gcc/gcov-io.h

   1 /* Machine-independent I/O routines for gcov.
   2    Copyright (C) 1996, 1997 Free Software Foundation, Inc.
   3    Contributed by Bob Manson <manson@cygnus.com>.
   4
   5 This file is part of GNU CC.
   6
   7 GNU CC is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 2, or (at your option)
  10 any later version.
  11
  12 GNU CC is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GNU CC; see the file COPYING.  If not, write to
  19 the Free Software Foundation, 59 Temple Place - Suite 330,
  20 Boston, MA 02111-1307, USA.  */
  21
  22 #ifndef GCOV_IO_H
  23 #define GCOV_IO_H
  24 #include <stdio.h>
  25 #include <sys/types.h>
  26
  27 /* These routines only work for signed values. */
  28
  29 /* Store a portable representation of VALUE in DEST using BYTES*8-1 bits.
  30    Return a non-zero value if VALUE requires more than BYTES*8-1 bits
  31    to store. */
  32
  33 static int
  34 __store_long (value, dest, bytes)
  35      long value;
  36      char *dest;
  37      size_t bytes;
  38 {
  39   int upper_bit = (value < 0 ? 128 : 0);
  40   size_t i;
  41
  42   if (value < 0)
  43     {
  44       long oldvalue = value;
  45       value = -value;
  46       if (oldvalue != -value)
  47         return 1;
  48     }
  49
  50   for(i = 0 ; i < (sizeof (value) < bytes ? sizeof (value) : bytes) ; i++) {
  51     dest[i] = value & (i == (bytes - 1) ? 127 : 255);
  52     value = value / 256;
  53   }
  54
  55   if (value && value != -1)
  56     return 1;
  57
  58   for(; i < bytes ; i++)
  59     dest[i] = 0;
  60   dest[bytes - 1] |= upper_bit;
  61   return 0;
  62 }
  63
  64 /* Retrieve a quantity containing BYTES*8-1 bits from SOURCE and store
  65    the result in DEST. Returns a non-zero value if the value in SOURCE
  66    will not fit in DEST. */
  67
  68 static int
  69 __fetch_long (dest, source, bytes)
  70      long *dest;
  71      char *source;
  72      int bytes;
  73 {
  74   long value = 0;
  75   int i;
  76
  77   for (i = bytes - 1; i > (sizeof (*dest) - 1); i--)
  78     if (source[i] & (i == (bytes - 1) ? 127 : 255 ))
  79       return 1;
  80
  81   for (; i >= 0; i--)
  82     value = value * 256 + (source[i] & (i == (bytes - 1) ? 127 : 255));
  83
  84   if ((source[bytes - 1] & 128) && (value > 0))
  85     value = - value;
  86
  87   *dest = value;
  88   return 0;
  89 }
  90
  91 /* Write a BYTES*8-bit quantity to FILE, portably. Returns a non-zero
  92    value if the write fails, or if VALUE can't be stored in BYTES*8
  93    bits.
  94
  95    Note that VALUE may not actually be large enough to hold BYTES*8
  96    bits, but BYTES characters will be written anyway.
  97
  98    BYTES may be a maximum of 10. */
  99
 100 static int
 101 __write_long (value, file, bytes)
 102      long value;
 103      FILE *file;
 104      size_t bytes;
 105 {
 106   char c[10];
 107
 108   if (bytes > 10 || __store_long (value, c, bytes))
 109     return 1;
 110   else
 111     return fwrite(c, 1, bytes, file) != bytes;
 112 }
 113
 114 /* Read a quantity containing BYTES bytes from FILE, portably. Return
 115    a non-zero value if the read fails or if the value will not fit
 116    in DEST.
 117
 118    Note that DEST may not be large enough to hold all of the requested
 119    data, but the function will read BYTES characters anyway.
 120
 121    BYTES may be a maximum of 10. */
 122
 123 static int
 124 __read_long (dest, file, bytes)
 125      long *dest;
 126      FILE *file;
 127      size_t bytes;
 128 {
 129   char c[10];
 130
 131   if (bytes > 10 || fread(c, 1, bytes, file) != bytes)
 132     return 1;
 133   else
 134     return __fetch_long (dest, c, bytes);
 135 }
 136
 137 #endif