private static LoggerConfiguration GetLoggerConfigurationFromSyntax(CodeRefactoringContext context, SemanticModel semanticModel, List <MemberAccessExpressionSyntax> configurationProperties)
{
var configuration = new LoggerConfiguration();
foreach (var property in configurationProperties)
{
var invokedMethod = property.Ancestors().FirstOrDefault() as MemberAccessExpressionSyntax;
// Just in case we're looking at syntax that has similiar names to LoggerConfiguration (ReadFrom, WriteTo, ...) but isn't related to Serilog
if (invokedMethod == null)
{
continue;
}
if (String.IsNullOrEmpty(invokedMethod?.Name?.ToString()))
{
configuration.AddError("Failed to get name of method", invokedMethod);
continue;
}
string configAction = property.Name.ToString();
if (configAction == "MinimumLevel")
{
string value;
var logLevel = invokedMethod.Name.ToString();
if (logLevel == "Is")
{
// Ask roslyn what's the constant argument value passed to this method
var argument = (invokedMethod?.Parent as InvocationExpressionSyntax)?.ArgumentList?.Arguments.FirstOrDefault();
if (argument == null)
{
configuration.AddError("Can't get parameter value for MinimumLevel.Is(...)", invokedMethod);
continue;
}
var parameter = RoslynHelper.DetermineParameter(argument, semanticModel, false, context.CancellationToken);
if (parameter == null)
{
configuration.AddError("Failed to analyze parameter", argument);
continue;
}
var accessExpression = argument?.Expression as MemberAccessExpressionSyntax;
if (accessExpression == null)
{
configuration.AddError("Failed to analyze parameter", argument);
continue;
}
var constValue = semanticModel.GetConstantValue(accessExpression, context.CancellationToken);
if (!constValue.HasValue)
{
configuration.AddNonConstantError(argument);
continue;
}
long enumIntegralValue;
try
{
enumIntegralValue = Convert.ToInt64(constValue.Value);
}
catch
{
configuration.AddError($"Value {constValue.Value} is not within expected range", argument);
continue;
}
// Roslyn returns enum constant values as integers, convert it back to the enum member name
var enumMember = parameter.Type.GetMembers().OfType <IFieldSymbol>().FirstOrDefault(x => Convert.ToInt64(x.ConstantValue) == enumIntegralValue);
value = enumMember.Name;
}
else if (logLevel == "Override")
{
var arguments = (invokedMethod?.Parent as InvocationExpressionSyntax)?.ArgumentList?.Arguments ?? default(SeparatedSyntaxList <ArgumentSyntax>);
string key = null;
string level = null;
foreach (var argument in arguments)
{
var parameter = RoslynHelper.DetermineParameter(argument, semanticModel, false, context.CancellationToken);
if (parameter == null)
{
configuration.AddError("Failed to analyze parameter", argument);
continue;
}
if (parameter.Name == "source")
{
var constValue = semanticModel.GetConstantValue(argument.Expression, context.CancellationToken);
if (!constValue.HasValue)
{
configuration.AddNonConstantError(argument.Expression);
value = NotAConstantReplacementValue;
continue;
}
key = constValue.Value?.ToString();
}
else if (parameter.Name == "minimumLevel")
{
var constValue = semanticModel.GetConstantValue(argument.Expression, context.CancellationToken);
if (!constValue.HasValue)
{
configuration.AddNonConstantError(argument.Expression);
value = NotAConstantReplacementValue;
continue;
}
var enumMember = parameter.Type.GetMembers().OfType <IFieldSymbol>().FirstOrDefault(x => Convert.ToInt64(x.ConstantValue) == Convert.ToInt64(constValue.Value));
level = enumMember.Name;
}
}
if (key != null && level != null)
{
configuration.MinimumLevelOverrides[key] = level;
}
continue;
}
else if (logLevel == "ControlledBy")
{
var argument = (invokedMethod?.Parent as InvocationExpressionSyntax)?.ArgumentList?.Arguments.FirstOrDefault();
if (argument == null)
{
configuration.AddError("Can't get parameter value for MinimumLevel.ControlledBy(...)", invokedMethod);
continue;
}
var identifier = argument?.Expression as IdentifierNameSyntax;
if (identifier == null)
{
configuration.AddError("Failed to analyze parameter", argument);
continue;
}
TryAddLoggingLevelSwitch(semanticModel, identifier, configuration, context.CancellationToken);
configuration.MinimumLevelControlledBy = "$" + identifier.Identifier.Value;
continue;
}
else if (LogLevels.Contains(logLevel))
{
value = logLevel;
}
else
{
configuration.AddError("Unknown MinimumLevel method", invokedMethod);
continue;
}
configuration.MinimumLevel = value;
}
else if (configAction == "Enrich")
{
if (invokedMethod.Name.ToString() == "WithProperty")
{
var arguments = (invokedMethod?.Parent as InvocationExpressionSyntax)?.ArgumentList?.Arguments ?? default(SeparatedSyntaxList <ArgumentSyntax>);
string key = null;
string value = null;
foreach (var argument in arguments)
{
var parameter = RoslynHelper.DetermineParameter(argument, semanticModel, false, context.CancellationToken);
if (parameter == null)
{
configuration.AddError("Failed to analyze parameter", argument);
continue;
}
if (parameter.Name == "name")
{
var constValue = semanticModel.GetConstantValue(argument.Expression, context.CancellationToken);
if (!constValue.HasValue)
{
configuration.AddNonConstantError(argument.Expression);
value = NotAConstantReplacementValue;
continue;
}
key = constValue.Value?.ToString();
}
else if (parameter.Name == "value")
{
var constValue = semanticModel.GetConstantValue(argument.Expression, context.CancellationToken);
if (!constValue.HasValue)
{
configuration.AddNonConstantError(argument.Expression);
value = NotAConstantReplacementValue;
continue;
}
value = constValue.Value?.ToString();
}
}
if (key != null && value != null)
{
configuration.EnrichWithProperty[key] = value;
}
}
else
{
AddExtensibleMethod(semanticModel, invokedMethod, configuration, configuration.Enrich.Add, context.CancellationToken);
}
}
else if (configAction == "Destructure")
{
AddExtensibleMethod(semanticModel, invokedMethod, configuration, configuration.Destructure.Add, context.CancellationToken);
}
else if (configAction == "Filter")
{
AddExtensibleMethod(semanticModel, invokedMethod, configuration, configuration.Filter.Add, context.CancellationToken);
}
else if (configAction == "WriteTo")
{
AddExtensibleMethod(semanticModel, invokedMethod, configuration, configuration.WriteTo.Add, context.CancellationToken);
}
else if (configAction == "AuditTo")
{
AddExtensibleMethod(semanticModel, invokedMethod, configuration, configuration.AuditTo.Add, context.CancellationToken);
}
}
return(configuration);
}
private static void AddExtensibleMethod(SemanticModel semanticModel, MemberAccessExpressionSyntax invokedMethod, LoggerConfiguration configuration, Action <ExtensibleMethod> addMethod, CancellationToken cancellationToken)
{
var methodSymbol = semanticModel.GetSymbolInfo(invokedMethod).Symbol as IMethodSymbol;
var method = new ExtensibleMethod
{
AssemblyName = methodSymbol?.ContainingAssembly?.Name,
MethodName = invokedMethod.Name.Identifier.ToString()
};
if (String.IsNullOrEmpty(method.AssemblyName))
{
configuration.AddError("Failed to get semantic informations for this method", invokedMethod);
return;
}
// Check for explicitly given type arguments that are not part of the normal arguments
if (methodSymbol.TypeArguments.Length > 0 && methodSymbol.TypeArguments.Length == methodSymbol.TypeParameters.Length)
{
for (int i = 0; i < methodSymbol.TypeArguments.Length; i++)
{
var typeParamter = methodSymbol.TypeParameters[i];
var typeArgument = methodSymbol.TypeArguments[i];
if (methodSymbol.Parameters.Any(x => x.Type == typeParamter))
{
continue;
}
// Synthesize an System.Type argument if a generic version was used
switch (typeParamter.Name)
{
case "TSink": // WriteTo/AuditTo.Sink<TSink>(...)
method.Arguments["sink"] = GetAssemblyQualifiedTypeName(typeArgument);
break;
case "TEnricher": // Enrich.With<TEnricher>()
method.Arguments["enricher"] = GetAssemblyQualifiedTypeName(typeArgument);
break;
case "TFilter": // Filter.With<TFilter>()
method.Arguments["filter"] = GetAssemblyQualifiedTypeName(typeArgument);
break;
case "TDestructuringPolicy": // Destructure.With<TDestructuringPolicy>()
method.Arguments["policy"] = GetAssemblyQualifiedTypeName(typeArgument);
break;
case "TScalar": // Destructure.AsScalar<TScalar>()
method.Arguments["scalarType"] = GetAssemblyQualifiedTypeName(typeArgument);
break;
}
}
}
var arguments = (invokedMethod?.Parent as InvocationExpressionSyntax)?.ArgumentList?.Arguments ?? default(SeparatedSyntaxList <ArgumentSyntax>);
foreach (var argument in arguments)
{
var parameter = RoslynHelper.DetermineParameter(argument, semanticModel, false, cancellationToken);
if (parameter == null)
{
configuration.AddError("Failed to analyze parameter", argument);
continue;
}
string parameterName = parameter.Name;
// Configuration Surrogates
if (method.MethodName == "Sink" && parameterName == "logEventSink") // WriteTo/AuditTo.Sink(ILogEventSink logEventSink, ...)
{
parameterName = "sink"; // Sink(this LoggerSinkConfiguration loggerSinkConfiguration, ILogEventSink sink, LogEventLevel restrictedToMinimumLevel = LevelAlias.Minimum, LoggingLevelSwitch levelSwitch = null)
}
else if (method.MethodName == "With" && parameterName == "filters") // Filter.With(params ILogEventFilter[] filters)
{
parameterName = "filter"; // With(this LoggerFilterConfiguration loggerFilterConfiguration, ILogEventFilter filter)
}
else if (method.MethodName == "With" && parameterName == "destructuringPolicies") // Destructure.With(params IDestructuringPolicy[] destructuringPolicies)
{
parameterName = "policy"; // With(this LoggerDestructuringConfiguration loggerDestructuringConfiguration, IDestructuringPolicy policy)
}
else if (method.MethodName == "With" && parameterName == "enrichers") // Enrich.With(params ILogEventEnricher[] enrichers)
{
parameterName = "enricher"; // With(this LoggerEnrichmentConfiguration loggerEnrichmentConfiguration, ILogEventEnricher enricher)
}
ITypeSymbol type = parameter.Type;
if (parameter.IsParams && type is IArrayTypeSymbol array)
{
type = array.ElementType;
}
if (type.ToString() == "System.Type")
{
method.Arguments[parameterName] = NotAConstantReplacementValue;
var typeofExpression = argument.Expression as TypeOfExpressionSyntax;
if (typeofExpression == null)
{
configuration.AddError("I need a typeof(T) expression for Type arguments", argument.Expression);
continue;
}
var typeInfo = semanticModel.GetTypeInfo(typeofExpression.Type).Type as INamedTypeSymbol;
if (typeInfo == null)
{
configuration.AddError("Failed to get semantic informations for typeof expression", typeofExpression);
return;
}
// generate the assembly qualified name for usage with Type.GetType(string)
string name = GetAssemblyQualifiedTypeName(typeInfo);
method.Arguments[parameterName] = name;
continue;
}
else if (type.TypeKind == TypeKind.Interface || type.TypeKind == TypeKind.Class && type.IsAbstract)
{
method.Arguments[parameterName] = NotAConstantReplacementValue;
var expressionSymbol = semanticModel.GetSymbolInfo(argument.Expression).Symbol;
if (expressionSymbol != null && (expressionSymbol.Kind == SymbolKind.Property || expressionSymbol.Kind == SymbolKind.Field))
{
if (!expressionSymbol.IsStatic)
{
configuration.AddError("Only static fields and properties can be used", argument.Expression);
continue;
}
if (expressionSymbol.DeclaredAccessibility != Accessibility.Public || expressionSymbol is IPropertySymbol property && property.GetMethod.DeclaredAccessibility != Accessibility.Public)
{
configuration.AddError("Fields and properties must be public and properties must have public getters", argument.Expression);
continue;
}
method.Arguments[parameterName] = GetAssemblyQualifiedTypeName(expressionSymbol.ContainingType, "::" + expressionSymbol.Name);
continue;
}
var objectCreation = argument.Expression as ObjectCreationExpressionSyntax;
if (objectCreation == null)
{
configuration.AddError("I can only infer types from `new T()` expressions", argument.Expression);
continue;
}
// check if there are explicit arguments which are unsupported
if (objectCreation.ArgumentList?.Arguments.Count > 0)
{
configuration.AddError("The configuration supports only parameterless constructors for interface or abstract type parameters", argument.Expression);
continue;
}
var typeInfo = semanticModel.GetTypeInfo(objectCreation).Type as INamedTypeSymbol;
if (typeInfo == null)
{
configuration.AddError("Failed to get semantic informations for this constructor", objectCreation);
return;
}
// generate the assembly qualified name for usage with Type.GetType(string)
string name = GetAssemblyQualifiedTypeName(typeInfo);
method.Arguments[parameterName] = name;
continue;
}
else if (type.ToString() == "Serilog.Core.LoggingLevelSwitch")
{
var identifier = argument?.Expression as IdentifierNameSyntax;
if (identifier == null)
{
configuration.AddError("Failed to analyze parameter", argument);
continue;
}
TryAddLoggingLevelSwitch(semanticModel, identifier, configuration, cancellationToken);
method.Arguments[parameterName] = "$" + identifier.Identifier.Value;
continue;
}
string value = null;
var constValue = semanticModel.GetConstantValue(argument.Expression, cancellationToken);
if (!constValue.HasValue)
{
configuration.AddNonConstantError(argument.Expression);
value = NotAConstantReplacementValue;
}
else
{
if (type.TypeKind == TypeKind.Enum)
{
var enumMember = type.GetMembers().OfType <IFieldSymbol>().FirstOrDefault(x => Convert.ToInt64(x.ConstantValue) == Convert.ToInt64(constValue.Value));
value = enumMember.Name;
}
else
{
value = constValue.Value?.ToString();
}
}
method.Arguments[parameterName] = value;
}
addMethod(method);
}
private static void TryAddLoggingLevelSwitch(SemanticModel semanticModel, IdentifierNameSyntax identifier, LoggerConfiguration configuration, CancellationToken cancellationToken)
{
string name = "$" + identifier.Identifier.Value;
if (configuration.LevelSwitches.ContainsKey(name))
{
return;
}
var symbol = semanticModel.GetSymbolInfo(identifier, cancellationToken).Symbol;
if (symbol == null)
{
configuration.AddError("Failed to analyze parameter", identifier);
return;
}
var reference = symbol.DeclaringSyntaxReferences.FirstOrDefault() as SyntaxReference;
if (reference == null)
{
configuration.AddError("Could not find declaration of LoggingLevelSwitch", identifier);
return;
}
var declarator = reference.GetSyntax(cancellationToken) as VariableDeclaratorSyntax;
if (declarator == null)
{
configuration.AddError("Could not find declaration of LoggingLevelSwitch", identifier);
return;
}
var initializer = declarator.Initializer.Value as ObjectCreationExpressionSyntax;
if (initializer == null)
{
configuration.AddError("Could not find initialization of LoggingLevelSwitch", identifier);
return;
}
IParameterSymbol parameter;
object value;
var argument = initializer.ArgumentList.Arguments.FirstOrDefault();
if (argument == null)
{
var constructor = semanticModel.GetSymbolInfo(initializer, cancellationToken).Symbol;
if (constructor == null)
{
configuration.AddError("Could not analyze LoggingLevelSwitch constructor", identifier);
return;
}
parameter = (symbol as IMethodSymbol)?.Parameters.FirstOrDefault();
if (parameter == null)
{
configuration.AddError("Could not analyze LoggingLevelSwitch constructor", identifier);
return;
}
value = parameter.ExplicitDefaultValue;
}
else
{
parameter = RoslynHelper.DetermineParameter(argument, semanticModel, false, cancellationToken);
if (parameter == null)
{
configuration.AddError("Failed to analyze parameter", argument);
return;
}
var constValue = semanticModel.GetConstantValue(argument.Expression, cancellationToken);
if (!constValue.HasValue)
{
configuration.AddNonConstantError(argument);
return;
}
value = constValue.Value;
}
long enumIntegralValue;
try
{
enumIntegralValue = Convert.ToInt64(value);
}
catch
{
configuration.AddError($"Value {value} is not within expected range", argument);
return;
}
// Roslyn returns enum constant values as integers, convert it back to the enum member name
var enumMember = parameter.Type.GetMembers().OfType <IFieldSymbol>().FirstOrDefault(x => Convert.ToInt64(x.ConstantValue) == enumIntegralValue);
configuration.LevelSwitches.Add(name, enumMember.Name);
}
private static void AddExtensibleMethod(SemanticModel semanticModel, MemberAccessExpressionSyntax invokedMethod, LoggerConfiguration configuration, Action <ExtensibleMethod> addMethod, CancellationToken cancellationToken)
{
var method = new ExtensibleMethod
{
AssemblyName = semanticModel.GetSymbolInfo(invokedMethod).Symbol?.ContainingAssembly?.Name,
MethodName = invokedMethod.Name.ToString()
};
if (String.IsNullOrEmpty(method.AssemblyName))
{
configuration.AddError("Failed to get semantic informations for this method", invokedMethod);
return;
}
var arguments = (invokedMethod?.Parent as InvocationExpressionSyntax)?.ArgumentList?.Arguments ?? default(SeparatedSyntaxList <ArgumentSyntax>);
foreach (var argument in arguments)
{
var parameter = RoslynHelper.DetermineParameter(argument, semanticModel, false, cancellationToken);
if (parameter == null)
{
configuration.AddError("Failed to analyze parameter", argument);
continue;
}
if (parameter.Type?.TypeKind == TypeKind.Interface)
{
method.Arguments[parameter.Name] = NotAConstantReplacementValue;
var objectCreation = argument.Expression as ObjectCreationExpressionSyntax;
if (objectCreation == null)
{
configuration.AddError("I can only infer types from `new T()` expressions", argument.Expression);
continue;
}
// check if there are explicit arguments which are unsupported
if (objectCreation.ArgumentList?.Arguments.Count > 0)
{
configuration.AddError("The configuration supports only parameterless constructors for interface parameters", argument.Expression);
continue;
}
var typeInfo = semanticModel.GetTypeInfo(objectCreation).Type as INamedTypeSymbol;
if (typeInfo == null)
{
configuration.AddError("Failed to get semantic informations for this constructor", objectCreation);
return;
}
// generate the assembly qualified name for usage with Type.GetType(string)
string name = GetAssemblyQualifiedTypeName(typeInfo);
method.Arguments[parameter.Name] = name;
continue;
}
string value = null;
var constValue = semanticModel.GetConstantValue(argument.Expression, cancellationToken);
if (!constValue.HasValue)
{
configuration.AddNonConstantError(argument.Expression);
value = NotAConstantReplacementValue;
}
else
{
if (parameter.Type.TypeKind == TypeKind.Enum)
{
var enumMember = parameter.Type.GetMembers().OfType <IFieldSymbol>().FirstOrDefault(x => Convert.ToInt64(x.ConstantValue) == Convert.ToInt64(constValue.Value));
value = enumMember.Name;
}
else
{
value = constValue.Value?.ToString();
}
}
method.Arguments[parameter.Name] = value;
}
addMethod(method);
}