+++ /dev/null
-/*******************************************************************************
- * Copyright (c) 2000, 2004 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 org.eclipse.jdt.internal.compiler.ast;
-
-import org.eclipse.jdt.internal.compiler.ASTVisitor;
-import org.eclipse.jdt.internal.compiler.classfmt.ClassFileConstants;
-import org.eclipse.jdt.internal.compiler.codegen.*;
-import org.eclipse.jdt.internal.compiler.flow.*;
-import org.eclipse.jdt.internal.compiler.impl.Constant;
-import org.eclipse.jdt.internal.compiler.lookup.*;
-
-public class ForStatement extends Statement {
-
- public Statement[] initializations;
- public Expression condition;
- public Statement[] increments;
- public Statement action;
-
- //when there is no local declaration, there is no need of a new scope
- //scope is positionned either to a new scope, or to the "upper"scope (see resolveType)
- public boolean neededScope;
- public BlockScope scope;
-
- private Label breakLabel, continueLabel;
-
- // for local variables table attributes
- int preCondInitStateIndex = -1;
- int condIfTrueInitStateIndex = -1;
- int mergedInitStateIndex = -1;
-
- public ForStatement(
- Statement[] initializations,
- Expression condition,
- Statement[] increments,
- Statement action,
- boolean neededScope,
- int s,
- int e) {
-
- this.sourceStart = s;
- this.sourceEnd = e;
- this.initializations = initializations;
- this.condition = condition;
- this.increments = increments;
- this.action = action;
- // remember useful empty statement
- if (action instanceof EmptyStatement) action.bits |= IsUsefulEmptyStatementMASK;
- this.neededScope = neededScope;
- }
-
- public FlowInfo analyseCode(
- BlockScope currentScope,
- FlowContext flowContext,
- FlowInfo flowInfo) {
-
- breakLabel = new Label();
- continueLabel = new Label();
-
- // process the initializations
- if (initializations != null) {
- for (int i = 0, count = initializations.length; i < count; i++) {
- flowInfo = initializations[i].analyseCode(scope, flowContext, flowInfo);
- }
- }
- preCondInitStateIndex =
- currentScope.methodScope().recordInitializationStates(flowInfo);
-
- Constant cst = this.condition == null ? null : this.condition.constant;
- boolean isConditionTrue = cst == null || (cst != NotAConstant && cst.booleanValue() == true);
- boolean isConditionFalse = cst != null && (cst != NotAConstant && cst.booleanValue() == false);
-
- cst = this.condition == null ? null : this.condition.optimizedBooleanConstant();
- boolean isConditionOptimizedTrue = cst == null || (cst != NotAConstant && cst.booleanValue() == true);
- boolean isConditionOptimizedFalse = cst != null && (cst != NotAConstant && cst.booleanValue() == false);
-
- // process the condition
- LoopingFlowContext condLoopContext = null;
- if (condition != null) {
- if (!isConditionTrue) {
- flowInfo =
- condition.analyseCode(
- scope,
- (condLoopContext =
- new LoopingFlowContext(flowContext, this, null, null, scope)),
- flowInfo);
- }
- }
-
- // process the action
- LoopingFlowContext loopingContext;
- FlowInfo actionInfo;
- if (action == null
- || (action.isEmptyBlock() && currentScope.environment().options.complianceLevel <= ClassFileConstants.JDK1_3)) {
- if (condLoopContext != null)
- condLoopContext.complainOnFinalAssignmentsInLoop(scope, flowInfo);
- if (isConditionTrue) {
- return FlowInfo.DEAD_END;
- } else {
- if (isConditionFalse){
- continueLabel = null; // for(;false;p());
- }
- actionInfo = flowInfo.initsWhenTrue().copy();
- loopingContext =
- new LoopingFlowContext(flowContext, this, breakLabel, continueLabel, scope);
- }
- } else {
- loopingContext =
- new LoopingFlowContext(flowContext, this, breakLabel, continueLabel, scope);
- FlowInfo initsWhenTrue = flowInfo.initsWhenTrue();
- condIfTrueInitStateIndex =
- currentScope.methodScope().recordInitializationStates(initsWhenTrue);
-
- if (isConditionFalse) {
- actionInfo = FlowInfo.DEAD_END;
- } else {
- actionInfo = initsWhenTrue.copy();
- if (isConditionOptimizedFalse){
- actionInfo.setReachMode(FlowInfo.UNREACHABLE);
- }
- }
- if (!this.action.complainIfUnreachable(actionInfo, scope, false)) {
- actionInfo = action.analyseCode(scope, loopingContext, actionInfo);
- }
-
- // code generation can be optimized when no need to continue in the loop
- if (!actionInfo.isReachable() && !loopingContext.initsOnContinue.isReachable()) {
- continueLabel = null;
- } else {
- if (condLoopContext != null)
- condLoopContext.complainOnFinalAssignmentsInLoop(scope, flowInfo);
- actionInfo = actionInfo.mergedWith(loopingContext.initsOnContinue.unconditionalInits());
- loopingContext.complainOnFinalAssignmentsInLoop(scope, actionInfo);
- }
- }
- // for increments
- if ((continueLabel != null) && (increments != null)) {
- LoopingFlowContext loopContext =
- new LoopingFlowContext(flowContext, this, null, null, scope);
- for (int i = 0, count = increments.length; i < count; i++) {
- actionInfo = increments[i].analyseCode(scope, loopContext, actionInfo);
- }
- loopContext.complainOnFinalAssignmentsInLoop(scope, actionInfo);
- }
-
- //end of loop
- FlowInfo mergedInfo = FlowInfo.mergedOptimizedBranches(
- loopingContext.initsOnBreak,
- isConditionOptimizedTrue,
- flowInfo.initsWhenFalse(),
- isConditionOptimizedFalse,
- !isConditionTrue /*for(;;){}while(true); unreachable(); */);
- mergedInitStateIndex = currentScope.methodScope().recordInitializationStates(mergedInfo);
- return mergedInfo;
- }
-
- /**
- * For statement 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;
-
- // generate the initializations
- if (initializations != null) {
- for (int i = 0, max = initializations.length; i < max; i++) {
- initializations[i].generateCode(scope, codeStream);
- }
- }
-
- // label management
- Label actionLabel = new Label(codeStream);
- Label conditionLabel = new Label(codeStream);
- breakLabel.initialize(codeStream);
- if (continueLabel != null) {
- continueLabel.initialize(codeStream);
- }
- // jump over the actionBlock
- if ((condition != null)
- && (condition.constant == NotAConstant)
- && !((action == null || action.isEmptyBlock()) && (increments == null))) {
- int jumpPC = codeStream.position;
- codeStream.goto_(conditionLabel);
- codeStream.recordPositionsFrom(jumpPC, condition.sourceStart);
- }
- // generate the loop action
- actionLabel.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(scope, codeStream);
- }
- // continuation point
- if (continueLabel != null) {
- continueLabel.place();
- // generate the increments for next iteration
- if (increments != null) {
- for (int i = 0, max = increments.length; i < max; i++) {
- increments[i].generateCode(scope, codeStream);
- }
- }
- }
-
- // May loose some local variable initializations : affecting the local variable attributes
- if (preCondInitStateIndex != -1) {
- codeStream.removeNotDefinitelyAssignedVariables(
- currentScope,
- preCondInitStateIndex);
- }
-
- // generate the condition
- conditionLabel.place();
- if ((condition != null) && (condition.constant == NotAConstant)) {
- condition.generateOptimizedBoolean(scope, codeStream, actionLabel, null, true);
- } else {
- if (continueLabel != null) {
- codeStream.goto_(actionLabel);
- }
- }
- breakLabel.place();
-
- // May loose some local variable initializations : affecting the local variable attributes
- if (neededScope) {
- codeStream.exitUserScope(scope);
- }
- if (mergedInitStateIndex != -1) {
- codeStream.removeNotDefinitelyAssignedVariables(currentScope, mergedInitStateIndex);
- codeStream.addDefinitelyAssignedVariables(currentScope, mergedInitStateIndex);
- }
- codeStream.recordPositionsFrom(pc, this.sourceStart);
- }
-
- public StringBuffer printStatement(int tab, StringBuffer output) {
-
- printIndent(tab, output).append("for ("); //$NON-NLS-1$
- //inits
- if (initializations != null) {
- for (int i = 0; i < initializations.length; i++) {
- //nice only with expressions
- if (i > 0) output.append(", "); //$NON-NLS-1$
- initializations[i].print(0, output);
- }
- }
- output.append("; "); //$NON-NLS-1$
- //cond
- if (condition != null) condition.printExpression(0, output);
- output.append("; "); //$NON-NLS-1$
- //updates
- if (increments != null) {
- for (int i = 0; i < increments.length; i++) {
- if (i > 0) output.append(", "); //$NON-NLS-1$
- increments[i].print(0, output);
- }
- }
- output.append(") "); //$NON-NLS-1$
- //block
- if (action == null)
- output.append(';');
- else {
- output.append('\n');
- action.printStatement(tab + 1, output); //$NON-NLS-1$
- }
- return output.append(';');
- }
-
- public void resolve(BlockScope upperScope) {
-
- // use the scope that will hold the init declarations
- scope = neededScope ? new BlockScope(upperScope) : upperScope;
- if (initializations != null)
- for (int i = 0, length = initializations.length; i < length; i++)
- initializations[i].resolve(scope);
- if (condition != null) {
- TypeBinding type = condition.resolveTypeExpecting(scope, BooleanBinding);
- condition.implicitWidening(type, type);
- }
- if (increments != null)
- for (int i = 0, length = increments.length; i < length; i++)
- increments[i].resolve(scope);
- if (action != null)
- action.resolve(scope);
- }
-
- public void traverse(
- ASTVisitor visitor,
- BlockScope blockScope) {
-
- if (visitor.visit(this, blockScope)) {
- if (initializations != null) {
- int initializationsLength = initializations.length;
- for (int i = 0; i < initializationsLength; i++)
- initializations[i].traverse(visitor, scope);
- }
-
- if (condition != null)
- condition.traverse(visitor, scope);
-
- if (increments != null) {
- int incrementsLength = increments.length;
- for (int i = 0; i < incrementsLength; i++)
- increments[i].traverse(visitor, scope);
- }
-
- if (action != null)
- action.traverse(visitor, scope);
- }
- visitor.endVisit(this, blockScope);
- }
-}
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