Update implementation and tests for the trap redesign

examples/consumefuel/Program.cs

@@ -45,7 +45,7 @@ static void Main(string[] args)
             {
                 expensive();
             }
-            catch (TrapException ex)
+            catch (WasmtimeException ex)
             {
                 Console.WriteLine("Exception caught with the following message:");
                 Console.WriteLine(ex.Message);

src/Export.cs

@@ -76,13 +76,13 @@ internal Export(IntPtr exportType)
             unsafe
             {
                 var name = Native.wasm_exporttype_name(exportType);
-                if (name->size == UIntPtr.Zero)
+                if (name->size == 0)
                 {
                     Name = String.Empty;
                 }
                 else
                 {
-                    Name = Marshal.PtrToStringUTF8((IntPtr)name->data, (int)name->size);
+                    Name = Marshal.PtrToStringUTF8((IntPtr)name->data, checked((int)name->size));
                 }
             }
         }

src/Function.cs

@@ -2456,14 +2456,14 @@ internal unsafe static IntPtr InvokeCallback(Delegate callback, MethodInfo callb
 
         internal static unsafe IntPtr HandleCallbackException(Exception ex)
         {
-            // Store the exception as trap cause, so that we can use it as the TrapException's
-            // InnerException when the trap bubbles up to the next host-to-wasm transition.
-            // If the exception is already a TrapException, we use that one's InnerException,
+            // Store the exception as error cause, so that we can use it as the WasmtimeException's
+            // InnerException when the error bubbles up to the next host-to-wasm transition.
+            // If the exception is already a WasmtimeException, we use that one's InnerException,
             // even if it's null.
             // Note: This code currently requires that on every host-to-wasm transition where a
-            // trap can occur, TrapException.FromOwnedTrap() is called when a trap actually occured,
-            // which will then clear this field.
-            CallbackTrapCause = ex is TrapException trapException ? trapException.InnerException : ex;
+            // error can occur, WasmtimeException.FromOwnedError() is called when an error actually
+            // occured, which will then clear this field.
+            CallbackErrorCause = ex is WasmtimeException wasmtimeException ? wasmtimeException.InnerException : ex;
 
             var bytes = Encoding.UTF8.GetBytes(ex.Message);
 
@@ -2527,17 +2527,17 @@ internal static class Native
         internal static readonly Native.Finalizer Finalizer = (p) => GCHandle.FromIntPtr(p).Free();
 
         /// <summary>
-        /// Contains the cause for a trap returned by invoking a wasm function, in case
-        /// the trap was caused by the host. 
+        /// Contains the cause for a error returned by invoking a wasm function, in case
+        /// the error was caused by the host. 
         /// </summary>
         /// <remarks>
         /// This thread-local field will be set when catching a .NET exception at the
-        /// wasm-to-host transition. When the trap bubbles up to the next host-to-wasm
+        /// wasm-to-host transition. When the error bubbles up to the next host-to-wasm
         /// transition, the field needs to be cleared, and its value can be used to set
-        /// the inner exception of the created <see cref="TrapException"/>.
+        /// the inner exception of the created <see cref="WasmtimeException"/>.
         /// </remarks>
         [ThreadStatic]
-        internal static Exception? CallbackTrapCause;
+        internal static Exception? CallbackErrorCause;
 
         private static readonly Function _null = new Function();
         private static readonly object?[] NullParams = new object?[1];

src/Import.cs

@@ -83,23 +83,23 @@ internal Import(IntPtr importType)
             unsafe
             {
                 var moduleName = Native.wasm_importtype_module(importType);
-                if (moduleName->size == UIntPtr.Zero)
+                if (moduleName->size == 0)
                 {
                     ModuleName = String.Empty;
                 }
                 else
                 {
-                    ModuleName = Marshal.PtrToStringUTF8((IntPtr)moduleName->data, (int)moduleName->size);
+                    ModuleName = Marshal.PtrToStringUTF8((IntPtr)moduleName->data, checked((int)moduleName->size));
                 }
 
                 var name = Native.wasm_importtype_name(importType);
-                if (name is null || name->size == UIntPtr.Zero)
+                if (name is null || name->size == 0)
                 {
                     Name = String.Empty;
                 }
                 else
                 {
-                    Name = Marshal.PtrToStringUTF8((IntPtr)name->data, (int)name->size);
+                    Name = Marshal.PtrToStringUTF8((IntPtr)name->data, checked((int)name->size));
                 }
             }
         }

src/Module.cs

@@ -10,7 +10,7 @@ namespace Wasmtime
     [StructLayout(LayoutKind.Sequential)]
     internal unsafe struct ByteArray : IDisposable
     {
-        public UIntPtr size;
+        public nuint size;
         public byte* data;
 
         public void Dispose()
@@ -176,7 +176,7 @@ public static Module FromText(Engine engine, string name, string text)
                 var textBytes = Encoding.UTF8.GetBytes(text);
                 fixed (byte* ptr = textBytes)
                 {
-                    var error = Native.wasmtime_wat2wasm(ptr, (UIntPtr)textBytes.Length, out var moduleBytes);
+                    var error = Native.wasmtime_wat2wasm(ptr, (nuint)textBytes.Length, out var moduleBytes);
                     if (error != IntPtr.Zero)
                     {
                         throw WasmtimeException.FromOwnedError(error);
@@ -242,7 +242,7 @@ public byte[] Serialize()
 
             using (array)
             {
-                var len = Convert.ToInt32(array.size.ToUInt32());
+                var len = checked((int)array.size);
                 var bytes = new byte[len];
                 unsafe
                 {
@@ -335,15 +335,15 @@ public static byte[] ConvertText(string wat)
                 var textBytes = Encoding.UTF8.GetBytes(wat);
                 fixed (byte* ptr = textBytes)
                 {
-                    var error = Native.wasmtime_wat2wasm(ptr, (UIntPtr)textBytes.Length, out var moduleBytes);
+                    var error = Native.wasmtime_wat2wasm(ptr, (nuint)textBytes.Length, out var moduleBytes);
                     if (error != IntPtr.Zero)
                     {
                         throw WasmtimeException.FromOwnedError(error);
                     }
 
                     using (moduleBytes)
                     {
-                        var arr = new byte[(int)moduleBytes.size];
+                        var arr = new byte[checked((int)moduleBytes.size)];
 
                         var src = new Span<byte>(moduleBytes.data, (int)moduleBytes.size);
                         src.CopyTo(arr);
@@ -424,7 +424,7 @@ internal static class Native
             public static extern void wasmtime_module_exports(IntPtr module, out ExportTypeArray exports);
 
             [DllImport(Engine.LibraryName)]
-            public static unsafe extern IntPtr wasmtime_wat2wasm(byte* text, UIntPtr len, out ByteArray bytes);
+            public static unsafe extern IntPtr wasmtime_wat2wasm(byte* text, nuint len, out ByteArray bytes);
 
             [DllImport(Engine.LibraryName)]
             public static extern unsafe IntPtr wasmtime_module_validate(Engine.Handle engine, byte* bytes, UIntPtr size);

src/TrapException.cs

@@ -37,6 +37,8 @@ public enum TrapCode
         Unreachable = 9,
         /// <summary>The trap was the result of interrupting execution.</summary>
         Interrupt = 10,
+        /// <summary>The trap was the result of running out of the configured fuel amount.</summary>
+        OutOfFuel = 11,
     }
 
     /// <summary>
@@ -53,13 +55,13 @@ unsafe internal TrapFrame(IntPtr frame)
             ModuleName = null;
 
             var bytes = Native.wasmtime_frame_func_name(frame);
-            if (bytes != null && (int)bytes->size > 0)
+            if (bytes != null && checked((int)bytes->size) > 0)
             {
                 FunctionName = Encoding.UTF8.GetString(bytes->data, (int)bytes->size);
             }
 
             bytes = Native.wasmtime_frame_module_name(frame);
-            if (bytes != null && (int)bytes->size > 0)
+            if (bytes != null && checked((int)bytes->size) > 0)
             {
                 ModuleName = Encoding.UTF8.GetString(bytes->data, (int)bytes->size);
             }
@@ -88,10 +90,10 @@ unsafe internal TrapFrame(IntPtr frame)
         private static class Native
         {
             [DllImport(Engine.LibraryName)]
-            public static extern UIntPtr wasm_frame_func_offset(IntPtr frame);
+            public static extern nuint wasm_frame_func_offset(IntPtr frame);
 
             [DllImport(Engine.LibraryName)]
-            public static extern UIntPtr wasm_frame_module_offset(IntPtr frame);
+            public static extern nuint wasm_frame_module_offset(IntPtr frame);
 
             [DllImport(Engine.LibraryName)]
             public static extern unsafe ByteArray* wasmtime_frame_func_name(IntPtr frame);
@@ -127,28 +129,12 @@ public TrapCode TrapCode
             {
                 if (TrapException.Native.wasmtime_trap_code(_trap, out var code))
                 {
-                    return code;
+                    return (TrapCode)code;
                 }
                 return TrapCode.Undefined;
             }
         }
 
-        /// <summary>
-        /// Attempt to get a WASI exit status code from this trap. May be null if no status code is available.
-        /// </summary>
-        public int? ExitStatus
-        {
-            get
-            {
-                if (TrapException.Native.wasmtime_trap_exit_status(_trap, out var exitStatus))
-                {
-                    return exitStatus;
-                }
-
-                return null;
-            }
-        }
-
         /// <summary>
         /// Get the message string
         /// </summary>
@@ -223,16 +209,7 @@ public List<TrapFrame> GetFrames()
             TrapException.Native.wasm_trap_trace(_trap, out var frames);
             using (frames)
             {
-                var trapFrames = new List<TrapFrame>((int)frames.size);
-                for (var i = 0; i < (int)frames.size; ++i)
-                {
-                    unsafe
-                    {
-                        trapFrames.Add(new TrapFrame(frames.data[i]));
-                    }
-                }
-
-                return trapFrames;
+                return TrapException.GetFrames(frames);
             }
         }
 
@@ -261,18 +238,6 @@ public TrapException(string message) : base(message) { }
         /// <inheritdoc/>
         public TrapException(string message, Exception? inner) : base(message, inner) { }
 
-        /// <summary>
-        /// Gets the trap's frames.
-        /// </summary>
-        public IReadOnlyList<TrapFrame>? Frames { get; protected set; }
-
-        /// <summary>
-        /// The exit code when the trap results from executing the WASI `proc_exit` function.
-        ///
-        /// The value is null if the trap was not an exit trap.
-        /// </summary>
-        public int? ExitCode { get; private set; }
-
         /// <summary>
         /// Indentifies which type of trap this is.
         /// </summary>
@@ -290,24 +255,10 @@ internal TrapException(string message, IReadOnlyList<TrapFrame>? frames, TrapCod
 
         internal static TrapException FromOwnedTrap(IntPtr trap, bool delete = true)
         {
-            // Get the cause of the trap if available (in case the trap was caused by a
-            // .NET exception thrown in a callback).
-            var callbackTrapCause = Function.CallbackTrapCause;
-
-            if (callbackTrapCause is not null)
-            {
-                // Clear the field as we consumed the value.
-                Function.CallbackTrapCause = null;
-            }
-
             var accessor = new TrapAccessor(trap);
             try
             {
-                var trappedException = new TrapException(accessor.Message, accessor.GetFrames(), accessor.TrapCode, callbackTrapCause)
-                {
-                    ExitCode = accessor.ExitStatus
-                };
-
+                var trappedException = new TrapException(accessor.Message, accessor.GetFrames(), accessor.TrapCode);
                 return trappedException;
             }
             finally
@@ -317,12 +268,27 @@ internal static TrapException FromOwnedTrap(IntPtr trap, bool delete = true)
             }
         }
 
-        internal static class Native
+        internal static List<TrapFrame> GetFrames(Native.FrameArray frames)
+        {
+            int framesSize = checked((int)frames.size);
+            var trapFrames = new List<TrapFrame>(framesSize);
+            for (var i = 0; i < framesSize; ++i)
+            {
+                unsafe
+                {
+                    trapFrames.Add(new TrapFrame(frames.data[i]));
+                }
+            }
+
+            return trapFrames;
+        }
+
+        internal new static class Native
         {
             [StructLayout(LayoutKind.Sequential)]
             public unsafe struct FrameArray : IDisposable
             {
-                public UIntPtr size;
+                public nuint size;
                 public IntPtr* data;
 
                 public void Dispose()
@@ -335,7 +301,7 @@ public void Dispose()
             public static extern void wasm_trap_message(IntPtr trap, out ByteArray message);
 
             [DllImport(Engine.LibraryName)]
-            public static extern void wasm_trap_trace(IntPtr trap, out FrameArray message);
+            public static extern void wasm_trap_trace(IntPtr trap, out FrameArray frames);
 
             [DllImport(Engine.LibraryName)]
             public static extern void wasm_trap_delete(IntPtr trap);
@@ -345,11 +311,7 @@ public void Dispose()
 
             [DllImport(Engine.LibraryName)]
             [return: MarshalAs(UnmanagedType.I1)]
-            internal static extern bool wasmtime_trap_exit_status(IntPtr trap, out int exitStatus);
-
-            [DllImport(Engine.LibraryName)]
-            [return: MarshalAs(UnmanagedType.I1)]
-            internal static extern bool wasmtime_trap_code(IntPtr trap, out TrapCode exitCode);
+            internal static extern bool wasmtime_trap_code(IntPtr trap, out byte exitCode);
         }
     }
 }