private static void Analyze(
SymbolAnalysisContext context
)
{
var symbol = (INamedTypeSymbol)context.Symbol;
if (!symbol.IsDefinition)
{
return;
}
foreach (ITypeSymbol argument in symbol.TypeArguments)
{
ImmutabilityScope scope = argument.GetImmutabilityScope();
if (scope == ImmutabilityScope.SelfAndChildren)
{
continue;
}
if (ImmutableGenericArgument.BaseClassDemandsImmutability(symbol, argument) ||
ImmutableGenericArgument.InterfacesDemandImmutability(symbol, argument) ||
ImmutableGenericArgument.ConstraintsDemandImmutabliity(symbol, argument)
)
{
context.ReportDiagnostic(Diagnostic.Create(
Diagnostics.GenericArgumentImmutableMustBeApplied,
argument.DeclaringSyntaxReferences
.First()
.GetSyntax()
.GetLocation()));
}
}
}
private static bool SymbolDemandsImmutability(
ITypeSymbol symbol,
ITypeSymbol argument
)
{
var symbolType = symbol as INamedTypeSymbol;
if (symbolType == default)
{
return(false);
}
int ordinal = symbolType.IndexOfArgument(argument.Name);
if (ordinal < 0)
{
return(false);
}
ImmutabilityScope argumentScope =
symbolType.TypeParameters[ordinal].GetImmutabilityScope();
if (argumentScope == ImmutabilityScope.SelfAndChildren)
{
return(true);
}
return(false);
}
private static void AnalyzeNode(
SyntaxNodeAnalysisContext context
)
{
var syntaxNode = context.Node as GenericNameSyntax;
// Attributes are not allowed on local function parameters so we
// have to ignore this node, otherwise we'll tell people to
// annotate a declaration that is forbidden.
if (syntaxNode.Ancestors().Any(a => a is LocalFunctionStatementSyntax))
{
return;
}
SymbolInfo hostTypeSymbolInfo = context.SemanticModel.GetSymbolInfo(syntaxNode);
var hostTypeSymbol = hostTypeSymbolInfo.Symbol as INamedTypeSymbol;
if (hostTypeSymbol == default)
{
return;
}
TypeArgumentListSyntax typeArgumentNode = syntaxNode.TypeArgumentList;
for (int index = 0; index < typeArgumentNode.Arguments.Count; index++)
{
ITypeParameterSymbol hostParameterSymbol = hostTypeSymbol.TypeParameters[index];
ImmutabilityScope declarationScope = hostParameterSymbol.GetImmutabilityScope();
if (declarationScope != ImmutabilityScope.SelfAndChildren)
{
continue;
}
SymbolInfo argumentSymbolInfo = context.SemanticModel.GetSymbolInfo(typeArgumentNode.Arguments[index]);
var typeSymbol = argumentSymbolInfo.Symbol as ITypeSymbol;
if (typeSymbol == default)
{
continue;
}
ValidateImmutability(
context,
typeSymbol
);
}
}