[clang] [Clang][Wswitch-default] Warning for enum even completely covered the cases (PR #75900)

[via cfe-commits]

https://github.com/hstk30-hw created https://github.com/llvm/llvm-project/pull/75900

None

>From 735595ba881de8ab58a7d8f74a31534d90cf5b3a Mon Sep 17 00:00:00 2001
From: hstk-hw <hanwei62 at huawei.com>
Date: Tue, 19 Dec 2023 14:54:16 +0800
Subject: [PATCH] test: add test for Wswitch-default

---
 clang/test/Sema/switch-default.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/clang/test/Sema/switch-default.c b/clang/test/Sema/switch-default.c
index 854b561b37c48e..342a97ee68b1e2 100644
--- a/clang/test/Sema/switch-default.c
+++ b/clang/test/Sema/switch-default.c
@@ -15,3 +15,14 @@ int f2(int a) {
   }
   return a;
 }
+
+// Warn even completely covered Enum cases(GCC compatibility).
+enum E { A, B };
+enum E check_enum(enum E e) {
+  switch (e) {                // expected-warning {{'switch' missing 'default' label}}
+    case A: break;
+    case B: break;
+  }
+  return e;
+}
+