diff options
| -rw-r--r-- | compiler/rustc_hir_analysis/src/check/wfcheck.rs | 60 | ||||
| -rw-r--r-- | tests/ui/impl-trait/in-trait/gat-outlives.rs | 17 | ||||
| -rw-r--r-- | tests/ui/impl-trait/in-trait/gat-outlives.stderr | 24 |
3 files changed, 68 insertions, 33 deletions
diff --git a/compiler/rustc_hir_analysis/src/check/wfcheck.rs b/compiler/rustc_hir_analysis/src/check/wfcheck.rs index 97ebd42d077..34c28bce5d8 100644 --- a/compiler/rustc_hir_analysis/src/check/wfcheck.rs +++ b/compiler/rustc_hir_analysis/src/check/wfcheck.rs @@ -314,9 +314,10 @@ fn check_trait_item(tcx: TyCtxt<'_>, trait_item: &hir::TraitItem<'_>) { /// fn into_iter<'a>(&'a self) -> Self::Iter<'a>; /// } /// ``` -fn check_gat_where_clauses(tcx: TyCtxt<'_>, associated_items: &[hir::TraitItemRef]) { +fn check_gat_where_clauses(tcx: TyCtxt<'_>, trait_def_id: LocalDefId) { // Associates every GAT's def_id to a list of possibly missing bounds detected by this lint. let mut required_bounds_by_item = FxHashMap::default(); + let associated_items = tcx.associated_items(trait_def_id); // Loop over all GATs together, because if this lint suggests adding a where-clause bound // to one GAT, it might then require us to an additional bound on another GAT. @@ -325,8 +326,8 @@ fn check_gat_where_clauses(tcx: TyCtxt<'_>, associated_items: &[hir::TraitItemRe // those GATs. loop { let mut should_continue = false; - for gat_item in associated_items { - let gat_def_id = gat_item.id.owner_id; + for gat_item in associated_items.in_definition_order() { + let gat_def_id = gat_item.def_id.expect_local(); let gat_item = tcx.associated_item(gat_def_id); // If this item is not an assoc ty, or has no args, then it's not a GAT if gat_item.kind != ty::AssocKind::Type { @@ -342,8 +343,8 @@ fn check_gat_where_clauses(tcx: TyCtxt<'_>, associated_items: &[hir::TraitItemRe // This is calculated by taking the intersection of the bounds that each item // constrains the GAT with individually. let mut new_required_bounds: Option<FxHashSet<ty::Clause<'_>>> = None; - for item in associated_items { - let item_def_id = item.id.owner_id; + for item in associated_items.in_definition_order() { + let item_def_id = item.def_id.expect_local(); // Skip our own GAT, since it does not constrain itself at all. if item_def_id == gat_def_id { continue; @@ -351,9 +352,9 @@ fn check_gat_where_clauses(tcx: TyCtxt<'_>, associated_items: &[hir::TraitItemRe let param_env = tcx.param_env(item_def_id); - let item_required_bounds = match item.kind { + let item_required_bounds = match tcx.associated_item(item_def_id).kind { // In our example, this corresponds to `into_iter` method - hir::AssocItemKind::Fn { .. } => { + ty::AssocKind::Fn => { // For methods, we check the function signature's return type for any GATs // to constrain. In the `into_iter` case, we see that the return type // `Self::Iter<'a>` is a GAT we want to gather any potential missing bounds from. @@ -369,12 +370,12 @@ fn check_gat_where_clauses(tcx: TyCtxt<'_>, associated_items: &[hir::TraitItemRe // We also assume that all of the function signature's parameter types // are well formed. &sig.inputs().iter().copied().collect(), - gat_def_id.def_id, + gat_def_id, gat_generics, ) } // In our example, this corresponds to the `Iter` and `Item` associated types - hir::AssocItemKind::Type => { + ty::AssocKind::Type => { // If our associated item is a GAT with missing bounds, add them to // the param-env here. This allows this GAT to propagate missing bounds // to other GATs. @@ -391,11 +392,11 @@ fn check_gat_where_clauses(tcx: TyCtxt<'_>, associated_items: &[hir::TraitItemRe .instantiate_identity_iter_copied() .collect::<Vec<_>>(), &FxIndexSet::default(), - gat_def_id.def_id, + gat_def_id, gat_generics, ) } - hir::AssocItemKind::Const => None, + ty::AssocKind::Const => None, }; if let Some(item_required_bounds) = item_required_bounds { @@ -431,7 +432,12 @@ fn check_gat_where_clauses(tcx: TyCtxt<'_>, associated_items: &[hir::TraitItemRe } for (gat_def_id, required_bounds) in required_bounds_by_item { - let gat_item_hir = tcx.hir().expect_trait_item(gat_def_id.def_id); + // Don't suggest adding `Self: 'a` to a GAT that can't be named + if tcx.is_impl_trait_in_trait(gat_def_id.to_def_id()) { + continue; + } + + let gat_item_hir = tcx.hir().expect_trait_item(gat_def_id); debug!(?required_bounds); let param_env = tcx.param_env(gat_def_id); @@ -441,21 +447,16 @@ fn check_gat_where_clauses(tcx: TyCtxt<'_>, associated_items: &[hir::TraitItemRe ty::ClauseKind::RegionOutlives(ty::OutlivesPredicate(a, b)) => { !region_known_to_outlive( tcx, - gat_def_id.def_id, + gat_def_id, param_env, &FxIndexSet::default(), a, b, ) } - ty::ClauseKind::TypeOutlives(ty::OutlivesPredicate(a, b)) => !ty_known_to_outlive( - tcx, - gat_def_id.def_id, - param_env, - &FxIndexSet::default(), - a, - b, - ), + ty::ClauseKind::TypeOutlives(ty::OutlivesPredicate(a, b)) => { + !ty_known_to_outlive(tcx, gat_def_id, param_env, &FxIndexSet::default(), a, b) + } _ => bug!("Unexpected ClauseKind"), }) .map(|clause| clause.to_string()) @@ -534,7 +535,7 @@ fn augment_param_env<'tcx>( fn gather_gat_bounds<'tcx, T: TypeFoldable<TyCtxt<'tcx>>>( tcx: TyCtxt<'tcx>, param_env: ty::ParamEnv<'tcx>, - item_def_id: hir::OwnerId, + item_def_id: LocalDefId, to_check: T, wf_tys: &FxIndexSet<Ty<'tcx>>, gat_def_id: LocalDefId, @@ -567,7 +568,7 @@ fn gather_gat_bounds<'tcx, T: TypeFoldable<TyCtxt<'tcx>>>( // reflected in a where clause on the GAT itself. for (ty, ty_idx) in &types { // In our example, requires that `Self: 'a` - if ty_known_to_outlive(tcx, item_def_id.def_id, param_env, &wf_tys, *ty, *region_a) { + if ty_known_to_outlive(tcx, item_def_id, param_env, &wf_tys, *ty, *region_a) { debug!(?ty_idx, ?region_a_idx); debug!("required clause: {ty} must outlive {region_a}"); // Translate into the generic parameters of the GAT. In @@ -606,14 +607,7 @@ fn gather_gat_bounds<'tcx, T: TypeFoldable<TyCtxt<'tcx>>>( if matches!(**region_b, ty::ReStatic | ty::ReError(_)) || region_a == region_b { continue; } - if region_known_to_outlive( - tcx, - item_def_id.def_id, - param_env, - &wf_tys, - *region_a, - *region_b, - ) { + if region_known_to_outlive(tcx, item_def_id, param_env, &wf_tys, *region_a, *region_b) { debug!(?region_a_idx, ?region_b_idx); debug!("required clause: {region_a} must outlive {region_b}"); // Translate into the generic parameters of the GAT. @@ -1114,8 +1108,8 @@ fn check_trait(tcx: TyCtxt<'_>, item: &hir::Item<'_>) { }); // Only check traits, don't check trait aliases - if let hir::ItemKind::Trait(_, _, _, _, items) = item.kind { - check_gat_where_clauses(tcx, items); + if let hir::ItemKind::Trait(..) = item.kind { + check_gat_where_clauses(tcx, item.owner_id.def_id); } } diff --git a/tests/ui/impl-trait/in-trait/gat-outlives.rs b/tests/ui/impl-trait/in-trait/gat-outlives.rs new file mode 100644 index 00000000000..83dd6cfce53 --- /dev/null +++ b/tests/ui/impl-trait/in-trait/gat-outlives.rs @@ -0,0 +1,17 @@ +// edition: 2021 + +use std::future::Future; + +trait Trait { + type Gat<'a>; + //~^ ERROR missing required bound on `Gat` + async fn foo(&self) -> Self::Gat<'_>; +} + +trait Trait2 { + type Gat<'a>; + //~^ ERROR missing required bound on `Gat` + async fn foo(&self) -> impl Future<Output = Self::Gat<'_>>; +} + +fn main() {} diff --git a/tests/ui/impl-trait/in-trait/gat-outlives.stderr b/tests/ui/impl-trait/in-trait/gat-outlives.stderr new file mode 100644 index 00000000000..8ec4b0ab2ee --- /dev/null +++ b/tests/ui/impl-trait/in-trait/gat-outlives.stderr @@ -0,0 +1,24 @@ +error: missing required bound on `Gat` + --> $DIR/gat-outlives.rs:6:5 + | +LL | type Gat<'a>; + | ^^^^^^^^^^^^- + | | + | help: add the required where clause: `where Self: 'a` + | + = note: this bound is currently required to ensure that impls have maximum flexibility + = note: we are soliciting feedback, see issue #87479 <https://github.com/rust-lang/rust/issues/87479> for more information + +error: missing required bound on `Gat` + --> $DIR/gat-outlives.rs:12:5 + | +LL | type Gat<'a>; + | ^^^^^^^^^^^^- + | | + | help: add the required where clause: `where Self: 'a` + | + = note: this bound is currently required to ensure that impls have maximum flexibility + = note: we are soliciting feedback, see issue #87479 <https://github.com/rust-lang/rust/issues/87479> for more information + +error: aborting due to 2 previous errors + |