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Rollup merge of #106064 - lukas-code:outlives-macro, r=cjgillot

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Partially fix `explicit_outlives_requirements` lint in macros

Show the suggestion if and only if the bounds are from the same source context.

fixes https://github.com/rust-lang/rust/issues/106044
fixes https://github.com/rust-lang/rust/issues/106063
This commit is contained in:
Michael Goulet 2022-12-27 12:33:35 -08:00 • committed by GitHub
commit 18bf19c3a9
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GPG key ID: 4AEE18F83AFDEB23
7 changed files with 458 additions and 88 deletions
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148
compiler/rustc_lint/src/builtin.rs
View file

@ -2184,6 +2184,7 @@ impl ExplicitOutlivesRequirements {
tcx: TyCtxt<'tcx>,
bounds: &hir::GenericBounds<'_>,
inferred_outlives: &[ty::Region<'tcx>],
predicate_span: Span,
) -> Vec<(usize, Span)> {
use rustc_middle::middle::resolve_lifetime::Region;
@ -2191,23 +2192,28 @@ impl ExplicitOutlivesRequirements {
.iter()
.enumerate()
.filter_map(|(i, bound)| {
if let hir::GenericBound::Outlives(lifetime) = bound {
let is_inferred = match tcx.named_region(lifetime.hir_id) {
Some(Region::EarlyBound(def_id)) => inferred_outlives.iter().any(|r| {
if let ty::ReEarlyBound(ebr) = **r {
ebr.def_id == def_id
} else {
false
}
}),
_ => false,
};
is_inferred.then_some((i, bound.span()))
} else {
None
let hir::GenericBound::Outlives(lifetime) = bound else {
return None;
};
let is_inferred = match tcx.named_region(lifetime.hir_id) {
Some(Region::EarlyBound(def_id)) => inferred_outlives
.iter()
.any(|r| matches!(**r, ty::ReEarlyBound(ebr) if { ebr.def_id == def_id })),
_ => false,
};
if !is_inferred {
return None;
}
let span = bound.span().find_ancestor_inside(predicate_span)?;
if in_external_macro(tcx.sess, span) {
return None;
}
Some((i, span))
})
.filter(|(_, span)| !in_external_macro(tcx.sess, *span))
.collect()
}
@ -2273,9 +2279,9 @@ impl<'tcx> LateLintPass<'tcx> for ExplicitOutlivesRequirements {
use rustc_middle::middle::resolve_lifetime::Region;
let def_id = item.owner_id.def_id;
if let hir::ItemKind::Struct(_, ref hir_generics)
| hir::ItemKind::Enum(_, ref hir_generics)
| hir::ItemKind::Union(_, ref hir_generics) = item.kind
if let hir::ItemKind::Struct(_, hir_generics)
| hir::ItemKind::Enum(_, hir_generics)
| hir::ItemKind::Union(_, hir_generics) = item.kind
{
let inferred_outlives = cx.tcx.inferred_outlives_of(def_id);
if inferred_outlives.is_empty() {
@ -2290,53 +2296,58 @@ impl<'tcx> LateLintPass<'tcx> for ExplicitOutlivesRequirements {
let mut dropped_predicate_count = 0;
let num_predicates = hir_generics.predicates.len();
for (i, where_predicate) in hir_generics.predicates.iter().enumerate() {
let (relevant_lifetimes, bounds, span, in_where_clause) = match where_predicate {
hir::WherePredicate::RegionPredicate(predicate) => {
if let Some(Region::EarlyBound(region_def_id)) =
cx.tcx.named_region(predicate.lifetime.hir_id)
{
(
Self::lifetimes_outliving_lifetime(
inferred_outlives,
region_def_id,
),
&predicate.bounds,
predicate.span,
predicate.in_where_clause,
)
} else {
continue;
}
}
hir::WherePredicate::BoundPredicate(predicate) => {
// FIXME we can also infer bounds on associated types,
// and should check for them here.
match predicate.bounded_ty.kind {
hir::TyKind::Path(hir::QPath::Resolved(None, ref path)) => {
let Res::Def(DefKind::TyParam, def_id) = path.res else {
continue
};
let index = ty_generics.param_def_id_to_index[&def_id];
let (relevant_lifetimes, bounds, predicate_span, in_where_clause) =
match where_predicate {
hir::WherePredicate::RegionPredicate(predicate) => {
if let Some(Region::EarlyBound(region_def_id)) =
cx.tcx.named_region(predicate.lifetime.hir_id)
{
(
Self::lifetimes_outliving_type(inferred_outlives, index),
Self::lifetimes_outliving_lifetime(
inferred_outlives,
region_def_id,
),
&predicate.bounds,
predicate.span,
predicate.origin == PredicateOrigin::WhereClause,
predicate.in_where_clause,
)
}
_ => {
} else {
continue;
}
}
}
_ => continue,
};
hir::WherePredicate::BoundPredicate(predicate) => {
// FIXME we can also infer bounds on associated types,
// and should check for them here.
match predicate.bounded_ty.kind {
hir::TyKind::Path(hir::QPath::Resolved(None, path)) => {
let Res::Def(DefKind::TyParam, def_id) = path.res else {
continue;
};
let index = ty_generics.param_def_id_to_index[&def_id];
(
Self::lifetimes_outliving_type(inferred_outlives, index),
&predicate.bounds,
predicate.span,
predicate.origin == PredicateOrigin::WhereClause,
)
}
_ => {
continue;
}
}
}
_ => continue,
};
if relevant_lifetimes.is_empty() {
continue;
}
let bound_spans =
self.collect_outlives_bound_spans(cx.tcx, bounds, &relevant_lifetimes);
let bound_spans = self.collect_outlives_bound_spans(
cx.tcx,
bounds,
&relevant_lifetimes,
predicate_span,
);
bound_count += bound_spans.len();
let drop_predicate = bound_spans.len() == bounds.len();
@ -2345,15 +2356,15 @@ impl<'tcx> LateLintPass<'tcx> for ExplicitOutlivesRequirements {
}
if drop_predicate && !in_where_clause {
lint_spans.push(span);
lint_spans.push(predicate_span);
} else if drop_predicate && i + 1 < num_predicates {
// If all the bounds on a predicate were inferable and there are
// further predicates, we want to eat the trailing comma.
let next_predicate_span = hir_generics.predicates[i + 1].span();
where_lint_spans.push(span.to(next_predicate_span.shrink_to_lo()));
where_lint_spans.push(predicate_span.to(next_predicate_span.shrink_to_lo()));
} else {
where_lint_spans.extend(self.consolidate_outlives_bound_spans(
span.shrink_to_lo(),
predicate_span.shrink_to_lo(),
bounds,
bound_spans,
));
@ -2374,12 +2385,26 @@ impl<'tcx> LateLintPass<'tcx> for ExplicitOutlivesRequirements {
} else {
hir_generics.span.shrink_to_hi().to(where_span)
};
lint_spans.push(full_where_span);
// Due to macro expansions, the `full_where_span` might not actually contain all predicates.
if where_lint_spans.iter().all(|&sp| full_where_span.contains(sp)) {
lint_spans.push(full_where_span);
} else {
lint_spans.extend(where_lint_spans);
}
} else {
lint_spans.extend(where_lint_spans);
}
if !lint_spans.is_empty() {
// Do not automatically delete outlives requirements from macros.
let applicability = if lint_spans.iter().all(|sp| sp.can_be_used_for_suggestions())
{
Applicability::MachineApplicable
} else {
Applicability::MaybeIncorrect
};
cx.struct_span_lint(
EXPLICIT_OUTLIVES_REQUIREMENTS,
lint_spans.clone(),
@ -2387,11 +2412,8 @@ impl<'tcx> LateLintPass<'tcx> for ExplicitOutlivesRequirements {
|lint| {
lint.set_arg("count", bound_count).multipart_suggestion(
fluent::suggestion,
lint_spans
.into_iter()
.map(|span| (span, String::new()))
.collect::<Vec<_>>(),
Applicability::MachineApplicable,
lint_spans.into_iter().map(|span| (span, String::new())).collect(),
applicability,
)
},
);