gcc/gcov-io.h

   1 /* Machine-independent I/O routines for gcov.
   2    Copyright (C) 1996, 1997, 1998 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 static int __fetch_long         PROTO ((long *, char *, size_t));
  28 static int __store_long         PROTO ((long, char *, size_t));
  29 static int __read_long          PROTO ((long *, FILE *, size_t));
  30 static int __write_long         PROTO ((long, FILE *, size_t));
  31
  32 /* These routines only work for signed values. */
  33
  34 /* Store a portable representation of VALUE in DEST using BYTES*8-1 bits.
  35    Return a non-zero value if VALUE requires more than BYTES*8-1 bits
  36    to store. */
  37
  38 static int
  39 __store_long (value, dest, bytes)
  40      long value;
  41      char *dest;
  42      size_t bytes;
  43 {
  44   int upper_bit = (value < 0 ? 128 : 0);
  45   size_t i;
  46
  47   if (value < 0)
  48     {
  49       long oldvalue = value;
  50       value = -value;
  51       if (oldvalue != -value)
  52         return 1;
  53     }
  54
  55   for(i = 0 ; i < (sizeof (value) < bytes ? sizeof (value) : bytes) ; i++) {
  56     dest[i] = value & (i == (bytes - 1) ? 127 : 255);
  57     value = value / 256;
  58   }
  59
  60   if (value && value != -1)
  61     return 1;
  62
  63   for(; i < bytes ; i++)
  64     dest[i] = 0;
  65   dest[bytes - 1] |= upper_bit;
  66   return 0;
  67 }
  68
  69 /* Retrieve a quantity containing BYTES*8-1 bits from SOURCE and store
  70    the result in DEST. Returns a non-zero value if the value in SOURCE
  71    will not fit in DEST. */
  72
  73 static int
  74 __fetch_long (dest, source, bytes)
  75      long *dest;
  76      char *source;
  77      size_t bytes;
  78 {
  79   long value = 0;
  80   int i;
  81
  82   for (i = bytes - 1; (size_t) i > (sizeof (*dest) - 1); i--)
  83     if (source[i] & ((size_t) i == (bytes - 1) ? 127 : 255 ))
  84       return 1;
  85
  86   for (; i >= 0; i--)
  87     value = value * 256 + (source[i] & ((size_t)i == (bytes - 1) ? 127 : 255));
  88
  89   if ((source[bytes - 1] & 128) && (value > 0))
  90     value = - value;
  91
  92   *dest = value;
  93   return 0;
  94 }
  95
  96 /* Write a BYTES*8-bit quantity to FILE, portably. Returns a non-zero
  97    value if the write fails, or if VALUE can't be stored in BYTES*8
  98    bits.
  99
 100    Note that VALUE may not actually be large enough to hold BYTES*8
 101    bits, but BYTES characters will be written anyway.
 102
 103    BYTES may be a maximum of 10. */
 104
 105 static int
 106 __write_long (value, file, bytes)
 107      long value;
 108      FILE *file;
 109      size_t bytes;
 110 {
 111   char c[10];
 112
 113   if (bytes > 10 || __store_long (value, c, bytes))
 114     return 1;
 115   else
 116     return fwrite(c, 1, bytes, file) != bytes;
 117 }
 118
 119 /* Read a quantity containing BYTES bytes from FILE, portably. Return
 120    a non-zero value if the read fails or if the value will not fit
 121    in DEST.
 122
 123    Note that DEST may not be large enough to hold all of the requested
 124    data, but the function will read BYTES characters anyway.
 125
 126    BYTES may be a maximum of 10. */
 127
 128 static int
 129 __read_long (dest, file, bytes)
 130      long *dest;
 131      FILE *file;
 132      size_t bytes;
 133 {
 134   char c[10];
 135
 136   if (bytes > 10 || fread(c, 1, bytes, file) != bytes)
 137     return 1;
 138   else
 139     return __fetch_long (dest, c, bytes);
 140 }
 141
 142 #endif