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Upgrade to WasmEdge-Go v0.14.0

Due to the WasmEdge-Go API breaking changes, this document shows the guideline of programming with WasmEdge-Go API to upgrade from the v0.13.5 to the v0.14.0 version.

Concepts​

  1. wasmedge.ValType and wasmedge.RefType const values are replaced by the wasmedge.ValType struct.

    Removed wasmedge.ValType and wasmedge.RefType const values, and introduced the wasmedge.ValType struct.

    • Added the wasmedge.NewValTypeI32() API to replace the wasmedge.ValType_I32 const value.
    • Added the wasmedge.NewValTypeI64() API to replace the wasmedge.ValType_I64 const value.
    • Added the wasmedge.NewValTypeF32() API to replace the wasmedge.ValType_F32 const value.
    • Added the wasmedge.NewValTypeF64() API to replace the wasmedge.ValType_F64 const value.
    • Added the wasmedge.NewValTypeV128() API to replace the wasmedge.ValType_V128 const value.
    • Added the wasmedge.NewValTypeFuncRef() API to replace the wasmedge.ValType_FuncRef const value.
    • Added the wasmedge.NewValTypeExternRef() API to replace the wasmedge.ValType_ExterunRef const value.

    The wasmedge.ValType struct provides the series member functions to check the value type.

    Besides, the APIs related to the value types are also updated:

    • wasmedge.NewFunctionType() accepts the new []*wasmedge.ValType for parameters now.
    • (*wasmedge.FunctionType).GetParameters() returns the new []*wasmedge.ValType now.
    • (*wasmedge.FunctionType).GetReturns() returns the new []*wasmedge.ValType now.
    • wasmedge.NewTableType() accepts the new *wasmedge.ValType instead of wasmedge.RefType for parameters now.
    • (*wasmedge.TableType).GetRefType() returns the new *wasmedge.ValType now.
    • wasmedge.NewGlobalType() accepts the new *wasmedge.ValType for parameters now.
    • (*wasmedge.GlobalType).GetValType() returns the new *wasmedge.ValType now.

    For the examples of the new wasmedge.ValType struct and affacted APIs, please refer to the example below.

  2. Developers should handle the error when calling (*wasmedge.Global).SetValue() API.

    With the GC and typed-function references proposals, there are new reference types that accepts non-nullable values. Therefore, when setting value into a global instance, the error occurs if developers set a null value into a non-nullable value type global. Developers should detect and handle the error when setting value into a global instance now.

Before the version v0.13.5, developers can use the const value of value types with function type APIs, and reference types with table type APIs:

// Create a function type: {i32, i64, funcref} -> {f32}
functype := wasmedge.NewFunctionType(
    []wasmedge.ValType{
        wasmedge.ValType_I32,
        wasmedge.ValType_I64,
        wasmedge.ValType_FuncRef,
    },
    []wasmedge.ValType{
        wasmedge.ValType_F32,
    })

// Get the parameter types
var ptypes []wasmedge.ValType = functype.GetParameters()
if ptypes[0] == wasmedge.ValType_I32 {
    // This will be true here.
    // ...
} 
functype.Release()

// Create a table type: {min: 1}, externref
lim := wasmedge.NewLimit(1)
tabtype := wasmedge.NewTableType(wasmedge.RefType_ExternRef, lim)

// Get the reference type
if tabtype.GetRefType() == wasmedge.RefType_ExternRef {
    // This will be true here.
    // ...
}
tabtype.Release()

After v0.14.0, developers should use the wasmedge.ValType related APIs to create the value types.

// Create a function type: {i32, i64, funcref} -> {f32}
functype := wasmedge.NewFunctionType(
    []*wasmedge.ValType{
        wasmedge.NewValTypeI32(),
        wasmedge.NewValTypeI64(),
        wasmedge.NewValTypeFuncRef(),
    },
    []*wasmedge.ValType{
        wasmedge.NewValTypeF32,
    })

// Get the parameter types
var ptypes []*wasmedge.ValType = functype.GetParameters()
if ptypes[0].IsI32() {
    // This will be true here.
    // ...
} 
functype.Release()

// Create a table type: {min: 1}, externref
lim := wasmedge.NewLimit(1)
tabtype := wasmedge.NewTableType(wasmedge.NewValTypeExternRef(), lim)

// Get the reference type
if tabtype.GetRefType().IsExternRef() {
    // This will be true here.
    // ...
}
tabtype.Release()