fin de constant propag sans raffinement

tp2/Pystan/config/constant_propagation.py

@@ -100,15 +100,16 @@ class Constant_propagation(Transfer[state]):
         if s1 is None: return s2
         elif s2 is None: return s1
         else:
+            s=s1.copy()
             for var in s2:
                 if not(var in s1):
-                    s1[var]=s2[var]
+                    s[var]=s2[var]
                 elif s1[var] == abstract_value(None):
-                    s1[var]=s2[var]
+                    s[var]=s2[var]
                 elif s2[var] == abstract_value(None):
                     pass
                 else:
-                    s1[var]=abstract_value(None)
+                    s[var]=abstract_value(None)
         return s1
                       
         
@@ -124,29 +125,33 @@ class Constant_propagation(Transfer[state]):
             return included
 
     def tr_skip(self,s: state) -> state:
-        return s
+        return s.copy()
     
     def tr_set(self, s: state, v: str, e: ArithExpr) -> state:
-        s[v]=eval_aexp(s, e)
-        return s
+        s1 = s.copy()
+        s1[v]=eval_aexp(s, e)
+        return s1
         
     def tr_test(self,s: state,c: BoolExpr) -> state:
         if eval_bexp(s, c) is False:
-            return {}
+            return None
         else:
-            return s
+            if s:
+                return s.copy()
+            else:
+                return s
         
     def tr_err(self,s: state,e: Expr) -> state:
         if isinstance(e,ArithExpr):
             if eval_aexp(s ,e) is not None:
-                return s
-            else:
                 return None
+            else:
+                return s.copy()
         else:
             if isinstance(e,BoolExpr):
                 if eval_bexp(s ,e) is not None:
-                    return s
-                else:
                     return None
+                else:
+                    return s.copy()
             else: assert False