diff --git a/compiler/rustc_middle/src/middle/stability.rs b/compiler/rustc_middle/src/middle/stability.rs
index 8b11e35a7c3..62e0fec0661 100644
--- a/compiler/rustc_middle/src/middle/stability.rs
+++ b/compiler/rustc_middle/src/middle/stability.rs
@@ -9,10 +9,9 @@ use rustc_attr::{self as attr, ConstStability, Deprecation, Stability};
use rustc_data_structures::fx::FxHashMap;
use rustc_errors::{Applicability, Diagnostic};
use rustc_feature::GateIssue;
-use rustc_hir as hir;
use rustc_hir::def::DefKind;
use rustc_hir::def_id::{DefId, LocalDefId};
-use rustc_hir::{self, HirId};
+use rustc_hir::{self as hir, HirId};
use rustc_middle::ty::print::with_no_trimmed_paths;
use rustc_session::lint::builtin::{DEPRECATED, DEPRECATED_IN_FUTURE, SOFT_UNSTABLE};
use rustc_session::lint::{BuiltinLintDiagnostics, Level, Lint, LintBuffer};
@@ -306,6 +305,14 @@ fn suggestion_for_allocator_api(
None
}
+/// An override option for eval_stability.
+pub enum AllowUnstable {
+ /// Don't emit an unstable error for the item
+ Yes,
+ /// Handle the item normally
+ No,
+}
+
impl<'tcx> TyCtxt<'tcx> {
/// Evaluates the stability of an item.
///
@@ -322,6 +329,28 @@ impl<'tcx> TyCtxt<'tcx> {
id: Option<HirId>,
span: Span,
method_span: Option<Span>,
+ ) -> EvalResult {
+ self.eval_stability_allow_unstable(def_id, id, span, method_span, AllowUnstable::No)
+ }
+
+ /// Evaluates the stability of an item.
+ ///
+ /// Returns `EvalResult::Allow` if the item is stable, or unstable but the corresponding
+ /// `#![feature]` has been provided. Returns `EvalResult::Deny` which describes the offending
+ /// unstable feature otherwise.
+ ///
+ /// If `id` is `Some(_)`, this function will also check if the item at `def_id` has been
+ /// deprecated. If the item is indeed deprecated, we will emit a deprecation lint attached to
+ /// `id`.
+ ///
+ /// Pass `AllowUnstable::Yes` to `allow_unstable` to force an unstable item to be allowed. Deprecation warnings will be emitted normally.
+ pub fn eval_stability_allow_unstable(
+ self,
+ def_id: DefId,
+ id: Option<HirId>,
+ span: Span,
+ method_span: Option<Span>,
+ allow_unstable: AllowUnstable,
) -> EvalResult {
// Deprecated attributes apply in-crate and cross-crate.
if let Some(id) = id {
@@ -419,6 +448,10 @@ impl<'tcx> TyCtxt<'tcx> {
}
}
+ if matches!(allow_unstable, AllowUnstable::Yes) {
+ return EvalResult::Allow;
+ }
+
let suggestion = suggestion_for_allocator_api(self, def_id, span, feature);
EvalResult::Deny { feature, reason, issue, suggestion, is_soft }
}
@@ -445,11 +478,38 @@ impl<'tcx> TyCtxt<'tcx> {
span: Span,
method_span: Option<Span>,
) {
- self.check_optional_stability(def_id, id, span, method_span, |span, def_id| {
- // The API could be uncallable for other reasons, for example when a private module
- // was referenced.
- self.sess.delay_span_bug(span, &format!("encountered unmarked API: {:?}", def_id));
- })
+ self.check_stability_allow_unstable(def_id, id, span, method_span, AllowUnstable::No)
+ }
+
+ /// Checks if an item is stable or error out.
+ ///
+ /// If the item defined by `def_id` is unstable and the corresponding `#![feature]` does not
+ /// exist, emits an error.
+ ///
+ /// This function will also check if the item is deprecated.
+ /// If so, and `id` is not `None`, a deprecated lint attached to `id` will be emitted.
+ ///
+ /// Pass `AllowUnstable::Yes` to `allow_unstable` to force an unstable item to be allowed. Deprecation warnings will be emitted normally.
+ pub fn check_stability_allow_unstable(
+ self,
+ def_id: DefId,
+ id: Option<HirId>,
+ span: Span,
+ method_span: Option<Span>,
+ allow_unstable: AllowUnstable,
+ ) {
+ self.check_optional_stability(
+ def_id,
+ id,
+ span,
+ method_span,
+ allow_unstable,
+ |span, def_id| {
+ // The API could be uncallable for other reasons, for example when a private module
+ // was referenced.
+ self.sess.delay_span_bug(span, &format!("encountered unmarked API: {:?}", def_id));
+ },
+ )
}
/// Like `check_stability`, except that we permit items to have custom behaviour for
@@ -462,6 +522,7 @@ impl<'tcx> TyCtxt<'tcx> {
id: Option<HirId>,
span: Span,
method_span: Option<Span>,
+ allow_unstable: AllowUnstable,
unmarked: impl FnOnce(Span, DefId),
) {
let soft_handler = |lint, span, msg: &_| {
@@ -469,7 +530,7 @@ impl<'tcx> TyCtxt<'tcx> {
lint.build(msg).emit();
})
};
- match self.eval_stability(def_id, id, span, method_span) {
+ match self.eval_stability_allow_unstable(def_id, id, span, method_span, allow_unstable) {
EvalResult::Allow => {}
EvalResult::Deny { feature, reason, issue, suggestion, is_soft } => report_unstable(
self.sess,
diff --git a/compiler/rustc_passes/src/stability.rs b/compiler/rustc_passes/src/stability.rs
index 70cb1f2a281..144a60faad2 100644
--- a/compiler/rustc_passes/src/stability.rs
+++ b/compiler/rustc_passes/src/stability.rs
@@ -9,10 +9,10 @@ use rustc_hir::def::{DefKind, Res};
use rustc_hir::def_id::{LocalDefId, CRATE_DEF_ID};
use rustc_hir::hir_id::CRATE_HIR_ID;
use rustc_hir::intravisit::{self, Visitor};
-use rustc_hir::{FieldDef, Generics, HirId, Item, TraitRef, Ty, TyKind, Variant};
+use rustc_hir::{FieldDef, Generics, HirId, Item, ItemKind, TraitRef, Ty, TyKind, Variant};
use rustc_middle::hir::nested_filter;
use rustc_middle::middle::privacy::AccessLevels;
-use rustc_middle::middle::stability::{DeprecationEntry, Index};
+use rustc_middle::middle::stability::{AllowUnstable, DeprecationEntry, Index};
use rustc_middle::ty::{self, query::Providers, TyCtxt};
use rustc_session::lint;
use rustc_session::lint::builtin::{INEFFECTIVE_UNSTABLE_TRAIT_IMPL, USELESS_DEPRECATED};
@@ -807,12 +807,46 @@ impl<'tcx> Visitor<'tcx> for Checker<'tcx> {
fn visit_path(&mut self, path: &'tcx hir::Path<'tcx>, id: hir::HirId) {
if let Some(def_id) = path.res.opt_def_id() {
let method_span = path.segments.last().map(|s| s.ident.span);
- self.tcx.check_stability(def_id, Some(id), path.span, method_span)
+ self.tcx.check_stability_allow_unstable(
+ def_id,
+ Some(id),
+ path.span,
+ method_span,
+ if is_unstable_reexport(self.tcx, id) {
+ AllowUnstable::Yes
+ } else {
+ AllowUnstable::No
+ },
+ )
}
intravisit::walk_path(self, path)
}
}
+/// Check whether a path is a `use` item that has been marked as unstable.
+///
+/// See issue #94972 for details on why this is a special case
+fn is_unstable_reexport<'tcx>(tcx: TyCtxt<'tcx>, id: hir::HirId) -> bool {
+ // Get the LocalDefId so we can lookup the item to check the kind.
+ let Some(def_id) = tcx.hir().opt_local_def_id(id) else { return false; };
+
+ let Some(stab) = tcx.stability().local_stability(def_id) else {
+ return false;
+ };
+
+ if stab.level.is_stable() {
+ // The re-export is not marked as unstable, don't override
+ return false;
+ }
+
+ // If this is a path that isn't a use, we don't need to do anything special
+ if !matches!(tcx.hir().item(hir::ItemId { def_id }).kind, ItemKind::Use(..)) {
+ return false;
+ }
+
+ true
+}
+
struct CheckTraitImplStable<'tcx> {
tcx: TyCtxt<'tcx>,
fully_stable: bool,
diff --git a/compiler/rustc_typeck/src/astconv/mod.rs b/compiler/rustc_typeck/src/astconv/mod.rs
index bcff2ae5129..b83fdd02da9 100644
--- a/compiler/rustc_typeck/src/astconv/mod.rs
+++ b/compiler/rustc_typeck/src/astconv/mod.rs
@@ -24,6 +24,7 @@ use rustc_hir::def_id::{DefId, LocalDefId};
use rustc_hir::intravisit::{walk_generics, Visitor as _};
use rustc_hir::lang_items::LangItem;
use rustc_hir::{GenericArg, GenericArgs};
+use rustc_middle::middle::stability::AllowUnstable;
use rustc_middle::ty::subst::{self, GenericArgKind, InternalSubsts, Subst, SubstsRef};
use rustc_middle::ty::GenericParamDefKind;
use rustc_middle::ty::{self, Const, DefIdTree, EarlyBinder, Ty, TyCtxt, TypeFoldable};
@@ -426,6 +427,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
Some(arg.id()),
arg.span(),
None,
+ AllowUnstable::No,
|_, _| {
// Default generic parameters may not be marked
// with stability attributes, i.e. when the
diff --git a/src/test/ui/stability-attribute/allow-unstable-reexport.rs b/src/test/ui/stability-attribute/allow-unstable-reexport.rs
new file mode 100644
index 00000000000..937913954a7
--- /dev/null
+++ b/src/test/ui/stability-attribute/allow-unstable-reexport.rs
@@ -0,0 +1,30 @@
+// Allow an unstable re-export without requiring a feature gate.
+// #94972
+
+// aux-build:lint-stability.rs
+// aux-build:lint-stability-reexport.rs
+#![feature(staged_api)]
+#![stable(feature = "lint_stability", since = "1.0.0")]
+
+extern crate lint_stability;
+extern crate lint_stability_reexport;
+
+#[unstable(feature = "unstable_test_feature", issue = "none")]
+pub use lint_stability::unstable;
+
+// We want to confirm that using a re-export through another crate behaves
+// the same way as using an item directly
+#[unstable(feature = "unstable_test_feature", issue = "none")]
+pub use lint_stability_reexport::unstable_text;
+
+// Ensure items which aren't marked as unstable can't re-export unstable items
+#[stable(feature = "lint_stability", since = "1.0.0")]
+pub use lint_stability::unstable as unstable2;
+//~^ ERROR use of unstable library feature 'unstable_test_feature'
+
+fn main() {
+ // Since we didn't enable the feature in this crate, we still can't
+ // use these items, even though they're in scope from the `use`s which are now allowed.
+ unstable(); //~ ERROR use of unstable library feature 'unstable_test_feature'
+ unstable_text(); //~ ERROR use of unstable library feature 'unstable_test_feature'
+}
diff --git a/src/test/ui/stability-attribute/allow-unstable-reexport.stderr b/src/test/ui/stability-attribute/allow-unstable-reexport.stderr
new file mode 100644
index 00000000000..a11da9dc8a7
--- /dev/null
+++ b/src/test/ui/stability-attribute/allow-unstable-reexport.stderr
@@ -0,0 +1,27 @@
+error[E0658]: use of unstable library feature 'unstable_test_feature'
+ --> $DIR/allow-unstable-reexport.rs:22:9
+ |
+LL | pub use lint_stability::unstable as unstable2;
+ | ^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+ = help: add `#![feature(unstable_test_feature)]` to the crate attributes to enable
+
+error[E0658]: use of unstable library feature 'unstable_test_feature'
+ --> $DIR/allow-unstable-reexport.rs:28:5
+ |
+LL | unstable();
+ | ^^^^^^^^
+ |
+ = help: add `#![feature(unstable_test_feature)]` to the crate attributes to enable
+
+error[E0658]: use of unstable library feature 'unstable_test_feature': text
+ --> $DIR/allow-unstable-reexport.rs:29:5
+ |
+LL | unstable_text();
+ | ^^^^^^^^^^^^^
+ |
+ = help: add `#![feature(unstable_test_feature)]` to the crate attributes to enable
+
+error: aborting due to 3 previous errors
+
+For more information about this error, try `rustc --explain E0658`.
diff --git a/src/test/ui/stability-attribute/auxiliary/lint-stability-reexport.rs b/src/test/ui/stability-attribute/auxiliary/lint-stability-reexport.rs
new file mode 100644
index 00000000000..9884731d562
--- /dev/null
+++ b/src/test/ui/stability-attribute/auxiliary/lint-stability-reexport.rs
@@ -0,0 +1,9 @@
+#![crate_type = "lib"]
+#![feature(staged_api)]
+#![stable(feature = "lint_stability", since = "1.0.0")]
+
+extern crate lint_stability;
+
+// Re-exporting without enabling the feature "unstable_test_feature" in this crate
+#[unstable(feature = "unstable_test_feature", issue = "none")]
+pub use lint_stability::unstable_text;