traits/fulfill: allow `stalled_on` to track `ty::Const::Infer(_)` (unused yet).
This PR addresses the representation side of #70180, but only *actually collects* `ty::Infer`s via `Ty::walk` into `stalled_on` (collecting `ty::ConstKind::Infer`s requires #70164).
However, it should be enough to handle #70107's needs (WF obligations are stalled only on the outermost type/const being an inference variable, no `walk`-ing is involved).
This is my second attempt, see #70181 for the previous one, which unacceptably regressed perf.
r? @nikomatsakis cc @nnethercote
rustc: keep upvars tupled in {Closure,Generator}Substs.
Previously, each closure/generator capture's (aka "upvar") type was tracked as one "synthetic" type parameter in the closure/generator substs, and figuring out where the parent `fn`'s generics end and the synthetics start involved slicing at `tcx.generics_of(def_id).parent_count`.
Needing to query `generics_of` limited @davidtwco (who wants to compute some `TypeFlags` differently for parent generics vs upvars, and `TyCtxt` is not available there), which is how I got started on this, but it's also possible that the `generics_of` queries are slowing down `{Closure,Generator}Substs` methods.
To give an example, for a `foo::<T, U>::{closure#0}` with captures `x: X` and `y: Y`, substs are:
* before this PR: `[T, U, /*kind*/, /*signature*/, X, Y]`
* after this PR: `[T, U, /*kind*/, /*signature*/, (X, Y)]`
You can see that, with this PR, no matter how many captures, the last 3 entries in the substs (or 5 for a generator) are always the "synthetic" ones, with the last one being the tuple of capture types.
r? @nikomatsakis cc @Zoxc
Increase verbosity when suggesting subtle code changes
Do not suggest changes that are actually quite small inline, to minimize the likelihood of confusion.
Fix#69243.
couple more clippy fixes (let_and_return, if_same_then_else)
* summarize if-else-code with identical blocks (clippy::if_same_then_else)
* don't create variable bindings just to return the bound value immediately (clippy::let_and_return)
more clippy fixes
* remove unused unit values (clippy::unused_unit)
* make some let-if-bindings more idiomatic (clippy::useless_let_if_seq)
* clarify when we pass () to functions (clippy::unit_arg)
* don't redundantly repeat field names (clippy::redundant_field_names)
* remove redundant returns (clippy::needless_return)
* use let instead of match for matches with single bindings (clippy::match_single_binding)
* don't convert results to options just for matching (clippy::if_let_some_result)
rustc: use LocalDefId instead of DefId in TypeckTables.
The logic in `TypeckTables`' implementation of `HashStable`, which created `DefId`s by combining a `CrateNum` from a `DefId` and a `DefIndex` from a `LocalDefId`, bothered me a bit.
I don't know how much this matters, but it works so might as well submit it.
rustc_infer: remove InferCtxt::closure_sig as the FnSig is always shallowly known.
That is, `ClosureSubsts` is always created (in `rustc_typeck::check::closure`) with a `FnSig`, as the number of inputs is known, even if they might all have inference types.
The only useful thing `InferCtxt::closure_sig` was doing is resolving an inference variable used just to get the `ty::FnPtr` containing that `FnSig` into `ClosureSubsts`.
The ideal way to solve this would be to add a constructor for `ClosureSubsts`, that combines the parent `Substs`, the closure kind, the signature, and capture types together, but for now I've went with resolving the inference types just after unifying them with the real types.
r? @nikomatsakis
Remove some imports to the rustc crate
- When we have `NestedVisitorMap::None`, we use `type Map = dyn intravisit::Map<'v>;` instead of the actual map. This doesn't actually result in dynamic dispatch (in the future we may want to use an associated type default to simplify the code).
- Use `rustc_session::` imports instead of `rustc::{session, lint}`.
r? @Zoxc
Rename rustc guide
This is in preparation for https://github.com/rust-lang/rustc-guide/issues/470
Needs to be merged after we actually rename the guide.
Have used this to rename:
`git grep -l 'rustc_guide' | xargs sed -i 's/rustc_guide/rustc_dev_guide/g'`
`git grep -l 'rustc-guide' | xargs sed -i 's/rustc-guide/rustc-dev-guide/g'`
`git grep -l 'rustc guide' | xargs sed -i 's/rustc guide/rustc dev guide/g'`
Use TypeRelating for instantiating query responses
`eq` can add constraints to `RegionConstraintData`, which isn't allowed during borrow checking outside of a `CustomTypeOp`. Use `TypeRelating` instead to always push constraints to the obligations list.
closes#69490
