[ConstraintSystem] NFC: Unify logic in isInvalidPartialApplication and isPartialApplicaiotn

Author: xedin

lib/Sema/ConstraintSystem.cpp

@@ -2426,6 +2426,27 @@ Type ConstraintSystem::getMemberReferenceTypeFromOpenedType(
   return type;
 }
 
+static unsigned getApplicationLevel(ConstraintSystem &CS, Type baseTy,
+                                    UnresolvedDotExpr *UDE) {
+  unsigned level = 0;
+
+  // If base is a metatype it would be ignored (unless this is an initializer
+  // call), but if it is some other type it means that we have a single
+  // application level already.
+  if (!baseTy->is<MetatypeType>())
+    ++level;
+
+  if (auto *call = dyn_cast_or_null<CallExpr>(CS.getParentExpr(UDE))) {
+    // Reference is applied only if it appears in a function position
+    // in the parent call expression - i.e. `x(...)` vs. `y(x)`,
+    // the latter doesn't have `x` applied.
+    if (UDE == call->getFn()->getSemanticsProvidingExpr())
+      level += 1;
+  }
+
+  return level;
+}
+
 bool ConstraintSystem::isPartialApplication(ConstraintLocator *locator) {
   // If this is a compiler synthesized implicit conversion, let's skip
   // the check because the base of `UDE` is not the base of the injected
@@ -2440,20 +2461,7 @@ bool ConstraintSystem::isPartialApplication(ConstraintLocator *locator) {
 
   auto baseTy =
       simplifyType(getType(UDE->getBase()))->getWithoutSpecifierType();
-
-  // If base is a metatype it would be ignored (unless this is an initializer
-  // call), but if it is some other type it means that we have a single
-  // application level already.
-  unsigned level = 0;
-  if (!baseTy->is<MetatypeType>())
-    ++level;
-
-  if (auto *call = dyn_cast_or_null<CallExpr>(getParentExpr(UDE))) {
-    if (UDE == call->getFn()->getSemanticsProvidingExpr())
-      level += 1;
-  }
-
-  return level < 2;
+  return getApplicationLevel(*this, baseTy, UDE) < 2;
 }
 
 DeclReferenceType
@@ -3088,18 +3096,7 @@ isInvalidPartialApplication(ConstraintSystem &cs,
   if (!isInvalidIfPartiallyApplied())
     return {false,0};
 
-  // If base is a metatype it would be ignored (unless this is an initializer
-  // call), but if it is some other type it means that we have a single
-  // application level already.
-  unsigned level = 0;
-  if (!baseTy->is<MetatypeType>())
-    ++level;
-
-  if (auto *call = dyn_cast_or_null<CallExpr>(cs.getParentExpr(UDE))) {
-    level += 1;
-  }
-
-  return {true, level};
+  return {true, getApplicationLevel(cs, baseTy, UDE)};
 }
 
 FunctionType::ExtInfo ConstraintSystem::closureEffects(ClosureExpr *expr) {