UB: update the extra clause for provenance UB during const evaluation - #2091
Merged
Merged
Conversation
Loading
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
5 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
The old note didn't make it clear that the transmute is also illegal when it occurs nested inside a field. We already have the framework of "valid values" for this, so let's just use that also for this extra restriction.
Furthermore, there's another way to cause UB with provenance during const evaluation: by having a pointer whose bytes are mixed up.