static string GetContextName(RoslynReflectionAllowedContext context)
{
switch (context)
{
case RoslynReflectionAllowedContext.Analyzers:
return("analyzers");
case RoslynReflectionAllowedContext.CodeFixes:
return("code fixes/refactorings");
}
return("");
}
static RoslynReflectionAllowedContext GetContextFromClass(INamedTypeSymbol symbol)
{
RoslynReflectionAllowedContext surroundingContext = RoslynReflectionAllowedContext.None;
var surroundingClassAttributes = symbol.GetAttributes();
if (surroundingClassAttributes.Any(a => a.AttributeClass.GetFullName() == typeof(DiagnosticAnalyzerAttribute).FullName))
{
surroundingContext = RoslynReflectionAllowedContext.Analyzers;
}
else if (surroundingClassAttributes.Any(a => a.AttributeClass.GetFullName() == typeof(ExportCodeFixProviderAttribute).FullName))
{
surroundingContext = RoslynReflectionAllowedContext.CodeFixes;
}
else if (surroundingClassAttributes.Any(a => a.AttributeClass.GetFullName() == typeof(ExportCodeRefactoringProviderAttribute).FullName))
{
surroundingContext = RoslynReflectionAllowedContext.CodeFixes;
}
return(surroundingContext);
}
public RoslynReflectionUsageAttribute(RoslynReflectionAllowedContext allowedContexts = RoslynReflectionAllowedContext.None)
{
AllowedContexts = allowedContexts;
}
static bool TryGetDiagnostic(SyntaxNodeAnalysisContext nodeContext, out Diagnostic diagnostic)
{
diagnostic = default(Diagnostic);
var semanticModel = nodeContext.SemanticModel;
var node = nodeContext.Node as MemberAccessExpressionSyntax;
var symbol = semanticModel.GetSymbolInfo(node.Name).Symbol;
if (symbol == null)
{
return(false);
}
RoslynReflectionAllowedContext surroundingContext = RoslynReflectionAllowedContext.None;
var surroundingClass = node.Ancestors().OfType <ClassDeclarationSyntax>().FirstOrDefault();
if (surroundingClass == null)
{
return(false);
}
var surroundingClassSymbol = semanticModel.GetDeclaredSymbol(surroundingClass);
if (surroundingClassSymbol == null)
{
return(false);
}
surroundingContext = GetContextFromClass(surroundingClassSymbol);
if (surroundingContext == RoslynReflectionAllowedContext.None)
{
return(false);
}
var reflectionUsageAttributeData =
symbol.GetAttributes().FirstOrDefault(a => a.AttributeClass.GetFullName() == typeof(RoslynReflectionUsageAttribute).FullName);
if (reflectionUsageAttributeData == null)
{
var containingTypeSymbol = symbol.ContainingType;
if (containingTypeSymbol != null)
{
reflectionUsageAttributeData =
containingTypeSymbol.GetAttributes().FirstOrDefault(a => a.AttributeClass.GetFullName() == typeof(RoslynReflectionUsageAttribute).FullName);
}
}
string diagnosticMessage = "";
RoslynReflectionAllowedContext allowedContext = RoslynReflectionAllowedContext.None;
if (reflectionUsageAttributeData != null)
{
var attributeParam = reflectionUsageAttributeData.ConstructorArguments.FirstOrDefault();
if (attributeParam.Value is int)
{
allowedContext = (RoslynReflectionAllowedContext)attributeParam.Value;
}
diagnosticMessage = "This call accesses Roslyn features through reflection, although not allowed in {0}.";
}
else
{
if (surroundingContext == RoslynReflectionAllowedContext.Analyzers)
{
var symbolContainingType = symbol.ContainingType;
if (symbolContainingType != null)
{
allowedContext = GetContextFromClass(symbolContainingType);
}
}
else
{
allowedContext = RoslynReflectionAllowedContext.Analyzers | RoslynReflectionAllowedContext.CodeFixes;
}
diagnosticMessage = "Accessing members from code fixes/refactorings is not allowed in {0}.";
}
if ((allowedContext == RoslynReflectionAllowedContext.None) || (allowedContext.HasFlag(surroundingContext)))
{
return(false);
}
diagnostic = Diagnostic.Create(
descriptor,
node.Name.GetLocation(),
string.Format(diagnosticMessage, GetContextName(surroundingContext))
);
return(true);
}
static string GetContextName(RoslynReflectionAllowedContext context)
{
switch (context)
{
case RoslynReflectionAllowedContext.Analyzers:
return "analyzers";
case RoslynReflectionAllowedContext.CodeFixes:
return "code fixes/refactorings";
}
return "";
}
public RoslynReflectionUsageAttribute(RoslynReflectionAllowedContext allowedContexts = RoslynReflectionAllowedContext.None)
{
AllowedContexts = allowedContexts;
}
