public unsafe DacLibrary()

in src/Microsoft.Diagnostics.Runtime/DacLibrary.cs [23:101]
66 lines of code
12 McCabe index (conditional complexity)

        public unsafe DacLibrary(DataTarget dataTarget, string dacPath, ulong runtimeBaseAddress)
        {
            if (dataTarget is null)
                throw new ArgumentNullException(nameof(dataTarget));

            if (dataTarget.ClrVersions.Length == 0)
                throw new ClrDiagnosticsException("Process is not a CLR process!");

            IDisposable? fileLock = null;
            IntPtr dacLibrary;
            try
            {
                if (dataTarget.CustomDataTarget.DacSignatureVerificationEnabled)
                {
                    if (!AuthenticodeUtil.VerifyDacDll(dacPath, out fileLock))
                    {
                        throw new ClrDiagnosticsException($"Failed to load dac from {dacPath}: not properly signed");
                    }
                }

                try
                {
                    dacLibrary = DataTarget.PlatformFunctions.LoadLibrary(dacPath);
                }
                catch (Exception e) when (e is DllNotFoundException or BadImageFormatException)
                {
                    throw new ClrDiagnosticsException($"Failed to load dac from {dacPath}: {e.Message}", e);
                }
            }
            finally
            {
                fileLock?.Dispose();
            }

            OwningLibrary = new RefCountedFreeLibrary(dacLibrary);

            IntPtr initAddr = DataTarget.PlatformFunctions.GetLibraryExport(dacLibrary, "DAC_PAL_InitializeDLL");
            if (initAddr == IntPtr.Zero)
                initAddr = DataTarget.PlatformFunctions.GetLibraryExport(dacLibrary, "PAL_InitializeDLL");

            if (initAddr != IntPtr.Zero)
            {
                IntPtr dllMain = DataTarget.PlatformFunctions.GetLibraryExport(dacLibrary, "DllMain");
                if (dllMain == IntPtr.Zero)
                    throw new ClrDiagnosticsException("Failed to obtain dac DllMain");

                delegate* unmanaged[Stdcall]<IntPtr, int, IntPtr, int> main = (delegate* unmanaged[Stdcall]<IntPtr, int, IntPtr, int>)dllMain;
                main(dacLibrary, 1, IntPtr.Zero);
            }

            IntPtr addr = DataTarget.PlatformFunctions.GetLibraryExport(dacLibrary, "CLRDataCreateInstance");
            if (addr == IntPtr.Zero)
                throw new ClrDiagnosticsException("Failed to obtain Dac CLRDataCreateInstance");

            DacDataTarget = new DacDataTarget(dataTarget, runtimeBaseAddress);

            delegate* unmanaged[Stdcall]<in Guid, IntPtr, out IntPtr, int> func = (delegate* unmanaged[Stdcall]<in Guid, IntPtr, out IntPtr, int>)addr;
            Guid guid = new("5c552ab6-fc09-4cb3-8e36-22fa03c798b7");

#if NET6_0_OR_GREATER
            IntPtr iDacDataTarget = DacDataTargetCOM.CreateIDacDataTarget(DacDataTarget);
            int res = func(guid, iDacDataTarget, out nint iUnk);
            Marshal.Release(iDacDataTarget);
#else
            LegacyDacDataTargetWrapper wrapper = new(DacDataTarget, DacDataTarget.RuntimeBaseAddress != 0);
            int res = func(guid, wrapper.IDacDataTarget, out nint iUnk);
            GC.KeepAlive(wrapper);
#endif

            unchecked
            {
                if ((uint)res == 0x80131c4f)
                    throw new ClrDiagnosticsException($"Failure loading DAC: CreateDacInstance failed 0x{res:x}, which usually indicates the dump file was taken incorrectly.", res);
                else if (res != 0)
                    throw new ClrDiagnosticsException($"Failure loading DAC: CreateDacInstance failed 0x{res:x}", res);
            }

            _clrDataProcess = new ClrDataProcess(this, iUnk);
        }