X-Git-Url: http://git.phpeclipse.com

diff --git a/net.sourceforge.phpeclipse/src/net/sourceforge/phpdt/internal/compiler/codegen/Label.java b/net.sourceforge.phpeclipse/src/net/sourceforge/phpdt/internal/compiler/codegen/Label.java
new file mode 100644
index 0000000..d75371e
--- /dev/null
+++ b/net.sourceforge.phpeclipse/src/net/sourceforge/phpdt/internal/compiler/codegen/Label.java
@@ -0,0 +1,246 @@
+/*******************************************************************************
+ * Copyright (c) 2000, 2001, 2002 International Business Machines Corp. and others.
+ * All rights reserved. This program and the accompanying materials 
+ * are made available under the terms of the Common Public License v0.5 
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/cpl-v05.html
+ * 
+ * Contributors:
+ *     IBM Corporation - initial API and implementation
+ ******************************************************************************/
+package net.sourceforge.phpdt.internal.compiler.codegen;
+
+import net.sourceforge.phpdt.internal.compiler.lookup.LocalVariableBinding;
+import net.sourceforge.phpdt.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() {
+}
+/**
+ * @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 refernece 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!
+		codeStream.writeSignedShort((short) (position - codeStream.position + 1));
+	}
+}
+/*
+* 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 boolean isStandardLabel(){
+	return true;
+}
+/*
+* Place the label. If we have forward references resolve them.
+*/
+public void place() { // Currently lacking wide support.
+	if (position == POS_NOT_SET) {
+		position = codeStream.position;
+		codeStream.addLabel(this);
+		int oldPosition = position;
+		boolean optimizedBranch = false;
+		// TURNED OFF since fail on 1F4IRD9
+		if (forwardReferenceCount != 0) {
+			if (optimizedBranch = (forwardReferences[forwardReferenceCount - 1] + 2 == position) && (codeStream.bCodeStream[codeStream.classFileOffset - 3] == CodeStream.OPC_goto)) {
+				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 (offset > 0x7FFF && !this.codeStream.wideMode) {
+				throw new AbortMethod(CodeStream.RESTART_IN_WIDE_MODE);
+			}
+			if (this.codeStream.wideMode) {
+				if (this.isWide) {
+					codeStream.writeSignedWord(forwardReferences[i], offset);
+				} else {
+					codeStream.writeSignedShort(forwardReferences[i], (short) offset);
+				}
+			} else {
+				codeStream.writeSignedShort(forwardReferences[i], (short) 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 (optimizedBranch) {
+			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 (offset > 0x7FFF && !this.codeStream.wideMode) {
+								throw new AbortMethod(CodeStream.RESTART_IN_WIDE_MODE);
+							}
+							if (this.codeStream.wideMode) {
+								if (this.isWide) {
+									codeStream.writeSignedWord(forwardPosition, offset);
+								} else {
+									codeStream.writeSignedShort(forwardPosition, (short) offset);
+								}
+							} else {
+								codeStream.writeSignedShort(forwardPosition, (short) offset);
+							}
+						}
+					}
+				}
+			}
+		}
+	}
+}
+/**
+ * Print out the receiver
+ */
+public String toString() {
+	StringBuffer buffer = new StringBuffer("(position="); //$NON-NLS-1$
+	buffer.append(position);
+	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();
+}
+
+public void resetStateForCodeGeneration() {
+	this.position = POS_NOT_SET;
+	this.forwardReferenceCount = 0;
+}
+}