Program.cs

using System;
using System.Runtime.InteropServices;
using LLVMSharp;

namespace feel_llvm
{
    internal sealed class Program
    {
        [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
        public delegate int Add(int a, int b);

        static void Main(string[] args)
        {
            Console.WriteLine("Hello World!");

            LLVMBool Success = new LLVMBool(0);
            LLVMModuleRef mod = LLVM.ModuleCreateWithName("LLVMSharpIntro");

            LLVMTypeRef[] param_types = { LLVM.Int32Type(), LLVM.Int32Type() };
            LLVMTypeRef ret_type = LLVM.FunctionType(LLVM.Int32Type(), param_types, false);
            LLVMValueRef sum = LLVM.AddFunction(mod, "sum", ret_type);

            LLVMBasicBlockRef entry = LLVM.AppendBasicBlock(sum, "entry");

            LLVMBuilderRef builder = LLVM.CreateBuilder();
            LLVM.PositionBuilderAtEnd(builder, entry);
            LLVMValueRef tmp = LLVM.BuildAdd(builder, LLVM.GetParam(sum, 0), LLVM.GetParam(sum, 1), "tmp");
            LLVM.BuildRet(builder, tmp);

            if (LLVM.VerifyModule(mod, LLVMVerifierFailureAction.LLVMPrintMessageAction, out var error) != Success)
            {
                Console.WriteLine($"Error: {error}");
            }

            LLVM.LinkInMCJIT();

            LLVM.InitializeX86TargetMC();
            LLVM.InitializeX86Target();
            LLVM.InitializeX86TargetInfo();
            LLVM.InitializeX86AsmParser();
            LLVM.InitializeX86AsmPrinter();

            LLVMMCJITCompilerOptions options = new LLVMMCJITCompilerOptions { NoFramePointerElim = 1 };
            LLVM.InitializeMCJITCompilerOptions(options);
            if (LLVM.CreateMCJITCompilerForModule(out var engine, mod, options, out error) != Success)
            {
                Console.WriteLine($"Error: {error}");
            }

            var addMethod = (Add)Marshal.GetDelegateForFunctionPointer(LLVM.GetPointerToGlobal(engine, sum), typeof(Add));
            int result = addMethod(10, 10);

            Console.WriteLine("Result of sum is: " + result);

            if (LLVM.WriteBitcodeToFile(mod, "sum.bc") != 0)
            {
                Console.WriteLine("error writing bitcode to file, skipping");
            }

            LLVM.DumpModule(mod);

            LLVM.DisposeBuilder(builder);
            LLVM.DisposeExecutionEngine(engine);
        }
    }
}