/* Fortran <--> C/C++ interfacing stuff */
/* $Id: fortran.h,v 1.8 2001/06/09 10:04:54 jthorn Exp $ */

/* this header file is idempotent */
#ifndef FORTRAN_H_SEEN
#define FORTRAN_H_SEEN

/*****************************************************************************/

/*
 * C/C++ compatability:
 */

/*
 * Use this in prototypes like this:  extern FORTRAN_FUNCTION void foo(...)
 *
 * At present, this is set up to tell a C++ compiler that  foo()  uses
 * a C-compatible calling convention.
 */
#ifdef __cplusplus
  #define FORTRAN_FUNCTION	"C"
#else
  #define FORTRAN_FUNCTION	/* empty */
#endif

/*****************************************************************************/

/* array subscripting offset, i.e. C "arr[k]" is Fortran "arr(k+?)" */
#define FORTRAN_INDEX_ORIGIN	1

/*****************************************************************************/

/* C type of Fortran integer/logical variables */
/* also actual integers used for Fortran logical .true. and .false. */

/*
 * FIXME: these are what I (JT) used on a 32-bit SGI system with the
 *	  SGI C and Fortran compilers in 1992-1993; they should be
 *	  checked to see if they're still valid for current compilers
 *	  and/or for 64-bit systems.
 */
#if   defined(sgi) || defined(SGI) || defined(__sgi__) || defined(__SGI__)
  #define FORTRAN_INTEGER_IS_INT	TRUE
  typedef int integer;
  typedef unsigned int logical;
  #define FORTRAN_LOGICAL_TRUE	1
  #define FORTRAN_LOGICAL_FALSE	0

/* see FIXME above for validity of these */
#elif defined(alpha) || defined(ALPHA) || defined(__alpha__) || defined(__ALPHA__)
  #define FORTRAN_INTEGER_IS_INT	TRUE
  typedef int integer;
  typedef unsigned int logical;
  #define FORTRAN_LOGICAL_TRUE	1
  #define FORTRAN_LOGICAL_FALSE	0

#elif defined(sun) || defined(SUN) || defined(__sun__) || defined(__SUN__)
  #define FORTRAN_INTEGER_IS_INT	TRUE
  typedef int integer;
  typedef unsigned int logical;
  #define FORTRAN_LOGICAL_TRUE	1
  #define FORTRAN_LOGICAL_FALSE	0

#elif defined(__linux__) && defined(__i386__) && defined(__GNUC__)
  #define FORTRAN_INTEGER_IS_INT	TRUE
  typedef int integer;
  typedef unsigned int logical;
  #define FORTRAN_LOGICAL_TRUE	1
  #define FORTRAN_LOGICAL_FALSE	0

#else
  #error "don't know Fortran integer/logical datatypes for this system!"
#endif

/* old (backwards compatible) names for Fortran integers/logicals */
typedef integer fortran_integer_t;
typedef logical fortran_logical_t;

/*****************************************************************************/

/*
 * Names of Fortran routines are often altered by the compiler/loader.  The
 * following macro should be used to call a Fortran routine from C code, i.e.
 *	call sgefa(...)			-- Fortran code
 *	FORTRAN_NAME(sgefa)(...);	-- C code to do the same thing
 *
 * Unfortunately, the "alterations" are generally at the token level, and this
 * can't be done portably in pre-ANSI C.  In ANSI C, the preprocessor "token
 * splicing" facility is designed to handle just this sort of thing, but in
 * pre-ANSI C we have to use rather ugly system-dependent hacks of the sort
 * exemplified below.
 */

/* see FIXME above for validity of these */
#if   defined(sgi) || defined(SGI) || defined(__sgi__) || defined(__SGI__)
  /* C code should reference Fortran names in lower case */
  #ifdef __STDC__
    #define FORTRAN_NAME(n_)	n_ ## _
  #else
    #define FORTRAN_NAME(n_)	n_/**/_
  #endif

/* see FIXME above for validity of these */
#elif defined(alpha) || defined(ALPHA) || defined(__alpha__) || defined(__ALPHA__)
  /* C code should reference Fortran names in lower case */
  #ifdef __STDC__
    #define FORTRAN_NAME(n_)	n_ ## _
  #else
    #define FORTRAN_NAME(n_)	n_/**/_
  #endif

#elif defined(sun) || defined(SUN) || defined(__sun__) || defined(__SUN__)
  /* C code should reference Fortran names in lower case */
  #ifdef __STDC__
    #define FORTRAN_NAME(n_)	n_ ## _
  #else
    #define FORTRAN_NAME(n_)	n_/**/_
  #endif

#elif defined(__linux__) && defined(__i386__) && defined(__GNUC__)
  /* C code should reference Fortran names in lower case */
  #ifdef __STDC__
    #define FORTRAN_NAME(n_)	n_ ## _
  #else
    #define FORTRAN_NAME(n_)	n_/**/_
  #endif

#else
  #error "don't know Fortran integer/logical datatypes for this system!"
#endif

/*****************************************************************************/

#endif	/* FORTRAN_H_SEEN */