Rollup of 8 pull requests#94734

matthiaskrgr · 2022-03-08T10:04:57Z

Successful merges:

Tweak output for non-exhaustive match expression #91993 (Tweak output for non-exhaustive match expression)
Add Result::{ok, err, and, or, unwrap_or} as const #92385 (Add Result::{ok, err, and, or, unwrap_or} as const)
Remove argument from closure in thread::Scope::spawn. #94559 (Remove argument from closure in thread::Scope::spawn.)
Emit unused_attributes if a level attr only has a reason #94580 (Emit unused_attributes if a level attr only has a reason)
Generalize get_nullable_type to allow types where null is all-ones. #94586 (Generalize get_nullable_type to allow types where null is all-ones.)
diagnostics: only talk about Cargo.toml if running under Cargo #94708 (diagnostics: only talk about Cargo.toml if running under Cargo)
promot debug_assert to assert #94712 (promot debug_assert to assert)
⬆️ rust-analyzer #94726 (:arrow_up: rust-analyzer)

Failed merges:

r? @ghost
@rustbot modify labels: rollup

Generalize get_nullable_type to accept types that have an all-ones bit pattern as their sentry "null" value. This will allow [`OwnedFd`], [`BorrowedFd`], [`OwnedSocket`], and [`BorrowedSocket`] to be marked with `#[rustc_nonnull_optimization_guaranteed]`, which will allow `Option<OwnedFd>`, `Option<BorrowedFd>`, `Option<OwnedSocket>`, and `Option<BorrowedSocket>` to be used in FFI declarations, as described in the [I/O safety RFC]. For example, it will allow a function like `open` on Unix and `WSASocketW` on Windows to be declared using `Option<OwnedFd>` and `Option<OwnedSocket>` return types, respectively. The actual change to add `#[rustc_nonnull_optimization_guaranteed]` to the abovementioned types will be a separate PR, as it'll depend on having this patch in the stage0 compiler. Also, update the diagnostics to mention that "niche optimizations" are used in libstd as well as libcore, as `rustc_layout_scalar_valid_range_start` and `rustc_layout_scalar_valid_range_end` are already in use in libstd. [`OwnedFd`]: https://github.com/rust-lang/rust/blob/c9dc44be24c58ff13ce46416c4b97ab5c1bd8429/library/std/src/os/fd/owned.rs#L49 [`BorrowedFd`]: https://github.com/rust-lang/rust/blob/c9dc44be24c58ff13ce46416c4b97ab5c1bd8429/library/std/src/os/fd/owned.rs#L29 [`OwnedSocket`]: https://github.com/rust-lang/rust/blob/c9dc44be24c58ff13ce46416c4b97ab5c1bd8429/library/std/src/os/windows/io/socket.rs#L51 [`BorrowedSocket`]: https://github.com/rust-lang/rust/blob/c9dc44be24c58ff13ce46416c4b97ab5c1bd8429/library/std/src/os/windows/io/socket.rs#L29 [I/O safety RFC]: https://github.com/rust-lang/rfcs/blob/master/text/3128-io-safety.md#ownedfd-and-borrowedfdfd-1

Co-authored-by: Daniel Henry-Mantilla <daniel.henry.mantilla@gmail.com>

Fixes rust-lang#94646

Co-authored-by: Mark Rousskov <mark.simulacrum@gmail.com>

Given ```rust match Some(42) {} ``` suggest ```rust match Some(42) { None | Some(_) => todo!(), } ```

…st it Given ```rust match Some(42) { Some(0) => {} } ``` suggest ```rust match Some(42) { Some(0) => {} None | Some(_) => todo!(), } ```

…est it Given ```rust match Some(42) { Some(0) => {} Some(1) => {} } ``` suggest ```rust match Some(42) { Some(0) => {} Some(1) => {} None | Some(_) => todo!(), } ```

… `span_label` This makes the order of the output always consistent: 1. Place of the `match` missing arms 2. The `enum` definition span 3. The structured suggestion to add a fallthrough arm

…li-obk Tweak output for non-exhaustive `match` expression * Provide structured suggestion when missing `match` arms * Move pointing at the missing variants *after* the main error <img width="1164" alt="" src="https://user-images.githubusercontent.com/1606434/146312085-b57ef4a3-6e96-4f32-aa2a-803637d9eeba.png">

Add Result::{ok, err, and, or, unwrap_or} as const Already opened tracking issue rust-lang#92384. I don't think that this should actually cause any issues as long as the constness is unstable, but we may want to double-check that this doesn't get interpreted as a weird `Drop` bound even for non-const usages.

…without-arg, r=Mark-Simulacrum Remove argument from closure in thread::Scope::spawn. This implements ```@danielhenrymantilla's``` [suggestion](rust-lang#93203 (comment)) for improving the scoped threads interface. Summary: The `Scope` type gets an extra lifetime argument, which represents basically its own lifetime that will be used in `&'scope Scope<'scope, 'env>`: ```diff - pub struct Scope<'env> { .. }; + pub struct Scope<'scope, 'env: 'scope> { .. } pub fn scope<'env, F, T>(f: F) -> T where - F: FnOnce(&Scope<'env>) -> T; + F: for<'scope> FnOnce(&'scope Scope<'scope, 'env>) -> T; ``` This simplifies the `spawn` function, which now no longer passes an argument to the closure you give it, and now uses the `'scope` lifetime for everything: ```diff - pub fn spawn<'scope, F, T>(&'scope self, f: F) -> ScopedJoinHandle<'scope, T> + pub fn spawn<F, T>(&'scope self, f: F) -> ScopedJoinHandle<'scope, T> where - F: FnOnce(&Scope<'env>) -> T + Send + 'env, + F: FnOnce() -> T + Send + 'scope, - T: Send + 'env; + T: Send + 'scope; ``` The only difference the user will notice, is that their closure now takes no arguments anymore, even when spawning threads from spawned threads: ```diff thread::scope(|s| { - s.spawn(|_| { + s.spawn(|| { ... }); - s.spawn(|s| { + s.spawn(|| { ... - s.spawn(|_| ...); + s.spawn(|| ...); }); }); ``` <details><summary>And, as a bonus, errors get <em>slightly</em> better because now any lifetime issues point to the outermost <code>s</code> (since there is only one <code>s</code>), rather than the innermost <code>s</code>, making it clear that the lifetime lasts for the entire <code>thread::scope</code>. </summary> ```diff error[E0373]: closure may outlive the current function, but it borrows `a`, which is owned by the current function --> src/main.rs:9:21 | - 7 | s.spawn(|s| { - | - has type `&Scope<'1>` + 6 | thread::scope(|s| { + | - lifetime `'1` appears in the type of `s` 9 | s.spawn(|| println!("{:?}", a)); // might run after `a` is dropped | ^^ - `a` is borrowed here | | | may outlive borrowed value `a` | note: function requires argument type to outlive `'1` --> src/main.rs:9:13 | 9 | s.spawn(|| println!("{:?}", a)); // might run after `a` is dropped | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: to force the closure to take ownership of `a` (and any other referenced variables), use the `move` keyword | 9 | s.spawn(move || println!("{:?}", a)); // might run after `a` is dropped | ++++ " ``` </details> The downside is that the signature of `scope` and `Scope` gets slightly more complex, but in most cases the user wouldn't need to write those, as they just use the argument provided by `thread::scope` without having to name its type. Another downside is that this does not work nicely in Rust 2015 and Rust 2018, since in those editions, `s` would be captured by reference and not by copy. In those editions, the user would need to use `move ||` to capture `s` by copy. (Which is what the compiler suggests in the error.)

…attr, r=lcnr Emit `unused_attributes` if a level attr only has a reason Fixes a comment from `compiler/rustc_lint/src/levels.rs`. Lint level attributes that only contain a reason will also trigger the `unused_attribute` lint. The lint now also checks for the `expect` lint level. That's it, have a great rest of the day for everyone reasoning this 🙃 cc: rust-lang#55112

…s-tests, r=davidtwco Generalize `get_nullable_type` to allow types where null is all-ones. Generalize get_nullable_type to accept types that have an all-ones bit pattern as their sentry "null" value. This will allow [`OwnedFd`], [`BorrowedFd`], [`OwnedSocket`], and [`BorrowedSocket`] to be marked with `#[rustc_nonnull_optimization_guaranteed]`, which will allow `Option<OwnedFd>`, `Option<BorrowedFd>`, `Option<OwnedSocket>`, and `Option<BorrowedSocket>` to be used in FFI declarations, as described in the [I/O safety RFC]. For example, it will allow a function like `open` on Unix and `WSASocketW` on Windows to be declared using `Option<OwnedFd>` and `Option<OwnedSocket>` return types, respectively. The actual change to add `#[rustc_nonnull_optimization_guaranteed]` to the abovementioned types will be a separate PR, as it'll depend on having this patch in the stage0 compiler. Also, update the diagnostics to mention that "niche optimizations" are used in libstd as well as libcore, as `rustc_layout_scalar_valid_range_start` and `rustc_layout_scalar_valid_range_end` are already in use in libstd. [`OwnedFd`]: https://github.com/rust-lang/rust/blob/c9dc44be24c58ff13ce46416c4b97ab5c1bd8429/library/std/src/os/fd/owned.rs#L49 [`BorrowedFd`]: https://github.com/rust-lang/rust/blob/c9dc44be24c58ff13ce46416c4b97ab5c1bd8429/library/std/src/os/fd/owned.rs#L29 [`OwnedSocket`]: https://github.com/rust-lang/rust/blob/c9dc44be24c58ff13ce46416c4b97ab5c1bd8429/library/std/src/os/windows/io/socket.rs#L51 [`BorrowedSocket`]: https://github.com/rust-lang/rust/blob/c9dc44be24c58ff13ce46416c4b97ab5c1bd8429/library/std/src/os/windows/io/socket.rs#L29 [I/O safety RFC]: https://github.com/rust-lang/rfcs/blob/master/text/3128-io-safety.md#ownedfd-and-borrowedfdfd-1

…ing, r=lcnr diagnostics: only talk about `Cargo.toml` if running under Cargo Fixes rust-lang#94646

…sumption, r=Mark-Simulacrum promot debug_assert to assert Fixes rust-lang#94705

…=lnicola ⬆️ rust-analyzer r? `@ghost`

matthiaskrgr · 2022-03-08T10:05:59Z

@bors r+ rollup=never p=8

bors · 2022-03-08T10:06:00Z

📌 Commit b879216 has been approved by matthiaskrgr

bors · 2022-03-08T10:24:58Z

⌛ Testing commit b879216 with merge b97dc20...

bors · 2022-03-08T12:44:59Z

☀️ Test successful - checks-actions
Approved by: matthiaskrgr
Pushing b97dc20 to master...

rust-timer · 2022-03-08T16:55:03Z

Finished benchmarking commit (b97dc20): comparison url.

Summary: This benchmark run did not return any relevant results.

If you disagree with this performance assessment, please file an issue in rust-lang/rustc-perf.

@rustbot label: -perf-regression

clarfonthey and others added 23 commits January 29, 2022 18:37

Add Result::{ok, err, and, or, unwrap_or} as const

19645ac

Remove argument from closure in thread::Scope::spawn.

24fe35a

Fix doctests.

6b46a52

Emit unused_attributes if a level attr only has a reason

700ec66

Use '_ for irrelevant lifetimes in Debug impl.

9099353

Co-authored-by: Daniel Henry-Mantilla <daniel.henry.mantilla@gmail.com>

diagnostics: only talk about Cargo.toml if running under Cargo

fbd4cfa

Fixes rust-lang#94646

promot debug_assert to assert

776be7e

Use f instead of || f().

a3d269e

Co-authored-by: Mark Rousskov <mark.simulacrum@gmail.com>

When encountering a match expr with no arms, suggest it

02a3830

Given ```rust match Some(42) {} ``` suggest ```rust match Some(42) { None | Some(_) => todo!(), } ```

When finding a match expr with a single arm that requires more, sugge…

2383858

…st it Given ```rust match Some(42) { Some(0) => {} } ``` suggest ```rust match Some(42) { Some(0) => {} None | Some(_) => todo!(), } ```

When finding a match expr with multiple arms that requires more, sugg…

084ca79

…est it Given ```rust match Some(42) { Some(0) => {} Some(1) => {} } ``` suggest ```rust match Some(42) { Some(0) => {} Some(1) => {} None | Some(_) => todo!(), } ```

Point at uncovered variants in enum definition in note instead of a…

ab4feea

… `span_label` This makes the order of the output always consistent: 1. Place of the `match` missing arms 2. The `enum` definition span 3. The structured suggestion to add a fallthrough arm

Change wording of suggestion to add missing match arm

6f45f73

⬆️ rust-analyzer

a3158c7

Rollup merge of rust-lang#94708 - notriddle:notriddle/cargo-toml-warn…

98d027c

…ing, r=lcnr diagnostics: only talk about `Cargo.toml` if running under Cargo Fixes rust-lang#94646

Rollup merge of rust-lang#94712 - kckeiks:remove-rwlock-read-error-as…

a077e44

…sumption, r=Mark-Simulacrum promot debug_assert to assert Fixes rust-lang#94705

Rollup merge of rust-lang#94726 - lnicola:rust-analyzer-2022-03-08, r…

b879216

…=lnicola ⬆️ rust-analyzer r? `@ghost`

rustbot added T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. rollup A PR which is a rollup labels Mar 8, 2022

bors added the S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. label Mar 8, 2022

bors added the merged-by-bors This PR was explicitly merged by bors. label Mar 8, 2022

bors merged commit b97dc20 into rust-lang:master Mar 8, 2022

rustbot added this to the 1.61.0 milestone Mar 8, 2022

This was referenced Mar 8, 2022

Fix exposing fields marked unstable or doc hidden #90358

Merged

Use modern formatting for format! macros #93950

Merged

matthiaskrgr deleted the rollup-28shqhy branch March 11, 2022 15:31

apiraino mentioned this pull request Aug 31, 2022

E0004 says "note: Option<i32> defined here" when it's not #101068

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Rollup of 8 pull requests#94734