analysis.c

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   /*========================================================*/
   /* Return FALSE to indicate that no errors were detected. */
   /*========================================================*/

   return(FALSE);
  }

/*************************************************************/
/* UnboundVariablesInPattern: Verifies that variables within */
/*   a slot/field have been referenced properly (i.e. that   */
/*   variables have been previously bound if they are not a  */
/*   binding occurrence).                                    */
/*************************************************************/
static intBool UnboundVariablesInPattern(
  void *theEnv,
  struct lhsParseNode *theSlot,
  int pattern)
  {
   struct lhsParseNode *andField;
   struct lhsParseNode *rv;
   int result;
   struct lhsParseNode *orField;
   struct symbolHashNode *slotName;
   CONSTRAINT_RECORD *theConstraints;
   int theField;

   /*===================================================*/
   /* If a multifield slot is being checked, then check */
   /* each of the fields grouped with the multifield.   */
   /*===================================================*/

   if (theSlot->multifieldSlot)
     {
      theSlot = theSlot->bottom;
      while (theSlot != NULL)
        {
         if (UnboundVariablesInPattern(theEnv,theSlot,pattern))
           { return(TRUE); }
         theSlot = theSlot->right;
        }

      return(FALSE);
     }

   /*=======================*/
   /* Check a single field. */
   /*=======================*/

   slotName = theSlot->slot;
   theField = theSlot->index;
   theConstraints = theSlot->constraints;

   /*===========================================*/
   /* Loop through each of the '|' constraints. */
   /*===========================================*/

   for (orField = theSlot->bottom;
        orField != NULL;
        orField = orField->bottom)
     {
      /*===========================================*/
      /* Loop through each of the fields connected */
      /* by the '&' within the '|' constraint.     */
      /*===========================================*/

      for (andField = orField;
           andField != NULL;
           andField = andField->right)
        {
         /*=======================================================*/
         /* If this is not a binding occurence of a variable and  */
         /* there is no previous binding occurence of a variable, */
         /* then generate an error message for a variable that is */
         /* referred to but not bound.                            */
         /*=======================================================*/

         if (((andField->type == SF_VARIABLE) || (andField->type == MF_VARIABLE)) &&
             (andField->referringNode == NULL))
           {
            VariableReferenceErrorMessage(theEnv,(SYMBOL_HN *) andField->value,NULL,pattern,
                                          slotName,theField);
            return(TRUE);
           }

         /*==============================================*/
         /* Check predicate and return value constraints */
         /* to insure that all variables used within the */
         /* constraint have been previously bound.       */
         /*==============================================*/

         else if ((andField->type == PREDICATE_CONSTRAINT) ||
                  (andField->type == RETURN_VALUE_CONSTRAINT))
           {
            rv = CheckExpression(theEnv,andField->expression,NULL,pattern,slotName,theField);
            if (rv != NULL) return(TRUE);
           }

         /*========================================================*/
         /* If static constraint checking is being performed, then */
         /* determine if constant values have violated the set of  */
         /* derived constraints for the slot/field (based on the   */
         /* deftemplate definition and propagated constraints).    */
         /*========================================================*/

         else if (((andField->type == INTEGER) || (andField->type == FLOAT) ||
                   (andField->type == SYMBOL) || (andField->type == STRING) ||
                   (andField->type == INSTANCE_NAME)) &&
                  EnvGetStaticConstraintChecking(theEnv))
           {
            result = ConstraintCheckValue(theEnv,andField->type,andField->value,theConstraints);
            if (result != NO_VIOLATION)
              {
               ConstraintViolationErrorMessage(theEnv,"A literal restriction value",
                                               NULL,FALSE,pattern,
                                               slotName,theField,result,
                                               theConstraints,TRUE);
               return(TRUE);
              }
           }
        }
     }

   /*===============================*/
   /* Return FALSE to indicate that */
   /* no errors were detected.      */
   /*===============================*/

   return(FALSE);
  }

/******************************************************************/
/* CheckExpression: Verifies that variables within an expression  */
/*   have been referenced properly. All variables within an       */
/*   expression must have been previously bound.                  */
/******************************************************************/
static struct lhsParseNode *CheckExpression(
  void *theEnv,
  struct lhsParseNode *exprPtr,
  struct lhsParseNode *lastOne,
  int whichCE,
  struct symbolHashNode *slotName,
  int theField)
  {
   struct lhsParseNode *rv;
   int i = 1;

   while (exprPtr != NULL)
     {
      /*===============================================================*/
      /* Check that single field variables contained in the expression */
      /* were previously defined in the LHS. Also check to see if the  */
      /* variable has unmatchable constraints.                         */
      /*===============================================================*/

      if (exprPtr->type == SF_VARIABLE)
        {
         if (exprPtr->referringNode == NULL)
           {
            VariableReferenceErrorMessage(theEnv,(SYMBOL_HN *) exprPtr->value,lastOne,
                                          whichCE,slotName,theField);
            return(exprPtr);
           }
         else if ((UnmatchableConstraint(exprPtr->constraints)) &&
                  EnvGetStaticConstraintChecking(theEnv))
           {
            ConstraintReferenceErrorMessage(theEnv,(SYMBOL_HN *) exprPtr->value,lastOne,i,
                                            whichCE,slotName,theField);
            return(exprPtr);
           }
        }

      /*==================================================*/
      /* Check that multifield variables contained in the */
      /* expression were previously defined in the LHS.   */
      /*==================================================*/

      else if ((exprPtr->type == MF_VARIABLE) && (exprPtr->referringNode == NULL))
        {
         VariableReferenceErrorMessage(theEnv,(SYMBOL_HN *) exprPtr->value,lastOne,
                                       whichCE,slotName,theField);
         return(exprPtr);
        }

      /*=====================================================*/
      /* Check that global variables are referenced properly */
      /* (i.e. if you reference a global variable, it must   */
      /* already be defined by a defglobal construct).       */
      /*=====================================================*/

#if DEFGLOBAL_CONSTRUCT
      else if (exprPtr->type == GBL_VARIABLE)
        {
         int count;

         if (FindImportedConstruct(theEnv,"defglobal",NULL,ValueToString(exprPtr->value),
                                   &count,TRUE,NULL) == NULL)
           {
            VariableReferenceErrorMessage(theEnv,(SYMBOL_HN *) exprPtr->value,lastOne,
                                          whichCE,slotName,theField);
            return(exprPtr);
           }
        }
#endif

      /*============================================*/
      /* Recursively check other function calls to  */
      /* insure variables are referenced correctly. */
      /*============================================*/

      else if (((exprPtr->type == FCALL)
#if DEFGENERIC_CONSTRUCT
             || (exprPtr->type == GCALL)
#endif
#if DEFFUNCTION_CONSTRUCT
             || (exprPtr->type == PCALL)
#endif
         ) && (exprPtr->bottom != NULL))
        {
         if ((rv = CheckExpression(theEnv,exprPtr->bottom,exprPtr,whichCE,slotName,theField)) != NULL)
           { return(rv); }
        }

      /*=============================================*/
      /* Move on to the next part of the expression. */
      /*=============================================*/

      i++;
      exprPtr = exprPtr->right;
     }

   /*================================================*/
   /* Return NULL to indicate no error was detected. */
   /*================================================*/

   return(NULL);
  }

/********************************************************/
/* VariableReferenceErrorMessage: Generic error message */
/*   for referencing a variable before it is defined.   */
/********************************************************/
static void VariableReferenceErrorMessage(
  void *theEnv,
  struct symbolHashNode *theVariable,
  struct lhsParseNode *theExpression,
  int whichCE,
  struct symbolHashNode *slotName,
  int theField)
  {
   struct expr *temprv;

   /*=============================*/
   /* Print the error message ID. */
   /*=============================*/

   PrintErrorID(theEnv,"ANALYSIS",4,TRUE);

   /*=================================*/
   /* Print the name of the variable. */
   /*=================================*/

   EnvPrintRouter(theEnv,WERROR,"Variable ?");
   EnvPrintRouter(theEnv,WERROR,ValueToString(theVariable));
   EnvPrintRouter(theEnv,WERROR," ");

   /*=================================================*/
   /* If the variable was found inside an expression, */
   /* then print the expression.                      */
   /*=================================================*/

   if (theExpression != NULL)
     {
      temprv = LHSParseNodesToExpression(theEnv,theExpression);
      ReturnExpression(theEnv,temprv->nextArg);
      temprv->nextArg = NULL;
      EnvPrintRouter(theEnv,WERROR,"found in the expression ");
      PrintExpression(theEnv,WERROR,temprv);
      EnvPrintRouter(theEnv,WERROR,"\n");
      ReturnExpression(theEnv,temprv);
     }

   /*====================================================*/
   /* Print the CE in which the variable was referenced. */
   /*====================================================*/

   EnvPrintRouter(theEnv,WERROR,"was referenced in CE #");
   PrintLongInteger(theEnv,WERROR,(long int) whichCE);

   /*=====================================*/
   /* Identify the slot or field in which */
   /* the variable was found.             */
   /*=====================================*/

   if (slotName == NULL)
     {
      if (theField > 0)
        {
         EnvPrintRouter(theEnv,WERROR," field #");
         PrintLongInteger(theEnv,WERROR,(long int) theField);
        }
     }
   else
     {
      EnvPrintRouter(theEnv,WERROR," slot ");
      EnvPrintRouter(theEnv,WERROR,ValueToString(slotName));
     }

   EnvPrintRouter(theEnv,WERROR," before being defined.\n");
  }

/************************************************************/
/* VariableMixingErrorMessage: Prints the error message for */
/*   the illegal mixing of single and multifield variables  */
/*   on the LHS of a rule.                                  */
/************************************************************/
static void VariableMixingErrorMessage(
  void *theEnv,
  struct symbolHashNode *theVariable)
  {
   PrintErrorID(theEnv,"ANALYSIS",3,TRUE);
   EnvPrintRouter(theEnv,WERROR,"Variable ?");
   EnvPrintRouter(theEnv,WERROR,ValueToString(theVariable));
   EnvPrintRouter(theEnv,WERROR," is used as both a single and multifield variable in the LHS\n");
  }

#endif /* (! RUN_TIME) && (! BLOAD_ONLY) && DEFRULE_CONSTRUCT */