From 898448ca5872aed82920dbb8342096e25e50aa5a Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Le=C3=B3n=20Orell=20Valerian=20Liehr?= Date: Fri, 14 Jun 2024 12:28:23 +0200 Subject: [PATCH] HIR ty lowering: Refactor the way the projectee ("QSelf") gets passed to diagnostics --- compiler/rustc_hir_analysis/messages.ftl | 6 +- compiler/rustc_hir_analysis/src/errors.rs | 6 +- .../src/hir_ty_lowering/bounds.rs | 9 +-- .../src/hir_ty_lowering/errors.rs | 59 +++++++++------ .../src/hir_ty_lowering/mod.rs | 75 ++++++++++--------- 5 files changed, 86 insertions(+), 69 deletions(-) diff --git a/compiler/rustc_hir_analysis/messages.ftl b/compiler/rustc_hir_analysis/messages.ftl index cc404daa51f..c209bf20c43 100644 --- a/compiler/rustc_hir_analysis/messages.ftl +++ b/compiler/rustc_hir_analysis/messages.ftl @@ -1,4 +1,4 @@ -hir_analysis_ambiguous_assoc_item = ambiguous associated {$assoc_kind} `{$assoc_name}` in bounds of `{$ty_param_name}` +hir_analysis_ambiguous_assoc_item = ambiguous associated {$assoc_kind} `{$assoc_name}` in bounds of `{$qself}` .label = ambiguous associated {$assoc_kind} `{$assoc_name}` hir_analysis_ambiguous_lifetime_bound = @@ -12,14 +12,14 @@ hir_analysis_assoc_item_is_private = {$kind} `{$name}` is private .label = private {$kind} .defined_here_label = the {$kind} is defined here -hir_analysis_assoc_item_not_found = associated {$assoc_kind} `{$assoc_name}` not found for `{$ty_param_name}` +hir_analysis_assoc_item_not_found = associated {$assoc_kind} `{$assoc_name}` not found for `{$qself}` hir_analysis_assoc_item_not_found_found_in_other_trait_label = there is {$identically_named -> [true] an *[false] a similarly named } associated {$assoc_kind} `{$suggested_name}` in the trait `{$trait_name}` hir_analysis_assoc_item_not_found_label = associated {$assoc_kind} `{$assoc_name}` not found -hir_analysis_assoc_item_not_found_other_sugg = `{$ty_param_name}` has the following associated {$assoc_kind} +hir_analysis_assoc_item_not_found_other_sugg = `{$qself}` has the following associated {$assoc_kind} hir_analysis_assoc_item_not_found_similar_in_other_trait_sugg = change the associated {$assoc_kind} name to use `{$suggested_name}` from `{$trait_name}` hir_analysis_assoc_item_not_found_similar_in_other_trait_with_bound_sugg = and also change the associated {$assoc_kind} name hir_analysis_assoc_item_not_found_similar_sugg = there is an associated {$assoc_kind} with a similar name diff --git a/compiler/rustc_hir_analysis/src/errors.rs b/compiler/rustc_hir_analysis/src/errors.rs index d1f9ad9d58b..8e8b3b3d32a 100644 --- a/compiler/rustc_hir_analysis/src/errors.rs +++ b/compiler/rustc_hir_analysis/src/errors.rs @@ -22,7 +22,7 @@ pub struct AmbiguousAssocItem<'a> { pub span: Span, pub assoc_kind: &'static str, pub assoc_name: Ident, - pub ty_param_name: &'a str, + pub qself: &'a str, } #[derive(Diagnostic)] @@ -75,7 +75,7 @@ pub struct AssocItemNotFound<'a> { pub span: Span, pub assoc_name: Ident, pub assoc_kind: &'static str, - pub ty_param_name: &'a str, + pub qself: &'a str, #[subdiagnostic] pub label: Option>, #[subdiagnostic] @@ -134,7 +134,7 @@ pub enum AssocItemNotFoundSugg<'a> { Other { #[primary_span] span: Span, - ty_param_name: &'a str, + qself: &'a str, assoc_kind: &'static str, suggested_name: Symbol, }, diff --git a/compiler/rustc_hir_analysis/src/hir_ty_lowering/bounds.rs b/compiler/rustc_hir_analysis/src/hir_ty_lowering/bounds.rs index 6f9c481650b..214eb6b2f06 100644 --- a/compiler/rustc_hir_analysis/src/hir_ty_lowering/bounds.rs +++ b/compiler/rustc_hir_analysis/src/hir_ty_lowering/bounds.rs @@ -6,7 +6,6 @@ use rustc_hir::def::{DefKind, Res}; use rustc_hir::def_id::{DefId, LocalDefId}; use rustc_middle::bug; -use rustc_middle::ty::print::PrintTraitRefExt as _; use rustc_middle::ty::{self as ty, IsSuggestable, Ty, TyCtxt}; use rustc_span::symbol::Ident; use rustc_span::{ErrorGuaranteed, Span, Symbol}; @@ -16,9 +15,8 @@ use crate::bounds::Bounds; use crate::errors; -use crate::hir_ty_lowering::{HirTyLowerer, OnlySelfBounds, PredicateFilter}; - -use super::RegionInferReason; +use crate::hir_ty_lowering::HirTyLowerer; +use crate::hir_ty_lowering::{AssocItemQSelf, OnlySelfBounds, PredicateFilter, RegionInferReason}; impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { /// Add a `Sized` bound to the `bounds` if appropriate. @@ -288,8 +286,7 @@ pub(super) fn lower_assoc_item_constraint( // one that does define it. self.probe_single_bound_for_assoc_item( || traits::supertraits(tcx, trait_ref), - trait_ref.skip_binder().print_only_trait_name(), - None, + AssocItemQSelf::Trait(trait_ref.def_id()), assoc_kind, constraint.ident, path_span, diff --git a/compiler/rustc_hir_analysis/src/hir_ty_lowering/errors.rs b/compiler/rustc_hir_analysis/src/hir_ty_lowering/errors.rs index 40675a1edba..ca741e4fbb6 100644 --- a/compiler/rustc_hir_analysis/src/hir_ty_lowering/errors.rs +++ b/compiler/rustc_hir_analysis/src/hir_ty_lowering/errors.rs @@ -3,7 +3,7 @@ ParenthesizedFnTraitExpansion, TraitObjectDeclaredWithNoTraits, }; use crate::fluent_generated as fluent; -use crate::hir_ty_lowering::HirTyLowerer; +use crate::hir_ty_lowering::{AssocItemQSelf, HirTyLowerer}; use rustc_data_structures::fx::{FxIndexMap, FxIndexSet}; use rustc_data_structures::sorted_map::SortedMap; use rustc_data_structures::unord::UnordMap; @@ -11,9 +11,9 @@ use rustc_errors::{ codes::*, pluralize, struct_span_code_err, Applicability, Diag, ErrorGuaranteed, }; +use rustc_hir as hir; use rustc_hir::def::{DefKind, Res}; -use rustc_hir::def_id::{DefId, LocalDefId}; -use rustc_hir::{self as hir, Node}; +use rustc_hir::def_id::DefId; use rustc_middle::bug; use rustc_middle::query::Key; use rustc_middle::ty::print::{PrintPolyTraitRefExt as _, PrintTraitRefExt as _}; @@ -116,8 +116,7 @@ pub(crate) fn complain_about_internal_fn_trait( pub(super) fn complain_about_assoc_item_not_found( &self, all_candidates: impl Fn() -> I, - ty_param_name: &str, - ty_param_def_id: Option, + qself: AssocItemQSelf, assoc_kind: ty::AssocKind, assoc_name: Ident, span: Span, @@ -139,7 +138,8 @@ pub(super) fn complain_about_assoc_item_not_found( ); } - let assoc_kind_str = super::assoc_kind_str(assoc_kind); + let assoc_kind_str = assoc_kind_str(assoc_kind); + let qself_str = qself.to_string(tcx); // The fallback span is needed because `assoc_name` might be an `Fn()`'s `Output` without a // valid span, so we point at the whole path segment instead. @@ -149,7 +149,7 @@ pub(super) fn complain_about_assoc_item_not_found( span: if is_dummy { span } else { assoc_name.span }, assoc_name, assoc_kind: assoc_kind_str, - ty_param_name, + qself: &qself_str, label: None, sugg: None, }; @@ -219,19 +219,28 @@ pub(super) fn complain_about_assoc_item_not_found( suggested_name, identically_named: suggested_name == assoc_name.name, }); - let hir = tcx.hir(); - if let Some(def_id) = ty_param_def_id - && let parent = hir.get_parent_item(tcx.local_def_id_to_hir_id(def_id)) - && let Some(generics) = hir.get_generics(parent.def_id) + if let AssocItemQSelf::TyParam(ty_param_def_id) = qself + // Not using `self.item_def_id()` here as that would yield the opaque type itself if we're + // inside an opaque type while we're interested in the overarching type alias (TAIT). + // FIXME: However, for trait aliases, this incorrectly returns the enclosing module... + && let item_def_id = + tcx.hir().get_parent_item(tcx.local_def_id_to_hir_id(ty_param_def_id)) + // FIXME: ...which obviously won't have any generics. + && let Some(generics) = tcx.hir().get_generics(item_def_id.def_id) { - if generics.bounds_for_param(def_id).flat_map(|pred| pred.bounds.iter()).any( - |b| match b { + // FIXME: Suggest adding supertrait bounds if we have a `Self` type param. + // FIXME(trait_alias): Suggest adding `Self: Trait` to + // `trait Alias = where Self::Proj:;` with `trait Trait { type Proj; }`. + if generics + .bounds_for_param(ty_param_def_id) + .flat_map(|pred| pred.bounds.iter()) + .any(|b| match b { hir::GenericBound::Trait(t, ..) => { t.trait_ref.trait_def_id() == Some(best_trait) } _ => false, - }, - ) { + }) + { // The type param already has a bound for `trait_name`, we just need to // change the associated item. err.sugg = Some(errors::AssocItemNotFoundSugg::SimilarInOtherTrait { @@ -247,7 +256,7 @@ pub(super) fn complain_about_assoc_item_not_found( tcx, generics, &mut err, - &ty_param_name, + &qself_str, &trait_name, None, None, @@ -273,7 +282,7 @@ pub(super) fn complain_about_assoc_item_not_found( if let [candidate_name] = all_candidate_names.as_slice() { err.sugg = Some(errors::AssocItemNotFoundSugg::Other { span: assoc_name.span, - ty_param_name, + qself: &qself_str, assoc_kind: assoc_kind_str, suggested_name: *candidate_name, }); @@ -339,10 +348,10 @@ fn complain_about_assoc_kind_mismatch( self.dcx().emit_err(errors::AssocKindMismatch { span, - expected: super::assoc_kind_str(expected), - got: super::assoc_kind_str(got), + expected: assoc_kind_str(expected), + got: assoc_kind_str(got), expected_because_label, - assoc_kind: super::assoc_kind_str(assoc_item.kind), + assoc_kind: assoc_kind_str(assoc_item.kind), def_span: tcx.def_span(assoc_item.def_id), bound_on_assoc_const_label, wrap_in_braces_sugg, @@ -736,7 +745,7 @@ pub(crate) fn complain_about_missing_assoc_tys( if let ([], [bound]) = (&potential_assoc_types[..], &trait_bounds) { let grandparent = tcx.parent_hir_node(tcx.parent_hir_id(bound.trait_ref.hir_ref_id)); in_expr_or_pat = match grandparent { - Node::Expr(_) | Node::Pat(_) => true, + hir::Node::Expr(_) | hir::Node::Pat(_) => true, _ => false, }; match bound.trait_ref.path.segments { @@ -1602,3 +1611,11 @@ fn generics_args_err_extend<'a>( _ => {} } } + +pub(super) fn assoc_kind_str(kind: ty::AssocKind) -> &'static str { + match kind { + ty::AssocKind::Fn => "function", + ty::AssocKind::Const => "constant", + ty::AssocKind::Type => "type", + } +} diff --git a/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs b/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs index d6eb1a66902..8d9055076a3 100644 --- a/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs +++ b/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs @@ -55,7 +55,6 @@ use rustc_trait_selection::traits::wf::object_region_bounds; use rustc_trait_selection::traits::{self, ObligationCtxt}; -use std::fmt::Display; use std::slice; /// A path segment that is semantically allowed to have generic arguments. @@ -193,6 +192,25 @@ fn lowerer(&self) -> &dyn HirTyLowerer<'tcx> } } +/// The "qualified self" of an associated item path. +/// +/// For diagnostic purposes only. +enum AssocItemQSelf { + Trait(DefId), + TyParam(LocalDefId), + SelfTyAlias, +} + +impl AssocItemQSelf { + fn to_string(&self, tcx: TyCtxt<'_>) -> String { + match *self { + Self::Trait(def_id) => tcx.def_path_str(def_id), + Self::TyParam(def_id) => tcx.hir().ty_param_name(def_id).to_string(), + Self::SelfTyAlias => kw::SelfUpper.to_string(), + } + } +} + /// New-typed boolean indicating whether explicit late-bound lifetimes /// are present in a set of generic arguments. /// @@ -811,19 +829,14 @@ fn probe_single_ty_param_bound_for_assoc_ty( let predicates = &self.probe_ty_param_bounds(span, ty_param_def_id, assoc_name).predicates; debug!("predicates={:#?}", predicates); - let param_name = tcx.hir().ty_param_name(ty_param_def_id); self.probe_single_bound_for_assoc_item( || { - traits::transitive_bounds_that_define_assoc_item( - tcx, - predicates - .iter() - .filter_map(|(p, _)| Some(p.as_trait_clause()?.map_bound(|t| t.trait_ref))), - assoc_name, - ) + let trait_refs = predicates + .iter() + .filter_map(|(p, _)| Some(p.as_trait_clause()?.map_bound(|t| t.trait_ref))); + traits::transitive_bounds_that_define_assoc_item(tcx, trait_refs, assoc_name) }, - param_name, - Some(ty_param_def_id), + AssocItemQSelf::TyParam(ty_param_def_id), ty::AssocKind::Type, assoc_name, span, @@ -835,12 +848,11 @@ fn probe_single_ty_param_bound_for_assoc_ty( /// /// This fails if there is no such bound in the list of candidates or if there are multiple /// candidates in which case it reports ambiguity. - #[instrument(level = "debug", skip(self, all_candidates, ty_param_name, constraint), ret)] + #[instrument(level = "debug", skip(self, all_candidates, qself, constraint), ret)] fn probe_single_bound_for_assoc_item( &self, all_candidates: impl Fn() -> I, - ty_param_name: impl Display, - ty_param_def_id: Option, + qself: AssocItemQSelf, assoc_kind: ty::AssocKind, assoc_name: Ident, span: Span, @@ -858,8 +870,7 @@ fn probe_single_bound_for_assoc_item( let Some(bound) = matching_candidates.next() else { let reported = self.complain_about_assoc_item_not_found( all_candidates, - &ty_param_name.to_string(), - ty_param_def_id, + qself, assoc_kind, assoc_name, span, @@ -872,13 +883,13 @@ fn probe_single_bound_for_assoc_item( if let Some(bound2) = matching_candidates.next() { debug!(?bound2); - let assoc_kind_str = assoc_kind_str(assoc_kind); - let ty_param_name = &ty_param_name.to_string(); + let assoc_kind_str = errors::assoc_kind_str(assoc_kind); + let qself_str = qself.to_string(tcx); let mut err = self.dcx().create_err(crate::errors::AmbiguousAssocItem { span, assoc_kind: assoc_kind_str, assoc_name, - ty_param_name, + qself: &qself_str, }); // Provide a more specific error code index entry for equality bindings. err.code( @@ -929,7 +940,7 @@ trait = bound.print_only_trait_path(), err.span_suggestion_verbose( span.with_hi(assoc_name.span.lo()), "use fully-qualified syntax to disambiguate", - format!("<{ty_param_name} as {}>::", bound.print_only_trait_path()), + format!("<{qself_str} as {}>::", bound.print_only_trait_path()), Applicability::MaybeIncorrect, ); } @@ -943,7 +954,7 @@ trait = bound.print_only_trait_path(), if !where_bounds.is_empty() { err.help(format!( "consider introducing a new type parameter `T` and adding `where` constraints:\ - \n where\n T: {ty_param_name},\n{}", + \n where\n T: {qself_str},\n{}", where_bounds.join(",\n"), )); } @@ -997,11 +1008,6 @@ pub fn lower_assoc_path( let tcx = self.tcx(); let assoc_ident = assoc_segment.ident; - let qself_res = if let hir::TyKind::Path(hir::QPath::Resolved(_, path)) = &qself.kind { - path.res - } else { - Res::Err - }; // Check if we have an enum variant or an inherent associated type. let mut variant_resolution = None; @@ -1038,6 +1044,12 @@ pub fn lower_assoc_path( } } + let qself_res = if let hir::TyKind::Path(hir::QPath::Resolved(_, path)) = &qself.kind { + path.res + } else { + Res::Err + }; + // Find the type of the associated item, and the trait where the associated // item is declared. let bound = match (&qself_ty.kind(), qself_res) { @@ -1056,8 +1068,7 @@ pub fn lower_assoc_path( ty::Binder::dummy(trait_ref.instantiate_identity()), ) }, - kw::SelfUpper, - None, + AssocItemQSelf::SelfTyAlias, ty::AssocKind::Type, assoc_ident, span, @@ -2522,11 +2533,3 @@ fn compute_object_lifetime_bound( Some(r) } } - -fn assoc_kind_str(kind: ty::AssocKind) -> &'static str { - match kind { - ty::AssocKind::Fn => "function", - ty::AssocKind::Const => "constant", - ty::AssocKind::Type => "type", - } -}