import org.apache.bcel.classfile.*;
import org.apache.bcel.util.*;
-// Reachability rules:
-
-// - a constructor is reachable iff it is called
-// - a static method is reachable iff it is called
-// - a nonstatic method is reachable
-// - a static field is reachable iff it is referenced
-// - a nonstatic field is reachable iff it is referenced
-// - <clinit> is reachable iff any methods, static methods, fields, or constructors are reachable
-
-// - if a method is reachable, all the methods it overrides are reachable
-
-// FIXME: nonstatic method invocation or field access implies that object will be constructed (ie hint)
-
+// Field pruning
public class BytecodePruner {
+ public static final boolean deleteMethods = false;
+
// FIXME
public static SyntheticRepository repo = null;
public void loadAllMethods(String classname) throws Exception {
visitJavaClass(repo.loadClass(classname));
- Method[] meths = repo.loadClass(classname).getMethods();
- for(int i=0; i<meths.length; i++) visitJavaMethod(repo.loadClass(classname), meths[i]);
+ Method[] meths = getMethods(repo.loadClass(classname));
+ for(int i=0; i<meths.length; i++)
+ visitJavaMethod(repo.loadClass(classname), meths[i]);
}
+
+ public void loadField(String classAndMethodName) throws Exception {
+ String classname = classAndMethodName.substring(0, classAndMethodName.lastIndexOf('.'));
+ String methodname = classAndMethodName.substring(classAndMethodName.lastIndexOf('.') + 1);
+ visitJavaClass(repo.loadClass(classname));
+ Field[] meths = repo.loadClass(classname).getFields();
+ for(int i=0; i<meths.length; i++)
+ if (meths[i].getName().equals(methodname))
+ visitJavaField(meths[i]);
+ }
+
+
public void loadMethod(String classAndMethodName) throws Exception {
String classname = classAndMethodName.substring(0, classAndMethodName.lastIndexOf('.'));
String methodname = classAndMethodName.substring(classAndMethodName.lastIndexOf('.') + 1);
visitJavaClass(repo.loadClass(classname));
- Method[] meths = repo.loadClass(classname).getMethods();
+ Method[] meths = getMethods(repo.loadClass(classname));
for(int i=0; i<meths.length; i++)
if (meths[i].getName().equals(methodname))
visitJavaMethod(repo.loadClass(classname), meths[i]);
int start = 1;
if (s.length >= 3 && s[1].equals("-o")) { outdir = s[2]; start += 2; }
repo = SyntheticRepository.getInstance(new ClassPath(s[0]));
- BytecodePruner bcp = new BytecodePruner();
+ BytecodePruner bcp = new BytecodePruner();
for(int i=start; i<s.length; i++) {
try {
if (s[i].endsWith(".class")) {
} else {
JavaClass cl = repo.loadClass(s[i].substring(0, s[i].lastIndexOf('.')));;
bcp.visitJavaClass(cl);
- Method[] meths = cl.getMethods();
+ Method[] meths = getMethods(cl);
for(int j=0; j<meths.length; j++) {
if (meths[j].getName().equals(s[i].substring(s[i].lastIndexOf('.') + 1)))
bcp.visitJavaMethod(cl, meths[j]);
System.out.println("WARNING: couldn't load class for " + s[i]);
}
}
+
System.out.println("\n\n======================================================================\n");
// we call start(), but the VM calls run()...
bcp.loadMethod("java.lang.Thread.run");
+ bcp.loadAllMethods("java.lang.SecurityContext");
+ //bcp.visitJavaClass(repo.loadClass("java.awt.AWTPermission"));
+ //bcp.visitJavaClass(repo.loadClass("gnu.classpath.Configuration"));
+ bcp.loadAllMethods("java.lang.ThreadDeath");
- bcp.loadAllMethods("java.lang.Throwable");
- bcp.loadAllMethods("java.io.PrintStream");
- bcp.loadAllMethods("gnu.gcj.runtime.StringBuffer");
- bcp.loadAllMethods("java.security.cert.Certificate");
-
+ bcp.loadAllMethods("java.util.Hashtable$HashIterator");
bcp.loadMethod("java.util.SimpleTimeZone.useDaylightTime");
- bcp.loadMethod("java.util.TimeZone.getAvailableIDs");
- bcp.loadMethod("java.util.TimeZone.getDefaultTimeZoneId");
- bcp.loadMethod("java.util.Collections$SynchronizedIterator.hasNext");
- bcp.loadMethod("java.util.Hashtable$HashIterator.hasNext");
-
- bcp.visitJavaClass(repo.loadClass("java.util.Stack"));
- bcp.visitJavaClass(repo.loadClass("gnu.classpath.Configuration"));
- bcp.visitJavaClass(repo.loadClass("gnu.gcj.runtime.JNIWeakRef"));
-
- bcp.visitJavaClass(repo.loadClass("gnu.gcj.protocol.http.Handler"));
- bcp.visitJavaClass(repo.loadClass("gnu.gcj.protocol.file.Handler"));
- bcp.visitJavaClass(repo.loadClass("gnu.gcj.protocol.jar.Handler"));
- bcp.visitJavaClass(repo.loadClass("gnu.gcj.protocol.core.Handler"));
bcp.visitJavaClass(repo.loadClass("gnu.gcj.runtime.FinalizerThread"));
bcp.visitJavaClass(repo.loadClass("gnu.gcj.runtime.FirstThread"));
- // SecurityManager hacks to avoid java.security?
- // URL and all descendents? Probably impossible.
- // ObjectInput/ObjectOutput? Serialization?
-
- // often called from native subclasses....
- bcp.loadAllMethods("org.ibex.Surface");
- bcp.loadAllMethods("org.ibex.Picture");
- bcp.loadAllMethods("org.ibex.PixelBuffer");
- bcp.loadAllMethods("org.ibex.Platform");
- bcp.loadAllMethods("org.ibex.Scheduler");
- bcp.loadAllMethods("org.ibex.plat.X11");
- bcp.loadAllMethods("org.ibex.plat.X11$X11Picture");
- bcp.loadAllMethods("org.ibex.plat.X11$X11PixelBuffer");
- bcp.loadAllMethods("org.ibex.plat.X11$X11Surface");
- bcp.loadAllMethods("org.ibex.XMLRPC");
-
+ bcp.loadMethod("java.lang.Thread.run"); // we call start(), but the VM calls run()...
+ bcp.loadMethod("java.lang.ref.Reference.enqueue"); // the GC calls this directly
+ bcp.loadAllMethods("gnu.gcj.runtime.StringBuffer"); // the compiler emits calls directly to this class
+
+ bcp.loadAllMethods("gnu.gcj.protocol.http.Handler");
+ bcp.loadAllMethods("gnu.gcj.protocol.file.Handler");
+ bcp.loadAllMethods("gnu.gcj.protocol.core.Handler");
+ bcp.loadAllMethods("gnu.gcj.protocol.jar.Handler");
+ bcp.loadAllMethods("gnu.gcj.convert.Input_UTF8"); // retrieved via reflection
+ bcp.loadAllMethods("gnu.gcj.convert.Output_UTF8"); // retrieved via reflection
+ bcp.loadAllMethods("gnu.gcj.convert.Input_8859_1"); // retrieved via reflection
+ bcp.loadAllMethods("gnu.gcj.convert.Output_8859_1"); // retrieved via reflection
+ bcp.loadAllMethods("gnu.gcj.convert.Input_ASCII"); // retrieved via reflection
+ bcp.loadAllMethods("gnu.gcj.convert.Output_ASCII"); // retrieved via reflection
+
bcp.loadAllMethods("java.util.Date");
bcp.loadAllMethods("java.text.DateFormat");
bcp.loadAllMethods("java.text.NumberFormat");
-
- Method[] meths = repo.loadClass("org.ibex.plat.Linux").getMethods();
+ Method[] meths = getMethods(repo.loadClass("org.ibex.plat.Linux"));
for(int i=0; i<meths.length; i++) {
if (meths[i].getName().equals("main"))
bcp.visitJavaMethod(repo.loadClass("org.ibex.plat.Linux"), meths[i]);
}
System.out.println();
-
System.out.println("Dumping...");
StringTokenizer st = new StringTokenizer(s[0], ":");
public BytecodePruner() { }
public static void dump(JavaClass clazz) throws Exception {
- if (clazz.getClassName().startsWith("java.sql.")) return;
+ if (!dest.contains(clazz)) return;
ConstantPoolGen newcpg = new ConstantPoolGen(clazz.getConstantPool());
ClassGen cg = new ClassGen(clazz);
cg.setMajor(46);
cg.setMinor(0);
cg.setConstantPool(newcpg);
+
+ // we can only prune static fields (to avoid altering object layout, which is hardcoded into
+ // CNI code), but that's okay since instance fields don't contribute to binary size
Field[] fields = clazz.getFields();
- int numFields = 0;
for(int i=0; i<fields.length; i++)
- if (!dest.contains(fields[i]) && false) {
- System.out.println(" pruning " + clazz.getClassName() + "." + fields[i].getName());
- fields[i] = null;
- } else numFields++;
+ if (!dest.contains(fields[i]) && fields[i].isStatic()) {
+ System.out.println(" pruning field " + clazz.getClassName() + "." + fields[i].getName());
+ cg.removeField(fields[i]);
+ }
- // superprune: URLClassLoader, convert.In/Output other than needed, unneeded locales
- // reflective metadata is killing us...
-
- Method[] methods = clazz.getMethods();
+ Method[] methods = getMethods(clazz);
int numMethods = 0;
boolean good = false;
- for(int i=0; i<methods.length; i++)
- if (clazz.getClassName().startsWith("gnu.")
+ for(int i=0; i<methods.length; i++) {
+ if (dest.contains(methods[i]) ||
+ clazz.getClassName().startsWith("java.io.FileDescriptor")
+ || clazz.getClassName().startsWith("gnu.gcj.runtime.")
|| clazz.getClassName().startsWith("java.lang.")
- || clazz.getClassName().startsWith("java.io.")
- || clazz.getClassName().startsWith("org.ibex.")) {
- good = true;
- } else if (dest.contains(methods[i])) {
+ ) {
if (!methods[i].getName().equals("<clinit>")) good = true;
} else {
- if (methods[i].getCode() != null) {
+ if (methods[i].getCode() == null) {
+ System.out.println(" empty codeblock: " + clazz.getClassName() + "." + methods[i].getName());
+ } else {
System.out.println(" pruning " + clazz.getClassName() + "." + methods[i].getName());
+ if (deleteMethods) { cg.removeMethod(methods[i]); continue; }
MethodGen mg = new MethodGen(methods[i], clazz.getClassName(), newcpg);
mg.removeExceptions();
InstructionList il = new InstructionList();
mg.setInstructionList(il);
-
InstructionHandle ih_0 = il.append(factory.createNew("java.lang.UnsatisfiedLinkError"));
il.append(InstructionConstants.DUP);
il.append(factory.createInvoke("java.lang.UnsatisfiedLinkError",
- "<init>", Type.VOID, Type.NO_ARGS, Constants.INVOKESPECIAL));
+ "<init>", Type.VOID, Type.NO_ARGS, Constants.INVOKESPECIAL));
il.append(InstructionConstants.ATHROW);
-
mg.setMaxStack();
mg.setMaxLocals();
mg.removeExceptions();
mg.removeLocalVariables();
mg.removeExceptionHandlers();
mg.removeLineNumbers();
-
cg.replaceMethod(methods[i], mg.getMethod());
il.dispose();
}
}
- if ((clazz.getClassName().startsWith("gnu.java.locale.LocaleInformation") &&
- !clazz.getClassName().endsWith("LocaleInformation_en") &&
- !clazz.getClassName().endsWith("LocaleInformation") &&
- !clazz.getClassName().endsWith("LocaleInformation_en_US"))
- ||
- (!good &&
- !clazz.isInterface() &&
- !clazz.isAbstract() &&
- !clazz.getClassName().endsWith("Error") &&
- !clazz.getClassName().endsWith("Exception") &&
- !clazz.getClassName().endsWith("Permission"))) {
-
- System.out.println("DROPPING " + clazz.getClassName());
- return;
}
+
new File(outdir + "/" + new File(clazz.getClassName().replace('.', '/')).getParent()).mkdirs();
System.out.println("dumping " + clazz.getClassName());
cg.getJavaClass().dump(outdir + "/" + clazz.getClassName().replace('.', '/') + ".class");
}
public void load(Type t) throws Exception {
if (t == null) return;
- //String sig = t.getSignature();
if (t instanceof ArrayType) load(((ArrayType)t).getElementType());
if (!(t instanceof ObjectType)) return;
load(((ObjectType)t).getClassName());
// hashtable of hashsets
public static Hashtable subclasses = new Hashtable();
- public String getMethodSignature(Method m) throws Exception {
- ConstantPoolGen cpg = new ConstantPoolGen(m.getConstantPool());
+ public String getMethodSignature(Method m, ConstantPoolGen cpg) throws Exception {
return m.getName() + m.getSignature();
}
for(int j=0; j<argtypes.length; j++) sig += argtypes[j].getSignature();
return ii.getMethodName(cpg) + "(" + sig + ")" + ii.getReturnType(cpg).getSignature();
}
+
public static int level = 0;
public void visitJavaMethod(JavaClass jc, Method method) throws Exception {
visitJavaClass(jc);
+ /*
+ if (jc.getClassName().equals("java.util.Date") && method.getName().equals("readObject")) return;
+ */
+ if (jc.getClassName().indexOf("SharedLib") != -1) return;
+ if (jc.getClassName().indexOf("Datagram") != -1) return;
if (dest.contains(method)) return;
+
+ /*
+ // HACK (okay?)
+ // not inferrable: CNI call to abstract method
+ if (jc.getClassName().equals("java.util.TimeZone") && method.getName().equals("getDefaultTimeZoneId"))
+ loadMethod("java.util.SimpleTimeZone.useDaylightTime");
+ */
+
dest.add(method);
level += 2;
for(int i=0; i<level; i++) System.out.print(" ");
- System.out.println(jc.getClassName() + "." + getMethodSignature(method));
- markMethodInSubclasses(jc, method);
ConstantPoolGen cpg = new ConstantPoolGen(method.getConstantPool());
+ System.out.println(jc.getClassName() + "." + getMethodSignature(method, cpg));
+ markMethodInSubclasses(jc, method, cpg);
if (method.getCode() == null) { level -= 2; return; }
byte[] code = method.getCode().getCode();
InstructionList il = new InstructionList(code);
Instruction instr = instructions[i];
if (instr instanceof LoadClass) load(((LoadClass)instr).getLoadClassType(cpg));
if (instr instanceof CPInstruction) load(((CPInstruction)instr).getType(cpg));
+ if (instr instanceof TypedInstruction) {
+ try { load(((TypedInstruction)instr).getType(cpg)); } catch (Exception e) { /* DELIBERATE */ }
+ }
+ if (instr instanceof NEW) {
+ for(int j=0; j<level; j++) System.out.print(" ");
+ loadMethod(((NEW)instr).getLoadClassType(cpg).getClassName() + ".<init>");
+ }
+ if (instr instanceof org.apache.bcel.generic.FieldOrMethod)
+ load(((org.apache.bcel.generic.FieldOrMethod)instr).getClassType(cpg));
+ if (instr instanceof org.apache.bcel.generic.FieldInstruction) {
+ load(((org.apache.bcel.generic.FieldInstruction)instr).getFieldType(cpg));
+ load(((org.apache.bcel.generic.FieldInstruction)instr).getType(cpg));
+ String fieldName = ((org.apache.bcel.generic.FieldInstruction)instr).getFieldName(cpg);
+ JavaClass jc2 = repo.loadClass(((ObjectType)((org.apache.bcel.generic.FieldInstruction)instr).
+ getLoadClassType(cpg)).getClassName());
+ Field[] fields = jc2.getFields();
+ for(int j=0; j<fields.length; j++) if (fields[j].getName().equals(fieldName)) visitJavaField(fields[j]);
+ }
if (instr instanceof InvokeInstruction) {
InvokeInstruction ii = (InvokeInstruction)instr;
String ii_sig = getMethodSignature(ii, cpg);
JavaClass c = sig2class(ii.getLoadClassType(cpg).getSignature());
load(ii.getReturnType(cpg));
load(ii.getType(cpg));
- Method[] meths = c.getMethods();
+ Method[] meths = getMethods(c);
boolean good = false;
for(int i2=0; i2<meths.length; i2++) {
- if (getMethodSignature(meths[i2]).equals(ii_sig)) {
+ if (getMethodSignature(meths[i2], cpg).equals(ii_sig)) {
visitJavaMethod(c, meths[i2]);
good = true;
break;
}
- }
- if (!good)
- throw new Exception("couldn't find method " + getMethodSignature(ii, cpg) + " in " + c.getClassName());
+ }
+ if (!good) throw new Exception("couldn't find method " + getMethodSignature(ii, cpg) + " in " + c.getClassName());
}
}
level -= 2;
}
public void visitJavaClass(JavaClass clazz) throws Exception {
-
if (dest.contains(clazz)) return;
dest.add(clazz);
+ ConstantPoolGen cpg = new ConstantPoolGen(clazz.getConstantPool());
String name = clazz.getClassName();
+ System.out.println(clazz.getClassName() + ".class");
JavaClass superclass = clazz.getSuperClass();
-
JavaClass[] interfaces = clazz.getAllInterfaces();
+ for(JavaClass sup = superclass; sup != null; sup = sup.getSuperClass()) {
+ if (subclasses.get(sup) == null) subclasses.put(sup, new HashSet());
+ ((HashSet)subclasses.get(sup)).add(clazz);
+ }
+ for(int i=0; i<interfaces.length; i++) {
+ if (subclasses.get(interfaces[i]) == null) subclasses.put(interfaces[i], new HashSet());
+ ((HashSet)subclasses.get(interfaces[i])).add(clazz);
+ }
+
+ if (clazz.getClassName().startsWith("org.ibex."))
+ loadAllMethods(clazz.getClassName());
+
+ for(JavaClass sup = superclass; sup != null; sup = sup.getSuperClass()) {
+ visitJavaClass(sup);
+ remarkMethods(sup, clazz, cpg);
+ }
+ for(int i=0; i<interfaces.length; i++) {
+ visitJavaClass(interfaces[i]);
+ remarkMethods(interfaces[i], clazz, cpg);
+ }
+
Field[] fields = clazz.getFields();
- Method[] methods = clazz.getMethods();
- System.out.println(clazz.getClassName() + ".class");
- for(int i=0; i<methods.length; i++)
- if (methods[i].getName().equals("<clinit>")) visitJavaMethod(clazz, methods[i]);
+ for(int i=0; i<fields.length; i++) {
+ if (!fields[i].isStatic())
+ visitJavaField(fields[i]);
+ }
+
+ Method[] methods = getMethods(clazz);
for(int i=0; i<methods.length; i++) {
+ if (methods[i].getName().equals("<clinit>")) visitJavaMethod(clazz, methods[i]);
+ // only if ctor reachable (?)
if (methods[i].getName().equals("equals")) visitJavaMethod(clazz, methods[i]);
if (methods[i].getName().equals("hashCode")) visitJavaMethod(clazz, methods[i]);
if (methods[i].getName().equals("finalize")) visitJavaMethod(clazz, methods[i]);
if (methods[i].getName().equals("clone")) visitJavaMethod(clazz, methods[i]);
if (methods[i].getName().equals("toString")) visitJavaMethod(clazz, methods[i]);
}
- for(int i=0; i<fields.length; i++) visitJavaField(fields[i]);
- if (superclass != null) {
- for(JavaClass sup = superclass; sup != null; sup = sup.getSuperClass()) {
- if (subclasses.get(sup) == null) subclasses.put(sup, new HashSet());
- ((HashSet)subclasses.get(sup)).add(clazz);
- visitJavaClass(sup);
- remarkMethods(sup, clazz);
- }
- }
- for(int i=0; i<interfaces.length; i++) {
- if (subclasses.get(interfaces[i]) == null) subclasses.put(interfaces[i], new HashSet());
- ((HashSet)subclasses.get(interfaces[i])).add(clazz);
- visitJavaClass(interfaces[i]);
- remarkMethods(interfaces[i], clazz);
- }
}
- public void markMethodInSubclasses(JavaClass c, Method m, JavaClass subclass) throws Exception {
+ public void markMethodInSubclasses(JavaClass c, Method m, JavaClass subclass, ConstantPoolGen cpg) throws Exception {
if (m.isStatic()) return;
- String sig = getMethodSignature(m);
- Method[] submethods = subclass.getMethods();
+ String sig = getMethodSignature(m, cpg);
+ Method[] submethods = getMethods(subclass);
for(int j=0; j<submethods.length; j++)
- if (getMethodSignature(submethods[j]).equals(sig))
+ if (getMethodSignature(submethods[j], cpg).equals(sig))
visitJavaMethod(subclass, submethods[j]);
}
- public void markMethodInSubclasses(JavaClass c, Method m) throws Exception {
+ public void markMethodInSubclasses(JavaClass c, Method m, ConstantPoolGen cpg) throws Exception {
if (m.isStatic()) return;
HashSet s = (HashSet)subclasses.get(c);
if (s == null) return;
Object[] subclasses = s.toArray();
for(int i=0; i<subclasses.length; i++) {
JavaClass subclass = (JavaClass)subclasses[i];
- if (subclass == c) return;
- markMethodInSubclasses(c, m, subclass);
+ if (subclass == c) continue;
+ for(int j=0; j<level; j++) System.out.print(" ");
+ System.out.println(" [subclass " + subclass.getClassName() + "]");
+ markMethodInSubclasses(c, m, subclass, cpg);
}
}
- public void remarkMethods(JavaClass c) throws Exception {
- Method[] meths = c.getMethods();
- for(int j=0; j<meths.length; j++) if (dest.contains(meths[j])) markMethodInSubclasses(c, meths[j]);
+ public void remarkMethods(JavaClass c, ConstantPoolGen cpg) throws Exception {
+ Method[] meths =getMethods(c);
+ for(int j=0; j<meths.length; j++) if (dest.contains(meths[j])) markMethodInSubclasses(c, meths[j], cpg);
+ }
+
+ public void remarkMethods(JavaClass c, JavaClass target, ConstantPoolGen cpg) throws Exception {
+ Method[] meths = getMethods(c);
+ for(int j=0; j<meths.length; j++) if (dest.contains(meths[j])) markMethodInSubclasses(c, meths[j], target, cpg);
}
- public void remarkMethods(JavaClass c, JavaClass target) throws Exception {
- Method[] meths = c.getMethods();
- for(int j=0; j<meths.length; j++) if (dest.contains(meths[j])) markMethodInSubclasses(c, meths[j], target);
+ public static Hashtable methodsHashtable = new Hashtable();
+ public static Method[] getMethods(JavaClass c) {
+ Method[] ret = (Method[])methodsHashtable.get(c);
+ if (ret == null) methodsHashtable.put(c, ret = c.getMethods());
+ return ret;
}
}