private static IEnumerable <Diagnostic> GetDiagnostics(SymbolUsageCollector usageCollector, ISet <ISymbol> removableSymbols,
string accessibility, BidirectionalDictionary <ISymbol, SyntaxNode> fieldLikeSymbols)
{
var unusedSymbols = removableSymbols
.Except(usageCollector.UsedSymbols)
.Where(symbol => !MentionedInDebuggerDisplay(symbol))
.ToHashSet();
var propertiesWithUnusedAccessor = removableSymbols
.Intersect(usageCollector.UsedSymbols)
.OfType <IPropertySymbol>()
.Where(usageCollector.PropertyAccess.ContainsKey)
.Where(symbol => !MentionedInDebuggerDisplay(symbol));
return(GetDiagnosticsForMembers(unusedSymbols, accessibility, fieldLikeSymbols)
.Concat(propertiesWithUnusedAccessor.SelectMany(propertySymbol => GetDiagnosticsForProperty(propertySymbol, usageCollector.PropertyAccess))));
bool MentionedInDebuggerDisplay(ISymbol symbol) =>
usageCollector.DebuggerDisplayValues.Any(value => value.Contains(symbol.Name));
}
protected override void Initialize(SonarAnalysisContext context)
{
context.RegisterCompilationStartAction(
c =>
{
// Collect potentially removable internal types from the project to evaluate when
// the compilation is over, depending on whether InternalsVisibleTo attribute is present
// or not.
var removableInternalTypes = new ConcurrentBag <ISymbol>();
// Collect here all named types from the project to look for internal member usages.
var allNamedTypes = new ConcurrentBag <INamedTypeSymbol>();
c.RegisterSymbolAction(
cc =>
{
var namedType = (INamedTypeSymbol)cc.Symbol;
if (!namedType.IsClassOrStruct() ||
namedType.ContainingType != null ||
namedType.DerivesFromAny(IgnoredTypes))
{
return;
}
// Collect all symbols to try to look for used internal members when the compilation ends
allNamedTypes.Add(namedType);
// Collect symbols of private members that could potentially be removed
var removableSymbolsCollector = new RemovableSymbolCollector(c.Compilation.GetSemanticModel);
VisitDeclaringReferences(namedType, removableSymbolsCollector);
// Keep the removable internal types for when the compilation ends
foreach (var internalSymbol in removableSymbolsCollector.InternalSymbols.OfType <INamedTypeSymbol>())
{
removableInternalTypes.Add(internalSymbol);
}
var usageCollector = new SymbolUsageCollector(
c.Compilation.GetSemanticModel,
removableSymbolsCollector.PrivateSymbols.Select(s => s.Name).ToHashSet());
VisitDeclaringReferences(namedType, usageCollector);
var diagnostics = GetDiagnostics(usageCollector, removableSymbolsCollector.PrivateSymbols, "private",
removableSymbolsCollector.FieldLikeSymbols);
foreach (var diagnostic in diagnostics)
{
cc.ReportDiagnosticIfNonGenerated(diagnostic, cc.Compilation);
}
},
SymbolKind.NamedType);
c.RegisterCompilationEndAction(
cc =>
{
var foundInternalsVisibleTo = cc.Compilation.Assembly
.GetAttributes(KnownType.System_Runtime_CompilerServices_InternalsVisibleToAttribute)
.Any();
if (foundInternalsVisibleTo ||
removableInternalTypes.Count == 0)
{
return;
}
var usageCollector = new SymbolUsageCollector(
c.Compilation.GetSemanticModel,
removableInternalTypes.Select(s => s.Name).ToHashSet());
foreach (var symbol in allNamedTypes)
{
VisitDeclaringReferences(symbol, usageCollector);
}
var diagnostics = GetDiagnostics(usageCollector, removableInternalTypes.ToHashSet(), "internal",
new BidirectionalDictionary <ISymbol, SyntaxNode>());
foreach (var diagnostic in diagnostics)
{
cc.ReportDiagnosticIfNonGenerated(diagnostic, cc.Compilation);
}
});
});
}