engine, interp/wasman: handle the 4 basic value types correctly when …

…calling wasman

Signed-off-by: deadprogram <[email protected]>

engine/instance.go

@@ -1,5 +1,5 @@
 package engine
 
 type Instance interface {
-	Call(name string, args ...interface{}) (interface{}, error)
+	Call(name string, args ...any) (any, error)
 }

interp/wasman/instance.go

@@ -1,53 +1,92 @@
 package wasman
 
 import (
+	"math"
+
 	wasmaneng "github.com/hybridgroup/wasman"
+	"github.com/hybridgroup/wasman/types"
 )
 
 type Instance struct {
 	instance *wasmaneng.Instance
 }
 
-func (i *Instance) Call(name string, args ...interface{}) (interface{}, error) {
+func (i *Instance) Call(name string, args ...any) (any, error) {
 	if len(args) == 0 {
-		results, _, err := i.instance.CallExportedFunc(name)
+		results, types, err := i.instance.CallExportedFunc(name)
 		if err != nil {
 			return nil, err
 		}
-		return results, nil
+		res := decodeResults(results, types)
+		if len(res) == 0 {
+			return nil, nil
+		}
+		if len(res) == 1 {
+			return res[0], nil
+		}
+		return res, nil
+	}
+
+	results, types, err := i.instance.CallExportedFunc(name, encodeArgs(args)...)
+	if err != nil {
+		return nil, err
 	}
 
-	wargs := make([]uint64, len(args))
-	switch args[0].(type) {
+	res := decodeResults(results, types)
+	if len(res) == 0 {
+		return nil, nil
+	}
+	if len(res) == 1 {
+		return res[0], nil
+	}
+	return res, nil
+}
+
+func encodeArgs(args []any) []uint64 {
+	encoded := make([]uint64, 0, len(args))
+	for _, arg := range args {
+		encoded = append(encoded, encodeArg(arg))
+	}
+	return encoded
+}
+
+func encodeArg(arg any) uint64 {
+	switch val := arg.(type) {
 	case int32:
-		for i, v := range args {
-			wargs[i] = uint64(v.(int32))
-		}
-	case uint32:
-		for i, v := range args {
-			wargs[i] = uint64(v.(uint32))
-		}
+		return uint64(val)
 	case int64:
-		for i, v := range args {
-			wargs[i] = uint64(v.(int64))
-		}
-	case uint64:
-		for i, v := range args {
-			wargs[i] = uint64(v.(uint64))
-		}
+		return uint64(val)
 	case float32:
-		for i, v := range args {
-			wargs[i] = uint64(v.(float32))
-		}
+		return uint64(math.Float32bits(val))
 	case float64:
-		for i, v := range args {
-			wargs[i] = uint64(v.(float64))
-		}
+		return uint64(math.Float64bits(val))
+	case uint32:
+		return uint64(val)
+	case uint64:
+		return uint64(val)
 	}
-	results, _, err := i.instance.CallExportedFunc(name, wargs...)
-	if err != nil {
-		return nil, err
+	panic("bad arg type")
+}
+
+func decodeResults(results []uint64, vtypes []types.ValueType) []any {
+	decoded := make([]any, 0, len(results))
+	for i, result := range results {
+		vtype := vtypes[i]
+		decoded = append(decoded, decodeResult(result, vtype))
 	}
+	return decoded
+}
 
-	return results, nil
+func decodeResult(result uint64, vtype types.ValueType) any {
+	switch vtype {
+	case types.ValueTypeF32:
+		return math.Float32frombits(uint32(result))
+	case types.ValueTypeF64:
+		return math.Float64frombits(uint64(result))
+	case types.ValueTypeI32:
+		return int32(result)
+	case types.ValueTypeI64:
+		return int64(result)
+	}
+	panic("unreachable")
 }

interp/wasman/instance_test.go

@@ -0,0 +1,87 @@
+package wasman
+
+import (
+	_ "embed"
+	"testing"
+)
+
+//go:embed tester.wasm
+var wasmData []byte
+
+func TestInstance(t *testing.T) {
+	i := Interpreter{
+		Memory: make([]byte, 65536),
+	}
+	if err := i.Init(); err != nil {
+		t.Errorf("Interpreter.Init() failed: %v", err)
+	}
+
+	if err := i.Load(wasmData); err != nil {
+		t.Errorf("Interpreter.Load() failed: %v", err)
+	}
+
+	inst, err := i.Run()
+	if err != nil {
+		t.Errorf("Interpreter.Run() failed: %v", err)
+	}
+
+	t.Run("Call int32", func(t *testing.T) {
+		results, err := inst.Call("test_int32", int32(1), int32(2))
+		if err != nil {
+			t.Errorf("Instance.Call() failed: %v", err)
+		}
+		if results != int32(3) {
+			t.Errorf("Instance.Call() failed: %v", results)
+		}
+	})
+
+	t.Run("Call uint32", func(t *testing.T) {
+		results, err := inst.Call("test_uint32", uint32(1), uint32(2))
+		if err != nil {
+			t.Errorf("Instance.Call() failed: %v", err)
+		}
+		if uint32(results.(int32)) != uint32(3) {
+			t.Errorf("Instance.Call() failed: %v", results)
+		}
+	})
+
+	t.Run("Call int64", func(t *testing.T) {
+		results, err := inst.Call("test_int64", int64(1), int64(2))
+		if err != nil {
+			t.Errorf("Instance.Call() failed: %v", err)
+		}
+		if results != int64(3) {
+			t.Errorf("Instance.Call() failed: %v", results)
+		}
+	})
+
+	t.Run("Call uint64", func(t *testing.T) {
+		results, err := inst.Call("test_uint64", uint64(1), uint64(2))
+		if err != nil {
+			t.Errorf("Instance.Call() failed: %v", err)
+		}
+		if uint64(results.(int64)) != uint64(3) {
+			t.Errorf("Instance.Call() failed: %v", results)
+		}
+	})
+
+	t.Run("Call float32", func(t *testing.T) {
+		results, err := inst.Call("test_float32", float32(100.2), float32(300.8))
+		if err != nil {
+			t.Errorf("Instance.Call() failed: %v", err)
+		}
+		if results != float32(401.0) {
+			t.Errorf("Instance.Call() failed: %v", results)
+		}
+	})
+
+	t.Run("Call float64", func(t *testing.T) {
+		results, err := inst.Call("test_float64", float64(111.2), float64(333.8))
+		if err != nil {
+			t.Errorf("Instance.Call() failed: %v", err)
+		}
+		if results != float64(445.0) {
+			t.Errorf("Instance.Call() failed: %v", results)
+		}
+	})
+}