[libcxx-commits] [libcxx] [libc++][hardening] Always enable all checks during constant evaluation (PR #107713)

[Nikolas Klauser via libcxx-commits]

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@@ -0,0 +1,61 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// Make sure that both `_LIBCPP_ASSERT(false, ...)` and `_LIBCPP_ASSUME(false)`
+// mean that a constant expression cannot be formed.
+
+#include <__assert>
+#include "test_macros.h"
+
+// expected-note@*:* 0+ {{expanded from macro}}
+
+static_assert((_LIBCPP_ASSERT(false, "message"), true), "");
+// expected-error at -1 {{static assertion expression is not an integral constant expression}}
+
+static_assert((_LIBCPP_ASSUME(false), true), "");
+// expected-error at -1 {{static assertion expression is not an integral constant expression}}
----------------
philnik777 wrote:

I think it's enough to have a single check that asserts always fire during constant evaluation. There's no way to differentiate between the different ways of getting into constant evaluation AFAIK. We can also use `static_assert(!__builtin_constant_p(_LIBCPP_ASSERT(false, "")), "")` to check that it in fact fires instead.

https://github.com/llvm/llvm-project/pull/107713