Use mattermost v5 module (#1192)

1 files changed, 260 insertions, 511 deletions

diff --git a/vendor/github.com/golang/protobuf/proto/extensions.go b/vendor/github.com/golang/protobuf/proto/extensions.go
index fa88add3..42fc120c 100644
--- a/vendor/github.com/golang/protobuf/proto/extensions.go
+++ b/vendor/github.com/golang/protobuf/proto/extensions.go
@@ -1,607 +1,356 @@
-// Go support for Protocol Buffers - Google's data interchange format
-//
-// Copyright 2010 The Go Authors.  All rights reserved.
-// https://github.com/golang/protobuf
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//     * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+// Copyright 2010 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 proto
 
-/*
- * Types and routines for supporting protocol buffer extensions.
- */
-
 import (
 	"errors"
 	"fmt"
-	"io"
 	"reflect"
-	"strconv"
-	"sync"
-)
-
-// ErrMissingExtension is the error returned by GetExtension if the named extension is not in the message.
-var ErrMissingExtension = errors.New("proto: missing extension")
-
-// ExtensionRange represents a range of message extensions for a protocol buffer.
-// Used in code generated by the protocol compiler.
-type ExtensionRange struct {
-	Start, End int32 // both inclusive
-}
-
-// extendableProto is an interface implemented by any protocol buffer generated by the current
-// proto compiler that may be extended.
-type extendableProto interface {
-	Message
-	ExtensionRangeArray() []ExtensionRange
-	extensionsWrite() map[int32]Extension
-	extensionsRead() (map[int32]Extension, sync.Locker)
-}
-
-// extendableProtoV1 is an interface implemented by a protocol buffer generated by the previous
-// version of the proto compiler that may be extended.
-type extendableProtoV1 interface {
-	Message
-	ExtensionRangeArray() []ExtensionRange
-	ExtensionMap() map[int32]Extension
-}
 
-// extensionAdapter is a wrapper around extendableProtoV1 that implements extendableProto.
-type extensionAdapter struct {
-	extendableProtoV1
-}
+	"google.golang.org/protobuf/encoding/protowire"
+	"google.golang.org/protobuf/proto"
+	"google.golang.org/protobuf/reflect/protoreflect"
+	"google.golang.org/protobuf/reflect/protoregistry"
+	"google.golang.org/protobuf/runtime/protoiface"
+	"google.golang.org/protobuf/runtime/protoimpl"
+)
 
-func (e extensionAdapter) extensionsWrite() map[int32]Extension {
-	return e.ExtensionMap()
-}
+type (
+	// ExtensionDesc represents an extension descriptor and
+	// is used to interact with an extension field in a message.
+	//
+	// Variables of this type are generated in code by protoc-gen-go.
+	ExtensionDesc = protoimpl.ExtensionInfo
 
-func (e extensionAdapter) extensionsRead() (map[int32]Extension, sync.Locker) {
-	return e.ExtensionMap(), notLocker{}
-}
+	// ExtensionRange represents a range of message extensions.
+	// Used in code generated by protoc-gen-go.
+	ExtensionRange = protoiface.ExtensionRangeV1
 
-// notLocker is a sync.Locker whose Lock and Unlock methods are nops.
-type notLocker struct{}
+	// Deprecated: Do not use; this is an internal type.
+	Extension = protoimpl.ExtensionFieldV1
 
-func (n notLocker) Lock()   {}
-func (n notLocker) Unlock() {}
+	// Deprecated: Do not use; this is an internal type.
+	XXX_InternalExtensions = protoimpl.ExtensionFields
+)
 
-// extendable returns the extendableProto interface for the given generated proto message.
-// If the proto message has the old extension format, it returns a wrapper that implements
-// the extendableProto interface.
-func extendable(p interface{}) (extendableProto, error) {
-	switch p := p.(type) {
-	case extendableProto:
-		if isNilPtr(p) {
-			return nil, fmt.Errorf("proto: nil %T is not extendable", p)
-		}
-		return p, nil
-	case extendableProtoV1:
-		if isNilPtr(p) {
-			return nil, fmt.Errorf("proto: nil %T is not extendable", p)
-		}
-		return extensionAdapter{p}, nil
-	}
-	// Don't allocate a specific error containing %T:
-	// this is the hot path for Clone and MarshalText.
-	return nil, errNotExtendable
-}
+// ErrMissingExtension reports whether the extension was not present.
+var ErrMissingExtension = errors.New("proto: missing extension")
 
 var errNotExtendable = errors.New("proto: not an extendable proto.Message")
 
-func isNilPtr(x interface{}) bool {
-	v := reflect.ValueOf(x)
-	return v.Kind() == reflect.Ptr && v.IsNil()
-}
-
-// XXX_InternalExtensions is an internal representation of proto extensions.
-//
-// Each generated message struct type embeds an anonymous XXX_InternalExtensions field,
-// thus gaining the unexported 'extensions' method, which can be called only from the proto package.
-//
-// The methods of XXX_InternalExtensions are not concurrency safe in general,
-// but calls to logically read-only methods such as has and get may be executed concurrently.
-type XXX_InternalExtensions struct {
-	// The struct must be indirect so that if a user inadvertently copies a
-	// generated message and its embedded XXX_InternalExtensions, they
-	// avoid the mayhem of a copied mutex.
-	//
-	// The mutex serializes all logically read-only operations to p.extensionMap.
-	// It is up to the client to ensure that write operations to p.extensionMap are
-	// mutually exclusive with other accesses.
-	p *struct {
-		mu           sync.Mutex
-		extensionMap map[int32]Extension
+// HasExtension reports whether the extension field is present in m
+// either as an explicitly populated field or as an unknown field.
+func HasExtension(m Message, xt *ExtensionDesc) (has bool) {
+	mr := MessageReflect(m)
+	if mr == nil || !mr.IsValid() {
+		return false
 	}
-}
 
-// extensionsWrite returns the extension map, creating it on first use.
-func (e *XXX_InternalExtensions) extensionsWrite() map[int32]Extension {
-	if e.p == nil {
-		e.p = new(struct {
-			mu           sync.Mutex
-			extensionMap map[int32]Extension
+	// Check whether any populated known field matches the field number.
+	xtd := xt.TypeDescriptor()
+	if isValidExtension(mr.Descriptor(), xtd) {
+		has = mr.Has(xtd)
+	} else {
+		mr.Range(func(fd protoreflect.FieldDescriptor, _ protoreflect.Value) bool {
+			has = int32(fd.Number()) == xt.Field
+			return !has
 		})
-		e.p.extensionMap = make(map[int32]Extension)
 	}
-	return e.p.extensionMap
-}
 
-// extensionsRead returns the extensions map for read-only use.  It may be nil.
-// The caller must hold the returned mutex's lock when accessing Elements within the map.
-func (e *XXX_InternalExtensions) extensionsRead() (map[int32]Extension, sync.Locker) {
-	if e.p == nil {
-		return nil, nil
+	// Check whether any unknown field matches the field number.
+	for b := mr.GetUnknown(); !has && len(b) > 0; {
+		num, _, n := protowire.ConsumeField(b)
+		has = int32(num) == xt.Field
+		b = b[n:]
 	}
-	return e.p.extensionMap, &e.p.mu
-}
-
-// ExtensionDesc represents an extension specification.
-// Used in generated code from the protocol compiler.
-type ExtensionDesc struct {
-	ExtendedType  Message     // nil pointer to the type that is being extended
-	ExtensionType interface{} // nil pointer to the extension type
-	Field         int32       // field number
-	Name          string      // fully-qualified name of extension, for text formatting
-	Tag           string      // protobuf tag style
-	Filename      string      // name of the file in which the extension is defined
-}
-
-func (ed *ExtensionDesc) repeated() bool {
-	t := reflect.TypeOf(ed.ExtensionType)
-	return t.Kind() == reflect.Slice && t.Elem().Kind() != reflect.Uint8
-}
-
-// Extension represents an extension in a message.
-type Extension struct {
-	// When an extension is stored in a message using SetExtension
-	// only desc and value are set. When the message is marshaled
-	// enc will be set to the encoded form of the message.
-	//
-	// When a message is unmarshaled and contains extensions, each
-	// extension will have only enc set. When such an extension is
-	// accessed using GetExtension (or GetExtensions) desc and value
-	// will be set.
-	desc *ExtensionDesc
-
-	// value is a concrete value for the extension field. Let the type of
-	// desc.ExtensionType be the "API type" and the type of Extension.value
-	// be the "storage type". The API type and storage type are the same except:
-	//	* For scalars (except []byte), the API type uses *T,
-	//	while the storage type uses T.
-	//	* For repeated fields, the API type uses []T, while the storage type
-	//	uses *[]T.
-	//
-	// The reason for the divergence is so that the storage type more naturally
-	// matches what is expected of when retrieving the values through the
-	// protobuf reflection APIs.
-	//
-	// The value may only be populated if desc is also populated.
-	value interface{}
-
-	// enc is the raw bytes for the extension field.
-	enc []byte
+	return has
 }
 
-// SetRawExtension is for testing only.
-func SetRawExtension(base Message, id int32, b []byte) {
-	epb, err := extendable(base)
-	if err != nil {
+// ClearExtension removes the extension field from m
+// either as an explicitly populated field or as an unknown field.
+func ClearExtension(m Message, xt *ExtensionDesc) {
+	mr := MessageReflect(m)
+	if mr == nil || !mr.IsValid() {
 		return
 	}
-	extmap := epb.extensionsWrite()
-	extmap[id] = Extension{enc: b}
-}
 
-// isExtensionField returns true iff the given field number is in an extension range.
-func isExtensionField(pb extendableProto, field int32) bool {
-	for _, er := range pb.ExtensionRangeArray() {
-		if er.Start <= field && field <= er.End {
+	xtd := xt.TypeDescriptor()
+	if isValidExtension(mr.Descriptor(), xtd) {
+		mr.Clear(xtd)
+	} else {
+		mr.Range(func(fd protoreflect.FieldDescriptor, _ protoreflect.Value) bool {
+			if int32(fd.Number()) == xt.Field {
+				mr.Clear(fd)
+				return false
+			}
 			return true
-		}
-	}
-	return false
-}
-
-// checkExtensionTypes checks that the given extension is valid for pb.
-func checkExtensionTypes(pb extendableProto, extension *ExtensionDesc) error {
-	var pbi interface{} = pb
-	// Check the extended type.
-	if ea, ok := pbi.(extensionAdapter); ok {
-		pbi = ea.extendableProtoV1
-	}
-	if a, b := reflect.TypeOf(pbi), reflect.TypeOf(extension.ExtendedType); a != b {
-		return fmt.Errorf("proto: bad extended type; %v does not extend %v", b, a)
-	}
-	// Check the range.
-	if !isExtensionField(pb, extension.Field) {
-		return errors.New("proto: bad extension number; not in declared ranges")
-	}
-	return nil
-}
-
-// extPropKey is sufficient to uniquely identify an extension.
-type extPropKey struct {
-	base  reflect.Type
-	field int32
-}
-
-var extProp = struct {
-	sync.RWMutex
-	m map[extPropKey]*Properties
-}{
-	m: make(map[extPropKey]*Properties),
-}
-
-func extensionProperties(ed *ExtensionDesc) *Properties {
-	key := extPropKey{base: reflect.TypeOf(ed.ExtendedType), field: ed.Field}
-
-	extProp.RLock()
-	if prop, ok := extProp.m[key]; ok {
-		extProp.RUnlock()
-		return prop
-	}
-	extProp.RUnlock()
-
-	extProp.Lock()
-	defer extProp.Unlock()
-	// Check again.
-	if prop, ok := extProp.m[key]; ok {
-		return prop
-	}
-
-	prop := new(Properties)
-	prop.Init(reflect.TypeOf(ed.ExtensionType), "unknown_name", ed.Tag, nil)
-	extProp.m[key] = prop
-	return prop
-}
-
-// HasExtension returns whether the given extension is present in pb.
-func HasExtension(pb Message, extension *ExtensionDesc) bool {
-	// TODO: Check types, field numbers, etc.?
-	epb, err := extendable(pb)
-	if err != nil {
-		return false
-	}
-	extmap, mu := epb.extensionsRead()
-	if extmap == nil {
-		return false
+		})
 	}
-	mu.Lock()
-	_, ok := extmap[extension.Field]
-	mu.Unlock()
-	return ok
+	clearUnknown(mr, fieldNum(xt.Field))
 }
 
-// ClearExtension removes the given extension from pb.
-func ClearExtension(pb Message, extension *ExtensionDesc) {
-	epb, err := extendable(pb)
-	if err != nil {
+// ClearAllExtensions clears all extensions from m.
+// This includes populated fields and unknown fields in the extension range.
+func ClearAllExtensions(m Message) {
+	mr := MessageReflect(m)
+	if mr == nil || !mr.IsValid() {
 		return
 	}
-	// TODO: Check types, field numbers, etc.?
-	extmap := epb.extensionsWrite()
-	delete(extmap, extension.Field)
+
+	mr.Range(func(fd protoreflect.FieldDescriptor, _ protoreflect.Value) bool {
+		if fd.IsExtension() {
+			mr.Clear(fd)
+		}
+		return true
+	})
+	clearUnknown(mr, mr.Descriptor().ExtensionRanges())
 }
 
-// GetExtension retrieves a proto2 extended field from pb.
+// GetExtension retrieves a proto2 extended field from m.
 //
 // If the descriptor is type complete (i.e., ExtensionDesc.ExtensionType is non-nil),
 // then GetExtension parses the encoded field and returns a Go value of the specified type.
 // If the field is not present, then the default value is returned (if one is specified),
 // otherwise ErrMissingExtension is reported.
 //
-// If the descriptor is not type complete (i.e., ExtensionDesc.ExtensionType is nil),
-// then GetExtension returns the raw encoded bytes of the field extension.
-func GetExtension(pb Message, extension *ExtensionDesc) (interface{}, error) {
-	epb, err := extendable(pb)
-	if err != nil {
-		return nil, err
-	}
-
-	if extension.ExtendedType != nil {
-		// can only check type if this is a complete descriptor
-		if err := checkExtensionTypes(epb, extension); err != nil {
-			return nil, err
+// If the descriptor is type incomplete (i.e., ExtensionDesc.ExtensionType is nil),
+// then GetExtension returns the raw encoded bytes for the extension field.
+func GetExtension(m Message, xt *ExtensionDesc) (interface{}, error) {
+	mr := MessageReflect(m)
+	if mr == nil || !mr.IsValid() || mr.Descriptor().ExtensionRanges().Len() == 0 {
+		return nil, errNotExtendable
+	}
+
+	// Retrieve the unknown fields for this extension field.
+	var bo protoreflect.RawFields
+	for bi := mr.GetUnknown(); len(bi) > 0; {
+		num, _, n := protowire.ConsumeField(bi)
+		if int32(num) == xt.Field {
+			bo = append(bo, bi[:n]...)
 		}
+		bi = bi[n:]
 	}
 
-	emap, mu := epb.extensionsRead()
-	if emap == nil {
-		return defaultExtensionValue(extension)
-	}
-	mu.Lock()
-	defer mu.Unlock()
-	e, ok := emap[extension.Field]
-	if !ok {
-		// defaultExtensionValue returns the default value or
-		// ErrMissingExtension if there is no default.
-		return defaultExtensionValue(extension)
-	}
-
-	if e.value != nil {
-		// Already decoded. Check the descriptor, though.
-		if e.desc != extension {
-			// This shouldn't happen. If it does, it means that
-			// GetExtension was called twice with two different
-			// descriptors with the same field number.
-			return nil, errors.New("proto: descriptor conflict")
-		}
-		return extensionAsLegacyType(e.value), nil
+	// For type incomplete descriptors, only retrieve the unknown fields.
+	if xt.ExtensionType == nil {
+		return []byte(bo), nil
 	}
 
-	if extension.ExtensionType == nil {
-		// incomplete descriptor
-		return e.enc, nil
+	// If the extension field only exists as unknown fields, unmarshal it.
+	// This is rarely done since proto.Unmarshal eagerly unmarshals extensions.
+	xtd := xt.TypeDescriptor()
+	if !isValidExtension(mr.Descriptor(), xtd) {
+		return nil, fmt.Errorf("proto: bad extended type; %T does not extend %T", xt.ExtendedType, m)
 	}
-
-	v, err := decodeExtension(e.enc, extension)
-	if err != nil {
-		return nil, err
+	if !mr.Has(xtd) && len(bo) > 0 {
+		m2 := mr.New()
+		if err := (proto.UnmarshalOptions{
+			Resolver: extensionResolver{xt},
+		}.Unmarshal(bo, m2.Interface())); err != nil {
+			return nil, err
+		}
+		if m2.Has(xtd) {
+			mr.Set(xtd, m2.Get(xtd))
+			clearUnknown(mr, fieldNum(xt.Field))
+		}
 	}
 
-	// Remember the decoded version and drop the encoded version.
-	// That way it is safe to mutate what we return.
-	e.value = extensionAsStorageType(v)
-	e.desc = extension
-	e.enc = nil
-	emap[extension.Field] = e
-	return extensionAsLegacyType(e.value), nil
-}
-
-// defaultExtensionValue returns the default value for extension.
-// If no default for an extension is defined ErrMissingExtension is returned.
-func defaultExtensionValue(extension *ExtensionDesc) (interface{}, error) {
-	if extension.ExtensionType == nil {
-		// incomplete descriptor, so no default
+	// Check whether the message has the extension field set or a default.
+	var pv protoreflect.Value
+	switch {
+	case mr.Has(xtd):
+		pv = mr.Get(xtd)
+	case xtd.HasDefault():
+		pv = xtd.Default()
+	default:
 		return nil, ErrMissingExtension
 	}
 
-	t := reflect.TypeOf(extension.ExtensionType)
-	props := extensionProperties(extension)
-
-	sf, _, err := fieldDefault(t, props)
-	if err != nil {
-		return nil, err
-	}
-
-	if sf == nil || sf.value == nil {
-		// There is no default value.
-		return nil, ErrMissingExtension
+	v := xt.InterfaceOf(pv)
+	rv := reflect.ValueOf(v)
+	if isScalarKind(rv.Kind()) {
+		rv2 := reflect.New(rv.Type())
+		rv2.Elem().Set(rv)
+		v = rv2.Interface()
 	}
+	return v, nil
+}
 
-	if t.Kind() != reflect.Ptr {
-		// We do not need to return a Ptr, we can directly return sf.value.
-		return sf.value, nil
-	}
+// extensionResolver is a custom extension resolver that stores a single
+// extension type that takes precedence over the global registry.
+type extensionResolver struct{ xt protoreflect.ExtensionType }
 
-	// We need to return an interface{} that is a pointer to sf.value.
-	value := reflect.New(t).Elem()
-	value.Set(reflect.New(value.Type().Elem()))
-	if sf.kind == reflect.Int32 {
-		// We may have an int32 or an enum, but the underlying data is int32.
-		// Since we can't set an int32 into a non int32 reflect.value directly
-		// set it as a int32.
-		value.Elem().SetInt(int64(sf.value.(int32)))
-	} else {
-		value.Elem().Set(reflect.ValueOf(sf.value))
+func (r extensionResolver) FindExtensionByName(field protoreflect.FullName) (protoreflect.ExtensionType, error) {
+	if xtd := r.xt.TypeDescriptor(); xtd.FullName() == field {
+		return r.xt, nil
 	}
-	return value.Interface(), nil
+	return protoregistry.GlobalTypes.FindExtensionByName(field)
 }
 
-// decodeExtension decodes an extension encoded in b.
-func decodeExtension(b []byte, extension *ExtensionDesc) (interface{}, error) {
-	t := reflect.TypeOf(extension.ExtensionType)
-	unmarshal := typeUnmarshaler(t, extension.Tag)
-
-	// t is a pointer to a struct, pointer to basic type or a slice.
-	// Allocate space to store the pointer/slice.
-	value := reflect.New(t).Elem()
-
-	var err error
-	for {
-		x, n := decodeVarint(b)
-		if n == 0 {
-			return nil, io.ErrUnexpectedEOF
-		}
-		b = b[n:]
-		wire := int(x) & 7
-
-		b, err = unmarshal(b, valToPointer(value.Addr()), wire)
-		if err != nil {
-			return nil, err
-		}
-
-		if len(b) == 0 {
-			break
-		}
+func (r extensionResolver) FindExtensionByNumber(message protoreflect.FullName, field protoreflect.FieldNumber) (protoreflect.ExtensionType, error) {
+	if xtd := r.xt.TypeDescriptor(); xtd.ContainingMessage().FullName() == message && xtd.Number() == field {
+		return r.xt, nil
 	}
-	return value.Interface(), nil
+	return protoregistry.GlobalTypes.FindExtensionByNumber(message, field)
 }
 
-// GetExtensions returns a slice of the extensions present in pb that are also listed in es.
-// The returned slice has the same length as es; missing extensions will appear as nil elements.
-func GetExtensions(pb Message, es []*ExtensionDesc) (extensions []interface{}, err error) {
-	epb, err := extendable(pb)
-	if err != nil {
-		return nil, err
+// GetExtensions returns a list of the extensions values present in m,
+// corresponding with the provided list of extension descriptors, xts.
+// If an extension is missing in m, the corresponding value is nil.
+func GetExtensions(m Message, xts []*ExtensionDesc) ([]interface{}, error) {
+	mr := MessageReflect(m)
+	if mr == nil || !mr.IsValid() {
+		return nil, errNotExtendable
 	}
-	extensions = make([]interface{}, len(es))
-	for i, e := range es {
-		extensions[i], err = GetExtension(epb, e)
-		if err == ErrMissingExtension {
-			err = nil
-		}
+
+	vs := make([]interface{}, len(xts))
+	for i, xt := range xts {
+		v, err := GetExtension(m, xt)
 		if err != nil {
-			return
+			if err == ErrMissingExtension {
+				continue
+			}
+			return vs, err
 		}
+		vs[i] = v
 	}
-	return
+	return vs, nil
 }
 
-// ExtensionDescs returns a new slice containing pb's extension descriptors, in undefined order.
-// For non-registered extensions, ExtensionDescs returns an incomplete descriptor containing
-// just the Field field, which defines the extension's field number.
-func ExtensionDescs(pb Message) ([]*ExtensionDesc, error) {
-	epb, err := extendable(pb)
-	if err != nil {
-		return nil, err
+// SetExtension sets an extension field in m to the provided value.
+func SetExtension(m Message, xt *ExtensionDesc, v interface{}) error {
+	mr := MessageReflect(m)
+	if mr == nil || !mr.IsValid() || mr.Descriptor().ExtensionRanges().Len() == 0 {
+		return errNotExtendable
 	}
-	registeredExtensions := RegisteredExtensions(pb)
 
-	emap, mu := epb.extensionsRead()
-	if emap == nil {
-		return nil, nil
+	rv := reflect.ValueOf(v)
+	if reflect.TypeOf(v) != reflect.TypeOf(xt.ExtensionType) {
+		return fmt.Errorf("proto: bad extension value type. got: %T, want: %T", v, xt.ExtensionType)
 	}
-	mu.Lock()
-	defer mu.Unlock()
-	extensions := make([]*ExtensionDesc, 0, len(emap))
-	for extid, e := range emap {
-		desc := e.desc
-		if desc == nil {
-			desc = registeredExtensions[extid]
-			if desc == nil {
-				desc = &ExtensionDesc{Field: extid}
-			}
+	if rv.Kind() == reflect.Ptr {
+		if rv.IsNil() {
+			return fmt.Errorf("proto: SetExtension called with nil value of type %T", v)
+		}
+		if isScalarKind(rv.Elem().Kind()) {
+			v = rv.Elem().Interface()
 		}
-
-		extensions = append(extensions, desc)
 	}
-	return extensions, nil
-}
 
-// SetExtension sets the specified extension of pb to the specified value.
-func SetExtension(pb Message, extension *ExtensionDesc, value interface{}) error {
-	epb, err := extendable(pb)
-	if err != nil {
-		return err
-	}
-	if err := checkExtensionTypes(epb, extension); err != nil {
-		return err
-	}
-	typ := reflect.TypeOf(extension.ExtensionType)
-	if typ != reflect.TypeOf(value) {
-		return fmt.Errorf("proto: bad extension value type. got: %T, want: %T", value, extension.ExtensionType)
+	xtd := xt.TypeDescriptor()
+	if !isValidExtension(mr.Descriptor(), xtd) {
+		return fmt.Errorf("proto: bad extended type; %T does not extend %T", xt.ExtendedType, m)
 	}
-	// nil extension values need to be caught early, because the
-	// encoder can't distinguish an ErrNil due to a nil extension
-	// from an ErrNil due to a missing field. Extensions are
-	// always optional, so the encoder would just swallow the error
-	// and drop all the extensions from the encoded message.
-	if reflect.ValueOf(value).IsNil() {
-		return fmt.Errorf("proto: SetExtension called with nil value of type %T", value)
-	}
-
-	extmap := epb.extensionsWrite()
-	extmap[extension.Field] = Extension{desc: extension, value: extensionAsStorageType(value)}
+	mr.Set(xtd, xt.ValueOf(v))
+	clearUnknown(mr, fieldNum(xt.Field))
 	return nil
 }
 
-// ClearAllExtensions clears all extensions from pb.
-func ClearAllExtensions(pb Message) {
-	epb, err := extendable(pb)
-	if err != nil {
+// SetRawExtension inserts b into the unknown fields of m.
+//
+// Deprecated: Use Message.ProtoReflect.SetUnknown instead.
+func SetRawExtension(m Message, fnum int32, b []byte) {
+	mr := MessageReflect(m)
+	if mr == nil || !mr.IsValid() {
 		return
 	}
-	m := epb.extensionsWrite()
-	for k := range m {
-		delete(m, k)
+
+	// Verify that the raw field is valid.
+	for b0 := b; len(b0) > 0; {
+		num, _, n := protowire.ConsumeField(b0)
+		if int32(num) != fnum {
+			panic(fmt.Sprintf("mismatching field number: got %d, want %d", num, fnum))
+		}
+		b0 = b0[n:]
 	}
-}
 
-// A global registry of extensions.
-// The generated code will register the generated descriptors by calling RegisterExtension.
+	ClearExtension(m, &ExtensionDesc{Field: fnum})
+	mr.SetUnknown(append(mr.GetUnknown(), b...))
+}
 
-var extensionMaps = make(map[reflect.Type]map[int32]*ExtensionDesc)
+// ExtensionDescs returns a list of extension descriptors found in m,
+// containing descriptors for both populated extension fields in m and
+// also unknown fields of m that are in the extension range.
+// For the later case, an type incomplete descriptor is provided where only
+// the ExtensionDesc.Field field is populated.
+// The order of the extension descriptors is undefined.
+func ExtensionDescs(m Message) ([]*ExtensionDesc, error) {
+	mr := MessageReflect(m)
+	if mr == nil || !mr.IsValid() || mr.Descriptor().ExtensionRanges().Len() == 0 {
+		return nil, errNotExtendable
+	}
 
-// RegisterExtension is called from the generated code.
-func RegisterExtension(desc *ExtensionDesc) {
-	st := reflect.TypeOf(desc.ExtendedType).Elem()
-	m := extensionMaps[st]
-	if m == nil {
-		m = make(map[int32]*ExtensionDesc)
-		extensionMaps[st] = m
+	// Collect a set of known extension descriptors.
+	extDescs := make(map[protoreflect.FieldNumber]*ExtensionDesc)
+	mr.Range(func(fd protoreflect.FieldDescriptor, v protoreflect.Value) bool {
+		if fd.IsExtension() {
+			xt := fd.(protoreflect.ExtensionTypeDescriptor)
+			if xd, ok := xt.Type().(*ExtensionDesc); ok {
+				extDescs[fd.Number()] = xd
+			}
+		}
+		return true
+	})
+
+	// Collect a set of unknown extension descriptors.
+	extRanges := mr.Descriptor().ExtensionRanges()
+	for b := mr.GetUnknown(); len(b) > 0; {
+		num, _, n := protowire.ConsumeField(b)
+		if extRanges.Has(num) && extDescs[num] == nil {
+			extDescs[num] = nil
+		}
+		b = b[n:]
 	}
-	if _, ok := m[desc.Field]; ok {
-		panic("proto: duplicate extension registered: " + st.String() + " " + strconv.Itoa(int(desc.Field)))
+
+	// Transpose the set of descriptors into a list.
+	var xts []*ExtensionDesc
+	for num, xt := range extDescs {
+		if xt == nil {
+			xt = &ExtensionDesc{Field: int32(num)}
+		}
+		xts = append(xts, xt)
 	}
-	m[desc.Field] = desc
+	return xts, nil
 }
 
-// RegisteredExtensions returns a map of the registered extensions of a
-// protocol buffer struct, indexed by the extension number.
-// The argument pb should be a nil pointer to the struct type.
-func RegisteredExtensions(pb Message) map[int32]*ExtensionDesc {
-	return extensionMaps[reflect.TypeOf(pb).Elem()]
+// isValidExtension reports whether xtd is a valid extension descriptor for md.
+func isValidExtension(md protoreflect.MessageDescriptor, xtd protoreflect.ExtensionTypeDescriptor) bool {
+	return xtd.ContainingMessage() == md && md.ExtensionRanges().Has(xtd.Number())
 }
 
-// extensionAsLegacyType converts an value in the storage type as the API type.
-// See Extension.value.
-func extensionAsLegacyType(v interface{}) interface{} {
-	switch rv := reflect.ValueOf(v); rv.Kind() {
+// isScalarKind reports whether k is a protobuf scalar kind (except bytes).
+// This function exists for historical reasons since the representation of
+// scalars differs between v1 and v2, where v1 uses *T and v2 uses T.
+func isScalarKind(k reflect.Kind) bool {
+	switch k {
 	case reflect.Bool, reflect.Int32, reflect.Int64, reflect.Uint32, reflect.Uint64, reflect.Float32, reflect.Float64, reflect.String:
-		// Represent primitive types as a pointer to the value.
-		rv2 := reflect.New(rv.Type())
-		rv2.Elem().Set(rv)
-		v = rv2.Interface()
-	case reflect.Ptr:
-		// Represent slice types as the value itself.
-		switch rv.Type().Elem().Kind() {
-		case reflect.Slice:
-			if rv.IsNil() {
-				v = reflect.Zero(rv.Type().Elem()).Interface()
-			} else {
-				v = rv.Elem().Interface()
-			}
-		}
+		return true
+	default:
+		return false
 	}
-	return v
 }
 
-// extensionAsStorageType converts an value in the API type as the storage type.
-// See Extension.value.
-func extensionAsStorageType(v interface{}) interface{} {
-	switch rv := reflect.ValueOf(v); rv.Kind() {
-	case reflect.Ptr:
-		// Represent slice types as the value itself.
-		switch rv.Type().Elem().Kind() {
-		case reflect.Bool, reflect.Int32, reflect.Int64, reflect.Uint32, reflect.Uint64, reflect.Float32, reflect.Float64, reflect.String:
-			if rv.IsNil() {
-				v = reflect.Zero(rv.Type().Elem()).Interface()
-			} else {
-				v = rv.Elem().Interface()
-			}
-		}
-	case reflect.Slice:
-		// Represent slice types as a pointer to the value.
-		if rv.Type().Elem().Kind() != reflect.Uint8 {
-			rv2 := reflect.New(rv.Type())
-			rv2.Elem().Set(rv)
-			v = rv2.Interface()
+// clearUnknown removes unknown fields from m where remover.Has reports true.
+func clearUnknown(m protoreflect.Message, remover interface {
+	Has(protoreflect.FieldNumber) bool
+}) {
+	var bo protoreflect.RawFields
+	for bi := m.GetUnknown(); len(bi) > 0; {
+		num, _, n := protowire.ConsumeField(bi)
+		if !remover.Has(num) {
+			bo = append(bo, bi[:n]...)
 		}
+		bi = bi[n:]
 	}
-	return v
+	if bi := m.GetUnknown(); len(bi) != len(bo) {
+		m.SetUnknown(bo)
+	}
+}
+
+type fieldNum protoreflect.FieldNumber
+
+func (n1 fieldNum) Has(n2 protoreflect.FieldNumber) bool {
+	return protoreflect.FieldNumber(n1) == n2
 }