diff options
9 files changed, 73 insertions, 81 deletions
diff --git a/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/cfg_build.rs b/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/cfg_build.rs index 122ad7009cb..a78b294181c 100644 --- a/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/cfg_build.rs +++ b/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/cfg_build.rs @@ -217,7 +217,7 @@ impl<'a, 'tcx> DropRangeVisitor<'a, 'tcx> { let ty = self.tcx.erase_regions(ty); let m = self.tcx.parent_module(expr.hir_id).to_def_id(); let param_env = self.tcx.param_env(m.expect_local()); - if self.tcx.is_ty_uninhabited_from(m, ty, param_env) { + if !ty.is_inhabited_from(self.tcx, m, param_env) { // This function will not return. We model this fact as an infinite loop. self.drop_ranges.add_control_edge(self.expr_index + 1, self.expr_index + 1); } diff --git a/compiler/rustc_hir_typeck/src/generator_interior/mod.rs b/compiler/rustc_hir_typeck/src/generator_interior/mod.rs index 7bbfb70f2c3..bd3589c6c43 100644 --- a/compiler/rustc_hir_typeck/src/generator_interior/mod.rs +++ b/compiler/rustc_hir_typeck/src/generator_interior/mod.rs @@ -542,10 +542,10 @@ fn check_must_not_suspend_ty<'tcx>( data: SuspendCheckData<'_, 'tcx>, ) -> bool { if ty.is_unit() - // FIXME: should this check `is_ty_uninhabited_from`. This query is not available in this stage + // FIXME: should this check `Ty::is_inhabited_from`. This query is not available in this stage // of typeck (before ReVar and RePlaceholder are removed), but may remove noise, like in // `must_use` - // || fcx.tcx.is_ty_uninhabited_from(fcx.tcx.parent_module(hir_id).to_def_id(), ty, fcx.param_env) + // || !ty.is_inhabited_from(fcx.tcx, fcx.tcx.parent_module(hir_id).to_def_id(), fcx.param_env) { return false; } diff --git a/compiler/rustc_lint/src/unused.rs b/compiler/rustc_lint/src/unused.rs index cdf279313a6..100a8788763 100644 --- a/compiler/rustc_lint/src/unused.rs +++ b/compiler/rustc_lint/src/unused.rs @@ -201,9 +201,9 @@ impl<'tcx> LateLintPass<'tcx> for UnusedResults { plural_len: usize, ) -> bool { if ty.is_unit() - || cx.tcx.is_ty_uninhabited_from( + || !ty.is_inhabited_from( + cx.tcx, cx.tcx.parent_module(expr.hir_id).to_def_id(), - ty, cx.param_env, ) { diff --git a/compiler/rustc_middle/src/ty/inhabitedness/mod.rs b/compiler/rustc_middle/src/ty/inhabitedness/mod.rs index 305c8190c4c..ce9ec5c2b69 100644 --- a/compiler/rustc_middle/src/ty/inhabitedness/mod.rs +++ b/compiler/rustc_middle/src/ty/inhabitedness/mod.rs @@ -57,57 +57,6 @@ pub(crate) fn provide(providers: &mut ty::query::Providers) { ty::query::Providers { inhabited_predicate_adt, inhabited_predicate_type, ..*providers }; } -impl<'tcx> TyCtxt<'tcx> { - /// Checks whether a type is visibly uninhabited from a particular module. - /// - /// # Example - /// ``` - /// #![feature(never_type)] - /// # fn main() {} - /// enum Void {} - /// mod a { - /// pub mod b { - /// pub struct SecretlyUninhabited { - /// _priv: !, - /// } - /// } - /// } - /// - /// mod c { - /// use super::Void; - /// pub struct AlsoSecretlyUninhabited { - /// _priv: Void, - /// } - /// mod d { - /// } - /// } - /// - /// struct Foo { - /// x: a::b::SecretlyUninhabited, - /// y: c::AlsoSecretlyUninhabited, - /// } - /// ``` - /// In this code, the type `Foo` will only be visibly uninhabited inside the - /// modules b, c and d. This effects pattern-matching on `Foo` or types that - /// contain `Foo`. - /// - /// # Example - /// ```ignore (illustrative) - /// let foo_result: Result<T, Foo> = ... ; - /// let Ok(t) = foo_result; - /// ``` - /// This code should only compile in modules where the uninhabitedness of Foo is - /// visible. - pub fn is_ty_uninhabited_from( - self, - module: DefId, - ty: Ty<'tcx>, - param_env: ty::ParamEnv<'tcx>, - ) -> bool { - !ty.inhabited_predicate(self).apply(self, param_env, module) - } -} - /// Returns an `InhabitedPredicate` that is generic over type parameters and /// requires calling [`InhabitedPredicate::subst`] fn inhabited_predicate_adt(tcx: TyCtxt<'_>, def_id: DefId) -> InhabitedPredicate<'_> { @@ -171,6 +120,55 @@ impl<'tcx> Ty<'tcx> { _ => InhabitedPredicate::True, } } + + /// Checks whether a type is visibly uninhabited from a particular module. + /// + /// # Example + /// ``` + /// #![feature(never_type)] + /// # fn main() {} + /// enum Void {} + /// mod a { + /// pub mod b { + /// pub struct SecretlyUninhabited { + /// _priv: !, + /// } + /// } + /// } + /// + /// mod c { + /// use super::Void; + /// pub struct AlsoSecretlyUninhabited { + /// _priv: Void, + /// } + /// mod d { + /// } + /// } + /// + /// struct Foo { + /// x: a::b::SecretlyUninhabited, + /// y: c::AlsoSecretlyUninhabited, + /// } + /// ``` + /// In this code, the type `Foo` will only be visibly uninhabited inside the + /// modules b, c and d. This effects pattern-matching on `Foo` or types that + /// contain `Foo`. + /// + /// # Example + /// ```ignore (illustrative) + /// let foo_result: Result<T, Foo> = ... ; + /// let Ok(t) = foo_result; + /// ``` + /// This code should only compile in modules where the uninhabitedness of Foo is + /// visible. + pub fn is_inhabited_from( + self, + tcx: TyCtxt<'tcx>, + module: DefId, + param_env: ty::ParamEnv<'tcx>, + ) -> bool { + self.inhabited_predicate(tcx).apply(tcx, param_env, module) + } } /// N.B. this query should only be called through `Ty::inhabited_predicate` diff --git a/compiler/rustc_mir_build/src/build/expr/into.rs b/compiler/rustc_mir_build/src/build/expr/into.rs index 24ecd0a5399..efb6eba7e57 100644 --- a/compiler/rustc_mir_build/src/build/expr/into.rs +++ b/compiler/rustc_mir_build/src/build/expr/into.rs @@ -271,15 +271,10 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { // MIR checks and ultimately whether code is accepted or not. We can only // omit the return edge if a return type is visibly uninhabited to a module // that makes the call. - target: if this.tcx.is_ty_uninhabited_from( - this.parent_module, - expr.ty, - this.param_env, - ) { - None - } else { - Some(success) - }, + target: expr + .ty + .is_inhabited_from(this.tcx, this.parent_module, this.param_env) + .then_some(success), from_hir_call, fn_span, }, diff --git a/compiler/rustc_mir_build/src/thir/pattern/check_match.rs b/compiler/rustc_mir_build/src/thir/pattern/check_match.rs index 93a3dd8962a..0df228a0d59 100644 --- a/compiler/rustc_mir_build/src/thir/pattern/check_match.rs +++ b/compiler/rustc_mir_build/src/thir/pattern/check_match.rs @@ -818,7 +818,7 @@ fn non_exhaustive_match<'p, 'tcx>( } } if let ty::Ref(_, sub_ty, _) = scrut_ty.kind() { - if cx.tcx.is_ty_uninhabited_from(cx.module, *sub_ty, cx.param_env) { + if !sub_ty.is_inhabited_from(cx.tcx, cx.module, cx.param_env) { err.note("references are always considered inhabited"); } } diff --git a/compiler/rustc_mir_build/src/thir/pattern/usefulness.rs b/compiler/rustc_mir_build/src/thir/pattern/usefulness.rs index 8dc9976eaea..3e370a05376 100644 --- a/compiler/rustc_mir_build/src/thir/pattern/usefulness.rs +++ b/compiler/rustc_mir_build/src/thir/pattern/usefulness.rs @@ -324,7 +324,7 @@ pub(crate) struct MatchCheckCtxt<'p, 'tcx> { impl<'a, 'tcx> MatchCheckCtxt<'a, 'tcx> { pub(super) fn is_uninhabited(&self, ty: Ty<'tcx>) -> bool { if self.tcx.features().exhaustive_patterns { - self.tcx.is_ty_uninhabited_from(self.module, ty, self.param_env) + !ty.is_inhabited_from(self.tcx, self.module, self.param_env) } else { false } diff --git a/compiler/rustc_passes/src/liveness.rs b/compiler/rustc_passes/src/liveness.rs index 0100860afb9..58e1fe937a6 100644 --- a/compiler/rustc_passes/src/liveness.rs +++ b/compiler/rustc_passes/src/liveness.rs @@ -1284,20 +1284,19 @@ impl<'a, 'tcx> Liveness<'a, 'tcx> { fn check_is_ty_uninhabited(&mut self, expr: &Expr<'_>, succ: LiveNode) -> LiveNode { let ty = self.typeck_results.expr_ty(expr); let m = self.ir.tcx.parent_module(expr.hir_id).to_def_id(); - if self.ir.tcx.is_ty_uninhabited_from(m, ty, self.param_env) { - match self.ir.lnks[succ] { - LiveNodeKind::ExprNode(succ_span, succ_id) => { - self.warn_about_unreachable(expr.span, ty, succ_span, succ_id, "expression"); - } - LiveNodeKind::VarDefNode(succ_span, succ_id) => { - self.warn_about_unreachable(expr.span, ty, succ_span, succ_id, "definition"); - } - _ => {} - }; - self.exit_ln - } else { - succ + if ty.is_inhabited_from(self.ir.tcx, m, self.param_env) { + return succ; } + match self.ir.lnks[succ] { + LiveNodeKind::ExprNode(succ_span, succ_id) => { + self.warn_about_unreachable(expr.span, ty, succ_span, succ_id, "expression"); + } + LiveNodeKind::VarDefNode(succ_span, succ_id) => { + self.warn_about_unreachable(expr.span, ty, succ_span, succ_id, "definition"); + } + _ => {} + }; + self.exit_ln } fn warn_about_unreachable( diff --git a/src/test/ui/pattern/usefulness/uninhabited.rs b/src/test/ui/pattern/usefulness/uninhabited.rs index 77cd0f4005e..5622808d4c7 100644 --- a/src/test/ui/pattern/usefulness/uninhabited.rs +++ b/src/test/ui/pattern/usefulness/uninhabited.rs @@ -2,7 +2,7 @@ // aux-build:empty.rs // // This tests plays with matching and uninhabited types. This also serves as a test for the -// `tcx.is_ty_uninhabited_from()` function. +// `Ty::is_inhabited_from` function. #![feature(never_type)] #![feature(never_type_fallback)] #![feature(exhaustive_patterns)] |