Out of memory not properly detected on scm_* functions

[Matthias Kilian]

Hi,

when running

$ gmake web

on OpenBSD/amd64, lilypond tends to bail out in a very misleading
and confusing way -- it segfaults. This is probably reproducible
on Linux when you limit the data size using ulimit -Sd 524288 (it's
really not necessary that someone actually tries to reproduce it,
but if you're bored...).

The problem is that when memory is tight, several of the scm_*
functions like the scm_call_? family just return NULL. Indeed, some
debugging and tracing showed that guiles garbage collectro tries
to realloc(2), which fails, and then you just get get the NULL.

Unfortunately, lilypond doesn't check the return values of the scm_*
functions, so all you see is the mentioned segfault *somewhere*,
probably after the realloc(2) failed several times.

I'm not a libguile guru, but is there any way to force libguile to
abort(2) immediately if the gc can't gc anything and also can't
request more space from the system? Checking all the SCM's returned
by scm_* function seems to be too cumbersome IMHO.

Ciao,
        Kili

ps: of course this all may be caused by a memory leak in lilypond,
but before checking that, I'd prefer to see lilypond aborting when
the realloc failure happens.


-- 
If your program isn't worth documenting,
it probably isn't worth running.
                -- Nagler