private static void ResolveGhostedCatchParameter(JsActivationObject scope, JsParameterDeclaration catchParameter)
{
// check to see if the name exists in the outer variable scope.
var ghostField = scope[catchParameter.Name];
if (ghostField == null)
{
// set up a ghost field to keep track of the relationship
ghostField = new JsVariableField(JsFieldType.GhostCatch, catchParameter.Name, 0, null)
{
OriginalContext = catchParameter.Context
};
scope.AddField(ghostField);
}
else if (ghostField.FieldType == JsFieldType.GhostCatch)
{
// there is, but it's another ghost catch variable. That's fine; just use it.
// don't even flag it as ambiguous because if someone is later referencing the error variable
// used in a couple catch variables, we'll say something then because other browsers will have that
// variable undefined or from an outer scope.
}
else
{
// there is, and it's NOT another ghosted catch variable. Possible naming
// collision in IE -- if an error happens, it will clobber the existing field's value,
// although that MAY be the intention; we don't know for sure. But it IS a cross-
// browser behavior difference.
ghostField.IsAmbiguous = true;
if (ghostField.OuterField != null)
{
// and to make matters worse, it's actually bound to an OUTER field
// in modern browsers, but will bind to this catch variable in older
// versions of IE! Definitely a cross-browser difference!
// throw a cross-browser issue error.
catchParameter.Context.HandleError(JsError.AmbiguousCatchVar);
}
}
// link them so they all keep the same name going forward
// (since they are named the same in the sources)
catchParameter.VariableField.OuterField = ghostField;
// TODO: this really should be a LIST of ghosted fields, since multiple
// elements can ghost to the same field.
ghostField.GhostedField = catchParameter.VariableField;
// if the actual field has references, we want to bubble those up
// since we're now linking those fields
if (catchParameter.VariableField.RefCount > 0)
{
// add the catch parameter's references to the ghost field
ghostField.AddReferences(catchParameter.VariableField.References);
}
}
public void Visit(JsParameterDeclaration node)
{
// shoudn't get here
Debug.Fail("shouldn't get here");
}
public void Visit(JsParameterDeclaration node)
{
// not applicable; terminate
}
internal JsCatchScope(JsActivationObject parent, JsContext catchContext, JsSettings settings, JsParameterDeclaration catchParameter)
: base(parent, catchContext, settings)
{
CatchParameter = catchParameter;
}
public void Visit(JsParameterDeclaration node)
{
// invalid! ignore
IsValid = false;
}
public void Visit(JsParameterDeclaration node)
{
// nothing to do
}
public void Visit(JsParameterDeclaration node)
{
// we're good
}