Merge pull request #16412 from davidungar/invocation-cutoff-swift-4.2-branch

Author: swift-ci

test/Sema/exhaustive_switch_invocation_threshold.swift

@@ -0,0 +1,51 @@
+// Ensure that -switch-checking-invocation-threshold= frontend option works,
+// stopping the check, producing the correct diagnostic, and not producing the
+// diagnostic for a completed check.
+//
+// RUN: %empty-directory(%t)
+//
+// RUN: not %target-swift-frontend -typecheck %s -switch-checking-invocation-threshold=1 2>%t/unproven.txt
+// RUN: %FileCheck %s --check-prefix UNABLE-TO-CHECK <%t/unproven.txt
+// RUN: not %FileCheck %s --check-prefix MUST-BE-EXHAUSTIVE <%t/unproven.txt
+//
+// RUN: not %target-swift-frontend -typecheck %s  2>%t/disproved.txt
+// RUN: %FileCheck %s --check-prefix MUST-BE-EXHAUSTIVE <%t/disproved.txt
+// RUN: not %FileCheck %s --check-prefix UNABLE-TO-CHECK <%t/disproved.txt
+//
+// UNABLE-TO-CHECK: error: the compiler is unable to check that this switch is exhaustive in reasonable time
+// MUST-BE-EXHAUSTIVE: error: switch must be exhaustive
+
+
+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
+  }
+}