github.com/bananabytelabs/wazero@v0.0.0-20240105073314-54b22a776da8/internal/testing/binaryencoding/import.go (about)

     1  package binaryencoding
     2  
     3  import (
     4  	"fmt"
     5  
     6  	"github.com/bananabytelabs/wazero/internal/leb128"
     7  	"github.com/bananabytelabs/wazero/internal/wasm"
     8  )
     9  
    10  // EncodeImport returns the wasm.Import encoded in WebAssembly 1.0 (20191205) Binary Format.
    11  //
    12  // See https://www.w3.org/TR/2019/REC-wasm-core-1-20191205/#binary-import
    13  func EncodeImport(i *wasm.Import) []byte {
    14  	data := encodeSizePrefixed([]byte(i.Module))
    15  	data = append(data, encodeSizePrefixed([]byte(i.Name))...)
    16  	data = append(data, i.Type)
    17  	switch i.Type {
    18  	case wasm.ExternTypeFunc:
    19  		data = append(data, leb128.EncodeUint32(i.DescFunc)...)
    20  	case wasm.ExternTypeTable:
    21  		data = append(data, wasm.RefTypeFuncref)
    22  		data = append(data, EncodeLimitsType(i.DescTable.Min, i.DescTable.Max)...)
    23  	case wasm.ExternTypeMemory:
    24  		maxPtr := &i.DescMem.Max
    25  		if !i.DescMem.IsMaxEncoded {
    26  			maxPtr = nil
    27  		}
    28  		data = append(data, EncodeLimitsType(i.DescMem.Min, maxPtr)...)
    29  	case wasm.ExternTypeGlobal:
    30  		g := i.DescGlobal
    31  		var mutable byte
    32  		if g.Mutable {
    33  			mutable = 1
    34  		}
    35  		data = append(data, g.ValType, mutable)
    36  	default:
    37  		panic(fmt.Errorf("invalid externtype: %s", wasm.ExternTypeName(i.Type)))
    38  	}
    39  	return data
    40  }