Merge pull request diffblue#384 from diffblue/remove_get_may_alias_values

SEC-360: Removed LVSA's 'get_may_alias_values'.

Author: marek-trtik

src/pointer-analysis/local_value_set.cpp

@@ -172,75 +172,6 @@ void local_value_sett::make_union_adjusting_types(
   }
 }
 
-/// Builds a version of expr suitable for alias-comparison
-/// \param expr: The expression to be converted to the alias-uniform structure
-/// \return expr without information which is irrelevant to alias-comparison
-static exprt get_uniform_expr(const exprt &expr)
-{
-  if(const auto desc_ptr = expr_try_dynamic_cast<object_descriptor_exprt>(expr))
-  {
-    object_descriptor_exprt ob;
-    ob.object() = get_uniform_expr(desc_ptr->object());
-    ob.offset() = desc_ptr->offset();
-    return ob;
-  }
-  if(can_cast_expr<external_value_set_exprt>(expr))
-  {
-    exprt copy = expr;
-    copy.set(ID_is_initializer, ID_0);
-    return copy;
-  }
-  return expr;
-}
-
-/// Reconstructs a type of a pointer to the object expr
-/// \param expr: An object in a points-to set we make an alias type for
-/// \return A type of a pointer to the object expr
-static typet get_alias_type(const exprt &expr)
-{
-  if(expr.id() == ID_object_descriptor)
-  {
-    object_descriptor_exprt ob_expr = to_object_descriptor_expr(expr);
-    if(
-      ob_expr.offset().id() == ID_invalid ||
-      ob_expr.offset().id() == ID_unknown)
-    {
-      return pointer_type(ob_expr.object().type());
-    }
-  }
-  return pointer_type(expr.type());
-}
-
-void local_value_sett::get_may_alias_set(
-  const exprt &expr,
-  value_setst::valuest &dest,
-  const namespacet &ns) const
-{
-  TMPROF_BLOCK();
-
-  object_mapt pointed_objects;
-  get_value_set(expr, pointed_objects, ns, false);
-  std::vector<exprt> uniform_pointed_objects;
-  for(const auto &num_obj : pointed_objects.read())
-    uniform_pointed_objects.push_back(get_uniform_expr(to_expr(num_obj)));
-
-  for(const auto &name_entry : values)
-    for(const auto &enum_eobj : name_entry.second.object_map.read())
-    {
-      if(
-        std::find(
-          uniform_pointed_objects.cbegin(),
-          uniform_pointed_objects.cend(),
-          get_uniform_expr(to_expr(enum_eobj))) !=
-        uniform_pointed_objects.cend())
-      {
-        dest.push_back(
-          symbol_exprt(
-            name_entry.second.identifier, get_alias_type(to_expr(enum_eobj))));
-      }
-    }
-}
-
 /// Value-set analysis accrues a `suffix` as it walks down an expression tree--
 /// for example, it transforms a `get_value_set_rec(x.y.z)` into
 /// `get_value_set_rec(x, suffix = ".y.z")`. This function recovers the type

src/pointer-analysis/local_value_set.h

@@ -67,15 +67,6 @@ class local_value_sett : public value_sett
   // For all the overrides below, see the base type for parameter-level docs
   // as their meanings are unchanged.
 
-  /// Computes all pointers which MAY point to objects pointed to by expr
-  /// \param expr: Identifies a points-to set for which to compute aliases
-  /// \param dest: Output container for pointers to objects pointed to by expr
-  /// \param ns: A reference to a symbol table
-  void get_may_alias_set(
-    const exprt &expr,
-    value_setst::valuest &dest,
-    const namespacet &ns) const;
-
   /// Overrides `value_sett::apply_code_rec` to erase `dead` statements and
   /// ignore intrinsic instructions that manipulate abstract taint but don't
   /// cause any actual data flow.

src/pointer-analysis/local_value_set_analysis.h

@@ -209,19 +209,6 @@ class local_value_set_analysist
   ///   call to the base class). false, otherwise.
   virtual bool is_singular(const std::set<exprt> &) override;
 
-  /// Fills in dest with all pointers to any object pointed to be expr
-  /// \param l: A program location w.r.t which the operation will be performed
-  /// \param expr: Identifies a points-to set whose aliases we will compute
-  /// \param dest: Output container for aliases
-  void get_may_alias_values(
-    locationt l,
-    const exprt &expr,
-    value_setst::valuest &dest)
-  {
-    ((const local_value_sett &)(*this)[l].value_set)
-      .get_may_alias_set(expr, dest, baset::ns);
-  }
-
 protected:
   /// Type of function under analysis
   const code_typet &function_type;