macroprocessor: stop with error when division by zero is encountered. closes #1278

macro/MacroBison.yy

 /*
- * Copyright (C) 2008-2014 Dynare Team
+ * Copyright (C) 2008-2016 Dynare Team
  *
  * This file is part of Dynare.
  *
@@ -150,7 +150,12 @@ expr : INTEGER
      | expr TIMES expr
        { TYPERR_CATCH($$ = *$1 * *$3, @$); }
      | expr DIVIDE expr
-       { TYPERR_CATCH($$ = *$1 / *$3, @$); }
+       {
+         if (dynamic_cast<const IntMV *>($3) != NULL
+             && ((IntMV *)$3)->get_int_value() == 0)
+           driver.error(@$, "Division by zero");
+         TYPERR_CATCH($$ = *$1 / *$3, @$);
+       }
      | expr LESS expr
        { TYPERR_CATCH($$ = *$1 < *$3, @$); }
      | expr GREATER expr

macro/MacroValue.hh

 /*
- * Copyright (C) 2008-2013 Dynare Team
+ * Copyright (C) 2008-2016 Dynare Team
  *
  * This file is part of Dynare.
  *
@@ -158,6 +158,7 @@ public:
     If mv2 < mv1, returns an empty range (for consistency with MATLAB).
   */
   static const MacroValue *new_range(MacroDriver &driver, const MacroValue *mv1, const MacroValue *mv2) throw (TypeError);
+  inline int get_int_value() const { return value; };
 };
 
 //! Represents a string value in macro language