private static bool IsMentionedInDebuggerDisplay(ISymbol symbol, CSharpSymbolUsageCollector usageCollector) => 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>();
c.RegisterSymbolAction(
cc =>
{
var namedType = (INamedTypeSymbol)cc.Symbol;
if (!namedType.IsClassOrStruct() ||
namedType.ContainingType != null ||
namedType.DerivesFromAny(IgnoredTypes))
{
return;
}
// Collect symbols of private members that could potentially be removed
var removableSymbolsCollector = new CSharpRemovableSymbolWalker(c.Compilation.GetSemanticModel);
if (!VisitDeclaringReferences(namedType, removableSymbolsCollector, c.Compilation))
{
return;
}
// Keep the removable internal types for when the compilation ends
foreach (var internalSymbol in removableSymbolsCollector.InternalSymbols.OfType <INamedTypeSymbol>())
{
removableInternalTypes.Add(internalSymbol);
}
var usageCollector = new CSharpSymbolUsageCollector(
c.Compilation.GetSemanticModel,
removableSymbolsCollector.PrivateSymbols.Select(s => s.Name).ToHashSet());
if (!VisitDeclaringReferences(namedType, usageCollector, c.Compilation))
{
return;
}
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 CSharpSymbolUsageCollector(
c.Compilation.GetSemanticModel,
removableInternalTypes.Select(s => s.Name).ToHashSet());
foreach (var syntaxTree in c.Compilation.SyntaxTrees.Where(tree => !tree.IsGenerated(c.Compilation)))
{
usageCollector.SafeVisit(syntaxTree.GetRoot());
}
var diagnostics = GetDiagnostics(usageCollector, removableInternalTypes.ToHashSet(), "internal",
new BidirectionalDictionary <ISymbol, SyntaxNode>());
foreach (var diagnostic in diagnostics)
{
cc.ReportDiagnosticIfNonGenerated(diagnostic, cc.Compilation);
}
});
});
}
private static IEnumerable <Diagnostic> GetDiagnosticsForUnusedPrivateMembers(CSharpSymbolUsageCollector usageCollector, ISet <ISymbol> removableSymbols, string accessibility,
BidirectionalDictionary <ISymbol, SyntaxNode> fieldLikeSymbols)
{
var unusedSymbols = GetUnusedSymbols(usageCollector, removableSymbols);
var propertiesWithUnusedAccessor = removableSymbols
.Intersect(usageCollector.UsedSymbols)
.OfType <IPropertySymbol>()
.Where(usageCollector.PropertyAccess.ContainsKey)
.Where(symbol => !IsMentionedInDebuggerDisplay(symbol, usageCollector))
.Select(symbol => GetDiagnosticsForProperty(symbol, usageCollector.PropertyAccess))
.WhereNotNull();
return(GetDiagnosticsForMembers(unusedSymbols, accessibility, fieldLikeSymbols).Concat(propertiesWithUnusedAccessor));
}
private static HashSet <ISymbol> GetUnusedSymbols(CSharpSymbolUsageCollector usageCollector, ISet <ISymbol> removableSymbols) => removableSymbols .Except(usageCollector.UsedSymbols) .Where(symbol => !IsMentionedInDebuggerDisplay(symbol, usageCollector)) .ToHashSet();
