8314913: [lw5] null restrictions can only be applied to value classes

src/jdk.compiler/share/classes/com/sun/tools/javac/code/Type.java

@@ -1153,9 +1153,7 @@ public <R,S> R accept(Type.Visitor<R,S> v, S s) {
         }
 
         public Type constType(Object constValue) {
-            return isPrimitive() ?
-                    addMetadata(new ConstantValue(constValue)) :
-                    addMetadata(new ConstantValue(constValue)).addMetadata(new TypeMetadata.NullMarker(NullMarker.NOT_NULL));
+            return addMetadata(new ConstantValue(constValue));
         }
 
         /** The Java source which this type represents.

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

@@ -1345,6 +1345,17 @@ public void visitVarDef(JCVariableDecl tree) {
                     log.error(tree, Errors.IllegalRecordComponentName(v));
                 }
             }
+            Type elemOrType = result;
+            while (!elemOrType.hasTag(ERROR) && types.elemtype(elemOrType) != null) {
+                elemOrType = types.elemtype(elemOrType);
+            }
+            if ((result.isNonNullable() || elemOrType.isNonNullable()) && (!elemOrType.isValueClass() || !elemOrType.hasImplicitConstructor())) {
+                log.error(tree.pos(),
+                        types.elemtype(result) == null?
+                                Errors.TypeCantBeNullRestricted(result) :
+                                Errors.TypeCantBeNullRestricted2(result)
+                );
+            }
         }
         finally {
             chk.setLint(prevLint);

src/jdk.compiler/share/classes/com/sun/tools/javac/resources/compiler.properties

@@ -4164,11 +4164,21 @@ compiler.err.enclosing.class.type.non.denotable=\
     enclosing class type: {0}\n\
     is non-denotable, try casting to a denotable type
 
-### bang types
+### null-restricted types
 
 compiler.err.non.nullable.cannot.be.assigned.null=\
     non-nullable type cannot be assigned null
 
+# 0: type
+compiler.err.type.cant.be.null.restricted=\
+    type: {0}, cannot be a null restricted type\n\
+    it must be a value class with an implicit constructor
+
+# 0: type
+compiler.err.type.cant.be.null.restricted.2=\
+    type: {0}, cannot be a null restricted type\n\
+    its element type must be a value class with an implicit constructor
+
 compiler.warn.narrowing.nullness.conversion=\
     narrowing nullness conversion
 

test/langtools/tools/javac/annotations/typeAnnotations/referenceinfos/NewObjects.java

@@ -61,14 +61,14 @@ public String initObjectGeneric() {
 
     @TADescription(annotation = "TA", type = NEW, offset = ReferenceInfoUtil.IGNORE_VALUE)
     public String eqtestObject() {
-        return "void eqtestObject(String! s) { if (s == new @TA String()); }";
+        return "void eqtestObject(String s) { if (s == new @TA String()); }";
     }
 
     @TADescription(annotation = "TA", type = NEW, offset = ReferenceInfoUtil.IGNORE_VALUE)
     @TADescription(annotation = "TB", type = NEW,
             genericLocation = { 3, 0 }, offset = ReferenceInfoUtil.IGNORE_VALUE)
     public String eqtestObjectGeneric() {
-        return "void eqtestObjectGeneric(ArrayList!<String> as) { if (as == new @TA ArrayList<@TB String >()); }";
+        return "void eqtestObjectGeneric(ArrayList<String> as) { if (as == new @TA ArrayList<@TB String >()); }";
     }
 
     @TADescription(annotation = "TA", type = NEW, offset = ReferenceInfoUtil.IGNORE_VALUE,
@@ -165,14 +165,14 @@ public String initObjectGenericRepeatableAnnotation() {
 
     @TADescription(annotation = "RTAs", type = NEW, offset = ReferenceInfoUtil.IGNORE_VALUE)
     public String eqtestObjectRepeatableAnnotation() {
-        return "void eqtestObject(String! s) { if (s == new @RTA @RTA String()); }";
+        return "void eqtestObject(String s) { if (s == new @RTA @RTA String()); }";
     }
 
     @TADescription(annotation = "RTAs", type = NEW, offset = ReferenceInfoUtil.IGNORE_VALUE)
     @TADescription(annotation = "RTBs", type = NEW,
             genericLocation = { 3, 0 }, offset = ReferenceInfoUtil.IGNORE_VALUE)
     public String eqtestObjectGenericRepeatableAnnotation() {
-        return "void eqtestObjectGeneric(ArrayList!<String> as) { if (as == new @RTA @RTA ArrayList<@RTB @RTB String >()); }";
+        return "void eqtestObjectGeneric(ArrayList<String> as) { if (as == new @RTA @RTA ArrayList<@RTB @RTB String >()); }";
     }
 
     @TADescription(annotation = "RTAs", type = NEW, offset = ReferenceInfoUtil.IGNORE_VALUE,

test/langtools/tools/javac/diags/examples/CantBeNonNullableType.java

@@ -0,0 +1,30 @@
+/*
+ * Copyright (c) 2023, 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.
+ */
+
+// key: compiler.err.type.cant.be.null.restricted
+// key: compiler.err.type.cant.be.null.restricted.2
+
+public class CantBeNonNullableType {
+    String! s;
+    String[]! sa;
+}