accepts-invalid with C++23 constexpr-unknown with struct containing reference #129845
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accepts-invalid
c++23
clang:frontend
Language frontend issues, e.g. anything involving "Sema"
constexpr
Anything related to constant evaluation
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efriedma-quic
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c++23
clang:frontend
|
@llvm/issue-subscribers-clang-frontend Author: Eli Friedman (efriedma-quic)
```
int &ff();
int &x = ff();
struct A { int& x; };
constexpr A g = {x};
const A* gg = &g;
```
Should be rejected, currently accepted. (And related variations miscompile.) |
|
A simpler example (Godbolt link): int &ff();
int &x = ff();
constexpr int &y = x; |
efriedma-quic
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Mar 5, 2025
…consistently. Perform the check for constexpr-unknown values in the same place we perform checks for other values which don't count as constant expressions. While I'm here, also fix a rejects-valid with a reference that doesn't have an initializer. This diagnostic was also covering up some of the bugs here. The existing behavior with -fexperimental-new-constant-interpreter seems to be correct, but the diagnostics are slightly different; it would be helpful if someone could check on that as a followup. Followup to llvm#128409. Fixes llvm#129844. Fixes llvm#129845.
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efriedma-quic
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Mar 10, 2025
…consistently (llvm#129952) Perform the check for constexpr-unknown values in the same place we perform checks for other values which don't count as constant expressions. While I'm here, also fix a rejects-valid with a reference that doesn't have an initializer. This diagnostic was also covering up some of the bugs here. The existing behavior with -fexperimental-new-constant-interpreter seems to be correct, but the diagnostics are slightly different; it would be helpful if someone could check on that as a followup. Followup to llvm#128409. Fixes llvm#129844. Fixes llvm#129845.
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Mar 11, 2025
…consistently (llvm#129952) Perform the check for constexpr-unknown values in the same place we perform checks for other values which don't count as constant expressions. While I'm here, also fix a rejects-valid with a reference that doesn't have an initializer. This diagnostic was also covering up some of the bugs here. The existing behavior with -fexperimental-new-constant-interpreter seems to be correct, but the diagnostics are slightly different; it would be helpful if someone could check on that as a followup. Followup to llvm#128409. Fixes llvm#129844. Fixes llvm#129845.
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Should be rejected, currently accepted. (And related variations miscompile.)
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