/* Register support routines for the remote server for GDB.
   Copyright 2001, 2002, 2004
   Free Software Foundation, Inc.

   This file is part of GDB.

   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.  */

#include "server.h"
#include "regdef.h"

#include <stdlib.h>
#include <string.h>

/* The private data for the register cache.  Note that we have one
   per inferior; this is primarily for simplicity, as the performance
   benefit is minimal.  */

struct inferior_regcache_data
{
  int registers_valid;
  char *registers;
};

static int register_bytes;

static struct reg *reg_defs;
static int num_registers;

const char **gdbserver_expedite_regs;

static struct inferior_regcache_data *
get_regcache (struct thread_info *inf, int fetch)
{
  struct inferior_regcache_data *regcache;

  regcache = (struct inferior_regcache_data *) inferior_regcache_data (inf);

  if (regcache == NULL)
    fatal ("no register cache");

  /* FIXME - fetch registers for INF */
  if (fetch && regcache->registers_valid == 0)
    {
      fetch_inferior_registers (0);
      regcache->registers_valid = 1;
    }

  return regcache;
}

void
regcache_invalidate_one (struct inferior_list_entry *entry)
{
  struct thread_info *thread = (struct thread_info *) entry;
  struct inferior_regcache_data *regcache;

  regcache = (struct inferior_regcache_data *) inferior_regcache_data (thread);

  if (regcache->registers_valid)
    {
      struct thread_info *saved_inferior = current_inferior;

      current_inferior = thread;
      store_inferior_registers (-1);
      current_inferior = saved_inferior;
    }

  regcache->registers_valid = 0;
}

void
regcache_invalidate ()
{
  for_each_inferior (&all_threads, regcache_invalidate_one);
}

int
registers_length (void)
{
  return 2 * register_bytes;
}

void *
new_register_cache (void)
{
  struct inferior_regcache_data *regcache;

  regcache = malloc (sizeof (*regcache));

  /* Make sure to zero-initialize the register cache when it is created,
     in case there are registers the target never fetches.  This way they'll
     read as zero instead of garbage.  */
  regcache->registers = calloc (1, register_bytes);
  if (regcache->registers == NULL)
    fatal ("Could not allocate register cache.");

  regcache->registers_valid = 0;

  return regcache;
}

void
free_register_cache (void *regcache_p)
{
  struct inferior_regcache_data *regcache
    = (struct inferior_regcache_data *) regcache_p;

  free (regcache->registers);
  free (regcache);
}

void
set_register_cache (struct reg *regs, int n)
{
  int offset, i;
  
  reg_defs = regs;
  num_registers = n;

  offset = 0;
  for (i = 0; i < n; i++)
    {
      regs[i].offset = offset;
      offset += regs[i].size;
    }

  register_bytes = offset / 8;
}

void
registers_to_string (char *buf)
{
  char *registers = get_regcache (current_inferior, 1)->registers;

  convert_int_to_ascii (registers, buf, register_bytes);
}

void
registers_from_string (char *buf)
{
  int len = strlen (buf);
  char *registers = get_regcache (current_inferior, 1)->registers;

  if (len != register_bytes * 2)
    {
      warning ("Wrong sized register packet (expected %d bytes, got %d)", 2*register_bytes, len);
      if (len > register_bytes * 2)
	len = register_bytes * 2;
    }
  convert_ascii_to_int (buf, registers, len / 2);
}

struct reg *
find_register_by_name (const char *name)
{
  int i;

  for (i = 0; i < num_registers; i++)
    if (!strcmp (name, reg_defs[i].name))
      return &reg_defs[i];
  fatal ("Unknown register %s requested", name);
  return 0;
}

int
find_regno (const char *name)
{
  int i;

  for (i = 0; i < num_registers; i++)
    if (!strcmp (name, reg_defs[i].name))
      return i;
  fatal ("Unknown register %s requested", name);
  return -1;
}

struct reg *
find_register_by_number (int n)
{
  return &reg_defs[n];
}

int
register_size (int n)
{
  return reg_defs[n].size / 8;
}

static char *
register_data (int n, int fetch)
{
  char *registers = get_regcache (current_inferior, fetch)->registers;

  return registers + (reg_defs[n].offset / 8);
}

void
supply_register (int n, const void *buf)
{
  memcpy (register_data (n, 0), buf, register_size (n));
}

void
supply_register_by_name (const char *name, const void *buf)
{
  supply_register (find_regno (name), buf);
}

void
collect_register (int n, void *buf)
{
  memcpy (buf, register_data (n, 1), register_size (n));
}

void
collect_register_as_string (int n, char *buf)
{
  convert_int_to_ascii (register_data (n, 1), buf, register_size (n));
}

void
collect_register_by_name (const char *name, void *buf)
{
  collect_register (find_regno (name), buf);
}