// RUN: %target-typecheck-verify-swift -swift-version 5
// RUN: %target-typecheck-verify-swift -swift-version 5 -strict-concurrency=complete -verify-additional-prefix complete-

class NonSendable {} // expected-complete-note 3{{class 'NonSendable' does not conform to the 'Sendable' protocol}}

func callee(_: @Sendable () -> NonSendable) {}

var testLocalCaptures: Int {
  let ns = NonSendable()

  @Sendable func localFunc() -> NonSendable {
    return ns // expected-complete-warning {{capture of 'ns' with non-Sendable type 'NonSendable' in a '@Sendable' local function}}
  }

  callee { return ns } // expected-complete-warning {{capture of 'ns' with non-Sendable type 'NonSendable' in a '@Sendable' closure}}

  return 3
}

struct Bad {
  var c: Int = {
    let ns = NonSendable()
    callee { return ns } // expected-complete-warning {{capture of 'ns' with non-Sendable type 'NonSendable' in a '@Sendable' closure}}
    return 3
  }()
}

do {
  class Test { // expected-complete-note 2 {{class 'Test' does not conform to the 'Sendable' protocol}}
    func update() {}
  }

  func sendable(_: @Sendable () -> Void) {}

  @preconcurrency
  func sendable_preconcurrency(_: @Sendable () -> Void) {}
  
  func withMutable(_: (inout Test) -> Void) {}

  withMutable { test in
    sendable {
      test.update()
      // expected-complete-warning@-1 {{capture of 'test' with non-Sendable type 'Test' in a '@Sendable' closure}}
      // expected-warning@-2 {{mutable capture of 'inout' parameter 'test' is not allowed in concurrently-executing code}}
    }

    sendable_preconcurrency {
      test.update()
      // expected-complete-warning@-1 {{capture of 'test' with non-Sendable type 'Test' in a '@Sendable' closure}}
      // expected-complete-warning@-2 {{mutable capture of 'inout' parameter 'test' is not allowed in concurrently-executing code}}
    }
  }
}

class NotSendable {} // expected-complete-note {{class 'NotSendable' does not conform to the 'Sendable' protocol}}

@available(*, unavailable)
extension NotSendable : @unchecked Sendable {}

@preconcurrency func withSendableClosure(_: @Sendable () -> Void) {}

func testPreconcurrencyDowngrade(ns: NotSendable) {
  var x = 0
  withSendableClosure {
    _ = ns
    // expected-complete-warning@-1 {{capture of 'ns' with non-Sendable type 'NotSendable' in a '@Sendable' closure}}

    x += 1
    // expected-complete-warning@-1 {{mutation of captured var 'x' in concurrently-executing code}}
  }
}

// rdar://136766795
do {
  class Class {
    static func test() -> @Sendable () -> Void {
      {
        // OK, an unbound reference is sendable.
        let _ = Class.method
      }
    }

    func method() {}
  }
}

do {
  class Class {}
  // expected-complete-note@-1 {{class 'Class' does not conform to the 'Sendable' protocol}}

  func test(_: @autoclosure @Sendable () -> Class) {}

  let c: Class
  test(c)
  // expected-complete-warning@-1:8 {{implicit capture of 'c' requires that 'Class' conforms to 'Sendable'; this is an error in the Swift 6 language mode}}
}