X-Git-Url: http://git.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 index 824b721..7959ba7 100644 --- 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 @@ -1,112 +1,290 @@ +/******************************************************************************* + * Copyright (c) 2000, 2003 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 net.sourceforge.phpdt.internal.compiler.ast; -import java.util.List; +import net.sourceforge.phpdt.internal.compiler.ASTVisitor; +import net.sourceforge.phpdt.internal.compiler.flow.FlowContext; +import net.sourceforge.phpdt.internal.compiler.flow.FlowInfo; +import net.sourceforge.phpdt.internal.compiler.impl.Constant; +import net.sourceforge.phpdt.internal.compiler.lookup.BlockScope; +import net.sourceforge.phpdt.internal.compiler.lookup.TypeBinding; -/** - * This is a if statement. - * if (condition) - * statement - * (elseif statement)* - * else statement - * @author Matthieu Casanova - */ 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 statement; - public ElseIf[] elseifs; - public Else els; - - /** - * Create a new If statement. - * @param condition the condition - * @param statement a statement or a block of statements - * @param elseifs the elseifs - * @param els the else (or null) - * @param sourceStart the starting position - * @param sourceEnd the ending offset - */ - public IfStatement(final Expression condition, - final Statement statement, - final ElseIf[] elseifs, - final Else els, - final int sourceStart, - final int sourceEnd) { - super(sourceStart, sourceEnd); - this.condition = condition; - this.statement = statement; - this.elseifs = elseifs; - this.els = els; - } - - /** - * Return the object into String. - * @param tab how many tabs (not used here - * @return a String - */ - public String toString(final int tab) { - final StringBuffer buff = new StringBuffer(tabString(tab)); - buff.append("if (");//$NON-NLS-1$ - buff.append(condition.toStringExpression()).append(") ");//$NON-NLS-1$ - if (statement != null) { - buff.append(statement.toString(tab + 1)); - } - for (int i = 0; i < elseifs.length; i++) { - buff.append(elseifs[i].toString(tab + 1)); - buff.append("\n");//$NON-NLS-1$ - } - if (els != null) { - buff.append(els.toString(tab + 1)); - buff.append("\n");//$NON-NLS-1$ - } - return buff.toString(); - } - - /** - * Get the variables from outside (parameters, globals ...) - */ - public void getOutsideVariable(final List list) { - condition.getOutsideVariable(list); // todo: check if unuseful - if (statement != null) { - statement.getOutsideVariable(list); - } - for (int i = 0; i < elseifs.length; i++) { - elseifs[i].getOutsideVariable(list); - } - if (els != null) { - els.getOutsideVariable(list); - } - } - - /** - * get the modified variables. - */ - public void getModifiedVariable(final List list) { - condition.getModifiedVariable(list); - if (statement != null) { - statement.getModifiedVariable(list); - } - for (int i = 0; i < elseifs.length; i++) { - elseifs[i].getModifiedVariable(list); - } - if (els != null) { - els.getModifiedVariable(list); - } - } - - /** - * Get the variables used. - */ - public void getUsedVariable(final List list) { - condition.getUsedVariable(list); - if (statement != null) { - statement.getUsedVariable(list); - } - for (int i = 0; i < elseifs.length; i++) { - elseifs[i].getUsedVariable(list); - } - if (els != null) { - els.getUsedVariable(list); - } - } + public Expression condition; + public Statement thenStatement; + public Statement elseStatement; + public Expression[] elseifConditions; + public Statement[] elseifStatements; + public boolean checkUnreachable; + 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; + checkUnreachable = true; + } + + 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; + checkUnreachable = true; + } + + public FlowInfo analyseCode( + BlockScope currentScope, + FlowContext flowContext, + FlowInfo flowInfo) { + + // process the condition + flowInfo = condition.analyseCode(currentScope, flowContext, flowInfo); + + Constant cst = this.condition.optimizedBooleanConstant(); + boolean isConditionOptimizedTrue = cst != NotAConstant && cst.booleanValue() == true; + boolean isConditionOptimizedFalse = cst != NotAConstant && cst.booleanValue() == false; + + // process the THEN part + FlowInfo thenFlowInfo = flowInfo.initsWhenTrue().copy(); + if (isConditionOptimizedFalse) { + thenFlowInfo.setReachMode(FlowInfo.UNREACHABLE); + } + if (this.thenStatement != null) { + // Save info for code gen + thenInitStateIndex = + currentScope.methodScope().recordInitializationStates(thenFlowInfo); + if (!thenFlowInfo.complainIfUnreachable(thenStatement, currentScope, false)) { + thenFlowInfo = + thenStatement.analyseCode(currentScope, flowContext, thenFlowInfo); + } + }; + // optimizing the jump around the ELSE part + this.thenExit = !thenFlowInfo.isReachable(); + + // process the ELSE part + FlowInfo elseFlowInfo = flowInfo.initsWhenFalse().copy(); + if (isConditionOptimizedTrue) { + elseFlowInfo.setReachMode(FlowInfo.UNREACHABLE); + } + if (this.elseStatement != null) { + // Save info for code gen + elseInitStateIndex = + currentScope.methodScope().recordInitializationStates(elseFlowInfo); + if (!elseFlowInfo.complainIfUnreachable(elseStatement, currentScope, false)) { + elseFlowInfo = + elseStatement.analyseCode(currentScope, flowContext, elseFlowInfo); + } + } + + boolean elseExit = !elseFlowInfo.isReachable(); + + // merge THEN & ELSE initializations + FlowInfo mergedInfo; +// if (isConditionOptimizedTrue){ +// if (!this.thenExit) { +// mergedInfo = thenFlowInfo; +// } else { +// mergedInfo = elseFlowInfo.setReachMode(FlowInfo.UNREACHABLE); +// } +// +// } else if (isConditionOptimizedFalse) { +// if (!elseExit) { +// mergedInfo = elseFlowInfo; +// } else { +// mergedInfo = thenFlowInfo.setReachMode(FlowInfo.UNREACHABLE); +// } +// +// } else { +// mergedInfo = thenFlowInfo.mergedWith(elseFlowInfo.unconditionalInits()); +// } + if (isConditionOptimizedTrue){ + if (!this.thenExit) { + mergedInfo = thenFlowInfo.addPotentialInitializationsFrom(elseFlowInfo); + } else { + mergedInfo = elseFlowInfo.setReachMode(FlowInfo.UNREACHABLE); + } + + } else if (isConditionOptimizedFalse) { + if (!elseExit) { + mergedInfo = elseFlowInfo.addPotentialInitializationsFrom(thenFlowInfo); + } else { + mergedInfo = thenFlowInfo.setReachMode(FlowInfo.UNREACHABLE); + } + + } else { + mergedInfo = thenFlowInfo.mergedWith(elseFlowInfo.unconditionalInits()); + } + + mergedInitStateIndex = + currentScope.methodScope().recordInitializationStates(mergedInfo); + return mergedInfo; + } + + /** + * If code generation + * + * @param currentScope net.sourceforge.phpdt.internal.compiler.lookup.BlockScope + * @param codeStream net.sourceforge.phpdt.internal.compiler.codegen.CodeStream + */ +// public void generateCode(BlockScope currentScope, CodeStream codeStream) { +// +// if ((this.bits & IsReachableMASK) == 0) { +// return; +// } +// int pc = codeStream.position; +// Label endifLabel = new Label(codeStream); +// +// // optimizing the then/else part code gen +// Constant cst; +// boolean hasThenPart = +// !(((cst = this.condition.optimizedBooleanConstant()) != NotAConstant +// && cst.booleanValue() == false) +// || this.thenStatement == null +// || this.thenStatement.isEmptyBlock()); +// boolean hasElsePart = +// !((cst != NotAConstant && cst.booleanValue() == true) +// || this.elseStatement == null +// || this.elseStatement.isEmptyBlock()); +// +// if (hasThenPart) { +// Label falseLabel; +// // generate boolean condition +// this.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 +// this.thenStatement.generateCode(currentScope, codeStream); +// // jump around the else statement +// if (hasElsePart && !thenExit) { +// this.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 +// this.condition.generateOptimizedBoolean( +// currentScope, +// codeStream, +// endifLabel, +// null, +// true); +// } else { +// // generate condition side-effects +// this.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); +// } +// this.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 StringBuffer printStatement(int indent, StringBuffer output) { + + printIndent(indent, output).append("if ("); //$NON-NLS-1$ + condition.printExpression(0, output).append(")\n"); //$NON-NLS-1$ + thenStatement.printStatement(indent + 2, output); + if (elseStatement != null) { + output.append('\n'); + printIndent(indent, output); + output.append("else\n"); //$NON-NLS-1$ + elseStatement.printStatement(indent + 2, output); + } + return output; + } + 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( + ASTVisitor 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); + } }