Ignore overflow when finding auto-trait impls in Rustdoc #73335
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In rust-lang#72936 (comment), it was determined that some unusual code could cause rustc to overflow when evaluating a predicate of the form `T: AutoTrait`. Even if this is a bug, it will still be possible to cause overflow through writing explicit impls of auto traits, just like any other type of impl. In rustdoc, this overflow can happen simply as a result of defining certain types, since we will automatically generate and evaluate auto-trait predicates when generating documentation. For now, we just ignore overflow during selection if it occurs in rustdoc. We should probably come up with a better way to handle this - e.g. rendering some kind of error in the generated documentation. However, this is a very unusual corner case, and this PR is sufficient to unblock landing a Chalk update in PR rust-lang#72936 This adds additional hacks to `librustc_trait_selection`. The auto-trait-finding code should probably be completely rewritten, but I think this is good enough for the time being.
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…stebank Ignore overflow when finding auto-trait impls in Rustdoc In rust-lang#72936 (comment), it was determined that some unusual code could cause rustc to overflow when evaluating a predicate of the form `T: AutoTrait`. Even if this is a bug, it will still be possible to cause overflow through writing explicit impls of auto traits, just like any other type of impl. In rustdoc, this overflow can happen simply as a result of defining certain types, since we will automatically generate and evaluate auto-trait predicates when generating documentation. For now, we just ignore overflow during selection if it occurs in rustdoc. We should probably come up with a better way to handle this - e.g. rendering some kind of error in the generated documentation. However, this is a very unusual corner case, and this PR is sufficient to unblock landing a Chalk update in PR rust-lang#72936 This adds additional hacks to `librustc_trait_selection`. The auto-trait-finding code should probably be completely rewritten, but I think this is good enough for the time being.
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…stebank Ignore overflow when finding auto-trait impls in Rustdoc In rust-lang#72936 (comment), it was determined that some unusual code could cause rustc to overflow when evaluating a predicate of the form `T: AutoTrait`. Even if this is a bug, it will still be possible to cause overflow through writing explicit impls of auto traits, just like any other type of impl. In rustdoc, this overflow can happen simply as a result of defining certain types, since we will automatically generate and evaluate auto-trait predicates when generating documentation. For now, we just ignore overflow during selection if it occurs in rustdoc. We should probably come up with a better way to handle this - e.g. rendering some kind of error in the generated documentation. However, this is a very unusual corner case, and this PR is sufficient to unblock landing a Chalk update in PR rust-lang#72936 This adds additional hacks to `librustc_trait_selection`. The auto-trait-finding code should probably be completely rewritten, but I think this is good enough for the time being.
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#73452 fixed this issue. I'm going to close this - I may add a less hacky fix for overflow in Rustdoc in a separate PR (maybe a maximum number of iterations?) |
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In #72936 (comment),
it was determined that some unusual code could cause rustc to overflow
when evaluating a predicate of the form
T: AutoTrait. Even if this isa bug, it will still be possible to cause overflow through writing
explicit impls of auto traits, just like any other type of impl.
In rustdoc, this overflow can happen simply as a result of defining
certain types, since we will automatically generate and evaluate
auto-trait predicates when generating documentation.
For now, we just ignore overflow during selection if it occurs in
rustdoc. We should probably come up with a better way to handle this -
e.g. rendering some kind of error in the generated documentation.
However, this is a very unusual corner case, and this PR is sufficient
to unblock landing a Chalk update in PR #72936
This adds additional hacks to
librustc_trait_selection. Theauto-trait-finding code should probably be completely rewritten, but I
think this is good enough for the time being.