4 import java.util.zip.*;
5 import org.apache.bcel.*;
6 import org.apache.bcel.generic.*;
7 import org.apache.bcel.classfile.*;
8 import org.apache.bcel.util.*;
10 // Reachability rules:
12 // - a constructor is reachable iff it is called
13 // - a static method is reachable iff it is called
14 // - a nonstatic method is reachable
15 // - a static field is reachable iff it is referenced
16 // - a nonstatic field is reachable iff it is referenced
17 // - <clinit> is reachable iff any methods, static methods, fields, or constructors are reachable
19 // - if a method is reachable, all the methods it overrides are reachable
21 // try eliminating instance methods/fields if no ctor is reachable...
22 // distinguish between overloaded forms of a given method
23 // slim down the set of loadAllMethod() classes
26 // FIXME: nonstatic method invocation or field access implies that object will be constructed (ie hint)
28 public class BytecodePruner {
30 public static final boolean deleteMethods = false;
33 public static SyntheticRepository repo = null;
35 public static HashSet dest = new HashSet();
37 public static String outdir = ".";
39 public void loadAllMethods(String classname) throws Exception {
40 visitJavaClass(repo.loadClass(classname));
41 Method[] meths = getMethods(repo.loadClass(classname));
42 for(int i=0; i<meths.length; i++) visitJavaMethod(repo.loadClass(classname), meths[i]);
44 public void loadMethod(String classAndMethodName) throws Exception {
45 String classname = classAndMethodName.substring(0, classAndMethodName.lastIndexOf('.'));
46 String methodname = classAndMethodName.substring(classAndMethodName.lastIndexOf('.') + 1);
47 visitJavaClass(repo.loadClass(classname));
48 Method[] meths = getMethods(repo.loadClass(classname));
49 for(int i=0; i<meths.length; i++)
50 if (meths[i].getName().equals(methodname))
51 visitJavaMethod(repo.loadClass(classname), meths[i]);
53 public static void main(String[] s) throws Exception {
55 if (s.length >= 3 && s[1].equals("-o")) { outdir = s[2]; start += 2; }
56 repo = SyntheticRepository.getInstance(new ClassPath(s[0]));
58 BytecodePruner bcp = new BytecodePruner();
59 for(int i=start; i<s.length; i++) {
61 if (s[i].endsWith(".class")) {
62 bcp.visitJavaClass(repo.loadClass(s[i].substring(0, s[i].length() - 6)));
64 JavaClass cl = repo.loadClass(s[i].substring(0, s[i].lastIndexOf('.')));;
65 bcp.visitJavaClass(cl);
66 Method[] meths = getMethods(cl);
67 for(int j=0; j<meths.length; j++) {
68 if (meths[j].getName().equals(s[i].substring(s[i].lastIndexOf('.') + 1)))
69 bcp.visitJavaMethod(cl, meths[j]);
72 } catch (Exception e) {
73 System.out.println("WARNING: couldn't load class for " + s[i]);
77 System.out.println("\n\n======================================================================\n");
79 // we call start(), but the VM calls run()...
80 bcp.loadMethod("java.lang.Thread.run");
81 bcp.loadAllMethods("java.lang.SecurityContext");
82 bcp.visitJavaClass(repo.loadClass("java.awt.AWTPermission"));
83 bcp.visitJavaClass(repo.loadClass("gnu.classpath.Configuration"));
84 bcp.loadAllMethods("java.lang.ThreadDeath");
86 bcp.loadAllMethods("java.util.Hashtable$HashIterator");
87 bcp.loadMethod("java.util.SimpleTimeZone.useDaylightTime");
89 bcp.loadAllMethods("java.lang.Throwable");
90 bcp.loadAllMethods("java.io.PrintStream");
91 bcp.loadAllMethods("java.util.PropertyPermission");
92 bcp.loadAllMethods("java.security.cert.Certificate");
93 bcp.loadAllMethods("java.security.cert.CertificateEncodingException");
94 bcp.loadMethod("java.util.TimeZone.getAvailableIDs");
95 bcp.loadMethod("java.util.TimeZone.getDefaultTimeZoneId");
96 bcp.loadAllMethods("gnu.gcj.runtime.StringBuffer");
97 bcp.loadAllMethods("gnu.gcj.runtime.VMClassLoader");
98 bcp.visitJavaClass(repo.loadClass("gnu.gcj.runtime.JNIWeakRef"));
101 bcp.visitJavaClass(repo.loadClass("gnu.gcj.protocol.http.Handler"));
102 bcp.visitJavaClass(repo.loadClass("gnu.gcj.protocol.file.Handler"));
103 bcp.visitJavaClass(repo.loadClass("gnu.gcj.protocol.jar.Handler"));
104 bcp.visitJavaClass(repo.loadClass("gnu.gcj.protocol.core.Handler"));
106 bcp.visitJavaClass(repo.loadClass("gnu.gcj.runtime.FinalizerThread"));
107 bcp.visitJavaClass(repo.loadClass("gnu.gcj.runtime.FirstThread"));
109 // SecurityManager hacks to avoid java.security?
110 // URL and all descendents? Probably impossible.
111 // ObjectInput/ObjectOutput? Serialization?
113 // often called from native subclasses....
114 bcp.loadAllMethods("org.ibex.Surface");
115 bcp.loadAllMethods("org.ibex.Template$TemplateHelper$1");
116 bcp.loadAllMethods("org.ibex.Surface$DoubleBufferedSurface");
117 bcp.loadAllMethods("org.ibex.Surface$3");
118 bcp.loadAllMethods("org.ibex.Surface$2");
119 bcp.loadAllMethods("org.ibex.Picture");
120 bcp.loadAllMethods("org.ibex.PixelBuffer");
121 bcp.loadAllMethods("org.ibex.Platform");
122 bcp.loadAllMethods("org.ibex.Scheduler");
123 bcp.loadAllMethods("org.ibex.plat.X11");
124 bcp.loadAllMethods("org.ibex.plat.X11$X11Picture");
125 bcp.loadAllMethods("org.ibex.plat.X11$X11PixelBuffer");
126 bcp.loadAllMethods("org.ibex.plat.X11$X11Surface");
127 bcp.loadAllMethods("org.ibex.XMLRPC");
129 bcp.loadAllMethods("java.util.Date");
130 bcp.loadAllMethods("java.text.DateFormat");
131 bcp.loadAllMethods("java.text.NumberFormat");
134 Method[] meths = getMethods(repo.loadClass("org.ibex.plat.Linux"));
135 for(int i=0; i<meths.length; i++) {
136 if (meths[i].getName().equals("main"))
137 bcp.visitJavaMethod(repo.loadClass("org.ibex.plat.Linux"), meths[i]);
139 System.out.println();
141 System.out.println("Dumping...");
143 StringTokenizer st = new StringTokenizer(s[0], ":");
144 while(st.hasMoreTokens()) {
145 ZipFile zf = new ZipFile(st.nextToken());
146 Enumeration e = zf.entries();
147 while(e.hasMoreElements()) {
148 String ss = ((ZipEntry)e.nextElement()).getName();
149 if (!ss.endsWith(".class")) continue;
150 ss = ss.substring(0, ss.length() - 6);
151 ss = ss.replace('/', '.');
152 dump(repo.loadClass(ss));
157 public BytecodePruner() { }
159 public static void dump(JavaClass clazz) throws Exception {
160 if (clazz.getClassName().startsWith("java.sql.")) return;
161 if (!dest.contains(clazz)) return;
163 ConstantPoolGen newcpg = new ConstantPoolGen(clazz.getConstantPool());
164 ClassGen cg = new ClassGen(clazz);
165 InstructionFactory factory = new InstructionFactory(cg, newcpg);
168 cg.setConstantPool(newcpg);
169 Field[] fields = clazz.getFields();
171 for(int i=0; i<fields.length; i++)
172 if (!dest.contains(fields[i]) && false) {
173 System.out.println(" pruning " + clazz.getClassName() + "." + fields[i].getName());
177 // superprune: URLClassLoader, convert.In/Output other than needed, unneeded locales
178 // reflective metadata is killing us...
180 Method[] methods = getMethods(clazz);
182 boolean good = false;
183 for(int i=0; i<methods.length; i++)
184 if (clazz.getClassName().startsWith("gnu.gcj.runtime.")
185 || clazz.getClassName().startsWith("java.io.FileDescriptor")
186 || clazz.getClassName().startsWith("org.ibex.")
187 || clazz.getClassName().startsWith("java.lang.")) {
189 } else if (dest.contains(methods[i])) {
190 if (!methods[i].getName().equals("<clinit>")) good = true;
192 if (methods[i].getCode() == null) {
193 System.out.println(" empty codeblock: " + clazz.getClassName() + "." + methods[i].getName());
195 System.out.println(" pruning " + clazz.getClassName() + "." + methods[i].getName());
196 if (!deleteMethods) {
197 MethodGen mg = new MethodGen(methods[i], clazz.getClassName(), newcpg);
198 mg.removeExceptions();
199 InstructionList il = new InstructionList();
200 mg.setInstructionList(il);
202 InstructionHandle ih_0 = il.append(factory.createNew("java.lang.UnsatisfiedLinkError"));
203 il.append(InstructionConstants.DUP);
204 il.append(factory.createInvoke("java.lang.UnsatisfiedLinkError",
205 "<init>", Type.VOID, Type.NO_ARGS, Constants.INVOKESPECIAL));
206 il.append(InstructionConstants.ATHROW);
210 mg.removeExceptions();
211 mg.removeLocalVariables();
212 mg.removeExceptionHandlers();
213 mg.removeLineNumbers();
215 cg.replaceMethod(methods[i], mg.getMethod());
218 cg.removeMethod(methods[i]);
222 if ((clazz.getClassName().startsWith("gnu.java.locale.LocaleInformation") &&
223 !clazz.getClassName().endsWith("LocaleInformation_en") &&
224 !clazz.getClassName().endsWith("LocaleInformation") &&
225 !clazz.getClassName().endsWith("LocaleInformation_en_US"))
227 ((clazz.getClassName().startsWith("gnu.gcj.convert.Input_") ||
228 clazz.getClassName().startsWith("gnu.gcj.convert.Output_")) &&
229 !(clazz.getClassName().endsWith("ASCII") ||
230 clazz.getClassName().endsWith("UTF8") ||
231 clazz.getClassName().endsWith("iconv") ||
232 clazz.getClassName().endsWith("8859_1")))
235 !clazz.isInterface() &&
236 !clazz.isAbstract() &&
237 !clazz.getClassName().startsWith("java.io.") &&
238 !clazz.getClassName().startsWith("java.lang.") &&
239 !clazz.getClassName().startsWith("gnu.") &&
240 !clazz.getClassName().endsWith("Error") &&
241 !clazz.getClassName().endsWith("Exception") &&
242 !clazz.getClassName().endsWith("Permission"))) {
244 //System.out.println("DROPPING " + clazz.getClassName());
247 new File(outdir + "/" + new File(clazz.getClassName().replace('.', '/')).getParent()).mkdirs();
248 System.out.println("dumping " + clazz.getClassName());
249 cg.getJavaClass().dump(outdir + "/" + clazz.getClassName().replace('.', '/') + ".class");
252 public JavaClass sig2class(String sig) throws Exception {
253 if (sig == null) return null;
254 while (sig.length() > 0 && (sig.charAt(0) == 'L' || sig.charAt(0) == '[')) {
255 if (sig.charAt(0) == 'L') sig = sig.substring(1, sig.length() - 1);
256 else if (sig.charAt(0) == '[') sig = sig.substring(1, sig.length());
258 if (sig.length() <= 1) return null;
259 if (sig.equals("<null object>")) return null;
260 if (sig.startsWith("<return address")) return null;
261 return repo.loadClass(sig);
263 public void load(String sig) throws Exception {
264 if (sig == null) return;
265 while (sig.length() > 0 && (sig.charAt(0) == 'L' || sig.charAt(0) == '[')) {
266 if (sig.charAt(0) == 'L') sig = sig.substring(1, sig.length() - 1);
267 else if (sig.charAt(0) == '[') sig = sig.substring(1, sig.length());
269 if (sig.length() <= 1) return;
270 if (sig.equals("<null object>")) return;
271 if (sig.startsWith("<return address")) return;
272 visitJavaClass(repo.loadClass(sig));
274 public void load(Type t) throws Exception {
275 if (t == null) return;
276 //String sig = t.getSignature();
277 if (t instanceof ArrayType) load(((ArrayType)t).getElementType());
278 if (!(t instanceof ObjectType)) return;
279 load(((ObjectType)t).getClassName());
282 // hashtable of hashsets
283 public static Hashtable subclasses = new Hashtable();
285 public String getMethodSignature(Method m, ConstantPoolGen cpg) throws Exception {
286 return m.getName() + m.getSignature();
289 public String getMethodSignature(InvokeInstruction ii, ConstantPoolGen cpg) throws Exception {
291 Type[] argtypes = ii.getArgumentTypes(cpg);
292 for(int j=0; j<argtypes.length; j++) sig += argtypes[j].getSignature();
293 return ii.getMethodName(cpg) + "(" + sig + ")" + ii.getReturnType(cpg).getSignature();
296 public static int level = 0;
297 public void visitJavaMethod(JavaClass jc, Method method) throws Exception {
299 if (jc.getClassName().equals("java.util.Date") && method.getName().equals("readObject")) return;
300 //if (jc.getClassName().equals("java.net.URLClassLoader")) return;
301 if (jc.getClassName().indexOf("SharedLib") != -1) return;
302 if (jc.getClassName().indexOf("Datagram") != -1) return;
303 if (dest.contains(method)) return;
306 for(int i=0; i<level; i++) System.out.print(" ");
307 ConstantPoolGen cpg = new ConstantPoolGen(method.getConstantPool());
308 System.out.println(jc.getClassName() + "." + getMethodSignature(method, cpg));
309 markMethodInSubclasses(jc, method, cpg);
310 if (method.getCode() == null) { level -= 2; return; }
311 byte[] code = method.getCode().getCode();
312 InstructionList il = new InstructionList(code);
313 Instruction[] instructions = il.getInstructions();
314 for(int i=0; i<instructions.length; i++){
315 Instruction instr = instructions[i];
316 if (instr instanceof LoadClass) load(((LoadClass)instr).getLoadClassType(cpg));
317 if (instr instanceof CPInstruction) load(((CPInstruction)instr).getType(cpg));
318 if (instr instanceof InvokeInstruction) {
319 InvokeInstruction ii = (InvokeInstruction)instr;
320 String ii_sig = getMethodSignature(ii, cpg);
321 JavaClass c = sig2class(ii.getLoadClassType(cpg).getSignature());
322 load(ii.getReturnType(cpg));
323 load(ii.getType(cpg));
324 Method[] meths = getMethods(c);
325 boolean good = false;
326 for(int i2=0; i2<meths.length; i2++) {
327 if (getMethodSignature(meths[i2], cpg).equals(ii_sig)) {
328 visitJavaMethod(c, meths[i2]);
333 if (!good) throw new Exception("couldn't find method " + getMethodSignature(ii, cpg) + " in " + c.getClassName());
337 load(method.getReturnType());
338 Type[] argtypes = method.getArgumentTypes();
339 for(int i=0; i<argtypes.length; i++) load(argtypes[i]);
340 if (method.getExceptionTable() != null) {
341 String[] exntypes = method.getExceptionTable().getExceptionNames();
342 for(int i=0; i<exntypes.length; i++) load(exntypes[i]);
346 public void visitJavaField(Field field) throws Exception {
347 if (dest.contains(field)) return;
349 load(field.getType());
352 public void visitJavaClass(JavaClass clazz) throws Exception {
354 if (clazz.getClassName().startsWith("java.security.") &&
355 !clazz.getClassName().equals("java.security.cert.Certificate")) return;
357 if (dest.contains(clazz)) return;
360 ConstantPoolGen cpg = new ConstantPoolGen(clazz.getConstantPool());
361 String name = clazz.getClassName();
362 System.out.println(clazz.getClassName() + ".class");
364 JavaClass superclass = clazz.getSuperClass();
365 JavaClass[] interfaces = clazz.getAllInterfaces();
366 for(JavaClass sup = superclass; sup != null; sup = sup.getSuperClass()) {
367 if (subclasses.get(sup) == null) subclasses.put(sup, new HashSet());
368 ((HashSet)subclasses.get(sup)).add(clazz);
370 for(int i=0; i<interfaces.length; i++) {
371 if (subclasses.get(interfaces[i]) == null) subclasses.put(interfaces[i], new HashSet());
372 ((HashSet)subclasses.get(interfaces[i])).add(clazz);
375 if (clazz.getClassName().startsWith("org.ibex."))
376 loadAllMethods(clazz.getClassName());
378 for(JavaClass sup = superclass; sup != null; sup = sup.getSuperClass()) {
380 remarkMethods(sup, clazz, cpg);
382 for(int i=0; i<interfaces.length; i++) {
383 visitJavaClass(interfaces[i]);
384 remarkMethods(interfaces[i], clazz, cpg);
387 Field[] fields = clazz.getFields();
388 Method[] methods = getMethods(clazz);
389 for(int i=0; i<fields.length; i++) visitJavaField(fields[i]);
390 for(int i=0; i<methods.length; i++) {
391 if (methods[i].getName().equals("<clinit>")) visitJavaMethod(clazz, methods[i]);
393 // only if ctor reachable (?)
394 if (methods[i].getName().equals("equals")) visitJavaMethod(clazz, methods[i]);
395 if (methods[i].getName().equals("hashCode")) visitJavaMethod(clazz, methods[i]);
396 if (methods[i].getName().equals("finalize")) visitJavaMethod(clazz, methods[i]);
397 if (methods[i].getName().equals("clone")) visitJavaMethod(clazz, methods[i]);
398 if (methods[i].getName().equals("toString")) visitJavaMethod(clazz, methods[i]);
402 public void markMethodInSubclasses(JavaClass c, Method m, JavaClass subclass, ConstantPoolGen cpg) throws Exception {
403 if (m.isStatic()) return;
404 String sig = getMethodSignature(m, cpg);
405 Method[] submethods = getMethods(subclass);
406 for(int j=0; j<submethods.length; j++)
407 if (getMethodSignature(submethods[j], cpg).equals(sig))
408 visitJavaMethod(subclass, submethods[j]);
410 public void markMethodInSubclasses(JavaClass c, Method m, ConstantPoolGen cpg) throws Exception {
411 if (m.isStatic()) return;
412 HashSet s = (HashSet)subclasses.get(c);
413 if (s == null) return;
414 Object[] subclasses = s.toArray();
415 for(int i=0; i<subclasses.length; i++) {
416 JavaClass subclass = (JavaClass)subclasses[i];
417 for(int j=0; j<level; j++) System.out.print(" ");
418 System.out.println(" [subclass " + subclass.getClassName() + "]");
419 if (subclass == c) return;
420 markMethodInSubclasses(c, m, subclass, cpg);
424 public void remarkMethods(JavaClass c, ConstantPoolGen cpg) throws Exception {
425 Method[] meths =getMethods(c);
426 for(int j=0; j<meths.length; j++) if (dest.contains(meths[j])) markMethodInSubclasses(c, meths[j], cpg);
429 public void remarkMethods(JavaClass c, JavaClass target, ConstantPoolGen cpg) throws Exception {
430 Method[] meths = getMethods(c);
431 for(int j=0; j<meths.length; j++) if (dest.contains(meths[j])) markMethodInSubclasses(c, meths[j], target, cpg);
434 public static Hashtable methodsHashtable = new Hashtable();
435 public static Method[] getMethods(JavaClass c) {
436 Method[] ret = (Method[])methodsHashtable.get(c);
437 if (ret == null) methodsHashtable.put(c, ret = c.getMethods());