always resolve to universal regions if possible
`RegionConstraintCollector::opportunistic_resolve_var`, which is used in canonicalization and projection logic, doesn't resolve the region var to an equal universal region. So if we have equated `'static == '1 == '2`, it doesn't resolve `'1` or `'2` to `'static`. Now it does!
Addresses review comment https://github.com/rust-lang/rust/pull/107376#discussion_r1093233687.
r? `@lcnr`
In case a variable is unified with two universal regions from different
universes, use the one with the lower universe as it has a higher chance
of being compatible with the variable.
Do not implement HashStable for HashSet (MCP 533)
This PR removes all occurrences of `HashSet` in query results, replacing it either with `FxIndexSet` or with `UnordSet`, and then removes the `HashStable` implementation of `HashSet`. This is part of implementing [MCP 533](https://github.com/rust-lang/compiler-team/issues/533), that is, removing the `HashStable` implementations of all collection types with unstable iteration order.
The changes are mostly mechanical. The only place where additional sorting is happening is in Miri's override implementation of the `exported_symbols` query.
The crate hash is needed:
- if debug assertions are enabled, or
- if incr. comp. is enabled, or
- if metadata is being generated, or
- if `-C instrumentation-coverage` is enabled.
This commit avoids computing the crate hash when these conditions are
all false, such as when doing a release build of a binary crate.
It uses `Option` to store the hashes when needed, rather than
computing them on demand, because some of them are needed in multiple
places and computing them on demand would make compilation slower.
The commit also removes `Owner::hash_without_bodies`. There is no
benefit to pre-computing that one, it can just be done in the normal
fashion.
fix multiple issues when promoting type-test subject
Multiple interdependent fixes. See linked issues for a short description of each.
When Promoting a type-test `T: 'a` from within the closure back to its parent function, there are a couple pre-existing bugs and limitations. They were exposed by the recent changes to opaque types because the type-test subject (`T`) is no longer a simple ParamTy.
Commit 1:
Fixes#108635Fixes#107426
Commit 2:
Fixes#108639
Commit 3:
Fixes#107516
rustc_middle: Remove trait `DefIdTree`
This trait was a way to generalize over both `TyCtxt` and `Resolver`, but now `Resolver` has access to `TyCtxt`, so this trait is no longer necessary.
Remove `NormalizationError::ConstantKind`
No longer in use by `TryNormalizeAfterErasingRegionsFolder` (as of #102355 / e8150fa60cc445de7a57db634deb0668880be593 it seems). It's making `LayoutError`, etc. kinda large -- that was noticed by `@zoxc.`
Make `ExprKind` the first field in `thir::Expr`
This makes its `Debug` impl print it first which is useful, as it's the most important part when looking at an expr.
Support allocations with non-Box<[u8]> bytes
This is prep work for allowing miri to support passing pointers to C code, which will require `Allocation`s to be correctly aligned. Currently, it just makes `Allocation` generic and plumbs the necessary changes through the right places.
The follow-up to this will be adding a type in the miri interpreter which correctly aligns the bytes, using that for the Miri engine, then allowing Miri to pass pointers into these allocations to C calls.
Based off of #100467, credit to ```@emarteca``` for the code
