+++ /dev/null
-/*******************************************************************************
- * 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.codegen.CodeStream;
-import net.sourceforge.phpdt.internal.compiler.codegen.Label;
-import net.sourceforge.phpdt.internal.compiler.flow.FlowContext;
-import net.sourceforge.phpdt.internal.compiler.flow.FlowInfo;
-import net.sourceforge.phpdt.internal.compiler.flow.LoopingFlowContext;
-import net.sourceforge.phpdt.internal.compiler.impl.Constant;
-import net.sourceforge.phpdt.internal.compiler.lookup.BlockScope;
-import net.sourceforge.phpdt.internal.compiler.lookup.TypeBinding;
-
-public class WhileStatement extends Statement {
-
- public Expression condition;
- public Statement action;
- private Label breakLabel, continueLabel;
- int preCondInitStateIndex = -1;
- int condIfTrueInitStateIndex = -1;
- int mergedInitStateIndex = -1;
-
- public WhileStatement(Expression condition, Statement action, int s, int e) {
-
- this.condition = condition;
- this.action = action;
- sourceStart = s;
- sourceEnd = e;
- }
-
- public FlowInfo analyseCode(
- BlockScope currentScope,
- FlowContext flowContext,
- FlowInfo flowInfo) {
-
- breakLabel = new Label();
- continueLabel = new Label();
-
- preCondInitStateIndex =
- currentScope.methodScope().recordInitializationStates(flowInfo);
- LoopingFlowContext condLoopContext;
- FlowInfo postCondInfo =
- condition.analyseCode(
- currentScope,
- (condLoopContext =
- new LoopingFlowContext(flowContext, this, null, null, currentScope)),
- flowInfo);
-
- LoopingFlowContext loopingContext;
- if ((action == null) || action.isEmptyBlock()) {
- condLoopContext.complainOnFinalAssignmentsInLoop(currentScope, postCondInfo);
- if ((condition.constant != NotAConstant)
- && (condition.constant.booleanValue() == true)) {
- return FlowInfo.DeadEnd;
- } else {
- FlowInfo mergedInfo = postCondInfo.initsWhenFalse().unconditionalInits();
- mergedInitStateIndex =
- currentScope.methodScope().recordInitializationStates(mergedInfo);
- return mergedInfo;
- }
- } else {
- // in case the condition was inlined to false, record the fact that there is no way to reach any
- // statement inside the looping action
- loopingContext =
- new LoopingFlowContext(
- flowContext,
- this,
- breakLabel,
- continueLabel,
- currentScope);
- FlowInfo actionInfo =
- ((condition.constant != Constant.NotAConstant)
- && (condition.constant.booleanValue() == false))
- ? FlowInfo.DeadEnd
- : postCondInfo.initsWhenTrue().copy();
-
- // for computing local var attributes
- condIfTrueInitStateIndex =
- currentScope.methodScope().recordInitializationStates(
- postCondInfo.initsWhenTrue());
-
- if (!actionInfo.complainIfUnreachable(action, currentScope)) {
- actionInfo = action.analyseCode(currentScope, loopingContext, actionInfo);
- }
-
- // code generation can be optimized when no need to continue in the loop
- if (((actionInfo == FlowInfo.DeadEnd) || actionInfo.isFakeReachable())
- && ((loopingContext.initsOnContinue == FlowInfo.DeadEnd)
- || loopingContext.initsOnContinue.isFakeReachable())) {
- continueLabel = null;
- } else {
- condLoopContext.complainOnFinalAssignmentsInLoop(currentScope, postCondInfo);
- loopingContext.complainOnFinalAssignmentsInLoop(currentScope, actionInfo);
- }
- }
-
- // infinite loop
- FlowInfo mergedInfo;
- if ((condition.constant != Constant.NotAConstant)
- && (condition.constant.booleanValue() == true)) {
- mergedInitStateIndex =
- currentScope.methodScope().recordInitializationStates(
- mergedInfo = loopingContext.initsOnBreak);
- return mergedInfo;
- }
-
- // end of loop: either condition false or break
- mergedInfo =
- postCondInfo.initsWhenFalse().unconditionalInits().mergedWith(
- loopingContext.initsOnBreak);
- mergedInitStateIndex =
- currentScope.methodScope().recordInitializationStates(mergedInfo);
- return mergedInfo;
- }
-
- /**
- * While 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;
- breakLabel.codeStream = codeStream;
-
- // generate condition
- if (continueLabel == null) {
- // no need to reverse condition
- if (condition.constant == NotAConstant) {
- condition.generateOptimizedBoolean(
- currentScope,
- codeStream,
- null,
- breakLabel,
- true);
- }
- } else {
- continueLabel.codeStream = codeStream;
- if (!(((condition.constant != NotAConstant)
- && (condition.constant.booleanValue() == true))
- || (action == null)
- || action.isEmptyBlock())) {
- int jumpPC = codeStream.position;
- codeStream.goto_(continueLabel);
- codeStream.recordPositionsFrom(jumpPC, condition.sourceStart);
- }
- }
- // generate the action
- Label actionLabel;
- (actionLabel = new Label(codeStream)).place();
- if (action != null) {
- // Required to fix 1PR0XVS: LFRE:WINNT - Compiler: variable table for method appears incorrect
- if (condIfTrueInitStateIndex != -1) {
- // insert all locals initialized inside the condition into the action generated prior to the condition
- codeStream.addDefinitelyAssignedVariables(
- currentScope,
- condIfTrueInitStateIndex);
- }
- action.generateCode(currentScope, codeStream);
- // May loose some local variable initializations : affecting the local variable attributes
- if (preCondInitStateIndex != -1) {
- codeStream.removeNotDefinitelyAssignedVariables(
- currentScope,
- preCondInitStateIndex);
- }
-
- }
- // output condition and branch back to the beginning of the repeated action
- if (continueLabel != null) {
- continueLabel.place();
- condition.generateOptimizedBoolean(
- currentScope,
- codeStream,
- actionLabel,
- null,
- true);
- }
- breakLabel.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 resetStateForCodeGeneration() {
-
- this.breakLabel.resetStateForCodeGeneration();
- this.continueLabel.resetStateForCodeGeneration();
- }
-
- public void resolve(BlockScope scope) {
-
- TypeBinding type = condition.resolveTypeExpecting(scope, BooleanBinding);
- condition.implicitWidening(type, type);
- if (action != null)
- action.resolve(scope);
- }
-
- public String toString(int tab) {
-
- String s = tabString(tab);
- s = s + "while (" + condition.toStringExpression() + ")"; //$NON-NLS-1$ //$NON-NLS-2$
- if (action == null)
- s = s + " {} ;"; //$NON-NLS-1$
- else if (action instanceof Block)
- s = s + "\n" + action.toString(tab + 1); //$NON-NLS-1$
- else
- s = s + " {\n" + action.toString(tab + 1) + "}"; //$NON-NLS-2$ //$NON-NLS-1$
- return s;
- }
-
- public void traverse(
- IAbstractSyntaxTreeVisitor visitor,
- BlockScope blockScope) {
-
- if (visitor.visit(this, blockScope)) {
- condition.traverse(visitor, blockScope);
- if (action != null)
- action.traverse(visitor, blockScope);
- }
- visitor.endVisit(this, blockScope);
- }
-}
\ No newline at end of file
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