RFR: JDK-8322878: Including sealing information Class.toGenericString()

[Pavel Rappo]

On Wed, 3 Jan 2024 18:16:24 GMT, Joe Darcy <darcy at openjdk.org> wrote:

> Since it doesn't seem possible to do so, I did not attempt to relay "non-sealed" information in this PR :-)

Naively, I thought that something like this is possible _in principle_; I might be mistaken though:

diff --git a/src/java.base/share/classes/java/lang/Class.java b/src/java.base/share/classes/java/lang/Class.java
index 851d65d06ad..014845860d0 100644
--- a/src/java.base/share/classes/java/lang/Class.java
+++ b/src/java.base/share/classes/java/lang/Class.java
@@ -4771,6 +4771,30 @@ public boolean isSealed() {
         return getPermittedSubclasses() != null;
     }
 
+    private boolean isNonSealed() {
+        if (isSealed())
+            return false;
+        if (!isInterface() && Modifier.isFinal(getModifiers())) {
+            // unlike interface, class can be final
+            return false;
+        }
+        // if an ancestor is sealed, this class can either be non-sealed or final
+        return hasSealedAncestor(this);
+    }
+
+    private boolean hasSealedAncestor(Class<?> clazz) {
+        var superclass = clazz.getSuperclass();
+        if (superclass != null) {
+            if (superclass.isSealed() || hasSealedAncestor(superclass))
+                return true;
+        }
+        for (var superinterface : clazz.getInterfaces()) {
+            if (superinterface.isSealed() || hasSealedAncestor(superinterface))
+                return true;
+        }
+        return false;
+    }
+
     private native Class<?>[] getPermittedSubclasses0();
 
     /*

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PR Review Comment: https://git.openjdk.org/jdk/pull/17239#discussion_r1440867004