8361214: An anonymous class is erroneously being classify as an abstract class

Reviewed-by: liach, mcimadamore

Author: Vicente Romero

src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Attr.java

@@ -2833,7 +2833,7 @@ public void visitNewClass(final JCNewClass tree) {
                     resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.SPECULATIVE;
             boolean skipNonDiamondPath = false;
             // Check that class is not abstract
-            if (cdef == null && !isSpeculativeDiamondInferenceRound && // class body may be nulled out in speculative tree copy
+            if (cdef == null && !tree.classDeclRemoved() && !isSpeculativeDiamondInferenceRound && // class body may be nulled out in speculative tree copy
                 (clazztype.tsym.flags() & (ABSTRACT | INTERFACE)) != 0) {
                 log.error(tree.pos(),
                           Errors.AbstractCantBeInstantiated(clazztype.tsym));

test/langtools/tools/javac/generics/diamond/AnonymousLabeledAsAbstractTest.java

@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) 2025, 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.
+ *
+ * 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.
+ */
+
+/*
+ * @test
+ * @bug 8361214
+ * @summary An anonymous class is erroneously being classify as an abstract class
+ * @compile AnonymousLabeledAsAbstractTest.java
+ */
+
+class AnonymousLabeledAsAbstractTest {
+    abstract class Base<T> {}
+    abstract class Derived1<T> extends Base<T> {}
+    abstract class Derived2<T> extends Base<T> {
+        Derived2(Derived1<T> obj){}
+    }
+    abstract class Derived3<T> extends Base<T> {
+        Derived3(Derived2<T> obj){}
+    }
+
+    Base<String> obj = new Derived2<>(new Derived1<>(){}){};
+    Base<String> obj2 = new Derived3<String>(new Derived2<>(new Derived1<>(){}){}){};
+    Base<String> obj3 = new Derived3<>(new Derived2<>(new Derived1<>(){}){}){};
+}