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4596. Gratuitous UB via manifestly constant-evaluated contexts in signal handlers

Section: 17.14.5 [support.signal] Status: New Submitter: Hubert Tong Opened: 2026-06-10 Last modified: 2026-06-14

Priority: Not Prioritized

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Discussion:

17.14.5 [support.signal] paragraph 2 specifies that a signal handler invocation has undefined behaviour if it includes an evaluation that is not signal-safe.

Such an included evaluation (consistent with CWG's understanding; see CWG 3162) may occur within a manifestly constant-evaluated context, in which case, the specified undefined behaviour is gratuitous.

Proposed resolution: