/* Machine-independent I/O routines for gcov.
   Copyright (C) 1996, 1997, 1998, 2000 Free Software Foundation, Inc.
   Contributed by Bob Manson <manson@cygnus.com>.

This file is part of GCC.

GCC 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, or (at your option) any later
version.

GCC 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 GCC; see the file COPYING.  If not, write to the Free
Software Foundation, 59 Temple Place - Suite 330, Boston, MA
02111-1307, USA.  */

#ifndef GCC_GCOV_IO_H
#define GCC_GCOV_IO_H
#include <stdio.h>
#include <sys/types.h>

static int __fetch_long	PARAMS ((long *, char *, size_t)) ATTRIBUTE_UNUSED;
static int __read_long  PARAMS ((long *, FILE *, size_t)) ATTRIBUTE_UNUSED;
static int __write_long PARAMS ((long, FILE *, size_t)) ATTRIBUTE_UNUSED;
static int __fetch_gcov_type PARAMS ((gcov_type *, char *, size_t)) ATTRIBUTE_UNUSED;
static int __store_gcov_type PARAMS ((gcov_type, char *, size_t)) ATTRIBUTE_UNUSED;
static int __read_gcov_type  PARAMS ((gcov_type *, FILE *, size_t)) ATTRIBUTE_UNUSED;
static int __write_gcov_type PARAMS ((gcov_type, FILE *, size_t)) ATTRIBUTE_UNUSED;

/* These routines only work for signed values.  */

/* Store a portable representation of VALUE in DEST using BYTES*8-1 bits.
   Return a non-zero value if VALUE requires more than BYTES*8-1 bits
   to store.  */

static int
__store_gcov_type (value, dest, bytes)
     gcov_type value;
     char *dest;
     size_t bytes;
{
  int upper_bit = (value < 0 ? 128 : 0);
  size_t i;

  if (value < 0)
    {
      gcov_type oldvalue = value;
      value = -value;
      if (oldvalue != -value)
	return 1;
    }

  for(i = 0 ; i < (sizeof (value) < bytes ? sizeof (value) : bytes) ; i++) {
    dest[i] = value & (i == (bytes - 1) ? 127 : 255);
    value = value / 256;
  }

  if (value && value != -1)
    return 1;

  for(; i < bytes ; i++) 
    dest[i] = 0;
  dest[bytes - 1] |= upper_bit;
  return 0;
}

/* Retrieve a quantity containing BYTES*8-1 bits from SOURCE and store
   the result in DEST. Returns a non-zero value if the value in SOURCE
   will not fit in DEST.  */

static int
__fetch_gcov_type (dest, source, bytes)
     gcov_type *dest;
     char *source;
     size_t bytes;
{
  gcov_type value = 0;
  int i;

  for (i = bytes - 1; (size_t) i > (sizeof (*dest) - 1); i--)
    if (source[i] & ((size_t) i == (bytes - 1) ? 127 : 255 ))
      return 1;

  for (; i >= 0; i--)
    value = value * 256 + (source[i] & ((size_t)i == (bytes - 1) ? 127 : 255));

  if ((source[bytes - 1] & 128) && (value > 0))
    value = - value;

  *dest = value;
  return 0;
}

static int
__fetch_long (dest, source, bytes)
     long *dest;
     char *source;
     size_t bytes;
{
  long value = 0;
  int i;

  for (i = bytes - 1; (size_t) i > (sizeof (*dest) - 1); i--)
    if (source[i] & ((size_t) i == (bytes - 1) ? 127 : 255 ))
      return 1;

  for (; i >= 0; i--)
    value = value * 256 + (source[i] & ((size_t)i == (bytes - 1) ? 127 : 255));

  if ((source[bytes - 1] & 128) && (value > 0))
    value = - value;

  *dest = value;
  return 0;
}

/* Write a BYTES*8-bit quantity to FILE, portably. Returns a non-zero
   value if the write fails, or if VALUE can't be stored in BYTES*8
   bits.

   Note that VALUE may not actually be large enough to hold BYTES*8
   bits, but BYTES characters will be written anyway.

   BYTES may be a maximum of 10.  */

static int
__write_gcov_type (value, file, bytes)
     gcov_type value;
     FILE *file;
     size_t bytes;
{
  char c[10];

  if (bytes > 10 || __store_gcov_type (value, c, bytes))
    return 1;
  else
    return fwrite(c, 1, bytes, file) != bytes;
}

static int
__write_long (value, file, bytes)
     long value;
     FILE *file;
     size_t bytes;
{
  char c[10];

  if (bytes > 10 || __store_gcov_type ((gcov_type)value, c, bytes))
    return 1;
  else
    return fwrite(c, 1, bytes, file) != bytes;
}

/* Read a quantity containing BYTES bytes from FILE, portably. Return
   a non-zero value if the read fails or if the value will not fit
   in DEST.

   Note that DEST may not be large enough to hold all of the requested
   data, but the function will read BYTES characters anyway.

   BYTES may be a maximum of 10.  */

static int
__read_gcov_type (dest, file, bytes)
     gcov_type *dest;
     FILE *file;
     size_t bytes;
{
  char c[10];

  if (bytes > 10 || fread(c, 1, bytes, file) != bytes)
    return 1;
  else
    return __fetch_gcov_type (dest, c, bytes);
}

static int
__read_long (dest, file, bytes)
     long *dest;
     FILE *file;
     size_t bytes;
{
  char c[10];

  if (bytes > 10 || fread(c, 1, bytes, file) != bytes)
    return 1;
  else
    return __fetch_long (dest, c, bytes);
}

#endif /* ! GCC_GCOV_IO_H */
