3 files changed, 273 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..cee6dde8e
--- /dev/null
+++ b/crates/ra_ide_db/src/defs.rs
@@ -0,0 +1,196 @@
+//! `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, AssocItem, 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),
+    Field(StructField),
+    AssocItem(AssocItem),
+    Def(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)?;
+                if parent.parent().and_then(ast::ItemList::cast).is_some() {
+                    Some(from_assoc_item(sb.db, def.into()))
+                } else {
+                    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)?;
+                if parent.parent().and_then(ast::ItemList::cast).is_some() {
+                    Some(from_assoc_item(sb.db, def.into()))
+                } else {
+                    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)?;
+                if parent.parent().and_then(ast::ItemList::cast).is_some() {
+                    Some(from_assoc_item(sb.db, def.into()))
+                } else {
+                    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_assoc_item(db: &RootDatabase, item: AssocItem) -> NameDefinition {
+    let container = item.module(db);
+    let visibility = match item {
+        AssocItem::Function(f) => f.source(db).value.visibility(),
+        AssocItem::Const(c) => c.source(db).value.visibility(),
+        AssocItem::TypeAlias(a) => a.source(db).value.visibility(),
+    };
+    let kind = NameKind::AssocItem(item);
+    NameDefinition { kind, container, visibility }
+}
+
+pub fn from_struct_field(db: &RootDatabase, field: StructField) -> NameDefinition {
+    let kind = NameKind::Field(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::Def(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 }
+}
diff --git a/crates/ra_ide_db/src/imports_locator.rs b/crates/ra_ide_db/src/imports_locator.rs
new file mode 100644
index 000000000..21e637608
--- /dev/null
+++ b/crates/ra_ide_db/src/imports_locator.rs
@@ -0,0 +1,75 @@
+//! This module contains an import search funcionality that is provided to the ra_assists module.
+//! Later, this should be moved away to a separate crate that is accessible from the ra_assists module.
+
+use hir::{db::HirDatabase, ModuleDef, SourceBinder};
+use ra_assists::ImportsLocator;
+use ra_prof::profile;
+use ra_syntax::{ast, AstNode, SyntaxKind::NAME};
+
+use crate::{
+    defs::classify_name,
+    defs::NameKind,
+    symbol_index::{self, FileSymbol, Query},
+    RootDatabase,
+};
+
+pub struct ImportsLocatorIde<'a> {
+    source_binder: SourceBinder<'a, RootDatabase>,
+}
+
+impl<'a> ImportsLocatorIde<'a> {
+    pub fn new(db: &'a RootDatabase) -> Self {
+        Self { source_binder: SourceBinder::new(db) }
+    }
+
+    fn get_name_definition(
+        &mut self,
+        db: &impl HirDatabase,
+        import_candidate: &FileSymbol,
+    ) -> Option<NameKind> {
+        let _p = profile("get_name_definition");
+        let file_id = import_candidate.file_id.into();
+        let candidate_node = import_candidate.ptr.to_node(&db.parse_or_expand(file_id)?);
+        let candidate_name_node = if candidate_node.kind() != NAME {
+            candidate_node.children().find(|it| it.kind() == NAME)?
+        } else {
+            candidate_node
+        };
+        classify_name(
+            &mut self.source_binder,
+            hir::InFile { file_id, value: &ast::Name::cast(candidate_name_node)? },
+        )
+        .map(|it| it.kind)
+    }
+}
+
+impl ImportsLocator for ImportsLocatorIde<'_> {
+    fn find_imports(&mut self, name_to_import: &str) -> Vec<ModuleDef> {
+        let _p = profile("search_for_imports");
+        let db = self.source_binder.db;
+
+        let project_results = {
+            let mut query = Query::new(name_to_import.to_string());
+            query.exact();
+            query.limit(40);
+            symbol_index::world_symbols(db, query)
+        };
+        let lib_results = {
+            let mut query = Query::new(name_to_import.to_string());
+            query.libs();
+            query.exact();
+            query.limit(40);
+            symbol_index::world_symbols(db, query)
+        };
+
+        project_results
+            .into_iter()
+            .chain(lib_results.into_iter())
+            .filter_map(|import_candidate| self.get_name_definition(db, &import_candidate))
+            .filter_map(|name_definition_to_import| match name_definition_to_import {
+                NameKind::Def(module_def) => Some(module_def),
+                _ => None,
+            })
+            .collect()
+    }
+}
diff --git a/crates/ra_ide_db/src/lib.rs b/crates/ra_ide_db/src/lib.rs
index e922d1e5f..877ac3c38 100644
--- a/crates/ra_ide_db/src/lib.rs
+++ b/crates/ra_ide_db/src/lib.rs
@@ -7,6 +7,8 @@ pub mod line_index_utils;
 pub mod feature_flags;
 pub mod symbol_index;
 pub mod change;
+pub mod defs;
+pub mod imports_locator;
 mod wasm_shims;
 
 use std::sync::Arc;