XL Fortran Enterprise Edition for AIX : User's Guide - IBM

See “Passing Arguments By Reference or By Value” on page 353 and %VAL and
%REF in the XL Fortran Enterprise Edition for AIX Language Reference for more
details.
Passing Data From One Language to Another
The following table shows the data types available in the XL Fortran, Pascal, and C
languages. This section shows how Fortran arguments can be passed by reference
to C programs. To use the Fortran 2003 Draft Standard interoperability features,
such as the BIND(C) attribute and ISO_C_BINDING module support, see the XL
Fortran Enterprise Edition for AIX Language Reference.
Passing Arguments between Languages
Table 24. Corresponding Data Types in Fortran, C, and Pascal. When calling Fortran, the C
and Pascal routines must pass arguments as pointers to the types listed in this table.
XL Fortran Data Types IBM C Data Types XL Pascal Data Types
INTEGER(1), BYTE signed char PACKED -128..127
INTEGER(2) signed short PACKED -32768..32767
INTEGER(4) signed int INTEGER
INTEGER(8) signed long long (see note 1) —
REAL, REAL(4) float SHORTREAL
REAL(8), DOUBLE
PRECISION
double
REAL(16) long double (see note 2) —
REAL
COMPLEX, COMPLEX(4) structure of two floats record of two SHORTREALs
COMPLEX(8), DOUBLE
COMPLEX
structure of two doubles
COMPLEX(16) structure of two long doubles —
record of two REALs
LOGICAL(1) unsigned char PACKED 0..255
LOGICAL(2) unsigned short PACKED 0..65535
LOGICAL(4) unsigned int —
LOGICAL(8)
unsigned long long (see note
1)
CHARACTER char CHAR
CHARACTER(n) char[n] PACKED ARRAY[1..n] OF
CHAR
Integer POINTER void * POINTER, or typed pointer
such as @INTEGER (see note
3)
Array array ARRAY
Sequence-derived type
structure (with C
-qalign=packed option)
—
PACKED RECORD
Notes:
1. Requires the option -qlanglvl=extended in XL C or -qlonglong in C for AIX and C Set
++ for AIX. These are default options for some compilation commands but not for
others.
2. Requires C compiler -qlongdbl option.
3. Requires XL Pascal -qptr4 option.
Interlanguage Calls 349