Naming Conventions for Fortran, C, and C++

The following table summarizes how Fortran, C, and C++ handle procedure names:

Naming Conventions in Fortran, C, and C++

Language	Attributes	Name Translated As	Case of Name in .o File
Fortran	cDEC$ ATTRIBUTES C	_name	All lowercase
Fortran	cDEC$ ATTRIBUTES STDCALL	_name@n	All lowercase
Fortran	default	_name	All uppercase
C	cdecl (default)	_name	Mixed case preserved
C	__stdcall	_name@n	Mixed case preserved
C++	Default	_name@@decoration	Mixed case preserved

In the preceding table:

The leading underscore (such as _name) is used on IA-32 systems only (not on Itanium®-based systems).
@n represents the stack space, in decimal notation, occupied by parameters on IA-32 only (not on Itanium-based systems).

For example, assume a function is declared in C as:

  extern int __stdcall Sum_Up( int a, int b, int c );

Each integer occupies 4 bytes, so the symbol name placed in the .o file on IA-32 systems is:

_Sum_Up@12

On Itanium-based systems, the symbol name placed in the .o file is:

Sum_Up