Suggest move for closures and async blocks in more cases. #70906
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| @@ -1225,8 +1204,9 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> { | |||
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| let msg = match category { | |||
| ConstraintCategory::Return => "closure is returned here".to_string(), | |||
| ConstraintCategory::OpaqueType => "generator is returned here".to_string(), | |||
| ConstraintCategory::Return | ConstraintCategory::OpaqueType => { | |||
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I feel the existing behavior is wrong, users of async should not see generator in error messages.
But not sure what wording should be used instead.
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I think that we'll 1) need to be able to differentiate between closures and generators here in the first place and 2) in the OpaqueType it should be "async closure is returned here", right?
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Agreed that saying generators in an error message is basically never right, regardless.
| category: | ||
| category | ||
| @ | ||
| (ConstraintCategory::Return | ||
| | ConstraintCategory::CallArgument | ||
| | ConstraintCategory::OpaqueType), |
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Highlighting this for a rustfmt issue (rust-lang/rustfmt#4110) I'm filing (no need to do anything about it in this PR).
| error[E0373]: closure may outlive the current function, but it borrows `x`, which is owned by the current function | ||
| --> $DIR/async-borrowck-escaping-block-error.rs:11:11 | ||
| | | ||
| LL | async { *x } | ||
| | ^^^-^^ | ||
| | | | | ||
| | | `x` is borrowed here | ||
| | may outlive borrowed value `x` | ||
| | | ||
| note: closure is returned here | ||
| --> $DIR/async-borrowck-escaping-block-error.rs:11:5 | ||
| | | ||
| LL | async { *x } | ||
| | ^^^^^^^^^^^^ | ||
| help: to force the async block to take ownership of `x` (and any other referenced variables), use the `move` keyword | ||
| | | ||
| LL | async move { *x } | ||
| | ^^^^^^^^^^^ |
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Actually, I think the output here should talk about closures, it should talk about async blocks instead (same in the previously existing test):
error[E0373]: async block may outlive the current function, but it borrows `x`, which is owned by the current function
--> $DIR/async-borrowck-escaping-block-error.rs:11:11
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LL | async { *x }
| ^^^-^^
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| | `x` is borrowed here
| may outlive borrowed value `x`
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note: async block is returned here
--> $DIR/async-borrowck-escaping-block-error.rs:11:5
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LL | async { *x }
| ^^^^^^^^^^^^
help: to force the async block to take ownership of `x` (and any other referenced variables), use the `move` keyword
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LL | async move { *x }
| ^^^^^^^^^^^
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@bors r+ |
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📌 Commit aaebbe1 has been approved by |
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Rollup of 7 pull requests Successful merges: - rust-lang#70134 (add basic support of OsStrExt for HermitCore) - rust-lang#70565 (Add inline attributes for functions used in the query system) - rust-lang#70828 (rustdoc: Don't try to load source files from external crates) - rust-lang#70870 (Fix abuses of tykind::err) - rust-lang#70906 (Suggest move for closures and async blocks in more cases.) - rust-lang#70912 (Do not suggest adding type param when `use` is already suggested) - rust-lang#70930 (add tracking issue to `VecDeque::make_contiguous`) Failed merges: r? @ghost
Fixes #66107, also improves #67577
Related PR #65166