working commit

2026-03-13 19:02:42 +02:00
parent bebbf79c7a
commit 5c1da77f4c
1329 changed files with 314708 additions and 39 deletions
@@ -0,0 +1,78 @@
+package binary
+
+import (
+	"bytes"
+	"fmt"
+
+	"github.com/tetratelabs/wabin/leb128"
+	"github.com/tetratelabs/wabin/wasm"
+)
+
+func decodeImport(
+	r *bytes.Reader,
+	idx uint32,
+	features wasm.CoreFeatures,
+) (i *wasm.Import, err error) {
+	i = &wasm.Import{}
+	if i.Module, _, err = decodeUTF8(r, "import module"); err != nil {
+		return nil, fmt.Errorf("import[%d] error decoding module: %w", idx, err)
+	}
+
+	if i.Name, _, err = decodeUTF8(r, "import name"); err != nil {
+		return nil, fmt.Errorf("import[%d] error decoding name: %w", idx, err)
+	}
+
+	b, err := r.ReadByte()
+	if err != nil {
+		return nil, fmt.Errorf("import[%d] error decoding type: %w", idx, err)
+	}
+	i.Type = b
+	switch i.Type {
+	case wasm.ExternTypeFunc:
+		i.DescFunc, _, err = leb128.DecodeUint32(r)
+	case wasm.ExternTypeTable:
+		i.DescTable, err = decodeTable(r, features)
+	case wasm.ExternTypeMemory:
+		i.DescMem, err = decodeMemory(r)
+	case wasm.ExternTypeGlobal:
+		i.DescGlobal, err = decodeGlobalType(r)
+	default:
+		err = fmt.Errorf("%w: invalid byte for importdesc: %#x", ErrInvalidByte, b)
+	}
+	if err != nil {
+		return nil, fmt.Errorf("import[%d] %s[%s.%s]: %w", idx, wasm.ExternTypeName(i.Type), i.Module, i.Name, err)
+	}
+	return
+}
+
+// encodeImport returns the wasm.Import encoded in WebAssembly Binary Format.
+//
+// See https://www.w3.org/TR/2019/REC-wasm-core-1-20191205/#binary-import
+func encodeImport(i *wasm.Import) []byte {
+	data := encodeSizePrefixed([]byte(i.Module))
+	data = append(data, encodeSizePrefixed([]byte(i.Name))...)
+	data = append(data, i.Type)
+	switch i.Type {
+	case wasm.ExternTypeFunc:
+		data = append(data, leb128.EncodeUint32(i.DescFunc)...)
+	case wasm.ExternTypeTable:
+		data = append(data, wasm.RefTypeFuncref)
+		data = append(data, encodeLimitsType(i.DescTable.Min, i.DescTable.Max)...)
+	case wasm.ExternTypeMemory:
+		maxPtr := &i.DescMem.Max
+		if !i.DescMem.IsMaxEncoded {
+			maxPtr = nil
+		}
+		data = append(data, encodeLimitsType(i.DescMem.Min, maxPtr)...)
+	case wasm.ExternTypeGlobal:
+		g := i.DescGlobal
+		var mutable byte
+		if g.Mutable {
+			mutable = 1
+		}
+		data = append(data, g.ValType, mutable)
+	default:
+		panic(fmt.Errorf("invalid externtype: %s", wasm.ExternTypeName(i.Type)))
+	}
+	return data
+}