Hi,
I'm trying to access the current R global environment from
within C, using R_GlobalEnv.
In the example below, Rgui (R 1.7.0. Win2K) crashes when I try
to run assignValueToFooInR_GlobalEnv, but not when I run
assignValueToFooInRhoEnv with Rho=.GlobalEnv. Can anyone tell me why?
[ My motivation is that I want use defineVar to initialise a
workingEnvironment (corresponding to Value below), so that event-handler
functions for a specific C library (which must have a specific
prototype) can call R functions by looking up workingEnvironment with
findVar. Earlier, I tried a static global SEXP variable in C to
keep track of the environment, but that's not reliable because
of garbage collection. Maybe SEXPREC would work better? ]
Thanks in advance,
James
***** testR_GlobalEnv.c *****
#include <R.h>
#include <Rinternals.h>
#include <R_ext/Rdynload.h>
#include <R_ext/Memory.h>
#include <R_ext/Applic.h>
static SEXP assignValueToFooInRhoEnv(SEXP Value,SEXP Rho)
{
defineVar(install("Foo"),Value,Rho);
return Value;
}
static SEXP assignValueToFooInR_GlobalEnv(SEXP Value)
{
defineVar(install("Foo"),Value,R_GlobalEnv);
return Value;
}
static const
R_CallMethodDef CallEntries[] = {
{"assignValueToFooInRhoEnv",
(DL_FUNC)&assignValueToFooInRhoEnv,2},
{"assignValueToFooInR_GlobalEnv",
(DL_FUNC)&assignValueToFooInR_GlobalEnv,1},
{NULL,NULL,0}
};
void R_init_testR_GlobalEnv(DllInfo *info)
{
R_registerRoutines(info,NULL,CallEntries,NULL,NULL);
}
***** In R *****