Fortran Module Names and ATTRIBUTES

Fortran module entities (data and procedures) have external names that differ from other external entities. Module names use the convention:

_MODULENAME_mp_ENTITY [ @stacksize ]

MODULENAME is the name of the module and is all uppercase by default. ENTITY is the name of the module procedure or module data contained within MODULENAME. ENTITY is also uppercase by default. _mp_ is the separator between the module and entity names and is always lowercase.

For example:

    MODULE mymod       INTEGER a    CONTAINS       SUBROUTINE b (j)          INTEGER j       END SUBROUTINE    END MODULE

This results in the following symbols being defined in the compiled .o file on IA-32 systems:

  _MYMOD_mp_A  _MYMOD_mp_B

Or, on ItaniumŪ-based systems:

  MYMOD_mp_A  MYMOD_mp_B

Compiler options can affect the naming of module data and procedures.

Note

Except for ALIAS, ATTRIBUTES options do not affect the module name, which remains uppercase.

The following table shows how each ATTRIBUTES option affects the subroutine in the previous example module.

Effect of ATTRIBUTES Options on Fortran Module Names

ATTRIBUTES Option Given to Routine 'b'

Procedure Name in .o file on IA-32 Systems

Procedure Name in .o file on ItaniumŪ-based Systems

None

_MYMOD_mp_B

MYMOD_mp_B

C

_MYMOD_mp_b

MYMOD_mp_b

STDCALL

_MYMOD_mp_b@4

MYMOD_mp_b

ALIAS

Overrides all others, name as given in the alias

Overrides all others, name as given in the alias

VARYING

No effect on name

No effect on name

You can write code to call Fortran modules or access module data from other languages. As with other naming and calling conventions, the module name must match between the two languages. Generally, this means using the C or STDCALL convention in Fortran, and if defining a module in another language, using the ALIAS option to match the name within Fortran. For examples, see Using Modules in Mixed-Language Programming.