AssemblyGen.cs

Go to the documentation of this file.

using System.Diagnostics.CodeAnalysis;
using System.Dynamic.Utils;
using System.Reflection;
using System.Reflection.Emit;
using System.Text;
using System.Threading;
 
namespace System.Linq.Expressions.Compiler;
 
internal sealed class AssemblyGen
{
    private static AssemblyGen s_assembly;
 
    private readonly ModuleBuilder _myModule;
 
    private int _index;
 
    private static AssemblyGen Assembly
    {
        get
        {
            if (s_assembly == null)
            {
                Interlocked.CompareExchange(ref s_assembly, new AssemblyGen(), null);
            }
            return s_assembly;
        }
    }
 
    private AssemblyGen()
    {
        AssemblyName assemblyName = new AssemblyName("Snippets");
        AssemblyBuilder assemblyBuilder = AssemblyBuilder.DefineDynamicAssembly(assemblyName, AssemblyBuilderAccess.Run);
        _myModule = assemblyBuilder.DefineDynamicModule(assemblyName.Name);
    }
 
    private TypeBuilder DefineType(string name, [DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.All)] Type parent, TypeAttributes attr)
    {
        ContractUtils.RequiresNotNull(name, "name");
        ContractUtils.RequiresNotNull(parent, "parent");
        StringBuilder stringBuilder = new StringBuilder(name);
        int value = Interlocked.Increment(ref _index);
        stringBuilder.Append('$');
        stringBuilder.Append(value);
        stringBuilder.Replace('+', '_').Replace('[', '_').Replace(']', '_')
            .Replace('*', '_')
            .Replace('&', '_')
            .Replace(',', '_')
            .Replace('\\', '_');
        name = stringBuilder.ToString();
        return _myModule.DefineType(name, attr, parent);
    }
 
    [UnconditionalSuppressMessage("ReflectionAnalysis", "IL2026:RequiresUnreferencedCode", Justification = "MulticastDelegate has a ctor with RequiresUnreferencedCode, but the generated derived type doesn't reference this ctor, so this is trim compatible.")]
    [UnconditionalSuppressMessage("ReflectionAnalysis", "IL2111:ReflectionToDynamicallyAccessedMembers", Justification = "MulticastDelegate and Delegate have multiple methods with DynamicallyAccessedMembers annotations. But the generated codein this case will not call any of them (it only defines a .ctor and Invoke method both of which are runtime implemented.")]
    internal static TypeBuilder DefineDelegateType(string name)
    {
        return Assembly.DefineType(name, typeof(MulticastDelegate), TypeAttributes.Public | TypeAttributes.Sealed | TypeAttributes.AutoClass);
    }
}