all: implement support for proto3 optional semantics
In the upcoming 3.12.x release of protoc, the proto3 language will be
amended to support true presence for scalars. This CL adds support
to both the generator and runtime to support these semantics.
Newly added public API:
protogen.Plugin.SupportedFeatures
protoreflect.FieldDescriptor.HasPresence
protoreflect.FieldDescriptor.HasOptionalKeyword
protoreflect.OneofDescriptor.IsSynthetic
Change-Id: I7c86bf66d0ae56642109beb5f2132184593747ad
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/230698
Reviewed-by: Damien Neil <dneil@google.com>
diff --git a/internal/impl/message_reflect_field.go b/internal/impl/message_reflect_field.go
index 7b87d47..ea6f755 100644
--- a/internal/impl/message_reflect_field.go
+++ b/internal/impl/message_reflect_field.go
@@ -221,7 +221,7 @@
func fieldInfoForScalar(fd pref.FieldDescriptor, fs reflect.StructField, x exporter) fieldInfo {
ft := fs.Type
- nullable := fd.Syntax() == pref.Proto2
+ nullable := fd.HasPresence()
isBytes := ft.Kind() == reflect.Slice && ft.Elem().Kind() == reflect.Uint8
if nullable {
if ft.Kind() != reflect.Ptr && ft.Kind() != reflect.Slice {
@@ -290,9 +290,9 @@
rv.Set(conv.GoValueOf(v))
if isBytes && rv.Len() == 0 {
if nullable {
- rv.Set(emptyBytes) // preserve presence in proto2
+ rv.Set(emptyBytes) // preserve presence
} else {
- rv.Set(nilBytes) // do not preserve presence in proto3
+ rv.Set(nilBytes) // do not preserve presence
}
}
},
@@ -426,11 +426,25 @@
which func(pointer) pref.FieldNumber
}
-func makeOneofInfo(od pref.OneofDescriptor, fs reflect.StructField, x exporter, wrappersByType map[reflect.Type]pref.FieldNumber) *oneofInfo {
- fieldOffset := offsetOf(fs, x)
- return &oneofInfo{
- oneofDesc: od,
- which: func(p pointer) pref.FieldNumber {
+func makeOneofInfo(od pref.OneofDescriptor, si structInfo, x exporter) *oneofInfo {
+ oi := &oneofInfo{oneofDesc: od}
+ if od.IsSynthetic() {
+ fs := si.fieldsByNumber[od.Fields().Get(0).Number()]
+ fieldOffset := offsetOf(fs, x)
+ oi.which = func(p pointer) pref.FieldNumber {
+ if p.IsNil() {
+ return 0
+ }
+ rv := p.Apply(fieldOffset).AsValueOf(fs.Type).Elem()
+ if rv.IsNil() { // valid on either *T or []byte
+ return 0
+ }
+ return od.Fields().Get(0).Number()
+ }
+ } else {
+ fs := si.oneofsByName[od.Name()]
+ fieldOffset := offsetOf(fs, x)
+ oi.which = func(p pointer) pref.FieldNumber {
if p.IsNil() {
return 0
}
@@ -442,7 +456,8 @@
if rv.IsNil() {
return 0
}
- return wrappersByType[rv.Type().Elem()]
- },
+ return si.oneofWrappersByType[rv.Type().Elem()]
+ }
}
+ return oi
}