diff options
Diffstat (limited to 'src/test/ui/uninhabited')
11 files changed, 392 insertions, 0 deletions
diff --git a/src/test/ui/uninhabited/exhaustive-wo-nevertype-issue-51221.rs b/src/test/ui/uninhabited/exhaustive-wo-nevertype-issue-51221.rs new file mode 100644 index 000000000..b59432078 --- /dev/null +++ b/src/test/ui/uninhabited/exhaustive-wo-nevertype-issue-51221.rs @@ -0,0 +1,9 @@ +// check-pass + +#![feature(exhaustive_patterns)] + +enum Void {} +fn main() { + let a: Option<Void> = None; + let None = a; +} diff --git a/src/test/ui/uninhabited/privately-uninhabited-dead-code.rs b/src/test/ui/uninhabited/privately-uninhabited-dead-code.rs new file mode 100644 index 000000000..f476704cd --- /dev/null +++ b/src/test/ui/uninhabited/privately-uninhabited-dead-code.rs @@ -0,0 +1,20 @@ +// build-pass (FIXME(62277): could be check-pass?) + +#![deny(unused_variables)] + +mod foo { + enum Bar {} + + #[allow(dead_code)] + pub struct Foo { + value: Bar, // "privately" uninhabited + } + + pub fn give_foo() -> Foo { panic!() } +} + +fn main() { + let a = 42; + foo::give_foo(); + println!("Hello, {}", a); // ok: we can't tell that this code is dead +} diff --git a/src/test/ui/uninhabited/privately-uninhabited-mir-call.rs b/src/test/ui/uninhabited/privately-uninhabited-mir-call.rs new file mode 100644 index 000000000..2764bb563 --- /dev/null +++ b/src/test/ui/uninhabited/privately-uninhabited-mir-call.rs @@ -0,0 +1,29 @@ +// Verifies that MIR building for a call expression respects +// privacy when checking if a call return type is uninhabited. + +pub mod widget { + enum Unimplemented {} + pub struct Widget(Unimplemented); + + impl Widget { + pub fn new() -> Widget { + todo!(); + } + } + + pub fn f() { + let x: &mut u32; + Widget::new(); + // Ok. Widget type returned from new is known to be uninhabited + // and the following code is considered unreachable. + *x = 1; + } +} + +fn main() { + let y: &mut u32; + widget::Widget::new(); + // Error. Widget type is not known to be uninhabited here, + // so the following code is considered reachable. + *y = 2; //~ ERROR E0381 +} diff --git a/src/test/ui/uninhabited/privately-uninhabited-mir-call.stderr b/src/test/ui/uninhabited/privately-uninhabited-mir-call.stderr new file mode 100644 index 000000000..95c209f47 --- /dev/null +++ b/src/test/ui/uninhabited/privately-uninhabited-mir-call.stderr @@ -0,0 +1,12 @@ +error[E0381]: used binding `y` isn't initialized + --> $DIR/privately-uninhabited-mir-call.rs:28:5 + | +LL | let y: &mut u32; + | - binding declared here but left uninitialized +... +LL | *y = 2; + | ^^^^^^ `y` used here but it isn't initialized + +error: aborting due to previous error + +For more information about this error, try `rustc --explain E0381`. diff --git a/src/test/ui/uninhabited/uninhabited-enum-cast.rs b/src/test/ui/uninhabited/uninhabited-enum-cast.rs new file mode 100644 index 000000000..5a75c94c4 --- /dev/null +++ b/src/test/ui/uninhabited/uninhabited-enum-cast.rs @@ -0,0 +1,9 @@ +// check-pass + +enum E {} + +fn f(e: E) { + println!("{}", (e as isize).to_string()); +} + +fn main() {} diff --git a/src/test/ui/uninhabited/uninhabited-irrefutable.rs b/src/test/ui/uninhabited/uninhabited-irrefutable.rs new file mode 100644 index 000000000..661b5486a --- /dev/null +++ b/src/test/ui/uninhabited/uninhabited-irrefutable.rs @@ -0,0 +1,28 @@ +#![feature(never_type)] +#![feature(exhaustive_patterns)] + +mod foo { + pub struct SecretlyEmpty { + _priv: !, + } + + pub struct NotSoSecretlyEmpty { + pub _pub: !, + } +} + +struct NotSoSecretlyEmpty { + _priv: !, +} + +enum Foo { + A(foo::SecretlyEmpty), + B(foo::NotSoSecretlyEmpty), + C(NotSoSecretlyEmpty), + D(u32, u32), +} + +fn main() { + let x: Foo = Foo::D(123, 456); + let Foo::D(_y, _z) = x; //~ ERROR refutable pattern in local binding: `A(_)` not covered +} diff --git a/src/test/ui/uninhabited/uninhabited-irrefutable.stderr b/src/test/ui/uninhabited/uninhabited-irrefutable.stderr new file mode 100644 index 000000000..c571e17a7 --- /dev/null +++ b/src/test/ui/uninhabited/uninhabited-irrefutable.stderr @@ -0,0 +1,28 @@ +error[E0005]: refutable pattern in local binding: `A(_)` not covered + --> $DIR/uninhabited-irrefutable.rs:27:9 + | +LL | let Foo::D(_y, _z) = x; + | ^^^^^^^^^^^^^^ pattern `A(_)` not covered + | + = note: `let` bindings require an "irrefutable pattern", like a `struct` or an `enum` with only one variant + = note: for more information, visit https://doc.rust-lang.org/book/ch18-02-refutability.html +note: `Foo` defined here + --> $DIR/uninhabited-irrefutable.rs:19:5 + | +LL | enum Foo { + | --- +LL | A(foo::SecretlyEmpty), + | ^ not covered + = note: the matched value is of type `Foo` +help: you might want to use `if let` to ignore the variant that isn't matched + | +LL | let (_y, _z) = if let Foo::D(_y, _z) = x { (_y, _z) } else { todo!() }; + | +++++++++++++++++ +++++++++++++++++++++++++++++ +help: alternatively, on nightly, you might want to use `#![feature(let_else)]` to handle the variant that isn't matched + | +LL | let Foo::D(_y, _z) = x else { todo!() }; + | ++++++++++++++++ + +error: aborting due to previous error + +For more information about this error, try `rustc --explain E0005`. diff --git a/src/test/ui/uninhabited/uninhabited-matches-feature-gated.rs b/src/test/ui/uninhabited/uninhabited-matches-feature-gated.rs new file mode 100644 index 000000000..e804afcf9 --- /dev/null +++ b/src/test/ui/uninhabited/uninhabited-matches-feature-gated.rs @@ -0,0 +1,39 @@ +use std::mem::zeroed; +enum Void {} + +fn main() { + let x: Result<u32, &'static Void> = Ok(23); + let _ = match x { //~ ERROR non-exhaustive + Ok(n) => n, + }; + + // This is pretty much instant UB. However, we have no choice -- we need to + // test matching on a reference to `&Void`; we cannot do anything other than + // just accept the fact that this is UB if `main` did run, but it doesn't; + // this test only checks that these are feature-gated. + let x: &Void = unsafe { zeroed() }; + let _ = match x {}; //~ ERROR non-exhaustive + + let x: (Void,) = unsafe { zeroed() }; + let _ = match x {}; //~ ERROR non-exhaustive + + let x: [Void; 1] = unsafe { zeroed() }; + let _ = match x {}; //~ ERROR non-exhaustive + + let x: &[Void] = unsafe { zeroed() }; + let _ = match x { //~ ERROR non-exhaustive + &[] => (), + }; + + let x: Void = unsafe { zeroed() }; + let _ = match x {}; // okay + + let x: Result<u32, Void> = Ok(23); + let _ = match x { //~ ERROR non-exhaustive + Ok(x) => x, + }; + + let x: Result<u32, Void> = Ok(23); + let Ok(x) = x; + //~^ ERROR refutable +} diff --git a/src/test/ui/uninhabited/uninhabited-matches-feature-gated.stderr b/src/test/ui/uninhabited/uninhabited-matches-feature-gated.stderr new file mode 100644 index 000000000..2c107b1f7 --- /dev/null +++ b/src/test/ui/uninhabited/uninhabited-matches-feature-gated.stderr @@ -0,0 +1,133 @@ +error[E0004]: non-exhaustive patterns: `Err(_)` not covered + --> $DIR/uninhabited-matches-feature-gated.rs:6:19 + | +LL | let _ = match x { + | ^ pattern `Err(_)` not covered + | +note: `Result<u32, &Void>` defined here + --> $SRC_DIR/core/src/result.rs:LL:COL + | +LL | pub enum Result<T, E> { + | --------------------- +... +LL | Err(#[stable(feature = "rust1", since = "1.0.0")] E), + | ^^^ not covered + = note: the matched value is of type `Result<u32, &Void>` +help: ensure that all possible cases are being handled by adding a match arm with a wildcard pattern or an explicit pattern as shown + | +LL ~ Ok(n) => n, +LL ~ Err(_) => todo!(), + | + +error[E0004]: non-exhaustive patterns: type `&Void` is non-empty + --> $DIR/uninhabited-matches-feature-gated.rs:15:19 + | +LL | let _ = match x {}; + | ^ + | +note: `Void` defined here + --> $DIR/uninhabited-matches-feature-gated.rs:2:6 + | +LL | enum Void {} + | ^^^^ + = note: the matched value is of type `&Void` + = note: references are always considered inhabited +help: ensure that all possible cases are being handled by adding a match arm with a wildcard pattern as shown + | +LL ~ let _ = match x { +LL + _ => todo!(), +LL ~ }; + | + +error[E0004]: non-exhaustive patterns: type `(Void,)` is non-empty + --> $DIR/uninhabited-matches-feature-gated.rs:18:19 + | +LL | let _ = match x {}; + | ^ + | + = note: the matched value is of type `(Void,)` +help: ensure that all possible cases are being handled by adding a match arm with a wildcard pattern as shown + | +LL ~ let _ = match x { +LL + _ => todo!(), +LL ~ }; + | + +error[E0004]: non-exhaustive patterns: type `[Void; 1]` is non-empty + --> $DIR/uninhabited-matches-feature-gated.rs:21:19 + | +LL | let _ = match x {}; + | ^ + | + = note: the matched value is of type `[Void; 1]` +help: ensure that all possible cases are being handled by adding a match arm with a wildcard pattern as shown + | +LL ~ let _ = match x { +LL + _ => todo!(), +LL ~ }; + | + +error[E0004]: non-exhaustive patterns: `&[_, ..]` not covered + --> $DIR/uninhabited-matches-feature-gated.rs:24:19 + | +LL | let _ = match x { + | ^ pattern `&[_, ..]` not covered + | + = note: the matched value is of type `&[Void]` +help: ensure that all possible cases are being handled by adding a match arm with a wildcard pattern or an explicit pattern as shown + | +LL ~ &[] => (), +LL ~ &[_, ..] => todo!(), + | + +error[E0004]: non-exhaustive patterns: `Err(_)` not covered + --> $DIR/uninhabited-matches-feature-gated.rs:32:19 + | +LL | let _ = match x { + | ^ pattern `Err(_)` not covered + | +note: `Result<u32, Void>` defined here + --> $SRC_DIR/core/src/result.rs:LL:COL + | +LL | pub enum Result<T, E> { + | --------------------- +... +LL | Err(#[stable(feature = "rust1", since = "1.0.0")] E), + | ^^^ not covered + = note: the matched value is of type `Result<u32, Void>` +help: ensure that all possible cases are being handled by adding a match arm with a wildcard pattern or an explicit pattern as shown + | +LL ~ Ok(x) => x, +LL ~ Err(_) => todo!(), + | + +error[E0005]: refutable pattern in local binding: `Err(_)` not covered + --> $DIR/uninhabited-matches-feature-gated.rs:37:9 + | +LL | let Ok(x) = x; + | ^^^^^ pattern `Err(_)` not covered + | + = note: `let` bindings require an "irrefutable pattern", like a `struct` or an `enum` with only one variant + = note: for more information, visit https://doc.rust-lang.org/book/ch18-02-refutability.html +note: `Result<u32, Void>` defined here + --> $SRC_DIR/core/src/result.rs:LL:COL + | +LL | pub enum Result<T, E> { + | --------------------- +... +LL | Err(#[stable(feature = "rust1", since = "1.0.0")] E), + | ^^^ not covered + = note: the matched value is of type `Result<u32, Void>` +help: you might want to use `if let` to ignore the variant that isn't matched + | +LL | let x = if let Ok(x) = x { x } else { todo!() }; + | ++++++++++ ++++++++++++++++++++++ +help: alternatively, on nightly, you might want to use `#![feature(let_else)]` to handle the variant that isn't matched + | +LL | let Ok(x) = x else { todo!() }; + | ++++++++++++++++ + +error: aborting due to 7 previous errors + +Some errors have detailed explanations: E0004, E0005. +For more information about an error, try `rustc --explain E0004`. diff --git a/src/test/ui/uninhabited/uninhabited-patterns.rs b/src/test/ui/uninhabited/uninhabited-patterns.rs new file mode 100644 index 000000000..f1573b6ad --- /dev/null +++ b/src/test/ui/uninhabited/uninhabited-patterns.rs @@ -0,0 +1,47 @@ +#![feature(box_patterns)] +#![feature(never_type)] +#![feature(exhaustive_patterns)] + + +#![deny(unreachable_patterns)] + +mod foo { + pub struct SecretlyEmpty { + _priv: !, + } +} + +struct NotSoSecretlyEmpty { + _priv: !, +} + +fn foo() -> Option<NotSoSecretlyEmpty> { + None +} + +fn main() { + let x: &[!] = &[]; + + match x { + &[] => (), + &[..] => (), //~ ERROR unreachable pattern + }; + + let x: Result<Box<NotSoSecretlyEmpty>, &[Result<!, !>]> = Err(&[]); + match x { + Ok(box _) => (), //~ ERROR unreachable pattern + Err(&[]) => (), + Err(&[..]) => (), //~ ERROR unreachable pattern + } + + let x: Result<foo::SecretlyEmpty, Result<NotSoSecretlyEmpty, u32>> = Err(Err(123)); + match x { + Ok(_y) => (), + Err(Err(_y)) => (), + Err(Ok(_y)) => (), //~ ERROR unreachable pattern + } + + while let Some(_y) = foo() { + //~^ ERROR unreachable pattern + } +} diff --git a/src/test/ui/uninhabited/uninhabited-patterns.stderr b/src/test/ui/uninhabited/uninhabited-patterns.stderr new file mode 100644 index 000000000..655569ad6 --- /dev/null +++ b/src/test/ui/uninhabited/uninhabited-patterns.stderr @@ -0,0 +1,38 @@ +error: unreachable pattern + --> $DIR/uninhabited-patterns.rs:27:9 + | +LL | &[..] => (), + | ^^^^^ + | +note: the lint level is defined here + --> $DIR/uninhabited-patterns.rs:6:9 + | +LL | #![deny(unreachable_patterns)] + | ^^^^^^^^^^^^^^^^^^^^ + +error: unreachable pattern + --> $DIR/uninhabited-patterns.rs:32:9 + | +LL | Ok(box _) => (), + | ^^^^^^^^^ + +error: unreachable pattern + --> $DIR/uninhabited-patterns.rs:34:9 + | +LL | Err(&[..]) => (), + | ^^^^^^^^^^ + +error: unreachable pattern + --> $DIR/uninhabited-patterns.rs:41:9 + | +LL | Err(Ok(_y)) => (), + | ^^^^^^^^^^^ + +error: unreachable pattern + --> $DIR/uninhabited-patterns.rs:44:15 + | +LL | while let Some(_y) = foo() { + | ^^^^^^^^ + +error: aborting due to 5 previous errors + |