Sema: Split off inferTransitiveKeyPathBindings() from BindingSet::inferTransitiveBindings()

Author: slavapestov

include/swift/Sema/CSBindings.h

@@ -551,6 +551,8 @@ class BindingSet {
   /// variables in the workset.
   void inferTransitiveBindings();
 
+  void inferTransitiveKeyPathBindings();
+
   /// Detect subtype, conversion or equivalence relationship
   /// between two type variables and attempt to propagate protocol
   /// requirements down the subtype or equivalence chain.

lib/Sema/CSBindings.cpp

@@ -493,9 +493,7 @@ void BindingSet::inferTransitiveProtocolRequirements() {
   } while (!workList.empty());
 }
 
-void BindingSet::inferTransitiveBindings() {
-  using BindingKind = AllowedBindingKind;
-
+void BindingSet::inferTransitiveKeyPathBindings() {
   // If the current type variable represents a key path root type
   // let's try to transitively infer its type through bindings of
   // a key path type.
@@ -550,14 +548,18 @@ void BindingSet::inferTransitiveBindings() {
               }
             } else {
               addBinding(
-                  binding.withSameSource(inferredRootTy, BindingKind::Exact),
+                  binding.withSameSource(inferredRootTy, AllowedBindingKind::Exact),
                   /*isTransitive=*/true);
             }
           }
         }
       }
     }
   }
+}
+
+void BindingSet::inferTransitiveBindings() {
+  inferTransitiveKeyPathBindings();
 
   for (const auto &entry : Info.SupertypeOf) {
     auto &node = CS.getConstraintGraph()[entry.first];
@@ -608,8 +610,8 @@ void BindingSet::inferTransitiveBindings() {
       // either be Exact or Supertypes in order for it to make sense
       // to add Supertype bindings based on the relationship between
       // our type variables.
-      if (binding.Kind != BindingKind::Exact &&
-          binding.Kind != BindingKind::Supertypes)
+      if (binding.Kind != AllowedBindingKind::Exact &&
+          binding.Kind != AllowedBindingKind::Supertypes)
         continue;
 
       auto type = binding.BindingType;
@@ -620,7 +622,7 @@ void BindingSet::inferTransitiveBindings() {
       if (ConstraintSystem::typeVarOccursInType(TypeVar, type))
         continue;
 
-      addBinding(binding.withSameSource(type, BindingKind::Supertypes),
+      addBinding(binding.withSameSource(type, AllowedBindingKind::Supertypes),
                  /*isTransitive=*/true);
     }
   }