support/support_test_compare_blob.c

   1 /* Check two binary blobs for equality.
   2    Copyright (C) 2018-2020 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <string.h>
  22 #include <support/check.h>
  23 #include <support/support.h>
  24 #include <support/xmemstream.h>
  25
  26 static void
  27 report_length (const char *what, unsigned long int length, const char *expr)
  28 {
  29   printf ("  %s %lu bytes (from %s)\n", what, length, expr);
  30 }
  31
  32 static void
  33 report_blob (const char *what, const unsigned char *blob,
  34              unsigned long int length, const char *expr)
  35 {
  36   if (blob == NULL && length > 0)
  37     printf ("  %s (evaluated from %s): NULL\n", what, expr);
  38   else if (length > 0)
  39     {
  40       printf ("  %s (evaluated from %s):\n", what, expr);
  41       char *quoted = support_quote_blob (blob, length);
  42       printf ("      \"%s\"\n", quoted);
  43       free (quoted);
  44
  45       fputs ("     ", stdout);
  46       for (unsigned long i = 0; i < length; ++i)
  47         printf (" %02X", blob[i]);
  48       putc ('\n', stdout);
  49     }
  50 }
  51
  52 void
  53 support_test_compare_blob (const void *left, unsigned long int left_length,
  54                            const void *right, unsigned long int right_length,
  55                            const char *file, int line,
  56                            const char *left_expr, const char *left_len_expr,
  57                            const char *right_expr, const char *right_len_expr)
  58 {
  59   /* No differences are possible if both lengths are null.  */
  60   if (left_length == 0 && right_length == 0)
  61     return;
  62
  63   if (left_length != right_length || left == NULL || right == NULL
  64       || memcmp (left, right, left_length) != 0)
  65     {
  66       support_record_failure ();
  67       printf ("%s:%d: error: blob comparison failed\n", file, line);
  68       if (left_length == right_length)
  69         printf ("  blob length: %lu bytes\n", left_length);
  70       else
  71         {
  72           report_length ("left length: ", left_length, left_len_expr);
  73           report_length ("right length:", right_length, right_len_expr);
  74         }
  75       report_blob ("left", left, left_length, left_expr);
  76       report_blob ("right", right, right_length, right_expr);
  77     }
  78 }