1 /*
2 * Copyright (c) 2023, 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
25 /*
26 * @test
27 * @enablePreview
28 * @run testng TestDereferencePath
29 */
30
31 import java.lang.foreign.Arena;
32 import java.lang.foreign.MemoryLayout;
33 import java.lang.foreign.MemoryLayout.PathElement;
34 import java.lang.foreign.MemorySegment;
35
36 import java.lang.foreign.ValueLayout;
37
38 import org.testng.annotations.*;
39
40 import java.lang.invoke.VarHandle;
41 import static org.testng.Assert.*;
42
43 public class TestDereferencePath {
44
45 static final MemoryLayout C = MemoryLayout.structLayout(
46 ValueLayout.JAVA_INT.withName("x")
47 );
48
49 static final MemoryLayout B = MemoryLayout.structLayout(
50 ValueLayout.ADDRESS.withName("c")
51 .withTargetLayout(C)
52 );
53
54 static final MemoryLayout A = MemoryLayout.structLayout(
55 ValueLayout.ADDRESS.withName("b")
56 .withTargetLayout(B)
57 );
58
59 static final VarHandle abcx = A.varHandle(
60 PathElement.groupElement("b"), PathElement.dereferenceElement(),
61 PathElement.groupElement("c"), PathElement.dereferenceElement(),
62 PathElement.groupElement("x"));
63
64 @Test
65 public void testSingle() {
66 try (Arena arena = Arena.ofConfined()) {
67 // init structs
68 MemorySegment a = arena.allocate(A);
69 MemorySegment b = arena.allocate(B);
70 MemorySegment c = arena.allocate(C);
71 // init struct fields
72 a.set(ValueLayout.ADDRESS, 0, b);
73 b.set(ValueLayout.ADDRESS, 0, c);
74 c.set(ValueLayout.JAVA_INT, 0, 42);
75 // dereference
76 int val = (int) abcx.get(a);
77 assertEquals(val, 42);
78 }
79 }
80
81 static final MemoryLayout B_MULTI = MemoryLayout.structLayout(
82 ValueLayout.ADDRESS.withName("cs")
83 .withTargetLayout(MemoryLayout.sequenceLayout(2, C))
84 );
85
86 static final MemoryLayout A_MULTI = MemoryLayout.structLayout(
87 ValueLayout.ADDRESS.withName("bs")
88 .withTargetLayout(MemoryLayout.sequenceLayout(2, B_MULTI))
89 );
90
91 static final VarHandle abcx_multi = A_MULTI.varHandle(
92 PathElement.groupElement("bs"), PathElement.dereferenceElement(), PathElement.sequenceElement(),
93 PathElement.groupElement("cs"), PathElement.dereferenceElement(), PathElement.sequenceElement(),
94 PathElement.groupElement("x"));
95
96 @Test
97 public void testMulti() {
98 try (Arena arena = Arena.ofConfined()) {
99 // init structs
100 MemorySegment a = arena.allocate(A);
101 MemorySegment b = arena.allocateArray(B, 2);
102 MemorySegment c = arena.allocateArray(C, 4);
103 // init struct fields
104 a.set(ValueLayout.ADDRESS, 0, b);
105 b.set(ValueLayout.ADDRESS, 0, c);
106 b.setAtIndex(ValueLayout.ADDRESS, 1, c.asSlice(C.byteSize() * 2));
107 c.setAtIndex(ValueLayout.JAVA_INT, 0, 1);
108 c.setAtIndex(ValueLayout.JAVA_INT, 1, 2);
109 c.setAtIndex(ValueLayout.JAVA_INT, 2, 3);
110 c.setAtIndex(ValueLayout.JAVA_INT, 3, 4);
111 // dereference
112 int val00 = (int) abcx_multi.get(a, 0, 0); // a->b[0]->c[0] = 1
113 assertEquals(val00, 1);
114 int val10 = (int) abcx_multi.get(a, 1, 0); // a->b[1]->c[0] = 3
115 assertEquals(val10, 3);
116 int val01 = (int) abcx_multi.get(a, 0, 1); // a->b[0]->c[1] = 2
117 assertEquals(val01, 2);
118 int val11 = (int) abcx_multi.get(a, 1, 1); // a->b[1]->c[1] = 4
119 assertEquals(val11, 4);
120 }
121 }
122
123 @Test(expectedExceptions = IllegalArgumentException.class)
124 void testBadDerefInSelect() {
125 A.select(PathElement.groupElement("b"), PathElement.dereferenceElement());
126 }
127
128 @Test(expectedExceptions = IllegalArgumentException.class)
129 void testBadDerefInOffset() {
130 A.byteOffset(PathElement.groupElement("b"), PathElement.dereferenceElement());
131 }
132
133 @Test(expectedExceptions = IllegalArgumentException.class)
134 void testBadDerefInSlice() {
135 A.sliceHandle(PathElement.groupElement("b"), PathElement.dereferenceElement());
136 }
137
138 static final MemoryLayout A_MULTI_NO_TARGET = MemoryLayout.structLayout(
139 ValueLayout.ADDRESS.withName("bs")
140 );
141
142 @Test(expectedExceptions = IllegalArgumentException.class)
143 void badDerefAddressNoTarget() {
144 A_MULTI_NO_TARGET.varHandle(PathElement.groupElement("bs"), PathElement.dereferenceElement());
145 }
146
147 @Test(expectedExceptions = IllegalArgumentException.class)
148 void badDerefMisAligned() {
149 MemoryLayout struct = MemoryLayout.structLayout(
150 ValueLayout.ADDRESS.withTargetLayout(ValueLayout.JAVA_INT).withName("x"));
151
152 try (Arena arena = Arena.ofConfined()) {
153 MemorySegment segment = arena.allocate(struct.byteSize() + 1).asSlice(1);
154 VarHandle vhX = struct.varHandle(PathElement.groupElement("x"), PathElement.dereferenceElement());
155 vhX.set(segment, 42); // should throw
156 }
157 }
158 }