Auto merge of #102233 - petrochenkov:effvis, r=jackh726

privacy: Rename "accessibility levels" to "effective visibilities"

And a couple of other naming and comment tweaks.

Related to #48054

For `enum Level` I initially used naming `enum EffectiveVisibilityLevel`, but it was too long and inconvenient because it's used pretty often.
So I shortened it to just `Level`, if it needs to be used from some context where this name would be ambiguous, then it can be imported with renaming like `use rustc_middle::privacy::Level as EffVisLevel` or something.

compiler/rustc_interface/src/passes.rs

@@ -927,7 +927,7 @@ fn analysis(tcx: TyCtxt<'_>, (): ()) -> Result<()> {
     sess.time("misc_checking_3", || {
         parallel!(
             {
-                tcx.ensure().privacy_access_levels(());
+                tcx.ensure().effective_visibilities(());
 
                 parallel!(
                     {

compiler/rustc_lint/src/builtin.rs

@@ -563,7 +563,7 @@ impl MissingDoc {
         // It's an option so the crate root can also use this function (it doesn't
         // have a `NodeId`).
         if def_id != CRATE_DEF_ID {
-            if !cx.access_levels.is_exported(def_id) {
+            if !cx.effective_visibilities.is_exported(def_id) {
                 return;
             }
         }
@@ -721,7 +721,7 @@ declare_lint_pass!(MissingCopyImplementations => [MISSING_COPY_IMPLEMENTATIONS])
 
 impl<'tcx> LateLintPass<'tcx> for MissingCopyImplementations {
     fn check_item(&mut self, cx: &LateContext<'_>, item: &hir::Item<'_>) {
-        if !cx.access_levels.is_reachable(item.def_id.def_id) {
+        if !cx.effective_visibilities.is_reachable(item.def_id.def_id) {
             return;
         }
         let (def, ty) = match item.kind {
@@ -814,7 +814,7 @@ impl_lint_pass!(MissingDebugImplementations => [MISSING_DEBUG_IMPLEMENTATIONS]);
 
 impl<'tcx> LateLintPass<'tcx> for MissingDebugImplementations {
     fn check_item(&mut self, cx: &LateContext<'_>, item: &hir::Item<'_>) {
-        if !cx.access_levels.is_reachable(item.def_id.def_id) {
+        if !cx.effective_visibilities.is_reachable(item.def_id.def_id) {
             return;
         }
 
@@ -1385,7 +1385,8 @@ impl UnreachablePub {
         exportable: bool,
     ) {
         let mut applicability = Applicability::MachineApplicable;
-        if cx.tcx.visibility(def_id).is_public() && !cx.access_levels.is_reachable(def_id) {
+        if cx.tcx.visibility(def_id).is_public() && !cx.effective_visibilities.is_reachable(def_id)
+        {
             if vis_span.from_expansion() {
                 applicability = Applicability::MaybeIncorrect;
             }

compiler/rustc_lint/src/context.rs

@@ -31,7 +31,7 @@ use rustc_hir as hir;
 use rustc_hir::def::Res;
 use rustc_hir::def_id::{CrateNum, DefId};
 use rustc_hir::definitions::{DefPathData, DisambiguatedDefPathData};
-use rustc_middle::middle::privacy::AccessLevels;
+use rustc_middle::middle::privacy::EffectiveVisibilities;
 use rustc_middle::middle::stability;
 use rustc_middle::ty::layout::{LayoutError, LayoutOfHelpers, TyAndLayout};
 use rustc_middle::ty::print::with_no_trimmed_paths;
@@ -542,7 +542,7 @@ pub struct LateContext<'tcx> {
     pub param_env: ty::ParamEnv<'tcx>,
 
     /// Items accessible from the crate being checked.
-    pub access_levels: &'tcx AccessLevels,
+    pub effective_visibilities: &'tcx EffectiveVisibilities,
 
     /// The store of registered lints and the lint levels.
     pub lint_store: &'tcx LintStore,

compiler/rustc_lint/src/late.rs

@@ -338,14 +338,14 @@ fn late_lint_mod_pass<'tcx, T: LateLintPass<'tcx>>(
     module_def_id: LocalDefId,
     pass: T,
 ) {
-    let access_levels = &tcx.privacy_access_levels(());
+    let effective_visibilities = &tcx.effective_visibilities(());
 
     let context = LateContext {
         tcx,
         enclosing_body: None,
         cached_typeck_results: Cell::new(None),
         param_env: ty::ParamEnv::empty(),
-        access_levels,
+        effective_visibilities,
         lint_store: unerased_lint_store(tcx),
         last_node_with_lint_attrs: tcx.hir().local_def_id_to_hir_id(module_def_id),
         generics: None,
@@ -386,14 +386,14 @@ pub fn late_lint_mod<'tcx, T: LateLintPass<'tcx>>(
 }
 
 fn late_lint_pass_crate<'tcx, T: LateLintPass<'tcx>>(tcx: TyCtxt<'tcx>, pass: T) {
-    let access_levels = &tcx.privacy_access_levels(());
+    let effective_visibilities = &tcx.effective_visibilities(());
 
     let context = LateContext {
         tcx,
         enclosing_body: None,
         cached_typeck_results: Cell::new(None),
         param_env: ty::ParamEnv::empty(),
-        access_levels,
+        effective_visibilities,
         lint_store: unerased_lint_store(tcx),
         last_node_with_lint_attrs: hir::CRATE_HIR_ID,
         generics: None,

compiler/rustc_lint/src/lib.rs

@@ -212,7 +212,7 @@ macro_rules! late_lint_mod_passes {
                 TypeLimits: TypeLimits::new(),
                 NonSnakeCase: NonSnakeCase,
                 InvalidNoMangleItems: InvalidNoMangleItems,
-                // Depends on access levels
+                // Depends on effective visibilities
                 UnreachablePub: UnreachablePub,
                 ExplicitOutlivesRequirements: ExplicitOutlivesRequirements,
                 InvalidValue: InvalidValue,

compiler/rustc_metadata/src/rmeta/encoder.rs

@@ -787,9 +787,8 @@ fn should_encode_attr(
     } else if attr.doc_str().is_some() {
         // We keep all public doc comments because they might be "imported" into downstream crates
         // if they use `#[doc(inline)]` to copy an item's documentation into their own.
-        *is_def_id_public.get_or_insert_with(|| {
-            tcx.privacy_access_levels(()).get_effective_vis(def_id).is_some()
-        })
+        *is_def_id_public
+            .get_or_insert_with(|| tcx.effective_visibilities(()).effective_vis(def_id).is_some())
     } else if attr.has_name(sym::doc) {
         // If this is a `doc` attribute, and it's marked `inline` (as in `#[doc(inline)]`), we can
         // remove it. It won't be inlinable in downstream crates.

compiler/rustc_middle/src/arena.rs

@@ -77,7 +77,7 @@ macro_rules! arena_types {
                     rustc_middle::infer::canonical::QueryResponse<'tcx, rustc_middle::ty::Ty<'tcx>>
                 >,
             [] all_traits: Vec<rustc_hir::def_id::DefId>,
-            [] privacy_access_levels: rustc_middle::middle::privacy::AccessLevels,
+            [] effective_visibilities: rustc_middle::middle::privacy::EffectiveVisibilities,
             [] foreign_module: rustc_session::cstore::ForeignModule,
             [] foreign_modules: Vec<rustc_session::cstore::ForeignModule>,
             [] upvars_mentioned: rustc_data_structures::fx::FxIndexMap<rustc_hir::HirId, rustc_hir::Upvar>,

compiler/rustc_middle/src/middle/privacy.rs

@@ -9,106 +9,101 @@ use rustc_query_system::ich::StableHashingContext;
 use rustc_span::def_id::{DefId, LocalDefId};
 use std::hash::Hash;
 
-/// Represents the levels of accessibility an item can have.
+/// Represents the levels of effective visibility an item can have.
 ///
-/// The variants are sorted in ascending order of accessibility.
+/// The variants are sorted in ascending order of directness.
 #[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, HashStable)]
-pub enum AccessLevel {
-    /// Superset of `AccessLevel::Reachable` used to mark impl Trait items.
-    ReachableFromImplTrait,
-    /// Exported items + items participating in various kinds of public interfaces,
-    /// but not directly nameable. For example, if function `fn f() -> T {...}` is
-    /// public, then type `T` is reachable. Its values can be obtained by other crates
-    /// even if the type itself is not nameable.
+pub enum Level {
+    /// Superset of `Reachable` including items leaked through return position `impl Trait`.
+    ReachableThroughImplTrait,
+    /// Item is either reexported, or leaked through any kind of interface.
+    /// For example, if function `fn f() -> T {...}` is directly public, then type `T` is publicly
+    /// reachable and its values can be obtained by other crates even if the type itself is not
+    /// nameable.
     Reachable,
-    /// Public items + items accessible to other crates with the help of `pub use` re-exports.
-    Exported,
-    /// Items accessible to other crates directly, without the help of re-exports.
-    Public,
+    /// Item is accessible either directly, or with help of `use` reexports.
+    Reexported,
+    /// Item is directly accessible, without help of reexports.
+    Direct,
 }
 
-impl AccessLevel {
-    pub fn all_levels() -> [AccessLevel; 4] {
-        [
-            AccessLevel::Public,
-            AccessLevel::Exported,
-            AccessLevel::Reachable,
-            AccessLevel::ReachableFromImplTrait,
-        ]
+impl Level {
+    pub fn all_levels() -> [Level; 4] {
+        [Level::Direct, Level::Reexported, Level::Reachable, Level::ReachableThroughImplTrait]
     }
 }
 
 #[derive(Clone, Copy, PartialEq, Eq, Debug, HashStable)]
 pub struct EffectiveVisibility {
-    public: Visibility,
-    exported: Visibility,
+    direct: Visibility,
+    reexported: Visibility,
     reachable: Visibility,
-    reachable_from_impl_trait: Visibility,
+    reachable_through_impl_trait: Visibility,
 }
 
 impl EffectiveVisibility {
-    pub fn get(&self, tag: AccessLevel) -> &Visibility {
-        match tag {
-            AccessLevel::Public => &self.public,
-            AccessLevel::Exported => &self.exported,
-            AccessLevel::Reachable => &self.reachable,
-            AccessLevel::ReachableFromImplTrait => &self.reachable_from_impl_trait,
+    pub fn at_level(&self, level: Level) -> &Visibility {
+        match level {
+            Level::Direct => &self.direct,
+            Level::Reexported => &self.reexported,
+            Level::Reachable => &self.reachable,
+            Level::ReachableThroughImplTrait => &self.reachable_through_impl_trait,
         }
     }
 
-    fn get_mut(&mut self, tag: AccessLevel) -> &mut Visibility {
-        match tag {
-            AccessLevel::Public => &mut self.public,
-            AccessLevel::Exported => &mut self.exported,
-            AccessLevel::Reachable => &mut self.reachable,
-            AccessLevel::ReachableFromImplTrait => &mut self.reachable_from_impl_trait,
+    fn at_level_mut(&mut self, level: Level) -> &mut Visibility {
+        match level {
+            Level::Direct => &mut self.direct,
+            Level::Reexported => &mut self.reexported,
+            Level::Reachable => &mut self.reachable,
+            Level::ReachableThroughImplTrait => &mut self.reachable_through_impl_trait,
         }
     }
 
-    pub fn is_public_at_level(&self, tag: AccessLevel) -> bool {
-        self.get(tag).is_public()
+    pub fn is_public_at_level(&self, level: Level) -> bool {
+        self.at_level(level).is_public()
     }
 
     pub fn from_vis(vis: Visibility) -> EffectiveVisibility {
         EffectiveVisibility {
-            public: vis,
-            exported: vis,
+            direct: vis,
+            reexported: vis,
             reachable: vis,
-            reachable_from_impl_trait: vis,
+            reachable_through_impl_trait: vis,
         }
     }
 }
 
-/// Holds a map of accessibility levels for reachable HIR nodes.
+/// Holds a map of effective visibilities for reachable HIR nodes.
 #[derive(Debug, Clone)]
-pub struct AccessLevels<Id = LocalDefId> {
+pub struct EffectiveVisibilities<Id = LocalDefId> {
     map: FxHashMap<Id, EffectiveVisibility>,
 }
 
-impl<Id: Hash + Eq + Copy> AccessLevels<Id> {
-    pub fn is_public_at_level(&self, id: Id, tag: AccessLevel) -> bool {
-        self.get_effective_vis(id)
-            .map_or(false, |effective_vis| effective_vis.is_public_at_level(tag))
+impl<Id: Hash + Eq + Copy> EffectiveVisibilities<Id> {
+    pub fn is_public_at_level(&self, id: Id, level: Level) -> bool {
+        self.effective_vis(id)
+            .map_or(false, |effective_vis| effective_vis.is_public_at_level(level))
     }
 
-    /// See `AccessLevel::Reachable`.
+    /// See `Level::Reachable`.
     pub fn is_reachable(&self, id: Id) -> bool {
-        self.is_public_at_level(id, AccessLevel::Reachable)
+        self.is_public_at_level(id, Level::Reachable)
     }
 
-    /// See `AccessLevel::Exported`.
+    /// See `Level::Reexported`.
     pub fn is_exported(&self, id: Id) -> bool {
-        self.is_public_at_level(id, AccessLevel::Exported)
+        self.is_public_at_level(id, Level::Reexported)
     }
 
-    /// See `AccessLevel::Public`.
-    pub fn is_public(&self, id: Id) -> bool {
-        self.is_public_at_level(id, AccessLevel::Public)
+    /// See `Level::Direct`.
+    pub fn is_directly_public(&self, id: Id) -> bool {
+        self.is_public_at_level(id, Level::Direct)
     }
 
-    pub fn get_access_level(&self, id: Id) -> Option<AccessLevel> {
-        self.get_effective_vis(id).and_then(|effective_vis| {
-            for level in AccessLevel::all_levels() {
+    pub fn public_at_level(&self, id: Id) -> Option<Level> {
+        self.effective_vis(id).and_then(|effective_vis| {
+            for level in Level::all_levels() {
                 if effective_vis.is_public_at_level(level) {
                     return Some(level);
                 }
@@ -117,38 +112,41 @@ impl<Id: Hash + Eq + Copy> AccessLevels<Id> {
         })
     }
 
-    pub fn get_effective_vis(&self, id: Id) -> Option<&EffectiveVisibility> {
+    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) -> AccessLevels<OutId> {
-        AccessLevels { map: self.map.iter().map(|(k, v)| (f(*k), *v)).collect() }
+    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() }
     }
 
-    pub fn set_access_level(
+    pub fn set_public_at_level(
         &mut self,
         id: Id,
         default_vis: impl FnOnce() -> Visibility,
-        tag: AccessLevel,
+        level: Level,
     ) {
         let mut effective_vis = self
-            .get_effective_vis(id)
+            .effective_vis(id)
             .copied()
             .unwrap_or_else(|| EffectiveVisibility::from_vis(default_vis()));
-        for level in AccessLevel::all_levels() {
-            if level <= tag {
-                *effective_vis.get_mut(level) = Visibility::Public;
+        for l in Level::all_levels() {
+            if l <= level {
+                *effective_vis.at_level_mut(l) = Visibility::Public;
             }
         }
         self.map.insert(id, effective_vis);
     }
 }
 
-impl<Id: Hash + Eq + Copy + Into<DefId>> AccessLevels<Id> {
+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(
@@ -157,28 +155,29 @@ impl<Id: Hash + Eq + Copy + Into<DefId>> AccessLevels<Id> {
         nominal_vis: Visibility,
         default_vis: impl FnOnce() -> Visibility,
         parent_id: Id,
-        tag: AccessLevel,
+        level: Level,
         tree: impl DefIdTree,
     ) -> bool {
         let mut changed = false;
-        let mut current_effective_vis = self.get_effective_vis(id).copied().unwrap_or_else(|| {
+        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())
             }
         });
-        if let Some(inherited_effective_vis) = self.get_effective_vis(parent_id) {
-            let mut inherited_effective_vis_at_prev_level = *inherited_effective_vis.get(tag);
+        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 level in AccessLevel::all_levels() {
-                if tag >= level {
-                    let inherited_effective_vis_at_level = *inherited_effective_vis.get(level);
-                    let current_effective_vis_at_level = current_effective_vis.get_mut(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
-                        && tag != level)
+                        && level != l)
                     {
                         calculated_effective_vis =
                             if nominal_vis.is_at_least(inherited_effective_vis_at_level, tree) {
@@ -205,15 +204,15 @@ impl<Id: Hash + Eq + Copy + Into<DefId>> AccessLevels<Id> {
     }
 }
 
-impl<Id> Default for AccessLevels<Id> {
+impl<Id> Default for EffectiveVisibilities<Id> {
     fn default() -> Self {
-        AccessLevels { map: Default::default() }
+        EffectiveVisibilities { map: Default::default() }
     }
 }
 
-impl<'a> HashStable<StableHashingContext<'a>> for AccessLevels {
+impl<'a> HashStable<StableHashingContext<'a>> for EffectiveVisibilities {
     fn hash_stable(&self, hcx: &mut StableHashingContext<'a>, hasher: &mut StableHasher) {
-        let AccessLevels { ref map } = *self;
+        let EffectiveVisibilities { ref map } = *self;
         map.hash_stable(hcx, hasher);
     }
 }