Improve unresolved use error message
"use of undeclared type or module `foo`" doesn't mention that it could be a crate.
This error can happen when users forget to add a dependency to `Cargo.toml`, so I think it's important to mention that it could be a missing crate.
I've used a heuristic based on Rust's naming conventions. It complains about an unknown type if the ident starts with an upper-case letter, and crate or module otherwise. It seems to work very well. The expanded error help covers both an unknown type and a missing crate case.
Add `-Z combine_cgu` flag
Introduce a compiler option to let rustc combines all regular CGUs into a single one at the end of compilation.
Part of Issue #64191
VS code graphviz extensions use d3-graphviz, which supports `Courier`
fontname but does not support `monospace`. This caused graphs to render
poorly because the text sizes were wrong.
make `ConstEvaluatable` more strict
relevant zulip discussion: https://rust-lang.zulipchat.com/#narrow/stream/146212-t-compiler.2Fconst-eval/topic/.60ConstEvaluatable.60.20generic.20functions/near/204125452
Let's see how much this impacts. Depending on how this goes this should probably be a future compat warning.
Short explanation: we currently forbid anonymous constants which depend on generic types, e.g. `[0; std::mem::size_of::<T>]` currently errors.
We previously checked this by evaluating the constant and returned an error if that failed. This however allows things like
```rust
const fn foo<T>() -> usize {
if std::mem::size_of::<*mut T>() < 8 { // size of *mut T does not depend on T
std::mem::size_of::<T>()
} else {
8
}
}
fn test<T>() {
let _ = [0; foo::<T>()];
}
```
which is a backwards compatibility hazard. This also has worrying interactions with mir optimizations (https://github.com/rust-lang/rust/pull/74491#issuecomment-661890421) and intrinsics (#74538).
r? `@oli-obk` `@eddyb`
This avoids overlapping a reference covering the data field,
which may be changed due in concurrent conditions. This fully
fixed the UB mainfested with `new_cyclic`.
Since trait implementations cannot be unstable, we should only add them
when the as_str feature gets stabilized. Until then, only `.as_str()` is
available (behind a feature gate).
BTreeMap mutable iterators should not take any reference to visited nodes during iteration
Fixes#73915, overlapping mutable references during BTreeMap iteration
r? `@RalfJung`
The calling convention of pthread_getattr_np() is to initialize the
pthread_attr_t, so _destroy() is only necessary on success (and _init()
isn't necessary beforehand). On the other hand, FreeBSD wants the
attr_t to be initialized before pthread_attr_get_np(), and therefore it
should always be destroyed afterwards.
Make rustdoc output deterministic for UI tests
Closes https://github.com/rust-lang/rust/issues/76442 (hopefully, since it's non-deterministic I don't have a way to test).
r? `@Mark-Simulacrum`
cc `@GuillaumeGomez`
rustdoc: Fix font CSS for crate lists
I had put it in the wrong file in #76126. This should fix it now. Thank
you to `@ollie27` for pointing this out!
---
`@rustbot` modify labels: T-rustdoc C-bug
