Create `rustc_type_ir`
Decided to start small 😄
This PR creates a `rustc_type_ir` crate as part of the WG-Traits plan to create a shared type library.
~~There already exists a `rustc_ty` crate, so I named the new crate `rustc_ty_library`. However I think it would make sense to rename the current `rustc_ty` to something else (e.g. `rustc_ty_passes`) to free the name for this new crate.~~
r? `@jackh726`
Capture precise paths in THIR and MIR
This PR allows THIR and MIR to use the result of the new capture analysis to actually capture precise paths
To achieve we:
- Writeback min capture results to TypeckResults
- Move handling upvars to PlaceBuilder in mir_build
- Lower precise paths in THIR build by reading min_captures
- Search for ancestors in min_capture when trying to build a MIR place which starts off of an upvar
Closes: https://github.com/rust-lang/project-rfc-2229/issues/10
Partly implements: rust-lang/project-rfc-2229#18
Work that remains (not in this PR):
- [ ] [Known bugs when feature gate is enabled](https://github.com/rust-lang/project-rfc-2229/projects/1?card_filter_query=label%3Abug)
- [ ] Use min_capure_map for
- [ ] Liveness analysis
- [ ] rustc_mir/interpret/validity.rs
- [ ] regionck
- [ ] rust-lang/project-rfc-2229#8
- [ ] remove closure_captures and upvar_capture_map
r? `@ghost`
- Derive TypeFoldable on `hir::place::Place` and associated
structs, to them to be written into typeck results.
Co-authored-by: Jennifer Wills <wills.jenniferg@gmail.com>
Co-authored-by: Logan Mosier <logmosier@gmail.com>
Introduce `TypeVisitor::BreakTy`
Implements MCP rust-lang/compiler-team#383.
r? `@ghost`
cc `@lcnr` `@oli-obk`
~~Blocked on FCP in rust-lang/compiler-team#383.~~
RFC-2229: Implement Precise Capture Analysis
### This PR introduces
- Feature gate for RFC-2229 (incomplete) `capture_disjoint_field`
- Rustc Attribute to print out the capture analysis `rustc_capture_analysis`
- Precise capture analysis
### Description of the analysis
1. If the feature gate is not set then all variables that are not local to the closure will be added to the list of captures. (This is for backcompat)
2. The rest of the analysis is based entirely on how the captured `Place`s are used within the closure. Precise information (i.e. projections) about the `Place` is maintained throughout.
3. To reduce the amount of information we need to keep track of, we do a minimization step. In this step, we determine a list such that no Place within this list represents an ancestor path to another entry in the list. Check rust-lang/project-rfc-2229#9 for more detailed examples.
4. To keep the compiler functional as before we implement a Bridge between the results of this new analysis to existing data structures used for closure captures. Note the new capture analysis results are only part of MaybeTypeckTables that is the information is only available during typeck-ing.
### Known issues
- Statements like `let _ = x` will make the compiler ICE when used within a closure with the feature enabled. More generally speaking the issue is caused by `let` statements that create no bindings and are init'ed using a Place expression.
### Testing
We removed the code that would handle the case where the feature gate is not set, to enable the feature as default and did a bors try and perf run. More information here: #78762
### Thanks
This has been slowly in the works for a while now.
I want to call out `@Azhng` `@ChrisPardy` `@null-sleep` `@jenniferwills` `@logmosier` `@roxelo` for working on this and the previous PRs that led up to this, `@nikomatsakis` for guiding us.
Closesrust-lang/project-rfc-2229#7Closesrust-lang/project-rfc-2229#9Closesrust-lang/project-rfc-2229#6Closesrust-lang/project-rfc-2229#19
r? `@nikomatsakis`
Add type to `ConstKind::Placeholder`
I simply threaded `<'tcx>` through everything that required it. I'm not sure whether this is the correct thing to do, but it seems to work.
r? `@nikomatsakis`
- Handle variants, fields, macros in `Node::ident()`
- Handle the crate root in `opt_item_name`
- Factor out `item_name_from_def_id` to reduce duplication
- Look at HIR before the DefId for `opt_item_name`
This gives accurate spans, which are not available from serialized
metadata.
- Don't panic on the crate root in `opt_item_name`
- Add comments
Iterate over the smaller list
If there are two lists of different sizes,
iterating over the smaller list and then
looking up in the larger list is cheaper
than vice versa, because lookups scale
sublinearly.
If there are two lists of different sizes,
iterating over the smaller list and then
looking up in the larger list is cheaper
than vice versa, because lookups scale
sublinearly.
Use rebind instead of Binder::bind when possible
These are really only the easy places. I just searched for `Binder::bind` and replaced where it straightforward.
r? `@lcnr`
cc. `@nikomatsakis`
Permit uninhabited enums to cast into ints
This essentially reverts part of #6204; it is unclear why that [commit](c0f587de34) was introduced, and I suspect no one remembers.
The changed code was only called from casting checks and appears to not affect any callers of that code (other than permitting this one case).
Fixes#75647.
Record `expansion_that_defined` into crate metadata
Fixes#77523
Now that hygiene serialization is implemented, we also need to record
`expansion_that_defined` so that we properly handle a foreign
`SyntaxContext`.
Reduce boilerplate with the matches! macro
Replaces simple bool `match`es of the form
match $expr {
$pattern => true
_ => false
}
and their inverse with invocations of the matches! macro.
Limited to rustc_middle for now to get my feet wet.
Fixes#77523
Now that hygiene serialization is implemented, we also need to record
`expansion_that_defined` so that we properly handle a foreign
`SyntaxContext`.
lint/ty: move fns to avoid abstraction violation
This PR moves `transparent_newtype_field` and `is_zst` to `LateContext` where they are used, rather than being on the `VariantDef` and `TyS` types, hopefully addressing @eddyb's concern [from this comment](https://github.com/rust-lang/rust/pull/74340#discussion_r456534910).
