diff --git a/compiler/rustc_mir_build/src/thir/pattern/usefulness.rs b/compiler/rustc_mir_build/src/thir/pattern/usefulness.rs index be66d0d4765..9edd7967e7a 100644 --- a/compiler/rustc_mir_build/src/thir/pattern/usefulness.rs +++ b/compiler/rustc_mir_build/src/thir/pattern/usefulness.rs @@ -300,6 +300,7 @@ use rustc_arena::TypedArena; use rustc_data_structures::stack::ensure_sufficient_stack; use rustc_hir::def_id::DefId; use rustc_hir::HirId; +use rustc_hir::Node; use rustc_middle::ty::{self, Ty, TyCtxt}; use rustc_session::lint::builtin::NON_EXHAUSTIVE_OMITTED_PATTERNS; use rustc_span::{Span, DUMMY_SP}; @@ -867,6 +868,8 @@ fn is_useful<'p, 'tcx>( &ctor, Constructor::Missing { nonexhaustive_enum_missing_real_variants: true } ) + // We don't want to lint patterns which are function arguments or locals + && !matches!(cx.tcx.hir().find_parent(hir_id), Some(Node::Param(_)|Node::Local(_))) { let patterns = { let mut split_wildcard = SplitWildcard::new(pcx); diff --git a/tests/ui/rfc-2008-non-exhaustive/omitted-patterns.rs b/tests/ui/rfc-2008-non-exhaustive/omitted-patterns.rs index d8f07bb8f24..7ef1d635d9c 100644 --- a/tests/ui/rfc-2008-non-exhaustive/omitted-patterns.rs +++ b/tests/ui/rfc-2008-non-exhaustive/omitted-patterns.rs @@ -184,4 +184,20 @@ fn main() { // OK: both unstable and stable fields are matched with feature on #[warn(non_exhaustive_omitted_patterns)] let UnstableStruct { stable, stable2, unstable, .. } = UnstableStruct::default(); + + // Ok: local bindings are allowed + #[deny(non_exhaustive_omitted_patterns)] + let local = NonExhaustiveEnum::Unit; + + // Ok: missing patterns will be blocked by the pattern being refutable + #[deny(non_exhaustive_omitted_patterns)] + let local_refutable @ NonExhaustiveEnum::Unit = NonExhaustiveEnum::Unit; + //~^ refutable pattern in local binding + +} + +#[deny(non_exhaustive_omitted_patterns)] +// Ok: Pattern in a param is always wildcard +pub fn takes_non_exhaustive(_: NonExhaustiveEnum) { + let _closure = |_: NonExhaustiveEnum| {}; } diff --git a/tests/ui/rfc-2008-non-exhaustive/omitted-patterns.stderr b/tests/ui/rfc-2008-non-exhaustive/omitted-patterns.stderr index 996bd4a1298..617c629a4fe 100644 --- a/tests/ui/rfc-2008-non-exhaustive/omitted-patterns.stderr +++ b/tests/ui/rfc-2008-non-exhaustive/omitted-patterns.stderr @@ -184,5 +184,20 @@ note: the lint level is defined here LL | #[deny(non_exhaustive_omitted_patterns)] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ -error: aborting due to 8 previous errors; 6 warnings emitted +error[E0005]: refutable pattern in local binding + --> $DIR/omitted-patterns.rs:194:9 + | +LL | let local_refutable @ NonExhaustiveEnum::Unit = NonExhaustiveEnum::Unit; + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ pattern `_` 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: the matched value is of type `NonExhaustiveEnum` +help: you might want to use `let else` to handle the variant that isn't matched + | +LL | let local_refutable @ NonExhaustiveEnum::Unit = NonExhaustiveEnum::Unit else { todo!() }; + | ++++++++++++++++ +error: aborting due to 9 previous errors; 6 warnings emitted + +For more information about this error, try `rustc --explain E0005`.