4 files changed, 120 insertions, 14 deletions

diff --git a/crates/ra_hir/src/code_model.rs b/crates/ra_hir/src/code_model.rs
index af59aa1b6..840cfdfc8 100644
--- a/crates/ra_hir/src/code_model.rs
+++ b/crates/ra_hir/src/code_model.rs
@@ -19,11 +19,14 @@ use hir_def::{
 use hir_expand::{
     diagnostics::DiagnosticSink,
     name::{name, AsName},
-    MacroDefId,
+    MacroDefId, MacroDefKind,
 };
 use hir_ty::{
-    autoderef, display::HirFormatter, expr::ExprValidator, method_resolution, ApplicationTy,
-    Canonical, InEnvironment, Substs, TraitEnvironment, Ty, TyDefId, TypeCtor,
+    autoderef,
+    display::{HirDisplayError, HirFormatter},
+    expr::ExprValidator,
+    method_resolution, ApplicationTy, Canonical, InEnvironment, Substs, TraitEnvironment, Ty,
+    TyDefId, TypeCtor,
 };
 use ra_db::{CrateId, CrateName, Edition, FileId};
 use ra_prof::profile;
@@ -145,6 +148,26 @@ impl ModuleDef {
             ModuleDef::BuiltinType(_) => None,
         }
     }
+
+    pub fn definition_visibility(&self, db: &dyn HirDatabase) -> Option<Visibility> {
+        let module = match self {
+            ModuleDef::Module(it) => it.parent(db)?,
+            ModuleDef::Function(it) => return Some(it.visibility(db)),
+            ModuleDef::Adt(it) => it.module(db),
+            ModuleDef::EnumVariant(it) => {
+                let parent = it.parent_enum(db);
+                let module = it.module(db);
+                return module.visibility_of(db, &ModuleDef::Adt(Adt::Enum(parent)));
+            }
+            ModuleDef::Const(it) => return Some(it.visibility(db)),
+            ModuleDef::Static(it) => it.module(db),
+            ModuleDef::Trait(it) => it.module(db),
+            ModuleDef::TypeAlias(it) => return Some(it.visibility(db)),
+            ModuleDef::BuiltinType(_) => return None,
+        };
+
+        module.visibility_of(db, self)
+    }
 }
 
 pub use hir_def::{
@@ -675,6 +698,10 @@ impl Static {
     pub fn name(self, db: &dyn HirDatabase) -> Option<Name> {
         db.static_data(self.id).name.clone()
     }
+
+    pub fn is_mut(self, db: &dyn HirDatabase) -> bool {
+        db.static_data(self.id).mutable
+    }
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
@@ -762,13 +789,12 @@ impl MacroDef {
 
     /// Indicate it is a proc-macro
     pub fn is_proc_macro(&self) -> bool {
-        match self.id.kind {
-            hir_expand::MacroDefKind::Declarative => false,
-            hir_expand::MacroDefKind::BuiltIn(_) => false,
-            hir_expand::MacroDefKind::BuiltInDerive(_) => false,
-            hir_expand::MacroDefKind::BuiltInEager(_) => false,
-            hir_expand::MacroDefKind::CustomDerive(_) => true,
-        }
+        matches!(self.id.kind, MacroDefKind::CustomDerive(_))
+    }
+
+    /// Indicate it is a derive macro
+    pub fn is_derive_macro(&self) -> bool {
+        matches!(self.id.kind, MacroDefKind::CustomDerive(_) | MacroDefKind::BuiltInDerive(_))
     }
 }
 
@@ -963,6 +989,17 @@ impl TypeParam {
             ty: InEnvironment { value: ty, environment },
         }
     }
+
+    pub fn default(self, db: &dyn HirDatabase) -> Option<Type> {
+        let params = db.generic_defaults(self.id.parent);
+        let local_idx = hir_ty::param_idx(db, self.id)?;
+        let resolver = self.id.parent.resolver(db.upcast());
+        let environment = TraitEnvironment::lower(db, &resolver);
+        params.get(local_idx).cloned().map(|ty| Type {
+            krate: self.id.parent.module(db.upcast()).krate,
+            ty: InEnvironment { value: ty, environment },
+        })
+    }
 }
 
 // FIXME: rename from `ImplDef` to `Impl`
@@ -1212,7 +1249,7 @@ impl Type {
 
     // This would be nicer if it just returned an iterator, but that runs into
     // lifetime problems, because we need to borrow temp `CrateImplDefs`.
-    pub fn iterate_impl_items<T>(
+    pub fn iterate_assoc_items<T>(
         self,
         db: &dyn HirDatabase,
         krate: Crate,
@@ -1320,7 +1357,7 @@ impl Type {
 }
 
 impl HirDisplay for Type {
-    fn hir_fmt(&self, f: &mut HirFormatter) -> std::fmt::Result {
+    fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
         self.ty.value.hir_fmt(f)
     }
 }
diff --git a/crates/ra_hir/src/semantics.rs b/crates/ra_hir/src/semantics.rs
index 515e5eb17..7c1f79f27 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 +451,23 @@ 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)
     }
+
+    /// 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 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/semantics/source_to_def.rs b/crates/ra_hir/src/semantics/source_to_def.rs
index 6f3b5b2da..8af64fdc1 100644
--- a/crates/ra_hir/src/semantics/source_to_def.rs
+++ b/crates/ra_hir/src/semantics/source_to_def.rs
@@ -151,7 +151,7 @@ impl SourceToDefCtx<'_, '_> {
         let krate = self.file_to_def(file_id)?.krate;
         let file_ast_id = self.db.ast_id_map(src.file_id).ast_id(&src.value);
         let ast_id = Some(AstId::new(src.file_id, file_ast_id));
-        Some(MacroDefId { krate: Some(krate), ast_id, kind })
+        Some(MacroDefId { krate: Some(krate), ast_id, kind, local_inner: false })
     }
 
     pub(super) fn find_container(&mut self, src: InFile<&SyntaxNode>) -> Option<ChildContainer> {
diff --git a/crates/ra_hir/src/source_analyzer.rs b/crates/ra_hir/src/source_analyzer.rs
index c63d1b847..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| {
@@ -417,6 +429,7 @@ pub(crate) fn resolve_hir_path(
                 ValueNs::StaticId(it) => PathResolution::Def(Static::from(it).into()),
                 ValueNs::StructId(it) => PathResolution::Def(Struct::from(it).into()),
                 ValueNs::EnumVariantId(it) => PathResolution::Def(EnumVariant::from(it).into()),
+                ValueNs::ImplSelf(impl_id) => PathResolution::SelfType(impl_id.into()),
             };
             Some(res)
         });
@@ -425,9 +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()),
+    })
+}