http://publib.boulder.ibm.com/infocente ... 26_3_7_2_4
Using the pre-initialization service CEEPIPI to call a small C++ program. The example as shown worked fine.
Next I tried to pass a parameter using the parm_ptr of the call_sub function
parm_ptr (input)
A parameter list pointer or 0 (zero) that is placed in register
1 when the routine is executed.
C and C++ users need
to follow the subroutine linkage convention for C/C++ — assembler
ILC applications, as described in z/OS XL C/C++ Programming Guide.
Here is the parameter list I am passing
ADDR_BLK DC A(FMTSTR) parameter address block with..
DC A(X'80000000'+INTVAL) ..high bit on the last address
FMTSTR DC C'Sample formatting string'
DC C' which includes an int -- %d --'
DC AL1(NEWLINE,NEWLINE)
DC C'and two newline characters'
DC AL1(NULL)
*
INTVAL DC F'222' The integer value displayed
*
NULL EQU X'00' C NULL character
NEWLINE EQU X'15' C \n character
DC A(X'80000000'+INTVAL) ..high bit on the last address
FMTSTR DC C'Sample formatting string'
DC C' which includes an int -- %d --'
DC AL1(NEWLINE,NEWLINE)
DC C'and two newline characters'
DC AL1(NULL)
*
INTVAL DC F'222' The integer value displayed
*
NULL EQU X'00' C NULL character
NEWLINE EQU X'15' C \n character
I followed the linkage instructions for a C++ program
I used compiler option PLIST(OS)
I made the C++ function export "OS"
Here is my C++ code
#pragma linkage(HLLPIPI, FETCHABLE)
extern "OS" {
int HLLPIPI ()
{
printf ( "C subroutine beginning\n" );
printf ( "Called using LE PreInit call\n" );
printf ( "Subroutine interface.\n" );
printf ( "C subroutine returns to caller\n" );
printf ( "Parameter is %d\n", (int)__R1 );
printf ( "Parameter is %p\n", __osplist[0] );
return 0;
}
}
extern "OS" {
int HLLPIPI ()
{
printf ( "C subroutine beginning\n" );
printf ( "Called using LE PreInit call\n" );
printf ( "Subroutine interface.\n" );
printf ( "C subroutine returns to caller\n" );
printf ( "Parameter is %d\n", (int)__R1 );
printf ( "Parameter is %p\n", __osplist[0] );
return 0;
}
}
When I tried to run I always get 0 for the value of R1 where I am expecting a pointer to my paramter list. Has anyone else tried this and has success. Can you see what I am missing?
Code'd
