Provisional test for exhaustiveness cutoff.

Author: David Ungar

test/Sema/exhaustive_switch_invocation_threshold.swift

@@ -0,0 +1,44 @@
+// Ensure that -switch-checking-invocation-threshold= frontend option works.
+//
+// RUN: not %target-swift-frontend -typecheck %s -switch-checking-invocation-threshold=1 2>&1 | %FileCheck %s --check-prefix LIMIT
+// RUN: not %target-swift-frontend -typecheck %s  2>&1 | %FileCheck %s --check-prefix NO_LIMIT
+// LIMIT: error: the compiler is unable to check that this switch is exhaustive in reasonable time
+// LIMIT-NOT: error: switch must be exhaustive
+// NO_LIMIT: error: switch must be exhaustive
+// NO_LIMIT-NOT: error: the compiler is unable to check that this switch is exhaustive in reasonable time
+
+import Foundation
+
+enum A {
+  case a1, a2, a3, a4, a5
+}
+enum B {
+  case b1, b2, b3, b4
+}
+
+func f(a: A, b: B) {
+  switch (a, b) {
+    case
+//    (.a1, .b1),
+    (.a2, .b1),
+    (.a3, .b1),
+    (.a4, .b1),
+    (.a5, .b1),
+    (.a1, .b2),
+    (.a2, .b2),
+    (.a3, .b2),
+    (.a4, .b2),
+    (.a5, .b2),
+    (.a1, .b3),
+    (.a2, .b3),
+    (.a3, .b3),
+    (.a4, .b3),
+    (.a5, .b3),
+    (.a1, .b4),
+    (.a2, .b4),
+    (.a3, .b4),
+    (.a4, .b4),
+    (.a5, .b4):
+    break
+  }
+}