Re: guile-2.0.0 fails to build without threads

[Marco Maggi <marco.maggi-ipsu@poste.it>]

Andy Wingo wrote:

> On Fri 20 May 2011 20:41, Marco Maggi <marco.maggi-ipsu@poste.it> writes:

>> Andy Wingo wrote:
>>> Thanks.  You  seem to  be running on  system in  which the
>>> stack    grows   up.    Is    that   the    case?    Check
>>> libguile/scmconfig.h and config.log.

>> Yes, I have:

>> #define SCM_STACK_GROWS_UP 1 /* 0 or 1 */

>> in "scmconfig.h"; my system is just a i686-pc-linux-gnu.

> But on those systems, the stack grows down, no?

> I suggest that this is a configuration error somehow.  Check your
> config.log.

Someone left  ACTION-IF-FALSE empty  and also left  the test
without "checking" message in this chunk of "configure.ac":

SCM_I_GSC_STACK_GROWS_UP=0
AC_RUN_IFELSE([AC_LANG_SOURCE(
[AC_INCLUDES_DEFAULT
int
find_stack_direction ()
{
  static char *addr = 0;
  auto char dummy;
  if (addr == 0)
    {
      addr = &dummy;
      return find_stack_direction ();
    }
  else
    return (&dummy > addr) ? 1 : -1;
}

int
main ()
{
  return find_stack_direction () < 0;
}])],
	       [SCM_I_GSC_STACK_GROWS_UP=1],
	       [],
	       [AC_MSG_WARN(Guessing that stack grows down -- see scmconfig.h)])

so I  can only guess that  what happens is  described by the
following chunk of "config.log":

configure:39214: checking for iconveh_escape_sequence
configure:39232: gcc -o conftest -O3 -march=i686 -mtune=i686   conftest.c -lcrypt -lm  >&5
configure:39232: $? = 0
configure:39232: ./conftest
configure:39232: $? = 0
configure:39234: result: 2
configure:39295: gcc -o conftest -O3 -march=i686 -mtune=i686   conftest.c -lcrypt -lm  >&5
configure:39295: $? = 0
configure:39295: ./conftest
configure:39295: $? = 0
configure:39310: checking for BDW_GC

the test between  "checking for iconveh_escape_sequence" and
"checking for BDW_GC"; the exit status is zero, which causes
the variable to be correctly set to:

SCM_I_GSC_STACK_GROWS_UP='1'

maybe the problem  is that GCC 4.6.0 with  -O3 optimises the
program in such a way that the test is invalidated.
-- 
Marco Maggi