SwitchInformation GetInformationAboutSwitch(SemanticModel model, SwitchStatementSyntax node, CancellationToken ct)
{
try
{
SwitchInformation info = new SwitchInformation();
var type = model.GetTypeInfo(node.Expression, ct).Type;
if (isEnum(type))
{
var defaults = node.Sections.SelectMany(s => s.Labels).OfType <DefaultSwitchLabelSyntax>().ToArray();
info.HasDefault = defaults.Any();
if (info.HasDefault)
{
var d = defaults.First();
var first = ((SwitchSectionSyntax)d.Parent).Statements.FirstOrDefault();
info.DefaultIsThrow = first is ThrowStatementSyntax;
}
info.NotFoundSymbolNames = GetUnusedSymbolNames(model, node, type, ct);
return(info);
}
}
catch (Exception)
{
// ignored
}
return(null);
}
private void Analyze(SyntaxNodeAnalysisContext context)
{
if (context.Node is SwitchStatementSyntax switchSyntax)
{
SwitchInformation information = GetInformationAboutSwitch(context.SemanticModel, switchSyntax, context.CancellationToken);
if (information is SwitchInformation)
{
if (information.NotExhaustiveSwitch)
{
var diagnostic = Diagnostic.Create(NotExhaustiveSwitchRule, switchSyntax.Expression.GetLocation(), string.Join("\n", information.NotFoundSymbolNames));
context.ReportDiagnostic(diagnostic);
}
else if (information.UnreachableDefault)
{
var diagnostic = Diagnostic.Create(DefaultUnreachableRule, switchSyntax.Expression.GetLocation());
context.ReportDiagnostic(diagnostic);
}
}
}
}