fis-gtm/sr_i386/make_cimode.c

82 lines
3.4 KiB
C

/****************************************************************
* *
* Copyright 2001, 2009 Fidelity Information Services, Inc *
* *
* This source code contains the intellectual property *
* of its copyright holder(s), and is made available *
* under a license. If you do not know the terms of *
* the license, please stop and do not read further. *
* *
****************************************************************/
#include "mdef.h"
#include "gtm_string.h"
#include "error.h"
#include "rtnhdr.h"
#include "op.h"
#include "i386.h"
#include "inst_flush.h"
#include "gtmci.h"
#include "gtm_text_alloc.h"
#define CALL_SIZE 5
#define CODE_SIZE (3 * CALL_SIZE)
#define CODE_LINES 3
/* The code created and returned by make_cimode() is executed in the frame GTM$CI at level 1 of
* every nested call-in environment. For every M routine being called-in from C, GTM$CI code
* will setup argument registers/stack and executes the M routine. When the M routine returns
* from its final QUIT, GTM$CI returns to gtm_ci(). make_cimode generates machine equivalents
* for the following operations in that order:
*
* CALL ci_restart :setup register/stack arguments from 'param_list' and transfer control
* to op_extcall/op_extexfun which return only after the M routine finishes and QUITs.
* CALL ci_ret_code :transfer control from the M routine back to C (gtm_ci). Never returns.
* CALL opp_ret :an implicit QUIT although it is never executed.
*
* Before GTM$CI executes, it is assumed that the global 'param_list' has been populated with
* argument/return mval*.
*/
rhdtyp *make_cimode(void)
{
static rhdtyp *base_address = NULL;
lab_tabent *lbl;
int *lnr;
unsigned char *code;
if (NULL != base_address)
return base_address;
base_address = (rhdtyp *)GTM_TEXT_ALLOC(SIZEOF(rhdtyp) + CODE_SIZE + SIZEOF(lab_tabent) + CODE_LINES * SIZEOF(int4));
memset(base_address,0,SIZEOF(rhdtyp) + CODE_SIZE + SIZEOF(lab_tabent) + CODE_LINES * SIZEOF(int4));
base_address->routine_name.len = STR_LIT_LEN(GTM_CIMOD);
base_address->routine_name.addr = GTM_CIMOD;
base_address->ptext_ptr = SIZEOF(rhdtyp);
base_address->vartab_ptr =
base_address->labtab_ptr = SIZEOF(rhdtyp) + CODE_SIZE; /* hdr + code */
base_address->lnrtab_ptr = SIZEOF(rhdtyp) + CODE_SIZE + SIZEOF(lab_tabent);
base_address->labtab_len = 1;
base_address->lnrtab_len = CODE_LINES;
code = (unsigned char *) base_address + base_address->ptext_ptr;
*code++ = I386_INS_CALL_Jv;
*((int4 *)code) = (int4)((unsigned char *)ci_restart - (code + SIZEOF(int4)));
code += SIZEOF(int4);
*code++ = I386_INS_CALL_Jv; /* a CALL to return control from M to ci_ret_code() which in turn returns to gtm_ci() */
*((int4 *)code) = (int4)((unsigned char *)ci_ret_code - (code + SIZEOF(int4)));
code += SIZEOF(int4);
*code++ = I386_INS_JMP_Jv;
*((int4 *)code) = (int4)((unsigned char *)opp_ret - (code + SIZEOF(int4)));
code += SIZEOF(int4);
lbl = (lab_tabent *)((int) base_address + base_address->labtab_ptr);
lbl->lab_ln_ptr = base_address->lnrtab_ptr;
lnr = (int *)((int)base_address + base_address->lnrtab_ptr);
*lnr++ = base_address->ptext_ptr;
*lnr++ = base_address->ptext_ptr;
*lnr++ = base_address->ptext_ptr + 2 * CALL_SIZE;
assert(code - ((unsigned char *)base_address + base_address->ptext_ptr) == CODE_SIZE);
zlput_rname(base_address);
inst_flush(base_address, SIZEOF(rhdtyp) + CODE_SIZE + SIZEOF(lab_tabent) + CODE_LINES * SIZEOF(int4));
return base_address;
}