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Link impl items to corresponding trait items in late resolver.

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This commit is contained in:
Camille GILLOT 2022-01-08 12:22:06 +01:00
parent 488acf86a7
commit 1be6e2d6e9
9 changed files with 114 additions and 162 deletions
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106
compiler/rustc_ty_utils/src/assoc.rs
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@ -1,8 +1,7 @@
use rustc_data_structures::fx::FxHashMap;
use rustc_errors::struct_span_err;
use rustc_hir as hir;
use rustc_hir::def_id::{DefId, LocalDefId};
use rustc_middle::ty::{self, TyCtxt, TypeFoldable};
use rustc_middle::ty::{self, TyCtxt};
pub fn provide(providers: &mut ty::query::Providers) {
*providers = ty::query::Providers {
@ -125,115 +124,14 @@ fn associated_item_from_impl_item_ref(
hir::AssocItemKind::Type => (ty::AssocKind::Type, false),
};
let trait_item_def_id = impl_item_base_id(tcx, parent_def_id, impl_item_ref);
ty::AssocItem {
ident: impl_item_ref.ident,
kind,
vis: tcx.visibility(def_id),
defaultness: impl_item_ref.defaultness,
def_id: def_id.to_def_id(),
trait_item_def_id,
trait_item_def_id: impl_item_ref.trait_item_def_id,
container: ty::ImplContainer(parent_def_id.to_def_id()),
fn_has_self_parameter: has_self,
}
}
fn impl_item_base_id<'tcx>(
tcx: TyCtxt<'tcx>,
parent_def_id: LocalDefId,
impl_item: &hir::ImplItemRef,
) -> Option<DefId> {
let impl_trait_ref = tcx.impl_trait_ref(parent_def_id)?;
// If the trait reference itself is erroneous (so the compilation is going
// to fail), skip checking the items here -- the `impl_item` table in `tcx`
// isn't populated for such impls.
if impl_trait_ref.references_error() {
return None;
}
// Locate trait items
let associated_items = tcx.associated_items(impl_trait_ref.def_id);
// Match item against trait
let mut items = associated_items.filter_by_name(tcx, impl_item.ident, impl_trait_ref.def_id);
let mut trait_item = items.next()?;
let is_compatible = |ty: &&ty::AssocItem| match (ty.kind, &impl_item.kind) {
(ty::AssocKind::Const, hir::AssocItemKind::Const) => true,
(ty::AssocKind::Fn, hir::AssocItemKind::Fn { .. }) => true,
(ty::AssocKind::Type, hir::AssocItemKind::Type) => true,
_ => false,
};
// If we don't have a compatible item, we'll use the first one whose name matches
// to report an error.
let mut compatible_kind = is_compatible(&trait_item);
if !compatible_kind {
if let Some(ty_trait_item) = items.find(is_compatible) {
compatible_kind = true;
trait_item = ty_trait_item;
}
}
if compatible_kind {
Some(trait_item.def_id)
} else {
report_mismatch_error(tcx, trait_item.def_id, impl_trait_ref, impl_item);
None
}
}
#[inline(never)]
#[cold]
fn report_mismatch_error<'tcx>(
tcx: TyCtxt<'tcx>,
trait_item_def_id: DefId,
impl_trait_ref: ty::TraitRef<'tcx>,
impl_item: &hir::ImplItemRef,
) {
let mut err = match impl_item.kind {
hir::AssocItemKind::Const => {
// Find associated const definition.
struct_span_err!(
tcx.sess,
impl_item.span,
E0323,
"item `{}` is an associated const, which doesn't match its trait `{}`",
impl_item.ident,
impl_trait_ref.print_only_trait_path()
)
}
hir::AssocItemKind::Fn { .. } => {
struct_span_err!(
tcx.sess,
impl_item.span,
E0324,
"item `{}` is an associated method, which doesn't match its trait `{}`",
impl_item.ident,
impl_trait_ref.print_only_trait_path()
)
}
hir::AssocItemKind::Type => {
struct_span_err!(
tcx.sess,
impl_item.span,
E0325,
"item `{}` is an associated type, which doesn't match its trait `{}`",
impl_item.ident,
impl_trait_ref.print_only_trait_path()
)
}
};
err.span_label(impl_item.span, "does not match trait");
if let Some(trait_span) = tcx.hir().span_if_local(trait_item_def_id) {
err.span_label(trait_span, "item in trait");
}
err.emit();
}