Segfault: .Call and classes with logical slots

I think you need to PROTECT the vector you're putting in the slot as
well as the overall object.  At any rate, the problem goes away for me
with the revised version of dummy.c below.
yes, and it seems that PROTECT'ing the logical variable is sufficient
while PROTECT'ing the class but not the logical variable causes a
segfault again. I tried with numeric slots too: No problems.
(Empirically, PROTECT'ing
the class definition didn't seem to be needed, but experience suggests
that too much protection  is better than too little.)
I tried to save (UN)PROTECT calls because of efficiency reasons. Anyway,
this helps me a lot, thanks!

Torsten

#include <Rdefines.h>

SEXP foo() {

    SEXP ans, cl, el;

    PROTECT(cl = MAKE_CLASS("test"));
    PROTECT(ans = NEW_OBJECT(cl));
    PROTECT(el = allocVector(LGLSXP, 1));
    SET_SLOT(ans, install("lgl"), el);
    LOGICAL(GET_SLOT(ans, install("lgl")))[0] = TRUE;
    UNPROTECT(3);
    return(ans);
}

Torsten Hothorn wrote:
Hi,

the following example aiming at a class containing a logical slot
segfaults under R-1.9.0 when `gctorture(on = TRUE)' is used:

Code code (dummy.c):

#include <Rdefines.h>

SEXP foo() {

    SEXP ans;

    PROTECT(ans = NEW_OBJECT(MAKE_CLASS("test")));
    SET_SLOT(ans, install("lgl"), allocVector(LGLSXP, 1));
    LOGICAL(GET_SLOT(ans, install("lgl")))[0] = TRUE;
    UNPROTECT(1);
    return(ans);
}

R code (dummy.R):

dyn.load("dummy.so")

setClass("test", representation = representation(lgl = "logical"))

a = .Call("foo")
a # OK

gctorture(on = TRUE)
a = .Call("foo")
gctorture(on = FALSE)
a # segfault

which gives

R>
R>
R> dyn.load("dummy.so")
R>
R> setClass("test", representation = representation(lgl = "logical"))
[1] "test"
R>
R> a = .Call("foo")
R> a
An object of class "test"
Slot "lgl":
[1] TRUE

R>
R> gctorture(on = TRUE)
R> a = .Call("foo")
R> gctorture(on = FALSE)
Segmentation fault

Best,

Torsten

R> version
         _
platform i686-pc-linux-gnu
arch     i686
os       linux-gnu
system   i686, linux-gnu
status
major    1
minor    9.0
year     2004
month    04
day      12
language R
R>

 _______________________________________________________________________
|                                                                       |
|       Dr. rer. nat. Torsten Hothorn                                   |
|       Institut fuer Medizininformatik, Biometrie und Epidemiologie    |
|       Waldstrasse 6, D-91054 Erlangen, Deutschland                    |
|       Tel: ++49-9131-85-22707 (dienstl.)                              |
|       Fax: ++49-9131-85-25740                                         |
|       Email:  Torsten.Hothorn@rzmail.uni-erlangen.de                  |
|               PLEASE send emails cc to torsten@hothorn.de             |
|       Web: http://www.imbe.med.uni-erlangen.de/~hothorn               |
|_______________________________________________________________________|

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Segfault: .Call and classes with logical slots

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