--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libinterp/corefcn/call-stack.h	Mon Jul 11 17:05:33 2016 -0400
@@ -0,0 +1,478 @@
+/*
+
+Copyright (C) 1993-2015 John W. Eaton
+
+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
+<http://www.gnu.org/licenses/>.
+
+*/
+
+#if ! defined (octave_call_stack_h)
+#define octave_call_stack_h 1
+
+#include "octave-config.h"
+
+#include <deque>
+#include <string>
+
+class octave_function;
+class octave_user_code;
+class octave_user_script;
+
+#include "input.h"
+#include "oct-map.h"
+#include "symtab.h"
+
+class
+OCTINTERP_API
+octave_call_stack
+{
+protected:
+
+  octave_call_stack (void) : cs (), curr_frame (0) { }
+
+public:
+
+  class stack_frame
+  {
+  public:
+
+    friend class octave_call_stack;
+
+    stack_frame (octave_function *fcn = 0, symbol_table::scope_id scope = 0,
+                 symbol_table::context_id context = 0, size_t prev = 0)
+      : m_fcn (fcn), m_line (-1), m_column (-1), m_scope (scope),
+        m_context (context), m_prev (prev)
+    { }
+
+    stack_frame (const stack_frame& elt)
+      : m_fcn (elt.m_fcn), m_line (elt.m_line), m_column (elt.m_column),
+        m_scope (elt.m_scope), m_context (elt.m_context), m_prev (elt.m_prev)
+    { }
+
+    int line (void) const { return m_line; }
+
+    int column (void) const { return m_column; }
+
+    std::string fcn_file_name (void) const;
+
+    std::string fcn_name (bool print_subfn = true) const;
+
+    bool operator== (const stack_frame &rhs) const;
+
+  private:
+
+    octave_function *m_fcn;
+    int m_line;
+    int m_column;
+    symbol_table::scope_id m_scope;
+    symbol_table::context_id m_context;
+    size_t m_prev;
+  };
+
+  typedef std::deque<stack_frame>::iterator iterator;
+  typedef std::deque<stack_frame>::const_iterator const_iterator;
+
+  typedef std::deque<stack_frame>::reverse_iterator reverse_iterator;
+  typedef std::deque<stack_frame>::const_reverse_iterator const_reverse_iterator;
+
+  static void create_instance (void);
+
+  static bool instance_ok (void)
+  {
+    bool retval = true;
+
+    if (! instance)
+      create_instance ();
+
+    if (! instance)
+      error ("unable to create call stack object!");
+
+    return retval;
+  }
+
+  // Current function (top of stack).
+  static octave_function *current (void)
+  {
+    return instance_ok () ? instance->do_current () : 0;
+  }
+
+  // Current line in current function.
+  static int current_line (void)
+  {
+    return instance_ok () ? instance->do_current_line () : -1;
+  }
+
+  // Current column in current function.
+  static int current_column (void)
+  {
+    return instance_ok () ? instance->do_current_column () : -1;
+  }
+
+  // Caller function, may be built-in.
+  static octave_function *caller (void)
+  {
+    return instance_ok () ? instance->do_caller () : 0;
+  }
+
+  static size_t current_frame (void)
+  {
+    return instance_ok () ? instance->do_current_frame () : 0;
+  }
+
+  static size_t size (void)
+  {
+    return instance_ok () ? instance->do_size () : 0;
+  }
+
+  static size_t num_user_code_frames (octave_idx_type& curr_user_frame)
+  {
+    return instance_ok ()
+           ? instance->do_num_user_code_frames (curr_user_frame) : 0;
+  }
+
+  static symbol_table::scope_id current_scope (void)
+  {
+    return instance_ok () ? instance->do_current_scope () : 0;
+  }
+
+  static symbol_table::context_id current_context (void)
+  {
+    return instance_ok () ? instance->do_current_context () : 0;
+  }
+
+#if 0
+  static stack_frame frame (size_t idx)
+  {
+    return instance_ok () ? instance->do_frame (idx) : stack_frame ();
+  }
+#endif
+
+  // Function at location N on the call stack (N == 0 is current), may
+  // be built-in.
+  static octave_function *element (size_t n)
+  {
+    return instance_ok () ? instance->do_element (n) : 0;
+  }
+
+  // User code caller.
+  static octave_user_code *caller_user_code (size_t nskip = 0)
+  {
+    return instance_ok () ? instance->do_caller_user_code (nskip) : 0;
+  }
+
+  // Line in user code caller.
+  static int caller_user_code_line (void)
+  {
+    return instance_ok () ? instance->do_caller_user_code_line () : -1;
+  }
+
+  // Column in user code caller.
+  static int caller_user_code_column (void)
+  {
+    return instance_ok () ? instance->do_caller_user_code_column () : -1;
+  }
+
+  // Current function that we are debugging.
+  static octave_user_code *debug_user_code (void)
+  {
+    return instance_ok () ? instance->do_debug_user_code () : 0;
+  }
+
+  // Line number in current function that we are debugging.
+  static int debug_user_code_line (void)
+  {
+    return instance_ok () ? instance->do_debug_user_code_line () : 0;
+  }
+
+  // Column number in current function that we are debugging.
+  static int debug_user_code_column (void)
+  {
+    return instance_ok () ? instance->do_debug_user_code_column () : 0;
+  }
+
+  // Return TRUE if all elements on the call stack are scripts.
+  static bool all_scripts (void)
+  {
+    return instance_ok () ? instance->do_all_scripts () : false;
+  }
+
+  static void
+  push (octave_function *f,
+        symbol_table::scope_id scope = symbol_table::current_scope (),
+        symbol_table::context_id context = symbol_table::current_context ())
+  {
+    if (instance_ok ())
+      instance->do_push (f, scope, context);
+  }
+
+  static void
+  push (symbol_table::scope_id scope = symbol_table::current_scope (),
+        symbol_table::context_id context = symbol_table::current_context ())
+  {
+    if (instance_ok ())
+      instance->do_push (0, scope, context);
+  }
+
+  static void set_location (int l, int c)
+  {
+    if (instance_ok ())
+      instance->do_set_location (l, c);
+  }
+
+  static void set_line (int l)
+  {
+    if (instance_ok ())
+      instance->do_set_line (l);
+  }
+
+  static void set_column (int c)
+  {
+    if (instance_ok ())
+      instance->do_set_column (c);
+  }
+
+  static bool goto_frame (size_t n = 0, bool verbose = false)
+  {
+    return instance_ok () ? instance->do_goto_frame (n, verbose) : false;
+  }
+
+  static void restore_frame (size_t n)
+  {
+    goto_frame (n);
+  }
+
+  static bool goto_frame_relative (int n, bool verbose = false)
+  {
+    return instance_ok ()
+           ? instance->do_goto_frame_relative (n, verbose) : false;
+  }
+
+  static void goto_caller_frame (void)
+  {
+    if (instance_ok ())
+      instance->do_goto_caller_frame ();
+  }
+
+  static void goto_base_frame (void)
+  {
+    if (instance_ok ())
+      instance->do_goto_base_frame ();
+  }
+
+  static octave_map backtrace (size_t nskip = 0)
+  {
+    octave_idx_type curr_user_frame = -1;
+
+    return instance_ok ()
+           ? instance->do_backtrace (nskip, curr_user_frame, true)
+           : octave_map ();
+  }
+
+  static octave_map backtrace (size_t nskip, octave_idx_type& curr_user_frame,
+                               bool print_subfn = true)
+  {
+    return instance_ok ()
+           ? instance->do_backtrace (nskip, curr_user_frame, print_subfn)
+           : octave_map ();
+  }
+
+  static std::list<octave_call_stack::stack_frame>
+  backtrace_frames (size_t nskip = 0)
+  {
+    octave_idx_type curr_user_frame = -1;
+
+    return instance_ok ()
+           ? instance->do_backtrace_frames (nskip, curr_user_frame)
+           : std::list<octave_call_stack::stack_frame> ();
+  }
+
+  static std::list<octave_call_stack::stack_frame>
+  backtrace_frames (size_t nskip, octave_idx_type& curr_user_frame)
+  {
+    return instance_ok ()
+           ? instance->do_backtrace_frames (nskip, curr_user_frame)
+           : std::list<octave_call_stack::stack_frame> ();
+  }
+
+  static octave_map empty_backtrace (void);
+
+  static void pop (void)
+  {
+    if (instance_ok ())
+      instance->do_pop ();
+  }
+
+  static void clear (void)
+  {
+    if (instance_ok ())
+      instance->do_clear ();
+  }
+
+private:
+
+  // The current call stack.
+  std::deque<stack_frame> cs;
+
+  size_t curr_frame;
+
+  static octave_call_stack *instance;
+
+  static void cleanup_instance (void) { delete instance; instance = 0; }
+
+  int do_current_line (void) const;
+
+  int do_current_column (void) const;
+
+  octave_function *do_caller (void) const
+  {
+    return curr_frame > 1 ? cs[curr_frame-1].m_fcn : cs[0].m_fcn;
+  }
+
+  size_t do_current_frame (void) { return curr_frame; }
+
+  size_t do_size (void) { return cs.size (); }
+
+  size_t do_num_user_code_frames (octave_idx_type& curr_user_frame) const;
+
+  symbol_table::scope_id do_current_scope (void) const
+  {
+    return curr_frame > 0 && curr_frame < cs.size ()
+           ? cs[curr_frame].m_scope : 0;
+  }
+
+  symbol_table::context_id do_current_context (void) const
+  {
+    return curr_frame > 0 && curr_frame < cs.size ()
+           ? cs[curr_frame].m_context : 0;
+  }
+
+#if 0
+  const stack_frame& do_frame (size_t idx)
+  {
+    static stack_frame foobar;
+
+    return idx < cs.size () ? cs[idx] : foobar;
+  }
+#endif
+
+  octave_function *do_element (size_t n)
+  {
+    octave_function *retval = 0;
+
+    if (cs.size () > n)
+      {
+        stack_frame& elt = cs[n];
+        retval = elt.m_fcn;
+      }
+
+    return retval;
+  }
+
+  octave_user_code *do_caller_user_code (size_t nskip) const;
+  int do_caller_user_code_line (void) const;
+  int do_caller_user_code_column (void) const;
+
+  octave_user_code *do_debug_user_code (void) const;
+  int do_debug_user_code_line (void) const;
+  int do_debug_user_code_column (void) const;
+
+  bool do_all_scripts (void) const;
+
+  void do_push (octave_function *fcn, symbol_table::scope_id scope,
+                symbol_table::context_id context)
+  {
+    size_t prev_frame = curr_frame;
+    curr_frame = cs.size ();
+    cs.push_back (stack_frame (fcn, scope, context, prev_frame));
+    symbol_table::set_scope_and_context (scope, context);
+  }
+
+  octave_function *do_current (void) const
+  {
+    octave_function *retval = 0;
+
+    if (! cs.empty ())
+      {
+        const stack_frame& elt = cs[curr_frame];
+        retval = elt.m_fcn;
+      }
+
+    return retval;
+  }
+
+  void do_set_location (int l, int c)
+  {
+    if (! cs.empty ())
+      {
+        stack_frame& elt = cs.back ();
+
+        elt.m_line = l;
+        elt.m_column = c;
+      }
+  }
+
+  void do_set_line (int l)
+  {
+    if (! cs.empty ())
+      {
+        stack_frame& elt = cs.back ();
+
+        elt.m_line = l;
+      }
+  }
+
+  void do_set_column (int c)
+  {
+    if (! cs.empty ())
+      {
+        stack_frame& elt = cs.back ();
+
+        elt.m_column = c;
+      }
+  }
+
+  std::list<octave_call_stack::stack_frame>
+  do_backtrace_frames (size_t nskip, octave_idx_type& curr_user_frame) const;
+
+  octave_map do_backtrace (size_t nskip,
+                           octave_idx_type& curr_user_frame,
+                           bool print_subfn) const;
+
+  bool do_goto_frame (size_t n, bool verbose);
+
+  bool do_goto_frame_relative (int n, bool verbose);
+
+  void do_goto_caller_frame (void);
+
+  void do_goto_base_frame (void);
+
+  void do_pop (void)
+  {
+    if (cs.size () > 1)
+      {
+        const stack_frame& elt = cs.back ();
+        curr_frame = elt.m_prev;
+        cs.pop_back ();
+        const stack_frame& new_elt = cs[curr_frame];
+        symbol_table::set_scope_and_context (new_elt.m_scope, new_elt.m_context);
+      }
+  }
+
+  void do_clear (void) { cs.clear (); }
+};
+
+#endif