Add type tags for view and mut proxies

We're not using these for anything at the moment, but I think it's a good idea
to put them in the gencode now just in case we ever need them.

One thing I have been thinking about in particular is that at some point in the
future we may need generic code to behave differently depending on the vintage
of gencode it is working with. For example, we might want to enable a new
feature on gencode that is new enough to support it, while it leaving it safely
disabled on older gencode. If we ever need to do that, we can create new tags
such as `MessageV2Tag` and thereby distinguish between `EntityType<Tag =
MessageV2Tag>` and `EntityType<Tag = MessageTag>`.

If we ever want to move a trait implementation from the gencode to the runtime,
or vice versa, I think this will also help provide a way to ensure that the
trait is implemented exactly once per type.

Without this CL, we can already do this for owned messages and enums, but this
CL just enables the same possibility for view and mut proxies.

PiperOrigin-RevId: 805412181
4 files changed
tree: f5674b42a8ec3b74f4a5a991eb36e36c5c7e1e6f
  1. .bazelci/
  2. .bcr/
  3. .github/
  4. bazel/
  5. benchmarks/
  6. build_defs/
  7. ci/
  8. cmake/
  9. compatibility/
  10. conformance/
  11. csharp/
  12. docs/
  13. editions/
  14. editors/
  15. examples/
  16. go/
  17. hpb/
  18. hpb_generator/
  19. java/
  20. lua/
  21. objectivec/
  22. patches/
  23. php/
  24. pkg/
  25. python/
  26. ruby/
  27. rust/
  28. src/
  29. third_party/
  30. toolchain/
  31. upb/
  32. upb_generator/
  33. .bazelignore
  34. .bazeliskrc
  35. .bazelrc
  36. .clang-format
  37. .gitignore
  38. .gitmodules
  39. .readthedocs.yml
  40. appveyor.bat
  41. appveyor.yml
  42. BUILD.bazel
  43. Cargo.bazel.lock
  44. Cargo.lock
  45. CMakeLists.txt
  46. CODE_OF_CONDUCT.md
  47. CONTRIBUTING.md
  48. CONTRIBUTORS.txt
  49. Disable_bundle_install.patch
  50. fix_permissions.sh
  51. generate_descriptor_proto.sh
  52. global.json
  53. google3_export_generated_files.sh
  54. LICENSE
  55. maven_dev_install.json
  56. maven_install.json
  57. MODULE.bazel
  58. Neverlink_jruby_jars.patch
  59. PrivacyInfo.xcprivacy
  60. protobuf.bzl
  61. Protobuf.podspec
  62. protobuf_deps.bzl
  63. protobuf_release.bzl
  64. protobuf_version.bzl
  65. README.md
  66. regenerate_stale_files.sh
  67. SECURITY.md
  68. version.json
  69. WORKSPACE
  70. WORKSPACE.bzlmod
README.md

Protocol Buffers - Google's data interchange format

OpenSSF Scorecard

Copyright 2023 Google LLC

Overview

Protocol Buffers (a.k.a., protobuf) are Google's language-neutral, platform-neutral, extensible mechanism for serializing structured data. You can learn more about it in protobuf's documentation.

This README file contains protobuf installation instructions. To install protobuf, you need to install the protocol compiler (used to compile .proto files) and the protobuf runtime for your chosen programming language.

Working With Protobuf Source Code

Most users will find working from supported releases to be the easiest path.

If you choose to work from the head revision of the main branch your build will occasionally be broken by source-incompatible changes and insufficiently-tested (and therefore broken) behavior.

If you are using C++ or otherwise need to build protobuf from source as a part of your project, you should pin to a release commit on a release branch.

This is because even release branches can experience some instability in between release commits.

Bazel with Bzlmod

Protobuf supports Bzlmod with Bazel 7 +. Users should specify a dependency on protobuf in their MODULE.bazel file as follows.

bazel_dep(name = "protobuf", version = <VERSION>)

Users can optionally override the repo name, such as for compatibility with WORKSPACE.

bazel_dep(name = "protobuf", version = <VERSION>, repo_name = "com_google_protobuf")

Bazel with WORKSPACE

Users can also add the following to their legacy WORKSPACE file.

Note that with the release of 30.x there are a few more load statements to properly set up rules_java and rules_python.

http_archive(
    name = "com_google_protobuf",
    strip_prefix = "protobuf-VERSION",
    sha256 = ...,
    url = ...,
)

load("@com_google_protobuf//:protobuf_deps.bzl", "protobuf_deps")

protobuf_deps()

load("@rules_java//java:rules_java_deps.bzl", "rules_java_dependencies")

rules_java_dependencies()

load("@rules_java//java:repositories.bzl", "rules_java_toolchains")

rules_java_toolchains()

load("@rules_python//python:repositories.bzl", "py_repositories")

py_repositories()

Protobuf Compiler Installation

The protobuf compiler is written in C++. If you are using C++, please follow the C++ Installation Instructions to install protoc along with the C++ runtime.

For non-C++ users, the simplest way to install the protocol compiler is to download a pre-built binary from our GitHub release page.

In the downloads section of each release, you can find pre-built binaries in zip packages: protoc-$VERSION-$PLATFORM.zip. It contains the protoc binary as well as a set of standard .proto files distributed along with protobuf.

If you are looking for an old version that is not available in the release page, check out the Maven repository.

These pre-built binaries are only provided for released versions. If you want to use the github main version at HEAD, or you need to modify protobuf code, or you are using C++, it's recommended to build your own protoc binary from source.

If you would like to build protoc binary from source, see the C++ Installation Instructions.

Protobuf Runtime Installation

Protobuf supports several different programming languages. For each programming language, you can find instructions in the corresponding source directory about how to install protobuf runtime for that specific language:

LanguageSource
C++ (include C++ runtime and protoc)src
Javajava
Pythonpython
Objective-Cobjectivec
C#csharp
Rubyruby
Goprotocolbuffers/protobuf-go
PHPphp
Dartdart-lang/protobuf
JavaScriptprotocolbuffers/protobuf-javascript

Quick Start

The best way to learn how to use protobuf is to follow the tutorials in our developer guide.

If you want to learn from code examples, take a look at the examples in the examples directory.

Documentation

The complete documentation is available at the Protocol Buffers doc site.

Support Policy

Read about our version support policy to stay current on support timeframes for the language libraries.

Developer Community

To be alerted to upcoming changes in Protocol Buffers and connect with protobuf developers and users, join the Google Group.