# How to contribute We definitely welcome patches and contribution to grpc! Here is some guideline and information about how to do so. ## Getting started ### Legal requirements In order to protect both you and ourselves, you will need to sign the [Contributor License Agreement](https://cla.developers.google.com/clas). ### Technical requirements You will need several tools to work with this repository. In addition to all of the packages described in the [INSTALL](INSTALL.md) file, you will also need python, and the mako template renderer. To install the latter, using pip, one should simply be able to do `pip install mako`. In order to run all of the tests we provide, you will need valgrind and clang. More specifically, under debian, you will need the package libc++-dev to properly run all the tests. Compiling and running grpc C++ tests depend on protobuf 3.0.0, gtest and gflags. Although gflags is provided in third_party, you will need to manually install that dependency on your system to run these tests. Under a Debian or Ubuntu system, you can install the gtests and gflags packages using apt-get: ```sh $ [sudo] apt-get install libgflags-dev libgtest-dev ``` If you are planning to work on any of the languages other than C and C++, you will also need their appropriate development environments. If you want to work under Windows, we recommend the use of Visual Studio 2013. The [Community or Express editions](http://www.visualstudio.com/en-us/downloads/download-visual-studio-vs.aspx) are free and suitable for developing with grpc. Note however that our test environment and tools are available for Unix environments only at the moment. ## Testing your changes We provide a tool to help run the suite of tests in various environments. In order to run most of the available tests, one would need to run: `./tools/run_tests/run_tests.py` If you want to run tests for any of the languages {c, c++, csharp, node, objc, php, python, ruby}, do this: `./tools/run_tests/run_tests.py -l <lang>` To know about the list of available commands, do this: `./tools/run_tests/run_tests.py -h` If you are running tests for ObjC on osx, follow these steps before running tests: * install Xcode command-line tools by running `sudo xcode-select --install` * install macports from https://www.macports.org/install.php * install autoconf, automake, libtool, gflags, cmake using macports * restart your terminal window or run source ~/.bash_profile to pick up the new PATH changes. ## Adding or removing source code Each language uses its own build system to work. Currently, the root's Makefile and the Visual Studio project files are building only the C and C++ source code. In order to ease the maintenance of these files, we have a template system. Please do not contribute manual changes to any of the generated files. Instead, modify the template files, or the build.yaml file, and re-generate the project files using the following command: `./tools/buildgen/generate_projects.sh` You'll find more information about this in the [templates](templates) folder.