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