parse: fuse associated and extern items up to defaultness
Language changes:
- The grammar of extern `type` aliases is unified with associated ones, and becomes:
```rust
TypeItem = "type" ident generics {":" bounds}? where_clause {"=" type}? ";" ;
```
Semantic restrictions (`ast_validation`) are added to forbid any parameters in `generics`, any bounds in `bounds`, and any predicates in `where_clause`, as well as the presence of a type expression (`= u8`).
(Work still remains to fuse this with free `type` aliases, but this can be done later.)
- The grammar of constants and static items (free, associated, and extern) now permits the absence of an expression, and becomes:
```rust
GlobalItem = {"const" {ident | "_"} | "static" "mut"? ident} {"=" expr}? ";" ;
```
- A semantic restriction is added to enforce the presence of the expression (the body).
- A semantic restriction is added to reject `const _` in associated contexts.
Together, these changes allow us to fuse the grammar of associated items and extern items up to `default`ness which is the main goal of the PR.
-----------------------
We are now very close to fully fusing the entirely of item parsing and their ASTs. To progress further, we must make a decision: should we parse e.g. `default use foo::bar;` and whatnot? Accepting that is likely easiest from a parsing perspective, as it does not require using look-ahead, but it is perhaps not too onerous to only accept it for `fn`s (and all their various qualifiers), `const`s, `static`s, and `type`s.
r? @petrochenkov
Clean out unused directories for extra disk space
This cleans out some of the unused (but large) directories on our linux builders to hopefully allow them to complete without running out of disk space.
configure: set LLVM flags with a value
Rather than a boolean `--enable-cflags` etc., these options should
reflect that they are for LLVM, and that they need a value. You would
now use `./configure --llvm-cflags="..."`.
recursion_limit parsing handles overflows
This PR adds overflow handling to `#![recursion_limit]` attribute parsing. If parsing the given value results in an `IntErrorKind::Overflow`, then the recursion_limit is set to `usize::max_value()`.
closes#67265
This helps us have enough disk space for our builders to be able to complete
successfully. For now, the choices are ad-hoc and 'definitely not needed'. This
should never fail the build, as everything our build needs should be inside
Docker.
Rather than a boolean `--enable-cflags` etc., these options should
reflect that they are for LLVM, and that they need a value. You would
now use `./configure --llvm-cflags="..."`.
Improve #Safety of various methods in core::ptr
For `read`, `read_unaligned`,`read_volatile`, `replace`, and `drop_in_place`:
- The value they point to must be properly initialized
For `replace`, additionally:
- The pointer must be readable
BTree: lighten the load on Miri
Reduce the amount of work Miri ploughs through in btree code, in particular on `test_clone_from` (which takes up 5 minutes on my machine).
r? @crgl
Split librustc::{traits,infer} to a separate crate rustc_infer
This is still very much work in progress.
Three functions are between dimensions (at the end of `rustc::traits`), waiting for some dependency breaking scheme.
Please tell me if the approach seems sound, and how you would like to split this PR up.
The formatting is deliberately off, to ease rebasing.
cc #65031
rustc_session: allow overriding lint level of individual lints from a group
Fixes#58211 and fixesrust-lang/rust-clippy#4778 and fixesrust-lang/rust-clippy#4091
Instead of hard-coding the lint level preferences (from lowest to highest precedence: `lint::Allow -> lint::Warn -> lint::Deny -> lint::Forbid`), the position of the argument in the command line gets taken into account.
Examples:
1. Passing `-D unused -A unused-variables` denies everything in the lint group `unused` **except** `unused-variables` which is explicitly allowed.
1. Passing `-A unused-variables -D unused` denies everything in the lint group `unused` **including** `unused-variables` since the allow is specified before the deny (and therefore overridden by the deny).
This matches the behavior that is already being used when specifying `allow`/`deny` in the source code.
