--- /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);
+ }
+}