Make obligation cause code suggestions verbose
```
error[E0277]: `()` is not a future
--> $DIR/unnecessary-await.rs:28:10
|
LL | e!().await;
| ^^^^^ `()` is not a future
|
= help: the trait `Future` is not implemented for `()`
= note: () must be a future or must implement `IntoFuture` to be awaited
= note: required for `()` to implement `IntoFuture`
help: remove the `.await`
|
LL - e!().await;
LL + e!();
|
```
```
error[E0277]: the trait bound `String: Copy` is not satisfied
--> $DIR/const-fn-in-vec.rs:1:47
|
LL | static _MAYBE_STRINGS: [Option<String>; 5] = [None; 5];
| ^^^^ the trait `Copy` is not implemented for `String`
|
= note: required for `Option<String>` to implement `Copy`
= note: the `Copy` trait is required because this value will be copied for each element of the array
help: create an inline `const` block
|
LL | static _MAYBE_STRINGS: [Option<String>; 5] = [const { None }; 5];
| +++++++ +
```
Part of rust-lang/rust#141973
compiler: set Apple frame pointers by architecture
All Apple targets stop overriding this configuration and instead use the default base of FramePointer::NonLeaf, which means some Apples will have less frame pointers in leaf functions.
r? ``@madsmtm``
cc ``@thomcc``
Limit the size of cgu names when using the `-Zhuman-readable-cgu-name…
…s` option
Prior to this change, cgu names could be generated which would result in filenames longer than the limit imposed by the OS.
This hint allows the compiler to optimize its operation based on this
assumption, in order to compile faster. This is a hint, and does not
guarantee any particular behavior.
This option can substantially speed up compilation if applied to a large
dependency where the majority of the dependency does not get used. This flag
may slow down compilation in other cases.
Currently, this option makes the compiler defer as much code generation as
possible from functions in the crate, until later crates invoke those
functions. Functions that never get invoked will never have code generated for
them. For instance, if a crate provides thousands of functions, but only a few
of them will get called, this flag will result in the compiler only doing code
generation for the called functions. (This uses the same mechanisms as
cross-crate inlining of functions.) This does not affect `extern` functions, or
functions marked as `#[inline(never)]`.
Some performance numbers, based on a crate with many dependencies having
just *one* large dependency set to `-Z hint-mostly-unused` (using
Cargo's `profile-rustflags` option):
A release build went from 4m07s to 2m04s.
A non-release build went from 2m26s to 1m28s.
Verbose suggestion to make param `const`
```
error[E0747]: type provided when a constant was expected
--> $DIR/invalid-const-arguments.rs:10:19
|
LL | impl<N> Foo for B<N> {}
| ^
|
help: consider changing this type parameter to a const parameter
|
LL - impl<N> Foo for B<N> {}
LL + impl<const N: u8> Foo for B<N> {}
|
```
Part of rust-lang/rust#141973.
```
error[E0277]: `()` is not a future
--> $DIR/unnecessary-await.rs:28:10
|
LL | e!().await;
| ^^^^^ `()` is not a future
|
= help: the trait `Future` is not implemented for `()`
= note: () must be a future or must implement `IntoFuture` to be awaited
= note: required for `()` to implement `IntoFuture`
help: remove the `.await`
|
LL - e!().await;
LL + e!();
|
```
```
error[E0277]: the trait bound `String: Copy` is not satisfied
--> $DIR/const-fn-in-vec.rs:1:47
|
LL | static _MAYBE_STRINGS: [Option<String>; 5] = [None; 5];
| ^^^^ the trait `Copy` is not implemented for `String`
|
= note: required for `Option<String>` to implement `Copy`
= note: the `Copy` trait is required because this value will be copied for each element of the array
help: create an inline `const` block
|
LL | static _MAYBE_STRINGS: [Option<String>; 5] = [const { None }; 5];
| +++++++ +
```
Apple targets can now overriding this configuration and instead use the
default based on their architecture, which means aarch64 targets now
have less frame pointers in leaf functions.
Fast path for stalled obligations on self ty
If we see that the `self` type of a goal is an infer var, then don't try to compute the goal at all, since we know that it'll be forced ambiguous.
This is currently only implemented when there are no opaques in the environment. We could extend it to check that the self type is not related to any already defined opaques via subtyping, but I'll leave that as a follow-up.
---
Also stall coerce and subtype predicates if both of their vars are not resolved to concrete types.
---
~~Also, we don't care if the goal is higher-ranked for the sized and copy/clone fast path.~~ pulling this out into another PR.
r? lcnr
doc: Fix inverted meaning in E0783.md
`...` (three dots) was the old way of saying `..=`, which both denote the *inclusive* range, not the *exclusive* one.
canon_abi: make to_erased_extern_abi just a detail in formatting
I think ideally we'd avoid ever printing `CanonAbi` to users, but that needs further changes. Personally I think it's fine for Miri to use the debug printing of `CanonAbi` until we figure that out, but I think others disagree. ;)
r? ``@workingjubilee``
Clean `rustc_attr_parsing/src/lib.rs` documentation
Improves the documentation clarity in `rustc_attr_parsing` by restructuring content with clearer section headers, simplifying explanations of attribute types, making technical descriptions more precise.
r? ``@oli-obk``
Ensure stack in two places that affect s390x
In our Fedora s390x test results, we found two tests that started hitting stack
overflows in the 1.87.0 update. It seems to be related in some part to our use
of PGO as well, probably inlining more into stack frames that were already
recursive. The main points of recursion that I identified were:
- `ui/parser/survive-peano-lesson-queue.rs` in `ThirBuildCx::mirror_exprs`
- `ui/associated-consts/issue-93775.rs` in `Parser::parse_ty`
A couple new `ensure_sufficient_stack` calls will solve these tests.
Replace some `Option<Span>` with `Span` and use DUMMY_SP instead of None
Turns out many locations actually have a span available that we could use, so I used it
Add a new `mismatched-lifetime-syntaxes` lint
The lang-team [discussed this](https://hackmd.io/nf4ZUYd7Rp6rq-1svJZSaQ) and I attempted to [summarize](https://github.com/rust-lang/rust/pull/120808#issuecomment-2701863833) their decision. The summary-of-the-summary is:
- Using two different kinds of syntax for elided lifetimes is confusing. In rare cases, it may even [lead to unsound code](https://github.com/rust-lang/rust/issues/48686)! Some examples:
```rust
// Lint will warn about these
fn(v: ContainsLifetime) -> ContainsLifetime<'_>;
fn(&'static u8) -> &u8;
```
- Matching up references with no lifetime syntax, references with anonymous lifetime syntax, and paths with anonymous lifetime syntax is an exception to the simplest possible rule:
```rust
// Lint will not warn about these
fn(&u8) -> &'_ u8;
fn(&'_ u8) -> &u8;
fn(&u8) -> ContainsLifetime<'_>;
```
- Having a lint for consistent syntax of elided lifetimes will make the [future goal](https://github.com/rust-lang/rust/issues/91639) of warning-by-default for paths participating in elision much simpler.
---
This new lint attempts to accomplish the goal of enforcing consistent syntax. In the process, it supersedes and replaces the existing `elided-named-lifetimes` lint, which means it starts out life as warn-by-default.
