protobuf-go/internal/filedesc/placeholder.go
Joe Tsai 851185dae3 internal/impl: support aberrant enums and messages
Aberrant messages are hand-crafted messages that happen to work because
they use the same struct tags that generated code emits.
This happens to work in v1, but is unspecified behavior and entirely outside
the compatibility promise.

Support for this was added early on in the history of the v2 implementation,
but entirely untested. It was removed in CL/182360 to reduce the
technical debt of the legacy implementation. Unfortunately, sufficient number
of targets do rely on this aberrant support, so it is being added back.

The logic being added is essentially the same thing as the previous logic,
but ported to use internal/filedesc instead of the now deleted
internal/prototype package.

Change-Id: Ib5cab3e90480825b9615db358044ce05a14b05bd
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/184517
Reviewed-by: Damien Neil <dneil@google.com>
2019-07-01 21:18:15 +00:00

106 lines
6.4 KiB
Go

// 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 filedesc
import (
"google.golang.org/protobuf/internal/descopts"
"google.golang.org/protobuf/internal/pragma"
pref "google.golang.org/protobuf/reflect/protoreflect"
)
var (
emptyNames = new(Names)
emptyEnumRanges = new(EnumRanges)
emptyFieldRanges = new(FieldRanges)
emptyFieldNumbers = new(FieldNumbers)
emptyFiles = new(FileImports)
emptyMessages = new(Messages)
emptyFields = new(Fields)
emptyOneofs = new(Oneofs)
emptyEnums = new(Enums)
emptyEnumValues = new(EnumValues)
emptyExtensions = new(Extensions)
emptyServices = new(Services)
)
// PlaceholderFile is a placeholder, representing only the file path.
type PlaceholderFile string
func (f PlaceholderFile) ParentFile() pref.FileDescriptor { return f }
func (f PlaceholderFile) Parent() pref.Descriptor { return nil }
func (f PlaceholderFile) Index() int { return 0 }
func (f PlaceholderFile) Syntax() pref.Syntax { return 0 }
func (f PlaceholderFile) Name() pref.Name { return "" }
func (f PlaceholderFile) FullName() pref.FullName { return "" }
func (f PlaceholderFile) IsPlaceholder() bool { return true }
func (f PlaceholderFile) Options() pref.ProtoMessage { return descopts.File }
func (f PlaceholderFile) Path() string { return string(f) }
func (f PlaceholderFile) Package() pref.FullName { return "" }
func (f PlaceholderFile) Imports() pref.FileImports { return emptyFiles }
func (f PlaceholderFile) Messages() pref.MessageDescriptors { return emptyMessages }
func (f PlaceholderFile) Enums() pref.EnumDescriptors { return emptyEnums }
func (f PlaceholderFile) Extensions() pref.ExtensionDescriptors { return emptyExtensions }
func (f PlaceholderFile) Services() pref.ServiceDescriptors { return emptyServices }
func (f PlaceholderFile) ProtoType(pref.FileDescriptor) { return }
func (f PlaceholderFile) ProtoInternal(pragma.DoNotImplement) { return }
// PlaceholderEnum is a placeholder, representing only the full name.
type PlaceholderEnum pref.FullName
func (e PlaceholderEnum) ParentFile() pref.FileDescriptor { return nil }
func (e PlaceholderEnum) Parent() pref.Descriptor { return nil }
func (e PlaceholderEnum) Index() int { return 0 }
func (e PlaceholderEnum) Syntax() pref.Syntax { return 0 }
func (e PlaceholderEnum) Name() pref.Name { return pref.FullName(e).Name() }
func (e PlaceholderEnum) FullName() pref.FullName { return pref.FullName(e) }
func (e PlaceholderEnum) IsPlaceholder() bool { return true }
func (e PlaceholderEnum) Options() pref.ProtoMessage { return descopts.Enum }
func (e PlaceholderEnum) Values() pref.EnumValueDescriptors { return emptyEnumValues }
func (e PlaceholderEnum) ReservedNames() pref.Names { return emptyNames }
func (e PlaceholderEnum) ReservedRanges() pref.EnumRanges { return emptyEnumRanges }
func (e PlaceholderEnum) ProtoType(pref.EnumDescriptor) { return }
func (e PlaceholderEnum) ProtoInternal(pragma.DoNotImplement) { return }
// PlaceholderEnumValue is a placeholder, representing only the full name.
type PlaceholderEnumValue pref.FullName
func (e PlaceholderEnumValue) ParentFile() pref.FileDescriptor { return nil }
func (e PlaceholderEnumValue) Parent() pref.Descriptor { return nil }
func (e PlaceholderEnumValue) Index() int { return 0 }
func (e PlaceholderEnumValue) Syntax() pref.Syntax { return 0 }
func (e PlaceholderEnumValue) Name() pref.Name { return pref.FullName(e).Name() }
func (e PlaceholderEnumValue) FullName() pref.FullName { return pref.FullName(e) }
func (e PlaceholderEnumValue) IsPlaceholder() bool { return true }
func (e PlaceholderEnumValue) Options() pref.ProtoMessage { return descopts.EnumValue }
func (e PlaceholderEnumValue) Number() pref.EnumNumber { return 0 }
func (e PlaceholderEnumValue) ProtoType(pref.EnumValueDescriptor) { return }
func (e PlaceholderEnumValue) ProtoInternal(pragma.DoNotImplement) { return }
// PlaceholderMessage is a placeholder, representing only the full name.
type PlaceholderMessage pref.FullName
func (m PlaceholderMessage) ParentFile() pref.FileDescriptor { return nil }
func (m PlaceholderMessage) Parent() pref.Descriptor { return nil }
func (m PlaceholderMessage) Index() int { return 0 }
func (m PlaceholderMessage) Syntax() pref.Syntax { return 0 }
func (m PlaceholderMessage) Name() pref.Name { return pref.FullName(m).Name() }
func (m PlaceholderMessage) FullName() pref.FullName { return pref.FullName(m) }
func (m PlaceholderMessage) IsPlaceholder() bool { return true }
func (m PlaceholderMessage) Options() pref.ProtoMessage { return descopts.Message }
func (m PlaceholderMessage) IsMapEntry() bool { return false }
func (m PlaceholderMessage) Fields() pref.FieldDescriptors { return emptyFields }
func (m PlaceholderMessage) Oneofs() pref.OneofDescriptors { return emptyOneofs }
func (m PlaceholderMessage) ReservedNames() pref.Names { return emptyNames }
func (m PlaceholderMessage) ReservedRanges() pref.FieldRanges { return emptyFieldRanges }
func (m PlaceholderMessage) RequiredNumbers() pref.FieldNumbers { return emptyFieldNumbers }
func (m PlaceholderMessage) ExtensionRanges() pref.FieldRanges { return emptyFieldRanges }
func (m PlaceholderMessage) ExtensionRangeOptions(int) pref.ProtoMessage { panic("index out of range") }
func (m PlaceholderMessage) Messages() pref.MessageDescriptors { return emptyMessages }
func (m PlaceholderMessage) Enums() pref.EnumDescriptors { return emptyEnums }
func (m PlaceholderMessage) Extensions() pref.ExtensionDescriptors { return emptyExtensions }
func (m PlaceholderMessage) ProtoType(pref.MessageDescriptor) { return }
func (m PlaceholderMessage) ProtoInternal(pragma.DoNotImplement) { return }