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Vaadin is a web application framework for Rich Internet Applications (RIA).
Vaadin enables easy development and maintenance of fast and
secure rich web
applications with a stunning look and feel and a wide browser support.
It features a server-side architecture with the majority of the logic
running
on the server. Ajax technology is used at the browser-side to ensure a
rich
and interactive user experience.
/*******************************************************************************
* Copyright (c) 2000, 2008 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-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.classfmt.ClassFileConstants;
import org.eclipse.jdt.internal.compiler.codegen.*;
import org.eclipse.jdt.internal.compiler.flow.*;
import org.eclipse.jdt.internal.compiler.impl.CompilerOptions;
import org.eclipse.jdt.internal.compiler.impl.Constant;
import org.eclipse.jdt.internal.compiler.lookup.*;
import org.eclipse.jdt.internal.compiler.problem.ProblemSeverities;
public class SwitchStatement extends Statement {
public Expression expression;
public Statement[] statements;
public BlockScope scope;
public int explicitDeclarations;
public BranchLabel breakLabel;
public CaseStatement[] cases;
public CaseStatement defaultCase;
public int blockStart;
public int caseCount;
int[] constants;
// fallthrough
public final static int CASE = 0;
public final static int FALLTHROUGH = 1;
public final static int ESCAPING = 2;
public SyntheticMethodBinding synthetic; // use for switch on enums types
// for local variables table attributes
int preSwitchInitStateIndex = -1;
int mergedInitStateIndex = -1;
public FlowInfo analyseCode(
BlockScope currentScope,
FlowContext flowContext,
FlowInfo flowInfo) {
try {
flowInfo = expression.analyseCode(currentScope, flowContext, flowInfo);
SwitchFlowContext switchContext =
new SwitchFlowContext(flowContext, this, (breakLabel = new BranchLabel()));
// analyse the block by considering specially the case/default statements (need to bind them
// to the entry point)
FlowInfo caseInits = FlowInfo.DEAD_END;
// in case of statements before the first case
preSwitchInitStateIndex =
currentScope.methodScope().recordInitializationStates(flowInfo);
int caseIndex = 0;
if (statements != null) {
boolean didAlreadyComplain = false;
int fallThroughState = CASE;
for (int i = 0, max = statements.length; i < max; i++) {
Statement statement = statements[i];
if ((caseIndex < caseCount) && (statement == cases[caseIndex])) { // statement is a case
this.scope.enclosingCase = cases[caseIndex]; // record entering in a switch case block
caseIndex++;
if (fallThroughState == FALLTHROUGH
&& (statement.bits & ASTNode.DocumentedFallthrough) == 0) { // the case is not fall-through protected by a line comment
scope.problemReporter().possibleFallThroughCase(this.scope.enclosingCase);
}
caseInits = caseInits.mergedWith(flowInfo.unconditionalInits());
didAlreadyComplain = false; // reset complaint
fallThroughState = CASE;
} else if (statement == defaultCase) { // statement is the default case
this.scope.enclosingCase = defaultCase; // record entering in a switch case block
if (fallThroughState == FALLTHROUGH
&& (statement.bits & ASTNode.DocumentedFallthrough) == 0) {
scope.problemReporter().possibleFallThroughCase(this.scope.enclosingCase);
}
caseInits = caseInits.mergedWith(flowInfo.unconditionalInits());
didAlreadyComplain = false; // reset complaint
fallThroughState = CASE;
} else {
fallThroughState = FALLTHROUGH; // reset below if needed
}
if (!statement.complainIfUnreachable(caseInits, scope, didAlreadyComplain)) {
caseInits = statement.analyseCode(scope, switchContext, caseInits);
if (caseInits == FlowInfo.DEAD_END) {
fallThroughState = ESCAPING;
}
} else {
didAlreadyComplain = true;
}
}
}
final TypeBinding resolvedTypeBinding = this.expression.resolvedType;
if (caseCount > 0 && resolvedTypeBinding.isEnum()) {
final SourceTypeBinding sourceTypeBinding = this.scope.classScope().referenceContext.binding;
this.synthetic = sourceTypeBinding.addSyntheticMethodForSwitchEnum(resolvedTypeBinding);
}
// if no default case, then record it may jump over the block directly to the end
if (defaultCase == null) {
// only retain the potential initializations
flowInfo.addPotentialInitializationsFrom(
caseInits.mergedWith(switchContext.initsOnBreak));
mergedInitStateIndex =
currentScope.methodScope().recordInitializationStates(flowInfo);
return flowInfo;
}
// merge all branches inits
FlowInfo mergedInfo = caseInits.mergedWith(switchContext.initsOnBreak);
mergedInitStateIndex =
currentScope.methodScope().recordInitializationStates(mergedInfo);
return mergedInfo;
} finally {
if (this.scope != null) this.scope.enclosingCase = null; // no longer inside switch case block
}
}
/**
* Switch 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) {
try {
if ((bits & IsReachable) == 0) {
return;
}
int pc = codeStream.position;
// prepare the labels and constants
this.breakLabel.initialize(codeStream);
CaseLabel[] caseLabels = new CaseLabel[this.caseCount];
boolean needSwitch = this.caseCount != 0;
for (int i = 0; i < caseCount; i++) {
cases[i].targetLabel = (caseLabels[i] = new CaseLabel(codeStream));
caseLabels[i].tagBits |= BranchLabel.USED;
}
CaseLabel defaultLabel = new CaseLabel(codeStream);
if (needSwitch) defaultLabel.tagBits |= BranchLabel.USED;
if (defaultCase != null) {
defaultCase.targetLabel = defaultLabel;
}
final TypeBinding resolvedType = this.expression.resolvedType;
if (resolvedType.isEnum()) {
if (needSwitch) {
// go through the translation table
codeStream.invokestatic(this.synthetic);
expression.generateCode(currentScope, codeStream, true);
// get enum constant ordinal()
codeStream.invokeEnumOrdinal(resolvedType.constantPoolName());
codeStream.iaload();
} else {
// no need to go through the translation table
expression.generateCode(currentScope, codeStream, false);
}
} else {
// generate expression
expression.generateCode(currentScope, codeStream, needSwitch); // value required (switch without cases)
}
// generate the appropriate switch table/lookup bytecode
if (needSwitch) {
int[] sortedIndexes = new int[this.caseCount];
// we sort the keys to be able to generate the code for tableswitch or lookupswitch
for (int i = 0; i < caseCount; i++) {
sortedIndexes[i] = i;
}
int[] localKeysCopy;
System.arraycopy(this.constants, 0, (localKeysCopy = new int[this.caseCount]), 0, this.caseCount);
CodeStream.sort(localKeysCopy, 0, this.caseCount - 1, sortedIndexes);
int max = localKeysCopy[this.caseCount - 1];
int min = localKeysCopy[0];
if ((long) (caseCount * 2.5) > ((long) max - (long) min)) {
// work-around 1.3 VM bug, if max>0x7FFF0000, must use lookup bytecode
// see http://dev.eclipse.org/bugs/show_bug.cgi?id=21557
if (max > 0x7FFF0000 && currentScope.compilerOptions().complianceLevel < ClassFileConstants.JDK1_4) {
codeStream.lookupswitch(defaultLabel, this.constants, sortedIndexes, caseLabels);
} else {
codeStream.tableswitch(
defaultLabel,
min,
max,
this.constants,
sortedIndexes,
caseLabels);
}
} else {
codeStream.lookupswitch(defaultLabel, this.constants, sortedIndexes, caseLabels);
}
codeStream.updateLastRecordedEndPC(this.scope, codeStream.position);
}
// generate the switch block statements
int caseIndex = 0;
if (this.statements != null) {
for (int i = 0, maxCases = this.statements.length; i < maxCases; i++) {
Statement statement = this.statements[i];
if ((caseIndex < this.caseCount) && (statement == this.cases[caseIndex])) { // statements[i] is a case
this.scope.enclosingCase = this.cases[caseIndex]; // record entering in a switch case block
if (preSwitchInitStateIndex != -1) {
codeStream.removeNotDefinitelyAssignedVariables(currentScope, preSwitchInitStateIndex);
}
caseIndex++;
} else {
if (statement == this.defaultCase) { // statements[i] is a case or a default case
this.scope.enclosingCase = this.defaultCase; // record entering in a switch case block
if (preSwitchInitStateIndex != -1) {
codeStream.removeNotDefinitelyAssignedVariables(currentScope, preSwitchInitStateIndex);
}
}
}
statement.generateCode(scope, codeStream);
}
}
// May loose some local variable initializations : affecting the local variable attributes
if (mergedInitStateIndex != -1) {
codeStream.removeNotDefinitelyAssignedVariables(currentScope, mergedInitStateIndex);
codeStream.addDefinitelyAssignedVariables(currentScope, mergedInitStateIndex);
}
if (scope != currentScope) {
codeStream.exitUserScope(this.scope);
}
// place the trailing labels (for break and default case)
this.breakLabel.place();
if (defaultCase == null) {
// we want to force an line number entry to get an end position after the switch statement
codeStream.recordPositionsFrom(codeStream.position, this.sourceEnd, true);
defaultLabel.place();
}
codeStream.recordPositionsFrom(pc, this.sourceStart);
} finally {
if (this.scope != null) this.scope.enclosingCase = null; // no longer inside switch case block
}
}
public StringBuffer printStatement(int indent, StringBuffer output) {
printIndent(indent, output).append("switch ("); //$NON-NLS-1$
expression.printExpression(0, output).append(") {"); //$NON-NLS-1$
if (statements != null) {
for (int i = 0; i < statements.length; i++) {
output.append('\n');
if (statements[i] instanceof CaseStatement) {
statements[i].printStatement(indent, output);
} else {
statements[i].printStatement(indent+2, output);
}
}
}
output.append("\n"); //$NON-NLS-1$
return printIndent(indent, output).append('}');
}
public void resolve(BlockScope upperScope) {
try {
boolean isEnumSwitch = false;
TypeBinding expressionType = expression.resolveType(upperScope);
if (expressionType != null) {
expression.computeConversion(upperScope, expressionType, expressionType);
checkType: {
if (!expressionType.isValidBinding()) {
expressionType = null; // fault-tolerance: ignore type mismatch from constants from hereon
break checkType;
} else if (expressionType.isBaseType()) {
if (expression.isConstantValueOfTypeAssignableToType(expressionType, TypeBinding.INT))
break checkType;
if (expressionType.isCompatibleWith(TypeBinding.INT))
break checkType;
} else if (expressionType.isEnum()) {
isEnumSwitch = true;
break checkType;
} else if (upperScope.isBoxingCompatibleWith(expressionType, TypeBinding.INT)) {
expression.computeConversion(upperScope, TypeBinding.INT, expressionType);
break checkType;
}
upperScope.problemReporter().incorrectSwitchType(expression, expressionType);
expressionType = null; // fault-tolerance: ignore type mismatch from constants from hereon
}
}
if (statements != null) {
scope = /*explicitDeclarations == 0 ? upperScope : */new BlockScope(upperScope);
int length;
// collection of cases is too big but we will only iterate until caseCount
cases = new CaseStatement[length = statements.length];
this.constants = new int[length];
CaseStatement[] duplicateCaseStatements = null;
int duplicateCaseStatementsCounter = 0;
int counter = 0;
for (int i = 0; i < length; i++) {
Constant constant;
final Statement statement = statements[i];
if ((constant = statement.resolveCase(scope, expressionType, this)) != Constant.NotAConstant) {
int key = constant.intValue();
//----check for duplicate case statement------------
for (int j = 0; j < counter; j++) {
if (this.constants[j] == key) {
final CaseStatement currentCaseStatement = (CaseStatement) statement;
if (duplicateCaseStatements == null) {
scope.problemReporter().duplicateCase(cases[j]);
scope.problemReporter().duplicateCase(currentCaseStatement);
duplicateCaseStatements = new CaseStatement[length];
duplicateCaseStatements[duplicateCaseStatementsCounter++] = cases[j];
duplicateCaseStatements[duplicateCaseStatementsCounter++] = currentCaseStatement;
} else {
boolean found = false;
searchReportedDuplicate: for (int k = 2; k < duplicateCaseStatementsCounter; k++) {
if (duplicateCaseStatements[k] == statement) {
found = true;
break searchReportedDuplicate;
}
}
if (!found) {
scope.problemReporter().duplicateCase(currentCaseStatement);
duplicateCaseStatements[duplicateCaseStatementsCounter++] = currentCaseStatement;
}
}
}
}
this.constants[counter++] = key;
}
}
if (length != counter) { // resize constants array
System.arraycopy(this.constants, 0, this.constants = new int[counter], 0, counter);
}
} else {
if ((this.bits & UndocumentedEmptyBlock) != 0) {
upperScope.problemReporter().undocumentedEmptyBlock(this.blockStart, this.sourceEnd);
}
}
// for enum switch, check if all constants are accounted for (if no default)
if (isEnumSwitch && defaultCase == null
&& upperScope.compilerOptions().getSeverity(CompilerOptions.IncompleteEnumSwitch) != ProblemSeverities.Ignore) {
int constantCount = this.constants == null ? 0 : this.constants.length; // could be null if no case statement
if (constantCount == caseCount // ignore diagnosis if unresolved constants
&& caseCount != ((ReferenceBinding)expressionType).enumConstantCount()) {
FieldBinding[] enumFields = ((ReferenceBinding)expressionType.erasure()).fields();
for (int i = 0, max = enumFields.length; i 0) {
label.becomeDelegateFor(this.breakLabel);
}
}
}