Improve write! and writeln! error when called without destination
Fixesrust-lang/rust#152493
Adds catch-all arms to `write!` and `writeln!` macros so that calling them without a destination (e.g., `write!("S")` instead of `write!(f, "S")`) gives a clear error instead of the cryptic "unexpected end of macro invocation" pointing at macro internals.
r? @estebank
implement `carryless_mul`
tracking issue: https://github.com/rust-lang/rust/issues/152080
ACP: https://github.com/rust-lang/libs-team/issues/738
This defers to LLVM's `llvm.clmul` when available, and otherwise falls back to a method from the `polyval` crate ([link](https://github.com/RustCrypto/universal-hashes/blob/master/polyval/src/field_element/soft/soft64.rs)).
Some things are missing, which I think we can defer:
- the ACP has some discussion about additional methods, but I'm not sure exactly what is wanted or how to implement it efficiently
- the SIMD intrinsic is not yet `const` (I think I ran into a bootstrapping issue). That is fine for now, I think in `stdarch` we can't really use this intrinsic at the moment, we'd only want the scalar version to replace some riscv intrinsics.
- the SIMD intrinsic is not implemented for the gcc and cranelift backends. That should be reasonably straightforward once we have a const eval implementation though.
diagnostics: add note when param-env shadows global impl
This PR adds a diagnostics note when param-env shadows global impl as discussed in https://github.com/rust-lang/rust/issues/149910
It adds a note explaining that the definition is hidden by the generic bound.
r?lcnr
By removing the generic `D` parameter from `DepGraph`, `DepGraphData`,
`CurrentDepGraph`, `SerializedDepGraph`, `SerializedNodeHeader`, and
`EncoderState`.
Rollup of 7 pull requests
Successful merges:
- rust-lang/rust#152622 (Update GCC subtree)
- rust-lang/rust#145024 (Optimize indexing slices and strs with inclusive ranges)
- rust-lang/rust#151365 (UnsafePinned: implement opsem effects of UnsafeUnpin)
- rust-lang/rust#152381 (Do not require `'static` for obtaining reflection information.)
- rust-lang/rust#143575 (Remove named lifetimes in some `PartialOrd` & `PartialEq` `impl`s)
- rust-lang/rust#152404 (tests: adapt align-offset.rs for InstCombine improvements in LLVM 23)
- rust-lang/rust#152582 (rustc_query_impl: Use `ControlFlow` in `visit_waiters` instead of nested options)
the standalone `contains_explicit_ref_binding` function only checked for
`BindingAnnotation::Ref`, missing `BindingAnnotation::RefMut`. this caused
`let ref mut x = expr` to incorrectly take the coercion path instead of
preserving the exact type of the rhs expression. the method version used
for match arms already handles both `Ref` and `RefMut` correctly.
tests: adapt align-offset.rs for InstCombine improvements in LLVM 23
Upstream [has improved InstCombine](8d2078332c) so that it can shrink added constants using known zeroes, which caused a little bit of change in this test. As far as I can tell either output is fine, so we just accept both.
@rustbot label: +llvm-main
Do not require `'static` for obtaining reflection information.
tracking issue rust-lang/rust#142577
This does not affect the stable `TypeId::of`, as that has its own `'static` bound.
But it will allow obtaining `TypeId`s for non-static types via the reflection API. To obtain such a `TypeId` for any type, just use `Type::of::<(T,)>().kind` to extract the first field of a tuple.
This effectively reintroduces rust-lang/rust#41875, which @rust-lang/lang decided against allowing back in 2018 due to lack of sound use cases. We will thus need to have a T-lang meeting specifically about `TypeId` for non-static types before *stabilizing* any part of reflection (in addition to T-lang meetings about reflection in general). I'm adding an explicit point about this to the tracking issue.
cc @scottmcm @joshtriplett @9SonSteroids @SpriteOvO @izagawd @BD103
UnsafePinned: implement opsem effects of UnsafeUnpin
This implements the next step for https://github.com/rust-lang/rust/issues/125735: actually making `UnsafePinned` have special opsem effects by suppressing the `noalias` *even if* the type is wrapped in an `Unpin` wrapper.
For backwards compatibility we also still keep the `Unpin` hack, i.e. a type must be both `Unpin` and `UnsafeUnpin` to get `noalias`.
Optimize indexing slices and strs with inclusive ranges
Instead of separately checking for `end == usize::MAX` and `end + 1 > slice.len()`, we can check for `end >= slice.len()`. Also consolidate all the str indexing related panic functions into a single function which reports the correct error depending on the arguments, as the slice indexing code already does.
The downside of all this is that the panic message is slightly less specific when trying to index with `[..=usize::MAX]`: instead of saying "attempted to index str up to maximum usize" it just says "end byte index {end} out of bounds". But this is a rare enough case that I think it is acceptable
the command 'cargo build --no-default-features --features borsh' failed with:
error[E0599]: no function or associated item named 'other' found for struct 'borsh::io::Error' in the current scope
--> lib/smol_str/src/borsh.rs:33:39
|
33 | .ok_or_else(|| Error::other("u8::vec_from_reader unexpectedly returned None"))?;
| ^^^^^ function or associated item not found in 'borsh::io::Error'
|
Using a struct constructor (DefKind::Ctor(Struct, Const)) as an array
repeat count with `#![feature(min_generic_const_args)]` used to trigger
an ICE in const alias normalization. Add a regression test to ensure
the compiler produces a proper type error instead of panicking.
DepGraphQuery: correctly skip adding edges with not-yet-added nodes
Fixes https://github.com/rust-lang/rust/issues/142152.
The current logic already skips some edges, so I'm not sure how critical it is to have *all* the edges recorded, the logic seems to only be used for debug dumping.
Recording all edges requires supporting holes in the `LinkedGraph` data structure, to add nodes and edges out of order, https://github.com/rust-lang/rust/pull/151821 implements that at cost of complicating the data structure.
Port #[rustc_test_marker] to the attribute parser
Tracking issue: https://github.com/rust-lang/rust/issues/131229
Targets:
Const is for normal tests (const test::TestDescAndFn is inserted before the test fn)
Const/Static/Fn is for custom_test_framework's #[test_case] e.g. tests/ui/custom_test_frameworks/full.rs
r? @JonathanBrouwer
Again I left the use-sites as is since they are early uses.
Don't ICE on layout error in vtable computation
Fixesrust-lang/rust#152030.
Note: I'm including a more general testcase that doesn't use the feature in the original report, but only reproduces with debuginfo disabled. Does it make sense to also include the original testcase?
Make operational semantics of pattern matching independent of crate and module
The question of "when does matching an enum against a pattern of one of its variants read its discriminant" is currently an underspecified part of the language, causing weird behavior around borrowck, drop order, and UB.
Of course, in the common cases, the discriminant must be read to distinguish the variant of the enum, but currently the following exceptions are implemented:
1. If the enum has only one variant, we currently skip the discriminant read.
- This has the advantage that single-variant enums behave the same way as structs in this regard.
- However, it means that if the discriminant exists in the layout, we can't say that this discriminant being invalid is UB. This makes me particularly uneasy in its interactions with niches – consider the following example ([playground](https://play.rust-lang.org/?version=stable&mode=debug&edition=2024&gist=5904a6155cbdd39af4a2e7b1d32a9b1a)), where miri currently doesn't detect any UB (because the semantics don't specify any):
<details><summary>Example 1</summary>
```rust
#![allow(dead_code)]
use core::mem::{size_of, transmute};
#[repr(u8)]
enum Inner {
X(u8),
}
enum Outer {
A(Inner),
B(u8),
}
fn f(x: &Inner) {
match x {
Inner::X(v) => {
println!("{v}");
}
}
}
fn main() {
assert_eq!(size_of::<Inner>(), 2);
assert_eq!(size_of::<Outer>(), 2);
let x = Outer::B(42);
let y = &x;
f(unsafe { transmute(y) });
}
```
</details>
2. For the purpose of the above, enums with marked with `#[non_exhaustive]` are always considered to have multiple variants when observed from foreign crates, but the actual number of variants is considered in the current crate.
- This means that whether code has UB can depend on which crate it is in: https://github.com/rust-lang/rust/issues/147722
- In another case of `#[non_exhaustive]` affecting the runtime semantics, its presence or absence can change what gets captured by a closure, and by extension, the drop order: https://github.com/rust-lang/rust/issues/147722#issuecomment-3674554872
- Also at the above link, there is an example where removing `#[non_exhaustive]` can cause borrowck to suddenly start failing in another crate.
3. Moreover, we currently make a more specific check: we only read the discriminant if there is more than one *inhabited* variant in the enum.
- This means that the semantics can differ between `foo<!>`, and a copy of `foo` where `T` was manually replaced with `!`: rust-lang/rust#146803
- Moreover, due to the privacy rules for inhabitedness, it means that the semantics of code can depend on the *module* in which it is located.
- Additionally, this inhabitedness rule is even uglier due to the fact that closure capture analysis needs to happen before we can determine whether types are uninhabited, which means that whether the discriminant read happens has a different answer specifically for capture analysis.
- For the two above points, see the following example ([playground](https://play.rust-lang.org/?version=nightly&mode=debug&edition=2024&gist=a07d8a3ec0b31953942e96e2130476d9)):
<details><summary>Example 2</summary>
```rust
#![allow(unused)]
mod foo {
enum Never {}
struct PrivatelyUninhabited(Never);
pub enum A {
V(String, String),
Y(PrivatelyUninhabited),
}
fn works(mut x: A) {
let a = match x {
A::V(ref mut a, _) => a,
_ => unreachable!(),
};
let b = match x {
A::V(_, ref mut b) => b,
_ => unreachable!(),
};
a.len(); b.len();
}
fn fails(mut x: A) {
let mut f = || match x {
A::V(ref mut a, _) => (),
_ => unreachable!(),
};
let mut g = || match x {
A::V(_, ref mut b) => (),
_ => unreachable!(),
};
f(); g();
}
}
use foo::A;
fn fails(mut x: A) {
let a = match x {
A::V(ref mut a, _) => a,
_ => unreachable!(),
};
let b = match x {
A::V(_, ref mut b) => b,
_ => unreachable!(),
};
a.len(); b.len();
}
fn fails2(mut x: A) {
let mut f = || match x {
A::V(ref mut a, _) => (),
_ => unreachable!(),
};
let mut g = || match x {
A::V(_, ref mut b) => (),
_ => unreachable!(),
};
f(); g();
}
```
</details>
In light of the above, and following the discussion at rust-lang/rust#138961 and rust-lang/rust#147722, this PR ~~makes it so that, operationally, matching on an enum *always* reads its discriminant.~~ introduces the following changes to this behavior:
- matching on a `#[non_exhaustive]` enum will always introduce a discriminant read, regardless of whether the enum is from an external crate
- uninhabited variants now count just like normal ones, and don't get skipped in the checks
As per the discussion below, the resolution for point (1) above is that it should land as part of a separate PR, so that the subtler decision can be more carefully considered.
Note that this is a breaking change, due to the aforementioned changes in borrow checking behavior, new UB (or at least UB newly detected by miri), as well as drop order around closure captures. However, it seems to me that the combination of this PR with rust-lang/rust#138961 should have smaller real-world impact than rust-lang/rust#138961 by itself.
Fixesrust-lang/rust#142394Fixesrust-lang/rust#146590Fixesrust-lang/rust#146803 (though already marked as duplicate)
Fixes parts of rust-lang/rust#147722Fixesrust-lang/miri#4778
r? @Nadrieril @RalfJung
@rustbot label +A-closures +A-patterns +T-opsem +T-lang
