Compilation error for generic class with async function: Missing 'selfTypePointer$'

[vgritsenko]

Commit hash: 0dd772b

Context:
While testing swiftly's support of existing Swift code, noticed that a code using generic classes with async functions is not compiling. Source code without generics, or without async functions, can be compiled; code that uses both fails to compile with "cannot find 'selfTypePointer$' in scope" error. Looks like it's trying to pass non-existent selfTypePointer$ into the Task, but it is left unused after that.

import Foundation

public final class Tester<T: Comparable>: Sendable {
    public func fetch() async { }
}

Results in the following compilation error:

.../.build/plugins/outputs/lib/SwiftTestLib/destination/JExtractSwiftPlugin/Sources/Sample+SwiftJava.swift:35:56: error: cannot find 'selfTypePointer$' in scope
 33 |     nonisolated(unsafe) let globalFuture = environment.interface.NewGlobalRef(environment, result_future)
 34 |     nonisolated(unsafe) let selfPointerSendable$ = selfPointer$
 35 |     nonisolated(unsafe) let selfTypePointerSendable$ = selfTypePointer$
    |                                                        `- error: cannot find 'selfTypePointer$' in scope
 36 |     var task: Task<Void, Never>? = nil
 37 |     #if swift(>=6.2)

Portion of the generated swift file:

extension Tester: _SwiftTestLib_Tester_opener {
  static func _fetch(environment: UnsafeMutablePointer<JNIEnv?>!, thisClass: jclass, selfPointer: jlong, result_future: jobject?) {
    assert(selfPointer != 0, "selfPointer memory address was null")
    let selfPointerBits$ = Int(Int64(fromJNI: selfPointer, in: environment))
    let selfPointer$ = UnsafeMutablePointer<Tester<T>>(bitPattern: selfPointerBits$)
    guard let selfPointer$ else {
      fatalError("selfPointer memory address was null in call to \(#function)!")
    }
    nonisolated(unsafe) let globalFuture = environment.interface.NewGlobalRef(environment, result_future)
    nonisolated(unsafe) let selfPointerSendable$ = selfPointer$
    nonisolated(unsafe) let selfTypePointerSendable$ = selfTypePointer$
    var task: Task<Void, Never>? = nil
    #if swift(>=6.2)
      if #available(macOS 26.0, iOS 26.0, watchOS 26.0, tvOS 26.0, *) {
        task = Task.immediate {
          var environment = try! JavaVirtualMachine.shared().environment()
          let selfPointer$ = selfPointerSendable$
          let selfTypePointer$ = selfTypePointerSendable$
          defer {
            let deferEnvironment = try! JavaVirtualMachine.shared().environment()
            deferEnvironment.interface.DeleteGlobalRef(deferEnvironment, globalFuture)
          } // printTaskBody(printer:) @ JExtractSwiftLib/JNISwift2JavaGenerator+NativeTranslation.swift:2017
          await selfPointer$.pointee.fetch()
          environment = try! JavaVirtualMachine.shared().environment()
          _ = environment.interface.CallBooleanMethodA(environment, globalFuture, _JNIMethodIDCache.CompletableFuture.complete, [jvalue(l: nil)])
        } // render(_:_:) @ JExtractSwiftLib/JNISwift2JavaGenerator+NativeTranslation.swift:2046
      } // render(_:_:) @ JExtractSwiftLib/JNISwift2JavaGenerator+NativeTranslation.swift:2045
    #endif // end of swift(>=6.2) // render(_:_:) @ JExtractSwiftLib/JNISwift2JavaGenerator+NativeTranslation.swift:2044
    if task == nil {
      task = Task {
        var environment = try! JavaVirtualMachine.shared().environment()
        let selfPointer$ = selfPointerSendable$
        let selfTypePointer$ = selfTypePointerSendable$
        defer {
          let deferEnvironment = try! JavaVirtualMachine.shared().environment()
          deferEnvironment.interface.DeleteGlobalRef(deferEnvironment, globalFuture)
        } // printTaskBody(printer:) @ JExtractSwiftLib/JNISwift2JavaGenerator+NativeTranslation.swift:2017
        await selfPointer$.pointee.fetch()
        environment = try! JavaVirtualMachine.shared().environment()
        _ = environment.interface.CallBooleanMethodA(environment, globalFuture, _JNIMethodIDCache.CompletableFuture.complete, [jvalue(l: nil)])
      } // render(_:_:) @ JExtractSwiftLib/JNISwift2JavaGenerator+NativeTranslation.swift:2055
    } // render(_:_:) @ JExtractSwiftLib/JNISwift2JavaGenerator+NativeTranslation.swift:2054
    
  } // printFunctionDecl(_:decl:skipMethodBody:) @ JExtractSwiftLib/JNISwift2JavaGenerator+SwiftThunkPrinting.swift:1159
} // printOpenerProtocol(_:_:) @ JExtractSwiftLib/JNISwift2JavaGenerator+SwiftThunkPrinting.swift:1177

Environment: Swift 6.3.3 on macOS.

$ swiftly run swift --version
Apple Swift version 6.3.3 (swift-6.3.3-RELEASE)
Target: arm64-apple-macosx26.0

$ uname -a
Darwin it-C01241 25.6.0 Darwin Kernel Version 25.6.0: Sat Jul 11 15:26:21 PDT 2026; root:xnu-12377.161.13~4/RELEASE_ARM64_T6000 arm64