Merge pull request bytecodealliance#718 from AustinWise/austin/OtherF…

…ixes

[dotnet] Some small fixes and unit tests

crates/misc/dotnet/.gitignore

@@ -2,6 +2,7 @@
 *.*~
 .DS_Store
 
+.vs/
 .vscode
 
 bin/

crates/misc/dotnet/Wasmtime.sln

@@ -0,0 +1,31 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio Version 16
+VisualStudioVersion = 16.0.29519.181
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Wasmtime", "src\Wasmtime.csproj", "{5EB63C51-5286-4DDF-BF7F-4110CC6D80B8}"
+EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Wasmtime.Tests", "tests\Wasmtime.Tests.csproj", "{8A200114-1D0B-4F90-9F82-1FFE47C207DD}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{5EB63C51-5286-4DDF-BF7F-4110CC6D80B8}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{5EB63C51-5286-4DDF-BF7F-4110CC6D80B8}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{5EB63C51-5286-4DDF-BF7F-4110CC6D80B8}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{5EB63C51-5286-4DDF-BF7F-4110CC6D80B8}.Release|Any CPU.Build.0 = Release|Any CPU
+		{8A200114-1D0B-4F90-9F82-1FFE47C207DD}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{8A200114-1D0B-4F90-9F82-1FFE47C207DD}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{8A200114-1D0B-4F90-9F82-1FFE47C207DD}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{8A200114-1D0B-4F90-9F82-1FFE47C207DD}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {F5AC35E5-1373-49E6-97DC-68CB5E0369E0}
+	EndGlobalSection
+EndGlobal

crates/misc/dotnet/src/Bindings/FunctionBinding.cs

@@ -240,17 +240,17 @@ private unsafe Interop.WasmFuncCallback CreateCallback(Store store, IHost host)
                 {
                     SetArgs(arguments, args);
 
-                    var result = Method.Invoke(host, args);
+                    var result = Method.Invoke(host, BindingFlags.DoNotWrapExceptions, null, args, null);
 
                     if (hasReturn)
                     {
                         SetResults(result, results);
                     }
                     return IntPtr.Zero;
                 }
-                catch (TargetInvocationException ex)
+                catch (Exception ex)
                 {
-                    var bytes = Encoding.UTF8.GetBytes(ex.InnerException.Message + "\0" /* exception messages need a null */);
+                    var bytes = Encoding.UTF8.GetBytes(ex.Message + "\0" /* exception messages need a null */);
 
                     fixed (byte* ptr = bytes)
                     {

crates/misc/dotnet/src/Bindings/MemoryBinding.cs

@@ -45,7 +45,7 @@ public MemoryBinding(MemoryImport import, FieldInfo field)
 
         internal override SafeHandle Bind(Store store, IHost host)
         {
-            dynamic memory = Field.GetValue(host);
+            Memory memory = (Memory)Field.GetValue(host);
             if (memory.Handle != null)
             {
                 throw new InvalidOperationException("Cannot bind more than once.");

crates/misc/dotnet/src/TrapException.cs

@@ -1,6 +1,6 @@
 using System;
-using System.Runtime.InteropServices;
 using System.Runtime.Serialization;
+using System.Text;
 
 namespace Wasmtime
 {
@@ -27,7 +27,13 @@ internal static TrapException FromOwnedTrap(IntPtr trap)
             unsafe
             {
                 Interop.wasm_trap_message(trap, out var bytes);
-                var message = Marshal.PtrToStringUTF8((IntPtr)bytes.data, (int)bytes.size - 1 /* remove null */);
+                var byteSpan = new ReadOnlySpan<byte>(bytes.data, checked((int)bytes.size));
+
+                int indexOfNull = byteSpan.IndexOf((byte)0);
+                if (indexOfNull != -1)
+                    byteSpan = byteSpan.Slice(0, indexOfNull);
+
+                var message = Encoding.UTF8.GetString(byteSpan);
                 Interop.wasm_byte_vec_delete(ref bytes);
 
                 Interop.wasm_trap_delete(trap);

crates/misc/dotnet/tests/FunctionThunkingTests.cs

@@ -0,0 +1,71 @@
+using FluentAssertions;
+using System;
+using System.Linq;
+using Xunit;
+
+namespace Wasmtime.Tests
+{
+    public class FunctionThunkingFixture : ModuleFixture
+    {
+        protected override string ModuleFileName => "FunctionThunking.wasm";
+    }
+
+    public class FunctionThunkingTests : IClassFixture<FunctionThunkingFixture>
+    {
+        const string THROW_MESSAGE = "Test error messages for wasmtime dotnet bidnings unit tests.";
+
+        class MyHost : IHost
+        {
+            public Instance Instance { get; set; }
+
+            [Import("add", Module = "env")]
+            public int Add(int x, int y) => x + y;
+
+            [Import("do_throw", Module = "env")]
+            public void Throw() => throw new Exception(THROW_MESSAGE);
+        }
+
+        public FunctionThunkingTests(FunctionThunkingFixture fixture)
+        {
+            Fixture = fixture;
+        }
+
+        private FunctionThunkingFixture Fixture { get; }
+
+        [Fact]
+        public void ItBindsImportMethodsAndCallsThemCorrectly()
+        {
+            var host = new MyHost();
+            using (var instance = Fixture.Module.Instantiate(host))
+            {
+                var add_func = instance.Externs.Functions.Where(f => f.Name == "add_wrapper").Single();
+                int invoke_add(int x, int y) => (int)add_func.Invoke(new object[] { x, y });
+
+                invoke_add(40, 2).Should().Be(42);
+                invoke_add(22, 5).Should().Be(27);
+
+                //Collect garbage to make sure delegate function pointers pasted to wasmtime are rooted.
+                GC.Collect();
+                GC.WaitForPendingFinalizers();
+
+                invoke_add(1970, 50).Should().Be(2020);
+            }
+        }
+
+        [Fact]
+        public void ItPropegatesExceptionsToCallersViaTraps()
+        {
+            var host = new MyHost();
+            using (var instance = Fixture.Module.Instantiate(host))
+            {
+                var throw_func = instance.Externs.Functions.Where(f => f.Name == "do_throw_wrapper").Single();
+                Action action = () => throw_func.Invoke();
+
+                action
+                    .Should()
+                    .Throw<TrapException>()
+                    .WithMessage(THROW_MESSAGE);
+            }
+        }
+    }
+}

crates/misc/dotnet/tests/Modules/FunctionThunking.wat

@@ -0,0 +1,20 @@
+(module
+ (type $FUNCSIG$iii (func (param i32 i32) (result i32)))
+ (type $FUNCSIG$v (func))
+ (import "env" "add" (func $add (param i32 i32) (result i32)))
+ (import "env" "do_throw" (func $do_throw))
+ (table 0 anyfunc)
+ (memory $0 1)
+ (export "memory" (memory $0))
+ (export "add_wrapper" (func $add_wrapper))
+ (export "do_throw_wrapper" (func $do_throw_wrapper))
+ (func $add_wrapper (; 2 ;) (param $0 i32) (param $1 i32) (result i32)
+  (call $add
+   (get_local $0)
+   (get_local $1)
+  )
+ )
+ (func $do_throw_wrapper (; 3 ;)
+  (call $do_throw)
+ )
+)