Mention libffi dependency in `README'.

[bpt/guile.git] / README

!!! This is not a Guile release; it is a source tree retrieved via
Git or as a nightly snapshot at some random time after the
Guile 1.8 release.  If this were a Guile release, you would not see
this message. !!!  [fixme: zonk on release]

This is a 1.9 development version of Guile, Project GNU's extension
language library.  Guile is an interpreter for Scheme, packaged as a
library that you can link into your applications to give them their
own scripting language.  Guile will eventually support other languages
as well, giving users of Guile-based applications a choice of
languages.

Guile versions with an odd middle number, i.e. 1.9.* are unstable
development versions.  Even middle numbers indicate stable versions.
This has been the case since the 1.3.* series.

The next stable release will likely be version 2.0.0.

Please send bug reports to bug-guile@gnu.org.

See the LICENSE file for the specific terms that apply to Guile.


Additional INSTALL instructions ===========================================

Generic instructions for configuring and compiling Guile can be found
in the INSTALL file.  Guile specific information and configure options
can be found below, including instructions for installing SLIB.

Guile depends on the following external libraries.
- libgmp
- libiconv
- libintl
- libltdl
- libunistring
- libgc
- libffi
It will also use the libreadline library if it is available.  For each
of these there is a corresponding --with-XXX-prefix option that you
can use when invoking ./configure, if you have these libraries
installed in a location other than the standard places (/usr and
/usr/local).

These options are provided by the Gnulib `havelib' module, and details
of how they work are documented in `Searching for Libraries' in the
Gnulib manual (http://www.gnu.org/software/gnulib/manual).  The extent
to which they work on a given OS depends on whether that OS supports
encoding full library path names in executables (aka `rpath').  Also
note that using these options, and hence hardcoding full library path
names (where that is supported), makes it impossible to later move the
built executables and libraries to an installation location other than
the one that was specified at build time.

Another possible approach is to set CPPFLAGS and LDFLAGS on the
configure command-line, so that they include -I options for all the
non-standard places where you have installed header files and -L
options for all the non-standard places where you have installed
libraries.  This will allow configure and make to find those headers
and libraries during the build.  E.g.:

  ../configure [...] CPPFLAGS='-I/my/include' LDFLAGS='-L/my/lib'

The locations found will not be hardcoded into the build executables and
libraries, so with this approach you will probably also need to set
LD_LIBRARY_PATH correspondingly, to allow Guile to find the necessary
libraries again at runtime.


Required External Packages ================================================

Guile requires the following external packages:

  - GNU MP, at least version 4.1

    GNU MP is used for bignum arithmetic.  It is available from
    http://gmplib.org/ .

  - libltdl from GNU Libtool, at least version 1.5.6

    libltdl is used for loading extensions at run-time.  It is
    available from http://www.gnu.org/software/libtool/ .

  - GNU libunistring

    libunistring is used for Unicode string operations, such as the
    `utf*->string' procedures.  It is available from
    http://www.gnu.org/software/libunistring/ .

  - libgc, at least version 7.0

    libgc (aka. the Boehm-Demers-Weiser garbage collector) is the
    conservative garbage collector used by Guile.  It is available
    from http://www.hpl.hp.com/personal/Hans_Boehm/gc/ .

  - libffi

    libffi provides a "foreign function interface", used by the
    `(system foreign)' module.  It is available from
    http://sourceware.org/libffi/ .

  - pkg-config

    Guile's ./configure script uses pkg-config to discover the correct
    compile and link options for libgc.  If you don't have pkg-config
    installed, or you have a version of libgc that doesn't provide a
    .pc file, you can work around this by setting some variables as
    part of the configure command-line:

    - PKG_CONFIG=true

    - BDW_GC_CFLAGS=<compile flags for picking up libgc headers>

    - BDW_GC_LIBS=<linker flags for picking up the libgc library>


Special Instructions For Some Systems =====================================

We would like Guile to build on all systems using the simple
instructions above, but it seems that a few systems still need special
treatment.  If you can send us fixes for these problems, we'd be
grateful.

   <none yet listed>

Guile specific flags Accepted by Configure =================================

If you run the configure script with no arguments, it should examine
your system and set things up appropriately.  However, there are a few
switches specific to Guile you may find useful in some circumstances.

--without-threads  ---  Build without thread support

  Build a Guile executable and library that supports multi-threading.

  The default is to enable threading support when your operating
  system offsers 'POSIX threads'.  When you do not want threading, use
  `--without-threads'.

--enable-deprecated=LEVEL

  Guile may contain features that are `deprecated'.  When a feature is
  deprecated, it means that it is still there, but that there is a
  better way of achieving the same thing, and we'd rather have you use
  this better way.  This allows us to eventually remove the old
  implementation and helps to keep Guile reasonably clean of historic
  baggage.

  Deprecated features are considered harmful; using them is likely a
  bug.  See below for the related notion of `discouraged' features,
  which are OK but have fallen out of favor.

  See the file NEWS for a list of features that are currently
  deprecated.  Each entry will also tell you what you should replace
  your code with.

  To give you some help with this process, and to encourage (OK,
  nudge) people to switch to the newer methods, Guile can emit
  warnings or errors when you use a deprecated feature.  There is
  quite a range of possibilities, from being completely silent to
  giving errors at link time.  What exactly happens is determined both
  by the value of the `--enable-deprecated' configuration option when
  Guile was built, and by the GUILE_WARN_DEPRECATED environment
  variable.

  It works like this:

    When Guile has been configured with `--enable-deprecated=no' (or,
    equivalently, with `--disable-deprecated') then all deprecated
    features are omitted from Guile.  You will get "undefined
    reference", "variable unbound" or similar errors when you try to
    use them.

    When `--enable-deprecated=LEVEL' has been specified (for LEVEL not
    "no"), LEVEL will be used as the default value of the environment
    variable GUILE_WARN_DEPRECATED.  A value of "yes" is changed to
    "summary" and "shutup" is changed to "no", however.

    When GUILE_WARN_DEPRECATED has the value "no", nothing special
    will happen when a deprecated feature is used.

    When GUILE_WARN_DEPRECATED has the value "summary", and a
    deprecated feature has been used, Guile will print this message at
    exit:

      Some deprecated features have been used.  Set the environment
      variable GUILE_WARN_DEPRECATED to "detailed" and rerun the
      program to get more information.  Set it to "no" to suppress
      this message.

    When GUILE_WARN_DEPRECATED has the value "detailed", a detailed
    warning is emitted immediatly for the first use of a deprecated
    feature.

  The default is `--enable-deprecated=yes'.

  In addition to setting GUILE_WARN_DEPRECATED in the environment, you
  can also use (debug-enable 'warn-deprecated) and (debug-disable
  'warn-deprecated) to enable and disable the detailed messaged at run
  time.

--disable-discouraged

  In addition to deprecated features, Guile can also contain things
  that are merely `discouraged'.  It is OK to continue to use these
  features in old code, but new code should avoid them since there are
  better alternatives.

  There is nothing wrong with a discouraged feature per se, but they
  might have strange names, or be non-standard, for example.  Avoiding
  them will make your code better.

--disable-shared  ---  Do not build shared libraries.
--disable-static  ---  Do not build static libraries.

  Normally, both static and shared libraries will be built if your
  system supports them.

--enable-debug-freelist  ---  Enable freelist debugging.

  This enables a debugging version of scm_cell and scm_double_cell,
  and also registers an extra primitive, the setter
  `gc-set-debug-check-freelist!'.

  Configure with the --enable-debug-freelist option to enable the
  gc-set-debug-check-freelist! primitive, and then use:

  (gc-set-debug-check-freelist! #t)  # turn on checking of the freelist
  (gc-set-debug-check-freelist! #f)  # turn off checking

  Checking of the freelist forces a traversal of the freelist and a
  garbage collection before each allocation of a cell.  This can slow
  down the interpreter dramatically, so the setter should be used to
  turn on this extra processing only when necessary.

--enable-debug-malloc  ---  Enable malloc debugging.

  Include code for debugging of calls to scm_malloc, scm_realloc, etc.

  It records the number of allocated objects of each kind.  This is
  useful when searching for memory leaks.

  A Guile compiled with this option provides the primitive
  `malloc-stats' which returns an alist with pairs of kind and the
  number of objects of that kind.

--enable-guile-debug  ---  Include internal debugging functions
--disable-posix       ---  omit posix interfaces
--disable-networking  ---  omit networking interfaces
--disable-regex       ---  omit regular expression interfaces


Cross building Guile  =====================================================

As of guile-1.5.x, the build process uses compiled C files for
snarfing, and (indirectly, through libtool) for linking, and uses the
guile executable for generating documentation.

When cross building guile, you first need to configure, build and
install guile for your build host.

Then, you may configure guile for cross building, eg:

    ./configure --host=i686-pc-cygwin --disable-shared

A C compiler for the build system is required.  The default is
"PATH=/usr/bin:$PATH cc".  If that doesn't suit it can be specified
with the CC_FOR_BUILD variable in the usual way, for instance

    ./configure --host=m68k-unknown-linux-gnu CC_FOR_BUILD=/my/local/gcc

Guile for the build system can be specified similarly with the
GUILE_FOR_BUILD variable, it defaults to just "guile".


Using Guile Without Installing It =========================================

The "meta/" subdirectory of the Guile sources contains a script called
"guile" that can be used to run the Guile that has just been built. Note
that this is not the same "guile" as the one that is installed; this
"guile" is a wrapper script that sets up the environment appropriately,
then invokes the Guile binary.

You may also build external packages against an uninstalled Guile build
tree. The "uninstalled-env" script in the "meta/" subdirectory will set
up an environment with a path including "meta/", a modified dynamic
linker path, a modified PKG_CONFIG_PATH, etc.

For example, you can enter this environment via invoking

    meta/uninstalled-env bash

Within that shell, other packages should be able to build against
uninstalled Guile.


Installing SLIB ===========================================================

In order to use SLIB from Guile you basically only need to put the
`slib' directory _in_ one of the directories on Guile's load path.

The standard installation is:

  1. Obtain slib from http://www-swiss.ai.mit.edu/~jaffer/SLIB.html

  2. Put it in Guile's data directory, that is the directory printed when
     you type

       guile-config info pkgdatadir

     at the shell prompt.  This is normally `/usr/local/share/guile', so the
     directory will normally have full path `/usr/local/share/guile/slib'.

  3. Start guile as a user with write access to the data directory and type

       (use-modules (ice-9 slib))

     at the Guile prompt.  This will generate the slibcat catalog next to
     the slib directory.

SLIB's `require' is provided by the Guile module (ice-9 slib).

Example:

  (use-modules (ice-9 slib))
  (require 'primes)
  (prime? 7)


Guile Documentation ==================================================

If you've never used Scheme before, then the Guile Tutorial
(guile-tut.info) is a good starting point.  The Guile Reference Manual
(guile.info) is the primary documentation for Guile.  A copy of the
R5RS Scheme specification is included too (r5rs.info).

Info format versions of this documentation are installed as part of
the normal build process.  The texinfo sources are under the doc
directory, and other formats like Postscript, PDF, DVI or HTML can be
generated from them with Tex and Texinfo tools.

The doc directory also includes an example-smob subdirectory which has
the example code from the "Defining New Types (Smobs)" chapter of the
reference manual.

The Guile WWW page is at

  http://www.gnu.org/software/guile/guile.html

It contains a link to the Guile FAQ.

About This Distribution ==============================================

Interesting files include:

- LICENSE, which contains the exact terms of the Guile license.
- COPYING.LESSER, which contains the terms of the GNU Lesser General Public License.
- COPYING, which contains the terms of the GNU General Public License.
- INSTALL, which contains general instructions for building/installing Guile.
- NEWS, which describes user-visible changes since the last release of Guile.

Files are usually installed according to the prefix specified to
configure, /usr/local by default.  Building and installing gives you:

Executables, in ${prefix}/bin:

 guile --- a stand-alone interpreter for Guile.  With no arguments, this
        is a simple interactive Scheme interpreter.  It can also be used
        as an interpreter for script files; see the NEWS file for details.
 guile-config --- a Guile script which provides the information necessary
        to link your programs against the Guile library.
 guile-snarf --- a script to parse declarations in your C code for
        Scheme-visible C functions, Scheme objects to be used by C code,
        etc.

Libraries, in ${prefix}/lib.  Depending on the platform and options
        given to configure, you may get shared libraries in addition
        to or instead of these static libraries:

 libguile.a --- an object library containing the Guile interpreter,
        You can use Guile in your own programs by linking against this.
 libguilereadline.a --- an object library containing glue code for the
        GNU readline library.

 libguile-srfi-*.a --- various SRFI support libraries

Header files, in ${prefix}/include:

 libguile.h, guile/gh.h, libguile/*.h --- for libguile.
 guile-readline/readline.h --- for guile-readline.

Support files, in ${prefix}/share/guile/<version>:

 ice-9/* --- run-time support for Guile: the module system,
        read-eval-print loop, some R4RS code and other infrastructure.
 oop/* --- the Guile Object-Oriented Programming System (GOOPS)
 scripts/* --- executable modules, i.e., scheme programs that can be both
        called as an executable from the shell, and loaded and used as a
        module from scheme code.  See scripts/README for more info.
 srfi/* --- SRFI support modules.  See srfi/README for more info.

Automake macros, in ${prefix}/share/aclocal:

 guile.m4

Documentation in Info format, in ${prefix}/info:

 guile --- Guile reference manual.

 guile-tut --- Guile tutorial.

 GOOPS --- GOOPS reference manual.

 r5rs --- Revised(5) Report on the Algorithmic Language Scheme.


The Guile source tree is laid out as follows:

libguile:
        The Guile Scheme interpreter --- both the object library
        for you to link with your programs, and the executable you can run.
ice-9:  Guile's module system, initialization code, and other infrastructure.
guile-config:
        Source for the guile-config script.
guile-readline:
        The glue code for using GNU readline with Guile.  This
        will be build when configure can find a recent enough readline
        library on your system.
doc:    Documentation (see above).

Git Repository Access ================================================

Guile's source code is stored in a Git repository at Savannah.  Anyone
can access it using `git-clone' from one of the following URLs:

  git://git.sv.gnu.org/guile.git
  http://git.sv.gnu.org/r/guile.git

Developers with a Savannah SSH account can also access it from:

  ssh://git.sv.gnu.org/srv/git/guile.git

The repository can also be browsed on-line at the following address:

  http://git.sv.gnu.org/gitweb/?p=guile.git

For more information on Git, please see:

  http://git.or.cz/

Please send problem reports to <bug-guile@gnu.org>.