| 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.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); |
| } |
| } |