[Bug-zile] zile-2.4.3: libgc dependence, and a workaround

[Nelson H. F. Beebe]

While I have been able to install Hans Boehm's libgc on almost all of
our 25 or so flavors of Unix, MirBSD is an exception.  Today, I tried
about 10 historical versions of libgc on that platform. Several built,
but they all core dumped in their validation tests.

The problem is that zile-2.4.3 (and probably earlier versions) assumes
that libgc is available, but that is not a good assumption, because
libgc isn't a standard package on most systems, and as the MirBSD
experience shows, it may not be buildable.

I made three tweaks to force a build, and now have zile-2.4.3
installed on MirBSD:

%  diff configure.org configure
29701c29701
< if test "x$enable_debug" != "yes"; then
---
> if test "x$enable_debug" == "xyes"; then


%  diff -c main.c.org main.c
*** main.c.org  Sat Dec 17 07:43:43 2011
--- main.c      Fri Dec 23 11:23:44 2011
***************
*** 125,131 ****
--- 125,133 ----
                                               NULL, NULL, NULL, false);
    size_t line = 1;

+ #if 0
    GC_INIT ();
+ #endif
    set_program_name (argv[0]);

    /* Set up Lisp environment now so it's available to files and


%  diff main.c.org main.c
127a128
> #if 0
128a130
> #endif

The configure script tests for the variable enable_debug, but seems
never to set it.  Without the patch I made, configure always tries to
find libgc, and when it does not, it quits immediately.

I hope that the next release of zile can provide a --disable-gc /
--enable-gc configure option pair, with small changes in configure.ac,
main.c, and main.h to avoid attempting to include any form of gc.h,
and trying to invoke GC_INIT (), if --disable-gc has been selected.

-------------------------------------------------------------------------------
- Nelson H. F. Beebe                    Tel: +1 801 581 5254                  -
- University of Utah                    FAX: +1 801 581 4148                  -
- Department of Mathematics, 110 LCB    Internet e-mail: address@hidden  -
- 155 S 1400 E RM 233                       address@hidden  address@hidden -
- Salt Lake City, UT 84112-0090, USA    URL: http://www.math.utah.edu/~beebe/ -
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