better
[org.ibex.core.git] / src / org / ibex / util / BytecodePruner.java
index 9dbae75..f9a3b64 100644 (file)
@@ -7,76 +7,111 @@ import org.apache.bcel.generic.*;
 import org.apache.bcel.classfile.*;
 import org.apache.bcel.util.*;
 
-        // SecurityManager hacks to avoid java.security?
-        // URL and all descendents?  Probably impossible.
-        // ObjectInput/ObjectOutput?  Serialization?
-
-        // superprune: URLClassLoader, convert.In/Output other than needed, unneeded locales
-        // reflective metadata is killing us...
-
-// 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)
-
+// Field pruning
 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 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++)
             if (meths[i].getName().equals(methodname))
                 visitJavaMethod(repo.loadClass(classname), meths[i]);
     }
-
     public static void main(String[] s) throws Exception {
-        BytecodePruner bcp = new BytecodePruner();
         int start = 1;
         if (s.length >= 3 && s[1].equals("-o")) { outdir = s[2]; start += 2; }
         repo = SyntheticRepository.getInstance(new ClassPath(s[0]));
-        for(int i=start; i<s.length; i++)
-            if (s[i].endsWith(".class")) bcp.visitJavaClass(repo.loadClass(s[i].substring(0, s[i].length() - 6)));
-            else bcp.loadMethod(s[i]);
 
-        bcp.loadMethod("java.lang.Thread.run");                                // we call start(), but the VM calls run()...
-        bcp.loadAllMethods("gnu.gcj.runtime.StringBuffer");                    // the compiler emits calls directly to this class
+        BytecodePruner bcp = new BytecodePruner();
+        for(int i=start; i<s.length; i++) {
+            try {
+                if (s[i].endsWith(".class")) {
+                    bcp.visitJavaClass(repo.loadClass(s[i].substring(0, s[i].length() - 6)));
+                } 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]);
+                    }
+                }
+            } catch (Exception e) {
+                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.visitJavaClass(repo.loadClass("java.awt.AWTPermission"));
-        bcp.visitJavaClass(repo.loadClass("gnu.classpath.Configuration"));
+
         bcp.loadAllMethods("java.util.Hashtable$HashIterator");
         bcp.loadMethod("java.util.SimpleTimeZone.useDaylightTime");
         bcp.visitJavaClass(repo.loadClass("gnu.gcj.runtime.FinalizerThread"));
         bcp.visitJavaClass(repo.loadClass("gnu.gcj.runtime.FirstThread"));
 
-        StringTokenizer st = new StringTokenizer(s[0], ":"); 
+        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 = 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], ":");
         while(st.hasMoreTokens()) {
             ZipFile zf = new ZipFile(st.nextToken());
             Enumeration e = zf.entries();
@@ -93,88 +128,61 @@ public class BytecodePruner {
     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.setConstantPool(newcpg);
         InstructionFactory factory = new InstructionFactory(cg, newcpg);
         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]);
+            }
 
         Method[] methods = getMethods(clazz);
         int numMethods = 0;
         boolean good = false;
-        for(int i=0; i<methods.length; i++)
-            if (clazz.getClassName().startsWith("java.io.FileDescriptor")) {
-                good = true;
-            } else if (dest.contains(methods[i])) {
+        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.")
+                ) {
                 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]);
-                    }
+                    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;
         }
+                               
         new File(outdir + "/" + new File(clazz.getClassName().replace('.', '/')).getParent()).mkdirs();
         System.out.println("dumping " + clazz.getClassName());
         cg.getJavaClass().dump(outdir + "/" + clazz.getClassName().replace('.', '/') + ".class");
@@ -204,7 +212,6 @@ public class BytecodePruner {
     }
     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());
@@ -227,16 +234,24 @@ public class BytecodePruner {
     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;
         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(" ");
-        ConstantPool cp = method.getConstantPool();
-        ConstantPoolGen cpg = new ConstantPoolGen(cp);
+        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; }
@@ -247,6 +262,24 @@ public class BytecodePruner {
             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);
@@ -273,15 +306,6 @@ public class BytecodePruner {
             String[] exntypes = method.getExceptionTable().getExceptionNames();
             for(int i=0; i<exntypes.length; i++) load(exntypes[i]);
         }
-        if (method.getCode() != null && method.getCode().getExceptionTable() != null) {
-            CodeException[] exntypes = method.getCode().getExceptionTable();
-
-            for(int i=0; i<exntypes.length; i++) {
-                int index = exntypes[i].getCatchType();
-                if (index == 0) continue;
-                load(Utility.compactClassName(cp.getConstantString(index, Constants.CONSTANT_Class), false));
-            }
-        }
     }
 
     public void visitJavaField(Field field) throws Exception {
@@ -291,10 +315,6 @@ public class BytecodePruner {
     }
 
     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);
 
@@ -303,38 +323,37 @@ public class BytecodePruner {
         System.out.println(clazz.getClassName() + ".class");
 
         JavaClass superclass = clazz.getSuperClass();
-        for(JavaClass sup = clazz; sup != null; sup = sup.getSuperClass()) {
-            if (sup != clazz) {
-                if (subclasses.get(sup) == null) subclasses.put(sup, new HashSet());
-                ((HashSet)subclasses.get(sup)).add(clazz);
-            }
-            JavaClass[] interfaces = sup.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);
-            }
+        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());
+        if (clazz.getClassName().startsWith("org.ibex."))
+            loadAllMethods(clazz.getClassName());
 
-        for(JavaClass sup = clazz; sup != null; sup = sup.getSuperClass()) {
-            if (sup != clazz) {
-                visitJavaClass(sup);
-                remarkMethods(sup, clazz, cpg);
-            }
-            JavaClass[] interfaces = sup.getAllInterfaces();
-            for(int i=0; i<interfaces.length; i++) {
-                visitJavaClass(interfaces[i]);
-                remarkMethods(interfaces[i], clazz, cpg);
-            }
+        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();
+        for(int i=0; i<fields.length; i++) {
+            if (!fields[i].isStatic())
+                visitJavaField(fields[i]);
+        }
+
         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("equals")) visitJavaMethod(clazz, methods[i]);
             if (methods[i].getName().equals("hashCode")) visitJavaMethod(clazz, methods[i]);
@@ -349,8 +368,7 @@ public class BytecodePruner {
         String sig = getMethodSignature(m, cpg);
         Method[] submethods = getMethods(subclass);
         for(int j=0; j<submethods.length; j++)
-            //if (getMethodSignature(submethods[j], cpg).equals(sig))
-            if (submethods[j].getName().equals(m.getName()))
+            if (getMethodSignature(submethods[j], cpg).equals(sig))
                 visitJavaMethod(subclass, submethods[j]);
     }
     public void markMethodInSubclasses(JavaClass c, Method m, ConstantPoolGen cpg) throws Exception {
@@ -360,9 +378,9 @@ public class BytecodePruner {
         Object[] subclasses = s.toArray();
         for(int i=0; i<subclasses.length; i++) {
             JavaClass subclass = (JavaClass)subclasses[i];
+            if (subclass == c) continue;
             for(int j=0; j<level; j++) System.out.print(" ");
             System.out.println("  [subclass " + subclass.getClassName() + "]");
-            if (subclass == c) return;
             markMethodInSubclasses(c, m, subclass, cpg);
         }
     }