diff options
16 files changed, 177 insertions, 13 deletions
diff --git a/compiler/rustc_hir_analysis/src/outlives/utils.rs b/compiler/rustc_hir_analysis/src/outlives/utils.rs index 218f658b061..8077acea52e 100644 --- a/compiler/rustc_hir_analysis/src/outlives/utils.rs +++ b/compiler/rustc_hir_analysis/src/outlives/utils.rs @@ -80,6 +80,10 @@ pub(crate) fn insert_outlives_predicate<'tcx>( .or_insert(span); } + Component::Placeholder(_) => { + span_bug!(span, "Should not deduce placeholder outlives component"); + } + Component::Alias(alias_ty) => { // This would either arise from something like: // diff --git a/compiler/rustc_infer/src/infer/error_reporting/mod.rs b/compiler/rustc_infer/src/infer/error_reporting/mod.rs index 56e3280088e..d7669b1a4b5 100644 --- a/compiler/rustc_infer/src/infer/error_reporting/mod.rs +++ b/compiler/rustc_infer/src/infer/error_reporting/mod.rs @@ -2351,6 +2351,7 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> { let labeled_user_string = match bound_kind { GenericKind::Param(ref p) => format!("the parameter type `{p}`"), + GenericKind::Placeholder(ref p) => format!("the placeholder type `{p:?}`"), GenericKind::Alias(ref p) => match p.kind(self.tcx) { ty::AliasKind::Projection | ty::AliasKind::Inherent => { format!("the associated type `{p}`") diff --git a/compiler/rustc_infer/src/infer/outlives/components.rs b/compiler/rustc_infer/src/infer/outlives/components.rs index f867876a2e6..806ecf35330 100644 --- a/compiler/rustc_infer/src/infer/outlives/components.rs +++ b/compiler/rustc_infer/src/infer/outlives/components.rs @@ -11,6 +11,7 @@ use smallvec::{smallvec, SmallVec}; pub enum Component<'tcx> { Region(ty::Region<'tcx>), Param(ty::ParamTy), + Placeholder(ty::PlaceholderType), UnresolvedInferenceVariable(ty::InferTy), // Projections like `T::Foo` are tricky because a constraint like @@ -120,6 +121,10 @@ fn compute_components<'tcx>( out.push(Component::Param(p)); } + ty::Placeholder(p) => { + out.push(Component::Placeholder(p)); + } + // For projections, we prefer to generate an obligation like // `<P0 as Trait<P1...Pn>>::Foo: 'a`, because this gives the // regionck more ways to prove that it holds. However, @@ -176,7 +181,6 @@ fn compute_components<'tcx>( ty::Tuple(..) | // ... ty::FnPtr(_) | // OutlivesFunction (*) ty::Dynamic(..) | // OutlivesObject, OutlivesFragment (*) - ty::Placeholder(..) | ty::Bound(..) | ty::Error(_) => { // (*) Function pointers and trait objects are both binders. diff --git a/compiler/rustc_infer/src/infer/outlives/obligations.rs b/compiler/rustc_infer/src/infer/outlives/obligations.rs index f36802e1284..1bc24682b9a 100644 --- a/compiler/rustc_infer/src/infer/outlives/obligations.rs +++ b/compiler/rustc_infer/src/infer/outlives/obligations.rs @@ -243,6 +243,9 @@ where Component::Param(param_ty) => { self.param_ty_must_outlive(origin, region, *param_ty); } + Component::Placeholder(placeholder_ty) => { + self.placeholder_ty_must_outlive(origin, region, *placeholder_ty); + } Component::Alias(alias_ty) => self.alias_ty_must_outlive(origin, region, *alias_ty), Component::EscapingAlias(subcomponents) => { self.components_must_outlive(origin, &subcomponents, region, category); @@ -267,11 +270,29 @@ where region: ty::Region<'tcx>, param_ty: ty::ParamTy, ) { - let verify_bound = self.verify_bound.param_bound(param_ty); + let verify_bound = self.verify_bound.param_or_placeholder_bound(param_ty.to_ty(self.tcx)); self.delegate.push_verify(origin, GenericKind::Param(param_ty), region, verify_bound); } #[instrument(level = "debug", skip(self))] + fn placeholder_ty_must_outlive( + &mut self, + origin: infer::SubregionOrigin<'tcx>, + region: ty::Region<'tcx>, + placeholder_ty: ty::PlaceholderType, + ) { + let verify_bound = self + .verify_bound + .param_or_placeholder_bound(Ty::new_placeholder(self.tcx, placeholder_ty)); + self.delegate.push_verify( + origin, + GenericKind::Placeholder(placeholder_ty), + region, + verify_bound, + ); + } + + #[instrument(level = "debug", skip(self))] fn alias_ty_must_outlive( &mut self, origin: infer::SubregionOrigin<'tcx>, diff --git a/compiler/rustc_infer/src/infer/outlives/verify.rs b/compiler/rustc_infer/src/infer/outlives/verify.rs index 7f0a4717d88..35a8fe6dc47 100644 --- a/compiler/rustc_infer/src/infer/outlives/verify.rs +++ b/compiler/rustc_infer/src/infer/outlives/verify.rs @@ -37,11 +37,11 @@ impl<'cx, 'tcx> VerifyBoundCx<'cx, 'tcx> { } #[instrument(level = "debug", skip(self))] - pub fn param_bound(&self, param_ty: ty::ParamTy) -> VerifyBound<'tcx> { + pub fn param_or_placeholder_bound(&self, ty: Ty<'tcx>) -> VerifyBound<'tcx> { // Start with anything like `T: 'a` we can scrape from the // environment. If the environment contains something like // `for<'a> T: 'a`, then we know that `T` outlives everything. - let declared_bounds_from_env = self.declared_generic_bounds_from_env(param_ty); + let declared_bounds_from_env = self.declared_generic_bounds_from_env(ty); debug!(?declared_bounds_from_env); let mut param_bounds = vec![]; for declared_bound in declared_bounds_from_env { @@ -51,7 +51,7 @@ impl<'cx, 'tcx> VerifyBoundCx<'cx, 'tcx> { param_bounds.push(VerifyBound::OutlivedBy(region)); } else { // This is `for<'a> T: 'a`. This means that `T` outlives everything! All done here. - debug!("found that {param_ty:?} outlives any lifetime, returning empty vector"); + debug!("found that {ty:?} outlives any lifetime, returning empty vector"); return VerifyBound::AllBounds(vec![]); } } @@ -168,7 +168,10 @@ impl<'cx, 'tcx> VerifyBoundCx<'cx, 'tcx> { ) -> VerifyBound<'tcx> { match *component { Component::Region(lt) => VerifyBound::OutlivedBy(lt), - Component::Param(param_ty) => self.param_bound(param_ty), + Component::Param(param_ty) => self.param_or_placeholder_bound(param_ty.to_ty(self.tcx)), + Component::Placeholder(placeholder_ty) => { + self.param_or_placeholder_bound(Ty::new_placeholder(self.tcx, placeholder_ty)) + } Component::Alias(alias_ty) => self.alias_bound(alias_ty, visited), Component::EscapingAlias(ref components) => { self.bound_from_components(components, visited) @@ -195,9 +198,9 @@ impl<'cx, 'tcx> VerifyBoundCx<'cx, 'tcx> { /// bounds, but all the bounds it returns can be relied upon. fn declared_generic_bounds_from_env( &self, - param_ty: ty::ParamTy, + generic_ty: Ty<'tcx>, ) -> Vec<ty::Binder<'tcx, ty::OutlivesPredicate<Ty<'tcx>, ty::Region<'tcx>>>> { - let generic_ty = param_ty.to_ty(self.tcx); + assert!(matches!(generic_ty.kind(), ty::Param(_) | ty::Placeholder(_))); self.declared_generic_bounds_from_env_for_erased_ty(generic_ty) } diff --git a/compiler/rustc_infer/src/infer/region_constraints/mod.rs b/compiler/rustc_infer/src/infer/region_constraints/mod.rs index e888340bde3..eb00621ed7f 100644 --- a/compiler/rustc_infer/src/infer/region_constraints/mod.rs +++ b/compiler/rustc_infer/src/infer/region_constraints/mod.rs @@ -147,6 +147,7 @@ pub struct Verify<'tcx> { #[derive(Copy, Clone, PartialEq, Eq, Hash, TypeFoldable, TypeVisitable)] pub enum GenericKind<'tcx> { Param(ty::ParamTy), + Placeholder(ty::PlaceholderType), Alias(ty::AliasTy<'tcx>), } @@ -707,6 +708,7 @@ impl<'tcx> fmt::Debug for GenericKind<'tcx> { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { match *self { GenericKind::Param(ref p) => write!(f, "{p:?}"), + GenericKind::Placeholder(ref p) => write!(f, "{p:?}"), GenericKind::Alias(ref p) => write!(f, "{p:?}"), } } @@ -716,6 +718,7 @@ impl<'tcx> fmt::Display for GenericKind<'tcx> { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { match *self { GenericKind::Param(ref p) => write!(f, "{p}"), + GenericKind::Placeholder(ref p) => write!(f, "{p:?}"), GenericKind::Alias(ref p) => write!(f, "{p}"), } } @@ -725,6 +728,7 @@ impl<'tcx> GenericKind<'tcx> { pub fn to_ty(&self, tcx: TyCtxt<'tcx>) -> Ty<'tcx> { match *self { GenericKind::Param(ref p) => p.to_ty(tcx), + GenericKind::Placeholder(ref p) => Ty::new_placeholder(tcx, *p), GenericKind::Alias(ref p) => p.to_ty(tcx), } } diff --git a/compiler/rustc_infer/src/traits/util.rs b/compiler/rustc_infer/src/traits/util.rs index 8cee13ce4ec..ed3409149d0 100644 --- a/compiler/rustc_infer/src/traits/util.rs +++ b/compiler/rustc_infer/src/traits/util.rs @@ -365,6 +365,11 @@ impl<'tcx, O: Elaboratable<'tcx>> Elaborator<'tcx, O> { Some(ty::ClauseKind::TypeOutlives(ty::OutlivesPredicate(ty, r_min))) } + Component::Placeholder(p) => { + let ty = Ty::new_placeholder(tcx, p); + Some(ty::ClauseKind::TypeOutlives(ty::OutlivesPredicate(ty, r_min))) + } + Component::UnresolvedInferenceVariable(_) => None, Component::Alias(alias_ty) => { diff --git a/compiler/rustc_trait_selection/src/traits/coherence.rs b/compiler/rustc_trait_selection/src/traits/coherence.rs index 7ca33ae41c0..f72a5e66ad7 100644 --- a/compiler/rustc_trait_selection/src/traits/coherence.rs +++ b/compiler/rustc_trait_selection/src/traits/coherence.rs @@ -398,7 +398,8 @@ fn impl_intersection_has_negative_obligation( debug!("negative_impl(impl1_def_id={:?}, impl2_def_id={:?})", impl1_def_id, impl2_def_id); let ref infcx = tcx.infer_ctxt().intercrate(true).with_next_trait_solver(true).build(); - let universe = infcx.universe(); + let root_universe = infcx.universe(); + assert_eq!(root_universe, ty::UniverseIndex::ROOT); let impl1_header = fresh_impl_header(infcx, impl1_def_id); let param_env = @@ -414,7 +415,12 @@ fn impl_intersection_has_negative_obligation( return false; }; - plug_infer_with_placeholders(infcx, universe, (impl1_header.impl_args, impl2_header.impl_args)); + plug_infer_with_placeholders( + infcx, + root_universe, + (impl1_header.impl_args, impl2_header.impl_args), + ); + let param_env = infcx.resolve_vars_if_possible(param_env); util::elaborate(tcx, tcx.predicates_of(impl2_def_id).instantiate(tcx, impl2_header.impl_args)) .any(|(clause, _)| try_prove_negated_where_clause(infcx, clause, param_env)) diff --git a/compiler/rustc_trait_selection/src/traits/query/type_op/implied_outlives_bounds.rs b/compiler/rustc_trait_selection/src/traits/query/type_op/implied_outlives_bounds.rs index e345fc39ead..57df277f4b3 100644 --- a/compiler/rustc_trait_selection/src/traits/query/type_op/implied_outlives_bounds.rs +++ b/compiler/rustc_trait_selection/src/traits/query/type_op/implied_outlives_bounds.rs @@ -208,6 +208,9 @@ fn implied_bounds_from_components<'tcx>( Component::Region(r) => Some(OutlivesBound::RegionSubRegion(sub_region, r)), Component::Param(p) => Some(OutlivesBound::RegionSubParam(sub_region, p)), Component::Alias(p) => Some(OutlivesBound::RegionSubAlias(sub_region, p)), + Component::Placeholder(_) => { + unimplemented!("Shouldn't expect a placeholder type in implied bounds (yet)") + } Component::EscapingAlias(_) => // If the projection has escaping regions, don't // try to infer any implied bounds even for its diff --git a/tests/ui/coherence/negative-coherence-check-placeholder-outlives.rs b/tests/ui/coherence/negative-coherence-check-placeholder-outlives.rs new file mode 100644 index 00000000000..5d8beb45132 --- /dev/null +++ b/tests/ui/coherence/negative-coherence-check-placeholder-outlives.rs @@ -0,0 +1,14 @@ +#![feature(negative_impls)] +#![feature(with_negative_coherence)] + +struct Wrap<T>(T); + +trait Foo {} +impl<T: 'static> !Foo for Box<T> {} + +trait Bar {} +impl<T> Bar for T where T: Foo {} +impl<T> Bar for Box<T> {} +//~^ ERROR conflicting implementations of trait `Bar` for type `Box<_>` + +fn main() {} diff --git a/tests/ui/coherence/negative-coherence-check-placeholder-outlives.stderr b/tests/ui/coherence/negative-coherence-check-placeholder-outlives.stderr new file mode 100644 index 00000000000..52d36c92f99 --- /dev/null +++ b/tests/ui/coherence/negative-coherence-check-placeholder-outlives.stderr @@ -0,0 +1,11 @@ +error[E0119]: conflicting implementations of trait `Bar` for type `Box<_>` + --> $DIR/negative-coherence-check-placeholder-outlives.rs:11:1 + | +LL | impl<T> Bar for T where T: Foo {} + | ------------------------------ first implementation here +LL | impl<T> Bar for Box<T> {} + | ^^^^^^^^^^^^^^^^^^^^^^ conflicting implementation for `Box<_>` + +error: aborting due to previous error + +For more information about this error, try `rustc --explain E0119`. diff --git a/tests/ui/traits/non_lifetime_binders/placeholders-dont-outlive-static.bad.stderr b/tests/ui/traits/non_lifetime_binders/placeholders-dont-outlive-static.bad.stderr new file mode 100644 index 00000000000..e6c36129b28 --- /dev/null +++ b/tests/ui/traits/non_lifetime_binders/placeholders-dont-outlive-static.bad.stderr @@ -0,0 +1,26 @@ +warning: the feature `non_lifetime_binders` is incomplete and may not be safe to use and/or cause compiler crashes + --> $DIR/placeholders-dont-outlive-static.rs:6:12 + | +LL | #![feature(non_lifetime_binders)] + | ^^^^^^^^^^^^^^^^^^^^ + | + = note: see issue #108185 <https://github.com/rust-lang/rust/issues/108185> for more information + = note: `#[warn(incomplete_features)]` on by default + +error[E0310]: the placeholder type `!1_"T"` may not live long enough + --> $DIR/placeholders-dont-outlive-static.rs:13:5 + | +LL | foo(); + | ^^^^^ + | | + | the placeholder type `!1_"T"` must be valid for the static lifetime... + | ...so that the type `T` will meet its required lifetime bounds + | +help: consider adding an explicit lifetime bound + | +LL | fn bad() where !1_"T": 'static { + | +++++++++++++++++++++ + +error: aborting due to previous error; 1 warning emitted + +For more information about this error, try `rustc --explain E0310`. diff --git a/tests/ui/traits/non_lifetime_binders/placeholders-dont-outlive-static.good.stderr b/tests/ui/traits/non_lifetime_binders/placeholders-dont-outlive-static.good.stderr new file mode 100644 index 00000000000..31441ef4db8 --- /dev/null +++ b/tests/ui/traits/non_lifetime_binders/placeholders-dont-outlive-static.good.stderr @@ -0,0 +1,26 @@ +warning: the feature `non_lifetime_binders` is incomplete and may not be safe to use and/or cause compiler crashes + --> $DIR/placeholders-dont-outlive-static.rs:6:12 + | +LL | #![feature(non_lifetime_binders)] + | ^^^^^^^^^^^^^^^^^^^^ + | + = note: see issue #108185 <https://github.com/rust-lang/rust/issues/108185> for more information + = note: `#[warn(incomplete_features)]` on by default + +error[E0310]: the placeholder type `!1_"T"` may not live long enough + --> $DIR/placeholders-dont-outlive-static.rs:19:5 + | +LL | foo(); + | ^^^^^ + | | + | the placeholder type `!1_"T"` must be valid for the static lifetime... + | ...so that the type `T` will meet its required lifetime bounds + | +help: consider adding an explicit lifetime bound + | +LL | fn good() where for<T> T: 'static, !1_"T": 'static { + | +++++++++++++++++ + +error: aborting due to previous error; 1 warning emitted + +For more information about this error, try `rustc --explain E0310`. diff --git a/tests/ui/traits/non_lifetime_binders/placeholders-dont-outlive-static.rs b/tests/ui/traits/non_lifetime_binders/placeholders-dont-outlive-static.rs new file mode 100644 index 00000000000..ae6866511e2 --- /dev/null +++ b/tests/ui/traits/non_lifetime_binders/placeholders-dont-outlive-static.rs @@ -0,0 +1,22 @@ +// revisions: good bad + +//[good] known-bug: unknown +// `for<T> T: 'static` doesn't imply itself when processing outlives obligations + +#![feature(non_lifetime_binders)] +//[bad]~^ WARN the feature `non_lifetime_binders` is incomplete + +fn foo() where for<T> T: 'static {} + +#[cfg(bad)] +fn bad() { + foo(); + //[bad]~^ ERROR the placeholder type `!1_"T"` may not live long enough +} + +#[cfg(good)] +fn good() where for<T> T: 'static { + foo(); +} + +fn main() {} diff --git a/tests/ui/traits/non_lifetime_binders/type-match-with-late-bound.rs b/tests/ui/traits/non_lifetime_binders/type-match-with-late-bound.rs index 5ff7089b993..53957914e3a 100644 --- a/tests/ui/traits/non_lifetime_binders/type-match-with-late-bound.rs +++ b/tests/ui/traits/non_lifetime_binders/type-match-with-late-bound.rs @@ -1,10 +1,9 @@ // edition:2021 -// check-pass +// known-bug: unknown // Checks that test_type_match code doesn't ICE when predicates have late-bound types #![feature(non_lifetime_binders)] -//~^ WARN is incomplete and may not be safe to use async fn walk2<'a, T: 'a>(_: T) where diff --git a/tests/ui/traits/non_lifetime_binders/type-match-with-late-bound.stderr b/tests/ui/traits/non_lifetime_binders/type-match-with-late-bound.stderr index 3609bed28df..ddb6a798711 100644 --- a/tests/ui/traits/non_lifetime_binders/type-match-with-late-bound.stderr +++ b/tests/ui/traits/non_lifetime_binders/type-match-with-late-bound.stderr @@ -7,5 +7,20 @@ LL | #![feature(non_lifetime_binders)] = note: see issue #108185 <https://github.com/rust-lang/rust/issues/108185> for more information = note: `#[warn(incomplete_features)]` on by default -warning: 1 warning emitted +error[E0309]: the placeholder type `!1_"F"` may not live long enough + --> $DIR/type-match-with-late-bound.rs:11:1 + | +LL | async fn walk2<'a, T: 'a>(_: T) + | -- the placeholder type `!1_"F"` must be valid for the lifetime `'a` as defined here... +... +LL | {} + | ^^ ...so that the type `F` will meet its required lifetime bounds + | +help: consider adding an explicit lifetime bound + | +LL | for<F> F: 'a, !1_"F": 'a + | ~~~~~~~~~~~~ + +error: aborting due to previous error; 1 warning emitted +For more information about this error, try `rustc --explain E0309`. |