1)  I'm perplexed as to where to install the cmucl extras on my x86 redhat
linux system.  When I unzip the ".tar.gz" file, the resulting files are:

  lib/cmucl/lib/hemlock11.cursor
  lib/cmucl/lib/hemlock11.mask
  lib/cmucl/lib/mh-scan
  lib/cmucl/lib/motifd
  lib/cmucl/lib/spell-dictionary.bin
  lib/cmucl/lib/XKeysymDB
  lib/cmucl/lib/subsystems/clm-library.x86f
  lib/cmucl/lib/subsystems/clx-library.x86f
  lib/cmucl/lib/subsystems/hemlock-library.x86f

Where do these files go?  I wasn't able to find any documentation.

2)  How much effort is required to build SBCL from the sources?

3)  What are the differences btwn the cmucl a,b,c,d development branches?

-ted

joelh

Get the source tree, cd into it, ./clean.sh, ./make.sh (perhaps with
a parameter to specify the bootstrap host)

Kind regards,

Hannah.

Procedure for building is simple, as Hannah mentioned:

host:/path/to/sbcl$ ./clean.sh # optional
host:/path/to/sbcl$ ./make.sh 'lisp -batch' # for building with cmucl
[ ... wait some time ...]
host:/path/to/sbcl$ cd tests && sh ./run-tests.sh # optional

If you're cross-compiling to a different architecture or OS, it's
marginally more complex; see http://ww.telent.net/sbcl-internals/Build
for more details.

Cheers,

Christophe
--
Jesus College, Cambridge, CB5 8BL                           +44 1223 510 299
http://www-jcsu.jesus.cam.ac.uk/~csr21/                  (defun pling-dollar
(str schar arg) (first (last +))) (make-dispatch-macro-character #\! t)
(set-dispatch-macro-character #\! #\$ #'pling-dollar)

From what I gather, bootstrapping, in this case, means that a lisp system is
needed to build certain parts of the SBCL/CMUCL lisp system, though the
basic parts are buildable / compilable in the normal fashion.  Is this
correct?

-ted

One is that both SBCL and CMUCL are written in Common Lisp[*]. So,
just as you need a C compiler to build your "traditional"
applications, so you need a Lisp compiler to build CMUCL or SBCL.

The second comes from the fact that Lisp is a language in which the
act of compilation and/or loading changes the state of the
compiler.  

A difference (probably the main one) between SBCL and CMUCL is the
method whereby the two systems attempt to deal with this. CMUCL's
build procedure depends on knowledge of CMUCL's own internals;
therefore, CMUCL can only be built with CMUCL itself; moreover, since
the internals can change, it can only be trivially built with a CMUCL
that is not very different from the one you're trying to build;
otherwise, you need to load "bootstrap files" at various points in the
build to change the internals in the course of the compilation.

SBCL, on the other hand, has a build procedure that doesn't depend on
knowledge of its internals; therefore, any sufficiently unbuggy Lisp
compiler can be used to build SBCL, just as any sufficiently unbuggy C
compiler can be used to build applications written in C.

Christophe

[*] Well, mostly
--
Jesus College, Cambridge, CB5 8BL                           +44 1223 510 299
http://www-jcsu.jesus.cam.ac.uk/~csr21/                  (defun pling-dollar
(str schar arg) (first (last +))) (make-dispatch-macro-character #\! t)
(set-dispatch-macro-character #\! #\$ #'pling-dollar)

    Christophe> A difference (probably the main one) between SBCL and CMUCL is the
    Christophe> method whereby the two systems attempt to deal with this. CMUCL's
    Christophe> build procedure depends on knowledge of CMUCL's own internals;
    Christophe> therefore, CMUCL can only be built with CMUCL itself; moreover, since
    Christophe> the internals can change, it can only be trivially built with a CMUCL
    Christophe> that is not very different from the one you're trying to build;
    Christophe> otherwise, you need to load "bootstrap files" at various points in the
    Christophe> build to change the internals in the course of the compilation.

Just one addendum:  sometimes this isn't enough either and you have to
use a cross compiler to build it.  Why?  Because you've made changes
to internal stuff and when you compile and load the changed stuff, it
changes them in the current system and now it no longer matches what
it used to be.  Fun!

There may be cases where even "simple" cross-compilation won't work.
I haven't run into any though.

Ray