithPath: targetDirectory).appendingPathComponent(filename)
     try contents.write(
-      to: Foundation.URL(fileURLWithPath: targetDirectory).appendingPathComponent(filename),
+      to: outputPath,
       atomically: true,
       encoding: .utf8
     )
-    Swift.print(" done.".green)
+    
+    return outputPath
   }
 
-}
+}

Sources/JExtractSwift/CodePrinter.swift

@@ -95,14 +95,14 @@ public struct Logger {
 }
 
 extension Logger {
-  public enum Level: Int, Hashable {
-    case trace = 0
-    case debug = 1
-    case info = 2
-    case notice = 3
-    case warning = 4
-    case error = 5
-    case critical = 6
+  public enum Level: String, Hashable {
+    case trace = "trace"
+    case debug = "debug"
+    case info = "info"
+    case notice = "notice"
+    case warning = "warning"
+    case error = "error"
+    case critical = "critical"
   }
 }