Mercurial > hg > graal-jvmci-8
diff agent/make/ClosureFinder.java @ 0:a61af66fc99e jdk7-b24
Initial load
author | duke |
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date | Sat, 01 Dec 2007 00:00:00 +0000 |
parents | |
children | c18cbe5936b8 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/agent/make/ClosureFinder.java Sat Dec 01 00:00:00 2007 +0000 @@ -0,0 +1,254 @@ +/* + * Copyright 2003-2004 Sun Microsystems, Inc. All Rights Reserved. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, + * CA 95054 USA or visit www.sun.com if you need additional information or + * have any questions. + * + */ + +import java.io.*; +import java.util.*; + + +/** +<p> This class finds transitive closure of dependencies from a given +root set of classes. If your project has lots of .class files and you +want to ship only those .class files which are used (transitively) +from a root set of classes, then you can use this utility. </p> <p> +How does it work?</p> + +<p> We walk through all constant pool entries of a given class and +find all modified UTF-8 entries. Anything that looks like a class name is +considered as a class and we search for that class in the given +classpath. If we find a .class of that name, then we add that class to +list.</p> + +<p> We could have used CONSTANT_ClassInfo type constants only. But +that will miss classes used through Class.forName or xyz.class +construct. But, if you refer to a class name in some other string we +would include it as dependency :(. But this is quite unlikely +anyway. To look for exact Class.forName argument(s) would involve +bytecode analysis. Also, we handle only simple reflection. If you +accept name of a class from externally (for eg properties file or +command line args for example, this utility will not be able to find +that dependency. In such cases, include those classes in the root set. +</p> +*/ + +public class ClosureFinder { + private Collection roots; // root class names Collection<String> + private Map visitedClasses; // set of all dependencies as a Map + private String classPath; // classpath to look for .class files + private String[] pathComponents; // classpath components + private static final boolean isWindows = File.separatorChar != '/'; + + public ClosureFinder(Collection roots, String classPath) { + this.roots = roots; + this.classPath = classPath; + parseClassPath(); + } + + // parse classPath into pathComponents array + private void parseClassPath() { + List paths = new ArrayList(); + StringTokenizer st = new StringTokenizer(classPath, File.pathSeparator); + while (st.hasMoreTokens()) + paths.add(st.nextToken()); + + Object[] arr = paths.toArray(); + pathComponents = new String[arr.length]; + System.arraycopy(arr, 0, pathComponents, 0, arr.length); + } + + // if output is aleady not computed, compute it now + // result is a map from class file name to base path where the .class was found + public Map find() { + if (visitedClasses == null) { + visitedClasses = new HashMap(); + computeClosure(); + } + return visitedClasses; + } + + // compute closure for all given root classes + private void computeClosure() { + for (Iterator rootsItr = roots.iterator(); rootsItr.hasNext();) { + String name = (String) rootsItr.next(); + name = name.substring(0, name.indexOf(".class")); + computeClosure(name); + } + } + + + // looks up for .class in pathComponents and returns + // base path if found, else returns null + private String lookupClassFile(String classNameAsPath) { + for (int i = 0; i < pathComponents.length; i++) { + File f = new File(pathComponents[i] + File.separator + + classNameAsPath + ".class"); + if (f.exists()) { + if (isWindows) { + String name = f.getName(); + // Windows reports special devices AUX,NUL,CON as files + // under any directory. It does not care about file extention :-( + if (name.compareToIgnoreCase("AUX.class") == 0 || + name.compareToIgnoreCase("NUL.class") == 0 || + name.compareToIgnoreCase("CON.class") == 0) { + return null; + } + } + return pathComponents[i]; + } + } + return null; + } + + + // from JVM spec. 2'nd edition section 4.4 + private static final int CONSTANT_Class = 7; + private static final int CONSTANT_FieldRef = 9; + private static final int CONSTANT_MethodRef = 10; + private static final int CONSTANT_InterfaceMethodRef = 11; + private static final int CONSTANT_String = 8; + private static final int CONSTANT_Integer = 3; + private static final int CONSTANT_Float = 4; + private static final int CONSTANT_Long = 5; + private static final int CONSTANT_Double = 6; + private static final int CONSTANT_NameAndType = 12; + private static final int CONSTANT_Utf8 = 1; + + // whether a given string may be a class name? + private boolean mayBeClassName(String internalClassName) { + int len = internalClassName.length(); + for (int s = 0; s < len; s++) { + char c = internalClassName.charAt(s); + if (!Character.isJavaIdentifierPart(c) && c != '/') + return false; + } + return true; + } + + // compute closure for a given class + private void computeClosure(String className) { + if (visitedClasses.get(className) != null) return; + String basePath = lookupClassFile(className); + if (basePath != null) { + visitedClasses.put(className, basePath); + try { + File classFile = new File(basePath + File.separator + className + ".class"); + FileInputStream fis = new FileInputStream(classFile); + DataInputStream dis = new DataInputStream(fis); + // look for .class signature + if (dis.readInt() != 0xcafebabe) { + System.err.println(classFile.getAbsolutePath() + " is not a valid .class file"); + return; + } + + // ignore major and minor version numbers + dis.readShort(); + dis.readShort(); + + // read number of constant pool constants + int numConsts = (int) dis.readShort(); + String[] strings = new String[numConsts]; + + // zero'th entry is unused + for (int cpIndex = 1; cpIndex < numConsts; cpIndex++) { + int constType = (int) dis.readByte(); + switch (constType) { + case CONSTANT_Class: + case CONSTANT_String: + dis.readShort(); // string name index; + break; + + case CONSTANT_FieldRef: + case CONSTANT_MethodRef: + case CONSTANT_InterfaceMethodRef: + case CONSTANT_NameAndType: + case CONSTANT_Integer: + case CONSTANT_Float: + // all these are 4 byte constants + dis.readInt(); + break; + + case CONSTANT_Long: + case CONSTANT_Double: + // 8 byte constants + dis.readLong(); + // occupies 2 cp entries + cpIndex++; + break; + + + case CONSTANT_Utf8: { + strings[cpIndex] = dis.readUTF(); + break; + } + + default: + System.err.println("invalid constant pool entry"); + return; + } + } + + // now walk thru the string constants and look for class names + for (int s = 0; s < numConsts; s++) { + if (strings[s] != null && mayBeClassName(strings[s])) + computeClosure(strings[s].replace('/', File.separatorChar)); + } + + } catch (IOException exp) { + // ignore for now + } + + } + } + + // a sample main that accepts roots classes in a file and classpath as args + public static void main(String[] args) { + if (args.length != 2) { + System.err.println("Usage: ClosureFinder <root class file> <class path>"); + System.exit(1); + } + + List roots = new ArrayList(); + try { + FileInputStream fis = new FileInputStream(args[0]); + DataInputStream dis = new DataInputStream(fis); + String line = null; + while ((line = dis.readLine()) != null) { + if (isWindows) { + line = line.replace('/', File.separatorChar); + } + roots.add(line); + } + } catch (IOException exp) { + System.err.println(exp.getMessage()); + System.exit(2); + } + + ClosureFinder cf = new ClosureFinder(roots, args[1]); + Map out = cf.find(); + Iterator res = out.keySet().iterator(); + for(; res.hasNext(); ) { + String className = (String) res.next(); + System.out.println(className + ".class"); + } + } +}