move raw_items to hir_def

Cargo.lock

@@ -1019,11 +1019,18 @@ name = "ra_hir_def"
 version = "0.1.0"
 dependencies = [
  "log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
+ "once_cell 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "ra_arena 0.1.0",
+ "ra_cfg 0.1.0",
  "ra_db 0.1.0",
  "ra_hir_expand 0.1.0",
+ "ra_mbe 0.1.0",
  "ra_prof 0.1.0",
  "ra_syntax 0.1.0",
+ "ra_tt 0.1.0",
+ "relative-path 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rustc-hash 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "test_utils 0.1.0",
 ]
 
 [[package]]

crates/ra_hir/src/attr.rs

@@ -1,90 +1 @@
-//! A higher level attributes based on TokenTree, with also some shortcuts.
+pub use hir_def::attr::*;
-
-use std::sync::Arc;
-
-use mbe::ast_to_token_tree;
-use ra_cfg::CfgOptions;
-use ra_syntax::{
-    ast::{self, AstNode, AttrsOwner},
-    SmolStr,
-};
-use tt::Subtree;
-
-use crate::{db::AstDatabase, path::Path, HirFileId, Source};
-
-#[derive(Debug, Clone, PartialEq, Eq)]
-pub(crate) struct Attr {
-    pub(crate) path: Path,
-    pub(crate) input: Option<AttrInput>,
-}
-
-#[derive(Debug, Clone, PartialEq, Eq)]
-pub enum AttrInput {
-    Literal(SmolStr),
-    TokenTree(Subtree),
-}
-
-impl Attr {
-    pub(crate) fn from_src(
-        Source { file_id, ast }: Source<ast::Attr>,
-        db: &impl AstDatabase,
-    ) -> Option<Attr> {
-        let path = Path::from_src(Source { file_id, ast: ast.path()? }, db)?;
-        let input = match ast.input() {
-            None => None,
-            Some(ast::AttrInput::Literal(lit)) => {
-                // FIXME: escape? raw string?
-                let value = lit.syntax().first_token()?.text().trim_matches('"').into();
-                Some(AttrInput::Literal(value))
-            }
-            Some(ast::AttrInput::TokenTree(tt)) => {
-                Some(AttrInput::TokenTree(ast_to_token_tree(&tt)?.0))
-            }
-        };
-
-        Some(Attr { path, input })
-    }
-
-    pub(crate) fn from_attrs_owner(
-        file_id: HirFileId,
-        owner: &dyn AttrsOwner,
-        db: &impl AstDatabase,
-    ) -> Option<Arc<[Attr]>> {
-        let mut attrs = owner.attrs().peekable();
-        if attrs.peek().is_none() {
-            // Avoid heap allocation
-            return None;
-        }
-        Some(attrs.flat_map(|ast| Attr::from_src(Source { file_id, ast }, db)).collect())
-    }
-
-    pub(crate) fn is_simple_atom(&self, name: &str) -> bool {
-        // FIXME: Avoid cloning
-        self.path.as_ident().map_or(false, |s| s.to_string() == name)
-    }
-
-    // FIXME: handle cfg_attr :-)
-    pub(crate) fn as_cfg(&self) -> Option<&Subtree> {
-        if !self.is_simple_atom("cfg") {
-            return None;
-        }
-        match &self.input {
-            Some(AttrInput::TokenTree(subtree)) => Some(subtree),
-            _ => None,
-        }
-    }
-
-    pub(crate) fn as_path(&self) -> Option<&SmolStr> {
-        if !self.is_simple_atom("path") {
-            return None;
-        }
-        match &self.input {
-            Some(AttrInput::Literal(it)) => Some(it),
-            _ => None,
-        }
-    }
-
-    pub(crate) fn is_cfg_enabled(&self, cfg_options: &CfgOptions) -> Option<bool> {
-        cfg_options.is_cfg_enabled(self.as_cfg()?)
-    }
-}

crates/ra_hir/src/code_model.rs

@@ -6,7 +6,7 @@ pub(crate) mod docs;
 use std::sync::Arc;
 
 use hir_def::{CrateModuleId, ModuleId};
-use ra_db::{CrateId, Edition, FileId};
+use ra_db::{CrateId, Edition};
 use ra_syntax::ast::{self, NameOwner, TypeAscriptionOwner};
 
 use crate::{
@@ -33,7 +33,7 @@ use crate::{
     },
     type_ref::Mutability,
     type_ref::TypeRef,
-    AsName, AstId, Either, HasSource, Name, Ty,
+    AsName, Either, HasSource, Name, Ty,
 };
 
 /// hir::Crate describes a single crate. It's the main interface with which
@@ -147,31 +147,7 @@ impl_froms!(
     BuiltinType
 );
 
-pub enum ModuleSource {
+pub use hir_def::ModuleSource;
-    SourceFile(ast::SourceFile),
-    Module(ast::Module),
-}
-
-impl ModuleSource {
-    pub(crate) fn new(
-        db: &(impl DefDatabase + AstDatabase),
-        file_id: Option<FileId>,
-        decl_id: Option<AstId<ast::Module>>,
-    ) -> ModuleSource {
-        match (file_id, decl_id) {
-            (Some(file_id), _) => {
-                let source_file = db.parse(file_id).tree();
-                ModuleSource::SourceFile(source_file)
-            }
-            (None, Some(item_id)) => {
-                let module = item_id.to_node(db);
-                assert!(module.item_list().is_some(), "expected inline module");
-                ModuleSource::Module(module)
-            }
-            (None, None) => panic!(),
-        }
-    }
-}
 
 impl Module {
     pub(crate) fn new(krate: Crate, crate_module_id: CrateModuleId) -> Module {

crates/ra_hir/src/db.rs

@@ -12,15 +12,15 @@ use crate::{
     ids,
     impl_block::{ImplBlock, ImplSourceMap, ModuleImplBlocks},
     lang_item::{LangItemTarget, LangItems},
-    nameres::{CrateDefMap, ImportSourceMap, Namespace, RawItems},
+    nameres::{CrateDefMap, Namespace},
     traits::TraitData,
     ty::{
         method_resolution::CrateImplBlocks, traits::Impl, CallableDef, FnSig, GenericPredicate,
         InferenceResult, Substs, Ty, TypableDef, TypeCtor,
     },
     type_alias::TypeAliasData,
-    Const, ConstData, Crate, DefWithBody, Enum, ExprScopes, FnData, Function, HirFileId, Module,
+    Const, ConstData, Crate, DefWithBody, Enum, ExprScopes, FnData, Function, Module, Static,
-    Static, Struct, StructField, Trait, TypeAlias,
+    Struct, StructField, Trait, TypeAlias,
 };
 
 pub use hir_def::db::{InternDatabase, InternDatabaseStorage};
@@ -32,7 +32,7 @@ pub use hir_expand::db::{
 // This database uses `AstDatabase` internally,
 #[salsa::query_group(DefDatabaseStorage)]
 #[salsa::requires(AstDatabase)]
-pub trait DefDatabase: InternDatabase + HirDebugDatabase + AstDatabase {
+pub trait DefDatabase: HirDebugDatabase + hir_def::db::DefDatabase2 {
     #[salsa::invoke(crate::adt::StructData::struct_data_query)]
     fn struct_data(&self, s: Struct) -> Arc<StructData>;
 
@@ -45,15 +45,6 @@ pub trait DefDatabase: InternDatabase + HirDebugDatabase + AstDatabase {
     #[salsa::invoke(crate::traits::TraitItemsIndex::trait_items_index)]
     fn trait_items_index(&self, module: Module) -> crate::traits::TraitItemsIndex;
 
-    #[salsa::invoke(RawItems::raw_items_with_source_map_query)]
-    fn raw_items_with_source_map(
-        &self,
-        file_id: HirFileId,
-    ) -> (Arc<RawItems>, Arc<ImportSourceMap>);
-
-    #[salsa::invoke(RawItems::raw_items_query)]
-    fn raw_items(&self, file_id: HirFileId) -> Arc<RawItems>;
-
     #[salsa::invoke(CrateDefMap::crate_def_map_query)]
     fn crate_def_map(&self, krate: Crate) -> Arc<CrateDefMap>;
 

crates/ra_hir/src/either.rs

@@ -1,54 +1 @@
-//! FIXME: write short doc here
+pub use hir_def::either::*;
-
-#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
-pub enum Either<A, B> {
-    A(A),
-    B(B),
-}
-
-impl<A, B> Either<A, B> {
-    pub fn either<R, F1, F2>(self, f1: F1, f2: F2) -> R
-    where
-        F1: FnOnce(A) -> R,
-        F2: FnOnce(B) -> R,
-    {
-        match self {
-            Either::A(a) => f1(a),
-            Either::B(b) => f2(b),
-        }
-    }
-    pub fn map<U, V, F1, F2>(self, f1: F1, f2: F2) -> Either<U, V>
-    where
-        F1: FnOnce(A) -> U,
-        F2: FnOnce(B) -> V,
-    {
-        match self {
-            Either::A(a) => Either::A(f1(a)),
-            Either::B(b) => Either::B(f2(b)),
-        }
-    }
-    pub fn map_a<U, F>(self, f: F) -> Either<U, B>
-    where
-        F: FnOnce(A) -> U,
-    {
-        self.map(f, |it| it)
-    }
-    pub fn a(self) -> Option<A> {
-        match self {
-            Either::A(it) => Some(it),
-            Either::B(_) => None,
-        }
-    }
-    pub fn b(self) -> Option<B> {
-        match self {
-            Either::A(_) => None,
-            Either::B(it) => Some(it),
-        }
-    }
-    pub fn as_ref(&self) -> Either<&A, &B> {
-        match self {
-            Either::A(it) => Either::A(it),
-            Either::B(it) => Either::B(it),
-        }
-    }
-}

crates/ra_hir/src/from_source.rs

@@ -1,11 +1,6 @@
 //! FIXME: write short doc here
 
-use ra_db::{FileId, FilePosition};
+use ra_syntax::ast::{self, AstNode, NameOwner};
-use ra_syntax::{
-    algo::find_node_at_offset,
-    ast::{self, AstNode, NameOwner},
-    SyntaxNode,
-};
 
 use crate::{
     db::{AstDatabase, DefDatabase, HirDatabase},
@@ -129,41 +124,6 @@ impl FromSource for StructField {
     }
 }
 
-// FIXME: simplify it
-impl ModuleSource {
-    pub fn from_position(
-        db: &(impl DefDatabase + AstDatabase),
-        position: FilePosition,
-    ) -> ModuleSource {
-        let parse = db.parse(position.file_id);
-        match &find_node_at_offset::<ast::Module>(parse.tree().syntax(), position.offset) {
-            Some(m) if !m.has_semi() => ModuleSource::Module(m.clone()),
-            _ => {
-                let source_file = parse.tree();
-                ModuleSource::SourceFile(source_file)
-            }
-        }
-    }
-
-    pub fn from_child_node(
-        db: &(impl DefDatabase + AstDatabase),
-        file_id: FileId,
-        child: &SyntaxNode,
-    ) -> ModuleSource {
-        if let Some(m) = child.ancestors().filter_map(ast::Module::cast).find(|it| !it.has_semi()) {
-            ModuleSource::Module(m)
-        } else {
-            let source_file = db.parse(file_id).tree();
-            ModuleSource::SourceFile(source_file)
-        }
-    }
-
-    pub fn from_file_id(db: &(impl DefDatabase + AstDatabase), file_id: FileId) -> ModuleSource {
-        let source_file = db.parse(file_id).tree();
-        ModuleSource::SourceFile(source_file)
-    }
-}
-
 impl Module {
     pub fn from_declaration(db: &impl HirDatabase, src: Source<ast::Module>) -> Option<Self> {
         let src_parent = Source {

crates/ra_hir/src/lib.rs

@@ -59,10 +59,7 @@ pub mod from_source;
 #[cfg(test)]
 mod marks;
 
-use hir_expand::{
+use hir_expand::AstId;
-    ast_id_map::{AstIdMap, FileAstId},
-    AstId,
-};
 
 use crate::{ids::MacroFileKind, name::AsName, resolve::Resolver};
 

crates/ra_hir/src/marks.rs

@@ -2,6 +2,7 @@
 
 test_utils::marks!(
     bogus_paths
+    // FIXME: restore this mark once hir is split
     name_res_works_for_broken_modules
     can_import_enum_variant
     type_var_cycles_resolve_completely

crates/ra_hir/src/mock.rs

@@ -17,6 +17,7 @@ use crate::{db, debug::HirDebugHelper, diagnostics::DiagnosticSink};
 pub const WORKSPACE: SourceRootId = SourceRootId(0);
 
 #[salsa::database(
+    hir_def::db::DefDatabase2Storage,
     ra_db::SourceDatabaseExtStorage,
     ra_db::SourceDatabaseStorage,
     db::InternDatabaseStorage,

crates/ra_hir/src/name.rs

@@ -1,142 +1 @@
-//! FIXME: write short doc here
+pub use hir_def::name::*;
-
-use std::fmt;
-
-use ra_syntax::{ast, SmolStr};
-
-/// `Name` is a wrapper around string, which is used in hir for both references
-/// and declarations. In theory, names should also carry hygiene info, but we are
-/// not there yet!
-#[derive(Debug, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
-pub struct Name(Repr);
-
-#[derive(Debug, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
-enum Repr {
-    Text(SmolStr),
-    TupleField(usize),
-}
-
-impl fmt::Display for Name {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        match &self.0 {
-            Repr::Text(text) => fmt::Display::fmt(&text, f),
-            Repr::TupleField(idx) => fmt::Display::fmt(&idx, f),
-        }
-    }
-}
-
-impl Name {
-    /// Note: this is private to make creating name from random string hard.
-    /// Hopefully, this should allow us to integrate hygiene cleaner in the
-    /// future, and to switch to interned representation of names.
-    const fn new_text(text: SmolStr) -> Name {
-        Name(Repr::Text(text))
-    }
-
-    pub(crate) fn new_tuple_field(idx: usize) -> Name {
-        Name(Repr::TupleField(idx))
-    }
-
-    /// Shortcut to create inline plain text name
-    const fn new_inline_ascii(len: usize, text: &[u8]) -> Name {
-        Name::new_text(SmolStr::new_inline_from_ascii(len, text))
-    }
-
-    /// Resolve a name from the text of token.
-    fn resolve(raw_text: &SmolStr) -> Name {
-        let raw_start = "r#";
-        if raw_text.as_str().starts_with(raw_start) {
-            Name::new_text(SmolStr::new(&raw_text[raw_start.len()..]))
-        } else {
-            Name::new_text(raw_text.clone())
-        }
-    }
-
-    pub(crate) fn missing() -> Name {
-        Name::new_text("[missing name]".into())
-    }
-
-    pub(crate) fn as_tuple_index(&self) -> Option<usize> {
-        match self.0 {
-            Repr::TupleField(idx) => Some(idx),
-            _ => None,
-        }
-    }
-}
-
-pub(crate) trait AsName {
-    fn as_name(&self) -> Name;
-}
-
-impl AsName for ast::NameRef {
-    fn as_name(&self) -> Name {
-        match self.as_tuple_field() {
-            Some(idx) => Name::new_tuple_field(idx),
-            None => Name::resolve(self.text()),
-        }
-    }
-}
-
-impl AsName for ast::Name {
-    fn as_name(&self) -> Name {
-        Name::resolve(self.text())
-    }
-}
-
-impl AsName for ast::FieldKind {
-    fn as_name(&self) -> Name {
-        match self {
-            ast::FieldKind::Name(nr) => nr.as_name(),
-            ast::FieldKind::Index(idx) => Name::new_tuple_field(idx.text().parse().unwrap()),
-        }
-    }
-}
-
-impl AsName for ra_db::Dependency {
-    fn as_name(&self) -> Name {
-        Name::new_text(self.name.clone())
-    }
-}
-
-// Primitives
-pub(crate) const ISIZE: Name = Name::new_inline_ascii(5, b"isize");
-pub(crate) const I8: Name = Name::new_inline_ascii(2, b"i8");
-pub(crate) const I16: Name = Name::new_inline_ascii(3, b"i16");
-pub(crate) const I32: Name = Name::new_inline_ascii(3, b"i32");
-pub(crate) const I64: Name = Name::new_inline_ascii(3, b"i64");
-pub(crate) const I128: Name = Name::new_inline_ascii(4, b"i128");
-pub(crate) const USIZE: Name = Name::new_inline_ascii(5, b"usize");
-pub(crate) const U8: Name = Name::new_inline_ascii(2, b"u8");
-pub(crate) const U16: Name = Name::new_inline_ascii(3, b"u16");
-pub(crate) const U32: Name = Name::new_inline_ascii(3, b"u32");
-pub(crate) const U64: Name = Name::new_inline_ascii(3, b"u64");
-pub(crate) const U128: Name = Name::new_inline_ascii(4, b"u128");
-pub(crate) const F32: Name = Name::new_inline_ascii(3, b"f32");
-pub(crate) const F64: Name = Name::new_inline_ascii(3, b"f64");
-pub(crate) const BOOL: Name = Name::new_inline_ascii(4, b"bool");
-pub(crate) const CHAR: Name = Name::new_inline_ascii(4, b"char");
-pub(crate) const STR: Name = Name::new_inline_ascii(3, b"str");
-
-// Special names
-pub(crate) const SELF_PARAM: Name = Name::new_inline_ascii(4, b"self");
-pub(crate) const SELF_TYPE: Name = Name::new_inline_ascii(4, b"Self");
-pub(crate) const MACRO_RULES: Name = Name::new_inline_ascii(11, b"macro_rules");
-
-// Components of known path (value or mod name)
-pub(crate) const STD: Name = Name::new_inline_ascii(3, b"std");
-pub(crate) const ITER: Name = Name::new_inline_ascii(4, b"iter");
-pub(crate) const OPS: Name = Name::new_inline_ascii(3, b"ops");
-pub(crate) const FUTURE: Name = Name::new_inline_ascii(6, b"future");
-pub(crate) const RESULT: Name = Name::new_inline_ascii(6, b"result");
-pub(crate) const BOXED: Name = Name::new_inline_ascii(5, b"boxed");
-
-// Components of known path (type name)
-pub(crate) const INTO_ITERATOR_TYPE: Name = Name::new_inline_ascii(12, b"IntoIterator");
-pub(crate) const ITEM_TYPE: Name = Name::new_inline_ascii(4, b"Item");
-pub(crate) const TRY_TYPE: Name = Name::new_inline_ascii(3, b"Try");
-pub(crate) const OK_TYPE: Name = Name::new_inline_ascii(2, b"Ok");
-pub(crate) const FUTURE_TYPE: Name = Name::new_inline_ascii(6, b"Future");
-pub(crate) const RESULT_TYPE: Name = Name::new_inline_ascii(6, b"Result");
-pub(crate) const OUTPUT_TYPE: Name = Name::new_inline_ascii(6, b"Output");
-pub(crate) const TARGET_TYPE: Name = Name::new_inline_ascii(6, b"Target");
-pub(crate) const BOX_TYPE: Name = Name::new_inline_ascii(3, b"Box");

crates/ra_hir/src/nameres.rs

@@ -48,7 +48,6 @@
 //! on the result
 
 mod per_ns;
-mod raw;
 mod collector;
 mod mod_resolution;
 #[cfg(test)]
@@ -74,12 +73,9 @@ use crate::{
     Trait,
 };
 
-pub(crate) use self::raw::{ImportSourceMap, RawItems};
+pub use self::per_ns::{Namespace, PerNs};
 
-pub use self::{
+pub use hir_def::nameres::raw::ImportId;
-    per_ns::{Namespace, PerNs},
-    raw::ImportId,
-};
 
 /// Contains all top-level defs from a macro-expanded crate
 #[derive(Debug, PartialEq, Eq)]
@@ -328,7 +324,8 @@ impl CrateDefMap {
     ) -> ResolvePathResult {
         let mut segments = path.segments.iter().enumerate();
         let mut curr_per_ns: PerNs = match path.kind {
-            PathKind::DollarCrate(krate) => {
+            PathKind::DollarCrate(crate_id) => {
+                let krate = Crate { crate_id };
                 if krate == self.krate {
                     tested_by!(macro_dollar_crate_self);
                     PerNs::types(Module::new(self.krate, self.root).into())

crates/ra_hir/src/nameres/collector.rs

@@ -1,5 +1,6 @@
 //! FIXME: write short doc here
 
+use hir_def::nameres::raw;
 use ra_cfg::CfgOptions;
 use ra_db::FileId;
 use ra_syntax::{ast, SmolStr};
@@ -12,7 +13,7 @@ use crate::{
     ids::{AstItemDef, LocationCtx, MacroCallId, MacroCallLoc, MacroDefId, MacroFileKind},
     name::MACRO_RULES,
     nameres::{
-        diagnostics::DefDiagnostic, mod_resolution::ModDir, raw, Crate, CrateDefMap, CrateModuleId,
+        diagnostics::DefDiagnostic, mod_resolution::ModDir, Crate, CrateDefMap, CrateModuleId,
         ModuleData, ModuleDef, PerNs, ReachedFixedPoint, Resolution, ResolveMode,
     },
     Adt, AstId, Const, Enum, Function, HirFileId, MacroDef, Module, Name, Path, PathKind, Static,

crates/ra_hir/src/nameres/tests/mod_resolution.rs

@@ -2,7 +2,7 @@ use super::*;
 
 #[test]
 fn name_res_works_for_broken_modules() {
-    covers!(name_res_works_for_broken_modules);
+    // covers!(name_res_works_for_broken_modules);
     let map = def_map(
         "
         //- /lib.rs

crates/ra_hir/src/path.rs

@@ -1,422 +1 @@
-//! FIXME: write short doc here
+pub use hir_def::path::*;
-
-use std::{iter, sync::Arc};
-
-use ra_syntax::{
-    ast::{self, NameOwner, TypeAscriptionOwner},
-    AstNode,
-};
-
-use crate::{db::AstDatabase, name, type_ref::TypeRef, AsName, Crate, Name, Source};
-
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub struct Path {
-    pub kind: PathKind,
-    pub segments: Vec<PathSegment>,
-}
-
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub struct PathSegment {
-    pub name: Name,
-    pub args_and_bindings: Option<Arc<GenericArgs>>,
-}
-
-/// Generic arguments to a path segment (e.g. the `i32` in `Option<i32>`). This
-/// can (in the future) also include bindings of associated types, like in
-/// `Iterator<Item = Foo>`.
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub struct GenericArgs {
-    pub args: Vec<GenericArg>,
-    /// This specifies whether the args contain a Self type as the first
-    /// element. This is the case for path segments like `<T as Trait>`, where
-    /// `T` is actually a type parameter for the path `Trait` specifying the
-    /// Self type. Otherwise, when we have a path `Trait<X, Y>`, the Self type
-    /// is left out.
-    pub has_self_type: bool,
-    /// Associated type bindings like in `Iterator<Item = T>`.
-    pub bindings: Vec<(Name, TypeRef)>,
-}
-
-/// A single generic argument.
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub enum GenericArg {
-    Type(TypeRef),
-    // or lifetime...
-}
-
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub enum PathKind {
-    Plain,
-    Self_,
-    Super,
-    Crate,
-    // Absolute path
-    Abs,
-    // Type based path like `<T>::foo`
-    Type(Box<TypeRef>),
-    // `$crate` from macro expansion
-    DollarCrate(Crate),
-}
-
-impl Path {
-    /// Calls `cb` with all paths, represented by this use item.
-    pub fn expand_use_item(
-        item_src: Source<ast::UseItem>,
-        db: &impl AstDatabase,
-        mut cb: impl FnMut(Path, &ast::UseTree, bool, Option<Name>),
-    ) {
-        if let Some(tree) = item_src.ast.use_tree() {
-            expand_use_tree(
-                None,
-                tree,
-                &|| item_src.file_id.macro_crate(db).map(|crate_id| Crate { crate_id }),
-                &mut cb,
-            );
-        }
-    }
-
-    pub fn from_simple_segments(kind: PathKind, segments: impl IntoIterator<Item = Name>) -> Path {
-        Path {
-            kind,
-            segments: segments
-                .into_iter()
-                .map(|name| PathSegment { name, args_and_bindings: None })
-                .collect(),
-        }
-    }
-
-    /// Converts an `ast::Path` to `Path`. Works with use trees.
-    /// DEPRECATED: It does not handle `$crate` from macro call.
-    pub fn from_ast(path: ast::Path) -> Option<Path> {
-        Path::parse(path, &|| None)
-    }
-
-    /// Converts an `ast::Path` to `Path`. Works with use trees.
-    /// It correctly handles `$crate` based path from macro call.
-    pub fn from_src(source: Source<ast::Path>, db: &impl AstDatabase) -> Option<Path> {
-        let file_id = source.file_id;
-        Path::parse(source.ast, &|| file_id.macro_crate(db).map(|crate_id| Crate { crate_id }))
-    }
-
-    fn parse(mut path: ast::Path, macro_crate: &impl Fn() -> Option<Crate>) -> Option<Path> {
-        let mut kind = PathKind::Plain;
-        let mut segments = Vec::new();
-        loop {
-            let segment = path.segment()?;
-
-            if segment.has_colon_colon() {
-                kind = PathKind::Abs;
-            }
-
-            match segment.kind()? {
-                ast::PathSegmentKind::Name(name) => {
-                    if name.text() == "$crate" {
-                        if let Some(macro_crate) = macro_crate() {
-                            kind = PathKind::DollarCrate(macro_crate);
-                            break;
-                        }
-                    }
-
-                    let args = segment
-                        .type_arg_list()
-                        .and_then(GenericArgs::from_ast)
-                        .or_else(|| {
-                            GenericArgs::from_fn_like_path_ast(
-                                segment.param_list(),
-                                segment.ret_type(),
-                            )
-                        })
-                        .map(Arc::new);
-                    let segment = PathSegment { name: name.as_name(), args_and_bindings: args };
-                    segments.push(segment);
-                }
-                ast::PathSegmentKind::Type { type_ref, trait_ref } => {
-                    assert!(path.qualifier().is_none()); // this can only occur at the first segment
-
-                    let self_type = TypeRef::from_ast(type_ref?);
-
-                    match trait_ref {
-                        // <T>::foo
-                        None => {
-                            kind = PathKind::Type(Box::new(self_type));
-                        }
-                        // <T as Trait<A>>::Foo desugars to Trait<Self=T, A>::Foo
-                        Some(trait_ref) => {
-                            let path = Path::parse(trait_ref.path()?, macro_crate)?;
-                            kind = path.kind;
-                            let mut prefix_segments = path.segments;
-                            prefix_segments.reverse();
-                            segments.extend(prefix_segments);
-                            // Insert the type reference (T in the above example) as Self parameter for the trait
-                            let mut last_segment = segments.last_mut()?;
-                            if last_segment.args_and_bindings.is_none() {
-                                last_segment.args_and_bindings =
-                                    Some(Arc::new(GenericArgs::empty()));
-                            };
-                            let args = last_segment.args_and_bindings.as_mut().unwrap();
-                            let mut args_inner = Arc::make_mut(args);
-                            args_inner.has_self_type = true;
-                            args_inner.args.insert(0, GenericArg::Type(self_type));
-                        }
-                    }
-                }
-                ast::PathSegmentKind::CrateKw => {
-                    kind = PathKind::Crate;
-                    break;
-                }
-                ast::PathSegmentKind::SelfKw => {
-                    kind = PathKind::Self_;
-                    break;
-                }
-                ast::PathSegmentKind::SuperKw => {
-                    kind = PathKind::Super;
-                    break;
-                }
-            }
-            path = match qualifier(&path) {
-                Some(it) => it,
-                None => break,
-            };
-        }
-        segments.reverse();
-        return Some(Path { kind, segments });
-
-        fn qualifier(path: &ast::Path) -> Option<ast::Path> {
-            if let Some(q) = path.qualifier() {
-                return Some(q);
-            }
-            // FIXME: this bottom up traversal is not too precise.
-            // Should we handle do a top-down analysis, recording results?
-            let use_tree_list = path.syntax().ancestors().find_map(ast::UseTreeList::cast)?;
-            let use_tree = use_tree_list.parent_use_tree();
-            use_tree.path()
-        }
-    }
-
-    /// Converts an `ast::NameRef` into a single-identifier `Path`.
-    pub fn from_name_ref(name_ref: &ast::NameRef) -> Path {
-        name_ref.as_name().into()
-    }
-
-    /// `true` is this path is a single identifier, like `foo`
-    pub fn is_ident(&self) -> bool {
-        self.kind == PathKind::Plain && self.segments.len() == 1
-    }
-
-    /// `true` if this path is just a standalone `self`
-    pub fn is_self(&self) -> bool {
-        self.kind == PathKind::Self_ && self.segments.is_empty()
-    }
-
-    /// If this path is a single identifier, like `foo`, return its name.
-    pub fn as_ident(&self) -> Option<&Name> {
-        if self.kind != PathKind::Plain || self.segments.len() > 1 {
-            return None;
-        }
-        self.segments.first().map(|s| &s.name)
-    }
-
-    pub fn expand_macro_expr(&self) -> Option<Name> {
-        self.as_ident().and_then(|name| Some(name.clone()))
-    }
-
-    pub fn is_type_relative(&self) -> bool {
-        match self.kind {
-            PathKind::Type(_) => true,
-            _ => false,
-        }
-    }
-}
-
-impl GenericArgs {
-    pub(crate) fn from_ast(node: ast::TypeArgList) -> Option<GenericArgs> {
-        let mut args = Vec::new();
-        for type_arg in node.type_args() {
-            let type_ref = TypeRef::from_ast_opt(type_arg.type_ref());
-            args.push(GenericArg::Type(type_ref));
-        }
-        // lifetimes ignored for now
-        let mut bindings = Vec::new();
-        for assoc_type_arg in node.assoc_type_args() {
-            if let Some(name_ref) = assoc_type_arg.name_ref() {
-                let name = name_ref.as_name();
-                let type_ref = TypeRef::from_ast_opt(assoc_type_arg.type_ref());
-                bindings.push((name, type_ref));
-            }
-        }
-        if args.is_empty() && bindings.is_empty() {
-            None
-        } else {
-            Some(GenericArgs { args, has_self_type: false, bindings })
-        }
-    }
-
-    /// Collect `GenericArgs` from the parts of a fn-like path, i.e. `Fn(X, Y)
-    /// -> Z` (which desugars to `Fn<(X, Y), Output=Z>`).
-    pub(crate) fn from_fn_like_path_ast(
-        params: Option<ast::ParamList>,
-        ret_type: Option<ast::RetType>,
-    ) -> Option<GenericArgs> {
-        let mut args = Vec::new();
-        let mut bindings = Vec::new();
-        if let Some(params) = params {
-            let mut param_types = Vec::new();
-            for param in params.params() {
-                let type_ref = TypeRef::from_ast_opt(param.ascribed_type());
-                param_types.push(type_ref);
-            }
-            let arg = GenericArg::Type(TypeRef::Tuple(param_types));
-            args.push(arg);
-        }
-        if let Some(ret_type) = ret_type {
-            let type_ref = TypeRef::from_ast_opt(ret_type.type_ref());
-            bindings.push((name::OUTPUT_TYPE, type_ref))
-        }
-        if args.is_empty() && bindings.is_empty() {
-            None
-        } else {
-            Some(GenericArgs { args, has_self_type: false, bindings })
-        }
-    }
-
-    pub(crate) fn empty() -> GenericArgs {
-        GenericArgs { args: Vec::new(), has_self_type: false, bindings: Vec::new() }
-    }
-}
-
-impl From<Name> for Path {
-    fn from(name: Name) -> Path {
-        Path::from_simple_segments(PathKind::Plain, iter::once(name))
-    }
-}
-
-fn expand_use_tree(
-    prefix: Option<Path>,
-    tree: ast::UseTree,
-    macro_crate: &impl Fn() -> Option<Crate>,
-    cb: &mut impl FnMut(Path, &ast::UseTree, bool, Option<Name>),
-) {
-    if let Some(use_tree_list) = tree.use_tree_list() {
-        let prefix = match tree.path() {
-            // E.g. use something::{{{inner}}};
-            None => prefix,
-            // E.g. `use something::{inner}` (prefix is `None`, path is `something`)
-            // or `use something::{path::{inner::{innerer}}}` (prefix is `something::path`, path is `inner`)
-            Some(path) => match convert_path(prefix, path, macro_crate) {
-                Some(it) => Some(it),
-                None => return, // FIXME: report errors somewhere
-            },
-        };
-        for child_tree in use_tree_list.use_trees() {
-            expand_use_tree(prefix.clone(), child_tree, macro_crate, cb);
-        }
-    } else {
-        let alias = tree.alias().and_then(|a| a.name()).map(|a| a.as_name());
-        if let Some(ast_path) = tree.path() {
-            // Handle self in a path.
-            // E.g. `use something::{self, <...>}`
-            if ast_path.qualifier().is_none() {
-                if let Some(segment) = ast_path.segment() {
-                    if segment.kind() == Some(ast::PathSegmentKind::SelfKw) {
-                        if let Some(prefix) = prefix {
-                            cb(prefix, &tree, false, alias);
-                            return;
-                        }
-                    }
-                }
-            }
-            if let Some(path) = convert_path(prefix, ast_path, macro_crate) {
-                let is_glob = tree.has_star();
-                cb(path, &tree, is_glob, alias)
-            }
-            // FIXME: report errors somewhere
-            // We get here if we do
-        }
-    }
-}
-
-fn convert_path(
-    prefix: Option<Path>,
-    path: ast::Path,
-    macro_crate: &impl Fn() -> Option<Crate>,
-) -> Option<Path> {
-    let prefix = if let Some(qual) = path.qualifier() {
-        Some(convert_path(prefix, qual, macro_crate)?)
-    } else {
-        prefix
-    };
-
-    let segment = path.segment()?;
-    let res = match segment.kind()? {
-        ast::PathSegmentKind::Name(name) => {
-            if name.text() == "$crate" {
-                if let Some(krate) = macro_crate() {
-                    return Some(Path::from_simple_segments(
-                        PathKind::DollarCrate(krate),
-                        iter::empty(),
-                    ));
-                }
-            }
-
-            // no type args in use
-            let mut res = prefix
-                .unwrap_or_else(|| Path { kind: PathKind::Plain, segments: Vec::with_capacity(1) });
-            res.segments.push(PathSegment {
-                name: name.as_name(),
-                args_and_bindings: None, // no type args in use
-            });
-            res
-        }
-        ast::PathSegmentKind::CrateKw => {
-            if prefix.is_some() {
-                return None;
-            }
-            Path::from_simple_segments(PathKind::Crate, iter::empty())
-        }
-        ast::PathSegmentKind::SelfKw => {
-            if prefix.is_some() {
-                return None;
-            }
-            Path::from_simple_segments(PathKind::Self_, iter::empty())
-        }
-        ast::PathSegmentKind::SuperKw => {
-            if prefix.is_some() {
-                return None;
-            }
-            Path::from_simple_segments(PathKind::Super, iter::empty())
-        }
-        ast::PathSegmentKind::Type { .. } => {
-            // not allowed in imports
-            return None;
-        }
-    };
-    Some(res)
-}
-
-pub mod known {
-    use super::{Path, PathKind};
-    use crate::name;
-
-    pub fn std_iter_into_iterator() -> Path {
-        Path::from_simple_segments(
-            PathKind::Abs,
-            vec![name::STD, name::ITER, name::INTO_ITERATOR_TYPE],
-        )
-    }
-
-    pub fn std_ops_try() -> Path {
-        Path::from_simple_segments(PathKind::Abs, vec![name::STD, name::OPS, name::TRY_TYPE])
-    }
-
-    pub fn std_result_result() -> Path {
-        Path::from_simple_segments(PathKind::Abs, vec![name::STD, name::RESULT, name::RESULT_TYPE])
-    }
-
-    pub fn std_future_future() -> Path {
-        Path::from_simple_segments(PathKind::Abs, vec![name::STD, name::FUTURE, name::FUTURE_TYPE])
-    }
-
-    pub fn std_boxed_box() -> Path {
-        Path::from_simple_segments(PathKind::Abs, vec![name::STD, name::BOXED, name::BOX_TYPE])
-    }
-}

crates/ra_hir/src/type_ref.rs

@@ -1,162 +1 @@
-//! HIR for references to types. Paths in these are not yet resolved. They can
+pub use hir_def::type_ref::*;
-//! be directly created from an ast::TypeRef, without further queries.
-
-use ra_syntax::ast::{self, TypeAscriptionOwner, TypeBoundsOwner};
-
-use crate::Path;
-
-#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
-pub enum Mutability {
-    Shared,
-    Mut,
-}
-
-impl Mutability {
-    pub fn from_mutable(mutable: bool) -> Mutability {
-        if mutable {
-            Mutability::Mut
-        } else {
-            Mutability::Shared
-        }
-    }
-
-    pub fn as_keyword_for_ref(self) -> &'static str {
-        match self {
-            Mutability::Shared => "",
-            Mutability::Mut => "mut ",
-        }
-    }
-
-    pub fn as_keyword_for_ptr(self) -> &'static str {
-        match self {
-            Mutability::Shared => "const ",
-            Mutability::Mut => "mut ",
-        }
-    }
-}
-
-/// Compare ty::Ty
-#[derive(Clone, PartialEq, Eq, Hash, Debug)]
-pub enum TypeRef {
-    Never,
-    Placeholder,
-    Tuple(Vec<TypeRef>),
-    Path(Path),
-    RawPtr(Box<TypeRef>, Mutability),
-    Reference(Box<TypeRef>, Mutability),
-    Array(Box<TypeRef> /*, Expr*/),
-    Slice(Box<TypeRef>),
-    /// A fn pointer. Last element of the vector is the return type.
-    Fn(Vec<TypeRef>),
-    // For
-    ImplTrait(Vec<TypeBound>),
-    DynTrait(Vec<TypeBound>),
-    Error,
-}
-
-#[derive(Clone, PartialEq, Eq, Hash, Debug)]
-pub enum TypeBound {
-    Path(Path),
-    // also for<> bounds
-    // also Lifetimes
-    Error,
-}
-
-impl TypeRef {
-    /// Converts an `ast::TypeRef` to a `hir::TypeRef`.
-    pub(crate) fn from_ast(node: ast::TypeRef) -> Self {
-        match node {
-            ast::TypeRef::ParenType(inner) => TypeRef::from_ast_opt(inner.type_ref()),
-            ast::TypeRef::TupleType(inner) => {
-                TypeRef::Tuple(inner.fields().map(TypeRef::from_ast).collect())
-            }
-            ast::TypeRef::NeverType(..) => TypeRef::Never,
-            ast::TypeRef::PathType(inner) => {
-                // FIXME: Use `Path::from_src`
-                inner.path().and_then(Path::from_ast).map(TypeRef::Path).unwrap_or(TypeRef::Error)
-            }
-            ast::TypeRef::PointerType(inner) => {
-                let inner_ty = TypeRef::from_ast_opt(inner.type_ref());
-                let mutability = Mutability::from_mutable(inner.is_mut());
-                TypeRef::RawPtr(Box::new(inner_ty), mutability)
-            }
-            ast::TypeRef::ArrayType(inner) => {
-                TypeRef::Array(Box::new(TypeRef::from_ast_opt(inner.type_ref())))
-            }
-            ast::TypeRef::SliceType(inner) => {
-                TypeRef::Slice(Box::new(TypeRef::from_ast_opt(inner.type_ref())))
-            }
-            ast::TypeRef::ReferenceType(inner) => {
-                let inner_ty = TypeRef::from_ast_opt(inner.type_ref());
-                let mutability = Mutability::from_mutable(inner.is_mut());
-                TypeRef::Reference(Box::new(inner_ty), mutability)
-            }
-            ast::TypeRef::PlaceholderType(_inner) => TypeRef::Placeholder,
-            ast::TypeRef::FnPointerType(inner) => {
-                let ret_ty = TypeRef::from_ast_opt(inner.ret_type().and_then(|rt| rt.type_ref()));
-                let mut params = if let Some(pl) = inner.param_list() {
-                    pl.params().map(|p| p.ascribed_type()).map(TypeRef::from_ast_opt).collect()
-                } else {
-                    Vec::new()
-                };
-                params.push(ret_ty);
-                TypeRef::Fn(params)
-            }
-            // for types are close enough for our purposes to the inner type for now...
-            ast::TypeRef::ForType(inner) => TypeRef::from_ast_opt(inner.type_ref()),
-            ast::TypeRef::ImplTraitType(inner) => {
-                TypeRef::ImplTrait(type_bounds_from_ast(inner.type_bound_list()))
-            }
-            ast::TypeRef::DynTraitType(inner) => {
-                TypeRef::DynTrait(type_bounds_from_ast(inner.type_bound_list()))
-            }
-        }
-    }
-
-    pub(crate) fn from_ast_opt(node: Option<ast::TypeRef>) -> Self {
-        if let Some(node) = node {
-            TypeRef::from_ast(node)
-        } else {
-            TypeRef::Error
-        }
-    }
-
-    pub fn unit() -> TypeRef {
-        TypeRef::Tuple(Vec::new())
-    }
-}
-
-pub(crate) fn type_bounds_from_ast(type_bounds_opt: Option<ast::TypeBoundList>) -> Vec<TypeBound> {
-    if let Some(type_bounds) = type_bounds_opt {
-        type_bounds.bounds().map(TypeBound::from_ast).collect()
-    } else {
-        vec![]
-    }
-}
-
-impl TypeBound {
-    pub(crate) fn from_ast(node: ast::TypeBound) -> Self {
-        match node.kind() {
-            ast::TypeBoundKind::PathType(path_type) => {
-                let path = match path_type.path() {
-                    Some(p) => p,
-                    None => return TypeBound::Error,
-                };
-                // FIXME: Use `Path::from_src`
-                let path = match Path::from_ast(path) {
-                    Some(p) => p,
-                    None => return TypeBound::Error,
-                };
-                TypeBound::Path(path)
-            }
-            ast::TypeBoundKind::ForType(_) | ast::TypeBoundKind::Lifetime(_) => TypeBound::Error,
-        }
-    }
-
-    pub fn as_path(&self) -> Option<&Path> {
-        match self {
-            TypeBound::Path(p) => Some(p),
-            _ => None,
-        }
-    }
-}

crates/ra_hir_def/Cargo.toml

@@ -6,9 +6,16 @@ authors = ["rust-analyzer developers"]
 
 [dependencies]
 log = "0.4.5"
+once_cell = "1.0.1"
+relative-path = "1.0.0"
+rustc-hash = "1.0"
 
 ra_arena = { path = "../ra_arena" }
 ra_db = { path = "../ra_db" }
 ra_syntax = { path = "../ra_syntax" }
 ra_prof = { path = "../ra_prof" }
 hir_expand = { path = "../ra_hir_expand", package = "ra_hir_expand" }
+test_utils = { path = "../test_utils" }
+mbe = { path = "../ra_mbe", package = "ra_mbe" }
+ra_cfg = { path = "../ra_cfg" }
+tt = { path = "../ra_tt", package = "ra_tt" }

crates/ra_hir_def/src/attr.rs

@@ -0,0 +1,91 @@
+//! A higher level attributes based on TokenTree, with also some shortcuts.
+
+use std::sync::Arc;
+
+use hir_expand::db::AstDatabase;
+use mbe::ast_to_token_tree;
+use ra_cfg::CfgOptions;
+use ra_syntax::{
+    ast::{self, AstNode, AttrsOwner},
+    SmolStr,
+};
+use tt::Subtree;
+
+use crate::{path::Path, HirFileId, Source};
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct Attr {
+    pub(crate) path: Path,
+    pub(crate) input: Option<AttrInput>,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum AttrInput {
+    Literal(SmolStr),
+    TokenTree(Subtree),
+}
+
+impl Attr {
+    pub(crate) fn from_src(
+        Source { file_id, ast }: Source<ast::Attr>,
+        db: &impl AstDatabase,
+    ) -> Option<Attr> {
+        let path = Path::from_src(Source { file_id, ast: ast.path()? }, db)?;
+        let input = match ast.input() {
+            None => None,
+            Some(ast::AttrInput::Literal(lit)) => {
+                // FIXME: escape? raw string?
+                let value = lit.syntax().first_token()?.text().trim_matches('"').into();
+                Some(AttrInput::Literal(value))
+            }
+            Some(ast::AttrInput::TokenTree(tt)) => {
+                Some(AttrInput::TokenTree(ast_to_token_tree(&tt)?.0))
+            }
+        };
+
+        Some(Attr { path, input })
+    }
+
+    pub fn from_attrs_owner(
+        file_id: HirFileId,
+        owner: &dyn AttrsOwner,
+        db: &impl AstDatabase,
+    ) -> Option<Arc<[Attr]>> {
+        let mut attrs = owner.attrs().peekable();
+        if attrs.peek().is_none() {
+            // Avoid heap allocation
+            return None;
+        }
+        Some(attrs.flat_map(|ast| Attr::from_src(Source { file_id, ast }, db)).collect())
+    }
+
+    pub fn is_simple_atom(&self, name: &str) -> bool {
+        // FIXME: Avoid cloning
+        self.path.as_ident().map_or(false, |s| s.to_string() == name)
+    }
+
+    // FIXME: handle cfg_attr :-)
+    pub fn as_cfg(&self) -> Option<&Subtree> {
+        if !self.is_simple_atom("cfg") {
+            return None;
+        }
+        match &self.input {
+            Some(AttrInput::TokenTree(subtree)) => Some(subtree),
+            _ => None,
+        }
+    }
+
+    pub fn as_path(&self) -> Option<&SmolStr> {
+        if !self.is_simple_atom("path") {
+            return None;
+        }
+        match &self.input {
+            Some(AttrInput::Literal(it)) => Some(it),
+            _ => None,
+        }
+    }
+
+    pub fn is_cfg_enabled(&self, cfg_options: &CfgOptions) -> Option<bool> {
+        cfg_options.is_cfg_enabled(self.as_cfg()?)
+    }
+}

crates/ra_hir_def/src/db.rs

@@ -1,8 +1,12 @@
 //! Defines database & queries for name resolution.
+use std::sync::Arc;
 
+use hir_expand::{db::AstDatabase, HirFileId};
 use ra_db::{salsa, SourceDatabase};
 use ra_syntax::ast;
 
+use crate::nameres::raw::{ImportSourceMap, RawItems};
+
 #[salsa::query_group(InternDatabaseStorage)]
 pub trait InternDatabase: SourceDatabase {
     #[salsa::interned]
@@ -10,6 +14,8 @@ pub trait InternDatabase: SourceDatabase {
     #[salsa::interned]
     fn intern_struct(&self, loc: crate::ItemLoc<ast::StructDef>) -> crate::StructId;
     #[salsa::interned]
+    fn intern_union(&self, loc: crate::ItemLoc<ast::StructDef>) -> crate::UnionId;
+    #[salsa::interned]
     fn intern_enum(&self, loc: crate::ItemLoc<ast::EnumDef>) -> crate::EnumId;
     #[salsa::interned]
     fn intern_const(&self, loc: crate::ItemLoc<ast::ConstDef>) -> crate::ConstId;
@@ -20,3 +26,15 @@ pub trait InternDatabase: SourceDatabase {
     #[salsa::interned]
     fn intern_type_alias(&self, loc: crate::ItemLoc<ast::TypeAliasDef>) -> crate::TypeAliasId;
 }
+
+#[salsa::query_group(DefDatabase2Storage)]
+pub trait DefDatabase2: InternDatabase + AstDatabase {
+    #[salsa::invoke(RawItems::raw_items_with_source_map_query)]
+    fn raw_items_with_source_map(
+        &self,
+        file_id: HirFileId,
+    ) -> (Arc<RawItems>, Arc<ImportSourceMap>);
+
+    #[salsa::invoke(RawItems::raw_items_query)]
+    fn raw_items(&self, file_id: HirFileId) -> Arc<RawItems>;
+}

crates/ra_hir_def/src/either.rs

@@ -0,0 +1,54 @@
+//! FIXME: write short doc here
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub enum Either<A, B> {
+    A(A),
+    B(B),
+}
+
+impl<A, B> Either<A, B> {
+    pub fn either<R, F1, F2>(self, f1: F1, f2: F2) -> R
+    where
+        F1: FnOnce(A) -> R,
+        F2: FnOnce(B) -> R,
+    {
+        match self {
+            Either::A(a) => f1(a),
+            Either::B(b) => f2(b),
+        }
+    }
+    pub fn map<U, V, F1, F2>(self, f1: F1, f2: F2) -> Either<U, V>
+    where
+        F1: FnOnce(A) -> U,
+        F2: FnOnce(B) -> V,
+    {
+        match self {
+            Either::A(a) => Either::A(f1(a)),
+            Either::B(b) => Either::B(f2(b)),
+        }
+    }
+    pub fn map_a<U, F>(self, f: F) -> Either<U, B>
+    where
+        F: FnOnce(A) -> U,
+    {
+        self.map(f, |it| it)
+    }
+    pub fn a(self) -> Option<A> {
+        match self {
+            Either::A(it) => Some(it),
+            Either::B(_) => None,
+        }
+    }
+    pub fn b(self) -> Option<B> {
+        match self {
+            Either::A(_) => None,
+            Either::B(it) => Some(it),
+        }
+    }
+    pub fn as_ref(&self) -> Either<&A, &B> {
+        match self {
+            Either::A(it) => Either::A(it),
+            Either::B(it) => Either::B(it),
+        }
+    }
+}

crates/ra_hir_def/src/lib.rs

@@ -8,12 +8,20 @@
 //! actually true.
 
 pub mod db;
+pub mod either;
+pub mod attr;
+pub mod name;
+pub mod path;
+pub mod type_ref;
+
+// FIXME: this should be private
+pub mod nameres;
 
 use std::hash::{Hash, Hasher};
 
 use hir_expand::{ast_id_map::FileAstId, db::AstDatabase, AstId, HirFileId};
 use ra_arena::{impl_arena_id, RawId};
-use ra_db::{salsa, CrateId};
+use ra_db::{salsa, CrateId, FileId};
 use ra_syntax::{ast, AstNode, SyntaxNode};
 
 use crate::db::InternDatabase;
@@ -24,6 +32,68 @@ pub struct Source<T> {
     pub ast: T,
 }
 
+pub enum ModuleSource {
+    SourceFile(ast::SourceFile),
+    Module(ast::Module),
+}
+
+impl ModuleSource {
+    pub fn new(
+        db: &impl db::DefDatabase2,
+        file_id: Option<FileId>,
+        decl_id: Option<AstId<ast::Module>>,
+    ) -> ModuleSource {
+        match (file_id, decl_id) {
+            (Some(file_id), _) => {
+                let source_file = db.parse(file_id).tree();
+                ModuleSource::SourceFile(source_file)
+            }
+            (None, Some(item_id)) => {
+                let module = item_id.to_node(db);
+                assert!(module.item_list().is_some(), "expected inline module");
+                ModuleSource::Module(module)
+            }
+            (None, None) => panic!(),
+        }
+    }
+
+    // FIXME: this methods do not belong here
+    pub fn from_position(
+        db: &impl db::DefDatabase2,
+        position: ra_db::FilePosition,
+    ) -> ModuleSource {
+        let parse = db.parse(position.file_id);
+        match &ra_syntax::algo::find_node_at_offset::<ast::Module>(
+            parse.tree().syntax(),
+            position.offset,
+        ) {
+            Some(m) if !m.has_semi() => ModuleSource::Module(m.clone()),
+            _ => {
+                let source_file = parse.tree();
+                ModuleSource::SourceFile(source_file)
+            }
+        }
+    }
+
+    pub fn from_child_node(
+        db: &impl db::DefDatabase2,
+        file_id: FileId,
+        child: &SyntaxNode,
+    ) -> ModuleSource {
+        if let Some(m) = child.ancestors().filter_map(ast::Module::cast).find(|it| !it.has_semi()) {
+            ModuleSource::Module(m)
+        } else {
+            let source_file = db.parse(file_id).tree();
+            ModuleSource::SourceFile(source_file)
+        }
+    }
+
+    pub fn from_file_id(db: &impl db::DefDatabase2, file_id: FileId) -> ModuleSource {
+        let source_file = db.parse(file_id).tree();
+        ModuleSource::SourceFile(source_file)
+    }
+}
+
 impl<T> Source<T> {
     pub fn map<F: FnOnce(T) -> U, U>(self, f: F) -> Source<U> {
         Source { file_id: self.file_id, ast: f(self.ast) }
@@ -155,6 +225,18 @@ impl AstItemDef<ast::StructDef> for StructId {
     }
 }
 
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct UnionId(salsa::InternId);
+impl_intern_key!(UnionId);
+impl AstItemDef<ast::StructDef> for UnionId {
+    fn intern(db: &impl InternDatabase, loc: ItemLoc<ast::StructDef>) -> Self {
+        db.intern_union(loc)
+    }
+    fn lookup_intern(self, db: &impl InternDatabase) -> ItemLoc<ast::StructDef> {
+        db.lookup_intern_union(self)
+    }
+}
+
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct EnumId(salsa::InternId);
 impl_intern_key!(EnumId);
@@ -167,6 +249,17 @@ impl AstItemDef<ast::EnumDef> for EnumId {
     }
 }
 
+// FIXME: rename to `VariantId`, only enums can ave variants
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct EnumVariantId {
+    parent: EnumId,
+    local_id: LocalEnumVariantId,
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub(crate) struct LocalEnumVariantId(RawId);
+impl_arena_id!(LocalEnumVariantId);
+
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct ConstId(salsa::InternId);
 impl_intern_key!(ConstId);

crates/ra_hir_def/src/name.rs

@@ -0,0 +1,142 @@
+//! FIXME: write short doc here
+
+use std::fmt;
+
+use ra_syntax::{ast, SmolStr};
+
+/// `Name` is a wrapper around string, which is used in hir for both references
+/// and declarations. In theory, names should also carry hygiene info, but we are
+/// not there yet!
+#[derive(Debug, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
+pub struct Name(Repr);
+
+#[derive(Debug, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
+enum Repr {
+    Text(SmolStr),
+    TupleField(usize),
+}
+
+impl fmt::Display for Name {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match &self.0 {
+            Repr::Text(text) => fmt::Display::fmt(&text, f),
+            Repr::TupleField(idx) => fmt::Display::fmt(&idx, f),
+        }
+    }
+}
+
+impl Name {
+    /// Note: this is private to make creating name from random string hard.
+    /// Hopefully, this should allow us to integrate hygiene cleaner in the
+    /// future, and to switch to interned representation of names.
+    const fn new_text(text: SmolStr) -> Name {
+        Name(Repr::Text(text))
+    }
+
+    pub fn new_tuple_field(idx: usize) -> Name {
+        Name(Repr::TupleField(idx))
+    }
+
+    /// Shortcut to create inline plain text name
+    const fn new_inline_ascii(len: usize, text: &[u8]) -> Name {
+        Name::new_text(SmolStr::new_inline_from_ascii(len, text))
+    }
+
+    /// Resolve a name from the text of token.
+    fn resolve(raw_text: &SmolStr) -> Name {
+        let raw_start = "r#";
+        if raw_text.as_str().starts_with(raw_start) {
+            Name::new_text(SmolStr::new(&raw_text[raw_start.len()..]))
+        } else {
+            Name::new_text(raw_text.clone())
+        }
+    }
+
+    pub fn missing() -> Name {
+        Name::new_text("[missing name]".into())
+    }
+
+    pub fn as_tuple_index(&self) -> Option<usize> {
+        match self.0 {
+            Repr::TupleField(idx) => Some(idx),
+            _ => None,
+        }
+    }
+}
+
+pub trait AsName {
+    fn as_name(&self) -> Name;
+}
+
+impl AsName for ast::NameRef {
+    fn as_name(&self) -> Name {
+        match self.as_tuple_field() {
+            Some(idx) => Name::new_tuple_field(idx),
+            None => Name::resolve(self.text()),
+        }
+    }
+}
+
+impl AsName for ast::Name {
+    fn as_name(&self) -> Name {
+        Name::resolve(self.text())
+    }
+}
+
+impl AsName for ast::FieldKind {
+    fn as_name(&self) -> Name {
+        match self {
+            ast::FieldKind::Name(nr) => nr.as_name(),
+            ast::FieldKind::Index(idx) => Name::new_tuple_field(idx.text().parse().unwrap()),
+        }
+    }
+}
+
+impl AsName for ra_db::Dependency {
+    fn as_name(&self) -> Name {
+        Name::new_text(self.name.clone())
+    }
+}
+
+// Primitives
+pub const ISIZE: Name = Name::new_inline_ascii(5, b"isize");
+pub const I8: Name = Name::new_inline_ascii(2, b"i8");
+pub const I16: Name = Name::new_inline_ascii(3, b"i16");
+pub const I32: Name = Name::new_inline_ascii(3, b"i32");
+pub const I64: Name = Name::new_inline_ascii(3, b"i64");
+pub const I128: Name = Name::new_inline_ascii(4, b"i128");
+pub const USIZE: Name = Name::new_inline_ascii(5, b"usize");
+pub const U8: Name = Name::new_inline_ascii(2, b"u8");
+pub const U16: Name = Name::new_inline_ascii(3, b"u16");
+pub const U32: Name = Name::new_inline_ascii(3, b"u32");
+pub const U64: Name = Name::new_inline_ascii(3, b"u64");
+pub const U128: Name = Name::new_inline_ascii(4, b"u128");
+pub const F32: Name = Name::new_inline_ascii(3, b"f32");
+pub const F64: Name = Name::new_inline_ascii(3, b"f64");
+pub const BOOL: Name = Name::new_inline_ascii(4, b"bool");
+pub const CHAR: Name = Name::new_inline_ascii(4, b"char");
+pub const STR: Name = Name::new_inline_ascii(3, b"str");
+
+// Special names
+pub const SELF_PARAM: Name = Name::new_inline_ascii(4, b"self");
+pub const SELF_TYPE: Name = Name::new_inline_ascii(4, b"Self");
+pub const MACRO_RULES: Name = Name::new_inline_ascii(11, b"macro_rules");
+
+// Components of known path (value or mod name)
+pub const STD: Name = Name::new_inline_ascii(3, b"std");
+pub const ITER: Name = Name::new_inline_ascii(4, b"iter");
+pub const OPS: Name = Name::new_inline_ascii(3, b"ops");
+pub const FUTURE: Name = Name::new_inline_ascii(6, b"future");
+pub const RESULT: Name = Name::new_inline_ascii(6, b"result");
+pub const BOXED: Name = Name::new_inline_ascii(5, b"boxed");
+
+// Components of known path (type name)
+pub const INTO_ITERATOR_TYPE: Name = Name::new_inline_ascii(12, b"IntoIterator");
+pub const ITEM_TYPE: Name = Name::new_inline_ascii(4, b"Item");
+pub const TRY_TYPE: Name = Name::new_inline_ascii(3, b"Try");
+pub const OK_TYPE: Name = Name::new_inline_ascii(2, b"Ok");
+pub const FUTURE_TYPE: Name = Name::new_inline_ascii(6, b"Future");
+pub const RESULT_TYPE: Name = Name::new_inline_ascii(6, b"Result");
+pub const OUTPUT_TYPE: Name = Name::new_inline_ascii(6, b"Output");
+pub const TARGET_TYPE: Name = Name::new_inline_ascii(6, b"Target");
+pub const BOX_TYPE: Name = Name::new_inline_ascii(3, b"Box");

crates/ra_hir_def/src/nameres.rs

@@ -0,0 +1 @@
+pub mod raw;

crates/ra_hir_def/src/nameres/raw.rs

@@ -2,6 +2,7 @@
 
 use std::{ops::Index, sync::Arc};
 
+use hir_expand::{ast_id_map::AstIdMap, db::AstDatabase};
 use ra_arena::{impl_arena_id, map::ArenaMap, Arena, RawId};
 use ra_syntax::{
     ast::{self, AttrsOwner, NameOwner},
@@ -11,8 +12,11 @@ use test_utils::tested_by;
 
 use crate::{
     attr::Attr,
-    db::{AstDatabase, DefDatabase},
+    db::DefDatabase2,
-    AsName, AstIdMap, Either, FileAstId, HirFileId, ModuleSource, Name, Path, Source,
+    either::Either,
+    name::{AsName, Name},
+    path::Path,
+    FileAstId, HirFileId, ModuleSource, Source,
 };
 
 /// `RawItems` is a set of top-level items in a file (except for impls).
@@ -48,7 +52,7 @@ impl ImportSourceMap {
         self.map.insert(import, ptr)
     }
 
-    pub(crate) fn get(&self, source: &ModuleSource, import: ImportId) -> ImportSource {
+    pub fn get(&self, source: &ModuleSource, import: ImportId) -> ImportSource {
         let file = match source {
             ModuleSource::SourceFile(file) => file.clone(),
             ModuleSource::Module(m) => m.syntax().ancestors().find_map(SourceFile::cast).unwrap(),
@@ -60,14 +64,14 @@ impl ImportSourceMap {
 
 impl RawItems {
     pub(crate) fn raw_items_query(
-        db: &(impl DefDatabase + AstDatabase),
+        db: &(impl DefDatabase2 + AstDatabase),
         file_id: HirFileId,
     ) -> Arc<RawItems> {
         db.raw_items_with_source_map(file_id).0
     }
 
     pub(crate) fn raw_items_with_source_map_query(
-        db: &(impl DefDatabase + AstDatabase),
+        db: &(impl DefDatabase2 + AstDatabase),
         file_id: HirFileId,
     ) -> (Arc<RawItems>, Arc<ImportSourceMap>) {
         let mut collector = RawItemsCollector {
@@ -87,7 +91,7 @@ impl RawItems {
         (Arc::new(collector.raw_items), Arc::new(collector.source_map))
     }
 
-    pub(super) fn items(&self) -> &[RawItem] {
+    pub fn items(&self) -> &[RawItem] {
         &self.items
     }
 }
@@ -124,19 +128,19 @@ impl Index<Macro> for RawItems {
 type Attrs = Option<Arc<[Attr]>>;
 
 #[derive(Debug, PartialEq, Eq, Clone)]
-pub(super) struct RawItem {
+pub struct RawItem {
     attrs: Attrs,
-    pub(super) kind: RawItemKind,
+    pub kind: RawItemKind,
 }
 
 impl RawItem {
-    pub(super) fn attrs(&self) -> &[Attr] {
+    pub fn attrs(&self) -> &[Attr] {
         self.attrs.as_ref().map_or(&[], |it| &*it)
     }
 }
 
 #[derive(Debug, PartialEq, Eq, Clone, Copy)]
-pub(super) enum RawItemKind {
+pub enum RawItemKind {
     Module(Module),
     Import(ImportId),
     Def(Def),
@@ -144,11 +148,11 @@ pub(super) enum RawItemKind {
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub(super) struct Module(RawId);
+pub struct Module(RawId);
 impl_arena_id!(Module);
 
 #[derive(Debug, PartialEq, Eq)]
-pub(super) enum ModuleData {
+pub enum ModuleData {
     Declaration { name: Name, ast_id: FileAstId<ast::Module> },
     Definition { name: Name, ast_id: FileAstId<ast::Module>, items: Vec<RawItem> },
 }
@@ -159,26 +163,26 @@ impl_arena_id!(ImportId);
 
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct ImportData {
-    pub(super) path: Path,
+    pub path: Path,
-    pub(super) alias: Option<Name>,
+    pub alias: Option<Name>,
-    pub(super) is_glob: bool,
+    pub is_glob: bool,
-    pub(super) is_prelude: bool,
+    pub is_prelude: bool,
-    pub(super) is_extern_crate: bool,
+    pub is_extern_crate: bool,
-    pub(super) is_macro_use: bool,
+    pub is_macro_use: bool,
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub(super) struct Def(RawId);
+pub struct Def(RawId);
 impl_arena_id!(Def);
 
 #[derive(Debug, PartialEq, Eq)]
-pub(super) struct DefData {
+pub struct DefData {
-    pub(super) name: Name,
+    pub name: Name,
-    pub(super) kind: DefKind,
+    pub kind: DefKind,
 }
 
 #[derive(Debug, PartialEq, Eq, Clone, Copy)]
-pub(super) enum DefKind {
+pub enum DefKind {
     Function(FileAstId<ast::FnDef>),
     Struct(FileAstId<ast::StructDef>),
     Union(FileAstId<ast::StructDef>),
@@ -190,15 +194,15 @@ pub(super) enum DefKind {
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub(super) struct Macro(RawId);
+pub struct Macro(RawId);
 impl_arena_id!(Macro);
 
 #[derive(Debug, PartialEq, Eq)]
-pub(super) struct MacroData {
+pub struct MacroData {
-    pub(super) ast_id: FileAstId<ast::MacroCall>,
+    pub ast_id: FileAstId<ast::MacroCall>,
-    pub(super) path: Path,
+    pub path: Path,
-    pub(super) name: Option<Name>,
+    pub name: Option<Name>,
-    pub(super) export: bool,
+    pub export: bool,
 }
 
 struct RawItemsCollector<DB> {

crates/ra_hir_def/src/path.rs

@@ -0,0 +1,423 @@
+//! FIXME: write short doc here
+
+use std::{iter, sync::Arc};
+
+use hir_expand::db::AstDatabase;
+use ra_db::CrateId;
+use ra_syntax::{
+    ast::{self, NameOwner, TypeAscriptionOwner},
+    AstNode,
+};
+
+use crate::{
+    name::{self, AsName, Name},
+    type_ref::TypeRef,
+    Source,
+};
+
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub struct Path {
+    pub kind: PathKind,
+    pub segments: Vec<PathSegment>,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub struct PathSegment {
+    pub name: Name,
+    pub args_and_bindings: Option<Arc<GenericArgs>>,
+}
+
+/// Generic arguments to a path segment (e.g. the `i32` in `Option<i32>`). This
+/// can (in the future) also include bindings of associated types, like in
+/// `Iterator<Item = Foo>`.
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub struct GenericArgs {
+    pub args: Vec<GenericArg>,
+    /// This specifies whether the args contain a Self type as the first
+    /// element. This is the case for path segments like `<T as Trait>`, where
+    /// `T` is actually a type parameter for the path `Trait` specifying the
+    /// Self type. Otherwise, when we have a path `Trait<X, Y>`, the Self type
+    /// is left out.
+    pub has_self_type: bool,
+    /// Associated type bindings like in `Iterator<Item = T>`.
+    pub bindings: Vec<(Name, TypeRef)>,
+}
+
+/// A single generic argument.
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub enum GenericArg {
+    Type(TypeRef),
+    // or lifetime...
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub enum PathKind {
+    Plain,
+    Self_,
+    Super,
+    Crate,
+    // Absolute path
+    Abs,
+    // Type based path like `<T>::foo`
+    Type(Box<TypeRef>),
+    // `$crate` from macro expansion
+    DollarCrate(CrateId),
+}
+
+impl Path {
+    /// Calls `cb` with all paths, represented by this use item.
+    pub fn expand_use_item(
+        item_src: Source<ast::UseItem>,
+        db: &impl AstDatabase,
+        mut cb: impl FnMut(Path, &ast::UseTree, bool, Option<Name>),
+    ) {
+        if let Some(tree) = item_src.ast.use_tree() {
+            expand_use_tree(None, tree, &|| item_src.file_id.macro_crate(db), &mut cb);
+        }
+    }
+
+    pub fn from_simple_segments(kind: PathKind, segments: impl IntoIterator<Item = Name>) -> Path {
+        Path {
+            kind,
+            segments: segments
+                .into_iter()
+                .map(|name| PathSegment { name, args_and_bindings: None })
+                .collect(),
+        }
+    }
+
+    /// Converts an `ast::Path` to `Path`. Works with use trees.
+    /// DEPRECATED: It does not handle `$crate` from macro call.
+    pub fn from_ast(path: ast::Path) -> Option<Path> {
+        Path::parse(path, &|| None)
+    }
+
+    /// Converts an `ast::Path` to `Path`. Works with use trees.
+    /// It correctly handles `$crate` based path from macro call.
+    pub fn from_src(source: Source<ast::Path>, db: &impl AstDatabase) -> Option<Path> {
+        let file_id = source.file_id;
+        Path::parse(source.ast, &|| file_id.macro_crate(db))
+    }
+
+    fn parse(mut path: ast::Path, macro_crate: &impl Fn() -> Option<CrateId>) -> Option<Path> {
+        let mut kind = PathKind::Plain;
+        let mut segments = Vec::new();
+        loop {
+            let segment = path.segment()?;
+
+            if segment.has_colon_colon() {
+                kind = PathKind::Abs;
+            }
+
+            match segment.kind()? {
+                ast::PathSegmentKind::Name(name) => {
+                    if name.text() == "$crate" {
+                        if let Some(macro_crate) = macro_crate() {
+                            kind = PathKind::DollarCrate(macro_crate);
+                            break;
+                        }
+                    }
+
+                    let args = segment
+                        .type_arg_list()
+                        .and_then(GenericArgs::from_ast)
+                        .or_else(|| {
+                            GenericArgs::from_fn_like_path_ast(
+                                segment.param_list(),
+                                segment.ret_type(),
+                            )
+                        })
+                        .map(Arc::new);
+                    let segment = PathSegment { name: name.as_name(), args_and_bindings: args };
+                    segments.push(segment);
+                }
+                ast::PathSegmentKind::Type { type_ref, trait_ref } => {
+                    assert!(path.qualifier().is_none()); // this can only occur at the first segment
+
+                    let self_type = TypeRef::from_ast(type_ref?);
+
+                    match trait_ref {
+                        // <T>::foo
+                        None => {
+                            kind = PathKind::Type(Box::new(self_type));
+                        }
+                        // <T as Trait<A>>::Foo desugars to Trait<Self=T, A>::Foo
+                        Some(trait_ref) => {
+                            let path = Path::parse(trait_ref.path()?, macro_crate)?;
+                            kind = path.kind;
+                            let mut prefix_segments = path.segments;
+                            prefix_segments.reverse();
+                            segments.extend(prefix_segments);
+                            // Insert the type reference (T in the above example) as Self parameter for the trait
+                            let mut last_segment = segments.last_mut()?;
+                            if last_segment.args_and_bindings.is_none() {
+                                last_segment.args_and_bindings =
+                                    Some(Arc::new(GenericArgs::empty()));
+                            };
+                            let args = last_segment.args_and_bindings.as_mut().unwrap();
+                            let mut args_inner = Arc::make_mut(args);
+                            args_inner.has_self_type = true;
+                            args_inner.args.insert(0, GenericArg::Type(self_type));
+                        }
+                    }
+                }
+                ast::PathSegmentKind::CrateKw => {
+                    kind = PathKind::Crate;
+                    break;
+                }
+                ast::PathSegmentKind::SelfKw => {
+                    kind = PathKind::Self_;
+                    break;
+                }
+                ast::PathSegmentKind::SuperKw => {
+                    kind = PathKind::Super;
+                    break;
+                }
+            }
+            path = match qualifier(&path) {
+                Some(it) => it,
+                None => break,
+            };
+        }
+        segments.reverse();
+        return Some(Path { kind, segments });
+
+        fn qualifier(path: &ast::Path) -> Option<ast::Path> {
+            if let Some(q) = path.qualifier() {
+                return Some(q);
+            }
+            // FIXME: this bottom up traversal is not too precise.
+            // Should we handle do a top-down analysis, recording results?
+            let use_tree_list = path.syntax().ancestors().find_map(ast::UseTreeList::cast)?;
+            let use_tree = use_tree_list.parent_use_tree();
+            use_tree.path()
+        }
+    }
+
+    /// Converts an `ast::NameRef` into a single-identifier `Path`.
+    pub fn from_name_ref(name_ref: &ast::NameRef) -> Path {
+        name_ref.as_name().into()
+    }
+
+    /// `true` is this path is a single identifier, like `foo`
+    pub fn is_ident(&self) -> bool {
+        self.kind == PathKind::Plain && self.segments.len() == 1
+    }
+
+    /// `true` if this path is just a standalone `self`
+    pub fn is_self(&self) -> bool {
+        self.kind == PathKind::Self_ && self.segments.is_empty()
+    }
+
+    /// If this path is a single identifier, like `foo`, return its name.
+    pub fn as_ident(&self) -> Option<&Name> {
+        if self.kind != PathKind::Plain || self.segments.len() > 1 {
+            return None;
+        }
+        self.segments.first().map(|s| &s.name)
+    }
+
+    pub fn expand_macro_expr(&self) -> Option<Name> {
+        self.as_ident().and_then(|name| Some(name.clone()))
+    }
+
+    pub fn is_type_relative(&self) -> bool {
+        match self.kind {
+            PathKind::Type(_) => true,
+            _ => false,
+        }
+    }
+}
+
+impl GenericArgs {
+    pub fn from_ast(node: ast::TypeArgList) -> Option<GenericArgs> {
+        let mut args = Vec::new();
+        for type_arg in node.type_args() {
+            let type_ref = TypeRef::from_ast_opt(type_arg.type_ref());
+            args.push(GenericArg::Type(type_ref));
+        }
+        // lifetimes ignored for now
+        let mut bindings = Vec::new();
+        for assoc_type_arg in node.assoc_type_args() {
+            if let Some(name_ref) = assoc_type_arg.name_ref() {
+                let name = name_ref.as_name();
+                let type_ref = TypeRef::from_ast_opt(assoc_type_arg.type_ref());
+                bindings.push((name, type_ref));
+            }
+        }
+        if args.is_empty() && bindings.is_empty() {
+            None
+        } else {
+            Some(GenericArgs { args, has_self_type: false, bindings })
+        }
+    }
+
+    /// Collect `GenericArgs` from the parts of a fn-like path, i.e. `Fn(X, Y)
+    /// -> Z` (which desugars to `Fn<(X, Y), Output=Z>`).
+    pub(crate) fn from_fn_like_path_ast(
+        params: Option<ast::ParamList>,
+        ret_type: Option<ast::RetType>,
+    ) -> Option<GenericArgs> {
+        let mut args = Vec::new();
+        let mut bindings = Vec::new();
+        if let Some(params) = params {
+            let mut param_types = Vec::new();
+            for param in params.params() {
+                let type_ref = TypeRef::from_ast_opt(param.ascribed_type());
+                param_types.push(type_ref);
+            }
+            let arg = GenericArg::Type(TypeRef::Tuple(param_types));
+            args.push(arg);
+        }
+        if let Some(ret_type) = ret_type {
+            let type_ref = TypeRef::from_ast_opt(ret_type.type_ref());
+            bindings.push((name::OUTPUT_TYPE, type_ref))
+        }
+        if args.is_empty() && bindings.is_empty() {
+            None
+        } else {
+            Some(GenericArgs { args, has_self_type: false, bindings })
+        }
+    }
+
+    pub(crate) fn empty() -> GenericArgs {
+        GenericArgs { args: Vec::new(), has_self_type: false, bindings: Vec::new() }
+    }
+}
+
+impl From<Name> for Path {
+    fn from(name: Name) -> Path {
+        Path::from_simple_segments(PathKind::Plain, iter::once(name))
+    }
+}
+
+fn expand_use_tree(
+    prefix: Option<Path>,
+    tree: ast::UseTree,
+    macro_crate: &impl Fn() -> Option<CrateId>,
+    cb: &mut impl FnMut(Path, &ast::UseTree, bool, Option<Name>),
+) {
+    if let Some(use_tree_list) = tree.use_tree_list() {
+        let prefix = match tree.path() {
+            // E.g. use something::{{{inner}}};
+            None => prefix,
+            // E.g. `use something::{inner}` (prefix is `None`, path is `something`)
+            // or `use something::{path::{inner::{innerer}}}` (prefix is `something::path`, path is `inner`)
+            Some(path) => match convert_path(prefix, path, macro_crate) {
+                Some(it) => Some(it),
+                None => return, // FIXME: report errors somewhere
+            },
+        };
+        for child_tree in use_tree_list.use_trees() {
+            expand_use_tree(prefix.clone(), child_tree, macro_crate, cb);
+        }
+    } else {
+        let alias = tree.alias().and_then(|a| a.name()).map(|a| a.as_name());
+        if let Some(ast_path) = tree.path() {
+            // Handle self in a path.
+            // E.g. `use something::{self, <...>}`
+            if ast_path.qualifier().is_none() {
+                if let Some(segment) = ast_path.segment() {
+                    if segment.kind() == Some(ast::PathSegmentKind::SelfKw) {
+                        if let Some(prefix) = prefix {
+                            cb(prefix, &tree, false, alias);
+                            return;
+                        }
+                    }
+                }
+            }
+            if let Some(path) = convert_path(prefix, ast_path, macro_crate) {
+                let is_glob = tree.has_star();
+                cb(path, &tree, is_glob, alias)
+            }
+            // FIXME: report errors somewhere
+            // We get here if we do
+        }
+    }
+}
+
+fn convert_path(
+    prefix: Option<Path>,
+    path: ast::Path,
+    macro_crate: &impl Fn() -> Option<CrateId>,
+) -> Option<Path> {
+    let prefix = if let Some(qual) = path.qualifier() {
+        Some(convert_path(prefix, qual, macro_crate)?)
+    } else {
+        prefix
+    };
+
+    let segment = path.segment()?;
+    let res = match segment.kind()? {
+        ast::PathSegmentKind::Name(name) => {
+            if name.text() == "$crate" {
+                if let Some(krate) = macro_crate() {
+                    return Some(Path::from_simple_segments(
+                        PathKind::DollarCrate(krate),
+                        iter::empty(),
+                    ));
+                }
+            }
+
+            // no type args in use
+            let mut res = prefix
+                .unwrap_or_else(|| Path { kind: PathKind::Plain, segments: Vec::with_capacity(1) });
+            res.segments.push(PathSegment {
+                name: name.as_name(),
+                args_and_bindings: None, // no type args in use
+            });
+            res
+        }
+        ast::PathSegmentKind::CrateKw => {
+            if prefix.is_some() {
+                return None;
+            }
+            Path::from_simple_segments(PathKind::Crate, iter::empty())
+        }
+        ast::PathSegmentKind::SelfKw => {
+            if prefix.is_some() {
+                return None;
+            }
+            Path::from_simple_segments(PathKind::Self_, iter::empty())
+        }
+        ast::PathSegmentKind::SuperKw => {
+            if prefix.is_some() {
+                return None;
+            }
+            Path::from_simple_segments(PathKind::Super, iter::empty())
+        }
+        ast::PathSegmentKind::Type { .. } => {
+            // not allowed in imports
+            return None;
+        }
+    };
+    Some(res)
+}
+
+pub mod known {
+    use super::{Path, PathKind};
+    use crate::name;
+
+    pub fn std_iter_into_iterator() -> Path {
+        Path::from_simple_segments(
+            PathKind::Abs,
+            vec![name::STD, name::ITER, name::INTO_ITERATOR_TYPE],
+        )
+    }
+
+    pub fn std_ops_try() -> Path {
+        Path::from_simple_segments(PathKind::Abs, vec![name::STD, name::OPS, name::TRY_TYPE])
+    }
+
+    pub fn std_result_result() -> Path {
+        Path::from_simple_segments(PathKind::Abs, vec![name::STD, name::RESULT, name::RESULT_TYPE])
+    }
+
+    pub fn std_future_future() -> Path {
+        Path::from_simple_segments(PathKind::Abs, vec![name::STD, name::FUTURE, name::FUTURE_TYPE])
+    }
+
+    pub fn std_boxed_box() -> Path {
+        Path::from_simple_segments(PathKind::Abs, vec![name::STD, name::BOXED, name::BOX_TYPE])
+    }
+}

crates/ra_hir_def/src/type_ref.rs

@@ -0,0 +1,162 @@
+//! HIR for references to types. Paths in these are not yet resolved. They can
+//! be directly created from an ast::TypeRef, without further queries.
+
+use ra_syntax::ast::{self, TypeAscriptionOwner, TypeBoundsOwner};
+
+use crate::path::Path;
+
+#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
+pub enum Mutability {
+    Shared,
+    Mut,
+}
+
+impl Mutability {
+    pub fn from_mutable(mutable: bool) -> Mutability {
+        if mutable {
+            Mutability::Mut
+        } else {
+            Mutability::Shared
+        }
+    }
+
+    pub fn as_keyword_for_ref(self) -> &'static str {
+        match self {
+            Mutability::Shared => "",
+            Mutability::Mut => "mut ",
+        }
+    }
+
+    pub fn as_keyword_for_ptr(self) -> &'static str {
+        match self {
+            Mutability::Shared => "const ",
+            Mutability::Mut => "mut ",
+        }
+    }
+}
+
+/// Compare ty::Ty
+#[derive(Clone, PartialEq, Eq, Hash, Debug)]
+pub enum TypeRef {
+    Never,
+    Placeholder,
+    Tuple(Vec<TypeRef>),
+    Path(Path),
+    RawPtr(Box<TypeRef>, Mutability),
+    Reference(Box<TypeRef>, Mutability),
+    Array(Box<TypeRef> /*, Expr*/),
+    Slice(Box<TypeRef>),
+    /// A fn pointer. Last element of the vector is the return type.
+    Fn(Vec<TypeRef>),
+    // For
+    ImplTrait(Vec<TypeBound>),
+    DynTrait(Vec<TypeBound>),
+    Error,
+}
+
+#[derive(Clone, PartialEq, Eq, Hash, Debug)]
+pub enum TypeBound {
+    Path(Path),
+    // also for<> bounds
+    // also Lifetimes
+    Error,
+}
+
+impl TypeRef {
+    /// Converts an `ast::TypeRef` to a `hir::TypeRef`.
+    pub fn from_ast(node: ast::TypeRef) -> Self {
+        match node {
+            ast::TypeRef::ParenType(inner) => TypeRef::from_ast_opt(inner.type_ref()),
+            ast::TypeRef::TupleType(inner) => {
+                TypeRef::Tuple(inner.fields().map(TypeRef::from_ast).collect())
+            }
+            ast::TypeRef::NeverType(..) => TypeRef::Never,
+            ast::TypeRef::PathType(inner) => {
+                // FIXME: Use `Path::from_src`
+                inner.path().and_then(Path::from_ast).map(TypeRef::Path).unwrap_or(TypeRef::Error)
+            }
+            ast::TypeRef::PointerType(inner) => {
+                let inner_ty = TypeRef::from_ast_opt(inner.type_ref());
+                let mutability = Mutability::from_mutable(inner.is_mut());
+                TypeRef::RawPtr(Box::new(inner_ty), mutability)
+            }
+            ast::TypeRef::ArrayType(inner) => {
+                TypeRef::Array(Box::new(TypeRef::from_ast_opt(inner.type_ref())))
+            }
+            ast::TypeRef::SliceType(inner) => {
+                TypeRef::Slice(Box::new(TypeRef::from_ast_opt(inner.type_ref())))
+            }
+            ast::TypeRef::ReferenceType(inner) => {
+                let inner_ty = TypeRef::from_ast_opt(inner.type_ref());
+                let mutability = Mutability::from_mutable(inner.is_mut());
+                TypeRef::Reference(Box::new(inner_ty), mutability)
+            }
+            ast::TypeRef::PlaceholderType(_inner) => TypeRef::Placeholder,
+            ast::TypeRef::FnPointerType(inner) => {
+                let ret_ty = TypeRef::from_ast_opt(inner.ret_type().and_then(|rt| rt.type_ref()));
+                let mut params = if let Some(pl) = inner.param_list() {
+                    pl.params().map(|p| p.ascribed_type()).map(TypeRef::from_ast_opt).collect()
+                } else {
+                    Vec::new()
+                };
+                params.push(ret_ty);
+                TypeRef::Fn(params)
+            }
+            // for types are close enough for our purposes to the inner type for now...
+            ast::TypeRef::ForType(inner) => TypeRef::from_ast_opt(inner.type_ref()),
+            ast::TypeRef::ImplTraitType(inner) => {
+                TypeRef::ImplTrait(type_bounds_from_ast(inner.type_bound_list()))
+            }
+            ast::TypeRef::DynTraitType(inner) => {
+                TypeRef::DynTrait(type_bounds_from_ast(inner.type_bound_list()))
+            }
+        }
+    }
+
+    pub fn from_ast_opt(node: Option<ast::TypeRef>) -> Self {
+        if let Some(node) = node {
+            TypeRef::from_ast(node)
+        } else {
+            TypeRef::Error
+        }
+    }
+
+    pub fn unit() -> TypeRef {
+        TypeRef::Tuple(Vec::new())
+    }
+}
+
+pub(crate) fn type_bounds_from_ast(type_bounds_opt: Option<ast::TypeBoundList>) -> Vec<TypeBound> {
+    if let Some(type_bounds) = type_bounds_opt {
+        type_bounds.bounds().map(TypeBound::from_ast).collect()
+    } else {
+        vec![]
+    }
+}
+
+impl TypeBound {
+    pub fn from_ast(node: ast::TypeBound) -> Self {
+        match node.kind() {
+            ast::TypeBoundKind::PathType(path_type) => {
+                let path = match path_type.path() {
+                    Some(p) => p,
+                    None => return TypeBound::Error,
+                };
+                // FIXME: Use `Path::from_src`
+                let path = match Path::from_ast(path) {
+                    Some(p) => p,
+                    None => return TypeBound::Error,
+                };
+                TypeBound::Path(path)
+            }
+            ast::TypeBoundKind::ForType(_) | ast::TypeBoundKind::Lifetime(_) => TypeBound::Error,
+        }
+    }
+
+    pub fn as_path(&self) -> Option<&Path> {
+        match self {
+            TypeBound::Path(p) => Some(p),
+            _ => None,
+        }
+    }
+}

crates/ra_hir_expand/src/lib.rs

@@ -12,7 +12,7 @@ use std::hash::{Hash, Hasher};
 use ra_db::{salsa, CrateId, FileId};
 use ra_syntax::ast::{self, AstNode};
 
-use crate::{ast_id_map::FileAstId, db::AstDatabase};
+use crate::ast_id_map::FileAstId;
 
 /// Input to the analyzer is a set of files, where each file is identified by
 /// `FileId` and contains source code. However, another source of source code in
@@ -50,7 +50,7 @@ impl From<MacroFile> for HirFileId {
 impl HirFileId {
     /// For macro-expansion files, returns the file original source file the
     /// expansion originated from.
-    pub fn original_file(self, db: &dyn AstDatabase) -> FileId {
+    pub fn original_file(self, db: &dyn db::AstDatabase) -> FileId {
         match self.0 {
             HirFileIdRepr::FileId(file_id) => file_id,
             HirFileIdRepr::MacroFile(macro_file) => {
@@ -61,7 +61,7 @@ impl HirFileId {
     }
 
     /// Get the crate which the macro lives in, if it is a macro file.
-    pub fn macro_crate(self, db: &dyn AstDatabase) -> Option<CrateId> {
+    pub fn macro_crate(self, db: &dyn db::AstDatabase) -> Option<CrateId> {
         match self.0 {
             HirFileIdRepr::FileId(_) => None,
             HirFileIdRepr::MacroFile(macro_file) => {
@@ -154,7 +154,7 @@ impl<N: AstNode> AstId<N> {
         self.file_id
     }
 
-    pub fn to_node(&self, db: &dyn AstDatabase) -> N {
+    pub fn to_node(&self, db: &dyn db::AstDatabase) -> N {
         let root = db.parse_or_expand(self.file_id).unwrap();
         db.ast_id_map(self.file_id).get(self.file_ast_id).to_node(&root)
     }