1 files changed, 172 insertions, 0 deletions

diff --git a/crates/ra_ide_db/src/defs.rs b/crates/ra_ide_db/src/defs.rs
new file mode 100644
index 000000000..030f44f86
--- /dev/null
+++ b/crates/ra_ide_db/src/defs.rs
@@ -0,0 +1,172 @@
+//! `NameDefinition` keeps information about the element we want to search references for.
+//! The element is represented by `NameKind`. It's located inside some `container` and
+//! has a `visibility`, which defines a search scope.
+//! Note that the reference search is possible for not all of the classified items.
+
+// FIXME: this badly needs rename/rewrite (matklad, 2020-02-06).
+
+use hir::{
+    Adt, HasSource, ImplBlock, InFile, Local, MacroDef, Module, ModuleDef, SourceBinder,
+    StructField, TypeParam, VariantDef,
+};
+use ra_prof::profile;
+use ra_syntax::{
+    ast::{self, AstNode, VisibilityOwner},
+    match_ast,
+};
+
+use crate::RootDatabase;
+
+#[derive(Debug, PartialEq, Eq)]
+pub enum NameKind {
+    Macro(MacroDef),
+    StructField(StructField),
+    ModuleDef(ModuleDef),
+    SelfType(ImplBlock),
+    Local(Local),
+    TypeParam(TypeParam),
+}
+
+#[derive(PartialEq, Eq)]
+pub struct NameDefinition {
+    pub visibility: Option<ast::Visibility>,
+    /// FIXME: this doesn't really make sense. For example, builtin types don't
+    /// really have a module.
+    pub container: Module,
+    pub kind: NameKind,
+}
+
+pub fn classify_name(
+    sb: &mut SourceBinder<RootDatabase>,
+    name: InFile<&ast::Name>,
+) -> Option<NameDefinition> {
+    let _p = profile("classify_name");
+    let parent = name.value.syntax().parent()?;
+
+    match_ast! {
+        match parent {
+            ast::BindPat(it) => {
+                let src = name.with_value(it);
+                let local = sb.to_def(src)?;
+                Some(NameDefinition {
+                    visibility: None,
+                    container: local.module(sb.db),
+                    kind: NameKind::Local(local),
+                })
+            },
+            ast::RecordFieldDef(it) => {
+                let src = name.with_value(it);
+                let field: hir::StructField = sb.to_def(src)?;
+                Some(from_struct_field(sb.db, field))
+            },
+            ast::Module(it) => {
+                let def = sb.to_def(name.with_value(it))?;
+                Some(from_module_def(sb.db, def.into(), None))
+            },
+            ast::StructDef(it) => {
+                let src = name.with_value(it);
+                let def: hir::Struct = sb.to_def(src)?;
+                Some(from_module_def(sb.db, def.into(), None))
+            },
+            ast::EnumDef(it) => {
+                let src = name.with_value(it);
+                let def: hir::Enum = sb.to_def(src)?;
+                Some(from_module_def(sb.db, def.into(), None))
+            },
+            ast::TraitDef(it) => {
+                let src = name.with_value(it);
+                let def: hir::Trait = sb.to_def(src)?;
+                Some(from_module_def(sb.db, def.into(), None))
+            },
+            ast::StaticDef(it) => {
+                let src = name.with_value(it);
+                let def: hir::Static = sb.to_def(src)?;
+                Some(from_module_def(sb.db, def.into(), None))
+            },
+            ast::EnumVariant(it) => {
+                let src = name.with_value(it);
+                let def: hir::EnumVariant = sb.to_def(src)?;
+                Some(from_module_def(sb.db, def.into(), None))
+            },
+            ast::FnDef(it) => {
+                let src = name.with_value(it);
+                let def: hir::Function = sb.to_def(src)?;
+                Some(from_module_def(sb.db, def.into(), None))
+            },
+            ast::ConstDef(it) => {
+                let src = name.with_value(it);
+                let def: hir::Const = sb.to_def(src)?;
+                Some(from_module_def(sb.db, def.into(), None))
+            },
+            ast::TypeAliasDef(it) => {
+                let src = name.with_value(it);
+                let def: hir::TypeAlias = sb.to_def(src)?;
+                Some(from_module_def(sb.db, def.into(), None))
+            },
+            ast::MacroCall(it) => {
+                let src = name.with_value(it);
+                let def = sb.to_def(src.clone())?;
+
+                let module = sb.to_module_def(src.file_id.original_file(sb.db))?;
+
+                Some(NameDefinition {
+                    visibility: None,
+                    container: module,
+                    kind: NameKind::Macro(def),
+                })
+            },
+            ast::TypeParam(it) => {
+                let src = name.with_value(it);
+                let def = sb.to_def(src)?;
+                Some(NameDefinition {
+                    visibility: None,
+                    container: def.module(sb.db),
+                    kind: NameKind::TypeParam(def),
+                })
+            },
+            _ => None,
+        }
+    }
+}
+
+pub fn from_struct_field(db: &RootDatabase, field: StructField) -> NameDefinition {
+    let kind = NameKind::StructField(field);
+    let parent = field.parent_def(db);
+    let container = parent.module(db);
+    let visibility = match parent {
+        VariantDef::Struct(s) => s.source(db).value.visibility(),
+        VariantDef::Union(e) => e.source(db).value.visibility(),
+        VariantDef::EnumVariant(e) => e.source(db).value.parent_enum().visibility(),
+    };
+    NameDefinition { kind, container, visibility }
+}
+
+pub fn from_module_def(
+    db: &RootDatabase,
+    def: ModuleDef,
+    module: Option<Module>,
+) -> NameDefinition {
+    let kind = NameKind::ModuleDef(def);
+    let (container, visibility) = match def {
+        ModuleDef::Module(it) => {
+            let container = it.parent(db).or_else(|| Some(it)).unwrap();
+            let visibility = it.declaration_source(db).and_then(|s| s.value.visibility());
+            (container, visibility)
+        }
+        ModuleDef::EnumVariant(it) => {
+            let container = it.module(db);
+            let visibility = it.source(db).value.parent_enum().visibility();
+            (container, visibility)
+        }
+        ModuleDef::Function(it) => (it.module(db), it.source(db).value.visibility()),
+        ModuleDef::Const(it) => (it.module(db), it.source(db).value.visibility()),
+        ModuleDef::Static(it) => (it.module(db), it.source(db).value.visibility()),
+        ModuleDef::Trait(it) => (it.module(db), it.source(db).value.visibility()),
+        ModuleDef::TypeAlias(it) => (it.module(db), it.source(db).value.visibility()),
+        ModuleDef::Adt(Adt::Struct(it)) => (it.module(db), it.source(db).value.visibility()),
+        ModuleDef::Adt(Adt::Union(it)) => (it.module(db), it.source(db).value.visibility()),
+        ModuleDef::Adt(Adt::Enum(it)) => (it.module(db), it.source(db).value.visibility()),
+        ModuleDef::BuiltinType(..) => (module.unwrap(), None),
+    };
+    NameDefinition { kind, container, visibility }
+}