+/*******************************************************************************
+ * Copyright (c) 2000, 2003 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 net.sourceforge.phpdt.internal.compiler.ast;
-import java.util.List;
-import java.util.ArrayList;
+import net.sourceforge.phpdt.internal.compiler.ASTVisitor;
+import net.sourceforge.phpdt.internal.compiler.codegen.Label;
+import net.sourceforge.phpdt.internal.compiler.flow.FlowContext;
+import net.sourceforge.phpdt.internal.compiler.flow.FlowInfo;
+import net.sourceforge.phpdt.internal.compiler.flow.LoopingFlowContext;
+import net.sourceforge.phpdt.internal.compiler.impl.Constant;
+import net.sourceforge.phpdt.internal.compiler.lookup.BlockScope;
+import net.sourceforge.phpdt.internal.compiler.lookup.TypeBinding;
-/**
- * A do statement.
- * @author Matthieu Casanova
- */
public class DoStatement extends Statement {
+ public Expression condition;
- /** The condition expression. */
- public Expression condition;
- /** The action of the while. (it could be a block) */
- public Statement action;
-
- public DoStatement(final Expression condition,
- final Statement action,
- final int sourceStart,
- final int sourceEnd) {
- super(sourceStart, sourceEnd);
- this.condition = condition;
- this.action = action;
- }
-
- /**
- * Return the object into String.
- * @param tab how many tabs (not used here
- * @return a String
- */
- public String toString(final int tab) {
- final String s = tabString(tab);
- final StringBuffer buff = new StringBuffer("do ");//$NON-NLS-1$
- if (action == null) {
- buff.append(" {} ;"); //$NON-NLS-1$
- } else {
- buff.append("\n").append(action.toString(tab + 1));//$NON-NLS-1$
- }
- buff.append(s).append(" while (");//$NON-NLS-1$
- buff.append(condition.toStringExpression()).append(")");//$NON-NLS-1$
- return buff.toString();
- }
-
- /**
- * Get the variables from outside (parameters, globals ...)
- */
- public void getOutsideVariable(final List list) {
- condition.getOutsideVariable(list); // todo: check if unuseful
- action.getOutsideVariable(list);
- }
-
- /**
- * get the modified variables.
- */
- public void getModifiedVariable(final List list) {
- condition.getModifiedVariable(list);
- action.getModifiedVariable(list);
- }
-
- /**
- * Get the variables used.
- */
- public void getUsedVariable(final List list) {
- condition.getUsedVariable(list);
- action.getUsedVariable(list);
- }
+ 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;
+ }
+
+ 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);
+ }
+
+ // infinite loop
+ FlowInfo mergedInfo;
+ if (isConditionTrue) {
+ mergedInfo = loopingContext.initsOnBreak;
+ if (!mergedInfo.isReachable())
+ mergedInfo.addPotentialInitializationsFrom(flowInfo
+ .initsWhenFalse());
+ } else {
+ // end of loop: either condition false or break
+ mergedInfo = flowInfo.initsWhenFalse().unconditionalInits()
+ .mergedWith(loopingContext.initsOnBreak);
+ if (isConditionOptimizedTrue
+ && !loopingContext.initsOnBreak.isReachable()) {
+ mergedInfo.setReachMode(FlowInfo.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.codeStream = codeStream;
+ // if (continueLabel != null) {
+ // continueLabel.codeStream = 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.recordPositionsFrom(pc, this.sourceStart);
+ //
+ // }
+ public void resetStateForCodeGeneration() {
+ if (this.breakLabel != null) {
+ this.breakLabel.resetStateForCodeGeneration();
+ }
+ if (this.continueLabel != null) {
+ this.continueLabel.resetStateForCodeGeneration();
+ }
+ }
+
+ public void resolve(BlockScope scope) {
+
+ TypeBinding type = condition
+ .resolveTypeExpecting(scope, BooleanBinding);
+ condition.implicitWidening(type, type);
+ if (action != null)
+ action.resolve(scope);
+ }
+
+ 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 String toString(int tab) {
+
+ String inFront, s = tabString(tab);
+ inFront = s;
+ s = s + "do"; //$NON-NLS-1$
+ if (action == null)
+ s = s + " {}\n"; //$NON-NLS-1$
+ else if (action instanceof Block)
+ s = s + "\n" + action.toString(tab + 1) + "\n"; //$NON-NLS-2$ //$NON-NLS-1$
+ else
+ s = s + " {\n" + action.toString(tab + 1) + ";}\n"; //$NON-NLS-1$ //$NON-NLS-2$
+ s = s + inFront + "while (" + condition.toStringExpression() + ")"; //$NON-NLS-1$ //$NON-NLS-2$
+ return s;
+ }
+
+ 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);
+ }
}
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