// ast_union.cpp,v 1.40 2006/02/13 14:31:51 parsons Exp

/*

COPYRIGHT

Copyright 1992, 1993, 1994 Sun Microsystems, Inc.  Printed in the United
States of America.  All Rights Reserved.

This product is protected by copyright and distributed under the following
license restricting its use.

The Interface Definition Language Compiler Front End (CFE) is made
available for your use provided that you include this license and copyright
notice on all media and documentation and the software program in which
this product is incorporated in whole or part. You may copy and extend
functionality (but may not remove functionality) of the Interface
Definition Language CFE without charge, but you are not authorized to
license or distribute it to anyone else except as part of a product or
program developed by you or with the express written consent of Sun
Microsystems, Inc. ("Sun").

The names of Sun Microsystems, Inc. and any of its subsidiaries or
affiliates may not be used in advertising or publicity pertaining to
distribution of Interface Definition Language CFE as permitted herein.

This license is effective until terminated by Sun for failure to comply
with this license.  Upon termination, you shall destroy or return all code
and documentation for the Interface Definition Language CFE.

INTERFACE DEFINITION LANGUAGE CFE IS PROVIDED AS IS WITH NO WARRANTIES OF
ANY KIND INCLUDING THE WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS
FOR A PARTICULAR PURPOSE, NONINFRINGEMENT, OR ARISING FROM A COURSE OF
DEALING, USAGE OR TRADE PRACTICE.

INTERFACE DEFINITION LANGUAGE CFE IS PROVIDED WITH NO SUPPORT AND WITHOUT
ANY OBLIGATION ON THE PART OF Sun OR ANY OF ITS SUBSIDIARIES OR AFFILIATES
TO ASSIST IN ITS USE, CORRECTION, MODIFICATION OR ENHANCEMENT.

SUN OR ANY OF ITS SUBSIDIARIES OR AFFILIATES SHALL HAVE NO LIABILITY WITH
RESPECT TO THE INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY
INTERFACE DEFINITION LANGUAGE CFE OR ANY PART THEREOF.

IN NO EVENT WILL SUN OR ANY OF ITS SUBSIDIARIES OR AFFILIATES BE LIABLE FOR
ANY LOST REVENUE OR PROFITS OR OTHER SPECIAL, INDIRECT AND CONSEQUENTIAL
DAMAGES, EVEN IF SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.

Use, duplication, or disclosure by the government is subject to
restrictions as set forth in subparagraph (c)(1)(ii) of the Rights in
Technical Data and Computer Software clause at DFARS 252.227-7013 and FAR
52.227-19.

Sun, Sun Microsystems and the Sun logo are trademarks or registered
trademarks of Sun Microsystems, Inc.

SunSoft, Inc.
2550 Garcia Avenue
Mountain View, California  94043

NOTE:

SunOS, SunSoft, Sun, Solaris, Sun Microsystems or the Sun logo are
trademarks or registered trademarks of Sun Microsystems, Inc.

*/

// AST_Union nodes represent IDL union declarations.
// AST_Union is a subclass of AST_ConcreteType and of UTL_Scope (the
// union branches are managed in a scope).
// AST_Union nodes have a discriminator type (a subclass of AST_ConcreteType),
// a name (an UTL_ScopedName) and a field denoting the discriminator type if
// it is a primitive type (the value of this field is from the union
// AST_Expression::ExprType and serves as a cache). This field is used
// to compute coercions for labels based on the expected discriminator type.

#include "ast_union.h"
#include "ast_union_branch.h"
#include "ast_union_label.h"
#include "ast_field.h"
#include "ast_predefined_type.h"
#include "ast_enum.h"
#include "ast_enum_val.h"
#include "ast_visitor.h"
#include "utl_err.h"
#include "utl_identifier.h"
#include "utl_indenter.h"
#include "global_extern.h"

// FUZZ: disable check_for_streams_include
#include "ace/streams.h"

ACE_RCSID (ast,
           ast_union,
           "ast_union.cpp,v 1.40 2006/02/13 14:31:51 parsons Exp")

AST_Union::AST_Union (void)
  : COMMON_Base (),
    AST_Decl (),
    AST_Type (),
    AST_ConcreteType (),
    UTL_Scope (),
    AST_Structure (),
    default_index_ (-2)
{
}

AST_Union::AST_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 (n,
                   local,
                   abstract),
    default_index_ (-2)
{
  this->default_value_.computed_ = -2;

  AST_PredefinedType *pdt = 0;

  if (dt == 0)
    {
      this->pd_disc_type = 0;
      this->pd_udisc_type = AST_Expression::EV_none;
      return;
    }

  // If the discriminator type is a predefined type
  // then install the equivalent coercion target type in
  // the pd_udisc_type field.
  if (dt->node_type () == AST_Decl::NT_pre_defined)
    {
      pdt = AST_PredefinedType::narrow_from_decl (dt);

      if (pdt == 0)
        {
          this->pd_disc_type = 0;
          this->pd_udisc_type = AST_Expression::EV_none;
          return;
        }

      pd_disc_type = dt;

      switch (pdt->pt ())
        {
        case AST_PredefinedType::PT_long:
          this->pd_udisc_type = AST_Expression::EV_long;
          break;
        case AST_PredefinedType::PT_ulong:
          this->pd_udisc_type = AST_Expression::EV_ulong;
          break;
        case AST_PredefinedType::PT_short:
          this->pd_udisc_type = AST_Expression::EV_short;
          break;
        case AST_PredefinedType::PT_ushort:
          this->pd_udisc_type = AST_Expression::EV_ushort;
          break;
        case AST_PredefinedType::PT_char:
          this->pd_udisc_type = AST_Expression::EV_char;
          break;
        case AST_PredefinedType::PT_wchar:
          this->pd_udisc_type = AST_Expression::EV_wchar;
          break;
        case AST_PredefinedType::PT_octet:
          this->pd_udisc_type = AST_Expression::EV_octet;
          break;
        case AST_PredefinedType::PT_boolean:
          this->pd_udisc_type = AST_Expression::EV_bool;
          break;
        default:
          this->pd_udisc_type = AST_Expression::EV_none;
          this->pd_disc_type = 0;
          break;
        }
    }
  else if (dt->node_type () == AST_Decl::NT_enum)
    {
      this->pd_udisc_type = AST_Expression::EV_enum;
      this->pd_disc_type = dt;
    }
  else
    {
      this->pd_udisc_type = AST_Expression::EV_none;
      this->pd_disc_type = 0;
    }

  if (this->pd_disc_type == 0)
    {
      idl_global->err ()->error2 (UTL_Error::EIDL_DISC_TYPE,
                                  this,
                                  dt);
    }
}

AST_Union::~AST_Union (void)
{
}

// Public operations.

void
AST_Union::redefine (AST_Structure *from)
{
  AST_Union *u = AST_Union::narrow_from_decl (from);

  if (u == 0)
    {
      idl_global->err ()->redef_error (from->local_name ()->get_string (),
                                       this->local_name ()->get_string ());
      return;
    }

  // Copy over all the base class members.
  this->AST_Structure::redefine (from);

  this->pd_disc_type = u->pd_disc_type;
  this->pd_udisc_type = u->pd_udisc_type;
  this->default_index_ = u->default_index_;
  this->default_value_ = u->default_value_;
}

// Return the default_index.
int
AST_Union::default_index (void)
{
  if (this->default_index_ == -2)
    {
      this->compute_default_index ();
    }

  return this->default_index_;
}

// Are we or the parameter node involved in any recursion?
bool
AST_Union::in_recursion (ACE_Unbounded_Queue<AST_Type *> &list)
{
  // Proceed if the number of members in our scope is greater than 0.
  if (this->nmembers () > 0)
    {
      ACE_Unbounded_Queue<AST_Type *> scope_list = list;
      scope_list.enqueue_tail (this);

      // Initialize an iterator to iterate thru our scope.
      // Continue until each element is visited.
      for (UTL_ScopeActiveIterator si (this, UTL_Scope::IK_decls);
           !si.is_done ();
           si.next ())
        {
          AST_UnionBranch *field =
            AST_UnionBranch::narrow_from_decl (si.item ());

          if (field == 0)
            // This will be an enum value or other legitimate non-field
            // member - in any case, no recursion.
            {
              continue;
            }

          AST_Type *type = field->field_type ();

          if (type->node_type () == AST_Decl::NT_typedef)
            {
              AST_Typedef *td = AST_Typedef::narrow_from_decl (type);
              type = td->primitive_base_type ();
            }

          if (type == 0)
            {
              ACE_ERROR_RETURN ((LM_ERROR,
                                 ACE_TEXT ("(%N:%l) AST_Union::")
                                 ACE_TEXT ("in_recursion - ")
                                 ACE_TEXT ("bad field type\n")),
                                0);
            }

          if (type->in_recursion (scope_list))
            {
              this->in_recursion_ = 1;
              idl_global->recursive_type_seen_ = true;
              return this->in_recursion_;
            }
        }
    }

  // Not in recursion.
  this->in_recursion_ = 0;
  return this->in_recursion_;
}

// Look up the default branch in union.
AST_UnionBranch *
AST_Union::lookup_default (void)
{
  AST_UnionBranch *b = 0;
  AST_Decl *d = 0;

  for (UTL_ScopeActiveIterator i (this, UTL_Scope::IK_both);
       !i.is_done();
       i.next ())
    {
      d = i.item ();

      if (d->node_type () == AST_Decl::NT_union_branch)
        {
          b = AST_UnionBranch::narrow_from_decl (d);

          if (b == 0)
            {
              continue;
            }

          if (b->label () != 0
              && b->label ()->label_kind () == AST_UnionLabel::UL_default)
            {
              idl_global->err ()->error2 (UTL_Error::EIDL_MULTIPLE_BRANCH,
                                          this,
                                          b);
              return b;
            }
        }
    }

  return 0;
}

// Look up a branch by label.
AST_UnionBranch *
AST_Union::lookup_label (AST_UnionBranch *b)
{
  AST_UnionLabel *label = b->label ();
  AST_Expression *lv = label->label_val ();

  if (label->label_val () == 0)
    {
      return b;
    }

  AST_Decl *d = 0;
  AST_UnionBranch       *fb = 0;

  lv->set_ev (lv->coerce (this->pd_udisc_type));

  if (lv->ev () == 0)
    {
      idl_global->err ()->eval_error (lv);
      return b;
    }

  for (UTL_ScopeActiveIterator i (this, UTL_Scope::IK_decls);
       !i.is_done();
       i.next ())
    {
      d = i.item ();

      if (d->node_type () == AST_Decl::NT_union_branch)
        {
          fb = AST_UnionBranch::narrow_from_decl (d);

          if (fb == 0)
            {
              continue;
            }

          if (fb->label() != 0
              && fb->label ()->label_kind () == AST_UnionLabel::UL_label
              && fb->label ()->label_val ()->compare (lv))
            {
              idl_global->err ()->error2  (UTL_Error::EIDL_MULTIPLE_BRANCH,
                                           this,
                                           b);
              return b;
            }
        }
    }

  return 0;
}

// Look up a branch in an enum which is the discriminator type for this
// union, based on the label value which must be an enumerator in that
// enum.
AST_UnionBranch *
AST_Union::lookup_enum (AST_UnionBranch *b)
{
  AST_UnionLabel *label = b->label();
  AST_Expression *lv = label->label_val ();
  AST_Enum *e = AST_Enum::narrow_from_decl (this->pd_disc_type);
  AST_Decl *d = 0;
  AST_UnionBranch       *fb = 0;

  if (e == 0)
    {
      return 0;
    }

  if (lv == 0)
    {
      return b;
    }

  // Expecting a symbol label.
  if (lv->ec () != AST_Expression::EC_symbol)
    {
      idl_global->err ()->enum_val_expected (this,
                                             label);
      return b;
    }

  // See if the symbol defines a constant in the discriminator enum.
  UTL_ScopedName *sn = lv->n ();
  d = e->lookup_by_name (sn,
                         true);

  if (d == 0 || d->defined_in () != e)
    {
      idl_global->err ()->enum_val_lookup_failure (this,
                                                   e,
                                                   sn);
      return b;
    }

  // OK, now see if this symbol is already used as the label of
  // some other branch.
  for (UTL_ScopeActiveIterator i (this, UTL_Scope::IK_decls);
       !i.is_done();
       i.next ())
    {
      d = i.item ();

      if (d->node_type () == AST_Decl::NT_union_branch)
        {
          fb = AST_UnionBranch::narrow_from_decl (d);

          if (fb == 0)
            {
              continue;
            }

          if (fb->label() != 0
              && fb->label ()->label_kind () == AST_UnionLabel::UL_label
              && fb->label ()->label_val ()->compare (lv))
            {
              idl_global->err ()->error2 (UTL_Error::EIDL_MULTIPLE_BRANCH,
                                          this,
                                          b);
              return b;
            }
        }
    }

  return 0;
}

// Look up a branch by value. This is the top level branch label resolution
// entry point. It dispatches to the right lookup function depending on the
// union discriminator type.
AST_UnionBranch *
AST_Union::lookup_branch (AST_UnionBranch *branch)
{
  AST_UnionLabel *label = 0;

  if (branch != 0)
    {
      label = branch->label ();
    }

  if (label != 0)
    {
      if (label->label_kind () == AST_UnionLabel::UL_default)
        {
          return this->lookup_default ();
        }

      if (this->pd_udisc_type == AST_Expression::EV_enum)
        {
          // CONVENTION: indicates enum discriminant.
          return this->lookup_enum (branch);
        }

      return this->lookup_label (branch);
    }

  return 0;
}

// Return the default value.
int
AST_Union::default_value (AST_Union::DefaultValue &dv)
{
  if (this->default_value_.computed_ == -2)
    {
      // We need to compute it.
      if (this->compute_default_value () == -1)
        {
          ACE_ERROR_RETURN ((LM_ERROR,
                             ACE_TEXT ("(%N:%l) AST_Union::")
                             ACE_TEXT ("default_value - ")
                             ACE_TEXT ("Error computing ")
                             ACE_TEXT ("default value\n")),
                            -1);
        }
    }

  dv = this->default_value_;
  return 0;
}

// Determine the default value (if any).
int
AST_Union::compute_default_value (void)
{
  // Check if we really need a default value. This will be true if there is an
  // explicit default case OR if an implicit default exists because not all
  // values of the discriminant type are covered by the cases.

  // Compute the total true "case" labels i.e., exclude the "default" case.
  int total_case_members = 0;

  // Instantiate a scope iterator.
  for (UTL_ScopeActiveIterator si (this, UTL_Scope::IK_decls);
       !si.is_done ();
       si.next ())
    {
      // Get the next AST decl node.
      AST_UnionBranch *ub =
        AST_UnionBranch::narrow_from_decl (si.item ());

      if (ub != 0)
        {
          // If the label is a case label, increment by 1.
          for (unsigned long i = 0; i < ub->label_list_length (); ++i)
            {
              if (ub->label (i)->label_kind () == AST_UnionLabel::UL_label)
                {
                  ++total_case_members;
                }
            }
        }
    }

  // Check if the total_case_members cover the entire
  // range of values that are permitted by the discriminant type. If they do,
  // then a default value is not necessary. However, if such an explicit
  // default case is provided, it must be flagged off as an error. Our
  // front-end is not able to handle such a case since it is a semantic error
  // and not a syntax error. Such an error is caught here.

  switch (this->udisc_type ())
    {
    case AST_Expression::EV_short:
    case AST_Expression::EV_ushort:
      if (total_case_members == ACE_UINT16_MAX + 1)
        {
          this->default_value_.computed_ = 0;
        }

      break;
    case AST_Expression::EV_long:
    case AST_Expression::EV_ulong:
      if ((unsigned int) total_case_members > ACE_UINT32_MAX)
        {
          this->default_value_.computed_ = 0;
        }

      break;
    case AST_Expression::EV_longlong:
    case AST_Expression::EV_ulonglong:
      // Error for now.
      this->default_value_.computed_ = -1;
      ACE_ERROR_RETURN ((
          LM_ERROR,
          ACE_TEXT ("(%N:%l) AST_Union::compute_default_value ")
          ACE_TEXT ("- unimplemented discriminant type ")
          ACE_TEXT ("(longlong or ulonglong)\n")
        ),
        -1
      );
      ACE_NOTREACHED (break;)
    case AST_Expression::EV_char:
      if (total_case_members == ACE_OCTET_MAX + 1)
        {
          this->default_value_.computed_ = 0;
        }

      break;
    case AST_Expression::EV_wchar:
      if (total_case_members == ACE_WCHAR_MAX + 1)
        {
          this->default_value_.computed_ = 0;
        }

      break;
    case AST_Expression::EV_bool:
      if (total_case_members == 2)
        {
          this->default_value_.computed_ = 0;
        }

      break;
    case AST_Expression::EV_enum:
      // Has to be enum.
      {
        AST_Decl *d = AST_Decl::narrow_from_decl (this->disc_type ());

        if (d->node_type () == AST_Decl::NT_typedef)
          {
            AST_Typedef *bt = AST_Typedef::narrow_from_decl (d);
            d = bt->primitive_base_type ();
          }

        AST_Enum *en = AST_Enum::narrow_from_decl (d);

        if (en != 0)
          {
            if (total_case_members == en->member_count ())
              {
                this->default_value_.computed_ = 0;
              }
          }
        else
          {
            // Error.
            this->default_value_.computed_ = -1;
            ACE_ERROR_RETURN ((LM_ERROR,
                               ACE_TEXT ("(%N:%l) AST_Union::")
                               ACE_TEXT ("compute_default_value ")
                               ACE_TEXT ("- disc type not an ENUM\n")),
                              -1);
          }
      }
      break;
    default:
      // Error.
      this->default_value_.computed_ = -1;
      ACE_ERROR_RETURN ((LM_ERROR,
                         ACE_TEXT ("(%N:%l) AST_Union::compute_default_value")
                         ACE_TEXT (" - Bad discriminant type\n")),
                        -1);
      ACE_NOTREACHED (break;)
    } // End of switch

  // If we have determined that we don't have a default case and even then a
  // default case was provided, flag this off as error.
  if ((this->default_value_.computed_ == 0)
      && (this->default_index () != -1))
    {
      // Error.
      this->default_value_.computed_ = -1;
      ACE_ERROR_RETURN ((LM_ERROR,
                         ACE_TEXT ("(%N:%l) AST_Union::compute_default_value")
                         ACE_TEXT (" - default clause is invalid here\n")),
                        -1);
    }

  // Proceed only if necessary.
  switch (this->default_value_.computed_)
    {
    case -1:
      // Error. We should never be here because errors
      // have already been caught
      // above.
      return -1;
    case 0:
      // Nothing more to do.
      return 0;
    default:
      // Proceed further down.
      break;
    }

  // Initialization of the default value data member.
  switch (this->udisc_type ())
    {
    case AST_Expression::EV_short:
      this->default_value_.u.short_val = ACE_INT16_MIN;
      break;
    case AST_Expression::EV_ushort:
      this->default_value_.u.ushort_val = 0;
      break;
    case AST_Expression::EV_long:
      // The +1 is to avert a warning on many compilers.
      this->default_value_.u.long_val = ACE_INT32_MIN + 1;
      break;
    case AST_Expression::EV_ulong:
      this->default_value_.u.ulong_val = 0;
      break;
    case AST_Expression::EV_char:
      this->default_value_.u.char_val = 0;
      break;
    case AST_Expression::EV_wchar:
      this->default_value_.u.wchar_val = 0;
      break;
    case AST_Expression::EV_bool:
      this->default_value_.u.bool_val = 0;
      break;
    case AST_Expression::EV_enum:
      this->default_value_.u.enum_val = 0;
      break;
    case AST_Expression::EV_longlong:
    case AST_Expression::EV_ulonglong:
      // Unimplemented.
    default:
      // Error caught earlier.
      break;
    }

  // Proceed until we have found the appropriate default value.
  while (this->default_value_.computed_ == -2)
    {
      int break_loop = 0;

      // Instantiate a scope iterator.
      for (UTL_ScopeActiveIterator si (this, UTL_Scope::IK_decls);
           !si.is_done () && break_loop == 0;
           si.next ())
        {
          // Get the next AST decl node
          AST_UnionBranch *ub =
            AST_UnionBranch::narrow_from_decl (si.item ());

          if (ub != 0)
            {
              for (unsigned long i = 0;
                   i < ub->label_list_length () && !break_loop;
                   ++i)
                {
                  if (ub->label (i)->label_kind () == AST_UnionLabel::UL_label)
                    {
                      // Not a default.
                      AST_Expression *expr = ub->label (i)->label_val ();

                      if (expr == 0)
                        {
                          // Error.
                          this->default_value_.computed_ = -1;
                          ACE_ERROR_RETURN ((
                              LM_ERROR,
                              ACE_TEXT ("(%N:%l) AST_Union::")
                              ACE_TEXT ("compute_default_value - ")
                              ACE_TEXT ("Bad case label value\n")
                            ),
                            -1
                          );
                        }

                      switch (expr->ev ()->et)
                        {
                          // Check if they match in which case this
                          // cannot be the implicit default value. So
                          // start with a new value and try the whole loop
                          // again because our case labels may not be sorted.
                        case AST_Expression::EV_short:
                          if (this->default_value_.u.short_val
                                == expr->ev ()->u.sval)
                            {
                              this->default_value_.u.short_val++;
                              break_loop = 1;
                            }

                          break;
                        case AST_Expression::EV_ushort:
                          if (this->default_value_.u.ushort_val
                                == expr->ev ()->u.usval)
                            {
                              this->default_value_.u.ushort_val++;
                              break_loop = 1;
                            }

                          break;
                        case AST_Expression::EV_long:
                          if (this->default_value_.u.long_val
                                == expr->ev ()->u.lval)
                            {
                              this->default_value_.u.long_val++;
                              break_loop = 1;
                            }

                          break;
                        case AST_Expression::EV_ulong:
                          if (this->default_value_.u.ulong_val
                                == expr->ev ()->u.ulval)
                            {
                              this->default_value_.u.ulong_val++;
                              break_loop = 1;
                            }

                          break;
                        case AST_Expression::EV_char:
                          if (this->default_value_.u.char_val
                                == expr->ev ()->u.cval)
                            {
                              this->default_value_.u.char_val++;
                              break_loop = 1;
                            }

                          break;
                        case AST_Expression::EV_wchar:
                          if (this->default_value_.u.wchar_val
                                == expr->ev ()->u.wcval)
                            {
                              this->default_value_.u.wchar_val++;
                              break_loop = 1;
                            }

                          break;
                        case AST_Expression::EV_bool:
                          if (this->default_value_.u.bool_val
                                == expr->ev ()->u.bval)
                            {
                              this->default_value_.u.bool_val ^= true;
                              break_loop = 1;
                            }

                          break;
                        case AST_Expression::EV_enum:
                          // this is the case of enums. We maintain
                          // evaluated values which always start with 0
                          if (this->default_value_.u.enum_val
                                == expr->ev ()->u.eval)
                            {
                              this->default_value_.u.enum_val++;
                              break_loop = 1;
                            }

                          break;
                        case AST_Expression::EV_longlong:
                        case AST_Expression::EV_ulonglong:
                          // Unimplemented. right now - flag as error.
                        default:
                          // Error.
                          break;
                        } // End of switch.
                    } // if label_Kind == label
                } // End of for loop going thru all labels.
            } // If valid union branch.
        } // End of while scope iterator loop.

      // We have not aborted the inner loops which means we have found the
      // default value.
      if (break_loop == 0)
        {
          this->default_value_.computed_ = 1;
        }

    } // End of outer while (default_value.computed == -2).

  return 0;
}

// Private  operations.

// Compute the default index.
int
AST_Union::compute_default_index (void)
{
  AST_Decl *d = 0;
  AST_UnionBranch *ub = 0;
  int i = 0;

  // If default case does not exist, it will have a value of -1 according to
  // the spec.
  this->default_index_ = -1;

  // If there are elements in this scope...
  if (this->nmembers () > 0)
    {
      // Instantiate a scope iterator.
      for (UTL_ScopeActiveIterator si (this, UTL_Scope::IK_decls);
           !si.is_done ();
           si.next ())
        {
          // Get the next AST decl node.
          d = si.item ();

          // If an enum is declared in our scope, its members are
          // added to our scope as well, to detect clashes.
          if (d->node_type () == AST_Decl::NT_enum_val)
            {
              continue;
            }

          if (!d->imported ())
            {
              ub = AST_UnionBranch::narrow_from_decl (d);

              for (unsigned long j = 0; j < ub->label_list_length (); ++j)
                {
                  // Check if we are printing the default case.
                  AST_UnionLabel::UnionLabel ulk = ub->label ()->label_kind ();
                  if (ulk == AST_UnionLabel::UL_default)
                    {
                      // Zero based indexing.
                      this->default_index_ = i;
                    }
                }

              // TAO's Typecode class keeps only a member count (not
              // a label count) so this increment has been moved
              // out of the inner loop.
              ++i;
            }
        }
    }

  return 0;
}

// Redefinition of inherited virtual operations

// Add this AST_UnionBranch node (a node representing one branch in a
// union declaration) to this scope
AST_UnionBranch *
AST_Union::fe_add_union_branch (AST_UnionBranch *t)
{
  AST_Decl *d = 0;

  // If this is a malformed branch, don't do anything with it.
  if (t == 0 || t->label() == 0)
    {
      return 0;
    }

  // If branch with that label already exists, complain.
  if (lookup_branch (t) != 0)
    {
      idl_global->err ()->error2 (UTL_Error::EIDL_MULTIPLE_BRANCH,
                                  this,
                                  t);
      return 0;
    }

  // If branch with same field name exists, complain.
  if ((d = this->lookup_for_add (t, false)) != 0)
    {
      if (!can_be_redefined (d))
        {
          idl_global->err ()->error3 (UTL_Error::EIDL_REDEF,
                                      t,
                                      this,
                                      d);
          return 0;
        }

      if (this->referenced (d, t->local_name ()))
        {
          idl_global->err ()->error3 (UTL_Error::EIDL_DEF_USE,
                                      t,
                                      this,
                                      d);
          return 0;
        }

      if (t->has_ancestor (d))
        {
          idl_global->err ()->redefinition_in_scope (t,
                                                     d);
          return 0;
        }
    }

  // Add it to scope.
  this->add_to_scope (t);

  // If we have an enum discriminator, add the label names to
  // the name_referenced list before we add the union branch,
  // so a branch name clash with a label name will be caught.
  if (this->pd_udisc_type == AST_Expression::EV_enum)
    {
      t->add_labels (this);
    }

  // Add it to set of locally referenced symbols.
  this->add_to_referenced (t,
                           false,
                           t->local_name ());

  AST_Type *ft = t->field_type ();
  UTL_ScopedName *mru = ft->last_referenced_as ();

  if (mru != 0)
    {
      this->add_to_referenced (ft,
                               false,
                               mru->first_component ());
    }

  this->fields_.enqueue_tail (t);

  return t;
}

// Add this AST_Union (manifest union type) to this scope.
AST_Union *
AST_Union::fe_add_union (AST_Union *t)
{
  AST_Decl *d = 0;

  // Already defined and cannot be redefined? Or already used?
  if ((d = this->lookup_for_add (t, false)) != 0)
    {
      if (!can_be_redefined (d))
        {
          idl_global->err ()->error3 (UTL_Error::EIDL_REDEF,
                                      t,
                                      this,
                                      d);
          return 0;
        }

      if (this->referenced (d, t->local_name ()))
        {
          idl_global->err ()->error3 (UTL_Error::EIDL_DEF_USE,
                                      t,
                                      this,
                                      d);
          return 0;
        }

      if (t->has_ancestor (d))
        {
          idl_global->err ()->redefinition_in_scope (t,
                                                     d);
          return 0;
        }
    }

  // Add it to local types.
  this->add_to_local_types (t);

  // Add it to set of locally referenced symbols.
  this->add_to_referenced (t,
                           false,
                           t->local_name ());

  return t;
}

// Add this AST_Structure node (manifest struct type) to this scope.
AST_Structure *
AST_Union::fe_add_structure (AST_Structure *t)
{
  AST_Decl *d = 0;

  // Already defined and cannot be redefined? Or already used?
  if ((d = this->lookup_for_add (t, false)) != 0)
    {
      if (!can_be_redefined (d))
        {
          idl_global->err ()->error3 (UTL_Error::EIDL_REDEF,
                                      t,
                                      this,
                                      d);
          return 0;
        }

      if (this->referenced (d, t->local_name ()))
        {
          idl_global->err ()->error3 (UTL_Error::EIDL_DEF_USE,
                                      t,
                                      this,
                                      d);
          return 0;
        }

      if (t->has_ancestor (d))
        {
          idl_global->err ()->redefinition_in_scope (t,
                                                     d);
          return 0;
        }
    }

  // Add it to local types.
  this->add_to_local_types (t);

  // Add it to set of locally referenced symbols.
  this->add_to_referenced (t,
                           false,
                           t->local_name ());

  return t;
}

// Add this AST_Enum node (manifest enum type) to this scope.
AST_Enum *
AST_Union::fe_add_enum (AST_Enum *t)
{
  AST_Decl *d = 0;

  // Already defined and cannot be redefined? Or already used?
  if ((d = this->lookup_for_add (t, false)) != 0)
    {
      if (!can_be_redefined (d))
        {
          idl_global->err ()->error3 (UTL_Error::EIDL_REDEF,
                                      t,
                                      this,
                                      d);
          return 0;
        }

      if (this->referenced (d, t->local_name ()))
        {
          idl_global->err ()->error3 (UTL_Error::EIDL_DEF_USE,
                                      t,
                                      this,
                                      d);
          return 0;
        }

      if (t->has_ancestor (d))
        {
          idl_global->err ()->redefinition_in_scope (t,
                                                     d);
          return 0;
        }
    }

  // Add it to local types.
  this->add_to_local_types (t);

  // Add it to set of locally referenced symbols.
  this->add_to_referenced (t,
                           false,
                           t->local_name ());

  return t;
}

// Add this AST_EnumVal node (enumerator declaration) to this scope.
// This is done to conform to the C++ scoping rules which declare
// enumerators in the enclosing scope (in addition to declaring them
// in the enum itself).
AST_EnumVal *
AST_Union::fe_add_enum_val (AST_EnumVal *t)
{
  AST_Decl *d = 0;

  // Already defined and cannot be redefined? Or already used?
  if ((d = this->lookup_for_add (t, false)) != 0)
    {
      if (!can_be_redefined (d))
        {
          idl_global->err ()->error3 (UTL_Error::EIDL_REDEF,
                                      t,
                                      this,
                                      d);
          return 0;
        }

      if (this->referenced (d, t->local_name ()))
        {
          idl_global->err ()->error3 (UTL_Error::EIDL_DEF_USE,
                                      t,
                                      this,
                                      d);
          return 0;
        }

      if (t->has_ancestor (d))
        {
          idl_global->err ()->redefinition_in_scope (t,
                                                     d);
          return 0;
        }
    }

  // Add it to scope.
  this->add_to_scope (t);

  // Add it to set of locally referenced symbols.
  this->add_to_referenced (t,
                           false,
                           t->local_name ());

  return t;
}

// Dump this AST_Union node to the ostream o.
void
AST_Union::dump (ACE_OSTREAM_TYPE &o)
{
  o << "union ";
  this->local_name ()->dump (o);
  o << " switch (";
  this->pd_disc_type->local_name ()->dump (o);
  o << ") {\n";
  UTL_Scope::dump (o);
  idl_global->indent ()->skip_to (o);
  o << "}";
}

// Compute the size type of the node in question.
int
AST_Union::compute_size_type (void)
{
  for (UTL_ScopeActiveIterator si (this, UTL_Scope::IK_decls);
       !si.is_done ();
       si.next ())
    {
      // Get the next AST decl node.
      AST_Decl *d = si.item ();

      if (d->node_type () == AST_Decl::NT_enum_val)
        {
          continue;
        }

      AST_Field *f = AST_Field::narrow_from_decl (d);

      if (f != 0)
        {
          AST_Type *t = f->field_type ();
          // Our sizetype depends on the sizetype of our members. Although
          // previous value of sizetype may get overwritten, we are
          // guaranteed by the "size_type" call that once the value reached
          // be_decl::VARIABLE, nothing else can overwrite it.
          this->size_type (t->size_type ());
        }
      else
        {
          ACE_DEBUG ((LM_DEBUG,
                      "WARNING (%N:%l) be_union::compute_size_type - "
                      "narrow_from_decl returned 0\n"));
        }
    }

  return 0;
}

int
AST_Union::ast_accept (ast_visitor *visitor)
{
  return visitor->visit_union (this);
}

// Data accessors.

AST_ConcreteType *
AST_Union::disc_type (void)
{
  return this->pd_disc_type;
}

AST_Expression::ExprType
AST_Union::udisc_type (void)
{
  return this->pd_udisc_type;
}

// Narrowing.
IMPL_NARROW_METHODS1(AST_Union, AST_Structure)
IMPL_NARROW_FROM_DECL(AST_Union)
IMPL_NARROW_FROM_SCOPE(AST_Union)
