Intel(R) Fortran Compiler for Linux* Systems User's Guide Volume I ...

Intel® Fortran Compiler for Linux* Systems User's Guide, Volume I: Building
Applications
After establishing a consistent interface between mixed-language procedures,
you then need to reconcile any differences in the treatment of individual data
types (strings, arrays, and so on). This is discussed in Exchanging and
Accessing Data in Mixed-Language Programming.
Note
This section uses the term "routine" in a generic way, to refer to functions,
subroutines, and procedures from different languages.
Adjusting Calling Conventions in Mixed-Language Programming
Adjusting Calling Conventions in
Mixed-Language Programming
Overview
The calling convention determines how a program makes a call to a routine, how
the arguments are passed, and how the routines are named. See Adjusting
Naming Conventions in Mixed-Language Programming.
In a single-language program, calling conventions are nearly always correct,
because there is one default for all routines and because header files or Fortran
module files with interface blocks enforce consistency between the caller and the
called routine.
In a mixed-language program, different languages cannot share the same header
files. If, as a result, you link Fortran and C routines that use different calling
conventions, the error is not apparent until the bad call is made at run time.
During execution, the bad call causes indeterminate results and/or a fatal error,
often somewhere in the program that has no apparent relation to the actual
cause: memory/stack corruption due to calling errors. Therefore, you should
check carefully the calling conventions for each mixed-language call.
The discussion of calling conventions between languages applies only to external
procedures. You cannot call internal procedures from outside the program unit
that contains them.
A calling convention affects programming in four ways:
1. The caller routine uses a calling convention to determine the order in which to
pass arguments to another routine; the called routine uses a calling convention to
determine the order in which to receive the arguments passed to it. In Fortran, you
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