/*
  * Creates the value wrapper from the given expression, and sets the valueKind on the given memberValuePair
  */
 private Object getAnnotationMemberValue(
     MemberValuePair memberValuePair, Expression expression, JavaElement parentElement) {
   if (expression instanceof NullLiteral) {
     return null;
   } else if (expression instanceof Literal) {
     ((Literal) expression).computeConstant();
     return Util.getAnnotationMemberValue(memberValuePair, expression.constant);
   } else if (expression instanceof org.aspectj.org.eclipse.jdt.internal.compiler.ast.Annotation) {
     memberValuePair.valueKind = IMemberValuePair.K_ANNOTATION;
     return getAnnotation(
         (org.aspectj.org.eclipse.jdt.internal.compiler.ast.Annotation) expression, parentElement);
   } else if (expression instanceof ClassLiteralAccess) {
     ClassLiteralAccess classLiteral = (ClassLiteralAccess) expression;
     char[] typeName = CharOperation.concatWith(classLiteral.type.getTypeName(), '.');
     memberValuePair.valueKind = IMemberValuePair.K_CLASS;
     return new String(typeName);
   } else if (expression instanceof QualifiedNameReference) {
     char[] qualifiedName =
         CharOperation.concatWith(((QualifiedNameReference) expression).tokens, '.');
     memberValuePair.valueKind = IMemberValuePair.K_QUALIFIED_NAME;
     return new String(qualifiedName);
   } else if (expression instanceof SingleNameReference) {
     char[] simpleName = ((SingleNameReference) expression).token;
     if (simpleName == RecoveryScanner.FAKE_IDENTIFIER) {
       memberValuePair.valueKind = IMemberValuePair.K_UNKNOWN;
       return null;
     }
     memberValuePair.valueKind = IMemberValuePair.K_SIMPLE_NAME;
     return new String(simpleName);
   } else if (expression instanceof ArrayInitializer) {
     memberValuePair.valueKind = -1; // modified below by the first call to getMemberValue(...)
     Expression[] expressions = ((ArrayInitializer) expression).expressions;
     int length = expressions == null ? 0 : expressions.length;
     Object[] values = new Object[length];
     for (int i = 0; i < length; i++) {
       int previousValueKind = memberValuePair.valueKind;
       Object value = getAnnotationMemberValue(memberValuePair, expressions[i], parentElement);
       if (previousValueKind != -1 && memberValuePair.valueKind != previousValueKind) {
         // values are heterogeneous, value kind is thus unknown
         memberValuePair.valueKind = IMemberValuePair.K_UNKNOWN;
       }
       values[i] = value;
     }
     if (memberValuePair.valueKind == -1) memberValuePair.valueKind = IMemberValuePair.K_UNKNOWN;
     return values;
   } else if (expression
       instanceof UnaryExpression) { // to deal with negative numerals (see bug - 248312)
     UnaryExpression unaryExpression = (UnaryExpression) expression;
     if ((unaryExpression.bits & ASTNode.OperatorMASK) >> ASTNode.OperatorSHIFT
         == OperatorIds.MINUS) {
       if (unaryExpression.expression instanceof Literal) {
         Literal subExpression = (Literal) unaryExpression.expression;
         subExpression.computeConstant();
         return Util.getNegativeAnnotationMemberValue(memberValuePair, subExpression.constant);
       }
     }
     memberValuePair.valueKind = IMemberValuePair.K_UNKNOWN;
     return null;
   } else {
     memberValuePair.valueKind = IMemberValuePair.K_UNKNOWN;
     return null;
   }
 }