From 001a86dc03104b75df732d69257d22526cf422b7 Mon Sep 17 00:00:00 2001
From: Hasan Ali <git@hasali.co.uk>
Date: Fri, 15 May 2020 22:23:49 +0100
Subject: Fix completion and hover for module and function of same name

---
 crates/ra_hir/src/semantics.rs       |  6 ++++-
 crates/ra_hir/src/source_analyzer.rs | 51 ++++++++++++++++++++++++++++++++++++
 2 files changed, 56 insertions(+), 1 deletion(-)

(limited to 'crates/ra_hir')

diff --git a/crates/ra_hir/src/semantics.rs b/crates/ra_hir/src/semantics.rs
index 515e5eb17..c1129a494 100644
--- a/crates/ra_hir/src/semantics.rs
+++ b/crates/ra_hir/src/semantics.rs
@@ -23,7 +23,7 @@ use crate::{
     db::HirDatabase,
     diagnostics::Diagnostic,
     semantics::source_to_def::{ChildContainer, SourceToDefCache, SourceToDefCtx},
-    source_analyzer::{resolve_hir_path, SourceAnalyzer},
+    source_analyzer::{resolve_hir_path, resolve_hir_path_qualifier, SourceAnalyzer},
     AssocItem, Field, Function, HirFileId, ImplDef, InFile, Local, MacroDef, Module, ModuleDef,
     Name, Origin, Path, ScopeDef, Trait, Type, TypeAlias, TypeParam,
 };
@@ -451,6 +451,10 @@ impl<'a, DB: HirDatabase> SemanticsScope<'a, DB> {
     pub fn resolve_hir_path(&self, path: &Path) -> Option<PathResolution> {
         resolve_hir_path(self.db, &self.resolver, path)
     }
+
+    pub fn resolve_hir_path_qualifier(&self, path: &Path) -> Option<PathResolution> {
+        resolve_hir_path_qualifier(self.db, &self.resolver, path)
+    }
 }
 
 // FIXME: Change `HasSource` trait to work with `Semantics` and remove this?
diff --git a/crates/ra_hir/src/source_analyzer.rs b/crates/ra_hir/src/source_analyzer.rs
index c862a4f48..4b509f07c 100644
--- a/crates/ra_hir/src/source_analyzer.rs
+++ b/crates/ra_hir/src/source_analyzer.rs
@@ -226,6 +226,17 @@ impl SourceAnalyzer {
         // This must be a normal source file rather than macro file.
         let hir_path =
             crate::Path::from_src(path.clone(), &Hygiene::new(db.upcast(), self.file_id))?;
+
+        // Case where path is a qualifier of another path, e.g. foo::bar::Baz where we
+        // trying to resolve foo::bar.
+        if let Some(outer_path) = path.syntax().parent().and_then(ast::Path::cast) {
+            if let Some(qualifier) = outer_path.qualifier() {
+                if path == &qualifier {
+                    return resolve_hir_path_qualifier(db, &self.resolver, &hir_path);
+                }
+            }
+        }
+
         resolve_hir_path(db, &self.resolver, &hir_path)
     }
 
@@ -404,6 +415,7 @@ pub(crate) fn resolve_hir_path(
             TypeNs::BuiltinType(it) => PathResolution::Def(it.into()),
             TypeNs::TraitId(it) => PathResolution::Def(Trait::from(it).into()),
         });
+
     let body_owner = resolver.body_owner();
     let values =
         resolver.resolve_path_in_value_ns_fully(db.upcast(), path.mod_path()).and_then(|val| {
@@ -426,9 +438,48 @@ pub(crate) fn resolve_hir_path(
         .resolve_module_path_in_items(db.upcast(), path.mod_path())
         .take_types()
         .map(|it| PathResolution::Def(it.into()));
+
     types.or(values).or(items).or_else(|| {
         resolver
             .resolve_path_as_macro(db.upcast(), path.mod_path())
             .map(|def| PathResolution::Macro(def.into()))
     })
 }
+
+/// Resolves a path where we know it is a qualifier of another path.
+///
+/// For example, if we have:
+/// ```
+/// mod my {
+///     pub mod foo {
+///         struct Bar;
+///     }
+///
+///     pub fn foo() {}
+/// }
+/// ```
+/// then we know that `foo` in `my::foo::Bar` refers to the module, not the function.
+pub(crate) fn resolve_hir_path_qualifier(
+    db: &dyn HirDatabase,
+    resolver: &Resolver,
+    path: &crate::Path,
+) -> Option<PathResolution> {
+    let items = resolver
+        .resolve_module_path_in_items(db.upcast(), path.mod_path())
+        .take_types()
+        .map(|it| PathResolution::Def(it.into()));
+
+    if items.is_some() {
+        return items;
+    }
+
+    resolver.resolve_path_in_type_ns_fully(db.upcast(), path.mod_path()).map(|ty| match ty {
+        TypeNs::SelfType(it) => PathResolution::SelfType(it.into()),
+        TypeNs::GenericParam(id) => PathResolution::TypeParam(TypeParam { id }),
+        TypeNs::AdtSelfType(it) | TypeNs::AdtId(it) => PathResolution::Def(Adt::from(it).into()),
+        TypeNs::EnumVariantId(it) => PathResolution::Def(EnumVariant::from(it).into()),
+        TypeNs::TypeAliasId(it) => PathResolution::Def(TypeAlias::from(it).into()),
+        TypeNs::BuiltinType(it) => PathResolution::Def(it.into()),
+        TypeNs::TraitId(it) => PathResolution::Def(Trait::from(it).into()),
+    })
+}
-- 
cgit v1.2.3