c3ff16d596
Signed-off-by: Adrian Cole <adrian@tetrate.io> Signed-off-by: Takeshi Yoneda <takeshi@tetrate.io>
100 lines
2.9 KiB
Go
100 lines
2.9 KiB
Go
package wasm
|
|
|
|
import (
|
|
"fmt"
|
|
"strings"
|
|
)
|
|
|
|
// Features are the currently enabled features.
|
|
//
|
|
// Note: This is a bit flag until we have too many (>63). Flags are simpler to manage in multiple places than a map.
|
|
type Features uint64
|
|
|
|
// Features20191205 include those finished in WebAssembly 1.0 (20191205).
|
|
//
|
|
// See https://github.com/WebAssembly/proposals/blob/main/finished-proposals.md
|
|
// See https://www.w3.org/TR/2019/REC-wasm-core-1-20191205
|
|
const Features20191205 = FeatureMutableGlobal
|
|
|
|
// FeaturesFinished include all supported finished features, regardless of W3C status.
|
|
//
|
|
// See https://github.com/WebAssembly/proposals/blob/main/finished-proposals.md
|
|
const FeaturesFinished = 0xffffffffffffffff
|
|
|
|
const (
|
|
// FeatureMutableGlobal decides if global vars are allowed to be imported or exported (ExternTypeGlobal)
|
|
// See https://github.com/WebAssembly/mutable-global
|
|
FeatureMutableGlobal Features = 1 << iota
|
|
|
|
// FeatureSignExtensionOps decides if parsing should succeed on the following instructions:
|
|
//
|
|
// * OpcodeI32Extend8S
|
|
// * OpcodeI32Extend16S
|
|
// * OpcodeI64Extend8S
|
|
// * OpcodeI64Extend16S
|
|
// * OpcodeI64Extend32S
|
|
//
|
|
// See https://github.com/WebAssembly/spec/blob/main/proposals/sign-extension-ops/Overview.md
|
|
FeatureSignExtensionOps
|
|
|
|
// FeatureMultiValue decides if parsing should succeed on the following:
|
|
//
|
|
// * FunctionType.Results length greater than one.
|
|
// * `block`, `loop` and `if` can be arbitrary function types.
|
|
//
|
|
// See https://github.com/WebAssembly/spec/blob/main/proposals/multi-value/Overview.md
|
|
FeatureMultiValue
|
|
)
|
|
|
|
// Set assigns the value for the given feature.
|
|
func (f Features) Set(feature Features, val bool) Features {
|
|
if val {
|
|
return f | feature
|
|
}
|
|
return f &^ feature
|
|
}
|
|
|
|
// Get returns the value of the given feature.
|
|
func (f Features) Get(feature Features) bool {
|
|
return f&feature != 0
|
|
}
|
|
|
|
// Require fails with a configuration error if the given feature is not enabled
|
|
func (f Features) Require(feature Features) error {
|
|
if f&feature == 0 {
|
|
return fmt.Errorf("feature %q is disabled", feature)
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// String implements fmt.Stringer by returning each enabled feature.
|
|
func (f Features) String() string {
|
|
var builder strings.Builder
|
|
for i := Features(0); i < 63; i++ { // cycle through all bits to reduce code and maintenance
|
|
if f.Get(i) {
|
|
if name := featureName(i); name != "" {
|
|
if builder.Len() > 0 {
|
|
builder.WriteByte('|')
|
|
}
|
|
builder.WriteString(name)
|
|
}
|
|
}
|
|
}
|
|
return builder.String()
|
|
}
|
|
|
|
func featureName(f Features) string {
|
|
switch f {
|
|
case FeatureMutableGlobal:
|
|
// match https://github.com/WebAssembly/mutable-global
|
|
return "mutable-global"
|
|
case FeatureSignExtensionOps:
|
|
// match https://github.com/WebAssembly/spec/blob/main/proposals/sign-extension-ops/Overview.md
|
|
return "sign-extension-ops"
|
|
case FeatureMultiValue:
|
|
// match https://github.com/WebAssembly/spec/blob/main/proposals/multi-value/Overview.md
|
|
return "multi-value"
|
|
}
|
|
return ""
|
|
}
|