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 // can we drop nio? in natibex.a?
12 public class BytecodePruner {
14 public static final boolean deleteMethods = false;
15 public static SyntheticRepository repo = null;
16 public static HashSet dest = new HashSet();
17 public static String outdir = ".";
18 public static Hashtable subclasses = new Hashtable();
19 public static int level = 0;
21 public BytecodePruner() { }
23 public void loadAllMethods(String classname) throws Exception {
24 visitJavaClass(repo.loadClass(classname));
25 Method[] meths = getMethods(repo.loadClass(classname));
26 for(int i=0; i<meths.length; i++)
27 visitJavaMethod(repo.loadClass(classname), meths[i]);
30 public void loadField(String classAndMethodName) throws Exception {
31 String classname = classAndMethodName.substring(0, classAndMethodName.lastIndexOf('.'));
32 String methodname = classAndMethodName.substring(classAndMethodName.lastIndexOf('.') + 1);
33 visitJavaClass(repo.loadClass(classname));
34 Field[] meths = repo.loadClass(classname).getFields();
35 for(int i=0; i<meths.length; i++)
36 if (meths[i].getName().equals(methodname))
37 visitJavaField(meths[i]);
41 public void loadMethod(String classAndMethodName) throws Exception {
42 String classname = classAndMethodName.substring(0, classAndMethodName.lastIndexOf('.'));
43 String methodname = classAndMethodName.substring(classAndMethodName.lastIndexOf('.') + 1);
44 if (classname.endsWith("." + methodname)) methodname = "<init>";
45 visitJavaClass(repo.loadClass(classname));
46 Method[] meths = getMethods(repo.loadClass(classname));
47 for(int i=0; i<meths.length; i++)
48 if (meths[i].getName().equals(methodname))
49 visitJavaMethod(repo.loadClass(classname), meths[i]);
51 public static void main(String[] s) throws Exception {
53 if (s.length >= 3 && s[1].equals("-o")) { outdir = s[2]; start += 2; }
54 repo = SyntheticRepository.getInstance(new ClassPath(s[0]));
56 BytecodePruner bcp = new BytecodePruner();
57 for(int i=start; i<s.length; i++) {
59 if (s[i].endsWith(".class")) {
60 bcp.visitJavaClass(repo.loadClass(s[i].substring(0, s[i].length() - 6)));
62 JavaClass cl = repo.loadClass(s[i].substring(0, s[i].lastIndexOf('.')));;
63 bcp.visitJavaClass(cl);
66 } catch (Exception e) {
67 System.out.println("WARNING: couldn't load class for " + s[i]);
71 System.out.println("\n\n======================================================================\n");
73 // we call start(), but the VM calls run()...
74 bcp.loadMethod("java.lang.Thread.run");
75 bcp.loadAllMethods("java.lang.SecurityContext");
76 bcp.loadAllMethods("java.lang.ThreadDeath");
78 bcp.loadAllMethods("java.util.Hashtable$HashIterator");
79 bcp.loadMethod("java.util.SimpleTimeZone.useDaylightTime");
80 bcp.visitJavaClass(repo.loadClass("gnu.gcj.runtime.FinalizerThread"));
81 bcp.visitJavaClass(repo.loadClass("gnu.gcj.runtime.FirstThread"));
83 bcp.loadMethod("java.lang.Thread.run"); // we call start(), but the VM calls run()...
84 bcp.loadMethod("java.lang.ref.Reference.enqueue"); // the GC calls this directly
85 bcp.loadAllMethods("gnu.gcj.runtime.StringBuffer"); // the compiler emits calls directly to this class
86 bcp.loadAllMethods("gnu.gcj.convert.Input_UTF8"); // retrieved via reflection
87 bcp.loadAllMethods("gnu.gcj.convert.Output_UTF8"); // retrieved via reflection
89 bcp.loadAllMethods("gnu.gcj.protocol.http.Handler");
90 bcp.loadAllMethods("gnu.gcj.protocol.file.Handler");
91 bcp.loadAllMethods("gnu.gcj.protocol.core.Handler");
92 bcp.loadAllMethods("gnu.gcj.protocol.jar.Handler");
95 bcp.loadAllMethods("java.util.Date");
96 bcp.loadAllMethods("java.text.DateFormat");
97 bcp.loadAllMethods("java.text.NumberFormat");
100 Method[] meths = getMethods(repo.loadClass("org.ibex.plat.Linux"));
101 for(int i=0; i<meths.length; i++) {
102 if (meths[i].getName().equals("main"))
103 bcp.visitJavaMethod(repo.loadClass("org.ibex.plat.Linux"), meths[i]);
105 System.out.println();
107 // FIXME: insert "the null class" when eliminating?
108 System.out.println("Dumping...");
110 StringTokenizer st = new StringTokenizer(s[0], ":");
111 while(st.hasMoreTokens()) {
112 ZipFile zf = new ZipFile(st.nextToken());
113 Enumeration e = zf.entries();
114 while(e.hasMoreElements()) {
115 String ss = ((ZipEntry)e.nextElement()).getName();
116 if (!ss.endsWith(".class")) continue;
117 ss = ss.substring(0, ss.length() - 6);
118 ss = ss.replace('/', '.');
119 dump(repo.loadClass(ss));
124 public static void dump(JavaClass clazz) throws Exception {
125 if (!dest.contains(clazz)) return;
127 ConstantPoolGen newcpg = new ConstantPoolGen(clazz.getConstantPool());
128 ClassGen cg = new ClassGen(clazz);
129 InstructionFactory factory = new InstructionFactory(cg, newcpg);
132 cg.setConstantPool(newcpg);
134 boolean constructed = false;
135 Method[] methods = getMethods(clazz);
136 for(int i=0; i<methods.length; i++)
137 if (dest.contains(methods[i]) && methods[i].getName().equals("<init>"))
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]);
148 if (!constructed && !fields[i].isStatic()) {
149 System.out.println(" unconstructed: pruning field " + clazz.getClassName() + "." + fields[i].getName());
150 //cg.removeField(fields[i]);
155 boolean good = false;
156 for(int i=0; i<methods.length; i++) {
157 if (dest.contains(methods[i]) && (constructed || !methods[i].isStatic())) {
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 // FIXME: remove this
190 System.out.println("DROPPING " + clazz.getClassName());
192 new File(outdir + "/" + new File(clazz.getClassName().replace('.', '/')).getParent()).mkdirs();
193 System.out.println("dumping " + clazz.getClassName());
194 cg.getJavaClass().dump(outdir + "/" + clazz.getClassName().replace('.', '/') + ".class");
198 public JavaClass sig2class(String sig) throws Exception {
199 if (sig == null) return null;
200 while (sig.length() > 0 && (sig.charAt(0) == 'L' || sig.charAt(0) == '[')) {
201 if (sig.charAt(0) == 'L') sig = sig.substring(1, sig.length() - 1);
202 else if (sig.charAt(0) == '[') sig = sig.substring(1, sig.length());
204 if (sig.length() <= 1) return null;
205 if (sig.equals("<null object>")) return null;
206 if (sig.startsWith("<return address")) return null;
207 return repo.loadClass(sig);
209 public void load(String sig) throws Exception {
210 if (sig == null) return;
211 while (sig.length() > 0 && (sig.charAt(0) == 'L' || sig.charAt(0) == '[')) {
212 if (sig.charAt(0) == 'L') sig = sig.substring(1, sig.length() - 1);
213 else if (sig.charAt(0) == '[') sig = sig.substring(1, sig.length());
215 if (sig.length() <= 1) return;
216 if (sig.equals("<null object>")) return;
217 if (sig.startsWith("<return address")) return;
218 visitJavaClass(repo.loadClass(sig));
220 public void load(Type t) throws Exception {
221 if (t == null) return;
222 if (t instanceof ArrayType) load(((ArrayType)t).getElementType());
223 if (!(t instanceof ObjectType)) return;
224 load(((ObjectType)t).getClassName());
227 public String getMethodSignature(Method m, ConstantPoolGen cpg) throws Exception { return m.getName() + m.getSignature(); }
228 public String getMethodSignature(InvokeInstruction ii, ConstantPoolGen cpg) throws Exception {
230 Type[] argtypes = ii.getArgumentTypes(cpg);
231 for(int j=0; j<argtypes.length; j++) sig += argtypes[j].getSignature();
232 return ii.getMethodName(cpg) + "(" + sig + ")" + ii.getReturnType(cpg).getSignature();
235 public void visitJavaMethod(JavaClass jc, Method method) throws Exception {
237 if (jc.getClassName().indexOf("SharedLib") != -1) return;
238 if (jc.getClassName().indexOf("Datagram") != -1) return;
240 // gcj bug; gcj can't compile this method from a .class file input; I have no idea why
241 if (jc.getClassName().equals("java.lang.System") && method.getName().equals("runFinalizersOnExit")) return;
243 if (dest.contains(method)) return;
246 for(int i=0; i<level; i++) System.out.print(" ");
247 ConstantPoolGen cpg = new ConstantPoolGen(method.getConstantPool());
248 System.out.println(jc.getClassName() + "." + getMethodSignature(method, cpg));
249 markMethodInSubclasses(jc, method, cpg);
250 if (method.getCode() == null) { level -= 2; return; }
251 byte[] code = method.getCode().getCode();
252 InstructionList il = new InstructionList(code);
253 Instruction[] instructions = il.getInstructions();
254 for(int i=0; i<instructions.length; i++){
255 Instruction instr = instructions[i];
256 if (instr instanceof LoadClass) load(((LoadClass)instr).getLoadClassType(cpg));
257 if (instr instanceof CPInstruction) load(((CPInstruction)instr).getType(cpg));
258 if (instr instanceof TypedInstruction) {
259 try { load(((TypedInstruction)instr).getType(cpg)); } catch (Exception e) { /* DELIBERATE */ }
261 if (instr instanceof NEW) {
262 for(int j=0; j<level; j++) System.out.print(" ");
263 loadMethod(((NEW)instr).getLoadClassType(cpg).getClassName() + ".<init>");
265 if (instr instanceof org.apache.bcel.generic.FieldOrMethod)
266 load(((org.apache.bcel.generic.FieldOrMethod)instr).getClassType(cpg));
267 if (instr instanceof org.apache.bcel.generic.FieldInstruction) {
268 load(((org.apache.bcel.generic.FieldInstruction)instr).getFieldType(cpg));
269 load(((org.apache.bcel.generic.FieldInstruction)instr).getType(cpg));
270 String fieldName = ((org.apache.bcel.generic.FieldInstruction)instr).getFieldName(cpg);
271 JavaClass jc2 = repo.loadClass(((ObjectType)((org.apache.bcel.generic.FieldInstruction)instr).
272 getLoadClassType(cpg)).getClassName());
273 Field[] fields = jc2.getFields();
274 for(int j=0; j<fields.length; j++) if (fields[j].getName().equals(fieldName)) visitJavaField(fields[j]);
276 if (instr instanceof InvokeInstruction) {
277 InvokeInstruction ii = (InvokeInstruction)instr;
278 String ii_sig = getMethodSignature(ii, cpg);
279 JavaClass c = sig2class(ii.getLoadClassType(cpg).getSignature());
282 load(ii.getReturnType(cpg));
284 load(ii.getType(cpg));
285 Method[] meths = getMethods(c);
286 boolean good = false;
287 for(int i2=0; i2<meths.length; i2++) {
288 if (getMethodSignature(meths[i2], cpg).equals(ii_sig)) {
289 visitJavaMethod(c, meths[i2]);
294 if (!good) throw new Exception("couldn't find method " + getMethodSignature(ii, cpg) + " in " + c.getClassName());
299 // FIXME: move this to the top
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);
337 if (clazz.getClassName().startsWith("org.ibex.")) 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 Method[] methods = getMethods(clazz);
349 for(int i=0; i<methods.length; i++) {
350 if (methods[i].getName().equals("<clinit>")) visitJavaMethod(clazz, methods[i]);
351 if (methods[i].getName().equals("equals")) visitJavaMethod(clazz, methods[i]);
352 if (methods[i].getName().equals("hashCode")) visitJavaMethod(clazz, methods[i]);
353 if (methods[i].getName().equals("finalize")) visitJavaMethod(clazz, methods[i]);
354 if (methods[i].getName().equals("clone")) visitJavaMethod(clazz, methods[i]);
355 if (methods[i].getName().equals("toString")) visitJavaMethod(clazz, methods[i]);
359 public void markMethodInSubclasses(JavaClass c, Method m, JavaClass subclass, ConstantPoolGen cpg) throws Exception {
360 if (m.isStatic()) return;
361 String sig = getMethodSignature(m, cpg);
362 Method[] submethods = getMethods(subclass);
363 for(int j=0; j<submethods.length; j++)
364 if (getMethodSignature(submethods[j], cpg).equals(sig))
365 visitJavaMethod(subclass, submethods[j]);
367 public void markMethodInSubclasses(JavaClass c, Method m, ConstantPoolGen cpg) throws Exception {
368 if (m.isStatic()) return;
369 HashSet s = (HashSet)subclasses.get(c);
370 if (s == null) return;
371 Object[] subclasses = s.toArray();
372 for(int i=0; i<subclasses.length; i++) {
373 JavaClass subclass = (JavaClass)subclasses[i];
374 if (subclass == c) continue;
375 //for(int j=0; j<level; j++) System.out.print(" ");
376 //System.out.println(" [subclass " + subclass.getClassName() + "]");
377 markMethodInSubclasses(c, m, subclass, cpg);
381 public void remarkMethods(JavaClass c, ConstantPoolGen cpg) throws Exception {
382 Method[] meths =getMethods(c);
383 for(int j=0; j<meths.length; j++) if (dest.contains(meths[j])) markMethodInSubclasses(c, meths[j], cpg);
386 public void remarkMethods(JavaClass c, JavaClass target, ConstantPoolGen cpg) throws Exception {
387 Method[] meths = getMethods(c);
388 for(int j=0; j<meths.length; j++) if (dest.contains(meths[j])) markMethodInSubclasses(c, meths[j], target, cpg);
391 public static Hashtable methodsHashtable = new Hashtable();
392 public static Method[] getMethods(JavaClass c) {
393 Method[] ret = (Method[])methodsHashtable.get(c);
394 if (ret == null) methodsHashtable.put(c, ret = c.getMethods());