// $Id$

// ============================================================================
//
// = LIBRARY
//    TAO IDL
//
// = FILENAME
//    be_union.cpp
//
// = DESCRIPTION
//    Extension of class AST_Union that provides additional means for C++
//    mapping.
//
// = AUTHOR
//    Copyright 1994-1995 by Sun Microsystems, Inc.
//    and
//    Aniruddha Gokhale
//
// ============================================================================

#include "be_union.h"
#include "be_visitor.h"
#include "be_codegen.h"
#include "be_helper.h"
#include "be_extern.h"

#include "ast_union_branch.h"
#include "utl_identifier.h"
#include "idl_defines.h"
#include "global_extern.h"

ACE_RCSID (be,
           be_union,
           "$Id$")


be_union::be_union (void)
  : COMMON_Base (),
    AST_Decl (),
    AST_Type (),
    AST_ConcreteType (),
    UTL_Scope (),
    AST_Structure (),
    AST_Union (),
    be_scope (),
    be_decl (),
    be_type ()
{
  // Always the case.
  this->has_constructor (true);
}

be_union::be_union (AST_ConcreteType *dt,
                    UTL_ScopedName *n,
                    bool local,
                    bool abstract)
  : COMMON_Base (local,
                 abstract),
    AST_Decl (AST_Decl::NT_union,
              n),
    AST_Type (AST_Decl::NT_union,
              n),
    AST_ConcreteType (AST_Decl::NT_union,
                      n),
    UTL_Scope (AST_Decl::NT_union),
    AST_Structure (AST_Decl::NT_union,
                   n,
                   local,
                   abstract),
    AST_Union (dt,
               n,
               local,
               abstract),
    be_scope (AST_Decl::NT_union),
    be_decl (AST_Decl::NT_union,
             n),
    be_type (AST_Decl::NT_union,
             n)
{
  // Always the case.
  this->has_constructor (true);

  if (!this->imported ())
    {
      idl_global->aggregate_seen_ = true;

      idl_global->union_seen_ = true;
    }
}

void
be_union::redefine (AST_Structure *from)
{
  be_union *bu = be_union::narrow_from_decl (from);
  this->common_varout_gen_ = bu->common_varout_gen_;
  AST_Union::redefine (from);
}

bool
be_union::has_duplicate_case_labels (void)
{
  for (UTL_ScopeActiveIterator si (this, UTL_Scope::IK_decls);
       !si.is_done ();
       si.next ())
    {
      AST_Decl *d = si.item ();
      AST_UnionBranch *ub =
        AST_UnionBranch::narrow_from_decl (d);

      if (ub->label_list_length () > 1)
        {
          return true;
        }
    }

  return false;
}

void
be_union::destroy (void)
{
  // Call the destroy methods of our base classes.
  this->be_scope::destroy ();
  this->be_type::destroy ();
  this->AST_Union::destroy ();
  
}

// Visitor method.
int
be_union::accept (be_visitor *visitor)
{
  return visitor->visit_union (this);
}

bool
be_union::gen_empty_default_label (void)
{
  // A non-empty explicit default label will be generated.
  if (this->default_index () != -1)
    {
      return false;
    }

  AST_ConcreteType *disc = this->disc_type ();
  AST_Decl::NodeType nt = disc->node_type ();

  if (nt == AST_Decl::NT_enum)
    {
      return true;
    }

  AST_PredefinedType *pdt = AST_PredefinedType::narrow_from_decl (disc);

  if (pdt == 0)
    {
      return true;
    }

  unsigned long n_labels = this->nlabels ();

  if (pdt->pt () == AST_PredefinedType::PT_boolean && n_labels == 2)
    {
      return false;
    }

  return true;
}

unsigned long
be_union::nlabels (void)
{
  unsigned long retval = 0;

  for (UTL_ScopeActiveIterator si (this, UTL_Scope::IK_decls);
       !si.is_done ();
       si.next ())
    {
      AST_Decl *d = si.item ();
      AST_UnionBranch *ub =
        AST_UnionBranch::narrow_from_decl (d);

      if (ub != 0)
        {
          retval += ub->label_list_length ();
        }
    }

  return retval;
}

// Narrowing.
IMPL_NARROW_METHODS3 (be_union, AST_Union, be_scope, be_type)
IMPL_NARROW_FROM_DECL (be_union)
IMPL_NARROW_FROM_SCOPE (be_union)