all: implement proto1 weak fields
This implements generation of and reflection support for weak fields.
Weak fields are a proto1 feature where the "weak" option can be specified
on a singular message field. A weak reference results in generated code
that does not directly link in the dependency containing the weak message.
Weak field support is not added to any of the serialization logic.
Change-Id: I08ccfa72bc80b2ffb6af527a1677a0a81dcf33fb
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/185399
Reviewed-by: Damien Neil <dneil@google.com>
diff --git a/internal/impl/message.go b/internal/impl/message.go
index 2e8d185..5b4beb0 100644
--- a/internal/impl/message.go
+++ b/internal/impl/message.go
@@ -120,18 +120,21 @@
type (
SizeCache = int32
+ WeakFields = map[int32]piface.MessageV1
UnknownFields = []byte
ExtensionFields = map[int32]ExtensionField
)
var (
sizecacheType = reflect.TypeOf(SizeCache(0))
+ weakFieldsType = reflect.TypeOf(WeakFields(nil))
unknownFieldsType = reflect.TypeOf(UnknownFields(nil))
extensionFieldsType = reflect.TypeOf(ExtensionFields(nil))
)
type structInfo struct {
sizecacheOffset offset
+ weakOffset offset
unknownOffset offset
extensionOffset offset
@@ -144,6 +147,7 @@
func (mi *MessageInfo) makeStructInfo(t reflect.Type) structInfo {
si := structInfo{
sizecacheOffset: invalidOffset,
+ weakOffset: invalidOffset,
unknownOffset: invalidOffset,
extensionOffset: invalidOffset,
@@ -159,6 +163,9 @@
if f, _ := t.FieldByName("XXX_sizecache"); f.Type == sizecacheType {
si.sizecacheOffset = offsetOf(f, mi.Exporter)
}
+ if f, _ := t.FieldByName("XXX_weak"); f.Type == weakFieldsType {
+ si.weakOffset = offsetOf(f, mi.Exporter)
+ }
if f, _ := t.FieldByName("unknownFields"); f.Type == unknownFieldsType {
si.unknownOffset = offsetOf(f, mi.Exporter)
}
@@ -235,6 +242,8 @@
fi = fieldInfoForMap(fd, fs, mi.Exporter)
case fd.IsList():
fi = fieldInfoForList(fd, fs, mi.Exporter)
+ case fd.IsWeak():
+ fi = fieldInfoForWeakMessage(fd, si.weakOffset)
case fd.Kind() == pref.MessageKind || fd.Kind() == pref.GroupKind:
fi = fieldInfoForMessage(fd, fs, mi.Exporter)
default: