From 2c245b3d7d73ee4e7de0a4daff40da2a874e3ac2 Mon Sep 17 00:00:00 2001
From: Pavel Yaskevich <pyaskevich@apple.com>
Date: Sat, 10 Nov 2018 23:31:42 -0800
Subject: [PATCH 1/2] [TypeChecker] NFC: Add a couple of test-cases related to
 rdar://problem/20591571

---
 test/attr/attr_autoclosure.swift | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/test/attr/attr_autoclosure.swift b/test/attr/attr_autoclosure.swift
index e646a61403f75..39d70a732309f 100644
--- a/test/attr/attr_autoclosure.swift
+++ b/test/attr/attr_autoclosure.swift
@@ -175,3 +175,31 @@ func passNonThrowingToThrowingAC(_ fn: @autoclosure () -> Int) {
 func passThrowingToThrowingAC(_ fn: @autoclosure () throws -> Int) {
   takesThrowingAutoclosure(fn)
 }
+
+// rdar://problem/20591571 - Various type inference problems with @autoclosure
+func rdar_20591571() {
+  func foo(_ g: @autoclosure () -> Int) {
+    typealias G = ()->Int
+    let _ = unsafeBitCast(g, to: G.self) // expected-error {{converting non-escaping value to 'T' may allow it to escape}}
+  }
+
+  func id<T>(_: T) -> T {}
+  func same<T>(_: T, _: T) {}
+
+  func takesAnAutoclosure(_ fn: @autoclosure () -> Int, _ efn: @escaping @autoclosure () -> Int) {
+  // expected-note@-1 2{{parameter 'fn' is implicitly non-escaping}}
+
+    var _ = fn // expected-error {{non-escaping parameter 'fn' may only be called}}
+    let _ = fn // expected-error {{non-escaping parameter 'fn' may only be called}}
+
+    var _ = efn
+    let _ = efn
+
+    _ = id(fn)          // expected-error {{converting non-escaping value to 'T' may allow it to escape}}
+    _ = same(fn, { 3 }) // expected-error {{converting non-escaping value to 'T' may allow it to escape}}
+    _ = same({ 3 }, fn) // expected-error {{converting non-escaping value to 'T' may allow it to escape}}
+
+    withoutActuallyEscaping(fn) { _ in }              // Ok
+    withoutActuallyEscaping(fn) { (_: () -> Int) in } // Ok
+  }
+}

From 6eb94ce1cced515964316ee1a217e8abfa91a5be Mon Sep 17 00:00:00 2001
From: Pavel Yaskevich <pyaskevich@apple.com>
Date: Sun, 11 Nov 2018 00:06:15 -0800
Subject: [PATCH 2/2] [TypeChecker] NFC: Add a test-case for
 rdar://problem/30906031

This problem has been fixed by @autoclosure rework.
---
 test/attr/attr_autoclosure.swift | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/test/attr/attr_autoclosure.swift b/test/attr/attr_autoclosure.swift
index 39d70a732309f..3801fd4455cb3 100644
--- a/test/attr/attr_autoclosure.swift
+++ b/test/attr/attr_autoclosure.swift
@@ -203,3 +203,10 @@ func rdar_20591571() {
     withoutActuallyEscaping(fn) { (_: () -> Int) in } // Ok
   }
 }
+
+// rdar://problem/30906031 - [SR-4188]: withoutActuallyEscaping doesn't accept an @autoclosure argument
+func rdar_30906031(in arr: [Int], fn: @autoclosure () -> Int) -> Bool {
+  return withoutActuallyEscaping(fn) { escapableF in // Ok
+    arr.lazy.filter { $0 >= escapableF() }.isEmpty
+  }
+}