Clarify pattern-matching usefulness algorithm
This PR clarifies a bit the usefulness algorithm by emphasizing that each row of the matrix can be seen as a sort of stack from which we pop constructors. It also moves code around to increase separation of concerns.
This is part of my splitting of https://github.com/rust-lang/rust/pull/65160 into smaller PRs.
This system call is present on all supported NetBSD versions and
provides an endless stream of non-blocking random data from the
kernel's ChaCha20-based CSPRNG. It doesn't require a file descriptor
to be opened.
The system call is documented here (under kern.arandom):
https://netbsd.gw.com/cgi-bin/man-cgi?sysctl+7+NetBSD-7.0
And defined here:
https://nxr.netbsd.org/xref/src/sys/sys/sysctl.h#273
The semantics are the same as FreeBSD so reading 256 bytes per call
is fine.
Similar change for getrandom crate: rust-random/getrandom#115
expand: Feature gate out-of-line modules in proc macro input
Extracted from https://github.com/rust-lang/rust/pull/64273.
We are currently gating attributes applied directly to `mod` items because there are unresolved questions about out-of-line modules and their behavior is very likely to change.
However, you can sneak an out-of-line module into an attribute macro input using modules nested into other items like
```rust
#[my_attr]
fn m() {
#[path = "zzz.rs"]
mod n; // what tokens does the `my_attr` macro see?
}
```
This PR prevents that and emits a feature gate error for this case as well.
r? @Centril
It would be great to land this before beta.
Remove LintBuffer from Session
This moves the `LintBuffer` from `Session` into the `Resolver`, where it is used until lowering is done and then consumed by early lint passes. This also happily removes the failure mode of buffering lints too late where it would have previously lead to ICEs; it is statically no longer possible to do so.
I suspect that with a bit more work a similar move could be done for the lint buffer inside `ParseSess`, but this PR doesn't touch it (in part to keep itself small).
The last commit is the "interesting" commit -- the ones before it don't work (though they compile) as they sort of prepare the various crates for the lint buffer to be passed in rather than accessed through Session.
Reduce amount of errors given unclosed delimiter
When in a file with a non-terminated item, catch the error and consume
the block instead of trying to recover it on a more granular way in order to
reduce the amount of unrelated errors that would be fixed after adding
the missing closing brace. Also point out the possible location of the
missing closing brace.
Fix#63690.
For a single-threaded parallel compiler, this reduces instruction counts
across several benchmarks, by up to 2.8%.
The commit also adds documentation about `Sharded`'s use of `FxHasher`.
Move help popup generation code
The first commit is just a small cleanup.
The idea behind this PR is to reduce a bit more the generated HTML files by moving the duplicated code into one place instead.
r? @kinnison
