--- /dev/null
+// Copyright (C) 2004 Brian Alliet
+
+// Based on NanoGoat by Adam Megac
+
+// Copyright (C) 2004 Adam Megacz <adam@ibex.org> all rights reserved.
+//
+// You may modify, copy, and redistribute this code under the terms of
+// the GNU Library Public License version 2.1, with the exception of
+// the portion of clause 6a after the semicolon (aka the "obnoxious
+// relink clause")
+
+package com.brian_web.gcclass;
+
+import java.util.*;
+import java.io.*;
+
+import org.apache.bcel.Constants;
+import org.apache.bcel.util.*;
+import org.apache.bcel.generic.*;
+import org.apache.bcel.classfile.*;
+
+// FEATURE: Rebuild each method with a new constant pool to eliminate extra constant pool entries
+// FEATURE: Optimize away INSTANCEOF if the class can never be instansiated
+
+public class GCClass {
+ // This is called outside pure java so we don't see the call
+ private static final String[] PRE_REF = { "java.lang.Thread.run" };
+ // The JDK uses some voodoo under the hood to implement these methods
+ private static final String[] IGNORED_METHODS = {
+ "java.net.SocketImpl.setOption(ILjava/lang/Object;)V",
+ "java.net.SocketImpl.getOption(I)Ljava/lang/Object;",
+ "java.awt.geom.*",
+ "apple.awt.*"
+ };
+
+ private static final String[] NO_OUTPUT = { "java", "javax", "sun", "com.sun", "apple", "com.apple" };
+
+
+ public static void main(String[] args) throws Exception {
+ if(args.length < 3) {
+ System.err.println("Usage GCClass classpath outdir entrypoint1 ... [ entrypoint n]");
+ System.exit(1);
+ }
+ GCClass gc = new GCClass(args[0]);
+ for(int i=2;i<args.length;i++) gc.referenceMethod(args[i]);
+ gc.go();
+ gc.dump(new File(args[1]));
+ }
+
+ private final Repository repo;
+ private final Vector work = new Vector();
+ private final Hashtable completed = new Hashtable();
+ private final Hashtable references = new Hashtable();
+
+ public GCClass(String classpath) throws ClassNotFoundException {
+ System.err.println(ClassPath.SYSTEM_CLASS_PATH + File.pathSeparator + classpath);
+ repo = SyntheticRepository.getInstance(new ClassPath(ClassPath.SYSTEM_CLASS_PATH + File.pathSeparator + classpath));
+ for(int i=0;i<PRE_REF.length;i++) referenceMethod(PRE_REF[i]);
+ }
+
+ private Hashtable classRefHash(JavaClass c) { return classRefHash(new ObjectType(c.getClassName())); }
+ private Hashtable classRefHash(ObjectType c) {
+ Hashtable h = (Hashtable) references.get(c);
+ if(h == null) references.put(c,h=new Hashtable());
+ return h;
+ }
+
+ public final ObjectType referenceClass(JavaClass c) { return referenceClass(c.getClassName()); }
+ public final ObjectType referenceClass(String s) { return referenceClass(new ObjectType(s)); }
+ public final ObjectType referenceClass(Type t) {
+ if(t instanceof ObjectType) return referenceClass((ObjectType)t);
+ return null;
+ }
+
+ public final ObjectType referenceClass(ObjectType t) {
+ classRefHash(t);
+ return t;
+ }
+
+ public final void referenceMethod(String s) throws ClassNotFoundException {
+ int p = s.lastIndexOf('.');
+ if(p == -1) throw new IllegalArgumentException("invalid class/method string");
+ String cs = s.substring(0,p);
+ String ms = s.substring(p+1);
+
+ JavaClass c = repoGet(cs);
+ Method[] methods = c.getMethods();
+ for(int i=0;i<methods.length;i++)
+ if(methods[i].getName().equals(ms))
+ referenceMethod(new MethodRef(c,methods[i]));
+ }
+
+ public final void referenceMethod(MethodRef m) {
+ if(completed.get(m) != null) return;
+
+ if(m.c.getClassName().startsWith("[")) {
+ completed.put(m,Boolean.TRUE);
+ return;
+ }
+
+ Hashtable h = classRefHash(m.c);
+ h.put(m,Boolean.TRUE);
+ work.add(m);
+
+ referenceClass(m.ret);
+ for(int i=0;i<m.args.length;i++) referenceClass(m.args[i]);
+ }
+
+ public final void referenceField(FieldRef f) {
+ Hashtable h = classRefHash(f.c);
+ h.put(f,Boolean.TRUE);
+ referenceClass(f.ftype);
+ }
+
+ private Hashtable repoCache = new Hashtable();
+ public JavaClass repoGet(ObjectType t) throws ClassNotFoundException { return repoGet(t.getClassName()); }
+ public JavaClass repoGet(String s) throws ClassNotFoundException {
+ Object o = repoCache.get(s);
+ if(o == null) repoCache.put(s,o = repo.loadClass(s));
+ return (JavaClass) o;
+ }
+
+ public void go() throws Exn, ClassNotFoundException {
+ while(work.size() != 0) {
+ while(work.size() != 0) process((MethodRef) work.remove(work.size()-1));
+ fixup();
+ }
+ }
+
+ private void fixup() throws ClassNotFoundException {
+ for(Enumeration e = references.keys(); e.hasMoreElements(); ) {
+ ObjectType t = (ObjectType) e.nextElement();
+ JavaClass c = repoGet(t);
+ if(c == null) continue;
+ Hashtable refs = (Hashtable) references.get(t);
+ if(refs.size() != 0) {
+ MethodRef clinit = new MethodRef(t,"<clinit>",Type.VOID,Type.NO_ARGS);
+ if(findMethod(c,clinit) != null) referenceMethod(clinit);
+ }
+ Method[] methods = c.getMethods();
+ JavaClass[] supers = c.getSuperClasses();
+ JavaClass[] interfaces = c.getInterfaces();
+ //System.err.println("Fixing up " + t);
+ for(int i=0;i<supers.length;i++) referenceClass(supers[i]);
+ for(int i=0;methods != null && i<methods.length;i++) {
+ MethodRef mr = new MethodRef(c,methods[i]);
+ if(refs.get(mr) != null) continue;
+ for(int j=0;j<supers.length;j++) {
+ MethodRef smr = new MethodRef(supers[j],methods[i]);
+ Hashtable srefs = classRefHash(supers[j]);
+ if(srefs.get(smr) != null) referenceMethod(mr);
+
+ JavaClass[] interfaces2 = supers[j].getInterfaces();
+ for(int k=0;interfaces2 != null && k<interfaces2.length;k++) {
+ MethodRef imr = new MethodRef(interfaces2[k],methods[i]);
+ Hashtable irefs = classRefHash(interfaces2[k]);
+ if(irefs.get(imr) != null) referenceMethod(mr);
+ }
+ }
+ for(int j=0;interfaces != null && j<interfaces.length;j++) {
+ MethodRef imr = new MethodRef(interfaces[j],methods[i]);
+ Hashtable irefs = classRefHash(interfaces[j]);
+ if(irefs.get(imr) != null) referenceMethod(mr);
+ }
+ }
+ }
+ }
+
+ private Hashtable cpgCache = new Hashtable();
+ private void process(MethodRef mr) throws Exn, ClassNotFoundException {
+ if(completed.get(mr) != null) return;
+ completed.put(mr,Boolean.TRUE);
+
+ //System.err.println("Processing " + mr + "...");
+
+ JavaClass c = repoGet(mr.c.toString());
+
+ if(!c.isClass() && !mr.name.equals("<clinit>")) return;
+
+ Method m = findMethod(c,mr);
+ if(m == null) {
+ JavaClass supers[] = c.getSuperClasses();
+ for(int i=0;i<supers.length;i++) {
+ m = findMethod(supers[i],mr);
+ if(m != null) { referenceMethod(new MethodRef(supers[i],m)); return; }
+ }
+ String sig = mr.toString();
+ for(int i=0;i<IGNORED_METHODS.length;i++) {
+ String pat = IGNORED_METHODS[i];
+ if(pat.endsWith("*") ? sig.startsWith(pat.substring(0,pat.length()-1)) : sig.equals(pat)) return;
+ }
+ throw new Exn("Couldn't find " + sig);
+ }
+
+ Code code = m.getCode();
+ if(code == null) return;
+
+ ConstantPoolGen cpg = (ConstantPoolGen) cpgCache.get(c);
+ if(cpg == null) cpgCache.put(c,cpg=new ConstantPoolGen(c.getConstantPool()));
+
+ InstructionList insnList = new InstructionList(code.getCode());
+ Instruction[] insns = insnList.getInstructions();
+
+ for(int n=0;n<insns.length;n++) {
+ Instruction i = insns[n];
+ if(i instanceof ANEWARRAY || i instanceof CHECKCAST || i instanceof INSTANCEOF || i instanceof MULTIANEWARRAY || i instanceof NEW)
+ referenceClass(((CPInstruction)i).getType(cpg));
+ else if(i instanceof FieldInstruction) // GETFIED, GETSTATIC, PUTFIELD, PUTSTATIC
+ referenceField(new FieldRef((FieldInstruction)i,cpg));
+ else if(i instanceof InvokeInstruction) // INVOKESTATIC, INVOKEVIRTUAL, INVOKESPECIAL
+ referenceMethod(new MethodRef((InvokeInstruction)i,cpg));
+ }
+ }
+
+ private static Method findMethod(JavaClass c, MethodRef mr) {
+ Method[] ms = c.getMethods();
+ for(int i=0;i<ms.length;i++) {
+ Method m = ms[i];
+ if(m.getName().equals(mr.name) && m.getReturnType().equals(mr.ret) && Arrays.equals(m.getArgumentTypes(),mr.args))
+ return m;
+ }
+ return null;
+ }
+
+ public void dump(File outdir) throws IOException, ClassNotFoundException {
+ if(!outdir.isDirectory()) throw new IOException("" + outdir + " is not a directory");
+ OUTER: for(Enumeration e = references.keys(); e.hasMoreElements(); ) {
+ ObjectType t = (ObjectType) e.nextElement();
+ String name = t.getClassName();
+ for(int i=0;i<NO_OUTPUT.length;i++) if(name.startsWith(NO_OUTPUT[i])) continue OUTER;
+ Hashtable refs = (Hashtable) references.get(t);
+ JavaClass c = repoGet(t.getClassName());
+ if(c == null) continue;
+ File cf = new File(outdir,t.getClassName().replace('.',File.separatorChar) + ".class");
+ cf.getParentFile().mkdirs();
+ dumpClass(c,refs,cf);
+ }
+ }
+
+ private void dumpClass(JavaClass c, Hashtable refs, File file) throws IOException {
+ ClassGen cg = new ClassGen(c);
+ Method[] methods= c.getMethods();
+ for(int i=0;i<methods.length;i++) {
+ Method m = methods[i];
+ MethodRef mr = new MethodRef(c,m);
+ if(refs.get(mr) == null) {
+ System.err.println("Removing method " + mr);
+ if(false) {
+ cg.removeMethod(m);
+ } else {
+ InstructionFactory fac = new InstructionFactory(cg,cg.getConstantPool());
+ InstructionList il = new InstructionList();
+ MethodGen mg = new MethodGen(m.getAccessFlags(),m.getReturnType(),m.getArgumentTypes(),null,m.getName(),c.getClassName(),il,cg.getConstantPool());
+ il.append(fac.createNew("java.lang.UnsatisfiedLinkError"));
+ il.append(InstructionConstants.DUP);
+ il.append(new PUSH(cg.getConstantPool(),"" + mr + " has been pruned"));
+ il.append(fac.createInvoke("java.lang.UnsatisfiedLinkError","<init>",Type.VOID, new Type[]{Type.STRING},Constants.INVOKESPECIAL));
+ il.append(InstructionConstants.ATHROW);
+ mg.setMaxStack();
+ mg.setMaxLocals();
+ cg.replaceMethod(m,mg.getMethod());
+ }
+ } else {
+ //System.err.println("Keeping method " + mr);
+ }
+ }
+
+ Field[] fields = c.getFields();
+ for(int i=0;i<fields.length;i++) {
+ Field f = fields[i];
+ FieldRef fr = new FieldRef(c,f);
+ if(refs.get(fr) == null) {
+ System.err.println("Removing field " + fr);
+ cg.removeField(f);
+ } else {
+ //System.err.println("Keeping field " + fr);
+ }
+ }
+
+ JavaClass n = cg.getJavaClass();
+ n.dump(file);
+ }
+
+ public static class Exn extends Exception { public Exn(String s) { super(s); } }
+
+
+ private static class MethodRef {
+ ObjectType c;
+ String name;
+ Type ret;
+ Type[] args;
+
+ public MethodRef(JavaClass c, Method m) {
+ this(new ObjectType(c.getClassName()),m.getName(),m.getReturnType(),m.getArgumentTypes());
+ }
+
+ public MethodRef(InvokeInstruction i, ConstantPoolGen cp) {
+ this(i.getClassType(cp),i.getMethodName(cp),i.getReturnType(cp),i.getArgumentTypes(cp));
+ }
+
+ public MethodRef(ObjectType c, String name, Type ret, Type[] args) {
+ this.c = c;
+ this.name = name;
+ this.ret = ret;
+ this.args = args;
+ }
+
+ public boolean equals(Object o_) {
+ if(!(o_ instanceof MethodRef)) return false;
+ MethodRef o = (MethodRef)o_;
+ boolean r = name.equals(o.name) && c.equals(o.c) && ret.equals(o.ret) && Arrays.equals(args,o.args);
+ return r;
+ }
+
+ // FIXME: ArrayType.java in BCEL doesn't properly implement hashCode()
+ public int hashCode() {
+ int hc = name.hashCode() ^ c.hashCode(); //^ ret.hashCode();
+ //for(int i=0;i<args.length;i++) hc ^= args[i].hashCode();
+ return hc;
+ }
+
+ public String toString() { return c.toString() + "." + name + Type.getMethodSignature(ret,args); }
+ }
+
+ public static class FieldRef {
+ ObjectType c;
+ String name;
+ Type ftype;
+
+ public FieldRef(JavaClass c, Field f) {
+ this(new ObjectType(c.getClassName()),f.getName(),f.getType());
+ }
+
+ public FieldRef(FieldInstruction i, ConstantPoolGen cp) {
+ this(i.getClassType(cp),i.getFieldName(cp),i.getFieldType(cp));
+ }
+ public FieldRef(ObjectType c, String name, Type ftype) { this.c = c; this.name = name; this.ftype = ftype; }
+
+ public boolean equals(Object o_) {
+ if(!(o_ instanceof FieldRef)) return false;
+ FieldRef o = (FieldRef)o_;
+ return name.equals(o.name) && c.equals(o.c);
+ }
+
+ public int hashCode() {
+ return name.hashCode() ^ c.hashCode();
+ }
+
+ public String toString() { return c.toString() + "." + name; }
+ }
+}
projects / org.ibex.gcclass.git / commitdiff