bjoernager/rust
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Implement elided_named_lifetimes lint

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This commit is contained in:
Pavel Grigorenko 2024-08-15 18:05:59 +03:00
parent 0d634185df
commit 5d04472461
10 changed files with 154 additions and 20 deletions
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79
compiler/rustc_resolve/src/late.rs
View file

@ -1557,14 +1557,14 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
if ident.name == kw::StaticLifetime {
self.record_lifetime_res(
lifetime.id,
LifetimeRes::Static,
LifetimeRes::Static { suppress_elision_warning: false },
LifetimeElisionCandidate::Named,
);
return;
}
if ident.name == kw::UnderscoreLifetime {
return self.resolve_anonymous_lifetime(lifetime, false);
return self.resolve_anonymous_lifetime(lifetime, lifetime.id, false);
}
let mut lifetime_rib_iter = self.lifetime_ribs.iter().rev();
@ -1667,13 +1667,23 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
}
#[instrument(level = "debug", skip(self))]
fn resolve_anonymous_lifetime(&mut self, lifetime: &Lifetime, elided: bool) {
fn resolve_anonymous_lifetime(
&mut self,
lifetime: &Lifetime,
id_for_lint: NodeId,
elided: bool,
) {
debug_assert_eq!(lifetime.ident.name, kw::UnderscoreLifetime);
let kind =
if elided { MissingLifetimeKind::Ampersand } else { MissingLifetimeKind::Underscore };
let missing_lifetime =
MissingLifetime { id: lifetime.id, span: lifetime.ident.span, kind, count: 1 };
let missing_lifetime = MissingLifetime {
id: lifetime.id,
span: lifetime.ident.span,
kind,
count: 1,
id_for_lint,
};
let elision_candidate = LifetimeElisionCandidate::Missing(missing_lifetime);
for (i, rib) in self.lifetime_ribs.iter().enumerate().rev() {
debug!(?rib.kind);
@ -1697,7 +1707,8 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
if lifetimes_in_scope.is_empty() {
self.record_lifetime_res(
lifetime.id,
LifetimeRes::Static,
// We are inside a const item, so do not warn.
LifetimeRes::Static { suppress_elision_warning: true },
elision_candidate,
);
return;
@ -1800,7 +1811,7 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
LifetimeRes::ElidedAnchor { start: id, end: NodeId::from_u32(id.as_u32() + 1) },
LifetimeElisionCandidate::Ignore,
);
self.resolve_anonymous_lifetime(&lt, true);
self.resolve_anonymous_lifetime(&lt, anchor_id, true);
}
#[instrument(level = "debug", skip(self))]
@ -1916,6 +1927,7 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
};
let missing_lifetime = MissingLifetime {
id: node_ids.start,
id_for_lint: segment_id,
span: elided_lifetime_span,
kind,
count: expected_lifetimes,
@ -2039,8 +2051,44 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
if let Some(prev_res) = self.r.lifetimes_res_map.insert(id, res) {
panic!("lifetime {id:?} resolved multiple times ({prev_res:?} before, {res:?} now)")
}
match candidate {
LifetimeElisionCandidate::Missing(missing @ MissingLifetime { .. }) => {
debug_assert_eq!(id, missing.id);
match res {
LifetimeRes::Static { suppress_elision_warning } => {
if !suppress_elision_warning {
self.r.lint_buffer.buffer_lint(
lint::builtin::ELIDED_NAMED_LIFETIMES,
missing.id_for_lint,
missing.span,
BuiltinLintDiag::ElidedIsStatic { elided: missing.span },
);
}
}
LifetimeRes::Param { param, binder: _ } => {
let tcx = self.r.tcx();
self.r.lint_buffer.buffer_lint(
lint::builtin::ELIDED_NAMED_LIFETIMES,
missing.id_for_lint,
missing.span,
BuiltinLintDiag::ElidedIsParam {
elided: missing.span,
param: (tcx.item_name(param.into()), tcx.source_span(param)),
},
);
}
LifetimeRes::Fresh { .. }
| LifetimeRes::Infer
| LifetimeRes::Error
| LifetimeRes::ElidedAnchor { .. } => {}
}
}
LifetimeElisionCandidate::Ignore | LifetimeElisionCandidate::Named => {}
}
match res {
LifetimeRes::Param { .. } | LifetimeRes::Fresh { .. } | LifetimeRes::Static => {
LifetimeRes::Param { .. } | LifetimeRes::Fresh { .. } | LifetimeRes::Static { .. } => {
if let Some(ref mut candidates) = self.lifetime_elision_candidates {
candidates.push((res, candidate));
}
@ -2558,9 +2606,14 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
ItemKind::Static(box ast::StaticItem { ref ty, ref expr, .. }) => {
self.with_static_rib(def_kind, |this| {
this.with_lifetime_rib(LifetimeRibKind::Elided(LifetimeRes::Static), |this| {
this.visit_ty(ty);
});
this.with_lifetime_rib(
LifetimeRibKind::Elided(LifetimeRes::Static {
suppress_elision_warning: true,
}),
|this| {
this.visit_ty(ty);
},
);
if let Some(expr) = expr {
// We already forbid generic params because of the above item rib,
// so it doesn't matter whether this is a trivial constant.
@ -2589,7 +2642,9 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
this.visit_generics(generics);
this.with_lifetime_rib(
LifetimeRibKind::Elided(LifetimeRes::Static),
LifetimeRibKind::Elided(LifetimeRes::Static {
suppress_elision_warning: true,
}),
|this| this.visit_ty(ty),
);

11
compiler/rustc_resolve/src/late/diagnostics.rs
View file

@ -102,6 +102,13 @@ fn import_candidate_to_enum_paths(suggestion: &ImportSuggestion) -> (String, Str
pub(super) struct MissingLifetime {
/// Used to overwrite the resolution with the suggestion, to avoid cascading errors.
pub id: NodeId,
/// As we cannot yet emit lints in this crate and have to buffer them instead,
/// we need to associate each lint with some `NodeId`,
/// however for some `MissingLifetime`s their `NodeId`s are "fake",
/// in a sense that they are temporary and not get preserved down the line,
/// which means that the lints for those nodes will not get emitted.
/// To combat this, we can try to use some other `NodeId`s as a fallback option.
pub id_for_lint: NodeId,
/// Where to suggest adding the lifetime.
pub span: Span,
/// How the lifetime was introduced, to have the correct space and comma.
@ -3028,7 +3035,7 @@ impl<'a: 'ast, 'ast, 'tcx> LateResolutionVisitor<'a, '_, 'ast, 'tcx> {
maybe_static = true;
in_scope_lifetimes = vec![(
Ident::with_dummy_span(kw::StaticLifetime),
(DUMMY_NODE_ID, LifetimeRes::Static),
(DUMMY_NODE_ID, LifetimeRes::Static { suppress_elision_warning: false }),
)];
}
} else if elided_len == 0 {
@ -3040,7 +3047,7 @@ impl<'a: 'ast, 'ast, 'tcx> LateResolutionVisitor<'a, '_, 'ast, 'tcx> {
maybe_static = true;
in_scope_lifetimes = vec![(
Ident::with_dummy_span(kw::StaticLifetime),
(DUMMY_NODE_ID, LifetimeRes::Static),
(DUMMY_NODE_ID, LifetimeRes::Static { suppress_elision_warning: false }),
)];
}
} else if num_params == 1 {