8324651: Compiler Implementation for Derived Record Creation (Preview)

src/java.base/share/classes/jdk/internal/javac/PreviewFeature.java

@@ -81,6 +81,8 @@ public enum Feature {
         CLASSFILE_API,
         @JEP(number=461, title="Stream Gatherers", status="Preview")
         STREAM_GATHERERS,
+        @JEP(number=468, title="Derived Record Creation", status="Preview")
+        DERIVED_RECORD_CREATION,
         LANGUAGE_MODEL,
         /**
          * A key for testing.

src/java.compiler/share/classes/javax/lang/model/element/ElementKind.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2005, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -25,6 +25,8 @@
 
 package javax.lang.model.element;
 
+import jdk.internal.javac.PreviewFeature;
+
 /**
  * The {@code kind} of an element.
  *
@@ -121,7 +123,14 @@ public enum ElementKind {
      * A binding variable in a pattern.
      * @since 16
      */
-    BINDING_VARIABLE;
+    BINDING_VARIABLE,
+
+    /**
+     * A local component variable in a derived record creation expression.
+     * @since 23
+     */
+    @PreviewFeature(feature=PreviewFeature.Feature.DERIVED_RECORD_CREATION, reflective=true)
+    COMPONENT_LOCAL_VARIABLE;
 
     // Maintenance note: check if the default implementation of
     // Elements.getOutermostTypeElement needs updating when new kind
@@ -200,7 +209,8 @@ public boolean isInitializer() {
      * Returns {@code true} if this is a kind of variable: including
      * {@code ENUM_CONSTANT}, {@code FIELD}, {@code PARAMETER},
      * {@code LOCAL_VARIABLE}, {@code EXCEPTION_PARAMETER},
-     * {@code RESOURCE_VARIABLE}, and {@code BINDING_VARIABLE}.
+     * {@code RESOURCE_VARIABLE}, {@code BINDING_VARIABLE}, and
+     * {@code COMPONENT_LOCAL_VARIABLE}.
      *
      * @return {@code true} if this is a kind of variable
      * @since 19
@@ -209,7 +219,7 @@ public boolean isVariable() {
         return switch(this) {
         case ENUM_CONSTANT, FIELD, PARAMETER,
              LOCAL_VARIABLE, EXCEPTION_PARAMETER, RESOURCE_VARIABLE,
-             BINDING_VARIABLE -> true;
+             BINDING_VARIABLE, COMPONENT_LOCAL_VARIABLE -> true;
         default -> false;
         };
     }

src/java.compiler/share/classes/javax/lang/model/util/ElementKindVisitor6.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2005, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -25,6 +25,8 @@
 
 package javax.lang.model.util;
 
+import jdk.internal.javac.PreviewFeature;
+
 import javax.lang.model.element.*;
 import javax.annotation.processing.SupportedSourceVersion;
 import javax.lang.model.SourceVersion;
@@ -264,6 +266,9 @@ public R visitVariable(VariableElement e, P p) {
         case BINDING_VARIABLE:
             return visitVariableAsBindingVariable(e, p);
 
+        case COMPONENT_LOCAL_VARIABLE:
+            return visitVariableAsComponentLocalVariable(e, p);
+
         default:
             throw new AssertionError("Bad kind " + k + " for VariableElement" + e);
         }
@@ -364,6 +369,22 @@ public R visitVariableAsBindingVariable(VariableElement e, P p) {
         return visitUnknown(e, p);
     }
 
+    /**
+     * Visits a {@code COMPONENT_LOCAL_VARIABLE} variable element.
+     *
+     * @implSpec This implementation calls {@code visitUnknown}.
+     *
+     * @param e the element to visit
+     * @param p a visitor-specified parameter
+     * @return  the result of {@code visitUnknown}
+     *
+     * @since 23
+     */
+    @PreviewFeature(feature=PreviewFeature.Feature.DERIVED_RECORD_CREATION, reflective=true)
+    public R visitVariableAsComponentLocalVariable(VariableElement e, P p) {
+        return visitUnknown(e, p);
+    }
+
     /**
      * {@inheritDoc ElementVisitor}
      *

src/java.compiler/share/classes/javax/lang/model/util/ElementKindVisitorPreview.java

@@ -86,4 +86,21 @@ protected ElementKindVisitorPreview() {
     protected ElementKindVisitorPreview(R defaultValue) {
         super(defaultValue);
     }
+
+    /**
+     * {@inheritDoc ElementKindVisitor6}
+     *
+     * @implSpec This implementation calls {@code defaultAction}.
+     *
+     * @param e {@inheritDoc ElementKindVisitor6}
+     * @param p {@inheritDoc ElementKindVisitor6}
+     * @return  the result of {@code defaultAction}
+     *
+     * @since 23
+     */
+    @Override
+    @PreviewFeature(feature=PreviewFeature.Feature.DERIVED_RECORD_CREATION, reflective=true)
+    public R visitVariableAsComponentLocalVariable(VariableElement e, P p) {
+        return defaultAction(e, p);
+    }
 }

src/jdk.compiler/share/classes/com/sun/source/tree/DerivedInstanceTree.java

@@ -0,0 +1,53 @@
+/*
+ * Copyright (c) 2024, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package com.sun.source.tree;
+
+import jdk.internal.javac.PreviewFeature;
+
+/**
+ * A tree node for a derived record creation expression.
+ *
+ * For example:
+ * <pre>
+ *   <em>expression</em> with { <em>assignments</em> }
+ * </pre>
+ *
+ * @jls 15.30 Derived Record Creation Expression
+ *
+ * @since 23
+ */
+@PreviewFeature(feature=PreviewFeature.Feature.DERIVED_RECORD_CREATION, reflective=true)
+public interface DerivedInstanceTree extends ExpressionTree {
+    /**
+     * {@return the origin expression of the derived record creation expression.}
+     */
+    ExpressionTree getExpression();
+
+    /**
+     * {@return the reconstruction block.}
+     */
+    BlockTree getBlock();
+}

src/jdk.compiler/share/classes/com/sun/source/tree/Tree.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2005, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -228,6 +228,13 @@ public enum Kind {
          */
         PARENTHESIZED(ParenthesizedTree.class),
 
+        /**
+         * Used for instances of {@link DerivedInstanceTree}.
+         * @since 23
+         */
+        @PreviewFeature(feature=PreviewFeature.Feature.DERIVED_RECORD_CREATION, reflective=true)
+        DERIVED_INSTANCE(DerivedInstanceTree.class),
+
         /**
          * Used for instances of {@link BindingPatternTree}.
          *

src/jdk.compiler/share/classes/com/sun/source/tree/TreeVisitor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2005, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -379,6 +379,16 @@ public interface TreeVisitor<R,P> {
      */
     R visitParenthesized(ParenthesizedTree node, P p);
 
+    /**
+     * Visits a {@code DerivedInstanceTree} node.
+     * @param node the node being visited
+     * @param p a parameter value
+     * @return a result value
+     * @since 23
+     */
+    @PreviewFeature(feature=PreviewFeature.Feature.DERIVED_RECORD_CREATION, reflective=true)
+    R visitDerivedInstance(DerivedInstanceTree node, P p);
+
     /**
      * Visits a {@code ReturnTree} node.
      * @param node the node being visited

src/jdk.compiler/share/classes/com/sun/source/util/SimpleTreeVisitor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2005, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -544,6 +544,22 @@ public R visitParenthesized(ParenthesizedTree node, P p) {
         return defaultAction(node, p);
     }
 
+    /**
+     * {@inheritDoc}
+     *
+     * @implSpec This implementation calls {@code defaultAction}.
+     *
+     * @param node {@inheritDoc}
+     * @param p {@inheritDoc}
+     * @return  the result of {@code defaultAction}
+     * @since 23
+     */
+    @Override
+    @PreviewFeature(feature=PreviewFeature.Feature.DERIVED_RECORD_CREATION, reflective=true)
+    public R visitDerivedInstance(DerivedInstanceTree node, P p) {
+        return defaultAction(node, p);
+    }
+
     /**
      * {@inheritDoc}
      *

src/jdk.compiler/share/classes/com/sun/source/util/TreeScanner.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2005, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -662,6 +662,24 @@ public R visitParenthesized(ParenthesizedTree node, P p) {
         return scan(node.getExpression(), p);
     }
 
+    /**
+     * {@inheritDoc}
+     *
+     * @implSpec This implementation scans the children in left to right order.
+     *
+     * @param node  {@inheritDoc}
+     * @param p  {@inheritDoc}
+     * @return the result of scanning
+     * @since 23
+     */
+    @Override
+    @PreviewFeature(feature=PreviewFeature.Feature.DERIVED_RECORD_CREATION, reflective=true)
+    public R visitDerivedInstance(DerivedInstanceTree node, P p) {
+        R r = scan(node.getExpression(), p);
+        r = scanAndReduce(node.getBlock(), p, r);
+        return r;
+    }
+
     /**
      * {@inheritDoc}
      *

src/jdk.compiler/share/classes/com/sun/tools/javac/code/Flags.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -389,6 +389,11 @@ public static EnumSet<Flag> asFlagSet(long flags) {
      */
     public static final long SEALED = 1L<<62; // ClassSymbols
 
+    /**
+     * Flag to indicate component local variables.
+     */
+    public static final long COMPONENT_LOCAL_VARIABLE = 1L<<62; // VarSymbols
+
     /**
      * Flag to indicate restricted method declaration.
      */

src/jdk.compiler/share/classes/com/sun/tools/javac/code/Preview.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -210,6 +210,7 @@ public boolean isPreview(Feature feature) {
             case STRING_TEMPLATES -> true;
             case IMPLICIT_CLASSES -> true;
             case SUPER_INIT -> true;
+            case DERIVED_INSTANCE -> true;
             case PRIMITIVE_PATTERNS -> true;
             //Note: this is a backdoor which allows to optionally treat all features as 'preview' (for testing).
             //When real preview features will be added, this method can be implemented to return 'true'

src/jdk.compiler/share/classes/com/sun/tools/javac/code/Source.java

@@ -256,6 +256,7 @@ public enum Feature {
         UNNAMED_VARIABLES(JDK22, Fragments.FeatureUnnamedVariables, DiagKind.PLURAL),
         PRIMITIVE_PATTERNS(JDK23, Fragments.FeaturePrimitivePatterns, DiagKind.PLURAL),
         SUPER_INIT(JDK22, Fragments.FeatureSuperInit, DiagKind.NORMAL),
+        DERIVED_INSTANCE(JDK23, Fragments.FeatureDerivedInstance, DiagKind.NORMAL),
         ;
 
         enum DiagKind {

src/jdk.compiler/share/classes/com/sun/tools/javac/code/Symbol.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -1763,6 +1763,9 @@ public ElementKind getKind() {
             } else if ((flags & MATCH_BINDING) != 0) {
                 ElementKind kind = ElementKind.BINDING_VARIABLE;
                 return kind;
+            } else if ((flags & COMPONENT_LOCAL_VARIABLE) != 0) {
+                ElementKind kind = ElementKind.COMPONENT_LOCAL_VARIABLE;
+                return kind;
             } else {
                 return ElementKind.LOCAL_VARIABLE;
             }