Re: gnuplot c++ interface segfaulting

[Ethan M. <merritt@u.washington.edu>]

On Monday 03 March 2008 16:30, Mojca Miklavec wrote:
> 
> A minimal example includes downloading this code:
>      http://cheminfo.informatics.indiana.edu/~rguha/code/cc++/gnuplot_i++.tgz
> (from http://jijo.cjb.net/)
> and unzipping, making it and running an example
> 
> > cd gnuplot_i++
> /tmp/gnuplot_i++> make
> g++ -c -ggdb -DDEBUGGA  example.cc
> g++ -c -ggdb -DDEBUGGA  gnuplot_i.cc
> g++ -o example -ggdb example.o gnuplot_i.o -lstdc++
> /tmp/gnuplot_i++> ./example

I may be missing something, but what makes you think this fault
involves gnuplot?  It's the example.cc program that is faulting, isn't it?


> *** example of gnuplot control through C++ ***
> 
> Segmentation fault
> 
> ------
> 
> If I run gdb, then I get a problem in fputs reported:
> 
> Program received signal EXC_BAD_ACCESS, Could not access memory.
> Reason: KERN_INVALID_ADDRESS at address: 0x2f706dac
> 0x9002990c in fputs ()

That's not nearly enough information.
Do one or both of the following:

1) Make sure the program is compiled with the -g option
   Run under gdb as before
   When is faults, type   "where"   and inspect the resulting call chain

2) Run the program under valgrind:
   valgrind --tool=memcheck --leak-check=yes --num-callers=20 --leak-resolution=med --log-file=valgrind your-normal-command-line-goes-here
   and inspect the resulting valgrind log file



-- 
Ethan A Merritt