Contribute Code

You are welcome to contribute to project PaddlePaddle. To contribute to PaddlePaddle, you have to agree with the PaddlePaddle Contributor License Agreement.

We sincerely appreciate your contribution. This document explains our workflow and work style.

Workflow

PaddlePaddle uses this Git branching model. The following steps guide usual contributions.

  1. Fork

    Our development community has been growing fastly; it doesn’t make sense for everyone to write into the official repo. So, please file Pull Requests from your fork. To make a fork, just head over to the GitHub page and click the “Fork” button.

  2. Clone

    To make a copy of your fork to your local computers, please run

    git clone https://github.com/your-github-account/paddle
    cd paddle
    
  3. Create the local feature branch

    For daily works like adding a new feature or fixing a bug, please open your feature branch before coding:

    git checkout -b my-cool-stuff
    
  4. Commit

    Before issuing your first git commit command, please install pre-commit by running the following commands:

    pip install pre-commit
    pre-commit install
    

    Our pre-commit configuration requires clang-format 3.8 for auto-formating C/C++ code and yapf for Python.

    Once installed, pre-commit checks the style of code and documentation in every commit. We will see something like the following when you run git commit:

    ➜  git commit
    CRLF end-lines remover...............................(no files to check)Skipped
    yapf.................................................(no files to check)Skipped
    Check for added large files..............................................Passed
    Check for merge conflicts................................................Passed
    Check for broken symlinks................................................Passed
    Detect Private Key...................................(no files to check)Skipped
    Fix End of Files.....................................(no files to check)Skipped
    clang-formater.......................................(no files to check)Skipped
    [my-cool-stuff c703c041] add test file
     1 file changed, 0 insertions(+), 0 deletions(-)
     create mode 100644 233
    

    NOTE: The yapf installed by pip install pre-commit and conda install -c conda-forge pre-commit is slightly different. Paddle developers use pip install pre-commit.

  5. Build and test

    Users can build PaddlePaddle natively on Linux and Mac OS X. But to unify the building environment and to make it easy for debugging, the recommended way is using Docker.

  6. Keep pulling

    An experienced Git user pulls from the official repo often – daily or even hourly, so they notice conflicts with others work early, and it’s easier to resolve smaller conflicts.

    git remote add upstream https://github.com/PaddlePaddle/Paddle
    git pull upstream develop
    
  7. Push and file a pull request

    You can “push” your local work into your forked repo:

    git push origin my-cool-stuff
    

    The push allows you to create a pull request, requesting owners of this official repo to pull your change into the official one.

    To create a pull request, please follow these steps.

    If your change is for fixing an issue, please write “Fixes <issue-URL>” in the description section of your pull request. Github would close the issue when the owners merge your pull request.

    Please remember to specify some reviewers for your pull request. If you don’t know who are the right ones, please follow Github’s recommendation.

  1. Delete local and remote branches

    To keep your local workspace and your fork clean, you might want to remove merged branches:

    git push origin :my-cool-stuff
    git checkout develop
    git pull upstream develop
    git branch -d my-cool-stuff
    

Code Review

  • Please feel free to ping your reviewers by sending them the URL of your pull request via IM or email. Please do this after your pull request passes the CI.
  • Please answer reviewers’ every comment. If you are to follow the comment, please write “Done”; please give a reason otherwise.
  • If you don’t want your reviewers to get overwhelmed by email notifications, you might reply their comments by in a batch.
  • Reduce the unnecessary commits. Some developers commit often. It is recommended to append a sequence of small changes into one commit by running git commit --amend instead of git commit.

Coding Standard

Code Style

Our C/C++ code follows the Google style guide.

Our Python code follows the PEP8 style guide.

Our build process helps to check the code style. In build.sh, the entry point of our builder Docker image, the CMake argument WITH_STYLE_CHECK is set to ON by default. This flag is on

Please install pre-commit, which automatically reformat the changes to C/C++ and Python code whenever we run git commit. To check the whole codebase, we can run the command pre-commit run -a, as in the check_style.sh file, which is invoked by our Travis CI configuration.

Unit Tests

Please remember to add related unit tests.

Writing Logs

We use glog for logging in our C/C++ code.

For general information, please use LOG. For debug information, please use VLOG. The reason is at here.

VLOG requires a verbose level parameter. For example:

VLOG(3) << "Operator FC is taking " << num_inputs << "inputs."

When we run a PaddlePaddle application or test, we can specify a verbose threshold. For example:

GLOG_vmodule=buddy_allocator=2 \
GLOG_v=10 \
python \
../python/paddle/v2/framework/tests/test_recurrent_op.py

This will enable VLOG messages generated by buddy_allocator.{h,cc} and in the verbose range of 0 to 3, so you will see above example VLOG message, which is in level 3. This suggests that we output overall messages in lower verbose levels, so they display with higher probability. When coding C++, please follow the verbose level convention as follows: