Avoid exponential behaviour when relating types
When equating bound types we check subtyping in both directions. Since closures are invariant in their substs, we end up comparing the two types an exponential number of times. If there are no bound variables this isn't needed.
Closes#68061
parser: syntactically allow `self` in all `fn` contexts
Part of https://github.com/rust-lang/rust/pull/68728.
`self` parameters are now *syntactically* allowed as the first parameter irrespective of item context (and in function pointers). Instead, semantic validation (`ast_validation`) is used.
r? @petrochenkov
Rollup of 7 pull requests
Successful merges:
- #68460 (Use BufWriter for emitting MIR)
- #68681 (Suggest path separator for single-colon typos)
- #68688 ([docs] remind bug reporters to update nightly)
- #68704 (Ignore `build` dir formatting)
- #68727 (Remove a comment about pretty printer in formatting tests)
- #68736 (Remove `Alloc` in favor of `AllocRef`)
- #68740 (Do not suggest things named underscore)
Failed merges:
r? @ghost
Remove `Alloc` in favor of `AllocRef`
`AllocRef` was reexported as `Alloc` in #68529 in order to not break toolstate in the week before the next stable release.
r? @Amanieu
Ignore `build` dir formatting
I've noticed that rustfmt tries to parse and check the formatting of code in `build` if `.git` is missing (which includes test artifacts and generated code). This should fix that.
[docs] remind bug reporters to update nightly
Hi and thanks for rust! Today I reported a bug in nightly that was already fixed, so I thought other potential bug reporters might appreciate a reminder to update before reporting. I wasn't sure if this would apply for other channels as well.
Suggest path separator for single-colon typos
This commit adds guidance for when a user means to type a path, but ends
up typing a single colon, such as `<<Impl as T>:Ty>`.
This change seemed pertinent as the current error message is
particularly misleading, emitting `error: unmatched angle bracket`,
despite the angle bracket being matched later on, leaving the user to
track down the typo'd colon.
Use BufWriter for emitting MIR
I noticed that `--emit=mir` takes long time on a large crate. https://github.com/rust-lang/rust/pull/64344 seem to have fixed `-Zdump-mir`, but not `--emit=mir`.
Slimmer syntax
High-level summary of changes:
- The `syntax::node_count` pass is moved into `rustc_ast_passes`. This works towards improving #65031 by making compiling `syntax` go faster.
- The `syntax::{GLOBALS, with_globals, ..}` business is consolidated into `syntax::attr` for cleaner code and future possible improvements.
- The pretty printer loses its dependency on `ParseSess`, opting to use `SourceMap` & friends directly instead.
- Some drive by cleanup of `syntax::attr::HasAttr` happens.
- Builtin attribute logic (`syntax::attr::builtin`) + `syntax::attr::allow_internal_unstable` is moved into a new `rustc_attr` crate. More logic from `syntax::attr` should be moved into that crate over time. This also means that `syntax` loses all mentions of `ParseSess`, which enables the next point.
- The pretty printer `syntax::print` is moved into a new crate `rustc_ast_pretty`.
- `rustc_session::node_id` is moved back as `syntax::node_id`. As a result, `syntax` gets to drop dependencies on `rustc_session` (and implicitly `rustc_target`), `rustc_error_codes`, and `rustc_errors`. Moreover `rustc_hir` gets to drop its dependency on `rustc_session` as well. At this point, these crates are mostly "pure data crates", which is approaching a desirable end state.
- We should consider renaming `syntax` to `rustc_ast` now.
