8345319: Fix the tag type in PoolEntry and AnnotationValue

Reviewed-by: asotona

src/java.base/share/classes/java/lang/classfile/AnnotationValue.java

@@ -456,9 +456,11 @@ public sealed interface AnnotationValue {
      *
      * @apiNote
      * {@code TAG_}-prefixed constants in this class, such as {@link #TAG_INT},
-     * describe the possible return values of this method.
+     * describe the possible return values of this method.  The return type is
+     * {@code int} for consistency with union indicator items in other union
+     * structures in the {@code class} file format.
      */
-    char tag();
+    int tag();
 
     /**
      * {@return an enum value for an element-value pair}

src/java.base/share/classes/java/lang/classfile/constantpool/PoolEntry.java

@@ -98,7 +98,7 @@ public sealed interface PoolEntry
      * {@code TAG_}-prefixed constants in this class, such as {@link #TAG_UTF8},
      * describe the possible return values of this method.
      */
-    byte tag();
+    int tag();
 
     /**
      * {@return the index within the constant pool corresponding to this entry}

src/java.base/share/classes/jdk/internal/classfile/impl/AbstractPoolEntry.java

@@ -104,7 +104,7 @@ public abstract sealed class AbstractPoolEntry {
         return hash;
     }
 
-    public abstract byte tag();
+    public abstract int tag();
 
     public int width() {
         return 1;
@@ -181,7 +181,7 @@ public abstract sealed class AbstractPoolEntry {
         }
 
         @Override
-        public byte tag() {
+        public int tag() {
             return TAG_UTF8;
         }
 
@@ -522,7 +522,7 @@ public abstract sealed class AbstractPoolEntry {
         }
 
         @Override
-        public byte tag() {
+        public int tag() {
             return TAG_CLASS;
         }
 
@@ -582,7 +582,7 @@ public abstract sealed class AbstractPoolEntry {
         }
 
         @Override
-        public byte tag() {
+        public int tag() {
             return TAG_PACKAGE;
         }
 
@@ -613,7 +613,7 @@ public abstract sealed class AbstractPoolEntry {
         }
 
         @Override
-        public byte tag() {
+        public int tag() {
             return TAG_MODULE;
         }
 
@@ -645,7 +645,7 @@ public abstract sealed class AbstractPoolEntry {
         }
 
         @Override
-        public byte tag() {
+        public int tag() {
             return TAG_NAME_AND_TYPE;
         }
 
@@ -719,7 +719,7 @@ public abstract sealed class AbstractPoolEntry {
         }
 
         @Override
-        public byte tag() {
+        public int tag() {
             return TAG_FIELDREF;
         }
 
@@ -737,7 +737,7 @@ public abstract sealed class AbstractPoolEntry {
         }
 
         @Override
-        public byte tag() {
+        public int tag() {
             return TAG_METHODREF;
         }
 
@@ -755,7 +755,7 @@ public abstract sealed class AbstractPoolEntry {
         }
 
         @Override
-        public byte tag() {
+        public int tag() {
             return TAG_INTERFACE_METHODREF;
         }
 
@@ -849,7 +849,7 @@ public abstract sealed class AbstractPoolEntry {
         }
 
         @Override
-        public byte tag() {
+        public int tag() {
             return TAG_INVOKE_DYNAMIC;
         }
 
@@ -874,7 +874,7 @@ public abstract sealed class AbstractPoolEntry {
         }
 
         @Override
-        public byte tag() {
+        public int tag() {
             return TAG_DYNAMIC;
         }
 
@@ -905,7 +905,7 @@ public abstract sealed class AbstractPoolEntry {
         }
 
         @Override
-        public byte tag() {
+        public int tag() {
             return TAG_METHOD_HANDLE;
         }
 
@@ -964,7 +964,7 @@ public abstract sealed class AbstractPoolEntry {
         }
 
         @Override
-        public byte tag() {
+        public int tag() {
             return TAG_METHOD_TYPE;
         }
 
@@ -1002,7 +1002,7 @@ public abstract sealed class AbstractPoolEntry {
         }
 
         @Override
-        public byte tag() {
+        public int tag() {
             return TAG_STRING;
         }
 
@@ -1054,7 +1054,7 @@ public abstract sealed class AbstractPoolEntry {
         }
 
         @Override
-        public byte tag() {
+        public int tag() {
             return TAG_INTEGER;
         }
 
@@ -1100,7 +1100,7 @@ public abstract sealed class AbstractPoolEntry {
         }
 
         @Override
-        public byte tag() {
+        public int tag() {
             return TAG_FLOAT;
         }
 
@@ -1145,7 +1145,7 @@ public abstract sealed class AbstractPoolEntry {
         }
 
         @Override
-        public byte tag() {
+        public int tag() {
             return TAG_LONG;
         }
 
@@ -1195,7 +1195,7 @@ public abstract sealed class AbstractPoolEntry {
         }
 
         @Override
-        public byte tag() {
+        public int tag() {
             return TAG_DOUBLE;
         }
 

src/java.base/share/classes/jdk/internal/classfile/impl/AnnotationImpl.java

@@ -72,7 +72,7 @@ public record AnnotationImpl(Utf8Entry className, List<AnnotationElement> elemen
     public record OfStringImpl(Utf8Entry constant)
             implements AnnotationValue.OfString {
         @Override
-        public char tag() {
+        public int tag() {
             return TAG_STRING;
         }
 
@@ -85,7 +85,7 @@ public record AnnotationImpl(Utf8Entry className, List<AnnotationElement> elemen
     public record OfDoubleImpl(DoubleEntry constant)
             implements AnnotationValue.OfDouble {
         @Override
-        public char tag() {
+        public int tag() {
             return TAG_DOUBLE;
         }
 
@@ -98,7 +98,7 @@ public record AnnotationImpl(Utf8Entry className, List<AnnotationElement> elemen
     public record OfFloatImpl(FloatEntry constant)
             implements AnnotationValue.OfFloat {
         @Override
-        public char tag() {
+        public int tag() {
             return TAG_FLOAT;
         }
 
@@ -111,7 +111,7 @@ public record AnnotationImpl(Utf8Entry className, List<AnnotationElement> elemen
     public record OfLongImpl(LongEntry constant)
             implements AnnotationValue.OfLong {
         @Override
-        public char tag() {
+        public int tag() {
             return TAG_LONG;
         }
 
@@ -124,7 +124,7 @@ public record AnnotationImpl(Utf8Entry className, List<AnnotationElement> elemen
     public record OfIntImpl(IntegerEntry constant)
             implements AnnotationValue.OfInt {
         @Override
-        public char tag() {
+        public int tag() {
             return TAG_INT;
         }
 
@@ -137,7 +137,7 @@ public record AnnotationImpl(Utf8Entry className, List<AnnotationElement> elemen
     public record OfShortImpl(IntegerEntry constant)
             implements AnnotationValue.OfShort {
         @Override
-        public char tag() {
+        public int tag() {
             return TAG_SHORT;
         }
 
@@ -150,7 +150,7 @@ public record AnnotationImpl(Utf8Entry className, List<AnnotationElement> elemen
     public record OfCharImpl(IntegerEntry constant)
             implements AnnotationValue.OfChar {
         @Override
-        public char tag() {
+        public int tag() {
             return TAG_CHAR;
         }
 
@@ -163,7 +163,7 @@ public record AnnotationImpl(Utf8Entry className, List<AnnotationElement> elemen
     public record OfByteImpl(IntegerEntry constant)
             implements AnnotationValue.OfByte {
         @Override
-        public char tag() {
+        public int tag() {
             return TAG_BYTE;
         }
 
@@ -176,7 +176,7 @@ public record AnnotationImpl(Utf8Entry className, List<AnnotationElement> elemen
     public record OfBooleanImpl(IntegerEntry constant)
             implements AnnotationValue.OfBoolean {
         @Override
-        public char tag() {
+        public int tag() {
             return TAG_BOOLEAN;
         }
 
@@ -193,7 +193,7 @@ public record AnnotationImpl(Utf8Entry className, List<AnnotationElement> elemen
         }
 
         @Override
-        public char tag() {
+        public int tag() {
             return TAG_ARRAY;
         }
     }
@@ -201,7 +201,7 @@ public record AnnotationImpl(Utf8Entry className, List<AnnotationElement> elemen
     public record OfEnumImpl(Utf8Entry className, Utf8Entry constantName)
             implements AnnotationValue.OfEnum {
         @Override
-        public char tag() {
+        public int tag() {
             return TAG_ENUM;
         }
     }
@@ -209,7 +209,7 @@ public record AnnotationImpl(Utf8Entry className, List<AnnotationElement> elemen
     public record OfAnnotationImpl(Annotation annotation)
             implements AnnotationValue.OfAnnotation {
         @Override
-        public char tag() {
+        public int tag() {
             return TAG_ANNOTATION;
         }
     }
@@ -217,7 +217,7 @@ public record AnnotationImpl(Utf8Entry className, List<AnnotationElement> elemen
     public record OfClassImpl(Utf8Entry className)
             implements AnnotationValue.OfClass {
         @Override
-        public char tag() {
+        public int tag() {
             return TAG_CLASS;
         }
     }

src/java.base/share/classes/jdk/internal/classfile/impl/AnnotationReader.java

@@ -354,7 +354,7 @@ public final class AnnotationReader {
     public static void writeAnnotationValue(BufWriterImpl buf, AnnotationValue value) {
         var tag = value.tag();
         buf.writeU1(tag);
-        switch (value.tag()) {
+        switch (tag) {
             case TAG_BOOLEAN, TAG_BYTE, TAG_CHAR, TAG_DOUBLE, TAG_FLOAT, TAG_INT, TAG_LONG, TAG_SHORT, TAG_STRING ->
                     buf.writeIndex(((AnnotationValue.OfConstant) value).constant());
             case TAG_CLASS -> buf.writeIndex(((AnnotationValue.OfClass) value).className());