diff options
Diffstat (limited to 'vmstk.c')
| -rw-r--r-- | vmstk.c | 233 |
1 files changed, 233 insertions, 0 deletions
diff --git a/vmstk.c b/vmstk.c new file mode 100644 index 00000000..f6614f71 --- /dev/null +++ b/vmstk.c @@ -0,0 +1,233 @@ +/* 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 <http://www.gnu.org/licenses/>. + * + * A copy of the GPL can be found in the file "COPYING" in this distribution. + */ + +#include "config.h" +#include <stdlib.h> +#include <assert.h> + +#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). + */ + 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: + */ |