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.*;
11 public class BytecodePruner {
13 public static final boolean deleteMethods = false;
16 public static SyntheticRepository repo = null;
18 public static HashSet dest = new HashSet();
20 public static String outdir = ".";
22 public void loadAllMethods(String classname) throws Exception {
23 visitJavaClass(repo.loadClass(classname));
24 Method[] meths = getMethods(repo.loadClass(classname));
25 for(int i=0; i<meths.length; i++) visitJavaMethod(repo.loadClass(classname), meths[i]);
28 public void loadField(String classAndMethodName) throws Exception {
29 String classname = classAndMethodName.substring(0, classAndMethodName.lastIndexOf('.'));
30 String methodname = classAndMethodName.substring(classAndMethodName.lastIndexOf('.') + 1);
31 visitJavaClass(repo.loadClass(classname));
32 Field[] meths = repo.loadClass(classname).getFields();
33 for(int i=0; i<meths.length; i++)
34 if (meths[i].getName().equals(methodname))
35 visitJavaField(meths[i]);
39 public void loadMethod(String classAndMethodName) throws Exception {
40 String classname = classAndMethodName.substring(0, classAndMethodName.lastIndexOf('.'));
41 String methodname = classAndMethodName.substring(classAndMethodName.lastIndexOf('.') + 1);
42 visitJavaClass(repo.loadClass(classname));
43 Method[] meths = getMethods(repo.loadClass(classname));
44 for(int i=0; i<meths.length; i++)
45 if (meths[i].getName().equals(methodname))
46 visitJavaMethod(repo.loadClass(classname), meths[i]);
48 public static void main(String[] s) throws Exception {
50 if (s.length >= 3 && s[1].equals("-o")) { outdir = s[2]; start += 2; }
51 repo = SyntheticRepository.getInstance(new ClassPath(s[0]));
53 BytecodePruner bcp = new BytecodePruner();
54 for(int i=start; i<s.length; i++) {
56 if (s[i].endsWith(".class")) {
57 bcp.visitJavaClass(repo.loadClass(s[i].substring(0, s[i].length() - 6)));
59 JavaClass cl = repo.loadClass(s[i].substring(0, s[i].lastIndexOf('.')));;
60 bcp.visitJavaClass(cl);
61 Method[] meths = getMethods(cl);
62 for(int j=0; j<meths.length; j++) {
63 if (meths[j].getName().equals(s[i].substring(s[i].lastIndexOf('.') + 1)))
64 bcp.visitJavaMethod(cl, meths[j]);
67 } catch (Exception e) {
68 System.out.println("WARNING: couldn't load class for " + s[i]);
72 System.out.println("\n\n======================================================================\n");
74 // we call start(), but the VM calls run()...
75 bcp.loadMethod("java.lang.Thread.run");
76 bcp.loadAllMethods("java.lang.SecurityContext");
77 bcp.visitJavaClass(repo.loadClass("java.awt.AWTPermission"));
78 bcp.visitJavaClass(repo.loadClass("gnu.classpath.Configuration"));
79 bcp.loadAllMethods("java.lang.ThreadDeath");
81 bcp.loadAllMethods("java.util.Hashtable$HashIterator");
82 bcp.loadMethod("java.util.SimpleTimeZone.useDaylightTime");
83 bcp.visitJavaClass(repo.loadClass("gnu.gcj.runtime.FinalizerThread"));
84 bcp.visitJavaClass(repo.loadClass("gnu.gcj.runtime.FirstThread"));
87 bcp.loadAllMethods("gnu.gcj.protocol.http.Handler");
88 bcp.loadAllMethods("gnu.gcj.protocol.file.Handler");
89 bcp.loadAllMethods("gnu.gcj.protocol.core.Handler");
90 bcp.loadAllMethods("gnu.gcj.protocol.jar.Handler");
91 bcp.loadAllMethods("gnu.gcj.convert.Input_UTF8"); // retrieved via reflection
92 bcp.loadAllMethods("gnu.gcj.convert.Output_UTF8"); // retrieved via reflection
93 bcp.loadAllMethods("gnu.gcj.convert.Input_8859_1"); // retrieved via reflection
94 bcp.loadAllMethods("gnu.gcj.convert.Output_8859_1"); // retrieved via reflection
95 bcp.loadAllMethods("gnu.gcj.convert.Input_ASCII"); // retrieved via reflection
96 bcp.loadAllMethods("gnu.gcj.convert.Output_ASCII"); // retrieved via reflection
97 bcp.loadMethod("java.lang.Thread.run"); // we call start(), but the VM calls run()...
98 bcp.loadMethod("java.lang.ref.Reference.enqueue"); // the GC calls this directly
99 bcp.loadAllMethods("gnu.gcj.runtime.StringBuffer"); // the compiler emits calls directly to this class
101 // often called from native subclasses....
103 bcp.loadAllMethods("java.util.Date");
104 bcp.loadAllMethods("java.text.DateFormat");
105 bcp.loadAllMethods("java.text.NumberFormat");
107 Method[] meths = getMethods(repo.loadClass("org.ibex.plat.Linux"));
108 for(int i=0; i<meths.length; i++) {
109 if (meths[i].getName().equals("main"))
110 bcp.visitJavaMethod(repo.loadClass("org.ibex.plat.Linux"), meths[i]);
112 System.out.println();
114 System.out.println("Dumping...");
116 StringTokenizer st = new StringTokenizer(s[0], ":");
117 while(st.hasMoreTokens()) {
118 ZipFile zf = new ZipFile(st.nextToken());
119 Enumeration e = zf.entries();
120 while(e.hasMoreElements()) {
121 String ss = ((ZipEntry)e.nextElement()).getName();
122 if (!ss.endsWith(".class")) continue;
123 ss = ss.substring(0, ss.length() - 6);
124 ss = ss.replace('/', '.');
125 dump(repo.loadClass(ss));
130 public BytecodePruner() { }
132 public static void dump(JavaClass clazz) throws Exception {
133 if (!dest.contains(clazz)) return;
135 ConstantPoolGen newcpg = new ConstantPoolGen(clazz.getConstantPool());
136 ClassGen cg = new ClassGen(clazz);
137 InstructionFactory factory = new InstructionFactory(cg, newcpg);
140 cg.setConstantPool(newcpg);
141 Field[] fields = clazz.getFields();
142 for(int i=0; i<fields.length; i++)
143 if (!dest.contains(fields[i]) && false) {
144 System.out.println(" pruning " + clazz.getClassName() + "." + fields[i].getName());
145 cg.removeField(fields[i]);
148 Method[] methods = getMethods(clazz);
150 boolean good = false;
151 for(int i=0; i<methods.length; i++) {
152 if (dest.contains(methods[i]) ||
153 clazz.getClassName().startsWith("java.io.FileDescriptor")
154 || clazz.getClassName().startsWith("gnu.gcj.runtime.")
155 || clazz.getClassName().startsWith("java.lang.")
157 if (!methods[i].getName().equals("<clinit>")) good = true;
159 if (methods[i].getCode() == null) {
160 System.out.println(" empty codeblock: " + clazz.getClassName() + "." + methods[i].getName());
162 System.out.println(" pruning " + clazz.getClassName() + "." + methods[i].getName());
163 if (deleteMethods) { cg.removeMethod(methods[i]); continue; }
164 MethodGen mg = new MethodGen(methods[i], clazz.getClassName(), newcpg);
165 mg.removeExceptions();
166 InstructionList il = new InstructionList();
167 mg.setInstructionList(il);
168 InstructionHandle ih_0 = il.append(factory.createNew("java.lang.UnsatisfiedLinkError"));
169 il.append(InstructionConstants.DUP);
170 il.append(factory.createInvoke("java.lang.UnsatisfiedLinkError",
171 "<init>", Type.VOID, Type.NO_ARGS, Constants.INVOKESPECIAL));
172 il.append(InstructionConstants.ATHROW);
175 mg.removeExceptions();
176 mg.removeLocalVariables();
177 mg.removeExceptionHandlers();
178 mg.removeLineNumbers();
179 cg.replaceMethod(methods[i], mg.getMethod());
185 new File(outdir + "/" + new File(clazz.getClassName().replace('.', '/')).getParent()).mkdirs();
186 System.out.println("dumping " + clazz.getClassName());
187 cg.getJavaClass().dump(outdir + "/" + clazz.getClassName().replace('.', '/') + ".class");
190 public JavaClass sig2class(String sig) throws Exception {
191 if (sig == null) return null;
192 while (sig.length() > 0 && (sig.charAt(0) == 'L' || sig.charAt(0) == '[')) {
193 if (sig.charAt(0) == 'L') sig = sig.substring(1, sig.length() - 1);
194 else if (sig.charAt(0) == '[') sig = sig.substring(1, sig.length());
196 if (sig.length() <= 1) return null;
197 if (sig.equals("<null object>")) return null;
198 if (sig.startsWith("<return address")) return null;
199 return repo.loadClass(sig);
201 public void load(String sig) throws Exception {
202 if (sig == null) return;
203 while (sig.length() > 0 && (sig.charAt(0) == 'L' || sig.charAt(0) == '[')) {
204 if (sig.charAt(0) == 'L') sig = sig.substring(1, sig.length() - 1);
205 else if (sig.charAt(0) == '[') sig = sig.substring(1, sig.length());
207 if (sig.length() <= 1) return;
208 if (sig.equals("<null object>")) return;
209 if (sig.startsWith("<return address")) return;
210 visitJavaClass(repo.loadClass(sig));
212 public void load(Type t) throws Exception {
213 if (t == null) return;
214 //String sig = t.getSignature();
215 if (t instanceof ArrayType) load(((ArrayType)t).getElementType());
216 if (!(t instanceof ObjectType)) return;
217 load(((ObjectType)t).getClassName());
220 // hashtable of hashsets
221 public static Hashtable subclasses = new Hashtable();
223 public String getMethodSignature(Method m, ConstantPoolGen cpg) throws Exception {
224 return m.getName() + m.getSignature();
227 public String getMethodSignature(InvokeInstruction ii, ConstantPoolGen cpg) throws Exception {
229 Type[] argtypes = ii.getArgumentTypes(cpg);
230 for(int j=0; j<argtypes.length; j++) sig += argtypes[j].getSignature();
231 return ii.getMethodName(cpg) + "(" + sig + ")" + ii.getReturnType(cpg).getSignature();
234 public static int level = 0;
235 public void visitJavaMethod(JavaClass jc, Method method) throws Exception {
237 if (jc.getClassName().equals("java.util.Date") && method.getName().equals("readObject")) return;
238 if (jc.getClassName().indexOf("SharedLib") != -1) return;
239 if (jc.getClassName().indexOf("Datagram") != -1) return;
240 if (dest.contains(method)) return;
242 // gcj bug; gcj can't compile this method from a .class file input
243 //if (jc.getClassName().equals("java.lang.System") && method.getName().equals("runFinalizersOnExit")) return;
247 for(int i=0; i<level; i++) System.out.print(" ");
248 ConstantPoolGen cpg = new ConstantPoolGen(method.getConstantPool());
249 System.out.println(jc.getClassName() + "." + getMethodSignature(method, cpg));
250 markMethodInSubclasses(jc, method, cpg);
251 if (method.getCode() == null) { level -= 2; return; }
252 byte[] code = method.getCode().getCode();
253 InstructionList il = new InstructionList(code);
254 Instruction[] instructions = il.getInstructions();
255 for(int i=0; i<instructions.length; i++){
256 Instruction instr = instructions[i];
257 if (instr instanceof LoadClass) load(((LoadClass)instr).getLoadClassType(cpg));
258 if (instr instanceof CPInstruction) load(((CPInstruction)instr).getType(cpg));
259 if (instr instanceof InvokeInstruction) {
260 InvokeInstruction ii = (InvokeInstruction)instr;
261 String ii_sig = getMethodSignature(ii, cpg);
262 JavaClass c = sig2class(ii.getLoadClassType(cpg).getSignature());
263 load(ii.getReturnType(cpg));
264 load(ii.getType(cpg));
265 Method[] meths = getMethods(c);
266 boolean good = false;
267 for(int i2=0; i2<meths.length; i2++) {
268 if (getMethodSignature(meths[i2], cpg).equals(ii_sig)) {
269 visitJavaMethod(c, meths[i2]);
274 if (!good) throw new Exception("couldn't find method " + getMethodSignature(ii, cpg) + " in " + c.getClassName());
278 load(method.getReturnType());
279 Type[] argtypes = method.getArgumentTypes();
280 for(int i=0; i<argtypes.length; i++) load(argtypes[i]);
281 if (method.getExceptionTable() != null) {
282 String[] exntypes = method.getExceptionTable().getExceptionNames();
283 for(int i=0; i<exntypes.length; i++) load(exntypes[i]);
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 {
294 if (dest.contains(clazz)) return;
297 ConstantPoolGen cpg = new ConstantPoolGen(clazz.getConstantPool());
298 String name = clazz.getClassName();
299 System.out.println(clazz.getClassName() + ".class");
301 JavaClass superclass = clazz.getSuperClass();
302 JavaClass[] interfaces = clazz.getAllInterfaces();
303 for(JavaClass sup = superclass; sup != null; sup = sup.getSuperClass()) {
304 if (subclasses.get(sup) == null) subclasses.put(sup, new HashSet());
305 ((HashSet)subclasses.get(sup)).add(clazz);
307 for(int i=0; i<interfaces.length; i++) {
308 if (subclasses.get(interfaces[i]) == null) subclasses.put(interfaces[i], new HashSet());
309 ((HashSet)subclasses.get(interfaces[i])).add(clazz);
312 if (clazz.getClassName().startsWith("org.ibex."))
313 loadAllMethods(clazz.getClassName());
315 for(JavaClass sup = superclass; sup != null; sup = sup.getSuperClass()) {
317 remarkMethods(sup, clazz, cpg);
319 for(int i=0; i<interfaces.length; i++) {
320 visitJavaClass(interfaces[i]);
321 remarkMethods(interfaces[i], clazz, cpg);
324 Field[] fields = clazz.getFields();
325 Method[] methods = getMethods(clazz);
326 for(int i=0; i<fields.length; i++) visitJavaField(fields[i]);
327 for(int i=0; i<methods.length; i++) {
328 if (methods[i].getName().equals("<clinit>")) visitJavaMethod(clazz, methods[i]);
330 // only if ctor reachable (?)
331 if (methods[i].getName().equals("equals")) visitJavaMethod(clazz, methods[i]);
332 if (methods[i].getName().equals("hashCode")) visitJavaMethod(clazz, methods[i]);
333 if (methods[i].getName().equals("finalize")) visitJavaMethod(clazz, methods[i]);
334 if (methods[i].getName().equals("clone")) visitJavaMethod(clazz, methods[i]);
335 if (methods[i].getName().equals("toString")) visitJavaMethod(clazz, methods[i]);
339 public void markMethodInSubclasses(JavaClass c, Method m, JavaClass subclass, ConstantPoolGen cpg) throws Exception {
340 if (m.isStatic()) return;
341 String sig = getMethodSignature(m, cpg);
342 Method[] submethods = getMethods(subclass);
343 for(int j=0; j<submethods.length; j++)
344 if (getMethodSignature(submethods[j], cpg).equals(sig))
345 visitJavaMethod(subclass, submethods[j]);
347 public void markMethodInSubclasses(JavaClass c, Method m, ConstantPoolGen cpg) throws Exception {
348 if (m.isStatic()) return;
349 HashSet s = (HashSet)subclasses.get(c);
350 if (s == null) return;
351 Object[] subclasses = s.toArray();
352 for(int i=0; i<subclasses.length; i++) {
353 JavaClass subclass = (JavaClass)subclasses[i];
354 if (subclass == c) continue;
355 for(int j=0; j<level; j++) System.out.print(" ");
356 System.out.println(" [subclass " + subclass.getClassName() + "]");
357 markMethodInSubclasses(c, m, subclass, cpg);
361 public void remarkMethods(JavaClass c, ConstantPoolGen cpg) throws Exception {
362 Method[] meths =getMethods(c);
363 for(int j=0; j<meths.length; j++) if (dest.contains(meths[j])) markMethodInSubclasses(c, meths[j], cpg);
366 public void remarkMethods(JavaClass c, JavaClass target, ConstantPoolGen cpg) throws Exception {
367 Method[] meths = getMethods(c);
368 for(int j=0; j<meths.length; j++) if (dest.contains(meths[j])) markMethodInSubclasses(c, meths[j], target, cpg);
371 public static Hashtable methodsHashtable = new Hashtable();
372 public static Method[] getMethods(JavaClass c) {
373 Method[] ret = (Method[])methodsHashtable.get(c);
374 if (ret == null) methodsHashtable.put(c, ret = c.getMethods());