Fortran Wrapper Class

ROOT
1

Hi all,
I managed to write a wrapper class, that executes a Fortran function, somehow it works but obvious I didn’t it completely right, as there are still some issues one of them is that cint crashes when loading the .so file twice (reloading it).
I placed a reduced version with working makefile in a tar archive in the attachment. Maybe someone can give me some hints what I made wrong while creating the .so - file,
Thanks,
J.

The makefile executes the following

f77  -Wall -D_REENTRANT -fPIC -I/products/ROOT/3.10_03/gcc-2.95.3/root/include  -c -o fort.o fort.F
g++  -Wall -D_REENTRANT -fPIC -I/products/ROOT/3.10_03/gcc-2.95.3/root/include  -c -o TFtest.o TFtest.C
echo "Generating dictionary TFtestDict.cxx..."
rootcint -f TFtestDict.cxx -c TFtest.h TFtestLinkDef.h
g++  -Wall -D_REENTRANT -fPIC -I/products/ROOT/3.10_03/gcc-2.95.3/root/include  -c -o TFtestDict.o TFtestDict.cxx
g++ -shared -Wl,-soname,TFtest.so -O fort.o TFtest.o TFtestDict.o  -lg2c -o TFtest.so

The Forran file just summs up 2 numbers

      SUBROUTINE SUMME(Ia,Ib,Ic)
      Ic=Ia+Ib
      RETURN
      END

The C-header file declares an class inherited from the TObject Class, and the external Fortran code

#ifndef __TFtest__
#define __TFtest__
 
#include "TObject.h"
 
extern "C" void summe_ (int &a, int &b, int &c);

class TFtest:public TObject
{
 public:
 
  void DoIt(void);

  Int_t fA;
  Int_t fB;
  Int_t fC;
 private:
  Int_t fD;
   ClassDef(TFtest,1)  // Wrapper Class to Fortran
};

The implementation of the class just calls the Fortran subroutine

#include "TFtest.h"
 
ClassImp(TFtest)
 
void TFtest::DoIt(void)
{
  summe_(fA,fB,fC);
}

Ftest.tar.gz (1.03 KB)

2

HI Joe,

can you try and link f2c in addition to g2c? Maybe this helps.
Cheers,
Oliver

3

Thank you for this idea, but as i found out in between the problem is more basic than i thought.
I based the creation of my shared object file on the example “Hello.cxx/Hello.h” in the “test” directory of my root installatoin, but the Hello.so cerated with the original makefile also makes CINT to crash, when loaded twice with the
.L Hello.so
command.
What i would like to have is an .so file that behaves like an .so file that’s created with the ACLIC mechanism (an doesn"t chrash, when reloaded).
Cheers,
J.

4

Note that there seems to be a problem with reloading libraries with gcc 2.95.2

Cheers,
Philippe.