rust/tests/ui/structs-enums/enum-rec/issue-17431-6.rs

use std::cell::UnsafeCell;

enum Foo { X(UnsafeCell<Option<Foo>>) }
//~^ ERROR recursive type `Foo` has infinite size
//~| ERROR cycle detected

impl Foo { fn bar(self) {} }

fn main() {}
make UI test OS-agnostic the internal representation of `std::sync::Mutex` depends on the compilation target. due to this, the compiler produces different number of errors for UI test `issue-17431-6.rs` depending on the compilation target. for example, when compiling the UI test to an `-apple-` or `-qnx7` target, the "cycle detected" error is not reported ``` console $ cat src/lib.rs use std::sync::Mutex; enum Foo { X(Mutex<Option<Foo>>), } impl Foo { fn bar(self) {} } fn main() {} $ cargo check --target x86_64-apple-ios 2>&1 \| rg '^error\[' error[E0072]: recursive type `Foo` has infinite size ``` whereas rustc produces two errors for other OSes, like Linux, which is what the UI test expects ``` console $ cargo check --target x86_64-unknown-linux-gnu 2>&1 \| rg '^error\[' error[E0072]: recursive type `Foo` has infinite size error[E0391]: cycle detected when computing when `Foo` needs drop ``` this commit replaces the problematic `Mutex` with `UnsafeCell`, which has the same internal representation regardless of the compilation target. with that change, rustc reports two errors for all compilation targets. ``` console $ cat src/lib.rs use std::cell::UnsafeCell; enum Foo { X(UnsafeCell<Option<Foo>>), } impl Foo { fn bar(self) {} } fn main() {} $ cargo check --target x86_64-apple-ios 2>&1 \| rg '^error\[' error[E0072]: recursive type `Foo` has infinite size error[E0391]: cycle detected when computing when `Foo` needs drop ``` with this change, we can remove the `ignore-apple` directive as the UI test now also passes on apple targets. 2024-11-15 15:36:30 +00:00			`use std::cell::UnsafeCell;`
Continue to borrowck even if there were previous errors 2024-02-01 22:45:00 +00:00
make UI test OS-agnostic the internal representation of `std::sync::Mutex` depends on the compilation target. due to this, the compiler produces different number of errors for UI test `issue-17431-6.rs` depending on the compilation target. for example, when compiling the UI test to an `-apple-` or `-qnx7` target, the "cycle detected" error is not reported ``` console $ cat src/lib.rs use std::sync::Mutex; enum Foo { X(Mutex<Option<Foo>>), } impl Foo { fn bar(self) {} } fn main() {} $ cargo check --target x86_64-apple-ios 2>&1 \| rg '^error\[' error[E0072]: recursive type `Foo` has infinite size ``` whereas rustc produces two errors for other OSes, like Linux, which is what the UI test expects ``` console $ cargo check --target x86_64-unknown-linux-gnu 2>&1 \| rg '^error\[' error[E0072]: recursive type `Foo` has infinite size error[E0391]: cycle detected when computing when `Foo` needs drop ``` this commit replaces the problematic `Mutex` with `UnsafeCell`, which has the same internal representation regardless of the compilation target. with that change, rustc reports two errors for all compilation targets. ``` console $ cat src/lib.rs use std::cell::UnsafeCell; enum Foo { X(UnsafeCell<Option<Foo>>), } impl Foo { fn bar(self) {} } fn main() {} $ cargo check --target x86_64-apple-ios 2>&1 \| rg '^error\[' error[E0072]: recursive type `Foo` has infinite size error[E0391]: cycle detected when computing when `Foo` needs drop ``` with this change, we can remove the `ignore-apple` directive as the UI test now also passes on apple targets. 2024-11-15 15:36:30 +00:00			`enum Foo { X(UnsafeCell<Option<Foo>>) }`
Detect cycles and specialize error reporting for Sized. It is important to get the `Sized` error usable, since that hits new users frequently. Further work is needed for the error reporting for non-Sized cycle cases; those currently just fallback to the old path. Also adjust tests. 2016-01-09 02:41:37 +00:00			//~^ ERROR recursive type `Foo` has infinite size
Continue to borrowck even if there were previous errors 2024-02-01 22:45:00 +00:00			`//~\| ERROR cycle detected`
Fix several issues with the struct and enum representability-checking logic. 2014-10-06 06:20:25 +00:00
			`impl Foo { fn bar(self) {} }`

			`fn main() {}`