public void OnVisitSyntaxNode(GeneratorSyntaxContext context)
{
if (this.ProjectDirectory == null && context.Node is ClassDeclarationSyntax)
{
var templateFinder = new CloudFormationTemplateFinder(_fileManager, _directoryManager);
this.ProjectDirectory = templateFinder.DetermineProjectRootDirectory(context.Node.SyntaxTree.FilePath);
}
// any method with at least one attribute is a candidate of function generation
if (context.Node is MethodDeclarationSyntax methodDeclarationSyntax && methodDeclarationSyntax.AttributeLists.Count > 0)
{
// Get the symbol being declared by the method, and keep it if its annotated
var methodSymbol = context.SemanticModel.GetDeclaredSymbol(methodDeclarationSyntax);
if (methodSymbol.GetAttributes().Any(attr => attr.AttributeClass.Name == nameof(LambdaFunctionAttribute)))
{
LambdaMethods.Add(methodDeclarationSyntax);
}
}
// any class with at least one attribute is a candidate of Startup class
if (context.Node is ClassDeclarationSyntax classDeclarationSyntax && classDeclarationSyntax.AttributeLists.Count > 0)
{
// Get the symbol being declared by the class, and keep it if its annotated
var methodSymbol = context.SemanticModel.GetDeclaredSymbol(classDeclarationSyntax);
if (methodSymbol.GetAttributes().Any(attr => attr.AttributeClass.Name == nameof(LambdaStartupAttribute)))
{
StartupClasses.Add(classDeclarationSyntax);
}
}
}
public void Execute(GeneratorExecutionContext context)
{
var diagnosticReporter = new DiagnosticReporter(context);
try
{
// retrieve the populated receiver
if (!(context.SyntaxContextReceiver is SyntaxReceiver receiver))
{
return;
}
// If no project directory was detected then skip the generator.
// This is most likely to happen when the project is empty and doesn't have any classes in it yet.
if (string.IsNullOrEmpty(receiver.ProjectDirectory))
{
return;
}
var semanticModelProvider = new SemanticModelProvider(context);
if (receiver.StartupClasses.Count > 1)
{
foreach (var startup in receiver.StartupClasses)
{
// If there are more than one startup class, report them as errors
diagnosticReporter.Report(Diagnostic.Create(DiagnosticDescriptors.MultipleStartupNotAllowed,
Location.Create(startup.SyntaxTree, startup.Span),
startup.SyntaxTree.FilePath));
}
}
var configureMethodModel = semanticModelProvider.GetConfigureMethodModel(receiver.StartupClasses.FirstOrDefault());
var annotationReport = new AnnotationReport();
var templateFinder = new CloudFormationTemplateFinder(_fileManager, _directoryManager);
foreach (var lambdaMethod in receiver.LambdaMethods)
{
var lambdaMethodModel = semanticModelProvider.GetMethodSemanticModel(lambdaMethod);
// Check for necessary references
if (lambdaMethodModel.HasAttribute(context, TypeFullNames.RestApiAttribute) ||
lambdaMethodModel.HasAttribute(context, TypeFullNames.HttpApiAttribute))
{
// Check for arbitrary type from "Amazon.Lambda.APIGatewayEvents"
if (context.Compilation.ReferencedAssemblyNames.FirstOrDefault(x => x.Name == "Amazon.Lambda.APIGatewayEvents") == null)
{
diagnosticReporter.Report(Diagnostic.Create(DiagnosticDescriptors.MissingDependencies,
lambdaMethod.GetLocation(),
"Amazon.Lambda.APIGatewayEvents"));
}
}
var model = LambdaFunctionModelBuilder.Build(lambdaMethodModel, configureMethodModel, context);
// If there are more than one event, report them as errors
if (model.LambdaMethod.Events.Count > 1)
{
foreach (var attribute in lambdaMethodModel.GetAttributes().Where(attribute => TypeFullNames.Events.Contains(attribute.AttributeClass.ToDisplayString())))
{
diagnosticReporter.Report(Diagnostic.Create(DiagnosticDescriptors.MultipleEventsNotSupported,
Location.Create(attribute.ApplicationSyntaxReference.SyntaxTree, attribute.ApplicationSyntaxReference.Span),
DiagnosticSeverity.Error));
}
// Skip multi-event lambda method from processing and check remaining lambda methods for diagnostics
continue;
}
var template = new LambdaFunctionTemplate(model);
var sourceText = template.TransformText().ToEnvironmentLineEndings();
context.AddSource($"{model.GeneratedMethod.ContainingType.Name}.g.cs", SourceText.From(sourceText, Encoding.UTF8, SourceHashAlgorithm.Sha256));
// report every generated file to build output
diagnosticReporter.Report(Diagnostic.Create(DiagnosticDescriptors.CodeGeneration, Location.None, $"{model.GeneratedMethod.ContainingType.Name}.g.cs", sourceText));
annotationReport.LambdaFunctions.Add(model);
}
// Run the CloudFormation sync if any LambdaMethods exists. Also run if no LambdaMethods exists but there is a
// CloudFormation template in case orphaned functions in the template need to be removed.
// Both checks are required because if there is no template but there are LambdaMethods the CF template the template will be created.
if (receiver.LambdaMethods.Any() || templateFinder.DoesCloudFormationTemplateExist(receiver.ProjectDirectory))
{
annotationReport.CloudFormationTemplatePath = templateFinder.FindCloudFormationTemplate(receiver.ProjectDirectory);
annotationReport.ProjectRootDirectory = receiver.ProjectDirectory;
var cloudFormationJsonWriter = new CloudFormationJsonWriter(_fileManager, _directoryManager, _jsonWriter, diagnosticReporter);
cloudFormationJsonWriter.ApplyReport(annotationReport);
}
}
catch (Exception e)
{
// this is a generator failure, report this as error
diagnosticReporter.Report(Diagnostic.Create(DiagnosticDescriptors.UnhandledException, Location.None, e.PrettyPrint()));
#if DEBUG
throw;
#endif
}
}