1package binary
 2
 3import (
 4	"bytes"
 5	"fmt"
 6
 7	"github.com/tetratelabs/wazero/api"
 8	"github.com/tetratelabs/wazero/internal/wasm"
 9)
10
11// decodeTable returns the wasm.Table decoded with the WebAssembly 1.0 (20191205) Binary Format.
12//
13// See https://www.w3.org/TR/2019/REC-wasm-core-1-20191205/#binary-table
14func decodeTable(r *bytes.Reader, enabledFeatures api.CoreFeatures, ret *wasm.Table) (err error) {
15	ret.Type, err = r.ReadByte()
16	if err != nil {
17		return fmt.Errorf("read leading byte: %v", err)
18	}
19
20	if ret.Type != wasm.RefTypeFuncref {
21		if err = enabledFeatures.RequireEnabled(api.CoreFeatureReferenceTypes); err != nil {
22			return fmt.Errorf("table type funcref is invalid: %w", err)
23		}
24	}
25
26	var shared bool
27	ret.Min, ret.Max, shared, err = decodeLimitsType(r)
28	if err != nil {
29		return fmt.Errorf("read limits: %v", err)
30	}
31	if ret.Min > wasm.MaximumFunctionIndex {
32		return fmt.Errorf("table min must be at most %d", wasm.MaximumFunctionIndex)
33	}
34	if ret.Max != nil {
35		if *ret.Max < ret.Min {
36			return fmt.Errorf("table size minimum must not be greater than maximum")
37		}
38	}
39	if shared {
40		return fmt.Errorf("tables cannot be marked as shared")
41	}
42	return
43}