// Copyright (c) .NET Foundation and contributors. All rights reserved.
// Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
using Microsoft.CodeAnalysis;
using Microsoft.CodeAnalysis.Operations;
 
namespace ILLink.RoslynAnalyzer.DataFlow
{
    // Adapted from https://github.com/dotnet/roslyn/
    public abstract class OperationWalker<TArgument, TResult> : OperationVisitor<TArgument, TResult>
    {
        private int _recursionDepth;
 
        private void VisitChildOperations(IOperation operation, TArgument argument)
        {
            foreach (var child in operation.ChildOperations)
                Visit(child, argument);
        }
 
        public override TResult? Visit(IOperation? operation, TArgument argument)
        {
            if (operation != null)
            {
                _recursionDepth++;
                try
                {
                    StackGuard.EnsureSufficientExecutionStack(_recursionDepth);
                    return operation.Accept(this, argument);
                }
                finally
                {
                    _recursionDepth--;
                }
            }
            return default;
        }
 
        public override TResult? DefaultVisit(IOperation operation, TArgument argument)
        {
            VisitChildOperations(operation, argument);
            return default;
        }
    }
}