3 files changed, 131 insertions, 1 deletions

diff --git a/crates/ra_hir_def/src/db.rs b/crates/ra_hir_def/src/db.rs
index c55fd4111..1761e2187 100644
--- a/crates/ra_hir_def/src/db.rs
+++ b/crates/ra_hir_def/src/db.rs
@@ -14,9 +14,10 @@ use crate::{
     generics::GenericParams,
     lang_item::{LangItemTarget, LangItems},
     nameres::{raw::RawItems, CrateDefMap},
+    visibility::Visibility,
     AttrDefId, ConstId, ConstLoc, DefWithBodyId, EnumId, EnumLoc, FunctionId, FunctionLoc,
     GenericDefId, ImplId, ImplLoc, ModuleId, StaticId, StaticLoc, StructId, StructLoc, TraitId,
-    TraitLoc, TypeAliasId, TypeAliasLoc, UnionId, UnionLoc,
+    TraitLoc, TypeAliasId, TypeAliasLoc, UnionId, UnionLoc, VisibilityDefId,
 };
 
 #[salsa::query_group(InternDatabaseStorage)]
@@ -90,6 +91,9 @@ pub trait DefDatabase: InternDatabase + AstDatabase {
     #[salsa::invoke(Attrs::attrs_query)]
     fn attrs(&self, def: AttrDefId) -> Attrs;
 
+    #[salsa::invoke(Visibility::visibility_query)]
+    fn visibility(&self, def: VisibilityDefId) -> Visibility;
+
     #[salsa::invoke(LangItems::module_lang_items_query)]
     fn module_lang_items(&self, module: ModuleId) -> Option<Arc<LangItems>>;
 
diff --git a/crates/ra_hir_def/src/lib.rs b/crates/ra_hir_def/src/lib.rs
index f6c7f38d1..72a59d867 100644
--- a/crates/ra_hir_def/src/lib.rs
+++ b/crates/ra_hir_def/src/lib.rs
@@ -36,6 +36,8 @@ pub mod nameres;
 pub mod src;
 pub mod child_by_source;
 
+pub mod visibility;
+
 #[cfg(test)]
 mod test_db;
 #[cfg(test)]
@@ -323,6 +325,29 @@ impl_froms!(
     ImplId
 );
 
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
+pub enum VisibilityDefId {
+    ModuleId(ModuleId),
+    StructFieldId(StructFieldId),
+    AdtId(AdtId),
+    FunctionId(FunctionId),
+    StaticId(StaticId),
+    ConstId(ConstId),
+    TraitId(TraitId),
+    TypeAliasId(TypeAliasId),
+}
+
+impl_froms!(
+    VisibilityDefId: ModuleId,
+    StructFieldId,
+    AdtId(StructId, EnumId, UnionId),
+    StaticId,
+    ConstId,
+    FunctionId,
+    TraitId,
+    TypeAliasId
+);
+
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub enum VariantId {
     EnumVariantId(EnumVariantId),
diff --git a/crates/ra_hir_def/src/visibility.rs b/crates/ra_hir_def/src/visibility.rs
new file mode 100644
index 000000000..7d881911d
--- /dev/null
+++ b/crates/ra_hir_def/src/visibility.rs
@@ -0,0 +1,101 @@
+use std::sync::Arc;
+
+use either::Either;
+
+use hir_expand::InFile;
+use ra_syntax::ast::{self, VisibilityOwner};
+
+use crate::{
+    db::DefDatabase,
+    path::{ModPath, PathKind},
+    src::{HasChildSource, HasSource},
+    AdtId, Lookup, VisibilityDefId,
+};
+
+/// Visibility of an item, not yet resolved.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum Visibility {
+    // FIXME: We could avoid the allocation in many cases by special-casing
+    // pub(crate), pub(super) and private. Alternatively, `ModPath` could be
+    // made to contain an Arc<[Segment]> instead of a Vec?
+    /// `pub(in module)`, `pub(crate)` or `pub(super)`. Also private, which is
+    /// equivalent to `pub(self)`.
+    Module(Arc<ModPath>),
+    /// `pub`.
+    Public,
+}
+
+impl Visibility {
+    pub(crate) fn visibility_query(db: &impl DefDatabase, def: VisibilityDefId) -> Visibility {
+        match def {
+            VisibilityDefId::ModuleId(module) => {
+                let def_map = db.crate_def_map(module.krate);
+                let src = match def_map[module.local_id].declaration_source(db) {
+                    Some(it) => it,
+                    None => return Visibility::private(),
+                };
+                Visibility::from_ast(db, src.map(|it| it.visibility()))
+            }
+            VisibilityDefId::StructFieldId(it) => {
+                let src = it.parent.child_source(db);
+                // TODO: enum variant fields should be public by default
+                let vis_node = src.map(|m| match &m[it.local_id] {
+                    Either::Left(tuple) => tuple.visibility(),
+                    Either::Right(record) => record.visibility(),
+                });
+                Visibility::from_ast(db, vis_node)
+            }
+            VisibilityDefId::AdtId(it) => match it {
+                AdtId::StructId(it) => visibility_from_loc(it.lookup(db), db),
+                AdtId::EnumId(it) => visibility_from_loc(it.lookup(db), db),
+                AdtId::UnionId(it) => visibility_from_loc(it.lookup(db), db),
+            },
+            VisibilityDefId::TraitId(it) => visibility_from_loc(it.lookup(db), db),
+            VisibilityDefId::ConstId(it) => visibility_from_loc(it.lookup(db), db),
+            VisibilityDefId::StaticId(it) => visibility_from_loc(it.lookup(db), db),
+            VisibilityDefId::FunctionId(it) => visibility_from_loc(it.lookup(db), db),
+            VisibilityDefId::TypeAliasId(it) => visibility_from_loc(it.lookup(db), db),
+        }
+    }
+
+    fn private() -> Visibility {
+        let path = ModPath { kind: PathKind::Super(0), segments: Vec::new() };
+        Visibility::Module(Arc::new(path))
+    }
+
+    fn from_ast(db: &impl DefDatabase, node: InFile<Option<ast::Visibility>>) -> Visibility {
+        let file_id = node.file_id;
+        let node = match node.value {
+            None => return Visibility::private(),
+            Some(node) => node,
+        };
+        match node.kind() {
+            ast::VisibilityKind::In(path) => {
+                let path = ModPath::from_src(path, &hir_expand::hygiene::Hygiene::new(db, file_id));
+                let path = match path {
+                    None => return Visibility::private(),
+                    Some(path) => path,
+                };
+                Visibility::Module(Arc::new(path))
+            }
+            ast::VisibilityKind::PubCrate => {
+                let path = ModPath { kind: PathKind::Crate, segments: Vec::new() };
+                Visibility::Module(Arc::new(path))
+            }
+            ast::VisibilityKind::PubSuper => {
+                let path = ModPath { kind: PathKind::Super(1), segments: Vec::new() };
+                Visibility::Module(Arc::new(path))
+            }
+            ast::VisibilityKind::Pub => Visibility::Public,
+        }
+    }
+}
+
+fn visibility_from_loc<T>(node: T, db: &impl DefDatabase) -> Visibility
+where
+    T: HasSource,
+    T::Value: ast::VisibilityOwner,
+{
+    let src = node.source(db);
+    Visibility::from_ast(db, src.map(|n| n.visibility()))
+}