resolve: Move some code around

Avoid using dummy spans for some external items with available spans

src/librustc_resolve/build_reduced_graph.rs

@@ -865,6 +865,7 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
         // This is only a guess, two equivalent idents may incorrectly get different gensyms here.
         let ident = ident.gensym_if_underscore();
         let expansion = ExpnId::root(); // FIXME(jseyfried) intercrate hygiene
+        // Record primary definitions.
         match res {
             Res::Def(kind @ DefKind::Mod, def_id)
             | Res::Def(kind @ DefKind::Enum, def_id)
@@ -874,53 +875,52 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
                                              def_id,
                                              expansion,
                                              span);
-                self.r.define(parent, ident, TypeNS, (module, vis, DUMMY_SP, expansion));
+                self.r.define(parent, ident, TypeNS, (module, vis, span, expansion));
             }
-            Res::Def(DefKind::Variant, _)
+            Res::Def(DefKind::Struct, _)
+            | Res::Def(DefKind::Union, _)
+            | Res::Def(DefKind::Variant, _)
             | Res::Def(DefKind::TyAlias, _)
             | Res::Def(DefKind::ForeignTy, _)
             | Res::Def(DefKind::OpaqueTy, _)
             | Res::Def(DefKind::TraitAlias, _)
             | Res::Def(DefKind::AssocTy, _)
             | Res::Def(DefKind::AssocOpaqueTy, _)
             | Res::PrimTy(..)
-            | Res::ToolMod => {
-                self.r.define(parent, ident, TypeNS, (res, vis, DUMMY_SP, expansion));
-            }
+            | Res::ToolMod =>
+                self.r.define(parent, ident, TypeNS, (res, vis, span, expansion)),
             Res::Def(DefKind::Fn, _)
+            | Res::Def(DefKind::Method, _)
             | Res::Def(DefKind::Static, _)
             | Res::Def(DefKind::Const, _)
             | Res::Def(DefKind::AssocConst, _)
-            | Res::Def(DefKind::Ctor(CtorOf::Variant, ..), _) => {
-                self.r.define(parent, ident, ValueNS, (res, vis, DUMMY_SP, expansion));
-            }
-            Res::Def(DefKind::Ctor(CtorOf::Struct, ..), def_id) => {
-                self.r.define(parent, ident, ValueNS, (res, vis, DUMMY_SP, expansion));
-
-                if let Some(struct_def_id) =
-                        self.r.cstore.def_key(def_id).parent
-                            .map(|index| DefId { krate: def_id.krate, index: index }) {
-                    self.r.struct_constructors.insert(struct_def_id, (res, vis));
-                }
+            | Res::Def(DefKind::Ctor(..), _) =>
+                self.r.define(parent, ident, ValueNS, (res, vis, span, expansion)),
+            Res::Def(DefKind::Macro(..), _)
+            | Res::NonMacroAttr(..) =>
+                self.r.define(parent, ident, MacroNS, (res, vis, span, expansion)),
+            Res::Def(DefKind::TyParam, _) | Res::Def(DefKind::ConstParam, _)
+            | Res::Local(..) | Res::SelfTy(..) | Res::SelfCtor(..) | Res::Err =>
+                bug!("unexpected resolution: {:?}", res)
+        }
+        // Record some extra data for better diagnostics.
+        match res {
+            Res::Def(DefKind::Struct, def_id) | Res::Def(DefKind::Union, def_id) => {
+                let field_names = self.r.cstore.struct_field_names_untracked(def_id);
+                self.insert_field_names(def_id, field_names);
             }
             Res::Def(DefKind::Method, def_id) => {
-                self.r.define(parent, ident, ValueNS, (res, vis, DUMMY_SP, expansion));
-
                 if self.r.cstore.associated_item_cloned_untracked(def_id).method_has_self_argument {
                     self.r.has_self.insert(def_id);
                 }
             }
-            Res::Def(DefKind::Struct, def_id) | Res::Def(DefKind::Union, def_id) => {
-                self.r.define(parent, ident, TypeNS, (res, vis, DUMMY_SP, expansion));
-
-                // Record field names for error reporting.
-                let field_names = self.r.cstore.struct_field_names_untracked(def_id);
-                self.insert_field_names(def_id, field_names);
-            }
-            Res::Def(DefKind::Macro(..), _) | Res::NonMacroAttr(..) => {
-                self.r.define(parent, ident, MacroNS, (res, vis, DUMMY_SP, expansion));
+            Res::Def(DefKind::Ctor(CtorOf::Struct, ..), def_id) => {
+                let parent = self.r.cstore.def_key(def_id).parent;
+                if let Some(struct_def_id) = parent.map(|index| DefId { index, ..def_id }) {
+                    self.r.struct_constructors.insert(struct_def_id, (res, vis));
+                }
             }
-            _ => bug!("unexpected resolution: {:?}", res)
+            _ => {}
         }
     }
 
@@ -981,7 +981,7 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
         if let Some(span) = import_all {
             let directive = macro_use_directive(self, span);
             self.r.potentially_unused_imports.push(directive);
-            module.for_each_child(&mut self.r, |this, ident, ns, binding| if ns == MacroNS {
+            self.r.for_each_child(module, |this, ident, ns, binding| if ns == MacroNS {
                 let imported_binding = this.import(binding, directive);
                 this.legacy_import_macro(ident.name, imported_binding, span, allow_shadowing);
             });

src/librustc_resolve/diagnostics.rs

@@ -73,23 +73,23 @@ crate fn add_typo_suggestion(
     false
 }
 
-crate fn add_module_candidates<'a>(
-    resolver: &mut Resolver<'a>,
-    module: Module<'a>,
-    names: &mut Vec<TypoSuggestion>,
-    filter_fn: &impl Fn(Res) -> bool,
-) {
-    for (&(ident, _), resolution) in resolver.resolutions(module).borrow().iter() {
-        if let Some(binding) = resolution.borrow().binding {
-            let res = binding.res();
-            if filter_fn(res) {
-                names.push(TypoSuggestion::from_res(ident.name, res));
+impl<'a> Resolver<'a> {
+    crate fn add_module_candidates(
+        &mut self,
+        module: Module<'a>,
+        names: &mut Vec<TypoSuggestion>,
+        filter_fn: &impl Fn(Res) -> bool,
+    ) {
+        for (&(ident, _), resolution) in self.resolutions(module).borrow().iter() {
+            if let Some(binding) = resolution.borrow().binding {
+                let res = binding.res();
+                if filter_fn(res) {
+                    names.push(TypoSuggestion::from_res(ident.name, res));
+                }
             }
         }
     }
-}
 
-impl<'a> Resolver<'a> {
     /// Combines an error with provided span and emits it.
     ///
     /// This takes the error provided, combines it with the span and any additional spans inside the
@@ -394,10 +394,10 @@ impl<'a> Resolver<'a> {
                 Scope::CrateRoot => {
                     let root_ident = Ident::new(kw::PathRoot, ident.span);
                     let root_module = this.resolve_crate_root(root_ident);
-                    add_module_candidates(this, root_module, &mut suggestions, filter_fn);
+                    this.add_module_candidates(root_module, &mut suggestions, filter_fn);
                 }
                 Scope::Module(module) => {
-                    add_module_candidates(this, module, &mut suggestions, filter_fn);
+                    this.add_module_candidates(module, &mut suggestions, filter_fn);
                 }
                 Scope::MacroUsePrelude => {
                     suggestions.extend(this.macro_use_prelude.iter().filter_map(|(name, binding)| {
@@ -445,7 +445,7 @@ impl<'a> Resolver<'a> {
                 Scope::StdLibPrelude => {
                     if let Some(prelude) = this.prelude {
                         let mut tmp_suggestions = Vec::new();
-                        add_module_candidates(this, prelude, &mut tmp_suggestions, filter_fn);
+                        this.add_module_candidates(prelude, &mut tmp_suggestions, filter_fn);
                         suggestions.extend(tmp_suggestions.into_iter().filter(|s| {
                             use_prelude || this.is_builtin_macro(s.res.opt_def_id())
                         }));
@@ -503,7 +503,7 @@ impl<'a> Resolver<'a> {
                         in_module_is_extern)) = worklist.pop() {
             // We have to visit module children in deterministic order to avoid
             // instabilities in reported imports (#43552).
-            in_module.for_each_child_stable(self, |this, ident, ns, name_binding| {
+            self.for_each_child_stable(in_module, |this, ident, ns, name_binding| {
                 // avoid imports entirely
                 if name_binding.is_import() && !name_binding.is_extern_crate() { return; }
                 // avoid non-importable candidates as well

src/librustc_resolve/late.rs

@@ -1934,7 +1934,7 @@ impl<'a, 'b> LateResolutionVisitor<'a, '_> {
         let mut traits = module.traits.borrow_mut();
         if traits.is_none() {
             let mut collected_traits = Vec::new();
-            module.for_each_child(&mut self.r, |_, name, ns, binding| {
+            self.r.for_each_child(module, |_, name, ns, binding| {
                 if ns != TypeNS { return }
                 match binding.res() {
                     Res::Def(DefKind::Trait, _) |

src/librustc_resolve/late/diagnostics.rs

@@ -1,8 +1,7 @@
 use crate::{CrateLint, Module, ModuleKind, ModuleOrUniformRoot};
 use crate::{PathResult, PathSource, Segment};
 use crate::path_names_to_string;
-use crate::diagnostics::{add_typo_suggestion, add_module_candidates};
-use crate::diagnostics::{ImportSuggestion, TypoSuggestion};
+use crate::diagnostics::{add_typo_suggestion, ImportSuggestion, TypoSuggestion};
 use crate::late::{LateResolutionVisitor, RibKind};
 
 use errors::{Applicability, DiagnosticBuilder, DiagnosticId};
@@ -548,7 +547,7 @@ impl<'a> LateResolutionVisitor<'a, '_> {
                 // Items in scope
                 if let RibKind::ModuleRibKind(module) = rib.kind {
                     // Items from this module
-                    add_module_candidates(&mut self.r, module, &mut names, &filter_fn);
+                    self.r.add_module_candidates(module, &mut names, &filter_fn);
 
                     if let ModuleKind::Block(..) = module.kind {
                         // We can see through blocks
@@ -577,7 +576,7 @@ impl<'a> LateResolutionVisitor<'a, '_> {
                             }));
 
                             if let Some(prelude) = self.r.prelude {
-                                add_module_candidates(&mut self.r, prelude, &mut names, &filter_fn);
+                                self.r.add_module_candidates(prelude, &mut names, &filter_fn);
                             }
                         }
                         break;
@@ -599,7 +598,7 @@ impl<'a> LateResolutionVisitor<'a, '_> {
                 mod_path, Some(TypeNS), false, span, CrateLint::No
             ) {
                 if let ModuleOrUniformRoot::Module(module) = module {
-                    add_module_candidates(&mut self.r, module, &mut names, &filter_fn);
+                    self.r.add_module_candidates(module, &mut names, &filter_fn);
                 }
             }
         }
@@ -717,7 +716,7 @@ impl<'a> LateResolutionVisitor<'a, '_> {
             // abort if the module is already found
             if result.is_some() { break; }
 
-            in_module.for_each_child_stable(&mut self.r, |_, ident, _, name_binding| {
+            self.r.for_each_child_stable(in_module, |_, ident, _, name_binding| {
                 // abort if the module is already found or if name_binding is private external
                 if result.is_some() || !name_binding.vis.is_visible_locally() {
                     return
@@ -749,7 +748,7 @@ impl<'a> LateResolutionVisitor<'a, '_> {
     fn collect_enum_variants(&mut self, def_id: DefId) -> Option<Vec<Path>> {
         self.find_module(def_id).map(|(enum_module, enum_import_suggestion)| {
             let mut variants = Vec::new();
-            enum_module.for_each_child_stable(&mut self.r, |_, ident, _, name_binding| {
+            self.r.for_each_child_stable(enum_module, |_, ident, _, name_binding| {
                 if let Res::Def(DefKind::Variant, _) = name_binding.res() {
                     let mut segms = enum_import_suggestion.path.segments.clone();
                     segms.push(ast::PathSegment::from_ident(ident));

src/librustc_resolve/lib.rs

@@ -50,6 +50,7 @@ use std::collections::BTreeSet;
 use rustc_data_structures::ptr_key::PtrKey;
 use rustc_data_structures::sync::Lrc;
 
+use build_reduced_graph::BuildReducedGraphVisitor;
 use diagnostics::{Suggestion, ImportSuggestion};
 use diagnostics::{find_span_of_binding_until_next_binding, extend_span_to_previous_binding};
 use late::{PathSource, Rib, RibKind::*};
@@ -473,25 +474,6 @@ impl<'a> ModuleData<'a> {
         }
     }
 
-    fn for_each_child<F>(&'a self, resolver: &mut Resolver<'a>, mut f: F)
-        where F: FnMut(&mut Resolver<'a>, Ident, Namespace, &'a NameBinding<'a>)
-    {
-        for (&(ident, ns), name_resolution) in resolver.resolutions(self).borrow().iter() {
-            name_resolution.borrow().binding.map(|binding| f(resolver, ident, ns, binding));
-        }
-    }
-
-    fn for_each_child_stable<F>(&'a self, resolver: &mut Resolver<'a>, mut f: F)
-        where F: FnMut(&mut Resolver<'a>, Ident, Namespace, &'a NameBinding<'a>)
-    {
-        let resolutions = resolver.resolutions(self).borrow();
-        let mut resolutions = resolutions.iter().collect::<Vec<_>>();
-        resolutions.sort_by_cached_key(|&(&(ident, ns), _)| (ident.as_str(), ns));
-        for &(&(ident, ns), &resolution) in resolutions.iter() {
-            resolution.borrow().binding.map(|binding| f(resolver, ident, ns, binding));
-        }
-    }
-
     fn res(&self) -> Option<Res> {
         match self.kind {
             ModuleKind::Def(kind, def_id, _) => Some(Res::Def(kind, def_id)),
@@ -1230,6 +1212,44 @@ impl<'a> Resolver<'a> {
         self.arenas.alloc_module(module)
     }
 
+    fn resolutions(&mut self, module: Module<'a>) -> &'a Resolutions<'a> {
+        if module.populate_on_access.get() {
+            module.populate_on_access.set(false);
+            let def_id = module.def_id().expect("unpopulated module without a def-id");
+            for child in self.cstore.item_children_untracked(def_id, self.session) {
+                let child = child.map_id(|_| panic!("unexpected id"));
+                BuildReducedGraphVisitor { parent_scope: self.dummy_parent_scope(), r: self }
+                    .build_reduced_graph_for_external_crate_res(module, child);
+            }
+        }
+        &module.lazy_resolutions
+    }
+
+    fn resolution(&mut self, module: Module<'a>, ident: Ident, ns: Namespace)
+                  -> &'a RefCell<NameResolution<'a>> {
+        *self.resolutions(module).borrow_mut().entry((ident.modern(), ns))
+               .or_insert_with(|| self.arenas.alloc_name_resolution())
+    }
+
+    fn for_each_child<F>(&mut self, module: Module<'a>, mut f: F)
+        where F: FnMut(&mut Resolver<'a>, Ident, Namespace, &'a NameBinding<'a>)
+    {
+        for (&(ident, ns), name_resolution) in self.resolutions(module).borrow().iter() {
+            name_resolution.borrow().binding.map(|binding| f(self, ident, ns, binding));
+        }
+    }
+
+    fn for_each_child_stable<F>(&mut self, module: Module<'a>, mut f: F)
+        where F: FnMut(&mut Resolver<'a>, Ident, Namespace, &'a NameBinding<'a>)
+    {
+        let resolutions = self.resolutions(module).borrow();
+        let mut resolutions = resolutions.iter().collect::<Vec<_>>();
+        resolutions.sort_by_cached_key(|&(&(ident, ns), _)| (ident.as_str(), ns));
+        for &(&(ident, ns), &resolution) in resolutions.iter() {
+            resolution.borrow().binding.map(|binding| f(self, ident, ns, binding));
+        }
+    }
+
     fn record_use(&mut self, ident: Ident, ns: Namespace,
                   used_binding: &'a NameBinding<'a>, is_lexical_scope: bool) {
         if let Some((b2, kind)) = used_binding.ambiguity {

src/librustc_resolve/resolve_imports.rs

@@ -5,10 +5,8 @@ use crate::{CrateLint, Module, ModuleOrUniformRoot, PerNS, ScopeSet, ParentScope
 use crate::Determinacy::{self, *};
 use crate::Namespace::{self, TypeNS, MacroNS};
 use crate::{NameBinding, NameBindingKind, ToNameBinding, PathResult, PrivacyError};
-use crate::{Resolutions, Resolver, ResolutionError, Segment};
+use crate::{Resolver, ResolutionError, Segment, ModuleKind};
 use crate::{names_to_string, module_to_string};
-use crate::ModuleKind;
-use crate::build_reduced_graph::BuildReducedGraphVisitor;
 use crate::diagnostics::Suggestion;
 
 use errors::Applicability;
@@ -36,7 +34,7 @@ use syntax_pos::{MultiSpan, Span};
 
 use log::*;
 
-use std::cell::{Cell, RefCell};
+use std::cell::Cell;
 use std::{mem, ptr};
 
 type Res = def::Res<NodeId>;
@@ -160,25 +158,6 @@ impl<'a> NameResolution<'a> {
 }
 
 impl<'a> Resolver<'a> {
-    crate fn resolutions(&mut self, module: Module<'a>) -> &'a Resolutions<'a> {
-        if module.populate_on_access.get() {
-            module.populate_on_access.set(false);
-            let def_id = module.def_id().expect("unpopulated module without a def-id");
-            for child in self.cstore.item_children_untracked(def_id, self.session) {
-                let child = child.map_id(|_| panic!("unexpected id"));
-                BuildReducedGraphVisitor { parent_scope: self.dummy_parent_scope(), r: self }
-                    .build_reduced_graph_for_external_crate_res(module, child);
-            }
-        }
-        &module.lazy_resolutions
-    }
-
-    crate fn resolution(&mut self, module: Module<'a>, ident: Ident, ns: Namespace)
-                  -> &'a RefCell<NameResolution<'a>> {
-        *self.resolutions(module).borrow_mut().entry((ident.modern(), ns))
-               .or_insert_with(|| self.arenas.alloc_name_resolution())
-    }
-
     crate fn resolve_ident_in_module_unadjusted(
         &mut self,
         module: ModuleOrUniformRoot<'a>,
@@ -1037,7 +1016,8 @@ impl<'a, 'b> ImportResolver<'a, 'b> {
 
             return if all_ns_failed {
                 let resolutions = match module {
-                    ModuleOrUniformRoot::Module(module) => Some(self.r.resolutions(module).borrow()),
+                    ModuleOrUniformRoot::Module(module) =>
+                        Some(self.r.resolutions(module).borrow()),
                     _ => None,
                 };
                 let resolutions = resolutions.as_ref().into_iter().flat_map(|r| r.iter());
@@ -1290,8 +1270,8 @@ impl<'a, 'b> ImportResolver<'a, 'b> {
 
         // Ensure that `resolutions` isn't borrowed during `try_define`,
         // since it might get updated via a glob cycle.
-        let bindings = self.r.resolutions(module).borrow().iter().filter_map(|(&ident, resolution)| {
-            resolution.borrow().binding().map(|binding| (ident, binding))
+        let bindings = self.r.resolutions(module).borrow().iter().filter_map(|(ident, resolution)| {
+            resolution.borrow().binding().map(|binding| (*ident, binding))
         }).collect::<Vec<_>>();
         for ((mut ident, ns), binding) in bindings {
             let scope = match ident.span.reverse_glob_adjust(module.expansion, directive.span) {

src/test/ui/imports/extern-prelude-extern-crate-restricted-shadowing.stderr

@@ -13,15 +13,19 @@ error[E0659]: `Vec` is ambiguous (macro-expanded name vs less macro-expanded nam
 LL |         Vec::panic!();
    |         ^^^ ambiguous name
    |
-   = note: `Vec` could refer to a struct from prelude
-note: `Vec` could also refer to the crate imported here
+note: `Vec` could refer to the crate imported here
   --> $DIR/extern-prelude-extern-crate-restricted-shadowing.rs:5:9
    |
 LL |         extern crate std as Vec;
    |         ^^^^^^^^^^^^^^^^^^^^^^^^
 ...
 LL | define_vec!();
    | -------------- in this macro invocation
+note: `Vec` could also refer to the struct defined here
+  --> $SRC_DIR/libstd/prelude/v1.rs:LL:COL
+   |
+LL | pub use crate::vec::Vec;
+   |         ^^^^^^^^^^^^^^^
 
 error: aborting due to 2 previous errors