Integrate stable feature checking into a query.

Author: cjgillot

compiler/rustc_interface/src/passes.rs

@@ -1054,11 +1054,6 @@ fn run_required_analyses(tcx: TyCtxt<'_>) {
                     tcx.ensure_ok().check_mod_unstable_api_usage(module);
                 });
             },
-            {
-                sess.time("unused_lib_feature_checking", || {
-                    rustc_passes::stability::check_unused_or_stable_features(tcx)
-                });
-            },
             {
                 // We force these queries to run,
                 // since they might not otherwise get called.

compiler/rustc_passes/src/stability.rs

@@ -13,7 +13,6 @@ use rustc_data_structures::unord::{ExtendUnord, UnordMap, UnordSet};
 use rustc_feature::{EnabledLangFeature, EnabledLibFeature};
 use rustc_hir::def::{DefKind, Res};
 use rustc_hir::def_id::{CRATE_DEF_ID, LOCAL_CRATE, LocalDefId, LocalModDefId};
-use rustc_hir::hir_id::CRATE_HIR_ID;
 use rustc_hir::intravisit::{self, Visitor, VisitorExt};
 use rustc_hir::{self as hir, AmbigArg, FieldDef, Item, ItemKind, TraitRef, Ty, TyKind, Variant};
 use rustc_middle::hir::nested_filter;
@@ -411,7 +410,7 @@ struct MissingStabilityAnnotations<'tcx> {
 impl<'tcx> MissingStabilityAnnotations<'tcx> {
     /// Verify that deprecation and stability attributes make sense with one another.
     #[instrument(level = "trace", skip(self))]
-    fn check_compatible_stability(&self, def_id: LocalDefId, item_sp: Span) {
+    fn check_compatible_stability(&self, def_id: LocalDefId) {
         if !self.tcx.features().staged_api() {
             return;
         }
@@ -441,6 +440,7 @@ impl<'tcx> MissingStabilityAnnotations<'tcx> {
                 || (kind == AnnotationKind::Container && stab.level.is_stable() && depr.is_some())
             {
                 if let Some(span) = find_attr_span!(Stability) {
+                    let item_sp = self.tcx.def_span(def_id);
                     self.tcx.dcx().emit_err(errors::UselessStability { span, item_sp });
                 }
             }
@@ -452,6 +452,7 @@ impl<'tcx> MissingStabilityAnnotations<'tcx> {
                 && let attrs::StabilityLevel::Stable { since: stab_since, .. } = stab.level
                 && let Some(span) = find_attr_span!(Stability)
             {
+                let item_sp = self.tcx.def_span(def_id);
                 match stab_since {
                     StableSince::Current => {
                         self.tcx
@@ -506,19 +507,20 @@ impl<'tcx> MissingStabilityAnnotations<'tcx> {
     }
 
     #[instrument(level = "debug", skip(self))]
-    fn check_missing_stability(&self, def_id: LocalDefId, span: Span) {
+    fn check_missing_stability(&self, def_id: LocalDefId) {
         let stab = self.tcx.lookup_stability(def_id);
         self.tcx.ensure_ok().lookup_const_stability(def_id);
         if !self.tcx.sess.is_test_crate()
             && stab.is_none()
             && self.effective_visibilities.is_reachable(def_id)
         {
             let descr = self.tcx.def_descr(def_id.to_def_id());
+            let span = self.tcx.def_span(def_id);
             self.tcx.dcx().emit_err(errors::MissingStabilityAttr { span, descr });
         }
     }
 
-    fn check_missing_const_stability(&self, def_id: LocalDefId, span: Span) {
+    fn check_missing_const_stability(&self, def_id: LocalDefId) {
         let is_const = self.tcx.is_const_fn(def_id.to_def_id())
             || (self.tcx.def_kind(def_id.to_def_id()) == DefKind::Trait
                 && self.tcx.is_const_trait(def_id.to_def_id()));
@@ -528,6 +530,7 @@ impl<'tcx> MissingStabilityAnnotations<'tcx> {
             && self.effective_visibilities.is_reachable(def_id)
             && self.tcx.lookup_const_stability(def_id).is_none()
         {
+            let span = self.tcx.def_span(def_id);
             let descr = self.tcx.def_descr(def_id.to_def_id());
             self.tcx.dcx().emit_err(errors::MissingConstStabAttr { span, descr });
         }
@@ -542,7 +545,7 @@ impl<'tcx> Visitor<'tcx> for MissingStabilityAnnotations<'tcx> {
     }
 
     fn visit_item(&mut self, i: &'tcx Item<'tcx>) {
-        self.check_compatible_stability(i.owner_id.def_id, i.span);
+        self.check_compatible_stability(i.owner_id.def_id);
 
         // 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
@@ -553,54 +556,54 @@ impl<'tcx> Visitor<'tcx> for MissingStabilityAnnotations<'tcx> {
             hir::ItemKind::Impl(hir::Impl { of_trait: None, .. })
                 | hir::ItemKind::ForeignMod { .. }
         ) {
-            self.check_missing_stability(i.owner_id.def_id, i.span);
+            self.check_missing_stability(i.owner_id.def_id);
         }
 
         // Ensure stable `const fn` have a const stability attribute.
-        self.check_missing_const_stability(i.owner_id.def_id, i.span);
+        self.check_missing_const_stability(i.owner_id.def_id);
 
         intravisit::walk_item(self, i)
     }
 
     fn visit_trait_item(&mut self, ti: &'tcx hir::TraitItem<'tcx>) {
-        self.check_compatible_stability(ti.owner_id.def_id, ti.span);
-        self.check_missing_stability(ti.owner_id.def_id, ti.span);
+        self.check_compatible_stability(ti.owner_id.def_id);
+        self.check_missing_stability(ti.owner_id.def_id);
         intravisit::walk_trait_item(self, ti);
     }
 
     fn visit_impl_item(&mut self, ii: &'tcx hir::ImplItem<'tcx>) {
-        self.check_compatible_stability(ii.owner_id.def_id, ii.span);
+        self.check_compatible_stability(ii.owner_id.def_id);
         let impl_def_id = self.tcx.hir_get_parent_item(ii.hir_id());
         if self.tcx.impl_trait_ref(impl_def_id).is_none() {
-            self.check_missing_stability(ii.owner_id.def_id, ii.span);
-            self.check_missing_const_stability(ii.owner_id.def_id, ii.span);
+            self.check_missing_stability(ii.owner_id.def_id);
+            self.check_missing_const_stability(ii.owner_id.def_id);
         }
         intravisit::walk_impl_item(self, ii);
     }
 
     fn visit_variant(&mut self, var: &'tcx Variant<'tcx>) {
-        self.check_compatible_stability(var.def_id, var.span);
-        self.check_missing_stability(var.def_id, var.span);
+        self.check_compatible_stability(var.def_id);
+        self.check_missing_stability(var.def_id);
         if let Some(ctor_def_id) = var.data.ctor_def_id() {
-            self.check_missing_stability(ctor_def_id, var.span);
+            self.check_missing_stability(ctor_def_id);
         }
         intravisit::walk_variant(self, var);
     }
 
     fn visit_field_def(&mut self, s: &'tcx FieldDef<'tcx>) {
-        self.check_compatible_stability(s.def_id, s.span);
-        self.check_missing_stability(s.def_id, s.span);
+        self.check_compatible_stability(s.def_id);
+        self.check_missing_stability(s.def_id);
         intravisit::walk_field_def(self, s);
     }
 
     fn visit_foreign_item(&mut self, i: &'tcx hir::ForeignItem<'tcx>) {
-        self.check_compatible_stability(i.owner_id.def_id, i.span);
-        self.check_missing_stability(i.owner_id.def_id, i.span);
+        self.check_compatible_stability(i.owner_id.def_id);
+        self.check_missing_stability(i.owner_id.def_id);
         intravisit::walk_foreign_item(self, i);
     }
 
     fn visit_generic_param(&mut self, p: &'tcx hir::GenericParam<'tcx>) {
-        self.check_compatible_stability(p.def_id, p.span);
+        self.check_compatible_stability(p.def_id);
         // Note that we don't need to `check_missing_stability` for default generic parameters,
         // as we assume that any default generic parameters without attributes are automatically
         // stable (assuming they have not inherited instability from their parent).
@@ -619,6 +622,21 @@ fn stability_implications(tcx: TyCtxt<'_>, LocalCrate: LocalCrate) -> UnordMap<S
 /// features and possibly prints errors.
 fn check_mod_unstable_api_usage(tcx: TyCtxt<'_>, module_def_id: LocalModDefId) {
     tcx.hir_visit_item_likes_in_module(module_def_id, &mut Checker { tcx });
+
+    let is_staged_api =
+        tcx.sess.opts.unstable_opts.force_unstable_if_unmarked || tcx.features().staged_api();
+    if is_staged_api {
+        let effective_visibilities = &tcx.effective_visibilities(());
+        let mut missing = MissingStabilityAnnotations { tcx, effective_visibilities };
+        if module_def_id.is_top_level_module() {
+            missing.check_missing_stability(CRATE_DEF_ID);
+        }
+        tcx.hir_visit_item_likes_in_module(module_def_id, &mut missing);
+    }
+
+    if module_def_id.is_top_level_module() {
+        check_unused_or_stable_features(tcx)
+    }
 }
 
 pub(crate) fn provide(providers: &mut Providers) {
@@ -974,16 +992,9 @@ impl<'tcx> Visitor<'tcx> for CheckTraitImplStable<'tcx> {
 /// Given the list of enabled features that were not language features (i.e., that
 /// were expected to be library features), and the list of features used from
 /// libraries, identify activated features that don't exist and error about them.
+// This is `pub` for rustdoc. rustc should call it through `check_mod_unstable_api_usage`.
 pub fn check_unused_or_stable_features(tcx: TyCtxt<'_>) {
-    let is_staged_api =
-        tcx.sess.opts.unstable_opts.force_unstable_if_unmarked || tcx.features().staged_api();
-    if is_staged_api {
-        let effective_visibilities = &tcx.effective_visibilities(());
-        let mut missing = MissingStabilityAnnotations { tcx, effective_visibilities };
-        missing.check_missing_stability(CRATE_DEF_ID, tcx.hir_span(CRATE_HIR_ID));
-        tcx.hir_walk_toplevel_module(&mut missing);
-        tcx.hir_visit_all_item_likes_in_crate(&mut missing);
-    }
+    let _prof_timer = tcx.sess.timer("unused_lib_feature_checking");
 
     let enabled_lang_features = tcx.features().enabled_lang_features();
     let mut lang_features = UnordSet::default();

tests/ui/feature-gates/issue-43106-gating-of-builtin-attrs.stderr

@@ -417,6 +417,14 @@ LL | #![cold]
    |
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
 
+warning: the feature `rust1` has been stable since 1.0.0 and no longer requires an attribute to enable
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:85:12
+   |
+LL | #![feature(rust1)]
+   |            ^^^^^
+   |
+   = note: `#[warn(stable_features)]` on by default
+
 warning: `#[macro_use]` only has an effect on `extern crate` and modules
   --> $DIR/issue-43106-gating-of-builtin-attrs.rs:176:5
    |
@@ -1161,13 +1169,5 @@ warning: crate-level attribute should be an inner attribute: add an exclamation
 LL |     #[type_length_limit="0100"] impl S { }
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-warning: the feature `rust1` has been stable since 1.0.0 and no longer requires an attribute to enable
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:85:12
-   |
-LL | #![feature(rust1)]
-   |            ^^^^^
-   |
-   = note: `#[warn(stable_features)]` on by default
-
 warning: 173 warnings emitted
 

tests/ui/lint/lint-stability-deprecated.stderr

@@ -1,15 +1,21 @@
-warning: use of deprecated function `lint_stability::deprecated`: text
-  --> $DIR/lint-stability-deprecated.rs:24:9
+warning: use of deprecated associated type `lint_stability::TraitWithAssociatedTypes::TypeDeprecated`: text
+  --> $DIR/lint-stability-deprecated.rs:97:48
    |
-LL |         deprecated();
-   |         ^^^^^^^^^^
+LL |         struct S2<T: TraitWithAssociatedTypes>(T::TypeDeprecated);
+   |                                                ^^^^^^^^^^^^^^^^^
    |
 note: the lint level is defined here
   --> $DIR/lint-stability-deprecated.rs:6:9
    |
 LL | #![warn(deprecated)]
    |         ^^^^^^^^^^
 
+warning: use of deprecated function `lint_stability::deprecated`: text
+  --> $DIR/lint-stability-deprecated.rs:24:9
+   |
+LL |         deprecated();
+   |         ^^^^^^^^^^
+
 warning: use of deprecated method `lint_stability::Trait::trait_deprecated`: text
   --> $DIR/lint-stability-deprecated.rs:29:16
    |
@@ -316,12 +322,6 @@ warning: use of deprecated function `this_crate::MethodTester::test_method_body:
 LL |             fn_in_body();
    |             ^^^^^^^^^^
 
-warning: use of deprecated associated type `lint_stability::TraitWithAssociatedTypes::TypeDeprecated`: text
-  --> $DIR/lint-stability-deprecated.rs:97:48
-   |
-LL |         struct S2<T: TraitWithAssociatedTypes>(T::TypeDeprecated);
-   |                                                ^^^^^^^^^^^^^^^^^
-
 warning: use of deprecated associated type `lint_stability::TraitWithAssociatedTypes::TypeDeprecated`: text
   --> $DIR/lint-stability-deprecated.rs:101:13
    |

tests/ui/lint/lint-stability.stderr

@@ -1,3 +1,12 @@
+error[E0658]: use of unstable library feature `unstable_test_feature`
+  --> $DIR/lint-stability.rs:88:48
+   |
+LL |         struct S1<T: TraitWithAssociatedTypes>(T::TypeUnstable);
+   |                                                ^^^^^^^^^^^^^^^
+   |
+   = help: add `#![feature(unstable_test_feature)]` to the crate attributes to enable
+   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
+
 error[E0658]: use of unstable library feature `unstable_test_feature`
   --> $DIR/lint-stability.rs:17:5
    |
@@ -367,15 +376,6 @@ LL |         let _ = Unstable::StableVariant;
    = help: add `#![feature(unstable_test_feature)]` to the crate attributes to enable
    = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
 
-error[E0658]: use of unstable library feature `unstable_test_feature`
-  --> $DIR/lint-stability.rs:88:48
-   |
-LL |         struct S1<T: TraitWithAssociatedTypes>(T::TypeUnstable);
-   |                                                ^^^^^^^^^^^^^^^
-   |
-   = help: add `#![feature(unstable_test_feature)]` to the crate attributes to enable
-   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
-
 error[E0658]: use of unstable library feature `unstable_test_feature`
   --> $DIR/lint-stability.rs:92:13
    |

tests/ui/missing/missing-stability.stderr

@@ -1,17 +1,14 @@
 error: function has missing stability attribute
   --> $DIR/missing-stability.rs:8:1
    |
-LL | / pub fn unmarked() {
-LL | |
-LL | |     ()
-LL | | }
-   | |_^
+LL | pub fn unmarked() {
+   | ^^^^^^^^^^^^^^^^^
 
 error: function has missing stability attribute
   --> $DIR/missing-stability.rs:22:5
    |
 LL |     pub fn unmarked() {}
-   |     ^^^^^^^^^^^^^^^^^^^^
+   |     ^^^^^^^^^^^^^^^^^
 
 error: aborting due to 2 previous errors
 

tests/ui/privacy/effective_visibilities_invariants.stderr

@@ -23,7 +23,7 @@ error: module has missing stability attribute
   --> $DIR/effective_visibilities_invariants.rs:5:1
    |
 LL | pub mod m {}
-   | ^^^^^^^^^^^^
+   | ^^^^^^^^^
 
 error: aborting due to 3 previous errors
 

tests/ui/privacy/issue-113860-1.stderr

@@ -20,28 +20,20 @@ LL | | fn main() {}
 error: trait has missing stability attribute
   --> $DIR/issue-113860-1.rs:4:1
    |
-LL | / pub trait Trait {
-LL | |
-LL | |     fn fun() {}
-LL | |
-LL | | }
-   | |_^
+LL | pub trait Trait {
+   | ^^^^^^^^^^^^^^^
 
 error: implementation has missing stability attribute
   --> $DIR/issue-113860-1.rs:10:1
    |
-LL | / impl Trait for u8 {
-LL | |
-LL | |     pub(self) fn fun() {}
-LL | |
-LL | | }
-   | |_^
+LL | impl Trait for u8 {
+   | ^^^^^^^^^^^^^^^^^
 
 error: associated function has missing stability attribute
   --> $DIR/issue-113860-1.rs:6:5
    |
 LL |     fn fun() {}
-   |     ^^^^^^^^^^^
+   |     ^^^^^^^^
 
 error: aborting due to 5 previous errors
 

tests/ui/privacy/issue-113860-2.stderr

@@ -20,28 +20,20 @@ LL | | fn main() {}
 error: trait has missing stability attribute
   --> $DIR/issue-113860-2.rs:4:1
    |
-LL | / pub trait Trait {
-LL | |
-LL | |     type X;
-LL | |
-LL | | }
-   | |_^
+LL | pub trait Trait {
+   | ^^^^^^^^^^^^^^^
 
 error: implementation has missing stability attribute
   --> $DIR/issue-113860-2.rs:10:1
    |
-LL | / impl Trait for u8 {
-LL | |
-LL | |     pub(self) type X = Self;
-LL | |
-LL | | }
-   | |_^
+LL | impl Trait for u8 {
+   | ^^^^^^^^^^^^^^^^^
 
 error: associated type has missing stability attribute
   --> $DIR/issue-113860-2.rs:6:5
    |
 LL |     type X;
-   |     ^^^^^^^
+   |     ^^^^^^
 
 error: aborting due to 5 previous errors