Rollup merge of #102207 - CraftSpider:const-layout, r=scottmcm
Constify remaining `Layout` methods
Makes the methods on `Layout` that aren't yet unstably const, under the same feature and issue, #67521. Most of them required no changes, only non-trivial change is probably constifying `ValidAlignment` which may affect #102072
Rollup merge of #95583 - scottmcm:deprecate-ptr-to-from-bits, r=dtolnay
Deprecate the unstable `ptr_to_from_bits` feature
I propose that we deprecate the (unstable!) `to_bits` and `from_bits` methods on raw pointers. (With the intent to ~~remove them once `addr` has been around long enough to make the transition easy on people -- maybe another 6 weeks~~ remove them fairly soon after, as the strict and expose versions have been around for a while already.)
The APIs that came from the strict provenance explorations (#95228) are a more holistic version of these, and things like `.expose_addr()` work for the "that cast looks sketchy" case even if the full strict provenance stuff never happens. (As a bonus, `addr` is even shorter than `to_bits`, though it is only applicable if people can use full strict provenance! `addr` is *not* a direct replacement for `to_bits`.) So I think it's fine to move away from the `{to|from}_bits` methods, and encourage the others instead.
That also resolves the worry that was brought up (I forget where) that `q.to_bits()` and `(*q).to_bits()` both work if `q` is a pointer-to-floating-point, as they also have a `to_bits` method.
Rollup merge of #83608 - Kimundi:index_many, r=Mark-Simulacrum
Add slice methods for indexing via an array of indices.
Disclaimer: It's been a while since I contributed to the main Rust repo, apologies in advance if this is large enough already that it should've been an RFC.
---
# Update:
- Based on feedback, removed the `&[T]` variant of this API, and removed the requirements for the indices to be sorted.
This allows creating multiple mutable references to disjunct positions in a slice, which previously required writing some awkward code with `split_at_mut()` or `iter_mut()`. For the bound-checked variant, the indices are checked against each other and against the bounds of the slice, which requires `N * (N + 1) / 2` comparison operations.
This has a proof-of-concept standalone implementation here: https://crates.io/crates/index_many
Care has been taken that the implementation passes miri borrow checks, and generates straight-forward assembly (though this was only checked on x86_64).
# Example
```rust
let v = &mut [1, 2, 3, 4];
let [a, b] = v.get_many_mut([0, 2]).unwrap();
std::mem::swap(a, b);
*v += 100;
assert_eq!(v, &[3, 2, 101, 4]);
```
# Codegen Examples
<details>
<summary>Click to expand!</summary>
Disclaimer: Taken from local tests with the standalone implementation.
This could easily be expanded to allow indexing with `[I; N]` where `I: SliceIndex<Self>`. I wanted to keep the initial implementation simple, so I didn't include it yet.
This would work similar to the regular index operator and panic with out-of-bound indices. The advantage would be that we could more easily ensure good codegen with a useful panic message, which is non-trivial with the `Option` variant.
This is implemented in the standalone implementation, and used as basis for the codegen examples here and there.
bors [Tue, 22 Nov 2022 01:35:57 +0000 (01:35 +0000)]
Auto merge of #104696 - matthiaskrgr:rollup-gi1pdb0, r=matthiaskrgr
Rollup of 11 pull requests
Successful merges:
- #103396 (Pin::new_unchecked: discuss pinning closure captures)
- #104416 (Fix using `include_bytes` in pattern position)
- #104557 (Add a test case for async dyn* traits)
- #104559 (Split `MacArgs` in two.)
- #104597 (Probe + better error messsage for `need_migrate_deref_output_trait_object`)
- #104656 (Move tests)
- #104657 (Do not check transmute if has non region infer)
- #104663 (rustdoc: factor out common button CSS)
- #104666 (Migrate alias search result to CSS variables)
- #104674 (Make negative_impl and negative_impl_exists take the right types)
- #104692 (Update test's cfg-if dependency to 1.0)
Matthias Krüger [Mon, 21 Nov 2022 23:01:09 +0000 (00:01 +0100)]
Rollup merge of #104597 - compiler-errors:need_migrate_deref_output_trait_object-msg, r=eholk
Probe + better error messsage for `need_migrate_deref_output_trait_object`
1. Use `InferCtxt::probe` in `need_migrate_deref_output_trait_object` -- that normalization *could* technically do type inference as a side-effect, and this is a lint, so it should have no side-effects.
2. Return the trait-ref so we format the error message correctly. See the UI test change -- `(dyn A + 'static)` is not a trait.
Matthias Krüger [Mon, 21 Nov 2022 23:01:09 +0000 (00:01 +0100)]
Rollup merge of #104559 - nnethercote:split-MacArgs, r=petrochenkov
Split `MacArgs` in two.
`MacArgs` is an enum with three variants: `Empty`, `Delimited`, and `Eq`. It's used in two ways:
- For representing attribute macro arguments (e.g. in `AttrItem`), where all three variants are used.
- For representing function-like macros (e.g. in `MacCall` and `MacroDef`), where only the `Delimited` variant is used.
In other words, `MacArgs` is used in two quite different places due to them having partial overlap. I find this makes the code hard to read. It also leads to various unreachable code paths, and allows invalid values (such as accidentally using `MacArgs::Empty` in a `MacCall`).
This commit splits `MacArgs` in two:
- `DelimArgs` is a new struct just for the "delimited arguments" case. It is now used in `MacCall` and `MacroDef`.
- `AttrArgs` is a renaming of the old `MacArgs` enum for the attribute macro case. Its `Delimited` variant now contains a `DelimArgs`.
Various other related things are renamed as well.
These changes make the code clearer, avoids several unreachable paths, and disallows the invalid values.
Matthias Krüger [Mon, 21 Nov 2022 23:01:08 +0000 (00:01 +0100)]
Rollup merge of #104557 - eholk:dyn-star-in-traits, r=compiler-errors
Add a test case for async dyn* traits
This adds a test case that approximates async functions in dyn traits using `dyn*`. The purpose is to have an example of where we are with `dyn*` and the goal of using it for dyn traits.
Regardless of how the discussion in https://github.com/rust-lang/rust/pull/102737 turns out, pinning closure captures is super subtle business and probably worth discussing separately.
`MacArgs` is an enum with three variants: `Empty`, `Delimited`, and `Eq`. It's
used in two ways:
- For representing attribute macro arguments (e.g. in `AttrItem`), where all
three variants are used.
- For representing function-like macros (e.g. in `MacCall` and `MacroDef`),
where only the `Delimited` variant is used.
In other words, `MacArgs` is used in two quite different places due to them
having partial overlap. I find this makes the code hard to read. It also leads
to various unreachable code paths, and allows invalid values (such as
accidentally using `MacArgs::Empty` in a `MacCall`).
This commit splits `MacArgs` in two:
- `DelimArgs` is a new struct just for the "delimited arguments" case. It is
now used in `MacCall` and `MacroDef`.
- `AttrArgs` is a renaming of the old `MacArgs` enum for the attribute macro
case. Its `Delimited` variant now contains a `DelimArgs`.
Various other related things are renamed as well.
These changes make the code clearer, avoids several unreachable paths, and
disallows the invalid values.
bors [Mon, 21 Nov 2022 15:22:54 +0000 (15:22 +0000)]
Auto merge of #104673 - matthiaskrgr:rollup-85f65ov, r=matthiaskrgr
Rollup of 9 pull requests
Successful merges:
- #104420 (Fix doc example for `wrapping_abs`)
- #104499 (rustdoc JSON: Use `Function` everywhere and remove `Method`)
- #104500 (`rustc_ast`: remove `ref` patterns)
- #104511 (Mark functions created for `raw-dylib` on x86 with DllImport storage class)
- #104595 (Add `PolyExistentialPredicate` type alias)
- #104605 (deduplicate constant evaluation in cranelift backend)
- #104628 (Revert "Update CI to use Android NDK r25b")
- #104662 (Streamline deriving on packed structs.)
- #104667 (Revert formatting changes of a test)
Matthias Krüger [Mon, 21 Nov 2022 13:11:13 +0000 (14:11 +0100)]
Rollup merge of #104662 - nnethercote:tweak-deriving-for-packed-non-copy, r=jackh726
Streamline deriving on packed structs.
The current approach to field accesses in derived code:
- Normal case: `&self.0`
- In a packed struct that derives `Copy`: `&{self.0}`
- In a packed struct that doesn't derive `Copy`: `let Self(ref x) = *self`
The `let` pattern used in the third case is equivalent to the simpler field access in the first case. This commit changes the third case to use a field access.
The commit also combines two boolean arguments (`is_packed` and `always_copy`) into a single field (`copy_fields`) earlier, to save passing both around.
The relevant discussion can be found in #103673, where it was agreed that more time is needed to warn the community of the upcoming breakage.
This PR is for the `master` branch, where a conflict was recently introduced due to 6d8160261ff3aee3b6eaacc37ac96cafff530980. The conflict is in `cc_detect.rs`, where the code that corrects the target triple was moved to a new function called `ndk_compiler()`. This puts the old logic in the `ndk_compiler` function, and assumes that it works properly in the other location where that code is being called. I would appreciate review from ``@pietroalbini`` to understand how we can test that the reverted logic is also suitable for the additional use case (seems to be related to setting `cc` and `cxx`). I've confirmed already that with these changes I can compile for `armv7-linux-androideabi`, `aarch64-linux-android`, `i686-linux-android`, and `x86_64-linux-android` using `x.py`.
A separate revert for the `beta` branch will be required, since the original change has already made it to beta. The beta revert is available at https://github.com/alex-pinkus/rust/commit/3fa0d94674fbe37090ebe44ac1f06e2233f3121e, but I'm not sure of the process for staging that PR.
Matthias Krüger [Mon, 21 Nov 2022 13:11:12 +0000 (14:11 +0100)]
Rollup merge of #104605 - RalfJung:clf_consts, r=bjorn3
deduplicate constant evaluation in cranelift backend
The cranelift backend had two matches on `ConstantKind`, which can be avoided, and used this `eval_for_mir` that nothing else uses... this makes things more consistent with the (better-tested) LLVM backend.
I noticed this because cranelift was the only user of `eval_for_mir`. However `try_eval_for_mir` still has one other user in `eval`... the odd thing is that the interpreter has its own `eval_mir_constant` which seems to duplicate the same functionality and does not use `try_eval_for_mir`. No idea what is happening here.
Matthias Krüger [Mon, 21 Nov 2022 13:11:10 +0000 (14:11 +0100)]
Rollup merge of #104511 - dpaoliello:privateglobalworkaround, r=michaelwoerister
Mark functions created for `raw-dylib` on x86 with DllImport storage class
Fix for #104453
## Issue Details
On x86 Windows, LLVM uses 'L' as the prefix for any private global symbols (`PrivateGlobalPrefix`), so when the `raw-dylib` feature creates an undecorated function symbol that begins with an 'L' LLVM misinterprets that as a private global symbol that it created and so fails the compilation at a later stage since such a symbol must have a definition.
## Fix Details
Mark the function we are creating for `raw-dylib` with `DllImport` storage class (this was already being done for MSVC at a later point for `callee::get_fn` but not for GNU (due to "backwards compatibility")): this will cause LLVM to prefix the name with `__imp_` and so it won't mistake it for a private global symbol.
Matthias Krüger [Mon, 21 Nov 2022 13:11:10 +0000 (14:11 +0100)]
Rollup merge of #104500 - WaffleLapkin:deref-the-compiler, r=wesleywiser
`rustc_ast`: remove `ref` patterns
Or in other words use match ergonomics in `rustc_ast`. I do plan to do the same with other crates, but to keep the diff sane, let's do them one at a time.
Matthias Krüger [Mon, 21 Nov 2022 13:11:09 +0000 (14:11 +0100)]
Rollup merge of #104420 - TethysSvensson:master, r=JohnTitor
Fix doc example for `wrapping_abs`
The `max` variable is unused. This change introduces the `min_plus` variable, to make the example similar to the one from `saturating_abs`. An alternative would be to remove the unused variable.
bors [Mon, 21 Nov 2022 12:17:03 +0000 (12:17 +0000)]
Auto merge of #103491 - cjgillot:self-rpit, r=oli-obk
Support using `Self` or projections inside an RPIT/async fn
I reuse the same idea as https://github.com/rust-lang/rust/pull/103449 to use variances to encode whether a lifetime parameter is captured by impl-trait.
The current implementation of async and RPIT replace all lifetimes from the parent generics by `'static`. This PR changes the scheme
```rust
impl<'a> Foo<'a> {
fn foo<'b, T>() -> impl Into<Self> + 'b { ... }
}
// NEW
fn foo<'b, T>() -> Foo::<'a>::foo::<'b, T>::opaque::<'b> { ... }
^^ the `Self` stays `Foo<'a>`
}
```
There is the same issue with projections. In the example, substitute `Self` by `<T as Trait<'b>>::Assoc` in the sugared version, and `Foo<'_a>` by `<T as Trait<'_b>>::Assoc` in the desugared one.
This allows to support `Self` in impl-trait, since we do not replace lifetimes by `'static` any more. The same trick allows to use projections like `T::Assoc` where `Self` is allowed. The feature is gated behind a `impl_trait_projections` feature gate.
The implementation relies on 2 tweaking rules for opaques in 2 places:
- we only relate substs that correspond to captured lifetimes during TypeRelation;
- we only list captured lifetimes in choice region computation.
For simplicity, I encoded the "capturedness" of lifetimes as a variance, `Bivariant` vs `Invariant` for unused vs captured lifetimes. The `variances_of` query used to ICE for opaques.
Impl-trait that do not reference `Self` or projections will have their variances as:
- `o` (invariant) for each parent type or const;
- `*` (bivariant) for each parent lifetime --> will not participate in borrowck;
- `o` (invariant) for each own lifetime.
Impl-trait that does reference `Self` and/or projections will have some parent lifetimes marked as `o` (as the example above), and participate in type relation and borrowck. In the example above, `variances_of(opaque) = ['_a: o, '_b: *, T: o, 'b: o]`.
r? types
cc `@compiler-errors` , as you asked about the issue with `Self` and projections.
The current approach to field accesses in derived code:
- Normal case: `&self.0`
- In a packed struct that derives `Copy`: `&{self.0}`
- In a packed struct that doesn't derive `Copy`: `let Self(ref x) = *self`
The `let` pattern used in the third case is equivalent to the simpler
field access in the first case. This commit changes the third case to
use a field access.
The commit also combines two boolean arguments (`is_packed` and
`always_copy`) into a single field (`copy_fields`) earlier, to save
passing both around.
bors [Mon, 21 Nov 2022 01:44:12 +0000 (01:44 +0000)]
Auto merge of #102717 - beetrees:repr128-c-style-debuginfo, r=nagisa
Pass 128-bit C-style enum enumerator values to LLVM
Pass the full 128 bits of C-style enum enumerators through to LLVM. This means that debuginfo for C-style repr128 enums is now emitted correctly for DWARF platforms (as compared to not being correctly emitted on any platform).
Matthias Krüger [Sun, 20 Nov 2022 22:50:30 +0000 (23:50 +0100)]
Rollup merge of #104643 - pnkfelix:examples-for-chunks-remainder, r=scottmcm
add examples to chunks remainder methods.
add examples to chunks remainder methods.
my motivation for adding the examples was to make it very clear that the state of the iterator (in terms of where its cursor lies) has no effect on what remainder returns.
Also fixed some links to rchunk remainder methods.
Matthias Krüger [Sun, 20 Nov 2022 22:50:28 +0000 (23:50 +0100)]
Rollup merge of #104581 - notriddle:notriddle/js-iife-2, r=GuillaumeGomez
rustdoc: remove unused JS IIFE from main.js
This [IIFE] made sense when it was added in deaf5e200e79a75ac57d3f0952f6758a38168e52 and there was a local variable scoped to it, but now it calls a function, but declares nothing.
[IIFE]: https://developer.mozilla.org/en-US/docs/Glossary/IIFE "immediately invoked function expression"
Matthias Krüger [Sun, 20 Nov 2022 22:50:27 +0000 (23:50 +0100)]
Rollup merge of #104504 - compiler-errors:fru-syntax-note, r=estebank
Add a detailed note for missing comma typo w/ FRU syntax
Thanks to `@pierwill` for working on this with me!
Fixes #104373, perhaps `@alice-i-cecile` can comment on the new error for the example provided on that issue -- feedback is welcome.
```
error[E0063]: missing field `defaulted` in initializer of `Outer`
--> $DIR/multi-line-fru-suggestion.rs:14:5
|
LL | Outer {
| ^^^^^ missing `defaulted`
|
note: this expression may have been misinterpreted as a `..` range expression
--> $DIR/multi-line-fru-suggestion.rs:16:16
|
LL | inner: Inner {
| ________________^
LL | | a: 1,
LL | | b: 2,
LL | | }
| |_________^ this expression does not end in a comma...
LL | ..Default::default()
| ^^^^^^^^^^^^^^^^^^^^ ... so this is interpreted as a `..` range expression, instead of functional record update syntax
help: to set the remaining fields from `Default::default()`, separate the last named field with a comma
|
LL | },
| +
error: aborting due to previous error
For more information about this error, try `rustc --explain E0063`.
```
Matthias Krüger [Sun, 20 Nov 2022 22:50:27 +0000 (23:50 +0100)]
Rollup merge of #104487 - klensy:ntapi, r=Mark-Simulacrum
update ntapi dep to remove future-incompat warning
This fixes warning https://github.com/rust-lang-ci/rust/actions/runs/3477235400/jobs/5813202075#step:25:217
`warning: the following packages contain code that will be rejected by a future version of Rust: ntapi v0.3.7`
by upgrading `sysinfo` version (https://github.com/GuillaumeGomez/sysinfo/blob/master/CHANGELOG.md#0267)
There was some breaking changes in `sysinfo`:
* 0.25.0 (System::refresh_cpu behaviour changed: it only computes CPU usage and doesn't retrieve CPU frequency.) not affected?
* 0.26.0 (Switch memory unit from kilobytes to bytes) fixed.
Matthias Krüger [Sun, 20 Nov 2022 22:50:26 +0000 (23:50 +0100)]
Rollup merge of #101310 - zachs18:rc_get_unchecked_mut_docs_soundness, r=Mark-Simulacrum
Clarify and restrict when `{Arc,Rc}::get_unchecked_mut` is allowed.
(Tracking issue for `{Arc,Rc}::get_unchecked_mut`: #63292)
(I'm using `Rc` in this comment, but it applies for `Arc` all the same).
As currently documented, `Rc::get_unchecked_mut` can lead to unsoundness when multiple `Rc`/`Weak` pointers to the same allocation exist. The current documentation only requires that other `Rc`/`Weak` pointers to the same allocation "must not be dereferenced for the duration of the returned borrow". This can lead to unsoundness in (at least) two ways: variance, and `Rc<str>`/`Rc<[u8]>` aliasing. ([playground link](https://play.rust-lang.org/?version=nightly&mode=debug&edition=2021&gist=d7e2d091c389f463d121630ab0a37320)).
This PR changes the documentation of `Rc::get_unchecked_mut` to restrict usage to when all `Rc<T>`/`Weak<T>` have the exact same `T` (including lifetimes). I believe this is sufficient to prevent unsoundness, while still allowing `get_unchecked_mut` to be called on an aliased `Rc` as long as the safety contract is upheld by the caller.
## Alternatives
* A less strict, but still sound alternative would be to say that the caller must only write values which are valid for all aliased `Rc`/`Weak` inner types. (This was [mentioned](https://github.com/rust-lang/rust/issues/63292#issuecomment-568284090) in the tracking issue). This may be too complicated to clearly express in the documentation.
* A more strict alternative would be to say that there must not be any aliased `Rc`/`Weak` pointers, i.e. it is required that get_mut would return `Some(_)`. (This was also mentioned in the tracking issue). There is at least one codebase that this would cause to become unsound ([here](https://github.com/kaimast/lsm-rs/blob/be5a164d770d850d905e510e2966ad4b1cc9aa5e/src/memtable.rs#L166), where additional locking is used to ensure unique access to an aliased `Rc<T>`; I saw this because it was linked on the tracking issue).
bors [Sun, 20 Nov 2022 19:14:14 +0000 (19:14 +0000)]
Auto merge of #104646 - matthiaskrgr:rollup-7xnhzf0, r=matthiaskrgr
Rollup of 6 pull requests
Successful merges:
- #104537 (fix std::thread docs are unclear regarding stack sizes)
- #104558 (Don't assume `FILE_ID_BOTH_DIR_INFO` will be aligned)
- #104564 (interpret: use Either over Result when it is not representing an error condition)
- #104568 (clarify that realloc refreshes pointer provenance even when the allocation remains in-place)
- #104611 (rustdoc: use real buttons for scrape examples controls)
- #104640 (Migrate kdb style to CSS variables)