Merge pull request #6531 from tautschnig/null-cleanup

Use null_pointer_exprt

Author: kroening

src/ansi-c/c_typecast.cpp

@@ -537,8 +537,7 @@ void c_typecastt::implicit_typecast_followed(
        src_type.id()==ID_natural ||
        src_type.id()==ID_integer))
     {
-      expr=exprt(ID_constant, orig_dest_type);
-      expr.set(ID_value, ID_NULL);
+      expr = null_pointer_exprt{to_pointer_type(orig_dest_type)};
       return; // ok
     }
 

src/ansi-c/c_typecheck_expr.cpp

@@ -1382,14 +1382,14 @@ void c_typecheck_baset::typecheck_expr_rel(
     if(type0.id()==ID_pointer &&
        simplify_expr(op1, *this).is_zero())
     {
-      op1=constant_exprt(ID_NULL, type0);
+      op1 = null_pointer_exprt{to_pointer_type(type0)};
       return;
     }
 
     if(type1.id()==ID_pointer &&
        simplify_expr(op0, *this).is_zero())
     {
-      op0=constant_exprt(ID_NULL, type1);
+      op0 = null_pointer_exprt{to_pointer_type(type1)};
       return;
     }
 

src/cpp/parse.cpp

@@ -6743,7 +6743,7 @@ bool Parser::rPrimaryExpr(exprt &exp)
   case TOK_NULLPTR:
     lex.get_token(tk);
     // as an exception, we set the width of pointer
-    exp=constant_exprt(ID_NULL, pointer_type(typet(ID_nullptr)));
+    exp = null_pointer_exprt{pointer_type(typet(ID_nullptr))};
     set_location(exp, tk);
 #ifdef DEBUG
     std::cout << std::string(__indent, ' ') << "Parser::rPrimaryExpr 6\n";

unit/interpreter/interpreter.cpp

@@ -46,7 +46,7 @@ SCENARIO("interpreter evaluation null pointer expressions")
     unsignedbv_typet java_char(16);
     pointer_typet pointer_type(java_char, 64);
 
-    constant_exprt constant_expr(ID_NULL, pointer_type);
+    null_pointer_exprt constant_expr{pointer_type};
 
     mp_vectort mp_vector = interpreter_test.evaluate(constant_expr);