Store "is hidden" attribute of goto functions in the symbol table

There should only be a single place to hold type information, including
attributes, to ensure consistency. Future changes will remove the "type" member
of goto_functiont, making the type information stored in the symbol table the
single, authoritative source of information.

With this commit the information will remain available in both places, but all
read accesses only use the information in the symbol table.

Author: tautschnig

src/goto-instrument/cover_filter.cpp

@@ -29,7 +29,7 @@ bool internal_functions_filtert::operator()(
   if(function.name == INITIALIZE_FUNCTION)
     return false;
 
-  if(goto_function.is_hidden())
+  if(to_code_type(function.type).is_hidden())
     return false;
 
   // ignore Java built-ins (synthetic functions)

src/goto-programs/goto_convert_functions.cpp

@@ -216,7 +216,10 @@ void goto_convert_functionst::convert_function(
   f.body.update();
 
   if(hide(f.body))
+  {
     f.make_hidden();
+    to_code_type(symbol_table.get_writeable_ref(identifier).type).make_hidden();
+  }
 
   lifetime = parent_lifetime;
 }

src/goto-programs/goto_inline_class.cpp

@@ -253,7 +253,7 @@ void goto_inlinet::insert_function_body(
   end.type=LOCATION;
 
   // make sure the inlined function does not introduce hiding
-  if(goto_function.is_hidden())
+  if(to_code_type(ns.lookup(identifier).type).is_hidden())
   {
     for(auto &instruction : body.instructions)
       instruction.labels.remove(CPROVER_PREFIX "HIDE");

src/goto-programs/read_bin_goto_object.cpp

@@ -160,7 +160,10 @@ static bool read_bin_goto_object(
     f.body.update();
 
     if(hidden)
+    {
       f.make_hidden();
+      to_code_type(symbol_table.get_writeable_ref(fname).type).make_hidden();
+    }
   }
 
   functions.compute_location_numbers();

src/goto-symex/symex_function_call.cpp

@@ -274,7 +274,9 @@ void goto_symext::symex_function_call_code(
     a = state.rename(std::move(a), ns);
 
   // we hide the call if the caller and callee are both hidden
-  const bool hidden = state.top().hidden_function && goto_function.is_hidden();
+  const bool callee_is_hidden =
+    to_code_type(ns.lookup(identifier).type).is_hidden();
+  const bool hidden = state.top().hidden_function && callee_is_hidden;
 
   // record the call
   target.function_call(
@@ -313,7 +315,7 @@ void goto_symext::symex_function_call_code(
   frame.end_of_function=--goto_function.body.instructions.end();
   frame.return_value=call.lhs();
   frame.function_identifier=identifier;
-  frame.hidden_function=goto_function.is_hidden();
+  frame.hidden_function = callee_is_hidden;
 
   const framet &p_frame = state.previous_frame();
   for(const auto &pair : p_frame.loop_iterations)

src/goto-symex/symex_main.cpp

@@ -325,7 +325,8 @@ std::unique_ptr<goto_symext::statet> goto_symext::initialize_entry_point_state(
     std::prev(start_function->body.instructions.end());
   state->top().end_of_function = limit;
   state->top().calling_location.pc = state->top().end_of_function;
-  state->top().hidden_function = start_function->is_hidden();
+  state->top().hidden_function =
+    to_code_type(ns.lookup(entry_point_id).type).is_hidden();
 
   state->symex_target = &target;
 

src/util/std_types.h

@@ -896,6 +896,16 @@ class code_typet:public typet
     set(ID_C_inlined, value);
   }
 
+  bool is_hidden() const
+  {
+    return get_bool(ID_C_hide);
+  }
+
+  void make_hidden()
+  {
+    set(ID_C_hide, true);
+  }
+
   const irep_idt &get_access() const
   {
     return get(ID_access);