+++ /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.impl.*;
-import org.eclipse.jdt.internal.compiler.codegen.*;
-import org.eclipse.jdt.internal.compiler.flow.*;
-import org.eclipse.jdt.internal.compiler.lookup.*;
-
-public class DoStatement extends Statement {
-
- public Expression condition;
- public Statement action;
-
- private Label breakLabel, continueLabel;
-
- // for local variables table attributes
- int mergedInitStateIndex = -1;
-
- public DoStatement(Expression condition, Statement action, int s, int e) {
-
- this.sourceStart = s;
- this.sourceEnd = e;
- this.condition = condition;
- this.action = action;
- // remember useful empty statement
- if (action instanceof EmptyStatement) action.bits |= IsUsefulEmptyStatementMASK;
- }
-
- public FlowInfo analyseCode(
- BlockScope currentScope,
- FlowContext flowContext,
- FlowInfo flowInfo) {
-
- breakLabel = new Label();
- continueLabel = new Label();
- LoopingFlowContext loopingContext =
- new LoopingFlowContext(
- flowContext,
- this,
- breakLabel,
- continueLabel,
- currentScope);
-
- Constant cst = condition.constant;
- boolean isConditionTrue = cst != NotAConstant && cst.booleanValue() == true;
- cst = condition.optimizedBooleanConstant();
- boolean isConditionOptimizedTrue = cst != NotAConstant && cst.booleanValue() == true;
- boolean isConditionOptimizedFalse = cst != NotAConstant && cst.booleanValue() == false;
-
- int previousMode = flowInfo.reachMode();
-
- if ((action != null) && !action.isEmptyBlock()) {
- flowInfo = action.analyseCode(currentScope, loopingContext, flowInfo);
-
- // code generation can be optimized when no need to continue in the loop
- if (!flowInfo.isReachable() && !loopingContext.initsOnContinue.isReachable()) {
- continueLabel = null;
- }
- }
- /* Reset reach mode, to address following scenario.
- * final blank;
- * do { if (true) break; else blank = 0; } while(false);
- * blank = 1; // may be initialized already
- */
- flowInfo.setReachMode(previousMode);
-
- flowInfo =
- condition.analyseCode(
- currentScope,
- loopingContext,
- (action == null
- ? flowInfo
- : (flowInfo.mergedWith(loopingContext.initsOnContinue))));
- if (!isConditionOptimizedFalse && continueLabel != null) {
- loopingContext.complainOnFinalAssignmentsInLoop(currentScope, flowInfo);
- }
-
- // end of loop
- FlowInfo mergedInfo = FlowInfo.mergedOptimizedBranches(
- loopingContext.initsOnBreak,
- isConditionOptimizedTrue,
- flowInfo.initsWhenFalse(),
- false, // never consider opt false case for DO loop, since break can always occur (47776)
- !isConditionTrue /*do{}while(true); unreachable(); */);
- mergedInitStateIndex = currentScope.methodScope().recordInitializationStates(mergedInfo);
- return mergedInfo;
- }
-
- /**
- * Do statement code generation
- *
- */
- public void generateCode(BlockScope currentScope, CodeStream codeStream) {
-
- if ((bits & IsReachableMASK) == 0) {
- return;
- }
- int pc = codeStream.position;
-
- // labels management
- Label actionLabel = new Label(codeStream);
- actionLabel.place();
- breakLabel.initialize(codeStream);
- if (continueLabel != null) {
- continueLabel.initialize(codeStream);
- }
-
- // generate action
- if (action != null) {
- action.generateCode(currentScope, codeStream);
- }
- // generate condition
- 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.addDefinitelyAssignedVariables(currentScope, mergedInitStateIndex);
- }
- codeStream.recordPositionsFrom(pc, this.sourceStart);
-
- }
-
- public StringBuffer printStatement(int indent, StringBuffer output) {
-
- printIndent(indent, output).append("do"); //$NON-NLS-1$
- if (action == null)
- output.append(" ;\n"); //$NON-NLS-1$
- else {
- output.append('\n');
- action.printStatement(indent + 1, output).append('\n');
- }
- output.append("while ("); //$NON-NLS-1$
- return condition.printExpression(0, output).append(");"); //$NON-NLS-1$
- }
- public void resolve(BlockScope scope) {
-
- TypeBinding type = condition.resolveTypeExpecting(scope, BooleanBinding);
- condition.implicitWidening(type, type);
- if (action != null)
- action.resolve(scope);
- }
-
- public void traverse(ASTVisitor visitor, BlockScope scope) {
-
- if (visitor.visit(this, scope)) {
- if (action != null) {
- action.traverse(visitor, scope);
- }
- condition.traverse(visitor, scope);
- }
- visitor.endVisit(this, scope);
- }
-}
projects / org.ibex.tool.git / blobdiff