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++)
26 visitJavaMethod(repo.loadClass(classname), meths[i]);
29 public void loadField(String classAndMethodName) throws Exception {
30 String classname = classAndMethodName.substring(0, classAndMethodName.lastIndexOf('.'));
31 String methodname = classAndMethodName.substring(classAndMethodName.lastIndexOf('.') + 1);
32 visitJavaClass(repo.loadClass(classname));
33 Field[] meths = repo.loadClass(classname).getFields();
34 for(int i=0; i<meths.length; i++)
35 if (meths[i].getName().equals(methodname))
36 visitJavaField(meths[i]);
40 public void loadMethod(String classAndMethodName) throws Exception {
41 String classname = classAndMethodName.substring(0, classAndMethodName.lastIndexOf('.'));
42 String methodname = classAndMethodName.substring(classAndMethodName.lastIndexOf('.') + 1);
43 visitJavaClass(repo.loadClass(classname));
44 Method[] meths = getMethods(repo.loadClass(classname));
45 for(int i=0; i<meths.length; i++)
46 if (meths[i].getName().equals(methodname))
47 visitJavaMethod(repo.loadClass(classname), meths[i]);
49 public static void main(String[] s) throws Exception {
51 if (s.length >= 3 && s[1].equals("-o")) { outdir = s[2]; start += 2; }
52 repo = SyntheticRepository.getInstance(new ClassPath(s[0]));
54 BytecodePruner bcp = new BytecodePruner();
55 for(int i=start; i<s.length; i++) {
57 if (s[i].endsWith(".class")) {
58 bcp.visitJavaClass(repo.loadClass(s[i].substring(0, s[i].length() - 6)));
60 JavaClass cl = repo.loadClass(s[i].substring(0, s[i].lastIndexOf('.')));;
61 bcp.visitJavaClass(cl);
62 Method[] meths = getMethods(cl);
63 for(int j=0; j<meths.length; j++) {
64 if (meths[j].getName().equals(s[i].substring(s[i].lastIndexOf('.') + 1)))
65 bcp.visitJavaMethod(cl, meths[j]);
68 } catch (Exception e) {
69 System.out.println("WARNING: couldn't load class for " + s[i]);
73 System.out.println("\n\n======================================================================\n");
75 // we call start(), but the VM calls run()...
76 bcp.loadMethod("java.lang.Thread.run");
77 bcp.loadAllMethods("java.lang.SecurityContext");
78 bcp.visitJavaClass(repo.loadClass("java.awt.AWTPermission"));
79 bcp.visitJavaClass(repo.loadClass("gnu.classpath.Configuration"));
80 bcp.loadAllMethods("java.lang.ThreadDeath");
82 bcp.loadAllMethods("java.util.Hashtable$HashIterator");
83 bcp.loadMethod("java.util.SimpleTimeZone.useDaylightTime");
84 bcp.visitJavaClass(repo.loadClass("gnu.gcj.runtime.FinalizerThread"));
85 bcp.visitJavaClass(repo.loadClass("gnu.gcj.runtime.FirstThread"));
87 bcp.loadMethod("java.lang.Thread.run"); // we call start(), but the VM calls run()...
88 bcp.loadMethod("java.lang.ref.Reference.enqueue"); // the GC calls this directly
89 bcp.loadAllMethods("gnu.gcj.runtime.StringBuffer"); // the compiler emits calls directly to this class
91 bcp.loadAllMethods("gnu.gcj.protocol.http.Handler");
92 bcp.loadAllMethods("gnu.gcj.protocol.file.Handler");
93 bcp.loadAllMethods("gnu.gcj.protocol.core.Handler");
94 bcp.loadAllMethods("gnu.gcj.protocol.jar.Handler");
95 bcp.loadAllMethods("gnu.gcj.convert.Input_UTF8"); // retrieved via reflection
96 bcp.loadAllMethods("gnu.gcj.convert.Output_UTF8"); // retrieved via reflection
97 bcp.loadAllMethods("gnu.gcj.convert.Input_8859_1"); // retrieved via reflection
98 bcp.loadAllMethods("gnu.gcj.convert.Output_8859_1"); // retrieved via reflection
99 bcp.loadAllMethods("gnu.gcj.convert.Input_ASCII"); // retrieved via reflection
100 bcp.loadAllMethods("gnu.gcj.convert.Output_ASCII"); // retrieved via reflection
102 bcp.loadAllMethods("java.util.Date");
103 bcp.loadAllMethods("java.text.DateFormat");
104 bcp.loadAllMethods("java.text.NumberFormat");
106 Method[] meths = getMethods(repo.loadClass("org.ibex.plat.Linux"));
107 for(int i=0; i<meths.length; i++) {
108 if (meths[i].getName().equals("main"))
109 bcp.visitJavaMethod(repo.loadClass("org.ibex.plat.Linux"), meths[i]);
111 System.out.println();
113 System.out.println("Dumping...");
115 StringTokenizer st = new StringTokenizer(s[0], ":");
116 while(st.hasMoreTokens()) {
117 ZipFile zf = new ZipFile(st.nextToken());
118 Enumeration e = zf.entries();
119 while(e.hasMoreElements()) {
120 String ss = ((ZipEntry)e.nextElement()).getName();
121 if (!ss.endsWith(".class")) continue;
122 ss = ss.substring(0, ss.length() - 6);
123 ss = ss.replace('/', '.');
124 dump(repo.loadClass(ss));
129 public BytecodePruner() { }
131 public static void dump(JavaClass clazz) throws Exception {
132 if (!dest.contains(clazz)) return;
134 ConstantPoolGen newcpg = new ConstantPoolGen(clazz.getConstantPool());
135 ClassGen cg = new ClassGen(clazz);
136 InstructionFactory factory = new InstructionFactory(cg, newcpg);
139 cg.setConstantPool(newcpg);
141 // we can only prune static fields (to avoid altering object layout, which is hardcoded into
142 // CNI code), but that's okay since instance fields don't contribute to binary size
143 Field[] fields = clazz.getFields();
144 for(int i=0; i<fields.length; i++)
145 if (!dest.contains(fields[i]) && fields[i].isStatic()) {
146 System.out.println(" pruning field " + clazz.getClassName() + "." + fields[i].getName());
147 cg.removeField(fields[i]);
150 Method[] methods = getMethods(clazz);
152 boolean good = false;
153 for(int i=0; i<methods.length; i++) {
154 if (dest.contains(methods[i]) ||
155 clazz.getClassName().startsWith("java.io.FileDescriptor")
156 || clazz.getClassName().startsWith("gnu.gcj.runtime.")
157 || clazz.getClassName().startsWith("java.lang.")
159 if (!methods[i].getName().equals("<clinit>")) good = true;
161 if (methods[i].getCode() == null) {
162 System.out.println(" empty codeblock: " + clazz.getClassName() + "." + methods[i].getName());
164 System.out.println(" pruning " + clazz.getClassName() + "." + methods[i].getName());
165 if (deleteMethods) { cg.removeMethod(methods[i]); continue; }
166 MethodGen mg = new MethodGen(methods[i], clazz.getClassName(), newcpg);
167 mg.removeExceptions();
168 InstructionList il = new InstructionList();
169 mg.setInstructionList(il);
170 InstructionHandle ih_0 = il.append(factory.createNew("java.lang.UnsatisfiedLinkError"));
171 il.append(InstructionConstants.DUP);
172 il.append(factory.createInvoke("java.lang.UnsatisfiedLinkError",
173 "<init>", Type.VOID, Type.NO_ARGS, Constants.INVOKESPECIAL));
174 il.append(InstructionConstants.ATHROW);
177 mg.removeExceptions();
178 mg.removeLocalVariables();
179 mg.removeExceptionHandlers();
180 mg.removeLineNumbers();
181 cg.replaceMethod(methods[i], mg.getMethod());
187 new File(outdir + "/" + new File(clazz.getClassName().replace('.', '/')).getParent()).mkdirs();
188 System.out.println("dumping " + clazz.getClassName());
189 cg.getJavaClass().dump(outdir + "/" + clazz.getClassName().replace('.', '/') + ".class");
192 public JavaClass sig2class(String sig) throws Exception {
193 if (sig == null) return null;
194 while (sig.length() > 0 && (sig.charAt(0) == 'L' || sig.charAt(0) == '[')) {
195 if (sig.charAt(0) == 'L') sig = sig.substring(1, sig.length() - 1);
196 else if (sig.charAt(0) == '[') sig = sig.substring(1, sig.length());
198 if (sig.length() <= 1) return null;
199 if (sig.equals("<null object>")) return null;
200 if (sig.startsWith("<return address")) return null;
201 return repo.loadClass(sig);
203 public void load(String sig) throws Exception {
204 if (sig == null) return;
205 while (sig.length() > 0 && (sig.charAt(0) == 'L' || sig.charAt(0) == '[')) {
206 if (sig.charAt(0) == 'L') sig = sig.substring(1, sig.length() - 1);
207 else if (sig.charAt(0) == '[') sig = sig.substring(1, sig.length());
209 if (sig.length() <= 1) return;
210 if (sig.equals("<null object>")) return;
211 if (sig.startsWith("<return address")) return;
212 visitJavaClass(repo.loadClass(sig));
214 public void load(Type t) throws Exception {
215 if (t == null) return;
216 //String sig = t.getSignature();
217 if (t instanceof ArrayType) load(((ArrayType)t).getElementType());
218 if (!(t instanceof ObjectType)) return;
219 load(((ObjectType)t).getClassName());
222 // hashtable of hashsets
223 public static Hashtable subclasses = new Hashtable();
225 public String getMethodSignature(Method m, ConstantPoolGen cpg) throws Exception {
226 return m.getName() + m.getSignature();
229 public String getMethodSignature(InvokeInstruction ii, ConstantPoolGen cpg) throws Exception {
231 Type[] argtypes = ii.getArgumentTypes(cpg);
232 for(int j=0; j<argtypes.length; j++) sig += argtypes[j].getSignature();
233 return ii.getMethodName(cpg) + "(" + sig + ")" + ii.getReturnType(cpg).getSignature();
236 public static int level = 0;
237 public void visitJavaMethod(JavaClass jc, Method method) throws Exception {
239 if (jc.getClassName().equals("java.util.Date") && method.getName().equals("readObject")) return;
240 if (jc.getClassName().indexOf("SharedLib") != -1) return;
241 if (jc.getClassName().indexOf("Datagram") != -1) return;
242 if (dest.contains(method)) return;
244 // gcj bug; gcj can't compile this method from a .class file input
245 //if (jc.getClassName().equals("java.lang.System") && method.getName().equals("runFinalizersOnExit")) return;
248 // not inferrable: CNI call to abstract method
249 if (jc.getClassName().equals("java.util.TimeZone") && method.getName().equals("getDefaultTimeZoneId"))
250 loadMethod("java.util.SimpleTimeZone.useDaylightTime");
254 for(int i=0; i<level; i++) System.out.print(" ");
255 ConstantPoolGen cpg = new ConstantPoolGen(method.getConstantPool());
256 System.out.println(jc.getClassName() + "." + getMethodSignature(method, cpg));
257 markMethodInSubclasses(jc, method, cpg);
258 if (method.getCode() == null) { level -= 2; return; }
259 byte[] code = method.getCode().getCode();
260 InstructionList il = new InstructionList(code);
261 Instruction[] instructions = il.getInstructions();
262 for(int i=0; i<instructions.length; i++){
263 Instruction instr = instructions[i];
264 if (instr instanceof LoadClass) load(((LoadClass)instr).getLoadClassType(cpg));
265 if (instr instanceof CPInstruction) load(((CPInstruction)instr).getType(cpg));
266 if (instr instanceof TypedInstruction) {
267 try { load(((TypedInstruction)instr).getType(cpg)); } catch (Exception e) { /* DELIBERATE */ }
269 if (instr instanceof NEW) {
270 for(int j=0; j<level; j++) System.out.print(" ");
271 loadMethod(((NEW)instr).getLoadClassType(cpg).getClassName() + ".<init>");
273 if (instr instanceof org.apache.bcel.generic.FieldOrMethod)
274 load(((org.apache.bcel.generic.FieldOrMethod)instr).getClassType(cpg));
275 if (instr instanceof org.apache.bcel.generic.FieldInstruction) {
276 load(((org.apache.bcel.generic.FieldInstruction)instr).getFieldType(cpg));
277 load(((org.apache.bcel.generic.FieldInstruction)instr).getType(cpg));
278 String fieldName = ((org.apache.bcel.generic.FieldInstruction)instr).getFieldName(cpg);
279 JavaClass jc2 = repo.loadClass(((ObjectType)((org.apache.bcel.generic.FieldInstruction)instr).
280 getLoadClassType(cpg)).getClassName());
281 Field[] fields = jc2.getFields();
282 for(int j=0; j<fields.length; j++) if (fields[j].getName().equals(fieldName)) visitJavaField(fields[j]);
284 if (instr instanceof InvokeInstruction) {
285 InvokeInstruction ii = (InvokeInstruction)instr;
286 String ii_sig = getMethodSignature(ii, cpg);
287 JavaClass c = sig2class(ii.getLoadClassType(cpg).getSignature());
288 load(ii.getReturnType(cpg));
289 load(ii.getType(cpg));
290 Method[] meths = getMethods(c);
291 boolean good = false;
292 for(int i2=0; i2<meths.length; i2++) {
293 if (getMethodSignature(meths[i2], cpg).equals(ii_sig)) {
294 visitJavaMethod(c, meths[i2]);
299 if (!good) throw new Exception("couldn't find method " + getMethodSignature(ii, cpg) + " in " + c.getClassName());
303 load(method.getReturnType());
304 Type[] argtypes = method.getArgumentTypes();
305 for(int i=0; i<argtypes.length; i++) load(argtypes[i]);
306 if (method.getExceptionTable() != null) {
307 String[] exntypes = method.getExceptionTable().getExceptionNames();
308 for(int i=0; i<exntypes.length; i++) load(exntypes[i]);
312 public void visitJavaField(Field field) throws Exception {
313 if (dest.contains(field)) return;
315 load(field.getType());
318 public void visitJavaClass(JavaClass clazz) throws Exception {
319 if (dest.contains(clazz)) return;
322 ConstantPoolGen cpg = new ConstantPoolGen(clazz.getConstantPool());
323 String name = clazz.getClassName();
324 System.out.println(clazz.getClassName() + ".class");
326 JavaClass superclass = clazz.getSuperClass();
327 JavaClass[] interfaces = clazz.getAllInterfaces();
328 for(JavaClass sup = superclass; sup != null; sup = sup.getSuperClass()) {
329 if (subclasses.get(sup) == null) subclasses.put(sup, new HashSet());
330 ((HashSet)subclasses.get(sup)).add(clazz);
332 for(int i=0; i<interfaces.length; i++) {
333 if (subclasses.get(interfaces[i]) == null) subclasses.put(interfaces[i], new HashSet());
334 ((HashSet)subclasses.get(interfaces[i])).add(clazz);
337 if (clazz.getClassName().startsWith("org.ibex."))
338 loadAllMethods(clazz.getClassName());
340 for(JavaClass sup = superclass; sup != null; sup = sup.getSuperClass()) {
342 remarkMethods(sup, clazz, cpg);
344 for(int i=0; i<interfaces.length; i++) {
345 visitJavaClass(interfaces[i]);
346 remarkMethods(interfaces[i], clazz, cpg);
349 Field[] fields = clazz.getFields();
350 for(int i=0; i<fields.length; i++) {
351 if (!fields[i].isStatic())
352 visitJavaField(fields[i]);
355 Method[] methods = getMethods(clazz);
356 for(int i=0; i<methods.length; i++) {
357 if (methods[i].getName().equals("<clinit>")) visitJavaMethod(clazz, methods[i]);
358 // only if ctor reachable (?)
359 if (methods[i].getName().equals("equals")) visitJavaMethod(clazz, methods[i]);
360 if (methods[i].getName().equals("hashCode")) visitJavaMethod(clazz, methods[i]);
361 if (methods[i].getName().equals("finalize")) visitJavaMethod(clazz, methods[i]);
362 if (methods[i].getName().equals("clone")) visitJavaMethod(clazz, methods[i]);
363 if (methods[i].getName().equals("toString")) visitJavaMethod(clazz, methods[i]);
367 public void markMethodInSubclasses(JavaClass c, Method m, JavaClass subclass, ConstantPoolGen cpg) throws Exception {
368 if (m.isStatic()) return;
369 String sig = getMethodSignature(m, cpg);
370 Method[] submethods = getMethods(subclass);
371 for(int j=0; j<submethods.length; j++)
372 if (getMethodSignature(submethods[j], cpg).equals(sig))
373 visitJavaMethod(subclass, submethods[j]);
375 public void markMethodInSubclasses(JavaClass c, Method m, ConstantPoolGen cpg) throws Exception {
376 if (m.isStatic()) return;
377 HashSet s = (HashSet)subclasses.get(c);
378 if (s == null) return;
379 Object[] subclasses = s.toArray();
380 for(int i=0; i<subclasses.length; i++) {
381 JavaClass subclass = (JavaClass)subclasses[i];
382 if (subclass == c) continue;
383 for(int j=0; j<level; j++) System.out.print(" ");
384 System.out.println(" [subclass " + subclass.getClassName() + "]");
385 markMethodInSubclasses(c, m, subclass, cpg);
389 public void remarkMethods(JavaClass c, ConstantPoolGen cpg) throws Exception {
390 Method[] meths =getMethods(c);
391 for(int j=0; j<meths.length; j++) if (dest.contains(meths[j])) markMethodInSubclasses(c, meths[j], cpg);
394 public void remarkMethods(JavaClass c, JavaClass target, ConstantPoolGen cpg) throws Exception {
395 Method[] meths = getMethods(c);
396 for(int j=0; j<meths.length; j++) if (dest.contains(meths[j])) markMethodInSubclasses(c, meths[j], target, cpg);
399 public static Hashtable methodsHashtable = new Hashtable();
400 public static Method[] getMethods(JavaClass c) {
401 Method[] ret = (Method[])methodsHashtable.get(c);
402 if (ret == null) methodsHashtable.put(c, ret = c.getMethods());