deprecated emscripten.Instantiate and it's related functions in favor…

… of InstantiateForModule. rewrote emscripten examples to use InstantiateForModule Signed-off-by: Daniel Lockhart <[email protected]>
tetratelabs · Oct 15, 2023 · 81a8ecf · 81a8ecf
1 parent 44f23e2
commit 81a8ecf
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Showing 2 changed files with 30 additions and 5 deletions.
diff --git a/imports/emscripten/emscripten.go b/imports/emscripten/emscripten.go
@@ -28,6 +28,8 @@ const i32 = wasm.ValueTypeI32
 //
 // This is a simpler function for those who know the module "env" is not
 // already instantiated, and don't need to unload it.
+//
+// Deprecated: Due to Emscripten dynamic import generation, InstantiateForModule should be used instead.
 func MustInstantiate(ctx context.Context, r wazero.Runtime) {
 	if _, err := Instantiate(ctx, r); err != nil {
 		panic(err)
@@ -42,6 +44,8 @@ func MustInstantiate(ctx context.Context, r wazero.Runtime) {
 //   - Failure cases are documented on wazero.Runtime InstantiateModule.
 //   - Closing the wazero.Runtime has the same effect as closing the result.
 //   - To add more functions to the "env" module, use FunctionExporter.
+//
+// Deprecated: Due to Emscripten dynamic import generation, InstantiateForModule should be used instead.
 func Instantiate(ctx context.Context, r wazero.Runtime) (api.Closer, error) {
 	builder := r.NewHostModuleBuilder("env")
 	NewFunctionExporter().ExportFunctions(builder)
@@ -62,6 +66,7 @@ type FunctionExporter interface {
 }
 
 // NewFunctionExporter returns a FunctionExporter object with trace disabled.
+// Deprecated: Due to Emscripten dynamic import generation, NewFunctionExporterForModule should be used instead.
 func NewFunctionExporter() FunctionExporter {
 	return &functionExporter{}
 }

diff --git a/imports/emscripten/emscripten_example_test.go b/imports/emscripten/emscripten_example_test.go
@@ -9,8 +9,11 @@ import (
 	"github.com/tetratelabs/wazero/imports/wasi_snapshot_preview1"
 )
 
+//go:embed testdata/invoke.wasm
+var invokeWasm []byte
+
 // This shows how to instantiate Emscripten function imports.
-func Example_instantiate() {
+func Example_instantiateForModule() {
 	ctx := context.Background()
 
 	r := wazero.NewRuntime(ctx)
@@ -19,8 +22,17 @@ func Example_instantiate() {
 	// Add WASI which is typically required when using Emscripten.
 	wasi_snapshot_preview1.MustInstantiate(ctx, r)
 
-	// Now, add the "env" module to the runtime, Emscripten default imports.
-	emscripten.MustInstantiate(ctx, r)
+	// Compile the WASM so wazero can handle dynamically generated imports.
+	compiled, err := r.CompileModule(ctx, invokeWasm)
+	if err != nil {
+		panic(err)
+	}
+
+	envCloser, err := emscripten.InstantiateForModule(ctx, r, compiled)
+	if err != nil {
+		panic(err)
+	}
+	defer envCloser.Close(ctx) // This closes the env module.
 
 	// Output:
 }
@@ -36,6 +48,15 @@ func Example_functionExporter() {
 	// Add WASI which is typically required when using Emscripten.
 	wasi_snapshot_preview1.MustInstantiate(ctx, r)
 
+	// Compile the WASM so wazero can handle dynamically generated imports.
+	compiled, err := r.CompileModule(ctx, invokeWasm)
+	if err != nil {
+		panic(err)
+	}
+	exporter, err := emscripten.NewFunctionExporterForModule(compiled)
+	if err != nil {
+		panic(err)
+	}
 	// Next, construct your own module builder for "env" with any functions
 	// you need.
 	envBuilder := r.NewHostModuleBuilder("env").
@@ -44,7 +65,6 @@ func Example_functionExporter() {
 		Export("get_int")
 
 	// Now, add Emscripten special function imports into it.
-	emscripten.NewFunctionExporter().ExportFunctions(envBuilder)
-
+	exporter.ExportFunctions(envBuilder)
 	// Output:
 }