Some C compilers require each function to be declared with an ANSI-style prototype that indicates the placement and datatype of each argument received by the function. Other compilers do not recognize ANSI-style prototypes.
The PROTOTYPE macro allows forward declarations that are agreeable to both ANSI and non-ANSI compilers. This macro is used in forward declarations of C functions as:
PROTOTYPE (( argument_list ));
where argument_list is the ANSI-style argument list. PROTOTYPE is conditionally defined. If the compiler supports ANSI-style prototypes, then PROTOTYPE echos the argument list into the compiled code. Otherwise, PROTOTYPE echos nothing.
The following example illustrates the use of PROTOTYPE:
extern CS_RETCODE CS_PUBLIC ex_clientmsg_cb PROTOTYPE((
CS_CONTEXT *context,
CS_CONNECTION *connection,
CS_CLIENTMSG *errmsg
));
CS_RETCODE CS_PUBLIC
ex_clientmsg_cb(context, connection, errmsg)
CS_CONTEXT *context;
CS_CONNECTION *connection;
CS_CLIENTMSG *errmsg;
{
... function body goes here ...
}
CS_PUBLIC is used in callback function prototypes to make sure that machine-specific declaration requirements are satisfied. See “Declare callbacks with CS_PUBLIC” for more information.
