Merge #2962

2962: Differentiate underscore alias from named aliases r=matklad a=zombiefungus

pre for Fixing Issue 2736 
edited to avoid autoclosing the issue

Co-authored-by: zombiefungus <[email protected]>

2 files changed, 17 insertions, 6 deletions

diff --git a/crates/ra_hir_def/src/nameres/collector.rs b/crates/ra_hir_def/src/nameres/collector.rs
index 7499dff31..6352c71ef 100644
--- a/crates/ra_hir_def/src/nameres/collector.rs
+++ b/crates/ra_hir_def/src/nameres/collector.rs
@@ -22,7 +22,7 @@ use crate::{
         diagnostics::DefDiagnostic, mod_resolution::ModDir, path_resolution::ReachedFixedPoint,
         raw, BuiltinShadowMode, CrateDefMap, ModuleData, ModuleOrigin, ResolveMode,
     },
-    path::{ModPath, PathKind},
+    path::{ImportAlias, ModPath, PathKind},
     per_ns::PerNs,
     visibility::Visibility,
     AdtId, AstId, ConstLoc, ContainerId, EnumLoc, EnumVariantId, FunctionLoc, ImplLoc, Intern,
@@ -438,7 +438,11 @@ where
         } else {
             match import.path.segments.last() {
                 Some(last_segment) => {
-                    let name = import.alias.clone().unwrap_or_else(|| last_segment.clone());
+                    let name = match &import.alias {
+                        Some(ImportAlias::Alias(name)) => name.clone(),
+                        Some(ImportAlias::Underscore) => last_segment.clone(), // FIXME rust-analyzer#2736
+                        None => last_segment.clone(),
+                    };
                     log::debug!("resolved import {:?} ({:?}) to {:?}", name, import, def);
 
                     // extern crates in the crate root are special-cased to insert entries into the extern prelude: rust-lang/rust#54658
diff --git a/crates/ra_hir_def/src/nameres/raw.rs b/crates/ra_hir_def/src/nameres/raw.rs
index fac1169ef..650cf1f98 100644
--- a/crates/ra_hir_def/src/nameres/raw.rs
+++ b/crates/ra_hir_def/src/nameres/raw.rs
@@ -22,8 +22,11 @@ use ra_syntax::{
 use test_utils::tested_by;
 
 use crate::{
-    attr::Attrs, db::DefDatabase, path::ModPath, visibility::RawVisibility, FileAstId, HirFileId,
-    InFile,
+    attr::Attrs,
+    db::DefDatabase,
+    path::{ImportAlias, ModPath},
+    visibility::RawVisibility,
+    FileAstId, HirFileId, InFile,
 };
 
 /// `RawItems` is a set of top-level items in a file (except for impls).
@@ -145,7 +148,7 @@ impl_arena_id!(Import);
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct ImportData {
     pub(super) path: ModPath,
-    pub(super) alias: Option<Name>,
+    pub(super) alias: Option<ImportAlias>,
     pub(super) is_glob: bool,
     pub(super) is_prelude: bool,
     pub(super) is_extern_crate: bool,
@@ -353,7 +356,11 @@ impl RawItemsCollector {
             let path = ModPath::from_name_ref(&name_ref);
             let visibility =
                 RawVisibility::from_ast_with_hygiene(extern_crate.visibility(), &self.hygiene);
-            let alias = extern_crate.alias().and_then(|a| a.name()).map(|it| it.as_name());
+            let alias = extern_crate.alias().map(|a| {
+                a.name()
+                    .map(|it| it.as_name())
+                    .map_or(ImportAlias::Underscore, |a| ImportAlias::Alias(a))
+            });
             let attrs = self.parse_attrs(&extern_crate);
             // FIXME: cfg_attr
             let is_macro_use = extern_crate.has_atom_attr("macro_use");