cmd/protoc-gen-go: generate for v2-only dependencies

This removes yet another set of dependencies of v2 on v1.
The only remaining dependency are in the _test.go files,
primarily for proto.Equal.

Changes made:
* cmd/protoc-gen-go no longer generates any functionality that depends
on the v1 package, and instead only depends on v2.
* internal/fileinit.FileBuilder.MessageOutputTypes is switched from
protoreflect.MessageType to protoimpl.MessageType since the
implementation must be fully inialized before registration occurs.
* The test for internal/legacy/file_test.go is switched to a legacy_test
package to avoid a cyclic dependency.
This requires Load{Enum,Message,File}Desc to be exported.

Change-Id: I43e2fe64cff4eea204258ce11e791aca5eb6e569
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/169298
Reviewed-by: Damien Neil <dneil@google.com>
69 files changed
tree: 48e9329c2351b5716e4dc96c3a7dafb80d9df005
  1. cmd/
  2. encoding/
  3. internal/
  4. proto/
  5. protogen/
  6. reflect/
  7. runtime/
  8. types/
  9. .gitignore
  10. .travis.yml
  11. AUTHORS
  12. CONTRIBUTING.md
  13. CONTRIBUTORS
  14. go.mod
  15. go.sum
  16. integration_test.go
  17. LICENSE
  18. PATENTS
  19. README.md
  20. regenerate.bash
  21. test.bash
README.md

Next Generation Go Protocol Buffers

WARNING: This repository is in active development. There are no guarantees about API stability. Breaking changes will occur until a stable release is made and announced.

This repository is for the development of the next major Go implementation of protocol buffers. This library makes breaking API changes relative to the existing Go protobuf library. Of particular note, this API aims to make protobuf reflection a first-class feature of the API and implements the protobuf ecosystem in terms of reflection.

Design Documents

List of relevant design documents:

Contributing

We appreciate community contributions. See CONTRIBUTING.md.

Reporting Issues

Issues regarding the new API can be filed at github.com/golang/protobuf. Please use a APIv2: prefix in the title to make it clear that the issue is regarding the new API work.