public override void Initialize(AnalysisContext context)
{
context.EnableConcurrentExecution();
context.ConfigureGeneratedCodeAnalysis(GeneratedCodeAnalysisFlags.None);
context.RegisterCompilationStartAction(compilationContext =>
{
compilationContext.RegisterOperationBlockAction(operationBlockContext =>
{
// Analyze externally visible methods with reference type parameters.
if (!(operationBlockContext.OwningSymbol is IMethodSymbol containingMethod) ||
!containingMethod.IsExternallyVisible() ||
!containingMethod.Parameters.Any(p => p.Type.IsReferenceType))
{
return;
}
// Bail out early if we have no parameter references in the method body.
if (!operationBlockContext.OperationBlocks.HasAnyOperationDescendant(OperationKind.ParameterReference))
{
return;
}
// Perform analysis of all direct/indirect parameter usages in the method to get all non-validated usages that can cause a null dereference.
ImmutableDictionary <IParameterSymbol, SyntaxNode> hazardousParameterUsages = null;
foreach (var operationBlock in operationBlockContext.OperationBlocks)
{
if (operationBlock is IBlockOperation topmostBlock)
{
hazardousParameterUsages = ParameterValidationAnalysis.GetOrComputeHazardousParameterUsages(
topmostBlock, operationBlockContext.Compilation, containingMethod,
operationBlockContext.Options, Rule, operationBlockContext.CancellationToken);
break;
}
}
if (hazardousParameterUsages != null)
{
foreach (var kvp in hazardousParameterUsages)
{
IParameterSymbol parameter = kvp.Key;
SyntaxNode node = kvp.Value;
// In externally visible method '{0}', validate parameter '{1}' is non-null before using it. If appropriate, throw an ArgumentNullException when the argument is null or add a Code Contract precondition asserting non-null argument.
var arg1 = containingMethod.ToDisplayString(SymbolDisplayFormat.MinimallyQualifiedFormat);
var arg2 = parameter.Name;
var diagnostic = node.CreateDiagnostic(Rule, arg1, arg2);
operationBlockContext.ReportDiagnostic(diagnostic);
}
}
});
});
}
public override void Initialize(AnalysisContext context)
{
context.EnableConcurrentExecution();
context.ConfigureGeneratedCodeAnalysis(GeneratedCodeAnalysisFlags.None);
context.RegisterCompilationStartAction(compilationContext =>
{
compilationContext.RegisterOperationBlockAction(operationBlockContext =>
{
// Analyze externally visible methods with reference type parameters.
if (operationBlockContext.OwningSymbol is not IMethodSymbol containingMethod ||
!containingMethod.IsExternallyVisible() ||
!containingMethod.Parameters.Any(p => p.Type.IsReferenceType) ||
operationBlockContext.Options.IsConfiguredToSkipAnalysis(Rule, containingMethod, operationBlockContext.Compilation))
{
return;
}
// Bail out for protected members of sealed classes if the entire overridden method chain
// is defined in the same assembly.
if (containingMethod.IsOverride &&
containingMethod.ContainingType.IsSealed)
{
var overriddenMethod = containingMethod.OverriddenMethod;
var hasAssemblyMismatch = false;
while (overriddenMethod != null)
{
if (!Equals(overriddenMethod.ContainingAssembly, containingMethod.ContainingAssembly))
{
hasAssemblyMismatch = true;
break;
}
overriddenMethod = overriddenMethod.OverriddenMethod;
}
if (!hasAssemblyMismatch)
{
return;
}
}
// Bail out early if we have no parameter references in the method body.
if (!operationBlockContext.OperationBlocks.HasAnyOperationDescendant(OperationKind.ParameterReference))
{
return;
}
// Perform analysis of all direct/indirect parameter usages in the method to get all non-validated usages that can cause a null dereference.
ImmutableDictionary <IParameterSymbol, SyntaxNode>?hazardousParameterUsages = null;
foreach (var operationBlock in operationBlockContext.OperationBlocks)
{
if (operationBlock is IBlockOperation topmostBlock)
{
hazardousParameterUsages = ParameterValidationAnalysis.GetOrComputeHazardousParameterUsages(
topmostBlock, operationBlockContext.Compilation, containingMethod,
operationBlockContext.Options, Rule);
break;
}
}
if (hazardousParameterUsages != null)
{
foreach (var kvp in hazardousParameterUsages)
{
IParameterSymbol parameter = kvp.Key;
SyntaxNode node = kvp.Value;
// Check if user has configured to skip extension method 'this' parameter analysis.
if (containingMethod.IsExtensionMethod &&
Equals(containingMethod.Parameters[0], parameter))
{
bool excludeThisParameterOption = operationBlockContext.Options.GetBoolOptionValue(
optionName: EditorConfigOptionNames.ExcludeExtensionMethodThisParameter,
rule: Rule,
containingMethod,
operationBlockContext.Compilation,
defaultValue: false);
if (excludeThisParameterOption)
{
continue;
}
}
// In externally visible method '{0}', validate parameter '{1}' is non-null before using it. If appropriate, throw an ArgumentNullException when the argument is null or add a Code Contract precondition asserting non-null argument.
var arg1 = containingMethod.ToDisplayString(SymbolDisplayFormat.MinimallyQualifiedFormat);
var arg2 = parameter.Name;
var diagnostic = node.CreateDiagnostic(Rule, arg1, arg2);
operationBlockContext.ReportDiagnostic(diagnostic);
}
}
});
});
}
