1 files changed, 278 insertions, 0 deletions

diff --git a/crates/hir_def/src/data.rs b/crates/hir_def/src/data.rs
new file mode 100644
index 000000000..9a8eb4ede
--- /dev/null
+++ b/crates/hir_def/src/data.rs
@@ -0,0 +1,278 @@
+//! Contains basic data about various HIR declarations.
+
+use std::sync::Arc;
+
+use hir_expand::{name::Name, InFile};
+use syntax::ast;
+
+use crate::{
+    attr::Attrs,
+    body::Expander,
+    db::DefDatabase,
+    item_tree::{AssocItem, ItemTreeId, ModItem},
+    type_ref::{TypeBound, TypeRef},
+    visibility::RawVisibility,
+    AssocContainerId, AssocItemId, ConstId, ConstLoc, FunctionId, FunctionLoc, HasModule, ImplId,
+    Intern, Lookup, ModuleId, StaticId, TraitId, TypeAliasId, TypeAliasLoc,
+};
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct FunctionData {
+    pub name: Name,
+    pub params: Vec<TypeRef>,
+    pub ret_type: TypeRef,
+    pub attrs: Attrs,
+    /// True if the first param is `self`. This is relevant to decide whether this
+    /// can be called as a method.
+    pub has_self_param: bool,
+    pub is_unsafe: bool,
+    pub is_varargs: bool,
+    pub visibility: RawVisibility,
+}
+
+impl FunctionData {
+    pub(crate) fn fn_data_query(db: &dyn DefDatabase, func: FunctionId) -> Arc<FunctionData> {
+        let loc = func.lookup(db);
+        let item_tree = db.item_tree(loc.id.file_id);
+        let func = &item_tree[loc.id.value];
+
+        Arc::new(FunctionData {
+            name: func.name.clone(),
+            params: func.params.to_vec(),
+            ret_type: func.ret_type.clone(),
+            attrs: item_tree.attrs(ModItem::from(loc.id.value).into()).clone(),
+            has_self_param: func.has_self_param,
+            is_unsafe: func.is_unsafe,
+            is_varargs: func.is_varargs,
+            visibility: item_tree[func.visibility].clone(),
+        })
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct TypeAliasData {
+    pub name: Name,
+    pub type_ref: Option<TypeRef>,
+    pub visibility: RawVisibility,
+    /// Bounds restricting the type alias itself (eg. `type Ty: Bound;` in a trait or impl).
+    pub bounds: Vec<TypeBound>,
+}
+
+impl TypeAliasData {
+    pub(crate) fn type_alias_data_query(
+        db: &dyn DefDatabase,
+        typ: TypeAliasId,
+    ) -> Arc<TypeAliasData> {
+        let loc = typ.lookup(db);
+        let item_tree = db.item_tree(loc.id.file_id);
+        let typ = &item_tree[loc.id.value];
+
+        Arc::new(TypeAliasData {
+            name: typ.name.clone(),
+            type_ref: typ.type_ref.clone(),
+            visibility: item_tree[typ.visibility].clone(),
+            bounds: typ.bounds.to_vec(),
+        })
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct TraitData {
+    pub name: Name,
+    pub items: Vec<(Name, AssocItemId)>,
+    pub auto: bool,
+}
+
+impl TraitData {
+    pub(crate) fn trait_data_query(db: &dyn DefDatabase, tr: TraitId) -> Arc<TraitData> {
+        let tr_loc = tr.lookup(db);
+        let item_tree = db.item_tree(tr_loc.id.file_id);
+        let tr_def = &item_tree[tr_loc.id.value];
+        let name = tr_def.name.clone();
+        let auto = tr_def.auto;
+        let module_id = tr_loc.container.module(db);
+        let container = AssocContainerId::TraitId(tr);
+        let mut expander = Expander::new(db, tr_loc.id.file_id, module_id);
+
+        let items = collect_items(
+            db,
+            module_id,
+            &mut expander,
+            tr_def.items.iter().copied(),
+            tr_loc.id.file_id,
+            container,
+            100,
+        );
+
+        Arc::new(TraitData { name, items, auto })
+    }
+
+    pub fn associated_types(&self) -> impl Iterator<Item = TypeAliasId> + '_ {
+        self.items.iter().filter_map(|(_name, item)| match item {
+            AssocItemId::TypeAliasId(t) => Some(*t),
+            _ => None,
+        })
+    }
+
+    pub fn associated_type_by_name(&self, name: &Name) -> Option<TypeAliasId> {
+        self.items.iter().find_map(|(item_name, item)| match item {
+            AssocItemId::TypeAliasId(t) if item_name == name => Some(*t),
+            _ => None,
+        })
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct ImplData {
+    pub target_trait: Option<TypeRef>,
+    pub target_type: TypeRef,
+    pub items: Vec<AssocItemId>,
+    pub is_negative: bool,
+}
+
+impl ImplData {
+    pub(crate) fn impl_data_query(db: &dyn DefDatabase, id: ImplId) -> Arc<ImplData> {
+        let _p = profile::span("impl_data_query");
+        let impl_loc = id.lookup(db);
+
+        let item_tree = db.item_tree(impl_loc.id.file_id);
+        let impl_def = &item_tree[impl_loc.id.value];
+        let target_trait = impl_def.target_trait.clone();
+        let target_type = impl_def.target_type.clone();
+        let is_negative = impl_def.is_negative;
+        let module_id = impl_loc.container.module(db);
+        let container = AssocContainerId::ImplId(id);
+        let mut expander = Expander::new(db, impl_loc.id.file_id, module_id);
+
+        let items = collect_items(
+            db,
+            module_id,
+            &mut expander,
+            impl_def.items.iter().copied(),
+            impl_loc.id.file_id,
+            container,
+            100,
+        );
+        let items = items.into_iter().map(|(_, item)| item).collect();
+
+        Arc::new(ImplData { target_trait, target_type, items, is_negative })
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct ConstData {
+    /// const _: () = ();
+    pub name: Option<Name>,
+    pub type_ref: TypeRef,
+    pub visibility: RawVisibility,
+}
+
+impl ConstData {
+    pub(crate) fn const_data_query(db: &dyn DefDatabase, konst: ConstId) -> Arc<ConstData> {
+        let loc = konst.lookup(db);
+        let item_tree = db.item_tree(loc.id.file_id);
+        let konst = &item_tree[loc.id.value];
+
+        Arc::new(ConstData {
+            name: konst.name.clone(),
+            type_ref: konst.type_ref.clone(),
+            visibility: item_tree[konst.visibility].clone(),
+        })
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct StaticData {
+    pub name: Option<Name>,
+    pub type_ref: TypeRef,
+    pub visibility: RawVisibility,
+    pub mutable: bool,
+}
+
+impl StaticData {
+    pub(crate) fn static_data_query(db: &dyn DefDatabase, konst: StaticId) -> Arc<StaticData> {
+        let node = konst.lookup(db);
+        let item_tree = db.item_tree(node.id.file_id);
+        let statik = &item_tree[node.id.value];
+
+        Arc::new(StaticData {
+            name: Some(statik.name.clone()),
+            type_ref: statik.type_ref.clone(),
+            visibility: item_tree[statik.visibility].clone(),
+            mutable: statik.mutable,
+        })
+    }
+}
+
+fn collect_items(
+    db: &dyn DefDatabase,
+    module: ModuleId,
+    expander: &mut Expander,
+    assoc_items: impl Iterator<Item = AssocItem>,
+    file_id: crate::HirFileId,
+    container: AssocContainerId,
+    limit: usize,
+) -> Vec<(Name, AssocItemId)> {
+    if limit == 0 {
+        return Vec::new();
+    }
+
+    let item_tree = db.item_tree(file_id);
+    let cfg_options = db.crate_graph()[module.krate].cfg_options.clone();
+
+    let mut items = Vec::new();
+    for item in assoc_items {
+        match item {
+            AssocItem::Function(id) => {
+                let item = &item_tree[id];
+                let attrs = item_tree.attrs(ModItem::from(id).into());
+                if !attrs.is_cfg_enabled(&cfg_options) {
+                    continue;
+                }
+                let def = FunctionLoc { container, id: ItemTreeId::new(file_id, id) }.intern(db);
+                items.push((item.name.clone(), def.into()));
+            }
+            // FIXME: cfg?
+            AssocItem::Const(id) => {
+                let item = &item_tree[id];
+                let name = match item.name.clone() {
+                    Some(name) => name,
+                    None => continue,
+                };
+                let def = ConstLoc { container, id: ItemTreeId::new(file_id, id) }.intern(db);
+                items.push((name, def.into()));
+            }
+            AssocItem::TypeAlias(id) => {
+                let item = &item_tree[id];
+                let def = TypeAliasLoc { container, id: ItemTreeId::new(file_id, id) }.intern(db);
+                items.push((item.name.clone(), def.into()));
+            }
+            AssocItem::MacroCall(call) => {
+                let call = &item_tree[call];
+                let ast_id_map = db.ast_id_map(file_id);
+                let root = db.parse_or_expand(file_id).unwrap();
+                let call = ast_id_map.get(call.ast_id).to_node(&root);
+
+                if let Some((mark, mac)) = expander.enter_expand(db, None, call) {
+                    let src: InFile<ast::MacroItems> = expander.to_source(mac);
+                    let item_tree = db.item_tree(src.file_id);
+                    let iter =
+                        item_tree.top_level_items().iter().filter_map(ModItem::as_assoc_item);
+                    items.extend(collect_items(
+                        db,
+                        module,
+                        expander,
+                        iter,
+                        src.file_id,
+                        container,
+                        limit - 1,
+                    ));
+
+                    expander.exit(db, mark);
+                }
+            }
+        }
+    }
+
+    items
+}