gcc/genchecksum.c

   1 /* Generate checksums of executables for PCH validation
   2    Copyright (C) 2005, 2007
   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 3, 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 COPYING3.  If not see
  19 <http://www.gnu.org/licenses/>.  */
  20
  21 #include "bconfig.h"
  22 #include "system.h"
  23 #include "md5.h"
  24
  25 static void
  26 usage (void)
  27 {
  28   fputs ("Usage: genchecksums <filename>\n", stderr);
  29 }
  30
  31 static void
  32 dosum (const char *file)
  33 {
  34   FILE *f;
  35   unsigned char result[16];
  36   int i;
  37
  38   f = fopen (file, "rb");
  39   if (!f)
  40     {
  41       fprintf (stderr, "opening %s: %s\n", file, xstrerror (errno));
  42       exit (1);
  43     }
  44
  45   /* Some executable formats have timestamps in the first 16 bytes, yuck.  */
  46   if (fseek (f, 16, SEEK_SET) != 0)
  47      {
  48       fprintf (stderr, "seeking in %s: %s\n", file, xstrerror (errno));
  49       exit (1);
  50     }
  51
  52   if (md5_stream (f, result) != 0
  53       || fclose (f) != 0)
  54      {
  55       fprintf (stderr, "reading %s: %s\n", file, xstrerror (errno));
  56       exit (1);
  57     }
  58
  59   fputs ("const unsigned char executable_checksum[16] = { ", stdout);
  60   for (i = 0; i < 16; i++)
  61     printf ("%#02x%s", result[i], i == 15 ? " };\n" : ", ");
  62 }
  63
  64 int
  65 main (int argc, char ** argv)
  66 {
  67   if (argc != 2)
  68     {
  69       usage ();
  70       return 1;
  71     }
  72
  73   dosum (argv[1]);
  74
  75   return 0;
  76 }