diff options
8 files changed, 132 insertions, 2 deletions
diff --git a/compiler/rustc_middle/src/ty/inhabitedness/mod.rs b/compiler/rustc_middle/src/ty/inhabitedness/mod.rs index 855e5043e84..32988965a35 100644 --- a/compiler/rustc_middle/src/ty/inhabitedness/mod.rs +++ b/compiler/rustc_middle/src/ty/inhabitedness/mod.rs @@ -43,6 +43,7 @@ //! This code should only compile in modules where the uninhabitedness of `Foo` //! is visible. +use rustc_span::sym; use rustc_type_ir::TyKind::*; use tracing::instrument; @@ -84,6 +85,21 @@ impl<'tcx> VariantDef { InhabitedPredicate::all( tcx, self.fields.iter().map(|field| { + // Unstable fields are always considered to be inhabited. In the future, + // this could be extended to be conditional on the field being unstable + // only within the module that's querying the inhabitedness, like: + // `let pred = pred.or(InhabitedPredicate::IsUnstable(field.did));` + // but this is unnecessary for now, since it would only affect nightly-only + // code or code within the standard library itself. + // HACK: We filter out `rustc_private` fields since with the flag + // `-Zforce-unstable-if-unmarked` we consider all unmarked fields to be + // unstable when building the compiler. + if tcx + .lookup_stability(field.did) + .is_some_and(|stab| stab.is_unstable() && stab.feature != sym::rustc_private) + { + return InhabitedPredicate::True; + } let pred = tcx.type_of(field.did).instantiate_identity().inhabited_predicate(tcx); if adt.is_enum() { return pred; diff --git a/compiler/rustc_pattern_analysis/src/rustc.rs b/compiler/rustc_pattern_analysis/src/rustc.rs index fec525c9e8c..a25a80cd45f 100644 --- a/compiler/rustc_pattern_analysis/src/rustc.rs +++ b/compiler/rustc_pattern_analysis/src/rustc.rs @@ -15,7 +15,7 @@ use rustc_middle::ty::{ }; use rustc_middle::{bug, span_bug}; use rustc_session::lint; -use rustc_span::{DUMMY_SP, ErrorGuaranteed, Span}; +use rustc_span::{DUMMY_SP, ErrorGuaranteed, Span, sym}; use crate::constructor::Constructor::*; use crate::constructor::{ @@ -230,7 +230,11 @@ impl<'p, 'tcx: 'p> RustcPatCtxt<'p, 'tcx> { let is_visible = adt.is_enum() || field.vis.is_accessible_from(cx.module, cx.tcx); let is_uninhabited = cx.is_uninhabited(*ty); - let skip = is_uninhabited && !is_visible; + let is_unstable = + cx.tcx.lookup_stability(field.did).is_some_and(|stab| { + stab.is_unstable() && stab.feature != sym::rustc_private + }); + let skip = is_uninhabited && (!is_visible || is_unstable); (ty, PrivateUninhabitedField(skip)) }); cx.dropless_arena.alloc_from_iter(tys) diff --git a/tests/ui/uninhabited/auxiliary/staged-api.rs b/tests/ui/uninhabited/auxiliary/staged-api.rs new file mode 100644 index 00000000000..342ecf020ea --- /dev/null +++ b/tests/ui/uninhabited/auxiliary/staged-api.rs @@ -0,0 +1,8 @@ +#![feature(staged_api)] +#![stable(feature = "stable", since = "1.0.0")] + +#[stable(feature = "stable", since = "1.0.0")] +pub struct Foo<T> { + #[unstable(feature = "unstable", issue = "none")] + pub field: T, +} diff --git a/tests/ui/uninhabited/uninhabited-pin-field.rs b/tests/ui/uninhabited/uninhabited-pin-field.rs new file mode 100644 index 00000000000..3d0d9a7a4f8 --- /dev/null +++ b/tests/ui/uninhabited/uninhabited-pin-field.rs @@ -0,0 +1,10 @@ +use std::pin::Pin; + +enum Void {} + +fn demo(x: Pin<Void>) { + match x {} + //~^ ERROR non-exhaustive patterns +} + +fn main() {} diff --git a/tests/ui/uninhabited/uninhabited-pin-field.stderr b/tests/ui/uninhabited/uninhabited-pin-field.stderr new file mode 100644 index 00000000000..93254ca9b98 --- /dev/null +++ b/tests/ui/uninhabited/uninhabited-pin-field.stderr @@ -0,0 +1,19 @@ +error[E0004]: non-exhaustive patterns: type `Pin<Void>` is non-empty + --> $DIR/uninhabited-pin-field.rs:6:11 + | +LL | match x {} + | ^ + | +note: `Pin<Void>` defined here + --> $SRC_DIR/core/src/pin.rs:LL:COL + = note: the matched value is of type `Pin<Void>` +help: ensure that all possible cases are being handled by adding a match arm with a wildcard pattern as shown + | +LL ~ match x { +LL + _ => todo!(), +LL ~ } + | + +error: aborting due to 1 previous error + +For more information about this error, try `rustc --explain E0004`. diff --git a/tests/ui/uninhabited/uninhabited-unstable-field.current.stderr b/tests/ui/uninhabited/uninhabited-unstable-field.current.stderr new file mode 100644 index 00000000000..9e0feb4c473 --- /dev/null +++ b/tests/ui/uninhabited/uninhabited-unstable-field.current.stderr @@ -0,0 +1,22 @@ +error[E0004]: non-exhaustive patterns: type `Foo<Void>` is non-empty + --> $DIR/uninhabited-unstable-field.rs:13:11 + | +LL | match x {} + | ^ + | +note: `Foo<Void>` defined here + --> $DIR/auxiliary/staged-api.rs:5:1 + | +LL | pub struct Foo<T> { + | ^^^^^^^^^^^^^^^^^ + = note: the matched value is of type `Foo<Void>` +help: ensure that all possible cases are being handled by adding a match arm with a wildcard pattern as shown + | +LL ~ match x { +LL + _ => todo!(), +LL ~ } + | + +error: aborting due to 1 previous error + +For more information about this error, try `rustc --explain E0004`. diff --git a/tests/ui/uninhabited/uninhabited-unstable-field.exhaustive.stderr b/tests/ui/uninhabited/uninhabited-unstable-field.exhaustive.stderr new file mode 100644 index 00000000000..9e0feb4c473 --- /dev/null +++ b/tests/ui/uninhabited/uninhabited-unstable-field.exhaustive.stderr @@ -0,0 +1,22 @@ +error[E0004]: non-exhaustive patterns: type `Foo<Void>` is non-empty + --> $DIR/uninhabited-unstable-field.rs:13:11 + | +LL | match x {} + | ^ + | +note: `Foo<Void>` defined here + --> $DIR/auxiliary/staged-api.rs:5:1 + | +LL | pub struct Foo<T> { + | ^^^^^^^^^^^^^^^^^ + = note: the matched value is of type `Foo<Void>` +help: ensure that all possible cases are being handled by adding a match arm with a wildcard pattern as shown + | +LL ~ match x { +LL + _ => todo!(), +LL ~ } + | + +error: aborting due to 1 previous error + +For more information about this error, try `rustc --explain E0004`. diff --git a/tests/ui/uninhabited/uninhabited-unstable-field.rs b/tests/ui/uninhabited/uninhabited-unstable-field.rs new file mode 100644 index 00000000000..9b507c518ab --- /dev/null +++ b/tests/ui/uninhabited/uninhabited-unstable-field.rs @@ -0,0 +1,29 @@ +//@ aux-build: staged-api.rs +//@ revisions: current exhaustive + +#![feature(exhaustive_patterns)] + +extern crate staged_api; + +use staged_api::Foo; + +enum Void {} + +fn demo(x: Foo<Void>) { + match x {} + //~^ ERROR non-exhaustive patterns +} + +// Ensure that the pattern is not considered unreachable. +fn demo2(x: Foo<Void>) { + match x { + Foo { .. } => {} + } +} + +// Same as above, but for wildcard. +fn demo3(x: Foo<Void>) { + match x { _ => {} } +} + +fn main() {} |