Merge pull request #76299 from xedin/rdar-135203192

Revert "[CSBindings] Mark generic parameter type vars as complete if they don't have any adjacent vars"

Author: xedin

lib/Sema/CSBindings.cpp

@@ -174,30 +174,9 @@ bool BindingSet::involvesTypeVariables() const {
 }
 
 bool BindingSet::isPotentiallyIncomplete() const {
-  // Always marking generic parameter type variables as incomplete
-  // is too aggressive. That was the way to make sure that they
-  // are never attempted to eagerly, but really there are only a
-  // couple of situations where that can cause issues:
-  //
-  // 1. Int <: $T_param
-  //    $T1 <: $T_param
-  //
-  // 2. $T2 conv Generic<$T_param>
-  //    $T2 conv Generic<Int?>
-  //    Int <: $T_param
-  //
-  // Attempting $T_param before $T1 in 1. could result in a missed
-  // optional type binding for example.
-  //
-  // Attempting $T_param too early in this case (before $T2) could
-  // miss some transitive bindings inferred through conversion
-  // of `Generic` type.
-  //
-  // If a type variable that represents a generic parameter is no longer
-  // associated with any type variables (directly or indirectly) it's safe
-  // to assume that its binding set is complete.
+  // Generic parameters are always potentially incomplete.
   if (Info.isGenericParameter())
-    return involvesTypeVariables();
+    return true;
 
   // Key path literal type is incomplete until there is a
   // contextual type or key path is resolved enough to infer

test/Constraints/array_literal.swift

@@ -393,3 +393,25 @@ struct TestMultipleOverloadedInits {
     let _ = [Float(x), Float(x), Float(x), Float(x)]
   }
 }
+
+do {
+  struct Section {
+    var rows: [Row<Any>]?
+  }
+
+  struct Row<T> {
+      init(value: T?) {}
+  }
+
+  struct Asset {
+    var orientation: Int32
+  }
+
+  func test(asset: Asset) -> [Section] {
+    return [
+      Section(rows: [
+        Row(value: String(describing: asset.orientation)) // Ok
+      ])
+    ]
+  }
+}