System i: Programming i5/OS PASE - IBM

* data type that is passed as a by-value argument.
*/
typedef struct {
char filler[5];
} aggregate;
/*
* "result_type" and "signature" define the function
* result type and the sequence and type of all
* arguments needed for the ILE procedure identified
* by ILEtarget
*
* NOTE: The fact that this argument list contains
* fixed-point arguments shorter than 4 bytes or
* floating-point arguments shorter than 8 bytes
* implies that the target ILE C procedure is compiled
* with #pragma argument(ileProcedureName, nowiden)
*
* Without this pragma, standard C linkage for ILE
* requires 1-byte and 2-byte integer arguments to be
* widened to 4-bytes and requires 4-byte floating-point
* arguments to be widened to 8-bytes
*/
static result_type_t result_type = RESULT_INT32;
static arg_type_t signature[] =
{
ARG_INT32,
ARG_MEMPTR,
ARG_FLOAT64,
ARG_UINT8, /* requires #pragma nowiden in ILE code */
sizeof(aggregate),
ARG_INT16,
ARG_END
};
/*
* simple_wrapper accepts the same arguments and returns
* the same result as the ILE procedure it calls. This
* example does not require a customized or declared structure
* for the ILE argument list. This wrapper uses malloc
* to obtain storage. If an exception or signal occurs,
* the storage may not be freed. If your program needs
* to prevent such a storage leak, a signal handler
* must be built to handle it, or you can use the methods
* in best_wrapper.
*/
int simple_wrapper(int arg1, void *arg2, double arg3,
char arg4, aggregate arg5, short arg6)
{
int result;
/*
* xlc does not guarantee 16-byte alignment for
* automatic (stack) variables of any type, but
* PASE malloc() always returns 16-byte aligned storage.
* size_ILEarglist() determines how much storage is
* needed, based on entries in the signature array
*/
ILEarglist_base *ILEarglist;
ILEarglist = (ILEarglist_base*)malloc( size_ILEarglist(signature) );
/*
* build_ILEarglist() copies argument values into the ILE
* argument list buffer, based on entries in the signature
* array.
*/
build_ILEarglist(ILEarglist, &arg1, signature);
i5/OS PASE 33