HACKING - automake - Git at Google

 ================================================================
 = This file

 * This file attempts to describe the rules to use when hacking
   automake.

 * Don't put this file into the distribution.  Don't mention it in the
   ChangeLog.

 ================================================================
 = Administrivia

 * If you incorporate a change from somebody on the net:
   First, if it is a large change, you must make sure they have signed the
   appropriate paperwork.
   Second, be sure to add their name and email address to THANKS

 * If a change fixes a test, mention the test in the ChangeLog entry.

 * If somebody reports a new bug, mention his name in the ChangeLog entry
   and in the test case you write.  Put him into THANKS.

 * The correct response to most actual bugs is to write a new test case
   which demonstrates the bug.  Then fix the bug, re-run the test suite,
   and check everything in.

 * Some files in the automake package are not owned by automake.  These
   files should never be edited here.  These files are
       COPYING (from FSF),
       INSTALL (autoconf-patches@gnu.org),
       config.guess, config.sub (config-patches@gnu.org),
       texinfo.tex (bug-texinfo@gnu.org),
   Most of them are updated before release with `make fetch'.

 * Changes other than bug fixes must be mentioned in NEWS.  Important
   bug fixes should be mentioned in NES, too.

 ================================================================
 = Naming

 * We've adopted the convention that internal AC_SUBSTs should be
   named with a leading `am__', and internally generated targets should
   be named with a leading `am--'.  This convention is very new
   (as of Feb 7 2001) and so it isn't yet universally used.  But all
   new code should use it.

   We used to use `_am_' as the prefix for an internal AC_SUBST.
   However, it turns out that NEWS-OS 4.2R complains if a Makefile
   variable begins with `_'.  Yay for them.  I changed the target
   naming convention just to be safe.

 ================================================================
 = Editing `.am' files

 * Always use $(...) and not ${...}

 * Use `:', not `true'.  Use `exit 1', not `false'.

 * Use `##' comments liberally.  Comment anything even remotely
   unusual.

 * Never use basename or dirname.  Instead use sed.

 * Do not use `cd' within back-quotes, use `$(am__cd)' instead.
   Otherwise the directory name may be printed, depending on CDPATH.
   More generally, do not ever use plain `cd' together with a relative
   directory that does not start with a dot, or you might end up in one
   computed with CDPATH.

 * For install and uninstall rules, if a loop is required, it should be
   silent.  Then the body of the loop itself should print each
   "important" command it runs.  The printed commands should be preceded
   by a single space.

 ================================================================
 = Editing automake.in and aclocal.in

 * Indent using GNU style.  For historical reasons, the perl code
   contains portions indented using Larry Wall's style (perl-mode's
   default), and other portions using the GNU style (cperl-mode's
   default).  Write new code using GNU style.

 * Don't use & for function calls, unless required.
   The use of & prevents prototypes from being checked.
   Just as above, don't change massively all the code to strip the
   &, just convert the old code as you work on it, and write new
   code without.

 ================================================================
 = Working with git

 * To regenerate dependent files created by aclocal and automake,
   use the `bootstrap' script.  It uses the code from the source
   tree, so the resulting files (aclocal.m4 and Makefile.in) should
   be the same as you would get if you install this version of
   automake and use it to generate those files.  Be sure to have the
   latest stable version of Autoconf installed.  If such version is
   not installed as "autoconf", pass it explicitly (along with the
   accompanying "autom4te") when calling `bootstrap' and `configure'.
   For example:
     $ AUTOCONF=autoconf2.65 AUTOM4TE=autom4te2.65 ./bootstrap
     $ ./configure AUTOCONF=autoconf2.65 AUTOM4TE=autom4te2.65

 * Dependent files aclocal.m4, configure and Makefile.in in all
   directories should be up to date in the git repository, so that
   the changes in them can be easily noticed and analyzed.

 * The git tree currently carries a number of branches: master for the
   current development, and release branches named branch-X.Y.  The maint
   branch serves as common ground for both master and the active release
   branches.  Changes intended for both should be applied to maint, which
   should then be merged to release branches and master, of course after
   suitable testing.  It is advisable to merge only after a set of related
   commits have been applied.

 * Example work flow for patches to maint:

   # 1. Checkout the "maint" branch:
   git checkout maint

   # 2. Apply the patch(es) with "git am" (or create them with $EDITOR):
   git am -3 0*.patch
   # 2a. Run required tests, if any ...

   # 3. Merge maint into branch-1.11:
   git checkout branch-1.11
   git merge maint
   # 3a. Run required tests, if any ...

   # 4. Redo steps 3 and 3a for master:
   git checkout master
   git merge maint
   # testing ...

   # 5. Push the maint and master branches:
   git push --dry-run origin maint branch-1.11 master
   # if all seems ok, then actually push:
   git push origin maint branch-1.11 master

 * When fixing a bug (especially a long-standing one), it may be useful
   to commit the fix to a new temporary branch based off the commit that
   introduced the bug.  Then this "bugfix branch" can be merged into all
   the active branches descending from the buggy commit.  This offers a
   simple way to fix the bug consistently and effectively.

 * There may be a number of longer-lived feature branches for new developments.
   They should be based off of a common ancestor of all active branches to
   which the feature should be merged later.  The next branch may serve as
   common ground for feature merging and testing, should they not be ready
   for master yet.

 * For merges from branches other than maint, prefer 'git merge --log' over
   plain 'git merge', so that a later 'git log' gives an indication of which
   actual patches were merged even when they don't appear early in the list.

 * master and release branches should not be rewound, i.e., should always
   fast-forward, except maybe for privacy issues.  The maint branch should not
   be rewound except maybe after retiring a release branch or a new stable
   release.  For next, and for feature branches, the announcement for the
   branch should document rewinding policy.

 * In order for rebasing and merging of ChangeLog entries to work seamlessly,
   install and configure git-merge-changelog, currently available as gnulib
   module.

 ================================================================
 = Test suite

 * Use "make check" and "make maintainer-check" liberally.

 * Make sure each test file is executable.

 * Use `keep_testdirs=yes' to keep test directories for successful
   tests also.

 * Use perl coverage information to ensure your new code is thoroughly
   tested by your new tests.

 * See file `tests/README' for more information.

 ================================================================
 = Release procedure

 * Fetch new versions of the files that are maintained by the FSF.
   Commit.  Unfortunately you need an FSF account to do this.
   (You can also use `make fetch', but that is still woefully incomplete.)

 * Update NEWS.  For an alpha release, update README-alpha.

 * Update the version number in configure.ac.
   (The idea is that every other alpha number will be a net release.
   The repository will always have its own "odd" number so we can easily
   distinguish net and repo versions.)

 * Update ChangeLog.

 * Run ./bootstrap, ./configure, make.

 * Run `make release-stats' if release statistics in doc/automake.texi
   have not been updated yet.

 * Run `make git-release'.
   This will run distcheck to create the tarballs, commit the last
   NEWS/configure.ac/ChangeLog changes, tag the repository, sign
   the tarballs, and upload them.
   Use `make GNUPLOADFLAGS="--user key" git-release' to sign with
   a non-default key.

 * Update version number in configure.ac to next alpha number.
   Re-run ./bootstrap and commit.

 * Don't forget to `git push' your changes so they appear in the public
   git tree.

 * Update the web pages at sources.redhat.com:
   - bump version in index.rst,
   - add entry to news.rst,
   - run `make' to update .html files,
   - create manuals:
       cd doc
       make pdf
       make html MAKEINFOFLAGS=--no-split
   - copy automake.html and automake.pdf to web cvs,
   - add ChangeLog entry and commit.

 * Update the manuals at www.gnu.org:
   - Generate manuals:
     cd doc
     wget "http://savannah.gnu.org/cgi-bin/viewcvs/~checkout~/texinfo/texinfo/util/gendocs.sh"
     wget "http://savannah.gnu.org/cgi-bin/viewcvs/~checkout~/texinfo/texinfo/util/gendocs_template"
     sh ./gendocs.sh --email bug-automake@gnu.org automake "GNU Automake"
   - copy manuals recursively to web cvs,
   - commit.
   - Check for link errors, fix them, recheck until convergence:
     <http://validator.w3.org/checklink>

 * Send announcement at least to autotools-announce@gnu.org, and
   automake@gnu.org.  If not an alpha, announcement must also go to
   info-gnu@gnu.org.  Copy this announcement into the NEWS feed at
   <https://savannah.gnu.org/projects/automake>.

 -----

 Copyright (C) 2003, 2007, 2008, 2010 Free Software Foundation, Inc.

 This program is free software; you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation; either version 2, or (at your option)
 any later version.

 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.

 Local Variables:
 mode: text
 End:
	================================================================
	= This file

	* This file attempts to describe the rules to use when hacking
	automake.

	* Don't put this file into the distribution. Don't mention it in the
	ChangeLog.

	================================================================
	= Administrivia

	* If you incorporate a change from somebody on the net:
	First, if it is a large change, you must make sure they have signed the
	appropriate paperwork.
	Second, be sure to add their name and email address to THANKS

	* If a change fixes a test, mention the test in the ChangeLog entry.

	* If somebody reports a new bug, mention his name in the ChangeLog entry
	and in the test case you write. Put him into THANKS.

	* The correct response to most actual bugs is to write a new test case
	which demonstrates the bug. Then fix the bug, re-run the test suite,
	and check everything in.

	* Some files in the automake package are not owned by automake. These
	files should never be edited here. These files are
	COPYING (from FSF),
	INSTALL (autoconf-patches@gnu.org),
	config.guess, config.sub (config-patches@gnu.org),
	texinfo.tex (bug-texinfo@gnu.org),
	Most of them are updated before release with `make fetch'.

	* Changes other than bug fixes must be mentioned in NEWS. Important
	bug fixes should be mentioned in NES, too.

	================================================================
	= Naming

	* We've adopted the convention that internal AC_SUBSTs should be
	named with a leading `am__', and internally generated targets should
	be named with a leading `am--'. This convention is very new
	(as of Feb 7 2001) and so it isn't yet universally used. But all
	new code should use it.

	We used to use `_am_' as the prefix for an internal AC_SUBST.
	However, it turns out that NEWS-OS 4.2R complains if a Makefile
	variable begins with `_'. Yay for them. I changed the target
	naming convention just to be safe.

	================================================================
	= Editing `.am' files

	* Always use $(...) and not ${...}

	* Use `:', not `true'. Use `exit 1', not `false'.

	* Use `##' comments liberally. Comment anything even remotely
	unusual.

	* Never use basename or dirname. Instead use sed.

	* Do not use `cd' within back-quotes, use `$(am__cd)' instead.
	Otherwise the directory name may be printed, depending on CDPATH.
	More generally, do not ever use plain `cd' together with a relative
	directory that does not start with a dot, or you might end up in one
	computed with CDPATH.

	* For install and uninstall rules, if a loop is required, it should be
	silent. Then the body of the loop itself should print each
	"important" command it runs. The printed commands should be preceded
	by a single space.

	================================================================
	= Editing automake.in and aclocal.in

	* Indent using GNU style. For historical reasons, the perl code
	contains portions indented using Larry Wall's style (perl-mode's
	default), and other portions using the GNU style (cperl-mode's
	default). Write new code using GNU style.

	* Don't use & for function calls, unless required.
	The use of & prevents prototypes from being checked.
	Just as above, don't change massively all the code to strip the
	&, just convert the old code as you work on it, and write new
	code without.

	================================================================
	= Working with git

	* To regenerate dependent files created by aclocal and automake,
	use the `bootstrap' script. It uses the code from the source
	tree, so the resulting files (aclocal.m4 and Makefile.in) should
	be the same as you would get if you install this version of
	automake and use it to generate those files. Be sure to have the
	latest stable version of Autoconf installed. If such version is
	not installed as "autoconf", pass it explicitly (along with the
	accompanying "autom4te") when calling `bootstrap' and `configure'.
	For example:
	$ AUTOCONF=autoconf2.65 AUTOM4TE=autom4te2.65 ./bootstrap
	$ ./configure AUTOCONF=autoconf2.65 AUTOM4TE=autom4te2.65

	* Dependent files aclocal.m4, configure and Makefile.in in all
	directories should be up to date in the git repository, so that
	the changes in them can be easily noticed and analyzed.

	* The git tree currently carries a number of branches: master for the
	current development, and release branches named branch-X.Y. The maint
	branch serves as common ground for both master and the active release
	branches. Changes intended for both should be applied to maint, which
	should then be merged to release branches and master, of course after
	suitable testing. It is advisable to merge only after a set of related
	commits have been applied.

	* Example work flow for patches to maint:

	# 1. Checkout the "maint" branch:
	git checkout maint

	# 2. Apply the patch(es) with "git am" (or create them with $EDITOR):
	git am -3 0*.patch
	# 2a. Run required tests, if any ...

	# 3. Merge maint into branch-1.11:
	git checkout branch-1.11
	git merge maint
	# 3a. Run required tests, if any ...

	# 4. Redo steps 3 and 3a for master:
	git checkout master
	git merge maint
	# testing ...

	# 5. Push the maint and master branches:
	git push --dry-run origin maint branch-1.11 master
	# if all seems ok, then actually push:
	git push origin maint branch-1.11 master

	* When fixing a bug (especially a long-standing one), it may be useful
	to commit the fix to a new temporary branch based off the commit that
	introduced the bug. Then this "bugfix branch" can be merged into all
	the active branches descending from the buggy commit. This offers a
	simple way to fix the bug consistently and effectively.

	* There may be a number of longer-lived feature branches for new developments.
	They should be based off of a common ancestor of all active branches to
	which the feature should be merged later. The next branch may serve as
	common ground for feature merging and testing, should they not be ready
	for master yet.

	* For merges from branches other than maint, prefer 'git merge --log' over
	plain 'git merge', so that a later 'git log' gives an indication of which
	actual patches were merged even when they don't appear early in the list.

	* master and release branches should not be rewound, i.e., should always
	fast-forward, except maybe for privacy issues. The maint branch should not
	be rewound except maybe after retiring a release branch or a new stable
	release. For next, and for feature branches, the announcement for the
	branch should document rewinding policy.

	* In order for rebasing and merging of ChangeLog entries to work seamlessly,
	install and configure git-merge-changelog, currently available as gnulib
	module.

	================================================================
	= Test suite

	* Use "make check" and "make maintainer-check" liberally.

	* Make sure each test file is executable.

	* Use `keep_testdirs=yes' to keep test directories for successful
	tests also.

	* Use perl coverage information to ensure your new code is thoroughly
	tested by your new tests.

	* See file `tests/README' for more information.

	================================================================
	= Release procedure

	* Fetch new versions of the files that are maintained by the FSF.
	Commit. Unfortunately you need an FSF account to do this.
	(You can also use `make fetch', but that is still woefully incomplete.)

	* Update NEWS. For an alpha release, update README-alpha.

	* Update the version number in configure.ac.
	(The idea is that every other alpha number will be a net release.
	The repository will always have its own "odd" number so we can easily
	distinguish net and repo versions.)

	* Update ChangeLog.

	* Run ./bootstrap, ./configure, make.

	* Run `make release-stats' if release statistics in doc/automake.texi
	have not been updated yet.

	* Run `make git-release'.
	This will run distcheck to create the tarballs, commit the last
	NEWS/configure.ac/ChangeLog changes, tag the repository, sign
	the tarballs, and upload them.
	Use `make GNUPLOADFLAGS="--user key" git-release' to sign with
	a non-default key.

	* Update version number in configure.ac to next alpha number.
	Re-run ./bootstrap and commit.

	* Don't forget to `git push' your changes so they appear in the public
	git tree.

	* Update the web pages at sources.redhat.com:
	- bump version in index.rst,
	- add entry to news.rst,
	- run `make' to update .html files,
	- create manuals:
	cd doc
	make pdf
	make html MAKEINFOFLAGS=--no-split
	- copy automake.html and automake.pdf to web cvs,
	- add ChangeLog entry and commit.

	* Update the manuals at www.gnu.org:
	- Generate manuals:
	cd doc
	wget "http://savannah.gnu.org/cgi-bin/viewcvs/~checkout~/texinfo/texinfo/util/gendocs.sh"
	wget "http://savannah.gnu.org/cgi-bin/viewcvs/~checkout~/texinfo/texinfo/util/gendocs_template"
	sh ./gendocs.sh --email bug-automake@gnu.org automake "GNU Automake"
	- copy manuals recursively to web cvs,
	- commit.
	- Check for link errors, fix them, recheck until convergence:
	<http://validator.w3.org/checklink>

	* Send announcement at least to autotools-announce@gnu.org, and
	automake@gnu.org. If not an alpha, announcement must also go to
	info-gnu@gnu.org. Copy this announcement into the NEWS feed at
	<https://savannah.gnu.org/projects/automake>.

	-----

	Copyright (C) 2003, 2007, 2008, 2010 Free Software Foundation, Inc.

	This program is free software; you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation; either version 2, or (at your option)
	any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with this program. If not, see <http://www.gnu.org/licenses/>.

	Local Variables:
	mode: text
	End: