net.sourceforge.phpeclipse/src/net/sourceforge/phpdt/internal/compiler/ast/Case.java

   1 /*******************************************************************************
   2  * Copyright (c) 2000, 2001, 2002 International Business Machines Corp. and others.
   3  * All rights reserved. This program and the accompanying materials
   4  * are made available under the terms of the Common Public License v0.5
   5  * which accompanies this distribution, and is available at
   6  * http://www.eclipse.org/legal/cpl-v05.html
   7  *
   8  * Contributors:
   9  *     IBM Corporation - initial API and implementation
  10  ******************************************************************************/
  11 package net.sourceforge.phpdt.internal.compiler.ast;
  12
  13 import net.sourceforge.phpdt.internal.compiler.IAbstractSyntaxTreeVisitor;
  14 import net.sourceforge.phpdt.internal.compiler.impl.*;
  15 import net.sourceforge.phpdt.internal.compiler.codegen.*;
  16 import net.sourceforge.phpdt.internal.compiler.flow.*;
  17 import net.sourceforge.phpdt.internal.compiler.lookup.*;
  18
  19 public class Case extends Statement {
  20
  21         public Expression constantExpression;
  22         public CaseLabel targetLabel;
  23         public Case(int sourceStart, Expression constantExpression) {
  24                 this.constantExpression = constantExpression;
  25                 this.sourceEnd = constantExpression.sourceEnd;
  26                 this.sourceStart = sourceStart;
  27         }
  28
  29         public FlowInfo analyseCode(
  30                 BlockScope currentScope,
  31                 FlowContext flowContext,
  32                 FlowInfo flowInfo) {
  33
  34                 if (constantExpression.constant == NotAConstant)
  35                         currentScope.problemReporter().caseExpressionMustBeConstant(constantExpression);
  36
  37                 this.constantExpression.analyseCode(currentScope, flowContext, flowInfo);
  38                 return flowInfo;
  39         }
  40
  41         /**
  42          * Case code generation
  43          *
  44          */
  45         public void generateCode(BlockScope currentScope, CodeStream codeStream) {
  46
  47                 if ((bits & IsReachableMASK) == 0) {
  48                         return;
  49                 }
  50                 int pc = codeStream.position;
  51                 targetLabel.place();
  52                 codeStream.recordPositionsFrom(pc, this.sourceStart);
  53         }
  54
  55         public void resolve(BlockScope scope) {
  56
  57                 // error....use resolveCase....
  58                 throw new NullPointerException();
  59         }
  60
  61         public Constant resolveCase(
  62                 BlockScope scope,
  63                 TypeBinding testTb,
  64                 SwitchStatement switchStatement) {
  65
  66                 // add into the collection of cases of the associated switch statement
  67                 switchStatement.cases[switchStatement.caseCount++] = this;
  68                 TypeBinding caseTb = constantExpression.resolveType(scope);
  69                 if (caseTb == null || testTb == null)
  70                         return null;
  71                 if (constantExpression.isConstantValueOfTypeAssignableToType(caseTb, testTb))
  72                         return constantExpression.constant;
  73                 if (scope.areTypesCompatible(caseTb, testTb))
  74                         return constantExpression.constant;
  75                 scope.problemReporter().typeMismatchErrorActualTypeExpectedType(
  76                         constantExpression,
  77                         caseTb,
  78                         testTb);
  79                 return null;
  80         }
  81
  82         public String toString(int tab) {
  83
  84                 String s = tabString(tab);
  85                 s = s + "case " + constantExpression.toStringExpression() + " : "; //$NON-NLS-1$ //$NON-NLS-2$
  86                 return s;
  87         }
  88
  89         public void traverse(
  90                 IAbstractSyntaxTreeVisitor visitor,
  91                 BlockScope blockScope) {
  92
  93                 if (visitor.visit(this, blockScope)) {
  94                         constantExpression.traverse(visitor, blockScope);
  95                 }
  96                 visitor.endVisit(this, blockScope);
  97         }
  98 }