Move "is hidden" attribute of goto functions out of type

Whether the execution of a goto function is to be hidden has nothing to
do with its signature, and therefore should not be included in the type
(irrespective of whether the type is stored in goto_functiont or in the
symbol table).

As this attribute is recomputed upon reading a goto binary, there is no
need to store it in the goto binary, and thus also no need to bump the
goto-binary version number.

Author: tautschnig

src/goto-programs/goto_function.h

@@ -60,19 +60,17 @@ class goto_functiont
     return type.get_bool(ID_C_inlined);
   }
 
-  DEPRECATED(SINCE(2019, 2, 16, "Get the type from the symbol table instead"))
   bool is_hidden() const
   {
-    return type.get_bool(ID_C_hide);
+    return function_is_hidden;
   }
 
-  DEPRECATED(SINCE(2019, 2, 16, "Get the type from the symbol table instead"))
   void make_hidden()
   {
-    type.set(ID_C_hide, true);
+    function_is_hidden = true;
   }
 
-  goto_functiont() : body(), type({}, empty_typet())
+  goto_functiont() : body(), type({}, empty_typet()), function_is_hidden(false)
   {
   }
 
@@ -81,20 +79,23 @@ class goto_functiont
     body.clear();
     type.clear();
     parameter_identifiers.clear();
+    function_is_hidden = false;
   }
 
   void swap(goto_functiont &other)
   {
     body.swap(other.body);
     type.swap(other.type);
     parameter_identifiers.swap(other.parameter_identifiers);
+    std::swap(function_is_hidden, other.function_is_hidden);
   }
 
   void copy_from(const goto_functiont &other)
   {
     body.copy_from(other.body);
     type = other.type;
     parameter_identifiers = other.parameter_identifiers;
+    function_is_hidden = other.function_is_hidden;
   }
 
   goto_functiont(const goto_functiont &) = delete;
@@ -103,7 +104,8 @@ class goto_functiont
   goto_functiont(goto_functiont &&other)
     : body(std::move(other.body)),
       type(std::move(other.type)),
-      parameter_identifiers(std::move(other.parameter_identifiers))
+      parameter_identifiers(std::move(other.parameter_identifiers)),
+      function_is_hidden(other.function_is_hidden)
   {
   }
 
@@ -112,6 +114,7 @@ class goto_functiont
     body = std::move(other.body);
     type = std::move(other.type);
     parameter_identifiers = std::move(other.parameter_identifiers);
+    function_is_hidden = other.function_is_hidden;
     return *this;
   }
 
@@ -120,6 +123,9 @@ class goto_functiont
   /// The validation mode indicates whether well-formedness check failures are
   /// reported via DATA_INVARIANT violations or exceptions.
   void validate(const namespacet &ns, const validation_modet vm) const;
+
+protected:
+  bool function_is_hidden;
 };
 
 void get_local_identifiers(const goto_functiont &, std::set<irep_idt> &dest);

src/goto-programs/read_bin_goto_object.cpp

@@ -131,8 +131,8 @@ static bool read_bin_goto_object(
         instruction.labels.push_back(label);
         if(label == CPROVER_PREFIX "HIDE")
           hidden=true;
-        // The above info is normally in the type of the goto_functiont object,
-        // which should likely be stored in the binary.
+        // The above info is also held in the goto_functiont object, and could
+        // be stored in the binary.
       }
     }
 

src/util/irep_ids.def

@@ -285,7 +285,6 @@ IREP_ID_ONE(signed_int128)
 IREP_ID_ONE(unsigned_int128)
 IREP_ID_ONE(case)
 IREP_ID_TWO(C_inlined, #inlined)
-IREP_ID_TWO(C_hide, #hide)
 IREP_ID_ONE(hide)
 IREP_ID_ONE(abs)
 IREP_ID_ONE(sign)