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Small tweaks to the linting code for bare trait object types

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This commit is contained in:
León Orell Valerian Liehr 2024-03-06 19:18:30 +01:00
parent b3df0d7e5e
commit 6b85f075cc
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GPG Key ID: D17A07215F68E713
2 changed files with 79 additions and 72 deletions
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147
compiler/rustc_hir_analysis/src/hir_ty_lowering/lint.rs
View File

@ -9,8 +9,83 @@ use rustc_trait_selection::traits::error_reporting::suggestions::NextTypeParamNa
use super::HirTyLowerer;
impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
/// Prohibit or lint against *bare* trait object types depending on the edition.
///
/// *Bare* trait object types are ones that aren't preceeded by the keyword `dyn`.
/// In edition 2021 and onward we emit a hard error for them.
pub(super) fn prohibit_or_lint_bare_trait_object_ty(
&self,
self_ty: &hir::Ty<'_>,
in_path: bool,
) {
let tcx = self.tcx();
let hir::TyKind::TraitObject([poly_trait_ref, ..], _, TraitObjectSyntax::None) =
self_ty.kind
else {
return;
};
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![(
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_code_err!(tcx.dcx(), self_ty.span, E0782, "{}", msg);
if self_ty.span.can_be_used_for_suggestions()
&& !self.maybe_suggest_impl_trait(self_ty, &mut diag)
{
diag.multipart_suggestion_verbose(label, sugg, Applicability::MachineApplicable);
}
// Check if the impl trait that we are considering is an impl of a local trait.
self.maybe_suggest_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.node_span_lint(BARE_TRAIT_OBJECTS, self_ty.hir_id, self_ty.span, msg, |lint| {
if self_ty.span.can_be_used_for_suggestions() {
lint.multipart_suggestion_verbose(
"if this is an object-safe trait, use `dyn`",
sugg,
Applicability::MachineApplicable,
);
}
self.maybe_suggest_blanket_trait_impl(self_ty, lint);
});
}
}
/// Make sure that we are in the condition to suggest the blanket implementation.
pub(super) fn maybe_lint_blanket_trait_impl<G: EmissionGuarantee>(
fn maybe_suggest_blanket_trait_impl<G: EmissionGuarantee>(
&self,
self_ty: &hir::Ty<'_>,
diag: &mut Diag<'_, G>,
@ -75,7 +150,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
}
/// Make sure that we are in the condition to suggest `impl Trait`.
fn maybe_lint_impl_trait(&self, self_ty: &hir::Ty<'_>, diag: &mut Diag<'_>) -> bool {
fn maybe_suggest_impl_trait(&self, self_ty: &hir::Ty<'_>, diag: &mut Diag<'_>) -> bool {
let tcx = self.tcx();
let parent_id = tcx.hir().get_parent_item(self_ty.hir_id).def_id;
let (sig, generics, owner) = match tcx.hir_node_by_def_id(parent_id) {
@ -185,72 +260,4 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
}
false
}
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_code_err!(tcx.dcx(), self_ty.span, E0782, "{}", msg);
if self_ty.span.can_be_used_for_suggestions()
&& !self.maybe_lint_impl_trait(self_ty, &mut diag)
{
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.node_span_lint(BARE_TRAIT_OBJECTS, self_ty.hir_id, self_ty.span, msg, |lint| {
if self_ty.span.can_be_used_for_suggestions() {
lint.multipart_suggestion_verbose(
"if this is an object-safe trait, use `dyn`",
sugg,
Applicability::MachineApplicable,
);
}
self.maybe_lint_blanket_trait_impl(self_ty, lint);
});
}
}
}
}

4
compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs
View File

@ -2341,12 +2341,12 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
)
}
hir::TyKind::TraitObject(bounds, lifetime, repr) => {
self.maybe_lint_bare_trait(hir_ty, in_path);
self.prohibit_or_lint_bare_trait_object_ty(hir_ty, in_path);
let repr = match repr {
TraitObjectSyntax::Dyn | TraitObjectSyntax::None => ty::Dyn,
TraitObjectSyntax::DynStar => ty::DynStar,
};
self.lower_trait_object_ty(
hir_ty.span,
hir_ty.hir_id,