/* -*-C-*-

$Id: error.c,v 1.12 2007/01/05 21:19:25 cph Exp $

Copyright (C) 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994,
    1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
    2006, 2007 Massachusetts Institute of Technology

This file is part of MIT/GNU Scheme.

MIT/GNU Scheme 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.

MIT/GNU Scheme 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 MIT/GNU Scheme; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301,
USA.

*/

#include <stdio.h>
#include "outf.h"
#include "dstack.h"

static PTR
DEFUN (xmalloc, (length), unsigned int length)
{
#if defined(__linux__) || defined(__APPLE__) || defined(__netbsd__)
#else
  extern PTR EXFUN (malloc, (unsigned int length));
#endif

  PTR result = (malloc (length));
  if (result == 0)
    {
      outf_fatal ("malloc: memory allocation failed\n");
      outf_flush_fatal ();
      abort ();
    }
  return (result);
}

struct handler_record
{
  struct handler_record * next;
  Tcondition_type type;
  void EXFUN ((*handler), (Tcondition));
};

struct restart_record
{
  struct restart_record * next;
  struct condition_restart contents;
};

static unsigned long next_condition_type_index;
static struct handler_record * current_handler_record;
static struct restart_record * current_restart_record;

void
DEFUN_VOID (initialize_condition_system)
{
  next_condition_type_index = 0;
  current_handler_record = 0;
  current_restart_record = 0;
}

Tcondition_type
DEFUN (condition_type_allocate, (name, generalizations, reporter),
       PTR name AND
       Tptrvec generalizations AND
       void EXFUN ((*reporter), (Tcondition condition)))
{
  Tptrvec EXFUN (generalizations_union, (Tptrvec generalizations));
  Tcondition_type type = (xmalloc (sizeof (struct condition_type)));
  Tptrvec g = (generalizations_union (generalizations));
  ptrvec_adjoin (g, type);
  (CONDITION_TYPE_INDEX (type)) = (next_condition_type_index++);
  (CONDITION_TYPE_NAME (type)) = name;
  (CONDITION_TYPE_GENERALIZATIONS (type)) = g;
  (CONDITION_TYPE_REPORTER (type)) = reporter;
  return (type);
}

void
DEFUN (condition_type_deallocate, (type), Tcondition_type type)
{
  ptrvec_deallocate (CONDITION_TYPE_GENERALIZATIONS (type));
  free (type);
}

Tcondition
DEFUN (condition_allocate, (type, irritants),
       Tcondition_type type AND
       Tptrvec irritants)
{
  Tcondition condition = (xmalloc (sizeof (struct condition)));
  (CONDITION_TYPE (condition)) = type;
  (CONDITION_IRRITANTS (condition)) = irritants;
  return (condition);
}

void
DEFUN (condition_deallocate, (condition), Tcondition condition)
{
  ptrvec_deallocate (CONDITION_IRRITANTS (condition));
  free (condition);
}

static Tptrvec
DEFUN (generalizations_union_2, (x, y), Tptrvec x AND Tptrvec y)
{
  PTR * scan_x = (PTRVEC_START (x));
  PTR * end_x = (scan_x + (PTRVEC_LENGTH (x)));
  PTR * scan_y = (PTRVEC_START (y));
  PTR * end_y = (scan_y + (PTRVEC_LENGTH (y)));
  Tptrvec_length length = 0;
  unsigned long ix;
  unsigned long iy;
  Tptrvec result;
  PTR * scan_result;
  while (1)
    {
      if (scan_x == end_x)
	{
	  length += (end_y - scan_y);
	  break;
	}
      if (scan_y == end_y)
	{
	  length += (end_x - scan_x);
	  break;
	}
      length += 1;
      ix = (CONDITION_TYPE_INDEX ((Tcondition_type) (*scan_x)));
      iy = (CONDITION_TYPE_INDEX ((Tcondition_type) (*scan_y)));
      if (ix <= iy) scan_x += 1;
      if (iy <= ix) scan_y += 1;
    }
  result = (ptrvec_allocate (length));
  scan_result = (PTRVEC_START (result));
  while (1)
    {
      if (scan_x == end_x)
	{
	  while (scan_y < end_y) (*scan_result++) = (*scan_y++);
	  break;
	}
      if (scan_y == end_y)
	{
	  while (scan_x < end_x) (*scan_result++) = (*scan_x++);
	  break;
	}
      ix = (CONDITION_TYPE_INDEX ((Tcondition_type) (*scan_x)));
      iy = (CONDITION_TYPE_INDEX ((Tcondition_type) (*scan_y)));
      if (ix == iy)
	{
	  (*scan_result++) = (*scan_x++);
	  scan_y += 1;
	}
      else
	(*scan_result++) = ((ix < iy) ? (*scan_x++) : (*scan_y++));
    }
  return (result);
}

Tptrvec
DEFUN (generalizations_union, (generalizations), Tptrvec generalizations)
{
  Tptrvec_length length = (PTRVEC_LENGTH (generalizations));
  if (length == 0)
    return (ptrvec_allocate (0));
  if (length == 1)
    return (ptrvec_copy (PTRVEC_REF (generalizations, 0)));
  {
    PTR * scan = (PTRVEC_START (generalizations));
    PTR * end = (scan + length);
    Tptrvec result = ((Tptrvec) (*scan++));
    result = (generalizations_union_2 (result, ((Tptrvec) (*scan++))));
    while (scan < end)
      {
	Tptrvec v = (generalizations_union_2 (result, ((Tptrvec) (*scan++))));
	ptrvec_deallocate (result);
	result = v;
      }
    return (result);
  }
}

void
DEFUN (condition_handler_bind, (type, handler),
       Tcondition_type type AND
       void EXFUN ((*handler), (Tcondition condition)))
{
  struct handler_record * record =
    (dstack_alloc (sizeof (struct handler_record)));
  (record -> next) = current_handler_record;
  (record -> type) = type;
  (record -> handler) = handler;
  dstack_bind ((&current_handler_record), record);
}

#define GENERALIZATIONS(condition)					\
  (CONDITION_TYPE_GENERALIZATIONS (CONDITION_TYPE (condition)))

void
DEFUN (condition_signal, (condition), Tcondition condition)
{
  Tptrvec generalizations = (GENERALIZATIONS (condition));
  struct handler_record * record = current_handler_record;
  while (record != 0)
    {
      Tcondition_type type = (record -> type);
      if ((type == 0) || (ptrvec_memq (generalizations, type)))
	{
	  PTR position = dstack_position;
	  dstack_bind ((&current_handler_record), (record -> next));
	  (* (record -> handler)) (condition);
	  dstack_set_position (position);
	}
      record = (record -> next);
    }
}

void
DEFUN (condition_restart_bind, (name, type, procedure),
       PTR name AND
       Tcondition_type type AND
       void EXFUN ((*procedure), (PTR argument)))
{
  struct restart_record * record =
    (dstack_alloc (sizeof (struct restart_record)));
  (record -> next) = current_restart_record;
  (record -> contents . name) = name;
  (record -> contents . type) = type;
  (record -> contents . procedure) = procedure;
  dstack_bind ((&current_restart_record), record);
}

Tcondition_restart
DEFUN (condition_restart_find, (name, condition),
       PTR name AND
       Tcondition condition)
{
  struct restart_record * record = current_restart_record;
  if (condition == 0)
    while (record != 0)
      {
	if ((record -> contents . name) == name)
	  return (& (record -> contents));
	record = (record -> next);
      }
  else
    {
      Tptrvec generalizations = (GENERALIZATIONS (condition));
      while (record != 0)
	{
	  if (((record -> contents . name) == name) &&
	      (ptrvec_memq (generalizations, (record -> contents . type))))
	    return (& (record -> contents));
	  record = (record -> next);
	}
    }
  return (0);
}

Tptrvec
DEFUN (condition_restarts, (condition), Tcondition condition)
{
  struct restart_record * record = current_restart_record;
  Tptrvec_length length = 0;
  Tptrvec generalizations = 0;
  Tptrvec result;
  PTR * scan_result;
  if (condition == 0)
    while (record != 0)
      {
	length += 1;
	record = (record -> next);
      }
  else
    {
      generalizations = (GENERALIZATIONS (condition));
      while (record != 0)
	{
	  if (ptrvec_memq (generalizations, (record -> contents . type)))
	    length += 1;
	  record = (record -> next);
	}
    }
  result = (ptrvec_allocate (length));
  scan_result = (PTRVEC_START (result));
  record = current_restart_record;
  if (condition == 0)
    while (record != 0)
      {
	(*scan_result++) = (& (record -> contents));
	record = (record -> next);
      }
  else
    while (record != 0)
      {
	if (ptrvec_memq (generalizations, (record -> contents . type)))
	  (*scan_result++) = (& (record -> contents));
	record = (record -> next);
      }
  return (result);
}
