stackframe.cc

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/*
 *  stackframe.cc - a usecode interpreter stack frame
 *
 *  Copyright (C) 2002  The Exult Team
 *
 *  This program 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 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program 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 this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

#ifdef HAVE_CONFIG_H
#  include <config.h>
#endif

#include <iostream>
#include <iomanip>

#include "stackframe.h"
#include "useval.h"
#include "ucinternal.h"
#include "utils.h"
#include "ucfunction.h"


int Stack_frame::LastCallChainID = 0;

Stack_frame::Stack_frame(Usecode_function *fun,
             int event,
             Game_object *caller,
             int chain, int depth)
  : function(fun), ip(0), data(0), externs(0), code(0), endp(0),
    line_number(-1), call_chain(chain), call_depth(depth), 
    num_externs(0), num_args(0), num_vars(0), locals(0), eventid(event),
    caller_item(caller), save_sp(0)
{
  ip = function->code;
  endp = ip + function->len;
  
  int data_len;
  if (!fun->extended)
    data_len = Read2(ip); // Get length of (text) data.
  else
    data_len = (sint32)(Read4(ip)); // 32 bit lengths

  data = ip;

  ip += data_len;     // Point past text.
  num_args = Read2(ip); // # of args. this function takes.

  // Local variables follow args.
  num_vars = Read2(ip);

  // Allocate locals.
  int num_locals = num_vars + num_args;
  locals = new Usecode_value[num_locals];

  num_externs = Read2(ip); // external function references
  externs = ip;

  ip += 2 * num_externs; // now points to actual code

  code = ip;
}

Stack_frame::~Stack_frame()
{
  delete[] locals;
}

std::ostream& operator<<(std::ostream& out, Stack_frame& frame)
{
  // #depth: 0xIP in 0xfunid ( obj=..., event=..., arguments )

  // TODO: include any debugging info
  // #depth: 0xIP in functionname (obj=...,event=..., arg1name=..., ...)

  out << "#" << frame.call_depth << ": 0x" 
    << std::hex << std::setw(4) << std::setfill('0')
    << (int)(frame.ip - frame.code) << " in 0x"
    << std::setw(4) << frame.function->id
    << "(obj=" << std::setw(8) << (long)frame.caller_item
    << ",ev=" << frame.eventid
    << std::setfill(' ') << std::dec;
  
  for (int i=0; i < frame.num_args; i++)
    out << ", " << frame.locals[i];

  out << ")";

  return out;
}

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