72f16d21eb
This commit adds support for multiple tables per module. Notably, if the WithFeatureReferenceTypes is enabled, call_indirect, table.init and table.copy instructions can reference non-zero indexed tables. part of #484 Signed-off-by: Takeshi Yoneda <takeshi@tetrate.io>
48 lines
1.4 KiB
Go
48 lines
1.4 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/wazero/internal/wasm"
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)
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// decodeTable returns the wasm.Table decoded with the WebAssembly 1.0 (20191205) Binary Format.
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//
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// See https://www.w3.org/TR/2019/REC-wasm-core-1-20191205/#binary-table
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func decodeTable(r *bytes.Reader, enabledFeatures wasm.Features) (*wasm.Table, error) {
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tableType, err := r.ReadByte()
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if err != nil {
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return nil, fmt.Errorf("read leading byte: %v", err)
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}
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if tableType != wasm.RefTypeFuncref {
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if err := enabledFeatures.Require(wasm.FeatureReferenceTypes); err != nil {
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return nil, fmt.Errorf("table type funcref is invalid: %w", err)
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}
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}
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min, max, err := decodeLimitsType(r)
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if err != nil {
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return nil, fmt.Errorf("read limits: %v", err)
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}
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if min > wasm.MaximumFunctionIndex {
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return nil, fmt.Errorf("table min must be at most %d", wasm.MaximumFunctionIndex)
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}
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if max != nil {
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if *max < min {
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return nil, fmt.Errorf("table size minimum must not be greater than maximum")
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} else if *max > wasm.MaximumFunctionIndex {
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return nil, fmt.Errorf("table max must be at most %d", wasm.MaximumFunctionIndex)
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}
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}
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return &wasm.Table{Min: min, Max: max, Type: tableType}, nil
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}
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// encodeTable returns the wasm.Table encoded in WebAssembly 1.0 (20191205) Binary Format.
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//
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// See https://www.w3.org/TR/2019/REC-wasm-core-1-20191205/#binary-table
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func encodeTable(i *wasm.Table) []byte {
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return append([]byte{i.Type}, encodeLimitsType(i.Min, i.Max)...)
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}
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