Copyright (C) 2003,2007,2008 Free Software Foundation, Inc.
This file is free documentation; the Free Software Foundation gives
unlimited permission to copy, distribute and modify it.


		Prerequisites

You need gcc version 2.0 or later to compile gforth.

For the (documented) libcc.fs C interface you need a C compiler and
libtool at run-time.

For the (undocumented ) lib.fs C interface you need to install either
the ffcall libraries or the libffi library.  Libffi comes with recent
gccs, ffcall can be found on

   ftp://ftp.santafe.edu/pub/gnu/ffcall-1.8.tar.gz (USA) 
   ftp://ftp.ilog.fr/pub/Users/haible/gnu/ffcall-1.8.tar.gz (Europe) 

On many architectures (exceptions: 386, PPC, MIPS, Alpha) you need gdb
at run-time in order for the disassembler to work.


		Building and Installing

First, type

./configure

(see Section Configuration Options below for details).

After configuration, type

make

This includes a check whether your shiny new Forth system works. If
you like to invoke the check alone, do

make check

You can run some benchmarks with

make bench

and compare them with the results in Benchres and in the manual.

If everything is all right, you may want to install gforth. Type

make install

For paper documentation, print gforth.ps (a Postscript file (300dpi
fonts, i.e., it works, but does not produce best quality on better
printers)), or say

make gforth.dvi

and print the resulting file gforth.dvi. You can also get the
documentation in HTML format by typing

make html

If you prefer plain ASCII documentation, you can 

make doc/gforth.txt

or just concatenate the files gforth.info-* ('cat gforth.info-*' under
Unix); the result of the latter option is a little worse.

You can find binary distributions, documentation in HTML and plain
text format and information on known installation problems at
http://www.complang.tuwien.ac.at/forth/gforth/.


		Configuration Options

If you use GNU make, you can build in a directory different from the
source directory by changing to the build directory and invoking
configure thus:

$srcdir/configure

where $srcdir is the source directory. (Note that we tested this only
for installation; i.e., if you want to hack the Gforth sources, you
should probably build in the source directory).

configure has the following useful parameters:
  --prefix=PREFIX         install architecture-independent files in PREFIX
                          [default: /usr/local]
  --exec-prefix=PREFIX    install architecture-dependent files in PREFIX
                          [default: same as prefix]
  --help: tells you about other parameters.

The file Benchres shows the best gforth-fast performance that we
achieved.

If you don't like the defaults for the installation directories, you
should override them already during configure.  E.g., if you want to
install in the /gnu hierarchy instead of in the default /usr/local
hierarchy, say

./configure --prefix=/gnu

Moreover, if your GCC is not called gcc (but, e.g., gcc-2.7.1), you
should say so during configuration. E.g.:

./configure CC=gcc-2.7.1

You can also pass additional options to gcc in this way, e.g., if you
want to generate an a.out executable under Linux with gcc-2.7.0:

./configure CC="gcc -b i486-linuxaout -V 2.7.0"

You can change the sizes of the various areas used in the default
image `gforth.fi' by passing the appropriate Gforth command line
options in the FORTHSIZES environment variable:

./configure "FORTHSIZES=--dictionary-size=1048576 --data-stack-size=16k --fp-stack-size=16K --return-stack-size=15k --locals-stack-size=14848b"

The line above reaffirms the default sizes. Note that the locals
stack area is also used as input buffer stack.

If C's "long long" do not work properly on your machine (i.e., if the
tests involving double-cell numbers fail), you can build Gforth such
that it does not use "long long":

./configure ac_cv_sizeof_long_long=0

For MacOS X on Core 2 processors, you might want to use the 64-bit
version for increased speed (more registers available); you have to
ask for that on configuration, as follows:

./configure CC='gcc-4.2 -arch x86_64' --build=x86_64-apple-darwin9.4.0


			Cross-Installation

There is currently no simple way to do cross-installation of Gforth
(apart from Gforth EC).  The current build process interleaves
compiling and running heavily, so multiple transfers between build and
target machine would be required.  We don't have a testing environment
for cross-compilation, so we cannot fix this at the moment.  If you
want to do cross-installation, please contact us.

In any case, you might find the following useful:

You need a cross-compilation toolchain for your target including gcc
(2.0 or later).

The first step in cross-installation is the cross-configuration.  A
few tests made by the configure script do not work in a
cross-compilation situation. You have to provide the results of these
tests by hand. E.g., if you compile for an ARM:

env skipcode=".skip 16" ac_cv_sizeof_char_p=4 ac_cv_sizeof_void_p=4 \
ac_cv_sizeof_char=1 ac_cv_sizeof_short=2 ac_cv_sizeof_int=4 \
ac_cv_sizeof_long=4 ac_cv_sizeof_long_long=8 ac_cv_sizeof_intptr_t=4 \ 
ac_cv_sizeof_int128_t=0 ac_cv_sizeof_uint128_t=0 \
ac_cv_c_bigendian=no ./configure CC=arm-elf-gcc --host=arm-linux

The ac_cv_sizeof_... variables give the sizes of various C types;
ac_cv_sizeof_char_p is the same as "sizeof(char*)" in C code. The
ac_cv_c_bigendian variable gives the byte order.  The skipcode
specifies how to skip 16 bytes in the code (use "skipcode=no" to
disable skipping and dynamic native code generation).


		Preloading installation-specific code

If you want to have some installation-specific files loaded when
Gforth starts (e.g., an assembler for your processor), put commands
for loading them into /usr/local/share/gforth/site-forth/siteinit.fs
(if the commands work for all architectures) or
/usr/local/lib/gforth/site-forth/siteinit.fs (for
architecture-specific commands);
/usr/local/lib/gforth/site-forth/siteinit.fs takes precedence if both
files are present (unless you change the search path). The file names
given above are the defaults; if you have changed the prefix, you have
to replace "/usr/local" in these names with your prefix.

By default, the installation procedure creates an empty
/usr/local/share/gforth/site-forth/siteinit.fs if there is no such
file.

If you change the siteinit.fs file, you should run "make install"
again for the changes to take effect (Actually, the part of "make
install" starting with "rm gforth.fi" is sufficient).


		Multiple Versions and Deinstallation

Several versions of Gforth can be installed and used at the same
time. Version `foo' can be invoked with `gforth-foo'. We recommend to
keep the old version for some time after a new one has been installed.

You can deinstall this version of Gforth with 'make uninstall' and
version foo with 'make uninstall VERSION=foo'. 'make uninstall' also
tells you how to uninstall Gforth completely.


		Installing Info Files

Info is the GNU project on-line documentation format. You can read
info files either from within Emacs (Ctrl-h i) or using the
stand-alone Info reader, 'info'.

If you use the default install root of '/usr/local' then the info
files will be installed in '/usr/local/info'.

Many GNU/Linux distributions are set up to put all of their
documentation in '/usr/info', in which case you might have to do a
couple of things to get your environment set up to accommodate files
in both areas:

1. Add an INFOPATH environment variable. The easiest place to do
this is '/etc/profile', right next to PATH and MANPATH:

INFOPATH=/usr/local/info:/usr/info

2. Create a file called 'dir' in 'usr/local/info'. Use the file
'/usr/info/dir' as a template. You can add the line for gforth
manually, or use '/sbin/install-info' (man install-info for details).
