Added an associated `const THIS_IMPLEMENTATION_HAS_BEEN_TRIPLE_CHECKED`
to the `StableOrd` trait to ensure that implementors carefully consider
whether the trait's contract is upheld, as incorrect implementations can
cause miscompilations.
Make `ObligationEmittingRelation`s emit `Goal` rather than `Obligation`
Helps avoid needing to uplift `Obligation` into the solver. We still can't get rid of `ObligationCause`, but we can keep it as an associated type for `InferCtxtLike` and just give it a `dummy` function.
There's some shuttling between `Goal` and `Obligation` that may be perf-sensitive... Let's see what rust-timer says.
r? lcnr
Edition 2024: Make `!` fall back to `!`
This PR changes never type fallback to be `!` (the never type itself) in the next, 2024, edition.
This makes the never type's behavior more intuitive (in 2024 edition) and is the first step of the path to stabilize it.
r? `@compiler-errors`
Rollup of 6 pull requests
Successful merges:
- #115974 (Split core's PanicInfo and std's PanicInfo)
- #125659 (Remove usage of `isize` in example)
- #125669 (CI: Update riscv64gc-linux job to Ubuntu 22.04, rename to riscv64gc-gnu)
- #125684 (Account for existing bindings when suggesting `pin!()`)
- #126055 (Expand list of trait implementers in E0277 when calling rustc with --verbose)
- #126174 (Migrate `tests/run-make/prefer-dylib` to `rmake.rs`)
r? `@ghost`
`@rustbot` modify labels: rollup
Account for existing bindings when suggesting `pin!()`
When we encounter a situation where we'd suggest `pin!()`, we now account for that expression existing as part of an assignment and provide an appropriate suggestion:
```
error[E0599]: no method named `poll` found for type parameter `F` in the current scope
--> $DIR/pin-needed-to-poll-3.rs:19:28
|
LL | impl<F> Future for FutureWrapper<F>
| - method `poll` not found for this type parameter
...
LL | let res = self.fut.poll(cx);
| ^^^^ method not found in `F`
|
help: consider pinning the expression
|
LL ~ let mut pinned = std::pin::pin!(self.fut);
LL ~ let res = pinned.as_mut().poll(cx);
|
```
Fix#125661.
Split core's PanicInfo and std's PanicInfo
`PanicInfo` is used in two ways:
1. As argument to the `#[panic_handler]` in `no_std` context.
2. As argument to the [panic hook](https://doc.rust-lang.org/stable/std/panic/fn.set_hook.html) in `std` context.
In situation 1, the `PanicInfo` always has a *message* (of type `fmt::Arguments`), but never a *payload* (of type `&dyn Any`).
In situation 2, the `PanicInfo` always has a *payload* (which is often a `String`), but not always a *message*.
Having these as the same type is annoying. It means we can't add `.message()` to the first one without also finding a way to properly support it on the second one. (Which is what https://github.com/rust-lang/rust/issues/66745 is blocked on.)
It also means that, because the implementation is in `core`, the implementation cannot make use of the `String` type (which doesn't exist in `core`): 0692db1a90/library/core/src/panic/panic_info.rs (L171-L172)
This also means that we cannot easily add a useful method like `PanicInfo::payload_as_str() -> Option<&str>` that works for both `&'static str` and `String` payloads.
I don't see any good reasons for these to be the same type, other than historical reasons.
---
This PR is makes 1 and 2 separate types. To try to avoid breaking existing code and reduce churn, the first one is still named `core::panic::PanicInfo`, and `std::panic::PanicInfo` is a new (deprecated) alias to `PanicHookInfo`. The crater run showed this as a viable option, since people write `core::` when defining a `#[panic_handler]` (because they're in `no_std`) and `std::` when writing a panic hook (since then they're definitely using `std`). On top of that, many definitions of a panic hook don't specify a type at all: they are written as a closure with an inferred argument type.
(Based on some thoughts I was having here: https://github.com/rust-lang/rust/pull/115561#issuecomment-1725830032)
---
For the release notes:
> We have renamed `std::panic::PanicInfo` to `std::panic::PanicHookInfo`. The old name will continue to work as an alias, but will result in a deprecation warning starting in Rust 1.82.0.
>
> `core::panic::PanicInfo` will remain unchanged, however, as this is now a *different type*.
>
> The reason is that these types have different roles: `std::panic::PanicHookInfo` is the argument to the [panic hook](https://doc.rust-lang.org/stable/std/panic/fn.set_hook.html) in std context (where panics can have an arbitrary payload), while `core::panic::PanicInfo` is the argument to the [`#[panic_handler]`](https://doc.rust-lang.org/nomicon/panic-handler.html) in no_std context (where panics always carry a formatted *message*). Separating these types allows us to add more useful methods to these types, such as `std::panic::PanicHookInfo::payload_as_str()` and `core::panic::PanicInfo::message()`.
Print `token::Interpolated` with token stream pretty printing.
This is a step towards removing `token::Interpolated` (#124141). It unavoidably changes the output of the `stringify!` macro, generally for the better.
r? `@petrochenkov`
interpret: ensure we check bool/char for validity when they are used in a cast
In general, `Scalar::to_bits` is a bit dangerous as it bypasses all type information. We should usually prefer matching on the type and acting according to that. So I also refactored `unary_op` handling of integers to do that. The remaining `to_bits` uses are operations that just fundamentally don't care about the sign (and only work on integers).
invalid_char_cast.rs is the key new test, the others already passed before this PR.
r? `@oli-obk`
Rollup of 5 pull requests
Successful merges:
- #125913 (Spruce up the diagnostics of some early lints)
- #126234 (Delegation: fix ICE on late diagnostics)
- #126253 (Simplify assert matchers in `run-make-support`)
- #126257 (Rename `needs-matching-clang` to `needs-force-clang-based-tests`)
- #126259 (reachable computation: clarify comments around consts)
r? `@ghost`
`@rustbot` modify labels: rollup
Spruce up the diagnostics of some early lints
Implement the various "*(note to myself) in a follow-up PR we should turn parts of this message into a subdiagnostic (help msg or even struct sugg)*" drive-by comments I left in #124417 during my review.
For context, before #124417, only a few early lints touched/decorated/customized their diagnostic because the former API made it a bit awkward. Likely because of that, things that should've been subdiagnostics were just crammed into the primary message. This PR rectifies this.
Only compute `specializes` query if (min)specialization is enabled in the crate of the specializing impl
Fixes (after backport) https://github.com/rust-lang/rust/issues/125197
### What
https://github.com/rust-lang/rust/pull/122791 makes it so that inductive cycles are no longer hard errors. That means that when we are testing, for example, whether these impls overlap:
```rust
impl PartialEq<Self> for AnyId {
fn eq(&self, _: &Self) -> bool {
todo!()
}
}
impl<T: Identifier> PartialEq<T> for AnyId {
fn eq(&self, _: &T) -> bool {
todo!()
}
}
```
...given...
```rust
pub trait Identifier: Display + 'static {}
impl<T> Identifier for T where T: PartialEq + Display + 'static {}
```
Then we try to see if the second impl holds given `T = AnyId`. That requires `AnyId: Identifier`, which requires that `AnyId: PartialEq`, which is satisfied by these two impl candidates... The `PartialEq<T>` impl is a cycle, and we used to winnow it when we used to treat inductive cycles as errors.
However, now that we don't winnow it, this means that we *now* try calling `candidate_should_be_dropped_in_favor_of`, which tries to check whether one of the impls specializes the other: the `specializes` query. In that query, we currently bail early if the impl is local.
However, in a foreign crate, we try to compute if the two impls specialize each other by doing trait solving. This may itself lead to the same situation where we call `specializes`, which will lead to a query cycle.
### How does this fix the problem
We now record whether specialization is enabled in foreign crates, and extend this early-return behavior to foreign impls too. This means that we can only encounter these cycles if we truly have a specializing impl from a crate with specialization enabled.
-----
r? `@oli-obk` or `@lcnr`
Add `SingleUseConsts` mir-opt pass
The goal here is to make a pass that can be run in debug builds to simplify the common case of constants that are used just once -- that doesn't need SSA handling and avoids any potential downside of multi-use constants. In particular, to simplify the `if T::IS_ZST` pattern that's common in the standard library.
By also handling the case of constants that are *never* actually used this fully replaces the `ConstDebugInfo` pass, since it has all the information needed to do that naturally from the traversal it needs to do anyway.
This is roughly a wash on instructions on its own (a couple regressions, a few improvements https://github.com/rust-lang/rust/pull/125910#issuecomment-2144963361), with a bunch of size improvements. So I'd like to land it as its own PR, then do follow-ups to take more advantage of it (in the inliner, cg_ssa, etc).
r? `@saethlin`
Add explanatory note to async block type mismatch error
The async block type mismatch error might leave the user wondering as to why it occurred. The new note should give them the needed context.
Changes this diagnostic:
```
error[E0308]: mismatched types
--> src/main.rs:5:23
|
2 | let a = async { 1 };
| ----------- the expected `async` block
3 | let b = async { 2 };
| ----------- the found `async` block
4 |
5 | let bad = vec![a, b];
| ^ expected `async` block, found a different `async` block
|
= note: expected `async` block `{async block@src/main.rs:2:13: 2:24}`
found `async` block `{async block@src/main.rs:3:13: 3:24}`
```
to this:
```
error[E0308]: mismatched types
--> src/main.rs:5:23
|
2 | let a = async { 1 };
| ----------- the expected `async` block
3 | let b = async { 2 };
| ----------- the found `async` block
4 |
5 | let bad = vec![a, b];
| ^ expected `async` block, found a different `async` block
|
= note: expected `async` block `{async block@src/main.rs:2:13: 2:24}`
found `async` block `{async block@src/main.rs:3:13: 3:24}`
= note: no two async blocks, even if identical, have the same type
= help: consider pinning your async block and and casting it to a trait object
```
Fixes#125737
Fix ICE due to `unwrap` in `probe_for_name_many`
Fixes#125876
Now `probe_for_name_many` bubbles up the error returned by `probe_op` instead of calling `unwrap` on it.
Enable GVN for `AggregateKind::RawPtr`
Looks like I was worried for nothing; this seems like it's much easier than I was originally thinking it would be.
r? `@cjgillot`
This should be useful for `x[..4]`-like things, should those start inlining enough to expose the lengths.
simd packed types: remove outdated comment, extend codegen test
It seems like https://github.com/rust-lang/rust/pull/125311 made that check in codegen unnecessary?
r? `@workingjubilee` `@calebzulawski`
offset_of: allow (unstably) taking the offset of slice tail fields
Fields of type `[T]` have a statically known offset, so there is no reason to forbid them in `offset_of!`. This PR adds the `offset_of_slice` feature to allow them.
I created a tracking issue: https://github.com/rust-lang/rust/issues/126151.
