bjoernager/rust
bjoernager/rust
1
Fork 0
Code Issues Pull requests Activity

Properly deal with GATs when looking for method chains to point at

Browse source
This commit is contained in:
León Orell Valerian Liehr 2024-03-02 19:29:53 +01:00
parent 5257aee7dd
commit 6035e8735a
No known key found for this signature in database
GPG key ID: D17A07215F68E713
4 changed files with 63 additions and 16 deletions
Download patch file Download diff file Expand all files Collapse all files

1
compiler/rustc_trait_selection/src/lib.rs
View file

@ -16,6 +16,7 @@
#![allow(internal_features)]
#![allow(rustc::diagnostic_outside_of_impl)]
#![allow(rustc::untranslatable_diagnostic)]
#![feature(assert_matches)]
#![feature(associated_type_bounds)]
#![feature(box_patterns)]
#![feature(control_flow_enum)]

29
compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
View file

@ -38,6 +38,7 @@ use rustc_span::def_id::LocalDefId;
use rustc_span::symbol::{kw, sym, Ident, Symbol};
use rustc_span::{BytePos, DesugaringKind, ExpnKind, MacroKind, Span, DUMMY_SP};
use rustc_target::spec::abi;
use std::assert_matches::debug_assert_matches;
use std::borrow::Cow;
use std::iter;
@ -4219,30 +4220,25 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
};
let origin = TypeVariableOrigin { kind: TypeVariableOriginKind::TypeInference, span };
let trait_def_id = proj.trait_def_id(self.tcx);
// Make `Self` be equivalent to the type of the call chain
// expression we're looking at now, so that we can tell what
// for example `Iterator::Item` is at this point in the chain.
let args = GenericArgs::for_item(self.tcx, trait_def_id, |param, _| {
match param.kind {
ty::GenericParamDefKind::Type { .. } => {
if param.index == 0 {
return prev_ty.into();
}
}
ty::GenericParamDefKind::Lifetime | ty::GenericParamDefKind::Const { .. } => {}
let args = GenericArgs::for_item(self.tcx, proj.def_id, |param, _| {
if param.index == 0 {
debug_assert_matches!(param.kind, ty::GenericParamDefKind::Type { .. });
return prev_ty.into();
}
self.var_for_def(span, param)
});
// This will hold the resolved type of the associated type, if the
// current expression implements the trait that associated type is
// in. For example, this would be what `Iterator::Item` is here.
let ty_var = self.infcx.next_ty_var(origin);
let ty = self.infcx.next_ty_var(origin);
// This corresponds to `<ExprTy as Iterator>::Item = _`.
let projection = ty::Binder::dummy(ty::PredicateKind::Clause(
ty::ClauseKind::Projection(ty::ProjectionPredicate {
projection_ty: ty::AliasTy::new(self.tcx, proj.def_id, args),
term: ty_var.into(),
term: ty.into(),
}),
));
let body_def_id = self.tcx.hir().enclosing_body_owner(body_id);
@ -4254,14 +4250,15 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
param_env,
projection,
));
if ocx.select_where_possible().is_empty() {
// `ty_var` now holds the type that `Item` is for `ExprTy`.
let ty_var = self.resolve_vars_if_possible(ty_var);
assocs_in_this_method.push(Some((span, (proj.def_id, ty_var))));
if ocx.select_where_possible().is_empty()
&& let ty = self.resolve_vars_if_possible(ty)
&& !ty.is_ty_var()
{
assocs_in_this_method.push(Some((span, (proj.def_id, ty))));
} else {
// `<ExprTy as Iterator>` didn't select, so likely we've
// reached the end of the iterator chain, like the originating
// `Vec<_>`.
// `Vec<_>` or the `ty` couldn't be determined.
// Keep the space consistent for later zipping.
assocs_in_this_method.push(None);
}