[Mehdi3031]

Dear all, Hello!
I am very new to OpenFoam and C++!!! and I am trying to use a static library of thermodynamic for mixture(NH3-H2O) that is written in Fortran90 in MyReactingFoam solver(that I developed). What I have done up to now step by step is this:

1)I have put all the ".f90" files of my Library in this directory:
mehdi@mehdi-Inspiron-7737:~/OpenFOAM/mehdi-3.0.1/platforms/linux64GccDPInt32Opt/lib/LibPropBmNEW$
there I have my library module called "LibPropBM0001.f90" where I manage all the pointers and functions and subroutines that each of this functions are in a separate file and calculate a specific property, like "rhoL.f90", Tbubling.f90", etc.

2) I compiled all these files in the order of their dependencies with gfortran to make the .o files of each,. Therefore, in that folder now I have "rhoL.o", "Tbubling.o", "LibPropBM0001.o"(I produced them by the order of their dependency)
Commands:
gfortran -c rhoL.f90 -o rhoL.o
gfortran -c Tbubling.f90 -o Tbubling.o
...
gfortran -c LibPropBM001.f90 -o LibPropBM001.o

3)Then I made the static library by inserting this command in the shell:
ar cr LibPropBM001.a *.o
and it produced a "LibPropBM001.a" file, so I think library is compiled well!!(is it?!)

4)in the Make/options of "MyReactingFoam", I gave path to this thermodynamics library as following:

EXE_LIBS = \
-lfiniteVolume \
-lfvOptions \
...(etc.)
-lgfortran\
$(HOME)/OpenFOAM/mehdi-3.0.1/platforms/linux64GccDPInt32Opt/lib/LibPropBmNEW/LibPropBM001.a

5)Now when I compile the solver in its directory with "wmake", everything works and it compiles, but when I try to use any of the function of the library somewhere in MyReactingFoam.c like bellow:

int main(int argc, char *argv[])
{
...
Info<< "rhoL = " << rhoL_(300.0,512.0,0.4) << endl;
...
}
I get this error:

MyReactingFoam.C: In function ‘int main(int, char**)’:
MyReactingFoam.C:129:39: error: ‘rhoL_’ was not declared in this scope
Info<< "rhoL =" << rhoL_(300.0,512.0,0.4) << endl;


I don't know how to declare an external function of a library here, I tried to add a header like:
#include "LibPropBM001.a"
or this:
float rhoL_(float ii, float jj, float kk);
etc.
But non worked!! I would appreciate if anybody can give me a hint of what I am missing here and save my head from banging to the keyboard...


Cheers
Mehdi

[jherb]

Did you put

extern"C" {

float rhoL_(float* ii, float* jj, float* kk);

}

Also Fortran functions always take arguments by reference, so your Fortran function is really

float rhoL_(float* ii, float* jj, float* kk);

And you have to call it with pointers to variables so

float a = 300.0;
float b = 512.0;
float c = 0.4;

float result = rhoL_(&a, &b, &c);

Also make sure that you use the right naming convention for your Fortran functions.

See the documentation for
-fno-underscoring
-fsecond-underscore
-fcase-lower
of gfortran.

Perhaps this can help:
http://www.yolinux.com/TUTORIALS/Lin...rtranAndC.html
http://docs.cray.com/books/S-2179-52.../ppgzmrwh.html

[Mehdi3031]

Dear Joachim,
Thank you for your kind answer, It seems that this is the source of my error...!
I tried your suggestion first as following:
I added the Extern "C" part before " int main(int argc, char *argv[]) ", and then inside the main function tried to call rhoL as bellow:
************************************************** *****************************************
extern"C" {
float rhoL_(float* ii, float* jj, float* kk);
}
int main(int argc, char *argv[])
{
...
float a = 300.0; float b = 512.0; float c = 0.4; float result = rhoL_(&a, &b, &c);
Info<< "rhoL is" << result << endl;
...
}
************************************************** ****************************************
But I got this error:

************************************************** ****************************************
In function `main':
MyReactingFoam.C : (.text.startup+0x1544): undefined reference to `rhoL_'
************************************************** ****************************************
I looked at the links and the documentations which is quite complicated to understand, but from what I got, seems that you have to call the Fortran function in upper case letters, so I also tried this:

************************************************** ****************************************
extern"C"
{
float RHOL_(float* ii, float* jj, float* kk);
}
int main(int argc, char *argv[])
{
...
float a = 300.0;
float b = 512.0;
float c = 0.4;
float result = RHOL_(&a, &b, &c);
Info<< "rhoL is" << result << endl;
...
}
************************************************** ****************************************
But still the same (The exact error as before).
what I am not sure if I understood from your reply and the documentations is this part:

Also Fortran functions always take arguments by reference, so your Fortran function is really:
float rhoL_(float* ii, float* jj, float* kk);

Does it mean that in my Fortran Library also I have to change the code and declare everything with underscore "_" ??? Sounds quite strange to me since in Fortran compiler this library is working properly...
If it can help, I will attach the main modules and the rhoL function file as an example so that you can check it out how is it written in Fortran.

By the way, I always thought that extern "C" is for the case that you are using just a function file of Fortran, not a sub function of a library of Fortran that you are addressing to it and using all its functions and subroutines. isn't that true?

[jherb]

I guess the correct name is everything lower case for calling it in OpenFOAM. The case in Fortran should not matter. Take a look in LibPropBM001.a how the function are named there:

strings LibPropBM001.a

or

strings LibPropBM001.a | grep -i rhoL

[Mehdi3031]

Dear Joachim,
Thank you so much...
I looked into the LibPropBM001.a fie as you suggested and realized that gfortran converts all the names of the functions to lower case, therefore I changed "rhoL_" to "rhol_" and now everything works and I can use all the library in OpenFoam .
Thank you once again.

Regards
Mehdi