symscope.cc

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/*

Copyright (C) 1993-2018 John W. Eaton
Copyright (C) 2009 VZLU Prague, a.s.

This file is part of Octave.

Octave is free software: you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

Octave is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with Octave; see the file COPYING.  If not, see
<https://www.gnu.org/licenses/>.

*/

#if defined (HAVE_CONFIG_H)
#  include "config.h"
#endif

#include <sstream>

#include "fcn-info.h"
#include "interpreter-private.h"
#include "interpreter.h"
#include "ov-fcn.h"
#include "ov-usr-fcn.h"
#include "symrec.h"
#include "symscope.h"
#include "symtab.h"
#include "utils.h"

namespace octave
{
  octave_value
  symbol_scope_rep::find (const std::string& name,
                          const octave_value_list& args,
                          bool skip_variables, bool local_funcs)
  {
    // Variable.

    symbol_table& symtab
      = __get_symbol_table__ ("symbol_scope_rep::find");

    if (! skip_variables)
      {
        table_iterator p = m_symbols.find (name);

        if (p != m_symbols.end ())
          {
            symbol_record sr = p->second;

            if (sr.is_global ())
              return symtab.global_varval (name);
            else
              {
                octave_value val = sr.varval (m_context);

                if (val.is_defined ())
                  return val;
              }
          }
      }

    if (local_funcs)
      {
        // Subfunction.  I think it only makes sense to check for
        // subfunctions if we are currently executing a function defined
        // from a .m file.

        octave_value fcn = find_subfunction (name);

        if (fcn.is_defined ())
          return fcn;
      }

    return symtab.fcn_table_find (name, args, local_funcs);
  }

  symbol_record&
  symbol_scope_rep::insert (const std::string& name, bool force_add)
  {
    table_iterator p = m_symbols.find (name);

    if (p == m_symbols.end ())
      {
        symbol_record ret (name);

        auto t_parent = m_parent.lock ();

        if (m_is_nested && t_parent && t_parent->look_nonlocal (name, ret))
          return m_symbols[name] = ret;
        else
          {
            if (m_is_static && ! force_add)
              ret.mark_added_static ();

            return m_symbols[name] = ret;
          }
      }
    else
      return p->second;
  }

  octave_value
  symbol_scope_rep::dump (void) const
  {
    std::map<std::string, octave_value> m
      = {{ "name", m_name },
         { "symbols", dump_symbols_map () },
         { "subfunctions", dump_function_map (m_subfunctions) }};

    return octave_value (m);
  }

  octave_value
  symbol_scope_rep::dump_symbols_map (void) const
  {
    std::map<std::string, octave_value> info_map;

    for (const auto& nm_sr : m_symbols)
      {
        std::string nm = nm_sr.first;
        const symbol_record& sr = nm_sr.second;
        info_map[nm] = sr.dump (m_context);
      }

    return octave_value (info_map);
  }

  octave_value
  symbol_scope_rep::find_subfunction (const std::string& name) const
  {
    subfunctions_const_iterator p = m_subfunctions.find (name);

    if (p != m_subfunctions.end ())
      return p->second;

    auto t_parent = m_parent.lock ();

    if (t_parent)
      return t_parent->find_subfunction (name);

    return octave_value ();
  }

  void
  symbol_scope_rep::mark_subfunctions_in_scope_as_private (const std::string& class_name)
  {
    for (auto& nm_sf : m_subfunctions)
      {
        octave_function *fcn = nm_sf.second.function_value ();

        if (fcn)
          fcn->mark_as_private_function (class_name);
      }
  }

  void
  symbol_scope_rep::set_parent (const std::shared_ptr<symbol_scope_rep>& parent)
  {
    m_parent = std::weak_ptr<symbol_scope_rep> (parent);
  }

  void
  symbol_scope_rep::update_nest (void)
  {
    auto t_parent = m_parent.lock ();

    if (t_parent)
      {
        // fix bad symbol_records
        for (auto& nm_sr : m_symbols)
          {
            symbol_record& ours = nm_sr.second;

            if (! ours.is_formal ()
                && m_is_nested && t_parent->look_nonlocal (nm_sr.first, ours))
              {
                if (ours.is_global () || ours.is_persistent ())
                  error ("global and persistent may only be used in the topmost level in which a nested variable is used");
              }
          }

        // The scopes of nested functions are static.
        if (m_is_nested)
          m_is_static = true;
      }
    else if (m_children.size ())
      {
        // Parents of nested functions have static scopes.
        m_is_static = true;
      }

    for (auto& scope_obj : m_children)
      scope_obj.update_nest ();
  }

  bool
  symbol_scope_rep::look_nonlocal (const std::string& name,
                                   symbol_record& result)
  {
    table_iterator p = m_symbols.find (name);
    if (p == m_symbols.end ())
      {
        auto t_parent = m_parent.lock ();

        if (m_is_nested && t_parent)
          return t_parent->look_nonlocal (name, result);
      }
    else if (! p->second.is_automatic ())
      {
        result.bind_fwd_rep (shared_from_this (), p->second);
        return true;
      }

    return false;
  }

  void
  symbol_scope_rep::bind_script_symbols
    (const std::shared_ptr<symbol_scope_rep>& curr_scope)
  {
    for (auto& nm_sr : m_symbols)
      nm_sr.second.bind_fwd_rep (curr_scope,
                                 curr_scope->find_symbol (nm_sr.first));
  }

  void
  symbol_scope_rep::unbind_script_symbols (void)
  {
    for (auto& nm_sr : m_symbols)
      nm_sr.second.unbind_fwd_rep ();
  }
}