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
  26 /* These routines only work for signed values. */
  27
  28 /* Store a portable representation of VALUE in DEST using BYTES*8-1 bits.
  29    Return a non-zero value if VALUE requires more than BYTES*8-1 bits
  30    to store. */
  31
  32 static int
  33 __store_long (value, dest, bytes)
  34      long value;
  35      char *dest;
  36      int bytes;
  37 {
  38   int upper_bit = (value < 0 ? 128 : 0);
  39   int i;
  40
  41   if (value < 0)
  42     {
  43       long oldvalue = value;
  44       value = -value;
  45       if (oldvalue != -value)
  46         return 1;
  47     }
  48
  49   for(i = 0 ; i < (sizeof (value) < bytes ? sizeof (value) : bytes) ; i++) {
  50     dest[i] = value & (i == (bytes - 1) ? 127 : 255);
  51     value = value / 256;
  52   }
  53
  54   if (value && value != -1)
  55     return 1;
  56
  57   for(; i < bytes ; i++)
  58     dest[i] = 0;
  59   dest[bytes - 1] |= upper_bit;
  60   return 0;
  61 }
  62
  63 /* Retrieve a quantity containing BYTES*8-1 bits from SOURCE and store
  64    the result in DEST. Returns a non-zero value if the value in SOURCE
  65    will not fit in DEST. */
  66
  67 static int
  68 __fetch_long (dest, source, bytes)
  69      long *dest;
  70      char *source;
  71      int bytes;
  72 {
  73   long value = 0;
  74   int i;
  75
  76   for (i = bytes - 1; i > (sizeof (*dest) - 1); i--)
  77     if (source[i] & (i == (bytes - 1) ? 127 : 255 ))
  78       return 1;
  79
  80   for (; i >= 0; i--)
  81     value = value * 256 + (source[i] & (i == (bytes - 1) ? 127 : 255));
  82
  83   if ((source[bytes - 1] & 128) && (value > 0))
  84     value = - value;
  85
  86   *dest = value;
  87   return 0;
  88 }
  89
  90 /* Write a BYTES*8-bit quantity to FILE, portably. Returns a non-zero
  91    value if the write fails, or if VALUE can't be stored in BYTES*8
  92    bits.
  93
  94    Note that VALUE may not actually be large enough to hold BYTES*8
  95    bits, but BYTES characters will be written anyway.
  96
  97    BYTES may be a maximum of 10. */
  98
  99 static int
 100 __write_long (value, file, bytes)
 101      long value;
 102      FILE *file;
 103      int bytes;
 104 {
 105   char c[10];
 106
 107   if (bytes > 10 || __store_long (value, c, bytes))
 108     return 1;
 109   else
 110     return fwrite(c, 1, bytes, file) != bytes;
 111 }
 112
 113 /* Read a quantity containing BYTES bytes from FILE, portably. Return
 114    a non-zero value if the read fails or if the value will not fit
 115    in DEST.
 116
 117    Note that DEST may not be large enough to hold all of the requested
 118    data, but the function will read BYTES characters anyway.
 119
 120    BYTES may be a maximum of 10. */
 121
 122 static int
 123 __read_long (dest, file, bytes)
 124      long *dest;
 125      FILE *file;
 126      int bytes;
 127 {
 128   char c[10];
 129
 130   if (bytes > 10 || fread(c, 1, bytes, file) != bytes)
 131     return 1;
 132   else
 133     return __fetch_long (dest, c, bytes);
 134 }
 135
 136 #endif