Since rustc-ap-* v659 we now need to set CFG_RELEASE for
rustc-ap-rustc_attr for `#[cfg(version(...))]` to work.
Co-authored-by: Eric Huss <ehuss@users.noreply.github.com>
This commit introduces a `Limit` type which is used to ensure that all
comparisons against limits within the compiler are consistent (which can
result in ICEs if they aren't).
Signed-off-by: David Wood <david@davidtw.co>
This commit adjusts the condition used in the recursion limit check of
the monomorphization collector, from `>` to `>=`.
In #67552, the test case had infinite indirect recursion, repeating a
handful of functions (from the perspective of the monomorphization
collector): `rec` -> `identity` -> `Iterator::count` -> `Iterator::fold`
-> `Iterator::next` -> `rec`.
During this process, `resolve_associated_item` was invoked for
`Iterator::fold` (during the construction of an `Instance`), and
ICE'd due to substitutions needing inference. However, previous
iterations of this recursion would have called this function for
`Iterator::fold` - and did! - and succeeded in doing so (trivially
checkable from debug logging, `()` is present where `_` is in the substs
of the failing execution).
The expected outcome of this test case would be a recursion limit error
(which is present when the `identity` fn indirection is removed), and
the recursion depth of `rec` is increasing (other functions finish
collecting their neighbours and thus have their recursion depths reset).
When the ICE occurs, the recursion depth of `rec` is 256 (which matches
the recursion limit), which suggests perhaps that a different part of
the compiler is using a `>=` comparison and returning a different result
on this recursion rather than what it returned in every previous
recursion, thus stopping the monomorphization collector from reporting
an error on the next recursion, where `recursion_depth_of_rec > 256`
would have been true.
With grep and some educated guesses, we can determine that
the recursion limit check at line 818 in
`src/librustc_trait_selection/traits/project.rs` is the other check that
is using a different comparison. Modifying either comparison to be `>` or
`>=` respectively will fix the error, but changing the monomorphization
collector produces the nicer error.
Signed-off-by: David Wood <david@davidtw.co>
Pass more `Copy` types by value.
There are a lot of locations where we pass `&T where T: Copy` by reference,
which should both be slightly less performant and less readable IMO.
This PR currently consists of three fairly self contained commits:
- passes `ty::Predicate` by value and stops depending on `AsRef<ty::Predicate>`.
- changes `<&List<_>>::into_iter` to iterate over the elements by value. This would break `List`s
of non copy types. But as the only list constructor requires `T` to be copy anyways, I think
the improved readability is worth this potential future restriction.
- passes `mir::PlaceElem` by value. Mir currently has quite a few copy types which are passed by reference, e.g. `Local`. As I don't have a lot of experience working with MIR, I mostly did this to get some feedback from people who use MIR more frequently
- tries to reuse `ty::Predicate` in case it did not change in some places, which should hopefully
fix the regression caused by #72055
r? @nikomatsakis for the first commit, which continues the work of #72055 and makes adding `PredicateKind::ForAll` slightly more pleasant. Feel free to reassign though
Detect type parameter that might require lifetime constraint.
Do not name `ReVar`s in expected/found output.
Reword text suggesting to check the lifetimes.
This just unwraps clippy's build step instead of skipping tests if clippy didn't
build. This matches e.g. cargo's behavior and seems more correct, as we always
expect clippy to successfully build.
