// Licensed to the .NET Foundation under one or more agreements. // The .NET Foundation licenses this file to you under the MIT license. // See the LICENSE file in the project root for more information. using System.Diagnostics.CodeAnalysis; using System.Linq; using Microsoft.CodeAnalysis.Shared.Extensions; using Roslyn.Utilities; namespace Microsoft.CodeAnalysis.Simplification; internal static class SimplificationHelpers { public static readonly SyntaxAnnotation DoNotSimplifyAnnotation = new(); public static readonly SyntaxAnnotation SimplifyModuleNameAnnotation = new(); public static TNode CopyAnnotations<TNode>(SyntaxNode from, TNode to) where TNode : SyntaxNode { // Because we are removing a node that may have annotations (i.e. formatting), we need // to copy those annotations to the new node. However, we can only copy all annotations // which will mean that the new node will include a ParenthesesSimplification annotation, // even if didn't have one before. That results in potentially removing parentheses that // weren't annotated by the user. To address this, we add *another* annotation to indicate // that the new node shouldn't be simplified. This is to work around the // fact that there is no way to remove an annotation from a node in the current API. If // that gets added, we can clean this up. var dontSimplifyResult = !to.HasAnnotation(Simplifier.Annotation); to = from.CopyAnnotationsTo(to); if (dontSimplifyResult) { to = to.WithAdditionalAnnotations(DoNotSimplifyAnnotation); } return to; } public static SyntaxToken CopyAnnotations(SyntaxToken from, SyntaxToken to) { // Because we are removing a node that may have annotations (i.e. formatting), we need // to copy those annotations to the new node. However, we can only copy all annotations // which will mean that the new node will include a ParenthesesSimplification annotation, // even if didn't have one before. That results in potentially removing parentheses that // weren't annotated by the user. To address this, we add *another* annotation to indicate // that the new node shouldn't be simplified. This is to work around the // fact that there is no way to remove an annotation from a node in the current API. If // that gets added, we can clean this up. var dontSimplifyResult = !to.HasAnnotation(Simplifier.Annotation); to = from.CopyAnnotationsTo(to); if (dontSimplifyResult) { to = to.WithAdditionalAnnotations(DoNotSimplifyAnnotation); } return to; } public static ISymbol? GetOriginalSymbolInfo(SemanticModel semanticModel, SyntaxNode expression) { Contract.ThrowIfNull(expression); var annotation1 = expression.GetAnnotations(SymbolAnnotation.Kind).FirstOrDefault(); if (annotation1 != null) { var typeSymbol = SymbolAnnotation.GetSymbol(annotation1, semanticModel.Compilation); if (IsValidSymbolInfo(typeSymbol)) return typeSymbol; } var annotation2 = expression.GetAnnotations(SpecialTypeAnnotation.Kind).FirstOrDefault(); if (annotation2 != null) { var specialType = SpecialTypeAnnotation.GetSpecialType(annotation2); if (specialType != SpecialType.None) { var typeSymbol = semanticModel.Compilation.GetSpecialType(specialType); if (IsValidSymbolInfo(typeSymbol)) return typeSymbol; } } var symbolInfo = semanticModel.GetSymbolInfo(expression); if (!IsValidSymbolInfo(symbolInfo.Symbol)) return null; return symbolInfo.Symbol; } public static bool IsValidSymbolInfo([NotNullWhen(true)] ISymbol? symbol) { // name bound to only one symbol is valid return symbol is not null and not IErrorTypeSymbol; } public static bool IsNamespaceOrTypeOrThisParameter(SyntaxNode expression, SemanticModel semanticModel) { var expressionInfo = semanticModel.GetSymbolInfo(expression); if (IsValidSymbolInfo(expressionInfo.Symbol)) { if (expressionInfo.Symbol is INamespaceOrTypeSymbol) return true; if (expressionInfo.Symbol.IsThisParameter()) return true; } return false; } internal static bool ShouldSimplifyThisOrMeMemberAccessExpression(SimplifierOptions options, ISymbol symbol) { // If we're accessing a static member off of this/me then we should always consider this // simplifiable. Note: in C# this isn't even legal to access a static off of `this`, // but in VB it is legal to access a static off of `me`. if (symbol.IsStatic) return true; return options.TryGetQualifyMemberAccessOption(symbol.Kind, out var symbolOptions) && !symbolOptions.Value; } } |