pt-anon-scopes.cc

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//
// Copyright (C) 1996-2024 The Octave Project Developers
//
// See the file COPYRIGHT.md in the top-level directory of this
// distribution or <https://octave.org/copyright/>.
//
// This file is part of Octave.
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////////////////////////////////////////////////////////////////////////
 
#ifdef HAVE_CONFIG_H
#  include "config.h"
#endif
 
#include "error.h"
#include "pt-all.h"
#include "pt-anon-scopes.h"
 
// TODO: make sure that if(f->scope()) is checked if necessary
 
OCTAVE_BEGIN_NAMESPACE(octave)
 
tree_anon_scopes::tree_anon_scopes (tree_anon_fcn_handle& anon_fh)
  : tree_walker (), m_params (), m_vars ()
{
  visit_anon_fcn_handle (anon_fh);
}
 
void
tree_anon_scopes::visit_anon_fcn_handle (tree_anon_fcn_handle& afh)
{
  tree_parameter_list *param_list = afh.parameter_list ();
  tree_expression *expr = afh.expression ();
 
  // Collect names of parameters.
 
  if (param_list)
    {
      std::list<std::string> pnames = param_list->variable_names ();
 
      for (const auto& nm : pnames)
        m_params.insert (nm);
 
      // Hmm, should this be included in the list returned from
      // tree_parameter_list::variable_names?
      if (param_list->takes_varargs ())
        m_params.insert ("varargin");
    }
 
  // Further walk the tree to find free variables in this expression
  // and any nested definitions of additional anonymous functions.
 
  if (expr)
    expr->accept (*this);
}
 
// The rest of visit_... methods is only for walking the tree.  Many of
// them, in particular all methods for commands, are not applicable to
// anonymous functions.  Only parts of the tree are walked which could
// contain further (nested) anonymous function definitions (so
// e.g. identifiers and left hand sides of assignments are ignored).
 
void
tree_anon_scopes::visit_identifier (tree_identifier& id)
{
  std::string nm = id.name ();
 
  if (m_params.find (nm) == m_params.end ())
    m_vars.insert (nm);
}
 
void
tree_anon_scopes::visit_parameter_list (tree_parameter_list&)
{
  // In visit_anon_fcn_handle we only accept/visit the body of
  // anonymous function definitions, not the parameter list.
 
  panic_impossible ();
}
 
void
tree_anon_scopes::visit_statement (tree_statement& stmt)
{
  tree_command *cmd = stmt.command ();
 
  if (cmd)
    panic_impossible ();
  else
    {
      tree_expression *expr = stmt.expression ();
 
      if (expr)
        expr->accept (*this);
    }
}
 
void
tree_anon_scopes::visit_statement_list (tree_statement_list& lst)
{
  for (auto& p : lst)
    {
      tree_statement *elt = p;
 
      if (elt)
        elt->accept (*this);
    }
}
 
OCTAVE_END_NAMESPACE(octave)