// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Microsoft.CodeAnalysis;

namespace Microsoft.Interop
{
    public static class CompilationExtensions
    {
        public static EnvironmentFlags GetEnvironmentFlags(this Compilation compilation)
        {
            EnvironmentFlags flags = EnvironmentFlags.None;
            if (compilation.SourceModule.GetAttributes().Any(attr => attr.AttributeClass.ToDisplayString() == TypeNames.System_Runtime_CompilerServices_SkipLocalsInitAttribute))
            {
                flags |= EnvironmentFlags.SkipLocalsInit;
            }
            if (compilation.Assembly.GetAttributes().Any(attr => attr.AttributeClass.ToDisplayString() == TypeNames.System_Runtime_CompilerServices_DisableRuntimeMarshallingAttribute))
            {
                flags |= EnvironmentFlags.DisableRuntimeMarshalling;
            }
            // Roslyn does not expose the memory safety rules version through a public API yet
            // (https://github.com/dotnet/roslyn/issues/82546), so the same feature flag the compiler itself
            // reads is used. Parse options are per-project, so any tree answers for the whole compilation.
            if (compilation.SyntaxTrees.FirstOrDefault()?.Options.Features.ContainsKey("updated-memory-safety-rules") == true)
            {
                flags |= EnvironmentFlags.UpdatedMemorySafetyRules;
            }
            return flags;
        }
    }
}