Re: alloca bug

[Neil Jerram]

Jon Wilson <address@hidden> writes:

> Hi,
> So it looks like the blob in libguile/eval.c (lines 40-56) from the
> autoconf manual to define alloca doesn't work on BSD systems.  This is
> in guile 1.8.1.

One thing to be aware of is that the so-called "portable"
implementation of alloca() in alloca.c just doesn't work with Guile,
because it doesn't really allocate memory on the stack.

In fact, alloca.c was removed for this reason in 2004:

2004-09-08  Marius Vollmer  <address@hidden>

        * Makefile.am (EXTRA_libguile_la_SOURCES): Removed "alloca.c".

Does anyone know what caused it to reappear?  ChangeLog doesn't reveal
anything.

Guile fundamentally requires a real alloca, which means it has to be a
compiler builtin.

Regards,
     Neil