public UnusedParametersAnalyzer(IMethodSymbol method, UnusedParameterDictionary finalUnusedParameters)
{
// Initialization: Assume all parameters are unused.
_unusedParameters = new HashSet <IParameterSymbol>(method.Parameters);
_finalUnusedParameters = finalUnusedParameters;
_method = method;
}
public UnusedParametersAnalyzer(IMethodSymbol method, UnusedParameterDictionary finalUnusedParameters)
{
// Initialization: Assume all parameters are unused, except the ones with special discard name.
_unusedParameters = new HashSet <IParameterSymbol>(method.Parameters.Where(p => !p.IsSymbolWithSpecialDiscardName()));
_finalUnusedParameters = finalUnusedParameters;
_method = method;
}
public UnusedParametersAnalyzer(IMethodSymbol method, UnusedParameterDictionary finalUnusedParameters, ImmutableHashSet <INamedTypeSymbol> exceptionsToSkip)
{
// Initialization: Assume all parameters are unused.
_unusedParameters = new HashSet <IParameterSymbol>(method.Parameters);
_exceptionsToSkip = exceptionsToSkip;
_finalUnusedParameters = finalUnusedParameters;
_method = method;
}
private static void AnalyzeMethod(
IMethodSymbol method,
OperationBlockStartAnalysisContext startOperationBlockContext,
UnusedParameterDictionary unusedMethodParameters,
INamedTypeSymbol eventsArgSymbol,
ISet <IMethodSymbol> methodsUsedAsDelegates,
ImmutableHashSet <INamedTypeSymbol> attributeSetForMethodsToIgnore)
{
// We only care about methods with parameters.
if (method.Parameters.IsEmpty)
{
return;
}
// Ignore implicitly declared methods, extern methods, abstract methods, virtual methods, interface implementations and finalizers (FxCop compat).
if (method.IsImplicitlyDeclared ||
method.IsExtern ||
method.IsAbstract ||
method.IsVirtual ||
method.IsOverride ||
method.IsImplementationOfAnyInterfaceMember() ||
method.IsFinalizer())
{
return;
}
// Ignore property accessors.
if (method.IsPropertyAccessor())
{
return;
}
// Ignore event handler methods "Handler(object, MyEventArgs)"
if (eventsArgSymbol != null &&
method.Parameters.Length == 2 &&
method.Parameters[0].Type.SpecialType == SpecialType.System_Object &&
method.Parameters[1].Type.Inherits(eventsArgSymbol))
{
return;
}
// Ignore methods with any attributes in 'attributeSetForMethodsToIgnore'.
if (method.GetAttributes().Any(a => a.AttributeClass != null && attributeSetForMethodsToIgnore.Contains(a.AttributeClass)))
{
return;
}
// Ignore methods that were used as delegates
if (methodsUsedAsDelegates.Contains(method))
{
return;
}
// Initialize local mutable state in the start action.
var analyzer = new UnusedParametersAnalyzer(method, unusedMethodParameters);
// Register an intermediate non-end action that accesses and modifies the state.
startOperationBlockContext.RegisterOperationAction(analyzer.AnalyzeParameterReference, OperationKind.ParameterReference);
// Register an end action to add unused parameters to the unusedMethodParameters dictionary
startOperationBlockContext.RegisterOperationBlockEndAction(analyzer.OperationBlockEndAction);
}
private static void AnalyzeMethod(
IMethodSymbol method,
OperationBlockStartAnalysisContext startOperationBlockContext,
UnusedParameterDictionary unusedMethodParameters,
INamedTypeSymbol?eventsArgSymbol,
ISet <IMethodSymbol> methodsUsedAsDelegates,
ImmutableHashSet <INamedTypeSymbol?> attributeSetForMethodsToIgnore)
{
// We only care about methods with parameters.
if (method.Parameters.IsEmpty)
{
return;
}
// Ignore implicitly declared methods, extern methods, abstract methods, virtual methods, interface implementations and finalizers (FxCop compat).
if (method.IsImplicitlyDeclared ||
method.IsExtern ||
method.IsAbstract ||
method.IsVirtual ||
method.IsOverride ||
method.IsImplementationOfAnyInterfaceMember() ||
method.IsFinalizer())
{
return;
}
// Ignore property accessors.
if (method.IsPropertyAccessor())
{
return;
}
// Ignore event handler methods "Handler(object, MyEventArgs)"
if (method.Parameters.Length == 2 &&
method.Parameters[0].Type.SpecialType == SpecialType.System_Object &&
// UWP has specific EventArgs not inheriting from System.EventArgs. It was decided to go for a suffix match rather than a whitelist.
(method.Parameters[1].Type.Inherits(eventsArgSymbol) || method.Parameters[1].Type.Name.EndsWith("EventArgs", StringComparison.Ordinal)))
{
return;
}
// Ignore methods with any attributes in 'attributeSetForMethodsToIgnore'.
if (method.GetAttributes().Any(a => a.AttributeClass != null && attributeSetForMethodsToIgnore.Contains(a.AttributeClass)))
{
return;
}
// Ignore methods that were used as delegates
if (methodsUsedAsDelegates.Contains(method))
{
return;
}
// Bail out if user has configured to skip analysis for the method.
if (!method.MatchesConfiguredVisibility(
startOperationBlockContext.Options,
Rule,
startOperationBlockContext.CancellationToken,
defaultRequiredVisibility: SymbolVisibilityGroup.All))
{
return;
}
// Initialize local mutable state in the start action.
var analyzer = new UnusedParametersAnalyzer(method, unusedMethodParameters);
// Register an intermediate non-end action that accesses and modifies the state.
startOperationBlockContext.RegisterOperationAction(analyzer.AnalyzeParameterReference, OperationKind.ParameterReference);
// Register an end action to add unused parameters to the unusedMethodParameters dictionary
startOperationBlockContext.RegisterOperationBlockEndAction(analyzer.OperationBlockEndAction);
}
