diff options
Diffstat (limited to 'compiler/rustc_trait_selection/src')
3 files changed, 162 insertions, 44 deletions
diff --git a/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs b/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs index 2ce1b955af5..1cee82f04ea 100644 --- a/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs +++ b/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs @@ -5,10 +5,11 @@ use rustc_data_structures::fx::FxHashMap; use rustc_data_structures::unord::UnordSet; use rustc_errors::codes::*; use rustc_errors::{ - pluralize, struct_span_code_err, Applicability, Diag, ErrorGuaranteed, StashKey, StringPart, + pluralize, struct_span_code_err, Applicability, Diag, ErrorGuaranteed, MultiSpan, StashKey, + StringPart, }; use rustc_hir::def::Namespace; -use rustc_hir::def_id::{DefId, LocalDefId}; +use rustc_hir::def_id::{DefId, LocalDefId, LOCAL_CRATE}; use rustc_hir::intravisit::Visitor; use rustc_hir::{self as hir, LangItem, Node}; use rustc_infer::infer::{InferOk, TypeTrace}; @@ -1624,9 +1625,131 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> { other: bool, param_env: ty::ParamEnv<'tcx>, ) -> bool { - // If we have a single implementation, try to unify it with the trait ref - // that failed. This should uncover a better hint for what *is* implemented. + let alternative_candidates = |def_id: DefId| { + let mut impl_candidates: Vec<_> = self + .tcx + .all_impls(def_id) + // ignore `do_not_recommend` items + .filter(|def_id| { + !self + .tcx + .has_attrs_with_path(*def_id, &[sym::diagnostic, sym::do_not_recommend]) + }) + // Ignore automatically derived impls and `!Trait` impls. + .filter_map(|def_id| self.tcx.impl_trait_header(def_id)) + .filter_map(|header| { + (header.polarity != ty::ImplPolarity::Negative + || self.tcx.is_automatically_derived(def_id)) + .then(|| header.trait_ref.instantiate_identity()) + }) + .filter(|trait_ref| { + let self_ty = trait_ref.self_ty(); + // Avoid mentioning type parameters. + if let ty::Param(_) = self_ty.kind() { + false + } + // Avoid mentioning types that are private to another crate + else if let ty::Adt(def, _) = self_ty.peel_refs().kind() { + // FIXME(compiler-errors): This could be generalized, both to + // be more granular, and probably look past other `#[fundamental]` + // types, too. + self.tcx.visibility(def.did()).is_accessible_from(body_def_id, self.tcx) + } else { + true + } + }) + .collect(); + + impl_candidates.sort_by_key(|tr| tr.to_string()); + impl_candidates.dedup(); + impl_candidates + }; + + // We'll check for the case where the reason for the mismatch is that the trait comes from + // one crate version and the type comes from another crate version, even though they both + // are from the same crate. + let trait_def_id = trait_ref.def_id(); + if let ty::Adt(def, _) = trait_ref.self_ty().skip_binder().peel_refs().kind() + && let found_type = def.did() + && trait_def_id.krate != found_type.krate + && self.tcx.crate_name(trait_def_id.krate) == self.tcx.crate_name(found_type.krate) + { + let name = self.tcx.crate_name(trait_def_id.krate); + let spans: Vec<_> = [trait_def_id, found_type] + .into_iter() + .filter_map(|def_id| self.tcx.extern_crate(def_id)) + .map(|data| { + let dependency = if data.dependency_of == LOCAL_CRATE { + "direct dependency of the current crate".to_string() + } else { + let dep = self.tcx.crate_name(data.dependency_of); + format!("dependency of crate `{dep}`") + }; + ( + data.span, + format!("one version of crate `{name}` is used here, as a {dependency}"), + ) + }) + .collect(); + let mut span: MultiSpan = spans.iter().map(|(sp, _)| *sp).collect::<Vec<Span>>().into(); + for (sp, label) in spans.into_iter() { + span.push_span_label(sp, label); + } + err.highlighted_span_help( + span, + vec![ + StringPart::normal("you have ".to_string()), + StringPart::highlighted("multiple different versions".to_string()), + StringPart::normal(" of crate `".to_string()), + StringPart::highlighted(format!("{name}")), + StringPart::normal("` in your dependency graph".to_string()), + ], + ); + let candidates = if impl_candidates.is_empty() { + alternative_candidates(trait_def_id) + } else { + impl_candidates.into_iter().map(|cand| cand.trait_ref).collect() + }; + if let Some((sp_candidate, sp_found)) = candidates.iter().find_map(|trait_ref| { + if let ty::Adt(def, _) = trait_ref.self_ty().peel_refs().kind() + && let candidate_def_id = def.did() + && let Some(name) = self.tcx.opt_item_name(candidate_def_id) + && let Some(found) = self.tcx.opt_item_name(found_type) + && name == found + && candidate_def_id.krate != found_type.krate + && self.tcx.crate_name(candidate_def_id.krate) + == self.tcx.crate_name(found_type.krate) + { + // A candidate was found of an item with the same name, from two separate + // versions of the same crate, let's clarify. + Some((self.tcx.def_span(candidate_def_id), self.tcx.def_span(found_type))) + } else { + None + } + }) { + let mut span: MultiSpan = vec![sp_candidate, sp_found].into(); + span.push_span_label(self.tcx.def_span(trait_def_id), "this is the required trait"); + span.push_span_label(sp_candidate, "this type implements the required trait"); + span.push_span_label(sp_found, "this type doesn't implement the required trait"); + err.highlighted_span_note( + span, + vec![ + StringPart::normal( + "two types coming from two different versions of the same crate are \ + different types " + .to_string(), + ), + StringPart::highlighted("even if they look the same".to_string()), + ], + ); + } + err.help("you can use `cargo tree` to explore your dependency tree"); + return true; + } + if let [single] = &impl_candidates { + // If we have a single implementation, try to unify it with the trait ref + // that failed. This should uncover a better hint for what *is* implemented. if self.probe(|_| { let ocx = ObligationCtxt::new(self); @@ -1798,43 +1921,7 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> { // Mentioning implementers of `Copy`, `Debug` and friends is not useful. return false; } - let mut impl_candidates: Vec<_> = self - .tcx - .all_impls(def_id) - // ignore `do_not_recommend` items - .filter(|def_id| { - !self - .tcx - .has_attrs_with_path(*def_id, &[sym::diagnostic, sym::do_not_recommend]) - }) - // Ignore automatically derived impls and `!Trait` impls. - .filter_map(|def_id| self.tcx.impl_trait_header(def_id)) - .filter_map(|header| { - (header.polarity != ty::ImplPolarity::Negative - || self.tcx.is_automatically_derived(def_id)) - .then(|| header.trait_ref.instantiate_identity()) - }) - .filter(|trait_ref| { - let self_ty = trait_ref.self_ty(); - // Avoid mentioning type parameters. - if let ty::Param(_) = self_ty.kind() { - false - } - // Avoid mentioning types that are private to another crate - else if let ty::Adt(def, _) = self_ty.peel_refs().kind() { - // FIXME(compiler-errors): This could be generalized, both to - // be more granular, and probably look past other `#[fundamental]` - // types, too. - self.tcx.visibility(def.did()).is_accessible_from(body_def_id, self.tcx) - } else { - true - } - }) - .collect(); - - impl_candidates.sort_by_key(|tr| tr.to_string()); - impl_candidates.dedup(); - return report(impl_candidates, err); + return report(alternative_candidates(def_id), err); } // Sort impl candidates so that ordering is consistent for UI tests. diff --git a/compiler/rustc_trait_selection/src/traits/mod.rs b/compiler/rustc_trait_selection/src/traits/mod.rs index f7b8d99593e..a350b76a704 100644 --- a/compiler/rustc_trait_selection/src/traits/mod.rs +++ b/compiler/rustc_trait_selection/src/traits/mod.rs @@ -62,7 +62,7 @@ pub use self::specialize::{ }; pub use self::structural_normalize::StructurallyNormalizeExt; pub use self::util::{ - elaborate, expand_trait_aliases, impl_item_is_final, supertraits, transitive_bounds, + elaborate, expand_trait_aliases, impl_item_is_final, supertraits, transitive_bounds_that_define_assoc_item, upcast_choices, with_replaced_escaping_bound_vars, BoundVarReplacer, PlaceholderReplacer, TraitAliasExpander, TraitAliasExpansionInfo, }; diff --git a/compiler/rustc_trait_selection/src/traits/select/mod.rs b/compiler/rustc_trait_selection/src/traits/select/mod.rs index cc9174d3aad..1d9a90f0300 100644 --- a/compiler/rustc_trait_selection/src/traits/select/mod.rs +++ b/compiler/rustc_trait_selection/src/traits/select/mod.rs @@ -7,6 +7,7 @@ use std::fmt::{self, Display}; use std::ops::ControlFlow; use std::{cmp, iter}; +use hir::def::DefKind; use rustc_data_structures::fx::{FxHashSet, FxIndexMap, FxIndexSet}; use rustc_data_structures::stack::ensure_sufficient_stack; use rustc_errors::{Diag, EmissionGuarantee}; @@ -14,8 +15,9 @@ use rustc_hir as hir; use rustc_hir::def_id::DefId; use rustc_hir::LangItem; use rustc_infer::infer::relate::TypeRelation; -use rustc_infer::infer::BoundRegionConversionTime::HigherRankedType; -use rustc_infer::infer::{BoundRegionConversionTime, DefineOpaqueTypes}; +use rustc_infer::infer::BoundRegionConversionTime::{self, HigherRankedType}; +use rustc_infer::infer::DefineOpaqueTypes; +use rustc_infer::traits::util::elaborate; use rustc_infer::traits::TraitObligation; use rustc_middle::bug; use rustc_middle::dep_graph::{dep_kinds, DepNodeIndex}; @@ -2798,6 +2800,35 @@ impl<'tcx> SelectionContext<'_, 'tcx> { }); } + // Register any outlives obligations from the trait here, cc #124336. + if matches!(self.tcx().def_kind(def_id), DefKind::Impl { of_trait: true }) + && let Some(header) = self.tcx().impl_trait_header(def_id) + { + let trait_clause: ty::Clause<'tcx> = + header.trait_ref.instantiate(self.tcx(), args).upcast(self.tcx()); + for clause in elaborate(self.tcx(), [trait_clause]) { + if matches!( + clause.kind().skip_binder(), + ty::ClauseKind::TypeOutlives(..) | ty::ClauseKind::RegionOutlives(..) + ) { + let clause = normalize_with_depth_to( + self, + param_env, + cause.clone(), + recursion_depth, + clause, + &mut obligations, + ); + obligations.push(Obligation { + cause: cause.clone(), + recursion_depth, + param_env, + predicate: clause.as_predicate(), + }); + } + } + } + obligations } } |