7 files changed, 277 insertions, 58 deletions

diff --git a/crates/ra_hir/src/code_model_api.rs b/crates/ra_hir/src/code_model_api.rs
index 0cf7deac9..865e5e809 100644
--- a/crates/ra_hir/src/code_model_api.rs
+++ b/crates/ra_hir/src/code_model_api.rs
@@ -7,7 +7,7 @@ use ra_syntax::{ast, TreeArc, SyntaxNode};
 use crate::{
     Name, DefId, Path, PerNs, ScopesWithSyntaxMapping, Ty, HirFileId,
     type_ref::TypeRef,
-    nameres::ModuleScope,
+    nameres::{ModuleScope, lower::LoweredImport},
     db::HirDatabase,
     expr::BodySyntaxMapping,
     ty::InferenceResult,
@@ -96,6 +96,15 @@ impl Module {
         self.declaration_source_impl(db)
     }
 
+    /// Returns the syntax of the last path segment corresponding to this import
+    pub fn import_source(
+        &self,
+        db: &impl HirDatabase,
+        import: LoweredImport,
+    ) -> TreeArc<ast::PathSegment> {
+        self.import_source_impl(db, import)
+    }
+
     /// Returns the crate this module is part of.
     pub fn krate(&self, db: &impl HirDatabase) -> Option<Crate> {
         self.krate_impl(db)
diff --git a/crates/ra_hir/src/code_model_impl/module.rs b/crates/ra_hir/src/code_model_impl/module.rs
index a5c032d69..f110548c6 100644
--- a/crates/ra_hir/src/code_model_impl/module.rs
+++ b/crates/ra_hir/src/code_model_impl/module.rs
@@ -5,7 +5,7 @@ use crate::{
     Module, ModuleSource, Problem,
     Crate, DefId, DefLoc, DefKind, Name, Path, PathKind, PerNs, Def,
     module_tree::ModuleId,
-    nameres::ModuleScope,
+    nameres::{ModuleScope, lower::LoweredImport},
     db::HirDatabase,
 };
 
@@ -37,7 +37,7 @@ impl Module {
         Some(link.name(&module_tree).clone())
     }
 
-    pub fn definition_source_impl(&self, db: &impl HirDatabase) -> (FileId, ModuleSource) {
+    pub(crate) fn definition_source_impl(&self, db: &impl HirDatabase) -> (FileId, ModuleSource) {
         let loc = self.def_id.loc(db);
         let file_id = loc.source_item_id.file_id.as_original_file();
         let syntax_node = db.file_item(loc.source_item_id);
@@ -50,7 +50,7 @@ impl Module {
         (file_id, module_source)
     }
 
-    pub fn declaration_source_impl(
+    pub(crate) fn declaration_source_impl(
         &self,
         db: &impl HirDatabase,
     ) -> Option<(FileId, TreeArc<ast::Module>)> {
@@ -66,6 +66,17 @@ impl Module {
         Some((file_id, src))
     }
 
+    pub(crate) fn import_source_impl(
+        &self,
+        db: &impl HirDatabase,
+        import: LoweredImport,
+    ) -> TreeArc<ast::PathSegment> {
+        let loc = self.def_id.loc(db);
+        let source_map = db.lower_module_source_map(loc.source_root_id, loc.module_id);
+        let (_, source) = self.definition_source(db);
+        source_map.get(&source, import)
+    }
+
     pub(crate) fn krate_impl(&self, db: &impl HirDatabase) -> Option<Crate> {
         let root = self.crate_root(db);
         let loc = root.def_id.loc(db);
diff --git a/crates/ra_hir/src/db.rs b/crates/ra_hir/src/db.rs
index 4a3e0fed2..ccc53c454 100644
--- a/crates/ra_hir/src/db.rs
+++ b/crates/ra_hir/src/db.rs
@@ -10,7 +10,7 @@ use crate::{
     FnSignature, FnScopes,
     macros::MacroExpansion,
     module_tree::{ModuleId, ModuleTree},
-    nameres::{ItemMap, lower::InputModuleItems},
+    nameres::{ItemMap, lower::{InputModuleItems, LoweredModule, ImportSourceMap}},
     ty::{InferenceResult, Ty, method_resolution::CrateImplBlocks},
     adt::{StructData, EnumData, EnumVariantData},
     impl_block::ModuleImplBlocks,
@@ -65,6 +65,27 @@ pub trait HirDatabase:
         module_id: ModuleId,
     ) -> Arc<InputModuleItems>;
 
+    #[salsa::invoke(crate::nameres::lower::LoweredModule::lower_module_query)]
+    fn lower_module(
+        &self,
+        source_root_id: SourceRootId,
+        module_id: ModuleId,
+    ) -> (Arc<LoweredModule>, Arc<ImportSourceMap>);
+
+    #[salsa::invoke(crate::nameres::lower::LoweredModule::lower_module_module_query)]
+    fn lower_module_module(
+        &self,
+        source_root_id: SourceRootId,
+        module_id: ModuleId,
+    ) -> Arc<LoweredModule>;
+
+    #[salsa::invoke(crate::nameres::lower::LoweredModule::lower_module_source_map_query)]
+    fn lower_module_source_map(
+        &self,
+        source_root_id: SourceRootId,
+        module_id: ModuleId,
+    ) -> Arc<ImportSourceMap>;
+
     #[salsa::invoke(query_definitions::item_map)]
     fn item_map(&self, source_root_id: SourceRootId) -> Arc<ItemMap>;
 
diff --git a/crates/ra_hir/src/nameres.rs b/crates/ra_hir/src/nameres.rs
index aea95e08c..ab0a9041d 100644
--- a/crates/ra_hir/src/nameres.rs
+++ b/crates/ra_hir/src/nameres.rs
@@ -60,7 +60,7 @@ pub struct Resolution {
     /// None for unresolved
     pub def_id: PerNs<DefId>,
     /// ident by whitch this is imported into local scope.
-    pub import: Option<NamedImport>,
+    pub import: Option<LoweredImport>,
 }
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
@@ -151,10 +151,10 @@ impl<T> PerNs<T> {
 
 pub(crate) struct Resolver<'a, DB> {
     db: &'a DB,
-    input: &'a FxHashMap<ModuleId, Arc<InputModuleItems>>,
+    input: &'a FxHashMap<ModuleId, Arc<LoweredModule>>,
     source_root: SourceRootId,
     module_tree: Arc<ModuleTree>,
-    processed_imports: FxHashSet<(ModuleId, usize)>,
+    processed_imports: FxHashSet<(ModuleId, LoweredImport)>,
     result: ItemMap,
 }
 
@@ -164,7 +164,7 @@ where
 {
     pub(crate) fn new(
         db: &'a DB,
-        input: &'a FxHashMap<ModuleId, Arc<InputModuleItems>>,
+        input: &'a FxHashMap<ModuleId, Arc<LoweredModule>>,
         source_root: SourceRootId,
         module_tree: Arc<ModuleTree>,
     ) -> Resolver<'a, DB> {
@@ -197,7 +197,7 @@ where
         self.result
     }
 
-    fn populate_module(&mut self, module_id: ModuleId, input: Arc<InputModuleItems>) {
+    fn populate_module(&mut self, module_id: ModuleId, input: Arc<LoweredModule>) {
         let mut module_items = ModuleScope::default();
 
         // Populate extern crates prelude
@@ -220,14 +220,14 @@ where
                 }
             };
         }
-        for import in input.imports.iter() {
-            if let Some(name) = import.path.segments.iter().last() {
-                if let ImportKind::Named(import) = import.kind {
+        for (import_id, import_data) in input.imports.iter() {
+            if let Some(name) = import_data.path.segments.iter().last() {
+                if !import_data.is_glob {
                     module_items.items.insert(
                         name.clone(),
                         Resolution {
                             def_id: PerNs::none(),
-                            import: Some(import),
+                            import: Some(import_id),
                         },
                     );
                 }
@@ -281,23 +281,27 @@ where
     }
 
     fn resolve_imports(&mut self, module_id: ModuleId) {
-        for (i, import) in self.input[&module_id].imports.iter().enumerate() {
-            if self.processed_imports.contains(&(module_id, i)) {
+        for (import_id, import_data) in self.input[&module_id].imports.iter() {
+            if self.processed_imports.contains(&(module_id, import_id)) {
                 // already done
                 continue;
             }
-            if self.resolve_import(module_id, import) {
-                log::debug!("import {:?} resolved (or definite error)", import);
-                self.processed_imports.insert((module_id, i));
+            if self.resolve_import(module_id, import_id, import_data) {
+                log::debug!("import {:?} resolved (or definite error)", import_id);
+                self.processed_imports.insert((module_id, import_id));
             }
         }
     }
 
-    fn resolve_import(&mut self, module_id: ModuleId, import: &Import) -> bool {
+    fn resolve_import(
+        &mut self,
+        module_id: ModuleId,
+        import_id: LoweredImport,
+        import: &ImportData,
+    ) -> bool {
         log::debug!("resolving import: {:?}", import);
-        let ptr = match import.kind {
-            ImportKind::Glob => return false,
-            ImportKind::Named(ptr) => ptr,
+        if import.is_glob {
+            return false;
         };
 
         let mut curr: ModuleId = match import.path.kind {
@@ -358,7 +362,7 @@ where
                                 self.update(module_id, |items| {
                                     let res = Resolution {
                                         def_id,
-                                        import: Some(ptr),
+                                        import: Some(import_id),
                                     };
                                     items.items.insert(name.clone(), res);
                                 });
@@ -394,7 +398,7 @@ where
                 self.update(module_id, |items| {
                     let res = Resolution {
                         def_id,
-                        import: Some(ptr),
+                        import: Some(import_id),
                     };
                     items.items.insert(name.clone(), res);
                 })
diff --git a/crates/ra_hir/src/nameres/lower.rs b/crates/ra_hir/src/nameres/lower.rs
index 35bdbafbf..6bca14444 100644
--- a/crates/ra_hir/src/nameres/lower.rs
+++ b/crates/ra_hir/src/nameres/lower.rs
@@ -1,10 +1,11 @@
 use std::sync::Arc;
 
 use ra_syntax::{
-    TextRange, SyntaxKind, AstNode,
+    TextRange, SyntaxKind, AstNode, SourceFile, TreeArc,
     ast::{self, ModuleItemOwner},
 };
-use ra_db::{FileId, SourceRootId};
+use ra_db::{SourceRootId, LocalSyntaxPtr};
+use ra_arena::{Arena, RawId, impl_arena_id, map::ArenaMap};
 
 use crate::{
     SourceItemId, SourceFileItemId, Path, ModuleSource, HirDatabase, Name, SourceFileItems,
@@ -139,12 +140,12 @@ impl InputModuleItems {
     fn add_use_item(&mut self, file_items: &SourceFileItems, item: &ast::UseItem) {
         let file_item_id = file_items.id_of_unchecked(item.syntax());
         let start_offset = item.syntax().range().start();
-        Path::expand_use_item(item, |path, range| {
-            let kind = match range {
+        Path::expand_use_item(item, |path, segment| {
+            let kind = match segment {
                 None => ImportKind::Glob,
-                Some(range) => ImportKind::Named(NamedImport {
+                Some(segment) => ImportKind::Named(NamedImport {
                     file_item_id,
-                    relative_range: range - start_offset,
+                    relative_range: segment.syntax().range() - start_offset,
                 }),
             };
             self.imports.push(Import { kind, path })
@@ -199,22 +200,194 @@ pub struct NamedImport {
     pub relative_range: TextRange,
 }
 
-impl NamedImport {
-    // FIXME: this is only here for one use-case in completion. Seems like a
-    // pretty gross special case.
-    pub fn range(&self, db: &impl HirDatabase, file_id: FileId) -> TextRange {
-        let source_item_id = SourceItemId {
-            file_id: file_id.into(),
-            item_id: Some(self.file_item_id),
-        };
-        let syntax = db.file_item(source_item_id);
-        let offset = syntax.range().start();
-        self.relative_range + offset
-    }
-}
-
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub(super) enum ImportKind {
     Glob,
     Named(NamedImport),
 }
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct LoweredImport(RawId);
+impl_arena_id!(LoweredImport);
+
+#[derive(Debug, PartialEq, Eq)]
+pub(super) struct ImportData {
+    pub(super) path: Path,
+    pub(super) is_glob: bool,
+}
+
+#[derive(Debug, Default, PartialEq, Eq)]
+pub struct LoweredModule {
+    pub(super) items: Vec<ModuleItem>,
+    pub(super) imports: Arena<LoweredImport, ImportData>,
+}
+
+#[derive(Debug, Default, PartialEq, Eq)]
+pub struct ImportSourceMap {
+    map: ArenaMap<LoweredImport, LocalSyntaxPtr>,
+}
+
+impl ImportSourceMap {
+    fn insert(&mut self, import: LoweredImport, segment: &ast::PathSegment) {
+        self.map
+            .insert(import, LocalSyntaxPtr::new(segment.syntax()))
+    }
+
+    pub fn get(&self, source: &ModuleSource, import: LoweredImport) -> TreeArc<ast::PathSegment> {
+        let file = match source {
+            ModuleSource::SourceFile(file) => &*file,
+            ModuleSource::Module(m) => m.syntax().ancestors().find_map(SourceFile::cast).unwrap(),
+        };
+
+        ast::PathSegment::cast(&self.map[import].resolve(file))
+            .unwrap()
+            .to_owned()
+    }
+}
+
+impl LoweredModule {
+    pub(crate) fn lower_module_module_query(
+        db: &impl HirDatabase,
+        source_root_id: SourceRootId,
+        module_id: ModuleId,
+    ) -> Arc<LoweredModule> {
+        db.lower_module(source_root_id, module_id).0
+    }
+
+    pub(crate) fn lower_module_source_map_query(
+        db: &impl HirDatabase,
+        source_root_id: SourceRootId,
+        module_id: ModuleId,
+    ) -> Arc<ImportSourceMap> {
+        db.lower_module(source_root_id, module_id).1
+    }
+
+    pub(crate) fn lower_module_query(
+        db: &impl HirDatabase,
+        source_root_id: SourceRootId,
+        module_id: ModuleId,
+    ) -> (Arc<LoweredModule>, Arc<ImportSourceMap>) {
+        let module_tree = db.module_tree(source_root_id);
+        let source = module_id.source(&module_tree);
+        let file_id = source.file_id;
+        let source = ModuleSource::from_source_item_id(db, source);
+        let mut source_map = ImportSourceMap::default();
+        let mut res = LoweredModule::default();
+        match source {
+            ModuleSource::SourceFile(it) => res.fill(
+                &mut source_map,
+                db,
+                source_root_id,
+                module_id,
+                file_id,
+                &mut it.items_with_macros(),
+            ),
+            ModuleSource::Module(it) => {
+                if let Some(item_list) = it.item_list() {
+                    res.fill(
+                        &mut source_map,
+                        db,
+                        source_root_id,
+                        module_id,
+                        file_id,
+                        &mut item_list.items_with_macros(),
+                    )
+                }
+            }
+        };
+        (Arc::new(res), Arc::new(source_map))
+    }
+
+    fn fill(
+        &mut self,
+        source_map: &mut ImportSourceMap,
+        db: &impl HirDatabase,
+        source_root_id: SourceRootId,
+        module_id: ModuleId,
+        file_id: HirFileId,
+        items: &mut Iterator<Item = ast::ItemOrMacro>,
+    ) {
+        let file_items = db.file_items(file_id);
+
+        for item in items {
+            match item {
+                ast::ItemOrMacro::Item(it) => {
+                    self.add_item(source_map, file_id, &file_items, it);
+                }
+                ast::ItemOrMacro::Macro(macro_call) => {
+                    let item_id = file_items.id_of_unchecked(macro_call.syntax());
+                    let loc = MacroCallLoc {
+                        source_root_id,
+                        module_id,
+                        source_item_id: SourceItemId {
+                            file_id,
+                            item_id: Some(item_id),
+                        },
+                    };
+                    let id = loc.id(db);
+                    let file_id = HirFileId::from(id);
+                    let file_items = db.file_items(file_id);
+                    //FIXME: expand recursively
+                    for item in db.hir_source_file(file_id).items() {
+                        self.add_item(source_map, file_id, &file_items, item);
+                    }
+                }
+            }
+        }
+    }
+
+    fn add_item(
+        &mut self,
+        source_map: &mut ImportSourceMap,
+        file_id: HirFileId,
+        file_items: &SourceFileItems,
+        item: &ast::ModuleItem,
+    ) -> Option<()> {
+        match item.kind() {
+            ast::ModuleItemKind::StructDef(it) => {
+                self.items.push(ModuleItem::new(file_id, file_items, it)?)
+            }
+            ast::ModuleItemKind::EnumDef(it) => {
+                self.items.push(ModuleItem::new(file_id, file_items, it)?)
+            }
+            ast::ModuleItemKind::FnDef(it) => {
+                self.items.push(ModuleItem::new(file_id, file_items, it)?)
+            }
+            ast::ModuleItemKind::TraitDef(it) => {
+                self.items.push(ModuleItem::new(file_id, file_items, it)?)
+            }
+            ast::ModuleItemKind::TypeDef(it) => {
+                self.items.push(ModuleItem::new(file_id, file_items, it)?)
+            }
+            ast::ModuleItemKind::ImplBlock(_) => {
+                // impls don't define items
+            }
+            ast::ModuleItemKind::UseItem(it) => self.add_use_item(source_map, it),
+            ast::ModuleItemKind::ExternCrateItem(_) => {
+                // TODO
+            }
+            ast::ModuleItemKind::ConstDef(it) => {
+                self.items.push(ModuleItem::new(file_id, file_items, it)?)
+            }
+            ast::ModuleItemKind::StaticDef(it) => {
+                self.items.push(ModuleItem::new(file_id, file_items, it)?)
+            }
+            ast::ModuleItemKind::Module(it) => {
+                self.items.push(ModuleItem::new(file_id, file_items, it)?)
+            }
+        }
+        Some(())
+    }
+
+    fn add_use_item(&mut self, source_map: &mut ImportSourceMap, item: &ast::UseItem) {
+        Path::expand_use_item(item, |path, segment| {
+            let import = self.imports.alloc(ImportData {
+                path,
+                is_glob: segment.is_none(),
+            });
+            if let Some(segment) = segment {
+                source_map.insert(import, segment)
+            }
+        })
+    }
+}
diff --git a/crates/ra_hir/src/path.rs b/crates/ra_hir/src/path.rs
index 370e10bb8..7b0ce3b61 100644
--- a/crates/ra_hir/src/path.rs
+++ b/crates/ra_hir/src/path.rs
@@ -1,4 +1,4 @@
-use ra_syntax::{ast, AstNode, TextRange};
+use ra_syntax::{ast, AstNode};
 
 use crate::{Name, AsName};
 
@@ -18,7 +18,10 @@ pub enum PathKind {
 
 impl Path {
     /// Calls `cb` with all paths, represented by this use item.
-    pub fn expand_use_item(item: &ast::UseItem, mut cb: impl FnMut(Path, Option<TextRange>)) {
+    pub fn expand_use_item<'a>(
+        item: &'a ast::UseItem,
+        mut cb: impl FnMut(Path, Option<&'a ast::PathSegment>),
+    ) {
         if let Some(tree) = item.use_tree() {
             expand_use_tree(None, tree, &mut cb);
         }
@@ -98,10 +101,10 @@ impl From<Name> for Path {
     }
 }
 
-fn expand_use_tree(
+fn expand_use_tree<'a>(
     prefix: Option<Path>,
-    tree: &ast::UseTree,
-    cb: &mut impl FnMut(Path, Option<TextRange>),
+    tree: &'a ast::UseTree,
+    cb: &mut impl FnMut(Path, Option<&'a ast::PathSegment>),
 ) {
     if let Some(use_tree_list) = tree.use_tree_list() {
         let prefix = match tree.path() {
@@ -125,20 +128,18 @@ fn expand_use_tree(
                 if let Some(segment) = ast_path.segment() {
                     if segment.kind() == Some(ast::PathSegmentKind::SelfKw) {
                         if let Some(prefix) = prefix {
-                            cb(prefix, Some(segment.syntax().range()));
+                            cb(prefix, Some(segment));
                             return;
                         }
                     }
                 }
             }
             if let Some(path) = convert_path(prefix, ast_path) {
-                let range = if tree.has_star() {
-                    None
-                } else {
-                    let range = ast_path.segment().unwrap().syntax().range();
-                    Some(range)
+                if tree.has_star() {
+                    cb(path, None)
+                } else if let Some(segment) = ast_path.segment() {
+                    cb(path, Some(segment))
                 };
-                cb(path, range)
             }
             // TODO: report errors somewhere
             // We get here if we do
diff --git a/crates/ra_hir/src/query_definitions.rs b/crates/ra_hir/src/query_definitions.rs
index 985a02410..074153862 100644
--- a/crates/ra_hir/src/query_definitions.rs
+++ b/crates/ra_hir/src/query_definitions.rs
@@ -46,7 +46,7 @@ pub(super) fn item_map(db: &impl HirDatabase, source_root: SourceRootId) -> Arc<
     let module_tree = db.module_tree(source_root);
     let input = module_tree
         .modules()
-        .map(|id| (id, db.input_module_items(source_root, id)))
+        .map(|id| (id, db.lower_module_module(source_root, id)))
         .collect::<FxHashMap<_, _>>();
 
     let resolver = Resolver::new(db, &input, source_root, module_tree);