+++ /dev/null
-/*******************************************************************************
- * Copyright (c) 2000, 2004 IBM Corporation and others.
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the Common Public License v1.0
- * which accompanies this distribution, and is available at
- * http://www.eclipse.org/legal/cpl-v10.html
- *
- * Contributors:
- * IBM Corporation - initial API and implementation
- *******************************************************************************/
-package org.eclipse.jdt.internal.compiler.codegen;
-
-import org.eclipse.jdt.internal.compiler.lookup.LocalVariableBinding;
-import org.eclipse.jdt.internal.compiler.problem.AbortMethod;
-
-/**
- * This type is a port of smalltalks JavaLabel
- */
-public class Label {
- public CodeStream codeStream;
- final static int POS_NOT_SET = -1;
- public int position = POS_NOT_SET; // position=POS_NOT_SET Then it's pos is not set.
- public int[] forwardReferences = new int[10]; // Add an overflow check here.
- public int forwardReferenceCount = 0;
- private boolean isWide = false;
-
-public Label() {
- // for creating labels ahead of code generation
-}
-/**
- * @param codeStream org.eclipse.jdt.internal.compiler.codegen.CodeStream
- */
-public Label(CodeStream codeStream) {
- this.codeStream = codeStream;
-}
-/**
- * Add a forward refrence for the array.
- */
-void addForwardReference(int iPos) {
- int length;
- if (forwardReferenceCount >= (length = forwardReferences.length))
- System.arraycopy(forwardReferences, 0, (forwardReferences = new int[2*length]), 0, length);
- forwardReferences[forwardReferenceCount++] = iPos;
-}
-/**
- * Add a forward refrence for the array.
- */
-public void appendForwardReferencesFrom(Label otherLabel) {
- int otherCount = otherLabel.forwardReferenceCount;
- if (otherCount == 0) return;
- int length = forwardReferences.length;
- int neededSpace = otherCount + forwardReferenceCount;
- if (neededSpace >= length){
- System.arraycopy(forwardReferences, 0, (forwardReferences = new int[neededSpace]), 0, forwardReferenceCount);
- }
- // append other forward references at the end, so they will get updated as well
- System.arraycopy(otherLabel.forwardReferences, 0, forwardReferences, forwardReferenceCount, otherCount);
- forwardReferenceCount = neededSpace;
-}
-/*
-* Put down a reference to the array at the location in the codestream.
-*/
-void branch() {
- if (position == POS_NOT_SET) {
- addForwardReference(codeStream.position);
- // Leave two bytes free to generate the jump afterwards
- codeStream.position += 2;
- codeStream.classFileOffset += 2;
- } else {
- /*
- * Position is set. Write it if it is not a wide branch.
- */
- int offset = position - codeStream.position + 1;
- if (Math.abs(offset) > 0x7FFF && !this.codeStream.wideMode) {
- throw new AbortMethod(CodeStream.RESTART_IN_WIDE_MODE, null);
- }
- codeStream.writeSignedShort(offset);
- }
-}
-/*
-* No support for wide branches yet
-*/
-void branchWide() {
- if (position == POS_NOT_SET) {
- addForwardReference(codeStream.position);
- // Leave 4 bytes free to generate the jump offset afterwards
- isWide = true;
- codeStream.position += 4;
- codeStream.classFileOffset += 4;
- } else { //Position is set. Write it!
- codeStream.writeSignedWord(position - codeStream.position + 1);
- }
-}
-/**
- * @return boolean
- */
-public boolean hasForwardReferences() {
- return forwardReferenceCount != 0;
-}
-/*
- * Some placed labels might be branching to a goto bytecode which we can optimize better.
- */
-public void inlineForwardReferencesFromLabelsTargeting(int gotoLocation) {
-
-/*
- Code required to optimized unreachable gotos.
- public boolean isBranchTarget(int location) {
- Label[] labels = codeStream.labels;
- for (int i = codeStream.countLabels - 1; i >= 0; i--){
- Label label = labels[i];
- if ((label.position == location) && label.isStandardLabel()){
- return true;
- }
- }
- return false;
- }
- */
-
- Label[] labels = codeStream.labels;
- for (int i = codeStream.countLabels - 1; i >= 0; i--){
- Label label = labels[i];
- if ((label.position == gotoLocation) && label.isStandardLabel()){
- this.appendForwardReferencesFrom(label);
- /*
- Code required to optimized unreachable gotos.
- label.position = POS_NOT_SET;
- */
- } else {
- break; // same target labels should be contiguous
- }
- }
-}
-public void initialize(CodeStream stream) {
- this.codeStream = stream;
- this.position = POS_NOT_SET;
- this.forwardReferenceCount = 0;
-}
-public boolean isStandardLabel(){
- return true;
-}
-/*
-* Place the label. If we have forward references resolve them.
-*/
-public void place() { // Currently lacking wide support.
- if (CodeStream.DEBUG) System.out.println("\t\t\t\t<place at: "+codeStream.position+" - "+ this); //$NON-NLS-1$ //$NON-NLS-2$
-
- if (position == POS_NOT_SET) {
- position = codeStream.position;
- codeStream.addLabel(this);
- int oldPosition = position;
- boolean isOptimizedBranch = false;
- // TURNED OFF since fail on 1F4IRD9
- if (forwardReferenceCount != 0) {
- isOptimizedBranch = (forwardReferences[forwardReferenceCount - 1] + 2 == position) && (codeStream.bCodeStream[codeStream.classFileOffset - 3] == Opcodes.OPC_goto);
- if (isOptimizedBranch) {
- codeStream.position = (position -= 3);
- codeStream.classFileOffset -= 3;
- forwardReferenceCount--;
- // also update the PCs in the related debug attributes
- /** OLD CODE
- int index = codeStream.pcToSourceMapSize - 1;
- while ((index >= 0) && (codeStream.pcToSourceMap[index][1] == oldPosition)) {
- codeStream.pcToSourceMap[index--][1] = position;
- }
- */
- // Beginning of new code
- int index = codeStream.pcToSourceMapSize - 2;
- if (codeStream.lastEntryPC == oldPosition) {
- codeStream.lastEntryPC = position;
- }
- if ((index >= 0) && (codeStream.pcToSourceMap[index] == position)) {
- codeStream.pcToSourceMapSize-=2;
- }
- // end of new code
- if (codeStream.generateLocalVariableTableAttributes) {
- LocalVariableBinding locals[] = codeStream.locals;
- for (int i = 0, max = locals.length; i < max; i++) {
- LocalVariableBinding local = locals[i];
- if ((local != null) && (local.initializationCount > 0)) {
- if (local.initializationPCs[((local.initializationCount - 1) << 1) + 1] == oldPosition) {
- // we want to prevent interval of size 0 to have a negative size.
- // see PR 1GIRQLA: ITPJCORE:ALL - ClassFormatError for local variable attribute
- local.initializationPCs[((local.initializationCount - 1) << 1) + 1] = position;
- }
- if (local.initializationPCs[(local.initializationCount - 1) << 1] == oldPosition) {
- local.initializationPCs[(local.initializationCount - 1) << 1] = position;
- }
- }
- }
- }
- }
- }
- for (int i = 0; i < forwardReferenceCount; i++) {
- int offset = position - forwardReferences[i] + 1;
- if (Math.abs(offset) > 0x7FFF && !this.codeStream.wideMode) {
- throw new AbortMethod(CodeStream.RESTART_IN_WIDE_MODE, null);
- }
- if (this.codeStream.wideMode) {
- if (this.isWide) {
- codeStream.writeSignedWord(forwardReferences[i], offset);
- } else {
- codeStream.writeSignedShort(forwardReferences[i], offset);
- }
- } else {
- codeStream.writeSignedShort(forwardReferences[i], offset);
- }
- }
- // For all labels placed at that position we check if we need to rewrite the jump
- // offset. It is the case each time a label had a forward reference to the current position.
- // Like we change the current position, we have to change the jump offset. See 1F4IRD9 for more details.
- if (isOptimizedBranch) {
- for (int i = 0; i < codeStream.countLabels; i++) {
- Label label = codeStream.labels[i];
- if (oldPosition == label.position) {
- label.position = position;
- if (label instanceof CaseLabel) {
- int offset = position - ((CaseLabel) label).instructionPosition;
- for (int j = 0; j < label.forwardReferenceCount; j++) {
- int forwardPosition = label.forwardReferences[j];
- codeStream.writeSignedWord(forwardPosition, offset);
- }
- } else {
- for (int j = 0; j < label.forwardReferenceCount; j++) {
- int forwardPosition = label.forwardReferences[j];
- int offset = position - forwardPosition + 1;
- if (Math.abs(offset) > 0x7FFF && !this.codeStream.wideMode) {
- throw new AbortMethod(CodeStream.RESTART_IN_WIDE_MODE, null);
- }
- if (this.codeStream.wideMode) {
- if (this.isWide) {
- codeStream.writeSignedWord(forwardPosition, offset);
- } else {
- codeStream.writeSignedShort(forwardPosition, offset);
- }
- } else {
- codeStream.writeSignedShort(forwardPosition, offset);
- }
- }
- }
- }
- }
- }
- }
-}
-/**
- * Print out the receiver
- */
-public String toString() {
- String basic = getClass().getName();
- basic = basic.substring(basic.lastIndexOf('.')+1);
- StringBuffer buffer = new StringBuffer(basic);
- buffer.append('@').append(Integer.toHexString(hashCode()));
- buffer.append("(position=").append(position); //$NON-NLS-1$
- buffer.append(", forwards = ["); //$NON-NLS-1$
- for (int i = 0; i < forwardReferenceCount - 1; i++)
- buffer.append(forwardReferences[i] + ", "); //$NON-NLS-1$
- if (forwardReferenceCount >= 1)
- buffer.append(forwardReferences[forwardReferenceCount-1]);
- buffer.append("] )"); //$NON-NLS-1$
- return buffer.toString();
-}
-}
projects / org.ibex.tool.git / blobdiff