Adds BUILD.gn file for protobufs.

This is a first cut of the BUILD.gn file. So far I have protoc
compiling successfully. I have not yet tried to use protoc
and so this may change in a later CL.

I haven't yet created a target that uses a compiled_action() to
trigger the build of protoc. For now I have created a target called
"protoc_host_build" that invokes the "protoc" target and
specifies the host toolchain. We may chose to remove this later.

I found I needed to edit a C++ file that is used during the build.
The file embed.cc generates a C++ file called
"well_known_types_embed.cc" that is used by protoc when generating
.js files. But embed.cc writes its generated output to std::cout
and the bazel file redirects std out to "well_known_types_embed.cc".
Wheras the Bazel file used a "genrule" I used a "compiled_action".
But compiled_action doesn't offer a way to redirect the std out from
the process being invoked so instead I changed the process to take
a flag specifying the output.

Change-Id: I21b07564ac1bbdaa4286e787debd003cc9f53917
5 files changed
tree: 874f5ba577ce1652a4d15c4a66ad51c8b7d48b05
  1. benchmarks/
  2. cmake/
  3. conformance/
  4. csharp/
  5. docs/
  6. editors/
  7. examples/
  8. java/
  9. javanano/
  10. jenkins/
  11. js/
  12. m4/
  13. more_tests/
  14. objectivec/
  15. php/
  16. protoc-artifacts/
  17. python/
  18. ruby/
  19. src/
  20. third_party/
  21. util/
  22. .gitignore
  23. .gitmodules
  24. .travis.yml
  25. appveyor.bat
  26. appveyor.yml
  27. autogen.sh
  28. BUILD
  29. BUILD.gn
  30. CHANGES.txt
  31. composer.json
  32. configure.ac
  33. CONTRIBUTORS.txt
  34. generate_changelog.py
  35. generate_descriptor_proto.sh
  36. gmock.BUILD
  37. LICENSE
  38. Makefile.am
  39. post_process_dist.sh
  40. proto_library.gni
  41. protobuf-lite.pc.in
  42. protobuf.bzl
  43. protobuf.pc.in
  44. Protobuf.podspec
  45. protoc_wrapper.py
  46. README.md
  47. six.BUILD
  48. tests.sh
  49. update_file_lists.sh
  50. WORKSPACE
README.md

Protocol Buffers - Google's data interchange format

Build Status Build status Build Status Build Status Build Status

Copyright 2008 Google Inc.

https://developers.google.com/protocol-buffers/

Overview

Protocol Buffers (a.k.a., protobuf) are Google's language-neutral, platform-neutral, extensible mechanism for serializing structured data. You can find protobuf's documentation on the Google Developers site.

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.

Protocol Compiler Installation

The protocol 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 release page:

https://github.com/google/protobuf/releases

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 repo here:

http://repo1.maven.org/maven2/com/google/protobuf/protoc/

These pre-built binaries are only provided for released versions. If you want to use the github master 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
JavaNanojavanano
JavaScriptjs
Rubyruby
Gogolang/protobuf
PHPphp
Dartdart-lang/protobuf

Usage

The complete documentation for Protocol Buffers is available via the web at:

https://developers.google.com/protocol-buffers/