private static void CheckDelegateCreation()

in ClrHeapAllocationsAnalyzer/TypeConversionAllocationAnalyzer.cs [255:309]
51 lines of code
15 McCabe index (conditional complexity)

        private static void CheckDelegateCreation(SyntaxNode node, TypeInfo typeInfo, SemanticModel semanticModel, bool isAssignmentToReadonly, Action<Diagnostic> reportDiagnostic, Location location, string filePath, CancellationToken cancellationToken)
        {
            // special case: method groups
            if (typeInfo.ConvertedType?.TypeKind == TypeKind.Delegate)
            {
                // new Action<Foo>(MethodGroup); should skip this one
                var insideObjectCreation = node?.Parent?.Parent?.Parent?.Kind() == SyntaxKind.ObjectCreationExpression;
                if (node is ParenthesizedLambdaExpressionSyntax || node is SimpleLambdaExpressionSyntax ||
                    node is AnonymousMethodExpressionSyntax || node is ObjectCreationExpressionSyntax ||
                    insideObjectCreation)
                {
                    // skip this, because it's intended.
                }
                else
                {
                    if (node.IsKind(SyntaxKind.IdentifierName))
                    {
                        if (semanticModel.GetSymbolInfo(node, cancellationToken).Symbol is IMethodSymbol) {
                            reportDiagnostic(Diagnostic.Create(MethodGroupAllocationRule, location, EmptyMessageArgs));
                            HeapAllocationAnalyzerEventSource.Logger.MethodGroupAllocation(filePath);
                        }
                    }
                    else if (node.IsKind(SyntaxKind.SimpleMemberAccessExpression))
                    {
                        var memberAccess = node as MemberAccessExpressionSyntax;
                        if (semanticModel.GetSymbolInfo(memberAccess.Name, cancellationToken).Symbol is IMethodSymbol)
                        {
                            if (isAssignmentToReadonly)
                            {
                                reportDiagnostic(Diagnostic.Create(ReadonlyMethodGroupAllocationRule, location, EmptyMessageArgs));
                                HeapAllocationAnalyzerEventSource.Logger.ReadonlyMethodGroupAllocation(filePath);
                            }
                            else
                            {
                                reportDiagnostic(Diagnostic.Create(MethodGroupAllocationRule, location, EmptyMessageArgs));
                                HeapAllocationAnalyzerEventSource.Logger.MethodGroupAllocation(filePath);
                            }
                        }
                    } 
                    else if (node is ArrowExpressionClauseSyntax)
                    {
                        var arrowClause = node as ArrowExpressionClauseSyntax;
                        if (semanticModel.GetSymbolInfo(arrowClause.Expression, cancellationToken).Symbol is IMethodSymbol) {
                            reportDiagnostic(Diagnostic.Create(MethodGroupAllocationRule, location, EmptyMessageArgs));
                            HeapAllocationAnalyzerEventSource.Logger.MethodGroupAllocation(filePath);
                        }
                    }
                }

                if (IsStructInstanceMethod(node, semanticModel, cancellationToken))
                {
                    reportDiagnostic(Diagnostic.Create(DelegateOnStructInstanceRule, location, EmptyMessageArgs));
                }
            }
        }