add support for sealed classes

core/src/main/java/org/jboss/jandex/ClassInfo.java

@@ -75,6 +75,7 @@ public final class ClassInfo implements Declaration, Descriptor, GenericSignatur
     private boolean hasNoArgsConstructor;
     private NestingInfo nestingInfo;
     private Set<DotName> memberClasses;
+    private Set<DotName> permittedSubclasses;
 
     /** Describes the form of nesting used by a class */
     public enum NestingType {
@@ -267,6 +268,24 @@ public final boolean isInterface() {
         return Modifier.isInterface(flags);
     }
 
+    /**
+     * @return {@code true} if this class object represents a {@code final} class;
+     *         an interface is never {@code final}
+     * @since 3.2.0
+     */
+    public final boolean isFinal() {
+        return Modifier.isFinal(flags);
+    }
+
+    /**
+     * @return {@code true} if this class object represents an {@code abstract} class;
+     *         an interface is always {@code abstract}
+     * @since 3.2.0
+     */
+    public final boolean isAbstract() {
+        return Modifier.isAbstract(flags);
+    }
+
     /**
      *
      * @return {@code true} if this class object represents an enum type
@@ -1096,6 +1115,28 @@ public ModuleInfo module() {
         return nestingInfo != null ? nestingInfo.module : null;
     }
 
+    /**
+     * Returns the set of permitted subclasses of this {@code sealed} class (or interface).
+     * Returns an empty set if this class is not {@code sealed}.
+     *
+     * @return immutable set of names of this class's permitted subclasses, never {@code null}
+     * @since 3.2.0
+     */
+    public Set<DotName> permittedSubclasses() {
+        if (permittedSubclasses == null) {
+            return Collections.emptySet();
+        }
+        return Collections.unmodifiableSet(permittedSubclasses);
+    }
+
+    /**
+     * @return {@code true} if this class object represents a {@code sealed} class (or interface)
+     * @since 3.2.0
+     */
+    public boolean isSealed() {
+        return permittedSubclasses != null && !permittedSubclasses.isEmpty();
+    }
+
     /**
      * Returns whether this class must have a generic signature. That is, whether the Java compiler
      * when compiling this class had to emit the {@code Signature} bytecode attribute.
@@ -1363,4 +1404,8 @@ void setModule(ModuleInfo module) {
     void setFlags(short flags) {
         this.flags = flags;
     }
+
+    void setPermittedSubclasses(Set<DotName> permittedSubclasses) {
+        this.permittedSubclasses = permittedSubclasses;
+    }
 }

core/src/main/java/org/jboss/jandex/IndexReaderV2.java

@@ -50,7 +50,7 @@
  */
 final class IndexReaderV2 extends IndexReaderImpl {
     static final int MIN_VERSION = 6;
-    static final int MAX_VERSION = 11;
+    static final int MAX_VERSION = 12;
     private static final byte NULL_TARGET_TAG = 0;
     private static final byte FIELD_TAG = 1;
     private static final byte METHOD_TAG = 2;
@@ -629,6 +629,17 @@ private ClassInfo readClassEntry(PackedDataInputStream stream,
             }
         }
 
+        Set<DotName> permittedSubclasses = null;
+        if (version >= 12) {
+            int permittedSubclassesCount = stream.readPackedU32();
+            if (permittedSubclassesCount > 0) {
+                permittedSubclasses = new HashSet<>(permittedSubclassesCount);
+                for (int i = 0; i < permittedSubclassesCount; i++) {
+                    permittedSubclasses.add(nameTable[stream.readPackedU32()]);
+                }
+            }
+        }
+
         int size = stream.readPackedU32();
 
         Map<DotName, List<AnnotationInstance>> annotations = size > 0
@@ -647,6 +658,9 @@ private ClassInfo readClassEntry(PackedDataInputStream stream,
         if (memberClasses != null) {
             clazz.setMemberClasses(memberClasses);
         }
+        if (permittedSubclasses != null) {
+            clazz.setPermittedSubclasses(permittedSubclasses);
+        }
 
         FieldInternal[] fields = readClassFields(stream, clazz);
         clazz.setFieldArray(fields);

core/src/main/java/org/jboss/jandex/IndexWriterV2.java

@@ -54,7 +54,7 @@
  */
 final class IndexWriterV2 extends IndexWriterImpl {
     static final int MIN_VERSION = 6;
-    static final int MAX_VERSION = 11;
+    static final int MAX_VERSION = 12;
 
     // babelfish (no h)
     private static final int MAGIC = 0xBABE1F15;
@@ -606,6 +606,13 @@ private void writeClassEntry(PackedDataOutputStream stream, ClassInfo clazz) thr
             }
         }
 
+        if (version >= 12) {
+            stream.writePackedU32(clazz.permittedSubclasses().size());
+            for (DotName permittedSubclass : clazz.permittedSubclasses()) {
+                stream.writePackedU32(positionOf(permittedSubclass));
+            }
+        }
+
         // Annotation length is early to allow eager allocation in reader.
         stream.writePackedU32(clazz.annotationsMap().size());
 
@@ -938,6 +945,9 @@ private void addClass(ClassInfo clazz) {
         for (DotName memberClass : clazz.memberClasses()) {
             addClassName(memberClass);
         }
+        for (DotName permittedSubclass : clazz.permittedSubclasses()) {
+            addClassName(permittedSubclass);
+        }
 
         addMethodList(clazz.methodArray());
         names.intern(clazz.methodPositionArray());

core/src/main/java/org/jboss/jandex/Indexer.java

@@ -209,6 +209,14 @@ public final class Indexer {
             0x41, 0x6e, 0x6e, 0x6f, 0x74, 0x61, 0x74, 0x69, 0x6f, 0x6e, 0x73
     };
 
+    // "PermittedSubclasses"
+    private final static byte[] PERMITTED_SUBCLASSES = new byte[] {
+            // P     e     r     m     i     t     t     e     d
+            0x50, 0x65, 0x72, 0x6d, 0x69, 0x74, 0x74, 0x65, 0x64,
+            // S     u     b     c     l     a     s     s     e     s
+            0x53, 0x75, 0x62, 0x63, 0x6c, 0x61, 0x73, 0x73, 0x65, 0x73
+    };
+
     private final static int RUNTIME_ANNOTATIONS_LEN = RUNTIME_ANNOTATIONS.length;
     private final static int RUNTIME_PARAM_ANNOTATIONS_LEN = RUNTIME_PARAM_ANNOTATIONS.length;
     private final static int RUNTIME_TYPE_ANNOTATIONS_LEN = RUNTIME_TYPE_ANNOTATIONS.length;
@@ -227,6 +235,7 @@ public final class Indexer {
     private final static int RUNTIME_INVISIBLE_ANNOTATIONS_LEN = RUNTIME_INVISIBLE_ANNOTATIONS.length;
     private final static int RUNTIME_INVISIBLE_PARAM_ANNOTATIONS_LEN = RUNTIME_INVISIBLE_PARAM_ANNOTATIONS.length;
     private final static int RUNTIME_INVISIBLE_TYPE_ANNOTATIONS_LEN = RUNTIME_INVISIBLE_TYPE_ANNOTATIONS.length;
+    private final static int PERMITTED_SUBCLASSES_LEN = PERMITTED_SUBCLASSES.length;
 
     private final static int HAS_RUNTIME_ANNOTATION = 1;
     private final static int HAS_RUNTIME_PARAM_ANNOTATION = 2;
@@ -246,6 +255,7 @@ public final class Indexer {
     private final static int HAS_RUNTIME_INVISIBLE_ANNOTATION = 16;
     private final static int HAS_RUNTIME_INVISIBLE_PARAM_ANNOTATION = 17;
     private final static int HAS_RUNTIME_INVISIBLE_TYPE_ANNOTATION = 18;
+    private final static int HAS_PERMITTED_SUBCLASSES = 19;
 
     private static class InnerClassInfo {
         private InnerClassInfo(DotName innerClass, DotName enclosingClass, String simpleName, int flags) {
@@ -528,6 +538,18 @@ private void processRecordComponents(DataInputStream data) throws IOException {
         this.recordComponents = recordComponents;
     }
 
+    private void processPermittedSubclasses(DataInputStream data, ClassInfo target) throws IOException {
+        int numPermittedSubclasses = data.readUnsignedShort();
+        if (numPermittedSubclasses > 0) {
+            Set<DotName> permittedSubclasses = new HashSet<>(numPermittedSubclasses);
+            for (int i = 0; i < numPermittedSubclasses; i++) {
+                DotName name = decodeClassEntry(data.readUnsignedShort());
+                permittedSubclasses.add(name);
+            }
+            target.setPermittedSubclasses(permittedSubclasses);
+        }
+    }
+
     private void processAttributes(DataInputStream data, AnnotationTarget target) throws IOException {
         int numAttrs = data.readUnsignedShort();
         byte[] constantPoolAnnoAttrributes = this.constantPoolAnnoAttrributes;
@@ -583,6 +605,8 @@ private void processAttributes(DataInputStream data, AnnotationTarget target) th
                 processModuleMainClass(data, (ClassInfo) target);
             } else if (annotationAttribute == HAS_RECORD && target instanceof ClassInfo) {
                 processRecordComponents(data);
+            } else if (annotationAttribute == HAS_PERMITTED_SUBCLASSES && target instanceof ClassInfo) {
+                processPermittedSubclasses(data, (ClassInfo) target);
             } else {
                 skipFully(data, attributeLen);
             }
@@ -2404,6 +2428,8 @@ && match(buf, offset, RUNTIME_INVISIBLE_PARAM_ANNOTATIONS)) {
                     } else if (len == RUNTIME_INVISIBLE_TYPE_ANNOTATIONS_LEN
                             && match(buf, offset, RUNTIME_INVISIBLE_TYPE_ANNOTATIONS)) {
                         annoAttributes[pos] = HAS_RUNTIME_INVISIBLE_TYPE_ANNOTATION;
+                    } else if (len == PERMITTED_SUBCLASSES_LEN && match(buf, offset, PERMITTED_SUBCLASSES)) {
+                        annoAttributes[pos] = HAS_PERMITTED_SUBCLASSES;
                     }
                     offset += len;
                     break;

core/src/test/java/org/jboss/jandex/test/ModuleInfoTestCase.java

@@ -63,7 +63,7 @@ public void testModuleAnnotations() throws IOException {
     public void testModulePackagesListed() throws IOException {
         ModuleInfo mod = indexModuleInfo();
         List<DotName> expected = Arrays.asList(DotName.createSimple("test"),
-                DotName.createSimple("test.exec"));
+                DotName.createSimple("test.exec"), DotName.createSimple("test.expr"));
         assertEquals(expected.size(), mod.packages().size());
         for (DotName e : expected) {
             assertTrue(mod.packages().contains(e));
@@ -91,11 +91,13 @@ public void testModuleExports() {
     @Test
     public void testModuleOpens() {
         List<OpenedPackageInfo> opens = mod.opens();
-        assertEquals(2, opens.size());
+        assertEquals(3, opens.size());
         assertEquals("test", opens.get(0).source().toString());
         assertEquals("java.base", opens.get(0).targets().get(0).toString());
         assertEquals("test.exec", opens.get(1).source().toString());
         assertEquals("java.base", opens.get(1).targets().get(0).toString());
+        assertEquals("test.expr", opens.get(2).source().toString());
+        assertEquals("java.base", opens.get(2).targets().get(0).toString());
     }
 
     @Test

core/src/test/java/org/jboss/jandex/test/PermittedSubclassesTest.java

@@ -0,0 +1,80 @@
+package org.jboss.jandex.test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.io.IOException;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Set;
+
+import org.jboss.jandex.ClassInfo;
+import org.jboss.jandex.DotName;
+import org.jboss.jandex.Index;
+import org.jboss.jandex.Indexer;
+import org.jboss.jandex.test.util.IndexingUtil;
+import org.junit.jupiter.api.Test;
+
+public class PermittedSubclassesTest {
+    @Test
+    public void test() throws IOException {
+        Indexer indexer = new Indexer();
+        indexer.index(PermittedSubclassesTest.class.getResourceAsStream("/test/expr/Add.class"));
+        indexer.index(PermittedSubclassesTest.class.getResourceAsStream("/test/expr/Arith.class"));
+        indexer.index(PermittedSubclassesTest.class.getResourceAsStream("/test/expr/BestValue.class"));
+        indexer.index(PermittedSubclassesTest.class.getResourceAsStream("/test/expr/Expr.class"));
+        indexer.index(PermittedSubclassesTest.class.getResourceAsStream("/test/expr/Mul.class"));
+        indexer.index(PermittedSubclassesTest.class.getResourceAsStream("/test/expr/Value.class"));
+        Index index = indexer.complete();
+
+        doTest(index);
+        doTest(IndexingUtil.roundtrip(index));
+    }
+
+    private void doTest(Index index) {
+        ClassInfo expr = index.getClassByName("test.expr.Expr");
+        assertTrue(expr.isSealed());
+        assertFalse(expr.isFinal());
+        assertEquals(setOf("test.expr.Value", "test.expr.Arith"), expr.permittedSubclasses());
+
+        ClassInfo value = index.getClassByName("test.expr.Value");
+        assertFalse(value.isSealed());
+        assertFalse(value.isFinal());
+        assertTrue(value.interfaceNames().contains(DotName.createSimple("test.expr.Expr")));
+        assertEquals(Collections.emptySet(), value.permittedSubclasses());
+
+        ClassInfo bestValue = index.getClassByName("test.expr.BestValue");
+        assertFalse(bestValue.isSealed());
+        assertFalse(bestValue.isFinal());
+        assertEquals(bestValue.superName(), DotName.createSimple("test.expr.Value"));
+        assertEquals(Collections.emptySet(), bestValue.permittedSubclasses());
+
+        ClassInfo arith = index.getClassByName("test.expr.Arith");
+        assertTrue(arith.isSealed());
+        assertFalse(arith.isFinal());
+        assertTrue(arith.isAbstract());
+        assertTrue(value.interfaceNames().contains(DotName.createSimple("test.expr.Expr")));
+        assertEquals(setOf("test.expr.Add", "test.expr.Mul"), arith.permittedSubclasses());
+
+        ClassInfo add = index.getClassByName("test.expr.Add");
+        assertFalse(add.isSealed());
+        assertTrue(add.isFinal());
+        assertEquals(DotName.createSimple("test.expr.Arith"), add.superName());
+        assertEquals(Collections.emptySet(), value.permittedSubclasses());
+
+        ClassInfo mul = index.getClassByName("test.expr.Mul");
+        assertFalse(mul.isSealed());
+        assertTrue(mul.isFinal());
+        assertEquals(DotName.createSimple("test.expr.Arith"), mul.superName());
+        assertEquals(Collections.emptySet(), value.permittedSubclasses());
+    }
+
+    private static Set<DotName> setOf(String... strings) {
+        Set<DotName> result = new HashSet<>();
+        for (String string : strings) {
+            result.add(DotName.createSimple(string));
+        }
+        return result;
+    }
+}

doc/modules/ROOT/pages/index.adoc

@@ -62,6 +62,9 @@ It is also a maximum persistent index format version the given Jandex version ca
 |===
 |Jandex version |Persistent format version
 
+|Jandex 3.2.x
+|12
+
 |Jandex 3.0.x, 3.1.x
 |11
 

test-data/src/main/java/module-info.java

@@ -11,6 +11,7 @@
 
     opens test to java.base;
     opens test.exec to java.base;
+    opens test.expr to java.base;
 
     provides test.ServiceProviderExample
         with test.ServiceProviderExample.ServiceProviderExampleImpl;

test-data/src/main/java/test/expr/Add.java

@@ -0,0 +1,16 @@
+package test.expr;
+
+public final class Add extends Arith {
+    private final Expr left;
+    private final Expr right;
+
+    public Add(Expr left, Expr right) {
+        this.left = left;
+        this.right = right;
+    }
+
+    @Override
+    public int eval() {
+        return left.eval() + right.eval();
+    }
+}

test-data/src/main/java/test/expr/Arith.java

@@ -0,0 +1,4 @@
+package test.expr;
+
+public sealed abstract class Arith implements Expr permits Add, Mul {
+}

test-data/src/main/java/test/expr/BestValue.java

@@ -0,0 +1,7 @@
+package test.expr;
+
+public class BestValue extends Value {
+    public BestValue() {
+        super(42);
+    }
+}

test-data/src/main/java/test/expr/Expr.java

@@ -0,0 +1,5 @@
+package test.expr;
+
+public sealed interface Expr permits Value, Arith {
+    int eval();
+}

test-data/src/main/java/test/expr/Mul.java

@@ -0,0 +1,16 @@
+package test.expr;
+
+public final class Mul extends Arith {
+    private final Expr left;
+    private final Expr right;
+
+    public Mul(Expr left, Expr right) {
+        this.left = left;
+        this.right = right;
+    }
+
+    @Override
+    public int eval() {
+        return left.eval() * right.eval();
+    }
+}

test-data/src/main/java/test/expr/Value.java

@@ -0,0 +1,14 @@
+package test.expr;
+
+public non-sealed class Value implements Expr {
+    private final int value;
+
+    public Value(int value) {
+        this.value = value;
+    }
+
+    @Override
+    public int eval() {
+        return value;
+    }
+}