1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/agent/make/ClosureFinder.java Sat Dec 01 00:00:00 2007 +0000
1.3 @@ -0,0 +1,254 @@
1.4 +/*
1.5 + * Copyright 2003-2004 Sun Microsystems, Inc. All Rights Reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation.
1.11 + *
1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 + * version 2 for more details (a copy is included in the LICENSE file that
1.16 + * accompanied this code).
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License version
1.19 + * 2 along with this work; if not, write to the Free Software Foundation,
1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 + *
1.22 + * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
1.23 + * CA 95054 USA or visit www.sun.com if you need additional information or
1.24 + * have any questions.
1.25 + *
1.26 + */
1.27 +
1.28 +import java.io.*;
1.29 +import java.util.*;
1.30 +
1.31 +
1.32 +/**
1.33 +<p> This class finds transitive closure of dependencies from a given
1.34 +root set of classes. If your project has lots of .class files and you
1.35 +want to ship only those .class files which are used (transitively)
1.36 +from a root set of classes, then you can use this utility. </p> <p>
1.37 +How does it work?</p>
1.38 +
1.39 +<p> We walk through all constant pool entries of a given class and
1.40 +find all modified UTF-8 entries. Anything that looks like a class name is
1.41 +considered as a class and we search for that class in the given
1.42 +classpath. If we find a .class of that name, then we add that class to
1.43 +list.</p>
1.44 +
1.45 +<p> We could have used CONSTANT_ClassInfo type constants only. But
1.46 +that will miss classes used through Class.forName or xyz.class
1.47 +construct. But, if you refer to a class name in some other string we
1.48 +would include it as dependency :(. But this is quite unlikely
1.49 +anyway. To look for exact Class.forName argument(s) would involve
1.50 +bytecode analysis. Also, we handle only simple reflection. If you
1.51 +accept name of a class from externally (for eg properties file or
1.52 +command line args for example, this utility will not be able to find
1.53 +that dependency. In such cases, include those classes in the root set.
1.54 +</p>
1.55 +*/
1.56 +
1.57 +public class ClosureFinder {
1.58 + private Collection roots; // root class names Collection<String>
1.59 + private Map visitedClasses; // set of all dependencies as a Map
1.60 + private String classPath; // classpath to look for .class files
1.61 + private String[] pathComponents; // classpath components
1.62 + private static final boolean isWindows = File.separatorChar != '/';
1.63 +
1.64 + public ClosureFinder(Collection roots, String classPath) {
1.65 + this.roots = roots;
1.66 + this.classPath = classPath;
1.67 + parseClassPath();
1.68 + }
1.69 +
1.70 + // parse classPath into pathComponents array
1.71 + private void parseClassPath() {
1.72 + List paths = new ArrayList();
1.73 + StringTokenizer st = new StringTokenizer(classPath, File.pathSeparator);
1.74 + while (st.hasMoreTokens())
1.75 + paths.add(st.nextToken());
1.76 +
1.77 + Object[] arr = paths.toArray();
1.78 + pathComponents = new String[arr.length];
1.79 + System.arraycopy(arr, 0, pathComponents, 0, arr.length);
1.80 + }
1.81 +
1.82 + // if output is aleady not computed, compute it now
1.83 + // result is a map from class file name to base path where the .class was found
1.84 + public Map find() {
1.85 + if (visitedClasses == null) {
1.86 + visitedClasses = new HashMap();
1.87 + computeClosure();
1.88 + }
1.89 + return visitedClasses;
1.90 + }
1.91 +
1.92 + // compute closure for all given root classes
1.93 + private void computeClosure() {
1.94 + for (Iterator rootsItr = roots.iterator(); rootsItr.hasNext();) {
1.95 + String name = (String) rootsItr.next();
1.96 + name = name.substring(0, name.indexOf(".class"));
1.97 + computeClosure(name);
1.98 + }
1.99 + }
1.100 +
1.101 +
1.102 + // looks up for .class in pathComponents and returns
1.103 + // base path if found, else returns null
1.104 + private String lookupClassFile(String classNameAsPath) {
1.105 + for (int i = 0; i < pathComponents.length; i++) {
1.106 + File f = new File(pathComponents[i] + File.separator +
1.107 + classNameAsPath + ".class");
1.108 + if (f.exists()) {
1.109 + if (isWindows) {
1.110 + String name = f.getName();
1.111 + // Windows reports special devices AUX,NUL,CON as files
1.112 + // under any directory. It does not care about file extention :-(
1.113 + if (name.compareToIgnoreCase("AUX.class") == 0 ||
1.114 + name.compareToIgnoreCase("NUL.class") == 0 ||
1.115 + name.compareToIgnoreCase("CON.class") == 0) {
1.116 + return null;
1.117 + }
1.118 + }
1.119 + return pathComponents[i];
1.120 + }
1.121 + }
1.122 + return null;
1.123 + }
1.124 +
1.125 +
1.126 + // from JVM spec. 2'nd edition section 4.4
1.127 + private static final int CONSTANT_Class = 7;
1.128 + private static final int CONSTANT_FieldRef = 9;
1.129 + private static final int CONSTANT_MethodRef = 10;
1.130 + private static final int CONSTANT_InterfaceMethodRef = 11;
1.131 + private static final int CONSTANT_String = 8;
1.132 + private static final int CONSTANT_Integer = 3;
1.133 + private static final int CONSTANT_Float = 4;
1.134 + private static final int CONSTANT_Long = 5;
1.135 + private static final int CONSTANT_Double = 6;
1.136 + private static final int CONSTANT_NameAndType = 12;
1.137 + private static final int CONSTANT_Utf8 = 1;
1.138 +
1.139 + // whether a given string may be a class name?
1.140 + private boolean mayBeClassName(String internalClassName) {
1.141 + int len = internalClassName.length();
1.142 + for (int s = 0; s < len; s++) {
1.143 + char c = internalClassName.charAt(s);
1.144 + if (!Character.isJavaIdentifierPart(c) && c != '/')
1.145 + return false;
1.146 + }
1.147 + return true;
1.148 + }
1.149 +
1.150 + // compute closure for a given class
1.151 + private void computeClosure(String className) {
1.152 + if (visitedClasses.get(className) != null) return;
1.153 + String basePath = lookupClassFile(className);
1.154 + if (basePath != null) {
1.155 + visitedClasses.put(className, basePath);
1.156 + try {
1.157 + File classFile = new File(basePath + File.separator + className + ".class");
1.158 + FileInputStream fis = new FileInputStream(classFile);
1.159 + DataInputStream dis = new DataInputStream(fis);
1.160 + // look for .class signature
1.161 + if (dis.readInt() != 0xcafebabe) {
1.162 + System.err.println(classFile.getAbsolutePath() + " is not a valid .class file");
1.163 + return;
1.164 + }
1.165 +
1.166 + // ignore major and minor version numbers
1.167 + dis.readShort();
1.168 + dis.readShort();
1.169 +
1.170 + // read number of constant pool constants
1.171 + int numConsts = (int) dis.readShort();
1.172 + String[] strings = new String[numConsts];
1.173 +
1.174 + // zero'th entry is unused
1.175 + for (int cpIndex = 1; cpIndex < numConsts; cpIndex++) {
1.176 + int constType = (int) dis.readByte();
1.177 + switch (constType) {
1.178 + case CONSTANT_Class:
1.179 + case CONSTANT_String:
1.180 + dis.readShort(); // string name index;
1.181 + break;
1.182 +
1.183 + case CONSTANT_FieldRef:
1.184 + case CONSTANT_MethodRef:
1.185 + case CONSTANT_InterfaceMethodRef:
1.186 + case CONSTANT_NameAndType:
1.187 + case CONSTANT_Integer:
1.188 + case CONSTANT_Float:
1.189 + // all these are 4 byte constants
1.190 + dis.readInt();
1.191 + break;
1.192 +
1.193 + case CONSTANT_Long:
1.194 + case CONSTANT_Double:
1.195 + // 8 byte constants
1.196 + dis.readLong();
1.197 + // occupies 2 cp entries
1.198 + cpIndex++;
1.199 + break;
1.200 +
1.201 +
1.202 + case CONSTANT_Utf8: {
1.203 + strings[cpIndex] = dis.readUTF();
1.204 + break;
1.205 + }
1.206 +
1.207 + default:
1.208 + System.err.println("invalid constant pool entry");
1.209 + return;
1.210 + }
1.211 + }
1.212 +
1.213 + // now walk thru the string constants and look for class names
1.214 + for (int s = 0; s < numConsts; s++) {
1.215 + if (strings[s] != null && mayBeClassName(strings[s]))
1.216 + computeClosure(strings[s].replace('/', File.separatorChar));
1.217 + }
1.218 +
1.219 + } catch (IOException exp) {
1.220 + // ignore for now
1.221 + }
1.222 +
1.223 + }
1.224 + }
1.225 +
1.226 + // a sample main that accepts roots classes in a file and classpath as args
1.227 + public static void main(String[] args) {
1.228 + if (args.length != 2) {
1.229 + System.err.println("Usage: ClosureFinder <root class file> <class path>");
1.230 + System.exit(1);
1.231 + }
1.232 +
1.233 + List roots = new ArrayList();
1.234 + try {
1.235 + FileInputStream fis = new FileInputStream(args[0]);
1.236 + DataInputStream dis = new DataInputStream(fis);
1.237 + String line = null;
1.238 + while ((line = dis.readLine()) != null) {
1.239 + if (isWindows) {
1.240 + line = line.replace('/', File.separatorChar);
1.241 + }
1.242 + roots.add(line);
1.243 + }
1.244 + } catch (IOException exp) {
1.245 + System.err.println(exp.getMessage());
1.246 + System.exit(2);
1.247 + }
1.248 +
1.249 + ClosureFinder cf = new ClosureFinder(roots, args[1]);
1.250 + Map out = cf.find();
1.251 + Iterator res = out.keySet().iterator();
1.252 + for(; res.hasNext(); ) {
1.253 + String className = (String) res.next();
1.254 + System.out.println(className + ".class");
1.255 + }
1.256 + }
1.257 +}
