1 /*
2 * Copyright (c) 2013, 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 jdk.test.lib;
25
26 import java.io.ByteArrayOutputStream;
27 import java.io.IOException;
28 import java.io.OutputStream;
29
30 import java.net.URI;
31 import java.util.ArrayList;
32 import java.util.Arrays;
33 import java.util.List;
34
35 import javax.tools.ForwardingJavaFileManager;
36 import javax.tools.FileObject;
37 import javax.tools.JavaCompiler;
38 import javax.tools.JavaCompiler.CompilationTask;
39 import javax.tools.JavaFileObject;
40 import javax.tools.JavaFileObject.Kind;
41 import javax.tools.SimpleJavaFileObject;
42 import javax.tools.StandardLocation;
43 import javax.tools.ToolProvider;
44
45 /**
46 * {@code InMemoryJavaCompiler} can be used for compiling a {@link
47 * CharSequence} to a {@code byte[]}.
48 *
49 * The compiler will not use the file system at all, instead using a {@link
50 * ByteArrayOutputStream} for storing the byte code. For the source code, any
51 * kind of {@link CharSequence} can be used, e.g. {@link String}, {@link
52 * StringBuffer} or {@link StringBuilder}.
53 *
54 * The {@code InMemoryCompiler} can easily be used together with a {@code
55 * ByteClassLoader} to easily compile and load source code in a {@link String}:
56 *
57 * <pre>
58 * {@code
59 * import jdk.test.lib.InMemoryJavaCompiler;
60 * import jdk.test.lib.ByteClassLoader;
61 *
62 * class Example {
63 * public static void main(String[] args) {
64 * String className = "Foo";
65 * String sourceCode = "public class " + className + " {" +
66 * " public void bar() {" +
67 * " System.out.println("Hello from bar!");" +
68 * " }" +
69 * "}";
70 * byte[] byteCode = InMemoryJavaCompiler.compile(className, sourceCode);
71 * Class fooClass = ByteClassLoader.load(className, byteCode);
72 * }
73 * }
74 * }
75 * </pre>
76 */
77 public class InMemoryJavaCompiler {
78 private static class MemoryJavaFileObject extends SimpleJavaFileObject {
79 private final String className;
80 private final CharSequence sourceCode;
81 private final ByteArrayOutputStream byteCode;
82
83 public MemoryJavaFileObject(String className, CharSequence sourceCode) {
84 super(URI.create("string:///" + className.replace('.','/') + Kind.SOURCE.extension), Kind.SOURCE);
85 this.className = className;
86 this.sourceCode = sourceCode;
87 this.byteCode = new ByteArrayOutputStream();
88 }
89
90 @Override
91 public CharSequence getCharContent(boolean ignoreEncodingErrors) {
92 return sourceCode;
93 }
94
95 @Override
96 public OutputStream openOutputStream() throws IOException {
97 return byteCode;
98 }
99
100 public byte[] getByteCode() {
101 return byteCode.toByteArray();
102 }
103
104 public String getClassName() {
105 return className;
106 }
107 }
108
109 private static class FileManagerWrapper extends ForwardingJavaFileManager {
110 private static final Location PATCH_LOCATION = new Location() {
111 @Override
112 public String getName() {
113 return "patch module location";
114 }
115
116 @Override
117 public boolean isOutputLocation() {
118 return false;
119 }
120 };
121 private final MemoryJavaFileObject file;
122 private final String moduleOverride;
123
124 public FileManagerWrapper(MemoryJavaFileObject file, String moduleOverride) {
125 super(getCompiler().getStandardFileManager(null, null, null));
126 this.file = file;
127 this.moduleOverride = moduleOverride;
128 }
129
130 @Override
131 public JavaFileObject getJavaFileForOutput(Location location, String className,
132 Kind kind, FileObject sibling)
133 throws IOException {
134 if (!file.getClassName().equals(className)) {
135 throw new IOException("Expected class with name " + file.getClassName() +
136 ", but got " + className);
137 }
138 return file;
139 }
140
141 @Override
142 public Location getLocationForModule(Location location, JavaFileObject fo, String pkgName) throws IOException {
143 if (fo == file && moduleOverride != null) {
144 return PATCH_LOCATION;
145 }
146 return super.getLocationForModule(location, fo, pkgName);
147 }
148
149 @Override
150 public String inferModuleName(Location location) throws IOException {
151 if (location == PATCH_LOCATION) {
152 return moduleOverride;
153 }
154 return super.inferModuleName(location);
155 }
156
157 @Override
158 public boolean hasLocation(Location location) {
159 return super.hasLocation(location) || location == StandardLocation.PATCH_MODULE_PATH;
160 }
161
162 }
163
164 /**
165 * Compiles the class with the given name and source code.
166 *
167 * @param className The name of the class
168 * @param sourceCode The source code for the class with name {@code className}
169 * @param options additional command line options
170 * @throws RuntimeException if the compilation did not succeed
171 * @return The resulting byte code from the compilation
172 */
173 public static byte[] compile(String className, CharSequence sourceCode, String... options) {
174 MemoryJavaFileObject file = new MemoryJavaFileObject(className, sourceCode);
175 CompilationTask task = getCompilationTask(file, options);
176
177 if(!task.call()) {
178 throw new RuntimeException("Could not compile " + className + " with source code " + sourceCode);
179 }
180
181 return file.getByteCode();
182 }
183
184 private static JavaCompiler getCompiler() {
185 return ToolProvider.getSystemJavaCompiler();
186 }
187
188 private static CompilationTask getCompilationTask(MemoryJavaFileObject file, String... options) {
189 List<String> opts = new ArrayList<>();
190 String moduleOverride = null;
191 for (String opt : options) {
192 if (opt.startsWith("-Xmodule:")) {
193 moduleOverride = opt.substring("-Xmodule:".length());
194 } else {
195 opts.add(opt);
196 }
197 }
198 return getCompiler().getTask(null, new FileManagerWrapper(file, moduleOverride), null, opts, null, Arrays.asList(file));
199 }
200 }