1 /* 2 * Copyright (c) 2016, 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 package runtime.valhalla.valuetypes; 25 26 import java.lang.invoke.*; 27 import jdk.experimental.value.*; 28 import jdk.test.lib.*; 29 import static jdk.test.lib.Asserts.*; 30 31 /* 32 * @test VWithFieldTest 33 * @summary vwithfield bytecode test 34 * @library /testlibrary / 35 * @run main/othervm -noverify -Xint runtime.valhalla.valuetypes.VWithFieldTest 36 */ 37 38 public class VWithFieldTest { 39 40 static __ByValue final class Point { 41 final private int x; 42 final private int y; 43 44 __ValueFactory static Point make(int x, int y) { 45 Point p = __MakeDefault Point(); 46 Asserts.assertEquals(p.x, 0, "invalid x default value"); 47 Asserts.assertEquals(p.y, 0, "invalid y default value"); 48 p.x = x; 49 Asserts.assertEquals(p.x, x, "invalid x value"); 50 Asserts.assertEquals(p.y, 0, "invalid y value"); 51 p.y = y; 52 Asserts.assertEquals(p.x, x, "invalid x value"); 53 Asserts.assertEquals(p.y, y, "invalid y value"); 54 return p; 55 } 56 57 Point () { 58 x = 0; 59 y = 0; 60 } 61 62 public int getX() { 63 return x; 64 } 65 66 __ValueFactory static Point setX(Point p, int x) { 67 p.x = x; 68 return p; 69 } 70 71 public int getY() { 72 return y; 73 } 74 75 __ValueFactory static Point setY(Point p, int y) { 76 p.y = y; 77 return p; 78 } 79 } 80 81 public static void main(String[] args) { 82 witherViaVvt(); 83 witherViaAnonymousClass(); 84 witherViaMvt(); 85 } 86 87 static void witherViaVvt() { 88 creationTest(); 89 witherTest(); 90 } 91 92 static void creationTest() { 93 Point p = Point.make(10,20); 94 Asserts.assertEquals(p.x, 10, "invalid x value"); 95 Asserts.assertEquals(p.y, 20, "invalid y value"); 96 } 97 98 static void witherTest() { 99 Point p1 = Point.make(2,12); 100 Asserts.assertEquals(p1.x, 2, "invalid x value"); 101 Asserts.assertEquals(p1.y, 12, "invalid y value"); 102 Point p2 = Point.setX(p1,3); 103 Asserts.assertEquals(p2.x, 3, "invalid x value"); 104 Asserts.assertEquals(p2.y, 12, "invalid y value"); 105 Point p3 = Point.setY(p2, 14); 106 Asserts.assertEquals(p3.x, 3, "invalid x value"); 107 Asserts.assertEquals(p3.y, 14, "invalid y value"); 108 } 109 110 111 @jvm.internal.value.DeriveValueType 112 static final class PointVcc { 113 // "package-private" access: Test access from anonymous class 114 // "final": Test vwithfield opcode issued from outside the (DVT) class 115 final int x; 116 final int y; 117 118 private PointVcc(int x, int y) { 119 this.x = x; 120 this.y = y; 121 } 122 123 /** 124 * MVT fields are final by definition, want to maintain full control of field values 125 * ACC_FINAL states only the code that owns the fields may do this. 126 * 127 * MVT needs a small hole, whereby the lookup klass->host_class == VCC, may modify 128 * DVT klass->derive_value_type_klass(). See: LinkResolver::resolve_field(). 129 * 130 * But we are still left with this ugly code pattern, i.e. the method handle lookup 131 * must be VCC..."ugly" but enforces the semantics of ACC_FINAL. 132 * 133 * ValueType.findWither() risks breaking code wishing to maintain value invariants, 134 * by exposing the wither method handle to arbitrary code. 135 * 136 * - There appears to be a discrepancy between the ValueType.findWither() API and 137 * "Shady Values" document. Missing "Class<?> refc" (see MethodHandles.Lookup.findSetter()). 138 * It could be argued that this dependency on hiding "refc" is too weak/dangerous. 139 */ 140 public static MethodHandle dvtCreator() { 141 Class<?> dvtClass = (Class<?>) ValueType.forClass(PointVcc.class).valueClass(); 142 return MethodHandleBuilder. 143 loadCode(MethodHandles.lookup(), 144 "vdefaultWithXWithY", 145 MethodType.methodType(dvtClass, Integer.TYPE, Integer.TYPE), 146 CODE-> { 147 CODE 148 .vdefault(dvtClass) 149 .iload(0) 150 .vwithfield(dvtClass, "x", "I") 151 .iload(1) 152 .vwithfield(dvtClass, "y", "I") 153 .vreturn(); 154 }); 155 } 156 157 public String toString() { 158 return "x=" + x + " y=" + y; 159 } 160 } 161 162 static void witherViaAnonymousClass() { 163 try { 164 Class<?> vccClass = (Class<?>) PointVcc.class; 165 ValueType<?> vt = ValueType.forClass(vccClass); 166 Class<?> dvtClass = vt.valueClass(); 167 168 int x = 7; 169 int y = 4711; 170 171 MethodHandle boxMh = MethodHandleBuilder. 172 loadCode(MethodHandles.lookup(), 173 "boxPointVcc", 174 MethodType.methodType(vccClass, dvtClass), 175 CODE-> { CODE.vload(0).vbox(vccClass).areturn(); }); 176 PointVcc point = (PointVcc) MethodHandles.filterReturnValue(PointVcc.dvtCreator(), 177 boxMh).invoke(x, y); 178 assertTrue(point.x == x); 179 assertTrue(point.y == y); 180 181 try { // Try to modify final fields from another class, should fail... 182 PointVcc apoint = (PointVcc) MethodHandleBuilder. 183 loadCode(MethodHandles.lookup(), 184 "vdefaultWithXWithY", 185 MethodType.methodType(vccClass, Integer.TYPE, Integer.TYPE), 186 CODE-> { 187 CODE 188 .vdefault(dvtClass) 189 .iload(0) 190 .vwithfield(dvtClass, "x", "I") 191 .iload(1) 192 .vwithfield(dvtClass, "y", "I") 193 .vbox(vccClass) 194 .areturn(); 195 }).invoke(x, y); 196 throw new RuntimeException("Expected IllegalAccessError"); 197 } 198 catch (IllegalAccessError illAccErr) {} 199 } 200 catch (Throwable t) { 201 throw new RuntimeException("witherViaAnonymousClass", t); 202 } 203 } 204 205 static void witherViaMvt() { 206 try { 207 Class<?> vccClass = (Class<?>) PointVcc.class; 208 ValueType<?> vt = ValueType.forClass(vccClass); 209 Class<?> dvtClass = vt.valueClass(); 210 211 int x = 4711; 212 int y = 13; 213 214 MethodHandle defValue = vt.defaultValueConstant(); 215 MethodHandle setX = vt.findWither("x", Integer.TYPE); 216 MethodHandle setY = vt.findWither("y", Integer.TYPE); 217 MethodHandle boxValue = vt.box(); 218 219 // Chain these VT methods up to be "VT.defaultValueConstant().setX(x).setY(y).box()"... 220 MethodHandle createX = MethodHandles.collectArguments(setX, 0, defValue); 221 MethodHandle updateY = MethodHandles.collectArguments(setY, 0, createX); 222 MethodHandle boxed = MethodHandles.filterReturnValue(updateY, boxValue); 223 224 PointVcc point = (PointVcc) boxed.invoke(x, y); 225 assertTrue(point.x == x); 226 assertTrue(point.y == y); 227 } 228 catch (Throwable t) { 229 throw new RuntimeException("witherViaMvt", t); 230 } 231 } 232 }