3 files changed, 46 insertions, 7 deletions

diff --git a/crates/hir_def/src/nameres/collector.rs b/crates/hir_def/src/nameres/collector.rs
index 0e741194b..be645a25d 100644
--- a/crates/hir_def/src/nameres/collector.rs
+++ b/crates/hir_def/src/nameres/collector.rs
@@ -367,6 +367,8 @@ impl DefCollector<'_> {
     /// This improves UX when proc macros are turned off or don't work, and replicates the behavior
     /// before we supported proc. attribute macros.
     fn reseed_with_unresolved_attributes(&mut self) -> ReachedFixedPoint {
+        cov_mark::hit!(unresolved_attribute_fallback);
+
         let mut added_items = false;
         let unexpanded_macros = std::mem::replace(&mut self.unexpanded_macros, Vec::new());
         for directive in &unexpanded_macros {
@@ -391,7 +393,9 @@ impl DefCollector<'_> {
                 added_items = true;
             }
         }
-        self.unexpanded_macros = unexpanded_macros;
+
+        // The collection above might add new unresolved macros (eg. derives), so merge the lists.
+        self.unexpanded_macros.extend(unexpanded_macros);
 
         if added_items {
             // Continue name resolution with the new data.
diff --git a/crates/hir_def/src/nameres/tests/macros.rs b/crates/hir_def/src/nameres/tests/macros.rs
index c37f915ab..b34ba885d 100644
--- a/crates/hir_def/src/nameres/tests/macros.rs
+++ b/crates/hir_def/src/nameres/tests/macros.rs
@@ -686,6 +686,27 @@ pub trait Clone {}
 }
 
 #[test]
+fn builtin_derive_with_unresolved_attributes_fall_back() {
+    // Tests that we still resolve derives after ignoring an unresolved attribute.
+    cov_mark::check!(unresolved_attribute_fallback);
+    let map = compute_crate_def_map(
+        r#"
+        //- /main.rs crate:main deps:core
+        use core::Clone;
+
+        #[derive(Clone)]
+        #[unresolved]
+        struct Foo;
+
+        //- /core.rs crate:core
+        #[rustc_builtin_macro]
+        pub macro Clone {}
+        "#,
+    );
+    assert_eq!(map.modules[map.root].scope.impls().len(), 1);
+}
+
+#[test]
 fn macro_expansion_overflow() {
     cov_mark::check!(macro_expansion_overflow);
     check(
@@ -842,7 +863,6 @@ fn collects_derive_helpers() {
 fn resolve_macro_def() {
     check(
         r#"
-//- /lib.rs
 pub macro structs($($i:ident),*) {
     $(struct $i { field: u32 } )*
 }
diff --git a/crates/ide_assists/src/handlers/add_explicit_type.rs b/crates/ide_assists/src/handlers/add_explicit_type.rs
index 36589203d..b7617ca3d 100644
--- a/crates/ide_assists/src/handlers/add_explicit_type.rs
+++ b/crates/ide_assists/src/handlers/add_explicit_type.rs
@@ -1,6 +1,6 @@
 use hir::HirDisplay;
 use syntax::{
-    ast::{self, AstNode, LetStmt, NameOwner},
+    ast::{self, AstNode, LetStmt},
     TextRange,
 };
 
@@ -31,9 +31,6 @@ pub(crate) fn add_explicit_type(acc: &mut Assists, ctx: &AssistContext) -> Optio
         _ => return None,
     };
     let pat_range = pat.syntax().text_range();
-    // The binding must have a name
-    let name = pat.name()?;
-    let name_range = name.syntax().text_range();
 
     // Assist should only be applicable if cursor is between 'let' and '='
     let cursor_in_range = {
@@ -74,7 +71,7 @@ pub(crate) fn add_explicit_type(acc: &mut Assists, ctx: &AssistContext) -> Optio
                 builder.replace(ascribed_ty.syntax().text_range(), inferred_type);
             }
             None => {
-                builder.insert(name_range.end(), format!(": {}", inferred_type));
+                builder.insert(pat_range.end(), format!(": {}", inferred_type));
             }
         },
     )
@@ -246,4 +243,22 @@ fn main() {
 "#,
         );
     }
+
+    #[test]
+    fn type_should_be_added_after_pattern() {
+        // LetStmt = Attr* 'let' Pat (':' Type)? '=' initializer:Expr ';'
+        check_assist(
+            add_explicit_type,
+            r#"
+fn main() {
+    let $0test @ () = ();
+}
+"#,
+            r#"
+fn main() {
+    let test @ (): () = ();
+}
+"#,
+        );
+    }
 }