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261791 commits

Author SHA1 Message Date
Trevor Gross
bd18f88dab
Rollup merge of #128201 - compiler-errors:closure-clone, r=oli-obk
Implement `Copy`/`Clone` for async closures

We can do so in the same cases that regular closures do.

For the purposes of cloning, coroutine-closures are actually precisely the same as regular closures, specifically in the aspect that `Clone` impls care about which is the upvars. The only difference b/w coroutine-closures and regular closures is the type that they *return*, but this type has not been *created* yet, so we don't really have a problem.

IDK why I didn't add this impl initially -- I went back and forth a bit on the internal representation for coroutine-closures before settling on a design which largely models regular closures. Previous (not published) iterations of coroutine-closures used to be represented as a special (read: cursed) kind of coroutine, which would probably suffer from the pitfalls that coroutines have that oli mentioned below in https://github.com/rust-lang/rust/pull/128201#issuecomment-2251230274.

r? oli-obk
2024-07-26 19:03:05 -04:00
Trevor Gross
86721a4c90
Rollup merge of #124941 - Skgland:stabilize-const-int-from-str, r=dtolnay
Stabilize const `{integer}::from_str_radix` i.e. `const_int_from_str`

This PR stabilizes the feature `const_int_from_str`.

- ACP Issue: rust-lang/libs-team#74
- Implementation PR: rust-lang/rust#99322
- Part of Tracking Issue: rust-lang/rust#59133

API Change Diff:

```diff
impl {integer} {
- pub       fn from_str_radix(src: &str, radix: u32) -> Result<Self, ParseIntError>;
+ pub const fn from_str_radix(src: &str, radix: u32) -> Result<Self, ParseIntError>;
}

impl ParseIntError {
- pub       fn kind(&self) -> &IntErrorKind;
+ pub const fn kind(&self) -> &IntErrorKind;
}
```
This makes it easier to parse integers at compile-time, e.g.
the example from the Tracking Issue:

```rust
env!("SOMETHING").parse::<usize>().unwrap()
```

could now be achived  with

```rust
match usize::from_str_radix(env!("SOMETHING"), 10) {
  Ok(val) => val,
  Err(err) => panic!("Invalid value for SOMETHING environment variable."),
}
```

rather than having to depend on a library that implements or manually implement the parsing at compile-time.

---

Checklist based on [Libs Stabilization Guide - When there's const involved](https://std-dev-guide.rust-lang.org/development/stabilization.html#when-theres-const-involved)

I am treating this as a [partial stabilization](https://std-dev-guide.rust-lang.org/development/stabilization.html#partial-stabilizations) as it shares a tracking issue (and is rather small), so directly opening the partial stabilization PR for the subset (feature `const_int_from_str`) being stabilized.

- [x] ping Constant Evaluation WG
- [x] no unsafe involved
- [x] no `#[allow_internal_unstable]`
- [ ] usage of `intrinsic::const_eval_select` rust-lang/rust#124625 in `from_str_radix_assert` to change the error message between compile-time and run-time
- [ ] [rust-labg/libs-api FCP](https://github.com/rust-lang/rust/pull/124941#issuecomment-2207021921)
2024-07-26 19:03:04 -04:00
bors
7c2012d0ec Auto merge of #121676 - Bryanskiy:polarity, r=petrochenkov
Support ?Trait bounds in supertraits and dyn Trait under a feature gate

This patch allows `maybe` polarity bounds under a feature gate. The only language change here is that corresponding hard errors are replaced by feature gates. Example:
```rust
#![feature(allow_maybe_polarity)]
...
trait Trait1 : ?Trait { ... } // ok
fn foo(_: Box<(dyn Trait2 + ?Trait)>) {} // ok
fn bar<T: ?Sized + ?Trait>(_: &T) {} // ok
```
Maybe bounds still don't do anything (except for `Sized` trait), however this patch will allow us to [experiment with default auto traits](https://github.com/rust-lang/rust/pull/120706#issuecomment-1934006762).

This is a part of the [MCP: Low level components for async drop](https://github.com/rust-lang/compiler-team/issues/727)
2024-07-26 20:14:16 +00:00
Michael Goulet
5a9959fd9d Suppress useless clone suggestion 2024-07-26 12:53:55 -04:00
Michael Goulet
d5656059a1 Make coroutine-closures possible to be cloned 2024-07-26 12:53:53 -04:00
bors
47243b335e Auto merge of #128065 - Oneirical:great-testilence, r=jieyouxu
Migrate `c-unwind-abi-catch-lib-panic`, `foreign-rust-exceptions` and `export-executable-symbols` `run-make` tests to rmake

Part of #121876 and the associated [Google Summer of Code project](https://blog.rust-lang.org/2024/05/01/gsoc-2024-selected-projects.html).

Please try:

try-job: aarch64-apple
try-job: i686-mingw
2024-07-26 16:21:41 +00:00
Oneirical
3cc1056ff7 rewrite export-executable-symbols to rmake 2024-07-26 10:17:39 -04:00
Oneirical
2a3e4c547b rewrite foreign-rust-exceptions to rmake 2024-07-26 10:17:04 -04:00
Oneirical
e2dbba8d4d rewrite c-unwind-abi-catch-lib-panic to rmake 2024-07-26 10:17:03 -04:00
Bryanskiy
fd9d0bfbac Forbid ?Trait bounds repetitions 2024-07-26 16:35:05 +03:00
bors
2d5a628a1d Auto merge of #128165 - saethlin:optimize-clone-shims, r=compiler-errors
Let InstCombine remove Clone shims inside Clone shims

The Clone shims that we generate tend to recurse into other Clone shims, which gets very silly very quickly. Here's our current state: https://godbolt.org/z/E69YeY8eq

So I've added InstSimplify to the shims optimization passes, and improved `is_trivially_pure_clone_copy` so that it can delete those calls inside the shim. This makes the shim way smaller because most of its size is the required ceremony for unwinding.

This change also completely breaks the UI test added for https://github.com/rust-lang/rust/issues/104870. With this PR, that program ICEs in MIR type checking because `is_trivially_pure_clone_copy` and the trait solver disagree on whether `*mut u8` is `Copy`. And adding the requisite `Copy` impl to make them agree makes the test not generate any diagnostics. Considering that I spent most of my time on this PR fixing `#![no_core]` tests, I would prefer to just delete this one. The maintenance burden of `#![no_core]` is uniquely high because when they break they tend to break in very confusing ways.

try-job: x86_64-mingw
2024-07-26 13:13:04 +00:00
bors
355efacf0d Auto merge of #128034 - Nadrieril:explain-unreachable, r=compiler-errors
exhaustiveness: Explain why a given pattern is considered unreachable

This PR tells the user why a given pattern is considered unreachable. I reused the intersection information we were already computing; even though it's incomplete I convinced myself that it is sufficient to always get a set of patterns that cover the unreachable one.

I'm not a fan of the diagnostic messages I came up with, I'm open to suggestions.

Fixes https://github.com/rust-lang/rust/issues/127870. This is also the other one of the two diagnostic improvements I wanted to do before https://github.com/rust-lang/rust/pull/122792.

Note: the first commit is an unrelated drive-by tweak.

r? `@compiler-errors`
2024-07-26 10:51:04 +00:00
bors
83d67685ac Auto merge of #128222 - tgross35:rollup-fk7qdo3, r=tgross35
Rollup of 7 pull requests

Successful merges:

 - #126575 (Make it crystal clear what lint `type_alias_bounds` actually signifies)
 - #127017 (Extend rules of dead code analysis for impls for adts to impls for types refer to adts)
 - #127523 (Migrate `dump-ice-to-disk` and `panic-abort-eh_frame` `run-make` tests to rmake)
 - #127557 (Add a label to point to the lacking macro name definition)
 - #127989 (Migrate `interdependent-c-libraries`, `compiler-rt-works-on-mingw` and `incr-foreign-head-span` `run-make` tests to rmake)
 - #128099 (migrate tests/run-make/extern-flag-disambiguates to rmake)
 - #128170 (Make Clone::clone a lang item)

r? `@ghost`
`@rustbot` modify labels: rollup
2024-07-26 08:26:17 +00:00
Trevor Gross
97eade42f7
Rollup merge of #128170 - saethlin:clone-fn, r=compiler-errors
Make Clone::clone a lang item

I want to absorb all the logic for picking whether an Instance is LocalCopy or GloballyShared into one place. As part of this, I wanted to identify Clone shims inside `cross_crate_inlinable` and found that rather tricky. `@compiler-errors` suggested that I add a lang item for `Clone::clone` because that would produce other cleanups in the compiler.

That sounds good to me, but I have looked and I've only been able to find one.

r? compiler-errors
2024-07-26 02:20:31 -04:00
Trevor Gross
0f1ea63393
Rollup merge of #128099 - lolbinarycat:extern-flag-disambiguates-rmake, r=Kobzol
migrate tests/run-make/extern-flag-disambiguates to rmake
2024-07-26 02:20:31 -04:00
Trevor Gross
4290de8ab4
Rollup merge of #127989 - Oneirical:testricted-area, r=jieyouxu
Migrate `interdependent-c-libraries`, `compiler-rt-works-on-mingw` and `incr-foreign-head-span` `run-make` tests to rmake

Part of #121876 and the associated [Google Summer of Code project](https://blog.rust-lang.org/2024/05/01/gsoc-2024-selected-projects.html).

try-job: aarch64-apple
try-job: armhf-gnu
try-job: test-various
try-job: x86_64-mingw
try-job: x86_64-msvc
try-job: x86_64-gnu-llvm-18
2024-07-26 02:20:30 -04:00
Trevor Gross
c5788d618e
Rollup merge of #127557 - linyihai:issue-126694, r=compiler-errors
Add a label to point to the lacking macro name definition

Fixes https://github.com/rust-lang/rust/issues/126694, but adopts the suggestion from https://github.com/rust-lang/rust/issues/118295

```
 --> src/main.rs:1:14
  |
1 | macro_rules! {
  |            ^ put a macro name here
```
2024-07-26 02:20:30 -04:00
Trevor Gross
96fb3544b0
Rollup merge of #127523 - Oneirical:treasure-test, r=jieyouxu
Migrate `dump-ice-to-disk` and `panic-abort-eh_frame` `run-make` tests to rmake

Part of #121876 and the associated [Google Summer of Code project](https://blog.rust-lang.org/2024/05/01/gsoc-2024-selected-projects.html).

Please try:

try-job: x86_64-msvc
try-job: i686-mingw
2024-07-26 02:20:29 -04:00
Trevor Gross
a70dc297a8
Rollup merge of #127017 - mu001999-contrib:dead/enhance, r=pnkfelix
Extend rules of dead code analysis for impls for adts to impls for types refer to adts

The rules of dead code analysis for impl blocks can be extended to self types which refer to adts.

So that we can lint the following unused struct and trait:
```rust
struct Foo; //~ ERROR struct `Foo` is never constructed

trait Trait { //~ ERROR trait `Trait` is never used
    fn foo(&self) {}
}

impl Trait for &Foo {}
```

r? `@pnkfelix`
2024-07-26 02:20:29 -04:00
Trevor Gross
ceae37188b
Rollup merge of #126575 - fmease:update-lint-type_alias_bounds, r=compiler-errors
Make it crystal clear what lint `type_alias_bounds` actually signifies

This is part of my work on https://github.com/rust-lang/rust/labels/F-lazy_type_alias ([tracking issue](#112792)).

---

To recap, the lint `type_alias_bounds` detects bounds on generic parameters and where clauses on (eager) type aliases. These bounds should've never been allowed because they are currently neither enforced[^1] at usage sites of type aliases nor thoroughly checked for correctness at definition sites due to the way type aliases are represented in the compiler. Allowing them was an oversight.

Explicitly label this as a known limitation of the type checker/system and establish the experimental feature `lazy_type_alias` as its eventual proper solution.

Where this becomes a bit tricky (for me as a rustc dev) are the "secondary effects" of these bounds whose existence I sadly can't deny. As a matter of fact, type alias bounds do play some small roles during type checking. However, after a lot of thinking over the last two weeks I've come to the conclusion (not without second-guessing myself though) that these use cases should not trump the fact that these bounds are currently *inherently broken*. Therefore the lint `type_alias_bounds` should and will continue to flag bounds that may have subordinate uses.

The two *known* secondary effects are:

1. They may enable the use of "shorthand" associated type paths `T::Assoc` (as opposed to fully qualified paths `<T as Trait>::Assoc`) where `T` is a type param bounded by some trait `Trait` which defines that assoc ty.
2. They may affect the default lifetime of trait object types passed as a type argument to the type alias. That concept is called (trait) object lifetime default.

The second one is negligible, no question asked. The first one however is actually "kinda nice" (for writability) and comes up in practice from time to time.

So why don't I just special-case trait bounds that "define" shorthand assoc type paths as originally planned in #125709?

1. Starting to permit even a tiny subset of bounds would already be enough to send a signal to users that bounds in type aliases have been legitimized and that they can expect to see type alias bounds in the wild from now on (proliferation). This would be actively misleading and dangerous because those bounds don't behave at all like one would expect, they are *not real*[^2]!
   1. Let's take `type A<T: Trait> = T::Proj;` for example. Everywhere else in the language `T: Trait` means `T: Trait + Sized`. For type aliases, that's not the case though: `T: Trait` and `T: Trait + ?Sized` for that matter do neither mean `T: Trait + Sized` nor `T: Trait + ?Sized` (for both!). Instead, whether `T` requires `Sized` or not entirely depends on the definition of `Trait`[^2]. Namely, whether or not it is bounded by `Sized`.
   2. Given `type A<T: Trait<AssocA = ()>> = T::AssocB;`, while `X: Trait` gets checked given `A<X>` (by virtue of projection wfchecking post alias expansion[^2]), the associated type constraint `AssocA = ()` gets dropped entirely! While we could choose to warn on such cases, it would inevitably lead to a huge pile of special cases.
   3. While it's common knowledge that the body / aliased type / RHS of an (eager) type alias does not get checked for well-formedness, I'm not sure if people would realize that that extends to bounds as well. Namely, `type A<T: Trait<[u8]>> = T::Proj;` compiles even if `Trait`'s generic parameter requires `Sized`. Of course, at usage sites `[u8]: Sized` would still end up getting checked[^2], so it's not a huge problem if you have full control over `A`. However, imagine that `A` was actually part of a public API and was never used inside the defining crate (not unreasonable). In such a scenario, downstream users would be presented with an impossible to use type alias! Remember, bounds may grow arbitrarily complex and nuanced in practice.
   4. Even if we allowed trait bounds that "define" shorthand assoc type paths, we would still need to continue to warn in cases where the assoc ty comes from a supertrait despite the fact that the shorthand syntax can be used: `type A<T: Sub> = T::Assoc;` does compile given `trait Sub: Super {}` and `trait Super { type Assoc; }`. However, `A<X>` does not enforce `X: Sub`, only `X: Super`[^2]. All that to say, type alias bounds are simply not real and we shouldn't pretend they are!
   5. Summarizing the points above, we would be legitimizing bounds that are completely broken!
2. It's infeasible to implement: Due to the lack of `TypeckResults` in `ItemCtxt` (and a way to propagate it to other parts of the compiler), the resolution of type-dependent paths in non-`Body` items (most notably type aliases) is not recoverable from the HIR alone which would be necessary because the information of whether an associated type path (projection) is a shorthand is only present pre&in-HIR and doesn't survive HIR ty lowering. Of course, I could rerun parts of HIR ty lowering inside the lint `type_alias_bounds` (namely, `probe_single_ty_param_bound_for_assoc_ty` which would need to be exposed or alternatively a stripped-down version of it). This likely has a performance impact and introduces complexity. In short, the "benefits" are not worth the costs.

---

* 3rd commit: Update a diagnostic to avoid suggesting type alias bounds
* 4th commit: Flag type alias bounds even if the RHS contains inherent associated types.
  * I started to allow them at some point in the past which was not correct (see commit for details)
* 5th commit: Allow type alias bounds if the RHS contains const projections and GCEs are enabled
  * (and add a `FIXME(generic_const_exprs)` to be revisited before (M)GCE's stabilization)
  * As a matter of fact type alias bounds are enforced in this case because the contained AnonConsts do get checked for well-formedness and crucially they inherit the generics and predicates of their parent item (here: the type alias)
* Remaining commits: Improve the lint `type_alias_bounds` itself

---

Fixes #125789 (sugg diag fix).
Fixes #125709 (wontfix, acknowledgement, sugg diag applic fix).
Fixes #104918 (sugg diag applic fix).
Fixes #100270 (wontfix, acknowledgement, sugg diag applic fix).
Fixes #94398 (true fix).

r? `@compiler-errors` `@oli-obk`

[^1]: From the perspective of the trait solver.
[^2]: Given `type A<T: Trait> = T::Proj;`, the reason why the trait bound "`T: Trait`" gets *seemingly* enforced at usage sites of the type alias `A` is simply because `A<X>` gets expanded to "`<X as Trait>::Proj`" very early on and it's the *expansion* that gets checked for well-formedness, not the type alias reference.
2024-07-26 02:20:28 -04:00
bors
6ef11b81c2 Auto merge of #120593 - maurer:android-bump, r=Mark-Simulacrum,workingjubilee
Update Android in CI

We are currently using a 10+ year old Android image, and it has caused trouble when working on #120326.

Our current NDK (25) only supports API 19+, so we were already out of spec. This PR:

1. Bumps the API used by the emulator in CI to 21, as per [NDK-26's release notes](https://github.com/android/ndk/wiki/Changelog-r26) deprecating 19 and 20 as targets.
2. Bumps the NDK to 26b

try-job: arm-android
2024-07-26 05:58:16 +00:00
bors
48bbe123c2 Auto merge of #128193 - flip1995:clippy-subtree-update, r=matthiaskrgr
Clippy subtree update

r? `@Manishearth`

Updates Cargo.lock due to the Clippy version update and the ui_test bump to v0.24
2024-07-26 03:36:34 +00:00
Lin Yihai
2fca4ea317 Add a label to point to the lacking macro name definition 2024-07-26 10:51:55 +08:00
bors
72d73cec61 Auto merge of #128213 - matthiaskrgr:rollup-v40q1j3, r=matthiaskrgr
Rollup of 7 pull requests

Successful merges:

 - #126090 (Fix supertrait associated type unsoundness)
 - #127220 (Graciously handle `Drop` impls introducing more generic parameters than the ADT)
 - #127950 (Use `#[rustfmt::skip]` on some `use` groups to prevent reordering.)
 - #128085 (Various notes on match lowering)
 - #128150 (Stop using `unsized_const_parameters` in core/std)
 - #128194 (LLVM: LLVM-20.0 removes MMX types)
 - #128211 (fix: compilation issue w/ refactored type)

r? `@ghost`
`@rustbot` modify labels: rollup
2024-07-26 01:13:26 +00:00
Matthew Maurer
8bf9aeaa80 Update Android testing to API 21, matching NDK 26
We were running testing on API 18, which was already out of support for
NDK 25, and some of the ancient behavior in that image was causing
trouble when developing `rustc` features (#120326).

Update to the current LTS NDK 26, and to its minimum supported API 21.

Fixes: #120567
2024-07-26 00:52:42 +00:00
Matthias Krüger
d87fa5e788
Rollup merge of #128211 - juliusl:pr/align-change-time, r=tgross35
fix: compilation issue w/ refactored type

Fixes a compilation issue related to #121478
2024-07-26 00:57:24 +02:00
Matthias Krüger
d03c56f45d
Rollup merge of #128194 - maurer:fix-mmx, r=cuviper
LLVM: LLVM-20.0 removes MMX types

See llvm/llvm-project#98505

`@rustbot` label: +llvm-main
2024-07-26 00:57:23 +02:00
Matthias Krüger
ba990ae8af
Rollup merge of #128150 - BoxyUwU:std_only_sized_const_params, r=workingjubilee
Stop using `unsized_const_parameters` in core/std

`feature(unsized_const_parameters)` is an incomplete feature and should not be used by core/std as it makes it can make it significantly harder to evolve the feature. It also just generally opens the possibility of introducing bugs on stable through std's backdoor.

The only usage of this feature in std is the `simd_shuffle_intrinsic` added in #119213. It doesn't seem to be used anywhere as far as I can tell so it is removed in this PR. All tests and codegen logic etc have been kept however.

r? `@workingjubilee`
2024-07-26 00:57:22 +02:00
Matthias Krüger
f345c5e845
Rollup merge of #128085 - Zalathar:notes, r=Nadrieril
Various notes on match lowering

This is an assortment of comments for things that I found unclear or confusing when I was learning how match lowering works.

This PR only adds/modifies comments, so there are no functional changes.

I have tried to avoid touching code that would conflict with #127159.

r? `@Nadrieril`
2024-07-26 00:57:22 +02:00
Matthias Krüger
ab2dd3aeb9
Rollup merge of #127950 - nnethercote:rustfmt-skip-on-use-decls, r=cuviper
Use `#[rustfmt::skip]` on some `use` groups to prevent reordering.

`use` declarations will be reformatted in #125443. Very rarely, there is a desire to force a group of `use` declarations together in a way that auto-formatting will break up. E.g. when you want a single comment to apply to a group. #126776 dealt with all of these in the codebase, ensuring that no comments intended for multiple `use` declarations would end up in the wrong place. But some people were unhappy with it.

This commit uses `#[rustfmt::skip]` to create these custom `use` groups in an idiomatic way for a few of the cases changed in #126776. This works because rustfmt treats any `use` item annotated with `#[rustfmt::skip]` as a barrier and won't reorder other `use` items around it.

r? `@cuviper`
2024-07-26 00:57:21 +02:00
Matthias Krüger
29314e4fca
Rollup merge of #127220 - BoxyUwU:dropck_handle_extra_impl_params, r=compiler-errors
Graciously handle `Drop` impls introducing more generic parameters than the ADT

Follow up to #110577
Fixes #126378
Fixes #126889

## Motivation

A current issue with the way we check drop impls do not specialize any of their generic parameters is that when the `Drop` impl introduces *more* generic parameters than are present on the ADT, we fail to prove any bounds involving those parameters. This can be demonstrated with the following [code on stable](https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&gist=139b65e4294634d7286a3282bc61e628) which fails due to the fact that `<T as Trait>::Assoc == U` is not present in `Foo`s `ParamEnv` even though arguably there is no reason it cannot compiler:
```rust
struct Foo<T: Trait>(T);

trait Trait {
    type Assoc;
}

impl<T: Trait<Assoc = U>, U: ?Sized> Drop for Foo<T> {
    //~^ ERROR: `Drop` impl requires `<T as Trait>::Assoc == U` but the struct ...
    fn drop(&mut self) {}
}

fn main() {}
```

I think the motivation for supporting this code is somewhat lacking, it might be useful in practice for deeply nested associated types where you might want to be able to write:
`where T: Trait<Assoc: Other<AnotherAssoc: MoreTrait<YetAnotherAssoc: InnerTrait<Final = U>>>>`
in order to be able to just use `U` in the function body instead of writing out the whole nested associated type. Regardless I don't think there is really any reason to *not* support this code and it is relatively easy to support it.

What I find slightly more compelling is the fact that when defining a const parameter `const N: u8` we desugar that to having a where clause requiring the constant `N` is typed as `u8` (`ClauseKind::ConstArgHasType`). As we *always* desugar const parameters to have these bounds, if we attempt to prove that some const parameter `N` is of type `u8` and there is no bound on `N` in the enviroment that generally indicates usage of an incorrect `ParamEnv` (this has caught a bug already).

Given that, if we write the following code:
```rust
#![feature(associated_const_equality)]
struct Foo<T: Trait>(T);

trait Trait {
    const ASSOC: usize;
}

impl<T: Trait<ASSOC = N>, const N: usize> Drop for Foo<T> {
    fn drop(&mut self) {}
}

fn main() {}
```

The `Drop` impl would have this desugared where clause about `N` being of type `usize`, and if we were to try to prove that where clause in `Foo`'s `ParamEnv` we would ICE as there would not be any `ConstArgHasType` in the environment (which generally indicates improper `ParamEnv` usage. As this is otherwise well formed code (the `T: Trait<ASSOC = N>` causes `N` to be constrained) we have to handle this *somehow* and I believe the only principled way to support this is the changes I have made to `dropck.rs` that would cause these code examples to compiler (Perhaps we could just throw out all `ConstArgHasType` where clauses from the predicates we prove but that makes me nervous even if it might actually be okay).

## The changes

Currently the way `dropck.rs` works is that take the `ParamEnv` of the ADT and instantiate it with the generic arguments used on the self ty of the `impl`. We then instantiate the predicates of the drop impl with the identity params to the impl,  e.g. in the original example `<T as Trait>::Assoc == U` stays as `<T as Trait>::Assoc == U`. We then attempt to prove all the where clauses in the instantiated env of the self type ADT.

This PR changes us to first instantiate the impl with infer vars, then we equate the self type (with infer vars as its generic arguments) with the self type as written by the user. This causes all generic parameters on the impl that are constrained via associated type/const equality bounds to be left as inference variables while all other parameters are still `Ty`/`Const`/`Region`

Finally when instantiating the predicates on the impl, instead of using the identity arguments, we use the list of inference variables of which some have been inferred to the impl parameters. In practice this means that we wind up proving `<T as Trait>::Assoc == ?x` which can succeed just fine. In the const generics example we would wind up trying to prove `ConstArgHasType(?x: usize)` instead of `ConstArgHasType(N: usize)` which avoids the ICE as it is expected to encounter goals of the form `?x: usize`.

At a higher level the way I justify/think about this is that as we are proving goals in the environment of the ADT (`Foo` in the above examples), we do not expect to encounter generic parameters from a different environment so we must "deal with them" somehow. In this PR we handle them by replacing them with inference variables as they should either *actually* be unconstrained (and we will error later) or they are constrained to be equal to some associated type/const.

To go along with this it would be nice if we were not instantiating the adt's env with the generic arguments to the ADT in the `Drop` impl as it would make it clearer we are proving bounds in the adt's env instead of the `Drop` impl's. Instead we would map the predicates on the drop impl to be valid in the environment of the adt. In practice this causes diagnostic regressions as all of the generic parameters in errors refer to the ones defined on the adt; attempting to map these back to the ones on the impl, while possible, is involved as writing a `TypeFolder` over `FulfillmentError` is non trivial.

## Edge cases

There are some subtle interactions here:

One is that we should not allow `<T as Trait>::Assoc == U` to be present on the `Drop` if `U` is constrained by the self type of the impl and the bound is not present in the ADT's environment. demonstrated with the [following code](https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&gist=af839e2c3e43e03a624825c58af84dff):
```rust
trait Trait {
    type Assoc;
}

struct Foo<T: Trait, U: ?Sized>(T, U);

impl<T: Trait<Assoc = U>, U: ?Sized> Drop for Foo<T, U> {
    //~^ ERROR: `Drop` impl requires `<T as Trait>::Assoc == U`
    fn drop(&mut self) {}
}

fn main() {}
```
This is tested at `tests/ui/dropck/constrained_by_assoc_type_equality_and_self_ty.rs`.

Another weirdness is that we permit the following code to compile now:
```rust
struct Foo<T>(T);

impl<'a, T: 'a> Drop for Foo<T> {
    fn drop(&mut self) {}
}
```
This is caused by the fact that we permit unconstrained lifetime parameters in trait implementations as long as they are not used in associated types (so we do not wind up erroring on this code like we perhaps ought to), combined with the fact that as we are now proving `T: '?x` instead of `T: 'a` which allows proving the bound via `'?x= 'empty` wheras previously it would have failed.

This is tested as part of `tests/ui/dropck/reject-specialized-drops-8142.rs`.

---

r? `@compiler-errors`
2024-07-26 00:57:21 +02:00
Matthias Krüger
a88354831b
Rollup merge of #126090 - compiler-errors:supertrait-assoc-ty-unsoundness, r=lcnr
Fix supertrait associated type unsoundness

### What?

Object safety allows us to name `Self::Assoc` associated types in certain positions if they come from our trait or one of our supertraits. When this check was implemented, I think it failed to consider that supertraits can have different args, and it was only checking def-id equality.

This is problematic, since we can sneak different implementations in by implementing `Supertrait<NotActuallyTheSupertraitSubsts>` for a `dyn` type. This can be used to implement an unsound transmute function. See the committed test.

### How do we fix it?

We consider the whole trait ref when checking for supertraits. Right now, this is implemented using equality *without* normalization. We erase regions since those don't affect trait selection.

This is a limitation that could theoretically affect code that should be accepted, but doesn't matter in practice -- there are 0 crater regression. We could make this check stronger, but I would be worried about cycle issues. I assume that most people are writing `Self::Assoc` so they don't really care about the trait ref being normalized.

---

### What is up w the stacked commit

This is built on top of https://github.com/rust-lang/rust/pull/122804 though that's really not related, it's just easier to make this modification with the changes to the object safety code that I did in that PR. The only thing is that PR may make this unsoundness slightly easier to abuse, since there are more positions that allow self-associated-types -- I am happy to stall that change until this PR merges.

---

Fixes #126079

r? lcnr
2024-07-26 00:57:20 +02:00
bors
2f26b2a99a Auto merge of #127042 - GrigorenkoPV:derivative, r=compiler-errors
Switch from `derivative` to `derive-where`

This is a part of the effort to get rid of `syn 1.*` in compiler's dependencies: #109302

Derivative has not been maintained in nearly 3 years[^1]. It also depends on `syn 1.*`.

This PR replaces `derivative` with `derive-where`[^2], a not dead alternative, which uses `syn 2.*`.

A couple of `Debug` formats have changed around the skipped fields[^3], but I doubt this is an issue.

[^1]: https://github.com/mcarton/rust-derivative/issues/117
[^2]: https://lib.rs/crates/derive-where
[^3]: See the changes in `tests/ui`
2024-07-25 22:50:58 +00:00
Ben Kimock
f4f57bfccb Make Clone::clone a lang item 2024-07-25 18:46:07 -04:00
Julius Liu
e141b07164 fix: compilation issue w/ refactored type 2024-07-25 15:27:20 -07:00
bors
7120fdac7a Auto merge of #126963 - runtimeverification:smir_serde_derive, r=celinval
Add basic Serde serialization capabilities to Stable MIR

This PR adds basic Serde serialization capabilities to Stable MIR. It is intentionally minimal (just wrapping all stable MIR types with a Serde `derive`), so that any important design decisions can be discussed before going further. A simple test is included with this PR to validate that JSON can actually be emitted.

## Notes

When I wrapped the Stable MIR error types in `compiler/stable_mir/src/error.rs`, it caused test failures (though I'm not sure why) so I backed those out.

## Future Work

So, this PR will support serializing basic stable MIR, but it _does not_ support serializing interned values beneath `Ty`s and `AllocId`s, etc... My current thinking about how to handle this is as follows:

1.  Add new `visited_X` fields to the `Tables` struct for each interned category of interest.

2.  As serialization is occuring, serialize interned values as usual _and_ also record the interned value we referenced in `visited_X`.

    (Possibly) In addition, if an interned value recursively references other interned values, record those interned values as well.

3.  Teach the stable MIR `Context` how to access the `visited_X` values and expose them with wrappers in `stable_mir/src/lib.rs` to users (e.g. to serialize and/or further analyze them).

### Pros

This approach does not commit to any specific serialization format regarding interned values or other more complex cases, which avoids us locking into any behaviors that may not be desired long-term.

### Cons

The user will need to manually handle serializing interned values.

### Alternatives

1.  We can directly provide access to the underlying `Tables` maps for interned values; the disadvantage of this approach is that it either requires extra processing for users to filter out to only use the values that they need _or_ users may serialize extra values that they don't need. The advantage is that the implementation is even simpler. The other pros/cons are similar to the above.

2.  We can directly serialize interned values by expanding them in-place. The pro is that this may make some basic inputs easier to consume. However, the cons are that there will need to be special provisions for dealing with cyclical values on both the producer and consumer _and_ global values will possibly need to be de-duplicated on the consumer side.
2024-07-25 20:27:51 +00:00
Ben Kimock
a7d57aa7c8 Let InstCombine remove Clone shims inside Clone shims
Co-authored-by: scottmcm <scottmcm@users.noreply.github.com>
2024-07-25 15:14:42 -04:00
Boxy
8174f9b44b Stop using unsized_const_parameters in core/std 2024-07-25 19:47:21 +01:00
bors
aa877bc71c Auto merge of #128195 - matthiaskrgr:rollup-195dfdf, r=matthiaskrgr
Rollup of 6 pull requests

Successful merges:

 - #126908 (Use Cow<'static, str> for InlineAsmTemplatePiece::String)
 - #127999 (Inject arm32 shims into Windows metadata generation)
 - #128137 (CStr: derive PartialEq, Eq; add test for Ord)
 - #128185 (Fix a span error when parsing a wrong param of function.)
 - #128187 (Fix 1.80.0 version in RELEASES.md)
 - #128189 (Turn an unreachable code path into an ICE)

r? `@ghost`
`@rustbot` modify labels: rollup
2024-07-25 18:05:00 +00:00
Matthew Maurer
38931cd227 LLVM: LLVM-20.0 removes MMX types
See llvm/llvm-project#98505
2024-07-25 17:58:37 +00:00
Bryanskiy
2a73553513 Support ?Trait bounds in supertraits and dyn Trait under a feature gate 2024-07-25 20:53:33 +03:00
Matthias Krüger
cf1ce4beca
Rollup merge of #128189 - oli-obk:tainting_stuff, r=compiler-errors
Turn an unreachable code path into an ICE

We're probably replacing the resolution with a `Res::Err` nowadays instead of just erroring but keeping the `Res`, so this code path should be unreachable
2024-07-25 18:58:00 +02:00
Matthias Krüger
f378b4fd53
Rollup merge of #128187 - Urgau:fix-1.80.0-release-version, r=pietroalbini
Fix 1.80.0 version in RELEASES.md

https://rust-lang.zulipchat.com/#narrow/stream/241545-t-release/topic/1.2E80/near/453937871

r? ``@Mark-Simulacrum`` (or who ever wants)
Fixes https://github.com/rust-lang/rust/issues/128188
2024-07-25 18:57:59 +02:00
Matthias Krüger
9fd5679d52
Rollup merge of #128185 - surechen:fix_128042_2, r=compiler-errors
Fix a span error when parsing a wrong param of function.

fixes #128042

Before this change, the span of param `*mut Self` in  `fn oof(*mut Self)` contains `(` before it, so the suggestion in E0424 will be error.
2024-07-25 18:57:59 +02:00
Matthias Krüger
512277ff70
Rollup merge of #128137 - GrigorenkoPV:cstr-derive, r=dtolnay
CStr: derive PartialEq, Eq; add test for Ord

While working on #128046, I've spotted a peculiarity: `CStr` has `PartialEq, Eq, PartialOrd, Ord` implemented manually and not derived.

While we can't derive `PartialOrd, Ord` (due to inner `[c_char]` being `[i8]` or `[u8]` on different platforms), we *can* derive `PartialEq, Eq` (I think), allowing as to remove `#[allow(clippy::derived_hash_with_manual_eq)]` as well.

(I really hope `c_char: Eq` on all platforms)
2024-07-25 18:57:58 +02:00
Matthias Krüger
c96311bf8a
Rollup merge of #127999 - ChrisDenton:arm32, r=Amanieu
Inject arm32 shims into Windows metadata generation

I had been keen to eventually move to using windows-sys as a normal Cargo dependency. But for linking, compile times and other reasons that's unlikely to ever happen.

So if we're sticking with generated bindings then injecting any necessary missing type definitions (i.e. for the MS unsupported arm32) is simpler than defining whole functions ourselves just because we need to manually implement those types on a tier 3 platform. This also reduces the places we need to change when making changes to how we use `#[link]`.

r? libs
2024-07-25 18:57:57 +02:00
Matthias Krüger
155ba22f3c
Rollup merge of #126908 - GnomedDev:cow-inline-asm-temp-piece, r=compiler-errors
Use Cow<'static, str> for InlineAsmTemplatePiece::String

This removes a bunch of `&'static str -> String` allocations in codegen cranelift.
2024-07-25 18:57:56 +02:00
Philipp Krones
0949ff928a
Update Cargo.lock 2024-07-25 18:29:27 +02:00
Philipp Krones
b270543f8f
Merge commit '37f4fbb92913586b73a35772efd00eccd1cbbe13' into clippy-subtree-update 2024-07-25 18:29:17 +02:00
bors
37f4fbb929 Auto merge of #13157 - flip1995:rustup, r=flip1995
Rustup

r? `@ghost`

changelog: none
2024-07-25 16:25:19 +00:00