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"));
86 bcp.loadMethod("java.lang.Thread.run"); // we call start(), but the VM calls run()...
87 bcp.loadMethod("java.lang.ref.Reference.enqueue"); // the GC calls this directly
88 bcp.loadAllMethods("gnu.gcj.runtime.StringBuffer"); // the compiler emits calls directly to this class
90 bcp.loadAllMethods("java.util.Date");
91 bcp.loadAllMethods("java.text.DateFormat");
92 bcp.loadAllMethods("java.text.NumberFormat");
94 Method[] meths = getMethods(repo.loadClass("org.ibex.plat.Linux"));
95 for(int i=0; i<meths.length; i++) {
96 if (meths[i].getName().equals("main"))
97 bcp.visitJavaMethod(repo.loadClass("org.ibex.plat.Linux"), meths[i]);
101 System.out.println("Dumping...");
103 StringTokenizer st = new StringTokenizer(s[0], ":");
104 while(st.hasMoreTokens()) {
105 ZipFile zf = new ZipFile(st.nextToken());
106 Enumeration e = zf.entries();
107 while(e.hasMoreElements()) {
108 String ss = ((ZipEntry)e.nextElement()).getName();
109 if (!ss.endsWith(".class")) continue;
110 ss = ss.substring(0, ss.length() - 6);
111 ss = ss.replace('/', '.');
112 dump(repo.loadClass(ss));
117 public BytecodePruner() { }
119 public static void dump(JavaClass clazz) throws Exception {
120 if (!dest.contains(clazz)) return;
122 ConstantPoolGen newcpg = new ConstantPoolGen(clazz.getConstantPool());
123 ClassGen cg = new ClassGen(clazz);
124 InstructionFactory factory = new InstructionFactory(cg, newcpg);
127 cg.setConstantPool(newcpg);
128 Field[] fields = clazz.getFields();
129 for(int i=0; i<fields.length; i++)
130 if (!dest.contains(fields[i]) && false) {
131 System.out.println(" pruning " + clazz.getClassName() + "." + fields[i].getName());
132 cg.removeField(fields[i]);
135 Method[] methods = getMethods(clazz);
137 boolean good = false;
138 for(int i=0; i<methods.length; i++) {
139 if (dest.contains(methods[i]) ||
140 clazz.getClassName().startsWith("java.io.FileDescriptor")
141 || clazz.getClassName().startsWith("gnu.gcj.runtime.")
142 || clazz.getClassName().startsWith("java.lang.")
144 if (!methods[i].getName().equals("<clinit>")) good = true;
146 if (methods[i].getCode() == null) {
147 System.out.println(" empty codeblock: " + clazz.getClassName() + "." + methods[i].getName());
149 System.out.println(" pruning " + clazz.getClassName() + "." + methods[i].getName());
150 if (deleteMethods) { cg.removeMethod(methods[i]); continue; }
151 MethodGen mg = new MethodGen(methods[i], clazz.getClassName(), newcpg);
152 mg.removeExceptions();
153 InstructionList il = new InstructionList();
154 mg.setInstructionList(il);
155 InstructionHandle ih_0 = il.append(factory.createNew("java.lang.UnsatisfiedLinkError"));
156 il.append(InstructionConstants.DUP);
157 il.append(factory.createInvoke("java.lang.UnsatisfiedLinkError",
158 "<init>", Type.VOID, Type.NO_ARGS, Constants.INVOKESPECIAL));
159 il.append(InstructionConstants.ATHROW);
162 mg.removeExceptions();
163 mg.removeLocalVariables();
164 mg.removeExceptionHandlers();
165 mg.removeLineNumbers();
166 cg.replaceMethod(methods[i], mg.getMethod());
172 new File(outdir + "/" + new File(clazz.getClassName().replace('.', '/')).getParent()).mkdirs();
173 System.out.println("dumping " + clazz.getClassName());
174 cg.getJavaClass().dump(outdir + "/" + clazz.getClassName().replace('.', '/') + ".class");
177 public JavaClass sig2class(String sig) throws Exception {
178 if (sig == null) return null;
179 while (sig.length() > 0 && (sig.charAt(0) == 'L' || sig.charAt(0) == '[')) {
180 if (sig.charAt(0) == 'L') sig = sig.substring(1, sig.length() - 1);
181 else if (sig.charAt(0) == '[') sig = sig.substring(1, sig.length());
183 if (sig.length() <= 1) return null;
184 if (sig.equals("<null object>")) return null;
185 if (sig.startsWith("<return address")) return null;
186 return repo.loadClass(sig);
188 public void load(String sig) throws Exception {
189 if (sig == null) return;
190 while (sig.length() > 0 && (sig.charAt(0) == 'L' || sig.charAt(0) == '[')) {
191 if (sig.charAt(0) == 'L') sig = sig.substring(1, sig.length() - 1);
192 else if (sig.charAt(0) == '[') sig = sig.substring(1, sig.length());
194 if (sig.length() <= 1) return;
195 if (sig.equals("<null object>")) return;
196 if (sig.startsWith("<return address")) return;
197 visitJavaClass(repo.loadClass(sig));
199 public void load(Type t) throws Exception {
200 if (t == null) return;
201 //String sig = t.getSignature();
202 if (t instanceof ArrayType) load(((ArrayType)t).getElementType());
203 if (!(t instanceof ObjectType)) return;
204 load(((ObjectType)t).getClassName());
207 // hashtable of hashsets
208 public static Hashtable subclasses = new Hashtable();
210 public String getMethodSignature(Method m, ConstantPoolGen cpg) throws Exception {
211 return m.getName() + m.getSignature();
214 public String getMethodSignature(InvokeInstruction ii, ConstantPoolGen cpg) throws Exception {
216 Type[] argtypes = ii.getArgumentTypes(cpg);
217 for(int j=0; j<argtypes.length; j++) sig += argtypes[j].getSignature();
218 return ii.getMethodName(cpg) + "(" + sig + ")" + ii.getReturnType(cpg).getSignature();
221 public static int level = 0;
222 public void visitJavaMethod(JavaClass jc, Method method) throws Exception {
224 if (jc.getClassName().equals("java.util.Date") && method.getName().equals("readObject")) return;
225 if (jc.getClassName().indexOf("SharedLib") != -1) return;
226 if (jc.getClassName().indexOf("Datagram") != -1) return;
227 if (dest.contains(method)) return;
229 // gcj bug; gcj can't compile this method from a .class file input
230 //if (jc.getClassName().equals("java.lang.System") && method.getName().equals("runFinalizersOnExit")) return;
234 for(int i=0; i<level; i++) System.out.print(" ");
235 ConstantPoolGen cpg = new ConstantPoolGen(method.getConstantPool());
236 System.out.println(jc.getClassName() + "." + getMethodSignature(method, cpg));
237 markMethodInSubclasses(jc, method, cpg);
238 if (method.getCode() == null) { level -= 2; return; }
239 byte[] code = method.getCode().getCode();
240 InstructionList il = new InstructionList(code);
241 Instruction[] instructions = il.getInstructions();
242 for(int i=0; i<instructions.length; i++){
243 Instruction instr = instructions[i];
244 if (instr instanceof LoadClass) load(((LoadClass)instr).getLoadClassType(cpg));
245 if (instr instanceof CPInstruction) load(((CPInstruction)instr).getType(cpg));
246 if (instr instanceof InvokeInstruction) {
247 InvokeInstruction ii = (InvokeInstruction)instr;
248 String ii_sig = getMethodSignature(ii, cpg);
249 JavaClass c = sig2class(ii.getLoadClassType(cpg).getSignature());
250 load(ii.getReturnType(cpg));
251 load(ii.getType(cpg));
252 Method[] meths = getMethods(c);
253 boolean good = false;
254 for(int i2=0; i2<meths.length; i2++) {
255 if (getMethodSignature(meths[i2], cpg).equals(ii_sig)) {
256 visitJavaMethod(c, meths[i2]);
261 if (!good) throw new Exception("couldn't find method " + getMethodSignature(ii, cpg) + " in " + c.getClassName());
265 load(method.getReturnType());
266 Type[] argtypes = method.getArgumentTypes();
267 for(int i=0; i<argtypes.length; i++) load(argtypes[i]);
268 if (method.getExceptionTable() != null) {
269 String[] exntypes = method.getExceptionTable().getExceptionNames();
270 for(int i=0; i<exntypes.length; i++) load(exntypes[i]);
274 public void visitJavaField(Field field) throws Exception {
275 if (dest.contains(field)) return;
277 load(field.getType());
280 public void visitJavaClass(JavaClass clazz) throws Exception {
281 if (dest.contains(clazz)) return;
284 ConstantPoolGen cpg = new ConstantPoolGen(clazz.getConstantPool());
285 String name = clazz.getClassName();
286 System.out.println(clazz.getClassName() + ".class");
288 JavaClass superclass = clazz.getSuperClass();
289 JavaClass[] interfaces = clazz.getAllInterfaces();
290 for(JavaClass sup = superclass; sup != null; sup = sup.getSuperClass()) {
291 if (subclasses.get(sup) == null) subclasses.put(sup, new HashSet());
292 ((HashSet)subclasses.get(sup)).add(clazz);
294 for(int i=0; i<interfaces.length; i++) {
295 if (subclasses.get(interfaces[i]) == null) subclasses.put(interfaces[i], new HashSet());
296 ((HashSet)subclasses.get(interfaces[i])).add(clazz);
299 if (clazz.getClassName().startsWith("org.ibex."))
300 loadAllMethods(clazz.getClassName());
302 for(JavaClass sup = superclass; sup != null; sup = sup.getSuperClass()) {
304 remarkMethods(sup, clazz, cpg);
306 for(int i=0; i<interfaces.length; i++) {
307 visitJavaClass(interfaces[i]);
308 remarkMethods(interfaces[i], clazz, cpg);
311 Field[] fields = clazz.getFields();
312 Method[] methods = getMethods(clazz);
313 for(int i=0; i<fields.length; i++) visitJavaField(fields[i]);
314 for(int i=0; i<methods.length; i++) {
315 if (methods[i].getName().equals("<clinit>")) visitJavaMethod(clazz, methods[i]);
317 // only if ctor reachable (?)
318 if (methods[i].getName().equals("equals")) visitJavaMethod(clazz, methods[i]);
319 if (methods[i].getName().equals("hashCode")) visitJavaMethod(clazz, methods[i]);
320 if (methods[i].getName().equals("finalize")) visitJavaMethod(clazz, methods[i]);
321 if (methods[i].getName().equals("clone")) visitJavaMethod(clazz, methods[i]);
322 if (methods[i].getName().equals("toString")) visitJavaMethod(clazz, methods[i]);
326 public void markMethodInSubclasses(JavaClass c, Method m, JavaClass subclass, ConstantPoolGen cpg) throws Exception {
327 if (m.isStatic()) return;
328 String sig = getMethodSignature(m, cpg);
329 Method[] submethods = getMethods(subclass);
330 for(int j=0; j<submethods.length; j++)
331 if (getMethodSignature(submethods[j], cpg).equals(sig))
332 visitJavaMethod(subclass, submethods[j]);
334 public void markMethodInSubclasses(JavaClass c, Method m, ConstantPoolGen cpg) throws Exception {
335 if (m.isStatic()) return;
336 HashSet s = (HashSet)subclasses.get(c);
337 if (s == null) return;
338 Object[] subclasses = s.toArray();
339 for(int i=0; i<subclasses.length; i++) {
340 JavaClass subclass = (JavaClass)subclasses[i];
341 if (subclass == c) continue;
342 for(int j=0; j<level; j++) System.out.print(" ");
343 System.out.println(" [subclass " + subclass.getClassName() + "]");
344 markMethodInSubclasses(c, m, subclass, cpg);
348 public void remarkMethods(JavaClass c, ConstantPoolGen cpg) throws Exception {
349 Method[] meths =getMethods(c);
350 for(int j=0; j<meths.length; j++) if (dest.contains(meths[j])) markMethodInSubclasses(c, meths[j], cpg);
353 public void remarkMethods(JavaClass c, JavaClass target, ConstantPoolGen cpg) throws Exception {
354 Method[] meths = getMethods(c);
355 for(int j=0; j<meths.length; j++) if (dest.contains(meths[j])) markMethodInSubclasses(c, meths[j], target, cpg);
358 public static Hashtable methodsHashtable = new Hashtable();
359 public static Method[] getMethods(JavaClass c) {
360 Method[] ret = (Method[])methodsHashtable.get(c);
361 if (ret == null) methodsHashtable.put(c, ret = c.getMethods());