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

diff --git a/net.sourceforge.phpeclipse/src/net/sourceforge/phpdt/internal/compiler/ast/IfStatement.java b/net.sourceforge.phpeclipse/src/net/sourceforge/phpdt/internal/compiler/ast/IfStatement.java
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+++ b/net.sourceforge.phpeclipse/src/net/sourceforge/phpdt/internal/compiler/ast/IfStatement.java
@@ -0,0 +1,278 @@
+/*******************************************************************************
+ * 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.ast;
+
+import net.sourceforge.phpdt.internal.compiler.IAbstractSyntaxTreeVisitor;
+import net.sourceforge.phpdt.internal.compiler.impl.*;
+import net.sourceforge.phpdt.internal.compiler.codegen.*;
+import net.sourceforge.phpdt.internal.compiler.flow.*;
+import net.sourceforge.phpdt.internal.compiler.lookup.*;
+
+public class IfStatement extends Statement {
+	
+	//this class represents the case of only one statement in 
+	//either else and/or then branches.
+
+	public Expression condition;
+	public Statement thenStatement;
+	public Statement elseStatement;
+
+	boolean thenExit;
+
+	// for local variables table attributes
+	int thenInitStateIndex = -1;
+	int elseInitStateIndex = -1;
+	int mergedInitStateIndex = -1;
+
+	public IfStatement(
+		Expression condition,
+		Statement thenStatement,
+		int s,
+		int e) {
+
+		this.condition = condition;
+		this.thenStatement = thenStatement;
+		sourceStart = s;
+		sourceEnd = e;
+	}
+
+	public IfStatement(
+		Expression condition,
+		Statement thenStatement,
+		Statement elseStatement,
+		int s,
+		int e) {
+
+		this.condition = condition;
+		this.thenStatement = thenStatement;
+		this.elseStatement = elseStatement;
+		sourceEnd = e;
+		sourceStart = s;
+	}
+
+	public FlowInfo analyseCode(
+		BlockScope currentScope,
+		FlowContext flowContext,
+		FlowInfo flowInfo) {
+
+		FlowInfo thenFlowInfo, elseFlowInfo;
+
+		// process the condition
+		flowInfo = condition.analyseCode(currentScope, flowContext, flowInfo);
+
+		// process the THEN part
+		if (thenStatement == null) {
+			thenFlowInfo = flowInfo.initsWhenTrue();
+		} else {
+			Constant cst;
+			thenFlowInfo =
+				((((cst = condition.constant) != NotAConstant)
+					&& (cst.booleanValue() == false))
+					|| (((cst = condition.conditionalConstant()) != NotAConstant)
+						&& (cst.booleanValue() == false)))
+					? (flowInfo.initsWhenTrue().copy().markAsFakeReachable(true))
+					: flowInfo.initsWhenTrue().copy();
+			// Save info for code gen
+			thenInitStateIndex =
+				currentScope.methodScope().recordInitializationStates(thenFlowInfo);
+			if (!thenFlowInfo.complainIfUnreachable(thenStatement, currentScope)) {
+				thenFlowInfo =
+					thenStatement.analyseCode(currentScope, flowContext, thenFlowInfo);
+			}
+		};
+		// optimizing the jump around the ELSE part
+		thenExit = (thenFlowInfo == FlowInfo.DeadEnd) || thenFlowInfo.isFakeReachable();
+
+		// process the ELSE part
+		if (elseStatement == null) {
+			elseFlowInfo = flowInfo.initsWhenFalse();
+		} else {
+			Constant cst;
+			elseFlowInfo =
+				((((cst = condition.constant) != NotAConstant) && (cst.booleanValue() == true))
+					|| (((cst = condition.conditionalConstant()) != NotAConstant)
+						&& (cst.booleanValue() == true)))
+					? (flowInfo.initsWhenFalse().copy().markAsFakeReachable(true))
+					: flowInfo.initsWhenFalse().copy();
+			// Save info for code gen
+			elseInitStateIndex =
+				currentScope.methodScope().recordInitializationStates(elseFlowInfo);
+			if (!elseFlowInfo.complainIfUnreachable(elseStatement, currentScope)) {
+				elseFlowInfo =
+					elseStatement.analyseCode(currentScope, flowContext, elseFlowInfo);
+			}
+		}
+
+		// merge THEN & ELSE initializations
+		FlowInfo mergedInfo;
+		if ((condition.constant != NotAConstant)
+			&& (condition.constant.booleanValue() == true)) {
+			// IF (TRUE)
+			if (thenExit) {
+				mergedInfo = elseFlowInfo.markAsFakeReachable(true);
+				mergedInitStateIndex =
+					currentScope.methodScope().recordInitializationStates(mergedInfo);
+				return mergedInfo;
+			} else {
+				mergedInitStateIndex =
+					currentScope.methodScope().recordInitializationStates(thenFlowInfo);
+				return thenFlowInfo;
+			}
+		} else {
+			// IF (FALSE)
+			if ((condition.constant != NotAConstant)
+				&& (condition.constant.booleanValue() == false)) {
+				if (elseFlowInfo.isDeadEnd()) {
+					mergedInfo = thenFlowInfo.markAsFakeReachable(true);
+					mergedInitStateIndex =
+						currentScope.methodScope().recordInitializationStates(mergedInfo);
+					return mergedInfo;
+				} else {
+					mergedInitStateIndex =
+						currentScope.methodScope().recordInitializationStates(elseFlowInfo);
+					return elseFlowInfo;
+				}
+			}
+		}
+		mergedInfo = thenFlowInfo.mergedWith(elseFlowInfo.unconditionalInits());
+		mergedInitStateIndex =
+			currentScope.methodScope().recordInitializationStates(mergedInfo);
+		return mergedInfo;
+	}
+
+	/**
+	 * If code generation
+	 *
+	 * @param currentScope org.eclipse.jdt.internal.compiler.lookup.BlockScope
+	 * @param codeStream org.eclipse.jdt.internal.compiler.codegen.CodeStream
+	 */
+	public void generateCode(BlockScope currentScope, CodeStream codeStream) {
+
+		if ((bits & IsReachableMASK) == 0) {
+			return;
+		}
+		int pc = codeStream.position;
+		Label endifLabel = new Label(codeStream);
+
+		// optimizing the then/else part code gen
+		Constant cst, condCst;
+		boolean hasThenPart =
+			!((((cst = condition.constant) != NotAConstant)
+				&& (cst.booleanValue() == false))
+				|| (thenStatement == null)
+				|| (thenStatement.isEmptyBlock())
+				|| (((condCst = condition.conditionalConstant()) != NotAConstant)
+					&& (condCst.booleanValue() == false)));
+		boolean hasElsePart =
+			!(((cst != NotAConstant) && (cst.booleanValue() == true))
+				|| (elseStatement == null)
+				|| (elseStatement.isEmptyBlock())
+				|| (((condCst = condition.conditionalConstant()) != NotAConstant)
+					&& (condCst.booleanValue() == true)));
+
+		if (hasThenPart) {
+			Label falseLabel;
+			// generate boolean condition
+			condition.generateOptimizedBoolean(
+				currentScope,
+				codeStream,
+				null,
+				(falseLabel = new Label(codeStream)),
+				true);
+			// May loose some local variable initializations : affecting the local variable attributes
+			if (thenInitStateIndex != -1) {
+				codeStream.removeNotDefinitelyAssignedVariables(
+					currentScope,
+					thenInitStateIndex);
+				codeStream.addDefinitelyAssignedVariables(currentScope, thenInitStateIndex);
+			}
+			// generate then statement
+			thenStatement.generateCode(currentScope, codeStream);
+			// jump around the else statement
+			if (hasElsePart && !thenExit) {
+				thenStatement.branchChainTo(endifLabel);
+				int position = codeStream.position;
+				codeStream.goto_(endifLabel);
+				codeStream.updateLastRecordedEndPC(position);
+				//goto is tagged as part of the thenAction block
+			}
+			falseLabel.place();
+		} else {
+			if (hasElsePart) {
+				// generate boolean condition
+				condition.generateOptimizedBoolean(
+					currentScope,
+					codeStream,
+					endifLabel,
+					null,
+					true);
+			} else {
+				// generate condition side-effects
+				condition.generateCode(currentScope, codeStream, false);
+				codeStream.recordPositionsFrom(pc, this.sourceStart);
+			}
+		}
+		// generate else statement
+		if (hasElsePart) {
+			// May loose some local variable initializations : affecting the local variable attributes
+			if (elseInitStateIndex != -1) {
+				codeStream.removeNotDefinitelyAssignedVariables(
+					currentScope,
+					elseInitStateIndex);
+				codeStream.addDefinitelyAssignedVariables(currentScope, elseInitStateIndex);
+			}
+			elseStatement.generateCode(currentScope, codeStream);
+		}
+		endifLabel.place();
+		// May loose some local variable initializations : affecting the local variable attributes
+		if (mergedInitStateIndex != -1) {
+			codeStream.removeNotDefinitelyAssignedVariables(
+				currentScope,
+				mergedInitStateIndex);
+		}
+		codeStream.recordPositionsFrom(pc, this.sourceStart);
+	}
+
+	public void resolve(BlockScope scope) {
+
+		TypeBinding type = condition.resolveTypeExpecting(scope, BooleanBinding);
+		condition.implicitWidening(type, type);
+		if (thenStatement != null)
+			thenStatement.resolve(scope);
+		if (elseStatement != null)
+			elseStatement.resolve(scope);
+	}
+
+	public String toString(int tab) {
+
+		String inFront, s = tabString(tab);
+		inFront = s;
+		s = s + "if (" + condition.toStringExpression() + ") \n";	//$NON-NLS-1$ //$NON-NLS-2$
+		s = s + thenStatement.toString(tab + 2) + ";"; //$NON-NLS-1$
+		if (elseStatement != null)
+			s = s + "\n" + inFront + "else\n" + elseStatement.toString(tab + 2) + ";"; //$NON-NLS-2$ //$NON-NLS-1$ //$NON-NLS-3$
+		return s;
+	}
+
+	public void traverse(
+		IAbstractSyntaxTreeVisitor visitor,
+		BlockScope blockScope) {
+
+		if (visitor.visit(this, blockScope)) {
+			condition.traverse(visitor, blockScope);
+			if (thenStatement != null)
+				thenStatement.traverse(visitor, blockScope);
+			if (elseStatement != null)
+				elseStatement.traverse(visitor, blockScope);
+		}
+		visitor.endVisit(this, blockScope);
+	}
+}
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