Remove const-cast from value_sett::get_entry

Author: smowton

src/pointer-analysis/value_set.cpp

@@ -57,7 +57,8 @@ value_sett::entryt *value_sett::find_entry(const value_sett::idt &id)
 const value_sett::entryt *value_sett::find_entry(const value_sett::idt &id)
 const
 {
-  return const_cast<value_sett *>(this)->find_entry(id);
+  auto found = values.find(id);
+  return found == values.end() ? nullptr : &found->second;
 }
 
 value_sett::entryt &value_sett::get_entry(const entryt &e, const typet &type)
@@ -371,11 +372,15 @@ static std::string strip_first_field_from_suffix(
   return suffix.substr(field.length() + 1);
 }
 
-value_sett::entryt *value_sett::get_entry_for_symbol(
+template<class maybe_const_value_sett>
+auto value_sett::get_entry_for_symbol(
+  maybe_const_value_sett &value_set,
   const irep_idt identifier,
   const typet &type,
   const std::string &suffix,
-  const namespacet &ns)
+  const namespacet &ns) ->
+  typename std::conditional<std::is_const<maybe_const_value_sett>::value,
+    const value_sett::entryt *, value_sett::entryt *>::type
 {
   if(
     type.id() != ID_pointer && type.id() != ID_signedbv &&
@@ -393,7 +398,8 @@ value_sett::entryt *value_sett::get_entry_for_symbol(
                                      : type;
 
   // look it up
-  value_sett::entryt *entry = find_entry(id2string(identifier) + suffix);
+  auto *entry =
+    value_set.find_entry(id2string(identifier) + suffix);
 
   // try first component name as suffix if not yet found
   if(
@@ -406,29 +412,40 @@ value_sett::entryt *value_sett::get_entry_for_symbol(
     const irep_idt &first_component_name =
       struct_union_type.components().front().get_name();
 
-    entry = find_entry(
+    entry = value_set.find_entry(
       id2string(identifier) + "." + id2string(first_component_name) + suffix);
   }
 
   if(!entry)
   {
     // not found? try without suffix
-    entry = find_entry(identifier);
+    entry = value_set.find_entry(identifier);
   }
 
   return entry;
 }
 
+// Explicitly instantiate the two possible versions of the method above:
+
+value_sett::entryt *value_sett::get_entry_for_symbol(
+  irep_idt identifier,
+  const typet &type,
+  const std::string &suffix,
+  const namespacet &ns)
+{
+  return get_entry_for_symbol(*this, identifier, type, suffix, ns);
+}
+
 const value_sett::entryt *value_sett::get_entry_for_symbol(
-  const irep_idt identifier,
+  irep_idt identifier,
   const typet &type,
   const std::string &suffix,
   const namespacet &ns) const
 {
-  return const_cast<value_sett *>(this)->get_entry_for_symbol(
-    identifier, type, suffix, ns);
+  return get_entry_for_symbol(*this, identifier, type, suffix, ns);
 }
 
+
 void value_sett::get_value_set_rec(
   const exprt &expr,
   object_mapt &dest,

src/pointer-analysis/value_set.h

@@ -13,6 +13,7 @@ Author: Daniel Kroening, [email protected]
 #define CPROVER_POINTER_ANALYSIS_VALUE_SET_H
 
 #include <set>
+#include <type_traits>
 #include <unordered_set>
 
 #include <util/mp_arith.h>
@@ -464,6 +465,19 @@ class value_sett
     exprt &expr,
     const namespacet &ns) const;
 
+private:
+  /// Helper method for \ref get_entry_for_symbol
+  template<class maybe_const_value_sett>
+  static auto get_entry_for_symbol(
+    maybe_const_value_sett &value_set,
+    irep_idt identifier,
+    const typet &type,
+    const std::string &suffix,
+    const namespacet &ns) ->
+    typename std::conditional<std::is_const<maybe_const_value_sett>::value,
+    const value_sett::entryt *, value_sett::entryt *>::type;
+
+public:
   /// Get the entry for the symbol and suffix
   /// \param identifier: The identifier for the symbol
   /// \param type: The type of the symbol