org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/codegen/BranchLabel.java - aspectj/org.aspectj.shadows - Git at Google

 /*******************************************************************************
  * Copyright (c) 2000, 2008 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  *     IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.jdt.internal.compiler.codegen;

 import java.util.Arrays;

 import org.eclipse.jdt.internal.compiler.classfmt.ClassFileConstants;
 import org.eclipse.jdt.internal.compiler.lookup.LocalVariableBinding;

 public class BranchLabel extends Label {

 	private int[] forwardReferences = new int[10]; // Add an overflow check here.
 	private int forwardReferenceCount = 0;
 	BranchLabel delegate; //

 	// Label tagbits
 	public int tagBits;
 	public final static int WIDE = 1;
 	public final static int USED = 2;

 public BranchLabel() {
 	// for creating labels ahead of code generation
 }

 /**
  * @param codeStream org.eclipse.jdt.internal.compiler.codegen.CodeStream
  */
 public BranchLabel(CodeStream codeStream) {
 	super(codeStream);
 }

 /**
  * Add a forward refrence for the array.
  */
 void addForwardReference(int pos) {
 	if (this.delegate != null) {
 		this.delegate.addForwardReference(pos);
 		return;
 	}
 	final int count = this.forwardReferenceCount;
 	if (count >= 1) {
 		int previousValue = this.forwardReferences[count - 1];
 		if (previousValue < pos) {
 			int length;
 			if (count >= (length = this.forwardReferences.length))
 				System.arraycopy(this.forwardReferences, 0, (this.forwardReferences = new int[2*length]), 0, length);
 			this.forwardReferences[this.forwardReferenceCount++] = pos;
 		} else if (previousValue > pos) {
 			int[] refs = this.forwardReferences;
 			// check for duplicates
 			for (int i = 0, max = this.forwardReferenceCount; i < max; i++) {
 				if (refs[i] == pos) return; // already recorded
 			}
 			int length;
 			if (count >= (length = refs.length))
 				System.arraycopy(refs, 0, (this.forwardReferences = new int[2*length]), 0, length);
 			this.forwardReferences[this.forwardReferenceCount++] = pos;
 			Arrays.sort(this.forwardReferences, 0, this.forwardReferenceCount);
 		}
 	} else {
 		int length;
 		if (count >= (length = this.forwardReferences.length))
 			System.arraycopy(this.forwardReferences, 0, (this.forwardReferences = new int[2*length]), 0, length);
 		this.forwardReferences[this.forwardReferenceCount++] = pos;
 	}
 }

 /**
  * Makes the current label inline all references to the other label
  */
 public void becomeDelegateFor(BranchLabel otherLabel) {
 	// other label is delegating to receiver from now on
 	otherLabel.delegate = this;

 	// all existing forward refs to other label are inlined into current label
 	final int otherCount = otherLabel.forwardReferenceCount;
 	if (otherCount == 0) return;
 	// need to merge the two sorted arrays of forward references
 	int[] mergedForwardReferences = new int[this.forwardReferenceCount + otherCount];
 	int indexInMerge = 0;
 	int j = 0;
 	int i = 0;
 	int max = this.forwardReferenceCount;
 	int max2 = otherLabel.forwardReferenceCount;
 	loop1 : for (; i < max; i++) {
 		final int value1 = this.forwardReferences[i];
 		for (; j < max2; j++) {
 			final int value2 = otherLabel.forwardReferences[j];
 			if (value1 < value2) {
 				mergedForwardReferences[indexInMerge++] = value1;
 				continue loop1;
 			} else if (value1 == value2) {
 				mergedForwardReferences[indexInMerge++] = value1;
 				j++;
 				continue loop1;
 			} else {
 				mergedForwardReferences[indexInMerge++] = value2;
 			}
 		}
 		mergedForwardReferences[indexInMerge++] = value1;
 	}
 	for (; j < max2; j++) {
 		mergedForwardReferences[indexInMerge++] = otherLabel.forwardReferences[j];
 	}
 	this.forwardReferences = mergedForwardReferences;
 	this.forwardReferenceCount = indexInMerge;
 }

 /*
 * Put down  a reference to the array at the location in the codestream.
 */
 void branch() {
 	this.tagBits |= BranchLabel.USED;
 	if (this.delegate != null) {
 		this.delegate.branch();
 		return;
 	}
 	if (this.position == Label.POS_NOT_SET) {
 		addForwardReference(this.codeStream.position);
 		// Leave two bytes free to generate the jump afterwards
 		this.codeStream.position += 2;
 		this.codeStream.classFileOffset += 2;
 	} else {
 		/*
 		 * Position is set. Write it if it is not a wide branch.
 		 */
 		this.codeStream.writePosition(this);
 	}
 }

 /*
 * No support for wide branches yet
 */
 void branchWide() {
 	this.tagBits |= BranchLabel.USED;
 	if (this.delegate != null) {
 		this.delegate.branchWide();
 		return;
 	}
 	if (this.position == Label.POS_NOT_SET) {
 		addForwardReference(this.codeStream.position);
 		// Leave 4 bytes free to generate the jump offset afterwards
 		this.tagBits |= BranchLabel.WIDE;
 		this.codeStream.position += 4;
 		this.codeStream.classFileOffset += 4;
 	} else { //Position is set. Write it!
 		this.codeStream.writeWidePosition(this);
 	}
 }

 public int forwardReferenceCount() {
 	if (this.delegate != null) this.delegate.forwardReferenceCount();
 	return this.forwardReferenceCount;
 }
 public int[] forwardReferences() {
 	if (this.delegate != null) this.delegate.forwardReferences();
 	return this.forwardReferences;
 }
 public void initialize(CodeStream stream) {
     this.codeStream = stream;
    	this.position = Label.POS_NOT_SET;
 	this.forwardReferenceCount = 0;
 	this.delegate = null;
 }
 public boolean isCaseLabel() {
 	return false;
 }
 public boolean isStandardLabel(){
 	return true;
 }

 /*
 * Place the label. If we have forward references resolve them.
 */
 public void place() { // Currently lacking wide support.
 //	if ((this.tagBits & USED) == 0 && this.forwardReferenceCount == 0) {
 //		return;
 //	}

 	//TODO how can position be set already ? cannot place more than once
 	if (this.position == Label.POS_NOT_SET) {
 		this.position = this.codeStream.position;
 		this.codeStream.addLabel(this);
 		int oldPosition = this.position;
 		boolean isOptimizedBranch = false;
 		if (this.forwardReferenceCount != 0) {
 			isOptimizedBranch = (this.forwardReferences[this.forwardReferenceCount - 1] + 2 == this.position) && (this.codeStream.bCodeStream[this.codeStream.classFileOffset - 3] == Opcodes.OPC_goto);
 			if (isOptimizedBranch) {
 				if (this.codeStream.lastAbruptCompletion == this.position) {
 					this.codeStream.lastAbruptCompletion = -1;
 				}
 				this.codeStream.position = (this.position -= 3);
 				this.codeStream.classFileOffset -= 3;
 				this.forwardReferenceCount--;
 				if (this.codeStream.lastEntryPC == oldPosition) {
 					this.codeStream.lastEntryPC = this.position;
 				}
 				// end of new code
 				if ((this.codeStream.generateAttributes & (ClassFileConstants.ATTR_VARS | ClassFileConstants.ATTR_STACK_MAP_TABLE | ClassFileConstants.ATTR_STACK_MAP)) != 0) {
 					LocalVariableBinding locals[] = this.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] = this.position;
 							}
 							if (local.initializationPCs[(local.initializationCount - 1) << 1] == oldPosition) {
 								local.initializationPCs[(local.initializationCount - 1) << 1] = this.position;
 							}
 						}
 					}
 				}
 				if ((this.codeStream.generateAttributes & ClassFileConstants.ATTR_LINES) != 0) {
 					// we need to remove all entries that is beyond this.position inside the pcToSourcerMap table
 					this.codeStream.removeUnusedPcToSourceMapEntries();
 				}
 			}
 		}
 		for (int i = 0; i < this.forwardReferenceCount; i++) {
 			this.codeStream.writePosition(this, this.forwardReferences[i]);
 		}
 		// 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) {
 			this.codeStream.optimizeBranch(oldPosition, this);
 		}
 	}
 }

 /**
  * 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(this.position); //$NON-NLS-1$
 	if (this.delegate != null) buffer.append("delegate=").append(this.delegate); //$NON-NLS-1$
 	buffer.append(", forwards = ["); //$NON-NLS-1$
 	for (int i = 0; i < this.forwardReferenceCount - 1; i++)
 		buffer.append(this.forwardReferences[i] + ", "); //$NON-NLS-1$
 	if (this.forwardReferenceCount >= 1)
 		buffer.append(this.forwardReferences[this.forwardReferenceCount-1]);
 	buffer.append("] )"); //$NON-NLS-1$
 	return buffer.toString();
 }
 }
	/*******************************************************************************
	* Copyright (c) 2000, 2008 IBM Corporation and others.
	* All rights reserved. This program and the accompanying materials
	* are made available under the terms of the Eclipse Public License v1.0
	* which accompanies this distribution, and is available at
	* http://www.eclipse.org/legal/epl-v10.html
	*
	* Contributors:
	* IBM Corporation - initial API and implementation
	*******************************************************************************/
	package org.eclipse.jdt.internal.compiler.codegen;

	import java.util.Arrays;

	import org.eclipse.jdt.internal.compiler.classfmt.ClassFileConstants;
	import org.eclipse.jdt.internal.compiler.lookup.LocalVariableBinding;

	public class BranchLabel extends Label {

	private int[] forwardReferences = new int[10]; // Add an overflow check here.
	private int forwardReferenceCount = 0;
	BranchLabel delegate; //

	// Label tagbits
	public int tagBits;
	public final static int WIDE = 1;
	public final static int USED = 2;

	public BranchLabel() {
	// for creating labels ahead of code generation
	}

	/**
	* @param codeStream org.eclipse.jdt.internal.compiler.codegen.CodeStream
	*/
	public BranchLabel(CodeStream codeStream) {
	super(codeStream);
	}

	/**
	* Add a forward refrence for the array.
	*/
	void addForwardReference(int pos) {
	if (this.delegate != null) {
	this.delegate.addForwardReference(pos);
	return;
	}
	final int count = this.forwardReferenceCount;
	if (count >= 1) {
	int previousValue = this.forwardReferences[count - 1];
	if (previousValue < pos) {
	int length;
	if (count >= (length = this.forwardReferences.length))
	System.arraycopy(this.forwardReferences, 0, (this.forwardReferences = new int[2*length]), 0, length);
	this.forwardReferences[this.forwardReferenceCount++] = pos;
	} else if (previousValue > pos) {
	int[] refs = this.forwardReferences;
	// check for duplicates
	for (int i = 0, max = this.forwardReferenceCount; i < max; i++) {
	if (refs[i] == pos) return; // already recorded
	}
	int length;
	if (count >= (length = refs.length))
	System.arraycopy(refs, 0, (this.forwardReferences = new int[2*length]), 0, length);
	this.forwardReferences[this.forwardReferenceCount++] = pos;
	Arrays.sort(this.forwardReferences, 0, this.forwardReferenceCount);
	}
	} else {
	int length;
	if (count >= (length = this.forwardReferences.length))
	System.arraycopy(this.forwardReferences, 0, (this.forwardReferences = new int[2*length]), 0, length);
	this.forwardReferences[this.forwardReferenceCount++] = pos;
	}
	}

	/**
	* Makes the current label inline all references to the other label
	*/
	public void becomeDelegateFor(BranchLabel otherLabel) {
	// other label is delegating to receiver from now on
	otherLabel.delegate = this;

	// all existing forward refs to other label are inlined into current label
	final int otherCount = otherLabel.forwardReferenceCount;
	if (otherCount == 0) return;
	// need to merge the two sorted arrays of forward references
	int[] mergedForwardReferences = new int[this.forwardReferenceCount + otherCount];
	int indexInMerge = 0;
	int j = 0;
	int i = 0;
	int max = this.forwardReferenceCount;
	int max2 = otherLabel.forwardReferenceCount;
	loop1 : for (; i < max; i++) {
	final int value1 = this.forwardReferences[i];
	for (; j < max2; j++) {
	final int value2 = otherLabel.forwardReferences[j];
	if (value1 < value2) {
	mergedForwardReferences[indexInMerge++] = value1;
	continue loop1;
	} else if (value1 == value2) {
	mergedForwardReferences[indexInMerge++] = value1;
	j++;
	continue loop1;
	} else {
	mergedForwardReferences[indexInMerge++] = value2;
	}
	}
	mergedForwardReferences[indexInMerge++] = value1;
	}
	for (; j < max2; j++) {
	mergedForwardReferences[indexInMerge++] = otherLabel.forwardReferences[j];
	}
	this.forwardReferences = mergedForwardReferences;
	this.forwardReferenceCount = indexInMerge;
	}

	/*
	* Put down a reference to the array at the location in the codestream.
	*/
	void branch() {
	this.tagBits \|= BranchLabel.USED;
	if (this.delegate != null) {
	this.delegate.branch();
	return;
	}
	if (this.position == Label.POS_NOT_SET) {
	addForwardReference(this.codeStream.position);
	// Leave two bytes free to generate the jump afterwards
	this.codeStream.position += 2;
	this.codeStream.classFileOffset += 2;
	} else {
	/*
	* Position is set. Write it if it is not a wide branch.
	*/
	this.codeStream.writePosition(this);
	}
	}

	/*
	* No support for wide branches yet
	*/
	void branchWide() {
	this.tagBits \|= BranchLabel.USED;
	if (this.delegate != null) {
	this.delegate.branchWide();
	return;
	}
	if (this.position == Label.POS_NOT_SET) {
	addForwardReference(this.codeStream.position);
	// Leave 4 bytes free to generate the jump offset afterwards
	this.tagBits \|= BranchLabel.WIDE;
	this.codeStream.position += 4;
	this.codeStream.classFileOffset += 4;
	} else { //Position is set. Write it!
	this.codeStream.writeWidePosition(this);
	}
	}

	public int forwardReferenceCount() {
	if (this.delegate != null) this.delegate.forwardReferenceCount();
	return this.forwardReferenceCount;
	}
	public int[] forwardReferences() {
	if (this.delegate != null) this.delegate.forwardReferences();
	return this.forwardReferences;
	}
	public void initialize(CodeStream stream) {
	this.codeStream = stream;
	this.position = Label.POS_NOT_SET;
	this.forwardReferenceCount = 0;
	this.delegate = null;
	}
	public boolean isCaseLabel() {
	return false;
	}
	public boolean isStandardLabel(){
	return true;
	}

	/*
	* Place the label. If we have forward references resolve them.
	*/
	public void place() { // Currently lacking wide support.
	// if ((this.tagBits & USED) == 0 && this.forwardReferenceCount == 0) {
	// return;
	// }

	//TODO how can position be set already ? cannot place more than once
	if (this.position == Label.POS_NOT_SET) {
	this.position = this.codeStream.position;
	this.codeStream.addLabel(this);
	int oldPosition = this.position;
	boolean isOptimizedBranch = false;
	if (this.forwardReferenceCount != 0) {
	isOptimizedBranch = (this.forwardReferences[this.forwardReferenceCount - 1] + 2 == this.position) && (this.codeStream.bCodeStream[this.codeStream.classFileOffset - 3] == Opcodes.OPC_goto);
	if (isOptimizedBranch) {
	if (this.codeStream.lastAbruptCompletion == this.position) {
	this.codeStream.lastAbruptCompletion = -1;
	}
	this.codeStream.position = (this.position -= 3);
	this.codeStream.classFileOffset -= 3;
	this.forwardReferenceCount--;
	if (this.codeStream.lastEntryPC == oldPosition) {
	this.codeStream.lastEntryPC = this.position;
	}
	// end of new code
	if ((this.codeStream.generateAttributes & (ClassFileConstants.ATTR_VARS \| ClassFileConstants.ATTR_STACK_MAP_TABLE \| ClassFileConstants.ATTR_STACK_MAP)) != 0) {
	LocalVariableBinding locals[] = this.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] = this.position;
	}
	if (local.initializationPCs[(local.initializationCount - 1) << 1] == oldPosition) {
	local.initializationPCs[(local.initializationCount - 1) << 1] = this.position;
	}
	}
	}
	}
	if ((this.codeStream.generateAttributes & ClassFileConstants.ATTR_LINES) != 0) {
	// we need to remove all entries that is beyond this.position inside the pcToSourcerMap table
	this.codeStream.removeUnusedPcToSourceMapEntries();
	}
	}
	}
	for (int i = 0; i < this.forwardReferenceCount; i++) {
	this.codeStream.writePosition(this, this.forwardReferences[i]);
	}
	// 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) {
	this.codeStream.optimizeBranch(oldPosition, this);
	}
	}
	}

	/**
	* 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(this.position); //$NON-NLS-1$
	if (this.delegate != null) buffer.append("delegate=").append(this.delegate); //$NON-NLS-1$
	buffer.append(", forwards = ["); //$NON-NLS-1$
	for (int i = 0; i < this.forwardReferenceCount - 1; i++)
	buffer.append(this.forwardReferences[i] + ", "); //$NON-NLS-1$
	if (this.forwardReferenceCount >= 1)
	buffer.append(this.forwardReferences[this.forwardReferenceCount-1]);
	buffer.append("] )"); //$NON-NLS-1$
	return buffer.toString();
	}
	}