1 /*
  2  * Copyright (c) 2026, Oracle and/or its affiliates. All rights reserved.
  3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  4  *
  5  * This code is free software; you can redistribute it and/or modify it
  6  * under the terms of the GNU General Public License version 2 only, as
  7  * published by the Free Software Foundation.
  8  *
  9  * This code is distributed in the hope that it will be useful, but WITHOUT
 10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 12  * version 2 for more details (a copy is included in the LICENSE file that
 13  * accompanied this code).
 14  *
 15  * You should have received a copy of the GNU General Public License version
 16  * 2 along with this work; if not, write to the Free Software Foundation,
 17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 18  *
 19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 20  * or visit www.oracle.com if you need additional information or have any
 21  * questions.
 22  */
 23 
 24 import jdk.internal.vm.annotation.LooselyConsistentValue;
 25 import jdk.internal.vm.annotation.NullRestricted;
 26 
 27 import jdk.test.lib.Asserts;
 28 
 29 public class NullableFlatFieldApp {
 30 
 31   @LooselyConsistentValue
 32   static value class Value0 {
 33     long l;
 34     int i;
 35     short s;
 36     byte b;
 37 
 38     Value0() {
 39       l = 0;
 40       i = 0;
 41       s = 0;
 42       b = 0;
 43     }
 44 
 45     Value0(long l0, int i0, short s0, byte b0) {
 46       l = l0;
 47       i = i0;
 48       s = s0;
 49       b = b0;
 50     }
 51   }
 52 
 53   static class Container0 {
 54     Value0 val;
 55     long l;
 56     int i;
 57   }
 58 
 59   // Container0 had a external null marker located just between two Java fields,
 60   // and test0 checks that updating the null marker doesn't corrupt
 61   // the surrounding fields and vice-versa.
 62   static void test0() {
 63     Container0 c = new Container0();
 64     Asserts.assertNull(c.val);
 65     Asserts.assertEquals(c.l, 0L);
 66     Asserts.assertEquals(c.i, 0);
 67     c.l = -1L;
 68     c.i = -1;
 69     Asserts.assertNull(c.val);
 70     Value0 v = new Value0(-1L, -1, (short)-1, (byte)-1);
 71     c.val = v;
 72     Asserts.assertEquals(c.l, -1L);
 73     Asserts.assertEquals(c.i, -1);
 74     Value0 vr = c.val;
 75     Asserts.assertEquals(vr.l, -1L);
 76     Asserts.assertEquals(vr.i, -1);
 77     Asserts.assertEquals(vr.s, (short)-1);
 78     Asserts.assertEquals(vr.b, (byte)-1);
 79     c.val = null;
 80     Asserts.assertEquals(c.l, -1L);
 81     Asserts.assertEquals(c.i, -1);
 82   }
 83 
 84   @LooselyConsistentValue
 85   static value class Value1a {
 86     long l;
 87     short s;
 88     byte b;
 89 
 90     Value1a() {
 91       l = 0;
 92       s = 0;
 93       b = 0;
 94     }
 95 
 96     Value1a(long l0, short s0, byte b0) {
 97       l = l0;
 98       s = s0;
 99       b = b0;
100     }
101   }
102 
103   @LooselyConsistentValue
104   static value class Value1b {
105     @NullRestricted
106     Value1a vala;
107     long l;
108     int i;
109 
110     Value1b() {
111       vala = new Value1a();
112       l = 1L;
113       i = 1;
114     }
115 
116     Value1b(Value1a v0, long l0, int i0) {
117       vala = v0;
118       l = l0;
119       i = i0;
120     }
121   }
122 
123   static class Container1 {
124     Value1b valb;
125   }
126 
127   // Container1 has a nullable flat field with an internal null marker,
128   // test1 checks that updating the null marker doesn't corrupt the
129   // flat field's values
130   static void test1() {
131     Container1 c = new Container1();
132     Asserts.assertNull(c.valb);
133     Value1a va = new Value1a(-1L, (short)-1, (byte)-1);
134     Asserts.assertEquals(va.l, -1L);
135     Asserts.assertEquals(va.s, (short)-1);
136     Asserts.assertEquals(va.b, (byte)-1);
137     Value1b vb = new Value1b(va, -1L, -1);
138     Asserts.assertNotNull(vb.vala);
139     Asserts.assertEquals(vb.vala.l, -1L);
140     Asserts.assertEquals(vb.vala.s, (short)-1);
141     Asserts.assertEquals(vb.vala.b, (byte)-1);
142     c.valb = vb;
143     Asserts.assertNotNull(c.valb);
144     Asserts.assertEquals(c.valb, vb);
145     Asserts.assertEquals(c.valb.vala, va);
146     Asserts.assertEquals(c.valb.l, -1L);
147     Asserts.assertEquals(c.valb.i, -1);
148     c.valb = null;
149     Asserts.assertNull(c.valb);
150   }
151 
152   @LooselyConsistentValue
153   static value class Value2a {
154     long l;
155     int i;
156     byte b;
157     Value2a() {
158       l = 0;
159       i = 0;
160       b = 0;
161     }
162     Value2a(long l0, int i0, byte b0) {
163       l = l0;
164       i = i0;
165       b = b0;
166     }
167   }
168 
169   @LooselyConsistentValue
170   static value class Value2b {
171     long l;
172     Value2b() {
173       l = 0;
174     }
175     Value2b(long l0) {
176       l = l0;
177     }
178   }
179 
180   static class Container2 {
181     Value2a vala;
182     Value2b valb0;
183     Value2b valb1;
184     int i;
185   }
186 
187   // Container2 has 3 contiguous null markers,
188   // test2 checks that updating a null marker doesn't affect the other markers
189   public static void test2() {
190     Container2 c = new Container2();
191     Asserts.assertNull(c.vala);
192     Asserts.assertNull(c.valb0);
193     Asserts.assertNull(c.valb1);
194     Value2a va = new Value2a(-1L, -1, (byte)-1);
195     c.vala = va;
196     Asserts.assertNotNull(c.vala);
197     Asserts.assertNull(c.valb0);
198     Asserts.assertNull(c.valb1);
199     c.vala = null;
200     Asserts.assertNull(c.vala);
201     Asserts.assertNull(c.valb0);
202     Asserts.assertNull(c.valb1);
203     Value2b vb = new Value2b(-1L);
204     c.valb0 = vb;
205     Asserts.assertNull(c.vala);
206     Asserts.assertNotNull(c.valb0);
207     Asserts.assertNull(c.valb1);
208     c.valb0 = null;
209     Asserts.assertNull(c.vala);
210     Asserts.assertNull(c.valb0);
211     Asserts.assertNull(c.valb1);
212     c.valb1 = vb;
213     Asserts.assertNull(c.vala);
214     Asserts.assertNull(c.valb0);
215     Asserts.assertNotNull(c.valb1);
216     c.valb1 = null;
217     Asserts.assertNull(c.vala);
218     Asserts.assertNull(c.valb0);
219     Asserts.assertNull(c.valb1);
220     c.vala = va;
221     c.valb0 = vb;
222     c.valb1 = vb;
223     Asserts.assertNotNull(c.vala);
224     Asserts.assertNotNull(c.valb0);
225     Asserts.assertNotNull(c.valb1);
226     c.vala = null;
227     Asserts.assertNull(c.vala);
228     Asserts.assertNotNull(c.valb0);
229     Asserts.assertNotNull(c.valb1);
230     c.vala = va;
231     Asserts.assertNotNull(c.vala);
232     Asserts.assertNotNull(c.valb0);
233     Asserts.assertNotNull(c.valb1);
234     c.valb0 = null;
235     Asserts.assertNotNull(c.vala);
236     Asserts.assertNull(c.valb0);
237     Asserts.assertNotNull(c.valb1);
238     c.valb0 = vb;
239     Asserts.assertNotNull(c.vala);
240     Asserts.assertNotNull(c.valb0);
241     Asserts.assertNotNull(c.valb1);
242     c.valb1 = null;
243     Asserts.assertNotNull(c.vala);
244     Asserts.assertNotNull(c.valb0);
245     Asserts.assertNull(c.valb1);
246     c.valb1 = vb;
247     Asserts.assertNotNull(c.vala);
248     Asserts.assertNotNull(c.valb0);
249     Asserts.assertNotNull(c.valb1);
250   }
251 
252   @LooselyConsistentValue
253   static value class Value3 {
254     int i = 0;
255   }
256 
257   static class Container3 {
258     Value3 val;
259   }
260 
261   static Container3 getNullContainer3() {
262     return null;
263   }
264 
265   public static void test3() {
266     NullPointerException npe = null;
267     Container3 c = getNullContainer3();
268     try {
269       Value3 v = c.val;
270     } catch(NullPointerException e) {
271       npe = e;
272     }
273     Asserts.assertNotNull(npe);
274   }
275 
276   public static void main(String[] args) {
277     // All tests are run twice to exercise both the unresolved bytecodes and the rewritten ones
278     for (int i = 0; i < 2; i++) {
279       System.out.println("Pass " + i);
280       test0();
281       test1();
282       test2();
283       test3();
284     }
285   }
286 }