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|
use rustc_ast::TraitObjectSyntax;
use rustc_errors::{Diagnostic, StashKey};
use rustc_hir as hir;
use rustc_lint_defs::{builtin::BARE_TRAIT_OBJECTS, Applicability};
use rustc_trait_selection::traits::error_reporting::suggestions::NextTypeParamName;
use super::AstConv;
impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
/// Make sure that we are in the condition to suggest the blanket implementation.
pub(super) fn maybe_lint_blanket_trait_impl(
&self,
self_ty: &hir::Ty<'_>,
diag: &mut Diagnostic,
) {
let tcx = self.tcx();
let parent_id = tcx.hir().get_parent_item(self_ty.hir_id).def_id;
if let hir::Node::Item(hir::Item {
kind:
hir::ItemKind::Impl(hir::Impl {
self_ty: impl_self_ty,
of_trait: Some(of_trait_ref),
generics,
..
}),
..
}) = tcx.hir().get_by_def_id(parent_id)
&& self_ty.hir_id == impl_self_ty.hir_id
{
if !of_trait_ref.trait_def_id().is_some_and(|def_id| def_id.is_local()) {
return;
}
let of_trait_span = of_trait_ref.path.span;
// make sure that we are not calling unwrap to abort during the compilation
let Ok(impl_trait_name) = tcx.sess.source_map().span_to_snippet(self_ty.span) else {
return;
};
let Ok(of_trait_name) = tcx.sess.source_map().span_to_snippet(of_trait_span) else {
return;
};
// check if the trait has generics, to make a correct suggestion
let param_name = generics.params.next_type_param_name(None);
let add_generic_sugg = if let Some(span) = generics.span_for_param_suggestion() {
(span, format!(", {param_name}: {impl_trait_name}"))
} else {
(generics.span, format!("<{param_name}: {impl_trait_name}>"))
};
diag.multipart_suggestion(
format!(
"alternatively use a blanket \
implementation to implement `{of_trait_name}` for \
all types that also implement `{impl_trait_name}`"
),
vec![(self_ty.span, param_name), add_generic_sugg],
Applicability::MaybeIncorrect,
);
}
}
pub(super) fn maybe_lint_bare_trait(&self, self_ty: &hir::Ty<'_>, in_path: bool) {
let tcx = self.tcx();
if let hir::TyKind::TraitObject([poly_trait_ref, ..], _, TraitObjectSyntax::None) =
self_ty.kind
{
let needs_bracket = in_path
&& !tcx
.sess
.source_map()
.span_to_prev_source(self_ty.span)
.ok()
.is_some_and(|s| s.trim_end().ends_with('<'));
let is_global = poly_trait_ref.trait_ref.path.is_global();
let mut sugg = Vec::from_iter([(
self_ty.span.shrink_to_lo(),
format!(
"{}dyn {}",
if needs_bracket { "<" } else { "" },
if is_global { "(" } else { "" },
),
)]);
if is_global || needs_bracket {
sugg.push((
self_ty.span.shrink_to_hi(),
format!(
"{}{}",
if is_global { ")" } else { "" },
if needs_bracket { ">" } else { "" },
),
));
}
if self_ty.span.edition().at_least_rust_2021() {
let msg = "trait objects must include the `dyn` keyword";
let label = "add `dyn` keyword before this trait";
let mut diag =
rustc_errors::struct_span_err!(tcx.sess, self_ty.span, E0782, "{}", msg);
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.stash(self_ty.span, StashKey::TraitMissingMethod);
} else {
let msg = "trait objects without an explicit `dyn` are deprecated";
tcx.struct_span_lint_hir(
BARE_TRAIT_OBJECTS,
self_ty.hir_id,
self_ty.span,
msg,
|lint| {
lint.multipart_suggestion_verbose(
"use `dyn`",
sugg,
Applicability::MachineApplicable,
);
self.maybe_lint_blanket_trait_impl(&self_ty, lint);
lint
},
);
}
}
}
}
|
