Emscripten interop sample

src/Web/Avalonia.Web.Sample/Program.cs

@@ -6,6 +6,8 @@ internal partial class Program
 {
     private static void Main(string[] args)
     {
+        Emscripten.Log(EM_LOG.ERROR, "MyError");
+
         BuildAvaloniaApp().SetupBrowserApp("out");
     }
 

src/Web/Avalonia.Web/Avalonia.Web.targets

@@ -1,5 +1,6 @@
 <Project>
   <ItemGroup>
+    <NativeFileReference Include="$(MSBuildThisFileDirectory)/Interop/libEmscripten.c" />  
     <WasmExtraFilesToDeploy Include="$(MSBuildThisFileDirectory)/wwwroot/**/*.*" />
     <NativeFileReference Include="$(HarfBuzzSharpStaticLibraryPath)\3.1.7\libHarfBuzzSharp.a" />
     <NativeFileReference Include="$(SkiaSharpStaticLibraryPath)\3.1.7\libSkiaSharp.a" />

src/Web/Avalonia.Web/Interop/Emscripten.cs

@@ -0,0 +1,31 @@
+using System;
+using System.Runtime.InteropServices;
+
+namespace Avalonia.Web
+{
+    public static partial class Emscripten
+    {
+        const string Prefix = "av_";
+        const string Library = "libEmscripten";
+
+        [LibraryImport(Library, EntryPoint = Prefix + "log", StringMarshalling = StringMarshalling.Utf8)]
+        public static partial void Log(EM_LOG flags, string format);
+
+        [LibraryImport(Library, EntryPoint = Prefix + "debugger")]
+        public static partial void Debugger();
+    }
+
+    [Flags]
+    public enum EM_LOG : int
+    {
+        CONSOLE = 1,
+        WARN = 2,
+        ERROR = 4,
+        C_STACK = 8,
+        JS_STACK = 16,
+        NO_PATHS = 64,
+        FUNC_PARAMS = 128,
+        DEBUG = 256,
+        INFO = 512,
+    }
+}

src/Web/Avalonia.Web/Interop/libEmscripten.c

@@ -0,0 +1,9 @@
+#include <emscripten.h>
+
+void av_log(int flags, const char* format) {
+    emscripten_log(flags, format);
+}
+
+void av_debugger() {
+    emscripten_debugger();
+}