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// Copyright 2019 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 protodesc
import (
"google.golang.org/protobuf/internal/encoding/defval"
"google.golang.org/protobuf/internal/errors"
"google.golang.org/protobuf/internal/filedesc"
"google.golang.org/protobuf/reflect/protoreflect"
"google.golang.org/protobuf/reflect/protoregistry"
"google.golang.org/protobuf/types/descriptorpb"
)
// resolver is a wrapper around a local registry of declarations within the file
// and the remote resolver. The remote resolver is restricted to only return
// descriptors that have been imported.
type resolver struct {
local descsByName
remote Resolver
imports importSet
allowUnresolvable bool
}
func (r *resolver) resolveMessageDependencies(ms []filedesc.Message, mds []*descriptorpb.DescriptorProto) (err error) {
for i, md := range mds {
m := &ms[i]
for j, fd := range md.GetField() {
f := &m.L2.Fields.List[j]
if f.L1.Cardinality == protoreflect.Required {
m.L2.RequiredNumbers.List = append(m.L2.RequiredNumbers.List, f.L1.Number)
}
if fd.OneofIndex != nil {
k := int(fd.GetOneofIndex())
if !(0 <= k && k < len(md.GetOneofDecl())) {
return errors.New("message field %q has an invalid oneof index: %d", f.FullName(), k)
}
o := &m.L2.Oneofs.List[k]
f.L1.ContainingOneof = o
o.L1.Fields.List = append(o.L1.Fields.List, f)
}
if f.L1.Kind, f.L1.Enum, f.L1.Message, err = r.findTarget(f.Kind(), f.Parent().FullName(), partialName(fd.GetTypeName()), f.IsWeak()); err != nil {
return errors.New("message field %q cannot resolve type: %v", f.FullName(), err)
}
if f.L1.Kind == protoreflect.GroupKind && (f.IsMap() || f.IsMapEntry()) {
// A map field might inherit delimited encoding from a file-wide default feature.
// But maps never actually use delimited encoding. (At least for now...)
f.L1.Kind = protoreflect.MessageKind
}
if fd.DefaultValue != nil {
v, ev, err := unmarshalDefault(fd.GetDefaultValue(), f, r.allowUnresolvable)
if err != nil {
return errors.New("message field %q has invalid default: %v", f.FullName(), err)
}
f.L1.Default = filedesc.DefaultValue(v, ev)
}
}
if err := r.resolveMessageDependencies(m.L1.Messages.List, md.GetNestedType()); err != nil {
return err
}
if err := r.resolveExtensionDependencies(m.L1.Extensions.List, md.GetExtension()); err != nil {
return err
}
}
return nil
}
func (r *resolver) resolveExtensionDependencies(xs []filedesc.Extension, xds []*descriptorpb.FieldDescriptorProto) (err error) {
for i, xd := range xds {
x := &xs[i]
if x.L1.Extendee, err = r.findMessageDescriptor(x.Parent().FullName(), partialName(xd.GetExtendee()), false); err != nil {
return errors.New("extension field %q cannot resolve extendee: %v", x.FullName(), err)
}
if x.L1.Kind, x.L2.Enum, x.L2.Message, err = r.findTarget(x.Kind(), x.Parent().FullName(), partialName(xd.GetTypeName()), false); err != nil {
return errors.New("extension field %q cannot resolve type: %v", x.FullName(), err)
}
if xd.DefaultValue != nil {
v, ev, err := unmarshalDefault(xd.GetDefaultValue(), x, r.allowUnresolvable)
if err != nil {
return errors.New("extension field %q has invalid default: %v", x.FullName(), err)
}
x.L2.Default = filedesc.DefaultValue(v, ev)
}
}
return nil
}
func (r *resolver) resolveServiceDependencies(ss []filedesc.Service, sds []*descriptorpb.ServiceDescriptorProto) (err error) {
for i, sd := range sds {
s := &ss[i]
for j, md := range sd.GetMethod() {
m := &s.L2.Methods.List[j]
m.L1.Input, err = r.findMessageDescriptor(m.Parent().FullName(), partialName(md.GetInputType()), false)
if err != nil {
return errors.New("service method %q cannot resolve input: %v", m.FullName(), err)
}
m.L1.Output, err = r.findMessageDescriptor(s.FullName(), partialName(md.GetOutputType()), false)
if err != nil {
return errors.New("service method %q cannot resolve output: %v", m.FullName(), err)
}
}
}
return nil
}
// findTarget finds an enum or message descriptor if k is an enum, message,
// group, or unknown. If unknown, and the name could be resolved, the kind
// returned kind is set based on the type of the resolved descriptor.
func (r *resolver) findTarget(k protoreflect.Kind, scope protoreflect.FullName, ref partialName, isWeak bool) (protoreflect.Kind, protoreflect.EnumDescriptor, protoreflect.MessageDescriptor, error) {
switch k {
case protoreflect.EnumKind:
ed, err := r.findEnumDescriptor(scope, ref, isWeak)
if err != nil {
return 0, nil, nil, err
}
return k, ed, nil, nil
case protoreflect.MessageKind, protoreflect.GroupKind:
md, err := r.findMessageDescriptor(scope, ref, isWeak)
if err != nil {
return 0, nil, nil, err
}
return k, nil, md, nil
case 0:
// Handle unspecified kinds (possible with parsers that operate
// on a per-file basis without knowledge of dependencies).
d, err := r.findDescriptor(scope, ref)
if err == protoregistry.NotFound && (r.allowUnresolvable || isWeak) {
return k, filedesc.PlaceholderEnum(ref.FullName()), filedesc.PlaceholderMessage(ref.FullName()), nil
} else if err == protoregistry.NotFound {
return 0, nil, nil, errors.New("%q not found", ref.FullName())
} else if err != nil {
return 0, nil, nil, err
}
switch d := d.(type) {
case protoreflect.EnumDescriptor:
return protoreflect.EnumKind, d, nil, nil
case protoreflect.MessageDescriptor:
return protoreflect.MessageKind, nil, d, nil
default:
return 0, nil, nil, errors.New("unknown kind")
}
default:
if ref != "" {
return 0, nil, nil, errors.New("target name cannot be specified for %v", k)
}
if !k.IsValid() {
return 0, nil, nil, errors.New("invalid kind: %d", k)
}
return k, nil, nil, nil
}
}
// findDescriptor finds the descriptor by name,
// which may be a relative name within some scope.
//
// Suppose the scope was "fizz.buzz" and the reference was "Foo.Bar",
// then the following full names are searched:
// - fizz.buzz.Foo.Bar
// - fizz.Foo.Bar
// - Foo.Bar
func (r *resolver) findDescriptor(scope protoreflect.FullName, ref partialName) (protoreflect.Descriptor, error) {
if !ref.IsValid() {
return nil, errors.New("invalid name reference: %q", ref)
}
if ref.IsFull() {
scope, ref = "", ref[1:]
}
var foundButNotImported protoreflect.Descriptor
for {
// Derive the full name to search.
s := protoreflect.FullName(ref)
if scope != "" {
s = scope + "." + s
}
// Check the current file for the descriptor.
if d, ok := r.local[s]; ok {
return d, nil
}
// Check the remote registry for the descriptor.
d, err := r.remote.FindDescriptorByName(s)
if err == nil {
// Only allow descriptors covered by one of the imports.
if r.imports[d.ParentFile().Path()] {
return d, nil
}
foundButNotImported = d
} else if err != protoregistry.NotFound {
return nil, errors.Wrap(err, "%q", s)
}
// Continue on at a higher level of scoping.
if scope == "" {
if d := foundButNotImported; d != nil {
return nil, errors.New("resolved %q, but %q is not imported", d.FullName(), d.ParentFile().Path())
}
return nil, protoregistry.NotFound
}
scope = scope.Parent()
}
}
func (r *resolver) findEnumDescriptor(scope protoreflect.FullName, ref partialName, isWeak bool) (protoreflect.EnumDescriptor, error) {
d, err := r.findDescriptor(scope, ref)
if err == protoregistry.NotFound && (r.allowUnresolvable || isWeak) {
return filedesc.PlaceholderEnum(ref.FullName()), nil
} else if err == protoregistry.NotFound {
return nil, errors.New("%q not found", ref.FullName())
} else if err != nil {
return nil, err
}
ed, ok := d.(protoreflect.EnumDescriptor)
if !ok {
return nil, errors.New("resolved %q, but it is not an enum", d.FullName())
}
return ed, nil
}
func (r *resolver) findMessageDescriptor(scope protoreflect.FullName, ref partialName, isWeak bool) (protoreflect.MessageDescriptor, error) {
d, err := r.findDescriptor(scope, ref)
if err == protoregistry.NotFound && (r.allowUnresolvable || isWeak) {
return filedesc.PlaceholderMessage(ref.FullName()), nil
} else if err == protoregistry.NotFound {
return nil, errors.New("%q not found", ref.FullName())
} else if err != nil {
return nil, err
}
md, ok := d.(protoreflect.MessageDescriptor)
if !ok {
return nil, errors.New("resolved %q, but it is not an message", d.FullName())
}
return md, nil
}
// partialName is the partial name. A leading dot means that the name is full,
// otherwise the name is relative to some current scope.
// See google.protobuf.FieldDescriptorProto.type_name.
type partialName string
func (s partialName) IsFull() bool {
return len(s) > 0 && s[0] == '.'
}
func (s partialName) IsValid() bool {
if s.IsFull() {
return protoreflect.FullName(s[1:]).IsValid()
}
return protoreflect.FullName(s).IsValid()
}
const unknownPrefix = "*."
// FullName converts the partial name to a full name on a best-effort basis.
// If relative, it creates an invalid full name, using a "*." prefix
// to indicate that the start of the full name is unknown.
func (s partialName) FullName() protoreflect.FullName {
if s.IsFull() {
return protoreflect.FullName(s[1:])
}
return protoreflect.FullName(unknownPrefix + s)
}
func unmarshalDefault(s string, fd protoreflect.FieldDescriptor, allowUnresolvable bool) (protoreflect.Value, protoreflect.EnumValueDescriptor, error) {
var evs protoreflect.EnumValueDescriptors
if fd.Enum() != nil {
evs = fd.Enum().Values()
}
v, ev, err := defval.Unmarshal(s, fd.Kind(), evs, defval.Descriptor)
if err != nil && allowUnresolvable && evs != nil && protoreflect.Name(s).IsValid() {
v = protoreflect.ValueOfEnum(0)
if evs.Len() > 0 {
v = protoreflect.ValueOfEnum(evs.Get(0).Number())
}
ev = filedesc.PlaceholderEnumValue(fd.Enum().FullName().Parent().Append(protoreflect.Name(s)))
} else if err != nil {
return v, ev, err
}
if !fd.HasPresence() {
return v, ev, errors.New("cannot be specified with implicit field presence")
}
if fd.Kind() == protoreflect.MessageKind || fd.Kind() == protoreflect.GroupKind || fd.Cardinality() == protoreflect.Repeated {
return v, ev, errors.New("cannot be specified on composite types")
}
return v, ev, nil
}