Add regression test for `--cap-lints allow` and trait bounds warning
Closes#43134
I have verified that the test fails if stderr begins to contain output by making sure the test fails when I add
eprintln!("some output on stderr");
to the compiler (I added it to `fn build_session()`).
Replace a lazy `RefCell<Option<T>>` with `OnceCell<T>`
This code was using `RefCell<Option<T>>` to manually implement lazy initialization. Now that we have `OnceCell` in the standard library, we can just use that instead.
In particular, this avoids a confusing doubly-nested option, because the value being lazily computed is itself an `Option<Symbol>`.
Skip reporting item name when checking RPITIT GAT's associated type bounds hold
Doesn't really make sense to label an item that has a name that users can't really mention. Fixes#114145. Also fixes#113794.
r? `@spastorino`
privacy: no nominal visibility for assoc fns
Fixes#113860.
When `staged_api` is enabled, effective visibilities are computed earlier and this can trigger an ICE in some cases.
In particular, if a impl of a trait method has a visibility then an error will be reported for that, but when privacy invariants are being checked, the effective visibility will still be greater than the nominal visbility and that will trigger a `span_bug!`.
However, this invariant - that effective visibilites are limited to nominal visibility - doesn't make sense for associated functions.
ci: update ubuntu:20.04 builders to 22.04
This is mostly just maintenance to avoid bitrotting, but 22.04 also updates to cmake 3.22, so they don't need the manual builds from #113714 anymore.
Diagnostic namespace
This PR implements the basic infrastructure for accepting the `#[diagnostic]` attribute tool namespace as specified in https://github.com/rust-lang/rfcs/pull/3368. Note: This RFC is not merged yet, but it seems like it will be accepted soon. I open this PR early on to get feedback on the actual implementation as soon as possible. This hopefully enables getting at least the diagnostic namespace to stable rust "soon", so that crates do not need to bump their MSRV if we stabilize actual attributes in this namespace.
This PR only adds infrastructure accept attributes from this namespace, it does not add any specific attribute. Therefore the compiler will emit a lint warning for each attribute that's actually used. This namespace is added behind a feature flag, so it will be only available on a nightly compiler for now.
cc `@estebank` as they've supported me in planing, specifying and implementing this feature.
When `staged_api` is enabled, effective visibilities are computed earlier
and this can trigger an ICE in some cases.
In particular, if a impl of a trait method has a visibility then an error
will be reported for that, but when privacy invariants are being checked,
the effective visibility will still be greater than the nominal visbility
and that will trigger a `span_bug!`.
However, this invariant - that effective visibilites are limited to
nominal visibility - doesn't make sense for associated functions.
Signed-off-by: David Wood <david@davidtw.co>
new lint: [`readonly_write_lock`]
Closes#8555
A new lint that catches `RwLock::write` calls to acquire a write lock only to read from it and not actually do any writes (mutations).
changelog: new lint: [`readonly_write_lock`]
Optimize `TokenKind::clone`.
`TokenKind` would impl `Copy` if it weren't for
`TokenKind::Interpolated`. This commit makes `clone` reflect that.
r? `@ghost`
I have verified that the test fails if stderr begins to contain output
by making sure the test fails when I add
eprintln!("some output on stderr");
to the compiler (I added it to `fn build_session()`).
style-guide: don't flatten match arms with macro call
This pulls forward the gist of the text that was added to the style guide in https://github.com/rust-lang/style-team/pull/159 to account for needing to tweak/soften rustfmt's behavior based on the style guide prescriptions.
There were a few options I considered, noted below, and although I don't particularly love any of them, I felt this was the lesser of the evils.
r? `@joshtriplett`
Move two tests from `tests/ui/std` to `library/std/tests`
Hi, there,
This pull request comes from this issue (#99417), sorry I made some mistakes creating the pull request, it's my first one.
Less `TokenTree` cloning
`TokenTreeCursor` has this comment on it:
```
// FIXME: Many uses of this can be replaced with by-reference iterator to avoid clones.
```
This PR completes that FIXME. It doesn't have much perf effect, but at least we now know that.
r? `@petrochenkov`
Regression test `println!()` panic message on `ErrorKind::BrokenPipe`
No existing test (that I could find) failed if the `panic!()` of the `println!()` family of functions was removed, or if its message was changed:
104f4300cf/library/std/src/io/stdio.rs (L1007-L1009)
So add such a test.
This is in preparation of adding a hint about the existence of [`unix_sigpipe`](https://github.com/rust-lang/rust/issues/97889) if that is the reason for the panic.
Even if we don't end up adding a hint, this is still a sensible test to have, I think.
`@rustbot` label +A-testsuite +A-io +T-libs +O-unix
