src/jdk.compiler/share/classes/com/sun/tools/javac/tree/JCTree.java

@@ -36,10 +36,11 @@
  import com.sun.source.tree.*;
  import com.sun.tools.javac.code.*;
  import com.sun.tools.javac.code.Directive.RequiresDirective;
  import com.sun.tools.javac.code.Scope.*;
  import com.sun.tools.javac.code.Symbol.*;
+ import com.sun.tools.javac.code.Type.MethodType;
  import com.sun.tools.javac.util.*;
  import com.sun.tools.javac.util.DefinedBy.Api;
  import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
  import com.sun.tools.javac.util.List;
  

@@ -751,23 +752,35 @@
      }
  
      /**
       * Common supertype for all functional expression trees (lambda and method references)
       */
-     public abstract static class JCFunctionalExpression extends JCPolyExpression {
+     public abstract static sealed class JCFunctionalExpression extends JCPolyExpression
+                                                                permits JCLambda, JCMemberReference {
  
          public JCFunctionalExpression() {
              //a functional expression is always a 'true' poly
              polyKind = PolyKind.POLY;
          }
  
          /** list of target types inferred for this functional expression. */
          public Type target;
+         /** code reflection specific metadata. */
+         public CodeReflectionInfo codeReflectionInfo;
  
          public Type getDescriptorType(Types types) {
-             return target != null ? types.findDescriptorType(target) : types.createErrorType(null);
+             if (target == null) {
+                 return types.createErrorType(null);
+             } else if (target.hasTag(TypeTag.METHOD)) {
+                 // this is a quoted expression
+                 return target;
+             } else {
+                 return types.findDescriptorType(target);
+             }
          }
+ 
+         public record CodeReflectionInfo(Symbol quotedField, List<JCExpression> capturedArgs) { }
      }
  
      /**
       * A class definition.
       */

@@ -1955,11 +1968,11 @@
      }
  
      /**
       * A lambda expression.
       */
-     public static class JCLambda extends JCFunctionalExpression implements LambdaExpressionTree {
+     public static final class JCLambda extends JCFunctionalExpression implements LambdaExpressionTree {
  
          public enum ParameterKind {
              IMPLICIT,
              EXPLICIT
          }

@@ -2541,11 +2554,11 @@
      }
  
      /**
       * Selects a member expression.
       */
-     public static class JCMemberReference extends JCFunctionalExpression implements MemberReferenceTree {
+     public static non-sealed class JCMemberReference extends JCFunctionalExpression implements MemberReferenceTree {
  
          public ReferenceMode mode;
          public ReferenceKind kind;
          public Name name;
          public JCExpression expr;