+/*******************************************************************************
+ * 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.SwitchFlowContext;
+import net.sourceforge.phpdt.internal.compiler.impl.Constant;
+import net.sourceforge.phpdt.internal.compiler.lookup.BlockScope;
+import net.sourceforge.phpdt.internal.compiler.lookup.TypeBinding;
-/**
- * @author Matthieu Casanova
- */
public class SwitchStatement extends Statement {
+ public Expression expression;
+ public Statement[] statements;
+ public BlockScope scope;
+ public int explicitDeclarations;
+ public Label breakLabel;
+ public CaseStatement[] cases;
+ public DefaultCase defaultCase;
+ public int caseCount = 0;
- public Expression variable;
- public AbstractCase[] cases;
+ // for local variables table attributes
+ int preSwitchInitStateIndex = -1;
+ int mergedInitStateIndex = -1;
+ /**
+ * SwitchStatement constructor comment.
+ */
+ public SwitchStatement() {
+ super();
+ }
+ public FlowInfo analyseCode(
+ BlockScope currentScope,
+ FlowContext flowContext,
+ FlowInfo flowInfo) {
+ flowInfo = expression.analyseCode(currentScope, flowContext, flowInfo);
+ SwitchFlowContext switchContext =
+ new SwitchFlowContext(flowContext, this, (breakLabel = new Label()));
- public SwitchStatement(final Expression variable,
- final AbstractCase[] cases,
- final int sourceStart,
- final int sourceEnd) {
- super(sourceStart, sourceEnd);
- this.variable = variable;
- this.cases = cases;
- }
+ // 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
+ caseIndex++;
+ caseInits = caseInits.mergedWith(flowInfo.copy().unconditionalInits());
+ didAlreadyComplain = false; // reset complaint
+ } else if (statement == defaultCase) { // statement is the default case
+ caseInits = caseInits.mergedWith(flowInfo.copy().unconditionalInits());
+ didAlreadyComplain = false; // reset complaint
+ }
+ if (!caseInits.complainIfUnreachable(statement, scope, didAlreadyComplain)) {
+ caseInits = statement.analyseCode(scope, switchContext, caseInits);
+ } else {
+ didAlreadyComplain = true;
+ }
+ }
+ }
- /**
- * Return the object into String.
- * @param tab how many tabs (not used here
- * @return a String
- */
- public String toString(final int tab) {
- final StringBuffer buff = new StringBuffer(tabString(tab));
- buff.append("switch (").append(variable.toStringExpression()).append(") {\n");
- for (int i = 0; i < cases.length; i++) {
- final AbstractCase cas = cases[i];
- buff.append(cas.toString(tab + 1));
- buff.append('\n');
- }
- buff.append('}');
- return buff.toString();
- }
+ // 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;
+ }
- /**
- * Get the variables from outside (parameters, globals ...)
- */
- public void getOutsideVariable(final List list) {
- for (int i = 0; i < cases.length; i++) {
- cases[i].getOutsideVariable(list);
- }
- }
+ // merge all branches inits
+ FlowInfo mergedInfo = caseInits.mergedWith(switchContext.initsOnBreak);
+ mergedInitStateIndex =
+ currentScope.methodScope().recordInitializationStates(mergedInfo);
+ return mergedInfo;
+ }
+ /**
+ * Switch code generation
+ *
+ * @param currentScope net.sourceforge.phpdt.internal.compiler.lookup.BlockScope
+ * @param codeStream net.sourceforge.phpdt.internal.compiler.codegen.CodeStream
+ */
+// public void generateCode(BlockScope currentScope, CodeStream codeStream) {
+// int[] sortedIndexes = new int[caseCount];
+// int[] localKeysCopy;
+// if ((bits & IsReachableMASK) == 0) {
+// return;
+// }
+// int pc = codeStream.position;
+//
+// // prepare the labels and constants
+// breakLabel.codeStream = codeStream;
+// CaseLabel[] caseLabels = new CaseLabel[caseCount];
+// int[] constants = new int[caseCount];
+// boolean needSwitch = caseCount != 0;
+// for (int i = 0; i < caseCount; i++) {
+// constants[i] = cases[i].constantExpression.constant.intValue();
+// cases[i].targetLabel = (caseLabels[i] = new CaseLabel(codeStream));
+// }
+//
+// // 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;
+// }
+// System.arraycopy(
+// constants,
+// 0,
+// (localKeysCopy = new int[caseCount]),
+// 0,
+// caseCount);
+// CodeStream.sort(localKeysCopy, 0, caseCount - 1, sortedIndexes);
+// CaseLabel defaultLabel = new CaseLabel(codeStream);
+// if (defaultCase != null) {
+// defaultCase.targetLabel = defaultLabel;
+// }
+// // generate expression testes
+// testExpression.generateCode(currentScope, codeStream, needSwitch);
+//
+// // generate the appropriate switch table/lookup bytecode
+// if (needSwitch) {
+// int max = localKeysCopy[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 < CompilerOptions.JDK1_4) {
+// codeStream.lookupswitch(defaultLabel, constants, sortedIndexes, caseLabels);
+//
+// } else {
+// codeStream.tableswitch(
+// defaultLabel,
+// min,
+// max,
+// constants,
+// sortedIndexes,
+// caseLabels);
+// }
+// } else {
+// codeStream.lookupswitch(defaultLabel, constants, sortedIndexes, caseLabels);
+// }
+// codeStream.updateLastRecordedEndPC(codeStream.position);
+// }
+//
+// // generate the switch block statements
+// int caseIndex = 0;
+// if (statements != null) {
+// for (int i = 0, maxCases = statements.length; i < maxCases; i++) {
+// Statement statement = statements[i];
+// if ((caseIndex < caseCount)
+// && (statement == cases[caseIndex])) { // statements[i] is a case
+// if (preSwitchInitStateIndex != -1) {
+// codeStream.removeNotDefinitelyAssignedVariables(
+// currentScope,
+// preSwitchInitStateIndex);
+// caseIndex++;
+// }
+// } else {
+// if (statement == defaultCase) { // statements[i] is a case or a default case
+// if (preSwitchInitStateIndex != -1) {
+// codeStream.removeNotDefinitelyAssignedVariables(
+// currentScope,
+// preSwitchInitStateIndex);
+// }
+// }
+// }
+// statement.generateCode(scope, codeStream);
+// }
+// }
+// // place the trailing labels (for break and default case)
+// 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(scope);
+// }
+// codeStream.recordPositionsFrom(pc, this.sourceStart);
+// }
- /**
- * get the modified variables.
- */
- public void getModifiedVariable(final List list) {
- for (int i = 0; i < cases.length; i++) {
- cases[i].getModifiedVariable(list);
- }
- variable.getModifiedVariable(list);
- }
- /**
- * Get the variables used.
- */
- public void getUsedVariable(final List list) {
- for (int i = 0; i < cases.length; i++) {
- cases[i].getUsedVariable(list);
- }
- variable.getUsedVariable(list);
- }
+ public void resetStateForCodeGeneration() {
+ if (this.breakLabel != null) {
+ this.breakLabel.resetStateForCodeGeneration();
+ }
+ }
+
+ 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) {
+
+ TypeBinding testType = expression.resolveType(upperScope);
+ if (testType == null)
+ return;
+ expression.implicitWidening(testType, testType);
+ if (!(expression.isConstantValueOfTypeAssignableToType(testType, IntBinding))) {
+ if (!testType.isCompatibleWith(IntBinding)) {
+ upperScope.problemReporter().incorrectSwitchType(expression, testType);
+ 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];
+ int[] casesValues = new int[length];
+ int counter = 0;
+ for (int i = 0; i < length; i++) {
+ Constant cst;
+ if ((cst = statements[i].resolveCase(scope, testType, this)) != null) {
+ //----check for duplicate case statement------------
+ if (cst != NotAConstant) {
+ int key = cst.intValue();
+ for (int j = 0; j < counter; j++) {
+ if (casesValues[j] == key) {
+ scope.problemReporter().duplicateCase((CaseStatement) statements[i], cst); //TODO: (philippe) could improve diagnosis to indicate colliding case
+ }
+ }
+ casesValues[counter++] = key;
+ }
+ }
+ }
+ }
+ }
+ public String toString(int tab) {
+
+ String inFront, s = tabString(tab);
+ inFront = s;
+ s = s + "switch (" + expression.toStringExpression() + ") "; //$NON-NLS-1$ //$NON-NLS-2$
+ if (statements == null) {
+ s = s + "{}"; //$NON-NLS-1$
+ return s;
+ } else
+ s = s + "{"; //$NON-NLS-1$
+ s = s
+ + (explicitDeclarations != 0
+ ? "// ---scope needed for " //$NON-NLS-1$
+ + String.valueOf(explicitDeclarations)
+ + " locals------------ \n"//$NON-NLS-1$
+ : "// ---NO scope needed------ \n"); //$NON-NLS-1$
+
+ int i = 0;
+ String tabulation = " "; //$NON-NLS-1$
+ try {
+ while (true) {
+ //use instanceof in order not to polluate classes with behavior only needed for printing purpose.
+ if (statements[i] instanceof Expression)
+ s = s + "\n" + inFront + tabulation; //$NON-NLS-1$
+ if (statements[i] instanceof BreakStatement)
+ s = s + statements[i].toString(0);
+ else
+ s = s + "\n" + statements[i].toString(tab + 2); //$NON-NLS-1$
+ //=============
+ if ((statements[i] instanceof CaseStatement)
+ || (statements[i] instanceof DefaultCase)) {
+ i++;
+ while (!((statements[i] instanceof CaseStatement)
+ || (statements[i] instanceof DefaultCase))) {
+ if ((statements[i] instanceof Expression) || (statements[i] instanceof BreakStatement))
+ s = s + statements[i].toString(0) + " ; "; //$NON-NLS-1$
+ else
+ s = s + "\n" + statements[i].toString(tab + 6) + " ; "; //$NON-NLS-1$ //$NON-NLS-2$
+ i++;
+ }
+ } else {
+ s = s + " ;"; //$NON-NLS-1$
+ i++;
+ }
+ }
+ } catch (IndexOutOfBoundsException e) {
+ };
+ s = s + "}"; //$NON-NLS-1$
+ return s;
+ }
+
+ 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);
+ }
+ }
}
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