type simplify_member

This improves memory safety.

Author: kroening

src/util/simplify_expr.cpp

@@ -2126,7 +2126,7 @@ bool simplify_exprt::simplify_node(exprt &expr)
   }
   else if(expr.id()==ID_member)
   {
-    r = simplify_member(expr);
+    r = simplify_member(to_member_expr(expr));
   }
   else if(expr.id()==ID_byte_update_little_endian ||
           expr.id()==ID_byte_update_big_endian)

src/util/simplify_expr_class.h

@@ -158,7 +158,7 @@ class simplify_exprt
   NODISCARD resultt<> simplify_with(const exprt &);
   NODISCARD resultt<> simplify_update(const exprt &);
   NODISCARD resultt<> simplify_index(const index_exprt &);
-  NODISCARD resultt<> simplify_member(const exprt &);
+  NODISCARD resultt<> simplify_member(const member_exprt &);
   NODISCARD resultt<> simplify_byte_update(const byte_update_exprt &);
   NODISCARD resultt<> simplify_byte_extract(const byte_extract_exprt &);
   NODISCARD resultt<> simplify_pointer_object(const exprt &);

src/util/simplify_expr_struct.cpp

@@ -15,15 +15,13 @@ Author: Daniel Kroening, [email protected]
 #include "pointer_offset_size.h"
 #include "std_expr.h"
 
-simplify_exprt::resultt<> simplify_exprt::simplify_member(const exprt &expr)
+simplify_exprt::resultt<>
+simplify_exprt::simplify_member(const member_exprt &expr)
 {
-  if(expr.operands().size()!=1)
-    return unchanged(expr);
-
   const irep_idt &component_name=
     to_member_expr(expr).get_component_name();
 
-  const exprt &op = expr.op0();
+  const exprt &op = expr.struct_op();
   const typet &op_type=ns.follow(op.type());
 
   if(op.id()==ID_with)
@@ -60,7 +58,7 @@ simplify_exprt::resultt<> simplify_exprt::simplify_member(const exprt &expr)
       DATA_INVARIANT(new_operands.size() == 1, "post-condition of loop");
 
       auto new_member_expr = expr;
-      new_member_expr.op0() = new_operands.front();
+      new_member_expr.struct_op() = new_operands.front();
       // do this recursively
       return simplify_member(new_member_expr);
     }
@@ -104,7 +102,7 @@ simplify_exprt::resultt<> simplify_exprt::simplify_member(const exprt &expr)
         {
           // UPDATE(s, .m1, v).m2 -> s.m2
           auto new_expr = expr;
-          new_expr.op0() = update_expr.old();
+          new_expr.struct_op() = update_expr.old();
 
           // do this recursively
           return changed(simplify_rec(new_expr));
@@ -211,7 +209,7 @@ simplify_exprt::resultt<> simplify_exprt::simplify_member(const exprt &expr)
     if(op_type == op.op0().type())
     {
       auto new_expr = expr;
-      new_expr.op0() = op.op0();
+      new_expr.struct_op() = op.op0();
       return simplify_member(new_expr);
     }