Implement support in protoc-gen-go for generating messages and enums
that satisfy the v2 protobuf reflection interfaces. Specifically, the following
are added:
* top-level variable representing the file descriptor
* ProtoReflect method on enums (to implement protoV2.Enum)
* ProtoReflect method on messages (to implement protoV2.Message)
The following are not supported yet:
* resolving transitive dependencies for file imports
* Extension descriptors
* Service descriptors
The implementation approach creates a single array for all the message and enum
declarations and references sections of that array to complete dependencies.
Since protobuf declarations can form a graph (a message may depend on itself),
it is difficult to construct a graph as a single literal. One way is to use
placeholder descriptors, but that is not efficient as it requires encoding
the full name of each dependent enum and message and then later resolving it;
thus, both expanding the binary size and also increasing initialization cost.
Instead, we add a prototype.{Enum,Message}.Reference method to obtain a
descriptor reference for the purposes for satisfying dependencies.
As such, nested declarations and dependencies are populated in an init function.
Other changes to support the implementation:
* Added a protoimpl package to expose the MessageType type and also the
MessageTypeOf and EnumTypeOf helper functions.
* Added a protogen.File.GoIdent field to provide a suggested variable name
for the file descriptor.
* Added prototype.{Enum,Message}.Reference that provides a descriptor reference
for the purposes for satisfying cyclic dependencies.
* Added protoreflect.{Syntax,Cardinality,Kind}.GoString to obtain a Go source
identifier that represents the given constant.
Change-Id: I9455764882dee6ad10f251901e7d419091e8bf1d
Reviewed-on: https://go-review.googlesource.com/c/150074
Reviewed-by: Damien Neil <dneil@google.com>
Also replace the ident function with the handy GoImportPath.Ident method.
Change-Id: Ie4e820556fb83e659ab7e7af98f27fc24cdcd760
Reviewed-on: https://go-review.googlesource.com/c/152177
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
The marshaler, unmarshaler, and sizer functions are unused ever since
the underlying implementation was switched to be table-driven.
Change the function to only return the wrapper structs.
This change:
* enables generated protos to drop dependencies on certain proto types
* reduces the size of generated protos
* simplifies the implementation of oneofs in protoc-gen-go
Updates #708
Change-Id: I845c9009bc0236d1b51d34b014dc3e184303c0f2
Reviewed-on: https://go-review.googlesource.com/c/151357
Reviewed-by: Damien Neil <dneil@google.com>
This is a straight translation of the v1 API gRPC "plugin" to protogen.
Add a protoc-gen-go-grpc command. The preferred way to generate gRPC
services is to invoke both plugins separately:
protoc --go_out=. --go-grpc_out=. foo.proto
When invoked in this fashion, the generators will produce separate
foo.pb.go and foo_grpc.pb.go files.
Change-Id: Ie180385dab3da7063db96f7c2f9de3abbd749f63
Reviewed-on: https://go-review.googlesource.com/137037
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
