Swig(Tcl): Can I call Swig function while executing my c++ program? - c++

Question

I have a c++ program which have a Tcl interpreter.
I wrap my functions and add them into Tcl interpreter manually.
Is it possible to wrap and add them by Swig automatically?
Here is the simplified code:
#include <stdio.h>
#include <tcl.h>
class SystemData { // I have a class which link to all the data and function
public:
void print(){
printf("Hello!\n");
};
};
// I wrap the functions manually. But I'm tired to maintain them.
int Hello( ClientData clientData, Tcl_Interp *interp, int argc, const char **argv ) {
SystemData* system = (SystemData*) clientData;
system->print();
}
int main (int argc, char *argv[]) {
Tcl_Interp *interp = Tcl_CreateInterp();;
SystemData* system = new SystemData;
Tcl_CreateCommand( interp, "hello", Hello, (ClientData)system, (Tcl_CmdDeleteProc *)NULL );
Tcl_Eval(interp, "hello"); // I have a Tcl interpreter so that I can call any function in any time
Tcl_DeleteInterp(interp);
}
I have tried to export SystemData to Tcl by Swig:
// swig.cc
#include <stdio.h>
#include <tcl.h>
class SystemData {
public:
void print(){
printf("Hello!\n");
};
};
SystemData* systemData;
int main (int argc, char *argv[]) {
Tcl_Interp *interp = Tcl_CreateInterp();;
systemData = new SystemData;
Tcl_Eval(interp, "load ./swig.so swig");
Tcl_Eval(interp, "puts $systemData");
Tcl_DeleteInterp(interp);
}
My Swig interface:
/* swig.i */
%module swig
%{
/* Put header files here or function declarations like below */
class SystemData;
extern SystemData* systemData;
%}
extern SystemData* systemData;
The compile commands:
swig -tcl swig.i
g++ -fpic -c swig.cc swig_wrap.c -I/usr/local/include
g++ -shared swig.o swig_wrap.o -o swig.so
However, the result of puts $systemData is
NULL
I also tried do not load swig.so
However, the result of puts $systemData is
can't read "systemData": no such variable
Anyone have an idea?

Answer 1

The problem is in the compile commands. My finally commands are:
swig -c++ -tcl swig.i
g++ -fpic -c swig.cc swig_wrap.cxx
g++ -shared swig.o swig_wrap.o -o swig.so
g++ swig.o swig_wrap.o -o swig.out -g -I/usr/local/include -L/usr/local/lib -ltcl8.5
setenv LD_LIBRARY_PATH /usr/local/lib:/usr/local/lib
./swig.out
And the output of above commands are:
swig.i:22: Warning(454): Setting a pointer/reference variable may leak memory.
_906e600000000000_p_SystemData