working commit

vendor/github.com/tetratelabs/wabin/binary/export.go

@@ -0,0 +1,43 @@
+package binary
+
+import (
+	"bytes"
+	"fmt"
+
+	"github.com/tetratelabs/wabin/leb128"
+	"github.com/tetratelabs/wabin/wasm"
+)
+
+func decodeExport(r *bytes.Reader) (i *wasm.Export, err error) {
+	i = &wasm.Export{}
+
+	if i.Name, _, err = decodeUTF8(r, "export name"); err != nil {
+		return nil, err
+	}
+
+	b, err := r.ReadByte()
+	if err != nil {
+		return nil, fmt.Errorf("error decoding export kind: %w", err)
+	}
+
+	i.Type = b
+	switch i.Type {
+	case wasm.ExternTypeFunc, wasm.ExternTypeTable, wasm.ExternTypeMemory, wasm.ExternTypeGlobal:
+		if i.Index, _, err = leb128.DecodeUint32(r); err != nil {
+			return nil, fmt.Errorf("error decoding export index: %w", err)
+		}
+	default:
+		return nil, fmt.Errorf("%w: invalid byte for exportdesc: %#x", ErrInvalidByte, b)
+	}
+	return
+}
+
+// encodeExport returns the wasm.Export encoded in WebAssembly Binary Format.
+//
+// See https://www.w3.org/TR/2019/REC-wasm-core-1-20191205/#export-section%E2%91%A0
+func encodeExport(i *wasm.Export) []byte {
+	data := encodeSizePrefixed([]byte(i.Name))
+	data = append(data, i.Type)
+	data = append(data, leb128.EncodeUint32(i.Index)...)
+	return data
+}