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
-
-// try eliminating instance methods/fields if no ctor is reachable...
-// distinguish between overloaded forms of a given method
-// slim down the set of loadAllMethod() classes
-// field pruning?
-
-// FIXME: nonstatic method invocation or field access implies that object will be constructed (ie hint)
-
public class BytecodePruner {
public static final boolean deleteMethods = false;
-
- // FIXME
public static SyntheticRepository repo = null;
-
public static HashSet dest = new HashSet();
-
public static String outdir = ".";
+ public static Hashtable subclasses = new Hashtable();
+ public static int level = 0;
+
+ public BytecodePruner() { }
public void loadAllMethods(String classname) throws Exception {
visitJavaClass(repo.loadClass(classname));
Method[] meths = getMethods(repo.loadClass(classname));
- for(int i=0; i<meths.length; i++) visitJavaMethod(repo.loadClass(classname), meths[i]);
+ 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);
+ if (classname.endsWith("." + methodname)) methodname = "<init>";
visitJavaClass(repo.loadClass(classname));
Method[] meths = getMethods(repo.loadClass(classname));
for(int i=0; i<meths.length; i++)
} else {
JavaClass cl = repo.loadClass(s[i].substring(0, s[i].lastIndexOf('.')));;
bcp.visitJavaClass(cl);
- 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]);
- }
+ bcp.loadMethod(s[i]);
}
} catch (Exception e) {
System.out.println("WARNING: couldn't load class for " + s[i]);
// 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.util.Hashtable$HashIterator");
bcp.loadMethod("java.util.SimpleTimeZone.useDaylightTime");
- /*
- bcp.loadAllMethods("java.lang.Throwable");
- bcp.loadAllMethods("java.io.PrintStream");
- bcp.loadAllMethods("java.util.PropertyPermission");
- bcp.loadAllMethods("java.security.cert.Certificate");
- bcp.loadAllMethods("java.security.cert.CertificateEncodingException");
- bcp.loadMethod("java.util.TimeZone.getAvailableIDs");
- bcp.loadMethod("java.util.TimeZone.getDefaultTimeZoneId");
- bcp.loadAllMethods("gnu.gcj.runtime.StringBuffer");
- bcp.loadAllMethods("gnu.gcj.runtime.VMClassLoader");
- 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?
+ 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.convert.Input_UTF8"); // retrieved via reflection
+ bcp.loadAllMethods("gnu.gcj.convert.Output_UTF8"); // retrieved via reflection
- // often called from native subclasses....
+ 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");
+
+ // to ensure we get all the stuff that might be called from CNI
+ bcp.loadAllMethods("org.ibex.plat.Linux");
+ bcp.loadAllMethods("org.ibex.plat.X11");
+ bcp.loadAllMethods("org.ibex.plat.GCJ");
+ bcp.loadAllMethods("org.ibex.plat.POSIX");
+ bcp.loadAllMethods("org.ibex.plat.X11$X11Surface");
+ bcp.loadAllMethods("org.ibex.plat.X11$X11PixelBuffer");
+ bcp.loadAllMethods("org.ibex.plat.X11$X11Picture");
bcp.loadAllMethods("org.ibex.Surface");
- bcp.loadAllMethods("org.ibex.Template$TemplateHelper$1");
- bcp.loadAllMethods("org.ibex.Surface$DoubleBufferedSurface");
- bcp.loadAllMethods("org.ibex.Surface$3");
- bcp.loadAllMethods("org.ibex.Surface$2");
bcp.loadAllMethods("org.ibex.Picture");
bcp.loadAllMethods("org.ibex.PixelBuffer");
- bcp.loadAllMethods("org.ibex.Platform");
- bcp.loadAllMethods("org.ibex.Scheduler");
- bcp.loadAllMethods("org.ibex.plat.X11");
- bcp.loadAllMethods("org.ibex.plat.X11$X11Picture");
- bcp.loadAllMethods("org.ibex.plat.X11$X11PixelBuffer");
- bcp.loadAllMethods("org.ibex.plat.X11$X11Surface");
- bcp.loadAllMethods("org.ibex.XMLRPC");
-
- bcp.loadAllMethods("java.util.Date");
- bcp.loadAllMethods("java.text.DateFormat");
- bcp.loadAllMethods("java.text.NumberFormat");
-
- 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]);
- }
+ // primary entry point
+ bcp.loadMethod("org.ibex.plat.Linux.main");
System.out.println();
System.out.println("Dumping...");
-
StringTokenizer st = new StringTokenizer(s[0], ":");
while(st.hasMoreTokens()) {
ZipFile zf = new ZipFile(st.nextToken());
}
}
- 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());
cg.setMajor(46);
cg.setMinor(0);
cg.setConstantPool(newcpg);
- 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++;
-
- // superprune: URLClassLoader, convert.In/Output other than needed, unneeded locales
- // reflective metadata is killing us...
-
+
+ boolean constructed = false;
Method[] methods = getMethods(clazz);
+ for(int i=0; i<methods.length; i++)
+ if (dest.contains(methods[i]) && methods[i].getName().equals("<init>"))
+ constructed = true;
+
+ // 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();
+ for(int i=0; i<fields.length; i++) {
+ if (!dest.contains(fields[i]) && fields[i].isStatic()) {
+ System.out.println(" pruning field " + clazz.getClassName() + "." + fields[i].getName());
+ cg.removeField(fields[i]);
+ }
+ /* -- there's really no point to this --
+ if (!constructed && !fields[i].isStatic()) {
+ System.out.println(" unconstructed: pruning field " + clazz.getClassName() + "." + fields[i].getName());
+ cg.removeField(fields[i]);
+ }
+ */
+ }
+
int numMethods = 0;
boolean good = false;
- for(int i=0; i<methods.length; i++)
- if (clazz.getClassName().startsWith("gnu.gcj.runtime.")
- || clazz.getClassName().startsWith("java.io.FileDescriptor")
- || clazz.getClassName().startsWith("org.ibex.")
- || clazz.getClassName().startsWith("java.lang.")) {
- good = true;
- } else if (dest.contains(methods[i])) {
+ for(int i=0; i<methods.length; i++) {
+ if (dest.contains(methods[i]) && (constructed || !methods[i].isStatic())) {
if (!methods[i].getName().equals("<clinit>")) good = true;
} else {
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) {
- 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));
- il.append(InstructionConstants.ATHROW);
-
- mg.setMaxStack();
- mg.setMaxLocals();
- mg.removeExceptions();
- mg.removeLocalVariables();
- mg.removeExceptionHandlers();
- mg.removeLineNumbers();
-
- cg.replaceMethod(methods[i], mg.getMethod());
- il.dispose();
- } else {
- cg.removeMethod(methods[i]);
- }
+ System.out.println(" pruning " +(constructed?"":"unconstructed")+ " method " +
+ clazz.getClassName() + "." + methods[i].getName());
+ // FIXME: try deleteMethods
+ 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));
+ 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"))
- ||
- ((clazz.getClassName().startsWith("gnu.gcj.convert.Input_") ||
- clazz.getClassName().startsWith("gnu.gcj.convert.Output_")) &&
- !(clazz.getClassName().endsWith("ASCII") ||
- clazz.getClassName().endsWith("UTF8") ||
- clazz.getClassName().endsWith("iconv") ||
- clazz.getClassName().endsWith("8859_1")))
- ||
- (!good &&
- !clazz.isInterface() &&
- !clazz.isAbstract() &&
- !clazz.getClassName().startsWith("java.io.") &&
- !clazz.getClassName().startsWith("java.lang.") &&
- !clazz.getClassName().startsWith("gnu.") &&
- !clazz.getClassName().endsWith("Error") &&
- !clazz.getClassName().endsWith("Exception") &&
- !clazz.getClassName().endsWith("Permission"))) {
-
- //System.out.println("DROPPING " + clazz.getClassName());
- //return;
+ }
+
+ if (!good) {
+ System.out.println("DROPPING " + clazz.getClassName());
+ JavaClass[] ifaces = clazz.getInterfaces();
+ String[] ifacestrings = new String[ifaces.length];
+ for(int i=0; i<ifaces.length; i++) ifacestrings[i] = ifaces[i].getClassName();
+ cg = new ClassGen(clazz.getClassName(),
+ clazz.getSuperClass().getClassName(),
+ clazz.getFileName(),
+ clazz.getAccessFlags(),
+ ifacestrings,
+ newcpg);
+ } else {
+ System.out.println("dumping " + clazz.getClassName());
}
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, ConstantPoolGen cpg) throws Exception {
- return m.getName() + m.getSignature();
- }
-
+ public String getMethodSignature(Method m, ConstantPoolGen cpg) throws Exception { return m.getName() + m.getSignature(); }
public String getMethodSignature(InvokeInstruction ii, ConstantPoolGen cpg) throws Exception {
String sig = "";
Type[] argtypes = ii.getArgumentTypes(cpg);
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().equals("java.net.URLClassLoader")) return;
if (jc.getClassName().indexOf("SharedLib") != -1) return;
if (jc.getClassName().indexOf("Datagram") != -1) return;
+
+ // gcj bug; gcj can't compile this method from a .class file input; I have no idea why
+ if (jc.getClassName().equals("java.lang.System") && method.getName().equals("runFinalizersOnExit")) return;
+
if (dest.contains(method)) return;
dest.add(method);
+
+ if (method.isStatic()) loadMethod(jc.getClassName() + ".<clinit>");
+
level += 2;
for(int i=0; i<level; i++) System.out.print(" ");
ConstantPoolGen cpg = new ConstantPoolGen(method.getConstantPool());
Instruction[] instructions = il.getInstructions();
for(int i=0; i<instructions.length; i++){
Instruction instr = instructions[i];
- if (instr instanceof LoadClass) load(((LoadClass)instr).getLoadClassType(cpg));
+ if (instr instanceof LoadClass) {
+ ObjectType ot = (ObjectType)((LoadClass)instr).getLoadClassType(cpg);
+ if (ot != null) loadMethod(ot.getClassName() + ".<clinit>");
+ }
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 = getMethods(c);
boolean good = false;
}
}
level -= 2;
- load(method.getReturnType());
+
+ // FIXME: move this to the top
Type[] argtypes = method.getArgumentTypes();
for(int i=0; i<argtypes.length; i++) load(argtypes[i]);
if (method.getExceptionTable() != null) {
}
public void visitJavaField(Field field) throws Exception {
- if (dest.contains(field)) return;
- dest.add(field);
- load(field.getType());
+ if (!dest.contains(field)) dest.add(field);
}
public void visitJavaClass(JavaClass clazz) throws Exception {
- /*
- if (clazz.getClassName().startsWith("java.security.") &&
- !clazz.getClassName().equals("java.security.cert.Certificate")) return;
- */
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);
}
+ JavaClass[] interfaces = clazz.getAllInterfaces();
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);
}
Field[] fields = clazz.getFields();
+ for(int i=0; i<fields.length; i++) {
+ if (!fields[i].isStatic()) visitJavaField(fields[i]);
+ else {
+ Type t = fields[i].getType();
+ if (t instanceof ObjectType) load(t);
+ }
+ }
+
Method[] methods = getMethods(clazz);
- for(int i=0; i<fields.length; i++) visitJavaField(fields[i]);
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("<clinit>")) visitJavaMethod(clazz, methods[i]);
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]);
Object[] subclasses = s.toArray();
for(int i=0; i<subclasses.length; i++) {
JavaClass subclass = (JavaClass)subclasses[i];
- for(int j=0; j<level; j++) System.out.print(" ");
- System.out.println(" [subclass " + subclass.getClassName() + "]");
- if (subclass == c) return;
+ if (subclass == c) continue;
markMethodInSubclasses(c, m, subclass, cpg);
}
}