Add contribution guidelines

.gitignore

@@ -43,6 +43,7 @@ doc/python-apiref.rst
 doc/building-android-binary.rst
 doc/asio_http2.h.rst
 doc/libnghttp2_asio.rst
+doc/contribute.rst
 python/setup.py
 python/dist
 python/MANIFEST

README.rst

@@ -1150,3 +1150,7 @@ to hand over that patch/code to us.  We will credit you for your
 changes as far as possible, to give credit but also to keep a trace
 back to who made what changes.  Please always provide us with your
 full real name when contributing!
+
+See `Contribution Guidelines
+<https://nghttp2.org/documentation/contribute.html>`_ for more
+details.

configure.ac

@@ -597,6 +597,7 @@ AC_CONFIG_FILES([
   doc/nghttp2.h.rst
   doc/nghttp2ver.h.rst
   doc/asio_http2.h.rst
+  doc/contribute.rst
   contrib/Makefile
 ])
 AC_OUTPUT

doc/Makefile.am

@@ -40,6 +40,7 @@ EXTRA_DIST = \
 	sources/libnghttp2_asio.rst \
 	sources/python-apiref.rst \
 	sources/building-android-binary.rst \
+	sources/contribute.rst \
 	_themes/sphinx_rtd_theme/footer.html \
 	_themes/sphinx_rtd_theme/theme.conf \
 	_themes/sphinx_rtd_theme/layout_old.html \

doc/contribute.rst.in

@@ -0,0 +1 @@
+.. include:: @top_srcdir@/doc/sources/contribute.rst

doc/sources/contribute.rst

@@ -0,0 +1,57 @@
+Contribution Guidelines
+=======================
+
+[This text was composed based on 1.2. License section of curl/libcurl
+project.]
+
+When contributing with code, you agree to put your changes and new
+code under the same license nghttp2 is already using unless stated and
+agreed otherwise.
+
+When changing existing source code, you do not alter the copyright of
+the original file(s).  The copyright will still be owned by the
+original creator(s) or those who have been assigned copyright by the
+original author(s).
+
+By submitting a patch to the nghttp2 project, you are assumed to have
+the right to the code and to be allowed by your employer or whatever
+to hand over that patch/code to us.  We will credit you for your
+changes as far as possible, to give credit but also to keep a trace
+back to who made what changes.  Please always provide us with your
+full real name when contributing!
+
+Coding style
+------------
+
+We use clang-format to format source code consistently.  The
+clang-format configuration file .clang-format is located at the root
+directory.  Since clang-format produces slightly different results
+between versions, we currently use clang-format which comes with
+clang-3.5.
+
+To detect any violation to the coding style, we recommend to setup git
+pre-commit hook to check coding style of the changes you introduced.
+The pre-commit file is located at the root directory.  Copy it under
+.git/hooks and make sure that it is executable.  The pre-commit script
+uses clang-format-diff.py to detect any style errors.  If it is not in
+your PATH or it exists under different name (e.g.,
+clang-format-diff-3.5 in debian), either add it to PATH variable or
+add git option ``clangformatdiff.binary`` to point to the script.
+
+For emacs users, integrating clang-format to emacs is very easy.
+clang-format.el should come with clang distribution.  If it is not
+found, download it from `here
+<https://llvm.org/svn/llvm-project/cfe/trunk/tools/clang-format/clang-format.el>`_.
+And add these lines to your .emacs file:
+
+.. code-block:: lisp
+
+    ;; From
+    ;; https://code.google.com/p/chromium/wiki/Emacs#Use_Google's_C++_style!
+    (load "/<path/to>/clang-format.el")
+    (add-hook 'c-mode-common-hook
+         (function (lambda () (local-set-key (kbd "TAB")
+                                             'clang-format-region))))
+
+You can find other editor integration in
+http://clang.llvm.org/docs/ClangFormat.html.

doc/sources/index.rst

@@ -17,6 +17,7 @@ Contents:
    :maxdepth: 2
 
    package_README
+   contribute
    building-android-binary
    tutorial-client
    tutorial-server