[clang] [clang][Sema] Add -Wswitch-default warning option (PR #73077)

[Shafik Yaghmour via cfe-commits]

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@@ -0,0 +1,17 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -Wswitch-default %s
+
+int f1(int a) {
+  switch (a) {                // expected-warning {{'switch' missing 'default' label}}
+    case 1: a++; break;
+    case 2: a += 2; break;
+  }
+  return a;
+}
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shafik wrote:

Might be worth adding a test case that shows that this warns even for completely covered switches e.g. https://godbolt.org/z/zbqr6P5xc

https://github.com/llvm/llvm-project/pull/73077