.Call and Segmentation Fault
On Sat, 27 Aug 2005, Ricardo Luiz Andrade Abrantes wrote:
Hi! Yes, I am returning a SEXP from the functions called from R, and the problem occurs before (thousands of iterations before) the return point. In fact I runned valgrind into R and when I call ".Call(...) " I got many errors like: ==4324== Use of uninitialised value of size 8 ==4324== at 0x1CB0766D: tnls_ (gencan.f:4101) ==4324== by 0x1CB01962: gencan_ (gencan.f:1876) ==4324== by 0x1CAFECA5: easygencan_ (gencan.f:440) ==4324== by 0x1CB0B47D: algencan_ (algencan.f:517) ==4324== by 0x1CB09E74: easyalgencan_ (algencan.f:76) ==4324== by 0x1CAFE5B3: main (algencanma.c:808) what does not happens when I compile the algencanma as a regular program (not a library) and run it from shell. Valgrind does not find anything wrong when I run the program directly, except 2 missing free() calls. Do you have any ideas where the problem lies (R .Call function or C program)?
It cannot be .Call: your .Call passed no parameters so there was nothing to be uninitialized. I did ask you why you were doing that. .Call is very heavily tested in lots of R applications, so the prior probability of innocence must be very high.
Brian D. Ripley, ripley at stats.ox.ac.uk Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595