/* vmstk.c - the arithmetic stack of a virtual machine.
*
* Module begun 2008-02-21 by Rainer Gerhards
*
* Copyright 2008 Rainer Gerhards and Adiscon GmbH.
*
* This file is part of rsyslog.
*
* Rsyslog is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Rsyslog is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Rsyslog. If not, see .
*
* A copy of the GPL can be found in the file "COPYING" in this distribution.
*/
#include "config.h"
#include
#include
#include "rsyslog.h"
#include "obj.h"
#include "vmstk.h"
/* static data */
DEFobjStaticHelpers
DEFobjCurrIf(var)
/* Standard-Constructor
*/
BEGINobjConstruct(vmstk) /* be sure to specify the object type also in END macro! */
ENDobjConstruct(vmstk)
/* ConstructionFinalizer
* rgerhards, 2008-01-09
*/
static rsRetVal
vmstkConstructFinalize(vmstk_t __attribute__((unused)) *pThis)
{
DEFiRet;
ISOBJ_TYPE_assert(pThis, vmstk);
RETiRet;
}
/* destructor for the vmstk object */
BEGINobjDestruct(vmstk) /* be sure to specify the object type also in END and CODESTART macros! */
CODESTARTobjDestruct(vmstk)
ENDobjDestruct(vmstk)
/* debugprint for the vmstk object */
BEGINobjDebugPrint(vmstk) /* be sure to specify the object type also in END and CODESTART macros! */
CODESTARTobjDebugPrint(vmstk)
dbgoprint((obj_t*) pThis, "stack contents:\n");
ENDobjDebugPrint(vmstk)
/* push a value on the stack. The provided pVar is now owned
* by the stack. If the user intends to continue use it, it
* must be duplicated.
*/
static rsRetVal
push(vmstk_t *pThis, var_t *pVar)
{
DEFiRet;
ISOBJ_TYPE_assert(pThis, vmstk);
ISOBJ_TYPE_assert(pVar, var);
if(pThis->iStkPtr >= VMSTK_SIZE)
ABORT_FINALIZE(RS_RET_OUT_OF_STACKSPACE);
pThis->vStk[pThis->iStkPtr++] = pVar;
finalize_it:
RETiRet;
}
/* pop a value from the stack
* IMPORTANT: the stack pointer always points to the NEXT FREE entry. So in
* order to pop, we must access the element one below the stack pointer.
* The user is responsible for destructing the ppVar returned.
*/
static rsRetVal
pop(vmstk_t *pThis, var_t **ppVar)
{
DEFiRet;
ISOBJ_TYPE_assert(pThis, vmstk);
ASSERT(ppVar != NULL);
if(pThis->iStkPtr == 0)
ABORT_FINALIZE(RS_RET_STACK_EMPTY);
*ppVar = pThis->vStk[--pThis->iStkPtr];
finalize_it:
RETiRet;
}
/* pop a boolean value from the stack
* The user is responsible for destructing the ppVar returned.
*/
static rsRetVal
popBool(vmstk_t *pThis, var_t **ppVar)
{
DEFiRet;
/* assertions are done in pop(), we do not duplicate here */
CHKiRet(pop(pThis, ppVar));
CHKiRet(var.ConvToBool(*ppVar));
finalize_it:
RETiRet;
}
/* pop a number value from the stack
* The user is responsible for destructing the ppVar returned.
*/
static rsRetVal
popNumber(vmstk_t *pThis, var_t **ppVar)
{
DEFiRet;
/* assertions are done in pop(), we do not duplicate here */
CHKiRet(pop(pThis, ppVar));
CHKiRet(var.ConvToNumber(*ppVar));
finalize_it:
RETiRet;
}
/* pop a number value from the stack
* The user is responsible for destructing the ppVar returned.
*/
static rsRetVal
popString(vmstk_t *pThis, var_t **ppVar)
{
DEFiRet;
/* assertions are done in pop(), we do not duplicate here */
CHKiRet(pop(pThis, ppVar));
CHKiRet(var.ConvToString(*ppVar));
finalize_it:
RETiRet;
}
/* pop two variables for a common operation, e.g. a compare. When this
* functions returns, both variables have the same type, but the type
* is not set to anything specific.
* The user is responsible for destructing the ppVar's returned.
* A quick note on the name: it means pop 2 variable for a common
* opertion - just in case you wonder (I don't really like the name,
* but I didn't come up with a better one...).
* rgerhards, 2008-02-25
*/
static rsRetVal
pop2CommOp(vmstk_t *pThis, var_t **ppVar1, var_t **ppVar2)
{
DEFiRet;
/* assertions are done in pop(), we do not duplicate here */
/* operand two must be popped first, because it is at the top of stack */
CHKiRet(pop(pThis, ppVar2));
CHKiRet(pop(pThis, ppVar1));
CHKiRet(var.ConvForOperation(*ppVar1, *ppVar2));
finalize_it:
RETiRet;
}
/* queryInterface function
* rgerhards, 2008-02-21
*/
BEGINobjQueryInterface(vmstk)
CODESTARTobjQueryInterface(vmstk)
if(pIf->ifVersion != vmstkCURR_IF_VERSION) { /* check for current version, increment on each change */
ABORT_FINALIZE(RS_RET_INTERFACE_NOT_SUPPORTED);
}
/* ok, we have the right interface, so let's fill it
* Please note that we may also do some backwards-compatibility
* work here (if we can support an older interface version - that,
* of course, also affects the "if" above).
*/
//xxxpIf->oID = OBJvmstk;
pIf->Construct = vmstkConstruct;
pIf->ConstructFinalize = vmstkConstructFinalize;
pIf->Destruct = vmstkDestruct;
pIf->DebugPrint = vmstkDebugPrint;
pIf->Push = push;
pIf->Pop = pop;
pIf->PopBool = popBool;
pIf->PopNumber = popNumber;
pIf->PopString = popString;
pIf->Pop2CommOp = pop2CommOp;
finalize_it:
ENDobjQueryInterface(vmstk)
/* Initialize the vmstk class. Must be called as the very first method
* before anything else is called inside this class.
* rgerhards, 2008-02-19
*/
BEGINObjClassInit(vmstk, 1, OBJ_IS_CORE_MODULE) /* class, version */
/* request objects we use */
CHKiRet(objUse(var, CORE_COMPONENT));
/* set our own handlers */
OBJSetMethodHandler(objMethod_DEBUGPRINT, vmstkDebugPrint);
OBJSetMethodHandler(objMethod_CONSTRUCTION_FINALIZER, vmstkConstructFinalize);
ENDObjClassInit(vmstk)
/* vi:set ai:
*/