| /******************************************************************************* |
| * 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 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 Label breakLabel; |
| public CaseStatement[] cases; |
| public CaseStatement defaultCase; |
| public int blockStart; |
| public int caseCount; |
| int[] constants; |
| |
| // 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 Label())); |
| |
| // 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; |
| 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++; |
| caseInits = caseInits.mergedWith(flowInfo.copy().unconditionalInits()); |
| didAlreadyComplain = false; // reset complaint |
| } else if (statement == defaultCase) { // statement is the default case |
| this.scope.enclosingCase = defaultCase; // record entering in a switch case block |
| caseInits = caseInits.mergedWith(flowInfo.copy().unconditionalInits()); |
| didAlreadyComplain = false; // reset complaint |
| } |
| if (!statement.complainIfUnreachable(caseInits, scope, didAlreadyComplain)) { |
| caseInits = statement.analyseCode(scope, switchContext, caseInits); |
| } else { |
| didAlreadyComplain = true; |
| } |
| } |
| } |
| |
| // 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 & IsReachableMASK) == 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)); |
| } |
| CaseLabel defaultLabel = new CaseLabel(codeStream); |
| if (defaultCase != null) { |
| defaultCase.targetLabel = defaultLabel; |
| } |
| // generate expression testes |
| expression.generateCode(currentScope, codeStream, needSwitch); |
| // 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); |
| |
| // for enum constants, actually switch on constant ordinal() |
| if (this.expression.resolvedType.isEnum()) { |
| codeStream.invokeEnumOrdinal(this.expression.resolvedType.constantPoolName()); |
| } |
| 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.environment().options.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); |
| } |
| } |
| // place the trailing labels (for break and default case) |
| this.breakLabel.place(); |
| if (defaultCase == null) { |
| defaultLabel.place(); |
| } |
| // 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); |
| } |
| 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) |
| return; |
| expression.computeConversion(upperScope, expressionType, expressionType); |
| checkType: { |
| if (expressionType.isBaseType()) { |
| if (expression.isConstantValueOfTypeAssignableToType(expressionType, IntBinding)) |
| break checkType; |
| if (expressionType.isCompatibleWith(IntBinding)) |
| break checkType; |
| } else if (expressionType.isEnum()) { |
| isEnumSwitch = true; |
| break checkType; |
| } else if (upperScope.isBoxingCompatibleWith(expressionType, IntBinding)) { |
| expression.computeConversion(upperScope, IntBinding, expressionType); |
| break checkType; |
| } |
| upperScope.problemReporter().incorrectSwitchType(expression, expressionType); |
| // TODO (philippe) could keep analyzing switch statements in case of error |
| return; |
| } |
| 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 & UndocumentedEmptyBlockMASK) != 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.environment().options.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 <max; i++) { |
| FieldBinding enumConstant = enumFields[i]; |
| if ((enumConstant.modifiers & AccEnum) == 0) continue; |
| findConstant : { |
| for (int j = 0; j < caseCount; j++) { |
| if (enumConstant.id == this.constants[j]) break findConstant; |
| } |
| // enum constant did not get referenced from switch |
| upperScope.problemReporter().missingEnumConstantCase(this, enumConstant); |
| } |
| } |
| } |
| } |
| } finally { |
| if (this.scope != null) this.scope.enclosingCase = null; // no longer inside switch case block |
| } |
| } |
| |
| public void traverse( |
| ASTVisitor visitor, |
| BlockScope blockScope) { |
| |
| if (visitor.visit(this, blockScope)) { |
| expression.traverse(visitor, scope); |
| if (statements != null) { |
| int statementsLength = statements.length; |
| for (int i = 0; i < statementsLength; i++) |
| statements[i].traverse(visitor, scope); |
| } |
| } |
| visitor.endVisit(this, blockScope); |
| } |
| |
| /** |
| * Dispatch the call on its last statement. |
| */ |
| public void branchChainTo(Label label) { |
| |
| // in order to improve debug attributes for stepping (11431) |
| // we want to inline the jumps to #breakLabel which already got |
| // generated (if any), and have them directly branch to a better |
| // location (the argument label). |
| // we know at this point that the breakLabel already got placed |
| if (this.breakLabel.hasForwardReferences()) { |
| label.appendForwardReferencesFrom(this.breakLabel); |
| } |
| } |
| } |
