ac922245f0
The SCCs of the region graph are not a reliable heuristic to use for blaming an interesting constraint for diagnostics. For region errors, if the outlived region is `'static`, or the involved types are invariant in their lifetiems, there will be cycles in the constraint graph containing both the target region and the most interesting constraints to blame. To get better diagnostics in these cases, this commit removes that heuristic.
37 lines
1.5 KiB
Plaintext
37 lines
1.5 KiB
Plaintext
error[E0597]: `foo` does not live long enough
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--> $DIR/issue-90600-expected-return-static-indirect.rs:7:32
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LL | fn inner(mut foo: &[u8]) {
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| ------- binding `foo` declared here
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LL | let refcell = RefCell::new(&mut foo);
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| ^^^^^^^^ borrowed value does not live long enough
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...
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LL | read_thing(read);
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| ---------------- argument requires that `foo` is borrowed for `'static`
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LL |
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LL | }
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| - `foo` dropped here while still borrowed
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error[E0521]: borrowed data escapes outside of function
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--> $DIR/issue-90600-expected-return-static-indirect.rs:11:5
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LL | fn inner(mut foo: &[u8]) {
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| ------- - let's call the lifetime of this reference `'1`
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| |
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| `foo` is a reference that is only valid in the function body
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...
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LL | read_thing(read);
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| ^^^^^^^^^^^^^^^^
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| |
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| `foo` escapes the function body here
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| argument requires that `'1` must outlive `'static`
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= note: requirement occurs because of the type `RefCell<(dyn std::io::Read + 'static)>`, which makes the generic argument `(dyn std::io::Read + 'static)` invariant
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= note: the struct `RefCell<T>` is invariant over the parameter `T`
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= help: see <https://doc.rust-lang.org/nomicon/subtyping.html> for more information about variance
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error: aborting due to 2 previous errors
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Some errors have detailed explanations: E0521, E0597.
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For more information about an error, try `rustc --explain E0521`.
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