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6 files changed, 269 insertions, 0 deletions
diff --git a/tests/ui/pattern/deref-patterns/usefulness/empty-types.rs b/tests/ui/pattern/deref-patterns/usefulness/empty-types.rs new file mode 100644 index 00000000000..03419030e72 --- /dev/null +++ b/tests/ui/pattern/deref-patterns/usefulness/empty-types.rs @@ -0,0 +1,47 @@ +//! Test that the place behind a deref pattern is treated as maybe-invalid, and thus empty arms +//! cannot be omitted. This is handled the same as for refs and union fields, so this leaves the +//! bulk of the testing to `tests/ui/pattern/usefulness/empty-types.rs`. +// FIXME(deref_patterns): On stabilization, cases for deref patterns could be worked into that file +// to keep the tests for empty types in one place and test more thoroughly. +#![feature(deref_patterns)] +#![expect(incomplete_features)] +#![deny(unreachable_patterns)] + +enum Void {} + +fn main() { + // Sanity check: matching on an empty type without pointer indirection lets us omit arms. + let opt_void: Option<Void> = None; + match opt_void { + None => {} + } + + // But if we hide it behind a smart pointer, we need an arm. + let box_opt_void: Box<Option<Void>> = Box::new(None); + match box_opt_void { + //~^ ERROR non-exhaustive patterns: `deref!(Some(_))` not covered + None => {} + } + match box_opt_void { + None => {} + Some(_) => {} + } + match box_opt_void { + None => {} + _ => {} + } + + // For consistency, this behaves the same as if we manually dereferenced the scrutinee. + match *box_opt_void { + //~^ ERROR non-exhaustive patterns: `Some(_)` not covered + None => {} + } + match *box_opt_void { + None => {} + Some(_) => {} + } + match *box_opt_void { + None => {} + _ => {} + } +} diff --git a/tests/ui/pattern/deref-patterns/usefulness/empty-types.stderr b/tests/ui/pattern/deref-patterns/usefulness/empty-types.stderr new file mode 100644 index 00000000000..e3247708566 --- /dev/null +++ b/tests/ui/pattern/deref-patterns/usefulness/empty-types.stderr @@ -0,0 +1,38 @@ +error[E0004]: non-exhaustive patterns: `deref!(Some(_))` not covered + --> $DIR/empty-types.rs:21:11 + | +LL | match box_opt_void { + | ^^^^^^^^^^^^ pattern `deref!(Some(_))` not covered + | +note: `Box<Option<Void>>` defined here + --> $SRC_DIR/alloc/src/boxed.rs:LL:COL + = note: the matched value is of type `Box<Option<Void>>` + = note: `Void` is uninhabited but is not being matched by value, so a wildcard `_` is required +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 ~ None => {}, +LL + deref!(Some(_)) => todo!() + | + +error[E0004]: non-exhaustive patterns: `Some(_)` not covered + --> $DIR/empty-types.rs:35:11 + | +LL | match *box_opt_void { + | ^^^^^^^^^^^^^ pattern `Some(_)` not covered + | +note: `Option<Void>` defined here + --> $SRC_DIR/core/src/option.rs:LL:COL + ::: $SRC_DIR/core/src/option.rs:LL:COL + | + = note: not covered + = note: the matched value is of type `Option<Void>` + = note: `Void` is uninhabited but is not being matched by value, so a wildcard `_` is required +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 ~ None => {}, +LL + Some(_) => todo!() + | + +error: aborting due to 2 previous errors + +For more information about this error, try `rustc --explain E0004`. diff --git a/tests/ui/pattern/deref-patterns/usefulness/non-exhaustive.rs b/tests/ui/pattern/deref-patterns/usefulness/non-exhaustive.rs new file mode 100644 index 00000000000..704cae8bdbc --- /dev/null +++ b/tests/ui/pattern/deref-patterns/usefulness/non-exhaustive.rs @@ -0,0 +1,28 @@ +//! Test non-exhaustive matches involving deref patterns. +#![feature(deref_patterns)] +#![expect(incomplete_features)] +#![deny(unreachable_patterns)] + +fn main() { + match Box::new(false) { + //~^ ERROR non-exhaustive patterns: `deref!(true)` not covered + false => {} + } + + match Box::new(Box::new(false)) { + //~^ ERROR non-exhaustive patterns: `deref!(deref!(false))` not covered + true => {} + } + + match Box::new((true, Box::new(false))) { + //~^ ERROR non-exhaustive patterns: `deref!((false, deref!(false)))` and `deref!((true, deref!(true)))` not covered + (true, false) => {} + (false, true) => {} + } + + enum T { A, B, C } + match Box::new((Box::new(T::A), Box::new(T::A))) { + //~^ ERROR non-exhaustive patterns: `deref!((deref!(T::C), _))` not covered + (T::A | T::B, T::C) => {} + } +} diff --git a/tests/ui/pattern/deref-patterns/usefulness/non-exhaustive.stderr b/tests/ui/pattern/deref-patterns/usefulness/non-exhaustive.stderr new file mode 100644 index 00000000000..55fa84bafde --- /dev/null +++ b/tests/ui/pattern/deref-patterns/usefulness/non-exhaustive.stderr @@ -0,0 +1,63 @@ +error[E0004]: non-exhaustive patterns: `deref!(true)` not covered + --> $DIR/non-exhaustive.rs:7:11 + | +LL | match Box::new(false) { + | ^^^^^^^^^^^^^^^ pattern `deref!(true)` not covered + | +note: `Box<bool>` defined here + --> $SRC_DIR/alloc/src/boxed.rs:LL:COL + = note: the matched value is of type `Box<bool>` +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 ~ false => {}, +LL + deref!(true) => todo!() + | + +error[E0004]: non-exhaustive patterns: `deref!(deref!(false))` not covered + --> $DIR/non-exhaustive.rs:12:11 + | +LL | match Box::new(Box::new(false)) { + | ^^^^^^^^^^^^^^^^^^^^^^^^^ pattern `deref!(deref!(false))` not covered + | +note: `Box<Box<bool>>` defined here + --> $SRC_DIR/alloc/src/boxed.rs:LL:COL + = note: the matched value is of type `Box<Box<bool>>` +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 ~ true => {}, +LL + deref!(deref!(false)) => todo!() + | + +error[E0004]: non-exhaustive patterns: `deref!((false, deref!(false)))` and `deref!((true, deref!(true)))` not covered + --> $DIR/non-exhaustive.rs:17:11 + | +LL | match Box::new((true, Box::new(false))) { + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ patterns `deref!((false, deref!(false)))` and `deref!((true, deref!(true)))` not covered + | +note: `Box<(bool, Box<bool>)>` defined here + --> $SRC_DIR/alloc/src/boxed.rs:LL:COL + = note: the matched value is of type `Box<(bool, Box<bool>)>` +help: ensure that all possible cases are being handled by adding a match arm with a wildcard pattern, a match arm with multiple or-patterns as shown, or multiple match arms + | +LL ~ (false, true) => {}, +LL + deref!((false, deref!(false))) | deref!((true, deref!(true))) => todo!() + | + +error[E0004]: non-exhaustive patterns: `deref!((deref!(T::C), _))` not covered + --> $DIR/non-exhaustive.rs:24:11 + | +LL | match Box::new((Box::new(T::A), Box::new(T::A))) { + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ pattern `deref!((deref!(T::C), _))` not covered + | +note: `Box<(Box<T>, Box<T>)>` defined here + --> $SRC_DIR/alloc/src/boxed.rs:LL:COL + = note: the matched value is of type `Box<(Box<T>, Box<T>)>` +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 ~ (T::A | T::B, T::C) => {}, +LL + deref!((deref!(T::C), _)) => todo!() + | + +error: aborting due to 4 previous errors + +For more information about this error, try `rustc --explain E0004`. diff --git a/tests/ui/pattern/deref-patterns/usefulness/unreachable-patterns.rs b/tests/ui/pattern/deref-patterns/usefulness/unreachable-patterns.rs new file mode 100644 index 00000000000..2677fc54ded --- /dev/null +++ b/tests/ui/pattern/deref-patterns/usefulness/unreachable-patterns.rs @@ -0,0 +1,33 @@ +//! Test unreachable patterns involving deref patterns. +#![feature(deref_patterns)] +#![expect(incomplete_features)] +#![deny(unreachable_patterns)] + +fn main() { + match Box::new(false) { + true => {} + false => {} + false => {} //~ ERROR unreachable pattern + } + + match Box::new(Box::new(false)) { + true => {} + false => {} + true => {} //~ ERROR unreachable pattern + } + + match Box::new((true, Box::new(false))) { + (true, _) => {} + (_, true) => {} + (false, false) => {} + _ => {} //~ ERROR unreachable pattern + } + + enum T { A, B, C } + match Box::new((Box::new(T::A), Box::new(T::A))) { + (T::A | T::B, T::A | T::C) => {} + (T::A, T::C) => {} //~ ERROR unreachable pattern + (T::B, T::A) => {} //~ ERROR unreachable pattern + _ => {} + } +} diff --git a/tests/ui/pattern/deref-patterns/usefulness/unreachable-patterns.stderr b/tests/ui/pattern/deref-patterns/usefulness/unreachable-patterns.stderr new file mode 100644 index 00000000000..045e11be319 --- /dev/null +++ b/tests/ui/pattern/deref-patterns/usefulness/unreachable-patterns.stderr @@ -0,0 +1,60 @@ +error: unreachable pattern + --> $DIR/unreachable-patterns.rs:10:9 + | +LL | false => {} + | ----- matches all the relevant values +LL | false => {} + | ^^^^^ no value can reach this + | +note: the lint level is defined here + --> $DIR/unreachable-patterns.rs:4:9 + | +LL | #![deny(unreachable_patterns)] + | ^^^^^^^^^^^^^^^^^^^^ + +error: unreachable pattern + --> $DIR/unreachable-patterns.rs:16:9 + | +LL | true => {} + | ---- matches all the relevant values +LL | false => {} +LL | true => {} + | ^^^^ no value can reach this + +error: unreachable pattern + --> $DIR/unreachable-patterns.rs:23:9 + | +LL | _ => {} + | ^ no value can reach this + | +note: multiple earlier patterns match some of the same values + --> $DIR/unreachable-patterns.rs:23:9 + | +LL | (true, _) => {} + | --------- matches some of the same values +LL | (_, true) => {} + | --------- matches some of the same values +LL | (false, false) => {} + | -------------- matches some of the same values +LL | _ => {} + | ^ collectively making this unreachable + +error: unreachable pattern + --> $DIR/unreachable-patterns.rs:29:9 + | +LL | (T::A | T::B, T::A | T::C) => {} + | -------------------------- matches all the relevant values +LL | (T::A, T::C) => {} + | ^^^^^^^^^^^^ no value can reach this + +error: unreachable pattern + --> $DIR/unreachable-patterns.rs:30:9 + | +LL | (T::A | T::B, T::A | T::C) => {} + | -------------------------- matches all the relevant values +LL | (T::A, T::C) => {} +LL | (T::B, T::A) => {} + | ^^^^^^^^^^^^ no value can reach this + +error: aborting due to 5 previous errors + |