ET/Share/Analyzer/Extension/AnalyzerHelper.cs

using System.Linq;
using Microsoft.CodeAnalysis;
using Microsoft.CodeAnalysis.CSharp.Syntax;

namespace ET.Analyzer
{
    public static class AnalyzerHelper
    {
        /// <summary>
        ///     获取语法树节点的子节点中第一个指定类型节点
        /// </summary>
        /// <param name="syntaxNode">语法树节点</param>
        /// <typeparam name="T">指定语法节点类型</typeparam>
        /// <returns>第一个指定类型节点</returns>
        public static T? GetFirstChild<T>(this SyntaxNode syntaxNode) where T : SyntaxNode
        {
            foreach (SyntaxNode? childNode in syntaxNode.ChildNodes())
            {
                if (childNode.GetType() == typeof (T))
                {
                    return childNode as T;
                }
            }

            return null;
        }

        public static SyntaxNode? GetFirstChild(this SyntaxNode syntaxNode)
        {
            var childNodes = syntaxNode.ChildNodes();
            if (childNodes.Count() > 0)
            {
                return childNodes.First();
            }

            return null;
        }

        /// <summary>
        ///     获取语法树节点的子节点中最后一个指定类型节点
        /// </summary>
        /// <param name="syntaxNode">语法树节点</param>
        /// <typeparam name="T">指定语法节点类型</typeparam>
        /// <returns>最后一个指定类型节点</returns>
        public static T? GetLastChild<T>(this SyntaxNode syntaxNode) where T : SyntaxNode
        {
            foreach (SyntaxNode? childNode in syntaxNode.ChildNodes().Reverse())
            {
                if (childNode.GetType() == typeof (T))
                {
                    return childNode as T;
                }
            }

            return null;
        }

        /// <summary>
        ///     获取语法节点所属的ClassDeclarationSyntax
        /// </summary>
        public static ClassDeclarationSyntax? GetParentClassDeclaration(this SyntaxNode syntaxNode)
        {
            SyntaxNode? parentNode = syntaxNode.Parent;
            while (parentNode != null)
            {
                if (parentNode is ClassDeclarationSyntax classDeclarationSyntax)
                {
                    return classDeclarationSyntax;
                }

                parentNode = parentNode.Parent;
            }

            return null;
        }

        /// <summary>
        ///     INamedTypeSymbol 是否有指定的Attribute
        /// </summary>
        public static bool HasAttribute(this INamedTypeSymbol namedTypeSymbol, string AttributeName)
        {
            foreach (AttributeData? attributeData in namedTypeSymbol.GetAttributes())
            {
                if (attributeData.AttributeClass?.ToString() == AttributeName)
                {
                    return true;
                }
            }

            return false;
        }

        /// <summary>
        ///     INamedTypeSymbol 是否有指定的基类Attribute
        /// </summary>
        public static bool HasBaseAttribute(this INamedTypeSymbol namedTypeSymbol, string AttributeName)
        {
            foreach (AttributeData? attributeData in namedTypeSymbol.GetAttributes())
            {
                INamedTypeSymbol? attributeType = attributeData.AttributeClass?.BaseType;
                while (attributeType != null)
                {
                    if (attributeType.ToString() == AttributeName)
                    {
                        return true;
                    }

                    attributeType = attributeType.BaseType;
                }
            }

            return false;
        }

        /// <summary>
        ///     INamedTypeSymbol 获取指定类型的第一个Attribute
        /// </summary>
        public static AttributeData? GetFirstAttribute(this INamedTypeSymbol namedTypeSymbol, string AttributeName)
        {
            foreach (AttributeData? attributeData in namedTypeSymbol.GetAttributes())
            {
                if (attributeData.AttributeClass?.ToString() == AttributeName)
                {
                    return attributeData;
                }
            }

            return null;
        }

        /// <summary>
        ///     INamedTypeSymbol 是否含有指定接口
        /// </summary>
        public static bool HasInterface(this INamedTypeSymbol namedTypeSymbol, string InterfaceName)
        {
            foreach (INamedTypeSymbol? iInterface in namedTypeSymbol.AllInterfaces)
            {
                if (iInterface.ToString() == InterfaceName)
                {
                    return true;
                }
            }

            return false;
        }

        /// <summary>
        ///     判断指定的程序集是否需要分析
        /// </summary>
        public static bool IsAssemblyNeedAnalyze(string? assemblyName, params string[] analyzeAssemblyNames)
        {
            if (assemblyName == null)
            {
                return false;
            }

            foreach (string analyzeAssemblyName in analyzeAssemblyNames)
            {
                if (assemblyName == analyzeAssemblyName)
                {
                    return true;
                }
            }

            return false;
        }

        /// <summary>
        /// 获取 成员访问语法节点的父级类型
        /// </summary>
        public static ITypeSymbol? GetMemberAccessSyntaxParentType(this MemberAccessExpressionSyntax memberAccessExpressionSyntax,
        SemanticModel semanticModel)
        {
            SyntaxNode? firstChildSyntaxNode = memberAccessExpressionSyntax.GetFirstChild();
            if (firstChildSyntaxNode == null)
            {
                return null;
            }

            ISymbol? firstChildSymbol = semanticModel.GetSymbolInfo(firstChildSyntaxNode).Symbol;
            if (firstChildSymbol == null)
            {
                return null;
            }

            if (firstChildSymbol is ILocalSymbol localSymbol)
            {
                return localSymbol.Type;
            }

            if (firstChildSymbol is IParameterSymbol parameterSymbol)
            {
                return parameterSymbol.Type;
            }

            if (firstChildSymbol is IPropertySymbol propertySymbol)
            {
                return propertySymbol.Type;
            }

            if (firstChildSymbol is IMethodSymbol methodSymbol)
            {
                return methodSymbol.ReturnType;
            }

            if (firstChildSymbol is IFieldSymbol fieldSymbol)
            {
                return fieldSymbol.Type;
            }

            if (firstChildSymbol is IEventSymbol eventSymbol)
            {
                return eventSymbol.Type;
            }

            return null;
        }
        
        /// <summary>
        /// 获取最近的指定类型祖先节点
        /// </summary>
        public static T? GetNeareastAncestor<T>(this SyntaxNode syntaxNode) where T:SyntaxNode
        {
            
            foreach (var ancestorNode in syntaxNode.Ancestors())
            {
                if (ancestorNode is T Tancestor)
                {
                    return Tancestor;
                }
            }
            return null ;
        }
    }
}