On Wednesday 28 December 2005 02:24, Simon Beaumont wrote:
> This is SWIPL 5.5.40 compiled with GCC 3.3 on both linux and OSX.
>
> I have a c foreign ND predicate that follows the pattern in the
> documentation.
>
> All works fine except when I CUT (rather than backtrack) and return
> with PL_succeed from the predicate. After printing the result the
> toplevel reports:
>
> Yes
> ERROR: '$toplevel'/0: Caught signal 11 (segv)
>
> This turns out to be in the following.
>
> (gdb) where
> #0 0x0012d4ac in compile_term_to_heap ()
> #1 0x00130f18 in undo_while_saving_term ()
> #2 0x000d46a0 in PL_next_solution ()
> #3 0x0011b4a0 in prologToplevel ()
> #4 0x000e047c in PL_toplevel ()
> #5 0x00001d70 in main ()
> #6 0x00001808 in _start (argc=0, argv=0x1742f4, envp=0x10) at
> /SourceCache/Csu/Csu-47/crt.c:267
> #7 0x8fe1a278 in __dyld__dyld_start ()
>
> All other exits from the predicate are fine (backtracking fully or
> failing).
>
> All my other ND predicates exhibit this exact behaviour but all of the
> deterministic ones are fine.
It would help to see the source of one of these predicates. A common
mistake though is that in the CUT case, the Prolog argument terms are
bogus. Only the context argument carries valid information.
--- Jan
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