Merging upstream version 1.67.1+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

3 files changed, 152 insertions, 72 deletions

diff --git a/compiler/rustc_middle/src/middle/codegen_fn_attrs.rs b/compiler/rustc_middle/src/middle/codegen_fn_attrs.rs
index 45d33a165..bea884c85 100644
--- a/compiler/rustc_middle/src/middle/codegen_fn_attrs.rs
+++ b/compiler/rustc_middle/src/middle/codegen_fn_attrs.rs
@@ -26,8 +26,10 @@ pub struct CodegenFnAttrs {
     /// The `#[target_feature(enable = "...")]` attribute and the enabled
     /// features (only enabled features are supported right now).
     pub target_features: Vec<Symbol>,
-    /// The `#[linkage = "..."]` attribute and the value we found.
+    /// The `#[linkage = "..."]` attribute on Rust-defined items and the value we found.
     pub linkage: Option<Linkage>,
+    /// The `#[linkage = "..."]` attribute on foreign items and the value we found.
+    pub import_linkage: Option<Linkage>,
     /// The `#[link_section = "..."]` attribute, or what executable section this
     /// should be placed in.
     pub link_section: Option<Symbol>,
@@ -113,6 +115,7 @@ impl CodegenFnAttrs {
             link_ordinal: None,
             target_features: vec![],
             linkage: None,
+            import_linkage: None,
             link_section: None,
             no_sanitize: SanitizerSet::empty(),
             instruction_set: None,
diff --git a/compiler/rustc_middle/src/middle/lang_items.rs b/compiler/rustc_middle/src/middle/lang_items.rs
index 31c20fa14..343ea1f00 100644
--- a/compiler/rustc_middle/src/middle/lang_items.rs
+++ b/compiler/rustc_middle/src/middle/lang_items.rs
@@ -27,7 +27,10 @@ impl<'tcx> TyCtxt<'tcx> {
         })
     }
 
-    pub fn fn_trait_kind_from_lang_item(self, id: DefId) -> Option<ty::ClosureKind> {
+    /// Given a [`DefId`] of a [`Fn`], [`FnMut`] or [`FnOnce`] traits,
+    /// returns a corresponding [`ty::ClosureKind`].
+    /// For any other [`DefId`] return `None`.
+    pub fn fn_trait_kind_from_def_id(self, id: DefId) -> Option<ty::ClosureKind> {
         let items = self.lang_items();
         match Some(id) {
             x if x == items.fn_trait() => Some(ty::ClosureKind::Fn),
@@ -37,8 +40,9 @@ impl<'tcx> TyCtxt<'tcx> {
         }
     }
 
-    pub fn is_weak_lang_item(self, item_def_id: DefId) -> bool {
-        self.lang_items().is_weak_lang_item(item_def_id)
+    /// Returns `true` if `id` is a `DefId` of [`Fn`], [`FnMut`] or [`FnOnce`] traits.
+    pub fn is_fn_trait(self, id: DefId) -> bool {
+        self.fn_trait_kind_from_def_id(id).is_some()
     }
 }
 
diff --git a/compiler/rustc_middle/src/middle/privacy.rs b/compiler/rustc_middle/src/middle/privacy.rs
index 9c68c7504..fc08d58cc 100644
--- a/compiler/rustc_middle/src/middle/privacy.rs
+++ b/compiler/rustc_middle/src/middle/privacy.rs
@@ -1,12 +1,12 @@
 //! A pass that checks to make sure private fields and methods aren't used
 //! outside their scopes. This pass will also generate a set of exported items
 //! which are available for use externally when compiled as a library.
-use crate::ty::{DefIdTree, Visibility};
+use crate::ty::{DefIdTree, TyCtxt, Visibility};
 use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
 use rustc_macros::HashStable;
 use rustc_query_system::ich::StableHashingContext;
-use rustc_span::def_id::{DefId, LocalDefId};
+use rustc_span::def_id::LocalDefId;
 use std::hash::Hash;
 
 /// Represents the levels of effective visibility an item can have.
@@ -75,33 +75,33 @@ impl EffectiveVisibility {
 }
 
 /// Holds a map of effective visibilities for reachable HIR nodes.
-#[derive(Debug, Clone)]
+#[derive(Clone, Debug)]
 pub struct EffectiveVisibilities<Id = LocalDefId> {
     map: FxHashMap<Id, EffectiveVisibility>,
 }
 
-impl<Id: Hash + Eq + Copy> EffectiveVisibilities<Id> {
-    pub fn is_public_at_level(&self, id: Id, level: Level) -> bool {
+impl EffectiveVisibilities {
+    pub fn is_public_at_level(&self, id: LocalDefId, level: Level) -> bool {
         self.effective_vis(id)
             .map_or(false, |effective_vis| effective_vis.is_public_at_level(level))
     }
 
     /// See `Level::Reachable`.
-    pub fn is_reachable(&self, id: Id) -> bool {
+    pub fn is_reachable(&self, id: LocalDefId) -> bool {
         self.is_public_at_level(id, Level::Reachable)
     }
 
     /// See `Level::Reexported`.
-    pub fn is_exported(&self, id: Id) -> bool {
+    pub fn is_exported(&self, id: LocalDefId) -> bool {
         self.is_public_at_level(id, Level::Reexported)
     }
 
     /// See `Level::Direct`.
-    pub fn is_directly_public(&self, id: Id) -> bool {
+    pub fn is_directly_public(&self, id: LocalDefId) -> bool {
         self.is_public_at_level(id, Level::Direct)
     }
 
-    pub fn public_at_level(&self, id: Id) -> Option<Level> {
+    pub fn public_at_level(&self, id: LocalDefId) -> Option<Level> {
         self.effective_vis(id).and_then(|effective_vis| {
             for level in Level::all_levels() {
                 if effective_vis.is_public_at_level(level) {
@@ -112,31 +112,42 @@ impl<Id: Hash + Eq + Copy> EffectiveVisibilities<Id> {
         })
     }
 
-    pub fn effective_vis(&self, id: Id) -> Option<&EffectiveVisibility> {
-        self.map.get(&id)
-    }
-
-    pub fn iter(&self) -> impl Iterator<Item = (&Id, &EffectiveVisibility)> {
-        self.map.iter()
-    }
-
-    pub fn map_id<OutId: Hash + Eq + Copy>(
-        &self,
-        f: impl Fn(Id) -> OutId,
-    ) -> EffectiveVisibilities<OutId> {
-        EffectiveVisibilities { map: self.map.iter().map(|(k, v)| (f(*k), *v)).collect() }
+    // FIXME: Share code with `fn update`.
+    pub fn update_eff_vis(
+        &mut self,
+        def_id: LocalDefId,
+        eff_vis: &EffectiveVisibility,
+        tree: impl DefIdTree,
+    ) {
+        use std::collections::hash_map::Entry;
+        match self.map.entry(def_id) {
+            Entry::Occupied(mut occupied) => {
+                let old_eff_vis = occupied.get_mut();
+                for l in Level::all_levels() {
+                    let vis_at_level = eff_vis.at_level(l);
+                    let old_vis_at_level = old_eff_vis.at_level_mut(l);
+                    if vis_at_level != old_vis_at_level
+                        && vis_at_level.is_at_least(*old_vis_at_level, tree)
+                    {
+                        *old_vis_at_level = *vis_at_level
+                    }
+                }
+                old_eff_vis
+            }
+            Entry::Vacant(vacant) => vacant.insert(*eff_vis),
+        };
     }
 
     pub fn set_public_at_level(
         &mut self,
-        id: Id,
-        default_vis: impl FnOnce() -> Visibility,
+        id: LocalDefId,
+        lazy_private_vis: impl FnOnce() -> Visibility,
         level: Level,
     ) {
         let mut effective_vis = self
             .effective_vis(id)
             .copied()
-            .unwrap_or_else(|| EffectiveVisibility::from_vis(default_vis()));
+            .unwrap_or_else(|| EffectiveVisibility::from_vis(lazy_private_vis()));
         for l in Level::all_levels() {
             if l <= level {
                 *effective_vis.at_level_mut(l) = Visibility::Public;
@@ -144,61 +155,123 @@ impl<Id: Hash + Eq + Copy> EffectiveVisibilities<Id> {
         }
         self.map.insert(id, effective_vis);
     }
+
+    pub fn check_invariants(&self, tcx: TyCtxt<'_>, early: bool) {
+        if !cfg!(debug_assertions) {
+            return;
+        }
+        for (&def_id, ev) in &self.map {
+            // More direct visibility levels can never go farther than less direct ones,
+            // neither of effective visibilities can go farther than nominal visibility,
+            // and all effective visibilities are larger or equal than private visibility.
+            let private_vis = Visibility::Restricted(tcx.parent_module_from_def_id(def_id));
+            let span = tcx.def_span(def_id.to_def_id());
+            if !ev.direct.is_at_least(private_vis, tcx) {
+                span_bug!(span, "private {:?} > direct {:?}", private_vis, ev.direct);
+            }
+            if !ev.reexported.is_at_least(ev.direct, tcx) {
+                span_bug!(span, "direct {:?} > reexported {:?}", ev.direct, ev.reexported);
+            }
+            if !ev.reachable.is_at_least(ev.reexported, tcx) {
+                span_bug!(span, "reexported {:?} > reachable {:?}", ev.reexported, ev.reachable);
+            }
+            if !ev.reachable_through_impl_trait.is_at_least(ev.reachable, tcx) {
+                span_bug!(
+                    span,
+                    "reachable {:?} > reachable_through_impl_trait {:?}",
+                    ev.reachable,
+                    ev.reachable_through_impl_trait
+                );
+            }
+            let nominal_vis = tcx.visibility(def_id);
+            // FIXME: `rustc_privacy` is not yet updated for the new logic and can set
+            // effective visibilities that are larger than the nominal one.
+            if !nominal_vis.is_at_least(ev.reachable_through_impl_trait, tcx) && early {
+                span_bug!(
+                    span,
+                    "{:?}: reachable_through_impl_trait {:?} > nominal {:?}",
+                    def_id,
+                    ev.reachable_through_impl_trait,
+                    nominal_vis
+                );
+            }
+        }
+    }
+}
+
+pub trait IntoDefIdTree {
+    type Tree: DefIdTree;
+    fn tree(self) -> Self::Tree;
 }
 
-impl<Id: Hash + Eq + Copy + Into<DefId>> EffectiveVisibilities<Id> {
-    // `parent_id` is not necessarily a parent in source code tree,
-    // it is the node from which the maximum effective visibility is inherited.
-    pub fn update(
+impl<Id: Eq + Hash> EffectiveVisibilities<Id> {
+    pub fn iter(&self) -> impl Iterator<Item = (&Id, &EffectiveVisibility)> {
+        self.map.iter()
+    }
+
+    pub fn effective_vis(&self, id: Id) -> Option<&EffectiveVisibility> {
+        self.map.get(&id)
+    }
+
+    // FIXME: Share code with `fn update`.
+    pub fn effective_vis_or_private(
+        &mut self,
+        id: Id,
+        lazy_private_vis: impl FnOnce() -> Visibility,
+    ) -> &EffectiveVisibility {
+        self.map.entry(id).or_insert_with(|| EffectiveVisibility::from_vis(lazy_private_vis()))
+    }
+
+    pub fn update<T: IntoDefIdTree>(
         &mut self,
         id: Id,
         nominal_vis: Visibility,
-        default_vis: impl FnOnce() -> Visibility,
-        parent_id: Id,
+        lazy_private_vis: impl FnOnce(T) -> (Visibility, T),
+        inherited_effective_vis: EffectiveVisibility,
         level: Level,
-        tree: impl DefIdTree,
+        mut into_tree: T,
     ) -> bool {
         let mut changed = false;
-        let mut current_effective_vis = self.effective_vis(id).copied().unwrap_or_else(|| {
-            if id.into().is_crate_root() {
-                EffectiveVisibility::from_vis(Visibility::Public)
-            } else {
-                EffectiveVisibility::from_vis(default_vis())
+        let mut current_effective_vis = match self.map.get(&id).copied() {
+            Some(eff_vis) => eff_vis,
+            None => {
+                let private_vis;
+                (private_vis, into_tree) = lazy_private_vis(into_tree);
+                EffectiveVisibility::from_vis(private_vis)
             }
-        });
-        if let Some(inherited_effective_vis) = self.effective_vis(parent_id) {
-            let mut inherited_effective_vis_at_prev_level =
-                *inherited_effective_vis.at_level(level);
-            let mut calculated_effective_vis = inherited_effective_vis_at_prev_level;
-            for l in Level::all_levels() {
-                if level >= l {
-                    let inherited_effective_vis_at_level = *inherited_effective_vis.at_level(l);
-                    let current_effective_vis_at_level = current_effective_vis.at_level_mut(l);
-                    // effective visibility for id shouldn't be recalculated if
-                    // inherited from parent_id effective visibility isn't changed at next level
-                    if !(inherited_effective_vis_at_prev_level == inherited_effective_vis_at_level
-                        && level != l)
-                    {
-                        calculated_effective_vis =
-                            if nominal_vis.is_at_least(inherited_effective_vis_at_level, tree) {
-                                inherited_effective_vis_at_level
-                            } else {
-                                nominal_vis
-                            };
-                    }
-                    // effective visibility can't be decreased at next update call for the
-                    // same id
-                    if *current_effective_vis_at_level != calculated_effective_vis
-                        && calculated_effective_vis
-                            .is_at_least(*current_effective_vis_at_level, tree)
-                    {
-                        changed = true;
-                        *current_effective_vis_at_level = calculated_effective_vis;
-                    }
-                    inherited_effective_vis_at_prev_level = inherited_effective_vis_at_level;
+        };
+        let tree = into_tree.tree();
+
+        let mut inherited_effective_vis_at_prev_level = *inherited_effective_vis.at_level(level);
+        let mut calculated_effective_vis = inherited_effective_vis_at_prev_level;
+        for l in Level::all_levels() {
+            if level >= l {
+                let inherited_effective_vis_at_level = *inherited_effective_vis.at_level(l);
+                let current_effective_vis_at_level = current_effective_vis.at_level_mut(l);
+                // effective visibility for id shouldn't be recalculated if
+                // inherited from parent_id effective visibility isn't changed at next level
+                if !(inherited_effective_vis_at_prev_level == inherited_effective_vis_at_level
+                    && level != l)
+                {
+                    calculated_effective_vis =
+                        if nominal_vis.is_at_least(inherited_effective_vis_at_level, tree) {
+                            inherited_effective_vis_at_level
+                        } else {
+                            nominal_vis
+                        };
+                }
+                // effective visibility can't be decreased at next update call for the
+                // same id
+                if *current_effective_vis_at_level != calculated_effective_vis
+                    && calculated_effective_vis.is_at_least(*current_effective_vis_at_level, tree)
+                {
+                    changed = true;
+                    *current_effective_vis_at_level = calculated_effective_vis;
                 }
+                inherited_effective_vis_at_prev_level = inherited_effective_vis_at_level;
             }
         }
+
         self.map.insert(id, current_effective_vis);
         changed
     }