Check for missing const-stability attributes in stability

This used to happen as a side-effect of `is_min_const_fn`, which was
subtle.
This commit is contained in:
Dylan MacKenzie 2020-09-25 13:48:48 -07:00
parent 5bfeee5fe0
commit 61d86fa06c

View File

@ -368,6 +368,21 @@ impl<'tcx> MissingStabilityAnnotations<'tcx> {
self.tcx.sess.span_err(span, &format!("{} has missing stability attribute", descr));
}
}
fn check_missing_const_stability(&self, hir_id: HirId, span: Span) {
let stab_map = self.tcx.stability();
let stab = stab_map.local_stability(hir_id);
if stab.map_or(false, |stab| stab.level.is_stable()) {
let const_stab = stab_map.local_const_stability(hir_id);
if const_stab.is_none() {
self.tcx.sess.span_err(
span,
"`#[stable]` const functions must also be either \
`#[rustc_const_stable]` or `#[rustc_const_unstable]`",
);
}
}
}
}
impl<'tcx> Visitor<'tcx> for MissingStabilityAnnotations<'tcx> {
@ -378,14 +393,23 @@ impl<'tcx> Visitor<'tcx> for MissingStabilityAnnotations<'tcx> {
}
fn visit_item(&mut self, i: &'tcx Item<'tcx>) {
match i.kind {
// Inherent impls and foreign modules serve only as containers for other items,
// they don't have their own stability. They still can be annotated as unstable
// and propagate this unstability to children, but this annotation is completely
// optional. They inherit stability from their parents when unannotated.
hir::ItemKind::Impl { of_trait: None, .. } | hir::ItemKind::ForeignMod(..) => {}
// Inherent impls and foreign modules serve only as containers for other items,
// they don't have their own stability. They still can be annotated as unstable
// and propagate this unstability to children, but this annotation is completely
// optional. They inherit stability from their parents when unannotated.
if !matches!(
i.kind,
hir::ItemKind::Impl { of_trait: None, .. } | hir::ItemKind::ForeignMod(..)
) {
self.check_missing_stability(i.hir_id, i.span);
}
_ => self.check_missing_stability(i.hir_id, i.span),
// Ensure `const fn` that are `stable` have one of `rustc_const_unstable` or
// `rustc_const_stable`.
if self.tcx.features().staged_api
&& matches!(&i.kind, hir::ItemKind::Fn(sig, ..) if sig.header.is_const())
{
self.check_missing_const_stability(i.hir_id, i.span);
}
intravisit::walk_item(self, i)