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-rw-r--r--runtime/vm.c252
1 files changed, 239 insertions, 13 deletions
diff --git a/runtime/vm.c b/runtime/vm.c
index 23adea8b..125b0d21 100644
--- a/runtime/vm.c
+++ b/runtime/vm.c
@@ -27,6 +27,7 @@
#include <stdlib.h>
#include <string.h>
#include <assert.h>
+#include <ctype.h>
#include "rsyslog.h"
#include "obj.h"
@@ -40,6 +41,142 @@ DEFobjCurrIf(vmstk)
DEFobjCurrIf(var)
DEFobjCurrIf(sysvar)
+/* ------------------------------ function registry code and structures ------------------------------ */
+
+/* we maintain a registry of known functions */
+/* currently, this is a singly-linked list, this shall become a binary
+ * tree when we add the real call interface. So far, entries are added
+ * at the root, only.
+ */
+typedef struct s_rsf_entry {
+ cstr_t *pName; /* function name */
+ prsf_t rsf; /* pointer to function code */
+ struct s_rsf_entry *pNext; /* Pointer to next element or NULL */
+} rsf_entry_t;
+rsf_entry_t *funcRegRoot = NULL;
+
+
+/* add a function to the function registry.
+ * The handed-over cstr_t* object must no longer be used by the caller.
+ * A duplicate function name is an error.
+ * rgerhards, 2009-04-06
+ */
+static rsRetVal
+rsfrAddFunction(uchar *szName, prsf_t rsf)
+{
+ rsf_entry_t *pEntry;
+ size_t lenName;
+ DEFiRet;
+
+ assert(szName != NULL);
+ assert(rsf != NULL);
+
+ /* first check if we have a duplicate name, with the current approach this means
+ * we need to go through the whole list.
+ */
+ lenName = strlen((char*)szName);
+ for(pEntry = funcRegRoot ; pEntry != NULL ; pEntry = pEntry->pNext)
+ if(!rsCStrSzStrCmp(pEntry->pName, szName, lenName))
+ ABORT_FINALIZE(RS_RET_DUP_FUNC_NAME);
+
+ /* unique name, so add to head of list */
+ CHKmalloc(pEntry = calloc(1, sizeof(rsf_entry_t)));
+ CHKiRet(rsCStrConstructFromszStr(&pEntry->pName, szName));
+ pEntry->rsf = rsf;
+ pEntry->pNext = funcRegRoot;
+ funcRegRoot = pEntry;
+
+finalize_it:
+ RETiRet;
+}
+
+
+/* find a function inside the function registry
+ * The caller provides a cstr_t with the function name and receives
+ * a function pointer back. If no function is found, an RS_RET_UNKNW_FUNC
+ * error is returned. So if the function returns with RS_RET_OK, the caller
+ * can savely assume the function pointer is valid.
+ * rgerhards, 2009-04-06
+ */
+static rsRetVal
+findRSFunction(cstr_t *pcsName, prsf_t *prsf)
+{
+ rsf_entry_t *pEntry;
+ rsf_entry_t *pFound;
+ DEFiRet;
+
+ assert(prsf != NULL);
+
+ /* find function by list walkthrough. */
+ pFound = NULL;
+ for(pEntry = funcRegRoot ; pEntry != NULL && pFound == NULL ; pEntry = pEntry->pNext)
+ if(!rsCStrCStrCmp(pEntry->pName, pcsName))
+ pFound = pEntry;
+
+ if(pFound == NULL)
+ ABORT_FINALIZE(RS_RET_UNKNW_FUNC);
+
+ *prsf = pFound->rsf;
+
+finalize_it:
+ RETiRet;
+}
+
+
+/* find the name of a RainerScript function whom's function pointer
+ * is known. This function returns the cstr_t object, which MUST NOT
+ * be modified by the caller.
+ * rgerhards, 2009-04-06
+ */
+static rsRetVal
+findRSFunctionName(prsf_t rsf, cstr_t **ppcsName)
+{
+ rsf_entry_t *pEntry;
+ rsf_entry_t *pFound;
+ DEFiRet;
+
+ assert(rsf != NULL);
+ assert(ppcsName != NULL);
+
+ /* find function by list walkthrough. */
+ pFound = NULL;
+ for(pEntry = funcRegRoot ; pEntry != NULL && pFound == NULL ; pEntry = pEntry->pNext)
+ if(pEntry->rsf == rsf)
+ pFound = pEntry;
+
+ if(pFound == NULL)
+ ABORT_FINALIZE(RS_RET_UNKNW_FUNC);
+
+ *ppcsName = pFound->pName;
+
+finalize_it:
+ RETiRet;
+}
+
+
+/* free the whole function registry
+ */
+static void
+rsfrRemoveAll(void)
+{
+ rsf_entry_t *pEntry;
+ rsf_entry_t *pEntryDel;
+
+ BEGINfunc
+ pEntry = funcRegRoot;
+ while(pEntry != NULL) {
+ pEntryDel = pEntry;
+ pEntry = pEntry->pNext;
+ rsCStrDestruct(&pEntryDel->pName);
+ free(pEntryDel);
+ }
+ funcRegRoot = NULL;
+ ENDfunc
+}
+
+
+/* ------------------------------ end function registry code and structures ------------------------------ */
+
/* ------------------------------ instruction set implementation ------------------------------ *
* The following functions implement the VM's instruction set.
@@ -331,7 +468,6 @@ CODESTARTop(PUSHSYSVAR)
finalize_it:
ENDop(PUSHSYSVAR)
-
/* The function call operation is only very roughly implemented. While the plumbing
* to reach this instruction is fine, the instruction itself currently supports only
* functions with a single argument AND with a name that we know.
@@ -341,20 +477,9 @@ ENDop(PUSHSYSVAR)
*/
BEGINop(FUNC_CALL) /* remember to set the instruction also in the ENDop macro! */
var_t *numOperands;
- var_t *operand1;
- int iStrlen;
CODESTARTop(FUNC_CALL)
vmstk.PopNumber(pThis->pStk, &numOperands);
- if(numOperands->val.num != 1)
- ABORT_FINALIZE(RS_RET_INVLD_NBR_ARGUMENTS);
- vmstk.PopString(pThis->pStk, &operand1); /* guess there's just one ;) */
- if(!rsCStrSzStrCmp(pOp->operand.pVar->val.pStr, (uchar*) "strlen", 6)) { /* only one supported so far ;) */
-RUNLOG_VAR("%s", rsCStrGetSzStr(operand1->val.pStr));
- iStrlen = strlen((char*) rsCStrGetSzStr(operand1->val.pStr));
-RUNLOG_VAR("%d", iStrlen);
- } else
- ABORT_FINALIZE(RS_RET_INVLD_FUNC);
- PUSHRESULTop(operand1, iStrlen); // TODO: dummy, FIXME
+ CHKiRet((*pOp->operand.rsf)(pThis->pStk, numOperands->val.num));
var.Destruct(&numOperands); /* no longer needed */
finalize_it:
ENDop(FUNC_CALL)
@@ -363,6 +488,89 @@ ENDop(FUNC_CALL)
/* ------------------------------ end instruction set implementation ------------------------------ */
+/* ------------------------------ begin built-in function implementation ------------------------------ */
+/* note: this shall probably be moved to a separate module, but for the time being we do it directly
+ * in here. This is on our way to get from a dirty to a clean solution via baby steps that are
+ * a bit less dirty each time...
+ *
+ * The advantage of doing it here is that we do not yet need to think about how to handle the
+ * exit case, where we must not unload function modules which functions are still referenced.
+ *
+ * CALLING INTERFACE:
+ * The function must pop its parameters off the stack and pop its result onto
+ * the stack when it is finished. The number of parameters the function was
+ * called with is provided to it. If the argument count is less then what the function
+ * expected, it may handle the situation with defaults (or return an error). If the
+ * argument count is greater than expected, returnung an error is highly
+ * recommended (use RS_RET_INVLD_NBR_ARGUMENTS for these cases).
+ *
+ * All function names are prefixed with "rsf_" (RainerScript Function) to have
+ * a separate "name space".
+ *
+ * rgerhards, 2009-04-06
+ */
+
+
+/* The strlen function, also probably a prototype of how all functions should be
+ * implemented.
+ * rgerhards, 2009-04-06
+ */
+static rsRetVal
+rsf_strlen(vmstk_t *pStk, int numOperands)
+{
+ DEFiRet;
+ var_t *operand1;
+ int iStrlen;
+
+ if(numOperands != 1)
+ ABORT_FINALIZE(RS_RET_INVLD_NBR_ARGUMENTS);
+
+ /* pop args and do operaton (trivial case here...) */
+ vmstk.PopString(pStk, &operand1);
+ iStrlen = strlen((char*) rsCStrGetSzStr(operand1->val.pStr));
+
+ /* Store result and cleanup */
+ var.SetNumber(operand1, iStrlen);
+ vmstk.Push(pStk, operand1);
+finalize_it:
+ RETiRet;
+}
+
+
+/* The "tolower" function, which converts its sole argument to lower case.
+ * Quite honestly, currently this is primarily a test driver for me...
+ * rgerhards, 2009-04-06
+ */
+static rsRetVal
+rsf_tolower(vmstk_t *pStk, int numOperands)
+{
+ DEFiRet;
+ var_t *operand1;
+ uchar *pSrc;
+ cstr_t *pcstr;
+ int iStrlen;
+
+ if(numOperands != 1)
+ ABORT_FINALIZE(RS_RET_INVLD_NBR_ARGUMENTS);
+
+ /* pop args and do operaton */
+ CHKiRet(rsCStrConstruct(&pcstr));
+ vmstk.PopString(pStk, &operand1);
+ pSrc = rsCStrGetSzStr(operand1->val.pStr);
+ iStrlen = strlen((char*)pSrc);
+ while(iStrlen--) {
+ CHKiRet(rsCStrAppendChar(pcstr, tolower(*pSrc++)));
+ }
+
+ /* Store result and cleanup */
+ CHKiRet(rsCStrFinish(pcstr));
+ var.SetString(operand1, pcstr);
+ vmstk.Push(pStk, operand1);
+finalize_it:
+ RETiRet;
+}
+
+
/* Standard-Constructor
*/
BEGINobjConstruct(vm) /* be sure to specify the object type also in END macro! */
@@ -532,10 +740,23 @@ CODESTARTobjQueryInterface(vm)
pIf->PopBoolFromStack = PopBoolFromStack;
pIf->PopVarFromStack = PopVarFromStack;
pIf->SetMsg = SetMsg;
+ pIf->FindRSFunction = findRSFunction;
+ pIf->FindRSFunctionName = findRSFunctionName;
finalize_it:
ENDobjQueryInterface(vm)
+/* Exit the vm class.
+ * rgerhards, 2009-04-06
+ */
+BEGINObjClassExit(vm, OBJ_IS_CORE_MODULE) /* class, version */
+ rsfrRemoveAll();
+ objRelease(sysvar, CORE_COMPONENT);
+ objRelease(var, CORE_COMPONENT);
+ objRelease(vmstk, CORE_COMPONENT);
+ENDObjClassExit(vm)
+
+
/* Initialize the vm class. Must be called as the very first method
* before anything else is called inside this class.
* rgerhards, 2008-02-19
@@ -549,6 +770,11 @@ BEGINObjClassInit(vm, 1, OBJ_IS_CORE_MODULE) /* class, version */
/* set our own handlers */
OBJSetMethodHandler(objMethod_DEBUGPRINT, vmDebugPrint);
OBJSetMethodHandler(objMethod_CONSTRUCTION_FINALIZER, vmConstructFinalize);
+
+ /* register built-in functions // TODO: move to its own module */
+ CHKiRet(rsfrAddFunction((uchar*)"strlen", rsf_strlen));
+ CHKiRet(rsfrAddFunction((uchar*)"tolower", rsf_tolower));
+
ENDObjClassInit(vm)
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