diff options
Diffstat (limited to 'vendor/google.golang.org/protobuf/internal/impl/legacy_extension.go')
| -rw-r--r-- | vendor/google.golang.org/protobuf/internal/impl/legacy_extension.go | 175 |
1 files changed, 175 insertions, 0 deletions
diff --git a/vendor/google.golang.org/protobuf/internal/impl/legacy_extension.go b/vendor/google.golang.org/protobuf/internal/impl/legacy_extension.go new file mode 100644 index 000000000..61757ce50 --- /dev/null +++ b/vendor/google.golang.org/protobuf/internal/impl/legacy_extension.go @@ -0,0 +1,175 @@ +// Copyright 2018 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package impl + +import ( + "reflect" + + "google.golang.org/protobuf/internal/descopts" + "google.golang.org/protobuf/internal/encoding/messageset" + ptag "google.golang.org/protobuf/internal/encoding/tag" + "google.golang.org/protobuf/internal/filedesc" + "google.golang.org/protobuf/internal/pragma" + pref "google.golang.org/protobuf/reflect/protoreflect" + preg "google.golang.org/protobuf/reflect/protoregistry" + piface "google.golang.org/protobuf/runtime/protoiface" +) + +func (xi *ExtensionInfo) initToLegacy() { + xd := xi.desc + var parent piface.MessageV1 + messageName := xd.ContainingMessage().FullName() + if mt, _ := preg.GlobalTypes.FindMessageByName(messageName); mt != nil { + // Create a new parent message and unwrap it if possible. + mv := mt.New().Interface() + t := reflect.TypeOf(mv) + if mv, ok := mv.(unwrapper); ok { + t = reflect.TypeOf(mv.protoUnwrap()) + } + + // Check whether the message implements the legacy v1 Message interface. + mz := reflect.Zero(t).Interface() + if mz, ok := mz.(piface.MessageV1); ok { + parent = mz + } + } + + // Determine the v1 extension type, which is unfortunately not the same as + // the v2 ExtensionType.GoType. + extType := xi.goType + switch extType.Kind() { + case reflect.Bool, reflect.Int32, reflect.Int64, reflect.Uint32, reflect.Uint64, reflect.Float32, reflect.Float64, reflect.String: + extType = reflect.PtrTo(extType) // T -> *T for singular scalar fields + } + + // Reconstruct the legacy enum full name. + var enumName string + if xd.Kind() == pref.EnumKind { + enumName = legacyEnumName(xd.Enum()) + } + + // Derive the proto file that the extension was declared within. + var filename string + if fd := xd.ParentFile(); fd != nil { + filename = fd.Path() + } + + // For MessageSet extensions, the name used is the parent message. + name := xd.FullName() + if messageset.IsMessageSetExtension(xd) { + name = name.Parent() + } + + xi.ExtendedType = parent + xi.ExtensionType = reflect.Zero(extType).Interface() + xi.Field = int32(xd.Number()) + xi.Name = string(name) + xi.Tag = ptag.Marshal(xd, enumName) + xi.Filename = filename +} + +// initFromLegacy initializes an ExtensionInfo from +// the contents of the deprecated exported fields of the type. +func (xi *ExtensionInfo) initFromLegacy() { + // The v1 API returns "type incomplete" descriptors where only the + // field number is specified. In such a case, use a placeholder. + if xi.ExtendedType == nil || xi.ExtensionType == nil { + xd := placeholderExtension{ + name: pref.FullName(xi.Name), + number: pref.FieldNumber(xi.Field), + } + xi.desc = extensionTypeDescriptor{xd, xi} + return + } + + // Resolve enum or message dependencies. + var ed pref.EnumDescriptor + var md pref.MessageDescriptor + t := reflect.TypeOf(xi.ExtensionType) + isOptional := t.Kind() == reflect.Ptr && t.Elem().Kind() != reflect.Struct + isRepeated := t.Kind() == reflect.Slice && t.Elem().Kind() != reflect.Uint8 + if isOptional || isRepeated { + t = t.Elem() + } + switch v := reflect.Zero(t).Interface().(type) { + case pref.Enum: + ed = v.Descriptor() + case enumV1: + ed = LegacyLoadEnumDesc(t) + case pref.ProtoMessage: + md = v.ProtoReflect().Descriptor() + case messageV1: + md = LegacyLoadMessageDesc(t) + } + + // Derive basic field information from the struct tag. + var evs pref.EnumValueDescriptors + if ed != nil { + evs = ed.Values() + } + fd := ptag.Unmarshal(xi.Tag, t, evs).(*filedesc.Field) + + // Construct a v2 ExtensionType. + xd := &filedesc.Extension{L2: new(filedesc.ExtensionL2)} + xd.L0.ParentFile = filedesc.SurrogateProto2 + xd.L0.FullName = pref.FullName(xi.Name) + xd.L1.Number = pref.FieldNumber(xi.Field) + xd.L1.Cardinality = fd.L1.Cardinality + xd.L1.Kind = fd.L1.Kind + xd.L2.IsPacked = fd.L1.IsPacked + xd.L2.Default = fd.L1.Default + xd.L1.Extendee = Export{}.MessageDescriptorOf(xi.ExtendedType) + xd.L2.Enum = ed + xd.L2.Message = md + + // Derive real extension field name for MessageSets. + if messageset.IsMessageSet(xd.L1.Extendee) && md.FullName() == xd.L0.FullName { + xd.L0.FullName = xd.L0.FullName.Append(messageset.ExtensionName) + } + + tt := reflect.TypeOf(xi.ExtensionType) + if isOptional { + tt = tt.Elem() + } + xi.goType = tt + xi.desc = extensionTypeDescriptor{xd, xi} +} + +type placeholderExtension struct { + name pref.FullName + number pref.FieldNumber +} + +func (x placeholderExtension) ParentFile() pref.FileDescriptor { return nil } +func (x placeholderExtension) Parent() pref.Descriptor { return nil } +func (x placeholderExtension) Index() int { return 0 } +func (x placeholderExtension) Syntax() pref.Syntax { return 0 } +func (x placeholderExtension) Name() pref.Name { return x.name.Name() } +func (x placeholderExtension) FullName() pref.FullName { return x.name } +func (x placeholderExtension) IsPlaceholder() bool { return true } +func (x placeholderExtension) Options() pref.ProtoMessage { return descopts.Field } +func (x placeholderExtension) Number() pref.FieldNumber { return x.number } +func (x placeholderExtension) Cardinality() pref.Cardinality { return 0 } +func (x placeholderExtension) Kind() pref.Kind { return 0 } +func (x placeholderExtension) HasJSONName() bool { return false } +func (x placeholderExtension) JSONName() string { return "" } +func (x placeholderExtension) HasPresence() bool { return false } +func (x placeholderExtension) HasOptionalKeyword() bool { return false } +func (x placeholderExtension) IsExtension() bool { return true } +func (x placeholderExtension) IsWeak() bool { return false } +func (x placeholderExtension) IsPacked() bool { return false } +func (x placeholderExtension) IsList() bool { return false } +func (x placeholderExtension) IsMap() bool { return false } +func (x placeholderExtension) MapKey() pref.FieldDescriptor { return nil } +func (x placeholderExtension) MapValue() pref.FieldDescriptor { return nil } +func (x placeholderExtension) HasDefault() bool { return false } +func (x placeholderExtension) Default() pref.Value { return pref.Value{} } +func (x placeholderExtension) DefaultEnumValue() pref.EnumValueDescriptor { return nil } +func (x placeholderExtension) ContainingOneof() pref.OneofDescriptor { return nil } +func (x placeholderExtension) ContainingMessage() pref.MessageDescriptor { return nil } +func (x placeholderExtension) Enum() pref.EnumDescriptor { return nil } +func (x placeholderExtension) Message() pref.MessageDescriptor { return nil } +func (x placeholderExtension) ProtoType(pref.FieldDescriptor) { return } +func (x placeholderExtension) ProtoInternal(pragma.DoNotImplement) { return } |