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package org.eclipse.jdt.internal.compiler.ast;
/*
* (c) Copyright IBM Corp. 2000, 2001.
* All Rights Reserved.
*/
import org.eclipse.jdt.internal.compiler.IAbstractSyntaxTreeVisitor;
import org.eclipse.jdt.internal.compiler.impl.*;
import org.eclipse.jdt.internal.compiler.codegen.*;
import org.eclipse.jdt.internal.compiler.flow.*;
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;
this.neededScope = neededScope;
}
public FlowInfo analyseCode(BlockScope currentScope, FlowContext flowContext, FlowInfo flowInfo) {
breakLabel = new Label();
continueLabel = new Label();
// process the initializations
if (initializations != null) {
int count = initializations.length, i = 0;
while (i < count) {
flowInfo = initializations[i++].analyseCode(scope, flowContext, flowInfo);
}
}
preCondInitStateIndex = currentScope.methodScope().recordInitializationStates(flowInfo);
// process the condition
LoopingFlowContext condLoopContext = null;
if (condition != null) {
if ((condition.constant == NotAConstant) || (condition.constant.booleanValue() != true)) {
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()) {
if (condLoopContext != null) condLoopContext.complainOnFinalAssignmentsInLoop(scope, flowInfo);
if ((condition == null) || ((condition.constant != NotAConstant) && (condition.constant.booleanValue() == true))) {
return FlowInfo.DeadEnd;
} else {
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);
actionInfo = action.analyseCode(
scope,
loopingContext,
((condition != null) && (condition.constant != NotAConstant) && (condition.constant.booleanValue() == false)) ? // unreachable when condition inlined to false
FlowInfo.DeadEnd :
initsWhenTrue.copy());
// 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 {
if (condLoopContext != null) condLoopContext.complainOnFinalAssignmentsInLoop(scope, flowInfo);
loopingContext.complainOnFinalAssignmentsInLoop(scope, actionInfo);
actionInfo = actionInfo.mergedWith(loopingContext.initsOnContinue.unconditionalInits()); // for increments
}
}
if ((continueLabel != null) && (increments != null)) {
LoopingFlowContext loopContext = new LoopingFlowContext(flowContext, this, null, null, scope);
int i = 0, count = increments.length;
while (i < count)
actionInfo = increments[i++].analyseCode(scope, loopContext, actionInfo);
loopContext.complainOnFinalAssignmentsInLoop(scope, flowInfo);
}
// infinite loop
FlowInfo mergedInfo;
if ((condition == null) || ((condition.constant != NotAConstant) && (condition.constant.booleanValue() == true))) {
mergedInitStateIndex = currentScope.methodScope().recordInitializationStates(mergedInfo = loopingContext.initsOnBreak);
return mergedInfo;
}
//end of loop: either condition false or break
mergedInfo = flowInfo.initsWhenFalse().unconditionalInits().mergedWith(loopingContext.initsOnBreak.unconditionalInits());
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.codeStream = codeStream;
if (continueLabel != null) {
continueLabel.codeStream = 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);
}
// 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.recordPositionsFrom(pc, this);
}
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 String toString(int tab ){
/* slow code */
String s = tabString(tab) + "for ("/*nonNLS*/;
if (!neededScope)
s = s + " //--NO upperscope scope needed\n"/*nonNLS*/ + tabString(tab) + " "/*nonNLS*/ ;
//inits
if (initializations != null)
{ for (int i = 0 ; i < initializations.length ; i++){
//nice only with expressions
s = s + initializations[i].toString(0);
if (i != (initializations.length -1)) s = s + " , "/*nonNLS*/ ;}};
s = s + "; "/*nonNLS*/ ;
//cond
if (condition != null)
s = s + condition.toStringExpression() ;
s = s + "; "/*nonNLS*/ ;
//updates
if (increments != null)
{ for (int i = 0 ; i < increments.length ; i++){
//nice only with expressions
s = s + increments[i].toString(0);
if (i != (increments.length -1)) s = s + " , "/*nonNLS*/ ;}};
s = s + ") "/*nonNLS*/ ;
//block
if (action == null)
s = s + "{}"/*nonNLS*/ ;
else
s = s + "\n"/*nonNLS*/+ action.toString(tab+1) ;
return s;}
public void traverse(IAbstractSyntaxTreeVisitor 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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