--- a/src/jdk.compiler/share/classes/com/sun/tools/javac/tree/JCTree.java	Mon Sep 09 11:43:16 2019 -0400
+++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/tree/JCTree.java	Wed Nov 27 09:00:01 2019 +0100
@@ -38,6 +38,7 @@
 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.comp.MatchBindingsComputer.BindingSymbol;
 import com.sun.tools.javac.util.*;
 import com.sun.tools.javac.util.DefinedBy.Api;
 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
@@ -238,6 +239,10 @@
          */
         TYPETEST,
 
+        /** Patterns.
+         */
+        BINDINGPATTERN,
+
         /** Indexed array expressions, of type Indexed.
          */
         INDEXED,
@@ -2135,10 +2140,10 @@
      */
     public static class JCInstanceOf extends JCExpression implements InstanceOfTree {
         public JCExpression expr;
-        public JCTree clazz;
-        protected JCInstanceOf(JCExpression expr, JCTree clazz) {
+        public JCTree pattern;
+        protected JCInstanceOf(JCExpression expr, JCTree pattern) {
             this.expr = expr;
-            this.clazz = clazz;
+            this.pattern = pattern;
         }
         @Override
         public void accept(Visitor v) { v.visitTypeTest(this); }
@@ -2146,7 +2151,13 @@
         @DefinedBy(Api.COMPILER_TREE)
         public Kind getKind() { return Kind.INSTANCE_OF; }
         @DefinedBy(Api.COMPILER_TREE)
-        public JCTree getType() { return clazz; }
+        public JCTree getType() { return pattern instanceof JCPattern ? pattern.hasTag(BINDINGPATTERN) ? ((JCBindingPattern) pattern).vartype : null : pattern; }
+
+        @Override @DefinedBy(Api.COMPILER_TREE)
+        public JCPattern getPattern() {
+            return pattern instanceof JCPattern ? (JCPattern) pattern : null;
+        }
+
         @DefinedBy(Api.COMPILER_TREE)
         public JCExpression getExpression() { return expr; }
         @Override @DefinedBy(Api.COMPILER_TREE)
@@ -2160,6 +2171,60 @@
     }
 
     /**
+     * Pattern matching forms.
+     */
+    public static abstract class JCPattern extends JCTree
+            implements PatternTree {
+        public JCExpression constExpression() {
+            return null;
+        }
+    }
+
+    public static class JCBindingPattern extends JCPattern
+            implements BindingPatternTree {
+        public Name name;
+        public BindingSymbol symbol;
+        public JCTree vartype;
+
+        protected JCBindingPattern(Name name, BindingSymbol symbol, JCTree vartype) {
+            this.name = name;
+            this.symbol = symbol;
+            this.vartype = vartype;
+        }
+
+        @DefinedBy(Api.COMPILER_TREE)
+        public Name getBinding() {
+            return name;
+        }
+
+        @Override @DefinedBy(Api.COMPILER_TREE)
+        public Tree getType() {
+            return vartype;
+        }
+
+        @Override
+        public void accept(Visitor v) {
+            v.visitBindingPattern(this);
+        }
+
+        @DefinedBy(Api.COMPILER_TREE)
+        public Kind getKind() {
+            return Kind.BINDING_PATTERN;
+        }
+
+        @Override
+        @DefinedBy(Api.COMPILER_TREE)
+        public <R, D> R accept(TreeVisitor<R, D> v, D d) {
+            return v.visitBindingPattern(this, d);
+        }
+
+        @Override
+        public Tag getTag() {
+            return BINDINGPATTERN;
+        }
+    }
+
+    /**
      * An array selection
      */
     public static class JCArrayAccess extends JCExpression implements ArrayAccessTree {
@@ -3133,6 +3198,7 @@
         JCBinary Binary(Tag opcode, JCExpression lhs, JCExpression rhs);
         JCTypeCast TypeCast(JCTree expr, JCExpression type);
         JCInstanceOf TypeTest(JCExpression expr, JCTree clazz);
+        JCBindingPattern BindingPattern(Name name, JCTree vartype);
         JCArrayAccess Indexed(JCExpression indexed, JCExpression index);
         JCFieldAccess Select(JCExpression selected, Name selector);
         JCIdent Ident(Name idname);
@@ -3197,6 +3263,7 @@
         public void visitBinary(JCBinary that)               { visitTree(that); }
         public void visitTypeCast(JCTypeCast that)           { visitTree(that); }
         public void visitTypeTest(JCInstanceOf that)         { visitTree(that); }
+        public void visitBindingPattern(JCBindingPattern that) { visitTree(that); }
         public void visitIndexed(JCArrayAccess that)         { visitTree(that); }
         public void visitSelect(JCFieldAccess that)          { visitTree(that); }
         public void visitReference(JCMemberReference that)   { visitTree(that); }