[Proposal]: Caller info attribute for passing caller identity implicitly

[jaredpar]

Caller info attribute for passing caller identity implicitly

• Specification:
• Discussion: [API proposal] Attribute for passing caller identity implicitly #9017

Summary

namespace System.Runtime.CompilerServices
{
    [AttributeUsage(AttributeTargets.Parameter, AllowMultiple = false, Inherited = false)]
    public sealed class CallerIdentityAttribute : Attribute
    {
        public CallerIdentityAttribute();
    }
}

This attribute can be applied to parameters of type System.Reflection.Assembly, System.Reflection.Type, System.Reflection.MethodBase. When the C# compiler sees parameter tagged with this attribute, it will provide default value for it, according to the caller context:

• System.Reflection.Assembly: typeof(containing_type).Assembly
• System.Reflection.Type: typeof(containing_type)
• System.Reflection.MethodBase: MethodBase.GetMethodFromHandle(ldtoken containing_method)

Design meetings

• https://github.com/dotnet/csharplang/blob/main/meetings/2021/LDM-2021-09-22.md#calleridentityattribute
• https://github.com/dotnet/csharplang/blob/main/meetings/2022/LDM-2022-01-24.md#attribute-for-passing-caller-identity-implicitly