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Shows how to use the prototype inline IL ASM with Roslyn
using System;
using System.IO;
using System.Runtime.CompilerServices;
namespace System.Runtime.CompilerServices
{
[AttributeUsage(AttributeTargets.Method)]
internal class CompilerIntrinsicAttribute : Attribute { }
}
class Program
{
[CompilerIntrinsic]
static void il(params object[] args) {} // cannot use extern for the prototype, as it fails when loading the type without a DllImport
[CompilerIntrinsic]
static T il<T>(params object[] args) { return default(T); } // cannot use extern for the prototype, as it fails when loading the type without a DllImport
struct Vector3
{
public float X;
public float Y;
public float Z;
}
public static int SizeOf<T>() where T : struct
{
// sizeof with generic!
return il<int>(@sizeof, T);
}
public static void TryBindMethod(string[] args)
{
Console.WriteLine($"method call: TryBindMethod with {args.Length} arguments");
}
public static void Main(string[] args)
{
// -----------------------
// method call
// -----------------------
// Console.WriteLine(sizeof(Vector3) + 4)
// IL_0000: nop
// IL_0001: sizeof Program/Vector3
// IL_0007: ldc.i4.4
// IL_0008: add
// IL_0009: call void [mscorlib]System.Console::WriteLine(int32)
il(nop); // just to show that we can output nop, not really instesting though!
il(@sizeof, Vector3); // use of @ as sizeof is a keyword
il(ldc.i4_4);
il(add);
il(call, Console.WriteLine(default(int))); // we define the signature with a fake method call
// -----------------------
// load from local var
// -----------------------
var myLocalArgs = args;
il(ldloc, myLocalArgs);
il(call, TryBindMethod);
// -----------------------
// store to local var
// -----------------------
int x;
il(@sizeof, Vector3); // use of @ as sizeof is a keyword
il(stloc, x);
Console.WriteLine("sizeof<Vector3> stored in local var: " + x);
// -----------------------
// sizeof with generic
// -----------------------
Console.WriteLine("Sizeof<T> with Vector3: " + SizeOf<Vector3>());
}
}
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