binutils-gdb/gdb/gdbserver/regcache.c

/* Register support routines for the remote server for GDB.
   Copyright (C) 2001, 2002, 2004, 2005, 2007, 2008, 2009, 2010, 2011
   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 3 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, see <http://www.gnu.org/licenses/>.  */

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

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

static int register_bytes;

static struct reg *reg_defs;
static int num_registers;

const char **gdbserver_expedite_regs;

#ifndef IN_PROCESS_AGENT

struct regcache *
get_thread_regcache (struct thread_info *thread, int fetch)
{
  struct regcache *regcache;

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

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

  if (fetch && regcache->registers_valid == 0)
    {
      struct thread_info *saved_inferior = current_inferior;

      current_inferior = thread;
      fetch_inferior_registers (regcache, -1);
      current_inferior = saved_inferior;
      regcache->registers_valid = 1;
    }

  return regcache;
}

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

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

  if (regcache == NULL)
    return;

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

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

  regcache->registers_valid = 0;
}

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

#endif

struct regcache *
init_register_cache (struct regcache *regcache, unsigned char *regbuf)
{
#ifndef IN_PROCESS_AGENT
  if (regbuf == NULL)
    {
      /* 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 = xcalloc (1, register_bytes);
      regcache->registers_owned = 1;
    }
  else
#else
  if (regbuf == NULL)
    fatal ("init_register_cache: can't allocate memory from the heap");
  else
#endif
    {
      regcache->registers = regbuf;
      regcache->registers_owned = 0;
    }

  regcache->registers_valid = 0;

  return regcache;
}

#ifndef IN_PROCESS_AGENT

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

  if (register_bytes == 0)
    return NULL; /* The architecture hasn't been initialized yet.  */

  regcache = xmalloc (sizeof (*regcache));
  return init_register_cache (regcache, NULL);
}

void
free_register_cache (struct regcache *regcache)
{
  if (regcache)
    {
      if (regcache->registers_owned)
	free (regcache->registers);
      free (regcache);
    }
}

#endif

void
regcache_cpy (struct regcache *dst, struct regcache *src)
{
  memcpy (dst->registers, src->registers, register_bytes);
  dst->registers_valid = src->registers_valid;
}

#ifndef IN_PROCESS_AGENT
static void
realloc_register_cache (struct inferior_list_entry *thread_p)
{
  struct thread_info *thread = (struct thread_info *) thread_p;
  struct regcache *regcache
    = (struct regcache *) inferior_regcache_data (thread);

  if (regcache != NULL)
    regcache_invalidate_one (thread_p);
  free_register_cache (regcache);
  set_inferior_regcache_data (thread, new_register_cache ());
}
#endif

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

#ifndef IN_PROCESS_AGENT
  /* Before changing the register cache internal layout, flush the
     contents of valid caches back to the threads.  */
  regcache_invalidate ();
#endif

  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;

  /* Make sure PBUFSIZ is large enough to hold a full register packet.  */
  if (2 * register_bytes + 32 > PBUFSIZ)
    fatal ("Register packet size exceeds PBUFSIZ.");

#ifndef IN_PROCESS_AGENT
  /* Re-allocate all pre-existing register caches.  */
  for_each_inferior (&all_threads, realloc_register_cache);
#endif
}

int
register_cache_size (void)
{
  return register_bytes;
}

#ifndef IN_PROCESS_AGENT

void
registers_to_string (struct regcache *regcache, char *buf)
{
  unsigned char *registers = regcache->registers;

  convert_int_to_ascii (registers, buf, register_bytes);
}

void
registers_from_string (struct regcache *regcache, char *buf)
{
  int len = strlen (buf);
  unsigned char *registers = regcache->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];
}

#endif

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

static unsigned char *
register_data (struct regcache *regcache, int n, int fetch)
{
  return regcache->registers + (reg_defs[n].offset / 8);
}

void
supply_register (struct regcache *regcache, int n, const void *buf)
{
  if (buf)
    memcpy (register_data (regcache, n, 0), buf, register_size (n));
  else
    memset (register_data (regcache, n, 0), 0, register_size (n));
}

void
supply_regblock (struct regcache *regcache, const void *buf)
{
  if (buf)
    memcpy (regcache->registers, buf, register_bytes);
  else
    memset (regcache->registers, 0, register_bytes);
}

#ifndef IN_PROCESS_AGENT

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

#endif

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

#ifndef IN_PROCESS_AGENT

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

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

/* Special handling for register PC.  */

CORE_ADDR
regcache_read_pc (struct regcache *regcache)
{
  CORE_ADDR pc_val;

  if (the_target->read_pc)
    pc_val = the_target->read_pc (regcache);
  else
    internal_error (__FILE__, __LINE__,
		    "regcache_read_pc: Unable to find PC");

  return pc_val;
}

void
regcache_write_pc (struct regcache *regcache, CORE_ADDR pc)
{
  if (the_target->write_pc)
    the_target->write_pc (regcache, pc);
  else
    internal_error (__FILE__, __LINE__,
		    "regcache_write_pc: Unable to update PC");
}

#endif