shadowed label false positive in closure #31754

durka · 2016-02-18T18:18:00Z

It seems that #27093 did not fully fix #25343. The following code reports a spurious warning on 'b:

'a: loop { break; }
'b: loop { break; }

// no warning
fn does_not_shadow() {
    'a: loop {}
}

// false positive
let also_does_not_shadow = || {
    'b: loop {}
};

Stable, beta, nightly.

The text was updated successfully, but these errors were encountered:

This should fix rust-lang#31754 and follow-up rust-lang#25343. Before the latter, the closure was visited twice in the context of the enclosing fn, which made even a single closure with a loop label emit a warning. With this change, the closure is still visited within the context of the main fn (which is intended, since it is not a separate item) but resets the found loop labels while being visited. Fixes: rust-lang#31754

@Manishearth

middle: reset loop labels while visiting closure This should fix rust-lang#31754 and follow-up rust-lang#25343. Before the latter, the closure was visited twice in the context of the enclosing fn, which made even a single closure with a loop label emit a warning. With this change, the closure is still visited within the context of the main fn (which is intended, since it is not a separate item) but resets the found loop labels while being visited. Fixes: rust-lang#31754 Note: I amended the test file from rust-lang#25343, but I don't know if the original or amended test are effective, since as far as I could see, compiletest's run-pass tests do not check for zero warnings emitted? /cc @Manishearth

@Manishearth

middle: reset loop labels while visiting closure This should fix rust-lang#31754 and follow-up rust-lang#25343. Before the latter, the closure was visited twice in the context of the enclosing fn, which made even a single closure with a loop label emit a warning. With this change, the closure is still visited within the context of the main fn (which is intended, since it is not a separate item) but resets the found loop labels while being visited. Fixes: rust-lang#31754 Note: I amended the test file from rust-lang#25343, but I don't know if the original or amended test are effective, since as far as I could see, compiletest's run-pass tests do not check for zero warnings emitted? /cc @Manishearth

@Manishearth

middle: reset loop labels while visiting closure This should fix rust-lang#31754 and follow-up rust-lang#25343. Before the latter, the closure was visited twice in the context of the enclosing fn, which made even a single closure with a loop label emit a warning. With this change, the closure is still visited within the context of the main fn (which is intended, since it is not a separate item) but resets the found loop labels while being visited. Fixes: rust-lang#31754 Note: I amended the test file from rust-lang#25343, but I don't know if the original or amended test are effective, since as far as I could see, compiletest's run-pass tests do not check for zero warnings emitted? /cc @Manishearth

steveklabnik added the A-diagnostics Area: Messages for errors, warnings, and lints label Mar 11, 2016

birkenfeld mentioned this issue May 2, 2016

middle: reset loop labels while visiting closure #33345

Merged

bors closed this as completed in #33345 May 11, 2016

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shadowed label false positive in closure #31754

shadowed label false positive in closure #31754

durka commented Feb 18, 2016

shadowed label false positive in closure #31754

shadowed label false positive in closure #31754

Comments

durka commented Feb 18, 2016