vendor/google.golang.org/protobuf/internal/impl/legacy_message.go
changeset 256 6d9efbef00a9
child 260 445e01aede7e
equal deleted inserted replaced
255:4f153a23adab 256:6d9efbef00a9
       
     1 // Copyright 2018 The Go Authors. All rights reserved.
       
     2 // Use of this source code is governed by a BSD-style
       
     3 // license that can be found in the LICENSE file.
       
     4 
       
     5 package impl
       
     6 
       
     7 import (
       
     8 	"fmt"
       
     9 	"reflect"
       
    10 	"strings"
       
    11 	"sync"
       
    12 
       
    13 	"google.golang.org/protobuf/internal/descopts"
       
    14 	ptag "google.golang.org/protobuf/internal/encoding/tag"
       
    15 	"google.golang.org/protobuf/internal/errors"
       
    16 	"google.golang.org/protobuf/internal/filedesc"
       
    17 	"google.golang.org/protobuf/internal/strs"
       
    18 	"google.golang.org/protobuf/reflect/protoreflect"
       
    19 	pref "google.golang.org/protobuf/reflect/protoreflect"
       
    20 	"google.golang.org/protobuf/runtime/protoiface"
       
    21 	piface "google.golang.org/protobuf/runtime/protoiface"
       
    22 )
       
    23 
       
    24 // legacyWrapMessage wraps v as a protoreflect.Message,
       
    25 // where v must be a *struct kind and not implement the v2 API already.
       
    26 func legacyWrapMessage(v reflect.Value) pref.Message {
       
    27 	t := v.Type()
       
    28 	if t.Kind() != reflect.Ptr || t.Elem().Kind() != reflect.Struct {
       
    29 		return aberrantMessage{v: v}
       
    30 	}
       
    31 	mt := legacyLoadMessageInfo(t, "")
       
    32 	return mt.MessageOf(v.Interface())
       
    33 }
       
    34 
       
    35 // legacyLoadMessageType dynamically loads a protoreflect.Type for t,
       
    36 // where t must be not implement the v2 API already.
       
    37 // The provided name is used if it cannot be determined from the message.
       
    38 func legacyLoadMessageType(t reflect.Type, name pref.FullName) protoreflect.MessageType {
       
    39 	if t.Kind() != reflect.Ptr || t.Elem().Kind() != reflect.Struct {
       
    40 		return aberrantMessageType{t}
       
    41 	}
       
    42 	return legacyLoadMessageInfo(t, name)
       
    43 }
       
    44 
       
    45 var legacyMessageTypeCache sync.Map // map[reflect.Type]*MessageInfo
       
    46 
       
    47 // legacyLoadMessageInfo dynamically loads a *MessageInfo for t,
       
    48 // where t must be a *struct kind and not implement the v2 API already.
       
    49 // The provided name is used if it cannot be determined from the message.
       
    50 func legacyLoadMessageInfo(t reflect.Type, name pref.FullName) *MessageInfo {
       
    51 	// Fast-path: check if a MessageInfo is cached for this concrete type.
       
    52 	if mt, ok := legacyMessageTypeCache.Load(t); ok {
       
    53 		return mt.(*MessageInfo)
       
    54 	}
       
    55 
       
    56 	// Slow-path: derive message descriptor and initialize MessageInfo.
       
    57 	mi := &MessageInfo{
       
    58 		Desc:          legacyLoadMessageDesc(t, name),
       
    59 		GoReflectType: t,
       
    60 	}
       
    61 
       
    62 	var hasMarshal, hasUnmarshal bool
       
    63 	v := reflect.Zero(t).Interface()
       
    64 	if _, hasMarshal = v.(legacyMarshaler); hasMarshal {
       
    65 		mi.methods.Marshal = legacyMarshal
       
    66 
       
    67 		// We have no way to tell whether the type's Marshal method
       
    68 		// supports deterministic serialization or not, but this
       
    69 		// preserves the v1 implementation's behavior of always
       
    70 		// calling Marshal methods when present.
       
    71 		mi.methods.Flags |= piface.SupportMarshalDeterministic
       
    72 	}
       
    73 	if _, hasUnmarshal = v.(legacyUnmarshaler); hasUnmarshal {
       
    74 		mi.methods.Unmarshal = legacyUnmarshal
       
    75 	}
       
    76 	if _, hasMerge := v.(legacyMerger); hasMerge || (hasMarshal && hasUnmarshal) {
       
    77 		mi.methods.Merge = legacyMerge
       
    78 	}
       
    79 
       
    80 	if mi, ok := legacyMessageTypeCache.LoadOrStore(t, mi); ok {
       
    81 		return mi.(*MessageInfo)
       
    82 	}
       
    83 	return mi
       
    84 }
       
    85 
       
    86 var legacyMessageDescCache sync.Map // map[reflect.Type]protoreflect.MessageDescriptor
       
    87 
       
    88 // LegacyLoadMessageDesc returns an MessageDescriptor derived from the Go type,
       
    89 // which should be a *struct kind and must not implement the v2 API already.
       
    90 //
       
    91 // This is exported for testing purposes.
       
    92 func LegacyLoadMessageDesc(t reflect.Type) pref.MessageDescriptor {
       
    93 	return legacyLoadMessageDesc(t, "")
       
    94 }
       
    95 func legacyLoadMessageDesc(t reflect.Type, name pref.FullName) pref.MessageDescriptor {
       
    96 	// Fast-path: check if a MessageDescriptor is cached for this concrete type.
       
    97 	if mi, ok := legacyMessageDescCache.Load(t); ok {
       
    98 		return mi.(pref.MessageDescriptor)
       
    99 	}
       
   100 
       
   101 	// Slow-path: initialize MessageDescriptor from the raw descriptor.
       
   102 	mv := reflect.Zero(t).Interface()
       
   103 	if _, ok := mv.(pref.ProtoMessage); ok {
       
   104 		panic(fmt.Sprintf("%v already implements proto.Message", t))
       
   105 	}
       
   106 	mdV1, ok := mv.(messageV1)
       
   107 	if !ok {
       
   108 		return aberrantLoadMessageDesc(t, name)
       
   109 	}
       
   110 
       
   111 	// If this is a dynamic message type where there isn't a 1-1 mapping between
       
   112 	// Go and protobuf types, calling the Descriptor method on the zero value of
       
   113 	// the message type isn't likely to work. If it panics, swallow the panic and
       
   114 	// continue as if the Descriptor method wasn't present.
       
   115 	b, idxs := func() ([]byte, []int) {
       
   116 		defer func() {
       
   117 			recover()
       
   118 		}()
       
   119 		return mdV1.Descriptor()
       
   120 	}()
       
   121 	if b == nil {
       
   122 		return aberrantLoadMessageDesc(t, name)
       
   123 	}
       
   124 
       
   125 	// If the Go type has no fields, then this might be a proto3 empty message
       
   126 	// from before the size cache was added. If there are any fields, check to
       
   127 	// see that at least one of them looks like something we generated.
       
   128 	if t.Elem().Kind() == reflect.Struct {
       
   129 		if nfield := t.Elem().NumField(); nfield > 0 {
       
   130 			hasProtoField := false
       
   131 			for i := 0; i < nfield; i++ {
       
   132 				f := t.Elem().Field(i)
       
   133 				if f.Tag.Get("protobuf") != "" || f.Tag.Get("protobuf_oneof") != "" || strings.HasPrefix(f.Name, "XXX_") {
       
   134 					hasProtoField = true
       
   135 					break
       
   136 				}
       
   137 			}
       
   138 			if !hasProtoField {
       
   139 				return aberrantLoadMessageDesc(t, name)
       
   140 			}
       
   141 		}
       
   142 	}
       
   143 
       
   144 	md := legacyLoadFileDesc(b).Messages().Get(idxs[0])
       
   145 	for _, i := range idxs[1:] {
       
   146 		md = md.Messages().Get(i)
       
   147 	}
       
   148 	if name != "" && md.FullName() != name {
       
   149 		panic(fmt.Sprintf("mismatching message name: got %v, want %v", md.FullName(), name))
       
   150 	}
       
   151 	if md, ok := legacyMessageDescCache.LoadOrStore(t, md); ok {
       
   152 		return md.(protoreflect.MessageDescriptor)
       
   153 	}
       
   154 	return md
       
   155 }
       
   156 
       
   157 var (
       
   158 	aberrantMessageDescLock  sync.Mutex
       
   159 	aberrantMessageDescCache map[reflect.Type]protoreflect.MessageDescriptor
       
   160 )
       
   161 
       
   162 // aberrantLoadMessageDesc returns an MessageDescriptor derived from the Go type,
       
   163 // which must not implement protoreflect.ProtoMessage or messageV1.
       
   164 //
       
   165 // This is a best-effort derivation of the message descriptor using the protobuf
       
   166 // tags on the struct fields.
       
   167 func aberrantLoadMessageDesc(t reflect.Type, name pref.FullName) pref.MessageDescriptor {
       
   168 	aberrantMessageDescLock.Lock()
       
   169 	defer aberrantMessageDescLock.Unlock()
       
   170 	if aberrantMessageDescCache == nil {
       
   171 		aberrantMessageDescCache = make(map[reflect.Type]protoreflect.MessageDescriptor)
       
   172 	}
       
   173 	return aberrantLoadMessageDescReentrant(t, name)
       
   174 }
       
   175 func aberrantLoadMessageDescReentrant(t reflect.Type, name pref.FullName) pref.MessageDescriptor {
       
   176 	// Fast-path: check if an MessageDescriptor is cached for this concrete type.
       
   177 	if md, ok := aberrantMessageDescCache[t]; ok {
       
   178 		return md
       
   179 	}
       
   180 
       
   181 	// Slow-path: construct a descriptor from the Go struct type (best-effort).
       
   182 	// Cache the MessageDescriptor early on so that we can resolve internal
       
   183 	// cyclic references.
       
   184 	md := &filedesc.Message{L2: new(filedesc.MessageL2)}
       
   185 	md.L0.FullName = aberrantDeriveMessageName(t, name)
       
   186 	md.L0.ParentFile = filedesc.SurrogateProto2
       
   187 	aberrantMessageDescCache[t] = md
       
   188 
       
   189 	if t.Kind() != reflect.Ptr || t.Elem().Kind() != reflect.Struct {
       
   190 		return md
       
   191 	}
       
   192 
       
   193 	// Try to determine if the message is using proto3 by checking scalars.
       
   194 	for i := 0; i < t.Elem().NumField(); i++ {
       
   195 		f := t.Elem().Field(i)
       
   196 		if tag := f.Tag.Get("protobuf"); tag != "" {
       
   197 			switch f.Type.Kind() {
       
   198 			case reflect.Bool, reflect.Int32, reflect.Int64, reflect.Uint32, reflect.Uint64, reflect.Float32, reflect.Float64, reflect.String:
       
   199 				md.L0.ParentFile = filedesc.SurrogateProto3
       
   200 			}
       
   201 			for _, s := range strings.Split(tag, ",") {
       
   202 				if s == "proto3" {
       
   203 					md.L0.ParentFile = filedesc.SurrogateProto3
       
   204 				}
       
   205 			}
       
   206 		}
       
   207 	}
       
   208 
       
   209 	// Obtain a list of oneof wrapper types.
       
   210 	var oneofWrappers []reflect.Type
       
   211 	for _, method := range []string{"XXX_OneofFuncs", "XXX_OneofWrappers"} {
       
   212 		if fn, ok := t.MethodByName(method); ok {
       
   213 			for _, v := range fn.Func.Call([]reflect.Value{reflect.Zero(fn.Type.In(0))}) {
       
   214 				if vs, ok := v.Interface().([]interface{}); ok {
       
   215 					for _, v := range vs {
       
   216 						oneofWrappers = append(oneofWrappers, reflect.TypeOf(v))
       
   217 					}
       
   218 				}
       
   219 			}
       
   220 		}
       
   221 	}
       
   222 
       
   223 	// Obtain a list of the extension ranges.
       
   224 	if fn, ok := t.MethodByName("ExtensionRangeArray"); ok {
       
   225 		vs := fn.Func.Call([]reflect.Value{reflect.Zero(fn.Type.In(0))})[0]
       
   226 		for i := 0; i < vs.Len(); i++ {
       
   227 			v := vs.Index(i)
       
   228 			md.L2.ExtensionRanges.List = append(md.L2.ExtensionRanges.List, [2]pref.FieldNumber{
       
   229 				pref.FieldNumber(v.FieldByName("Start").Int()),
       
   230 				pref.FieldNumber(v.FieldByName("End").Int() + 1),
       
   231 			})
       
   232 			md.L2.ExtensionRangeOptions = append(md.L2.ExtensionRangeOptions, nil)
       
   233 		}
       
   234 	}
       
   235 
       
   236 	// Derive the message fields by inspecting the struct fields.
       
   237 	for i := 0; i < t.Elem().NumField(); i++ {
       
   238 		f := t.Elem().Field(i)
       
   239 		if tag := f.Tag.Get("protobuf"); tag != "" {
       
   240 			tagKey := f.Tag.Get("protobuf_key")
       
   241 			tagVal := f.Tag.Get("protobuf_val")
       
   242 			aberrantAppendField(md, f.Type, tag, tagKey, tagVal)
       
   243 		}
       
   244 		if tag := f.Tag.Get("protobuf_oneof"); tag != "" {
       
   245 			n := len(md.L2.Oneofs.List)
       
   246 			md.L2.Oneofs.List = append(md.L2.Oneofs.List, filedesc.Oneof{})
       
   247 			od := &md.L2.Oneofs.List[n]
       
   248 			od.L0.FullName = md.FullName().Append(pref.Name(tag))
       
   249 			od.L0.ParentFile = md.L0.ParentFile
       
   250 			od.L0.Parent = md
       
   251 			od.L0.Index = n
       
   252 
       
   253 			for _, t := range oneofWrappers {
       
   254 				if t.Implements(f.Type) {
       
   255 					f := t.Elem().Field(0)
       
   256 					if tag := f.Tag.Get("protobuf"); tag != "" {
       
   257 						aberrantAppendField(md, f.Type, tag, "", "")
       
   258 						fd := &md.L2.Fields.List[len(md.L2.Fields.List)-1]
       
   259 						fd.L1.ContainingOneof = od
       
   260 						od.L1.Fields.List = append(od.L1.Fields.List, fd)
       
   261 					}
       
   262 				}
       
   263 			}
       
   264 		}
       
   265 	}
       
   266 
       
   267 	return md
       
   268 }
       
   269 
       
   270 func aberrantDeriveMessageName(t reflect.Type, name pref.FullName) pref.FullName {
       
   271 	if name.IsValid() {
       
   272 		return name
       
   273 	}
       
   274 	func() {
       
   275 		defer func() { recover() }() // swallow possible nil panics
       
   276 		if m, ok := reflect.Zero(t).Interface().(interface{ XXX_MessageName() string }); ok {
       
   277 			name = pref.FullName(m.XXX_MessageName())
       
   278 		}
       
   279 	}()
       
   280 	if name.IsValid() {
       
   281 		return name
       
   282 	}
       
   283 	if t.Kind() == reflect.Ptr {
       
   284 		t = t.Elem()
       
   285 	}
       
   286 	return AberrantDeriveFullName(t)
       
   287 }
       
   288 
       
   289 func aberrantAppendField(md *filedesc.Message, goType reflect.Type, tag, tagKey, tagVal string) {
       
   290 	t := goType
       
   291 	isOptional := t.Kind() == reflect.Ptr && t.Elem().Kind() != reflect.Struct
       
   292 	isRepeated := t.Kind() == reflect.Slice && t.Elem().Kind() != reflect.Uint8
       
   293 	if isOptional || isRepeated {
       
   294 		t = t.Elem()
       
   295 	}
       
   296 	fd := ptag.Unmarshal(tag, t, placeholderEnumValues{}).(*filedesc.Field)
       
   297 
       
   298 	// Append field descriptor to the message.
       
   299 	n := len(md.L2.Fields.List)
       
   300 	md.L2.Fields.List = append(md.L2.Fields.List, *fd)
       
   301 	fd = &md.L2.Fields.List[n]
       
   302 	fd.L0.FullName = md.FullName().Append(fd.Name())
       
   303 	fd.L0.ParentFile = md.L0.ParentFile
       
   304 	fd.L0.Parent = md
       
   305 	fd.L0.Index = n
       
   306 
       
   307 	if fd.L1.IsWeak || fd.L1.HasPacked {
       
   308 		fd.L1.Options = func() pref.ProtoMessage {
       
   309 			opts := descopts.Field.ProtoReflect().New()
       
   310 			if fd.L1.IsWeak {
       
   311 				opts.Set(opts.Descriptor().Fields().ByName("weak"), protoreflect.ValueOfBool(true))
       
   312 			}
       
   313 			if fd.L1.HasPacked {
       
   314 				opts.Set(opts.Descriptor().Fields().ByName("packed"), protoreflect.ValueOfBool(fd.L1.IsPacked))
       
   315 			}
       
   316 			return opts.Interface()
       
   317 		}
       
   318 	}
       
   319 
       
   320 	// Populate Enum and Message.
       
   321 	if fd.Enum() == nil && fd.Kind() == pref.EnumKind {
       
   322 		switch v := reflect.Zero(t).Interface().(type) {
       
   323 		case pref.Enum:
       
   324 			fd.L1.Enum = v.Descriptor()
       
   325 		default:
       
   326 			fd.L1.Enum = LegacyLoadEnumDesc(t)
       
   327 		}
       
   328 	}
       
   329 	if fd.Message() == nil && (fd.Kind() == pref.MessageKind || fd.Kind() == pref.GroupKind) {
       
   330 		switch v := reflect.Zero(t).Interface().(type) {
       
   331 		case pref.ProtoMessage:
       
   332 			fd.L1.Message = v.ProtoReflect().Descriptor()
       
   333 		case messageV1:
       
   334 			fd.L1.Message = LegacyLoadMessageDesc(t)
       
   335 		default:
       
   336 			if t.Kind() == reflect.Map {
       
   337 				n := len(md.L1.Messages.List)
       
   338 				md.L1.Messages.List = append(md.L1.Messages.List, filedesc.Message{L2: new(filedesc.MessageL2)})
       
   339 				md2 := &md.L1.Messages.List[n]
       
   340 				md2.L0.FullName = md.FullName().Append(pref.Name(strs.MapEntryName(string(fd.Name()))))
       
   341 				md2.L0.ParentFile = md.L0.ParentFile
       
   342 				md2.L0.Parent = md
       
   343 				md2.L0.Index = n
       
   344 
       
   345 				md2.L1.IsMapEntry = true
       
   346 				md2.L2.Options = func() pref.ProtoMessage {
       
   347 					opts := descopts.Message.ProtoReflect().New()
       
   348 					opts.Set(opts.Descriptor().Fields().ByName("map_entry"), protoreflect.ValueOfBool(true))
       
   349 					return opts.Interface()
       
   350 				}
       
   351 
       
   352 				aberrantAppendField(md2, t.Key(), tagKey, "", "")
       
   353 				aberrantAppendField(md2, t.Elem(), tagVal, "", "")
       
   354 
       
   355 				fd.L1.Message = md2
       
   356 				break
       
   357 			}
       
   358 			fd.L1.Message = aberrantLoadMessageDescReentrant(t, "")
       
   359 		}
       
   360 	}
       
   361 }
       
   362 
       
   363 type placeholderEnumValues struct {
       
   364 	protoreflect.EnumValueDescriptors
       
   365 }
       
   366 
       
   367 func (placeholderEnumValues) ByNumber(n pref.EnumNumber) pref.EnumValueDescriptor {
       
   368 	return filedesc.PlaceholderEnumValue(pref.FullName(fmt.Sprintf("UNKNOWN_%d", n)))
       
   369 }
       
   370 
       
   371 // legacyMarshaler is the proto.Marshaler interface superseded by protoiface.Methoder.
       
   372 type legacyMarshaler interface {
       
   373 	Marshal() ([]byte, error)
       
   374 }
       
   375 
       
   376 // legacyUnmarshaler is the proto.Unmarshaler interface superseded by protoiface.Methoder.
       
   377 type legacyUnmarshaler interface {
       
   378 	Unmarshal([]byte) error
       
   379 }
       
   380 
       
   381 // legacyMerger is the proto.Merger interface superseded by protoiface.Methoder.
       
   382 type legacyMerger interface {
       
   383 	Merge(protoiface.MessageV1)
       
   384 }
       
   385 
       
   386 var aberrantProtoMethods = &piface.Methods{
       
   387 	Marshal:   legacyMarshal,
       
   388 	Unmarshal: legacyUnmarshal,
       
   389 	Merge:     legacyMerge,
       
   390 
       
   391 	// We have no way to tell whether the type's Marshal method
       
   392 	// supports deterministic serialization or not, but this
       
   393 	// preserves the v1 implementation's behavior of always
       
   394 	// calling Marshal methods when present.
       
   395 	Flags: piface.SupportMarshalDeterministic,
       
   396 }
       
   397 
       
   398 func legacyMarshal(in piface.MarshalInput) (piface.MarshalOutput, error) {
       
   399 	v := in.Message.(unwrapper).protoUnwrap()
       
   400 	marshaler, ok := v.(legacyMarshaler)
       
   401 	if !ok {
       
   402 		return piface.MarshalOutput{}, errors.New("%T does not implement Marshal", v)
       
   403 	}
       
   404 	out, err := marshaler.Marshal()
       
   405 	if in.Buf != nil {
       
   406 		out = append(in.Buf, out...)
       
   407 	}
       
   408 	return piface.MarshalOutput{
       
   409 		Buf: out,
       
   410 	}, err
       
   411 }
       
   412 
       
   413 func legacyUnmarshal(in piface.UnmarshalInput) (piface.UnmarshalOutput, error) {
       
   414 	v := in.Message.(unwrapper).protoUnwrap()
       
   415 	unmarshaler, ok := v.(legacyUnmarshaler)
       
   416 	if !ok {
       
   417 		return piface.UnmarshalOutput{}, errors.New("%T does not implement Unmarshal", v)
       
   418 	}
       
   419 	return piface.UnmarshalOutput{}, unmarshaler.Unmarshal(in.Buf)
       
   420 }
       
   421 
       
   422 func legacyMerge(in piface.MergeInput) piface.MergeOutput {
       
   423 	// Check whether this supports the legacy merger.
       
   424 	dstv := in.Destination.(unwrapper).protoUnwrap()
       
   425 	merger, ok := dstv.(legacyMerger)
       
   426 	if ok {
       
   427 		merger.Merge(Export{}.ProtoMessageV1Of(in.Source))
       
   428 		return piface.MergeOutput{Flags: piface.MergeComplete}
       
   429 	}
       
   430 
       
   431 	// If legacy merger is unavailable, implement merge in terms of
       
   432 	// a marshal and unmarshal operation.
       
   433 	srcv := in.Source.(unwrapper).protoUnwrap()
       
   434 	marshaler, ok := srcv.(legacyMarshaler)
       
   435 	if !ok {
       
   436 		return piface.MergeOutput{}
       
   437 	}
       
   438 	dstv = in.Destination.(unwrapper).protoUnwrap()
       
   439 	unmarshaler, ok := dstv.(legacyUnmarshaler)
       
   440 	if !ok {
       
   441 		return piface.MergeOutput{}
       
   442 	}
       
   443 	if !in.Source.IsValid() {
       
   444 		// Legacy Marshal methods may not function on nil messages.
       
   445 		// Check for a typed nil source only after we confirm that
       
   446 		// legacy Marshal/Unmarshal methods are present, for
       
   447 		// consistency.
       
   448 		return piface.MergeOutput{Flags: piface.MergeComplete}
       
   449 	}
       
   450 	b, err := marshaler.Marshal()
       
   451 	if err != nil {
       
   452 		return piface.MergeOutput{}
       
   453 	}
       
   454 	err = unmarshaler.Unmarshal(b)
       
   455 	if err != nil {
       
   456 		return piface.MergeOutput{}
       
   457 	}
       
   458 	return piface.MergeOutput{Flags: piface.MergeComplete}
       
   459 }
       
   460 
       
   461 // aberrantMessageType implements MessageType for all types other than pointer-to-struct.
       
   462 type aberrantMessageType struct {
       
   463 	t reflect.Type
       
   464 }
       
   465 
       
   466 func (mt aberrantMessageType) New() pref.Message {
       
   467 	if mt.t.Kind() == reflect.Ptr {
       
   468 		return aberrantMessage{reflect.New(mt.t.Elem())}
       
   469 	}
       
   470 	return aberrantMessage{reflect.Zero(mt.t)}
       
   471 }
       
   472 func (mt aberrantMessageType) Zero() pref.Message {
       
   473 	return aberrantMessage{reflect.Zero(mt.t)}
       
   474 }
       
   475 func (mt aberrantMessageType) GoType() reflect.Type {
       
   476 	return mt.t
       
   477 }
       
   478 func (mt aberrantMessageType) Descriptor() pref.MessageDescriptor {
       
   479 	return LegacyLoadMessageDesc(mt.t)
       
   480 }
       
   481 
       
   482 // aberrantMessage implements Message for all types other than pointer-to-struct.
       
   483 //
       
   484 // When the underlying type implements legacyMarshaler or legacyUnmarshaler,
       
   485 // the aberrant Message can be marshaled or unmarshaled. Otherwise, there is
       
   486 // not much that can be done with values of this type.
       
   487 type aberrantMessage struct {
       
   488 	v reflect.Value
       
   489 }
       
   490 
       
   491 // Reset implements the v1 proto.Message.Reset method.
       
   492 func (m aberrantMessage) Reset() {
       
   493 	if mr, ok := m.v.Interface().(interface{ Reset() }); ok {
       
   494 		mr.Reset()
       
   495 		return
       
   496 	}
       
   497 	if m.v.Kind() == reflect.Ptr && !m.v.IsNil() {
       
   498 		m.v.Elem().Set(reflect.Zero(m.v.Type().Elem()))
       
   499 	}
       
   500 }
       
   501 
       
   502 func (m aberrantMessage) ProtoReflect() pref.Message {
       
   503 	return m
       
   504 }
       
   505 
       
   506 func (m aberrantMessage) Descriptor() pref.MessageDescriptor {
       
   507 	return LegacyLoadMessageDesc(m.v.Type())
       
   508 }
       
   509 func (m aberrantMessage) Type() pref.MessageType {
       
   510 	return aberrantMessageType{m.v.Type()}
       
   511 }
       
   512 func (m aberrantMessage) New() pref.Message {
       
   513 	if m.v.Type().Kind() == reflect.Ptr {
       
   514 		return aberrantMessage{reflect.New(m.v.Type().Elem())}
       
   515 	}
       
   516 	return aberrantMessage{reflect.Zero(m.v.Type())}
       
   517 }
       
   518 func (m aberrantMessage) Interface() pref.ProtoMessage {
       
   519 	return m
       
   520 }
       
   521 func (m aberrantMessage) Range(f func(pref.FieldDescriptor, pref.Value) bool) {
       
   522 	return
       
   523 }
       
   524 func (m aberrantMessage) Has(pref.FieldDescriptor) bool {
       
   525 	return false
       
   526 }
       
   527 func (m aberrantMessage) Clear(pref.FieldDescriptor) {
       
   528 	panic("invalid Message.Clear on " + string(m.Descriptor().FullName()))
       
   529 }
       
   530 func (m aberrantMessage) Get(fd pref.FieldDescriptor) pref.Value {
       
   531 	if fd.Default().IsValid() {
       
   532 		return fd.Default()
       
   533 	}
       
   534 	panic("invalid Message.Get on " + string(m.Descriptor().FullName()))
       
   535 }
       
   536 func (m aberrantMessage) Set(pref.FieldDescriptor, pref.Value) {
       
   537 	panic("invalid Message.Set on " + string(m.Descriptor().FullName()))
       
   538 }
       
   539 func (m aberrantMessage) Mutable(pref.FieldDescriptor) pref.Value {
       
   540 	panic("invalid Message.Mutable on " + string(m.Descriptor().FullName()))
       
   541 }
       
   542 func (m aberrantMessage) NewField(pref.FieldDescriptor) pref.Value {
       
   543 	panic("invalid Message.NewField on " + string(m.Descriptor().FullName()))
       
   544 }
       
   545 func (m aberrantMessage) WhichOneof(pref.OneofDescriptor) pref.FieldDescriptor {
       
   546 	panic("invalid Message.WhichOneof descriptor on " + string(m.Descriptor().FullName()))
       
   547 }
       
   548 func (m aberrantMessage) GetUnknown() pref.RawFields {
       
   549 	return nil
       
   550 }
       
   551 func (m aberrantMessage) SetUnknown(pref.RawFields) {
       
   552 	// SetUnknown discards its input on messages which don't support unknown field storage.
       
   553 }
       
   554 func (m aberrantMessage) IsValid() bool {
       
   555 	if m.v.Kind() == reflect.Ptr {
       
   556 		return !m.v.IsNil()
       
   557 	}
       
   558 	return false
       
   559 }
       
   560 func (m aberrantMessage) ProtoMethods() *piface.Methods {
       
   561 	return aberrantProtoMethods
       
   562 }
       
   563 func (m aberrantMessage) protoUnwrap() interface{} {
       
   564 	return m.v.Interface()
       
   565 }