diff options
| -rw-r--r-- | bcel-builder/src/org/aspectj/apache/bcel/generic/InstructionList.java | 2339 |
1 files changed, 1192 insertions, 1147 deletions
diff --git a/bcel-builder/src/org/aspectj/apache/bcel/generic/InstructionList.java b/bcel-builder/src/org/aspectj/apache/bcel/generic/InstructionList.java index 8482e13a8..1d10fd695 100644 --- a/bcel-builder/src/org/aspectj/apache/bcel/generic/InstructionList.java +++ b/bcel-builder/src/org/aspectj/apache/bcel/generic/InstructionList.java @@ -54,1167 +54,1212 @@ package org.aspectj.apache.bcel.generic; * <http://www.apache.org/>. */ +import java.io.ByteArrayOutputStream; +import java.io.DataOutputStream; +import java.io.IOException; +import java.io.Serializable; +import java.util.ArrayList; +import java.util.HashMap; +import java.util.Iterator; +import java.util.Set; + import org.aspectj.apache.bcel.Constants; import org.aspectj.apache.bcel.classfile.Constant; import org.aspectj.apache.bcel.classfile.ConstantPool; import org.aspectj.apache.bcel.util.ByteSequence; -import java.io.*; -import java.util.Iterator; -import java.util.HashMap; -import java.util.ArrayList; -/** - * This class is a container for a list of <a - * href="Instruction.html">Instruction</a> objects. Instructions can - * be appended, inserted, moved, deleted, etc.. Instructions are being - * wrapped into <a - * href="InstructionHandle.html">InstructionHandles</a> objects that - * are returned upon append/insert operations. They give the user - * (read only) access to the list structure, such that it can be traversed and - * manipulated in a controlled way. - * - * A list is finally dumped to a byte code array with <a - * href="#getByteCode()">getByteCode</a>. - * - * @version $Id: InstructionList.java,v 1.6 2008/05/28 23:52:57 aclement Exp $ - * @author <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A> - * @see Instruction - * @see InstructionHandle +/** + * This class is a container for a list of <a href="Instruction.html">Instruction</a> objects. Instructions can be appended, + * inserted, moved, deleted, etc.. Instructions are being wrapped into <a href="InstructionHandle.html">InstructionHandles</a> + * objects that are returned upon append/insert operations. They give the user (read only) access to the list structure, such that + * it can be traversed and manipulated in a controlled way. + * + * A list is finally dumped to a byte code array with <a href="#getByteCode()">getByteCode</a>. + * + * @version $Id: InstructionList.java,v 1.7 2008/08/28 00:04:04 aclement Exp $ + * @author <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A> + * @see Instruction + * @see InstructionHandle * @see BranchHandle */ public class InstructionList implements Serializable { - private InstructionHandle start = null, end = null; - private int length = 0; // number of elements in list - private int[] byte_positions; // byte code offsets corresponding to instructions - - /** - * Create (empty) instruction list. - */ - public InstructionList() {} - - /** - * Create instruction list containing one instruction. - * @param i initial instruction - */ - public InstructionList(Instruction i) { - append(i); - } - - /** - * Create instruction list containing one instruction. - * @param i initial instruction - */ - public InstructionList(InstructionBranch i) { - append(i); - } - - - /** - * Test for empty list. - */ - public boolean isEmpty() { return start == null; } // && end == null - - public static InstructionHandle findHandle(InstructionHandle[] ihs,int[] pos,int count,int target) { - return findHandle(ihs,pos,count,target,false); - } - /** - * Find the target instruction (handle) that corresponds to the given target - * position (byte code offset). - * - * @param ihs array of instruction handles, i.e. il.getInstructionHandles() - * @param pos array of positions corresponding to ihs, i.e. il.getInstructionPositions() - * @param count length of arrays - * @param target target position to search for - * @return target position's instruction handle if available - */ - public static InstructionHandle findHandle(InstructionHandle[] ihs, - int[] pos, int count,int target,boolean returnClosestIfNoExactMatch) { - int l=0, r = count - 1; - // Do a binary search since the pos array is ordered - int i,j; - do { - i = (l + r) / 2; - j = pos[i]; - if (j == target) return ihs[i]; // found it - else if (target < j) r=i-1; // else constrain search area - else l=i+1; // target > j - } while (l <= r); - - if (returnClosestIfNoExactMatch) { - i = (l+r)/2; if (i<0) i=0; - return ihs[i]; - } - return null; - } - - /** - * Get instruction handle for instruction at byte code position pos. - * This only works properly, if the list is freshly initialized from a byte array or - * setPositions() has been called before this method. - * - * @param pos byte code position to search for - * @return target position's instruction handle if available - */ - public InstructionHandle findHandle(int pos) { - InstructionHandle[] ihs = getInstructionHandles(); - return findHandle(ihs, byte_positions, length, pos); - } - - public InstructionHandle[] getInstructionsAsArray() { - return getInstructionHandles(); - } - - public InstructionHandle findHandle(int pos,InstructionHandle[] instructionArray) { - return findHandle(instructionArray,byte_positions,length,pos); - } - - public InstructionHandle findHandle(int pos,InstructionHandle[] instructionArray,boolean useClosestApproximationIfNoExactFound) { - return findHandle(instructionArray,byte_positions,length,pos,useClosestApproximationIfNoExactFound); - } - - /** - * Initialize instruction list from byte array. - * - * @param code byte array containing the instructions - */ - public InstructionList(byte[] code) { - ByteSequence bytes = new ByteSequence(code); - InstructionHandle[] ihs = new InstructionHandle[code.length]; - int[] pos = new int[code.length]; // Can't be more than that - int count = 0; // Contains actual length - - /* Pass 1: Create an object for each byte code and append them - * to the list. - */ - try { - while(bytes.available() > 0) { - // Remember byte offset and associate it with the instruction - int off = bytes.getIndex(); - pos[count] = off; - - /* Read one instruction from the byte stream, the byte position is set - * accordingly. + private InstructionHandle start = null, end = null; + private int length = 0; // number of elements in list + private int[] byte_positions; // byte code offsets corresponding to instructions + + /** + * Create (empty) instruction list. + */ + public InstructionList() { + } + + /** + * Create instruction list containing one instruction. + * + * @param i initial instruction + */ + public InstructionList(Instruction i) { + append(i); + } + + /** + * Test for empty list. + */ + public boolean isEmpty() { + return start == null; + } // && end == null + + public static InstructionHandle findHandle(InstructionHandle[] ihs, int[] pos, int count, int target) { + return findHandle(ihs, pos, count, target, false); + } + + /** + * Find the target instruction (handle) that corresponds to the given target position (byte code offset). + * + * @param ihs array of instruction handles, i.e. il.getInstructionHandles() + * @param pos array of positions corresponding to ihs, i.e. il.getInstructionPositions() + * @param count length of arrays + * @param target target position to search for + * @return target position's instruction handle if available + */ + public static InstructionHandle findHandle(InstructionHandle[] ihs, int[] pos, int count, int target, + boolean returnClosestIfNoExactMatch) { + int l = 0, r = count - 1; + // Do a binary search since the pos array is ordered + int i, j; + do { + i = (l + r) / 2; + j = pos[i]; + if (j == target) { + return ihs[i]; // found it + } else if (target < j) { + r = i - 1; // else constrain search area + } else { + l = i + 1; // target > j + } + } while (l <= r); + + if (returnClosestIfNoExactMatch) { + i = (l + r) / 2; + if (i < 0) { + i = 0; + } + return ihs[i]; + } + return null; + } + + /** + * Get instruction handle for instruction at byte code position pos. This only works properly, if the list is freshly + * initialized from a byte array or setPositions() has been called before this method. + * + * @param pos byte code position to search for + * @return target position's instruction handle if available + */ + public InstructionHandle findHandle(int pos) { + InstructionHandle[] ihs = getInstructionHandles(); + return findHandle(ihs, byte_positions, length, pos); + } + + public InstructionHandle[] getInstructionsAsArray() { + return getInstructionHandles(); + } + + public InstructionHandle findHandle(int pos, InstructionHandle[] instructionArray) { + return findHandle(instructionArray, byte_positions, length, pos); + } + + public InstructionHandle findHandle(int pos, InstructionHandle[] instructionArray, boolean useClosestApproximationIfNoExactFound) { + return findHandle(instructionArray, byte_positions, length, pos, useClosestApproximationIfNoExactFound); + } + + /** + * Initialize instruction list from byte array. + * + * @param code byte array containing the instructions + */ + public InstructionList(byte[] code) { + ByteSequence bytes = new ByteSequence(code); + InstructionHandle[] ihs = new InstructionHandle[code.length]; + int[] pos = new int[code.length]; // Can't be more than that + int count = 0; // Contains actual length + + /* + * Pass 1: Create an object for each byte code and append them to the list. + */ + try { + while (bytes.available() > 0) { + // Remember byte offset and associate it with the instruction + int off = bytes.getIndex(); + pos[count] = off; + + /* + * Read one instruction from the byte stream, the byte position is set accordingly. + */ + Instruction i = Instruction.readInstruction(bytes); + InstructionHandle ih; + if (i instanceof InstructionBranch) { + ih = append((InstructionBranch) i); + } else { + ih = append(i); + } + + ih.setPosition(off); + ihs[count] = ih; + + count++; + } + } catch (IOException e) { + throw new ClassGenException(e.toString()); + } + + byte_positions = new int[count]; // Trim to proper size + System.arraycopy(pos, 0, byte_positions, 0, count); + + /* + * Pass 2: Look for BranchInstruction and update their targets, i.e., convert offsets to instruction handles. */ - Instruction i = Instruction.readInstruction(bytes); + // OPTIMIZE better way of doing this? keep little map from earlier from pos -> instruction handle? + for (int i = 0; i < count; i++) { + if (ihs[i] instanceof BranchHandle) { + InstructionBranch bi = (InstructionBranch) ihs[i].instruction; + int target = bi.positionOfThisInstruction + bi.getIndex(); /* + * Byte code position: relative -> absolute. + */ + // Search for target position + InstructionHandle ih = findHandle(ihs, pos, count, target); + + if (ih == null) { + throw new ClassGenException("Couldn't find target for branch: " + bi); + } + + bi.setTarget(ih); // Update target + + // If it is a Select instruction, update all branch targets + if (bi instanceof InstructionSelect) { // Either LOOKUPSWITCH or TABLESWITCH + InstructionSelect s = (InstructionSelect) bi; + int[] indices = s.getIndices(); + + for (int j = 0; j < indices.length; j++) { + target = bi.positionOfThisInstruction + indices[j]; + ih = findHandle(ihs, pos, count, target); + + if (ih == null) { + throw new ClassGenException("Couldn't find target for switch: " + bi); + } + + s.setTarget(j, ih); // Update target + } + } + } + } + } + + /** + * Append another list after instruction (handle) ih contained in this list. Consumes argument list, i.e., it becomes empty. + * + * @param ih where to append the instruction list + * @param il Instruction list to append to this one + * @return instruction handle pointing to the <B>first</B> appended instruction + */ + public InstructionHandle append(InstructionHandle ih, InstructionList il) { + if (il == null) { + throw new ClassGenException("Appending null InstructionList"); + } + + if (il.isEmpty()) { + return ih; + } + + InstructionHandle next = ih.next, ret = il.start; + + ih.next = il.start; + il.start.prev = ih; + + il.end.next = next; + + if (next != null) { + next.prev = il.end; + } else { + end = il.end; // Update end ... + } + + length += il.length; // Update length + + il.clear(); + + return ret; + } + + /** + * Append another list after instruction i contained in this list. Consumes argument list, i.e., it becomes empty. + * + * @param i where to append the instruction list + * @param il Instruction list to append to this one + * @return instruction handle pointing to the <B>first</B> appended instruction + */ + public InstructionHandle append(Instruction i, InstructionList il) { InstructionHandle ih; - if (i instanceof InstructionBranch) // Use proper append() method - ih = append((InstructionBranch)i); - else - ih = append(i); - - ih.setPosition(off); - ihs[count] = ih; - - count++; - } - } catch(IOException e) { throw new ClassGenException(e.toString()); } - - byte_positions = new int[count]; // Trim to proper size - System.arraycopy(pos, 0, byte_positions, 0, count); - - /* Pass 2: Look for BranchInstruction and update their targets, i.e., - * convert offsets to instruction handles. - */ - // OPTIMIZE better way of doing this? keep little map from earlier from pos -> instruction handle? - for(int i=0; i < count; i++) { - if(ihs[i] instanceof BranchHandle) { - InstructionBranch bi = (InstructionBranch)ihs[i].instruction; - int target = bi.positionOfThisInstruction + bi.getIndex(); /* Byte code position: - * relative -> absolute. */ - // Search for target position - InstructionHandle ih = findHandle(ihs, pos, count, target); - - if(ih == null) // Search failed - throw new ClassGenException("Couldn't find target for branch: " + bi); - - bi.setTarget(ih); // Update target - - // If it is a Select instruction, update all branch targets - if(bi instanceof InstructionSelect) { // Either LOOKUPSWITCH or TABLESWITCH - InstructionSelect s = (InstructionSelect)bi; - int[] indices = s.getIndices(); - - for(int j=0; j < indices.length; j++) { - target = bi.positionOfThisInstruction + indices[j]; - ih = findHandle(ihs, pos, count, target); - - if(ih == null) // Search failed - throw new ClassGenException("Couldn't find target for switch: " + bi); - - s.setTarget(j, ih); // Update target - } + + if ((ih = findInstruction2(i)) == null) { + throw new ClassGenException("Instruction " + i + " is not contained in this list."); + } + + return append(ih, il); + } + + /** + * Append another list to this one. Consumes argument list, i.e., it becomes empty. + * + * @param il list to append to end of this list + * @return instruction handle of the <B>first</B> appended instruction + */ + public InstructionHandle append(InstructionList il) { + if (il == null) { + throw new ClassGenException("Appending null InstructionList"); } - } - } - } - - /** - * Append another list after instruction (handle) ih contained in this list. - * Consumes argument list, i.e., it becomes empty. - * - * @param ih where to append the instruction list - * @param il Instruction list to append to this one - * @return instruction handle pointing to the <B>first</B> appended instruction - */ - public InstructionHandle append(InstructionHandle ih, InstructionList il) { - if(il == null) - throw new ClassGenException("Appending null InstructionList"); - - if(il.isEmpty()) // Nothing to do - return ih; - - InstructionHandle next = ih.next, ret = il.start; - - ih.next = il.start; - il.start.prev = ih; - - il.end.next = next; - - if(next != null) // i == end ? - next.prev = il.end; - else - end = il.end; // Update end ... - - length += il.length; // Update length - - il.clear(); - - return ret; - } - - /** - * Append another list after instruction i contained in this list. - * Consumes argument list, i.e., it becomes empty. - * - * @param i where to append the instruction list - * @param il Instruction list to append to this one - * @return instruction handle pointing to the <B>first</B> appended instruction - */ - public InstructionHandle append(Instruction i, InstructionList il) { - InstructionHandle ih; - - if((ih = findInstruction2(i)) == null) // Also applies for empty list - throw new ClassGenException("Instruction " + i + - " is not contained in this list."); - - return append(ih, il); - } - - /** - * Append another list to this one. - * Consumes argument list, i.e., it becomes empty. - * - * @param il list to append to end of this list - * @return instruction handle of the <B>first</B> appended instruction - */ - public InstructionHandle append(InstructionList il) { - if(il == null) - throw new ClassGenException("Appending null InstructionList"); - - if(il.isEmpty()) // Nothing to do - return null; - - if(isEmpty()) { - start = il.start; - end = il.end; - length = il.length; - - il.clear(); - - return start; - } else - return append(end, il); // was end.instruction - } - - /** - * Append an instruction to the end of this list. - * - * @param ih instruction to append - */ - private void append(InstructionHandle ih) { - if(isEmpty()) { - start = end = ih; - ih.next = ih.prev = null; - } - else { - end.next = ih; - ih.prev = end; - ih.next = null; - end = ih; - } - - length++; // Update length - } - - /** - * Append an instruction to the end of this list. - * - * @param i instruction to append - * @return instruction handle of the appended instruction - */ - public InstructionHandle append(Instruction i) { - InstructionHandle ih = InstructionHandle.getInstructionHandle(i); - append(ih); - - return ih; - } - - /** - * Append a branch instruction to the end of this list. - * - * @param i branch instruction to append - * @return branch instruction handle of the appended instruction - */ - public BranchHandle append(InstructionBranch i) { - BranchHandle ih = BranchHandle.getBranchHandle(i); - append(ih); - - return ih; - } - - /** - * Append a single instruction j after another instruction i, which - * must be in this list of course! - * - * @param i Instruction in list - * @param j Instruction to append after i in list - * @return instruction handle of the first appended instruction - */ - public InstructionHandle append(Instruction i, Instruction j) { - return append(i, new InstructionList(j)); - } - - - /** - * Append an instruction after instruction (handle) ih contained in this list. - * - * @param ih where to append the instruction list - * @param i Instruction to append - * @return instruction handle pointing to the <B>first</B> appended instruction - */ - public InstructionHandle append(InstructionHandle ih, Instruction i) { - return append(ih, new InstructionList(i)); - } - - /** - * Append an instruction after instruction (handle) ih contained in this list. - * - * @param ih where to append the instruction list - * @param i Instruction to append - * @return instruction handle pointing to the <B>first</B> appended instruction - */ - public BranchHandle append(InstructionHandle ih, InstructionBranch i) { - BranchHandle bh = BranchHandle.getBranchHandle(i); - InstructionList il = new InstructionList(); - il.append(bh); - - append(ih, il); - - return bh; - } - - /** - * Insert another list before Instruction handle ih contained in this list. - * Consumes argument list, i.e., it becomes empty. - * - * @param i where to append the instruction list - * @param il Instruction list to insert - * @return instruction handle of the first inserted instruction - */ - public InstructionHandle insert(InstructionHandle ih, InstructionList il) { - if(il == null) - throw new ClassGenException("Inserting null InstructionList"); - - if(il.isEmpty()) // Nothing to do - return ih; - - InstructionHandle prev = ih.prev, ret = il.start; - - ih.prev = il.end; - il.end.next = ih; - - il.start.prev = prev; - - if(prev != null) // ih == start ? - prev.next = il.start; - else - start = il.start; // Update start ... - - length += il.length; // Update length - - il.clear(); - - return ret; - } - - /** - * Insert another list. - * - * @param il list to insert before start of this list - * @return instruction handle of the first inserted instruction - */ - public InstructionHandle insert(InstructionList il) { - if(isEmpty()) { - append(il); // Code is identical for this case - return start; - } - else - return insert(start, il); - } - - /** - * Insert an instruction at start of this list. - * - * @param ih instruction to insert - */ - private void insert(InstructionHandle ih) { - if(isEmpty()) { - start = end = ih; - ih.next = ih.prev = null; - } else { - start.prev = ih; - ih.next = start; - ih.prev = null; - start = ih; - } - - length++; - } - - /** - * Insert another list before Instruction i contained in this list. - * Consumes argument list, i.e., it becomes empty. - * - * @param i where to append the instruction list - * @param il Instruction list to insert - * @return instruction handle pointing to the first inserted instruction, - * i.e., il.getStart() - */ - public InstructionHandle insert(Instruction i, InstructionList il) { - InstructionHandle ih; - - if((ih = findInstruction1(i)) == null) - throw new ClassGenException("Instruction " + i + - " is not contained in this list."); - - return insert(ih, il); - } - - /** - * Insert an instruction at start of this list. - * - * @param i instruction to insert - * @return instruction handle of the inserted instruction - */ - public InstructionHandle insert(Instruction i) { - InstructionHandle ih = InstructionHandle.getInstructionHandle(i); - insert(ih); - - return ih; - } - - /** - * Insert a branch instruction at start of this list. - * - * @param i branch instruction to insert - * @return branch instruction handle of the appended instruction - */ - public BranchHandle insert(InstructionBranch i) { - BranchHandle ih = BranchHandle.getBranchHandle(i); - insert(ih); - return ih; - } - - /** - * Insert a single instruction j before another instruction i, which - * must be in this list of course! - * - * @param i Instruction in list - * @param j Instruction to insert before i in list - * @return instruction handle of the first inserted instruction - */ - public InstructionHandle insert(Instruction i, Instruction j) { - return insert(i, new InstructionList(j)); - } - - - /** - * Insert an instruction before instruction (handle) ih contained in this list. - * - * @param ih where to insert to the instruction list - * @param i Instruction to insert - * @return instruction handle of the first inserted instruction - */ - public InstructionHandle insert(InstructionHandle ih, Instruction i) { - return insert(ih, new InstructionList(i)); - } - - /** - * Insert an instruction before instruction (handle) ih contained in this list. - * - * @param ih where to insert to the instruction list - * @param i Instruction to insert - * @return instruction handle of the first inserted instruction - */ - public BranchHandle insert(InstructionHandle ih, InstructionBranch i) { - BranchHandle bh = BranchHandle.getBranchHandle(i); - InstructionList il = new InstructionList(); - il.append(bh); - - insert(ih, il); - - return bh; - } - - /** - * Take all instructions (handles) from "start" to "end" and append them after the - * new location "target". Of course, "end" must be after "start" and target must - * not be located withing this range. If you want to move something to the start of - * the list use null as value for target.<br> - * Any instruction targeters pointing to handles within the block, keep their targets. - * - * @param start of moved block - * @param end of moved block - * @param target of moved block - */ - public void move(InstructionHandle start, InstructionHandle end, InstructionHandle target) { - // Step 1: Check constraints - - if((start == null) || (end == null)) - throw new ClassGenException("Invalid null handle: From " + start + " to " + end); - - if((target == start) || (target == end)) - throw new ClassGenException("Invalid range: From " + start + " to " + end + - " contains target " + target); - - for(InstructionHandle ih = start; ih != end.next; ih = ih.next) { - if(ih == null) // At end of list, end not found yet - throw new ClassGenException("Invalid range: From " + start + " to " + end); - else if(ih == target) // target may be null - throw new ClassGenException("Invalid range: From " + start + " to " + end + - " contains target " + target); - } - - // Step 2: Temporarily remove the given instructions from the list - - InstructionHandle prev = start.prev, next = end.next; - - if(prev != null) - prev.next = next; - else // start == this.start! - this.start = next; - - if(next != null) - next.prev = prev; - else // end == this.end! - this.end = prev; - - start.prev = end.next = null; - - // Step 3: append after target - - if(target == null) { // append to start of list - end.next = this.start; - this.start = start; - } else { - next = target.next; - - target.next = start; - start.prev = target; - end.next = next; - - if(next != null) - next.prev = end; - } - } - - /** - * Move a single instruction (handle) to a new location. - * - * @param ih moved instruction - * @param target new location of moved instruction - */ - public void move(InstructionHandle ih, InstructionHandle target) { - move(ih, ih, target); - } - - /** - * Remove from instruction 'prev' to instruction 'next' both contained - * in this list. - * - * If careAboutLostTargeters is true then this method will throw a - * TargetLostException when one of the removed instruction handles - * is still being targeted. - * - * @param prev where to start deleting (predecessor, exclusive) - * @param next where to end deleting (successor, exclusive) - */ - private void remove(InstructionHandle prev, InstructionHandle next, boolean careAboutLostTargeters) throws TargetLostException { - InstructionHandle first, last; // First and last deleted instruction - - if ((prev == null) && (next == null)) { // singleton list - first = last = start; - start = end = null; - } else { - if (prev == null) { // At start of list - first = start; - start = next; - } else { - first = prev.next; - prev.next = next; - } - if (next == null) { // At end of list - last = end; - end = prev; - } else { - last = next.prev; - next.prev = prev; - } - } - - first.prev = null; // Completely separated from rest of list - last.next = null; - - if (!careAboutLostTargeters) return; - - ArrayList target_vec = new ArrayList(); - - for(InstructionHandle ih=first; ih != null; ih = ih.next) - ih.getInstruction().dispose(); // e.g. BranchInstructions release their targets - - StringBuffer buf = new StringBuffer("{ "); - for(InstructionHandle ih=first; ih != null; ih = next) { - next = ih.next; - length--; - - if(ih.hasTargeters()) { // Still got targeters? - InstructionTargeter[] targeters = ih.getTargeters(); - boolean isOK = false; - for (int i = 0; i < targeters.length; i++) { - InstructionTargeter instructionTargeter = targeters[i]; - if (instructionTargeter.getClass().getName().endsWith("ShadowRange") || - instructionTargeter.getClass().getName().endsWith("ExceptionRange") || - instructionTargeter.getClass().getName().endsWith("LineNumberTag") ) isOK=true; - else System.out.println(instructionTargeter.getClass()); - } - if (!isOK) { - - target_vec.add(ih); - buf.append(ih.toString(true) + " "); - ih.next = ih.prev = null; - } else { - ih.dispose(); - } - } else { - ih.dispose(); - } - } - - buf.append("}"); - - if(!target_vec.isEmpty()) { - InstructionHandle[] targeted = new InstructionHandle[target_vec.size()]; - target_vec.toArray(targeted); - throw new TargetLostException(targeted, buf.toString()); - } - } - - /** - * Remove instruction from this list. The corresponding Instruction - * handles must not be reused! - * - * @param ih instruction (handle) to remove - */ - public void delete(InstructionHandle ih) throws TargetLostException { - remove(ih.prev, ih.next,false); - } - - /** - * Remove instruction from this list. The corresponding Instruction - * handles must not be reused! - * - * @param i instruction to remove - */ -// public void delete(Instruction i) throws TargetLostException { -// InstructionHandle ih; -// -// if((ih = findInstruction1(i)) == null) -// throw new ClassGenException("Instruction " + i + -// " is not contained in this list."); -// delete(ih); -// } - - /** - * Remove instructions from instruction `from' to instruction `to' contained - * in this list. The user must ensure that `from' is an instruction before - * `to', or risk havoc. The corresponding Instruction handles must not be reused! - * - * @param from where to start deleting (inclusive) - * @param to where to end deleting (inclusive) - */ - public void delete(InstructionHandle from, InstructionHandle to) - throws TargetLostException - { - remove(from.prev, to.next,false); - } - - /** - * Remove instructions from instruction `from' to instruction `to' contained - * in this list. The user must ensure that `from' is an instruction before - * `to', or risk havoc. The corresponding Instruction handles must not be reused! - * - * @param from where to start deleting (inclusive) - * @param to where to end deleting (inclusive) - */ - public void delete(Instruction from, Instruction to) throws TargetLostException { - InstructionHandle from_ih, to_ih; - - if((from_ih = findInstruction1(from)) == null) - throw new ClassGenException("Instruction " + from + - " is not contained in this list."); - - if((to_ih = findInstruction2(to)) == null) - throw new ClassGenException("Instruction " + to + - " is not contained in this list."); - delete(from_ih, to_ih); - } - - /** - * Search for given Instruction reference, start at beginning of list. - * - * @param i instruction to search for - * @return instruction found on success, null otherwise - */ - private InstructionHandle findInstruction1(Instruction i) { - for(InstructionHandle ih=start; ih != null; ih = ih.next) - if(ih.instruction == i) - return ih; - - return null; - } - - /** - * Search for given Instruction reference, start at end of list - * - * @param i instruction to search for - * @return instruction found on success, null otherwise - */ - private InstructionHandle findInstruction2(Instruction i) { - for(InstructionHandle ih=end; ih != null; ih = ih.prev) - if(ih.instruction == i) - return ih; - - return null; - } - - public boolean contains(InstructionHandle i) { - if(i == null) - return false; - - for(InstructionHandle ih=start; ih != null; ih = ih.next) - if(ih == i) - return true; - - return false; - } - - public boolean contains(Instruction i) { - return findInstruction1(i) != null; - } - - public void setPositions() { - setPositions(false); - } - - /** - * Give all instructions their position number (offset in byte stream), i.e., - * make the list ready to be dumped. - * - * @param check Perform sanity checks, e.g. if all targeted instructions really belong - * to this list - */ - public void setPositions(boolean check) { - int max_additional_bytes = 0, additional_bytes = 0; - int index = 0, count = 0; - int[] pos = new int[length]; - - // Pass 0: Sanity checks - if (check) { - for (InstructionHandle ih=start; ih != null; ih = ih.next) { - Instruction i = ih.instruction; - - if (i instanceof InstructionBranch) { // target instruction within list? - Instruction inst = ((InstructionBranch)i).getTarget().instruction; - if(!contains(inst)) - throw new ClassGenException("Branch target of " + - Constants.OPCODE_NAMES[i.opcode] + ":" + - inst + " not in instruction list"); - - if(i instanceof InstructionSelect) { - InstructionHandle[] targets = ((InstructionSelect)i).getTargets(); - - for(int j=0; j < targets.length; j++) { - inst = targets[j].instruction; - if(!contains(inst)) - throw new ClassGenException("Branch target of " + - Constants.OPCODE_NAMES[i.opcode] + ":" + - inst + " not in instruction list"); - } - } - - if(!(ih instanceof BranchHandle)) - throw new ClassGenException("Branch instruction " + - Constants.OPCODE_NAMES[i.opcode] + ":" + - inst + " not contained in BranchHandle."); - + + if (il.isEmpty()) { + return null; + } + + if (isEmpty()) { + start = il.start; + end = il.end; + length = il.length; + + il.clear(); + + return start; + } else { + return append(end, il); // was end.instruction } - } - } - - // Pass 1: Set position numbers and sum up the maximum number of bytes an - // instruction may be shifted. - for (InstructionHandle ih=start; ih != null; ih = ih.next) { - Instruction i = ih.instruction; - ih.setPosition(index); - pos[count++] = index; - - /* Get an estimate about how many additional bytes may be added, because - * BranchInstructions may have variable length depending on the target - * offset (short vs. int) or alignment issues (TABLESWITCH and - * LOOKUPSWITCH). - */ - switch(i.opcode) { - case Constants.JSR: - case Constants.GOTO: - max_additional_bytes += 2; - break; - - case Constants.TABLESWITCH: - case Constants.LOOKUPSWITCH: - max_additional_bytes += 3; - break; - } - index += i.getLength(); - } - - /* Pass 2: Expand the variable-length (Branch)Instructions depending on - * the target offset (short or int) and ensure that branch targets are - * within this list. - */ - for (InstructionHandle ih=start; ih != null; ih = ih.next) { - additional_bytes += ih.updatePosition(additional_bytes, max_additional_bytes); - } - - /* Pass 3: Update position numbers (which may have changed due to the - * preceding expansions), like pass 1. - */ - index=count=0; - for(InstructionHandle ih=start; ih != null; ih = ih.next) { - Instruction i = ih.instruction; - ih.setPosition(index); - pos[count++] = index; - index += i.getLength(); - } - - byte_positions = new int[count]; // Trim to proper size - System.arraycopy(pos, 0, byte_positions, 0, count); - } - - /** - * When everything is finished, use this method to convert the instruction - * list into an array of bytes. - * - * @return the byte code ready to be dumped - */ - public byte[] getByteCode() { - // Update position indices of instructions - setPositions(); - - ByteArrayOutputStream b = new ByteArrayOutputStream(); - DataOutputStream out = new DataOutputStream(b); - - try { - for(InstructionHandle ih=start; ih != null; ih = ih.next) { - Instruction i = ih.instruction; - i.dump(out); // Traverse list - } - } catch(IOException e) { - System.err.println(e); - return null; - } - byte[] byteCode = b.toByteArray(); - if (byteCode.length > Constants.MAX_CODE_SIZE) - throw new ClassGenException("Code size too big: " + byteCode.length); - - return byteCode; - } - - /** - * @return an array of instructions without target information for branch instructions. - */ - public Instruction[] getInstructions() { - ByteSequence bytes = new ByteSequence(getByteCode()); - ArrayList instructions = new ArrayList(); - - try { - while(bytes.available() > 0) { - instructions.add(Instruction.readInstruction(bytes)); - } - } catch(IOException e) { throw new ClassGenException(e.toString()); } - - Instruction[] result = new Instruction[instructions.size()]; - instructions.toArray(result); - return result; - } - - public String toString() { - return toString(true); - } - - /** - * @param verbose toggle output format - * @return String containing all instructions in this list. - */ - public String toString(boolean verbose) { - StringBuffer buf = new StringBuffer(); - - for(InstructionHandle ih=start; ih != null; ih = ih.next) { - buf.append(ih.toString(verbose) + "\n"); - } - - return buf.toString(); - } - - /** - * @return Enumeration that lists all instructions (handles) - */ - public Iterator iterator() { - return new Iterator() { - private InstructionHandle ih = start; - - public Object next() { - InstructionHandle i = ih; - ih = ih.next; - return i; - } - - public void remove() { - throw new UnsupportedOperationException(); - } - - public boolean hasNext() { return ih != null; } - }; - } - - /** - * @return array containing all instructions (handles) - */ - public InstructionHandle[] getInstructionHandles() { - InstructionHandle[] ihs = new InstructionHandle[length]; - InstructionHandle ih = start; - - for(int i=0; i < length; i++) { - ihs[i] = ih; - ih = ih.next; - } - - return ihs; - } - - /** - * Get positions (offsets) of all instructions in the list. This relies on that - * the list has been freshly created from an byte code array, or that setPositions() - * has been called. Otherwise this may be inaccurate. - * - * @return array containing all instruction's offset in byte code - */ - public int[] getInstructionPositions() { return byte_positions; } - - /** - * @return complete, i.e., deep copy of this list - */ - public InstructionList copy() { - HashMap map = new HashMap(); - InstructionList il = new InstructionList(); - - /* Pass 1: Make copies of all instructions, append them to the new list - * and associate old instruction references with the new ones, i.e., - * a 1:1 mapping. - */ - for(InstructionHandle ih=start; ih != null; ih = ih.next) { - Instruction i = ih.instruction; - Instruction c = i.copy(); // Use clone for shallow copy - - if(c instanceof InstructionBranch) - map.put(ih, il.append((InstructionBranch)c)); - else - map.put(ih, il.append(c)); - } - - /* Pass 2: Update branch targets. - */ - InstructionHandle ih=start; - InstructionHandle ch=il.start; - - while(ih != null) { - Instruction i = ih.instruction; - Instruction c = ch.instruction; - - if(i instanceof InstructionBranch) { - InstructionBranch bi = (InstructionBranch)i; - InstructionBranch bc = (InstructionBranch)c; - InstructionHandle itarget = bi.getTarget(); // old target - - // New target is in hash map - bc.setTarget((InstructionHandle)map.get(itarget)); - - if(bi instanceof InstructionSelect) { // Either LOOKUPSWITCH or TABLESWITCH - InstructionHandle[] itargets = ((InstructionSelect)bi).getTargets(); - InstructionHandle[] ctargets = ((InstructionSelect)bc).getTargets(); - - for(int j=0; j < itargets.length; j++) { // Update all targets - ctargets[j] = (InstructionHandle)map.get(itargets[j]); - } } - } - - ih = ih.next; - ch = ch.next; - } - - return il; - } - - /** Replace all references to the old constant pool with references to the new - * constant pool - */ - public void replaceConstantPool(ConstantPool old_cp, ConstantPool new_cp) { - for(InstructionHandle ih=start; ih != null; ih = ih.next) { - Instruction i = ih.instruction; - - if(i.isConstantPoolInstruction()) { - InstructionCP ci = (InstructionCP)i; - Constant c = old_cp.getConstant(ci.getIndex()); - ci.setIndex(new_cp.addConstant(c, old_cp)); - } - } - } - - private void clear() { - start = end = null; - length = 0; - } - - /** - * Delete contents of list. Provides besser memory utilization, - * because the system then may reuse the instruction handles. This - * method is typically called right after - * <href="MethodGen.html#getMethod()">MethodGen.getMethod()</a>. - */ - public void dispose() { - // Traverse in reverse order, because ih.next is overwritten - for(InstructionHandle ih=end; ih != null; ih = ih.prev) - /* Causes BranchInstructions to release target and targeters, because it - * calls dispose() on the contained instruction. - */ - ih.dispose(); - - clear(); - } - - /** - * @return start of list - */ - public InstructionHandle getStart() { return start; } - - /** - * @return end of list - */ - public InstructionHandle getEnd() { return end; } - - /** - * @return length of list (Number of instructions, not bytes) - */ - public int getLength() { return length; } - - /** - * @return length of list (Number of instructions, not bytes) - */ - public int size() { return length; } - - /** - * Redirect all references from old_target to new_target, i.e., update targets - * of branch instructions. - * - * @param old_target the old target instruction handle - * @param new_target the new target instruction handle - */ - public void redirectBranches(InstructionHandle old_target, - InstructionHandle new_target) { - for(InstructionHandle ih = start; ih != null; ih = ih.next) { - Instruction i = ih.getInstruction(); - - if(i instanceof InstructionBranch) { - InstructionBranch b = (InstructionBranch)i; - InstructionHandle target = b.getTarget(); - - if(target == old_target) - b.setTarget(new_target); - - if(b instanceof InstructionSelect) { // Either LOOKUPSWITCH or TABLESWITCH - InstructionHandle[] targets = ((InstructionSelect)b).getTargets(); - - for(int j=0; j < targets.length; j++) // Update targets - if(targets[j] == old_target) - ((InstructionSelect)b).setTarget(j, new_target); + + /** + * Append an instruction to the end of this list. + * + * @param ih instruction to append + */ + private void append(InstructionHandle ih) { + if (isEmpty()) { + start = end = ih; + ih.next = ih.prev = null; + } else { + end.next = ih; + ih.prev = end; + ih.next = null; + end = ih; + } + + length++; // Update length } - } - } - } - - /** - * Redirect all references of local variables from old_target to new_target. - * - * @param lg array of local variables - * @param old_target the old target instruction handle - * @param new_target the new target instruction handle - * @see MethodGen - */ - public void redirectLocalVariables(LocalVariableGen[] lg, - InstructionHandle old_target, - InstructionHandle new_target) { - for(int i=0; i < lg.length; i++) { - InstructionHandle start = lg[i].getStart(); - InstructionHandle end = lg[i].getEnd(); - - if (start == old_target) lg[i].setStart(new_target); - if (end == old_target) lg[i].setEnd(new_target); - } - } - - /** - * Redirect all references of exception handlers from old_target to new_target. - * - * @param exceptions array of exception handlers - * @param old_target the old target instruction handle - * @param new_target the new target instruction handle - * @see MethodGen - */ - public void redirectExceptionHandlers(CodeExceptionGen[] exceptions, - InstructionHandle old_target, - InstructionHandle new_target) { - for(int i=0; i < exceptions.length; i++) { - if(exceptions[i].getStartPC() == old_target) - exceptions[i].setStartPC(new_target); - - if(exceptions[i].getEndPC() == old_target) - exceptions[i].setEndPC(new_target); - - if(exceptions[i].getHandlerPC() == old_target) - exceptions[i].setHandlerPC(new_target); - } - } + /** + * Append an instruction to the end of this list. + * + * @param i instruction to append + * @return instruction handle of the appended instruction + */ + public InstructionHandle append(Instruction i) { + InstructionHandle ih = InstructionHandle.getInstructionHandle(i); + append(ih); + + return ih; + } -} + /** + * Append a branch instruction to the end of this list. + * + * @param i branch instruction to append + * @return branch instruction handle of the appended instruction + */ + public BranchHandle append(InstructionBranch i) { + BranchHandle ih = BranchHandle.getBranchHandle(i); + append(ih); + + return ih; + } + + /** + * Append a single instruction j after another instruction i, which must be in this list of course! + * + * @param i Instruction in list + * @param j Instruction to append after i in list + * @return instruction handle of the first appended instruction + */ + public InstructionHandle append(Instruction i, Instruction j) { + return append(i, new InstructionList(j)); + } + + /** + * Append an instruction after instruction (handle) ih contained in this list. + * + * @param ih where to append the instruction list + * @param i Instruction to append + * @return instruction handle pointing to the <B>first</B> appended instruction + */ + public InstructionHandle append(InstructionHandle ih, Instruction i) { + return append(ih, new InstructionList(i)); + } + + /** + * Append an instruction after instruction (handle) ih contained in this list. + * + * @param ih where to append the instruction list + * @param i Instruction to append + * @return instruction handle pointing to the <B>first</B> appended instruction + */ + public BranchHandle append(InstructionHandle ih, InstructionBranch i) { + BranchHandle bh = BranchHandle.getBranchHandle(i); + InstructionList il = new InstructionList(); + il.append(bh); + + append(ih, il); + + return bh; + } + + /** + * Insert another list before Instruction handle ih contained in this list. Consumes argument list, i.e., it becomes empty. + * + * @param i where to append the instruction list + * @param il Instruction list to insert + * @return instruction handle of the first inserted instruction + */ + public InstructionHandle insert(InstructionHandle ih, InstructionList il) { + if (il == null) { + throw new ClassGenException("Inserting null InstructionList"); + } + + if (il.isEmpty()) { + return ih; + } + + InstructionHandle prev = ih.prev, ret = il.start; + + ih.prev = il.end; + il.end.next = ih; + + il.start.prev = prev; + + if (prev != null) { + prev.next = il.start; + } else { + start = il.start; // Update start ... + } + + length += il.length; // Update length + + il.clear(); + + return ret; + } + + /** + * Insert another list. + * + * @param il list to insert before start of this list + * @return instruction handle of the first inserted instruction + */ + public InstructionHandle insert(InstructionList il) { + if (isEmpty()) { + append(il); // Code is identical for this case + return start; + } else { + return insert(start, il); + } + } + + /** + * Insert an instruction at start of this list. + * + * @param ih instruction to insert + */ + private void insert(InstructionHandle ih) { + if (isEmpty()) { + start = end = ih; + ih.next = ih.prev = null; + } else { + start.prev = ih; + ih.next = start; + ih.prev = null; + start = ih; + } + + length++; + } + + /** + * Insert another list before Instruction i contained in this list. Consumes argument list, i.e., it becomes empty. + * + * @param i where to append the instruction list + * @param il Instruction list to insert + * @return instruction handle pointing to the first inserted instruction, i.e., il.getStart() + */ + public InstructionHandle insert(Instruction i, InstructionList il) { + InstructionHandle ih; + + if ((ih = findInstruction1(i)) == null) { + throw new ClassGenException("Instruction " + i + " is not contained in this list."); + } + + return insert(ih, il); + } + + /** + * Insert an instruction at start of this list. + * + * @param i instruction to insert + * @return instruction handle of the inserted instruction + */ + public InstructionHandle insert(Instruction i) { + InstructionHandle ih = InstructionHandle.getInstructionHandle(i); + insert(ih); + + return ih; + } + + /** + * Insert a branch instruction at start of this list. + * + * @param i branch instruction to insert + * @return branch instruction handle of the appended instruction + */ + public BranchHandle insert(InstructionBranch i) { + BranchHandle ih = BranchHandle.getBranchHandle(i); + insert(ih); + return ih; + } + + /** + * Insert a single instruction j before another instruction i, which must be in this list of course! + * + * @param i Instruction in list + * @param j Instruction to insert before i in list + * @return instruction handle of the first inserted instruction + */ + public InstructionHandle insert(Instruction i, Instruction j) { + return insert(i, new InstructionList(j)); + } + + /** + * Insert an instruction before instruction (handle) ih contained in this list. + * + * @param ih where to insert to the instruction list + * @param i Instruction to insert + * @return instruction handle of the first inserted instruction + */ + public InstructionHandle insert(InstructionHandle ih, Instruction i) { + return insert(ih, new InstructionList(i)); + } + + /** + * Insert an instruction before instruction (handle) ih contained in this list. + * + * @param ih where to insert to the instruction list + * @param i Instruction to insert + * @return instruction handle of the first inserted instruction + */ + public BranchHandle insert(InstructionHandle ih, InstructionBranch i) { + BranchHandle bh = BranchHandle.getBranchHandle(i); + InstructionList il = new InstructionList(); + il.append(bh); + + insert(ih, il); + + return bh; + } + + /** + * Take all instructions (handles) from "start" to "end" and append them after the new location "target". Of course, "end" must + * be after "start" and target must not be located withing this range. If you want to move something to the start of the list + * use null as value for target.<br> + * Any instruction targeters pointing to handles within the block, keep their targets. + * + * @param start of moved block + * @param end of moved block + * @param target of moved block + */ + public void move(InstructionHandle start, InstructionHandle end, InstructionHandle target) { + // Step 1: Check constraints + + if (start == null || end == null) { + throw new ClassGenException("Invalid null handle: From " + start + " to " + end); + } + + if (target == start || target == end) { + throw new ClassGenException("Invalid range: From " + start + " to " + end + " contains target " + target); + } + + for (InstructionHandle ih = start; ih != end.next; ih = ih.next) { + if (ih == null) { + throw new ClassGenException("Invalid range: From " + start + " to " + end); + } else if (ih == target) { + throw new ClassGenException("Invalid range: From " + start + " to " + end + " contains target " + target); + } + } + + // Step 2: Temporarily remove the given instructions from the list + + InstructionHandle prev = start.prev, next = end.next; + + if (prev != null) { + prev.next = next; + } else { + this.start = next; + } + + if (next != null) { + next.prev = prev; + } else { + this.end = prev; + } + + start.prev = end.next = null; + + // Step 3: append after target + + if (target == null) { // append to start of list + end.next = this.start; + this.start = start; + } else { + next = target.next; + + target.next = start; + start.prev = target; + end.next = next; + + if (next != null) { + next.prev = end; + } + } + } + + /** + * Move a single instruction (handle) to a new location. + * + * @param ih moved instruction + * @param target new location of moved instruction + */ + public void move(InstructionHandle ih, InstructionHandle target) { + move(ih, ih, target); + } + + /** + * Remove from instruction 'prev' to instruction 'next' both contained in this list. + * + * If careAboutLostTargeters is true then this method will throw a TargetLostException when one of the removed instruction + * handles is still being targeted. + * + * @param prev where to start deleting (predecessor, exclusive) + * @param next where to end deleting (successor, exclusive) + */ + private void remove(InstructionHandle prev, InstructionHandle next, boolean careAboutLostTargeters) throws TargetLostException { + InstructionHandle first, last; // First and last deleted instruction + + if (prev == null && next == null) { // singleton list + first = last = start; + start = end = null; + } else { + if (prev == null) { // At start of list + first = start; + start = next; + } else { + first = prev.next; + prev.next = next; + } + if (next == null) { // At end of list + last = end; + end = prev; + } else { + last = next.prev; + next.prev = prev; + } + } + + first.prev = null; // Completely separated from rest of list + last.next = null; + + if (!careAboutLostTargeters) { + return; + } + + ArrayList target_vec = new ArrayList(); + + for (InstructionHandle ih = first; ih != null; ih = ih.next) { + ih.getInstruction().dispose(); // e.g. BranchInstructions release their targets + } + + StringBuffer buf = new StringBuffer("{ "); + for (InstructionHandle ih = first; ih != null; ih = next) { + next = ih.next; + length--; + + Set targeters = ih.getTargeters(); + boolean isOK = false; + Iterator tIter = targeters.iterator(); + while (tIter.hasNext()) { + InstructionTargeter instructionTargeter = (InstructionTargeter) tIter.next(); + if (instructionTargeter.getClass().getName().endsWith("ShadowRange") + || instructionTargeter.getClass().getName().endsWith("ExceptionRange") + || instructionTargeter.getClass().getName().endsWith("LineNumberTag")) { + isOK = true; + } else { + System.out.println(instructionTargeter.getClass()); + } + } + if (!isOK) { + target_vec.add(ih); + buf.append(ih.toString(true) + " "); + ih.next = ih.prev = null; + } else { + ih.dispose(); + } + + // if (ih.hasTargeters()) { // Still got targeters? + // InstructionTargeter[] targeters = ih.getTargeters(); + // boolean isOK = false; + // for (int i = 0; i < targeters.length; i++) { + // InstructionTargeter instructionTargeter = targeters[i]; + // if (instructionTargeter.getClass().getName().endsWith("ShadowRange") + // || instructionTargeter.getClass().getName().endsWith("ExceptionRange") + // || instructionTargeter.getClass().getName().endsWith("LineNumberTag")) { + // isOK = true; + // } else { + // System.out.println(instructionTargeter.getClass()); + // } + // } + // if (!isOK) { + // target_vec.add(ih); + // buf.append(ih.toString(true) + " "); + // ih.next = ih.prev = null; + // } else { + // ih.dispose(); + // } + // } else { + // ih.dispose(); + // } + } + + buf.append("}"); + + if (!target_vec.isEmpty()) { + InstructionHandle[] targeted = new InstructionHandle[target_vec.size()]; + target_vec.toArray(targeted); + throw new TargetLostException(targeted, buf.toString()); + } + } + + /** + * Remove instruction from this list. The corresponding Instruction handles must not be reused! + * + * @param ih instruction (handle) to remove + */ + public void delete(InstructionHandle ih) throws TargetLostException { + remove(ih.prev, ih.next, false); + } + + /** + * Remove instruction from this list. The corresponding Instruction handles must not be reused! + * + * @param i instruction to remove + */ + // public void delete(Instruction i) throws TargetLostException { + // InstructionHandle ih; + // + // if((ih = findInstruction1(i)) == null) + // throw new ClassGenException("Instruction " + i + + // " is not contained in this list."); + // delete(ih); + // } + /** + * Remove instructions from instruction `from' to instruction `to' contained in this list. The user must ensure that `from' is + * an instruction before `to', or risk havoc. The corresponding Instruction handles must not be reused! + * + * @param from where to start deleting (inclusive) + * @param to where to end deleting (inclusive) + */ + public void delete(InstructionHandle from, InstructionHandle to) throws TargetLostException { + remove(from.prev, to.next, false); + } + + /** + * Remove instructions from instruction `from' to instruction `to' contained in this list. The user must ensure that `from' is + * an instruction before `to', or risk havoc. The corresponding Instruction handles must not be reused! + * + * @param from where to start deleting (inclusive) + * @param to where to end deleting (inclusive) + */ + public void delete(Instruction from, Instruction to) throws TargetLostException { + InstructionHandle from_ih, to_ih; + + if ((from_ih = findInstruction1(from)) == null) { + throw new ClassGenException("Instruction " + from + " is not contained in this list."); + } + + if ((to_ih = findInstruction2(to)) == null) { + throw new ClassGenException("Instruction " + to + " is not contained in this list."); + } + delete(from_ih, to_ih); + } + + /** + * Search for given Instruction reference, start at beginning of list. + * + * @param i instruction to search for + * @return instruction found on success, null otherwise + */ + private InstructionHandle findInstruction1(Instruction i) { + for (InstructionHandle ih = start; ih != null; ih = ih.next) { + if (ih.instruction == i) { + return ih; + } + } + + return null; + } + + /** + * Search for given Instruction reference, start at end of list + * + * @param i instruction to search for + * @return instruction found on success, null otherwise + */ + private InstructionHandle findInstruction2(Instruction i) { + for (InstructionHandle ih = end; ih != null; ih = ih.prev) { + if (ih.instruction == i) { + return ih; + } + } + + return null; + } + + public boolean contains(InstructionHandle i) { + if (i == null) { + return false; + } + + for (InstructionHandle ih = start; ih != null; ih = ih.next) { + if (ih == i) { + return true; + } + } + + return false; + } + + public boolean contains(Instruction i) { + return findInstruction1(i) != null; + } + + public void setPositions() { + setPositions(false); + } + + /** + * Give all instructions their position number (offset in byte stream), i.e., make the list ready to be dumped. + * + * @param check Perform sanity checks, e.g. if all targeted instructions really belong to this list + */ + public void setPositions(boolean check) { + int max_additional_bytes = 0, additional_bytes = 0; + int index = 0, count = 0; + int[] pos = new int[length]; + + // Pass 0: Sanity checks + if (check) { + for (InstructionHandle ih = start; ih != null; ih = ih.next) { + Instruction i = ih.instruction; + + if (i instanceof InstructionBranch) { // target instruction within list? + Instruction inst = ((InstructionBranch) i).getTarget().instruction; + if (!contains(inst)) { + throw new ClassGenException("Branch target of " + Constants.OPCODE_NAMES[i.opcode] + ":" + inst + + " not in instruction list"); + } + + if (i instanceof InstructionSelect) { + InstructionHandle[] targets = ((InstructionSelect) i).getTargets(); + + for (int j = 0; j < targets.length; j++) { + inst = targets[j].instruction; + if (!contains(inst)) { + throw new ClassGenException("Branch target of " + Constants.OPCODE_NAMES[i.opcode] + ":" + inst + + " not in instruction list"); + } + } + } + + if (!(ih instanceof BranchHandle)) { + throw new ClassGenException("Branch instruction " + Constants.OPCODE_NAMES[i.opcode] + ":" + inst + + " not contained in BranchHandle."); + } + + } + } + } + // Pass 1: Set position numbers and sum up the maximum number of bytes an + // instruction may be shifted. + for (InstructionHandle ih = start; ih != null; ih = ih.next) { + Instruction i = ih.instruction; + ih.setPosition(index); + pos[count++] = index; + + /* + * Get an estimate about how many additional bytes may be added, because BranchInstructions may have variable length + * depending on the target offset (short vs. int) or alignment issues (TABLESWITCH and LOOKUPSWITCH). + */ + switch (i.opcode) { + case Constants.JSR: + case Constants.GOTO: + max_additional_bytes += 2; + break; + + case Constants.TABLESWITCH: + case Constants.LOOKUPSWITCH: + max_additional_bytes += 3; + break; + } + index += i.getLength(); + } + + /* + * Pass 2: Expand the variable-length (Branch)Instructions depending on the target offset (short or int) and ensure that + * branch targets are within this list. + */ + for (InstructionHandle ih = start; ih != null; ih = ih.next) { + additional_bytes += ih.updatePosition(additional_bytes, max_additional_bytes); + } + + /* + * Pass 3: Update position numbers (which may have changed due to the preceding expansions), like pass 1. + */ + index = count = 0; + for (InstructionHandle ih = start; ih != null; ih = ih.next) { + Instruction i = ih.instruction; + ih.setPosition(index); + pos[count++] = index; + index += i.getLength(); + } + + byte_positions = new int[count]; // Trim to proper size + System.arraycopy(pos, 0, byte_positions, 0, count); + } + + /** + * When everything is finished, use this method to convert the instruction list into an array of bytes. + * + * @return the byte code ready to be dumped + */ + public byte[] getByteCode() { + // Update position indices of instructions + setPositions(); + + ByteArrayOutputStream b = new ByteArrayOutputStream(); + DataOutputStream out = new DataOutputStream(b); + + try { + for (InstructionHandle ih = start; ih != null; ih = ih.next) { + Instruction i = ih.instruction; + i.dump(out); // Traverse list + } + } catch (IOException e) { + System.err.println(e); + return null; + } + byte[] byteCode = b.toByteArray(); + if (byteCode.length > Constants.MAX_CODE_SIZE) { + throw new ClassGenException("Code size too big: " + byteCode.length); + } + + return byteCode; + } + + /** + * @return an array of instructions without target information for branch instructions. + */ + public Instruction[] getInstructions() { + ByteSequence bytes = new ByteSequence(getByteCode()); + ArrayList instructions = new ArrayList(); + + try { + while (bytes.available() > 0) { + instructions.add(Instruction.readInstruction(bytes)); + } + } catch (IOException e) { + throw new ClassGenException(e.toString()); + } + + Instruction[] result = new Instruction[instructions.size()]; + instructions.toArray(result); + return result; + } + + public String toString() { + return toString(true); + } + + /** + * @param verbose toggle output format + * @return String containing all instructions in this list. + */ + public String toString(boolean verbose) { + StringBuffer buf = new StringBuffer(); + + for (InstructionHandle ih = start; ih != null; ih = ih.next) { + buf.append(ih.toString(verbose) + "\n"); + } + + return buf.toString(); + } + + /** + * @return Enumeration that lists all instructions (handles) + */ + public Iterator iterator() { + return new Iterator() { + private InstructionHandle ih = start; + + public Object next() { + InstructionHandle i = ih; + ih = ih.next; + return i; + } + + public void remove() { + throw new UnsupportedOperationException(); + } + + public boolean hasNext() { + return ih != null; + } + }; + } + + /** + * @return array containing all instructions (handles) + */ + public InstructionHandle[] getInstructionHandles() { + InstructionHandle[] ihs = new InstructionHandle[length]; + InstructionHandle ih = start; + + for (int i = 0; i < length; i++) { + ihs[i] = ih; + ih = ih.next; + } + + return ihs; + } + + /** + * Get positions (offsets) of all instructions in the list. This relies on that the list has been freshly created from an byte + * code array, or that setPositions() has been called. Otherwise this may be inaccurate. + * + * @return array containing all instruction's offset in byte code + */ + public int[] getInstructionPositions() { + return byte_positions; + } + + /** + * @return complete, i.e., deep copy of this list + */ + public InstructionList copy() { + HashMap map = new HashMap(); + InstructionList il = new InstructionList(); + + /* + * Pass 1: Make copies of all instructions, append them to the new list and associate old instruction references with the + * new ones, i.e., a 1:1 mapping. + */ + for (InstructionHandle ih = start; ih != null; ih = ih.next) { + Instruction i = ih.instruction; + Instruction c = i.copy(); // Use clone for shallow copy + + if (c instanceof InstructionBranch) { + map.put(ih, il.append((InstructionBranch) c)); + } else { + map.put(ih, il.append(c)); + } + } + + /* + * Pass 2: Update branch targets. + */ + InstructionHandle ih = start; + InstructionHandle ch = il.start; + + while (ih != null) { + Instruction i = ih.instruction; + Instruction c = ch.instruction; + + if (i instanceof InstructionBranch) { + InstructionBranch bi = (InstructionBranch) i; + InstructionBranch bc = (InstructionBranch) c; + InstructionHandle itarget = bi.getTarget(); // old target + + // New target is in hash map + bc.setTarget((InstructionHandle) map.get(itarget)); + + if (bi instanceof InstructionSelect) { // Either LOOKUPSWITCH or TABLESWITCH + InstructionHandle[] itargets = ((InstructionSelect) bi).getTargets(); + InstructionHandle[] ctargets = ((InstructionSelect) bc).getTargets(); + + for (int j = 0; j < itargets.length; j++) { // Update all targets + ctargets[j] = (InstructionHandle) map.get(itargets[j]); + } + } + } + + ih = ih.next; + ch = ch.next; + } + + return il; + } + + /** + * Replace all references to the old constant pool with references to the new constant pool + */ + public void replaceConstantPool(ConstantPool old_cp, ConstantPool new_cp) { + for (InstructionHandle ih = start; ih != null; ih = ih.next) { + Instruction i = ih.instruction; + + if (i.isConstantPoolInstruction()) { + InstructionCP ci = (InstructionCP) i; + Constant c = old_cp.getConstant(ci.getIndex()); + ci.setIndex(new_cp.addConstant(c, old_cp)); + } + } + } + + private void clear() { + start = end = null; + length = 0; + } + + /** + * Delete contents of list. Provides besser memory utilization, because the system then may reuse the instruction handles. This + * method is typically called right after <href="MethodGen.html#getMethod()">MethodGen.getMethod()</a>. + */ + public void dispose() { + // Traverse in reverse order, because ih.next is overwritten + for (InstructionHandle ih = end; ih != null; ih = ih.prev) { + /* + * Causes BranchInstructions to release target and targeters, because it calls dispose() on the contained instruction. + */ + ih.dispose(); + } + + clear(); + } + + /** + * @return start of list + */ + public InstructionHandle getStart() { + return start; + } + + /** + * @return end of list + */ + public InstructionHandle getEnd() { + return end; + } + + /** + * @return length of list (Number of instructions, not bytes) + */ + public int getLength() { + return length; + } + + /** + * @return length of list (Number of instructions, not bytes) + */ + public int size() { + return length; + } + + /** + * Redirect all references from old_target to new_target, i.e., update targets of branch instructions. + * + * @param old_target the old target instruction handle + * @param new_target the new target instruction handle + */ + public void redirectBranches(InstructionHandle old_target, InstructionHandle new_target) { + for (InstructionHandle ih = start; ih != null; ih = ih.next) { + Instruction i = ih.getInstruction(); + + if (i instanceof InstructionBranch) { + InstructionBranch b = (InstructionBranch) i; + InstructionHandle target = b.getTarget(); + + if (target == old_target) { + b.setTarget(new_target); + } + + if (b instanceof InstructionSelect) { // Either LOOKUPSWITCH or TABLESWITCH + InstructionHandle[] targets = ((InstructionSelect) b).getTargets(); + + for (int j = 0; j < targets.length; j++) { + if (targets[j] == old_target) { + ((InstructionSelect) b).setTarget(j, new_target); + } + } + } + } + } + } + + /** + * Redirect all references of local variables from old_target to new_target. + * + * @param lg array of local variables + * @param old_target the old target instruction handle + * @param new_target the new target instruction handle + * @see MethodGen + */ + public void redirectLocalVariables(LocalVariableGen[] lg, InstructionHandle old_target, InstructionHandle new_target) { + for (int i = 0; i < lg.length; i++) { + InstructionHandle start = lg[i].getStart(); + InstructionHandle end = lg[i].getEnd(); + + if (start == old_target) { + lg[i].setStart(new_target); + } + if (end == old_target) { + lg[i].setEnd(new_target); + } + } + } + + /** + * Redirect all references of exception handlers from old_target to new_target. + * + * @param exceptions array of exception handlers + * @param old_target the old target instruction handle + * @param new_target the new target instruction handle + * @see MethodGen + */ + public void redirectExceptionHandlers(CodeExceptionGen[] exceptions, InstructionHandle old_target, InstructionHandle new_target) { + for (int i = 0; i < exceptions.length; i++) { + if (exceptions[i].getStartPC() == old_target) { + exceptions[i].setStartPC(new_target); + } + + if (exceptions[i].getEndPC() == old_target) { + exceptions[i].setEndPC(new_target); + } + + if (exceptions[i].getHandlerPC() == old_target) { + exceptions[i].setHandlerPC(new_target); + } + } + } + +} |