Make slice comparisons const
This needed a fix for `derive_const`, too, as it wasn't usable in libcore anymore as trait impls need const stability attributes. I think we can't use the same system as normal trait impls while `const_trait_impl` is still unstable.
r? ```@fee1-dead```
cc rust-lang/rust#143800
Dont collect assoc ty item bounds from trait where clause for host effect predicates
For background, we uplift `where Self::Assoc: Trait` bounds in a trait's where clauses into *item bounds* on `type Assoc;`. This is because before we *had* syntactical item bounds, users would express their item bounds like so.
Let's opt out of doing this same behavior for `HostEffect` predicates like `where Self::Assoc: [const] Trait`. I left a comment in the code:
```rust
// FIXME(const_trait_impl): We *could* uplift the
// `where Self::Assoc: [const] Trait` bounds from the parent trait
// here too, but we'd need to split `const_conditions` into two
// queries (like we do for `trait_explicit_predicates_and_bounds`)
// since we need to also filter the predicates *out* of the const
// conditions or they lead to cycles in the trait solver when
// utilizing these bounds. For now, let's do nothing.
```
As an aside, this was an ICE that was only triggerable when building libraries and not binaries because we never were calling `tcx.ensure_ok().explicit_implied_const_bounds(def_id);` on associated types like we should have been. I adjusted the calls to `ensure_ok` to make sure this happens, so we catch bugs like this in the future more easily.
As another aside, I fixed the bound uplifting logic for *always const* predicates, since those act like normal clauses and have no notion of conditional constness.
r? ```@oli-obk``` ```@fee1-dead``` or anyone really
Fixesrust-lang/rust#133275
Preserve constness in trait objects up to hir ty lowering
r? ``@compiler-errors``
While we don't support `dyn const Trait`, we can at least also inform the user that `const Trait` is only legal for `#[const_trait] trait Trait {}`
constify `From` and `Into`
tracking issue rust-lang/rust#143773
r? ``````@fee1-dead``````
I did not mark any impls elsewhere as `const`, those can happen on their own timeframe and don't need to be part of this MVP. But if there are some core ones you think should be in there I'll happily add them, just couldn't think of any
New tracking issues for const_ops and const_cmp
Let's do a clean start with new tracking issues to avoid mixing things up with the previous constification.
I assume the fact that the `PartialEq` *trait* and *impls* used different feature names was a mistake (the feature name on the impl is entirely irrelevant anyway).
Part of https://github.com/rust-lang/rust/issues/143800, https://github.com/rust-lang/rust/issues/143802
r? ``@oli-obk``
Constify `Fn*` traits
r? `@compiler-errors` `@fee1-dead`
this should unlock a few things. A few `const_closures` tests have broken even more than before, but that feature is marked as incomplete anyway
cc rust-lang/rust#67792
Most macro tests use `macro` in the name, making it easy to find and run
tests relevant to macros. However, a few use `mbe` instead. Rename those
to say `macro`.
New const traits syntax
This PR only affects the AST and doesn't actually change anything semantically.
All occurrences of `~const` outside of libcore have been replaced by `[const]`. Within libcore we have to wait for rustfmt to be bumped in the bootstrap compiler. This will happen "automatically" (when rustfmt is run) during the bootstrap bump, as rustfmt converts `~const` into `[const]`. After this we can remove the `~const` support from the parser
Caveat discovered during impl: there is no legacy bare trait object recovery for `[const] Trait` as that snippet in type position goes down the slice /array parsing code and will error
r? ``@fee1-dead``
cc ``@nikomatsakis`` ``@traviscross`` ``@compiler-errors``
The version string is difficult to properly normalize out, and removing
it isn't a huge deal (the user can query version info easily through
`rustc --version` or `cargo --version`).
The normalization options were all non-ideal:
- Per-test version string normalization is nasty to maintain, and we
need to maintain `n` copies of it.
- Centralized compiletest normalization (with a directive opt-out) is
also not ideal, because `cfg(version(..))` tests can't have those
accidentally normalized out (and you'd have to remember to opt-out).
Several UI tests have a `normalize-stderr` for "you are using x.y.z"
rustc versions, and that regex is flexible enough for suffixes like
"-nightly" and "-dev", but not for "-beta.N". We can just add '.' to
that trailing pattern to include this.
With `MetaSized` bounds replacing `?Sized` and being added as a
supertrait, the same relaxations applied to the standard library must be
applied to minicore.
More simple 2015 edition test decoupling
This should be the last of these PRs for now. The remaining tests that do not work on other editions than 2015 either need the range support (so blocked on the MCP), need normalization rules (which needs discussions first/same MCP) or revisions.
r? compiler-errors
Merge typeck loop with static/const item eval loop
r? `@ghost`
Let's try a small one first. Doing this in general has some bad cache coherence issues because the query caches are laid out in `Vec<QueryResult>` lists per query where each index refers to a `DefId` in the same order as we're iterating. Iterating two or more lists at the same time does have cache issues, so I want to poke a bit at it to see if we can't merge just a few of them at a time.
