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. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25 package valhalla.shady;
26
27 import jdk.experimental.bytecode.BasicClassBuilder;
28 import jdk.internal.misc.Unsafe;
29 import jdk.internal.misc.VM;
30 import sun.security.action.GetPropertyAction;
31
32 import java.io.BufferedOutputStream;
33 import java.io.File;
34 import java.io.IOException;
35 import java.io.OutputStream;
36 import java.nio.file.Files;
37 import java.nio.file.Path;
38 import java.nio.file.Paths;
39 import java.security.ProtectionDomain;
40 import java.util.Properties;
41
42 import static jdk.internal.org.objectweb.asm.Opcodes.*;
43
44 import jdk.internal.misc.JavaLangAccess;
45 import jdk.internal.misc.SharedSecrets;
46 public class MinimalValueTypes_1_0 {
47
48 public static final int V53_1 = 1 << 16 | 53;
49 public static final int ACC_VALUE = ACC_NATIVE;
50 public static final String OBJECT_CLASS_DESC = "java/lang/Object";
51 public static final String VALUE_CLASS_DESC = "java/lang/__Value";
52
53 public static final String DERIVE_VALUE_TYPE_DESC = "Ljvm/internal/value/ValueCapableClass;";
54 public static final String DERIVE_VT_CLASSNAME_POSTFIX = "$Value";
55 public static final int DERIVE_VT_CLASS_ACCESS = ACC_PUBLIC|ACC_SUPER|ACC_FINAL|ACC_VALUE|ACC_SYNTHETIC;
56
57 public static final boolean DUMP_CLASS_FILES;
58 private static final boolean VALUE_TYPE_ENABLED;
59 private static final JavaLangAccess JLA;
60
61 static {
62 // Use same property as in j.l.invoke.MethodHandleStatics
63 Properties props = GetPropertyAction.privilegedGetProperties();
64 DUMP_CLASS_FILES = Boolean.parseBoolean(
65 props.getProperty("java.lang.invoke.MethodHandle.DUMP_CLASS_FILES"));
66
67 VALUE_TYPE_ENABLED = Boolean.parseBoolean(
68 props.getProperty("valhalla.enableValueType"));
69
70 JLA = SharedSecrets.getJavaLangAccess();
71 }
72
73 public static String getValueTypeClassName(ValueTypeDesc valueTypeDesc) {
74 return getValueTypeClassName(valueTypeDesc.getName());
75 }
76
77 public static String getValueTypeClassName(String vccName) {
78 return vccName + DERIVE_VT_CLASSNAME_POSTFIX;
79 }
80
81 public static String getValueCapableClassName(String valName) {
82 return valName.substring(0, valName.length() - DERIVE_VT_CLASSNAME_POSTFIX.length());
83 }
84
85 public static boolean isValueType(Class<?> dvt) {
86 return (dvt.getModifiers() & ACC_VALUE) != 0;
87 }
88
89 public static boolean isValueCapable(Class<?> vcc) {
90 return vcc.getDeclaredAnnotation(jvm.internal.value.ValueCapableClass.class) != null;
91 }
92
93 public static Class<?> getValueCapableClass(Class<?> dvt) {
94 if (!isValueType(dvt)) {
95 throw new IllegalArgumentException(dvt + " is not a derived value type");
96 }
97
98 Class<?> c = Class.forName(dvt.getModule(), getValueCapableClassName(dvt.getName()));
99 if (c == null || !isValueCapable(c)) {
100 throw new InternalError(dvt + " not bound to ValueType");
101 }
102 return c;
103 }
104
105 public static Class<?> getValueTypeClass(Class<?> vcc) {
106 if (!isValueCapable(vcc)) {
107 throw new IllegalArgumentException(vcc + " is not a value capable class");
108 }
109 return loadValueTypeClass(vcc, getValueTypeClassName(vcc.getName()));
110 }
111
112 public static Class<?> loadValueTypeClass(Class<?> vcc, String className) {
113 if (!isValueCapable(vcc)) {
114 throw new IllegalArgumentException(vcc.getName() + " is not a value capable class");
115 }
116 return JLA.loadValueTypeClass(vcc.getModule(), vcc.getClassLoader(), className);
117 }
118
119 /**
120 * This method is invoked by the VM.
121 *
122 * @param fds : name/sig pairs
123 * @param fmods : field modifiers
124 */
125 public static String createDerivedValueType(String vccInternalClassName,
126 ClassLoader cl,
127 ProtectionDomain pd,
128 String[] fds,
129 int[] fmods) {
130 String vtInternalClassName = getValueTypeClassName(vccInternalClassName);
131 ValueTypeDesc valueTypeDesc = new ValueTypeDesc(vccInternalClassName, fds, fmods);
132 byte[] valueTypeBytes = createValueType(valueTypeDesc);
133 Class<?> vtClass = Unsafe.getUnsafe().defineClass(vtInternalClassName, valueTypeBytes, 0, valueTypeBytes.length, cl, pd);
134 return vtInternalClassName;
135 }
136
137 public static byte[] createValueType(ValueTypeDesc valueTypeDesc) {
138
139 String valueTypeClassName = getValueTypeClassName(valueTypeDesc);
140
141 BasicClassBuilder builder = new BasicClassBuilder(mangleValueClassName(valueTypeClassName), 53, 1)
142 .withFlags(DERIVE_VT_CLASS_ACCESS)
143 .withSuperclass(mangleValueClassName(VALUE_CLASS_DESC));
144
145 ValueTypeDesc.Field[] fields = valueTypeDesc.getFields();
146 for (ValueTypeDesc.Field field : fields) {
147 builder.withField(field.name, field.type, F -> F.withFlags(field.modifiers));
148 }
149
150 byte[] newBytes = builder.build();
151 maybeDump(valueTypeClassName, newBytes);
152 return newBytes;
153 }
154
155 /** debugging flag for saving generated class files */
156 private static final Path DUMP_CLASS_FILES_DIR;
157
158 static {
159 if (DUMP_CLASS_FILES) {
160 try {
161 Path dumpDir = Paths.get("DUMP_CLASS_FILES");
162 Files.createDirectories(dumpDir);
163 DUMP_CLASS_FILES_DIR = dumpDir;
164 } catch (Exception e) {
165 throw new InternalError(e);
166 }
167 } else {
168 DUMP_CLASS_FILES_DIR = null;
169 }
170 }
171
172 public static void maybeDump(final String className, final byte[] classFile) {
173 if (DUMP_CLASS_FILES_DIR != null) {
174 java.security.AccessController.doPrivileged(
175 new java.security.PrivilegedAction<>() {
176 public Void run() {
177 String dumpName = className;
178 //dumpName = dumpName.replace('/', '-');
179 Path dumpFile = DUMP_CLASS_FILES_DIR.resolve(dumpName + ".class");
180 File root = dumpFile.getParent().toFile();
181 if (!root.exists() && !root.mkdirs()) {
182 throw new IllegalStateException("Could not create dump file directory: " + root);
183 }
184 System.out.println("dump: " + dumpFile);
185 try (OutputStream os = Files.newOutputStream(dumpFile);
186 BufferedOutputStream bos = new BufferedOutputStream(os)) {
187 bos.write(classFile);
188 } catch (IOException ex) {
189 throw new InternalError(ex);
190 }
191 return null;
192 }
193 });
194
195 }
196 }
197
198 private final native Class<?> getDerivedValueType(Class<?> ofClass);
199
200 public static Class<?> getValueClass() {
201 return VALUE_TYPE_ENABLED ? ValueClassHolder.CLASS_OBJECT : null;
202 }
203
204 public static String mangleValueClassName(String name) {
205 return ";Q" + name + ";";
206 }
207
208 /*
209 * A holder class that references __Value to be loaded only when MVT is enabled.
210 *
211 * This holder class would fail verification if loaded if MVT is not enabled.
212 */
213 private static class ValueClassHolder {
214 static final Class<?> CLASS_OBJECT =
215 (Class<?>)(Object)__Value.class; //hack around static type-system checks
216 }
217 }