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 // SecurityManager hacks to avoid java.security?
11 // URL and all descendents? Probably impossible.
12 // ObjectInput/ObjectOutput? Serialization?
14 // superprune: URLClassLoader, convert.In/Output other than needed, unneeded locales
15 // reflective metadata is killing us...
17 // Reachability rules:
19 // - a constructor is reachable iff it is called
20 // - a static method is reachable iff it is called
21 // - a nonstatic method is reachable
22 // - a static field is reachable iff it is referenced
23 // - a nonstatic field is reachable iff it is referenced
24 // - <clinit> is reachable iff any methods, static methods, fields, or constructors are reachable
26 // - if a method is reachable, all the methods it overrides are reachable
28 // try eliminating instance methods/fields if no ctor is reachable...
29 // distinguish between overloaded forms of a given method
30 // slim down the set of loadAllMethod() classes
33 // FIXME: nonstatic method invocation or field access implies that object will be constructed (ie hint)
35 public class BytecodePruner {
37 public static final boolean deleteMethods = false;
38 public static SyntheticRepository repo = null;
39 public static HashSet dest = new HashSet();
40 public static String outdir = ".";
42 public void loadAllMethods(String classname) throws Exception {
43 visitJavaClass(repo.loadClass(classname));
44 Method[] meths = getMethods(repo.loadClass(classname));
45 for(int i=0; i<meths.length; i++) visitJavaMethod(repo.loadClass(classname), meths[i]);
48 public void loadMethod(String classAndMethodName) throws Exception {
49 String classname = classAndMethodName.substring(0, classAndMethodName.lastIndexOf('.'));
50 String methodname = classAndMethodName.substring(classAndMethodName.lastIndexOf('.') + 1);
51 if (classname.endsWith("." + methodname)) methodname = "<init>";
52 visitJavaClass(repo.loadClass(classname));
53 Method[] meths = getMethods(repo.loadClass(classname));
54 for(int i=0; i<meths.length; i++)
55 if (meths[i].getName().equals(methodname))
56 visitJavaMethod(repo.loadClass(classname), meths[i]);
59 public static void main(String[] s) throws Exception {
60 BytecodePruner bcp = new BytecodePruner();
62 if (s.length >= 3 && s[1].equals("-o")) { outdir = s[2]; start += 2; }
63 repo = SyntheticRepository.getInstance(new ClassPath(s[0]));
64 for(int i=start; i<s.length; i++)
65 if (s[i].endsWith(".class")) bcp.visitJavaClass(repo.loadClass(s[i].substring(0, s[i].length() - 6)));
66 else bcp.loadMethod(s[i]);
68 bcp.loadMethod("java.lang.Thread.run"); // we call start(), but the VM calls run()...
69 bcp.loadAllMethods("gnu.gcj.runtime.StringBuffer"); // the compiler emits calls directly to this class
70 bcp.loadAllMethods("java.lang.SecurityContext");
71 bcp.loadAllMethods("java.lang.ThreadDeath");
72 bcp.visitJavaClass(repo.loadClass("java.awt.AWTPermission"));
73 bcp.visitJavaClass(repo.loadClass("gnu.classpath.Configuration"));
74 bcp.loadAllMethods("java.util.Hashtable$HashIterator");
75 bcp.loadMethod("java.util.SimpleTimeZone.useDaylightTime");
76 bcp.visitJavaClass(repo.loadClass("gnu.gcj.runtime.FinalizerThread"));
77 bcp.visitJavaClass(repo.loadClass("gnu.gcj.runtime.FirstThread"));
79 StringTokenizer st = new StringTokenizer(s[0], ":");
80 while(st.hasMoreTokens()) {
81 ZipFile zf = new ZipFile(st.nextToken());
82 Enumeration e = zf.entries();
83 while(e.hasMoreElements()) {
84 String ss = ((ZipEntry)e.nextElement()).getName();
85 if (!ss.endsWith(".class")) continue;
86 ss = ss.substring(0, ss.length() - 6);
87 ss = ss.replace('/', '.');
88 dump(repo.loadClass(ss));
93 public BytecodePruner() { }
95 public static void dump(JavaClass clazz) throws Exception {
96 if (clazz.getClassName().startsWith("java.sql.")) return;
97 if (!dest.contains(clazz)) return;
99 ConstantPoolGen newcpg = new ConstantPoolGen(clazz.getConstantPool());
100 ClassGen cg = new ClassGen(clazz);
101 cg.setConstantPool(newcpg);
102 InstructionFactory factory = new InstructionFactory(cg, newcpg);
106 Field[] fields = clazz.getFields();
108 for(int i=0; i<fields.length; i++)
109 if (!dest.contains(fields[i]) && false) {
110 System.out.println(" pruning " + clazz.getClassName() + "." + fields[i].getName());
114 Method[] methods = getMethods(clazz);
116 boolean good = false;
117 for(int i=0; i<methods.length; i++)
118 if (clazz.getClassName().startsWith("java.io.FileDescriptor")) {
120 } else if (dest.contains(methods[i])) {
121 if (!methods[i].getName().equals("<clinit>")) good = true;
123 if (methods[i].getCode() == null) {
124 System.out.println(" empty codeblock: " + clazz.getClassName() + "." + methods[i].getName());
126 System.out.println(" pruning " + clazz.getClassName() + "." + methods[i].getName());
127 if (!deleteMethods) {
128 MethodGen mg = new MethodGen(methods[i], clazz.getClassName(), newcpg);
129 mg.removeExceptions();
130 InstructionList il = new InstructionList();
131 mg.setInstructionList(il);
133 InstructionHandle ih_0 = il.append(factory.createNew("java.lang.UnsatisfiedLinkError"));
134 il.append(InstructionConstants.DUP);
135 il.append(factory.createInvoke("java.lang.UnsatisfiedLinkError",
136 "<init>", Type.VOID, Type.NO_ARGS, Constants.INVOKESPECIAL));
137 il.append(InstructionConstants.ATHROW);
141 mg.removeExceptions();
142 mg.removeLocalVariables();
143 mg.removeExceptionHandlers();
144 mg.removeLineNumbers();
146 cg.replaceMethod(methods[i], mg.getMethod());
149 cg.removeMethod(methods[i]);
153 if ((clazz.getClassName().startsWith("gnu.java.locale.LocaleInformation") &&
154 !clazz.getClassName().endsWith("LocaleInformation_en") &&
155 !clazz.getClassName().endsWith("LocaleInformation") &&
156 !clazz.getClassName().endsWith("LocaleInformation_en_US"))
158 ((clazz.getClassName().startsWith("gnu.gcj.convert.Input_") ||
159 clazz.getClassName().startsWith("gnu.gcj.convert.Output_")) &&
160 !(clazz.getClassName().endsWith("ASCII") ||
161 clazz.getClassName().endsWith("UTF8") ||
162 clazz.getClassName().endsWith("iconv") ||
163 clazz.getClassName().endsWith("8859_1")))
166 !clazz.isInterface() &&
167 !clazz.isAbstract() &&
168 !clazz.getClassName().startsWith("java.io.") &&
169 !clazz.getClassName().startsWith("java.lang.") &&
170 !clazz.getClassName().startsWith("gnu.") &&
171 !clazz.getClassName().endsWith("Error") &&
172 !clazz.getClassName().endsWith("Exception") &&
173 !clazz.getClassName().endsWith("Permission"))) {
175 //System.out.println("DROPPING " + clazz.getClassName());
178 new File(outdir + "/" + new File(clazz.getClassName().replace('.', '/')).getParent()).mkdirs();
179 System.out.println("dumping " + clazz.getClassName());
180 cg.getJavaClass().dump(outdir + "/" + clazz.getClassName().replace('.', '/') + ".class");
183 public JavaClass sig2class(String sig) throws Exception {
184 if (sig == null) return null;
185 while (sig.length() > 0 && (sig.charAt(0) == 'L' || sig.charAt(0) == '[')) {
186 if (sig.charAt(0) == 'L') sig = sig.substring(1, sig.length() - 1);
187 else if (sig.charAt(0) == '[') sig = sig.substring(1, sig.length());
189 if (sig.length() <= 1) return null;
190 if (sig.equals("<null object>")) return null;
191 if (sig.startsWith("<return address")) return null;
192 return repo.loadClass(sig);
194 public void load(String sig) throws Exception {
195 if (sig == null) return;
196 while (sig.length() > 0 && (sig.charAt(0) == 'L' || sig.charAt(0) == '[')) {
197 if (sig.charAt(0) == 'L') sig = sig.substring(1, sig.length() - 1);
198 else if (sig.charAt(0) == '[') sig = sig.substring(1, sig.length());
200 if (sig.length() <= 1) return;
201 if (sig.equals("<null object>")) return;
202 if (sig.startsWith("<return address")) return;
203 visitJavaClass(repo.loadClass(sig));
205 public void load(Type t) throws Exception {
206 if (t == null) return;
207 //String sig = t.getSignature();
208 if (t instanceof ArrayType) load(((ArrayType)t).getElementType());
209 if (!(t instanceof ObjectType)) return;
210 load(((ObjectType)t).getClassName());
213 // hashtable of hashsets
214 public static Hashtable subclasses = new Hashtable();
216 public String getMethodSignature(Method m, ConstantPoolGen cpg) throws Exception {
217 return m.getName() + m.getSignature();
220 public String getMethodSignature(InvokeInstruction ii, ConstantPoolGen cpg) throws Exception {
222 Type[] argtypes = ii.getArgumentTypes(cpg);
223 for(int j=0; j<argtypes.length; j++) sig += argtypes[j].getSignature();
224 return ii.getMethodName(cpg) + "(" + sig + ")" + ii.getReturnType(cpg).getSignature();
227 public static int level = 0;
228 public void visitJavaMethod(JavaClass jc, Method method) throws Exception {
230 if (jc.getClassName().equals("java.util.Date") && method.getName().equals("readObject")) return;
231 //if (jc.getClassName().equals("java.net.URLClassLoader")) return;
232 if (jc.getClassName().indexOf("SharedLib") != -1) return;
233 if (jc.getClassName().indexOf("Datagram") != -1) return;
234 if (dest.contains(method)) return;
237 for(int i=0; i<level; i++) System.out.print(" ");
238 ConstantPool cp = method.getConstantPool();
239 ConstantPoolGen cpg = new ConstantPoolGen(cp);
240 System.out.println(jc.getClassName() + "." + getMethodSignature(method, cpg));
241 markMethodInSubclasses(jc, method, cpg);
242 if (method.getCode() == null) { level -= 2; return; }
243 byte[] code = method.getCode().getCode();
244 InstructionList il = new InstructionList(code);
245 Instruction[] instructions = il.getInstructions();
246 for(int i=0; i<instructions.length; i++){
247 Instruction instr = instructions[i];
248 if (instr instanceof LoadClass) load(((LoadClass)instr).getLoadClassType(cpg));
249 if (instr instanceof CPInstruction) load(((CPInstruction)instr).getType(cpg));
250 if (instr instanceof InvokeInstruction) {
251 InvokeInstruction ii = (InvokeInstruction)instr;
252 String ii_sig = getMethodSignature(ii, cpg);
253 JavaClass c = sig2class(ii.getLoadClassType(cpg).getSignature());
254 load(ii.getReturnType(cpg));
255 load(ii.getType(cpg));
256 Method[] meths = getMethods(c);
257 boolean good = false;
258 for(int i2=0; i2<meths.length; i2++) {
259 if (getMethodSignature(meths[i2], cpg).equals(ii_sig)) {
260 visitJavaMethod(c, meths[i2]);
265 if (!good) throw new Exception("couldn't find method " + getMethodSignature(ii, cpg) + " in " + c.getClassName());
269 load(method.getReturnType());
270 Type[] argtypes = method.getArgumentTypes();
271 for(int i=0; i<argtypes.length; i++) load(argtypes[i]);
272 if (method.getExceptionTable() != null) {
273 String[] exntypes = method.getExceptionTable().getExceptionNames();
274 for(int i=0; i<exntypes.length; i++) load(exntypes[i]);
276 if (method.getCode() != null && method.getCode().getExceptionTable() != null) {
277 CodeException[] exntypes = method.getCode().getExceptionTable();
279 for(int i=0; i<exntypes.length; i++) {
280 int index = exntypes[i].getCatchType();
281 if (index == 0) continue;
282 load(Utility.compactClassName(cp.getConstantString(index, Constants.CONSTANT_Class), false));
287 public void visitJavaField(Field field) throws Exception {
288 if (dest.contains(field)) return;
290 load(field.getType());
293 public void visitJavaClass(JavaClass clazz) throws Exception {
295 if (clazz.getClassName().startsWith("java.security.") &&
296 !clazz.getClassName().equals("java.security.cert.Certificate")) return;
298 if (dest.contains(clazz)) return;
301 ConstantPoolGen cpg = new ConstantPoolGen(clazz.getConstantPool());
302 String name = clazz.getClassName();
303 System.out.println(clazz.getClassName() + ".class");
305 JavaClass superclass = clazz.getSuperClass();
306 for(JavaClass sup = clazz; sup != null; sup = sup.getSuperClass()) {
308 if (subclasses.get(sup) == null) subclasses.put(sup, new HashSet());
309 ((HashSet)subclasses.get(sup)).add(clazz);
311 JavaClass[] interfaces = sup.getAllInterfaces();
312 for(int i=0; i<interfaces.length; i++) {
313 if (subclasses.get(interfaces[i]) == null) subclasses.put(interfaces[i], new HashSet());
314 ((HashSet)subclasses.get(interfaces[i])).add(clazz);
318 if (clazz.getClassName().startsWith("org.ibex.")) loadAllMethods(clazz.getClassName());
320 for(JavaClass sup = clazz; sup != null; sup = sup.getSuperClass()) {
323 remarkMethods(sup, clazz, cpg);
325 JavaClass[] interfaces = sup.getAllInterfaces();
326 for(int i=0; i<interfaces.length; i++) {
327 visitJavaClass(interfaces[i]);
328 remarkMethods(interfaces[i], clazz, cpg);
332 Field[] fields = clazz.getFields();
333 Method[] methods = getMethods(clazz);
334 for(int i=0; i<fields.length; i++) visitJavaField(fields[i]);
335 for(int i=0; i<methods.length; i++) {
336 if (methods[i].getName().equals("<clinit>")) visitJavaMethod(clazz, methods[i]);
338 // only if ctor reachable (?)
339 if (methods[i].getName().equals("equals")) visitJavaMethod(clazz, methods[i]);
340 if (methods[i].getName().equals("hashCode")) visitJavaMethod(clazz, methods[i]);
341 if (methods[i].getName().equals("finalize")) visitJavaMethod(clazz, methods[i]);
342 if (methods[i].getName().equals("clone")) visitJavaMethod(clazz, methods[i]);
343 if (methods[i].getName().equals("toString")) visitJavaMethod(clazz, methods[i]);
347 public void markMethodInSubclasses(JavaClass c, Method m, JavaClass subclass, ConstantPoolGen cpg) throws Exception {
348 if (m.isStatic()) return;
349 String sig = getMethodSignature(m, cpg);
350 Method[] submethods = getMethods(subclass);
351 for(int j=0; j<submethods.length; j++)
352 //if (getMethodSignature(submethods[j], cpg).equals(sig))
353 if (submethods[j].getName().equals(m.getName()))
354 visitJavaMethod(subclass, submethods[j]);
356 public void markMethodInSubclasses(JavaClass c, Method m, ConstantPoolGen cpg) throws Exception {
357 if (m.isStatic()) return;
358 HashSet s = (HashSet)subclasses.get(c);
359 if (s == null) return;
360 Object[] subclasses = s.toArray();
361 for(int i=0; i<subclasses.length; i++) {
362 JavaClass subclass = (JavaClass)subclasses[i];
363 for(int j=0; j<level; j++) System.out.print(" ");
364 System.out.println(" [subclass " + subclass.getClassName() + "]");
365 if (subclass == c) return;
366 markMethodInSubclasses(c, m, subclass, cpg);
370 public void remarkMethods(JavaClass c, ConstantPoolGen cpg) throws Exception {
371 Method[] meths =getMethods(c);
372 for(int j=0; j<meths.length; j++) if (dest.contains(meths[j])) markMethodInSubclasses(c, meths[j], cpg);
375 public void remarkMethods(JavaClass c, JavaClass target, ConstantPoolGen cpg) throws Exception {
376 Method[] meths = getMethods(c);
377 for(int j=0; j<meths.length; j++) if (dest.contains(meths[j])) markMethodInSubclasses(c, meths[j], target, cpg);
380 public static Hashtable methodsHashtable = new Hashtable();
381 public static Method[] getMethods(JavaClass c) {
382 Method[] ret = (Method[])methodsHashtable.get(c);
383 if (ret == null) methodsHashtable.put(c, ret = c.getMethods());