Girish Gowdra | 390f12f | 2021-07-01 15:53:49 -0700 | [diff] [blame^] | 1 | // Copyright 2019 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 protodesc |
| 6 | |
| 7 | import ( |
| 8 | "google.golang.org/protobuf/internal/encoding/defval" |
| 9 | "google.golang.org/protobuf/internal/errors" |
| 10 | "google.golang.org/protobuf/internal/filedesc" |
| 11 | "google.golang.org/protobuf/reflect/protoreflect" |
| 12 | "google.golang.org/protobuf/reflect/protoregistry" |
| 13 | |
| 14 | "google.golang.org/protobuf/types/descriptorpb" |
| 15 | ) |
| 16 | |
| 17 | // resolver is a wrapper around a local registry of declarations within the file |
| 18 | // and the remote resolver. The remote resolver is restricted to only return |
| 19 | // descriptors that have been imported. |
| 20 | type resolver struct { |
| 21 | local descsByName |
| 22 | remote Resolver |
| 23 | imports importSet |
| 24 | |
| 25 | allowUnresolvable bool |
| 26 | } |
| 27 | |
| 28 | func (r *resolver) resolveMessageDependencies(ms []filedesc.Message, mds []*descriptorpb.DescriptorProto) (err error) { |
| 29 | for i, md := range mds { |
| 30 | m := &ms[i] |
| 31 | for j, fd := range md.GetField() { |
| 32 | f := &m.L2.Fields.List[j] |
| 33 | if f.L1.Cardinality == protoreflect.Required { |
| 34 | m.L2.RequiredNumbers.List = append(m.L2.RequiredNumbers.List, f.L1.Number) |
| 35 | } |
| 36 | if fd.OneofIndex != nil { |
| 37 | k := int(fd.GetOneofIndex()) |
| 38 | if !(0 <= k && k < len(md.GetOneofDecl())) { |
| 39 | return errors.New("message field %q has an invalid oneof index: %d", f.FullName(), k) |
| 40 | } |
| 41 | o := &m.L2.Oneofs.List[k] |
| 42 | f.L1.ContainingOneof = o |
| 43 | o.L1.Fields.List = append(o.L1.Fields.List, f) |
| 44 | } |
| 45 | |
| 46 | 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 { |
| 47 | return errors.New("message field %q cannot resolve type: %v", f.FullName(), err) |
| 48 | } |
| 49 | if fd.DefaultValue != nil { |
| 50 | v, ev, err := unmarshalDefault(fd.GetDefaultValue(), f, r.allowUnresolvable) |
| 51 | if err != nil { |
| 52 | return errors.New("message field %q has invalid default: %v", f.FullName(), err) |
| 53 | } |
| 54 | f.L1.Default = filedesc.DefaultValue(v, ev) |
| 55 | } |
| 56 | } |
| 57 | |
| 58 | if err := r.resolveMessageDependencies(m.L1.Messages.List, md.GetNestedType()); err != nil { |
| 59 | return err |
| 60 | } |
| 61 | if err := r.resolveExtensionDependencies(m.L1.Extensions.List, md.GetExtension()); err != nil { |
| 62 | return err |
| 63 | } |
| 64 | } |
| 65 | return nil |
| 66 | } |
| 67 | |
| 68 | func (r *resolver) resolveExtensionDependencies(xs []filedesc.Extension, xds []*descriptorpb.FieldDescriptorProto) (err error) { |
| 69 | for i, xd := range xds { |
| 70 | x := &xs[i] |
| 71 | if x.L1.Extendee, err = r.findMessageDescriptor(x.Parent().FullName(), partialName(xd.GetExtendee()), false); err != nil { |
| 72 | return errors.New("extension field %q cannot resolve extendee: %v", x.FullName(), err) |
| 73 | } |
| 74 | if x.L1.Kind, x.L2.Enum, x.L2.Message, err = r.findTarget(x.Kind(), x.Parent().FullName(), partialName(xd.GetTypeName()), false); err != nil { |
| 75 | return errors.New("extension field %q cannot resolve type: %v", x.FullName(), err) |
| 76 | } |
| 77 | if xd.DefaultValue != nil { |
| 78 | v, ev, err := unmarshalDefault(xd.GetDefaultValue(), x, r.allowUnresolvable) |
| 79 | if err != nil { |
| 80 | return errors.New("extension field %q has invalid default: %v", x.FullName(), err) |
| 81 | } |
| 82 | x.L2.Default = filedesc.DefaultValue(v, ev) |
| 83 | } |
| 84 | } |
| 85 | return nil |
| 86 | } |
| 87 | |
| 88 | func (r *resolver) resolveServiceDependencies(ss []filedesc.Service, sds []*descriptorpb.ServiceDescriptorProto) (err error) { |
| 89 | for i, sd := range sds { |
| 90 | s := &ss[i] |
| 91 | for j, md := range sd.GetMethod() { |
| 92 | m := &s.L2.Methods.List[j] |
| 93 | m.L1.Input, err = r.findMessageDescriptor(m.Parent().FullName(), partialName(md.GetInputType()), false) |
| 94 | if err != nil { |
| 95 | return errors.New("service method %q cannot resolve input: %v", m.FullName(), err) |
| 96 | } |
| 97 | m.L1.Output, err = r.findMessageDescriptor(s.FullName(), partialName(md.GetOutputType()), false) |
| 98 | if err != nil { |
| 99 | return errors.New("service method %q cannot resolve output: %v", m.FullName(), err) |
| 100 | } |
| 101 | } |
| 102 | } |
| 103 | return nil |
| 104 | } |
| 105 | |
| 106 | // findTarget finds an enum or message descriptor if k is an enum, message, |
| 107 | // group, or unknown. If unknown, and the name could be resolved, the kind |
| 108 | // returned kind is set based on the type of the resolved descriptor. |
| 109 | func (r *resolver) findTarget(k protoreflect.Kind, scope protoreflect.FullName, ref partialName, isWeak bool) (protoreflect.Kind, protoreflect.EnumDescriptor, protoreflect.MessageDescriptor, error) { |
| 110 | switch k { |
| 111 | case protoreflect.EnumKind: |
| 112 | ed, err := r.findEnumDescriptor(scope, ref, isWeak) |
| 113 | if err != nil { |
| 114 | return 0, nil, nil, err |
| 115 | } |
| 116 | return k, ed, nil, nil |
| 117 | case protoreflect.MessageKind, protoreflect.GroupKind: |
| 118 | md, err := r.findMessageDescriptor(scope, ref, isWeak) |
| 119 | if err != nil { |
| 120 | return 0, nil, nil, err |
| 121 | } |
| 122 | return k, nil, md, nil |
| 123 | case 0: |
| 124 | // Handle unspecified kinds (possible with parsers that operate |
| 125 | // on a per-file basis without knowledge of dependencies). |
| 126 | d, err := r.findDescriptor(scope, ref) |
| 127 | if err == protoregistry.NotFound && (r.allowUnresolvable || isWeak) { |
| 128 | return k, filedesc.PlaceholderEnum(ref.FullName()), filedesc.PlaceholderMessage(ref.FullName()), nil |
| 129 | } else if err == protoregistry.NotFound { |
| 130 | return 0, nil, nil, errors.New("%q not found", ref.FullName()) |
| 131 | } else if err != nil { |
| 132 | return 0, nil, nil, err |
| 133 | } |
| 134 | switch d := d.(type) { |
| 135 | case protoreflect.EnumDescriptor: |
| 136 | return protoreflect.EnumKind, d, nil, nil |
| 137 | case protoreflect.MessageDescriptor: |
| 138 | return protoreflect.MessageKind, nil, d, nil |
| 139 | default: |
| 140 | return 0, nil, nil, errors.New("unknown kind") |
| 141 | } |
| 142 | default: |
| 143 | if ref != "" { |
| 144 | return 0, nil, nil, errors.New("target name cannot be specified for %v", k) |
| 145 | } |
| 146 | if !k.IsValid() { |
| 147 | return 0, nil, nil, errors.New("invalid kind: %d", k) |
| 148 | } |
| 149 | return k, nil, nil, nil |
| 150 | } |
| 151 | } |
| 152 | |
| 153 | // findDescriptor finds the descriptor by name, |
| 154 | // which may be a relative name within some scope. |
| 155 | // |
| 156 | // Suppose the scope was "fizz.buzz" and the reference was "Foo.Bar", |
| 157 | // then the following full names are searched: |
| 158 | // * fizz.buzz.Foo.Bar |
| 159 | // * fizz.Foo.Bar |
| 160 | // * Foo.Bar |
| 161 | func (r *resolver) findDescriptor(scope protoreflect.FullName, ref partialName) (protoreflect.Descriptor, error) { |
| 162 | if !ref.IsValid() { |
| 163 | return nil, errors.New("invalid name reference: %q", ref) |
| 164 | } |
| 165 | if ref.IsFull() { |
| 166 | scope, ref = "", ref[1:] |
| 167 | } |
| 168 | var foundButNotImported protoreflect.Descriptor |
| 169 | for { |
| 170 | // Derive the full name to search. |
| 171 | s := protoreflect.FullName(ref) |
| 172 | if scope != "" { |
| 173 | s = scope + "." + s |
| 174 | } |
| 175 | |
| 176 | // Check the current file for the descriptor. |
| 177 | if d, ok := r.local[s]; ok { |
| 178 | return d, nil |
| 179 | } |
| 180 | |
| 181 | // Check the remote registry for the descriptor. |
| 182 | d, err := r.remote.FindDescriptorByName(s) |
| 183 | if err == nil { |
| 184 | // Only allow descriptors covered by one of the imports. |
| 185 | if r.imports[d.ParentFile().Path()] { |
| 186 | return d, nil |
| 187 | } |
| 188 | foundButNotImported = d |
| 189 | } else if err != protoregistry.NotFound { |
| 190 | return nil, errors.Wrap(err, "%q", s) |
| 191 | } |
| 192 | |
| 193 | // Continue on at a higher level of scoping. |
| 194 | if scope == "" { |
| 195 | if d := foundButNotImported; d != nil { |
| 196 | return nil, errors.New("resolved %q, but %q is not imported", d.FullName(), d.ParentFile().Path()) |
| 197 | } |
| 198 | return nil, protoregistry.NotFound |
| 199 | } |
| 200 | scope = scope.Parent() |
| 201 | } |
| 202 | } |
| 203 | |
| 204 | func (r *resolver) findEnumDescriptor(scope protoreflect.FullName, ref partialName, isWeak bool) (protoreflect.EnumDescriptor, error) { |
| 205 | d, err := r.findDescriptor(scope, ref) |
| 206 | if err == protoregistry.NotFound && (r.allowUnresolvable || isWeak) { |
| 207 | return filedesc.PlaceholderEnum(ref.FullName()), nil |
| 208 | } else if err == protoregistry.NotFound { |
| 209 | return nil, errors.New("%q not found", ref.FullName()) |
| 210 | } else if err != nil { |
| 211 | return nil, err |
| 212 | } |
| 213 | ed, ok := d.(protoreflect.EnumDescriptor) |
| 214 | if !ok { |
| 215 | return nil, errors.New("resolved %q, but it is not an enum", d.FullName()) |
| 216 | } |
| 217 | return ed, nil |
| 218 | } |
| 219 | |
| 220 | func (r *resolver) findMessageDescriptor(scope protoreflect.FullName, ref partialName, isWeak bool) (protoreflect.MessageDescriptor, error) { |
| 221 | d, err := r.findDescriptor(scope, ref) |
| 222 | if err == protoregistry.NotFound && (r.allowUnresolvable || isWeak) { |
| 223 | return filedesc.PlaceholderMessage(ref.FullName()), nil |
| 224 | } else if err == protoregistry.NotFound { |
| 225 | return nil, errors.New("%q not found", ref.FullName()) |
| 226 | } else if err != nil { |
| 227 | return nil, err |
| 228 | } |
| 229 | md, ok := d.(protoreflect.MessageDescriptor) |
| 230 | if !ok { |
| 231 | return nil, errors.New("resolved %q, but it is not an message", d.FullName()) |
| 232 | } |
| 233 | return md, nil |
| 234 | } |
| 235 | |
| 236 | // partialName is the partial name. A leading dot means that the name is full, |
| 237 | // otherwise the name is relative to some current scope. |
| 238 | // See google.protobuf.FieldDescriptorProto.type_name. |
| 239 | type partialName string |
| 240 | |
| 241 | func (s partialName) IsFull() bool { |
| 242 | return len(s) > 0 && s[0] == '.' |
| 243 | } |
| 244 | |
| 245 | func (s partialName) IsValid() bool { |
| 246 | if s.IsFull() { |
| 247 | return protoreflect.FullName(s[1:]).IsValid() |
| 248 | } |
| 249 | return protoreflect.FullName(s).IsValid() |
| 250 | } |
| 251 | |
| 252 | const unknownPrefix = "*." |
| 253 | |
| 254 | // FullName converts the partial name to a full name on a best-effort basis. |
| 255 | // If relative, it creates an invalid full name, using a "*." prefix |
| 256 | // to indicate that the start of the full name is unknown. |
| 257 | func (s partialName) FullName() protoreflect.FullName { |
| 258 | if s.IsFull() { |
| 259 | return protoreflect.FullName(s[1:]) |
| 260 | } |
| 261 | return protoreflect.FullName(unknownPrefix + s) |
| 262 | } |
| 263 | |
| 264 | func unmarshalDefault(s string, fd protoreflect.FieldDescriptor, allowUnresolvable bool) (protoreflect.Value, protoreflect.EnumValueDescriptor, error) { |
| 265 | var evs protoreflect.EnumValueDescriptors |
| 266 | if fd.Enum() != nil { |
| 267 | evs = fd.Enum().Values() |
| 268 | } |
| 269 | v, ev, err := defval.Unmarshal(s, fd.Kind(), evs, defval.Descriptor) |
| 270 | if err != nil && allowUnresolvable && evs != nil && protoreflect.Name(s).IsValid() { |
| 271 | v = protoreflect.ValueOfEnum(0) |
| 272 | if evs.Len() > 0 { |
| 273 | v = protoreflect.ValueOfEnum(evs.Get(0).Number()) |
| 274 | } |
| 275 | ev = filedesc.PlaceholderEnumValue(fd.Enum().FullName().Parent().Append(protoreflect.Name(s))) |
| 276 | } else if err != nil { |
| 277 | return v, ev, err |
| 278 | } |
| 279 | if fd.Syntax() == protoreflect.Proto3 { |
| 280 | return v, ev, errors.New("cannot be specified under proto3 semantics") |
| 281 | } |
| 282 | if fd.Kind() == protoreflect.MessageKind || fd.Kind() == protoreflect.GroupKind || fd.Cardinality() == protoreflect.Repeated { |
| 283 | return v, ev, errors.New("cannot be specified on composite types") |
| 284 | } |
| 285 | return v, ev, nil |
| 286 | } |