This file attempts to describe the rules to use when hacking Bison.

Don't put this file into the distribution.

Everything related to the development of Bison is on Savannah:

http://savannah.gnu.org/projects/bison/

* 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 commit message.

** Bug reports

If somebody reports a new bug, mention his name in the commit message 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.

* Hacking

** Visible changes

Which include serious bug fixes, must be mentioned in NEWS.

** Translations

Only user visible strings are to be translated: error messages, bits of the

.output file etc. This excludes impossible error messages (comparable to

assert/abort), and all the --trace output which is meant for the maintainers

only.

** Horizontal tabs

Do not add horizontal tab characters to any file in Bison's repository

except where required. For example, do not use tabs to format C code.

However, make files, ChangeLog, and some regular expressions require tabs.

Also, test cases might need to contain tabs to check that Bison properly

processes tabs in its input.

* Working from the repository

These notes intend to help people working on the checked-out sources.

These requirements do not apply when building from a distribution tarball.

** Requirements

We've opted to keep only the highest-level sources in the repository. This

eases our maintenance burden, (fewer merges etc.), but imposes more

requirements on anyone wishing to build from the just-checked-out sources.

For example, you have to use the latest stable versions of the maintainer

tools we depend upon, including:

- Autoconf <http://www.gnu.org/software/autoconf/>

- Automake <http://www.gnu.org/software/automake/>

- Flex <http://www.gnu.org/software/flex/>

- Gettext <http://www.gnu.org/software/gettext/>

- Graphviz <http://www.graphviz.org>

- Gzip <http://www.gnu.org/software/gzip/>

- Help2man <http://www.gnu.org/software/help2man/>

- Perl <http://www.cpan.org/>

- Rsync <http://samba.anu.edu.au/rsync/>

- Tar <http://www.gnu.org/software/tar/>

- Texinfo <http://www.gnu.org/software/texinfo/>

Valgrind <http://valgrind.org/> is also highly recommended, if it supports

your architecture.

If you're using a GNU/Linux distribution, the easiest way to install the

above packages depends on your system. The following shell command should

work for Debian-based systems such as Ubuntu:

sudo apt-get install \

autoconf automake autopoint flex graphviz help2man texinfo valgrind

Bison is written using Bison grammars, so there are bootstrapping issues.

The bootstrap script attempts to discover when the C code generated from the

grammars is out of date, and to bootstrap with an out-of-date version of the

C code, but the process is not foolproof. Also, you may run into similar

problems yourself if you modify Bison.

Only building the initial full source tree will be a bit painful. Later,

after synchronizing from the repository a plain 'make' should be sufficient.

Note, however, that when gnulib is updated, running './bootstrap' again

might be needed.

** First checkout

Obviously, if you are reading these notes, you did manage to check out

this package from the repository. For the record, you will find all the

relevant information on:

http://savannah.gnu.org/git/?group=bison

Bison uses Git submodules: subscriptions to other Git repositories.

In particular it uses gnulib, the GNU portability library. To ask Git

to perform the first checkout of the submodules, run

$ git submodule update --init

The next step is to get other files needed to build, which are

extracted from other source packages:

$ ./bootstrap

Bootstrapping updates the submodules to the versions registered in the

top-level directory. To change gnulib, first check out the version you want

in `gnulib`, then commit this change in Bison's repository, and finally run

bootstrap.

If it fails with missing symbols (e.g., "error: possibly undefined macro:

AC_PROG_GNU_M4"), you are likely to have forgotten the submodule

initialization part. Otherwise, there you are! Just

$ ./configure

$ make

$ make check

At this point, there should be no difference between your local copy,

and the master copy:

$ git diff

should output no difference.

Enjoy!

** Updating

The use of submodules make things somewhat different because git does

not support recursive operations: submodules must be taken care of

explicitly by the user.

*** Updating Bison

If you pull a newer version of a branch, say via "git pull", you might

import requests for updated submodules. A simple "git diff" will reveal if

the current version of the submodule (i.e., the actual contents of the

gnulib directory) and the current request from the subscriber (i.e., the

reference of the version of gnulib that the Bison repository requests)

differ. To upgrade the submodules (i.e., to check out the version that is

actually requested by the subscriber, run "git submodule update".

$ git pull

$ git submodule update

*** Updating a submodule

To update a submodule, say gnulib, do as follows:

Get the most recent version of the master branch from git.

$ cd gnulib

$ git fetch

$ git checkout -b master --track origin/master

Make sure Bison can live with that version of gnulib.

$ cd ..

$ ./bootstrap

$ make distcheck

Register your changes.

$ git checkin ...

For a suggestion of what gnulib commit might be stable enough for a formal

release, see the ChangeLog in the latest gnulib snapshot at:

http://erislabs.net/ianb/projects/gnulib/

The Autoconf files we use are currently:

m4/m4.m4

lib/m4sugar/m4sugar.m4

lib/m4sugar/foreach.m4

These files don't change very often in Autoconf, so it should be relatively

straight-forward to examine the differences in order to decide whether to

update.

* Test suite

** make check

Use liberally.

** TESTSUITEFLAGS

The default is for make check to run all tests sequentially. This can be

very time consumming when checking repeatedly or on slower setups. This can

be sped up in two ways:

Using -j, in a make-like fashion, for example:

$ make check TESTSUITEFLAGS='-j8'

Running only the tests of a certain category, as specified in the AT files

with AT_KEYWORDS([[category]]). Categories include:

- c++, for c++ parsers

- deprec, for tests concerning deprecated constructs.

- glr, for glr parsers

- java, for java parsers

- report, for automaton dumps

To run a specific set of tests, use -k (for "keyword"). For example:

$ make check TESTSUITEFLAGS='-k c++'

Both can be combined.

** Typical errors

If the test suite shows failures such as the following one

.../bison/lib/getopt.h:196:8: error: redefinition of 'struct option'

/usr/include/getopt.h:54:8: error: previous definition of 'struct option'

it probably means that some file was compiled without

AT_DATA_SOURCE_PROLOGUE. This error is due to the fact that our -I options

pick up gnulib's replacement headers, such as getopt.h, and this will go

wrong if config.h was not included first.

See tests/local.at for details.

** make maintainer-check-valgrind

This target uses valgrind both to check bison, and the generated parsers.

This is not mature on Mac OS X. First, Valgrind does support the way bison

calls m4, so Valgrind cannot be used to check bison on Mac OS X.

Second, there are many errors that come from the platform itself, not from

bison. build-aux/darwin11.4.0.valgrind addresses some of them.

Third, valgrind issues warnings such as:

--99312:0:syswrap- WARNING: Ignoring sigreturn( ..., UC_RESET_ALT_STACK );

which cause the test to fail uselessly. It is hard to ignore these errors

with a major overhaul of the way instrumentation is performed in the test

suite. So currently, do not try to run valgrind on Mac OS X.

** Release checks

Try to run the test suite with more severe conditions before a

release:

- Configure the package with --enable-gcc-warnings, so that one checks that

1. Bison compiles cleanly, 2. the parsers it produces compile cleanly too.

- Maybe build with -DGNULIB_POSIXCHECK, which suggests gnulib modules that

can fix portability issues. See if you really want to pay attention to

its warnings; there's no need to obey blindly to it

(<http://lists.gnu.org/archive/html/bison-patches/2012-05/msg00057.html>).

- Check with "make syntax-check" if there are issues diagnosed by gnulib.

- run "make maintainer-check" which:

- runs "valgrind -q bison" to run Bison under Valgrind.

- runs the parsers under Valgrind.

- runs the test suite with G++ as C compiler...

- run "make maintainer-check-push", which runs "make maintainer-check" while

activating the push implementation and its pull interface wrappers in many

test cases that were originally written to exercise only the pull

implementation. This makes certain the push implementation can perform

every task the pull implementation can.

- run "make maintainer-check-xml", which runs "make maintainer-check" while

checking Bison's XML automaton report for every working grammar passed to

Bison in the test suite. The check just diffs the output of Bison's

included XSLT style sheets with the output of --report=all and --graph.

- running "make maintainer-check-release" takes care of running

maintainer-check, maintainer-check-push and maintainer-check-xml.

- Change tests/atlocal/CFLAGS to add your preferred options. For instance,

"-traditional" to check that the parsers are K&R. Note that it does not

make sense for glr.c, which should be ANSI, but currently is actually GNU

C, nor for lalr1.cc.

- Test with a very recent version of GCC for both C and C++. Testing with

older versions that are still in use is nice too.

* Release Procedure

This section needs to be updated to take into account features from gnulib.

In particular, be sure to read README-release.

** Update the submodules. See above.

** Update maintainer tools, such as Autoconf. See above.

** Try to get the *.pot files to the Translation Project at least one

week before a stable release, to give them time to translate them. Before

generating the *.pot files, make sure that po/POTFILES.in and

runtime-po/POTFILES.in list all files with translatable strings. This

helps: grep -l '\<_(' *

** Tests

See above.

** Update the foreign files

Running "./bootstrap" in the top level should update them all for you. This

covers PO files too. Sometimes a PO file contains problems that causes it

to be rejected by recent Gettext releases; please report these to the

Translation Project.

** Update README

Make sure the information in README is current. Most notably, make sure it

recommends a version of GNU M4 that is compatible with the latest Bison

sources.

** Check copyright years.

We update years in copyright statements throughout Bison once at the start

of every year by running "make update-copyright". However, before a

release, it's good to verify that it's actually been run. Besides the

copyright statement for each Bison file, check the copyright statements that

the skeletons insert into generated parsers, and check all occurrences of

PACKAGE_COPYRIGHT_YEAR in configure.ac.

** Update NEWS, commit and tag.

See do-release-commit-and-tag in README-release. For a while, we used beta

names such as "2.6_rc1". Now that we use gnulib in the release procedure,

we must use "2.5.90", which has the additional benefit of being properly

sorted in "git tag -l".

** make alpha, beta, or stable

See README-release.

** Upload

There are two ways to upload the tarballs to the GNU servers: using gnupload

(from gnulib), or by hand. Obviously prefer the former. But in either

case, be sure to read the following paragraph.

*** Setup

You need "gnupg".

Make sure your public key has been uploaded at least to keys.gnupg.net. You

can upload it with:

gpg --keyserver keys.gnupg.net --send-keys F125BDF3

where F125BDF3 should be replaced with your key ID.

*** Using gnupload

You need "ncftp".

At the end "make stable" (or alpha/beta) will display the procedure to run.

Just copy and paste it in your shell.

*** By hand

The generic GNU upload procedure is at:

http://www.gnu.org/prep/maintain/maintain.html#Automated-FTP-Uploads

Follow the instructions there to register your information so you're permitted

to upload.

Here's a brief reminder of how to roll the tarballs and upload them:

*** make distcheck

*** gpg -b bison-2.3b.tar.gz

*** In a file named "bison-2.3b.tar.gz.directive", type:

version: 1.1

directory: bison

filename: bison-2.3b.tar.gz

*** gpg --clearsign bison-2.3b.tar.gz.directive

*** ftp ftp-upload.gnu.org # Log in as anonymous.

*** cd /incoming/alpha # cd /incoming/ftp for full release.

*** put bison-2.3b.tar.gz # This can take a while.

*** put bison-2.3b.tar.gz.sig

*** put bison-2.3b.tar.gz.directive.asc

*** Repeat all these steps for bison-2.3b.tar.xz.

** Update Bison manual on www.gnu.org.

*** You need a non-anonymous checkout of the web pages directory.

$ cvs -d YOUR_USERID@cvs.savannah.gnu.org:/web/bison checkout bison

*** Get familiar with the instructions for web page maintainers.

http://www.gnu.org/server/standards/readme_index.html

http://www.gnu.org/server/standards/README.software.html

especially the note about symlinks.

*** Build the web pages.

Assuming BISON_CHECKOUT refers to a checkout of the Bison dir, and

BISON_WWW_CHECKOUT refers to the web directory created above, do:

$ cd $BISON_CHECKOUT/doc

$ make stamp-vti

$ ../build-aux/gendocs.sh -o "$BISON_WWW_CHECKOUT/manual" \

bison "Bison - GNU parser generator"

$ cd $BISON_WWW_CHECKOUT

Verify that the result looks sane.

*** Commit the modified and the new files.

*** Remove old files.

Find the files which have not been overwritten (because they belonged to

sections that have been removed or renamed):

$ cd manual/html_node

$ ls -lt

Remove these files and commit their removal to CVS. For each of these

files, add a line to the file .symlinks. This will ensure that hyperlinks

to the removed files will redirect to the entire manual; this is better than

a 404 error.

There is a problem with 'index.html' being written twice (once for POSIX

function 'index', once for the table of contents); you can ignore this

issue.

** Announce

The "make stable" (or alpha/beta) command just created a template,

$HOME/announce-bison-X.Y. Otherwise, to generate it, run:

make RELEASE_TYPE=alpha gpg_key_ID=F125BDF3 announcement

where alpha can be replaced by beta or stable and F125BDF3 should be

replaced with your key ID.

Complete/fix the announcement file. The generated list of recipients

(info-gnu@gnu.org, bug-bison@gnu.org, help-bison@gnu.org,

bison-patches@gnu.org, and coordinator@translationproject.org) is

appropriate for a stable release or a "serious beta". For any other

release, drop at least info-gnu@gnu.org. For an example of how to fill out

the rest of the template, search the mailing list archives for the most

recent release announcement.

For a stable release, send the same announcement on the comp.compilers

newsgroup by sending email to compilers@iecc.com. Do not make any Cc as the

moderator will throw away anything cross-posted or Cc'ed. It really needs

to be a separate message.

** Prepare NEWS

So that developers don't accidentally add new items to the old NEWS entry,

create a new empty entry in line 3 (without the two leading spaces):

* Noteworthy changes in release ?.? (????-??-??) [?]

Push these changes.

-----

Copyright (C) 2002-2005, 2007-2015, 2018 Free Software Foundation, Inc.

This file is part of GNU Bison.

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 3 of the License, 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/>.

LocalWords: Automake Autoconf Gettext Gzip Rsync Valgrind gnulib submodules

LocalWords: submodule init cd distcheck checkin ChangeLog valgrind sigreturn

LocalWords: UC gcc DGNULIB POSIXCHECK xml XSLT glr lalr README po runtime rc

LocalWords: gnupload gnupg gpg keyserver BDF ncftp filename clearsign cvs dir

LocalWords: symlinks vti html lt POSIX Cc'ed

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mode: outline

fill-column: 76

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