Skip walking into param-env component if it has no placeholder/re-var
Although it only provides a minor perf improvement, it seems like it could matter in more pathological cases.
Normalize before computing ConstArgHasType goal in new solver
This is a fix for rust-lang/rust#139905. See the description I left in the test.
I chose to fix this by normalizing the type before matching on its `.kind()` in `compute_const_arg_has_type_goal` (since it feels somewhat consistent with how we normalize types before assembling their candidates, for example); however, there are several other solutions that come to mind for fixing this ICE:
1. (this solution)
2. Giving `ConstKind::Error` a proper type, like `ConstKind::Value`, so that consts don't go from failing to passing `ConstArgHasType` goals after normalization (i.e. `UNEVALUATED` would normalize into a `ConstKind::Error(_, bool)` type rather than losing its type altogether).
3. Just suppressing the errors and accepting the fact that goals can go from fail->pass after normalization.
Thoughts? Happy to discuss this fix further.
r? `@BoxyUwU`
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All occurrences of `~const` outside of libcore have been replaced by `[const]`.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``
Fix some fixmes that were waiting for let chains
Was inspired by looking at rust-lang/rust#143066 and spotting two fixmes that were missed, so... r? `@compiler-errors` 😅
Yay, let chains!
Add note to `find_const_ty_from_env`
Add a note to `find_const_ty_from_env` to explain why it has an `unwrap` which "often" causes ICEs.
Also, uplift it into the new trait solver. This avoids needing to go through the interner to call this method which is otherwise an inherent method in the compiler. I can remove this part if desired.
r? `@boxyuwu`
improve search graph docs, reset `encountered_overflow` between reruns
I think this shouldn't really matter for now. It will be more relevant for my current rework as we otherwise cannot partially reevaluate the root goal in case there has been overflow during the prervious iteration.
r? ````@BoxyUwU````
This commit adds a lint to prevent the use of rustc_type_ir in random
compiler crates, except for type system internals traits, which are
explicitly allowed. Moreover, this fixes diagnostic_items() to include
the CRATE_OWNER_ID, otherwise rustc_diagnostic_item attribute is ignored
on the crate root.
As a performance optimization, skip elaborating the supertraits of
`Sized`, and if a `MetaSized` obligation is being checked, then look for
a `Sized` predicate in the parameter environment. This makes the
`ParamEnv` smaller which should improve compiler performance as it avoids
all the iteration over the larger `ParamEnv`.
Expand the automatic implementation of `MetaSized` and `PointeeSized` so
that it is also implemented on non-`Sized` types, just not `ty::Foreign`
(extern type).
Introduce the `MetaSized` and `PointeeSized` traits as supertraits of
`Sized` and initially implement it on everything that currently
implements `Sized` to isolate any changes that simply adding the
traits introduces.
Tweak fast path trait handling
(1.) Make it more sound by considering polarity (lol)
(2.) Make it more general, by considering higher-ranked size/copy/clone
(2.) Make it less observable, by only doing copy/clone fast path if there are no regions involved
r? lcnr
add additional `TypeFlags` fast paths
Some crates, e.g. `diesel`, have items with a lot of where-clauses (more than 150). In these cases checking the `TypeFlags` of the whole `param_env` can be very beneficial.
This adds `fn fold_clauses` to mirror the existing `fn visit_clauses` and then uses this in folders which fold `ParamEnv`s.
Split out from rust-lang/rust#141451, depends on rust-lang/rust#141442.
r? `@compiler-errors`
