Refactor primary IDE API

This introduces the new type -- Semantics.
Semantics maps SyntaxNodes to various semantic info, such as type,
name resolution or macro expansions.

To do so, Semantics maintains a HashMap which maps every node it saw
to the file from which the node originated. This is enough to get all
the necessary hir bits just from syntax.

4 files changed, 480 insertions, 215 deletions

diff --git a/crates/ra_hir/src/lib.rs b/crates/ra_hir/src/lib.rs
index 7a9745ebe..004a2185f 100644
--- a/crates/ra_hir/src/lib.rs
+++ b/crates/ra_hir/src/lib.rs
@@ -26,6 +26,7 @@ macro_rules! impl_froms {
     }
 }
 
+mod semantics;
 pub mod db;
 pub mod source_analyzer;
 pub mod source_binder;
@@ -45,8 +46,8 @@ pub use crate::{
         StructField, Trait, Type, TypeAlias, TypeParam, Union, VariantDef,
     },
     has_source::HasSource,
-    source_analyzer::{PathResolution, ScopeEntryWithSyntax, SourceAnalyzer},
-    source_binder::SourceBinder,
+    semantics::{original_range, Semantics, SemanticsScope},
+    source_analyzer::{PathResolution, ScopeEntryWithSyntax},
 };
 
 pub use hir_def::{
diff --git a/crates/ra_hir/src/semantics.rs b/crates/ra_hir/src/semantics.rs
new file mode 100644
index 000000000..22a7e7588
--- /dev/null
+++ b/crates/ra_hir/src/semantics.rs
@@ -0,0 +1,335 @@
+//! See `Semantics`.
+
+use std::{cell::RefCell, fmt, iter::successors};
+
+use hir_def::{
+    resolver::{self, HasResolver, Resolver},
+    TraitId,
+};
+use ra_db::{FileId, FileRange};
+use ra_syntax::{ast, AstNode, SyntaxNode, SyntaxToken, TextRange, TextUnit};
+use rustc_hash::{FxHashMap, FxHashSet};
+
+use crate::{
+    db::HirDatabase,
+    source_analyzer::{resolve_hir_path, ReferenceDescriptor, SourceAnalyzer},
+    source_binder::{ChildContainer, SourceBinder, ToDef},
+    Function, HirFileId, InFile, Local, MacroDef, Module, Name, Origin, Path, PathResolution,
+    ScopeDef, StructField, Trait, Type, TypeParam, VariantDef,
+};
+use ra_prof::profile;
+
+/// Primary API to get semantic information, like types, from syntax trees.
+pub struct Semantics<'db, DB> {
+    pub db: &'db DB,
+    pub(crate) sb: RefCell<SourceBinder>,
+    cache: RefCell<FxHashMap<SyntaxNode, HirFileId>>,
+}
+
+impl<DB> fmt::Debug for Semantics<'_, DB> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "Semantics {{ ... }}")
+    }
+}
+
+impl<'db, DB: HirDatabase> Semantics<'db, DB> {
+    pub fn new(db: &DB) -> Semantics<DB> {
+        let sb = RefCell::new(SourceBinder::new());
+        Semantics { db, sb, cache: RefCell::default() }
+    }
+
+    pub fn parse(&self, file_id: FileId) -> ast::SourceFile {
+        let tree = self.db.parse(file_id).tree();
+        self.cache(tree.syntax().clone(), file_id.into());
+        tree
+    }
+
+    pub fn expand(&self, macro_call: &ast::MacroCall) -> Option<SyntaxNode> {
+        let macro_call = self.find_file(macro_call.syntax().clone()).with_value(macro_call);
+        let sa = self.analyze2(macro_call.map(|it| it.syntax()), None);
+        let file_id = sa.expand(self.db, macro_call)?;
+        let node = self.db.parse_or_expand(file_id)?;
+        self.cache(node.clone(), file_id);
+        Some(node)
+    }
+
+    pub fn descend_into_macros(&self, token: SyntaxToken) -> SyntaxToken {
+        let parent = token.parent();
+        let parent = self.find_file(parent);
+        let sa = self.analyze2(parent.as_ref(), None);
+
+        let token = successors(Some(parent.with_value(token)), |token| {
+            let macro_call = token.value.ancestors().find_map(ast::MacroCall::cast)?;
+            let tt = macro_call.token_tree()?;
+            if !token.value.text_range().is_subrange(&tt.syntax().text_range()) {
+                return None;
+            }
+            let file_id = sa.expand(self.db, token.with_value(&macro_call))?;
+            let token = file_id.expansion_info(self.db)?.map_token_down(token.as_ref())?;
+
+            self.cache(find_root(&token.value.parent()), token.file_id);
+
+            Some(token)
+        })
+        .last()
+        .unwrap();
+
+        token.value
+    }
+
+    pub fn original_range(&self, node: &SyntaxNode) -> FileRange {
+        let node = self.find_file(node.clone());
+        original_range(self.db, node.as_ref())
+    }
+
+    pub fn ancestors_with_macros(&self, node: SyntaxNode) -> impl Iterator<Item = SyntaxNode> + '_ {
+        let node = self.find_file(node);
+        node.ancestors_with_macros(self.db).map(|it| it.value)
+    }
+
+    pub fn type_of_expr(&self, expr: &ast::Expr) -> Option<Type> {
+        self.analyze(expr.syntax()).type_of(self.db, &expr)
+    }
+
+    pub fn type_of_pat(&self, pat: &ast::Pat) -> Option<Type> {
+        self.analyze(pat.syntax()).type_of_pat(self.db, &pat)
+    }
+
+    pub fn resolve_method_call(&self, call: &ast::MethodCallExpr) -> Option<Function> {
+        self.analyze(call.syntax()).resolve_method_call(call)
+    }
+
+    pub fn resolve_field(&self, field: &ast::FieldExpr) -> Option<StructField> {
+        self.analyze(field.syntax()).resolve_field(field)
+    }
+
+    pub fn resolve_record_field(&self, field: &ast::RecordField) -> Option<StructField> {
+        self.analyze(field.syntax()).resolve_record_field(field)
+    }
+
+    pub fn resolve_record_literal(&self, record_lit: &ast::RecordLit) -> Option<VariantDef> {
+        self.analyze(record_lit.syntax()).resolve_record_literal(record_lit)
+    }
+
+    pub fn resolve_record_pattern(&self, record_pat: &ast::RecordPat) -> Option<VariantDef> {
+        self.analyze(record_pat.syntax()).resolve_record_pattern(record_pat)
+    }
+
+    pub fn resolve_macro_call(&self, macro_call: &ast::MacroCall) -> Option<MacroDef> {
+        let sa = self.analyze(macro_call.syntax());
+        let macro_call = self.find_file(macro_call.syntax().clone()).with_value(macro_call);
+        sa.resolve_macro_call(self.db, macro_call)
+    }
+
+    pub fn resolve_path(&self, path: &ast::Path) -> Option<PathResolution> {
+        self.analyze(path.syntax()).resolve_path(self.db, path)
+    }
+
+    // FIXME: use this instead?
+    // pub fn resolve_name_ref(&self, name_ref: &ast::NameRef) -> Option<???>;
+
+    pub fn to_def<T: ToDef + Clone>(&self, src: &T) -> Option<T::Def> {
+        let src = self.find_file(src.syntax().clone()).with_value(src.clone());
+        let mut sb = self.sb.borrow_mut();
+        T::to_def(self.db, &mut sb, src)
+    }
+
+    pub fn to_module_def(&self, file: FileId) -> Option<Module> {
+        let mut sb = self.sb.borrow_mut();
+        sb.to_module_def(self.db, file)
+    }
+
+    pub fn scope(&self, node: &SyntaxNode) -> SemanticsScope<'db, DB> {
+        let node = self.find_file(node.clone());
+        let resolver = self.analyze2(node.as_ref(), None).resolver;
+        SemanticsScope { db: self.db, resolver }
+    }
+
+    pub fn scope_at_offset(&self, node: &SyntaxNode, offset: TextUnit) -> SemanticsScope<'db, DB> {
+        let node = self.find_file(node.clone());
+        let resolver = self.analyze2(node.as_ref(), Some(offset)).resolver;
+        SemanticsScope { db: self.db, resolver }
+    }
+
+    pub fn scope_for_def(&self, def: Trait) -> SemanticsScope<'db, DB> {
+        let resolver = def.id.resolver(self.db);
+        SemanticsScope { db: self.db, resolver }
+    }
+
+    // FIXME: we only use this in `inline_local_variable` assist, ideally, we
+    // should switch to general reference search infra there.
+    pub fn find_all_refs(&self, pat: &ast::BindPat) -> Vec<ReferenceDescriptor> {
+        self.analyze(pat.syntax()).find_all_refs(pat)
+    }
+
+    fn analyze(&self, node: &SyntaxNode) -> SourceAnalyzer {
+        let src = self.find_file(node.clone());
+        self.analyze2(src.as_ref(), None)
+    }
+
+    fn analyze2(&self, src: InFile<&SyntaxNode>, offset: Option<TextUnit>) -> SourceAnalyzer {
+        let _p = profile("Semantics::analyze2");
+
+        let container = match self.sb.borrow_mut().find_container(self.db, src) {
+            Some(it) => it,
+            None => return SourceAnalyzer::new_for_resolver(Resolver::default(), src),
+        };
+
+        let resolver = match container {
+            ChildContainer::DefWithBodyId(def) => {
+                return SourceAnalyzer::new_for_body(self.db, def, src, offset)
+            }
+            ChildContainer::TraitId(it) => it.resolver(self.db),
+            ChildContainer::ImplId(it) => it.resolver(self.db),
+            ChildContainer::ModuleId(it) => it.resolver(self.db),
+            ChildContainer::EnumId(it) => it.resolver(self.db),
+            ChildContainer::VariantId(it) => it.resolver(self.db),
+            ChildContainer::GenericDefId(it) => it.resolver(self.db),
+        };
+        SourceAnalyzer::new_for_resolver(resolver, src)
+    }
+
+    fn cache(&self, root_node: SyntaxNode, file_id: HirFileId) {
+        assert!(root_node.parent().is_none());
+        let mut cache = self.cache.borrow_mut();
+        let prev = cache.insert(root_node, file_id);
+        assert!(prev == None || prev == Some(file_id))
+    }
+
+    pub fn assert_contains_node(&self, node: &SyntaxNode) {
+        self.find_file(node.clone());
+    }
+
+    fn lookup(&self, root_node: &SyntaxNode) -> Option<HirFileId> {
+        let cache = self.cache.borrow();
+        cache.get(root_node).copied()
+    }
+
+    fn find_file(&self, node: SyntaxNode) -> InFile<SyntaxNode> {
+        let root_node = find_root(&node);
+        let file_id = self.lookup(&root_node).unwrap_or_else(|| {
+            panic!(
+                "\n\nFailed to lookup {:?} in this Semantics.\n\
+                 Make sure to use only query nodes, derived from this instance of Semantics.\n\
+                 root node:   {:?}\n\
+                 known nodes: {}\n\n",
+                node,
+                root_node,
+                self.cache
+                    .borrow()
+                    .keys()
+                    .map(|it| format!("{:?}", it))
+                    .collect::<Vec<_>>()
+                    .join(", ")
+            )
+        });
+        InFile::new(file_id, node)
+    }
+}
+
+fn find_root(node: &SyntaxNode) -> SyntaxNode {
+    node.ancestors().last().unwrap()
+}
+
+pub struct SemanticsScope<'a, DB> {
+    pub db: &'a DB,
+    resolver: Resolver,
+}
+
+impl<'a, DB: HirDatabase> SemanticsScope<'a, DB> {
+    pub fn module(&self) -> Option<Module> {
+        Some(Module { id: self.resolver.module()? })
+    }
+
+    /// Note: `FxHashSet<TraitId>` should be treated as an opaque type, passed into `Type
+    // FIXME: rename to visible_traits to not repeat scope?
+    pub fn traits_in_scope(&self) -> FxHashSet<TraitId> {
+        let resolver = &self.resolver;
+        resolver.traits_in_scope(self.db)
+    }
+
+    pub fn process_all_names(&self, f: &mut dyn FnMut(Name, ScopeDef)) {
+        let resolver = &self.resolver;
+
+        resolver.process_all_names(self.db, &mut |name, def| {
+            let def = match def {
+                resolver::ScopeDef::PerNs(it) => it.into(),
+                resolver::ScopeDef::ImplSelfType(it) => ScopeDef::ImplSelfType(it.into()),
+                resolver::ScopeDef::AdtSelfType(it) => ScopeDef::AdtSelfType(it.into()),
+                resolver::ScopeDef::GenericParam(id) => ScopeDef::GenericParam(TypeParam { id }),
+                resolver::ScopeDef::Local(pat_id) => {
+                    let parent = resolver.body_owner().unwrap().into();
+                    ScopeDef::Local(Local { parent, pat_id })
+                }
+            };
+            f(name, def)
+        })
+    }
+
+    pub fn resolve_hir_path(&self, path: &Path) -> Option<PathResolution> {
+        resolve_hir_path(self.db, &self.resolver, path)
+    }
+}
+
+// FIXME: Change `HasSource` trait to work with `Semantics` and remove this?
+pub fn original_range(db: &impl HirDatabase, node: InFile<&SyntaxNode>) -> FileRange {
+    if let Some((range, Origin::Call)) = original_range_and_origin(db, node) {
+        return range;
+    }
+
+    if let Some(expansion) = node.file_id.expansion_info(db) {
+        if let Some(call_node) = expansion.call_node() {
+            return FileRange {
+                file_id: call_node.file_id.original_file(db),
+                range: call_node.value.text_range(),
+            };
+        }
+    }
+
+    FileRange { file_id: node.file_id.original_file(db), range: node.value.text_range() }
+}
+
+fn original_range_and_origin(
+    db: &impl HirDatabase,
+    node: InFile<&SyntaxNode>,
+) -> Option<(FileRange, Origin)> {
+    let expansion = node.file_id.expansion_info(db)?;
+
+    // the input node has only one token ?
+    let single = node.value.first_token()? == node.value.last_token()?;
+
+    // FIXME: We should handle recurside macro expansions
+    let (range, origin) = node.value.descendants().find_map(|it| {
+        let first = it.first_token()?;
+        let last = it.last_token()?;
+
+        if !single && first == last {
+            return None;
+        }
+
+        // Try to map first and last tokens of node, and, if success, return the union range of mapped tokens
+        let (first, first_origin) = expansion.map_token_up(node.with_value(&first))?;
+        let (last, last_origin) = expansion.map_token_up(node.with_value(&last))?;
+
+        if first.file_id != last.file_id || first_origin != last_origin {
+            return None;
+        }
+
+        // FIXME: Add union method in TextRange
+        Some((
+            first.with_value(union_range(first.value.text_range(), last.value.text_range())),
+            first_origin,
+        ))
+    })?;
+
+    return Some((
+        FileRange { file_id: range.file_id.original_file(db), range: range.value },
+        origin,
+    ));
+
+    fn union_range(a: TextRange, b: TextRange) -> TextRange {
+        let start = a.start().min(b.start());
+        let end = a.end().max(b.end());
+        TextRange::from_to(start, end)
+    }
+}
diff --git a/crates/ra_hir/src/source_analyzer.rs b/crates/ra_hir/src/source_analyzer.rs
index efa3f8a79..bff1ecd14 100644
--- a/crates/ra_hir/src/source_analyzer.rs
+++ b/crates/ra_hir/src/source_analyzer.rs
@@ -14,29 +14,27 @@ use hir_def::{
         BodySourceMap,
     },
     expr::{ExprId, PatId},
-    resolver::{self, resolver_for_scope, Resolver, TypeNs, ValueNs},
-    AsMacroCall, DefWithBodyId, TraitId,
+    resolver::{resolver_for_scope, Resolver, TypeNs, ValueNs},
+    AsMacroCall, DefWithBodyId,
 };
-use hir_expand::{hygiene::Hygiene, name::AsName, HirFileId, InFile, MacroCallId};
+use hir_expand::{hygiene::Hygiene, name::AsName, HirFileId, InFile};
 use hir_ty::{InEnvironment, InferenceResult, TraitEnvironment};
 use ra_syntax::{
     ast::{self, AstNode},
-    AstPtr, SyntaxNode, SyntaxNodePtr, SyntaxToken, TextRange, TextUnit,
+    AstPtr, SyntaxNode, SyntaxNodePtr, TextRange, TextUnit,
 };
-use rustc_hash::FxHashSet;
 
 use crate::{
-    db::HirDatabase, Adt, Const, DefWithBody, EnumVariant, Function, Local, MacroDef, Name, Path,
-    ScopeDef, Static, Struct, Trait, Type, TypeAlias, TypeParam,
+    db::HirDatabase, Adt, Const, EnumVariant, Function, Local, MacroDef, Name, Path, Static,
+    Struct, Trait, Type, TypeAlias, TypeParam,
 };
 
 /// `SourceAnalyzer` is a convenience wrapper which exposes HIR API in terms of
 /// original source files. It should not be used inside the HIR itself.
 #[derive(Debug)]
-pub struct SourceAnalyzer {
+pub(crate) struct SourceAnalyzer {
     file_id: HirFileId,
-    resolver: Resolver,
-    body_owner: Option<DefWithBody>,
+    pub(crate) resolver: Resolver,
     body_source_map: Option<Arc<BodySourceMap>>,
     infer: Option<Arc<InferenceResult>>,
     scopes: Option<Arc<ExprScopes>>,
@@ -77,35 +75,7 @@ pub struct ReferenceDescriptor {
     pub name: String,
 }
 
-#[derive(Debug)]
-pub struct Expansion {
-    macro_call_id: MacroCallId,
-}
-
-impl Expansion {
-    pub fn map_token_down(
-        &self,
-        db: &impl HirDatabase,
-        token: InFile<&SyntaxToken>,
-    ) -> Option<InFile<SyntaxToken>> {
-        let exp_info = self.file_id().expansion_info(db)?;
-        exp_info.map_token_down(token)
-    }
-
-    pub fn file_id(&self) -> HirFileId {
-        self.macro_call_id.as_file()
-    }
-}
-
 impl SourceAnalyzer {
-    pub fn new(
-        db: &impl HirDatabase,
-        node: InFile<&SyntaxNode>,
-        offset: Option<TextUnit>,
-    ) -> SourceAnalyzer {
-        crate::source_binder::SourceBinder::new(db).analyze(node, offset)
-    }
-
     pub(crate) fn new_for_body(
         db: &impl HirDatabase,
         def: DefWithBodyId,
@@ -121,7 +91,6 @@ impl SourceAnalyzer {
         let resolver = resolver_for_scope(db, def, scope);
         SourceAnalyzer {
             resolver,
-            body_owner: Some(def.into()),
             body_source_map: Some(source_map),
             infer: Some(db.infer(def)),
             scopes: Some(scopes),
@@ -135,7 +104,6 @@ impl SourceAnalyzer {
     ) -> SourceAnalyzer {
         SourceAnalyzer {
             resolver,
-            body_owner: None,
             body_source_map: None,
             infer: None,
             scopes: None,
@@ -143,10 +111,6 @@ impl SourceAnalyzer {
         }
     }
 
-    pub fn module(&self) -> Option<crate::code_model::Module> {
-        Some(crate::code_model::Module { id: self.resolver.module()? })
-    }
-
     fn expr_id(&self, expr: &ast::Expr) -> Option<ExprId> {
         let src = InFile { file_id: self.file_id, value: expr };
         self.body_source_map.as_ref()?.node_expr(src)
@@ -180,7 +144,7 @@ impl SourceAnalyzer {
         TraitEnvironment::lower(db, &self.resolver)
     }
 
-    pub fn type_of(&self, db: &impl HirDatabase, expr: &ast::Expr) -> Option<Type> {
+    pub(crate) fn type_of(&self, db: &impl HirDatabase, expr: &ast::Expr) -> Option<Type> {
         let expr_id = if let Some(expr) = self.expand_expr(db, InFile::new(self.file_id, expr)) {
             self.body_source_map.as_ref()?.node_expr(expr.as_ref())?
         } else {
@@ -192,24 +156,27 @@ impl SourceAnalyzer {
         Some(Type { krate: self.resolver.krate()?, ty: InEnvironment { value: ty, environment } })
     }
 
-    pub fn type_of_pat(&self, db: &impl HirDatabase, pat: &ast::Pat) -> Option<Type> {
+    pub(crate) fn type_of_pat(&self, db: &impl HirDatabase, pat: &ast::Pat) -> Option<Type> {
         let pat_id = self.pat_id(pat)?;
         let ty = self.infer.as_ref()?[pat_id].clone();
         let environment = self.trait_env(db);
         Some(Type { krate: self.resolver.krate()?, ty: InEnvironment { value: ty, environment } })
     }
 
-    pub fn resolve_method_call(&self, call: &ast::MethodCallExpr) -> Option<Function> {
+    pub(crate) fn resolve_method_call(&self, call: &ast::MethodCallExpr) -> Option<Function> {
         let expr_id = self.expr_id(&call.clone().into())?;
         self.infer.as_ref()?.method_resolution(expr_id).map(Function::from)
     }
 
-    pub fn resolve_field(&self, field: &ast::FieldExpr) -> Option<crate::StructField> {
+    pub(crate) fn resolve_field(&self, field: &ast::FieldExpr) -> Option<crate::StructField> {
         let expr_id = self.expr_id(&field.clone().into())?;
         self.infer.as_ref()?.field_resolution(expr_id).map(|it| it.into())
     }
 
-    pub fn resolve_record_field(&self, field: &ast::RecordField) -> Option<crate::StructField> {
+    pub(crate) fn resolve_record_field(
+        &self,
+        field: &ast::RecordField,
+    ) -> Option<crate::StructField> {
         let expr_id = match field.expr() {
             Some(it) => self.expr_id(&it)?,
             None => {
@@ -220,17 +187,23 @@ impl SourceAnalyzer {
         self.infer.as_ref()?.record_field_resolution(expr_id).map(|it| it.into())
     }
 
-    pub fn resolve_record_literal(&self, record_lit: &ast::RecordLit) -> Option<crate::VariantDef> {
+    pub(crate) fn resolve_record_literal(
+        &self,
+        record_lit: &ast::RecordLit,
+    ) -> Option<crate::VariantDef> {
         let expr_id = self.expr_id(&record_lit.clone().into())?;
         self.infer.as_ref()?.variant_resolution_for_expr(expr_id).map(|it| it.into())
     }
 
-    pub fn resolve_record_pattern(&self, record_pat: &ast::RecordPat) -> Option<crate::VariantDef> {
+    pub(crate) fn resolve_record_pattern(
+        &self,
+        record_pat: &ast::RecordPat,
+    ) -> Option<crate::VariantDef> {
         let pat_id = self.pat_id(&record_pat.clone().into())?;
         self.infer.as_ref()?.variant_resolution_for_pat(pat_id).map(|it| it.into())
     }
 
-    pub fn resolve_macro_call(
+    pub(crate) fn resolve_macro_call(
         &self,
         db: &impl HirDatabase,
         macro_call: InFile<&ast::MacroCall>,
@@ -240,52 +213,11 @@ impl SourceAnalyzer {
         self.resolver.resolve_path_as_macro(db, path.mod_path()).map(|it| it.into())
     }
 
-    pub fn resolve_hir_path(
+    pub(crate) fn resolve_path(
         &self,
         db: &impl HirDatabase,
-        path: &crate::Path,
+        path: &ast::Path,
     ) -> Option<PathResolution> {
-        let types =
-            self.resolver.resolve_path_in_type_ns_fully(db, path.mod_path()).map(|ty| match ty {
-                TypeNs::SelfType(it) => PathResolution::SelfType(it.into()),
-                TypeNs::GenericParam(id) => PathResolution::TypeParam(TypeParam { id }),
-                TypeNs::AdtSelfType(it) | TypeNs::AdtId(it) => {
-                    PathResolution::Def(Adt::from(it).into())
-                }
-                TypeNs::EnumVariantId(it) => PathResolution::Def(EnumVariant::from(it).into()),
-                TypeNs::TypeAliasId(it) => PathResolution::Def(TypeAlias::from(it).into()),
-                TypeNs::BuiltinType(it) => PathResolution::Def(it.into()),
-                TypeNs::TraitId(it) => PathResolution::Def(Trait::from(it).into()),
-            });
-        let values =
-            self.resolver.resolve_path_in_value_ns_fully(db, path.mod_path()).and_then(|val| {
-                let res = match val {
-                    ValueNs::LocalBinding(pat_id) => {
-                        let var = Local { parent: self.body_owner?, pat_id };
-                        PathResolution::Local(var)
-                    }
-                    ValueNs::FunctionId(it) => PathResolution::Def(Function::from(it).into()),
-                    ValueNs::ConstId(it) => PathResolution::Def(Const::from(it).into()),
-                    ValueNs::StaticId(it) => PathResolution::Def(Static::from(it).into()),
-                    ValueNs::StructId(it) => PathResolution::Def(Struct::from(it).into()),
-                    ValueNs::EnumVariantId(it) => PathResolution::Def(EnumVariant::from(it).into()),
-                };
-                Some(res)
-            });
-
-        let items = self
-            .resolver
-            .resolve_module_path_in_items(db, path.mod_path())
-            .take_types()
-            .map(|it| PathResolution::Def(it.into()));
-        types.or(values).or(items).or_else(|| {
-            self.resolver
-                .resolve_path_as_macro(db, path.mod_path())
-                .map(|def| PathResolution::Macro(def.into()))
-        })
-    }
-
-    pub fn resolve_path(&self, db: &impl HirDatabase, path: &ast::Path) -> Option<PathResolution> {
         if let Some(path_expr) = path.syntax().parent().and_then(ast::PathExpr::cast) {
             let expr_id = self.expr_id(&path_expr.into())?;
             if let Some(assoc) = self.infer.as_ref()?.assoc_resolutions_for_expr(expr_id) {
@@ -300,7 +232,7 @@ impl SourceAnalyzer {
         }
         // This must be a normal source file rather than macro file.
         let hir_path = crate::Path::from_ast(path.clone())?;
-        self.resolve_hir_path(db, &hir_path)
+        resolve_hir_path(db, &self.resolver, &hir_path)
     }
 
     fn resolve_local_name(&self, name_ref: &ast::NameRef) -> Option<ScopeEntryWithSyntax> {
@@ -315,25 +247,9 @@ impl SourceAnalyzer {
         })
     }
 
-    pub fn process_all_names(&self, db: &impl HirDatabase, f: &mut dyn FnMut(Name, ScopeDef)) {
-        self.resolver.process_all_names(db, &mut |name, def| {
-            let def = match def {
-                resolver::ScopeDef::PerNs(it) => it.into(),
-                resolver::ScopeDef::ImplSelfType(it) => ScopeDef::ImplSelfType(it.into()),
-                resolver::ScopeDef::AdtSelfType(it) => ScopeDef::AdtSelfType(it.into()),
-                resolver::ScopeDef::GenericParam(id) => ScopeDef::GenericParam(TypeParam { id }),
-                resolver::ScopeDef::Local(pat_id) => {
-                    let parent = self.resolver.body_owner().unwrap().into();
-                    ScopeDef::Local(Local { parent, pat_id })
-                }
-            };
-            f(name, def)
-        })
-    }
-
     // FIXME: we only use this in `inline_local_variable` assist, ideally, we
     // should switch to general reference search infra there.
-    pub fn find_all_refs(&self, pat: &ast::BindPat) -> Vec<ReferenceDescriptor> {
+    pub(crate) fn find_all_refs(&self, pat: &ast::BindPat) -> Vec<ReferenceDescriptor> {
         let fn_def = pat.syntax().ancestors().find_map(ast::FnDef::cast).unwrap();
         let ptr = Either::Left(AstPtr::new(&ast::Pat::from(pat.clone())));
         fn_def
@@ -351,19 +267,14 @@ impl SourceAnalyzer {
             .collect()
     }
 
-    /// Note: `FxHashSet<TraitId>` should be treated as an opaque type, passed into `Type
-    pub fn traits_in_scope(&self, db: &impl HirDatabase) -> FxHashSet<TraitId> {
-        self.resolver.traits_in_scope(db)
-    }
-
-    pub fn expand(
+    pub(crate) fn expand(
         &self,
         db: &impl HirDatabase,
         macro_call: InFile<&ast::MacroCall>,
-    ) -> Option<Expansion> {
+    ) -> Option<HirFileId> {
         let macro_call_id =
             macro_call.as_call_id(db, |path| self.resolver.resolve_path_as_macro(db, &path))?;
-        Some(Expansion { macro_call_id })
+        Some(macro_call_id.as_file())
     }
 }
 
@@ -409,6 +320,47 @@ fn scope_for_offset(
         })
 }
 
+pub(crate) fn resolve_hir_path(
+    db: &impl HirDatabase,
+    resolver: &Resolver,
+    path: &crate::Path,
+) -> Option<PathResolution> {
+    let types = resolver.resolve_path_in_type_ns_fully(db, path.mod_path()).map(|ty| match ty {
+        TypeNs::SelfType(it) => PathResolution::SelfType(it.into()),
+        TypeNs::GenericParam(id) => PathResolution::TypeParam(TypeParam { id }),
+        TypeNs::AdtSelfType(it) | TypeNs::AdtId(it) => PathResolution::Def(Adt::from(it).into()),
+        TypeNs::EnumVariantId(it) => PathResolution::Def(EnumVariant::from(it).into()),
+        TypeNs::TypeAliasId(it) => PathResolution::Def(TypeAlias::from(it).into()),
+        TypeNs::BuiltinType(it) => PathResolution::Def(it.into()),
+        TypeNs::TraitId(it) => PathResolution::Def(Trait::from(it).into()),
+    });
+    let body_owner = resolver.body_owner();
+    let values = resolver.resolve_path_in_value_ns_fully(db, path.mod_path()).and_then(|val| {
+        let res = match val {
+            ValueNs::LocalBinding(pat_id) => {
+                let var = Local { parent: body_owner?.into(), pat_id };
+                PathResolution::Local(var)
+            }
+            ValueNs::FunctionId(it) => PathResolution::Def(Function::from(it).into()),
+            ValueNs::ConstId(it) => PathResolution::Def(Const::from(it).into()),
+            ValueNs::StaticId(it) => PathResolution::Def(Static::from(it).into()),
+            ValueNs::StructId(it) => PathResolution::Def(Struct::from(it).into()),
+            ValueNs::EnumVariantId(it) => PathResolution::Def(EnumVariant::from(it).into()),
+        };
+        Some(res)
+    });
+
+    let items = resolver
+        .resolve_module_path_in_items(db, path.mod_path())
+        .take_types()
+        .map(|it| PathResolution::Def(it.into()));
+    types.or(values).or(items).or_else(|| {
+        resolver
+            .resolve_path_as_macro(db, path.mod_path())
+            .map(|def| PathResolution::Macro(def.into()))
+    })
+}
+
 // XXX: during completion, cursor might be outside of any particular
 // expression. Try to figure out the correct scope...
 fn adjust(
diff --git a/crates/ra_hir/src/source_binder.rs b/crates/ra_hir/src/source_binder.rs
index f3150f578..0b8a641f9 100644
--- a/crates/ra_hir/src/source_binder.rs
+++ b/crates/ra_hir/src/source_binder.rs
@@ -5,112 +5,85 @@ use hir_def::{
     child_by_source::ChildBySource,
     dyn_map::DynMap,
     keys::{self, Key},
-    resolver::{HasResolver, Resolver},
     ConstId, DefWithBodyId, EnumId, EnumVariantId, FunctionId, GenericDefId, ImplId, ModuleId,
     StaticId, StructFieldId, StructId, TraitId, TypeAliasId, UnionId, VariantId,
 };
 use hir_expand::{name::AsName, AstId, InFile, MacroDefId, MacroDefKind};
+use ra_db::FileId;
 use ra_prof::profile;
 use ra_syntax::{
     ast::{self, NameOwner},
-    match_ast, AstNode, SyntaxNode, TextUnit,
+    match_ast, AstNode, SyntaxNode,
 };
 use rustc_hash::FxHashMap;
 
-use crate::{db::HirDatabase, Local, Module, SourceAnalyzer, TypeParam};
-use ra_db::FileId;
+use crate::{db::HirDatabase, Local, Module, TypeParam};
 
-pub struct SourceBinder<'a, DB> {
-    pub db: &'a DB,
+pub struct SourceBinder {
     child_by_source_cache: FxHashMap<ChildContainer, DynMap>,
 }
 
-impl<DB: HirDatabase> SourceBinder<'_, DB> {
-    pub fn new(db: &DB) -> SourceBinder<DB> {
-        SourceBinder { db, child_by_source_cache: FxHashMap::default() }
-    }
-
-    pub fn analyze(
-        &mut self,
-        src: InFile<&SyntaxNode>,
-        offset: Option<TextUnit>,
-    ) -> SourceAnalyzer {
-        let _p = profile("SourceBinder::analyzer");
-        let container = match self.find_container(src) {
-            Some(it) => it,
-            None => return SourceAnalyzer::new_for_resolver(Resolver::default(), src),
-        };
-
-        let resolver = match container {
-            ChildContainer::DefWithBodyId(def) => {
-                return SourceAnalyzer::new_for_body(self.db, def, src, offset)
-            }
-            ChildContainer::TraitId(it) => it.resolver(self.db),
-            ChildContainer::ImplId(it) => it.resolver(self.db),
-            ChildContainer::ModuleId(it) => it.resolver(self.db),
-            ChildContainer::EnumId(it) => it.resolver(self.db),
-            ChildContainer::VariantId(it) => it.resolver(self.db),
-            ChildContainer::GenericDefId(it) => it.resolver(self.db),
-        };
-        SourceAnalyzer::new_for_resolver(resolver, src)
+impl SourceBinder {
+    pub(crate) fn new() -> SourceBinder {
+        SourceBinder { child_by_source_cache: FxHashMap::default() }
     }
 
-    pub fn to_def<T: ToDef>(&mut self, src: InFile<T>) -> Option<T::Def> {
-        T::to_def(self, src)
-    }
-
-    pub fn to_module_def(&mut self, file: FileId) -> Option<Module> {
+    pub(crate) fn to_module_def(&mut self, db: &impl HirDatabase, file: FileId) -> Option<Module> {
         let _p = profile("SourceBinder::to_module_def");
-        let (krate, local_id) = self.db.relevant_crates(file).iter().find_map(|&crate_id| {
-            let crate_def_map = self.db.crate_def_map(crate_id);
+        let (krate, local_id) = db.relevant_crates(file).iter().find_map(|&crate_id| {
+            let crate_def_map = db.crate_def_map(crate_id);
             let local_id = crate_def_map.modules_for_file(file).next()?;
             Some((crate_id, local_id))
         })?;
         Some(Module { id: ModuleId { krate, local_id } })
     }
 
-    fn to_id<T: ToId>(&mut self, src: InFile<T>) -> Option<T::ID> {
-        T::to_id(self, src)
+    fn to_id<T: ToId>(&mut self, db: &impl HirDatabase, src: InFile<T>) -> Option<T::ID> {
+        T::to_id(db, self, src)
     }
 
-    fn find_container(&mut self, src: InFile<&SyntaxNode>) -> Option<ChildContainer> {
-        for container in src.cloned().ancestors_with_macros(self.db).skip(1) {
+    pub(crate) fn find_container(
+        &mut self,
+        db: &impl HirDatabase,
+        src: InFile<&SyntaxNode>,
+    ) -> Option<ChildContainer> {
+        for container in src.cloned().ancestors_with_macros(db).skip(1) {
             let res: ChildContainer = match_ast! {
                 match (container.value) {
                     ast::TraitDef(it) => {
-                        let def: TraitId = self.to_id(container.with_value(it))?;
+                        let def: TraitId = self.to_id(db, container.with_value(it))?;
                         def.into()
                     },
                     ast::ImplBlock(it) => {
-                        let def: ImplId = self.to_id(container.with_value(it))?;
+                        let def: ImplId = self.to_id(db, container.with_value(it))?;
                         def.into()
                     },
                     ast::FnDef(it) => {
-                        let def: FunctionId = self.to_id(container.with_value(it))?;
+                        let def: FunctionId = self.to_id(db, container.with_value(it))?;
                         DefWithBodyId::from(def).into()
                     },
                     ast::StaticDef(it) => {
-                        let def: StaticId = self.to_id(container.with_value(it))?;
+                        let def: StaticId = self.to_id(db, container.with_value(it))?;
                         DefWithBodyId::from(def).into()
                     },
                     ast::ConstDef(it) => {
-                        let def: ConstId = self.to_id(container.with_value(it))?;
+                        let def: ConstId = self.to_id(db, container.with_value(it))?;
                         DefWithBodyId::from(def).into()
                     },
                     ast::EnumDef(it) => {
-                        let def: EnumId = self.to_id(container.with_value(it))?;
+                        let def: EnumId = self.to_id(db, container.with_value(it))?;
                         def.into()
                     },
                     ast::StructDef(it) => {
-                        let def: StructId = self.to_id(container.with_value(it))?;
+                        let def: StructId = self.to_id(db, container.with_value(it))?;
                         VariantId::from(def).into()
                     },
                     ast::UnionDef(it) => {
-                        let def: UnionId = self.to_id(container.with_value(it))?;
+                        let def: UnionId = self.to_id(db, container.with_value(it))?;
                         VariantId::from(def).into()
                     },
                     ast::Module(it) => {
-                        let def: ModuleId = self.to_id(container.with_value(it))?;
+                        let def: ModuleId = self.to_id(db, container.with_value(it))?;
                         def.into()
                     },
                     _ => { continue },
@@ -119,12 +92,11 @@ impl<DB: HirDatabase> SourceBinder<'_, DB> {
             return Some(res);
         }
 
-        let c = self.to_module_def(src.file_id.original_file(self.db))?;
+        let c = self.to_module_def(db, src.file_id.original_file(db))?;
         Some(c.id.into())
     }
 
-    fn child_by_source(&mut self, container: ChildContainer) -> &DynMap {
-        let db = self.db;
+    fn child_by_source(&mut self, db: &impl HirDatabase, container: ChildContainer) -> &DynMap {
         self.child_by_source_cache.entry(container).or_insert_with(|| match container {
             ChildContainer::DefWithBodyId(it) => it.child_by_source(db),
             ChildContainer::ModuleId(it) => it.child_by_source(db),
@@ -137,16 +109,20 @@ impl<DB: HirDatabase> SourceBinder<'_, DB> {
     }
 }
 
-pub trait ToId: Sized {
+pub(crate) trait ToId: Sized {
     type ID: Sized + Copy + 'static;
-    fn to_id<DB: HirDatabase>(sb: &mut SourceBinder<'_, DB>, src: InFile<Self>)
-        -> Option<Self::ID>;
+    fn to_id<DB: HirDatabase>(
+        db: &DB,
+        sb: &mut SourceBinder,
+        src: InFile<Self>,
+    ) -> Option<Self::ID>;
 }
 
 pub trait ToDef: Sized + AstNode + 'static {
     type Def;
     fn to_def<DB: HirDatabase>(
-        sb: &mut SourceBinder<'_, DB>,
+        db: &DB,
+        sb: &mut SourceBinder,
         src: InFile<Self>,
     ) -> Option<Self::Def>;
 }
@@ -155,9 +131,9 @@ macro_rules! to_def_impls {
     ($(($def:path, $ast:path)),* ,) => {$(
         impl ToDef for $ast {
             type Def = $def;
-            fn to_def<DB: HirDatabase>(sb: &mut SourceBinder<'_, DB>, src: InFile<Self>)
+            fn to_def<DB: HirDatabase>(db: &DB, sb: &mut SourceBinder, src: InFile<Self>)
                 -> Option<Self::Def>
-            { sb.to_id(src).map(Into::into) }
+            { sb.to_id(db, src).map(Into::into) }
         }
     )*}
 }
@@ -179,7 +155,7 @@ to_def_impls![
 ];
 
 #[derive(Clone, Copy, PartialEq, Eq, Hash, Debug)]
-enum ChildContainer {
+pub(crate) enum ChildContainer {
     DefWithBodyId(DefWithBodyId),
     ModuleId(ModuleId),
     TraitId(TraitId),
@@ -201,7 +177,7 @@ impl_froms! {
     GenericDefId
 }
 
-pub trait ToIdByKey: Sized + AstNode + 'static {
+pub(crate) trait ToIdByKey: Sized + AstNode + 'static {
     type ID: Sized + Copy + 'static;
     const KEY: Key<Self, Self::ID>;
 }
@@ -209,11 +185,11 @@ pub trait ToIdByKey: Sized + AstNode + 'static {
 impl<T: ToIdByKey> ToId for T {
     type ID = <T as ToIdByKey>::ID;
     fn to_id<DB: HirDatabase>(
-        sb: &mut SourceBinder<'_, DB>,
+        db: &DB,
+        sb: &mut SourceBinder,
         src: InFile<Self>,
     ) -> Option<Self::ID> {
-        let container = sb.find_container(src.as_ref().map(|it| it.syntax()))?;
-        let db = sb.db;
+        let container = sb.find_container(db, src.as_ref().map(|it| it.syntax()))?;
         let dyn_map =
             &*sb.child_by_source_cache.entry(container).or_insert_with(|| match container {
                 ChildContainer::DefWithBodyId(it) => it.child_by_source(db),
@@ -255,15 +231,15 @@ to_id_key_impls![
 impl ToId for ast::MacroCall {
     type ID = MacroDefId;
     fn to_id<DB: HirDatabase>(
-        sb: &mut SourceBinder<'_, DB>,
+        db: &DB,
+        sb: &mut SourceBinder,
         src: InFile<Self>,
     ) -> Option<Self::ID> {
         let kind = MacroDefKind::Declarative;
 
-        let krate = sb.to_module_def(src.file_id.original_file(sb.db))?.id.krate;
+        let krate = sb.to_module_def(db, src.file_id.original_file(db))?.id.krate;
 
-        let ast_id =
-            Some(AstId::new(src.file_id, sb.db.ast_id_map(src.file_id).ast_id(&src.value)));
+        let ast_id = Some(AstId::new(src.file_id, db.ast_id_map(src.file_id).ast_id(&src.value)));
 
         Some(MacroDefId { krate: Some(krate), ast_id, kind })
     }
@@ -272,20 +248,20 @@ impl ToId for ast::MacroCall {
 impl ToDef for ast::BindPat {
     type Def = Local;
 
-    fn to_def<DB: HirDatabase>(sb: &mut SourceBinder<'_, DB>, src: InFile<Self>) -> Option<Local> {
+    fn to_def<DB: HirDatabase>(db: &DB, sb: &mut SourceBinder, src: InFile<Self>) -> Option<Local> {
         let file_id = src.file_id;
         let parent: DefWithBodyId = src.value.syntax().ancestors().find_map(|it| {
             let res = match_ast! {
                 match it {
-                    ast::ConstDef(value) => { sb.to_id(InFile { value, file_id})?.into() },
-                    ast::StaticDef(value) => { sb.to_id(InFile { value, file_id})?.into() },
-                    ast::FnDef(value) => { sb.to_id(InFile { value, file_id})?.into() },
+                    ast::ConstDef(value) => { sb.to_id(db, InFile { value, file_id})?.into() },
+                    ast::StaticDef(value) => { sb.to_id(db, InFile { value, file_id})?.into() },
+                    ast::FnDef(value) => { sb.to_id(db, InFile { value, file_id})?.into() },
                     _ => return None,
                 }
             };
             Some(res)
         })?;
-        let (_body, source_map) = sb.db.body_with_source_map(parent);
+        let (_body, source_map) = db.body_with_source_map(parent);
         let src = src.map(ast::Pat::from);
         let pat_id = source_map.node_pat(src.as_ref())?;
         Some(Local { parent: parent.into(), pat_id })
@@ -296,26 +272,26 @@ impl ToDef for ast::TypeParam {
     type Def = TypeParam;
 
     fn to_def<DB: HirDatabase>(
-        sb: &mut SourceBinder<'_, DB>,
+        db: &DB,
+        sb: &mut SourceBinder,
         src: InFile<ast::TypeParam>,
     ) -> Option<TypeParam> {
-        let mut sb = SourceBinder::new(sb.db);
         let file_id = src.file_id;
         let parent: GenericDefId = src.value.syntax().ancestors().find_map(|it| {
             let res = match_ast! {
                 match it {
-                    ast::FnDef(value) => { sb.to_id(InFile { value, file_id})?.into() },
-                    ast::StructDef(value) => { sb.to_id(InFile { value, file_id})?.into() },
-                    ast::EnumDef(value) => { sb.to_id(InFile { value, file_id})?.into() },
-                    ast::TraitDef(value) => { sb.to_id(InFile { value, file_id})?.into() },
-                    ast::TypeAliasDef(value) => { sb.to_id(InFile { value, file_id})?.into() },
-                    ast::ImplBlock(value) => { sb.to_id(InFile { value, file_id})?.into() },
+                    ast::FnDef(value) => { sb.to_id(db, InFile { value, file_id})?.into() },
+                    ast::StructDef(value) => { sb.to_id(db, InFile { value, file_id})?.into() },
+                    ast::EnumDef(value) => { sb.to_id(db, InFile { value, file_id})?.into() },
+                    ast::TraitDef(value) => { sb.to_id(db, InFile { value, file_id})?.into() },
+                    ast::TypeAliasDef(value) => { sb.to_id(db, InFile { value, file_id})?.into() },
+                    ast::ImplBlock(value) => { sb.to_id(db, InFile { value, file_id})?.into() },
                     _ => return None,
                 }
             };
             Some(res)
         })?;
-        let &id = sb.child_by_source(parent.into())[keys::TYPE_PARAM].get(&src)?;
+        let &id = sb.child_by_source(db, parent.into())[keys::TYPE_PARAM].get(&src)?;
         Some(TypeParam { id })
     }
 }
@@ -324,7 +300,8 @@ impl ToId for ast::Module {
     type ID = ModuleId;
 
     fn to_id<DB: HirDatabase>(
-        sb: &mut SourceBinder<'_, DB>,
+        db: &DB,
+        sb: &mut SourceBinder,
         src: InFile<ast::Module>,
     ) -> Option<ModuleId> {
         {
@@ -333,7 +310,7 @@ impl ToId for ast::Module {
                 .as_ref()
                 .map(|it| it.syntax())
                 .cloned()
-                .ancestors_with_macros(sb.db)
+                .ancestors_with_macros(db)
                 .skip(1)
                 .find_map(|it| {
                     let m = ast::Module::cast(it.value.clone())?;
@@ -341,15 +318,15 @@ impl ToId for ast::Module {
                 });
 
             let parent_module = match parent_declaration {
-                Some(parent_declaration) => sb.to_id(parent_declaration)?,
+                Some(parent_declaration) => sb.to_id(db, parent_declaration)?,
                 None => {
-                    let file_id = src.file_id.original_file(sb.db);
-                    sb.to_module_def(file_id)?.id
+                    let file_id = src.file_id.original_file(db);
+                    sb.to_module_def(db, file_id)?.id
                 }
             };
 
             let child_name = src.value.name()?.as_name();
-            let def_map = sb.db.crate_def_map(parent_module.krate);
+            let def_map = db.crate_def_map(parent_module.krate);
             let child_id = *def_map[parent_module.local_id].children.get(&child_name)?;
             Some(ModuleId { krate: parent_module.krate, local_id: child_id })
         }