- /*
- * Javassist, a Java-bytecode translator toolkit.
- * Copyright (C) 1999- Shigeru Chiba. All Rights Reserved.
- *
- * The contents of this file are subject to the Mozilla Public License Version
- * 1.1 (the "License"); you may not use this file except in compliance with
- * the License. Alternatively, the contents of this file may be used under
- * the terms of the GNU Lesser General Public License Version 2.1 or later,
- * or the Apache License Version 2.0.
- *
- * Software distributed under the License is distributed on an "AS IS" basis,
- * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
- * for the specific language governing rights and limitations under the
- * License.
- */
-
- package javassist.bytecode.stackmap;
-
- import java.util.ArrayList;
- import javassist.ClassPool;
- import javassist.CtClass;
- import javassist.NotFoundException;
- import javassist.bytecode.*;
-
- /**
- * Stack map maker.
- */
- public class MapMaker extends Tracer {
- /*
- public static void main(String[] args) throws Exception {
- boolean useMain2 = args[0].equals("0");
- if (useMain2 && args.length > 1) {
- main2(args);
- return;
- }
-
- for (int i = 0; i < args.length; i++)
- main1(args[i]);
- }
-
- public static void main1(String className) throws Exception {
- ClassPool cp = ClassPool.getDefault();
- //javassist.CtClass cc = cp.get(className);
- javassist.CtClass cc = cp.makeClass(new java.io.FileInputStream(className));
- System.out.println(className);
- ClassFile cf = cc.getClassFile();
- java.util.List minfos = cf.getMethods();
- for (int i = 0; i < minfos.size(); i++) {
- MethodInfo minfo = (MethodInfo)minfos.get(i);
- CodeAttribute ca = minfo.getCodeAttribute();
- if (ca != null)
- ca.setAttribute(make(cp, minfo));
- }
-
- cc.writeFile("tmp");
- }
-
- public static void main2(String[] args) throws Exception {
- ClassPool cp = ClassPool.getDefault();
- //javassist.CtClass cc = cp.get(args[1]);
- javassist.CtClass cc = cp.makeClass(new java.io.FileInputStream(args[1]));
- MethodInfo minfo;
- if (args[2].equals("_init_"))
- minfo = cc.getDeclaredConstructors()[0].getMethodInfo();
- // minfo = cc.getClassInitializer().getMethodInfo();
- else
- minfo = cc.getDeclaredMethod(args[2]).getMethodInfo();
-
- CodeAttribute ca = minfo.getCodeAttribute();
- if (ca == null) {
- System.out.println("abstarct method");
- return;
- }
-
- TypedBlock[] blocks = TypedBlock.makeBlocks(minfo, ca, false);
- MapMaker mm = new MapMaker(cp, minfo, ca);
- mm.make(blocks, ca.getCode());
- for (int i = 0; i < blocks.length; i++)
- System.out.println(blocks[i]);
- }
- */
-
- /**
- * Computes the stack map table of the given method and returns it.
- * It returns null if the given method does not have to have a
- * stack map table or it includes JSR.
- */
- public static StackMapTable make(ClassPool classes, MethodInfo minfo)
- throws BadBytecode
- {
- CodeAttribute ca = minfo.getCodeAttribute();
- if (ca == null)
- return null;
-
- TypedBlock[] blocks;
- try {
- blocks = TypedBlock.makeBlocks(minfo, ca, true);
- }
- catch (BasicBlock.JsrBytecode e) {
- return null;
- }
-
- if (blocks == null)
- return null;
-
- MapMaker mm = new MapMaker(classes, minfo, ca);
- try {
- mm.make(blocks, ca.getCode());
- }
- catch (BadBytecode bb) {
- throw new BadBytecode(minfo, bb);
- }
-
- return mm.toStackMap(blocks);
- }
-
- /**
- * Computes the stack map table for J2ME.
- * It returns null if the given method does not have to have a
- * stack map table or it includes JSR.
- */
- public static StackMap make2(ClassPool classes, MethodInfo minfo)
- throws BadBytecode
- {
- CodeAttribute ca = minfo.getCodeAttribute();
- if (ca == null)
- return null;
-
- TypedBlock[] blocks;
- try {
- blocks = TypedBlock.makeBlocks(minfo, ca, true);
- }
- catch (BasicBlock.JsrBytecode e) {
- return null;
- }
-
- if (blocks == null)
- return null;
-
- MapMaker mm = new MapMaker(classes, minfo, ca);
- try {
- mm.make(blocks, ca.getCode());
- }
- catch (BadBytecode bb) {
- throw new BadBytecode(minfo, bb);
- }
- return mm.toStackMap2(minfo.getConstPool(), blocks);
- }
-
- public MapMaker(ClassPool classes, MethodInfo minfo, CodeAttribute ca) {
- super(classes, minfo.getConstPool(),
- ca.getMaxStack(), ca.getMaxLocals(),
- TypedBlock.getRetType(minfo.getDescriptor()));
- }
-
- protected MapMaker(MapMaker old) { super(old); }
-
- /**
- * Runs an analyzer (Phase 1 and 2).
- */
- void make(TypedBlock[] blocks, byte[] code)
- throws BadBytecode
- {
- make(code, blocks[0]);
- try {
- fixTypes(code, blocks);
- } catch (NotFoundException e) {
- throw new BadBytecode("failed to resolve types", e);
- }
- }
-
- // Phase 1
-
- private void make(byte[] code, TypedBlock tb)
- throws BadBytecode
- {
- copyTypeData(tb.stackTop, tb.stackTypes, stackTypes);
- stackTop = tb.stackTop;
- copyTypeData(tb.localsTypes.length, tb.localsTypes, localsTypes);
-
- traceException(code, tb.toCatch);
-
- int pos = tb.position;
- int end = pos + tb.length;
- while (pos < end)
- pos += doOpcode(pos, code);
-
- traceException(code, tb.toCatch);
-
- if (tb.exit != null) {
- for (int i = 0; i < tb.exit.length; i++) {
- TypedBlock e = (TypedBlock)tb.exit[i];
- if (e.alreadySet())
- mergeMap(e, true);
- else {
- recordStackMap(e);
- MapMaker maker = new MapMaker(this);
- maker.make(code, e);
- }
- }
- }
- }
-
- private void traceException(byte[] code, TypedBlock.Catch handler)
- throws BadBytecode
- {
- while (handler != null) {
- TypedBlock tb = (TypedBlock)handler.body;
- if (tb.alreadySet()) {
- mergeMap(tb, false);
- if (tb.stackTop < 1)
- throw new BadBytecode("bad catch clause: " + handler.typeIndex);
-
- tb.stackTypes[0] = merge(toExceptionType(handler.typeIndex),
- tb.stackTypes[0]);
- }
- else {
- recordStackMap(tb, handler.typeIndex);
- MapMaker maker = new MapMaker(this);
- maker.make(code, tb);
- }
-
- handler = handler.next;
- }
- }
-
- private void mergeMap(TypedBlock dest, boolean mergeStack) throws BadBytecode {
- int n = localsTypes.length;
- for (int i = 0; i < n; i++)
- dest.localsTypes[i] = merge(localsTypes[i], dest.localsTypes[i]);
-
- if (mergeStack) {
- n = stackTop;
- for (int i = 0; i < n; i++)
- dest.stackTypes[i] = merge(stackTypes[i], dest.stackTypes[i]);
- }
- }
-
- private TypeData merge(TypeData src, TypeData target) throws BadBytecode {
- if (src == target)
- return target;
- else if (target instanceof TypeData.ClassName
- || target instanceof TypeData.BasicType) // a parameter
- return target;
- else if (target instanceof TypeData.AbsTypeVar) {
- ((TypeData.AbsTypeVar)target).merge(src);
- return target;
- }
- else
- throw new RuntimeException("fatal: this should never happen");
- }
-
- private void recordStackMap(TypedBlock target)
- throws BadBytecode
- {
- TypeData[] tStackTypes = TypeData.make(stackTypes.length);
- int st = stackTop;
- recordTypeData(st, stackTypes, tStackTypes);
- recordStackMap0(target, st, tStackTypes);
- }
-
- private void recordStackMap(TypedBlock target, int exceptionType)
- throws BadBytecode
- {
- TypeData[] tStackTypes = TypeData.make(stackTypes.length);
- tStackTypes[0] = toExceptionType(exceptionType).join();
- recordStackMap0(target, 1, tStackTypes);
- }
-
- private TypeData.ClassName toExceptionType(int exceptionType) {
- String type;
- if (exceptionType == 0) // for finally clauses
- type= "java.lang.Throwable";
- else
- type = cpool.getClassInfo(exceptionType);
-
- return new TypeData.ClassName(type);
- }
-
- private void recordStackMap0(TypedBlock target, int st, TypeData[] tStackTypes)
- throws BadBytecode
- {
- int n = localsTypes.length;
- TypeData[] tLocalsTypes = TypeData.make(n);
- int k = recordTypeData(n, localsTypes, tLocalsTypes);
- target.setStackMap(st, tStackTypes, k, tLocalsTypes);
- }
-
- protected static int recordTypeData(int n, TypeData[] srcTypes, TypeData[] destTypes) {
- int k = -1;
- for (int i = 0; i < n; i++) {
- TypeData t = srcTypes[i];
- destTypes[i] = t.join();
- if (t != TOP)
- k = i + 1; // t might be long or double.
- }
-
- return k + 1;
- }
-
- protected static void copyTypeData(int n, TypeData[] srcTypes, TypeData[] destTypes) {
- for (int i = 0; i < n; i++)
- destTypes[i] = srcTypes[i];
- }
-
- // Phase 2
-
- /*
- * This method first finds strongly connected components (SCCs)
- * on a graph made by TypeData by Tarjan's algorithm.
- * SCCs are TypeData nodes sharing the same type.
- * Since SCCs are found in the topologically sorted order,
- * their types are also fixed when they are found.
- */
- private void fixTypes(byte[] code, TypedBlock[] blocks) throws NotFoundException, BadBytecode {
- ArrayList preOrder = new ArrayList();
- int len = blocks.length;
- int index = 0;
- for (int i = 0; i < len; i++) {
- TypedBlock block = blocks[i];
- if (block.localsTypes == null) // if block is dead code
- fixDeadcode(code, block);
- else {
- int n = block.localsTypes.length;
- for (int j = 0; j < n; j++)
- index = block.localsTypes[j].dfs(preOrder, index, classPool);
-
- n = block.stackTop;
- for (int j = 0; j < n; j++)
- index = block.stackTypes[j].dfs(preOrder, index, classPool);
- }
- }
- }
-
- private void fixDeadcode(byte[] code, TypedBlock block) throws BadBytecode {
- int pos = block.position;
- int len = block.length - 3;
- if (len < 0)
- throw new BadBytecode("dead code detected at " + pos
- + ". No stackmap table generated.");
-
- for (int k = 0; k < len; k++)
- code[pos + k] = Bytecode.NOP;
-
- code[pos + len] = (byte)Bytecode.GOTO;
- ByteArray.write16bit(-len, code, pos + len + 1);
- }
-
- // Phase 3
-
- public StackMapTable toStackMap(TypedBlock[] blocks) {
- StackMapTable.Writer writer = new StackMapTable.Writer(32);
- int n = blocks.length;
- TypedBlock prev = blocks[0];
- int offsetDelta = prev.length;
- if (prev.incoming > 0) { // the first instruction is a branch target.
- writer.sameFrame(0);
- offsetDelta--;
- }
-
- for (int i = 1; i < n; i++) {
- TypedBlock bb = blocks[i];
- if (isTarget(bb, blocks[i - 1])) {
- bb.resetNumLocals();
- int diffL = stackMapDiff(prev.numLocals, prev.localsTypes,
- bb.numLocals, bb.localsTypes);
- toStackMapBody(writer, bb, diffL, offsetDelta, prev);
- offsetDelta = bb.length - 1;
- prev = bb;
- }
- else if (bb.incoming == 0) {
- // dead code.
- writer.sameFrame(offsetDelta);
- offsetDelta = bb.length - 1;
- prev = bb;
- }
- else
- offsetDelta += bb.length;
- }
-
- return writer.toStackMapTable(cpool);
- }
-
- /**
- * Returns true if cur is a branch target.
- */
- private boolean isTarget(TypedBlock cur, TypedBlock prev) {
- int in = cur.incoming;
- if (in > 1)
- return true;
- else if (in < 1)
- return false;
-
- return prev.stop;
- }
-
- private void toStackMapBody(StackMapTable.Writer writer, TypedBlock bb,
- int diffL, int offsetDelta, TypedBlock prev) {
- // if diffL is -100, two TypeData arrays do not share
- // any elements.
-
- int stackTop = bb.stackTop;
- if (stackTop == 0) {
- if (diffL == 0) {
- writer.sameFrame(offsetDelta);
- return;
- }
- else if (0 > diffL && diffL >= -3) {
- writer.chopFrame(offsetDelta, -diffL);
- return;
- }
- else if (0 < diffL && diffL <= 3) {
- int[] data = new int[diffL];
- int[] tags = fillStackMap(bb.numLocals - prev.numLocals,
- prev.numLocals, data,
- bb.localsTypes);
- writer.appendFrame(offsetDelta, tags, data);
- return;
- }
- }
- else if (stackTop == 1 && diffL == 0) {
- TypeData td = bb.stackTypes[0];
- writer.sameLocals(offsetDelta, td.getTypeTag(), td.getTypeData(cpool));
- return;
- }
- else if (stackTop == 2 && diffL == 0) {
- TypeData td = bb.stackTypes[0];
- if (td.is2WordType()) {
- // bb.stackTypes[1] must be TOP.
- writer.sameLocals(offsetDelta, td.getTypeTag(), td.getTypeData(cpool));
- return;
- }
- }
-
- int[] sdata = new int[stackTop];
- int[] stags = fillStackMap(stackTop, 0, sdata, bb.stackTypes);
- int[] ldata = new int[bb.numLocals];
- int[] ltags = fillStackMap(bb.numLocals, 0, ldata, bb.localsTypes);
- writer.fullFrame(offsetDelta, ltags, ldata, stags, sdata);
- }
-
- private int[] fillStackMap(int num, int offset, int[] data, TypeData[] types) {
- int realNum = diffSize(types, offset, offset + num);
- ConstPool cp = cpool;
- int[] tags = new int[realNum];
- int j = 0;
- for (int i = 0; i < num; i++) {
- TypeData td = types[offset + i];
- tags[j] = td.getTypeTag();
- data[j] = td.getTypeData(cp);
- if (td.is2WordType())
- i++;
-
- j++;
- }
-
- return tags;
- }
-
- private static int stackMapDiff(int oldTdLen, TypeData[] oldTd,
- int newTdLen, TypeData[] newTd)
- {
- int diff = newTdLen - oldTdLen;
- int len;
- if (diff > 0)
- len = oldTdLen;
- else
- len = newTdLen;
-
- if (stackMapEq(oldTd, newTd, len))
- if (diff > 0)
- return diffSize(newTd, len, newTdLen);
- else
- return -diffSize(oldTd, len, oldTdLen);
- else
- return -100;
- }
-
- private static boolean stackMapEq(TypeData[] oldTd, TypeData[] newTd, int len) {
- for (int i = 0; i < len; i++) {
- if (!oldTd[i].eq(newTd[i]))
- return false;
- }
-
- return true;
- }
-
- private static int diffSize(TypeData[] types, int offset, int len) {
- int num = 0;
- while (offset < len) {
- TypeData td = types[offset++];
- num++;
- if (td.is2WordType())
- offset++;
- }
-
- return num;
- }
-
- // Phase 3 for J2ME
-
- public StackMap toStackMap2(ConstPool cp, TypedBlock[] blocks) {
- StackMap.Writer writer = new StackMap.Writer();
- int n = blocks.length; // should be > 0
- boolean[] effective = new boolean[n];
- TypedBlock prev = blocks[0];
-
- // Is the first instruction a branch target?
- effective[0] = prev.incoming > 0;
-
- int num = effective[0] ? 1 : 0;
- for (int i = 1; i < n; i++) {
- TypedBlock bb = blocks[i];
- if (effective[i] = isTarget(bb, blocks[i - 1])) {
- bb.resetNumLocals();
- prev = bb;
- num++;
- }
- }
-
- if (num == 0)
- return null;
-
- writer.write16bit(num);
- for (int i = 0; i < n; i++)
- if (effective[i])
- writeStackFrame(writer, cp, blocks[i].position, blocks[i]);
-
- return writer.toStackMap(cp);
- }
-
- private void writeStackFrame(StackMap.Writer writer, ConstPool cp, int offset, TypedBlock tb) {
- writer.write16bit(offset);
- writeVerifyTypeInfo(writer, cp, tb.localsTypes, tb.numLocals);
- writeVerifyTypeInfo(writer, cp, tb.stackTypes, tb.stackTop);
- }
-
- private void writeVerifyTypeInfo(StackMap.Writer writer, ConstPool cp, TypeData[] types, int num) {
- int numDWord = 0;
- for (int i = 0; i < num; i++) {
- TypeData td = types[i];
- if (td != null && td.is2WordType()) {
- numDWord++;
- i++;
- }
- }
-
- writer.write16bit(num - numDWord);
- for (int i = 0; i < num; i++) {
- TypeData td = types[i];
- writer.writeVerifyTypeInfo(td.getTypeTag(), td.getTypeData(cp));
- if (td.is2WordType())
- i++;
- }
- }
- }
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