private static void GenType(EventSourceClass ec, StringBuilder sb)
{
if (!string.IsNullOrWhiteSpace(ec.Namespace))
{
sb.AppendLine($@"
namespace {ec.Namespace}
{{");
}
sb.AppendLine($@"
{s_generatedCodeAttribute}
partial class {ec.ClassName}
{{");
GenerateConstructor(ec, sb);
GenerateProviderMetadata(ec.SourceName, sb);
sb.AppendLine($@"
}}");
if (!string.IsNullOrWhiteSpace(ec.Namespace))
{
sb.AppendLine($@"
}}");
}
}
private void GenType(EventSourceClass ec)
{
if (!string.IsNullOrWhiteSpace(ec.Namespace))
{
_builder.AppendLine($@"
namespace {ec.Namespace}
{{");
}
_builder.AppendLine($@"
partial class {ec.ClassName}
{{");
GenerateConstructor(ec);
GenerateProviderMetadata(ec.SourceName);
_builder.AppendLine($@"
}}");
if (!string.IsNullOrWhiteSpace(ec.Namespace))
{
_builder.AppendLine($@"
}}");
}
}
private static void EmitSourceFile(SourceProductionContext context, EventSourceClass ec)
{
StringBuilder sb = new StringBuilder(1024);
sb.AppendLine(@"// <auto-generated/>");
sb.AppendLine();
sb.AppendLine("using System;");
GenType(ec, sb);
context.AddSource($"{ec.ClassName}.g.cs", SourceText.From(sb.ToString(), Encoding.UTF8));
}
public EventSourceClass[] GetEventSourceClasses(List <ClassDeclarationSyntax> classDeclarations)
{
INamedTypeSymbol?autogenerateAttribute = _compilation.GetTypeByMetadataName("System.Diagnostics.Tracing.EventSourceAutoGenerateAttribute");
if (autogenerateAttribute is null)
{
// No EventSourceAutoGenerateAttribute
return(Array.Empty <EventSourceClass>());
}
INamedTypeSymbol?eventSourceAttribute = _compilation.GetTypeByMetadataName("System.Diagnostics.Tracing.EventSourceAttribute");
if (eventSourceAttribute is null)
{
// No EventSourceAttribute
return(Array.Empty <EventSourceClass>());
}
List <EventSourceClass>?results = null;
// we enumerate by syntax tree, to minimize the need to instantiate semantic models (since they're expensive)
foreach (IGrouping <SyntaxTree, ClassDeclarationSyntax>?group in classDeclarations.GroupBy(x => x.SyntaxTree))
{
SemanticModel? sm = null;
EventSourceClass?eventSourceClass = null;
foreach (ClassDeclarationSyntax?classDef in group)
{
if (_cancellationToken.IsCancellationRequested)
{
// be nice and stop if we're asked to
return(results?.ToArray() ?? Array.Empty <EventSourceClass>());
}
bool autoGenerate = false;
foreach (AttributeListSyntax?cal in classDef.AttributeLists)
{
foreach (AttributeSyntax?ca in cal.Attributes)
{
// need a semantic model for this tree
sm ??= _compilation.GetSemanticModel(classDef.SyntaxTree);
if (sm.GetSymbolInfo(ca, _cancellationToken).Symbol is not IMethodSymbol caSymbol)
{
// badly formed attribute definition, or not the right attribute
continue;
}
if (autogenerateAttribute.Equals(caSymbol.ContainingType, SymbolEqualityComparer.Default))
{
autoGenerate = true;
continue;
}
if (eventSourceAttribute.Equals(caSymbol.ContainingType, SymbolEqualityComparer.Default))
{
string nspace = string.Empty;
NamespaceDeclarationSyntax?ns = classDef.Parent as NamespaceDeclarationSyntax;
if (ns is null)
{
if (classDef.Parent is not CompilationUnitSyntax)
{
// since this generator doesn't know how to generate a nested type...
continue;
}
}
else
{
nspace = ns.Name.ToString();
while (true)
{
ns = ns.Parent as NamespaceDeclarationSyntax;
if (ns == null)
{
break;
}
nspace = $"{ns.Name}.{nspace}";
}
}
string className = classDef.Identifier.ToString();
string name = className;
string guid = "";
SeparatedSyntaxList <AttributeArgumentSyntax>?args = ca.ArgumentList?.Arguments;
if (args is not null)
{
foreach (AttributeArgumentSyntax?arg in args)
{
string?argName = arg.NameEquals !.Name.Identifier.ToString();
string?value = sm.GetConstantValue(arg.Expression, _cancellationToken).ToString();
switch (argName)
{
case "Guid":
guid = value;
break;
case "Name":
name = value;
break;
}
}
}
if (!Guid.TryParse(guid, out Guid result))
{
result = GenerateGuidFromName(name.ToUpperInvariant());
}
eventSourceClass = new EventSourceClass
{
Namespace = nspace,
ClassName = className,
SourceName = name,
Guid = result
};
continue;
}
}
}
if (!autoGenerate)
{
continue;
}
if (eventSourceClass is null)
{
continue;
}
results ??= new List <EventSourceClass>();
results.Add(eventSourceClass);
}
}
return(results?.ToArray() ?? Array.Empty <EventSourceClass>());
}
private static void GenerateConstructor(EventSourceClass ec, StringBuilder sb)
{
sb.AppendLine($@"
private {ec.ClassName}() : base(new Guid({ec.Guid.ToString("x").Replace("{", "").Replace("}", "")}), ""{ec.SourceName}"") {{ }}");
}
private static EventSourceClass?GetSemanticTargetForGeneration(GeneratorAttributeSyntaxContext context, CancellationToken cancellationToken)
{
const string EventSourceAttribute = "System.Diagnostics.Tracing.EventSourceAttribute";
var classDef = (ClassDeclarationSyntax)context.TargetNode;
NamespaceDeclarationSyntax?ns = classDef.Parent as NamespaceDeclarationSyntax;
if (ns is null)
{
if (classDef.Parent is not CompilationUnitSyntax)
{
// since this generator doesn't know how to generate a nested type...
return(null);
}
}
EventSourceClass?eventSourceClass = null;
string? nspace = null;
foreach (AttributeData attribute in context.TargetSymbol.GetAttributes())
{
if (attribute.AttributeClass?.Name != "EventSourceAttribute" ||
attribute.AttributeClass.ToDisplayString() != EventSourceAttribute)
{
continue;
}
nspace ??= ConstructNamespace(ns);
string className = classDef.Identifier.ValueText;
string name = className;
string guid = "";
ImmutableArray <KeyValuePair <string, TypedConstant> > args = attribute.NamedArguments;
foreach (KeyValuePair <string, TypedConstant> arg in args)
{
string argName = arg.Key;
string value = arg.Value.Value?.ToString();
switch (argName)
{
case "Guid":
guid = value;
break;
case "Name":
name = value;
break;
}
}
if (!Guid.TryParse(guid, out Guid result))
{
result = GenerateGuidFromName(name.ToUpperInvariant());
}
eventSourceClass = new EventSourceClass(nspace, className, name, result);
continue;
}
return(eventSourceClass);
}