Store a resolved def on hir::PathSegment

src/librustc/hir/lowering.rs

@@ -143,8 +143,13 @@ pub struct LoweringContext<'a> {
 }
 
 pub trait Resolver {
-    /// Resolve a hir path generated by the lowerer when expanding `for`, `if let`, etc.
+    /// Resolve a path generated by the lowerer when expanding `for`, `if let`, etc.
-    fn resolve_hir_path(&mut self, path: &mut hir::Path, is_value: bool);
+    fn resolve_hir_path(
+        &mut self,
+        path: &ast::Path,
+        args: Option<P<hir::GenericArgs>>,
+        is_value: bool,
+    ) -> hir::Path;
 
     /// Obtain the resolution for a node id
     fn get_resolution(&mut self, id: NodeId) -> Option<PathResolution>;
@@ -163,7 +168,7 @@ pub trait Resolver {
         span: Span,
         crate_root: Option<&str>,
         components: &[&str],
-        params: Option<P<hir::GenericArgs>>,
+        args: Option<P<hir::GenericArgs>>,
         is_value: bool,
     ) -> hir::Path;
 }
@@ -1380,6 +1385,7 @@ impl<'a> LoweringContext<'a> {
             // does not actually exist in the AST.
             lctx.items.insert(exist_ty_id.node_id, exist_ty_item);
 
+            let def = Def::Existential(DefId::local(exist_ty_def_index));
             // `impl Trait` now just becomes `Foo<'a, 'b, ..>`
             hir::TyKind::Def(hir::ItemId { id: exist_ty_id.node_id }, lifetimes)
         })
@@ -1852,8 +1858,10 @@ impl<'a> LoweringContext<'a> {
             }
         }
 
+        let def = self.expect_full_def(segment.id);
         hir::PathSegment::new(
             segment.ident,
+            Some(def),
             generic_args,
             infer_types,
         )

src/librustc/hir/mod.rs

@@ -347,6 +347,7 @@ impl fmt::Display for Path {
 pub struct PathSegment {
     /// The identifier portion of this path segment.
     pub ident: Ident,
+    pub def: Option<Def>,
 
     /// Type/lifetime parameters attached to this path. They come in
     /// two flavors: `Path<A,B,C>` and `Path(A,B) -> C`. Note that
@@ -367,14 +368,16 @@ impl PathSegment {
     pub fn from_ident(ident: Ident) -> PathSegment {
         PathSegment {
             ident,
+            def: None,
             infer_types: true,
             args: None,
         }
     }
 
-    pub fn new(ident: Ident, args: GenericArgs, infer_types: bool) -> Self {
+    pub fn new(ident: Ident, def: Option<Def>, args: GenericArgs, infer_types: bool) -> Self {
         PathSegment {
             ident,
+            def,
             infer_types,
             args: if args.is_empty() {
                 None

src/librustc/ich/impls_hir.rs

@@ -174,6 +174,7 @@ impl_stable_hash_for!(struct hir::Path {
 
 impl_stable_hash_for!(struct hir::PathSegment {
     ident -> (ident.name),
+    def,
     infer_types,
     args
 });

src/librustc_resolve/build_reduced_graph.rs

@@ -141,7 +141,7 @@ impl<'a, 'cl> Resolver<'a, 'cl> {
         let prefix_iter = || parent_prefix.iter().cloned()
             .chain(use_tree.prefix.segments.iter().map(|seg| seg.ident));
         let prefix_start = prefix_iter().next();
-        let starts_with_non_keyword = prefix_start.map_or(false, |ident| {
+        let starts_with_non_keyword = prefix_start.map_or(false, |(ident, _)| {
             !ident.is_path_segment_keyword()
         });
 
@@ -202,13 +202,13 @@ impl<'a, 'cl> Resolver<'a, 'cl> {
             let source = prefix_start.unwrap();
 
             // Helper closure to emit a canary with the given base path.
-            let emit = |this: &mut Self, base: Option<Ident>| {
+            let emit = |this: &mut Self, base: Option<(Ident, Option<NodeId>)>| {
                 let subclass = SingleImport {
                     target: Ident {
                         name: keywords::Underscore.name().gensymed(),
-                        span: source.span,
+                        span: source.0.span,
                     },
-                    source,
+                    source: source.0,
                     result: PerNS {
                         type_ns: Cell::new(Err(Undetermined)),
                         value_ns: Cell::new(Err(Undetermined)),
@@ -219,7 +219,7 @@ impl<'a, 'cl> Resolver<'a, 'cl> {
                 this.add_import_directive(
                     base.into_iter().collect(),
                     subclass.clone(),
-                    source.span,
+                    source.0.span,
                     id,
                     root_use_tree.span,
                     root_id,
@@ -230,15 +230,15 @@ impl<'a, 'cl> Resolver<'a, 'cl> {
             };
 
             // A single simple `self::x` canary.
-            emit(self, Some(Ident {
+            emit(self, Some((Ident {
                 name: keywords::SelfValue.name(),
-                span: source.span,
+                span: source.0.span,
-            }));
+            }, source.1)));
 
             // One special unprefixed canary per block scope around
             // the import, to detect items unreachable by `self::x`.
             let orig_current_module = self.current_module;
-            let mut span = source.span.modern();
+            let mut span = source.0.span.modern();
             loop {
                 match self.current_module.kind {
                     ModuleKind::Block(..) => emit(self, None),
@@ -265,10 +265,10 @@ impl<'a, 'cl> Resolver<'a, 'cl> {
 
                 if nested {
                     // Correctly handle `self`
-                    if source.name == keywords::SelfValue.name() {
+                    if source.0.name == keywords::SelfValue.name() {
                         type_ns_only = true;
 
-                        let empty_prefix = module_path.last().map_or(true, |ident| {
+                        let empty_prefix = module_path.last().map_or(true, |(ident, _)| {
                             ident.name == keywords::CrateRoot.name()
                         });
                         if empty_prefix {
@@ -284,20 +284,20 @@ impl<'a, 'cl> Resolver<'a, 'cl> {
                         // Replace `use foo::self;` with `use foo;`
                         source = module_path.pop().unwrap();
                         if rename.is_none() {
-                            ident = source;
+                            ident = source.0;
                         }
                     }
                 } else {
                     // Disallow `self`
-                    if source.name == keywords::SelfValue.name() {
+                    if source.0.name == keywords::SelfValue.name() {
                         resolve_error(self,
                                       use_tree.span,
                                       ResolutionError::SelfImportsOnlyAllowedWithin);
                     }
 
                     // Disallow `use $crate;`
-                    if source.name == keywords::DollarCrate.name() && module_path.is_empty() {
+                    if source.0.name == keywords::DollarCrate.name() && module_path.is_empty() {
-                        let crate_root = self.resolve_crate_root(source);
+                        let crate_root = self.resolve_crate_root(source.0);
                         let crate_name = match crate_root.kind {
                             ModuleKind::Def(_, name) => name,
                             ModuleKind::Block(..) => unreachable!(),
@@ -307,11 +307,11 @@ impl<'a, 'cl> Resolver<'a, 'cl> {
                         // while the current crate doesn't have a valid `crate_name`.
                         if crate_name != keywords::Invalid.name() {
                             // `crate_name` should not be interpreted as relative.
-                            module_path.push(Ident {
+                            module_path.push((Ident {
                                 name: keywords::CrateRoot.name(),
-                                span: source.span,
+                                span: source.0.span,
-                            });
+                            }, Some(self.session.next_node_id())));
-                            source.name = crate_name;
+                            source.0.name = crate_name;
                         }
                         if rename.is_none() {
                             ident.name = crate_name;
@@ -332,7 +332,7 @@ impl<'a, 'cl> Resolver<'a, 'cl> {
 
                 let subclass = SingleImport {
                     target: ident,
-                    source,
+                    source: source.0,
                     result: PerNS {
                         type_ns: Cell::new(Err(Undetermined)),
                         value_ns: Cell::new(Err(Undetermined)),
@@ -393,6 +393,17 @@ impl<'a, 'cl> Resolver<'a, 'cl> {
                 }
 
                 for &(ref tree, id) in items {
+                    let prefix = ast::Path {
+                        segments: module_path.iter()
+                            .map(|ident| {
+                                let mut seg = ast::PathSegment::from_ident(ident.0);
+                                seg.id = self.session.next_node_id();
+                                seg
+                            })
+                            .collect(),
+                        span: path.span,
+                    };
+
                     self.build_reduced_graph_for_use_tree(
                         root_use_tree,
                         root_id,

src/librustc_resolve/lib.rs

@@ -1534,8 +1534,13 @@ impl<'a, 'b: 'a, 'cl: 'b> ty::DefIdTree for &'a Resolver<'b, 'cl> {
 /// This interface is used through the AST→HIR step, to embed full paths into the HIR. After that
 /// the resolver is no longer needed as all the relevant information is inline.
 impl<'a, 'cl> hir::lowering::Resolver for Resolver<'a, 'cl> {
-    fn resolve_hir_path(&mut self, path: &mut hir::Path, is_value: bool) {
+    fn resolve_hir_path(
-        self.resolve_hir_path_cb(path, is_value,
+        &mut self,
+        path: &ast::Path,
+        args: Option<P<hir::GenericArgs>>,
+        is_value: bool,
+    ) -> hir::Path {
+        self.resolve_hir_path_cb(path, args, is_value,
                                  |resolver, span, error| resolve_error(resolver, span, error))
     }
 
@@ -1547,30 +1552,20 @@ impl<'a, 'cl> hir::lowering::Resolver for Resolver<'a, 'cl> {
         args: Option<P<hir::GenericArgs>>,
         is_value: bool
     ) -> hir::Path {
-        let mut segments = iter::once(keywords::CrateRoot.ident())
+        let segments = iter::once(keywords::CrateRoot.ident())
             .chain(
                 crate_root.into_iter()
                     .chain(components.iter().cloned())
                     .map(Ident::from_str)
-            ).map(hir::PathSegment::from_ident).collect::<Vec<_>>();
+            ).map(|i| self.new_ast_path_segment(i)).collect::<Vec<_>>();
 
-        if let Some(args) = args {
-            let ident = segments.last().unwrap().ident;
-            *segments.last_mut().unwrap() = hir::PathSegment {
-                ident,
-                args: Some(args),
-                infer_types: true,
-            };
-        }
 
-        let mut path = hir::Path {
+        let path = ast::Path {
             span,
-            def: Def::Err,
+            segments,
-            segments: segments.into(),
         };
 
-        self.resolve_hir_path(&mut path, is_value);
+        self.resolve_hir_path(&path, args, is_value)
-        path
     }
 
     fn get_resolution(&mut self, id: NodeId) -> Option<PathResolution> {
@@ -1596,23 +1591,27 @@ impl<'a, 'crateloader> Resolver<'a, 'crateloader> {
         use std::iter;
         let mut errored = false;
 
-        let mut path = if path_str.starts_with("::") {
+        let path = if path_str.starts_with("::") {
-            hir::Path {
+            ast::Path {
                 span,
-                def: Def::Err,
+                segments: iter::once(keywords::CrateRoot.ident())
-                segments: iter::once(keywords::CrateRoot.ident()).chain({
+                    .chain({
-                    path_str.split("::").skip(1).map(Ident::from_str)
+                        path_str.split("::").skip(1).map(Ident::from_str)
-                }).map(hir::PathSegment::from_ident).collect(),
+                    })
+                    .map(|i| self.new_ast_path_segment(i))
+                    .collect(),
             }
         } else {
-            hir::Path {
+            ast::Path {
                 span,
-                def: Def::Err,
+                segments: path_str
-                segments: path_str.split("::").map(Ident::from_str)
+                    .split("::")
-                                  .map(hir::PathSegment::from_ident).collect(),
+                    .map(Ident::from_str)
+                    .map(|i| self.new_ast_path_segment(i))
+                    .collect(),
             }
         };
-        self.resolve_hir_path_cb(&mut path, is_value, |_, _, _| errored = true);
+        let path = self.resolve_hir_path_cb(&path, None, is_value, |_, _, _| errored = true);
         if errored || path.def == Def::Err {
             Err(())
         } else {
@@ -1621,16 +1620,23 @@ impl<'a, 'crateloader> Resolver<'a, 'crateloader> {
     }
 
     /// resolve_hir_path, but takes a callback in case there was an error
-    fn resolve_hir_path_cb<F>(&mut self, path: &mut hir::Path, is_value: bool, error_callback: F)
+    fn resolve_hir_path_cb<F>(
+        &mut self,
+        path: &ast::Path,
+        args: Option<P<hir::GenericArgs>>,
+        is_value: bool,
+        error_callback: F,
+    ) -> hir::Path
         where F: for<'c, 'b> FnOnce(&'c mut Resolver, Span, ResolutionError<'b>)
     {
         let namespace = if is_value { ValueNS } else { TypeNS };
-        let hir::Path { ref segments, span, ref mut def } = *path;
+        let span = path.span;
-        let path: Vec<_> = segments.iter().map(|seg| seg.ident).collect();
+        let segments = &path.segments;
+        let path: Vec<_> = segments.iter().map(|seg| (seg.ident, Some(seg.id))).collect();
         // FIXME (Manishearth): Intra doc links won't get warned of epoch changes
-        match self.resolve_path(None, &path, Some(namespace), true, span, CrateLint::No) {
+        let def = match self.resolve_path(None, &path, Some(namespace), true, span, CrateLint::No) {
             PathResult::Module(ModuleOrUniformRoot::Module(module)) =>
-                *def = module.def().unwrap(),
+                module.def().unwrap(),
             PathResult::NonModule(path_res) if path_res.unresolved_segments() == 0 =>
                 *def = path_res.base_def(),
             PathResult::NonModule(..) =>
@@ -1648,9 +1654,28 @@ impl<'a, 'crateloader> Resolver<'a, 'crateloader> {
             PathResult::Indeterminate => unreachable!(),
             PathResult::Failed(span, msg, _) => {
                 error_callback(self, span, ResolutionError::FailedToResolve(&msg));
+                Def::Err
             }
+        };
+
+        let mut segments: Vec<_> = segments.iter().map(|seg| {
+            let mut hir_seg = hir::PathSegment::from_ident(seg.ident);
+            hir_seg.def = Some(self.def_map.get(&seg.id).map_or(Def::Err, |p| p.base_def()));
+            hir_seg
+        }).collect();
+        segments.last_mut().unwrap().args = args;
+        hir::Path {
+            span,
+            def,
+            segments: segments.into(),
         }
     }
+
+    fn new_ast_path_segment(&self, ident: Ident) -> ast::PathSegment {
+        let mut seg = ast::PathSegment::from_ident(ident);
+        seg.id = self.session.next_node_id();
+        seg
+    }
 }
 
 impl<'a, 'crateloader: 'a> Resolver<'a, 'crateloader> {
@@ -2458,7 +2483,7 @@ impl<'a, 'crateloader: 'a> Resolver<'a, 'crateloader> {
         let mut new_id = None;
         if let Some(trait_ref) = opt_trait_ref {
             let path: Vec<_> = trait_ref.path.segments.iter()
-                .map(|seg| seg.ident)
+                .map(|seg| (seg.ident, Some(seg.id)))
                 .collect();
             let def = self.smart_resolve_path_fragment(
                 trait_ref.ref_id,
@@ -2956,7 +2981,7 @@ impl<'a, 'crateloader: 'a> Resolver<'a, 'crateloader> {
         crate_lint: CrateLint
     ) -> PathResolution {
         let segments = &path.segments.iter()
-            .map(|seg| seg.ident)
+            .map(|seg| (seg.ident, Some(seg.id)))
             .collect::<Vec<_>>();
         self.smart_resolve_path_fragment(id, qself, segments, path.span, source, crate_lint)
     }
@@ -2964,12 +2989,12 @@ impl<'a, 'crateloader: 'a> Resolver<'a, 'crateloader> {
     fn smart_resolve_path_fragment(&mut self,
                                    id: NodeId,
                                    qself: Option<&QSelf>,
-                                   path: &[Ident],
+                                   path: &[(Ident, Option<NodeId>)],
                                    span: Span,
                                    source: PathSource,
                                    crate_lint: CrateLint)
                                    -> PathResolution {
-        let ident_span = path.last().map_or(span, |ident| ident.span);
+        let ident_span = path.last().map_or(span, |ident| ident.0.span);
         let ns = source.namespace();
         let is_expected = &|def| source.is_expected(def);
         let is_enum_variant = &|def| if let Def::Variant(..) = def { true } else { false };
@@ -2979,17 +3004,17 @@ impl<'a, 'crateloader: 'a> Resolver<'a, 'crateloader> {
             // Make the base error.
             let expected = source.descr_expected();
             let path_str = names_to_string(path);
-            let item_str = path.last().unwrap();
+            let item_str = path.last().unwrap().0;
             let code = source.error_code(def.is_some());
             let (base_msg, fallback_label, base_span) = if let Some(def) = def {
                 (format!("expected {}, found {} `{}`", expected, def.kind_name(), path_str),
                  format!("not a {}", expected),
                  span)
             } else {
-                let item_span = path.last().unwrap().span;
+                let item_span = path.last().unwrap().0.span;
                 let (mod_prefix, mod_str) = if path.len() == 1 {
                     (String::new(), "this scope".to_string())
-                } else if path.len() == 2 && path[0].name == keywords::CrateRoot.name() {
+                } else if path.len() == 2 && path[0].0.name == keywords::CrateRoot.name() {
                     (String::new(), "the crate root".to_string())
                 } else {
                     let mod_path = &path[..path.len() - 1];
@@ -2999,7 +3024,7 @@ impl<'a, 'crateloader: 'a> Resolver<'a, 'crateloader> {
                             module.def(),
                         _ => None,
                     }.map_or(String::new(), |def| format!("{} ", def.kind_name()));
-                    (mod_prefix, format!("`{}`", names_to_string(mod_path)))
+                    (mod_prefix, format!("`{}`", names_and_ids_to_string(mod_path)))
                 };
                 (format!("cannot find {} `{}` in {}{}", expected, item_str, mod_prefix, mod_str),
                  format!("not found in {}", mod_str),
@@ -3045,7 +3070,7 @@ impl<'a, 'crateloader: 'a> Resolver<'a, 'crateloader> {
             }
 
             // Try to lookup the name in more relaxed fashion for better error reporting.
-            let ident = *path.last().unwrap();
+            let ident = path.last().unwrap().0;
             let candidates = this.lookup_import_candidates(ident.name, ns, is_expected);
             if candidates.is_empty() && is_expected(Def::Enum(DefId::local(CRATE_DEF_INDEX))) {
                 let enum_candidates =
@@ -3072,7 +3097,7 @@ impl<'a, 'crateloader: 'a> Resolver<'a, 'crateloader> {
             }
             if path.len() == 1 && this.self_type_is_available(span) {
                 if let Some(candidate) = this.lookup_assoc_candidate(ident, ns, is_expected) {
-                    let self_is_available = this.self_value_is_available(path[0].span, span);
+                    let self_is_available = this.self_value_is_available(path[0].0.span, span);
                     match candidate {
                         AssocSuggestion::Field => {
                             err.span_suggestion_with_applicability(
@@ -3307,7 +3332,7 @@ impl<'a, 'crateloader: 'a> Resolver<'a, 'crateloader> {
                 // or `<T>::A::B`. If `B` should be resolved in value namespace then
                 // it needs to be added to the trait map.
                 if ns == ValueNS {
-                    let item_name = *path.last().unwrap();
+                    let item_name = path.last().unwrap().0;
                     let traits = self.get_traits_containing_item(item_name, ns);
                     self.trait_map.insert(id, traits);
                 }
@@ -3377,7 +3402,7 @@ impl<'a, 'crateloader: 'a> Resolver<'a, 'crateloader> {
     fn resolve_qpath_anywhere(&mut self,
                               id: NodeId,
                               qself: Option<&QSelf>,
-                              path: &[Ident],
+                              path: &[(Ident, Option<NodeId>)],
                               primary_ns: Namespace,
                               span: Span,
                               defer_to_typeck: bool,
@@ -3399,10 +3424,10 @@ impl<'a, 'crateloader: 'a> Resolver<'a, 'crateloader> {
             }
         }
         if primary_ns != MacroNS &&
-           (self.macro_names.contains(&path[0].modern()) ||
+           (self.macro_names.contains(&path[0].0.modern()) ||
-            self.builtin_macros.get(&path[0].name).cloned()
+            self.builtin_macros.get(&path[0].0.name).cloned()
                                .and_then(NameBinding::macro_kind) == Some(MacroKind::Bang) ||
-            self.macro_use_prelude.get(&path[0].name).cloned()
+            self.macro_use_prelude.get(&path[0].0.name).cloned()
                                   .and_then(NameBinding::macro_kind) == Some(MacroKind::Bang)) {
             // Return some dummy definition, it's enough for error reporting.
             return Some(
@@ -3416,7 +3441,7 @@ impl<'a, 'crateloader: 'a> Resolver<'a, 'crateloader> {
     fn resolve_qpath(&mut self,
                      id: NodeId,
                      qself: Option<&QSelf>,
-                     path: &[Ident],
+                     path: &[(Ident, Option<NodeId>)],
                      ns: Namespace,
                      span: Span,
                      global_by_default: bool,
@@ -3506,8 +3531,8 @@ impl<'a, 'crateloader: 'a> Resolver<'a, 'crateloader> {
             PathResult::Failed(..)
                     if (ns == TypeNS || path.len() > 1) &&
                        self.primitive_type_table.primitive_types
-                           .contains_key(&path[0].name) => {
+                           .contains_key(&path[0].0.name) => {
-                let prim = self.primitive_type_table.primitive_types[&path[0].name];
+                let prim = self.primitive_type_table.primitive_types[&path[0].0.name];
                 PathResolution::with_unresolved_segments(Def::PrimTy(prim), path.len() - 1)
             }
             PathResult::Module(ModuleOrUniformRoot::Module(module)) =>
@@ -3522,8 +3547,8 @@ impl<'a, 'crateloader: 'a> Resolver<'a, 'crateloader> {
         };
 
         if path.len() > 1 && !global_by_default && result.base_def() != Def::Err &&
-           path[0].name != keywords::CrateRoot.name() &&
+           path[0].0.name != keywords::CrateRoot.name() &&
-           path[0].name != keywords::DollarCrate.name() {
+           path[0].0.name != keywords::DollarCrate.name() {
             let unqualified_result = {
                 match self.resolve_path(
                     None,
@@ -3551,7 +3576,7 @@ impl<'a, 'crateloader: 'a> Resolver<'a, 'crateloader> {
     fn resolve_path(
         &mut self,
         base_module: Option<ModuleOrUniformRoot<'a>>,
-        path: &[Ident],
+        path: &[(Ident, Option<NodeId>)],
         opt_ns: Option<Namespace>, // `None` indicates a module path
         record_used: bool,
         path_span: Span,
@@ -3587,7 +3612,7 @@ impl<'a, 'crateloader: 'a> Resolver<'a, 'crateloader> {
             crate_lint,
         );
 
-        for (i, &ident) in path.iter().enumerate() {
+        for (i, &(ident, id)) in path.iter().enumerate() {
             debug!("resolve_path ident {} {:?}", i, ident);
             let is_last = i == path.len() - 1;
             let ns = if is_last { opt_ns.unwrap_or(TypeNS) } else { TypeNS };
@@ -3648,7 +3673,7 @@ impl<'a, 'crateloader: 'a> Resolver<'a, 'crateloader> {
                 } else {
                     format!("`{}`", name)
                 };
-                let msg = if i == 1 && path[0].name == keywords::CrateRoot.name() {
+                let msg = if i == 1 && path[0].0.name == keywords::CrateRoot.name() {
                     format!("global paths cannot start with {}", name_str)
                 } else {
                     format!("{} in paths can only be used in start position", name_str)
@@ -3688,6 +3713,12 @@ impl<'a, 'crateloader: 'a> Resolver<'a, 'crateloader> {
                     let maybe_assoc = opt_ns != Some(MacroNS) && PathSource::Type.is_expected(def);
                     if let Some(next_module) = binding.module() {
                         module = Some(ModuleOrUniformRoot::Module(next_module));
+                        if !is_last && record_used {
+                            if let Some(id) = id {
+                                assert!(id != ast::DUMMY_NODE_ID, "Trying to resolve dummy id");
+                                self.record_def(id, PathResolution::new(def));
+                            }
+                        }
                     } else if def == Def::ToolMod && i + 1 != path.len() {
                         let def = Def::NonMacroAttr(NonMacroAttrKind::Tool);
                         return PathResult::NonModule(PathResolution::new(def));
@@ -3737,7 +3768,7 @@ impl<'a, 'crateloader: 'a> Resolver<'a, 'crateloader> {
                     } else if i == 0 {
                         format!("Use of undeclared type or module `{}`", ident)
                     } else {
-                        format!("Could not find `{}` in `{}`", ident, path[i - 1])
+                        format!("Could not find `{}` in `{}`", ident, path[i - 1].0)
                     };
                     return PathResult::Failed(ident.span, msg, is_last);
                 }
@@ -3755,7 +3786,7 @@ impl<'a, 'crateloader: 'a> Resolver<'a, 'crateloader> {
     fn lint_if_path_starts_with_module(
         &self,
         crate_lint: CrateLint,
-        path: &[Ident],
+        path: &[(Ident, Option<NodeId>)],
         path_span: Span,
         second_binding: Option<&NameBinding>,
     ) {
@@ -3772,7 +3803,7 @@ impl<'a, 'crateloader: 'a> Resolver<'a, 'crateloader> {
         };
 
         let first_name = match path.get(0) {
-            Some(ident) => ident.name,
+            Some(ident) => ident.0.name,
             None => return,
         };
 
@@ -3784,7 +3815,7 @@ impl<'a, 'crateloader: 'a> Resolver<'a, 'crateloader> {
 
         match path.get(1) {
             // If this import looks like `crate::...` it's already good
-            Some(ident) if ident.name == keywords::Crate.name() => return,
+            Some((ident, _)) if ident.name == keywords::Crate.name() => return,
             // Otherwise go below to see if it's an extern crate
             Some(_) => {}
             // If the path has length one (and it's `CrateRoot` most likely)
@@ -3977,7 +4008,7 @@ impl<'a, 'crateloader: 'a> Resolver<'a, 'crateloader> {
     }
 
     fn lookup_typo_candidate<FilterFn>(&mut self,
-                                       path: &[Ident],
+                                       path: &[(Ident, Option<NodeId>)],
                                        ns: Namespace,
                                        filter_fn: FilterFn,
                                        span: Span)
@@ -4041,7 +4072,7 @@ impl<'a, 'crateloader: 'a> Resolver<'a, 'crateloader> {
             }
         }
 
-        let name = path[path.len() - 1].name;
+        let name = path[path.len() - 1].0.name;
         // Make sure error reporting is deterministic.
         names.sort_by_cached_key(|name| name.as_str());
         match find_best_match_for_name(names.iter(), &name.as_str(), None) {
@@ -4558,7 +4589,7 @@ impl<'a, 'crateloader: 'a> Resolver<'a, 'crateloader> {
             ast::VisibilityKind::Restricted { ref path, id, .. } => {
                 // Visibilities are resolved as global by default, add starting root segment.
                 let segments = path.make_root().iter().chain(path.segments.iter())
-                    .map(|seg| seg.ident)
+                    .map(|seg| (seg.ident, Some(seg.id)))
                     .collect::<Vec<_>>();
                 let def = self.smart_resolve_path_fragment(
                     id,
@@ -4851,12 +4882,12 @@ impl<'a, 'crateloader: 'a> Resolver<'a, 'crateloader> {
     }
 }
 
-fn is_self_type(path: &[Ident], namespace: Namespace) -> bool {
+fn is_self_type(path: &[(Ident, Option<NodeId>)], namespace: Namespace) -> bool {
-    namespace == TypeNS && path.len() == 1 && path[0].name == keywords::SelfType.name()
+    namespace == TypeNS && path.len() == 1 && path[0].0.name == keywords::SelfType.name()
 }
 
-fn is_self_value(path: &[Ident], namespace: Namespace) -> bool {
+fn is_self_value(path: &[(Ident, Option<NodeId>)], namespace: Namespace) -> bool {
-    namespace == ValueNS && path.len() == 1 && path[0].name == keywords::SelfValue.name()
+    namespace == ValueNS && path.len() == 1 && path[0].0.name == keywords::SelfValue.name()
 }
 
 fn names_to_string(idents: &[Ident]) -> String {
@@ -4872,6 +4903,12 @@ fn names_to_string(idents: &[Ident]) -> String {
     result
 }
 
+fn names_and_ids_to_string(segments: &[(Ident, Option<NodeId>)]) -> String {
+    names_to_string(&segments.iter()
+                        .map(|seg| seg.0)
+                        .collect::<Vec<_>>())
+}
+
 fn path_names_to_string(path: &Path) -> String {
     names_to_string(&path.segments.iter()
                         .map(|seg| seg.ident)

src/librustc_resolve/macros.rs

@@ -462,13 +462,13 @@ impl<'a, 'cl> Resolver<'a, 'cl> {
         force: bool,
     ) -> Result<Def, Determinacy> {
         let ast::Path { ref segments, span } = *path;
-        let mut path: Vec<_> = segments.iter().map(|seg| seg.ident).collect();
+        let mut path: Vec<_> = segments.iter().map(|seg| (seg.ident, Some(seg.id))).collect();
 
         // Possibly apply the macro helper hack
         if kind == MacroKind::Bang && path.len() == 1 &&
-           path[0].span.ctxt().outer().expn_info().map_or(false, |info| info.local_inner_macros) {
+           path[0].0.span.ctxt().outer().expn_info().map_or(false, |info| info.local_inner_macros) {
-            let root = Ident::new(keywords::DollarCrate.name(), path[0].span);
+            let root = Ident::new(keywords::DollarCrate.name(), path[0].0.span);
-            path.insert(0, root);
+            path.insert(0, (root, None));
         }
 
         if path.len() > 1 {
@@ -496,12 +496,16 @@ impl<'a, 'cl> Resolver<'a, 'cl> {
             };
 
             parent_scope.module.macro_resolutions.borrow_mut()
-                .push((path.into_boxed_slice(), span));
+                .push((path
+                    .iter()
+                    .map(|(ident, _)| *ident)
+                    .collect::<Vec<Ident>>()
+                    .into_boxed_slice(), span));
 
             def
         } else {
             let binding = self.early_resolve_ident_in_lexical_scope(
-                path[0], MacroNS, Some(kind), parent_scope, false, force, span
+                path[0].0, MacroNS, Some(kind), parent_scope, false, force, span
             );
             match binding {
                 Ok(..) => {}
@@ -510,7 +514,7 @@ impl<'a, 'cl> Resolver<'a, 'cl> {
             }
 
             parent_scope.module.legacy_macro_resolutions.borrow_mut()
-                .push((path[0], kind, parent_scope.clone(), binding.ok()));
+                .push((path[0].0, kind, parent_scope.clone(), binding.ok()));
 
             binding.map(|binding| binding.def_ignoring_ambiguity())
         }
@@ -846,6 +850,10 @@ impl<'a, 'cl> Resolver<'a, 'cl> {
     pub fn finalize_current_module_macro_resolutions(&mut self) {
         let module = self.current_module;
         for &(ref path, span) in module.macro_resolutions.borrow().iter() {
+            let path = path
+                .iter()
+                .map(|ident| (*ident, None))
+                .collect::<Vec<(Ident, Option<ast::NodeId>)>>();
             match self.resolve_path(None, &path, Some(MacroNS), true, span, CrateLint::No) {
                 PathResult::NonModule(_) => {},
                 PathResult::Failed(span, msg, _) => {
@@ -938,7 +946,7 @@ impl<'a, 'cl> Resolver<'a, 'cl> {
                 }
             };
             let ident = Ident::new(Symbol::intern(name), span);
-            self.lookup_typo_candidate(&[ident], MacroNS, is_macro, span)
+            self.lookup_typo_candidate(&[(ident, None)], MacroNS, is_macro, span)
         });
 
         if let Some(suggestion) = suggestion {

src/librustc_resolve/resolve_imports.rs

@@ -14,7 +14,7 @@ use {AmbiguityError, CrateLint, Module, ModuleOrUniformRoot, PerNS};
 use Namespace::{self, TypeNS, MacroNS};
 use {NameBinding, NameBindingKind, ToNameBinding, PathResult, PrivacyError};
 use Resolver;
-use {names_to_string, module_to_string};
+use {names_to_string, names_and_ids_to_string, module_to_string};
 use {resolve_error, ResolutionError};
 
 use rustc_data_structures::ptr_key::PtrKey;
@@ -89,7 +89,7 @@ pub struct ImportDirective<'a> {
     pub root_span: Span,
 
     pub parent: Module<'a>,
-    pub module_path: Vec<Ident>,
+    pub module_path: Vec<(Ident, Option<NodeId>)>,
     /// The resolution of `module_path`.
     pub imported_module: Cell<Option<ModuleOrUniformRoot<'a>>>,
     pub subclass: ImportDirectiveSubclass<'a>,
@@ -393,7 +393,7 @@ impl<'a, 'crateloader> Resolver<'a, 'crateloader> {
 
     // Add an import directive to the current module.
     pub fn add_import_directive(&mut self,
-                                module_path: Vec<Ident>,
+                                module_path: Vec<(Ident, Option<NodeId>)>,
                                 subclass: ImportDirectiveSubclass<'a>,
                                 span: Span,
                                 id: NodeId,
@@ -679,7 +679,7 @@ impl<'a, 'b:'a, 'c: 'b> ImportResolver<'a, 'b, 'c> {
 
                 let has_explicit_self =
                     !import.module_path.is_empty() &&
-                    import.module_path[0].name == keywords::SelfValue.name();
+                    import.module_path[0].0.name == keywords::SelfValue.name();
 
                 self.per_ns(|_, ns| {
                     if let Some(result) = result[ns].get().ok() {
@@ -728,9 +728,11 @@ impl<'a, 'b:'a, 'c: 'b> ImportResolver<'a, 'b, 'c> {
                     self.throw_unresolved_import_error(empty_vec, None);
                 }
                 if !seen_spans.contains(&span) {
-                    let path = import_path_to_string(&import.module_path[..],
+                    let path = import_path_to_string(
-                                                     &import.subclass,
+                        &import.module_path.iter().map(|(ident, _)| *ident).collect::<Vec<_>>(),
-                                                     span);
+                        &import.subclass,
+                        span,
+                    );
                     error_vec.push((span, path, err));
                     seen_spans.insert(span);
                     prev_root_id = import.root_id;
@@ -851,7 +853,7 @@ impl<'a, 'b:'a, 'c: 'b> ImportResolver<'a, 'b, 'c> {
     /// If successful, the resolved bindings are written into the module.
     fn resolve_import(&mut self, directive: &'b ImportDirective<'b>) -> bool {
         debug!("(resolving import for module) resolving import `{}::...` in `{}`",
-               names_to_string(&directive.module_path[..]),
+               names_and_ids_to_string(&directive.module_path[..]),
                module_to_string(self.current_module).unwrap_or_else(|| "???".to_string()));
 
         self.current_module = directive.parent;
@@ -982,7 +984,7 @@ impl<'a, 'b:'a, 'c: 'b> ImportResolver<'a, 'b, 'c> {
                     // HACK(eddyb) `lint_if_path_starts_with_module` needs at least
                     // 2 segments, so the `resolve_path` above won't trigger it.
                     let mut full_path = module_path.clone();
-                    full_path.push(keywords::Invalid.ident());
+                    full_path.push((keywords::Invalid.ident(), None));
                     self.lint_if_path_starts_with_module(
                         directive.crate_lint(),
                         &full_path,
@@ -1146,7 +1148,7 @@ impl<'a, 'b:'a, 'c: 'b> ImportResolver<'a, 'b, 'c> {
             // HACK(eddyb) `lint_if_path_starts_with_module` needs at least
             // 2 segments, so the `resolve_path` above won't trigger it.
             let mut full_path = module_path.clone();
-            full_path.push(ident);
+            full_path.push((ident, None));
             self.per_ns(|this, ns| {
                 if let Ok(binding) = result[ns].get() {
                     this.lint_if_path_starts_with_module(
@@ -1288,7 +1290,7 @@ impl<'a, 'b:'a, 'c: 'b> ImportResolver<'a, 'b, 'c> {
                         let resolutions = imported_module.parent.expect("parent should exist")
                             .resolutions.borrow();
                         let enum_path_segment_index = directive.module_path.len() - 1;
-                        let enum_ident = directive.module_path[enum_path_segment_index];
+                        let enum_ident = directive.module_path[enum_path_segment_index].0;
 
                         let enum_resolution = resolutions.get(&(enum_ident, TypeNS))
                             .expect("resolution should exist");
@@ -1311,6 +1313,7 @@ impl<'a, 'b:'a, 'c: 'b> ImportResolver<'a, 'b, 'c> {
                                                        "consider making the enum public",
                                                        suggestion);
                         err.emit();
+                    }
                 }
             }
         }

src/libsyntax/ast.rs

@@ -147,7 +147,7 @@ impl PathSegment {
     pub fn crate_root(span: Span) -> Self {
         PathSegment {
             ident: Ident::new(keywords::CrateRoot.name(), span),
-            id: CRATE_NODE_ID,
+            id: DUMMY_NODE_ID,
             args: None,
         }
     }