C/C++ Programmer's Guide (G06.27+, H06.03+)

C and C++ Extensions
HP C/C++ Programmer’s Guide for NonStop Systems—429301-010
2-10
Declarations
Attribute Specifier
The attribute specifier is an HP extension. It is used for writing system-level C and C++
functions and for declaring external routines written in other languages.
The attribute specifier is applicable only in the Guardian environment.
language-specifier
A language-specifier for a function prototype specifies the language of the
body of the external routine being declared.
Considerations for the Native Compilers Only
•
Native C and C++ support mixed-language programs with modules written in
the C, C++, native COBOL85, and native pTAL languages. Therefore, the only
language specifiers that apply are
_c, _cobol, _tal, and _unspecified. Use
_tal to denote the pTAL language on both TNS/E and TNS/R systems.
Considerations for the TNS Compilers Only
•
TNS C and C++ support mixed-language programs with modules written in C,
C++, TNS COBOL, FORTRAN, D-series Pascal, and TAL. Therefore, these
language specifiers apply: _c, _cobol, _fortran, _pascal, _tal, and
_unspecified.
•
If you declare an external procedure as _unspecified, the actual procedure
cannot be both written in C and compiled using the OLDCALLS pragma.
•
If you declare an external procedure as _unspecified and that procedure is
actually written in C, in the definition, the name must not contain lowercase
alphabetic characters.
Note. The attribute specifier is an outdated syntax for mixed-language programming and is
maintained only for compatibility. To declare external routines written in another language, you
should use the FUNCTION pragma syntax as described in FUNCTION
on page 13-35.
attribute-specifier:
[ language-specifier ] [ attribute [ attribute ]... ]
language-specifier is one of:
_c | _cobol | _fortran | _pascal | _tal | _unspecified
attribute is one of:
_alias ( "external-name " ) |
_extensible [ ( param-count ) ]
_resident | _variable