Merge branch 'master' into issue4903-unnecessaryboxing

2024-05-23 20:15:47 +02:00
commit f1fc7aacbe
@@ -7071,7 +7071,8 @@
      "avatar_url": "https://avatars.githubusercontent.com/u/26581168?v=4",
      "profile": "https://github.com/mluckam",
      "contributions": [
-        "code"
+        "code",
+        "bug"
      ]
    },
    {
@@ -7534,6 +7535,52 @@
      "contributions": [
        "bug"
      ]
+    },
+    {
+      "login": "cowwoc",
+      "name": "Gili Tzabari",
+      "avatar_url": "https://avatars.githubusercontent.com/u/633348?v=4",
+      "profile": "https://github.com/cowwoc",
+      "contributions": [
+        "bug"
+      ]
+    },
+    {
+      "login": "bobalicious",
+      "name": "Rob Baillie",
+      "avatar_url": "https://avatars.githubusercontent.com/u/6523911?v=4",
+      "profile": "http://robertbaillie.blogspot.co.uk/",
+      "contributions": [
+        "bug"
+      ]
+    },
+    {
+      "login": "mdagcilar",
+      "name": "Metin Dagcilar",
+      "avatar_url": "https://avatars.githubusercontent.com/u/6627550?v=4",
+      "profile": "https://github.com/mdagcilar",
+      "contributions": [
+        "bug"
+      ]
+    },
+    {
+      "login": "kesslerj",
+      "name": "Jonas Keßler",
+      "avatar_url": "https://avatars.githubusercontent.com/u/25590499?v=4",
+      "profile": "https://github.com/kesslerj",
+      "contributions": [
+        "bug"
+      ]
+    },
+    {
+      "login": "Gold856",
+      "name": "Gold856",
+      "avatar_url": "https://avatars.githubusercontent.com/u/117957790?v=4",
+      "profile": "https://github.com/Gold856",
+      "contributions": [
+        "bug",
+        "code"
+      ]
    }
  ],
  "contributorsPerLine": 7,
@@ -4,7 +4,7 @@ GEM
    addressable (2.8.6)
      public_suffix (>= 2.0.2, < 6.0)
    base64 (0.2.0)
-    bigdecimal (3.1.6)
+    bigdecimal (3.1.8)
    claide (1.1.0)
    claide-plugins (0.9.2)
      cork
@@ -28,7 +28,7 @@ GEM
      octokit (>= 4.0)
      terminal-table (>= 1, < 4)
    differ (0.1.2)
-    et-orbi (1.2.8)
+    et-orbi (1.2.11)
      tzinfo
    faraday (2.9.0)
      faraday-net_http (>= 2.0, < 3.2)
@@ -36,8 +36,8 @@ GEM
      faraday (>= 0.8)
    faraday-net_http (3.1.0)
      net-http
-    fugit (1.10.1)
-      et-orbi (~> 1, >= 1.2.7)
+    fugit (1.11.0)
+      et-orbi (~> 1, >= 1.2.11)
      raabro (~> 1.4)
    git (1.19.1)
      addressable (~> 2.8)
@@ -46,13 +46,13 @@ GEM
      rexml
    kramdown-parser-gfm (1.1.0)
      kramdown (~> 2.0)
-    liquid (5.4.0)
+    liquid (5.5.0)
    logger-colors (1.0.0)
    nap (1.1.0)
    net-http (0.4.1)
      uri
    no_proxy_fix (0.1.2)
-    nokogiri (1.16.2-x86_64-linux)
+    nokogiri (1.16.5-x86_64-linux)
      racc (~> 1.4)
    octokit (8.1.0)
      base64
@@ -66,12 +66,13 @@ GEM
      nokogiri (~> 1.13)
      rufus-scheduler (~> 3.8)
      slop (~> 4.9)
-    public_suffix (5.0.4)
+    public_suffix (5.0.5)
    raabro (1.4.0)
-    racc (1.7.3)
+    racc (1.8.0)
    rchardet (1.8.0)
-    rexml (3.2.6)
-    rouge (4.2.0)
+    rexml (3.2.8)
+      strscan (>= 3.0.9)
+    rouge (4.2.1)
    rufus-scheduler (3.9.1)
      fugit (~> 1.1, >= 1.1.6)
    safe_yaml (1.0.5)
@@ -79,6 +80,7 @@ GEM
      addressable (>= 2.3.5)
      faraday (>= 0.17.3, < 3)
    slop (4.10.1)
+    strscan (3.1.0)
    terminal-table (3.0.2)
      unicode-display_width (>= 1.1.1, < 3)
    tzinfo (2.0.6)
@@ -1,7 +1,7 @@
 GEM
  remote: https://rubygems.org/
  specs:
-    activesupport (7.1.3.2)
+    activesupport (7.1.3.3)
      base64
      bigdecimal
      concurrent-ruby (~> 1.0, >= 1.0.2)
@@ -14,7 +14,7 @@ GEM
    addressable (2.8.6)
      public_suffix (>= 2.0.2, < 6.0)
    base64 (0.2.0)
-    bigdecimal (3.1.6)
+    bigdecimal (3.1.8)
    coffee-script (2.4.1)
      coffee-script-source
      execjs
@@ -23,8 +23,8 @@ GEM
    commonmarker (0.23.10)
    concurrent-ruby (1.2.3)
    connection_pool (2.4.1)
-    csv (3.2.8)
-    dnsruby (1.71.0)
+    csv (3.3.0)
+    dnsruby (1.72.1)
      simpleidn (~> 0.2.1)
    drb (2.2.1)
    em-websocket (0.5.3)
@@ -96,7 +96,7 @@ GEM
      activesupport (>= 2)
      nokogiri (>= 1.4)
    http_parser.rb (0.8.0)
-    i18n (1.14.4)
+    i18n (1.14.5)
      concurrent-ruby (~> 1.0)
    jekyll (3.9.5)
      addressable (~> 2.4)
@@ -219,23 +219,24 @@ GEM
      jekyll (>= 3.5, < 5.0)
      jekyll-feed (~> 0.9)
      jekyll-seo-tag (~> 2.1)
-    minitest (5.22.2)
+    minitest (5.23.1)
    mutex_m (0.2.0)
    net-http (0.4.1)
      uri
-    nokogiri (1.16.2-x86_64-linux)
+    nokogiri (1.16.5-x86_64-linux)
      racc (~> 1.4)
    octokit (4.25.1)
      faraday (>= 1, < 3)
      sawyer (~> 0.9)
    pathutil (0.16.2)
      forwardable-extended (~> 2.6)
-    public_suffix (5.0.4)
-    racc (1.7.3)
+    public_suffix (5.0.5)
+    racc (1.8.0)
    rb-fsevent (0.11.2)
-    rb-inotify (0.10.1)
+    rb-inotify (0.11.1)
      ffi (~> 1.0)
-    rexml (3.2.6)
+    rexml (3.2.8)
+      strscan (>= 3.0.9)
    rouge (3.30.0)
    rubyzip (2.3.2)
    safe_yaml (1.0.5)
@@ -247,17 +248,14 @@ GEM
    sawyer (0.9.2)
      addressable (>= 2.3.5)
      faraday (>= 0.17.3, < 3)
-    simpleidn (0.2.1)
-      unf (~> 0.1.4)
+    simpleidn (0.2.3)
+    strscan (3.1.0)
    terminal-table (1.8.0)
      unicode-display_width (~> 1.1, >= 1.1.1)
    typhoeus (1.4.1)
      ethon (>= 0.9.0)
    tzinfo (2.0.6)
      concurrent-ruby (~> 1.0)
-    unf (0.1.4)
-      unf_ext
-    unf_ext (0.0.9.1)
    unicode-display_width (1.8.0)
    uri (0.13.0)
    webrick (1.8.1)
@@ -24,6 +24,11 @@ Since this release, PMD will also expose any getter returning a collection of an
 /UserClass[@InterfaceNames = 'Queueable']
 ```

+#### Updated PMD Designer
+
+This PMD release ships a new version of the pmd-designer.
+For the changes, see [PMD Designer Changelog (7.2.0)](https://github.com/pmd/pmd-designer/releases/tag/7.2.0).
+
 ### 🐛 Fixed Issues
 * core
  * [#4467](https://github.com/pmd/pmd/issues/4467): \[core] Expose collections from getters as XPath sequence attributes
@@ -34,6 +39,9 @@ Since this release, PMD will also expose any getter returning a collection of an
  * [#4973](https://github.com/pmd/pmd/pull/4973): \[java] Stop parsing Java for CPD
  * [#4980](https://github.com/pmd/pmd/issues/4980): \[java] Bad intersection, unrelated class types java.lang.Object\[] and java.lang.Number
  * [#4988](https://github.com/pmd/pmd/pull/4988): \[java] Fix impl of ASTVariableId::isResourceDeclaration / VariableId/@<!-- -->ResourceDeclaration
+  * [#4990](https://github.com/pmd/pmd/issues/4990): \[java] Add an attribute @<!-- -->PackageQualifier to ASTClassType
+  * [#5006](https://github.com/pmd/pmd/issues/5006): \[java] Bad intersection, unrelated class types Child and Parent<? extends Child>
+  * [#5029](https://github.com/pmd/pmd/issues/5029): \[java] PMD 7.x throws stack overflow in TypeOps$ProjectionVisitor while parsing a Java class
 * java-bestpractices
  * [#4278](https://github.com/pmd/pmd/issues/4278): \[java] UnusedPrivateMethod FP with Junit 5 @MethodSource and default factory method name
  * [#4852](https://github.com/pmd/pmd/issues/4852): \[java] ReplaceVectorWithList false-positive (neither Vector nor List usage) 
@@ -41,6 +49,13 @@ Since this release, PMD will also expose any getter returning a collection of an
  * [#4985](https://github.com/pmd/pmd/issues/4985): \[java] UnusedPrivateMethod false-positive / method reference in combination with custom object
 * java-codestyle
  * [#4930](https://github.com/pmd/pmd/issues/4930): \[java] EmptyControlStatement should not allow empty try with concise resources
+  * [#4954](https://github.com/pmd/pmd/issues/4954): \[java] LocalVariableNamingConventions should allow unnamed variables by default
+  * [#5028](https://github.com/pmd/pmd/issues/5028): \[java] FormalParameterNamingConventions should accept unnamed parameters by default
+* java-errorprone
+  * [#4042](https://github.com/pmd/pmd/issues/4042): \[java] A false negative about the rule StringBufferInstantiationWithChar
+  * [#5007](https://github.com/pmd/pmd/issues/5007): \[java] AvoidUsingOctalValues triggers on non-octal double literals with a leading 0
+* java-multithreading
+  * [#2368](https://github.com/pmd/pmd/issues/2368): \[java] False positive UnsynchronizedStaticFormatter in static initializer

 ### 🚨 API Changes

@@ -51,5 +66,7 @@ Since this release, PMD will also expose any getter returning a collection of an

 ### ✨ External Contributions

+* [#5020](https://github.com/pmd/pmd/issues/5020): \[java] Fix AvoidUsingOctalValues false-positive - [Gold856](https://github.com/Gold856) (@Gold856)
+
 {% endtocmaker %}

@@ -101,6 +101,11 @@ public final class StreamImpl {
                }
            }

+            @Override
+            public List<Node> toList() {
+                return Collections.unmodifiableList(Arrays.asList(array));
+            }
+
            @Override
            protected Iterator<Node> baseIterator() {
                return Arrays.asList(array).iterator();
@@ -21,7 +21,7 @@ import net.sourceforge.pmd.lang.java.types.JClassType;
 *
 * </pre>
 */
-public final class ASTAnnotation extends AbstractJavaTypeNode implements TypeNode, ASTMemberValue, Iterable<ASTMemberValuePair> {
+public final class ASTAnnotation extends AbstractJavaTypeNode implements ASTMemberValue, Iterable<ASTMemberValuePair> {

    ASTAnnotation(int id) {
        super(id);
@@ -17,7 +17,7 @@ package net.sourceforge.pmd.lang.java.ast;
 *
 * </pre>
 */
-public final class ASTArrayDimExpr extends ASTArrayTypeDim implements Annotatable {
+public final class ASTArrayDimExpr extends ASTArrayTypeDim {

    ASTArrayDimExpr(int id) {
        super(id);
@@ -22,7 +22,7 @@ import java.util.Iterator;
 * </pre>
 *
 */
-public final class ASTArrayInitializer extends AbstractJavaExpr implements ASTExpression, Iterable<ASTExpression> {
+public final class ASTArrayInitializer extends AbstractJavaExpr implements Iterable<ASTExpression> {

    ASTArrayInitializer(int id) {
        super(id);
@@ -6,7 +6,6 @@ package net.sourceforge.pmd.lang.java.ast;

 import net.sourceforge.pmd.lang.ast.impl.javacc.JavaccToken;
 import net.sourceforge.pmd.lang.java.ast.ASTList.ASTMaybeEmptyListOf;
-import net.sourceforge.pmd.lang.java.ast.InternalInterfaces.AllChildrenAreOfType;

 /**
 * A block of code. This is a {@linkplain ASTStatement statement} that
@@ -19,7 +18,7 @@ import net.sourceforge.pmd.lang.java.ast.InternalInterfaces.AllChildrenAreOfType
 * </pre>
 */
 public final class ASTBlock extends ASTMaybeEmptyListOf<ASTStatement>
-        implements ASTSwitchArrowRHS, ASTStatement, AllChildrenAreOfType<ASTStatement> {
+        implements ASTSwitchArrowRHS, ASTStatement {

    ASTBlock(int id) {
        super(id, ASTStatement.class);
@@ -9,7 +9,7 @@ import org.checkerframework.checker.nullness.qual.NonNull;
 /**
 * The boolean literal, either "true" or "false".
 */
-public final class ASTBooleanLiteral extends AbstractLiteral implements ASTLiteral {
+public final class ASTBooleanLiteral extends AbstractLiteral {

    private boolean isTrue;

@@ -14,7 +14,7 @@ package net.sourceforge.pmd.lang.java.ast;
 *
 * </pre>
 */
-public final class ASTCastExpression extends AbstractJavaExpr implements ASTExpression {
+public final class ASTCastExpression extends AbstractJavaExpr {

    ASTCastExpression(int id) {
        super(id);
@@ -15,7 +15,7 @@ import net.sourceforge.pmd.lang.document.Chars;
 * retrieve the actual runtime value. Use {@link #getLiteralText()} to
 * retrieve the text.
 */
-public final class ASTCharLiteral extends AbstractLiteral implements ASTLiteral {
+public final class ASTCharLiteral extends AbstractLiteral {


    ASTCharLiteral(int id) {
@@ -7,6 +7,7 @@ package net.sourceforge.pmd.lang.java.ast;
 import org.checkerframework.checker.nullness.qual.Nullable;

 import net.sourceforge.pmd.lang.ast.impl.javacc.JavaccToken;
+import net.sourceforge.pmd.lang.java.symbols.JClassSymbol;
 import net.sourceforge.pmd.lang.java.symbols.JTypeDeclSymbol;
 import net.sourceforge.pmd.lang.java.types.JClassType;
 import net.sourceforge.pmd.util.AssertionUtil;
@@ -125,6 +126,32 @@ public final class ASTClassType extends AbstractJavaTypeNode implements ASTRefer
    }


+    /**
+     * Return the package qualifier, if this is a fully qualified name.
+     * Note that this will only be the case if we could resolve the
+     * qualifier to a package name during disambiguation. In other words,
+     * if the auxclasspath is not complete, and the qualifier could not
+     * be disambiguated, this method will return null (and an AmbiguousName
+     * will stay in the tree).
+     *
+     * <p>If a nested type is package-qualified, this method
+     * will only return a non-null result for the leftmost (=innermost)
+     * ASTClassType node. For instance in {@code java.util.Map.Entry},
+     * the node {@code java.util.Map} has package qualifier
+     * {@code "java.util"}, while the node for {@code Entry}
+     * has package qualifier {@code null}. Note that the
+     * {@linkplain JClassSymbol#getPackageName() package name}
+     * of the symbol and type mirror will reflect that package
+     * name anyway, on both nodes.
+     */
+    public @Nullable String getPackageQualifier() {
+        if (isFullyQualified()) {
+            assert symbol != null : "Symbol should be non-null if isFullyQualified returns true";
+            return symbol.getPackageName();
+        }
+        return null;
+    }
+
    @Override
    protected <P, R> R acceptVisitor(JavaVisitor<? super P, ? extends R> visitor, P data) {
        return visitor.visit(this, data);
@@ -13,7 +13,6 @@ import net.sourceforge.pmd.annotation.Experimental;
 import net.sourceforge.pmd.lang.ast.AstInfo;
 import net.sourceforge.pmd.lang.ast.NodeStream;
 import net.sourceforge.pmd.lang.ast.RootNode;
-import net.sourceforge.pmd.lang.ast.impl.GenericNode;
 import net.sourceforge.pmd.lang.java.symbols.table.JSymbolTable;
 import net.sourceforge.pmd.lang.java.types.TypeSystem;
 import net.sourceforge.pmd.lang.java.types.ast.internal.LazyTypeResolver;
@@ -49,7 +48,7 @@ import net.sourceforge.pmd.lang.rule.xpath.NoAttribute;
 * @see <a href="https://openjdk.org/jeps/445">JEP 445: Unnamed Classes and Instance Main Methods (Preview)</a> (Java 21)
 * @see #isUnnamedClass()
 */
-public final class ASTCompilationUnit extends AbstractJavaNode implements JavaNode, GenericNode<JavaNode>, RootNode {
+public final class ASTCompilationUnit extends AbstractJavaNode implements RootNode {

    private LazyTypeResolver lazyTypeResolver;
    private List<JavaComment> comments;
@@ -22,11 +22,7 @@ import org.checkerframework.checker.nullness.qual.Nullable;
 *
 * </pre>
 */
-public final class ASTConstructorCall extends AbstractInvocationExpr
-    implements ASTPrimaryExpression,
-               QualifiableExpression,
-               LeftRecursiveNode,
-               InvocationNode {
+public final class ASTConstructorCall extends AbstractInvocationExpr implements QualifiableExpression, LeftRecursiveNode {

    ASTConstructorCall(int id) {
        super(id);
@@ -19,9 +19,8 @@ import net.sourceforge.pmd.lang.java.types.OverloadSelectionResult;
 * </pre>
 */
 public final class ASTEnumConstant extends AbstractJavaTypeNode
-    implements Annotatable,
-               InvocationNode,
-        ModifierOwner,
+    implements InvocationNode,
+               ModifierOwner,
               ASTBodyDeclaration,
               InternalInterfaces.VariableIdOwner,
               JavadocCommentOwner {
@@ -7,7 +7,6 @@ package net.sourceforge.pmd.lang.java.ast;
 import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;

-import net.sourceforge.pmd.lang.ast.impl.GenericNode;
 import net.sourceforge.pmd.lang.java.symbols.JExecutableSymbol;
 import net.sourceforge.pmd.lang.java.types.JClassType;
 import net.sourceforge.pmd.lang.java.types.JMethodSig;
@@ -32,7 +31,6 @@ public interface ASTExecutableDeclaration
    extends ModifierOwner,
            ASTBodyDeclaration,
            TypeParamOwnerNode,
-            GenericNode<JavaNode>,
            JavadocCommentOwner {


@@ -39,11 +39,7 @@ import net.sourceforge.pmd.lang.java.types.ast.ExprContext;
 *
 * </pre>
 */
-public interface ASTExpression
-    extends JavaNode,
-            TypeNode,
-            ASTMemberValue,
-            ASTSwitchArrowRHS {
+public interface ASTExpression extends TypeNode, ASTMemberValue, ASTSwitchArrowRHS {

    /**
     * Always returns true. This is to allow XPath queries
@@ -22,9 +22,7 @@ import net.sourceforge.pmd.lang.rule.xpath.DeprecatedAttribute;
 * </pre>
 */
 public final class ASTFieldDeclaration extends AbstractJavaNode
-    implements Iterable<ASTVariableId>,
-               LeftRecursiveNode,
-        ModifierOwner,
+    implements LeftRecursiveNode,
               ASTBodyDeclaration,
               InternalInterfaces.MultiVariableIdOwner,
               JavadocCommentOwner {
@@ -25,10 +25,7 @@ import net.sourceforge.pmd.lang.java.types.TypingContext;
 * </pre>
 */
 public final class ASTFormalParameter extends AbstractJavaNode
-    implements ModifierOwner,
-               TypeNode,
-               Annotatable,
-               VariableIdOwner {
+    implements ModifierOwner, TypeNode, VariableIdOwner {

    ASTFormalParameter(int id) {
        super(id);
@@ -25,9 +25,7 @@ import net.sourceforge.pmd.lang.document.FileLocation;
 */
 // TODO extend AbstractStatement
 public final class ASTLocalVariableDeclaration extends AbstractJavaNode
-    implements Iterable<ASTVariableId>,
-               ASTStatement,
-        ModifierOwner,
+    implements ASTStatement,
               LeftRecursiveNode, // ModifierList is parsed separately in BlockStatement
               InternalInterfaces.MultiVariableIdOwner {

@@ -19,11 +19,7 @@ import org.checkerframework.checker.nullness.qual.Nullable;
 *
 * </pre>
 */
-public final class ASTMethodCall extends AbstractInvocationExpr
-    implements ASTPrimaryExpression,
-               QualifiableExpression,
-               InvocationNode,
-               MethodUsage {
+public final class ASTMethodCall extends AbstractInvocationExpr implements QualifiableExpression {

    ASTMethodCall(int id) {
        super(id);
@@ -23,8 +23,7 @@ import net.sourceforge.pmd.lang.java.types.TypeSystem;
 * </pre>
 */
 public final class ASTMethodReference extends AbstractJavaExpr
-    implements ASTPrimaryExpression,
-               QualifiableExpression,
+    implements QualifiableExpression,
               LeftRecursiveNode,
               MethodUsage,
               FunctionalExpression {
@@ -15,7 +15,7 @@ import org.checkerframework.checker.nullness.qual.Nullable;
 *
 * </pre>
 */
-public final class ASTNullLiteral extends AbstractLiteral implements ASTLiteral {
+public final class ASTNullLiteral extends AbstractLiteral {
    ASTNullLiteral(int id) {
        super(id);
    }
@@ -14,7 +14,7 @@ import net.sourceforge.pmd.lang.java.types.JPrimitiveType;
 /**
 * A numeric literal of any type (double, int, long, float, etc).
 */
-public final class ASTNumericLiteral extends AbstractLiteral implements ASTLiteral {
+public final class ASTNumericLiteral extends AbstractLiteral {

    /**
     * True if this is an integral literal, ie int OR long,
@@ -120,10 +120,10 @@ public final class ASTNumericLiteral extends AbstractLiteral implements ASTLiter
     * for the literal {@code 0} (which can really be any base).
     */
    public int getBase() {
-        return getBase(getLiteralText());
+        return getBase(getLiteralText(), isIntegral());
    }

-    static int getBase(Chars image) {
+    static int getBase(Chars image, boolean isIntegral) {
        if (image.length() > 1 && image.charAt(0) == '0') {
            switch (image.charAt(1)) {
            case 'x':
@@ -132,10 +132,8 @@ public final class ASTNumericLiteral extends AbstractLiteral implements ASTLiter
            case 'b':
            case 'B':
                return 2;
-            case '.':
-                return 10;
            default:
-                return 8;
+                return isIntegral ? 8 : 10;
            }
        }
        return 10;
@@ -172,7 +170,7 @@ public final class ASTNumericLiteral extends AbstractLiteral implements ASTLiter
     * <p>Invalid literals or overflows result in {@code 0L}.
     */
    static long parseIntegralValue(Chars image) {
-        final int base = getBase(image);
+        final int base = getBase(image, true);
        if (base == 8) {
            image = image.subSequence(1); // 0
        } else if (base != 10) {
@@ -6,7 +6,6 @@
 package net.sourceforge.pmd.lang.java.ast;

 import net.sourceforge.pmd.lang.java.ast.ASTList.ASTMaybeEmptyListOf;
-import net.sourceforge.pmd.lang.java.ast.InternalInterfaces.AllChildrenAreOfType;
 import net.sourceforge.pmd.lang.java.symbols.JConstructorSymbol;

 /**
@@ -18,8 +17,7 @@ import net.sourceforge.pmd.lang.java.symbols.JConstructorSymbol;
 *
 * </pre>
 */
-public final class ASTRecordComponentList extends ASTMaybeEmptyListOf<ASTRecordComponent>
-        implements SymbolDeclaratorNode, AllChildrenAreOfType<ASTRecordComponent> {
+public final class ASTRecordComponentList extends ASTMaybeEmptyListOf<ASTRecordComponent> implements SymbolDeclaratorNode {

    private JConstructorSymbol symbol;

@@ -18,7 +18,7 @@ import net.sourceforge.pmd.util.StringUtil;
 * in the source ({@link #getLiteralText()}). {@link #getConstValue()} allows to recover
 * the actual runtime value, by processing escapes.
 */
-public final class ASTStringLiteral extends AbstractLiteral implements ASTLiteral {
+public final class ASTStringLiteral extends AbstractLiteral {

    private static final String TEXTBLOCK_DELIMITER = "\"\"\"";

@@ -18,9 +18,7 @@ import net.sourceforge.pmd.lang.ast.NodeStream;
 *
 * <p>Their syntax is identical though, and described on {@link ASTSwitchLike}.
 */
-public final class ASTSwitchExpression extends AbstractJavaExpr
-    implements ASTExpression,
-               ASTSwitchLike {
+public final class ASTSwitchExpression extends AbstractJavaExpr implements ASTSwitchLike {

    ASTSwitchExpression(int id) {
        super(id);
@@ -43,7 +43,7 @@ import net.sourceforge.pmd.lang.java.types.JTypeMirror;
 * <p>Note: This node has been called ASTVariableDeclaratorId in PMD 6.
 */
 // @formatter:on
-public final class ASTVariableId extends AbstractTypedSymbolDeclarator<JVariableSymbol> implements ModifierOwner, SymbolDeclaratorNode {
+public final class ASTVariableId extends AbstractTypedSymbolDeclarator<JVariableSymbol> implements ModifierOwner {

    private String name;
    private List<ASTNamedReferenceExpr> usages = Collections.emptyList();
@@ -127,6 +127,17 @@ public final class ASTVariableId extends AbstractTypedSymbolDeclarator<JVariable
        return (ModifierOwner) parent;
    }

+    /**
+     * Return true if this variable has no name. The name is then equal to {@code "_"}.
+     * A variable declaration with this name does not actually declare a variable in
+     * the current scope, since Java 22. In Java 9 to 21, the identifier {@code _} is
+     * restricted and cannot be used to name a variable. Before Java 9, it is a regular
+     * identifier.
+     */
+    public boolean isUnnamed() {
+        return "_".equals(name) && getLanguageVersion().compareToVersion("21-preview") >= 0;
+    }
+
    /** Returns the name of the variable. */
    public String getName() {
        return name;