msgpsr.c

clips源代码

   /*******************************************************/
   /*      "C" Language Integrated Production System      */
   /*                                                     */
   /*               CLIPS Version 6.24  05/17/06          */
   /*                                                     */
   /*              MESSAGE-HANDLER PARSER FUNCTIONS       */
   /*******************************************************/

/*************************************************************/
/* Purpose:                                                  */
/*                                                           */
/* Principal Programmer(s):                                  */
/*      Brian L. Donnell                                     */
/*                                                           */
/* Contributing Programmer(s):                               */
/*                                                           */
/* Revision History:                                         */
/*      6.23: Changed name of variable exp to theExp         */
/*            because of Unix compiler warnings of shadowed  */
/*            definitions.                                   */
/*                                                           */
/*      6.24: Removed IMPERATIVE_MESSAGE_HANDLERS            */
/*                    compilation flag.                      */
/*                                                           */
/*            Renamed BOOLEAN macro type to intBool.         */
/*                                                           */
/*************************************************************/

/* =========================================
   *****************************************
               EXTERNAL DEFINITIONS
   =========================================
   ***************************************** */
#include "setup.h"

#if OBJECT_SYSTEM && (! BLOAD_ONLY) && (! RUN_TIME)

#include <string.h>

#if BLOAD || BLOAD_AND_BSAVE
#include "bload.h"
#endif

#include "classcom.h"
#include "classfun.h"
#include "memalloc.h"
#include "constrct.h"
#include "cstrcpsr.h"
#include "cstrnchk.h"
#include "envrnmnt.h"
#include "exprnpsr.h"
#include "insfun.h"
#include "msgcom.h"
#include "msgfun.h"
#include "pprint.h"
#include "prccode.h"
#include "router.h"
#include "scanner.h"
#include "strngrtr.h"

#define _MSGPSR_SOURCE_
#include "msgpsr.h"

/* =========================================
   *****************************************
                   CONSTANTS
   =========================================
   ***************************************** */
#define SELF_LEN         4
#define SELF_SLOT_REF   ':'

/* =========================================
   *****************************************
      INTERNALLY VISIBLE FUNCTION HEADERS
   =========================================
   ***************************************** */

static intBool IsParameterSlotReference(void *,char *);
static int SlotReferenceVar(void *,EXPRESSION *,void *);
static int BindSlotReference(void *,EXPRESSION *,void *);
static SLOT_DESC *CheckSlotReference(void *,DEFCLASS *,int,void *,intBool,EXPRESSION *);
static void GenHandlerSlotReference(void *,EXPRESSION *,unsigned short,SLOT_DESC *);

/* =========================================
   *****************************************
          EXTERNALLY VISIBLE FUNCTIONS
   =========================================
   ***************************************** */

/***********************************************************************
  NAME         : ParseDefmessageHandler
  DESCRIPTION  : Parses a message-handler for a class of objects
  INPUTS       : The logical name of the input source
  RETURNS      : FALSE if successful parse, TRUE otherwise
  SIDE EFFECTS : Handler allocated and inserted into class
  NOTES        : H/L Syntax:

                 (defmessage-handler <class> <name> [<type>] [<comment>]
                    (<params>)
                    <action>*)

                 <params> ::= <var>* | <var>* $?<name>
 ***********************************************************************/
globle int ParseDefmessageHandler(
  void *theEnv,
  char *readSource)
  {
   DEFCLASS *cls;
   SYMBOL_HN *cname,*mname,*wildcard;
   unsigned mtype = MPRIMARY;
   int min,max,error,lvars;
   EXPRESSION *hndParams,*actions;
   HANDLER *hnd;

   SetPPBufferStatus(theEnv,ON);
   FlushPPBuffer(theEnv);
   SetIndentDepth(theEnv,3);
   SavePPBuffer(theEnv,"(defmessage-handler ");

#if BLOAD || BLOAD_AND_BSAVE
   if ((Bloaded(theEnv)) && (! ConstructData(theEnv)->CheckSyntaxMode))
     {
      CannotLoadWithBloadMessage(theEnv,"defmessage-handler");
      return(TRUE);
     }
#endif
   cname = GetConstructNameAndComment(theEnv,readSource,&DefclassData(theEnv)->ObjectParseToken,"defmessage-handler",
                                      NULL,NULL,"~",TRUE,FALSE,TRUE);
   if (cname == NULL)
     return(TRUE);
   cls = LookupDefclassByMdlOrScope(theEnv,ValueToString(cname));
   if (cls == NULL)
     {
      PrintErrorID(theEnv,"MSGPSR",1,FALSE);
      EnvPrintRouter(theEnv,WERROR,"A class must be defined before its message-handlers.\n");
      return(TRUE);
     }
   if ((cls == DefclassData(theEnv)->PrimitiveClassMap[INSTANCE_NAME]) ||
       (cls == DefclassData(theEnv)->PrimitiveClassMap[INSTANCE_ADDRESS]) ||
       (cls == DefclassData(theEnv)->PrimitiveClassMap[INSTANCE_NAME]->directSuperclasses.classArray[0]))
     {
      PrintErrorID(theEnv,"MSGPSR",8,FALSE);
      EnvPrintRouter(theEnv,WERROR,"Message-handlers cannot be attached to the class ");
      EnvPrintRouter(theEnv,WERROR,EnvGetDefclassName(theEnv,(void *) cls));
      EnvPrintRouter(theEnv,WERROR,".\n");
      return(TRUE);
     }
   if (HandlersExecuting(cls))
     {
      PrintErrorID(theEnv,"MSGPSR",2,FALSE);
      EnvPrintRouter(theEnv,WERROR,"Cannot (re)define message-handlers during execution of \n");
      EnvPrintRouter(theEnv,WERROR,"  other message-handlers for the same class.\n");
      return(TRUE);
     }
   if (GetType(DefclassData(theEnv)->ObjectParseToken) != SYMBOL)
     {
      SyntaxErrorMessage(theEnv,"defmessage-handler");
      return(TRUE);
     }
   PPBackup(theEnv);
   PPBackup(theEnv);
   SavePPBuffer(theEnv," ");
   SavePPBuffer(theEnv,DefclassData(theEnv)->ObjectParseToken.printForm);
   SavePPBuffer(theEnv," ");
   mname = (SYMBOL_HN *) GetValue(DefclassData(theEnv)->ObjectParseToken);
   GetToken(theEnv,readSource,&DefclassData(theEnv)->ObjectParseToken);
   if (GetType(DefclassData(theEnv)->ObjectParseToken) != LPAREN)
     {
      SavePPBuffer(theEnv," ");
      if (GetType(DefclassData(theEnv)->ObjectParseToken) != STRING)
        {
         if (GetType(DefclassData(theEnv)->ObjectParseToken) != SYMBOL)
           {
            SyntaxErrorMessage(theEnv,"defmessage-handler");
            return(TRUE);
           }
         mtype = HandlerType(theEnv,"defmessage-handler",DOToString(DefclassData(theEnv)->ObjectParseToken));
         if (mtype == MERROR)
           return(TRUE);

         GetToken(theEnv,readSource,&DefclassData(theEnv)->ObjectParseToken);
         if (GetType(DefclassData(theEnv)->ObjectParseToken) == STRING)
           {
            SavePPBuffer(theEnv," ");
            GetToken(theEnv,readSource,&DefclassData(theEnv)->ObjectParseToken);
           }
        }
      else
        {
         SavePPBuffer(theEnv," ");
         GetToken(theEnv,readSource,&DefclassData(theEnv)->ObjectParseToken);
        }
     }
   PPBackup(theEnv);
   PPBackup(theEnv);
   PPCRAndIndent(theEnv);
   SavePPBuffer(theEnv,DefclassData(theEnv)->ObjectParseToken.printForm);

   hnd = FindHandlerByAddress(cls,mname,mtype);
   if (GetPrintWhileLoading(theEnv) && GetCompilationsWatch(theEnv))
     {
      EnvPrintRouter(theEnv,WDIALOG,"   Handler ");
      EnvPrintRouter(theEnv,WDIALOG,ValueToString(mname));
      EnvPrintRouter(theEnv,WDIALOG," ");
      EnvPrintRouter(theEnv,WDIALOG,MessageHandlerData(theEnv)->hndquals[mtype]);
      EnvPrintRouter(theEnv,WDIALOG,(char *) ((hnd == NULL) ? " defined.\n" : " redefined.\n"));
     }

   if ((hnd != NULL) ? hnd->system : FALSE)
     {
      PrintErrorID(theEnv,"MSGPSR",3,FALSE);
      EnvPrintRouter(theEnv,WERROR,"System message-handlers may not be modified.\n");
      return(TRUE);
     }

   hndParams = GenConstant(theEnv,SYMBOL,(void *) MessageHandlerData(theEnv)->SELF_SYMBOL);
   hndParams = ParseProcParameters(theEnv,readSource,&DefclassData(theEnv)->ObjectParseToken,hndParams,
                                    &wildcard,&min,&max,&error,IsParameterSlotReference);
   if (error)
     return(TRUE);
   PPCRAndIndent(theEnv);
   ExpressionData(theEnv)->ReturnContext = TRUE;
   actions = ParseProcActions(theEnv,"message-handler",readSource,
                              &DefclassData(theEnv)->ObjectParseToken,hndParams,wildcard,
                              SlotReferenceVar,BindSlotReference,&lvars,
                              (void *) cls);
   if (actions == NULL)
     {
      ReturnExpression(theEnv,hndParams);
      return(TRUE);
     }
   if (GetType(DefclassData(theEnv)->ObjectParseToken) != RPAREN)
     {
      SyntaxErrorMessage(theEnv,"defmessage-handler");
      ReturnExpression(theEnv,hndParams);
      ReturnPackedExpression(theEnv,actions);
      return(TRUE);
     }
   PPBackup(theEnv);
   PPBackup(theEnv);
   SavePPBuffer(theEnv,DefclassData(theEnv)->ObjectParseToken.printForm);
   SavePPBuffer(theEnv,"\n");

   /* ===================================================
      If we're only checking syntax, don't add the
      successfully parsed defmessage-handler to the KB.
      =================================================== */

   if (ConstructData(theEnv)->CheckSyntaxMode)
     {
      ReturnExpression(theEnv,hndParams);
      ReturnPackedExpression(theEnv,actions);
      return(FALSE);
     }

   if (hnd != NULL)
     {
      ExpressionDeinstall(theEnv,hnd->actions);
      ReturnPackedExpression(theEnv,hnd->actions);
      if (hnd->ppForm != NULL)
        rm(theEnv,(void *) hnd->ppForm,
           (sizeof(char) * (strlen(hnd->ppForm)+1)));
     }
   else
     {
      hnd = InsertHandlerHeader(theEnv,cls,mname,(int) mtype);
      IncrementSymbolCount(hnd->name);
     }
   ReturnExpression(theEnv,hndParams);

   hnd->minParams = min;
   hnd->maxParams = max;
   hnd->localVarCount = lvars;
   hnd->actions = actions;
   ExpressionInstall(theEnv,hnd->actions);
#if DEBUGGING_FUNCTIONS

   /* ===================================================
      Old handler trace status is automatically preserved
      =================================================== */
   if (EnvGetConserveMemory(theEnv) == FALSE)
     hnd->ppForm = CopyPPBuffer(theEnv);
   else
#endif
     hnd->ppForm = NULL;
   return(FALSE);
  }

/*******************************************************************************
  NAME         : CreateGetAndPutHandlers
  DESCRIPTION  : Creates two message-handlers with
                  the following syntax for the slot:

                 (defmessage-handler <class> get-<slot-name> primary ()
                    ?self:<slot-name>)

                 For single-field slots:

                 (defmessage-handler <class> put-<slot-name> primary (?value)
                    (bind ?self:<slot-name> ?value))

                 For multifield slots:

                 (defmessage-handler <class> put-<slot-name> primary ($?value)
                    (bind ?self:<slot-name> ?value))

  INPUTS       : The class slot descriptor
  RETURNS      : Nothing useful
  SIDE EFFECTS : Message-handlers created
  NOTES        : A put handler is not created for read-only slots
 *******************************************************************************/
globle void CreateGetAndPutHandlers(
  void *theEnv,
  SLOT_DESC *sd)
  {
   char *className,*slotName;
   size_t bufsz;
   char *buf,*handlerRouter = "*** Default Public Handlers ***";
   int oldPWL,oldCM;
   char *oldRouter;
   char *oldString;
   long oldIndex;

   if ((sd->createReadAccessor == 0) && (sd->createWriteAccessor == 0))
     return;
   className = ValueToString(sd->cls->header.name);
   slotName = ValueToString(sd->slotName->name);

   bufsz = (sizeof(char) * (strlen(className) + (strlen(slotName) * 2) + 80));
   buf = (char *) gm2(theEnv,bufsz);

   oldPWL = GetPrintWhileLoading(theEnv);
   SetPrintWhileLoading(theEnv,FALSE);
   oldCM = EnvSetConserveMemory(theEnv,TRUE);

   if (sd->createReadAccessor)
     {
      gensprintf(buf,"%s get-%s () ?self:%s)",className,slotName,slotName);
      
      oldRouter = RouterData(theEnv)->FastCharGetRouter;