[CS] NFC: Factor out includingParentApply

Author: hamishknight

include/swift/Sema/ConstraintSystem.h

@@ -2826,6 +2826,10 @@ class ConstraintSystem {
   /// Associate an argument list with a call at a given locator.
   void associateArgumentList(ConstraintLocator *locator, ArgumentList *args);
 
+  /// If the given node is a function expression with a parent ApplyExpr,
+  /// returns the apply, otherwise returns the node itself.
+  ASTNode includingParentApply(ASTNode node);
+
   std::optional<SelectedOverload>
   findSelectedOverloadFor(ConstraintLocator *locator) const {
     auto result = ResolvedOverloads.find(locator);

lib/Sema/CSRanking.cpp

@@ -1036,18 +1036,9 @@ SolutionCompareResult ConstraintSystem::compareSolutions(
     if (cs.isForCodeCompletion()) {
       // Don't rank based on overload choices of function calls that contain the
       // code completion token.
-      ASTNode anchor = simplifyLocatorToAnchor(overload.locator);
-      if (auto expr = getAsExpr(anchor)) {
-        // If the anchor is a called function, also don't rank overload choices
-        // if any of the arguments contain the code completion token.
-        if (auto apply = dyn_cast_or_null<ApplyExpr>(cs.getParentExpr(expr))) {
-          if (apply->getFn() == expr) {
-            anchor = apply;
-          }
-        }
-      }
-      if (anchor && cs.containsIDEInspectionTarget(anchor)) {
-        continue;
+      if (auto anchor = simplifyLocatorToAnchor(overload.locator)) {
+        if (cs.containsIDEInspectionTarget(cs.includingParentApply(anchor)))
+          continue;
       }
     }
 

lib/Sema/ConstraintSystem.cpp

@@ -6658,6 +6658,16 @@ static bool shouldHaveDirectCalleeOverload(const CallExpr *callExpr) {
 }
 #endif
 
+ASTNode ConstraintSystem::includingParentApply(ASTNode node) {
+  if (auto *expr = getAsExpr(node)) {
+    if (auto apply = getAsExpr<ApplyExpr>(getParentExpr(expr))) {
+      if (apply->getFn() == expr)
+        return apply;
+    }
+  }
+  return node;
+}
+
 Type Solution::resolveInterfaceType(Type type) const {
   auto resolvedType = type.transform([&](Type type) -> Type {
     if (auto *tvt = type->getAs<TypeVariableType>()) {