Hastlayer-SDK

using Hast.Transformer.Helpers;
using ICSharpCode.Decompiler.CSharp.Syntax;
using System;
using System.Linq;

namespace Hast.Transformer.Services;

public class SimpleMemoryUsageVerifier : ISimpleMemoryUsageVerifier
{
    public void VerifySimpleMemoryUsage(SyntaxTree syntaxTree)
    {
        foreach (var type in syntaxTree.GetAllTypeDeclarations())
        {
            foreach (var member in type.Members.Where(member => member.IsHardwareEntryPointMember()))
            {
                if (member is not MethodDeclaration method) continue;

                var methodName = member.GetFullName();

                if (string.IsNullOrEmpty(method.GetSimpleMemoryParameterName()))
                {
                    throw new InvalidOperationException(
                        "The method " + methodName + " doesn't have a necessary SimpleMemory parameter. Hardware entry points should have one.");
                }

                if (method.Parameters.Count > 1)
                {
                    throw new InvalidOperationException(
                        $"The method {methodName} contains parameters apart from the SimpleMemory parameter." +
                        $" Hardware entry points should only have a single SimpleMemory parameter and " +
                        $"nothing else.");
                }
            }
        }

        syntaxTree.AcceptVisitor(new SimpleMemoryAssignmentVerifyingVisitor());
    }

    private sealed class SimpleMemoryAssignmentVerifyingVisitor : DepthFirstAstVisitor
    {
        public override void VisitAssignmentExpression(AssignmentExpression assignmentExpression)
        {
            base.VisitAssignmentExpression(assignmentExpression);

            if (SimpleMemoryAssignmentHelper.IsBatchedReadAssignment(assignmentExpression, out var cellCount) &&
                cellCount <= 0)
            {
                throw new NotSupportedException(
                    "The cell count parameter of the batched SimpleMemory read operation in the expression " +
                    assignmentExpression +
                    " couldn't be statically determined. Such operations need to define the cell count at compile-time."
                    .AddParentEntityName(assignmentExpression));
            }
        }
    }
}