[PATCH] D130058: [Clang] Diagnose ill-formed constant expression when setting a non fixed enum to a value outside the range of the enumeration values

[Erich Keane via Phabricator via cfe-commits]

erichkeane added inline comments.


================
Comment at: clang/test/SemaCXX/constant-expression-cxx11.cpp:2420
+  constexpr E1 x2 = static_cast<E1>(8); // expected-error {{must be initialized by a constant expression}}
+  // expected-note at -1 {{integer value 8 is outside the valid range of values [-8, 8) for this enumeration type}}
+
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aaron.ballman wrote:
> erichkeane wrote:
> > Are we ok with how subtle the `[N, M)` syntax is here?
> FWIW, I pulled this from diagnostics like: https://github.com/llvm/llvm-project/blob/main/clang/include/clang/Basic/DiagnosticSemaKinds.td#L9904 and https://github.com/llvm/llvm-project/blob/main/clang/include/clang/Basic/DiagnosticSemaKinds.td#L11541
Those aren't particularly high quality diagnostics, the first is for builtin ranges (and builtins have notoriously bad diagnostics), the 2nd is for the matrix type, which is only slightly better.

That said, if you are ok with it, I'm ok, just somewhat afraid it'll be a touch confusing.


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  https://reviews.llvm.org/D130058/new/

https://reviews.llvm.org/D130058