5 files changed, 166 insertions, 73 deletions
diff --git a/crates/ra_hir/src/code_model_api.rs b/crates/ra_hir/src/code_model_api.rs
index 73541a8c3..b8ca04c5c 100644
--- a/crates/ra_hir/src/code_model_api.rs
+++ b/crates/ra_hir/src/code_model_api.rs
@@ -184,9 +184,9 @@ impl Module {
        self.problems_impl(db)
    }
-    #[allow(unused_variables)]
    pub fn resolver(&self, db: &impl HirDatabase) -> Resolver {
-        unimplemented!()
+        let item_map = db.item_map(self.krate);
+        Resolver::default().push_module_scope(item_map, self.module_id)
    }
 }
@@ -480,6 +480,24 @@ impl Function {
    pub fn generic_params(&self, db: &impl PersistentHirDatabase) -> Arc<GenericParams> {
        db.generic_params((*self).into())
    }
+    // TODO move to a more general type for 'body-having' items
+    /// Builds a resolver for code inside this item.
+    pub fn resolver(&self, db: &impl HirDatabase) -> Resolver {
+        // take the outer scope...
+        let r = self
+            .impl_block(db)
+            .map(|ib| ib.resolver(db))
+            .unwrap_or_else(|| self.module(db).resolver(db));
+        // ...and add generic params, if present
+        let p = self.generic_params(db);
+        let r = if !p.params.is_empty() {
+            r.push_generic_params_scope(p)
+        } else {
+            r
+        };
+        r
+    }
 }
 impl Docs for Function {
diff --git a/crates/ra_hir/src/expr.rs b/crates/ra_hir/src/expr.rs
index 6d124fe2f..c09d3fbf9 100644
--- a/crates/ra_hir/src/expr.rs
+++ b/crates/ra_hir/src/expr.rs
@@ -27,6 +27,9 @@ impl_arena_id!(ExprId);
 /// The body of an item (function, const etc.).
 #[derive(Debug, Eq, PartialEq)]
 pub struct Body {
+    // TODO: this should be more general, consts & statics also have bodies
+    /// The Function of the item this body belongs to
+    owner: Function,
    exprs: Arena<ExprId, Expr>,
    pats: Arena<PatId, Pat>,
    /// The patterns for the function's parameters. While the parameter types are
@@ -63,12 +66,26 @@ impl Body {
        self.body_expr
    }
-    #[allow(unused_variables)]
+    pub fn owner(&self) -> Function {
-    pub fn resolver_for_expr(&self, expr_id: ExprId) -> Resolver {
+        self.owner
-        unimplemented!()
    }
 }
+// needs arbitrary_self_types to be a method... or maybe move to the def?
+#[allow(dead_code)]
+pub fn resolver_for_expr(body: Arc<Body>, db: &impl HirDatabase, expr_id: ExprId) -> Resolver {
+    let mut r = body.owner.resolver(db);
+    if !body.params.is_empty() {
+        r = r.push_function_params(Arc::clone(&body));
+    }
+    let scopes = db.expr_scopes(body.owner);
+    let scope_chain = scopes.scope_chain_for(expr_id).collect::<Vec<_>>();
+    for scope in scope_chain.into_iter().rev() {
+        r = r.push_expr_scope(Arc::clone(&scopes), scope);
+    }
+    r
+}
 impl Index<ExprId> for Body {
    type Output = Expr;
@@ -453,23 +470,29 @@ pub(crate) fn body_hir(db: &impl HirDatabase, func: Function) -> Arc<Body> {
 }
 struct ExprCollector {
+    owner: Function,
    exprs: Arena<ExprId, Expr>,
    pats: Arena<PatId, Pat>,
    expr_syntax_mapping: FxHashMap<SyntaxNodePtr, ExprId>,
    expr_syntax_mapping_back: ArenaMap<ExprId, SyntaxNodePtr>,
    pat_syntax_mapping: FxHashMap<SyntaxNodePtr, PatId>,
    pat_syntax_mapping_back: ArenaMap<PatId, SyntaxNodePtr>,
+    params: Vec<PatId>,
+    body_expr: Option<ExprId>,
 }
 impl ExprCollector {
-    fn new() -> Self {
+    fn new(owner: Function) -> Self {
        ExprCollector {
+            owner,
            exprs: Arena::default(),
            pats: Arena::default(),
            expr_syntax_mapping: FxHashMap::default(),
            expr_syntax_mapping_back: ArenaMap::default(),
            pat_syntax_mapping: FxHashMap::default(),
            pat_syntax_mapping_back: ArenaMap::default(),
+            params: Vec::new(),
+            body_expr: None,
        }
    }
@@ -907,10 +930,7 @@ impl ExprCollector {
                });
                fields.extend(iter);
-                Pat::Struct {
+                Pat::Struct { path, args: fields }
-                    path: path,
-                    args: fields,
-                }
            }
            // TODO: implement
@@ -928,12 +948,48 @@ impl ExprCollector {
        }
    }
-    fn into_body_syntax_mapping(self, params: Vec<PatId>, body_expr: ExprId) -> BodySyntaxMapping {
+    fn collect_fn_body(&mut self, node: &ast::FnDef) {
+        if let Some(param_list) = node.param_list() {
+            if let Some(self_param) = param_list.self_param() {
+                let self_param = SyntaxNodePtr::new(
+                    self_param
+                        .self_kw()
+                        .expect("self param without self keyword")
+                        .syntax(),
+                );
+                let param_pat = self.alloc_pat(
+                    Pat::Bind {
+                        name: Name::self_param(),
+                        mode: BindingAnnotation::Unannotated,
+                        subpat: None,
+                    },
+                    self_param,
+                );
+                self.params.push(param_pat);
+            }
+            for param in param_list.params() {
+                let pat = if let Some(pat) = param.pat() {
+                    pat
+                } else {
+                    continue;
+                };
+                let param_pat = self.collect_pat(pat);
+                self.params.push(param_pat);
+            }
+        };
+        let body = self.collect_block_opt(node.body());
+        self.body_expr = Some(body);
+    }
+    fn into_body_syntax_mapping(self) -> BodySyntaxMapping {
        let body = Body {
+            owner: self.owner,
            exprs: self.exprs,
            pats: self.pats,
-            params,
+            params: self.params,
-            body_expr,
+            body_expr: self.body_expr.expect("A body should have been collected"),
        };
        BodySyntaxMapping {
            body: Arc::new(body),
@@ -945,49 +1001,18 @@ impl ExprCollector {
    }
 }
-pub(crate) fn collect_fn_body_syntax(node: &ast::FnDef) -> BodySyntaxMapping {
+pub(crate) fn body_syntax_mapping(db: &impl HirDatabase, func: Function) -> Arc<BodySyntaxMapping> {
-    let mut collector = ExprCollector::new();
+    let mut collector = ExprCollector::new(func);
-    let params = if let Some(param_list) = node.param_list() {
-        let mut params = Vec::new();
-        if let Some(self_param) = param_list.self_param() {
-            let self_param = SyntaxNodePtr::new(
-                self_param
-                    .self_kw()
-                    .expect("self param without self keyword")
-                    .syntax(),
-            );
-            let param = collector.alloc_pat(
-                Pat::Bind {
-                    name: Name::self_param(),
-                    mode: BindingAnnotation::Unannotated,
-                    subpat: None,
-                },
-                self_param,
-            );
-            params.push(param);
-        }
-        for param in param_list.params() {
+    // TODO: consts, etc.
-            let pat = if let Some(pat) = param.pat() {
+    collector.collect_fn_body(&func.source(db).1);
-                pat
-            } else {
-                continue;
-            };
-            params.push(collector.collect_pat(pat));
-        }
-        params
-    } else {
-        Vec::new()
-    };
-    let body = collector.collect_block_opt(node.body());
+    Arc::new(collector.into_body_syntax_mapping())
-    collector.into_body_syntax_mapping(params, body)
 }
-pub(crate) fn body_syntax_mapping(db: &impl HirDatabase, func: Function) -> Arc<BodySyntaxMapping> {
+#[cfg(test)]
-    let (_, fn_def) = func.source(db);
+pub(crate) fn collect_fn_body_syntax(function: Function, node: &ast::FnDef) -> BodySyntaxMapping {
-    let body_syntax_mapping = collect_fn_body_syntax(&fn_def);
+    let mut collector = ExprCollector::new(function);
-    Arc::new(body_syntax_mapping)
+    collector.collect_fn_body(node);
+    collector.into_body_syntax_mapping()
 }
diff --git a/crates/ra_hir/src/expr/scope.rs b/crates/ra_hir/src/expr/scope.rs
index 504a087a3..887ad8dd8 100644
--- a/crates/ra_hir/src/expr/scope.rs
+++ b/crates/ra_hir/src/expr/scope.rs
@@ -338,6 +338,7 @@ pub struct ReferenceDescriptor {
 mod tests {
    use ra_syntax::{SourceFile, algo::find_node_at_offset};
    use test_utils::{extract_offset, assert_eq_text};
+    use ra_arena::ArenaId;
    use crate::expr;
@@ -356,7 +357,10 @@ mod tests {
        let file = SourceFile::parse(&code);
        let marker: &ast::PathExpr = find_node_at_offset(file.syntax(), off).unwrap();
        let fn_def: &ast::FnDef = find_node_at_offset(file.syntax(), off).unwrap();
-        let body_hir = expr::collect_fn_body_syntax(fn_def);
+        let irrelevant_function = Function {
+            id: crate::ids::FunctionId::from_raw(0.into()),
+        };
+        let body_hir = expr::collect_fn_body_syntax(irrelevant_function, fn_def);
        let scopes = ExprScopes::new(Arc::clone(body_hir.body()));
        let scopes = ScopesWithSyntaxMapping {
            scopes: Arc::new(scopes),
@@ -456,7 +460,10 @@ mod tests {
        let fn_def: &ast::FnDef = find_node_at_offset(file.syntax(), off).unwrap();
        let name_ref: &ast::NameRef = find_node_at_offset(file.syntax(), off).unwrap();
-        let body_hir = expr::collect_fn_body_syntax(fn_def);
+        let irrelevant_function = Function {
+            id: crate::ids::FunctionId::from_raw(0.into()),
+        };
+        let body_hir = expr::collect_fn_body_syntax(irrelevant_function, fn_def);
        let scopes = ExprScopes::new(Arc::clone(body_hir.body()));
        let scopes = ScopesWithSyntaxMapping {
            scopes: Arc::new(scopes),
diff --git a/crates/ra_hir/src/impl_block.rs b/crates/ra_hir/src/impl_block.rs
index 36d72b103..5fa49d456 100644
--- a/crates/ra_hir/src/impl_block.rs
+++ b/crates/ra_hir/src/impl_block.rs
@@ -9,9 +9,11 @@ ast::{self, AstNode}};
 use crate::{
    Const, Type,
    Function, HirFileId,
+    HirDatabase,
    PersistentHirDatabase,
    type_ref::TypeRef,
    ids::LocationCtx,
+    resolve::Resolver,
 };
 use crate::code_model_api::{Module, ModuleSource};
@@ -69,6 +71,10 @@ impl ImplBlock {
        &self.module_impl_blocks.impls[self.impl_id]
    }
+    pub fn module(&self) -> Module {
+        self.module_impl_blocks.module.clone()
+    }
    pub fn target_trait(&self) -> Option<&TypeRef> {
        self.impl_data().target_trait()
    }
@@ -80,6 +86,13 @@ impl ImplBlock {
    pub fn items(&self) -> &[ImplItem] {
        self.impl_data().items()
    }
+    pub fn resolver(&self, db: &impl HirDatabase) -> Resolver {
+        let r = self.module().resolver(db);
+        // FIXME: add generics
+        let r = r.push_impl_block_scope(self.clone());
+        r
+    }
 }
 #[derive(Debug, Clone, PartialEq, Eq)]
@@ -162,25 +175,24 @@ impl_arena_id!(ImplId);
 /// we don't need to do the second step again.
 #[derive(Debug, PartialEq, Eq)]
 pub struct ModuleImplBlocks {
+    module: Module,
    pub(crate) impls: Arena<ImplId, ImplData>,
    impls_by_def: FxHashMap<ImplItem, ImplId>,
 }
 impl ModuleImplBlocks {
-    fn new() -> Self {
-        ModuleImplBlocks {
-            impls: Arena::default(),
-            impls_by_def: FxHashMap::default(),
-        }
-    }
    fn collect(
-        &mut self,
        db: &impl PersistentHirDatabase,
        module: Module,
        source_map: &mut ImplSourceMap,
-    ) {
+    ) -> Self {
-        let (file_id, module_source) = module.definition_source(db);
+        let mut m = ModuleImplBlocks {
+            module,
+            impls: Arena::default(),
+            impls_by_def: FxHashMap::default(),
+        };
+        let (file_id, module_source) = m.module.definition_source(db);
        let file_id: HirFileId = file_id.into();
        let node = match &module_source {
            ModuleSource::SourceFile(node) => node.syntax(),
@@ -191,14 +203,16 @@ impl ModuleImplBlocks {
        };
        for impl_block_ast in node.children().filter_map(ast::ImplBlock::cast) {
-            let impl_block = ImplData::from_ast(db, file_id, module, impl_block_ast);
+            let impl_block = ImplData::from_ast(db, file_id, m.module, impl_block_ast);
-            let id = self.impls.alloc(impl_block);
+            let id = m.impls.alloc(impl_block);
-            for &impl_item in &self.impls[id].items {
+            for &impl_item in &m.impls[id].items {
-                self.impls_by_def.insert(impl_item, id);
+                m.impls_by_def.insert(impl_item, id);
            }
            source_map.insert(id, impl_block_ast);
        }
+        m
    }
 }
@@ -208,8 +222,7 @@ pub(crate) fn impls_in_module_with_source_map_query(
 ) -> (Arc<ModuleImplBlocks>, Arc<ImplSourceMap>) {
    let mut source_map = ImplSourceMap::default();
-    let mut result = ModuleImplBlocks::new();
+    let result = ModuleImplBlocks::collect(db, module, &mut source_map);
-    result.collect(db, module, &mut source_map);
    (Arc::new(result), Arc::new(source_map))
 }
diff --git a/crates/ra_hir/src/resolve.rs b/crates/ra_hir/src/resolve.rs
index 41fcb35bc..b7fbf6df2 100644
--- a/crates/ra_hir/src/resolve.rs
+++ b/crates/ra_hir/src/resolve.rs
@@ -15,7 +15,7 @@ use crate::{
    path::Path,
 };
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Default)]
 pub struct Resolver {
    scopes: Vec<Scope>, // maybe a 'linked list' of scopes? or allow linking a Resolver to a parent Resolver? that's an optimization that might not be necessary, though
 }
@@ -87,6 +87,36 @@ impl Resolver {
        self
    }
+    pub(crate) fn push_generic_params_scope(self, params: Arc<GenericParams>) -> Resolver {
+        self.push_scope(Scope::GenericParams(params))
+    }
+    pub(crate) fn push_impl_block_scope(self, impl_block: ImplBlock) -> Resolver {
+        self.push_scope(Scope::ImplBlockScope(impl_block))
+    }
+    pub(crate) fn push_module_scope(self, item_map: Arc<ItemMap>, module_id: ModuleId) -> Resolver {
+        self.push_scope(Scope::ModuleScope(ModuleItemMap {
+            item_map,
+            module_id,
+        }))
+    }
+    pub(crate) fn push_expr_scope(
+        self,
+        expr_scopes: Arc<ExprScopes>,
+        scope_id: ScopeId,
+    ) -> Resolver {
+        self.push_scope(Scope::ExprScope(ExprScope {
+            expr_scopes,
+            scope_id,
+        }))
+    }
+    pub(crate) fn push_function_params(self, body: Arc<Body>) -> Resolver {
+        self.push_scope(Scope::FunctionParams(body))
+    }
    pub(crate) fn pop_scope(mut self) -> Resolver {
        self.scopes.pop();
        self