use rustc_hir::def_id::{DefId, LocalDefId};
use rustc_hir::intravisit::{walk_generics, Visitor as _};
use rustc_hir::{GenericArg, GenericArgs, OpaqueTyOrigin};
+use rustc_infer::infer::TyCtxtInferExt;
use rustc_middle::middle::stability::AllowUnstable;
use rustc_middle::ty::subst::{self, GenericArgKind, InternalSubsts, SubstsRef};
use rustc_middle::ty::GenericParamDefKind;
return tcx.const_error(ty).into();
}
if !infer_args && has_default {
- tcx.bound_const_param_default(param.def_id)
- .subst(tcx, substs.unwrap())
- .into()
+ tcx.const_param_default(param.def_id).subst(tcx, substs.unwrap()).into()
} else {
if infer_args {
self.astconv.ct_infer(ty, Some(param), self.span).into()
/// ```
///
/// The `sized_by_default` parameter indicates if, in this context, the `param_ty` should be
- /// considered `Sized` unless there is an explicit `?Sized` bound. This would be true in the
+ /// considered `Sized` unless there is an explicit `?Sized` bound. This would be true in the
/// example above, but is not true in supertrait listings like `trait Foo: Bar + Baz`.
///
/// `span` should be the declaration size of the parameter.
i.trait_ref().map_bound(|trait_ref: ty::TraitRef<'tcx>| {
assert_eq!(trait_ref.self_ty(), dummy_self);
- // Verify that `dummy_self` did not leak inside default type parameters. This
+ // Verify that `dummy_self` did not leak inside default type parameters. This
// could not be done at path creation, since we need to see through trait aliases.
let mut missing_type_params = vec![];
let mut references_self = false;
fn report_ambiguous_associated_type(
&self,
span: Span,
- type_str: &str,
- trait_str: &str,
+ types: &[String],
+ traits: &[String],
name: Symbol,
) -> ErrorGuaranteed {
let mut err = struct_span_err!(self.tcx().sess, span, E0223, "ambiguous associated type");
.keys()
.any(|full_span| full_span.contains(span))
{
- err.span_suggestion(
+ err.span_suggestion_verbose(
span.shrink_to_lo(),
"you are looking for the module in `std`, not the primitive type",
"std::",
Applicability::MachineApplicable,
);
} else {
- err.span_suggestion(
- span,
- "use fully-qualified syntax",
- format!("<{} as {}>::{}", type_str, trait_str, name),
- Applicability::HasPlaceholders,
- );
+ match (types, traits) {
+ ([], []) => {
+ err.span_suggestion_verbose(
+ span,
+ &format!(
+ "if there were a type named `Type` that implements a trait named \
+ `Trait` with associated type `{name}`, you could use the \
+ fully-qualified path",
+ ),
+ format!("<Type as Trait>::{name}"),
+ Applicability::HasPlaceholders,
+ );
+ }
+ ([], [trait_str]) => {
+ err.span_suggestion_verbose(
+ span,
+ &format!(
+ "if there were a type named `Example` that implemented `{trait_str}`, \
+ you could use the fully-qualified path",
+ ),
+ format!("<Example as {trait_str}>::{name}"),
+ Applicability::HasPlaceholders,
+ );
+ }
+ ([], traits) => {
+ err.span_suggestions(
+ span,
+ &format!(
+ "if there were a type named `Example` that implemented one of the \
+ traits with associated type `{name}`, you could use the \
+ fully-qualified path",
+ ),
+ traits
+ .iter()
+ .map(|trait_str| format!("<Example as {trait_str}>::{name}"))
+ .collect::<Vec<_>>(),
+ Applicability::HasPlaceholders,
+ );
+ }
+ ([type_str], []) => {
+ err.span_suggestion_verbose(
+ span,
+ &format!(
+ "if there were a trait named `Example` with associated type `{name}` \
+ implemented for `{type_str}`, you could use the fully-qualified path",
+ ),
+ format!("<{type_str} as Example>::{name}"),
+ Applicability::HasPlaceholders,
+ );
+ }
+ (types, []) => {
+ err.span_suggestions(
+ span,
+ &format!(
+ "if there were a trait named `Example` with associated type `{name}` \
+ implemented for one of the types, you could use the fully-qualified \
+ path",
+ ),
+ types
+ .into_iter()
+ .map(|type_str| format!("<{type_str} as Example>::{name}")),
+ Applicability::HasPlaceholders,
+ );
+ }
+ (types, traits) => {
+ let mut suggestions = vec![];
+ for type_str in types {
+ for trait_str in traits {
+ suggestions.push(format!("<{type_str} as {trait_str}>::{name}"));
+ }
+ }
+ err.span_suggestions(
+ span,
+ "use the fully-qualified path",
+ suggestions,
+ Applicability::MachineApplicable,
+ );
+ }
+ }
}
err.emit()
}
};
self.one_bound_for_assoc_type(
- || traits::supertraits(tcx, ty::Binder::dummy(trait_ref)),
+ || traits::supertraits(tcx, ty::Binder::dummy(trait_ref.subst_identity())),
|| "Self".to_string(),
assoc_ident,
span,
err.emit()
} else if let Err(reported) = qself_ty.error_reported() {
reported
+ } else if let ty::Alias(ty::Opaque, alias_ty) = qself_ty.kind() {
+ // `<impl Trait as OtherTrait>::Assoc` makes no sense.
+ struct_span_err!(
+ tcx.sess,
+ tcx.def_span(alias_ty.def_id),
+ E0667,
+ "`impl Trait` is not allowed in path parameters"
+ )
+ .emit() // Already reported in an earlier stage.
} else {
+ // Find all the `impl`s that `qself_ty` has for any trait that has the
+ // associated type, so that we suggest the right one.
+ let infcx = tcx.infer_ctxt().build();
+ // We create a fresh `ty::ParamEnv` instead of the one for `self.item_def_id()`
+ // to avoid a cycle error in `src/test/ui/resolve/issue-102946.rs`.
+ let param_env = ty::ParamEnv::empty();
+ let traits: Vec<_> = self
+ .tcx()
+ .all_traits()
+ .filter(|trait_def_id| {
+ // Consider only traits with the associated type
+ tcx.associated_items(*trait_def_id)
+ .in_definition_order()
+ .any(|i| {
+ i.kind.namespace() == Namespace::TypeNS
+ && i.ident(tcx).normalize_to_macros_2_0() == assoc_ident
+ && matches!(i.kind, ty::AssocKind::Type)
+ })
+ // Consider only accessible traits
+ && tcx.visibility(*trait_def_id)
+ .is_accessible_from(self.item_def_id(), tcx)
+ && tcx.all_impls(*trait_def_id)
+ .any(|impl_def_id| {
+ let trait_ref = tcx.impl_trait_ref(impl_def_id);
+ trait_ref.map_or(false, |trait_ref| {
+ let impl_ = trait_ref.subst(
+ tcx,
+ infcx.fresh_substs_for_item(span, impl_def_id),
+ );
+ infcx
+ .can_eq(
+ param_env,
+ tcx.erase_regions(impl_.self_ty()),
+ tcx.erase_regions(qself_ty),
+ )
+ .is_ok()
+ })
+ && tcx.impl_polarity(impl_def_id) != ty::ImplPolarity::Negative
+ })
+ })
+ .map(|trait_def_id| tcx.def_path_str(trait_def_id))
+ .collect();
+
// Don't print `TyErr` to the user.
self.report_ambiguous_associated_type(
span,
- &qself_ty.to_string(),
- "Trait",
+ &[qself_ty.to_string()],
+ &traits,
assoc_ident.name,
)
};
let is_part_of_self_trait_constraints = def_id == trait_def_id;
let is_part_of_fn_in_self_trait = parent_def_id == Some(trait_def_id);
- let type_name = if is_part_of_self_trait_constraints || is_part_of_fn_in_self_trait {
- "Self"
+ let type_names = if is_part_of_self_trait_constraints || is_part_of_fn_in_self_trait {
+ vec!["Self".to_string()]
} else {
- "Type"
+ // Find all the types that have an `impl` for the trait.
+ tcx.all_impls(trait_def_id)
+ .filter(|impl_def_id| {
+ // Consider only accessible traits
+ tcx.visibility(*impl_def_id).is_accessible_from(self.item_def_id(), tcx)
+ && tcx.impl_polarity(impl_def_id) != ty::ImplPolarity::Negative
+ })
+ .filter_map(|impl_def_id| tcx.impl_trait_ref(impl_def_id))
+ .map(|impl_| impl_.subst_identity().self_ty())
+ // We don't care about blanket impls.
+ .filter(|self_ty| !self_ty.has_non_region_param())
+ .map(|self_ty| tcx.erase_regions(self_ty).to_string())
+ .collect()
};
-
+ // FIXME: also look at `tcx.generics_of(self.item_def_id()).params` any that
+ // references the trait. Relevant for the first case in
+ // `src/test/ui/associated-types/associated-types-in-ambiguous-context.rs`
let reported = self.report_ambiguous_associated_type(
span,
- type_name,
- &path_str,
+ &type_names,
+ &[path_str],
item_segment.ident.name,
);
return tcx.ty_error_with_guaranteed(reported)
}
/// Parses the programmer's textual representation of a type into our
- /// internal notion of a type. This is meant to be used within a path.
+ /// internal notion of a type. This is meant to be used within a path.
pub fn ast_ty_to_ty_in_path(&self, ast_ty: &hir::Ty<'_>) -> Ty<'tcx> {
self.ast_ty_to_ty_inner(ast_ty, false, true)
}
let label = "add `dyn` keyword before this trait";
let mut diag =
rustc_errors::struct_span_err!(tcx.sess, self_ty.span, E0782, "{}", msg);
- diag.multipart_suggestion_verbose(label, sugg, Applicability::MachineApplicable);
+ if self_ty.span.can_be_used_for_suggestions() {
+ diag.multipart_suggestion_verbose(
+ label,
+ sugg,
+ Applicability::MachineApplicable,
+ );
+ }
// check if the impl trait that we are considering is a impl of a local trait
self.maybe_lint_blanket_trait_impl(&self_ty, &mut diag);
diag.emit();
projects / rust.git / blobdiff