gcc/genchecksum.c

   1 /* Generate checksums of executables for PCH validation
   2    Copyright (C) 2005
   3    Free Software Foundation, Inc.
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify it under
   8 the terms of the GNU General Public License as published by the Free
   9 Software Foundation; either version 2, or (at your option) any later
  10 version.
  11
  12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15 for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING.  If not, write to the Free
  19 Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
  20 02110-1301, USA.  */
  21
  22 #include "bconfig.h"
  23 #include "system.h"
  24 #include "md5.h"
  25
  26 static void
  27 usage (void)
  28 {
  29   fputs ("Usage: genchecksums <filename>\n", stderr);
  30 }
  31
  32 static void
  33 dosum (const char *file)
  34 {
  35   FILE *f;
  36   unsigned char result[16];
  37   int i;
  38
  39   f = fopen (file, "rb");
  40   if (!f)
  41     {
  42       fprintf (stderr, "opening %s: %s\n", file, xstrerror (errno));
  43       exit (1);
  44     }
  45
  46   /* Some executable formats have timestamps in the first 16 bytes, yuck.  */
  47   if (fseek (f, 16, SEEK_SET) != 0)
  48      {
  49       fprintf (stderr, "seeking in %s: %s\n", file, xstrerror (errno));
  50       exit (1);
  51     }
  52
  53   if (md5_stream (f, result) != 0
  54       || fclose (f) != 0)
  55      {
  56       fprintf (stderr, "reading %s: %s\n", file, xstrerror (errno));
  57       exit (1);
  58     }
  59
  60   fputs ("const unsigned char executable_checksum[16] = { ", stdout);
  61   for (i = 0; i < 16; i++)
  62     printf ("%#02x%s", result[i], i == 15 ? " };\n" : ", ");
  63 }
  64
  65 int
  66 main (int argc, char ** argv)
  67 {
  68   if (argc != 2)
  69     {
  70       usage ();
  71       return 1;
  72     }
  73
  74   dosum (argv[1]);
  75
  76   return 0;
  77 }