path: root/README-hacking

These notes intend to help people working on the checked-out sources.
They don't apply when you are building from a distribution tarball.

If you want to submit a patch, please start from checked-out sources
rather than the source tarball.


Prerequisites
=============

 * git (to check out both findutils and gnulib).
 * A C compiler, linker and software development libraries (the standard
   C library).  Any compiler compliant with the 1990 ISO C standard running
   on a POSIX system should work.
 * GNU Autoconf
 * GNU Automake
 * GNU m4
 * GNU gettext
 * GNU Dejagnu

Dejagnu is in fact optional, but it's strongly recommended, since it is
needed to run findutils' test suite (which is how you know that find
works once it is built on your system).

The configure program should tell you if you try to use a version of
one of these tools which is not of a recent enough version.  The file
tool-versions.txt indicates which version of each tool the current
release was built and tested with.  This is included in the tar-file
releases, but it's not checked in to git.


Use the latest upstream sources
===============================

1. Check out the findutils code

  git clone git://git.sv.gnu.org/findutils

This will download the whole repository, it's about 16MB once fetched.
If you already have a copy you can refresh it with:

  git checkout master  (to switch to your copy of the master branch)
  git pull (to collect and merge changes)

2. Generate a gnulib installation within the findutils source tree

 Change your working directory to the findutils source directory (that
 is, the directory containing this file).   Then run the following
 command:-

    ./bootstrap

 This command will use git to check out the version of gnulib which is
 intended to work with the findutils source you already have (gnulib
 is used as a git submodule).  The gnulib code itself is left in the
 directory "gnulib".  The "gl" directory contains just the gnulib
 files that findutils needs during the build process.

 This will also run Autoconf and Automake to generate the "configure"
 script and "Makefile.in" files.

3. Run "./configure" and "make" in the normal way.

 If you have GNU libintl installed, you can just run "./configure".
 Otherwise, run "./configure --disable-nls".

You are now at the point where your local directory looks just like it
would after building a source release, except that your copy is more
up-to-date.

*Before* you commit changes
===========================

In this project, we much prefer patches that automatically record
authorship.  That is important not just to give credit where due, but
also from a legal standpoint (see below).  To create author-annotated
patches with git, you must first tell git who you are.  That information
is best recorded in your ~/.gitconfig file.  Edit that file, creating
it if needed, and put your name and email address in place of these
example values:

[user]
  name = Joe X. User
  email = joe.user@example.com


Required format for check-in messages
=====================================

We use a specific style for check-in messages.  See "git log" for
examples.  The format corresponds to the standard GNU ChangeLog
format, but without date & author headers (since git provides this
data) and without a left margin (since there are no headers).

--- example begins ---
Don't overflow sig_atomic_t for --max-procs.

* xargs/xargs.c (__STDC_LIMIT_MACROS): Define __STDC_LIMIT_MACROS
in order to ensure that <stdint.h> defines the SIG_ATOMIC_MAX
macro, which we need.
(MAX_PROC_MAX): Define this as the maximum allowed value of
proc_max.
(main): Show the value of MAX_PROC_MAX for --show-limits.
(increment_proc_max): Don't increment proc_max beyond
MAX_PROC_MAX.
--- example ends ---

There are several things to notice about this checkin message.  Most
importantly, it begins with a single line summary of the whole change.
This needs to be short.  It would be used as the subject line of
patches mailed by "git send-email".  Some people begin that line with
a one-word tag indicating what is affected (for example find: for
changes to find, doc: to changes to the documentation, maint: for
changes to the maintainer automation and so forth).

All changes to a file are grouped together in an entry which begins with
an asterisk (*) and the file name.  The name of the modified function
(if any) follows immediately in parentheses followed by a colon.  If
you're modifying a file for which "function" isn't the logical unit of
organisation, use whatever seems most useful.  For example when
modifying the Texinfo source, use the section name.

After the colon, describe the change you made to that function.  If
you made a related change mention the places you made that change,
too.  If you made many individually small changes, you can summarise
these if they're not individually interesting.  For example you could
just say "Update all callers to remove this function argument".  If
that change spans several files, mention the other files modified.

Note for maintainers:
Prior to pushing a commit in the name of someone else to the public
Git repository, please check if that person has undergone the
"Copyright assignment" process for GNU findutils described below, or -
in case of a trivial change (<10 lines, cumulatively with all their
previous contributions) - document that such paperwork is not required
by adding this line to the commit message:

  Copyright-paperwork-exempt: Yes


Making commits locally
======================

You will normally find it much easier to work on a branch.  This
allows you to maintain your changes and test them without being
affected by changes on the trunk.

To Make a "topic" branch for your change, do this:

  git branch my-topic
  git checkout my-topic

You can then work on your branch as normal.

To update your local repository, do this:

  git checkout master
  git pull

Then, rebase your topic branch to take into account the upstream
changes you just pulled:

  git checkout my-topic
  git rebase master

There are some useful checks that git commit hooks will do for you,
it's a good idea to enable these:

  mv .git/hooks/pre-commit.sample .git/hooks/pre-commit


Submitting patches
==================

If you plan to submit changes to findutils, please make sure you have
read the GNU coding standard (https://www.gnu.org/prep/standards/).
Some common things you might have forgotten to do are:

 - document your change in both the manual pages and the Texinfo file
 - re-run the test suite (with Dejagnu installed!)
 - add a test case for the bug you're fixing or feature you're adding
 - mention your fix or change (if it's significant) in the NEWS file
 - commit using a descriptive commit message

If you have patches, please generate them with "git format-patch" and
mail them to these addresses:

  bug-findutils@gnu.org, findutils-patches@gnu.org

Here is a complete session

  # set up your topic branch
  git checkout master
  git pull
  git branch my-topic
  git checkout my-topic

  # update the code, documentation, test suite and change log, run tests
  emacs xargs/xargs.c
  emacs doc/find.texi xargs/xargs.1
  emacs xargs/testsuite/Makefile.am  xargs/testsuite/xargs.gnu/blah.exp
  make check
  emacs NEWS

  # make sure you didn't break anything
  make syntax-check
  make distcheck

  # commit the change and send the patches.
  git add -u
  git commit
  git rebase master
  mkdir /tmp/patches
  git format-patch -o /tmp/patches master..HEAD
  git send-email --compose \
      --to bug-findutils@gnu.org \
      --cc findutils-patches@gnu.org /tmp/patches


Copyright assignment
====================

If your change is significant (i.e., if it adds more than ~10 lines),
then you'll have to have a copyright assignment on file with the FSF.
Since that involves first an email exchange between you and the FSF,
and then the exchange (FSF to you, then back) of an actual sheet of
paper with your signature on it, and finally, some administrative
processing in Boston, the process can take a few weeks (for
contributors in some geographies, this can all be done electronically,
saving a lot of time).

The forms to choose from are in gnulib's doc/Copyright/ directory.
If you want to assign a single change, you should use the file,
doc/Copyright/request-assign.changes:

    https://git.sv.gnu.org/gitweb/?p=gnulib.git;a=blob;f=doc/Copyright/request-assign.changes;hb=HEAD

If you would like to assign past and future contributions to a project,
you'd use doc/Copyright/request-assign.future:

    https://git.sv.gnu.org/gitweb/?p=gnulib.git;a=blob;f=doc/Copyright/request-assign.future;hb=HEAD

You may make assignments for up to four projects at a time.

In case you're wondering why we bother with all of this, read this:

    https://www.gnu.org/licenses/why-assign.html


========================================================================
Copyright (C) 2009-2023 Free Software Foundation, Inc.

Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.3 or
any later version published by the Free Software Foundation; with no
Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.
A copy of the license is included in the ``GNU Free Documentation
License'' file as part of this distribution.