5 files changed, 94 insertions, 59 deletions

diff --git a/crates/ide_completion/src/completions.rs b/crates/ide_completion/src/completions.rs
index bd90cefb2..aef70f26a 100644
--- a/crates/ide_completion/src/completions.rs
+++ b/crates/ide_completion/src/completions.rs
@@ -109,9 +109,6 @@ impl Completions {
         local_name: hir::Name,
         resolution: &hir::ScopeDef,
     ) {
-        if ctx.expects_type() && resolution.is_value_def() {
-            return;
-        }
         self.add_opt(render_resolution(RenderContext::new(ctx), local_name, resolution));
     }
 
diff --git a/crates/ide_completion/src/completions/qualified_path.rs b/crates/ide_completion/src/completions/qualified_path.rs
index 6083537b7..1643eeed4 100644
--- a/crates/ide_completion/src/completions/qualified_path.rs
+++ b/crates/ide_completion/src/completions/qualified_path.rs
@@ -19,6 +19,7 @@ pub(crate) fn complete_qualified_path(acc: &mut Completions, ctx: &CompletionCon
         Some(res) => res,
         None => return,
     };
+
     let context_module = ctx.scope.module();
 
     if ctx.expects_item() || ctx.expects_assoc_item() {
@@ -60,21 +61,31 @@ pub(crate) fn complete_qualified_path(acc: &mut Completions, ctx: &CompletionCon
                     }
                 }
 
-                if let hir::ScopeDef::MacroDef(macro_def) = def {
-                    if !macro_def.is_fn_like() {
-                        // Don't suggest attribute macros and derives.
-                        continue;
+                let add_resolution = match def {
+                    // Don't suggest attribute macros and derives.
+                    hir::ScopeDef::MacroDef(mac) => mac.is_fn_like(),
+                    // no values in type places
+                    hir::ScopeDef::ModuleDef(hir::ModuleDef::Function(_))
+                    | hir::ScopeDef::ModuleDef(hir::ModuleDef::Variant(_))
+                    | hir::ScopeDef::ModuleDef(hir::ModuleDef::Static(_))
+                    | hir::ScopeDef::Local(_) => !ctx.expects_type(),
+                    // unless its a constant in a generic arg list position
+                    hir::ScopeDef::ModuleDef(hir::ModuleDef::Const(_)) => {
+                        !ctx.expects_type() || ctx.expects_generic_arg()
                     }
-                }
+                    _ => true,
+                };
 
-                acc.add_resolution(ctx, name, &def);
+                if add_resolution {
+                    acc.add_resolution(ctx, name, &def);
+                }
             }
         }
         hir::PathResolution::Def(def @ hir::ModuleDef::Adt(_))
         | hir::PathResolution::Def(def @ hir::ModuleDef::TypeAlias(_))
         | hir::PathResolution::Def(def @ hir::ModuleDef::BuiltinType(_)) => {
             if let hir::ModuleDef::Adt(hir::Adt::Enum(e)) = def {
-                add_enum_variants(ctx, acc, e);
+                add_enum_variants(acc, ctx, e);
             }
             let ty = match def {
                 hir::ModuleDef::Adt(adt) => adt.ty(ctx.db),
@@ -82,7 +93,7 @@ pub(crate) fn complete_qualified_path(acc: &mut Completions, ctx: &CompletionCon
                     let ty = a.ty(ctx.db);
                     if let Some(hir::Adt::Enum(e)) = ty.as_adt() {
                         cov_mark::hit!(completes_variant_through_alias);
-                        add_enum_variants(ctx, acc, e);
+                        add_enum_variants(acc, ctx, e);
                     }
                     ty
                 }
@@ -107,11 +118,7 @@ pub(crate) fn complete_qualified_path(acc: &mut Completions, ctx: &CompletionCon
                     if context_module.map_or(false, |m| !item.is_visible_from(ctx.db, m)) {
                         return None;
                     }
-                    match item {
-                        hir::AssocItem::Function(func) => acc.add_function(ctx, func, None),
-                        hir::AssocItem::Const(ct) => acc.add_const(ctx, ct),
-                        hir::AssocItem::TypeAlias(ty) => acc.add_type_alias(ctx, ty),
-                    }
+                    add_assoc_item(acc, ctx, item);
                     None::<()>
                 });
 
@@ -133,11 +140,7 @@ pub(crate) fn complete_qualified_path(acc: &mut Completions, ctx: &CompletionCon
                 if context_module.map_or(false, |m| !item.is_visible_from(ctx.db, m)) {
                     continue;
                 }
-                match item {
-                    hir::AssocItem::Function(func) => acc.add_function(ctx, func, None),
-                    hir::AssocItem::Const(ct) => acc.add_const(ctx, ct),
-                    hir::AssocItem::TypeAlias(ty) => acc.add_type_alias(ctx, ty),
-                }
+                add_assoc_item(acc, ctx, item);
             }
         }
         hir::PathResolution::TypeParam(_) | hir::PathResolution::SelfType(_) => {
@@ -149,7 +152,7 @@ pub(crate) fn complete_qualified_path(acc: &mut Completions, ctx: &CompletionCon
                 };
 
                 if let Some(hir::Adt::Enum(e)) = ty.as_adt() {
-                    add_enum_variants(ctx, acc, e);
+                    add_enum_variants(acc, ctx, e);
                 }
 
                 let traits_in_scope = ctx.scope.traits_in_scope();
@@ -162,11 +165,7 @@ pub(crate) fn complete_qualified_path(acc: &mut Completions, ctx: &CompletionCon
                     // We might iterate candidates of a trait multiple times here, so deduplicate
                     // them.
                     if seen.insert(item) {
-                        match item {
-                            hir::AssocItem::Function(func) => acc.add_function(ctx, func, None),
-                            hir::AssocItem::Const(ct) => acc.add_const(ctx, ct),
-                            hir::AssocItem::TypeAlias(ty) => acc.add_type_alias(ctx, ty),
-                        }
+                        add_assoc_item(acc, ctx, item);
                     }
                     None::<()>
                 });
@@ -176,10 +175,22 @@ pub(crate) fn complete_qualified_path(acc: &mut Completions, ctx: &CompletionCon
     }
 }
 
-fn add_enum_variants(ctx: &CompletionContext, acc: &mut Completions, e: hir::Enum) {
-    for variant in e.variants(ctx.db) {
-        acc.add_enum_variant(ctx, variant, None);
+fn add_assoc_item(acc: &mut Completions, ctx: &CompletionContext, item: hir::AssocItem) {
+    match item {
+        hir::AssocItem::Function(func) if !ctx.expects_type() => acc.add_function(ctx, func, None),
+        hir::AssocItem::Const(ct) if !ctx.expects_type() || ctx.expects_generic_arg() => {
+            acc.add_const(ctx, ct)
+        }
+        hir::AssocItem::TypeAlias(ty) => acc.add_type_alias(ctx, ty),
+        _ => (),
+    }
+}
+
+fn add_enum_variants(acc: &mut Completions, ctx: &CompletionContext, e: hir::Enum) {
+    if ctx.expects_type() {
+        return;
     }
+    e.variants(ctx.db).into_iter().for_each(|variant| acc.add_enum_variant(ctx, variant, None));
 }
 
 #[cfg(test)]
@@ -927,4 +938,24 @@ fn main() {
             "#]],
         );
     }
+
+    #[test]
+    fn completes_types_and_const_in_arg_list() {
+        check(
+            r#"
+mod foo {
+    pub const CONST: () = ();
+    pub type Type = ();
+}
+
+struct Foo<T>(t);
+
+fn foo(_: Foo<foo::$0>) {}
+"#,
+            expect![[r#"
+                ta Type
+                ct CONST
+            "#]],
+        );
+    }
 }
diff --git a/crates/ide_completion/src/completions/unqualified_path.rs b/crates/ide_completion/src/completions/unqualified_path.rs
index f86b2d3f3..b5af1c810 100644
--- a/crates/ide_completion/src/completions/unqualified_path.rs
+++ b/crates/ide_completion/src/completions/unqualified_path.rs
@@ -36,12 +36,14 @@ pub(crate) fn complete_unqualified_path(acc: &mut Completions, ctx: &CompletionC
         return;
     }
 
-    if let Some(hir::Adt::Enum(e)) =
-        ctx.expected_type.as_ref().and_then(|ty| ty.strip_references().as_adt())
-    {
-        super::complete_enum_variants(acc, ctx, e, |acc, ctx, variant, path| {
-            acc.add_qualified_enum_variant(ctx, variant, path)
-        });
+    if !ctx.expects_type() {
+        if let Some(hir::Adt::Enum(e)) =
+            ctx.expected_type.as_ref().and_then(|ty| ty.strip_references().as_adt())
+        {
+            super::complete_enum_variants(acc, ctx, e, |acc, ctx, variant, path| {
+                acc.add_qualified_enum_variant(ctx, variant, path)
+            });
+        }
     }
 
     if let Some(ImmediateLocation::GenericArgList(arg_list)) = &ctx.completion_location {
@@ -59,12 +61,25 @@ pub(crate) fn complete_unqualified_path(acc: &mut Completions, ctx: &CompletionC
     }
 
     ctx.scope.process_all_names(&mut |name, res| {
-        if let ScopeDef::GenericParam(hir::GenericParam::LifetimeParam(_)) = res {
+        if let ScopeDef::GenericParam(hir::GenericParam::LifetimeParam(_)) | ScopeDef::Label(_) =
+            res
+        {
             cov_mark::hit!(skip_lifetime_completion);
             return;
         }
         let add_resolution = match res {
+            // Don't suggest attribute macros and derives.
             ScopeDef::MacroDef(mac) => mac.is_fn_like(),
+            // no values in type places
+            ScopeDef::ModuleDef(hir::ModuleDef::Function(_))
+            | ScopeDef::ModuleDef(hir::ModuleDef::Variant(_))
+            | ScopeDef::ModuleDef(hir::ModuleDef::Static(_))
+            | ScopeDef::Local(_) => !ctx.expects_type(),
+            // unless its a constant in a generic arg list position
+            ScopeDef::ModuleDef(hir::ModuleDef::Const(_))
+            | ScopeDef::GenericParam(hir::GenericParam::ConstParam(_)) => {
+                !ctx.expects_type() || ctx.expects_generic_arg()
+            }
             _ => true,
         };
         if add_resolution {
@@ -794,36 +809,27 @@ $0
     }
 
     #[test]
-    fn completes_assoc_types_in_dynimpl_trait() {
+    fn completes_types_and_const_in_arg_list() {
         check(
             r#"
-trait Foo {
-    type Bar;
+enum Bar {
+    Baz
 }
-
-fn foo(_: impl Foo<B$0>) {}
-"#,
-            expect![[r#"
-                ta Bar =  type Bar;
-                tt Foo
-            "#]],
-        );
-    }
-
-    #[test]
-    fn completes_assoc_types_in_trait_bound() {
-        check(
-            r#"
 trait Foo {
     type Bar;
 }
 
-fn foo<T: Foo<B$0>>(_: T) {}
+const CONST: () = ();
+
+fn foo<T: Foo<$0>, const CONST_PARAM: usize>(_: T) {}
 "#,
             expect![[r#"
-                ta Bar =  type Bar;
+                ta Bar =       type Bar;
                 tp T
+                cp CONST_PARAM
                 tt Foo
+                en Bar
+                ct CONST
             "#]],
         );
     }
diff --git a/crates/ide_completion/src/context.rs b/crates/ide_completion/src/context.rs
index 4c3929a26..a8437d81c 100644
--- a/crates/ide_completion/src/context.rs
+++ b/crates/ide_completion/src/context.rs
@@ -276,6 +276,10 @@ impl<'a> CompletionContext<'a> {
         matches!(self.completion_location, Some(ImmediateLocation::ItemList))
     }
 
+    pub(crate) fn expects_generic_arg(&self) -> bool {
+        matches!(self.completion_location, Some(ImmediateLocation::GenericArgList(_)))
+    }
+
     pub(crate) fn has_block_expr_parent(&self) -> bool {
         matches!(self.completion_location, Some(ImmediateLocation::BlockExpr))
     }
diff --git a/crates/ide_completion/src/render.rs b/crates/ide_completion/src/render.rs
index fac83b650..70bf26cf4 100644
--- a/crates/ide_completion/src/render.rs
+++ b/crates/ide_completion/src/render.rs
@@ -55,9 +55,6 @@ pub(crate) fn render_resolution_with_import(
     import_edit: ImportEdit,
 ) -> Option<CompletionItem> {
     let resolution = hir::ScopeDef::from(import_edit.import.original_item);
-    if ctx.completion.expects_type() && resolution.is_value_def() {
-        return None;
-    }
     let local_name = match resolution {
         hir::ScopeDef::ModuleDef(hir::ModuleDef::Function(f)) => f.name(ctx.completion.db),
         hir::ScopeDef::ModuleDef(hir::ModuleDef::Const(c)) => c.name(ctx.completion.db)?,