Replace UnixLoader with NativeLibraryEx (#13217)

src/Avalonia.Native/AvaloniaNativePlatform.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Runtime.InteropServices;
+using Avalonia.Compatibility;
 using Avalonia.Controls.Platform;
 using Avalonia.Input;
 using Avalonia.Input.Platform;
@@ -39,15 +40,14 @@ namespace Avalonia.Native
         {
             if (options.AvaloniaNativeLibraryPath != null)
             {
-                var loader = RuntimeInformation.IsOSPlatform(OSPlatform.Windows) ?
-                    (IDynLoader)new Win32Loader() :
-                    new UnixLoader();
-
-                var lib = loader.LoadLibrary(options.AvaloniaNativeLibraryPath);
-                var proc = loader.GetProcAddress(lib, "CreateAvaloniaNative", false);
+                var lib = NativeLibraryEx.Load(options.AvaloniaNativeLibraryPath);
+                if (!NativeLibraryEx.TryGetExport(lib, "CreateAvaloniaNative", out var proc))
+                {
+                    throw new InvalidOperationException(
+                        "Unable to get \"CreateAvaloniaNative\" export from AvaloniaNativeLibrary library");
+                }
                 var d = Marshal.GetDelegateForFunctionPointer<CreateAvaloniaNativeDelegate>(proc);
 
-
                 return Initialize(d(), options);
             }
             else

src/Avalonia.Native/DynLoader.cs

@@ -1,125 +0,0 @@
-using System;
-using System.Runtime.InteropServices;
-
-/*
- * Source code imported from https://github.com/kekekeks/evhttp-sharp
- * Source is provided under MIT license for Avalonia project and derived works
- */
-
-namespace Avalonia.Native
-{
-    internal interface IDynLoader
-    {
-        IntPtr LoadLibrary(string dll);
-        IntPtr GetProcAddress(IntPtr dll, string proc, bool optional);
-
-    }
-
-    class UnixLoader : IDynLoader
-    {
-        // ReSharper disable InconsistentNaming
-        static class LinuxImports
-        {
-            [DllImport("libdl.so.2")]
-            private static extern IntPtr dlopen(string path, int flags);
-
-            [DllImport("libdl.so.2")]
-            private static extern IntPtr dlsym(IntPtr handle, string symbol);
-
-            [DllImport("libdl.so.2")]
-            private static extern IntPtr dlerror();
-
-            public static void Init()
-            {
-                DlOpen = dlopen;
-                DlSym = dlsym;
-                DlError = dlerror;
-            }
-        }
-
-        static class OsXImports
-        {
-            [DllImport("/usr/lib/libSystem.dylib")]
-            private static extern IntPtr dlopen(string path, int flags);
-
-            [DllImport("/usr/lib/libSystem.dylib")]
-            private static extern IntPtr dlsym(IntPtr handle, string symbol);
-
-            [DllImport("/usr/lib/libSystem.dylib")]
-            private static extern IntPtr dlerror();
-
-            public static void Init()
-            {
-                DlOpen = dlopen;
-                DlSym = dlsym;
-                DlError = dlerror;
-            }
-
-        }
-
-        [DllImport("libc")]
-        static extern int uname(IntPtr buf);
-
-        static UnixLoader()
-        {
-            var buffer = Marshal.AllocHGlobal(0x1000);
-            uname(buffer);
-            var unixName = Marshal.PtrToStringAnsi(buffer);
-            Marshal.FreeHGlobal(buffer);
-            if (unixName == "Darwin")
-                OsXImports.Init();
-            else
-                LinuxImports.Init();
-        }
-
-        private static Func<string, int, IntPtr> DlOpen;
-        private static Func<IntPtr, string, IntPtr> DlSym;
-        private static Func<IntPtr> DlError;
-        // ReSharper restore InconsistentNaming
-
-        static string DlErrorString() => Marshal.PtrToStringAnsi(DlError());
-
-        public IntPtr LoadLibrary(string dll)
-        {
-            var handle = DlOpen(dll, 1);
-            if (handle == IntPtr.Zero)
-                throw new Exception(DlErrorString());
-            return handle;
-        }
-
-        public IntPtr GetProcAddress(IntPtr dll, string proc, bool optional)
-        {
-            var ptr = DlSym(dll, proc);
-            if (ptr == IntPtr.Zero && !optional)
-                throw new Exception(DlErrorString());
-            return ptr;
-        }
-    }
-
-    internal class Win32Loader : IDynLoader
-    {
-        [DllImport("kernel32", CharSet = CharSet.Ansi, ExactSpelling = true, SetLastError = true)]
-        private static extern IntPtr GetProcAddress(IntPtr hModule, string procName);
-
-        [DllImport("kernel32", EntryPoint = "LoadLibraryW", SetLastError = true, CharSet = CharSet.Unicode)]
-        private static extern IntPtr LoadLibrary(string lpszLib);
-
-        IntPtr IDynLoader.LoadLibrary(string dll)
-        {
-            var handle = LoadLibrary(dll);
-            if (handle != IntPtr.Zero)
-                return handle;
-            var err = Marshal.GetLastWin32Error();
-
-            throw new Exception("Error loading " + dll + " error " + err);
-        }
-
-        IntPtr IDynLoader.GetProcAddress(IntPtr dll, string proc, bool optional)
-        {
-            var ptr = GetProcAddress(dll, proc);
-            if (ptr == IntPtr.Zero && !optional)
-                throw new Exception("Error " + Marshal.GetLastWin32Error());
-            return ptr;
-        }
-    }
-}