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
90 bcp.loadAllMethods("gnu.gcj.protocol.http.Handler");
91 bcp.loadAllMethods("gnu.gcj.protocol.file.Handler");
92 bcp.loadAllMethods("gnu.gcj.protocol.core.Handler");
93 bcp.loadAllMethods("gnu.gcj.protocol.jar.Handler");
94 bcp.loadAllMethods("gnu.gcj.convert.Input_8859_1"); // retrieved via reflection
95 bcp.loadAllMethods("gnu.gcj.convert.Output_8859_1"); // retrieved via reflection
96 bcp.loadAllMethods("gnu.gcj.convert.Input_ASCII"); // retrieved via reflection
97 bcp.loadAllMethods("gnu.gcj.convert.Output_ASCII"); // retrieved via reflection
100 bcp.loadAllMethods("java.util.Date");
101 bcp.loadAllMethods("java.text.DateFormat");
102 bcp.loadAllMethods("java.text.NumberFormat");
104 Method[] meths = getMethods(repo.loadClass("org.ibex.plat.Linux"));
105 for(int i=0; i<meths.length; i++) {
106 if (meths[i].getName().equals("main"))
107 bcp.visitJavaMethod(repo.loadClass("org.ibex.plat.Linux"), meths[i]);
109 System.out.println();
111 // FIXME: insert "the null class" when eliminating?
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 static void dump(JavaClass clazz) throws Exception {
129 if (!dest.contains(clazz)) return;
131 ConstantPoolGen newcpg = new ConstantPoolGen(clazz.getConstantPool());
132 ClassGen cg = new ClassGen(clazz);
133 InstructionFactory factory = new InstructionFactory(cg, newcpg);
136 cg.setConstantPool(newcpg);
138 boolean constructed = false;
139 Method[] methods = getMethods(clazz);
140 for(int i=0; i<methods.length; i++)
141 if (dest.contains(methods[i]) && methods[i].getName().equals("<init>"))
144 // we can only prune static fields (to avoid altering object layout, which is hardcoded into
145 // CNI code), but that's okay since instance fields don't contribute to binary size
146 Field[] fields = clazz.getFields();
147 for(int i=0; i<fields.length; i++) {
148 if (!dest.contains(fields[i]) && fields[i].isStatic()) {
149 System.out.println(" pruning field " + clazz.getClassName() + "." + fields[i].getName());
150 cg.removeField(fields[i]);
152 if (!constructed && !fields[i].isStatic()) {
153 System.out.println(" unconstructed: pruning field " + clazz.getClassName() + "." + fields[i].getName());
154 //cg.removeField(fields[i]);
159 boolean good = false;
160 for(int i=0; i<methods.length; i++) {
161 if (dest.contains(methods[i]) /*&& (constructed || !methods[i].isStatic())*/) {
162 if (!methods[i].getName().equals("<clinit>")) good = true;
164 if (methods[i].getCode() == null) {
165 System.out.println(" empty codeblock: " + clazz.getClassName() + "." + methods[i].getName());
167 System.out.println(" pruning " + clazz.getClassName() + "." + methods[i].getName());
168 if (deleteMethods) { cg.removeMethod(methods[i]); continue; }
169 MethodGen mg = new MethodGen(methods[i], clazz.getClassName(), newcpg);
170 mg.removeExceptions();
171 InstructionList il = new InstructionList();
172 mg.setInstructionList(il);
173 InstructionHandle ih_0 = il.append(factory.createNew("java.lang.UnsatisfiedLinkError"));
174 il.append(InstructionConstants.DUP);
175 il.append(factory.createInvoke("java.lang.UnsatisfiedLinkError",
176 "<init>", Type.VOID, Type.NO_ARGS, Constants.INVOKESPECIAL));
177 il.append(InstructionConstants.ATHROW);
180 mg.removeExceptions();
181 mg.removeLocalVariables();
182 mg.removeExceptionHandlers();
183 mg.removeLineNumbers();
184 cg.replaceMethod(methods[i], mg.getMethod());
190 // FIXME: remove this
194 System.out.println("DROPPING " + clazz.getClassName());
196 new File(outdir + "/" + new File(clazz.getClassName().replace('.', '/')).getParent()).mkdirs();
197 System.out.println("dumping " + clazz.getClassName());
198 cg.getJavaClass().dump(outdir + "/" + clazz.getClassName().replace('.', '/') + ".class");
202 public JavaClass sig2class(String sig) throws Exception {
203 if (sig == null) return null;
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 null;
209 if (sig.equals("<null object>")) return null;
210 if (sig.startsWith("<return address")) return null;
211 return repo.loadClass(sig);
213 public void load(String sig) throws Exception {
214 if (sig == null) return;
215 while (sig.length() > 0 && (sig.charAt(0) == 'L' || sig.charAt(0) == '[')) {
216 if (sig.charAt(0) == 'L') sig = sig.substring(1, sig.length() - 1);
217 else if (sig.charAt(0) == '[') sig = sig.substring(1, sig.length());
219 if (sig.length() <= 1) return;
220 if (sig.equals("<null object>")) return;
221 if (sig.startsWith("<return address")) return;
222 visitJavaClass(repo.loadClass(sig));
224 public void load(Type t) throws Exception {
225 if (t == null) return;
226 if (t instanceof ArrayType) load(((ArrayType)t).getElementType());
227 if (!(t instanceof ObjectType)) return;
228 load(((ObjectType)t).getClassName());
231 public String getMethodSignature(Method m, ConstantPoolGen cpg) throws Exception { return m.getName() + m.getSignature(); }
232 public String getMethodSignature(InvokeInstruction ii, ConstantPoolGen cpg) throws Exception {
234 Type[] argtypes = ii.getArgumentTypes(cpg);
235 for(int j=0; j<argtypes.length; j++) sig += argtypes[j].getSignature();
236 return ii.getMethodName(cpg) + "(" + sig + ")" + ii.getReturnType(cpg).getSignature();
239 public void visitJavaMethod(JavaClass jc, Method method) throws Exception {
241 if (jc.getClassName().indexOf("SharedLib") != -1) return;
242 if (jc.getClassName().indexOf("Datagram") != -1) return;
244 // gcj bug; gcj can't compile this method from a .class file input; I have no idea why
245 if (jc.getClassName().equals("java.lang.System") && method.getName().equals("runFinalizersOnExit")) return;
247 if (dest.contains(method)) return;
250 for(int i=0; i<level; i++) System.out.print(" ");
251 ConstantPoolGen cpg = new ConstantPoolGen(method.getConstantPool());
252 System.out.println(jc.getClassName() + "." + getMethodSignature(method, cpg));
253 markMethodInSubclasses(jc, method, cpg);
254 if (method.getCode() == null) { level -= 2; return; }
255 byte[] code = method.getCode().getCode();
256 InstructionList il = new InstructionList(code);
257 Instruction[] instructions = il.getInstructions();
258 for(int i=0; i<instructions.length; i++){
259 Instruction instr = instructions[i];
260 if (instr instanceof LoadClass) load(((LoadClass)instr).getLoadClassType(cpg));
261 if (instr instanceof CPInstruction) load(((CPInstruction)instr).getType(cpg));
262 if (instr instanceof TypedInstruction) {
263 try { load(((TypedInstruction)instr).getType(cpg)); } catch (Exception e) { /* DELIBERATE */ }
265 if (instr instanceof NEW) {
266 for(int j=0; j<level; j++) System.out.print(" ");
267 loadMethod(((NEW)instr).getLoadClassType(cpg).getClassName() + ".<init>");
269 if (instr instanceof org.apache.bcel.generic.FieldOrMethod)
270 load(((org.apache.bcel.generic.FieldOrMethod)instr).getClassType(cpg));
271 if (instr instanceof org.apache.bcel.generic.FieldInstruction) {
272 load(((org.apache.bcel.generic.FieldInstruction)instr).getFieldType(cpg));
273 load(((org.apache.bcel.generic.FieldInstruction)instr).getType(cpg));
274 String fieldName = ((org.apache.bcel.generic.FieldInstruction)instr).getFieldName(cpg);
275 JavaClass jc2 = repo.loadClass(((ObjectType)((org.apache.bcel.generic.FieldInstruction)instr).
276 getLoadClassType(cpg)).getClassName());
277 Field[] fields = jc2.getFields();
278 for(int j=0; j<fields.length; j++) if (fields[j].getName().equals(fieldName)) visitJavaField(fields[j]);
280 if (instr instanceof InvokeInstruction) {
281 InvokeInstruction ii = (InvokeInstruction)instr;
282 String ii_sig = getMethodSignature(ii, cpg);
283 JavaClass c = sig2class(ii.getLoadClassType(cpg).getSignature());
286 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());
303 // FIXME: move this to the top
306 load(method.getReturnType());
307 Type[] argtypes = method.getArgumentTypes();
308 for(int i=0; i<argtypes.length; i++) load(argtypes[i]);
309 if (method.getExceptionTable() != null) {
310 String[] exntypes = method.getExceptionTable().getExceptionNames();
311 for(int i=0; i<exntypes.length; i++) load(exntypes[i]);
315 public void visitJavaField(Field field) throws Exception {
316 if (dest.contains(field)) return;
318 load(field.getType());
321 public void visitJavaClass(JavaClass clazz) throws Exception {
322 if (dest.contains(clazz)) return;
325 ConstantPoolGen cpg = new ConstantPoolGen(clazz.getConstantPool());
326 String name = clazz.getClassName();
327 System.out.println(clazz.getClassName() + ".class");
329 JavaClass superclass = clazz.getSuperClass();
330 JavaClass[] interfaces = clazz.getAllInterfaces();
331 for(JavaClass sup = superclass; sup != null; sup = sup.getSuperClass()) {
332 if (subclasses.get(sup) == null) subclasses.put(sup, new HashSet());
333 ((HashSet)subclasses.get(sup)).add(clazz);
335 for(int i=0; i<interfaces.length; i++) {
336 if (subclasses.get(interfaces[i]) == null) subclasses.put(interfaces[i], new HashSet());
337 ((HashSet)subclasses.get(interfaces[i])).add(clazz);
341 if (clazz.getClassName().startsWith("org.ibex.")) loadAllMethods(clazz.getClassName());
343 for(JavaClass sup = superclass; sup != null; sup = sup.getSuperClass()) {
345 remarkMethods(sup, clazz, cpg);
347 for(int i=0; i<interfaces.length; i++) {
348 visitJavaClass(interfaces[i]);
349 remarkMethods(interfaces[i], clazz, cpg);
352 Method[] methods = getMethods(clazz);
353 for(int i=0; i<methods.length; i++) {
354 if (methods[i].getName().equals("<clinit>")) visitJavaMethod(clazz, methods[i]);
355 if (methods[i].getName().equals("equals")) visitJavaMethod(clazz, methods[i]);
356 if (methods[i].getName().equals("hashCode")) visitJavaMethod(clazz, methods[i]);
357 if (methods[i].getName().equals("finalize")) visitJavaMethod(clazz, methods[i]);
358 if (methods[i].getName().equals("clone")) visitJavaMethod(clazz, methods[i]);
359 if (methods[i].getName().equals("toString")) visitJavaMethod(clazz, methods[i]);
363 public void markMethodInSubclasses(JavaClass c, Method m, JavaClass subclass, ConstantPoolGen cpg) throws Exception {
364 if (m.isStatic()) return;
365 String sig = getMethodSignature(m, cpg);
366 Method[] submethods = getMethods(subclass);
367 for(int j=0; j<submethods.length; j++)
368 if (getMethodSignature(submethods[j], cpg).equals(sig))
369 visitJavaMethod(subclass, submethods[j]);
371 public void markMethodInSubclasses(JavaClass c, Method m, ConstantPoolGen cpg) throws Exception {
372 if (m.isStatic()) return;
373 HashSet s = (HashSet)subclasses.get(c);
374 if (s == null) return;
375 Object[] subclasses = s.toArray();
376 for(int i=0; i<subclasses.length; i++) {
377 JavaClass subclass = (JavaClass)subclasses[i];
378 if (subclass == c) continue;
379 //for(int j=0; j<level; j++) System.out.print(" ");
380 //System.out.println(" [subclass " + subclass.getClassName() + "]");
381 markMethodInSubclasses(c, m, subclass, cpg);
385 public void remarkMethods(JavaClass c, ConstantPoolGen cpg) throws Exception {
386 Method[] meths =getMethods(c);
387 for(int j=0; j<meths.length; j++) if (dest.contains(meths[j])) markMethodInSubclasses(c, meths[j], cpg);
390 public void remarkMethods(JavaClass c, JavaClass target, ConstantPoolGen cpg) throws Exception {
391 Method[] meths = getMethods(c);
392 for(int j=0; j<meths.length; j++) if (dest.contains(meths[j])) markMethodInSubclasses(c, meths[j], target, cpg);
395 public static Hashtable methodsHashtable = new Hashtable();
396 public static Method[] getMethods(JavaClass c) {
397 Method[] ret = (Method[])methodsHashtable.get(c);
398 if (ret == null) methodsHashtable.put(c, ret = c.getMethods());