private static void Handle(SyntaxNodeAnalysisContext context)
{
if (!context.IsExcludedFromAnalysis() &&
context.Node is InvocationExpressionSyntax invocation &&
invocation.ArgumentList != null &&
invocation.Expression is MemberAccessExpressionSyntax memberAccess &&
invocation.TryGetMethodName(out var name) &&
name == "Invoke" &&
context.SemanticModel.TryGetSymbol(invocation, context.CancellationToken, out var invoke) &&
invoke.ContainingType.IsAssignableTo(KnownSymbol.MemberInfo, context.Compilation) &&
invoke.TryFindParameter("parameters", out var parametersParameter) &&
invocation.TryFindArgument(parametersParameter, out var parametersArg))
{
if (context.SemanticModel.TryGetType(parametersArg.Expression, context.CancellationToken, out var type) &&
type is IArrayTypeSymbol arrayType &&
arrayType.ElementType == KnownSymbol.Object &&
Array.IsCreatingEmpty(parametersArg.Expression, context))
{
context.ReportDiagnostic(Diagnostic.Create(REFL024PreferNullOverEmptyArray.Descriptor, parametersArg.GetLocation()));
}
if (GetX.TryGetMethodInfo(memberAccess, context, out var method))
{
if (!method.ReturnsVoid &&
ReturnValue.ShouldCast(invocation, method.ReturnType, context))
{
context.ReportDiagnostic(
Diagnostic.Create(
REFL001CastReturnValue.Descriptor,
invocation.GetLocation(),
ImmutableDictionary <string, string> .Empty.Add(
nameof(TypeSyntax),
method.ReturnType.ToString(context)),
method.ReturnType.ToString(context)));
}
if (method.ReturnsVoid &&
!IsResultDiscarded(invocation, context))
{
context.ReportDiagnostic(Diagnostic.Create(REFL002DiscardReturnValue.Descriptor, invocation.GetLocation()));
}
if (Array.TryGetValues(parametersArg.Expression, context, out var values) &&
Arguments.TryFindFirstMisMatch(method.Parameters, values, context, out var misMatch) == true)
{
context.ReportDiagnostic(Diagnostic.Create(REFL025ArgumentsDontMatchParameters.Descriptor, misMatch?.GetLocation() ?? parametersArg.GetLocation()));
}
if (parametersArg.Expression.IsKind(SyntaxKind.NullLiteralExpression) &&
method.Parameters.Length > 0)
{
context.ReportDiagnostic(Diagnostic.Create(REFL025ArgumentsDontMatchParameters.Descriptor, parametersArg.GetLocation()));
}
if (Type.IsCastToWrongType(invocation, method.ReturnType, context, out var castType))
{
context.ReportDiagnostic(
Diagnostic.Create(
REFL028CastReturnValueToCorrectType.Descriptor,
castType.GetLocation(),
ImmutableDictionary <string, string> .Empty.Add(
nameof(TypeSyntax),
method.ReturnType.ToString(context)),
method.ReturnType.ToString(context)));
}
if (invoke.TryFindParameter("obj", out var objParameter) &&
invocation.TryFindArgument(objParameter, out var objArg))
{
if (method.IsStatic &&
objArg.Expression?.IsKind(SyntaxKind.NullLiteralExpression) == false)
{
context.ReportDiagnostic(Diagnostic.Create(REFL030UseCorrectObj.Descriptor, objArg.GetLocation(), $"The method {method} is static and null should be passed as obj."));
}
if (!method.IsStatic)
{
if (objArg.Expression?.IsKind(SyntaxKind.NullLiteralExpression) == true)
{
context.ReportDiagnostic(Diagnostic.Create(REFL030UseCorrectObj.Descriptor, objArg.GetLocation(), $"The method {method} is an instance method and the instance should be passed as obj."));
}
if (context.SemanticModel.TryGetType(objArg.Expression, context.CancellationToken, out var objType) &&
objType != KnownSymbol.Object &&
!objType.IsAssignableTo(method.ContainingType, context.Compilation))
{
context.ReportDiagnostic(Diagnostic.Create(REFL030UseCorrectObj.Descriptor, objArg.GetLocation(), $"Expected an argument of type {method.ContainingType}."));
}
}
}
if (method.IsGenericDefinition())
{
if (values != null &&
values.Length > 0 &&
Array.TryGetAccessibleTypes(values, context, out var types))
{
context.ReportDiagnostic(
Diagnostic.Create(
REFL035DontInvokeGenericDefinition.Descriptor,
invocation.GetNameLocation(),
ImmutableDictionary <string, string> .Empty.Add(
nameof(TypeSyntax),
string.Join(", ", types.Select(x => $"typeof({x.ToString(context)})")))));
}
else
{
context.ReportDiagnostic(Diagnostic.Create(REFL035DontInvokeGenericDefinition.Descriptor, invocation.GetNameLocation()));
}
}
}
else if (GetX.TryGetConstructorInfo(memberAccess, context, out var ctor))
{
if (ReturnValue.ShouldCast(invocation, ctor.ReturnType, context))
{
context.ReportDiagnostic(
Diagnostic.Create(
REFL001CastReturnValue.Descriptor,
invocation.GetLocation(),
ImmutableDictionary <string, string> .Empty.Add(
nameof(TypeSyntax),
ctor.ContainingType.ToString(context)),
ctor.ContainingType.ToString(context)));
}
if (Array.TryGetValues(parametersArg.Expression, context, out var values) &&
Arguments.TryFindFirstMisMatch(ctor.Parameters, values, context, out var misMatch) == true)
{
context.ReportDiagnostic(Diagnostic.Create(REFL025ArgumentsDontMatchParameters.Descriptor, misMatch?.GetLocation() ?? parametersArg.GetLocation()));
}
if (invoke.TryFindParameter("obj", out var objParameter) &&
invocation.TryFindArgument(objParameter, out var objArg))
{
if (objArg.Expression.IsKind(SyntaxKind.NullLiteralExpression))
{
context.ReportDiagnostic(Diagnostic.Create(REFL030UseCorrectObj.Descriptor, objArg.GetLocation(), "Use overload of Invoke without obj parameter."));
}
else
{
if (!IsResultDiscarded(invocation, context))
{
context.ReportDiagnostic(Diagnostic.Create(REFL002DiscardReturnValue.Descriptor, invocation.GetLocation()));
}
if (!context.SemanticModel.TryGetType(objArg.Expression, context.CancellationToken, out var instanceType) ||
(instanceType != KnownSymbol.Object && !instanceType.Equals(ctor.ContainingType)))
{
context.ReportDiagnostic(Diagnostic.Create(REFL030UseCorrectObj.Descriptor, objArg.GetLocation(), $"Use an instance of type {ctor.ContainingType}."));
}
}
}
else
{
if (!ctor.IsStatic &&
Type.IsCastToWrongType(invocation, ctor.ContainingType, context, out var castType))
{
context.ReportDiagnostic(
Diagnostic.Create(
REFL028CastReturnValueToCorrectType.Descriptor,
castType.GetLocation(),
ImmutableDictionary <string, string> .Empty.Add(
nameof(TypeSyntax),
ctor.ContainingType.ToString(context)),
ctor.ContainingType.ToString(context)));
}
}
if (ctor.IsStatic)
{
context.ReportDiagnostic(
Diagnostic.Create(
REFL038PreferRunClassConstructor.Descriptor,
invocation.GetLocation(),
ImmutableDictionary <string, string> .Empty.Add(
nameof(TypeSyntax),
ctor.ContainingType.ToMinimalDisplayString(context.SemanticModel, invocation.SpanStart))));
}
}
}
}
private static bool TryGet(ExpressionSyntax expression, SyntaxNodeAnalysisContext context, PooledSet <ExpressionSyntax> visited, out ITypeSymbol result, out ExpressionSyntax source)
{
switch (expression)
{
case MemberAccessExpressionSyntax memberAccess when memberAccess.Name.Identifier.ValueText == "ReturnType" &&
memberAccess.Expression is InvocationExpressionSyntax invocation &&
GetX.TryMatchGetMethod(invocation, context, out var reflectedMember, out _, out _, out _) &&
reflectedMember.Match == FilterMatch.Single &&
reflectedMember.Symbol is IMethodSymbol method:
source = memberAccess;
result = method.ReturnType;
return(true);
case MemberAccessExpressionSyntax memberAccess when memberAccess.Name.Identifier.ValueText == "FieldType" &&
memberAccess.Expression is InvocationExpressionSyntax invocation &&
GetX.TryMatchGetField(invocation, context, out var reflectedMember, out _, out _) &&
reflectedMember.Match == FilterMatch.Single &&
reflectedMember.Symbol is IFieldSymbol field:
source = memberAccess;
result = field.Type;
return(true);
case MemberAccessExpressionSyntax memberAccess when memberAccess.Name.Identifier.ValueText == "PropertyType" &&
memberAccess.Expression is InvocationExpressionSyntax invocation &&
GetX.TryMatchGetProperty(invocation, context, out var reflectedMember, out _, out _, out _) &&
reflectedMember.Match == FilterMatch.Single &&
reflectedMember.Symbol is IPropertySymbol field:
source = memberAccess;
result = field.Type;
return(true);
case TypeOfExpressionSyntax typeOf:
source = typeOf;
return(context.SemanticModel.TryGetType(typeOf.Type, context.CancellationToken, out result));
case InvocationExpressionSyntax invocation when invocation.ArgumentList is ArgumentListSyntax args &&
args.Arguments.Count == 0 &&
invocation.TryGetMethodName(out var name) &&
name == "GetType":
switch (invocation.Expression)
{
case MemberAccessExpressionSyntax typeAccess:
source = invocation;
if (context.SemanticModel.TryGetType(typeAccess.Expression, context.CancellationToken, out result))
{
if (result is INamedTypeSymbol namedType &&
namedType.ConstructedFrom?.SpecialType == SpecialType.System_Nullable_T)
{
result = namedType.TypeArguments[0];
}
return(true);
}
return(false);
case IdentifierNameSyntax _ when expression.TryFirstAncestor(out TypeDeclarationSyntax containingType):
source = invocation;
return(context.SemanticModel.TryGetSymbol(containingType, context.CancellationToken, out result));
case MemberBindingExpressionSyntax memberBinding when memberBinding.Parent?.Parent is ConditionalAccessExpressionSyntax conditionalAccess:
source = invocation;
return(context.SemanticModel.TryGetType(conditionalAccess.Expression, context.CancellationToken, out result));
}
break;
case InvocationExpressionSyntax candidate when TryMatchTypeGetType(candidate, context, out var typeName, out var ignoreCase):
source = candidate;
result = context.Compilation.GetTypeByMetadataName(typeName, ignoreCase.Value);
return(result != null);
case InvocationExpressionSyntax candidate when TryMatchAssemblyGetType(candidate, context, out var typeName, out var ignoreCase):
source = candidate;
result = Assembly.TryGet(candidate.Expression, context, out var assembly)
? assembly.GetTypeByMetadataName(typeName, ignoreCase.Value)
: null;
return(result != null);
case InvocationExpressionSyntax invocation when invocation.TryGetTarget(KnownSymbol.Type.GetGenericTypeDefinition, context.SemanticModel, context.CancellationToken, out _) &&
invocation.Expression is MemberAccessExpressionSyntax memberAccess &&
TryGet(memberAccess.Expression, context, visited, out var definingType, out _) &&
definingType is INamedTypeSymbol namedType:
source = invocation;
result = namedType.ConstructedFrom;
return(true);
case InvocationExpressionSyntax invocation when GetX.TryMatchGetNestedType(invocation, context, out var reflectedMember, out _, out _):
source = invocation;
result = reflectedMember.Symbol as ITypeSymbol;
return(result != null && reflectedMember.Match == FilterMatch.Single);
case InvocationExpressionSyntax invocation when invocation.TryGetTarget(KnownSymbol.Type.MakeGenericType, context.SemanticModel, context.CancellationToken, out _) &&
invocation.Expression is MemberAccessExpressionSyntax memberAccess &&
TypeArguments.TryCreate(invocation, context, out var typeArguments) &&
typeArguments.TryGetArgumentsTypes(context, out var types):
#pragma warning disable IDISP003 // Dispose previous before re-assigning.
using (visited = visited.IncrementUsage())
#pragma warning restore IDISP003 // Dispose previous before re-assigning.
{
if (visited.Add(invocation) &&
TryGet(memberAccess.Expression, context, visited, out var definition, out _) &&
definition is INamedTypeSymbol namedType)
{
source = invocation;
result = namedType.Construct(types);
return(result != null);
}
}
break;
case ConditionalAccessExpressionSyntax conditionalAccess:
source = conditionalAccess;
return(TryGet(conditionalAccess.WhenNotNull, context, out result, out _));
}
if (expression.IsEither(SyntaxKind.IdentifierName, SyntaxKind.SimpleMemberAccessExpression) &&
context.SemanticModel.TryGetSymbol(expression, context.CancellationToken, out ISymbol local))
{
#pragma warning disable IDISP003 // Dispose previous before re-assigning.
using (visited = visited.IncrementUsage())
#pragma warning restore IDISP003 // Dispose previous before re-assigning.
{
source = null;
result = null;
return(AssignedValue.TryGetSingle(local, context.SemanticModel, context.CancellationToken, out var assignedValue) &&
visited.Add(assignedValue) &&
TryGet(assignedValue, context, visited, out result, out source));
}
}
source = null;
result = null;
return(false);
}