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]);
45 public void loadField(String classAndMethodName) throws Exception {
46 String classname = classAndMethodName.substring(0, classAndMethodName.lastIndexOf('.'));
47 String methodname = classAndMethodName.substring(classAndMethodName.lastIndexOf('.') + 1);
48 visitJavaClass(repo.loadClass(classname));
49 Field[] meths = repo.loadClass(classname).getFields();
50 for(int i=0; i<meths.length; i++)
51 if (meths[i].getName().equals(methodname))
52 visitJavaField(meths[i]);
56 public void loadMethod(String classAndMethodName) throws Exception {
57 String classname = classAndMethodName.substring(0, classAndMethodName.lastIndexOf('.'));
58 String methodname = classAndMethodName.substring(classAndMethodName.lastIndexOf('.') + 1);
59 visitJavaClass(repo.loadClass(classname));
60 Method[] meths = getMethods(repo.loadClass(classname));
61 for(int i=0; i<meths.length; i++)
62 if (meths[i].getName().equals(methodname))
63 visitJavaMethod(repo.loadClass(classname), meths[i]);
65 public static void main(String[] s) throws Exception {
67 if (s.length >= 3 && s[1].equals("-o")) { outdir = s[2]; start += 2; }
68 repo = SyntheticRepository.getInstance(new ClassPath(s[0]));
70 BytecodePruner bcp = new BytecodePruner();
71 for(int i=start; i<s.length; i++) {
73 if (s[i].endsWith(".class")) {
74 bcp.visitJavaClass(repo.loadClass(s[i].substring(0, s[i].length() - 6)));
76 JavaClass cl = repo.loadClass(s[i].substring(0, s[i].lastIndexOf('.')));;
77 bcp.visitJavaClass(cl);
78 Method[] meths = getMethods(cl);
79 for(int j=0; j<meths.length; j++) {
80 if (meths[j].getName().equals(s[i].substring(s[i].lastIndexOf('.') + 1)))
81 bcp.visitJavaMethod(cl, meths[j]);
84 } catch (Exception e) {
85 System.out.println("WARNING: couldn't load class for " + s[i]);
89 System.out.println("\n\n======================================================================\n");
91 // we call start(), but the VM calls run()...
92 bcp.loadMethod("java.lang.Thread.run");
93 bcp.loadAllMethods("java.lang.SecurityContext");
94 bcp.visitJavaClass(repo.loadClass("java.awt.AWTPermission"));
95 bcp.visitJavaClass(repo.loadClass("gnu.classpath.Configuration"));
96 bcp.loadAllMethods("java.lang.ThreadDeath");
98 bcp.loadAllMethods("java.util.Hashtable$HashIterator");
99 bcp.loadMethod("java.util.SimpleTimeZone.useDaylightTime");
101 bcp.loadAllMethods("java.lang.Throwable");
102 bcp.loadAllMethods("java.io.PrintStream");
103 bcp.loadAllMethods("java.util.PropertyPermission");
104 bcp.loadAllMethods("java.security.cert.Certificate");
105 bcp.loadAllMethods("java.security.cert.CertificateEncodingException");
106 bcp.loadMethod("java.util.TimeZone.getAvailableIDs");
107 bcp.loadMethod("java.util.TimeZone.getDefaultTimeZoneId");
108 bcp.loadAllMethods("gnu.gcj.runtime.StringBuffer");
109 bcp.loadAllMethods("gnu.gcj.runtime.VMClassLoader");
110 bcp.visitJavaClass(repo.loadClass("gnu.gcj.runtime.JNIWeakRef"));
113 bcp.visitJavaClass(repo.loadClass("gnu.gcj.protocol.http.Handler"));
114 bcp.visitJavaClass(repo.loadClass("gnu.gcj.protocol.file.Handler"));
115 bcp.visitJavaClass(repo.loadClass("gnu.gcj.protocol.jar.Handler"));
116 bcp.visitJavaClass(repo.loadClass("gnu.gcj.protocol.core.Handler"));
118 bcp.visitJavaClass(repo.loadClass("gnu.gcj.runtime.FinalizerThread"));
119 bcp.visitJavaClass(repo.loadClass("gnu.gcj.runtime.FirstThread"));
121 // SecurityManager hacks to avoid java.security?
122 // URL and all descendents? Probably impossible.
123 // ObjectInput/ObjectOutput? Serialization?
125 // often called from native subclasses....
126 bcp.loadAllMethods("org.ibex.Surface");
127 bcp.loadAllMethods("org.ibex.Template$TemplateHelper$1");
128 bcp.loadAllMethods("org.ibex.Surface$DoubleBufferedSurface");
129 bcp.loadAllMethods("org.ibex.Surface$3");
130 bcp.loadAllMethods("org.ibex.Surface$2");
131 bcp.loadAllMethods("org.ibex.Picture");
132 bcp.loadAllMethods("org.ibex.PixelBuffer");
133 bcp.loadAllMethods("org.ibex.Platform");
134 bcp.loadAllMethods("org.ibex.Scheduler");
135 bcp.loadAllMethods("org.ibex.plat.X11");
136 bcp.loadAllMethods("org.ibex.plat.X11$X11Picture");
137 bcp.loadAllMethods("org.ibex.plat.X11$X11PixelBuffer");
138 bcp.loadAllMethods("org.ibex.plat.X11$X11Surface");
139 bcp.loadAllMethods("org.ibex.XMLRPC");
141 bcp.loadAllMethods("java.util.Date");
142 bcp.loadAllMethods("java.text.DateFormat");
143 bcp.loadAllMethods("java.text.NumberFormat");
146 Method[] meths = getMethods(repo.loadClass("org.ibex.plat.Linux"));
147 for(int i=0; i<meths.length; i++) {
148 if (meths[i].getName().equals("main"))
149 bcp.visitJavaMethod(repo.loadClass("org.ibex.plat.Linux"), meths[i]);
151 System.out.println();
153 System.out.println("Dumping...");
155 StringTokenizer st = new StringTokenizer(s[0], ":");
156 while(st.hasMoreTokens()) {
157 ZipFile zf = new ZipFile(st.nextToken());
158 Enumeration e = zf.entries();
159 while(e.hasMoreElements()) {
160 String ss = ((ZipEntry)e.nextElement()).getName();
161 if (!ss.endsWith(".class")) continue;
162 ss = ss.substring(0, ss.length() - 6);
163 ss = ss.replace('/', '.');
164 dump(repo.loadClass(ss));
169 public BytecodePruner() { }
171 public static void dump(JavaClass clazz) throws Exception {
172 if (clazz.getClassName().startsWith("java.sql.")) return;
173 if (!dest.contains(clazz)) return;
175 ConstantPoolGen newcpg = new ConstantPoolGen(clazz.getConstantPool());
176 ClassGen cg = new ClassGen(clazz);
177 InstructionFactory factory = new InstructionFactory(cg, newcpg);
180 cg.setConstantPool(newcpg);
181 Field[] fields = clazz.getFields();
183 for(int i=0; i<fields.length; i++)
184 if (!dest.contains(fields[i]) && false) {
185 System.out.println(" pruning " + clazz.getClassName() + "." + fields[i].getName());
189 // superprune: URLClassLoader, convert.In/Output other than needed, unneeded locales
190 // reflective metadata is killing us...
192 Method[] methods = getMethods(clazz);
194 boolean good = false;
195 for(int i=0; i<methods.length; i++)
196 if (clazz.getClassName().startsWith("gnu.gcj.runtime.")
197 || clazz.getClassName().startsWith("java.io.FileDescriptor")
198 || clazz.getClassName().startsWith("org.ibex.")
199 || clazz.getClassName().startsWith("java.lang.")) {
201 } else if (dest.contains(methods[i])) {
202 if (!methods[i].getName().equals("<clinit>")) good = true;
204 if (methods[i].getCode() == null) {
205 System.out.println(" empty codeblock: " + clazz.getClassName() + "." + methods[i].getName());
207 System.out.println(" pruning " + clazz.getClassName() + "." + methods[i].getName());
208 if (!deleteMethods) {
209 MethodGen mg = new MethodGen(methods[i], clazz.getClassName(), newcpg);
210 mg.removeExceptions();
211 InstructionList il = new InstructionList();
212 mg.setInstructionList(il);
214 InstructionHandle ih_0 = il.append(factory.createNew("java.lang.UnsatisfiedLinkError"));
215 il.append(InstructionConstants.DUP);
216 il.append(factory.createInvoke("java.lang.UnsatisfiedLinkError",
217 "<init>", Type.VOID, Type.NO_ARGS, Constants.INVOKESPECIAL));
218 il.append(InstructionConstants.ATHROW);
222 mg.removeExceptions();
223 mg.removeLocalVariables();
224 mg.removeExceptionHandlers();
225 mg.removeLineNumbers();
227 cg.replaceMethod(methods[i], mg.getMethod());
230 cg.removeMethod(methods[i]);
234 if ((clazz.getClassName().startsWith("gnu.java.locale.LocaleInformation") &&
235 !clazz.getClassName().endsWith("LocaleInformation_en") &&
236 !clazz.getClassName().endsWith("LocaleInformation") &&
237 !clazz.getClassName().endsWith("LocaleInformation_en_US"))
239 ((clazz.getClassName().startsWith("gnu.gcj.convert.Input_") ||
240 clazz.getClassName().startsWith("gnu.gcj.convert.Output_")) &&
241 !(clazz.getClassName().endsWith("ASCII") ||
242 clazz.getClassName().endsWith("UTF8") ||
243 clazz.getClassName().endsWith("iconv") ||
244 clazz.getClassName().endsWith("8859_1")))
247 !clazz.isInterface() &&
248 !clazz.isAbstract() &&
249 !clazz.getClassName().startsWith("java.io.") &&
250 !clazz.getClassName().startsWith("java.lang.") &&
251 !clazz.getClassName().startsWith("gnu.") &&
252 !clazz.getClassName().endsWith("Error") &&
253 !clazz.getClassName().endsWith("Exception") &&
254 !clazz.getClassName().endsWith("Permission"))) {
256 //System.out.println("DROPPING " + clazz.getClassName());
259 new File(outdir + "/" + new File(clazz.getClassName().replace('.', '/')).getParent()).mkdirs();
260 System.out.println("dumping " + clazz.getClassName());
261 cg.getJavaClass().dump(outdir + "/" + clazz.getClassName().replace('.', '/') + ".class");
264 public JavaClass sig2class(String sig) throws Exception {
265 if (sig == null) return null;
266 while (sig.length() > 0 && (sig.charAt(0) == 'L' || sig.charAt(0) == '[')) {
267 if (sig.charAt(0) == 'L') sig = sig.substring(1, sig.length() - 1);
268 else if (sig.charAt(0) == '[') sig = sig.substring(1, sig.length());
270 if (sig.length() <= 1) return null;
271 if (sig.equals("<null object>")) return null;
272 if (sig.startsWith("<return address")) return null;
273 return repo.loadClass(sig);
275 public void load(String sig) throws Exception {
276 if (sig == null) return;
277 while (sig.length() > 0 && (sig.charAt(0) == 'L' || sig.charAt(0) == '[')) {
278 if (sig.charAt(0) == 'L') sig = sig.substring(1, sig.length() - 1);
279 else if (sig.charAt(0) == '[') sig = sig.substring(1, sig.length());
281 if (sig.length() <= 1) return;
282 if (sig.equals("<null object>")) return;
283 if (sig.startsWith("<return address")) return;
284 visitJavaClass(repo.loadClass(sig));
286 public void load(Type t) throws Exception {
287 if (t == null) return;
288 //String sig = t.getSignature();
289 if (t instanceof ArrayType) load(((ArrayType)t).getElementType());
290 if (!(t instanceof ObjectType)) return;
291 load(((ObjectType)t).getClassName());
294 // hashtable of hashsets
295 public static Hashtable subclasses = new Hashtable();
297 public String getMethodSignature(Method m, ConstantPoolGen cpg) throws Exception {
298 return m.getName() + m.getSignature();
301 public String getMethodSignature(InvokeInstruction ii, ConstantPoolGen cpg) throws Exception {
303 Type[] argtypes = ii.getArgumentTypes(cpg);
304 for(int j=0; j<argtypes.length; j++) sig += argtypes[j].getSignature();
305 return ii.getMethodName(cpg) + "(" + sig + ")" + ii.getReturnType(cpg).getSignature();
308 public static int level = 0;
309 public void visitJavaMethod(JavaClass jc, Method method) throws Exception {
311 if (jc.getClassName().equals("java.util.Date") && method.getName().equals("readObject")) return;
312 //if (jc.getClassName().equals("java.net.URLClassLoader")) return;
313 if (jc.getClassName().indexOf("SharedLib") != -1) return;
314 if (jc.getClassName().indexOf("Datagram") != -1) return;
315 if (dest.contains(method)) return;
318 for(int i=0; i<level; i++) System.out.print(" ");
319 ConstantPoolGen cpg = new ConstantPoolGen(method.getConstantPool());
320 System.out.println(jc.getClassName() + "." + getMethodSignature(method, cpg));
321 markMethodInSubclasses(jc, method, cpg);
322 if (method.getCode() == null) { level -= 2; return; }
323 byte[] code = method.getCode().getCode();
324 InstructionList il = new InstructionList(code);
325 Instruction[] instructions = il.getInstructions();
326 for(int i=0; i<instructions.length; i++){
327 Instruction instr = instructions[i];
328 if (instr instanceof LoadClass) load(((LoadClass)instr).getLoadClassType(cpg));
329 if (instr instanceof CPInstruction) load(((CPInstruction)instr).getType(cpg));
330 if (instr instanceof InvokeInstruction) {
331 InvokeInstruction ii = (InvokeInstruction)instr;
332 String ii_sig = getMethodSignature(ii, cpg);
333 JavaClass c = sig2class(ii.getLoadClassType(cpg).getSignature());
334 load(ii.getReturnType(cpg));
335 load(ii.getType(cpg));
336 Method[] meths = getMethods(c);
337 boolean good = false;
338 for(int i2=0; i2<meths.length; i2++) {
339 if (getMethodSignature(meths[i2], cpg).equals(ii_sig)) {
340 visitJavaMethod(c, meths[i2]);
345 if (!good) throw new Exception("couldn't find method " + getMethodSignature(ii, cpg) + " in " + c.getClassName());
349 load(method.getReturnType());
350 Type[] argtypes = method.getArgumentTypes();
351 for(int i=0; i<argtypes.length; i++) load(argtypes[i]);
352 if (method.getExceptionTable() != null) {
353 String[] exntypes = method.getExceptionTable().getExceptionNames();
354 for(int i=0; i<exntypes.length; i++) load(exntypes[i]);
358 public void visitJavaField(Field field) throws Exception {
359 if (dest.contains(field)) return;
361 load(field.getType());
364 public void visitJavaClass(JavaClass clazz) throws Exception {
366 if (clazz.getClassName().startsWith("java.security.") &&
367 !clazz.getClassName().equals("java.security.cert.Certificate")) return;
369 if (dest.contains(clazz)) return;
372 ConstantPoolGen cpg = new ConstantPoolGen(clazz.getConstantPool());
373 String name = clazz.getClassName();
374 System.out.println(clazz.getClassName() + ".class");
376 JavaClass superclass = clazz.getSuperClass();
377 JavaClass[] interfaces = clazz.getAllInterfaces();
378 for(JavaClass sup = superclass; sup != null; sup = sup.getSuperClass()) {
379 if (subclasses.get(sup) == null) subclasses.put(sup, new HashSet());
380 ((HashSet)subclasses.get(sup)).add(clazz);
382 for(int i=0; i<interfaces.length; i++) {
383 if (subclasses.get(interfaces[i]) == null) subclasses.put(interfaces[i], new HashSet());
384 ((HashSet)subclasses.get(interfaces[i])).add(clazz);
387 if (clazz.getClassName().startsWith("org.ibex."))
388 loadAllMethods(clazz.getClassName());
390 for(JavaClass sup = superclass; sup != null; sup = sup.getSuperClass()) {
392 remarkMethods(sup, clazz, cpg);
394 for(int i=0; i<interfaces.length; i++) {
395 visitJavaClass(interfaces[i]);
396 remarkMethods(interfaces[i], clazz, cpg);
399 Field[] fields = clazz.getFields();
400 Method[] methods = getMethods(clazz);
401 for(int i=0; i<fields.length; i++) visitJavaField(fields[i]);
402 for(int i=0; i<methods.length; i++) {
403 if (methods[i].getName().equals("<clinit>")) visitJavaMethod(clazz, methods[i]);
405 // only if ctor reachable (?)
406 if (methods[i].getName().equals("equals")) visitJavaMethod(clazz, methods[i]);
407 if (methods[i].getName().equals("hashCode")) visitJavaMethod(clazz, methods[i]);
408 if (methods[i].getName().equals("finalize")) visitJavaMethod(clazz, methods[i]);
409 if (methods[i].getName().equals("clone")) visitJavaMethod(clazz, methods[i]);
410 if (methods[i].getName().equals("toString")) visitJavaMethod(clazz, methods[i]);
414 public void markMethodInSubclasses(JavaClass c, Method m, JavaClass subclass, ConstantPoolGen cpg) throws Exception {
415 if (m.isStatic()) return;
416 String sig = getMethodSignature(m, cpg);
417 Method[] submethods = getMethods(subclass);
418 for(int j=0; j<submethods.length; j++)
419 if (getMethodSignature(submethods[j], cpg).equals(sig))
420 visitJavaMethod(subclass, submethods[j]);
422 public void markMethodInSubclasses(JavaClass c, Method m, ConstantPoolGen cpg) throws Exception {
423 if (m.isStatic()) return;
424 HashSet s = (HashSet)subclasses.get(c);
425 if (s == null) return;
426 Object[] subclasses = s.toArray();
427 for(int i=0; i<subclasses.length; i++) {
428 JavaClass subclass = (JavaClass)subclasses[i];
429 for(int j=0; j<level; j++) System.out.print(" ");
430 System.out.println(" [subclass " + subclass.getClassName() + "]");
431 if (subclass == c) return;
432 markMethodInSubclasses(c, m, subclass, cpg);
436 public void remarkMethods(JavaClass c, ConstantPoolGen cpg) throws Exception {
437 Method[] meths =getMethods(c);
438 for(int j=0; j<meths.length; j++) if (dest.contains(meths[j])) markMethodInSubclasses(c, meths[j], cpg);
441 public void remarkMethods(JavaClass c, JavaClass target, ConstantPoolGen cpg) throws Exception {
442 Method[] meths = getMethods(c);
443 for(int j=0; j<meths.length; j++) if (dest.contains(meths[j])) markMethodInSubclasses(c, meths[j], target, cpg);
446 public static Hashtable methodsHashtable = new Hashtable();
447 public static Method[] getMethods(JavaClass c) {
448 Method[] ret = (Method[])methodsHashtable.get(c);
449 if (ret == null) methodsHashtable.put(c, ret = c.getMethods());