Implement module linking.

.github/workflows/main.yml

@@ -53,19 +53,10 @@ jobs:
       if: matrix.config == 'release'
       run: dotnet run -c ${{ matrix.config }} --project benchmarks/simple/simple.csproj
     - name: Run examples
+      env:
+        EXAMPLES: externref funcref global hello linking memory table
       run: |
-        cd examples/hello
-        dotnet run
-        cd ../global
-        dotnet run
-        cd ../memory
-        dotnet run
-        cd ../table
-        dotnet run
-        cd ../externref
-        dotnet run
-        cd ../funcref
-        dotnet run
+        for e in $EXAMPLES; do cd examples/$e && dotnet run && cd ../..; done
     - name: Create package
       run: |
         cd src

Directory.Build.props

@@ -1,7 +1,7 @@
 <Project>
   <PropertyGroup>
     <DevBuild Condition="'$(DevBuild)'==''">true</DevBuild>
-    <WasmtimeVersion Condition="'$(WasmtimeVersion)'==''">0.21.0</WasmtimeVersion>
+    <WasmtimeVersion Condition="'$(WasmtimeVersion)'==''">0.22.0</WasmtimeVersion>
     <WasmtimePackageVersion Condition="'$(DevBuild)'=='true'">$(WasmtimeVersion)-preview1-dev</WasmtimePackageVersion>
     <WasmtimePackageVersion Condition="'$(WasmtimePackageVersion)'==''">$(WasmtimeVersion)-preview1</WasmtimePackageVersion>
   </PropertyGroup>

README.md

@@ -24,10 +24,10 @@
 
 ## Installation
 
-You can add a package reference with the [.NET Core SDK](https://dotnet.microsoft.com/):
+You can add a package reference with the [.NET SDK](https://dotnet.microsoft.com/):
 
 ```text
-$ dotnet add package --version 0.21.0-preview1 wasmtime
+$ dotnet add package --version 0.22.0-preview1 wasmtime
 ```
 
 _Note that the `--version` option is required because the package is currently prerelease._
@@ -54,7 +54,7 @@ $ dotnet new console
 Next, add a reference to the [Wasmtime package](https://www.nuget.org/packages/Wasmtime):
 
 ```
-$ dotnet add package --version 0.21.0-preview1 wasmtime
+$ dotnet add package --version 0.22.0-preview1 wasmtime
 ```
 
 Replace the contents of `Program.cs` with the following code:

benchmarks/simple/simple.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>netcoreapp3.1</TargetFramework>
+    <TargetFramework>net5.0</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>

docs/articles/intro.md

@@ -4,7 +4,7 @@
 
 The [.NET embedding of Wasmtime](https://github.com/bytecodealliance/wasmtime-dotnet) enables .NET developers to easily instantiate and execute WebAssembly modules using Wasmtime.
 
-For this tutorial, we will create a WebAssembly module and use that WebAssembly module from a .NET Core 3.1 application.
+For this tutorial, we will create a WebAssembly module and use that WebAssembly module from a .NET 5 application.
 
 # A simple WebAssembly module
 
@@ -23,13 +23,13 @@ This module simply imports a `hello` function from the host and exports a `run`
 
 # Using the WebAssembly module from .NET
 
-## Installing a .NET Core 3.0 SDK
+## Installing a .NET 5 SDK
 
-Install a [.NET Core 3.1 SDK](https://dotnet.microsoft.com/download/dotnet-core/3.1) for your platform if you haven't already.
+Install a [.NET 5 SDK](https://dotnet.microsoft.com/download/dotnet/5.0) for your platform if you haven't already.
 
 This will add a `dotnet` command to your PATH.
 
-## Creating the .NET Core project
+## Creating the .NET project
 
 The .NET program will be a simple console application, so create a new console project with `dotnet new`:
 
@@ -44,7 +44,7 @@ dotnet new console
 To use the .NET embedding of Wasmtime from the project, we need to add a reference to the [Wasmtime NuGet package](https://www.nuget.org/packages/Wasmtime):
 
 ```text
-dotnet add package --version 0.21.0-preview1 wasmtime
+dotnet add package --version 0.22.0-preview1 wasmtime
 ```
 
 _Note that the `--version` option is required because the package is currently prerelease._
@@ -100,7 +100,7 @@ Use `dotnet build` to build the .NET application:
 dotnet build
 ```
 
-This will create a `tutorial` (or `tutorial.exe` on Windows) executable in the `bin/Debug/netcoreapp3.1` directory that implements the .NET Core application.
+This will create a `tutorial` (or `tutorial.exe` on Windows) executable in the `bin/Debug/net5.0` directory that implements the .NET application.
 
 ## Running the .NET application
 

examples/externref/externref.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>netcoreapp3.1</TargetFramework>
+    <TargetFramework>net5.0</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>

examples/funcref/funcref.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>netcoreapp3.1</TargetFramework>
+    <TargetFramework>net5.0</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>

examples/global/Program.cs

@@ -16,7 +16,8 @@ static void Main(string[] args)
             using var function = host.DefineFunction(
                 "",
                 "print_global",
-                () => {
+                () =>
+                {
                     Console.WriteLine($"The value of the global is: {global.Value}.");
                 }
             );

examples/global/global.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>netcoreapp3.1</TargetFramework>
+    <TargetFramework>net5.0</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>

examples/hello/hello.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>netcoreapp3.1</TargetFramework>
+    <TargetFramework>net5.0</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>

examples/linking/Program.cs

@@ -0,0 +1,31 @@
+using System;
+using Wasmtime;
+
+namespace Example
+{
+    class Program
+    {
+        static void Main(string[] args)
+        {
+            using var engine = new EngineBuilder().WithModuleLinking(true).Build();
+            using var module = Module.FromTextFile(engine, "name.wat");
+            using var program = Module.FromTextFile(engine, "program.wat");
+
+            using var store = new Store(engine);
+            using var host = new Host(store);
+
+            using var memory = host.DefineMemory("", "mem");
+
+            host.DefineInstance("", "inst", module.Instantiate(store, memory));
+
+            host.DefineFunction("", "print", (Caller caller, int addr, int len) =>
+            {
+                Console.WriteLine(caller.GetMemory("mem").ReadString(addr, len));
+            });
+
+            using dynamic instance = host.Instantiate(program);
+
+            instance.run();
+        }
+    }
+}

examples/linking/linking.csproj

@@ -0,0 +1,12 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net5.0</TargetFramework>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\..\src\Wasmtime.csproj" />
+  </ItemGroup>
+
+</Project>

examples/linking/name.wat

@@ -0,0 +1,21 @@
+(module
+  (import "" "mem" (memory 1))
+  (func $name (export "write") (param i32) (result i32)
+    local.get 0
+    i32.const 119 ;;; w
+    i32.store offset=0 align=1
+    local.get 0
+    i32.const 111 ;;; o
+    i32.store offset=1 align=1
+    local.get 0
+    i32.const 114 ;;; r
+    i32.store offset=2 align=1
+    local.get 0
+    i32.const 108 ;;; l
+    i32.store offset=3 align=1
+    local.get 0
+    i32.const 100 ;;; d
+    i32.store offset=4 align=1
+    i32.const 5
+  )
+)

examples/linking/program.wat

@@ -0,0 +1,21 @@
+(module
+  (import "" "print" (func $print (param i32 i32)))
+  (import "" "inst" (instance $inst (export "write" (func $write (param i32) (result i32)))))
+  (import "" "mem" (memory 1))
+  (export "mem" (memory 0))
+  (func (export "run") (local i32)
+    i32.const 6
+    call $inst.$write
+    i32.const 6
+    i32.add
+    local.tee 0
+    i32.const 33 ;;; !
+    i32.store align=1
+    i32.const 0
+    local.get 0
+    i32.const 1
+    i32.add
+    call $print
+  )
+  (data (i32.const 0) "Hello ")
+)

examples/memory/Program.cs

@@ -14,7 +14,8 @@ static void Main(string[] args)
             using var function = host.DefineFunction(
                 "",
                 "log",
-                (Caller caller, int address, int length) => {
+                (Caller caller, int address, int length) =>
+                {
                     var message = caller.GetMemory("mem").ReadString(address, length);
                     Console.WriteLine($"Message from WebAssembly: {message}");
                 }

examples/memory/memory.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>netcoreapp3.1</TargetFramework>
+    <TargetFramework>net5.0</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>

examples/table/table.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>netcoreapp3.1</TargetFramework>
+    <TargetFramework>net5.0</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>

src/EngineBuilder.cs

@@ -178,6 +178,12 @@ public EngineBuilder WithOptimizationLevel(OptimizationLevel level)
             return this;
         }
 
+        public EngineBuilder WithModuleLinking(bool enable)
+        {
+            _enableModuleLinking = enable;
+            return this;
+        }
+
         /// <summary>
         /// Builds the <see cref="Engine" /> instance.
         /// </summary>
@@ -216,6 +222,11 @@ public Engine Build()
                 Interop.wasmtime_config_wasm_multi_value_set(config, _enableMultiValue.Value);
             }
 
+            if (_enableModuleLinking.HasValue)
+            {
+                Interop.wasmtime_config_wasm_module_linking_set(config, _enableModuleLinking.Value);
+            }
+
             if (_strategy.HasValue)
             {
                 Interop.wasmtime_config_strategy_set(config, _strategy.Value);
@@ -240,6 +251,7 @@ public Engine Build()
         private bool? _enableSIMD;
         private bool? _enableBulkMemory;
         private bool? _enableMultiValue;
+        private bool? _enableModuleLinking;
         private Interop.wasmtime_strategy_t? _strategy;
         private bool? _enableCraneliftDebugVerifier;
         private Interop.wasmtime_opt_level_t? _optLevel;

src/Exports/Export.cs

@@ -4,7 +4,7 @@
 namespace Wasmtime.Exports
 {
     /// <summary>
-    /// Represents an export of a WebAssembly module.
+    /// Represents an export of a WebAssembly module or instance.
     /// </summary>
     public abstract class Export
     {
@@ -13,7 +13,14 @@ internal Export(IntPtr exportType)
             unsafe
             {
                 var name = Interop.wasm_exporttype_name(exportType);
-                Name = Marshal.PtrToStringUTF8((IntPtr)name->data, (int)name->size);
+                if (name->size == UIntPtr.Zero)
+                {
+                    Name = String.Empty;
+                }
+                else
+                {
+                    Name = Marshal.PtrToStringUTF8((IntPtr)name->data, (int)name->size);
+                }
             }
         }