Merge pull request swiftlang#21353 from compnerd/_setjmp

Author: swift-ci

stdlib/public/Platform/visualc.apinotes

@@ -0,0 +1,7 @@
+---
+Name: VisualC
+Functions:
+- Name: _setjmp
+  Availability: nonswift
+  AvailabilityMsg: 'Functions that return more than once are unavailable in swift'
+

test/ClangImporter/availability_returns_twice-msvc.swift

@@ -0,0 +1,11 @@
+// RUN: %target-typecheck-verify-swift
+// REQUIRES: OS=windows-msvc
+
+import MSVCRT
+typealias JumpBuffer = _JBTYPE
+
+func test_unavailable_returns_twice_function() {
+  var x: JumpBuffer
+  _ = _setjmp(&x) // expected-error {{'_setjmp' is unavailable in Swift: Functions that return more than once are unavailable in swift}}
+}
+

test/ClangImporter/availability_returns_twice.swift

@@ -1,14 +1,12 @@
 // RUN: %target-typecheck-verify-swift
+// UNSUPPORTED: OS=windows-msvc
 
 #if os(macOS) || os(iOS) || os(watchOS) || os(tvOS)
   import Darwin
   typealias JumpBuffer = Int32
 #elseif os(Android) || os(Cygwin) || os(FreeBSD) || os(Linux)
   import Glibc
   typealias JumpBuffer = jmp_buf
-#elseif os(Windows)
-  import MSVCRT
-  typealias JumpBuffer = jmp_buf
 #endif
 
 func test_unavailable_returns_twice_function() {