// 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.
 
namespace Microsoft.CodeAnalysis;
 
internal partial struct SymbolKey
{
    private sealed class PreprocessingSymbolKey : AbstractSymbolKey<IPreprocessingSymbol>
    {
        public static readonly PreprocessingSymbolKey Instance = new();
 
        public sealed override void Create(IPreprocessingSymbol symbol, SymbolKeyWriter visitor)
            => visitor.WriteString(symbol.Name);
 
        protected sealed override SymbolKeyResolution Resolve(SymbolKeyReader reader, IPreprocessingSymbol? contextualSymbol, out string? failureReason)
        {
#if !ROSLYN_4_12_OR_LOWER
            failureReason = null;
            return new SymbolKeyResolution(reader.Compilation.CreatePreprocessingSymbol(reader.ReadRequiredString()));
#else
            failureReason = "Preprocessing symbols are not supported in this version of Roslyn.";
            return default;
#endif
        }
    }
}