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();
112 System.out.println("Dumping...");
114 StringTokenizer st = new StringTokenizer(s[0], ":");
115 while(st.hasMoreTokens()) {
116 ZipFile zf = new ZipFile(st.nextToken());
117 Enumeration e = zf.entries();
118 while(e.hasMoreElements()) {
119 String ss = ((ZipEntry)e.nextElement()).getName();
120 if (!ss.endsWith(".class")) continue;
121 ss = ss.substring(0, ss.length() - 6);
122 ss = ss.replace('/', '.');
123 dump(repo.loadClass(ss));
128 public BytecodePruner() { }
130 public static void dump(JavaClass clazz) throws Exception {
131 if (!dest.contains(clazz)) return;
133 ConstantPoolGen newcpg = new ConstantPoolGen(clazz.getConstantPool());
134 ClassGen cg = new ClassGen(clazz);
135 InstructionFactory factory = new InstructionFactory(cg, newcpg);
138 cg.setConstantPool(newcpg);
140 // we can only prune static fields (to avoid altering object layout, which is hardcoded into
141 // CNI code), but that's okay since instance fields don't contribute to binary size
142 Field[] fields = clazz.getFields();
143 for(int i=0; i<fields.length; i++)
144 if (!dest.contains(fields[i]) && fields[i].isStatic()) {
145 System.out.println(" pruning field " + clazz.getClassName() + "." + fields[i].getName());
146 cg.removeField(fields[i]);
149 Method[] methods = getMethods(clazz);
151 boolean good = false;
152 for(int i=0; i<methods.length; i++) {
153 if (dest.contains(methods[i]) ||
154 clazz.getClassName().startsWith("java.io.FileDescriptor")
155 || clazz.getClassName().startsWith("gnu.gcj.runtime.")
156 || clazz.getClassName().startsWith("java.lang.")
158 if (!methods[i].getName().equals("<clinit>")) good = true;
160 if (methods[i].getCode() == null) {
161 System.out.println(" empty codeblock: " + clazz.getClassName() + "." + methods[i].getName());
163 System.out.println(" pruning " + clazz.getClassName() + "." + methods[i].getName());
164 if (deleteMethods) { cg.removeMethod(methods[i]); continue; }
165 MethodGen mg = new MethodGen(methods[i], clazz.getClassName(), newcpg);
166 mg.removeExceptions();
167 InstructionList il = new InstructionList();
168 mg.setInstructionList(il);
169 InstructionHandle ih_0 = il.append(factory.createNew("java.lang.UnsatisfiedLinkError"));
170 il.append(InstructionConstants.DUP);
171 il.append(factory.createInvoke("java.lang.UnsatisfiedLinkError",
172 "<init>", Type.VOID, Type.NO_ARGS, Constants.INVOKESPECIAL));
173 il.append(InstructionConstants.ATHROW);
176 mg.removeExceptions();
177 mg.removeLocalVariables();
178 mg.removeExceptionHandlers();
179 mg.removeLineNumbers();
180 cg.replaceMethod(methods[i], mg.getMethod());
186 new File(outdir + "/" + new File(clazz.getClassName().replace('.', '/')).getParent()).mkdirs();
187 System.out.println("dumping " + clazz.getClassName());
188 cg.getJavaClass().dump(outdir + "/" + clazz.getClassName().replace('.', '/') + ".class");
191 public JavaClass sig2class(String sig) throws Exception {
192 if (sig == null) return null;
193 while (sig.length() > 0 && (sig.charAt(0) == 'L' || sig.charAt(0) == '[')) {
194 if (sig.charAt(0) == 'L') sig = sig.substring(1, sig.length() - 1);
195 else if (sig.charAt(0) == '[') sig = sig.substring(1, sig.length());
197 if (sig.length() <= 1) return null;
198 if (sig.equals("<null object>")) return null;
199 if (sig.startsWith("<return address")) return null;
200 return repo.loadClass(sig);
202 public void load(String sig) throws Exception {
203 if (sig == null) return;
204 while (sig.length() > 0 && (sig.charAt(0) == 'L' || sig.charAt(0) == '[')) {
205 if (sig.charAt(0) == 'L') sig = sig.substring(1, sig.length() - 1);
206 else if (sig.charAt(0) == '[') sig = sig.substring(1, sig.length());
208 if (sig.length() <= 1) return;
209 if (sig.equals("<null object>")) return;
210 if (sig.startsWith("<return address")) return;
211 visitJavaClass(repo.loadClass(sig));
213 public void load(Type t) throws Exception {
214 if (t == null) return;
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 {
238 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;
246 // not inferrable: CNI call to abstract method
247 if (jc.getClassName().equals("java.util.TimeZone") && method.getName().equals("getDefaultTimeZoneId"))
248 loadMethod("java.util.SimpleTimeZone.useDaylightTime");
253 for(int i=0; i<level; i++) System.out.print(" ");
254 ConstantPoolGen cpg = new ConstantPoolGen(method.getConstantPool());
255 System.out.println(jc.getClassName() + "." + getMethodSignature(method, cpg));
256 markMethodInSubclasses(jc, method, cpg);
257 if (method.getCode() == null) { level -= 2; return; }
258 byte[] code = method.getCode().getCode();
259 InstructionList il = new InstructionList(code);
260 Instruction[] instructions = il.getInstructions();
261 for(int i=0; i<instructions.length; i++){
262 Instruction instr = instructions[i];
263 if (instr instanceof LoadClass) load(((LoadClass)instr).getLoadClassType(cpg));
264 if (instr instanceof CPInstruction) load(((CPInstruction)instr).getType(cpg));
265 if (instr instanceof TypedInstruction) {
266 try { load(((TypedInstruction)instr).getType(cpg)); } catch (Exception e) { /* DELIBERATE */ }
268 if (instr instanceof NEW) {
269 for(int j=0; j<level; j++) System.out.print(" ");
270 loadMethod(((NEW)instr).getLoadClassType(cpg).getClassName() + ".<init>");
272 if (instr instanceof org.apache.bcel.generic.FieldOrMethod)
273 load(((org.apache.bcel.generic.FieldOrMethod)instr).getClassType(cpg));
274 if (instr instanceof org.apache.bcel.generic.FieldInstruction) {
275 load(((org.apache.bcel.generic.FieldInstruction)instr).getFieldType(cpg));
276 load(((org.apache.bcel.generic.FieldInstruction)instr).getType(cpg));
277 String fieldName = ((org.apache.bcel.generic.FieldInstruction)instr).getFieldName(cpg);
278 JavaClass jc2 = repo.loadClass(((ObjectType)((org.apache.bcel.generic.FieldInstruction)instr).
279 getLoadClassType(cpg)).getClassName());
280 Field[] fields = jc2.getFields();
281 for(int j=0; j<fields.length; j++) if (fields[j].getName().equals(fieldName)) visitJavaField(fields[j]);
283 if (instr instanceof InvokeInstruction) {
284 InvokeInstruction ii = (InvokeInstruction)instr;
285 String ii_sig = getMethodSignature(ii, cpg);
286 JavaClass c = sig2class(ii.getLoadClassType(cpg).getSignature());
287 load(ii.getReturnType(cpg));
288 load(ii.getType(cpg));
289 Method[] meths = getMethods(c);
290 boolean good = false;
291 for(int i2=0; i2<meths.length; i2++) {
292 if (getMethodSignature(meths[i2], cpg).equals(ii_sig)) {
293 visitJavaMethod(c, meths[i2]);
298 if (!good) throw new Exception("couldn't find method " + getMethodSignature(ii, cpg) + " in " + c.getClassName());
302 load(method.getReturnType());
303 Type[] argtypes = method.getArgumentTypes();
304 for(int i=0; i<argtypes.length; i++) load(argtypes[i]);
305 if (method.getExceptionTable() != null) {
306 String[] exntypes = method.getExceptionTable().getExceptionNames();
307 for(int i=0; i<exntypes.length; i++) load(exntypes[i]);
311 public void visitJavaField(Field field) throws Exception {
312 if (dest.contains(field)) return;
314 load(field.getType());
317 public void visitJavaClass(JavaClass clazz) throws Exception {
318 if (dest.contains(clazz)) return;
321 ConstantPoolGen cpg = new ConstantPoolGen(clazz.getConstantPool());
322 String name = clazz.getClassName();
323 System.out.println(clazz.getClassName() + ".class");
325 JavaClass superclass = clazz.getSuperClass();
326 JavaClass[] interfaces = clazz.getAllInterfaces();
327 for(JavaClass sup = superclass; sup != null; sup = sup.getSuperClass()) {
328 if (subclasses.get(sup) == null) subclasses.put(sup, new HashSet());
329 ((HashSet)subclasses.get(sup)).add(clazz);
331 for(int i=0; i<interfaces.length; i++) {
332 if (subclasses.get(interfaces[i]) == null) subclasses.put(interfaces[i], new HashSet());
333 ((HashSet)subclasses.get(interfaces[i])).add(clazz);
336 if (clazz.getClassName().startsWith("org.ibex."))
337 loadAllMethods(clazz.getClassName());
339 for(JavaClass sup = superclass; sup != null; sup = sup.getSuperClass()) {
341 remarkMethods(sup, clazz, cpg);
343 for(int i=0; i<interfaces.length; i++) {
344 visitJavaClass(interfaces[i]);
345 remarkMethods(interfaces[i], clazz, cpg);
348 Field[] fields = clazz.getFields();
349 for(int i=0; i<fields.length; i++) {
350 if (!fields[i].isStatic())
351 visitJavaField(fields[i]);
354 Method[] methods = getMethods(clazz);
355 for(int i=0; i<methods.length; i++) {
356 if (methods[i].getName().equals("<clinit>")) visitJavaMethod(clazz, methods[i]);
357 // only if ctor reachable (?)
358 if (methods[i].getName().equals("equals")) visitJavaMethod(clazz, methods[i]);
359 if (methods[i].getName().equals("hashCode")) visitJavaMethod(clazz, methods[i]);
360 if (methods[i].getName().equals("finalize")) visitJavaMethod(clazz, methods[i]);
361 if (methods[i].getName().equals("clone")) visitJavaMethod(clazz, methods[i]);
362 if (methods[i].getName().equals("toString")) visitJavaMethod(clazz, methods[i]);
366 public void markMethodInSubclasses(JavaClass c, Method m, JavaClass subclass, ConstantPoolGen cpg) throws Exception {
367 if (m.isStatic()) return;
368 String sig = getMethodSignature(m, cpg);
369 Method[] submethods = getMethods(subclass);
370 for(int j=0; j<submethods.length; j++)
371 if (getMethodSignature(submethods[j], cpg).equals(sig))
372 visitJavaMethod(subclass, submethods[j]);
374 public void markMethodInSubclasses(JavaClass c, Method m, ConstantPoolGen cpg) throws Exception {
375 if (m.isStatic()) return;
376 HashSet s = (HashSet)subclasses.get(c);
377 if (s == null) return;
378 Object[] subclasses = s.toArray();
379 for(int i=0; i<subclasses.length; i++) {
380 JavaClass subclass = (JavaClass)subclasses[i];
381 if (subclass == c) continue;
382 for(int j=0; j<level; j++) System.out.print(" ");
383 System.out.println(" [subclass " + subclass.getClassName() + "]");
384 markMethodInSubclasses(c, m, subclass, cpg);
388 public void remarkMethods(JavaClass c, ConstantPoolGen cpg) throws Exception {
389 Method[] meths =getMethods(c);
390 for(int j=0; j<meths.length; j++) if (dest.contains(meths[j])) markMethodInSubclasses(c, meths[j], cpg);
393 public void remarkMethods(JavaClass c, JavaClass target, ConstantPoolGen cpg) throws Exception {
394 Method[] meths = getMethods(c);
395 for(int j=0; j<meths.length; j++) if (dest.contains(meths[j])) markMethodInSubclasses(c, meths[j], target, cpg);
398 public static Hashtable methodsHashtable = new Hashtable();
399 public static Method[] getMethods(JavaClass c) {
400 Method[] ret = (Method[])methodsHashtable.get(c);
401 if (ret == null) methodsHashtable.put(c, ret = c.getMethods());