3 Copyright (c) 1996, 1997, 1998, 1999, 2000, 2001, 2002 Free software Foundation, Inc.
5 Permission is granted to anyone to make or distribute verbatim copies
6 of this document as received, in any medium, provided that the
7 copyright notice and permission notice are preserved,
8 and that the distributor grants the recipient permission
9 for further redistribution as permitted by this notice.
11 Permission is granted to distribute modified versions
12 of this document, or of portions of it,
13 under the above conditions, provided also that they
14 carry prominent notices stating who last changed them,
15 and that any new or changed statements about the activities
16 of the Free Software Foundation are approved by the Foundation.
19 What to Hack =========================================================
21 You can hack whatever you want, thank GNU.
23 However, to see what others have indicated as their interest (and avoid
24 potential wasteful duplication of effort), see file TODO. Note that
25 the version you find may be out of date; a CVS checkout is recommended:
26 see below for details (see also the files ANON-CVS and SNAPSHOTS).
28 It's also a good idea to join the guile-devel@gnu.org mailing list.
29 See http://www.gnu.org/software/guile/mail/mail.html for more info.
32 Hacking It Yourself ==================================================
34 When Guile is obtained from CVS, a few extra steps must be taken
35 before the usual configure, make, make install. You will need to have
36 up-to-date versions of the tools listed below, correctly installed.
37 i.e., they must be found in the current PATH and not shadowed or
38 otherwise broken by files left behind from other versions.
40 "up-to-date" means the latest released versions at the time that Guile
41 was obtained from CVS. Sometimes older or newer versions will work.
42 (See below for versions to avoid.)
44 Then you must run the autogen.sh script, as described below.
46 In case of problems, it may be worth getting a fresh copy of Guile
47 from CVS: synchronisation problems have been known to occur
50 The same procedure can be used to regenerate the files in released
51 versions of Guile. In that case the headers of the original generated
52 files (e.g., configure, Makefile.in, ltmain.sh) can be used to
53 identify which tool versions may be required.
55 Autoconf --- a system for automatically generating `configure'
56 scripts from templates which list the non-portable features a
57 program would like to use. Available in
58 "ftp://ftp.gnu.org/pub/gnu/autoconf"
60 Automake --- a system for automatically generating Makefiles that
61 conform to the (rather Byzantine) GNU coding standards. The
62 nice thing is that it takes care of hairy targets like 'make
63 dist' and 'make distclean', and automatically generates
64 Makefile dependencies. Automake is available in
65 "ftp://ftp.gnu.org/pub/gnu/automake"
67 libtool --- a system for managing the zillion hairy options needed
68 on various systems to produce shared libraries. Available in
69 "ftp://ftp.gnu.org/pub/gnu/libtool"
71 gettext --- a system for rigging a program so that it can output its
72 messages in the local tongue. Guile presently only exports
73 the gettext functionality to Scheme, it does not use it
76 flex --- a scanner generator. It's probably not essential to have the
79 One false move and you will be lost in a little maze of automatically
80 generated files, all different.
82 Here is the authoritative list of tool/version/platform tuples that
83 have been known to cause problems, and a short description of the problem.
85 - automake 1.4 adds extraneous rules to the top-level Makefile if
86 you specify specific Makefiles to rebuild on the command line.
88 - automake 1.4-p4 (debian "1:1.4-p4-1.1") all platforms
89 automake "include" facility does not recognize filenames w/ "-".
91 - libtool 1.4 uses acconfig.h, which is deprecated by newest autoconf
92 (which constructs the equivalent through 3rd arg of AC_DEFINE forms).
94 - autoreconf from autoconf prior to 2.59 will run gettextize, which
95 will mess up the Guile tree.
100 Sample GDB Initialization File=========================================
102 Here is a sample .gdbinit posted by Bill Schottstaedt (modified to
103 use `set' instead of `call' in some places):
110 Executes (object->string arg)
115 call gdb_eval(gdb_result)
116 set gdb_print(gdb_result)
120 Executes (print (eval (read arg))): ge "(+ 1 2)" => 3
124 call g_help(scm_str2symbol($arg0), 20)
129 Prints help string for arg: gh "enved-target"
134 so in gdb if you see something useless like:
136 #32 0x081ae8f4 in scm_primitive_load (filename=1112137128) at load.c:129
138 You can get the file name with gp:
141 $1 = 0x40853fac "\"/home/bil/test/share/guile/1.5.0/ice-9/session.scm\""
144 Contributing Your Changes ============================================
146 - If you have put together a change that meets the coding standards
147 described below, we encourage you to submit it to Guile. The best
148 place to post it is guile-devel@gnu.org. Please don't send it
149 directly to me; I often don't have time to look things over. If you
150 have tested your change, then you don't need to be shy.
152 - Please submit patches using either context or unified diffs (diff -c
153 or diff -u). Don't include a patch for ChangeLog; such patches don't
154 apply cleanly, since we've probably changed the top of ChangeLog too.
155 Instead, provide the unaltered text at the top of your patch.
157 - For proper credit, also make sure you update the AUTHORS file
158 (for new files for which you've assigned copyright to the FSF), or
159 the THANKS file (for everything else).
161 Please don't include patches for generated files like configure,
162 aclocal.m4, or any Makefile.in. Such patches are often large, and
163 we're just going to regenerate those files anyway.
166 CVS conventions ======================================================
168 - We use CVS to manage the Guile sources. The repository lives on
169 subversions.gnu.org, in /cvs; you will need an
170 account on that machine to access the repository. Also, for security
171 reasons, subversions presently only supports CVS connections via the SSH
172 protocol, so you must first install the SSH client. Then, you should
173 set your CVS_RSH environment variable to ssh, and use the following as
176 :ext:USER@subversions.gnu.org:/cvs
178 Either set your CVSROOT environment variable to that, or give it as
179 the value of the global -d option to CVS when you check out a working
182 For more information on SSH, see http://www.openssh.com.
184 The Guile sources live in several modules:
186 - guile-core --- the interpreter, QuickThreads, and ice-9
187 - guile-tcltk --- the Guile/Tk interface
188 - guile-tk --- the new Guile/Tk interface, based on STk's modified Tk
189 - guile-rgx-ctax --- the Guile/Rx interface, and the ctax implementation
190 - guile-scsh --- the port of SCSH to guile, talk to Gary Houston
191 - guile-www --- A Guile module for making HTTP requests.
192 - guile-statprof --- an experimental statistical profiler.
194 There is a mailing list for CVS commit messages; see README for details.
196 - The guile-core tree is now versioned similarly to the Linux kernel.
197 Guile now always uses three numbers to represent the version,
198 i.e. "1.6.5". The first number, 1, is the major version number, the
199 second number, 6, is the minor version number, and the third number,
200 5, is the micro version number. Changes in major version number
201 indicate major changes in Guile.
203 Minor version numbers that are even denote stable releases, and odd
204 minor version numbers denote development versions (which may be
205 unstable). The micro version number indicates a minor sub-revision of
206 a given MAJOR.MINOR release.
208 - A default CVS checkout will get the current unstable development
209 tree. However, for each stable release, a CVS branch is created so
210 that release (and ongoing maintenance) of the stable version can
211 proceed independent of the development of the next unstable version.
212 To check out a particular stable branch, you just need to specify "-r
213 branch_release-X-Y" to your CVS checkout command (or to any update).
214 For example, if you wanted to check out the 1.6 stable branch, you
215 would specify "-r branch_release-1-6".
217 So, for example, during a normal development cycle, work will proceed
218 on an unstable version, say 1.5.X, until it is decided that it's time
219 for a stable release. At that point, a branch named
220 branch_release-1-6 will be created, and the version numbers on the
221 HEAD of the CVS tree (the trunk, i.e. what you get by default), will
222 be changed to reflect the new unstable version 1.7.X. Then unstable
223 development will proceed on the unstable version, while the stable
224 1.5.X branch is fixed up for the eventual 1.6.0 release.
226 Anytime you want to yank an existing checked out tree to the stable
227 branch, you can run a command like this:
229 cvs -z3 update -r branch_release-1-6 -Pd
231 This will yank the working directory over on to the stable release
232 branch. Note that this directory will track that branch from then on
233 unless you do something to yank it back to the main (unstable) trunk.
235 To go back to the unstable branch, you can use
237 cvs -z3 update -A -Pd
239 Note that in either case, you should probably make sure you've
240 commited or removed all local changes before running the commands or
241 you're likely to have some unexpected results.
243 Finally note that one approach, should you need to work on both
244 branches, is to keep two trees checked out, one stable, the other
245 unstable and you can work in whichever is appropriate.
247 To save some initial bandwidth, you can check out either the stable
248 tree or the unstable tree, and then do something like this:
250 cp -a core-unstable core-1.5
252 cvs -z3 update -r branch_release-1-6 -Pd
254 - The stable and unstable CVS trees are distinct, and no changes will
255 automatically propagate between them. If you make changes that need
256 to show up both places, you'll need to apply the changes both places.
257 You *might* be able to do this with a cvs command, but often you'll
258 probably need to apply the changes by hand or risk migrating
259 superfluous modifications between the two versions. This is
260 particularly important when moving a change from the unstable branch
261 to the stable branch.
263 - In general, please don't be adventurous with the stable branch. We
264 mostly want bugfixes, documentation improvements, build improvements,
265 etc., though exceptions will doubtless exist.
267 - There are a few CVS tagging conventions which follow the Scheme
268 convention that dashes are used to separate words within a single
269 symbol, and so dashes bind more tightly than underscores. This means
270 that foo-bar_baz-bax indicates that foo-bar is somehow separate from
271 baz-bax. The conventions are as follows:
275 anytime just before you create a branch it's a good
276 idea to create a normal tag so that you can refer to the branch point
277 on the main trunk as well as on the branch. So please use a tag of
280 branch-root-release-1-X
282 or more generally, for other non-release branches:
288 for the branch tag itself please use
292 or more generally, for other non-release branches:
298 Whenever you're merging a branch back into the trunk (or into another
299 branch repeatedly) you need to tag the branch each time you merge. If
300 you don't do that, you won't be able to merge repeatedly without
301 possibly tedious conflicts. For those tags, we suggest:
303 branch-merge_SOME-FOO_to_SOME-BAR_1
304 branch-merge_SOME-FOO_to_SOME-BAR_2
307 As an example, SOME-BAR might be trunk, or even perhaps another branch
308 like branch-mvo-super-fixes :>
310 More mundanely, you might have
312 branch-merge_release-1-6_to_trunk_1
314 (Merging the stable branch to the trunk like this
315 will probably be much more common, when it happens, than the
316 reverse for the reasons mentioned above.
320 When releasing a new version of guile, please use:
328 - If you hack on a stable branch, please apply any relevant patches or
329 fixes to the current unstable version (the main CVS trunk) as well.
330 Similarly, please back-port any important fixes to the unstable CVS
331 tree to the current stable branch.
333 - We check Makefile.am and configure.in files into CVS, but the
334 "autogen.sh" script must be run from the top-level to generate the
335 actual "configure" script that then must be run to create the various
336 Makefile-s to build guile. The general rule is that you should be able
337 to check out a working directory of Guile from CVS, and then type
338 "./autogen.sh", then "configure", and finally "make". No
339 automatically generated files should be checked into the CVS
342 - The .cvsignore file is contained in the repository, to provide a
343 reasonable list of auto-generated files that should not be checked in.
344 This, however, prohibits one from having local additions to the
345 .cvsignore file (yes, you can modify it and never check it in, but
346 that doesn't seem to be a good solution to me). To get around this
347 problem, you might want to patch your cvs program so that it uses a
348 .cvsignore-local file (say) instead of the one from the repository. A
349 patch for this can be found at the very end of this file.
351 - (Automake 1.4 only) Be sure to run automake at the top of the tree
352 with no arguments. Do not use `automake Makefile' to regenerate
353 specific Makefile.in files, and do not trust the Makefile rules to
354 rebuild them when they are out of date. Automake 1.4 will add
355 extraneous rules to the top-level Makefile if you specify specific
356 Makefiles to rebuild on the command line. Running the command
357 `autoreconf --force' should take care of everything correctly.
359 - Make sure your changes compile and work, at least on your own
360 machine, before checking them into the main branch of the Guile
361 repository. A good way for testing this is to run "make distcheck".
362 If you really need to check in untested changes, make a branch.
364 - Include each log entry in both the ChangeLog and in the CVS logs.
365 If you're using Emacs, the pcl-cvs interface to CVS has features to
366 make this easier; it checks the ChangeLog, and generates good default
367 CVS log entries from that.
370 Coding standards =====================================================
372 - Before contributing larger amounts of code to Guile, please read the
373 documents in `guile-core/devel/policy' in the CVS source tree.
375 - As for any part of Project GNU, changes to Guile should follow the
376 GNU coding standards. The standards are available via anonymous FTP
377 from prep.ai.mit.edu, as /pub/gnu/standards/standards.texi and
380 - The Guile tree should compile without warnings under the following
381 GCC switches, which are the default in the current configure script:
383 -O2 -Wall -Wpointer-arith -Wmissing-prototypes
385 To make sure of this, you can use the --enable-error-on-warning option
386 to configure. This option will make GCC fail if it hits a warning.
388 Note that the warnings generated vary from one version of GCC to the
389 next, and from one architecture to the next (apparently). To provide
390 a concrete common standard, Guile should compile without warnings from
391 GCC 2.7.2.3 in a Red Hat 5.2 i386 Linux machine. Furthermore, each
392 developer should pursue any additional warnings noted by on their
393 compiler. This means that people using more stringent compilers will
394 have more work to do, and assures that everyone won't switch to the
395 most lenient compiler they can find. :)
397 Note also that EGCS (as of November 3 1998) doesn't handle the
398 `noreturn' attribute properly, so it doesn't understand that functions
399 like scm_error won't return. This may lead to some silly warnings
400 about uninitialized variables. You should look into these warnings to
401 make sure they are indeed spurious, but you needn't correct warnings
402 caused by this EGCS bug.
404 - If you add code which uses functions or other features that are not
405 entirely portable, please make sure the rest of Guile will still
406 function properly on systems where they are missing. This usually
407 entails adding a test to configure.in, and then adding #ifdefs to your
408 code to disable it if the system's features are missing.
410 - The normal way of removing a function, macro or variable is to mark
411 it as "deprecated", keep it for a while, and remove it in a later
412 release. If a function or macro is marked as "deprecated" it
413 indicates that people shouldn't use it in new programs, and should try
414 to remove it in old. Make sure that an alternative exists unless it
415 is our purpose to remove functionality. Don't deprecate definitions
416 if it is unclear when they will be removed. (This is to ensure that a
417 valid way of implementing some functionality always exists.)
419 When deprecating a definition, always follow this procedure:
421 1. Mark the definition using
423 #if (SCM_DEBUG_DEPRECATED == 0)
427 or, for Scheme code, wrap it using
432 2. Make the deprecated code issue a warning when it is used, by using
433 scm_c_issue_deprecation_warning (in C) or issue-deprecation-warning
436 3. Write a comment at the definition explaining how a programmer can
437 manage without the deprecated definition.
439 4. Add an entry that the definition has been deprecated in NEWS and
440 explain what do do instead.
442 5. In file TODO, there is a list of releases with reminders about what
443 to do at each release. Add a reminder about the removal of the
444 deprecated defintion at the appropriate release.
446 - Please write log entries for functions written in C under the
447 functions' C names, and write log entries for functions written in
448 Scheme under the functions' Scheme names. Please don't do this:
450 * procs.c, procs.h (procedure-documentation): Moved from eval.c.
452 Entries like this make it harder to search the ChangeLogs, because you
453 can never tell which name the entry will refer to. Instead, write this:
455 * procs.c, procs.h (scm_procedure_documentation): Moved from eval.c.
457 Changes like adding this line are special:
459 SCM_PROC (s_map_in_order, "map-in-order", 2, 0, 1, scm_map);
461 Since the change here is about the name itself --- we're adding a new
462 alias for scm_map that guarantees the order in which we process list
463 elements, but we're not changing scm_map at all --- it's appropriate
464 to use the Scheme name in the log entry.
466 - There's no need to keep a change log for a ChangeLog file. For any
467 other kind of file (including documentation, since our documentation
468 is indeed precisely engineered -- we surpass GNU standards here), add
469 an appropriate ChangeLog entry when you change it. Simple!
471 - Make sure you have papers from people before integrating their
472 changes or contributions. This is very frustrating, but very
473 important to do right. From maintain.texi, "Information for
474 Maintainers of GNU Software":
476 When incorporating changes from other people, make sure to follow the
477 correct procedures. Doing this ensures that the FSF has the legal
478 right to distribute and defend GNU software.
480 For the sake of registering the copyright on later versions ofthe
481 software you need to keep track of each person who makes significant
482 changes. A change of ten lines or so, or a few such changes, in a
483 large program is not significant.
485 *Before* incorporating significant changes, make sure that the person
486 has signed copyright papers, and that the Free Software Foundation has
489 If you receive contributions you want to use from someone, let me know
490 and I'll take care of the administrivia. Put the contributions aside
491 until we have the necessary papers.
493 Once you accept a contribution, be sure to keep the files AUTHORS and
496 - When you make substantial changes to a file, add the current year to
497 the list of years in the copyright notice at the top of the file.
499 - When you get bug reports or patches from people, be sure to list
503 Naming conventions =================================================
505 We use certain naming conventions to structure the considerable number
506 of global identifiers. All identifiers should be either all lower
507 case or all upper case. Syllables are separated by underscores `_'.
508 All non-static identifiers should start with scm_ or SCM_. Then might
509 follow zero or more syllables giving the category of the identifier.
510 The currently used category identifiers are
514 c,C - something with a interface suited for C use. This is used
515 to name functions that behave like Scheme primitives but
516 have a more C friendly calling convention.
518 i,I - internal to libguile. It is global, but not considered part
521 f - a SCM variable pointing to a Scheme function object.
523 F - a bit mask for a flag.
525 m - a macro transformer procedure
527 n,N - a count of something
529 s - a constant C string
531 k - a SCM variable pointing to a keyword.
533 sym - a SCM variable pointing to a symbol.
535 var - a SCM variable pointing to a variable object.
537 The follwing syllables also have a technical meaning:
539 str - this denotes a zero terminated C string
541 mem - a C string with an explicit count
544 See also the file `devel/names.text'.
547 Helpful hints ========================================================
549 - [From Mikael Djurfeldt] When working on the Guile internals, it is
550 quite often practical to implement a scheme-level procedure which
551 helps you examine the feature you're working on.
553 Examples of such procedures are: pt-size, debug-hand and
556 I've now put #ifdef GUILE_DEBUG around all such procedures, so that
557 they are not compiled into the "normal" Guile library. Please do the
558 same when you add new procedures/C functions for debugging purpose.
560 You can define the GUILE_DEBUG flag by passing --enable-guile-debug to
561 the configure script.
563 - You'll see uses of the macro SCM_P scattered throughout the code;
564 those are vestiges of a time when Guile was meant to compile on
565 pre-ANSI compilers. Guile now requires ANSI C, so when you write new
566 functions, feel free to use ANSI declarations, and please provide
567 prototypes for everything. You don't need to use SCM_P in new code.
570 Jim Blandy, and others
573 Patches ===========================================================
575 This one makes cvs-1.10 consider the file $CVSDOTIGNORE instead of
576 .cvsignore when that environment variable is set.
579 diff -r -u cvs-1.10/src/cvs.h cvs-1.10.ignore-hack/src/cvs.h
580 --- cvs-1.10/src/cvs.h Mon Jul 27 04:54:11 1998
581 +++ cvs-1.10.ignore-hack/src/cvs.h Sun Jan 23 12:58:09 2000
584 extern int ign_name PROTO ((char *name));
585 void ign_add PROTO((char *ign, int hold));
586 -void ign_add_file PROTO((char *file, int hold));
587 +int ign_add_file PROTO((char *file, int hold));
588 void ign_setup PROTO((void));
589 void ign_dir_add PROTO((char *name));
590 int ignore_directory PROTO((char *name));
591 diff -r -u cvs-1.10/src/ignore.c cvs-1.10.ignore-hack/src/ignore.c
592 --- cvs-1.10/src/ignore.c Mon Sep 8 01:04:15 1997
593 +++ cvs-1.10.ignore-hack/src/ignore.c Sun Jan 23 12:57:50 2000
596 * Open a file and read lines, feeding each line to a line parser. Arrange
597 * for keeping a temporary list of wildcards at the end, if the "hold"
599 + * argument is set. Return true when the file exists and has been handled.
603 ign_add_file (file, hold)
609 if (! existence_error (errno))
610 - error (0, errno, "cannot open %s", file);
612 + error (0, errno, "cannot open %s", file);
615 while (getline (&line, &line_allocated, fp) >= 0)
616 ign_add (line, hold);
619 error (0, errno, "cannot close %s", file);
624 /* Parse a line of space-separated wildcards and add them to the list. */
629 + char *cvsdotignore;
631 /* Set SUBDIRS if we have subdirectory information in ENTRIES. */
637 - ign_add_file (CVSDOTIGNORE, 1);
638 + cvsdotignore = getenv("CVSDOTIGNORE");
639 + if (cvsdotignore == NULL || !ign_add_file (cvsdotignore, 1))
640 + ign_add_file (CVSDOTIGNORE, 1);
642 wrap_add_file (CVSDOTWRAPPER, 1);
644 while ((dp = readdir (dirp)) != NULL)
647 This one is for pcl-cvs-2.9.2, so that `i' adds to the local
651 --- pcl-cvs.el~ Mon Nov 1 12:33:46 1999
652 +++ pcl-cvs.el Tue Jan 25 21:46:27 2000
653 @@ -1177,7 +1177,10 @@
654 "Append the file in FILEINFO to the .cvsignore file.
655 Can only be used in the *cvs* buffer."
656 (save-window-excursion
657 - (set-buffer (find-file-noselect (expand-file-name ".cvsignore" dir)))
658 + (set-buffer (find-file-noselect
659 + (expand-file-name (or (getenv "CVSDOTIGNORE")
662 (goto-char (point-max))
663 (unless (zerop (current-column)) (insert "\n"))