private void DefineField(ResolutionVisitor resolutionVisitor, INameDeclaration nameDecl)
{
if (nameDecl == null)
{
// malformed code, for example catch w/o a variable.
return;
}
var field = this[nameDecl.Name];
if (nameDecl is ParameterDeclaration)
{
// function parameters are handled separately, so if this is a parameter declaration,
// then it must be a catch variable.
if (field == null)
{
// no collision - create the catch-error field
field = new JSVariableField(FieldType.CatchError, nameDecl.Name);
this.AddField(field);
}
else
{
// it's an error to declare anything in the catch scope with the same name as the
// error variable
ErrorSink.HandleError(JSError.DuplicateCatch, nameDecl.GetNameSpan(GlobalScope.Node.LocationResolver), resolutionVisitor._locationResolver, true);
}
}
else
{
if (field == null)
{
// could be global or local depending on the scope, so let the scope create it.
field = this.CreateField(nameDecl.Name);
// if this field is a constant, mark it now
var lexDeclaration = nameDecl.Parent as LexicalDeclaration;
this.AddField(field);
}
else
{
// already defined!
// if this is a lexical declaration, then it's an error because we have two
// lexical declarations with the same name in the same scope.
if (nameDecl.Parent is LexicalDeclaration)
{
_errorSink.HandleError(
JSError.DuplicateLexicalDeclaration,
nameDecl.GetNameSpan(GlobalScope.Node.LocationResolver),
resolutionVisitor._locationResolver,
true
);
}
}
}
nameDecl.VariableField = field;
}
private void ResolveGhostedCatchParameter(ActivationObject scope, ParameterDeclaration 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(FieldType.GhostCatch, catchParameter.Name);
scope.AddField(ghostField);
}
else if (ghostField.FieldType == FieldType.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.
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.
_errorSink.HandleError(JSError.AmbiguousCatchVar, catchParameter.GetSpan(_locationResolver), _locationResolver);
}
}
// link them so they all keep the same name going forward
// (since they are named the same in the sources)
catchParameter.VariableField.OuterField = ghostField;
}