call C from fortran in powerstation v4 required libraries?

[monkeycode]

I am trying a test build of some old code (hence the old compiler). I need to link C and F files, but I am getting the following error

error LNK2001: unresolved external symbol _flow

for each mention of a C file in the F code. Below is an example of how the f files link to the C files.

INTERFACE

SUBROUTINE flow (from, to, when, howmuch)
!MS$ATTRIBUTES C, ALIAS:'_flow' :: flow
REAL from
REAL to
REAL when
REAL howmuch
END SUBROUTINE flow

END INTERFACE

I am struggling to find any suggestions for the compiler I am using, but I suspect that the code is OK (I am assured the model has built from this code previously) and there is something wrong with what I am doing- I am wondering if I don't have the appropriate libraries to tell the compiler I am trying to link to C? I did attempt to download "fortran.h" and add this to my project file but this did not help, and when I added

include 'fortran.h'

to the relevant f files it caused syntax errors.

here is also the fortran.h file I am using

// Definitions for calling FORTRAN 77 from C++

typedef int INTEGER; // INTEGER 4 bytes
typedef float REAL; // REAL 4 bytes
typedef double DOUBLE_PRECISION; // DOUBLE PRECISION 8 bytes
typedef int LOGICAL; // LOGICAL 4 bytes

#include <f77char.h> // character n bytes
#include <f77cmplx.h> // complex
#include <f77matrx.h> // fmatrix class

// values for LOGICAL
#define FALSE 0
#define TRUE 1

// Macros for portable handling of linkage and calling conventions
//#ifdef F77_STUB_REQUIRED
// Typically, this branch is for Unix computers

// C++ stub functions:
#define SUBROUTINE inline void
#define INTEGER_FUNCTION inline INTEGER
#define REAL_FUNCTION inline REAL
#define LOGICAL_FUNCTION inline LOGICAL
#define DOUBLE_PRECISION_FUNCTION inline DOUBLE_PRECISION

// FORTRAN functions
#define SUBROUTINE_F77 extern "C" void
#define INTEGER_FUNCTION_F77 extern "C" int
#define REAL_FUNCTION_F77 extern "C" float
#define LOGICAL_FUNCTION_F77 extern "C" int
#define DOUBLE_PRECISION_FUNCTION_F77 extern "C" double

//#endif

// Array indexing differences between C++ and fortran
//#define B(i) b[i-1]

Thanks for reading- help greatly appreciated, and let me know if more information would be useful!

 

[salgerman]

Hhhmmm...it's been a while, but I have compiled C libraries for use from Fortran...don't remember how exactly I did it, but there is something about that underscore that goes in front of the name...

By the way, I did such compilation and calling of C from Fortran in 3 different platforms (Solaris, Red Hat and Windows) with the 'same' compiler in all 3...I used G95.

Having said that, take a look at the compiler options and see what it is that you could turn off or on...something about that underscore.

I seem to recall not following proper procedure and decided to turn the generation of underscore off during the compilation of Fortran code...I also did not do anything special in the C libraries...and things worked fine.

Try your code with and without the underscore in the name of the function; I am talking about actually hardcoding the underscore and making part of the name in the Fortran sources or wherever...try several combinations...

Hope this helps.

 

[xwb]

1) Are you calling Fortran from C or C from Fortran
2) Is the code being called in a DLL?

 

[monkeycode]

Thanks salgerman,
xwb;
I am trying to call C from fortran, in a DLL


I have managed to fix the unresolved external symbol errors for the c references (I had not told the compiler to link to the correct files, doh!) but am having problems now with some other unresolved externals
__getstdfilex
__max
__min
these are all in my .obj files from c so I assume the problem is what I am doing there - I am using microsoft eMbedded visual C++ and I get this error for max and min;
warning C4013: 'min' undefined; assuming extern returning int
and also
warning C4013: 'perror' undefined; assuming extern returning int
although perror does not come up as an unresolved when I try to link to F....

 

[monkeycode]

fixed by adding

void perror(const char *message);

to code- my stdio.h file is empty!

 

[monkeycode]

also fixed max and min, although, I am still working on the

getstdfilex

part of the error.....

 

[xwb]

I've never used CE before. Find it quite strange that stdio.h is empty but if you are using it for EPROMs then I suppose it makes sense not to assume any kind of I/O.

 

[monkeycode]

I suspect missing bits of library files may be causing my _getstdfilesx error

I do have


// Std handle defns
#define stdin _getstdfilex(0)
#define stdout _getstdfilex(1)
#define stderr _getstdfilex(2)

// functions for general buffered file handling in either ANSI or Wide
_CRTIMP FILE* __cdecl _getstdfilex(int);

but this does not seem to be enough - can anyone tell me all of the library syntax required for this function to work, or direct me to some good resources on the issue- I'm really struggling!
as it doesn't seem to be a problem until I try to link the files to .f .obj files in microsoft developer, I'm wondering if the problem is there?