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haha funny jit go brrrr
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using System; | |
using System.Runtime.CompilerServices; | |
using System.Reflection; | |
using System.Reflection.Emit; | |
namespace FunkyJit | |
{ | |
class Program | |
{ | |
public static void Nothing() { Console.WriteLine(); } | |
static void Main(string[] args) | |
{ | |
IntPtr pMem = GenerateRWXMemory(4096); // Doesn't divide cleanly so we get 4113 (17 extra bytes) of space | |
Console.WriteLine("Method Table: 0x{0:X}", (long)typeof(Program).TypeHandle.Value); | |
Console.WriteLine("JIT: 0x{0:X} ?", (long)pMem); | |
Console.ReadKey(); | |
} | |
public static IntPtr GenerateRWXMemory(int ByteCount) | |
{ | |
AssemblyName AssemblyName = new AssemblyName("Assembly"); | |
AssemblyBuilder AssemblyBuilder = AppDomain.CurrentDomain.DefineDynamicAssembly(AssemblyName, AssemblyBuilderAccess.Run); | |
ModuleBuilder ModuleBuilder = AssemblyBuilder.DefineDynamicModule("Module"); | |
MethodBuilder MethodBuilder = ModuleBuilder.DefineGlobalMethod( | |
"MethodName", | |
MethodAttributes.Public | MethodAttributes.Static, | |
typeof(void), //arbitrary return type hehexd | |
new Type[] { }); // no args, but no real reason | |
ILGenerator il = MethodBuilder.GetILGenerator(); | |
// sub rsp,28h (0x48, 0x83, 0xec, 0x28) [4] | |
// Every Emit.WriteLine results in 18 bytes | |
// mov rcx,1D3E2F736A8h (0xe8, 0x7a, 0x07, 0x45, 0x5e) [5] | |
// rcx,qword ptr [rcx] (0x48, 0x8b, 0x09) [3] | |
// call mscorlib_ni!System.Console.WriteLine (0x48, 0xb9, 0xa8, 0x36, 0xf7, 0xe2, 0x2d, 0x30, 0x10, 0x00) [10] | |
// Ends with | |
// ret (0xc3) [1] | |
while (ByteCount > 0) | |
{ | |
il.EmitWriteLine("bruh"); | |
ByteCount -= 18; | |
} | |
il.Emit(OpCodes.Ret); // JIT to 0xc3 | |
ModuleBuilder.CreateGlobalFunctions(); | |
RuntimeMethodHandle mh = ModuleBuilder.GetMethods()[0].MethodHandle; | |
RuntimeHelpers.PrepareMethod(mh); | |
return mh.GetFunctionPointer(); | |
} | |
} | |
} |
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